File : exp_util.adb
1 ------------------------------------------------------------------------------
2 -- --
3 -- GNAT COMPILER COMPONENTS --
4 -- --
5 -- E X P _ U T I L --
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 Casing; use Casing;
29 with Checks; use Checks;
30 with Debug; use Debug;
31 with Einfo; use Einfo;
32 with Elists; use Elists;
33 with Errout; use Errout;
34 with Exp_Aggr; use Exp_Aggr;
35 with Exp_Ch6; use Exp_Ch6;
36 with Exp_Ch7; use Exp_Ch7;
37 with Ghost; use Ghost;
38 with Inline; use Inline;
39 with Itypes; use Itypes;
40 with Lib; use Lib;
41 with Nlists; use Nlists;
42 with Nmake; use Nmake;
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_Ch8; use Sem_Ch8;
49 with Sem_Ch13; use Sem_Ch13;
50 with Sem_Eval; use Sem_Eval;
51 with Sem_Res; use Sem_Res;
52 with Sem_Type; use Sem_Type;
53 with Sem_Util; use Sem_Util;
54 with Snames; use Snames;
55 with Stand; use Stand;
56 with Stringt; use Stringt;
57 with Targparm; use Targparm;
58 with Tbuild; use Tbuild;
59 with Ttypes; use Ttypes;
60 with Urealp; use Urealp;
61 with Validsw; use Validsw;
62
63 package body Exp_Util is
64
65 -----------------------
66 -- Local Subprograms --
67 -----------------------
68
69 function Build_Task_Array_Image
70 (Loc : Source_Ptr;
71 Id_Ref : Node_Id;
72 A_Type : Entity_Id;
73 Dyn : Boolean := False) return Node_Id;
74 -- Build function to generate the image string for a task that is an array
75 -- component, concatenating the images of each index. To avoid storage
76 -- leaks, the string is built with successive slice assignments. The flag
77 -- Dyn indicates whether this is called for the initialization procedure of
78 -- an array of tasks, or for the name of a dynamically created task that is
79 -- assigned to an indexed component.
80
81 function Build_Task_Image_Function
82 (Loc : Source_Ptr;
83 Decls : List_Id;
84 Stats : List_Id;
85 Res : Entity_Id) return Node_Id;
86 -- Common processing for Task_Array_Image and Task_Record_Image. Build
87 -- function body that computes image.
88
89 procedure Build_Task_Image_Prefix
90 (Loc : Source_Ptr;
91 Len : out Entity_Id;
92 Res : out Entity_Id;
93 Pos : out Entity_Id;
94 Prefix : Entity_Id;
95 Sum : Node_Id;
96 Decls : List_Id;
97 Stats : List_Id);
98 -- Common processing for Task_Array_Image and Task_Record_Image. Create
99 -- local variables and assign prefix of name to result string.
100
101 function Build_Task_Record_Image
102 (Loc : Source_Ptr;
103 Id_Ref : Node_Id;
104 Dyn : Boolean := False) return Node_Id;
105 -- Build function to generate the image string for a task that is a record
106 -- component. Concatenate name of variable with that of selector. The flag
107 -- Dyn indicates whether this is called for the initialization procedure of
108 -- record with task components, or for a dynamically created task that is
109 -- assigned to a selected component.
110
111 procedure Evaluate_Slice_Bounds (Slice : Node_Id);
112 -- Force evaluation of bounds of a slice, which may be given by a range
113 -- or by a subtype indication with or without a constraint.
114
115 function Make_CW_Equivalent_Type
116 (T : Entity_Id;
117 E : Node_Id) return Entity_Id;
118 -- T is a class-wide type entity, E is the initial expression node that
119 -- constrains T in case such as: " X: T := E" or "new T'(E)". This function
120 -- returns the entity of the Equivalent type and inserts on the fly the
121 -- necessary declaration such as:
122 --
123 -- type anon is record
124 -- _parent : Root_Type (T); constrained with E discriminants (if any)
125 -- Extension : String (1 .. expr to match size of E);
126 -- end record;
127 --
128 -- This record is compatible with any object of the class of T thanks to
129 -- the first field and has the same size as E thanks to the second.
130
131 function Make_Literal_Range
132 (Loc : Source_Ptr;
133 Literal_Typ : Entity_Id) return Node_Id;
134 -- Produce a Range node whose bounds are:
135 -- Low_Bound (Literal_Type) ..
136 -- Low_Bound (Literal_Type) + (Length (Literal_Typ) - 1)
137 -- this is used for expanding declarations like X : String := "sdfgdfg";
138 --
139 -- If the index type of the target array is not integer, we generate:
140 -- Low_Bound (Literal_Type) ..
141 -- Literal_Type'Val
142 -- (Literal_Type'Pos (Low_Bound (Literal_Type))
143 -- + (Length (Literal_Typ) -1))
144
145 function Make_Non_Empty_Check
146 (Loc : Source_Ptr;
147 N : Node_Id) return Node_Id;
148 -- Produce a boolean expression checking that the unidimensional array
149 -- node N is not empty.
150
151 function New_Class_Wide_Subtype
152 (CW_Typ : Entity_Id;
153 N : Node_Id) return Entity_Id;
154 -- Create an implicit subtype of CW_Typ attached to node N
155
156 function Requires_Cleanup_Actions
157 (L : List_Id;
158 Lib_Level : Boolean;
159 Nested_Constructs : Boolean) return Boolean;
160 -- Given a list L, determine whether it contains one of the following:
161 --
162 -- 1) controlled objects
163 -- 2) library-level tagged types
164 --
165 -- Lib_Level is True when the list comes from a construct at the library
166 -- level, and False otherwise. Nested_Constructs is True when any nested
167 -- packages declared in L must be processed, and False otherwise.
168
169 -------------------------------------
170 -- Activate_Atomic_Synchronization --
171 -------------------------------------
172
173 procedure Activate_Atomic_Synchronization (N : Node_Id) is
174 Msg_Node : Node_Id;
175
176 begin
177 case Nkind (Parent (N)) is
178
179 -- Check for cases of appearing in the prefix of a construct where
180 -- we don't need atomic synchronization for this kind of usage.
181
182 when
183 -- Nothing to do if we are the prefix of an attribute, since we
184 -- do not want an atomic sync operation for things like 'Size.
185
186 N_Attribute_Reference |
187
188 -- The N_Reference node is like an attribute
189
190 N_Reference |
191
192 -- Nothing to do for a reference to a component (or components)
193 -- of a composite object. Only reads and updates of the object
194 -- as a whole require atomic synchronization (RM C.6 (15)).
195
196 N_Indexed_Component |
197 N_Selected_Component |
198 N_Slice =>
199
200 -- For all the above cases, nothing to do if we are the prefix
201
202 if Prefix (Parent (N)) = N then
203 return;
204 end if;
205
206 when others => null;
207 end case;
208
209 -- Nothing to do for the identifier in an object renaming declaration,
210 -- the renaming itself does not need atomic synchronization.
211
212 if Nkind (Parent (N)) = N_Object_Renaming_Declaration then
213 return;
214 end if;
215
216 -- Go ahead and set the flag
217
218 Set_Atomic_Sync_Required (N);
219
220 -- Generate info message if requested
221
222 if Warn_On_Atomic_Synchronization then
223 case Nkind (N) is
224 when N_Identifier =>
225 Msg_Node := N;
226
227 when N_Selected_Component | N_Expanded_Name =>
228 Msg_Node := Selector_Name (N);
229
230 when N_Explicit_Dereference | N_Indexed_Component =>
231 Msg_Node := Empty;
232
233 when others =>
234 pragma Assert (False);
235 return;
236 end case;
237
238 if Present (Msg_Node) then
239 Error_Msg_N
240 ("info: atomic synchronization set for &?N?", Msg_Node);
241 else
242 Error_Msg_N
243 ("info: atomic synchronization set?N?", N);
244 end if;
245 end if;
246 end Activate_Atomic_Synchronization;
247
248 ----------------------
249 -- Adjust_Condition --
250 ----------------------
251
252 procedure Adjust_Condition (N : Node_Id) is
253 begin
254 if No (N) then
255 return;
256 end if;
257
258 declare
259 Loc : constant Source_Ptr := Sloc (N);
260 T : constant Entity_Id := Etype (N);
261 Ti : Entity_Id;
262
263 begin
264 -- Defend against a call where the argument has no type, or has a
265 -- type that is not Boolean. This can occur because of prior errors.
266
267 if No (T) or else not Is_Boolean_Type (T) then
268 return;
269 end if;
270
271 -- Apply validity checking if needed
272
273 if Validity_Checks_On and Validity_Check_Tests then
274 Ensure_Valid (N);
275 end if;
276
277 -- Immediate return if standard boolean, the most common case,
278 -- where nothing needs to be done.
279
280 if Base_Type (T) = Standard_Boolean then
281 return;
282 end if;
283
284 -- Case of zero/non-zero semantics or non-standard enumeration
285 -- representation. In each case, we rewrite the node as:
286
287 -- ityp!(N) /= False'Enum_Rep
288
289 -- where ityp is an integer type with large enough size to hold any
290 -- value of type T.
291
292 if Nonzero_Is_True (T) or else Has_Non_Standard_Rep (T) then
293 if Esize (T) <= Esize (Standard_Integer) then
294 Ti := Standard_Integer;
295 else
296 Ti := Standard_Long_Long_Integer;
297 end if;
298
299 Rewrite (N,
300 Make_Op_Ne (Loc,
301 Left_Opnd => Unchecked_Convert_To (Ti, N),
302 Right_Opnd =>
303 Make_Attribute_Reference (Loc,
304 Attribute_Name => Name_Enum_Rep,
305 Prefix =>
306 New_Occurrence_Of (First_Literal (T), Loc))));
307 Analyze_And_Resolve (N, Standard_Boolean);
308
309 else
310 Rewrite (N, Convert_To (Standard_Boolean, N));
311 Analyze_And_Resolve (N, Standard_Boolean);
312 end if;
313 end;
314 end Adjust_Condition;
315
316 ------------------------
317 -- Adjust_Result_Type --
318 ------------------------
319
320 procedure Adjust_Result_Type (N : Node_Id; T : Entity_Id) is
321 begin
322 -- Ignore call if current type is not Standard.Boolean
323
324 if Etype (N) /= Standard_Boolean then
325 return;
326 end if;
327
328 -- If result is already of correct type, nothing to do. Note that
329 -- this will get the most common case where everything has a type
330 -- of Standard.Boolean.
331
332 if Base_Type (T) = Standard_Boolean then
333 return;
334
335 else
336 declare
337 KP : constant Node_Kind := Nkind (Parent (N));
338
339 begin
340 -- If result is to be used as a Condition in the syntax, no need
341 -- to convert it back, since if it was changed to Standard.Boolean
342 -- using Adjust_Condition, that is just fine for this usage.
343
344 if KP in N_Raise_xxx_Error or else KP in N_Has_Condition then
345 return;
346
347 -- If result is an operand of another logical operation, no need
348 -- to reset its type, since Standard.Boolean is just fine, and
349 -- such operations always do Adjust_Condition on their operands.
350
351 elsif KP in N_Op_Boolean
352 or else KP in N_Short_Circuit
353 or else KP = N_Op_Not
354 then
355 return;
356
357 -- Otherwise we perform a conversion from the current type, which
358 -- must be Standard.Boolean, to the desired type. Use the base
359 -- type to prevent spurious constraint checks that are extraneous
360 -- to the transformation. The type and its base have the same
361 -- representation, standard or otherwise.
362
363 else
364 Set_Analyzed (N);
365 Rewrite (N, Convert_To (Base_Type (T), N));
366 Analyze_And_Resolve (N, Base_Type (T));
367 end if;
368 end;
369 end if;
370 end Adjust_Result_Type;
371
372 --------------------------
373 -- Append_Freeze_Action --
374 --------------------------
375
376 procedure Append_Freeze_Action (T : Entity_Id; N : Node_Id) is
377 Fnode : Node_Id;
378
379 begin
380 Ensure_Freeze_Node (T);
381 Fnode := Freeze_Node (T);
382
383 if No (Actions (Fnode)) then
384 Set_Actions (Fnode, New_List (N));
385 else
386 Append (N, Actions (Fnode));
387 end if;
388
389 end Append_Freeze_Action;
390
391 ---------------------------
392 -- Append_Freeze_Actions --
393 ---------------------------
394
395 procedure Append_Freeze_Actions (T : Entity_Id; L : List_Id) is
396 Fnode : Node_Id;
397
398 begin
399 if No (L) then
400 return;
401 end if;
402
403 Ensure_Freeze_Node (T);
404 Fnode := Freeze_Node (T);
405
406 if No (Actions (Fnode)) then
407 Set_Actions (Fnode, L);
408 else
409 Append_List (L, Actions (Fnode));
410 end if;
411 end Append_Freeze_Actions;
412
413 ------------------------------------
414 -- Build_Allocate_Deallocate_Proc --
415 ------------------------------------
416
417 procedure Build_Allocate_Deallocate_Proc
418 (N : Node_Id;
419 Is_Allocate : Boolean)
420 is
421 Desig_Typ : Entity_Id;
422 Expr : Node_Id;
423 Pool_Id : Entity_Id;
424 Proc_To_Call : Node_Id := Empty;
425 Ptr_Typ : Entity_Id;
426
427 function Find_Object (E : Node_Id) return Node_Id;
428 -- Given an arbitrary expression of an allocator, try to find an object
429 -- reference in it, otherwise return the original expression.
430
431 function Is_Allocate_Deallocate_Proc (Subp : Entity_Id) return Boolean;
432 -- Determine whether subprogram Subp denotes a custom allocate or
433 -- deallocate.
434
435 -----------------
436 -- Find_Object --
437 -----------------
438
439 function Find_Object (E : Node_Id) return Node_Id is
440 Expr : Node_Id;
441
442 begin
443 pragma Assert (Is_Allocate);
444
445 Expr := E;
446 loop
447 if Nkind (Expr) = N_Explicit_Dereference then
448 Expr := Prefix (Expr);
449
450 elsif Nkind (Expr) = N_Qualified_Expression then
451 Expr := Expression (Expr);
452
453 elsif Nkind (Expr) = N_Unchecked_Type_Conversion then
454
455 -- When interface class-wide types are involved in allocation,
456 -- the expander introduces several levels of address arithmetic
457 -- to perform dispatch table displacement. In this scenario the
458 -- object appears as:
459
460 -- Tag_Ptr (Base_Address (<object>'Address))
461
462 -- Detect this case and utilize the whole expression as the
463 -- "object" since it now points to the proper dispatch table.
464
465 if Is_RTE (Etype (Expr), RE_Tag_Ptr) then
466 exit;
467
468 -- Continue to strip the object
469
470 else
471 Expr := Expression (Expr);
472 end if;
473
474 else
475 exit;
476 end if;
477 end loop;
478
479 return Expr;
480 end Find_Object;
481
482 ---------------------------------
483 -- Is_Allocate_Deallocate_Proc --
484 ---------------------------------
485
486 function Is_Allocate_Deallocate_Proc (Subp : Entity_Id) return Boolean is
487 begin
488 -- Look for a subprogram body with only one statement which is a
489 -- call to Allocate_Any_Controlled / Deallocate_Any_Controlled.
490
491 if Ekind (Subp) = E_Procedure
492 and then Nkind (Parent (Parent (Subp))) = N_Subprogram_Body
493 then
494 declare
495 HSS : constant Node_Id :=
496 Handled_Statement_Sequence (Parent (Parent (Subp)));
497 Proc : Entity_Id;
498
499 begin
500 if Present (Statements (HSS))
501 and then Nkind (First (Statements (HSS))) =
502 N_Procedure_Call_Statement
503 then
504 Proc := Entity (Name (First (Statements (HSS))));
505
506 return
507 Is_RTE (Proc, RE_Allocate_Any_Controlled)
508 or else Is_RTE (Proc, RE_Deallocate_Any_Controlled);
509 end if;
510 end;
511 end if;
512
513 return False;
514 end Is_Allocate_Deallocate_Proc;
515
516 -- Start of processing for Build_Allocate_Deallocate_Proc
517
518 begin
519 -- Obtain the attributes of the allocation / deallocation
520
521 if Nkind (N) = N_Free_Statement then
522 Expr := Expression (N);
523 Ptr_Typ := Base_Type (Etype (Expr));
524 Proc_To_Call := Procedure_To_Call (N);
525
526 else
527 if Nkind (N) = N_Object_Declaration then
528 Expr := Expression (N);
529 else
530 Expr := N;
531 end if;
532
533 -- In certain cases an allocator with a qualified expression may
534 -- be relocated and used as the initialization expression of a
535 -- temporary:
536
537 -- before:
538 -- Obj : Ptr_Typ := new Desig_Typ'(...);
539
540 -- after:
541 -- Tmp : Ptr_Typ := new Desig_Typ'(...);
542 -- Obj : Ptr_Typ := Tmp;
543
544 -- Since the allocator is always marked as analyzed to avoid infinite
545 -- expansion, it will never be processed by this routine given that
546 -- the designated type needs finalization actions. Detect this case
547 -- and complete the expansion of the allocator.
548
549 if Nkind (Expr) = N_Identifier
550 and then Nkind (Parent (Entity (Expr))) = N_Object_Declaration
551 and then Nkind (Expression (Parent (Entity (Expr)))) = N_Allocator
552 then
553 Build_Allocate_Deallocate_Proc (Parent (Entity (Expr)), True);
554 return;
555 end if;
556
557 -- The allocator may have been rewritten into something else in which
558 -- case the expansion performed by this routine does not apply.
559
560 if Nkind (Expr) /= N_Allocator then
561 return;
562 end if;
563
564 Ptr_Typ := Base_Type (Etype (Expr));
565 Proc_To_Call := Procedure_To_Call (Expr);
566 end if;
567
568 Pool_Id := Associated_Storage_Pool (Ptr_Typ);
569 Desig_Typ := Available_View (Designated_Type (Ptr_Typ));
570
571 -- Handle concurrent types
572
573 if Is_Concurrent_Type (Desig_Typ)
574 and then Present (Corresponding_Record_Type (Desig_Typ))
575 then
576 Desig_Typ := Corresponding_Record_Type (Desig_Typ);
577 end if;
578
579 -- Do not process allocations / deallocations without a pool
580
581 if No (Pool_Id) then
582 return;
583
584 -- Do not process allocations on / deallocations from the secondary
585 -- stack.
586
587 elsif Is_RTE (Pool_Id, RE_SS_Pool) then
588 return;
589
590 -- Optimize the case where we are using the default Global_Pool_Object,
591 -- and we don't need the heavy finalization machinery.
592
593 elsif Pool_Id = RTE (RE_Global_Pool_Object)
594 and then not Needs_Finalization (Desig_Typ)
595 then
596 return;
597
598 -- Do not replicate the machinery if the allocator / free has already
599 -- been expanded and has a custom Allocate / Deallocate.
600
601 elsif Present (Proc_To_Call)
602 and then Is_Allocate_Deallocate_Proc (Proc_To_Call)
603 then
604 return;
605 end if;
606
607 if Needs_Finalization (Desig_Typ) then
608
609 -- Certain run-time configurations and targets do not provide support
610 -- for controlled types.
611
612 if Restriction_Active (No_Finalization) then
613 return;
614
615 -- Do nothing if the access type may never allocate / deallocate
616 -- objects.
617
618 elsif No_Pool_Assigned (Ptr_Typ) then
619 return;
620 end if;
621
622 -- The allocation / deallocation of a controlled object must be
623 -- chained on / detached from a finalization master.
624
625 pragma Assert (Present (Finalization_Master (Ptr_Typ)));
626
627 -- The only other kind of allocation / deallocation supported by this
628 -- routine is on / from a subpool.
629
630 elsif Nkind (Expr) = N_Allocator
631 and then No (Subpool_Handle_Name (Expr))
632 then
633 return;
634 end if;
635
636 declare
637 Loc : constant Source_Ptr := Sloc (N);
638 Addr_Id : constant Entity_Id := Make_Temporary (Loc, 'A');
639 Alig_Id : constant Entity_Id := Make_Temporary (Loc, 'L');
640 Proc_Id : constant Entity_Id := Make_Temporary (Loc, 'P');
641 Size_Id : constant Entity_Id := Make_Temporary (Loc, 'S');
642
643 Actuals : List_Id;
644 Fin_Addr_Id : Entity_Id;
645 Fin_Mas_Act : Node_Id;
646 Fin_Mas_Id : Entity_Id;
647 Proc_To_Call : Entity_Id;
648 Subpool : Node_Id := Empty;
649
650 begin
651 -- Step 1: Construct all the actuals for the call to library routine
652 -- Allocate_Any_Controlled / Deallocate_Any_Controlled.
653
654 -- a) Storage pool
655
656 Actuals := New_List (New_Occurrence_Of (Pool_Id, Loc));
657
658 if Is_Allocate then
659
660 -- b) Subpool
661
662 if Nkind (Expr) = N_Allocator then
663 Subpool := Subpool_Handle_Name (Expr);
664 end if;
665
666 -- If a subpool is present it can be an arbitrary name, so make
667 -- the actual by copying the tree.
668
669 if Present (Subpool) then
670 Append_To (Actuals, New_Copy_Tree (Subpool, New_Sloc => Loc));
671 else
672 Append_To (Actuals, Make_Null (Loc));
673 end if;
674
675 -- c) Finalization master
676
677 if Needs_Finalization (Desig_Typ) then
678 Fin_Mas_Id := Finalization_Master (Ptr_Typ);
679 Fin_Mas_Act := New_Occurrence_Of (Fin_Mas_Id, Loc);
680
681 -- Handle the case where the master is actually a pointer to a
682 -- master. This case arises in build-in-place functions.
683
684 if Is_Access_Type (Etype (Fin_Mas_Id)) then
685 Append_To (Actuals, Fin_Mas_Act);
686 else
687 Append_To (Actuals,
688 Make_Attribute_Reference (Loc,
689 Prefix => Fin_Mas_Act,
690 Attribute_Name => Name_Unrestricted_Access));
691 end if;
692 else
693 Append_To (Actuals, Make_Null (Loc));
694 end if;
695
696 -- d) Finalize_Address
697
698 -- Primitive Finalize_Address is never generated in CodePeer mode
699 -- since it contains an Unchecked_Conversion.
700
701 if Needs_Finalization (Desig_Typ) and then not CodePeer_Mode then
702 Fin_Addr_Id := Finalize_Address (Desig_Typ);
703 pragma Assert (Present (Fin_Addr_Id));
704
705 Append_To (Actuals,
706 Make_Attribute_Reference (Loc,
707 Prefix => New_Occurrence_Of (Fin_Addr_Id, Loc),
708 Attribute_Name => Name_Unrestricted_Access));
709 else
710 Append_To (Actuals, Make_Null (Loc));
711 end if;
712 end if;
713
714 -- e) Address
715 -- f) Storage_Size
716 -- g) Alignment
717
718 Append_To (Actuals, New_Occurrence_Of (Addr_Id, Loc));
719 Append_To (Actuals, New_Occurrence_Of (Size_Id, Loc));
720
721 if Is_Allocate or else not Is_Class_Wide_Type (Desig_Typ) then
722 Append_To (Actuals, New_Occurrence_Of (Alig_Id, Loc));
723
724 -- For deallocation of class-wide types we obtain the value of
725 -- alignment from the Type Specific Record of the deallocated object.
726 -- This is needed because the frontend expansion of class-wide types
727 -- into equivalent types confuses the backend.
728
729 else
730 -- Generate:
731 -- Obj.all'Alignment
732
733 -- ... because 'Alignment applied to class-wide types is expanded
734 -- into the code that reads the value of alignment from the TSD
735 -- (see Expand_N_Attribute_Reference)
736
737 Append_To (Actuals,
738 Unchecked_Convert_To (RTE (RE_Storage_Offset),
739 Make_Attribute_Reference (Loc,
740 Prefix =>
741 Make_Explicit_Dereference (Loc, Relocate_Node (Expr)),
742 Attribute_Name => Name_Alignment)));
743 end if;
744
745 -- h) Is_Controlled
746
747 if Needs_Finalization (Desig_Typ) then
748 declare
749 Flag_Id : constant Entity_Id := Make_Temporary (Loc, 'F');
750 Flag_Expr : Node_Id;
751 Param : Node_Id;
752 Temp : Node_Id;
753
754 begin
755 if Is_Allocate then
756 Temp := Find_Object (Expression (Expr));
757 else
758 Temp := Expr;
759 end if;
760
761 -- Processing for allocations where the expression is a subtype
762 -- indication.
763
764 if Is_Allocate
765 and then Is_Entity_Name (Temp)
766 and then Is_Type (Entity (Temp))
767 then
768 Flag_Expr :=
769 New_Occurrence_Of
770 (Boolean_Literals
771 (Needs_Finalization (Entity (Temp))), Loc);
772
773 -- The allocation / deallocation of a class-wide object relies
774 -- on a runtime check to determine whether the object is truly
775 -- controlled or not. Depending on this check, the finalization
776 -- machinery will request or reclaim extra storage reserved for
777 -- a list header.
778
779 elsif Is_Class_Wide_Type (Desig_Typ) then
780
781 -- Detect a special case where interface class-wide types
782 -- are involved as the object appears as:
783
784 -- Tag_Ptr (Base_Address (<object>'Address))
785
786 -- The expression already yields the proper tag, generate:
787
788 -- Temp.all
789
790 if Is_RTE (Etype (Temp), RE_Tag_Ptr) then
791 Param :=
792 Make_Explicit_Dereference (Loc,
793 Prefix => Relocate_Node (Temp));
794
795 -- In the default case, obtain the tag of the object about
796 -- to be allocated / deallocated. Generate:
797
798 -- Temp'Tag
799
800 else
801 Param :=
802 Make_Attribute_Reference (Loc,
803 Prefix => Relocate_Node (Temp),
804 Attribute_Name => Name_Tag);
805 end if;
806
807 -- Generate:
808 -- Needs_Finalization (<Param>)
809
810 Flag_Expr :=
811 Make_Function_Call (Loc,
812 Name =>
813 New_Occurrence_Of (RTE (RE_Needs_Finalization), Loc),
814 Parameter_Associations => New_List (Param));
815
816 -- Processing for generic actuals
817
818 elsif Is_Generic_Actual_Type (Desig_Typ) then
819 Flag_Expr :=
820 New_Occurrence_Of (Boolean_Literals
821 (Needs_Finalization (Base_Type (Desig_Typ))), Loc);
822
823 -- The object does not require any specialized checks, it is
824 -- known to be controlled.
825
826 else
827 Flag_Expr := New_Occurrence_Of (Standard_True, Loc);
828 end if;
829
830 -- Create the temporary which represents the finalization state
831 -- of the expression. Generate:
832 --
833 -- F : constant Boolean := <Flag_Expr>;
834
835 Insert_Action (N,
836 Make_Object_Declaration (Loc,
837 Defining_Identifier => Flag_Id,
838 Constant_Present => True,
839 Object_Definition =>
840 New_Occurrence_Of (Standard_Boolean, Loc),
841 Expression => Flag_Expr));
842
843 Append_To (Actuals, New_Occurrence_Of (Flag_Id, Loc));
844 end;
845
846 -- The object is not controlled
847
848 else
849 Append_To (Actuals, New_Occurrence_Of (Standard_False, Loc));
850 end if;
851
852 -- i) On_Subpool
853
854 if Is_Allocate then
855 Append_To (Actuals,
856 New_Occurrence_Of (Boolean_Literals (Present (Subpool)), Loc));
857 end if;
858
859 -- Step 2: Build a wrapper Allocate / Deallocate which internally
860 -- calls Allocate_Any_Controlled / Deallocate_Any_Controlled.
861
862 -- Select the proper routine to call
863
864 if Is_Allocate then
865 Proc_To_Call := RTE (RE_Allocate_Any_Controlled);
866 else
867 Proc_To_Call := RTE (RE_Deallocate_Any_Controlled);
868 end if;
869
870 -- Create a custom Allocate / Deallocate routine which has identical
871 -- profile to that of System.Storage_Pools.
872
873 Insert_Action (N,
874 Make_Subprogram_Body (Loc,
875 Specification =>
876
877 -- procedure Pnn
878
879 Make_Procedure_Specification (Loc,
880 Defining_Unit_Name => Proc_Id,
881 Parameter_Specifications => New_List (
882
883 -- P : Root_Storage_Pool
884
885 Make_Parameter_Specification (Loc,
886 Defining_Identifier => Make_Temporary (Loc, 'P'),
887 Parameter_Type =>
888 New_Occurrence_Of (RTE (RE_Root_Storage_Pool), Loc)),
889
890 -- A : [out] Address
891
892 Make_Parameter_Specification (Loc,
893 Defining_Identifier => Addr_Id,
894 Out_Present => Is_Allocate,
895 Parameter_Type =>
896 New_Occurrence_Of (RTE (RE_Address), Loc)),
897
898 -- S : Storage_Count
899
900 Make_Parameter_Specification (Loc,
901 Defining_Identifier => Size_Id,
902 Parameter_Type =>
903 New_Occurrence_Of (RTE (RE_Storage_Count), Loc)),
904
905 -- L : Storage_Count
906
907 Make_Parameter_Specification (Loc,
908 Defining_Identifier => Alig_Id,
909 Parameter_Type =>
910 New_Occurrence_Of (RTE (RE_Storage_Count), Loc)))),
911
912 Declarations => No_List,
913
914 Handled_Statement_Sequence =>
915 Make_Handled_Sequence_Of_Statements (Loc,
916 Statements => New_List (
917 Make_Procedure_Call_Statement (Loc,
918 Name => New_Occurrence_Of (Proc_To_Call, Loc),
919 Parameter_Associations => Actuals)))));
920
921 -- The newly generated Allocate / Deallocate becomes the default
922 -- procedure to call when the back end processes the allocation /
923 -- deallocation.
924
925 if Is_Allocate then
926 Set_Procedure_To_Call (Expr, Proc_Id);
927 else
928 Set_Procedure_To_Call (N, Proc_Id);
929 end if;
930 end;
931 end Build_Allocate_Deallocate_Proc;
932
933 --------------------------
934 -- Build_Procedure_Form --
935 --------------------------
936
937 procedure Build_Procedure_Form (N : Node_Id) is
938 Loc : constant Source_Ptr := Sloc (N);
939 Subp : constant Entity_Id := Defining_Entity (N);
940
941 Func_Formal : Entity_Id;
942 Proc_Formals : List_Id;
943 Proc_Decl : Node_Id;
944
945 begin
946 -- No action needed if this transformation was already done, or in case
947 -- of subprogram renaming declarations.
948
949 if Nkind (Specification (N)) = N_Procedure_Specification
950 or else Nkind (N) = N_Subprogram_Renaming_Declaration
951 then
952 return;
953 end if;
954
955 -- Ditto when dealing with an expression function, where both the
956 -- original expression and the generated declaration end up being
957 -- expanded here.
958
959 if Rewritten_For_C (Subp) then
960 return;
961 end if;
962
963 Proc_Formals := New_List;
964
965 -- Create a list of formal parameters with the same types as the
966 -- function.
967
968 Func_Formal := First_Formal (Subp);
969 while Present (Func_Formal) loop
970 Append_To (Proc_Formals,
971 Make_Parameter_Specification (Loc,
972 Defining_Identifier =>
973 Make_Defining_Identifier (Loc, Chars (Func_Formal)),
974 Parameter_Type =>
975 New_Occurrence_Of (Etype (Func_Formal), Loc)));
976
977 Next_Formal (Func_Formal);
978 end loop;
979
980 -- Add an extra out parameter to carry the function result
981
982 Name_Len := 6;
983 Name_Buffer (1 .. Name_Len) := "RESULT";
984 Append_To (Proc_Formals,
985 Make_Parameter_Specification (Loc,
986 Defining_Identifier =>
987 Make_Defining_Identifier (Loc, Chars => Name_Find),
988 Out_Present => True,
989 Parameter_Type => New_Occurrence_Of (Etype (Subp), Loc)));
990
991 -- The new procedure declaration is inserted immediately after the
992 -- function declaration. The processing in Build_Procedure_Body_Form
993 -- relies on this order.
994
995 Proc_Decl :=
996 Make_Subprogram_Declaration (Loc,
997 Specification =>
998 Make_Procedure_Specification (Loc,
999 Defining_Unit_Name =>
1000 Make_Defining_Identifier (Loc, Chars (Subp)),
1001 Parameter_Specifications => Proc_Formals));
1002
1003 Insert_After_And_Analyze (Unit_Declaration_Node (Subp), Proc_Decl);
1004
1005 -- Entity of procedure must remain invisible so that it does not
1006 -- overload subsequent references to the original function.
1007
1008 Set_Is_Immediately_Visible (Defining_Entity (Proc_Decl), False);
1009
1010 -- Mark the function as having a procedure form and link the function
1011 -- and its internally built procedure.
1012
1013 Set_Rewritten_For_C (Subp);
1014 Set_Corresponding_Procedure (Subp, Defining_Entity (Proc_Decl));
1015 Set_Corresponding_Function (Defining_Entity (Proc_Decl), Subp);
1016 end Build_Procedure_Form;
1017
1018 ------------------------
1019 -- Build_Runtime_Call --
1020 ------------------------
1021
1022 function Build_Runtime_Call (Loc : Source_Ptr; RE : RE_Id) return Node_Id is
1023 begin
1024 -- If entity is not available, we can skip making the call (this avoids
1025 -- junk duplicated error messages in a number of cases).
1026
1027 if not RTE_Available (RE) then
1028 return Make_Null_Statement (Loc);
1029 else
1030 return
1031 Make_Procedure_Call_Statement (Loc,
1032 Name => New_Occurrence_Of (RTE (RE), Loc));
1033 end if;
1034 end Build_Runtime_Call;
1035
1036 ------------------------
1037 -- Build_SS_Mark_Call --
1038 ------------------------
1039
1040 function Build_SS_Mark_Call
1041 (Loc : Source_Ptr;
1042 Mark : Entity_Id) return Node_Id
1043 is
1044 begin
1045 -- Generate:
1046 -- Mark : constant Mark_Id := SS_Mark;
1047
1048 return
1049 Make_Object_Declaration (Loc,
1050 Defining_Identifier => Mark,
1051 Constant_Present => True,
1052 Object_Definition =>
1053 New_Occurrence_Of (RTE (RE_Mark_Id), Loc),
1054 Expression =>
1055 Make_Function_Call (Loc,
1056 Name => New_Occurrence_Of (RTE (RE_SS_Mark), Loc)));
1057 end Build_SS_Mark_Call;
1058
1059 ---------------------------
1060 -- Build_SS_Release_Call --
1061 ---------------------------
1062
1063 function Build_SS_Release_Call
1064 (Loc : Source_Ptr;
1065 Mark : Entity_Id) return Node_Id
1066 is
1067 begin
1068 -- Generate:
1069 -- SS_Release (Mark);
1070
1071 return
1072 Make_Procedure_Call_Statement (Loc,
1073 Name =>
1074 New_Occurrence_Of (RTE (RE_SS_Release), Loc),
1075 Parameter_Associations => New_List (
1076 New_Occurrence_Of (Mark, Loc)));
1077 end Build_SS_Release_Call;
1078
1079 ----------------------------
1080 -- Build_Task_Array_Image --
1081 ----------------------------
1082
1083 -- This function generates the body for a function that constructs the
1084 -- image string for a task that is an array component. The function is
1085 -- local to the init proc for the array type, and is called for each one
1086 -- of the components. The constructed image has the form of an indexed
1087 -- component, whose prefix is the outer variable of the array type.
1088 -- The n-dimensional array type has known indexes Index, Index2...
1089
1090 -- Id_Ref is an indexed component form created by the enclosing init proc.
1091 -- Its successive indexes are Val1, Val2, ... which are the loop variables
1092 -- in the loops that call the individual task init proc on each component.
1093
1094 -- The generated function has the following structure:
1095
1096 -- function F return String is
1097 -- Pref : string renames Task_Name;
1098 -- T1 : String := Index1'Image (Val1);
1099 -- ...
1100 -- Tn : String := indexn'image (Valn);
1101 -- Len : Integer := T1'Length + ... + Tn'Length + n + 1;
1102 -- -- Len includes commas and the end parentheses.
1103 -- Res : String (1..Len);
1104 -- Pos : Integer := Pref'Length;
1105 --
1106 -- begin
1107 -- Res (1 .. Pos) := Pref;
1108 -- Pos := Pos + 1;
1109 -- Res (Pos) := '(';
1110 -- Pos := Pos + 1;
1111 -- Res (Pos .. Pos + T1'Length - 1) := T1;
1112 -- Pos := Pos + T1'Length;
1113 -- Res (Pos) := '.';
1114 -- Pos := Pos + 1;
1115 -- ...
1116 -- Res (Pos .. Pos + Tn'Length - 1) := Tn;
1117 -- Res (Len) := ')';
1118 --
1119 -- return Res;
1120 -- end F;
1121 --
1122 -- Needless to say, multidimensional arrays of tasks are rare enough that
1123 -- the bulkiness of this code is not really a concern.
1124
1125 function Build_Task_Array_Image
1126 (Loc : Source_Ptr;
1127 Id_Ref : Node_Id;
1128 A_Type : Entity_Id;
1129 Dyn : Boolean := False) return Node_Id
1130 is
1131 Dims : constant Nat := Number_Dimensions (A_Type);
1132 -- Number of dimensions for array of tasks
1133
1134 Temps : array (1 .. Dims) of Entity_Id;
1135 -- Array of temporaries to hold string for each index
1136
1137 Indx : Node_Id;
1138 -- Index expression
1139
1140 Len : Entity_Id;
1141 -- Total length of generated name
1142
1143 Pos : Entity_Id;
1144 -- Running index for substring assignments
1145
1146 Pref : constant Entity_Id := Make_Temporary (Loc, 'P');
1147 -- Name of enclosing variable, prefix of resulting name
1148
1149 Res : Entity_Id;
1150 -- String to hold result
1151
1152 Val : Node_Id;
1153 -- Value of successive indexes
1154
1155 Sum : Node_Id;
1156 -- Expression to compute total size of string
1157
1158 T : Entity_Id;
1159 -- Entity for name at one index position
1160
1161 Decls : constant List_Id := New_List;
1162 Stats : constant List_Id := New_List;
1163
1164 begin
1165 -- For a dynamic task, the name comes from the target variable. For a
1166 -- static one it is a formal of the enclosing init proc.
1167
1168 if Dyn then
1169 Get_Name_String (Chars (Entity (Prefix (Id_Ref))));
1170 Append_To (Decls,
1171 Make_Object_Declaration (Loc,
1172 Defining_Identifier => Pref,
1173 Object_Definition => New_Occurrence_Of (Standard_String, Loc),
1174 Expression =>
1175 Make_String_Literal (Loc,
1176 Strval => String_From_Name_Buffer)));
1177
1178 else
1179 Append_To (Decls,
1180 Make_Object_Renaming_Declaration (Loc,
1181 Defining_Identifier => Pref,
1182 Subtype_Mark => New_Occurrence_Of (Standard_String, Loc),
1183 Name => Make_Identifier (Loc, Name_uTask_Name)));
1184 end if;
1185
1186 Indx := First_Index (A_Type);
1187 Val := First (Expressions (Id_Ref));
1188
1189 for J in 1 .. Dims loop
1190 T := Make_Temporary (Loc, 'T');
1191 Temps (J) := T;
1192
1193 Append_To (Decls,
1194 Make_Object_Declaration (Loc,
1195 Defining_Identifier => T,
1196 Object_Definition => New_Occurrence_Of (Standard_String, Loc),
1197 Expression =>
1198 Make_Attribute_Reference (Loc,
1199 Attribute_Name => Name_Image,
1200 Prefix => New_Occurrence_Of (Etype (Indx), Loc),
1201 Expressions => New_List (New_Copy_Tree (Val)))));
1202
1203 Next_Index (Indx);
1204 Next (Val);
1205 end loop;
1206
1207 Sum := Make_Integer_Literal (Loc, Dims + 1);
1208
1209 Sum :=
1210 Make_Op_Add (Loc,
1211 Left_Opnd => Sum,
1212 Right_Opnd =>
1213 Make_Attribute_Reference (Loc,
1214 Attribute_Name => Name_Length,
1215 Prefix => New_Occurrence_Of (Pref, Loc),
1216 Expressions => New_List (Make_Integer_Literal (Loc, 1))));
1217
1218 for J in 1 .. Dims loop
1219 Sum :=
1220 Make_Op_Add (Loc,
1221 Left_Opnd => Sum,
1222 Right_Opnd =>
1223 Make_Attribute_Reference (Loc,
1224 Attribute_Name => Name_Length,
1225 Prefix =>
1226 New_Occurrence_Of (Temps (J), Loc),
1227 Expressions => New_List (Make_Integer_Literal (Loc, 1))));
1228 end loop;
1229
1230 Build_Task_Image_Prefix (Loc, Len, Res, Pos, Pref, Sum, Decls, Stats);
1231
1232 Set_Character_Literal_Name (Char_Code (Character'Pos ('(')));
1233
1234 Append_To (Stats,
1235 Make_Assignment_Statement (Loc,
1236 Name =>
1237 Make_Indexed_Component (Loc,
1238 Prefix => New_Occurrence_Of (Res, Loc),
1239 Expressions => New_List (New_Occurrence_Of (Pos, Loc))),
1240 Expression =>
1241 Make_Character_Literal (Loc,
1242 Chars => Name_Find,
1243 Char_Literal_Value => UI_From_Int (Character'Pos ('(')))));
1244
1245 Append_To (Stats,
1246 Make_Assignment_Statement (Loc,
1247 Name => New_Occurrence_Of (Pos, Loc),
1248 Expression =>
1249 Make_Op_Add (Loc,
1250 Left_Opnd => New_Occurrence_Of (Pos, Loc),
1251 Right_Opnd => Make_Integer_Literal (Loc, 1))));
1252
1253 for J in 1 .. Dims loop
1254
1255 Append_To (Stats,
1256 Make_Assignment_Statement (Loc,
1257 Name =>
1258 Make_Slice (Loc,
1259 Prefix => New_Occurrence_Of (Res, Loc),
1260 Discrete_Range =>
1261 Make_Range (Loc,
1262 Low_Bound => New_Occurrence_Of (Pos, Loc),
1263 High_Bound =>
1264 Make_Op_Subtract (Loc,
1265 Left_Opnd =>
1266 Make_Op_Add (Loc,
1267 Left_Opnd => New_Occurrence_Of (Pos, Loc),
1268 Right_Opnd =>
1269 Make_Attribute_Reference (Loc,
1270 Attribute_Name => Name_Length,
1271 Prefix =>
1272 New_Occurrence_Of (Temps (J), Loc),
1273 Expressions =>
1274 New_List (Make_Integer_Literal (Loc, 1)))),
1275 Right_Opnd => Make_Integer_Literal (Loc, 1)))),
1276
1277 Expression => New_Occurrence_Of (Temps (J), Loc)));
1278
1279 if J < Dims then
1280 Append_To (Stats,
1281 Make_Assignment_Statement (Loc,
1282 Name => New_Occurrence_Of (Pos, Loc),
1283 Expression =>
1284 Make_Op_Add (Loc,
1285 Left_Opnd => New_Occurrence_Of (Pos, Loc),
1286 Right_Opnd =>
1287 Make_Attribute_Reference (Loc,
1288 Attribute_Name => Name_Length,
1289 Prefix => New_Occurrence_Of (Temps (J), Loc),
1290 Expressions =>
1291 New_List (Make_Integer_Literal (Loc, 1))))));
1292
1293 Set_Character_Literal_Name (Char_Code (Character'Pos (',')));
1294
1295 Append_To (Stats,
1296 Make_Assignment_Statement (Loc,
1297 Name => Make_Indexed_Component (Loc,
1298 Prefix => New_Occurrence_Of (Res, Loc),
1299 Expressions => New_List (New_Occurrence_Of (Pos, Loc))),
1300 Expression =>
1301 Make_Character_Literal (Loc,
1302 Chars => Name_Find,
1303 Char_Literal_Value => UI_From_Int (Character'Pos (',')))));
1304
1305 Append_To (Stats,
1306 Make_Assignment_Statement (Loc,
1307 Name => New_Occurrence_Of (Pos, Loc),
1308 Expression =>
1309 Make_Op_Add (Loc,
1310 Left_Opnd => New_Occurrence_Of (Pos, Loc),
1311 Right_Opnd => Make_Integer_Literal (Loc, 1))));
1312 end if;
1313 end loop;
1314
1315 Set_Character_Literal_Name (Char_Code (Character'Pos (')')));
1316
1317 Append_To (Stats,
1318 Make_Assignment_Statement (Loc,
1319 Name =>
1320 Make_Indexed_Component (Loc,
1321 Prefix => New_Occurrence_Of (Res, Loc),
1322 Expressions => New_List (New_Occurrence_Of (Len, Loc))),
1323 Expression =>
1324 Make_Character_Literal (Loc,
1325 Chars => Name_Find,
1326 Char_Literal_Value => UI_From_Int (Character'Pos (')')))));
1327 return Build_Task_Image_Function (Loc, Decls, Stats, Res);
1328 end Build_Task_Array_Image;
1329
1330 ----------------------------
1331 -- Build_Task_Image_Decls --
1332 ----------------------------
1333
1334 function Build_Task_Image_Decls
1335 (Loc : Source_Ptr;
1336 Id_Ref : Node_Id;
1337 A_Type : Entity_Id;
1338 In_Init_Proc : Boolean := False) return List_Id
1339 is
1340 Decls : constant List_Id := New_List;
1341 T_Id : Entity_Id := Empty;
1342 Decl : Node_Id;
1343 Expr : Node_Id := Empty;
1344 Fun : Node_Id := Empty;
1345 Is_Dyn : constant Boolean :=
1346 Nkind (Parent (Id_Ref)) = N_Assignment_Statement
1347 and then
1348 Nkind (Expression (Parent (Id_Ref))) = N_Allocator;
1349
1350 begin
1351 -- If Discard_Names or No_Implicit_Heap_Allocations are in effect,
1352 -- generate a dummy declaration only.
