File : sem_ch3.adb
1 ------------------------------------------------------------------------------
2 -- --
3 -- GNAT COMPILER COMPONENTS --
4 -- --
5 -- S E M _ C H 3 --
6 -- --
7 -- B o d y --
8 -- --
9 -- Copyright (C) 1992-2016, Free Software Foundation, Inc. --
10 -- --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
20 -- --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
23 -- --
24 ------------------------------------------------------------------------------
25
26 with Aspects; use Aspects;
27 with Atree; use Atree;
28 with Checks; use Checks;
29 with Contracts; use Contracts;
30 with Debug; use Debug;
31 with Elists; use Elists;
32 with Einfo; use Einfo;
33 with Errout; use Errout;
34 with Eval_Fat; use Eval_Fat;
35 with Exp_Ch3; use Exp_Ch3;
36 with Exp_Ch9; use Exp_Ch9;
37 with Exp_Disp; use Exp_Disp;
38 with Exp_Dist; use Exp_Dist;
39 with Exp_Tss; use Exp_Tss;
40 with Exp_Util; use Exp_Util;
41 with Fname; use Fname;
42 with Freeze; use Freeze;
43 with Ghost; use Ghost;
44 with Itypes; use Itypes;
45 with Layout; use Layout;
46 with Lib; use Lib;
47 with Lib.Xref; use Lib.Xref;
48 with Namet; use Namet;
49 with Nmake; use Nmake;
50 with Opt; use Opt;
51 with Restrict; use Restrict;
52 with Rident; use Rident;
53 with Rtsfind; use Rtsfind;
54 with Sem; use Sem;
55 with Sem_Aux; use Sem_Aux;
56 with Sem_Case; use Sem_Case;
57 with Sem_Cat; use Sem_Cat;
58 with Sem_Ch6; use Sem_Ch6;
59 with Sem_Ch7; use Sem_Ch7;
60 with Sem_Ch8; use Sem_Ch8;
61 with Sem_Ch13; use Sem_Ch13;
62 with Sem_Dim; use Sem_Dim;
63 with Sem_Disp; use Sem_Disp;
64 with Sem_Dist; use Sem_Dist;
65 with Sem_Elim; use Sem_Elim;
66 with Sem_Eval; use Sem_Eval;
67 with Sem_Mech; use Sem_Mech;
68 with Sem_Res; use Sem_Res;
69 with Sem_Smem; use Sem_Smem;
70 with Sem_Type; use Sem_Type;
71 with Sem_Util; use Sem_Util;
72 with Sem_Warn; use Sem_Warn;
73 with Stand; use Stand;
74 with Sinfo; use Sinfo;
75 with Sinput; use Sinput;
76 with Snames; use Snames;
77 with Targparm; use Targparm;
78 with Tbuild; use Tbuild;
79 with Ttypes; use Ttypes;
80 with Uintp; use Uintp;
81 with Urealp; use Urealp;
82
83 package body Sem_Ch3 is
84
85 -----------------------
86 -- Local Subprograms --
87 -----------------------
88
89 procedure Add_Interface_Tag_Components (N : Node_Id; Typ : Entity_Id);
90 -- Ada 2005 (AI-251): Add the tag components corresponding to all the
91 -- abstract interface types implemented by a record type or a derived
92 -- record type.
93
94 procedure Build_Derived_Type
95 (N : Node_Id;
96 Parent_Type : Entity_Id;
97 Derived_Type : Entity_Id;
98 Is_Completion : Boolean;
99 Derive_Subps : Boolean := True);
100 -- Create and decorate a Derived_Type given the Parent_Type entity. N is
101 -- the N_Full_Type_Declaration node containing the derived type definition.
102 -- Parent_Type is the entity for the parent type in the derived type
103 -- definition and Derived_Type the actual derived type. Is_Completion must
104 -- be set to False if Derived_Type is the N_Defining_Identifier node in N
105 -- (i.e. Derived_Type = Defining_Identifier (N)). In this case N is not the
106 -- completion of a private type declaration. If Is_Completion is set to
107 -- True, N is the completion of a private type declaration and Derived_Type
108 -- is different from the defining identifier inside N (i.e. Derived_Type /=
109 -- Defining_Identifier (N)). Derive_Subps indicates whether the parent
110 -- subprograms should be derived. The only case where this parameter is
111 -- False is when Build_Derived_Type is recursively called to process an
112 -- implicit derived full type for a type derived from a private type (in
113 -- that case the subprograms must only be derived for the private view of
114 -- the type).
115 --
116 -- ??? These flags need a bit of re-examination and re-documentation:
117 -- ??? are they both necessary (both seem related to the recursion)?
118
119 procedure Build_Derived_Access_Type
120 (N : Node_Id;
121 Parent_Type : Entity_Id;
122 Derived_Type : Entity_Id);
123 -- Subsidiary procedure to Build_Derived_Type. For a derived access type,
124 -- create an implicit base if the parent type is constrained or if the
125 -- subtype indication has a constraint.
126
127 procedure Build_Derived_Array_Type
128 (N : Node_Id;
129 Parent_Type : Entity_Id;
130 Derived_Type : Entity_Id);
131 -- Subsidiary procedure to Build_Derived_Type. For a derived array type,
132 -- create an implicit base if the parent type is constrained or if the
133 -- subtype indication has a constraint.
134
135 procedure Build_Derived_Concurrent_Type
136 (N : Node_Id;
137 Parent_Type : Entity_Id;
138 Derived_Type : Entity_Id);
139 -- Subsidiary procedure to Build_Derived_Type. For a derived task or
140 -- protected type, inherit entries and protected subprograms, check
141 -- legality of discriminant constraints if any.
142
143 procedure Build_Derived_Enumeration_Type
144 (N : Node_Id;
145 Parent_Type : Entity_Id;
146 Derived_Type : Entity_Id);
147 -- Subsidiary procedure to Build_Derived_Type. For a derived enumeration
148 -- type, we must create a new list of literals. Types derived from
149 -- Character and [Wide_]Wide_Character are special-cased.
150
151 procedure Build_Derived_Numeric_Type
152 (N : Node_Id;
153 Parent_Type : Entity_Id;
154 Derived_Type : Entity_Id);
155 -- Subsidiary procedure to Build_Derived_Type. For numeric types, create
156 -- an anonymous base type, and propagate constraint to subtype if needed.
157
158 procedure Build_Derived_Private_Type
159 (N : Node_Id;
160 Parent_Type : Entity_Id;
161 Derived_Type : Entity_Id;
162 Is_Completion : Boolean;
163 Derive_Subps : Boolean := True);
164 -- Subsidiary procedure to Build_Derived_Type. This procedure is complex
165 -- because the parent may or may not have a completion, and the derivation
166 -- may itself be a completion.
167
168 procedure Build_Derived_Record_Type
169 (N : Node_Id;
170 Parent_Type : Entity_Id;
171 Derived_Type : Entity_Id;
172 Derive_Subps : Boolean := True);
173 -- Subsidiary procedure used for tagged and untagged record types
174 -- by Build_Derived_Type and Analyze_Private_Extension_Declaration.
175 -- All parameters are as in Build_Derived_Type except that N, in
176 -- addition to being an N_Full_Type_Declaration node, can also be an
177 -- N_Private_Extension_Declaration node. See the definition of this routine
178 -- for much more info. Derive_Subps indicates whether subprograms should be
179 -- derived from the parent type. The only case where Derive_Subps is False
180 -- is for an implicit derived full type for a type derived from a private
181 -- type (see Build_Derived_Type).
182
183 procedure Build_Discriminal (Discrim : Entity_Id);
184 -- Create the discriminal corresponding to discriminant Discrim, that is
185 -- the parameter corresponding to Discrim to be used in initialization
186 -- procedures for the type where Discrim is a discriminant. Discriminals
187 -- are not used during semantic analysis, and are not fully defined
188 -- entities until expansion. Thus they are not given a scope until
189 -- initialization procedures are built.
190
191 function Build_Discriminant_Constraints
192 (T : Entity_Id;
193 Def : Node_Id;
194 Derived_Def : Boolean := False) return Elist_Id;
195 -- Validate discriminant constraints and return the list of the constraints
196 -- in order of discriminant declarations, where T is the discriminated
197 -- unconstrained type. Def is the N_Subtype_Indication node where the
198 -- discriminants constraints for T are specified. Derived_Def is True
199 -- when building the discriminant constraints in a derived type definition
200 -- of the form "type D (...) is new T (xxx)". In this case T is the parent
201 -- type and Def is the constraint "(xxx)" on T and this routine sets the
202 -- Corresponding_Discriminant field of the discriminants in the derived
203 -- type D to point to the corresponding discriminants in the parent type T.
204
205 procedure Build_Discriminated_Subtype
206 (T : Entity_Id;
207 Def_Id : Entity_Id;
208 Elist : Elist_Id;
209 Related_Nod : Node_Id;
210 For_Access : Boolean := False);
211 -- Subsidiary procedure to Constrain_Discriminated_Type and to
212 -- Process_Incomplete_Dependents. Given
213 --
214 -- T (a possibly discriminated base type)
215 -- Def_Id (a very partially built subtype for T),
216 --
217 -- the call completes Def_Id to be the appropriate E_*_Subtype.
218 --
219 -- The Elist is the list of discriminant constraints if any (it is set
220 -- to No_Elist if T is not a discriminated type, and to an empty list if
221 -- T has discriminants but there are no discriminant constraints). The
222 -- Related_Nod is the same as Decl_Node in Create_Constrained_Components.
223 -- The For_Access says whether or not this subtype is really constraining
224 -- an access type. That is its sole purpose is the designated type of an
225 -- access type -- in which case a Private_Subtype Is_For_Access_Subtype
226 -- is built to avoid freezing T when the access subtype is frozen.
227
228 function Build_Scalar_Bound
229 (Bound : Node_Id;
230 Par_T : Entity_Id;
231 Der_T : Entity_Id) return Node_Id;
232 -- The bounds of a derived scalar type are conversions of the bounds of
233 -- the parent type. Optimize the representation if the bounds are literals.
234 -- Needs a more complete spec--what are the parameters exactly, and what
235 -- exactly is the returned value, and how is Bound affected???
236
237 procedure Build_Underlying_Full_View
238 (N : Node_Id;
239 Typ : Entity_Id;
240 Par : Entity_Id);
241 -- If the completion of a private type is itself derived from a private
242 -- type, or if the full view of a private subtype is itself private, the
243 -- back-end has no way to compute the actual size of this type. We build
244 -- an internal subtype declaration of the proper parent type to convey
245 -- this information. This extra mechanism is needed because a full
246 -- view cannot itself have a full view (it would get clobbered during
247 -- view exchanges).
248
249 procedure Check_Access_Discriminant_Requires_Limited
250 (D : Node_Id;
251 Loc : Node_Id);
252 -- Check the restriction that the type to which an access discriminant
253 -- belongs must be a concurrent type or a descendant of a type with
254 -- the reserved word 'limited' in its declaration.
255
256 procedure Check_Anonymous_Access_Components
257 (Typ_Decl : Node_Id;
258 Typ : Entity_Id;
259 Prev : Entity_Id;
260 Comp_List : Node_Id);
261 -- Ada 2005 AI-382: an access component in a record definition can refer to
262 -- the enclosing record, in which case it denotes the type itself, and not
263 -- the current instance of the type. We create an anonymous access type for
264 -- the component, and flag it as an access to a component, so accessibility
265 -- checks are properly performed on it. The declaration of the access type
266 -- is placed ahead of that of the record to prevent order-of-elaboration
267 -- circularity issues in Gigi. We create an incomplete type for the record
268 -- declaration, which is the designated type of the anonymous access.
269
270 procedure Check_Delta_Expression (E : Node_Id);
271 -- Check that the expression represented by E is suitable for use as a
272 -- delta expression, i.e. it is of real type and is static.
273
274 procedure Check_Digits_Expression (E : Node_Id);
275 -- Check that the expression represented by E is suitable for use as a
276 -- digits expression, i.e. it is of integer type, positive and static.
277
278 procedure Check_Initialization (T : Entity_Id; Exp : Node_Id);
279 -- Validate the initialization of an object declaration. T is the required
280 -- type, and Exp is the initialization expression.
281
282 procedure Check_Interfaces (N : Node_Id; Def : Node_Id);
283 -- Check ARM rules 3.9.4 (15/2), 9.1 (9.d/2) and 9.4 (11.d/2)
284
285 procedure Check_Or_Process_Discriminants
286 (N : Node_Id;
287 T : Entity_Id;
288 Prev : Entity_Id := Empty);
289 -- If N is the full declaration of the completion T of an incomplete or
290 -- private type, check its discriminants (which are already known to be
291 -- conformant with those of the partial view, see Find_Type_Name),
292 -- otherwise process them. Prev is the entity of the partial declaration,
293 -- if any.
294
295 procedure Check_Real_Bound (Bound : Node_Id);
296 -- Check given bound for being of real type and static. If not, post an
297 -- appropriate message, and rewrite the bound with the real literal zero.
298
299 procedure Constant_Redeclaration
300 (Id : Entity_Id;
301 N : Node_Id;
302 T : out Entity_Id);
303 -- Various checks on legality of full declaration of deferred constant.
304 -- Id is the entity for the redeclaration, N is the N_Object_Declaration,
305 -- node. The caller has not yet set any attributes of this entity.
306
307 function Contain_Interface
308 (Iface : Entity_Id;
309 Ifaces : Elist_Id) return Boolean;
310 -- Ada 2005: Determine whether Iface is present in the list Ifaces
311
312 procedure Convert_Scalar_Bounds
313 (N : Node_Id;
314 Parent_Type : Entity_Id;
315 Derived_Type : Entity_Id;
316 Loc : Source_Ptr);
317 -- For derived scalar types, convert the bounds in the type definition to
318 -- the derived type, and complete their analysis. Given a constraint of the
319 -- form ".. new T range Lo .. Hi", Lo and Hi are analyzed and resolved with
320 -- T'Base, the parent_type. The bounds of the derived type (the anonymous
321 -- base) are copies of Lo and Hi. Finally, the bounds of the derived
322 -- subtype are conversions of those bounds to the derived_type, so that
323 -- their typing is consistent.
324
325 procedure Copy_Array_Base_Type_Attributes (T1, T2 : Entity_Id);
326 -- Copies attributes from array base type T2 to array base type T1. Copies
327 -- only attributes that apply to base types, but not subtypes.
328
329 procedure Copy_Array_Subtype_Attributes (T1, T2 : Entity_Id);
330 -- Copies attributes from array subtype T2 to array subtype T1. Copies
331 -- attributes that apply to both subtypes and base types.
332
333 procedure Create_Constrained_Components
334 (Subt : Entity_Id;
335 Decl_Node : Node_Id;
336 Typ : Entity_Id;
337 Constraints : Elist_Id);
338 -- Build the list of entities for a constrained discriminated record
339 -- subtype. If a component depends on a discriminant, replace its subtype
340 -- using the discriminant values in the discriminant constraint. Subt
341 -- is the defining identifier for the subtype whose list of constrained
342 -- entities we will create. Decl_Node is the type declaration node where
343 -- we will attach all the itypes created. Typ is the base discriminated
344 -- type for the subtype Subt. Constraints is the list of discriminant
345 -- constraints for Typ.
346
347 function Constrain_Component_Type
348 (Comp : Entity_Id;
349 Constrained_Typ : Entity_Id;
350 Related_Node : Node_Id;
351 Typ : Entity_Id;
352 Constraints : Elist_Id) return Entity_Id;
353 -- Given a discriminated base type Typ, a list of discriminant constraints,
354 -- Constraints, for Typ and a component Comp of Typ, create and return the
355 -- type corresponding to Etype (Comp) where all discriminant references
356 -- are replaced with the corresponding constraint. If Etype (Comp) contains
357 -- no discriminant references then it is returned as-is. Constrained_Typ
358 -- is the final constrained subtype to which the constrained component
359 -- belongs. Related_Node is the node where we attach all created itypes.
360
361 procedure Constrain_Access
362 (Def_Id : in out Entity_Id;
363 S : Node_Id;
364 Related_Nod : Node_Id);
365 -- Apply a list of constraints to an access type. If Def_Id is empty, it is
366 -- an anonymous type created for a subtype indication. In that case it is
367 -- created in the procedure and attached to Related_Nod.
368
369 procedure Constrain_Array
370 (Def_Id : in out Entity_Id;
371 SI : Node_Id;
372 Related_Nod : Node_Id;
373 Related_Id : Entity_Id;
374 Suffix : Character);
375 -- Apply a list of index constraints to an unconstrained array type. The
376 -- first parameter is the entity for the resulting subtype. A value of
377 -- Empty for Def_Id indicates that an implicit type must be created, but
378 -- creation is delayed (and must be done by this procedure) because other
379 -- subsidiary implicit types must be created first (which is why Def_Id
380 -- is an in/out parameter). The second parameter is a subtype indication
381 -- node for the constrained array to be created (e.g. something of the
382 -- form string (1 .. 10)). Related_Nod gives the place where this type
383 -- has to be inserted in the tree. The Related_Id and Suffix parameters
384 -- are used to build the associated Implicit type name.
385
386 procedure Constrain_Concurrent
387 (Def_Id : in out Entity_Id;
388 SI : Node_Id;
389 Related_Nod : Node_Id;
390 Related_Id : Entity_Id;
391 Suffix : Character);
392 -- Apply list of discriminant constraints to an unconstrained concurrent
393 -- type.
394 --
395 -- SI is the N_Subtype_Indication node containing the constraint and
396 -- the unconstrained type to constrain.
397 --
398 -- Def_Id is the entity for the resulting constrained subtype. A value
399 -- of Empty for Def_Id indicates that an implicit type must be created,
400 -- but creation is delayed (and must be done by this procedure) because
401 -- other subsidiary implicit types must be created first (which is why
402 -- Def_Id is an in/out parameter).
403 --
404 -- Related_Nod gives the place where this type has to be inserted
405 -- in the tree.
406 --
407 -- The last two arguments are used to create its external name if needed.
408
409 function Constrain_Corresponding_Record
410 (Prot_Subt : Entity_Id;
411 Corr_Rec : Entity_Id;
412 Related_Nod : Node_Id) return Entity_Id;
413 -- When constraining a protected type or task type with discriminants,
414 -- constrain the corresponding record with the same discriminant values.
415
416 procedure Constrain_Decimal (Def_Id : Node_Id; S : Node_Id);
417 -- Constrain a decimal fixed point type with a digits constraint and/or a
418 -- range constraint, and build E_Decimal_Fixed_Point_Subtype entity.
419
420 procedure Constrain_Discriminated_Type
421 (Def_Id : Entity_Id;
422 S : Node_Id;
423 Related_Nod : Node_Id;
424 For_Access : Boolean := False);
425 -- Process discriminant constraints of composite type. Verify that values
426 -- have been provided for all discriminants, that the original type is
427 -- unconstrained, and that the types of the supplied expressions match
428 -- the discriminant types. The first three parameters are like in routine
429 -- Constrain_Concurrent. See Build_Discriminated_Subtype for an explanation
430 -- of For_Access.
431
432 procedure Constrain_Enumeration (Def_Id : Node_Id; S : Node_Id);
433 -- Constrain an enumeration type with a range constraint. This is identical
434 -- to Constrain_Integer, but for the Ekind of the resulting subtype.
435
436 procedure Constrain_Float (Def_Id : Node_Id; S : Node_Id);
437 -- Constrain a floating point type with either a digits constraint
438 -- and/or a range constraint, building a E_Floating_Point_Subtype.
439
440 procedure Constrain_Index
441 (Index : Node_Id;
442 S : Node_Id;
443 Related_Nod : Node_Id;
444 Related_Id : Entity_Id;
445 Suffix : Character;
446 Suffix_Index : Nat);
447 -- Process an index constraint S in a constrained array declaration. The
448 -- constraint can be a subtype name, or a range with or without an explicit
449 -- subtype mark. The index is the corresponding index of the unconstrained
450 -- array. The Related_Id and Suffix parameters are used to build the
451 -- associated Implicit type name.
452
453 procedure Constrain_Integer (Def_Id : Node_Id; S : Node_Id);
454 -- Build subtype of a signed or modular integer type
455
456 procedure Constrain_Ordinary_Fixed (Def_Id : Node_Id; S : Node_Id);
457 -- Constrain an ordinary fixed point type with a range constraint, and
458 -- build an E_Ordinary_Fixed_Point_Subtype entity.
459
460 procedure Copy_And_Swap (Priv, Full : Entity_Id);
461 -- Copy the Priv entity into the entity of its full declaration then swap
462 -- the two entities in such a manner that the former private type is now
463 -- seen as a full type.
464
465 procedure Decimal_Fixed_Point_Type_Declaration
466 (T : Entity_Id;
467 Def : Node_Id);
468 -- Create a new decimal fixed point type, and apply the constraint to
469 -- obtain a subtype of this new type.
470
471 procedure Complete_Private_Subtype
472 (Priv : Entity_Id;
473 Full : Entity_Id;
474 Full_Base : Entity_Id;
475 Related_Nod : Node_Id);
476 -- Complete the implicit full view of a private subtype by setting the
477 -- appropriate semantic fields. If the full view of the parent is a record
478 -- type, build constrained components of subtype.
479
480 procedure Derive_Progenitor_Subprograms
481 (Parent_Type : Entity_Id;
482 Tagged_Type : Entity_Id);
483 -- Ada 2005 (AI-251): To complete type derivation, collect the primitive
484 -- operations of progenitors of Tagged_Type, and replace the subsidiary
485 -- subtypes with Tagged_Type, to build the specs of the inherited interface
486 -- primitives. The derived primitives are aliased to those of the
487 -- interface. This routine takes care also of transferring to the full view
488 -- subprograms associated with the partial view of Tagged_Type that cover
489 -- interface primitives.
490
491 procedure Derived_Standard_Character
492 (N : Node_Id;
493 Parent_Type : Entity_Id;
494 Derived_Type : Entity_Id);
495 -- Subsidiary procedure to Build_Derived_Enumeration_Type which handles
496 -- derivations from types Standard.Character and Standard.Wide_Character.
497
498 procedure Derived_Type_Declaration
499 (T : Entity_Id;
500 N : Node_Id;
501 Is_Completion : Boolean);
502 -- Process a derived type declaration. Build_Derived_Type is invoked
503 -- to process the actual derived type definition. Parameters N and
504 -- Is_Completion have the same meaning as in Build_Derived_Type.
505 -- T is the N_Defining_Identifier for the entity defined in the
506 -- N_Full_Type_Declaration node N, that is T is the derived type.
507
508 procedure Enumeration_Type_Declaration (T : Entity_Id; Def : Node_Id);
509 -- Insert each literal in symbol table, as an overloadable identifier. Each
510 -- enumeration type is mapped into a sequence of integers, and each literal
511 -- is defined as a constant with integer value. If any of the literals are
512 -- character literals, the type is a character type, which means that
513 -- strings are legal aggregates for arrays of components of the type.
514
515 function Expand_To_Stored_Constraint
516 (Typ : Entity_Id;
517 Constraint : Elist_Id) return Elist_Id;
518 -- Given a constraint (i.e. a list of expressions) on the discriminants of
519 -- Typ, expand it into a constraint on the stored discriminants and return
520 -- the new list of expressions constraining the stored discriminants.
521
522 function Find_Type_Of_Object
523 (Obj_Def : Node_Id;
524 Related_Nod : Node_Id) return Entity_Id;
525 -- Get type entity for object referenced by Obj_Def, attaching the implicit
526 -- types generated to Related_Nod.
527
528 procedure Floating_Point_Type_Declaration (T : Entity_Id; Def : Node_Id);
529 -- Create a new float and apply the constraint to obtain subtype of it
530
531 function Has_Range_Constraint (N : Node_Id) return Boolean;
532 -- Given an N_Subtype_Indication node N, return True if a range constraint
533 -- is present, either directly, or as part of a digits or delta constraint.
534 -- In addition, a digits constraint in the decimal case returns True, since
535 -- it establishes a default range if no explicit range is present.
536
537 function Inherit_Components
538 (N : Node_Id;
539 Parent_Base : Entity_Id;
540 Derived_Base : Entity_Id;
541 Is_Tagged : Boolean;
542 Inherit_Discr : Boolean;
543 Discs : Elist_Id) return Elist_Id;
544 -- Called from Build_Derived_Record_Type to inherit the components of
545 -- Parent_Base (a base type) into the Derived_Base (the derived base type).
546 -- For more information on derived types and component inheritance please
547 -- consult the comment above the body of Build_Derived_Record_Type.
548 --
549 -- N is the original derived type declaration
550 --
551 -- Is_Tagged is set if we are dealing with tagged types
552 --
553 -- If Inherit_Discr is set, Derived_Base inherits its discriminants from
554 -- Parent_Base, otherwise no discriminants are inherited.
555 --
556 -- Discs gives the list of constraints that apply to Parent_Base in the
557 -- derived type declaration. If Discs is set to No_Elist, then we have
558 -- the following situation:
559 --
560 -- type Parent (D1..Dn : ..) is [tagged] record ...;
561 -- type Derived is new Parent [with ...];
562 --
563 -- which gets treated as
564 --
565 -- type Derived (D1..Dn : ..) is new Parent (D1,..,Dn) [with ...];
566 --
567 -- For untagged types the returned value is an association list. The list
568 -- starts from the association (Parent_Base => Derived_Base), and then it
569 -- contains a sequence of the associations of the form
570 --
571 -- (Old_Component => New_Component),
572 --
573 -- where Old_Component is the Entity_Id of a component in Parent_Base and
574 -- New_Component is the Entity_Id of the corresponding component in
575 -- Derived_Base. For untagged records, this association list is needed when
576 -- copying the record declaration for the derived base. In the tagged case
577 -- the value returned is irrelevant.
578
579 procedure Inherit_Predicate_Flags (Subt, Par : Entity_Id);
580 -- Propagate static and dynamic predicate flags from a parent to the
581 -- subtype in a subtype declaration with and without constraints.
582
583 function Is_EVF_Procedure (Subp : Entity_Id) return Boolean;
584 -- Subsidiary to Check_Abstract_Overriding and Derive_Subprogram.
585 -- Determine whether subprogram Subp is a procedure subject to pragma
586 -- Extensions_Visible with value False and has at least one controlling
587 -- parameter of mode OUT.
588
589 function Is_Valid_Constraint_Kind
590 (T_Kind : Type_Kind;
591 Constraint_Kind : Node_Kind) return Boolean;
592 -- Returns True if it is legal to apply the given kind of constraint to the
593 -- given kind of type (index constraint to an array type, for example).
594
595 procedure Modular_Type_Declaration (T : Entity_Id; Def : Node_Id);
596 -- Create new modular type. Verify that modulus is in bounds
597
598 procedure New_Concatenation_Op (Typ : Entity_Id);
599 -- Create an abbreviated declaration for an operator in order to
600 -- materialize concatenation on array types.
601
602 procedure Ordinary_Fixed_Point_Type_Declaration
603 (T : Entity_Id;
604 Def : Node_Id);
605 -- Create a new ordinary fixed point type, and apply the constraint to
606 -- obtain subtype of it.
607
608 procedure Prepare_Private_Subtype_Completion
609 (Id : Entity_Id;
610 Related_Nod : Node_Id);
611 -- Id is a subtype of some private type. Creates the full declaration
612 -- associated with Id whenever possible, i.e. when the full declaration
613 -- of the base type is already known. Records each subtype into
614 -- Private_Dependents of the base type.
615
616 procedure Process_Incomplete_Dependents
617 (N : Node_Id;
618 Full_T : Entity_Id;
619 Inc_T : Entity_Id);
620 -- Process all entities that depend on an incomplete type. There include
621 -- subtypes, subprogram types that mention the incomplete type in their
622 -- profiles, and subprogram with access parameters that designate the
623 -- incomplete type.
624
625 -- Inc_T is the defining identifier of an incomplete type declaration, its
626 -- Ekind is E_Incomplete_Type.
627 --
628 -- N is the corresponding N_Full_Type_Declaration for Inc_T.
629 --
630 -- Full_T is N's defining identifier.
631 --
632 -- Subtypes of incomplete types with discriminants are completed when the
633 -- parent type is. This is simpler than private subtypes, because they can
634 -- only appear in the same scope, and there is no need to exchange views.
635 -- Similarly, access_to_subprogram types may have a parameter or a return
636 -- type that is an incomplete type, and that must be replaced with the
637 -- full type.
638 --
639 -- If the full type is tagged, subprogram with access parameters that
640 -- designated the incomplete may be primitive operations of the full type,
641 -- and have to be processed accordingly.
642
643 procedure Process_Real_Range_Specification (Def : Node_Id);
644 -- Given the type definition for a real type, this procedure processes and
645 -- checks the real range specification of this type definition if one is
646 -- present. If errors are found, error messages are posted, and the
647 -- Real_Range_Specification of Def is reset to Empty.
648
649 procedure Propagate_Default_Init_Cond_Attributes
650 (From_Typ : Entity_Id;
651 To_Typ : Entity_Id;
652 Parent_To_Derivation : Boolean := False;
653 Private_To_Full_View : Boolean := False);
654 -- Subsidiary to routines Build_Derived_Type and Process_Full_View. Inherit
655 -- all attributes related to pragma Default_Initial_Condition from From_Typ
656 -- to To_Typ. Flag Parent_To_Derivation should be set when the context is
657 -- the creation of a derived type. Flag Private_To_Full_View should be set
658 -- when processing both views of a private type.
659
660 procedure Record_Type_Declaration
661 (T : Entity_Id;
662 N : Node_Id;
663 Prev : Entity_Id);
664 -- Process a record type declaration (for both untagged and tagged
665 -- records). Parameters T and N are exactly like in procedure
666 -- Derived_Type_Declaration, except that no flag Is_Completion is needed
667 -- for this routine. If this is the completion of an incomplete type
668 -- declaration, Prev is the entity of the incomplete declaration, used for
669 -- cross-referencing. Otherwise Prev = T.
670
671 procedure Record_Type_Definition (Def : Node_Id; Prev_T : Entity_Id);
672 -- This routine is used to process the actual record type definition (both
673 -- for untagged and tagged records). Def is a record type definition node.
674 -- This procedure analyzes the components in this record type definition.
675 -- Prev_T is the entity for the enclosing record type. It is provided so
676 -- that its Has_Task flag can be set if any of the component have Has_Task
677 -- set. If the declaration is the completion of an incomplete type
678 -- declaration, Prev_T is the original incomplete type, whose full view is
679 -- the record type.
680
681 procedure Replace_Components (Typ : Entity_Id; Decl : Node_Id);
682 -- Subsidiary to Build_Derived_Record_Type. For untagged records, we
683 -- build a copy of the declaration tree of the parent, and we create
684 -- independently the list of components for the derived type. Semantic
685 -- information uses the component entities, but record representation
686 -- clauses are validated on the declaration tree. This procedure replaces
687 -- discriminants and components in the declaration with those that have
688 -- been created by Inherit_Components.
689
690 procedure Set_Fixed_Range
691 (E : Entity_Id;
692 Loc : Source_Ptr;
693 Lo : Ureal;
694 Hi : Ureal);
695 -- Build a range node with the given bounds and set it as the Scalar_Range
696 -- of the given fixed-point type entity. Loc is the source location used
697 -- for the constructed range. See body for further details.
698
699 procedure Set_Scalar_Range_For_Subtype
700 (Def_Id : Entity_Id;
701 R : Node_Id;
702 Subt : Entity_Id);
703 -- This routine is used to set the scalar range field for a subtype given
704 -- Def_Id, the entity for the subtype, and R, the range expression for the
705 -- scalar range. Subt provides the parent subtype to be used to analyze,
706 -- resolve, and check the given range.
707
708 procedure Set_Default_SSO (T : Entity_Id);
709 -- T is the entity for an array or record being declared. This procedure
710 -- sets the flags SSO_Set_Low_By_Default/SSO_Set_High_By_Default according
711 -- to the setting of Opt.Default_SSO.
712
713 procedure Signed_Integer_Type_Declaration (T : Entity_Id; Def : Node_Id);
714 -- Create a new signed integer entity, and apply the constraint to obtain
715 -- the required first named subtype of this type.
716
717 procedure Set_Stored_Constraint_From_Discriminant_Constraint
718 (E : Entity_Id);
719 -- E is some record type. This routine computes E's Stored_Constraint
720 -- from its Discriminant_Constraint.
721
722 procedure Diagnose_Interface (N : Node_Id; E : Entity_Id);
723 -- Check that an entity in a list of progenitors is an interface,
724 -- emit error otherwise.
725
726 -----------------------
727 -- Access_Definition --
728 -----------------------
729
730 function Access_Definition
731 (Related_Nod : Node_Id;
732 N : Node_Id) return Entity_Id
733 is
734 Anon_Type : Entity_Id;
735 Anon_Scope : Entity_Id;
736 Desig_Type : Entity_Id;
737 Enclosing_Prot_Type : Entity_Id := Empty;
738
739 begin
740 Check_SPARK_05_Restriction ("access type is not allowed", N);
741
742 if Is_Entry (Current_Scope)
743 and then Is_Task_Type (Etype (Scope (Current_Scope)))
744 then
745 Error_Msg_N ("task entries cannot have access parameters", N);
746 return Empty;
747 end if;
748
749 -- Ada 2005: For an object declaration the corresponding anonymous
750 -- type is declared in the current scope.
751
752 -- If the access definition is the return type of another access to
753 -- function, scope is the current one, because it is the one of the
754 -- current type declaration, except for the pathological case below.
755
756 if Nkind_In (Related_Nod, N_Object_Declaration,
757 N_Access_Function_Definition)
758 then
759 Anon_Scope := Current_Scope;
760
761 -- A pathological case: function returning access functions that
762 -- return access functions, etc. Each anonymous access type created
763 -- is in the enclosing scope of the outermost function.
764
765 declare
766 Par : Node_Id;
767
768 begin
769 Par := Related_Nod;
770 while Nkind_In (Par, N_Access_Function_Definition,
771 N_Access_Definition)
772 loop
773 Par := Parent (Par);
774 end loop;
775
776 if Nkind (Par) = N_Function_Specification then
777 Anon_Scope := Scope (Defining_Entity (Par));
778 end if;
779 end;
780
781 -- For the anonymous function result case, retrieve the scope of the
782 -- function specification's associated entity rather than using the
783 -- current scope. The current scope will be the function itself if the
784 -- formal part is currently being analyzed, but will be the parent scope
785 -- in the case of a parameterless function, and we always want to use
786 -- the function's parent scope. Finally, if the function is a child
787 -- unit, we must traverse the tree to retrieve the proper entity.
788
789 elsif Nkind (Related_Nod) = N_Function_Specification
790 and then Nkind (Parent (N)) /= N_Parameter_Specification
791 then
792 -- If the current scope is a protected type, the anonymous access
793 -- is associated with one of the protected operations, and must
794 -- be available in the scope that encloses the protected declaration.
795 -- Otherwise the type is in the scope enclosing the subprogram.
796
797 -- If the function has formals, The return type of a subprogram
798 -- declaration is analyzed in the scope of the subprogram (see
799 -- Process_Formals) and thus the protected type, if present, is
800 -- the scope of the current function scope.
801
802 if Ekind (Current_Scope) = E_Protected_Type then
803 Enclosing_Prot_Type := Current_Scope;
804
805 elsif Ekind (Current_Scope) = E_Function
806 and then Ekind (Scope (Current_Scope)) = E_Protected_Type
807 then
808 Enclosing_Prot_Type := Scope (Current_Scope);
809 end if;
810
811 if Present (Enclosing_Prot_Type) then
812 Anon_Scope := Scope (Enclosing_Prot_Type);
813
814 else
815 Anon_Scope := Scope (Defining_Entity (Related_Nod));
816 end if;
817
818 -- For an access type definition, if the current scope is a child
819 -- unit it is the scope of the type.
820
821 elsif Is_Compilation_Unit (Current_Scope) then
822 Anon_Scope := Current_Scope;
823
824 -- For access formals, access components, and access discriminants, the
825 -- scope is that of the enclosing declaration,
826
827 else
828 Anon_Scope := Scope (Current_Scope);
829 end if;
830
831 Anon_Type :=
832 Create_Itype
833 (E_Anonymous_Access_Type, Related_Nod, Scope_Id => Anon_Scope);
834
835 if All_Present (N)
836 and then Ada_Version >= Ada_2005
837 then
838 Error_Msg_N ("ALL is not permitted for anonymous access types", N);
839 end if;
840
841 -- Ada 2005 (AI-254): In case of anonymous access to subprograms call
842 -- the corresponding semantic routine
843
844 if Present (Access_To_Subprogram_Definition (N)) then
845
846 -- Compiler runtime units are compiled in Ada 2005 mode when building
847 -- the runtime library but must also be compilable in Ada 95 mode
848 -- (when bootstrapping the compiler).
849
850 Check_Compiler_Unit ("anonymous access to subprogram", N);
851
852 Access_Subprogram_Declaration
853 (T_Name => Anon_Type,
854 T_Def => Access_To_Subprogram_Definition (N));
855
856 if Ekind (Anon_Type) = E_Access_Protected_Subprogram_Type then
857 Set_Ekind
858 (Anon_Type, E_Anonymous_Access_Protected_Subprogram_Type);
859 else
860 Set_Ekind (Anon_Type, E_Anonymous_Access_Subprogram_Type);
861 end if;
862
863 Set_Can_Use_Internal_Rep
864 (Anon_Type, not Always_Compatible_Rep_On_Target);
865
866 -- If the anonymous access is associated with a protected operation,
867 -- create a reference to it after the enclosing protected definition
868 -- because the itype will be used in the subsequent bodies.
869
870 -- If the anonymous access itself is protected, a full type
871 -- declaratiton will be created for it, so that the equivalent
872 -- record type can be constructed. For further details, see
873 -- Replace_Anonymous_Access_To_Protected-Subprogram.
874
875 if Ekind (Current_Scope) = E_Protected_Type
876 and then not Protected_Present (Access_To_Subprogram_Definition (N))
877 then
878 Build_Itype_Reference (Anon_Type, Parent (Current_Scope));
879 end if;
880
881 return Anon_Type;
882 end if;
883
884 Find_Type (Subtype_Mark (N));
885 Desig_Type := Entity (Subtype_Mark (N));
886
887 Set_Directly_Designated_Type (Anon_Type, Desig_Type);
888 Set_Etype (Anon_Type, Anon_Type);
889
890 -- Make sure the anonymous access type has size and alignment fields
891 -- set, as required by gigi. This is necessary in the case of the
892 -- Task_Body_Procedure.
893
894 if not Has_Private_Component (Desig_Type) then
895 Layout_Type (Anon_Type);
896 end if;
897
898 -- Ada 2005 (AI-231): Ada 2005 semantics for anonymous access differs
899 -- from Ada 95 semantics. In Ada 2005, anonymous access must specify if
900 -- the null value is allowed. In Ada 95 the null value is never allowed.
901
902 if Ada_Version >= Ada_2005 then
903 Set_Can_Never_Be_Null (Anon_Type, Null_Exclusion_Present (N));
904 else
905 Set_Can_Never_Be_Null (Anon_Type, True);
906 end if;
907
908 -- The anonymous access type is as public as the discriminated type or
909 -- subprogram that defines it. It is imported (for back-end purposes)
910 -- if the designated type is.
911
912 Set_Is_Public (Anon_Type, Is_Public (Scope (Anon_Type)));
913
914 -- Ada 2005 (AI-231): Propagate the access-constant attribute
915
916 Set_Is_Access_Constant (Anon_Type, Constant_Present (N));
917
918 -- The context is either a subprogram declaration, object declaration,
919 -- or an access discriminant, in a private or a full type declaration.
920 -- In the case of a subprogram, if the designated type is incomplete,
921 -- the operation will be a primitive operation of the full type, to be
922 -- updated subsequently. If the type is imported through a limited_with
923 -- clause, the subprogram is not a primitive operation of the type
924 -- (which is declared elsewhere in some other scope).
925
926 if Ekind (Desig_Type) = E_Incomplete_Type
927 and then not From_Limited_With (Desig_Type)
928 and then Is_Overloadable (Current_Scope)
929 then
930 Append_Elmt (Current_Scope, Private_Dependents (Desig_Type));
931 Set_Has_Delayed_Freeze (Current_Scope);
932 end if;
933
934 -- Ada 2005: If the designated type is an interface that may contain
935 -- tasks, create a Master entity for the declaration. This must be done
936 -- before expansion of the full declaration, because the declaration may
937 -- include an expression that is an allocator, whose expansion needs the
938 -- proper Master for the created tasks.
939
940 if Nkind (Related_Nod) = N_Object_Declaration and then Expander_Active
941 then
942 if Is_Interface (Desig_Type) and then Is_Limited_Record (Desig_Type)
943 then
944 Build_Class_Wide_Master (Anon_Type);
945
946 -- Similarly, if the type is an anonymous access that designates
947 -- tasks, create a master entity for it in the current context.
948
949 elsif Has_Task (Desig_Type) and then Comes_From_Source (Related_Nod)
950 then
951 Build_Master_Entity (Defining_Identifier (Related_Nod));
952 Build_Master_Renaming (Anon_Type);
953 end if;
954 end if;
955
956 -- For a private component of a protected type, it is imperative that
957 -- the back-end elaborate the type immediately after the protected
958 -- declaration, because this type will be used in the declarations
959 -- created for the component within each protected body, so we must
960 -- create an itype reference for it now.
961
962 if Nkind (Parent (Related_Nod)) = N_Protected_Definition then
963 Build_Itype_Reference (Anon_Type, Parent (Parent (Related_Nod)));
964
965 -- Similarly, if the access definition is the return result of a
966 -- function, create an itype reference for it because it will be used
967 -- within the function body. For a regular function that is not a
968 -- compilation unit, insert reference after the declaration. For a
969 -- protected operation, insert it after the enclosing protected type
970 -- declaration. In either case, do not create a reference for a type
971 -- obtained through a limited_with clause, because this would introduce
972 -- semantic dependencies.
973
974 -- Similarly, do not create a reference if the designated type is a
975 -- generic formal, because no use of it will reach the backend.
976
977 elsif Nkind (Related_Nod) = N_Function_Specification
978 and then not From_Limited_With (Desig_Type)
979 and then not Is_Generic_Type (Desig_Type)
980 then
981 if Present (Enclosing_Prot_Type) then
982 Build_Itype_Reference (Anon_Type, Parent (Enclosing_Prot_Type));
983
984 elsif Is_List_Member (Parent (Related_Nod))
985 and then Nkind (Parent (N)) /= N_Parameter_Specification
986 then
987 Build_Itype_Reference (Anon_Type, Parent (Related_Nod));
988 end if;
989
990 -- Finally, create an itype reference for an object declaration of an
991 -- anonymous access type. This is strictly necessary only for deferred
992 -- constants, but in any case will avoid out-of-scope problems in the
993 -- back-end.
994
995 elsif Nkind (Related_Nod) = N_Object_Declaration then
996 Build_Itype_Reference (Anon_Type, Related_Nod);
997 end if;
998
999 return Anon_Type;
1000 end Access_Definition;
1001
1002 -----------------------------------
1003 -- Access_Subprogram_Declaration --
1004 -----------------------------------
1005
1006 procedure Access_Subprogram_Declaration
1007 (T_Name : Entity_Id;
1008 T_Def : Node_Id)
1009 is
1010 procedure Check_For_Premature_Usage (Def : Node_Id);
1011 -- Check that type T_Name is not used, directly or recursively, as a
1012 -- parameter or a return type in Def. Def is either a subtype, an
1013 -- access_definition, or an access_to_subprogram_definition.
1014
1015 -------------------------------
1016 -- Check_For_Premature_Usage --
1017 -------------------------------
1018
1019 procedure Check_For_Premature_Usage (Def : Node_Id) is
1020 Param : Node_Id;
1021
1022 begin
1023 -- Check for a subtype mark
1024
1025 if Nkind (Def) in N_Has_Etype then
1026 if Etype (Def) = T_Name then
1027 Error_Msg_N
1028 ("type& cannot be used before end of its declaration", Def);
1029 end if;
1030
1031 -- If this is not a subtype, then this is an access_definition
1032
1033 elsif Nkind (Def) = N_Access_Definition then
1034 if Present (Access_To_Subprogram_Definition (Def)) then
1035 Check_For_Premature_Usage
1036 (Access_To_Subprogram_Definition (Def));
1037 else
1038 Check_For_Premature_Usage (Subtype_Mark (Def));
1039 end if;
1040
1041 -- The only cases left are N_Access_Function_Definition and
1042 -- N_Access_Procedure_Definition.
1043
1044 else
1045 if Present (Parameter_Specifications (Def)) then
1046 Param := First (Parameter_Specifications (Def));
1047 while Present (Param) loop
1048 Check_For_Premature_Usage (Parameter_Type (Param));
1049 Param := Next (Param);
1050 end loop;
1051 end if;
1052
1053 if Nkind (Def) = N_Access_Function_Definition then
1054 Check_For_Premature_Usage (Result_Definition (Def));
1055 end if;
1056 end if;
1057 end Check_For_Premature_Usage;
1058
1059 -- Local variables
1060
1061 Formals : constant List_Id := Parameter_Specifications (T_Def);
1062 Formal : Entity_Id;
1063 D_Ityp : Node_Id;
1064 Desig_Type : constant Entity_Id :=
1065 Create_Itype (E_Subprogram_Type, Parent (T_Def));
1066
1067 -- Start of processing for Access_Subprogram_Declaration
1068
1069 begin
1070 Check_SPARK_05_Restriction ("access type is not allowed", T_Def);
1071
1072 -- Associate the Itype node with the inner full-type declaration or
1073 -- subprogram spec or entry body. This is required to handle nested
1074 -- anonymous declarations. For example:
1075
1076 -- procedure P
1077 -- (X : access procedure
1078 -- (Y : access procedure
1079 -- (Z : access T)))
1080
1081 D_Ityp := Associated_Node_For_Itype (Desig_Type);
1082 while not (Nkind_In (D_Ityp, N_Full_Type_Declaration,
1083 N_Private_Type_Declaration,
1084 N_Private_Extension_Declaration,
1085 N_Procedure_Specification,
1086 N_Function_Specification,
1087 N_Entry_Body)
1088
1089 or else
1090 Nkind_In (D_Ityp, N_Object_Declaration,
1091 N_Object_Renaming_Declaration,
1092 N_Formal_Object_Declaration,
1093 N_Formal_Type_Declaration,
1094 N_Task_Type_Declaration,
1095 N_Protected_Type_Declaration))
1096 loop
1097 D_Ityp := Parent (D_Ityp);
1098 pragma Assert (D_Ityp /= Empty);
1099 end loop;
1100
1101 Set_Associated_Node_For_Itype (Desig_Type, D_Ityp);
1102
1103 if Nkind_In (D_Ityp, N_Procedure_Specification,
1104 N_Function_Specification)
1105 then
1106 Set_Scope (Desig_Type, Scope (Defining_Entity (D_Ityp)));
1107
1108 elsif Nkind_In (D_Ityp, N_Full_Type_Declaration,
1109 N_Object_Declaration,
1110 N_Object_Renaming_Declaration,
1111 N_Formal_Type_Declaration)
1112 then
1113 Set_Scope (Desig_Type, Scope (Defining_Identifier (D_Ityp)));
1114 end if;
1115
1116 if Nkind (T_Def) = N_Access_Function_Definition then
1117 if Nkind (Result_Definition (T_Def)) = N_Access_Definition then
1118 declare
1119 Acc : constant Node_Id := Result_Definition (T_Def);
1120
1121 begin
1122 if Present (Access_To_Subprogram_Definition (Acc))
1123 and then
1124 Protected_Present (Access_To_Subprogram_Definition (Acc))
1125 then
1126 Set_Etype
1127 (Desig_Type,
1128 Replace_Anonymous_Access_To_Protected_Subprogram
1129 (T_Def));
1130
1131 else
1132 Set_Etype
1133 (Desig_Type,
1134 Access_Definition (T_Def, Result_Definition (T_Def)));
1135 end if;
1136 end;
1137
1138 else
1139 Analyze (Result_Definition (T_Def));
1140
1141 declare
1142 Typ : constant Entity_Id := Entity (Result_Definition (T_Def));
1143
1144 begin
1145 -- If a null exclusion is imposed on the result type, then
1146 -- create a null-excluding itype (an access subtype) and use
1147 -- it as the function's Etype.
1148
1149 if Is_Access_Type (Typ)
1150 and then Null_Exclusion_In_Return_Present (T_Def)
1151 then
1152 Set_Etype (Desig_Type,
1153 Create_Null_Excluding_Itype
1154 (T => Typ,
1155 Related_Nod => T_Def,
1156 Scope_Id => Current_Scope));
1157
1158 else
1159 if From_Limited_With (Typ) then
1160
1161 -- AI05-151: Incomplete types are allowed in all basic
1162 -- declarations, including access to subprograms.
1163
1164 if Ada_Version >= Ada_2012 then
1165 null;
1166
1167 else
1168 Error_Msg_NE
1169 ("illegal use of incomplete type&",
1170 Result_Definition (T_Def), Typ);
1171 end if;
1172
1173 elsif Ekind (Current_Scope) = E_Package
1174 and then In_Private_Part (Current_Scope)
1175 then
1176 if Ekind (Typ) = E_Incomplete_Type then
1177 Append_Elmt (Desig_Type, Private_Dependents (Typ));
1178
1179 elsif Is_Class_Wide_Type (Typ)
1180 and then Ekind (Etype (Typ)) = E_Incomplete_Type
1181 then
1182 Append_Elmt
1183 (Desig_Type, Private_Dependents (Etype (Typ)));
1184 end if;
1185 end if;
1186
1187 Set_Etype (Desig_Type, Typ);
1188 end if;
1189 end;
1190 end if;
1191
1192 if not (Is_Type (Etype (Desig_Type))) then
1193 Error_Msg_N
1194 ("expect type in function specification",
1195 Result_Definition (T_Def));
1196 end if;
1197
1198 else
1199 Set_Etype (Desig_Type, Standard_Void_Type);
1200 end if;
1201
1202 if Present (Formals) then
1203 Push_Scope (Desig_Type);
1204
1205 -- Some special tests here. These special tests can be removed
1206 -- if and when Itypes always have proper parent pointers to their
1207 -- declarations???
1208
1209 -- Special test 1) Link defining_identifier of formals. Required by
1210 -- First_Formal to provide its functionality.
1211
1212 declare
1213 F : Node_Id;
1214
1215 begin
1216 F := First (Formals);
1217
1218 -- In ASIS mode, the access_to_subprogram may be analyzed twice,
1219 -- when it is part of an unconstrained type and subtype expansion
1220 -- is disabled. To avoid back-end problems with shared profiles,
1221 -- use previous subprogram type as the designated type, and then
1222 -- remove scope added above.
1223
1224 if ASIS_Mode and then Present (Scope (Defining_Identifier (F)))
1225 then
1226 Set_Etype (T_Name, T_Name);
1227 Init_Size_Align (T_Name);
1228 Set_Directly_Designated_Type (T_Name,
1229 Scope (Defining_Identifier (F)));
1230 End_Scope;
1231 return;
1232 end if;
1233
1234 while Present (F) loop
1235 if No (Parent (Defining_Identifier (F))) then
1236 Set_Parent (Defining_Identifier (F), F);
1237 end if;
1238
1239 Next (F);
1240 end loop;
1241 end;
1242
1243 Process_Formals (Formals, Parent (T_Def));
1244
1245 -- Special test 2) End_Scope requires that the parent pointer be set
1246 -- to something reasonable, but Itypes don't have parent pointers. So
1247 -- we set it and then unset it ???
1248
1249 Set_Parent (Desig_Type, T_Name);
1250 End_Scope;
1251 Set_Parent (Desig_Type, Empty);
1252 end if;
1253
1254 -- Check for premature usage of the type being defined
1255
1256 Check_For_Premature_Usage (T_Def);
1257
1258 -- The return type and/or any parameter type may be incomplete. Mark the
1259 -- subprogram_type as depending on the incomplete type, so that it can
1260 -- be updated when the full type declaration is seen. This only applies
1261 -- to incomplete types declared in some enclosing scope, not to limited
1262 -- views from other packages.
1263
1264 -- Prior to Ada 2012, access to functions can only have in_parameters.
1265
1266 if Present (Formals) then
1267 Formal := First_Formal (Desig_Type);
1268 while Present (Formal) loop
1269 if Ekind (Formal) /= E_In_Parameter
1270 and then Nkind (T_Def) = N_Access_Function_Definition
1271 and then Ada_Version < Ada_2012
1272 then
1273 Error_Msg_N ("functions can only have IN parameters", Formal);
1274 end if;
1275
1276 if Ekind (Etype (Formal)) = E_Incomplete_Type
1277 and then In_Open_Scopes (Scope (Etype (Formal)))
1278 then
1279 Append_Elmt (Desig_Type, Private_Dependents (Etype (Formal)));
1280 Set_Has_Delayed_Freeze (Desig_Type);
1281 end if;
1282
1283 Next_Formal (Formal);
1284 end loop;
1285 end if;
1286
1287 -- Check whether an indirect call without actuals may be possible. This
1288 -- is used when resolving calls whose result is then indexed.
1289
1290 May_Need_Actuals (Desig_Type);
1291
1292 -- If the return type is incomplete, this is legal as long as the type
1293 -- is declared in the current scope and will be completed in it (rather
1294 -- than being part of limited view).
1295
1296 if Ekind (Etype (Desig_Type)) = E_Incomplete_Type
1297 and then not Has_Delayed_Freeze (Desig_Type)
1298 and then In_Open_Scopes (Scope (Etype (Desig_Type)))
1299 then
1300 Append_Elmt (Desig_Type, Private_Dependents (Etype (Desig_Type)));
1301 Set_Has_Delayed_Freeze (Desig_Type);
1302 end if;
1303
1304 Check_Delayed_Subprogram (Desig_Type);
1305
1306 if Protected_Present (T_Def) then
1307 Set_Ekind (T_Name, E_Access_Protected_Subprogram_Type);
1308 Set_Convention (Desig_Type, Convention_Protected);
1309 else
1310 Set_Ekind (T_Name, E_Access_Subprogram_Type);
1311 end if;
1312
1313 Set_Can_Use_Internal_Rep (T_Name, not Always_Compatible_Rep_On_Target);
1314
1315 Set_Etype (T_Name, T_Name);
1316 Init_Size_Align (T_Name);
1317 Set_Directly_Designated_Type (T_Name, Desig_Type);
1318
1319 Generate_Reference_To_Formals (T_Name);
1320
1321 -- Ada 2005 (AI-231): Propagate the null-excluding attribute
1322
1323 Set_Can_Never_Be_Null (T_Name, Null_Exclusion_Present (T_Def));
1324
1325 Check_Restriction (No_Access_Subprograms, T_Def);
1326 end Access_Subprogram_Declaration;
1327
1328 ----------------------------
1329 -- Access_Type_Declaration --
1330 ----------------------------
1331
1332 procedure Access_Type_Declaration (T : Entity_Id; Def : Node_Id) is
1333 P : constant Node_Id := Parent (Def);
1334 S : constant Node_Id := Subtype_Indication (Def);
1335
1336 Full_Desig : Entity_Id;
1337
1338 begin
1339 Check_SPARK_05_Restriction ("access type is not allowed", Def);
1340
1341 -- Check for permissible use of incomplete type
1342
1343 if Nkind (S) /= N_Subtype_Indication then
1344 Analyze (S);
1345
1346 if Ekind (Root_Type (Entity (S))) = E_Incomplete_Type then
1347 Set_Directly_Designated_Type (T, Entity (S));
1348
1349 -- If the designated type is a limited view, we cannot tell if
1350 -- the full view contains tasks, and there is no way to handle
1351 -- that full view in a client. We create a master entity for the
1352 -- scope, which will be used when a client determines that one
1353 -- is needed.
1354
1355 if From_Limited_With (Entity (S))
1356 and then not Is_Class_Wide_Type (Entity (S))
1357 then
1358 Set_Ekind (T, E_Access_Type);
1359 Build_Master_Entity (T);
1360 Build_Master_Renaming (T);
1361 end if;
1362
1363 else
1364 Set_Directly_Designated_Type (T, Process_Subtype (S, P, T, 'P'));
1365 end if;
1366
1367 -- If the access definition is of the form: ACCESS NOT NULL ..
1368 -- the subtype indication must be of an access type. Create
1369 -- a null-excluding subtype of it.
1370
1371 if Null_Excluding_Subtype (Def) then
1372 if not Is_Access_Type (Entity (S)) then
1373 Error_Msg_N ("null exclusion must apply to access type", Def);
1374
1375 else
1376 declare
1377 Loc : constant Source_Ptr := Sloc (S);
1378 Decl : Node_Id;
1379 Nam : constant Entity_Id := Make_Temporary (Loc, 'S');
1380
1381 begin
1382 Decl :=
1383 Make_Subtype_Declaration (Loc,
1384 Defining_Identifier => Nam,
1385 Subtype_Indication =>
1386 New_Occurrence_Of (Entity (S), Loc));
1387 Set_Null_Exclusion_Present (Decl);
1388 Insert_Before (Parent (Def), Decl);
1389 Analyze (Decl);
1390 Set_Entity (S, Nam);
1391 end;
1392 end if;
1393 end if;
1394
1395 else
1396 Set_Directly_Designated_Type (T,
1397 Process_Subtype (S, P, T, 'P'));
1398 end if;
1399
1400 if All_Present (Def) or Constant_Present (Def) then
1401 Set_Ekind (T, E_General_Access_Type);
1402 else
1403 Set_Ekind (T, E_Access_Type);
1404 end if;
1405
1406 Full_Desig := Designated_Type (T);
1407
1408 if Base_Type (Full_Desig) = T then
1409 Error_Msg_N ("access type cannot designate itself", S);
1410
1411 -- In Ada 2005, the type may have a limited view through some unit in
1412 -- its own context, allowing the following circularity that cannot be
1413 -- detected earlier.
1414
1415 elsif Is_Class_Wide_Type (Full_Desig) and then Etype (Full_Desig) = T
1416 then
1417 Error_Msg_N
1418 ("access type cannot designate its own classwide type", S);
1419
1420 -- Clean up indication of tagged status to prevent cascaded errors
1421
1422 Set_Is_Tagged_Type (T, False);
1423 end if;
1424
1425 Set_Etype (T, T);
1426
1427 -- If the type has appeared already in a with_type clause, it is frozen
1428 -- and the pointer size is already set. Else, initialize.
1429
1430 if not From_Limited_With (T) then
1431 Init_Size_Align (T);
1432 end if;
1433
1434 -- Note that Has_Task is always false, since the access type itself
1435 -- is not a task type. See Einfo for more description on this point.
1436 -- Exactly the same consideration applies to Has_Controlled_Component
1437 -- and to Has_Protected.
1438
1439 Set_Has_Task (T, False);
1440 Set_Has_Protected (T, False);
1441 Set_Has_Timing_Event (T, False);
1442 Set_Has_Controlled_Component (T, False);
1443
1444 -- Initialize field Finalization_Master explicitly to Empty, to avoid
1445 -- problems where an incomplete view of this entity has been previously
1446 -- established by a limited with and an overlaid version of this field
1447 -- (Stored_Constraint) was initialized for the incomplete view.
1448
1449 -- This reset is performed in most cases except where the access type
1450 -- has been created for the purposes of allocating or deallocating a
1451 -- build-in-place object. Such access types have explicitly set pools
1452 -- and finalization masters.
1453
1454 if No (Associated_Storage_Pool (T)) then
1455 Set_Finalization_Master (T, Empty);
1456 end if;
1457
1458 -- Ada 2005 (AI-231): Propagate the null-excluding and access-constant
1459 -- attributes
1460
1461 Set_Can_Never_Be_Null (T, Null_Exclusion_Present (Def));
1462 Set_Is_Access_Constant (T, Constant_Present (Def));
1463 end Access_Type_Declaration;
1464
1465 ----------------------------------
1466 -- Add_Interface_Tag_Components --
1467 ----------------------------------
1468
1469 procedure Add_Interface_Tag_Components (N : Node_Id; Typ : Entity_Id) is
1470 Loc : constant Source_Ptr := Sloc (N);
1471 L : List_Id;
1472 Last_Tag : Node_Id;
1473
1474 procedure Add_Tag (Iface : Entity_Id);
1475 -- Add tag for one of the progenitor interfaces
1476
1477 -------------
1478 -- Add_Tag --
1479 -------------
1480
1481 procedure Add_Tag (Iface : Entity_Id) is
1482 Decl : Node_Id;
1483 Def : Node_Id;
1484 Tag : Entity_Id;
1485 Offset : Entity_Id;
1486
1487 begin
1488 pragma Assert (Is_Tagged_Type (Iface) and then Is_Interface (Iface));
1489
1490 -- This is a reasonable place to propagate predicates
1491
1492 if Has_Predicates (Iface) then
1493 Set_Has_Predicates (Typ);
1494 end if;
1495
1496 Def :=
1497 Make_Component_Definition (Loc,
1498 Aliased_Present => True,
1499 Subtype_Indication =>
1500 New_Occurrence_Of (RTE (RE_Interface_Tag), Loc));
1501
1502 Tag := Make_Temporary (Loc, 'V');
1503
1504 Decl :=
1505 Make_Component_Declaration (Loc,
1506 Defining_Identifier => Tag,
1507 Component_Definition => Def);
1508
1509 Analyze_Component_Declaration (Decl);
1510
1511 Set_Analyzed (Decl);
1512 Set_Ekind (Tag, E_Component);
1513 Set_Is_Tag (Tag);
1514 Set_Is_Aliased (Tag);
1515 Set_Related_Type (Tag, Iface);
1516 Init_Component_Location (Tag);
1517
1518 pragma Assert (Is_Frozen (Iface));
1519
1520 Set_DT_Entry_Count (Tag,
1521 DT_Entry_Count (First_Entity (Iface)));
1522
1523 if No (Last_Tag) then
1524 Prepend (Decl, L);
1525 else
1526 Insert_After (Last_Tag, Decl);
1527 end if;
1528
1529 Last_Tag := Decl;
1530
1531 -- If the ancestor has discriminants we need to give special support
1532 -- to store the offset_to_top value of the secondary dispatch tables.
1533 -- For this purpose we add a supplementary component just after the
1534 -- field that contains the tag associated with each secondary DT.
1535
1536 if Typ /= Etype (Typ) and then Has_Discriminants (Etype (Typ)) then
1537 Def :=
1538 Make_Component_Definition (Loc,
1539 Subtype_Indication =>
1540 New_Occurrence_Of (RTE (RE_Storage_Offset), Loc));
1541
1542 Offset := Make_Temporary (Loc, 'V');
1543
1544 Decl :=
1545 Make_Component_Declaration (Loc,
1546 Defining_Identifier => Offset,
1547 Component_Definition => Def);
1548
1549 Analyze_Component_Declaration (Decl);
1550
1551 Set_Analyzed (Decl);
1552 Set_Ekind (Offset, E_Component);
1553 Set_Is_Aliased (Offset);
1554 Set_Related_Type (Offset, Iface);
1555 Init_Component_Location (Offset);
1556 Insert_After (Last_Tag, Decl);
1557 Last_Tag := Decl;
1558 end if;
1559 end Add_Tag;
1560
1561 -- Local variables
1562
1563 Elmt : Elmt_Id;
1564 Ext : Node_Id;
1565 Comp : Node_Id;
1566
1567 -- Start of processing for Add_Interface_Tag_Components
1568
1569 begin
1570 if not RTE_Available (RE_Interface_Tag) then
1571 Error_Msg
1572 ("(Ada 2005) interface types not supported by this run-time!",
1573 Sloc (N));
1574 return;
1575 end if;
1576
1577 if Ekind (Typ) /= E_Record_Type
1578 or else (Is_Concurrent_Record_Type (Typ)
1579 and then Is_Empty_List (Abstract_Interface_List (Typ)))
1580 or else (not Is_Concurrent_Record_Type (Typ)
1581 and then No (Interfaces (Typ))
1582 and then Is_Empty_Elmt_List (Interfaces (Typ)))
1583 then
1584 return;
1585 end if;
1586
1587 -- Find the current last tag
1588
1589 if Nkind (Type_Definition (N)) = N_Derived_Type_Definition then
1590 Ext := Record_Extension_Part (Type_Definition (N));
1591 else
1592 pragma Assert (Nkind (Type_Definition (N)) = N_Record_Definition);
1593 Ext := Type_Definition (N);
1594 end if;
1595
1596 Last_Tag := Empty;
1597
1598 if not (Present (Component_List (Ext))) then
1599 Set_Null_Present (Ext, False);
1600 L := New_List;
1601 Set_Component_List (Ext,
1602 Make_Component_List (Loc,
1603 Component_Items => L,
1604 Null_Present => False));
1605 else
1606 if Nkind (Type_Definition (N)) = N_Derived_Type_Definition then
1607 L := Component_Items
1608 (Component_List
1609 (Record_Extension_Part
1610 (Type_Definition (N))));
1611 else
1612 L := Component_Items
1613 (Component_List
1614 (Type_Definition (N)));
1615 end if;
1616
1617 -- Find the last tag component
1618
1619 Comp := First (L);
1620 while Present (Comp) loop
1621 if Nkind (Comp) = N_Component_Declaration
1622 and then Is_Tag (Defining_Identifier (Comp))
1623 then
1624 Last_Tag := Comp;
1625 end if;
1626
1627 Next (Comp);
1628 end loop;
1629 end if;
1630
1631 -- At this point L references the list of components and Last_Tag
1632 -- references the current last tag (if any). Now we add the tag
1633 -- corresponding with all the interfaces that are not implemented
1634 -- by the parent.
1635
1636 if Present (Interfaces (Typ)) then
1637 Elmt := First_Elmt (Interfaces (Typ));
1638 while Present (Elmt) loop
1639 Add_Tag (Node (Elmt));
1640 Next_Elmt (Elmt);
1641 end loop;
1642 end if;
1643 end Add_Interface_Tag_Components;
1644
1645 -------------------------------------
1646 -- Add_Internal_Interface_Entities --
1647 -------------------------------------
1648
1649 procedure Add_Internal_Interface_Entities (Tagged_Type : Entity_Id) is
1650 Elmt : Elmt_Id;
1651 Iface : Entity_Id;
1652 Iface_Elmt : Elmt_Id;
1653 Iface_Prim : Entity_Id;
1654 Ifaces_List : Elist_Id;
1655 New_Subp : Entity_Id := Empty;
1656 Prim : Entity_Id;
1657 Restore_Scope : Boolean := False;
1658
1659 begin
1660 pragma Assert (Ada_Version >= Ada_2005
1661 and then Is_Record_Type (Tagged_Type)
1662 and then Is_Tagged_Type (Tagged_Type)
1663 and then Has_Interfaces (Tagged_Type)
1664 and then not Is_Interface (Tagged_Type));
1665
1666 -- Ensure that the internal entities are added to the scope of the type
1667
1668 if Scope (Tagged_Type) /= Current_Scope then
1669 Push_Scope (Scope (Tagged_Type));
1670 Restore_Scope := True;
1671 end if;
1672
1673 Collect_Interfaces (Tagged_Type, Ifaces_List);
1674
1675 Iface_Elmt := First_Elmt (Ifaces_List);
1676 while Present (Iface_Elmt) loop
1677 Iface := Node (Iface_Elmt);
1678
1679 -- Originally we excluded here from this processing interfaces that
1680 -- are parents of Tagged_Type because their primitives are located
1681 -- in the primary dispatch table (and hence no auxiliary internal
1682 -- entities are required to handle secondary dispatch tables in such
1683 -- case). However, these auxiliary entities are also required to
1684 -- handle derivations of interfaces in formals of generics (see
1685 -- Derive_Subprograms).
1686
1687 Elmt := First_Elmt (Primitive_Operations (Iface));
1688 while Present (Elmt) loop
1689 Iface_Prim := Node (Elmt);
1690
1691 if not Is_Predefined_Dispatching_Operation (Iface_Prim) then
1692 Prim :=
1693 Find_Primitive_Covering_Interface
1694 (Tagged_Type => Tagged_Type,
1695 Iface_Prim => Iface_Prim);
1696
1697 if No (Prim) and then Serious_Errors_Detected > 0 then
1698 goto Continue;
1699 end if;
1700
1701 pragma Assert (Present (Prim));
1702
1703 -- Ada 2012 (AI05-0197): If the name of the covering primitive
1704 -- differs from the name of the interface primitive then it is
1705 -- a private primitive inherited from a parent type. In such
1706 -- case, given that Tagged_Type covers the interface, the
1707 -- inherited private primitive becomes visible. For such
1708 -- purpose we add a new entity that renames the inherited
1709 -- private primitive.
1710
1711 if Chars (Prim) /= Chars (Iface_Prim) then
1712 pragma Assert (Has_Suffix (Prim, 'P'));
1713 Derive_Subprogram
1714 (New_Subp => New_Subp,
1715 Parent_Subp => Iface_Prim,
1716 Derived_Type => Tagged_Type,
1717 Parent_Type => Iface);
1718 Set_Alias (New_Subp, Prim);
1719 Set_Is_Abstract_Subprogram
1720 (New_Subp, Is_Abstract_Subprogram (Prim));
1721 end if;
1722
1723 Derive_Subprogram
1724 (New_Subp => New_Subp,
1725 Parent_Subp => Iface_Prim,
1726 Derived_Type => Tagged_Type,
1727 Parent_Type => Iface);
1728
1729 -- Ada 2005 (AI-251): Decorate internal entity Iface_Subp
1730 -- associated with interface types. These entities are
1731 -- only registered in the list of primitives of its
1732 -- corresponding tagged type because they are only used
1733 -- to fill the contents of the secondary dispatch tables.
1734 -- Therefore they are removed from the homonym chains.
1735
1736 Set_Is_Hidden (New_Subp);
1737 Set_Is_Internal (New_Subp);
1738 Set_Alias (New_Subp, Prim);
1739 Set_Is_Abstract_Subprogram
1740 (New_Subp, Is_Abstract_Subprogram (Prim));
1741 Set_Interface_Alias (New_Subp, Iface_Prim);
1742
1743 -- If the returned type is an interface then propagate it to
1744 -- the returned type. Needed by the thunk to generate the code
1745 -- which displaces "this" to reference the corresponding
1746 -- secondary dispatch table in the returned object.
1747
1748 if Is_Interface (Etype (Iface_Prim)) then
1749 Set_Etype (New_Subp, Etype (Iface_Prim));
1750 end if;
1751
1752 -- Internal entities associated with interface types are only
1753 -- registered in the list of primitives of the tagged type.
1754 -- They are only used to fill the contents of the secondary
1755 -- dispatch tables. Therefore they are not needed in the
1756 -- homonym chains.
1757
1758 Remove_Homonym (New_Subp);
1759
1760 -- Hidden entities associated with interfaces must have set
1761 -- the Has_Delay_Freeze attribute to ensure that, in case
1762 -- of locally defined tagged types (or compiling with static
1763 -- dispatch tables generation disabled) the corresponding
1764 -- entry of the secondary dispatch table is filled when such
1765 -- an entity is frozen. This is an expansion activity that must
1766 -- be suppressed for ASIS because it leads to gigi elaboration
1767 -- issues in annotate mode.
1768
1769 if not ASIS_Mode then
1770 Set_Has_Delayed_Freeze (New_Subp);
1771 end if;
1772 end if;
1773
1774 <<Continue>>
1775 Next_Elmt (Elmt);
1776 end loop;
1777
1778 Next_Elmt (Iface_Elmt);
1779 end loop;
1780
1781 if Restore_Scope then
1782 Pop_Scope;
1783 end if;
1784 end Add_Internal_Interface_Entities;
1785
1786 -----------------------------------
1787 -- Analyze_Component_Declaration --
1788 -----------------------------------
1789
1790 procedure Analyze_Component_Declaration (N : Node_Id) is
1791 Loc : constant Source_Ptr := Sloc (Component_Definition (N));
1792 Id : constant Entity_Id := Defining_Identifier (N);
1793 E : constant Node_Id := Expression (N);
1794 Typ : constant Node_Id :=
1795 Subtype_Indication (Component_Definition (N));
1796 T : Entity_Id;
1797 P : Entity_Id;
1798
1799 function Contains_POC (Constr : Node_Id) return Boolean;
1800 -- Determines whether a constraint uses the discriminant of a record
1801 -- type thus becoming a per-object constraint (POC).
1802
1803 function Is_Known_Limited (Typ : Entity_Id) return Boolean;
1804 -- Typ is the type of the current component, check whether this type is
1805 -- a limited type. Used to validate declaration against that of
1806 -- enclosing record.
1807
1808 ------------------
1809 -- Contains_POC --
1810 ------------------
1811
1812 function Contains_POC (Constr : Node_Id) return Boolean is
1813 begin
1814 -- Prevent cascaded errors
1815
1816 if Error_Posted (Constr) then
1817 return False;
1818 end if;
1819
1820 case Nkind (Constr) is
1821 when N_Attribute_Reference =>
1822 return Attribute_Name (Constr) = Name_Access
1823 and then Prefix (Constr) = Scope (Entity (Prefix (Constr)));
1824
1825 when N_Discriminant_Association =>
1826 return Denotes_Discriminant (Expression (Constr));
1827
1828 when N_Identifier =>
1829 return Denotes_Discriminant (Constr);
1830
1831 when N_Index_Or_Discriminant_Constraint =>
1832 declare
1833 IDC : Node_Id;
1834
1835 begin
1836 IDC := First (Constraints (Constr));
1837 while Present (IDC) loop
1838
1839 -- One per-object constraint is sufficient
1840
1841 if Contains_POC (IDC) then
1842 return True;
1843 end if;
1844
1845 Next (IDC);
1846 end loop;
1847
1848 return False;
1849 end;
1850
1851 when N_Range =>
1852 return Denotes_Discriminant (Low_Bound (Constr))
1853 or else
1854 Denotes_Discriminant (High_Bound (Constr));
1855
1856 when N_Range_Constraint =>
1857 return Denotes_Discriminant (Range_Expression (Constr));
1858
1859 when others =>
1860 return False;
1861
1862 end case;
1863 end Contains_POC;
1864
1865 ----------------------
1866 -- Is_Known_Limited --
1867 ----------------------
1868
1869 function Is_Known_Limited (Typ : Entity_Id) return Boolean is
1870 P : constant Entity_Id := Etype (Typ);
1871 R : constant Entity_Id := Root_Type (Typ);
1872
1873 begin
1874 if Is_Limited_Record (Typ) then
1875 return True;
1876
1877 -- If the root type is limited (and not a limited interface)
1878 -- so is the current type
1879
1880 elsif Is_Limited_Record (R)
1881 and then (not Is_Interface (R) or else not Is_Limited_Interface (R))
1882 then
1883 return True;
1884
1885 -- Else the type may have a limited interface progenitor, but a
1886 -- limited record parent.
1887
1888 elsif R /= P and then Is_Limited_Record (P) then
1889 return True;
1890
1891 else
1892 return False;
1893 end if;
1894 end Is_Known_Limited;
1895
1896 -- Start of processing for Analyze_Component_Declaration
1897
1898 begin
1899 Generate_Definition (Id);
1900 Enter_Name (Id);
1901
1902 if Present (Typ) then
1903 T := Find_Type_Of_Object
1904 (Subtype_Indication (Component_Definition (N)), N);
1905
1906 if not Nkind_In (Typ, N_Identifier, N_Expanded_Name) then
1907 Check_SPARK_05_Restriction ("subtype mark required", Typ);
1908 end if;
1909
1910 -- Ada 2005 (AI-230): Access Definition case
1911
1912 else
1913 pragma Assert (Present
1914 (Access_Definition (Component_Definition (N))));
1915
1916 T := Access_Definition
1917 (Related_Nod => N,
1918 N => Access_Definition (Component_Definition (N)));
1919 Set_Is_Local_Anonymous_Access (T);
1920
1921 -- Ada 2005 (AI-254)
1922
1923 if Present (Access_To_Subprogram_Definition
1924 (Access_Definition (Component_Definition (N))))
1925 and then Protected_Present (Access_To_Subprogram_Definition
1926 (Access_Definition
1927 (Component_Definition (N))))
1928 then
1929 T := Replace_Anonymous_Access_To_Protected_Subprogram (N);
1930 end if;
1931 end if;
1932
1933 -- If the subtype is a constrained subtype of the enclosing record,
1934 -- (which must have a partial view) the back-end does not properly
1935 -- handle the recursion. Rewrite the component declaration with an
1936 -- explicit subtype indication, which is acceptable to Gigi. We can copy
1937 -- the tree directly because side effects have already been removed from
1938 -- discriminant constraints.
1939
1940 if Ekind (T) = E_Access_Subtype
1941 and then Is_Entity_Name (Subtype_Indication (Component_Definition (N)))
1942 and then Comes_From_Source (T)
1943 and then Nkind (Parent (T)) = N_Subtype_Declaration
1944 and then Etype (Directly_Designated_Type (T)) = Current_Scope
1945 then
1946 Rewrite
1947 (Subtype_Indication (Component_Definition (N)),
1948 New_Copy_Tree (Subtype_Indication (Parent (T))));
1949 T := Find_Type_Of_Object
1950 (Subtype_Indication (Component_Definition (N)), N);
1951 end if;
1952
1953 -- If the component declaration includes a default expression, then we
1954 -- check that the component is not of a limited type (RM 3.7(5)),
1955 -- and do the special preanalysis of the expression (see section on
1956 -- "Handling of Default and Per-Object Expressions" in the spec of
1957 -- package Sem).
1958
1959 if Present (E) then
1960 Check_SPARK_05_Restriction ("default expression is not allowed", E);
1961 Preanalyze_Default_Expression (E, T);
1962 Check_Initialization (T, E);
1963
1964 if Ada_Version >= Ada_2005
1965 and then Ekind (T) = E_Anonymous_Access_Type
1966 and then Etype (E) /= Any_Type
1967 then
1968 -- Check RM 3.9.2(9): "if the expected type for an expression is
1969 -- an anonymous access-to-specific tagged type, then the object
1970 -- designated by the expression shall not be dynamically tagged
1971 -- unless it is a controlling operand in a call on a dispatching
1972 -- operation"
1973
1974 if Is_Tagged_Type (Directly_Designated_Type (T))
1975 and then
1976 Ekind (Directly_Designated_Type (T)) /= E_Class_Wide_Type
1977 and then
1978 Ekind (Directly_Designated_Type (Etype (E))) =
1979 E_Class_Wide_Type
1980 then
1981 Error_Msg_N
1982 ("access to specific tagged type required (RM 3.9.2(9))", E);
1983 end if;
1984
1985 -- (Ada 2005: AI-230): Accessibility check for anonymous
1986 -- components
1987
1988 if Type_Access_Level (Etype (E)) >
1989 Deepest_Type_Access_Level (T)
1990 then
1991 Error_Msg_N
1992 ("expression has deeper access level than component " &
1993 "(RM 3.10.2 (12.2))", E);
1994 end if;
1995
1996 -- The initialization expression is a reference to an access
1997 -- discriminant. The type of the discriminant is always deeper
1998 -- than any access type.
1999
2000 if Ekind (Etype (E)) = E_Anonymous_Access_Type
2001 and then Is_Entity_Name (E)
2002 and then Ekind (Entity (E)) = E_In_Parameter
2003 and then Present (Discriminal_Link (Entity (E)))
2004 then
2005 Error_Msg_N
2006 ("discriminant has deeper accessibility level than target",
2007 E);
2008 end if;
2009 end if;
2010 end if;
2011
2012 -- The parent type may be a private view with unknown discriminants,
2013 -- and thus unconstrained. Regular components must be constrained.
2014
2015 if not Is_Definite_Subtype (T) and then Chars (Id) /= Name_uParent then
2016 if Is_Class_Wide_Type (T) then
2017 Error_Msg_N
2018 ("class-wide subtype with unknown discriminants" &
2019 " in component declaration",
2020 Subtype_Indication (Component_Definition (N)));
2021 else
2022 Error_Msg_N
2023 ("unconstrained subtype in component declaration",
2024 Subtype_Indication (Component_Definition (N)));
2025 end if;
2026
2027 -- Components cannot be abstract, except for the special case of
2028 -- the _Parent field (case of extending an abstract tagged type)
2029
2030 elsif Is_Abstract_Type (T) and then Chars (Id) /= Name_uParent then
2031 Error_Msg_N ("type of a component cannot be abstract", N);
2032 end if;
2033
2034 Set_Etype (Id, T);
2035 Set_Is_Aliased (Id, Aliased_Present (Component_Definition (N)));
2036
2037 -- The component declaration may have a per-object constraint, set
2038 -- the appropriate flag in the defining identifier of the subtype.
2039
2040 if Present (Subtype_Indication (Component_Definition (N))) then
2041 declare
2042 Sindic : constant Node_Id :=
2043 Subtype_Indication (Component_Definition (N));
2044 begin
2045 if Nkind (Sindic) = N_Subtype_Indication
2046 and then Present (Constraint (Sindic))
2047 and then Contains_POC (Constraint (Sindic))
2048 then
2049 Set_Has_Per_Object_Constraint (Id);
2050 end if;
2051 end;
2052 end if;
2053
2054 -- Ada 2005 (AI-231): Propagate the null-excluding attribute and carry
2055 -- out some static checks.
2056
2057 if Ada_Version >= Ada_2005 and then Can_Never_Be_Null (T) then
2058 Null_Exclusion_Static_Checks (N);
2059 end if;
2060
2061 -- If this component is private (or depends on a private type), flag the
2062 -- record type to indicate that some operations are not available.
2063
2064 P := Private_Component (T);
2065
2066 if Present (P) then
2067
2068 -- Check for circular definitions
2069
2070 if P = Any_Type then
2071 Set_Etype (Id, Any_Type);
2072
2073 -- There is a gap in the visibility of operations only if the
2074 -- component type is not defined in the scope of the record type.
2075
2076 elsif Scope (P) = Scope (Current_Scope) then
2077 null;
2078
2079 elsif Is_Limited_Type (P) then
2080 Set_Is_Limited_Composite (Current_Scope);
2081
2082 else
2083 Set_Is_Private_Composite (Current_Scope);
2084 end if;
2085 end if;
2086
2087 if P /= Any_Type
2088 and then Is_Limited_Type (T)
2089 and then Chars (Id) /= Name_uParent
2090 and then Is_Tagged_Type (Current_Scope)
2091 then
2092 if Is_Derived_Type (Current_Scope)
2093 and then not Is_Known_Limited (Current_Scope)
2094 then
2095 Error_Msg_N
2096 ("extension of nonlimited type cannot have limited components",
2097 N);
2098
2099 if Is_Interface (Root_Type (Current_Scope)) then
2100 Error_Msg_N
2101 ("\limitedness is not inherited from limited interface", N);
2102 Error_Msg_N ("\add LIMITED to type indication", N);
2103 end if;
2104
2105 Explain_Limited_Type (T, N);
2106 Set_Etype (Id, Any_Type);
2107 Set_Is_Limited_Composite (Current_Scope, False);
2108
2109 elsif not Is_Derived_Type (Current_Scope)
2110 and then not Is_Limited_Record (Current_Scope)
2111 and then not Is_Concurrent_Type (Current_Scope)
2112 then
2113 Error_Msg_N
2114 ("nonlimited tagged type cannot have limited components", N);
2115 Explain_Limited_Type (T, N);
2116 Set_Etype (Id, Any_Type);
2117 Set_Is_Limited_Composite (Current_Scope, False);
2118 end if;
2119 end if;
2120
2121 -- If the component is an unconstrained task or protected type with
2122 -- discriminants, the component and the enclosing record are limited
2123 -- and the component is constrained by its default values. Compute
2124 -- its actual subtype, else it may be allocated the maximum size by
2125 -- the backend, and possibly overflow.
2126
2127 if Is_Concurrent_Type (T)
2128 and then not Is_Constrained (T)
2129 and then Has_Discriminants (T)
2130 and then not Has_Discriminants (Current_Scope)
2131 then
2132 declare
2133 Act_T : constant Entity_Id := Build_Default_Subtype (T, N);
2134
2135 begin
2136 Set_Etype (Id, Act_T);
2137
2138 -- Rewrite component definition to use the constrained subtype
2139
2140 Rewrite (Component_Definition (N),
2141 Make_Component_Definition (Loc,
2142 Subtype_Indication => New_Occurrence_Of (Act_T, Loc)));
2143 end;
2144 end if;
2145
2146 Set_Original_Record_Component (Id, Id);
2147
2148 if Has_Aspects (N) then
2149 Analyze_Aspect_Specifications (N, Id);
2150 end if;
2151
2152 Analyze_Dimension (N);
2153 end Analyze_Component_Declaration;
2154
2155 --------------------------
2156 -- Analyze_Declarations --
2157 --------------------------
2158
2159 procedure Analyze_Declarations (L : List_Id) is
2160 Decl : Node_Id;
2161
2162 procedure Adjust_Decl;
2163 -- Adjust Decl not to include implicit label declarations, since these
2164 -- have strange Sloc values that result in elaboration check problems.
2165 -- (They have the sloc of the label as found in the source, and that
2166 -- is ahead of the current declarative part).
2167
2168 procedure Check_Entry_Contracts;
2169 -- Perform a pre-analysis of the pre- and postconditions of an entry
2170 -- declaration. This must be done before full resolution and creation
2171 -- of the parameter block, etc. to catch illegal uses within the
2172 -- contract expression. Full analysis of the expression is done when
2173 -- the contract is processed.
2174
2175 procedure Handle_Late_Controlled_Primitive (Body_Decl : Node_Id);
2176 -- Determine whether Body_Decl denotes the body of a late controlled
2177 -- primitive (either Initialize, Adjust or Finalize). If this is the
2178 -- case, add a proper spec if the body lacks one. The spec is inserted
2179 -- before Body_Decl and immedately analyzed.
2180
2181 procedure Remove_Visible_Refinements (Spec_Id : Entity_Id);
2182 -- Spec_Id is the entity of a package that may define abstract states.
2183 -- If the states have visible refinement, remove the visibility of each
2184 -- constituent at the end of the package body declarations.
2185
2186 -----------------
2187 -- Adjust_Decl --
2188 -----------------
2189
2190 procedure Adjust_Decl is
2191 begin
2192 while Present (Prev (Decl))
2193 and then Nkind (Decl) = N_Implicit_Label_Declaration
2194 loop
2195 Prev (Decl);
2196 end loop;
2197 end Adjust_Decl;
2198
2199 ---------------------------
2200 -- Check_Entry_Contracts --
2201 ---------------------------
2202
2203 procedure Check_Entry_Contracts is
2204 ASN : Node_Id;
2205 Ent : Entity_Id;
2206 Exp : Node_Id;
2207
2208 begin
2209 Ent := First_Entity (Current_Scope);
2210 while Present (Ent) loop
2211
2212 -- This only concerns entries with pre/postconditions
2213
2214 if Ekind (Ent) = E_Entry
2215 and then Present (Contract (Ent))
2216 and then Present (Pre_Post_Conditions (Contract (Ent)))
2217 then
2218 ASN := Pre_Post_Conditions (Contract (Ent));
2219 Push_Scope (Ent);
2220 Install_Formals (Ent);
2221
2222 -- Pre/postconditions are rewritten as Check pragmas. Analysis
2223 -- is performed on a copy of the pragma expression, to prevent
2224 -- modifying the original expression.
2225
2226 while Present (ASN) loop
2227 if Nkind (ASN) = N_Pragma then
2228 Exp :=
2229 New_Copy_Tree
2230 (Expression
2231 (First (Pragma_Argument_Associations (ASN))));
2232 Set_Parent (Exp, ASN);
2233
2234 -- ??? why not Preanalyze_Assert_Expression
2235
2236 Preanalyze (Exp);
2237 end if;
2238
2239 ASN := Next_Pragma (ASN);
2240 end loop;
2241
2242 End_Scope;
2243 end if;
2244
2245 Next_Entity (Ent);
2246 end loop;
2247 end Check_Entry_Contracts;
2248
2249 --------------------------------------
2250 -- Handle_Late_Controlled_Primitive --
2251 --------------------------------------
2252
2253 procedure Handle_Late_Controlled_Primitive (Body_Decl : Node_Id) is
2254 Body_Spec : constant Node_Id := Specification (Body_Decl);
2255 Body_Id : constant Entity_Id := Defining_Entity (Body_Spec);
2256 Loc : constant Source_Ptr := Sloc (Body_Id);
2257 Params : constant List_Id :=
2258 Parameter_Specifications (Body_Spec);
2259 Spec : Node_Id;
2260 Spec_Id : Entity_Id;
2261 Typ : Node_Id;
2262
2263 begin
2264 -- Consider only procedure bodies whose name matches one of the three
2265 -- controlled primitives.
2266
2267 if Nkind (Body_Spec) /= N_Procedure_Specification
2268 or else not Nam_In (Chars (Body_Id), Name_Adjust,
2269 Name_Finalize,
2270 Name_Initialize)
2271 then
2272 return;
2273
2274 -- A controlled primitive must have exactly one formal which is not
2275 -- an anonymous access type.
2276
2277 elsif List_Length (Params) /= 1 then
2278 return;
2279 end if;
2280
2281 Typ := Parameter_Type (First (Params));
2282
2283 if Nkind (Typ) = N_Access_Definition then
2284 return;
2285 end if;
2286
2287 Find_Type (Typ);
2288
2289 -- The type of the formal must be derived from [Limited_]Controlled
2290
2291 if not Is_Controlled (Entity (Typ)) then
2292 return;
2293 end if;
2294
2295 -- Check whether a specification exists for this body. We do not
2296 -- analyze the spec of the body in full, because it will be analyzed
2297 -- again when the body is properly analyzed, and we cannot create
2298 -- duplicate entries in the formals chain. We look for an explicit
2299 -- specification because the body may be an overriding operation and
2300 -- an inherited spec may be present.
2301
2302 Spec_Id := Current_Entity (Body_Id);
2303
2304 while Present (Spec_Id) loop
2305 if Ekind_In (Spec_Id, E_Procedure, E_Generic_Procedure)
2306 and then Scope (Spec_Id) = Current_Scope
2307 and then Present (First_Formal (Spec_Id))
2308 and then No (Next_Formal (First_Formal (Spec_Id)))
2309 and then Etype (First_Formal (Spec_Id)) = Entity (Typ)
2310 and then Comes_From_Source (Spec_Id)
2311 then
2312 return;
2313 end if;
2314
2315 Spec_Id := Homonym (Spec_Id);
2316 end loop;
2317
2318 -- At this point the body is known to be a late controlled primitive.
2319 -- Generate a matching spec and insert it before the body. Note the
2320 -- use of Copy_Separate_Tree - we want an entirely separate semantic
2321 -- tree in this case.
2322
2323 Spec := Copy_Separate_Tree (Body_Spec);
2324
2325 -- Ensure that the subprogram declaration does not inherit the null
2326 -- indicator from the body as we now have a proper spec/body pair.
2327
2328 Set_Null_Present (Spec, False);
2329
2330 Insert_Before_And_Analyze (Body_Decl,
2331 Make_Subprogram_Declaration (Loc, Specification => Spec));
2332 end Handle_Late_Controlled_Primitive;
2333
2334 --------------------------------
2335 -- Remove_Visible_Refinements --
2336 --------------------------------
2337
2338 procedure Remove_Visible_Refinements (Spec_Id : Entity_Id) is
2339 State_Elmt : Elmt_Id;
2340 begin
2341 if Present (Abstract_States (Spec_Id)) then
2342 State_Elmt := First_Elmt (Abstract_States (Spec_Id));
2343 while Present (State_Elmt) loop
2344 Set_Has_Visible_Refinement (Node (State_Elmt), False);
2345 Next_Elmt (State_Elmt);
2346 end loop;
2347 end if;
2348 end Remove_Visible_Refinements;
2349
2350 -- Local variables
2351
2352 Context : Node_Id := Empty;
2353 Freeze_From : Entity_Id := Empty;
2354 Next_Decl : Node_Id;
2355
2356 Body_Seen : Boolean := False;
2357 -- Flag set when the first body [stub] is encountered
2358
2359 -- Start of processing for Analyze_Declarations
2360
2361 begin
2362 if Restriction_Check_Required (SPARK_05) then
2363 Check_Later_Vs_Basic_Declarations (L, During_Parsing => False);
2364 end if;
2365
2366 Decl := First (L);
2367 while Present (Decl) loop
2368
2369 -- Package spec cannot contain a package declaration in SPARK
2370
2371 if Nkind (Decl) = N_Package_Declaration
2372 and then Nkind (Parent (L)) = N_Package_Specification
2373 then
2374 Check_SPARK_05_Restriction
2375 ("package specification cannot contain a package declaration",
2376 Decl);
2377 end if;
2378
2379 -- Complete analysis of declaration
2380
2381 Analyze (Decl);
2382 Next_Decl := Next (Decl);
2383
2384 if No (Freeze_From) then
2385 Freeze_From := First_Entity (Current_Scope);
2386 end if;
2387
2388 -- At the end of a declarative part, freeze remaining entities
2389 -- declared in it. The end of the visible declarations of package
2390 -- specification is not the end of a declarative part if private
2391 -- declarations are present. The end of a package declaration is a
2392 -- freezing point only if it a library package. A task definition or
2393 -- protected type definition is not a freeze point either. Finally,
2394 -- we do not freeze entities in generic scopes, because there is no
2395 -- code generated for them and freeze nodes will be generated for
2396 -- the instance.
2397
2398 -- The end of a package instantiation is not a freeze point, but
2399 -- for now we make it one, because the generic body is inserted
2400 -- (currently) immediately after. Generic instantiations will not
2401 -- be a freeze point once delayed freezing of bodies is implemented.
2402 -- (This is needed in any case for early instantiations ???).
2403
2404 if No (Next_Decl) then
2405 if Nkind (Parent (L)) = N_Component_List then
2406 null;
2407
2408 elsif Nkind_In (Parent (L), N_Protected_Definition,
2409 N_Task_Definition)
2410 then
2411 Check_Entry_Contracts;
2412
2413 elsif Nkind (Parent (L)) /= N_Package_Specification then
2414 if Nkind (Parent (L)) = N_Package_Body then
2415 Freeze_From := First_Entity (Current_Scope);
2416 end if;
2417
2418 -- There may have been several freezing points previously,
2419 -- for example object declarations or subprogram bodies, but
2420 -- at the end of a declarative part we check freezing from
2421 -- the beginning, even though entities may already be frozen,
2422 -- in order to perform visibility checks on delayed aspects.
2423
2424 Adjust_Decl;
2425 Freeze_All (First_Entity (Current_Scope), Decl);
2426 Freeze_From := Last_Entity (Current_Scope);
2427
2428 elsif Scope (Current_Scope) /= Standard_Standard
2429 and then not Is_Child_Unit (Current_Scope)
2430 and then No (Generic_Parent (Parent (L)))
2431 then
2432 null;
2433
2434 elsif L /= Visible_Declarations (Parent (L))
2435 or else No (Private_Declarations (Parent (L)))
2436 or else Is_Empty_List (Private_Declarations (Parent (L)))
2437 then
2438 Adjust_Decl;
2439 Freeze_All (First_Entity (Current_Scope), Decl);
2440 Freeze_From := Last_Entity (Current_Scope);
2441
2442 -- At the end of the visible declarations the expressions in
2443 -- aspects of all entities declared so far must be resolved.
2444 -- The entities themselves might be frozen later, and the
2445 -- generated pragmas and attribute definition clauses analyzed
2446 -- in full at that point, but name resolution must take place
2447 -- now.
2448 -- In addition to being the proper semantics, this is mandatory
2449 -- within generic units, because global name capture requires
2450 -- those expressions to be analyzed, given that the generated
2451 -- pragmas do not appear in the original generic tree.
2452
2453 elsif Serious_Errors_Detected = 0 then
2454 declare
2455 E : Entity_Id;
2456
2457 begin
2458 E := First_Entity (Current_Scope);
2459 while Present (E) loop
2460 Resolve_Aspect_Expressions (E);
2461 Next_Entity (E);
2462 end loop;
2463 end;
2464 end if;
2465
2466 -- If next node is a body then freeze all types before the body.
2467 -- An exception occurs for some expander-generated bodies. If these
2468 -- are generated at places where in general language rules would not
2469 -- allow a freeze point, then we assume that the expander has
2470 -- explicitly checked that all required types are properly frozen,
2471 -- and we do not cause general freezing here. This special circuit
2472 -- is used when the encountered body is marked as having already
2473 -- been analyzed.
2474
2475 -- In all other cases (bodies that come from source, and expander
2476 -- generated bodies that have not been analyzed yet), freeze all
2477 -- types now. Note that in the latter case, the expander must take
2478 -- care to attach the bodies at a proper place in the tree so as to
2479 -- not cause unwanted freezing at that point.
2480
2481 elsif not Analyzed (Next_Decl) and then Is_Body (Next_Decl) then
2482
2483 -- When a controlled type is frozen, the expander generates stream
2484 -- and controlled type support routines. If the freeze is caused
2485 -- by the stand alone body of Initialize, Adjust and Finalize, the
2486 -- expander will end up using the wrong version of these routines
2487 -- as the body has not been processed yet. To remedy this, detect
2488 -- a late controlled primitive and create a proper spec for it.
2489 -- This ensures that the primitive will override its inherited
2490 -- counterpart before the freeze takes place.
2491
2492 -- If the declaration we just processed is a body, do not attempt
2493 -- to examine Next_Decl as the late primitive idiom can only apply
2494 -- to the first encountered body.
2495
2496 -- The spec of the late primitive is not generated in ASIS mode to
2497 -- ensure a consistent list of primitives that indicates the true
2498 -- semantic structure of the program (which is not relevant when
2499 -- generating executable code.
2500
2501 -- ??? a cleaner approach may be possible and/or this solution
2502 -- could be extended to general-purpose late primitives, TBD.
2503
2504 if not ASIS_Mode and then not Body_Seen and then not Is_Body (Decl)
2505 then
2506 Body_Seen := True;
2507
2508 if Nkind (Next_Decl) = N_Subprogram_Body then
2509 Handle_Late_Controlled_Primitive (Next_Decl);
2510 end if;
2511 end if;
2512
2513 Adjust_Decl;
2514 Freeze_All (Freeze_From, Decl);
2515 Freeze_From := Last_Entity (Current_Scope);
2516 end if;
2517
2518 Decl := Next_Decl;
2519 end loop;
2520
2521 -- Analyze the contracts of packages and their bodies
2522
2523 if Present (L) then
2524 Context := Parent (L);
2525
2526 if Nkind (Context) = N_Package_Specification then
2527
2528 -- When a package has private declarations, its contract must be
2529 -- analyzed at the end of the said declarations. This way both the
2530 -- analysis and freeze actions are properly synchronized in case
2531 -- of private type use within the contract.
2532
2533 if L = Private_Declarations (Context) then
2534 Analyze_Package_Contract (Defining_Entity (Context));
2535
2536 -- Build the bodies of the default initial condition procedures
2537 -- for all types subject to pragma Default_Initial_Condition.
2538 -- From a purely Ada stand point, this is a freezing activity,
2539 -- however freezing is not available under GNATprove_Mode. To
2540 -- accomodate both scenarios, the bodies are build at the end
2541 -- of private declaration analysis.
2542
2543 Build_Default_Init_Cond_Procedure_Bodies (L);
2544
2545 -- Otherwise the contract is analyzed at the end of the visible
2546 -- declarations.
2547
2548 elsif L = Visible_Declarations (Context)
2549 and then No (Private_Declarations (Context))
2550 then
2551 Analyze_Package_Contract (Defining_Entity (Context));
2552 end if;
2553
2554 elsif Nkind (Context) = N_Package_Body then
2555 Analyze_Package_Body_Contract (Defining_Entity (Context));
2556 end if;
2557
2558 -- Analyze the contracts of various constructs now due to the delayed
2559 -- visibility needs of their aspects and pragmas.
2560
2561 Analyze_Contracts (L);
2562
2563 if Nkind (Context) = N_Package_Body then
2564
2565 -- Ensure that all abstract states and objects declared in the
2566 -- state space of a package body are utilized as constituents.
2567
2568 Check_Unused_Body_States (Defining_Entity (Context));
2569
2570 -- State refinements are visible up to the end of the package body
2571 -- declarations. Hide the state refinements from visibility to
2572 -- restore the original state conditions.
2573
2574 Remove_Visible_Refinements (Corresponding_Spec (Context));
2575 end if;
2576
2577 -- Verify that all abstract states found in any package declared in
2578 -- the input declarative list have proper refinements. The check is
2579 -- performed only when the context denotes a block, entry, package,
2580 -- protected, subprogram, or task body (SPARK RM 7.2.2(3)).
2581
2582 Check_State_Refinements (Context);
2583 end if;
2584 end Analyze_Declarations;
2585
2586 -----------------------------------
2587 -- Analyze_Full_Type_Declaration --
2588 -----------------------------------
2589
2590 procedure Analyze_Full_Type_Declaration (N : Node_Id) is
2591 Def : constant Node_Id := Type_Definition (N);
2592 Def_Id : constant Entity_Id := Defining_Identifier (N);
2593 T : Entity_Id;
2594 Prev : Entity_Id;
2595
2596 Is_Remote : constant Boolean :=
2597 (Is_Remote_Types (Current_Scope)
2598 or else Is_Remote_Call_Interface (Current_Scope))
2599 and then not (In_Private_Part (Current_Scope)
2600 or else In_Package_Body (Current_Scope));
2601
2602 procedure Check_Nonoverridable_Aspects;
2603 -- Apply the rule in RM 13.1.1(18.4/4) on iterator aspects that cannot
2604 -- be overridden, and can only be confirmed on derivation.
