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PR ada/18819
[official-gcc.git] / gcc / ada / exp_util.adb
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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) 1992-2006, 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 2, 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 COPYING. If not, write --
19 -- to the Free Software Foundation, 51 Franklin Street, Fifth Floor, --
20 -- Boston, MA 02110-1301, USA. --
21 -- --
22 -- GNAT was originally developed by the GNAT team at New York University. --
23 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 -- --
25 ------------------------------------------------------------------------------
26
27 with Atree; use Atree;
28 with Checks; use Checks;
29 with Debug; use Debug;
30 with Einfo; use Einfo;
31 with Elists; use Elists;
32 with Errout; use Errout;
33 with Exp_Aggr; use Exp_Aggr;
34 with Exp_Ch7; use Exp_Ch7;
35 with Hostparm; use Hostparm;
36 with Inline; use Inline;
37 with Itypes; use Itypes;
38 with Lib; use Lib;
39 with Namet; use Namet;
40 with Nlists; use Nlists;
41 with Nmake; use Nmake;
42 with Opt; use Opt;
43 with Restrict; use Restrict;
44 with Rident; use Rident;
45 with Sem; use Sem;
46 with Sem_Ch8; use Sem_Ch8;
47 with Sem_Eval; use Sem_Eval;
48 with Sem_Res; use Sem_Res;
49 with Sem_Type; use Sem_Type;
50 with Sem_Util; use Sem_Util;
51 with Snames; use Snames;
52 with Stand; use Stand;
53 with Stringt; use Stringt;
54 with Targparm; use Targparm;
55 with Tbuild; use Tbuild;
56 with Ttypes; use Ttypes;
57 with Uintp; use Uintp;
58 with Urealp; use Urealp;
59 with Validsw; use Validsw;
60
61 package body Exp_Util is
62
63 -----------------------
64 -- Local Subprograms --
65 -----------------------
66
67 function Build_Task_Array_Image
68 (Loc : Source_Ptr;
69 Id_Ref : Node_Id;
70 A_Type : Entity_Id;
71 Dyn : Boolean := False) return Node_Id;
72 -- Build function to generate the image string for a task that is an
73 -- array component, concatenating the images of each index. To avoid
74 -- storage leaks, the string is built with successive slice assignments.
75 -- The flag Dyn indicates whether this is called for the initialization
76 -- procedure of an array of tasks, or for the name of a dynamically
77 -- created task that is assigned to an indexed component.
78
79 function Build_Task_Image_Function
80 (Loc : Source_Ptr;
81 Decls : List_Id;
82 Stats : List_Id;
83 Res : Entity_Id) return Node_Id;
84 -- Common processing for Task_Array_Image and Task_Record_Image.
85 -- Build function body that computes image.
86
87 procedure Build_Task_Image_Prefix
88 (Loc : Source_Ptr;
89 Len : out Entity_Id;
90 Res : out Entity_Id;
91 Pos : out Entity_Id;
92 Prefix : Entity_Id;
93 Sum : Node_Id;
94 Decls : in out List_Id;
95 Stats : in out List_Id);
96 -- Common processing for Task_Array_Image and Task_Record_Image.
97 -- Create local variables and assign prefix of name to result string.
98
99 function Build_Task_Record_Image
100 (Loc : Source_Ptr;
101 Id_Ref : Node_Id;
102 Dyn : Boolean := False) return Node_Id;
103 -- Build function to generate the image string for a task that is a
104 -- record component. Concatenate name of variable with that of selector.
105 -- The flag Dyn indicates whether this is called for the initialization
106 -- procedure of record with task components, or for a dynamically
107 -- created task that is assigned to a selected component.
108
109 function Make_CW_Equivalent_Type
110 (T : Entity_Id;
111 E : Node_Id) return Entity_Id;
112 -- T is a class-wide type entity, E is the initial expression node that
113 -- constrains T in case such as: " X: T := E" or "new T'(E)"
114 -- This function returns the entity of the Equivalent type and inserts
115 -- on the fly the necessary declaration such as:
116 --
117 -- type anon is record
118 -- _parent : Root_Type (T); constrained with E discriminants (if any)
119 -- Extension : String (1 .. expr to match size of E);
120 -- end record;
121 --
122 -- This record is compatible with any object of the class of T thanks
123 -- to the first field and has the same size as E thanks to the second.
124
125 function Make_Literal_Range
126 (Loc : Source_Ptr;
127 Literal_Typ : Entity_Id) return Node_Id;
128 -- Produce a Range node whose bounds are:
129 -- Low_Bound (Literal_Type) ..
130 -- Low_Bound (Literal_Type) + Length (Literal_Typ) - 1
131 -- this is used for expanding declarations like X : String := "sdfgdfg";
132
133 function New_Class_Wide_Subtype
134 (CW_Typ : Entity_Id;
135 N : Node_Id) return Entity_Id;
136 -- Create an implicit subtype of CW_Typ attached to node N
137
138 ----------------------
139 -- Adjust_Condition --
140 ----------------------
141
142 procedure Adjust_Condition (N : Node_Id) is
143 begin
144 if No (N) then
145 return;
146 end if;
147
148 declare
149 Loc : constant Source_Ptr := Sloc (N);
150 T : constant Entity_Id := Etype (N);
151 Ti : Entity_Id;
152
153 begin
154 -- For now, we simply ignore a call where the argument has no
155 -- type (probably case of unanalyzed condition), or has a type
156 -- that is not Boolean. This is because this is a pretty marginal
157 -- piece of functionality, and violations of these rules are
158 -- likely to be truly marginal (how much code uses Fortran Logical
159 -- as the barrier to a protected entry?) and we do not want to
160 -- blow up existing programs. We can change this to an assertion
161 -- after 3.12a is released ???
162
163 if No (T) or else not Is_Boolean_Type (T) then
164 return;
165 end if;
166
167 -- Apply validity checking if needed
168
169 if Validity_Checks_On and Validity_Check_Tests then
170 Ensure_Valid (N);
171 end if;
172
173 -- Immediate return if standard boolean, the most common case,
174 -- where nothing needs to be done.
175
176 if Base_Type (T) = Standard_Boolean then
177 return;
178 end if;
179
180 -- Case of zero/non-zero semantics or non-standard enumeration
181 -- representation. In each case, we rewrite the node as:
182
183 -- ityp!(N) /= False'Enum_Rep
184
185 -- where ityp is an integer type with large enough size to hold
186 -- any value of type T.
187
188 if Nonzero_Is_True (T) or else Has_Non_Standard_Rep (T) then
189 if Esize (T) <= Esize (Standard_Integer) then
190 Ti := Standard_Integer;
191 else
192 Ti := Standard_Long_Long_Integer;
193 end if;
194
195 Rewrite (N,
196 Make_Op_Ne (Loc,
197 Left_Opnd => Unchecked_Convert_To (Ti, N),
198 Right_Opnd =>
199 Make_Attribute_Reference (Loc,
200 Attribute_Name => Name_Enum_Rep,
201 Prefix =>
202 New_Occurrence_Of (First_Literal (T), Loc))));
203 Analyze_And_Resolve (N, Standard_Boolean);
204
205 else
206 Rewrite (N, Convert_To (Standard_Boolean, N));
207 Analyze_And_Resolve (N, Standard_Boolean);
208 end if;
209 end;
210 end Adjust_Condition;
211
212 ------------------------
213 -- Adjust_Result_Type --
214 ------------------------
215
216 procedure Adjust_Result_Type (N : Node_Id; T : Entity_Id) is
217 begin
218 -- Ignore call if current type is not Standard.Boolean
219
220 if Etype (N) /= Standard_Boolean then
221 return;
222 end if;
223
224 -- If result is already of correct type, nothing to do. Note that
225 -- this will get the most common case where everything has a type
226 -- of Standard.Boolean.
227
228 if Base_Type (T) = Standard_Boolean then
229 return;
230
231 else
232 declare
233 KP : constant Node_Kind := Nkind (Parent (N));
234
235 begin
236 -- If result is to be used as a Condition in the syntax, no need
237 -- to convert it back, since if it was changed to Standard.Boolean
238 -- using Adjust_Condition, that is just fine for this usage.
239
240 if KP in N_Raise_xxx_Error or else KP in N_Has_Condition then
241 return;
242
243 -- If result is an operand of another logical operation, no need
244 -- to reset its type, since Standard.Boolean is just fine, and
245 -- such operations always do Adjust_Condition on their operands.
