File : sem_aggr.adb
1 ------------------------------------------------------------------------------
2 -- --
3 -- GNAT COMPILER COMPONENTS --
4 -- --
5 -- S E M _ A G G R --
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 Einfo; use Einfo;
30 with Elists; use Elists;
31 with Errout; use Errout;
32 with Expander; use Expander;
33 with Exp_Tss; use Exp_Tss;
34 with Exp_Util; use Exp_Util;
35 with Freeze; use Freeze;
36 with Itypes; use Itypes;
37 with Lib; use Lib;
38 with Lib.Xref; use Lib.Xref;
39 with Namet; use Namet;
40 with Namet.Sp; use Namet.Sp;
41 with Nmake; use Nmake;
42 with Nlists; use Nlists;
43 with Opt; use Opt;
44 with Restrict; use Restrict;
45 with Rident; use Rident;
46 with Sem; use Sem;
47 with Sem_Aux; use Sem_Aux;
48 with Sem_Cat; use Sem_Cat;
49 with Sem_Ch3; use Sem_Ch3;
50 with Sem_Ch8; use Sem_Ch8;
51 with Sem_Ch13; use Sem_Ch13;
52 with Sem_Dim; use Sem_Dim;
53 with Sem_Eval; use Sem_Eval;
54 with Sem_Res; use Sem_Res;
55 with Sem_Util; use Sem_Util;
56 with Sem_Type; use Sem_Type;
57 with Sem_Warn; use Sem_Warn;
58 with Sinfo; use Sinfo;
59 with Snames; use Snames;
60 with Stringt; use Stringt;
61 with Stand; use Stand;
62 with Style; use Style;
63 with Targparm; use Targparm;
64 with Tbuild; use Tbuild;
65 with Uintp; use Uintp;
66
67 package body Sem_Aggr is
68
69 type Case_Bounds is record
70 Lo : Node_Id;
71 -- Low bound of choice. Once we sort the Case_Table, then entries
72 -- will be in order of ascending Choice_Lo values.
73
74 Hi : Node_Id;
75 -- High Bound of choice. The sort does not pay any attention to the
76 -- high bound, so choices 1 .. 4 and 1 .. 5 could be in either order.
77
78 Highest : Uint;
79 -- If there are duplicates or missing entries, then in the sorted
80 -- table, this records the highest value among Choice_Hi values
81 -- seen so far, including this entry.
82
83 Choice : Node_Id;
84 -- The node of the choice
85 end record;
86
87 type Case_Table_Type is array (Nat range <>) of Case_Bounds;
88 -- Table type used by Check_Case_Choices procedure. Entry zero is not
89 -- used (reserved for the sort). Real entries start at one.
90
91 -----------------------
92 -- Local Subprograms --
93 -----------------------
94
95 procedure Sort_Case_Table (Case_Table : in out Case_Table_Type);
96 -- Sort the Case Table using the Lower Bound of each Choice as the key. A
97 -- simple insertion sort is used since the choices in a case statement will
98 -- usually be in near sorted order.
99
100 procedure Check_Can_Never_Be_Null (Typ : Entity_Id; Expr : Node_Id);
101 -- Ada 2005 (AI-231): Check bad usage of null for a component for which
102 -- null exclusion (NOT NULL) is specified. Typ can be an E_Array_Type for
103 -- the array case (the component type of the array will be used) or an
104 -- E_Component/E_Discriminant entity in the record case, in which case the
105 -- type of the component will be used for the test. If Typ is any other
106 -- kind of entity, the call is ignored. Expr is the component node in the
107 -- aggregate which is known to have a null value. A warning message will be
108 -- issued if the component is null excluding.
109 --
110 -- It would be better to pass the proper type for Typ ???
111
112 procedure Check_Expr_OK_In_Limited_Aggregate (Expr : Node_Id);
113 -- Check that Expr is either not limited or else is one of the cases of
114 -- expressions allowed for a limited component association (namely, an
115 -- aggregate, function call, or <> notation). Report error for violations.
116 -- Expression is also OK in an instance or inlining context, because we
117 -- have already pre-analyzed and it is known to be type correct.
118
119 procedure Check_Qualified_Aggregate (Level : Nat; Expr : Node_Id);
120 -- Given aggregate Expr, check that sub-aggregates of Expr that are nested
121 -- at Level are qualified. If Level = 0, this applies to Expr directly.
122 -- Only issue errors in formal verification mode.
123
124 function Is_Top_Level_Aggregate (Expr : Node_Id) return Boolean;
125 -- Return True of Expr is an aggregate not contained directly in another
126 -- aggregate.
127
128 ------------------------------------------------------
129 -- Subprograms used for RECORD AGGREGATE Processing --
130 ------------------------------------------------------
131
132 procedure Resolve_Record_Aggregate (N : Node_Id; Typ : Entity_Id);
133 -- This procedure performs all the semantic checks required for record
134 -- aggregates. Note that for aggregates analysis and resolution go
135 -- hand in hand. Aggregate analysis has been delayed up to here and
136 -- it is done while resolving the aggregate.
137 --
138 -- N is the N_Aggregate node.
139 -- Typ is the record type for the aggregate resolution
140 --
141 -- While performing the semantic checks, this procedure builds a new
142 -- Component_Association_List where each record field appears alone in a
143 -- Component_Choice_List along with its corresponding expression. The
144 -- record fields in the Component_Association_List appear in the same order
145 -- in which they appear in the record type Typ.
146 --
147 -- Once this new Component_Association_List is built and all the semantic
148 -- checks performed, the original aggregate subtree is replaced with the
149 -- new named record aggregate just built. Note that subtree substitution is
150 -- performed with Rewrite so as to be able to retrieve the original
151 -- aggregate.
152 --
153 -- The aggregate subtree manipulation performed by Resolve_Record_Aggregate
154 -- yields the aggregate format expected by Gigi. Typically, this kind of
155 -- tree manipulations are done in the expander. However, because the
156 -- semantic checks that need to be performed on record aggregates really go
157 -- hand in hand with the record aggregate normalization, the aggregate
158 -- subtree transformation is performed during resolution rather than
159 -- expansion. Had we decided otherwise we would have had to duplicate most
160 -- of the code in the expansion procedure Expand_Record_Aggregate. Note,
161 -- however, that all the expansion concerning aggregates for tagged records
162 -- is done in Expand_Record_Aggregate.
163 --
164 -- The algorithm of Resolve_Record_Aggregate proceeds as follows:
165 --
166 -- 1. Make sure that the record type against which the record aggregate
167 -- has to be resolved is not abstract. Furthermore if the type is a
168 -- null aggregate make sure the input aggregate N is also null.
169 --
170 -- 2. Verify that the structure of the aggregate is that of a record
171 -- aggregate. Specifically, look for component associations and ensure
172 -- that each choice list only has identifiers or the N_Others_Choice
173 -- node. Also make sure that if present, the N_Others_Choice occurs
174 -- last and by itself.
175 --
176 -- 3. If Typ contains discriminants, the values for each discriminant is
177 -- looked for. If the record type Typ has variants, we check that the
178 -- expressions corresponding to each discriminant ruling the (possibly
179 -- nested) variant parts of Typ, are static. This allows us to determine
180 -- the variant parts to which the rest of the aggregate must conform.
181 -- The names of discriminants with their values are saved in a new
182 -- association list, New_Assoc_List which is later augmented with the
183 -- names and values of the remaining components in the record type.
184 --
185 -- During this phase we also make sure that every discriminant is
186 -- assigned exactly one value. Note that when several values for a given
187 -- discriminant are found, semantic processing continues looking for
188 -- further errors. In this case it's the first discriminant value found
189 -- which we will be recorded.
190 --
191 -- IMPORTANT NOTE: For derived tagged types this procedure expects
192 -- First_Discriminant and Next_Discriminant to give the correct list
193 -- of discriminants, in the correct order.
194 --
195 -- 4. After all the discriminant values have been gathered, we can set the
196 -- Etype of the record aggregate. If Typ contains no discriminants this
197 -- is straightforward: the Etype of N is just Typ, otherwise a new
198 -- implicit constrained subtype of Typ is built to be the Etype of N.
199 --
200 -- 5. Gather the remaining record components according to the discriminant
201 -- values. This involves recursively traversing the record type
202 -- structure to see what variants are selected by the given discriminant
203 -- values. This processing is a little more convoluted if Typ is a
204 -- derived tagged types since we need to retrieve the record structure
205 -- of all the ancestors of Typ.
206 --
207 -- 6. After gathering the record components we look for their values in the
208 -- record aggregate and emit appropriate error messages should we not
209 -- find such values or should they be duplicated.
210 --
211 -- 7. We then make sure no illegal component names appear in the record
212 -- aggregate and make sure that the type of the record components
213 -- appearing in a same choice list is the same. Finally we ensure that
214 -- the others choice, if present, is used to provide the value of at
215 -- least a record component.
216 --
217 -- 8. The original aggregate node is replaced with the new named aggregate
218 -- built in steps 3 through 6, as explained earlier.
219 --
220 -- Given the complexity of record aggregate resolution, the primary goal of
221 -- this routine is clarity and simplicity rather than execution and storage
222 -- efficiency. If there are only positional components in the aggregate the
223 -- running time is linear. If there are associations the running time is
224 -- still linear as long as the order of the associations is not too far off
225 -- the order of the components in the record type. If this is not the case
226 -- the running time is at worst quadratic in the size of the association
227 -- list.
228
229 procedure Check_Misspelled_Component
230 (Elements : Elist_Id;
231 Component : Node_Id);
232 -- Give possible misspelling diagnostic if Component is likely to be a
233 -- misspelling of one of the components of the Assoc_List. This is called
234 -- by Resolve_Aggr_Expr after producing an invalid component error message.
235
236 procedure Check_Static_Discriminated_Subtype (T : Entity_Id; V : Node_Id);
237 -- An optimization: determine whether a discriminated subtype has a static
238 -- constraint, and contains array components whose length is also static,
239 -- either because they are constrained by the discriminant, or because the
240 -- original component bounds are static.
241
242 -----------------------------------------------------
243 -- Subprograms used for ARRAY AGGREGATE Processing --
244 -----------------------------------------------------
245
246 function Resolve_Array_Aggregate
247 (N : Node_Id;
248 Index : Node_Id;
249 Index_Constr : Node_Id;
250 Component_Typ : Entity_Id;
251 Others_Allowed : Boolean) return Boolean;
252 -- This procedure performs the semantic checks for an array aggregate.
253 -- True is returned if the aggregate resolution succeeds.
254 --
255 -- The procedure works by recursively checking each nested aggregate.
256 -- Specifically, after checking a sub-aggregate nested at the i-th level
257 -- we recursively check all the subaggregates at the i+1-st level (if any).
258 -- Note that for aggregates analysis and resolution go hand in hand.
259 -- Aggregate analysis has been delayed up to here and it is done while
260 -- resolving the aggregate.
261 --
262 -- N is the current N_Aggregate node to be checked.
263 --
264 -- Index is the index node corresponding to the array sub-aggregate that
265 -- we are currently checking (RM 4.3.3 (8)). Its Etype is the
266 -- corresponding index type (or subtype).
267 --
268 -- Index_Constr is the node giving the applicable index constraint if
269 -- any (RM 4.3.3 (10)). It "is a constraint provided by certain
270 -- contexts [...] that can be used to determine the bounds of the array
271 -- value specified by the aggregate". If Others_Allowed below is False
272 -- there is no applicable index constraint and this node is set to Index.
273 --
274 -- Component_Typ is the array component type.
275 --
276 -- Others_Allowed indicates whether an others choice is allowed
277 -- in the context where the top-level aggregate appeared.
278 --
279 -- The algorithm of Resolve_Array_Aggregate proceeds as follows:
280 --
281 -- 1. Make sure that the others choice, if present, is by itself and
282 -- appears last in the sub-aggregate. Check that we do not have
283 -- positional and named components in the array sub-aggregate (unless
284 -- the named association is an others choice). Finally if an others
285 -- choice is present, make sure it is allowed in the aggregate context.
286 --
287 -- 2. If the array sub-aggregate contains discrete_choices:
288 --
289 -- (A) Verify their validity. Specifically verify that:
290 --
291 -- (a) If a null range is present it must be the only possible
292 -- choice in the array aggregate.
293 --
294 -- (b) Ditto for a non static range.
295 --
296 -- (c) Ditto for a non static expression.
297 --
298 -- In addition this step analyzes and resolves each discrete_choice,
299 -- making sure that its type is the type of the corresponding Index.
300 -- If we are not at the lowest array aggregate level (in the case of
301 -- multi-dimensional aggregates) then invoke Resolve_Array_Aggregate
302 -- recursively on each component expression. Otherwise, resolve the
303 -- bottom level component expressions against the expected component
304 -- type ONLY IF the component corresponds to a single discrete choice
305 -- which is not an others choice (to see why read the DELAYED
306 -- COMPONENT RESOLUTION below).
307 --
308 -- (B) Determine the bounds of the sub-aggregate and lowest and
309 -- highest choice values.
310 --
311 -- 3. For positional aggregates:
312 --
313 -- (A) Loop over the component expressions either recursively invoking
314 -- Resolve_Array_Aggregate on each of these for multi-dimensional
315 -- array aggregates or resolving the bottom level component
316 -- expressions against the expected component type.
317 --
318 -- (B) Determine the bounds of the positional sub-aggregates.
319 --
320 -- 4. Try to determine statically whether the evaluation of the array
321 -- sub-aggregate raises Constraint_Error. If yes emit proper
322 -- warnings. The precise checks are the following:
323 --
324 -- (A) Check that the index range defined by aggregate bounds is
325 -- compatible with corresponding index subtype.
326 -- We also check against the base type. In fact it could be that
327 -- Low/High bounds of the base type are static whereas those of
328 -- the index subtype are not. Thus if we can statically catch
329 -- a problem with respect to the base type we are guaranteed
330 -- that the same problem will arise with the index subtype
331 --
332 -- (B) If we are dealing with a named aggregate containing an others
333 -- choice and at least one discrete choice then make sure the range
334 -- specified by the discrete choices does not overflow the
335 -- aggregate bounds. We also check against the index type and base
336 -- type bounds for the same reasons given in (A).
337 --
338 -- (C) If we are dealing with a positional aggregate with an others
339 -- choice make sure the number of positional elements specified
340 -- does not overflow the aggregate bounds. We also check against
341 -- the index type and base type bounds as mentioned in (A).
342 --
343 -- Finally construct an N_Range node giving the sub-aggregate bounds.
344 -- Set the Aggregate_Bounds field of the sub-aggregate to be this
345 -- N_Range. The routine Array_Aggr_Subtype below uses such N_Ranges
346 -- to build the appropriate aggregate subtype. Aggregate_Bounds
347 -- information is needed during expansion.
348 --
349 -- DELAYED COMPONENT RESOLUTION: The resolution of bottom level component
350 -- expressions in an array aggregate may call Duplicate_Subexpr or some
351 -- other routine that inserts code just outside the outermost aggregate.
352 -- If the array aggregate contains discrete choices or an others choice,
353 -- this may be wrong. Consider for instance the following example.
354 --
355 -- type Rec is record
356 -- V : Integer := 0;
357 -- end record;
358 --
359 -- type Acc_Rec is access Rec;
360 -- Arr : array (1..3) of Acc_Rec := (1 .. 3 => new Rec);
361 --
362 -- Then the transformation of "new Rec" that occurs during resolution
363 -- entails the following code modifications
364 --
365 -- P7b : constant Acc_Rec := new Rec;
366 -- RecIP (P7b.all);
367 -- Arr : array (1..3) of Acc_Rec := (1 .. 3 => P7b);
368 --
369 -- This code transformation is clearly wrong, since we need to call
370 -- "new Rec" for each of the 3 array elements. To avoid this problem we
371 -- delay resolution of the components of non positional array aggregates
372 -- to the expansion phase. As an optimization, if the discrete choice
373 -- specifies a single value we do not delay resolution.
374
375 function Array_Aggr_Subtype (N : Node_Id; Typ : Node_Id) return Entity_Id;
376 -- This routine returns the type or subtype of an array aggregate.
377 --
378 -- N is the array aggregate node whose type we return.
379 --
380 -- Typ is the context type in which N occurs.
381 --
382 -- This routine creates an implicit array subtype whose bounds are
383 -- those defined by the aggregate. When this routine is invoked
384 -- Resolve_Array_Aggregate has already processed aggregate N. Thus the
385 -- Aggregate_Bounds of each sub-aggregate, is an N_Range node giving the
386 -- sub-aggregate bounds. When building the aggregate itype, this function
387 -- traverses the array aggregate N collecting such Aggregate_Bounds and
388 -- constructs the proper array aggregate itype.
389 --
390 -- Note that in the case of multidimensional aggregates each inner
391 -- sub-aggregate corresponding to a given array dimension, may provide a
392 -- different bounds. If it is possible to determine statically that
393 -- some sub-aggregates corresponding to the same index do not have the
394 -- same bounds, then a warning is emitted. If such check is not possible
395 -- statically (because some sub-aggregate bounds are dynamic expressions)
396 -- then this job is left to the expander. In all cases the particular
397 -- bounds that this function will chose for a given dimension is the first
398 -- N_Range node for a sub-aggregate corresponding to that dimension.
399 --
400 -- Note that the Raises_Constraint_Error flag of an array aggregate
401 -- whose evaluation is determined to raise CE by Resolve_Array_Aggregate,
402 -- is set in Resolve_Array_Aggregate but the aggregate is not
403 -- immediately replaced with a raise CE. In fact, Array_Aggr_Subtype must
404 -- first construct the proper itype for the aggregate (Gigi needs
405 -- this). After constructing the proper itype we will eventually replace
406 -- the top-level aggregate with a raise CE (done in Resolve_Aggregate).
407 -- Of course in cases such as:
408 --
409 -- type Arr is array (integer range <>) of Integer;
410 -- A : Arr := (positive range -1 .. 2 => 0);
411 --
412 -- The bounds of the aggregate itype are cooked up to look reasonable
413 -- (in this particular case the bounds will be 1 .. 2).
414
415 procedure Make_String_Into_Aggregate (N : Node_Id);
416 -- A string literal can appear in a context in which a one dimensional
417 -- array of characters is expected. This procedure simply rewrites the
418 -- string as an aggregate, prior to resolution.
419
420 ------------------------
421 -- Array_Aggr_Subtype --
422 ------------------------
423
424 function Array_Aggr_Subtype
425 (N : Node_Id;
426 Typ : Entity_Id) return Entity_Id
427 is
428 Aggr_Dimension : constant Pos := Number_Dimensions (Typ);
429 -- Number of aggregate index dimensions
430
431 Aggr_Range : array (1 .. Aggr_Dimension) of Node_Id := (others => Empty);
432 -- Constrained N_Range of each index dimension in our aggregate itype
433
434 Aggr_Low : array (1 .. Aggr_Dimension) of Node_Id := (others => Empty);
435 Aggr_High : array (1 .. Aggr_Dimension) of Node_Id := (others => Empty);
436 -- Low and High bounds for each index dimension in our aggregate itype
437
438 Is_Fully_Positional : Boolean := True;
439
440 procedure Collect_Aggr_Bounds (N : Node_Id; Dim : Pos);
441 -- N is an array (sub-)aggregate. Dim is the dimension corresponding
442 -- to (sub-)aggregate N. This procedure collects and removes the side
443 -- effects of the constrained N_Range nodes corresponding to each index
444 -- dimension of our aggregate itype. These N_Range nodes are collected
445 -- in Aggr_Range above.
446 --
447 -- Likewise collect in Aggr_Low & Aggr_High above the low and high
448 -- bounds of each index dimension. If, when collecting, two bounds
449 -- corresponding to the same dimension are static and found to differ,
450 -- then emit a warning, and mark N as raising Constraint_Error.
451
452 -------------------------
453 -- Collect_Aggr_Bounds --
454 -------------------------
455
456 procedure Collect_Aggr_Bounds (N : Node_Id; Dim : Pos) is
457 This_Range : constant Node_Id := Aggregate_Bounds (N);
458 -- The aggregate range node of this specific sub-aggregate
459
460 This_Low : constant Node_Id := Low_Bound (Aggregate_Bounds (N));
461 This_High : constant Node_Id := High_Bound (Aggregate_Bounds (N));
462 -- The aggregate bounds of this specific sub-aggregate
463
464 Assoc : Node_Id;
465 Expr : Node_Id;
466
467 begin
468 Remove_Side_Effects (This_Low, Variable_Ref => True);
469 Remove_Side_Effects (This_High, Variable_Ref => True);
470
471 -- Collect the first N_Range for a given dimension that you find.
472 -- For a given dimension they must be all equal anyway.
473
474 if No (Aggr_Range (Dim)) then
475 Aggr_Low (Dim) := This_Low;
476 Aggr_High (Dim) := This_High;
477 Aggr_Range (Dim) := This_Range;
478
479 else
480 if Compile_Time_Known_Value (This_Low) then
481 if not Compile_Time_Known_Value (Aggr_Low (Dim)) then
482 Aggr_Low (Dim) := This_Low;
483
484 elsif Expr_Value (This_Low) /= Expr_Value (Aggr_Low (Dim)) then
485 Set_Raises_Constraint_Error (N);
486 Error_Msg_Warn := SPARK_Mode /= On;
487 Error_Msg_N ("sub-aggregate low bound mismatch<<", N);
488 Error_Msg_N ("\Constraint_Error [<<", N);
489 end if;
490 end if;
491
492 if Compile_Time_Known_Value (This_High) then
493 if not Compile_Time_Known_Value (Aggr_High (Dim)) then
494 Aggr_High (Dim) := This_High;
495
496 elsif
497 Expr_Value (This_High) /= Expr_Value (Aggr_High (Dim))
498 then
499 Set_Raises_Constraint_Error (N);
500 Error_Msg_Warn := SPARK_Mode /= On;
501 Error_Msg_N ("sub-aggregate high bound mismatch<<", N);
502 Error_Msg_N ("\Constraint_Error [<<", N);
503 end if;
504 end if;
505 end if;
506
507 if Dim < Aggr_Dimension then
508
509 -- Process positional components
510
511 if Present (Expressions (N)) then
512 Expr := First (Expressions (N));
513 while Present (Expr) loop
514 Collect_Aggr_Bounds (Expr, Dim + 1);
515 Next (Expr);
516 end loop;
517 end if;
518
519 -- Process component associations
520
521 if Present (Component_Associations (N)) then
522 Is_Fully_Positional := False;
523
524 Assoc := First (Component_Associations (N));
525 while Present (Assoc) loop
526 Expr := Expression (Assoc);
527 Collect_Aggr_Bounds (Expr, Dim + 1);
528 Next (Assoc);
529 end loop;
530 end if;
531 end if;
532 end Collect_Aggr_Bounds;
533
534 -- Array_Aggr_Subtype variables
535
536 Itype : Entity_Id;
537 -- The final itype of the overall aggregate
538
539 Index_Constraints : constant List_Id := New_List;
540 -- The list of index constraints of the aggregate itype
541
542 -- Start of processing for Array_Aggr_Subtype
543
544 begin
545 -- Make sure that the list of index constraints is properly attached to
546 -- the tree, and then collect the aggregate bounds.