2605
2606 procedure Check_Ops_From_Incomplete_Type;
2607 -- If there is a tagged incomplete partial view of the type, traverse
2608 -- the primitives of the incomplete view and change the type of any
2609 -- controlling formals and result to indicate the full view. The
2610 -- primitives will be added to the full type's primitive operations
2611 -- list later in Sem_Disp.Check_Operation_From_Incomplete_Type (which
2612 -- is called from Process_Incomplete_Dependents).
2613
2614 ----------------------------------
2615 -- Check_Nonoverridable_Aspects --
2616 ----------------------------------
2617
2618 procedure Check_Nonoverridable_Aspects is
2619 Prev_Aspects : constant List_Id :=
2620 Aspect_Specifications (Parent (Def_Id));
2621 Par_Type : Entity_Id;
2622
2623 function Has_Aspect_Spec
2624 (Specs : List_Id;
2625 Aspect_Name : Name_Id) return Boolean;
2626 -- Check whether a list of aspect specifications includes an entry
2627 -- for a specific aspect. The list is either that of a partial or
2628 -- a full view.
2629
2630 ---------------------
2631 -- Has_Aspect_Spec --
2632 ---------------------
2633
2634 function Has_Aspect_Spec
2635 (Specs : List_Id;
2636 Aspect_Name : Name_Id) return Boolean
2637 is
2638 Spec : Node_Id;
2639 begin
2640 Spec := First (Specs);
2641 while Present (Spec) loop
2642 if Chars (Identifier (Spec)) = Aspect_Name then
2643 return True;
2644 end if;
2645 Next (Spec);
2646 end loop;
2647 return False;
2648 end Has_Aspect_Spec;
2649
2650 -- Start of processing for Check_Nonoverridable_Aspects
2651
2652 begin
2653
2654 -- Get parent type of derived type. Note that Prev is the entity
2655 -- in the partial declaration, but its contents are now those of
2656 -- full view, while Def_Id reflects the partial view.
2657
2658 if Is_Private_Type (Def_Id) then
2659 Par_Type := Etype (Full_View (Def_Id));
2660 else
2661 Par_Type := Etype (Def_Id);
2662 end if;
2663
2664 -- If there is an inherited Implicit_Dereference, verify that it is
2665 -- made explicit in the partial view.
2666
2667 if Has_Discriminants (Base_Type (Par_Type))
2668 and then Nkind (Parent (Prev)) = N_Full_Type_Declaration
2669 and then Present (Discriminant_Specifications (Parent (Prev)))
2670 and then Present (Get_Reference_Discriminant (Par_Type))
2671 then
2672 if
2673 not Has_Aspect_Spec (Prev_Aspects, Name_Implicit_Dereference)
2674 then
2675 Error_Msg_N
2676 ("type does not inherit implicit dereference", Prev);
2677
2678 else
2679 -- If one of the views has the aspect specified, verify that it
2680 -- is consistent with that of the parent.
2681
2682 declare
2683 Par_Discr : constant Entity_Id :=
2684 Get_Reference_Discriminant (Par_Type);
2685 Cur_Discr : constant Entity_Id :=
2686 Get_Reference_Discriminant (Prev);
2687 begin
2688 if Corresponding_Discriminant (Cur_Discr) /= Par_Discr then
2689 Error_Msg_N ("aspect incosistent with that of parent", N);
2690 end if;
2691 end;
2692 end if;
2693 end if;
2694
2695 -- TBD : other nonoverridable aspects.
2696 end Check_Nonoverridable_Aspects;
2697
2698 ------------------------------------
2699 -- Check_Ops_From_Incomplete_Type --
2700 ------------------------------------
2701
2702 procedure Check_Ops_From_Incomplete_Type is
2703 Elmt : Elmt_Id;
2704 Formal : Entity_Id;
2705 Op : Entity_Id;
2706
2707 begin
2708 if Prev /= T
2709 and then Ekind (Prev) = E_Incomplete_Type
2710 and then Is_Tagged_Type (Prev)
2711 and then Is_Tagged_Type (T)
2712 then
2713 Elmt := First_Elmt (Primitive_Operations (Prev));
2714 while Present (Elmt) loop
2715 Op := Node (Elmt);
2716
2717 Formal := First_Formal (Op);
2718 while Present (Formal) loop
2719 if Etype (Formal) = Prev then
2720 Set_Etype (Formal, T);
2721 end if;
2722
2723 Next_Formal (Formal);
2724 end loop;
2725
2726 if Etype (Op) = Prev then
2727 Set_Etype (Op, T);
2728 end if;
2729
2730 Next_Elmt (Elmt);
2731 end loop;
2732 end if;
2733 end Check_Ops_From_Incomplete_Type;
2734
2735 -- Start of processing for Analyze_Full_Type_Declaration
2736
2737 begin
2738 Prev := Find_Type_Name (N);
2739
2740 -- The full view, if present, now points to the current type. If there
2741 -- is an incomplete partial view, set a link to it, to simplify the
2742 -- retrieval of primitive operations of the type.
2743
2744 -- Ada 2005 (AI-50217): If the type was previously decorated when
2745 -- imported through a LIMITED WITH clause, it appears as incomplete
2746 -- but has no full view.
2747
2748 if Ekind (Prev) = E_Incomplete_Type
2749 and then Present (Full_View (Prev))
2750 then
2751 T := Full_View (Prev);
2752 Set_Incomplete_View (N, Parent (Prev));
2753 else
2754 T := Prev;
2755 end if;
2756
2757 Set_Is_Pure (T, Is_Pure (Current_Scope));
2758
2759 -- We set the flag Is_First_Subtype here. It is needed to set the
2760 -- corresponding flag for the Implicit class-wide-type created
2761 -- during tagged types processing.
2762
2763 Set_Is_First_Subtype (T, True);
2764
2765 -- Only composite types other than array types are allowed to have
2766 -- discriminants.
2767
2768 case Nkind (Def) is
2769
2770 -- For derived types, the rule will be checked once we've figured
2771 -- out the parent type.
2772
2773 when N_Derived_Type_Definition =>
2774 null;
2775
2776 -- For record types, discriminants are allowed, unless we are in
2777 -- SPARK.
2778
2779 when N_Record_Definition =>
2780 if Present (Discriminant_Specifications (N)) then
2781 Check_SPARK_05_Restriction
2782 ("discriminant type is not allowed",
2783 Defining_Identifier
2784 (First (Discriminant_Specifications (N))));
2785 end if;
2786
2787 when others =>
2788 if Present (Discriminant_Specifications (N)) then
2789 Error_Msg_N
2790 ("elementary or array type cannot have discriminants",
2791 Defining_Identifier
2792 (First (Discriminant_Specifications (N))));
2793 end if;
2794 end case;
2795
2796 -- Elaborate the type definition according to kind, and generate
2797 -- subsidiary (implicit) subtypes where needed. We skip this if it was
2798 -- already done (this happens during the reanalysis that follows a call
2799 -- to the high level optimizer).
2800
2801 if not Analyzed (T) then
2802 Set_Analyzed (T);
2803
2804 case Nkind (Def) is
2805 when N_Access_To_Subprogram_Definition =>
2806 Access_Subprogram_Declaration (T, Def);
2807
2808 -- If this is a remote access to subprogram, we must create the
2809 -- equivalent fat pointer type, and related subprograms.
2810
2811 if Is_Remote then
2812 Process_Remote_AST_Declaration (N);
2813 end if;
2814
2815 -- Validate categorization rule against access type declaration
2816 -- usually a violation in Pure unit, Shared_Passive unit.
2817
2818 Validate_Access_Type_Declaration (T, N);
2819
2820 when N_Access_To_Object_Definition =>
2821 Access_Type_Declaration (T, Def);
2822
2823 -- Validate categorization rule against access type declaration
2824 -- usually a violation in Pure unit, Shared_Passive unit.
2825
2826 Validate_Access_Type_Declaration (T, N);
2827
2828 -- If we are in a Remote_Call_Interface package and define a
2829 -- RACW, then calling stubs and specific stream attributes
2830 -- must be added.
2831
2832 if Is_Remote
2833 and then Is_Remote_Access_To_Class_Wide_Type (Def_Id)
2834 then
2835 Add_RACW_Features (Def_Id);
2836 end if;
2837
2838 when N_Array_Type_Definition =>
2839 Array_Type_Declaration (T, Def);
2840
2841 when N_Derived_Type_Definition =>
2842 Derived_Type_Declaration (T, N, T /= Def_Id);
2843
2844 when N_Enumeration_Type_Definition =>
2845 Enumeration_Type_Declaration (T, Def);
2846
2847 when N_Floating_Point_Definition =>
2848 Floating_Point_Type_Declaration (T, Def);
2849
2850 when N_Decimal_Fixed_Point_Definition =>
2851 Decimal_Fixed_Point_Type_Declaration (T, Def);
2852
2853 when N_Ordinary_Fixed_Point_Definition =>
2854 Ordinary_Fixed_Point_Type_Declaration (T, Def);
2855
2856 when N_Signed_Integer_Type_Definition =>
2857 Signed_Integer_Type_Declaration (T, Def);
2858
2859 when N_Modular_Type_Definition =>
2860 Modular_Type_Declaration (T, Def);
2861
2862 when N_Record_Definition =>
2863 Record_Type_Declaration (T, N, Prev);
2864
2865 -- If declaration has a parse error, nothing to elaborate.
2866
2867 when N_Error =>
2868 null;
2869
2870 when others =>
2871 raise Program_Error;
2872
2873 end case;
2874 end if;
2875
2876 if Etype (T) = Any_Type then
2877 return;
2878 end if;
2879
2880 -- Controlled type is not allowed in SPARK
2881
2882 if Is_Visibly_Controlled (T) then
2883 Check_SPARK_05_Restriction ("controlled type is not allowed", N);
2884 end if;
2885
2886 -- A type declared within a Ghost region is automatically Ghost
2887 -- (SPARK RM 6.9(2)).
2888
2889 if Ghost_Mode > None then
2890 Set_Is_Ghost_Entity (T);
2891 end if;
2892
2893 -- Some common processing for all types
2894
2895 Set_Depends_On_Private (T, Has_Private_Component (T));
2896 Check_Ops_From_Incomplete_Type;
2897
2898 -- Both the declared entity, and its anonymous base type if one was
2899 -- created, need freeze nodes allocated.
2900
2901 declare
2902 B : constant Entity_Id := Base_Type (T);
2903
2904 begin
2905 -- In the case where the base type differs from the first subtype, we
2906 -- pre-allocate a freeze node, and set the proper link to the first
2907 -- subtype. Freeze_Entity will use this preallocated freeze node when
2908 -- it freezes the entity.
2909
2910 -- This does not apply if the base type is a generic type, whose
2911 -- declaration is independent of the current derived definition.
2912
2913 if B /= T and then not Is_Generic_Type (B) then
2914 Ensure_Freeze_Node (B);
2915 Set_First_Subtype_Link (Freeze_Node (B), T);
2916 end if;
2917
2918 -- A type that is imported through a limited_with clause cannot
2919 -- generate any code, and thus need not be frozen. However, an access
2920 -- type with an imported designated type needs a finalization list,
2921 -- which may be referenced in some other package that has non-limited
2922 -- visibility on the designated type. Thus we must create the
2923 -- finalization list at the point the access type is frozen, to
2924 -- prevent unsatisfied references at link time.
2925
2926 if not From_Limited_With (T) or else Is_Access_Type (T) then
2927 Set_Has_Delayed_Freeze (T);
2928 end if;
2929 end;
2930
2931 -- Case where T is the full declaration of some private type which has
2932 -- been swapped in Defining_Identifier (N).
2933
2934 if T /= Def_Id and then Is_Private_Type (Def_Id) then
2935 Process_Full_View (N, T, Def_Id);
2936
2937 -- Record the reference. The form of this is a little strange, since
2938 -- the full declaration has been swapped in. So the first parameter
2939 -- here represents the entity to which a reference is made which is
2940 -- the "real" entity, i.e. the one swapped in, and the second
2941 -- parameter provides the reference location.
2942
2943 -- Also, we want to kill Has_Pragma_Unreferenced temporarily here
2944 -- since we don't want a complaint about the full type being an
2945 -- unwanted reference to the private type
2946
2947 declare
2948 B : constant Boolean := Has_Pragma_Unreferenced (T);
2949 begin
2950 Set_Has_Pragma_Unreferenced (T, False);
2951 Generate_Reference (T, T, 'c');
2952 Set_Has_Pragma_Unreferenced (T, B);
2953 end;
2954
2955 Set_Completion_Referenced (Def_Id);
2956
2957 -- For completion of incomplete type, process incomplete dependents
2958 -- and always mark the full type as referenced (it is the incomplete
2959 -- type that we get for any real reference).
2960
2961 elsif Ekind (Prev) = E_Incomplete_Type then
2962 Process_Incomplete_Dependents (N, T, Prev);
2963 Generate_Reference (Prev, Def_Id, 'c');
2964 Set_Completion_Referenced (Def_Id);
2965
2966 -- If not private type or incomplete type completion, this is a real
2967 -- definition of a new entity, so record it.
2968
2969 else
2970 Generate_Definition (Def_Id);
2971 end if;
2972
2973 -- Propagate any pending access types whose finalization masters need to
2974 -- be fully initialized from the partial to the full view. Guard against
2975 -- an illegal full view that remains unanalyzed.
2976
2977 if Is_Type (Def_Id) and then Is_Incomplete_Or_Private_Type (Prev) then
2978 Set_Pending_Access_Types (Def_Id, Pending_Access_Types (Prev));
2979 end if;
2980
2981 if Chars (Scope (Def_Id)) = Name_System
2982 and then Chars (Def_Id) = Name_Address
2983 and then Is_Predefined_File_Name (Unit_File_Name (Get_Source_Unit (N)))
2984 then
2985 Set_Is_Descendant_Of_Address (Def_Id);
2986 Set_Is_Descendant_Of_Address (Base_Type (Def_Id));
2987 Set_Is_Descendant_Of_Address (Prev);
2988 end if;
2989
2990 Set_Optimize_Alignment_Flags (Def_Id);
2991 Check_Eliminated (Def_Id);
2992
2993 -- If the declaration is a completion and aspects are present, apply
2994 -- them to the entity for the type which is currently the partial
2995 -- view, but which is the one that will be frozen.
2996
2997 if Has_Aspects (N) then
2998
2999 -- In most cases the partial view is a private type, and both views
3000 -- appear in different declarative parts. In the unusual case where
3001 -- the partial view is incomplete, perform the analysis on the
3002 -- full view, to prevent freezing anomalies with the corresponding
3003 -- class-wide type, which otherwise might be frozen before the
3004 -- dispatch table is built.
3005
3006 if Prev /= Def_Id
3007 and then Ekind (Prev) /= E_Incomplete_Type
3008 then
3009 Analyze_Aspect_Specifications (N, Prev);
3010
3011 -- Normal case
3012
3013 else
3014 Analyze_Aspect_Specifications (N, Def_Id);
3015 end if;
3016 end if;
3017
3018 if Is_Derived_Type (Prev)
3019 and then Def_Id /= Prev
3020 then
3021 Check_Nonoverridable_Aspects;
3022 end if;
3023 end Analyze_Full_Type_Declaration;
3024
3025 ----------------------------------
3026 -- Analyze_Incomplete_Type_Decl --
3027 ----------------------------------
3028
3029 procedure Analyze_Incomplete_Type_Decl (N : Node_Id) is
3030 F : constant Boolean := Is_Pure (Current_Scope);
3031 T : Entity_Id;
3032
3033 begin
3034 Check_SPARK_05_Restriction ("incomplete type is not allowed", N);
3035
3036 Generate_Definition (Defining_Identifier (N));
3037
3038 -- Process an incomplete declaration. The identifier must not have been
3039 -- declared already in the scope. However, an incomplete declaration may
3040 -- appear in the private part of a package, for a private type that has
3041 -- already been declared.
3042
3043 -- In this case, the discriminants (if any) must match
3044
3045 T := Find_Type_Name (N);
3046
3047 Set_Ekind (T, E_Incomplete_Type);
3048 Init_Size_Align (T);
3049 Set_Is_First_Subtype (T, True);
3050 Set_Etype (T, T);
3051
3052 -- An incomplete type declared within a Ghost region is automatically
3053 -- Ghost (SPARK RM 6.9(2)).
3054
3055 if Ghost_Mode > None then
3056 Set_Is_Ghost_Entity (T);
3057 end if;
3058
3059 -- Ada 2005 (AI-326): Minimum decoration to give support to tagged
3060 -- incomplete types.
3061
3062 if Tagged_Present (N) then
3063 Set_Is_Tagged_Type (T, True);
3064 Set_No_Tagged_Streams_Pragma (T, No_Tagged_Streams);
3065 Make_Class_Wide_Type (T);
3066 Set_Direct_Primitive_Operations (T, New_Elmt_List);
3067 end if;
3068
3069 Set_Stored_Constraint (T, No_Elist);
3070
3071 if Present (Discriminant_Specifications (N)) then
3072 Push_Scope (T);
3073 Process_Discriminants (N);
3074 End_Scope;
3075 end if;
3076
3077 -- If the type has discriminants, nontrivial subtypes may be declared
3078 -- before the full view of the type. The full views of those subtypes
3079 -- will be built after the full view of the type.
3080
3081 Set_Private_Dependents (T, New_Elmt_List);
3082 Set_Is_Pure (T, F);
3083 end Analyze_Incomplete_Type_Decl;
3084
3085 -----------------------------------
3086 -- Analyze_Interface_Declaration --
3087 -----------------------------------
3088
3089 procedure Analyze_Interface_Declaration (T : Entity_Id; Def : Node_Id) is
3090 CW : constant Entity_Id := Class_Wide_Type (T);
3091
3092 begin
3093 Set_Is_Tagged_Type (T);
3094 Set_No_Tagged_Streams_Pragma (T, No_Tagged_Streams);
3095
3096 Set_Is_Limited_Record (T, Limited_Present (Def)
3097 or else Task_Present (Def)
3098 or else Protected_Present (Def)
3099 or else Synchronized_Present (Def));
3100
3101 -- Type is abstract if full declaration carries keyword, or if previous
3102 -- partial view did.
3103
3104 Set_Is_Abstract_Type (T);
3105 Set_Is_Interface (T);
3106
3107 -- Type is a limited interface if it includes the keyword limited, task,
3108 -- protected, or synchronized.
3109
3110 Set_Is_Limited_Interface
3111 (T, Limited_Present (Def)
3112 or else Protected_Present (Def)
3113 or else Synchronized_Present (Def)
3114 or else Task_Present (Def));
3115
3116 Set_Interfaces (T, New_Elmt_List);
3117 Set_Direct_Primitive_Operations (T, New_Elmt_List);
3118
3119 -- Complete the decoration of the class-wide entity if it was already
3120 -- built (i.e. during the creation of the limited view)
3121
3122 if Present (CW) then
3123 Set_Is_Interface (CW);
3124 Set_Is_Limited_Interface (CW, Is_Limited_Interface (T));
3125 end if;
3126
3127 -- Check runtime support for synchronized interfaces
3128
3129 if (Is_Task_Interface (T)
3130 or else Is_Protected_Interface (T)
3131 or else Is_Synchronized_Interface (T))
3132 and then not RTE_Available (RE_Select_Specific_Data)
3133 then
3134 Error_Msg_CRT ("synchronized interfaces", T);
3135 end if;
3136 end Analyze_Interface_Declaration;
3137
3138 -----------------------------
3139 -- Analyze_Itype_Reference --
3140 -----------------------------
3141
3142 -- Nothing to do. This node is placed in the tree only for the benefit of
3143 -- back end processing, and has no effect on the semantic processing.
3144
3145 procedure Analyze_Itype_Reference (N : Node_Id) is
3146 begin
3147 pragma Assert (Is_Itype (Itype (N)));
3148 null;
3149 end Analyze_Itype_Reference;
3150
3151 --------------------------------
3152 -- Analyze_Number_Declaration --
3153 --------------------------------
3154
3155 procedure Analyze_Number_Declaration (N : Node_Id) is
3156 E : constant Node_Id := Expression (N);
3157 Id : constant Entity_Id := Defining_Identifier (N);
3158 Index : Interp_Index;
3159 It : Interp;
3160 T : Entity_Id;
3161
3162 begin
3163 Generate_Definition (Id);
3164 Enter_Name (Id);
3165
3166 -- A number declared within a Ghost region is automatically Ghost
3167 -- (SPARK RM 6.9(2)).
3168
3169 if Ghost_Mode > None then
3170 Set_Is_Ghost_Entity (Id);
3171 end if;
3172
3173 -- This is an optimization of a common case of an integer literal
3174
3175 if Nkind (E) = N_Integer_Literal then
3176 Set_Is_Static_Expression (E, True);
3177 Set_Etype (E, Universal_Integer);
3178
3179 Set_Etype (Id, Universal_Integer);
3180 Set_Ekind (Id, E_Named_Integer);
3181 Set_Is_Frozen (Id, True);
3182 return;
3183 end if;
3184
3185 Set_Is_Pure (Id, Is_Pure (Current_Scope));
3186
3187 -- Process expression, replacing error by integer zero, to avoid
3188 -- cascaded errors or aborts further along in the processing
3189
3190 -- Replace Error by integer zero, which seems least likely to cause
3191 -- cascaded errors.
3192
3193 if E = Error then
3194 Rewrite (E, Make_Integer_Literal (Sloc (E), Uint_0));
3195 Set_Error_Posted (E);
3196 end if;
3197
3198 Analyze (E);
3199
3200 -- Verify that the expression is static and numeric. If
3201 -- the expression is overloaded, we apply the preference
3202 -- rule that favors root numeric types.
3203
3204 if not Is_Overloaded (E) then
3205 T := Etype (E);
3206 if Has_Dynamic_Predicate_Aspect (T) then
3207 Error_Msg_N
3208 ("subtype has dynamic predicate, "
3209 & "not allowed in number declaration", N);
3210 end if;
3211
3212 else
3213 T := Any_Type;
3214
3215 Get_First_Interp (E, Index, It);
3216 while Present (It.Typ) loop
3217 if (Is_Integer_Type (It.Typ) or else Is_Real_Type (It.Typ))
3218 and then (Scope (Base_Type (It.Typ))) = Standard_Standard
3219 then
3220 if T = Any_Type then
3221 T := It.Typ;
3222
3223 elsif It.Typ = Universal_Real
3224 or else
3225 It.Typ = Universal_Integer
3226 then
3227 -- Choose universal interpretation over any other
3228
3229 T := It.Typ;
3230 exit;
3231 end if;
3232 end if;
3233
3234 Get_Next_Interp (Index, It);
3235 end loop;
3236 end if;
3237
3238 if Is_Integer_Type (T) then
3239 Resolve (E, T);
3240 Set_Etype (Id, Universal_Integer);
3241 Set_Ekind (Id, E_Named_Integer);
3242
3243 elsif Is_Real_Type (T) then
3244
3245 -- Because the real value is converted to universal_real, this is a
3246 -- legal context for a universal fixed expression.
3247
3248 if T = Universal_Fixed then
3249 declare
3250 Loc : constant Source_Ptr := Sloc (N);
3251 Conv : constant Node_Id := Make_Type_Conversion (Loc,
3252 Subtype_Mark =>
3253 New_Occurrence_Of (Universal_Real, Loc),
3254 Expression => Relocate_Node (E));
3255
3256 begin
3257 Rewrite (E, Conv);
3258 Analyze (E);
3259 end;
3260
3261 elsif T = Any_Fixed then
3262 Error_Msg_N ("illegal context for mixed mode operation", E);
3263
3264 -- Expression is of the form : universal_fixed * integer. Try to
3265 -- resolve as universal_real.
3266
3267 T := Universal_Real;
3268 Set_Etype (E, T);
3269 end if;
3270
3271 Resolve (E, T);
3272 Set_Etype (Id, Universal_Real);
3273 Set_Ekind (Id, E_Named_Real);
3274
3275 else
3276 Wrong_Type (E, Any_Numeric);
3277 Resolve (E, T);
3278
3279 Set_Etype (Id, T);
3280 Set_Ekind (Id, E_Constant);
3281 Set_Never_Set_In_Source (Id, True);
3282 Set_Is_True_Constant (Id, True);
3283 return;
3284 end if;
3285
3286 if Nkind_In (E, N_Integer_Literal, N_Real_Literal) then
3287 Set_Etype (E, Etype (Id));
3288 end if;
3289
3290 if not Is_OK_Static_Expression (E) then
3291 Flag_Non_Static_Expr
3292 ("non-static expression used in number declaration!", E);
3293 Rewrite (E, Make_Integer_Literal (Sloc (N), 1));
3294 Set_Etype (E, Any_Type);
3295 end if;
3296
3297 Analyze_Dimension (N);
3298 end Analyze_Number_Declaration;
3299
3300 --------------------------------
3301 -- Analyze_Object_Declaration --
3302 --------------------------------
3303
3304 procedure Analyze_Object_Declaration (N : Node_Id) is
3305 Loc : constant Source_Ptr := Sloc (N);
3306 Id : constant Entity_Id := Defining_Identifier (N);
3307 Act_T : Entity_Id;
3308 T : Entity_Id;
3309
3310 E : Node_Id := Expression (N);
3311 -- E is set to Expression (N) throughout this routine. When
3312 -- Expression (N) is modified, E is changed accordingly.
3313
3314 Prev_Entity : Entity_Id := Empty;
3315
3316 function Count_Tasks (T : Entity_Id) return Uint;
3317 -- This function is called when a non-generic library level object of a
3318 -- task type is declared. Its function is to count the static number of
3319 -- tasks declared within the type (it is only called if Has_Task is set
3320 -- for T). As a side effect, if an array of tasks with non-static bounds
3321 -- or a variant record type is encountered, Check_Restriction is called
3322 -- indicating the count is unknown.
3323
3324 function Delayed_Aspect_Present return Boolean;
3325 -- If the declaration has an expression that is an aggregate, and it
3326 -- has aspects that require delayed analysis, the resolution of the
3327 -- aggregate must be deferred to the freeze point of the objet. This
3328 -- special processing was created for address clauses, but it must
3329 -- also apply to Alignment. This must be done before the aspect
3330 -- specifications are analyzed because we must handle the aggregate
3331 -- before the analysis of the object declaration is complete.
3332
3333 -- Any other relevant delayed aspects on object declarations ???
3334
3335 -----------------
3336 -- Count_Tasks --
3337 -----------------
3338
3339 function Count_Tasks (T : Entity_Id) return Uint is
3340 C : Entity_Id;
3341 X : Node_Id;
3342 V : Uint;
3343
3344 begin
3345 if Is_Task_Type (T) then
3346 return Uint_1;
3347
3348 elsif Is_Record_Type (T) then
3349 if Has_Discriminants (T) then
3350 Check_Restriction (Max_Tasks, N);
3351 return Uint_0;
3352
3353 else
3354 V := Uint_0;
3355 C := First_Component (T);
3356 while Present (C) loop
3357 V := V + Count_Tasks (Etype (C));
3358 Next_Component (C);
3359 end loop;
3360
3361 return V;
3362 end if;
3363
3364 elsif Is_Array_Type (T) then
3365 X := First_Index (T);
3366 V := Count_Tasks (Component_Type (T));
3367 while Present (X) loop
3368 C := Etype (X);
3369
3370 if not Is_OK_Static_Subtype (C) then
3371 Check_Restriction (Max_Tasks, N);
3372 return Uint_0;
3373 else
3374 V := V * (UI_Max (Uint_0,
3375 Expr_Value (Type_High_Bound (C)) -
3376 Expr_Value (Type_Low_Bound (C)) + Uint_1));
3377 end if;
3378
3379 Next_Index (X);
3380 end loop;
3381
3382 return V;
3383
3384 else
3385 return Uint_0;
3386 end if;
3387 end Count_Tasks;
3388
3389 ----------------------------
3390 -- Delayed_Aspect_Present --
3391 ----------------------------
3392
3393 function Delayed_Aspect_Present return Boolean is
3394 A : Node_Id;
3395 A_Id : Aspect_Id;
3396
3397 begin
3398 if Present (Aspect_Specifications (N)) then
3399 A := First (Aspect_Specifications (N));
3400 A_Id := Get_Aspect_Id (Chars (Identifier (A)));
3401 while Present (A) loop
3402 if A_Id = Aspect_Alignment or else A_Id = Aspect_Address then
3403 return True;
3404 end if;
3405
3406 Next (A);
3407 end loop;
3408 end if;
3409
3410 return False;
3411 end Delayed_Aspect_Present;
3412
3413 -- Local variables
3414
3415 Save_Ghost_Mode : constant Ghost_Mode_Type := Ghost_Mode;
3416 Related_Id : Entity_Id;
3417
3418 -- Start of processing for Analyze_Object_Declaration
3419
3420 begin
3421 -- There are three kinds of implicit types generated by an
3422 -- object declaration:
3423
3424 -- 1. Those generated by the original Object Definition
3425
3426 -- 2. Those generated by the Expression
3427
3428 -- 3. Those used to constrain the Object Definition with the
3429 -- expression constraints when the definition is unconstrained.
3430
3431 -- They must be generated in this order to avoid order of elaboration
3432 -- issues. Thus the first step (after entering the name) is to analyze
3433 -- the object definition.
3434
3435 if Constant_Present (N) then
3436 Prev_Entity := Current_Entity_In_Scope (Id);
3437
3438 if Present (Prev_Entity)
3439 and then
3440 -- If the homograph is an implicit subprogram, it is overridden
3441 -- by the current declaration.
3442
3443 ((Is_Overloadable (Prev_Entity)
3444 and then Is_Inherited_Operation (Prev_Entity))
3445
3446 -- The current object is a discriminal generated for an entry
3447 -- family index. Even though the index is a constant, in this
3448 -- particular context there is no true constant redeclaration.
3449 -- Enter_Name will handle the visibility.
3450
3451 or else
3452 (Is_Discriminal (Id)
3453 and then Ekind (Discriminal_Link (Id)) =
3454 E_Entry_Index_Parameter)
3455
3456 -- The current object is the renaming for a generic declared
3457 -- within the instance.
3458
3459 or else
3460 (Ekind (Prev_Entity) = E_Package
3461 and then Nkind (Parent (Prev_Entity)) =
3462 N_Package_Renaming_Declaration
3463 and then not Comes_From_Source (Prev_Entity)
3464 and then
3465 Is_Generic_Instance (Renamed_Entity (Prev_Entity)))
3466
3467 -- The entity may be a homonym of a private component of the
3468 -- enclosing protected object, for which we create a local
3469 -- renaming declaration. The declaration is legal, even if
3470 -- useless when it just captures that component.
3471
3472 or else
3473 (Ekind (Scope (Current_Scope)) = E_Protected_Type
3474 and then Nkind (Parent (Prev_Entity)) =
3475 N_Object_Renaming_Declaration))
3476 then
3477 Prev_Entity := Empty;
3478 end if;
3479 end if;
3480
3481 -- The object declaration is Ghost when it is subject to pragma Ghost or
3482 -- completes a deferred Ghost constant. Set the mode now to ensure that
3483 -- any nodes generated during analysis and expansion are properly marked
3484 -- as Ghost.
3485
3486 Set_Ghost_Mode (N, Prev_Entity);
3487
3488 if Present (Prev_Entity) then
3489 Constant_Redeclaration (Id, N, T);
3490
3491 Generate_Reference (Prev_Entity, Id, 'c');
3492 Set_Completion_Referenced (Id);
3493
3494 if Error_Posted (N) then
3495
3496 -- Type mismatch or illegal redeclaration; do not analyze
3497 -- expression to avoid cascaded errors.
3498
3499 T := Find_Type_Of_Object (Object_Definition (N), N);
3500 Set_Etype (Id, T);
3501 Set_Ekind (Id, E_Variable);
3502 goto Leave;
3503 end if;
3504
3505 -- In the normal case, enter identifier at the start to catch premature
3506 -- usage in the initialization expression.
3507
3508 else
3509 Generate_Definition (Id);
3510 Enter_Name (Id);
3511
3512 Mark_Coextensions (N, Object_Definition (N));
3513
3514 T := Find_Type_Of_Object (Object_Definition (N), N);
3515
3516 if Nkind (Object_Definition (N)) = N_Access_Definition
3517 and then Present
3518 (Access_To_Subprogram_Definition (Object_Definition (N)))
3519 and then Protected_Present
3520 (Access_To_Subprogram_Definition (Object_Definition (N)))
3521 then
3522 T := Replace_Anonymous_Access_To_Protected_Subprogram (N);
3523 end if;
3524
3525 if Error_Posted (Id) then
3526 Set_Etype (Id, T);
3527 Set_Ekind (Id, E_Variable);
3528 goto Leave;
3529 end if;
3530 end if;
3531
3532 -- Ada 2005 (AI-231): Propagate the null-excluding attribute and carry
3533 -- out some static checks.
3534
3535 if Ada_Version >= Ada_2005 and then Can_Never_Be_Null (T) then
3536
3537 -- In case of aggregates we must also take care of the correct
3538 -- initialization of nested aggregates bug this is done at the
3539 -- point of the analysis of the aggregate (see sem_aggr.adb) ???
3540
3541 if Present (Expression (N))
3542 and then Nkind (Expression (N)) = N_Aggregate
3543 then
3544 null;
3545
3546 else
3547 declare
3548 Save_Typ : constant Entity_Id := Etype (Id);
3549 begin
3550 Set_Etype (Id, T); -- Temp. decoration for static checks
3551 Null_Exclusion_Static_Checks (N);
3552 Set_Etype (Id, Save_Typ);
3553 end;
3554 end if;
3555 end if;
3556
3557 -- Object is marked pure if it is in a pure scope
3558
3559 Set_Is_Pure (Id, Is_Pure (Current_Scope));
3560
3561 -- If deferred constant, make sure context is appropriate. We detect
3562 -- a deferred constant as a constant declaration with no expression.
3563 -- A deferred constant can appear in a package body if its completion
3564 -- is by means of an interface pragma.
3565
3566 if Constant_Present (N) and then No (E) then
3567
3568 -- A deferred constant may appear in the declarative part of the
3569 -- following constructs:
3570
3571 -- blocks
3572 -- entry bodies
3573 -- extended return statements
3574 -- package specs
3575 -- package bodies
3576 -- subprogram bodies
3577 -- task bodies
3578
3579 -- When declared inside a package spec, a deferred constant must be
3580 -- completed by a full constant declaration or pragma Import. In all
3581 -- other cases, the only proper completion is pragma Import. Extended
3582 -- return statements are flagged as invalid contexts because they do
3583 -- not have a declarative part and so cannot accommodate the pragma.
3584
3585 if Ekind (Current_Scope) = E_Return_Statement then
3586 Error_Msg_N
3587 ("invalid context for deferred constant declaration (RM 7.4)",
3588 N);
3589 Error_Msg_N
3590 ("\declaration requires an initialization expression",
3591 N);
3592 Set_Constant_Present (N, False);
3593
3594 -- In Ada 83, deferred constant must be of private type
3595
3596 elsif not Is_Private_Type (T) then
3597 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
3598 Error_Msg_N
3599 ("(Ada 83) deferred constant must be private type", N);
3600 end if;
3601 end if;
3602
3603 -- If not a deferred constant, then the object declaration freezes
3604 -- its type, unless the object is of an anonymous type and has delayed
3605 -- aspects. In that case the type is frozen when the object itself is.
3606
3607 else
3608 Check_Fully_Declared (T, N);
3609
3610 if Has_Delayed_Aspects (Id)
3611 and then Is_Array_Type (T)
3612 and then Is_Itype (T)
3613 then
3614 Set_Has_Delayed_Freeze (T);
3615 else
3616 Freeze_Before (N, T);
3617 end if;
3618 end if;
3619
3620 -- If the object was created by a constrained array definition, then
3621 -- set the link in both the anonymous base type and anonymous subtype
3622 -- that are built to represent the array type to point to the object.
3623
3624 if Nkind (Object_Definition (Declaration_Node (Id))) =
3625 N_Constrained_Array_Definition
3626 then
3627 Set_Related_Array_Object (T, Id);
3628 Set_Related_Array_Object (Base_Type (T), Id);
3629 end if;
3630
3631 -- Special checks for protected objects not at library level
3632
3633 if Has_Protected (T) and then not Is_Library_Level_Entity (Id) then
3634 Check_Restriction (No_Local_Protected_Objects, Id);
3635
3636 -- Protected objects with interrupt handlers must be at library level
3637
3638 -- Ada 2005: This test is not needed (and the corresponding clause
3639 -- in the RM is removed) because accessibility checks are sufficient
3640 -- to make handlers not at the library level illegal.
3641
3642 -- AI05-0303: The AI is in fact a binding interpretation, and thus
3643 -- applies to the '95 version of the language as well.
3644
3645 if Is_Protected_Type (T)
3646 and then Has_Interrupt_Handler (T)
3647 and then Ada_Version < Ada_95
3648 then
3649 Error_Msg_N
3650 ("interrupt object can only be declared at library level", Id);
3651 end if;
3652 end if;
3653
3654 -- Check for violation of No_Local_Timing_Events
3655
3656 if Has_Timing_Event (T) and then not Is_Library_Level_Entity (Id) then
3657 Check_Restriction (No_Local_Timing_Events, Id);
3658 end if;
3659
3660 -- The actual subtype of the object is the nominal subtype, unless
3661 -- the nominal one is unconstrained and obtained from the expression.
3662
3663 Act_T := T;
3664
3665 -- These checks should be performed before the initialization expression
3666 -- is considered, so that the Object_Definition node is still the same
3667 -- as in source code.
3668
3669 -- In SPARK, the nominal subtype is always given by a subtype mark
3670 -- and must not be unconstrained. (The only exception to this is the
3671 -- acceptance of declarations of constants of type String.)
3672
3673 if not Nkind_In (Object_Definition (N), N_Expanded_Name, N_Identifier)
3674 then
3675 Check_SPARK_05_Restriction
3676 ("subtype mark required", Object_Definition (N));
3677
3678 elsif Is_Array_Type (T)
3679 and then not Is_Constrained (T)
3680 and then T /= Standard_String
3681 then
3682 Check_SPARK_05_Restriction
3683 ("subtype mark of constrained type expected",
3684 Object_Definition (N));
3685 end if;
3686
3687 -- There are no aliased objects in SPARK
3688
3689 if Aliased_Present (N) then
3690 Check_SPARK_05_Restriction ("aliased object is not allowed", N);
3691 end if;
3692
3693 -- Process initialization expression if present and not in error
3694
3695 if Present (E) and then E /= Error then
3696
3697 -- Generate an error in case of CPP class-wide object initialization.
3698 -- Required because otherwise the expansion of the class-wide
3699 -- assignment would try to use 'size to initialize the object
3700 -- (primitive that is not available in CPP tagged types).
3701
3702 if Is_Class_Wide_Type (Act_T)
3703 and then
3704 (Is_CPP_Class (Root_Type (Etype (Act_T)))
3705 or else
3706 (Present (Full_View (Root_Type (Etype (Act_T))))
3707 and then
3708 Is_CPP_Class (Full_View (Root_Type (Etype (Act_T))))))
3709 then
3710 Error_Msg_N
3711 ("predefined assignment not available for 'C'P'P tagged types",
3712 E);
3713 end if;
3714
3715 Mark_Coextensions (N, E);
3716 Analyze (E);
3717
3718 -- In case of errors detected in the analysis of the expression,
3719 -- decorate it with the expected type to avoid cascaded errors
3720
3721 if No (Etype (E)) then
3722 Set_Etype (E, T);
3723 end if;
3724
3725 -- If an initialization expression is present, then we set the
3726 -- Is_True_Constant flag. It will be reset if this is a variable
3727 -- and it is indeed modified.
3728
3729 Set_Is_True_Constant (Id, True);
3730
3731 -- If we are analyzing a constant declaration, set its completion
3732 -- flag after analyzing and resolving the expression.
3733
3734 if Constant_Present (N) then
3735 Set_Has_Completion (Id);
3736 end if;
3737
3738 -- Set type and resolve (type may be overridden later on). Note:
3739 -- Ekind (Id) must still be E_Void at this point so that incorrect
3740 -- early usage within E is properly diagnosed.
3741
3742 Set_Etype (Id, T);
3743
3744 -- If the expression is an aggregate we must look ahead to detect
3745 -- the possible presence of an address clause, and defer resolution
3746 -- and expansion of the aggregate to the freeze point of the entity.
3747
3748 -- This is not always legal because the aggregate may contain other
3749 -- references that need freezing, e.g. references to other entities
3750 -- with address clauses. In any case, when compiling with -gnatI the
3751 -- presence of the address clause must be ignored.
3752
3753 if Comes_From_Source (N)
3754 and then Expander_Active
3755 and then Nkind (E) = N_Aggregate
3756 and then
3757 ((Present (Following_Address_Clause (N))
3758 and then not Ignore_Rep_Clauses)
3759 or else Delayed_Aspect_Present)
3760 then
3761 Set_Etype (E, T);
3762
3763 else
3764 Resolve (E, T);
3765 end if;
3766
3767 -- No further action needed if E is a call to an inlined function
3768 -- which returns an unconstrained type and it has been expanded into
3769 -- a procedure call. In that case N has been replaced by an object
3770 -- declaration without initializing expression and it has been
3771 -- analyzed (see Expand_Inlined_Call).
3772
3773 if Back_End_Inlining
3774 and then Expander_Active
3775 and then Nkind (E) = N_Function_Call
3776 and then Nkind (Name (E)) in N_Has_Entity
3777 and then Is_Inlined (Entity (Name (E)))
3778 and then not Is_Constrained (Etype (E))
3779 and then Analyzed (N)
3780 and then No (Expression (N))
3781 then
3782 Ghost_Mode := Save_Ghost_Mode;
3783 return;
3784 end if;
3785
3786 -- If E is null and has been replaced by an N_Raise_Constraint_Error
3787 -- node (which was marked already-analyzed), we need to set the type
3788 -- to something other than Any_Access in order to keep gigi happy.
3789
3790 if Etype (E) = Any_Access then
3791 Set_Etype (E, T);
3792 end if;
3793
3794 -- If the object is an access to variable, the initialization
3795 -- expression cannot be an access to constant.
3796
3797 if Is_Access_Type (T)
3798 and then not Is_Access_Constant (T)
3799 and then Is_Access_Type (Etype (E))
3800 and then Is_Access_Constant (Etype (E))
3801 then
3802 Error_Msg_N
3803 ("access to variable cannot be initialized with an "
3804 & "access-to-constant expression", E);
3805 end if;
3806
3807 if not Assignment_OK (N) then
3808 Check_Initialization (T, E);
3809 end if;
3810
3811 Check_Unset_Reference (E);
3812
3813 -- If this is a variable, then set current value. If this is a
3814 -- declared constant of a scalar type with a static expression,
3815 -- indicate that it is always valid.
3816
3817 if not Constant_Present (N) then
3818 if Compile_Time_Known_Value (E) then
3819 Set_Current_Value (Id, E);
3820 end if;
3821
3822 elsif Is_Scalar_Type (T) and then Is_OK_Static_Expression (E) then
3823 Set_Is_Known_Valid (Id);
3824 end if;
3825
3826 -- Deal with setting of null flags
3827
3828 if Is_Access_Type (T) then
3829 if Known_Non_Null (E) then
3830 Set_Is_Known_Non_Null (Id, True);
3831 elsif Known_Null (E) and then not Can_Never_Be_Null (Id) then
3832 Set_Is_Known_Null (Id, True);
3833 end if;
3834 end if;
3835
3836 -- Check incorrect use of dynamically tagged expressions
3837
3838 if Is_Tagged_Type (T) then
3839 Check_Dynamically_Tagged_Expression
3840 (Expr => E,
3841 Typ => T,
3842 Related_Nod => N);
3843 end if;
3844
3845 Apply_Scalar_Range_Check (E, T);
3846 Apply_Static_Length_Check (E, T);
3847
3848 if Nkind (Original_Node (N)) = N_Object_Declaration
3849 and then Comes_From_Source (Original_Node (N))
3850
3851 -- Only call test if needed
3852
3853 and then Restriction_Check_Required (SPARK_05)
3854 and then not Is_SPARK_05_Initialization_Expr (Original_Node (E))
3855 then
3856 Check_SPARK_05_Restriction
3857 ("initialization expression is not appropriate", E);
3858 end if;
3859
3860 -- A formal parameter of a specific tagged type whose related
3861 -- subprogram is subject to pragma Extensions_Visible with value
3862 -- "False" cannot be implicitly converted to a class-wide type by
3863 -- means of an initialization expression (SPARK RM 6.1.7(3)). Do
3864 -- not consider internally generated expressions.
3865
3866 if Is_Class_Wide_Type (T)
3867 and then Comes_From_Source (E)
3868 and then Is_EVF_Expression (E)
3869 then
3870 Error_Msg_N
3871 ("formal parameter cannot be implicitly converted to "
3872 & "class-wide type when Extensions_Visible is False", E);
3873 end if;
3874 end if;
3875
3876 -- If the No_Streams restriction is set, check that the type of the
3877 -- object is not, and does not contain, any subtype derived from
3878 -- Ada.Streams.Root_Stream_Type. Note that we guard the call to
3879 -- Has_Stream just for efficiency reasons. There is no point in
3880 -- spending time on a Has_Stream check if the restriction is not set.
3881
3882 if Restriction_Check_Required (No_Streams) then
3883 if Has_Stream (T) then
3884 Check_Restriction (No_Streams, N);
3885 end if;
3886 end if;
3887
3888 -- Deal with predicate check before we start to do major rewriting. It
3889 -- is OK to initialize and then check the initialized value, since the
3890 -- object goes out of scope if we get a predicate failure. Note that we
3891 -- do this in the analyzer and not the expander because the analyzer
3892 -- does some substantial rewriting in some cases.
3893
3894 -- We need a predicate check if the type has predicates that are not
3895 -- ignored, and if either there is an initializing expression, or for
3896 -- default initialization when we have at least one case of an explicit
3897 -- default initial value and then this is not an internal declaration
3898 -- whose initialization comes later (as for an aggregate expansion).
3899
3900 if not Suppress_Assignment_Checks (N)
3901 and then Present (Predicate_Function (T))
3902 and then not Predicates_Ignored (T)
3903 and then not No_Initialization (N)
3904 and then
3905 (Present (E)
3906 or else
3907 Is_Partially_Initialized_Type (T, Include_Implicit => False))
3908 then
3909 -- If the type has a static predicate and the expression is known at
3910 -- compile time, see if the expression satisfies the predicate.
3911
3912 if Present (E) then
3913 Check_Expression_Against_Static_Predicate (E, T);
3914 end if;
3915
3916 -- If the type is a null record and there is no explicit initial
3917 -- expression, no predicate check applies.
3918
3919 if No (E) and then Is_Null_Record_Type (T) then
3920 null;
3921
3922 else
3923 Insert_After (N,
3924 Make_Predicate_Check (T, New_Occurrence_Of (Id, Loc)));
3925 end if;
3926 end if;
3927
3928 -- Case of unconstrained type
3929
3930 if not Is_Definite_Subtype (T) then
3931
3932 -- In SPARK, a declaration of unconstrained type is allowed
3933 -- only for constants of type string.
3934
3935 if Is_String_Type (T) and then not Constant_Present (N) then
3936 Check_SPARK_05_Restriction
3937 ("declaration of object of unconstrained type not allowed", N);
3938 end if;
3939
3940 -- Nothing to do in deferred constant case
3941
3942 if Constant_Present (N) and then No (E) then
3943 null;
3944
3945 -- Case of no initialization present
3946
3947 elsif No (E) then
3948 if No_Initialization (N) then
3949 null;
3950
3951 elsif Is_Class_Wide_Type (T) then
3952 Error_Msg_N
3953 ("initialization required in class-wide declaration ", N);
3954
3955 else
3956 Error_Msg_N
3957 ("unconstrained subtype not allowed (need initialization)",
3958 Object_Definition (N));
3959
3960 if Is_Record_Type (T) and then Has_Discriminants (T) then
3961 Error_Msg_N
3962 ("\provide initial value or explicit discriminant values",
3963 Object_Definition (N));
3964
3965 Error_Msg_NE
3966 ("\or give default discriminant values for type&",
3967 Object_Definition (N), T);
3968
3969 elsif Is_Array_Type (T) then
3970 Error_Msg_N
3971 ("\provide initial value or explicit array bounds",
3972 Object_Definition (N));
3973 end if;
3974 end if;
3975
3976 -- Case of initialization present but in error. Set initial
3977 -- expression as absent (but do not make above complaints)
3978
3979 elsif E = Error then
3980 Set_Expression (N, Empty);
3981 E := Empty;
3982
3983 -- Case of initialization present
3984
3985 else
3986 -- Check restrictions in Ada 83
3987
3988 if not Constant_Present (N) then
3989
3990 -- Unconstrained variables not allowed in Ada 83 mode
3991
3992 if Ada_Version = Ada_83
3993 and then Comes_From_Source (Object_Definition (N))
3994 then
3995 Error_Msg_N
3996 ("(Ada 83) unconstrained variable not allowed",
3997 Object_Definition (N));
3998 end if;
3999 end if;
4000
4001 -- Now we constrain the variable from the initializing expression
4002
4003 -- If the expression is an aggregate, it has been expanded into
4004 -- individual assignments. Retrieve the actual type from the
4005 -- expanded construct.
4006
4007 if Is_Array_Type (T)
4008 and then No_Initialization (N)
4009 and then Nkind (Original_Node (E)) = N_Aggregate
4010 then
4011 Act_T := Etype (E);
4012
4013 -- In case of class-wide interface object declarations we delay
4014 -- the generation of the equivalent record type declarations until
4015 -- its expansion because there are cases in they are not required.
4016
4017 elsif Is_Interface (T) then
4018 null;
4019
4020 -- In GNATprove mode, Expand_Subtype_From_Expr does nothing. Thus,
4021 -- we should prevent the generation of another Itype with the
4022 -- same name as the one already generated, or we end up with
4023 -- two identical types in GNATprove.
4024
4025 elsif GNATprove_Mode then
4026 null;
4027
4028 -- If the type is an unchecked union, no subtype can be built from
4029 -- the expression. Rewrite declaration as a renaming, which the
4030 -- back-end can handle properly. This is a rather unusual case,
4031 -- because most unchecked_union declarations have default values
4032 -- for discriminants and are thus not indefinite.
4033
4034 elsif Is_Unchecked_Union (T) then
4035 if Constant_Present (N) or else Nkind (E) = N_Function_Call then
4036 Set_Ekind (Id, E_Constant);
4037 else
4038 Set_Ekind (Id, E_Variable);
4039 end if;
4040
4041 -- An object declared within a Ghost region is automatically
4042 -- Ghost (SPARK RM 6.9(2)).
4043
4044 if Ghost_Mode > None then
4045 Set_Is_Ghost_Entity (Id);
4046
4047 -- The Ghost policy in effect at the point of declaration
4048 -- and at the point of completion must match
4049 -- (SPARK RM 6.9(14)).
4050
4051 if Present (Prev_Entity)
4052 and then Is_Ghost_Entity (Prev_Entity)
4053 then
4054 Check_Ghost_Completion (Prev_Entity, Id);
4055 end if;
4056 end if;
4057
4058 Rewrite (N,
4059 Make_Object_Renaming_Declaration (Loc,
4060 Defining_Identifier => Id,
4061 Subtype_Mark => New_Occurrence_Of (T, Loc),
4062 Name => E));
4063
4064 Set_Renamed_Object (Id, E);
4065 Freeze_Before (N, T);
4066 Set_Is_Frozen (Id);
4067
4068 Ghost_Mode := Save_Ghost_Mode;
4069 return;
4070
4071 else
4072 -- Ensure that the generated subtype has a unique external name
4073 -- when the related object is public. This guarantees that the
4074 -- subtype and its bounds will not be affected by switches or
4075 -- pragmas that may offset the internal counter due to extra
4076 -- generated code.
4077
4078 if Is_Public (Id) then
4079 Related_Id := Id;
4080 else
4081 Related_Id := Empty;
4082 end if;
4083
4084 Expand_Subtype_From_Expr
4085 (N => N,
4086 Unc_Type => T,
4087 Subtype_Indic => Object_Definition (N),
4088 Exp => E,
4089 Related_Id => Related_Id);
4090
4091 Act_T := Find_Type_Of_Object (Object_Definition (N), N);
4092 end if;
4093
4094 Set_Is_Constr_Subt_For_U_Nominal (Act_T);
4095
4096 if Aliased_Present (N) then
4097 Set_Is_Constr_Subt_For_UN_Aliased (Act_T);
4098 end if;
4099
4100 Freeze_Before (N, Act_T);
4101 Freeze_Before (N, T);
4102 end if;
4103
4104 elsif Is_Array_Type (T)
4105 and then No_Initialization (N)
4106 and then (Nkind (Original_Node (E)) = N_Aggregate
4107 or else (Nkind (Original_Node (E)) = N_Qualified_Expression
4108 and then Nkind (Original_Node (Expression
4109 (Original_Node (E)))) = N_Aggregate))
4110 then
4111 if not Is_Entity_Name (Object_Definition (N)) then
4112 Act_T := Etype (E);
4113 Check_Compile_Time_Size (Act_T);
4114
4115 if Aliased_Present (N) then
4116 Set_Is_Constr_Subt_For_UN_Aliased (Act_T);
4117 end if;
4118 end if;
4119
4120 -- When the given object definition and the aggregate are specified
4121 -- independently, and their lengths might differ do a length check.
4122 -- This cannot happen if the aggregate is of the form (others =>...)
4123
4124 if not Is_Constrained (T) then
4125 null;
4126
4127 elsif Nkind (E) = N_Raise_Constraint_Error then
4128
4129 -- Aggregate is statically illegal. Place back in declaration
4130
4131 Set_Expression (N, E);
4132 Set_No_Initialization (N, False);
4133
4134 elsif T = Etype (E) then
4135 null;
4136
4137 elsif Nkind (E) = N_Aggregate
4138 and then Present (Component_Associations (E))
4139 and then Present (Choices (First (Component_Associations (E))))
4140 and then Nkind (First
4141 (Choices (First (Component_Associations (E))))) = N_Others_Choice
4142 then
4143 null;
4144
4145 else
4146 Apply_Length_Check (E, T);
4147 end if;
4148
4149 -- If the type is limited unconstrained with defaulted discriminants and
4150 -- there is no expression, then the object is constrained by the
4151 -- defaults, so it is worthwhile building the corresponding subtype.
4152
4153 elsif (Is_Limited_Record (T) or else Is_Concurrent_Type (T))
4154 and then not Is_Constrained (T)
4155 and then Has_Discriminants (T)
4156 then
4157 if No (E) then
4158 Act_T := Build_Default_Subtype (T, N);
4159 else
4160 -- Ada 2005: A limited object may be initialized by means of an
4161 -- aggregate. If the type has default discriminants it has an
4162 -- unconstrained nominal type, Its actual subtype will be obtained
4163 -- from the aggregate, and not from the default discriminants.
4164
4165 Act_T := Etype (E);
4166 end if;
4167
4168 Rewrite (Object_Definition (N), New_Occurrence_Of (Act_T, Loc));
4169
4170 elsif Nkind (E) = N_Function_Call
4171 and then Constant_Present (N)
4172 and then Has_Unconstrained_Elements (Etype (E))
4173 then
4174 -- The back-end has problems with constants of a discriminated type
4175 -- with defaults, if the initial value is a function call. We
4176 -- generate an intermediate temporary that will receive a reference
4177 -- to the result of the call. The initialization expression then
4178 -- becomes a dereference of that temporary.
4179
4180 Remove_Side_Effects (E);
4181
4182 -- If this is a constant declaration of an unconstrained type and
4183 -- the initialization is an aggregate, we can use the subtype of the
4184 -- aggregate for the declared entity because it is immutable.
4185
4186 elsif not Is_Constrained (T)
4187 and then Has_Discriminants (T)
4188 and then Constant_Present (N)
4189 and then not Has_Unchecked_Union (T)
4190 and then Nkind (E) = N_Aggregate
4191 then
4192 Act_T := Etype (E);
4193 end if;
4194
4195 -- Check No_Wide_Characters restriction
4196
4197 Check_Wide_Character_Restriction (T, Object_Definition (N));
4198
4199 -- Indicate this is not set in source. Certainly true for constants, and
4200 -- true for variables so far (will be reset for a variable if and when
4201 -- we encounter a modification in the source).
4202
4203 Set_Never_Set_In_Source (Id);
4204
4205 -- Now establish the proper kind and type of the object
4206
4207 if Constant_Present (N) then
4208 Set_Ekind (Id, E_Constant);
4209 Set_Is_True_Constant (Id);
4210
4211 else
4212 Set_Ekind (Id, E_Variable);
4213
4214 -- A variable is set as shared passive if it appears in a shared
4215 -- passive package, and is at the outer level. This is not done for
4216 -- entities generated during expansion, because those are always
4217 -- manipulated locally.
4218
4219 if Is_Shared_Passive (Current_Scope)
4220 and then Is_Library_Level_Entity (Id)
4221 and then Comes_From_Source (Id)
4222 then
4223 Set_Is_Shared_Passive (Id);
4224 Check_Shared_Var (Id, T, N);
4225 end if;
4226
4227 -- Set Has_Initial_Value if initializing expression present. Note
4228 -- that if there is no initializing expression, we leave the state
4229 -- of this flag unchanged (usually it will be False, but notably in
4230 -- the case of exception choice variables, it will already be true).
4231
4232 if Present (E) then
4233 Set_Has_Initial_Value (Id);
4234 end if;
4235 end if;
4236
4237 -- Initialize alignment and size and capture alignment setting
4238
4239 Init_Alignment (Id);
4240 Init_Esize (Id);
4241 Set_Optimize_Alignment_Flags (Id);
4242
4243 -- An object declared within a Ghost region is automatically Ghost
4244 -- (SPARK RM 6.9(2)).
4245
4246 if Ghost_Mode > None
4247 or else (Present (Prev_Entity) and then Is_Ghost_Entity (Prev_Entity))
4248 then
4249 Set_Is_Ghost_Entity (Id);
4250
4251 -- The Ghost policy in effect at the point of declaration and at the
4252 -- point of completion must match (SPARK RM 6.9(14)).
4253
4254 if Present (Prev_Entity) and then Is_Ghost_Entity (Prev_Entity) then
4255 Check_Ghost_Completion (Prev_Entity, Id);
4256 end if;
4257 end if;
4258
4259 -- Deal with aliased case
4260
4261 if Aliased_Present (N) then
4262 Set_Is_Aliased (Id);
4263
4264 -- If the object is aliased and the type is unconstrained with
4265 -- defaulted discriminants and there is no expression, then the
4266 -- object is constrained by the defaults, so it is worthwhile
4267 -- building the corresponding subtype.
4268
4269 -- Ada 2005 (AI-363): If the aliased object is discriminated and
4270 -- unconstrained, then only establish an actual subtype if the
4271 -- nominal subtype is indefinite. In definite cases the object is
4272 -- unconstrained in Ada 2005.
4273
4274 if No (E)
4275 and then Is_Record_Type (T)
4276 and then not Is_Constrained (T)
4277 and then Has_Discriminants (T)
4278 and then (Ada_Version < Ada_2005
4279 or else not Is_Definite_Subtype (T))
4280 then
4281 Set_Actual_Subtype (Id, Build_Default_Subtype (T, N));
4282 end if;
4283 end if;
4284
4285 -- Now we can set the type of the object
4286
4287 Set_Etype (Id, Act_T);
4288
4289 -- Non-constant object is marked to be treated as volatile if type is
4290 -- volatile and we clear the Current_Value setting that may have been
4291 -- set above. Doing so for constants isn't required and might interfere
4292 -- with possible uses of the object as a static expression in contexts
4293 -- incompatible with volatility (e.g. as a case-statement alternative).
4294
4295 if Ekind (Id) /= E_Constant and then Treat_As_Volatile (Etype (Id)) then
4296 Set_Treat_As_Volatile (Id);
4297 Set_Current_Value (Id, Empty);
4298 end if;
4299
4300 -- Deal with controlled types
4301
4302 if Has_Controlled_Component (Etype (Id))
4303 or else Is_Controlled (Etype (Id))
4304 then
4305 if not Is_Library_Level_Entity (Id) then
4306 Check_Restriction (No_Nested_Finalization, N);
4307 else
4308 Validate_Controlled_Object (Id);
4309 end if;
4310 end if;
4311
4312 if Has_Task (Etype (Id)) then
4313 Check_Restriction (No_Tasking, N);
4314
4315 -- Deal with counting max tasks
4316
4317 -- Nothing to do if inside a generic
4318
4319 if Inside_A_Generic then
4320 null;
4321
4322 -- If library level entity, then count tasks
4323
4324 elsif Is_Library_Level_Entity (Id) then
4325 Check_Restriction (Max_Tasks, N, Count_Tasks (Etype (Id)));
4326
4327 -- If not library level entity, then indicate we don't know max
4328 -- tasks and also check task hierarchy restriction and blocking
4329 -- operation (since starting a task is definitely blocking).
4330
4331 else
4332 Check_Restriction (Max_Tasks, N);
4333 Check_Restriction (No_Task_Hierarchy, N);
4334 Check_Potentially_Blocking_Operation (N);
4335 end if;
4336
4337 -- A rather specialized test. If we see two tasks being declared
4338 -- of the same type in the same object declaration, and the task
4339 -- has an entry with an address clause, we know that program error
4340 -- will be raised at run time since we can't have two tasks with
4341 -- entries at the same address.
4342
4343 if Is_Task_Type (Etype (Id)) and then More_Ids (N) then
4344 declare
4345 E : Entity_Id;
4346
4347 begin
4348 E := First_Entity (Etype (Id));
4349 while Present (E) loop
4350 if Ekind (E) = E_Entry
4351 and then Present (Get_Attribute_Definition_Clause
4352 (E, Attribute_Address))
4353 then
4354 Error_Msg_Warn := SPARK_Mode /= On;
4355 Error_Msg_N
4356 ("more than one task with same entry address<<", N);
4357 Error_Msg_N ("\Program_Error [<<", N);
4358 Insert_Action (N,
4359 Make_Raise_Program_Error (Loc,
4360 Reason => PE_Duplicated_Entry_Address));
4361 exit;
4362 end if;
4363
4364 Next_Entity (E);
4365 end loop;
4366 end;
4367 end if;
4368 end if;
4369
4370 -- Some simple constant-propagation: if the expression is a constant
4371 -- string initialized with a literal, share the literal. This avoids
4372 -- a run-time copy.
4373
4374 if Present (E)
4375 and then Is_Entity_Name (E)
4376 and then Ekind (Entity (E)) = E_Constant
4377 and then Base_Type (Etype (E)) = Standard_String
4378 then
4379 declare
4380 Val : constant Node_Id := Constant_Value (Entity (E));
4381 begin
4382 if Present (Val) and then Nkind (Val) = N_String_Literal then
4383 Rewrite (E, New_Copy (Val));
4384 end if;
4385 end;
4386 end if;
4387
4388 -- Another optimization: if the nominal subtype is unconstrained and
4389 -- the expression is a function call that returns an unconstrained
4390 -- type, rewrite the declaration as a renaming of the result of the
4391 -- call. The exceptions below are cases where the copy is expected,
4392 -- either by the back end (Aliased case) or by the semantics, as for
4393 -- initializing controlled types or copying tags for classwide types.
4394
4395 if Present (E)
4396 and then Nkind (E) = N_Explicit_Dereference
4397 and then Nkind (Original_Node (E)) = N_Function_Call
4398 and then not Is_Library_Level_Entity (Id)
4399 and then not Is_Constrained (Underlying_Type (T))
4400 and then not Is_Aliased (Id)
4401 and then not Is_Class_Wide_Type (T)
4402 and then not Is_Controlled_Active (T)
4403 and then not Has_Controlled_Component (Base_Type (T))
4404 and then Expander_Active
4405 then
4406 Rewrite (N,
4407 Make_Object_Renaming_Declaration (Loc,
4408 Defining_Identifier => Id,
4409 Access_Definition => Empty,
4410 Subtype_Mark => New_Occurrence_Of
4411 (Base_Type (Etype (Id)), Loc),
4412 Name => E));
4413
4414 Set_Renamed_Object (Id, E);
4415
4416 -- Force generation of debugging information for the constant and for
4417 -- the renamed function call.
4418
4419 Set_Debug_Info_Needed (Id);
4420 Set_Debug_Info_Needed (Entity (Prefix (E)));
4421 end if;
4422
4423 if Present (Prev_Entity)
4424 and then Is_Frozen (Prev_Entity)
4425 and then not Error_Posted (Id)
4426 then
4427 Error_Msg_N ("full constant declaration appears too late", N);
4428 end if;
4429
4430 Check_Eliminated (Id);
4431
4432 -- Deal with setting In_Private_Part flag if in private part
4433
4434 if Ekind (Scope (Id)) = E_Package
4435 and then In_Private_Part (Scope (Id))
4436 then
4437 Set_In_Private_Part (Id);
4438 end if;
4439
4440 <<Leave>>
4441 -- Initialize the refined state of a variable here because this is a
4442 -- common destination for legal and illegal object declarations.
4443
4444 if Ekind (Id) = E_Variable then
4445 Set_Encapsulating_State (Id, Empty);
4446 end if;
4447
4448 if Has_Aspects (N) then
4449 Analyze_Aspect_Specifications (N, Id);
4450 end if;
4451
4452 Analyze_Dimension (N);
4453
4454 -- Verify whether the object declaration introduces an illegal hidden
4455 -- state within a package subject to a null abstract state.
4456
4457 if Ekind (Id) = E_Variable then
4458 Check_No_Hidden_State (Id);
4459 end if;
4460
4461 Ghost_Mode := Save_Ghost_Mode;
4462 end Analyze_Object_Declaration;
4463
4464 ---------------------------
4465 -- Analyze_Others_Choice --
4466 ---------------------------
4467
4468 -- Nothing to do for the others choice node itself, the semantic analysis
4469 -- of the others choice will occur as part of the processing of the parent
4470
4471 procedure Analyze_Others_Choice (N : Node_Id) is
4472 pragma Warnings (Off, N);
4473 begin
4474 null;
4475 end Analyze_Others_Choice;
4476
4477 -------------------------------------------
4478 -- Analyze_Private_Extension_Declaration --
4479 -------------------------------------------
4480
4481 procedure Analyze_Private_Extension_Declaration (N : Node_Id) is
4482 Indic : constant Node_Id := Subtype_Indication (N);
4483 T : constant Entity_Id := Defining_Identifier (N);
4484 Iface : Entity_Id;
4485 Iface_Elmt : Elmt_Id;
4486 Parent_Base : Entity_Id;
4487 Parent_Type : Entity_Id;
4488
4489 begin
4490 -- Ada 2005 (AI-251): Decorate all names in list of ancestor interfaces
4491
4492 if Is_Non_Empty_List (Interface_List (N)) then
4493 declare
4494 Intf : Node_Id;
4495 T : Entity_Id;
4496
4497 begin
4498 Intf := First (Interface_List (N));
4499 while Present (Intf) loop
4500 T := Find_Type_Of_Subtype_Indic (Intf);
4501
4502 Diagnose_Interface (Intf, T);
4503 Next (Intf);
4504 end loop;
4505 end;
4506 end if;
4507
4508 Generate_Definition (T);
4509
4510 -- For other than Ada 2012, just enter the name in the current scope
4511
4512 if Ada_Version < Ada_2012 then
4513 Enter_Name (T);
4514
4515 -- Ada 2012 (AI05-0162): Enter the name in the current scope handling
4516 -- case of private type that completes an incomplete type.
4517
4518 else
4519 declare
4520 Prev : Entity_Id;
4521
4522 begin
4523 Prev := Find_Type_Name (N);
4524
4525 pragma Assert (Prev = T
4526 or else (Ekind (Prev) = E_Incomplete_Type
4527 and then Present (Full_View (Prev))
4528 and then Full_View (Prev) = T));
4529 end;
4530 end if;
4531
4532 Parent_Type := Find_Type_Of_Subtype_Indic (Indic);
4533 Parent_Base := Base_Type (Parent_Type);
4534
4535 if Parent_Type = Any_Type or else Etype (Parent_Type) = Any_Type then
4536 Set_Ekind (T, Ekind (Parent_Type));
4537 Set_Etype (T, Any_Type);
4538 goto Leave;
4539
4540 elsif not Is_Tagged_Type (Parent_Type) then
4541 Error_Msg_N
4542 ("parent of type extension must be a tagged type ", Indic);
4543 goto Leave;
4544
4545 elsif Ekind_In (Parent_Type, E_Void, E_Incomplete_Type) then
4546 Error_Msg_N ("premature derivation of incomplete type", Indic);
4547 goto Leave;
4548
4549 elsif Is_Concurrent_Type (Parent_Type) then
4550 Error_Msg_N
4551 ("parent type of a private extension cannot be a synchronized "
4552 & "tagged type (RM 3.9.1 (3/1))", N);
4553
4554 Set_Etype (T, Any_Type);
4555 Set_Ekind (T, E_Limited_Private_Type);
4556 Set_Private_Dependents (T, New_Elmt_List);
4557 Set_Error_Posted (T);
4558 goto Leave;
4559 end if;
4560
4561 -- Perhaps the parent type should be changed to the class-wide type's
4562 -- specific type in this case to prevent cascading errors ???
4563
4564 if Is_Class_Wide_Type (Parent_Type) then
4565 Error_Msg_N
4566 ("parent of type extension must not be a class-wide type", Indic);
4567 goto Leave;
4568 end if;
4569
4570 if (not Is_Package_Or_Generic_Package (Current_Scope)
4571 and then Nkind (Parent (N)) /= N_Generic_Subprogram_Declaration)
4572 or else In_Private_Part (Current_Scope)
4573 then
4574 Error_Msg_N ("invalid context for private extension", N);
4575 end if;
4576
4577 -- Set common attributes
4578
4579 Set_Is_Pure (T, Is_Pure (Current_Scope));
4580 Set_Scope (T, Current_Scope);
4581 Set_Ekind (T, E_Record_Type_With_Private);
4582 Init_Size_Align (T);
4583 Set_Default_SSO (T);
4584
4585 Set_Etype (T, Parent_Base);
4586 Propagate_Concurrent_Flags (T, Parent_Base);
4587
4588 Set_Convention (T, Convention (Parent_Type));
4589 Set_First_Rep_Item (T, First_Rep_Item (Parent_Type));
4590 Set_Is_First_Subtype (T);
4591 Make_Class_Wide_Type (T);
4592
4593 if Unknown_Discriminants_Present (N) then
4594 Set_Discriminant_Constraint (T, No_Elist);
4595 end if;
4596
4597 Build_Derived_Record_Type (N, Parent_Type, T);
4598
4599 -- A private extension inherits any class-wide invariants coming from a
4600 -- parent type or an interface. Note that the invariant procedure of the
4601 -- parent type should not be inherited because the private extension may
4602 -- define invariants of its own.
4603
4604 if Has_Inheritable_Invariants (Parent_Type) then
4605 Set_Has_Inherited_Invariants (T);
4606
4607 elsif Present (Interfaces (T)) then
4608 Iface_Elmt := First_Elmt (Interfaces (T));
4609 while Present (Iface_Elmt) loop
4610 Iface := Node (Iface_Elmt);
4611
4612 if Has_Inheritable_Invariants (Iface) then
4613 Set_Has_Inherited_Invariants (T);
4614 exit;
4615 end if;
4616
4617 Next_Elmt (Iface_Elmt);
4618 end loop;
4619 end if;
4620
4621 -- Ada 2005 (AI-443): Synchronized private extension or a rewritten
4622 -- synchronized formal derived type.
4623
4624 if Ada_Version >= Ada_2005 and then Synchronized_Present (N) then
4625 Set_Is_Limited_Record (T);
4626
4627 -- Formal derived type case
4628
4629 if Is_Generic_Type (T) then
4630
4631 -- The parent must be a tagged limited type or a synchronized
4632 -- interface.
4633
4634 if (not Is_Tagged_Type (Parent_Type)
4635 or else not Is_Limited_Type (Parent_Type))
4636 and then
4637 (not Is_Interface (Parent_Type)
4638 or else not Is_Synchronized_Interface (Parent_Type))
4639 then
4640 Error_Msg_NE
4641 ("parent type of & must be tagged limited or synchronized",
4642 N, T);
4643 end if;
4644
4645 -- The progenitors (if any) must be limited or synchronized
4646 -- interfaces.
4647
4648 if Present (Interfaces (T)) then
4649 Iface_Elmt := First_Elmt (Interfaces (T));
4650 while Present (Iface_Elmt) loop
4651 Iface := Node (Iface_Elmt);
4652
4653 if not Is_Limited_Interface (Iface)
4654 and then not Is_Synchronized_Interface (Iface)
4655 then
4656 Error_Msg_NE
4657 ("progenitor & must be limited or synchronized",
4658 N, Iface);
4659 end if;
4660
4661 Next_Elmt (Iface_Elmt);
4662 end loop;
4663 end if;
4664
4665 -- Regular derived extension, the parent must be a limited or
4666 -- synchronized interface.
4667
4668 else
4669 if not Is_Interface (Parent_Type)
4670 or else (not Is_Limited_Interface (Parent_Type)
4671 and then not Is_Synchronized_Interface (Parent_Type))
4672 then
4673 Error_Msg_NE
4674 ("parent type of & must be limited interface", N, T);
4675 end if;
4676 end if;
4677
4678 -- A consequence of 3.9.4 (6/2) and 7.3 (7.2/2) is that a private
4679 -- extension with a synchronized parent must be explicitly declared
4680 -- synchronized, because the full view will be a synchronized type.
4681 -- This must be checked before the check for limited types below,
4682 -- to ensure that types declared limited are not allowed to extend
4683 -- synchronized interfaces.
4684
4685 elsif Is_Interface (Parent_Type)
4686 and then Is_Synchronized_Interface (Parent_Type)
4687 and then not Synchronized_Present (N)
4688 then
4689 Error_Msg_NE
4690 ("private extension of& must be explicitly synchronized",
4691 N, Parent_Type);
4692
4693 elsif Limited_Present (N) then
4694 Set_Is_Limited_Record (T);
4695
4696 if not Is_Limited_Type (Parent_Type)
4697 and then
4698 (not Is_Interface (Parent_Type)
4699 or else not Is_Limited_Interface (Parent_Type))
4700 then
4701 Error_Msg_NE ("parent type& of limited extension must be limited",
4702 N, Parent_Type);
4703 end if;
4704 end if;
4705
4706 <<Leave>>
4707 if Has_Aspects (N) then
4708 Analyze_Aspect_Specifications (N, T);
4709 end if;
4710 end Analyze_Private_Extension_Declaration;
4711
4712 ---------------------------------
4713 -- Analyze_Subtype_Declaration --
4714 ---------------------------------
4715
4716 procedure Analyze_Subtype_Declaration
4717 (N : Node_Id;
4718 Skip : Boolean := False)
4719 is
4720 Id : constant Entity_Id := Defining_Identifier (N);
4721 R_Checks : Check_Result;
4722 T : Entity_Id;
4723
4724 begin
4725 Generate_Definition (Id);
4726 Set_Is_Pure (Id, Is_Pure (Current_Scope));
4727 Init_Size_Align (Id);
4728
4729 -- The following guard condition on Enter_Name is to handle cases where
4730 -- the defining identifier has already been entered into the scope but
4731 -- the declaration as a whole needs to be analyzed.
4732
4733 -- This case in particular happens for derived enumeration types. The
4734 -- derived enumeration type is processed as an inserted enumeration type
4735 -- declaration followed by a rewritten subtype declaration. The defining
4736 -- identifier, however, is entered into the name scope very early in the
4737 -- processing of the original type declaration and therefore needs to be
4738 -- avoided here, when the created subtype declaration is analyzed. (See
4739 -- Build_Derived_Types)
4740
4741 -- This also happens when the full view of a private type is derived
4742 -- type with constraints. In this case the entity has been introduced
4743 -- in the private declaration.
4744
4745 -- Finally this happens in some complex cases when validity checks are
4746 -- enabled, where the same subtype declaration may be analyzed twice.
4747 -- This can happen if the subtype is created by the pre-analysis of
4748 -- an attribute tht gives the range of a loop statement, and the loop
4749 -- itself appears within an if_statement that will be rewritten during
4750 -- expansion.
4751
4752 if Skip
4753 or else (Present (Etype (Id))
4754 and then (Is_Private_Type (Etype (Id))
4755 or else Is_Task_Type (Etype (Id))
4756 or else Is_Rewrite_Substitution (N)))
4757 then
4758 null;
4759
4760 elsif Current_Entity (Id) = Id then
4761 null;
4762
4763 else
4764 Enter_Name (Id);
4765 end if;
4766
4767 T := Process_Subtype (Subtype_Indication (N), N, Id, 'P');
4768
4769 -- Class-wide equivalent types of records with unknown discriminants
4770 -- involve the generation of an itype which serves as the private view
4771 -- of a constrained record subtype. In such cases the base type of the
4772 -- current subtype we are processing is the private itype. Use the full
4773 -- of the private itype when decorating various attributes.
4774
4775 if Is_Itype (T)
4776 and then Is_Private_Type (T)
4777 and then Present (Full_View (T))
4778 then
4779 T := Full_View (T);
4780 end if;
4781
4782 -- Inherit common attributes
4783
4784 Set_Is_Volatile (Id, Is_Volatile (T));
4785 Set_Treat_As_Volatile (Id, Treat_As_Volatile (T));
4786 Set_Is_Generic_Type (Id, Is_Generic_Type (Base_Type (T)));
4787 Set_Convention (Id, Convention (T));
4788
4789 -- If ancestor has predicates then so does the subtype, and in addition
4790 -- we must delay the freeze to properly arrange predicate inheritance.
4791
4792 -- The Ancestor_Type test is really unpleasant, there seem to be cases
4793 -- in which T = ID, so the above tests and assignments do nothing???
4794
4795 if Has_Predicates (T)
4796 or else (Present (Ancestor_Subtype (T))
4797 and then Has_Predicates (Ancestor_Subtype (T)))
4798 then
4799 Set_Has_Predicates (Id);
4800 Set_Has_Delayed_Freeze (Id);
4801 end if;
4802
4803 -- Subtype of Boolean cannot have a constraint in SPARK
4804
4805 if Is_Boolean_Type (T)
4806 and then Nkind (Subtype_Indication (N)) = N_Subtype_Indication
4807 then
4808 Check_SPARK_05_Restriction
4809 ("subtype of Boolean cannot have constraint", N);
4810 end if;
4811
4812 if Nkind (Subtype_Indication (N)) = N_Subtype_Indication then
4813 declare
4814 Cstr : constant Node_Id := Constraint (Subtype_Indication (N));
4815 One_Cstr : Node_Id;
4816 Low : Node_Id;
4817 High : Node_Id;
4818
4819 begin
4820 if Nkind (Cstr) = N_Index_Or_Discriminant_Constraint then
4821 One_Cstr := First (Constraints (Cstr));
4822 while Present (One_Cstr) loop
4823
4824 -- Index or discriminant constraint in SPARK must be a
4825 -- subtype mark.
4826
4827 if not
4828 Nkind_In (One_Cstr, N_Identifier, N_Expanded_Name)
4829 then
4830 Check_SPARK_05_Restriction
4831 ("subtype mark required", One_Cstr);
4832
4833 -- String subtype must have a lower bound of 1 in SPARK.
4834 -- Note that we do not need to test for the non-static case
4835 -- here, since that was already taken care of in
4836 -- Process_Range_Expr_In_Decl.
4837
4838 elsif Base_Type (T) = Standard_String then
4839 Get_Index_Bounds (One_Cstr, Low, High);
4840
4841 if Is_OK_Static_Expression (Low)
4842 and then Expr_Value (Low) /= 1
4843 then
4844 Check_SPARK_05_Restriction
4845 ("String subtype must have lower bound of 1", N);
4846 end if;
4847 end if;
4848
4849 Next (One_Cstr);
4850 end loop;
4851 end if;
4852 end;
4853 end if;
4854
4855 -- In the case where there is no constraint given in the subtype
4856 -- indication, Process_Subtype just returns the Subtype_Mark, so its
4857 -- semantic attributes must be established here.
4858
4859 if Nkind (Subtype_Indication (N)) /= N_Subtype_Indication then
4860 Set_Etype (Id, Base_Type (T));
4861
4862 -- Subtype of unconstrained array without constraint is not allowed
4863 -- in SPARK.
4864
4865 if Is_Array_Type (T) and then not Is_Constrained (T) then
4866 Check_SPARK_05_Restriction
4867 ("subtype of unconstrained array must have constraint", N);
4868 end if;
4869
4870 case Ekind (T) is
4871 when Array_Kind =>
4872 Set_Ekind (Id, E_Array_Subtype);
4873 Copy_Array_Subtype_Attributes (Id, T);
4874
4875 when Decimal_Fixed_Point_Kind =>
4876 Set_Ekind (Id, E_Decimal_Fixed_Point_Subtype);
4877 Set_Digits_Value (Id, Digits_Value (T));
4878 Set_Delta_Value (Id, Delta_Value (T));
4879 Set_Scale_Value (Id, Scale_Value (T));
4880 Set_Small_Value (Id, Small_Value (T));
4881 Set_Scalar_Range (Id, Scalar_Range (T));
4882 Set_Machine_Radix_10 (Id, Machine_Radix_10 (T));
4883 Set_Is_Constrained (Id, Is_Constrained (T));
4884 Set_Is_Known_Valid (Id, Is_Known_Valid (T));
4885 Set_RM_Size (Id, RM_Size (T));
4886
4887 when Enumeration_Kind =>
4888 Set_Ekind (Id, E_Enumeration_Subtype);
4889 Set_First_Literal (Id, First_Literal (Base_Type (T)));
4890 Set_Scalar_Range (Id, Scalar_Range (T));
4891 Set_Is_Character_Type (Id, Is_Character_Type (T));
4892 Set_Is_Constrained (Id, Is_Constrained (T));
4893 Set_Is_Known_Valid (Id, Is_Known_Valid (T));
4894 Set_RM_Size (Id, RM_Size (T));
4895 Inherit_Predicate_Flags (Id, T);
4896
4897 when Ordinary_Fixed_Point_Kind =>
4898 Set_Ekind (Id, E_Ordinary_Fixed_Point_Subtype);
4899 Set_Scalar_Range (Id, Scalar_Range (T));
4900 Set_Small_Value (Id, Small_Value (T));
4901 Set_Delta_Value (Id, Delta_Value (T));
4902 Set_Is_Constrained (Id, Is_Constrained (T));
4903 Set_Is_Known_Valid (Id, Is_Known_Valid (T));
4904 Set_RM_Size (Id, RM_Size (T));
4905
4906 when Float_Kind =>
4907 Set_Ekind (Id, E_Floating_Point_Subtype);
4908 Set_Scalar_Range (Id, Scalar_Range (T));
4909 Set_Digits_Value (Id, Digits_Value (T));
4910 Set_Is_Constrained (Id, Is_Constrained (T));
4911
4912 -- If the floating point type has dimensions, these will be
4913 -- inherited subsequently when Analyze_Dimensions is called.
4914
4915 when Signed_Integer_Kind =>
4916 Set_Ekind (Id, E_Signed_Integer_Subtype);
4917 Set_Scalar_Range (Id, Scalar_Range (T));
4918 Set_Is_Constrained (Id, Is_Constrained (T));
4919 Set_Is_Known_Valid (Id, Is_Known_Valid (T));
4920 Set_RM_Size (Id, RM_Size (T));
4921 Inherit_Predicate_Flags (Id, T);
4922
4923 when Modular_Integer_Kind =>
4924 Set_Ekind (Id, E_Modular_Integer_Subtype);
4925 Set_Scalar_Range (Id, Scalar_Range (T));
4926 Set_Is_Constrained (Id, Is_Constrained (T));
4927 Set_Is_Known_Valid (Id, Is_Known_Valid (T));
4928 Set_RM_Size (Id, RM_Size (T));
4929 Inherit_Predicate_Flags (Id, T);
4930
4931 when Class_Wide_Kind =>
4932 Set_Ekind (Id, E_Class_Wide_Subtype);
4933 Set_Class_Wide_Type (Id, Class_Wide_Type (T));
4934 Set_Cloned_Subtype (Id, T);
4935 Set_Is_Tagged_Type (Id, True);
4936 Set_Has_Unknown_Discriminants
4937 (Id, True);
4938 Set_No_Tagged_Streams_Pragma
4939 (Id, No_Tagged_Streams_Pragma (T));
4940
4941 if Ekind (T) = E_Class_Wide_Subtype then
4942 Set_Equivalent_Type (Id, Equivalent_Type (T));
4943 end if;
4944
4945 when E_Record_Type | E_Record_Subtype =>
4946 Set_Ekind (Id, E_Record_Subtype);
4947
4948 if Ekind (T) = E_Record_Subtype
4949 and then Present (Cloned_Subtype (T))
4950 then
4951 Set_Cloned_Subtype (Id, Cloned_Subtype (T));
4952 else
4953 Set_Cloned_Subtype (Id, T);
4954 end if;
4955
4956 Set_First_Entity (Id, First_Entity (T));
4957 Set_Last_Entity (Id, Last_Entity (T));
4958 Set_Has_Discriminants (Id, Has_Discriminants (T));
4959 Set_Is_Constrained (Id, Is_Constrained (T));
4960 Set_Is_Limited_Record (Id, Is_Limited_Record (T));
4961 Set_Has_Implicit_Dereference
4962 (Id, Has_Implicit_Dereference (T));
4963 Set_Has_Unknown_Discriminants
4964 (Id, Has_Unknown_Discriminants (T));
4965
4966 if Has_Discriminants (T) then
4967 Set_Discriminant_Constraint
4968 (Id, Discriminant_Constraint (T));
4969 Set_Stored_Constraint_From_Discriminant_Constraint (Id);
4970
4971 elsif Has_Unknown_Discriminants (Id) then
4972 Set_Discriminant_Constraint (Id, No_Elist);
4973 end if;
4974
4975 if Is_Tagged_Type (T) then
4976 Set_Is_Tagged_Type (Id, True);
4977 Set_No_Tagged_Streams_Pragma
4978 (Id, No_Tagged_Streams_Pragma (T));
4979 Set_Is_Abstract_Type (Id, Is_Abstract_Type (T));
4980 Set_Direct_Primitive_Operations
4981 (Id, Direct_Primitive_Operations (T));
4982 Set_Class_Wide_Type (Id, Class_Wide_Type (T));
4983
4984 if Is_Interface (T) then
4985 Set_Is_Interface (Id);
4986 Set_Is_Limited_Interface (Id, Is_Limited_Interface (T));
4987 end if;
4988 end if;
4989
4990 when Private_Kind =>
4991 Set_Ekind (Id, Subtype_Kind (Ekind (T)));
4992 Set_Has_Discriminants (Id, Has_Discriminants (T));
4993 Set_Is_Constrained (Id, Is_Constrained (T));
4994 Set_First_Entity (Id, First_Entity (T));
4995 Set_Last_Entity (Id, Last_Entity (T));
4996 Set_Private_Dependents (Id, New_Elmt_List);
4997 Set_Is_Limited_Record (Id, Is_Limited_Record (T));
4998 Set_Has_Implicit_Dereference
4999 (Id, Has_Implicit_Dereference (T));
5000 Set_Has_Unknown_Discriminants
5001 (Id, Has_Unknown_Discriminants (T));
5002 Set_Known_To_Have_Preelab_Init
5003 (Id, Known_To_Have_Preelab_Init (T));
5004
5005 if Is_Tagged_Type (T) then
5006 Set_Is_Tagged_Type (Id);
5007 Set_No_Tagged_Streams_Pragma (Id,
5008 No_Tagged_Streams_Pragma (T));
5009 Set_Is_Abstract_Type (Id, Is_Abstract_Type (T));
5010 Set_Class_Wide_Type (Id, Class_Wide_Type (T));
5011 Set_Direct_Primitive_Operations (Id,
5012 Direct_Primitive_Operations (T));
5013 end if;
5014
5015 -- In general the attributes of the subtype of a private type
5016 -- are the attributes of the partial view of parent. However,
5017 -- the full view may be a discriminated type, and the subtype
5018 -- must share the discriminant constraint to generate correct
5019 -- calls to initialization procedures.
5020
5021 if Has_Discriminants (T) then
5022 Set_Discriminant_Constraint
5023 (Id, Discriminant_Constraint (T));
5024 Set_Stored_Constraint_From_Discriminant_Constraint (Id);
5025
5026 elsif Present (Full_View (T))
5027 and then Has_Discriminants (Full_View (T))
5028 then
5029 Set_Discriminant_Constraint
5030 (Id, Discriminant_Constraint (Full_View (T)));
5031 Set_Stored_Constraint_From_Discriminant_Constraint (Id);
5032
5033 -- This would seem semantically correct, but apparently
5034 -- generates spurious errors about missing components ???
5035
5036 -- Set_Has_Discriminants (Id);
5037 end if;
5038
5039 Prepare_Private_Subtype_Completion (Id, N);
5040
5041 -- If this is the subtype of a constrained private type with
5042 -- discriminants that has got a full view and we also have
5043 -- built a completion just above, show that the completion
5044 -- is a clone of the full view to the back-end.
5045
5046 if Has_Discriminants (T)
5047 and then not Has_Unknown_Discriminants (T)
5048 and then not Is_Empty_Elmt_List (Discriminant_Constraint (T))
5049 and then Present (Full_View (T))
5050 and then Present (Full_View (Id))
5051 then
5052 Set_Cloned_Subtype (Full_View (Id), Full_View (T));
5053 end if;
5054
5055 when Access_Kind =>
5056 Set_Ekind (Id, E_Access_Subtype);
5057 Set_Is_Constrained (Id, Is_Constrained (T));
5058 Set_Is_Access_Constant
5059 (Id, Is_Access_Constant (T));
5060 Set_Directly_Designated_Type
5061 (Id, Designated_Type (T));
5062 Set_Can_Never_Be_Null (Id, Can_Never_Be_Null (T));
5063
5064 -- A Pure library_item must not contain the declaration of a
5065 -- named access type, except within a subprogram, generic
5066 -- subprogram, task unit, or protected unit, or if it has
5067 -- a specified Storage_Size of zero (RM05-10.2.1(15.4-15.5)).
5068
5069 if Comes_From_Source (Id)
5070 and then In_Pure_Unit
5071 and then not In_Subprogram_Task_Protected_Unit
5072 and then not No_Pool_Assigned (Id)
5073 then
5074 Error_Msg_N
5075 ("named access types not allowed in pure unit", N);
5076 end if;
5077
5078 when Concurrent_Kind =>
5079 Set_Ekind (Id, Subtype_Kind (Ekind (T)));
5080 Set_Corresponding_Record_Type (Id,
5081 Corresponding_Record_Type (T));
5082 Set_First_Entity (Id, First_Entity (T));
5083 Set_First_Private_Entity (Id, First_Private_Entity (T));
5084 Set_Has_Discriminants (Id, Has_Discriminants (T));
5085 Set_Is_Constrained (Id, Is_Constrained (T));
5086 Set_Is_Tagged_Type (Id, Is_Tagged_Type (T));
5087 Set_Last_Entity (Id, Last_Entity (T));
5088
5089 if Is_Tagged_Type (T) then
5090 Set_No_Tagged_Streams_Pragma
5091 (Id, No_Tagged_Streams_Pragma (T));
5092 end if;
5093
5094 if Has_Discriminants (T) then
5095 Set_Discriminant_Constraint
5096 (Id, Discriminant_Constraint (T));
5097 Set_Stored_Constraint_From_Discriminant_Constraint (Id);
5098 end if;
5099
5100 when Incomplete_Kind =>
5101 if Ada_Version >= Ada_2005 then
5102
5103 -- In Ada 2005 an incomplete type can be explicitly tagged:
5104 -- propagate indication. Note that we also have to include
5105 -- subtypes for Ada 2012 extended use of incomplete types.
5106
5107 Set_Ekind (Id, E_Incomplete_Subtype);
5108 Set_Is_Tagged_Type (Id, Is_Tagged_Type (T));
5109 Set_Private_Dependents (Id, New_Elmt_List);
5110
5111 if Is_Tagged_Type (Id) then
5112 Set_No_Tagged_Streams_Pragma
5113 (Id, No_Tagged_Streams_Pragma (T));
5114 Set_Direct_Primitive_Operations (Id, New_Elmt_List);
5115 end if;
5116
5117 -- Ada 2005 (AI-412): Decorate an incomplete subtype of an
5118 -- incomplete type visible through a limited with clause.
5119
5120 if From_Limited_With (T)
5121 and then Present (Non_Limited_View (T))
5122 then
5123 Set_From_Limited_With (Id);
5124 Set_Non_Limited_View (Id, Non_Limited_View (T));
5125
5126 -- Ada 2005 (AI-412): Add the regular incomplete subtype
5127 -- to the private dependents of the original incomplete
5128 -- type for future transformation.
5129
5130 else
5131 Append_Elmt (Id, Private_Dependents (T));
5132 end if;
5133
5134 -- If the subtype name denotes an incomplete type an error
5135 -- was already reported by Process_Subtype.
5136
5137 else
5138 Set_Etype (Id, Any_Type);
5139 end if;
5140
5141 when others =>
5142 raise Program_Error;
5143 end case;
5144 end if;
5145
5146 if Etype (Id) = Any_Type then
5147 goto Leave;
5148 end if;
5149
5150 -- Some common processing on all types
5151
5152 Set_Size_Info (Id, T);
5153 Set_First_Rep_Item (Id, First_Rep_Item (T));
5154
5155 -- If the parent type is a generic actual, so is the subtype. This may
5156 -- happen in a nested instance. Why Comes_From_Source test???
5157
5158 if not Comes_From_Source (N) then
5159 Set_Is_Generic_Actual_Type (Id, Is_Generic_Actual_Type (T));
5160 end if;
5161
5162 -- If this is a subtype declaration for an actual in an instance,
5163 -- inherit static and dynamic predicates if any.
5164
5165 -- If declaration has no aspect specifications, inherit predicate
5166 -- info as well. Unclear how to handle the case of both specified
5167 -- and inherited predicates ??? Other inherited aspects, such as
5168 -- invariants, should be OK, but the combination with later pragmas
5169 -- may also require special merging.
5170
5171 if Has_Predicates (T)
5172 and then Present (Predicate_Function (T))
5173 and then
5174 ((In_Instance and then not Comes_From_Source (N))
5175 or else No (Aspect_Specifications (N)))
5176 then
5177 Set_Subprograms_For_Type (Id, Subprograms_For_Type (T));
5178
5179 if Has_Static_Predicate (T) then
5180 Set_Has_Static_Predicate (Id);
5181 Set_Static_Discrete_Predicate (Id, Static_Discrete_Predicate (T));
5182 end if;
5183 end if;
5184
5185 -- Propagate invariant-related attributes from the base type to the
5186 -- subtype.
5187
5188 Propagate_Invariant_Attributes (Id, From_Typ => Base_Type (T));
5189
5190 -- Remaining processing depends on characteristics of base type
5191
5192 T := Etype (Id);
5193
5194 Set_Is_Immediately_Visible (Id, True);
5195 Set_Depends_On_Private (Id, Has_Private_Component (T));
5196 Set_Is_Descendant_Of_Address (Id, Is_Descendant_Of_Address (T));
5197
5198 if Is_Interface (T) then
5199 Set_Is_Interface (Id);
5200 end if;
5201
5202 if Present (Generic_Parent_Type (N))
5203 and then
5204 (Nkind (Parent (Generic_Parent_Type (N))) /=
5205 N_Formal_Type_Declaration
5206 or else Nkind (Formal_Type_Definition
5207 (Parent (Generic_Parent_Type (N)))) /=
5208 N_Formal_Private_Type_Definition)
5209 then
5210 if Is_Tagged_Type (Id) then
5211
5212 -- If this is a generic actual subtype for a synchronized type,
5213 -- the primitive operations are those of the corresponding record
5214 -- for which there is a separate subtype declaration.
5215
5216 if Is_Concurrent_Type (Id) then
5217 null;
5218 elsif Is_Class_Wide_Type (Id) then
5219 Derive_Subprograms (Generic_Parent_Type (N), Id, Etype (T));
5220 else
5221 Derive_Subprograms (Generic_Parent_Type (N), Id, T);
5222 end if;
5223
5224 elsif Scope (Etype (Id)) /= Standard_Standard then
5225 Derive_Subprograms (Generic_Parent_Type (N), Id);
5226 end if;
5227 end if;
5228
5229 if Is_Private_Type (T) and then Present (Full_View (T)) then
5230 Conditional_Delay (Id, Full_View (T));
5231
5232 -- The subtypes of components or subcomponents of protected types
5233 -- do not need freeze nodes, which would otherwise appear in the
5234 -- wrong scope (before the freeze node for the protected type). The
5235 -- proper subtypes are those of the subcomponents of the corresponding
5236 -- record.
5237
5238 elsif Ekind (Scope (Id)) /= E_Protected_Type
5239 and then Present (Scope (Scope (Id))) -- error defense
5240 and then Ekind (Scope (Scope (Id))) /= E_Protected_Type
5241 then
5242 Conditional_Delay (Id, T);
5243 end if;
5244
5245 -- Check that Constraint_Error is raised for a scalar subtype indication
5246 -- when the lower or upper bound of a non-null range lies outside the
5247 -- range of the type mark.
5248
5249 if Nkind (Subtype_Indication (N)) = N_Subtype_Indication then
5250 if Is_Scalar_Type (Etype (Id))
5251 and then Scalar_Range (Id) /=
5252 Scalar_Range
5253 (Etype (Subtype_Mark (Subtype_Indication (N))))
5254 then
5255 Apply_Range_Check
5256 (Scalar_Range (Id),
5257 Etype (Subtype_Mark (Subtype_Indication (N))));
5258
5259 -- In the array case, check compatibility for each index
5260
5261 elsif Is_Array_Type (Etype (Id)) and then Present (First_Index (Id))
5262 then
5263 -- This really should be a subprogram that finds the indications
5264 -- to check???
5265
5266 declare
5267 Subt_Index : Node_Id := First_Index (Id);
5268 Target_Index : Node_Id :=
5269 First_Index (Etype
5270 (Subtype_Mark (Subtype_Indication (N))));
5271 Has_Dyn_Chk : Boolean := Has_Dynamic_Range_Check (N);
5272
5273 begin
5274 while Present (Subt_Index) loop
5275 if ((Nkind (Subt_Index) = N_Identifier
5276 and then Ekind (Entity (Subt_Index)) in Scalar_Kind)
5277 or else Nkind (Subt_Index) = N_Subtype_Indication)
5278 and then
5279 Nkind (Scalar_Range (Etype (Subt_Index))) = N_Range
5280 then
5281 declare
5282 Target_Typ : constant Entity_Id :=
5283 Etype (Target_Index);
5284 begin
5285 R_Checks :=
5286 Get_Range_Checks
5287 (Scalar_Range (Etype (Subt_Index)),
5288 Target_Typ,
5289 Etype (Subt_Index),
5290 Defining_Identifier (N));
5291
5292 -- Reset Has_Dynamic_Range_Check on the subtype to
5293 -- prevent elision of the index check due to a dynamic
5294 -- check generated for a preceding index (needed since
5295 -- Insert_Range_Checks tries to avoid generating
5296 -- redundant checks on a given declaration).
5297
5298 Set_Has_Dynamic_Range_Check (N, False);
5299
5300 Insert_Range_Checks
5301 (R_Checks,
5302 N,
5303 Target_Typ,
5304 Sloc (Defining_Identifier (N)));
5305
5306 -- Record whether this index involved a dynamic check
5307
5308 Has_Dyn_Chk :=
5309 Has_Dyn_Chk or else Has_Dynamic_Range_Check (N);
5310 end;
5311 end if;
5312
5313 Next_Index (Subt_Index);
5314 Next_Index (Target_Index);
5315 end loop;
5316
5317 -- Finally, mark whether the subtype involves dynamic checks
5318
5319 Set_Has_Dynamic_Range_Check (N, Has_Dyn_Chk);
5320 end;
5321 end if;
5322 end if;
5323
5324 -- Make sure that generic actual types are properly frozen. The subtype
5325 -- is marked as a generic actual type when the enclosing instance is
5326 -- analyzed, so here we identify the subtype from the tree structure.
5327
5328 if Expander_Active
5329 and then Is_Generic_Actual_Type (Id)
5330 and then In_Instance
5331 and then not Comes_From_Source (N)
5332 and then Nkind (Subtype_Indication (N)) /= N_Subtype_Indication
5333 and then Is_Frozen (T)
5334 then
5335 Freeze_Before (N, Id);
5336 end if;
5337
5338 Set_Optimize_Alignment_Flags (Id);
5339 Check_Eliminated (Id);
5340
5341 <<Leave>>
5342 if Has_Aspects (N) then
5343 Analyze_Aspect_Specifications (N, Id);
5344 end if;
5345
5346 Analyze_Dimension (N);
5347
5348 -- Check No_Dynamic_Sized_Objects restriction, which disallows subtype
5349 -- indications on composite types where the constraints are dynamic.
5350 -- Note that object declarations and aggregates generate implicit
5351 -- subtype declarations, which this covers. One special case is that the
5352 -- implicitly generated "=" for discriminated types includes an
5353 -- offending subtype declaration, which is harmless, so we ignore it
5354 -- here.