1353
1354 if Restriction_Active (No_Implicit_Heap_Allocations)
1355 or else Global_Discard_Names
1356 then
1357 T_Id := Make_Temporary (Loc, 'J');
1358 Name_Len := 0;
1359
1360 return
1361 New_List (
1362 Make_Object_Declaration (Loc,
1363 Defining_Identifier => T_Id,
1364 Object_Definition => New_Occurrence_Of (Standard_String, Loc),
1365 Expression =>
1366 Make_String_Literal (Loc,
1367 Strval => String_From_Name_Buffer)));
1368
1369 else
1370 if Nkind (Id_Ref) = N_Identifier
1371 or else Nkind (Id_Ref) = N_Defining_Identifier
1372 then
1373 -- For a simple variable, the image of the task is built from
1374 -- the name of the variable. To avoid possible conflict with the
1375 -- anonymous type created for a single protected object, add a
1376 -- numeric suffix.
1377
1378 T_Id :=
1379 Make_Defining_Identifier (Loc,
1380 New_External_Name (Chars (Id_Ref), 'T', 1));
1381
1382 Get_Name_String (Chars (Id_Ref));
1383
1384 Expr :=
1385 Make_String_Literal (Loc,
1386 Strval => String_From_Name_Buffer);
1387
1388 elsif Nkind (Id_Ref) = N_Selected_Component then
1389 T_Id :=
1390 Make_Defining_Identifier (Loc,
1391 New_External_Name (Chars (Selector_Name (Id_Ref)), 'T'));
1392 Fun := Build_Task_Record_Image (Loc, Id_Ref, Is_Dyn);
1393
1394 elsif Nkind (Id_Ref) = N_Indexed_Component then
1395 T_Id :=
1396 Make_Defining_Identifier (Loc,
1397 New_External_Name (Chars (A_Type), 'N'));
1398
1399 Fun := Build_Task_Array_Image (Loc, Id_Ref, A_Type, Is_Dyn);
1400 end if;
1401 end if;
1402
1403 if Present (Fun) then
1404 Append (Fun, Decls);
1405 Expr := Make_Function_Call (Loc,
1406 Name => New_Occurrence_Of (Defining_Entity (Fun), Loc));
1407
1408 if not In_Init_Proc then
1409 Set_Uses_Sec_Stack (Defining_Entity (Fun));
1410 end if;
1411 end if;
1412
1413 Decl := Make_Object_Declaration (Loc,
1414 Defining_Identifier => T_Id,
1415 Object_Definition => New_Occurrence_Of (Standard_String, Loc),
1416 Constant_Present => True,
1417 Expression => Expr);
1418
1419 Append (Decl, Decls);
1420 return Decls;
1421 end Build_Task_Image_Decls;
1422
1423 -------------------------------
1424 -- Build_Task_Image_Function --
1425 -------------------------------
1426
1427 function Build_Task_Image_Function
1428 (Loc : Source_Ptr;
1429 Decls : List_Id;
1430 Stats : List_Id;
1431 Res : Entity_Id) return Node_Id
1432 is
1433 Spec : Node_Id;
1434
1435 begin
1436 Append_To (Stats,
1437 Make_Simple_Return_Statement (Loc,
1438 Expression => New_Occurrence_Of (Res, Loc)));
1439
1440 Spec := Make_Function_Specification (Loc,
1441 Defining_Unit_Name => Make_Temporary (Loc, 'F'),
1442 Result_Definition => New_Occurrence_Of (Standard_String, Loc));
1443
1444 -- Calls to 'Image use the secondary stack, which must be cleaned up
1445 -- after the task name is built.
1446
1447 return Make_Subprogram_Body (Loc,
1448 Specification => Spec,
1449 Declarations => Decls,
1450 Handled_Statement_Sequence =>
1451 Make_Handled_Sequence_Of_Statements (Loc, Statements => Stats));
1452 end Build_Task_Image_Function;
1453
1454 -----------------------------
1455 -- Build_Task_Image_Prefix --
1456 -----------------------------
1457
1458 procedure Build_Task_Image_Prefix
1459 (Loc : Source_Ptr;
1460 Len : out Entity_Id;
1461 Res : out Entity_Id;
1462 Pos : out Entity_Id;
1463 Prefix : Entity_Id;
1464 Sum : Node_Id;
1465 Decls : List_Id;
1466 Stats : List_Id)
1467 is
1468 begin
1469 Len := Make_Temporary (Loc, 'L', Sum);
1470
1471 Append_To (Decls,
1472 Make_Object_Declaration (Loc,
1473 Defining_Identifier => Len,
1474 Object_Definition => New_Occurrence_Of (Standard_Integer, Loc),
1475 Expression => Sum));
1476
1477 Res := Make_Temporary (Loc, 'R');
1478
1479 Append_To (Decls,
1480 Make_Object_Declaration (Loc,
1481 Defining_Identifier => Res,
1482 Object_Definition =>
1483 Make_Subtype_Indication (Loc,
1484 Subtype_Mark => New_Occurrence_Of (Standard_String, Loc),
1485 Constraint =>
1486 Make_Index_Or_Discriminant_Constraint (Loc,
1487 Constraints =>
1488 New_List (
1489 Make_Range (Loc,
1490 Low_Bound => Make_Integer_Literal (Loc, 1),
1491 High_Bound => New_Occurrence_Of (Len, Loc)))))));
1492
1493 -- Indicate that the result is an internal temporary, so it does not
1494 -- receive a bogus initialization when declaration is expanded. This
1495 -- is both efficient, and prevents anomalies in the handling of
1496 -- dynamic objects on the secondary stack.
1497
1498 Set_Is_Internal (Res);
1499 Pos := Make_Temporary (Loc, 'P');
1500
1501 Append_To (Decls,
1502 Make_Object_Declaration (Loc,
1503 Defining_Identifier => Pos,
1504 Object_Definition => New_Occurrence_Of (Standard_Integer, Loc)));
1505
1506 -- Pos := Prefix'Length;
1507
1508 Append_To (Stats,
1509 Make_Assignment_Statement (Loc,
1510 Name => New_Occurrence_Of (Pos, Loc),
1511 Expression =>
1512 Make_Attribute_Reference (Loc,
1513 Attribute_Name => Name_Length,
1514 Prefix => New_Occurrence_Of (Prefix, Loc),
1515 Expressions => New_List (Make_Integer_Literal (Loc, 1)))));
1516
1517 -- Res (1 .. Pos) := Prefix;
1518
1519 Append_To (Stats,
1520 Make_Assignment_Statement (Loc,
1521 Name =>
1522 Make_Slice (Loc,
1523 Prefix => New_Occurrence_Of (Res, Loc),
1524 Discrete_Range =>
1525 Make_Range (Loc,
1526 Low_Bound => Make_Integer_Literal (Loc, 1),
1527 High_Bound => New_Occurrence_Of (Pos, Loc))),
1528
1529 Expression => New_Occurrence_Of (Prefix, Loc)));
1530
1531 Append_To (Stats,
1532 Make_Assignment_Statement (Loc,
1533 Name => New_Occurrence_Of (Pos, Loc),
1534 Expression =>
1535 Make_Op_Add (Loc,
1536 Left_Opnd => New_Occurrence_Of (Pos, Loc),
1537 Right_Opnd => Make_Integer_Literal (Loc, 1))));
1538 end Build_Task_Image_Prefix;
1539
1540 -----------------------------
1541 -- Build_Task_Record_Image --
1542 -----------------------------
1543
1544 function Build_Task_Record_Image
1545 (Loc : Source_Ptr;
1546 Id_Ref : Node_Id;
1547 Dyn : Boolean := False) return Node_Id
1548 is
1549 Len : Entity_Id;
1550 -- Total length of generated name
1551
1552 Pos : Entity_Id;
1553 -- Index into result
1554
1555 Res : Entity_Id;
1556 -- String to hold result
1557
1558 Pref : constant Entity_Id := Make_Temporary (Loc, 'P');
1559 -- Name of enclosing variable, prefix of resulting name
1560
1561 Sum : Node_Id;
1562 -- Expression to compute total size of string
1563
1564 Sel : Entity_Id;
1565 -- Entity for selector name
1566
1567 Decls : constant List_Id := New_List;
1568 Stats : constant List_Id := New_List;
1569
1570 begin
1571 -- For a dynamic task, the name comes from the target variable. For a
1572 -- static one it is a formal of the enclosing init proc.
1573
1574 if Dyn then
1575 Get_Name_String (Chars (Entity (Prefix (Id_Ref))));
1576 Append_To (Decls,
1577 Make_Object_Declaration (Loc,
1578 Defining_Identifier => Pref,
1579 Object_Definition => New_Occurrence_Of (Standard_String, Loc),
1580 Expression =>
1581 Make_String_Literal (Loc,
1582 Strval => String_From_Name_Buffer)));
1583
1584 else
1585 Append_To (Decls,
1586 Make_Object_Renaming_Declaration (Loc,
1587 Defining_Identifier => Pref,
1588 Subtype_Mark => New_Occurrence_Of (Standard_String, Loc),
1589 Name => Make_Identifier (Loc, Name_uTask_Name)));
1590 end if;
1591
1592 Sel := Make_Temporary (Loc, 'S');
1593
1594 Get_Name_String (Chars (Selector_Name (Id_Ref)));
1595
1596 Append_To (Decls,
1597 Make_Object_Declaration (Loc,
1598 Defining_Identifier => Sel,
1599 Object_Definition => New_Occurrence_Of (Standard_String, Loc),
1600 Expression =>
1601 Make_String_Literal (Loc,
1602 Strval => String_From_Name_Buffer)));
1603
1604 Sum := Make_Integer_Literal (Loc, Nat (Name_Len + 1));
1605
1606 Sum :=
1607 Make_Op_Add (Loc,
1608 Left_Opnd => Sum,
1609 Right_Opnd =>
1610 Make_Attribute_Reference (Loc,
1611 Attribute_Name => Name_Length,
1612 Prefix =>
1613 New_Occurrence_Of (Pref, Loc),
1614 Expressions => New_List (Make_Integer_Literal (Loc, 1))));
1615
1616 Build_Task_Image_Prefix (Loc, Len, Res, Pos, Pref, Sum, Decls, Stats);
1617
1618 Set_Character_Literal_Name (Char_Code (Character'Pos ('.')));
1619
1620 -- Res (Pos) := '.';
1621
1622 Append_To (Stats,
1623 Make_Assignment_Statement (Loc,
1624 Name => Make_Indexed_Component (Loc,
1625 Prefix => New_Occurrence_Of (Res, Loc),
1626 Expressions => New_List (New_Occurrence_Of (Pos, Loc))),
1627 Expression =>
1628 Make_Character_Literal (Loc,
1629 Chars => Name_Find,
1630 Char_Literal_Value =>
1631 UI_From_Int (Character'Pos ('.')))));
1632
1633 Append_To (Stats,
1634 Make_Assignment_Statement (Loc,
1635 Name => New_Occurrence_Of (Pos, Loc),
1636 Expression =>
1637 Make_Op_Add (Loc,
1638 Left_Opnd => New_Occurrence_Of (Pos, Loc),
1639 Right_Opnd => Make_Integer_Literal (Loc, 1))));
1640
1641 -- Res (Pos .. Len) := Selector;
1642
1643 Append_To (Stats,
1644 Make_Assignment_Statement (Loc,
1645 Name => Make_Slice (Loc,
1646 Prefix => New_Occurrence_Of (Res, Loc),
1647 Discrete_Range =>
1648 Make_Range (Loc,
1649 Low_Bound => New_Occurrence_Of (Pos, Loc),
1650 High_Bound => New_Occurrence_Of (Len, Loc))),
1651 Expression => New_Occurrence_Of (Sel, Loc)));
1652
1653 return Build_Task_Image_Function (Loc, Decls, Stats, Res);
1654 end Build_Task_Record_Image;
1655
1656 -----------------------------
1657 -- Check_Float_Op_Overflow --
1658 -----------------------------
1659
1660 procedure Check_Float_Op_Overflow (N : Node_Id) is
1661 begin
1662 -- Return if no check needed
1663
1664 if not Is_Floating_Point_Type (Etype (N))
1665 or else not (Do_Overflow_Check (N) and then Check_Float_Overflow)
1666
1667 -- In CodePeer_Mode, rely on the overflow check flag being set instead
1668 -- and do not expand the code for float overflow checking.
1669
1670 or else CodePeer_Mode
1671 then
1672 return;
1673 end if;
1674
1675 -- Otherwise we replace the expression by
1676
1677 -- do Tnn : constant ftype := expression;
1678 -- constraint_error when not Tnn'Valid;
1679 -- in Tnn;
1680
1681 declare
1682 Loc : constant Source_Ptr := Sloc (N);
1683 Tnn : constant Entity_Id := Make_Temporary (Loc, 'T', N);
1684 Typ : constant Entity_Id := Etype (N);
1685
1686 begin
1687 -- Turn off the Do_Overflow_Check flag, since we are doing that work
1688 -- right here. We also set the node as analyzed to prevent infinite
1689 -- recursion from repeating the operation in the expansion.
1690
1691 Set_Do_Overflow_Check (N, False);
1692 Set_Analyzed (N, True);
1693
1694 -- Do the rewrite to include the check
1695
1696 Rewrite (N,
1697 Make_Expression_With_Actions (Loc,
1698 Actions => New_List (
1699 Make_Object_Declaration (Loc,
1700 Defining_Identifier => Tnn,
1701 Object_Definition => New_Occurrence_Of (Typ, Loc),
1702 Constant_Present => True,
1703 Expression => Relocate_Node (N)),
1704 Make_Raise_Constraint_Error (Loc,
1705 Condition =>
1706 Make_Op_Not (Loc,
1707 Right_Opnd =>
1708 Make_Attribute_Reference (Loc,
1709 Prefix => New_Occurrence_Of (Tnn, Loc),
1710 Attribute_Name => Name_Valid)),
1711 Reason => CE_Overflow_Check_Failed)),
1712 Expression => New_Occurrence_Of (Tnn, Loc)));
1713
1714 Analyze_And_Resolve (N, Typ);
1715 end;
1716 end Check_Float_Op_Overflow;
1717
1718 ----------------------------------
1719 -- Component_May_Be_Bit_Aligned --
1720 ----------------------------------
1721
1722 function Component_May_Be_Bit_Aligned (Comp : Entity_Id) return Boolean is
1723 UT : Entity_Id;
1724
1725 begin
1726 -- If no component clause, then everything is fine, since the back end
1727 -- never bit-misaligns by default, even if there is a pragma Packed for
1728 -- the record.
1729
1730 if No (Comp) or else No (Component_Clause (Comp)) then
1731 return False;
1732 end if;
1733
1734 UT := Underlying_Type (Etype (Comp));
1735
1736 -- It is only array and record types that cause trouble
1737
1738 if not Is_Record_Type (UT) and then not Is_Array_Type (UT) then
1739 return False;
1740
1741 -- If we know that we have a small (64 bits or less) record or small
1742 -- bit-packed array, then everything is fine, since the back end can
1743 -- handle these cases correctly.
1744
1745 elsif Esize (Comp) <= 64
1746 and then (Is_Record_Type (UT) or else Is_Bit_Packed_Array (UT))
1747 then
1748 return False;
1749
1750 -- Otherwise if the component is not byte aligned, we know we have the
1751 -- nasty unaligned case.
1752
1753 elsif Normalized_First_Bit (Comp) /= Uint_0
1754 or else Esize (Comp) mod System_Storage_Unit /= Uint_0
1755 then
1756 return True;
1757
1758 -- If we are large and byte aligned, then OK at this level
1759
1760 else
1761 return False;
1762 end if;
1763 end Component_May_Be_Bit_Aligned;
1764
1765 ----------------------------------------
1766 -- Containing_Package_With_Ext_Axioms --
1767 ----------------------------------------
1768
1769 function Containing_Package_With_Ext_Axioms
1770 (E : Entity_Id) return Entity_Id
1771 is
1772 begin
1773 -- E is the package or generic package which is externally axiomatized
1774
1775 if Ekind_In (E, E_Generic_Package, E_Package)
1776 and then Has_Annotate_Pragma_For_External_Axiomatization (E)
1777 then
1778 return E;
1779 end if;
1780
1781 -- If E's scope is axiomatized, E is axiomatized
1782
1783 if Present (Scope (E)) then
1784 declare
1785 First_Ax_Parent_Scope : constant Entity_Id :=
1786 Containing_Package_With_Ext_Axioms (Scope (E));
1787 begin
1788 if Present (First_Ax_Parent_Scope) then
1789 return First_Ax_Parent_Scope;
1790 end if;
1791 end;
1792 end if;
1793
1794 -- Otherwise, if E is a package instance, it is axiomatized if the
1795 -- corresponding generic package is axiomatized.
1796
1797 if Ekind (E) = E_Package then
1798 declare
1799 Par : constant Node_Id := Parent (E);
1800 Decl : Node_Id;
1801
1802 begin
1803 if Nkind (Par) = N_Defining_Program_Unit_Name then
1804 Decl := Parent (Par);
1805 else
1806 Decl := Par;
1807 end if;
1808
1809 if Present (Generic_Parent (Decl)) then
1810 return
1811 Containing_Package_With_Ext_Axioms (Generic_Parent (Decl));
1812 end if;
1813 end;
1814 end if;
1815
1816 return Empty;
1817 end Containing_Package_With_Ext_Axioms;
1818
1819 -------------------------------
1820 -- Convert_To_Actual_Subtype --
1821 -------------------------------
1822
1823 procedure Convert_To_Actual_Subtype (Exp : Entity_Id) is
1824 Act_ST : Entity_Id;
1825
1826 begin
1827 Act_ST := Get_Actual_Subtype (Exp);
1828
1829 if Act_ST = Etype (Exp) then
1830 return;
1831 else
1832 Rewrite (Exp, Convert_To (Act_ST, Relocate_Node (Exp)));
1833 Analyze_And_Resolve (Exp, Act_ST);
1834 end if;
1835 end Convert_To_Actual_Subtype;
1836
1837 -----------------------------------
1838 -- Corresponding_Runtime_Package --
1839 -----------------------------------
1840
1841 function Corresponding_Runtime_Package (Typ : Entity_Id) return RTU_Id is
1842 Pkg_Id : RTU_Id := RTU_Null;
1843
1844 begin
1845 pragma Assert (Is_Concurrent_Type (Typ));
1846
1847 if Ekind (Typ) in Protected_Kind then
1848 if Has_Entries (Typ)
1849
1850 -- A protected type without entries that covers an interface and
1851 -- overrides the abstract routines with protected procedures is
1852 -- considered equivalent to a protected type with entries in the
1853 -- context of dispatching select statements. It is sufficient to
1854 -- check for the presence of an interface list in the declaration
1855 -- node to recognize this case.
1856
1857 or else Present (Interface_List (Parent (Typ)))
1858
1859 -- Protected types with interrupt handlers (when not using a
1860 -- restricted profile) are also considered equivalent to
1861 -- protected types with entries. The types which are used
1862 -- (Static_Interrupt_Protection and Dynamic_Interrupt_Protection)
1863 -- are derived from Protection_Entries.
1864
1865 or else (Has_Attach_Handler (Typ) and then not Restricted_Profile)
1866 or else Has_Interrupt_Handler (Typ)
1867 then
1868 if Abort_Allowed
1869 or else Restriction_Active (No_Entry_Queue) = False
1870 or else Restriction_Active (No_Select_Statements) = False
1871 or else Number_Entries (Typ) > 1
1872 or else (Has_Attach_Handler (Typ)
1873 and then not Restricted_Profile)
1874 then
1875 Pkg_Id := System_Tasking_Protected_Objects_Entries;
1876 else
1877 Pkg_Id := System_Tasking_Protected_Objects_Single_Entry;
1878 end if;
1879
1880 else
1881 Pkg_Id := System_Tasking_Protected_Objects;
1882 end if;
1883 end if;
1884
1885 return Pkg_Id;
1886 end Corresponding_Runtime_Package;
1887
1888 -----------------------------------
1889 -- Current_Sem_Unit_Declarations --
1890 -----------------------------------
1891
1892 function Current_Sem_Unit_Declarations return List_Id is
1893 U : Node_Id := Unit (Cunit (Current_Sem_Unit));
1894 Decls : List_Id;
1895
1896 begin
1897 -- If the current unit is a package body, locate the visible
1898 -- declarations of the package spec.
1899
1900 if Nkind (U) = N_Package_Body then
1901 U := Unit (Library_Unit (Cunit (Current_Sem_Unit)));
1902 end if;
1903
1904 if Nkind (U) = N_Package_Declaration then
1905 U := Specification (U);
1906 Decls := Visible_Declarations (U);
1907
1908 if No (Decls) then
1909 Decls := New_List;
1910 Set_Visible_Declarations (U, Decls);
1911 end if;
1912
1913 else
1914 Decls := Declarations (U);
1915
1916 if No (Decls) then
1917 Decls := New_List;
1918 Set_Declarations (U, Decls);
1919 end if;
1920 end if;
1921
1922 return Decls;
1923 end Current_Sem_Unit_Declarations;
1924
1925 -----------------------
1926 -- Duplicate_Subexpr --
1927 -----------------------
1928
1929 function Duplicate_Subexpr
1930 (Exp : Node_Id;
1931 Name_Req : Boolean := False;
1932 Renaming_Req : Boolean := False) return Node_Id
1933 is
1934 begin
1935 Remove_Side_Effects (Exp, Name_Req, Renaming_Req);
1936 return New_Copy_Tree (Exp);
1937 end Duplicate_Subexpr;
1938
1939 ---------------------------------
1940 -- Duplicate_Subexpr_No_Checks --
1941 ---------------------------------
1942
1943 function Duplicate_Subexpr_No_Checks
1944 (Exp : Node_Id;
1945 Name_Req : Boolean := False;
1946 Renaming_Req : Boolean := False;
1947 Related_Id : Entity_Id := Empty;
1948 Is_Low_Bound : Boolean := False;
1949 Is_High_Bound : Boolean := False) return Node_Id
1950 is
1951 New_Exp : Node_Id;
1952
1953 begin
1954 Remove_Side_Effects
1955 (Exp => Exp,
1956 Name_Req => Name_Req,
1957 Renaming_Req => Renaming_Req,
1958 Related_Id => Related_Id,
1959 Is_Low_Bound => Is_Low_Bound,
1960 Is_High_Bound => Is_High_Bound);
1961
1962 New_Exp := New_Copy_Tree (Exp);
1963 Remove_Checks (New_Exp);
1964 return New_Exp;
1965 end Duplicate_Subexpr_No_Checks;
1966
1967 -----------------------------------
1968 -- Duplicate_Subexpr_Move_Checks --
1969 -----------------------------------
1970
1971 function Duplicate_Subexpr_Move_Checks
1972 (Exp : Node_Id;
1973 Name_Req : Boolean := False;
1974 Renaming_Req : Boolean := False) return Node_Id
1975 is
1976 New_Exp : Node_Id;
1977
1978 begin
1979 Remove_Side_Effects (Exp, Name_Req, Renaming_Req);
1980 New_Exp := New_Copy_Tree (Exp);
1981 Remove_Checks (Exp);
1982 return New_Exp;
1983 end Duplicate_Subexpr_Move_Checks;
1984
1985 --------------------
1986 -- Ensure_Defined --
1987 --------------------
1988
1989 procedure Ensure_Defined (Typ : Entity_Id; N : Node_Id) is
1990 IR : Node_Id;
1991
1992 begin
1993 -- An itype reference must only be created if this is a local itype, so
1994 -- that gigi can elaborate it on the proper objstack.
1995
1996 if Is_Itype (Typ) and then Scope (Typ) = Current_Scope then
1997 IR := Make_Itype_Reference (Sloc (N));
1998 Set_Itype (IR, Typ);
1999 Insert_Action (N, IR);
2000 end if;
2001 end Ensure_Defined;
2002
2003 --------------------
2004 -- Entry_Names_OK --
2005 --------------------
2006
2007 function Entry_Names_OK return Boolean is
2008 begin
2009 return
2010 not Restricted_Profile
2011 and then not Global_Discard_Names
2012 and then not Restriction_Active (No_Implicit_Heap_Allocations)
2013 and then not Restriction_Active (No_Local_Allocators);
2014 end Entry_Names_OK;
2015
2016 -------------------
2017 -- Evaluate_Name --
2018 -------------------
2019
2020 procedure Evaluate_Name (Nam : Node_Id) is
2021 K : constant Node_Kind := Nkind (Nam);
2022
2023 begin
2024 -- For an explicit dereference, we simply force the evaluation of the
2025 -- name expression. The dereference provides a value that is the address
2026 -- for the renamed object, and it is precisely this value that we want
2027 -- to preserve.
2028
2029 if K = N_Explicit_Dereference then
2030 Force_Evaluation (Prefix (Nam));
2031
2032 -- For a selected component, we simply evaluate the prefix
2033
2034 elsif K = N_Selected_Component then
2035 Evaluate_Name (Prefix (Nam));
2036
2037 -- For an indexed component, or an attribute reference, we evaluate the
2038 -- prefix, which is itself a name, recursively, and then force the
2039 -- evaluation of all the subscripts (or attribute expressions).
2040
2041 elsif Nkind_In (K, N_Indexed_Component, N_Attribute_Reference) then
2042 Evaluate_Name (Prefix (Nam));
2043
2044 declare
2045 E : Node_Id;
2046
2047 begin
2048 E := First (Expressions (Nam));
2049 while Present (E) loop
2050 Force_Evaluation (E);
2051
2052 if Original_Node (E) /= E then
2053 Set_Do_Range_Check (E, Do_Range_Check (Original_Node (E)));
2054 end if;
2055
2056 Next (E);
2057 end loop;
2058 end;
2059
2060 -- For a slice, we evaluate the prefix, as for the indexed component
2061 -- case and then, if there is a range present, either directly or as the
2062 -- constraint of a discrete subtype indication, we evaluate the two
2063 -- bounds of this range.
2064
2065 elsif K = N_Slice then
2066 Evaluate_Name (Prefix (Nam));
2067 Evaluate_Slice_Bounds (Nam);
2068
2069 -- For a type conversion, the expression of the conversion must be the
2070 -- name of an object, and we simply need to evaluate this name.
2071
2072 elsif K = N_Type_Conversion then
2073 Evaluate_Name (Expression (Nam));
2074
2075 -- For a function call, we evaluate the call
2076
2077 elsif K = N_Function_Call then
2078 Force_Evaluation (Nam);
2079
2080 -- The remaining cases are direct name, operator symbol and character
2081 -- literal. In all these cases, we do nothing, since we want to
2082 -- reevaluate each time the renamed object is used.
2083
2084 else
2085 return;
2086 end if;
2087 end Evaluate_Name;
2088
2089 ---------------------------
2090 -- Evaluate_Slice_Bounds --
2091 ---------------------------
2092
2093 procedure Evaluate_Slice_Bounds (Slice : Node_Id) is
2094 DR : constant Node_Id := Discrete_Range (Slice);
2095 Constr : Node_Id;
2096 Rexpr : Node_Id;
2097
2098 begin
2099 if Nkind (DR) = N_Range then
2100 Force_Evaluation (Low_Bound (DR));
2101 Force_Evaluation (High_Bound (DR));
2102
2103 elsif Nkind (DR) = N_Subtype_Indication then
2104 Constr := Constraint (DR);
2105
2106 if Nkind (Constr) = N_Range_Constraint then
2107 Rexpr := Range_Expression (Constr);
2108
2109 Force_Evaluation (Low_Bound (Rexpr));
2110 Force_Evaluation (High_Bound (Rexpr));
2111 end if;
2112 end if;
2113 end Evaluate_Slice_Bounds;
2114
2115 ---------------------
2116 -- Evolve_And_Then --
2117 ---------------------
2118
2119 procedure Evolve_And_Then (Cond : in out Node_Id; Cond1 : Node_Id) is
2120 begin
2121 if No (Cond) then
2122 Cond := Cond1;
2123 else
2124 Cond :=
2125 Make_And_Then (Sloc (Cond1),
2126 Left_Opnd => Cond,
2127 Right_Opnd => Cond1);
2128 end if;
2129 end Evolve_And_Then;
2130
2131 --------------------
2132 -- Evolve_Or_Else --
2133 --------------------
2134
2135 procedure Evolve_Or_Else (Cond : in out Node_Id; Cond1 : Node_Id) is
2136 begin
2137 if No (Cond) then
2138 Cond := Cond1;
2139 else
2140 Cond :=
2141 Make_Or_Else (Sloc (Cond1),
2142 Left_Opnd => Cond,
2143 Right_Opnd => Cond1);
2144 end if;
2145 end Evolve_Or_Else;
2146
2147 -----------------------------------------
2148 -- Expand_Static_Predicates_In_Choices --
2149 -----------------------------------------
2150
2151 procedure Expand_Static_Predicates_In_Choices (N : Node_Id) is
2152 pragma Assert (Nkind_In (N, N_Case_Statement_Alternative, N_Variant));
2153
2154 Choices : constant List_Id := Discrete_Choices (N);
2155
2156 Choice : Node_Id;
2157 Next_C : Node_Id;
2158 P : Node_Id;
2159 C : Node_Id;
2160
2161 begin
2162 Choice := First (Choices);
2163 while Present (Choice) loop
2164 Next_C := Next (Choice);
2165
2166 -- Check for name of subtype with static predicate
2167
2168 if Is_Entity_Name (Choice)
2169 and then Is_Type (Entity (Choice))
2170 and then Has_Predicates (Entity (Choice))
2171 then
2172 -- Loop through entries in predicate list, converting to choices
2173 -- and inserting in the list before the current choice. Note that
2174 -- if the list is empty, corresponding to a False predicate, then
2175 -- no choices are inserted.
2176
2177 P := First (Static_Discrete_Predicate (Entity (Choice)));
2178 while Present (P) loop
2179
2180 -- If low bound and high bounds are equal, copy simple choice
2181
2182 if Expr_Value (Low_Bound (P)) = Expr_Value (High_Bound (P)) then
2183 C := New_Copy (Low_Bound (P));
2184
2185 -- Otherwise copy a range
2186
2187 else
2188 C := New_Copy (P);
2189 end if;
2190
2191 -- Change Sloc to referencing choice (rather than the Sloc of
2192 -- the predicate declaration element itself).
2193
2194 Set_Sloc (C, Sloc (Choice));
2195 Insert_Before (Choice, C);
2196 Next (P);
2197 end loop;
2198
2199 -- Delete the predicated entry
2200
2201 Remove (Choice);
2202 end if;
2203
2204 -- Move to next choice to check
2205
2206 Choice := Next_C;
2207 end loop;
2208 end Expand_Static_Predicates_In_Choices;
2209
2210 ------------------------------
2211 -- Expand_Subtype_From_Expr --
2212 ------------------------------
2213
2214 -- This function is applicable for both static and dynamic allocation of
2215 -- objects which are constrained by an initial expression. Basically it
2216 -- transforms an unconstrained subtype indication into a constrained one.
2217
2218 -- The expression may also be transformed in certain cases in order to
2219 -- avoid multiple evaluation. In the static allocation case, the general
2220 -- scheme is:
2221
2222 -- Val : T := Expr;
2223
2224 -- is transformed into
2225
2226 -- Val : Constrained_Subtype_of_T := Maybe_Modified_Expr;
2227 --
2228 -- Here are the main cases :
2229 --
2230 -- <if Expr is a Slice>
2231 -- Val : T ([Index_Subtype (Expr)]) := Expr;
2232 --
2233 -- <elsif Expr is a String Literal>
2234 -- Val : T (T'First .. T'First + Length (string literal) - 1) := Expr;
2235 --
2236 -- <elsif Expr is Constrained>
2237 -- subtype T is Type_Of_Expr
2238 -- Val : T := Expr;
2239 --
2240 -- <elsif Expr is an entity_name>
2241 -- Val : T (constraints taken from Expr) := Expr;
2242 --
2243 -- <else>
2244 -- type Axxx is access all T;
2245 -- Rval : Axxx := Expr'ref;
2246 -- Val : T (constraints taken from Rval) := Rval.all;
2247
2248 -- ??? note: when the Expression is allocated in the secondary stack
2249 -- we could use it directly instead of copying it by declaring
2250 -- Val : T (...) renames Rval.all
2251
2252 procedure Expand_Subtype_From_Expr
2253 (N : Node_Id;
2254 Unc_Type : Entity_Id;
2255 Subtype_Indic : Node_Id;
2256 Exp : Node_Id;
2257 Related_Id : Entity_Id := Empty)
2258 is
2259 Loc : constant Source_Ptr := Sloc (N);
2260 Exp_Typ : constant Entity_Id := Etype (Exp);
2261 T : Entity_Id;
2262
2263 begin
2264 -- In general we cannot build the subtype if expansion is disabled,
2265 -- because internal entities may not have been defined. However, to
2266 -- avoid some cascaded errors, we try to continue when the expression is
2267 -- an array (or string), because it is safe to compute the bounds. It is
2268 -- in fact required to do so even in a generic context, because there
2269 -- may be constants that depend on the bounds of a string literal, both
2270 -- standard string types and more generally arrays of characters.
2271
2272 -- In GNATprove mode, these extra subtypes are not needed
2273
2274 if GNATprove_Mode then
2275 return;
2276 end if;
2277
2278 if not Expander_Active
2279 and then (No (Etype (Exp)) or else not Is_String_Type (Etype (Exp)))
2280 then
2281 return;
2282 end if;
2283
2284 if Nkind (Exp) = N_Slice then
2285 declare
2286 Slice_Type : constant Entity_Id := Etype (First_Index (Exp_Typ));
2287
2288 begin
2289 Rewrite (Subtype_Indic,
2290 Make_Subtype_Indication (Loc,
2291 Subtype_Mark => New_Occurrence_Of (Unc_Type, Loc),
2292 Constraint =>
2293 Make_Index_Or_Discriminant_Constraint (Loc,
2294 Constraints => New_List
2295 (New_Occurrence_Of (Slice_Type, Loc)))));
2296
2297 -- This subtype indication may be used later for constraint checks
2298 -- we better make sure that if a variable was used as a bound of
2299 -- of the original slice, its value is frozen.
2300
2301 Evaluate_Slice_Bounds (Exp);
2302 end;
2303
2304 elsif Ekind (Exp_Typ) = E_String_Literal_Subtype then
2305 Rewrite (Subtype_Indic,
2306 Make_Subtype_Indication (Loc,
2307 Subtype_Mark => New_Occurrence_Of (Unc_Type, Loc),
2308 Constraint =>
2309 Make_Index_Or_Discriminant_Constraint (Loc,
2310 Constraints => New_List (
2311 Make_Literal_Range (Loc,
2312 Literal_Typ => Exp_Typ)))));
2313
2314 -- If the type of the expression is an internally generated type it
2315 -- may not be necessary to create a new subtype. However there are two
2316 -- exceptions: references to the current instances, and aliased array
2317 -- object declarations for which the backend needs to create a template.
2318
2319 elsif Is_Constrained (Exp_Typ)
2320 and then not Is_Class_Wide_Type (Unc_Type)
2321 and then
2322 (Nkind (N) /= N_Object_Declaration
2323 or else not Is_Entity_Name (Expression (N))
2324 or else not Comes_From_Source (Entity (Expression (N)))
2325 or else not Is_Array_Type (Exp_Typ)
2326 or else not Aliased_Present (N))
2327 then
2328 if Is_Itype (Exp_Typ) then
2329
2330 -- Within an initialization procedure, a selected component
2331 -- denotes a component of the enclosing record, and it appears as
2332 -- an actual in a call to its own initialization procedure. If
2333 -- this component depends on the outer discriminant, we must
2334 -- generate the proper actual subtype for it.
2335
2336 if Nkind (Exp) = N_Selected_Component
2337 and then Within_Init_Proc
2338 then
2339 declare
2340 Decl : constant Node_Id :=
2341 Build_Actual_Subtype_Of_Component (Exp_Typ, Exp);
2342 begin
2343 if Present (Decl) then
2344 Insert_Action (N, Decl);
2345 T := Defining_Identifier (Decl);
2346 else
2347 T := Exp_Typ;
2348 end if;
2349 end;
2350
2351 -- No need to generate a new subtype
2352
2353 else
2354 T := Exp_Typ;
2355 end if;
2356
2357 else
2358 T := Make_Temporary (Loc, 'T');
2359
2360 Insert_Action (N,
2361 Make_Subtype_Declaration (Loc,
2362 Defining_Identifier => T,
2363 Subtype_Indication => New_Occurrence_Of (Exp_Typ, Loc)));
2364
2365 -- This type is marked as an itype even though it has an explicit
2366 -- declaration since otherwise Is_Generic_Actual_Type can get
2367 -- set, resulting in the generation of spurious errors. (See
2368 -- sem_ch8.Analyze_Package_Renaming and sem_type.covers)
2369
2370 Set_Is_Itype (T);
2371 Set_Associated_Node_For_Itype (T, Exp);
2372 end if;
2373
2374 Rewrite (Subtype_Indic, New_Occurrence_Of (T, Loc));
2375
2376 -- Nothing needs to be done for private types with unknown discriminants
2377 -- if the underlying type is not an unconstrained composite type or it
2378 -- is an unchecked union.
2379
2380 elsif Is_Private_Type (Unc_Type)
2381 and then Has_Unknown_Discriminants (Unc_Type)
2382 and then (not Is_Composite_Type (Underlying_Type (Unc_Type))
2383 or else Is_Constrained (Underlying_Type (Unc_Type))
2384 or else Is_Unchecked_Union (Underlying_Type (Unc_Type)))
2385 then
2386 null;
2387
2388 -- Case of derived type with unknown discriminants where the parent type
2389 -- also has unknown discriminants.
2390
2391 elsif Is_Record_Type (Unc_Type)
2392 and then not Is_Class_Wide_Type (Unc_Type)
2393 and then Has_Unknown_Discriminants (Unc_Type)
2394 and then Has_Unknown_Discriminants (Underlying_Type (Unc_Type))
2395 then
2396 -- Nothing to be done if no underlying record view available
2397
2398 if No (Underlying_Record_View (Unc_Type)) then
2399 null;
2400
2401 -- Otherwise use the Underlying_Record_View to create the proper
2402 -- constrained subtype for an object of a derived type with unknown
2403 -- discriminants.