547
548 Set_Parent (Index_Constraints, N);
549 Collect_Aggr_Bounds (N, 1);
550
551 -- Build the list of constrained indexes of our aggregate itype
552
553 for J in 1 .. Aggr_Dimension loop
554 Create_Index : declare
555 Index_Base : constant Entity_Id :=
556 Base_Type (Etype (Aggr_Range (J)));
557 Index_Typ : Entity_Id;
558
559 begin
560 -- Construct the Index subtype, and associate it with the range
561 -- construct that generates it.
562
563 Index_Typ :=
564 Create_Itype (Subtype_Kind (Ekind (Index_Base)), Aggr_Range (J));
565
566 Set_Etype (Index_Typ, Index_Base);
567
568 if Is_Character_Type (Index_Base) then
569 Set_Is_Character_Type (Index_Typ);
570 end if;
571
572 Set_Size_Info (Index_Typ, (Index_Base));
573 Set_RM_Size (Index_Typ, RM_Size (Index_Base));
574 Set_First_Rep_Item (Index_Typ, First_Rep_Item (Index_Base));
575 Set_Scalar_Range (Index_Typ, Aggr_Range (J));
576
577 if Is_Discrete_Or_Fixed_Point_Type (Index_Typ) then
578 Set_RM_Size (Index_Typ, UI_From_Int (Minimum_Size (Index_Typ)));
579 end if;
580
581 Set_Etype (Aggr_Range (J), Index_Typ);
582
583 Append (Aggr_Range (J), To => Index_Constraints);
584 end Create_Index;
585 end loop;
586
587 -- Now build the Itype
588
589 Itype := Create_Itype (E_Array_Subtype, N);
590
591 Set_First_Rep_Item (Itype, First_Rep_Item (Typ));
592 Set_Convention (Itype, Convention (Typ));
593 Set_Depends_On_Private (Itype, Has_Private_Component (Typ));
594 Set_Etype (Itype, Base_Type (Typ));
595 Set_Has_Alignment_Clause (Itype, Has_Alignment_Clause (Typ));
596 Set_Is_Aliased (Itype, Is_Aliased (Typ));
597 Set_Depends_On_Private (Itype, Depends_On_Private (Typ));
598
599 Copy_Suppress_Status (Index_Check, Typ, Itype);
600 Copy_Suppress_Status (Length_Check, Typ, Itype);
601
602 Set_First_Index (Itype, First (Index_Constraints));
603 Set_Is_Constrained (Itype, True);
604 Set_Is_Internal (Itype, True);
605
606 -- A simple optimization: purely positional aggregates of static
607 -- components should be passed to gigi unexpanded whenever possible, and
608 -- regardless of the staticness of the bounds themselves. Subsequent
609 -- checks in exp_aggr verify that type is not packed, etc.
610
611 Set_Size_Known_At_Compile_Time
612 (Itype,
613 Is_Fully_Positional
614 and then Comes_From_Source (N)
615 and then Size_Known_At_Compile_Time (Component_Type (Typ)));
616
617 -- We always need a freeze node for a packed array subtype, so that we
618 -- can build the Packed_Array_Impl_Type corresponding to the subtype. If
619 -- expansion is disabled, the packed array subtype is not built, and we
620 -- must not generate a freeze node for the type, or else it will appear
621 -- incomplete to gigi.
622
623 if Is_Packed (Itype)
624 and then not In_Spec_Expression
625 and then Expander_Active
626 then
627 Freeze_Itype (Itype, N);
628 end if;
629
630 return Itype;
631 end Array_Aggr_Subtype;
632
633 --------------------------------
634 -- Check_Misspelled_Component --
635 --------------------------------
636
637 procedure Check_Misspelled_Component
638 (Elements : Elist_Id;
639 Component : Node_Id)
640 is
641 Max_Suggestions : constant := 2;
642
643 Nr_Of_Suggestions : Natural := 0;
644 Suggestion_1 : Entity_Id := Empty;
645 Suggestion_2 : Entity_Id := Empty;
646 Component_Elmt : Elmt_Id;
647
648 begin
649 -- All the components of List are matched against Component and a count
650 -- is maintained of possible misspellings. When at the end of the
651 -- analysis there are one or two (not more) possible misspellings,
652 -- these misspellings will be suggested as possible corrections.
653
654 Component_Elmt := First_Elmt (Elements);
655 while Nr_Of_Suggestions <= Max_Suggestions
656 and then Present (Component_Elmt)
657 loop
658 if Is_Bad_Spelling_Of
659 (Chars (Node (Component_Elmt)),
660 Chars (Component))
661 then
662 Nr_Of_Suggestions := Nr_Of_Suggestions + 1;
663
664 case Nr_Of_Suggestions is
665 when 1 => Suggestion_1 := Node (Component_Elmt);
666 when 2 => Suggestion_2 := Node (Component_Elmt);
667 when others => null;
668 end case;
669 end if;
670
671 Next_Elmt (Component_Elmt);
672 end loop;
673
674 -- Report at most two suggestions
675
676 if Nr_Of_Suggestions = 1 then
677 Error_Msg_NE -- CODEFIX
678 ("\possible misspelling of&", Component, Suggestion_1);
679
680 elsif Nr_Of_Suggestions = 2 then
681 Error_Msg_Node_2 := Suggestion_2;
682 Error_Msg_NE -- CODEFIX
683 ("\possible misspelling of& or&", Component, Suggestion_1);
684 end if;
685 end Check_Misspelled_Component;
686
687 ----------------------------------------
688 -- Check_Expr_OK_In_Limited_Aggregate --
689 ----------------------------------------
690
691 procedure Check_Expr_OK_In_Limited_Aggregate (Expr : Node_Id) is
692 begin
693 if Is_Limited_Type (Etype (Expr))
694 and then Comes_From_Source (Expr)
695 then
696 if In_Instance_Body or else In_Inlined_Body then
697 null;
698
699 elsif not OK_For_Limited_Init (Etype (Expr), Expr) then
700 Error_Msg_N
701 ("initialization not allowed for limited types", Expr);
702 Explain_Limited_Type (Etype (Expr), Expr);
703 end if;
704 end if;
705 end Check_Expr_OK_In_Limited_Aggregate;
706
707 -------------------------------
708 -- Check_Qualified_Aggregate --
709 -------------------------------
710
711 procedure Check_Qualified_Aggregate (Level : Nat; Expr : Node_Id) is
712 Comp_Expr : Node_Id;
713 Comp_Assn : Node_Id;
714
715 begin
716 if Level = 0 then
717 if Nkind (Parent (Expr)) /= N_Qualified_Expression then
718 Check_SPARK_05_Restriction ("aggregate should be qualified", Expr);
719 end if;
720
721 else
722 Comp_Expr := First (Expressions (Expr));
723 while Present (Comp_Expr) loop
724 if Nkind (Comp_Expr) = N_Aggregate then
725 Check_Qualified_Aggregate (Level - 1, Comp_Expr);
726 end if;
727
728 Comp_Expr := Next (Comp_Expr);
729 end loop;
730
731 Comp_Assn := First (Component_Associations (Expr));
732 while Present (Comp_Assn) loop
733 Comp_Expr := Expression (Comp_Assn);
734
735 if Nkind (Comp_Expr) = N_Aggregate then
736 Check_Qualified_Aggregate (Level - 1, Comp_Expr);
737 end if;
738
739 Comp_Assn := Next (Comp_Assn);
740 end loop;
741 end if;
742 end Check_Qualified_Aggregate;
743
744 ----------------------------------------
745 -- Check_Static_Discriminated_Subtype --
746 ----------------------------------------
747
748 procedure Check_Static_Discriminated_Subtype (T : Entity_Id; V : Node_Id) is
749 Disc : constant Entity_Id := First_Discriminant (T);
750 Comp : Entity_Id;
751 Ind : Entity_Id;
752
753 begin
754 if Has_Record_Rep_Clause (T) then
755 return;
756
757 elsif Present (Next_Discriminant (Disc)) then
758 return;
759
760 elsif Nkind (V) /= N_Integer_Literal then
761 return;
762 end if;
763
764 Comp := First_Component (T);
765 while Present (Comp) loop
766 if Is_Scalar_Type (Etype (Comp)) then
767 null;
768
769 elsif Is_Private_Type (Etype (Comp))
770 and then Present (Full_View (Etype (Comp)))
771 and then Is_Scalar_Type (Full_View (Etype (Comp)))
772 then
773 null;
774
775 elsif Is_Array_Type (Etype (Comp)) then
776 if Is_Bit_Packed_Array (Etype (Comp)) then
777 return;
778 end if;
779
780 Ind := First_Index (Etype (Comp));
781 while Present (Ind) loop
782 if Nkind (Ind) /= N_Range
783 or else Nkind (Low_Bound (Ind)) /= N_Integer_Literal
784 or else Nkind (High_Bound (Ind)) /= N_Integer_Literal
785 then
786 return;
787 end if;
788
789 Next_Index (Ind);
790 end loop;
791
792 else
793 return;
794 end if;
795
796 Next_Component (Comp);
797 end loop;
798
799 -- On exit, all components have statically known sizes
800
801 Set_Size_Known_At_Compile_Time (T);
802 end Check_Static_Discriminated_Subtype;
803
804 -------------------------
805 -- Is_Others_Aggregate --
806 -------------------------
807
808 function Is_Others_Aggregate (Aggr : Node_Id) return Boolean is
809 begin
810 return No (Expressions (Aggr))
811 and then
812 Nkind (First (Choices (First (Component_Associations (Aggr))))) =
813 N_Others_Choice;
814 end Is_Others_Aggregate;
815
816 ----------------------------
817 -- Is_Top_Level_Aggregate --
818 ----------------------------
819
820 function Is_Top_Level_Aggregate (Expr : Node_Id) return Boolean is
821 begin
822 return Nkind (Parent (Expr)) /= N_Aggregate
823 and then (Nkind (Parent (Expr)) /= N_Component_Association
824 or else Nkind (Parent (Parent (Expr))) /= N_Aggregate);
825 end Is_Top_Level_Aggregate;
826
827 --------------------------------
828 -- Make_String_Into_Aggregate --
829 --------------------------------
830
831 procedure Make_String_Into_Aggregate (N : Node_Id) is
832 Exprs : constant List_Id := New_List;
833 Loc : constant Source_Ptr := Sloc (N);
834 Str : constant String_Id := Strval (N);
835 Strlen : constant Nat := String_Length (Str);
836 C : Char_Code;
837 C_Node : Node_Id;
838 New_N : Node_Id;
839 P : Source_Ptr;
840
841 begin
842 P := Loc + 1;
843 for J in 1 .. Strlen loop
844 C := Get_String_Char (Str, J);
845 Set_Character_Literal_Name (C);
846
847 C_Node :=
848 Make_Character_Literal (P,
849 Chars => Name_Find,
850 Char_Literal_Value => UI_From_CC (C));
851 Set_Etype (C_Node, Any_Character);
852 Append_To (Exprs, C_Node);
853
854 P := P + 1;
855 -- Something special for wide strings???
856 end loop;
857
858 New_N := Make_Aggregate (Loc, Expressions => Exprs);
859 Set_Analyzed (New_N);
860 Set_Etype (New_N, Any_Composite);
861
862 Rewrite (N, New_N);
863 end Make_String_Into_Aggregate;
864
865 -----------------------
866 -- Resolve_Aggregate --
867 -----------------------
868
869 procedure Resolve_Aggregate (N : Node_Id; Typ : Entity_Id) is
870 Loc : constant Source_Ptr := Sloc (N);
871 Pkind : constant Node_Kind := Nkind (Parent (N));
872
873 Aggr_Subtyp : Entity_Id;
874 -- The actual aggregate subtype. This is not necessarily the same as Typ
875 -- which is the subtype of the context in which the aggregate was found.
876
877 begin
878 -- Ignore junk empty aggregate resulting from parser error
879
880 if No (Expressions (N))
881 and then No (Component_Associations (N))
882 and then not Null_Record_Present (N)
883 then
884 return;
885 end if;
886
887 -- If the aggregate has box-initialized components, its type must be
888 -- frozen so that initialization procedures can properly be called
889 -- in the resolution that follows. The replacement of boxes with
890 -- initialization calls is properly an expansion activity but it must
891 -- be done during resolution.
892
893 if Expander_Active
894 and then Present (Component_Associations (N))
895 then
896 declare
897 Comp : Node_Id;
898
899 begin
900 Comp := First (Component_Associations (N));
901 while Present (Comp) loop
902 if Box_Present (Comp) then
903 Insert_Actions (N, Freeze_Entity (Typ, N));
904 exit;
905 end if;
906
907 Next (Comp);
908 end loop;
909 end;
910 end if;
911
912 -- An unqualified aggregate is restricted in SPARK to:
913
914 -- An aggregate item inside an aggregate for a multi-dimensional array
915
916 -- An expression being assigned to an unconstrained array, but only if
917 -- the aggregate specifies a value for OTHERS only.
918
919 if Nkind (Parent (N)) = N_Qualified_Expression then
920 if Is_Array_Type (Typ) then
921 Check_Qualified_Aggregate (Number_Dimensions (Typ), N);
922 else
923 Check_Qualified_Aggregate (1, N);
924 end if;
925 else
926 if Is_Array_Type (Typ)
927 and then Nkind (Parent (N)) = N_Assignment_Statement
928 and then not Is_Constrained (Etype (Name (Parent (N))))
929 then
930 if not Is_Others_Aggregate (N) then
931 Check_SPARK_05_Restriction
932 ("array aggregate should have only OTHERS", N);
933 end if;
934
935 elsif Is_Top_Level_Aggregate (N) then
936 Check_SPARK_05_Restriction ("aggregate should be qualified", N);
937
938 -- The legality of this unqualified aggregate is checked by calling
939 -- Check_Qualified_Aggregate from one of its enclosing aggregate,
940 -- unless one of these already causes an error to be issued.
941
942 else
943 null;
944 end if;
945 end if;
946
947 -- Check for aggregates not allowed in configurable run-time mode.
948 -- We allow all cases of aggregates that do not come from source, since
949 -- these are all assumed to be small (e.g. bounds of a string literal).
950 -- We also allow aggregates of types we know to be small.
951
952 if not Support_Aggregates_On_Target
953 and then Comes_From_Source (N)
954 and then (not Known_Static_Esize (Typ) or else Esize (Typ) > 64)
955 then
956 Error_Msg_CRT ("aggregate", N);
957 end if;
958
959 -- Ada 2005 (AI-287): Limited aggregates allowed
960
961 -- In an instance, ignore aggregate subcomponents tnat may be limited,
962 -- because they originate in view conflicts. If the original aggregate
963 -- is legal and the actuals are legal, the aggregate itself is legal.
964
965 if Is_Limited_Type (Typ)
966 and then Ada_Version < Ada_2005
967 and then not In_Instance
968 then
969 Error_Msg_N ("aggregate type cannot be limited", N);
970 Explain_Limited_Type (Typ, N);
971
972 elsif Is_Class_Wide_Type (Typ) then
973 Error_Msg_N ("type of aggregate cannot be class-wide", N);
974
975 elsif Typ = Any_String
976 or else Typ = Any_Composite
977 then
978 Error_Msg_N ("no unique type for aggregate", N);
979 Set_Etype (N, Any_Composite);
980
981 elsif Is_Array_Type (Typ) and then Null_Record_Present (N) then
982 Error_Msg_N ("null record forbidden in array aggregate", N);
983
984 elsif Is_Record_Type (Typ) then
985 Resolve_Record_Aggregate (N, Typ);
986
987 elsif Is_Array_Type (Typ) then
988
989 -- First a special test, for the case of a positional aggregate
990 -- of characters which can be replaced by a string literal.
991
992 -- Do not perform this transformation if this was a string literal to
993 -- start with, whose components needed constraint checks, or if the
994 -- component type is non-static, because it will require those checks
995 -- and be transformed back into an aggregate.
996
997 if Number_Dimensions (Typ) = 1
998 and then Is_Standard_Character_Type (Component_Type (Typ))
999 and then No (Component_Associations (N))
1000 and then not Is_Limited_Composite (Typ)
1001 and then not Is_Private_Composite (Typ)
1002 and then not Is_Bit_Packed_Array (Typ)
1003 and then Nkind (Original_Node (Parent (N))) /= N_String_Literal
1004 and then Is_OK_Static_Subtype (Component_Type (Typ))
1005 then
1006 declare
1007 Expr : Node_Id;
1008
1009 begin
1010 Expr := First (Expressions (N));
1011 while Present (Expr) loop
1012 exit when Nkind (Expr) /= N_Character_Literal;
1013 Next (Expr);
1014 end loop;
1015
1016 if No (Expr) then
1017 Start_String;
1018
1019 Expr := First (Expressions (N));
1020 while Present (Expr) loop
1021 Store_String_Char (UI_To_CC (Char_Literal_Value (Expr)));
1022 Next (Expr);
1023 end loop;
1024
1025 Rewrite (N, Make_String_Literal (Loc, End_String));
1026
1027 Analyze_And_Resolve (N, Typ);
1028 return;
1029 end if;
1030 end;
1031 end if;
1032
1033 -- Here if we have a real aggregate to deal with
1034
1035 Array_Aggregate : declare
1036 Aggr_Resolved : Boolean;
1037
1038 Aggr_Typ : constant Entity_Id := Etype (Typ);
1039 -- This is the unconstrained array type, which is the type against
1040 -- which the aggregate is to be resolved. Typ itself is the array
1041 -- type of the context which may not be the same subtype as the
1042 -- subtype for the final aggregate.
1043
1044 begin
1045 -- In the following we determine whether an OTHERS choice is
1046 -- allowed inside the array aggregate. The test checks the context
1047 -- in which the array aggregate occurs. If the context does not
1048 -- permit it, or the aggregate type is unconstrained, an OTHERS
1049 -- choice is not allowed (except that it is always allowed on the
1050 -- right-hand side of an assignment statement; in this case the
1051 -- constrainedness of the type doesn't matter).
1052
1053 -- If expansion is disabled (generic context, or semantics-only
1054 -- mode) actual subtypes cannot be constructed, and the type of an
1055 -- object may be its unconstrained nominal type. However, if the
1056 -- context is an assignment, we assume that OTHERS is allowed,
1057 -- because the target of the assignment will have a constrained
1058 -- subtype when fully compiled.
1059
1060 -- Note that there is no node for Explicit_Actual_Parameter.
1061 -- To test for this context we therefore have to test for node
1062 -- N_Parameter_Association which itself appears only if there is a
1063 -- formal parameter. Consequently we also need to test for
1064 -- N_Procedure_Call_Statement or N_Function_Call.
1065
1066 -- The context may be an N_Reference node, created by expansion.
1067 -- Legality of the others clause was established in the source,
1068 -- so the context is legal.
1069
1070 Set_Etype (N, Aggr_Typ); -- May be overridden later on
1071
1072 if Pkind = N_Assignment_Statement
1073 or else (Is_Constrained (Typ)
1074 and then
1075 (Pkind = N_Parameter_Association or else
1076 Pkind = N_Function_Call or else
1077 Pkind = N_Procedure_Call_Statement or else
1078 Pkind = N_Generic_Association or else
1079 Pkind = N_Formal_Object_Declaration or else
1080 Pkind = N_Simple_Return_Statement or else
1081 Pkind = N_Object_Declaration or else
1082 Pkind = N_Component_Declaration or else
1083 Pkind = N_Parameter_Specification or else
1084 Pkind = N_Qualified_Expression or else
1085 Pkind = N_Reference or else
1086 Pkind = N_Aggregate or else
1087 Pkind = N_Extension_Aggregate or else
1088 Pkind = N_Component_Association))
1089 then
1090 Aggr_Resolved :=
1091 Resolve_Array_Aggregate
1092 (N,
1093 Index => First_Index (Aggr_Typ),
1094 Index_Constr => First_Index (Typ),
1095 Component_Typ => Component_Type (Typ),
1096 Others_Allowed => True);
1097 else
1098 Aggr_Resolved :=
1099 Resolve_Array_Aggregate
1100 (N,
1101 Index => First_Index (Aggr_Typ),
1102 Index_Constr => First_Index (Aggr_Typ),
1103 Component_Typ => Component_Type (Typ),
1104 Others_Allowed => False);
1105 end if;
1106
1107 if not Aggr_Resolved then
1108
1109 -- A parenthesized expression may have been intended as an
1110 -- aggregate, leading to a type error when analyzing the
1111 -- component. This can also happen for a nested component
1112 -- (see Analyze_Aggr_Expr).