5355
5356 if Nkind (Subtype_Indication (N)) = N_Subtype_Indication then
5357 declare
5358 Cstr : constant Node_Id := Constraint (Subtype_Indication (N));
5359 begin
5360 if Nkind (Cstr) = N_Index_Or_Discriminant_Constraint
5361 and then not (Is_Internal (Id)
5362 and then Is_TSS (Scope (Id),
5363 TSS_Composite_Equality))
5364 and then not Within_Init_Proc
5365 and then not All_Composite_Constraints_Static (Cstr)
5366 then
5367 Check_Restriction (No_Dynamic_Sized_Objects, Cstr);
5368 end if;
5369 end;
5370 end if;
5371 end Analyze_Subtype_Declaration;
5372
5373 --------------------------------
5374 -- Analyze_Subtype_Indication --
5375 --------------------------------
5376
5377 procedure Analyze_Subtype_Indication (N : Node_Id) is
5378 T : constant Entity_Id := Subtype_Mark (N);
5379 R : constant Node_Id := Range_Expression (Constraint (N));
5380
5381 begin
5382 Analyze (T);
5383
5384 if R /= Error then
5385 Analyze (R);
5386 Set_Etype (N, Etype (R));
5387 Resolve (R, Entity (T));
5388 else
5389 Set_Error_Posted (R);
5390 Set_Error_Posted (T);
5391 end if;
5392 end Analyze_Subtype_Indication;
5393
5394 --------------------------
5395 -- Analyze_Variant_Part --
5396 --------------------------
5397
5398 procedure Analyze_Variant_Part (N : Node_Id) is
5399 Discr_Name : Node_Id;
5400 Discr_Type : Entity_Id;
5401
5402 procedure Process_Variant (A : Node_Id);
5403 -- Analyze declarations for a single variant
5404
5405 package Analyze_Variant_Choices is
5406 new Generic_Analyze_Choices (Process_Variant);
5407 use Analyze_Variant_Choices;
5408
5409 ---------------------
5410 -- Process_Variant --
5411 ---------------------
5412
5413 procedure Process_Variant (A : Node_Id) is
5414 CL : constant Node_Id := Component_List (A);
5415 begin
5416 if not Null_Present (CL) then
5417 Analyze_Declarations (Component_Items (CL));
5418
5419 if Present (Variant_Part (CL)) then
5420 Analyze (Variant_Part (CL));
5421 end if;
5422 end if;
5423 end Process_Variant;
5424
5425 -- Start of processing for Analyze_Variant_Part
5426
5427 begin
5428 Discr_Name := Name (N);
5429 Analyze (Discr_Name);
5430
5431 -- If Discr_Name bad, get out (prevent cascaded errors)
5432
5433 if Etype (Discr_Name) = Any_Type then
5434 return;
5435 end if;
5436
5437 -- Check invalid discriminant in variant part
5438
5439 if Ekind (Entity (Discr_Name)) /= E_Discriminant then
5440 Error_Msg_N ("invalid discriminant name in variant part", Discr_Name);
5441 end if;
5442
5443 Discr_Type := Etype (Entity (Discr_Name));
5444
5445 if not Is_Discrete_Type (Discr_Type) then
5446 Error_Msg_N
5447 ("discriminant in a variant part must be of a discrete type",
5448 Name (N));
5449 return;
5450 end if;
5451
5452 -- Now analyze the choices, which also analyzes the declarations that
5453 -- are associated with each choice.
5454
5455 Analyze_Choices (Variants (N), Discr_Type);
5456
5457 -- Note: we used to instantiate and call Check_Choices here to check
5458 -- that the choices covered the discriminant, but it's too early to do
5459 -- that because of statically predicated subtypes, whose analysis may
5460 -- be deferred to their freeze point which may be as late as the freeze
5461 -- point of the containing record. So this call is now to be found in
5462 -- Freeze_Record_Declaration.
5463
5464 end Analyze_Variant_Part;
5465
5466 ----------------------------
5467 -- Array_Type_Declaration --
5468 ----------------------------
5469
5470 procedure Array_Type_Declaration (T : in out Entity_Id; Def : Node_Id) is
5471 Component_Def : constant Node_Id := Component_Definition (Def);
5472 Component_Typ : constant Node_Id := Subtype_Indication (Component_Def);
5473 Element_Type : Entity_Id;
5474 Implicit_Base : Entity_Id;
5475 Index : Node_Id;
5476 Related_Id : Entity_Id := Empty;
5477 Nb_Index : Nat;
5478 P : constant Node_Id := Parent (Def);
5479 Priv : Entity_Id;
5480
5481 begin
5482 if Nkind (Def) = N_Constrained_Array_Definition then
5483 Index := First (Discrete_Subtype_Definitions (Def));
5484 else
5485 Index := First (Subtype_Marks (Def));
5486 end if;
5487
5488 -- Find proper names for the implicit types which may be public. In case
5489 -- of anonymous arrays we use the name of the first object of that type
5490 -- as prefix.
5491
5492 if No (T) then
5493 Related_Id := Defining_Identifier (P);
5494 else
5495 Related_Id := T;
5496 end if;
5497
5498 Nb_Index := 1;
5499 while Present (Index) loop
5500 Analyze (Index);
5501
5502 -- Test for odd case of trying to index a type by the type itself
5503
5504 if Is_Entity_Name (Index) and then Entity (Index) = T then
5505 Error_Msg_N ("type& cannot be indexed by itself", Index);
5506 Set_Entity (Index, Standard_Boolean);
5507 Set_Etype (Index, Standard_Boolean);
5508 end if;
5509
5510 -- Check SPARK restriction requiring a subtype mark
5511
5512 if not Nkind_In (Index, N_Identifier, N_Expanded_Name) then
5513 Check_SPARK_05_Restriction ("subtype mark required", Index);
5514 end if;
5515
5516 -- Add a subtype declaration for each index of private array type
5517 -- declaration whose etype is also private. For example:
5518
5519 -- package Pkg is
5520 -- type Index is private;
5521 -- private
5522 -- type Table is array (Index) of ...
5523 -- end;
5524
5525 -- This is currently required by the expander for the internally
5526 -- generated equality subprogram of records with variant parts in
5527 -- which the etype of some component is such private type.
5528
5529 if Ekind (Current_Scope) = E_Package
5530 and then In_Private_Part (Current_Scope)
5531 and then Has_Private_Declaration (Etype (Index))
5532 then
5533 declare
5534 Loc : constant Source_Ptr := Sloc (Def);
5535 New_E : Entity_Id;
5536 Decl : Entity_Id;
5537
5538 begin
5539 New_E := Make_Temporary (Loc, 'T');
5540 Set_Is_Internal (New_E);
5541
5542 Decl :=
5543 Make_Subtype_Declaration (Loc,
5544 Defining_Identifier => New_E,
5545 Subtype_Indication =>
5546 New_Occurrence_Of (Etype (Index), Loc));
5547
5548 Insert_Before (Parent (Def), Decl);
5549 Analyze (Decl);
5550 Set_Etype (Index, New_E);
5551
5552 -- If the index is a range the Entity attribute is not
5553 -- available. Example:
5554
5555 -- package Pkg is
5556 -- type T is private;
5557 -- private
5558 -- type T is new Natural;
5559 -- Table : array (T(1) .. T(10)) of Boolean;
5560 -- end Pkg;
5561
5562 if Nkind (Index) /= N_Range then
5563 Set_Entity (Index, New_E);
5564 end if;
5565 end;
5566 end if;
5567
5568 Make_Index (Index, P, Related_Id, Nb_Index);
5569
5570 -- Check error of subtype with predicate for index type
5571
5572 Bad_Predicated_Subtype_Use
5573 ("subtype& has predicate, not allowed as index subtype",
5574 Index, Etype (Index));
5575
5576 -- Move to next index
5577
5578 Next_Index (Index);
5579 Nb_Index := Nb_Index + 1;
5580 end loop;
5581
5582 -- Process subtype indication if one is present
5583
5584 if Present (Component_Typ) then
5585 Element_Type := Process_Subtype (Component_Typ, P, Related_Id, 'C');
5586
5587 Set_Etype (Component_Typ, Element_Type);
5588
5589 if not Nkind_In (Component_Typ, N_Identifier, N_Expanded_Name) then
5590 Check_SPARK_05_Restriction
5591 ("subtype mark required", Component_Typ);
5592 end if;
5593
5594 -- Ada 2005 (AI-230): Access Definition case
5595
5596 else pragma Assert (Present (Access_Definition (Component_Def)));
5597
5598 -- Indicate that the anonymous access type is created by the
5599 -- array type declaration.
5600
5601 Element_Type := Access_Definition
5602 (Related_Nod => P,
5603 N => Access_Definition (Component_Def));
5604 Set_Is_Local_Anonymous_Access (Element_Type);
5605
5606 -- Propagate the parent. This field is needed if we have to generate
5607 -- the master_id associated with an anonymous access to task type
5608 -- component (see Expand_N_Full_Type_Declaration.Build_Master)
5609
5610 Set_Parent (Element_Type, Parent (T));
5611
5612 -- Ada 2005 (AI-230): In case of components that are anonymous access
5613 -- types the level of accessibility depends on the enclosing type
5614 -- declaration
5615
5616 Set_Scope (Element_Type, Current_Scope); -- Ada 2005 (AI-230)
5617
5618 -- Ada 2005 (AI-254)
5619
5620 declare
5621 CD : constant Node_Id :=
5622 Access_To_Subprogram_Definition
5623 (Access_Definition (Component_Def));
5624 begin
5625 if Present (CD) and then Protected_Present (CD) then
5626 Element_Type :=
5627 Replace_Anonymous_Access_To_Protected_Subprogram (Def);
5628 end if;
5629 end;
5630 end if;
5631
5632 -- Constrained array case
5633
5634 if No (T) then
5635 T := Create_Itype (E_Void, P, Related_Id, 'T');
5636 end if;
5637
5638 if Nkind (Def) = N_Constrained_Array_Definition then
5639
5640 -- Establish Implicit_Base as unconstrained base type
5641
5642 Implicit_Base := Create_Itype (E_Array_Type, P, Related_Id, 'B');
5643
5644 Set_Etype (Implicit_Base, Implicit_Base);
5645 Set_Scope (Implicit_Base, Current_Scope);
5646 Set_Has_Delayed_Freeze (Implicit_Base);
5647 Set_Default_SSO (Implicit_Base);
5648
5649 -- The constrained array type is a subtype of the unconstrained one
5650
5651 Set_Ekind (T, E_Array_Subtype);
5652 Init_Size_Align (T);
5653 Set_Etype (T, Implicit_Base);
5654 Set_Scope (T, Current_Scope);
5655 Set_Is_Constrained (T);
5656 Set_First_Index (T,
5657 First (Discrete_Subtype_Definitions (Def)));
5658 Set_Has_Delayed_Freeze (T);
5659
5660 -- Complete setup of implicit base type
5661
5662 Set_Component_Size (Implicit_Base, Uint_0);
5663 Set_Component_Type (Implicit_Base, Element_Type);
5664 Set_Finalize_Storage_Only
5665 (Implicit_Base,
5666 Finalize_Storage_Only (Element_Type));
5667 Set_First_Index (Implicit_Base, First_Index (T));
5668 Set_Has_Controlled_Component
5669 (Implicit_Base,
5670 Has_Controlled_Component (Element_Type)
5671 or else Is_Controlled_Active (Element_Type));
5672 Set_Packed_Array_Impl_Type
5673 (Implicit_Base, Empty);
5674
5675 Propagate_Concurrent_Flags (Implicit_Base, Element_Type);
5676
5677 -- Inherit the "ghostness" from the constrained array type
5678
5679 if Ghost_Mode > None or else Is_Ghost_Entity (T) then
5680 Set_Is_Ghost_Entity (Implicit_Base);
5681 end if;
5682
5683 -- Unconstrained array case
5684
5685 else
5686 Set_Ekind (T, E_Array_Type);
5687 Init_Size_Align (T);
5688 Set_Etype (T, T);
5689 Set_Scope (T, Current_Scope);
5690 Set_Component_Size (T, Uint_0);
5691 Set_Is_Constrained (T, False);
5692 Set_First_Index (T, First (Subtype_Marks (Def)));
5693 Set_Has_Delayed_Freeze (T, True);
5694 Propagate_Concurrent_Flags (T, Element_Type);
5695 Set_Has_Controlled_Component (T, Has_Controlled_Component
5696 (Element_Type)
5697 or else
5698 Is_Controlled_Active (Element_Type));
5699 Set_Finalize_Storage_Only (T, Finalize_Storage_Only
5700 (Element_Type));
5701 Set_Default_SSO (T);
5702 end if;
5703
5704 -- Common attributes for both cases
5705
5706 Set_Component_Type (Base_Type (T), Element_Type);
5707 Set_Packed_Array_Impl_Type (T, Empty);
5708
5709 if Aliased_Present (Component_Definition (Def)) then
5710 Check_SPARK_05_Restriction
5711 ("aliased is not allowed", Component_Definition (Def));
5712 Set_Has_Aliased_Components (Etype (T));
5713 end if;
5714
5715 -- Ada 2005 (AI-231): Propagate the null-excluding attribute to the
5716 -- array type to ensure that objects of this type are initialized.
5717
5718 if Ada_Version >= Ada_2005 and then Can_Never_Be_Null (Element_Type) then
5719 Set_Can_Never_Be_Null (T);
5720
5721 if Null_Exclusion_Present (Component_Definition (Def))
5722
5723 -- No need to check itypes because in their case this check was
5724 -- done at their point of creation
5725
5726 and then not Is_Itype (Element_Type)
5727 then
5728 Error_Msg_N
5729 ("`NOT NULL` not allowed (null already excluded)",
5730 Subtype_Indication (Component_Definition (Def)));
5731 end if;
5732 end if;
5733
5734 Priv := Private_Component (Element_Type);
5735
5736 if Present (Priv) then
5737
5738 -- Check for circular definitions
5739
5740 if Priv = Any_Type then
5741 Set_Component_Type (Etype (T), Any_Type);
5742
5743 -- There is a gap in the visibility of operations on the composite
5744 -- type only if the component type is defined in a different scope.
5745
5746 elsif Scope (Priv) = Current_Scope then
5747 null;
5748
5749 elsif Is_Limited_Type (Priv) then
5750 Set_Is_Limited_Composite (Etype (T));
5751 Set_Is_Limited_Composite (T);
5752 else
5753 Set_Is_Private_Composite (Etype (T));
5754 Set_Is_Private_Composite (T);
5755 end if;
5756 end if;
5757
5758 -- A syntax error in the declaration itself may lead to an empty index
5759 -- list, in which case do a minimal patch.
5760
5761 if No (First_Index (T)) then
5762 Error_Msg_N ("missing index definition in array type declaration", T);
5763
5764 declare
5765 Indexes : constant List_Id :=
5766 New_List (New_Occurrence_Of (Any_Id, Sloc (T)));
5767 begin
5768 Set_Discrete_Subtype_Definitions (Def, Indexes);
5769 Set_First_Index (T, First (Indexes));
5770 return;
5771 end;
5772 end if;
5773
5774 -- Create a concatenation operator for the new type. Internal array
5775 -- types created for packed entities do not need such, they are
5776 -- compatible with the user-defined type.
5777
5778 if Number_Dimensions (T) = 1
5779 and then not Is_Packed_Array_Impl_Type (T)
5780 then
5781 New_Concatenation_Op (T);
5782 end if;
5783
5784 -- In the case of an unconstrained array the parser has already verified
5785 -- that all the indexes are unconstrained but we still need to make sure
5786 -- that the element type is constrained.
5787
5788 if not Is_Definite_Subtype (Element_Type) then
5789 Error_Msg_N
5790 ("unconstrained element type in array declaration",
5791 Subtype_Indication (Component_Def));
5792
5793 elsif Is_Abstract_Type (Element_Type) then
5794 Error_Msg_N
5795 ("the type of a component cannot be abstract",
5796 Subtype_Indication (Component_Def));
5797 end if;
5798
5799 -- There may be an invariant declared for the component type, but
5800 -- the construction of the component invariant checking procedure
5801 -- takes place during expansion.
5802 end Array_Type_Declaration;
5803
5804 ------------------------------------------------------
5805 -- Replace_Anonymous_Access_To_Protected_Subprogram --
5806 ------------------------------------------------------
5807
5808 function Replace_Anonymous_Access_To_Protected_Subprogram
5809 (N : Node_Id) return Entity_Id
5810 is
5811 Loc : constant Source_Ptr := Sloc (N);
5812
5813 Curr_Scope : constant Scope_Stack_Entry :=
5814 Scope_Stack.Table (Scope_Stack.Last);
5815
5816 Anon : constant Entity_Id := Make_Temporary (Loc, 'S');
5817
5818 Acc : Node_Id;
5819 -- Access definition in declaration
5820
5821 Comp : Node_Id;
5822 -- Object definition or formal definition with an access definition
5823
5824 Decl : Node_Id;
5825 -- Declaration of anonymous access to subprogram type
5826
5827 Spec : Node_Id;
5828 -- Original specification in access to subprogram
5829
5830 P : Node_Id;
5831
5832 begin
5833 Set_Is_Internal (Anon);
5834
5835 case Nkind (N) is
5836 when N_Component_Declaration |
5837 N_Unconstrained_Array_Definition |
5838 N_Constrained_Array_Definition =>
5839 Comp := Component_Definition (N);
5840 Acc := Access_Definition (Comp);
5841
5842 when N_Discriminant_Specification =>
5843 Comp := Discriminant_Type (N);
5844 Acc := Comp;
5845
5846 when N_Parameter_Specification =>
5847 Comp := Parameter_Type (N);
5848 Acc := Comp;
5849
5850 when N_Access_Function_Definition =>
5851 Comp := Result_Definition (N);
5852 Acc := Comp;
5853
5854 when N_Object_Declaration =>
5855 Comp := Object_Definition (N);
5856 Acc := Comp;
5857
5858 when N_Function_Specification =>
5859 Comp := Result_Definition (N);
5860 Acc := Comp;
5861
5862 when others =>
5863 raise Program_Error;
5864 end case;
5865
5866 Spec := Access_To_Subprogram_Definition (Acc);
5867
5868 Decl :=
5869 Make_Full_Type_Declaration (Loc,
5870 Defining_Identifier => Anon,
5871 Type_Definition => Copy_Separate_Tree (Spec));
5872
5873 Mark_Rewrite_Insertion (Decl);
5874
5875 -- In ASIS mode, analyze the profile on the original node, because
5876 -- the separate copy does not provide enough links to recover the
5877 -- original tree. Analysis is limited to type annotations, within
5878 -- a temporary scope that serves as an anonymous subprogram to collect
5879 -- otherwise useless temporaries and itypes.
5880
5881 if ASIS_Mode then
5882 declare
5883 Typ : constant Entity_Id := Make_Temporary (Loc, 'S');
5884
5885 begin
5886 if Nkind (Spec) = N_Access_Function_Definition then
5887 Set_Ekind (Typ, E_Function);
5888 else
5889 Set_Ekind (Typ, E_Procedure);
5890 end if;
5891
5892 Set_Parent (Typ, N);
5893 Set_Scope (Typ, Current_Scope);
5894 Push_Scope (Typ);
5895
5896 -- Nothing to do if procedure is parameterless
5897
5898 if Present (Parameter_Specifications (Spec)) then
5899 Process_Formals (Parameter_Specifications (Spec), Spec);
5900 end if;
5901
5902 if Nkind (Spec) = N_Access_Function_Definition then
5903 declare
5904 Def : constant Node_Id := Result_Definition (Spec);
5905
5906 begin
5907 -- The result might itself be an anonymous access type, so
5908 -- have to recurse.
5909
5910 if Nkind (Def) = N_Access_Definition then
5911 if Present (Access_To_Subprogram_Definition (Def)) then
5912 Set_Etype
5913 (Def,
5914 Replace_Anonymous_Access_To_Protected_Subprogram
5915 (Spec));
5916 else
5917 Find_Type (Subtype_Mark (Def));
5918 end if;
5919
5920 else
5921 Find_Type (Def);
5922 end if;
5923 end;
5924 end if;
5925
5926 End_Scope;
5927 end;
5928 end if;
5929
5930 -- Insert the new declaration in the nearest enclosing scope. If the
5931 -- node is a body and N is its return type, the declaration belongs in
5932 -- the enclosing scope.
5933
5934 P := Parent (N);
5935
5936 if Nkind (P) = N_Subprogram_Body
5937 and then Nkind (N) = N_Function_Specification
5938 then
5939 P := Parent (P);
5940 end if;
5941
5942 while Present (P) and then not Has_Declarations (P) loop
5943 P := Parent (P);
5944 end loop;
5945
5946 pragma Assert (Present (P));
5947
5948 if Nkind (P) = N_Package_Specification then
5949 Prepend (Decl, Visible_Declarations (P));
5950 else
5951 Prepend (Decl, Declarations (P));
5952 end if;
5953
5954 -- Replace the anonymous type with an occurrence of the new declaration.
5955 -- In all cases the rewritten node does not have the null-exclusion
5956 -- attribute because (if present) it was already inherited by the
5957 -- anonymous entity (Anon). Thus, in case of components we do not
5958 -- inherit this attribute.
5959
5960 if Nkind (N) = N_Parameter_Specification then
5961 Rewrite (Comp, New_Occurrence_Of (Anon, Loc));
5962 Set_Etype (Defining_Identifier (N), Anon);
5963 Set_Null_Exclusion_Present (N, False);
5964
5965 elsif Nkind (N) = N_Object_Declaration then
5966 Rewrite (Comp, New_Occurrence_Of (Anon, Loc));
5967 Set_Etype (Defining_Identifier (N), Anon);
5968
5969 elsif Nkind (N) = N_Access_Function_Definition then
5970 Rewrite (Comp, New_Occurrence_Of (Anon, Loc));
5971
5972 elsif Nkind (N) = N_Function_Specification then
5973 Rewrite (Comp, New_Occurrence_Of (Anon, Loc));
5974 Set_Etype (Defining_Unit_Name (N), Anon);
5975
5976 else
5977 Rewrite (Comp,
5978 Make_Component_Definition (Loc,
5979 Subtype_Indication => New_Occurrence_Of (Anon, Loc)));
5980 end if;
5981
5982 Mark_Rewrite_Insertion (Comp);
5983
5984 if Nkind_In (N, N_Object_Declaration, N_Access_Function_Definition)
5985 or else (Nkind (Parent (N)) = N_Full_Type_Declaration
5986 and then not Is_Type (Current_Scope))
5987 then
5988
5989 -- Declaration can be analyzed in the current scope.
5990
5991 Analyze (Decl);
5992
5993 else
5994 -- Temporarily remove the current scope (record or subprogram) from
5995 -- the stack to add the new declarations to the enclosing scope.
5996 -- The anonymous entity is an Itype with the proper attributes.
5997
5998 Scope_Stack.Decrement_Last;
5999 Analyze (Decl);
6000 Set_Is_Itype (Anon);
6001 Set_Associated_Node_For_Itype (Anon, N);
6002 Scope_Stack.Append (Curr_Scope);
6003 end if;
6004
6005 Set_Ekind (Anon, E_Anonymous_Access_Protected_Subprogram_Type);
6006 Set_Can_Use_Internal_Rep (Anon, not Always_Compatible_Rep_On_Target);
6007 return Anon;
6008 end Replace_Anonymous_Access_To_Protected_Subprogram;
6009
6010 -------------------------------
6011 -- Build_Derived_Access_Type --
6012 -------------------------------
6013
6014 procedure Build_Derived_Access_Type
6015 (N : Node_Id;
6016 Parent_Type : Entity_Id;
6017 Derived_Type : Entity_Id)
6018 is
6019 S : constant Node_Id := Subtype_Indication (Type_Definition (N));
6020
6021 Desig_Type : Entity_Id;
6022 Discr : Entity_Id;
6023 Discr_Con_Elist : Elist_Id;
6024 Discr_Con_El : Elmt_Id;
6025 Subt : Entity_Id;
6026
6027 begin
6028 -- Set the designated type so it is available in case this is an access
6029 -- to a self-referential type, e.g. a standard list type with a next
6030 -- pointer. Will be reset after subtype is built.
6031
6032 Set_Directly_Designated_Type
6033 (Derived_Type, Designated_Type (Parent_Type));
6034
6035 Subt := Process_Subtype (S, N);
6036
6037 if Nkind (S) /= N_Subtype_Indication
6038 and then Subt /= Base_Type (Subt)
6039 then
6040 Set_Ekind (Derived_Type, E_Access_Subtype);
6041 end if;
6042
6043 if Ekind (Derived_Type) = E_Access_Subtype then
6044 declare
6045 Pbase : constant Entity_Id := Base_Type (Parent_Type);
6046 Ibase : constant Entity_Id :=
6047 Create_Itype (Ekind (Pbase), N, Derived_Type, 'B');
6048 Svg_Chars : constant Name_Id := Chars (Ibase);
6049 Svg_Next_E : constant Entity_Id := Next_Entity (Ibase);
6050
6051 begin
6052 Copy_Node (Pbase, Ibase);
6053
6054 Set_Chars (Ibase, Svg_Chars);
6055 Set_Next_Entity (Ibase, Svg_Next_E);
6056 Set_Sloc (Ibase, Sloc (Derived_Type));
6057 Set_Scope (Ibase, Scope (Derived_Type));
6058 Set_Freeze_Node (Ibase, Empty);
6059 Set_Is_Frozen (Ibase, False);
6060 Set_Comes_From_Source (Ibase, False);
6061 Set_Is_First_Subtype (Ibase, False);
6062
6063 Set_Etype (Ibase, Pbase);
6064 Set_Etype (Derived_Type, Ibase);
6065 end;
6066 end if;
6067
6068 Set_Directly_Designated_Type
6069 (Derived_Type, Designated_Type (Subt));
6070
6071 Set_Is_Constrained (Derived_Type, Is_Constrained (Subt));
6072 Set_Is_Access_Constant (Derived_Type, Is_Access_Constant (Parent_Type));
6073 Set_Size_Info (Derived_Type, Parent_Type);
6074 Set_RM_Size (Derived_Type, RM_Size (Parent_Type));
6075 Set_Depends_On_Private (Derived_Type,
6076 Has_Private_Component (Derived_Type));
6077 Conditional_Delay (Derived_Type, Subt);
6078
6079 -- Ada 2005 (AI-231): Set the null-exclusion attribute, and verify
6080 -- that it is not redundant.
6081
6082 if Null_Exclusion_Present (Type_Definition (N)) then
6083 Set_Can_Never_Be_Null (Derived_Type);
6084
6085 elsif Can_Never_Be_Null (Parent_Type) then
6086 Set_Can_Never_Be_Null (Derived_Type);
6087 end if;
6088
6089 -- Note: we do not copy the Storage_Size_Variable, since we always go to
6090 -- the root type for this information.
6091
6092 -- Apply range checks to discriminants for derived record case
6093 -- ??? THIS CODE SHOULD NOT BE HERE REALLY.
6094
6095 Desig_Type := Designated_Type (Derived_Type);
6096
6097 if Is_Composite_Type (Desig_Type)
6098 and then (not Is_Array_Type (Desig_Type))
6099 and then Has_Discriminants (Desig_Type)
6100 and then Base_Type (Desig_Type) /= Desig_Type
6101 then
6102 Discr_Con_Elist := Discriminant_Constraint (Desig_Type);
6103 Discr_Con_El := First_Elmt (Discr_Con_Elist);
6104
6105 Discr := First_Discriminant (Base_Type (Desig_Type));
6106 while Present (Discr_Con_El) loop
6107 Apply_Range_Check (Node (Discr_Con_El), Etype (Discr));
6108 Next_Elmt (Discr_Con_El);
6109 Next_Discriminant (Discr);
6110 end loop;
6111 end if;
6112 end Build_Derived_Access_Type;
6113
6114 ------------------------------
6115 -- Build_Derived_Array_Type --
6116 ------------------------------
6117
6118 procedure Build_Derived_Array_Type
6119 (N : Node_Id;
6120 Parent_Type : Entity_Id;
6121 Derived_Type : Entity_Id)
6122 is
6123 Loc : constant Source_Ptr := Sloc (N);
6124 Tdef : constant Node_Id := Type_Definition (N);
6125 Indic : constant Node_Id := Subtype_Indication (Tdef);
6126 Parent_Base : constant Entity_Id := Base_Type (Parent_Type);
6127 Implicit_Base : Entity_Id;
6128 New_Indic : Node_Id;
6129
6130 procedure Make_Implicit_Base;
6131 -- If the parent subtype is constrained, the derived type is a subtype
6132 -- of an implicit base type derived from the parent base.
6133
6134 ------------------------
6135 -- Make_Implicit_Base --
6136 ------------------------
6137
6138 procedure Make_Implicit_Base is
6139 begin
6140 Implicit_Base :=
6141 Create_Itype (Ekind (Parent_Base), N, Derived_Type, 'B');
6142
6143 Set_Ekind (Implicit_Base, Ekind (Parent_Base));
6144 Set_Etype (Implicit_Base, Parent_Base);
6145
6146 Copy_Array_Subtype_Attributes (Implicit_Base, Parent_Base);
6147 Copy_Array_Base_Type_Attributes (Implicit_Base, Parent_Base);
6148
6149 Set_Has_Delayed_Freeze (Implicit_Base, True);
6150
6151 -- Inherit the "ghostness" from the parent base type
6152
6153 if Ghost_Mode > None or else Is_Ghost_Entity (Parent_Base) then
6154 Set_Is_Ghost_Entity (Implicit_Base);
6155 end if;
6156 end Make_Implicit_Base;
6157
6158 -- Start of processing for Build_Derived_Array_Type
6159
6160 begin
6161 if not Is_Constrained (Parent_Type) then
6162 if Nkind (Indic) /= N_Subtype_Indication then
6163 Set_Ekind (Derived_Type, E_Array_Type);
6164
6165 Copy_Array_Subtype_Attributes (Derived_Type, Parent_Type);
6166 Copy_Array_Base_Type_Attributes (Derived_Type, Parent_Type);
6167
6168 Set_Has_Delayed_Freeze (Derived_Type, True);
6169
6170 else
6171 Make_Implicit_Base;
6172 Set_Etype (Derived_Type, Implicit_Base);
6173
6174 New_Indic :=
6175 Make_Subtype_Declaration (Loc,
6176 Defining_Identifier => Derived_Type,
6177 Subtype_Indication =>
6178 Make_Subtype_Indication (Loc,
6179 Subtype_Mark => New_Occurrence_Of (Implicit_Base, Loc),
6180 Constraint => Constraint (Indic)));
6181
6182 Rewrite (N, New_Indic);
6183 Analyze (N);
6184 end if;
6185
6186 else
6187 if Nkind (Indic) /= N_Subtype_Indication then
6188 Make_Implicit_Base;
6189
6190 Set_Ekind (Derived_Type, Ekind (Parent_Type));
6191 Set_Etype (Derived_Type, Implicit_Base);
6192 Copy_Array_Subtype_Attributes (Derived_Type, Parent_Type);
6193
6194 else
6195 Error_Msg_N ("illegal constraint on constrained type", Indic);
6196 end if;
6197 end if;
6198
6199 -- If parent type is not a derived type itself, and is declared in
6200 -- closed scope (e.g. a subprogram), then we must explicitly introduce
6201 -- the new type's concatenation operator since Derive_Subprograms
6202 -- will not inherit the parent's operator. If the parent type is
6203 -- unconstrained, the operator is of the unconstrained base type.
6204
6205 if Number_Dimensions (Parent_Type) = 1
6206 and then not Is_Limited_Type (Parent_Type)
6207 and then not Is_Derived_Type (Parent_Type)
6208 and then not Is_Package_Or_Generic_Package
6209 (Scope (Base_Type (Parent_Type)))
6210 then
6211 if not Is_Constrained (Parent_Type)
6212 and then Is_Constrained (Derived_Type)
6213 then
6214 New_Concatenation_Op (Implicit_Base);
6215 else
6216 New_Concatenation_Op (Derived_Type);
6217 end if;
6218 end if;
6219 end Build_Derived_Array_Type;
6220
6221 -----------------------------------
6222 -- Build_Derived_Concurrent_Type --
6223 -----------------------------------
6224
6225 procedure Build_Derived_Concurrent_Type
6226 (N : Node_Id;
6227 Parent_Type : Entity_Id;
6228 Derived_Type : Entity_Id)
6229 is
6230 Loc : constant Source_Ptr := Sloc (N);
6231
6232 Corr_Record : constant Entity_Id := Make_Temporary (Loc, 'C');
6233 Corr_Decl : Node_Id;
6234 Corr_Decl_Needed : Boolean;
6235 -- If the derived type has fewer discriminants than its parent, the
6236 -- corresponding record is also a derived type, in order to account for
6237 -- the bound discriminants. We create a full type declaration for it in
6238 -- this case.
6239
6240 Constraint_Present : constant Boolean :=
6241 Nkind (Subtype_Indication (Type_Definition (N))) =
6242 N_Subtype_Indication;
6243
6244 D_Constraint : Node_Id;
6245 New_Constraint : Elist_Id;
6246 Old_Disc : Entity_Id;
6247 New_Disc : Entity_Id;
6248 New_N : Node_Id;
6249
6250 begin
6251 Set_Stored_Constraint (Derived_Type, No_Elist);
6252 Corr_Decl_Needed := False;
6253 Old_Disc := Empty;
6254
6255 if Present (Discriminant_Specifications (N))
6256 and then Constraint_Present
6257 then
6258 Old_Disc := First_Discriminant (Parent_Type);
6259 New_Disc := First (Discriminant_Specifications (N));
6260 while Present (New_Disc) and then Present (Old_Disc) loop
6261 Next_Discriminant (Old_Disc);
6262 Next (New_Disc);
6263 end loop;
6264 end if;
6265
6266 if Present (Old_Disc) and then Expander_Active then
6267
6268 -- The new type has fewer discriminants, so we need to create a new
6269 -- corresponding record, which is derived from the corresponding
6270 -- record of the parent, and has a stored constraint that captures
6271 -- the values of the discriminant constraints. The corresponding
6272 -- record is needed only if expander is active and code generation is
6273 -- enabled.
6274
6275 -- The type declaration for the derived corresponding record has the
6276 -- same discriminant part and constraints as the current declaration.
6277 -- Copy the unanalyzed tree to build declaration.
6278
6279 Corr_Decl_Needed := True;
6280 New_N := Copy_Separate_Tree (N);
6281
6282 Corr_Decl :=
6283 Make_Full_Type_Declaration (Loc,
6284 Defining_Identifier => Corr_Record,
6285 Discriminant_Specifications =>
6286 Discriminant_Specifications (New_N),
6287 Type_Definition =>
6288 Make_Derived_Type_Definition (Loc,
6289 Subtype_Indication =>
6290 Make_Subtype_Indication (Loc,
6291 Subtype_Mark =>
6292 New_Occurrence_Of
6293 (Corresponding_Record_Type (Parent_Type), Loc),
6294 Constraint =>
6295 Constraint
6296 (Subtype_Indication (Type_Definition (New_N))))));
6297 end if;
6298
6299 -- Copy Storage_Size and Relative_Deadline variables if task case
6300
6301 if Is_Task_Type (Parent_Type) then
6302 Set_Storage_Size_Variable (Derived_Type,
6303 Storage_Size_Variable (Parent_Type));
6304 Set_Relative_Deadline_Variable (Derived_Type,
6305 Relative_Deadline_Variable (Parent_Type));
6306 end if;
6307
6308 if Present (Discriminant_Specifications (N)) then
6309 Push_Scope (Derived_Type);
6310 Check_Or_Process_Discriminants (N, Derived_Type);
6311
6312 if Constraint_Present then
6313 New_Constraint :=
6314 Expand_To_Stored_Constraint
6315 (Parent_Type,
6316 Build_Discriminant_Constraints
6317 (Parent_Type,
6318 Subtype_Indication (Type_Definition (N)), True));
6319 end if;
6320
6321 End_Scope;
6322
6323 elsif Constraint_Present then
6324
6325 -- Build constrained subtype, copying the constraint, and derive
6326 -- from it to create a derived constrained type.
6327
6328 declare
6329 Loc : constant Source_Ptr := Sloc (N);
6330 Anon : constant Entity_Id :=
6331 Make_Defining_Identifier (Loc,
6332 Chars => New_External_Name (Chars (Derived_Type), 'T'));
6333 Decl : Node_Id;
6334
6335 begin
6336 Decl :=
6337 Make_Subtype_Declaration (Loc,
6338 Defining_Identifier => Anon,
6339 Subtype_Indication =>
6340 New_Copy_Tree (Subtype_Indication (Type_Definition (N))));
6341 Insert_Before (N, Decl);
6342 Analyze (Decl);
6343
6344 Rewrite (Subtype_Indication (Type_Definition (N)),
6345 New_Occurrence_Of (Anon, Loc));
6346 Set_Analyzed (Derived_Type, False);
6347 Analyze (N);
6348 return;
6349 end;
6350 end if;
6351
6352 -- By default, operations and private data are inherited from parent.
6353 -- However, in the presence of bound discriminants, a new corresponding
6354 -- record will be created, see below.
6355
6356 Set_Has_Discriminants
6357 (Derived_Type, Has_Discriminants (Parent_Type));
6358 Set_Corresponding_Record_Type
6359 (Derived_Type, Corresponding_Record_Type (Parent_Type));
6360
6361 -- Is_Constrained is set according the parent subtype, but is set to
6362 -- False if the derived type is declared with new discriminants.
6363
6364 Set_Is_Constrained
6365 (Derived_Type,
6366 (Is_Constrained (Parent_Type) or else Constraint_Present)
6367 and then not Present (Discriminant_Specifications (N)));
6368
6369 if Constraint_Present then
6370 if not Has_Discriminants (Parent_Type) then
6371 Error_Msg_N ("untagged parent must have discriminants", N);
6372
6373 elsif Present (Discriminant_Specifications (N)) then
6374
6375 -- Verify that new discriminants are used to constrain old ones
6376
6377 D_Constraint :=
6378 First
6379 (Constraints
6380 (Constraint (Subtype_Indication (Type_Definition (N)))));
6381
6382 Old_Disc := First_Discriminant (Parent_Type);
6383
6384 while Present (D_Constraint) loop
6385 if Nkind (D_Constraint) /= N_Discriminant_Association then
6386
6387 -- Positional constraint. If it is a reference to a new
6388 -- discriminant, it constrains the corresponding old one.
6389
6390 if Nkind (D_Constraint) = N_Identifier then
6391 New_Disc := First_Discriminant (Derived_Type);
6392 while Present (New_Disc) loop
6393 exit when Chars (New_Disc) = Chars (D_Constraint);
6394 Next_Discriminant (New_Disc);
6395 end loop;
6396
6397 if Present (New_Disc) then
6398 Set_Corresponding_Discriminant (New_Disc, Old_Disc);
6399 end if;
6400 end if;
6401
6402 Next_Discriminant (Old_Disc);
6403
6404 -- if this is a named constraint, search by name for the old
6405 -- discriminants constrained by the new one.
6406
6407 elsif Nkind (Expression (D_Constraint)) = N_Identifier then
6408
6409 -- Find new discriminant with that name
6410
6411 New_Disc := First_Discriminant (Derived_Type);
6412 while Present (New_Disc) loop
6413 exit when
6414 Chars (New_Disc) = Chars (Expression (D_Constraint));
6415 Next_Discriminant (New_Disc);
6416 end loop;
6417
6418 if Present (New_Disc) then
6419
6420 -- Verify that new discriminant renames some discriminant
6421 -- of the parent type, and associate the new discriminant
6422 -- with one or more old ones that it renames.
6423
6424 declare
6425 Selector : Node_Id;
6426
6427 begin
6428 Selector := First (Selector_Names (D_Constraint));
6429 while Present (Selector) loop
6430 Old_Disc := First_Discriminant (Parent_Type);
6431 while Present (Old_Disc) loop
6432 exit when Chars (Old_Disc) = Chars (Selector);
6433 Next_Discriminant (Old_Disc);
6434 end loop;
6435
6436 if Present (Old_Disc) then
6437 Set_Corresponding_Discriminant
6438 (New_Disc, Old_Disc);
6439 end if;
6440
6441 Next (Selector);
6442 end loop;
6443 end;
6444 end if;
6445 end if;
6446
6447 Next (D_Constraint);
6448 end loop;
6449
6450 New_Disc := First_Discriminant (Derived_Type);
6451 while Present (New_Disc) loop
6452 if No (Corresponding_Discriminant (New_Disc)) then
6453 Error_Msg_NE
6454 ("new discriminant& must constrain old one", N, New_Disc);
6455
6456 elsif not
6457 Subtypes_Statically_Compatible
6458 (Etype (New_Disc),
6459 Etype (Corresponding_Discriminant (New_Disc)))
6460 then
6461 Error_Msg_NE
6462 ("& not statically compatible with parent discriminant",
6463 N, New_Disc);
6464 end if;
6465
6466 Next_Discriminant (New_Disc);
6467 end loop;
6468 end if;
6469
6470 elsif Present (Discriminant_Specifications (N)) then
6471 Error_Msg_N
6472 ("missing discriminant constraint in untagged derivation", N);
6473 end if;
6474
6475 -- The entity chain of the derived type includes the new discriminants
6476 -- but shares operations with the parent.
6477
6478 if Present (Discriminant_Specifications (N)) then
6479 Old_Disc := First_Discriminant (Parent_Type);
6480 while Present (Old_Disc) loop
6481 if No (Next_Entity (Old_Disc))
6482 or else Ekind (Next_Entity (Old_Disc)) /= E_Discriminant
6483 then
6484 Set_Next_Entity
6485 (Last_Entity (Derived_Type), Next_Entity (Old_Disc));
6486 exit;
6487 end if;
6488
6489 Next_Discriminant (Old_Disc);
6490 end loop;
6491
6492 else
6493 Set_First_Entity (Derived_Type, First_Entity (Parent_Type));
6494 if Has_Discriminants (Parent_Type) then
6495 Set_Is_Constrained (Derived_Type, Is_Constrained (Parent_Type));
6496 Set_Discriminant_Constraint (
6497 Derived_Type, Discriminant_Constraint (Parent_Type));
6498 end if;
6499 end if;
6500
6501 Set_Last_Entity (Derived_Type, Last_Entity (Parent_Type));
6502
6503 Set_Has_Completion (Derived_Type);
6504
6505 if Corr_Decl_Needed then
6506 Set_Stored_Constraint (Derived_Type, New_Constraint);
6507 Insert_After (N, Corr_Decl);
6508 Analyze (Corr_Decl);
6509 Set_Corresponding_Record_Type (Derived_Type, Corr_Record);
6510 end if;
6511 end Build_Derived_Concurrent_Type;
6512
6513 ------------------------------------
6514 -- Build_Derived_Enumeration_Type --
6515 ------------------------------------
6516
6517 procedure Build_Derived_Enumeration_Type
6518 (N : Node_Id;
6519 Parent_Type : Entity_Id;
6520 Derived_Type : Entity_Id)
6521 is
6522 Loc : constant Source_Ptr := Sloc (N);
6523 Def : constant Node_Id := Type_Definition (N);
6524 Indic : constant Node_Id := Subtype_Indication (Def);
6525 Implicit_Base : Entity_Id;
6526 Literal : Entity_Id;
6527 New_Lit : Entity_Id;
6528 Literals_List : List_Id;
6529 Type_Decl : Node_Id;
6530 Hi, Lo : Node_Id;
6531 Rang_Expr : Node_Id;
6532
6533 begin
6534 -- Since types Standard.Character and Standard.[Wide_]Wide_Character do
6535 -- not have explicit literals lists we need to process types derived
6536 -- from them specially. This is handled by Derived_Standard_Character.
6537 -- If the parent type is a generic type, there are no literals either,
6538 -- and we construct the same skeletal representation as for the generic
6539 -- parent type.
6540
6541 if Is_Standard_Character_Type (Parent_Type) then
6542 Derived_Standard_Character (N, Parent_Type, Derived_Type);
6543
6544 elsif Is_Generic_Type (Root_Type (Parent_Type)) then
6545 declare
6546 Lo : Node_Id;
6547 Hi : Node_Id;
6548
6549 begin
6550 if Nkind (Indic) /= N_Subtype_Indication then
6551 Lo :=
6552 Make_Attribute_Reference (Loc,
6553 Attribute_Name => Name_First,
6554 Prefix => New_Occurrence_Of (Derived_Type, Loc));
6555 Set_Etype (Lo, Derived_Type);
6556
6557 Hi :=
6558 Make_Attribute_Reference (Loc,
6559 Attribute_Name => Name_Last,
6560 Prefix => New_Occurrence_Of (Derived_Type, Loc));
6561 Set_Etype (Hi, Derived_Type);
6562
6563 Set_Scalar_Range (Derived_Type,
6564 Make_Range (Loc,
6565 Low_Bound => Lo,
6566 High_Bound => Hi));
6567 else
6568
6569 -- Analyze subtype indication and verify compatibility
6570 -- with parent type.
6571
6572 if Base_Type (Process_Subtype (Indic, N)) /=
6573 Base_Type (Parent_Type)
6574 then
6575 Error_Msg_N
6576 ("illegal constraint for formal discrete type", N);
6577 end if;
6578 end if;
6579 end;
6580
6581 else
6582 -- If a constraint is present, analyze the bounds to catch
6583 -- premature usage of the derived literals.
6584
6585 if Nkind (Indic) = N_Subtype_Indication
6586 and then Nkind (Range_Expression (Constraint (Indic))) = N_Range
6587 then
6588 Analyze (Low_Bound (Range_Expression (Constraint (Indic))));
6589 Analyze (High_Bound (Range_Expression (Constraint (Indic))));
6590 end if;
6591
6592 -- Introduce an implicit base type for the derived type even if there
6593 -- is no constraint attached to it, since this seems closer to the
6594 -- Ada semantics. Build a full type declaration tree for the derived
6595 -- type using the implicit base type as the defining identifier. The
6596 -- build a subtype declaration tree which applies the constraint (if
6597 -- any) have it replace the derived type declaration.
6598
6599 Literal := First_Literal (Parent_Type);
6600 Literals_List := New_List;
6601 while Present (Literal)
6602 and then Ekind (Literal) = E_Enumeration_Literal
6603 loop
6604 -- Literals of the derived type have the same representation as
6605 -- those of the parent type, but this representation can be
6606 -- overridden by an explicit representation clause. Indicate
6607 -- that there is no explicit representation given yet. These
6608 -- derived literals are implicit operations of the new type,
6609 -- and can be overridden by explicit ones.
6610
6611 if Nkind (Literal) = N_Defining_Character_Literal then
6612 New_Lit :=
6613 Make_Defining_Character_Literal (Loc, Chars (Literal));
6614 else
6615 New_Lit := Make_Defining_Identifier (Loc, Chars (Literal));
6616 end if;
6617
6618 Set_Ekind (New_Lit, E_Enumeration_Literal);
6619 Set_Enumeration_Pos (New_Lit, Enumeration_Pos (Literal));
6620 Set_Enumeration_Rep (New_Lit, Enumeration_Rep (Literal));
6621 Set_Enumeration_Rep_Expr (New_Lit, Empty);
6622 Set_Alias (New_Lit, Literal);
6623 Set_Is_Known_Valid (New_Lit, True);
6624
6625 Append (New_Lit, Literals_List);
6626 Next_Literal (Literal);
6627 end loop;
6628
6629 Implicit_Base :=
6630 Make_Defining_Identifier (Sloc (Derived_Type),
6631 Chars => New_External_Name (Chars (Derived_Type), 'B'));
6632
6633 -- Indicate the proper nature of the derived type. This must be done
6634 -- before analysis of the literals, to recognize cases when a literal
6635 -- may be hidden by a previous explicit function definition (cf.
6636 -- c83031a).
6637
6638 Set_Ekind (Derived_Type, E_Enumeration_Subtype);
6639 Set_Etype (Derived_Type, Implicit_Base);
6640
6641 Type_Decl :=
6642 Make_Full_Type_Declaration (Loc,
6643 Defining_Identifier => Implicit_Base,
6644 Discriminant_Specifications => No_List,
6645 Type_Definition =>
6646 Make_Enumeration_Type_Definition (Loc, Literals_List));
6647
6648 Mark_Rewrite_Insertion (Type_Decl);
6649 Insert_Before (N, Type_Decl);
6650 Analyze (Type_Decl);
6651
6652 -- The anonymous base now has a full declaration, but this base
6653 -- is not a first subtype.
6654
6655 Set_Is_First_Subtype (Implicit_Base, False);
6656
6657 -- After the implicit base is analyzed its Etype needs to be changed
6658 -- to reflect the fact that it is derived from the parent type which
6659 -- was ignored during analysis. We also set the size at this point.
6660
6661 Set_Etype (Implicit_Base, Parent_Type);
6662
6663 Set_Size_Info (Implicit_Base, Parent_Type);
6664 Set_RM_Size (Implicit_Base, RM_Size (Parent_Type));
6665 Set_First_Rep_Item (Implicit_Base, First_Rep_Item (Parent_Type));
6666
6667 -- Copy other flags from parent type
6668
6669 Set_Has_Non_Standard_Rep
6670 (Implicit_Base, Has_Non_Standard_Rep
6671 (Parent_Type));
6672 Set_Has_Pragma_Ordered
6673 (Implicit_Base, Has_Pragma_Ordered
6674 (Parent_Type));
6675 Set_Has_Delayed_Freeze (Implicit_Base);
6676
6677 -- Process the subtype indication including a validation check on the
6678 -- constraint, if any. If a constraint is given, its bounds must be
6679 -- implicitly converted to the new type.
6680
6681 if Nkind (Indic) = N_Subtype_Indication then
6682 declare
6683 R : constant Node_Id :=
6684 Range_Expression (Constraint (Indic));
6685
6686 begin
6687 if Nkind (R) = N_Range then
6688 Hi := Build_Scalar_Bound
6689 (High_Bound (R), Parent_Type, Implicit_Base);
6690 Lo := Build_Scalar_Bound
6691 (Low_Bound (R), Parent_Type, Implicit_Base);
6692
6693 else
6694 -- Constraint is a Range attribute. Replace with explicit
6695 -- mention of the bounds of the prefix, which must be a
6696 -- subtype.
6697
6698 Analyze (Prefix (R));
6699 Hi :=
6700 Convert_To (Implicit_Base,
6701 Make_Attribute_Reference (Loc,
6702 Attribute_Name => Name_Last,
6703 Prefix =>
6704 New_Occurrence_Of (Entity (Prefix (R)), Loc)));
6705
6706 Lo :=
6707 Convert_To (Implicit_Base,
6708 Make_Attribute_Reference (Loc,
6709 Attribute_Name => Name_First,
6710 Prefix =>
6711 New_Occurrence_Of (Entity (Prefix (R)), Loc)));
6712 end if;
6713 end;
6714
6715 else
6716 Hi :=
6717 Build_Scalar_Bound
6718 (Type_High_Bound (Parent_Type),
6719 Parent_Type, Implicit_Base);
6720 Lo :=
6721 Build_Scalar_Bound
6722 (Type_Low_Bound (Parent_Type),
6723 Parent_Type, Implicit_Base);
6724 end if;
6725
6726 Rang_Expr :=
6727 Make_Range (Loc,
6728 Low_Bound => Lo,
6729 High_Bound => Hi);
6730
6731 -- If we constructed a default range for the case where no range
6732 -- was given, then the expressions in the range must not freeze
6733 -- since they do not correspond to expressions in the source.
6734
6735 if Nkind (Indic) /= N_Subtype_Indication then
6736 Set_Must_Not_Freeze (Lo);
6737 Set_Must_Not_Freeze (Hi);
6738 Set_Must_Not_Freeze (Rang_Expr);
6739 end if;
6740
6741 Rewrite (N,
6742 Make_Subtype_Declaration (Loc,
6743 Defining_Identifier => Derived_Type,
6744 Subtype_Indication =>
6745 Make_Subtype_Indication (Loc,
6746 Subtype_Mark => New_Occurrence_Of (Implicit_Base, Loc),
6747 Constraint =>
6748 Make_Range_Constraint (Loc,
6749 Range_Expression => Rang_Expr))));
6750
6751 Analyze (N);
6752
6753 -- Propagate the aspects from the original type declaration to the
6754 -- declaration of the implicit base.
6755
6756 Move_Aspects (From => Original_Node (N), To => Type_Decl);
6757
6758 -- Apply a range check. Since this range expression doesn't have an
6759 -- Etype, we have to specifically pass the Source_Typ parameter. Is
6760 -- this right???
6761
6762 if Nkind (Indic) = N_Subtype_Indication then
6763 Apply_Range_Check
6764 (Range_Expression (Constraint (Indic)), Parent_Type,
6765 Source_Typ => Entity (Subtype_Mark (Indic)));
6766 end if;
6767 end if;
6768 end Build_Derived_Enumeration_Type;
6769
6770 --------------------------------
6771 -- Build_Derived_Numeric_Type --
6772 --------------------------------
6773
6774 procedure Build_Derived_Numeric_Type
6775 (N : Node_Id;
6776 Parent_Type : Entity_Id;
6777 Derived_Type : Entity_Id)
6778 is
6779 Loc : constant Source_Ptr := Sloc (N);
6780 Tdef : constant Node_Id := Type_Definition (N);
6781 Indic : constant Node_Id := Subtype_Indication (Tdef);
6782 Parent_Base : constant Entity_Id := Base_Type (Parent_Type);
6783 No_Constraint : constant Boolean := Nkind (Indic) /=
6784 N_Subtype_Indication;
6785 Implicit_Base : Entity_Id;
6786
6787 Lo : Node_Id;
6788 Hi : Node_Id;
6789
6790 begin
6791 -- Process the subtype indication including a validation check on
6792 -- the constraint if any.
6793
6794 Discard_Node (Process_Subtype (Indic, N));
6795
6796 -- Introduce an implicit base type for the derived type even if there
6797 -- is no constraint attached to it, since this seems closer to the Ada
6798 -- semantics.
6799
6800 Implicit_Base :=
6801 Create_Itype (Ekind (Parent_Base), N, Derived_Type, 'B');
6802
6803 Set_Etype (Implicit_Base, Parent_Base);
6804 Set_Ekind (Implicit_Base, Ekind (Parent_Base));
6805 Set_Size_Info (Implicit_Base, Parent_Base);
6806 Set_First_Rep_Item (Implicit_Base, First_Rep_Item (Parent_Base));
6807 Set_Parent (Implicit_Base, Parent (Derived_Type));
6808 Set_Is_Known_Valid (Implicit_Base, Is_Known_Valid (Parent_Base));
6809
6810 -- Set RM Size for discrete type or decimal fixed-point type
6811 -- Ordinary fixed-point is excluded, why???
6812
6813 if Is_Discrete_Type (Parent_Base)
6814 or else Is_Decimal_Fixed_Point_Type (Parent_Base)
6815 then
6816 Set_RM_Size (Implicit_Base, RM_Size (Parent_Base));
6817 end if;
6818
6819 Set_Has_Delayed_Freeze (Implicit_Base);
6820
6821 Lo := New_Copy_Tree (Type_Low_Bound (Parent_Base));
6822 Hi := New_Copy_Tree (Type_High_Bound (Parent_Base));
6823
6824 Set_Scalar_Range (Implicit_Base,
6825 Make_Range (Loc,
6826 Low_Bound => Lo,
6827 High_Bound => Hi));
6828
6829 if Has_Infinities (Parent_Base) then
6830 Set_Includes_Infinities (Scalar_Range (Implicit_Base));
6831 end if;
6832
6833 -- The Derived_Type, which is the entity of the declaration, is a
6834 -- subtype of the implicit base. Its Ekind is a subtype, even in the
6835 -- absence of an explicit constraint.
6836
6837 Set_Etype (Derived_Type, Implicit_Base);
6838
6839 -- If we did not have a constraint, then the Ekind is set from the
6840 -- parent type (otherwise Process_Subtype has set the bounds)
6841
6842 if No_Constraint then
6843 Set_Ekind (Derived_Type, Subtype_Kind (Ekind (Parent_Type)));
6844 end if;
6845
6846 -- If we did not have a range constraint, then set the range from the
6847 -- parent type. Otherwise, the Process_Subtype call has set the bounds.
6848
6849 if No_Constraint or else not Has_Range_Constraint (Indic) then
6850 Set_Scalar_Range (Derived_Type,
6851 Make_Range (Loc,
6852 Low_Bound => New_Copy_Tree (Type_Low_Bound (Parent_Type)),
6853 High_Bound => New_Copy_Tree (Type_High_Bound (Parent_Type))));
6854 Set_Is_Constrained (Derived_Type, Is_Constrained (Parent_Type));
6855
6856 if Has_Infinities (Parent_Type) then
6857 Set_Includes_Infinities (Scalar_Range (Derived_Type));
6858 end if;
6859
6860 Set_Is_Known_Valid (Derived_Type, Is_Known_Valid (Parent_Type));
6861 end if;
6862
6863 Set_Is_Descendant_Of_Address (Derived_Type,
6864 Is_Descendant_Of_Address (Parent_Type));
6865 Set_Is_Descendant_Of_Address (Implicit_Base,
6866 Is_Descendant_Of_Address (Parent_Type));
6867
6868 -- Set remaining type-specific fields, depending on numeric type
6869
6870 if Is_Modular_Integer_Type (Parent_Type) then
6871 Set_Modulus (Implicit_Base, Modulus (Parent_Base));
6872
6873 Set_Non_Binary_Modulus
6874 (Implicit_Base, Non_Binary_Modulus (Parent_Base));
6875
6876 Set_Is_Known_Valid
6877 (Implicit_Base, Is_Known_Valid (Parent_Base));
6878
6879 elsif Is_Floating_Point_Type (Parent_Type) then
6880
6881 -- Digits of base type is always copied from the digits value of
6882 -- the parent base type, but the digits of the derived type will
6883 -- already have been set if there was a constraint present.
6884
6885 Set_Digits_Value (Implicit_Base, Digits_Value (Parent_Base));
6886 Set_Float_Rep (Implicit_Base, Float_Rep (Parent_Base));
6887
6888 if No_Constraint then
6889 Set_Digits_Value (Derived_Type, Digits_Value (Parent_Type));
6890 end if;
6891
6892 elsif Is_Fixed_Point_Type (Parent_Type) then
6893
6894 -- Small of base type and derived type are always copied from the
6895 -- parent base type, since smalls never change. The delta of the
6896 -- base type is also copied from the parent base type. However the
6897 -- delta of the derived type will have been set already if a
6898 -- constraint was present.
6899
6900 Set_Small_Value (Derived_Type, Small_Value (Parent_Base));
6901 Set_Small_Value (Implicit_Base, Small_Value (Parent_Base));
6902 Set_Delta_Value (Implicit_Base, Delta_Value (Parent_Base));
6903
6904 if No_Constraint then
6905 Set_Delta_Value (Derived_Type, Delta_Value (Parent_Type));
6906 end if;
6907
6908 -- The scale and machine radix in the decimal case are always
6909 -- copied from the parent base type.
6910
6911 if Is_Decimal_Fixed_Point_Type (Parent_Type) then
6912 Set_Scale_Value (Derived_Type, Scale_Value (Parent_Base));
6913 Set_Scale_Value (Implicit_Base, Scale_Value (Parent_Base));
6914
6915 Set_Machine_Radix_10
6916 (Derived_Type, Machine_Radix_10 (Parent_Base));
6917 Set_Machine_Radix_10
6918 (Implicit_Base, Machine_Radix_10 (Parent_Base));
6919
6920 Set_Digits_Value (Implicit_Base, Digits_Value (Parent_Base));
6921
6922 if No_Constraint then
6923 Set_Digits_Value (Derived_Type, Digits_Value (Parent_Base));
6924
6925 else
6926 -- the analysis of the subtype_indication sets the
6927 -- digits value of the derived type.
6928
6929 null;
6930 end if;
6931 end if;
6932 end if;
6933
6934 if Is_Integer_Type (Parent_Type) then
6935 Set_Has_Shift_Operator
6936 (Implicit_Base, Has_Shift_Operator (Parent_Type));
6937 end if;
6938
6939 -- The type of the bounds is that of the parent type, and they
6940 -- must be converted to the derived type.
6941
6942 Convert_Scalar_Bounds (N, Parent_Type, Derived_Type, Loc);
6943
6944 -- The implicit_base should be frozen when the derived type is frozen,
6945 -- but note that it is used in the conversions of the bounds. For fixed
6946 -- types we delay the determination of the bounds until the proper
6947 -- freezing point. For other numeric types this is rejected by GCC, for
6948 -- reasons that are currently unclear (???), so we choose to freeze the
6949 -- implicit base now. In the case of integers and floating point types
6950 -- this is harmless because subsequent representation clauses cannot
6951 -- affect anything, but it is still baffling that we cannot use the
6952 -- same mechanism for all derived numeric types.
6953
6954 -- There is a further complication: actually some representation
6955 -- clauses can affect the implicit base type. For example, attribute
6956 -- definition clauses for stream-oriented attributes need to set the
6957 -- corresponding TSS entries on the base type, and this normally
6958 -- cannot be done after the base type is frozen, so the circuitry in
6959 -- Sem_Ch13.New_Stream_Subprogram must account for this possibility
6960 -- and not use Set_TSS in this case.
6961
6962 -- There are also consequences for the case of delayed representation
6963 -- aspects for some cases. For example, a Size aspect is delayed and
6964 -- should not be evaluated to the freeze point. This early freezing
6965 -- means that the size attribute evaluation happens too early???
6966
6967 if Is_Fixed_Point_Type (Parent_Type) then
6968 Conditional_Delay (Implicit_Base, Parent_Type);
6969 else
6970 Freeze_Before (N, Implicit_Base);
6971 end if;
6972 end Build_Derived_Numeric_Type;
6973
6974 --------------------------------
6975 -- Build_Derived_Private_Type --
6976 --------------------------------
6977
6978 procedure Build_Derived_Private_Type
6979 (N : Node_Id;
6980 Parent_Type : Entity_Id;
6981 Derived_Type : Entity_Id;
6982 Is_Completion : Boolean;
6983 Derive_Subps : Boolean := True)
6984 is
6985 Loc : constant Source_Ptr := Sloc (N);
6986 Par_Base : constant Entity_Id := Base_Type (Parent_Type);
6987 Par_Scope : constant Entity_Id := Scope (Par_Base);
6988 Full_N : constant Node_Id := New_Copy_Tree (N);
6989 Full_Der : Entity_Id := New_Copy (Derived_Type);
6990 Full_P : Entity_Id;
6991
6992 procedure Build_Full_Derivation;
6993 -- Build full derivation, i.e. derive from the full view
6994
6995 procedure Copy_And_Build;
6996 -- Copy derived type declaration, replace parent with its full view,
6997 -- and build derivation
6998
6999 ---------------------------
7000 -- Build_Full_Derivation --
7001 ---------------------------
7002
7003 procedure Build_Full_Derivation is
7004 begin
7005 -- If parent scope is not open, install the declarations
7006
7007 if not In_Open_Scopes (Par_Scope) then
7008 Install_Private_Declarations (Par_Scope);
7009 Install_Visible_Declarations (Par_Scope);
7010 Copy_And_Build;
7011 Uninstall_Declarations (Par_Scope);
7012
7013 -- If parent scope is open and in another unit, and parent has a
7014 -- completion, then the derivation is taking place in the visible
7015 -- part of a child unit. In that case retrieve the full view of
7016 -- the parent momentarily.
7017
7018 elsif not In_Same_Source_Unit (N, Parent_Type) then
7019 Full_P := Full_View (Parent_Type);
7020 Exchange_Declarations (Parent_Type);
7021 Copy_And_Build;
7022 Exchange_Declarations (Full_P);
7023
7024 -- Otherwise it is a local derivation
7025
7026 else
7027 Copy_And_Build;
7028 end if;
7029 end Build_Full_Derivation;
7030
7031 --------------------
7032 -- Copy_And_Build --
7033 --------------------
7034
7035 procedure Copy_And_Build is
7036 Full_Parent : Entity_Id := Parent_Type;
7037
7038 begin
7039 -- If the parent is itself derived from another private type,
7040 -- installing the private declarations has not affected its
7041 -- privacy status, so use its own full view explicitly.
7042
7043 if Is_Private_Type (Full_Parent)
7044 and then Present (Full_View (Full_Parent))
7045 then
7046 Full_Parent := Full_View (Full_Parent);
7047 end if;
7048
7049 -- And its underlying full view if necessary
7050
7051 if Is_Private_Type (Full_Parent)
7052 and then Present (Underlying_Full_View (Full_Parent))
7053 then
7054 Full_Parent := Underlying_Full_View (Full_Parent);
7055 end if;
7056
7057 -- For record, access and most enumeration types, derivation from
7058 -- the full view requires a fully-fledged declaration. In the other
7059 -- cases, just use an itype.
7060
7061 if Ekind (Full_Parent) in Record_Kind
7062 or else Ekind (Full_Parent) in Access_Kind
7063 or else
7064 (Ekind (Full_Parent) in Enumeration_Kind
7065 and then not Is_Standard_Character_Type (Full_Parent)
7066 and then not Is_Generic_Type (Root_Type (Full_Parent)))
7067 then
7068 -- Copy and adjust declaration to provide a completion for what
7069 -- is originally a private declaration. Indicate that full view
7070 -- is internally generated.
7071
7072 Set_Comes_From_Source (Full_N, False);
7073 Set_Comes_From_Source (Full_Der, False);
7074 Set_Parent (Full_Der, Full_N);
7075 Set_Defining_Identifier (Full_N, Full_Der);
7076
7077 -- If there are no constraints, adjust the subtype mark
7078
7079 if Nkind (Subtype_Indication (Type_Definition (Full_N))) /=
7080 N_Subtype_Indication
7081 then
7082 Set_Subtype_Indication
7083 (Type_Definition (Full_N),
7084 New_Occurrence_Of (Full_Parent, Sloc (Full_N)));
7085 end if;
7086
7087 Insert_After (N, Full_N);
7088
7089 -- Build full view of derived type from full view of parent which
7090 -- is now installed. Subprograms have been derived on the partial
7091 -- view, the completion does not derive them anew.
7092
7093 if Ekind (Full_Parent) in Record_Kind then
7094
7095 -- If parent type is tagged, the completion inherits the proper
7096 -- primitive operations.
7097
7098 if Is_Tagged_Type (Parent_Type) then
7099 Build_Derived_Record_Type
7100 (Full_N, Full_Parent, Full_Der, Derive_Subps);
7101 else
7102 Build_Derived_Record_Type
7103 (Full_N, Full_Parent, Full_Der, Derive_Subps => False);
7104 end if;
7105
7106 else
7107 Build_Derived_Type
7108 (Full_N, Full_Parent, Full_Der,
7109 Is_Completion => False, Derive_Subps => False);
7110 end if;
7111
7112 -- The full declaration has been introduced into the tree and
7113 -- processed in the step above. It should not be analyzed again
7114 -- (when encountered later in the current list of declarations)
7115 -- to prevent spurious name conflicts. The full entity remains
7116 -- invisible.
7117
7118 Set_Analyzed (Full_N);
7119
7120 else
7121 Full_Der :=
7122 Make_Defining_Identifier (Sloc (Derived_Type),
7123 Chars => Chars (Derived_Type));
7124 Set_Is_Itype (Full_Der);
7125 Set_Associated_Node_For_Itype (Full_Der, N);
7126 Set_Parent (Full_Der, N);
7127 Build_Derived_Type
7128 (N, Full_Parent, Full_Der,
7129 Is_Completion => False, Derive_Subps => False);
7130 end if;
7131
7132 Set_Has_Private_Declaration (Full_Der);
7133 Set_Has_Private_Declaration (Derived_Type);
7134
7135 Set_Scope (Full_Der, Scope (Derived_Type));
7136 Set_Is_First_Subtype (Full_Der, Is_First_Subtype (Derived_Type));
7137 Set_Has_Size_Clause (Full_Der, False);
7138 Set_Has_Alignment_Clause (Full_Der, False);
7139 Set_Has_Delayed_Freeze (Full_Der);
7140 Set_Is_Frozen (Full_Der, False);
7141 Set_Freeze_Node (Full_Der, Empty);
7142 Set_Depends_On_Private (Full_Der, Has_Private_Component (Full_Der));
7143 Set_Is_Public (Full_Der, Is_Public (Derived_Type));
7144
7145 -- The convention on the base type may be set in the private part
7146 -- and not propagated to the subtype until later, so we obtain the
7147 -- convention from the base type of the parent.
7148
7149 Set_Convention (Full_Der, Convention (Base_Type (Full_Parent)));
7150 end Copy_And_Build;
7151
7152 -- Start of processing for Build_Derived_Private_Type
7153
7154 begin
7155 if Is_Tagged_Type (Parent_Type) then
7156 Full_P := Full_View (Parent_Type);
7157
7158 -- A type extension of a type with unknown discriminants is an
7159 -- indefinite type that the back-end cannot handle directly.
7160 -- We treat it as a private type, and build a completion that is
7161 -- derived from the full view of the parent, and hopefully has
7162 -- known discriminants.
7163
7164 -- If the full view of the parent type has an underlying record view,
7165 -- use it to generate the underlying record view of this derived type
7166 -- (required for chains of derivations with unknown discriminants).
7167
7168 -- Minor optimization: we avoid the generation of useless underlying
7169 -- record view entities if the private type declaration has unknown
7170 -- discriminants but its corresponding full view has no
7171 -- discriminants.
7172
7173 if Has_Unknown_Discriminants (Parent_Type)
7174 and then Present (Full_P)
7175 and then (Has_Discriminants (Full_P)
7176 or else Present (Underlying_Record_View (Full_P)))
7177 and then not In_Open_Scopes (Par_Scope)
7178 and then Expander_Active
7179 then
7180 declare
7181 Full_Der : constant Entity_Id := Make_Temporary (Loc, 'T');
7182 New_Ext : constant Node_Id :=
7183 Copy_Separate_Tree
7184 (Record_Extension_Part (Type_Definition (N)));
7185 Decl : Node_Id;
7186
7187 begin
7188 Build_Derived_Record_Type
7189 (N, Parent_Type, Derived_Type, Derive_Subps);
7190
7191 -- Build anonymous completion, as a derivation from the full
7192 -- view of the parent. This is not a completion in the usual
7193 -- sense, because the current type is not private.
7194
7195 Decl :=
7196 Make_Full_Type_Declaration (Loc,
7197 Defining_Identifier => Full_Der,
7198 Type_Definition =>
7199 Make_Derived_Type_Definition (Loc,
7200 Subtype_Indication =>
7201 New_Copy_Tree
7202 (Subtype_Indication (Type_Definition (N))),
7203 Record_Extension_Part => New_Ext));
7204
7205 -- If the parent type has an underlying record view, use it
7206 -- here to build the new underlying record view.
7207
7208 if Present (Underlying_Record_View (Full_P)) then
7209 pragma Assert
7210 (Nkind (Subtype_Indication (Type_Definition (Decl)))
7211 = N_Identifier);
7212 Set_Entity (Subtype_Indication (Type_Definition (Decl)),
7213 Underlying_Record_View (Full_P));
7214 end if;
7215
7216 Install_Private_Declarations (Par_Scope);
7217 Install_Visible_Declarations (Par_Scope);
7218 Insert_Before (N, Decl);
7219
7220 -- Mark entity as an underlying record view before analysis,
7221 -- to avoid generating the list of its primitive operations
7222 -- (which is not really required for this entity) and thus
7223 -- prevent spurious errors associated with missing overriding
7224 -- of abstract primitives (overridden only for Derived_Type).
7225
7226 Set_Ekind (Full_Der, E_Record_Type);
7227 Set_Is_Underlying_Record_View (Full_Der);
7228 Set_Default_SSO (Full_Der);
7229
7230 Analyze (Decl);
7231
7232 pragma Assert (Has_Discriminants (Full_Der)
7233 and then not Has_Unknown_Discriminants (Full_Der));
7234
7235 Uninstall_Declarations (Par_Scope);
7236
7237 -- Freeze the underlying record view, to prevent generation of
7238 -- useless dispatching information, which is simply shared with
7239 -- the real derived type.
7240
7241 Set_Is_Frozen (Full_Der);
7242
7243 -- If the derived type has access discriminants, create
7244 -- references to their anonymous types now, to prevent
7245 -- back-end problems when their first use is in generated
7246 -- bodies of primitives.
7247
7248 declare
7249 E : Entity_Id;
7250
7251 begin
7252 E := First_Entity (Full_Der);
7253
7254 while Present (E) loop
7255 if Ekind (E) = E_Discriminant
7256 and then Ekind (Etype (E)) = E_Anonymous_Access_Type
7257 then
7258 Build_Itype_Reference (Etype (E), Decl);
7259 end if;
7260
7261 Next_Entity (E);
7262 end loop;
7263 end;
7264
7265 -- Set up links between real entity and underlying record view
7266
7267 Set_Underlying_Record_View (Derived_Type, Base_Type (Full_Der));
7268 Set_Underlying_Record_View (Base_Type (Full_Der), Derived_Type);
7269 end;
7270
7271 -- If discriminants are known, build derived record
7272
7273 else
7274 Build_Derived_Record_Type
7275 (N, Parent_Type, Derived_Type, Derive_Subps);
7276 end if;
7277
7278 return;
7279
7280 elsif Has_Discriminants (Parent_Type) then
7281
7282 -- Build partial view of derived type from partial view of parent.
7283 -- This must be done before building the full derivation because the
7284 -- second derivation will modify the discriminants of the first and
7285 -- the discriminants are chained with the rest of the components in
7286 -- the full derivation.
7287
7288 Build_Derived_Record_Type
7289 (N, Parent_Type, Derived_Type, Derive_Subps);
7290
7291 -- Build the full derivation if this is not the anonymous derived
7292 -- base type created by Build_Derived_Record_Type in the constrained
7293 -- case (see point 5. of its head comment) since we build it for the
7294 -- derived subtype. And skip it for protected types altogether, as
7295 -- gigi does not use these types directly.
7296
7297 if Present (Full_View (Parent_Type))
7298 and then not Is_Itype (Derived_Type)
7299 and then not (Ekind (Full_View (Parent_Type)) in Protected_Kind)
7300 then
7301 declare
7302 Der_Base : constant Entity_Id := Base_Type (Derived_Type);
7303 Discr : Entity_Id;
7304 Last_Discr : Entity_Id;
7305
7306 begin
7307 -- If this is not a completion, construct the implicit full
7308 -- view by deriving from the full view of the parent type.
7309 -- But if this is a completion, the derived private type
7310 -- being built is a full view and the full derivation can
7311 -- only be its underlying full view.
7312
7313 Build_Full_Derivation;
7314
7315 if not Is_Completion then
7316 Set_Full_View (Derived_Type, Full_Der);
7317 else
7318 Set_Underlying_Full_View (Derived_Type, Full_Der);
7319 end if;
7320
7321 if not Is_Base_Type (Derived_Type) then
7322 Set_Full_View (Der_Base, Base_Type (Full_Der));
7323 end if;
7324
7325 -- Copy the discriminant list from full view to the partial
7326 -- view (base type and its subtype). Gigi requires that the
7327 -- partial and full views have the same discriminants.
7328
7329 -- Note that since the partial view points to discriminants
7330 -- in the full view, their scope will be that of the full
7331 -- view. This might cause some front end problems and need
7332 -- adjustment???
7333
7334 Discr := First_Discriminant (Base_Type (Full_Der));
7335 Set_First_Entity (Der_Base, Discr);
7336
7337 loop
7338 Last_Discr := Discr;
7339 Next_Discriminant (Discr);
7340 exit when No (Discr);
7341 end loop;
7342
7343 Set_Last_Entity (Der_Base, Last_Discr);
7344 Set_First_Entity (Derived_Type, First_Entity (Der_Base));
7345 Set_Last_Entity (Derived_Type, Last_Entity (Der_Base));
7346
7347 Set_Stored_Constraint
7348 (Full_Der, Stored_Constraint (Derived_Type));
7349 end;
7350 end if;
7351
7352 elsif Present (Full_View (Parent_Type))
7353 and then Has_Discriminants (Full_View (Parent_Type))
7354 then
7355 if Has_Unknown_Discriminants (Parent_Type)
7356 and then Nkind (Subtype_Indication (Type_Definition (N))) =
7357 N_Subtype_Indication
7358 then
7359 Error_Msg_N
7360 ("cannot constrain type with unknown discriminants",
7361 Subtype_Indication (Type_Definition (N)));
7362 return;
7363 end if;
7364
7365 -- If this is not a completion, construct the implicit full view by
7366 -- deriving from the full view of the parent type. But if this is a
7367 -- completion, the derived private type being built is a full view
7368 -- and the full derivation can only be its underlying full view.
7369
7370 Build_Full_Derivation;
7371
7372 if not Is_Completion then
7373 Set_Full_View (Derived_Type, Full_Der);
7374 else
7375 Set_Underlying_Full_View (Derived_Type, Full_Der);
7376 end if;
7377
7378 -- In any case, the primitive operations are inherited from the
7379 -- parent type, not from the internal full view.
7380
7381 Set_Etype (Base_Type (Derived_Type), Base_Type (Parent_Type));
7382
7383 if Derive_Subps then
7384 Derive_Subprograms (Parent_Type, Derived_Type);
7385 end if;
7386
7387 Set_Stored_Constraint (Derived_Type, No_Elist);
7388 Set_Is_Constrained
7389 (Derived_Type, Is_Constrained (Full_View (Parent_Type)));
7390
7391 else
7392 -- Untagged type, No discriminants on either view
7393
7394 if Nkind (Subtype_Indication (Type_Definition (N))) =
7395 N_Subtype_Indication
7396 then
7397 Error_Msg_N
7398 ("illegal constraint on type without discriminants", N);
7399 end if;
7400
7401 if Present (Discriminant_Specifications (N))
7402 and then Present (Full_View (Parent_Type))
7403 and then not Is_Tagged_Type (Full_View (Parent_Type))
7404 then
7405 Error_Msg_N ("cannot add discriminants to untagged type", N);
7406 end if;
7407
7408 Set_Stored_Constraint (Derived_Type, No_Elist);
7409 Set_Is_Constrained (Derived_Type, Is_Constrained (Parent_Type));
7410 Set_Is_Controlled (Derived_Type, Is_Controlled (Parent_Type));
7411 Set_Disable_Controlled (Derived_Type, Disable_Controlled
7412 (Parent_Type));
7413 Set_Has_Controlled_Component
7414 (Derived_Type, Has_Controlled_Component
7415 (Parent_Type));
7416
7417 -- Direct controlled types do not inherit Finalize_Storage_Only flag
7418
7419 if not Is_Controlled_Active (Parent_Type) then
7420 Set_Finalize_Storage_Only
7421 (Base_Type (Derived_Type), Finalize_Storage_Only (Parent_Type));
7422 end if;
7423
7424 -- If this is not a completion, construct the implicit full view by
7425 -- deriving from the full view of the parent type.
7426
7427 -- ??? If the parent is untagged private and its completion is
7428 -- tagged, this mechanism will not work because we cannot derive from
7429 -- the tagged full view unless we have an extension.
7430
7431 if Present (Full_View (Parent_Type))
7432 and then not Is_Tagged_Type (Full_View (Parent_Type))
7433 and then not Is_Completion
7434 then
7435 Build_Full_Derivation;
7436 Set_Full_View (Derived_Type, Full_Der);
7437 end if;
7438 end if;
7439
7440 Set_Has_Unknown_Discriminants (Derived_Type,
7441 Has_Unknown_Discriminants (Parent_Type));
7442
7443 if Is_Private_Type (Derived_Type) then
7444 Set_Private_Dependents (Derived_Type, New_Elmt_List);
7445 end if;
7446
7447 -- If the parent base type is in scope, add the derived type to its
7448 -- list of private dependents, because its full view may become
7449 -- visible subsequently (in a nested private part, a body, or in a
7450 -- further child unit).
7451
7452 if Is_Private_Type (Par_Base) and then In_Open_Scopes (Par_Scope) then
7453 Append_Elmt (Derived_Type, Private_Dependents (Parent_Type));
7454
7455 -- Check for unusual case where a type completed by a private
7456 -- derivation occurs within a package nested in a child unit, and
7457 -- the parent is declared in an ancestor.
7458
7459 if Is_Child_Unit (Scope (Current_Scope))
7460 and then Is_Completion
7461 and then In_Private_Part (Current_Scope)
7462 and then Scope (Parent_Type) /= Current_Scope
7463
7464 -- Note that if the parent has a completion in the private part,
7465 -- (which is itself a derivation from some other private type)
7466 -- it is that completion that is visible, there is no full view
7467 -- available, and no special processing is needed.
7468
7469 and then Present (Full_View (Parent_Type))
7470 then
7471 -- In this case, the full view of the parent type will become
7472 -- visible in the body of the enclosing child, and only then will
7473 -- the current type be possibly non-private. Build an underlying
7474 -- full view that will be installed when the enclosing child body
7475 -- is compiled.
7476
7477 if Present (Underlying_Full_View (Derived_Type)) then
7478 Full_Der := Underlying_Full_View (Derived_Type);
7479 else
7480 Build_Full_Derivation;
7481 Set_Underlying_Full_View (Derived_Type, Full_Der);
7482 end if;
7483
7484 -- The full view will be used to swap entities on entry/exit to
7485 -- the body, and must appear in the entity list for the package.
7486
7487 Append_Entity (Full_Der, Scope (Derived_Type));
7488 end if;
7489 end if;
7490 end Build_Derived_Private_Type;
7491
7492 -------------------------------
7493 -- Build_Derived_Record_Type --
7494 -------------------------------
7495
7496 -- 1. INTRODUCTION
7497
7498 -- Ideally we would like to use the same model of type derivation for
7499 -- tagged and untagged record types. Unfortunately this is not quite
7500 -- possible because the semantics of representation clauses is different
7501 -- for tagged and untagged records under inheritance. Consider the
7502 -- following:
7503
7504 -- type R (...) is [tagged] record ... end record;
7505 -- type T (...) is new R (...) [with ...];
7506
7507 -- The representation clauses for T can specify a completely different
7508 -- record layout from R's. Hence the same component can be placed in two
7509 -- very different positions in objects of type T and R. If R and T are
7510 -- tagged types, representation clauses for T can only specify the layout
7511 -- of non inherited components, thus components that are common in R and T
7512 -- have the same position in objects of type R and T.
7513
7514 -- This has two implications. The first is that the entire tree for R's
7515 -- declaration needs to be copied for T in the untagged case, so that T
7516 -- can be viewed as a record type of its own with its own representation
7517 -- clauses. The second implication is the way we handle discriminants.
7518 -- Specifically, in the untagged case we need a way to communicate to Gigi
7519 -- what are the real discriminants in the record, while for the semantics
7520 -- we need to consider those introduced by the user to rename the
7521 -- discriminants in the parent type. This is handled by introducing the
7522 -- notion of stored discriminants. See below for more.
7523
7524 -- Fortunately the way regular components are inherited can be handled in
7525 -- the same way in tagged and untagged types.
7526
7527 -- To complicate things a bit more the private view of a private extension
7528 -- cannot be handled in the same way as the full view (for one thing the
7529 -- semantic rules are somewhat different). We will explain what differs
7530 -- below.
7531
7532 -- 2. DISCRIMINANTS UNDER INHERITANCE
7533
7534 -- The semantic rules governing the discriminants of derived types are
7535 -- quite subtle.
7536
7537 -- type Derived_Type_Name [KNOWN_DISCRIMINANT_PART] is new
7538 -- [abstract] Parent_Type_Name [CONSTRAINT] [RECORD_EXTENSION_PART]
7539
7540 -- If parent type has discriminants, then the discriminants that are
7541 -- declared in the derived type are [3.4 (11)]:
7542
7543 -- o The discriminants specified by a new KNOWN_DISCRIMINANT_PART, if
7544 -- there is one;
7545
7546 -- o Otherwise, each discriminant of the parent type (implicitly declared
7547 -- in the same order with the same specifications). In this case, the
7548 -- discriminants are said to be "inherited", or if unknown in the parent
7549 -- are also unknown in the derived type.
7550
7551 -- Furthermore if a KNOWN_DISCRIMINANT_PART is provided, then [3.7(13-18)]:
7552
7553 -- o The parent subtype must be constrained;
7554
7555 -- o If the parent type is not a tagged type, then each discriminant of
7556 -- the derived type must be used in the constraint defining a parent
7557 -- subtype. [Implementation note: This ensures that the new discriminant
7558 -- can share storage with an existing discriminant.]
7559
7560 -- For the derived type each discriminant of the parent type is either
7561 -- inherited, constrained to equal some new discriminant of the derived
7562 -- type, or constrained to the value of an expression.
7563
7564 -- When inherited or constrained to equal some new discriminant, the
7565 -- parent discriminant and the discriminant of the derived type are said
7566 -- to "correspond".
7567
7568 -- If a discriminant of the parent type is constrained to a specific value
7569 -- in the derived type definition, then the discriminant is said to be
7570 -- "specified" by that derived type definition.
7571
7572 -- 3. DISCRIMINANTS IN DERIVED UNTAGGED RECORD TYPES
7573
7574 -- We have spoken about stored discriminants in point 1 (introduction)
7575 -- above. There are two sort of stored discriminants: implicit and
7576 -- explicit. As long as the derived type inherits the same discriminants as
7577 -- the root record type, stored discriminants are the same as regular
7578 -- discriminants, and are said to be implicit. However, if any discriminant
7579 -- in the root type was renamed in the derived type, then the derived
7580 -- type will contain explicit stored discriminants. Explicit stored
7581 -- discriminants are discriminants in addition to the semantically visible
7582 -- discriminants defined for the derived type. Stored discriminants are
7583 -- used by Gigi to figure out what are the physical discriminants in
7584 -- objects of the derived type (see precise definition in einfo.ads).
7585 -- As an example, consider the following:
7586
7587 -- type R (D1, D2, D3 : Int) is record ... end record;
7588 -- type T1 is new R;
7589 -- type T2 (X1, X2: Int) is new T1 (X2, 88, X1);
7590 -- type T3 is new T2;
7591 -- type T4 (Y : Int) is new T3 (Y, 99);
7592
7593 -- The following table summarizes the discriminants and stored
7594 -- discriminants in R and T1 through T4.
7595
7596 -- Type Discrim Stored Discrim Comment
7597 -- R (D1, D2, D3) (D1, D2, D3) Girder discrims implicit in R
7598 -- T1 (D1, D2, D3) (D1, D2, D3) Girder discrims implicit in T1
7599 -- T2 (X1, X2) (D1, D2, D3) Girder discrims EXPLICIT in T2
7600 -- T3 (X1, X2) (D1, D2, D3) Girder discrims EXPLICIT in T3
7601 -- T4 (Y) (D1, D2, D3) Girder discrims EXPLICIT in T4
7602
7603 -- Field Corresponding_Discriminant (abbreviated CD below) allows us to
7604 -- find the corresponding discriminant in the parent type, while
7605 -- Original_Record_Component (abbreviated ORC below), the actual physical
7606 -- component that is renamed. Finally the field Is_Completely_Hidden
7607 -- (abbreviated ICH below) is set for all explicit stored discriminants
7608 -- (see einfo.ads for more info). For the above example this gives:
7609
7610 -- Discrim CD ORC ICH
7611 -- ^^^^^^^ ^^ ^^^ ^^^
7612 -- D1 in R empty itself no
7613 -- D2 in R empty itself no
7614 -- D3 in R empty itself no
7615
7616 -- D1 in T1 D1 in R itself no
7617 -- D2 in T1 D2 in R itself no
7618 -- D3 in T1 D3 in R itself no
7619
7620 -- X1 in T2 D3 in T1 D3 in T2 no
7621 -- X2 in T2 D1 in T1 D1 in T2 no
7622 -- D1 in T2 empty itself yes
7623 -- D2 in T2 empty itself yes
7624 -- D3 in T2 empty itself yes
7625
7626 -- X1 in T3 X1 in T2 D3 in T3 no
7627 -- X2 in T3 X2 in T2 D1 in T3 no
7628 -- D1 in T3 empty itself yes
7629 -- D2 in T3 empty itself yes
7630 -- D3 in T3 empty itself yes
7631
7632 -- Y in T4 X1 in T3 D3 in T3 no
7633 -- D1 in T3 empty itself yes
7634 -- D2 in T3 empty itself yes
7635 -- D3 in T3 empty itself yes
7636
7637 -- 4. DISCRIMINANTS IN DERIVED TAGGED RECORD TYPES
7638
7639 -- Type derivation for tagged types is fairly straightforward. If no
7640 -- discriminants are specified by the derived type, these are inherited
7641 -- from the parent. No explicit stored discriminants are ever necessary.
7642 -- The only manipulation that is done to the tree is that of adding a
7643 -- _parent field with parent type and constrained to the same constraint
7644 -- specified for the parent in the derived type definition. For instance:
7645
7646 -- type R (D1, D2, D3 : Int) is tagged record ... end record;
7647 -- type T1 is new R with null record;
7648 -- type T2 (X1, X2: Int) is new T1 (X2, 88, X1) with null record;
7649
7650 -- are changed into:
7651
7652 -- type T1 (D1, D2, D3 : Int) is new R (D1, D2, D3) with record
7653 -- _parent : R (D1, D2, D3);
7654 -- end record;
7655
7656 -- type T2 (X1, X2: Int) is new T1 (X2, 88, X1) with record
7657 -- _parent : T1 (X2, 88, X1);
7658 -- end record;
7659
7660 -- The discriminants actually present in R, T1 and T2 as well as their CD,
7661 -- ORC and ICH fields are:
7662
7663 -- Discrim CD ORC ICH
7664 -- ^^^^^^^ ^^ ^^^ ^^^
7665 -- D1 in R empty itself no
7666 -- D2 in R empty itself no
7667 -- D3 in R empty itself no
7668
7669 -- D1 in T1 D1 in R D1 in R no
7670 -- D2 in T1 D2 in R D2 in R no
7671 -- D3 in T1 D3 in R D3 in R no
7672
7673 -- X1 in T2 D3 in T1 D3 in R no
7674 -- X2 in T2 D1 in T1 D1 in R no
7675
7676 -- 5. FIRST TRANSFORMATION FOR DERIVED RECORDS
7677 --
7678 -- Regardless of whether we dealing with a tagged or untagged type
7679 -- we will transform all derived type declarations of the form
7680 --
7681 -- type T is new R (...) [with ...];
7682 -- or
7683 -- subtype S is R (...);
7684 -- type T is new S [with ...];
7685 -- into
7686 -- type BT is new R [with ...];
7687 -- subtype T is BT (...);
7688 --
7689 -- That is, the base derived type is constrained only if it has no
7690 -- discriminants. The reason for doing this is that GNAT's semantic model
7691 -- assumes that a base type with discriminants is unconstrained.
7692 --
7693 -- Note that, strictly speaking, the above transformation is not always
7694 -- correct. Consider for instance the following excerpt from ACVC b34011a:
7695 --
7696 -- procedure B34011A is
7697 -- type REC (D : integer := 0) is record
7698 -- I : Integer;
7699 -- end record;
7700
7701 -- package P is
7702 -- type T6 is new Rec;
7703 -- function F return T6;
7704 -- end P;
7705
7706 -- use P;
7707 -- package Q6 is
7708 -- type U is new T6 (Q6.F.I); -- ERROR: Q6.F.
7709 -- end Q6;
7710 --
7711 -- The definition of Q6.U is illegal. However transforming Q6.U into
7712
7713 -- type BaseU is new T6;
7714 -- subtype U is BaseU (Q6.F.I)
7715
7716 -- turns U into a legal subtype, which is incorrect. To avoid this problem
7717 -- we always analyze the constraint (in this case (Q6.F.I)) before applying
7718 -- the transformation described above.
7719
7720 -- There is another instance where the above transformation is incorrect.
7721 -- Consider:
7722
7723 -- package Pack is
7724 -- type Base (D : Integer) is tagged null record;
7725 -- procedure P (X : Base);
7726
7727 -- type Der is new Base (2) with null record;
7728 -- procedure P (X : Der);
7729 -- end Pack;
7730
7731 -- Then the above transformation turns this into
7732
7733 -- type Der_Base is new Base with null record;
7734 -- -- procedure P (X : Base) is implicitly inherited here
7735 -- -- as procedure P (X : Der_Base).
7736
7737 -- subtype Der is Der_Base (2);
7738 -- procedure P (X : Der);
7739 -- -- The overriding of P (X : Der_Base) is illegal since we
7740 -- -- have a parameter conformance problem.
7741
7742 -- To get around this problem, after having semantically processed Der_Base
7743 -- and the rewritten subtype declaration for Der, we copy Der_Base field
7744 -- Discriminant_Constraint from Der so that when parameter conformance is
7745 -- checked when P is overridden, no semantic errors are flagged.
7746
7747 -- 6. SECOND TRANSFORMATION FOR DERIVED RECORDS
7748
7749 -- Regardless of whether we are dealing with a tagged or untagged type
7750 -- we will transform all derived type declarations of the form
7751
7752 -- type R (D1, .., Dn : ...) is [tagged] record ...;
7753 -- type T is new R [with ...];
7754 -- into
7755 -- type T (D1, .., Dn : ...) is new R (D1, .., Dn) [with ...];
7756
7757 -- The reason for such transformation is that it allows us to implement a
7758 -- very clean form of component inheritance as explained below.
7759
7760 -- Note that this transformation is not achieved by direct tree rewriting
7761 -- and manipulation, but rather by redoing the semantic actions that the
7762 -- above transformation will entail. This is done directly in routine
7763 -- Inherit_Components.
7764
7765 -- 7. TYPE DERIVATION AND COMPONENT INHERITANCE
7766
7767 -- In both tagged and untagged derived types, regular non discriminant
7768 -- components are inherited in the derived type from the parent type. In
7769 -- the absence of discriminants component, inheritance is straightforward
7770 -- as components can simply be copied from the parent.
7771
7772 -- If the parent has discriminants, inheriting components constrained with
7773 -- these discriminants requires caution. Consider the following example:
7774
7775 -- type R (D1, D2 : Positive) is [tagged] record
7776 -- S : String (D1 .. D2);
7777 -- end record;
7778
7779 -- type T1 is new R [with null record];
7780 -- type T2 (X : positive) is new R (1, X) [with null record];
7781
7782 -- As explained in 6. above, T1 is rewritten as
7783 -- type T1 (D1, D2 : Positive) is new R (D1, D2) [with null record];
7784 -- which makes the treatment for T1 and T2 identical.
7785
7786 -- What we want when inheriting S, is that references to D1 and D2 in R are
7787 -- replaced with references to their correct constraints, i.e. D1 and D2 in
7788 -- T1 and 1 and X in T2. So all R's discriminant references are replaced
7789 -- with either discriminant references in the derived type or expressions.
7790 -- This replacement is achieved as follows: before inheriting R's
7791 -- components, a subtype R (D1, D2) for T1 (resp. R (1, X) for T2) is
7792 -- created in the scope of T1 (resp. scope of T2) so that discriminants D1
7793 -- and D2 of T1 are visible (resp. discriminant X of T2 is visible).
7794 -- For T2, for instance, this has the effect of replacing String (D1 .. D2)
7795 -- by String (1 .. X).
7796
7797 -- 8. TYPE DERIVATION IN PRIVATE TYPE EXTENSIONS
7798
7799 -- We explain here the rules governing private type extensions relevant to
7800 -- type derivation. These rules are explained on the following example:
7801
7802 -- type D [(...)] is new A [(...)] with private; <-- partial view
7803 -- type D [(...)] is new P [(...)] with null record; <-- full view
7804
7805 -- Type A is called the ancestor subtype of the private extension.
7806 -- Type P is the parent type of the full view of the private extension. It
7807 -- must be A or a type derived from A.
7808
7809 -- The rules concerning the discriminants of private type extensions are
7810 -- [7.3(10-13)]:
7811
7812 -- o If a private extension inherits known discriminants from the ancestor
7813 -- subtype, then the full view must also inherit its discriminants from
7814 -- the ancestor subtype and the parent subtype of the full view must be
7815 -- constrained if and only if the ancestor subtype is constrained.
7816
7817 -- o If a partial view has unknown discriminants, then the full view may
7818 -- define a definite or an indefinite subtype, with or without
7819 -- discriminants.
7820
7821 -- o If a partial view has neither known nor unknown discriminants, then
7822 -- the full view must define a definite subtype.
7823
7824 -- o If the ancestor subtype of a private extension has constrained
7825 -- discriminants, then the parent subtype of the full view must impose a
7826 -- statically matching constraint on those discriminants.
7827
7828 -- This means that only the following forms of private extensions are
7829 -- allowed:
7830
7831 -- type D is new A with private; <-- partial view
7832 -- type D is new P with null record; <-- full view
7833
7834 -- If A has no discriminants than P has no discriminants, otherwise P must
7835 -- inherit A's discriminants.
7836
7837 -- type D is new A (...) with private; <-- partial view
7838 -- type D is new P (:::) with null record; <-- full view
7839
7840 -- P must inherit A's discriminants and (...) and (:::) must statically
7841 -- match.
7842
7843 -- subtype A is R (...);
7844 -- type D is new A with private; <-- partial view
7845 -- type D is new P with null record; <-- full view
7846
7847 -- P must have inherited R's discriminants and must be derived from A or
7848 -- any of its subtypes.
7849
7850 -- type D (..) is new A with private; <-- partial view
7851 -- type D (..) is new P [(:::)] with null record; <-- full view
7852
7853 -- No specific constraints on P's discriminants or constraint (:::).
7854 -- Note that A can be unconstrained, but the parent subtype P must either
7855 -- be constrained or (:::) must be present.
7856
7857 -- type D (..) is new A [(...)] with private; <-- partial view
7858 -- type D (..) is new P [(:::)] with null record; <-- full view
7859
7860 -- P's constraints on A's discriminants must statically match those
7861 -- imposed by (...).
7862
7863 -- 9. IMPLEMENTATION OF TYPE DERIVATION FOR PRIVATE EXTENSIONS
7864
7865 -- The full view of a private extension is handled exactly as described
7866 -- above. The model chose for the private view of a private extension is
7867 -- the same for what concerns discriminants (i.e. they receive the same
7868 -- treatment as in the tagged case). However, the private view of the
7869 -- private extension always inherits the components of the parent base,
7870 -- without replacing any discriminant reference. Strictly speaking this is
7871 -- incorrect. However, Gigi never uses this view to generate code so this
7872 -- is a purely semantic issue. In theory, a set of transformations similar
7873 -- to those given in 5. and 6. above could be applied to private views of
7874 -- private extensions to have the same model of component inheritance as
7875 -- for non private extensions. However, this is not done because it would
7876 -- further complicate private type processing. Semantically speaking, this
7877 -- leaves us in an uncomfortable situation. As an example consider:
7878
7879 -- package Pack is
7880 -- type R (D : integer) is tagged record
7881 -- S : String (1 .. D);
7882 -- end record;
7883 -- procedure P (X : R);
7884 -- type T is new R (1) with private;
7885 -- private
7886 -- type T is new R (1) with null record;
7887 -- end;
7888
7889 -- This is transformed into:
7890
7891 -- package Pack is
7892 -- type R (D : integer) is tagged record
7893 -- S : String (1 .. D);
7894 -- end record;
7895 -- procedure P (X : R);
7896 -- type T is new R (1) with private;
7897 -- private
7898 -- type BaseT is new R with null record;
7899 -- subtype T is BaseT (1);
7900 -- end;
7901
7902 -- (strictly speaking the above is incorrect Ada)
7903
7904 -- From the semantic standpoint the private view of private extension T
7905 -- should be flagged as constrained since one can clearly have
7906 --
7907 -- Obj : T;
7908 --
7909 -- in a unit withing Pack. However, when deriving subprograms for the
7910 -- private view of private extension T, T must be seen as unconstrained
7911 -- since T has discriminants (this is a constraint of the current
7912 -- subprogram derivation model). Thus, when processing the private view of
7913 -- a private extension such as T, we first mark T as unconstrained, we
7914 -- process it, we perform program derivation and just before returning from
7915 -- Build_Derived_Record_Type we mark T as constrained.
7916
7917 -- ??? Are there are other uncomfortable cases that we will have to
7918 -- deal with.
7919
7920 -- 10. RECORD_TYPE_WITH_PRIVATE complications
7921
7922 -- Types that are derived from a visible record type and have a private
7923 -- extension present other peculiarities. They behave mostly like private
7924 -- types, but if they have primitive operations defined, these will not
7925 -- have the proper signatures for further inheritance, because other
7926 -- primitive operations will use the implicit base that we define for
7927 -- private derivations below. This affect subprogram inheritance (see
7928 -- Derive_Subprograms for details). We also derive the implicit base from
7929 -- the base type of the full view, so that the implicit base is a record
7930 -- type and not another private type, This avoids infinite loops.
7931
7932 procedure Build_Derived_Record_Type
7933 (N : Node_Id;
7934 Parent_Type : Entity_Id;
7935 Derived_Type : Entity_Id;
7936 Derive_Subps : Boolean := True)
7937 is
7938 Discriminant_Specs : constant Boolean :=
7939 Present (Discriminant_Specifications (N));
7940 Is_Tagged : constant Boolean := Is_Tagged_Type (Parent_Type);
7941 Loc : constant Source_Ptr := Sloc (N);
7942 Private_Extension : constant Boolean :=
7943 Nkind (N) = N_Private_Extension_Declaration;
7944 Assoc_List : Elist_Id;
7945 Constraint_Present : Boolean;
7946 Constrs : Elist_Id;
7947 Discrim : Entity_Id;
7948 Indic : Node_Id;
7949 Inherit_Discrims : Boolean := False;
7950 Last_Discrim : Entity_Id;
7951 New_Base : Entity_Id;
7952 New_Decl : Node_Id;
7953 New_Discrs : Elist_Id;
7954 New_Indic : Node_Id;
7955 Parent_Base : Entity_Id;
7956 Save_Etype : Entity_Id;
7957 Save_Discr_Constr : Elist_Id;
7958 Save_Next_Entity : Entity_Id;
7959 Type_Def : Node_Id;
7960
7961 Discs : Elist_Id := New_Elmt_List;
7962 -- An empty Discs list means that there were no constraints in the
7963 -- subtype indication or that there was an error processing it.