2404
2405 else
2406 Remove_Side_Effects (Exp);
2407 Rewrite (Subtype_Indic,
2408 Make_Subtype_From_Expr (Exp, Underlying_Record_View (Unc_Type)));
2409 end if;
2410
2411 -- Renamings of class-wide interface types require no equivalent
2412 -- constrained type declarations because we only need to reference
2413 -- the tag component associated with the interface. The same is
2414 -- presumably true for class-wide types in general, so this test
2415 -- is broadened to include all class-wide renamings, which also
2416 -- avoids cases of unbounded recursion in Remove_Side_Effects.
2417 -- (Is this really correct, or are there some cases of class-wide
2418 -- renamings that require action in this procedure???)
2419
2420 elsif Present (N)
2421 and then Nkind (N) = N_Object_Renaming_Declaration
2422 and then Is_Class_Wide_Type (Unc_Type)
2423 then
2424 null;
2425
2426 -- In Ada 95 nothing to be done if the type of the expression is limited
2427 -- because in this case the expression cannot be copied, and its use can
2428 -- only be by reference.
2429
2430 -- In Ada 2005 the context can be an object declaration whose expression
2431 -- is a function that returns in place. If the nominal subtype has
2432 -- unknown discriminants, the call still provides constraints on the
2433 -- object, and we have to create an actual subtype from it.
2434
2435 -- If the type is class-wide, the expression is dynamically tagged and
2436 -- we do not create an actual subtype either. Ditto for an interface.
2437 -- For now this applies only if the type is immutably limited, and the
2438 -- function being called is build-in-place. This will have to be revised
2439 -- when build-in-place functions are generalized to other types.
2440
2441 elsif Is_Limited_View (Exp_Typ)
2442 and then
2443 (Is_Class_Wide_Type (Exp_Typ)
2444 or else Is_Interface (Exp_Typ)
2445 or else not Has_Unknown_Discriminants (Exp_Typ)
2446 or else not Is_Composite_Type (Unc_Type))
2447 then
2448 null;
2449
2450 -- For limited objects initialized with build in place function calls,
2451 -- nothing to be done; otherwise we prematurely introduce an N_Reference
2452 -- node in the expression initializing the object, which breaks the
2453 -- circuitry that detects and adds the additional arguments to the
2454 -- called function.
2455
2456 elsif Is_Build_In_Place_Function_Call (Exp) then
2457 null;
2458
2459 else
2460 Remove_Side_Effects (Exp);
2461 Rewrite (Subtype_Indic,
2462 Make_Subtype_From_Expr (Exp, Unc_Type, Related_Id));
2463 end if;
2464 end Expand_Subtype_From_Expr;
2465
2466 ----------------------
2467 -- Finalize_Address --
2468 ----------------------
2469
2470 function Finalize_Address (Typ : Entity_Id) return Entity_Id is
2471 Utyp : Entity_Id := Typ;
2472
2473 begin
2474 -- Handle protected class-wide or task class-wide types
2475
2476 if Is_Class_Wide_Type (Utyp) then
2477 if Is_Concurrent_Type (Root_Type (Utyp)) then
2478 Utyp := Root_Type (Utyp);
2479
2480 elsif Is_Private_Type (Root_Type (Utyp))
2481 and then Present (Full_View (Root_Type (Utyp)))
2482 and then Is_Concurrent_Type (Full_View (Root_Type (Utyp)))
2483 then
2484 Utyp := Full_View (Root_Type (Utyp));
2485 end if;
2486 end if;
2487
2488 -- Handle private types
2489
2490 if Is_Private_Type (Utyp) and then Present (Full_View (Utyp)) then
2491 Utyp := Full_View (Utyp);
2492 end if;
2493
2494 -- Handle protected and task types
2495
2496 if Is_Concurrent_Type (Utyp)
2497 and then Present (Corresponding_Record_Type (Utyp))
2498 then
2499 Utyp := Corresponding_Record_Type (Utyp);
2500 end if;
2501
2502 Utyp := Underlying_Type (Base_Type (Utyp));
2503
2504 -- Deal with untagged derivation of private views. If the parent is
2505 -- now known to be protected, the finalization routine is the one
2506 -- defined on the corresponding record of the ancestor (corresponding
2507 -- records do not automatically inherit operations, but maybe they
2508 -- should???)
2509
2510 if Is_Untagged_Derivation (Typ) then
2511 if Is_Protected_Type (Typ) then
2512 Utyp := Corresponding_Record_Type (Root_Type (Base_Type (Typ)));
2513
2514 else
2515 Utyp := Underlying_Type (Root_Type (Base_Type (Typ)));
2516
2517 if Is_Protected_Type (Utyp) then
2518 Utyp := Corresponding_Record_Type (Utyp);
2519 end if;
2520 end if;
2521 end if;
2522
2523 -- If the underlying_type is a subtype, we are dealing with the
2524 -- completion of a private type. We need to access the base type and
2525 -- generate a conversion to it.
2526
2527 if Utyp /= Base_Type (Utyp) then
2528 pragma Assert (Is_Private_Type (Typ));
2529
2530 Utyp := Base_Type (Utyp);
2531 end if;
2532
2533 -- When dealing with an internally built full view for a type with
2534 -- unknown discriminants, use the original record type.
2535
2536 if Is_Underlying_Record_View (Utyp) then
2537 Utyp := Etype (Utyp);
2538 end if;
2539
2540 return TSS (Utyp, TSS_Finalize_Address);
2541 end Finalize_Address;
2542
2543 ------------------------
2544 -- Find_Interface_ADT --
2545 ------------------------
2546
2547 function Find_Interface_ADT
2548 (T : Entity_Id;
2549 Iface : Entity_Id) return Elmt_Id
2550 is
2551 ADT : Elmt_Id;
2552 Typ : Entity_Id := T;
2553
2554 begin
2555 pragma Assert (Is_Interface (Iface));
2556
2557 -- Handle private types
2558
2559 if Has_Private_Declaration (Typ) and then Present (Full_View (Typ)) then
2560 Typ := Full_View (Typ);
2561 end if;
2562
2563 -- Handle access types
2564
2565 if Is_Access_Type (Typ) then
2566 Typ := Designated_Type (Typ);
2567 end if;
2568
2569 -- Handle task and protected types implementing interfaces
2570
2571 if Is_Concurrent_Type (Typ) then
2572 Typ := Corresponding_Record_Type (Typ);
2573 end if;
2574
2575 pragma Assert
2576 (not Is_Class_Wide_Type (Typ)
2577 and then Ekind (Typ) /= E_Incomplete_Type);
2578
2579 if Is_Ancestor (Iface, Typ, Use_Full_View => True) then
2580 return First_Elmt (Access_Disp_Table (Typ));
2581
2582 else
2583 ADT := Next_Elmt (Next_Elmt (First_Elmt (Access_Disp_Table (Typ))));
2584 while Present (ADT)
2585 and then Present (Related_Type (Node (ADT)))
2586 and then Related_Type (Node (ADT)) /= Iface
2587 and then not Is_Ancestor (Iface, Related_Type (Node (ADT)),
2588 Use_Full_View => True)
2589 loop
2590 Next_Elmt (ADT);
2591 end loop;
2592
2593 pragma Assert (Present (Related_Type (Node (ADT))));
2594 return ADT;
2595 end if;
2596 end Find_Interface_ADT;
2597
2598 ------------------------
2599 -- Find_Interface_Tag --
2600 ------------------------
2601
2602 function Find_Interface_Tag
2603 (T : Entity_Id;
2604 Iface : Entity_Id) return Entity_Id
2605 is
2606 AI_Tag : Entity_Id;
2607 Found : Boolean := False;
2608 Typ : Entity_Id := T;
2609
2610 procedure Find_Tag (Typ : Entity_Id);
2611 -- Internal subprogram used to recursively climb to the ancestors
2612
2613 --------------
2614 -- Find_Tag --
2615 --------------
2616
2617 procedure Find_Tag (Typ : Entity_Id) is
2618 AI_Elmt : Elmt_Id;
2619 AI : Node_Id;
2620
2621 begin
2622 -- This routine does not handle the case in which the interface is an
2623 -- ancestor of Typ. That case is handled by the enclosing subprogram.
2624
2625 pragma Assert (Typ /= Iface);
2626
2627 -- Climb to the root type handling private types
2628
2629 if Present (Full_View (Etype (Typ))) then
2630 if Full_View (Etype (Typ)) /= Typ then
2631 Find_Tag (Full_View (Etype (Typ)));
2632 end if;
2633
2634 elsif Etype (Typ) /= Typ then
2635 Find_Tag (Etype (Typ));
2636 end if;
2637
2638 -- Traverse the list of interfaces implemented by the type
2639
2640 if not Found
2641 and then Present (Interfaces (Typ))
2642 and then not (Is_Empty_Elmt_List (Interfaces (Typ)))
2643 then
2644 -- Skip the tag associated with the primary table
2645
2646 pragma Assert (Etype (First_Tag_Component (Typ)) = RTE (RE_Tag));
2647 AI_Tag := Next_Tag_Component (First_Tag_Component (Typ));
2648 pragma Assert (Present (AI_Tag));
2649
2650 AI_Elmt := First_Elmt (Interfaces (Typ));
2651 while Present (AI_Elmt) loop
2652 AI := Node (AI_Elmt);
2653
2654 if AI = Iface
2655 or else Is_Ancestor (Iface, AI, Use_Full_View => True)
2656 then
2657 Found := True;
2658 return;
2659 end if;
2660
2661 AI_Tag := Next_Tag_Component (AI_Tag);
2662 Next_Elmt (AI_Elmt);
2663 end loop;
2664 end if;
2665 end Find_Tag;
2666
2667 -- Start of processing for Find_Interface_Tag
2668
2669 begin
2670 pragma Assert (Is_Interface (Iface));
2671
2672 -- Handle access types
2673
2674 if Is_Access_Type (Typ) then
2675 Typ := Designated_Type (Typ);
2676 end if;
2677
2678 -- Handle class-wide types
2679
2680 if Is_Class_Wide_Type (Typ) then
2681 Typ := Root_Type (Typ);
2682 end if;
2683
2684 -- Handle private types
2685
2686 if Has_Private_Declaration (Typ) and then Present (Full_View (Typ)) then
2687 Typ := Full_View (Typ);
2688 end if;
2689
2690 -- Handle entities from the limited view
2691
2692 if Ekind (Typ) = E_Incomplete_Type then
2693 pragma Assert (Present (Non_Limited_View (Typ)));
2694 Typ := Non_Limited_View (Typ);
2695 end if;
2696
2697 -- Handle task and protected types implementing interfaces
2698
2699 if Is_Concurrent_Type (Typ) then
2700 Typ := Corresponding_Record_Type (Typ);
2701 end if;
2702
2703 -- If the interface is an ancestor of the type, then it shared the
2704 -- primary dispatch table.
2705
2706 if Is_Ancestor (Iface, Typ, Use_Full_View => True) then
2707 pragma Assert (Etype (First_Tag_Component (Typ)) = RTE (RE_Tag));
2708 return First_Tag_Component (Typ);
2709
2710 -- Otherwise we need to search for its associated tag component
2711
2712 else
2713 Find_Tag (Typ);
2714 pragma Assert (Found);
2715 return AI_Tag;
2716 end if;
2717 end Find_Interface_Tag;
2718
2719 ---------------------------
2720 -- Find_Optional_Prim_Op --
2721 ---------------------------
2722
2723 function Find_Optional_Prim_Op
2724 (T : Entity_Id; Name : Name_Id) return Entity_Id
2725 is
2726 Prim : Elmt_Id;
2727 Typ : Entity_Id := T;
2728 Op : Entity_Id;
2729
2730 begin
2731 if Is_Class_Wide_Type (Typ) then
2732 Typ := Root_Type (Typ);
2733 end if;
2734
2735 Typ := Underlying_Type (Typ);
2736
2737 -- Loop through primitive operations
2738
2739 Prim := First_Elmt (Primitive_Operations (Typ));
2740 while Present (Prim) loop
2741 Op := Node (Prim);
2742
2743 -- We can retrieve primitive operations by name if it is an internal
2744 -- name. For equality we must check that both of its operands have
2745 -- the same type, to avoid confusion with user-defined equalities
2746 -- than may have a non-symmetric signature.
2747
2748 exit when Chars (Op) = Name
2749 and then
2750 (Name /= Name_Op_Eq
2751 or else Etype (First_Formal (Op)) = Etype (Last_Formal (Op)));
2752
2753 Next_Elmt (Prim);
2754 end loop;
2755
2756 return Node (Prim); -- Empty if not found
2757 end Find_Optional_Prim_Op;
2758
2759 ---------------------------
2760 -- Find_Optional_Prim_Op --
2761 ---------------------------
2762
2763 function Find_Optional_Prim_Op
2764 (T : Entity_Id;
2765 Name : TSS_Name_Type) return Entity_Id
2766 is
2767 Inher_Op : Entity_Id := Empty;
2768 Own_Op : Entity_Id := Empty;
2769 Prim_Elmt : Elmt_Id;
2770 Prim_Id : Entity_Id;
2771 Typ : Entity_Id := T;
2772
2773 begin
2774 if Is_Class_Wide_Type (Typ) then
2775 Typ := Root_Type (Typ);
2776 end if;
2777
2778 Typ := Underlying_Type (Typ);
2779
2780 -- This search is based on the assertion that the dispatching version
2781 -- of the TSS routine always precedes the real primitive.
2782
2783 Prim_Elmt := First_Elmt (Primitive_Operations (Typ));
2784 while Present (Prim_Elmt) loop
2785 Prim_Id := Node (Prim_Elmt);
2786
2787 if Is_TSS (Prim_Id, Name) then
2788 if Present (Alias (Prim_Id)) then
2789 Inher_Op := Prim_Id;
2790 else
2791 Own_Op := Prim_Id;
2792 end if;
2793 end if;
2794
2795 Next_Elmt (Prim_Elmt);
2796 end loop;
2797
2798 if Present (Own_Op) then
2799 return Own_Op;
2800 elsif Present (Inher_Op) then
2801 return Inher_Op;
2802 else
2803 return Empty;
2804 end if;
2805 end Find_Optional_Prim_Op;
2806
2807 ------------------
2808 -- Find_Prim_Op --
2809 ------------------
2810
2811 function Find_Prim_Op
2812 (T : Entity_Id; Name : Name_Id) return Entity_Id
2813 is
2814 Result : constant Entity_Id := Find_Optional_Prim_Op (T, Name);
2815 begin
2816 if No (Result) then
2817 raise Program_Error;
2818 end if;
2819
2820 return Result;
2821 end Find_Prim_Op;
2822
2823 ------------------
2824 -- Find_Prim_Op --
2825 ------------------
2826
2827 function Find_Prim_Op
2828 (T : Entity_Id;
2829 Name : TSS_Name_Type) return Entity_Id
2830 is
2831 Result : constant Entity_Id := Find_Optional_Prim_Op (T, Name);
2832 begin
2833 if No (Result) then
2834 raise Program_Error;
2835 end if;
2836
2837 return Result;
2838 end Find_Prim_Op;
2839
2840 ----------------------------
2841 -- Find_Protection_Object --
2842 ----------------------------
2843
2844 function Find_Protection_Object (Scop : Entity_Id) return Entity_Id is
2845 S : Entity_Id;
2846
2847 begin
2848 S := Scop;
2849 while Present (S) loop
2850 if Ekind_In (S, E_Entry, E_Entry_Family, E_Function, E_Procedure)
2851 and then Present (Protection_Object (S))
2852 then
2853 return Protection_Object (S);
2854 end if;
2855
2856 S := Scope (S);
2857 end loop;
2858
2859 -- If we do not find a Protection object in the scope chain, then
2860 -- something has gone wrong, most likely the object was never created.
2861
2862 raise Program_Error;
2863 end Find_Protection_Object;
2864
2865 --------------------------
2866 -- Find_Protection_Type --
2867 --------------------------
2868
2869 function Find_Protection_Type (Conc_Typ : Entity_Id) return Entity_Id is
2870 Comp : Entity_Id;
2871 Typ : Entity_Id := Conc_Typ;
2872
2873 begin
2874 if Is_Concurrent_Type (Typ) then
2875 Typ := Corresponding_Record_Type (Typ);
2876 end if;
2877
2878 -- Since restriction violations are not considered serious errors, the
2879 -- expander remains active, but may leave the corresponding record type
2880 -- malformed. In such cases, component _object is not available so do
2881 -- not look for it.
2882
2883 if not Analyzed (Typ) then
2884 return Empty;
2885 end if;
2886
2887 Comp := First_Component (Typ);
2888 while Present (Comp) loop
2889 if Chars (Comp) = Name_uObject then
2890 return Base_Type (Etype (Comp));
2891 end if;
2892
2893 Next_Component (Comp);
2894 end loop;
2895
2896 -- The corresponding record of a protected type should always have an
2897 -- _object field.
2898
2899 raise Program_Error;
2900 end Find_Protection_Type;
2901
2902 -----------------------
2903 -- Find_Hook_Context --
2904 -----------------------
2905
2906 function Find_Hook_Context (N : Node_Id) return Node_Id is
2907 Par : Node_Id;
2908 Top : Node_Id;
2909
2910 Wrapped_Node : Node_Id;
2911 -- Note: if we are in a transient scope, we want to reuse it as
2912 -- the context for actions insertion, if possible. But if N is itself
2913 -- part of the stored actions for the current transient scope,
2914 -- then we need to insert at the appropriate (inner) location in
2915 -- the not as an action on Node_To_Be_Wrapped.
2916
2917 In_Cond_Expr : constant Boolean := Within_Case_Or_If_Expression (N);
2918
2919 begin
2920 -- When the node is inside a case/if expression, the lifetime of any
2921 -- temporary controlled object is extended. Find a suitable insertion
2922 -- node by locating the topmost case or if expressions.
2923
2924 if In_Cond_Expr then
2925 Par := N;
2926 Top := N;
2927 while Present (Par) loop
2928 if Nkind_In (Original_Node (Par), N_Case_Expression,
2929 N_If_Expression)
2930 then
2931 Top := Par;
2932
2933 -- Prevent the search from going too far
2934
2935 elsif Is_Body_Or_Package_Declaration (Par) then
2936 exit;
2937 end if;
2938
2939 Par := Parent (Par);
2940 end loop;
2941
2942 -- The topmost case or if expression is now recovered, but it may
2943 -- still not be the correct place to add generated code. Climb to
2944 -- find a parent that is part of a declarative or statement list,
2945 -- and is not a list of actuals in a call.
2946
2947 Par := Top;
2948 while Present (Par) loop
2949 if Is_List_Member (Par)
2950 and then not Nkind_In (Par, N_Component_Association,
2951 N_Discriminant_Association,
2952 N_Parameter_Association,
2953 N_Pragma_Argument_Association)
2954 and then not Nkind_In (Parent (Par), N_Function_Call,
2955 N_Procedure_Call_Statement,
2956 N_Entry_Call_Statement)
2957
2958 then
2959 return Par;
2960
2961 -- Prevent the search from going too far
2962
2963 elsif Is_Body_Or_Package_Declaration (Par) then
2964 exit;
2965 end if;
2966
2967 Par := Parent (Par);
2968 end loop;
2969
2970 return Par;
2971
2972 else
2973 Par := N;
2974 while Present (Par) loop
2975
2976 -- Keep climbing past various operators
2977
2978 if Nkind (Parent (Par)) in N_Op
2979 or else Nkind_In (Parent (Par), N_And_Then, N_Or_Else)
2980 then
2981 Par := Parent (Par);
2982 else
2983 exit;
2984 end if;
2985 end loop;
2986
2987 Top := Par;
2988
2989 -- The node may be located in a pragma in which case return the
2990 -- pragma itself:
2991
2992 -- pragma Precondition (... and then Ctrl_Func_Call ...);
2993
2994 -- Similar case occurs when the node is related to an object
2995 -- declaration or assignment:
2996
2997 -- Obj [: Some_Typ] := ... and then Ctrl_Func_Call ...;
2998
2999 -- Another case to consider is when the node is part of a return
3000 -- statement:
3001
3002 -- return ... and then Ctrl_Func_Call ...;
3003
3004 -- Another case is when the node acts as a formal in a procedure
3005 -- call statement:
3006
3007 -- Proc (... and then Ctrl_Func_Call ...);
3008
3009 if Scope_Is_Transient then
3010 Wrapped_Node := Node_To_Be_Wrapped;
3011 else
3012 Wrapped_Node := Empty;
3013 end if;
3014
3015 while Present (Par) loop
3016 if Par = Wrapped_Node
3017 or else Nkind_In (Par, N_Assignment_Statement,
3018 N_Object_Declaration,
3019 N_Pragma,
3020 N_Procedure_Call_Statement,
3021 N_Simple_Return_Statement)
3022 then
3023 return Par;
3024
3025 -- Prevent the search from going too far
3026
3027 elsif Is_Body_Or_Package_Declaration (Par) then
3028 exit;
3029 end if;
3030
3031 Par := Parent (Par);
3032 end loop;
3033
3034 -- Return the topmost short circuit operator
3035
3036 return Top;
3037 end if;
3038 end Find_Hook_Context;
3039
3040 ------------------------------
3041 -- Following_Address_Clause --
3042 ------------------------------
3043
3044 function Following_Address_Clause (D : Node_Id) return Node_Id is
3045 Id : constant Entity_Id := Defining_Identifier (D);
3046 Result : Node_Id;
3047 Par : Node_Id;
3048
3049 function Check_Decls (D : Node_Id) return Node_Id;
3050 -- This internal function differs from the main function in that it
3051 -- gets called to deal with a following package private part, and
3052 -- it checks declarations starting with D (the main function checks
3053 -- declarations following D). If D is Empty, then Empty is returned.
3054
3055 -----------------
3056 -- Check_Decls --
3057 -----------------
3058
3059 function Check_Decls (D : Node_Id) return Node_Id is
3060 Decl : Node_Id;
3061
3062 begin
3063 Decl := D;
3064 while Present (Decl) loop
3065 if Nkind (Decl) = N_At_Clause
3066 and then Chars (Identifier (Decl)) = Chars (Id)
3067 then
3068 return Decl;
3069
3070 elsif Nkind (Decl) = N_Attribute_Definition_Clause
3071 and then Chars (Decl) = Name_Address
3072 and then Chars (Name (Decl)) = Chars (Id)
3073 then
3074 return Decl;
3075 end if;
3076
3077 Next (Decl);
3078 end loop;
3079
3080 -- Otherwise not found, return Empty
3081
3082 return Empty;
3083 end Check_Decls;
3084
3085 -- Start of processing for Following_Address_Clause
3086
3087 begin
3088 -- If parser detected no address clause for the identifier in question,
3089 -- then the answer is a quick NO, without the need for a search.
3090
3091 if not Get_Name_Table_Boolean1 (Chars (Id)) then
3092 return Empty;
3093 end if;
3094
3095 -- Otherwise search current declarative unit
3096
3097 Result := Check_Decls (Next (D));
3098
3099 if Present (Result) then
3100 return Result;
3101 end if;
3102
3103 -- Check for possible package private part following
3104
3105 Par := Parent (D);
3106
3107 if Nkind (Par) = N_Package_Specification
3108 and then Visible_Declarations (Par) = List_Containing (D)
3109 and then Present (Private_Declarations (Par))
3110 then
3111 -- Private part present, check declarations there
3112
3113 return Check_Decls (First (Private_Declarations (Par)));
3114
3115 else
3116 -- No private part, clause not found, return Empty
3117
3118 return Empty;
3119 end if;
3120 end Following_Address_Clause;
3121
3122 ----------------------
3123 -- Force_Evaluation --
3124 ----------------------
3125
3126 procedure Force_Evaluation
3127 (Exp : Node_Id;
3128 Name_Req : Boolean := False;
3129 Related_Id : Entity_Id := Empty;
3130 Is_Low_Bound : Boolean := False;
3131 Is_High_Bound : Boolean := False;
3132 Mode : Force_Evaluation_Mode := Relaxed)
3133 is
3134 begin
3135 Remove_Side_Effects
3136 (Exp => Exp,
3137 Name_Req => Name_Req,
3138 Variable_Ref => True,
3139 Renaming_Req => False,
3140 Related_Id => Related_Id,
3141 Is_Low_Bound => Is_Low_Bound,
3142 Is_High_Bound => Is_High_Bound,
3143 Check_Side_Effects =>
3144 Is_Static_Expression (Exp)
3145 or else Mode = Relaxed);
3146 end Force_Evaluation;
3147
3148 ---------------------------------
3149 -- Fully_Qualified_Name_String --
3150 ---------------------------------
3151
3152 function Fully_Qualified_Name_String
3153 (E : Entity_Id;
3154 Append_NUL : Boolean := True) return String_Id
3155 is
3156 procedure Internal_Full_Qualified_Name (E : Entity_Id);
3157 -- Compute recursively the qualified name without NUL at the end, adding
3158 -- it to the currently started string being generated
3159
3160 ----------------------------------
3161 -- Internal_Full_Qualified_Name --
3162 ----------------------------------
3163
3164 procedure Internal_Full_Qualified_Name (E : Entity_Id) is
3165 Ent : Entity_Id;
3166
3167 begin
3168 -- Deal properly with child units
3169
3170 if Nkind (E) = N_Defining_Program_Unit_Name then
3171 Ent := Defining_Identifier (E);
3172 else
3173 Ent := E;
3174 end if;
3175
3176 -- Compute qualification recursively (only "Standard" has no scope)
3177
3178 if Present (Scope (Scope (Ent))) then
3179 Internal_Full_Qualified_Name (Scope (Ent));
3180 Store_String_Char (Get_Char_Code ('.'));
3181 end if;
3182
3183 -- Every entity should have a name except some expanded blocks
3184 -- don't bother about those.
3185
3186 if Chars (Ent) = No_Name then
3187 return;
3188 end if;
3189
3190 -- Generates the entity name in upper case
3191
3192 Get_Decoded_Name_String (Chars (Ent));
3193 Set_All_Upper_Case;
3194 Store_String_Chars (Name_Buffer (1 .. Name_Len));
3195 return;
3196 end Internal_Full_Qualified_Name;
3197
3198 -- Start of processing for Full_Qualified_Name
3199
3200 begin
3201 Start_String;
3202 Internal_Full_Qualified_Name (E);
3203
3204 if Append_NUL then
3205 Store_String_Char (Get_Char_Code (ASCII.NUL));
3206 end if;
3207
3208 return End_String;
3209 end Fully_Qualified_Name_String;
3210
3211 ------------------------
3212 -- Generate_Poll_Call --
3213 ------------------------
3214
3215 procedure Generate_Poll_Call (N : Node_Id) is
3216 begin
3217 -- No poll call if polling not active
3218
3219 if not Polling_Required then
3220 return;
3221
3222 -- Otherwise generate require poll call
3223
3224 else
3225 Insert_Before_And_Analyze (N,
3226 Make_Procedure_Call_Statement (Sloc (N),
3227 Name => New_Occurrence_Of (RTE (RE_Poll), Sloc (N))));
3228 end if;
3229 end Generate_Poll_Call;
3230
3231 ---------------------------------
3232 -- Get_Current_Value_Condition --
3233 ---------------------------------
3234
3235 -- Note: the implementation of this procedure is very closely tied to the
3236 -- implementation of Set_Current_Value_Condition. In the Get procedure, we
3237 -- interpret Current_Value fields set by the Set procedure, so the two
3238 -- procedures need to be closely coordinated.
3239
3240 procedure Get_Current_Value_Condition
3241 (Var : Node_Id;
3242 Op : out Node_Kind;
3243 Val : out Node_Id)
3244 is
3245 Loc : constant Source_Ptr := Sloc (Var);
3246 Ent : constant Entity_Id := Entity (Var);
3247
3248 procedure Process_Current_Value_Condition
3249 (N : Node_Id;
3250 S : Boolean);
3251 -- N is an expression which holds either True (S = True) or False (S =
3252 -- False) in the condition. This procedure digs out the expression and
3253 -- if it refers to Ent, sets Op and Val appropriately.
3254
3255 -------------------------------------
3256 -- Process_Current_Value_Condition --
3257 -------------------------------------
3258
3259 procedure Process_Current_Value_Condition
3260 (N : Node_Id;
3261 S : Boolean)
3262 is
3263 Cond : Node_Id;
3264 Prev_Cond : Node_Id;
3265 Sens : Boolean;
3266
3267 begin
3268 Cond := N;
3269 Sens := S;
3270
3271 loop
3272 Prev_Cond := Cond;
3273
3274 -- Deal with NOT operators, inverting sense
3275
3276 while Nkind (Cond) = N_Op_Not loop
3277 Cond := Right_Opnd (Cond);
3278 Sens := not Sens;
3279 end loop;
3280
3281 -- Deal with conversions, qualifications, and expressions with
3282 -- actions.
3283
3284 while Nkind_In (Cond,
3285 N_Type_Conversion,
3286 N_Qualified_Expression,
3287 N_Expression_With_Actions)
3288 loop
3289 Cond := Expression (Cond);
3290 end loop;
3291
3292 exit when Cond = Prev_Cond;
3293 end loop;
3294
3295 -- Deal with AND THEN and AND cases
3296
3297 if Nkind_In (Cond, N_And_Then, N_Op_And) then
3298
3299 -- Don't ever try to invert a condition that is of the form of an
3300 -- AND or AND THEN (since we are not doing sufficiently general
3301 -- processing to allow this).
3302
3303 if Sens = False then
3304 Op := N_Empty;
3305 Val := Empty;
3306 return;
3307 end if;
3308
3309 -- Recursively process AND and AND THEN branches
3310
3311 Process_Current_Value_Condition (Left_Opnd (Cond), True);
3312
3313 if Op /= N_Empty then
3314 return;
3315 end if;
3316
3317 Process_Current_Value_Condition (Right_Opnd (Cond), True);
3318 return;
3319
3320 -- Case of relational operator
3321
3322 elsif Nkind (Cond) in N_Op_Compare then
3323 Op := Nkind (Cond);
3324
3325 -- Invert sense of test if inverted test
3326
3327 if Sens = False then
3328 case Op is
3329 when N_Op_Eq => Op := N_Op_Ne;
3330 when N_Op_Ne => Op := N_Op_Eq;
3331 when N_Op_Lt => Op := N_Op_Ge;
3332 when N_Op_Gt => Op := N_Op_Le;
3333 when N_Op_Le => Op := N_Op_Gt;
3334 when N_Op_Ge => Op := N_Op_Lt;
3335 when others => raise Program_Error;
3336 end case;
3337 end if;
3338
3339 -- Case of entity op value
3340
3341 if Is_Entity_Name (Left_Opnd (Cond))
3342 and then Ent = Entity (Left_Opnd (Cond))
3343 and then Compile_Time_Known_Value (Right_Opnd (Cond))
3344 then
3345 Val := Right_Opnd (Cond);
3346
3347 -- Case of value op entity
3348
3349 elsif Is_Entity_Name (Right_Opnd (Cond))
3350 and then Ent = Entity (Right_Opnd (Cond))
3351 and then Compile_Time_Known_Value (Left_Opnd (Cond))
3352 then
3353 Val := Left_Opnd (Cond);
3354
3355 -- We are effectively swapping operands
3356
3357 case Op is
3358 when N_Op_Eq => null;
3359 when N_Op_Ne => null;
3360 when N_Op_Lt => Op := N_Op_Gt;
3361 when N_Op_Gt => Op := N_Op_Lt;
3362 when N_Op_Le => Op := N_Op_Ge;
3363 when N_Op_Ge => Op := N_Op_Le;
3364 when others => raise Program_Error;
3365 end case;
3366
3367 else
3368 Op := N_Empty;
3369 end if;
3370
3371 return;
3372
3373 elsif Nkind_In (Cond,
3374 N_Type_Conversion,
3375 N_Qualified_Expression,
3376 N_Expression_With_Actions)
3377 then
3378 Cond := Expression (Cond);
3379
3380 -- Case of Boolean variable reference, return as though the
3381 -- reference had said var = True.
3382
3383 else
3384 if Is_Entity_Name (Cond) and then Ent = Entity (Cond) then
3385 Val := New_Occurrence_Of (Standard_True, Sloc (Cond));
3386
3387 if Sens = False then
3388 Op := N_Op_Ne;
3389 else
3390 Op := N_Op_Eq;
3391 end if;
3392 end if;
3393 end if;
3394 end Process_Current_Value_Condition;
3395
3396 -- Start of processing for Get_Current_Value_Condition
3397
3398 begin
3399 Op := N_Empty;
3400 Val := Empty;
3401
3402 -- Immediate return, nothing doing, if this is not an object
3403
3404 if Ekind (Ent) not in Object_Kind then
3405 return;
3406 end if;
3407
3408 -- Otherwise examine current value
3409
3410 declare
3411 CV : constant Node_Id := Current_Value (Ent);
3412 Sens : Boolean;
3413 Stm : Node_Id;
3414
3415 begin
3416 -- If statement. Condition is known true in THEN section, known False
3417 -- in any ELSIF or ELSE part, and unknown outside the IF statement.
3418
3419 if Nkind (CV) = N_If_Statement then
3420
3421 -- Before start of IF statement
3422
3423 if Loc < Sloc (CV) then
3424 return;
3425
3426 -- After end of IF statement
3427
3428 elsif Loc >= Sloc (CV) + Text_Ptr (UI_To_Int (End_Span (CV))) then
3429 return;
3430 end if;
3431
3432 -- At this stage we know that we are within the IF statement, but
3433 -- unfortunately, the tree does not record the SLOC of the ELSE so
3434 -- we cannot use a simple SLOC comparison to distinguish between
3435 -- the then/else statements, so we have to climb the tree.
3436
3437 declare
3438 N : Node_Id;
3439
3440 begin
3441 N := Parent (Var);
3442 while Parent (N) /= CV loop
3443 N := Parent (N);
3444
3445 -- If we fall off the top of the tree, then that's odd, but
3446 -- perhaps it could occur in some error situation, and the
3447 -- safest response is simply to assume that the outcome of
3448 -- the condition is unknown. No point in bombing during an
3449 -- attempt to optimize things.
3450
3451 if No (N) then
3452 return;
3453 end if;
3454 end loop;
3455
3456 -- Now we have N pointing to a node whose parent is the IF
3457 -- statement in question, so now we can tell if we are within
3458 -- the THEN statements.
3459
3460 if Is_List_Member (N)
3461 and then List_Containing (N) = Then_Statements (CV)
3462 then
3463 Sens := True;
3464
3465 -- If the variable reference does not come from source, we
3466 -- cannot reliably tell whether it appears in the else part.
3467 -- In particular, if it appears in generated code for a node
3468 -- that requires finalization, it may be attached to a list
3469 -- that has not been yet inserted into the code. For now,
3470 -- treat it as unknown.
3471
3472 elsif not Comes_From_Source (N) then
3473 return;
3474
3475 -- Otherwise we must be in ELSIF or ELSE part
3476
3477 else
3478 Sens := False;
3479 end if;
3480 end;
3481
3482 -- ELSIF part. Condition is known true within the referenced
3483 -- ELSIF, known False in any subsequent ELSIF or ELSE part,
3484 -- and unknown before the ELSE part or after the IF statement.
3485
3486 elsif Nkind (CV) = N_Elsif_Part then
3487
3488 -- if the Elsif_Part had condition_actions, the elsif has been
3489 -- rewritten as a nested if, and the original elsif_part is
3490 -- detached from the tree, so there is no way to obtain useful
3491 -- information on the current value of the variable.
3492 -- Can this be improved ???
3493
3494 if No (Parent (CV)) then
3495 return;
3496 end if;
3497
3498 Stm := Parent (CV);
3499
3500 -- If the tree has been otherwise rewritten there is nothing
3501 -- else to be done either.
3502
3503 if Nkind (Stm) /= N_If_Statement then
3504 return;
3505 end if;
3506
3507 -- Before start of ELSIF part
3508
3509 if Loc < Sloc (CV) then
3510 return;
3511
3512 -- After end of IF statement
3513
3514 elsif Loc >= Sloc (Stm) +
3515 Text_Ptr (UI_To_Int (End_Span (Stm)))
3516 then
3517 return;
3518 end if;
3519
3520 -- Again we lack the SLOC of the ELSE, so we need to climb the
3521 -- tree to see if we are within the ELSIF part in question.
3522
3523 declare
3524 N : Node_Id;
3525
3526 begin
3527 N := Parent (Var);
3528 while Parent (N) /= Stm loop
3529 N := Parent (N);
3530
3531 -- If we fall off the top of the tree, then that's odd, but
3532 -- perhaps it could occur in some error situation, and the
3533 -- safest response is simply to assume that the outcome of
3534 -- the condition is unknown. No point in bombing during an
3535 -- attempt to optimize things.
3536
3537 if No (N) then
3538 return;
3539 end if;
3540 end loop;
3541
3542 -- Now we have N pointing to a node whose parent is the IF
3543 -- statement in question, so see if is the ELSIF part we want.
3544 -- the THEN statements.
3545
3546 if N = CV then
3547 Sens := True;
3548
3549 -- Otherwise we must be in subsequent ELSIF or ELSE part
3550
3551 else
3552 Sens := False;
3553 end if;
3554 end;
3555
3556 -- Iteration scheme of while loop. The condition is known to be
3557 -- true within the body of the loop.
3558
3559 elsif Nkind (CV) = N_Iteration_Scheme then
3560 declare
3561 Loop_Stmt : constant Node_Id := Parent (CV);
3562
3563 begin
3564 -- Before start of body of loop
3565
3566 if Loc < Sloc (Loop_Stmt) then
3567 return;
3568
3569 -- After end of LOOP statement
3570
3571 elsif Loc >= Sloc (End_Label (Loop_Stmt)) then
3572 return;
3573
3574 -- We are within the body of the loop
3575
3576 else
3577 Sens := True;
3578 end if;
3579 end;
3580
3581 -- All other cases of Current_Value settings
3582
3583 else
3584 return;
3585 end if;
3586
3587 -- If we fall through here, then we have a reportable condition, Sens
3588 -- is True if the condition is true and False if it needs inverting.
3589
3590 Process_Current_Value_Condition (Condition (CV), Sens);
3591 end;
3592 end Get_Current_Value_Condition;
3593
3594 ---------------------
3595 -- Get_Stream_Size --
3596 ---------------------
3597
3598 function Get_Stream_Size (E : Entity_Id) return Uint is
3599 begin
3600 -- If we have a Stream_Size clause for this type use it
3601
3602 if Has_Stream_Size_Clause (E) then
3603 return Static_Integer (Expression (Stream_Size_Clause (E)));
3604
3605 -- Otherwise the Stream_Size if the size of the type
3606
3607 else
3608 return Esize (E);
3609 end if;
3610 end Get_Stream_Size;
3611
3612 ---------------------------
3613 -- Has_Access_Constraint --
3614 ---------------------------
3615
3616 function Has_Access_Constraint (E : Entity_Id) return Boolean is
3617 Disc : Entity_Id;
3618 T : constant Entity_Id := Etype (E);
3619
3620 begin
3621 if Has_Per_Object_Constraint (E) and then Has_Discriminants (T) then
3622 Disc := First_Discriminant (T);
3623 while Present (Disc) loop
3624 if Is_Access_Type (Etype (Disc)) then
3625 return True;
3626 end if;
3627
3628 Next_Discriminant (Disc);
3629 end loop;
3630
3631 return False;
3632 else
3633 return False;
3634 end if;
3635 end Has_Access_Constraint;
3636
3637 -----------------------------------------------------
3638 -- Has_Annotate_Pragma_For_External_Axiomatization --
3639 -----------------------------------------------------
3640
3641 function Has_Annotate_Pragma_For_External_Axiomatization
3642 (E : Entity_Id) return Boolean
3643 is
3644 function Is_Annotate_Pragma_For_External_Axiomatization
3645 (N : Node_Id) return Boolean;
3646 -- Returns whether N is
3647 -- pragma Annotate (GNATprove, External_Axiomatization);
3648
3649 ----------------------------------------------------
3650 -- Is_Annotate_Pragma_For_External_Axiomatization --
3651 ----------------------------------------------------
3652
3653 -- The general form of pragma Annotate is
3654
3655 -- pragma Annotate (IDENTIFIER [, IDENTIFIER {, ARG}]);
3656 -- ARG ::= NAME | EXPRESSION
3657
3658 -- The first two arguments are by convention intended to refer to an
3659 -- external tool and a tool-specific function. These arguments are
3660 -- not analyzed.
3661
3662 -- The following is used to annotate a package specification which
3663 -- GNATprove should treat specially, because the axiomatization of
3664 -- this unit is given by the user instead of being automatically
3665 -- generated.
3666
3667 -- pragma Annotate (GNATprove, External_Axiomatization);
3668
3669 function Is_Annotate_Pragma_For_External_Axiomatization
3670 (N : Node_Id) return Boolean
3671 is
3672 Name_GNATprove : constant String :=
3673 "gnatprove";
3674 Name_External_Axiomatization : constant String :=
3675 "external_axiomatization";
3676 -- Special names
3677
3678 begin
3679 if Nkind (N) = N_Pragma
3680 and then Get_Pragma_Id (Pragma_Name (N)) = Pragma_Annotate
3681 and then List_Length (Pragma_Argument_Associations (N)) = 2
3682 then
3683 declare
3684 Arg1 : constant Node_Id :=
3685 First (Pragma_Argument_Associations (N));
3686 Arg2 : constant Node_Id := Next (Arg1);
3687 Nam1 : Name_Id;
3688 Nam2 : Name_Id;
3689
3690 begin
3691 -- Fill in Name_Buffer with Name_GNATprove first, and then with
3692 -- Name_External_Axiomatization so that Name_Find returns the
3693 -- corresponding name. This takes care of all possible casings.
3694
3695 Name_Len := 0;
3696 Add_Str_To_Name_Buffer (Name_GNATprove);
3697 Nam1 := Name_Find;
3698
3699 Name_Len := 0;
3700 Add_Str_To_Name_Buffer (Name_External_Axiomatization);
3701 Nam2 := Name_Find;
3702
3703 return Chars (Get_Pragma_Arg (Arg1)) = Nam1
3704 and then
3705 Chars (Get_Pragma_Arg (Arg2)) = Nam2;
3706 end;
3707
3708 else
3709 return False;
3710 end if;
3711 end Is_Annotate_Pragma_For_External_Axiomatization;
3712
3713 -- Local variables
3714
3715 Decl : Node_Id;
3716 Vis_Decls : List_Id;
3717 N : Node_Id;
3718
3719 -- Start of processing for Has_Annotate_Pragma_For_External_Axiomatization
3720
3721 begin
3722 if Nkind (Parent (E)) = N_Defining_Program_Unit_Name then
3723 Decl := Parent (Parent (E));
3724 else
3725 Decl := Parent (E);
3726 end if;
3727
3728 Vis_Decls := Visible_Declarations (Decl);
3729
3730 N := First (Vis_Decls);
3731 while Present (N) loop
3732
3733 -- Skip declarations generated by the frontend. Skip all pragmas
3734 -- that are not the desired Annotate pragma. Stop the search on
3735 -- the first non-pragma source declaration.