1113
1114 if Paren_Count (N) > 0 then
1115 Error_Msg_N
1116 ("positional aggregate cannot have one component", N);
1117 end if;
1118
1119 Aggr_Subtyp := Any_Composite;
1120
1121 else
1122 Aggr_Subtyp := Array_Aggr_Subtype (N, Typ);
1123 end if;
1124
1125 Set_Etype (N, Aggr_Subtyp);
1126 end Array_Aggregate;
1127
1128 elsif Is_Private_Type (Typ)
1129 and then Present (Full_View (Typ))
1130 and then (In_Inlined_Body or In_Instance_Body)
1131 and then Is_Composite_Type (Full_View (Typ))
1132 then
1133 Resolve (N, Full_View (Typ));
1134
1135 else
1136 Error_Msg_N ("illegal context for aggregate", N);
1137 end if;
1138
1139 -- If we can determine statically that the evaluation of the aggregate
1140 -- raises Constraint_Error, then replace the aggregate with an
1141 -- N_Raise_Constraint_Error node, but set the Etype to the right
1142 -- aggregate subtype. Gigi needs this.
1143
1144 if Raises_Constraint_Error (N) then
1145 Aggr_Subtyp := Etype (N);
1146 Rewrite (N,
1147 Make_Raise_Constraint_Error (Loc, Reason => CE_Range_Check_Failed));
1148 Set_Raises_Constraint_Error (N);
1149 Set_Etype (N, Aggr_Subtyp);
1150 Set_Analyzed (N);
1151 end if;
1152
1153 Check_Function_Writable_Actuals (N);
1154 end Resolve_Aggregate;
1155
1156 -----------------------------
1157 -- Resolve_Array_Aggregate --
1158 -----------------------------
1159
1160 function Resolve_Array_Aggregate
1161 (N : Node_Id;
1162 Index : Node_Id;
1163 Index_Constr : Node_Id;
1164 Component_Typ : Entity_Id;
1165 Others_Allowed : Boolean) return Boolean
1166 is
1167 Loc : constant Source_Ptr := Sloc (N);
1168
1169 Failure : constant Boolean := False;
1170 Success : constant Boolean := True;
1171
1172 Index_Typ : constant Entity_Id := Etype (Index);
1173 Index_Typ_Low : constant Node_Id := Type_Low_Bound (Index_Typ);
1174 Index_Typ_High : constant Node_Id := Type_High_Bound (Index_Typ);
1175 -- The type of the index corresponding to the array sub-aggregate along
1176 -- with its low and upper bounds.
1177
1178 Index_Base : constant Entity_Id := Base_Type (Index_Typ);
1179 Index_Base_Low : constant Node_Id := Type_Low_Bound (Index_Base);
1180 Index_Base_High : constant Node_Id := Type_High_Bound (Index_Base);
1181 -- Ditto for the base type
1182
1183 function Add (Val : Uint; To : Node_Id) return Node_Id;
1184 -- Creates a new expression node where Val is added to expression To.
1185 -- Tries to constant fold whenever possible. To must be an already
1186 -- analyzed expression.
1187
1188 procedure Check_Bound (BH : Node_Id; AH : in out Node_Id);
1189 -- Checks that AH (the upper bound of an array aggregate) is less than
1190 -- or equal to BH (the upper bound of the index base type). If the check
1191 -- fails, a warning is emitted, the Raises_Constraint_Error flag of N is
1192 -- set, and AH is replaced with a duplicate of BH.
1193
1194 procedure Check_Bounds (L, H : Node_Id; AL, AH : Node_Id);
1195 -- Checks that range AL .. AH is compatible with range L .. H. Emits a
1196 -- warning if not and sets the Raises_Constraint_Error flag in N.
1197
1198 procedure Check_Length (L, H : Node_Id; Len : Uint);
1199 -- Checks that range L .. H contains at least Len elements. Emits a
1200 -- warning if not and sets the Raises_Constraint_Error flag in N.
1201
1202 function Dynamic_Or_Null_Range (L, H : Node_Id) return Boolean;
1203 -- Returns True if range L .. H is dynamic or null
1204
1205 procedure Get (Value : out Uint; From : Node_Id; OK : out Boolean);
1206 -- Given expression node From, this routine sets OK to False if it
1207 -- cannot statically evaluate From. Otherwise it stores this static
1208 -- value into Value.
1209
1210 function Resolve_Aggr_Expr
1211 (Expr : Node_Id;
1212 Single_Elmt : Boolean) return Boolean;
1213 -- Resolves aggregate expression Expr. Returns False if resolution
1214 -- fails. If Single_Elmt is set to False, the expression Expr may be
1215 -- used to initialize several array aggregate elements (this can happen
1216 -- for discrete choices such as "L .. H => Expr" or the OTHERS choice).
1217 -- In this event we do not resolve Expr unless expansion is disabled.
1218 -- To know why, see the DELAYED COMPONENT RESOLUTION note above.
1219 --
1220 -- NOTE: In the case of "... => <>", we pass the in the
1221 -- N_Component_Association node as Expr, since there is no Expression in
1222 -- that case, and we need a Sloc for the error message.
1223
1224 ---------
1225 -- Add --
1226 ---------
1227
1228 function Add (Val : Uint; To : Node_Id) return Node_Id is
1229 Expr_Pos : Node_Id;
1230 Expr : Node_Id;
1231 To_Pos : Node_Id;
1232
1233 begin
1234 if Raises_Constraint_Error (To) then
1235 return To;
1236 end if;
1237
1238 -- First test if we can do constant folding
1239
1240 if Compile_Time_Known_Value (To)
1241 or else Nkind (To) = N_Integer_Literal
1242 then
1243 Expr_Pos := Make_Integer_Literal (Loc, Expr_Value (To) + Val);
1244 Set_Is_Static_Expression (Expr_Pos);
1245 Set_Etype (Expr_Pos, Etype (To));
1246 Set_Analyzed (Expr_Pos, Analyzed (To));
1247
1248 if not Is_Enumeration_Type (Index_Typ) then
1249 Expr := Expr_Pos;
1250
1251 -- If we are dealing with enumeration return
1252 -- Index_Typ'Val (Expr_Pos)
1253
1254 else
1255 Expr :=
1256 Make_Attribute_Reference
1257 (Loc,
1258 Prefix => New_Occurrence_Of (Index_Typ, Loc),
1259 Attribute_Name => Name_Val,
1260 Expressions => New_List (Expr_Pos));
1261 end if;
1262
1263 return Expr;
1264 end if;
1265
1266 -- If we are here no constant folding possible
1267
1268 if not Is_Enumeration_Type (Index_Base) then
1269 Expr :=
1270 Make_Op_Add (Loc,
1271 Left_Opnd => Duplicate_Subexpr (To),
1272 Right_Opnd => Make_Integer_Literal (Loc, Val));
1273
1274 -- If we are dealing with enumeration return
1275 -- Index_Typ'Val (Index_Typ'Pos (To) + Val)
1276
1277 else
1278 To_Pos :=
1279 Make_Attribute_Reference
1280 (Loc,
1281 Prefix => New_Occurrence_Of (Index_Typ, Loc),
1282 Attribute_Name => Name_Pos,
1283 Expressions => New_List (Duplicate_Subexpr (To)));
1284
1285 Expr_Pos :=
1286 Make_Op_Add (Loc,
1287 Left_Opnd => To_Pos,
1288 Right_Opnd => Make_Integer_Literal (Loc, Val));
1289
1290 Expr :=
1291 Make_Attribute_Reference
1292 (Loc,
1293 Prefix => New_Occurrence_Of (Index_Typ, Loc),
1294 Attribute_Name => Name_Val,
1295 Expressions => New_List (Expr_Pos));
1296
1297 -- If the index type has a non standard representation, the
1298 -- attributes 'Val and 'Pos expand into function calls and the
1299 -- resulting expression is considered non-safe for reevaluation
1300 -- by the backend. Relocate it into a constant temporary in order
1301 -- to make it safe for reevaluation.
1302
1303 if Has_Non_Standard_Rep (Etype (N)) then
1304 declare
1305 Def_Id : Entity_Id;
1306
1307 begin
1308 Def_Id := Make_Temporary (Loc, 'R', Expr);
1309 Set_Etype (Def_Id, Index_Typ);
1310 Insert_Action (N,
1311 Make_Object_Declaration (Loc,
1312 Defining_Identifier => Def_Id,
1313 Object_Definition =>
1314 New_Occurrence_Of (Index_Typ, Loc),
1315 Constant_Present => True,
1316 Expression => Relocate_Node (Expr)));
1317
1318 Expr := New_Occurrence_Of (Def_Id, Loc);
1319 end;
1320 end if;
1321 end if;
1322
1323 return Expr;
1324 end Add;
1325
1326 -----------------
1327 -- Check_Bound --
1328 -----------------
1329
1330 procedure Check_Bound (BH : Node_Id; AH : in out Node_Id) is
1331 Val_BH : Uint;
1332 Val_AH : Uint;
1333
1334 OK_BH : Boolean;
1335 OK_AH : Boolean;
1336
1337 begin
1338 Get (Value => Val_BH, From => BH, OK => OK_BH);
1339 Get (Value => Val_AH, From => AH, OK => OK_AH);
1340
1341 if OK_BH and then OK_AH and then Val_BH < Val_AH then
1342 Set_Raises_Constraint_Error (N);
1343 Error_Msg_Warn := SPARK_Mode /= On;
1344 Error_Msg_N ("upper bound out of range<<", AH);
1345 Error_Msg_N ("\Constraint_Error [<<", AH);
1346
1347 -- You need to set AH to BH or else in the case of enumerations
1348 -- indexes we will not be able to resolve the aggregate bounds.
1349
1350 AH := Duplicate_Subexpr (BH);
1351 end if;
1352 end Check_Bound;
1353
1354 ------------------
1355 -- Check_Bounds --
1356 ------------------
1357
1358 procedure Check_Bounds (L, H : Node_Id; AL, AH : Node_Id) is
1359 Val_L : Uint;
1360 Val_H : Uint;
1361 Val_AL : Uint;
1362 Val_AH : Uint;
1363
1364 OK_L : Boolean;
1365 OK_H : Boolean;
1366
1367 OK_AL : Boolean;
1368 OK_AH : Boolean;
1369 pragma Warnings (Off, OK_AL);
1370 pragma Warnings (Off, OK_AH);
1371
1372 begin
1373 if Raises_Constraint_Error (N)
1374 or else Dynamic_Or_Null_Range (AL, AH)
1375 then
1376 return;
1377 end if;
1378
1379 Get (Value => Val_L, From => L, OK => OK_L);
1380 Get (Value => Val_H, From => H, OK => OK_H);
1381
1382 Get (Value => Val_AL, From => AL, OK => OK_AL);
1383 Get (Value => Val_AH, From => AH, OK => OK_AH);
1384
1385 if OK_L and then Val_L > Val_AL then
1386 Set_Raises_Constraint_Error (N);
1387 Error_Msg_Warn := SPARK_Mode /= On;
1388 Error_Msg_N ("lower bound of aggregate out of range<<", N);
1389 Error_Msg_N ("\Constraint_Error [<<", N);
1390 end if;
1391
1392 if OK_H and then Val_H < Val_AH then
1393 Set_Raises_Constraint_Error (N);
1394 Error_Msg_Warn := SPARK_Mode /= On;
1395 Error_Msg_N ("upper bound of aggregate out of range<<", N);
1396 Error_Msg_N ("\Constraint_Error [<<", N);
1397 end if;
1398 end Check_Bounds;
1399
1400 ------------------
1401 -- Check_Length --
1402 ------------------
1403
1404 procedure Check_Length (L, H : Node_Id; Len : Uint) is
1405 Val_L : Uint;
1406 Val_H : Uint;
1407
1408 OK_L : Boolean;
1409 OK_H : Boolean;
1410
1411 Range_Len : Uint;
1412
1413 begin
1414 if Raises_Constraint_Error (N) then
1415 return;
1416 end if;
1417
1418 Get (Value => Val_L, From => L, OK => OK_L);
1419 Get (Value => Val_H, From => H, OK => OK_H);
1420
1421 if not OK_L or else not OK_H then
1422 return;
1423 end if;
1424
1425 -- If null range length is zero
1426
1427 if Val_L > Val_H then
1428 Range_Len := Uint_0;
1429 else
1430 Range_Len := Val_H - Val_L + 1;
1431 end if;
1432
1433 if Range_Len < Len then
1434 Set_Raises_Constraint_Error (N);
1435 Error_Msg_Warn := SPARK_Mode /= On;
1436 Error_Msg_N ("too many elements<<", N);
1437 Error_Msg_N ("\Constraint_Error [<<", N);
1438 end if;
1439 end Check_Length;
1440
1441 ---------------------------
1442 -- Dynamic_Or_Null_Range --
1443 ---------------------------
1444
1445 function Dynamic_Or_Null_Range (L, H : Node_Id) return Boolean is
1446 Val_L : Uint;
1447 Val_H : Uint;
1448
1449 OK_L : Boolean;
1450 OK_H : Boolean;
1451
1452 begin
1453 Get (Value => Val_L, From => L, OK => OK_L);
1454 Get (Value => Val_H, From => H, OK => OK_H);
1455
1456 return not OK_L or else not OK_H
1457 or else not Is_OK_Static_Expression (L)
1458 or else not Is_OK_Static_Expression (H)
1459 or else Val_L > Val_H;
1460 end Dynamic_Or_Null_Range;
1461
1462 ---------
1463 -- Get --
1464 ---------
1465
1466 procedure Get (Value : out Uint; From : Node_Id; OK : out Boolean) is
1467 begin
1468 OK := True;
1469
1470 if Compile_Time_Known_Value (From) then
1471 Value := Expr_Value (From);
1472
1473 -- If expression From is something like Some_Type'Val (10) then
1474 -- Value = 10.
1475
1476 elsif Nkind (From) = N_Attribute_Reference
1477 and then Attribute_Name (From) = Name_Val
1478 and then Compile_Time_Known_Value (First (Expressions (From)))
1479 then
1480 Value := Expr_Value (First (Expressions (From)));
1481 else
1482 Value := Uint_0;
1483 OK := False;
1484 end if;
1485 end Get;
1486
1487 -----------------------
1488 -- Resolve_Aggr_Expr --
1489 -----------------------
1490
1491 function Resolve_Aggr_Expr
1492 (Expr : Node_Id;
1493 Single_Elmt : Boolean) return Boolean
1494 is
1495 Nxt_Ind : constant Node_Id := Next_Index (Index);
1496 Nxt_Ind_Constr : constant Node_Id := Next_Index (Index_Constr);
1497 -- Index is the current index corresponding to the expression
1498
1499 Resolution_OK : Boolean := True;
1500 -- Set to False if resolution of the expression failed
1501
1502 begin
1503 -- Defend against previous errors
1504
1505 if Nkind (Expr) = N_Error
1506 or else Error_Posted (Expr)
1507 then
1508 return True;
1509 end if;
1510
1511 -- If the array type against which we are resolving the aggregate
1512 -- has several dimensions, the expressions nested inside the
1513 -- aggregate must be further aggregates (or strings).
1514
1515 if Present (Nxt_Ind) then
1516 if Nkind (Expr) /= N_Aggregate then
1517
1518 -- A string literal can appear where a one-dimensional array
1519 -- of characters is expected. If the literal looks like an
1520 -- operator, it is still an operator symbol, which will be
1521 -- transformed into a string when analyzed.
1522
1523 if Is_Character_Type (Component_Typ)
1524 and then No (Next_Index (Nxt_Ind))
1525 and then Nkind_In (Expr, N_String_Literal, N_Operator_Symbol)
1526 then
1527 -- A string literal used in a multidimensional array
1528 -- aggregate in place of the final one-dimensional
1529 -- aggregate must not be enclosed in parentheses.
1530
1531 if Paren_Count (Expr) /= 0 then
1532 Error_Msg_N ("no parenthesis allowed here", Expr);
1533 end if;
1534
1535 Make_String_Into_Aggregate (Expr);
1536
1537 else
1538 Error_Msg_N ("nested array aggregate expected", Expr);
1539
1540 -- If the expression is parenthesized, this may be
1541 -- a missing component association for a 1-aggregate.
1542
1543 if Paren_Count (Expr) > 0 then
1544 Error_Msg_N
1545 ("\if single-component aggregate is intended, "
1546 & "write e.g. (1 ='> ...)", Expr);
1547 end if;
1548
1549 return Failure;
1550 end if;
1551 end if;
1552
1553 -- If it's "... => <>", nothing to resolve
1554
1555 if Nkind (Expr) = N_Component_Association then
1556 pragma Assert (Box_Present (Expr));
1557 return Success;
1558 end if;
1559
1560 -- Ada 2005 (AI-231): Propagate the type to the nested aggregate.
1561 -- Required to check the null-exclusion attribute (if present).
1562 -- This value may be overridden later on.
1563
1564 Set_Etype (Expr, Etype (N));
1565
1566 Resolution_OK := Resolve_Array_Aggregate
1567 (Expr, Nxt_Ind, Nxt_Ind_Constr, Component_Typ, Others_Allowed);
1568
1569 else
1570 -- If it's "... => <>", nothing to resolve
1571
1572 if Nkind (Expr) = N_Component_Association then
1573 pragma Assert (Box_Present (Expr));
1574 return Success;
1575 end if;
1576
1577 -- Do not resolve the expressions of discrete or others choices
1578 -- unless the expression covers a single component, or the
1579 -- expander is inactive.
1580
1581 -- In SPARK mode, expressions that can perform side-effects will
1582 -- be recognized by the gnat2why back-end, and the whole
1583 -- subprogram will be ignored. So semantic analysis can be
1584 -- performed safely.
1585
1586 if Single_Elmt
1587 or else not Expander_Active
1588 or else In_Spec_Expression
1589 then
1590 Analyze_And_Resolve (Expr, Component_Typ);
1591 Check_Expr_OK_In_Limited_Aggregate (Expr);
1592 Check_Non_Static_Context (Expr);
1593 Aggregate_Constraint_Checks (Expr, Component_Typ);
1594 Check_Unset_Reference (Expr);
1595 end if;
1596 end if;
1597
1598 -- If an aggregate component has a type with predicates, an explicit
1599 -- predicate check must be applied, as for an assignment statement,
1600 -- because the aggegate might not be expanded into individual
1601 -- component assignments. If the expression covers several components
1602 -- the analysis and the predicate check take place later.
1603
1604 if Present (Predicate_Function (Component_Typ))
1605 and then Analyzed (Expr)
1606 then
1607 Apply_Predicate_Check (Expr, Component_Typ);
1608 end if;
1609
1610 if Raises_Constraint_Error (Expr)
1611 and then Nkind (Parent (Expr)) /= N_Component_Association
1612 then
1613 Set_Raises_Constraint_Error (N);
1614 end if;
1615
1616 -- If the expression has been marked as requiring a range check,
1617 -- then generate it here. It's a bit odd to be generating such
1618 -- checks in the analyzer, but harmless since Generate_Range_Check
1619 -- does nothing (other than making sure Do_Range_Check is set) if
1620 -- the expander is not active.
1621
1622 if Do_Range_Check (Expr) then
1623 Generate_Range_Check (Expr, Component_Typ, CE_Range_Check_Failed);
1624 end if;
1625
1626 return Resolution_OK;
1627 end Resolve_Aggr_Expr;
1628
1629 -- Variables local to Resolve_Array_Aggregate
1630
1631 Assoc : Node_Id;
1632 Choice : Node_Id;
1633 Expr : Node_Id;
1634 Discard : Node_Id;
1635
1636 Delete_Choice : Boolean;
1637 -- Used when replacing a subtype choice with predicate by a list
1638
1639 Aggr_Low : Node_Id := Empty;
1640 Aggr_High : Node_Id := Empty;
1641 -- The actual low and high bounds of this sub-aggregate
1642
1643 Choices_Low : Node_Id := Empty;
1644 Choices_High : Node_Id := Empty;
1645 -- The lowest and highest discrete choices values for a named aggregate
1646
1647 Nb_Elements : Uint := Uint_0;
1648 -- The number of elements in a positional aggregate
1649
1650 Others_Present : Boolean := False;
1651
1652 Nb_Choices : Nat := 0;
1653 -- Contains the overall number of named choices in this sub-aggregate
1654
1655 Nb_Discrete_Choices : Nat := 0;
1656 -- The overall number of discrete choices (not counting others choice)
1657
1658 Case_Table_Size : Nat;
1659 -- Contains the size of the case table needed to sort aggregate choices
1660
1661 -- Start of processing for Resolve_Array_Aggregate
1662
1663 begin
1664 -- Ignore junk empty aggregate resulting from parser error
1665
1666 if No (Expressions (N))
1667 and then No (Component_Associations (N))
1668 and then not Null_Record_Present (N)
1669 then
1670 return False;
1671 end if;
1672
1673 -- STEP 1: make sure the aggregate is correctly formatted
1674
1675 if Present (Component_Associations (N)) then
1676 Assoc := First (Component_Associations (N));
1677 while Present (Assoc) loop
1678 Choice := First (Choices (Assoc));
1679 Delete_Choice := False;
1680 while Present (Choice) loop
1681 if Nkind (Choice) = N_Others_Choice then
1682 Others_Present := True;
1683
1684 if Choice /= First (Choices (Assoc))
1685 or else Present (Next (Choice))
1686 then
1687 Error_Msg_N
1688 ("OTHERS must appear alone in a choice list", Choice);
1689 return Failure;
1690 end if;
1691
1692 if Present (Next (Assoc)) then
1693 Error_Msg_N
1694 ("OTHERS must appear last in an aggregate", Choice);
1695 return Failure;
1696 end if;
1697
1698 if Ada_Version = Ada_83
1699 and then Assoc /= First (Component_Associations (N))
1700 and then Nkind_In (Parent (N), N_Assignment_Statement,
1701 N_Object_Declaration)
1702 then
1703 Error_Msg_N
1704 ("(Ada 83) illegal context for OTHERS choice", N);
1705 end if;
1706
1707 elsif Is_Entity_Name (Choice) then
1708 Analyze (Choice);
1709
1710 declare
1711 E : constant Entity_Id := Entity (Choice);
1712 New_Cs : List_Id;
1713 P : Node_Id;
1714 C : Node_Id;
1715
1716 begin
1717 if Is_Type (E) and then Has_Predicates (E) then
1718 Freeze_Before (N, E);
1719
1720 if Has_Dynamic_Predicate_Aspect (E) then
1721 Error_Msg_NE
1722 ("subtype& has dynamic predicate, not allowed "
1723 & "in aggregate choice", Choice, E);
1724
1725 elsif not Is_OK_Static_Subtype (E) then
1726 Error_Msg_NE
1727 ("non-static subtype& has predicate, not allowed "
1728 & "in aggregate choice", Choice, E);
1729 end if;
1730
1731 -- If the subtype has a static predicate, replace the
1732 -- original choice with the list of individual values
1733 -- covered by the predicate.