246
247 elsif KP in N_Op_Boolean
248 or else KP = N_And_Then
249 or else KP = N_Or_Else
250 or else KP = N_Op_Not
251 then
252 return;
253
254 -- Otherwise we perform a conversion from the current type,
255 -- which must be Standard.Boolean, to the desired type.
256
257 else
258 Set_Analyzed (N);
259 Rewrite (N, Convert_To (T, N));
260 Analyze_And_Resolve (N, T);
261 end if;
262 end;
263 end if;
264 end Adjust_Result_Type;
265
266 --------------------------
267 -- Append_Freeze_Action --
268 --------------------------
269
270 procedure Append_Freeze_Action (T : Entity_Id; N : Node_Id) is
271 Fnode : Node_Id;
272
273 begin
274 Ensure_Freeze_Node (T);
275 Fnode := Freeze_Node (T);
276
277 if No (Actions (Fnode)) then
278 Set_Actions (Fnode, New_List);
279 end if;
280
281 Append (N, Actions (Fnode));
282 end Append_Freeze_Action;
283
284 ---------------------------
285 -- Append_Freeze_Actions --
286 ---------------------------
287
288 procedure Append_Freeze_Actions (T : Entity_Id; L : List_Id) is
289 Fnode : constant Node_Id := Freeze_Node (T);
290
291 begin
292 if No (L) then
293 return;
294
295 else
296 if No (Actions (Fnode)) then
297 Set_Actions (Fnode, L);
298
299 else
300 Append_List (L, Actions (Fnode));
301 end if;
302
303 end if;
304 end Append_Freeze_Actions;
305
306 ------------------------
307 -- Build_Runtime_Call --
308 ------------------------
309
310 function Build_Runtime_Call (Loc : Source_Ptr; RE : RE_Id) return Node_Id is
311 begin
312 -- If entity is not available, we can skip making the call (this avoids
313 -- junk duplicated error messages in a number of cases).
314
315 if not RTE_Available (RE) then
316 return Make_Null_Statement (Loc);
317 else
318 return
319 Make_Procedure_Call_Statement (Loc,
320 Name => New_Reference_To (RTE (RE), Loc));
321 end if;
322 end Build_Runtime_Call;
323
324 ----------------------------
325 -- Build_Task_Array_Image --
326 ----------------------------
327
328 -- This function generates the body for a function that constructs the
329 -- image string for a task that is an array component. The function is
330 -- local to the init proc for the array type, and is called for each one
331 -- of the components. The constructed image has the form of an indexed
332 -- component, whose prefix is the outer variable of the array type.
333 -- The n-dimensional array type has known indices Index, Index2...
334 -- Id_Ref is an indexed component form created by the enclosing init proc.
335 -- Its successive indices are Val1, Val2,.. which are the loop variables
336 -- in the loops that call the individual task init proc on each component.
337
338 -- The generated function has the following structure:
339
340 -- function F return String is
341 -- Pref : string renames Task_Name;
342 -- T1 : String := Index1'Image (Val1);
343 -- ...
344 -- Tn : String := indexn'image (Valn);
345 -- Len : Integer := T1'Length + ... + Tn'Length + n + 1;
346 -- -- Len includes commas and the end parentheses.
347 -- Res : String (1..Len);
348 -- Pos : Integer := Pref'Length;
349 --
350 -- begin
351 -- Res (1 .. Pos) := Pref;
352 -- Pos := Pos + 1;
353 -- Res (Pos) := '(';
354 -- Pos := Pos + 1;
355 -- Res (Pos .. Pos + T1'Length - 1) := T1;
356 -- Pos := Pos + T1'Length;
357 -- Res (Pos) := '.';
358 -- Pos := Pos + 1;
359 -- ...
360 -- Res (Pos .. Pos + Tn'Length - 1) := Tn;
361 -- Res (Len) := ')';
362 --
363 -- return Res;
364 -- end F;
365 --
366 -- Needless to say, multidimensional arrays of tasks are rare enough
367 -- that the bulkiness of this code is not really a concern.
368
369 function Build_Task_Array_Image
370 (Loc : Source_Ptr;
371 Id_Ref : Node_Id;
372 A_Type : Entity_Id;
373 Dyn : Boolean := False) return Node_Id
374 is
375 Dims : constant Nat := Number_Dimensions (A_Type);
376 -- Number of dimensions for array of tasks
377
378 Temps : array (1 .. Dims) of Entity_Id;
379 -- Array of temporaries to hold string for each index
380
381 Indx : Node_Id;
382 -- Index expression
383
384 Len : Entity_Id;
385 -- Total length of generated name
386
387 Pos : Entity_Id;
388 -- Running index for substring assignments
389
390 Pref : Entity_Id;
391 -- Name of enclosing variable, prefix of resulting name
392
393 Res : Entity_Id;
394 -- String to hold result
395
396 Val : Node_Id;
397 -- Value of successive indices
398
399 Sum : Node_Id;
400 -- Expression to compute total size of string
401
402 T : Entity_Id;
403 -- Entity for name at one index position
404
405 Decls : List_Id := New_List;
406 Stats : List_Id := New_List;
407
408 begin
409 Pref := Make_Defining_Identifier (Loc, New_Internal_Name ('P'));
410
411 -- For a dynamic task, the name comes from the target variable.
412 -- For a static one it is a formal of the enclosing init proc.
413
414 if Dyn then
415 Get_Name_String (Chars (Entity (Prefix (Id_Ref))));
416 Append_To (Decls,
417 Make_Object_Declaration (Loc,
418 Defining_Identifier => Pref,
419 Object_Definition => New_Occurrence_Of (Standard_String, Loc),
420 Expression =>
421 Make_String_Literal (Loc,
422 Strval => String_From_Name_Buffer)));
423
424 else
425 Append_To (Decls,
426 Make_Object_Renaming_Declaration (Loc,
427 Defining_Identifier => Pref,
428 Subtype_Mark => New_Occurrence_Of (Standard_String, Loc),
429 Name => Make_Identifier (Loc, Name_uTask_Name)));
430 end if;
431
432 Indx := First_Index (A_Type);
433 Val := First (Expressions (Id_Ref));
434
435 for J in 1 .. Dims loop
436 T := Make_Defining_Identifier (Loc, New_Internal_Name ('T'));
437 Temps (J) := T;
438
439 Append_To (Decls,
440 Make_Object_Declaration (Loc,
441 Defining_Identifier => T,
442 Object_Definition => New_Occurrence_Of (Standard_String, Loc),
443 Expression =>
444 Make_Attribute_Reference (Loc,
445 Attribute_Name => Name_Image,
446 Prefix =>
447 New_Occurrence_Of (Etype (Indx), Loc),
448 Expressions => New_List (
449 New_Copy_Tree (Val)))));
450
451 Next_Index (Indx);
452 Next (Val);
453 end loop;
454
455 Sum := Make_Integer_Literal (Loc, Dims + 1);
456
457 Sum :=
458 Make_Op_Add (Loc,
459 Left_Opnd => Sum,
460 Right_Opnd =>
461 Make_Attribute_Reference (Loc,
462 Attribute_Name => Name_Length,
463 Prefix =>
464 New_Occurrence_Of (Pref, Loc),
465 Expressions => New_List (Make_Integer_Literal (Loc, 1))));
466
467 for J in 1 .. Dims loop
468 Sum :=
469 Make_Op_Add (Loc,
470 Left_Opnd => Sum,
471 Right_Opnd =>
472 Make_Attribute_Reference (Loc,
473 Attribute_Name => Name_Length,
474 Prefix =>
475 New_Occurrence_Of (Temps (J), Loc),
476 Expressions => New_List (Make_Integer_Literal (Loc, 1))));