3736
3737 if Comes_From_Source (N) then
3738 if Nkind (N) = N_Pragma then
3739 if Is_Annotate_Pragma_For_External_Axiomatization (N) then
3740 return True;
3741 end if;
3742 else
3743 return False;
3744 end if;
3745 end if;
3746
3747 Next (N);
3748 end loop;
3749
3750 return False;
3751 end Has_Annotate_Pragma_For_External_Axiomatization;
3752
3753 --------------------
3754 -- Homonym_Number --
3755 --------------------
3756
3757 function Homonym_Number (Subp : Entity_Id) return Nat is
3758 Count : Nat;
3759 Hom : Entity_Id;
3760
3761 begin
3762 Count := 1;
3763 Hom := Homonym (Subp);
3764 while Present (Hom) loop
3765 if Scope (Hom) = Scope (Subp) then
3766 Count := Count + 1;
3767 end if;
3768
3769 Hom := Homonym (Hom);
3770 end loop;
3771
3772 return Count;
3773 end Homonym_Number;
3774
3775 -----------------------------------
3776 -- In_Library_Level_Package_Body --
3777 -----------------------------------
3778
3779 function In_Library_Level_Package_Body (Id : Entity_Id) return Boolean is
3780 begin
3781 -- First determine whether the entity appears at the library level, then
3782 -- look at the containing unit.
3783
3784 if Is_Library_Level_Entity (Id) then
3785 declare
3786 Container : constant Node_Id := Cunit (Get_Source_Unit (Id));
3787
3788 begin
3789 return Nkind (Unit (Container)) = N_Package_Body;
3790 end;
3791 end if;
3792
3793 return False;
3794 end In_Library_Level_Package_Body;
3795
3796 ------------------------------
3797 -- In_Unconditional_Context --
3798 ------------------------------
3799
3800 function In_Unconditional_Context (Node : Node_Id) return Boolean is
3801 P : Node_Id;
3802
3803 begin
3804 P := Node;
3805 while Present (P) loop
3806 case Nkind (P) is
3807 when N_Subprogram_Body =>
3808 return True;
3809
3810 when N_If_Statement =>
3811 return False;
3812
3813 when N_Loop_Statement =>
3814 return False;
3815
3816 when N_Case_Statement =>
3817 return False;
3818
3819 when others =>
3820 P := Parent (P);
3821 end case;
3822 end loop;
3823
3824 return False;
3825 end In_Unconditional_Context;
3826
3827 -------------------
3828 -- Insert_Action --
3829 -------------------
3830
3831 procedure Insert_Action (Assoc_Node : Node_Id; Ins_Action : Node_Id) is
3832 begin
3833 if Present (Ins_Action) then
3834 Insert_Actions (Assoc_Node, New_List (Ins_Action));
3835 end if;
3836 end Insert_Action;
3837
3838 -- Version with check(s) suppressed
3839
3840 procedure Insert_Action
3841 (Assoc_Node : Node_Id; Ins_Action : Node_Id; Suppress : Check_Id)
3842 is
3843 begin
3844 Insert_Actions (Assoc_Node, New_List (Ins_Action), Suppress);
3845 end Insert_Action;
3846
3847 -------------------------
3848 -- Insert_Action_After --
3849 -------------------------
3850
3851 procedure Insert_Action_After
3852 (Assoc_Node : Node_Id;
3853 Ins_Action : Node_Id)
3854 is
3855 begin
3856 Insert_Actions_After (Assoc_Node, New_List (Ins_Action));
3857 end Insert_Action_After;
3858
3859 --------------------
3860 -- Insert_Actions --
3861 --------------------
3862
3863 procedure Insert_Actions (Assoc_Node : Node_Id; Ins_Actions : List_Id) is
3864 N : Node_Id;
3865 P : Node_Id;
3866
3867 Wrapped_Node : Node_Id := Empty;
3868
3869 begin
3870 if No (Ins_Actions) or else Is_Empty_List (Ins_Actions) then
3871 return;
3872 end if;
3873
3874 -- Ignore insert of actions from inside default expression (or other
3875 -- similar "spec expression") in the special spec-expression analyze
3876 -- mode. Any insertions at this point have no relevance, since we are
3877 -- only doing the analyze to freeze the types of any static expressions.
3878 -- See section "Handling of Default Expressions" in the spec of package
3879 -- Sem for further details.
3880
3881 if In_Spec_Expression then
3882 return;
3883 end if;
3884
3885 -- If the action derives from stuff inside a record, then the actions
3886 -- are attached to the current scope, to be inserted and analyzed on
3887 -- exit from the scope. The reason for this is that we may also be
3888 -- generating freeze actions at the same time, and they must eventually
3889 -- be elaborated in the correct order.
3890
3891 if Is_Record_Type (Current_Scope)
3892 and then not Is_Frozen (Current_Scope)
3893 then
3894 if No (Scope_Stack.Table
3895 (Scope_Stack.Last).Pending_Freeze_Actions)
3896 then
3897 Scope_Stack.Table (Scope_Stack.Last).Pending_Freeze_Actions :=
3898 Ins_Actions;
3899 else
3900 Append_List
3901 (Ins_Actions,
3902 Scope_Stack.Table (Scope_Stack.Last).Pending_Freeze_Actions);
3903 end if;
3904
3905 return;
3906 end if;
3907
3908 -- We now intend to climb up the tree to find the right point to
3909 -- insert the actions. We start at Assoc_Node, unless this node is a
3910 -- subexpression in which case we start with its parent. We do this for
3911 -- two reasons. First it speeds things up. Second, if Assoc_Node is
3912 -- itself one of the special nodes like N_And_Then, then we assume that
3913 -- an initial request to insert actions for such a node does not expect
3914 -- the actions to get deposited in the node for later handling when the
3915 -- node is expanded, since clearly the node is being dealt with by the
3916 -- caller. Note that in the subexpression case, N is always the child we
3917 -- came from.
3918
3919 -- N_Raise_xxx_Error is an annoying special case, it is a statement
3920 -- if it has type Standard_Void_Type, and a subexpression otherwise.
3921 -- Procedure calls, and similarly procedure attribute references, are
3922 -- also statements.
3923
3924 if Nkind (Assoc_Node) in N_Subexpr
3925 and then (Nkind (Assoc_Node) not in N_Raise_xxx_Error
3926 or else Etype (Assoc_Node) /= Standard_Void_Type)
3927 and then Nkind (Assoc_Node) /= N_Procedure_Call_Statement
3928 and then (Nkind (Assoc_Node) /= N_Attribute_Reference
3929 or else not Is_Procedure_Attribute_Name
3930 (Attribute_Name (Assoc_Node)))
3931 then
3932 N := Assoc_Node;
3933 P := Parent (Assoc_Node);
3934
3935 -- Non-subexpression case. Note that N is initially Empty in this case
3936 -- (N is only guaranteed Non-Empty in the subexpr case).
3937
3938 else
3939 N := Empty;
3940 P := Assoc_Node;
3941 end if;
3942
3943 -- Capture root of the transient scope
3944
3945 if Scope_Is_Transient then
3946 Wrapped_Node := Node_To_Be_Wrapped;
3947 end if;
3948
3949 loop
3950 pragma Assert (Present (P));
3951
3952 -- Make sure that inserted actions stay in the transient scope
3953
3954 if Present (Wrapped_Node) and then N = Wrapped_Node then
3955 Store_Before_Actions_In_Scope (Ins_Actions);
3956 return;
3957 end if;
3958
3959 case Nkind (P) is
3960
3961 -- Case of right operand of AND THEN or OR ELSE. Put the actions
3962 -- in the Actions field of the right operand. They will be moved
3963 -- out further when the AND THEN or OR ELSE operator is expanded.
3964 -- Nothing special needs to be done for the left operand since
3965 -- in that case the actions are executed unconditionally.
3966
3967 when N_Short_Circuit =>
3968 if N = Right_Opnd (P) then
3969
3970 -- We are now going to either append the actions to the
3971 -- actions field of the short-circuit operation. We will
3972 -- also analyze the actions now.
3973
3974 -- This analysis is really too early, the proper thing would
3975 -- be to just park them there now, and only analyze them if
3976 -- we find we really need them, and to it at the proper
3977 -- final insertion point. However attempting to this proved
3978 -- tricky, so for now we just kill current values before and
3979 -- after the analyze call to make sure we avoid peculiar
3980 -- optimizations from this out of order insertion.
3981
3982 Kill_Current_Values;
3983
3984 -- If P has already been expanded, we can't park new actions
3985 -- on it, so we need to expand them immediately, introducing
3986 -- an Expression_With_Actions. N can't be an expression
3987 -- with actions, or else then the actions would have been
3988 -- inserted at an inner level.
3989
3990 if Analyzed (P) then
3991 pragma Assert (Nkind (N) /= N_Expression_With_Actions);
3992 Rewrite (N,
3993 Make_Expression_With_Actions (Sloc (N),
3994 Actions => Ins_Actions,
3995 Expression => Relocate_Node (N)));
3996 Analyze_And_Resolve (N);
3997
3998 elsif Present (Actions (P)) then
3999 Insert_List_After_And_Analyze
4000 (Last (Actions (P)), Ins_Actions);
4001 else
4002 Set_Actions (P, Ins_Actions);
4003 Analyze_List (Actions (P));
4004 end if;
4005
4006 Kill_Current_Values;
4007
4008 return;
4009 end if;
4010
4011 -- Then or Else dependent expression of an if expression. Add
4012 -- actions to Then_Actions or Else_Actions field as appropriate.
4013 -- The actions will be moved further out when the if is expanded.
4014
4015 when N_If_Expression =>
4016 declare
4017 ThenX : constant Node_Id := Next (First (Expressions (P)));
4018 ElseX : constant Node_Id := Next (ThenX);
4019
4020 begin
4021 -- If the enclosing expression is already analyzed, as
4022 -- is the case for nested elaboration checks, insert the
4023 -- conditional further out.
4024
4025 if Analyzed (P) then
4026 null;
4027
4028 -- Actions belong to the then expression, temporarily place
4029 -- them as Then_Actions of the if expression. They will be
4030 -- moved to the proper place later when the if expression
4031 -- is expanded.
4032
4033 elsif N = ThenX then
4034 if Present (Then_Actions (P)) then
4035 Insert_List_After_And_Analyze
4036 (Last (Then_Actions (P)), Ins_Actions);
4037 else
4038 Set_Then_Actions (P, Ins_Actions);
4039 Analyze_List (Then_Actions (P));
4040 end if;
4041
4042 return;
4043
4044 -- Actions belong to the else expression, temporarily place
4045 -- them as Else_Actions of the if expression. They will be
4046 -- moved to the proper place later when the if expression
4047 -- is expanded.
4048
4049 elsif N = ElseX then
4050 if Present (Else_Actions (P)) then
4051 Insert_List_After_And_Analyze
4052 (Last (Else_Actions (P)), Ins_Actions);
4053 else
4054 Set_Else_Actions (P, Ins_Actions);
4055 Analyze_List (Else_Actions (P));
4056 end if;
4057
4058 return;
4059
4060 -- Actions belong to the condition. In this case they are
4061 -- unconditionally executed, and so we can continue the
4062 -- search for the proper insert point.
4063
4064 else
4065 null;
4066 end if;
4067 end;
4068
4069 -- Alternative of case expression, we place the action in the
4070 -- Actions field of the case expression alternative, this will
4071 -- be handled when the case expression is expanded.
4072
4073 when N_Case_Expression_Alternative =>
4074 if Present (Actions (P)) then
4075 Insert_List_After_And_Analyze
4076 (Last (Actions (P)), Ins_Actions);
4077 else
4078 Set_Actions (P, Ins_Actions);
4079 Analyze_List (Actions (P));
4080 end if;
4081
4082 return;
4083
4084 -- Case of appearing within an Expressions_With_Actions node. When
4085 -- the new actions come from the expression of the expression with
4086 -- actions, they must be added to the existing actions. The other
4087 -- alternative is when the new actions are related to one of the
4088 -- existing actions of the expression with actions, and should
4089 -- never reach here: if actions are inserted on a statement
4090 -- within the Actions of an expression with actions, or on some
4091 -- sub-expression of such a statement, then the outermost proper
4092 -- insertion point is right before the statement, and we should
4093 -- never climb up as far as the N_Expression_With_Actions itself.
4094
4095 when N_Expression_With_Actions =>
4096 if N = Expression (P) then
4097 if Is_Empty_List (Actions (P)) then
4098 Append_List_To (Actions (P), Ins_Actions);
4099 Analyze_List (Actions (P));
4100 else
4101 Insert_List_After_And_Analyze
4102 (Last (Actions (P)), Ins_Actions);
4103 end if;
4104
4105 return;
4106
4107 else
4108 raise Program_Error;
4109 end if;
4110
4111 -- Case of appearing in the condition of a while expression or
4112 -- elsif. We insert the actions into the Condition_Actions field.
4113 -- They will be moved further out when the while loop or elsif
4114 -- is analyzed.
4115
4116 when N_Iteration_Scheme |
4117 N_Elsif_Part
4118 =>
4119 if N = Condition (P) then
4120 if Present (Condition_Actions (P)) then
4121 Insert_List_After_And_Analyze
4122 (Last (Condition_Actions (P)), Ins_Actions);
4123 else
4124 Set_Condition_Actions (P, Ins_Actions);
4125
4126 -- Set the parent of the insert actions explicitly. This
4127 -- is not a syntactic field, but we need the parent field
4128 -- set, in particular so that freeze can understand that
4129 -- it is dealing with condition actions, and properly
4130 -- insert the freezing actions.
4131
4132 Set_Parent (Ins_Actions, P);
4133 Analyze_List (Condition_Actions (P));
4134 end if;
4135
4136 return;
4137 end if;
4138
4139 -- Statements, declarations, pragmas, representation clauses
4140
4141 when
4142 -- Statements
4143
4144 N_Procedure_Call_Statement |
4145 N_Statement_Other_Than_Procedure_Call |
4146
4147 -- Pragmas
4148
4149 N_Pragma |
4150
4151 -- Representation_Clause
4152
4153 N_At_Clause |
4154 N_Attribute_Definition_Clause |
4155 N_Enumeration_Representation_Clause |
4156 N_Record_Representation_Clause |
4157
4158 -- Declarations
4159
4160 N_Abstract_Subprogram_Declaration |
4161 N_Entry_Body |
4162 N_Exception_Declaration |
4163 N_Exception_Renaming_Declaration |
4164 N_Expression_Function |
4165 N_Formal_Abstract_Subprogram_Declaration |
4166 N_Formal_Concrete_Subprogram_Declaration |
4167 N_Formal_Object_Declaration |
4168 N_Formal_Type_Declaration |
4169 N_Full_Type_Declaration |
4170 N_Function_Instantiation |
4171 N_Generic_Function_Renaming_Declaration |
4172 N_Generic_Package_Declaration |
4173 N_Generic_Package_Renaming_Declaration |
4174 N_Generic_Procedure_Renaming_Declaration |
4175 N_Generic_Subprogram_Declaration |
4176 N_Implicit_Label_Declaration |
4177 N_Incomplete_Type_Declaration |
4178 N_Number_Declaration |
4179 N_Object_Declaration |
4180 N_Object_Renaming_Declaration |
4181 N_Package_Body |
4182 N_Package_Body_Stub |
4183 N_Package_Declaration |
4184 N_Package_Instantiation |
4185 N_Package_Renaming_Declaration |
4186 N_Private_Extension_Declaration |
4187 N_Private_Type_Declaration |
4188 N_Procedure_Instantiation |
4189 N_Protected_Body |
4190 N_Protected_Body_Stub |
4191 N_Protected_Type_Declaration |
4192 N_Single_Task_Declaration |
4193 N_Subprogram_Body |
4194 N_Subprogram_Body_Stub |
4195 N_Subprogram_Declaration |
4196 N_Subprogram_Renaming_Declaration |
4197 N_Subtype_Declaration |
4198 N_Task_Body |
4199 N_Task_Body_Stub |
4200 N_Task_Type_Declaration |
4201
4202 -- Use clauses can appear in lists of declarations
4203
4204 N_Use_Package_Clause |
4205 N_Use_Type_Clause |
4206
4207 -- Freeze entity behaves like a declaration or statement
4208
4209 N_Freeze_Entity |
4210 N_Freeze_Generic_Entity
4211 =>
4212 -- Do not insert here if the item is not a list member (this
4213 -- happens for example with a triggering statement, and the
4214 -- proper approach is to insert before the entire select).
4215
4216 if not Is_List_Member (P) then
4217 null;
4218
4219 -- Do not insert if parent of P is an N_Component_Association
4220 -- node (i.e. we are in the context of an N_Aggregate or
4221 -- N_Extension_Aggregate node. In this case we want to insert
4222 -- before the entire aggregate.
4223
4224 elsif Nkind (Parent (P)) = N_Component_Association then
4225 null;
4226
4227 -- Do not insert if the parent of P is either an N_Variant node
4228 -- or an N_Record_Definition node, meaning in either case that
4229 -- P is a member of a component list, and that therefore the
4230 -- actions should be inserted outside the complete record
4231 -- declaration.
4232
4233 elsif Nkind_In (Parent (P), N_Variant, N_Record_Definition) then
4234 null;
4235
4236 -- Do not insert freeze nodes within the loop generated for
4237 -- an aggregate, because they may be elaborated too late for
4238 -- subsequent use in the back end: within a package spec the
4239 -- loop is part of the elaboration procedure and is only
4240 -- elaborated during the second pass.
4241
4242 -- If the loop comes from source, or the entity is local to the
4243 -- loop itself it must remain within.
4244
4245 elsif Nkind (Parent (P)) = N_Loop_Statement
4246 and then not Comes_From_Source (Parent (P))
4247 and then Nkind (First (Ins_Actions)) = N_Freeze_Entity
4248 and then
4249 Scope (Entity (First (Ins_Actions))) /= Current_Scope
4250 then
4251 null;
4252
4253 -- Otherwise we can go ahead and do the insertion
4254
4255 elsif P = Wrapped_Node then
4256 Store_Before_Actions_In_Scope (Ins_Actions);
4257 return;
4258
4259 else
4260 Insert_List_Before_And_Analyze (P, Ins_Actions);
4261 return;
4262 end if;
4263
4264 -- A special case, N_Raise_xxx_Error can act either as a statement
4265 -- or a subexpression. We tell the difference by looking at the
4266 -- Etype. It is set to Standard_Void_Type in the statement case.
4267
4268 when
4269 N_Raise_xxx_Error =>
4270 if Etype (P) = Standard_Void_Type then
4271 if P = Wrapped_Node then
4272 Store_Before_Actions_In_Scope (Ins_Actions);
4273 else
4274 Insert_List_Before_And_Analyze (P, Ins_Actions);
4275 end if;
4276
4277 return;
4278
4279 -- In the subexpression case, keep climbing
4280
4281 else
4282 null;
4283 end if;
4284
4285 -- If a component association appears within a loop created for
4286 -- an array aggregate, attach the actions to the association so
4287 -- they can be subsequently inserted within the loop. For other
4288 -- component associations insert outside of the aggregate. For
4289 -- an association that will generate a loop, its Loop_Actions
4290 -- attribute is already initialized (see exp_aggr.adb).
4291
4292 -- The list of loop_actions can in turn generate additional ones,
4293 -- that are inserted before the associated node. If the associated
4294 -- node is outside the aggregate, the new actions are collected
4295 -- at the end of the loop actions, to respect the order in which
4296 -- they are to be elaborated.
4297
4298 when
4299 N_Component_Association =>
4300 if Nkind (Parent (P)) = N_Aggregate
4301 and then Present (Loop_Actions (P))
4302 then
4303 if Is_Empty_List (Loop_Actions (P)) then
4304 Set_Loop_Actions (P, Ins_Actions);
4305 Analyze_List (Ins_Actions);
4306
4307 else
4308 declare
4309 Decl : Node_Id;
4310
4311 begin
4312 -- Check whether these actions were generated by a
4313 -- declaration that is part of the loop_ actions
4314 -- for the component_association.
4315
4316 Decl := Assoc_Node;
4317 while Present (Decl) loop
4318 exit when Parent (Decl) = P
4319 and then Is_List_Member (Decl)
4320 and then
4321 List_Containing (Decl) = Loop_Actions (P);
4322 Decl := Parent (Decl);
4323 end loop;
4324
4325 if Present (Decl) then
4326 Insert_List_Before_And_Analyze
4327 (Decl, Ins_Actions);
4328 else
4329 Insert_List_After_And_Analyze
4330 (Last (Loop_Actions (P)), Ins_Actions);
4331 end if;
4332 end;
4333 end if;
4334
4335 return;
4336
4337 else
4338 null;
4339 end if;
4340
4341 -- Another special case, an attribute denoting a procedure call
4342
4343 when
4344 N_Attribute_Reference =>
4345 if Is_Procedure_Attribute_Name (Attribute_Name (P)) then
4346 if P = Wrapped_Node then
4347 Store_Before_Actions_In_Scope (Ins_Actions);
4348 else
4349 Insert_List_Before_And_Analyze (P, Ins_Actions);
4350 end if;
4351
4352 return;
4353
4354 -- In the subexpression case, keep climbing
4355
4356 else
4357 null;
4358 end if;
4359
4360 -- A contract node should not belong to the tree
4361
4362 when N_Contract =>
4363 raise Program_Error;
4364
4365 -- For all other node types, keep climbing tree
4366
4367 when
4368 N_Abortable_Part |
4369 N_Accept_Alternative |
4370 N_Access_Definition |
4371 N_Access_Function_Definition |
4372 N_Access_Procedure_Definition |
4373 N_Access_To_Object_Definition |
4374 N_Aggregate |
4375 N_Allocator |
4376 N_Aspect_Specification |
4377 N_Case_Expression |
4378 N_Case_Statement_Alternative |
4379 N_Character_Literal |
4380 N_Compilation_Unit |
4381 N_Compilation_Unit_Aux |
4382 N_Component_Clause |
4383 N_Component_Declaration |
4384 N_Component_Definition |
4385 N_Component_List |
4386 N_Constrained_Array_Definition |
4387 N_Decimal_Fixed_Point_Definition |
4388 N_Defining_Character_Literal |
4389 N_Defining_Identifier |
4390 N_Defining_Operator_Symbol |
4391 N_Defining_Program_Unit_Name |
4392 N_Delay_Alternative |
4393 N_Delta_Constraint |
4394 N_Derived_Type_Definition |
4395 N_Designator |
4396 N_Digits_Constraint |
4397 N_Discriminant_Association |
4398 N_Discriminant_Specification |
4399 N_Empty |
4400 N_Entry_Body_Formal_Part |
4401 N_Entry_Call_Alternative |
4402 N_Entry_Declaration |
4403 N_Entry_Index_Specification |
4404 N_Enumeration_Type_Definition |
4405 N_Error |
4406 N_Exception_Handler |
4407 N_Expanded_Name |
4408 N_Explicit_Dereference |
4409 N_Extension_Aggregate |
4410 N_Floating_Point_Definition |
4411 N_Formal_Decimal_Fixed_Point_Definition |
4412 N_Formal_Derived_Type_Definition |
4413 N_Formal_Discrete_Type_Definition |
4414 N_Formal_Floating_Point_Definition |
4415 N_Formal_Modular_Type_Definition |
4416 N_Formal_Ordinary_Fixed_Point_Definition |
4417 N_Formal_Package_Declaration |
4418 N_Formal_Private_Type_Definition |
4419 N_Formal_Incomplete_Type_Definition |
4420 N_Formal_Signed_Integer_Type_Definition |
4421 N_Function_Call |
4422 N_Function_Specification |
4423 N_Generic_Association |
4424 N_Handled_Sequence_Of_Statements |
4425 N_Identifier |
4426 N_In |
4427 N_Index_Or_Discriminant_Constraint |
4428 N_Indexed_Component |
4429 N_Integer_Literal |
4430 N_Iterator_Specification |
4431 N_Itype_Reference |
4432 N_Label |
4433 N_Loop_Parameter_Specification |
4434 N_Mod_Clause |
4435 N_Modular_Type_Definition |
4436 N_Not_In |
4437 N_Null |
4438 N_Op_Abs |
4439 N_Op_Add |
4440 N_Op_And |
4441 N_Op_Concat |
4442 N_Op_Divide |
4443 N_Op_Eq |
4444 N_Op_Expon |
4445 N_Op_Ge |
4446 N_Op_Gt |
4447 N_Op_Le |
4448 N_Op_Lt |
4449 N_Op_Minus |
4450 N_Op_Mod |
4451 N_Op_Multiply |
4452 N_Op_Ne |
4453 N_Op_Not |
4454 N_Op_Or |
4455 N_Op_Plus |
4456 N_Op_Rem |
4457 N_Op_Rotate_Left |
4458 N_Op_Rotate_Right |
4459 N_Op_Shift_Left |
4460 N_Op_Shift_Right |
4461 N_Op_Shift_Right_Arithmetic |
4462 N_Op_Subtract |
4463 N_Op_Xor |
4464 N_Operator_Symbol |
4465 N_Ordinary_Fixed_Point_Definition |
4466 N_Others_Choice |
4467 N_Package_Specification |
4468 N_Parameter_Association |
4469 N_Parameter_Specification |
4470 N_Pop_Constraint_Error_Label |
4471 N_Pop_Program_Error_Label |
4472 N_Pop_Storage_Error_Label |
4473 N_Pragma_Argument_Association |
4474 N_Procedure_Specification |
4475 N_Protected_Definition |
4476 N_Push_Constraint_Error_Label |
4477 N_Push_Program_Error_Label |
4478 N_Push_Storage_Error_Label |
4479 N_Qualified_Expression |
4480 N_Quantified_Expression |
4481 N_Raise_Expression |
4482 N_Range |
4483 N_Range_Constraint |
4484 N_Real_Literal |
4485 N_Real_Range_Specification |
4486 N_Record_Definition |
4487 N_Reference |
4488 N_SCIL_Dispatch_Table_Tag_Init |
4489 N_SCIL_Dispatching_Call |
4490 N_SCIL_Membership_Test |
4491 N_Selected_Component |
4492 N_Signed_Integer_Type_Definition |
4493 N_Single_Protected_Declaration |
4494 N_Slice |
4495 N_String_Literal |
4496 N_Subtype_Indication |
4497 N_Subunit |
4498 N_Task_Definition |
4499 N_Terminate_Alternative |
4500 N_Triggering_Alternative |
4501 N_Type_Conversion |
4502 N_Unchecked_Expression |
4503 N_Unchecked_Type_Conversion |
4504 N_Unconstrained_Array_Definition |
4505 N_Unused_At_End |
4506 N_Unused_At_Start |
4507 N_Variant |
4508 N_Variant_Part |
4509 N_Validate_Unchecked_Conversion |
4510 N_With_Clause
4511 =>
4512 null;
4513
4514 end case;
4515
4516 -- If we fall through above tests, keep climbing tree
4517
4518 N := P;
4519
4520 if Nkind (Parent (N)) = N_Subunit then
4521
4522 -- This is the proper body corresponding to a stub. Insertion must
4523 -- be done at the point of the stub, which is in the declarative
4524 -- part of the parent unit.
4525
4526 P := Corresponding_Stub (Parent (N));
4527
4528 else
4529 P := Parent (N);
4530 end if;
4531 end loop;
4532 end Insert_Actions;
4533
4534 -- Version with check(s) suppressed
4535
4536 procedure Insert_Actions
4537 (Assoc_Node : Node_Id;
4538 Ins_Actions : List_Id;
4539 Suppress : Check_Id)
4540 is
4541 begin
4542 if Suppress = All_Checks then
4543 declare
4544 Sva : constant Suppress_Array := Scope_Suppress.Suppress;
4545 begin
4546 Scope_Suppress.Suppress := (others => True);
4547 Insert_Actions (Assoc_Node, Ins_Actions);
4548 Scope_Suppress.Suppress := Sva;
4549 end;
4550
4551 else
4552 declare
4553 Svg : constant Boolean := Scope_Suppress.Suppress (Suppress);
4554 begin
4555 Scope_Suppress.Suppress (Suppress) := True;
4556 Insert_Actions (Assoc_Node, Ins_Actions);
4557 Scope_Suppress.Suppress (Suppress) := Svg;
4558 end;
4559 end if;
4560 end Insert_Actions;
4561
4562 --------------------------
4563 -- Insert_Actions_After --
4564 --------------------------
4565
4566 procedure Insert_Actions_After
4567 (Assoc_Node : Node_Id;
4568 Ins_Actions : List_Id)
4569 is
4570 begin
4571 if Scope_Is_Transient and then Assoc_Node = Node_To_Be_Wrapped then
4572 Store_After_Actions_In_Scope (Ins_Actions);
4573 else
4574 Insert_List_After_And_Analyze (Assoc_Node, Ins_Actions);
4575 end if;
4576 end Insert_Actions_After;
4577
4578 ------------------------
4579 -- Insert_Declaration --
4580 ------------------------
4581
4582 procedure Insert_Declaration (N : Node_Id; Decl : Node_Id) is
4583 P : Node_Id;
4584
4585 begin
4586 pragma Assert (Nkind (N) in N_Subexpr);
4587
4588 -- Climb until we find a procedure or a package
4589
4590 P := N;
4591 loop
4592 pragma Assert (Present (Parent (P)));
4593 P := Parent (P);
4594
4595 if Is_List_Member (P) then
4596 exit when Nkind_In (Parent (P), N_Package_Specification,
4597 N_Subprogram_Body);
4598
4599 -- Special handling for handled sequence of statements, we must
4600 -- insert in the statements not the exception handlers!
4601
4602 if Nkind (Parent (P)) = N_Handled_Sequence_Of_Statements then
4603 P := First (Statements (Parent (P)));
4604 exit;
4605 end if;
4606 end if;
4607 end loop;
4608
4609 -- Now do the insertion
4610
4611 Insert_Before (P, Decl);
4612 Analyze (Decl);
4613 end Insert_Declaration;
4614
4615 ---------------------------------
4616 -- Insert_Library_Level_Action --
4617 ---------------------------------
4618
4619 procedure Insert_Library_Level_Action (N : Node_Id) is
4620 Aux : constant Node_Id := Aux_Decls_Node (Cunit (Main_Unit));
4621
4622 begin
4623 Push_Scope (Cunit_Entity (Main_Unit));
4624 -- ??? should this be Current_Sem_Unit instead of Main_Unit?
4625
4626 if No (Actions (Aux)) then
4627 Set_Actions (Aux, New_List (N));
4628 else
4629 Append (N, Actions (Aux));
4630 end if;
4631
4632 Analyze (N);
4633 Pop_Scope;
4634 end Insert_Library_Level_Action;
4635
4636 ----------------------------------
4637 -- Insert_Library_Level_Actions --
4638 ----------------------------------
4639
4640 procedure Insert_Library_Level_Actions (L : List_Id) is
4641 Aux : constant Node_Id := Aux_Decls_Node (Cunit (Main_Unit));
4642
4643 begin
4644 if Is_Non_Empty_List (L) then
4645 Push_Scope (Cunit_Entity (Main_Unit));
4646 -- ??? should this be Current_Sem_Unit instead of Main_Unit?
4647
4648 if No (Actions (Aux)) then
4649 Set_Actions (Aux, L);
4650 Analyze_List (L);
4651 else
4652 Insert_List_After_And_Analyze (Last (Actions (Aux)), L);
4653 end if;
4654
4655 Pop_Scope;
4656 end if;
4657 end Insert_Library_Level_Actions;
4658
4659 ----------------------
4660 -- Inside_Init_Proc --
4661 ----------------------
4662
4663 function Inside_Init_Proc return Boolean is
4664 S : Entity_Id;
4665
4666 begin
4667 S := Current_Scope;
4668 while Present (S) and then S /= Standard_Standard loop
4669 if Is_Init_Proc (S) then
4670 return True;
4671 else
4672 S := Scope (S);
4673 end if;
4674 end loop;
4675
4676 return False;
4677 end Inside_Init_Proc;
4678
4679 ----------------------------
4680 -- Is_All_Null_Statements --
4681 ----------------------------
4682
4683 function Is_All_Null_Statements (L : List_Id) return Boolean is
4684 Stm : Node_Id;
4685
4686 begin
4687 Stm := First (L);
4688 while Present (Stm) loop
4689 if Nkind (Stm) /= N_Null_Statement then
4690 return False;
4691 end if;
4692
4693 Next (Stm);
4694 end loop;
4695
4696 return True;
4697 end Is_All_Null_Statements;
4698
4699 --------------------------------------------------
4700 -- Is_Displacement_Of_Object_Or_Function_Result --
4701 --------------------------------------------------
4702
4703 function Is_Displacement_Of_Object_Or_Function_Result
4704 (Obj_Id : Entity_Id) return Boolean
4705 is
4706 function Is_Controlled_Function_Call (N : Node_Id) return Boolean;
4707 -- Determine if particular node denotes a controlled function call. The
4708 -- call may have been heavily expanded.
4709
4710 function Is_Displace_Call (N : Node_Id) return Boolean;
4711 -- Determine whether a particular node is a call to Ada.Tags.Displace.
4712 -- The call might be nested within other actions such as conversions.
4713
4714 function Is_Source_Object (N : Node_Id) return Boolean;
4715 -- Determine whether a particular node denotes a source object
4716
4717 ---------------------------------
4718 -- Is_Controlled_Function_Call --
4719 ---------------------------------
4720
4721 function Is_Controlled_Function_Call (N : Node_Id) return Boolean is
4722 Expr : Node_Id := Original_Node (N);
4723
4724 begin
4725 -- When a function call appears in Object.Operation format, the
4726 -- original representation has several possible forms depending on
4727 -- the availability and form of actual parameters:
4728
4729 -- Obj.Func N_Selected_Component
4730 -- Obj.Func (Actual) N_Indexed_Component
4731 -- Obj.Func (Formal => Actual) N_Function_Call, whose Name is an
4732 -- N_Selected_Component
4733
4734 case Nkind (Expr) is
4735 when N_Function_Call =>
4736 Expr := Name (Expr);
4737
4738 -- Check for "Obj.Func (Formal => Actual)" case
4739
4740 if Nkind (Expr) = N_Selected_Component then
4741 Expr := Selector_Name (Expr);
4742 end if;
4743
4744 -- "Obj.Func (Actual)" case
4745
4746 when N_Indexed_Component =>
4747 Expr := Prefix (Expr);
4748
4749 if Nkind (Expr) = N_Selected_Component then
4750 Expr := Selector_Name (Expr);
4751 end if;
4752
4753 -- "Obj.Func" case
4754
4755 when N_Selected_Component =>
4756 Expr := Selector_Name (Expr);
4757
4758 when others => null;
4759 end case;
4760
4761 return
4762 Nkind_In (Expr, N_Expanded_Name, N_Identifier)
4763 and then Ekind (Entity (Expr)) = E_Function
4764 and then Needs_Finalization (Etype (Entity (Expr)));
4765 end Is_Controlled_Function_Call;
4766
4767 ----------------------
4768 -- Is_Displace_Call --
4769 ----------------------
4770
4771 function Is_Displace_Call (N : Node_Id) return Boolean is
4772 Call : Node_Id := N;
4773
4774 begin
4775 -- Strip various actions which may precede a call to Displace
4776
4777 loop
4778 if Nkind (Call) = N_Explicit_Dereference then
4779 Call := Prefix (Call);
4780
4781 elsif Nkind_In (Call, N_Type_Conversion,
4782 N_Unchecked_Type_Conversion)
4783 then
4784 Call := Expression (Call);
4785
4786 else
4787 exit;
4788 end if;
4789 end loop;
4790
4791 return
4792 Present (Call)
4793 and then Nkind (Call) = N_Function_Call
4794 and then Is_RTE (Entity (Name (Call)), RE_Displace);
4795 end Is_Displace_Call;
4796
4797 ----------------------
4798 -- Is_Source_Object --
4799 ----------------------
4800
4801 function Is_Source_Object (N : Node_Id) return Boolean is
4802 begin
4803 return
4804 Present (N)
4805 and then Nkind (N) in N_Has_Entity
4806 and then Is_Object (Entity (N))
4807 and then Comes_From_Source (N);
4808 end Is_Source_Object;
4809
4810 -- Local variables
4811
4812 Decl : constant Node_Id := Parent (Obj_Id);
4813 Obj_Typ : constant Entity_Id := Base_Type (Etype (Obj_Id));
4814 Orig_Decl : constant Node_Id := Original_Node (Decl);
4815
4816 -- Start of processing for Is_Displacement_Of_Object_Or_Function_Result
4817
4818 begin
4819 -- Case 1:
4820
4821 -- Obj : CW_Type := Function_Call (...);
4822
4823 -- rewritten into:
4824
4825 -- Tmp : ... := Function_Call (...)'reference;
4826 -- Obj : CW_Type renames (... Ada.Tags.Displace (Tmp));
4827
4828 -- where the return type of the function and the class-wide type require
4829 -- dispatch table pointer displacement.
4830
4831 -- Case 2:
4832
4833 -- Obj : CW_Type := Src_Obj;
4834
4835 -- rewritten into:
4836
4837 -- Obj : CW_Type renames (... Ada.Tags.Displace (Src_Obj));
4838
4839 -- where the type of the source object and the class-wide type require
4840 -- dispatch table pointer displacement.
4841
4842 return
4843 Nkind (Decl) = N_Object_Renaming_Declaration
4844 and then Nkind (Orig_Decl) = N_Object_Declaration
4845 and then Comes_From_Source (Orig_Decl)
4846 and then Is_Class_Wide_Type (Obj_Typ)
4847 and then Is_Displace_Call (Renamed_Object (Obj_Id))
4848 and then
4849 (Is_Controlled_Function_Call (Expression (Orig_Decl))
4850 or else Is_Source_Object (Expression (Orig_Decl)));
4851 end Is_Displacement_Of_Object_Or_Function_Result;
4852
4853 ------------------------------
4854 -- Is_Finalizable_Transient --
4855 ------------------------------
4856
4857 function Is_Finalizable_Transient
4858 (Decl : Node_Id;
4859 Rel_Node : Node_Id) return Boolean
4860 is
4861 Obj_Id : constant Entity_Id := Defining_Identifier (Decl);
4862 Obj_Typ : constant Entity_Id := Base_Type (Etype (Obj_Id));
4863
4864 function Initialized_By_Access (Trans_Id : Entity_Id) return Boolean;
4865 -- Determine whether transient object Trans_Id is initialized either
4866 -- by a function call which returns an access type or simply renames
4867 -- another pointer.
4868
4869 function Initialized_By_Aliased_BIP_Func_Call
4870 (Trans_Id : Entity_Id) return Boolean;
4871 -- Determine whether transient object Trans_Id is initialized by a
4872 -- build-in-place function call where the BIPalloc parameter is of
4873 -- value 1 and BIPaccess is not null. This case creates an aliasing
4874 -- between the returned value and the value denoted by BIPaccess.
4875
4876 function Is_Aliased
4877 (Trans_Id : Entity_Id;
4878 First_Stmt : Node_Id) return Boolean;
4879 -- Determine whether transient object Trans_Id has been renamed or
4880 -- aliased through 'reference in the statement list starting from
4881 -- First_Stmt.
4882
4883 function Is_Allocated (Trans_Id : Entity_Id) return Boolean;
4884 -- Determine whether transient object Trans_Id is allocated on the heap
4885
4886 function Is_Iterated_Container
4887 (Trans_Id : Entity_Id;
4888 First_Stmt : Node_Id) return Boolean;
4889 -- Determine whether transient object Trans_Id denotes a container which
4890 -- is in the process of being iterated in the statement list starting
4891 -- from First_Stmt.
4892
4893 ---------------------------
4894 -- Initialized_By_Access --
4895 ---------------------------
4896
4897 function Initialized_By_Access (Trans_Id : Entity_Id) return Boolean is
4898 Expr : constant Node_Id := Expression (Parent (Trans_Id));
4899
4900 begin
4901 return
4902 Present (Expr)
4903 and then Nkind (Expr) /= N_Reference
4904 and then Is_Access_Type (Etype (Expr));
4905 end Initialized_By_Access;
4906
4907 ------------------------------------------
4908 -- Initialized_By_Aliased_BIP_Func_Call --
4909 ------------------------------------------
4910
4911 function Initialized_By_Aliased_BIP_Func_Call
4912 (Trans_Id : Entity_Id) return Boolean
4913 is
4914 Call : Node_Id := Expression (Parent (Trans_Id));
4915
4916 begin
4917 -- Build-in-place calls usually appear in 'reference format
4918
4919 if Nkind (Call) = N_Reference then
4920 Call := Prefix (Call);
4921 end if;
4922
4923 if Is_Build_In_Place_Function_Call (Call) then
4924 declare
4925 Access_Nam : Name_Id := No_Name;
4926 Access_OK : Boolean := False;
4927 Actual : Node_Id;
4928 Alloc_Nam : Name_Id := No_Name;
4929 Alloc_OK : Boolean := False;
4930 Formal : Node_Id;
4931 Func_Id : Entity_Id;
4932 Param : Node_Id;
4933
4934 begin
4935 -- Examine all parameter associations of the function call
4936
4937 Param := First (Parameter_Associations (Call));
4938 while Present (Param) loop
4939 if Nkind (Param) = N_Parameter_Association
4940 and then Nkind (Selector_Name (Param)) = N_Identifier
4941 then
4942 Actual := Explicit_Actual_Parameter (Param);
4943 Formal := Selector_Name (Param);
4944
4945 -- Construct the names of formals BIPaccess and BIPalloc
4946 -- using the function name retrieved from an arbitrary
4947 -- formal.