1734
1735 if Present (Static_Discrete_Predicate (E)) then
1736 Delete_Choice := True;
1737
1738 New_Cs := New_List;
1739 P := First (Static_Discrete_Predicate (E));
1740 while Present (P) loop
1741 C := New_Copy (P);
1742 Set_Sloc (C, Sloc (Choice));
1743 Append_To (New_Cs, C);
1744 Next (P);
1745 end loop;
1746
1747 Insert_List_After (Choice, New_Cs);
1748 end if;
1749 end if;
1750 end;
1751 end if;
1752
1753 Nb_Choices := Nb_Choices + 1;
1754
1755 declare
1756 C : constant Node_Id := Choice;
1757
1758 begin
1759 Next (Choice);
1760
1761 if Delete_Choice then
1762 Remove (C);
1763 Nb_Choices := Nb_Choices - 1;
1764 Delete_Choice := False;
1765 end if;
1766 end;
1767 end loop;
1768
1769 Next (Assoc);
1770 end loop;
1771 end if;
1772
1773 -- At this point we know that the others choice, if present, is by
1774 -- itself and appears last in the aggregate. Check if we have mixed
1775 -- positional and discrete associations (other than the others choice).
1776
1777 if Present (Expressions (N))
1778 and then (Nb_Choices > 1
1779 or else (Nb_Choices = 1 and then not Others_Present))
1780 then
1781 Error_Msg_N
1782 ("named association cannot follow positional association",
1783 First (Choices (First (Component_Associations (N)))));
1784 return Failure;
1785 end if;
1786
1787 -- Test for the validity of an others choice if present
1788
1789 if Others_Present and then not Others_Allowed then
1790 Error_Msg_N
1791 ("OTHERS choice not allowed here",
1792 First (Choices (First (Component_Associations (N)))));
1793 return Failure;
1794 end if;
1795
1796 -- Protect against cascaded errors
1797
1798 if Etype (Index_Typ) = Any_Type then
1799 return Failure;
1800 end if;
1801
1802 -- STEP 2: Process named components
1803
1804 if No (Expressions (N)) then
1805 if Others_Present then
1806 Case_Table_Size := Nb_Choices - 1;
1807 else
1808 Case_Table_Size := Nb_Choices;
1809 end if;
1810
1811 Step_2 : declare
1812 function Empty_Range (A : Node_Id) return Boolean;
1813 -- If an association covers an empty range, some warnings on the
1814 -- expression of the association can be disabled.
1815
1816 -----------------
1817 -- Empty_Range --
1818 -----------------
1819
1820 function Empty_Range (A : Node_Id) return Boolean is
1821 R : constant Node_Id := First (Choices (A));
1822 begin
1823 return No (Next (R))
1824 and then Nkind (R) = N_Range
1825 and then Compile_Time_Compare
1826 (Low_Bound (R), High_Bound (R), False) = GT;
1827 end Empty_Range;
1828
1829 -- Local variables
1830
1831 Low : Node_Id;
1832 High : Node_Id;
1833 -- Denote the lowest and highest values in an aggregate choice
1834
1835 S_Low : Node_Id := Empty;
1836 S_High : Node_Id := Empty;
1837 -- if a choice in an aggregate is a subtype indication these
1838 -- denote the lowest and highest values of the subtype
1839
1840 Table : Case_Table_Type (0 .. Case_Table_Size);
1841 -- Used to sort all the different choice values. Entry zero is
1842 -- reserved for sorting purposes.
1843
1844 Single_Choice : Boolean;
1845 -- Set to true every time there is a single discrete choice in a
1846 -- discrete association
1847
1848 Prev_Nb_Discrete_Choices : Nat;
1849 -- Used to keep track of the number of discrete choices in the
1850 -- current association.
1851
1852 Errors_Posted_On_Choices : Boolean := False;
1853 -- Keeps track of whether any choices have semantic errors
1854
1855 -- Start of processing for Step_2
1856
1857 begin
1858 -- STEP 2 (A): Check discrete choices validity
1859
1860 Assoc := First (Component_Associations (N));
1861 while Present (Assoc) loop
1862 Prev_Nb_Discrete_Choices := Nb_Discrete_Choices;
1863 Choice := First (Choices (Assoc));
1864 loop
1865 Analyze (Choice);
1866
1867 if Nkind (Choice) = N_Others_Choice then
1868 Single_Choice := False;
1869 exit;
1870
1871 -- Test for subtype mark without constraint
1872
1873 elsif Is_Entity_Name (Choice) and then
1874 Is_Type (Entity (Choice))
1875 then
1876 if Base_Type (Entity (Choice)) /= Index_Base then
1877 Error_Msg_N
1878 ("invalid subtype mark in aggregate choice",
1879 Choice);
1880 return Failure;
1881 end if;
1882
1883 -- Case of subtype indication
1884
1885 elsif Nkind (Choice) = N_Subtype_Indication then
1886 Resolve_Discrete_Subtype_Indication (Choice, Index_Base);
1887
1888 if Has_Dynamic_Predicate_Aspect
1889 (Entity (Subtype_Mark (Choice)))
1890 then
1891 Error_Msg_NE
1892 ("subtype& has dynamic predicate, "
1893 & "not allowed in aggregate choice",
1894 Choice, Entity (Subtype_Mark (Choice)));
1895 end if;
1896
1897 -- Does the subtype indication evaluation raise CE?
1898
1899 Get_Index_Bounds (Subtype_Mark (Choice), S_Low, S_High);
1900 Get_Index_Bounds (Choice, Low, High);
1901 Check_Bounds (S_Low, S_High, Low, High);
1902
1903 -- Case of range or expression
1904
1905 else
1906 Resolve (Choice, Index_Base);
1907 Check_Unset_Reference (Choice);
1908 Check_Non_Static_Context (Choice);
1909
1910 -- If semantic errors were posted on the choice, then
1911 -- record that for possible early return from later
1912 -- processing (see handling of enumeration choices).
1913
1914 if Error_Posted (Choice) then
1915 Errors_Posted_On_Choices := True;
1916 end if;
1917
1918 -- Do not range check a choice. This check is redundant
1919 -- since this test is already done when we check that the
1920 -- bounds of the array aggregate are within range.
1921
1922 Set_Do_Range_Check (Choice, False);
1923
1924 -- In SPARK, the choice must be static
1925
1926 if not (Is_OK_Static_Expression (Choice)
1927 or else (Nkind (Choice) = N_Range
1928 and then Is_OK_Static_Range (Choice)))
1929 then
1930 Check_SPARK_05_Restriction
1931 ("choice should be static", Choice);
1932 end if;
1933 end if;
1934
1935 -- If we could not resolve the discrete choice stop here
1936
1937 if Etype (Choice) = Any_Type then
1938 return Failure;
1939
1940 -- If the discrete choice raises CE get its original bounds
1941
1942 elsif Nkind (Choice) = N_Raise_Constraint_Error then
1943 Set_Raises_Constraint_Error (N);
1944 Get_Index_Bounds (Original_Node (Choice), Low, High);
1945
1946 -- Otherwise get its bounds as usual
1947
1948 else
1949 Get_Index_Bounds (Choice, Low, High);
1950 end if;
1951
1952 if (Dynamic_Or_Null_Range (Low, High)
1953 or else (Nkind (Choice) = N_Subtype_Indication
1954 and then
1955 Dynamic_Or_Null_Range (S_Low, S_High)))
1956 and then Nb_Choices /= 1
1957 then
1958 Error_Msg_N
1959 ("dynamic or empty choice in aggregate "
1960 & "must be the only choice", Choice);
1961 return Failure;
1962 end if;
1963
1964 if not (All_Composite_Constraints_Static (Low)
1965 and then All_Composite_Constraints_Static (High)
1966 and then All_Composite_Constraints_Static (S_Low)
1967 and then All_Composite_Constraints_Static (S_High))
1968 then
1969 Check_Restriction (No_Dynamic_Sized_Objects, Choice);
1970 end if;
1971
1972 Nb_Discrete_Choices := Nb_Discrete_Choices + 1;
1973 Table (Nb_Discrete_Choices).Lo := Low;
1974 Table (Nb_Discrete_Choices).Hi := High;
1975 Table (Nb_Discrete_Choices).Choice := Choice;
1976
1977 Next (Choice);
1978
1979 if No (Choice) then
1980
1981 -- Check if we have a single discrete choice and whether
1982 -- this discrete choice specifies a single value.
1983
1984 Single_Choice :=
1985 (Nb_Discrete_Choices = Prev_Nb_Discrete_Choices + 1)
1986 and then (Low = High);
1987
1988 exit;
1989 end if;
1990 end loop;
1991
1992 -- Ada 2005 (AI-231)
1993
1994 if Ada_Version >= Ada_2005
1995 and then Known_Null (Expression (Assoc))
1996 and then not Empty_Range (Assoc)
1997 then
1998 Check_Can_Never_Be_Null (Etype (N), Expression (Assoc));
1999 end if;
2000
2001 -- Ada 2005 (AI-287): In case of default initialized component
2002 -- we delay the resolution to the expansion phase.
2003
2004 if Box_Present (Assoc) then
2005
2006 -- Ada 2005 (AI-287): In case of default initialization of a
2007 -- component the expander will generate calls to the
2008 -- corresponding initialization subprogram. We need to call
2009 -- Resolve_Aggr_Expr to check the rules about
2010 -- dimensionality.
2011
2012 if not Resolve_Aggr_Expr
2013 (Assoc, Single_Elmt => Single_Choice)
2014 then
2015 return Failure;
2016 end if;
2017
2018 elsif not Resolve_Aggr_Expr
2019 (Expression (Assoc), Single_Elmt => Single_Choice)
2020 then
2021 return Failure;
2022
2023 -- Check incorrect use of dynamically tagged expression
2024
2025 -- We differentiate here two cases because the expression may
2026 -- not be decorated. For example, the analysis and resolution
2027 -- of the expression associated with the others choice will be
2028 -- done later with the full aggregate. In such case we
2029 -- duplicate the expression tree to analyze the copy and
2030 -- perform the required check.
2031
2032 elsif not Present (Etype (Expression (Assoc))) then
2033 declare
2034 Save_Analysis : constant Boolean := Full_Analysis;
2035 Expr : constant Node_Id :=
2036 New_Copy_Tree (Expression (Assoc));
2037
2038 begin
2039 Expander_Mode_Save_And_Set (False);
2040 Full_Analysis := False;
2041
2042 -- Analyze the expression, making sure it is properly
2043 -- attached to the tree before we do the analysis.
2044
2045 Set_Parent (Expr, Parent (Expression (Assoc)));
2046 Analyze (Expr);
2047
2048 -- Compute its dimensions now, rather than at the end of
2049 -- resolution, because in the case of multidimensional
2050 -- aggregates subsequent expansion may lead to spurious
2051 -- errors.
2052
2053 Check_Expression_Dimensions (Expr, Component_Typ);
2054
2055 -- If the expression is a literal, propagate this info
2056 -- to the expression in the association, to enable some
2057 -- optimizations downstream.
2058
2059 if Is_Entity_Name (Expr)
2060 and then Present (Entity (Expr))
2061 and then Ekind (Entity (Expr)) = E_Enumeration_Literal
2062 then
2063 Analyze_And_Resolve
2064 (Expression (Assoc), Component_Typ);
2065 end if;
2066
2067 Full_Analysis := Save_Analysis;
2068 Expander_Mode_Restore;
2069
2070 if Is_Tagged_Type (Etype (Expr)) then
2071 Check_Dynamically_Tagged_Expression
2072 (Expr => Expr,
2073 Typ => Component_Type (Etype (N)),
2074 Related_Nod => N);
2075 end if;
2076 end;
2077
2078 elsif Is_Tagged_Type (Etype (Expression (Assoc))) then
2079 Check_Dynamically_Tagged_Expression
2080 (Expr => Expression (Assoc),
2081 Typ => Component_Type (Etype (N)),
2082 Related_Nod => N);
2083 end if;
2084
2085 Next (Assoc);
2086 end loop;
2087
2088 -- If aggregate contains more than one choice then these must be
2089 -- static. Check for duplicate and missing values.
2090
2091 -- Note: there is duplicated code here wrt Check_Choice_Set in
2092 -- the body of Sem_Case, and it is possible we could just reuse
2093 -- that procedure. To be checked ???
2094
2095 if Nb_Discrete_Choices > 1 then
2096 Check_Choices : declare
2097 Choice : Node_Id;
2098 -- Location of choice for messages
2099
2100 Hi_Val : Uint;
2101 Lo_Val : Uint;
2102 -- High end of one range and Low end of the next. Should be
2103 -- contiguous if there is no hole in the list of values.
2104
2105 Lo_Dup : Uint;
2106 Hi_Dup : Uint;
2107 -- End points of duplicated range
2108
2109 Missing_Or_Duplicates : Boolean := False;
2110 -- Set True if missing or duplicate choices found
2111
2112 procedure Output_Bad_Choices (Lo, Hi : Uint; C : Node_Id);
2113 -- Output continuation message with a representation of the
2114 -- bounds (just Lo if Lo = Hi, else Lo .. Hi). C is the
2115 -- choice node where the message is to be posted.
2116
2117 ------------------------
2118 -- Output_Bad_Choices --
2119 ------------------------
2120
2121 procedure Output_Bad_Choices (Lo, Hi : Uint; C : Node_Id) is
2122 begin
2123 -- Enumeration type case
2124
2125 if Is_Enumeration_Type (Index_Typ) then
2126 Error_Msg_Name_1 :=
2127 Chars (Get_Enum_Lit_From_Pos (Index_Typ, Lo, Loc));
2128 Error_Msg_Name_2 :=
2129 Chars (Get_Enum_Lit_From_Pos (Index_Typ, Hi, Loc));
2130
2131 if Lo = Hi then
2132 Error_Msg_N ("\\ %!", C);
2133 else
2134 Error_Msg_N ("\\ % .. %!", C);
2135 end if;
2136
2137 -- Integer types case
2138
2139 else
2140 Error_Msg_Uint_1 := Lo;
2141 Error_Msg_Uint_2 := Hi;
2142
2143 if Lo = Hi then
2144 Error_Msg_N ("\\ ^!", C);
2145 else
2146 Error_Msg_N ("\\ ^ .. ^!", C);
2147 end if;
2148 end if;
2149 end Output_Bad_Choices;
2150
2151 -- Start of processing for Check_Choices
2152
2153 begin
2154 Sort_Case_Table (Table);
2155
2156 -- First we do a quick linear loop to find out if we have
2157 -- any duplicates or missing entries (usually we have a
2158 -- legal aggregate, so this will get us out quickly).
2159
2160 for J in 1 .. Nb_Discrete_Choices - 1 loop
2161 Hi_Val := Expr_Value (Table (J).Hi);
2162 Lo_Val := Expr_Value (Table (J + 1).Lo);
2163
2164 if Lo_Val <= Hi_Val
2165 or else (Lo_Val > Hi_Val + 1
2166 and then not Others_Present)
2167 then
2168 Missing_Or_Duplicates := True;
2169 exit;
2170 end if;
2171 end loop;
2172
2173 -- If we have missing or duplicate entries, first fill in
2174 -- the Highest entries to make life easier in the following
2175 -- loops to detect bad entries.
2176
2177 if Missing_Or_Duplicates then
2178 Table (1).Highest := Expr_Value (Table (1).Hi);
2179
2180 for J in 2 .. Nb_Discrete_Choices loop
2181 Table (J).Highest :=
2182 UI_Max
2183 (Table (J - 1).Highest, Expr_Value (Table (J).Hi));
2184 end loop;
2185
2186 -- Loop through table entries to find duplicate indexes
2187
2188 for J in 2 .. Nb_Discrete_Choices loop
2189 Lo_Val := Expr_Value (Table (J).Lo);
2190 Hi_Val := Expr_Value (Table (J).Hi);
2191
2192 -- Case where we have duplicates (the lower bound of
2193 -- this choice is less than or equal to the highest
2194 -- high bound found so far).
2195
2196 if Lo_Val <= Table (J - 1).Highest then
2197
2198 -- We move backwards looking for duplicates. We can
2199 -- abandon this loop as soon as we reach a choice
2200 -- highest value that is less than Lo_Val.
2201
2202 for K in reverse 1 .. J - 1 loop
2203 exit when Table (K).Highest < Lo_Val;
2204
2205 -- Here we may have duplicates between entries
2206 -- for K and J. Get range of duplicates.
2207
2208 Lo_Dup :=
2209 UI_Max (Lo_Val, Expr_Value (Table (K).Lo));
2210 Hi_Dup :=
2211 UI_Min (Hi_Val, Expr_Value (Table (K).Hi));
2212
2213 -- Nothing to do if duplicate range is null
2214
2215 if Lo_Dup > Hi_Dup then
2216 null;
2217
2218 -- Otherwise place proper message
2219
2220 else
2221 -- We place message on later choice, with a
2222 -- line reference to the earlier choice.
2223
2224 if Sloc (Table (J).Choice) <
2225 Sloc (Table (K).Choice)
2226 then
2227 Choice := Table (K).Choice;
2228 Error_Msg_Sloc := Sloc (Table (J).Choice);
2229 else
2230 Choice := Table (J).Choice;
2231 Error_Msg_Sloc := Sloc (Table (K).Choice);
2232 end if;
2233
2234 if Lo_Dup = Hi_Dup then
2235 Error_Msg_N
2236 ("index value in array aggregate "
2237 & "duplicates the one given#!", Choice);
2238 else
2239 Error_Msg_N
2240 ("index values in array aggregate "
2241 & "duplicate those given#!", Choice);
2242 end if;
2243
2244 Output_Bad_Choices (Lo_Dup, Hi_Dup, Choice);
2245 end if;
2246 end loop;
2247 end if;
2248 end loop;
2249
2250 -- Loop through entries in table to find missing indexes.
2251 -- Not needed if others, since missing impossible.
2252
2253 if not Others_Present then
2254 for J in 2 .. Nb_Discrete_Choices loop
2255 Lo_Val := Expr_Value (Table (J).Lo);
2256 Hi_Val := Table (J - 1).Highest;
2257
2258 if Lo_Val > Hi_Val + 1 then
2259
2260 declare
2261 Error_Node : Node_Id;
2262
2263 begin
2264 -- If the choice is the bound of a range in
2265 -- a subtype indication, it is not in the
2266 -- source lists for the aggregate itself, so
2267 -- post the error on the aggregate. Otherwise
2268 -- post it on choice itself.
2269
2270 Choice := Table (J).Choice;
2271
2272 if Is_List_Member (Choice) then
2273 Error_Node := Choice;
2274 else
2275 Error_Node := N;
2276 end if;
2277
2278 if Hi_Val + 1 = Lo_Val - 1 then
2279 Error_Msg_N
2280 ("missing index value "
2281 & "in array aggregate!", Error_Node);
2282 else
2283 Error_Msg_N
2284 ("missing index values "
2285 & "in array aggregate!", Error_Node);
2286 end if;
2287
2288 Output_Bad_Choices
2289 (Hi_Val + 1, Lo_Val - 1, Error_Node);
2290 end;
2291 end if;
2292 end loop;
2293 end if;
2294
2295 -- If either missing or duplicate values, return failure
2296
2297 Set_Etype (N, Any_Composite);
2298 return Failure;
2299 end if;
2300 end Check_Choices;
2301 end if;
2302
2303 -- STEP 2 (B): Compute aggregate bounds and min/max choices values
2304
2305 if Nb_Discrete_Choices > 0 then
2306 Choices_Low := Table (1).Lo;
2307 Choices_High := Table (Nb_Discrete_Choices).Hi;
2308 end if;
2309
2310 -- If Others is present, then bounds of aggregate come from the
2311 -- index constraint (not the choices in the aggregate itself).
2312
2313 if Others_Present then
2314 Get_Index_Bounds (Index_Constr, Aggr_Low, Aggr_High);
2315
2316 -- Abandon processing if either bound is already signalled as
2317 -- an error (prevents junk cascaded messages and blow ups).
2318
2319 if Nkind (Aggr_Low) = N_Error
2320 or else
2321 Nkind (Aggr_High) = N_Error
2322 then
2323 return False;
2324 end if;
2325
2326 -- No others clause present
2327
2328 else
2329 -- Special processing if others allowed and not present. This
2330 -- means that the bounds of the aggregate come from the index
2331 -- constraint (and the length must match).
2332
2333 if Others_Allowed then
2334 Get_Index_Bounds (Index_Constr, Aggr_Low, Aggr_High);
2335
2336 -- Abandon processing if either bound is already signalled
2337 -- as an error (stop junk cascaded messages and blow ups).
2338
2339 if Nkind (Aggr_Low) = N_Error
2340 or else
2341 Nkind (Aggr_High) = N_Error
2342 then
2343 return False;
2344 end if;
2345
2346 -- If others allowed, and no others present, then the array
2347 -- should cover all index values. If it does not, we will
2348 -- get a length check warning, but there is two cases where
2349 -- an additional warning is useful:
2350
2351 -- If we have no positional components, and the length is
2352 -- wrong (which we can tell by others being allowed with
2353 -- missing components), and the index type is an enumeration
2354 -- type, then issue appropriate warnings about these missing
2355 -- components. They are only warnings, since the aggregate
2356 -- is fine, it's just the wrong length. We skip this check
2357 -- for standard character types (since there are no literals
2358 -- and it is too much trouble to concoct them), and also if
2359 -- any of the bounds have values that are not known at
2360 -- compile time.