477 end loop;
478
479 Build_Task_Image_Prefix (Loc, Len, Res, Pos, Pref, Sum, Decls, Stats);
480
481 Set_Character_Literal_Name (Char_Code (Character'Pos ('(')));
482
483 Append_To (Stats,
484 Make_Assignment_Statement (Loc,
485 Name => Make_Indexed_Component (Loc,
486 Prefix => New_Occurrence_Of (Res, Loc),
487 Expressions => New_List (New_Occurrence_Of (Pos, Loc))),
488 Expression =>
489 Make_Character_Literal (Loc,
490 Chars => Name_Find,
491 Char_Literal_Value =>
492 UI_From_Int (Character'Pos ('(')))));
493
494 Append_To (Stats,
495 Make_Assignment_Statement (Loc,
496 Name => New_Occurrence_Of (Pos, Loc),
497 Expression =>
498 Make_Op_Add (Loc,
499 Left_Opnd => New_Occurrence_Of (Pos, Loc),
500 Right_Opnd => Make_Integer_Literal (Loc, 1))));
501
502 for J in 1 .. Dims loop
503
504 Append_To (Stats,
505 Make_Assignment_Statement (Loc,
506 Name => Make_Slice (Loc,
507 Prefix => New_Occurrence_Of (Res, Loc),
508 Discrete_Range =>
509 Make_Range (Loc,
510 Low_Bound => New_Occurrence_Of (Pos, Loc),
511 High_Bound => Make_Op_Subtract (Loc,
512 Left_Opnd =>
513 Make_Op_Add (Loc,
514 Left_Opnd => New_Occurrence_Of (Pos, Loc),
515 Right_Opnd =>
516 Make_Attribute_Reference (Loc,
517 Attribute_Name => Name_Length,
518 Prefix =>
519 New_Occurrence_Of (Temps (J), Loc),
520 Expressions =>
521 New_List (Make_Integer_Literal (Loc, 1)))),
522 Right_Opnd => Make_Integer_Literal (Loc, 1)))),
523
524 Expression => New_Occurrence_Of (Temps (J), Loc)));
525
526 if J < Dims then
527 Append_To (Stats,
528 Make_Assignment_Statement (Loc,
529 Name => New_Occurrence_Of (Pos, Loc),
530 Expression =>
531 Make_Op_Add (Loc,
532 Left_Opnd => New_Occurrence_Of (Pos, Loc),
533 Right_Opnd =>
534 Make_Attribute_Reference (Loc,
535 Attribute_Name => Name_Length,
536 Prefix => New_Occurrence_Of (Temps (J), Loc),
537 Expressions =>
538 New_List (Make_Integer_Literal (Loc, 1))))));
539
540 Set_Character_Literal_Name (Char_Code (Character'Pos (',')));
541
542 Append_To (Stats,
543 Make_Assignment_Statement (Loc,
544 Name => Make_Indexed_Component (Loc,
545 Prefix => New_Occurrence_Of (Res, Loc),
546 Expressions => New_List (New_Occurrence_Of (Pos, Loc))),
547 Expression =>
548 Make_Character_Literal (Loc,
549 Chars => Name_Find,
550 Char_Literal_Value =>
551 UI_From_Int (Character'Pos (',')))));
552
553 Append_To (Stats,
554 Make_Assignment_Statement (Loc,
555 Name => New_Occurrence_Of (Pos, Loc),
556 Expression =>
557 Make_Op_Add (Loc,
558 Left_Opnd => New_Occurrence_Of (Pos, Loc),
559 Right_Opnd => Make_Integer_Literal (Loc, 1))));
560 end if;
561 end loop;
562
563 Set_Character_Literal_Name (Char_Code (Character'Pos (')')));
564
565 Append_To (Stats,
566 Make_Assignment_Statement (Loc,
567 Name => Make_Indexed_Component (Loc,
568 Prefix => New_Occurrence_Of (Res, Loc),
569 Expressions => New_List (New_Occurrence_Of (Len, Loc))),
570 Expression =>
571 Make_Character_Literal (Loc,
572 Chars => Name_Find,
573 Char_Literal_Value =>
574 UI_From_Int (Character'Pos (')')))));
575 return Build_Task_Image_Function (Loc, Decls, Stats, Res);
576 end Build_Task_Array_Image;
577
578 ----------------------------
579 -- Build_Task_Image_Decls --
580 ----------------------------
581
582 function Build_Task_Image_Decls
583 (Loc : Source_Ptr;
584 Id_Ref : Node_Id;
585 A_Type : Entity_Id;
586 In_Init_Proc : Boolean := False) return List_Id
587 is
588 Decls : constant List_Id := New_List;
589 T_Id : Entity_Id := Empty;
590 Decl : Node_Id;
591 Expr : Node_Id := Empty;
592 Fun : Node_Id := Empty;
593 Is_Dyn : constant Boolean :=
594 Nkind (Parent (Id_Ref)) = N_Assignment_Statement
595 and then
596 Nkind (Expression (Parent (Id_Ref))) = N_Allocator;
597
598 begin
599 -- If Discard_Names or No_Implicit_Heap_Allocations are in effect,
600 -- generate a dummy declaration only.
601
602 if Restriction_Active (No_Implicit_Heap_Allocations)
603 or else Global_Discard_Names
604 then
605 T_Id := Make_Defining_Identifier (Loc, New_Internal_Name ('J'));
606 Name_Len := 0;
607
608 return
609 New_List (
610 Make_Object_Declaration (Loc,
611 Defining_Identifier => T_Id,
612 Object_Definition => New_Occurrence_Of (Standard_String, Loc),
613 Expression =>
614 Make_String_Literal (Loc,
615 Strval => String_From_Name_Buffer)));
616
617 else
618 if Nkind (Id_Ref) = N_Identifier
619 or else Nkind (Id_Ref) = N_Defining_Identifier
620 then
621 -- For a simple variable, the image of the task is built from
622 -- the name of the variable. To avoid possible conflict with
623 -- the anonymous type created for a single protected object,
624 -- add a numeric suffix.
625
626 T_Id :=
627 Make_Defining_Identifier (Loc,
628 New_External_Name (Chars (Id_Ref), 'T', 1));
629
630 Get_Name_String (Chars (Id_Ref));
631
632 Expr :=
633 Make_String_Literal (Loc,
634 Strval => String_From_Name_Buffer);
635
636 elsif Nkind (Id_Ref) = N_Selected_Component then
637 T_Id :=
638 Make_Defining_Identifier (Loc,
639 New_External_Name (Chars (Selector_Name (Id_Ref)), 'T'));
640 Fun := Build_Task_Record_Image (Loc, Id_Ref, Is_Dyn);
641
642 elsif Nkind (Id_Ref) = N_Indexed_Component then
643 T_Id :=
644 Make_Defining_Identifier (Loc,
645 New_External_Name (Chars (A_Type), 'N'));
646
647 Fun := Build_Task_Array_Image (Loc, Id_Ref, A_Type, Is_Dyn);
648 end if;
649 end if;
650
651 if Present (Fun) then
652 Append (Fun, Decls);
653 Expr := Make_Function_Call (Loc,
654 Name => New_Occurrence_Of (Defining_Entity (Fun), Loc));
655
656 if not In_Init_Proc then
657 Set_Uses_Sec_Stack (Defining_Entity (Fun));
658 end if;
659 end if;
660
661 Decl := Make_Object_Declaration (Loc,
662 Defining_Identifier => T_Id,
663 Object_Definition => New_Occurrence_Of (Standard_String, Loc),
664 Constant_Present => True,
665 Expression => Expr);
666
667 Append (Decl, Decls);
668 return Decls;
669 end Build_Task_Image_Decls;
670
671 -------------------------------
672 -- Build_Task_Image_Function --
673 -------------------------------
674
675 function Build_Task_Image_Function
676 (Loc : Source_Ptr;
677 Decls : List_Id;
678 Stats : List_Id;
679 Res : Entity_Id) return Node_Id
680 is
681 Spec : Node_Id;
682
683 begin
684 Append_To (Stats,
685 Make_Return_Statement (Loc,
686 Expression => New_Occurrence_Of (Res, Loc)));
687
688 Spec := Make_Function_Specification (Loc,
689 Defining_Unit_Name =>
690 Make_Defining_Identifier (Loc, New_Internal_Name ('F')),
691 Result_Definition => New_Occurrence_Of (Standard_String, Loc));
692
693 -- Calls to 'Image use the secondary stack, which must be cleaned
694 -- up after the task name is built.