7964
7965 begin
7966 if Ekind (Parent_Type) = E_Record_Type_With_Private
7967 and then Present (Full_View (Parent_Type))
7968 and then Has_Discriminants (Parent_Type)
7969 then
7970 Parent_Base := Base_Type (Full_View (Parent_Type));
7971 else
7972 Parent_Base := Base_Type (Parent_Type);
7973 end if;
7974
7975 -- AI05-0115 : if this is a derivation from a private type in some
7976 -- other scope that may lead to invisible components for the derived
7977 -- type, mark it accordingly.
7978
7979 if Is_Private_Type (Parent_Type) then
7980 if Scope (Parent_Type) = Scope (Derived_Type) then
7981 null;
7982
7983 elsif In_Open_Scopes (Scope (Parent_Type))
7984 and then In_Private_Part (Scope (Parent_Type))
7985 then
7986 null;
7987
7988 else
7989 Set_Has_Private_Ancestor (Derived_Type);
7990 end if;
7991
7992 else
7993 Set_Has_Private_Ancestor
7994 (Derived_Type, Has_Private_Ancestor (Parent_Type));
7995 end if;
7996
7997 -- Before we start the previously documented transformations, here is
7998 -- little fix for size and alignment of tagged types. Normally when we
7999 -- derive type D from type P, we copy the size and alignment of P as the
8000 -- default for D, and in the absence of explicit representation clauses
8001 -- for D, the size and alignment are indeed the same as the parent.
8002
8003 -- But this is wrong for tagged types, since fields may be added, and
8004 -- the default size may need to be larger, and the default alignment may
8005 -- need to be larger.
8006
8007 -- We therefore reset the size and alignment fields in the tagged case.
8008 -- Note that the size and alignment will in any case be at least as
8009 -- large as the parent type (since the derived type has a copy of the
8010 -- parent type in the _parent field)
8011
8012 -- The type is also marked as being tagged here, which is needed when
8013 -- processing components with a self-referential anonymous access type
8014 -- in the call to Check_Anonymous_Access_Components below. Note that
8015 -- this flag is also set later on for completeness.
8016
8017 if Is_Tagged then
8018 Set_Is_Tagged_Type (Derived_Type);
8019 Init_Size_Align (Derived_Type);
8020 end if;
8021
8022 -- STEP 0a: figure out what kind of derived type declaration we have
8023
8024 if Private_Extension then
8025 Type_Def := N;
8026 Set_Ekind (Derived_Type, E_Record_Type_With_Private);
8027 Set_Default_SSO (Derived_Type);
8028
8029 else
8030 Type_Def := Type_Definition (N);
8031
8032 -- Ekind (Parent_Base) is not necessarily E_Record_Type since
8033 -- Parent_Base can be a private type or private extension. However,
8034 -- for tagged types with an extension the newly added fields are
8035 -- visible and hence the Derived_Type is always an E_Record_Type.
8036 -- (except that the parent may have its own private fields).
8037 -- For untagged types we preserve the Ekind of the Parent_Base.
8038
8039 if Present (Record_Extension_Part (Type_Def)) then
8040 Set_Ekind (Derived_Type, E_Record_Type);
8041 Set_Default_SSO (Derived_Type);
8042
8043 -- Create internal access types for components with anonymous
8044 -- access types.
8045
8046 if Ada_Version >= Ada_2005 then
8047 Check_Anonymous_Access_Components
8048 (N, Derived_Type, Derived_Type,
8049 Component_List (Record_Extension_Part (Type_Def)));
8050 end if;
8051
8052 else
8053 Set_Ekind (Derived_Type, Ekind (Parent_Base));
8054 end if;
8055 end if;
8056
8057 -- Indic can either be an N_Identifier if the subtype indication
8058 -- contains no constraint or an N_Subtype_Indication if the subtype
8059 -- indication has a constraint.
8060
8061 Indic := Subtype_Indication (Type_Def);
8062 Constraint_Present := (Nkind (Indic) = N_Subtype_Indication);
8063
8064 -- Check that the type has visible discriminants. The type may be
8065 -- a private type with unknown discriminants whose full view has
8066 -- discriminants which are invisible.
8067
8068 if Constraint_Present then
8069 if not Has_Discriminants (Parent_Base)
8070 or else
8071 (Has_Unknown_Discriminants (Parent_Base)
8072 and then Is_Private_Type (Parent_Base))
8073 then
8074 Error_Msg_N
8075 ("invalid constraint: type has no discriminant",
8076 Constraint (Indic));
8077
8078 Constraint_Present := False;
8079 Rewrite (Indic, New_Copy_Tree (Subtype_Mark (Indic)));
8080
8081 elsif Is_Constrained (Parent_Type) then
8082 Error_Msg_N
8083 ("invalid constraint: parent type is already constrained",
8084 Constraint (Indic));
8085
8086 Constraint_Present := False;
8087 Rewrite (Indic, New_Copy_Tree (Subtype_Mark (Indic)));
8088 end if;
8089 end if;
8090
8091 -- STEP 0b: If needed, apply transformation given in point 5. above
8092
8093 if not Private_Extension
8094 and then Has_Discriminants (Parent_Type)
8095 and then not Discriminant_Specs
8096 and then (Is_Constrained (Parent_Type) or else Constraint_Present)
8097 then
8098 -- First, we must analyze the constraint (see comment in point 5.)
8099 -- The constraint may come from the subtype indication of the full
8100 -- declaration.
8101
8102 if Constraint_Present then
8103 New_Discrs := Build_Discriminant_Constraints (Parent_Type, Indic);
8104
8105 -- If there is no explicit constraint, there might be one that is
8106 -- inherited from a constrained parent type. In that case verify that
8107 -- it conforms to the constraint in the partial view. In perverse
8108 -- cases the parent subtypes of the partial and full view can have
8109 -- different constraints.
8110
8111 elsif Present (Stored_Constraint (Parent_Type)) then
8112 New_Discrs := Stored_Constraint (Parent_Type);
8113
8114 else
8115 New_Discrs := No_Elist;
8116 end if;
8117
8118 if Has_Discriminants (Derived_Type)
8119 and then Has_Private_Declaration (Derived_Type)
8120 and then Present (Discriminant_Constraint (Derived_Type))
8121 and then Present (New_Discrs)
8122 then
8123 -- Verify that constraints of the full view statically match
8124 -- those given in the partial view.
8125
8126 declare
8127 C1, C2 : Elmt_Id;
8128
8129 begin
8130 C1 := First_Elmt (New_Discrs);
8131 C2 := First_Elmt (Discriminant_Constraint (Derived_Type));
8132 while Present (C1) and then Present (C2) loop
8133 if Fully_Conformant_Expressions (Node (C1), Node (C2))
8134 or else
8135 (Is_OK_Static_Expression (Node (C1))
8136 and then Is_OK_Static_Expression (Node (C2))
8137 and then
8138 Expr_Value (Node (C1)) = Expr_Value (Node (C2)))
8139 then
8140 null;
8141
8142 else
8143 if Constraint_Present then
8144 Error_Msg_N
8145 ("constraint not conformant to previous declaration",
8146 Node (C1));
8147 else
8148 Error_Msg_N
8149 ("constraint of full view is incompatible "
8150 & "with partial view", N);
8151 end if;
8152 end if;
8153
8154 Next_Elmt (C1);
8155 Next_Elmt (C2);
8156 end loop;
8157 end;
8158 end if;
8159
8160 -- Insert and analyze the declaration for the unconstrained base type
8161
8162 New_Base := Create_Itype (Ekind (Derived_Type), N, Derived_Type, 'B');
8163
8164 New_Decl :=
8165 Make_Full_Type_Declaration (Loc,
8166 Defining_Identifier => New_Base,
8167 Type_Definition =>
8168 Make_Derived_Type_Definition (Loc,
8169 Abstract_Present => Abstract_Present (Type_Def),
8170 Limited_Present => Limited_Present (Type_Def),
8171 Subtype_Indication =>
8172 New_Occurrence_Of (Parent_Base, Loc),
8173 Record_Extension_Part =>
8174 Relocate_Node (Record_Extension_Part (Type_Def)),
8175 Interface_List => Interface_List (Type_Def)));
8176
8177 Set_Parent (New_Decl, Parent (N));
8178 Mark_Rewrite_Insertion (New_Decl);
8179 Insert_Before (N, New_Decl);
8180
8181 -- In the extension case, make sure ancestor is frozen appropriately
8182 -- (see also non-discriminated case below).
8183
8184 if Present (Record_Extension_Part (Type_Def))
8185 or else Is_Interface (Parent_Base)
8186 then
8187 Freeze_Before (New_Decl, Parent_Type);
8188 end if;
8189
8190 -- Note that this call passes False for the Derive_Subps parameter
8191 -- because subprogram derivation is deferred until after creating
8192 -- the subtype (see below).
8193
8194 Build_Derived_Type
8195 (New_Decl, Parent_Base, New_Base,
8196 Is_Completion => False, Derive_Subps => False);
8197
8198 -- ??? This needs re-examination to determine whether the
8199 -- above call can simply be replaced by a call to Analyze.
8200
8201 Set_Analyzed (New_Decl);
8202
8203 -- Insert and analyze the declaration for the constrained subtype
8204
8205 if Constraint_Present then
8206 New_Indic :=
8207 Make_Subtype_Indication (Loc,
8208 Subtype_Mark => New_Occurrence_Of (New_Base, Loc),
8209 Constraint => Relocate_Node (Constraint (Indic)));
8210
8211 else
8212 declare
8213 Constr_List : constant List_Id := New_List;
8214 C : Elmt_Id;
8215 Expr : Node_Id;
8216
8217 begin
8218 C := First_Elmt (Discriminant_Constraint (Parent_Type));
8219 while Present (C) loop
8220 Expr := Node (C);
8221
8222 -- It is safe here to call New_Copy_Tree since we called
8223 -- Force_Evaluation on each constraint previously
8224 -- in Build_Discriminant_Constraints.
8225
8226 Append (New_Copy_Tree (Expr), To => Constr_List);
8227
8228 Next_Elmt (C);
8229 end loop;
8230
8231 New_Indic :=
8232 Make_Subtype_Indication (Loc,
8233 Subtype_Mark => New_Occurrence_Of (New_Base, Loc),
8234 Constraint =>
8235 Make_Index_Or_Discriminant_Constraint (Loc, Constr_List));
8236 end;
8237 end if;
8238
8239 Rewrite (N,
8240 Make_Subtype_Declaration (Loc,
8241 Defining_Identifier => Derived_Type,
8242 Subtype_Indication => New_Indic));
8243
8244 Analyze (N);
8245
8246 -- Derivation of subprograms must be delayed until the full subtype
8247 -- has been established, to ensure proper overriding of subprograms
8248 -- inherited by full types. If the derivations occurred as part of
8249 -- the call to Build_Derived_Type above, then the check for type
8250 -- conformance would fail because earlier primitive subprograms
8251 -- could still refer to the full type prior the change to the new
8252 -- subtype and hence would not match the new base type created here.
8253 -- Subprograms are not derived, however, when Derive_Subps is False
8254 -- (since otherwise there could be redundant derivations).
8255
8256 if Derive_Subps then
8257 Derive_Subprograms (Parent_Type, Derived_Type);
8258 end if;
8259
8260 -- For tagged types the Discriminant_Constraint of the new base itype
8261 -- is inherited from the first subtype so that no subtype conformance
8262 -- problem arise when the first subtype overrides primitive
8263 -- operations inherited by the implicit base type.
8264
8265 if Is_Tagged then
8266 Set_Discriminant_Constraint
8267 (New_Base, Discriminant_Constraint (Derived_Type));
8268 end if;
8269
8270 return;
8271 end if;
8272
8273 -- If we get here Derived_Type will have no discriminants or it will be
8274 -- a discriminated unconstrained base type.
8275
8276 -- STEP 1a: perform preliminary actions/checks for derived tagged types
8277
8278 if Is_Tagged then
8279
8280 -- The parent type is frozen for non-private extensions (RM 13.14(7))
8281 -- The declaration of a specific descendant of an interface type
8282 -- freezes the interface type (RM 13.14).
8283
8284 if not Private_Extension or else Is_Interface (Parent_Base) then
8285 Freeze_Before (N, Parent_Type);
8286 end if;
8287
8288 -- In Ada 2005 (AI-344), the restriction that a derived tagged type
8289 -- cannot be declared at a deeper level than its parent type is
8290 -- removed. The check on derivation within a generic body is also
8291 -- relaxed, but there's a restriction that a derived tagged type
8292 -- cannot be declared in a generic body if it's derived directly
8293 -- or indirectly from a formal type of that generic.
8294
8295 if Ada_Version >= Ada_2005 then
8296 if Present (Enclosing_Generic_Body (Derived_Type)) then
8297 declare
8298 Ancestor_Type : Entity_Id;
8299
8300 begin
8301 -- Check to see if any ancestor of the derived type is a
8302 -- formal type.
8303
8304 Ancestor_Type := Parent_Type;
8305 while not Is_Generic_Type (Ancestor_Type)
8306 and then Etype (Ancestor_Type) /= Ancestor_Type
8307 loop
8308 Ancestor_Type := Etype (Ancestor_Type);
8309 end loop;
8310
8311 -- If the derived type does have a formal type as an
8312 -- ancestor, then it's an error if the derived type is
8313 -- declared within the body of the generic unit that
8314 -- declares the formal type in its generic formal part. It's
8315 -- sufficient to check whether the ancestor type is declared
8316 -- inside the same generic body as the derived type (such as
8317 -- within a nested generic spec), in which case the
8318 -- derivation is legal. If the formal type is declared
8319 -- outside of that generic body, then it's guaranteed that
8320 -- the derived type is declared within the generic body of
8321 -- the generic unit declaring the formal type.
8322
8323 if Is_Generic_Type (Ancestor_Type)
8324 and then Enclosing_Generic_Body (Ancestor_Type) /=
8325 Enclosing_Generic_Body (Derived_Type)
8326 then
8327 Error_Msg_NE
8328 ("parent type of& must not be descendant of formal type"
8329 & " of an enclosing generic body",
8330 Indic, Derived_Type);
8331 end if;
8332 end;
8333 end if;
8334
8335 elsif Type_Access_Level (Derived_Type) /=
8336 Type_Access_Level (Parent_Type)
8337 and then not Is_Generic_Type (Derived_Type)
8338 then
8339 if Is_Controlled (Parent_Type) then
8340 Error_Msg_N
8341 ("controlled type must be declared at the library level",
8342 Indic);
8343 else
8344 Error_Msg_N
8345 ("type extension at deeper accessibility level than parent",
8346 Indic);
8347 end if;
8348
8349 else
8350 declare
8351 GB : constant Node_Id := Enclosing_Generic_Body (Derived_Type);
8352 begin
8353 if Present (GB)
8354 and then GB /= Enclosing_Generic_Body (Parent_Base)
8355 then
8356 Error_Msg_NE
8357 ("parent type of& must not be outside generic body"
8358 & " (RM 3.9.1(4))",
8359 Indic, Derived_Type);
8360 end if;
8361 end;
8362 end if;
8363 end if;
8364
8365 -- Ada 2005 (AI-251)
8366
8367 if Ada_Version >= Ada_2005 and then Is_Tagged then
8368
8369 -- "The declaration of a specific descendant of an interface type
8370 -- freezes the interface type" (RM 13.14).
8371
8372 declare
8373 Iface : Node_Id;
8374 begin
8375 if Is_Non_Empty_List (Interface_List (Type_Def)) then
8376 Iface := First (Interface_List (Type_Def));
8377 while Present (Iface) loop
8378 Freeze_Before (N, Etype (Iface));
8379 Next (Iface);
8380 end loop;
8381 end if;
8382 end;
8383 end if;
8384
8385 -- STEP 1b : preliminary cleanup of the full view of private types
8386
8387 -- If the type is already marked as having discriminants, then it's the
8388 -- completion of a private type or private extension and we need to
8389 -- retain the discriminants from the partial view if the current
8390 -- declaration has Discriminant_Specifications so that we can verify
8391 -- conformance. However, we must remove any existing components that
8392 -- were inherited from the parent (and attached in Copy_And_Swap)
8393 -- because the full type inherits all appropriate components anyway, and
8394 -- we do not want the partial view's components interfering.
8395
8396 if Has_Discriminants (Derived_Type) and then Discriminant_Specs then
8397 Discrim := First_Discriminant (Derived_Type);
8398 loop
8399 Last_Discrim := Discrim;
8400 Next_Discriminant (Discrim);
8401 exit when No (Discrim);
8402 end loop;
8403
8404 Set_Last_Entity (Derived_Type, Last_Discrim);
8405
8406 -- In all other cases wipe out the list of inherited components (even
8407 -- inherited discriminants), it will be properly rebuilt here.
8408
8409 else
8410 Set_First_Entity (Derived_Type, Empty);
8411 Set_Last_Entity (Derived_Type, Empty);
8412 end if;
8413
8414 -- STEP 1c: Initialize some flags for the Derived_Type
8415
8416 -- The following flags must be initialized here so that
8417 -- Process_Discriminants can check that discriminants of tagged types do
8418 -- not have a default initial value and that access discriminants are
8419 -- only specified for limited records. For completeness, these flags are
8420 -- also initialized along with all the other flags below.
8421
8422 -- AI-419: Limitedness is not inherited from an interface parent, so to
8423 -- be limited in that case the type must be explicitly declared as
8424 -- limited. However, task and protected interfaces are always limited.
8425
8426 if Limited_Present (Type_Def) then
8427 Set_Is_Limited_Record (Derived_Type);
8428
8429 elsif Is_Limited_Record (Parent_Type)
8430 or else (Present (Full_View (Parent_Type))
8431 and then Is_Limited_Record (Full_View (Parent_Type)))
8432 then
8433 if not Is_Interface (Parent_Type)
8434 or else Is_Synchronized_Interface (Parent_Type)
8435 or else Is_Protected_Interface (Parent_Type)
8436 or else Is_Task_Interface (Parent_Type)
8437 then
8438 Set_Is_Limited_Record (Derived_Type);
8439 end if;
8440 end if;
8441
8442 -- STEP 2a: process discriminants of derived type if any
8443
8444 Push_Scope (Derived_Type);
8445
8446 if Discriminant_Specs then
8447 Set_Has_Unknown_Discriminants (Derived_Type, False);
8448
8449 -- The following call initializes fields Has_Discriminants and
8450 -- Discriminant_Constraint, unless we are processing the completion
8451 -- of a private type declaration.
8452
8453 Check_Or_Process_Discriminants (N, Derived_Type);
8454
8455 -- For untagged types, the constraint on the Parent_Type must be
8456 -- present and is used to rename the discriminants.
8457
8458 if not Is_Tagged and then not Has_Discriminants (Parent_Type) then
8459 Error_Msg_N ("untagged parent must have discriminants", Indic);
8460
8461 elsif not Is_Tagged and then not Constraint_Present then
8462 Error_Msg_N
8463 ("discriminant constraint needed for derived untagged records",
8464 Indic);
8465
8466 -- Otherwise the parent subtype must be constrained unless we have a
8467 -- private extension.
8468
8469 elsif not Constraint_Present
8470 and then not Private_Extension
8471 and then not Is_Constrained (Parent_Type)
8472 then
8473 Error_Msg_N
8474 ("unconstrained type not allowed in this context", Indic);
8475
8476 elsif Constraint_Present then
8477 -- The following call sets the field Corresponding_Discriminant
8478 -- for the discriminants in the Derived_Type.
8479
8480 Discs := Build_Discriminant_Constraints (Parent_Type, Indic, True);
8481
8482 -- For untagged types all new discriminants must rename
8483 -- discriminants in the parent. For private extensions new
8484 -- discriminants cannot rename old ones (implied by [7.3(13)]).
8485
8486 Discrim := First_Discriminant (Derived_Type);
8487 while Present (Discrim) loop
8488 if not Is_Tagged
8489 and then No (Corresponding_Discriminant (Discrim))
8490 then
8491 Error_Msg_N
8492 ("new discriminants must constrain old ones", Discrim);
8493
8494 elsif Private_Extension
8495 and then Present (Corresponding_Discriminant (Discrim))
8496 then
8497 Error_Msg_N
8498 ("only static constraints allowed for parent"
8499 & " discriminants in the partial view", Indic);
8500 exit;
8501 end if;
8502
8503 -- If a new discriminant is used in the constraint, then its
8504 -- subtype must be statically compatible with the parent
8505 -- discriminant's subtype (3.7(15)).
8506
8507 -- However, if the record contains an array constrained by
8508 -- the discriminant but with some different bound, the compiler
8509 -- attemps to create a smaller range for the discriminant type.
8510 -- (See exp_ch3.Adjust_Discriminants). In this case, where
8511 -- the discriminant type is a scalar type, the check must use
8512 -- the original discriminant type in the parent declaration.
8513
8514 declare
8515 Corr_Disc : constant Entity_Id :=
8516 Corresponding_Discriminant (Discrim);
8517 Disc_Type : constant Entity_Id := Etype (Discrim);
8518 Corr_Type : Entity_Id;
8519
8520 begin
8521 if Present (Corr_Disc) then
8522 if Is_Scalar_Type (Disc_Type) then
8523 Corr_Type :=
8524 Entity (Discriminant_Type (Parent (Corr_Disc)));
8525 else
8526 Corr_Type := Etype (Corr_Disc);
8527 end if;
8528
8529 if not
8530 Subtypes_Statically_Compatible (Disc_Type, Corr_Type)
8531 then
8532 Error_Msg_N
8533 ("subtype must be compatible "
8534 & "with parent discriminant",
8535 Discrim);
8536 end if;
8537 end if;
8538 end;
8539
8540 Next_Discriminant (Discrim);
8541 end loop;
8542
8543 -- Check whether the constraints of the full view statically
8544 -- match those imposed by the parent subtype [7.3(13)].
8545
8546 if Present (Stored_Constraint (Derived_Type)) then
8547 declare
8548 C1, C2 : Elmt_Id;
8549
8550 begin
8551 C1 := First_Elmt (Discs);
8552 C2 := First_Elmt (Stored_Constraint (Derived_Type));
8553 while Present (C1) and then Present (C2) loop
8554 if not
8555 Fully_Conformant_Expressions (Node (C1), Node (C2))
8556 then
8557 Error_Msg_N
8558 ("not conformant with previous declaration",
8559 Node (C1));
8560 end if;
8561
8562 Next_Elmt (C1);
8563 Next_Elmt (C2);
8564 end loop;
8565 end;
8566 end if;
8567 end if;
8568
8569 -- STEP 2b: No new discriminants, inherit discriminants if any
8570
8571 else
8572 if Private_Extension then
8573 Set_Has_Unknown_Discriminants
8574 (Derived_Type,
8575 Has_Unknown_Discriminants (Parent_Type)
8576 or else Unknown_Discriminants_Present (N));
8577
8578 -- The partial view of the parent may have unknown discriminants,
8579 -- but if the full view has discriminants and the parent type is
8580 -- in scope they must be inherited.
8581
8582 elsif Has_Unknown_Discriminants (Parent_Type)
8583 and then
8584 (not Has_Discriminants (Parent_Type)
8585 or else not In_Open_Scopes (Scope (Parent_Type)))
8586 then
8587 Set_Has_Unknown_Discriminants (Derived_Type);
8588 end if;
8589
8590 if not Has_Unknown_Discriminants (Derived_Type)
8591 and then not Has_Unknown_Discriminants (Parent_Base)
8592 and then Has_Discriminants (Parent_Type)
8593 then
8594 Inherit_Discrims := True;
8595 Set_Has_Discriminants
8596 (Derived_Type, True);
8597 Set_Discriminant_Constraint
8598 (Derived_Type, Discriminant_Constraint (Parent_Base));
8599 end if;
8600
8601 -- The following test is true for private types (remember
8602 -- transformation 5. is not applied to those) and in an error
8603 -- situation.
8604
8605 if Constraint_Present then
8606 Discs := Build_Discriminant_Constraints (Parent_Type, Indic);
8607 end if;
8608
8609 -- For now mark a new derived type as constrained only if it has no
8610 -- discriminants. At the end of Build_Derived_Record_Type we properly
8611 -- set this flag in the case of private extensions. See comments in
8612 -- point 9. just before body of Build_Derived_Record_Type.
8613
8614 Set_Is_Constrained
8615 (Derived_Type,
8616 not (Inherit_Discrims
8617 or else Has_Unknown_Discriminants (Derived_Type)));
8618 end if;
8619
8620 -- STEP 3: initialize fields of derived type
8621
8622 Set_Is_Tagged_Type (Derived_Type, Is_Tagged);
8623 Set_Stored_Constraint (Derived_Type, No_Elist);
8624
8625 -- Ada 2005 (AI-251): Private type-declarations can implement interfaces
8626 -- but cannot be interfaces
8627
8628 if not Private_Extension
8629 and then Ekind (Derived_Type) /= E_Private_Type
8630 and then Ekind (Derived_Type) /= E_Limited_Private_Type
8631 then
8632 if Interface_Present (Type_Def) then
8633 Analyze_Interface_Declaration (Derived_Type, Type_Def);
8634 end if;
8635
8636 Set_Interfaces (Derived_Type, No_Elist);
8637 end if;
8638
8639 -- Fields inherited from the Parent_Type
8640
8641 Set_Has_Specified_Layout
8642 (Derived_Type, Has_Specified_Layout (Parent_Type));
8643 Set_Is_Limited_Composite
8644 (Derived_Type, Is_Limited_Composite (Parent_Type));
8645 Set_Is_Private_Composite
8646 (Derived_Type, Is_Private_Composite (Parent_Type));
8647
8648 if Is_Tagged_Type (Parent_Type) then
8649 Set_No_Tagged_Streams_Pragma
8650 (Derived_Type, No_Tagged_Streams_Pragma (Parent_Type));
8651 end if;
8652
8653 -- Fields inherited from the Parent_Base
8654
8655 Set_Has_Controlled_Component
8656 (Derived_Type, Has_Controlled_Component (Parent_Base));
8657 Set_Has_Non_Standard_Rep
8658 (Derived_Type, Has_Non_Standard_Rep (Parent_Base));
8659 Set_Has_Primitive_Operations
8660 (Derived_Type, Has_Primitive_Operations (Parent_Base));
8661
8662 -- Fields inherited from the Parent_Base in the non-private case
8663
8664 if Ekind (Derived_Type) = E_Record_Type then
8665 Set_Has_Complex_Representation
8666 (Derived_Type, Has_Complex_Representation (Parent_Base));
8667 end if;
8668
8669 -- Fields inherited from the Parent_Base for record types
8670
8671 if Is_Record_Type (Derived_Type) then
8672 declare
8673 Parent_Full : Entity_Id;
8674
8675 begin
8676 -- Ekind (Parent_Base) is not necessarily E_Record_Type since
8677 -- Parent_Base can be a private type or private extension. Go
8678 -- to the full view here to get the E_Record_Type specific flags.
8679
8680 if Present (Full_View (Parent_Base)) then
8681 Parent_Full := Full_View (Parent_Base);
8682 else
8683 Parent_Full := Parent_Base;
8684 end if;
8685
8686 Set_OK_To_Reorder_Components
8687 (Derived_Type, OK_To_Reorder_Components (Parent_Full));
8688 end;
8689 end if;
8690
8691 -- Set fields for private derived types
8692
8693 if Is_Private_Type (Derived_Type) then
8694 Set_Depends_On_Private (Derived_Type, True);
8695 Set_Private_Dependents (Derived_Type, New_Elmt_List);
8696
8697 -- Inherit fields from non private record types. If this is the
8698 -- completion of a derivation from a private type, the parent itself
8699 -- is private, and the attributes come from its full view, which must
8700 -- be present.
8701
8702 else
8703 if Is_Private_Type (Parent_Base)
8704 and then not Is_Record_Type (Parent_Base)
8705 then
8706 Set_Component_Alignment
8707 (Derived_Type, Component_Alignment (Full_View (Parent_Base)));
8708 Set_C_Pass_By_Copy
8709 (Derived_Type, C_Pass_By_Copy (Full_View (Parent_Base)));
8710 else
8711 Set_Component_Alignment
8712 (Derived_Type, Component_Alignment (Parent_Base));
8713 Set_C_Pass_By_Copy
8714 (Derived_Type, C_Pass_By_Copy (Parent_Base));
8715 end if;
8716 end if;
8717
8718 -- Set fields for tagged types
8719
8720 if Is_Tagged then
8721 Set_Direct_Primitive_Operations (Derived_Type, New_Elmt_List);
8722
8723 -- All tagged types defined in Ada.Finalization are controlled
8724
8725 if Chars (Scope (Derived_Type)) = Name_Finalization
8726 and then Chars (Scope (Scope (Derived_Type))) = Name_Ada
8727 and then Scope (Scope (Scope (Derived_Type))) = Standard_Standard
8728 then
8729 Set_Is_Controlled (Derived_Type);
8730 else
8731 Set_Is_Controlled (Derived_Type, Is_Controlled (Parent_Base));
8732 end if;
8733
8734 -- Minor optimization: there is no need to generate the class-wide
8735 -- entity associated with an underlying record view.
8736
8737 if not Is_Underlying_Record_View (Derived_Type) then
8738 Make_Class_Wide_Type (Derived_Type);
8739 end if;
8740
8741 Set_Is_Abstract_Type (Derived_Type, Abstract_Present (Type_Def));
8742
8743 if Has_Discriminants (Derived_Type)
8744 and then Constraint_Present
8745 then
8746 Set_Stored_Constraint
8747 (Derived_Type, Expand_To_Stored_Constraint (Parent_Base, Discs));
8748 end if;
8749
8750 if Ada_Version >= Ada_2005 then
8751 declare
8752 Ifaces_List : Elist_Id;
8753
8754 begin
8755 -- Checks rules 3.9.4 (13/2 and 14/2)
8756
8757 if Comes_From_Source (Derived_Type)
8758 and then not Is_Private_Type (Derived_Type)
8759 and then Is_Interface (Parent_Type)
8760 and then not Is_Interface (Derived_Type)
8761 then
8762 if Is_Task_Interface (Parent_Type) then
8763 Error_Msg_N
8764 ("(Ada 2005) task type required (RM 3.9.4 (13.2))",
8765 Derived_Type);
8766
8767 elsif Is_Protected_Interface (Parent_Type) then
8768 Error_Msg_N
8769 ("(Ada 2005) protected type required (RM 3.9.4 (14.2))",
8770 Derived_Type);
8771 end if;
8772 end if;
8773
8774 -- Check ARM rules 3.9.4 (15/2), 9.1 (9.d/2) and 9.4 (11.d/2)
8775
8776 Check_Interfaces (N, Type_Def);
8777
8778 -- Ada 2005 (AI-251): Collect the list of progenitors that are
8779 -- not already in the parents.
8780
8781 Collect_Interfaces
8782 (T => Derived_Type,
8783 Ifaces_List => Ifaces_List,
8784 Exclude_Parents => True);
8785
8786 Set_Interfaces (Derived_Type, Ifaces_List);
8787
8788 -- If the derived type is the anonymous type created for
8789 -- a declaration whose parent has a constraint, propagate
8790 -- the interface list to the source type. This must be done
8791 -- prior to the completion of the analysis of the source type
8792 -- because the components in the extension may contain current
8793 -- instances whose legality depends on some ancestor.
8794
8795 if Is_Itype (Derived_Type) then
8796 declare
8797 Def : constant Node_Id :=
8798 Associated_Node_For_Itype (Derived_Type);
8799 begin
8800 if Present (Def)
8801 and then Nkind (Def) = N_Full_Type_Declaration
8802 then
8803 Set_Interfaces
8804 (Defining_Identifier (Def), Ifaces_List);
8805 end if;
8806 end;
8807 end if;
8808
8809 -- A derived type inherits any class-wide invariants coming
8810 -- from a parent type or an interface. Note that the invariant
8811 -- procedure of the parent type should not be inherited because
8812 -- the derived type may define invariants of its own.
8813
8814 if Ada_Version >= Ada_2012
8815 and then not Is_Interface (Derived_Type)
8816 then
8817 if Has_Inherited_Invariants (Parent_Type)
8818 or else Has_Inheritable_Invariants (Parent_Type)
8819 then
8820 Set_Has_Inherited_Invariants (Derived_Type);
8821
8822 elsif not Is_Empty_Elmt_List (Ifaces_List) then
8823 declare
8824 Iface : Entity_Id;
8825 Iface_Elmt : Elmt_Id;
8826
8827 begin
8828 Iface_Elmt := First_Elmt (Ifaces_List);
8829 while Present (Iface_Elmt) loop
8830 Iface := Node (Iface_Elmt);
8831
8832 if Has_Inheritable_Invariants (Iface) then
8833 Set_Has_Inherited_Invariants (Derived_Type);
8834 exit;
8835 end if;
8836
8837 Next_Elmt (Iface_Elmt);
8838 end loop;
8839 end;
8840 end if;
8841 end if;
8842
8843 -- A type extension is automatically Ghost when one of its
8844 -- progenitors is Ghost (SPARK RM 6.9(9)). This property is
8845 -- also inherited when the parent type is Ghost, but this is
8846 -- done in Build_Derived_Type as the mechanism also handles
8847 -- untagged derivations.
8848
8849 if Implements_Ghost_Interface (Derived_Type) then
8850 Set_Is_Ghost_Entity (Derived_Type);
8851 end if;
8852 end;
8853 end if;
8854
8855 else
8856 Set_Is_Packed (Derived_Type, Is_Packed (Parent_Base));
8857 Set_Has_Non_Standard_Rep
8858 (Derived_Type, Has_Non_Standard_Rep (Parent_Base));
8859 end if;
8860
8861 -- STEP 4: Inherit components from the parent base and constrain them.
8862 -- Apply the second transformation described in point 6. above.
8863
8864 if (not Is_Empty_Elmt_List (Discs) or else Inherit_Discrims)
8865 or else not Has_Discriminants (Parent_Type)
8866 or else not Is_Constrained (Parent_Type)
8867 then
8868 Constrs := Discs;
8869 else
8870 Constrs := Discriminant_Constraint (Parent_Type);
8871 end if;
8872
8873 Assoc_List :=
8874 Inherit_Components
8875 (N, Parent_Base, Derived_Type, Is_Tagged, Inherit_Discrims, Constrs);
8876
8877 -- STEP 5a: Copy the parent record declaration for untagged types
8878
8879 if not Is_Tagged then
8880
8881 -- Discriminant_Constraint (Derived_Type) has been properly
8882 -- constructed. Save it and temporarily set it to Empty because we
8883 -- do not want the call to New_Copy_Tree below to mess this list.
8884
8885 if Has_Discriminants (Derived_Type) then
8886 Save_Discr_Constr := Discriminant_Constraint (Derived_Type);
8887 Set_Discriminant_Constraint (Derived_Type, No_Elist);
8888 else
8889 Save_Discr_Constr := No_Elist;
8890 end if;
8891
8892 -- Save the Etype field of Derived_Type. It is correctly set now,
8893 -- but the call to New_Copy tree may remap it to point to itself,
8894 -- which is not what we want. Ditto for the Next_Entity field.
8895
8896 Save_Etype := Etype (Derived_Type);
8897 Save_Next_Entity := Next_Entity (Derived_Type);
8898
8899 -- Assoc_List maps all stored discriminants in the Parent_Base to
8900 -- stored discriminants in the Derived_Type. It is fundamental that
8901 -- no types or itypes with discriminants other than the stored
8902 -- discriminants appear in the entities declared inside
8903 -- Derived_Type, since the back end cannot deal with it.
8904
8905 New_Decl :=
8906 New_Copy_Tree
8907 (Parent (Parent_Base), Map => Assoc_List, New_Sloc => Loc);
8908
8909 -- Restore the fields saved prior to the New_Copy_Tree call
8910 -- and compute the stored constraint.
8911
8912 Set_Etype (Derived_Type, Save_Etype);
8913 Set_Next_Entity (Derived_Type, Save_Next_Entity);
8914
8915 if Has_Discriminants (Derived_Type) then
8916 Set_Discriminant_Constraint
8917 (Derived_Type, Save_Discr_Constr);
8918 Set_Stored_Constraint
8919 (Derived_Type, Expand_To_Stored_Constraint (Parent_Type, Discs));
8920 Replace_Components (Derived_Type, New_Decl);
8921 Set_Has_Implicit_Dereference
8922 (Derived_Type, Has_Implicit_Dereference (Parent_Type));
8923 end if;
8924
8925 -- Insert the new derived type declaration
8926
8927 Rewrite (N, New_Decl);
8928
8929 -- STEP 5b: Complete the processing for record extensions in generics
8930
8931 -- There is no completion for record extensions declared in the
8932 -- parameter part of a generic, so we need to complete processing for
8933 -- these generic record extensions here. The Record_Type_Definition call
8934 -- will change the Ekind of the components from E_Void to E_Component.
8935
8936 elsif Private_Extension and then Is_Generic_Type (Derived_Type) then
8937 Record_Type_Definition (Empty, Derived_Type);
8938
8939 -- STEP 5c: Process the record extension for non private tagged types
8940
8941 elsif not Private_Extension then
8942 Expand_Record_Extension (Derived_Type, Type_Def);
8943
8944 -- Note : previously in ASIS mode we set the Parent_Subtype of the
8945 -- derived type to propagate some semantic information. This led
8946 -- to other ASIS failures and has been removed.
8947
8948 -- Ada 2005 (AI-251): Addition of the Tag corresponding to all the
8949 -- implemented interfaces if we are in expansion mode
8950
8951 if Expander_Active
8952 and then Has_Interfaces (Derived_Type)
8953 then
8954 Add_Interface_Tag_Components (N, Derived_Type);
8955 end if;
8956
8957 -- Analyze the record extension
8958
8959 Record_Type_Definition
8960 (Record_Extension_Part (Type_Def), Derived_Type);
8961 end if;
8962
8963 End_Scope;
8964
8965 -- Nothing else to do if there is an error in the derivation.
8966 -- An unusual case: the full view may be derived from a type in an
8967 -- instance, when the partial view was used illegally as an actual
8968 -- in that instance, leading to a circular definition.
8969
8970 if Etype (Derived_Type) = Any_Type
8971 or else Etype (Parent_Type) = Derived_Type
8972 then
8973 return;
8974 end if;
8975
8976 -- Set delayed freeze and then derive subprograms, we need to do
8977 -- this in this order so that derived subprograms inherit the
8978 -- derived freeze if necessary.
8979
8980 Set_Has_Delayed_Freeze (Derived_Type);
8981
8982 if Derive_Subps then
8983 Derive_Subprograms (Parent_Type, Derived_Type);
8984 end if;
8985
8986 -- If we have a private extension which defines a constrained derived
8987 -- type mark as constrained here after we have derived subprograms. See
8988 -- comment on point 9. just above the body of Build_Derived_Record_Type.
8989
8990 if Private_Extension and then Inherit_Discrims then
8991 if Constraint_Present and then not Is_Empty_Elmt_List (Discs) then
8992 Set_Is_Constrained (Derived_Type, True);
8993 Set_Discriminant_Constraint (Derived_Type, Discs);
8994
8995 elsif Is_Constrained (Parent_Type) then
8996 Set_Is_Constrained
8997 (Derived_Type, True);
8998 Set_Discriminant_Constraint
8999 (Derived_Type, Discriminant_Constraint (Parent_Type));
9000 end if;
9001 end if;
9002
9003 -- Update the class-wide type, which shares the now-completed entity
9004 -- list with its specific type. In case of underlying record views,
9005 -- we do not generate the corresponding class wide entity.
9006
9007 if Is_Tagged
9008 and then not Is_Underlying_Record_View (Derived_Type)
9009 then
9010 Set_First_Entity
9011 (Class_Wide_Type (Derived_Type), First_Entity (Derived_Type));
9012 Set_Last_Entity
9013 (Class_Wide_Type (Derived_Type), Last_Entity (Derived_Type));
9014 end if;
9015
9016 Check_Function_Writable_Actuals (N);
9017 end Build_Derived_Record_Type;
9018
9019 ------------------------
9020 -- Build_Derived_Type --
9021 ------------------------
9022
9023 procedure Build_Derived_Type
9024 (N : Node_Id;
9025 Parent_Type : Entity_Id;
9026 Derived_Type : Entity_Id;
9027 Is_Completion : Boolean;
9028 Derive_Subps : Boolean := True)
9029 is
9030 Parent_Base : constant Entity_Id := Base_Type (Parent_Type);
9031
9032 begin
9033 -- Set common attributes
9034
9035 Set_Scope (Derived_Type, Current_Scope);
9036
9037 Set_Etype (Derived_Type, Parent_Base);
9038 Set_Ekind (Derived_Type, Ekind (Parent_Base));
9039 Propagate_Concurrent_Flags (Derived_Type, Parent_Base);
9040
9041 Set_Size_Info (Derived_Type, Parent_Type);
9042 Set_RM_Size (Derived_Type, RM_Size (Parent_Type));
9043 Set_Is_Controlled (Derived_Type, Is_Controlled (Parent_Type));
9044 Set_Disable_Controlled (Derived_Type, Disable_Controlled (Parent_Type));
9045
9046 Set_Is_Tagged_Type (Derived_Type, Is_Tagged_Type (Parent_Type));
9047 Set_Is_Volatile (Derived_Type, Is_Volatile (Parent_Type));
9048
9049 if Is_Tagged_Type (Derived_Type) then
9050 Set_No_Tagged_Streams_Pragma
9051 (Derived_Type, No_Tagged_Streams_Pragma (Parent_Type));
9052 end if;
9053
9054 -- If the parent has primitive routines, set the derived type link
9055
9056 if Has_Primitive_Operations (Parent_Type) then
9057 Set_Derived_Type_Link (Parent_Base, Derived_Type);
9058 end if;
9059
9060 -- If the parent type is a private subtype, the convention on the base
9061 -- type may be set in the private part, and not propagated to the
9062 -- subtype until later, so we obtain the convention from the base type.
9063
9064 Set_Convention (Derived_Type, Convention (Parent_Base));
9065
9066 -- Set SSO default for record or array type
9067
9068 if (Is_Array_Type (Derived_Type) or else Is_Record_Type (Derived_Type))
9069 and then Is_Base_Type (Derived_Type)
9070 then
9071 Set_Default_SSO (Derived_Type);
9072 end if;
9073
9074 -- Propagate invariant information. The new type has invariants if
9075 -- they are inherited from the parent type, and these invariants can
9076 -- be further inherited, so both flags are set.
9077
9078 -- We similarly inherit predicates
9079
9080 if Has_Predicates (Parent_Type) then
9081 Set_Has_Predicates (Derived_Type);
9082 end if;
9083
9084 -- The derived type inherits the representation clauses of the parent
9085
9086 Inherit_Rep_Item_Chain (Derived_Type, Parent_Type);
9087
9088 -- Propagate the attributes related to pragma Default_Initial_Condition
9089 -- from the parent type to the private extension. A derived type always
9090 -- inherits the default initial condition flag from the parent type. If
9091 -- the derived type carries its own Default_Initial_Condition pragma,
9092 -- the flag is later reset in Analyze_Pragma. Note that both flags are
9093 -- mutually exclusive.
9094
9095 Propagate_Default_Init_Cond_Attributes
9096 (From_Typ => Parent_Type,
9097 To_Typ => Derived_Type,
9098 Parent_To_Derivation => True);
9099
9100 -- If the parent type has delayed rep aspects, then mark the derived
9101 -- type as possibly inheriting a delayed rep aspect.
9102
9103 if Has_Delayed_Rep_Aspects (Parent_Type) then
9104 Set_May_Inherit_Delayed_Rep_Aspects (Derived_Type);
9105 end if;
9106
9107 -- Propagate the attributes related to pragma Ghost from the parent type
9108 -- to the derived type or type extension (SPARK RM 6.9(9)).
9109
9110 if Is_Ghost_Entity (Parent_Type) then
9111 Set_Is_Ghost_Entity (Derived_Type);
9112 end if;
9113
9114 -- Type dependent processing
9115
9116 case Ekind (Parent_Type) is
9117 when Numeric_Kind =>
9118 Build_Derived_Numeric_Type (N, Parent_Type, Derived_Type);
9119
9120 when Array_Kind =>
9121 Build_Derived_Array_Type (N, Parent_Type, Derived_Type);
9122
9123 when E_Record_Type
9124 | E_Record_Subtype
9125 | Class_Wide_Kind =>
9126 Build_Derived_Record_Type
9127 (N, Parent_Type, Derived_Type, Derive_Subps);
9128 return;
9129
9130 when Enumeration_Kind =>
9131 Build_Derived_Enumeration_Type (N, Parent_Type, Derived_Type);
9132
9133 when Access_Kind =>
9134 Build_Derived_Access_Type (N, Parent_Type, Derived_Type);
9135
9136 when Incomplete_Or_Private_Kind =>
9137 Build_Derived_Private_Type
9138 (N, Parent_Type, Derived_Type, Is_Completion, Derive_Subps);
9139
9140 -- For discriminated types, the derivation includes deriving
9141 -- primitive operations. For others it is done below.
9142
9143 if Is_Tagged_Type (Parent_Type)
9144 or else Has_Discriminants (Parent_Type)
9145 or else (Present (Full_View (Parent_Type))
9146 and then Has_Discriminants (Full_View (Parent_Type)))
9147 then
9148 return;
9149 end if;
9150
9151 when Concurrent_Kind =>
9152 Build_Derived_Concurrent_Type (N, Parent_Type, Derived_Type);
9153
9154 when others =>
9155 raise Program_Error;
9156 end case;
9157
9158 -- Nothing more to do if some error occurred
9159
9160 if Etype (Derived_Type) = Any_Type then
9161 return;
9162 end if;
9163
9164 -- Set delayed freeze and then derive subprograms, we need to do this
9165 -- in this order so that derived subprograms inherit the derived freeze
9166 -- if necessary.
9167
9168 Set_Has_Delayed_Freeze (Derived_Type);
9169
9170 if Derive_Subps then
9171 Derive_Subprograms (Parent_Type, Derived_Type);
9172 end if;
9173
9174 Set_Has_Primitive_Operations
9175 (Base_Type (Derived_Type), Has_Primitive_Operations (Parent_Type));
9176 end Build_Derived_Type;
9177
9178 -----------------------
9179 -- Build_Discriminal --
9180 -----------------------
9181
9182 procedure Build_Discriminal (Discrim : Entity_Id) is
9183 D_Minal : Entity_Id;
9184 CR_Disc : Entity_Id;
9185
9186 begin
9187 -- A discriminal has the same name as the discriminant
9188
9189 D_Minal := Make_Defining_Identifier (Sloc (Discrim), Chars (Discrim));
9190
9191 Set_Ekind (D_Minal, E_In_Parameter);
9192 Set_Mechanism (D_Minal, Default_Mechanism);
9193 Set_Etype (D_Minal, Etype (Discrim));
9194 Set_Scope (D_Minal, Current_Scope);
9195 Set_Parent (D_Minal, Parent (Discrim));
9196
9197 Set_Discriminal (Discrim, D_Minal);
9198 Set_Discriminal_Link (D_Minal, Discrim);
9199
9200 -- For task types, build at once the discriminants of the corresponding
9201 -- record, which are needed if discriminants are used in entry defaults
9202 -- and in family bounds.
9203
9204 if Is_Concurrent_Type (Current_Scope)
9205 or else
9206 Is_Limited_Type (Current_Scope)
9207 then
9208 CR_Disc := Make_Defining_Identifier (Sloc (Discrim), Chars (Discrim));
9209
9210 Set_Ekind (CR_Disc, E_In_Parameter);
9211 Set_Mechanism (CR_Disc, Default_Mechanism);
9212 Set_Etype (CR_Disc, Etype (Discrim));
9213 Set_Scope (CR_Disc, Current_Scope);
9214 Set_Discriminal_Link (CR_Disc, Discrim);
9215 Set_CR_Discriminant (Discrim, CR_Disc);
9216 end if;
9217 end Build_Discriminal;
9218
9219 ------------------------------------
9220 -- Build_Discriminant_Constraints --
9221 ------------------------------------
9222
9223 function Build_Discriminant_Constraints
9224 (T : Entity_Id;
9225 Def : Node_Id;
9226 Derived_Def : Boolean := False) return Elist_Id
9227 is
9228 C : constant Node_Id := Constraint (Def);
9229 Nb_Discr : constant Nat := Number_Discriminants (T);
9230
9231 Discr_Expr : array (1 .. Nb_Discr) of Node_Id := (others => Empty);
9232 -- Saves the expression corresponding to a given discriminant in T
9233
9234 function Pos_Of_Discr (T : Entity_Id; D : Entity_Id) return Nat;
9235 -- Return the Position number within array Discr_Expr of a discriminant
9236 -- D within the discriminant list of the discriminated type T.
9237
9238 procedure Process_Discriminant_Expression
9239 (Expr : Node_Id;
9240 D : Entity_Id);
9241 -- If this is a discriminant constraint on a partial view, do not
9242 -- generate an overflow check on the discriminant expression. The check
9243 -- will be generated when constraining the full view. Otherwise the
9244 -- backend creates duplicate symbols for the temporaries corresponding
9245 -- to the expressions to be checked, causing spurious assembler errors.
9246
9247 ------------------
9248 -- Pos_Of_Discr --
9249 ------------------
9250
9251 function Pos_Of_Discr (T : Entity_Id; D : Entity_Id) return Nat is
9252 Disc : Entity_Id;
9253
9254 begin
9255 Disc := First_Discriminant (T);
9256 for J in Discr_Expr'Range loop
9257 if Disc = D then
9258 return J;
9259 end if;
9260
9261 Next_Discriminant (Disc);
9262 end loop;
9263
9264 -- Note: Since this function is called on discriminants that are
9265 -- known to belong to the discriminated type, falling through the
9266 -- loop with no match signals an internal compiler error.
9267
9268 raise Program_Error;
9269 end Pos_Of_Discr;
9270
9271 -------------------------------------
9272 -- Process_Discriminant_Expression --
9273 -------------------------------------
9274
9275 procedure Process_Discriminant_Expression
9276 (Expr : Node_Id;
9277 D : Entity_Id)
9278 is
9279 BDT : constant Entity_Id := Base_Type (Etype (D));
9280
9281 begin
9282 -- If this is a discriminant constraint on a partial view, do
9283 -- not generate an overflow on the discriminant expression. The
9284 -- check will be generated when constraining the full view.
9285
9286 if Is_Private_Type (T)
9287 and then Present (Full_View (T))
9288 then
9289 Analyze_And_Resolve (Expr, BDT, Suppress => Overflow_Check);
9290 else
9291 Analyze_And_Resolve (Expr, BDT);
9292 end if;
9293 end Process_Discriminant_Expression;
9294
9295 -- Declarations local to Build_Discriminant_Constraints
9296
9297 Discr : Entity_Id;
9298 E : Entity_Id;
9299 Elist : constant Elist_Id := New_Elmt_List;
9300
9301 Constr : Node_Id;
9302 Expr : Node_Id;
9303 Id : Node_Id;
9304 Position : Nat;
9305 Found : Boolean;
9306
9307 Discrim_Present : Boolean := False;
9308
9309 -- Start of processing for Build_Discriminant_Constraints
9310
9311 begin
9312 -- The following loop will process positional associations only.
9313 -- For a positional association, the (single) discriminant is
9314 -- implicitly specified by position, in textual order (RM 3.7.2).
9315
9316 Discr := First_Discriminant (T);
9317 Constr := First (Constraints (C));
9318 for D in Discr_Expr'Range loop
9319 exit when Nkind (Constr) = N_Discriminant_Association;
9320
9321 if No (Constr) then
9322 Error_Msg_N ("too few discriminants given in constraint", C);
9323 return New_Elmt_List;
9324
9325 elsif Nkind (Constr) = N_Range
9326 or else (Nkind (Constr) = N_Attribute_Reference
9327 and then Attribute_Name (Constr) = Name_Range)
9328 then
9329 Error_Msg_N
9330 ("a range is not a valid discriminant constraint", Constr);
9331 Discr_Expr (D) := Error;
9332
9333 else
9334 Process_Discriminant_Expression (Constr, Discr);
9335 Discr_Expr (D) := Constr;
9336 end if;
9337
9338 Next_Discriminant (Discr);
9339 Next (Constr);
9340 end loop;
9341
9342 if No (Discr) and then Present (Constr) then
9343 Error_Msg_N ("too many discriminants given in constraint", Constr);
9344 return New_Elmt_List;
9345 end if;
9346
9347 -- Named associations can be given in any order, but if both positional
9348 -- and named associations are used in the same discriminant constraint,
9349 -- then positional associations must occur first, at their normal
9350 -- position. Hence once a named association is used, the rest of the
9351 -- discriminant constraint must use only named associations.
9352
9353 while Present (Constr) loop
9354
9355 -- Positional association forbidden after a named association
9356
9357 if Nkind (Constr) /= N_Discriminant_Association then
9358 Error_Msg_N ("positional association follows named one", Constr);
9359 return New_Elmt_List;
9360
9361 -- Otherwise it is a named association
9362
9363 else
9364 -- E records the type of the discriminants in the named
9365 -- association. All the discriminants specified in the same name
9366 -- association must have the same type.
9367
9368 E := Empty;
9369
9370 -- Search the list of discriminants in T to see if the simple name
9371 -- given in the constraint matches any of them.
9372
9373 Id := First (Selector_Names (Constr));
9374 while Present (Id) loop
9375 Found := False;
9376
9377 -- If Original_Discriminant is present, we are processing a
9378 -- generic instantiation and this is an instance node. We need
9379 -- to find the name of the corresponding discriminant in the
9380 -- actual record type T and not the name of the discriminant in
9381 -- the generic formal. Example:
9382
9383 -- generic
9384 -- type G (D : int) is private;
9385 -- package P is
9386 -- subtype W is G (D => 1);
9387 -- end package;
9388 -- type Rec (X : int) is record ... end record;
9389 -- package Q is new P (G => Rec);
9390
9391 -- At the point of the instantiation, formal type G is Rec
9392 -- and therefore when reanalyzing "subtype W is G (D => 1);"
9393 -- which really looks like "subtype W is Rec (D => 1);" at
9394 -- the point of instantiation, we want to find the discriminant
9395 -- that corresponds to D in Rec, i.e. X.
9396
9397 if Present (Original_Discriminant (Id))
9398 and then In_Instance
9399 then
9400 Discr := Find_Corresponding_Discriminant (Id, T);
9401 Found := True;
9402
9403 else
9404 Discr := First_Discriminant (T);
9405 while Present (Discr) loop
9406 if Chars (Discr) = Chars (Id) then
9407 Found := True;
9408 exit;
9409 end if;
9410
9411 Next_Discriminant (Discr);
9412 end loop;
9413
9414 if not Found then
9415 Error_Msg_N ("& does not match any discriminant", Id);
9416 return New_Elmt_List;
9417
9418 -- If the parent type is a generic formal, preserve the
9419 -- name of the discriminant for subsequent instances.
9420 -- see comment at the beginning of this if statement.
9421
9422 elsif Is_Generic_Type (Root_Type (T)) then
9423 Set_Original_Discriminant (Id, Discr);
9424 end if;
9425 end if;
9426
9427 Position := Pos_Of_Discr (T, Discr);
9428
9429 if Present (Discr_Expr (Position)) then
9430 Error_Msg_N ("duplicate constraint for discriminant&", Id);
9431
9432 else
9433 -- Each discriminant specified in the same named association
9434 -- must be associated with a separate copy of the
9435 -- corresponding expression.
9436
9437 if Present (Next (Id)) then
9438 Expr := New_Copy_Tree (Expression (Constr));
9439 Set_Parent (Expr, Parent (Expression (Constr)));
9440 else
9441 Expr := Expression (Constr);
9442 end if;
9443
9444 Discr_Expr (Position) := Expr;
9445 Process_Discriminant_Expression (Expr, Discr);
9446 end if;
9447
9448 -- A discriminant association with more than one discriminant
9449 -- name is only allowed if the named discriminants are all of
9450 -- the same type (RM 3.7.1(8)).
9451
9452 if E = Empty then
9453 E := Base_Type (Etype (Discr));
9454
9455 elsif Base_Type (Etype (Discr)) /= E then
9456 Error_Msg_N
9457 ("all discriminants in an association " &
9458 "must have the same type", Id);
9459 end if;
9460
9461 Next (Id);
9462 end loop;
9463 end if;
9464
9465 Next (Constr);
9466 end loop;
9467
9468 -- A discriminant constraint must provide exactly one value for each
9469 -- discriminant of the type (RM 3.7.1(8)).
9470
9471 for J in Discr_Expr'Range loop
9472 if No (Discr_Expr (J)) then
9473 Error_Msg_N ("too few discriminants given in constraint", C);
9474 return New_Elmt_List;
9475 end if;
9476 end loop;
9477
9478 -- Determine if there are discriminant expressions in the constraint
9479
9480 for J in Discr_Expr'Range loop
9481 if Denotes_Discriminant
9482 (Discr_Expr (J), Check_Concurrent => True)
9483 then
9484 Discrim_Present := True;
9485 end if;
9486 end loop;
9487
9488 -- Build an element list consisting of the expressions given in the
9489 -- discriminant constraint and apply the appropriate checks. The list
9490 -- is constructed after resolving any named discriminant associations
9491 -- and therefore the expressions appear in the textual order of the
9492 -- discriminants.
9493
9494 Discr := First_Discriminant (T);
9495 for J in Discr_Expr'Range loop
9496 if Discr_Expr (J) /= Error then
9497 Append_Elmt (Discr_Expr (J), Elist);
9498
9499 -- If any of the discriminant constraints is given by a
9500 -- discriminant and we are in a derived type declaration we
9501 -- have a discriminant renaming. Establish link between new
9502 -- and old discriminant.
9503
9504 if Denotes_Discriminant (Discr_Expr (J)) then
9505 if Derived_Def then
9506 Set_Corresponding_Discriminant
9507 (Entity (Discr_Expr (J)), Discr);
9508 end if;
9509
9510 -- Force the evaluation of non-discriminant expressions.
9511 -- If we have found a discriminant in the constraint 3.4(26)
9512 -- and 3.8(18) demand that no range checks are performed are
9513 -- after evaluation. If the constraint is for a component
9514 -- definition that has a per-object constraint, expressions are
9515 -- evaluated but not checked either. In all other cases perform
9516 -- a range check.
9517
9518 else
9519 if Discrim_Present then
9520 null;
9521
9522 elsif Nkind (Parent (Parent (Def))) = N_Component_Declaration
9523 and then
9524 Has_Per_Object_Constraint
9525 (Defining_Identifier (Parent (Parent (Def))))
9526 then
9527 null;
9528
9529 elsif Is_Access_Type (Etype (Discr)) then
9530 Apply_Constraint_Check (Discr_Expr (J), Etype (Discr));
9531
9532 else
9533 Apply_Range_Check (Discr_Expr (J), Etype (Discr));
9534 end if;
9535
9536 Force_Evaluation (Discr_Expr (J));
9537 end if;
9538
9539 -- Check that the designated type of an access discriminant's
9540 -- expression is not a class-wide type unless the discriminant's
9541 -- designated type is also class-wide.
9542
9543 if Ekind (Etype (Discr)) = E_Anonymous_Access_Type
9544 and then not Is_Class_Wide_Type
9545 (Designated_Type (Etype (Discr)))
9546 and then Etype (Discr_Expr (J)) /= Any_Type
9547 and then Is_Class_Wide_Type
9548 (Designated_Type (Etype (Discr_Expr (J))))
9549 then
9550 Wrong_Type (Discr_Expr (J), Etype (Discr));
9551
9552 elsif Is_Access_Type (Etype (Discr))
9553 and then not Is_Access_Constant (Etype (Discr))
9554 and then Is_Access_Type (Etype (Discr_Expr (J)))
9555 and then Is_Access_Constant (Etype (Discr_Expr (J)))
9556 then
9557 Error_Msg_NE
9558 ("constraint for discriminant& must be access to variable",
9559 Def, Discr);
9560 end if;
9561 end if;
9562
9563 Next_Discriminant (Discr);
9564 end loop;
9565
9566 return Elist;
9567 end Build_Discriminant_Constraints;
9568
9569 ---------------------------------
9570 -- Build_Discriminated_Subtype --
9571 ---------------------------------
9572
9573 procedure Build_Discriminated_Subtype
9574 (T : Entity_Id;
9575 Def_Id : Entity_Id;
9576 Elist : Elist_Id;
9577 Related_Nod : Node_Id;
9578 For_Access : Boolean := False)
9579 is
9580 Has_Discrs : constant Boolean := Has_Discriminants (T);
9581 Constrained : constant Boolean :=
9582 (Has_Discrs
9583 and then not Is_Empty_Elmt_List (Elist)
9584 and then not Is_Class_Wide_Type (T))
9585 or else Is_Constrained (T);
9586
9587 begin
9588 if Ekind (T) = E_Record_Type then
9589 if For_Access then
9590 Set_Ekind (Def_Id, E_Private_Subtype);
9591 Set_Is_For_Access_Subtype (Def_Id, True);
9592 else
9593 Set_Ekind (Def_Id, E_Record_Subtype);
9594 end if;
9595
9596 -- Inherit preelaboration flag from base, for types for which it
9597 -- may have been set: records, private types, protected types.
9598
9599 Set_Known_To_Have_Preelab_Init
9600 (Def_Id, Known_To_Have_Preelab_Init (T));
9601
9602 elsif Ekind (T) = E_Task_Type then
9603 Set_Ekind (Def_Id, E_Task_Subtype);
9604
9605 elsif Ekind (T) = E_Protected_Type then
9606 Set_Ekind (Def_Id, E_Protected_Subtype);
9607 Set_Known_To_Have_Preelab_Init
9608 (Def_Id, Known_To_Have_Preelab_Init (T));
9609
9610 elsif Is_Private_Type (T) then
9611 Set_Ekind (Def_Id, Subtype_Kind (Ekind (T)));
9612 Set_Known_To_Have_Preelab_Init
9613 (Def_Id, Known_To_Have_Preelab_Init (T));
9614
9615 -- Private subtypes may have private dependents
9616
9617 Set_Private_Dependents (Def_Id, New_Elmt_List);
9618
9619 elsif Is_Class_Wide_Type (T) then
9620 Set_Ekind (Def_Id, E_Class_Wide_Subtype);
9621
9622 else
9623 -- Incomplete type. Attach subtype to list of dependents, to be
9624 -- completed with full view of parent type, unless is it the
9625 -- designated subtype of a record component within an init_proc.
9626 -- This last case arises for a component of an access type whose
9627 -- designated type is incomplete (e.g. a Taft Amendment type).
9628 -- The designated subtype is within an inner scope, and needs no
9629 -- elaboration, because only the access type is needed in the
9630 -- initialization procedure.
9631
9632 Set_Ekind (Def_Id, Ekind (T));
9633
9634 if For_Access and then Within_Init_Proc then
9635 null;
9636 else
9637 Append_Elmt (Def_Id, Private_Dependents (T));
9638 end if;
9639 end if;
9640
9641 Set_Etype (Def_Id, T);
9642 Init_Size_Align (Def_Id);
9643 Set_Has_Discriminants (Def_Id, Has_Discrs);
9644 Set_Is_Constrained (Def_Id, Constrained);
9645
9646 Set_First_Entity (Def_Id, First_Entity (T));
9647 Set_Last_Entity (Def_Id, Last_Entity (T));
9648 Set_Has_Implicit_Dereference
9649 (Def_Id, Has_Implicit_Dereference (T));
9650
9651 -- If the subtype is the completion of a private declaration, there may
9652 -- have been representation clauses for the partial view, and they must
9653 -- be preserved. Build_Derived_Type chains the inherited clauses with
9654 -- the ones appearing on the extension. If this comes from a subtype
9655 -- declaration, all clauses are inherited.
9656
9657 if No (First_Rep_Item (Def_Id)) then
9658 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
9659 end if;
9660
9661 if Is_Tagged_Type (T) then
9662 Set_Is_Tagged_Type (Def_Id);
9663 Set_No_Tagged_Streams_Pragma (Def_Id, No_Tagged_Streams_Pragma (T));
9664 Make_Class_Wide_Type (Def_Id);
9665 end if;
9666
9667 Set_Stored_Constraint (Def_Id, No_Elist);
9668
9669 if Has_Discrs then
9670 Set_Discriminant_Constraint (Def_Id, Elist);
9671 Set_Stored_Constraint_From_Discriminant_Constraint (Def_Id);
9672 end if;
9673
9674 if Is_Tagged_Type (T) then
9675
9676 -- Ada 2005 (AI-251): In case of concurrent types we inherit the
9677 -- concurrent record type (which has the list of primitive
9678 -- operations).
9679
9680 if Ada_Version >= Ada_2005
9681 and then Is_Concurrent_Type (T)
9682 then
9683 Set_Corresponding_Record_Type (Def_Id,
9684 Corresponding_Record_Type (T));
9685 else
9686 Set_Direct_Primitive_Operations (Def_Id,
9687 Direct_Primitive_Operations (T));
9688 end if;
9689
9690 Set_Is_Abstract_Type (Def_Id, Is_Abstract_Type (T));
9691 end if;
9692
9693 -- Subtypes introduced by component declarations do not need to be
9694 -- marked as delayed, and do not get freeze nodes, because the semantics
9695 -- verifies that the parents of the subtypes are frozen before the
9696 -- enclosing record is frozen.
9697
9698 if not Is_Type (Scope (Def_Id)) then
9699 Set_Depends_On_Private (Def_Id, Depends_On_Private (T));
9700
9701 if Is_Private_Type (T)
9702 and then Present (Full_View (T))
9703 then
9704 Conditional_Delay (Def_Id, Full_View (T));
9705 else
9706 Conditional_Delay (Def_Id, T);
9707 end if;
9708 end if;
9709
9710 if Is_Record_Type (T) then
9711 Set_Is_Limited_Record (Def_Id, Is_Limited_Record (T));
9712
9713 if Has_Discrs
9714 and then not Is_Empty_Elmt_List (Elist)
9715 and then not For_Access
9716 then
9717 Create_Constrained_Components (Def_Id, Related_Nod, T, Elist);
9718 elsif not For_Access then
9719 Set_Cloned_Subtype (Def_Id, T);
9720 end if;
9721 end if;
9722 end Build_Discriminated_Subtype;
9723
9724 ---------------------------
9725 -- Build_Itype_Reference --
9726 ---------------------------
9727
9728 procedure Build_Itype_Reference
9729 (Ityp : Entity_Id;
9730 Nod : Node_Id)
9731 is
9732 IR : constant Node_Id := Make_Itype_Reference (Sloc (Nod));
9733 begin
9734
9735 -- Itype references are only created for use by the back-end
9736
9737 if Inside_A_Generic then
9738 return;
9739 else
9740 Set_Itype (IR, Ityp);
9741 Insert_After (Nod, IR);
9742 end if;
9743 end Build_Itype_Reference;
9744
9745 ------------------------
9746 -- Build_Scalar_Bound --
9747 ------------------------
9748
9749 function Build_Scalar_Bound
9750 (Bound : Node_Id;
9751 Par_T : Entity_Id;
9752 Der_T : Entity_Id) return Node_Id
9753 is
9754 New_Bound : Entity_Id;
9755
9756 begin
9757 -- Note: not clear why this is needed, how can the original bound
9758 -- be unanalyzed at this point? and if it is, what business do we
9759 -- have messing around with it? and why is the base type of the
9760 -- parent type the right type for the resolution. It probably is
9761 -- not. It is OK for the new bound we are creating, but not for
9762 -- the old one??? Still if it never happens, no problem.
9763
9764 Analyze_And_Resolve (Bound, Base_Type (Par_T));
9765
9766 if Nkind_In (Bound, N_Integer_Literal, N_Real_Literal) then
9767 New_Bound := New_Copy (Bound);
9768 Set_Etype (New_Bound, Der_T);
9769 Set_Analyzed (New_Bound);
9770
9771 elsif Is_Entity_Name (Bound) then
9772 New_Bound := OK_Convert_To (Der_T, New_Copy (Bound));
9773
9774 -- The following is almost certainly wrong. What business do we have
9775 -- relocating a node (Bound) that is presumably still attached to
9776 -- the tree elsewhere???
9777
9778 else
9779 New_Bound := OK_Convert_To (Der_T, Relocate_Node (Bound));
9780 end if;
9781
9782 Set_Etype (New_Bound, Der_T);
9783 return New_Bound;
9784 end Build_Scalar_Bound;
9785
9786 --------------------------------
9787 -- Build_Underlying_Full_View --
9788 --------------------------------
9789
9790 procedure Build_Underlying_Full_View
9791 (N : Node_Id;
9792 Typ : Entity_Id;
9793 Par : Entity_Id)
9794 is
9795 Loc : constant Source_Ptr := Sloc (N);
9796 Subt : constant Entity_Id :=
9797 Make_Defining_Identifier
9798 (Loc, New_External_Name (Chars (Typ), 'S'));
9799
9800 Constr : Node_Id;
9801 Indic : Node_Id;
9802 C : Node_Id;
9803 Id : Node_Id;
9804
9805 procedure Set_Discriminant_Name (Id : Node_Id);
9806 -- If the derived type has discriminants, they may rename discriminants
9807 -- of the parent. When building the full view of the parent, we need to
9808 -- recover the names of the original discriminants if the constraint is
9809 -- given by named associations.
9810
9811 ---------------------------
9812 -- Set_Discriminant_Name --
9813 ---------------------------
9814
9815 procedure Set_Discriminant_Name (Id : Node_Id) is
9816 Disc : Entity_Id;
9817
9818 begin
9819 Set_Original_Discriminant (Id, Empty);
9820
9821 if Has_Discriminants (Typ) then
9822 Disc := First_Discriminant (Typ);
9823 while Present (Disc) loop
9824 if Chars (Disc) = Chars (Id)
9825 and then Present (Corresponding_Discriminant (Disc))
9826 then
9827 Set_Chars (Id, Chars (Corresponding_Discriminant (Disc)));
9828 end if;
9829 Next_Discriminant (Disc);
9830 end loop;
9831 end if;
9832 end Set_Discriminant_Name;
9833
9834 -- Start of processing for Build_Underlying_Full_View
9835
9836 begin
9837 if Nkind (N) = N_Full_Type_Declaration then
9838 Constr := Constraint (Subtype_Indication (Type_Definition (N)));
9839
9840 elsif Nkind (N) = N_Subtype_Declaration then
9841 Constr := New_Copy_Tree (Constraint (Subtype_Indication (N)));
9842
9843 elsif Nkind (N) = N_Component_Declaration then
9844 Constr :=
9845 New_Copy_Tree
9846 (Constraint (Subtype_Indication (Component_Definition (N))));
9847
9848 else
9849 raise Program_Error;
9850 end if;
9851
9852 C := First (Constraints (Constr));
9853 while Present (C) loop
9854 if Nkind (C) = N_Discriminant_Association then
9855 Id := First (Selector_Names (C));
9856 while Present (Id) loop
9857 Set_Discriminant_Name (Id);
9858 Next (Id);
9859 end loop;
9860 end if;
9861
9862 Next (C);
9863 end loop;
9864
9865 Indic :=
9866 Make_Subtype_Declaration (Loc,
9867 Defining_Identifier => Subt,
9868 Subtype_Indication =>
9869 Make_Subtype_Indication (Loc,
9870 Subtype_Mark => New_Occurrence_Of (Par, Loc),
9871 Constraint => New_Copy_Tree (Constr)));
9872
9873 -- If this is a component subtype for an outer itype, it is not
9874 -- a list member, so simply set the parent link for analysis: if
9875 -- the enclosing type does not need to be in a declarative list,
9876 -- neither do the components.
9877
9878 if Is_List_Member (N)
9879 and then Nkind (N) /= N_Component_Declaration
9880 then
9881 Insert_Before (N, Indic);
9882 else
9883 Set_Parent (Indic, Parent (N));
9884 end if;
9885
9886 Analyze (Indic);
9887 Set_Underlying_Full_View (Typ, Full_View (Subt));
9888 end Build_Underlying_Full_View;
9889
9890 -------------------------------
9891 -- Check_Abstract_Overriding --
9892 -------------------------------
9893
9894 procedure Check_Abstract_Overriding (T : Entity_Id) is
9895 Alias_Subp : Entity_Id;
9896 Elmt : Elmt_Id;
9897 Op_List : Elist_Id;
9898 Subp : Entity_Id;
9899 Type_Def : Node_Id;
9900
9901 procedure Check_Pragma_Implemented (Subp : Entity_Id);
9902 -- Ada 2012 (AI05-0030): Subprogram Subp overrides an interface routine
9903 -- which has pragma Implemented already set. Check whether Subp's entity
9904 -- kind conforms to the implementation kind of the overridden routine.
9905
9906 procedure Check_Pragma_Implemented
9907 (Subp : Entity_Id;
9908 Iface_Subp : Entity_Id);
9909 -- Ada 2012 (AI05-0030): Subprogram Subp overrides interface routine
9910 -- Iface_Subp and both entities have pragma Implemented already set on
9911 -- them. Check whether the two implementation kinds are conforming.
9912
9913 procedure Inherit_Pragma_Implemented
9914 (Subp : Entity_Id;
9915 Iface_Subp : Entity_Id);
9916 -- Ada 2012 (AI05-0030): Interface primitive Subp overrides interface
9917 -- subprogram Iface_Subp which has been marked by pragma Implemented.
9918 -- Propagate the implementation kind of Iface_Subp to Subp.
9919
9920 ------------------------------
9921 -- Check_Pragma_Implemented --
9922 ------------------------------
9923
9924 procedure Check_Pragma_Implemented (Subp : Entity_Id) is
9925 Iface_Alias : constant Entity_Id := Interface_Alias (Subp);
9926 Impl_Kind : constant Name_Id := Implementation_Kind (Iface_Alias);
9927 Subp_Alias : constant Entity_Id := Alias (Subp);
9928 Contr_Typ : Entity_Id;
9929 Impl_Subp : Entity_Id;
9930
9931 begin
9932 -- Subp must have an alias since it is a hidden entity used to link
9933 -- an interface subprogram to its overriding counterpart.
9934
9935 pragma Assert (Present (Subp_Alias));
9936
9937 -- Handle aliases to synchronized wrappers
9938
9939 Impl_Subp := Subp_Alias;
9940
9941 if Is_Primitive_Wrapper (Impl_Subp) then
9942 Impl_Subp := Wrapped_Entity (Impl_Subp);
9943 end if;
9944
9945 -- Extract the type of the controlling formal
9946
9947 Contr_Typ := Etype (First_Formal (Subp_Alias));
9948
9949 if Is_Concurrent_Record_Type (Contr_Typ) then
9950 Contr_Typ := Corresponding_Concurrent_Type (Contr_Typ);
9951 end if;
9952
9953 -- An interface subprogram whose implementation kind is By_Entry must
9954 -- be implemented by an entry.
9955
9956 if Impl_Kind = Name_By_Entry
9957 and then Ekind (Impl_Subp) /= E_Entry
9958 then
9959 Error_Msg_Node_2 := Iface_Alias;
9960 Error_Msg_NE
9961 ("type & must implement abstract subprogram & with an entry",
9962 Subp_Alias, Contr_Typ);
9963
9964 elsif Impl_Kind = Name_By_Protected_Procedure then
9965
9966 -- An interface subprogram whose implementation kind is By_
9967 -- Protected_Procedure cannot be implemented by a primitive
9968 -- procedure of a task type.
9969
9970 if Ekind (Contr_Typ) /= E_Protected_Type then
9971 Error_Msg_Node_2 := Contr_Typ;
9972 Error_Msg_NE
9973 ("interface subprogram & cannot be implemented by a " &
9974 "primitive procedure of task type &", Subp_Alias,
9975 Iface_Alias);
9976
9977 -- An interface subprogram whose implementation kind is By_
9978 -- Protected_Procedure must be implemented by a procedure.
9979
9980 elsif Ekind (Impl_Subp) /= E_Procedure then
9981 Error_Msg_Node_2 := Iface_Alias;
9982 Error_Msg_NE
9983 ("type & must implement abstract subprogram & with a " &
9984 "procedure", Subp_Alias, Contr_Typ);
9985
9986 elsif Present (Get_Rep_Pragma (Impl_Subp, Name_Implemented))
9987 and then Implementation_Kind (Impl_Subp) /= Impl_Kind
9988 then
9989 Error_Msg_Name_1 := Impl_Kind;
9990 Error_Msg_N
9991 ("overriding operation& must have synchronization%",
9992 Subp_Alias);
9993 end if;
9994
9995 -- If primitive has Optional synchronization, overriding operation
9996 -- must match if it has an explicit synchronization..
9997
9998 elsif Present (Get_Rep_Pragma (Impl_Subp, Name_Implemented))
9999 and then Implementation_Kind (Impl_Subp) /= Impl_Kind
10000 then
10001 Error_Msg_Name_1 := Impl_Kind;
10002 Error_Msg_N
10003 ("overriding operation& must have syncrhonization%",
10004 Subp_Alias);
10005 end if;
10006 end Check_Pragma_Implemented;
10007
10008 ------------------------------
10009 -- Check_Pragma_Implemented --
10010 ------------------------------
10011
10012 procedure Check_Pragma_Implemented
10013 (Subp : Entity_Id;
10014 Iface_Subp : Entity_Id)
10015 is
10016 Iface_Kind : constant Name_Id := Implementation_Kind (Iface_Subp);
10017 Subp_Kind : constant Name_Id := Implementation_Kind (Subp);
10018
10019 begin
10020 -- Ada 2012 (AI05-0030): The implementation kinds of an overridden
10021 -- and overriding subprogram are different. In general this is an
10022 -- error except when the implementation kind of the overridden
10023 -- subprograms is By_Any or Optional.
10024
10025 if Iface_Kind /= Subp_Kind
10026 and then Iface_Kind /= Name_By_Any
10027 and then Iface_Kind /= Name_Optional
10028 then
10029 if Iface_Kind = Name_By_Entry then
10030 Error_Msg_N
10031 ("incompatible implementation kind, overridden subprogram " &
10032 "is marked By_Entry", Subp);
10033 else
10034 Error_Msg_N
10035 ("incompatible implementation kind, overridden subprogram " &
10036 "is marked By_Protected_Procedure", Subp);
10037 end if;
10038 end if;
10039 end Check_Pragma_Implemented;
10040
10041 --------------------------------
10042 -- Inherit_Pragma_Implemented --
10043 --------------------------------
10044
10045 procedure Inherit_Pragma_Implemented
10046 (Subp : Entity_Id;
10047 Iface_Subp : Entity_Id)
10048 is
10049 Iface_Kind : constant Name_Id := Implementation_Kind (Iface_Subp);
10050 Loc : constant Source_Ptr := Sloc (Subp);
10051 Impl_Prag : Node_Id;
10052
10053 begin
10054 -- Since the implementation kind is stored as a representation item
10055 -- rather than a flag, create a pragma node.
10056
10057 Impl_Prag :=
10058 Make_Pragma (Loc,
10059 Chars => Name_Implemented,
10060 Pragma_Argument_Associations => New_List (
10061 Make_Pragma_Argument_Association (Loc,
10062 Expression => New_Occurrence_Of (Subp, Loc)),
10063
10064 Make_Pragma_Argument_Association (Loc,
10065 Expression => Make_Identifier (Loc, Iface_Kind))));
10066
10067 -- The pragma doesn't need to be analyzed because it is internally
10068 -- built. It is safe to directly register it as a rep item since we
10069 -- are only interested in the characters of the implementation kind.
10070
10071 Record_Rep_Item (Subp, Impl_Prag);
10072 end Inherit_Pragma_Implemented;
10073
10074 -- Start of processing for Check_Abstract_Overriding
10075
10076 begin
10077 Op_List := Primitive_Operations (T);
10078
10079 -- Loop to check primitive operations
10080
10081 Elmt := First_Elmt (Op_List);
10082 while Present (Elmt) loop
10083 Subp := Node (Elmt);
10084 Alias_Subp := Alias (Subp);
10085
10086 -- Inherited subprograms are identified by the fact that they do not
10087 -- come from source, and the associated source location is the
10088 -- location of the first subtype of the derived type.
10089
10090 -- Ada 2005 (AI-228): Apply the rules of RM-3.9.3(6/2) for
10091 -- subprograms that "require overriding".
10092
10093 -- Special exception, do not complain about failure to override the
10094 -- stream routines _Input and _Output, as well as the primitive
10095 -- operations used in dispatching selects since we always provide
10096 -- automatic overridings for these subprograms.
10097
10098 -- The partial view of T may have been a private extension, for
10099 -- which inherited functions dispatching on result are abstract.
10100 -- If the full view is a null extension, there is no need for
10101 -- overriding in Ada 2005, but wrappers need to be built for them
10102 -- (see exp_ch3, Build_Controlling_Function_Wrappers).
10103
10104 if Is_Null_Extension (T)
10105 and then Has_Controlling_Result (Subp)
10106 and then Ada_Version >= Ada_2005
10107 and then Present (Alias_Subp)
10108 and then not Comes_From_Source (Subp)
10109 and then not Is_Abstract_Subprogram (Alias_Subp)
10110 and then not Is_Access_Type (Etype (Subp))
10111 then
10112 null;
10113
10114 -- Ada 2005 (AI-251): Internal entities of interfaces need no
10115 -- processing because this check is done with the aliased
10116 -- entity
10117
10118 elsif Present (Interface_Alias (Subp)) then
10119 null;
10120
10121 elsif (Is_Abstract_Subprogram (Subp)
10122 or else Requires_Overriding (Subp)
10123 or else
10124 (Has_Controlling_Result (Subp)
10125 and then Present (Alias_Subp)
10126 and then not Comes_From_Source (Subp)
10127 and then Sloc (Subp) = Sloc (First_Subtype (T))))
10128 and then not Is_TSS (Subp, TSS_Stream_Input)
10129 and then not Is_TSS (Subp, TSS_Stream_Output)
10130 and then not Is_Abstract_Type (T)
10131 and then not Is_Predefined_Interface_Primitive (Subp)
10132
10133 -- Ada 2005 (AI-251): Do not consider hidden entities associated
10134 -- with abstract interface types because the check will be done
10135 -- with the aliased entity (otherwise we generate a duplicated
10136 -- error message).
10137
10138 and then not Present (Interface_Alias (Subp))
10139 then
10140 if Present (Alias_Subp) then
10141
10142 -- Only perform the check for a derived subprogram when the
10143 -- type has an explicit record extension. This avoids incorrect
10144 -- flagging of abstract subprograms for the case of a type
10145 -- without an extension that is derived from a formal type
10146 -- with a tagged actual (can occur within a private part).
10147
10148 -- Ada 2005 (AI-391): In the case of an inherited function with
10149 -- a controlling result of the type, the rule does not apply if
10150 -- the type is a null extension (unless the parent function
10151 -- itself is abstract, in which case the function must still be
10152 -- be overridden). The expander will generate an overriding
10153 -- wrapper function calling the parent subprogram (see
10154 -- Exp_Ch3.Make_Controlling_Wrapper_Functions).
10155
10156 Type_Def := Type_Definition (Parent (T));
10157
10158 if Nkind (Type_Def) = N_Derived_Type_Definition
10159 and then Present (Record_Extension_Part (Type_Def))
10160 and then
10161 (Ada_Version < Ada_2005
10162 or else not Is_Null_Extension (T)
10163 or else Ekind (Subp) = E_Procedure
10164 or else not Has_Controlling_Result (Subp)
10165 or else Is_Abstract_Subprogram (Alias_Subp)
10166 or else Requires_Overriding (Subp)
10167 or else Is_Access_Type (Etype (Subp)))
10168 then
10169 -- Avoid reporting error in case of abstract predefined
10170 -- primitive inherited from interface type because the
10171 -- body of internally generated predefined primitives
10172 -- of tagged types are generated later by Freeze_Type
10173
10174 if Is_Interface (Root_Type (T))
10175 and then Is_Abstract_Subprogram (Subp)
10176 and then Is_Predefined_Dispatching_Operation (Subp)
10177 and then not Comes_From_Source (Ultimate_Alias (Subp))
10178 then
10179 null;
10180
10181 -- A null extension is not obliged to override an inherited
10182 -- procedure subject to pragma Extensions_Visible with value
10183 -- False and at least one controlling OUT parameter
10184 -- (SPARK RM 6.1.7(6)).
10185
10186 elsif Is_Null_Extension (T)
10187 and then Is_EVF_Procedure (Subp)
10188 then
10189 null;
10190
10191 else
10192 Error_Msg_NE
10193 ("type must be declared abstract or & overridden",
10194 T, Subp);
10195
10196 -- Traverse the whole chain of aliased subprograms to
10197 -- complete the error notification. This is especially
10198 -- useful for traceability of the chain of entities when
10199 -- the subprogram corresponds with an interface
10200 -- subprogram (which may be defined in another package).
10201
10202 if Present (Alias_Subp) then
10203 declare
10204 E : Entity_Id;
10205
10206 begin
10207 E := Subp;
10208 while Present (Alias (E)) loop
10209
10210 -- Avoid reporting redundant errors on entities
10211 -- inherited from interfaces
10212
10213 if Sloc (E) /= Sloc (T) then
10214 Error_Msg_Sloc := Sloc (E);
10215 Error_Msg_NE
10216 ("\& has been inherited #", T, Subp);
10217 end if;
10218
10219 E := Alias (E);
10220 end loop;
10221
10222 Error_Msg_Sloc := Sloc (E);
10223
10224 -- AI05-0068: report if there is an overriding
10225 -- non-abstract subprogram that is invisible.
10226
10227 if Is_Hidden (E)
10228 and then not Is_Abstract_Subprogram (E)
10229 then
10230 Error_Msg_NE
10231 ("\& subprogram# is not visible",
10232 T, Subp);
10233
10234 -- Clarify the case where a non-null extension must
10235 -- override inherited procedure subject to pragma
10236 -- Extensions_Visible with value False and at least
10237 -- one controlling OUT param.
10238
10239 elsif Is_EVF_Procedure (E) then
10240 Error_Msg_NE
10241 ("\& # is subject to Extensions_Visible False",
10242 T, Subp);
10243
10244 else
10245 Error_Msg_NE
10246 ("\& has been inherited from subprogram #",
10247 T, Subp);
10248 end if;
10249 end;
10250 end if;
10251 end if;
10252
10253 -- Ada 2005 (AI-345): Protected or task type implementing
10254 -- abstract interfaces.
10255
10256 elsif Is_Concurrent_Record_Type (T)
10257 and then Present (Interfaces (T))
10258 then
10259 -- There is no need to check here RM 9.4(11.9/3) since we
10260 -- are processing the corresponding record type and the
10261 -- mode of the overriding subprograms was verified by
10262 -- Check_Conformance when the corresponding concurrent
10263 -- type declaration was analyzed.
10264
10265 Error_Msg_NE
10266 ("interface subprogram & must be overridden", T, Subp);
10267
10268 -- Examine primitive operations of synchronized type to find
10269 -- homonyms that have the wrong profile.
10270
10271 declare
10272 Prim : Entity_Id;
10273
10274 begin
10275 Prim := First_Entity (Corresponding_Concurrent_Type (T));
10276 while Present (Prim) loop
10277 if Chars (Prim) = Chars (Subp) then
10278 Error_Msg_NE
10279 ("profile is not type conformant with prefixed "
10280 & "view profile of inherited operation&",
10281 Prim, Subp);
10282 end if;
10283
10284 Next_Entity (Prim);
10285 end loop;
10286 end;
10287 end if;
10288
10289 else
10290 Error_Msg_Node_2 := T;
10291 Error_Msg_N
10292 ("abstract subprogram& not allowed for type&", Subp);
10293
10294 -- Also post unconditional warning on the type (unconditional
10295 -- so that if there are more than one of these cases, we get
10296 -- them all, and not just the first one).
10297
10298 Error_Msg_Node_2 := Subp;
10299 Error_Msg_N ("nonabstract type& has abstract subprogram&!", T);
10300 end if;
10301
10302 -- A subprogram subject to pragma Extensions_Visible with value
10303 -- "True" cannot override a subprogram subject to the same pragma
10304 -- with value "False" (SPARK RM 6.1.7(5)).
10305
10306 elsif Extensions_Visible_Status (Subp) = Extensions_Visible_True
10307 and then Present (Overridden_Operation (Subp))
10308 and then Extensions_Visible_Status (Overridden_Operation (Subp)) =
10309 Extensions_Visible_False
10310 then
10311 Error_Msg_Sloc := Sloc (Overridden_Operation (Subp));
10312 Error_Msg_N
10313 ("subprogram & with Extensions_Visible True cannot override "
10314 & "subprogram # with Extensions_Visible False", Subp);
10315 end if;
10316
10317 -- Ada 2012 (AI05-0030): Perform checks related to pragma Implemented
10318
10319 -- Subp is an expander-generated procedure which maps an interface
10320 -- alias to a protected wrapper. The interface alias is flagged by
10321 -- pragma Implemented. Ensure that Subp is a procedure when the
10322 -- implementation kind is By_Protected_Procedure or an entry when
10323 -- By_Entry.
10324
10325 if Ada_Version >= Ada_2012
10326 and then Is_Hidden (Subp)
10327 and then Present (Interface_Alias (Subp))
10328 and then Has_Rep_Pragma (Interface_Alias (Subp), Name_Implemented)
10329 then
10330 Check_Pragma_Implemented (Subp);
10331 end if;
10332
10333 -- Subp is an interface primitive which overrides another interface
10334 -- primitive marked with pragma Implemented.
10335
10336 if Ada_Version >= Ada_2012
10337 and then Present (Overridden_Operation (Subp))
10338 and then Has_Rep_Pragma
10339 (Overridden_Operation (Subp), Name_Implemented)
10340 then
10341 -- If the overriding routine is also marked by Implemented, check
10342 -- that the two implementation kinds are conforming.
10343
10344 if Has_Rep_Pragma (Subp, Name_Implemented) then
10345 Check_Pragma_Implemented
10346 (Subp => Subp,
10347 Iface_Subp => Overridden_Operation (Subp));
10348
10349 -- Otherwise the overriding routine inherits the implementation
10350 -- kind from the overridden subprogram.
10351
10352 else
10353 Inherit_Pragma_Implemented
10354 (Subp => Subp,
10355 Iface_Subp => Overridden_Operation (Subp));
10356 end if;
10357 end if;
10358
10359 -- If the operation is a wrapper for a synchronized primitive, it
10360 -- may be called indirectly through a dispatching select. We assume
10361 -- that it will be referenced elsewhere indirectly, and suppress
10362 -- warnings about an unused entity.
10363
10364 if Is_Primitive_Wrapper (Subp)
10365 and then Present (Wrapped_Entity (Subp))
10366 then
10367 Set_Referenced (Wrapped_Entity (Subp));
10368 end if;
10369
10370 Next_Elmt (Elmt);
10371 end loop;
10372 end Check_Abstract_Overriding;
10373
10374 ------------------------------------------------
10375 -- Check_Access_Discriminant_Requires_Limited --
10376 ------------------------------------------------
10377
10378 procedure Check_Access_Discriminant_Requires_Limited
10379 (D : Node_Id;
10380 Loc : Node_Id)
10381 is
10382 begin
10383 -- A discriminant_specification for an access discriminant shall appear
10384 -- only in the declaration for a task or protected type, or for a type
10385 -- with the reserved word 'limited' in its definition or in one of its
10386 -- ancestors (RM 3.7(10)).
10387
10388 -- AI-0063: The proper condition is that type must be immutably limited,
10389 -- or else be a partial view.
10390
10391 if Nkind (Discriminant_Type (D)) = N_Access_Definition then
10392 if Is_Limited_View (Current_Scope)
10393 or else
10394 (Nkind (Parent (Current_Scope)) = N_Private_Type_Declaration
10395 and then Limited_Present (Parent (Current_Scope)))
10396 then
10397 null;
10398
10399 else
10400 Error_Msg_N
10401 ("access discriminants allowed only for limited types", Loc);
10402 end if;
10403 end if;
10404 end Check_Access_Discriminant_Requires_Limited;
10405
10406 -----------------------------------
10407 -- Check_Aliased_Component_Types --
10408 -----------------------------------
10409
10410 procedure Check_Aliased_Component_Types (T : Entity_Id) is
10411 C : Entity_Id;
10412
10413 begin
10414 -- ??? Also need to check components of record extensions, but not
10415 -- components of protected types (which are always limited).
10416
10417 -- Ada 2005: AI-363 relaxes this rule, to allow heap objects of such
10418 -- types to be unconstrained. This is safe because it is illegal to
10419 -- create access subtypes to such types with explicit discriminant
10420 -- constraints.
10421
10422 if not Is_Limited_Type (T) then
10423 if Ekind (T) = E_Record_Type then
10424 C := First_Component (T);
10425 while Present (C) loop
10426 if Is_Aliased (C)
10427 and then Has_Discriminants (Etype (C))
10428 and then not Is_Constrained (Etype (C))
10429 and then not In_Instance_Body
10430 and then Ada_Version < Ada_2005
10431 then
10432 Error_Msg_N
10433 ("aliased component must be constrained (RM 3.6(11))",
10434 C);
10435 end if;
10436
10437 Next_Component (C);
10438 end loop;
10439
10440 elsif Ekind (T) = E_Array_Type then
10441 if Has_Aliased_Components (T)
10442 and then Has_Discriminants (Component_Type (T))
10443 and then not Is_Constrained (Component_Type (T))
10444 and then not In_Instance_Body
10445 and then Ada_Version < Ada_2005
10446 then
10447 Error_Msg_N
10448 ("aliased component type must be constrained (RM 3.6(11))",
10449 T);
10450 end if;
10451 end if;
10452 end if;
10453 end Check_Aliased_Component_Types;
10454
10455 ---------------------------------------
10456 -- Check_Anonymous_Access_Components --
10457 ---------------------------------------
10458
10459 procedure Check_Anonymous_Access_Components
10460 (Typ_Decl : Node_Id;
10461 Typ : Entity_Id;
10462 Prev : Entity_Id;
10463 Comp_List : Node_Id)
10464 is
10465 Loc : constant Source_Ptr := Sloc (Typ_Decl);
10466 Anon_Access : Entity_Id;
10467 Acc_Def : Node_Id;
10468 Comp : Node_Id;
10469 Comp_Def : Node_Id;
10470 Decl : Node_Id;
10471 Type_Def : Node_Id;
10472
10473 procedure Build_Incomplete_Type_Declaration;
10474 -- If the record type contains components that include an access to the
10475 -- current record, then create an incomplete type declaration for the
10476 -- record, to be used as the designated type of the anonymous access.
10477 -- This is done only once, and only if there is no previous partial
10478 -- view of the type.
10479
10480 function Designates_T (Subt : Node_Id) return Boolean;
10481 -- Check whether a node designates the enclosing record type, or 'Class
10482 -- of that type
10483
10484 function Mentions_T (Acc_Def : Node_Id) return Boolean;
10485 -- Check whether an access definition includes a reference to
10486 -- the enclosing record type. The reference can be a subtype mark
10487 -- in the access definition itself, a 'Class attribute reference, or
10488 -- recursively a reference appearing in a parameter specification
10489 -- or result definition of an access_to_subprogram definition.
10490
10491 --------------------------------------
10492 -- Build_Incomplete_Type_Declaration --
10493 --------------------------------------
10494
10495 procedure Build_Incomplete_Type_Declaration is
10496 Decl : Node_Id;
10497 Inc_T : Entity_Id;
10498 H : Entity_Id;
10499
10500 -- Is_Tagged indicates whether the type is tagged. It is tagged if
10501 -- it's "is new ... with record" or else "is tagged record ...".
10502
10503 Is_Tagged : constant Boolean :=
10504 (Nkind (Type_Definition (Typ_Decl)) = N_Derived_Type_Definition
10505 and then
10506 Present (Record_Extension_Part (Type_Definition (Typ_Decl))))
10507 or else
10508 (Nkind (Type_Definition (Typ_Decl)) = N_Record_Definition
10509 and then Tagged_Present (Type_Definition (Typ_Decl)));
10510
10511 begin
10512 -- If there is a previous partial view, no need to create a new one
10513 -- If the partial view, given by Prev, is incomplete, If Prev is
10514 -- a private declaration, full declaration is flagged accordingly.
10515
10516 if Prev /= Typ then
10517 if Is_Tagged then
10518 Make_Class_Wide_Type (Prev);
10519 Set_Class_Wide_Type (Typ, Class_Wide_Type (Prev));
10520 Set_Etype (Class_Wide_Type (Typ), Typ);
10521 end if;
10522
10523 return;
10524
10525 elsif Has_Private_Declaration (Typ) then
10526
10527 -- If we refer to T'Class inside T, and T is the completion of a
10528 -- private type, then make sure the class-wide type exists.
10529
10530 if Is_Tagged then
10531 Make_Class_Wide_Type (Typ);
10532 end if;
10533
10534 return;
10535
10536 -- If there was a previous anonymous access type, the incomplete
10537 -- type declaration will have been created already.
10538
10539 elsif Present (Current_Entity (Typ))
10540 and then Ekind (Current_Entity (Typ)) = E_Incomplete_Type
10541 and then Full_View (Current_Entity (Typ)) = Typ
10542 then
10543 if Is_Tagged
10544 and then Comes_From_Source (Current_Entity (Typ))
10545 and then not Is_Tagged_Type (Current_Entity (Typ))
10546 then
10547 Make_Class_Wide_Type (Typ);
10548 Error_Msg_N
10549 ("incomplete view of tagged type should be declared tagged??",
10550 Parent (Current_Entity (Typ)));
10551 end if;
10552 return;
10553
10554 else
10555 Inc_T := Make_Defining_Identifier (Loc, Chars (Typ));
10556 Decl := Make_Incomplete_Type_Declaration (Loc, Inc_T);
10557
10558 -- Type has already been inserted into the current scope. Remove
10559 -- it, and add incomplete declaration for type, so that subsequent
10560 -- anonymous access types can use it. The entity is unchained from
10561 -- the homonym list and from immediate visibility. After analysis,
10562 -- the entity in the incomplete declaration becomes immediately
10563 -- visible in the record declaration that follows.
10564
10565 H := Current_Entity (Typ);
10566
10567 if H = Typ then
10568 Set_Name_Entity_Id (Chars (Typ), Homonym (Typ));
10569 else
10570 while Present (H)
10571 and then Homonym (H) /= Typ
10572 loop
10573 H := Homonym (Typ);
10574 end loop;
10575
10576 Set_Homonym (H, Homonym (Typ));
10577 end if;
10578
10579 Insert_Before (Typ_Decl, Decl);
10580 Analyze (Decl);
10581 Set_Full_View (Inc_T, Typ);
10582
10583 if Is_Tagged then
10584
10585 -- Create a common class-wide type for both views, and set the
10586 -- Etype of the class-wide type to the full view.
10587
10588 Make_Class_Wide_Type (Inc_T);
10589 Set_Class_Wide_Type (Typ, Class_Wide_Type (Inc_T));
10590 Set_Etype (Class_Wide_Type (Typ), Typ);
10591 end if;
10592 end if;
10593 end Build_Incomplete_Type_Declaration;
10594
10595 ------------------
10596 -- Designates_T --
10597 ------------------
10598
10599 function Designates_T (Subt : Node_Id) return Boolean is
10600 Type_Id : constant Name_Id := Chars (Typ);
10601
10602 function Names_T (Nam : Node_Id) return Boolean;
10603 -- The record type has not been introduced in the current scope
10604 -- yet, so we must examine the name of the type itself, either
10605 -- an identifier T, or an expanded name of the form P.T, where
10606 -- P denotes the current scope.
10607
10608 -------------
10609 -- Names_T --
10610 -------------
10611
10612 function Names_T (Nam : Node_Id) return Boolean is
10613 begin
10614 if Nkind (Nam) = N_Identifier then
10615 return Chars (Nam) = Type_Id;
10616
10617 elsif Nkind (Nam) = N_Selected_Component then
10618 if Chars (Selector_Name (Nam)) = Type_Id then
10619 if Nkind (Prefix (Nam)) = N_Identifier then
10620 return Chars (Prefix (Nam)) = Chars (Current_Scope);
10621
10622 elsif Nkind (Prefix (Nam)) = N_Selected_Component then
10623 return Chars (Selector_Name (Prefix (Nam))) =
10624 Chars (Current_Scope);
10625 else
10626 return False;
10627 end if;
10628
10629 else
10630 return False;
10631 end if;
10632
10633 else
10634 return False;
10635 end if;
10636 end Names_T;
10637
10638 -- Start of processing for Designates_T
10639
10640 begin
10641 if Nkind (Subt) = N_Identifier then
10642 return Chars (Subt) = Type_Id;
10643
10644 -- Reference can be through an expanded name which has not been
10645 -- analyzed yet, and which designates enclosing scopes.
10646
10647 elsif Nkind (Subt) = N_Selected_Component then
10648 if Names_T (Subt) then
10649 return True;
10650
10651 -- Otherwise it must denote an entity that is already visible.
10652 -- The access definition may name a subtype of the enclosing
10653 -- type, if there is a previous incomplete declaration for it.
10654
10655 else
10656 Find_Selected_Component (Subt);
10657 return
10658 Is_Entity_Name (Subt)
10659 and then Scope (Entity (Subt)) = Current_Scope
10660 and then
10661 (Chars (Base_Type (Entity (Subt))) = Type_Id
10662 or else
10663 (Is_Class_Wide_Type (Entity (Subt))
10664 and then
10665 Chars (Etype (Base_Type (Entity (Subt)))) =
10666 Type_Id));
10667 end if;
10668
10669 -- A reference to the current type may appear as the prefix of
10670 -- a 'Class attribute.