2361
2362 -- Another case warranting a warning is when the length
2363 -- is right, but as above we have an index type that is
2364 -- an enumeration, and the bounds do not match. This is a
2365 -- case where dubious sliding is allowed and we generate a
2366 -- warning that the bounds do not match.
2367
2368 if No (Expressions (N))
2369 and then Nkind (Index) = N_Range
2370 and then Is_Enumeration_Type (Etype (Index))
2371 and then not Is_Standard_Character_Type (Etype (Index))
2372 and then Compile_Time_Known_Value (Aggr_Low)
2373 and then Compile_Time_Known_Value (Aggr_High)
2374 and then Compile_Time_Known_Value (Choices_Low)
2375 and then Compile_Time_Known_Value (Choices_High)
2376 then
2377 -- If any of the expressions or range bounds in choices
2378 -- have semantic errors, then do not attempt further
2379 -- resolution, to prevent cascaded errors.
2380
2381 if Errors_Posted_On_Choices then
2382 return Failure;
2383 end if;
2384
2385 declare
2386 ALo : constant Node_Id := Expr_Value_E (Aggr_Low);
2387 AHi : constant Node_Id := Expr_Value_E (Aggr_High);
2388 CLo : constant Node_Id := Expr_Value_E (Choices_Low);
2389 CHi : constant Node_Id := Expr_Value_E (Choices_High);
2390
2391 Ent : Entity_Id;
2392
2393 begin
2394 -- Warning case 1, missing values at start/end. Only
2395 -- do the check if the number of entries is too small.
2396
2397 if (Enumeration_Pos (CHi) - Enumeration_Pos (CLo))
2398 <
2399 (Enumeration_Pos (AHi) - Enumeration_Pos (ALo))
2400 then
2401 Error_Msg_N
2402 ("missing index value(s) in array aggregate??",
2403 N);
2404
2405 -- Output missing value(s) at start
2406
2407 if Chars (ALo) /= Chars (CLo) then
2408 Ent := Prev (CLo);
2409
2410 if Chars (ALo) = Chars (Ent) then
2411 Error_Msg_Name_1 := Chars (ALo);
2412 Error_Msg_N ("\ %??", N);
2413 else
2414 Error_Msg_Name_1 := Chars (ALo);
2415 Error_Msg_Name_2 := Chars (Ent);
2416 Error_Msg_N ("\ % .. %??", N);
2417 end if;
2418 end if;
2419
2420 -- Output missing value(s) at end
2421
2422 if Chars (AHi) /= Chars (CHi) then
2423 Ent := Next (CHi);
2424
2425 if Chars (AHi) = Chars (Ent) then
2426 Error_Msg_Name_1 := Chars (Ent);
2427 Error_Msg_N ("\ %??", N);
2428 else
2429 Error_Msg_Name_1 := Chars (Ent);
2430 Error_Msg_Name_2 := Chars (AHi);
2431 Error_Msg_N ("\ % .. %??", N);
2432 end if;
2433 end if;
2434
2435 -- Warning case 2, dubious sliding. The First_Subtype
2436 -- test distinguishes between a constrained type where
2437 -- sliding is not allowed (so we will get a warning
2438 -- later that Constraint_Error will be raised), and
2439 -- the unconstrained case where sliding is permitted.
2440
2441 elsif (Enumeration_Pos (CHi) - Enumeration_Pos (CLo))
2442 =
2443 (Enumeration_Pos (AHi) - Enumeration_Pos (ALo))
2444 and then Chars (ALo) /= Chars (CLo)
2445 and then
2446 not Is_Constrained (First_Subtype (Etype (N)))
2447 then
2448 Error_Msg_N
2449 ("bounds of aggregate do not match target??", N);
2450 end if;
2451 end;
2452 end if;
2453 end if;
2454
2455 -- If no others, aggregate bounds come from aggregate
2456
2457 Aggr_Low := Choices_Low;
2458 Aggr_High := Choices_High;
2459 end if;
2460 end Step_2;
2461
2462 -- STEP 3: Process positional components
2463
2464 else
2465 -- STEP 3 (A): Process positional elements
2466
2467 Expr := First (Expressions (N));
2468 Nb_Elements := Uint_0;
2469 while Present (Expr) loop
2470 Nb_Elements := Nb_Elements + 1;
2471
2472 -- Ada 2005 (AI-231)
2473
2474 if Ada_Version >= Ada_2005 and then Known_Null (Expr) then
2475 Check_Can_Never_Be_Null (Etype (N), Expr);
2476 end if;
2477
2478 if not Resolve_Aggr_Expr (Expr, Single_Elmt => True) then
2479 return Failure;
2480 end if;
2481
2482 -- Check incorrect use of dynamically tagged expression
2483
2484 if Is_Tagged_Type (Etype (Expr)) then
2485 Check_Dynamically_Tagged_Expression
2486 (Expr => Expr,
2487 Typ => Component_Type (Etype (N)),
2488 Related_Nod => N);
2489 end if;
2490
2491 Next (Expr);
2492 end loop;
2493
2494 if Others_Present then
2495 Assoc := Last (Component_Associations (N));
2496
2497 -- Ada 2005 (AI-231)
2498
2499 if Ada_Version >= Ada_2005 and then Known_Null (Assoc) then
2500 Check_Can_Never_Be_Null (Etype (N), Expression (Assoc));
2501 end if;
2502
2503 -- Ada 2005 (AI-287): In case of default initialized component,
2504 -- we delay the resolution to the expansion phase.
2505
2506 if Box_Present (Assoc) then
2507
2508 -- Ada 2005 (AI-287): In case of default initialization of a
2509 -- component the expander will generate calls to the
2510 -- corresponding initialization subprogram. We need to call
2511 -- Resolve_Aggr_Expr to check the rules about
2512 -- dimensionality.
2513
2514 if not Resolve_Aggr_Expr (Assoc, Single_Elmt => False) then
2515 return Failure;
2516 end if;
2517
2518 elsif not Resolve_Aggr_Expr (Expression (Assoc),
2519 Single_Elmt => False)
2520 then
2521 return Failure;
2522
2523 -- Check incorrect use of dynamically tagged expression. The
2524 -- expression of the others choice has not been resolved yet.
2525 -- In order to diagnose the semantic error we create a duplicate
2526 -- tree to analyze it and perform the check.
2527
2528 else
2529 declare
2530 Save_Analysis : constant Boolean := Full_Analysis;
2531 Expr : constant Node_Id :=
2532 New_Copy_Tree (Expression (Assoc));
2533
2534 begin
2535 Expander_Mode_Save_And_Set (False);
2536 Full_Analysis := False;
2537 Analyze (Expr);
2538 Full_Analysis := Save_Analysis;
2539 Expander_Mode_Restore;
2540
2541 if Is_Tagged_Type (Etype (Expr)) then
2542 Check_Dynamically_Tagged_Expression
2543 (Expr => Expr,
2544 Typ => Component_Type (Etype (N)),
2545 Related_Nod => N);
2546 end if;
2547 end;
2548 end if;
2549 end if;
2550
2551 -- STEP 3 (B): Compute the aggregate bounds
2552
2553 if Others_Present then
2554 Get_Index_Bounds (Index_Constr, Aggr_Low, Aggr_High);
2555
2556 else
2557 if Others_Allowed then
2558 Get_Index_Bounds (Index_Constr, Aggr_Low, Discard);
2559 else
2560 Aggr_Low := Index_Typ_Low;
2561 end if;
2562
2563 Aggr_High := Add (Nb_Elements - 1, To => Aggr_Low);
2564 Check_Bound (Index_Base_High, Aggr_High);
2565 end if;
2566 end if;
2567
2568 -- STEP 4: Perform static aggregate checks and save the bounds
2569
2570 -- Check (A)
2571
2572 Check_Bounds (Index_Typ_Low, Index_Typ_High, Aggr_Low, Aggr_High);
2573 Check_Bounds (Index_Base_Low, Index_Base_High, Aggr_Low, Aggr_High);
2574
2575 -- Check (B)
2576
2577 if Others_Present and then Nb_Discrete_Choices > 0 then
2578 Check_Bounds (Aggr_Low, Aggr_High, Choices_Low, Choices_High);
2579 Check_Bounds (Index_Typ_Low, Index_Typ_High,
2580 Choices_Low, Choices_High);
2581 Check_Bounds (Index_Base_Low, Index_Base_High,
2582 Choices_Low, Choices_High);
2583
2584 -- Check (C)
2585
2586 elsif Others_Present and then Nb_Elements > 0 then
2587 Check_Length (Aggr_Low, Aggr_High, Nb_Elements);
2588 Check_Length (Index_Typ_Low, Index_Typ_High, Nb_Elements);
2589 Check_Length (Index_Base_Low, Index_Base_High, Nb_Elements);
2590 end if;
2591
2592 if Raises_Constraint_Error (Aggr_Low)
2593 or else Raises_Constraint_Error (Aggr_High)
2594 then
2595 Set_Raises_Constraint_Error (N);
2596 end if;
2597
2598 Aggr_Low := Duplicate_Subexpr (Aggr_Low);
2599
2600 -- Do not duplicate Aggr_High if Aggr_High = Aggr_Low + Nb_Elements
2601 -- since the addition node returned by Add is not yet analyzed. Attach
2602 -- to tree and analyze first. Reset analyzed flag to ensure it will get
2603 -- analyzed when it is a literal bound whose type must be properly set.
2604
2605 if Others_Present or else Nb_Discrete_Choices > 0 then
2606 Aggr_High := Duplicate_Subexpr (Aggr_High);
2607
2608 if Etype (Aggr_High) = Universal_Integer then
2609 Set_Analyzed (Aggr_High, False);
2610 end if;
2611 end if;
2612
2613 -- If the aggregate already has bounds attached to it, it means this is
2614 -- a positional aggregate created as an optimization by
2615 -- Exp_Aggr.Convert_To_Positional, so we don't want to change those
2616 -- bounds.
2617
2618 if Present (Aggregate_Bounds (N)) and then not Others_Allowed then
2619 Aggr_Low := Low_Bound (Aggregate_Bounds (N));
2620 Aggr_High := High_Bound (Aggregate_Bounds (N));
2621 end if;
2622
2623 Set_Aggregate_Bounds
2624 (N, Make_Range (Loc, Low_Bound => Aggr_Low, High_Bound => Aggr_High));
2625
2626 -- The bounds may contain expressions that must be inserted upwards.
2627 -- Attach them fully to the tree. After analysis, remove side effects
2628 -- from upper bound, if still needed.
2629
2630 Set_Parent (Aggregate_Bounds (N), N);
2631 Analyze_And_Resolve (Aggregate_Bounds (N), Index_Typ);
2632 Check_Unset_Reference (Aggregate_Bounds (N));
2633
2634 if not Others_Present and then Nb_Discrete_Choices = 0 then
2635 Set_High_Bound
2636 (Aggregate_Bounds (N),
2637 Duplicate_Subexpr (High_Bound (Aggregate_Bounds (N))));
2638 end if;
2639
2640 -- Check the dimensions of each component in the array aggregate
2641
2642 Analyze_Dimension_Array_Aggregate (N, Component_Typ);
2643
2644 return Success;
2645 end Resolve_Array_Aggregate;
2646
2647 ---------------------------------
2648 -- Resolve_Extension_Aggregate --
2649 ---------------------------------
2650
2651 -- There are two cases to consider:
2652
2653 -- a) If the ancestor part is a type mark, the components needed are the
2654 -- difference between the components of the expected type and the
2655 -- components of the given type mark.
2656
2657 -- b) If the ancestor part is an expression, it must be unambiguous, and
2658 -- once we have its type we can also compute the needed components as in
2659 -- the previous case. In both cases, if the ancestor type is not the
2660 -- immediate ancestor, we have to build this ancestor recursively.
2661
2662 -- In both cases, discriminants of the ancestor type do not play a role in
2663 -- the resolution of the needed components, because inherited discriminants
2664 -- cannot be used in a type extension. As a result we can compute
2665 -- independently the list of components of the ancestor type and of the
2666 -- expected type.
2667
2668 procedure Resolve_Extension_Aggregate (N : Node_Id; Typ : Entity_Id) is
2669 A : constant Node_Id := Ancestor_Part (N);
2670 A_Type : Entity_Id;
2671 I : Interp_Index;
2672 It : Interp;
2673
2674 function Valid_Limited_Ancestor (Anc : Node_Id) return Boolean;
2675 -- If the type is limited, verify that the ancestor part is a legal
2676 -- expression (aggregate or function call, including 'Input)) that does
2677 -- not require a copy, as specified in 7.5(2).
2678
2679 function Valid_Ancestor_Type return Boolean;
2680 -- Verify that the type of the ancestor part is a non-private ancestor
2681 -- of the expected type, which must be a type extension.
2682
2683 ----------------------------
2684 -- Valid_Limited_Ancestor --
2685 ----------------------------
2686
2687 function Valid_Limited_Ancestor (Anc : Node_Id) return Boolean is
2688 begin
2689 if Is_Entity_Name (Anc) and then Is_Type (Entity (Anc)) then
2690 return True;
2691
2692 -- The ancestor must be a call or an aggregate, but a call may
2693 -- have been expanded into a temporary, so check original node.
2694
2695 elsif Nkind_In (Anc, N_Aggregate,
2696 N_Extension_Aggregate,
2697 N_Function_Call)
2698 then
2699 return True;
2700
2701 elsif Nkind (Original_Node (Anc)) = N_Function_Call then
2702 return True;
2703
2704 elsif Nkind (Anc) = N_Attribute_Reference
2705 and then Attribute_Name (Anc) = Name_Input
2706 then
2707 return True;
2708
2709 elsif Nkind (Anc) = N_Qualified_Expression then
2710 return Valid_Limited_Ancestor (Expression (Anc));
2711
2712 else
2713 return False;
2714 end if;
2715 end Valid_Limited_Ancestor;
2716
2717 -------------------------
2718 -- Valid_Ancestor_Type --
2719 -------------------------
2720
2721 function Valid_Ancestor_Type return Boolean is
2722 Imm_Type : Entity_Id;
2723
2724 begin
2725 Imm_Type := Base_Type (Typ);
2726 while Is_Derived_Type (Imm_Type) loop
2727 if Etype (Imm_Type) = Base_Type (A_Type) then
2728 return True;
2729
2730 -- The base type of the parent type may appear as a private
2731 -- extension if it is declared as such in a parent unit of the
2732 -- current one. For consistency of the subsequent analysis use
2733 -- the partial view for the ancestor part.
2734
2735 elsif Is_Private_Type (Etype (Imm_Type))
2736 and then Present (Full_View (Etype (Imm_Type)))
2737 and then Base_Type (A_Type) = Full_View (Etype (Imm_Type))
2738 then
2739 A_Type := Etype (Imm_Type);
2740 return True;
2741
2742 -- The parent type may be a private extension. The aggregate is
2743 -- legal if the type of the aggregate is an extension of it that
2744 -- is not a private extension.
2745
2746 elsif Is_Private_Type (A_Type)
2747 and then not Is_Private_Type (Imm_Type)
2748 and then Present (Full_View (A_Type))
2749 and then Base_Type (Full_View (A_Type)) = Etype (Imm_Type)
2750 then
2751 return True;
2752
2753 else
2754 Imm_Type := Etype (Base_Type (Imm_Type));
2755 end if;
2756 end loop;
2757
2758 -- If previous loop did not find a proper ancestor, report error
2759
2760 Error_Msg_NE ("expect ancestor type of &", A, Typ);
2761 return False;
2762 end Valid_Ancestor_Type;
2763
2764 -- Start of processing for Resolve_Extension_Aggregate
2765
2766 begin
2767 -- Analyze the ancestor part and account for the case where it is a
2768 -- parameterless function call.
2769
2770 Analyze (A);
2771 Check_Parameterless_Call (A);
2772
2773 -- In SPARK, the ancestor part cannot be a type mark
2774
2775 if Is_Entity_Name (A) and then Is_Type (Entity (A)) then
2776 Check_SPARK_05_Restriction ("ancestor part cannot be a type mark", A);
2777
2778 -- AI05-0115: if the ancestor part is a subtype mark, the ancestor
2779 -- must not have unknown discriminants.
2780
2781 if Has_Unknown_Discriminants (Root_Type (Typ)) then
2782 Error_Msg_NE
2783 ("aggregate not available for type& whose ancestor "
2784 & "has unknown discriminants", N, Typ);
2785 end if;
2786 end if;
2787
2788 if not Is_Tagged_Type (Typ) then
2789 Error_Msg_N ("type of extension aggregate must be tagged", N);
2790 return;
2791
2792 elsif Is_Limited_Type (Typ) then
2793
2794 -- Ada 2005 (AI-287): Limited aggregates are allowed
2795
2796 if Ada_Version < Ada_2005 then
2797 Error_Msg_N ("aggregate type cannot be limited", N);
2798 Explain_Limited_Type (Typ, N);
2799 return;
2800
2801 elsif Valid_Limited_Ancestor (A) then
2802 null;
2803
2804 else
2805 Error_Msg_N
2806 ("limited ancestor part must be aggregate or function call", A);
2807 end if;
2808
2809 elsif Is_Class_Wide_Type (Typ) then
2810 Error_Msg_N ("aggregate cannot be of a class-wide type", N);
2811 return;
2812 end if;
2813
2814 if Is_Entity_Name (A) and then Is_Type (Entity (A)) then
2815 A_Type := Get_Full_View (Entity (A));
2816
2817 if Valid_Ancestor_Type then
2818 Set_Entity (A, A_Type);
2819 Set_Etype (A, A_Type);
2820
2821 Validate_Ancestor_Part (N);
2822 Resolve_Record_Aggregate (N, Typ);
2823 end if;
2824
2825 elsif Nkind (A) /= N_Aggregate then
2826 if Is_Overloaded (A) then
2827 A_Type := Any_Type;
2828
2829 Get_First_Interp (A, I, It);
2830 while Present (It.Typ) loop
2831
2832 -- Only consider limited interpretations in the Ada 2005 case
2833
2834 if Is_Tagged_Type (It.Typ)
2835 and then (Ada_Version >= Ada_2005
2836 or else not Is_Limited_Type (It.Typ))
2837 then
2838 if A_Type /= Any_Type then
2839 Error_Msg_N ("cannot resolve expression", A);
2840 return;
2841 else
2842 A_Type := It.Typ;
2843 end if;
2844 end if;
2845
2846 Get_Next_Interp (I, It);
2847 end loop;
2848
2849 if A_Type = Any_Type then
2850 if Ada_Version >= Ada_2005 then
2851 Error_Msg_N
2852 ("ancestor part must be of a tagged type", A);
2853 else
2854 Error_Msg_N
2855 ("ancestor part must be of a nonlimited tagged type", A);
2856 end if;
2857
2858 return;
2859 end if;
2860
2861 else
2862 A_Type := Etype (A);
2863 end if;
2864
2865 if Valid_Ancestor_Type then
2866 Resolve (A, A_Type);
2867 Check_Unset_Reference (A);
2868 Check_Non_Static_Context (A);
2869
2870 -- The aggregate is illegal if the ancestor expression is a call
2871 -- to a function with a limited unconstrained result, unless the
2872 -- type of the aggregate is a null extension. This restriction
2873 -- was added in AI05-67 to simplify implementation.
2874
2875 if Nkind (A) = N_Function_Call
2876 and then Is_Limited_Type (A_Type)
2877 and then not Is_Null_Extension (Typ)
2878 and then not Is_Constrained (A_Type)
2879 then
2880 Error_Msg_N
2881 ("type of limited ancestor part must be constrained", A);
2882
2883 -- Reject the use of CPP constructors that leave objects partially
2884 -- initialized. For example:
2885
2886 -- type CPP_Root is tagged limited record ...
2887 -- pragma Import (CPP, CPP_Root);
2888
2889 -- type CPP_DT is new CPP_Root and Iface ...
2890 -- pragma Import (CPP, CPP_DT);
2891
2892 -- type Ada_DT is new CPP_DT with ...
2893
2894 -- Obj : Ada_DT := Ada_DT'(New_CPP_Root with others => <>);
2895
2896 -- Using the constructor of CPP_Root the slots of the dispatch
2897 -- table of CPP_DT cannot be set, and the secondary tag of
2898 -- CPP_DT is unknown.
2899
2900 elsif Nkind (A) = N_Function_Call
2901 and then Is_CPP_Constructor_Call (A)
2902 and then Enclosing_CPP_Parent (Typ) /= A_Type
2903 then
2904 Error_Msg_NE
2905 ("??must use 'C'P'P constructor for type &", A,
2906 Enclosing_CPP_Parent (Typ));
2907
2908 -- The following call is not needed if the previous warning
2909 -- is promoted to an error.
2910
2911 Resolve_Record_Aggregate (N, Typ);
2912
2913 elsif Is_Class_Wide_Type (Etype (A))
2914 and then Nkind (Original_Node (A)) = N_Function_Call
2915 then
2916 -- If the ancestor part is a dispatching call, it appears
2917 -- statically to be a legal ancestor, but it yields any member
2918 -- of the class, and it is not possible to determine whether
2919 -- it is an ancestor of the extension aggregate (much less
2920 -- which ancestor). It is not possible to determine the
2921 -- components of the extension part.
2922
2923 -- This check implements AI-306, which in fact was motivated by
2924 -- an AdaCore query to the ARG after this test was added.
2925
2926 Error_Msg_N ("ancestor part must be statically tagged", A);
2927 else
2928 Resolve_Record_Aggregate (N, Typ);
2929 end if;
2930 end if;
2931
2932 else
2933 Error_Msg_N ("no unique type for this aggregate", A);
2934 end if;
2935
2936 Check_Function_Writable_Actuals (N);
2937 end Resolve_Extension_Aggregate;
2938
2939 ------------------------------
2940 -- Resolve_Record_Aggregate --
2941 ------------------------------
2942
2943 procedure Resolve_Record_Aggregate (N : Node_Id; Typ : Entity_Id) is
2944 Assoc : Node_Id;
2945 -- N_Component_Association node belonging to the input aggregate N
2946
2947 Expr : Node_Id;
2948 Positional_Expr : Node_Id;
2949 Component : Entity_Id;
2950 Component_Elmt : Elmt_Id;
2951
2952 Components : constant Elist_Id := New_Elmt_List;
2953 -- Components is the list of the record components whose value must be
2954 -- provided in the aggregate. This list does include discriminants.