695
696 return Make_Subprogram_Body (Loc,
697 Specification => Spec,
698 Declarations => Decls,
699 Handled_Statement_Sequence =>
700 Make_Handled_Sequence_Of_Statements (Loc, Statements => Stats));
701 end Build_Task_Image_Function;
702
703 -----------------------------
704 -- Build_Task_Image_Prefix --
705 -----------------------------
706
707 procedure Build_Task_Image_Prefix
708 (Loc : Source_Ptr;
709 Len : out Entity_Id;
710 Res : out Entity_Id;
711 Pos : out Entity_Id;
712 Prefix : Entity_Id;
713 Sum : Node_Id;
714 Decls : in out List_Id;
715 Stats : in out List_Id)
716 is
717 begin
718 Len := Make_Defining_Identifier (Loc, New_Internal_Name ('L'));
719
720 Append_To (Decls,
721 Make_Object_Declaration (Loc,
722 Defining_Identifier => Len,
723 Object_Definition => New_Occurrence_Of (Standard_Integer, Loc),
724 Expression => Sum));
725
726 Res := Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
727
728 Append_To (Decls,
729 Make_Object_Declaration (Loc,
730 Defining_Identifier => Res,
731 Object_Definition =>
732 Make_Subtype_Indication (Loc,
733 Subtype_Mark => New_Occurrence_Of (Standard_String, Loc),
734 Constraint =>
735 Make_Index_Or_Discriminant_Constraint (Loc,
736 Constraints =>
737 New_List (
738 Make_Range (Loc,
739 Low_Bound => Make_Integer_Literal (Loc, 1),
740 High_Bound => New_Occurrence_Of (Len, Loc)))))));
741
742 Pos := Make_Defining_Identifier (Loc, New_Internal_Name ('P'));
743
744 Append_To (Decls,
745 Make_Object_Declaration (Loc,
746 Defining_Identifier => Pos,
747 Object_Definition => New_Occurrence_Of (Standard_Integer, Loc)));
748
749 -- Pos := Prefix'Length;
750
751 Append_To (Stats,
752 Make_Assignment_Statement (Loc,
753 Name => New_Occurrence_Of (Pos, Loc),
754 Expression =>
755 Make_Attribute_Reference (Loc,
756 Attribute_Name => Name_Length,
757 Prefix => New_Occurrence_Of (Prefix, Loc),
758 Expressions =>
759 New_List (Make_Integer_Literal (Loc, 1)))));
760
761 -- Res (1 .. Pos) := Prefix;
762
763 Append_To (Stats,
764 Make_Assignment_Statement (Loc,
765 Name => Make_Slice (Loc,
766 Prefix => New_Occurrence_Of (Res, Loc),
767 Discrete_Range =>
768 Make_Range (Loc,
769 Low_Bound => Make_Integer_Literal (Loc, 1),
770 High_Bound => New_Occurrence_Of (Pos, Loc))),
771
772 Expression => New_Occurrence_Of (Prefix, Loc)));
773
774 Append_To (Stats,
775 Make_Assignment_Statement (Loc,
776 Name => New_Occurrence_Of (Pos, Loc),
777 Expression =>
778 Make_Op_Add (Loc,
779 Left_Opnd => New_Occurrence_Of (Pos, Loc),
780 Right_Opnd => Make_Integer_Literal (Loc, 1))));
781 end Build_Task_Image_Prefix;
782
783 -----------------------------
784 -- Build_Task_Record_Image --
785 -----------------------------
786
787 function Build_Task_Record_Image
788 (Loc : Source_Ptr;
789 Id_Ref : Node_Id;
790 Dyn : Boolean := False) return Node_Id
791 is
792 Len : Entity_Id;
793 -- Total length of generated name
794
795 Pos : Entity_Id;
796 -- Index into result
797
798 Res : Entity_Id;
799 -- String to hold result
800
801 Pref : Entity_Id;
802 -- Name of enclosing variable, prefix of resulting name
803
804 Sum : Node_Id;
805 -- Expression to compute total size of string
806
807 Sel : Entity_Id;
808 -- Entity for selector name
809
810 Decls : List_Id := New_List;
811 Stats : List_Id := New_List;
812
813 begin
814 Pref := Make_Defining_Identifier (Loc, New_Internal_Name ('P'));
815
816 -- For a dynamic task, the name comes from the target variable.
817 -- For a static one it is a formal of the enclosing init proc.
818
819 if Dyn then
820 Get_Name_String (Chars (Entity (Prefix (Id_Ref))));
821 Append_To (Decls,
822 Make_Object_Declaration (Loc,
823 Defining_Identifier => Pref,
824 Object_Definition => New_Occurrence_Of (Standard_String, Loc),
825 Expression =>
826 Make_String_Literal (Loc,
827 Strval => String_From_Name_Buffer)));
828
829 else
830 Append_To (Decls,
831 Make_Object_Renaming_Declaration (Loc,
832 Defining_Identifier => Pref,
833 Subtype_Mark => New_Occurrence_Of (Standard_String, Loc),
834 Name => Make_Identifier (Loc, Name_uTask_Name)));
835 end if;
836
837 Sel := Make_Defining_Identifier (Loc, New_Internal_Name ('S'));
838
839 Get_Name_String (Chars (Selector_Name (Id_Ref)));
840
841 Append_To (Decls,
842 Make_Object_Declaration (Loc,
843 Defining_Identifier => Sel,
844 Object_Definition => New_Occurrence_Of (Standard_String, Loc),
845 Expression =>
846 Make_String_Literal (Loc,
847 Strval => String_From_Name_Buffer)));
848
849 Sum := Make_Integer_Literal (Loc, Nat (Name_Len + 1));
850
851 Sum :=
852 Make_Op_Add (Loc,
853 Left_Opnd => Sum,
854 Right_Opnd =>
855 Make_Attribute_Reference (Loc,
856 Attribute_Name => Name_Length,
857 Prefix =>
858 New_Occurrence_Of (Pref, Loc),
859 Expressions => New_List (Make_Integer_Literal (Loc, 1))));
860
861 Build_Task_Image_Prefix (Loc, Len, Res, Pos, Pref, Sum, Decls, Stats);
862
863 Set_Character_Literal_Name (Char_Code (Character'Pos ('.')));
864
865 -- Res (Pos) := '.';
866
867 Append_To (Stats,
868 Make_Assignment_Statement (Loc,
869 Name => Make_Indexed_Component (Loc,
870 Prefix => New_Occurrence_Of (Res, Loc),
871 Expressions => New_List (New_Occurrence_Of (Pos, Loc))),
872 Expression =>
873 Make_Character_Literal (Loc,
874 Chars => Name_Find,
875 Char_Literal_Value =>
876 UI_From_Int (Character'Pos ('.')))));
877
878 Append_To (Stats,
879 Make_Assignment_Statement (Loc,
880 Name => New_Occurrence_Of (Pos, Loc),
881 Expression =>
882 Make_Op_Add (Loc,
883 Left_Opnd => New_Occurrence_Of (Pos, Loc),
884 Right_Opnd => Make_Integer_Literal (Loc, 1))));
885
886 -- Res (Pos .. Len) := Selector;
887
888 Append_To (Stats,
889 Make_Assignment_Statement (Loc,
890 Name => Make_Slice (Loc,
891 Prefix => New_Occurrence_Of (Res, Loc),
892 Discrete_Range =>
893 Make_Range (Loc,
894 Low_Bound => New_Occurrence_Of (Pos, Loc),
895 High_Bound => New_Occurrence_Of (Len, Loc))),
896 Expression => New_Occurrence_Of (Sel, Loc)));
897
898 return Build_Task_Image_Function (Loc, Decls, Stats, Res);
899 end Build_Task_Record_Image;
900
901 ----------------------------------
902 -- Component_May_Be_Bit_Aligned --
903 ----------------------------------
904
905 function Component_May_Be_Bit_Aligned (Comp : Entity_Id) return Boolean is
906 begin
907 -- If no component clause, then everything is fine, since the
908 -- back end never bit-misaligns by default, even if there is
909 -- a pragma Packed for the record.
910
911 if No (Component_Clause (Comp)) then
912 return False;
913 end if;
914
915 -- It is only array and record types that cause trouble
916
917 if not Is_Record_Type (Etype (Comp))
918 and then not Is_Array_Type (Etype (Comp))
919 then
920 return False;
921
922 -- If we know that we have a small (64 bits or less) record
923 -- or bit-packed array, then everything is fine, since the
924 -- back end can handle these cases correctly.
925
926 elsif Esize (Comp) <= 64
927 and then (Is_Record_Type (Etype (Comp))
928 or else Is_Bit_Packed_Array (Etype (Comp)))
929 then
930 return False;
931
932 -- Otherwise if the component is not byte aligned, we
933 -- know we have the nasty unaligned case.
934
935 elsif Normalized_First_Bit (Comp) /= Uint_0
936 or else Esize (Comp) mod System_Storage_Unit /= Uint_0
937 then
938 return True;
939
940 -- If we are large and byte aligned, then OK at this level
941
942 else
943 return False;
944 end if;
945 end Component_May_Be_Bit_Aligned;
946
947 -------------------------------
948 -- Convert_To_Actual_Subtype --
949 -------------------------------
950
951 procedure Convert_To_Actual_Subtype (Exp : Entity_Id) is
952 Act_ST : Entity_Id;
953
954 begin
955 Act_ST := Get_Actual_Subtype (Exp);
956
957 if Act_ST = Etype (Exp) then
958 return;
959
960 else
961 Rewrite (Exp,
962 Convert_To (Act_ST, Relocate_Node (Exp)));
963 Analyze_And_Resolve (Exp, Act_ST);
964 end if;
965 end Convert_To_Actual_Subtype;
966
967 -----------------------------------
968 -- Current_Sem_Unit_Declarations --
969 -----------------------------------
970
971 function Current_Sem_Unit_Declarations return List_Id is
972 U : Node_Id := Unit (Cunit (Current_Sem_Unit));
973 Decls : List_Id;
974
975 begin
976 -- If the current unit is a package body, locate the visible
977 -- declarations of the package spec.