10671
10672 elsif Nkind (Subt) = N_Attribute_Reference
10673 and then Attribute_Name (Subt) = Name_Class
10674 then
10675 return Names_T (Prefix (Subt));
10676
10677 else
10678 return False;
10679 end if;
10680 end Designates_T;
10681
10682 ----------------
10683 -- Mentions_T --
10684 ----------------
10685
10686 function Mentions_T (Acc_Def : Node_Id) return Boolean is
10687 Param_Spec : Node_Id;
10688
10689 Acc_Subprg : constant Node_Id :=
10690 Access_To_Subprogram_Definition (Acc_Def);
10691
10692 begin
10693 if No (Acc_Subprg) then
10694 return Designates_T (Subtype_Mark (Acc_Def));
10695 end if;
10696
10697 -- Component is an access_to_subprogram: examine its formals,
10698 -- and result definition in the case of an access_to_function.
10699
10700 Param_Spec := First (Parameter_Specifications (Acc_Subprg));
10701 while Present (Param_Spec) loop
10702 if Nkind (Parameter_Type (Param_Spec)) = N_Access_Definition
10703 and then Mentions_T (Parameter_Type (Param_Spec))
10704 then
10705 return True;
10706
10707 elsif Designates_T (Parameter_Type (Param_Spec)) then
10708 return True;
10709 end if;
10710
10711 Next (Param_Spec);
10712 end loop;
10713
10714 if Nkind (Acc_Subprg) = N_Access_Function_Definition then
10715 if Nkind (Result_Definition (Acc_Subprg)) =
10716 N_Access_Definition
10717 then
10718 return Mentions_T (Result_Definition (Acc_Subprg));
10719 else
10720 return Designates_T (Result_Definition (Acc_Subprg));
10721 end if;
10722 end if;
10723
10724 return False;
10725 end Mentions_T;
10726
10727 -- Start of processing for Check_Anonymous_Access_Components
10728
10729 begin
10730 if No (Comp_List) then
10731 return;
10732 end if;
10733
10734 Comp := First (Component_Items (Comp_List));
10735 while Present (Comp) loop
10736 if Nkind (Comp) = N_Component_Declaration
10737 and then Present
10738 (Access_Definition (Component_Definition (Comp)))
10739 and then
10740 Mentions_T (Access_Definition (Component_Definition (Comp)))
10741 then
10742 Comp_Def := Component_Definition (Comp);
10743 Acc_Def :=
10744 Access_To_Subprogram_Definition (Access_Definition (Comp_Def));
10745
10746 Build_Incomplete_Type_Declaration;
10747 Anon_Access := Make_Temporary (Loc, 'S');
10748
10749 -- Create a declaration for the anonymous access type: either
10750 -- an access_to_object or an access_to_subprogram.
10751
10752 if Present (Acc_Def) then
10753 if Nkind (Acc_Def) = N_Access_Function_Definition then
10754 Type_Def :=
10755 Make_Access_Function_Definition (Loc,
10756 Parameter_Specifications =>
10757 Parameter_Specifications (Acc_Def),
10758 Result_Definition => Result_Definition (Acc_Def));
10759 else
10760 Type_Def :=
10761 Make_Access_Procedure_Definition (Loc,
10762 Parameter_Specifications =>
10763 Parameter_Specifications (Acc_Def));
10764 end if;
10765
10766 else
10767 Type_Def :=
10768 Make_Access_To_Object_Definition (Loc,
10769 Subtype_Indication =>
10770 Relocate_Node
10771 (Subtype_Mark (Access_Definition (Comp_Def))));
10772
10773 Set_Constant_Present
10774 (Type_Def, Constant_Present (Access_Definition (Comp_Def)));
10775 Set_All_Present
10776 (Type_Def, All_Present (Access_Definition (Comp_Def)));
10777 end if;
10778
10779 Set_Null_Exclusion_Present
10780 (Type_Def,
10781 Null_Exclusion_Present (Access_Definition (Comp_Def)));
10782
10783 Decl :=
10784 Make_Full_Type_Declaration (Loc,
10785 Defining_Identifier => Anon_Access,
10786 Type_Definition => Type_Def);
10787
10788 Insert_Before (Typ_Decl, Decl);
10789 Analyze (Decl);
10790
10791 -- If an access to subprogram, create the extra formals
10792
10793 if Present (Acc_Def) then
10794 Create_Extra_Formals (Designated_Type (Anon_Access));
10795
10796 -- If an access to object, preserve entity of designated type,
10797 -- for ASIS use, before rewriting the component definition.
10798
10799 else
10800 declare
10801 Desig : Entity_Id;
10802
10803 begin
10804 Desig := Entity (Subtype_Indication (Type_Def));
10805
10806 -- If the access definition is to the current record,
10807 -- the visible entity at this point is an incomplete
10808 -- type. Retrieve the full view to simplify ASIS queries
10809
10810 if Ekind (Desig) = E_Incomplete_Type then
10811 Desig := Full_View (Desig);
10812 end if;
10813
10814 Set_Entity
10815 (Subtype_Mark (Access_Definition (Comp_Def)), Desig);
10816 end;
10817 end if;
10818
10819 Rewrite (Comp_Def,
10820 Make_Component_Definition (Loc,
10821 Subtype_Indication =>
10822 New_Occurrence_Of (Anon_Access, Loc)));
10823
10824 if Ekind (Designated_Type (Anon_Access)) = E_Subprogram_Type then
10825 Set_Ekind (Anon_Access, E_Anonymous_Access_Subprogram_Type);
10826 else
10827 Set_Ekind (Anon_Access, E_Anonymous_Access_Type);
10828 end if;
10829
10830 Set_Is_Local_Anonymous_Access (Anon_Access);
10831 end if;
10832
10833 Next (Comp);
10834 end loop;
10835
10836 if Present (Variant_Part (Comp_List)) then
10837 declare
10838 V : Node_Id;
10839 begin
10840 V := First_Non_Pragma (Variants (Variant_Part (Comp_List)));
10841 while Present (V) loop
10842 Check_Anonymous_Access_Components
10843 (Typ_Decl, Typ, Prev, Component_List (V));
10844 Next_Non_Pragma (V);
10845 end loop;
10846 end;
10847 end if;
10848 end Check_Anonymous_Access_Components;
10849
10850 ----------------------
10851 -- Check_Completion --
10852 ----------------------
10853
10854 procedure Check_Completion (Body_Id : Node_Id := Empty) is
10855 E : Entity_Id;
10856
10857 procedure Post_Error;
10858 -- Post error message for lack of completion for entity E
10859
10860 ----------------
10861 -- Post_Error --
10862 ----------------
10863
10864 procedure Post_Error is
10865 procedure Missing_Body;
10866 -- Output missing body message
10867
10868 ------------------
10869 -- Missing_Body --
10870 ------------------
10871
10872 procedure Missing_Body is
10873 begin
10874 -- Spec is in same unit, so we can post on spec
10875
10876 if In_Same_Source_Unit (Body_Id, E) then
10877 Error_Msg_N ("missing body for &", E);
10878
10879 -- Spec is in a separate unit, so we have to post on the body
10880
10881 else
10882 Error_Msg_NE ("missing body for & declared#!", Body_Id, E);
10883 end if;
10884 end Missing_Body;
10885
10886 -- Start of processing for Post_Error
10887
10888 begin
10889 if not Comes_From_Source (E) then
10890 if Ekind_In (E, E_Task_Type, E_Protected_Type) then
10891
10892 -- It may be an anonymous protected type created for a
10893 -- single variable. Post error on variable, if present.
10894
10895 declare
10896 Var : Entity_Id;
10897
10898 begin
10899 Var := First_Entity (Current_Scope);
10900 while Present (Var) loop
10901 exit when Etype (Var) = E
10902 and then Comes_From_Source (Var);
10903
10904 Next_Entity (Var);
10905 end loop;
10906
10907 if Present (Var) then
10908 E := Var;
10909 end if;
10910 end;
10911 end if;
10912 end if;
10913
10914 -- If a generated entity has no completion, then either previous
10915 -- semantic errors have disabled the expansion phase, or else we had
10916 -- missing subunits, or else we are compiling without expansion,
10917 -- or else something is very wrong.
10918
10919 if not Comes_From_Source (E) then
10920 pragma Assert
10921 (Serious_Errors_Detected > 0
10922 or else Configurable_Run_Time_Violations > 0
10923 or else Subunits_Missing
10924 or else not Expander_Active);
10925 return;
10926
10927 -- Here for source entity
10928
10929 else
10930 -- Here if no body to post the error message, so we post the error
10931 -- on the declaration that has no completion. This is not really
10932 -- the right place to post it, think about this later ???
10933
10934 if No (Body_Id) then
10935 if Is_Type (E) then
10936 Error_Msg_NE
10937 ("missing full declaration for }", Parent (E), E);
10938 else
10939 Error_Msg_NE ("missing body for &", Parent (E), E);
10940 end if;
10941
10942 -- Package body has no completion for a declaration that appears
10943 -- in the corresponding spec. Post error on the body, with a
10944 -- reference to the non-completed declaration.
10945
10946 else
10947 Error_Msg_Sloc := Sloc (E);
10948
10949 if Is_Type (E) then
10950 Error_Msg_NE ("missing full declaration for }!", Body_Id, E);
10951
10952 elsif Is_Overloadable (E)
10953 and then Current_Entity_In_Scope (E) /= E
10954 then
10955 -- It may be that the completion is mistyped and appears as
10956 -- a distinct overloading of the entity.
10957
10958 declare
10959 Candidate : constant Entity_Id :=
10960 Current_Entity_In_Scope (E);
10961 Decl : constant Node_Id :=
10962 Unit_Declaration_Node (Candidate);
10963
10964 begin
10965 if Is_Overloadable (Candidate)
10966 and then Ekind (Candidate) = Ekind (E)
10967 and then Nkind (Decl) = N_Subprogram_Body
10968 and then Acts_As_Spec (Decl)
10969 then
10970 Check_Type_Conformant (Candidate, E);
10971
10972 else
10973 Missing_Body;
10974 end if;
10975 end;
10976
10977 else
10978 Missing_Body;
10979 end if;
10980 end if;
10981 end if;
10982 end Post_Error;
10983
10984 -- Local variables
10985
10986 Pack_Id : constant Entity_Id := Current_Scope;
10987
10988 -- Start of processing for Check_Completion
10989
10990 begin
10991 E := First_Entity (Pack_Id);
10992 while Present (E) loop
10993 if Is_Intrinsic_Subprogram (E) then
10994 null;
10995
10996 -- The following situation requires special handling: a child unit
10997 -- that appears in the context clause of the body of its parent:
10998
10999 -- procedure Parent.Child (...);
11000
11001 -- with Parent.Child;
11002 -- package body Parent is
11003
11004 -- Here Parent.Child appears as a local entity, but should not be
11005 -- flagged as requiring completion, because it is a compilation
11006 -- unit.
11007
11008 -- Ignore missing completion for a subprogram that does not come from
11009 -- source (including the _Call primitive operation of RAS types,
11010 -- which has to have the flag Comes_From_Source for other purposes):
11011 -- we assume that the expander will provide the missing completion.
11012 -- In case of previous errors, other expansion actions that provide
11013 -- bodies for null procedures with not be invoked, so inhibit message
11014 -- in those cases.
11015
11016 -- Note that E_Operator is not in the list that follows, because
11017 -- this kind is reserved for predefined operators, that are
11018 -- intrinsic and do not need completion.
11019
11020 elsif Ekind_In (E, E_Function,
11021 E_Procedure,
11022 E_Generic_Function,
11023 E_Generic_Procedure)
11024 then
11025 if Has_Completion (E) then
11026 null;
11027
11028 elsif Is_Subprogram (E) and then Is_Abstract_Subprogram (E) then
11029 null;
11030
11031 elsif Is_Subprogram (E)
11032 and then (not Comes_From_Source (E)
11033 or else Chars (E) = Name_uCall)
11034 then
11035 null;
11036
11037 elsif
11038 Nkind (Parent (Unit_Declaration_Node (E))) = N_Compilation_Unit
11039 then
11040 null;
11041
11042 elsif Nkind (Parent (E)) = N_Procedure_Specification
11043 and then Null_Present (Parent (E))
11044 and then Serious_Errors_Detected > 0
11045 then
11046 null;
11047
11048 else
11049 Post_Error;
11050 end if;
11051
11052 elsif Is_Entry (E) then
11053 if not Has_Completion (E) and then
11054 (Ekind (Scope (E)) = E_Protected_Object
11055 or else Ekind (Scope (E)) = E_Protected_Type)
11056 then
11057 Post_Error;
11058 end if;
11059
11060 elsif Is_Package_Or_Generic_Package (E) then
11061 if Unit_Requires_Body (E) then
11062 if not Has_Completion (E)
11063 and then Nkind (Parent (Unit_Declaration_Node (E))) /=
11064 N_Compilation_Unit
11065 then
11066 Post_Error;
11067 end if;
11068
11069 elsif not Is_Child_Unit (E) then
11070 May_Need_Implicit_Body (E);
11071 end if;
11072
11073 -- A formal incomplete type (Ada 2012) does not require a completion;
11074 -- other incomplete type declarations do.
11075
11076 elsif Ekind (E) = E_Incomplete_Type
11077 and then No (Underlying_Type (E))
11078 and then not Is_Generic_Type (E)
11079 then
11080 Post_Error;
11081
11082 elsif Ekind_In (E, E_Task_Type, E_Protected_Type)
11083 and then not Has_Completion (E)
11084 then
11085 Post_Error;
11086
11087 -- A single task declared in the current scope is a constant, verify
11088 -- that the body of its anonymous type is in the same scope. If the
11089 -- task is defined elsewhere, this may be a renaming declaration for
11090 -- which no completion is needed.
11091
11092 elsif Ekind (E) = E_Constant
11093 and then Ekind (Etype (E)) = E_Task_Type
11094 and then not Has_Completion (Etype (E))
11095 and then Scope (Etype (E)) = Current_Scope
11096 then
11097 Post_Error;
11098
11099 elsif Ekind (E) = E_Protected_Object
11100 and then not Has_Completion (Etype (E))
11101 then
11102 Post_Error;
11103
11104 elsif Ekind (E) = E_Record_Type then
11105 if Is_Tagged_Type (E) then
11106 Check_Abstract_Overriding (E);
11107 Check_Conventions (E);
11108 end if;
11109
11110 Check_Aliased_Component_Types (E);
11111
11112 elsif Ekind (E) = E_Array_Type then
11113 Check_Aliased_Component_Types (E);
11114
11115 end if;
11116
11117 Next_Entity (E);
11118 end loop;
11119 end Check_Completion;
11120
11121 ------------------------------------
11122 -- Check_CPP_Type_Has_No_Defaults --
11123 ------------------------------------
11124
11125 procedure Check_CPP_Type_Has_No_Defaults (T : Entity_Id) is
11126 Tdef : constant Node_Id := Type_Definition (Declaration_Node (T));
11127 Clist : Node_Id;
11128 Comp : Node_Id;
11129
11130 begin
11131 -- Obtain the component list
11132
11133 if Nkind (Tdef) = N_Record_Definition then
11134 Clist := Component_List (Tdef);
11135 else pragma Assert (Nkind (Tdef) = N_Derived_Type_Definition);
11136 Clist := Component_List (Record_Extension_Part (Tdef));
11137 end if;
11138
11139 -- Check all components to ensure no default expressions
11140
11141 if Present (Clist) then
11142 Comp := First (Component_Items (Clist));
11143 while Present (Comp) loop
11144 if Present (Expression (Comp)) then
11145 Error_Msg_N
11146 ("component of imported 'C'P'P type cannot have "
11147 & "default expression", Expression (Comp));
11148 end if;
11149
11150 Next (Comp);
11151 end loop;
11152 end if;
11153 end Check_CPP_Type_Has_No_Defaults;
11154
11155 ----------------------------
11156 -- Check_Delta_Expression --
11157 ----------------------------
11158
11159 procedure Check_Delta_Expression (E : Node_Id) is
11160 begin
11161 if not (Is_Real_Type (Etype (E))) then
11162 Wrong_Type (E, Any_Real);
11163
11164 elsif not Is_OK_Static_Expression (E) then
11165 Flag_Non_Static_Expr
11166 ("non-static expression used for delta value!", E);
11167
11168 elsif not UR_Is_Positive (Expr_Value_R (E)) then
11169 Error_Msg_N ("delta expression must be positive", E);
11170
11171 else
11172 return;
11173 end if;
11174
11175 -- If any of above errors occurred, then replace the incorrect
11176 -- expression by the real 0.1, which should prevent further errors.
11177
11178 Rewrite (E,
11179 Make_Real_Literal (Sloc (E), Ureal_Tenth));
11180 Analyze_And_Resolve (E, Standard_Float);
11181 end Check_Delta_Expression;
11182
11183 -----------------------------
11184 -- Check_Digits_Expression --
11185 -----------------------------
11186
11187 procedure Check_Digits_Expression (E : Node_Id) is
11188 begin
11189 if not (Is_Integer_Type (Etype (E))) then
11190 Wrong_Type (E, Any_Integer);
11191
11192 elsif not Is_OK_Static_Expression (E) then
11193 Flag_Non_Static_Expr
11194 ("non-static expression used for digits value!", E);
11195
11196 elsif Expr_Value (E) <= 0 then
11197 Error_Msg_N ("digits value must be greater than zero", E);
11198
11199 else
11200 return;
11201 end if;
11202
11203 -- If any of above errors occurred, then replace the incorrect
11204 -- expression by the integer 1, which should prevent further errors.
11205
11206 Rewrite (E, Make_Integer_Literal (Sloc (E), 1));
11207 Analyze_And_Resolve (E, Standard_Integer);
11208
11209 end Check_Digits_Expression;
11210
11211 --------------------------
11212 -- Check_Initialization --
11213 --------------------------
11214
11215 procedure Check_Initialization (T : Entity_Id; Exp : Node_Id) is
11216 begin
11217 -- Special processing for limited types
11218
11219 if Is_Limited_Type (T)
11220 and then not In_Instance
11221 and then not In_Inlined_Body
11222 then
11223 if not OK_For_Limited_Init (T, Exp) then
11224
11225 -- In GNAT mode, this is just a warning, to allow it to be evilly
11226 -- turned off. Otherwise it is a real error.
11227
11228 if GNAT_Mode then
11229 Error_Msg_N
11230 ("??cannot initialize entities of limited type!", Exp);
11231
11232 elsif Ada_Version < Ada_2005 then
11233
11234 -- The side effect removal machinery may generate illegal Ada
11235 -- code to avoid the usage of access types and 'reference in
11236 -- SPARK mode. Since this is legal code with respect to theorem
11237 -- proving, do not emit the error.
11238
11239 if GNATprove_Mode
11240 and then Nkind (Exp) = N_Function_Call
11241 and then Nkind (Parent (Exp)) = N_Object_Declaration
11242 and then not Comes_From_Source
11243 (Defining_Identifier (Parent (Exp)))
11244 then
11245 null;
11246
11247 else
11248 Error_Msg_N
11249 ("cannot initialize entities of limited type", Exp);
11250 Explain_Limited_Type (T, Exp);
11251 end if;
11252
11253 else
11254 -- Specialize error message according to kind of illegal
11255 -- initial expression.
11256
11257 if Nkind (Exp) = N_Type_Conversion
11258 and then Nkind (Expression (Exp)) = N_Function_Call
11259 then
11260 Error_Msg_N
11261 ("illegal context for call"
11262 & " to function with limited result", Exp);
11263
11264 else
11265 Error_Msg_N
11266 ("initialization of limited object requires aggregate "
11267 & "or function call", Exp);
11268 end if;
11269 end if;
11270 end if;
11271 end if;
11272
11273 -- In gnatc or gnatprove mode, make sure set Do_Range_Check flag gets
11274 -- set unless we can be sure that no range check is required.
11275
11276 if (GNATprove_Mode or not Expander_Active)
11277 and then Is_Scalar_Type (T)
11278 and then not Is_In_Range (Exp, T, Assume_Valid => True)
11279 then
11280 Set_Do_Range_Check (Exp);
11281 end if;
11282 end Check_Initialization;
11283
11284 ----------------------
11285 -- Check_Interfaces --
11286 ----------------------
11287
11288 procedure Check_Interfaces (N : Node_Id; Def : Node_Id) is
11289 Parent_Type : constant Entity_Id := Etype (Defining_Identifier (N));
11290
11291 Iface : Node_Id;
11292 Iface_Def : Node_Id;
11293 Iface_Typ : Entity_Id;
11294 Parent_Node : Node_Id;
11295
11296 Is_Task : Boolean := False;
11297 -- Set True if parent type or any progenitor is a task interface
11298
11299 Is_Protected : Boolean := False;
11300 -- Set True if parent type or any progenitor is a protected interface
11301
11302 procedure Check_Ifaces (Iface_Def : Node_Id; Error_Node : Node_Id);
11303 -- Check that a progenitor is compatible with declaration. If an error
11304 -- message is output, it is posted on Error_Node.
11305
11306 ------------------
11307 -- Check_Ifaces --
11308 ------------------
11309
11310 procedure Check_Ifaces (Iface_Def : Node_Id; Error_Node : Node_Id) is
11311 Iface_Id : constant Entity_Id :=
11312 Defining_Identifier (Parent (Iface_Def));
11313 Type_Def : Node_Id;
11314
11315 begin
11316 if Nkind (N) = N_Private_Extension_Declaration then
11317 Type_Def := N;
11318 else
11319 Type_Def := Type_Definition (N);
11320 end if;
11321
11322 if Is_Task_Interface (Iface_Id) then
11323 Is_Task := True;
11324
11325 elsif Is_Protected_Interface (Iface_Id) then
11326 Is_Protected := True;
11327 end if;
11328
11329 if Is_Synchronized_Interface (Iface_Id) then
11330
11331 -- A consequence of 3.9.4 (6/2) and 7.3 (7.2/2) is that a private
11332 -- extension derived from a synchronized interface must explicitly
11333 -- be declared synchronized, because the full view will be a
11334 -- synchronized type.
11335
11336 if Nkind (N) = N_Private_Extension_Declaration then
11337 if not Synchronized_Present (N) then
11338 Error_Msg_NE
11339 ("private extension of& must be explicitly synchronized",
11340 N, Iface_Id);
11341 end if;
11342
11343 -- However, by 3.9.4(16/2), a full type that is a record extension
11344 -- is never allowed to derive from a synchronized interface (note
11345 -- that interfaces must be excluded from this check, because those
11346 -- are represented by derived type definitions in some cases).
11347
11348 elsif Nkind (Type_Definition (N)) = N_Derived_Type_Definition
11349 and then not Interface_Present (Type_Definition (N))
11350 then
11351 Error_Msg_N ("record extension cannot derive from synchronized "
11352 & "interface", Error_Node);
11353 end if;
11354 end if;
11355
11356 -- Check that the characteristics of the progenitor are compatible
11357 -- with the explicit qualifier in the declaration.
11358 -- The check only applies to qualifiers that come from source.
11359 -- Limited_Present also appears in the declaration of corresponding
11360 -- records, and the check does not apply to them.
11361
11362 if Limited_Present (Type_Def)
11363 and then not
11364 Is_Concurrent_Record_Type (Defining_Identifier (N))
11365 then
11366 if Is_Limited_Interface (Parent_Type)
11367 and then not Is_Limited_Interface (Iface_Id)
11368 then
11369 Error_Msg_NE
11370 ("progenitor & must be limited interface",
11371 Error_Node, Iface_Id);
11372
11373 elsif
11374 (Task_Present (Iface_Def)
11375 or else Protected_Present (Iface_Def)
11376 or else Synchronized_Present (Iface_Def))
11377 and then Nkind (N) /= N_Private_Extension_Declaration
11378 and then not Error_Posted (N)
11379 then
11380 Error_Msg_NE
11381 ("progenitor & must be limited interface",
11382 Error_Node, Iface_Id);
11383 end if;
11384
11385 -- Protected interfaces can only inherit from limited, synchronized
11386 -- or protected interfaces.
11387
11388 elsif Nkind (N) = N_Full_Type_Declaration
11389 and then Protected_Present (Type_Def)
11390 then
11391 if Limited_Present (Iface_Def)
11392 or else Synchronized_Present (Iface_Def)
11393 or else Protected_Present (Iface_Def)
11394 then
11395 null;
11396
11397 elsif Task_Present (Iface_Def) then
11398 Error_Msg_N ("(Ada 2005) protected interface cannot inherit "
11399 & "from task interface", Error_Node);
11400
11401 else
11402 Error_Msg_N ("(Ada 2005) protected interface cannot inherit "
11403 & "from non-limited interface", Error_Node);
11404 end if;
11405
11406 -- Ada 2005 (AI-345): Synchronized interfaces can only inherit from
11407 -- limited and synchronized.
11408
11409 elsif Synchronized_Present (Type_Def) then
11410 if Limited_Present (Iface_Def)
11411 or else Synchronized_Present (Iface_Def)
11412 then
11413 null;
11414
11415 elsif Protected_Present (Iface_Def)
11416 and then Nkind (N) /= N_Private_Extension_Declaration
11417 then
11418 Error_Msg_N ("(Ada 2005) synchronized interface cannot inherit "
11419 & "from protected interface", Error_Node);
11420
11421 elsif Task_Present (Iface_Def)
11422 and then Nkind (N) /= N_Private_Extension_Declaration
11423 then
11424 Error_Msg_N ("(Ada 2005) synchronized interface cannot inherit "
11425 & "from task interface", Error_Node);
11426
11427 elsif not Is_Limited_Interface (Iface_Id) then
11428 Error_Msg_N ("(Ada 2005) synchronized interface cannot inherit "
11429 & "from non-limited interface", Error_Node);
11430 end if;
11431
11432 -- Ada 2005 (AI-345): Task interfaces can only inherit from limited,
11433 -- synchronized or task interfaces.
11434
11435 elsif Nkind (N) = N_Full_Type_Declaration
11436 and then Task_Present (Type_Def)
11437 then
11438 if Limited_Present (Iface_Def)
11439 or else Synchronized_Present (Iface_Def)
11440 or else Task_Present (Iface_Def)
11441 then
11442 null;
11443
11444 elsif Protected_Present (Iface_Def) then
11445 Error_Msg_N ("(Ada 2005) task interface cannot inherit from "
11446 & "protected interface", Error_Node);
11447
11448 else
11449 Error_Msg_N ("(Ada 2005) task interface cannot inherit from "
11450 & "non-limited interface", Error_Node);
11451 end if;
11452 end if;
11453 end Check_Ifaces;
11454
11455 -- Start of processing for Check_Interfaces
11456
11457 begin
11458 if Is_Interface (Parent_Type) then
11459 if Is_Task_Interface (Parent_Type) then
11460 Is_Task := True;
11461
11462 elsif Is_Protected_Interface (Parent_Type) then
11463 Is_Protected := True;
11464 end if;
11465 end if;
11466
11467 if Nkind (N) = N_Private_Extension_Declaration then
11468
11469 -- Check that progenitors are compatible with declaration
11470
11471 Iface := First (Interface_List (Def));
11472 while Present (Iface) loop
11473 Iface_Typ := Find_Type_Of_Subtype_Indic (Iface);
11474
11475 Parent_Node := Parent (Base_Type (Iface_Typ));
11476 Iface_Def := Type_Definition (Parent_Node);
11477
11478 if not Is_Interface (Iface_Typ) then
11479 Diagnose_Interface (Iface, Iface_Typ);
11480 else
11481 Check_Ifaces (Iface_Def, Iface);
11482 end if;
11483
11484 Next (Iface);
11485 end loop;
11486
11487 if Is_Task and Is_Protected then
11488 Error_Msg_N
11489 ("type cannot derive from task and protected interface", N);
11490 end if;
11491
11492 return;
11493 end if;
11494
11495 -- Full type declaration of derived type.
11496 -- Check compatibility with parent if it is interface type
11497
11498 if Nkind (Type_Definition (N)) = N_Derived_Type_Definition
11499 and then Is_Interface (Parent_Type)
11500 then
11501 Parent_Node := Parent (Parent_Type);
11502
11503 -- More detailed checks for interface varieties
11504
11505 Check_Ifaces
11506 (Iface_Def => Type_Definition (Parent_Node),
11507 Error_Node => Subtype_Indication (Type_Definition (N)));
11508 end if;
11509
11510 Iface := First (Interface_List (Def));
11511 while Present (Iface) loop
11512 Iface_Typ := Find_Type_Of_Subtype_Indic (Iface);
11513
11514 Parent_Node := Parent (Base_Type (Iface_Typ));
11515 Iface_Def := Type_Definition (Parent_Node);
11516
11517 if not Is_Interface (Iface_Typ) then
11518 Diagnose_Interface (Iface, Iface_Typ);
11519
11520 else
11521 -- "The declaration of a specific descendant of an interface
11522 -- type freezes the interface type" RM 13.14
11523
11524 Freeze_Before (N, Iface_Typ);
11525 Check_Ifaces (Iface_Def, Error_Node => Iface);
11526 end if;
11527
11528 Next (Iface);
11529 end loop;
11530
11531 if Is_Task and Is_Protected then
11532 Error_Msg_N
11533 ("type cannot derive from task and protected interface", N);
11534 end if;
11535 end Check_Interfaces;
11536
11537 ------------------------------------
11538 -- Check_Or_Process_Discriminants --
11539 ------------------------------------
11540
11541 -- If an incomplete or private type declaration was already given for the
11542 -- type, the discriminants may have already been processed if they were
11543 -- present on the incomplete declaration. In this case a full conformance
11544 -- check has been performed in Find_Type_Name, and we then recheck here
11545 -- some properties that can't be checked on the partial view alone.
11546 -- Otherwise we call Process_Discriminants.
11547
11548 procedure Check_Or_Process_Discriminants
11549 (N : Node_Id;
11550 T : Entity_Id;
11551 Prev : Entity_Id := Empty)
11552 is
11553 begin
11554 if Has_Discriminants (T) then
11555
11556 -- Discriminants are already set on T if they were already present
11557 -- on the partial view. Make them visible to component declarations.
11558
11559 declare
11560 D : Entity_Id;
11561 -- Discriminant on T (full view) referencing expr on partial view
11562
11563 Prev_D : Entity_Id;
11564 -- Entity of corresponding discriminant on partial view
11565
11566 New_D : Node_Id;
11567 -- Discriminant specification for full view, expression is
11568 -- the syntactic copy on full view (which has been checked for
11569 -- conformance with partial view), only used here to post error
11570 -- message.
11571
11572 begin
11573 D := First_Discriminant (T);
11574 New_D := First (Discriminant_Specifications (N));
11575 while Present (D) loop
11576 Prev_D := Current_Entity (D);
11577 Set_Current_Entity (D);
11578 Set_Is_Immediately_Visible (D);
11579 Set_Homonym (D, Prev_D);
11580
11581 -- Handle the case where there is an untagged partial view and
11582 -- the full view is tagged: must disallow discriminants with
11583 -- defaults, unless compiling for Ada 2012, which allows a
11584 -- limited tagged type to have defaulted discriminants (see
11585 -- AI05-0214). However, suppress error here if it was already
11586 -- reported on the default expression of the partial view.
11587
11588 if Is_Tagged_Type (T)
11589 and then Present (Expression (Parent (D)))
11590 and then (not Is_Limited_Type (Current_Scope)
11591 or else Ada_Version < Ada_2012)
11592 and then not Error_Posted (Expression (Parent (D)))
11593 then
11594 if Ada_Version >= Ada_2012 then
11595 Error_Msg_N
11596 ("discriminants of nonlimited tagged type cannot have "
11597 & "defaults",
11598 Expression (New_D));
11599 else
11600 Error_Msg_N
11601 ("discriminants of tagged type cannot have defaults",
11602 Expression (New_D));
11603 end if;
11604 end if;
11605
11606 -- Ada 2005 (AI-230): Access discriminant allowed in
11607 -- non-limited record types.
11608
11609 if Ada_Version < Ada_2005 then
11610
11611 -- This restriction gets applied to the full type here. It
11612 -- has already been applied earlier to the partial view.
11613
11614 Check_Access_Discriminant_Requires_Limited (Parent (D), N);
11615 end if;
11616
11617 Next_Discriminant (D);
11618 Next (New_D);
11619 end loop;
11620 end;
11621
11622 elsif Present (Discriminant_Specifications (N)) then
11623 Process_Discriminants (N, Prev);
11624 end if;
11625 end Check_Or_Process_Discriminants;
11626
11627 ----------------------
11628 -- Check_Real_Bound --
11629 ----------------------
11630
11631 procedure Check_Real_Bound (Bound : Node_Id) is
11632 begin
11633 if not Is_Real_Type (Etype (Bound)) then
11634 Error_Msg_N
11635 ("bound in real type definition must be of real type", Bound);
11636
11637 elsif not Is_OK_Static_Expression (Bound) then
11638 Flag_Non_Static_Expr
11639 ("non-static expression used for real type bound!", Bound);
11640
11641 else
11642 return;
11643 end if;
11644
11645 Rewrite
11646 (Bound, Make_Real_Literal (Sloc (Bound), Ureal_0));
11647 Analyze (Bound);
11648 Resolve (Bound, Standard_Float);
11649 end Check_Real_Bound;
11650
11651 ------------------------------
11652 -- Complete_Private_Subtype --
11653 ------------------------------
11654
11655 procedure Complete_Private_Subtype
11656 (Priv : Entity_Id;
11657 Full : Entity_Id;
11658 Full_Base : Entity_Id;
11659 Related_Nod : Node_Id)
11660 is
11661 Save_Next_Entity : Entity_Id;
11662 Save_Homonym : Entity_Id;
11663
11664 begin
11665 -- Set semantic attributes for (implicit) private subtype completion.
11666 -- If the full type has no discriminants, then it is a copy of the
11667 -- full view of the base. Otherwise, it is a subtype of the base with
11668 -- a possible discriminant constraint. Save and restore the original
11669 -- Next_Entity field of full to ensure that the calls to Copy_Node do
11670 -- not corrupt the entity chain.
11671
11672 -- Note that the type of the full view is the same entity as the type
11673 -- of the partial view. In this fashion, the subtype has access to the
11674 -- correct view of the parent.
11675
11676 Save_Next_Entity := Next_Entity (Full);
11677 Save_Homonym := Homonym (Priv);
11678
11679 case Ekind (Full_Base) is
11680 when E_Record_Type |
11681 E_Record_Subtype |
11682 Class_Wide_Kind |
11683 Private_Kind |
11684 Task_Kind |
11685 Protected_Kind =>
11686 Copy_Node (Priv, Full);
11687
11688 Set_Has_Discriminants
11689 (Full, Has_Discriminants (Full_Base));
11690 Set_Has_Unknown_Discriminants
11691 (Full, Has_Unknown_Discriminants (Full_Base));
11692 Set_First_Entity (Full, First_Entity (Full_Base));
11693 Set_Last_Entity (Full, Last_Entity (Full_Base));
11694
11695 -- If the underlying base type is constrained, we know that the
11696 -- full view of the subtype is constrained as well (the converse
11697 -- is not necessarily true).
11698
11699 if Is_Constrained (Full_Base) then
11700 Set_Is_Constrained (Full);
11701 end if;
11702
11703 when others =>
11704 Copy_Node (Full_Base, Full);
11705
11706 Set_Chars (Full, Chars (Priv));
11707 Conditional_Delay (Full, Priv);
11708 Set_Sloc (Full, Sloc (Priv));
11709 end case;
11710
11711 Set_Next_Entity (Full, Save_Next_Entity);
11712 Set_Homonym (Full, Save_Homonym);
11713 Set_Associated_Node_For_Itype (Full, Related_Nod);
11714
11715 -- Set common attributes for all subtypes: kind, convention, etc.
11716
11717 Set_Ekind (Full, Subtype_Kind (Ekind (Full_Base)));
11718 Set_Convention (Full, Convention (Full_Base));
11719
11720 -- The Etype of the full view is inconsistent. Gigi needs to see the
11721 -- structural full view, which is what the current scheme gives: the
11722 -- Etype of the full view is the etype of the full base. However, if the
11723 -- full base is a derived type, the full view then looks like a subtype
11724 -- of the parent, not a subtype of the full base. If instead we write:
11725
11726 -- Set_Etype (Full, Full_Base);
11727
11728 -- then we get inconsistencies in the front-end (confusion between
11729 -- views). Several outstanding bugs are related to this ???
11730
11731 Set_Is_First_Subtype (Full, False);
11732 Set_Scope (Full, Scope (Priv));
11733 Set_Size_Info (Full, Full_Base);
11734 Set_RM_Size (Full, RM_Size (Full_Base));
11735 Set_Is_Itype (Full);
11736
11737 -- A subtype of a private-type-without-discriminants, whose full-view
11738 -- has discriminants with default expressions, is not constrained.
11739
11740 if not Has_Discriminants (Priv) then
11741 Set_Is_Constrained (Full, Is_Constrained (Full_Base));
11742
11743 if Has_Discriminants (Full_Base) then
11744 Set_Discriminant_Constraint
11745 (Full, Discriminant_Constraint (Full_Base));
11746
11747 -- The partial view may have been indefinite, the full view
11748 -- might not be.
11749
11750 Set_Has_Unknown_Discriminants
11751 (Full, Has_Unknown_Discriminants (Full_Base));
11752 end if;
11753 end if;
11754
11755 Set_First_Rep_Item (Full, First_Rep_Item (Full_Base));
11756 Set_Depends_On_Private (Full, Has_Private_Component (Full));
11757
11758 -- Freeze the private subtype entity if its parent is delayed, and not
11759 -- already frozen. We skip this processing if the type is an anonymous
11760 -- subtype of a record component, or is the corresponding record of a
11761 -- protected type, since these are processed when the enclosing type
11762 -- is frozen.
11763
11764 if not Is_Type (Scope (Full)) then
11765 Set_Has_Delayed_Freeze (Full,
11766 Has_Delayed_Freeze (Full_Base)
11767 and then (not Is_Frozen (Full_Base)));
11768 end if;
11769
11770 Set_Freeze_Node (Full, Empty);
11771 Set_Is_Frozen (Full, False);
11772 Set_Full_View (Priv, Full);
11773
11774 if Has_Discriminants (Full) then
11775 Set_Stored_Constraint_From_Discriminant_Constraint (Full);
11776 Set_Stored_Constraint (Priv, Stored_Constraint (Full));
11777
11778 if Has_Unknown_Discriminants (Full) then
11779 Set_Discriminant_Constraint (Full, No_Elist);
11780 end if;
11781 end if;
11782
11783 if Ekind (Full_Base) = E_Record_Type
11784 and then Has_Discriminants (Full_Base)
11785 and then Has_Discriminants (Priv) -- might not, if errors
11786 and then not Has_Unknown_Discriminants (Priv)
11787 and then not Is_Empty_Elmt_List (Discriminant_Constraint (Priv))
11788 then
11789 Create_Constrained_Components
11790 (Full, Related_Nod, Full_Base, Discriminant_Constraint (Priv));
11791
11792 -- If the full base is itself derived from private, build a congruent
11793 -- subtype of its underlying type, for use by the back end. For a
11794 -- constrained record component, the declaration cannot be placed on
11795 -- the component list, but it must nevertheless be built an analyzed, to
11796 -- supply enough information for Gigi to compute the size of component.
11797
11798 elsif Ekind (Full_Base) in Private_Kind
11799 and then Is_Derived_Type (Full_Base)
11800 and then Has_Discriminants (Full_Base)
11801 and then (Ekind (Current_Scope) /= E_Record_Subtype)
11802 then
11803 if not Is_Itype (Priv)
11804 and then
11805 Nkind (Subtype_Indication (Parent (Priv))) = N_Subtype_Indication
11806 then
11807 Build_Underlying_Full_View
11808 (Parent (Priv), Full, Etype (Full_Base));
11809
11810 elsif Nkind (Related_Nod) = N_Component_Declaration then
11811 Build_Underlying_Full_View (Related_Nod, Full, Etype (Full_Base));
11812 end if;
11813
11814 elsif Is_Record_Type (Full_Base) then
11815
11816 -- Show Full is simply a renaming of Full_Base
11817
11818 Set_Cloned_Subtype (Full, Full_Base);
11819 end if;
11820
11821 -- It is unsafe to share the bounds of a scalar type, because the Itype
11822 -- is elaborated on demand, and if a bound is non-static then different
11823 -- orders of elaboration in different units will lead to different
11824 -- external symbols.
11825
11826 if Is_Scalar_Type (Full_Base) then
11827 Set_Scalar_Range (Full,
11828 Make_Range (Sloc (Related_Nod),
11829 Low_Bound =>
11830 Duplicate_Subexpr_No_Checks (Type_Low_Bound (Full_Base)),
11831 High_Bound =>
11832 Duplicate_Subexpr_No_Checks (Type_High_Bound (Full_Base))));
11833
11834 -- This completion inherits the bounds of the full parent, but if
11835 -- the parent is an unconstrained floating point type, so is the
11836 -- completion.
11837
11838 if Is_Floating_Point_Type (Full_Base) then
11839 Set_Includes_Infinities
11840 (Scalar_Range (Full), Has_Infinities (Full_Base));
11841 end if;
11842 end if;
11843
11844 -- ??? It seems that a lot of fields are missing that should be copied
11845 -- from Full_Base to Full. Here are some that are introduced in a
11846 -- non-disruptive way but a cleanup is necessary.
11847
11848 if Is_Tagged_Type (Full_Base) then
11849 Set_Is_Tagged_Type (Full);
11850 Set_Direct_Primitive_Operations
11851 (Full, Direct_Primitive_Operations (Full_Base));
11852 Set_No_Tagged_Streams_Pragma
11853 (Full, No_Tagged_Streams_Pragma (Full_Base));
11854
11855 -- Inherit class_wide type of full_base in case the partial view was
11856 -- not tagged. Otherwise it has already been created when the private
11857 -- subtype was analyzed.
11858
11859 if No (Class_Wide_Type (Full)) then
11860 Set_Class_Wide_Type (Full, Class_Wide_Type (Full_Base));
11861 end if;
11862
11863 -- If this is a subtype of a protected or task type, constrain its
11864 -- corresponding record, unless this is a subtype without constraints,
11865 -- i.e. a simple renaming as with an actual subtype in an instance.
11866
11867 elsif Is_Concurrent_Type (Full_Base) then
11868 if Has_Discriminants (Full)
11869 and then Present (Corresponding_Record_Type (Full_Base))
11870 and then
11871 not Is_Empty_Elmt_List (Discriminant_Constraint (Full))
11872 then
11873 Set_Corresponding_Record_Type (Full,
11874 Constrain_Corresponding_Record
11875 (Full, Corresponding_Record_Type (Full_Base), Related_Nod));
11876
11877 else
11878 Set_Corresponding_Record_Type (Full,
11879 Corresponding_Record_Type (Full_Base));
11880 end if;
11881 end if;
11882
11883 -- Link rep item chain, and also setting of Has_Predicates from private
11884 -- subtype to full subtype, since we will need these on the full subtype
11885 -- to create the predicate function. Note that the full subtype may
11886 -- already have rep items, inherited from the full view of the base
11887 -- type, so we must be sure not to overwrite these entries.
11888
11889 declare
11890 Append : Boolean;
11891 Item : Node_Id;
11892 Next_Item : Node_Id;
11893
11894 begin
11895 Item := First_Rep_Item (Full);
11896
11897 -- If no existing rep items on full type, we can just link directly
11898 -- to the list of items on the private type, if any exist.. Same if
11899 -- the rep items are only those inherited from the base
11900
11901 if (No (Item)
11902 or else Nkind (Item) /= N_Aspect_Specification
11903 or else Entity (Item) = Full_Base)
11904 and then Present (First_Rep_Item (Priv))
11905 then
11906 Set_First_Rep_Item (Full, First_Rep_Item (Priv));
11907
11908 -- Otherwise, search to the end of items currently linked to the full
11909 -- subtype and append the private items to the end. However, if Priv
11910 -- and Full already have the same list of rep items, then the append
11911 -- is not done, as that would create a circularity.
11912
11913 elsif Item /= First_Rep_Item (Priv) then
11914 Append := True;
11915 loop
11916 Next_Item := Next_Rep_Item (Item);
11917 exit when No (Next_Item);
11918 Item := Next_Item;
11919
11920 -- If the private view has aspect specifications, the full view
11921 -- inherits them. Since these aspects may already have been
11922 -- attached to the full view during derivation, do not append
11923 -- them if already present.
11924
11925 if Item = First_Rep_Item (Priv) then
11926 Append := False;
11927 exit;
11928 end if;
11929 end loop;
11930
11931 -- And link the private type items at the end of the chain
11932
11933 if Append then
11934 Set_Next_Rep_Item (Item, First_Rep_Item (Priv));
11935 end if;
11936 end if;
11937 end;
11938
11939 -- Make sure Has_Predicates is set on full type if it is set on the
11940 -- private type. Note that it may already be set on the full type and
11941 -- if so, we don't want to unset it. Similarly, propagate information
11942 -- about delayed aspects, because the corresponding pragmas must be
11943 -- analyzed when one of the views is frozen. This last step is needed
11944 -- in particular when the full type is a scalar type for which an
11945 -- anonymous base type is constructed.
11946
11947 -- The predicate functions are generated either at the freeze point
11948 -- of the type or at the end of the visible part, and we must avoid
11949 -- generating them twice.
11950
11951 if Has_Predicates (Priv) then
11952 Set_Has_Predicates (Full);
11953
11954 if Present (Predicate_Function (Priv))
11955 and then No (Predicate_Function (Full))
11956 then
11957 Set_Predicate_Function (Full, Predicate_Function (Priv));
11958 end if;
11959 end if;
11960
11961 if Has_Delayed_Aspects (Priv) then
11962 Set_Has_Delayed_Aspects (Full);
11963 end if;
11964 end Complete_Private_Subtype;
11965
11966 ----------------------------
11967 -- Constant_Redeclaration --
11968 ----------------------------
11969
11970 procedure Constant_Redeclaration
11971 (Id : Entity_Id;
11972 N : Node_Id;
11973 T : out Entity_Id)
11974 is
11975 Prev : constant Entity_Id := Current_Entity_In_Scope (Id);
11976 Obj_Def : constant Node_Id := Object_Definition (N);
11977 New_T : Entity_Id;
11978
11979 procedure Check_Possible_Deferred_Completion
11980 (Prev_Id : Entity_Id;
11981 Prev_Obj_Def : Node_Id;
11982 Curr_Obj_Def : Node_Id);
11983 -- Determine whether the two object definitions describe the partial
11984 -- and the full view of a constrained deferred constant. Generate
11985 -- a subtype for the full view and verify that it statically matches
11986 -- the subtype of the partial view.
11987
11988 procedure Check_Recursive_Declaration (Typ : Entity_Id);
11989 -- If deferred constant is an access type initialized with an allocator,
11990 -- check whether there is an illegal recursion in the definition,
11991 -- through a default value of some record subcomponent. This is normally
11992 -- detected when generating init procs, but requires this additional
11993 -- mechanism when expansion is disabled.
11994
11995 ----------------------------------------
11996 -- Check_Possible_Deferred_Completion --
11997 ----------------------------------------
11998
11999 procedure Check_Possible_Deferred_Completion
12000 (Prev_Id : Entity_Id;
12001 Prev_Obj_Def : Node_Id;
12002 Curr_Obj_Def : Node_Id)
12003 is
12004 begin
12005 if Nkind (Prev_Obj_Def) = N_Subtype_Indication
12006 and then Present (Constraint (Prev_Obj_Def))
12007 and then Nkind (Curr_Obj_Def) = N_Subtype_Indication
12008 and then Present (Constraint (Curr_Obj_Def))
12009 then
12010 declare
12011 Loc : constant Source_Ptr := Sloc (N);
12012 Def_Id : constant Entity_Id := Make_Temporary (Loc, 'S');
12013 Decl : constant Node_Id :=
12014 Make_Subtype_Declaration (Loc,
12015 Defining_Identifier => Def_Id,
12016 Subtype_Indication =>
12017 Relocate_Node (Curr_Obj_Def));
12018
12019 begin
12020 Insert_Before_And_Analyze (N, Decl);
12021 Set_Etype (Id, Def_Id);
12022
12023 if not Subtypes_Statically_Match (Etype (Prev_Id), Def_Id) then
12024 Error_Msg_Sloc := Sloc (Prev_Id);
12025 Error_Msg_N ("subtype does not statically match deferred "
12026 & "declaration #", N);
12027 end if;
12028 end;
12029 end if;
12030 end Check_Possible_Deferred_Completion;
12031
12032 ---------------------------------
12033 -- Check_Recursive_Declaration --
12034 ---------------------------------
12035
12036 procedure Check_Recursive_Declaration (Typ : Entity_Id) is
12037 Comp : Entity_Id;
12038
12039 begin
12040 if Is_Record_Type (Typ) then
12041 Comp := First_Component (Typ);
12042 while Present (Comp) loop
12043 if Comes_From_Source (Comp) then
12044 if Present (Expression (Parent (Comp)))
12045 and then Is_Entity_Name (Expression (Parent (Comp)))
12046 and then Entity (Expression (Parent (Comp))) = Prev
12047 then
12048 Error_Msg_Sloc := Sloc (Parent (Comp));
12049 Error_Msg_NE
12050 ("illegal circularity with declaration for & #",
12051 N, Comp);
12052 return;
12053
12054 elsif Is_Record_Type (Etype (Comp)) then
12055 Check_Recursive_Declaration (Etype (Comp));
12056 end if;
12057 end if;
12058
12059 Next_Component (Comp);
12060 end loop;
12061 end if;
12062 end Check_Recursive_Declaration;
12063
12064 -- Start of processing for Constant_Redeclaration
12065
12066 begin
12067 if Nkind (Parent (Prev)) = N_Object_Declaration then
12068 if Nkind (Object_Definition
12069 (Parent (Prev))) = N_Subtype_Indication
12070 then
12071 -- Find type of new declaration. The constraints of the two
12072 -- views must match statically, but there is no point in
12073 -- creating an itype for the full view.
12074
12075 if Nkind (Obj_Def) = N_Subtype_Indication then
12076 Find_Type (Subtype_Mark (Obj_Def));
12077 New_T := Entity (Subtype_Mark (Obj_Def));
12078
12079 else
12080 Find_Type (Obj_Def);
12081 New_T := Entity (Obj_Def);
12082 end if;
12083
12084 T := Etype (Prev);
12085
12086 else
12087 -- The full view may impose a constraint, even if the partial
12088 -- view does not, so construct the subtype.
12089
12090 New_T := Find_Type_Of_Object (Obj_Def, N);
12091 T := New_T;
12092 end if;
12093
12094 else
12095 -- Current declaration is illegal, diagnosed below in Enter_Name
12096
12097 T := Empty;
12098 New_T := Any_Type;
12099 end if;
12100
12101 -- If previous full declaration or a renaming declaration exists, or if
12102 -- a homograph is present, let Enter_Name handle it, either with an
12103 -- error or with the removal of an overridden implicit subprogram.
12104 -- The previous one is a full declaration if it has an expression
12105 -- (which in the case of an aggregate is indicated by the Init flag).
12106
12107 if Ekind (Prev) /= E_Constant
12108 or else Nkind (Parent (Prev)) = N_Object_Renaming_Declaration
12109 or else Present (Expression (Parent (Prev)))
12110 or else Has_Init_Expression (Parent (Prev))
12111 or else Present (Full_View (Prev))
12112 then
12113 Enter_Name (Id);
12114
12115 -- Verify that types of both declarations match, or else that both types
12116 -- are anonymous access types whose designated subtypes statically match
12117 -- (as allowed in Ada 2005 by AI-385).
12118
12119 elsif Base_Type (Etype (Prev)) /= Base_Type (New_T)
12120 and then
12121 (Ekind (Etype (Prev)) /= E_Anonymous_Access_Type
12122 or else Ekind (Etype (New_T)) /= E_Anonymous_Access_Type
12123 or else Is_Access_Constant (Etype (New_T)) /=
12124 Is_Access_Constant (Etype (Prev))
12125 or else Can_Never_Be_Null (Etype (New_T)) /=
12126 Can_Never_Be_Null (Etype (Prev))
12127 or else Null_Exclusion_Present (Parent (Prev)) /=
12128 Null_Exclusion_Present (Parent (Id))
12129 or else not Subtypes_Statically_Match
12130 (Designated_Type (Etype (Prev)),
12131 Designated_Type (Etype (New_T))))
12132 then
12133 Error_Msg_Sloc := Sloc (Prev);
12134 Error_Msg_N ("type does not match declaration#", N);
12135 Set_Full_View (Prev, Id);
12136 Set_Etype (Id, Any_Type);
12137
12138 -- A deferred constant whose type is an anonymous array is always
12139 -- illegal (unless imported). A detailed error message might be
12140 -- helpful for Ada beginners.
12141
12142 if Nkind (Object_Definition (Parent (Prev)))
12143 = N_Constrained_Array_Definition
12144 and then Nkind (Object_Definition (N))
12145 = N_Constrained_Array_Definition
12146 then
12147 Error_Msg_N ("\each anonymous array is a distinct type", N);
12148 Error_Msg_N ("a deferred constant must have a named type",
12149 Object_Definition (Parent (Prev)));
12150 end if;
12151
12152 elsif
12153 Null_Exclusion_Present (Parent (Prev))
12154 and then not Null_Exclusion_Present (N)
12155 then
12156 Error_Msg_Sloc := Sloc (Prev);
12157 Error_Msg_N ("null-exclusion does not match declaration#", N);
12158 Set_Full_View (Prev, Id);
12159 Set_Etype (Id, Any_Type);
12160
12161 -- If so, process the full constant declaration
12162
12163 else
12164 -- RM 7.4 (6): If the subtype defined by the subtype_indication in
12165 -- the deferred declaration is constrained, then the subtype defined
12166 -- by the subtype_indication in the full declaration shall match it
12167 -- statically.
12168
12169 Check_Possible_Deferred_Completion
12170 (Prev_Id => Prev,
12171 Prev_Obj_Def => Object_Definition (Parent (Prev)),
12172 Curr_Obj_Def => Obj_Def);
12173
12174 Set_Full_View (Prev, Id);
12175 Set_Is_Public (Id, Is_Public (Prev));
12176 Set_Is_Internal (Id);
12177 Append_Entity (Id, Current_Scope);
12178
12179 -- Check ALIASED present if present before (RM 7.4(7))
12180
12181 if Is_Aliased (Prev)
12182 and then not Aliased_Present (N)
12183 then
12184 Error_Msg_Sloc := Sloc (Prev);
12185 Error_Msg_N ("ALIASED required (see declaration #)", N);
12186 end if;
12187
12188 -- Check that placement is in private part and that the incomplete
12189 -- declaration appeared in the visible part.
12190
12191 if Ekind (Current_Scope) = E_Package
12192 and then not In_Private_Part (Current_Scope)
12193 then
12194 Error_Msg_Sloc := Sloc (Prev);
12195 Error_Msg_N
12196 ("full constant for declaration # must be in private part", N);
12197
12198 elsif Ekind (Current_Scope) = E_Package
12199 and then
12200 List_Containing (Parent (Prev)) /=
12201 Visible_Declarations (Package_Specification (Current_Scope))
12202 then
12203 Error_Msg_N
12204 ("deferred constant must be declared in visible part",
12205 Parent (Prev));
12206 end if;
12207
12208 if Is_Access_Type (T)
12209 and then Nkind (Expression (N)) = N_Allocator
12210 then
12211 Check_Recursive_Declaration (Designated_Type (T));
12212 end if;
12213
12214 -- A deferred constant is a visible entity. If type has invariants,
12215 -- verify that the initial value satisfies them.
12216
12217 if Has_Invariants (T) and then Present (Invariant_Procedure (T)) then
12218 Insert_After (N,
12219 Make_Invariant_Call (New_Occurrence_Of (Prev, Sloc (N))));
12220 end if;
12221 end if;
12222 end Constant_Redeclaration;
12223
12224 ----------------------
12225 -- Constrain_Access --
12226 ----------------------
12227
12228 procedure Constrain_Access
12229 (Def_Id : in out Entity_Id;
12230 S : Node_Id;
12231 Related_Nod : Node_Id)
12232 is
12233 T : constant Entity_Id := Entity (Subtype_Mark (S));
12234 Desig_Type : constant Entity_Id := Designated_Type (T);
12235 Desig_Subtype : Entity_Id := Create_Itype (E_Void, Related_Nod);
12236 Constraint_OK : Boolean := True;
12237
12238 begin
12239 if Is_Array_Type (Desig_Type) then
12240 Constrain_Array (Desig_Subtype, S, Related_Nod, Def_Id, 'P');
12241
12242 elsif (Is_Record_Type (Desig_Type)
12243 or else Is_Incomplete_Or_Private_Type (Desig_Type))
12244 and then not Is_Constrained (Desig_Type)
12245 then
12246 -- ??? The following code is a temporary bypass to ignore a
12247 -- discriminant constraint on access type if it is constraining
12248 -- the current record. Avoid creating the implicit subtype of the
12249 -- record we are currently compiling since right now, we cannot
12250 -- handle these. For now, just return the access type itself.
12251
12252 if Desig_Type = Current_Scope
12253 and then No (Def_Id)
12254 then
12255 Set_Ekind (Desig_Subtype, E_Record_Subtype);
12256 Def_Id := Entity (Subtype_Mark (S));
12257
12258 -- This call added to ensure that the constraint is analyzed
12259 -- (needed for a B test). Note that we still return early from
12260 -- this procedure to avoid recursive processing. ???
12261
12262 Constrain_Discriminated_Type
12263 (Desig_Subtype, S, Related_Nod, For_Access => True);
12264 return;
12265 end if;
12266
12267 -- Enforce rule that the constraint is illegal if there is an
12268 -- unconstrained view of the designated type. This means that the
12269 -- partial view (either a private type declaration or a derivation
12270 -- from a private type) has no discriminants. (Defect Report
12271 -- 8652/0008, Technical Corrigendum 1, checked by ACATS B371001).
12272
12273 -- Rule updated for Ada 2005: The private type is said to have
12274 -- a constrained partial view, given that objects of the type
12275 -- can be declared. Furthermore, the rule applies to all access
12276 -- types, unlike the rule concerning default discriminants (see
12277 -- RM 3.7.1(7/3))
12278
12279 if (Ekind (T) = E_General_Access_Type or else Ada_Version >= Ada_2005)
12280 and then Has_Private_Declaration (Desig_Type)
12281 and then In_Open_Scopes (Scope (Desig_Type))
12282 and then Has_Discriminants (Desig_Type)
12283 then
12284 declare
12285 Pack : constant Node_Id :=
12286 Unit_Declaration_Node (Scope (Desig_Type));
12287 Decls : List_Id;
12288 Decl : Node_Id;
12289
12290 begin
12291 if Nkind (Pack) = N_Package_Declaration then
12292 Decls := Visible_Declarations (Specification (Pack));
12293 Decl := First (Decls);
12294 while Present (Decl) loop
12295 if (Nkind (Decl) = N_Private_Type_Declaration
12296 and then Chars (Defining_Identifier (Decl)) =
12297 Chars (Desig_Type))
12298
12299 or else
12300 (Nkind (Decl) = N_Full_Type_Declaration
12301 and then
12302 Chars (Defining_Identifier (Decl)) =
12303 Chars (Desig_Type)
12304 and then Is_Derived_Type (Desig_Type)
12305 and then
12306 Has_Private_Declaration (Etype (Desig_Type)))
12307 then
12308 if No (Discriminant_Specifications (Decl)) then
12309 Error_Msg_N
12310 ("cannot constrain access type if designated "
12311 & "type has constrained partial view", S);
12312 end if;
12313
12314 exit;
12315 end if;
12316
12317 Next (Decl);
12318 end loop;
12319 end if;
12320 end;
12321 end if;
12322
12323 Constrain_Discriminated_Type (Desig_Subtype, S, Related_Nod,
12324 For_Access => True);
12325
12326 elsif Is_Concurrent_Type (Desig_Type)
12327 and then not Is_Constrained (Desig_Type)
12328 then
12329 Constrain_Concurrent (Desig_Subtype, S, Related_Nod, Desig_Type, ' ');
12330
12331 else
12332 Error_Msg_N ("invalid constraint on access type", S);
12333
12334 -- We simply ignore an invalid constraint
12335
12336 Desig_Subtype := Desig_Type;
12337 Constraint_OK := False;
12338 end if;
12339
12340 if No (Def_Id) then
12341 Def_Id := Create_Itype (E_Access_Subtype, Related_Nod);
12342 else
12343 Set_Ekind (Def_Id, E_Access_Subtype);
12344 end if;
12345
12346 if Constraint_OK then
12347 Set_Etype (Def_Id, Base_Type (T));
12348
12349 if Is_Private_Type (Desig_Type) then
12350 Prepare_Private_Subtype_Completion (Desig_Subtype, Related_Nod);
12351 end if;
12352 else
12353 Set_Etype (Def_Id, Any_Type);
12354 end if;
12355
12356 Set_Size_Info (Def_Id, T);
12357 Set_Is_Constrained (Def_Id, Constraint_OK);
12358 Set_Directly_Designated_Type (Def_Id, Desig_Subtype);
12359 Set_Depends_On_Private (Def_Id, Has_Private_Component (Def_Id));
12360 Set_Is_Access_Constant (Def_Id, Is_Access_Constant (T));
12361
12362 Conditional_Delay (Def_Id, T);
12363
12364 -- AI-363 : Subtypes of general access types whose designated types have
12365 -- default discriminants are disallowed. In instances, the rule has to
12366 -- be checked against the actual, of which T is the subtype. In a
12367 -- generic body, the rule is checked assuming that the actual type has
12368 -- defaulted discriminants.
12369
12370 if Ada_Version >= Ada_2005 or else Warn_On_Ada_2005_Compatibility then
12371 if Ekind (Base_Type (T)) = E_General_Access_Type
12372 and then Has_Defaulted_Discriminants (Desig_Type)
12373 then
12374 if Ada_Version < Ada_2005 then
12375 Error_Msg_N
12376 ("access subtype of general access type would not " &
12377 "be allowed in Ada 2005?y?", S);
12378 else
12379 Error_Msg_N
12380 ("access subtype of general access type not allowed", S);
12381 end if;
12382
12383 Error_Msg_N ("\discriminants have defaults", S);
12384
12385 elsif Is_Access_Type (T)
12386 and then Is_Generic_Type (Desig_Type)
12387 and then Has_Discriminants (Desig_Type)
12388 and then In_Package_Body (Current_Scope)
12389 then
12390 if Ada_Version < Ada_2005 then
12391 Error_Msg_N
12392 ("access subtype would not be allowed in generic body "
12393 & "in Ada 2005?y?", S);
12394 else
12395 Error_Msg_N
12396 ("access subtype not allowed in generic body", S);
12397 end if;
12398
12399 Error_Msg_N
12400 ("\designated type is a discriminated formal", S);
12401 end if;
12402 end if;
12403 end Constrain_Access;
12404
12405 ---------------------
12406 -- Constrain_Array --
12407 ---------------------
12408
12409 procedure Constrain_Array
12410 (Def_Id : in out Entity_Id;
12411 SI : Node_Id;
12412 Related_Nod : Node_Id;
12413 Related_Id : Entity_Id;
12414 Suffix : Character)
12415 is
12416 C : constant Node_Id := Constraint (SI);
12417 Number_Of_Constraints : Nat := 0;
12418 Index : Node_Id;
12419 S, T : Entity_Id;
12420 Constraint_OK : Boolean := True;
12421
12422 begin
12423 T := Entity (Subtype_Mark (SI));
12424
12425 if Is_Access_Type (T) then
12426 T := Designated_Type (T);
12427 end if;
12428
12429 -- If an index constraint follows a subtype mark in a subtype indication
12430 -- then the type or subtype denoted by the subtype mark must not already
12431 -- impose an index constraint. The subtype mark must denote either an
12432 -- unconstrained array type or an access type whose designated type
12433 -- is such an array type... (RM 3.6.1)
12434
12435 if Is_Constrained (T) then
12436 Error_Msg_N ("array type is already constrained", Subtype_Mark (SI));
12437 Constraint_OK := False;
12438
12439 else
12440 S := First (Constraints (C));
12441 while Present (S) loop
12442 Number_Of_Constraints := Number_Of_Constraints + 1;
12443 Next (S);
12444 end loop;
12445
12446 -- In either case, the index constraint must provide a discrete
12447 -- range for each index of the array type and the type of each
12448 -- discrete range must be the same as that of the corresponding
12449 -- index. (RM 3.6.1)
12450
12451 if Number_Of_Constraints /= Number_Dimensions (T) then
12452 Error_Msg_NE ("incorrect number of index constraints for }", C, T);
12453 Constraint_OK := False;
12454
12455 else
12456 S := First (Constraints (C));
12457 Index := First_Index (T);
12458 Analyze (Index);
12459
12460 -- Apply constraints to each index type
12461
12462 for J in 1 .. Number_Of_Constraints loop
12463 Constrain_Index (Index, S, Related_Nod, Related_Id, Suffix, J);
12464 Next (Index);
12465 Next (S);
12466 end loop;
12467
12468 end if;
12469 end if;
12470
12471 if No (Def_Id) then
12472 Def_Id :=
12473 Create_Itype (E_Array_Subtype, Related_Nod, Related_Id, Suffix);
12474 Set_Parent (Def_Id, Related_Nod);
12475
12476 else
12477 Set_Ekind (Def_Id, E_Array_Subtype);
12478 end if;
12479
12480 Set_Size_Info (Def_Id, (T));
12481 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
12482 Set_Etype (Def_Id, Base_Type (T));
12483
12484 if Constraint_OK then
12485 Set_First_Index (Def_Id, First (Constraints (C)));
12486 else
12487 Set_First_Index (Def_Id, First_Index (T));
12488 end if;
12489
12490 Set_Is_Constrained (Def_Id, True);
12491 Set_Is_Aliased (Def_Id, Is_Aliased (T));
12492 Set_Depends_On_Private (Def_Id, Has_Private_Component (Def_Id));
12493
12494 Set_Is_Private_Composite (Def_Id, Is_Private_Composite (T));
12495 Set_Is_Limited_Composite (Def_Id, Is_Limited_Composite (T));
12496
12497 -- A subtype does not inherit the Packed_Array_Impl_Type of is parent.
12498 -- We need to initialize the attribute because if Def_Id is previously
12499 -- analyzed through a limited_with clause, it will have the attributes
12500 -- of an incomplete type, one of which is an Elist that overlaps the
12501 -- Packed_Array_Impl_Type field.
12502
12503 Set_Packed_Array_Impl_Type (Def_Id, Empty);
12504
12505 -- Build a freeze node if parent still needs one. Also make sure that
12506 -- the Depends_On_Private status is set because the subtype will need
12507 -- reprocessing at the time the base type does, and also we must set a
12508 -- conditional delay.
12509
12510 Set_Depends_On_Private (Def_Id, Depends_On_Private (T));
12511 Conditional_Delay (Def_Id, T);
12512 end Constrain_Array;
12513
12514 ------------------------------
12515 -- Constrain_Component_Type --
12516 ------------------------------
12517
12518 function Constrain_Component_Type
12519 (Comp : Entity_Id;
12520 Constrained_Typ : Entity_Id;
12521 Related_Node : Node_Id;
12522 Typ : Entity_Id;
12523 Constraints : Elist_Id) return Entity_Id
12524 is
12525 Loc : constant Source_Ptr := Sloc (Constrained_Typ);
12526 Compon_Type : constant Entity_Id := Etype (Comp);
12527
12528 function Build_Constrained_Array_Type
12529 (Old_Type : Entity_Id) return Entity_Id;
12530 -- If Old_Type is an array type, one of whose indexes is constrained
12531 -- by a discriminant, build an Itype whose constraint replaces the
12532 -- discriminant with its value in the constraint.
12533
12534 function Build_Constrained_Discriminated_Type
12535 (Old_Type : Entity_Id) return Entity_Id;
12536 -- Ditto for record components
12537
12538 function Build_Constrained_Access_Type
12539 (Old_Type : Entity_Id) return Entity_Id;
12540 -- Ditto for access types. Makes use of previous two functions, to
12541 -- constrain designated type.
12542
12543 function Build_Subtype (T : Entity_Id; C : List_Id) return Entity_Id;
12544 -- T is an array or discriminated type, C is a list of constraints
12545 -- that apply to T. This routine builds the constrained subtype.
12546
12547 function Is_Discriminant (Expr : Node_Id) return Boolean;
12548 -- Returns True if Expr is a discriminant
12549
12550 function Get_Discr_Value (Discrim : Entity_Id) return Node_Id;
12551 -- Find the value of discriminant Discrim in Constraint
12552
12553 -----------------------------------
12554 -- Build_Constrained_Access_Type --
12555 -----------------------------------
12556
12557 function Build_Constrained_Access_Type
12558 (Old_Type : Entity_Id) return Entity_Id
12559 is
12560 Desig_Type : constant Entity_Id := Designated_Type (Old_Type);
12561 Itype : Entity_Id;
12562 Desig_Subtype : Entity_Id;
12563 Scop : Entity_Id;
12564
12565 begin
12566 -- if the original access type was not embedded in the enclosing
12567 -- type definition, there is no need to produce a new access
12568 -- subtype. In fact every access type with an explicit constraint
12569 -- generates an itype whose scope is the enclosing record.
12570
12571 if not Is_Type (Scope (Old_Type)) then
12572 return Old_Type;
12573
12574 elsif Is_Array_Type (Desig_Type) then
12575 Desig_Subtype := Build_Constrained_Array_Type (Desig_Type);
12576
12577 elsif Has_Discriminants (Desig_Type) then
12578
12579 -- This may be an access type to an enclosing record type for
12580 -- which we are constructing the constrained components. Return
12581 -- the enclosing record subtype. This is not always correct,
12582 -- but avoids infinite recursion. ???
12583
12584 Desig_Subtype := Any_Type;
12585
12586 for J in reverse 0 .. Scope_Stack.Last loop
12587 Scop := Scope_Stack.Table (J).Entity;
12588
12589 if Is_Type (Scop)
12590 and then Base_Type (Scop) = Base_Type (Desig_Type)
12591 then
12592 Desig_Subtype := Scop;
12593 end if;
12594
12595 exit when not Is_Type (Scop);
12596 end loop;
12597
12598 if Desig_Subtype = Any_Type then
12599 Desig_Subtype :=
12600 Build_Constrained_Discriminated_Type (Desig_Type);
12601 end if;
12602
12603 else
12604 return Old_Type;
12605 end if;
12606
12607 if Desig_Subtype /= Desig_Type then
12608
12609 -- The Related_Node better be here or else we won't be able
12610 -- to attach new itypes to a node in the tree.
12611
12612 pragma Assert (Present (Related_Node));
12613
12614 Itype := Create_Itype (E_Access_Subtype, Related_Node);
12615
12616 Set_Etype (Itype, Base_Type (Old_Type));
12617 Set_Size_Info (Itype, (Old_Type));
12618 Set_Directly_Designated_Type (Itype, Desig_Subtype);
12619 Set_Depends_On_Private (Itype, Has_Private_Component
12620 (Old_Type));
12621 Set_Is_Access_Constant (Itype, Is_Access_Constant
12622 (Old_Type));
12623
12624 -- The new itype needs freezing when it depends on a not frozen
12625 -- type and the enclosing subtype needs freezing.
12626
12627 if Has_Delayed_Freeze (Constrained_Typ)
12628 and then not Is_Frozen (Constrained_Typ)
12629 then
12630 Conditional_Delay (Itype, Base_Type (Old_Type));
12631 end if;
12632
12633 return Itype;
12634
12635 else
12636 return Old_Type;
12637 end if;
12638 end Build_Constrained_Access_Type;
12639
12640 ----------------------------------
12641 -- Build_Constrained_Array_Type --
12642 ----------------------------------
12643
12644 function Build_Constrained_Array_Type
12645 (Old_Type : Entity_Id) return Entity_Id
12646 is
12647 Lo_Expr : Node_Id;
12648 Hi_Expr : Node_Id;
12649 Old_Index : Node_Id;
12650 Range_Node : Node_Id;
12651 Constr_List : List_Id;
12652
12653 Need_To_Create_Itype : Boolean := False;
12654
12655 begin
12656 Old_Index := First_Index (Old_Type);
12657 while Present (Old_Index) loop
12658 Get_Index_Bounds (Old_Index, Lo_Expr, Hi_Expr);
12659
12660 if Is_Discriminant (Lo_Expr)
12661 or else
12662 Is_Discriminant (Hi_Expr)
12663 then
12664 Need_To_Create_Itype := True;
12665 end if;
12666
12667 Next_Index (Old_Index);
12668 end loop;
12669
12670 if Need_To_Create_Itype then
12671 Constr_List := New_List;
12672
12673 Old_Index := First_Index (Old_Type);
12674 while Present (Old_Index) loop
12675 Get_Index_Bounds (Old_Index, Lo_Expr, Hi_Expr);
12676
12677 if Is_Discriminant (Lo_Expr) then
12678 Lo_Expr := Get_Discr_Value (Lo_Expr);
12679 end if;
12680
12681 if Is_Discriminant (Hi_Expr) then
12682 Hi_Expr := Get_Discr_Value (Hi_Expr);
12683 end if;
12684
12685 Range_Node :=
12686 Make_Range
12687 (Loc, New_Copy_Tree (Lo_Expr), New_Copy_Tree (Hi_Expr));
12688
12689 Append (Range_Node, To => Constr_List);
12690
12691 Next_Index (Old_Index);
12692 end loop;
12693
12694 return Build_Subtype (Old_Type, Constr_List);
12695
12696 else
12697 return Old_Type;
12698 end if;
12699 end Build_Constrained_Array_Type;
12700
12701 ------------------------------------------
12702 -- Build_Constrained_Discriminated_Type --
12703 ------------------------------------------
12704
12705 function Build_Constrained_Discriminated_Type
12706 (Old_Type : Entity_Id) return Entity_Id
12707 is
12708 Expr : Node_Id;
12709 Constr_List : List_Id;
12710 Old_Constraint : Elmt_Id;
12711
12712 Need_To_Create_Itype : Boolean := False;
12713
12714 begin
12715 Old_Constraint := First_Elmt (Discriminant_Constraint (Old_Type));
12716 while Present (Old_Constraint) loop
12717 Expr := Node (Old_Constraint);
12718
12719 if Is_Discriminant (Expr) then
12720 Need_To_Create_Itype := True;
12721 end if;
12722
12723 Next_Elmt (Old_Constraint);
12724 end loop;
12725
12726 if Need_To_Create_Itype then
12727 Constr_List := New_List;
12728
12729 Old_Constraint := First_Elmt (Discriminant_Constraint (Old_Type));
12730 while Present (Old_Constraint) loop
12731 Expr := Node (Old_Constraint);
12732
12733 if Is_Discriminant (Expr) then
12734 Expr := Get_Discr_Value (Expr);
12735 end if;
12736
12737 Append (New_Copy_Tree (Expr), To => Constr_List);
12738
12739 Next_Elmt (Old_Constraint);
12740 end loop;
12741
12742 return Build_Subtype (Old_Type, Constr_List);
12743
12744 else
12745 return Old_Type;
12746 end if;
12747 end Build_Constrained_Discriminated_Type;
12748
12749 -------------------
12750 -- Build_Subtype --
12751 -------------------
12752
12753 function Build_Subtype (T : Entity_Id; C : List_Id) return Entity_Id is
12754 Indic : Node_Id;
12755 Subtyp_Decl : Node_Id;
12756 Def_Id : Entity_Id;
12757 Btyp : Entity_Id := Base_Type (T);
12758
12759 begin
12760 -- The Related_Node better be here or else we won't be able to
12761 -- attach new itypes to a node in the tree.
12762
12763 pragma Assert (Present (Related_Node));
12764
12765 -- If the view of the component's type is incomplete or private
12766 -- with unknown discriminants, then the constraint must be applied
12767 -- to the full type.
12768
12769 if Has_Unknown_Discriminants (Btyp)
12770 and then Present (Underlying_Type (Btyp))
12771 then
12772 Btyp := Underlying_Type (Btyp);
12773 end if;
12774
12775 Indic :=
12776 Make_Subtype_Indication (Loc,
12777 Subtype_Mark => New_Occurrence_Of (Btyp, Loc),
12778 Constraint => Make_Index_Or_Discriminant_Constraint (Loc, C));
12779
12780 Def_Id := Create_Itype (Ekind (T), Related_Node);
12781
12782 Subtyp_Decl :=
12783 Make_Subtype_Declaration (Loc,
12784 Defining_Identifier => Def_Id,
12785 Subtype_Indication => Indic);
12786
12787 Set_Parent (Subtyp_Decl, Parent (Related_Node));
12788
12789 -- Itypes must be analyzed with checks off (see package Itypes)
12790
12791 Analyze (Subtyp_Decl, Suppress => All_Checks);
12792
12793 return Def_Id;
12794 end Build_Subtype;
12795
12796 ---------------------
12797 -- Get_Discr_Value --
12798 ---------------------
12799
12800 function Get_Discr_Value (Discrim : Entity_Id) return Node_Id is
12801 D : Entity_Id;
12802 E : Elmt_Id;
12803
12804 begin
12805 -- The discriminant may be declared for the type, in which case we
12806 -- find it by iterating over the list of discriminants. If the
12807 -- discriminant is inherited from a parent type, it appears as the
12808 -- corresponding discriminant of the current type. This will be the
12809 -- case when constraining an inherited component whose constraint is
12810 -- given by a discriminant of the parent.
12811
12812 D := First_Discriminant (Typ);
12813 E := First_Elmt (Constraints);
12814
12815 while Present (D) loop
12816 if D = Entity (Discrim)
12817 or else D = CR_Discriminant (Entity (Discrim))
12818 or else Corresponding_Discriminant (D) = Entity (Discrim)
12819 then
12820 return Node (E);
12821 end if;
12822
12823 Next_Discriminant (D);
12824 Next_Elmt (E);
12825 end loop;
12826
12827 -- The Corresponding_Discriminant mechanism is incomplete, because
12828 -- the correspondence between new and old discriminants is not one
12829 -- to one: one new discriminant can constrain several old ones. In
12830 -- that case, scan sequentially the stored_constraint, the list of
12831 -- discriminants of the parents, and the constraints.
12832
12833 -- Previous code checked for the present of the Stored_Constraint
12834 -- list for the derived type, but did not use it at all. Should it
12835 -- be present when the component is a discriminated task type?
12836
12837 if Is_Derived_Type (Typ)
12838 and then Scope (Entity (Discrim)) = Etype (Typ)
12839 then
12840 D := First_Discriminant (Etype (Typ));
12841 E := First_Elmt (Constraints);
12842 while Present (D) loop
12843 if D = Entity (Discrim) then
12844 return Node (E);
12845 end if;
12846
12847 Next_Discriminant (D);
12848 Next_Elmt (E);
12849 end loop;
12850 end if;
12851
12852 -- Something is wrong if we did not find the value
12853
12854 raise Program_Error;
12855 end Get_Discr_Value;
12856
12857 ---------------------
12858 -- Is_Discriminant --
12859 ---------------------
12860
12861 function Is_Discriminant (Expr : Node_Id) return Boolean is
12862 Discrim_Scope : Entity_Id;
12863
12864 begin
12865 if Denotes_Discriminant (Expr) then
12866 Discrim_Scope := Scope (Entity (Expr));
12867
12868 -- Either we have a reference to one of Typ's discriminants,
12869
12870 pragma Assert (Discrim_Scope = Typ
12871
12872 -- or to the discriminants of the parent type, in the case
12873 -- of a derivation of a tagged type with variants.
12874
12875 or else Discrim_Scope = Etype (Typ)
12876 or else Full_View (Discrim_Scope) = Etype (Typ)
12877
12878 -- or same as above for the case where the discriminants
12879 -- were declared in Typ's private view.
12880
12881 or else (Is_Private_Type (Discrim_Scope)
12882 and then Chars (Discrim_Scope) = Chars (Typ))
12883
12884 -- or else we are deriving from the full view and the
12885 -- discriminant is declared in the private entity.
12886
12887 or else (Is_Private_Type (Typ)
12888 and then Chars (Discrim_Scope) = Chars (Typ))
12889
12890 -- Or we are constrained the corresponding record of a
12891 -- synchronized type that completes a private declaration.
12892
12893 or else (Is_Concurrent_Record_Type (Typ)
12894 and then
12895 Corresponding_Concurrent_Type (Typ) = Discrim_Scope)
12896
12897 -- or we have a class-wide type, in which case make sure the
12898 -- discriminant found belongs to the root type.
12899
12900 or else (Is_Class_Wide_Type (Typ)
12901 and then Etype (Typ) = Discrim_Scope));
12902
12903 return True;
12904 end if;
12905
12906 -- In all other cases we have something wrong
12907
12908 return False;
12909 end Is_Discriminant;
12910
12911 -- Start of processing for Constrain_Component_Type
12912
12913 begin
12914 if Nkind (Parent (Comp)) = N_Component_Declaration
12915 and then Comes_From_Source (Parent (Comp))
12916 and then Comes_From_Source
12917 (Subtype_Indication (Component_Definition (Parent (Comp))))
12918 and then
12919 Is_Entity_Name
12920 (Subtype_Indication (Component_Definition (Parent (Comp))))
12921 then
12922 return Compon_Type;
12923
12924 elsif Is_Array_Type (Compon_Type) then
12925 return Build_Constrained_Array_Type (Compon_Type);
12926
12927 elsif Has_Discriminants (Compon_Type) then
12928 return Build_Constrained_Discriminated_Type (Compon_Type);
12929
12930 elsif Is_Access_Type (Compon_Type) then
12931 return Build_Constrained_Access_Type (Compon_Type);
12932
12933 else
12934 return Compon_Type;
12935 end if;
12936 end Constrain_Component_Type;
12937
12938 --------------------------
12939 -- Constrain_Concurrent --
12940 --------------------------
12941
12942 -- For concurrent types, the associated record value type carries the same
12943 -- discriminants, so when we constrain a concurrent type, we must constrain
12944 -- the corresponding record type as well.
12945
12946 procedure Constrain_Concurrent
12947 (Def_Id : in out Entity_Id;
12948 SI : Node_Id;
12949 Related_Nod : Node_Id;
12950 Related_Id : Entity_Id;
12951 Suffix : Character)
12952 is
12953 -- Retrieve Base_Type to ensure getting to the concurrent type in the
12954 -- case of a private subtype (needed when only doing semantic analysis).
12955
12956 T_Ent : Entity_Id := Base_Type (Entity (Subtype_Mark (SI)));
12957 T_Val : Entity_Id;
12958
12959 begin
12960 if Is_Access_Type (T_Ent) then
12961 T_Ent := Designated_Type (T_Ent);
12962 end if;
12963
12964 T_Val := Corresponding_Record_Type (T_Ent);
12965
12966 if Present (T_Val) then
12967
12968 if No (Def_Id) then
12969 Def_Id := Create_Itype (E_Void, Related_Nod, Related_Id, Suffix);
12970
12971 -- Elaborate itype now, as it may be used in a subsequent
12972 -- synchronized operation in another scope.
12973
12974 if Nkind (Related_Nod) = N_Full_Type_Declaration then
12975 Build_Itype_Reference (Def_Id, Related_Nod);
12976 end if;
12977 end if;
12978
12979 Constrain_Discriminated_Type (Def_Id, SI, Related_Nod);
12980
12981 Set_Depends_On_Private (Def_Id, Has_Private_Component (Def_Id));
12982 Set_Corresponding_Record_Type (Def_Id,
12983 Constrain_Corresponding_Record (Def_Id, T_Val, Related_Nod));
12984
12985 else
12986 -- If there is no associated record, expansion is disabled and this
12987 -- is a generic context. Create a subtype in any case, so that
12988 -- semantic analysis can proceed.
12989
12990 if No (Def_Id) then
12991 Def_Id := Create_Itype (E_Void, Related_Nod, Related_Id, Suffix);
12992 end if;
12993
12994 Constrain_Discriminated_Type (Def_Id, SI, Related_Nod);
12995 end if;
12996 end Constrain_Concurrent;
12997
12998 ------------------------------------
12999 -- Constrain_Corresponding_Record --
13000 ------------------------------------
13001
13002 function Constrain_Corresponding_Record
13003 (Prot_Subt : Entity_Id;
13004 Corr_Rec : Entity_Id;
13005 Related_Nod : Node_Id) return Entity_Id
13006 is
13007 T_Sub : constant Entity_Id :=
13008 Create_Itype (E_Record_Subtype, Related_Nod, Corr_Rec, 'C');
13009
13010 begin
13011 Set_Etype (T_Sub, Corr_Rec);
13012 Set_Has_Discriminants (T_Sub, Has_Discriminants (Prot_Subt));
13013 Set_Is_Constrained (T_Sub, True);
13014 Set_First_Entity (T_Sub, First_Entity (Corr_Rec));
13015 Set_Last_Entity (T_Sub, Last_Entity (Corr_Rec));
13016
13017 if Has_Discriminants (Prot_Subt) then -- False only if errors.
13018 Set_Discriminant_Constraint
13019 (T_Sub, Discriminant_Constraint (Prot_Subt));
13020 Set_Stored_Constraint_From_Discriminant_Constraint (T_Sub);
13021 Create_Constrained_Components
13022 (T_Sub, Related_Nod, Corr_Rec, Discriminant_Constraint (T_Sub));
13023 end if;
13024
13025 Set_Depends_On_Private (T_Sub, Has_Private_Component (T_Sub));
13026
13027 if Ekind (Scope (Prot_Subt)) /= E_Record_Type then
13028 Conditional_Delay (T_Sub, Corr_Rec);
13029
13030 else
13031 -- This is a component subtype: it will be frozen in the context of
13032 -- the enclosing record's init_proc, so that discriminant references
13033 -- are resolved to discriminals. (Note: we used to skip freezing
13034 -- altogether in that case, which caused errors downstream for
13035 -- components of a bit packed array type).
13036
13037 Set_Has_Delayed_Freeze (T_Sub);
13038 end if;
13039
13040 return T_Sub;
13041 end Constrain_Corresponding_Record;
13042
13043 -----------------------
13044 -- Constrain_Decimal --
13045 -----------------------
13046
13047 procedure Constrain_Decimal (Def_Id : Node_Id; S : Node_Id) is
13048 T : constant Entity_Id := Entity (Subtype_Mark (S));
13049 C : constant Node_Id := Constraint (S);
13050 Loc : constant Source_Ptr := Sloc (C);
13051 Range_Expr : Node_Id;
13052 Digits_Expr : Node_Id;
13053 Digits_Val : Uint;
13054 Bound_Val : Ureal;
13055
13056 begin
13057 Set_Ekind (Def_Id, E_Decimal_Fixed_Point_Subtype);
13058
13059 if Nkind (C) = N_Range_Constraint then
13060 Range_Expr := Range_Expression (C);
13061 Digits_Val := Digits_Value (T);
13062
13063 else
13064 pragma Assert (Nkind (C) = N_Digits_Constraint);
13065
13066 Check_SPARK_05_Restriction ("digits constraint is not allowed", S);
13067
13068 Digits_Expr := Digits_Expression (C);
13069 Analyze_And_Resolve (Digits_Expr, Any_Integer);
13070
13071 Check_Digits_Expression (Digits_Expr);
13072 Digits_Val := Expr_Value (Digits_Expr);
13073
13074 if Digits_Val > Digits_Value (T) then
13075 Error_Msg_N
13076 ("digits expression is incompatible with subtype", C);
13077 Digits_Val := Digits_Value (T);
13078 end if;
13079
13080 if Present (Range_Constraint (C)) then
13081 Range_Expr := Range_Expression (Range_Constraint (C));
13082 else
13083 Range_Expr := Empty;
13084 end if;
13085 end if;
13086
13087 Set_Etype (Def_Id, Base_Type (T));
13088 Set_Size_Info (Def_Id, (T));
13089 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
13090 Set_Delta_Value (Def_Id, Delta_Value (T));
13091 Set_Scale_Value (Def_Id, Scale_Value (T));
13092 Set_Small_Value (Def_Id, Small_Value (T));
13093 Set_Machine_Radix_10 (Def_Id, Machine_Radix_10 (T));
13094 Set_Digits_Value (Def_Id, Digits_Val);
13095
13096 -- Manufacture range from given digits value if no range present
13097
13098 if No (Range_Expr) then
13099 Bound_Val := (Ureal_10 ** Digits_Val - Ureal_1) * Small_Value (T);
13100 Range_Expr :=
13101 Make_Range (Loc,
13102 Low_Bound =>
13103 Convert_To (T, Make_Real_Literal (Loc, (-Bound_Val))),
13104 High_Bound =>
13105 Convert_To (T, Make_Real_Literal (Loc, Bound_Val)));
13106 end if;
13107
13108 Set_Scalar_Range_For_Subtype (Def_Id, Range_Expr, T);
13109 Set_Discrete_RM_Size (Def_Id);
13110
13111 -- Unconditionally delay the freeze, since we cannot set size
13112 -- information in all cases correctly until the freeze point.
13113
13114 Set_Has_Delayed_Freeze (Def_Id);
13115 end Constrain_Decimal;
13116
13117 ----------------------------------
13118 -- Constrain_Discriminated_Type --
13119 ----------------------------------
13120
13121 procedure Constrain_Discriminated_Type
13122 (Def_Id : Entity_Id;
13123 S : Node_Id;
13124 Related_Nod : Node_Id;
13125 For_Access : Boolean := False)
13126 is
13127 E : Entity_Id := Entity (Subtype_Mark (S));
13128 T : Entity_Id;
13129
13130 procedure Fixup_Bad_Constraint;
13131 -- Called after finding a bad constraint, and after having posted an
13132 -- appropriate error message. The goal is to leave type Def_Id in as
13133 -- reasonable state as possible.
13134
13135 --------------------------
13136 -- Fixup_Bad_Constraint --
13137 --------------------------
13138
13139 procedure Fixup_Bad_Constraint is
13140 begin
13141 -- Set a reasonable Ekind for the entity. For an incomplete type,
13142 -- we can't do much, but for other types, we can set the proper
13143 -- corresponding subtype kind.
13144
13145 if Ekind (T) = E_Incomplete_Type then
13146 Set_Ekind (Def_Id, Ekind (T));
13147 else
13148 Set_Ekind (Def_Id, Subtype_Kind (Ekind (T)));
13149 end if;
13150
13151 -- Set Etype to the known type, to reduce chances of cascaded errors
13152
13153 Set_Etype (Def_Id, E);
13154 Set_Error_Posted (Def_Id);
13155 end Fixup_Bad_Constraint;
13156
13157 -- Local variables
13158
13159 C : Node_Id;
13160 Constr : Elist_Id := New_Elmt_List;
13161
13162 -- Start of processing for Constrain_Discriminated_Type
13163
13164 begin
13165 C := Constraint (S);
13166
13167 -- A discriminant constraint is only allowed in a subtype indication,
13168 -- after a subtype mark. This subtype mark must denote either a type
13169 -- with discriminants, or an access type whose designated type is a
13170 -- type with discriminants. A discriminant constraint specifies the
13171 -- values of these discriminants (RM 3.7.2(5)).
13172
13173 T := Base_Type (Entity (Subtype_Mark (S)));
13174
13175 if Is_Access_Type (T) then
13176 T := Designated_Type (T);
13177 end if;
13178
13179 -- In an instance it may be necessary to retrieve the full view of a
13180 -- type with unknown discriminants, or a full view with defaulted
13181 -- discriminants. In other contexts the constraint is illegal.
13182
13183 if In_Instance
13184 and then Is_Private_Type (T)
13185 and then Present (Full_View (T))
13186 and then
13187 (Has_Unknown_Discriminants (T)
13188 or else
13189 (not Has_Discriminants (T)
13190 and then Has_Discriminants (Full_View (T))
13191 and then Present (Discriminant_Default_Value
13192 (First_Discriminant (Full_View (T))))))
13193 then
13194 T := Full_View (T);
13195 E := Full_View (E);
13196 end if;
13197
13198 -- Ada 2005 (AI-412): Constrained incomplete subtypes are illegal. Avoid
13199 -- generating an error for access-to-incomplete subtypes.
13200
13201 if Ada_Version >= Ada_2005
13202 and then Ekind (T) = E_Incomplete_Type
13203 and then Nkind (Parent (S)) = N_Subtype_Declaration
13204 and then not Is_Itype (Def_Id)
13205 then
13206 -- A little sanity check: emit an error message if the type has
13207 -- discriminants to begin with. Type T may be a regular incomplete
13208 -- type or imported via a limited with clause.
13209
13210 if Has_Discriminants (T)
13211 or else (From_Limited_With (T)
13212 and then Present (Non_Limited_View (T))
13213 and then Nkind (Parent (Non_Limited_View (T))) =
13214 N_Full_Type_Declaration
13215 and then Present (Discriminant_Specifications
13216 (Parent (Non_Limited_View (T)))))
13217 then
13218 Error_Msg_N
13219 ("(Ada 2005) incomplete subtype may not be constrained", C);
13220 else
13221 Error_Msg_N ("invalid constraint: type has no discriminant", C);
13222 end if;
13223
13224 Fixup_Bad_Constraint;
13225 return;
13226
13227 -- Check that the type has visible discriminants. The type may be
13228 -- a private type with unknown discriminants whose full view has
13229 -- discriminants which are invisible.
13230
13231 elsif not Has_Discriminants (T)
13232 or else
13233 (Has_Unknown_Discriminants (T)
13234 and then Is_Private_Type (T))
13235 then
13236 Error_Msg_N ("invalid constraint: type has no discriminant", C);
13237 Fixup_Bad_Constraint;
13238 return;
13239
13240 elsif Is_Constrained (E)
13241 or else (Ekind (E) = E_Class_Wide_Subtype
13242 and then Present (Discriminant_Constraint (E)))
13243 then
13244 Error_Msg_N ("type is already constrained", Subtype_Mark (S));
13245 Fixup_Bad_Constraint;
13246 return;
13247 end if;
13248
13249 -- T may be an unconstrained subtype (e.g. a generic actual). Constraint
13250 -- applies to the base type.
13251
13252 T := Base_Type (T);
13253
13254 Constr := Build_Discriminant_Constraints (T, S);
13255
13256 -- If the list returned was empty we had an error in building the
13257 -- discriminant constraint. We have also already signalled an error
13258 -- in the incomplete type case
13259
13260 if Is_Empty_Elmt_List (Constr) then
13261 Fixup_Bad_Constraint;
13262 return;
13263 end if;
13264
13265 Build_Discriminated_Subtype (T, Def_Id, Constr, Related_Nod, For_Access);
13266 end Constrain_Discriminated_Type;
13267
13268 ---------------------------
13269 -- Constrain_Enumeration --
13270 ---------------------------
13271
13272 procedure Constrain_Enumeration (Def_Id : Node_Id; S : Node_Id) is
13273 T : constant Entity_Id := Entity (Subtype_Mark (S));
13274 C : constant Node_Id := Constraint (S);
13275
13276 begin
13277 Set_Ekind (Def_Id, E_Enumeration_Subtype);
13278
13279 Set_First_Literal (Def_Id, First_Literal (Base_Type (T)));
13280
13281 Set_Etype (Def_Id, Base_Type (T));
13282 Set_Size_Info (Def_Id, (T));
13283 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
13284 Set_Is_Character_Type (Def_Id, Is_Character_Type (T));
13285
13286 Set_Scalar_Range_For_Subtype (Def_Id, Range_Expression (C), T);
13287
13288 Set_Discrete_RM_Size (Def_Id);
13289 end Constrain_Enumeration;
13290
13291 ----------------------
13292 -- Constrain_Float --
13293 ----------------------
13294
13295 procedure Constrain_Float (Def_Id : Node_Id; S : Node_Id) is
13296 T : constant Entity_Id := Entity (Subtype_Mark (S));
13297 C : Node_Id;
13298 D : Node_Id;
13299 Rais : Node_Id;
13300
13301 begin
13302 Set_Ekind (Def_Id, E_Floating_Point_Subtype);
13303
13304 Set_Etype (Def_Id, Base_Type (T));
13305 Set_Size_Info (Def_Id, (T));
13306 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
13307
13308 -- Process the constraint
13309
13310 C := Constraint (S);
13311
13312 -- Digits constraint present
13313
13314 if Nkind (C) = N_Digits_Constraint then
13315
13316 Check_SPARK_05_Restriction ("digits constraint is not allowed", S);
13317 Check_Restriction (No_Obsolescent_Features, C);
13318
13319 if Warn_On_Obsolescent_Feature then
13320 Error_Msg_N
13321 ("subtype digits constraint is an " &
13322 "obsolescent feature (RM J.3(8))?j?", C);
13323 end if;
13324
13325 D := Digits_Expression (C);
13326 Analyze_And_Resolve (D, Any_Integer);
13327 Check_Digits_Expression (D);
13328 Set_Digits_Value (Def_Id, Expr_Value (D));
13329
13330 -- Check that digits value is in range. Obviously we can do this
13331 -- at compile time, but it is strictly a runtime check, and of
13332 -- course there is an ACVC test that checks this.
13333
13334 if Digits_Value (Def_Id) > Digits_Value (T) then
13335 Error_Msg_Uint_1 := Digits_Value (T);
13336 Error_Msg_N ("??digits value is too large, maximum is ^", D);
13337 Rais :=
13338 Make_Raise_Constraint_Error (Sloc (D),
13339 Reason => CE_Range_Check_Failed);
13340 Insert_Action (Declaration_Node (Def_Id), Rais);
13341 end if;
13342
13343 C := Range_Constraint (C);
13344
13345 -- No digits constraint present
13346
13347 else
13348 Set_Digits_Value (Def_Id, Digits_Value (T));
13349 end if;
13350
13351 -- Range constraint present
13352
13353 if Nkind (C) = N_Range_Constraint then
13354 Set_Scalar_Range_For_Subtype (Def_Id, Range_Expression (C), T);
13355
13356 -- No range constraint present
13357
13358 else
13359 pragma Assert (No (C));
13360 Set_Scalar_Range (Def_Id, Scalar_Range (T));
13361 end if;
13362
13363 Set_Is_Constrained (Def_Id);
13364 end Constrain_Float;
13365
13366 ---------------------
13367 -- Constrain_Index --
13368 ---------------------
13369
13370 procedure Constrain_Index
13371 (Index : Node_Id;
13372 S : Node_Id;
13373 Related_Nod : Node_Id;
13374 Related_Id : Entity_Id;
13375 Suffix : Character;
13376 Suffix_Index : Nat)
13377 is
13378 Def_Id : Entity_Id;
13379 R : Node_Id := Empty;
13380 T : constant Entity_Id := Etype (Index);
13381
13382 begin
13383 Def_Id :=
13384 Create_Itype (E_Void, Related_Nod, Related_Id, Suffix, Suffix_Index);
13385 Set_Etype (Def_Id, Base_Type (T));
13386
13387 if Nkind (S) = N_Range
13388 or else
13389 (Nkind (S) = N_Attribute_Reference
13390 and then Attribute_Name (S) = Name_Range)
13391 then
13392 -- A Range attribute will be transformed into N_Range by Resolve
13393
13394 Analyze (S);
13395 Set_Etype (S, T);
13396 R := S;
13397
13398 Process_Range_Expr_In_Decl (R, T);
13399
13400 if not Error_Posted (S)
13401 and then
13402 (Nkind (S) /= N_Range
13403 or else not Covers (T, (Etype (Low_Bound (S))))
13404 or else not Covers (T, (Etype (High_Bound (S)))))
13405 then
13406 if Base_Type (T) /= Any_Type
13407 and then Etype (Low_Bound (S)) /= Any_Type
13408 and then Etype (High_Bound (S)) /= Any_Type
13409 then
13410 Error_Msg_N ("range expected", S);
13411 end if;
13412 end if;
13413
13414 elsif Nkind (S) = N_Subtype_Indication then
13415
13416 -- The parser has verified that this is a discrete indication
13417
13418 Resolve_Discrete_Subtype_Indication (S, T);
13419 Bad_Predicated_Subtype_Use
13420 ("subtype& has predicate, not allowed in index constraint",
13421 S, Entity (Subtype_Mark (S)));
13422
13423 R := Range_Expression (Constraint (S));
13424
13425 -- Capture values of bounds and generate temporaries for them if
13426 -- needed, since checks may cause duplication of the expressions
13427 -- which must not be reevaluated.
13428
13429 -- The forced evaluation removes side effects from expressions, which
13430 -- should occur also in GNATprove mode. Otherwise, we end up with
13431 -- unexpected insertions of actions at places where this is not
13432 -- supposed to occur, e.g. on default parameters of a call.