4948
4949 if Access_Nam = No_Name
4950 and then Alloc_Nam = No_Name
4951 and then Present (Entity (Formal))
4952 then
4953 Func_Id := Scope (Entity (Formal));
4954
4955 Access_Nam :=
4956 New_External_Name (Chars (Func_Id),
4957 BIP_Formal_Suffix (BIP_Object_Access));
4958
4959 Alloc_Nam :=
4960 New_External_Name (Chars (Func_Id),
4961 BIP_Formal_Suffix (BIP_Alloc_Form));
4962 end if;
4963
4964 -- A match for BIPaccess => Temp has been found
4965
4966 if Chars (Formal) = Access_Nam
4967 and then Nkind (Actual) /= N_Null
4968 then
4969 Access_OK := True;
4970 end if;
4971
4972 -- A match for BIPalloc => 1 has been found
4973
4974 if Chars (Formal) = Alloc_Nam
4975 and then Nkind (Actual) = N_Integer_Literal
4976 and then Intval (Actual) = Uint_1
4977 then
4978 Alloc_OK := True;
4979 end if;
4980 end if;
4981
4982 Next (Param);
4983 end loop;
4984
4985 return Access_OK and Alloc_OK;
4986 end;
4987 end if;
4988
4989 return False;
4990 end Initialized_By_Aliased_BIP_Func_Call;
4991
4992 ----------------
4993 -- Is_Aliased --
4994 ----------------
4995
4996 function Is_Aliased
4997 (Trans_Id : Entity_Id;
4998 First_Stmt : Node_Id) return Boolean
4999 is
5000 function Find_Renamed_Object (Ren_Decl : Node_Id) return Entity_Id;
5001 -- Given an object renaming declaration, retrieve the entity of the
5002 -- renamed name. Return Empty if the renamed name is anything other
5003 -- than a variable or a constant.
5004
5005 -------------------------
5006 -- Find_Renamed_Object --
5007 -------------------------
5008
5009 function Find_Renamed_Object (Ren_Decl : Node_Id) return Entity_Id is
5010 Ren_Obj : Node_Id := Empty;
5011
5012 function Find_Object (N : Node_Id) return Traverse_Result;
5013 -- Try to detect an object which is either a constant or a
5014 -- variable.
5015
5016 -----------------
5017 -- Find_Object --
5018 -----------------
5019
5020 function Find_Object (N : Node_Id) return Traverse_Result is
5021 begin
5022 -- Stop the search once a constant or a variable has been
5023 -- detected.
5024
5025 if Nkind (N) = N_Identifier
5026 and then Present (Entity (N))
5027 and then Ekind_In (Entity (N), E_Constant, E_Variable)
5028 then
5029 Ren_Obj := Entity (N);
5030 return Abandon;
5031 end if;
5032
5033 return OK;
5034 end Find_Object;
5035
5036 procedure Search is new Traverse_Proc (Find_Object);
5037
5038 -- Local variables
5039
5040 Typ : constant Entity_Id := Etype (Defining_Identifier (Ren_Decl));
5041
5042 -- Start of processing for Find_Renamed_Object
5043
5044 begin
5045 -- Actions related to dispatching calls may appear as renamings of
5046 -- tags. Do not process this type of renaming because it does not
5047 -- use the actual value of the object.
5048
5049 if not Is_RTE (Typ, RE_Tag_Ptr) then
5050 Search (Name (Ren_Decl));
5051 end if;
5052
5053 return Ren_Obj;
5054 end Find_Renamed_Object;
5055
5056 -- Local variables
5057
5058 Expr : Node_Id;
5059 Ren_Obj : Entity_Id;
5060 Stmt : Node_Id;
5061
5062 -- Start of processing for Is_Aliased
5063
5064 begin
5065 -- A controlled transient object is not considered aliased when it
5066 -- appears inside an expression_with_actions node even when there are
5067 -- explicit aliases of it:
5068
5069 -- do
5070 -- Trans_Id : Ctrl_Typ ...; -- controlled transient object
5071 -- Alias : ... := Trans_Id; -- object is aliased
5072 -- Val : constant Boolean :=
5073 -- ... Alias ...; -- aliasing ends
5074 -- <finalize Trans_Id> -- object safe to finalize
5075 -- in Val end;
5076
5077 -- Expansion ensures that all aliases are encapsulated in the actions
5078 -- list and do not leak to the expression by forcing the evaluation
5079 -- of the expression.
5080
5081 if Nkind (Rel_Node) = N_Expression_With_Actions then
5082 return False;
5083
5084 -- Otherwise examine the statements after the controlled transient
5085 -- object and look for various forms of aliasing.
5086
5087 else
5088 Stmt := First_Stmt;
5089 while Present (Stmt) loop
5090 if Nkind (Stmt) = N_Object_Declaration then
5091 Expr := Expression (Stmt);
5092
5093 -- Aliasing of the form:
5094 -- Obj : ... := Trans_Id'reference;
5095
5096 if Present (Expr)
5097 and then Nkind (Expr) = N_Reference
5098 and then Nkind (Prefix (Expr)) = N_Identifier
5099 and then Entity (Prefix (Expr)) = Trans_Id
5100 then
5101 return True;
5102 end if;
5103
5104 elsif Nkind (Stmt) = N_Object_Renaming_Declaration then
5105 Ren_Obj := Find_Renamed_Object (Stmt);
5106
5107 -- Aliasing of the form:
5108 -- Obj : ... renames ... Trans_Id ...;
5109
5110 if Present (Ren_Obj) and then Ren_Obj = Trans_Id then
5111 return True;
5112 end if;
5113 end if;
5114
5115 Next (Stmt);
5116 end loop;
5117
5118 return False;
5119 end if;
5120 end Is_Aliased;
5121
5122 ------------------
5123 -- Is_Allocated --
5124 ------------------
5125
5126 function Is_Allocated (Trans_Id : Entity_Id) return Boolean is
5127 Expr : constant Node_Id := Expression (Parent (Trans_Id));
5128 begin
5129 return
5130 Is_Access_Type (Etype (Trans_Id))
5131 and then Present (Expr)
5132 and then Nkind (Expr) = N_Allocator;
5133 end Is_Allocated;
5134
5135 ---------------------------
5136 -- Is_Iterated_Container --
5137 ---------------------------
5138
5139 function Is_Iterated_Container
5140 (Trans_Id : Entity_Id;
5141 First_Stmt : Node_Id) return Boolean
5142 is
5143 Aspect : Node_Id;
5144 Call : Node_Id;
5145 Iter : Entity_Id;
5146 Param : Node_Id;
5147 Stmt : Node_Id;
5148 Typ : Entity_Id;
5149
5150 begin
5151 -- It is not possible to iterate over containers in non-Ada 2012 code
5152
5153 if Ada_Version < Ada_2012 then
5154 return False;
5155 end if;
5156
5157 Typ := Etype (Trans_Id);
5158
5159 -- Handle access type created for secondary stack use
5160
5161 if Is_Access_Type (Typ) then
5162 Typ := Designated_Type (Typ);
5163 end if;
5164
5165 -- Look for aspect Default_Iterator. It may be part of a type
5166 -- declaration for a container, or inherited from a base type
5167 -- or parent type.
5168
5169 Aspect := Find_Value_Of_Aspect (Typ, Aspect_Default_Iterator);
5170
5171 if Present (Aspect) then
5172 Iter := Entity (Aspect);
5173
5174 -- Examine the statements following the container object and
5175 -- look for a call to the default iterate routine where the
5176 -- first parameter is the transient. Such a call appears as:
5177
5178 -- It : Access_To_CW_Iterator :=
5179 -- Iterate (Tran_Id.all, ...)'reference;
5180
5181 Stmt := First_Stmt;
5182 while Present (Stmt) loop
5183
5184 -- Detect an object declaration which is initialized by a
5185 -- secondary stack function call.
5186
5187 if Nkind (Stmt) = N_Object_Declaration
5188 and then Present (Expression (Stmt))
5189 and then Nkind (Expression (Stmt)) = N_Reference
5190 and then Nkind (Prefix (Expression (Stmt))) = N_Function_Call
5191 then
5192 Call := Prefix (Expression (Stmt));
5193
5194 -- The call must invoke the default iterate routine of
5195 -- the container and the transient object must appear as
5196 -- the first actual parameter. Skip any calls whose names
5197 -- are not entities.
5198
5199 if Is_Entity_Name (Name (Call))
5200 and then Entity (Name (Call)) = Iter
5201 and then Present (Parameter_Associations (Call))
5202 then
5203 Param := First (Parameter_Associations (Call));
5204
5205 if Nkind (Param) = N_Explicit_Dereference
5206 and then Entity (Prefix (Param)) = Trans_Id
5207 then
5208 return True;
5209 end if;
5210 end if;
5211 end if;
5212
5213 Next (Stmt);
5214 end loop;
5215 end if;
5216
5217 return False;
5218 end Is_Iterated_Container;
5219
5220 -- Local variables
5221
5222 Desig : Entity_Id := Obj_Typ;
5223
5224 -- Start of processing for Is_Finalizable_Transient
5225
5226 begin
5227 -- Handle access types
5228
5229 if Is_Access_Type (Desig) then
5230 Desig := Available_View (Designated_Type (Desig));
5231 end if;
5232
5233 return
5234 Ekind_In (Obj_Id, E_Constant, E_Variable)
5235 and then Needs_Finalization (Desig)
5236 and then Requires_Transient_Scope (Desig)
5237 and then Nkind (Rel_Node) /= N_Simple_Return_Statement
5238
5239 -- Do not consider renamed or 'reference-d transient objects because
5240 -- the act of renaming extends the object's lifetime.
5241
5242 and then not Is_Aliased (Obj_Id, Decl)
5243
5244 -- Do not consider transient objects allocated on the heap since
5245 -- they are attached to a finalization master.
5246
5247 and then not Is_Allocated (Obj_Id)
5248
5249 -- If the transient object is a pointer, check that it is not
5250 -- initialized by a function that returns a pointer or acts as a
5251 -- renaming of another pointer.
5252
5253 and then
5254 (not Is_Access_Type (Obj_Typ)
5255 or else not Initialized_By_Access (Obj_Id))
5256
5257 -- Do not consider transient objects which act as indirect aliases
5258 -- of build-in-place function results.
5259
5260 and then not Initialized_By_Aliased_BIP_Func_Call (Obj_Id)
5261
5262 -- Do not consider conversions of tags to class-wide types
5263
5264 and then not Is_Tag_To_Class_Wide_Conversion (Obj_Id)
5265
5266 -- Do not consider iterators because those are treated as normal
5267 -- controlled objects and are processed by the usual finalization
5268 -- machinery. This avoids the double finalization of an iterator.
5269
5270 and then not Is_Iterator (Desig)
5271
5272 -- Do not consider containers in the context of iterator loops. Such
5273 -- transient objects must exist for as long as the loop is around,
5274 -- otherwise any operation carried out by the iterator will fail.
5275
5276 and then not Is_Iterated_Container (Obj_Id, Decl);
5277 end Is_Finalizable_Transient;
5278
5279 ---------------------------------
5280 -- Is_Fully_Repped_Tagged_Type --
5281 ---------------------------------
5282
5283 function Is_Fully_Repped_Tagged_Type (T : Entity_Id) return Boolean is
5284 U : constant Entity_Id := Underlying_Type (T);
5285 Comp : Entity_Id;
5286
5287 begin
5288 if No (U) or else not Is_Tagged_Type (U) then
5289 return False;
5290 elsif Has_Discriminants (U) then
5291 return False;
5292 elsif not Has_Specified_Layout (U) then
5293 return False;
5294 end if;
5295
5296 -- Here we have a tagged type, see if it has any unlayed out fields
5297 -- other than a possible tag and parent fields. If so, we return False.
5298
5299 Comp := First_Component (U);
5300 while Present (Comp) loop
5301 if not Is_Tag (Comp)
5302 and then Chars (Comp) /= Name_uParent
5303 and then No (Component_Clause (Comp))
5304 then
5305 return False;
5306 else
5307 Next_Component (Comp);
5308 end if;
5309 end loop;
5310
5311 -- All components are layed out
5312
5313 return True;
5314 end Is_Fully_Repped_Tagged_Type;
5315
5316 ----------------------------------
5317 -- Is_Library_Level_Tagged_Type --
5318 ----------------------------------
5319
5320 function Is_Library_Level_Tagged_Type (Typ : Entity_Id) return Boolean is
5321 begin
5322 return Is_Tagged_Type (Typ) and then Is_Library_Level_Entity (Typ);
5323 end Is_Library_Level_Tagged_Type;
5324
5325 --------------------------
5326 -- Is_Non_BIP_Func_Call --
5327 --------------------------
5328
5329 function Is_Non_BIP_Func_Call (Expr : Node_Id) return Boolean is
5330 begin
5331 -- The expected call is of the format
5332 --
5333 -- Func_Call'reference
5334
5335 return
5336 Nkind (Expr) = N_Reference
5337 and then Nkind (Prefix (Expr)) = N_Function_Call
5338 and then not Is_Build_In_Place_Function_Call (Prefix (Expr));
5339 end Is_Non_BIP_Func_Call;
5340
5341 ------------------------------------
5342 -- Is_Object_Access_BIP_Func_Call --
5343 ------------------------------------
5344
5345 function Is_Object_Access_BIP_Func_Call
5346 (Expr : Node_Id;
5347 Obj_Id : Entity_Id) return Boolean
5348 is
5349 Access_Nam : Name_Id := No_Name;
5350 Actual : Node_Id;
5351 Call : Node_Id;
5352 Formal : Node_Id;
5353 Param : Node_Id;
5354
5355 begin
5356 -- Build-in-place calls usually appear in 'reference format. Note that
5357 -- the accessibility check machinery may add an extra 'reference due to
5358 -- side effect removal.
5359
5360 Call := Expr;
5361 while Nkind (Call) = N_Reference loop
5362 Call := Prefix (Call);
5363 end loop;
5364
5365 if Nkind_In (Call, N_Qualified_Expression,
5366 N_Unchecked_Type_Conversion)
5367 then
5368 Call := Expression (Call);
5369 end if;
5370
5371 if Is_Build_In_Place_Function_Call (Call) then
5372
5373 -- Examine all parameter associations of the function call
5374
5375 Param := First (Parameter_Associations (Call));
5376 while Present (Param) loop
5377 if Nkind (Param) = N_Parameter_Association
5378 and then Nkind (Selector_Name (Param)) = N_Identifier
5379 then
5380 Formal := Selector_Name (Param);
5381 Actual := Explicit_Actual_Parameter (Param);
5382
5383 -- Construct the name of formal BIPaccess. It is much easier to
5384 -- extract the name of the function using an arbitrary formal's
5385 -- scope rather than the Name field of Call.
5386
5387 if Access_Nam = No_Name and then Present (Entity (Formal)) then
5388 Access_Nam :=
5389 New_External_Name
5390 (Chars (Scope (Entity (Formal))),
5391 BIP_Formal_Suffix (BIP_Object_Access));
5392 end if;
5393
5394 -- A match for BIPaccess => Obj_Id'Unrestricted_Access has been
5395 -- found.
5396
5397 if Chars (Formal) = Access_Nam
5398 and then Nkind (Actual) = N_Attribute_Reference
5399 and then Attribute_Name (Actual) = Name_Unrestricted_Access
5400 and then Nkind (Prefix (Actual)) = N_Identifier
5401 and then Entity (Prefix (Actual)) = Obj_Id
5402 then
5403 return True;
5404 end if;
5405 end if;
5406
5407 Next (Param);
5408 end loop;
5409 end if;
5410
5411 return False;
5412 end Is_Object_Access_BIP_Func_Call;
5413
5414 ----------------------------------
5415 -- Is_Possibly_Unaligned_Object --
5416 ----------------------------------
5417
5418 function Is_Possibly_Unaligned_Object (N : Node_Id) return Boolean is
5419 T : constant Entity_Id := Etype (N);
5420
5421 begin
5422 -- If renamed object, apply test to underlying object
5423
5424 if Is_Entity_Name (N)
5425 and then Is_Object (Entity (N))
5426 and then Present (Renamed_Object (Entity (N)))
5427 then
5428 return Is_Possibly_Unaligned_Object (Renamed_Object (Entity (N)));
5429 end if;
5430
5431 -- Tagged and controlled types and aliased types are always aligned, as
5432 -- are concurrent types.
5433
5434 if Is_Aliased (T)
5435 or else Has_Controlled_Component (T)
5436 or else Is_Concurrent_Type (T)
5437 or else Is_Tagged_Type (T)
5438 or else Is_Controlled (T)
5439 then
5440 return False;
5441 end if;
5442
5443 -- If this is an element of a packed array, may be unaligned
5444
5445 if Is_Ref_To_Bit_Packed_Array (N) then
5446 return True;
5447 end if;
5448
5449 -- Case of indexed component reference: test whether prefix is unaligned
5450
5451 if Nkind (N) = N_Indexed_Component then
5452 return Is_Possibly_Unaligned_Object (Prefix (N));
5453
5454 -- Case of selected component reference
5455
5456 elsif Nkind (N) = N_Selected_Component then
5457 declare
5458 P : constant Node_Id := Prefix (N);
5459 C : constant Entity_Id := Entity (Selector_Name (N));
5460 M : Nat;
5461 S : Nat;
5462
5463 begin
5464 -- If component reference is for an array with non-static bounds,
5465 -- then it is always aligned: we can only process unaligned arrays
5466 -- with static bounds (more precisely compile time known bounds).
5467
5468 if Is_Array_Type (T)
5469 and then not Compile_Time_Known_Bounds (T)
5470 then
5471 return False;
5472 end if;
5473
5474 -- If component is aliased, it is definitely properly aligned
5475
5476 if Is_Aliased (C) then
5477 return False;
5478 end if;
5479
5480 -- If component is for a type implemented as a scalar, and the
5481 -- record is packed, and the component is other than the first
5482 -- component of the record, then the component may be unaligned.
5483
5484 if Is_Packed (Etype (P))
5485 and then Represented_As_Scalar (Etype (C))
5486 and then First_Entity (Scope (C)) /= C
5487 then
5488 return True;
5489 end if;
5490
5491 -- Compute maximum possible alignment for T
5492
5493 -- If alignment is known, then that settles things
5494
5495 if Known_Alignment (T) then
5496 M := UI_To_Int (Alignment (T));
5497
5498 -- If alignment is not known, tentatively set max alignment
5499
5500 else
5501 M := Ttypes.Maximum_Alignment;
5502
5503 -- We can reduce this if the Esize is known since the default
5504 -- alignment will never be more than the smallest power of 2
5505 -- that does not exceed this Esize value.
5506
5507 if Known_Esize (T) then
5508 S := UI_To_Int (Esize (T));
5509
5510 while (M / 2) >= S loop
5511 M := M / 2;
5512 end loop;
5513 end if;
5514 end if;
5515
5516 -- The following code is historical, it used to be present but it
5517 -- is too cautious, because the front-end does not know the proper
5518 -- default alignments for the target. Also, if the alignment is
5519 -- not known, the front end can't know in any case. If a copy is
5520 -- needed, the back-end will take care of it. This whole section
5521 -- including this comment can be removed later ???
5522
5523 -- If the component reference is for a record that has a specified
5524 -- alignment, and we either know it is too small, or cannot tell,
5525 -- then the component may be unaligned.
5526
5527 -- What is the following commented out code ???
5528
5529 -- if Known_Alignment (Etype (P))
5530 -- and then Alignment (Etype (P)) < Ttypes.Maximum_Alignment
5531 -- and then M > Alignment (Etype (P))
5532 -- then
5533 -- return True;
5534 -- end if;
5535
5536 -- Case of component clause present which may specify an
5537 -- unaligned position.
5538
5539 if Present (Component_Clause (C)) then
5540
5541 -- Otherwise we can do a test to make sure that the actual
5542 -- start position in the record, and the length, are both
5543 -- consistent with the required alignment. If not, we know
5544 -- that we are unaligned.
5545
5546 declare
5547 Align_In_Bits : constant Nat := M * System_Storage_Unit;
5548 begin
5549 if Component_Bit_Offset (C) mod Align_In_Bits /= 0
5550 or else Esize (C) mod Align_In_Bits /= 0
5551 then
5552 return True;
5553 end if;
5554 end;
5555 end if;
5556
5557 -- Otherwise, for a component reference, test prefix
5558
5559 return Is_Possibly_Unaligned_Object (P);
5560 end;
5561
5562 -- If not a component reference, must be aligned
5563
5564 else
5565 return False;
5566 end if;
5567 end Is_Possibly_Unaligned_Object;
5568
5569 ---------------------------------
5570 -- Is_Possibly_Unaligned_Slice --
5571 ---------------------------------
5572
5573 function Is_Possibly_Unaligned_Slice (N : Node_Id) return Boolean is
5574 begin
5575 -- Go to renamed object
5576
5577 if Is_Entity_Name (N)
5578 and then Is_Object (Entity (N))
5579 and then Present (Renamed_Object (Entity (N)))
5580 then
5581 return Is_Possibly_Unaligned_Slice (Renamed_Object (Entity (N)));
5582 end if;
5583
5584 -- The reference must be a slice
5585
5586 if Nkind (N) /= N_Slice then
5587 return False;
5588 end if;
5589
5590 -- We only need to worry if the target has strict alignment
5591
5592 if not Target_Strict_Alignment then
5593 return False;
5594 end if;
5595
5596 -- If it is a slice, then look at the array type being sliced
5597
5598 declare
5599 Sarr : constant Node_Id := Prefix (N);
5600 -- Prefix of the slice, i.e. the array being sliced
5601
5602 Styp : constant Entity_Id := Etype (Prefix (N));
5603 -- Type of the array being sliced
5604
5605 Pref : Node_Id;
5606 Ptyp : Entity_Id;
5607
5608 begin
5609 -- The problems arise if the array object that is being sliced
5610 -- is a component of a record or array, and we cannot guarantee
5611 -- the alignment of the array within its containing object.
5612
5613 -- To investigate this, we look at successive prefixes to see
5614 -- if we have a worrisome indexed or selected component.
5615
5616 Pref := Sarr;
5617 loop
5618 -- Case of array is part of an indexed component reference
5619
5620 if Nkind (Pref) = N_Indexed_Component then
5621 Ptyp := Etype (Prefix (Pref));
5622
5623 -- The only problematic case is when the array is packed, in
5624 -- which case we really know nothing about the alignment of
5625 -- individual components.
5626
5627 if Is_Bit_Packed_Array (Ptyp) then
5628 return True;
5629 end if;
5630
5631 -- Case of array is part of a selected component reference
5632
5633 elsif Nkind (Pref) = N_Selected_Component then
5634 Ptyp := Etype (Prefix (Pref));
5635
5636 -- We are definitely in trouble if the record in question
5637 -- has an alignment, and either we know this alignment is
5638 -- inconsistent with the alignment of the slice, or we don't
5639 -- know what the alignment of the slice should be.
5640
5641 if Known_Alignment (Ptyp)
5642 and then (Unknown_Alignment (Styp)
5643 or else Alignment (Styp) > Alignment (Ptyp))
5644 then
5645 return True;
5646 end if;
5647
5648 -- We are in potential trouble if the record type is packed.
5649 -- We could special case when we know that the array is the
5650 -- first component, but that's not such a simple case ???
5651
5652 if Is_Packed (Ptyp) then
5653 return True;
5654 end if;
5655
5656 -- We are in trouble if there is a component clause, and
5657 -- either we do not know the alignment of the slice, or
5658 -- the alignment of the slice is inconsistent with the
5659 -- bit position specified by the component clause.
5660
5661 declare
5662 Field : constant Entity_Id := Entity (Selector_Name (Pref));
5663 begin
5664 if Present (Component_Clause (Field))
5665 and then
5666 (Unknown_Alignment (Styp)
5667 or else
5668 (Component_Bit_Offset (Field) mod
5669 (System_Storage_Unit * Alignment (Styp))) /= 0)
5670 then
5671 return True;
5672 end if;
5673 end;
5674
5675 -- For cases other than selected or indexed components we know we
5676 -- are OK, since no issues arise over alignment.
5677
5678 else
5679 return False;
5680 end if;
5681
5682 -- We processed an indexed component or selected component
5683 -- reference that looked safe, so keep checking prefixes.
5684
5685 Pref := Prefix (Pref);
5686 end loop;
5687 end;
5688 end Is_Possibly_Unaligned_Slice;
5689
5690 -------------------------------
5691 -- Is_Related_To_Func_Return --
5692 -------------------------------
5693
5694 function Is_Related_To_Func_Return (Id : Entity_Id) return Boolean is
5695 Expr : constant Node_Id := Related_Expression (Id);
5696 begin
5697 return
5698 Present (Expr)
5699 and then Nkind (Expr) = N_Explicit_Dereference
5700 and then Nkind (Parent (Expr)) = N_Simple_Return_Statement;
5701 end Is_Related_To_Func_Return;
5702
5703 --------------------------------
5704 -- Is_Ref_To_Bit_Packed_Array --
5705 --------------------------------
5706
5707 function Is_Ref_To_Bit_Packed_Array (N : Node_Id) return Boolean is
5708 Result : Boolean;
5709 Expr : Node_Id;
5710
5711 begin
5712 if Is_Entity_Name (N)
5713 and then Is_Object (Entity (N))
5714 and then Present (Renamed_Object (Entity (N)))
5715 then
5716 return Is_Ref_To_Bit_Packed_Array (Renamed_Object (Entity (N)));
5717 end if;
5718
5719 if Nkind_In (N, N_Indexed_Component, N_Selected_Component) then
5720 if Is_Bit_Packed_Array (Etype (Prefix (N))) then
5721 Result := True;
5722 else
5723 Result := Is_Ref_To_Bit_Packed_Array (Prefix (N));
5724 end if;
5725
5726 if Result and then Nkind (N) = N_Indexed_Component then
5727 Expr := First (Expressions (N));
5728 while Present (Expr) loop
5729 Force_Evaluation (Expr);
5730 Next (Expr);
5731 end loop;
5732 end if;
5733
5734 return Result;
5735
5736 else
5737 return False;
5738 end if;
5739 end Is_Ref_To_Bit_Packed_Array;
5740
5741 --------------------------------
5742 -- Is_Ref_To_Bit_Packed_Slice --
5743 --------------------------------
5744
5745 function Is_Ref_To_Bit_Packed_Slice (N : Node_Id) return Boolean is
5746 begin
5747 if Nkind (N) = N_Type_Conversion then
5748 return Is_Ref_To_Bit_Packed_Slice (Expression (N));
5749
5750 elsif Is_Entity_Name (N)
5751 and then Is_Object (Entity (N))
5752 and then Present (Renamed_Object (Entity (N)))
5753 then
5754 return Is_Ref_To_Bit_Packed_Slice (Renamed_Object (Entity (N)));
5755
5756 elsif Nkind (N) = N_Slice
5757 and then Is_Bit_Packed_Array (Etype (Prefix (N)))
5758 then
5759 return True;
5760
5761 elsif Nkind_In (N, N_Indexed_Component, N_Selected_Component) then
5762 return Is_Ref_To_Bit_Packed_Slice (Prefix (N));
5763
5764 else
5765 return False;
5766 end if;
5767 end Is_Ref_To_Bit_Packed_Slice;
5768
5769 -----------------------
5770 -- Is_Renamed_Object --
5771 -----------------------
5772
5773 function Is_Renamed_Object (N : Node_Id) return Boolean is
5774 Pnod : constant Node_Id := Parent (N);
5775 Kind : constant Node_Kind := Nkind (Pnod);
5776 begin
5777 if Kind = N_Object_Renaming_Declaration then
5778 return True;
5779 elsif Nkind_In (Kind, N_Indexed_Component, N_Selected_Component) then
5780 return Is_Renamed_Object (Pnod);
5781 else
5782 return False;
5783 end if;
5784 end Is_Renamed_Object;
5785
5786 --------------------------------------
5787 -- Is_Secondary_Stack_BIP_Func_Call --
5788 --------------------------------------
5789
5790 function Is_Secondary_Stack_BIP_Func_Call (Expr : Node_Id) return Boolean is
5791 Alloc_Nam : Name_Id := No_Name;
5792 Actual : Node_Id;
5793 Call : Node_Id := Expr;
5794 Formal : Node_Id;
5795 Param : Node_Id;
5796
5797 begin
5798 -- Build-in-place calls usually appear in 'reference format. Note that
5799 -- the accessibility check machinery may add an extra 'reference due to
5800 -- side effect removal.
5801
5802 while Nkind (Call) = N_Reference loop
5803 Call := Prefix (Call);
5804 end loop;
5805
5806 if Nkind_In (Call, N_Qualified_Expression,
5807 N_Unchecked_Type_Conversion)
5808 then
5809 Call := Expression (Call);
5810 end if;
5811
5812 if Is_Build_In_Place_Function_Call (Call) then
5813
5814 -- Examine all parameter associations of the function call
5815
5816 Param := First (Parameter_Associations (Call));
5817 while Present (Param) loop
5818 if Nkind (Param) = N_Parameter_Association
5819 and then Nkind (Selector_Name (Param)) = N_Identifier
5820 then
5821 Formal := Selector_Name (Param);
5822 Actual := Explicit_Actual_Parameter (Param);
5823
5824 -- Construct the name of formal BIPalloc. It is much easier to
5825 -- extract the name of the function using an arbitrary formal's
5826 -- scope rather than the Name field of Call.
5827
5828 if Alloc_Nam = No_Name and then Present (Entity (Formal)) then
5829 Alloc_Nam :=
5830 New_External_Name
5831 (Chars (Scope (Entity (Formal))),
5832 BIP_Formal_Suffix (BIP_Alloc_Form));
5833 end if;
5834
5835 -- A match for BIPalloc => 2 has been found
5836
5837 if Chars (Formal) = Alloc_Nam
5838 and then Nkind (Actual) = N_Integer_Literal
5839 and then Intval (Actual) = Uint_2
5840 then
5841 return True;
5842 end if;
5843 end if;
5844
5845 Next (Param);
5846 end loop;
5847 end if;
5848
5849 return False;
5850 end Is_Secondary_Stack_BIP_Func_Call;
5851
5852 -------------------------------------
5853 -- Is_Tag_To_Class_Wide_Conversion --
5854 -------------------------------------
5855
5856 function Is_Tag_To_Class_Wide_Conversion
5857 (Obj_Id : Entity_Id) return Boolean
5858 is
5859 Expr : constant Node_Id := Expression (Parent (Obj_Id));
5860
5861 begin
5862 return
5863 Is_Class_Wide_Type (Etype (Obj_Id))
5864 and then Present (Expr)
5865 and then Nkind (Expr) = N_Unchecked_Type_Conversion
5866 and then Etype (Expression (Expr)) = RTE (RE_Tag);
5867 end Is_Tag_To_Class_Wide_Conversion;
5868
5869 ----------------------------
5870 -- Is_Untagged_Derivation --
5871 ----------------------------
5872
5873 function Is_Untagged_Derivation (T : Entity_Id) return Boolean is
5874 begin
5875 return (not Is_Tagged_Type (T) and then Is_Derived_Type (T))
5876 or else
5877 (Is_Private_Type (T) and then Present (Full_View (T))
5878 and then not Is_Tagged_Type (Full_View (T))
5879 and then Is_Derived_Type (Full_View (T))
5880 and then Etype (Full_View (T)) /= T);
5881 end Is_Untagged_Derivation;
5882
5883 ---------------------------
5884 -- Is_Volatile_Reference --
5885 ---------------------------
5886
5887 function Is_Volatile_Reference (N : Node_Id) return Boolean is
5888 begin
5889 -- Only source references are to be treated as volatile, internally
5890 -- generated stuff cannot have volatile external effects.
5891
5892 if not Comes_From_Source (N) then
5893 return False;
5894
5895 -- Never true for reference to a type
5896
5897 elsif Is_Entity_Name (N) and then Is_Type (Entity (N)) then
5898 return False;
5899
5900 -- Never true for a compile time known constant
5901
5902 elsif Compile_Time_Known_Value (N) then
5903 return False;
5904
5905 -- True if object reference with volatile type
5906
5907 elsif Is_Volatile_Object (N) then
5908 return True;
5909
5910 -- True if reference to volatile entity
5911
5912 elsif Is_Entity_Name (N) then
5913 return Treat_As_Volatile (Entity (N));
5914
5915 -- True for slice of volatile array
5916
5917 elsif Nkind (N) = N_Slice then
5918 return Is_Volatile_Reference (Prefix (N));
5919
5920 -- True if volatile component
5921
5922 elsif Nkind_In (N, N_Indexed_Component, N_Selected_Component) then
5923 if (Is_Entity_Name (Prefix (N))
5924 and then Has_Volatile_Components (Entity (Prefix (N))))
5925 or else (Present (Etype (Prefix (N)))
5926 and then Has_Volatile_Components (Etype (Prefix (N))))
5927 then
5928 return True;
5929 else
5930 return Is_Volatile_Reference (Prefix (N));
5931 end if;
5932
5933 -- Otherwise false
5934
5935 else
5936 return False;
5937 end if;
5938 end Is_Volatile_Reference;
5939
5940 --------------------
5941 -- Kill_Dead_Code --
5942 --------------------
5943
5944 procedure Kill_Dead_Code (N : Node_Id; Warn : Boolean := False) is
5945 W : Boolean := Warn;
5946 -- Set False if warnings suppressed
5947
5948 begin
5949 if Present (N) then
5950 Remove_Warning_Messages (N);
5951
5952 -- Generate warning if appropriate
5953
5954 if W then
5955
5956 -- We suppress the warning if this code is under control of an
5957 -- if statement, whose condition is a simple identifier, and
5958 -- either we are in an instance, or warnings off is set for this
5959 -- identifier. The reason for killing it in the instance case is
5960 -- that it is common and reasonable for code to be deleted in
5961 -- instances for various reasons.
5962
5963 -- Could we use Is_Statically_Unevaluated here???
5964
5965 if Nkind (Parent (N)) = N_If_Statement then
5966 declare
5967 C : constant Node_Id := Condition (Parent (N));
5968 begin
5969 if Nkind (C) = N_Identifier
5970 and then
5971 (In_Instance
5972 or else (Present (Entity (C))
5973 and then Has_Warnings_Off (Entity (C))))
5974 then
5975 W := False;
5976 end if;
5977 end;
5978 end if;
5979
5980 -- Generate warning if not suppressed
5981
5982 if W then
5983 Error_Msg_F
5984 ("?t?this code can never be executed and has been deleted!",
5985 N);
5986 end if;
5987 end if;
5988
5989 -- Recurse into block statements and bodies to process declarations
5990 -- and statements.
5991
5992 if Nkind (N) = N_Block_Statement
5993 or else Nkind (N) = N_Subprogram_Body
5994 or else Nkind (N) = N_Package_Body
5995 then
5996 Kill_Dead_Code (Declarations (N), False);
5997 Kill_Dead_Code (Statements (Handled_Statement_Sequence (N)));
5998
5999 if Nkind (N) = N_Subprogram_Body then
6000 Set_Is_Eliminated (Defining_Entity (N));
6001 end if;
6002
6003 elsif Nkind (N) = N_Package_Declaration then
6004 Kill_Dead_Code (Visible_Declarations (Specification (N)));
6005 Kill_Dead_Code (Private_Declarations (Specification (N)));
6006
6007 -- ??? After this point, Delete_Tree has been called on all
6008 -- declarations in Specification (N), so references to entities
6009 -- therein look suspicious.
6010
6011 declare
6012 E : Entity_Id := First_Entity (Defining_Entity (N));
6013
6014 begin
6015 while Present (E) loop
6016 if Ekind (E) = E_Operator then
6017 Set_Is_Eliminated (E);
6018 end if;
6019
6020 Next_Entity (E);
6021 end loop;
6022 end;
6023
6024 -- Recurse into composite statement to kill individual statements in
6025 -- particular instantiations.
6026
6027 elsif Nkind (N) = N_If_Statement then
6028 Kill_Dead_Code (Then_Statements (N));
6029 Kill_Dead_Code (Elsif_Parts (N));
6030 Kill_Dead_Code (Else_Statements (N));
6031
6032 elsif Nkind (N) = N_Loop_Statement then
6033 Kill_Dead_Code (Statements (N));
6034
6035 elsif Nkind (N) = N_Case_Statement then
6036 declare
6037 Alt : Node_Id;
6038 begin
6039 Alt := First (Alternatives (N));
6040 while Present (Alt) loop
6041 Kill_Dead_Code (Statements (Alt));
6042 Next (Alt);
6043 end loop;
6044 end;
6045
6046 elsif Nkind (N) = N_Case_Statement_Alternative then
6047 Kill_Dead_Code (Statements (N));
6048
6049 -- Deal with dead instances caused by deleting instantiations
6050
6051 elsif Nkind (N) in N_Generic_Instantiation then
6052 Remove_Dead_Instance (N);
6053 end if;
6054 end if;
6055 end Kill_Dead_Code;
6056
6057 -- Case where argument is a list of nodes to be killed
6058
6059 procedure Kill_Dead_Code (L : List_Id; Warn : Boolean := False) is
6060 N : Node_Id;
6061 W : Boolean;
6062
6063 begin
6064 W := Warn;
6065
6066 if Is_Non_Empty_List (L) then
6067 N := First (L);
6068 while Present (N) loop
6069 Kill_Dead_Code (N, W);
6070 W := False;
6071 Next (N);
6072 end loop;
6073 end if;
6074 end Kill_Dead_Code;
6075
6076 ------------------------
6077 -- Known_Non_Negative --
6078 ------------------------
6079
6080 function Known_Non_Negative (Opnd : Node_Id) return Boolean is
6081 begin
6082 if Is_OK_Static_Expression (Opnd) and then Expr_Value (Opnd) >= 0 then
6083 return True;
6084
6085 else
6086 declare
6087 Lo : constant Node_Id := Type_Low_Bound (Etype (Opnd));
6088 begin
6089 return
6090 Is_OK_Static_Expression (Lo) and then Expr_Value (Lo) >= 0;
6091 end;
6092 end if;
6093 end Known_Non_Negative;
6094
6095 --------------------
6096 -- Known_Non_Null --
6097 --------------------
6098
6099 function Known_Non_Null (N : Node_Id) return Boolean is
6100 begin
6101 -- Checks for case where N is an entity reference
6102
6103 if Is_Entity_Name (N) and then Present (Entity (N)) then
6104 declare
6105 E : constant Entity_Id := Entity (N);
6106 Op : Node_Kind;
6107 Val : Node_Id;
6108
6109 begin
6110 -- First check if we are in decisive conditional
6111
6112 Get_Current_Value_Condition (N, Op, Val);
6113
6114 if Known_Null (Val) then
6115 if Op = N_Op_Eq then
6116 return False;
6117 elsif Op = N_Op_Ne then
6118 return True;
6119 end if;
6120 end if;
6121
6122 -- If OK to do replacement, test Is_Known_Non_Null flag
6123
6124 if OK_To_Do_Constant_Replacement (E) then
6125 return Is_Known_Non_Null (E);
6126
6127 -- Otherwise if not safe to do replacement, then say so
6128
6129 else
6130 return False;
6131 end if;
6132 end;
6133
6134 -- True if access attribute
6135
6136 elsif Nkind (N) = N_Attribute_Reference
6137 and then Nam_In (Attribute_Name (N), Name_Access,
6138 Name_Unchecked_Access,
6139 Name_Unrestricted_Access)
6140 then
6141 return True;
6142
6143 -- True if allocator
6144
6145 elsif Nkind (N) = N_Allocator then
6146 return True;
6147
6148 -- For a conversion, true if expression is known non-null
6149
6150 elsif Nkind (N) = N_Type_Conversion then
6151 return Known_Non_Null (Expression (N));
6152
6153 -- Above are all cases where the value could be determined to be
6154 -- non-null. In all other cases, we don't know, so return False.
6155
6156 else
6157 return False;
6158 end if;
6159 end Known_Non_Null;
6160
6161 ----------------
6162 -- Known_Null --
6163 ----------------
6164
6165 function Known_Null (N : Node_Id) return Boolean is
6166 begin
6167 -- Checks for case where N is an entity reference
6168
6169 if Is_Entity_Name (N) and then Present (Entity (N)) then
6170 declare
6171 E : constant Entity_Id := Entity (N);
6172 Op : Node_Kind;
6173 Val : Node_Id;
6174
6175 begin
6176 -- Constant null value is for sure null
6177
6178 if Ekind (E) = E_Constant
6179 and then Known_Null (Constant_Value (E))
6180 then
6181 return True;
6182 end if;
6183
6184 -- First check if we are in decisive conditional
6185
6186 Get_Current_Value_Condition (N, Op, Val);
6187
6188 if Known_Null (Val) then
6189 if Op = N_Op_Eq then
6190 return True;
6191 elsif Op = N_Op_Ne then
6192 return False;
6193 end if;
6194 end if;
6195
6196 -- If OK to do replacement, test Is_Known_Null flag
6197
6198 if OK_To_Do_Constant_Replacement (E) then
6199 return Is_Known_Null (E);
6200
6201 -- Otherwise if not safe to do replacement, then say so
6202
6203 else
6204 return False;
6205 end if;
6206 end;
6207
6208 -- True if explicit reference to null
6209
6210 elsif Nkind (N) = N_Null then
6211 return True;
6212
6213 -- For a conversion, true if expression is known null
6214
6215 elsif Nkind (N) = N_Type_Conversion then
6216 return Known_Null (Expression (N));
6217
6218 -- Above are all cases where the value could be determined to be null.
6219 -- In all other cases, we don't know, so return False.
6220
6221 else
6222 return False;
6223 end if;
6224 end Known_Null;
6225
6226 -----------------------------
6227 -- Make_CW_Equivalent_Type --
6228 -----------------------------
6229
6230 -- Create a record type used as an equivalent of any member of the class
6231 -- which takes its size from exp.