978
979 if Nkind (U) = N_Package_Body then
980 U := Unit (Library_Unit (Cunit (Current_Sem_Unit)));
981 end if;
982
983 if Nkind (U) = N_Package_Declaration then
984 U := Specification (U);
985 Decls := Visible_Declarations (U);
986
987 if No (Decls) then
988 Decls := New_List;
989 Set_Visible_Declarations (U, Decls);
990 end if;
991
992 else
993 Decls := Declarations (U);
994
995 if No (Decls) then
996 Decls := New_List;
997 Set_Declarations (U, Decls);
998 end if;
999 end if;
1000
1001 return Decls;
1002 end Current_Sem_Unit_Declarations;
1003
1004 -----------------------
1005 -- Duplicate_Subexpr --
1006 -----------------------
1007
1008 function Duplicate_Subexpr
1009 (Exp : Node_Id;
1010 Name_Req : Boolean := False) return Node_Id
1011 is
1012 begin
1013 Remove_Side_Effects (Exp, Name_Req);
1014 return New_Copy_Tree (Exp);
1015 end Duplicate_Subexpr;
1016
1017 ---------------------------------
1018 -- Duplicate_Subexpr_No_Checks --
1019 ---------------------------------
1020
1021 function Duplicate_Subexpr_No_Checks
1022 (Exp : Node_Id;
1023 Name_Req : Boolean := False) return Node_Id
1024 is
1025 New_Exp : Node_Id;
1026
1027 begin
1028 Remove_Side_Effects (Exp, Name_Req);
1029 New_Exp := New_Copy_Tree (Exp);
1030 Remove_Checks (New_Exp);
1031 return New_Exp;
1032 end Duplicate_Subexpr_No_Checks;
1033
1034 -----------------------------------
1035 -- Duplicate_Subexpr_Move_Checks --
1036 -----------------------------------
1037
1038 function Duplicate_Subexpr_Move_Checks
1039 (Exp : Node_Id;
1040 Name_Req : Boolean := False) return Node_Id
1041 is
1042 New_Exp : Node_Id;
1043
1044 begin
1045 Remove_Side_Effects (Exp, Name_Req);
1046 New_Exp := New_Copy_Tree (Exp);
1047 Remove_Checks (Exp);
1048 return New_Exp;
1049 end Duplicate_Subexpr_Move_Checks;
1050
1051 --------------------
1052 -- Ensure_Defined --
1053 --------------------
1054
1055 procedure Ensure_Defined (Typ : Entity_Id; N : Node_Id) is
1056 IR : Node_Id;
1057 P : Node_Id;
1058
1059 begin
1060 if Is_Itype (Typ) then
1061 IR := Make_Itype_Reference (Sloc (N));
1062 Set_Itype (IR, Typ);
1063
1064 if not In_Open_Scopes (Scope (Typ))
1065 and then Is_Subprogram (Current_Scope)
1066 and then Scope (Current_Scope) /= Standard_Standard
1067 then
1068 -- Insert node in front of subprogram, to avoid scope anomalies
1069 -- in gigi.
1070
1071 P := Parent (N);
1072 while Present (P)
1073 and then Nkind (P) /= N_Subprogram_Body
1074 loop
1075 P := Parent (P);
1076 end loop;
1077
1078 if Present (P) then
1079 Insert_Action (P, IR);
1080 else
1081 Insert_Action (N, IR);
1082 end if;
1083
1084 else
1085 Insert_Action (N, IR);
1086 end if;
1087 end if;
1088 end Ensure_Defined;
1089
1090 ---------------------
1091 -- Evolve_And_Then --
1092 ---------------------
1093
1094 procedure Evolve_And_Then (Cond : in out Node_Id; Cond1 : Node_Id) is
1095 begin
1096 if No (Cond) then
1097 Cond := Cond1;
1098 else
1099 Cond :=
1100 Make_And_Then (Sloc (Cond1),
1101 Left_Opnd => Cond,
1102 Right_Opnd => Cond1);
1103 end if;
1104 end Evolve_And_Then;
1105
1106 --------------------
1107 -- Evolve_Or_Else --
1108 --------------------
1109
1110 procedure Evolve_Or_Else (Cond : in out Node_Id; Cond1 : Node_Id) is
1111 begin
1112 if No (Cond) then
1113 Cond := Cond1;
1114 else
1115 Cond :=
1116 Make_Or_Else (Sloc (Cond1),
1117 Left_Opnd => Cond,
1118 Right_Opnd => Cond1);
1119 end if;
1120 end Evolve_Or_Else;
1121
1122 ------------------------------
1123 -- Expand_Subtype_From_Expr --
1124 ------------------------------
1125
1126 -- This function is applicable for both static and dynamic allocation of
1127 -- objects which are constrained by an initial expression. Basically it
1128 -- transforms an unconstrained subtype indication into a constrained one.
1129 -- The expression may also be transformed in certain cases in order to
1130 -- avoid multiple evaluation. In the static allocation case, the general
1131 -- scheme is:
1132
1133 -- Val : T := Expr;
1134
1135 -- is transformed into
1136
1137 -- Val : Constrained_Subtype_of_T := Maybe_Modified_Expr;
1138 --
1139 -- Here are the main cases :
1140 --
1141 -- <if Expr is a Slice>
1142 -- Val : T ([Index_Subtype (Expr)]) := Expr;
1143 --
1144 -- <elsif Expr is a String Literal>
1145 -- Val : T (T'First .. T'First + Length (string literal) - 1) := Expr;
1146 --
1147 -- <elsif Expr is Constrained>
1148 -- subtype T is Type_Of_Expr
1149 -- Val : T := Expr;
1150 --
1151 -- <elsif Expr is an entity_name>
1152 -- Val : T (constraints taken from Expr) := Expr;
1153 --
1154 -- <else>
1155 -- type Axxx is access all T;
1156 -- Rval : Axxx := Expr'ref;
1157 -- Val : T (constraints taken from Rval) := Rval.all;
1158
1159 -- ??? note: when the Expression is allocated in the secondary stack
1160 -- we could use it directly instead of copying it by declaring
1161 -- Val : T (...) renames Rval.all
1162
1163 procedure Expand_Subtype_From_Expr
1164 (N : Node_Id;
1165 Unc_Type : Entity_Id;
1166 Subtype_Indic : Node_Id;
1167 Exp : Node_Id)
1168 is
1169 Loc : constant Source_Ptr := Sloc (N);
1170 Exp_Typ : constant Entity_Id := Etype (Exp);
1171 T : Entity_Id;
1172
1173 begin
1174 -- In general we cannot build the subtype if expansion is disabled,
1175 -- because internal entities may not have been defined. However, to
1176 -- avoid some cascaded errors, we try to continue when the expression
1177 -- is an array (or string), because it is safe to compute the bounds.
1178 -- It is in fact required to do so even in a generic context, because
1179 -- there may be constants that depend on bounds of string literal.
1180
1181 if not Expander_Active
1182 and then (No (Etype (Exp))
1183 or else Base_Type (Etype (Exp)) /= Standard_String)
1184 then
1185 return;
1186 end if;
1187
1188 if Nkind (Exp) = N_Slice then
1189 declare
1190 Slice_Type : constant Entity_Id := Etype (First_Index (Exp_Typ));
1191
1192 begin
1193 Rewrite (Subtype_Indic,
1194 Make_Subtype_Indication (Loc,
1195 Subtype_Mark => New_Reference_To (Unc_Type, Loc),
1196 Constraint =>
1197 Make_Index_Or_Discriminant_Constraint (Loc,
1198 Constraints => New_List
1199 (New_Reference_To (Slice_Type, Loc)))));
1200
1201 -- This subtype indication may be used later for contraint checks
1202 -- we better make sure that if a variable was used as a bound of
1203 -- of the original slice, its value is frozen.