13433
13434 if Expander_Active or GNATprove_Mode then
13435 Force_Evaluation
13436 (Low_Bound (R), Related_Id => Def_Id, Is_Low_Bound => True);
13437 Force_Evaluation
13438 (High_Bound (R), Related_Id => Def_Id, Is_High_Bound => True);
13439 end if;
13440
13441 elsif Nkind (S) = N_Discriminant_Association then
13442
13443 -- Syntactically valid in subtype indication
13444
13445 Error_Msg_N ("invalid index constraint", S);
13446 Rewrite (S, New_Occurrence_Of (T, Sloc (S)));
13447 return;
13448
13449 -- Subtype_Mark case, no anonymous subtypes to construct
13450
13451 else
13452 Analyze (S);
13453
13454 if Is_Entity_Name (S) then
13455 if not Is_Type (Entity (S)) then
13456 Error_Msg_N ("expect subtype mark for index constraint", S);
13457
13458 elsif Base_Type (Entity (S)) /= Base_Type (T) then
13459 Wrong_Type (S, Base_Type (T));
13460
13461 -- Check error of subtype with predicate in index constraint
13462
13463 else
13464 Bad_Predicated_Subtype_Use
13465 ("subtype& has predicate, not allowed in index constraint",
13466 S, Entity (S));
13467 end if;
13468
13469 return;
13470
13471 else
13472 Error_Msg_N ("invalid index constraint", S);
13473 Rewrite (S, New_Occurrence_Of (T, Sloc (S)));
13474 return;
13475 end if;
13476 end if;
13477
13478 -- Complete construction of the Itype
13479
13480 if Is_Modular_Integer_Type (T) then
13481 Set_Ekind (Def_Id, E_Modular_Integer_Subtype);
13482
13483 elsif Is_Integer_Type (T) then
13484 Set_Ekind (Def_Id, E_Signed_Integer_Subtype);
13485
13486 else
13487 Set_Ekind (Def_Id, E_Enumeration_Subtype);
13488 Set_Is_Character_Type (Def_Id, Is_Character_Type (T));
13489 Set_First_Literal (Def_Id, First_Literal (T));
13490 end if;
13491
13492 Set_Size_Info (Def_Id, (T));
13493 Set_RM_Size (Def_Id, RM_Size (T));
13494 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
13495
13496 Set_Scalar_Range (Def_Id, R);
13497
13498 Set_Etype (S, Def_Id);
13499 Set_Discrete_RM_Size (Def_Id);
13500 end Constrain_Index;
13501
13502 -----------------------
13503 -- Constrain_Integer --
13504 -----------------------
13505
13506 procedure Constrain_Integer (Def_Id : Node_Id; S : Node_Id) is
13507 T : constant Entity_Id := Entity (Subtype_Mark (S));
13508 C : constant Node_Id := Constraint (S);
13509
13510 begin
13511 Set_Scalar_Range_For_Subtype (Def_Id, Range_Expression (C), T);
13512
13513 if Is_Modular_Integer_Type (T) then
13514 Set_Ekind (Def_Id, E_Modular_Integer_Subtype);
13515 else
13516 Set_Ekind (Def_Id, E_Signed_Integer_Subtype);
13517 end if;
13518
13519 Set_Etype (Def_Id, Base_Type (T));
13520 Set_Size_Info (Def_Id, (T));
13521 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
13522 Set_Discrete_RM_Size (Def_Id);
13523 end Constrain_Integer;
13524
13525 ------------------------------
13526 -- Constrain_Ordinary_Fixed --
13527 ------------------------------
13528
13529 procedure Constrain_Ordinary_Fixed (Def_Id : Node_Id; S : Node_Id) is
13530 T : constant Entity_Id := Entity (Subtype_Mark (S));
13531 C : Node_Id;
13532 D : Node_Id;
13533 Rais : Node_Id;
13534
13535 begin
13536 Set_Ekind (Def_Id, E_Ordinary_Fixed_Point_Subtype);
13537 Set_Etype (Def_Id, Base_Type (T));
13538 Set_Size_Info (Def_Id, (T));
13539 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
13540 Set_Small_Value (Def_Id, Small_Value (T));
13541
13542 -- Process the constraint
13543
13544 C := Constraint (S);
13545
13546 -- Delta constraint present
13547
13548 if Nkind (C) = N_Delta_Constraint then
13549
13550 Check_SPARK_05_Restriction ("delta constraint is not allowed", S);
13551 Check_Restriction (No_Obsolescent_Features, C);
13552
13553 if Warn_On_Obsolescent_Feature then
13554 Error_Msg_S
13555 ("subtype delta constraint is an " &
13556 "obsolescent feature (RM J.3(7))?j?");
13557 end if;
13558
13559 D := Delta_Expression (C);
13560 Analyze_And_Resolve (D, Any_Real);
13561 Check_Delta_Expression (D);
13562 Set_Delta_Value (Def_Id, Expr_Value_R (D));
13563
13564 -- Check that delta value is in range. Obviously we can do this
13565 -- at compile time, but it is strictly a runtime check, and of
13566 -- course there is an ACVC test that checks this.
13567
13568 if Delta_Value (Def_Id) < Delta_Value (T) then
13569 Error_Msg_N ("??delta value is too small", D);
13570 Rais :=
13571 Make_Raise_Constraint_Error (Sloc (D),
13572 Reason => CE_Range_Check_Failed);
13573 Insert_Action (Declaration_Node (Def_Id), Rais);
13574 end if;
13575
13576 C := Range_Constraint (C);
13577
13578 -- No delta constraint present
13579
13580 else
13581 Set_Delta_Value (Def_Id, Delta_Value (T));
13582 end if;
13583
13584 -- Range constraint present
13585
13586 if Nkind (C) = N_Range_Constraint then
13587 Set_Scalar_Range_For_Subtype (Def_Id, Range_Expression (C), T);
13588
13589 -- No range constraint present
13590
13591 else
13592 pragma Assert (No (C));
13593 Set_Scalar_Range (Def_Id, Scalar_Range (T));
13594 end if;
13595
13596 Set_Discrete_RM_Size (Def_Id);
13597
13598 -- Unconditionally delay the freeze, since we cannot set size
13599 -- information in all cases correctly until the freeze point.
13600
13601 Set_Has_Delayed_Freeze (Def_Id);
13602 end Constrain_Ordinary_Fixed;
13603
13604 -----------------------
13605 -- Contain_Interface --
13606 -----------------------
13607
13608 function Contain_Interface
13609 (Iface : Entity_Id;
13610 Ifaces : Elist_Id) return Boolean
13611 is
13612 Iface_Elmt : Elmt_Id;
13613
13614 begin
13615 if Present (Ifaces) then
13616 Iface_Elmt := First_Elmt (Ifaces);
13617 while Present (Iface_Elmt) loop
13618 if Node (Iface_Elmt) = Iface then
13619 return True;
13620 end if;
13621
13622 Next_Elmt (Iface_Elmt);
13623 end loop;
13624 end if;
13625
13626 return False;
13627 end Contain_Interface;
13628
13629 ---------------------------
13630 -- Convert_Scalar_Bounds --
13631 ---------------------------
13632
13633 procedure Convert_Scalar_Bounds
13634 (N : Node_Id;
13635 Parent_Type : Entity_Id;
13636 Derived_Type : Entity_Id;
13637 Loc : Source_Ptr)
13638 is
13639 Implicit_Base : constant Entity_Id := Base_Type (Derived_Type);
13640
13641 Lo : Node_Id;
13642 Hi : Node_Id;
13643 Rng : Node_Id;
13644
13645 begin
13646 -- Defend against previous errors
13647
13648 if No (Scalar_Range (Derived_Type)) then
13649 Check_Error_Detected;
13650 return;
13651 end if;
13652
13653 Lo := Build_Scalar_Bound
13654 (Type_Low_Bound (Derived_Type),
13655 Parent_Type, Implicit_Base);
13656
13657 Hi := Build_Scalar_Bound
13658 (Type_High_Bound (Derived_Type),
13659 Parent_Type, Implicit_Base);
13660
13661 Rng :=
13662 Make_Range (Loc,
13663 Low_Bound => Lo,
13664 High_Bound => Hi);
13665
13666 Set_Includes_Infinities (Rng, Has_Infinities (Derived_Type));
13667
13668 Set_Parent (Rng, N);
13669 Set_Scalar_Range (Derived_Type, Rng);
13670
13671 -- Analyze the bounds
13672
13673 Analyze_And_Resolve (Lo, Implicit_Base);
13674 Analyze_And_Resolve (Hi, Implicit_Base);
13675
13676 -- Analyze the range itself, except that we do not analyze it if
13677 -- the bounds are real literals, and we have a fixed-point type.
13678 -- The reason for this is that we delay setting the bounds in this
13679 -- case till we know the final Small and Size values (see circuit
13680 -- in Freeze.Freeze_Fixed_Point_Type for further details).
13681
13682 if Is_Fixed_Point_Type (Parent_Type)
13683 and then Nkind (Lo) = N_Real_Literal
13684 and then Nkind (Hi) = N_Real_Literal
13685 then
13686 return;
13687
13688 -- Here we do the analysis of the range
13689
13690 -- Note: we do this manually, since if we do a normal Analyze and
13691 -- Resolve call, there are problems with the conversions used for
13692 -- the derived type range.
13693
13694 else
13695 Set_Etype (Rng, Implicit_Base);
13696 Set_Analyzed (Rng, True);
13697 end if;
13698 end Convert_Scalar_Bounds;
13699
13700 -------------------
13701 -- Copy_And_Swap --
13702 -------------------
13703
13704 procedure Copy_And_Swap (Priv, Full : Entity_Id) is
13705 begin
13706 -- Initialize new full declaration entity by copying the pertinent
13707 -- fields of the corresponding private declaration entity.
13708
13709 -- We temporarily set Ekind to a value appropriate for a type to
13710 -- avoid assert failures in Einfo from checking for setting type
13711 -- attributes on something that is not a type. Ekind (Priv) is an
13712 -- appropriate choice, since it allowed the attributes to be set
13713 -- in the first place. This Ekind value will be modified later.
13714
13715 Set_Ekind (Full, Ekind (Priv));
13716
13717 -- Also set Etype temporarily to Any_Type, again, in the absence
13718 -- of errors, it will be properly reset, and if there are errors,
13719 -- then we want a value of Any_Type to remain.
13720
13721 Set_Etype (Full, Any_Type);
13722
13723 -- Now start copying attributes
13724
13725 Set_Has_Discriminants (Full, Has_Discriminants (Priv));
13726
13727 if Has_Discriminants (Full) then
13728 Set_Discriminant_Constraint (Full, Discriminant_Constraint (Priv));
13729 Set_Stored_Constraint (Full, Stored_Constraint (Priv));
13730 end if;
13731
13732 Set_First_Rep_Item (Full, First_Rep_Item (Priv));
13733 Set_Homonym (Full, Homonym (Priv));
13734 Set_Is_Immediately_Visible (Full, Is_Immediately_Visible (Priv));
13735 Set_Is_Public (Full, Is_Public (Priv));
13736 Set_Is_Pure (Full, Is_Pure (Priv));
13737 Set_Is_Tagged_Type (Full, Is_Tagged_Type (Priv));
13738 Set_Has_Pragma_Unmodified (Full, Has_Pragma_Unmodified (Priv));
13739 Set_Has_Pragma_Unreferenced (Full, Has_Pragma_Unreferenced (Priv));
13740 Set_Has_Pragma_Unreferenced_Objects
13741 (Full, Has_Pragma_Unreferenced_Objects
13742 (Priv));
13743
13744 Conditional_Delay (Full, Priv);
13745
13746 if Is_Tagged_Type (Full) then
13747 Set_Direct_Primitive_Operations
13748 (Full, Direct_Primitive_Operations (Priv));
13749 Set_No_Tagged_Streams_Pragma
13750 (Full, No_Tagged_Streams_Pragma (Priv));
13751
13752 if Is_Base_Type (Priv) then
13753 Set_Class_Wide_Type (Full, Class_Wide_Type (Priv));
13754 end if;
13755 end if;
13756
13757 Set_Is_Volatile (Full, Is_Volatile (Priv));
13758 Set_Treat_As_Volatile (Full, Treat_As_Volatile (Priv));
13759 Set_Scope (Full, Scope (Priv));
13760 Set_Next_Entity (Full, Next_Entity (Priv));
13761 Set_First_Entity (Full, First_Entity (Priv));
13762 Set_Last_Entity (Full, Last_Entity (Priv));
13763
13764 -- If access types have been recorded for later handling, keep them in
13765 -- the full view so that they get handled when the full view freeze
13766 -- node is expanded.
13767
13768 if Present (Freeze_Node (Priv))
13769 and then Present (Access_Types_To_Process (Freeze_Node (Priv)))
13770 then
13771 Ensure_Freeze_Node (Full);
13772 Set_Access_Types_To_Process
13773 (Freeze_Node (Full),
13774 Access_Types_To_Process (Freeze_Node (Priv)));
13775 end if;
13776
13777 -- Swap the two entities. Now Private is the full type entity and Full
13778 -- is the private one. They will be swapped back at the end of the
13779 -- private part. This swapping ensures that the entity that is visible
13780 -- in the private part is the full declaration.
13781
13782 Exchange_Entities (Priv, Full);
13783 Append_Entity (Full, Scope (Full));
13784 end Copy_And_Swap;
13785
13786 -------------------------------------
13787 -- Copy_Array_Base_Type_Attributes --
13788 -------------------------------------
13789
13790 procedure Copy_Array_Base_Type_Attributes (T1, T2 : Entity_Id) is
13791 begin
13792 Set_Component_Alignment (T1, Component_Alignment (T2));
13793 Set_Component_Type (T1, Component_Type (T2));
13794 Set_Component_Size (T1, Component_Size (T2));
13795 Set_Has_Controlled_Component (T1, Has_Controlled_Component (T2));
13796 Set_Has_Non_Standard_Rep (T1, Has_Non_Standard_Rep (T2));
13797 Propagate_Concurrent_Flags (T1, T2);
13798 Set_Is_Packed (T1, Is_Packed (T2));
13799 Set_Has_Aliased_Components (T1, Has_Aliased_Components (T2));
13800 Set_Has_Atomic_Components (T1, Has_Atomic_Components (T2));
13801 Set_Has_Volatile_Components (T1, Has_Volatile_Components (T2));
13802 end Copy_Array_Base_Type_Attributes;
13803
13804 -----------------------------------
13805 -- Copy_Array_Subtype_Attributes --
13806 -----------------------------------
13807
13808 procedure Copy_Array_Subtype_Attributes (T1, T2 : Entity_Id) is
13809 begin
13810 Set_Size_Info (T1, T2);
13811
13812 Set_First_Index (T1, First_Index (T2));
13813 Set_Is_Aliased (T1, Is_Aliased (T2));
13814 Set_Is_Volatile (T1, Is_Volatile (T2));
13815 Set_Treat_As_Volatile (T1, Treat_As_Volatile (T2));
13816 Set_Is_Constrained (T1, Is_Constrained (T2));
13817 Set_Depends_On_Private (T1, Has_Private_Component (T2));
13818 Inherit_Rep_Item_Chain (T1, T2);
13819 Set_Convention (T1, Convention (T2));
13820 Set_Is_Limited_Composite (T1, Is_Limited_Composite (T2));
13821 Set_Is_Private_Composite (T1, Is_Private_Composite (T2));
13822 Set_Packed_Array_Impl_Type (T1, Packed_Array_Impl_Type (T2));
13823 end Copy_Array_Subtype_Attributes;
13824
13825 -----------------------------------
13826 -- Create_Constrained_Components --
13827 -----------------------------------
13828
13829 procedure Create_Constrained_Components
13830 (Subt : Entity_Id;
13831 Decl_Node : Node_Id;
13832 Typ : Entity_Id;
13833 Constraints : Elist_Id)
13834 is
13835 Loc : constant Source_Ptr := Sloc (Subt);
13836 Comp_List : constant Elist_Id := New_Elmt_List;
13837 Parent_Type : constant Entity_Id := Etype (Typ);
13838 Assoc_List : constant List_Id := New_List;
13839 Discr_Val : Elmt_Id;
13840 Errors : Boolean;
13841 New_C : Entity_Id;
13842 Old_C : Entity_Id;
13843 Is_Static : Boolean := True;
13844
13845 procedure Collect_Fixed_Components (Typ : Entity_Id);
13846 -- Collect parent type components that do not appear in a variant part
13847
13848 procedure Create_All_Components;
13849 -- Iterate over Comp_List to create the components of the subtype
13850
13851 function Create_Component (Old_Compon : Entity_Id) return Entity_Id;
13852 -- Creates a new component from Old_Compon, copying all the fields from
13853 -- it, including its Etype, inserts the new component in the Subt entity
13854 -- chain and returns the new component.
13855
13856 function Is_Variant_Record (T : Entity_Id) return Boolean;
13857 -- If true, and discriminants are static, collect only components from
13858 -- variants selected by discriminant values.
13859
13860 ------------------------------
13861 -- Collect_Fixed_Components --
13862 ------------------------------
13863
13864 procedure Collect_Fixed_Components (Typ : Entity_Id) is
13865 begin
13866 -- Build association list for discriminants, and find components of the
13867 -- variant part selected by the values of the discriminants.
13868
13869 Old_C := First_Discriminant (Typ);
13870 Discr_Val := First_Elmt (Constraints);
13871 while Present (Old_C) loop
13872 Append_To (Assoc_List,
13873 Make_Component_Association (Loc,
13874 Choices => New_List (New_Occurrence_Of (Old_C, Loc)),
13875 Expression => New_Copy (Node (Discr_Val))));
13876
13877 Next_Elmt (Discr_Val);
13878 Next_Discriminant (Old_C);
13879 end loop;
13880
13881 -- The tag and the possible parent component are unconditionally in
13882 -- the subtype.
13883
13884 if Is_Tagged_Type (Typ) or else Has_Controlled_Component (Typ) then
13885 Old_C := First_Component (Typ);
13886 while Present (Old_C) loop
13887 if Nam_In (Chars (Old_C), Name_uTag, Name_uParent) then
13888 Append_Elmt (Old_C, Comp_List);
13889 end if;
13890
13891 Next_Component (Old_C);
13892 end loop;
13893 end if;
13894 end Collect_Fixed_Components;
13895
13896 ---------------------------
13897 -- Create_All_Components --
13898 ---------------------------
13899
13900 procedure Create_All_Components is
13901 Comp : Elmt_Id;
13902
13903 begin
13904 Comp := First_Elmt (Comp_List);
13905 while Present (Comp) loop
13906 Old_C := Node (Comp);
13907 New_C := Create_Component (Old_C);
13908
13909 Set_Etype
13910 (New_C,
13911 Constrain_Component_Type
13912 (Old_C, Subt, Decl_Node, Typ, Constraints));
13913 Set_Is_Public (New_C, Is_Public (Subt));
13914
13915 Next_Elmt (Comp);
13916 end loop;
13917 end Create_All_Components;
13918
13919 ----------------------
13920 -- Create_Component --
13921 ----------------------
13922
13923 function Create_Component (Old_Compon : Entity_Id) return Entity_Id is
13924 New_Compon : constant Entity_Id := New_Copy (Old_Compon);
13925
13926 begin
13927 if Ekind (Old_Compon) = E_Discriminant
13928 and then Is_Completely_Hidden (Old_Compon)
13929 then
13930 -- This is a shadow discriminant created for a discriminant of
13931 -- the parent type, which needs to be present in the subtype.
13932 -- Give the shadow discriminant an internal name that cannot
13933 -- conflict with that of visible components.
13934
13935 Set_Chars (New_Compon, New_Internal_Name ('C'));
13936 end if;
13937
13938 -- Set the parent so we have a proper link for freezing etc. This is
13939 -- not a real parent pointer, since of course our parent does not own
13940 -- up to us and reference us, we are an illegitimate child of the
13941 -- original parent.
13942
13943 Set_Parent (New_Compon, Parent (Old_Compon));
13944
13945 -- If the old component's Esize was already determined and is a
13946 -- static value, then the new component simply inherits it. Otherwise
13947 -- the old component's size may require run-time determination, but
13948 -- the new component's size still might be statically determinable
13949 -- (if, for example it has a static constraint). In that case we want
13950 -- Layout_Type to recompute the component's size, so we reset its
13951 -- size and positional fields.
13952
13953 if Frontend_Layout_On_Target
13954 and then not Known_Static_Esize (Old_Compon)
13955 then
13956 Set_Esize (New_Compon, Uint_0);
13957 Init_Normalized_First_Bit (New_Compon);
13958 Init_Normalized_Position (New_Compon);
13959 Init_Normalized_Position_Max (New_Compon);
13960 end if;
13961
13962 -- We do not want this node marked as Comes_From_Source, since
13963 -- otherwise it would get first class status and a separate cross-
13964 -- reference line would be generated. Illegitimate children do not
13965 -- rate such recognition.
13966
13967 Set_Comes_From_Source (New_Compon, False);
13968
13969 -- But it is a real entity, and a birth certificate must be properly
13970 -- registered by entering it into the entity list.
13971
13972 Enter_Name (New_Compon);
13973
13974 return New_Compon;
13975 end Create_Component;
13976
13977 -----------------------
13978 -- Is_Variant_Record --
13979 -----------------------
13980
13981 function Is_Variant_Record (T : Entity_Id) return Boolean is
13982 begin
13983 return Nkind (Parent (T)) = N_Full_Type_Declaration
13984 and then Nkind (Type_Definition (Parent (T))) = N_Record_Definition
13985 and then Present (Component_List (Type_Definition (Parent (T))))
13986 and then
13987 Present
13988 (Variant_Part (Component_List (Type_Definition (Parent (T)))));
13989 end Is_Variant_Record;
13990
13991 -- Start of processing for Create_Constrained_Components
13992
13993 begin
13994 pragma Assert (Subt /= Base_Type (Subt));
13995 pragma Assert (Typ = Base_Type (Typ));
13996
13997 Set_First_Entity (Subt, Empty);
13998 Set_Last_Entity (Subt, Empty);
13999
14000 -- Check whether constraint is fully static, in which case we can
14001 -- optimize the list of components.
14002
14003 Discr_Val := First_Elmt (Constraints);
14004 while Present (Discr_Val) loop
14005 if not Is_OK_Static_Expression (Node (Discr_Val)) then
14006 Is_Static := False;
14007 exit;
14008 end if;
14009
14010 Next_Elmt (Discr_Val);
14011 end loop;
14012
14013 Set_Has_Static_Discriminants (Subt, Is_Static);
14014
14015 Push_Scope (Subt);
14016
14017 -- Inherit the discriminants of the parent type
14018
14019 Add_Discriminants : declare
14020 Num_Disc : Nat;
14021 Num_Gird : Nat;
14022
14023 begin
14024 Num_Disc := 0;
14025 Old_C := First_Discriminant (Typ);
14026
14027 while Present (Old_C) loop
14028 Num_Disc := Num_Disc + 1;
14029 New_C := Create_Component (Old_C);
14030 Set_Is_Public (New_C, Is_Public (Subt));
14031 Next_Discriminant (Old_C);
14032 end loop;
14033
14034 -- For an untagged derived subtype, the number of discriminants may
14035 -- be smaller than the number of inherited discriminants, because
14036 -- several of them may be renamed by a single new discriminant or
14037 -- constrained. In this case, add the hidden discriminants back into
14038 -- the subtype, because they need to be present if the optimizer of
14039 -- the GCC 4.x back-end decides to break apart assignments between
14040 -- objects using the parent view into member-wise assignments.
14041
14042 Num_Gird := 0;
14043
14044 if Is_Derived_Type (Typ)
14045 and then not Is_Tagged_Type (Typ)
14046 then
14047 Old_C := First_Stored_Discriminant (Typ);
14048
14049 while Present (Old_C) loop
14050 Num_Gird := Num_Gird + 1;
14051 Next_Stored_Discriminant (Old_C);
14052 end loop;
14053 end if;
14054
14055 if Num_Gird > Num_Disc then
14056
14057 -- Find out multiple uses of new discriminants, and add hidden
14058 -- components for the extra renamed discriminants. We recognize
14059 -- multiple uses through the Corresponding_Discriminant of a
14060 -- new discriminant: if it constrains several old discriminants,
14061 -- this field points to the last one in the parent type. The
14062 -- stored discriminants of the derived type have the same name
14063 -- as those of the parent.
14064
14065 declare
14066 Constr : Elmt_Id;
14067 New_Discr : Entity_Id;
14068 Old_Discr : Entity_Id;
14069
14070 begin
14071 Constr := First_Elmt (Stored_Constraint (Typ));
14072 Old_Discr := First_Stored_Discriminant (Typ);
14073 while Present (Constr) loop
14074 if Is_Entity_Name (Node (Constr))
14075 and then Ekind (Entity (Node (Constr))) = E_Discriminant
14076 then
14077 New_Discr := Entity (Node (Constr));
14078
14079 if Chars (Corresponding_Discriminant (New_Discr)) /=
14080 Chars (Old_Discr)
14081 then
14082 -- The new discriminant has been used to rename a
14083 -- subsequent old discriminant. Introduce a shadow
14084 -- component for the current old discriminant.
14085
14086 New_C := Create_Component (Old_Discr);
14087 Set_Original_Record_Component (New_C, Old_Discr);
14088 end if;
14089
14090 else
14091 -- The constraint has eliminated the old discriminant.
14092 -- Introduce a shadow component.
14093
14094 New_C := Create_Component (Old_Discr);
14095 Set_Original_Record_Component (New_C, Old_Discr);
14096 end if;
14097
14098 Next_Elmt (Constr);
14099 Next_Stored_Discriminant (Old_Discr);
14100 end loop;
14101 end;
14102 end if;
14103 end Add_Discriminants;
14104
14105 if Is_Static
14106 and then Is_Variant_Record (Typ)
14107 then
14108 Collect_Fixed_Components (Typ);
14109
14110 Gather_Components (
14111 Typ,
14112 Component_List (Type_Definition (Parent (Typ))),
14113 Governed_By => Assoc_List,
14114 Into => Comp_List,
14115 Report_Errors => Errors);
14116 pragma Assert (not Errors);
14117
14118 Create_All_Components;
14119
14120 -- If the subtype declaration is created for a tagged type derivation
14121 -- with constraints, we retrieve the record definition of the parent
14122 -- type to select the components of the proper variant.
14123
14124 elsif Is_Static
14125 and then Is_Tagged_Type (Typ)
14126 and then Nkind (Parent (Typ)) = N_Full_Type_Declaration
14127 and then
14128 Nkind (Type_Definition (Parent (Typ))) = N_Derived_Type_Definition
14129 and then Is_Variant_Record (Parent_Type)
14130 then
14131 Collect_Fixed_Components (Typ);
14132
14133 Gather_Components
14134 (Typ,
14135 Component_List (Type_Definition (Parent (Parent_Type))),
14136 Governed_By => Assoc_List,
14137 Into => Comp_List,
14138 Report_Errors => Errors);
14139
14140 -- Note: previously there was a check at this point that no errors
14141 -- were detected. As a consequence of AI05-220 there may be an error
14142 -- if an inherited discriminant that controls a variant has a non-
14143 -- static constraint.
14144
14145 -- If the tagged derivation has a type extension, collect all the
14146 -- new components therein.
14147
14148 if Present (Record_Extension_Part (Type_Definition (Parent (Typ))))
14149 then
14150 Old_C := First_Component (Typ);
14151 while Present (Old_C) loop
14152 if Original_Record_Component (Old_C) = Old_C
14153 and then Chars (Old_C) /= Name_uTag
14154 and then Chars (Old_C) /= Name_uParent
14155 then
14156 Append_Elmt (Old_C, Comp_List);
14157 end if;
14158
14159 Next_Component (Old_C);
14160 end loop;
14161 end if;
14162
14163 Create_All_Components;
14164
14165 else
14166 -- If discriminants are not static, or if this is a multi-level type
14167 -- extension, we have to include all components of the parent type.
14168
14169 Old_C := First_Component (Typ);
14170 while Present (Old_C) loop
14171 New_C := Create_Component (Old_C);
14172
14173 Set_Etype
14174 (New_C,
14175 Constrain_Component_Type
14176 (Old_C, Subt, Decl_Node, Typ, Constraints));
14177 Set_Is_Public (New_C, Is_Public (Subt));
14178
14179 Next_Component (Old_C);
14180 end loop;
14181 end if;
14182
14183 End_Scope;
14184 end Create_Constrained_Components;
14185
14186 ------------------------------------------
14187 -- Decimal_Fixed_Point_Type_Declaration --
14188 ------------------------------------------
14189
14190 procedure Decimal_Fixed_Point_Type_Declaration
14191 (T : Entity_Id;
14192 Def : Node_Id)
14193 is
14194 Loc : constant Source_Ptr := Sloc (Def);
14195 Digs_Expr : constant Node_Id := Digits_Expression (Def);
14196 Delta_Expr : constant Node_Id := Delta_Expression (Def);
14197 Implicit_Base : Entity_Id;
14198 Digs_Val : Uint;
14199 Delta_Val : Ureal;
14200 Scale_Val : Uint;
14201 Bound_Val : Ureal;
14202
14203 begin
14204 Check_SPARK_05_Restriction
14205 ("decimal fixed point type is not allowed", Def);
14206 Check_Restriction (No_Fixed_Point, Def);
14207
14208 -- Create implicit base type
14209
14210 Implicit_Base :=
14211 Create_Itype (E_Decimal_Fixed_Point_Type, Parent (Def), T, 'B');
14212 Set_Etype (Implicit_Base, Implicit_Base);
14213
14214 -- Analyze and process delta expression
14215
14216 Analyze_And_Resolve (Delta_Expr, Universal_Real);
14217
14218 Check_Delta_Expression (Delta_Expr);
14219 Delta_Val := Expr_Value_R (Delta_Expr);
14220
14221 -- Check delta is power of 10, and determine scale value from it
14222
14223 declare
14224 Val : Ureal;
14225
14226 begin
14227 Scale_Val := Uint_0;
14228 Val := Delta_Val;
14229
14230 if Val < Ureal_1 then
14231 while Val < Ureal_1 loop
14232 Val := Val * Ureal_10;
14233 Scale_Val := Scale_Val + 1;
14234 end loop;
14235
14236 if Scale_Val > 18 then
14237 Error_Msg_N ("scale exceeds maximum value of 18", Def);
14238 Scale_Val := UI_From_Int (+18);
14239 end if;
14240
14241 else
14242 while Val > Ureal_1 loop
14243 Val := Val / Ureal_10;
14244 Scale_Val := Scale_Val - 1;
14245 end loop;
14246
14247 if Scale_Val < -18 then
14248 Error_Msg_N ("scale is less than minimum value of -18", Def);
14249 Scale_Val := UI_From_Int (-18);
14250 end if;
14251 end if;
14252
14253 if Val /= Ureal_1 then
14254 Error_Msg_N ("delta expression must be a power of 10", Def);
14255 Delta_Val := Ureal_10 ** (-Scale_Val);
14256 end if;
14257 end;
14258
14259 -- Set delta, scale and small (small = delta for decimal type)
14260
14261 Set_Delta_Value (Implicit_Base, Delta_Val);
14262 Set_Scale_Value (Implicit_Base, Scale_Val);
14263 Set_Small_Value (Implicit_Base, Delta_Val);
14264
14265 -- Analyze and process digits expression
14266
14267 Analyze_And_Resolve (Digs_Expr, Any_Integer);
14268 Check_Digits_Expression (Digs_Expr);
14269 Digs_Val := Expr_Value (Digs_Expr);
14270
14271 if Digs_Val > 18 then
14272 Digs_Val := UI_From_Int (+18);
14273 Error_Msg_N ("digits value out of range, maximum is 18", Digs_Expr);
14274 end if;
14275
14276 Set_Digits_Value (Implicit_Base, Digs_Val);
14277 Bound_Val := UR_From_Uint (10 ** Digs_Val - 1) * Delta_Val;
14278
14279 -- Set range of base type from digits value for now. This will be
14280 -- expanded to represent the true underlying base range by Freeze.
14281
14282 Set_Fixed_Range (Implicit_Base, Loc, -Bound_Val, Bound_Val);
14283
14284 -- Note: We leave size as zero for now, size will be set at freeze
14285 -- time. We have to do this for ordinary fixed-point, because the size
14286 -- depends on the specified small, and we might as well do the same for
14287 -- decimal fixed-point.
14288
14289 pragma Assert (Esize (Implicit_Base) = Uint_0);
14290
14291 -- If there are bounds given in the declaration use them as the
14292 -- bounds of the first named subtype.
14293
14294 if Present (Real_Range_Specification (Def)) then
14295 declare
14296 RRS : constant Node_Id := Real_Range_Specification (Def);
14297 Low : constant Node_Id := Low_Bound (RRS);
14298 High : constant Node_Id := High_Bound (RRS);
14299 Low_Val : Ureal;
14300 High_Val : Ureal;
14301
14302 begin
14303 Analyze_And_Resolve (Low, Any_Real);
14304 Analyze_And_Resolve (High, Any_Real);
14305 Check_Real_Bound (Low);
14306 Check_Real_Bound (High);
14307 Low_Val := Expr_Value_R (Low);
14308 High_Val := Expr_Value_R (High);
14309
14310 if Low_Val < (-Bound_Val) then
14311 Error_Msg_N
14312 ("range low bound too small for digits value", Low);
14313 Low_Val := -Bound_Val;
14314 end if;
14315
14316 if High_Val > Bound_Val then
14317 Error_Msg_N
14318 ("range high bound too large for digits value", High);
14319 High_Val := Bound_Val;
14320 end if;
14321
14322 Set_Fixed_Range (T, Loc, Low_Val, High_Val);
14323 end;
14324
14325 -- If no explicit range, use range that corresponds to given
14326 -- digits value. This will end up as the final range for the
14327 -- first subtype.
14328
14329 else
14330 Set_Fixed_Range (T, Loc, -Bound_Val, Bound_Val);
14331 end if;
14332
14333 -- Complete entity for first subtype. The inheritance of the rep item
14334 -- chain ensures that SPARK-related pragmas are not clobbered when the
14335 -- decimal fixed point type acts as a full view of a private type.
14336
14337 Set_Ekind (T, E_Decimal_Fixed_Point_Subtype);
14338 Set_Etype (T, Implicit_Base);
14339 Set_Size_Info (T, Implicit_Base);
14340 Inherit_Rep_Item_Chain (T, Implicit_Base);
14341 Set_Digits_Value (T, Digs_Val);
14342 Set_Delta_Value (T, Delta_Val);
14343 Set_Small_Value (T, Delta_Val);
14344 Set_Scale_Value (T, Scale_Val);
14345 Set_Is_Constrained (T);
14346 end Decimal_Fixed_Point_Type_Declaration;
14347
14348 -----------------------------------
14349 -- Derive_Progenitor_Subprograms --
14350 -----------------------------------
14351
14352 procedure Derive_Progenitor_Subprograms
14353 (Parent_Type : Entity_Id;
14354 Tagged_Type : Entity_Id)
14355 is
14356 E : Entity_Id;
14357 Elmt : Elmt_Id;
14358 Iface : Entity_Id;
14359 Iface_Elmt : Elmt_Id;
14360 Iface_Subp : Entity_Id;
14361 New_Subp : Entity_Id := Empty;
14362 Prim_Elmt : Elmt_Id;
14363 Subp : Entity_Id;
14364 Typ : Entity_Id;
14365
14366 begin
14367 pragma Assert (Ada_Version >= Ada_2005
14368 and then Is_Record_Type (Tagged_Type)
14369 and then Is_Tagged_Type (Tagged_Type)
14370 and then Has_Interfaces (Tagged_Type));
14371
14372 -- Step 1: Transfer to the full-view primitives associated with the
14373 -- partial-view that cover interface primitives. Conceptually this
14374 -- work should be done later by Process_Full_View; done here to
14375 -- simplify its implementation at later stages. It can be safely
14376 -- done here because interfaces must be visible in the partial and
14377 -- private view (RM 7.3(7.3/2)).
14378
14379 -- Small optimization: This work is only required if the parent may
14380 -- have entities whose Alias attribute reference an interface primitive.
14381 -- Such a situation may occur if the parent is an abstract type and the
14382 -- primitive has not been yet overridden or if the parent is a generic
14383 -- formal type covering interfaces.
14384
14385 -- If the tagged type is not abstract, it cannot have abstract
14386 -- primitives (the only entities in the list of primitives of
14387 -- non-abstract tagged types that can reference abstract primitives
14388 -- through its Alias attribute are the internal entities that have
14389 -- attribute Interface_Alias, and these entities are generated later
14390 -- by Add_Internal_Interface_Entities).
14391
14392 if In_Private_Part (Current_Scope)
14393 and then (Is_Abstract_Type (Parent_Type)
14394 or else
14395 Is_Generic_Type (Parent_Type))
14396 then
14397 Elmt := First_Elmt (Primitive_Operations (Tagged_Type));
14398 while Present (Elmt) loop
14399 Subp := Node (Elmt);
14400
14401 -- At this stage it is not possible to have entities in the list
14402 -- of primitives that have attribute Interface_Alias.
14403
14404 pragma Assert (No (Interface_Alias (Subp)));
14405
14406 Typ := Find_Dispatching_Type (Ultimate_Alias (Subp));
14407
14408 if Is_Interface (Typ) then
14409 E := Find_Primitive_Covering_Interface
14410 (Tagged_Type => Tagged_Type,
14411 Iface_Prim => Subp);
14412
14413 if Present (E)
14414 and then Find_Dispatching_Type (Ultimate_Alias (E)) /= Typ
14415 then
14416 Replace_Elmt (Elmt, E);
14417 Remove_Homonym (Subp);
14418 end if;
14419 end if;
14420
14421 Next_Elmt (Elmt);
14422 end loop;
14423 end if;
14424
14425 -- Step 2: Add primitives of progenitors that are not implemented by
14426 -- parents of Tagged_Type.
14427
14428 if Present (Interfaces (Base_Type (Tagged_Type))) then
14429 Iface_Elmt := First_Elmt (Interfaces (Base_Type (Tagged_Type)));
14430 while Present (Iface_Elmt) loop
14431 Iface := Node (Iface_Elmt);
14432
14433 Prim_Elmt := First_Elmt (Primitive_Operations (Iface));
14434 while Present (Prim_Elmt) loop
14435 Iface_Subp := Node (Prim_Elmt);
14436
14437 -- Exclude derivation of predefined primitives except those
14438 -- that come from source, or are inherited from one that comes
14439 -- from source. Required to catch declarations of equality
14440 -- operators of interfaces. For example:
14441
14442 -- type Iface is interface;
14443 -- function "=" (Left, Right : Iface) return Boolean;
14444
14445 if not Is_Predefined_Dispatching_Operation (Iface_Subp)
14446 or else Comes_From_Source (Ultimate_Alias (Iface_Subp))
14447 then
14448 E := Find_Primitive_Covering_Interface
14449 (Tagged_Type => Tagged_Type,
14450 Iface_Prim => Iface_Subp);
14451
14452 -- If not found we derive a new primitive leaving its alias
14453 -- attribute referencing the interface primitive.
14454
14455 if No (E) then
14456 Derive_Subprogram
14457 (New_Subp, Iface_Subp, Tagged_Type, Iface);
14458
14459 -- Ada 2012 (AI05-0197): If the covering primitive's name
14460 -- differs from the name of the interface primitive then it
14461 -- is a private primitive inherited from a parent type. In
14462 -- such case, given that Tagged_Type covers the interface,
14463 -- the inherited private primitive becomes visible. For such
14464 -- purpose we add a new entity that renames the inherited
14465 -- private primitive.
14466
14467 elsif Chars (E) /= Chars (Iface_Subp) then
14468 pragma Assert (Has_Suffix (E, 'P'));
14469 Derive_Subprogram
14470 (New_Subp, Iface_Subp, Tagged_Type, Iface);
14471 Set_Alias (New_Subp, E);
14472 Set_Is_Abstract_Subprogram (New_Subp,
14473 Is_Abstract_Subprogram (E));
14474
14475 -- Propagate to the full view interface entities associated
14476 -- with the partial view.
14477
14478 elsif In_Private_Part (Current_Scope)
14479 and then Present (Alias (E))
14480 and then Alias (E) = Iface_Subp
14481 and then
14482 List_Containing (Parent (E)) /=
14483 Private_Declarations
14484 (Specification
14485 (Unit_Declaration_Node (Current_Scope)))
14486 then
14487 Append_Elmt (E, Primitive_Operations (Tagged_Type));
14488 end if;
14489 end if;
14490
14491 Next_Elmt (Prim_Elmt);
14492 end loop;
14493
14494 Next_Elmt (Iface_Elmt);
14495 end loop;
14496 end if;
14497 end Derive_Progenitor_Subprograms;
14498
14499 -----------------------
14500 -- Derive_Subprogram --
14501 -----------------------
14502
14503 procedure Derive_Subprogram
14504 (New_Subp : out Entity_Id;
14505 Parent_Subp : Entity_Id;
14506 Derived_Type : Entity_Id;
14507 Parent_Type : Entity_Id;
14508 Actual_Subp : Entity_Id := Empty)
14509 is
14510 Formal : Entity_Id;
14511 -- Formal parameter of parent primitive operation
14512
14513 Formal_Of_Actual : Entity_Id;
14514 -- Formal parameter of actual operation, when the derivation is to
14515 -- create a renaming for a primitive operation of an actual in an
14516 -- instantiation.
14517
14518 New_Formal : Entity_Id;
14519 -- Formal of inherited operation
14520
14521 Visible_Subp : Entity_Id := Parent_Subp;
14522
14523 function Is_Private_Overriding return Boolean;
14524 -- If Subp is a private overriding of a visible operation, the inherited
14525 -- operation derives from the overridden op (even though its body is the
14526 -- overriding one) and the inherited operation is visible now. See
14527 -- sem_disp to see the full details of the handling of the overridden
14528 -- subprogram, which is removed from the list of primitive operations of
14529 -- the type. The overridden subprogram is saved locally in Visible_Subp,
14530 -- and used to diagnose abstract operations that need overriding in the
14531 -- derived type.
14532
14533 procedure Replace_Type (Id, New_Id : Entity_Id);
14534 -- When the type is an anonymous access type, create a new access type
14535 -- designating the derived type.
14536
14537 procedure Set_Derived_Name;
14538 -- This procedure sets the appropriate Chars name for New_Subp. This
14539 -- is normally just a copy of the parent name. An exception arises for
14540 -- type support subprograms, where the name is changed to reflect the
14541 -- name of the derived type, e.g. if type foo is derived from type bar,
14542 -- then a procedure barDA is derived with a name fooDA.
14543
14544 ---------------------------
14545 -- Is_Private_Overriding --
14546 ---------------------------
14547
14548 function Is_Private_Overriding return Boolean is
14549 Prev : Entity_Id;
14550
14551 begin
14552 -- If the parent is not a dispatching operation there is no
14553 -- need to investigate overridings
14554
14555 if not Is_Dispatching_Operation (Parent_Subp) then
14556 return False;
14557 end if;
14558
14559 -- The visible operation that is overridden is a homonym of the
14560 -- parent subprogram. We scan the homonym chain to find the one
14561 -- whose alias is the subprogram we are deriving.
14562
14563 Prev := Current_Entity (Parent_Subp);
14564 while Present (Prev) loop
14565 if Ekind (Prev) = Ekind (Parent_Subp)
14566 and then Alias (Prev) = Parent_Subp
14567 and then Scope (Parent_Subp) = Scope (Prev)
14568 and then not Is_Hidden (Prev)
14569 then
14570 Visible_Subp := Prev;
14571 return True;
14572 end if;
14573
14574 Prev := Homonym (Prev);
14575 end loop;
14576
14577 return False;
14578 end Is_Private_Overriding;
14579
14580 ------------------
14581 -- Replace_Type --
14582 ------------------
14583
14584 procedure Replace_Type (Id, New_Id : Entity_Id) is
14585 Id_Type : constant Entity_Id := Etype (Id);
14586 Acc_Type : Entity_Id;
14587 Par : constant Node_Id := Parent (Derived_Type);
14588
14589 begin
14590 -- When the type is an anonymous access type, create a new access
14591 -- type designating the derived type. This itype must be elaborated
14592 -- at the point of the derivation, not on subsequent calls that may
14593 -- be out of the proper scope for Gigi, so we insert a reference to
14594 -- it after the derivation.
14595
14596 if Ekind (Id_Type) = E_Anonymous_Access_Type then
14597 declare
14598 Desig_Typ : Entity_Id := Designated_Type (Id_Type);
14599
14600 begin
14601 if Ekind (Desig_Typ) = E_Record_Type_With_Private
14602 and then Present (Full_View (Desig_Typ))
14603 and then not Is_Private_Type (Parent_Type)
14604 then
14605 Desig_Typ := Full_View (Desig_Typ);
14606 end if;
14607
14608 if Base_Type (Desig_Typ) = Base_Type (Parent_Type)
14609
14610 -- Ada 2005 (AI-251): Handle also derivations of abstract
14611 -- interface primitives.
14612
14613 or else (Is_Interface (Desig_Typ)
14614 and then not Is_Class_Wide_Type (Desig_Typ))
14615 then
14616 Acc_Type := New_Copy (Id_Type);
14617 Set_Etype (Acc_Type, Acc_Type);
14618 Set_Scope (Acc_Type, New_Subp);
14619
14620 -- Set size of anonymous access type. If we have an access
14621 -- to an unconstrained array, this is a fat pointer, so it
14622 -- is sizes at twice addtress size.
14623
14624 if Is_Array_Type (Desig_Typ)
14625 and then not Is_Constrained (Desig_Typ)
14626 then
14627 Init_Size (Acc_Type, 2 * System_Address_Size);
14628
14629 -- Other cases use a thin pointer
14630
14631 else
14632 Init_Size (Acc_Type, System_Address_Size);
14633 end if;
14634
14635 -- Set remaining characterstics of anonymous access type
14636
14637 Init_Alignment (Acc_Type);
14638 Set_Directly_Designated_Type (Acc_Type, Derived_Type);
14639
14640 Set_Etype (New_Id, Acc_Type);
14641 Set_Scope (New_Id, New_Subp);
14642
14643 -- Create a reference to it
14644
14645 Build_Itype_Reference (Acc_Type, Parent (Derived_Type));
14646
14647 else
14648 Set_Etype (New_Id, Id_Type);
14649 end if;
14650 end;
14651
14652 -- In Ada2012, a formal may have an incomplete type but the type
14653 -- derivation that inherits the primitive follows the full view.
14654
14655 elsif Base_Type (Id_Type) = Base_Type (Parent_Type)
14656 or else
14657 (Ekind (Id_Type) = E_Record_Type_With_Private
14658 and then Present (Full_View (Id_Type))
14659 and then
14660 Base_Type (Full_View (Id_Type)) = Base_Type (Parent_Type))
14661 or else
14662 (Ada_Version >= Ada_2012
14663 and then Ekind (Id_Type) = E_Incomplete_Type
14664 and then Full_View (Id_Type) = Parent_Type)
14665 then
14666 -- Constraint checks on formals are generated during expansion,
14667 -- based on the signature of the original subprogram. The bounds
14668 -- of the derived type are not relevant, and thus we can use
14669 -- the base type for the formals. However, the return type may be
14670 -- used in a context that requires that the proper static bounds
14671 -- be used (a case statement, for example) and for those cases
14672 -- we must use the derived type (first subtype), not its base.
14673
14674 -- If the derived_type_definition has no constraints, we know that
14675 -- the derived type has the same constraints as the first subtype
14676 -- of the parent, and we can also use it rather than its base,
14677 -- which can lead to more efficient code.
14678
14679 if Etype (Id) = Parent_Type then
14680 if Is_Scalar_Type (Parent_Type)
14681 and then
14682 Subtypes_Statically_Compatible (Parent_Type, Derived_Type)
14683 then
14684 Set_Etype (New_Id, Derived_Type);
14685
14686 elsif Nkind (Par) = N_Full_Type_Declaration
14687 and then
14688 Nkind (Type_Definition (Par)) = N_Derived_Type_Definition
14689 and then
14690 Is_Entity_Name
14691 (Subtype_Indication (Type_Definition (Par)))
14692 then
14693 Set_Etype (New_Id, Derived_Type);
14694
14695 else
14696 Set_Etype (New_Id, Base_Type (Derived_Type));
14697 end if;
14698
14699 else
14700 Set_Etype (New_Id, Base_Type (Derived_Type));
14701 end if;
14702
14703 else
14704 Set_Etype (New_Id, Etype (Id));
14705 end if;
14706 end Replace_Type;
14707
14708 ----------------------
14709 -- Set_Derived_Name --
14710 ----------------------
14711
14712 procedure Set_Derived_Name is
14713 Nm : constant TSS_Name_Type := Get_TSS_Name (Parent_Subp);
14714 begin
14715 if Nm = TSS_Null then
14716 Set_Chars (New_Subp, Chars (Parent_Subp));
14717 else
14718 Set_Chars (New_Subp, Make_TSS_Name (Base_Type (Derived_Type), Nm));
14719 end if;
14720 end Set_Derived_Name;
14721
14722 -- Start of processing for Derive_Subprogram
14723
14724 begin
14725 New_Subp := New_Entity (Nkind (Parent_Subp), Sloc (Derived_Type));
14726 Set_Ekind (New_Subp, Ekind (Parent_Subp));
14727
14728 -- Check whether the inherited subprogram is a private operation that
14729 -- should be inherited but not yet made visible. Such subprograms can
14730 -- become visible at a later point (e.g., the private part of a public
14731 -- child unit) via Declare_Inherited_Private_Subprograms. If the
14732 -- following predicate is true, then this is not such a private
14733 -- operation and the subprogram simply inherits the name of the parent
14734 -- subprogram. Note the special check for the names of controlled
14735 -- operations, which are currently exempted from being inherited with
14736 -- a hidden name because they must be findable for generation of
14737 -- implicit run-time calls.
14738
14739 if not Is_Hidden (Parent_Subp)
14740 or else Is_Internal (Parent_Subp)
14741 or else Is_Private_Overriding
14742 or else Is_Internal_Name (Chars (Parent_Subp))
14743 or else Nam_In (Chars (Parent_Subp), Name_Initialize,
14744 Name_Adjust,
14745 Name_Finalize)
14746 then
14747 Set_Derived_Name;
14748
14749 -- An inherited dispatching equality will be overridden by an internally
14750 -- generated one, or by an explicit one, so preserve its name and thus
14751 -- its entry in the dispatch table. Otherwise, if Parent_Subp is a
14752 -- private operation it may become invisible if the full view has
14753 -- progenitors, and the dispatch table will be malformed.
14754 -- We check that the type is limited to handle the anomalous declaration
14755 -- of Limited_Controlled, which is derived from a non-limited type, and
14756 -- which is handled specially elsewhere as well.
14757
14758 elsif Chars (Parent_Subp) = Name_Op_Eq
14759 and then Is_Dispatching_Operation (Parent_Subp)
14760 and then Etype (Parent_Subp) = Standard_Boolean
14761 and then not Is_Limited_Type (Etype (First_Formal (Parent_Subp)))
14762 and then
14763 Etype (First_Formal (Parent_Subp)) =
14764 Etype (Next_Formal (First_Formal (Parent_Subp)))
14765 then
14766 Set_Derived_Name;
14767
14768 -- If parent is hidden, this can be a regular derivation if the
14769 -- parent is immediately visible in a non-instantiating context,
14770 -- or if we are in the private part of an instance. This test
14771 -- should still be refined ???
14772
14773 -- The test for In_Instance_Not_Visible avoids inheriting the derived
14774 -- operation as a non-visible operation in cases where the parent
14775 -- subprogram might not be visible now, but was visible within the
14776 -- original generic, so it would be wrong to make the inherited
14777 -- subprogram non-visible now. (Not clear if this test is fully
14778 -- correct; are there any cases where we should declare the inherited
14779 -- operation as not visible to avoid it being overridden, e.g., when
14780 -- the parent type is a generic actual with private primitives ???)
14781
14782 -- (they should be treated the same as other private inherited
14783 -- subprograms, but it's not clear how to do this cleanly). ???
14784
14785 elsif (In_Open_Scopes (Scope (Base_Type (Parent_Type)))
14786 and then Is_Immediately_Visible (Parent_Subp)
14787 and then not In_Instance)
14788 or else In_Instance_Not_Visible
14789 then
14790 Set_Derived_Name;
14791
14792 -- Ada 2005 (AI-251): Regular derivation if the parent subprogram
14793 -- overrides an interface primitive because interface primitives
14794 -- must be visible in the partial view of the parent (RM 7.3 (7.3/2))
14795
14796 elsif Ada_Version >= Ada_2005
14797 and then Is_Dispatching_Operation (Parent_Subp)
14798 and then Covers_Some_Interface (Parent_Subp)
14799 then
14800 Set_Derived_Name;
14801
14802 -- Otherwise, the type is inheriting a private operation, so enter it
14803 -- with a special name so it can't be overridden.
14804
14805 else
14806 Set_Chars (New_Subp, New_External_Name (Chars (Parent_Subp), 'P'));
14807 end if;
14808
14809 Set_Parent (New_Subp, Parent (Derived_Type));
14810
14811 if Present (Actual_Subp) then
14812 Replace_Type (Actual_Subp, New_Subp);
14813 else
14814 Replace_Type (Parent_Subp, New_Subp);
14815 end if;
14816
14817 Conditional_Delay (New_Subp, Parent_Subp);
14818
14819 -- If we are creating a renaming for a primitive operation of an
14820 -- actual of a generic derived type, we must examine the signature
14821 -- of the actual primitive, not that of the generic formal, which for
14822 -- example may be an interface. However the name and initial value
14823 -- of the inherited operation are those of the formal primitive.
14824
14825 Formal := First_Formal (Parent_Subp);
14826
14827 if Present (Actual_Subp) then
14828 Formal_Of_Actual := First_Formal (Actual_Subp);
14829 else
14830 Formal_Of_Actual := Empty;
14831 end if;
14832
14833 while Present (Formal) loop
14834 New_Formal := New_Copy (Formal);
14835
14836 -- Normally we do not go copying parents, but in the case of
14837 -- formals, we need to link up to the declaration (which is the
14838 -- parameter specification), and it is fine to link up to the
14839 -- original formal's parameter specification in this case.
14840
14841 Set_Parent (New_Formal, Parent (Formal));
14842 Append_Entity (New_Formal, New_Subp);
14843
14844 if Present (Formal_Of_Actual) then
14845 Replace_Type (Formal_Of_Actual, New_Formal);
14846 Next_Formal (Formal_Of_Actual);
14847 else
14848 Replace_Type (Formal, New_Formal);
14849 end if;
14850
14851 Next_Formal (Formal);
14852 end loop;
14853
14854 -- If this derivation corresponds to a tagged generic actual, then
14855 -- primitive operations rename those of the actual. Otherwise the
14856 -- primitive operations rename those of the parent type, If the parent
14857 -- renames an intrinsic operator, so does the new subprogram. We except
14858 -- concatenation, which is always properly typed, and does not get
14859 -- expanded as other intrinsic operations.
14860
14861 if No (Actual_Subp) then
14862 if Is_Intrinsic_Subprogram (Parent_Subp) then
14863 Set_Is_Intrinsic_Subprogram (New_Subp);
14864
14865 if Present (Alias (Parent_Subp))
14866 and then Chars (Parent_Subp) /= Name_Op_Concat
14867 then
14868 Set_Alias (New_Subp, Alias (Parent_Subp));
14869 else
14870 Set_Alias (New_Subp, Parent_Subp);
14871 end if;
14872
14873 else
14874 Set_Alias (New_Subp, Parent_Subp);
14875 end if;
14876
14877 else
14878 Set_Alias (New_Subp, Actual_Subp);
14879 end if;
14880
14881 -- Inherit the "ghostness" from the parent subprogram
14882
14883 if Is_Ghost_Entity (Alias (New_Subp)) then
14884 Set_Is_Ghost_Entity (New_Subp);
14885 end if;
14886
14887 -- Derived subprograms of a tagged type must inherit the convention
14888 -- of the parent subprogram (a requirement of AI-117). Derived
14889 -- subprograms of untagged types simply get convention Ada by default.
14890
14891 -- If the derived type is a tagged generic formal type with unknown
14892 -- discriminants, its convention is intrinsic (RM 6.3.1 (8)).
14893
14894 -- However, if the type is derived from a generic formal, the further
14895 -- inherited subprogram has the convention of the non-generic ancestor.
14896 -- Otherwise there would be no way to override the operation.
14897 -- (This is subject to forthcoming ARG discussions).
14898
14899 if Is_Tagged_Type (Derived_Type) then
14900 if Is_Generic_Type (Derived_Type)
14901 and then Has_Unknown_Discriminants (Derived_Type)
14902 then
14903 Set_Convention (New_Subp, Convention_Intrinsic);
14904
14905 else
14906 if Is_Generic_Type (Parent_Type)
14907 and then Has_Unknown_Discriminants (Parent_Type)
14908 then
14909 Set_Convention (New_Subp, Convention (Alias (Parent_Subp)));
14910 else
14911 Set_Convention (New_Subp, Convention (Parent_Subp));
14912 end if;
14913 end if;
14914 end if;
14915
14916 -- Predefined controlled operations retain their name even if the parent
14917 -- is hidden (see above), but they are not primitive operations if the
14918 -- ancestor is not visible, for example if the parent is a private
14919 -- extension completed with a controlled extension. Note that a full
14920 -- type that is controlled can break privacy: the flag Is_Controlled is
14921 -- set on both views of the type.
14922
14923 if Is_Controlled (Parent_Type)
14924 and then Nam_In (Chars (Parent_Subp), Name_Initialize,
14925 Name_Adjust,
14926 Name_Finalize)
14927 and then Is_Hidden (Parent_Subp)
14928 and then not Is_Visibly_Controlled (Parent_Type)
14929 then
14930 Set_Is_Hidden (New_Subp);
14931 end if;
14932
14933 Set_Is_Imported (New_Subp, Is_Imported (Parent_Subp));
14934 Set_Is_Exported (New_Subp, Is_Exported (Parent_Subp));
14935
14936 if Ekind (Parent_Subp) = E_Procedure then
14937 Set_Is_Valued_Procedure
14938 (New_Subp, Is_Valued_Procedure (Parent_Subp));
14939 else
14940 Set_Has_Controlling_Result
14941 (New_Subp, Has_Controlling_Result (Parent_Subp));
14942 end if;
14943
14944 -- No_Return must be inherited properly. If this is overridden in the
14945 -- case of a dispatching operation, then a check is made in Sem_Disp
14946 -- that the overriding operation is also No_Return (no such check is
14947 -- required for the case of non-dispatching operation.
14948
14949 Set_No_Return (New_Subp, No_Return (Parent_Subp));
14950
14951 -- A derived function with a controlling result is abstract. If the
14952 -- Derived_Type is a nonabstract formal generic derived type, then
14953 -- inherited operations are not abstract: the required check is done at
14954 -- instantiation time. If the derivation is for a generic actual, the
14955 -- function is not abstract unless the actual is.
14956
14957 if Is_Generic_Type (Derived_Type)
14958 and then not Is_Abstract_Type (Derived_Type)
14959 then
14960 null;
14961
14962 -- Ada 2005 (AI-228): Calculate the "require overriding" and "abstract"
14963 -- properties of the subprogram, as defined in RM-3.9.3(4/2-6/2).
14964
14965 -- A subprogram subject to pragma Extensions_Visible with value False
14966 -- requires overriding if the subprogram has at least one controlling
14967 -- OUT parameter (SPARK RM 6.1.7(6)).
14968
14969 elsif Ada_Version >= Ada_2005
14970 and then (Is_Abstract_Subprogram (Alias (New_Subp))
14971 or else (Is_Tagged_Type (Derived_Type)
14972 and then Etype (New_Subp) = Derived_Type
14973 and then not Is_Null_Extension (Derived_Type))
14974 or else (Is_Tagged_Type (Derived_Type)
14975 and then Ekind (Etype (New_Subp)) =
14976 E_Anonymous_Access_Type
14977 and then Designated_Type (Etype (New_Subp)) =
14978 Derived_Type
14979 and then not Is_Null_Extension (Derived_Type))
14980 or else (Comes_From_Source (Alias (New_Subp))
14981 and then Is_EVF_Procedure (Alias (New_Subp))))
14982 and then No (Actual_Subp)
14983 then
14984 if not Is_Tagged_Type (Derived_Type)
14985 or else Is_Abstract_Type (Derived_Type)
14986 or else Is_Abstract_Subprogram (Alias (New_Subp))
14987 then
14988 Set_Is_Abstract_Subprogram (New_Subp);
14989 else
14990 Set_Requires_Overriding (New_Subp);
14991 end if;
14992
14993 elsif Ada_Version < Ada_2005
14994 and then (Is_Abstract_Subprogram (Alias (New_Subp))
14995 or else (Is_Tagged_Type (Derived_Type)
14996 and then Etype (New_Subp) = Derived_Type
14997 and then No (Actual_Subp)))
14998 then
14999 Set_Is_Abstract_Subprogram (New_Subp);
15000
15001 -- AI05-0097 : an inherited operation that dispatches on result is
15002 -- abstract if the derived type is abstract, even if the parent type
15003 -- is concrete and the derived type is a null extension.
15004
15005 elsif Has_Controlling_Result (Alias (New_Subp))
15006 and then Is_Abstract_Type (Etype (New_Subp))
15007 then
15008 Set_Is_Abstract_Subprogram (New_Subp);
15009
15010 -- Finally, if the parent type is abstract we must verify that all
15011 -- inherited operations are either non-abstract or overridden, or that
15012 -- the derived type itself is abstract (this check is performed at the
15013 -- end of a package declaration, in Check_Abstract_Overriding). A
15014 -- private overriding in the parent type will not be visible in the
15015 -- derivation if we are not in an inner package or in a child unit of
15016 -- the parent type, in which case the abstractness of the inherited
15017 -- operation is carried to the new subprogram.
15018
15019 elsif Is_Abstract_Type (Parent_Type)
15020 and then not In_Open_Scopes (Scope (Parent_Type))
15021 and then Is_Private_Overriding
15022 and then Is_Abstract_Subprogram (Visible_Subp)
15023 then
15024 if No (Actual_Subp) then
15025 Set_Alias (New_Subp, Visible_Subp);
15026 Set_Is_Abstract_Subprogram (New_Subp, True);
15027
15028 else
15029 -- If this is a derivation for an instance of a formal derived
15030 -- type, abstractness comes from the primitive operation of the
15031 -- actual, not from the operation inherited from the ancestor.
15032
15033 Set_Is_Abstract_Subprogram
15034 (New_Subp, Is_Abstract_Subprogram (Actual_Subp));
15035 end if;
15036 end if;
15037
15038 New_Overloaded_Entity (New_Subp, Derived_Type);
15039
15040 -- Check for case of a derived subprogram for the instantiation of a
15041 -- formal derived tagged type, if so mark the subprogram as dispatching
15042 -- and inherit the dispatching attributes of the actual subprogram. The
15043 -- derived subprogram is effectively renaming of the actual subprogram,
15044 -- so it needs to have the same attributes as the actual.
15045
15046 if Present (Actual_Subp)
15047 and then Is_Dispatching_Operation (Actual_Subp)
15048 then
15049 Set_Is_Dispatching_Operation (New_Subp);
15050
15051 if Present (DTC_Entity (Actual_Subp)) then
15052 Set_DTC_Entity (New_Subp, DTC_Entity (Actual_Subp));
15053 Set_DT_Position_Value (New_Subp, DT_Position (Actual_Subp));
15054 end if;
15055 end if;
15056
15057 -- Indicate that a derived subprogram does not require a body and that
15058 -- it does not require processing of default expressions.
15059
15060 Set_Has_Completion (New_Subp);
15061 Set_Default_Expressions_Processed (New_Subp);
15062
15063 if Ekind (New_Subp) = E_Function then
15064 Set_Mechanism (New_Subp, Mechanism (Parent_Subp));
15065 end if;
15066 end Derive_Subprogram;
15067
15068 ------------------------
15069 -- Derive_Subprograms --
15070 ------------------------
15071
15072 procedure Derive_Subprograms
15073 (Parent_Type : Entity_Id;
15074 Derived_Type : Entity_Id;
15075 Generic_Actual : Entity_Id := Empty)
15076 is
15077 Op_List : constant Elist_Id :=
15078 Collect_Primitive_Operations (Parent_Type);
15079
15080 function Check_Derived_Type return Boolean;
15081 -- Check that all the entities derived from Parent_Type are found in
15082 -- the list of primitives of Derived_Type exactly in the same order.
15083
15084 procedure Derive_Interface_Subprogram
15085 (New_Subp : out Entity_Id;
15086 Subp : Entity_Id;
15087 Actual_Subp : Entity_Id);
15088 -- Derive New_Subp from the ultimate alias of the parent subprogram Subp
15089 -- (which is an interface primitive). If Generic_Actual is present then
15090 -- Actual_Subp is the actual subprogram corresponding with the generic
15091 -- subprogram Subp.
15092
15093 function Check_Derived_Type return Boolean is
15094 E : Entity_Id;
15095 Elmt : Elmt_Id;
15096 List : Elist_Id;
15097 New_Subp : Entity_Id;
15098 Op_Elmt : Elmt_Id;
15099 Subp : Entity_Id;
15100
15101 begin
15102 -- Traverse list of entities in the current scope searching for
15103 -- an incomplete type whose full-view is derived type
15104
15105 E := First_Entity (Scope (Derived_Type));
15106 while Present (E) and then E /= Derived_Type loop
15107 if Ekind (E) = E_Incomplete_Type
15108 and then Present (Full_View (E))
15109 and then Full_View (E) = Derived_Type
15110 then
15111 -- Disable this test if Derived_Type completes an incomplete
15112 -- type because in such case more primitives can be added
15113 -- later to the list of primitives of Derived_Type by routine
15114 -- Process_Incomplete_Dependents
15115
15116 return True;
15117 end if;
15118
15119 E := Next_Entity (E);
15120 end loop;
15121
15122 List := Collect_Primitive_Operations (Derived_Type);
15123 Elmt := First_Elmt (List);
15124
15125 Op_Elmt := First_Elmt (Op_List);
15126 while Present (Op_Elmt) loop
15127 Subp := Node (Op_Elmt);
15128 New_Subp := Node (Elmt);
15129
15130 -- At this early stage Derived_Type has no entities with attribute
15131 -- Interface_Alias. In addition, such primitives are always
15132 -- located at the end of the list of primitives of Parent_Type.
15133 -- Therefore, if found we can safely stop processing pending
15134 -- entities.
15135
15136 exit when Present (Interface_Alias (Subp));
15137
15138 -- Handle hidden entities
15139
15140 if not Is_Predefined_Dispatching_Operation (Subp)
15141 and then Is_Hidden (Subp)
15142 then
15143 if Present (New_Subp)
15144 and then Primitive_Names_Match (Subp, New_Subp)
15145 then
15146 Next_Elmt (Elmt);
15147 end if;
15148
15149 else
15150 if not Present (New_Subp)
15151 or else Ekind (Subp) /= Ekind (New_Subp)
15152 or else not Primitive_Names_Match (Subp, New_Subp)
15153 then
15154 return False;
15155 end if;
15156
15157 Next_Elmt (Elmt);
15158 end if;
15159
15160 Next_Elmt (Op_Elmt);
15161 end loop;
15162
15163 return True;
15164 end Check_Derived_Type;
15165
15166 ---------------------------------
15167 -- Derive_Interface_Subprogram --
15168 ---------------------------------
15169
15170 procedure Derive_Interface_Subprogram
15171 (New_Subp : out Entity_Id;
15172 Subp : Entity_Id;
15173 Actual_Subp : Entity_Id)
15174 is
15175 Iface_Subp : constant Entity_Id := Ultimate_Alias (Subp);
15176 Iface_Type : constant Entity_Id := Find_Dispatching_Type (Iface_Subp);
15177
15178 begin
15179 pragma Assert (Is_Interface (Iface_Type));
15180
15181 Derive_Subprogram
15182 (New_Subp => New_Subp,
15183 Parent_Subp => Iface_Subp,
15184 Derived_Type => Derived_Type,
15185 Parent_Type => Iface_Type,
15186 Actual_Subp => Actual_Subp);
15187
15188 -- Given that this new interface entity corresponds with a primitive
15189 -- of the parent that was not overridden we must leave it associated
15190 -- with its parent primitive to ensure that it will share the same
15191 -- dispatch table slot when overridden. We must set the Alias to Subp
15192 -- (instead of Iface_Subp), and we must fix Is_Abstract_Subprogram
15193 -- (in case we inherited Subp from Iface_Type via a nonabstract
15194 -- generic formal type).
15195
15196 if No (Actual_Subp) then
15197 Set_Alias (New_Subp, Subp);
15198
15199 declare
15200 T : Entity_Id := Find_Dispatching_Type (Subp);
15201 begin
15202 while Etype (T) /= T loop
15203 if Is_Generic_Type (T) and then not Is_Abstract_Type (T) then
15204 Set_Is_Abstract_Subprogram (New_Subp, False);
15205 exit;
15206 end if;
15207
15208 T := Etype (T);
15209 end loop;
15210 end;
15211
15212 -- For instantiations this is not needed since the previous call to
15213 -- Derive_Subprogram leaves the entity well decorated.
15214
15215 else
15216 pragma Assert (Alias (New_Subp) = Actual_Subp);
15217 null;
15218 end if;
15219 end Derive_Interface_Subprogram;
15220
15221 -- Local variables
15222
15223 Alias_Subp : Entity_Id;
15224 Act_List : Elist_Id;
15225 Act_Elmt : Elmt_Id;
15226 Act_Subp : Entity_Id := Empty;
15227 Elmt : Elmt_Id;
15228 Need_Search : Boolean := False;
15229 New_Subp : Entity_Id := Empty;
15230 Parent_Base : Entity_Id;
15231 Subp : Entity_Id;
15232
15233 -- Start of processing for Derive_Subprograms
15234
15235 begin
15236 if Ekind (Parent_Type) = E_Record_Type_With_Private
15237 and then Has_Discriminants (Parent_Type)
15238 and then Present (Full_View (Parent_Type))
15239 then
15240 Parent_Base := Full_View (Parent_Type);
15241 else
15242 Parent_Base := Parent_Type;
15243 end if;
15244
15245 if Present (Generic_Actual) then
15246 Act_List := Collect_Primitive_Operations (Generic_Actual);
15247 Act_Elmt := First_Elmt (Act_List);
15248 else
15249 Act_List := No_Elist;
15250 Act_Elmt := No_Elmt;
15251 end if;
15252
15253 -- Derive primitives inherited from the parent. Note that if the generic
15254 -- actual is present, this is not really a type derivation, it is a
15255 -- completion within an instance.
15256
15257 -- Case 1: Derived_Type does not implement interfaces
15258
15259 if not Is_Tagged_Type (Derived_Type)
15260 or else (not Has_Interfaces (Derived_Type)
15261 and then not (Present (Generic_Actual)
15262 and then Has_Interfaces (Generic_Actual)))
15263 then
15264 Elmt := First_Elmt (Op_List);
15265 while Present (Elmt) loop
15266 Subp := Node (Elmt);
15267
15268 -- Literals are derived earlier in the process of building the
15269 -- derived type, and are skipped here.
15270
15271 if Ekind (Subp) = E_Enumeration_Literal then
15272 null;
15273
15274 -- The actual is a direct descendant and the common primitive
15275 -- operations appear in the same order.
15276
15277 -- If the generic parent type is present, the derived type is an
15278 -- instance of a formal derived type, and within the instance its
15279 -- operations are those of the actual. We derive from the formal
15280 -- type but make the inherited operations aliases of the
15281 -- corresponding operations of the actual.
15282
15283 else
15284 pragma Assert (No (Node (Act_Elmt))
15285 or else (Primitive_Names_Match (Subp, Node (Act_Elmt))
15286 and then
15287 Type_Conformant
15288 (Subp, Node (Act_Elmt),
15289 Skip_Controlling_Formals => True)));
15290
15291 Derive_Subprogram
15292 (New_Subp, Subp, Derived_Type, Parent_Base, Node (Act_Elmt));
15293
15294 if Present (Act_Elmt) then
15295 Next_Elmt (Act_Elmt);
15296 end if;
15297 end if;
15298
15299 Next_Elmt (Elmt);
15300 end loop;
15301
15302 -- Case 2: Derived_Type implements interfaces
15303
15304 else
15305 -- If the parent type has no predefined primitives we remove
15306 -- predefined primitives from the list of primitives of generic
15307 -- actual to simplify the complexity of this algorithm.
15308
15309 if Present (Generic_Actual) then
15310 declare
15311 Has_Predefined_Primitives : Boolean := False;
15312
15313 begin
15314 -- Check if the parent type has predefined primitives
15315
15316 Elmt := First_Elmt (Op_List);
15317 while Present (Elmt) loop
15318 Subp := Node (Elmt);
15319
15320 if Is_Predefined_Dispatching_Operation (Subp)
15321 and then not Comes_From_Source (Ultimate_Alias (Subp))
15322 then
15323 Has_Predefined_Primitives := True;
15324 exit;
15325 end if;
15326
15327 Next_Elmt (Elmt);
15328 end loop;
15329
15330 -- Remove predefined primitives of Generic_Actual. We must use
15331 -- an auxiliary list because in case of tagged types the value
15332 -- returned by Collect_Primitive_Operations is the value stored
15333 -- in its Primitive_Operations attribute (and we don't want to
15334 -- modify its current contents).
15335
15336 if not Has_Predefined_Primitives then
15337 declare
15338 Aux_List : constant Elist_Id := New_Elmt_List;
15339
15340 begin
15341 Elmt := First_Elmt (Act_List);
15342 while Present (Elmt) loop
15343 Subp := Node (Elmt);
15344
15345 if not Is_Predefined_Dispatching_Operation (Subp)
15346 or else Comes_From_Source (Subp)
15347 then
15348 Append_Elmt (Subp, Aux_List);
15349 end if;
15350
15351 Next_Elmt (Elmt);
15352 end loop;
15353
15354 Act_List := Aux_List;
15355 end;
15356 end if;
15357
15358 Act_Elmt := First_Elmt (Act_List);
15359 Act_Subp := Node (Act_Elmt);
15360 end;
15361 end if;
15362
15363 -- Stage 1: If the generic actual is not present we derive the
15364 -- primitives inherited from the parent type. If the generic parent
15365 -- type is present, the derived type is an instance of a formal
15366 -- derived type, and within the instance its operations are those of
15367 -- the actual. We derive from the formal type but make the inherited
15368 -- operations aliases of the corresponding operations of the actual.
15369
15370 Elmt := First_Elmt (Op_List);
15371 while Present (Elmt) loop
15372 Subp := Node (Elmt);
15373 Alias_Subp := Ultimate_Alias (Subp);
15374
15375 -- Do not derive internal entities of the parent that link
15376 -- interface primitives with their covering primitive. These
15377 -- entities will be added to this type when frozen.
15378
15379 if Present (Interface_Alias (Subp)) then
15380 goto Continue;
15381 end if;
15382
15383 -- If the generic actual is present find the corresponding
15384 -- operation in the generic actual. If the parent type is a
15385 -- direct ancestor of the derived type then, even if it is an
15386 -- interface, the operations are inherited from the primary
15387 -- dispatch table and are in the proper order. If we detect here
15388 -- that primitives are not in the same order we traverse the list
15389 -- of primitive operations of the actual to find the one that
15390 -- implements the interface primitive.
15391
15392 if Need_Search
15393 or else
15394 (Present (Generic_Actual)
15395 and then Present (Act_Subp)
15396 and then not
15397 (Primitive_Names_Match (Subp, Act_Subp)
15398 and then
15399 Type_Conformant (Subp, Act_Subp,
15400 Skip_Controlling_Formals => True)))
15401 then
15402 pragma Assert (not Is_Ancestor (Parent_Base, Generic_Actual,
15403 Use_Full_View => True));
15404
15405 -- Remember that we need searching for all pending primitives
15406
15407 Need_Search := True;
15408
15409 -- Handle entities associated with interface primitives
15410
15411 if Present (Alias_Subp)
15412 and then Is_Interface (Find_Dispatching_Type (Alias_Subp))
15413 and then not Is_Predefined_Dispatching_Operation (Subp)
15414 then
15415 -- Search for the primitive in the homonym chain
15416
15417 Act_Subp :=
15418 Find_Primitive_Covering_Interface
15419 (Tagged_Type => Generic_Actual,
15420 Iface_Prim => Alias_Subp);
15421
15422 -- Previous search may not locate primitives covering
15423 -- interfaces defined in generics units or instantiations.
15424 -- (it fails if the covering primitive has formals whose
15425 -- type is also defined in generics or instantiations).
15426 -- In such case we search in the list of primitives of the
15427 -- generic actual for the internal entity that links the
15428 -- interface primitive and the covering primitive.
15429
15430 if No (Act_Subp)
15431 and then Is_Generic_Type (Parent_Type)
15432 then
15433 -- This code has been designed to handle only generic
15434 -- formals that implement interfaces that are defined
15435 -- in a generic unit or instantiation. If this code is
15436 -- needed for other cases we must review it because
15437 -- (given that it relies on Original_Location to locate
15438 -- the primitive of Generic_Actual that covers the
15439 -- interface) it could leave linked through attribute
15440 -- Alias entities of unrelated instantiations).
15441
15442 pragma Assert
15443 (Is_Generic_Unit
15444 (Scope (Find_Dispatching_Type (Alias_Subp)))
15445 or else
15446 Instantiation_Depth
15447 (Sloc (Find_Dispatching_Type (Alias_Subp))) > 0);
15448
15449 declare
15450 Iface_Prim_Loc : constant Source_Ptr :=
15451 Original_Location (Sloc (Alias_Subp));
15452
15453 Elmt : Elmt_Id;
15454 Prim : Entity_Id;
15455
15456 begin
15457 Elmt :=
15458 First_Elmt (Primitive_Operations (Generic_Actual));
15459
15460 Search : while Present (Elmt) loop
15461 Prim := Node (Elmt);
15462
15463 if Present (Interface_Alias (Prim))
15464 and then Original_Location
15465 (Sloc (Interface_Alias (Prim))) =
15466 Iface_Prim_Loc
15467 then
15468 Act_Subp := Alias (Prim);
15469 exit Search;
15470 end if;
15471
15472 Next_Elmt (Elmt);
15473 end loop Search;
15474 end;
15475 end if;
15476
15477 pragma Assert (Present (Act_Subp)
15478 or else Is_Abstract_Type (Generic_Actual)
15479 or else Serious_Errors_Detected > 0);
15480
15481 -- Handle predefined primitives plus the rest of user-defined
15482 -- primitives
15483
15484 else
15485 Act_Elmt := First_Elmt (Act_List);
15486 while Present (Act_Elmt) loop
15487 Act_Subp := Node (Act_Elmt);
15488
15489 exit when Primitive_Names_Match (Subp, Act_Subp)
15490 and then Type_Conformant
15491 (Subp, Act_Subp,
15492 Skip_Controlling_Formals => True)
15493 and then No (Interface_Alias (Act_Subp));
15494
15495 Next_Elmt (Act_Elmt);
15496 end loop;
15497
15498 if No (Act_Elmt) then
15499 Act_Subp := Empty;
15500 end if;
15501 end if;
15502 end if;
15503
15504 -- Case 1: If the parent is a limited interface then it has the
15505 -- predefined primitives of synchronized interfaces. However, the
15506 -- actual type may be a non-limited type and hence it does not
15507 -- have such primitives.
15508
15509 if Present (Generic_Actual)
15510 and then not Present (Act_Subp)
15511 and then Is_Limited_Interface (Parent_Base)
15512 and then Is_Predefined_Interface_Primitive (Subp)
15513 then
15514 null;
15515
15516 -- Case 2: Inherit entities associated with interfaces that were
15517 -- not covered by the parent type. We exclude here null interface
15518 -- primitives because they do not need special management.
15519
15520 -- We also exclude interface operations that are renamings. If the
15521 -- subprogram is an explicit renaming of an interface primitive,
15522 -- it is a regular primitive operation, and the presence of its
15523 -- alias is not relevant: it has to be derived like any other
15524 -- primitive.
15525
15526 elsif Present (Alias (Subp))
15527 and then Nkind (Unit_Declaration_Node (Subp)) /=
15528 N_Subprogram_Renaming_Declaration
15529 and then Is_Interface (Find_Dispatching_Type (Alias_Subp))
15530 and then not
15531 (Nkind (Parent (Alias_Subp)) = N_Procedure_Specification
15532 and then Null_Present (Parent (Alias_Subp)))
15533 then
15534 -- If this is an abstract private type then we transfer the
15535 -- derivation of the interface primitive from the partial view
15536 -- to the full view. This is safe because all the interfaces
15537 -- must be visible in the partial view. Done to avoid adding
15538 -- a new interface derivation to the private part of the
15539 -- enclosing package; otherwise this new derivation would be
15540 -- decorated as hidden when the analysis of the enclosing
15541 -- package completes.
15542
15543 if Is_Abstract_Type (Derived_Type)
15544 and then In_Private_Part (Current_Scope)
15545 and then Has_Private_Declaration (Derived_Type)
15546 then
15547 declare
15548 Partial_View : Entity_Id;
15549 Elmt : Elmt_Id;
15550 Ent : Entity_Id;
15551
15552 begin
15553 Partial_View := First_Entity (Current_Scope);
15554 loop
15555 exit when No (Partial_View)
15556 or else (Has_Private_Declaration (Partial_View)
15557 and then
15558 Full_View (Partial_View) = Derived_Type);
15559
15560 Next_Entity (Partial_View);
15561 end loop;
15562
15563 -- If the partial view was not found then the source code
15564 -- has errors and the derivation is not needed.
15565
15566 if Present (Partial_View) then
15567 Elmt :=
15568 First_Elmt (Primitive_Operations (Partial_View));
15569 while Present (Elmt) loop
15570 Ent := Node (Elmt);
15571
15572 if Present (Alias (Ent))
15573 and then Ultimate_Alias (Ent) = Alias (Subp)
15574 then
15575 Append_Elmt
15576 (Ent, Primitive_Operations (Derived_Type));
15577 exit;
15578 end if;
15579
15580 Next_Elmt (Elmt);
15581 end loop;
15582
15583 -- If the interface primitive was not found in the
15584 -- partial view then this interface primitive was
15585 -- overridden. We add a derivation to activate in
15586 -- Derive_Progenitor_Subprograms the machinery to
15587 -- search for it.
15588
15589 if No (Elmt) then
15590 Derive_Interface_Subprogram
15591 (New_Subp => New_Subp,
15592 Subp => Subp,
15593 Actual_Subp => Act_Subp);
15594 end if;
15595 end if;
15596 end;
15597 else
15598 Derive_Interface_Subprogram
15599 (New_Subp => New_Subp,
15600 Subp => Subp,
15601 Actual_Subp => Act_Subp);
15602 end if;
15603
15604 -- Case 3: Common derivation
15605
15606 else
15607 Derive_Subprogram
15608 (New_Subp => New_Subp,
15609 Parent_Subp => Subp,
15610 Derived_Type => Derived_Type,
15611 Parent_Type => Parent_Base,
15612 Actual_Subp => Act_Subp);
15613 end if;
15614
15615 -- No need to update Act_Elm if we must search for the
15616 -- corresponding operation in the generic actual
15617
15618 if not Need_Search
15619 and then Present (Act_Elmt)
15620 then
15621 Next_Elmt (Act_Elmt);
15622 Act_Subp := Node (Act_Elmt);
15623 end if;
15624
15625 <<Continue>>
15626 Next_Elmt (Elmt);
15627 end loop;
15628
15629 -- Inherit additional operations from progenitors. If the derived
15630 -- type is a generic actual, there are not new primitive operations
15631 -- for the type because it has those of the actual, and therefore
15632 -- nothing needs to be done. The renamings generated above are not
15633 -- primitive operations, and their purpose is simply to make the
15634 -- proper operations visible within an instantiation.
15635
15636 if No (Generic_Actual) then
15637 Derive_Progenitor_Subprograms (Parent_Base, Derived_Type);
15638 end if;
15639 end if;
15640
15641 -- Final check: Direct descendants must have their primitives in the
15642 -- same order. We exclude from this test untagged types and instances
15643 -- of formal derived types. We skip this test if we have already
15644 -- reported serious errors in the sources.
15645
15646 pragma Assert (not Is_Tagged_Type (Derived_Type)
15647 or else Present (Generic_Actual)
15648 or else Serious_Errors_Detected > 0
15649 or else Check_Derived_Type);
15650 end Derive_Subprograms;
15651
15652 --------------------------------
15653 -- Derived_Standard_Character --
15654 --------------------------------
15655
15656 procedure Derived_Standard_Character
15657 (N : Node_Id;
15658 Parent_Type : Entity_Id;
15659 Derived_Type : Entity_Id)
15660 is
15661 Loc : constant Source_Ptr := Sloc (N);
15662 Def : constant Node_Id := Type_Definition (N);
15663 Indic : constant Node_Id := Subtype_Indication (Def);
15664 Parent_Base : constant Entity_Id := Base_Type (Parent_Type);
15665 Implicit_Base : constant Entity_Id :=
15666 Create_Itype
15667 (E_Enumeration_Type, N, Derived_Type, 'B');
15668
15669 Lo : Node_Id;
15670 Hi : Node_Id;
15671
15672 begin
15673 Discard_Node (Process_Subtype (Indic, N));
15674
15675 Set_Etype (Implicit_Base, Parent_Base);
15676 Set_Size_Info (Implicit_Base, Root_Type (Parent_Type));
15677 Set_RM_Size (Implicit_Base, RM_Size (Root_Type (Parent_Type)));
15678
15679 Set_Is_Character_Type (Implicit_Base, True);
15680 Set_Has_Delayed_Freeze (Implicit_Base);
15681
15682 -- The bounds of the implicit base are the bounds of the parent base.
15683 -- Note that their type is the parent base.
15684
15685 Lo := New_Copy_Tree (Type_Low_Bound (Parent_Base));
15686 Hi := New_Copy_Tree (Type_High_Bound (Parent_Base));
15687
15688 Set_Scalar_Range (Implicit_Base,
15689 Make_Range (Loc,
15690 Low_Bound => Lo,
15691 High_Bound => Hi));
15692
15693 Conditional_Delay (Derived_Type, Parent_Type);
15694
15695 Set_Ekind (Derived_Type, E_Enumeration_Subtype);
15696 Set_Etype (Derived_Type, Implicit_Base);
15697 Set_Size_Info (Derived_Type, Parent_Type);
15698
15699 if Unknown_RM_Size (Derived_Type) then
15700 Set_RM_Size (Derived_Type, RM_Size (Parent_Type));
15701 end if;
15702
15703 Set_Is_Character_Type (Derived_Type, True);
15704
15705 if Nkind (Indic) /= N_Subtype_Indication then
15706
15707 -- If no explicit constraint, the bounds are those
15708 -- of the parent type.
15709
15710 Lo := New_Copy_Tree (Type_Low_Bound (Parent_Type));
15711 Hi := New_Copy_Tree (Type_High_Bound (Parent_Type));
15712 Set_Scalar_Range (Derived_Type, Make_Range (Loc, Lo, Hi));
15713 end if;
15714
15715 Convert_Scalar_Bounds (N, Parent_Type, Derived_Type, Loc);
15716
15717 -- Because the implicit base is used in the conversion of the bounds, we
15718 -- have to freeze it now. This is similar to what is done for numeric
15719 -- types, and it equally suspicious, but otherwise a non-static bound
15720 -- will have a reference to an unfrozen type, which is rejected by Gigi
15721 -- (???). This requires specific care for definition of stream
15722 -- attributes. For details, see comments at the end of
15723 -- Build_Derived_Numeric_Type.
15724
15725 Freeze_Before (N, Implicit_Base);
15726 end Derived_Standard_Character;
15727
15728 ------------------------------
15729 -- Derived_Type_Declaration --
15730 ------------------------------
15731
15732 procedure Derived_Type_Declaration
15733 (T : Entity_Id;
15734 N : Node_Id;
15735 Is_Completion : Boolean)
15736 is
15737 Parent_Type : Entity_Id;
15738
15739 function Comes_From_Generic (Typ : Entity_Id) return Boolean;
15740 -- Check whether the parent type is a generic formal, or derives
15741 -- directly or indirectly from one.
15742
15743 ------------------------
15744 -- Comes_From_Generic --
15745 ------------------------
15746
15747 function Comes_From_Generic (Typ : Entity_Id) return Boolean is
15748 begin
15749 if Is_Generic_Type (Typ) then
15750 return True;
15751
15752 elsif Is_Generic_Type (Root_Type (Parent_Type)) then
15753 return True;
15754
15755 elsif Is_Private_Type (Typ)
15756 and then Present (Full_View (Typ))
15757 and then Is_Generic_Type (Root_Type (Full_View (Typ)))
15758 then
15759 return True;
15760
15761 elsif Is_Generic_Actual_Type (Typ) then
15762 return True;
15763
15764 else
15765 return False;
15766 end if;
15767 end Comes_From_Generic;
15768
15769 -- Local variables
15770
15771 Def : constant Node_Id := Type_Definition (N);
15772 Iface_Def : Node_Id;
15773 Indic : constant Node_Id := Subtype_Indication (Def);
15774 Extension : constant Node_Id := Record_Extension_Part (Def);
15775 Parent_Node : Node_Id;
15776 Taggd : Boolean;
15777
15778 -- Start of processing for Derived_Type_Declaration
15779
15780 begin
15781 Parent_Type := Find_Type_Of_Subtype_Indic (Indic);
15782
15783 -- Ada 2005 (AI-251): In case of interface derivation check that the
15784 -- parent is also an interface.
15785
15786 if Interface_Present (Def) then
15787 Check_SPARK_05_Restriction ("interface is not allowed", Def);
15788
15789 if not Is_Interface (Parent_Type) then
15790 Diagnose_Interface (Indic, Parent_Type);
15791
15792 else
15793 Parent_Node := Parent (Base_Type (Parent_Type));
15794 Iface_Def := Type_Definition (Parent_Node);
15795
15796 -- Ada 2005 (AI-251): Limited interfaces can only inherit from
15797 -- other limited interfaces.
15798
15799 if Limited_Present (Def) then
15800 if Limited_Present (Iface_Def) then
15801 null;
15802
15803 elsif Protected_Present (Iface_Def) then
15804 Error_Msg_NE
15805 ("descendant of & must be declared as a protected "
15806 & "interface", N, Parent_Type);
15807
15808 elsif Synchronized_Present (Iface_Def) then
15809 Error_Msg_NE
15810 ("descendant of & must be declared as a synchronized "
15811 & "interface", N, Parent_Type);
15812
15813 elsif Task_Present (Iface_Def) then
15814 Error_Msg_NE
15815 ("descendant of & must be declared as a task interface",
15816 N, Parent_Type);
15817
15818 else
15819 Error_Msg_N
15820 ("(Ada 2005) limited interface cannot inherit from "
15821 & "non-limited interface", Indic);
15822 end if;
15823
15824 -- Ada 2005 (AI-345): Non-limited interfaces can only inherit
15825 -- from non-limited or limited interfaces.
15826
15827 elsif not Protected_Present (Def)
15828 and then not Synchronized_Present (Def)
15829 and then not Task_Present (Def)
15830 then
15831 if Limited_Present (Iface_Def) then
15832 null;
15833
15834 elsif Protected_Present (Iface_Def) then
15835 Error_Msg_NE
15836 ("descendant of & must be declared as a protected "
15837 & "interface", N, Parent_Type);
15838
15839 elsif Synchronized_Present (Iface_Def) then
15840 Error_Msg_NE
15841 ("descendant of & must be declared as a synchronized "
15842 & "interface", N, Parent_Type);
15843
15844 elsif Task_Present (Iface_Def) then
15845 Error_Msg_NE
15846 ("descendant of & must be declared as a task interface",
15847 N, Parent_Type);
15848 else
15849 null;
15850 end if;
15851 end if;
15852 end if;
15853 end if;
15854
15855 if Is_Tagged_Type (Parent_Type)
15856 and then Is_Concurrent_Type (Parent_Type)
15857 and then not Is_Interface (Parent_Type)
15858 then
15859 Error_Msg_N
15860 ("parent type of a record extension cannot be a synchronized "
15861 & "tagged type (RM 3.9.1 (3/1))", N);
15862 Set_Etype (T, Any_Type);
15863 return;
15864 end if;
15865
15866 -- Ada 2005 (AI-251): Decorate all the names in the list of ancestor
15867 -- interfaces
15868
15869 if Is_Tagged_Type (Parent_Type)
15870 and then Is_Non_Empty_List (Interface_List (Def))
15871 then
15872 declare
15873 Intf : Node_Id;
15874 T : Entity_Id;
15875
15876 begin
15877 Intf := First (Interface_List (Def));
15878 while Present (Intf) loop
15879 T := Find_Type_Of_Subtype_Indic (Intf);
15880
15881 if not Is_Interface (T) then
15882 Diagnose_Interface (Intf, T);
15883
15884 -- Check the rules of 3.9.4(12/2) and 7.5(2/2) that disallow
15885 -- a limited type from having a nonlimited progenitor.
15886
15887 elsif (Limited_Present (Def)
15888 or else (not Is_Interface (Parent_Type)
15889 and then Is_Limited_Type (Parent_Type)))
15890 and then not Is_Limited_Interface (T)
15891 then
15892 Error_Msg_NE
15893 ("progenitor interface& of limited type must be limited",
15894 N, T);
15895 end if;
15896
15897 Next (Intf);
15898 end loop;
15899 end;
15900 end if;
15901
15902 if Parent_Type = Any_Type
15903 or else Etype (Parent_Type) = Any_Type
15904 or else (Is_Class_Wide_Type (Parent_Type)
15905 and then Etype (Parent_Type) = T)
15906 then
15907 -- If Parent_Type is undefined or illegal, make new type into a
15908 -- subtype of Any_Type, and set a few attributes to prevent cascaded
15909 -- errors. If this is a self-definition, emit error now.
15910
15911 if T = Parent_Type or else T = Etype (Parent_Type) then
15912 Error_Msg_N ("type cannot be used in its own definition", Indic);
15913 end if;
15914
15915 Set_Ekind (T, Ekind (Parent_Type));
15916 Set_Etype (T, Any_Type);
15917 Set_Scalar_Range (T, Scalar_Range (Any_Type));
15918
15919 if Is_Tagged_Type (T)
15920 and then Is_Record_Type (T)
15921 then
15922 Set_Direct_Primitive_Operations (T, New_Elmt_List);
15923 end if;
15924
15925 return;
15926 end if;
15927
15928 -- Ada 2005 (AI-251): The case in which the parent of the full-view is
15929 -- an interface is special because the list of interfaces in the full
15930 -- view can be given in any order. For example:
15931
15932 -- type A is interface;
15933 -- type B is interface and A;
15934 -- type D is new B with private;
15935 -- private
15936 -- type D is new A and B with null record; -- 1 --
15937
15938 -- In this case we perform the following transformation of -1-:
15939
15940 -- type D is new B and A with null record;
15941
15942 -- If the parent of the full-view covers the parent of the partial-view
15943 -- we have two possible cases:
15944
15945 -- 1) They have the same parent
15946 -- 2) The parent of the full-view implements some further interfaces
15947
15948 -- In both cases we do not need to perform the transformation. In the
15949 -- first case the source program is correct and the transformation is
15950 -- not needed; in the second case the source program does not fulfill
15951 -- the no-hidden interfaces rule (AI-396) and the error will be reported
15952 -- later.
15953
15954 -- This transformation not only simplifies the rest of the analysis of
15955 -- this type declaration but also simplifies the correct generation of
15956 -- the object layout to the expander.
15957
15958 if In_Private_Part (Current_Scope)
15959 and then Is_Interface (Parent_Type)
15960 then
15961 declare
15962 Iface : Node_Id;
15963 Partial_View : Entity_Id;
15964 Partial_View_Parent : Entity_Id;
15965 New_Iface : Node_Id;
15966
15967 begin
15968 -- Look for the associated private type declaration
15969
15970 Partial_View := First_Entity (Current_Scope);
15971 loop
15972 exit when No (Partial_View)
15973 or else (Has_Private_Declaration (Partial_View)
15974 and then Full_View (Partial_View) = T);
15975
15976 Next_Entity (Partial_View);
15977 end loop;
15978
15979 -- If the partial view was not found then the source code has
15980 -- errors and the transformation is not needed.
15981
15982 if Present (Partial_View) then
15983 Partial_View_Parent := Etype (Partial_View);
15984
15985 -- If the parent of the full-view covers the parent of the
15986 -- partial-view we have nothing else to do.
15987
15988 if Interface_Present_In_Ancestor
15989 (Parent_Type, Partial_View_Parent)
15990 then
15991 null;
15992
15993 -- Traverse the list of interfaces of the full-view to look
15994 -- for the parent of the partial-view and perform the tree
15995 -- transformation.
15996
15997 else
15998 Iface := First (Interface_List (Def));
15999 while Present (Iface) loop
16000 if Etype (Iface) = Etype (Partial_View) then
16001 Rewrite (Subtype_Indication (Def),
16002 New_Copy (Subtype_Indication
16003 (Parent (Partial_View))));
16004
16005 New_Iface :=
16006 Make_Identifier (Sloc (N), Chars (Parent_Type));
16007 Append (New_Iface, Interface_List (Def));
16008
16009 -- Analyze the transformed code
16010
16011 Derived_Type_Declaration (T, N, Is_Completion);
16012 return;
16013 end if;
16014
16015 Next (Iface);
16016 end loop;
16017 end if;
16018 end if;
16019 end;
16020 end if;
16021
16022 -- Only composite types other than array types are allowed to have
16023 -- discriminants.
16024
16025 if Present (Discriminant_Specifications (N)) then
16026 if (Is_Elementary_Type (Parent_Type)
16027 or else
16028 Is_Array_Type (Parent_Type))
16029 and then not Error_Posted (N)
16030 then
16031 Error_Msg_N
16032 ("elementary or array type cannot have discriminants",
16033 Defining_Identifier (First (Discriminant_Specifications (N))));
16034 Set_Has_Discriminants (T, False);
16035
16036 -- The type is allowed to have discriminants
16037
16038 else
16039 Check_SPARK_05_Restriction ("discriminant type is not allowed", N);
16040 end if;
16041 end if;
16042
16043 -- In Ada 83, a derived type defined in a package specification cannot
16044 -- be used for further derivation until the end of its visible part.
16045 -- Note that derivation in the private part of the package is allowed.
16046
16047 if Ada_Version = Ada_83
16048 and then Is_Derived_Type (Parent_Type)
16049 and then In_Visible_Part (Scope (Parent_Type))
16050 then
16051 if Ada_Version = Ada_83 and then Comes_From_Source (Indic) then
16052 Error_Msg_N
16053 ("(Ada 83): premature use of type for derivation", Indic);
16054 end if;
16055 end if;
16056
16057 -- Check for early use of incomplete or private type
16058
16059 if Ekind_In (Parent_Type, E_Void, E_Incomplete_Type) then
16060 Error_Msg_N ("premature derivation of incomplete type", Indic);
16061 return;
16062
16063 elsif (Is_Incomplete_Or_Private_Type (Parent_Type)
16064 and then not Comes_From_Generic (Parent_Type))
16065 or else Has_Private_Component (Parent_Type)
16066 then
16067 -- The ancestor type of a formal type can be incomplete, in which
16068 -- case only the operations of the partial view are available in the
16069 -- generic. Subsequent checks may be required when the full view is
16070 -- analyzed to verify that a derivation from a tagged type has an
16071 -- extension.
16072
16073 if Nkind (Original_Node (N)) = N_Formal_Type_Declaration then
16074 null;
16075
16076 elsif No (Underlying_Type (Parent_Type))
16077 or else Has_Private_Component (Parent_Type)
16078 then
16079 Error_Msg_N
16080 ("premature derivation of derived or private type", Indic);
16081
16082 -- Flag the type itself as being in error, this prevents some
16083 -- nasty problems with subsequent uses of the malformed type.
16084
16085 Set_Error_Posted (T);
16086
16087 -- Check that within the immediate scope of an untagged partial
16088 -- view it's illegal to derive from the partial view if the
16089 -- full view is tagged. (7.3(7))
16090
16091 -- We verify that the Parent_Type is a partial view by checking
16092 -- that it is not a Full_Type_Declaration (i.e. a private type or
16093 -- private extension declaration), to distinguish a partial view
16094 -- from a derivation from a private type which also appears as
16095 -- E_Private_Type. If the parent base type is not declared in an
16096 -- enclosing scope there is no need to check.
16097
16098 elsif Present (Full_View (Parent_Type))
16099 and then Nkind (Parent (Parent_Type)) /= N_Full_Type_Declaration
16100 and then not Is_Tagged_Type (Parent_Type)
16101 and then Is_Tagged_Type (Full_View (Parent_Type))
16102 and then In_Open_Scopes (Scope (Base_Type (Parent_Type)))
16103 then
16104 Error_Msg_N
16105 ("premature derivation from type with tagged full view",
16106 Indic);
16107 end if;
16108 end if;
16109
16110 -- Check that form of derivation is appropriate
16111
16112 Taggd := Is_Tagged_Type (Parent_Type);
16113
16114 -- Set the parent type to the class-wide type's specific type in this
16115 -- case to prevent cascading errors
16116
16117 if Present (Extension) and then Is_Class_Wide_Type (Parent_Type) then
16118 Error_Msg_N ("parent type must not be a class-wide type", Indic);
16119 Set_Etype (T, Etype (Parent_Type));
16120 return;
16121 end if;
16122
16123 if Present (Extension) and then not Taggd then
16124 Error_Msg_N
16125 ("type derived from untagged type cannot have extension", Indic);
16126
16127 elsif No (Extension) and then Taggd then
16128
16129 -- If this declaration is within a private part (or body) of a
16130 -- generic instantiation then the derivation is allowed (the parent
16131 -- type can only appear tagged in this case if it's a generic actual
16132 -- type, since it would otherwise have been rejected in the analysis
16133 -- of the generic template).
16134
16135 if not Is_Generic_Actual_Type (Parent_Type)
16136 or else In_Visible_Part (Scope (Parent_Type))
16137 then
16138 if Is_Class_Wide_Type (Parent_Type) then
16139 Error_Msg_N
16140 ("parent type must not be a class-wide type", Indic);
16141
16142 -- Use specific type to prevent cascaded errors.
16143
16144 Parent_Type := Etype (Parent_Type);
16145
16146 else
16147 Error_Msg_N
16148 ("type derived from tagged type must have extension", Indic);
16149 end if;
16150 end if;
16151 end if;
16152
16153 -- AI-443: Synchronized formal derived types require a private
16154 -- extension. There is no point in checking the ancestor type or
16155 -- the progenitors since the construct is wrong to begin with.