6232
6233 -- Generate the following code:
6234
6235 -- type Equiv_T is record
6236 -- _parent : T (List of discriminant constraints taken from Exp);
6237 -- Ext__50 : Storage_Array (1 .. (Exp'size - Typ'object_size)/8);
6238 -- end Equiv_T;
6239 --
6240 -- ??? Note that this type does not guarantee same alignment as all
6241 -- derived types
6242
6243 function Make_CW_Equivalent_Type
6244 (T : Entity_Id;
6245 E : Node_Id) return Entity_Id
6246 is
6247 Loc : constant Source_Ptr := Sloc (E);
6248 Root_Typ : constant Entity_Id := Root_Type (T);
6249 List_Def : constant List_Id := Empty_List;
6250 Comp_List : constant List_Id := New_List;
6251 Equiv_Type : Entity_Id;
6252 Range_Type : Entity_Id;
6253 Str_Type : Entity_Id;
6254 Constr_Root : Entity_Id;
6255 Sizexpr : Node_Id;
6256
6257 begin
6258 -- If the root type is already constrained, there are no discriminants
6259 -- in the expression.
6260
6261 if not Has_Discriminants (Root_Typ)
6262 or else Is_Constrained (Root_Typ)
6263 then
6264 Constr_Root := Root_Typ;
6265
6266 -- At this point in the expansion, non-limited view of the type
6267 -- must be available, otherwise the error will be reported later.
6268
6269 if From_Limited_With (Constr_Root)
6270 and then Present (Non_Limited_View (Constr_Root))
6271 then
6272 Constr_Root := Non_Limited_View (Constr_Root);
6273 end if;
6274
6275 else
6276 Constr_Root := Make_Temporary (Loc, 'R');
6277
6278 -- subtype cstr__n is T (List of discr constraints taken from Exp)
6279
6280 Append_To (List_Def,
6281 Make_Subtype_Declaration (Loc,
6282 Defining_Identifier => Constr_Root,
6283 Subtype_Indication => Make_Subtype_From_Expr (E, Root_Typ)));
6284 end if;
6285
6286 -- Generate the range subtype declaration
6287
6288 Range_Type := Make_Temporary (Loc, 'G');
6289
6290 if not Is_Interface (Root_Typ) then
6291
6292 -- subtype rg__xx is
6293 -- Storage_Offset range 1 .. (Expr'size - typ'size) / Storage_Unit
6294
6295 Sizexpr :=
6296 Make_Op_Subtract (Loc,
6297 Left_Opnd =>
6298 Make_Attribute_Reference (Loc,
6299 Prefix =>
6300 OK_Convert_To (T, Duplicate_Subexpr_No_Checks (E)),
6301 Attribute_Name => Name_Size),
6302 Right_Opnd =>
6303 Make_Attribute_Reference (Loc,
6304 Prefix => New_Occurrence_Of (Constr_Root, Loc),
6305 Attribute_Name => Name_Object_Size));
6306 else
6307 -- subtype rg__xx is
6308 -- Storage_Offset range 1 .. Expr'size / Storage_Unit
6309
6310 Sizexpr :=
6311 Make_Attribute_Reference (Loc,
6312 Prefix =>
6313 OK_Convert_To (T, Duplicate_Subexpr_No_Checks (E)),
6314 Attribute_Name => Name_Size);
6315 end if;
6316
6317 Set_Paren_Count (Sizexpr, 1);
6318
6319 Append_To (List_Def,
6320 Make_Subtype_Declaration (Loc,
6321 Defining_Identifier => Range_Type,
6322 Subtype_Indication =>
6323 Make_Subtype_Indication (Loc,
6324 Subtype_Mark => New_Occurrence_Of (RTE (RE_Storage_Offset), Loc),
6325 Constraint => Make_Range_Constraint (Loc,
6326 Range_Expression =>
6327 Make_Range (Loc,
6328 Low_Bound => Make_Integer_Literal (Loc, 1),
6329 High_Bound =>
6330 Make_Op_Divide (Loc,
6331 Left_Opnd => Sizexpr,
6332 Right_Opnd => Make_Integer_Literal (Loc,
6333 Intval => System_Storage_Unit)))))));
6334
6335 -- subtype str__nn is Storage_Array (rg__x);
6336
6337 Str_Type := Make_Temporary (Loc, 'S');
6338 Append_To (List_Def,
6339 Make_Subtype_Declaration (Loc,
6340 Defining_Identifier => Str_Type,
6341 Subtype_Indication =>
6342 Make_Subtype_Indication (Loc,
6343 Subtype_Mark => New_Occurrence_Of (RTE (RE_Storage_Array), Loc),
6344 Constraint =>
6345 Make_Index_Or_Discriminant_Constraint (Loc,
6346 Constraints =>
6347 New_List (New_Occurrence_Of (Range_Type, Loc))))));
6348
6349 -- type Equiv_T is record
6350 -- [ _parent : Tnn; ]
6351 -- E : Str_Type;
6352 -- end Equiv_T;
6353
6354 Equiv_Type := Make_Temporary (Loc, 'T');
6355 Set_Ekind (Equiv_Type, E_Record_Type);
6356 Set_Parent_Subtype (Equiv_Type, Constr_Root);
6357
6358 -- Set Is_Class_Wide_Equivalent_Type very early to trigger the special
6359 -- treatment for this type. In particular, even though _parent's type
6360 -- is a controlled type or contains controlled components, we do not
6361 -- want to set Has_Controlled_Component on it to avoid making it gain
6362 -- an unwanted _controller component.
6363
6364 Set_Is_Class_Wide_Equivalent_Type (Equiv_Type);
6365
6366 -- A class-wide equivalent type does not require initialization
6367
6368 Set_Suppress_Initialization (Equiv_Type);
6369
6370 if not Is_Interface (Root_Typ) then
6371 Append_To (Comp_List,
6372 Make_Component_Declaration (Loc,
6373 Defining_Identifier =>
6374 Make_Defining_Identifier (Loc, Name_uParent),
6375 Component_Definition =>
6376 Make_Component_Definition (Loc,
6377 Aliased_Present => False,
6378 Subtype_Indication => New_Occurrence_Of (Constr_Root, Loc))));
6379 end if;
6380
6381 Append_To (Comp_List,
6382 Make_Component_Declaration (Loc,
6383 Defining_Identifier => Make_Temporary (Loc, 'C'),
6384 Component_Definition =>
6385 Make_Component_Definition (Loc,
6386 Aliased_Present => False,
6387 Subtype_Indication => New_Occurrence_Of (Str_Type, Loc))));
6388
6389 Append_To (List_Def,
6390 Make_Full_Type_Declaration (Loc,
6391 Defining_Identifier => Equiv_Type,
6392 Type_Definition =>
6393 Make_Record_Definition (Loc,
6394 Component_List =>
6395 Make_Component_List (Loc,
6396 Component_Items => Comp_List,
6397 Variant_Part => Empty))));
6398
6399 -- Suppress all checks during the analysis of the expanded code to avoid
6400 -- the generation of spurious warnings under ZFP run-time.
6401
6402 Insert_Actions (E, List_Def, Suppress => All_Checks);
6403 return Equiv_Type;
6404 end Make_CW_Equivalent_Type;
6405
6406 -------------------------
6407 -- Make_Invariant_Call --
6408 -------------------------
6409
6410 function Make_Invariant_Call (Expr : Node_Id) return Node_Id is
6411 Loc : constant Source_Ptr := Sloc (Expr);
6412 Typ : constant Entity_Id := Base_Type (Etype (Expr));
6413 Proc_Id : Entity_Id;
6414
6415 begin
6416 pragma Assert (Has_Invariants (Typ));
6417
6418 Proc_Id := Invariant_Procedure (Typ);
6419 pragma Assert (Present (Proc_Id));
6420
6421 return
6422 Make_Procedure_Call_Statement (Loc,
6423 Name => New_Occurrence_Of (Proc_Id, Loc),
6424 Parameter_Associations => New_List (Relocate_Node (Expr)));
6425 end Make_Invariant_Call;
6426
6427 ------------------------
6428 -- Make_Literal_Range --
6429 ------------------------
6430
6431 function Make_Literal_Range
6432 (Loc : Source_Ptr;
6433 Literal_Typ : Entity_Id) return Node_Id
6434 is
6435 Lo : constant Node_Id :=
6436 New_Copy_Tree (String_Literal_Low_Bound (Literal_Typ));
6437 Index : constant Entity_Id := Etype (Lo);
6438
6439 Hi : Node_Id;
6440 Length_Expr : constant Node_Id :=
6441 Make_Op_Subtract (Loc,
6442 Left_Opnd =>
6443 Make_Integer_Literal (Loc,
6444 Intval => String_Literal_Length (Literal_Typ)),
6445 Right_Opnd =>
6446 Make_Integer_Literal (Loc, 1));
6447
6448 begin
6449 Set_Analyzed (Lo, False);
6450
6451 if Is_Integer_Type (Index) then
6452 Hi :=
6453 Make_Op_Add (Loc,
6454 Left_Opnd => New_Copy_Tree (Lo),
6455 Right_Opnd => Length_Expr);
6456 else
6457 Hi :=
6458 Make_Attribute_Reference (Loc,
6459 Attribute_Name => Name_Val,
6460 Prefix => New_Occurrence_Of (Index, Loc),
6461 Expressions => New_List (
6462 Make_Op_Add (Loc,
6463 Left_Opnd =>
6464 Make_Attribute_Reference (Loc,
6465 Attribute_Name => Name_Pos,
6466 Prefix => New_Occurrence_Of (Index, Loc),
6467 Expressions => New_List (New_Copy_Tree (Lo))),
6468 Right_Opnd => Length_Expr)));
6469 end if;
6470
6471 return
6472 Make_Range (Loc,
6473 Low_Bound => Lo,
6474 High_Bound => Hi);
6475 end Make_Literal_Range;
6476
6477 --------------------------
6478 -- Make_Non_Empty_Check --
6479 --------------------------
6480
6481 function Make_Non_Empty_Check
6482 (Loc : Source_Ptr;
6483 N : Node_Id) return Node_Id
6484 is
6485 begin
6486 return
6487 Make_Op_Ne (Loc,
6488 Left_Opnd =>
6489 Make_Attribute_Reference (Loc,
6490 Attribute_Name => Name_Length,
6491 Prefix => Duplicate_Subexpr_No_Checks (N, Name_Req => True)),
6492 Right_Opnd =>
6493 Make_Integer_Literal (Loc, 0));
6494 end Make_Non_Empty_Check;
6495
6496 -------------------------
6497 -- Make_Predicate_Call --
6498 -------------------------
6499
6500 function Make_Predicate_Call
6501 (Typ : Entity_Id;
6502 Expr : Node_Id;
6503 Mem : Boolean := False) return Node_Id
6504 is
6505 Loc : constant Source_Ptr := Sloc (Expr);
6506 Call : Node_Id;
6507 PFM : Entity_Id;
6508
6509 Save_Ghost_Mode : constant Ghost_Mode_Type := Ghost_Mode;
6510
6511 begin
6512 pragma Assert (Present (Predicate_Function (Typ)));
6513
6514 -- The related type may be subject to pragma Ghost. Set the mode now to
6515 -- ensure that the call is properly marked as Ghost.
6516
6517 Set_Ghost_Mode_From_Entity (Typ);
6518
6519 -- Call special membership version if requested and available
6520
6521 if Mem then
6522 PFM := Predicate_Function_M (Typ);
6523
6524 if Present (PFM) then
6525 Call :=
6526 Make_Function_Call (Loc,
6527 Name => New_Occurrence_Of (PFM, Loc),
6528 Parameter_Associations => New_List (Relocate_Node (Expr)));
6529
6530 Ghost_Mode := Save_Ghost_Mode;
6531 return Call;
6532 end if;
6533 end if;
6534
6535 -- Case of calling normal predicate function
6536
6537 Call :=
6538 Make_Function_Call (Loc,
6539 Name =>
6540 New_Occurrence_Of (Predicate_Function (Typ), Loc),
6541 Parameter_Associations => New_List (Relocate_Node (Expr)));
6542
6543 Ghost_Mode := Save_Ghost_Mode;
6544 return Call;
6545 end Make_Predicate_Call;
6546
6547 --------------------------
6548 -- Make_Predicate_Check --
6549 --------------------------
6550
6551 function Make_Predicate_Check
6552 (Typ : Entity_Id;
6553 Expr : Node_Id) return Node_Id
6554 is
6555 procedure Replace_Subtype_Reference (N : Node_Id);
6556 -- Replace current occurrences of the subtype to which a dynamic
6557 -- predicate applies, by the expression that triggers a predicate
6558 -- check. This is needed for aspect Predicate_Failure, for which
6559 -- we do not generate a wrapper procedure, but simply modify the
6560 -- expression for the pragma of the predicate check.
6561
6562 --------------------------------
6563 -- Replace_Subtype_Reference --
6564 --------------------------------
6565
6566 procedure Replace_Subtype_Reference (N : Node_Id) is
6567 begin
6568 Rewrite (N, New_Copy_Tree (Expr));
6569
6570 -- We want to treat the node as if it comes from source, so
6571 -- that ASIS will not ignore it.
6572
6573 Set_Comes_From_Source (N, True);
6574 end Replace_Subtype_Reference;
6575
6576 procedure Replace_Subtype_References is
6577 new Replace_Type_References_Generic (Replace_Subtype_Reference);
6578
6579 -- Local variables
6580
6581 Loc : constant Source_Ptr := Sloc (Expr);
6582 Arg_List : List_Id;
6583 Fail_Expr : Node_Id;
6584 Nam : Name_Id;
6585
6586 -- Start of processing for Make_Predicate_Check
6587
6588 begin
6589 -- If predicate checks are suppressed, then return a null statement. For
6590 -- this call, we check only the scope setting. If the caller wants to
6591 -- check a specific entity's setting, they must do it manually.
6592
6593 if Predicate_Checks_Suppressed (Empty) then
6594 return Make_Null_Statement (Loc);
6595 end if;
6596
6597 -- Do not generate a check within an internal subprogram (stream
6598 -- functions and the like, including including predicate functions).
6599
6600 if Within_Internal_Subprogram then
6601 return Make_Null_Statement (Loc);
6602 end if;
6603
6604 -- Compute proper name to use, we need to get this right so that the
6605 -- right set of check policies apply to the Check pragma we are making.
6606
6607 if Has_Dynamic_Predicate_Aspect (Typ) then
6608 Nam := Name_Dynamic_Predicate;
6609 elsif Has_Static_Predicate_Aspect (Typ) then
6610 Nam := Name_Static_Predicate;
6611 else
6612 Nam := Name_Predicate;
6613 end if;
6614
6615 Arg_List := New_List (
6616 Make_Pragma_Argument_Association (Loc,
6617 Expression => Make_Identifier (Loc, Nam)),
6618 Make_Pragma_Argument_Association (Loc,
6619 Expression => Make_Predicate_Call (Typ, Expr)));
6620
6621 -- If subtype has Predicate_Failure defined, add the correponding
6622 -- expression as an additional pragma parameter, after replacing
6623 -- current instances with the expression being checked.
6624
6625 if Has_Aspect (Typ, Aspect_Predicate_Failure) then
6626 Fail_Expr :=
6627 New_Copy_Tree
6628 (Expression (Find_Aspect (Typ, Aspect_Predicate_Failure)));
6629 Replace_Subtype_References (Fail_Expr, Typ);
6630
6631 Append_To (Arg_List,
6632 Make_Pragma_Argument_Association (Loc,
6633 Expression => Fail_Expr));
6634 end if;
6635
6636 return
6637 Make_Pragma (Loc,
6638 Pragma_Identifier => Make_Identifier (Loc, Name_Check),
6639 Pragma_Argument_Associations => Arg_List);
6640 end Make_Predicate_Check;
6641
6642 ----------------------------
6643 -- Make_Subtype_From_Expr --
6644 ----------------------------
6645
6646 -- 1. If Expr is an unconstrained array expression, creates
6647 -- Unc_Type(Expr'first(1)..Expr'last(1),..., Expr'first(n)..Expr'last(n))
6648
6649 -- 2. If Expr is a unconstrained discriminated type expression, creates
6650 -- Unc_Type(Expr.Discr1, ... , Expr.Discr_n)
6651
6652 -- 3. If Expr is class-wide, creates an implicit class-wide subtype
6653
6654 function Make_Subtype_From_Expr
6655 (E : Node_Id;
6656 Unc_Typ : Entity_Id;
6657 Related_Id : Entity_Id := Empty) return Node_Id
6658 is
6659 List_Constr : constant List_Id := New_List;
6660 Loc : constant Source_Ptr := Sloc (E);
6661 D : Entity_Id;
6662 Full_Exp : Node_Id;
6663 Full_Subtyp : Entity_Id;
6664 High_Bound : Entity_Id;
6665 Index_Typ : Entity_Id;
6666 Low_Bound : Entity_Id;
6667 Priv_Subtyp : Entity_Id;
6668 Utyp : Entity_Id;
6669
6670 begin
6671 if Is_Private_Type (Unc_Typ)
6672 and then Has_Unknown_Discriminants (Unc_Typ)
6673 then
6674 -- The caller requests a unique external name for both the private
6675 -- and the full subtype.
6676
6677 if Present (Related_Id) then
6678 Full_Subtyp :=
6679 Make_Defining_Identifier (Loc,
6680 Chars => New_External_Name (Chars (Related_Id), 'C'));
6681 Priv_Subtyp :=
6682 Make_Defining_Identifier (Loc,
6683 Chars => New_External_Name (Chars (Related_Id), 'P'));
6684
6685 else
6686 Full_Subtyp := Make_Temporary (Loc, 'C');
6687 Priv_Subtyp := Make_Temporary (Loc, 'P');
6688 end if;
6689
6690 -- Prepare the subtype completion. Use the base type to find the
6691 -- underlying type because the type may be a generic actual or an
6692 -- explicit subtype.
6693
6694 Utyp := Underlying_Type (Base_Type (Unc_Typ));
6695
6696 Full_Exp :=
6697 Unchecked_Convert_To (Utyp, Duplicate_Subexpr_No_Checks (E));
6698 Set_Parent (Full_Exp, Parent (E));
6699
6700 Insert_Action (E,
6701 Make_Subtype_Declaration (Loc,
6702 Defining_Identifier => Full_Subtyp,
6703 Subtype_Indication => Make_Subtype_From_Expr (Full_Exp, Utyp)));
6704
6705 -- Define the dummy private subtype
6706
6707 Set_Ekind (Priv_Subtyp, Subtype_Kind (Ekind (Unc_Typ)));
6708 Set_Etype (Priv_Subtyp, Base_Type (Unc_Typ));
6709 Set_Scope (Priv_Subtyp, Full_Subtyp);
6710 Set_Is_Constrained (Priv_Subtyp);
6711 Set_Is_Tagged_Type (Priv_Subtyp, Is_Tagged_Type (Unc_Typ));
6712 Set_Is_Itype (Priv_Subtyp);
6713 Set_Associated_Node_For_Itype (Priv_Subtyp, E);
6714
6715 if Is_Tagged_Type (Priv_Subtyp) then
6716 Set_Class_Wide_Type
6717 (Base_Type (Priv_Subtyp), Class_Wide_Type (Unc_Typ));
6718 Set_Direct_Primitive_Operations (Priv_Subtyp,
6719 Direct_Primitive_Operations (Unc_Typ));
6720 end if;
6721
6722 Set_Full_View (Priv_Subtyp, Full_Subtyp);
6723
6724 return New_Occurrence_Of (Priv_Subtyp, Loc);
6725
6726 elsif Is_Array_Type (Unc_Typ) then
6727 Index_Typ := First_Index (Unc_Typ);
6728 for J in 1 .. Number_Dimensions (Unc_Typ) loop
6729
6730 -- Capture the bounds of each index constraint in case the context
6731 -- is an object declaration of an unconstrained type initialized
6732 -- by a function call:
6733
6734 -- Obj : Unconstr_Typ := Func_Call;
6735
6736 -- This scenario requires secondary scope management and the index
6737 -- constraint cannot depend on the temporary used to capture the
6738 -- result of the function call.
6739
6740 -- SS_Mark;
6741 -- Temp : Unconstr_Typ_Ptr := Func_Call'reference;
6742 -- subtype S is Unconstr_Typ (Temp.all'First .. Temp.all'Last);
6743 -- Obj : S := Temp.all;
6744 -- SS_Release; -- Temp is gone at this point, bounds of S are
6745 -- -- non existent.
6746
6747 -- Generate:
6748 -- Low_Bound : constant Base_Type (Index_Typ) := E'First (J);
6749
6750 Low_Bound := Make_Temporary (Loc, 'B');
6751 Insert_Action (E,
6752 Make_Object_Declaration (Loc,
6753 Defining_Identifier => Low_Bound,
6754 Object_Definition =>
6755 New_Occurrence_Of (Base_Type (Etype (Index_Typ)), Loc),
6756 Constant_Present => True,
6757 Expression =>
6758 Make_Attribute_Reference (Loc,
6759 Prefix => Duplicate_Subexpr_No_Checks (E),
6760 Attribute_Name => Name_First,
6761 Expressions => New_List (
6762 Make_Integer_Literal (Loc, J)))));
6763
6764 -- Generate:
6765 -- High_Bound : constant Base_Type (Index_Typ) := E'Last (J);
6766
6767 High_Bound := Make_Temporary (Loc, 'B');
6768 Insert_Action (E,
6769 Make_Object_Declaration (Loc,
6770 Defining_Identifier => High_Bound,
6771 Object_Definition =>
6772 New_Occurrence_Of (Base_Type (Etype (Index_Typ)), Loc),
6773 Constant_Present => True,
6774 Expression =>
6775 Make_Attribute_Reference (Loc,
6776 Prefix => Duplicate_Subexpr_No_Checks (E),
6777 Attribute_Name => Name_Last,
6778 Expressions => New_List (
6779 Make_Integer_Literal (Loc, J)))));
6780
6781 Append_To (List_Constr,
6782 Make_Range (Loc,
6783 Low_Bound => New_Occurrence_Of (Low_Bound, Loc),
6784 High_Bound => New_Occurrence_Of (High_Bound, Loc)));
6785
6786 Index_Typ := Next_Index (Index_Typ);
6787 end loop;
6788
6789 elsif Is_Class_Wide_Type (Unc_Typ) then
6790 declare
6791 CW_Subtype : Entity_Id;
6792 EQ_Typ : Entity_Id := Empty;
6793
6794 begin
6795 -- A class-wide equivalent type is not needed on VM targets
6796 -- because the VM back-ends handle the class-wide object
6797 -- initialization itself (and doesn't need or want the
6798 -- additional intermediate type to handle the assignment).
6799
6800 if Expander_Active and then Tagged_Type_Expansion then
6801
6802 -- If this is the class-wide type of a completion that is a
6803 -- record subtype, set the type of the class-wide type to be
6804 -- the full base type, for use in the expanded code for the
6805 -- equivalent type. Should this be done earlier when the
6806 -- completion is analyzed ???
6807
6808 if Is_Private_Type (Etype (Unc_Typ))
6809 and then
6810 Ekind (Full_View (Etype (Unc_Typ))) = E_Record_Subtype
6811 then
6812 Set_Etype (Unc_Typ, Base_Type (Full_View (Etype (Unc_Typ))));
6813 end if;
6814
6815 EQ_Typ := Make_CW_Equivalent_Type (Unc_Typ, E);
6816 end if;
6817
6818 CW_Subtype := New_Class_Wide_Subtype (Unc_Typ, E);
6819 Set_Equivalent_Type (CW_Subtype, EQ_Typ);
6820 Set_Cloned_Subtype (CW_Subtype, Base_Type (Unc_Typ));
6821
6822 return New_Occurrence_Of (CW_Subtype, Loc);
6823 end;
6824
6825 -- Indefinite record type with discriminants
6826
6827 else
6828 D := First_Discriminant (Unc_Typ);
6829 while Present (D) loop
6830 Append_To (List_Constr,
6831 Make_Selected_Component (Loc,
6832 Prefix => Duplicate_Subexpr_No_Checks (E),
6833 Selector_Name => New_Occurrence_Of (D, Loc)));
6834
6835 Next_Discriminant (D);
6836 end loop;
6837 end if;
6838
6839 return
6840 Make_Subtype_Indication (Loc,
6841 Subtype_Mark => New_Occurrence_Of (Unc_Typ, Loc),
6842 Constraint =>
6843 Make_Index_Or_Discriminant_Constraint (Loc,
6844 Constraints => List_Constr));
6845 end Make_Subtype_From_Expr;
6846
6847 ----------------------------
6848 -- Matching_Standard_Type --
6849 ----------------------------
6850
6851 function Matching_Standard_Type (Typ : Entity_Id) return Entity_Id is
6852 pragma Assert (Is_Scalar_Type (Typ));
6853 Siz : constant Uint := Esize (Typ);
6854
6855 begin
6856 -- Floating-point cases
6857
6858 if Is_Floating_Point_Type (Typ) then
6859 if Siz <= Esize (Standard_Short_Float) then
6860 return Standard_Short_Float;
6861 elsif Siz <= Esize (Standard_Float) then
6862 return Standard_Float;
6863 elsif Siz <= Esize (Standard_Long_Float) then
6864 return Standard_Long_Float;
6865 elsif Siz <= Esize (Standard_Long_Long_Float) then
6866 return Standard_Long_Long_Float;
6867 else
6868 raise Program_Error;
6869 end if;
6870
6871 -- Integer cases (includes fixed-point types)
6872
6873 -- Unsigned integer cases (includes normal enumeration types)
6874
6875 elsif Is_Unsigned_Type (Typ) then
6876 if Siz <= Esize (Standard_Short_Short_Unsigned) then
6877 return Standard_Short_Short_Unsigned;
6878 elsif Siz <= Esize (Standard_Short_Unsigned) then
6879 return Standard_Short_Unsigned;
6880 elsif Siz <= Esize (Standard_Unsigned) then
6881 return Standard_Unsigned;
6882 elsif Siz <= Esize (Standard_Long_Unsigned) then
6883 return Standard_Long_Unsigned;
6884 elsif Siz <= Esize (Standard_Long_Long_Unsigned) then
6885 return Standard_Long_Long_Unsigned;
6886 else
6887 raise Program_Error;
6888 end if;
6889
6890 -- Signed integer cases
6891
6892 else
6893 if Siz <= Esize (Standard_Short_Short_Integer) then
6894 return Standard_Short_Short_Integer;
6895 elsif Siz <= Esize (Standard_Short_Integer) then
6896 return Standard_Short_Integer;
6897 elsif Siz <= Esize (Standard_Integer) then
6898 return Standard_Integer;
6899 elsif Siz <= Esize (Standard_Long_Integer) then
6900 return Standard_Long_Integer;
6901 elsif Siz <= Esize (Standard_Long_Long_Integer) then
6902 return Standard_Long_Long_Integer;
6903 else
6904 raise Program_Error;
6905 end if;
6906 end if;
6907 end Matching_Standard_Type;
6908
6909 -----------------------------
6910 -- May_Generate_Large_Temp --
6911 -----------------------------
6912
6913 -- At the current time, the only types that we return False for (i.e. where
6914 -- we decide we know they cannot generate large temps) are ones where we
6915 -- know the size is 256 bits or less at compile time, and we are still not
6916 -- doing a thorough job on arrays and records ???
6917
6918 function May_Generate_Large_Temp (Typ : Entity_Id) return Boolean is
6919 begin
6920 if not Size_Known_At_Compile_Time (Typ) then
6921 return False;
6922
6923 elsif Esize (Typ) /= 0 and then Esize (Typ) <= 256 then
6924 return False;
6925
6926 elsif Is_Array_Type (Typ)
6927 and then Present (Packed_Array_Impl_Type (Typ))
6928 then
6929 return May_Generate_Large_Temp (Packed_Array_Impl_Type (Typ));
6930
6931 -- We could do more here to find other small types ???
6932
6933 else
6934 return True;
6935 end if;
6936 end May_Generate_Large_Temp;
6937
6938 ------------------------
6939 -- Needs_Finalization --
6940 ------------------------
6941
6942 function Needs_Finalization (T : Entity_Id) return Boolean is
6943 function Has_Some_Controlled_Component (Rec : Entity_Id) return Boolean;
6944 -- If type is not frozen yet, check explicitly among its components,
6945 -- because the Has_Controlled_Component flag is not necessarily set.
6946
6947 -----------------------------------
6948 -- Has_Some_Controlled_Component --
6949 -----------------------------------
6950
6951 function Has_Some_Controlled_Component
6952 (Rec : Entity_Id) return Boolean
6953 is
6954 Comp : Entity_Id;
6955
6956 begin
6957 if Has_Controlled_Component (Rec) then
6958 return True;
6959
6960 elsif not Is_Frozen (Rec) then
6961 if Is_Record_Type (Rec) then
6962 Comp := First_Entity (Rec);
6963
6964 while Present (Comp) loop
6965 if not Is_Type (Comp)
6966 and then Needs_Finalization (Etype (Comp))
6967 then
6968 return True;
6969 end if;
6970
6971 Next_Entity (Comp);
6972 end loop;
6973
6974 return False;
6975
6976 else
6977 return
6978 Is_Array_Type (Rec)
6979 and then Needs_Finalization (Component_Type (Rec));
6980 end if;
6981 else
6982 return False;
6983 end if;
6984 end Has_Some_Controlled_Component;
6985
6986 -- Start of processing for Needs_Finalization
6987
6988 begin
6989 -- Certain run-time configurations and targets do not provide support
6990 -- for controlled types.
6991
6992 if Restriction_Active (No_Finalization) then
6993 return False;
6994
6995 -- C++ types are not considered controlled. It is assumed that the
6996 -- non-Ada side will handle their clean up.
6997
6998 elsif Convention (T) = Convention_CPP then
6999 return False;
7000
7001 -- Never needs finalization if Disable_Controlled set
7002
7003 elsif Disable_Controlled (T) then
7004 return False;
7005
7006 elsif Is_Class_Wide_Type (T) and then Disable_Controlled (Etype (T)) then
7007 return False;
7008
7009 else
7010 -- Class-wide types are treated as controlled because derivations
7011 -- from the root type can introduce controlled components.
7012
7013 return Is_Class_Wide_Type (T)
7014 or else Is_Controlled (T)
7015 or else Has_Some_Controlled_Component (T)
7016 or else
7017 (Is_Concurrent_Type (T)
7018 and then Present (Corresponding_Record_Type (T))
7019 and then Needs_Finalization (Corresponding_Record_Type (T)));
7020 end if;
7021 end Needs_Finalization;
7022
7023 ----------------------------
7024 -- Needs_Constant_Address --
7025 ----------------------------
7026
7027 function Needs_Constant_Address
7028 (Decl : Node_Id;
7029 Typ : Entity_Id) return Boolean
7030 is
7031 begin
7032
7033 -- If we have no initialization of any kind, then we don't need to place
7034 -- any restrictions on the address clause, because the object will be
7035 -- elaborated after the address clause is evaluated. This happens if the
7036 -- declaration has no initial expression, or the type has no implicit
7037 -- initialization, or the object is imported.
7038
7039 -- The same holds for all initialized scalar types and all access types.
7040 -- Packed bit arrays of size up to 64 are represented using a modular
7041 -- type with an initialization (to zero) and can be processed like other
7042 -- initialized scalar types.
7043
7044 -- If the type is controlled, code to attach the object to a
7045 -- finalization chain is generated at the point of declaration, and
7046 -- therefore the elaboration of the object cannot be delayed: the
7047 -- address expression must be a constant.
7048
7049 if No (Expression (Decl))
7050 and then not Needs_Finalization (Typ)
7051 and then
7052 (not Has_Non_Null_Base_Init_Proc (Typ)
7053 or else Is_Imported (Defining_Identifier (Decl)))
7054 then
7055 return False;
7056
7057 elsif (Present (Expression (Decl)) and then Is_Scalar_Type (Typ))
7058 or else Is_Access_Type (Typ)
7059 or else
7060 (Is_Bit_Packed_Array (Typ)
7061 and then Is_Modular_Integer_Type (Packed_Array_Impl_Type (Typ)))
7062 then
7063 return False;
7064
7065 else
7066
7067 -- Otherwise, we require the address clause to be constant because
7068 -- the call to the initialization procedure (or the attach code) has
7069 -- to happen at the point of the declaration.
7070
7071 -- Actually the IP call has been moved to the freeze actions anyway,
7072 -- so maybe we can relax this restriction???
7073
7074 return True;
7075 end if;
7076 end Needs_Constant_Address;
7077
7078 ----------------------------
7079 -- New_Class_Wide_Subtype --
7080 ----------------------------
7081
7082 function New_Class_Wide_Subtype
7083 (CW_Typ : Entity_Id;
7084 N : Node_Id) return Entity_Id
7085 is
7086 Res : constant Entity_Id := Create_Itype (E_Void, N);
7087 Res_Name : constant Name_Id := Chars (Res);
7088 Res_Scope : constant Entity_Id := Scope (Res);
7089
7090 begin
7091 Copy_Node (CW_Typ, Res);
7092 Set_Comes_From_Source (Res, False);
7093 Set_Sloc (Res, Sloc (N));
7094 Set_Is_Itype (Res);
7095 Set_Associated_Node_For_Itype (Res, N);
7096 Set_Is_Public (Res, False); -- By default, may be changed below.
7097 Set_Public_Status (Res);
7098 Set_Chars (Res, Res_Name);
7099 Set_Scope (Res, Res_Scope);
7100 Set_Ekind (Res, E_Class_Wide_Subtype);
7101 Set_Next_Entity (Res, Empty);
7102 Set_Etype (Res, Base_Type (CW_Typ));
7103 Set_Is_Frozen (Res, False);
7104 Set_Freeze_Node (Res, Empty);
7105 return (Res);
7106 end New_Class_Wide_Subtype;
7107
7108 --------------------------------
7109 -- Non_Limited_Designated_Type --
7110 ---------------------------------
7111
7112 function Non_Limited_Designated_Type (T : Entity_Id) return Entity_Id is
7113 Desig : constant Entity_Id := Designated_Type (T);
7114 begin
7115 if Has_Non_Limited_View (Desig) then
7116 return Non_Limited_View (Desig);
7117 else
7118 return Desig;
7119 end if;
7120 end Non_Limited_Designated_Type;
7121
7122 -----------------------------------
7123 -- OK_To_Do_Constant_Replacement --
7124 -----------------------------------
7125
7126 function OK_To_Do_Constant_Replacement (E : Entity_Id) return Boolean is
7127 ES : constant Entity_Id := Scope (E);
7128 CS : Entity_Id;
7129
7130 begin
7131 -- Do not replace statically allocated objects, because they may be
7132 -- modified outside the current scope.
7133
7134 if Is_Statically_Allocated (E) then
7135 return False;
7136
7137 -- Do not replace aliased or volatile objects, since we don't know what
7138 -- else might change the value.
7139
7140 elsif Is_Aliased (E) or else Treat_As_Volatile (E) then
7141 return False;
7142
7143 -- Debug flag -gnatdM disconnects this optimization
7144
7145 elsif Debug_Flag_MM then
7146 return False;
7147
7148 -- Otherwise check scopes
7149
7150 else
7151 CS := Current_Scope;
7152
7153 loop
7154 -- If we are in right scope, replacement is safe
7155
7156 if CS = ES then
7157 return True;
7158
7159 -- Packages do not affect the determination of safety
7160
7161 elsif Ekind (CS) = E_Package then
7162 exit when CS = Standard_Standard;
7163 CS := Scope (CS);
7164
7165 -- Blocks do not affect the determination of safety
7166
7167 elsif Ekind (CS) = E_Block then
7168 CS := Scope (CS);
7169
7170 -- Loops do not affect the determination of safety. Note that we
7171 -- kill all current values on entry to a loop, so we are just
7172 -- talking about processing within a loop here.
7173
7174 elsif Ekind (CS) = E_Loop then
7175 CS := Scope (CS);
7176
7177 -- Otherwise, the reference is dubious, and we cannot be sure that
7178 -- it is safe to do the replacement.
7179
7180 else
7181 exit;
7182 end if;
7183 end loop;
7184
7185 return False;
7186 end if;
7187 end OK_To_Do_Constant_Replacement;
7188
7189 ------------------------------------
7190 -- Possible_Bit_Aligned_Component --
7191 ------------------------------------
7192
7193 function Possible_Bit_Aligned_Component (N : Node_Id) return Boolean is
7194 begin
7195 -- Do not process an unanalyzed node because it is not yet decorated and
7196 -- most checks performed below will fail.
7197
7198 if not Analyzed (N) then
7199 return False;
7200 end if;
7201
7202 case Nkind (N) is
7203
7204 -- Case of indexed component
7205
7206 when N_Indexed_Component =>
7207 declare
7208 P : constant Node_Id := Prefix (N);
7209 Ptyp : constant Entity_Id := Etype (P);
7210
7211 begin
7212 -- If we know the component size and it is less than 64, then
7213 -- we are definitely OK. The back end always does assignment of
7214 -- misaligned small objects correctly.
7215
7216 if Known_Static_Component_Size (Ptyp)
7217 and then Component_Size (Ptyp) <= 64
7218 then
7219 return False;
7220
7221 -- Otherwise, we need to test the prefix, to see if we are
7222 -- indexing from a possibly unaligned component.
7223
7224 else
7225 return Possible_Bit_Aligned_Component (P);
7226 end if;
7227 end;
7228
7229 -- Case of selected component
7230
7231 when N_Selected_Component =>
7232 declare
7233 P : constant Node_Id := Prefix (N);
7234 Comp : constant Entity_Id := Entity (Selector_Name (N));
7235
7236 begin
7237 -- If there is no component clause, then we are in the clear
7238 -- since the back end will never misalign a large component
7239 -- unless it is forced to do so. In the clear means we need
7240 -- only the recursive test on the prefix.
7241
7242 if Component_May_Be_Bit_Aligned (Comp) then
7243 return True;
7244 else
7245 return Possible_Bit_Aligned_Component (P);
7246 end if;
7247 end;
7248
7249 -- For a slice, test the prefix, if that is possibly misaligned,
7250 -- then for sure the slice is.
7251
7252 when N_Slice =>
7253 return Possible_Bit_Aligned_Component (Prefix (N));
7254
7255 -- For an unchecked conversion, check whether the expression may
7256 -- be bit-aligned.
7257
7258 when N_Unchecked_Type_Conversion =>
7259 return Possible_Bit_Aligned_Component (Expression (N));
7260
7261 -- If we have none of the above, it means that we have fallen off the
7262 -- top testing prefixes recursively, and we now have a stand alone
7263 -- object, where we don't have a problem, unless this is a renaming,
7264 -- in which case we need to look into the renamed object.
7265
7266 when others =>
7267 if Is_Entity_Name (N)
7268 and then Present (Renamed_Object (Entity (N)))
7269 then
7270 return
7271 Possible_Bit_Aligned_Component (Renamed_Object (Entity (N)));
7272 else
7273 return False;
7274 end if;
7275
7276 end case;
7277 end Possible_Bit_Aligned_Component;
7278
7279 -----------------------------------------------
7280 -- Process_Statements_For_Controlled_Objects --
7281 -----------------------------------------------
7282
7283 procedure Process_Statements_For_Controlled_Objects (N : Node_Id) is
7284 Loc : constant Source_Ptr := Sloc (N);
7285
7286 function Are_Wrapped (L : List_Id) return Boolean;
7287 -- Determine whether list L contains only one statement which is a block
7288
7289 function Wrap_Statements_In_Block
7290 (L : List_Id;
7291 Scop : Entity_Id := Current_Scope) return Node_Id;
7292 -- Given a list of statements L, wrap it in a block statement and return
7293 -- the generated node. Scop is either the current scope or the scope of
7294 -- the context (if applicable).
7295
7296 -----------------
7297 -- Are_Wrapped --
7298 -----------------
7299
7300 function Are_Wrapped (L : List_Id) return Boolean is
7301 Stmt : constant Node_Id := First (L);
7302 begin
7303 return
7304 Present (Stmt)
7305 and then No (Next (Stmt))
7306 and then Nkind (Stmt) = N_Block_Statement;
7307 end Are_Wrapped;
7308
7309 ------------------------------
7310 -- Wrap_Statements_In_Block --
7311 ------------------------------
7312
7313 function Wrap_Statements_In_Block
7314 (L : List_Id;
7315 Scop : Entity_Id := Current_Scope) return Node_Id
7316 is
7317 Block_Id : Entity_Id;
7318 Block_Nod : Node_Id;
7319 Iter_Loop : Entity_Id;
7320
7321 begin
7322 Block_Nod :=
7323 Make_Block_Statement (Loc,
7324 Declarations => No_List,
7325 Handled_Statement_Sequence =>
7326 Make_Handled_Sequence_Of_Statements (Loc,
7327 Statements => L));
7328
7329 -- Create a label for the block in case the block needs to manage the
7330 -- secondary stack. A label allows for flag Uses_Sec_Stack to be set.
7331
7332 Add_Block_Identifier (Block_Nod, Block_Id);
7333
7334 -- When wrapping the statements of an iterator loop, check whether
7335 -- the loop requires secondary stack management and if so, propagate
7336 -- the appropriate flags to the block. This ensures that the cursor
7337 -- is properly cleaned up at each iteration of the loop.
7338
7339 Iter_Loop := Find_Enclosing_Iterator_Loop (Scop);
7340
7341 if Present (Iter_Loop) then
7342 Set_Uses_Sec_Stack (Block_Id, Uses_Sec_Stack (Iter_Loop));
7343
7344 -- Secondary stack reclamation is suppressed when the associated
7345 -- iterator loop contains a return statement which uses the stack.
7346
7347 Set_Sec_Stack_Needed_For_Return
7348 (Block_Id, Sec_Stack_Needed_For_Return (Iter_Loop));
7349 end if;
7350
7351 return Block_Nod;
7352 end Wrap_Statements_In_Block;
7353
7354 -- Local variables
7355
7356 Block : Node_Id;
7357
7358 -- Start of processing for Process_Statements_For_Controlled_Objects
7359
7360 begin
7361 -- Whenever a non-handled statement list is wrapped in a block, the
7362 -- block must be explicitly analyzed to redecorate all entities in the
7363 -- list and ensure that a finalizer is properly built.
7364
7365 case Nkind (N) is
7366 when N_Elsif_Part |
7367 N_If_Statement |
7368 N_Conditional_Entry_Call |
7369 N_Selective_Accept =>
7370
7371 -- Check the "then statements" for elsif parts and if statements
7372
7373 if Nkind_In (N, N_Elsif_Part, N_If_Statement)
7374 and then not Is_Empty_List (Then_Statements (N))
7375 and then not Are_Wrapped (Then_Statements (N))
7376 and then Requires_Cleanup_Actions
7377 (Then_Statements (N), False, False)
7378 then
7379 Block := Wrap_Statements_In_Block (Then_Statements (N));
7380 Set_Then_Statements (N, New_List (Block));
7381
7382 Analyze (Block);
7383 end if;
7384
7385 -- Check the "else statements" for conditional entry calls, if
7386 -- statements and selective accepts.