1204
1205 Force_Evaluation (Low_Bound (Scalar_Range (Slice_Type)));
1206 Force_Evaluation (High_Bound (Scalar_Range (Slice_Type)));
1207 end;
1208
1209 elsif Ekind (Exp_Typ) = E_String_Literal_Subtype then
1210 Rewrite (Subtype_Indic,
1211 Make_Subtype_Indication (Loc,
1212 Subtype_Mark => New_Reference_To (Unc_Type, Loc),
1213 Constraint =>
1214 Make_Index_Or_Discriminant_Constraint (Loc,
1215 Constraints => New_List (
1216 Make_Literal_Range (Loc,
1217 Literal_Typ => Exp_Typ)))));
1218
1219 elsif Is_Constrained (Exp_Typ)
1220 and then not Is_Class_Wide_Type (Unc_Type)
1221 then
1222 if Is_Itype (Exp_Typ) then
1223
1224 -- Within an initialization procedure, a selected component
1225 -- denotes a component of the enclosing record, and it appears
1226 -- as an actual in a call to its own initialization procedure.
1227 -- If this component depends on the outer discriminant, we must
1228 -- generate the proper actual subtype for it.
1229
1230 if Nkind (Exp) = N_Selected_Component
1231 and then Within_Init_Proc
1232 then
1233 declare
1234 Decl : constant Node_Id :=
1235 Build_Actual_Subtype_Of_Component (Exp_Typ, Exp);
1236 begin
1237 if Present (Decl) then
1238 Insert_Action (N, Decl);
1239 T := Defining_Identifier (Decl);
1240 else
1241 T := Exp_Typ;
1242 end if;
1243 end;
1244
1245 -- No need to generate a new one (new what???)
1246
1247 else
1248 T := Exp_Typ;
1249 end if;
1250
1251 else
1252 T :=
1253 Make_Defining_Identifier (Loc,
1254 Chars => New_Internal_Name ('T'));
1255
1256 Insert_Action (N,
1257 Make_Subtype_Declaration (Loc,
1258 Defining_Identifier => T,
1259 Subtype_Indication => New_Reference_To (Exp_Typ, Loc)));
1260
1261 -- This type is marked as an itype even though it has an
1262 -- explicit declaration because otherwise it can be marked
1263 -- with Is_Generic_Actual_Type and generate spurious errors.
1264 -- (see sem_ch8.Analyze_Package_Renaming and sem_type.covers)
1265
1266 Set_Is_Itype (T);
1267 Set_Associated_Node_For_Itype (T, Exp);
1268 end if;
1269
1270 Rewrite (Subtype_Indic, New_Reference_To (T, Loc));
1271
1272 -- nothing needs to be done for private types with unknown discriminants
1273 -- if the underlying type is not an unconstrained composite type.
1274
1275 elsif Is_Private_Type (Unc_Type)
1276 and then Has_Unknown_Discriminants (Unc_Type)
1277 and then (not Is_Composite_Type (Underlying_Type (Unc_Type))
1278 or else Is_Constrained (Underlying_Type (Unc_Type)))
1279 then
1280 null;
1281
1282 -- Nothing to be done for derived types with unknown discriminants if
1283 -- the parent type also has unknown discriminants.
1284
1285 elsif Is_Record_Type (Unc_Type)
1286 and then not Is_Class_Wide_Type (Unc_Type)
1287 and then Has_Unknown_Discriminants (Unc_Type)
1288 and then Has_Unknown_Discriminants (Underlying_Type (Unc_Type))
1289 then
1290 null;
1291
1292 -- Nothing to be done if the type of the expression is limited, because
1293 -- in this case the expression cannot be copied, and its use can only
1294 -- be by reference and there is no need for the actual subtype.
1295
1296 elsif Is_Limited_Type (Exp_Typ) then
1297 null;
1298
1299 else
1300 Remove_Side_Effects (Exp);
1301 Rewrite (Subtype_Indic,
1302 Make_Subtype_From_Expr (Exp, Unc_Type));
1303 end if;
1304 end Expand_Subtype_From_Expr;
1305
1306 --------------------------------
1307 -- Find_Implemented_Interface --
1308 --------------------------------
1309
1310 -- Given the following code (XXX denotes irrelevant value):
1311
1312 -- type Limd_Iface is limited interface;
1313 -- type Prot_Iface is protected interface;
1314 -- type Sync_Iface is synchronized interface;
1315
1316 -- type Parent_Subtype is new Limd_Iface and Sync_Iface with ...
1317 -- type Child_Subtype is new Parent_Subtype and Prot_Iface with ...
1318
1319 -- The following calls will return the following values:
1320
1321 -- Find_Implemented_Interface
1322 -- (Child_Subtype, Synchronized_Interface, False) -> Empty
1323
1324 -- Find_Implemented_Interface
1325 -- (Child_Subtype, Synchronized_Interface, True) -> Sync_Iface
1326
1327 -- Find_Implemented_Interface
1328 -- (Child_Subtype, Any_Synchronized_Interface, XXX) -> Prot_Iface
1329
1330 -- Find_Implemented_Interface
1331 -- (Child_Subtype, Any_Limited_Interface, XXX) -> Prot_Iface
1332
1333 function Find_Implemented_Interface
1334 (Typ : Entity_Id;
1335 Kind : Interface_Kind;
1336 Check_Parent : Boolean := False) return Entity_Id
1337 is
1338 Iface_Elmt : Elmt_Id;
1339
1340 function Interface_In_Kind
1341 (I : Entity_Id;
1342 Kind : Interface_Kind) return Boolean;
1343 -- Determine whether an interface falls into a specified kind
1344
1345 -----------------------
1346 -- Interface_In_Kind --
1347 -----------------------
1348
1349 function Interface_In_Kind
1350 (I : Entity_Id;
1351 Kind : Interface_Kind) return Boolean is
1352 begin
1353 if Is_Limited_Interface (I)
1354 and then (Kind = Any_Interface
1355 or else Kind = Any_Limited_Interface
1356 or else Kind = Limited_Interface)
1357 then
1358 return True;
1359
1360 elsif Is_Protected_Interface (I)
1361 and then (Kind = Any_Interface
1362 or else Kind = Any_Limited_Interface
1363 or else Kind = Any_Synchronized_Interface
1364 or else Kind = Protected_Interface)
1365 then
1366 return True;
1367
1368 elsif Is_Synchronized_Interface (I)
1369 and then (Kind = Any_Interface
1370 or else Kind = Any_Limited_Interface
1371 or else Kind = Synchronized_Interface)
1372 then
1373 return True;
1374
1375 elsif Is_Task_Interface (I)
1376 and then (Kind = Any_Interface
1377 or else Kind = Any_Limited_Interface
1378 or else Kind = Any_Synchronized_Interface
1379 or else Kind = Task_Interface)
1380 then
1381 return True;
1382
1383 -- Regular interface. This should be the last kind to check since
1384 -- all of the previous cases have their Is_Interface flags set.
1385
1386 elsif Is_Interface (I)
1387 and then (Kind = Any_Interface
1388 or else Kind = Iface)
1389 then
1390 return True;
1391
1392 else
1393 return False;
1394 end if;
1395 end Interface_In_Kind;
1396
1397 -- Start of processing for Find_Implemented_Interface
1398
1399 begin
1400 if not Is_Tagged_Type (Typ) then
1401 return Empty;
1402 end if;
1403
1404 -- Implementations of the form:
1405 -- Typ is new Interface ...
1406
1407 if Is_Interface (Etype (Typ))
1408 and then Interface_In_Kind (Etype (Typ), Kind)
1409 then
1410 return Etype (Typ);
1411 end if;
1412
1413 -- Implementations of the form:
1414 -- Typ is new Typ_Parent and Interface ...
1415
1416 if Present (Abstract_Interfaces (Typ)) then
1417 Iface_Elmt := First_Elmt (Abstract_Interfaces (Typ));
1418 while Present (Iface_Elmt) loop
1419 if Interface_In_Kind (Node (Iface_Elmt), Kind) then
1420 return Node (Iface_Elmt);
1421 end if;
1422
1423 Iface_Elmt := Next_Elmt (Iface_Elmt);
1424 end loop;
1425 end if;
1426
1427 -- Typ is a derived type and may implement a limited interface
1428 -- through its parent subtype. Check the parent subtype as well
1429 -- as any interfaces explicitly implemented at this level.
1430
1431 if Check_Parent
1432 and then Ekind (Typ) = E_Record_Type
1433 and then Present (Parent_Subtype (Typ))
1434 then
1435 return Find_Implemented_Interface (
1436 Parent_Subtype (Typ), Kind, Check_Parent);
1437 end if;
1438
1439 -- Typ does not implement a limited interface either at this level or
1440 -- in any of its parent subtypes.