16156
16157 if Ada_Version >= Ada_2005
16158 and then Is_Generic_Type (T)
16159 and then Present (Original_Node (N))
16160 then
16161 declare
16162 Decl : constant Node_Id := Original_Node (N);
16163
16164 begin
16165 if Nkind (Decl) = N_Formal_Type_Declaration
16166 and then Nkind (Formal_Type_Definition (Decl)) =
16167 N_Formal_Derived_Type_Definition
16168 and then Synchronized_Present (Formal_Type_Definition (Decl))
16169 and then No (Extension)
16170
16171 -- Avoid emitting a duplicate error message
16172
16173 and then not Error_Posted (Indic)
16174 then
16175 Error_Msg_N
16176 ("synchronized derived type must have extension", N);
16177 end if;
16178 end;
16179 end if;
16180
16181 if Null_Exclusion_Present (Def)
16182 and then not Is_Access_Type (Parent_Type)
16183 then
16184 Error_Msg_N ("null exclusion can only apply to an access type", N);
16185 end if;
16186
16187 -- Avoid deriving parent primitives of underlying record views
16188
16189 Build_Derived_Type (N, Parent_Type, T, Is_Completion,
16190 Derive_Subps => not Is_Underlying_Record_View (T));
16191
16192 -- AI-419: The parent type of an explicitly limited derived type must
16193 -- be a limited type or a limited interface.
16194
16195 if Limited_Present (Def) then
16196 Set_Is_Limited_Record (T);
16197
16198 if Is_Interface (T) then
16199 Set_Is_Limited_Interface (T);
16200 end if;
16201
16202 if not Is_Limited_Type (Parent_Type)
16203 and then
16204 (not Is_Interface (Parent_Type)
16205 or else not Is_Limited_Interface (Parent_Type))
16206 then
16207 -- AI05-0096: a derivation in the private part of an instance is
16208 -- legal if the generic formal is untagged limited, and the actual
16209 -- is non-limited.
16210
16211 if Is_Generic_Actual_Type (Parent_Type)
16212 and then In_Private_Part (Current_Scope)
16213 and then
16214 not Is_Tagged_Type
16215 (Generic_Parent_Type (Parent (Parent_Type)))
16216 then
16217 null;
16218
16219 else
16220 Error_Msg_NE
16221 ("parent type& of limited type must be limited",
16222 N, Parent_Type);
16223 end if;
16224 end if;
16225 end if;
16226
16227 -- In SPARK, there are no derived type definitions other than type
16228 -- extensions of tagged record types.
16229
16230 if No (Extension) then
16231 Check_SPARK_05_Restriction
16232 ("derived type is not allowed", Original_Node (N));
16233 end if;
16234 end Derived_Type_Declaration;
16235
16236 ------------------------
16237 -- Diagnose_Interface --
16238 ------------------------
16239
16240 procedure Diagnose_Interface (N : Node_Id; E : Entity_Id) is
16241 begin
16242 if not Is_Interface (E) and then E /= Any_Type then
16243 Error_Msg_NE ("(Ada 2005) & must be an interface", N, E);
16244 end if;
16245 end Diagnose_Interface;
16246
16247 ----------------------------------
16248 -- Enumeration_Type_Declaration --
16249 ----------------------------------
16250
16251 procedure Enumeration_Type_Declaration (T : Entity_Id; Def : Node_Id) is
16252 Ev : Uint;
16253 L : Node_Id;
16254 R_Node : Node_Id;
16255 B_Node : Node_Id;
16256
16257 begin
16258 -- Create identifier node representing lower bound
16259
16260 B_Node := New_Node (N_Identifier, Sloc (Def));
16261 L := First (Literals (Def));
16262 Set_Chars (B_Node, Chars (L));
16263 Set_Entity (B_Node, L);
16264 Set_Etype (B_Node, T);
16265 Set_Is_Static_Expression (B_Node, True);
16266
16267 R_Node := New_Node (N_Range, Sloc (Def));
16268 Set_Low_Bound (R_Node, B_Node);
16269
16270 Set_Ekind (T, E_Enumeration_Type);
16271 Set_First_Literal (T, L);
16272 Set_Etype (T, T);
16273 Set_Is_Constrained (T);
16274
16275 Ev := Uint_0;
16276
16277 -- Loop through literals of enumeration type setting pos and rep values
16278 -- except that if the Ekind is already set, then it means the literal
16279 -- was already constructed (case of a derived type declaration and we
16280 -- should not disturb the Pos and Rep values.
16281
16282 while Present (L) loop
16283 if Ekind (L) /= E_Enumeration_Literal then
16284 Set_Ekind (L, E_Enumeration_Literal);
16285 Set_Enumeration_Pos (L, Ev);
16286 Set_Enumeration_Rep (L, Ev);
16287 Set_Is_Known_Valid (L, True);
16288 end if;
16289
16290 Set_Etype (L, T);
16291 New_Overloaded_Entity (L);
16292 Generate_Definition (L);
16293 Set_Convention (L, Convention_Intrinsic);
16294
16295 -- Case of character literal
16296
16297 if Nkind (L) = N_Defining_Character_Literal then
16298 Set_Is_Character_Type (T, True);
16299
16300 -- Check violation of No_Wide_Characters
16301
16302 if Restriction_Check_Required (No_Wide_Characters) then
16303 Get_Name_String (Chars (L));
16304
16305 if Name_Len >= 3 and then Name_Buffer (1 .. 2) = "QW" then
16306 Check_Restriction (No_Wide_Characters, L);
16307 end if;
16308 end if;
16309 end if;
16310
16311 Ev := Ev + 1;
16312 Next (L);
16313 end loop;
16314
16315 -- Now create a node representing upper bound
16316
16317 B_Node := New_Node (N_Identifier, Sloc (Def));
16318 Set_Chars (B_Node, Chars (Last (Literals (Def))));
16319 Set_Entity (B_Node, Last (Literals (Def)));
16320 Set_Etype (B_Node, T);
16321 Set_Is_Static_Expression (B_Node, True);
16322
16323 Set_High_Bound (R_Node, B_Node);
16324
16325 -- Initialize various fields of the type. Some of this information
16326 -- may be overwritten later through rep.clauses.
16327
16328 Set_Scalar_Range (T, R_Node);
16329 Set_RM_Size (T, UI_From_Int (Minimum_Size (T)));
16330 Set_Enum_Esize (T);
16331 Set_Enum_Pos_To_Rep (T, Empty);
16332
16333 -- Set Discard_Names if configuration pragma set, or if there is
16334 -- a parameterless pragma in the current declarative region
16335
16336 if Global_Discard_Names or else Discard_Names (Scope (T)) then
16337 Set_Discard_Names (T);
16338 end if;
16339
16340 -- Process end label if there is one
16341
16342 if Present (Def) then
16343 Process_End_Label (Def, 'e', T);
16344 end if;
16345 end Enumeration_Type_Declaration;
16346
16347 ---------------------------------
16348 -- Expand_To_Stored_Constraint --
16349 ---------------------------------
16350
16351 function Expand_To_Stored_Constraint
16352 (Typ : Entity_Id;
16353 Constraint : Elist_Id) return Elist_Id
16354 is
16355 Explicitly_Discriminated_Type : Entity_Id;
16356 Expansion : Elist_Id;
16357 Discriminant : Entity_Id;
16358
16359 function Type_With_Explicit_Discrims (Id : Entity_Id) return Entity_Id;
16360 -- Find the nearest type that actually specifies discriminants
16361
16362 ---------------------------------
16363 -- Type_With_Explicit_Discrims --
16364 ---------------------------------
16365
16366 function Type_With_Explicit_Discrims (Id : Entity_Id) return Entity_Id is
16367 Typ : constant E := Base_Type (Id);
16368
16369 begin
16370 if Ekind (Typ) in Incomplete_Or_Private_Kind then
16371 if Present (Full_View (Typ)) then
16372 return Type_With_Explicit_Discrims (Full_View (Typ));
16373 end if;
16374
16375 else
16376 if Has_Discriminants (Typ) then
16377 return Typ;
16378 end if;
16379 end if;
16380
16381 if Etype (Typ) = Typ then
16382 return Empty;
16383 elsif Has_Discriminants (Typ) then
16384 return Typ;
16385 else
16386 return Type_With_Explicit_Discrims (Etype (Typ));
16387 end if;
16388
16389 end Type_With_Explicit_Discrims;
16390
16391 -- Start of processing for Expand_To_Stored_Constraint
16392
16393 begin
16394 if No (Constraint) or else Is_Empty_Elmt_List (Constraint) then
16395 return No_Elist;
16396 end if;
16397
16398 Explicitly_Discriminated_Type := Type_With_Explicit_Discrims (Typ);
16399
16400 if No (Explicitly_Discriminated_Type) then
16401 return No_Elist;
16402 end if;
16403
16404 Expansion := New_Elmt_List;
16405
16406 Discriminant :=
16407 First_Stored_Discriminant (Explicitly_Discriminated_Type);
16408 while Present (Discriminant) loop
16409 Append_Elmt
16410 (Get_Discriminant_Value
16411 (Discriminant, Explicitly_Discriminated_Type, Constraint),
16412 To => Expansion);
16413 Next_Stored_Discriminant (Discriminant);
16414 end loop;
16415
16416 return Expansion;
16417 end Expand_To_Stored_Constraint;
16418
16419 ---------------------------
16420 -- Find_Hidden_Interface --
16421 ---------------------------
16422
16423 function Find_Hidden_Interface
16424 (Src : Elist_Id;
16425 Dest : Elist_Id) return Entity_Id
16426 is
16427 Iface : Entity_Id;
16428 Iface_Elmt : Elmt_Id;
16429
16430 begin
16431 if Present (Src) and then Present (Dest) then
16432 Iface_Elmt := First_Elmt (Src);
16433 while Present (Iface_Elmt) loop
16434 Iface := Node (Iface_Elmt);
16435
16436 if Is_Interface (Iface)
16437 and then not Contain_Interface (Iface, Dest)
16438 then
16439 return Iface;
16440 end if;
16441
16442 Next_Elmt (Iface_Elmt);
16443 end loop;
16444 end if;
16445
16446 return Empty;
16447 end Find_Hidden_Interface;
16448
16449 --------------------
16450 -- Find_Type_Name --
16451 --------------------
16452
16453 function Find_Type_Name (N : Node_Id) return Entity_Id is
16454 Id : constant Entity_Id := Defining_Identifier (N);
16455 New_Id : Entity_Id;
16456 Prev : Entity_Id;
16457 Prev_Par : Node_Id;
16458
16459 procedure Check_Duplicate_Aspects;
16460 -- Check that aspects specified in a completion have not been specified
16461 -- already in the partial view.
16462
16463 procedure Tag_Mismatch;
16464 -- Diagnose a tagged partial view whose full view is untagged. We post
16465 -- the message on the full view, with a reference to the previous
16466 -- partial view. The partial view can be private or incomplete, and
16467 -- these are handled in a different manner, so we determine the position
16468 -- of the error message from the respective slocs of both.
16469
16470 -----------------------------
16471 -- Check_Duplicate_Aspects --
16472 -----------------------------
16473
16474 procedure Check_Duplicate_Aspects is
16475 function Get_Partial_View_Aspect (Asp : Node_Id) return Node_Id;
16476 -- Return the corresponding aspect of the partial view which matches
16477 -- the aspect id of Asp. Return Empty is no such aspect exists.
16478
16479 -----------------------------
16480 -- Get_Partial_View_Aspect --
16481 -----------------------------
16482
16483 function Get_Partial_View_Aspect (Asp : Node_Id) return Node_Id is
16484 Asp_Id : constant Aspect_Id := Get_Aspect_Id (Asp);
16485 Prev_Asps : constant List_Id := Aspect_Specifications (Prev_Par);
16486 Prev_Asp : Node_Id;
16487
16488 begin
16489 if Present (Prev_Asps) then
16490 Prev_Asp := First (Prev_Asps);
16491 while Present (Prev_Asp) loop
16492 if Get_Aspect_Id (Prev_Asp) = Asp_Id then
16493 return Prev_Asp;
16494 end if;
16495
16496 Next (Prev_Asp);
16497 end loop;
16498 end if;
16499
16500 return Empty;
16501 end Get_Partial_View_Aspect;
16502
16503 -- Local variables
16504
16505 Full_Asps : constant List_Id := Aspect_Specifications (N);
16506 Full_Asp : Node_Id;
16507 Part_Asp : Node_Id;
16508
16509 -- Start of processing for Check_Duplicate_Aspects
16510
16511 begin
16512 if Present (Full_Asps) then
16513 Full_Asp := First (Full_Asps);
16514 while Present (Full_Asp) loop
16515 Part_Asp := Get_Partial_View_Aspect (Full_Asp);
16516
16517 -- An aspect and its class-wide counterpart are two distinct
16518 -- aspects and may apply to both views of an entity.
16519
16520 if Present (Part_Asp)
16521 and then Class_Present (Part_Asp) = Class_Present (Full_Asp)
16522 then
16523 Error_Msg_N
16524 ("aspect already specified in private declaration",
16525 Full_Asp);
16526
16527 Remove (Full_Asp);
16528 return;
16529 end if;
16530
16531 if Has_Discriminants (Prev)
16532 and then not Has_Unknown_Discriminants (Prev)
16533 and then Get_Aspect_Id (Full_Asp) =
16534 Aspect_Implicit_Dereference
16535 then
16536 Error_Msg_N
16537 ("cannot specify aspect if partial view has known "
16538 & "discriminants", Full_Asp);
16539 end if;
16540
16541 Next (Full_Asp);
16542 end loop;
16543 end if;
16544 end Check_Duplicate_Aspects;
16545
16546 ------------------
16547 -- Tag_Mismatch --
16548 ------------------
16549
16550 procedure Tag_Mismatch is
16551 begin
16552 if Sloc (Prev) < Sloc (Id) then
16553 if Ada_Version >= Ada_2012
16554 and then Nkind (N) = N_Private_Type_Declaration
16555 then
16556 Error_Msg_NE
16557 ("declaration of private } must be a tagged type ", Id, Prev);
16558 else
16559 Error_Msg_NE
16560 ("full declaration of } must be a tagged type ", Id, Prev);
16561 end if;
16562
16563 else
16564 if Ada_Version >= Ada_2012
16565 and then Nkind (N) = N_Private_Type_Declaration
16566 then
16567 Error_Msg_NE
16568 ("declaration of private } must be a tagged type ", Prev, Id);
16569 else
16570 Error_Msg_NE
16571 ("full declaration of } must be a tagged type ", Prev, Id);
16572 end if;
16573 end if;
16574 end Tag_Mismatch;
16575
16576 -- Start of processing for Find_Type_Name
16577
16578 begin
16579 -- Find incomplete declaration, if one was given
16580
16581 Prev := Current_Entity_In_Scope (Id);
16582
16583 -- New type declaration
16584
16585 if No (Prev) then
16586 Enter_Name (Id);
16587 return Id;
16588
16589 -- Previous declaration exists
16590
16591 else
16592 Prev_Par := Parent (Prev);
16593
16594 -- Error if not incomplete/private case except if previous
16595 -- declaration is implicit, etc. Enter_Name will emit error if
16596 -- appropriate.
16597
16598 if not Is_Incomplete_Or_Private_Type (Prev) then
16599 Enter_Name (Id);
16600 New_Id := Id;
16601
16602 -- Check invalid completion of private or incomplete type
16603
16604 elsif not Nkind_In (N, N_Full_Type_Declaration,
16605 N_Task_Type_Declaration,
16606 N_Protected_Type_Declaration)
16607 and then
16608 (Ada_Version < Ada_2012
16609 or else not Is_Incomplete_Type (Prev)
16610 or else not Nkind_In (N, N_Private_Type_Declaration,
16611 N_Private_Extension_Declaration))
16612 then
16613 -- Completion must be a full type declarations (RM 7.3(4))
16614
16615 Error_Msg_Sloc := Sloc (Prev);
16616 Error_Msg_NE ("invalid completion of }", Id, Prev);
16617
16618 -- Set scope of Id to avoid cascaded errors. Entity is never
16619 -- examined again, except when saving globals in generics.
16620
16621 Set_Scope (Id, Current_Scope);
16622 New_Id := Id;
16623
16624 -- If this is a repeated incomplete declaration, no further
16625 -- checks are possible.
16626
16627 if Nkind (N) = N_Incomplete_Type_Declaration then
16628 return Prev;
16629 end if;
16630
16631 -- Case of full declaration of incomplete type
16632
16633 elsif Ekind (Prev) = E_Incomplete_Type
16634 and then (Ada_Version < Ada_2012
16635 or else No (Full_View (Prev))
16636 or else not Is_Private_Type (Full_View (Prev)))
16637 then
16638 -- Indicate that the incomplete declaration has a matching full
16639 -- declaration. The defining occurrence of the incomplete
16640 -- declaration remains the visible one, and the procedure
16641 -- Get_Full_View dereferences it whenever the type is used.
16642
16643 if Present (Full_View (Prev)) then
16644 Error_Msg_NE ("invalid redeclaration of }", Id, Prev);
16645 end if;
16646
16647 Set_Full_View (Prev, Id);
16648 Append_Entity (Id, Current_Scope);
16649 Set_Is_Public (Id, Is_Public (Prev));
16650 Set_Is_Internal (Id);
16651 New_Id := Prev;
16652
16653 -- If the incomplete view is tagged, a class_wide type has been
16654 -- created already. Use it for the private type as well, in order
16655 -- to prevent multiple incompatible class-wide types that may be
16656 -- created for self-referential anonymous access components.
16657
16658 if Is_Tagged_Type (Prev)
16659 and then Present (Class_Wide_Type (Prev))
16660 then
16661 Set_Ekind (Id, Ekind (Prev)); -- will be reset later
16662 Set_Class_Wide_Type (Id, Class_Wide_Type (Prev));
16663
16664 -- The type of the classwide type is the current Id. Previously
16665 -- this was not done for private declarations because of order-
16666 -- of elaboration issues in the back-end, but gigi now handles
16667 -- this properly.
16668
16669 Set_Etype (Class_Wide_Type (Id), Id);
16670 end if;
16671
16672 -- Case of full declaration of private type
16673
16674 else
16675 -- If the private type was a completion of an incomplete type then
16676 -- update Prev to reference the private type
16677
16678 if Ada_Version >= Ada_2012
16679 and then Ekind (Prev) = E_Incomplete_Type
16680 and then Present (Full_View (Prev))
16681 and then Is_Private_Type (Full_View (Prev))
16682 then
16683 Prev := Full_View (Prev);
16684 Prev_Par := Parent (Prev);
16685 end if;
16686
16687 if Nkind (N) = N_Full_Type_Declaration
16688 and then Nkind_In
16689 (Type_Definition (N), N_Record_Definition,
16690 N_Derived_Type_Definition)
16691 and then Interface_Present (Type_Definition (N))
16692 then
16693 Error_Msg_N
16694 ("completion of private type cannot be an interface", N);
16695 end if;
16696
16697 if Nkind (Parent (Prev)) /= N_Private_Extension_Declaration then
16698 if Etype (Prev) /= Prev then
16699
16700 -- Prev is a private subtype or a derived type, and needs
16701 -- no completion.
16702
16703 Error_Msg_NE ("invalid redeclaration of }", Id, Prev);
16704 New_Id := Id;
16705
16706 elsif Ekind (Prev) = E_Private_Type
16707 and then Nkind_In (N, N_Task_Type_Declaration,
16708 N_Protected_Type_Declaration)
16709 then
16710 Error_Msg_N
16711 ("completion of nonlimited type cannot be limited", N);
16712
16713 elsif Ekind (Prev) = E_Record_Type_With_Private
16714 and then Nkind_In (N, N_Task_Type_Declaration,
16715 N_Protected_Type_Declaration)
16716 then
16717 if not Is_Limited_Record (Prev) then
16718 Error_Msg_N
16719 ("completion of nonlimited type cannot be limited", N);
16720
16721 elsif No (Interface_List (N)) then
16722 Error_Msg_N
16723 ("completion of tagged private type must be tagged",
16724 N);
16725 end if;
16726 end if;
16727
16728 -- Ada 2005 (AI-251): Private extension declaration of a task
16729 -- type or a protected type. This case arises when covering
16730 -- interface types.
16731
16732 elsif Nkind_In (N, N_Task_Type_Declaration,
16733 N_Protected_Type_Declaration)
16734 then
16735 null;
16736
16737 elsif Nkind (N) /= N_Full_Type_Declaration
16738 or else Nkind (Type_Definition (N)) /= N_Derived_Type_Definition
16739 then
16740 Error_Msg_N
16741 ("full view of private extension must be an extension", N);
16742
16743 elsif not (Abstract_Present (Parent (Prev)))
16744 and then Abstract_Present (Type_Definition (N))
16745 then
16746 Error_Msg_N
16747 ("full view of non-abstract extension cannot be abstract", N);
16748 end if;
16749
16750 if not In_Private_Part (Current_Scope) then
16751 Error_Msg_N
16752 ("declaration of full view must appear in private part", N);
16753 end if;
16754
16755 if Ada_Version >= Ada_2012 then
16756 Check_Duplicate_Aspects;
16757 end if;
16758
16759 Copy_And_Swap (Prev, Id);
16760 Set_Has_Private_Declaration (Prev);
16761 Set_Has_Private_Declaration (Id);
16762
16763 -- AI12-0133: Indicate whether we have a partial view with
16764 -- unknown discriminants, in which case initialization of objects
16765 -- of the type do not receive an invariant check.
16766
16767 Set_Partial_View_Has_Unknown_Discr
16768 (Prev, Has_Unknown_Discriminants (Id));
16769
16770 -- Preserve aspect and iterator flags that may have been set on
16771 -- the partial view.
16772
16773 Set_Has_Delayed_Aspects (Prev, Has_Delayed_Aspects (Id));
16774 Set_Has_Implicit_Dereference (Prev, Has_Implicit_Dereference (Id));
16775
16776 -- If no error, propagate freeze_node from private to full view.
16777 -- It may have been generated for an early operational item.
16778
16779 if Present (Freeze_Node (Id))
16780 and then Serious_Errors_Detected = 0
16781 and then No (Full_View (Id))
16782 then
16783 Set_Freeze_Node (Prev, Freeze_Node (Id));
16784 Set_Freeze_Node (Id, Empty);
16785 Set_First_Rep_Item (Prev, First_Rep_Item (Id));
16786 end if;
16787
16788 Set_Full_View (Id, Prev);
16789 New_Id := Prev;
16790 end if;
16791
16792 -- Verify that full declaration conforms to partial one
16793
16794 if Is_Incomplete_Or_Private_Type (Prev)
16795 and then Present (Discriminant_Specifications (Prev_Par))
16796 then
16797 if Present (Discriminant_Specifications (N)) then
16798 if Ekind (Prev) = E_Incomplete_Type then
16799 Check_Discriminant_Conformance (N, Prev, Prev);
16800 else
16801 Check_Discriminant_Conformance (N, Prev, Id);
16802 end if;
16803
16804 else
16805 Error_Msg_N
16806 ("missing discriminants in full type declaration", N);
16807
16808 -- To avoid cascaded errors on subsequent use, share the
16809 -- discriminants of the partial view.
16810
16811 Set_Discriminant_Specifications (N,
16812 Discriminant_Specifications (Prev_Par));
16813 end if;
16814 end if;
16815
16816 -- A prior untagged partial view can have an associated class-wide
16817 -- type due to use of the class attribute, and in this case the full
16818 -- type must also be tagged. This Ada 95 usage is deprecated in favor
16819 -- of incomplete tagged declarations, but we check for it.
16820
16821 if Is_Type (Prev)
16822 and then (Is_Tagged_Type (Prev)
16823 or else Present (Class_Wide_Type (Prev)))
16824 then
16825 -- Ada 2012 (AI05-0162): A private type may be the completion of
16826 -- an incomplete type.
16827
16828 if Ada_Version >= Ada_2012
16829 and then Is_Incomplete_Type (Prev)
16830 and then Nkind_In (N, N_Private_Type_Declaration,
16831 N_Private_Extension_Declaration)
16832 then
16833 -- No need to check private extensions since they are tagged
16834
16835 if Nkind (N) = N_Private_Type_Declaration
16836 and then not Tagged_Present (N)
16837 then
16838 Tag_Mismatch;
16839 end if;
16840
16841 -- The full declaration is either a tagged type (including
16842 -- a synchronized type that implements interfaces) or a
16843 -- type extension, otherwise this is an error.
16844
16845 elsif Nkind_In (N, N_Task_Type_Declaration,
16846 N_Protected_Type_Declaration)
16847 then
16848 if No (Interface_List (N)) and then not Error_Posted (N) then
16849 Tag_Mismatch;
16850 end if;
16851
16852 elsif Nkind (Type_Definition (N)) = N_Record_Definition then
16853
16854 -- Indicate that the previous declaration (tagged incomplete
16855 -- or private declaration) requires the same on the full one.
16856
16857 if not Tagged_Present (Type_Definition (N)) then
16858 Tag_Mismatch;
16859 Set_Is_Tagged_Type (Id);
16860 end if;
16861
16862 elsif Nkind (Type_Definition (N)) = N_Derived_Type_Definition then
16863 if No (Record_Extension_Part (Type_Definition (N))) then
16864 Error_Msg_NE
16865 ("full declaration of } must be a record extension",
16866 Prev, Id);
16867
16868 -- Set some attributes to produce a usable full view
16869
16870 Set_Is_Tagged_Type (Id);
16871 end if;
16872
16873 else
16874 Tag_Mismatch;
16875 end if;
16876 end if;
16877
16878 if Present (Prev)
16879 and then Nkind (Parent (Prev)) = N_Incomplete_Type_Declaration
16880 and then Present (Premature_Use (Parent (Prev)))
16881 then
16882 Error_Msg_Sloc := Sloc (N);
16883 Error_Msg_N
16884 ("\full declaration #", Premature_Use (Parent (Prev)));
16885 end if;
16886
16887 return New_Id;
16888 end if;
16889 end Find_Type_Name;
16890
16891 -------------------------
16892 -- Find_Type_Of_Object --
16893 -------------------------
16894
16895 function Find_Type_Of_Object
16896 (Obj_Def : Node_Id;
16897 Related_Nod : Node_Id) return Entity_Id
16898 is
16899 Def_Kind : constant Node_Kind := Nkind (Obj_Def);
16900 P : Node_Id := Parent (Obj_Def);
16901 T : Entity_Id;
16902 Nam : Name_Id;
16903
16904 begin
16905 -- If the parent is a component_definition node we climb to the
16906 -- component_declaration node
16907
16908 if Nkind (P) = N_Component_Definition then
16909 P := Parent (P);
16910 end if;
16911
16912 -- Case of an anonymous array subtype
16913
16914 if Nkind_In (Def_Kind, N_Constrained_Array_Definition,
16915 N_Unconstrained_Array_Definition)
16916 then
16917 T := Empty;
16918 Array_Type_Declaration (T, Obj_Def);
16919
16920 -- Create an explicit subtype whenever possible
16921
16922 elsif Nkind (P) /= N_Component_Declaration
16923 and then Def_Kind = N_Subtype_Indication
16924 then
16925 -- Base name of subtype on object name, which will be unique in
16926 -- the current scope.
16927
16928 -- If this is a duplicate declaration, return base type, to avoid
16929 -- generating duplicate anonymous types.
16930
16931 if Error_Posted (P) then
16932 Analyze (Subtype_Mark (Obj_Def));
16933 return Entity (Subtype_Mark (Obj_Def));
16934 end if;
16935
16936 Nam :=
16937 New_External_Name
16938 (Chars (Defining_Identifier (Related_Nod)), 'S', 0, 'T');
16939
16940 T := Make_Defining_Identifier (Sloc (P), Nam);
16941
16942 Insert_Action (Obj_Def,
16943 Make_Subtype_Declaration (Sloc (P),
16944 Defining_Identifier => T,
16945 Subtype_Indication => Relocate_Node (Obj_Def)));
16946
16947 -- This subtype may need freezing, and this will not be done
16948 -- automatically if the object declaration is not in declarative
16949 -- part. Since this is an object declaration, the type cannot always
16950 -- be frozen here. Deferred constants do not freeze their type
16951 -- (which often enough will be private).
16952
16953 if Nkind (P) = N_Object_Declaration
16954 and then Constant_Present (P)
16955 and then No (Expression (P))
16956 then
16957 null;
16958
16959 -- Here we freeze the base type of object type to catch premature use
16960 -- of discriminated private type without a full view.
16961
16962 else
16963 Insert_Actions (Obj_Def, Freeze_Entity (Base_Type (T), P));
16964 end if;
16965
16966 -- Ada 2005 AI-406: the object definition in an object declaration
16967 -- can be an access definition.
16968
16969 elsif Def_Kind = N_Access_Definition then
16970 T := Access_Definition (Related_Nod, Obj_Def);
16971
16972 Set_Is_Local_Anonymous_Access
16973 (T,
16974 V => (Ada_Version < Ada_2012)
16975 or else (Nkind (P) /= N_Object_Declaration)
16976 or else Is_Library_Level_Entity (Defining_Identifier (P)));
16977
16978 -- Otherwise, the object definition is just a subtype_mark
16979
16980 else
16981 T := Process_Subtype (Obj_Def, Related_Nod);
16982
16983 -- If expansion is disabled an object definition that is an aggregate
16984 -- will not get expanded and may lead to scoping problems in the back
16985 -- end, if the object is referenced in an inner scope. In that case
16986 -- create an itype reference for the object definition now. This
16987 -- may be redundant in some cases, but harmless.
16988
16989 if Is_Itype (T)
16990 and then Nkind (Related_Nod) = N_Object_Declaration
16991 and then ASIS_Mode
16992 then
16993 Build_Itype_Reference (T, Related_Nod);
16994 end if;
16995 end if;
16996
16997 return T;
16998 end Find_Type_Of_Object;
16999
17000 --------------------------------
17001 -- Find_Type_Of_Subtype_Indic --
17002 --------------------------------
17003
17004 function Find_Type_Of_Subtype_Indic (S : Node_Id) return Entity_Id is
17005 Typ : Entity_Id;
17006
17007 begin
17008 -- Case of subtype mark with a constraint
17009
17010 if Nkind (S) = N_Subtype_Indication then
17011 Find_Type (Subtype_Mark (S));
17012 Typ := Entity (Subtype_Mark (S));
17013
17014 if not
17015 Is_Valid_Constraint_Kind (Ekind (Typ), Nkind (Constraint (S)))
17016 then
17017 Error_Msg_N
17018 ("incorrect constraint for this kind of type", Constraint (S));
17019 Rewrite (S, New_Copy_Tree (Subtype_Mark (S)));
17020 end if;
17021
17022 -- Otherwise we have a subtype mark without a constraint
17023
17024 elsif Error_Posted (S) then
17025 Rewrite (S, New_Occurrence_Of (Any_Id, Sloc (S)));
17026 return Any_Type;
17027
17028 else
17029 Find_Type (S);
17030 Typ := Entity (S);
17031 end if;
17032
17033 -- Check No_Wide_Characters restriction
17034
17035 Check_Wide_Character_Restriction (Typ, S);
17036
17037 return Typ;
17038 end Find_Type_Of_Subtype_Indic;
17039
17040 -------------------------------------
17041 -- Floating_Point_Type_Declaration --
17042 -------------------------------------
17043
17044 procedure Floating_Point_Type_Declaration (T : Entity_Id; Def : Node_Id) is
17045 Digs : constant Node_Id := Digits_Expression (Def);
17046 Max_Digs_Val : constant Uint := Digits_Value (Standard_Long_Long_Float);
17047 Digs_Val : Uint;
17048 Base_Typ : Entity_Id;
17049 Implicit_Base : Entity_Id;
17050 Bound : Node_Id;
17051
17052 function Can_Derive_From (E : Entity_Id) return Boolean;
17053 -- Find if given digits value, and possibly a specified range, allows
17054 -- derivation from specified type
17055
17056 function Find_Base_Type return Entity_Id;
17057 -- Find a predefined base type that Def can derive from, or generate
17058 -- an error and substitute Long_Long_Float if none exists.
17059
17060 ---------------------
17061 -- Can_Derive_From --
17062 ---------------------
17063
17064 function Can_Derive_From (E : Entity_Id) return Boolean is
17065 Spec : constant Entity_Id := Real_Range_Specification (Def);
17066
17067 begin
17068 -- Check specified "digits" constraint
17069
17070 if Digs_Val > Digits_Value (E) then
17071 return False;
17072 end if;
17073
17074 -- Check for matching range, if specified
17075
17076 if Present (Spec) then
17077 if Expr_Value_R (Type_Low_Bound (E)) >
17078 Expr_Value_R (Low_Bound (Spec))
17079 then
17080 return False;
17081 end if;
17082
17083 if Expr_Value_R (Type_High_Bound (E)) <
17084 Expr_Value_R (High_Bound (Spec))
17085 then
17086 return False;
17087 end if;
17088 end if;
17089
17090 return True;
17091 end Can_Derive_From;
17092
17093 --------------------
17094 -- Find_Base_Type --
17095 --------------------
17096
17097 function Find_Base_Type return Entity_Id is
17098 Choice : Elmt_Id := First_Elmt (Predefined_Float_Types);
17099
17100 begin
17101 -- Iterate over the predefined types in order, returning the first
17102 -- one that Def can derive from.
17103
17104 while Present (Choice) loop
17105 if Can_Derive_From (Node (Choice)) then
17106 return Node (Choice);
17107 end if;
17108
17109 Next_Elmt (Choice);
17110 end loop;
17111
17112 -- If we can't derive from any existing type, use Long_Long_Float
17113 -- and give appropriate message explaining the problem.
17114
17115 if Digs_Val > Max_Digs_Val then
17116 -- It might be the case that there is a type with the requested
17117 -- range, just not the combination of digits and range.
17118
17119 Error_Msg_N
17120 ("no predefined type has requested range and precision",
17121 Real_Range_Specification (Def));
17122
17123 else
17124 Error_Msg_N
17125 ("range too large for any predefined type",
17126 Real_Range_Specification (Def));
17127 end if;
17128
17129 return Standard_Long_Long_Float;
17130 end Find_Base_Type;
17131
17132 -- Start of processing for Floating_Point_Type_Declaration
17133
17134 begin
17135 Check_Restriction (No_Floating_Point, Def);
17136
17137 -- Create an implicit base type
17138
17139 Implicit_Base :=
17140 Create_Itype (E_Floating_Point_Type, Parent (Def), T, 'B');
17141
17142 -- Analyze and verify digits value
17143
17144 Analyze_And_Resolve (Digs, Any_Integer);
17145 Check_Digits_Expression (Digs);
17146 Digs_Val := Expr_Value (Digs);
17147
17148 -- Process possible range spec and find correct type to derive from
17149
17150 Process_Real_Range_Specification (Def);
17151
17152 -- Check that requested number of digits is not too high.
17153
17154 if Digs_Val > Max_Digs_Val then
17155
17156 -- The check for Max_Base_Digits may be somewhat expensive, as it
17157 -- requires reading System, so only do it when necessary.
17158
17159 declare
17160 Max_Base_Digits : constant Uint :=
17161 Expr_Value
17162 (Expression
17163 (Parent (RTE (RE_Max_Base_Digits))));
17164
17165 begin
17166 if Digs_Val > Max_Base_Digits then
17167 Error_Msg_Uint_1 := Max_Base_Digits;
17168 Error_Msg_N ("digits value out of range, maximum is ^", Digs);
17169
17170 elsif No (Real_Range_Specification (Def)) then
17171 Error_Msg_Uint_1 := Max_Digs_Val;
17172 Error_Msg_N ("types with more than ^ digits need range spec "
17173 & "(RM 3.5.7(6))", Digs);
17174 end if;
17175 end;
17176 end if;
17177
17178 -- Find a suitable type to derive from or complain and use a substitute
17179
17180 Base_Typ := Find_Base_Type;
17181
17182 -- If there are bounds given in the declaration use them as the bounds
17183 -- of the type, otherwise use the bounds of the predefined base type
17184 -- that was chosen based on the Digits value.
17185
17186 if Present (Real_Range_Specification (Def)) then
17187 Set_Scalar_Range (T, Real_Range_Specification (Def));
17188 Set_Is_Constrained (T);
17189
17190 -- The bounds of this range must be converted to machine numbers
17191 -- in accordance with RM 4.9(38).
17192
17193 Bound := Type_Low_Bound (T);
17194
17195 if Nkind (Bound) = N_Real_Literal then
17196 Set_Realval
17197 (Bound, Machine (Base_Typ, Realval (Bound), Round, Bound));
17198 Set_Is_Machine_Number (Bound);
17199 end if;
17200
17201 Bound := Type_High_Bound (T);
17202
17203 if Nkind (Bound) = N_Real_Literal then
17204 Set_Realval
17205 (Bound, Machine (Base_Typ, Realval (Bound), Round, Bound));
17206 Set_Is_Machine_Number (Bound);
17207 end if;
17208
17209 else
17210 Set_Scalar_Range (T, Scalar_Range (Base_Typ));
17211 end if;
17212
17213 -- Complete definition of implicit base and declared first subtype. The
17214 -- inheritance of the rep item chain ensures that SPARK-related pragmas
17215 -- are not clobbered when the floating point type acts as a full view of
17216 -- a private type.
17217
17218 Set_Etype (Implicit_Base, Base_Typ);
17219 Set_Scalar_Range (Implicit_Base, Scalar_Range (Base_Typ));
17220 Set_Size_Info (Implicit_Base, Base_Typ);
17221 Set_RM_Size (Implicit_Base, RM_Size (Base_Typ));
17222 Set_First_Rep_Item (Implicit_Base, First_Rep_Item (Base_Typ));
17223 Set_Digits_Value (Implicit_Base, Digits_Value (Base_Typ));
17224 Set_Float_Rep (Implicit_Base, Float_Rep (Base_Typ));
17225
17226 Set_Ekind (T, E_Floating_Point_Subtype);
17227 Set_Etype (T, Implicit_Base);
17228 Set_Size_Info (T, Implicit_Base);
17229 Set_RM_Size (T, RM_Size (Implicit_Base));
17230 Inherit_Rep_Item_Chain (T, Implicit_Base);
17231 Set_Digits_Value (T, Digs_Val);
17232 end Floating_Point_Type_Declaration;
17233
17234 ----------------------------
17235 -- Get_Discriminant_Value --
17236 ----------------------------
17237
17238 -- This is the situation:
17239
17240 -- There is a non-derived type
17241
17242 -- type T0 (Dx, Dy, Dz...)
17243
17244 -- There are zero or more levels of derivation, with each derivation
17245 -- either purely inheriting the discriminants, or defining its own.
17246
17247 -- type Ti is new Ti-1
17248 -- or
17249 -- type Ti (Dw) is new Ti-1(Dw, 1, X+Y)
17250 -- or
17251 -- subtype Ti is ...
17252
17253 -- The subtype issue is avoided by the use of Original_Record_Component,
17254 -- and the fact that derived subtypes also derive the constraints.
17255
17256 -- This chain leads back from
17257
17258 -- Typ_For_Constraint
17259
17260 -- Typ_For_Constraint has discriminants, and the value for each
17261 -- discriminant is given by its corresponding Elmt of Constraints.
17262
17263 -- Discriminant is some discriminant in this hierarchy
17264
17265 -- We need to return its value
17266
17267 -- We do this by recursively searching each level, and looking for
17268 -- Discriminant. Once we get to the bottom, we start backing up
17269 -- returning the value for it which may in turn be a discriminant
17270 -- further up, so on the backup we continue the substitution.
17271
17272 function Get_Discriminant_Value
17273 (Discriminant : Entity_Id;
17274 Typ_For_Constraint : Entity_Id;
17275 Constraint : Elist_Id) return Node_Id
17276 is
17277 function Root_Corresponding_Discriminant
17278 (Discr : Entity_Id) return Entity_Id;
17279 -- Given a discriminant, traverse the chain of inherited discriminants
17280 -- and return the topmost discriminant.
17281
17282 function Search_Derivation_Levels
17283 (Ti : Entity_Id;
17284 Discrim_Values : Elist_Id;
17285 Stored_Discrim_Values : Boolean) return Node_Or_Entity_Id;
17286 -- This is the routine that performs the recursive search of levels
17287 -- as described above.
17288
17289 -------------------------------------
17290 -- Root_Corresponding_Discriminant --
17291 -------------------------------------
17292
17293 function Root_Corresponding_Discriminant
17294 (Discr : Entity_Id) return Entity_Id
17295 is
17296 D : Entity_Id;
17297
17298 begin
17299 D := Discr;
17300 while Present (Corresponding_Discriminant (D)) loop
17301 D := Corresponding_Discriminant (D);
17302 end loop;
17303
17304 return D;
17305 end Root_Corresponding_Discriminant;
17306
17307 ------------------------------
17308 -- Search_Derivation_Levels --
17309 ------------------------------
17310
17311 function Search_Derivation_Levels
17312 (Ti : Entity_Id;
17313 Discrim_Values : Elist_Id;
17314 Stored_Discrim_Values : Boolean) return Node_Or_Entity_Id
17315 is
17316 Assoc : Elmt_Id;
17317 Disc : Entity_Id;
17318 Result : Node_Or_Entity_Id;
17319 Result_Entity : Node_Id;
17320
17321 begin
17322 -- If inappropriate type, return Error, this happens only in
17323 -- cascaded error situations, and we want to avoid a blow up.
17324
17325 if not Is_Composite_Type (Ti) or else Is_Array_Type (Ti) then
17326 return Error;
17327 end if;
17328
17329 -- Look deeper if possible. Use Stored_Constraints only for
17330 -- untagged types. For tagged types use the given constraint.
17331 -- This asymmetry needs explanation???
17332
17333 if not Stored_Discrim_Values
17334 and then Present (Stored_Constraint (Ti))
17335 and then not Is_Tagged_Type (Ti)
17336 then
17337 Result :=
17338 Search_Derivation_Levels (Ti, Stored_Constraint (Ti), True);
17339 else
17340 declare
17341 Td : constant Entity_Id := Etype (Ti);
17342
17343 begin
17344 if Td = Ti then
17345 Result := Discriminant;
17346
17347 else
17348 if Present (Stored_Constraint (Ti)) then
17349 Result :=
17350 Search_Derivation_Levels
17351 (Td, Stored_Constraint (Ti), True);
17352 else
17353 Result :=
17354 Search_Derivation_Levels
17355 (Td, Discrim_Values, Stored_Discrim_Values);
17356 end if;
17357 end if;
17358 end;
17359 end if;
17360
17361 -- Extra underlying places to search, if not found above. For
17362 -- concurrent types, the relevant discriminant appears in the
17363 -- corresponding record. For a type derived from a private type
17364 -- without discriminant, the full view inherits the discriminants
17365 -- of the full view of the parent.
17366
17367 if Result = Discriminant then
17368 if Is_Concurrent_Type (Ti)
17369 and then Present (Corresponding_Record_Type (Ti))
17370 then
17371 Result :=
17372 Search_Derivation_Levels (
17373 Corresponding_Record_Type (Ti),
17374 Discrim_Values,
17375 Stored_Discrim_Values);
17376
17377 elsif Is_Private_Type (Ti)
17378 and then not Has_Discriminants (Ti)
17379 and then Present (Full_View (Ti))
17380 and then Etype (Full_View (Ti)) /= Ti
17381 then
17382 Result :=
17383 Search_Derivation_Levels (
17384 Full_View (Ti),
17385 Discrim_Values,
17386 Stored_Discrim_Values);
17387 end if;
17388 end if;
17389
17390 -- If Result is not a (reference to a) discriminant, return it,
17391 -- otherwise set Result_Entity to the discriminant.
17392
17393 if Nkind (Result) = N_Defining_Identifier then
17394 pragma Assert (Result = Discriminant);
17395 Result_Entity := Result;
17396
17397 else
17398 if not Denotes_Discriminant (Result) then
17399 return Result;
17400 end if;
17401
17402 Result_Entity := Entity (Result);
17403 end if;
17404
17405 -- See if this level of derivation actually has discriminants because
17406 -- tagged derivations can add them, hence the lower levels need not
17407 -- have any.
17408
17409 if not Has_Discriminants (Ti) then
17410 return Result;
17411 end if;
17412
17413 -- Scan Ti's discriminants for Result_Entity, and return its
17414 -- corresponding value, if any.
17415
17416 Result_Entity := Original_Record_Component (Result_Entity);
17417
17418 Assoc := First_Elmt (Discrim_Values);
17419
17420 if Stored_Discrim_Values then
17421 Disc := First_Stored_Discriminant (Ti);
17422 else
17423 Disc := First_Discriminant (Ti);
17424 end if;
17425
17426 while Present (Disc) loop
17427 pragma Assert (Present (Assoc));
17428
17429 if Original_Record_Component (Disc) = Result_Entity then
17430 return Node (Assoc);
17431 end if;
17432
17433 Next_Elmt (Assoc);
17434
17435 if Stored_Discrim_Values then
17436 Next_Stored_Discriminant (Disc);
17437 else
17438 Next_Discriminant (Disc);
17439 end if;
17440 end loop;
17441
17442 -- Could not find it
17443
17444 return Result;
17445 end Search_Derivation_Levels;
17446
17447 -- Local Variables
17448
17449 Result : Node_Or_Entity_Id;
17450
17451 -- Start of processing for Get_Discriminant_Value
17452
17453 begin
17454 -- ??? This routine is a gigantic mess and will be deleted. For the
17455 -- time being just test for the trivial case before calling recurse.
17456
17457 if Base_Type (Scope (Discriminant)) = Base_Type (Typ_For_Constraint) then
17458 declare
17459 D : Entity_Id;
17460 E : Elmt_Id;
17461
17462 begin
17463 D := First_Discriminant (Typ_For_Constraint);
17464 E := First_Elmt (Constraint);
17465 while Present (D) loop
17466 if Chars (D) = Chars (Discriminant) then
17467 return Node (E);
17468 end if;
17469
17470 Next_Discriminant (D);
17471 Next_Elmt (E);
17472 end loop;
17473 end;
17474 end if;
17475
17476 Result := Search_Derivation_Levels
17477 (Typ_For_Constraint, Constraint, False);
17478
17479 -- ??? hack to disappear when this routine is gone
17480
17481 if Nkind (Result) = N_Defining_Identifier then
17482 declare
17483 D : Entity_Id;
17484 E : Elmt_Id;
17485
17486 begin
17487 D := First_Discriminant (Typ_For_Constraint);
17488 E := First_Elmt (Constraint);
17489 while Present (D) loop
17490 if Root_Corresponding_Discriminant (D) = Discriminant then
17491 return Node (E);
17492 end if;
17493
17494 Next_Discriminant (D);
17495 Next_Elmt (E);
17496 end loop;
17497 end;
17498 end if;
17499
17500 pragma Assert (Nkind (Result) /= N_Defining_Identifier);
17501 return Result;
17502 end Get_Discriminant_Value;
17503
17504 --------------------------
17505 -- Has_Range_Constraint --
17506 --------------------------
17507
17508 function Has_Range_Constraint (N : Node_Id) return Boolean is
17509 C : constant Node_Id := Constraint (N);
17510
17511 begin
17512 if Nkind (C) = N_Range_Constraint then
17513 return True;
17514
17515 elsif Nkind (C) = N_Digits_Constraint then
17516 return
17517 Is_Decimal_Fixed_Point_Type (Entity (Subtype_Mark (N)))
17518 or else Present (Range_Constraint (C));
17519
17520 elsif Nkind (C) = N_Delta_Constraint then
17521 return Present (Range_Constraint (C));
17522
17523 else
17524 return False;
17525 end if;
17526 end Has_Range_Constraint;
17527
17528 ------------------------
17529 -- Inherit_Components --
17530 ------------------------
17531
17532 function Inherit_Components
17533 (N : Node_Id;
17534 Parent_Base : Entity_Id;
17535 Derived_Base : Entity_Id;
17536 Is_Tagged : Boolean;
17537 Inherit_Discr : Boolean;
17538 Discs : Elist_Id) return Elist_Id
17539 is
17540 Assoc_List : constant Elist_Id := New_Elmt_List;
17541
17542 procedure Inherit_Component
17543 (Old_C : Entity_Id;
17544 Plain_Discrim : Boolean := False;
17545 Stored_Discrim : Boolean := False);
17546 -- Inherits component Old_C from Parent_Base to the Derived_Base. If
17547 -- Plain_Discrim is True, Old_C is a discriminant. If Stored_Discrim is
17548 -- True, Old_C is a stored discriminant. If they are both false then
17549 -- Old_C is a regular component.
17550
17551 -----------------------
17552 -- Inherit_Component --
17553 -----------------------
17554
17555 procedure Inherit_Component
17556 (Old_C : Entity_Id;
17557 Plain_Discrim : Boolean := False;
17558 Stored_Discrim : Boolean := False)
17559 is
17560 procedure Set_Anonymous_Type (Id : Entity_Id);
17561 -- Id denotes the entity of an access discriminant or anonymous
17562 -- access component. Set the type of Id to either the same type of
17563 -- Old_C or create a new one depending on whether the parent and
17564 -- the child types are in the same scope.
17565
17566 ------------------------
17567 -- Set_Anonymous_Type --
17568 ------------------------
17569
17570 procedure Set_Anonymous_Type (Id : Entity_Id) is
17571 Old_Typ : constant Entity_Id := Etype (Old_C);
17572
17573 begin
17574 if Scope (Parent_Base) = Scope (Derived_Base) then
17575 Set_Etype (Id, Old_Typ);
17576
17577 -- The parent and the derived type are in two different scopes.
17578 -- Reuse the type of the original discriminant / component by
17579 -- copying it in order to preserve all attributes.
17580
17581 else
17582 declare
17583 Typ : constant Entity_Id := New_Copy (Old_Typ);
17584
17585 begin
17586 Set_Etype (Id, Typ);
17587
17588 -- Since we do not generate component declarations for
17589 -- inherited components, associate the itype with the
17590 -- derived type.
17591
17592 Set_Associated_Node_For_Itype (Typ, Parent (Derived_Base));
17593 Set_Scope (Typ, Derived_Base);
17594 end;
17595 end if;
17596 end Set_Anonymous_Type;
17597
17598 -- Local variables and constants
17599
17600 New_C : constant Entity_Id := New_Copy (Old_C);
17601
17602 Corr_Discrim : Entity_Id;
17603 Discrim : Entity_Id;
17604
17605 -- Start of processing for Inherit_Component
17606
17607 begin
17608 pragma Assert (not Is_Tagged or not Stored_Discrim);
17609
17610 Set_Parent (New_C, Parent (Old_C));
17611
17612 -- Regular discriminants and components must be inserted in the scope
17613 -- of the Derived_Base. Do it here.
17614
17615 if not Stored_Discrim then
17616 Enter_Name (New_C);
17617 end if;
17618
17619 -- For tagged types the Original_Record_Component must point to
17620 -- whatever this field was pointing to in the parent type. This has
17621 -- already been achieved by the call to New_Copy above.
17622
17623 if not Is_Tagged then
17624 Set_Original_Record_Component (New_C, New_C);
17625 end if;
17626
17627 -- Set the proper type of an access discriminant
17628
17629 if Ekind (New_C) = E_Discriminant
17630 and then Ekind (Etype (New_C)) = E_Anonymous_Access_Type
17631 then
17632 Set_Anonymous_Type (New_C);
17633 end if;
17634
17635 -- If we have inherited a component then see if its Etype contains
17636 -- references to Parent_Base discriminants. In this case, replace
17637 -- these references with the constraints given in Discs. We do not
17638 -- do this for the partial view of private types because this is
17639 -- not needed (only the components of the full view will be used
17640 -- for code generation) and cause problem. We also avoid this
17641 -- transformation in some error situations.
17642
17643 if Ekind (New_C) = E_Component then
17644
17645 -- Set the proper type of an anonymous access component
17646
17647 if Ekind (Etype (New_C)) = E_Anonymous_Access_Type then
17648 Set_Anonymous_Type (New_C);
17649
17650 elsif (Is_Private_Type (Derived_Base)
17651 and then not Is_Generic_Type (Derived_Base))
17652 or else (Is_Empty_Elmt_List (Discs)
17653 and then not Expander_Active)
17654 then
17655 Set_Etype (New_C, Etype (Old_C));
17656
17657 else
17658 -- The current component introduces a circularity of the
17659 -- following kind:
17660
17661 -- limited with Pack_2;
17662 -- package Pack_1 is
17663 -- type T_1 is tagged record
17664 -- Comp : access Pack_2.T_2;
17665 -- ...
17666 -- end record;
17667 -- end Pack_1;
17668
17669 -- with Pack_1;
17670 -- package Pack_2 is
17671 -- type T_2 is new Pack_1.T_1 with ...;
17672 -- end Pack_2;
17673
17674 Set_Etype
17675 (New_C,
17676 Constrain_Component_Type
17677 (Old_C, Derived_Base, N, Parent_Base, Discs));
17678 end if;
17679 end if;
17680
17681 -- In derived tagged types it is illegal to reference a non
17682 -- discriminant component in the parent type. To catch this, mark
17683 -- these components with an Ekind of E_Void. This will be reset in
17684 -- Record_Type_Definition after processing the record extension of
17685 -- the derived type.
17686
17687 -- If the declaration is a private extension, there is no further
17688 -- record extension to process, and the components retain their
17689 -- current kind, because they are visible at this point.
17690
17691 if Is_Tagged and then Ekind (New_C) = E_Component
17692 and then Nkind (N) /= N_Private_Extension_Declaration
17693 then
17694 Set_Ekind (New_C, E_Void);
17695 end if;
17696
17697 if Plain_Discrim then
17698 Set_Corresponding_Discriminant (New_C, Old_C);
17699 Build_Discriminal (New_C);
17700
17701 -- If we are explicitly inheriting a stored discriminant it will be
17702 -- completely hidden.
17703
17704 elsif Stored_Discrim then
17705 Set_Corresponding_Discriminant (New_C, Empty);
17706 Set_Discriminal (New_C, Empty);
17707 Set_Is_Completely_Hidden (New_C);
17708
17709 -- Set the Original_Record_Component of each discriminant in the
17710 -- derived base to point to the corresponding stored that we just
17711 -- created.
17712
17713 Discrim := First_Discriminant (Derived_Base);
17714 while Present (Discrim) loop
17715 Corr_Discrim := Corresponding_Discriminant (Discrim);
17716
17717 -- Corr_Discrim could be missing in an error situation
17718
17719 if Present (Corr_Discrim)
17720 and then Original_Record_Component (Corr_Discrim) = Old_C
17721 then
17722 Set_Original_Record_Component (Discrim, New_C);
17723 end if;
17724
17725 Next_Discriminant (Discrim);
17726 end loop;
17727
17728 Append_Entity (New_C, Derived_Base);
17729 end if;
17730
17731 if not Is_Tagged then
17732 Append_Elmt (Old_C, Assoc_List);
17733 Append_Elmt (New_C, Assoc_List);
17734 end if;
17735 end Inherit_Component;
17736
17737 -- Variables local to Inherit_Component
17738
17739 Loc : constant Source_Ptr := Sloc (N);
17740
17741 Parent_Discrim : Entity_Id;
17742 Stored_Discrim : Entity_Id;
17743 D : Entity_Id;
17744 Component : Entity_Id;
17745
17746 -- Start of processing for Inherit_Components
17747
17748 begin
17749 if not Is_Tagged then
17750 Append_Elmt (Parent_Base, Assoc_List);
17751 Append_Elmt (Derived_Base, Assoc_List);
17752 end if;
17753
17754 -- Inherit parent discriminants if needed
17755
17756 if Inherit_Discr then
17757 Parent_Discrim := First_Discriminant (Parent_Base);
17758 while Present (Parent_Discrim) loop
17759 Inherit_Component (Parent_Discrim, Plain_Discrim => True);
17760 Next_Discriminant (Parent_Discrim);
17761 end loop;
17762 end if;
17763
17764 -- Create explicit stored discrims for untagged types when necessary
17765
17766 if not Has_Unknown_Discriminants (Derived_Base)
17767 and then Has_Discriminants (Parent_Base)
17768 and then not Is_Tagged
17769 and then
17770 (not Inherit_Discr
17771 or else First_Discriminant (Parent_Base) /=
17772 First_Stored_Discriminant (Parent_Base))
17773 then
17774 Stored_Discrim := First_Stored_Discriminant (Parent_Base);
17775 while Present (Stored_Discrim) loop
17776 Inherit_Component (Stored_Discrim, Stored_Discrim => True);
17777 Next_Stored_Discriminant (Stored_Discrim);
17778 end loop;
17779 end if;
17780
17781 -- See if we can apply the second transformation for derived types, as
17782 -- explained in point 6. in the comments above Build_Derived_Record_Type
17783 -- This is achieved by appending Derived_Base discriminants into Discs,
17784 -- which has the side effect of returning a non empty Discs list to the
17785 -- caller of Inherit_Components, which is what we want. This must be
17786 -- done for private derived types if there are explicit stored
17787 -- discriminants, to ensure that we can retrieve the values of the
17788 -- constraints provided in the ancestors.
17789
17790 if Inherit_Discr
17791 and then Is_Empty_Elmt_List (Discs)
17792 and then Present (First_Discriminant (Derived_Base))
17793 and then
17794 (not Is_Private_Type (Derived_Base)
17795 or else Is_Completely_Hidden
17796 (First_Stored_Discriminant (Derived_Base))
17797 or else Is_Generic_Type (Derived_Base))
17798 then
17799 D := First_Discriminant (Derived_Base);
17800 while Present (D) loop
17801 Append_Elmt (New_Occurrence_Of (D, Loc), Discs);
17802 Next_Discriminant (D);
17803 end loop;
17804 end if;
17805
17806 -- Finally, inherit non-discriminant components unless they are not
17807 -- visible because defined or inherited from the full view of the
17808 -- parent. Don't inherit the _parent field of the parent type.
17809
17810 Component := First_Entity (Parent_Base);
17811 while Present (Component) loop
17812
17813 -- Ada 2005 (AI-251): Do not inherit components associated with
17814 -- secondary tags of the parent.
17815
17816 if Ekind (Component) = E_Component
17817 and then Present (Related_Type (Component))
17818 then
17819 null;
17820
17821 elsif Ekind (Component) /= E_Component
17822 or else Chars (Component) = Name_uParent
17823 then
17824 null;
17825
17826 -- If the derived type is within the parent type's declarative
17827 -- region, then the components can still be inherited even though
17828 -- they aren't visible at this point. This can occur for cases
17829 -- such as within public child units where the components must
17830 -- become visible upon entering the child unit's private part.
17831
17832 elsif not Is_Visible_Component (Component)
17833 and then not In_Open_Scopes (Scope (Parent_Base))
17834 then
17835 null;
17836
17837 elsif Ekind_In (Derived_Base, E_Private_Type,
17838 E_Limited_Private_Type)
17839 then
17840 null;
17841
17842 else
17843 Inherit_Component (Component);
17844 end if;
17845
17846 Next_Entity (Component);
17847 end loop;
17848
17849 -- For tagged derived types, inherited discriminants cannot be used in
17850 -- component declarations of the record extension part. To achieve this
17851 -- we mark the inherited discriminants as not visible.
17852
17853 if Is_Tagged and then Inherit_Discr then
17854 D := First_Discriminant (Derived_Base);
17855 while Present (D) loop
17856 Set_Is_Immediately_Visible (D, False);
17857 Next_Discriminant (D);
17858 end loop;
17859 end if;
17860
17861 return Assoc_List;
17862 end Inherit_Components;
17863
17864 -----------------------------
17865 -- Inherit_Predicate_Flags --
17866 -----------------------------
17867
17868 procedure Inherit_Predicate_Flags (Subt, Par : Entity_Id) is
17869 begin
17870 Set_Has_Predicates (Subt, Has_Predicates (Par));
17871 Set_Has_Static_Predicate_Aspect
17872 (Subt, Has_Static_Predicate_Aspect (Par));
17873 Set_Has_Dynamic_Predicate_Aspect
17874 (Subt, Has_Dynamic_Predicate_Aspect (Par));
17875 end Inherit_Predicate_Flags;
17876
17877 ----------------------
17878 -- Is_EVF_Procedure --
17879 ----------------------
17880
17881 function Is_EVF_Procedure (Subp : Entity_Id) return Boolean is
17882 Formal : Entity_Id;
17883
17884 begin
17885 -- Examine the formals of an Extensions_Visible False procedure looking
17886 -- for a controlling OUT parameter.
17887
17888 if Ekind (Subp) = E_Procedure
17889 and then Extensions_Visible_Status (Subp) = Extensions_Visible_False
17890 then
17891 Formal := First_Formal (Subp);
17892 while Present (Formal) loop
17893 if Ekind (Formal) = E_Out_Parameter
17894 and then Is_Controlling_Formal (Formal)
17895 then
17896 return True;
17897 end if;
17898
17899 Next_Formal (Formal);
17900 end loop;
17901 end if;
17902
17903 return False;
17904 end Is_EVF_Procedure;
17905
17906 -----------------------
17907 -- Is_Null_Extension --
17908 -----------------------
17909
17910 function Is_Null_Extension (T : Entity_Id) return Boolean is
17911 Type_Decl : constant Node_Id := Parent (Base_Type (T));
17912 Comp_List : Node_Id;
17913 Comp : Node_Id;
17914
17915 begin
17916 if Nkind (Type_Decl) /= N_Full_Type_Declaration
17917 or else not Is_Tagged_Type (T)
17918 or else Nkind (Type_Definition (Type_Decl)) /=
17919 N_Derived_Type_Definition
17920 or else No (Record_Extension_Part (Type_Definition (Type_Decl)))
17921 then
17922 return False;
17923 end if;
17924
17925 Comp_List :=
17926 Component_List (Record_Extension_Part (Type_Definition (Type_Decl)));
17927
17928 if Present (Discriminant_Specifications (Type_Decl)) then
17929 return False;
17930
17931 elsif Present (Comp_List)
17932 and then Is_Non_Empty_List (Component_Items (Comp_List))
17933 then
17934 Comp := First (Component_Items (Comp_List));
17935
17936 -- Only user-defined components are relevant. The component list
17937 -- may also contain a parent component and internal components
17938 -- corresponding to secondary tags, but these do not determine
17939 -- whether this is a null extension.
17940
17941 while Present (Comp) loop
17942 if Comes_From_Source (Comp) then
17943 return False;
17944 end if;
17945
17946 Next (Comp);
17947 end loop;
17948
17949 return True;
17950
17951 else
17952 return True;
17953 end if;
17954 end Is_Null_Extension;
17955
17956 ------------------------------
17957 -- Is_Valid_Constraint_Kind --
17958 ------------------------------
17959
17960 function Is_Valid_Constraint_Kind
17961 (T_Kind : Type_Kind;
17962 Constraint_Kind : Node_Kind) return Boolean
17963 is
17964 begin
17965 case T_Kind is
17966 when Enumeration_Kind |
17967 Integer_Kind =>
17968 return Constraint_Kind = N_Range_Constraint;
17969
17970 when Decimal_Fixed_Point_Kind =>
17971 return Nkind_In (Constraint_Kind, N_Digits_Constraint,
17972 N_Range_Constraint);
17973
17974 when Ordinary_Fixed_Point_Kind =>
17975 return Nkind_In (Constraint_Kind, N_Delta_Constraint,
17976 N_Range_Constraint);
17977
17978 when Float_Kind =>
17979 return Nkind_In (Constraint_Kind, N_Digits_Constraint,
17980 N_Range_Constraint);
17981
17982 when Access_Kind |
17983 Array_Kind |
17984 E_Record_Type |
17985 E_Record_Subtype |
17986 Class_Wide_Kind |
17987 E_Incomplete_Type |
17988 Private_Kind |
17989 Concurrent_Kind =>
17990 return Constraint_Kind = N_Index_Or_Discriminant_Constraint;
17991
17992 when others =>
17993 return True; -- Error will be detected later
17994 end case;
17995 end Is_Valid_Constraint_Kind;
17996
17997 --------------------------
17998 -- Is_Visible_Component --
17999 --------------------------
18000
18001 function Is_Visible_Component
18002 (C : Entity_Id;
18003 N : Node_Id := Empty) return Boolean
18004 is
18005 Original_Comp : Entity_Id := Empty;
18006 Original_Type : Entity_Id;
18007 Type_Scope : Entity_Id;
18008
18009 function Is_Local_Type (Typ : Entity_Id) return Boolean;
18010 -- Check whether parent type of inherited component is declared locally,
18011 -- possibly within a nested package or instance. The current scope is
18012 -- the derived record itself.
18013
18014 -------------------
18015 -- Is_Local_Type --
18016 -------------------
18017
18018 function Is_Local_Type (Typ : Entity_Id) return Boolean is
18019 Scop : Entity_Id;
18020
18021 begin
18022 Scop := Scope (Typ);
18023 while Present (Scop)
18024 and then Scop /= Standard_Standard
18025 loop
18026 if Scop = Scope (Current_Scope) then
18027 return True;
18028 end if;
18029
18030 Scop := Scope (Scop);
18031 end loop;
18032
18033 return False;
18034 end Is_Local_Type;
18035
18036 -- Start of processing for Is_Visible_Component
18037
18038 begin
18039 if Ekind_In (C, E_Component, E_Discriminant) then
18040 Original_Comp := Original_Record_Component (C);
18041 end if;
18042
18043 if No (Original_Comp) then
18044
18045 -- Premature usage, or previous error
18046
18047 return False;
18048
18049 else
18050 Original_Type := Scope (Original_Comp);
18051 Type_Scope := Scope (Base_Type (Scope (C)));
18052 end if;
18053
18054 -- This test only concerns tagged types
18055
18056 if not Is_Tagged_Type (Original_Type) then
18057 return True;
18058
18059 -- If it is _Parent or _Tag, there is no visibility issue
18060
18061 elsif not Comes_From_Source (Original_Comp) then
18062 return True;
18063
18064 -- Discriminants are visible unless the (private) type has unknown
18065 -- discriminants. If the discriminant reference is inserted for a
18066 -- discriminant check on a full view it is also visible.
18067
18068 elsif Ekind (Original_Comp) = E_Discriminant
18069 and then
18070 (not Has_Unknown_Discriminants (Original_Type)
18071 or else (Present (N)
18072 and then Nkind (N) = N_Selected_Component
18073 and then Nkind (Prefix (N)) = N_Type_Conversion
18074 and then not Comes_From_Source (Prefix (N))))
18075 then
18076 return True;
18077
18078 -- In the body of an instantiation, no need to check for the visibility
18079 -- of a component.
18080
18081 elsif In_Instance_Body then
18082 return True;
18083
18084 -- If the component has been declared in an ancestor which is currently
18085 -- a private type, then it is not visible. The same applies if the
18086 -- component's containing type is not in an open scope and the original
18087 -- component's enclosing type is a visible full view of a private type
18088 -- (which can occur in cases where an attempt is being made to reference
18089 -- a component in a sibling package that is inherited from a visible
18090 -- component of a type in an ancestor package; the component in the
18091 -- sibling package should not be visible even though the component it
18092 -- inherited from is visible). This does not apply however in the case
18093 -- where the scope of the type is a private child unit, or when the
18094 -- parent comes from a local package in which the ancestor is currently
18095 -- visible. The latter suppression of visibility is needed for cases
18096 -- that are tested in B730006.
18097
18098 elsif Is_Private_Type (Original_Type)
18099 or else
18100 (not Is_Private_Descendant (Type_Scope)
18101 and then not In_Open_Scopes (Type_Scope)
18102 and then Has_Private_Declaration (Original_Type))
18103 then
18104 -- If the type derives from an entity in a formal package, there
18105 -- are no additional visible components.
18106
18107 if Nkind (Original_Node (Unit_Declaration_Node (Type_Scope))) =
18108 N_Formal_Package_Declaration
18109 then
18110 return False;
18111
18112 -- if we are not in the private part of the current package, there
18113 -- are no additional visible components.
18114
18115 elsif Ekind (Scope (Current_Scope)) = E_Package
18116 and then not In_Private_Part (Scope (Current_Scope))
18117 then
18118 return False;
18119 else
18120 return
18121 Is_Child_Unit (Cunit_Entity (Current_Sem_Unit))
18122 and then In_Open_Scopes (Scope (Original_Type))
18123 and then Is_Local_Type (Type_Scope);
18124 end if;
18125
18126 -- There is another weird way in which a component may be invisible when
18127 -- the private and the full view are not derived from the same ancestor.
18128 -- Here is an example :
18129
18130 -- type A1 is tagged record F1 : integer; end record;
18131 -- type A2 is new A1 with record F2 : integer; end record;
18132 -- type T is new A1 with private;
18133 -- private
18134 -- type T is new A2 with null record;
18135
18136 -- In this case, the full view of T inherits F1 and F2 but the private
18137 -- view inherits only F1
18138
18139 else
18140 declare
18141 Ancestor : Entity_Id := Scope (C);
18142
18143 begin
18144 loop
18145 if Ancestor = Original_Type then
18146 return True;
18147
18148 -- The ancestor may have a partial view of the original type,
18149 -- but if the full view is in scope, as in a child body, the
18150 -- component is visible.
18151
18152 elsif In_Private_Part (Scope (Original_Type))
18153 and then Full_View (Ancestor) = Original_Type
18154 then
18155 return True;
18156
18157 elsif Ancestor = Etype (Ancestor) then
18158
18159 -- No further ancestors to examine
18160
18161 return False;
18162 end if;
18163
18164 Ancestor := Etype (Ancestor);
18165 end loop;
18166 end;
18167 end if;
18168 end Is_Visible_Component;
18169
18170 --------------------------
18171 -- Make_Class_Wide_Type --
18172 --------------------------
18173
18174 procedure Make_Class_Wide_Type (T : Entity_Id) is
18175 CW_Type : Entity_Id;
18176 CW_Name : Name_Id;
18177 Next_E : Entity_Id;
18178
18179 begin
18180 if Present (Class_Wide_Type (T)) then
18181
18182 -- The class-wide type is a partially decorated entity created for a
18183 -- unanalyzed tagged type referenced through a limited with clause.
18184 -- When the tagged type is analyzed, its class-wide type needs to be
18185 -- redecorated. Note that we reuse the entity created by Decorate_
18186 -- Tagged_Type in order to preserve all links.
18187
18188 if Materialize_Entity (Class_Wide_Type (T)) then
18189 CW_Type := Class_Wide_Type (T);
18190 Set_Materialize_Entity (CW_Type, False);
18191
18192 -- The class wide type can have been defined by the partial view, in
18193 -- which case everything is already done.
18194
18195 else
18196 return;
18197 end if;
18198
18199 -- Default case, we need to create a new class-wide type
18200
18201 else
18202 CW_Type :=
18203 New_External_Entity (E_Void, Scope (T), Sloc (T), T, 'C', 0, 'T');
18204 end if;
18205
18206 -- Inherit root type characteristics
18207
18208 CW_Name := Chars (CW_Type);
18209 Next_E := Next_Entity (CW_Type);
18210 Copy_Node (T, CW_Type);
18211 Set_Comes_From_Source (CW_Type, False);
18212 Set_Chars (CW_Type, CW_Name);
18213 Set_Parent (CW_Type, Parent (T));
18214 Set_Next_Entity (CW_Type, Next_E);
18215
18216 -- Ensure we have a new freeze node for the class-wide type. The partial
18217 -- view may have freeze action of its own, requiring a proper freeze
18218 -- node, and the same freeze node cannot be shared between the two
18219 -- types.
18220
18221 Set_Has_Delayed_Freeze (CW_Type);
18222 Set_Freeze_Node (CW_Type, Empty);
18223
18224 -- Customize the class-wide type: It has no prim. op., it cannot be
18225 -- abstract and its Etype points back to the specific root type.
18226
18227 Set_Ekind (CW_Type, E_Class_Wide_Type);
18228 Set_Is_Tagged_Type (CW_Type, True);
18229 Set_Direct_Primitive_Operations (CW_Type, New_Elmt_List);
18230 Set_Is_Abstract_Type (CW_Type, False);
18231 Set_Is_Constrained (CW_Type, False);
18232 Set_Is_First_Subtype (CW_Type, Is_First_Subtype (T));
18233 Set_Default_SSO (CW_Type);
18234
18235 if Ekind (T) = E_Class_Wide_Subtype then
18236 Set_Etype (CW_Type, Etype (Base_Type (T)));
18237 else
18238 Set_Etype (CW_Type, T);
18239 end if;
18240
18241 Set_No_Tagged_Streams_Pragma (CW_Type, No_Tagged_Streams);
18242
18243 -- If this is the class_wide type of a constrained subtype, it does
18244 -- not have discriminants.
18245
18246 Set_Has_Discriminants (CW_Type,
18247 Has_Discriminants (T) and then not Is_Constrained (T));
18248
18249 Set_Has_Unknown_Discriminants (CW_Type, True);
18250 Set_Class_Wide_Type (T, CW_Type);
18251 Set_Equivalent_Type (CW_Type, Empty);
18252
18253 -- The class-wide type of a class-wide type is itself (RM 3.9(14))
18254
18255 Set_Class_Wide_Type (CW_Type, CW_Type);
18256
18257 -- Inherit the "ghostness" from the root tagged type
18258
18259 if Ghost_Mode > None or else Is_Ghost_Entity (T) then
18260 Set_Is_Ghost_Entity (CW_Type);
18261 end if;
18262 end Make_Class_Wide_Type;
18263
18264 ----------------
18265 -- Make_Index --
18266 ----------------
18267
18268 procedure Make_Index
18269 (N : Node_Id;
18270 Related_Nod : Node_Id;
18271 Related_Id : Entity_Id := Empty;
18272 Suffix_Index : Nat := 1;
18273 In_Iter_Schm : Boolean := False)
18274 is
18275 R : Node_Id;
18276 T : Entity_Id;
18277 Def_Id : Entity_Id := Empty;
18278 Found : Boolean := False;
18279
18280 begin
18281 -- For a discrete range used in a constrained array definition and
18282 -- defined by a range, an implicit conversion to the predefined type
18283 -- INTEGER is assumed if each bound is either a numeric literal, a named
18284 -- number, or an attribute, and the type of both bounds (prior to the
18285 -- implicit conversion) is the type universal_integer. Otherwise, both
18286 -- bounds must be of the same discrete type, other than universal
18287 -- integer; this type must be determinable independently of the
18288 -- context, but using the fact that the type must be discrete and that
18289 -- both bounds must have the same type.
18290
18291 -- Character literals also have a universal type in the absence of
18292 -- of additional context, and are resolved to Standard_Character.
18293
18294 if Nkind (N) = N_Range then
18295
18296 -- The index is given by a range constraint. The bounds are known
18297 -- to be of a consistent type.
18298
18299 if not Is_Overloaded (N) then
18300 T := Etype (N);
18301
18302 -- For universal bounds, choose the specific predefined type
18303
18304 if T = Universal_Integer then
18305 T := Standard_Integer;
18306
18307 elsif T = Any_Character then
18308 Ambiguous_Character (Low_Bound (N));
18309
18310 T := Standard_Character;
18311 end if;
18312
18313 -- The node may be overloaded because some user-defined operators
18314 -- are available, but if a universal interpretation exists it is
18315 -- also the selected one.
18316
18317 elsif Universal_Interpretation (N) = Universal_Integer then
18318 T := Standard_Integer;
18319
18320 else
18321 T := Any_Type;
18322
18323 declare
18324 Ind : Interp_Index;
18325 It : Interp;
18326
18327 begin
18328 Get_First_Interp (N, Ind, It);
18329 while Present (It.Typ) loop
18330 if Is_Discrete_Type (It.Typ) then
18331
18332 if Found
18333 and then not Covers (It.Typ, T)
18334 and then not Covers (T, It.Typ)
18335 then
18336 Error_Msg_N ("ambiguous bounds in discrete range", N);
18337 exit;
18338 else
18339 T := It.Typ;
18340 Found := True;
18341 end if;
18342 end if;
18343
18344 Get_Next_Interp (Ind, It);
18345 end loop;
18346
18347 if T = Any_Type then
18348 Error_Msg_N ("discrete type required for range", N);
18349 Set_Etype (N, Any_Type);
18350 return;
18351
18352 elsif T = Universal_Integer then
18353 T := Standard_Integer;
18354 end if;
18355 end;
18356 end if;
18357
18358 if not Is_Discrete_Type (T) then
18359 Error_Msg_N ("discrete type required for range", N);
18360 Set_Etype (N, Any_Type);
18361 return;
18362 end if;
18363
18364 if Nkind (Low_Bound (N)) = N_Attribute_Reference
18365 and then Attribute_Name (Low_Bound (N)) = Name_First
18366 and then Is_Entity_Name (Prefix (Low_Bound (N)))
18367 and then Is_Type (Entity (Prefix (Low_Bound (N))))
18368 and then Is_Discrete_Type (Entity (Prefix (Low_Bound (N))))
18369 then
18370 -- The type of the index will be the type of the prefix, as long
18371 -- as the upper bound is 'Last of the same type.
18372
18373 Def_Id := Entity (Prefix (Low_Bound (N)));
18374
18375 if Nkind (High_Bound (N)) /= N_Attribute_Reference
18376 or else Attribute_Name (High_Bound (N)) /= Name_Last
18377 or else not Is_Entity_Name (Prefix (High_Bound (N)))
18378 or else Entity (Prefix (High_Bound (N))) /= Def_Id
18379 then
18380 Def_Id := Empty;
18381 end if;
18382 end if;
18383
18384 R := N;
18385 Process_Range_Expr_In_Decl (R, T, In_Iter_Schm => In_Iter_Schm);
18386
18387 elsif Nkind (N) = N_Subtype_Indication then
18388
18389 -- The index is given by a subtype with a range constraint
18390
18391 T := Base_Type (Entity (Subtype_Mark (N)));
18392
18393 if not Is_Discrete_Type (T) then
18394 Error_Msg_N ("discrete type required for range", N);
18395 Set_Etype (N, Any_Type);
18396 return;
18397 end if;
18398
18399 R := Range_Expression (Constraint (N));
18400
18401 Resolve (R, T);
18402 Process_Range_Expr_In_Decl
18403 (R, Entity (Subtype_Mark (N)), In_Iter_Schm => In_Iter_Schm);
18404
18405 elsif Nkind (N) = N_Attribute_Reference then
18406
18407 -- Catch beginner's error (use of attribute other than 'Range)
18408
18409 if Attribute_Name (N) /= Name_Range then
18410 Error_Msg_N ("expect attribute ''Range", N);
18411 Set_Etype (N, Any_Type);
18412 return;
18413 end if;
18414
18415 -- If the node denotes the range of a type mark, that is also the
18416 -- resulting type, and we do not need to create an Itype for it.
18417
18418 if Is_Entity_Name (Prefix (N))
18419 and then Comes_From_Source (N)
18420 and then Is_Type (Entity (Prefix (N)))
18421 and then Is_Discrete_Type (Entity (Prefix (N)))
18422 then
18423 Def_Id := Entity (Prefix (N));
18424 end if;
18425
18426 Analyze_And_Resolve (N);
18427 T := Etype (N);
18428 R := N;
18429
18430 -- If none of the above, must be a subtype. We convert this to a
18431 -- range attribute reference because in the case of declared first
18432 -- named subtypes, the types in the range reference can be different
18433 -- from the type of the entity. A range attribute normalizes the
18434 -- reference and obtains the correct types for the bounds.
18435
18436 -- This transformation is in the nature of an expansion, is only
18437 -- done if expansion is active. In particular, it is not done on
18438 -- formal generic types, because we need to retain the name of the
18439 -- original index for instantiation purposes.
18440
18441 else
18442 if not Is_Entity_Name (N) or else not Is_Type (Entity (N)) then
18443 Error_Msg_N ("invalid subtype mark in discrete range ", N);
18444 Set_Etype (N, Any_Integer);
18445 return;
18446
18447 else
18448 -- The type mark may be that of an incomplete type. It is only
18449 -- now that we can get the full view, previous analysis does
18450 -- not look specifically for a type mark.
18451
18452 Set_Entity (N, Get_Full_View (Entity (N)));
18453 Set_Etype (N, Entity (N));
18454 Def_Id := Entity (N);
18455
18456 if not Is_Discrete_Type (Def_Id) then
18457 Error_Msg_N ("discrete type required for index", N);
18458 Set_Etype (N, Any_Type);
18459 return;
18460 end if;
18461 end if;
18462
18463 if Expander_Active then
18464 Rewrite (N,
18465 Make_Attribute_Reference (Sloc (N),
18466 Attribute_Name => Name_Range,
18467 Prefix => Relocate_Node (N)));
18468
18469 -- The original was a subtype mark that does not freeze. This
18470 -- means that the rewritten version must not freeze either.
18471
18472 Set_Must_Not_Freeze (N);
18473 Set_Must_Not_Freeze (Prefix (N));
18474 Analyze_And_Resolve (N);
18475 T := Etype (N);
18476 R := N;
18477
18478 -- If expander is inactive, type is legal, nothing else to construct
18479
18480 else
18481 return;
18482 end if;
18483 end if;
18484
18485 if not Is_Discrete_Type (T) then
18486 Error_Msg_N ("discrete type required for range", N);
18487 Set_Etype (N, Any_Type);
18488 return;
18489
18490 elsif T = Any_Type then
18491 Set_Etype (N, Any_Type);
18492 return;
18493 end if;
18494
18495 -- We will now create the appropriate Itype to describe the range, but
18496 -- first a check. If we originally had a subtype, then we just label
18497 -- the range with this subtype. Not only is there no need to construct
18498 -- a new subtype, but it is wrong to do so for two reasons:
18499
18500 -- 1. A legality concern, if we have a subtype, it must not freeze,
18501 -- and the Itype would cause freezing incorrectly
18502
18503 -- 2. An efficiency concern, if we created an Itype, it would not be
18504 -- recognized as the same type for the purposes of eliminating
18505 -- checks in some circumstances.
18506
18507 -- We signal this case by setting the subtype entity in Def_Id
18508
18509 if No (Def_Id) then
18510 Def_Id :=
18511 Create_Itype (E_Void, Related_Nod, Related_Id, 'D', Suffix_Index);
18512 Set_Etype (Def_Id, Base_Type (T));
18513
18514 if Is_Signed_Integer_Type (T) then
18515 Set_Ekind (Def_Id, E_Signed_Integer_Subtype);
18516
18517 elsif Is_Modular_Integer_Type (T) then
18518 Set_Ekind (Def_Id, E_Modular_Integer_Subtype);
18519
18520 else
18521 Set_Ekind (Def_Id, E_Enumeration_Subtype);
18522 Set_Is_Character_Type (Def_Id, Is_Character_Type (T));
18523 Set_First_Literal (Def_Id, First_Literal (T));
18524 end if;
18525
18526 Set_Size_Info (Def_Id, (T));
18527 Set_RM_Size (Def_Id, RM_Size (T));
18528 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
18529
18530 Set_Scalar_Range (Def_Id, R);
18531 Conditional_Delay (Def_Id, T);
18532
18533 if Nkind (N) = N_Subtype_Indication then
18534 Inherit_Predicate_Flags (Def_Id, Entity (Subtype_Mark (N)));
18535 end if;
18536
18537 -- In the subtype indication case, if the immediate parent of the
18538 -- new subtype is non-static, then the subtype we create is non-
18539 -- static, even if its bounds are static.
18540
18541 if Nkind (N) = N_Subtype_Indication
18542 and then not Is_OK_Static_Subtype (Entity (Subtype_Mark (N)))
18543 then
18544 Set_Is_Non_Static_Subtype (Def_Id);
18545 end if;
18546 end if;
18547
18548 -- Final step is to label the index with this constructed type
18549
18550 Set_Etype (N, Def_Id);
18551 end Make_Index;
18552
18553 ------------------------------
18554 -- Modular_Type_Declaration --
18555 ------------------------------
18556
18557 procedure Modular_Type_Declaration (T : Entity_Id; Def : Node_Id) is
18558 Mod_Expr : constant Node_Id := Expression (Def);
18559 M_Val : Uint;
18560
18561 procedure Set_Modular_Size (Bits : Int);
18562 -- Sets RM_Size to Bits, and Esize to normal word size above this
18563
18564 ----------------------
18565 -- Set_Modular_Size --
18566 ----------------------
18567
18568 procedure Set_Modular_Size (Bits : Int) is
18569 begin
18570 Set_RM_Size (T, UI_From_Int (Bits));
18571
18572 if Bits <= 8 then
18573 Init_Esize (T, 8);
18574
18575 elsif Bits <= 16 then
18576 Init_Esize (T, 16);
18577
18578 elsif Bits <= 32 then
18579 Init_Esize (T, 32);
18580
18581 else
18582 Init_Esize (T, System_Max_Binary_Modulus_Power);
18583 end if;
18584
18585 if not Non_Binary_Modulus (T) and then Esize (T) = RM_Size (T) then
18586 Set_Is_Known_Valid (T);
18587 end if;
18588 end Set_Modular_Size;
18589
18590 -- Start of processing for Modular_Type_Declaration
18591
18592 begin
18593 -- If the mod expression is (exactly) 2 * literal, where literal is
18594 -- 64 or less,then almost certainly the * was meant to be **. Warn.
18595
18596 if Warn_On_Suspicious_Modulus_Value
18597 and then Nkind (Mod_Expr) = N_Op_Multiply
18598 and then Nkind (Left_Opnd (Mod_Expr)) = N_Integer_Literal
18599 and then Intval (Left_Opnd (Mod_Expr)) = Uint_2
18600 and then Nkind (Right_Opnd (Mod_Expr)) = N_Integer_Literal
18601 and then Intval (Right_Opnd (Mod_Expr)) <= Uint_64
18602 then
18603 Error_Msg_N
18604 ("suspicious MOD value, was '*'* intended'??M?", Mod_Expr);
18605 end if;
18606
18607 -- Proceed with analysis of mod expression
18608
18609 Analyze_And_Resolve (Mod_Expr, Any_Integer);
18610 Set_Etype (T, T);
18611 Set_Ekind (T, E_Modular_Integer_Type);
18612 Init_Alignment (T);
18613 Set_Is_Constrained (T);
18614
18615 if not Is_OK_Static_Expression (Mod_Expr) then
18616 Flag_Non_Static_Expr
18617 ("non-static expression used for modular type bound!", Mod_Expr);
18618 M_Val := 2 ** System_Max_Binary_Modulus_Power;
18619 else
18620 M_Val := Expr_Value (Mod_Expr);
18621 end if;
18622
18623 if M_Val < 1 then
18624 Error_Msg_N ("modulus value must be positive", Mod_Expr);
18625 M_Val := 2 ** System_Max_Binary_Modulus_Power;
18626 end if;
18627
18628 if M_Val > 2 ** Standard_Long_Integer_Size then
18629 Check_Restriction (No_Long_Long_Integers, Mod_Expr);
18630 end if;
18631
18632 Set_Modulus (T, M_Val);
18633
18634 -- Create bounds for the modular type based on the modulus given in
18635 -- the type declaration and then analyze and resolve those bounds.
18636
18637 Set_Scalar_Range (T,
18638 Make_Range (Sloc (Mod_Expr),
18639 Low_Bound => Make_Integer_Literal (Sloc (Mod_Expr), 0),
18640 High_Bound => Make_Integer_Literal (Sloc (Mod_Expr), M_Val - 1)));
18641
18642 -- Properly analyze the literals for the range. We do this manually
18643 -- because we can't go calling Resolve, since we are resolving these
18644 -- bounds with the type, and this type is certainly not complete yet.
18645
18646 Set_Etype (Low_Bound (Scalar_Range (T)), T);
18647 Set_Etype (High_Bound (Scalar_Range (T)), T);
18648 Set_Is_Static_Expression (Low_Bound (Scalar_Range (T)));
18649 Set_Is_Static_Expression (High_Bound (Scalar_Range (T)));
18650
18651 -- Loop through powers of two to find number of bits required
18652
18653 for Bits in Int range 0 .. System_Max_Binary_Modulus_Power loop
18654
18655 -- Binary case
18656
18657 if M_Val = 2 ** Bits then
18658 Set_Modular_Size (Bits);
18659 return;
18660
18661 -- Nonbinary case
18662
18663 elsif M_Val < 2 ** Bits then
18664 Check_SPARK_05_Restriction ("modulus should be a power of 2", T);
18665 Set_Non_Binary_Modulus (T);
18666
18667 if Bits > System_Max_Nonbinary_Modulus_Power then
18668 Error_Msg_Uint_1 :=
18669 UI_From_Int (System_Max_Nonbinary_Modulus_Power);
18670 Error_Msg_F
18671 ("nonbinary modulus exceeds limit (2 '*'*^ - 1)", Mod_Expr);
18672 Set_Modular_Size (System_Max_Binary_Modulus_Power);
18673 return;
18674
18675 else
18676 -- In the nonbinary case, set size as per RM 13.3(55)
18677
18678 Set_Modular_Size (Bits);
18679 return;
18680 end if;
18681 end if;
18682
18683 end loop;
18684
18685 -- If we fall through, then the size exceed System.Max_Binary_Modulus
18686 -- so we just signal an error and set the maximum size.
18687
18688 Error_Msg_Uint_1 := UI_From_Int (System_Max_Binary_Modulus_Power);
18689 Error_Msg_F ("modulus exceeds limit (2 '*'*^)", Mod_Expr);
18690
18691 Set_Modular_Size (System_Max_Binary_Modulus_Power);
18692 Init_Alignment (T);
18693
18694 end Modular_Type_Declaration;
18695
18696 --------------------------
18697 -- New_Concatenation_Op --
18698 --------------------------
18699
18700 procedure New_Concatenation_Op (Typ : Entity_Id) is
18701 Loc : constant Source_Ptr := Sloc (Typ);
18702 Op : Entity_Id;
18703
18704 function Make_Op_Formal (Typ, Op : Entity_Id) return Entity_Id;
18705 -- Create abbreviated declaration for the formal of a predefined
18706 -- Operator 'Op' of type 'Typ'
18707
18708 --------------------
18709 -- Make_Op_Formal --
18710 --------------------
18711
18712 function Make_Op_Formal (Typ, Op : Entity_Id) return Entity_Id is
18713 Formal : Entity_Id;
18714 begin
18715 Formal := New_Internal_Entity (E_In_Parameter, Op, Loc, 'P');
18716 Set_Etype (Formal, Typ);
18717 Set_Mechanism (Formal, Default_Mechanism);
18718 return Formal;
18719 end Make_Op_Formal;
18720
18721 -- Start of processing for New_Concatenation_Op
18722
18723 begin
18724 Op := Make_Defining_Operator_Symbol (Loc, Name_Op_Concat);
18725
18726 Set_Ekind (Op, E_Operator);
18727 Set_Scope (Op, Current_Scope);
18728 Set_Etype (Op, Typ);
18729 Set_Homonym (Op, Get_Name_Entity_Id (Name_Op_Concat));
18730 Set_Is_Immediately_Visible (Op);
18731 Set_Is_Intrinsic_Subprogram (Op);
18732 Set_Has_Completion (Op);
18733 Append_Entity (Op, Current_Scope);
18734
18735 Set_Name_Entity_Id (Name_Op_Concat, Op);
18736
18737 Append_Entity (Make_Op_Formal (Typ, Op), Op);
18738 Append_Entity (Make_Op_Formal (Typ, Op), Op);
18739 end New_Concatenation_Op;
18740
18741 -------------------------
18742 -- OK_For_Limited_Init --
18743 -------------------------
18744
18745 -- ???Check all calls of this, and compare the conditions under which it's
18746 -- called.
18747
18748 function OK_For_Limited_Init
18749 (Typ : Entity_Id;
18750 Exp : Node_Id) return Boolean
18751 is
18752 begin
18753 return Is_CPP_Constructor_Call (Exp)
18754 or else (Ada_Version >= Ada_2005
18755 and then not Debug_Flag_Dot_L
18756 and then OK_For_Limited_Init_In_05 (Typ, Exp));
18757 end OK_For_Limited_Init;
18758
18759 -------------------------------
18760 -- OK_For_Limited_Init_In_05 --
18761 -------------------------------
18762
18763 function OK_For_Limited_Init_In_05
18764 (Typ : Entity_Id;
18765 Exp : Node_Id) return Boolean
18766 is
18767 begin
18768 -- An object of a limited interface type can be initialized with any
18769 -- expression of a nonlimited descendant type. However this does not
18770 -- apply if this is a view conversion of some other expression. This
18771 -- is checked below.
18772
18773 if Is_Class_Wide_Type (Typ)
18774 and then Is_Limited_Interface (Typ)
18775 and then not Is_Limited_Type (Etype (Exp))
18776 and then Nkind (Exp) /= N_Type_Conversion
18777 then
18778 return True;
18779 end if;
18780
18781 -- Ada 2005 (AI-287, AI-318): Relax the strictness of the front end in
18782 -- case of limited aggregates (including extension aggregates), and
18783 -- function calls. The function call may have been given in prefixed
18784 -- notation, in which case the original node is an indexed component.
18785 -- If the function is parameterless, the original node was an explicit
18786 -- dereference. The function may also be parameterless, in which case
18787 -- the source node is just an identifier.
18788
18789 -- A branch of a conditional expression may have been removed if the
18790 -- condition is statically known. This happens during expansion, and
18791 -- thus will not happen if previous errors were encountered. The check
18792 -- will have been performed on the chosen branch, which replaces the
18793 -- original conditional expression.
18794
18795 if No (Exp) then
18796 return True;
18797 end if;
18798
18799 case Nkind (Original_Node (Exp)) is
18800 when N_Aggregate | N_Extension_Aggregate | N_Function_Call | N_Op =>
18801 return True;
18802
18803 when N_Identifier =>
18804 return Present (Entity (Original_Node (Exp)))
18805 and then Ekind (Entity (Original_Node (Exp))) = E_Function;
18806
18807 when N_Qualified_Expression =>
18808 return
18809 OK_For_Limited_Init_In_05
18810 (Typ, Expression (Original_Node (Exp)));
18811
18812 -- Ada 2005 (AI-251): If a class-wide interface object is initialized
18813 -- with a function call, the expander has rewritten the call into an
18814 -- N_Type_Conversion node to force displacement of the pointer to
18815 -- reference the component containing the secondary dispatch table.
18816 -- Otherwise a type conversion is not a legal context.
18817 -- A return statement for a build-in-place function returning a
18818 -- synchronized type also introduces an unchecked conversion.
18819
18820 when N_Type_Conversion |
18821 N_Unchecked_Type_Conversion =>
18822 return not Comes_From_Source (Exp)
18823 and then
18824 OK_For_Limited_Init_In_05
18825 (Typ, Expression (Original_Node (Exp)));
18826
18827 when N_Indexed_Component |
18828 N_Selected_Component |
18829 N_Explicit_Dereference =>
18830 return Nkind (Exp) = N_Function_Call;
18831
18832 -- A use of 'Input is a function call, hence allowed. Normally the
18833 -- attribute will be changed to a call, but the attribute by itself
18834 -- can occur with -gnatc.
18835
18836 when N_Attribute_Reference =>
18837 return Attribute_Name (Original_Node (Exp)) = Name_Input;
18838
18839 -- For a case expression, all dependent expressions must be legal
18840
18841 when N_Case_Expression =>
18842 declare
18843 Alt : Node_Id;
18844
18845 begin
18846 Alt := First (Alternatives (Original_Node (Exp)));
18847 while Present (Alt) loop
18848 if not OK_For_Limited_Init_In_05 (Typ, Expression (Alt)) then
18849 return False;
18850 end if;
18851
18852 Next (Alt);
18853 end loop;
18854
18855 return True;
18856 end;
18857
18858 -- For an if expression, all dependent expressions must be legal
18859
18860 when N_If_Expression =>
18861 declare
18862 Then_Expr : constant Node_Id :=
18863 Next (First (Expressions (Original_Node (Exp))));
18864 Else_Expr : constant Node_Id := Next (Then_Expr);
18865 begin
18866 return OK_For_Limited_Init_In_05 (Typ, Then_Expr)
18867 and then
18868 OK_For_Limited_Init_In_05 (Typ, Else_Expr);
18869 end;
18870
18871 when others =>
18872 return False;
18873 end case;
18874 end OK_For_Limited_Init_In_05;
18875
18876 -------------------------------------------
18877 -- Ordinary_Fixed_Point_Type_Declaration --
18878 -------------------------------------------
18879
18880 procedure Ordinary_Fixed_Point_Type_Declaration
18881 (T : Entity_Id;
18882 Def : Node_Id)
18883 is
18884 Loc : constant Source_Ptr := Sloc (Def);
18885 Delta_Expr : constant Node_Id := Delta_Expression (Def);
18886 RRS : constant Node_Id := Real_Range_Specification (Def);
18887 Implicit_Base : Entity_Id;
18888 Delta_Val : Ureal;
18889 Small_Val : Ureal;
18890 Low_Val : Ureal;
18891 High_Val : Ureal;
18892
18893 begin
18894 Check_Restriction (No_Fixed_Point, Def);
18895
18896 -- Create implicit base type
18897
18898 Implicit_Base :=
18899 Create_Itype (E_Ordinary_Fixed_Point_Type, Parent (Def), T, 'B');
18900 Set_Etype (Implicit_Base, Implicit_Base);
18901
18902 -- Analyze and process delta expression
18903
18904 Analyze_And_Resolve (Delta_Expr, Any_Real);
18905
18906 Check_Delta_Expression (Delta_Expr);
18907 Delta_Val := Expr_Value_R (Delta_Expr);
18908
18909 Set_Delta_Value (Implicit_Base, Delta_Val);
18910
18911 -- Compute default small from given delta, which is the largest power
18912 -- of two that does not exceed the given delta value.
18913
18914 declare
18915 Tmp : Ureal;
18916 Scale : Int;
18917
18918 begin
18919 Tmp := Ureal_1;
18920 Scale := 0;
18921
18922 if Delta_Val < Ureal_1 then
18923 while Delta_Val < Tmp loop
18924 Tmp := Tmp / Ureal_2;
18925 Scale := Scale + 1;
18926 end loop;
18927
18928 else
18929 loop
18930 Tmp := Tmp * Ureal_2;
18931 exit when Tmp > Delta_Val;
18932 Scale := Scale - 1;
18933 end loop;
18934 end if;
18935
18936 Small_Val := UR_From_Components (Uint_1, UI_From_Int (Scale), 2);
18937 end;
18938
18939 Set_Small_Value (Implicit_Base, Small_Val);
18940
18941 -- If no range was given, set a dummy range
18942
18943 if RRS <= Empty_Or_Error then
18944 Low_Val := -Small_Val;
18945 High_Val := Small_Val;
18946
18947 -- Otherwise analyze and process given range
18948
18949 else
18950 declare
18951 Low : constant Node_Id := Low_Bound (RRS);
18952 High : constant Node_Id := High_Bound (RRS);
18953
18954 begin
18955 Analyze_And_Resolve (Low, Any_Real);
18956 Analyze_And_Resolve (High, Any_Real);
18957 Check_Real_Bound (Low);
18958 Check_Real_Bound (High);
18959
18960 -- Obtain and set the range
18961
18962 Low_Val := Expr_Value_R (Low);
18963 High_Val := Expr_Value_R (High);
18964
18965 if Low_Val > High_Val then
18966 Error_Msg_NE ("??fixed point type& has null range", Def, T);
18967 end if;
18968 end;
18969 end if;
18970
18971 -- The range for both the implicit base and the declared first subtype
18972 -- cannot be set yet, so we use the special routine Set_Fixed_Range to
18973 -- set a temporary range in place. Note that the bounds of the base
18974 -- type will be widened to be symmetrical and to fill the available
18975 -- bits when the type is frozen.
18976
18977 -- We could do this with all discrete types, and probably should, but
18978 -- we absolutely have to do it for fixed-point, since the end-points
18979 -- of the range and the size are determined by the small value, which
18980 -- could be reset before the freeze point.
18981
18982 Set_Fixed_Range (Implicit_Base, Loc, Low_Val, High_Val);
18983 Set_Fixed_Range (T, Loc, Low_Val, High_Val);
18984
18985 -- Complete definition of first subtype. The inheritance of the rep item
18986 -- chain ensures that SPARK-related pragmas are not clobbered when the
18987 -- ordinary fixed point type acts as a full view of a private type.
18988
18989 Set_Ekind (T, E_Ordinary_Fixed_Point_Subtype);
18990 Set_Etype (T, Implicit_Base);
18991 Init_Size_Align (T);
18992 Inherit_Rep_Item_Chain (T, Implicit_Base);
18993 Set_Small_Value (T, Small_Val);
18994 Set_Delta_Value (T, Delta_Val);
18995 Set_Is_Constrained (T);
18996 end Ordinary_Fixed_Point_Type_Declaration;
18997
18998 ----------------------------------
18999 -- Preanalyze_Assert_Expression --
19000 ----------------------------------
19001
19002 procedure Preanalyze_Assert_Expression (N : Node_Id; T : Entity_Id) is
19003 begin
19004 In_Assertion_Expr := In_Assertion_Expr + 1;
19005 Preanalyze_Spec_Expression (N, T);
19006 In_Assertion_Expr := In_Assertion_Expr - 1;
19007 end Preanalyze_Assert_Expression;
19008
19009 -----------------------------------
19010 -- Preanalyze_Default_Expression --
19011 -----------------------------------
19012
19013 procedure Preanalyze_Default_Expression (N : Node_Id; T : Entity_Id) is
19014 Save_In_Default_Expr : constant Boolean := In_Default_Expr;
19015 begin
19016 In_Default_Expr := True;
19017 Preanalyze_Spec_Expression (N, T);
19018 In_Default_Expr := Save_In_Default_Expr;
19019 end Preanalyze_Default_Expression;
19020
19021 --------------------------------
19022 -- Preanalyze_Spec_Expression --
19023 --------------------------------
19024
19025 procedure Preanalyze_Spec_Expression (N : Node_Id; T : Entity_Id) is
19026 Save_In_Spec_Expression : constant Boolean := In_Spec_Expression;
19027 begin
19028 In_Spec_Expression := True;
19029 Preanalyze_And_Resolve (N, T);
19030 In_Spec_Expression := Save_In_Spec_Expression;
19031 end Preanalyze_Spec_Expression;
19032
19033 ----------------------------------------
19034 -- Prepare_Private_Subtype_Completion --
19035 ----------------------------------------
19036
19037 procedure Prepare_Private_Subtype_Completion
19038 (Id : Entity_Id;
19039 Related_Nod : Node_Id)
19040 is
19041 Id_B : constant Entity_Id := Base_Type (Id);
19042 Full_B : Entity_Id := Full_View (Id_B);
19043 Full : Entity_Id;
19044
19045 begin
19046 if Present (Full_B) then
19047
19048 -- Get to the underlying full view if necessary
19049
19050 if Is_Private_Type (Full_B)
19051 and then Present (Underlying_Full_View (Full_B))
19052 then
19053 Full_B := Underlying_Full_View (Full_B);
19054 end if;
19055
19056 -- The Base_Type is already completed, we can complete the subtype
19057 -- now. We have to create a new entity with the same name, Thus we
19058 -- can't use Create_Itype.