2955
2956 New_Assoc_List : constant List_Id := New_List;
2957 New_Assoc : Node_Id;
2958 -- New_Assoc_List is the newly built list of N_Component_Association
2959 -- nodes. New_Assoc is one such N_Component_Association node in it.
2960 -- Note that while Assoc and New_Assoc contain the same kind of nodes,
2961 -- they are used to iterate over two different N_Component_Association
2962 -- lists.
2963
2964 Others_Etype : Entity_Id := Empty;
2965 -- This variable is used to save the Etype of the last record component
2966 -- that takes its value from the others choice. Its purpose is:
2967 --
2968 -- (a) make sure the others choice is useful
2969 --
2970 -- (b) make sure the type of all the components whose value is
2971 -- subsumed by the others choice are the same.
2972 --
2973 -- This variable is updated as a side effect of function Get_Value.
2974
2975 Box_Node : Node_Id;
2976 Is_Box_Present : Boolean := False;
2977 Others_Box : Integer := 0;
2978
2979 -- Ada 2005 (AI-287): Variables used in case of default initialization
2980 -- to provide a functionality similar to Others_Etype. Box_Present
2981 -- indicates that the component takes its default initialization;
2982 -- Others_Box counts the number of components of the current aggregate
2983 -- (which may be a sub-aggregate of a larger one) that are default-
2984 -- initialized. A value of One indicates that an others_box is present.
2985 -- Any larger value indicates that the others_box is not redundant.
2986 -- These variables, similar to Others_Etype, are also updated as a
2987 -- side effect of function Get_Value.
2988 -- Box_Node is used to place a warning on a redundant others_box.
2989
2990 procedure Add_Association
2991 (Component : Entity_Id;
2992 Expr : Node_Id;
2993 Assoc_List : List_Id;
2994 Is_Box_Present : Boolean := False);
2995 -- Builds a new N_Component_Association node which associates Component
2996 -- to expression Expr and adds it to the association list being built,
2997 -- either New_Assoc_List, or the association being built for an inner
2998 -- aggregate.
2999
3000 function Discr_Present (Discr : Entity_Id) return Boolean;
3001 -- If aggregate N is a regular aggregate this routine will return True.
3002 -- Otherwise, if N is an extension aggregate, Discr is a discriminant
3003 -- whose value may already have been specified by N's ancestor part.
3004 -- This routine checks whether this is indeed the case and if so returns
3005 -- False, signaling that no value for Discr should appear in N's
3006 -- aggregate part. Also, in this case, the routine appends to
3007 -- New_Assoc_List the discriminant value specified in the ancestor part.
3008 --
3009 -- If the aggregate is in a context with expansion delayed, it will be
3010 -- reanalyzed. The inherited discriminant values must not be reinserted
3011 -- in the component list to prevent spurious errors, but they must be
3012 -- present on first analysis to build the proper subtype indications.
3013 -- The flag Inherited_Discriminant is used to prevent the re-insertion.
3014
3015 function Get_Value
3016 (Compon : Node_Id;
3017 From : List_Id;
3018 Consider_Others_Choice : Boolean := False)
3019 return Node_Id;
3020 -- Given a record component stored in parameter Compon, this function
3021 -- returns its value as it appears in the list From, which is a list
3022 -- of N_Component_Association nodes.
3023 --
3024 -- If no component association has a choice for the searched component,
3025 -- the value provided by the others choice is returned, if there is one,
3026 -- and Consider_Others_Choice is set to true. Otherwise Empty is
3027 -- returned. If there is more than one component association giving a
3028 -- value for the searched record component, an error message is emitted
3029 -- and the first found value is returned.
3030 --
3031 -- If Consider_Others_Choice is set and the returned expression comes
3032 -- from the others choice, then Others_Etype is set as a side effect.
3033 -- An error message is emitted if the components taking their value from
3034 -- the others choice do not have same type.
3035
3036 function New_Copy_Tree_And_Copy_Dimensions
3037 (Source : Node_Id;
3038 Map : Elist_Id := No_Elist;
3039 New_Sloc : Source_Ptr := No_Location;
3040 New_Scope : Entity_Id := Empty) return Node_Id;
3041 -- Same as New_Copy_Tree (defined in Sem_Util), except that this routine
3042 -- also copies the dimensions of Source to the returned node.
3043
3044 procedure Resolve_Aggr_Expr (Expr : Node_Id; Component : Node_Id);
3045 -- Analyzes and resolves expression Expr against the Etype of the
3046 -- Component. This routine also applies all appropriate checks to Expr.
3047 -- It finally saves a Expr in the newly created association list that
3048 -- will be attached to the final record aggregate. Note that if the
3049 -- Parent pointer of Expr is not set then Expr was produced with a
3050 -- New_Copy_Tree or some such.
3051
3052 ---------------------
3053 -- Add_Association --
3054 ---------------------
3055
3056 procedure Add_Association
3057 (Component : Entity_Id;
3058 Expr : Node_Id;
3059 Assoc_List : List_Id;
3060 Is_Box_Present : Boolean := False)
3061 is
3062 Loc : Source_Ptr;
3063 Choice_List : constant List_Id := New_List;
3064 New_Assoc : Node_Id;
3065
3066 begin
3067 -- If this is a box association the expression is missing, so
3068 -- use the Sloc of the aggregate itself for the new association.
3069
3070 if Present (Expr) then
3071 Loc := Sloc (Expr);
3072 else
3073 Loc := Sloc (N);
3074 end if;
3075
3076 Append (New_Occurrence_Of (Component, Loc), Choice_List);
3077 New_Assoc :=
3078 Make_Component_Association (Loc,
3079 Choices => Choice_List,
3080 Expression => Expr,
3081 Box_Present => Is_Box_Present);
3082 Append (New_Assoc, Assoc_List);
3083 end Add_Association;
3084
3085 -------------------
3086 -- Discr_Present --
3087 -------------------
3088
3089 function Discr_Present (Discr : Entity_Id) return Boolean is
3090 Regular_Aggr : constant Boolean := Nkind (N) /= N_Extension_Aggregate;
3091
3092 Loc : Source_Ptr;
3093
3094 Ancestor : Node_Id;
3095 Comp_Assoc : Node_Id;
3096 Discr_Expr : Node_Id;
3097
3098 Ancestor_Typ : Entity_Id;
3099 Orig_Discr : Entity_Id;
3100 D : Entity_Id;
3101 D_Val : Elmt_Id := No_Elmt; -- stop junk warning
3102
3103 Ancestor_Is_Subtyp : Boolean;
3104
3105 begin
3106 if Regular_Aggr then
3107 return True;
3108 end if;
3109
3110 -- Check whether inherited discriminant values have already been
3111 -- inserted in the aggregate. This will be the case if we are
3112 -- re-analyzing an aggregate whose expansion was delayed.
3113
3114 if Present (Component_Associations (N)) then
3115 Comp_Assoc := First (Component_Associations (N));
3116 while Present (Comp_Assoc) loop
3117 if Inherited_Discriminant (Comp_Assoc) then
3118 return True;
3119 end if;
3120
3121 Next (Comp_Assoc);
3122 end loop;
3123 end if;
3124
3125 Ancestor := Ancestor_Part (N);
3126 Ancestor_Typ := Etype (Ancestor);
3127 Loc := Sloc (Ancestor);
3128
3129 -- For a private type with unknown discriminants, use the underlying
3130 -- record view if it is available.
3131
3132 if Has_Unknown_Discriminants (Ancestor_Typ)
3133 and then Present (Full_View (Ancestor_Typ))
3134 and then Present (Underlying_Record_View (Full_View (Ancestor_Typ)))
3135 then
3136 Ancestor_Typ := Underlying_Record_View (Full_View (Ancestor_Typ));
3137 end if;
3138
3139 Ancestor_Is_Subtyp :=
3140 Is_Entity_Name (Ancestor) and then Is_Type (Entity (Ancestor));
3141
3142 -- If the ancestor part has no discriminants clearly N's aggregate
3143 -- part must provide a value for Discr.
3144
3145 if not Has_Discriminants (Ancestor_Typ) then
3146 return True;
3147
3148 -- If the ancestor part is an unconstrained subtype mark then the
3149 -- Discr must be present in N's aggregate part.
3150
3151 elsif Ancestor_Is_Subtyp
3152 and then not Is_Constrained (Entity (Ancestor))
3153 then
3154 return True;
3155 end if;
3156
3157 -- Now look to see if Discr was specified in the ancestor part
3158
3159 if Ancestor_Is_Subtyp then
3160 D_Val := First_Elmt (Discriminant_Constraint (Entity (Ancestor)));
3161 end if;
3162
3163 Orig_Discr := Original_Record_Component (Discr);
3164
3165 D := First_Discriminant (Ancestor_Typ);
3166 while Present (D) loop
3167
3168 -- If Ancestor has already specified Disc value then insert its
3169 -- value in the final aggregate.
3170
3171 if Original_Record_Component (D) = Orig_Discr then
3172 if Ancestor_Is_Subtyp then
3173 Discr_Expr := New_Copy_Tree (Node (D_Val));
3174 else
3175 Discr_Expr :=
3176 Make_Selected_Component (Loc,
3177 Prefix => Duplicate_Subexpr (Ancestor),
3178 Selector_Name => New_Occurrence_Of (Discr, Loc));
3179 end if;
3180
3181 Resolve_Aggr_Expr (Discr_Expr, Discr);
3182 Set_Inherited_Discriminant (Last (New_Assoc_List));
3183 return False;
3184 end if;
3185
3186 Next_Discriminant (D);
3187
3188 if Ancestor_Is_Subtyp then
3189 Next_Elmt (D_Val);
3190 end if;
3191 end loop;
3192
3193 return True;
3194 end Discr_Present;
3195
3196 ---------------
3197 -- Get_Value --
3198 ---------------
3199
3200 function Get_Value
3201 (Compon : Node_Id;
3202 From : List_Id;
3203 Consider_Others_Choice : Boolean := False)
3204 return Node_Id
3205 is
3206 Typ : constant Entity_Id := Etype (Compon);
3207 Assoc : Node_Id;
3208 Expr : Node_Id := Empty;
3209 Selector_Name : Node_Id;
3210
3211 begin
3212 Is_Box_Present := False;
3213
3214 if No (From) then
3215 return Empty;
3216 end if;
3217
3218 Assoc := First (From);
3219 while Present (Assoc) loop
3220 Selector_Name := First (Choices (Assoc));
3221 while Present (Selector_Name) loop
3222 if Nkind (Selector_Name) = N_Others_Choice then
3223 if Consider_Others_Choice and then No (Expr) then
3224
3225 -- We need to duplicate the expression for each
3226 -- successive component covered by the others choice.
3227 -- This is redundant if the others_choice covers only
3228 -- one component (small optimization possible???), but
3229 -- indispensable otherwise, because each one must be
3230 -- expanded individually to preserve side-effects.
3231
3232 -- Ada 2005 (AI-287): In case of default initialization
3233 -- of components, we duplicate the corresponding default
3234 -- expression (from the record type declaration). The
3235 -- copy must carry the sloc of the association (not the
3236 -- original expression) to prevent spurious elaboration
3237 -- checks when the default includes function calls.
3238
3239 if Box_Present (Assoc) then
3240 Others_Box := Others_Box + 1;
3241 Is_Box_Present := True;
3242
3243 if Expander_Active then
3244 return
3245 New_Copy_Tree_And_Copy_Dimensions
3246 (Expression (Parent (Compon)),
3247 New_Sloc => Sloc (Assoc));
3248 else
3249 return Expression (Parent (Compon));
3250 end if;
3251
3252 else
3253 if Present (Others_Etype)
3254 and then Base_Type (Others_Etype) /= Base_Type (Typ)
3255 then
3256 -- If the components are of an anonymous access
3257 -- type they are distinct, but this is legal in
3258 -- Ada 2012 as long as designated types match.
3259
3260 if (Ekind (Typ) = E_Anonymous_Access_Type
3261 or else Ekind (Typ) =
3262 E_Anonymous_Access_Subprogram_Type)
3263 and then Designated_Type (Typ) =
3264 Designated_Type (Others_Etype)
3265 then
3266 null;
3267 else
3268 Error_Msg_N
3269 ("components in OTHERS choice must "
3270 & "have same type", Selector_Name);
3271 end if;
3272 end if;
3273
3274 Others_Etype := Typ;
3275
3276 -- Copy expression so that it is resolved
3277 -- independently for each component, This is needed
3278 -- for accessibility checks on compoents of anonymous
3279 -- access types, even in compile_only mode.
3280
3281 if not Inside_A_Generic then
3282
3283 -- In ASIS mode, preanalyze the expression in an
3284 -- others association before making copies for
3285 -- separate resolution and accessibility checks.
3286 -- This ensures that the type of the expression is
3287 -- available to ASIS in all cases, in particular if
3288 -- the expression is itself an aggregate.
3289
3290 if ASIS_Mode then
3291 Preanalyze_And_Resolve (Expression (Assoc), Typ);
3292 end if;
3293
3294 return
3295 New_Copy_Tree_And_Copy_Dimensions
3296 (Expression (Assoc));
3297
3298 else
3299 return Expression (Assoc);
3300 end if;
3301 end if;
3302 end if;
3303
3304 elsif Chars (Compon) = Chars (Selector_Name) then
3305 if No (Expr) then
3306
3307 -- Ada 2005 (AI-231)
3308
3309 if Ada_Version >= Ada_2005
3310 and then Known_Null (Expression (Assoc))
3311 then
3312 Check_Can_Never_Be_Null (Compon, Expression (Assoc));
3313 end if;
3314
3315 -- We need to duplicate the expression when several
3316 -- components are grouped together with a "|" choice.
3317 -- For instance "filed1 | filed2 => Expr"
3318
3319 -- Ada 2005 (AI-287)
3320
3321 if Box_Present (Assoc) then
3322 Is_Box_Present := True;
3323
3324 -- Duplicate the default expression of the component
3325 -- from the record type declaration, so a new copy
3326 -- can be attached to the association.
3327
3328 -- Note that we always copy the default expression,
3329 -- even when the association has a single choice, in
3330 -- order to create a proper association for the
3331 -- expanded aggregate.
3332
3333 -- Component may have no default, in which case the
3334 -- expression is empty and the component is default-
3335 -- initialized, but an association for the component
3336 -- exists, and it is not covered by an others clause.
3337
3338 -- Scalar and private types have no initialization
3339 -- procedure, so they remain uninitialized. If the
3340 -- target of the aggregate is a constant this
3341 -- deserves a warning.
3342
3343 if No (Expression (Parent (Compon)))
3344 and then not Has_Non_Null_Base_Init_Proc (Typ)
3345 and then not Has_Aspect (Typ, Aspect_Default_Value)
3346 and then not Is_Concurrent_Type (Typ)
3347 and then Nkind (Parent (N)) = N_Object_Declaration
3348 and then Constant_Present (Parent (N))
3349 then
3350 Error_Msg_Node_2 := Typ;
3351 Error_Msg_NE
3352 ("component&? of type& is uninitialized",
3353 Assoc, Selector_Name);
3354
3355 -- An additional reminder if the component type
3356 -- is a generic formal.
3357
3358 if Is_Generic_Type (Base_Type (Typ)) then
3359 Error_Msg_NE
3360 ("\instance should provide actual type with "
3361 & "initialization for&", Assoc, Typ);
3362 end if;
3363 end if;
3364
3365 return
3366 New_Copy_Tree_And_Copy_Dimensions
3367 (Expression (Parent (Compon)));
3368
3369 else
3370 if Present (Next (Selector_Name)) then
3371 Expr := New_Copy_Tree_And_Copy_Dimensions
3372 (Expression (Assoc));
3373 else
3374 Expr := Expression (Assoc);
3375 end if;
3376 end if;
3377
3378 Generate_Reference (Compon, Selector_Name, 'm');
3379
3380 else
3381 Error_Msg_NE
3382 ("more than one value supplied for &",
3383 Selector_Name, Compon);
3384
3385 end if;
3386 end if;
3387
3388 Next (Selector_Name);
3389 end loop;
3390
3391 Next (Assoc);
3392 end loop;
3393
3394 return Expr;
3395 end Get_Value;
3396
3397 ---------------------------------------
3398 -- New_Copy_Tree_And_Copy_Dimensions --
3399 ---------------------------------------
3400
3401 function New_Copy_Tree_And_Copy_Dimensions
3402 (Source : Node_Id;
3403 Map : Elist_Id := No_Elist;
3404 New_Sloc : Source_Ptr := No_Location;
3405 New_Scope : Entity_Id := Empty) return Node_Id
3406 is
3407 New_Copy : constant Node_Id :=
3408 New_Copy_Tree (Source, Map, New_Sloc, New_Scope);
3409
3410 begin
3411 -- Move the dimensions of Source to New_Copy
3412
3413 Copy_Dimensions (Source, New_Copy);
3414 return New_Copy;
3415 end New_Copy_Tree_And_Copy_Dimensions;
3416
3417 -----------------------
3418 -- Resolve_Aggr_Expr --
3419 -----------------------
3420
3421 procedure Resolve_Aggr_Expr (Expr : Node_Id; Component : Node_Id) is
3422 function Has_Expansion_Delayed (Expr : Node_Id) return Boolean;
3423 -- If the expression is an aggregate (possibly qualified) then its
3424 -- expansion is delayed until the enclosing aggregate is expanded
3425 -- into assignments. In that case, do not generate checks on the
3426 -- expression, because they will be generated later, and will other-
3427 -- wise force a copy (to remove side-effects) that would leave a
3428 -- dynamic-sized aggregate in the code, something that gigi cannot
3429 -- handle.
3430
3431 ---------------------------
3432 -- Has_Expansion_Delayed --
3433 ---------------------------
3434
3435 function Has_Expansion_Delayed (Expr : Node_Id) return Boolean is
3436 Kind : constant Node_Kind := Nkind (Expr);
3437 begin
3438 return (Nkind_In (Kind, N_Aggregate, N_Extension_Aggregate)
3439 and then Present (Etype (Expr))
3440 and then Is_Record_Type (Etype (Expr))
3441 and then Expansion_Delayed (Expr))
3442 or else (Kind = N_Qualified_Expression
3443 and then Has_Expansion_Delayed (Expression (Expr)));
3444 end Has_Expansion_Delayed;
3445
3446 -- Local variables
3447
3448 Expr_Type : Entity_Id := Empty;
3449 New_C : Entity_Id := Component;
3450 New_Expr : Node_Id;
3451
3452 Relocate : Boolean;
3453 -- Set to True if the resolved Expr node needs to be relocated when
3454 -- attached to the newly created association list. This node need not
3455 -- be relocated if its parent pointer is not set. In fact in this
3456 -- case Expr is the output of a New_Copy_Tree call. If Relocate is
3457 -- True then we have analyzed the expression node in the original
3458 -- aggregate and hence it needs to be relocated when moved over to
3459 -- the new association list.
3460
3461 -- Start of processing for Resolve_Aggr_Expr
3462
3463 begin
3464 -- If the type of the component is elementary or the type of the
3465 -- aggregate does not contain discriminants, use the type of the
3466 -- component to resolve Expr.
3467
3468 if Is_Elementary_Type (Etype (Component))
3469 or else not Has_Discriminants (Etype (N))
3470 then
3471 Expr_Type := Etype (Component);
3472
3473 -- Otherwise we have to pick up the new type of the component from
3474 -- the new constrained subtype of the aggregate. In fact components
3475 -- which are of a composite type might be constrained by a
3476 -- discriminant, and we want to resolve Expr against the subtype were
3477 -- all discriminant occurrences are replaced with their actual value.
3478
3479 else
3480 New_C := First_Component (Etype (N));
3481 while Present (New_C) loop
3482 if Chars (New_C) = Chars (Component) then
3483 Expr_Type := Etype (New_C);
3484 exit;
3485 end if;
3486
3487 Next_Component (New_C);
3488 end loop;
3489
3490 pragma Assert (Present (Expr_Type));
3491
3492 -- For each range in an array type where a discriminant has been
3493 -- replaced with the constraint, check that this range is within
3494 -- the range of the base type. This checks is done in the init
3495 -- proc for regular objects, but has to be done here for
3496 -- aggregates since no init proc is called for them.
3497
3498 if Is_Array_Type (Expr_Type) then
3499 declare
3500 Index : Node_Id;
3501 -- Range of the current constrained index in the array
3502
3503 Orig_Index : Node_Id := First_Index (Etype (Component));
3504 -- Range corresponding to the range Index above in the
3505 -- original unconstrained record type. The bounds of this
3506 -- range may be governed by discriminants.
3507
3508 Unconstr_Index : Node_Id := First_Index (Etype (Expr_Type));
3509 -- Range corresponding to the range Index above for the
3510 -- unconstrained array type. This range is needed to apply
3511 -- range checks.
3512
3513 begin
3514 Index := First_Index (Expr_Type);
3515 while Present (Index) loop
3516 if Depends_On_Discriminant (Orig_Index) then
3517 Apply_Range_Check (Index, Etype (Unconstr_Index));
3518 end if;
3519
3520 Next_Index (Index);
3521 Next_Index (Orig_Index);
3522 Next_Index (Unconstr_Index);
3523 end loop;
3524 end;
3525 end if;
3526 end if;
3527
3528 -- If the Parent pointer of Expr is not set, Expr is an expression
3529 -- duplicated by New_Tree_Copy (this happens for record aggregates
3530 -- that look like (Field1 | Filed2 => Expr) or (others => Expr)).