1441
1442 return Empty;
1443 end Find_Implemented_Interface;
1444
1445 ------------------------
1446 -- Find_Interface_ADT --
1447 ------------------------
1448
1449 function Find_Interface_ADT
1450 (T : Entity_Id;
1451 Iface : Entity_Id) return Entity_Id
1452 is
1453 ADT : Elmt_Id;
1454 Found : Boolean := False;
1455 Typ : Entity_Id := T;
1456
1457 procedure Find_Secondary_Table (Typ : Entity_Id);
1458 -- Internal subprogram used to recursively climb to the ancestors
1459
1460 --------------------------
1461 -- Find_Secondary_Table --
1462 --------------------------
1463
1464 procedure Find_Secondary_Table (Typ : Entity_Id) is
1465 AI_Elmt : Elmt_Id;
1466 AI : Node_Id;
1467
1468 begin
1469 -- Climb to the ancestor (if any) handling private types
1470
1471 if Present (Full_View (Etype (Typ))) then
1472 if Full_View (Etype (Typ)) /= Typ then
1473 Find_Secondary_Table (Full_View (Etype (Typ)));
1474 end if;
1475
1476 elsif Etype (Typ) /= Typ then
1477 Find_Secondary_Table (Etype (Typ));
1478 end if;
1479
1480 -- If we already found it there is nothing else to do
1481
1482 if Found then
1483 return;
1484 end if;
1485
1486 if Present (Abstract_Interfaces (Typ))
1487 and then not Is_Empty_Elmt_List (Abstract_Interfaces (Typ))
1488 then
1489 AI_Elmt := First_Elmt (Abstract_Interfaces (Typ));
1490 while Present (AI_Elmt) loop
1491 AI := Node (AI_Elmt);
1492
1493 if AI = Iface or else Is_Ancestor (Iface, AI) then
1494 Found := True;
1495 return;
1496 end if;
1497
1498 Next_Elmt (ADT);
1499 Next_Elmt (AI_Elmt);
1500 end loop;
1501 end if;
1502 end Find_Secondary_Table;
1503
1504 -- Start of processing for Find_Interface_Tag
1505
1506 begin
1507 -- Handle private types
1508
1509 if Has_Private_Declaration (Typ)
1510 and then Present (Full_View (Typ))
1511 then
1512 Typ := Full_View (Typ);
1513 end if;
1514
1515 -- Handle access types
1516
1517 if Is_Access_Type (Typ) then
1518 Typ := Directly_Designated_Type (Typ);
1519 end if;
1520
1521 -- Handle task and protected types implementing interfaces
1522
1523 if Ekind (Typ) = E_Protected_Type
1524 or else Ekind (Typ) = E_Task_Type
1525 then
1526 Typ := Corresponding_Record_Type (Typ);
1527 end if;
1528
1529 ADT := Next_Elmt (First_Elmt (Access_Disp_Table (Typ)));
1530 pragma Assert (Present (Node (ADT)));
1531 Find_Secondary_Table (Typ);
1532 pragma Assert (Found);
1533 return Node (ADT);
1534 end Find_Interface_ADT;
1535
1536 ------------------------
1537 -- Find_Interface_Tag --
1538 ------------------------
1539
1540 function Find_Interface_Tag
1541 (T : Entity_Id;
1542 Iface : Entity_Id) return Entity_Id
1543 is
1544 AI_Tag : Entity_Id;
1545 Found : Boolean := False;
1546 Typ : Entity_Id := T;
1547
1548 procedure Find_Tag (Typ : Entity_Id);
1549 -- Internal subprogram used to recursively climb to the ancestors
1550
1551 --------------
1552 -- Find_Tag --
1553 --------------
1554
1555 procedure Find_Tag (Typ : Entity_Id) is
1556 AI_Elmt : Elmt_Id;
1557 AI : Node_Id;
1558
1559 begin
1560 -- Check if the interface is an immediate ancestor of the type and
1561 -- therefore shares the main tag.
1562
1563 if Typ = Iface then
1564 pragma Assert (Etype (First_Tag_Component (Typ)) = RTE (RE_Tag));
1565 AI_Tag := First_Tag_Component (Typ);
1566 Found := True;
1567 return;
1568 end if;
1569
1570 -- Climb to the root type handling private types
1571
1572 if Present (Full_View (Etype (Typ))) then
1573 if Full_View (Etype (Typ)) /= Typ then
1574 Find_Tag (Full_View (Etype (Typ)));
1575 end if;
1576
1577 elsif Etype (Typ) /= Typ then
1578 Find_Tag (Etype (Typ));
1579 end if;
1580
1581 -- Traverse the list of interfaces implemented by the type
1582
1583 if not Found
1584 and then Present (Abstract_Interfaces (Typ))
1585 and then not (Is_Empty_Elmt_List (Abstract_Interfaces (Typ)))
1586 then
1587 -- Skip the tag associated with the primary table
1588
1589 pragma Assert (Etype (First_Tag_Component (Typ)) = RTE (RE_Tag));
1590 AI_Tag := Next_Tag_Component (First_Tag_Component (Typ));
1591 pragma Assert (Present (AI_Tag));
1592
1593 AI_Elmt := First_Elmt (Abstract_Interfaces (Typ));
1594 while Present (AI_Elmt) loop
1595 AI := Node (AI_Elmt);
1596
1597 if AI = Iface or else Is_Ancestor (Iface, AI) then
1598 Found := True;
1599 return;
1600 end if;
1601
1602 AI_Tag := Next_Tag_Component (AI_Tag);
1603 Next_Elmt (AI_Elmt);
1604 end loop;
1605 end if;
1606 end Find_Tag;
1607
1608 -- Start of processing for Find_Interface_Tag
1609
1610 begin
1611 pragma Assert (Is_Interface (Iface));
1612
1613 -- Handle private types
1614
1615 if Has_Private_Declaration (Typ)
1616 and then Present (Full_View (Typ))
1617 then
1618 Typ := Full_View (Typ);
1619 end if;
1620
1621 -- Handle access types
1622
1623 if Is_Access_Type (Typ) then
1624 Typ := Directly_Designated_Type (Typ);
1625 end if;
1626
1627 -- Handle task and protected types implementing interfaces
1628
1629 if Is_Concurrent_Type (Typ) then
1630 Typ := Corresponding_Record_Type (Typ);
1631 end if;
1632
1633 if Is_Class_Wide_Type (Typ) then
1634 Typ := Etype (Typ);
1635 end if;
1636
1637 -- Handle entities from the limited view
1638
1639 if Ekind (Typ) = E_Incomplete_Type then
1640 pragma Assert (Present (Non_Limited_View (Typ)));
1641 Typ := Non_Limited_View (Typ);
1642 end if;
1643
1644 Find_Tag (Typ);
1645 pragma Assert (Found);
1646 return AI_Tag;
1647 end Find_Interface_Tag;
1648
1649 --------------------
1650 -- Find_Interface --
1651 --------------------
1652
1653 function Find_Interface
1654 (T : Entity_Id;
1655 Comp : Entity_Id) return Entity_Id
1656 is
1657 AI_Tag : Entity_Id;
1658 Found : Boolean := False;
1659 Iface : Entity_Id;
1660 Typ : Entity_Id := T;
1661
1662 procedure Find_Iface (Typ : Entity_Id);
1663 -- Internal subprogram used to recursively climb to the ancestors
1664
1665 ----------------
1666 -- Find_Iface --
1667 ----------------
1668
1669 procedure Find_Iface (Typ : Entity_Id) is
1670 AI_Elmt : Elmt_Id;
1671
1672 begin
1673 -- Climb to the root type
1674
1675 if Etype (Typ) /= Typ then
1676 Find_Iface (Etype (Typ));
1677 end if;
1678
1679 -- Traverse the list of interfaces implemented by the type
1680
1681 if not Found
1682 and then Present (Abstract_Interfaces (Typ))
1683 and then not (Is_Empty_Elmt_List (Abstract_Interfaces (Typ)))
1684 then
1685 -- Skip the tag associated with the primary table
1686
1687 pragma Assert (Etype (First_Tag_Component (Typ)) = RTE (RE_Tag));
1688 AI_Tag := Next_Tag_Component (First_Tag_Component (Typ));
1689 pragma Assert (Present (AI_Tag));
1690
1691 AI_Elmt := First_Elmt (Abstract_Interfaces (Typ));
1692 while Present (AI_Elmt) loop
1693 if AI_Tag = Comp then
1694 Iface := Node (AI_Elmt);
1695 Found := True;
1696 return;
1697 end if;
1698
1699 AI_Tag := Next_Tag_Component (AI_Tag);
1700 Next_Elmt (AI_Elmt);
1701 end loop;
1702 end if;
1703 end Find_Iface;
1704
1705 -- Start of processing for Find_Interface
1706
1707 begin
1708 -- Handle private types
1709
1710 if Has_Private_Declaration (Typ)
1711 and then Present (Full_View (Typ))
1712 then
1713 Typ := Full_View (Typ);
1714 end if;
1715
1716 -- Handle access types
1717
1718 if Is_Access_Type (Typ) then
1719 Typ := Directly_Designated_Type (Typ);
1720 end if;
1721
1722 -- Handle task and protected types implementing interfaces
1723
1724 if Is_Concurrent_Type (Typ) then
1725 Typ := Corresponding_Record_Type (Typ);
1726 end if;
1727
1728 if Is_Class_Wide_Type (Typ) then
1729 Typ := Etype (Typ);
1730 end if;
1731
1732 -- Handle entities from the limited view
1733
1734 if Ekind (Typ) = E_Incomplete_Type then
1735 pragma Assert (Present (Non_Limited_View (Typ)));
1736 Typ := Non_Limited_View (Typ);
1737 end if;
1738
1739 Find_Iface (Typ);
1740 pragma Assert (Found);
1741 return Iface;
1742 end Find_Interface;
1743
1744 ------------------
1745 -- Find_Prim_Op --
1746 ------------------
1747
1748 function Find_Prim_Op (T : Entity_Id; Name : Name_Id) return Entity_Id is
1749 Prim : Elmt_Id;
1750 Typ : Entity_Id := T;
1751 Op : Entity_Id;
1752
1753 begin
1754 if Is_Class_Wide_Type (Typ) then
1755 Typ := Root_Type (Typ);
1756 end if;
1757
1758 Typ := Underlying_Type (Typ);
1759
1760 -- Loop through primitive operations
1761
1762 Prim := First_Elmt (Primitive_Operations (Typ));
1763 while Present (Prim) loop
1764 Op := Node (Prim);
1765
1766 -- We can retrieve primitive operations by name if it is an internal
1767 -- name. For equality we must check that both of its operands have
1768 -- the same type, to avoid confusion with user-defined equalities
1769 -- than may have a non-symmetric signature.