7387
7388 if Nkind_In (N, N_Conditional_Entry_Call,
7389 N_If_Statement,
7390 N_Selective_Accept)
7391 and then not Is_Empty_List (Else_Statements (N))
7392 and then not Are_Wrapped (Else_Statements (N))
7393 and then Requires_Cleanup_Actions
7394 (Else_Statements (N), False, False)
7395 then
7396 Block := Wrap_Statements_In_Block (Else_Statements (N));
7397 Set_Else_Statements (N, New_List (Block));
7398
7399 Analyze (Block);
7400 end if;
7401
7402 when N_Abortable_Part |
7403 N_Accept_Alternative |
7404 N_Case_Statement_Alternative |
7405 N_Delay_Alternative |
7406 N_Entry_Call_Alternative |
7407 N_Exception_Handler |
7408 N_Loop_Statement |
7409 N_Triggering_Alternative =>
7410
7411 if not Is_Empty_List (Statements (N))
7412 and then not Are_Wrapped (Statements (N))
7413 and then Requires_Cleanup_Actions (Statements (N), False, False)
7414 then
7415 if Nkind (N) = N_Loop_Statement
7416 and then Present (Identifier (N))
7417 then
7418 Block :=
7419 Wrap_Statements_In_Block
7420 (L => Statements (N),
7421 Scop => Entity (Identifier (N)));
7422 else
7423 Block := Wrap_Statements_In_Block (Statements (N));
7424 end if;
7425
7426 Set_Statements (N, New_List (Block));
7427 Analyze (Block);
7428 end if;
7429
7430 when others =>
7431 null;
7432 end case;
7433 end Process_Statements_For_Controlled_Objects;
7434
7435 ------------------
7436 -- Power_Of_Two --
7437 ------------------
7438
7439 function Power_Of_Two (N : Node_Id) return Nat is
7440 Typ : constant Entity_Id := Etype (N);
7441 pragma Assert (Is_Integer_Type (Typ));
7442
7443 Siz : constant Nat := UI_To_Int (Esize (Typ));
7444 Val : Uint;
7445
7446 begin
7447 if not Compile_Time_Known_Value (N) then
7448 return 0;
7449
7450 else
7451 Val := Expr_Value (N);
7452 for J in 1 .. Siz - 1 loop
7453 if Val = Uint_2 ** J then
7454 return J;
7455 end if;
7456 end loop;
7457
7458 return 0;
7459 end if;
7460 end Power_Of_Two;
7461
7462 ----------------------
7463 -- Remove_Init_Call --
7464 ----------------------
7465
7466 function Remove_Init_Call
7467 (Var : Entity_Id;
7468 Rep_Clause : Node_Id) return Node_Id
7469 is
7470 Par : constant Node_Id := Parent (Var);
7471 Typ : constant Entity_Id := Etype (Var);
7472
7473 Init_Proc : Entity_Id;
7474 -- Initialization procedure for Typ
7475
7476 function Find_Init_Call_In_List (From : Node_Id) return Node_Id;
7477 -- Look for init call for Var starting at From and scanning the
7478 -- enclosing list until Rep_Clause or the end of the list is reached.
7479
7480 ----------------------------
7481 -- Find_Init_Call_In_List --
7482 ----------------------------
7483
7484 function Find_Init_Call_In_List (From : Node_Id) return Node_Id is
7485 Init_Call : Node_Id;
7486
7487 begin
7488 Init_Call := From;
7489 while Present (Init_Call) and then Init_Call /= Rep_Clause loop
7490 if Nkind (Init_Call) = N_Procedure_Call_Statement
7491 and then Is_Entity_Name (Name (Init_Call))
7492 and then Entity (Name (Init_Call)) = Init_Proc
7493 then
7494 return Init_Call;
7495 end if;
7496
7497 Next (Init_Call);
7498 end loop;
7499
7500 return Empty;
7501 end Find_Init_Call_In_List;
7502
7503 Init_Call : Node_Id;
7504
7505 -- Start of processing for Find_Init_Call
7506
7507 begin
7508 if Present (Initialization_Statements (Var)) then
7509 Init_Call := Initialization_Statements (Var);
7510 Set_Initialization_Statements (Var, Empty);
7511
7512 elsif not Has_Non_Null_Base_Init_Proc (Typ) then
7513
7514 -- No init proc for the type, so obviously no call to be found
7515
7516 return Empty;
7517
7518 else
7519 -- We might be able to handle other cases below by just properly
7520 -- setting Initialization_Statements at the point where the init proc
7521 -- call is generated???
7522
7523 Init_Proc := Base_Init_Proc (Typ);
7524
7525 -- First scan the list containing the declaration of Var
7526
7527 Init_Call := Find_Init_Call_In_List (From => Next (Par));
7528
7529 -- If not found, also look on Var's freeze actions list, if any,
7530 -- since the init call may have been moved there (case of an address
7531 -- clause applying to Var).
7532
7533 if No (Init_Call) and then Present (Freeze_Node (Var)) then
7534 Init_Call :=
7535 Find_Init_Call_In_List (First (Actions (Freeze_Node (Var))));
7536 end if;
7537
7538 -- If the initialization call has actuals that use the secondary
7539 -- stack, the call may have been wrapped into a temporary block, in
7540 -- which case the block itself has to be removed.
7541
7542 if No (Init_Call) and then Nkind (Next (Par)) = N_Block_Statement then
7543 declare
7544 Blk : constant Node_Id := Next (Par);
7545 begin
7546 if Present
7547 (Find_Init_Call_In_List
7548 (First (Statements (Handled_Statement_Sequence (Blk)))))
7549 then
7550 Init_Call := Blk;
7551 end if;
7552 end;
7553 end if;
7554 end if;
7555
7556 if Present (Init_Call) then
7557 Remove (Init_Call);
7558 end if;
7559 return Init_Call;
7560 end Remove_Init_Call;
7561
7562 -------------------------
7563 -- Remove_Side_Effects --
7564 -------------------------
7565
7566 procedure Remove_Side_Effects
7567 (Exp : Node_Id;
7568 Name_Req : Boolean := False;
7569 Renaming_Req : Boolean := False;
7570 Variable_Ref : Boolean := False;
7571 Related_Id : Entity_Id := Empty;
7572 Is_Low_Bound : Boolean := False;
7573 Is_High_Bound : Boolean := False;
7574 Check_Side_Effects : Boolean := True)
7575 is
7576 function Build_Temporary
7577 (Loc : Source_Ptr;
7578 Id : Character;
7579 Related_Nod : Node_Id := Empty) return Entity_Id;
7580 -- Create an external symbol of the form xxx_FIRST/_LAST if Related_Nod
7581 -- is present (xxx is taken from the Chars field of Related_Nod),
7582 -- otherwise it generates an internal temporary.
7583
7584 function Is_Name_Reference (N : Node_Id) return Boolean;
7585 -- Determine if the tree referenced by N represents a name. This is
7586 -- similar to Is_Object_Reference but returns true only if N can be
7587 -- renamed without the need for a temporary, the typical example of
7588 -- an object not in this category being a function call.
7589
7590 ---------------------
7591 -- Build_Temporary --
7592 ---------------------
7593
7594 function Build_Temporary
7595 (Loc : Source_Ptr;
7596 Id : Character;
7597 Related_Nod : Node_Id := Empty) return Entity_Id
7598 is
7599 Temp_Nam : Name_Id;
7600
7601 begin
7602 -- The context requires an external symbol
7603
7604 if Present (Related_Id) then
7605 if Is_Low_Bound then
7606 Temp_Nam := New_External_Name (Chars (Related_Id), "_FIRST");
7607 else pragma Assert (Is_High_Bound);
7608 Temp_Nam := New_External_Name (Chars (Related_Id), "_LAST");
7609 end if;
7610
7611 return Make_Defining_Identifier (Loc, Temp_Nam);
7612
7613 -- Otherwise generate an internal temporary
7614
7615 else
7616 return Make_Temporary (Loc, Id, Related_Nod);
7617 end if;
7618 end Build_Temporary;
7619
7620 -----------------------
7621 -- Is_Name_Reference --
7622 -----------------------
7623
7624 function Is_Name_Reference (N : Node_Id) return Boolean is
7625 begin
7626 if Is_Entity_Name (N) then
7627 return Present (Entity (N)) and then Is_Object (Entity (N));
7628 end if;
7629
7630 case Nkind (N) is
7631 when N_Indexed_Component | N_Slice =>
7632 return
7633 Is_Name_Reference (Prefix (N))
7634 or else Is_Access_Type (Etype (Prefix (N)));
7635
7636 -- Attributes 'Input, 'Old and 'Result produce objects
7637
7638 when N_Attribute_Reference =>
7639 return
7640 Nam_In
7641 (Attribute_Name (N), Name_Input, Name_Old, Name_Result);
7642
7643 when N_Selected_Component =>
7644 return
7645 Is_Name_Reference (Selector_Name (N))
7646 and then
7647 (Is_Name_Reference (Prefix (N))
7648 or else Is_Access_Type (Etype (Prefix (N))));
7649
7650 when N_Explicit_Dereference =>
7651 return True;
7652
7653 -- A view conversion of a tagged name is a name reference
7654
7655 when N_Type_Conversion =>
7656 return Is_Tagged_Type (Etype (Subtype_Mark (N)))
7657 and then Is_Tagged_Type (Etype (Expression (N)))
7658 and then Is_Name_Reference (Expression (N));
7659
7660 -- An unchecked type conversion is considered to be a name if
7661 -- the operand is a name (this construction arises only as a
7662 -- result of expansion activities).
7663
7664 when N_Unchecked_Type_Conversion =>
7665 return Is_Name_Reference (Expression (N));
7666
7667 when others =>
7668 return False;
7669 end case;
7670 end Is_Name_Reference;
7671
7672 -- Local variables
7673
7674 Loc : constant Source_Ptr := Sloc (Exp);
7675 Exp_Type : constant Entity_Id := Etype (Exp);
7676 Svg_Suppress : constant Suppress_Record := Scope_Suppress;
7677 Def_Id : Entity_Id;
7678 E : Node_Id;
7679 New_Exp : Node_Id;
7680 Ptr_Typ_Decl : Node_Id;
7681 Ref_Type : Entity_Id;
7682 Res : Node_Id;
7683
7684 -- Start of processing for Remove_Side_Effects
7685
7686 begin
7687 -- Handle cases in which there is nothing to do. In GNATprove mode,
7688 -- removal of side effects is useful for the light expansion of
7689 -- renamings. This removal should only occur when not inside a
7690 -- generic and not doing a pre-analysis.
7691
7692 if not Expander_Active
7693 and (Inside_A_Generic or not Full_Analysis or not GNATprove_Mode)
7694 then
7695 return;
7696
7697 -- Cannot generate temporaries if the invocation to remove side effects
7698 -- was issued too early and the type of the expression is not resolved
7699 -- (this happens because routines Duplicate_Subexpr_XX implicitly invoke
7700 -- Remove_Side_Effects).
7701
7702 elsif No (Exp_Type)
7703 or else Ekind (Exp_Type) = E_Access_Attribute_Type
7704 then
7705 return;
7706
7707 -- Nothing to do if prior expansion determined that a function call does
7708 -- not require side effect removal.
7709
7710 elsif Nkind (Exp) = N_Function_Call
7711 and then No_Side_Effect_Removal (Exp)
7712 then
7713 return;
7714
7715 -- No action needed for side-effect free expressions
7716
7717 elsif Check_Side_Effects
7718 and then Side_Effect_Free (Exp, Name_Req, Variable_Ref)
7719 then
7720 return;
7721 end if;
7722
7723 -- The remaining processing is done with all checks suppressed
7724
7725 -- Note: from now on, don't use return statements, instead do a goto
7726 -- Leave, to ensure that we properly restore Scope_Suppress.Suppress.
7727
7728 Scope_Suppress.Suppress := (others => True);
7729
7730 -- If this is an elementary or a small not-by-reference record type, and
7731 -- we need to capture the value, just make a constant; this is cheap and
7732 -- objects of both kinds of types can be bit aligned, so it might not be
7733 -- possible to generate a reference to them. Likewise if this is not a
7734 -- name reference, except for a type conversion, because we would enter
7735 -- an infinite recursion with Checks.Apply_Predicate_Check if the target
7736 -- type has predicates (and type conversions need a specific treatment
7737 -- anyway, see below). Also do it if we have a volatile reference and
7738 -- Name_Req is not set (see comments for Side_Effect_Free).
7739
7740 if (Is_Elementary_Type (Exp_Type)
7741 or else (Is_Record_Type (Exp_Type)
7742 and then Known_Static_RM_Size (Exp_Type)
7743 and then RM_Size (Exp_Type) <= 64
7744 and then not Has_Discriminants (Exp_Type)
7745 and then not Is_By_Reference_Type (Exp_Type)))
7746 and then (Variable_Ref
7747 or else (not Is_Name_Reference (Exp)
7748 and then Nkind (Exp) /= N_Type_Conversion)
7749 or else (not Name_Req
7750 and then Is_Volatile_Reference (Exp)))
7751 then
7752 Def_Id := Build_Temporary (Loc, 'R', Exp);
7753 Set_Etype (Def_Id, Exp_Type);
7754 Res := New_Occurrence_Of (Def_Id, Loc);
7755
7756 -- If the expression is a packed reference, it must be reanalyzed and
7757 -- expanded, depending on context. This is the case for actuals where
7758 -- a constraint check may capture the actual before expansion of the
7759 -- call is complete.
7760
7761 if Nkind (Exp) = N_Indexed_Component
7762 and then Is_Packed (Etype (Prefix (Exp)))
7763 then
7764 Set_Analyzed (Exp, False);
7765 Set_Analyzed (Prefix (Exp), False);
7766 end if;
7767
7768 -- Generate:
7769 -- Rnn : Exp_Type renames Expr;
7770
7771 if Renaming_Req then
7772 E :=
7773 Make_Object_Renaming_Declaration (Loc,
7774 Defining_Identifier => Def_Id,
7775 Subtype_Mark => New_Occurrence_Of (Exp_Type, Loc),
7776 Name => Relocate_Node (Exp));
7777
7778 -- Generate:
7779 -- Rnn : constant Exp_Type := Expr;
7780
7781 else
7782 E :=
7783 Make_Object_Declaration (Loc,
7784 Defining_Identifier => Def_Id,
7785 Object_Definition => New_Occurrence_Of (Exp_Type, Loc),
7786 Constant_Present => True,
7787 Expression => Relocate_Node (Exp));
7788
7789 Set_Assignment_OK (E);
7790 end if;
7791
7792 Insert_Action (Exp, E);
7793
7794 -- If the expression has the form v.all then we can just capture the
7795 -- pointer, and then do an explicit dereference on the result, but
7796 -- this is not right if this is a volatile reference.
7797
7798 elsif Nkind (Exp) = N_Explicit_Dereference
7799 and then not Is_Volatile_Reference (Exp)
7800 then
7801 Def_Id := Build_Temporary (Loc, 'R', Exp);
7802 Res :=
7803 Make_Explicit_Dereference (Loc, New_Occurrence_Of (Def_Id, Loc));
7804
7805 Insert_Action (Exp,
7806 Make_Object_Declaration (Loc,
7807 Defining_Identifier => Def_Id,
7808 Object_Definition =>
7809 New_Occurrence_Of (Etype (Prefix (Exp)), Loc),
7810 Constant_Present => True,
7811 Expression => Relocate_Node (Prefix (Exp))));
7812
7813 -- Similar processing for an unchecked conversion of an expression of
7814 -- the form v.all, where we want the same kind of treatment.
7815
7816 elsif Nkind (Exp) = N_Unchecked_Type_Conversion
7817 and then Nkind (Expression (Exp)) = N_Explicit_Dereference
7818 then
7819 Remove_Side_Effects (Expression (Exp), Name_Req, Variable_Ref);
7820 goto Leave;
7821
7822 -- If this is a type conversion, leave the type conversion and remove
7823 -- the side effects in the expression. This is important in several
7824 -- circumstances: for change of representations, and also when this is a
7825 -- view conversion to a smaller object, where gigi can end up creating
7826 -- its own temporary of the wrong size.
7827
7828 elsif Nkind (Exp) = N_Type_Conversion then
7829 Remove_Side_Effects (Expression (Exp), Name_Req, Variable_Ref);
7830
7831 -- Generating C code the type conversion of an access to constrained
7832 -- array type into an access to unconstrained array type involves
7833 -- initializing a fat pointer and the expression must be free of
7834 -- side effects to safely compute its bounds.
7835
7836 if Generate_C_Code
7837 and then Is_Access_Type (Etype (Exp))
7838 and then Is_Array_Type (Designated_Type (Etype (Exp)))
7839 and then not Is_Constrained (Designated_Type (Etype (Exp)))
7840 then
7841 Def_Id := Build_Temporary (Loc, 'R', Exp);
7842 Set_Etype (Def_Id, Exp_Type);
7843 Res := New_Occurrence_Of (Def_Id, Loc);
7844
7845 Insert_Action (Exp,
7846 Make_Object_Declaration (Loc,
7847 Defining_Identifier => Def_Id,
7848 Object_Definition => New_Occurrence_Of (Exp_Type, Loc),
7849 Constant_Present => True,
7850 Expression => Relocate_Node (Exp)));
7851 else
7852 goto Leave;
7853 end if;
7854
7855 -- If this is an unchecked conversion that Gigi can't handle, make
7856 -- a copy or a use a renaming to capture the value.
7857
7858 elsif Nkind (Exp) = N_Unchecked_Type_Conversion
7859 and then not Safe_Unchecked_Type_Conversion (Exp)
7860 then
7861 if CW_Or_Has_Controlled_Part (Exp_Type) then
7862
7863 -- Use a renaming to capture the expression, rather than create
7864 -- a controlled temporary.
7865
7866 Def_Id := Build_Temporary (Loc, 'R', Exp);
7867 Res := New_Occurrence_Of (Def_Id, Loc);
7868
7869 Insert_Action (Exp,
7870 Make_Object_Renaming_Declaration (Loc,
7871 Defining_Identifier => Def_Id,
7872 Subtype_Mark => New_Occurrence_Of (Exp_Type, Loc),
7873 Name => Relocate_Node (Exp)));
7874
7875 else
7876 Def_Id := Build_Temporary (Loc, 'R', Exp);
7877 Set_Etype (Def_Id, Exp_Type);
7878 Res := New_Occurrence_Of (Def_Id, Loc);
7879
7880 E :=
7881 Make_Object_Declaration (Loc,
7882 Defining_Identifier => Def_Id,
7883 Object_Definition => New_Occurrence_Of (Exp_Type, Loc),
7884 Constant_Present => not Is_Variable (Exp),
7885 Expression => Relocate_Node (Exp));
7886
7887 Set_Assignment_OK (E);
7888 Insert_Action (Exp, E);
7889 end if;
7890
7891 -- For expressions that denote names, we can use a renaming scheme.
7892 -- This is needed for correctness in the case of a volatile object of
7893 -- a non-volatile type because the Make_Reference call of the "default"
7894 -- approach would generate an illegal access value (an access value
7895 -- cannot designate such an object - see Analyze_Reference).
7896
7897 elsif Is_Name_Reference (Exp)
7898
7899 -- We skip using this scheme if we have an object of a volatile
7900 -- type and we do not have Name_Req set true (see comments for
7901 -- Side_Effect_Free).
7902
7903 and then (Name_Req or else not Treat_As_Volatile (Exp_Type))
7904 then
7905 Def_Id := Build_Temporary (Loc, 'R', Exp);
7906 Res := New_Occurrence_Of (Def_Id, Loc);
7907
7908 Insert_Action (Exp,
7909 Make_Object_Renaming_Declaration (Loc,
7910 Defining_Identifier => Def_Id,
7911 Subtype_Mark => New_Occurrence_Of (Exp_Type, Loc),
7912 Name => Relocate_Node (Exp)));
7913
7914 -- If this is a packed reference, or a selected component with
7915 -- a non-standard representation, a reference to the temporary
7916 -- will be replaced by a copy of the original expression (see
7917 -- Exp_Ch2.Expand_Renaming). Otherwise the temporary must be
7918 -- elaborated by gigi, and is of course not to be replaced in-line
7919 -- by the expression it renames, which would defeat the purpose of
7920 -- removing the side-effect.
7921
7922 if Nkind_In (Exp, N_Selected_Component, N_Indexed_Component)
7923 and then Has_Non_Standard_Rep (Etype (Prefix (Exp)))
7924 then
7925 null;
7926 else
7927 Set_Is_Renaming_Of_Object (Def_Id, False);
7928 end if;
7929
7930 -- Avoid generating a variable-sized temporary, by generating the
7931 -- reference just for the function call. The transformation could be
7932 -- refined to apply only when the array component is constrained by a
7933 -- discriminant???
7934
7935 elsif Nkind (Exp) = N_Selected_Component
7936 and then Nkind (Prefix (Exp)) = N_Function_Call
7937 and then Is_Array_Type (Exp_Type)
7938 then
7939 Remove_Side_Effects (Prefix (Exp), Name_Req, Variable_Ref);
7940 goto Leave;
7941
7942 -- Otherwise we generate a reference to the expression
7943
7944 else
7945 -- An expression which is in SPARK mode is considered side effect
7946 -- free if the resulting value is captured by a variable or a
7947 -- constant.
7948
7949 if GNATprove_Mode
7950 and then Nkind (Parent (Exp)) = N_Object_Declaration
7951 then
7952 goto Leave;
7953
7954 -- When generating C code we cannot consider side effect free object
7955 -- declarations that have discriminants and are initialized by means
7956 -- of a function call since on this target there is no secondary
7957 -- stack to store the return value and the expander may generate an
7958 -- extra call to the function to compute the discriminant value. In
7959 -- addition, for targets that have secondary stack, the expansion of
7960 -- functions with side effects involves the generation of an access
7961 -- type to capture the return value stored in the secondary stack;
7962 -- by contrast when generating C code such expansion generates an
7963 -- internal object declaration (no access type involved) which must
7964 -- be identified here to avoid entering into a never-ending loop
7965 -- generating internal object declarations.
7966
7967 elsif Generate_C_Code
7968 and then Nkind (Parent (Exp)) = N_Object_Declaration
7969 and then
7970 (Nkind (Exp) /= N_Function_Call
7971 or else not Has_Discriminants (Exp_Type)
7972 or else Is_Internal_Name
7973 (Chars (Defining_Identifier (Parent (Exp)))))
7974 then
7975 goto Leave;
7976 end if;
7977
7978 -- Special processing for function calls that return a limited type.
7979 -- We need to build a declaration that will enable build-in-place
7980 -- expansion of the call. This is not done if the context is already
7981 -- an object declaration, to prevent infinite recursion.
7982
7983 -- This is relevant only in Ada 2005 mode. In Ada 95 programs we have
7984 -- to accommodate functions returning limited objects by reference.
7985
7986 if Ada_Version >= Ada_2005
7987 and then Nkind (Exp) = N_Function_Call
7988 and then Is_Limited_View (Etype (Exp))
7989 and then Nkind (Parent (Exp)) /= N_Object_Declaration
7990 then
7991 declare
7992 Obj : constant Entity_Id := Make_Temporary (Loc, 'F', Exp);
7993 Decl : Node_Id;
7994
7995 begin
7996 Decl :=
7997 Make_Object_Declaration (Loc,
7998 Defining_Identifier => Obj,
7999 Object_Definition => New_Occurrence_Of (Exp_Type, Loc),
8000 Expression => Relocate_Node (Exp));
8001
8002 Insert_Action (Exp, Decl);
8003 Set_Etype (Obj, Exp_Type);
8004 Rewrite (Exp, New_Occurrence_Of (Obj, Loc));
8005 goto Leave;
8006 end;
8007 end if;
8008
8009 Def_Id := Build_Temporary (Loc, 'R', Exp);
8010
8011 -- The regular expansion of functions with side effects involves the
8012 -- generation of an access type to capture the return value found on
8013 -- the secondary stack. Since SPARK (and why) cannot process access
8014 -- types, use a different approach which ignores the secondary stack
8015 -- and "copies" the returned object.
8016 -- When generating C code, no need for a 'reference since the
8017 -- secondary stack is not supported.
8018
8019 if GNATprove_Mode or Generate_C_Code then
8020 Res := New_Occurrence_Of (Def_Id, Loc);
8021 Ref_Type := Exp_Type;
8022
8023 -- Regular expansion utilizing an access type and 'reference
8024
8025 else
8026 Res :=
8027 Make_Explicit_Dereference (Loc,
8028 Prefix => New_Occurrence_Of (Def_Id, Loc));
8029
8030 -- Generate:
8031 -- type Ann is access all <Exp_Type>;
8032
8033 Ref_Type := Make_Temporary (Loc, 'A');
8034
8035 Ptr_Typ_Decl :=
8036 Make_Full_Type_Declaration (Loc,
8037 Defining_Identifier => Ref_Type,
8038 Type_Definition =>
8039 Make_Access_To_Object_Definition (Loc,
8040 All_Present => True,
8041 Subtype_Indication =>
8042 New_Occurrence_Of (Exp_Type, Loc)));
8043
8044 Insert_Action (Exp, Ptr_Typ_Decl);
8045 end if;
8046
8047 E := Exp;
8048 if Nkind (E) = N_Explicit_Dereference then
8049 New_Exp := Relocate_Node (Prefix (E));
8050
8051 else
8052 E := Relocate_Node (E);
8053
8054 -- Do not generate a 'reference in SPARK mode or C generation
8055 -- since the access type is not created in the first place.
8056
8057 if GNATprove_Mode or Generate_C_Code then
8058 New_Exp := E;
8059
8060 -- Otherwise generate reference, marking the value as non-null
8061 -- since we know it cannot be null and we don't want a check.
8062
8063 else
8064 New_Exp := Make_Reference (Loc, E);
8065 Set_Is_Known_Non_Null (Def_Id);
8066 end if;
8067 end if;
8068
8069 if Is_Delayed_Aggregate (E) then
8070
8071 -- The expansion of nested aggregates is delayed until the
8072 -- enclosing aggregate is expanded. As aggregates are often
8073 -- qualified, the predicate applies to qualified expressions as
8074 -- well, indicating that the enclosing aggregate has not been
8075 -- expanded yet. At this point the aggregate is part of a
8076 -- stand-alone declaration, and must be fully expanded.
8077
8078 if Nkind (E) = N_Qualified_Expression then
8079 Set_Expansion_Delayed (Expression (E), False);
8080 Set_Analyzed (Expression (E), False);
8081 else
8082 Set_Expansion_Delayed (E, False);
8083 end if;
8084
8085 Set_Analyzed (E, False);
8086 end if;
8087
8088 -- Generating C code of object declarations that have discriminants
8089 -- and are initialized by means of a function call we propagate the
8090 -- discriminants of the parent type to the internally built object.
8091 -- This is needed to avoid generating an extra call to the called
8092 -- function.
8093
8094 -- For example, if we generate here the following declaration, it
8095 -- will be expanded later adding an extra call to evaluate the value
8096 -- of the discriminant (needed to compute the size of the object).
8097 --
8098 -- type Rec (D : Integer) is ...
8099 -- Obj : constant Rec := SomeFunc;
8100
8101 if Generate_C_Code
8102 and then Nkind (Parent (Exp)) = N_Object_Declaration
8103 and then Has_Discriminants (Exp_Type)
8104 and then Nkind (Exp) = N_Function_Call
8105 then
8106 Insert_Action (Exp,
8107 Make_Object_Declaration (Loc,
8108 Defining_Identifier => Def_Id,
8109 Object_Definition => New_Copy_Tree
8110 (Object_Definition (Parent (Exp))),
8111 Constant_Present => True,
8112 Expression => New_Exp));
8113 else
8114 Insert_Action (Exp,
8115 Make_Object_Declaration (Loc,
8116 Defining_Identifier => Def_Id,
8117 Object_Definition => New_Occurrence_Of (Ref_Type, Loc),
8118 Constant_Present => True,
8119 Expression => New_Exp));
8120 end if;
8121 end if;
8122
8123 -- Preserve the Assignment_OK flag in all copies, since at least one
8124 -- copy may be used in a context where this flag must be set (otherwise
8125 -- why would the flag be set in the first place).
8126
8127 Set_Assignment_OK (Res, Assignment_OK (Exp));
8128
8129 -- Finally rewrite the original expression and we are done
8130
8131 Rewrite (Exp, Res);
8132 Analyze_And_Resolve (Exp, Exp_Type);
8133
8134 <<Leave>>
8135 Scope_Suppress := Svg_Suppress;
8136 end Remove_Side_Effects;
8137
8138 ---------------------------
8139 -- Represented_As_Scalar --
8140 ---------------------------
8141
8142 function Represented_As_Scalar (T : Entity_Id) return Boolean is
8143 UT : constant Entity_Id := Underlying_Type (T);
8144 begin
8145 return Is_Scalar_Type (UT)
8146 or else (Is_Bit_Packed_Array (UT)
8147 and then Is_Scalar_Type (Packed_Array_Impl_Type (UT)));
8148 end Represented_As_Scalar;
8149
8150 ------------------------------
8151 -- Requires_Cleanup_Actions --
8152 ------------------------------
8153
8154 function Requires_Cleanup_Actions
8155 (N : Node_Id;
8156 Lib_Level : Boolean) return Boolean
8157 is
8158 At_Lib_Level : constant Boolean :=
8159 Lib_Level
8160 and then Nkind_In (N, N_Package_Body,
8161 N_Package_Specification);
8162 -- N is at the library level if the top-most context is a package and
8163 -- the path taken to reach N does not inlcude non-package constructs.
8164
8165 begin
8166 case Nkind (N) is
8167 when N_Accept_Statement |
8168 N_Block_Statement |
8169 N_Entry_Body |
8170 N_Package_Body |
8171 N_Protected_Body |
8172 N_Subprogram_Body |
8173 N_Task_Body =>
8174 return
8175 Requires_Cleanup_Actions (Declarations (N), At_Lib_Level, True)
8176 or else
8177 (Present (Handled_Statement_Sequence (N))
8178 and then
8179 Requires_Cleanup_Actions
8180 (Statements (Handled_Statement_Sequence (N)),
8181 At_Lib_Level, True));
8182
8183 when N_Package_Specification =>
8184 return
8185 Requires_Cleanup_Actions
8186 (Visible_Declarations (N), At_Lib_Level, True)
8187 or else
8188 Requires_Cleanup_Actions
8189 (Private_Declarations (N), At_Lib_Level, True);
8190
8191 when others =>
8192 return False;
8193 end case;
8194 end Requires_Cleanup_Actions;
8195
8196 ------------------------------
8197 -- Requires_Cleanup_Actions --
8198 ------------------------------
8199
8200 function Requires_Cleanup_Actions
8201 (L : List_Id;
8202 Lib_Level : Boolean;
8203 Nested_Constructs : Boolean) return Boolean
8204 is
8205 Decl : Node_Id;
8206 Expr : Node_Id;
8207 Obj_Id : Entity_Id;
8208 Obj_Typ : Entity_Id;
8209 Pack_Id : Entity_Id;
8210 Typ : Entity_Id;
8211
8212 begin
8213 if No (L)
8214 or else Is_Empty_List (L)
8215 then
8216 return False;
8217 end if;
8218
8219 Decl := First (L);
8220 while Present (Decl) loop
8221
8222 -- Library-level tagged types
8223
8224 if Nkind (Decl) = N_Full_Type_Declaration then
8225 Typ := Defining_Identifier (Decl);
8226
8227 -- Ignored Ghost types do not need any cleanup actions because
8228 -- they will not appear in the final tree.
8229
8230 if Is_Ignored_Ghost_Entity (Typ) then
8231 null;
8232
8233 elsif Is_Tagged_Type (Typ)
8234 and then Is_Library_Level_Entity (Typ)
8235 and then Convention (Typ) = Convention_Ada
8236 and then Present (Access_Disp_Table (Typ))
8237 and then RTE_Available (RE_Unregister_Tag)
8238 and then not Is_Abstract_Type (Typ)
8239 and then not No_Run_Time_Mode
8240 then
8241 return True;
8242 end if;
8243
8244 -- Regular object declarations
8245
8246 elsif Nkind (Decl) = N_Object_Declaration then
8247 Obj_Id := Defining_Identifier (Decl);
8248 Obj_Typ := Base_Type (Etype (Obj_Id));
8249 Expr := Expression (Decl);
8250
8251 -- Bypass any form of processing for objects which have their
8252 -- finalization disabled. This applies only to objects at the
8253 -- library level.
8254
8255 if Lib_Level and then Finalize_Storage_Only (Obj_Typ) then
8256 null;
8257
8258 -- Transient variables are treated separately in order to minimize
8259 -- the size of the generated code. See Exp_Ch7.Process_Transient_
8260 -- Objects.
8261
8262 elsif Is_Processed_Transient (Obj_Id) then
8263 null;
8264
8265 -- Ignored Ghost objects do not need any cleanup actions because
8266 -- they will not appear in the final tree.
8267
8268 elsif Is_Ignored_Ghost_Entity (Obj_Id) then
8269 null;
8270
8271 -- The expansion of iterator loops generates an object declaration
8272 -- where the Ekind is explicitly set to loop parameter. This is to
8273 -- ensure that the loop parameter behaves as a constant from user
8274 -- code point of view. Such object are never controlled and do not
8275 -- require cleanup actions. An iterator loop over a container of
8276 -- controlled objects does not produce such object declarations.
8277
8278 elsif Ekind (Obj_Id) = E_Loop_Parameter then
8279 return False;
8280
8281 -- The object is of the form:
8282 -- Obj : [constant] Typ [:= Expr];
8283 --
8284 -- Do not process tag-to-class-wide conversions because they do
8285 -- not yield an object. Do not process the incomplete view of a
8286 -- deferred constant. Note that an object initialized by means
8287 -- of a build-in-place function call may appear as a deferred
8288 -- constant after expansion activities. These kinds of objects
8289 -- must be finalized.
8290
8291 elsif not Is_Imported (Obj_Id)
8292 and then Needs_Finalization (Obj_Typ)
8293 and then not Is_Tag_To_Class_Wide_Conversion (Obj_Id)
8294 and then not (Ekind (Obj_Id) = E_Constant
8295 and then not Has_Completion (Obj_Id)
8296 and then No (BIP_Initialization_Call (Obj_Id)))
8297 then
8298 return True;
8299
8300 -- The object is of the form:
8301 -- Obj : Access_Typ := Non_BIP_Function_Call'reference;
8302 --
8303 -- Obj : Access_Typ :=
8304 -- BIP_Function_Call (BIPalloc => 2, ...)'reference;
8305
8306 elsif Is_Access_Type (Obj_Typ)
8307 and then Needs_Finalization
8308 (Available_View (Designated_Type (Obj_Typ)))
8309 and then Present (Expr)
8310 and then
8311 (Is_Secondary_Stack_BIP_Func_Call (Expr)
8312 or else
8313 (Is_Non_BIP_Func_Call (Expr)
8314 and then not Is_Related_To_Func_Return (Obj_Id)))
8315 then
8316 return True;
8317
8318 -- Processing for "hook" objects generated for controlled
8319 -- transients declared inside an Expression_With_Actions.
8320
8321 elsif Is_Access_Type (Obj_Typ)
8322 and then Present (Status_Flag_Or_Transient_Decl (Obj_Id))
8323 and then Nkind (Status_Flag_Or_Transient_Decl (Obj_Id)) =
8324 N_Object_Declaration
8325 then
8326 return True;
8327
8328 -- Processing for intermediate results of if expressions where
8329 -- one of the alternatives uses a controlled function call.
8330
8331 elsif Is_Access_Type (Obj_Typ)
8332 and then Present (Status_Flag_Or_Transient_Decl (Obj_Id))
8333 and then Nkind (Status_Flag_Or_Transient_Decl (Obj_Id)) =
8334 N_Defining_Identifier
8335 and then Present (Expr)
8336 and then Nkind (Expr) = N_Null
8337 then
8338 return True;
8339
8340 -- Simple protected objects which use type System.Tasking.
8341 -- Protected_Objects.Protection to manage their locks should be
8342 -- treated as controlled since they require manual cleanup.
8343
8344 elsif Ekind (Obj_Id) = E_Variable
8345 and then (Is_Simple_Protected_Type (Obj_Typ)
8346 or else Has_Simple_Protected_Object (Obj_Typ))
8347 then
8348 return True;
8349 end if;
8350
8351 -- Specific cases of object renamings
8352
8353 elsif Nkind (Decl) = N_Object_Renaming_Declaration then
8354 Obj_Id := Defining_Identifier (Decl);
8355 Obj_Typ := Base_Type (Etype (Obj_Id));
8356
8357 -- Bypass any form of processing for objects which have their
8358 -- finalization disabled. This applies only to objects at the
8359 -- library level.
8360
8361 if Lib_Level and then Finalize_Storage_Only (Obj_Typ) then
8362 null;
8363
8364 -- Ignored Ghost object renamings do not need any cleanup actions
8365 -- because they will not appear in the final tree.
8366
8367 elsif Is_Ignored_Ghost_Entity (Obj_Id) then
8368 null;
8369
8370 -- Return object of a build-in-place function. This case is
8371 -- recognized and marked by the expansion of an extended return
8372 -- statement (see Expand_N_Extended_Return_Statement).
8373
8374 elsif Needs_Finalization (Obj_Typ)
8375 and then Is_Return_Object (Obj_Id)
8376 and then Present (Status_Flag_Or_Transient_Decl (Obj_Id))
8377 then
8378 return True;
8379
8380 -- Detect a case where a source object has been initialized by
8381 -- a controlled function call or another object which was later
8382 -- rewritten as a class-wide conversion of Ada.Tags.Displace.
8383
8384 -- Obj1 : CW_Type := Src_Obj;
8385 -- Obj2 : CW_Type := Function_Call (...);
8386
8387 -- Obj1 : CW_Type renames (... Ada.Tags.Displace (Src_Obj));
8388 -- Tmp : ... := Function_Call (...)'reference;
8389 -- Obj2 : CW_Type renames (... Ada.Tags.Displace (Tmp));
8390
8391 elsif Is_Displacement_Of_Object_Or_Function_Result (Obj_Id) then
8392 return True;
8393 end if;
8394
8395 -- Inspect the freeze node of an access-to-controlled type and look
8396 -- for a delayed finalization master. This case arises when the
8397 -- freeze actions are inserted at a later time than the expansion of
8398 -- the context. Since Build_Finalizer is never called on a single
8399 -- construct twice, the master will be ultimately left out and never
8400 -- finalized. This is also needed for freeze actions of designated
8401 -- types themselves, since in some cases the finalization master is
8402 -- associated with a designated type's freeze node rather than that
8403 -- of the access type (see handling for freeze actions in
8404 -- Build_Finalization_Master).
8405
8406 elsif Nkind (Decl) = N_Freeze_Entity
8407 and then Present (Actions (Decl))
8408 then
8409 Typ := Entity (Decl);
8410
8411 -- Freeze nodes for ignored Ghost types do not need cleanup
8412 -- actions because they will never appear in the final tree.
8413
8414 if Is_Ignored_Ghost_Entity (Typ) then
8415 null;
8416
8417 elsif ((Is_Access_Type (Typ)
8418 and then not Is_Access_Subprogram_Type (Typ)
8419 and then Needs_Finalization
8420 (Available_View (Designated_Type (Typ))))
8421 or else (Is_Type (Typ) and then Needs_Finalization (Typ)))
8422 and then Requires_Cleanup_Actions
8423 (Actions (Decl), Lib_Level, Nested_Constructs)
8424 then
8425 return True;
8426 end if;
8427
8428 -- Nested package declarations
8429
8430 elsif Nested_Constructs
8431 and then Nkind (Decl) = N_Package_Declaration
8432 then
8433 Pack_Id := Defining_Entity (Decl);
8434
8435 -- Do not inspect an ignored Ghost package because all code found
8436 -- within will not appear in the final tree.
8437
8438 if Is_Ignored_Ghost_Entity (Pack_Id) then
8439 null;
8440
8441 elsif Ekind (Pack_Id) /= E_Generic_Package
8442 and then Requires_Cleanup_Actions
8443 (Specification (Decl), Lib_Level)
8444 then
8445 return True;
8446 end if;
8447
8448 -- Nested package bodies
8449
8450 elsif Nested_Constructs and then Nkind (Decl) = N_Package_Body then
8451
8452 -- Do not inspect an ignored Ghost package body because all code
8453 -- found within will not appear in the final tree.
8454
8455 if Is_Ignored_Ghost_Entity (Defining_Entity (Decl)) then
8456 null;
8457
8458 elsif Ekind (Corresponding_Spec (Decl)) /= E_Generic_Package
8459 and then Requires_Cleanup_Actions (Decl, Lib_Level)
8460 then
8461 return True;
8462 end if;
8463
8464 elsif Nkind (Decl) = N_Block_Statement
8465 and then
8466
8467 -- Handle a rare case caused by a controlled transient variable
8468 -- created as part of a record init proc. The variable is wrapped
8469 -- in a block, but the block is not associated with a transient
8470 -- scope.
8471
8472 (Inside_Init_Proc
8473
8474 -- Handle the case where the original context has been wrapped in
8475 -- a block to avoid interference between exception handlers and
8476 -- At_End handlers. Treat the block as transparent and process its
8477 -- contents.
8478
8479 or else Is_Finalization_Wrapper (Decl))
8480 then
8481 if Requires_Cleanup_Actions (Decl, Lib_Level) then
8482 return True;
8483 end if;
8484 end if;
8485
8486 Next (Decl);
8487 end loop;
8488
8489 return False;
8490 end Requires_Cleanup_Actions;
8491
8492 ------------------------------------
8493 -- Safe_Unchecked_Type_Conversion --
8494 ------------------------------------
8495
8496 -- Note: this function knows quite a bit about the exact requirements of
8497 -- Gigi with respect to unchecked type conversions, and its code must be
8498 -- coordinated with any changes in Gigi in this area.