3531 -- Such a duplicated expression must be attached to the tree
3532 -- before analysis and resolution to enforce the rule that a tree
3533 -- fragment should never be analyzed or resolved unless it is
3534 -- attached to the current compilation unit.
3535
3536 if No (Parent (Expr)) then
3537 Set_Parent (Expr, N);
3538 Relocate := False;
3539 else
3540 Relocate := True;
3541 end if;
3542
3543 Analyze_And_Resolve (Expr, Expr_Type);
3544 Check_Expr_OK_In_Limited_Aggregate (Expr);
3545 Check_Non_Static_Context (Expr);
3546 Check_Unset_Reference (Expr);
3547
3548 -- Check wrong use of class-wide types
3549
3550 if Is_Class_Wide_Type (Etype (Expr)) then
3551 Error_Msg_N ("dynamically tagged expression not allowed", Expr);
3552 end if;
3553
3554 if not Has_Expansion_Delayed (Expr) then
3555 Aggregate_Constraint_Checks (Expr, Expr_Type);
3556 end if;
3557
3558 -- If an aggregate component has a type with predicates, an explicit
3559 -- predicate check must be applied, as for an assignment statement,
3560 -- because the aggegate might not be expanded into individual
3561 -- component assignments.
3562
3563 if Present (Predicate_Function (Expr_Type))
3564 and then Analyzed (Expr)
3565 then
3566 Apply_Predicate_Check (Expr, Expr_Type);
3567 end if;
3568
3569 if Raises_Constraint_Error (Expr) then
3570 Set_Raises_Constraint_Error (N);
3571 end if;
3572
3573 -- If the expression has been marked as requiring a range check, then
3574 -- generate it here. It's a bit odd to be generating such checks in
3575 -- the analyzer, but harmless since Generate_Range_Check does nothing
3576 -- (other than making sure Do_Range_Check is set) if the expander is
3577 -- not active.
3578
3579 if Do_Range_Check (Expr) then
3580 Generate_Range_Check (Expr, Expr_Type, CE_Range_Check_Failed);
3581 end if;
3582
3583 if Relocate then
3584 New_Expr := Relocate_Node (Expr);
3585
3586 -- Since New_Expr is not gonna be analyzed later on, we need to
3587 -- propagate here the dimensions form Expr to New_Expr.
3588
3589 Copy_Dimensions (Expr, New_Expr);
3590
3591 else
3592 New_Expr := Expr;
3593 end if;
3594
3595 Add_Association (New_C, New_Expr, New_Assoc_List);
3596 end Resolve_Aggr_Expr;
3597
3598 -- Start of processing for Resolve_Record_Aggregate
3599
3600 begin
3601 -- A record aggregate is restricted in SPARK:
3602
3603 -- Each named association can have only a single choice.
3604 -- OTHERS cannot be used.
3605 -- Positional and named associations cannot be mixed.
3606
3607 if Present (Component_Associations (N))
3608 and then Present (First (Component_Associations (N)))
3609 then
3610
3611 if Present (Expressions (N)) then
3612 Check_SPARK_05_Restriction
3613 ("named association cannot follow positional one",
3614 First (Choices (First (Component_Associations (N)))));
3615 end if;
3616
3617 declare
3618 Assoc : Node_Id;
3619
3620 begin
3621 Assoc := First (Component_Associations (N));
3622 while Present (Assoc) loop
3623 if List_Length (Choices (Assoc)) > 1 then
3624 Check_SPARK_05_Restriction
3625 ("component association in record aggregate must "
3626 & "contain a single choice", Assoc);
3627 end if;
3628
3629 if Nkind (First (Choices (Assoc))) = N_Others_Choice then
3630 Check_SPARK_05_Restriction
3631 ("record aggregate cannot contain OTHERS", Assoc);
3632 end if;
3633
3634 Assoc := Next (Assoc);
3635 end loop;
3636 end;
3637 end if;
3638
3639 -- We may end up calling Duplicate_Subexpr on expressions that are
3640 -- attached to New_Assoc_List. For this reason we need to attach it
3641 -- to the tree by setting its parent pointer to N. This parent point
3642 -- will change in STEP 8 below.
3643
3644 Set_Parent (New_Assoc_List, N);
3645
3646 -- STEP 1: abstract type and null record verification
3647
3648 if Is_Abstract_Type (Typ) then
3649 Error_Msg_N ("type of aggregate cannot be abstract", N);
3650 end if;
3651
3652 if No (First_Entity (Typ)) and then Null_Record_Present (N) then
3653 Set_Etype (N, Typ);
3654 return;
3655
3656 elsif Present (First_Entity (Typ))
3657 and then Null_Record_Present (N)
3658 and then not Is_Tagged_Type (Typ)
3659 then
3660 Error_Msg_N ("record aggregate cannot be null", N);
3661 return;
3662
3663 -- If the type has no components, then the aggregate should either
3664 -- have "null record", or in Ada 2005 it could instead have a single
3665 -- component association given by "others => <>". For Ada 95 we flag an
3666 -- error at this point, but for Ada 2005 we proceed with checking the
3667 -- associations below, which will catch the case where it's not an
3668 -- aggregate with "others => <>". Note that the legality of a <>
3669 -- aggregate for a null record type was established by AI05-016.
3670
3671 elsif No (First_Entity (Typ))
3672 and then Ada_Version < Ada_2005
3673 then
3674 Error_Msg_N ("record aggregate must be null", N);
3675 return;
3676 end if;
3677
3678 -- STEP 2: Verify aggregate structure
3679
3680 Step_2 : declare
3681 Selector_Name : Node_Id;
3682 Bad_Aggregate : Boolean := False;
3683
3684 begin
3685 if Present (Component_Associations (N)) then
3686 Assoc := First (Component_Associations (N));
3687 else
3688 Assoc := Empty;
3689 end if;
3690
3691 while Present (Assoc) loop
3692 Selector_Name := First (Choices (Assoc));
3693 while Present (Selector_Name) loop
3694 if Nkind (Selector_Name) = N_Identifier then
3695 null;
3696
3697 elsif Nkind (Selector_Name) = N_Others_Choice then
3698 if Selector_Name /= First (Choices (Assoc))
3699 or else Present (Next (Selector_Name))
3700 then
3701 Error_Msg_N
3702 ("OTHERS must appear alone in a choice list",
3703 Selector_Name);
3704 return;
3705
3706 elsif Present (Next (Assoc)) then
3707 Error_Msg_N
3708 ("OTHERS must appear last in an aggregate",
3709 Selector_Name);
3710 return;
3711
3712 -- (Ada 2005): If this is an association with a box,
3713 -- indicate that the association need not represent
3714 -- any component.
3715
3716 elsif Box_Present (Assoc) then
3717 Others_Box := 1;
3718 Box_Node := Assoc;
3719 end if;
3720
3721 else
3722 Error_Msg_N
3723 ("selector name should be identifier or OTHERS",
3724 Selector_Name);
3725 Bad_Aggregate := True;
3726 end if;
3727
3728 Next (Selector_Name);
3729 end loop;
3730
3731 Next (Assoc);
3732 end loop;
3733
3734 if Bad_Aggregate then
3735 return;
3736 end if;
3737 end Step_2;
3738
3739 -- STEP 3: Find discriminant Values
3740
3741 Step_3 : declare
3742 Discrim : Entity_Id;
3743 Missing_Discriminants : Boolean := False;
3744
3745 begin
3746 if Present (Expressions (N)) then
3747 Positional_Expr := First (Expressions (N));
3748 else
3749 Positional_Expr := Empty;
3750 end if;
3751
3752 -- AI05-0115: if the ancestor part is a subtype mark, the ancestor
3753 -- must not have unknown discriminants.
3754
3755 if Is_Derived_Type (Typ)
3756 and then Has_Unknown_Discriminants (Root_Type (Typ))
3757 and then Nkind (N) /= N_Extension_Aggregate
3758 then
3759 Error_Msg_NE
3760 ("aggregate not available for type& whose ancestor "
3761 & "has unknown discriminants ", N, Typ);
3762 end if;
3763
3764 if Has_Unknown_Discriminants (Typ)
3765 and then Present (Underlying_Record_View (Typ))
3766 then
3767 Discrim := First_Discriminant (Underlying_Record_View (Typ));
3768 elsif Has_Discriminants (Typ) then
3769 Discrim := First_Discriminant (Typ);
3770 else
3771 Discrim := Empty;
3772 end if;
3773
3774 -- First find the discriminant values in the positional components
3775
3776 while Present (Discrim) and then Present (Positional_Expr) loop
3777 if Discr_Present (Discrim) then
3778 Resolve_Aggr_Expr (Positional_Expr, Discrim);
3779
3780 -- Ada 2005 (AI-231)
3781
3782 if Ada_Version >= Ada_2005
3783 and then Known_Null (Positional_Expr)
3784 then
3785 Check_Can_Never_Be_Null (Discrim, Positional_Expr);
3786 end if;
3787
3788 Next (Positional_Expr);
3789 end if;
3790
3791 if Present (Get_Value (Discrim, Component_Associations (N))) then
3792 Error_Msg_NE
3793 ("more than one value supplied for discriminant&",
3794 N, Discrim);
3795 end if;
3796
3797 Next_Discriminant (Discrim);
3798 end loop;
3799
3800 -- Find remaining discriminant values if any among named components
3801
3802 while Present (Discrim) loop
3803 Expr := Get_Value (Discrim, Component_Associations (N), True);
3804
3805 if not Discr_Present (Discrim) then
3806 if Present (Expr) then
3807 Error_Msg_NE
3808 ("more than one value supplied for discriminant &",
3809 N, Discrim);
3810 end if;
3811
3812 elsif No (Expr) then
3813 Error_Msg_NE
3814 ("no value supplied for discriminant &", N, Discrim);
3815 Missing_Discriminants := True;
3816
3817 else
3818 Resolve_Aggr_Expr (Expr, Discrim);
3819 end if;
3820
3821 Next_Discriminant (Discrim);
3822 end loop;
3823
3824 if Missing_Discriminants then
3825 return;
3826 end if;
3827
3828 -- At this point and until the beginning of STEP 6, New_Assoc_List
3829 -- contains only the discriminants and their values.
3830
3831 end Step_3;
3832
3833 -- STEP 4: Set the Etype of the record aggregate
3834
3835 -- ??? This code is pretty much a copy of Sem_Ch3.Build_Subtype. That
3836 -- routine should really be exported in sem_util or some such and used
3837 -- in sem_ch3 and here rather than have a copy of the code which is a
3838 -- maintenance nightmare.
3839
3840 -- ??? Performance WARNING. The current implementation creates a new
3841 -- itype for all aggregates whose base type is discriminated. This means
3842 -- that for record aggregates nested inside an array aggregate we will
3843 -- create a new itype for each record aggregate if the array component
3844 -- type has discriminants. For large aggregates this may be a problem.
3845 -- What should be done in this case is to reuse itypes as much as
3846 -- possible.
3847
3848 if Has_Discriminants (Typ)
3849 or else (Has_Unknown_Discriminants (Typ)
3850 and then Present (Underlying_Record_View (Typ)))
3851 then
3852 Build_Constrained_Itype : declare
3853 Loc : constant Source_Ptr := Sloc (N);
3854 Indic : Node_Id;
3855 Subtyp_Decl : Node_Id;
3856 Def_Id : Entity_Id;
3857
3858 C : constant List_Id := New_List;
3859
3860 begin
3861 New_Assoc := First (New_Assoc_List);
3862 while Present (New_Assoc) loop
3863 Append (Duplicate_Subexpr (Expression (New_Assoc)), To => C);
3864 Next (New_Assoc);
3865 end loop;
3866
3867 if Has_Unknown_Discriminants (Typ)
3868 and then Present (Underlying_Record_View (Typ))
3869 then
3870 Indic :=
3871 Make_Subtype_Indication (Loc,
3872 Subtype_Mark =>
3873 New_Occurrence_Of (Underlying_Record_View (Typ), Loc),
3874 Constraint =>
3875 Make_Index_Or_Discriminant_Constraint (Loc, C));
3876 else
3877 Indic :=
3878 Make_Subtype_Indication (Loc,
3879 Subtype_Mark =>
3880 New_Occurrence_Of (Base_Type (Typ), Loc),
3881 Constraint =>
3882 Make_Index_Or_Discriminant_Constraint (Loc, C));
3883 end if;
3884
3885 Def_Id := Create_Itype (Ekind (Typ), N);
3886
3887 Subtyp_Decl :=
3888 Make_Subtype_Declaration (Loc,
3889 Defining_Identifier => Def_Id,
3890 Subtype_Indication => Indic);
3891 Set_Parent (Subtyp_Decl, Parent (N));
3892
3893 -- Itypes must be analyzed with checks off (see itypes.ads)
3894
3895 Analyze (Subtyp_Decl, Suppress => All_Checks);
3896
3897 Set_Etype (N, Def_Id);
3898 Check_Static_Discriminated_Subtype
3899 (Def_Id, Expression (First (New_Assoc_List)));
3900 end Build_Constrained_Itype;
3901
3902 else
3903 Set_Etype (N, Typ);
3904 end if;
3905
3906 -- STEP 5: Get remaining components according to discriminant values
3907
3908 Step_5 : declare
3909 Record_Def : Node_Id;
3910 Parent_Typ : Entity_Id;
3911 Root_Typ : Entity_Id;
3912 Parent_Typ_List : Elist_Id;
3913 Parent_Elmt : Elmt_Id;
3914 Errors_Found : Boolean := False;
3915 Dnode : Node_Id;
3916
3917 function Find_Private_Ancestor return Entity_Id;
3918 -- AI05-0115: Find earlier ancestor in the derivation chain that is
3919 -- derived from a private view. Whether the aggregate is legal
3920 -- depends on the current visibility of the type as well as that
3921 -- of the parent of the ancestor.
3922
3923 ---------------------------
3924 -- Find_Private_Ancestor --
3925 ---------------------------
3926
3927 function Find_Private_Ancestor return Entity_Id is
3928 Par : Entity_Id;
3929
3930 begin
3931 Par := Typ;
3932 loop
3933 if Has_Private_Ancestor (Par)
3934 and then not Has_Private_Ancestor (Etype (Base_Type (Par)))
3935 then
3936 return Par;
3937
3938 elsif not Is_Derived_Type (Par) then
3939 return Empty;
3940
3941 else
3942 Par := Etype (Base_Type (Par));
3943 end if;
3944 end loop;
3945 end Find_Private_Ancestor;
3946
3947 -- Start of processing for Step_5
3948
3949 begin
3950 if Is_Derived_Type (Typ) and then Is_Tagged_Type (Typ) then
3951 Parent_Typ_List := New_Elmt_List;
3952
3953 -- If this is an extension aggregate, the component list must
3954 -- include all components that are not in the given ancestor type.
3955 -- Otherwise, the component list must include components of all
3956 -- ancestors, starting with the root.
3957
3958 if Nkind (N) = N_Extension_Aggregate then
3959 Root_Typ := Base_Type (Etype (Ancestor_Part (N)));
3960
3961 else
3962 -- AI05-0115: check legality of aggregate for type with
3963 -- aa private ancestor.
3964
3965 Root_Typ := Root_Type (Typ);
3966 if Has_Private_Ancestor (Typ) then
3967 declare
3968 Ancestor : constant Entity_Id :=
3969 Find_Private_Ancestor;
3970 Ancestor_Unit : constant Entity_Id :=
3971 Cunit_Entity (Get_Source_Unit (Ancestor));
3972 Parent_Unit : constant Entity_Id :=
3973 Cunit_Entity
3974 (Get_Source_Unit (Base_Type (Etype (Ancestor))));
3975 begin
3976 -- Check whether we are in a scope that has full view
3977 -- over the private ancestor and its parent. This can
3978 -- only happen if the derivation takes place in a child
3979 -- unit of the unit that declares the parent, and we are
3980 -- in the private part or body of that child unit, else
3981 -- the aggregate is illegal.
3982
3983 if Is_Child_Unit (Ancestor_Unit)
3984 and then Scope (Ancestor_Unit) = Parent_Unit
3985 and then In_Open_Scopes (Scope (Ancestor))
3986 and then
3987 (In_Private_Part (Scope (Ancestor))
3988 or else In_Package_Body (Scope (Ancestor)))
3989 then
3990 null;
3991
3992 else
3993 Error_Msg_NE
3994 ("type of aggregate has private ancestor&!",
3995 N, Root_Typ);
3996 Error_Msg_N ("must use extension aggregate!", N);
3997 return;
3998 end if;
3999 end;
4000 end if;
4001
4002 Dnode := Declaration_Node (Base_Type (Root_Typ));
4003
4004 -- If we don't get a full declaration, then we have some error
4005 -- which will get signalled later so skip this part. Otherwise
4006 -- gather components of root that apply to the aggregate type.
4007 -- We use the base type in case there is an applicable stored
4008 -- constraint that renames the discriminants of the root.
4009
4010 if Nkind (Dnode) = N_Full_Type_Declaration then
4011 Record_Def := Type_Definition (Dnode);
4012 Gather_Components
4013 (Base_Type (Typ),
4014 Component_List (Record_Def),
4015 Governed_By => New_Assoc_List,
4016 Into => Components,
4017 Report_Errors => Errors_Found);
4018
4019 if Errors_Found then
4020 Error_Msg_N
4021 ("discriminant controlling variant part is not static",
4022 N);
4023 return;
4024 end if;
4025 end if;
4026 end if;
4027
4028 Parent_Typ := Base_Type (Typ);
4029 while Parent_Typ /= Root_Typ loop
4030 Prepend_Elmt (Parent_Typ, To => Parent_Typ_List);
4031 Parent_Typ := Etype (Parent_Typ);
4032
4033 if Nkind (Parent (Base_Type (Parent_Typ))) =
4034 N_Private_Type_Declaration
4035 or else Nkind (Parent (Base_Type (Parent_Typ))) =
4036 N_Private_Extension_Declaration
4037 then
4038 if Nkind (N) /= N_Extension_Aggregate then
4039 Error_Msg_NE
4040 ("type of aggregate has private ancestor&!",
4041 N, Parent_Typ);
4042 Error_Msg_N ("must use extension aggregate!", N);
4043 return;
4044
4045 elsif Parent_Typ /= Root_Typ then
4046 Error_Msg_NE
4047 ("ancestor part of aggregate must be private type&",
4048 Ancestor_Part (N), Parent_Typ);
4049 return;
4050 end if;
4051
4052 -- The current view of ancestor part may be a private type,
4053 -- while the context type is always non-private.
4054
4055 elsif Is_Private_Type (Root_Typ)
4056 and then Present (Full_View (Root_Typ))
4057 and then Nkind (N) = N_Extension_Aggregate
4058 then
4059 exit when Base_Type (Full_View (Root_Typ)) = Parent_Typ;
4060 end if;
4061 end loop;
4062
4063 -- Now collect components from all other ancestors, beginning
4064 -- with the current type. If the type has unknown discriminants
4065 -- use the component list of the Underlying_Record_View, which
4066 -- needs to be used for the subsequent expansion of the aggregate
4067 -- into assignments.
4068
4069 Parent_Elmt := First_Elmt (Parent_Typ_List);
4070 while Present (Parent_Elmt) loop
4071 Parent_Typ := Node (Parent_Elmt);
4072
4073 if Has_Unknown_Discriminants (Parent_Typ)
4074 and then Present (Underlying_Record_View (Typ))
4075 then
4076 Parent_Typ := Underlying_Record_View (Parent_Typ);
4077 end if;
4078
4079 Record_Def := Type_Definition (Parent (Base_Type (Parent_Typ)));
4080 Gather_Components (Empty,
4081 Component_List (Record_Extension_Part (Record_Def)),
4082 Governed_By => New_Assoc_List,
4083 Into => Components,
4084 Report_Errors => Errors_Found);
4085
4086 Next_Elmt (Parent_Elmt);
4087 end loop;
4088
4089 -- Typ is not a derived tagged type
4090
4091 else
4092 Record_Def := Type_Definition (Parent (Base_Type (Typ)));
4093
4094 if Null_Present (Record_Def) then
4095 null;
4096
4097 elsif not Has_Unknown_Discriminants (Typ) then
4098 Gather_Components
4099 (Base_Type (Typ),
4100 Component_List (Record_Def),
4101 Governed_By => New_Assoc_List,
4102 Into => Components,
4103 Report_Errors => Errors_Found);
4104
4105 else
4106 Gather_Components
4107 (Base_Type (Underlying_Record_View (Typ)),
4108 Component_List (Record_Def),
4109 Governed_By => New_Assoc_List,
4110 Into => Components,
4111 Report_Errors => Errors_Found);
4112 end if;
4113 end if;
4114
4115 if Errors_Found then
4116 return;
4117 end if;
4118 end Step_5;
4119
4120 -- STEP 6: Find component Values
4121
4122 Component := Empty;
4123 Component_Elmt := First_Elmt (Components);
4124
4125 -- First scan the remaining positional associations in the aggregate.
4126 -- Remember that at this point Positional_Expr contains the current
4127 -- positional association if any is left after looking for discriminant
4128 -- values in step 3.
4129
4130 while Present (Positional_Expr) and then Present (Component_Elmt) loop
4131 Component := Node (Component_Elmt);
4132 Resolve_Aggr_Expr (Positional_Expr, Component);
4133
4134 -- Ada 2005 (AI-231)
4135
4136 if Ada_Version >= Ada_2005 and then Known_Null (Positional_Expr) then
4137 Check_Can_Never_Be_Null (Component, Positional_Expr);
4138 end if;
4139
4140 if Present (Get_Value (Component, Component_Associations (N))) then
4141 Error_Msg_NE
4142 ("more than one value supplied for Component &", N, Component);
4143 end if;
4144
4145 Next (Positional_Expr);
4146 Next_Elmt (Component_Elmt);
4147 end loop;
4148
4149 if Present (Positional_Expr) then
4150 Error_Msg_N
4151 ("too many components for record aggregate", Positional_Expr);
4152 end if;
4153
4154 -- Now scan for the named arguments of the aggregate
4155
4156 while Present (Component_Elmt) loop
4157 Component := Node (Component_Elmt);
4158 Expr := Get_Value (Component, Component_Associations (N), True);
4159
4160 -- Note: The previous call to Get_Value sets the value of the
4161 -- variable Is_Box_Present.