19059
19060 Full := Make_Defining_Identifier (Sloc (Id), Chars (Id));
19061 Set_Is_Itype (Full);
19062 Set_Associated_Node_For_Itype (Full, Related_Nod);
19063 Complete_Private_Subtype (Id, Full, Full_B, Related_Nod);
19064 end if;
19065
19066 -- The parent subtype may be private, but the base might not, in some
19067 -- nested instances. In that case, the subtype does not need to be
19068 -- exchanged. It would still be nice to make private subtypes and their
19069 -- bases consistent at all times ???
19070
19071 if Is_Private_Type (Id_B) then
19072 Append_Elmt (Id, Private_Dependents (Id_B));
19073 end if;
19074 end Prepare_Private_Subtype_Completion;
19075
19076 ---------------------------
19077 -- Process_Discriminants --
19078 ---------------------------
19079
19080 procedure Process_Discriminants
19081 (N : Node_Id;
19082 Prev : Entity_Id := Empty)
19083 is
19084 Elist : constant Elist_Id := New_Elmt_List;
19085 Id : Node_Id;
19086 Discr : Node_Id;
19087 Discr_Number : Uint;
19088 Discr_Type : Entity_Id;
19089 Default_Present : Boolean := False;
19090 Default_Not_Present : Boolean := False;
19091
19092 begin
19093 -- A composite type other than an array type can have discriminants.
19094 -- On entry, the current scope is the composite type.
19095
19096 -- The discriminants are initially entered into the scope of the type
19097 -- via Enter_Name with the default Ekind of E_Void to prevent premature
19098 -- use, as explained at the end of this procedure.
19099
19100 Discr := First (Discriminant_Specifications (N));
19101 while Present (Discr) loop
19102 Enter_Name (Defining_Identifier (Discr));
19103
19104 -- For navigation purposes we add a reference to the discriminant
19105 -- in the entity for the type. If the current declaration is a
19106 -- completion, place references on the partial view. Otherwise the
19107 -- type is the current scope.
19108
19109 if Present (Prev) then
19110
19111 -- The references go on the partial view, if present. If the
19112 -- partial view has discriminants, the references have been
19113 -- generated already.
19114
19115 if not Has_Discriminants (Prev) then
19116 Generate_Reference (Prev, Defining_Identifier (Discr), 'd');
19117 end if;
19118 else
19119 Generate_Reference
19120 (Current_Scope, Defining_Identifier (Discr), 'd');
19121 end if;
19122
19123 if Nkind (Discriminant_Type (Discr)) = N_Access_Definition then
19124 Discr_Type := Access_Definition (Discr, Discriminant_Type (Discr));
19125
19126 -- Ada 2005 (AI-254)
19127
19128 if Present (Access_To_Subprogram_Definition
19129 (Discriminant_Type (Discr)))
19130 and then Protected_Present (Access_To_Subprogram_Definition
19131 (Discriminant_Type (Discr)))
19132 then
19133 Discr_Type :=
19134 Replace_Anonymous_Access_To_Protected_Subprogram (Discr);
19135 end if;
19136
19137 else
19138 Find_Type (Discriminant_Type (Discr));
19139 Discr_Type := Etype (Discriminant_Type (Discr));
19140
19141 if Error_Posted (Discriminant_Type (Discr)) then
19142 Discr_Type := Any_Type;
19143 end if;
19144 end if;
19145
19146 -- Handling of discriminants that are access types
19147
19148 if Is_Access_Type (Discr_Type) then
19149
19150 -- Ada 2005 (AI-230): Access discriminant allowed in non-
19151 -- limited record types
19152
19153 if Ada_Version < Ada_2005 then
19154 Check_Access_Discriminant_Requires_Limited
19155 (Discr, Discriminant_Type (Discr));
19156 end if;
19157
19158 if Ada_Version = Ada_83 and then Comes_From_Source (Discr) then
19159 Error_Msg_N
19160 ("(Ada 83) access discriminant not allowed", Discr);
19161 end if;
19162
19163 -- If not access type, must be a discrete type
19164
19165 elsif not Is_Discrete_Type (Discr_Type) then
19166 Error_Msg_N
19167 ("discriminants must have a discrete or access type",
19168 Discriminant_Type (Discr));
19169 end if;
19170
19171 Set_Etype (Defining_Identifier (Discr), Discr_Type);
19172
19173 -- If a discriminant specification includes the assignment compound
19174 -- delimiter followed by an expression, the expression is the default
19175 -- expression of the discriminant; the default expression must be of
19176 -- the type of the discriminant. (RM 3.7.1) Since this expression is
19177 -- a default expression, we do the special preanalysis, since this
19178 -- expression does not freeze (see section "Handling of Default and
19179 -- Per-Object Expressions" in spec of package Sem).
19180
19181 if Present (Expression (Discr)) then
19182 Preanalyze_Spec_Expression (Expression (Discr), Discr_Type);
19183
19184 -- Legaity checks
19185
19186 if Nkind (N) = N_Formal_Type_Declaration then
19187 Error_Msg_N
19188 ("discriminant defaults not allowed for formal type",
19189 Expression (Discr));
19190
19191 -- Flag an error for a tagged type with defaulted discriminants,
19192 -- excluding limited tagged types when compiling for Ada 2012
19193 -- (see AI05-0214).
19194
19195 elsif Is_Tagged_Type (Current_Scope)
19196 and then (not Is_Limited_Type (Current_Scope)
19197 or else Ada_Version < Ada_2012)
19198 and then Comes_From_Source (N)
19199 then
19200 -- Note: see similar test in Check_Or_Process_Discriminants, to
19201 -- handle the (illegal) case of the completion of an untagged
19202 -- view with discriminants with defaults by a tagged full view.
19203 -- We skip the check if Discr does not come from source, to
19204 -- account for the case of an untagged derived type providing
19205 -- defaults for a renamed discriminant from a private untagged
19206 -- ancestor with a tagged full view (ACATS B460006).
19207
19208 if Ada_Version >= Ada_2012 then
19209 Error_Msg_N
19210 ("discriminants of nonlimited tagged type cannot have"
19211 & " defaults",
19212 Expression (Discr));
19213 else
19214 Error_Msg_N
19215 ("discriminants of tagged type cannot have defaults",
19216 Expression (Discr));
19217 end if;
19218
19219 else
19220 Default_Present := True;
19221 Append_Elmt (Expression (Discr), Elist);
19222
19223 -- Tag the defining identifiers for the discriminants with
19224 -- their corresponding default expressions from the tree.
19225
19226 Set_Discriminant_Default_Value
19227 (Defining_Identifier (Discr), Expression (Discr));
19228 end if;
19229
19230 -- In gnatc or gnatprove mode, make sure set Do_Range_Check flag
19231 -- gets set unless we can be sure that no range check is required.
19232
19233 if (GNATprove_Mode or not Expander_Active)
19234 and then not
19235 Is_In_Range
19236 (Expression (Discr), Discr_Type, Assume_Valid => True)
19237 then
19238 Set_Do_Range_Check (Expression (Discr));
19239 end if;
19240
19241 -- No default discriminant value given
19242
19243 else
19244 Default_Not_Present := True;
19245 end if;
19246
19247 -- Ada 2005 (AI-231): Create an Itype that is a duplicate of
19248 -- Discr_Type but with the null-exclusion attribute
19249
19250 if Ada_Version >= Ada_2005 then
19251
19252 -- Ada 2005 (AI-231): Static checks
19253
19254 if Can_Never_Be_Null (Discr_Type) then
19255 Null_Exclusion_Static_Checks (Discr);
19256
19257 elsif Is_Access_Type (Discr_Type)
19258 and then Null_Exclusion_Present (Discr)
19259
19260 -- No need to check itypes because in their case this check
19261 -- was done at their point of creation
19262
19263 and then not Is_Itype (Discr_Type)
19264 then
19265 if Can_Never_Be_Null (Discr_Type) then
19266 Error_Msg_NE
19267 ("`NOT NULL` not allowed (& already excludes null)",
19268 Discr,
19269 Discr_Type);
19270 end if;
19271
19272 Set_Etype (Defining_Identifier (Discr),
19273 Create_Null_Excluding_Itype
19274 (T => Discr_Type,
19275 Related_Nod => Discr));
19276
19277 -- Check for improper null exclusion if the type is otherwise
19278 -- legal for a discriminant.
19279
19280 elsif Null_Exclusion_Present (Discr)
19281 and then Is_Discrete_Type (Discr_Type)
19282 then
19283 Error_Msg_N
19284 ("null exclusion can only apply to an access type", Discr);
19285 end if;
19286
19287 -- Ada 2005 (AI-402): access discriminants of nonlimited types
19288 -- can't have defaults. Synchronized types, or types that are
19289 -- explicitly limited are fine, but special tests apply to derived
19290 -- types in generics: in a generic body we have to assume the
19291 -- worst, and therefore defaults are not allowed if the parent is
19292 -- a generic formal private type (see ACATS B370001).
19293
19294 if Is_Access_Type (Discr_Type) and then Default_Present then
19295 if Ekind (Discr_Type) /= E_Anonymous_Access_Type
19296 or else Is_Limited_Record (Current_Scope)
19297 or else Is_Concurrent_Type (Current_Scope)
19298 or else Is_Concurrent_Record_Type (Current_Scope)
19299 or else Ekind (Current_Scope) = E_Limited_Private_Type
19300 then
19301 if not Is_Derived_Type (Current_Scope)
19302 or else not Is_Generic_Type (Etype (Current_Scope))
19303 or else not In_Package_Body (Scope (Etype (Current_Scope)))
19304 or else Limited_Present
19305 (Type_Definition (Parent (Current_Scope)))
19306 then
19307 null;
19308
19309 else
19310 Error_Msg_N
19311 ("access discriminants of nonlimited types cannot "
19312 & "have defaults", Expression (Discr));
19313 end if;
19314
19315 elsif Present (Expression (Discr)) then
19316 Error_Msg_N
19317 ("(Ada 2005) access discriminants of nonlimited types "
19318 & "cannot have defaults", Expression (Discr));
19319 end if;
19320 end if;
19321 end if;
19322
19323 -- A discriminant cannot be effectively volatile (SPARK RM 7.1.3(6)).
19324 -- This check is relevant only when SPARK_Mode is on as it is not a
19325 -- standard Ada legality rule.
19326
19327 if SPARK_Mode = On
19328 and then Is_Effectively_Volatile (Defining_Identifier (Discr))
19329 then
19330 Error_Msg_N ("discriminant cannot be volatile", Discr);
19331 end if;
19332
19333 Next (Discr);
19334 end loop;
19335
19336 -- An element list consisting of the default expressions of the
19337 -- discriminants is constructed in the above loop and used to set
19338 -- the Discriminant_Constraint attribute for the type. If an object
19339 -- is declared of this (record or task) type without any explicit
19340 -- discriminant constraint given, this element list will form the
19341 -- actual parameters for the corresponding initialization procedure
19342 -- for the type.
19343
19344 Set_Discriminant_Constraint (Current_Scope, Elist);
19345 Set_Stored_Constraint (Current_Scope, No_Elist);
19346
19347 -- Default expressions must be provided either for all or for none
19348 -- of the discriminants of a discriminant part. (RM 3.7.1)
19349
19350 if Default_Present and then Default_Not_Present then
19351 Error_Msg_N
19352 ("incomplete specification of defaults for discriminants", N);
19353 end if;
19354
19355 -- The use of the name of a discriminant is not allowed in default
19356 -- expressions of a discriminant part if the specification of the
19357 -- discriminant is itself given in the discriminant part. (RM 3.7.1)
19358
19359 -- To detect this, the discriminant names are entered initially with an
19360 -- Ekind of E_Void (which is the default Ekind given by Enter_Name). Any
19361 -- attempt to use a void entity (for example in an expression that is
19362 -- type-checked) produces the error message: premature usage. Now after
19363 -- completing the semantic analysis of the discriminant part, we can set
19364 -- the Ekind of all the discriminants appropriately.
19365
19366 Discr := First (Discriminant_Specifications (N));
19367 Discr_Number := Uint_1;
19368 while Present (Discr) loop
19369 Id := Defining_Identifier (Discr);
19370 Set_Ekind (Id, E_Discriminant);
19371 Init_Component_Location (Id);
19372 Init_Esize (Id);
19373 Set_Discriminant_Number (Id, Discr_Number);
19374
19375 -- Make sure this is always set, even in illegal programs
19376
19377 Set_Corresponding_Discriminant (Id, Empty);
19378
19379 -- Initialize the Original_Record_Component to the entity itself.
19380 -- Inherit_Components will propagate the right value to
19381 -- discriminants in derived record types.
19382
19383 Set_Original_Record_Component (Id, Id);
19384
19385 -- Create the discriminal for the discriminant
19386
19387 Build_Discriminal (Id);
19388
19389 Next (Discr);
19390 Discr_Number := Discr_Number + 1;
19391 end loop;
19392
19393 Set_Has_Discriminants (Current_Scope);
19394 end Process_Discriminants;
19395
19396 -----------------------
19397 -- Process_Full_View --
19398 -----------------------
19399
19400 procedure Process_Full_View (N : Node_Id; Full_T, Priv_T : Entity_Id) is
19401 procedure Collect_Implemented_Interfaces
19402 (Typ : Entity_Id;
19403 Ifaces : Elist_Id);
19404 -- Ada 2005: Gather all the interfaces that Typ directly or
19405 -- inherently implements. Duplicate entries are not added to
19406 -- the list Ifaces.
19407
19408 ------------------------------------
19409 -- Collect_Implemented_Interfaces --
19410 ------------------------------------
19411
19412 procedure Collect_Implemented_Interfaces
19413 (Typ : Entity_Id;
19414 Ifaces : Elist_Id)
19415 is
19416 Iface : Entity_Id;
19417 Iface_Elmt : Elmt_Id;
19418
19419 begin
19420 -- Abstract interfaces are only associated with tagged record types
19421
19422 if not Is_Tagged_Type (Typ) or else not Is_Record_Type (Typ) then
19423 return;
19424 end if;
19425
19426 -- Recursively climb to the ancestors
19427
19428 if Etype (Typ) /= Typ
19429
19430 -- Protect the frontend against wrong cyclic declarations like:
19431
19432 -- type B is new A with private;
19433 -- type C is new A with private;
19434 -- private
19435 -- type B is new C with null record;
19436 -- type C is new B with null record;
19437
19438 and then Etype (Typ) /= Priv_T
19439 and then Etype (Typ) /= Full_T
19440 then
19441 -- Keep separate the management of private type declarations
19442
19443 if Ekind (Typ) = E_Record_Type_With_Private then
19444
19445 -- Handle the following illegal usage:
19446 -- type Private_Type is tagged private;
19447 -- private
19448 -- type Private_Type is new Type_Implementing_Iface;
19449
19450 if Present (Full_View (Typ))
19451 and then Etype (Typ) /= Full_View (Typ)
19452 then
19453 if Is_Interface (Etype (Typ)) then
19454 Append_Unique_Elmt (Etype (Typ), Ifaces);
19455 end if;
19456
19457 Collect_Implemented_Interfaces (Etype (Typ), Ifaces);
19458 end if;
19459
19460 -- Non-private types
19461
19462 else
19463 if Is_Interface (Etype (Typ)) then
19464 Append_Unique_Elmt (Etype (Typ), Ifaces);
19465 end if;
19466
19467 Collect_Implemented_Interfaces (Etype (Typ), Ifaces);
19468 end if;
19469 end if;
19470
19471 -- Handle entities in the list of abstract interfaces
19472
19473 if Present (Interfaces (Typ)) then
19474 Iface_Elmt := First_Elmt (Interfaces (Typ));
19475 while Present (Iface_Elmt) loop
19476 Iface := Node (Iface_Elmt);
19477
19478 pragma Assert (Is_Interface (Iface));
19479
19480 if not Contain_Interface (Iface, Ifaces) then
19481 Append_Elmt (Iface, Ifaces);
19482 Collect_Implemented_Interfaces (Iface, Ifaces);
19483 end if;
19484
19485 Next_Elmt (Iface_Elmt);
19486 end loop;
19487 end if;
19488 end Collect_Implemented_Interfaces;
19489
19490 -- Local variables
19491
19492 Full_Indic : Node_Id;
19493 Full_Parent : Entity_Id;
19494 Priv_Parent : Entity_Id;
19495
19496 -- Start of processing for Process_Full_View
19497
19498 begin
19499 -- First some sanity checks that must be done after semantic
19500 -- decoration of the full view and thus cannot be placed with other
19501 -- similar checks in Find_Type_Name
19502
19503 if not Is_Limited_Type (Priv_T)
19504 and then (Is_Limited_Type (Full_T)
19505 or else Is_Limited_Composite (Full_T))
19506 then
19507 if In_Instance then
19508 null;
19509 else
19510 Error_Msg_N
19511 ("completion of nonlimited type cannot be limited", Full_T);
19512 Explain_Limited_Type (Full_T, Full_T);
19513 end if;
19514
19515 elsif Is_Abstract_Type (Full_T)
19516 and then not Is_Abstract_Type (Priv_T)
19517 then
19518 Error_Msg_N
19519 ("completion of nonabstract type cannot be abstract", Full_T);
19520
19521 elsif Is_Tagged_Type (Priv_T)
19522 and then Is_Limited_Type (Priv_T)
19523 and then not Is_Limited_Type (Full_T)
19524 then
19525 -- If pragma CPP_Class was applied to the private declaration
19526 -- propagate the limitedness to the full-view
19527
19528 if Is_CPP_Class (Priv_T) then
19529 Set_Is_Limited_Record (Full_T);
19530
19531 -- GNAT allow its own definition of Limited_Controlled to disobey
19532 -- this rule in order in ease the implementation. This test is safe
19533 -- because Root_Controlled is defined in a child of System that
19534 -- normal programs are not supposed to use.
19535
19536 elsif Is_RTE (Etype (Full_T), RE_Root_Controlled) then
19537 Set_Is_Limited_Composite (Full_T);
19538 else
19539 Error_Msg_N
19540 ("completion of limited tagged type must be limited", Full_T);
19541 end if;
19542
19543 elsif Is_Generic_Type (Priv_T) then
19544 Error_Msg_N ("generic type cannot have a completion", Full_T);
19545 end if;
19546
19547 -- Check that ancestor interfaces of private and full views are
19548 -- consistent. We omit this check for synchronized types because
19549 -- they are performed on the corresponding record type when frozen.
19550
19551 if Ada_Version >= Ada_2005
19552 and then Is_Tagged_Type (Priv_T)
19553 and then Is_Tagged_Type (Full_T)
19554 and then not Is_Concurrent_Type (Full_T)
19555 then
19556 declare
19557 Iface : Entity_Id;
19558 Priv_T_Ifaces : constant Elist_Id := New_Elmt_List;
19559 Full_T_Ifaces : constant Elist_Id := New_Elmt_List;
19560
19561 begin
19562 Collect_Implemented_Interfaces (Priv_T, Priv_T_Ifaces);
19563 Collect_Implemented_Interfaces (Full_T, Full_T_Ifaces);
19564
19565 -- Ada 2005 (AI-251): The partial view shall be a descendant of
19566 -- an interface type if and only if the full type is descendant
19567 -- of the interface type (AARM 7.3 (7.3/2)).
19568
19569 Iface := Find_Hidden_Interface (Priv_T_Ifaces, Full_T_Ifaces);
19570
19571 if Present (Iface) then
19572 Error_Msg_NE
19573 ("interface in partial view& not implemented by full type "
19574 & "(RM-2005 7.3 (7.3/2))", Full_T, Iface);
19575 end if;
19576
19577 Iface := Find_Hidden_Interface (Full_T_Ifaces, Priv_T_Ifaces);
19578
19579 if Present (Iface) then
19580 Error_Msg_NE
19581 ("interface & not implemented by partial view "
19582 & "(RM-2005 7.3 (7.3/2))", Full_T, Iface);
19583 end if;
19584 end;
19585 end if;
19586
19587 if Is_Tagged_Type (Priv_T)
19588 and then Nkind (Parent (Priv_T)) = N_Private_Extension_Declaration
19589 and then Is_Derived_Type (Full_T)
19590 then
19591 Priv_Parent := Etype (Priv_T);
19592
19593 -- The full view of a private extension may have been transformed
19594 -- into an unconstrained derived type declaration and a subtype
19595 -- declaration (see build_derived_record_type for details).
19596
19597 if Nkind (N) = N_Subtype_Declaration then
19598 Full_Indic := Subtype_Indication (N);
19599 Full_Parent := Etype (Base_Type (Full_T));
19600 else
19601 Full_Indic := Subtype_Indication (Type_Definition (N));
19602 Full_Parent := Etype (Full_T);
19603 end if;
19604
19605 -- Check that the parent type of the full type is a descendant of
19606 -- the ancestor subtype given in the private extension. If either
19607 -- entity has an Etype equal to Any_Type then we had some previous
19608 -- error situation [7.3(8)].
19609
19610 if Priv_Parent = Any_Type or else Full_Parent = Any_Type then
19611 return;
19612
19613 -- Ada 2005 (AI-251): Interfaces in the full type can be given in
19614 -- any order. Therefore we don't have to check that its parent must
19615 -- be a descendant of the parent of the private type declaration.
19616
19617 elsif Is_Interface (Priv_Parent)
19618 and then Is_Interface (Full_Parent)
19619 then
19620 null;
19621
19622 -- Ada 2005 (AI-251): If the parent of the private type declaration
19623 -- is an interface there is no need to check that it is an ancestor
19624 -- of the associated full type declaration. The required tests for
19625 -- this case are performed by Build_Derived_Record_Type.
19626
19627 elsif not Is_Interface (Base_Type (Priv_Parent))
19628 and then not Is_Ancestor (Base_Type (Priv_Parent), Full_Parent)
19629 then
19630 Error_Msg_N
19631 ("parent of full type must descend from parent of private "
19632 & "extension", Full_Indic);
19633
19634 -- First check a formal restriction, and then proceed with checking
19635 -- Ada rules. Since the formal restriction is not a serious error, we
19636 -- don't prevent further error detection for this check, hence the
19637 -- ELSE.
19638
19639 else
19640 -- In formal mode, when completing a private extension the type
19641 -- named in the private part must be exactly the same as that
19642 -- named in the visible part.
19643
19644 if Priv_Parent /= Full_Parent then
19645 Error_Msg_Name_1 := Chars (Priv_Parent);
19646 Check_SPARK_05_Restriction ("% expected", Full_Indic);
19647 end if;
19648
19649 -- Check the rules of 7.3(10): if the private extension inherits
19650 -- known discriminants, then the full type must also inherit those
19651 -- discriminants from the same (ancestor) type, and the parent
19652 -- subtype of the full type must be constrained if and only if
19653 -- the ancestor subtype of the private extension is constrained.
19654
19655 if No (Discriminant_Specifications (Parent (Priv_T)))
19656 and then not Has_Unknown_Discriminants (Priv_T)
19657 and then Has_Discriminants (Base_Type (Priv_Parent))
19658 then
19659 declare
19660 Priv_Indic : constant Node_Id :=
19661 Subtype_Indication (Parent (Priv_T));
19662
19663 Priv_Constr : constant Boolean :=
19664 Is_Constrained (Priv_Parent)
19665 or else
19666 Nkind (Priv_Indic) = N_Subtype_Indication
19667 or else
19668 Is_Constrained (Entity (Priv_Indic));
19669
19670 Full_Constr : constant Boolean :=
19671 Is_Constrained (Full_Parent)
19672 or else
19673 Nkind (Full_Indic) = N_Subtype_Indication
19674 or else
19675 Is_Constrained (Entity (Full_Indic));
19676
19677 Priv_Discr : Entity_Id;
19678 Full_Discr : Entity_Id;
19679
19680 begin
19681 Priv_Discr := First_Discriminant (Priv_Parent);
19682 Full_Discr := First_Discriminant (Full_Parent);
19683 while Present (Priv_Discr) and then Present (Full_Discr) loop
19684 if Original_Record_Component (Priv_Discr) =
19685 Original_Record_Component (Full_Discr)
19686 or else
19687 Corresponding_Discriminant (Priv_Discr) =
19688 Corresponding_Discriminant (Full_Discr)
19689 then
19690 null;
19691 else
19692 exit;
19693 end if;
19694
19695 Next_Discriminant (Priv_Discr);
19696 Next_Discriminant (Full_Discr);
19697 end loop;
19698
19699 if Present (Priv_Discr) or else Present (Full_Discr) then
19700 Error_Msg_N
19701 ("full view must inherit discriminants of the parent "
19702 & "type used in the private extension", Full_Indic);
19703
19704 elsif Priv_Constr and then not Full_Constr then
19705 Error_Msg_N
19706 ("parent subtype of full type must be constrained",
19707 Full_Indic);
19708
19709 elsif Full_Constr and then not Priv_Constr then
19710 Error_Msg_N
19711 ("parent subtype of full type must be unconstrained",
19712 Full_Indic);
19713 end if;
19714 end;
19715
19716 -- Check the rules of 7.3(12): if a partial view has neither
19717 -- known or unknown discriminants, then the full type
19718 -- declaration shall define a definite subtype.
19719
19720 elsif not Has_Unknown_Discriminants (Priv_T)
19721 and then not Has_Discriminants (Priv_T)
19722 and then not Is_Constrained (Full_T)
19723 then
19724 Error_Msg_N
19725 ("full view must define a constrained type if partial view "
19726 & "has no discriminants", Full_T);
19727 end if;
19728
19729 -- ??????? Do we implement the following properly ?????
19730 -- If the ancestor subtype of a private extension has constrained
19731 -- discriminants, then the parent subtype of the full view shall
19732 -- impose a statically matching constraint on those discriminants
19733 -- [7.3(13)].
19734 end if;
19735
19736 else
19737 -- For untagged types, verify that a type without discriminants is
19738 -- not completed with an unconstrained type. A separate error message
19739 -- is produced if the full type has defaulted discriminants.
19740
19741 if Is_Definite_Subtype (Priv_T)
19742 and then not Is_Definite_Subtype (Full_T)
19743 then
19744 Error_Msg_Sloc := Sloc (Parent (Priv_T));
19745 Error_Msg_NE
19746 ("full view of& not compatible with declaration#",
19747 Full_T, Priv_T);
19748
19749 if not Is_Tagged_Type (Full_T) then
19750 Error_Msg_N
19751 ("\one is constrained, the other unconstrained", Full_T);
19752 end if;
19753 end if;
19754 end if;
19755
19756 -- AI-419: verify that the use of "limited" is consistent
19757
19758 declare
19759 Orig_Decl : constant Node_Id := Original_Node (N);
19760
19761 begin
19762 if Nkind (Parent (Priv_T)) = N_Private_Extension_Declaration
19763 and then Nkind (Orig_Decl) = N_Full_Type_Declaration
19764 and then Nkind
19765 (Type_Definition (Orig_Decl)) = N_Derived_Type_Definition
19766 then
19767 if not Limited_Present (Parent (Priv_T))
19768 and then not Synchronized_Present (Parent (Priv_T))
19769 and then Limited_Present (Type_Definition (Orig_Decl))
19770 then
19771 Error_Msg_N
19772 ("full view of non-limited extension cannot be limited", N);
19773
19774 -- Conversely, if the partial view carries the limited keyword,
19775 -- the full view must as well, even if it may be redundant.
19776
19777 elsif Limited_Present (Parent (Priv_T))
19778 and then not Limited_Present (Type_Definition (Orig_Decl))
19779 then
19780 Error_Msg_N
19781 ("full view of limited extension must be explicitly limited",
19782 N);
19783 end if;
19784 end if;
19785 end;
19786
19787 -- Ada 2005 (AI-443): A synchronized private extension must be
19788 -- completed by a task or protected type.
19789
19790 if Ada_Version >= Ada_2005
19791 and then Nkind (Parent (Priv_T)) = N_Private_Extension_Declaration
19792 and then Synchronized_Present (Parent (Priv_T))
19793 and then not Is_Concurrent_Type (Full_T)
19794 then
19795 Error_Msg_N ("full view of synchronized extension must " &
19796 "be synchronized type", N);
19797 end if;
19798
19799 -- Ada 2005 AI-363: if the full view has discriminants with
19800 -- defaults, it is illegal to declare constrained access subtypes
19801 -- whose designated type is the current type. This allows objects
19802 -- of the type that are declared in the heap to be unconstrained.
19803
19804 if not Has_Unknown_Discriminants (Priv_T)
19805 and then not Has_Discriminants (Priv_T)
19806 and then Has_Discriminants (Full_T)
19807 and then
19808 Present (Discriminant_Default_Value (First_Discriminant (Full_T)))
19809 then
19810 Set_Has_Constrained_Partial_View (Full_T);
19811 Set_Has_Constrained_Partial_View (Priv_T);
19812 end if;
19813
19814 -- Create a full declaration for all its subtypes recorded in
19815 -- Private_Dependents and swap them similarly to the base type. These
19816 -- are subtypes that have been define before the full declaration of
19817 -- the private type. We also swap the entry in Private_Dependents list
19818 -- so we can properly restore the private view on exit from the scope.
19819
19820 declare
19821 Priv_Elmt : Elmt_Id;
19822 Priv_Scop : Entity_Id;
19823 Priv : Entity_Id;
19824 Full : Entity_Id;
19825
19826 begin
19827 Priv_Elmt := First_Elmt (Private_Dependents (Priv_T));
19828 while Present (Priv_Elmt) loop
19829 Priv := Node (Priv_Elmt);
19830 Priv_Scop := Scope (Priv);
19831
19832 if Ekind_In (Priv, E_Private_Subtype,
19833 E_Limited_Private_Subtype,
19834 E_Record_Subtype_With_Private)
19835 then
19836 Full := Make_Defining_Identifier (Sloc (Priv), Chars (Priv));
19837 Set_Is_Itype (Full);
19838 Set_Parent (Full, Parent (Priv));
19839 Set_Associated_Node_For_Itype (Full, N);
19840
19841 -- Now we need to complete the private subtype, but since the
19842 -- base type has already been swapped, we must also swap the
19843 -- subtypes (and thus, reverse the arguments in the call to
19844 -- Complete_Private_Subtype). Also note that we may need to
19845 -- re-establish the scope of the private subtype.
19846
19847 Copy_And_Swap (Priv, Full);
19848
19849 if not In_Open_Scopes (Priv_Scop) then
19850 Push_Scope (Priv_Scop);
19851
19852 else
19853 -- Reset Priv_Scop to Empty to indicate no scope was pushed
19854
19855 Priv_Scop := Empty;
19856 end if;
19857
19858 Complete_Private_Subtype (Full, Priv, Full_T, N);
19859
19860 if Present (Priv_Scop) then
19861 Pop_Scope;
19862 end if;
19863
19864 Replace_Elmt (Priv_Elmt, Full);
19865 end if;
19866
19867 Next_Elmt (Priv_Elmt);
19868 end loop;
19869 end;
19870
19871 -- If the private view was tagged, copy the new primitive operations
19872 -- from the private view to the full view.
19873
19874 if Is_Tagged_Type (Full_T) then
19875 declare
19876 Disp_Typ : Entity_Id;
19877 Full_List : Elist_Id;
19878 Prim : Entity_Id;
19879 Prim_Elmt : Elmt_Id;
19880 Priv_List : Elist_Id;
19881
19882 function Contains
19883 (E : Entity_Id;
19884 L : Elist_Id) return Boolean;
19885 -- Determine whether list L contains element E
19886
19887 --------------
19888 -- Contains --
19889 --------------
19890
19891 function Contains
19892 (E : Entity_Id;
19893 L : Elist_Id) return Boolean
19894 is
19895 List_Elmt : Elmt_Id;
19896
19897 begin
19898 List_Elmt := First_Elmt (L);
19899 while Present (List_Elmt) loop
19900 if Node (List_Elmt) = E then
19901 return True;
19902 end if;
19903
19904 Next_Elmt (List_Elmt);
19905 end loop;
19906
19907 return False;
19908 end Contains;
19909
19910 -- Start of processing
19911
19912 begin
19913 if Is_Tagged_Type (Priv_T) then
19914 Priv_List := Primitive_Operations (Priv_T);
19915 Prim_Elmt := First_Elmt (Priv_List);
19916
19917 -- In the case of a concurrent type completing a private tagged
19918 -- type, primitives may have been declared in between the two
19919 -- views. These subprograms need to be wrapped the same way
19920 -- entries and protected procedures are handled because they
19921 -- cannot be directly shared by the two views.
19922
19923 if Is_Concurrent_Type (Full_T) then
19924 declare
19925 Conc_Typ : constant Entity_Id :=
19926 Corresponding_Record_Type (Full_T);
19927 Curr_Nod : Node_Id := Parent (Conc_Typ);
19928 Wrap_Spec : Node_Id;
19929
19930 begin
19931 while Present (Prim_Elmt) loop
19932 Prim := Node (Prim_Elmt);
19933
19934 if Comes_From_Source (Prim)
19935 and then not Is_Abstract_Subprogram (Prim)
19936 then
19937 Wrap_Spec :=
19938 Make_Subprogram_Declaration (Sloc (Prim),
19939 Specification =>
19940 Build_Wrapper_Spec
19941 (Subp_Id => Prim,
19942 Obj_Typ => Conc_Typ,
19943 Formals =>
19944 Parameter_Specifications
19945 (Parent (Prim))));
19946
19947 Insert_After (Curr_Nod, Wrap_Spec);
19948 Curr_Nod := Wrap_Spec;
19949
19950 Analyze (Wrap_Spec);
19951
19952 -- Remove the wrapper from visibility to avoid
19953 -- spurious conflict with the wrapped entity.
19954
19955 Set_Is_Immediately_Visible
19956 (Defining_Entity (Specification (Wrap_Spec)),
19957 False);
19958 end if;
19959
19960 Next_Elmt (Prim_Elmt);
19961 end loop;
19962
19963 return;
19964 end;
19965
19966 -- For non-concurrent types, transfer explicit primitives, but
19967 -- omit those inherited from the parent of the private view
19968 -- since they will be re-inherited later on.
19969
19970 else
19971 Full_List := Primitive_Operations (Full_T);
19972
19973 while Present (Prim_Elmt) loop
19974 Prim := Node (Prim_Elmt);
19975
19976 if Comes_From_Source (Prim)
19977 and then not Contains (Prim, Full_List)
19978 then
19979 Append_Elmt (Prim, Full_List);
19980 end if;
19981
19982 Next_Elmt (Prim_Elmt);
19983 end loop;
19984 end if;
19985
19986 -- Untagged private view
19987
19988 else
19989 Full_List := Primitive_Operations (Full_T);
19990
19991 -- In this case the partial view is untagged, so here we locate
19992 -- all of the earlier primitives that need to be treated as
19993 -- dispatching (those that appear between the two views). Note
19994 -- that these additional operations must all be new operations
19995 -- (any earlier operations that override inherited operations
19996 -- of the full view will already have been inserted in the
19997 -- primitives list, marked by Check_Operation_From_Private_View
19998 -- as dispatching. Note that implicit "/=" operators are
19999 -- excluded from being added to the primitives list since they
20000 -- shouldn't be treated as dispatching (tagged "/=" is handled
20001 -- specially).
20002
20003 Prim := Next_Entity (Full_T);
20004 while Present (Prim) and then Prim /= Priv_T loop
20005 if Ekind_In (Prim, E_Procedure, E_Function) then
20006 Disp_Typ := Find_Dispatching_Type (Prim);
20007
20008 if Disp_Typ = Full_T
20009 and then (Chars (Prim) /= Name_Op_Ne
20010 or else Comes_From_Source (Prim))
20011 then
20012 Check_Controlling_Formals (Full_T, Prim);
20013
20014 if not Is_Dispatching_Operation (Prim) then
20015 Append_Elmt (Prim, Full_List);
20016 Set_Is_Dispatching_Operation (Prim, True);
20017 Set_DT_Position_Value (Prim, No_Uint);
20018 end if;
20019
20020 elsif Is_Dispatching_Operation (Prim)
20021 and then Disp_Typ /= Full_T
20022 then
20023
20024 -- Verify that it is not otherwise controlled by a
20025 -- formal or a return value of type T.
20026
20027 Check_Controlling_Formals (Disp_Typ, Prim);
20028 end if;
20029 end if;
20030
20031 Next_Entity (Prim);
20032 end loop;
20033 end if;
20034
20035 -- For the tagged case, the two views can share the same primitive
20036 -- operations list and the same class-wide type. Update attributes
20037 -- of the class-wide type which depend on the full declaration.
20038
20039 if Is_Tagged_Type (Priv_T) then
20040 Set_Direct_Primitive_Operations (Priv_T, Full_List);
20041 Set_Class_Wide_Type
20042 (Base_Type (Full_T), Class_Wide_Type (Priv_T));
20043
20044 Propagate_Concurrent_Flags (Class_Wide_Type (Priv_T), Full_T);
20045 end if;
20046 end;
20047 end if;
20048
20049 -- Ada 2005 AI 161: Check preelaborable initialization consistency
20050
20051 if Known_To_Have_Preelab_Init (Priv_T) then
20052
20053 -- Case where there is a pragma Preelaborable_Initialization. We
20054 -- always allow this in predefined units, which is cheating a bit,
20055 -- but it means we don't have to struggle to meet the requirements in
20056 -- the RM for having Preelaborable Initialization. Otherwise we
20057 -- require that the type meets the RM rules. But we can't check that
20058 -- yet, because of the rule about overriding Initialize, so we simply
20059 -- set a flag that will be checked at freeze time.
20060
20061 if not In_Predefined_Unit (Full_T) then
20062 Set_Must_Have_Preelab_Init (Full_T);
20063 end if;
20064 end if;
20065
20066 -- If pragma CPP_Class was applied to the private type declaration,
20067 -- propagate it now to the full type declaration.
20068
20069 if Is_CPP_Class (Priv_T) then
20070 Set_Is_CPP_Class (Full_T);
20071 Set_Convention (Full_T, Convention_CPP);
20072
20073 -- Check that components of imported CPP types do not have default
20074 -- expressions.
20075
20076 Check_CPP_Type_Has_No_Defaults (Full_T);
20077 end if;
20078
20079 -- If the private view has user specified stream attributes, then so has
20080 -- the full view.
20081
20082 -- Why the test, how could these flags be already set in Full_T ???
20083
20084 if Has_Specified_Stream_Read (Priv_T) then
20085 Set_Has_Specified_Stream_Read (Full_T);
20086 end if;
20087
20088 if Has_Specified_Stream_Write (Priv_T) then
20089 Set_Has_Specified_Stream_Write (Full_T);
20090 end if;
20091
20092 if Has_Specified_Stream_Input (Priv_T) then
20093 Set_Has_Specified_Stream_Input (Full_T);
20094 end if;
20095
20096 if Has_Specified_Stream_Output (Priv_T) then
20097 Set_Has_Specified_Stream_Output (Full_T);
20098 end if;
20099
20100 -- Propagate the attributes related to pragma Default_Initial_Condition
20101 -- from the private to the full view. Note that both flags are mutually
20102 -- exclusive.
20103
20104 if Has_Default_Init_Cond (Priv_T)
20105 or else Has_Inherited_Default_Init_Cond (Priv_T)
20106 then
20107 Propagate_Default_Init_Cond_Attributes
20108 (From_Typ => Priv_T,
20109 To_Typ => Full_T,
20110 Private_To_Full_View => True);
20111
20112 -- In the case where the full view is derived from another private type,
20113 -- the attributes related to pragma Default_Initial_Condition must be
20114 -- propagated from the full to the private view to maintain consistency
20115 -- of views.
20116
20117 -- package Pack is
20118 -- type Parent_Typ is private
20119 -- with Default_Initial_Condition ...;
20120 -- private
20121 -- type Parent_Typ is ...;
20122 -- end Pack;
20123
20124 -- with Pack; use Pack;
20125 -- package Pack_2 is
20126 -- type Deriv_Typ is private; -- must inherit
20127 -- private
20128 -- type Deriv_Typ is new Parent_Typ; -- must inherit
20129 -- end Pack_2;
20130
20131 elsif Has_Default_Init_Cond (Full_T)
20132 or else Has_Inherited_Default_Init_Cond (Full_T)
20133 then
20134 Propagate_Default_Init_Cond_Attributes
20135 (From_Typ => Full_T,
20136 To_Typ => Priv_T,
20137 Private_To_Full_View => True);
20138 end if;
20139
20140 if Is_Ghost_Entity (Priv_T) then
20141
20142 -- The Ghost policy in effect at the point of declaration and at the
20143 -- point of completion must match (SPARK RM 6.9(14)).
20144
20145 Check_Ghost_Completion (Priv_T, Full_T);
20146
20147 -- Propagate the attributes related to pragma Ghost from the private
20148 -- to the full view.
20149
20150 Mark_Full_View_As_Ghost (Priv_T, Full_T);
20151 end if;
20152
20153 -- Propagate invariant-related attributes from the private view to the
20154 -- full view and its base type.
20155
20156 Propagate_Invariant_Attributes (Full_T, From_Typ => Priv_T);
20157 Propagate_Invariant_Attributes (Base_Type (Full_T), From_Typ => Priv_T);
20158
20159 -- AI12-0041: Detect an attempt to inherit a class-wide type invariant
20160 -- in the full view without advertising the inheritance in the partial
20161 -- view. This can only occur when the partial view has no parent type
20162 -- and the full view has an interface as a parent. Any other scenarios
20163 -- are illegal because implemented interfaces must match between the
20164 -- two views.
20165
20166 if Is_Tagged_Type (Priv_T) and then Is_Tagged_Type (Full_T) then
20167 declare
20168 Full_Par : constant Entity_Id := Etype (Full_T);
20169 Priv_Par : constant Entity_Id := Etype (Priv_T);
20170
20171 begin
20172 if not Is_Interface (Priv_Par)
20173 and then Is_Interface (Full_Par)
20174 and then Has_Inheritable_Invariants (Full_Par)
20175 then
20176 Error_Msg_N
20177 ("hidden inheritance of class-wide type invariants not "
20178 & "allowed", N);
20179 end if;
20180 end;
20181 end if;
20182
20183 -- Propagate predicates to full type, and predicate function if already
20184 -- defined. It is not clear that this can actually happen? the partial
20185 -- view cannot be frozen yet, and the predicate function has not been
20186 -- built. Still it is a cheap check and seems safer to make it.
20187
20188 if Has_Predicates (Priv_T) then
20189 Set_Has_Predicates (Full_T);
20190
20191 if Present (Predicate_Function (Priv_T)) then
20192 Set_Predicate_Function (Full_T, Predicate_Function (Priv_T));
20193 end if;
20194 end if;
20195 end Process_Full_View;
20196
20197 -----------------------------------
20198 -- Process_Incomplete_Dependents --
20199 -----------------------------------
20200
20201 procedure Process_Incomplete_Dependents
20202 (N : Node_Id;
20203 Full_T : Entity_Id;
20204 Inc_T : Entity_Id)
20205 is
20206 Inc_Elmt : Elmt_Id;
20207 Priv_Dep : Entity_Id;
20208 New_Subt : Entity_Id;
20209
20210 Disc_Constraint : Elist_Id;
20211
20212 begin
20213 if No (Private_Dependents (Inc_T)) then
20214 return;
20215 end if;
20216
20217 -- Itypes that may be generated by the completion of an incomplete
20218 -- subtype are not used by the back-end and not attached to the tree.
20219 -- They are created only for constraint-checking purposes.
20220
20221 Inc_Elmt := First_Elmt (Private_Dependents (Inc_T));
20222 while Present (Inc_Elmt) loop
20223 Priv_Dep := Node (Inc_Elmt);
20224
20225 if Ekind (Priv_Dep) = E_Subprogram_Type then
20226
20227 -- An Access_To_Subprogram type may have a return type or a
20228 -- parameter type that is incomplete. Replace with the full view.
20229
20230 if Etype (Priv_Dep) = Inc_T then
20231 Set_Etype (Priv_Dep, Full_T);
20232 end if;
20233
20234 declare
20235 Formal : Entity_Id;
20236
20237 begin
20238 Formal := First_Formal (Priv_Dep);
20239 while Present (Formal) loop
20240 if Etype (Formal) = Inc_T then
20241 Set_Etype (Formal, Full_T);
20242 end if;
20243
20244 Next_Formal (Formal);
20245 end loop;
20246 end;
20247
20248 elsif Is_Overloadable (Priv_Dep) then
20249
20250 -- If a subprogram in the incomplete dependents list is primitive
20251 -- for a tagged full type then mark it as a dispatching operation,
20252 -- check whether it overrides an inherited subprogram, and check
20253 -- restrictions on its controlling formals. Note that a protected
20254 -- operation is never dispatching: only its wrapper operation
20255 -- (which has convention Ada) is.
20256
20257 if Is_Tagged_Type (Full_T)
20258 and then Is_Primitive (Priv_Dep)
20259 and then Convention (Priv_Dep) /= Convention_Protected
20260 then
20261 Check_Operation_From_Incomplete_Type (Priv_Dep, Inc_T);
20262 Set_Is_Dispatching_Operation (Priv_Dep);
20263 Check_Controlling_Formals (Full_T, Priv_Dep);
20264 end if;
20265
20266 elsif Ekind (Priv_Dep) = E_Subprogram_Body then
20267
20268 -- Can happen during processing of a body before the completion
20269 -- of a TA type. Ignore, because spec is also on dependent list.
20270
20271 return;
20272
20273 -- Ada 2005 (AI-412): Transform a regular incomplete subtype into a
20274 -- corresponding subtype of the full view.
20275
20276 elsif Ekind (Priv_Dep) = E_Incomplete_Subtype then
20277 Set_Subtype_Indication
20278 (Parent (Priv_Dep), New_Occurrence_Of (Full_T, Sloc (Priv_Dep)));
20279 Set_Etype (Priv_Dep, Full_T);
20280 Set_Ekind (Priv_Dep, Subtype_Kind (Ekind (Full_T)));
20281 Set_Analyzed (Parent (Priv_Dep), False);
20282
20283 -- Reanalyze the declaration, suppressing the call to
20284 -- Enter_Name to avoid duplicate names.
20285
20286 Analyze_Subtype_Declaration
20287 (N => Parent (Priv_Dep),
20288 Skip => True);
20289
20290 -- Dependent is a subtype
20291
20292 else
20293 -- We build a new subtype indication using the full view of the
20294 -- incomplete parent. The discriminant constraints have been
20295 -- elaborated already at the point of the subtype declaration.
20296
20297 New_Subt := Create_Itype (E_Void, N);
20298
20299 if Has_Discriminants (Full_T) then
20300 Disc_Constraint := Discriminant_Constraint (Priv_Dep);
20301 else
20302 Disc_Constraint := No_Elist;
20303 end if;
20304
20305 Build_Discriminated_Subtype (Full_T, New_Subt, Disc_Constraint, N);
20306 Set_Full_View (Priv_Dep, New_Subt);
20307 end if;
20308
20309 Next_Elmt (Inc_Elmt);
20310 end loop;
20311 end Process_Incomplete_Dependents;
20312
20313 --------------------------------
20314 -- Process_Range_Expr_In_Decl --
20315 --------------------------------
20316
20317 procedure Process_Range_Expr_In_Decl
20318 (R : Node_Id;
20319 T : Entity_Id;
20320 Subtyp : Entity_Id := Empty;
20321 Check_List : List_Id := Empty_List;
20322 R_Check_Off : Boolean := False;
20323 In_Iter_Schm : Boolean := False)
20324 is
20325 Lo, Hi : Node_Id;
20326 R_Checks : Check_Result;
20327 Insert_Node : Node_Id;
20328 Def_Id : Entity_Id;
20329
20330 begin
20331 Analyze_And_Resolve (R, Base_Type (T));
20332
20333 if Nkind (R) = N_Range then
20334
20335 -- In SPARK, all ranges should be static, with the exception of the
20336 -- discrete type definition of a loop parameter specification.
20337
20338 if not In_Iter_Schm
20339 and then not Is_OK_Static_Range (R)
20340 then
20341 Check_SPARK_05_Restriction ("range should be static", R);
20342 end if;
20343
20344 Lo := Low_Bound (R);
20345 Hi := High_Bound (R);
20346
20347 -- Validity checks on the range of a quantified expression are
20348 -- delayed until the construct is transformed into a loop.
20349
20350 if Nkind (Parent (R)) = N_Loop_Parameter_Specification
20351 and then Nkind (Parent (Parent (R))) = N_Quantified_Expression
20352 then
20353 null;
20354
20355 -- We need to ensure validity of the bounds here, because if we
20356 -- go ahead and do the expansion, then the expanded code will get
20357 -- analyzed with range checks suppressed and we miss the check.
20358
20359 -- WARNING: The capture of the range bounds with xxx_FIRST/_LAST and
20360 -- the temporaries generated by routine Remove_Side_Effects by means
20361 -- of validity checks must use the same names. When a range appears
20362 -- in the parent of a generic, the range is processed with checks
20363 -- disabled as part of the generic context and with checks enabled
20364 -- for code generation purposes. This leads to link issues as the
20365 -- generic contains references to xxx_FIRST/_LAST, but the inlined
20366 -- template sees the temporaries generated by Remove_Side_Effects.
20367
20368 else
20369 Validity_Check_Range (R, Subtyp);
20370 end if;
20371
20372 -- If there were errors in the declaration, try and patch up some
20373 -- common mistakes in the bounds. The cases handled are literals
20374 -- which are Integer where the expected type is Real and vice versa.
20375 -- These corrections allow the compilation process to proceed further
20376 -- along since some basic assumptions of the format of the bounds
20377 -- are guaranteed.
20378
20379 if Etype (R) = Any_Type then
20380 if Nkind (Lo) = N_Integer_Literal and then Is_Real_Type (T) then
20381 Rewrite (Lo,
20382 Make_Real_Literal (Sloc (Lo), UR_From_Uint (Intval (Lo))));
20383
20384 elsif Nkind (Hi) = N_Integer_Literal and then Is_Real_Type (T) then
20385 Rewrite (Hi,
20386 Make_Real_Literal (Sloc (Hi), UR_From_Uint (Intval (Hi))));
20387
20388 elsif Nkind (Lo) = N_Real_Literal and then Is_Integer_Type (T) then
20389 Rewrite (Lo,
20390 Make_Integer_Literal (Sloc (Lo), UR_To_Uint (Realval (Lo))));
20391
20392 elsif Nkind (Hi) = N_Real_Literal and then Is_Integer_Type (T) then
20393 Rewrite (Hi,
20394 Make_Integer_Literal (Sloc (Hi), UR_To_Uint (Realval (Hi))));
20395 end if;
20396
20397 Set_Etype (Lo, T);
20398 Set_Etype (Hi, T);
20399 end if;
20400
20401 -- If the bounds of the range have been mistakenly given as string
20402 -- literals (perhaps in place of character literals), then an error
20403 -- has already been reported, but we rewrite the string literal as a
20404 -- bound of the range's type to avoid blowups in later processing
20405 -- that looks at static values.
20406
20407 if Nkind (Lo) = N_String_Literal then
20408 Rewrite (Lo,
20409 Make_Attribute_Reference (Sloc (Lo),
20410 Prefix => New_Occurrence_Of (T, Sloc (Lo)),
20411 Attribute_Name => Name_First));
20412 Analyze_And_Resolve (Lo);
20413 end if;
20414
20415 if Nkind (Hi) = N_String_Literal then
20416 Rewrite (Hi,
20417 Make_Attribute_Reference (Sloc (Hi),
20418 Prefix => New_Occurrence_Of (T, Sloc (Hi)),
20419 Attribute_Name => Name_First));
20420 Analyze_And_Resolve (Hi);
20421 end if;
20422
20423 -- If bounds aren't scalar at this point then exit, avoiding
20424 -- problems with further processing of the range in this procedure.
20425
20426 if not Is_Scalar_Type (Etype (Lo)) then
20427 return;
20428 end if;
20429
20430 -- Resolve (actually Sem_Eval) has checked that the bounds are in
20431 -- then range of the base type. Here we check whether the bounds
20432 -- are in the range of the subtype itself. Note that if the bounds
20433 -- represent the null range the Constraint_Error exception should
20434 -- not be raised.
20435
20436 -- ??? The following code should be cleaned up as follows
20437
20438 -- 1. The Is_Null_Range (Lo, Hi) test should disappear since it
20439 -- is done in the call to Range_Check (R, T); below
20440
20441 -- 2. The use of R_Check_Off should be investigated and possibly
20442 -- removed, this would clean up things a bit.
20443
20444 if Is_Null_Range (Lo, Hi) then
20445 null;
20446
20447 else
20448 -- Capture values of bounds and generate temporaries for them
20449 -- if needed, before applying checks, since checks may cause
20450 -- duplication of the expression without forcing evaluation.
20451
20452 -- The forced evaluation removes side effects from expressions,
20453 -- which should occur also in GNATprove mode. Otherwise, we end up
20454 -- with unexpected insertions of actions at places where this is
20455 -- not supposed to occur, e.g. on default parameters of a call.
20456
20457 if Expander_Active or GNATprove_Mode then
20458
20459 -- Call Force_Evaluation to create declarations as needed to
20460 -- deal with side effects, and also create typ_FIRST/LAST
20461 -- entities for bounds if we have a subtype name.
20462
20463 -- Note: we do this transformation even if expansion is not
20464 -- active if we are in GNATprove_Mode since the transformation
20465 -- is in general required to ensure that the resulting tree has
20466 -- proper Ada semantics.
20467
20468 Force_Evaluation
20469 (Lo, Related_Id => Subtyp, Is_Low_Bound => True);
20470 Force_Evaluation
20471 (Hi, Related_Id => Subtyp, Is_High_Bound => True);
20472 end if;
20473
20474 -- We use a flag here instead of suppressing checks on the type
20475 -- because the type we check against isn't necessarily the place
20476 -- where we put the check.
20477
20478 if not R_Check_Off then
20479 R_Checks := Get_Range_Checks (R, T);
20480
20481 -- Look up tree to find an appropriate insertion point. We
20482 -- can't just use insert_actions because later processing
20483 -- depends on the insertion node. Prior to Ada 2012 the
20484 -- insertion point could only be a declaration or a loop, but
20485 -- quantified expressions can appear within any context in an
20486 -- expression, and the insertion point can be any statement,
20487 -- pragma, or declaration.
20488
20489 Insert_Node := Parent (R);
20490 while Present (Insert_Node) loop
20491 exit when
20492 Nkind (Insert_Node) in N_Declaration
20493 and then
20494 not Nkind_In
20495 (Insert_Node, N_Component_Declaration,
20496 N_Loop_Parameter_Specification,
20497 N_Function_Specification,
20498 N_Procedure_Specification);
20499
20500 exit when Nkind (Insert_Node) in N_Later_Decl_Item
20501 or else Nkind (Insert_Node) in
20502 N_Statement_Other_Than_Procedure_Call
20503 or else Nkind_In (Insert_Node, N_Procedure_Call_Statement,
20504 N_Pragma);
20505
20506 Insert_Node := Parent (Insert_Node);
20507 end loop;
20508
20509 -- Why would Type_Decl not be present??? Without this test,
20510 -- short regression tests fail.
20511
20512 if Present (Insert_Node) then
20513
20514 -- Case of loop statement. Verify that the range is part
20515 -- of the subtype indication of the iteration scheme.
20516
20517 if Nkind (Insert_Node) = N_Loop_Statement then
20518 declare
20519 Indic : Node_Id;
20520
20521 begin
20522 Indic := Parent (R);
20523 while Present (Indic)
20524 and then Nkind (Indic) /= N_Subtype_Indication
20525 loop
20526 Indic := Parent (Indic);
20527 end loop;
20528
20529 if Present (Indic) then
20530 Def_Id := Etype (Subtype_Mark (Indic));
20531
20532 Insert_Range_Checks
20533 (R_Checks,
20534 Insert_Node,
20535 Def_Id,
20536 Sloc (Insert_Node),
20537 R,
20538 Do_Before => True);
20539 end if;
20540 end;
20541
20542 -- Insertion before a declaration. If the declaration
20543 -- includes discriminants, the list of applicable checks
20544 -- is given by the caller.
20545
20546 elsif Nkind (Insert_Node) in N_Declaration then
20547 Def_Id := Defining_Identifier (Insert_Node);
20548
20549 if (Ekind (Def_Id) = E_Record_Type
20550 and then Depends_On_Discriminant (R))
20551 or else
20552 (Ekind (Def_Id) = E_Protected_Type
20553 and then Has_Discriminants (Def_Id))
20554 then
20555 Append_Range_Checks
20556 (R_Checks,
20557 Check_List, Def_Id, Sloc (Insert_Node), R);
20558
20559 else
20560 Insert_Range_Checks
20561 (R_Checks,
20562 Insert_Node, Def_Id, Sloc (Insert_Node), R);
20563
20564 end if;
20565
20566 -- Insertion before a statement. Range appears in the
20567 -- context of a quantified expression. Insertion will
20568 -- take place when expression is expanded.
20569
20570 else
20571 null;
20572 end if;
20573 end if;
20574 end if;
20575 end if;
20576
20577 -- Case of other than an explicit N_Range node
20578
20579 -- The forced evaluation removes side effects from expressions, which
20580 -- should occur also in GNATprove mode. Otherwise, we end up with
20581 -- unexpected insertions of actions at places where this is not
20582 -- supposed to occur, e.g. on default parameters of a call.
20583
20584 elsif Expander_Active or GNATprove_Mode then
20585 Get_Index_Bounds (R, Lo, Hi);
20586 Force_Evaluation (Lo);
20587 Force_Evaluation (Hi);
20588 end if;
20589 end Process_Range_Expr_In_Decl;
20590
20591 --------------------------------------
20592 -- Process_Real_Range_Specification --
20593 --------------------------------------
20594
20595 procedure Process_Real_Range_Specification (Def : Node_Id) is
20596 Spec : constant Node_Id := Real_Range_Specification (Def);
20597 Lo : Node_Id;
20598 Hi : Node_Id;
20599 Err : Boolean := False;
20600
20601 procedure Analyze_Bound (N : Node_Id);
20602 -- Analyze and check one bound
20603
20604 -------------------
20605 -- Analyze_Bound --
20606 -------------------
20607
20608 procedure Analyze_Bound (N : Node_Id) is
20609 begin
20610 Analyze_And_Resolve (N, Any_Real);
20611
20612 if not Is_OK_Static_Expression (N) then
20613 Flag_Non_Static_Expr
20614 ("bound in real type definition is not static!", N);
20615 Err := True;
20616 end if;
20617 end Analyze_Bound;
20618
20619 -- Start of processing for Process_Real_Range_Specification
20620
20621 begin
20622 if Present (Spec) then
20623 Lo := Low_Bound (Spec);
20624 Hi := High_Bound (Spec);
20625 Analyze_Bound (Lo);
20626 Analyze_Bound (Hi);
20627
20628 -- If error, clear away junk range specification
20629
20630 if Err then
20631 Set_Real_Range_Specification (Def, Empty);
20632 end if;
20633 end if;
20634 end Process_Real_Range_Specification;
20635
20636 ---------------------
20637 -- Process_Subtype --
20638 ---------------------
20639
20640 function Process_Subtype
20641 (S : Node_Id;
20642 Related_Nod : Node_Id;
20643 Related_Id : Entity_Id := Empty;
20644 Suffix : Character := ' ') return Entity_Id
20645 is
20646 P : Node_Id;
20647 Def_Id : Entity_Id;
20648 Error_Node : Node_Id;
20649 Full_View_Id : Entity_Id;
20650 Subtype_Mark_Id : Entity_Id;
20651
20652 May_Have_Null_Exclusion : Boolean;
20653
20654 procedure Check_Incomplete (T : Node_Id);
20655 -- Called to verify that an incomplete type is not used prematurely
20656
20657 ----------------------
20658 -- Check_Incomplete --
20659 ----------------------
20660
20661 procedure Check_Incomplete (T : Node_Id) is
20662 begin
20663 -- Ada 2005 (AI-412): Incomplete subtypes are legal
20664
20665 if Ekind (Root_Type (Entity (T))) = E_Incomplete_Type
20666 and then
20667 not (Ada_Version >= Ada_2005
20668 and then
20669 (Nkind (Parent (T)) = N_Subtype_Declaration
20670 or else (Nkind (Parent (T)) = N_Subtype_Indication
20671 and then Nkind (Parent (Parent (T))) =
20672 N_Subtype_Declaration)))
20673 then
20674 Error_Msg_N ("invalid use of type before its full declaration", T);
20675 end if;
20676 end Check_Incomplete;
20677
20678 -- Start of processing for Process_Subtype
20679
20680 begin
20681 -- Case of no constraints present
20682
20683 if Nkind (S) /= N_Subtype_Indication then
20684 Find_Type (S);
20685 Check_Incomplete (S);
20686 P := Parent (S);
20687
20688 -- Ada 2005 (AI-231): Static check
20689
20690 if Ada_Version >= Ada_2005
20691 and then Present (P)
20692 and then Null_Exclusion_Present (P)
20693 and then Nkind (P) /= N_Access_To_Object_Definition
20694 and then not Is_Access_Type (Entity (S))
20695 then
20696 Error_Msg_N ("`NOT NULL` only allowed for an access type", S);
20697 end if;
20698
20699 -- The following is ugly, can't we have a range or even a flag???
20700
20701 May_Have_Null_Exclusion :=
20702 Nkind_In (P, N_Access_Definition,
20703 N_Access_Function_Definition,
20704 N_Access_Procedure_Definition,
20705 N_Access_To_Object_Definition,
20706 N_Allocator,
20707 N_Component_Definition)
20708 or else
20709 Nkind_In (P, N_Derived_Type_Definition,
20710 N_Discriminant_Specification,
20711 N_Formal_Object_Declaration,
20712 N_Object_Declaration,
20713 N_Object_Renaming_Declaration,
20714 N_Parameter_Specification,
20715 N_Subtype_Declaration);
20716
20717 -- Create an Itype that is a duplicate of Entity (S) but with the
20718 -- null-exclusion attribute.
20719
20720 if May_Have_Null_Exclusion
20721 and then Is_Access_Type (Entity (S))
20722 and then Null_Exclusion_Present (P)
20723
20724 -- No need to check the case of an access to object definition.
20725 -- It is correct to define double not-null pointers.
20726
20727 -- Example:
20728 -- type Not_Null_Int_Ptr is not null access Integer;
20729 -- type Acc is not null access Not_Null_Int_Ptr;
20730
20731 and then Nkind (P) /= N_Access_To_Object_Definition
20732 then
20733 if Can_Never_Be_Null (Entity (S)) then
20734 case Nkind (Related_Nod) is
20735 when N_Full_Type_Declaration =>
20736 if Nkind (Type_Definition (Related_Nod))
20737 in N_Array_Type_Definition
20738 then
20739 Error_Node :=
20740 Subtype_Indication
20741 (Component_Definition
20742 (Type_Definition (Related_Nod)));
20743 else
20744 Error_Node :=
20745 Subtype_Indication (Type_Definition (Related_Nod));
20746 end if;
20747
20748 when N_Subtype_Declaration =>
20749 Error_Node := Subtype_Indication (Related_Nod);
20750
20751 when N_Object_Declaration =>
20752 Error_Node := Object_Definition (Related_Nod);
20753
20754 when N_Component_Declaration =>
20755 Error_Node :=
20756 Subtype_Indication (Component_Definition (Related_Nod));
20757
20758 when N_Allocator =>
20759 Error_Node := Expression (Related_Nod);
20760
20761 when others =>
20762 pragma Assert (False);
20763 Error_Node := Related_Nod;
20764 end case;
20765
20766 Error_Msg_NE
20767 ("`NOT NULL` not allowed (& already excludes null)",
20768 Error_Node,
20769 Entity (S));
20770 end if;
20771
20772 Set_Etype (S,
20773 Create_Null_Excluding_Itype
20774 (T => Entity (S),
20775 Related_Nod => P));
20776 Set_Entity (S, Etype (S));
20777 end if;
20778
20779 return Entity (S);
20780
20781 -- Case of constraint present, so that we have an N_Subtype_Indication
20782 -- node (this node is created only if constraints are present).
20783
20784 else
20785 Find_Type (Subtype_Mark (S));
20786
20787 if Nkind (Parent (S)) /= N_Access_To_Object_Definition
20788 and then not
20789 (Nkind (Parent (S)) = N_Subtype_Declaration
20790 and then Is_Itype (Defining_Identifier (Parent (S))))
20791 then
20792 Check_Incomplete (Subtype_Mark (S));
20793 end if;
20794
20795 P := Parent (S);
20796 Subtype_Mark_Id := Entity (Subtype_Mark (S));
20797
20798 -- Explicit subtype declaration case
20799
20800 if Nkind (P) = N_Subtype_Declaration then
20801 Def_Id := Defining_Identifier (P);
20802
20803 -- Explicit derived type definition case
20804
20805 elsif Nkind (P) = N_Derived_Type_Definition then
20806 Def_Id := Defining_Identifier (Parent (P));
20807
20808 -- Implicit case, the Def_Id must be created as an implicit type.
20809 -- The one exception arises in the case of concurrent types, array
20810 -- and access types, where other subsidiary implicit types may be
20811 -- created and must appear before the main implicit type. In these
20812 -- cases we leave Def_Id set to Empty as a signal that Create_Itype
20813 -- has not yet been called to create Def_Id.
20814
20815 else
20816 if Is_Array_Type (Subtype_Mark_Id)
20817 or else Is_Concurrent_Type (Subtype_Mark_Id)
20818 or else Is_Access_Type (Subtype_Mark_Id)
20819 then
20820 Def_Id := Empty;
20821
20822 -- For the other cases, we create a new unattached Itype,
20823 -- and set the indication to ensure it gets attached later.
20824
20825 else
20826 Def_Id :=
20827 Create_Itype (E_Void, Related_Nod, Related_Id, Suffix);
20828 end if;
20829 end if;
20830
20831 -- If the kind of constraint is invalid for this kind of type,
20832 -- then give an error, and then pretend no constraint was given.
20833
20834 if not Is_Valid_Constraint_Kind
20835 (Ekind (Subtype_Mark_Id), Nkind (Constraint (S)))
20836 then
20837 Error_Msg_N
20838 ("incorrect constraint for this kind of type", Constraint (S));
20839
20840 Rewrite (S, New_Copy_Tree (Subtype_Mark (S)));
20841
20842 -- Set Ekind of orphan itype, to prevent cascaded errors
20843
20844 if Present (Def_Id) then
20845 Set_Ekind (Def_Id, Ekind (Any_Type));
20846 end if;
20847
20848 -- Make recursive call, having got rid of the bogus constraint
20849
20850 return Process_Subtype (S, Related_Nod, Related_Id, Suffix);
20851 end if;
20852
20853 -- Remaining processing depends on type. Select on Base_Type kind to
20854 -- ensure getting to the concrete type kind in the case of a private
20855 -- subtype (needed when only doing semantic analysis).
20856
20857 case Ekind (Base_Type (Subtype_Mark_Id)) is
20858 when Access_Kind =>
20859
20860 -- If this is a constraint on a class-wide type, discard it.
20861 -- There is currently no way to express a partial discriminant
20862 -- constraint on a type with unknown discriminants. This is
20863 -- a pathology that the ACATS wisely decides not to test.
20864
20865 if Is_Class_Wide_Type (Designated_Type (Subtype_Mark_Id)) then
20866 if Comes_From_Source (S) then
20867 Error_Msg_N
20868 ("constraint on class-wide type ignored??",
20869 Constraint (S));
20870 end if;
20871
20872 if Nkind (P) = N_Subtype_Declaration then
20873 Set_Subtype_Indication (P,
20874 New_Occurrence_Of (Subtype_Mark_Id, Sloc (S)));
20875 end if;
20876
20877 return Subtype_Mark_Id;
20878 end if;
20879
20880 Constrain_Access (Def_Id, S, Related_Nod);
20881
20882 if Expander_Active
20883 and then Is_Itype (Designated_Type (Def_Id))
20884 and then Nkind (Related_Nod) = N_Subtype_Declaration
20885 and then not Is_Incomplete_Type (Designated_Type (Def_Id))
20886 then
20887 Build_Itype_Reference
20888 (Designated_Type (Def_Id), Related_Nod);
20889 end if;
20890
20891 when Array_Kind =>
20892 Constrain_Array (Def_Id, S, Related_Nod, Related_Id, Suffix);
20893
20894 when Decimal_Fixed_Point_Kind =>
20895 Constrain_Decimal (Def_Id, S);
20896
20897 when Enumeration_Kind =>
20898 Constrain_Enumeration (Def_Id, S);
20899 Inherit_Predicate_Flags (Def_Id, Subtype_Mark_Id);
20900
20901 when Ordinary_Fixed_Point_Kind =>
20902 Constrain_Ordinary_Fixed (Def_Id, S);
20903
20904 when Float_Kind =>
20905 Constrain_Float (Def_Id, S);
20906
20907 when Integer_Kind =>
20908 Constrain_Integer (Def_Id, S);
20909 Inherit_Predicate_Flags (Def_Id, Subtype_Mark_Id);
20910
20911 when E_Record_Type |
20912 E_Record_Subtype |
20913 Class_Wide_Kind |
20914 E_Incomplete_Type =>
20915 Constrain_Discriminated_Type (Def_Id, S, Related_Nod);
20916
20917 if Ekind (Def_Id) = E_Incomplete_Type then
20918 Set_Private_Dependents (Def_Id, New_Elmt_List);
20919 end if;
20920
20921 when Private_Kind =>
20922 Constrain_Discriminated_Type (Def_Id, S, Related_Nod);
20923
20924 -- The base type may be private but Def_Id may be a full view
20925 -- in an instance.
20926
20927 if Is_Private_Type (Def_Id) then
20928 Set_Private_Dependents (Def_Id, New_Elmt_List);
20929 end if;
20930
20931 -- In case of an invalid constraint prevent further processing
20932 -- since the type constructed is missing expected fields.
20933
20934 if Etype (Def_Id) = Any_Type then
20935 return Def_Id;
20936 end if;
20937
20938 -- If the full view is that of a task with discriminants,
20939 -- we must constrain both the concurrent type and its
20940 -- corresponding record type. Otherwise we will just propagate
20941 -- the constraint to the full view, if available.
20942
20943 if Present (Full_View (Subtype_Mark_Id))
20944 and then Has_Discriminants (Subtype_Mark_Id)
20945 and then Is_Concurrent_Type (Full_View (Subtype_Mark_Id))
20946 then
20947 Full_View_Id :=
20948 Create_Itype (E_Void, Related_Nod, Related_Id, Suffix);
20949
20950 Set_Entity (Subtype_Mark (S), Full_View (Subtype_Mark_Id));
20951 Constrain_Concurrent (Full_View_Id, S,
20952 Related_Nod, Related_Id, Suffix);
20953 Set_Entity (Subtype_Mark (S), Subtype_Mark_Id);
20954 Set_Full_View (Def_Id, Full_View_Id);
20955
20956 -- Introduce an explicit reference to the private subtype,
20957 -- to prevent scope anomalies in gigi if first use appears
20958 -- in a nested context, e.g. a later function body.
20959 -- Should this be generated in other contexts than a full
20960 -- type declaration?
20961
20962 if Is_Itype (Def_Id)
20963 and then
20964 Nkind (Parent (P)) = N_Full_Type_Declaration
20965 then
20966 Build_Itype_Reference (Def_Id, Parent (P));
20967 end if;
20968
20969 else
20970 Prepare_Private_Subtype_Completion (Def_Id, Related_Nod);
20971 end if;
20972
20973 when Concurrent_Kind =>
20974 Constrain_Concurrent (Def_Id, S,
20975 Related_Nod, Related_Id, Suffix);
20976
20977 when others =>
20978 Error_Msg_N ("invalid subtype mark in subtype indication", S);
20979 end case;
20980
20981 -- Size and Convention are always inherited from the base type
20982
20983 Set_Size_Info (Def_Id, (Subtype_Mark_Id));
20984 Set_Convention (Def_Id, Convention (Subtype_Mark_Id));
20985
20986 return Def_Id;
20987 end if;
20988 end Process_Subtype;
20989
20990 --------------------------------------------
20991 -- Propagate_Default_Init_Cond_Attributes --
20992 --------------------------------------------
20993
20994 procedure Propagate_Default_Init_Cond_Attributes
20995 (From_Typ : Entity_Id;
20996 To_Typ : Entity_Id;
20997 Parent_To_Derivation : Boolean := False;
20998 Private_To_Full_View : Boolean := False)
20999 is
21000 procedure Remove_Default_Init_Cond_Procedure (Typ : Entity_Id);
21001 -- Remove the default initial condition procedure (if any) from the
21002 -- Subprograms_For_Type chain of type Typ.
21003
21004 ----------------------------------------
21005 -- Remove_Default_Init_Cond_Procedure --
21006 ----------------------------------------
21007
21008 procedure Remove_Default_Init_Cond_Procedure (Typ : Entity_Id) is
21009 Subps : constant Elist_Id := Subprograms_For_Type (Typ);
21010 Subp_Elmt : Elmt_Id;
21011 Subp_Id : Entity_Id;
21012
21013 begin
21014 if Present (Subps) then
21015 Subp_Elmt := First_Elmt (Subps);
21016 while Present (Subp_Elmt) loop
21017 Subp_Id := Node (Subp_Elmt);
21018
21019 if Is_Default_Init_Cond_Procedure (Subp_Id) then
21020 Remove_Elmt (Subps, Subp_Elmt);
21021 exit;
21022 end if;
21023
21024 Next_Elmt (Subp_Elmt);
21025 end loop;
21026 end if;
21027 end Remove_Default_Init_Cond_Procedure;
21028
21029 -- Local variables
21030
21031 Inherit_Procedure : Boolean := False;
21032
21033 -- Start of processing for Propagate_Default_Init_Cond_Attributes
21034
21035 begin
21036 if Has_Default_Init_Cond (From_Typ) then
21037
21038 -- A derived type inherits the attributes from its parent type
21039
21040 if Parent_To_Derivation then
21041 Set_Has_Inherited_Default_Init_Cond (To_Typ);
21042
21043 -- A full view shares the attributes with its private view
21044
21045 else
21046 Set_Has_Default_Init_Cond (To_Typ);
21047 end if;
21048
21049 Inherit_Procedure := True;
21050
21051 -- Due to the order of expansion, a derived private type is processed
21052 -- by two routines which both attempt to set the attributes related
21053 -- to pragma Default_Initial_Condition - Build_Derived_Type and then
21054 -- Process_Full_View.
21055
21056 -- package Pack is
21057 -- type Parent_Typ is private
21058 -- with Default_Initial_Condition ...;
21059 -- private
21060 -- type Parent_Typ is ...;
21061 -- end Pack;
21062
21063 -- with Pack; use Pack;
21064 -- package Pack_2 is
21065 -- type Deriv_Typ is private
21066 -- with Default_Initial_Condition ...;
21067 -- private
21068 -- type Deriv_Typ is new Parent_Typ;
21069 -- end Pack_2;
21070
21071 -- When Build_Derived_Type operates, it sets the attributes on the
21072 -- full view without taking into account that the private view may
21073 -- define its own default initial condition procedure. This becomes
21074 -- apparent in Process_Full_View which must undo some of the work by
21075 -- Build_Derived_Type and propagate the attributes from the private
21076 -- to the full view.
21077
21078 if Private_To_Full_View then
21079 Set_Has_Inherited_Default_Init_Cond (To_Typ, False);
21080 Remove_Default_Init_Cond_Procedure (To_Typ);
21081 end if;
21082
21083 -- A type must inherit the default initial condition procedure from a
21084 -- parent type when the parent itself is inheriting the procedure or
21085 -- when it is defining one. This circuitry is also used when dealing
21086 -- with the private / full view of a type.
21087
21088 elsif Has_Inherited_Default_Init_Cond (From_Typ)
21089 or (Parent_To_Derivation
21090 and Present (Get_Pragma
21091 (From_Typ, Pragma_Default_Initial_Condition)))
21092 then
21093 Set_Has_Inherited_Default_Init_Cond (To_Typ);
21094 Inherit_Procedure := True;
21095 end if;
21096
21097 if Inherit_Procedure
21098 and then No (Default_Init_Cond_Procedure (To_Typ))
21099 then
21100 Set_Default_Init_Cond_Procedure
21101 (To_Typ, Default_Init_Cond_Procedure (From_Typ));
21102 end if;
21103 end Propagate_Default_Init_Cond_Attributes;
21104
21105 -----------------------------
21106 -- Record_Type_Declaration --
21107 -----------------------------
21108
21109 procedure Record_Type_Declaration
21110 (T : Entity_Id;
21111 N : Node_Id;
21112 Prev : Entity_Id)
21113 is
21114 Def : constant Node_Id := Type_Definition (N);
21115 Is_Tagged : Boolean;
21116 Tag_Comp : Entity_Id;
21117
21118 begin
21119 -- These flags must be initialized before calling Process_Discriminants
21120 -- because this routine makes use of them.
21121
21122 Set_Ekind (T, E_Record_Type);
21123 Set_Etype (T, T);
21124 Init_Size_Align (T);
21125 Set_Interfaces (T, No_Elist);
21126 Set_Stored_Constraint (T, No_Elist);
21127 Set_Default_SSO (T);
21128
21129 -- Normal case
21130
21131 if Ada_Version < Ada_2005 or else not Interface_Present (Def) then
21132 if Limited_Present (Def) then
21133 Check_SPARK_05_Restriction ("limited is not allowed", N);
21134 end if;
21135
21136 if Abstract_Present (Def) then
21137 Check_SPARK_05_Restriction ("abstract is not allowed", N);
21138 end if;
21139
21140 -- The flag Is_Tagged_Type might have already been set by
21141 -- Find_Type_Name if it detected an error for declaration T. This
21142 -- arises in the case of private tagged types where the full view
21143 -- omits the word tagged.
21144
21145 Is_Tagged :=
21146 Tagged_Present (Def)
21147 or else (Serious_Errors_Detected > 0 and then Is_Tagged_Type (T));
21148
21149 Set_Is_Limited_Record (T, Limited_Present (Def));
21150
21151 if Is_Tagged then
21152 Set_Is_Tagged_Type (T, True);
21153 Set_No_Tagged_Streams_Pragma (T, No_Tagged_Streams);
21154 end if;
21155
21156 -- Type is abstract if full declaration carries keyword, or if
21157 -- previous partial view did.
21158
21159 Set_Is_Abstract_Type (T, Is_Abstract_Type (T)
21160 or else Abstract_Present (Def));
21161
21162 else
21163 Check_SPARK_05_Restriction ("interface is not allowed", N);
21164
21165 Is_Tagged := True;
21166 Analyze_Interface_Declaration (T, Def);
21167
21168 if Present (Discriminant_Specifications (N)) then
21169 Error_Msg_N
21170 ("interface types cannot have discriminants",
21171 Defining_Identifier
21172 (First (Discriminant_Specifications (N))));
21173 end if;
21174 end if;
21175
21176 -- First pass: if there are self-referential access components,
21177 -- create the required anonymous access type declarations, and if
21178 -- need be an incomplete type declaration for T itself.
21179
21180 Check_Anonymous_Access_Components (N, T, Prev, Component_List (Def));
21181
21182 if Ada_Version >= Ada_2005
21183 and then Present (Interface_List (Def))
21184 then
21185 Check_Interfaces (N, Def);
21186
21187 declare
21188 Ifaces_List : Elist_Id;
21189
21190 begin
21191 -- Ada 2005 (AI-251): Collect the list of progenitors that are not
21192 -- already in the parents.
21193
21194 Collect_Interfaces
21195 (T => T,
21196 Ifaces_List => Ifaces_List,
21197 Exclude_Parents => True);
21198
21199 Set_Interfaces (T, Ifaces_List);
21200 end;
21201 end if;
21202
21203 -- Records constitute a scope for the component declarations within.
21204 -- The scope is created prior to the processing of these declarations.
21205 -- Discriminants are processed first, so that they are visible when
21206 -- processing the other components. The Ekind of the record type itself
21207 -- is set to E_Record_Type (subtypes appear as E_Record_Subtype).
21208
21209 -- Enter record scope
21210
21211 Push_Scope (T);
21212
21213 -- If an incomplete or private type declaration was already given for
21214 -- the type, then this scope already exists, and the discriminants have
21215 -- been declared within. We must verify that the full declaration
21216 -- matches the incomplete one.
21217
21218 Check_Or_Process_Discriminants (N, T, Prev);
21219
21220 Set_Is_Constrained (T, not Has_Discriminants (T));
21221 Set_Has_Delayed_Freeze (T, True);
21222
21223 -- For tagged types add a manually analyzed component corresponding
21224 -- to the component _tag, the corresponding piece of tree will be
21225 -- expanded as part of the freezing actions if it is not a CPP_Class.
21226
21227 if Is_Tagged then
21228
21229 -- Do not add the tag unless we are in expansion mode
21230
21231 if Expander_Active then
21232 Tag_Comp := Make_Defining_Identifier (Sloc (Def), Name_uTag);
21233 Enter_Name (Tag_Comp);
21234
21235 Set_Ekind (Tag_Comp, E_Component);
21236 Set_Is_Tag (Tag_Comp);
21237 Set_Is_Aliased (Tag_Comp);
21238 Set_Etype (Tag_Comp, RTE (RE_Tag));
21239 Set_DT_Entry_Count (Tag_Comp, No_Uint);
21240 Set_Original_Record_Component (Tag_Comp, Tag_Comp);
21241 Init_Component_Location (Tag_Comp);
21242
21243 -- Ada 2005 (AI-251): Addition of the Tag corresponding to all the
21244 -- implemented interfaces.
21245
21246 if Has_Interfaces (T) then
21247 Add_Interface_Tag_Components (N, T);
21248 end if;
21249 end if;
21250
21251 Make_Class_Wide_Type (T);
21252 Set_Direct_Primitive_Operations (T, New_Elmt_List);
21253 end if;
21254
21255 -- We must suppress range checks when processing record components in
21256 -- the presence of discriminants, since we don't want spurious checks to
21257 -- be generated during their analysis, but Suppress_Range_Checks flags
21258 -- must be reset the after processing the record definition.
21259
21260 -- Note: this is the only use of Kill_Range_Checks, and is a bit odd,
21261 -- couldn't we just use the normal range check suppression method here.
21262 -- That would seem cleaner ???
21263
21264 if Has_Discriminants (T) and then not Range_Checks_Suppressed (T) then
21265 Set_Kill_Range_Checks (T, True);
21266 Record_Type_Definition (Def, Prev);
21267 Set_Kill_Range_Checks (T, False);
21268 else
21269 Record_Type_Definition (Def, Prev);
21270 end if;
21271
21272 -- Exit from record scope
21273
21274 End_Scope;
21275
21276 -- Ada 2005 (AI-251 and AI-345): Derive the interface subprograms of all
21277 -- the implemented interfaces and associate them an aliased entity.
21278
21279 if Is_Tagged
21280 and then not Is_Empty_List (Interface_List (Def))
21281 then
21282 Derive_Progenitor_Subprograms (T, T);
21283 end if;
21284
21285 Check_Function_Writable_Actuals (N);
21286 end Record_Type_Declaration;
21287
21288 ----------------------------
21289 -- Record_Type_Definition --
21290 ----------------------------
21291
21292 procedure Record_Type_Definition (Def : Node_Id; Prev_T : Entity_Id) is
21293 Component : Entity_Id;
21294 Ctrl_Components : Boolean := False;
21295 Final_Storage_Only : Boolean;
21296 T : Entity_Id;
21297
21298 begin
21299 if Ekind (Prev_T) = E_Incomplete_Type then
21300 T := Full_View (Prev_T);
21301 else
21302 T := Prev_T;
21303 end if;
21304
21305 -- In SPARK, tagged types and type extensions may only be declared in
21306 -- the specification of library unit packages.
21307
21308 if Present (Def) and then Is_Tagged_Type (T) then
21309 declare
21310 Typ : Node_Id;
21311 Ctxt : Node_Id;
21312
21313 begin
21314 if Nkind (Parent (Def)) = N_Full_Type_Declaration then
21315 Typ := Parent (Def);
21316 else
21317 pragma Assert
21318 (Nkind (Parent (Def)) = N_Derived_Type_Definition);
21319 Typ := Parent (Parent (Def));
21320 end if;
21321
21322 Ctxt := Parent (Typ);
21323
21324 if Nkind (Ctxt) = N_Package_Body
21325 and then Nkind (Parent (Ctxt)) = N_Compilation_Unit
21326 then
21327 Check_SPARK_05_Restriction
21328 ("type should be defined in package specification", Typ);
21329
21330 elsif Nkind (Ctxt) /= N_Package_Specification
21331 or else Nkind (Parent (Parent (Ctxt))) /= N_Compilation_Unit
21332 then
21333 Check_SPARK_05_Restriction
21334 ("type should be defined in library unit package", Typ);
21335 end if;
21336 end;
21337 end if;
21338
21339 Final_Storage_Only := not Is_Controlled_Active (T);
21340
21341 -- Ada 2005: Check whether an explicit Limited is present in a derived
21342 -- type declaration.
21343
21344 if Nkind (Parent (Def)) = N_Derived_Type_Definition
21345 and then Limited_Present (Parent (Def))
21346 then
21347 Set_Is_Limited_Record (T);
21348 end if;
21349
21350 -- If the component list of a record type is defined by the reserved
21351 -- word null and there is no discriminant part, then the record type has
21352 -- no components and all records of the type are null records (RM 3.7)
21353 -- This procedure is also called to process the extension part of a
21354 -- record extension, in which case the current scope may have inherited
21355 -- components.
21356
21357 if No (Def)
21358 or else No (Component_List (Def))
21359 or else Null_Present (Component_List (Def))
21360 then
21361 if not Is_Tagged_Type (T) then
21362 Check_SPARK_05_Restriction ("untagged record cannot be null", Def);
21363 end if;
21364
21365 else
21366 Analyze_Declarations (Component_Items (Component_List (Def)));
21367
21368 if Present (Variant_Part (Component_List (Def))) then
21369 Check_SPARK_05_Restriction ("variant part is not allowed", Def);
21370 Analyze (Variant_Part (Component_List (Def)));
21371 end if;
21372 end if;
21373
21374 -- After completing the semantic analysis of the record definition,
21375 -- record components, both new and inherited, are accessible. Set their
21376 -- kind accordingly. Exclude malformed itypes from illegal declarations,
21377 -- whose Ekind may be void.
21378
21379 Component := First_Entity (Current_Scope);
21380 while Present (Component) loop
21381 if Ekind (Component) = E_Void
21382 and then not Is_Itype (Component)
21383 then
21384 Set_Ekind (Component, E_Component);
21385 Init_Component_Location (Component);
21386 end if;
21387
21388 Propagate_Concurrent_Flags (T, Etype (Component));
21389
21390 if Ekind (Component) /= E_Component then
21391 null;
21392
21393 -- Do not set Has_Controlled_Component on a class-wide equivalent
21394 -- type. See Make_CW_Equivalent_Type.
21395
21396 elsif not Is_Class_Wide_Equivalent_Type (T)
21397 and then (Has_Controlled_Component (Etype (Component))
21398 or else (Chars (Component) /= Name_uParent
21399 and then Is_Controlled_Active
21400 (Etype (Component))))
21401 then
21402 Set_Has_Controlled_Component (T, True);
21403 Final_Storage_Only :=
21404 Final_Storage_Only
21405 and then Finalize_Storage_Only (Etype (Component));
21406 Ctrl_Components := True;
21407 end if;
21408
21409 Next_Entity (Component);
21410 end loop;
21411
21412 -- A Type is Finalize_Storage_Only only if all its controlled components
21413 -- are also.
21414
21415 if Ctrl_Components then
21416 Set_Finalize_Storage_Only (T, Final_Storage_Only);
21417 end if;
21418
21419 -- Place reference to end record on the proper entity, which may
21420 -- be a partial view.
21421
21422 if Present (Def) then
21423 Process_End_Label (Def, 'e', Prev_T);
21424 end if;
21425 end Record_Type_Definition;
21426
21427 ------------------------
21428 -- Replace_Components --
21429 ------------------------
21430
21431 procedure Replace_Components (Typ : Entity_Id; Decl : Node_Id) is
21432 function Process (N : Node_Id) return Traverse_Result;
21433
21434 -------------
21435 -- Process --
21436 -------------
21437
21438 function Process (N : Node_Id) return Traverse_Result is
21439 Comp : Entity_Id;
21440
21441 begin
21442 if Nkind (N) = N_Discriminant_Specification then
21443 Comp := First_Discriminant (Typ);
21444 while Present (Comp) loop
21445 if Chars (Comp) = Chars (Defining_Identifier (N)) then
21446 Set_Defining_Identifier (N, Comp);
21447 exit;
21448 end if;
21449
21450 Next_Discriminant (Comp);
21451 end loop;
21452
21453 elsif Nkind (N) = N_Component_Declaration then
21454 Comp := First_Component (Typ);
21455 while Present (Comp) loop
21456 if Chars (Comp) = Chars (Defining_Identifier (N)) then
21457 Set_Defining_Identifier (N, Comp);
21458 exit;
21459 end if;
21460
21461 Next_Component (Comp);
21462 end loop;
21463 end if;
21464
21465 return OK;
21466 end Process;
21467
21468 procedure Replace is new Traverse_Proc (Process);
21469
21470 -- Start of processing for Replace_Components
21471
21472 begin
21473 Replace (Decl);
21474 end Replace_Components;
21475
21476 -------------------------------
21477 -- Set_Completion_Referenced --
21478 -------------------------------
21479
21480 procedure Set_Completion_Referenced (E : Entity_Id) is
21481 begin
21482 -- If in main unit, mark entity that is a completion as referenced,
21483 -- warnings go on the partial view when needed.
21484
21485 if In_Extended_Main_Source_Unit (E) then
21486 Set_Referenced (E);
21487 end if;
21488 end Set_Completion_Referenced;
21489
21490 ---------------------
21491 -- Set_Default_SSO --
21492 ---------------------
21493
21494 procedure Set_Default_SSO (T : Entity_Id) is
21495 begin
21496 case Opt.Default_SSO is
21497 when ' ' =>
21498 null;
21499 when 'L' =>
21500 Set_SSO_Set_Low_By_Default (T, True);
21501 when 'H' =>
21502 Set_SSO_Set_High_By_Default (T, True);
21503 when others =>
21504 raise Program_Error;
21505 end case;
21506 end Set_Default_SSO;
21507
21508 ---------------------
21509 -- Set_Fixed_Range --
21510 ---------------------
21511
21512 -- The range for fixed-point types is complicated by the fact that we
21513 -- do not know the exact end points at the time of the declaration. This
21514 -- is true for three reasons:
21515
21516 -- A size clause may affect the fudging of the end-points.
21517 -- A small clause may affect the values of the end-points.
21518 -- We try to include the end-points if it does not affect the size.
21519
21520 -- This means that the actual end-points must be established at the
21521 -- point when the type is frozen. Meanwhile, we first narrow the range
21522 -- as permitted (so that it will fit if necessary in a small specified
21523 -- size), and then build a range subtree with these narrowed bounds.
21524 -- Set_Fixed_Range constructs the range from real literal values, and
21525 -- sets the range as the Scalar_Range of the given fixed-point type entity.
21526
21527 -- The parent of this range is set to point to the entity so that it is
21528 -- properly hooked into the tree (unlike normal Scalar_Range entries for
21529 -- other scalar types, which are just pointers to the range in the
21530 -- original tree, this would otherwise be an orphan).
21531
21532 -- The tree is left unanalyzed. When the type is frozen, the processing
21533 -- in Freeze.Freeze_Fixed_Point_Type notices that the range is not
21534 -- analyzed, and uses this as an indication that it should complete
21535 -- work on the range (it will know the final small and size values).
21536
21537 procedure Set_Fixed_Range
21538 (E : Entity_Id;
21539 Loc : Source_Ptr;
21540 Lo : Ureal;
21541 Hi : Ureal)
21542 is
21543 S : constant Node_Id :=
21544 Make_Range (Loc,
21545 Low_Bound => Make_Real_Literal (Loc, Lo),
21546 High_Bound => Make_Real_Literal (Loc, Hi));
21547 begin
21548 Set_Scalar_Range (E, S);
21549 Set_Parent (S, E);
21550
21551 -- Before the freeze point, the bounds of a fixed point are universal
21552 -- and carry the corresponding type.
21553
21554 Set_Etype (Low_Bound (S), Universal_Real);
21555 Set_Etype (High_Bound (S), Universal_Real);
21556 end Set_Fixed_Range;
21557
21558 ----------------------------------
21559 -- Set_Scalar_Range_For_Subtype --
21560 ----------------------------------
21561
21562 procedure Set_Scalar_Range_For_Subtype
21563 (Def_Id : Entity_Id;
21564 R : Node_Id;
21565 Subt : Entity_Id)
21566 is
21567 Kind : constant Entity_Kind := Ekind (Def_Id);
21568
21569 begin
21570 -- Defend against previous error
21571
21572 if Nkind (R) = N_Error then
21573 return;
21574 end if;
21575
21576 Set_Scalar_Range (Def_Id, R);
21577
21578 -- We need to link the range into the tree before resolving it so
21579 -- that types that are referenced, including importantly the subtype
21580 -- itself, are properly frozen (Freeze_Expression requires that the
21581 -- expression be properly linked into the tree). Of course if it is
21582 -- already linked in, then we do not disturb the current link.
21583
21584 if No (Parent (R)) then
21585 Set_Parent (R, Def_Id);
21586 end if;
21587
21588 -- Reset the kind of the subtype during analysis of the range, to
21589 -- catch possible premature use in the bounds themselves.
21590
21591 Set_Ekind (Def_Id, E_Void);
21592 Process_Range_Expr_In_Decl (R, Subt, Subtyp => Def_Id);
21593 Set_Ekind (Def_Id, Kind);
21594 end Set_Scalar_Range_For_Subtype;
21595
21596 --------------------------------------------------------
21597 -- Set_Stored_Constraint_From_Discriminant_Constraint --
21598 --------------------------------------------------------
21599
21600 procedure Set_Stored_Constraint_From_Discriminant_Constraint
21601 (E : Entity_Id)
21602 is
21603 begin
21604 -- Make sure set if encountered during Expand_To_Stored_Constraint
21605
21606 Set_Stored_Constraint (E, No_Elist);
21607
21608 -- Give it the right value
21609
21610 if Is_Constrained (E) and then Has_Discriminants (E) then
21611 Set_Stored_Constraint (E,
21612 Expand_To_Stored_Constraint (E, Discriminant_Constraint (E)));
21613 end if;
21614 end Set_Stored_Constraint_From_Discriminant_Constraint;
21615
21616 -------------------------------------
21617 -- Signed_Integer_Type_Declaration --
21618 -------------------------------------
21619
21620 procedure Signed_Integer_Type_Declaration (T : Entity_Id; Def : Node_Id) is
21621 Implicit_Base : Entity_Id;
21622 Base_Typ : Entity_Id;
21623 Lo_Val : Uint;
21624 Hi_Val : Uint;
21625 Errs : Boolean := False;
21626 Lo : Node_Id;
21627 Hi : Node_Id;
21628
21629 function Can_Derive_From (E : Entity_Id) return Boolean;
21630 -- Determine whether given bounds allow derivation from specified type
21631
21632 procedure Check_Bound (Expr : Node_Id);
21633 -- Check bound to make sure it is integral and static. If not, post
21634 -- appropriate error message and set Errs flag
21635
21636 ---------------------
21637 -- Can_Derive_From --
21638 ---------------------
21639
21640 -- Note we check both bounds against both end values, to deal with
21641 -- strange types like ones with a range of 0 .. -12341234.
21642
21643 function Can_Derive_From (E : Entity_Id) return Boolean is
21644 Lo : constant Uint := Expr_Value (Type_Low_Bound (E));
21645 Hi : constant Uint := Expr_Value (Type_High_Bound (E));
21646 begin
21647 return Lo <= Lo_Val and then Lo_Val <= Hi
21648 and then
21649 Lo <= Hi_Val and then Hi_Val <= Hi;
21650 end Can_Derive_From;
21651
21652 -----------------
21653 -- Check_Bound --
21654 -----------------
21655
21656 procedure Check_Bound (Expr : Node_Id) is
21657 begin
21658 -- If a range constraint is used as an integer type definition, each
21659 -- bound of the range must be defined by a static expression of some
21660 -- integer type, but the two bounds need not have the same integer
21661 -- type (Negative bounds are allowed.) (RM 3.5.4)
21662
21663 if not Is_Integer_Type (Etype (Expr)) then
21664 Error_Msg_N
21665 ("integer type definition bounds must be of integer type", Expr);
21666 Errs := True;
21667
21668 elsif not Is_OK_Static_Expression (Expr) then
21669 Flag_Non_Static_Expr
21670 ("non-static expression used for integer type bound!", Expr);
21671 Errs := True;
21672
21673 -- The bounds are folded into literals, and we set their type to be
21674 -- universal, to avoid typing difficulties: we cannot set the type
21675 -- of the literal to the new type, because this would be a forward
21676 -- reference for the back end, and if the original type is user-
21677 -- defined this can lead to spurious semantic errors (e.g. 2928-003).
21678
21679 else
21680 if Is_Entity_Name (Expr) then
21681 Fold_Uint (Expr, Expr_Value (Expr), True);
21682 end if;
21683
21684 Set_Etype (Expr, Universal_Integer);
21685 end if;
21686 end Check_Bound;
21687
21688 -- Start of processing for Signed_Integer_Type_Declaration
21689
21690 begin
21691 -- Create an anonymous base type
21692
21693 Implicit_Base :=
21694 Create_Itype (E_Signed_Integer_Type, Parent (Def), T, 'B');
21695
21696 -- Analyze and check the bounds, they can be of any integer type
21697
21698 Lo := Low_Bound (Def);
21699 Hi := High_Bound (Def);
21700
21701 -- Arbitrarily use Integer as the type if either bound had an error
21702
21703 if Hi = Error or else Lo = Error then
21704 Base_Typ := Any_Integer;
21705 Set_Error_Posted (T, True);
21706
21707 -- Here both bounds are OK expressions
21708
21709 else
21710 Analyze_And_Resolve (Lo, Any_Integer);
21711 Analyze_And_Resolve (Hi, Any_Integer);
21712
21713 Check_Bound (Lo);
21714 Check_Bound (Hi);
21715
21716 if Errs then
21717 Hi := Type_High_Bound (Standard_Long_Long_Integer);
21718 Lo := Type_Low_Bound (Standard_Long_Long_Integer);
21719 end if;
21720
21721 -- Find type to derive from
21722
21723 Lo_Val := Expr_Value (Lo);
21724 Hi_Val := Expr_Value (Hi);
21725
21726 if Can_Derive_From (Standard_Short_Short_Integer) then
21727 Base_Typ := Base_Type (Standard_Short_Short_Integer);
21728
21729 elsif Can_Derive_From (Standard_Short_Integer) then
21730 Base_Typ := Base_Type (Standard_Short_Integer);
21731
21732 elsif Can_Derive_From (Standard_Integer) then
21733 Base_Typ := Base_Type (Standard_Integer);
21734
21735 elsif Can_Derive_From (Standard_Long_Integer) then
21736 Base_Typ := Base_Type (Standard_Long_Integer);
21737
21738 elsif Can_Derive_From (Standard_Long_Long_Integer) then
21739 Check_Restriction (No_Long_Long_Integers, Def);
21740 Base_Typ := Base_Type (Standard_Long_Long_Integer);
21741
21742 else
21743 Base_Typ := Base_Type (Standard_Long_Long_Integer);
21744 Error_Msg_N ("integer type definition bounds out of range", Def);
21745 Hi := Type_High_Bound (Standard_Long_Long_Integer);
21746 Lo := Type_Low_Bound (Standard_Long_Long_Integer);
21747 end if;
21748 end if;
21749
21750 -- Complete both implicit base and declared first subtype entities. The
21751 -- inheritance of the rep item chain ensures that SPARK-related pragmas
21752 -- are not clobbered when the signed integer type acts as a full view of
21753 -- a private type.
21754
21755 Set_Etype (Implicit_Base, Base_Typ);
21756 Set_Size_Info (Implicit_Base, Base_Typ);
21757 Set_RM_Size (Implicit_Base, RM_Size (Base_Typ));
21758 Set_First_Rep_Item (Implicit_Base, First_Rep_Item (Base_Typ));
21759 Set_Scalar_Range (Implicit_Base, Scalar_Range (Base_Typ));
21760
21761 Set_Ekind (T, E_Signed_Integer_Subtype);
21762 Set_Etype (T, Implicit_Base);
21763 Set_Size_Info (T, Implicit_Base);
21764 Inherit_Rep_Item_Chain (T, Implicit_Base);
21765 Set_Scalar_Range (T, Def);
21766 Set_RM_Size (T, UI_From_Int (Minimum_Size (T)));
21767 Set_Is_Constrained (T);
21768 end Signed_Integer_Type_Declaration;
21769
21770 end Sem_Ch3;