8499
8500 -- The above requirements should be documented in Sinfo ???
8501
8502 function Safe_Unchecked_Type_Conversion (Exp : Node_Id) return Boolean is
8503 Otyp : Entity_Id;
8504 Ityp : Entity_Id;
8505 Oalign : Uint;
8506 Ialign : Uint;
8507 Pexp : constant Node_Id := Parent (Exp);
8508
8509 begin
8510 -- If the expression is the RHS of an assignment or object declaration
8511 -- we are always OK because there will always be a target.
8512
8513 -- Object renaming declarations, (generated for view conversions of
8514 -- actuals in inlined calls), like object declarations, provide an
8515 -- explicit type, and are safe as well.
8516
8517 if (Nkind (Pexp) = N_Assignment_Statement
8518 and then Expression (Pexp) = Exp)
8519 or else Nkind_In (Pexp, N_Object_Declaration,
8520 N_Object_Renaming_Declaration)
8521 then
8522 return True;
8523
8524 -- If the expression is the prefix of an N_Selected_Component we should
8525 -- also be OK because GCC knows to look inside the conversion except if
8526 -- the type is discriminated. We assume that we are OK anyway if the
8527 -- type is not set yet or if it is controlled since we can't afford to
8528 -- introduce a temporary in this case.
8529
8530 elsif Nkind (Pexp) = N_Selected_Component
8531 and then Prefix (Pexp) = Exp
8532 then
8533 if No (Etype (Pexp)) then
8534 return True;
8535 else
8536 return
8537 not Has_Discriminants (Etype (Pexp))
8538 or else Is_Constrained (Etype (Pexp));
8539 end if;
8540 end if;
8541
8542 -- Set the output type, this comes from Etype if it is set, otherwise we
8543 -- take it from the subtype mark, which we assume was already fully
8544 -- analyzed.
8545
8546 if Present (Etype (Exp)) then
8547 Otyp := Etype (Exp);
8548 else
8549 Otyp := Entity (Subtype_Mark (Exp));
8550 end if;
8551
8552 -- The input type always comes from the expression, and we assume this
8553 -- is indeed always analyzed, so we can simply get the Etype.
8554
8555 Ityp := Etype (Expression (Exp));
8556
8557 -- Initialize alignments to unknown so far
8558
8559 Oalign := No_Uint;
8560 Ialign := No_Uint;
8561
8562 -- Replace a concurrent type by its corresponding record type and each
8563 -- type by its underlying type and do the tests on those. The original
8564 -- type may be a private type whose completion is a concurrent type, so
8565 -- find the underlying type first.
8566
8567 if Present (Underlying_Type (Otyp)) then
8568 Otyp := Underlying_Type (Otyp);
8569 end if;
8570
8571 if Present (Underlying_Type (Ityp)) then
8572 Ityp := Underlying_Type (Ityp);
8573 end if;
8574
8575 if Is_Concurrent_Type (Otyp) then
8576 Otyp := Corresponding_Record_Type (Otyp);
8577 end if;
8578
8579 if Is_Concurrent_Type (Ityp) then
8580 Ityp := Corresponding_Record_Type (Ityp);
8581 end if;
8582
8583 -- If the base types are the same, we know there is no problem since
8584 -- this conversion will be a noop.
8585
8586 if Implementation_Base_Type (Otyp) = Implementation_Base_Type (Ityp) then
8587 return True;
8588
8589 -- Same if this is an upwards conversion of an untagged type, and there
8590 -- are no constraints involved (could be more general???)
8591
8592 elsif Etype (Ityp) = Otyp
8593 and then not Is_Tagged_Type (Ityp)
8594 and then not Has_Discriminants (Ityp)
8595 and then No (First_Rep_Item (Base_Type (Ityp)))
8596 then
8597 return True;
8598
8599 -- If the expression has an access type (object or subprogram) we assume
8600 -- that the conversion is safe, because the size of the target is safe,
8601 -- even if it is a record (which might be treated as having unknown size
8602 -- at this point).
8603
8604 elsif Is_Access_Type (Ityp) then
8605 return True;
8606
8607 -- If the size of output type is known at compile time, there is never
8608 -- a problem. Note that unconstrained records are considered to be of
8609 -- known size, but we can't consider them that way here, because we are
8610 -- talking about the actual size of the object.
8611
8612 -- We also make sure that in addition to the size being known, we do not
8613 -- have a case which might generate an embarrassingly large temp in
8614 -- stack checking mode.
8615
8616 elsif Size_Known_At_Compile_Time (Otyp)
8617 and then
8618 (not Stack_Checking_Enabled
8619 or else not May_Generate_Large_Temp (Otyp))
8620 and then not (Is_Record_Type (Otyp) and then not Is_Constrained (Otyp))
8621 then
8622 return True;
8623
8624 -- If either type is tagged, then we know the alignment is OK so Gigi
8625 -- will be able to use pointer punning.
8626
8627 elsif Is_Tagged_Type (Otyp) or else Is_Tagged_Type (Ityp) then
8628 return True;
8629
8630 -- If either type is a limited record type, we cannot do a copy, so say
8631 -- safe since there's nothing else we can do.
8632
8633 elsif Is_Limited_Record (Otyp) or else Is_Limited_Record (Ityp) then
8634 return True;
8635
8636 -- Conversions to and from packed array types are always ignored and
8637 -- hence are safe.
8638
8639 elsif Is_Packed_Array_Impl_Type (Otyp)
8640 or else Is_Packed_Array_Impl_Type (Ityp)
8641 then
8642 return True;
8643 end if;
8644
8645 -- The only other cases known to be safe is if the input type's
8646 -- alignment is known to be at least the maximum alignment for the
8647 -- target or if both alignments are known and the output type's
8648 -- alignment is no stricter than the input's. We can use the component
8649 -- type alignement for an array if a type is an unpacked array type.
8650
8651 if Present (Alignment_Clause (Otyp)) then
8652 Oalign := Expr_Value (Expression (Alignment_Clause (Otyp)));
8653
8654 elsif Is_Array_Type (Otyp)
8655 and then Present (Alignment_Clause (Component_Type (Otyp)))
8656 then
8657 Oalign := Expr_Value (Expression (Alignment_Clause
8658 (Component_Type (Otyp))));
8659 end if;
8660
8661 if Present (Alignment_Clause (Ityp)) then
8662 Ialign := Expr_Value (Expression (Alignment_Clause (Ityp)));
8663
8664 elsif Is_Array_Type (Ityp)
8665 and then Present (Alignment_Clause (Component_Type (Ityp)))
8666 then
8667 Ialign := Expr_Value (Expression (Alignment_Clause
8668 (Component_Type (Ityp))));
8669 end if;
8670
8671 if Ialign /= No_Uint and then Ialign > Maximum_Alignment then
8672 return True;
8673
8674 elsif Ialign /= No_Uint
8675 and then Oalign /= No_Uint
8676 and then Ialign <= Oalign
8677 then
8678 return True;
8679
8680 -- Otherwise, Gigi cannot handle this and we must make a temporary
8681
8682 else
8683 return False;
8684 end if;
8685 end Safe_Unchecked_Type_Conversion;
8686
8687 ---------------------------------
8688 -- Set_Current_Value_Condition --
8689 ---------------------------------
8690
8691 -- Note: the implementation of this procedure is very closely tied to the
8692 -- implementation of Get_Current_Value_Condition. Here we set required
8693 -- Current_Value fields, and in Get_Current_Value_Condition, we interpret
8694 -- them, so they must have a consistent view.
8695
8696 procedure Set_Current_Value_Condition (Cnode : Node_Id) is
8697
8698 procedure Set_Entity_Current_Value (N : Node_Id);
8699 -- If N is an entity reference, where the entity is of an appropriate
8700 -- kind, then set the current value of this entity to Cnode, unless
8701 -- there is already a definite value set there.
8702
8703 procedure Set_Expression_Current_Value (N : Node_Id);
8704 -- If N is of an appropriate form, sets an appropriate entry in current
8705 -- value fields of relevant entities. Multiple entities can be affected
8706 -- in the case of an AND or AND THEN.
8707
8708 ------------------------------
8709 -- Set_Entity_Current_Value --
8710 ------------------------------
8711
8712 procedure Set_Entity_Current_Value (N : Node_Id) is
8713 begin
8714 if Is_Entity_Name (N) then
8715 declare
8716 Ent : constant Entity_Id := Entity (N);
8717
8718 begin
8719 -- Don't capture if not safe to do so
8720
8721 if not Safe_To_Capture_Value (N, Ent, Cond => True) then
8722 return;
8723 end if;
8724
8725 -- Here we have a case where the Current_Value field may need
8726 -- to be set. We set it if it is not already set to a compile
8727 -- time expression value.
8728
8729 -- Note that this represents a decision that one condition
8730 -- blots out another previous one. That's certainly right if
8731 -- they occur at the same level. If the second one is nested,
8732 -- then the decision is neither right nor wrong (it would be
8733 -- equally OK to leave the outer one in place, or take the new
8734 -- inner one. Really we should record both, but our data
8735 -- structures are not that elaborate.
8736
8737 if Nkind (Current_Value (Ent)) not in N_Subexpr then
8738 Set_Current_Value (Ent, Cnode);
8739 end if;
8740 end;
8741 end if;
8742 end Set_Entity_Current_Value;
8743
8744 ----------------------------------
8745 -- Set_Expression_Current_Value --
8746 ----------------------------------
8747
8748 procedure Set_Expression_Current_Value (N : Node_Id) is
8749 Cond : Node_Id;
8750
8751 begin
8752 Cond := N;
8753
8754 -- Loop to deal with (ignore for now) any NOT operators present. The
8755 -- presence of NOT operators will be handled properly when we call
8756 -- Get_Current_Value_Condition.
8757
8758 while Nkind (Cond) = N_Op_Not loop
8759 Cond := Right_Opnd (Cond);
8760 end loop;
8761
8762 -- For an AND or AND THEN, recursively process operands
8763
8764 if Nkind (Cond) = N_Op_And or else Nkind (Cond) = N_And_Then then
8765 Set_Expression_Current_Value (Left_Opnd (Cond));
8766 Set_Expression_Current_Value (Right_Opnd (Cond));
8767 return;
8768 end if;
8769
8770 -- Check possible relational operator
8771
8772 if Nkind (Cond) in N_Op_Compare then
8773 if Compile_Time_Known_Value (Right_Opnd (Cond)) then
8774 Set_Entity_Current_Value (Left_Opnd (Cond));
8775 elsif Compile_Time_Known_Value (Left_Opnd (Cond)) then
8776 Set_Entity_Current_Value (Right_Opnd (Cond));
8777 end if;
8778
8779 elsif Nkind_In (Cond,
8780 N_Type_Conversion,
8781 N_Qualified_Expression,
8782 N_Expression_With_Actions)
8783 then
8784 Set_Expression_Current_Value (Expression (Cond));
8785
8786 -- Check possible boolean variable reference
8787
8788 else
8789 Set_Entity_Current_Value (Cond);
8790 end if;
8791 end Set_Expression_Current_Value;
8792
8793 -- Start of processing for Set_Current_Value_Condition
8794
8795 begin
8796 Set_Expression_Current_Value (Condition (Cnode));
8797 end Set_Current_Value_Condition;
8798
8799 --------------------------
8800 -- Set_Elaboration_Flag --
8801 --------------------------
8802
8803 procedure Set_Elaboration_Flag (N : Node_Id; Spec_Id : Entity_Id) is
8804 Loc : constant Source_Ptr := Sloc (N);
8805 Ent : constant Entity_Id := Elaboration_Entity (Spec_Id);
8806 Asn : Node_Id;
8807
8808 begin
8809 if Present (Ent) then
8810
8811 -- Nothing to do if at the compilation unit level, because in this
8812 -- case the flag is set by the binder generated elaboration routine.
8813
8814 if Nkind (Parent (N)) = N_Compilation_Unit then
8815 null;
8816
8817 -- Here we do need to generate an assignment statement
8818
8819 else
8820 Check_Restriction (No_Elaboration_Code, N);
8821 Asn :=
8822 Make_Assignment_Statement (Loc,
8823 Name => New_Occurrence_Of (Ent, Loc),
8824 Expression => Make_Integer_Literal (Loc, Uint_1));
8825
8826 if Nkind (Parent (N)) = N_Subunit then
8827 Insert_After (Corresponding_Stub (Parent (N)), Asn);
8828 else
8829 Insert_After (N, Asn);
8830 end if;
8831
8832 Analyze (Asn);
8833
8834 -- Kill current value indication. This is necessary because the
8835 -- tests of this flag are inserted out of sequence and must not
8836 -- pick up bogus indications of the wrong constant value.
8837
8838 Set_Current_Value (Ent, Empty);
8839
8840 -- If the subprogram is in the current declarative part and
8841 -- 'access has been applied to it, generate an elaboration
8842 -- check at the beginning of the declarations of the body.
8843
8844 if Nkind (N) = N_Subprogram_Body
8845 and then Address_Taken (Spec_Id)
8846 and then
8847 Ekind_In (Scope (Spec_Id), E_Block, E_Procedure, E_Function)
8848 then
8849 declare
8850 Loc : constant Source_Ptr := Sloc (N);
8851 Decls : constant List_Id := Declarations (N);
8852 Chk : Node_Id;
8853
8854 begin
8855 -- No need to generate this check if first entry in the
8856 -- declaration list is a raise of Program_Error now.
8857
8858 if Present (Decls)
8859 and then Nkind (First (Decls)) = N_Raise_Program_Error
8860 then
8861 return;
8862 end if;
8863
8864 -- Otherwise generate the check
8865
8866 Chk :=
8867 Make_Raise_Program_Error (Loc,
8868 Condition =>
8869 Make_Op_Eq (Loc,
8870 Left_Opnd => New_Occurrence_Of (Ent, Loc),
8871 Right_Opnd => Make_Integer_Literal (Loc, Uint_0)),
8872 Reason => PE_Access_Before_Elaboration);
8873
8874 if No (Decls) then
8875 Set_Declarations (N, New_List (Chk));
8876 else
8877 Prepend (Chk, Decls);
8878 end if;
8879
8880 Analyze (Chk);
8881 end;
8882 end if;
8883 end if;
8884 end if;
8885 end Set_Elaboration_Flag;
8886
8887 ----------------------------
8888 -- Set_Renamed_Subprogram --
8889 ----------------------------
8890
8891 procedure Set_Renamed_Subprogram (N : Node_Id; E : Entity_Id) is
8892 begin
8893 -- If input node is an identifier, we can just reset it
8894
8895 if Nkind (N) = N_Identifier then
8896 Set_Chars (N, Chars (E));
8897 Set_Entity (N, E);
8898
8899 -- Otherwise we have to do a rewrite, preserving Comes_From_Source
8900
8901 else
8902 declare
8903 CS : constant Boolean := Comes_From_Source (N);
8904 begin
8905 Rewrite (N, Make_Identifier (Sloc (N), Chars (E)));
8906 Set_Entity (N, E);
8907 Set_Comes_From_Source (N, CS);
8908 Set_Analyzed (N, True);
8909 end;
8910 end if;
8911 end Set_Renamed_Subprogram;
8912
8913 ----------------------
8914 -- Side_Effect_Free --
8915 ----------------------
8916
8917 function Side_Effect_Free
8918 (N : Node_Id;
8919 Name_Req : Boolean := False;
8920 Variable_Ref : Boolean := False) return Boolean
8921 is
8922 Typ : constant Entity_Id := Etype (N);
8923 -- Result type of the expression
8924
8925 function Safe_Prefixed_Reference (N : Node_Id) return Boolean;
8926 -- The argument N is a construct where the Prefix is dereferenced if it
8927 -- is an access type and the result is a variable. The call returns True
8928 -- if the construct is side effect free (not considering side effects in
8929 -- other than the prefix which are to be tested by the caller).
8930
8931 function Within_In_Parameter (N : Node_Id) return Boolean;
8932 -- Determines if N is a subcomponent of a composite in-parameter. If so,
8933 -- N is not side-effect free when the actual is global and modifiable
8934 -- indirectly from within a subprogram, because it may be passed by
8935 -- reference. The front-end must be conservative here and assume that
8936 -- this may happen with any array or record type. On the other hand, we
8937 -- cannot create temporaries for all expressions for which this
8938 -- condition is true, for various reasons that might require clearing up
8939 -- ??? For example, discriminant references that appear out of place, or
8940 -- spurious type errors with class-wide expressions. As a result, we
8941 -- limit the transformation to loop bounds, which is so far the only
8942 -- case that requires it.
8943
8944 -----------------------------
8945 -- Safe_Prefixed_Reference --
8946 -----------------------------
8947
8948 function Safe_Prefixed_Reference (N : Node_Id) return Boolean is
8949 begin
8950 -- If prefix is not side effect free, definitely not safe
8951
8952 if not Side_Effect_Free (Prefix (N), Name_Req, Variable_Ref) then
8953 return False;
8954
8955 -- If the prefix is of an access type that is not access-to-constant,
8956 -- then this construct is a variable reference, which means it is to
8957 -- be considered to have side effects if Variable_Ref is set True.
8958
8959 elsif Is_Access_Type (Etype (Prefix (N)))
8960 and then not Is_Access_Constant (Etype (Prefix (N)))
8961 and then Variable_Ref
8962 then
8963 -- Exception is a prefix that is the result of a previous removal
8964 -- of side-effects.
8965
8966 return Is_Entity_Name (Prefix (N))
8967 and then not Comes_From_Source (Prefix (N))
8968 and then Ekind (Entity (Prefix (N))) = E_Constant
8969 and then Is_Internal_Name (Chars (Entity (Prefix (N))));
8970
8971 -- If the prefix is an explicit dereference then this construct is a
8972 -- variable reference, which means it is to be considered to have
8973 -- side effects if Variable_Ref is True.
8974
8975 -- We do NOT exclude dereferences of access-to-constant types because
8976 -- we handle them as constant view of variables.
8977
8978 elsif Nkind (Prefix (N)) = N_Explicit_Dereference
8979 and then Variable_Ref
8980 then
8981 return False;
8982
8983 -- Note: The following test is the simplest way of solving a complex
8984 -- problem uncovered by the following test (Side effect on loop bound
8985 -- that is a subcomponent of a global variable:
8986
8987 -- with Text_Io; use Text_Io;
8988 -- procedure Tloop is
8989 -- type X is
8990 -- record
8991 -- V : Natural := 4;
8992 -- S : String (1..5) := (others => 'a');
8993 -- end record;
8994 -- X1 : X;
8995
8996 -- procedure Modi;
8997
8998 -- generic
8999 -- with procedure Action;
9000 -- procedure Loop_G (Arg : X; Msg : String)
9001
9002 -- procedure Loop_G (Arg : X; Msg : String) is
9003 -- begin
9004 -- Put_Line ("begin loop_g " & Msg & " will loop till: "
9005 -- & Natural'Image (Arg.V));
9006 -- for Index in 1 .. Arg.V loop
9007 -- Text_Io.Put_Line
9008 -- (Natural'Image (Index) & " " & Arg.S (Index));
9009 -- if Index > 2 then
9010 -- Modi;
9011 -- end if;
9012 -- end loop;
9013 -- Put_Line ("end loop_g " & Msg);
9014 -- end;
9015
9016 -- procedure Loop1 is new Loop_G (Modi);
9017 -- procedure Modi is
9018 -- begin
9019 -- X1.V := 1;
9020 -- Loop1 (X1, "from modi");
9021 -- end;
9022 --
9023 -- begin
9024 -- Loop1 (X1, "initial");
9025 -- end;
9026
9027 -- The output of the above program should be:
9028
9029 -- begin loop_g initial will loop till: 4
9030 -- 1 a
9031 -- 2 a
9032 -- 3 a
9033 -- begin loop_g from modi will loop till: 1
9034 -- 1 a
9035 -- end loop_g from modi
9036 -- 4 a
9037 -- begin loop_g from modi will loop till: 1
9038 -- 1 a
9039 -- end loop_g from modi
9040 -- end loop_g initial
9041
9042 -- If a loop bound is a subcomponent of a global variable, a
9043 -- modification of that variable within the loop may incorrectly
9044 -- affect the execution of the loop.
9045
9046 elsif Nkind (Parent (Parent (N))) = N_Loop_Parameter_Specification
9047 and then Within_In_Parameter (Prefix (N))
9048 and then Variable_Ref
9049 then
9050 return False;
9051
9052 -- All other cases are side effect free
9053
9054 else
9055 return True;
9056 end if;
9057 end Safe_Prefixed_Reference;
9058
9059 -------------------------
9060 -- Within_In_Parameter --
9061 -------------------------
9062
9063 function Within_In_Parameter (N : Node_Id) return Boolean is
9064 begin
9065 if not Comes_From_Source (N) then
9066 return False;
9067
9068 elsif Is_Entity_Name (N) then
9069 return Ekind (Entity (N)) = E_In_Parameter;
9070
9071 elsif Nkind_In (N, N_Indexed_Component, N_Selected_Component) then
9072 return Within_In_Parameter (Prefix (N));
9073
9074 else
9075 return False;
9076 end if;
9077 end Within_In_Parameter;
9078
9079 -- Start of processing for Side_Effect_Free
9080
9081 begin
9082 -- If volatile reference, always consider it to have side effects
9083
9084 if Is_Volatile_Reference (N) then
9085 return False;
9086 end if;
9087
9088 -- Note on checks that could raise Constraint_Error. Strictly, if we
9089 -- take advantage of 11.6, these checks do not count as side effects.
9090 -- However, we would prefer to consider that they are side effects,
9091 -- since the backend CSE does not work very well on expressions which
9092 -- can raise Constraint_Error. On the other hand if we don't consider
9093 -- them to be side effect free, then we get some awkward expansions
9094 -- in -gnato mode, resulting in code insertions at a point where we
9095 -- do not have a clear model for performing the insertions.
9096
9097 -- Special handling for entity names
9098
9099 if Is_Entity_Name (N) then
9100
9101 -- A type reference is always side effect free
9102
9103 if Is_Type (Entity (N)) then
9104 return True;
9105
9106 -- Variables are considered to be a side effect if Variable_Ref
9107 -- is set or if we have a volatile reference and Name_Req is off.
9108 -- If Name_Req is True then we can't help returning a name which
9109 -- effectively allows multiple references in any case.
9110
9111 elsif Is_Variable (N, Use_Original_Node => False) then
9112 return not Variable_Ref
9113 and then (not Is_Volatile_Reference (N) or else Name_Req);
9114
9115 -- Any other entity (e.g. a subtype name) is definitely side
9116 -- effect free.
9117
9118 else
9119 return True;
9120 end if;
9121
9122 -- A value known at compile time is always side effect free
9123
9124 elsif Compile_Time_Known_Value (N) then
9125 return True;
9126
9127 -- A variable renaming is not side-effect free, because the renaming
9128 -- will function like a macro in the front-end in some cases, and an
9129 -- assignment can modify the component designated by N, so we need to
9130 -- create a temporary for it.
9131
9132 -- The guard testing for Entity being present is needed at least in
9133 -- the case of rewritten predicate expressions, and may well also be
9134 -- appropriate elsewhere. Obviously we can't go testing the entity
9135 -- field if it does not exist, so it's reasonable to say that this is
9136 -- not the renaming case if it does not exist.
9137
9138 elsif Is_Entity_Name (Original_Node (N))
9139 and then Present (Entity (Original_Node (N)))
9140 and then Is_Renaming_Of_Object (Entity (Original_Node (N)))
9141 and then Ekind (Entity (Original_Node (N))) /= E_Constant
9142 then
9143 declare
9144 RO : constant Node_Id :=
9145 Renamed_Object (Entity (Original_Node (N)));
9146
9147 begin
9148 -- If the renamed object is an indexed component, or an
9149 -- explicit dereference, then the designated object could
9150 -- be modified by an assignment.
9151
9152 if Nkind_In (RO, N_Indexed_Component,
9153 N_Explicit_Dereference)
9154 then
9155 return False;
9156
9157 -- A selected component must have a safe prefix
9158
9159 elsif Nkind (RO) = N_Selected_Component then
9160 return Safe_Prefixed_Reference (RO);
9161
9162 -- In all other cases, designated object cannot be changed so
9163 -- we are side effect free.
9164
9165 else
9166 return True;
9167 end if;
9168 end;
9169
9170 -- Remove_Side_Effects generates an object renaming declaration to
9171 -- capture the expression of a class-wide expression. In VM targets
9172 -- the frontend performs no expansion for dispatching calls to
9173 -- class- wide types since they are handled by the VM. Hence, we must
9174 -- locate here if this node corresponds to a previous invocation of
9175 -- Remove_Side_Effects to avoid a never ending loop in the frontend.
9176
9177 elsif not Tagged_Type_Expansion
9178 and then not Comes_From_Source (N)
9179 and then Nkind (Parent (N)) = N_Object_Renaming_Declaration
9180 and then Is_Class_Wide_Type (Typ)
9181 then
9182 return True;
9183
9184 -- Generating C the type conversion of an access to constrained array
9185 -- type into an access to unconstrained array type involves initializing
9186 -- a fat pointer and the expression cannot be assumed to be free of side
9187 -- effects since it must referenced several times to compute its bounds.
9188
9189 elsif Generate_C_Code
9190 and then Nkind (N) = N_Type_Conversion
9191 and then Is_Access_Type (Typ)
9192 and then Is_Array_Type (Designated_Type (Typ))
9193 and then not Is_Constrained (Designated_Type (Typ))
9194 then
9195 return False;
9196 end if;
9197
9198 -- For other than entity names and compile time known values,
9199 -- check the node kind for special processing.
9200
9201 case Nkind (N) is
9202
9203 -- An attribute reference is side effect free if its expressions
9204 -- are side effect free and its prefix is side effect free or
9205 -- is an entity reference.
9206
9207 -- Is this right? what about x'first where x is a variable???
9208
9209 when N_Attribute_Reference =>
9210 return Side_Effect_Free (Expressions (N), Name_Req, Variable_Ref)
9211 and then Attribute_Name (N) /= Name_Input
9212 and then (Is_Entity_Name (Prefix (N))
9213 or else Side_Effect_Free
9214 (Prefix (N), Name_Req, Variable_Ref));
9215
9216 -- A binary operator is side effect free if and both operands are
9217 -- side effect free. For this purpose binary operators include
9218 -- membership tests and short circuit forms.
9219
9220 when N_Binary_Op | N_Membership_Test | N_Short_Circuit =>
9221 return Side_Effect_Free (Left_Opnd (N), Name_Req, Variable_Ref)
9222 and then
9223 Side_Effect_Free (Right_Opnd (N), Name_Req, Variable_Ref);
9224
9225 -- An explicit dereference is side effect free only if it is
9226 -- a side effect free prefixed reference.
9227
9228 when N_Explicit_Dereference =>
9229 return Safe_Prefixed_Reference (N);
9230
9231 -- An expression with action is side effect free if its expression
9232 -- is side effect free and it has no actions.
9233
9234 when N_Expression_With_Actions =>
9235 return Is_Empty_List (Actions (N))
9236 and then
9237 Side_Effect_Free (Expression (N), Name_Req, Variable_Ref);
9238
9239 -- A call to _rep_to_pos is side effect free, since we generate
9240 -- this pure function call ourselves. Moreover it is critically
9241 -- important to make this exception, since otherwise we can have
9242 -- discriminants in array components which don't look side effect
9243 -- free in the case of an array whose index type is an enumeration
9244 -- type with an enumeration rep clause.
9245
9246 -- All other function calls are not side effect free
9247
9248 when N_Function_Call =>
9249 return Nkind (Name (N)) = N_Identifier
9250 and then Is_TSS (Name (N), TSS_Rep_To_Pos)
9251 and then
9252 Side_Effect_Free
9253 (First (Parameter_Associations (N)), Name_Req, Variable_Ref);
9254
9255 -- An IF expression is side effect free if it's of a scalar type, and
9256 -- all its components are all side effect free (conditions and then
9257 -- actions and else actions). We restrict to scalar types, since it
9258 -- is annoying to deal with things like (if A then B else C)'First
9259 -- where the type involved is a string type.
9260
9261 when N_If_Expression =>
9262 return Is_Scalar_Type (Typ)
9263 and then
9264 Side_Effect_Free (Expressions (N), Name_Req, Variable_Ref);
9265
9266 -- An indexed component is side effect free if it is a side
9267 -- effect free prefixed reference and all the indexing
9268 -- expressions are side effect free.
9269
9270 when N_Indexed_Component =>
9271 return Side_Effect_Free (Expressions (N), Name_Req, Variable_Ref)
9272 and then Safe_Prefixed_Reference (N);
9273
9274 -- A type qualification is side effect free if the expression
9275 -- is side effect free.
9276
9277 when N_Qualified_Expression =>
9278 return Side_Effect_Free (Expression (N), Name_Req, Variable_Ref);
9279
9280 -- A selected component is side effect free only if it is a side
9281 -- effect free prefixed reference.
9282
9283 when N_Selected_Component =>
9284 return Safe_Prefixed_Reference (N);
9285
9286 -- A range is side effect free if the bounds are side effect free
9287
9288 when N_Range =>
9289 return Side_Effect_Free (Low_Bound (N), Name_Req, Variable_Ref)
9290 and then
9291 Side_Effect_Free (High_Bound (N), Name_Req, Variable_Ref);
9292
9293 -- A slice is side effect free if it is a side effect free
9294 -- prefixed reference and the bounds are side effect free.
9295
9296 when N_Slice =>
9297 return Side_Effect_Free
9298 (Discrete_Range (N), Name_Req, Variable_Ref)
9299 and then Safe_Prefixed_Reference (N);
9300
9301 -- A type conversion is side effect free if the expression to be
9302 -- converted is side effect free.
9303
9304 when N_Type_Conversion =>
9305 return Side_Effect_Free (Expression (N), Name_Req, Variable_Ref);
9306
9307 -- A unary operator is side effect free if the operand
9308 -- is side effect free.
9309
9310 when N_Unary_Op =>
9311 return Side_Effect_Free (Right_Opnd (N), Name_Req, Variable_Ref);
9312
9313 -- An unchecked type conversion is side effect free only if it
9314 -- is safe and its argument is side effect free.
9315
9316 when N_Unchecked_Type_Conversion =>
9317 return Safe_Unchecked_Type_Conversion (N)
9318 and then
9319 Side_Effect_Free (Expression (N), Name_Req, Variable_Ref);
9320
9321 -- An unchecked expression is side effect free if its expression
9322 -- is side effect free.
9323
9324 when N_Unchecked_Expression =>
9325 return Side_Effect_Free (Expression (N), Name_Req, Variable_Ref);
9326
9327 -- A literal is side effect free
9328
9329 when N_Character_Literal |
9330 N_Integer_Literal |
9331 N_Real_Literal |
9332 N_String_Literal =>
9333 return True;
9334
9335 -- We consider that anything else has side effects. This is a bit
9336 -- crude, but we are pretty close for most common cases, and we
9337 -- are certainly correct (i.e. we never return True when the
9338 -- answer should be False).
9339
9340 when others =>
9341 return False;
9342 end case;
9343 end Side_Effect_Free;
9344
9345 -- A list is side effect free if all elements of the list are side
9346 -- effect free.
9347
9348 function Side_Effect_Free
9349 (L : List_Id;
9350 Name_Req : Boolean := False;
9351 Variable_Ref : Boolean := False) return Boolean
9352 is
9353 N : Node_Id;
9354
9355 begin
9356 if L = No_List or else L = Error_List then
9357 return True;
9358
9359 else
9360 N := First (L);
9361 while Present (N) loop
9362 if not Side_Effect_Free (N, Name_Req, Variable_Ref) then
9363 return False;
9364 else
9365 Next (N);
9366 end if;
9367 end loop;
9368
9369 return True;
9370 end if;
9371 end Side_Effect_Free;
9372
9373 ----------------------------------
9374 -- Silly_Boolean_Array_Not_Test --
9375 ----------------------------------
9376
9377 -- This procedure implements an odd and silly test. We explicitly check
9378 -- for the case where the 'First of the component type is equal to the
9379 -- 'Last of this component type, and if this is the case, we make sure
9380 -- that constraint error is raised. The reason is that the NOT is bound
9381 -- to cause CE in this case, and we will not otherwise catch it.
9382
9383 -- No such check is required for AND and OR, since for both these cases
9384 -- False op False = False, and True op True = True. For the XOR case,
9385 -- see Silly_Boolean_Array_Xor_Test.
9386
9387 -- Believe it or not, this was reported as a bug. Note that nearly always,
9388 -- the test will evaluate statically to False, so the code will be
9389 -- statically removed, and no extra overhead caused.
9390
9391 procedure Silly_Boolean_Array_Not_Test (N : Node_Id; T : Entity_Id) is
9392 Loc : constant Source_Ptr := Sloc (N);
9393 CT : constant Entity_Id := Component_Type (T);
9394
9395 begin
9396 -- The check we install is
9397
9398 -- constraint_error when
9399 -- component_type'first = component_type'last
9400 -- and then array_type'Length /= 0)
9401
9402 -- We need the last guard because we don't want to raise CE for empty
9403 -- arrays since no out of range values result. (Empty arrays with a
9404 -- component type of True .. True -- very useful -- even the ACATS
9405 -- does not test that marginal case).
9406
9407 Insert_Action (N,
9408 Make_Raise_Constraint_Error (Loc,
9409 Condition =>
9410 Make_And_Then (Loc,
9411 Left_Opnd =>
9412 Make_Op_Eq (Loc,
9413 Left_Opnd =>
9414 Make_Attribute_Reference (Loc,
9415 Prefix => New_Occurrence_Of (CT, Loc),
9416 Attribute_Name => Name_First),
9417
9418 Right_Opnd =>
9419 Make_Attribute_Reference (Loc,
9420 Prefix => New_Occurrence_Of (CT, Loc),
9421 Attribute_Name => Name_Last)),
9422
9423 Right_Opnd => Make_Non_Empty_Check (Loc, Right_Opnd (N))),
9424 Reason => CE_Range_Check_Failed));
9425 end Silly_Boolean_Array_Not_Test;
9426
9427 ----------------------------------
9428 -- Silly_Boolean_Array_Xor_Test --
9429 ----------------------------------
9430
9431 -- This procedure implements an odd and silly test. We explicitly check
9432 -- for the XOR case where the component type is True .. True, since this
9433 -- will raise constraint error. A special check is required since CE
9434 -- will not be generated otherwise (cf Expand_Packed_Not).
9435
9436 -- No such check is required for AND and OR, since for both these cases
9437 -- False op False = False, and True op True = True, and no check is
9438 -- required for the case of False .. False, since False xor False = False.
9439 -- See also Silly_Boolean_Array_Not_Test
9440
9441 procedure Silly_Boolean_Array_Xor_Test (N : Node_Id; T : Entity_Id) is
9442 Loc : constant Source_Ptr := Sloc (N);
9443 CT : constant Entity_Id := Component_Type (T);
9444
9445 begin
9446 -- The check we install is
9447
9448 -- constraint_error when
9449 -- Boolean (component_type'First)
9450 -- and then Boolean (component_type'Last)
9451 -- and then array_type'Length /= 0)
9452
9453 -- We need the last guard because we don't want to raise CE for empty
9454 -- arrays since no out of range values result (Empty arrays with a
9455 -- component type of True .. True -- very useful -- even the ACATS
9456 -- does not test that marginal case).
9457
9458 Insert_Action (N,
9459 Make_Raise_Constraint_Error (Loc,
9460 Condition =>
9461 Make_And_Then (Loc,
9462 Left_Opnd =>
9463 Make_And_Then (Loc,
9464 Left_Opnd =>
9465 Convert_To (Standard_Boolean,
9466 Make_Attribute_Reference (Loc,
9467 Prefix => New_Occurrence_Of (CT, Loc),
9468 Attribute_Name => Name_First)),
9469
9470 Right_Opnd =>
9471 Convert_To (Standard_Boolean,
9472 Make_Attribute_Reference (Loc,
9473 Prefix => New_Occurrence_Of (CT, Loc),
9474 Attribute_Name => Name_Last))),
9475
9476 Right_Opnd => Make_Non_Empty_Check (Loc, Right_Opnd (N))),
9477 Reason => CE_Range_Check_Failed));
9478 end Silly_Boolean_Array_Xor_Test;
9479
9480 --------------------------
9481 -- Target_Has_Fixed_Ops --
9482 --------------------------
9483
9484 Integer_Sized_Small : Ureal;
9485 -- Set to 2.0 ** -(Integer'Size - 1) the first time that this function is
9486 -- called (we don't want to compute it more than once).
9487
9488 Long_Integer_Sized_Small : Ureal;
9489 -- Set to 2.0 ** -(Long_Integer'Size - 1) the first time that this function
9490 -- is called (we don't want to compute it more than once)
9491
9492 First_Time_For_THFO : Boolean := True;
9493 -- Set to False after first call (if Fractional_Fixed_Ops_On_Target)
9494
9495 function Target_Has_Fixed_Ops
9496 (Left_Typ : Entity_Id;
9497 Right_Typ : Entity_Id;
9498 Result_Typ : Entity_Id) return Boolean
9499 is
9500 function Is_Fractional_Type (Typ : Entity_Id) return Boolean;
9501 -- Return True if the given type is a fixed-point type with a small
9502 -- value equal to 2 ** (-(T'Object_Size - 1)) and whose values have
9503 -- an absolute value less than 1.0. This is currently limited to
9504 -- fixed-point types that map to Integer or Long_Integer.
9505
9506 ------------------------
9507 -- Is_Fractional_Type --
9508 ------------------------
9509
9510 function Is_Fractional_Type (Typ : Entity_Id) return Boolean is
9511 begin
9512 if Esize (Typ) = Standard_Integer_Size then
9513 return Small_Value (Typ) = Integer_Sized_Small;
9514
9515 elsif Esize (Typ) = Standard_Long_Integer_Size then
9516 return Small_Value (Typ) = Long_Integer_Sized_Small;
9517
9518 else
9519 return False;
9520 end if;
9521 end Is_Fractional_Type;
9522
9523 -- Start of processing for Target_Has_Fixed_Ops
9524
9525 begin
9526 -- Return False if Fractional_Fixed_Ops_On_Target is false
9527
9528 if not Fractional_Fixed_Ops_On_Target then
9529 return False;
9530 end if;
9531
9532 -- Here the target has Fractional_Fixed_Ops, if first time, compute
9533 -- standard constants used by Is_Fractional_Type.
9534
9535 if First_Time_For_THFO then
9536 First_Time_For_THFO := False;
9537
9538 Integer_Sized_Small :=
9539 UR_From_Components
9540 (Num => Uint_1,
9541 Den => UI_From_Int (Standard_Integer_Size - 1),
9542 Rbase => 2);
9543
9544 Long_Integer_Sized_Small :=
9545 UR_From_Components
9546 (Num => Uint_1,
9547 Den => UI_From_Int (Standard_Long_Integer_Size - 1),
9548 Rbase => 2);
9549 end if;
9550
9551 -- Return True if target supports fixed-by-fixed multiply/divide for
9552 -- fractional fixed-point types (see Is_Fractional_Type) and the operand
9553 -- and result types are equivalent fractional types.
9554
9555 return Is_Fractional_Type (Base_Type (Left_Typ))
9556 and then Is_Fractional_Type (Base_Type (Right_Typ))
9557 and then Is_Fractional_Type (Base_Type (Result_Typ))
9558 and then Esize (Left_Typ) = Esize (Right_Typ)
9559 and then Esize (Left_Typ) = Esize (Result_Typ);
9560 end Target_Has_Fixed_Ops;
9561
9562 ------------------------------------------
9563 -- Type_May_Have_Bit_Aligned_Components --
9564 ------------------------------------------
9565
9566 function Type_May_Have_Bit_Aligned_Components
9567 (Typ : Entity_Id) return Boolean
9568 is
9569 begin
9570 -- Array type, check component type
9571
9572 if Is_Array_Type (Typ) then
9573 return
9574 Type_May_Have_Bit_Aligned_Components (Component_Type (Typ));
9575
9576 -- Record type, check components
9577
9578 elsif Is_Record_Type (Typ) then
9579 declare
9580 E : Entity_Id;
9581
9582 begin
9583 E := First_Component_Or_Discriminant (Typ);
9584 while Present (E) loop
9585 if Component_May_Be_Bit_Aligned (E)
9586 or else Type_May_Have_Bit_Aligned_Components (Etype (E))
9587 then
9588 return True;
9589 end if;
9590
9591 Next_Component_Or_Discriminant (E);
9592 end loop;
9593
9594 return False;
9595 end;
9596
9597 -- Type other than array or record is always OK
9598
9599 else
9600 return False;
9601 end if;
9602 end Type_May_Have_Bit_Aligned_Components;
9603
9604 ----------------------------------
9605 -- Within_Case_Or_If_Expression --
9606 ----------------------------------
9607
9608 function Within_Case_Or_If_Expression (N : Node_Id) return Boolean is
9609 Par : Node_Id;
9610
9611 begin
9612 -- Locate an enclosing case or if expression. Note that these constructs
9613 -- can be expanded into Expression_With_Actions, hence the test of the
9614 -- original node.
9615
9616 Par := Parent (N);
9617 while Present (Par) loop
9618 if Nkind_In (Original_Node (Par), N_Case_Expression,
9619 N_If_Expression)
9620 then
9621 return True;
9622
9623 -- Prevent the search from going too far
9624
9625 elsif Is_Body_Or_Package_Declaration (Par) then
9626 return False;
9627 end if;
9628
9629 Par := Parent (Par);
9630 end loop;
9631
9632 return False;
9633 end Within_Case_Or_If_Expression;
9634
9635 --------------------------------
9636 -- Within_Internal_Subprogram --
9637 --------------------------------
9638
9639 function Within_Internal_Subprogram return Boolean is
9640 S : Entity_Id;
9641
9642 begin
9643 S := Current_Scope;
9644 while Present (S) and then not Is_Subprogram (S) loop
9645 S := Scope (S);
9646 end loop;
9647
9648 return Present (S)
9649 and then Get_TSS_Name (S) /= TSS_Null
9650 and then not Is_Predicate_Function (S)
9651 and then not Is_Predicate_Function_M (S);
9652 end Within_Internal_Subprogram;
9653
9654 end Exp_Util;