4162
4163 -- Ada 2005 (AI-287): Handle components with default initialization.
4164 -- Note: This feature was originally added to Ada 2005 for limited
4165 -- but it was finally allowed with any type.
4166
4167 if Is_Box_Present then
4168 Check_Box_Component : declare
4169 Ctyp : constant Entity_Id := Etype (Component);
4170
4171 begin
4172 -- If there is a default expression for the aggregate, copy
4173 -- it into a new association. This copy must modify the scopes
4174 -- of internal types that may be attached to the expression
4175 -- (e.g. index subtypes of arrays) because in general the type
4176 -- declaration and the aggregate appear in different scopes,
4177 -- and the backend requires the scope of the type to match the
4178 -- point at which it is elaborated.
4179
4180 -- If the component has an initialization procedure (IP) we
4181 -- pass the component to the expander, which will generate
4182 -- the call to such IP.
4183
4184 -- If the component has discriminants, their values must
4185 -- be taken from their subtype. This is indispensable for
4186 -- constraints that are given by the current instance of an
4187 -- enclosing type, to allow the expansion of the aggregate to
4188 -- replace the reference to the current instance by the target
4189 -- object of the aggregate.
4190
4191 if Present (Parent (Component))
4192 and then
4193 Nkind (Parent (Component)) = N_Component_Declaration
4194 and then Present (Expression (Parent (Component)))
4195 then
4196 Expr :=
4197 New_Copy_Tree_And_Copy_Dimensions
4198 (Expression (Parent (Component)),
4199 New_Scope => Current_Scope,
4200 New_Sloc => Sloc (N));
4201
4202 Add_Association
4203 (Component => Component,
4204 Expr => Expr,
4205 Assoc_List => New_Assoc_List);
4206 Set_Has_Self_Reference (N);
4207
4208 -- A box-defaulted access component gets the value null. Also
4209 -- included are components of private types whose underlying
4210 -- type is an access type. In either case set the type of the
4211 -- literal, for subsequent use in semantic checks.
4212
4213 elsif Present (Underlying_Type (Ctyp))
4214 and then Is_Access_Type (Underlying_Type (Ctyp))
4215 then
4216 if not Is_Private_Type (Ctyp) then
4217 Expr := Make_Null (Sloc (N));
4218 Set_Etype (Expr, Ctyp);
4219 Add_Association
4220 (Component => Component,
4221 Expr => Expr,
4222 Assoc_List => New_Assoc_List);
4223
4224 -- If the component's type is private with an access type as
4225 -- its underlying type then we have to create an unchecked
4226 -- conversion to satisfy type checking.
4227
4228 else
4229 declare
4230 Qual_Null : constant Node_Id :=
4231 Make_Qualified_Expression (Sloc (N),
4232 Subtype_Mark =>
4233 New_Occurrence_Of
4234 (Underlying_Type (Ctyp), Sloc (N)),
4235 Expression => Make_Null (Sloc (N)));
4236
4237 Convert_Null : constant Node_Id :=
4238 Unchecked_Convert_To
4239 (Ctyp, Qual_Null);
4240
4241 begin
4242 Analyze_And_Resolve (Convert_Null, Ctyp);
4243 Add_Association
4244 (Component => Component,
4245 Expr => Convert_Null,
4246 Assoc_List => New_Assoc_List);
4247 end;
4248 end if;
4249
4250 -- Ada 2012: If component is scalar with default value, use it
4251
4252 elsif Is_Scalar_Type (Ctyp)
4253 and then Has_Default_Aspect (Ctyp)
4254 then
4255 Add_Association
4256 (Component => Component,
4257 Expr => Default_Aspect_Value
4258 (First_Subtype (Underlying_Type (Ctyp))),
4259 Assoc_List => New_Assoc_List);
4260
4261 elsif Has_Non_Null_Base_Init_Proc (Ctyp)
4262 or else not Expander_Active
4263 then
4264 if Is_Record_Type (Ctyp)
4265 and then Has_Discriminants (Ctyp)
4266 and then not Is_Private_Type (Ctyp)
4267 then
4268 -- We build a partially initialized aggregate with the
4269 -- values of the discriminants and box initialization
4270 -- for the rest, if other components are present.
4271
4272 -- The type of the aggregate is the known subtype of
4273 -- the component. The capture of discriminants must
4274 -- be recursive because subcomponents may be constrained
4275 -- (transitively) by discriminants of enclosing types.
4276 -- For a private type with discriminants, a call to the
4277 -- initialization procedure will be generated, and no
4278 -- subaggregate is needed.
4279
4280 Capture_Discriminants : declare
4281 Loc : constant Source_Ptr := Sloc (N);
4282 Expr : Node_Id;
4283
4284 procedure Add_Discriminant_Values
4285 (New_Aggr : Node_Id;
4286 Assoc_List : List_Id);
4287 -- The constraint to a component may be given by a
4288 -- discriminant of the enclosing type, in which case
4289 -- we have to retrieve its value, which is part of the
4290 -- enclosing aggregate. Assoc_List provides the
4291 -- discriminant associations of the current type or
4292 -- of some enclosing record.
4293
4294 procedure Propagate_Discriminants
4295 (Aggr : Node_Id;
4296 Assoc_List : List_Id);
4297 -- Nested components may themselves be discriminated
4298 -- types constrained by outer discriminants, whose
4299 -- values must be captured before the aggregate is
4300 -- expanded into assignments.
4301
4302 -----------------------------
4303 -- Add_Discriminant_Values --
4304 -----------------------------
4305
4306 procedure Add_Discriminant_Values
4307 (New_Aggr : Node_Id;
4308 Assoc_List : List_Id)
4309 is
4310 Assoc : Node_Id;
4311 Discr : Entity_Id;
4312 Discr_Elmt : Elmt_Id;
4313 Discr_Val : Node_Id;
4314 Val : Entity_Id;
4315
4316 begin
4317 Discr := First_Discriminant (Etype (New_Aggr));
4318 Discr_Elmt :=
4319 First_Elmt
4320 (Discriminant_Constraint (Etype (New_Aggr)));
4321 while Present (Discr_Elmt) loop
4322 Discr_Val := Node (Discr_Elmt);
4323
4324 -- If the constraint is given by a discriminant
4325 -- it is a discriminant of an enclosing record,
4326 -- and its value has already been placed in the
4327 -- association list.
4328
4329 if Is_Entity_Name (Discr_Val)
4330 and then
4331 Ekind (Entity (Discr_Val)) = E_Discriminant
4332 then
4333 Val := Entity (Discr_Val);
4334
4335 Assoc := First (Assoc_List);
4336 while Present (Assoc) loop
4337 if Present
4338 (Entity (First (Choices (Assoc))))
4339 and then
4340 Entity (First (Choices (Assoc))) = Val
4341 then
4342 Discr_Val := Expression (Assoc);
4343 exit;
4344 end if;
4345
4346 Next (Assoc);
4347 end loop;
4348 end if;
4349
4350 Add_Association
4351 (Discr, New_Copy_Tree (Discr_Val),
4352 Component_Associations (New_Aggr));
4353
4354 -- If the discriminant constraint is a current
4355 -- instance, mark the current aggregate so that
4356 -- the self-reference can be expanded later.
4357 -- The constraint may refer to the subtype of
4358 -- aggregate, so use base type for comparison.
4359
4360 if Nkind (Discr_Val) = N_Attribute_Reference
4361 and then Is_Entity_Name (Prefix (Discr_Val))
4362 and then Is_Type (Entity (Prefix (Discr_Val)))
4363 and then Base_Type (Etype (N)) =
4364 Entity (Prefix (Discr_Val))
4365 then
4366 Set_Has_Self_Reference (N);
4367 end if;
4368
4369 Next_Elmt (Discr_Elmt);
4370 Next_Discriminant (Discr);
4371 end loop;
4372 end Add_Discriminant_Values;
4373
4374 -----------------------------
4375 -- Propagate_Discriminants --
4376 -----------------------------
4377
4378 procedure Propagate_Discriminants
4379 (Aggr : Node_Id;
4380 Assoc_List : List_Id)
4381 is
4382 Aggr_Type : constant Entity_Id :=
4383 Base_Type (Etype (Aggr));
4384 Def_Node : constant Node_Id :=
4385 Type_Definition
4386 (Declaration_Node (Aggr_Type));
4387
4388 Comp : Node_Id;
4389 Comp_Elmt : Elmt_Id;
4390 Components : constant Elist_Id := New_Elmt_List;
4391 Needs_Box : Boolean := False;
4392 Errors : Boolean;
4393
4394 procedure Process_Component (Comp : Entity_Id);
4395 -- Add one component with a box association to the
4396 -- inner aggregate, and recurse if component is
4397 -- itself composite.
4398
4399 -----------------------
4400 -- Process_Component --
4401 -----------------------
4402
4403 procedure Process_Component (Comp : Entity_Id) is
4404 T : constant Entity_Id := Etype (Comp);
4405 New_Aggr : Node_Id;
4406
4407 begin
4408 if Is_Record_Type (T)
4409 and then Has_Discriminants (T)
4410 then
4411 New_Aggr :=
4412 Make_Aggregate (Loc, New_List, New_List);
4413 Set_Etype (New_Aggr, T);
4414 Add_Association
4415 (Comp, New_Aggr,
4416 Component_Associations (Aggr));
4417
4418 -- Collect discriminant values and recurse
4419
4420 Add_Discriminant_Values
4421 (New_Aggr, Assoc_List);
4422 Propagate_Discriminants
4423 (New_Aggr, Assoc_List);
4424
4425 else
4426 Needs_Box := True;
4427 end if;
4428 end Process_Component;
4429
4430 -- Start of processing for Propagate_Discriminants
4431
4432 begin
4433 -- The component type may be a variant type, so
4434 -- collect the components that are ruled by the
4435 -- known values of the discriminants. Their values
4436 -- have already been inserted into the component
4437 -- list of the current aggregate.
4438
4439 if Nkind (Def_Node) = N_Record_Definition
4440 and then Present (Component_List (Def_Node))
4441 and then
4442 Present
4443 (Variant_Part (Component_List (Def_Node)))
4444 then
4445 Gather_Components (Aggr_Type,
4446 Component_List (Def_Node),
4447 Governed_By => Component_Associations (Aggr),
4448 Into => Components,
4449 Report_Errors => Errors);
4450
4451 Comp_Elmt := First_Elmt (Components);
4452 while Present (Comp_Elmt) loop
4453 if Ekind (Node (Comp_Elmt)) /=
4454 E_Discriminant
4455 then
4456 Process_Component (Node (Comp_Elmt));
4457 end if;
4458
4459 Next_Elmt (Comp_Elmt);
4460 end loop;
4461
4462 -- No variant part, iterate over all components
4463
4464 else
4465 Comp := First_Component (Etype (Aggr));
4466 while Present (Comp) loop
4467 Process_Component (Comp);
4468 Next_Component (Comp);
4469 end loop;
4470 end if;
4471
4472 if Needs_Box then
4473 Append_To (Component_Associations (Aggr),
4474 Make_Component_Association (Loc,
4475 Choices =>
4476 New_List (Make_Others_Choice (Loc)),
4477 Expression => Empty,
4478 Box_Present => True));
4479 end if;
4480 end Propagate_Discriminants;
4481
4482 -- Start of processing for Capture_Discriminants
4483
4484 begin
4485 Expr := Make_Aggregate (Loc, New_List, New_List);
4486 Set_Etype (Expr, Ctyp);
4487
4488 -- If the enclosing type has discriminants, they have
4489 -- been collected in the aggregate earlier, and they
4490 -- may appear as constraints of subcomponents.
4491
4492 -- Similarly if this component has discriminants, they
4493 -- might in turn be propagated to their components.
4494
4495 if Has_Discriminants (Typ) then
4496 Add_Discriminant_Values (Expr, New_Assoc_List);
4497 Propagate_Discriminants (Expr, New_Assoc_List);
4498
4499 elsif Has_Discriminants (Ctyp) then
4500 Add_Discriminant_Values
4501 (Expr, Component_Associations (Expr));
4502 Propagate_Discriminants
4503 (Expr, Component_Associations (Expr));
4504
4505 else
4506 declare
4507 Comp : Entity_Id;
4508
4509 begin
4510 -- If the type has additional components, create
4511 -- an OTHERS box association for them.
4512
4513 Comp := First_Component (Ctyp);
4514 while Present (Comp) loop
4515 if Ekind (Comp) = E_Component then
4516 if not Is_Record_Type (Etype (Comp)) then
4517 Append_To
4518 (Component_Associations (Expr),
4519 Make_Component_Association (Loc,
4520 Choices =>
4521 New_List (
4522 Make_Others_Choice (Loc)),
4523 Expression => Empty,
4524 Box_Present => True));
4525 end if;
4526 exit;
4527 end if;
4528
4529 Next_Component (Comp);
4530 end loop;
4531 end;
4532 end if;
4533
4534 Add_Association
4535 (Component => Component,
4536 Expr => Expr,
4537 Assoc_List => New_Assoc_List);
4538 end Capture_Discriminants;
4539
4540 else
4541 Add_Association
4542 (Component => Component,
4543 Expr => Empty,
4544 Assoc_List => New_Assoc_List,
4545 Is_Box_Present => True);
4546 end if;
4547
4548 -- Otherwise we only need to resolve the expression if the
4549 -- component has partially initialized values (required to
4550 -- expand the corresponding assignments and run-time checks).
4551
4552 elsif Present (Expr)
4553 and then Is_Partially_Initialized_Type (Ctyp)
4554 then
4555 Resolve_Aggr_Expr (Expr, Component);
4556 end if;
4557 end Check_Box_Component;
4558
4559 elsif No (Expr) then
4560
4561 -- Ignore hidden components associated with the position of the
4562 -- interface tags: these are initialized dynamically.
4563
4564 if not Present (Related_Type (Component)) then
4565 Error_Msg_NE
4566 ("no value supplied for component &!", N, Component);
4567 end if;
4568
4569 else
4570 Resolve_Aggr_Expr (Expr, Component);
4571 end if;
4572
4573 Next_Elmt (Component_Elmt);
4574 end loop;
4575
4576 -- STEP 7: check for invalid components + check type in choice list
4577
4578 Step_7 : declare
4579 Selectr : Node_Id;
4580 -- Selector name
4581
4582 Typech : Entity_Id;
4583 -- Type of first component in choice list
4584
4585 begin
4586 if Present (Component_Associations (N)) then
4587 Assoc := First (Component_Associations (N));
4588 else
4589 Assoc := Empty;
4590 end if;
4591
4592 Verification : while Present (Assoc) loop
4593 Selectr := First (Choices (Assoc));
4594 Typech := Empty;
4595
4596 if Nkind (Selectr) = N_Others_Choice then
4597
4598 -- Ada 2005 (AI-287): others choice may have expression or box
4599
4600 if No (Others_Etype) and then Others_Box = 0 then
4601 Error_Msg_N
4602 ("OTHERS must represent at least one component", Selectr);
4603
4604 elsif Others_Box = 1 and then Warn_On_Redundant_Constructs then
4605 Error_Msg_N ("others choice is redundant?", Box_Node);
4606 Error_Msg_N
4607 ("\previous choices cover all components?", Box_Node);
4608 end if;
4609
4610 exit Verification;
4611 end if;
4612
4613 while Present (Selectr) loop
4614 New_Assoc := First (New_Assoc_List);
4615 while Present (New_Assoc) loop
4616 Component := First (Choices (New_Assoc));
4617
4618 if Chars (Selectr) = Chars (Component) then
4619 if Style_Check then
4620 Check_Identifier (Selectr, Entity (Component));
4621 end if;
4622
4623 exit;
4624 end if;
4625
4626 Next (New_Assoc);
4627 end loop;
4628
4629 -- If no association, this is not a legal component of the type
4630 -- in question, unless its association is provided with a box.
4631
4632 if No (New_Assoc) then
4633 if Box_Present (Parent (Selectr)) then
4634
4635 -- This may still be a bogus component with a box. Scan
4636 -- list of components to verify that a component with
4637 -- that name exists.
4638
4639 declare
4640 C : Entity_Id;
4641
4642 begin
4643 C := First_Component (Typ);
4644 while Present (C) loop
4645 if Chars (C) = Chars (Selectr) then
4646
4647 -- If the context is an extension aggregate,
4648 -- the component must not be inherited from
4649 -- the ancestor part of the aggregate.
4650
4651 if Nkind (N) /= N_Extension_Aggregate
4652 or else
4653 Scope (Original_Record_Component (C)) /=
4654 Etype (Ancestor_Part (N))
4655 then
4656 exit;
4657 end if;
4658 end if;
4659
4660 Next_Component (C);
4661 end loop;
4662
4663 if No (C) then
4664 Error_Msg_Node_2 := Typ;
4665 Error_Msg_N ("& is not a component of}", Selectr);
4666 end if;
4667 end;
4668
4669 elsif Chars (Selectr) /= Name_uTag
4670 and then Chars (Selectr) /= Name_uParent
4671 then
4672 if not Has_Discriminants (Typ) then
4673 Error_Msg_Node_2 := Typ;
4674 Error_Msg_N ("& is not a component of}", Selectr);
4675 else
4676 Error_Msg_N
4677 ("& is not a component of the aggregate subtype",
4678 Selectr);
4679 end if;
4680
4681 Check_Misspelled_Component (Components, Selectr);
4682 end if;
4683
4684 elsif No (Typech) then
4685 Typech := Base_Type (Etype (Component));
4686
4687 -- AI05-0199: In Ada 2012, several components of anonymous
4688 -- access types can appear in a choice list, as long as the
4689 -- designated types match.
4690
4691 elsif Typech /= Base_Type (Etype (Component)) then
4692 if Ada_Version >= Ada_2012
4693 and then Ekind (Typech) = E_Anonymous_Access_Type
4694 and then
4695 Ekind (Etype (Component)) = E_Anonymous_Access_Type
4696 and then Base_Type (Designated_Type (Typech)) =
4697 Base_Type (Designated_Type (Etype (Component)))
4698 and then
4699 Subtypes_Statically_Match (Typech, (Etype (Component)))
4700 then
4701 null;
4702
4703 elsif not Box_Present (Parent (Selectr)) then
4704 Error_Msg_N
4705 ("components in choice list must have same type",
4706 Selectr);
4707 end if;
4708 end if;
4709
4710 Next (Selectr);
4711 end loop;
4712
4713 Next (Assoc);
4714 end loop Verification;
4715 end Step_7;
4716
4717 -- STEP 8: replace the original aggregate
4718
4719 Step_8 : declare
4720 New_Aggregate : constant Node_Id := New_Copy (N);
4721
4722 begin
4723 Set_Expressions (New_Aggregate, No_List);
4724 Set_Etype (New_Aggregate, Etype (N));
4725 Set_Component_Associations (New_Aggregate, New_Assoc_List);
4726 Set_Check_Actuals (New_Aggregate, Check_Actuals (N));
4727
4728 Rewrite (N, New_Aggregate);
4729 end Step_8;
4730
4731 -- Check the dimensions of the components in the record aggregate
4732
4733 Analyze_Dimension_Extension_Or_Record_Aggregate (N);
4734 end Resolve_Record_Aggregate;
4735
4736 -----------------------------
4737 -- Check_Can_Never_Be_Null --
4738 -----------------------------
4739
4740 procedure Check_Can_Never_Be_Null (Typ : Entity_Id; Expr : Node_Id) is
4741 Comp_Typ : Entity_Id;
4742
4743 begin
4744 pragma Assert
4745 (Ada_Version >= Ada_2005
4746 and then Present (Expr)
4747 and then Known_Null (Expr));
4748
4749 case Ekind (Typ) is
4750 when E_Array_Type =>
4751 Comp_Typ := Component_Type (Typ);
4752
4753 when E_Component |
4754 E_Discriminant =>
4755 Comp_Typ := Etype (Typ);
4756
4757 when others =>
4758 return;
4759 end case;
4760
4761 if Can_Never_Be_Null (Comp_Typ) then
4762
4763 -- Here we know we have a constraint error. Note that we do not use
4764 -- Apply_Compile_Time_Constraint_Error here to the Expr, which might
4765 -- seem the more natural approach. That's because in some cases the
4766 -- components are rewritten, and the replacement would be missed.
4767 -- We do not mark the whole aggregate as raising a constraint error,
4768 -- because the association may be a null array range.
4769
4770 Error_Msg_N
4771 ("(Ada 2005) null not allowed in null-excluding component??", Expr);
4772 Error_Msg_N
4773 ("\Constraint_Error will be raised at run time??", Expr);
4774
4775 Rewrite (Expr,
4776 Make_Raise_Constraint_Error
4777 (Sloc (Expr), Reason => CE_Access_Check_Failed));
4778 Set_Etype (Expr, Comp_Typ);
4779 Set_Analyzed (Expr);
4780 end if;
4781 end Check_Can_Never_Be_Null;
4782
4783 ---------------------
4784 -- Sort_Case_Table --
4785 ---------------------
4786
4787 procedure Sort_Case_Table (Case_Table : in out Case_Table_Type) is
4788 U : constant Int := Case_Table'Last;
4789 K : Int;
4790 J : Int;
4791 T : Case_Bounds;
4792
4793 begin
4794 K := 1;
4795 while K < U loop
4796 T := Case_Table (K + 1);
4797
4798 J := K + 1;
4799 while J > 1
4800 and then Expr_Value (Case_Table (J - 1).Lo) > Expr_Value (T.Lo)
4801 loop
4802 Case_Table (J) := Case_Table (J - 1);
4803 J := J - 1;
4804 end loop;
4805
4806 Case_Table (J) := T;
4807 K := K + 1;
4808 end loop;
4809 end Sort_Case_Table;
4810
4811 end Sem_Aggr;