1770
1771 exit when Chars (Op) = Name
1772 and then
1773 (Name /= Name_Op_Eq
1774 or else Etype (First_Entity (Op)) = Etype (Last_Entity (Op)));
1775
1776 Next_Elmt (Prim);
1777 pragma Assert (Present (Prim));
1778 end loop;
1779
1780 return Node (Prim);
1781 end Find_Prim_Op;
1782
1783 function Find_Prim_Op
1784 (T : Entity_Id;
1785 Name : TSS_Name_Type) return Entity_Id
1786 is
1787 Prim : Elmt_Id;
1788 Typ : Entity_Id := T;
1789
1790 begin
1791 if Is_Class_Wide_Type (Typ) then
1792 Typ := Root_Type (Typ);
1793 end if;
1794
1795 Typ := Underlying_Type (Typ);
1796
1797 Prim := First_Elmt (Primitive_Operations (Typ));
1798 while not Is_TSS (Node (Prim), Name) loop
1799 Next_Elmt (Prim);
1800 pragma Assert (Present (Prim));
1801 end loop;
1802
1803 return Node (Prim);
1804 end Find_Prim_Op;
1805
1806 ----------------------
1807 -- Force_Evaluation --
1808 ----------------------
1809
1810 procedure Force_Evaluation (Exp : Node_Id; Name_Req : Boolean := False) is
1811 begin
1812 Remove_Side_Effects (Exp, Name_Req, Variable_Ref => True);
1813 end Force_Evaluation;
1814
1815 ------------------------
1816 -- Generate_Poll_Call --
1817 ------------------------
1818
1819 procedure Generate_Poll_Call (N : Node_Id) is
1820 begin
1821 -- No poll call if polling not active
1822
1823 if not Polling_Required then
1824 return;
1825
1826 -- Otherwise generate require poll call
1827
1828 else
1829 Insert_Before_And_Analyze (N,
1830 Make_Procedure_Call_Statement (Sloc (N),
1831 Name => New_Occurrence_Of (RTE (RE_Poll), Sloc (N))));
1832 end if;
1833 end Generate_Poll_Call;
1834
1835 ---------------------------------
1836 -- Get_Current_Value_Condition --
1837 ---------------------------------
1838
1839 -- Note: the implementation of this procedure is very closely tied to the
1840 -- implementation of Set_Current_Value_Condition. In the Get procedure, we
1841 -- interpret Current_Value fields set by the Set procedure, so the two
1842 -- procedures need to be closely coordinated.
1843
1844 procedure Get_Current_Value_Condition
1845 (Var : Node_Id;
1846 Op : out Node_Kind;
1847 Val : out Node_Id)
1848 is
1849 Loc : constant Source_Ptr := Sloc (Var);
1850 Ent : constant Entity_Id := Entity (Var);
1851
1852 procedure Process_Current_Value_Condition
1853 (N : Node_Id;
1854 S : Boolean);
1855 -- N is an expression which holds either True (S = True) or False (S =
1856 -- False) in the condition. This procedure digs out the expression and
1857 -- if it refers to Ent, sets Op and Val appropriately.
1858
1859 -------------------------------------
1860 -- Process_Current_Value_Condition --
1861 -------------------------------------
1862
1863 procedure Process_Current_Value_Condition
1864 (N : Node_Id;
1865 S : Boolean)
1866 is
1867 Cond : Node_Id;
1868 Sens : Boolean;
1869
1870 begin
1871 Cond := N;
1872 Sens := S;
1873
1874 -- Deal with NOT operators, inverting sense
1875
1876 while Nkind (Cond) = N_Op_Not loop
1877 Cond := Right_Opnd (Cond);
1878 Sens := not Sens;
1879 end loop;
1880
1881 -- Deal with AND THEN and AND cases
1882
1883 if Nkind (Cond) = N_And_Then
1884 or else Nkind (Cond) = N_Op_And
1885 then
1886 -- Don't ever try to invert a condition that is of the form
1887 -- of an AND or AND THEN (since we are not doing sufficiently
1888 -- general processing to allow this).
1889
1890 if Sens = False then
1891 Op := N_Empty;
1892 Val := Empty;
1893 return;
1894 end if;
1895
1896 -- Recursively process AND and AND THEN branches
1897
1898 Process_Current_Value_Condition (Left_Opnd (Cond), True);
1899
1900 if Op /= N_Empty then
1901 return;
1902 end if;
1903
1904 Process_Current_Value_Condition (Right_Opnd (Cond), True);
1905 return;
1906
1907 -- Case of relational operator
1908
1909 elsif Nkind (Cond) in N_Op_Compare then
1910 Op := Nkind (Cond);
1911
1912 -- Invert sense of test if inverted test
1913
1914 if Sens = False then
1915 case Op is
1916 when N_Op_Eq => Op := N_Op_Ne;
1917 when N_Op_Ne => Op := N_Op_Eq;
1918 when N_Op_Lt => Op := N_Op_Ge;
1919 when N_Op_Gt => Op := N_Op_Le;
1920 when N_Op_Le => Op := N_Op_Gt;
1921 when N_Op_Ge => Op := N_Op_Lt;
1922 when others => raise Program_Error;
1923 end case;
1924 end if;
1925
1926 -- Case of entity op value
1927
1928 if Is_Entity_Name (Left_Opnd (Cond))
1929 and then Ent = Entity (Left_Opnd (Cond))
1930 and then Compile_Time_Known_Value (Right_Opnd (Cond))
1931 then
1932 Val := Right_Opnd (Cond);
1933
1934 -- Case of value op entity
1935
1936 elsif Is_Entity_Name (Right_Opnd (Cond))
1937 and then Ent = Entity (Right_Opnd (Cond))
1938 and then Compile_Time_Known_Value (Left_Opnd (Cond))
1939 then
1940 Val := Left_Opnd (Cond);
1941
1942 -- We are effectively swapping operands
1943
1944 case Op is
1945 when N_Op_Eq => null;
1946 when N_Op_Ne => null;
1947 when N_Op_Lt => Op := N_Op_Gt;
1948 when N_Op_Gt => Op := N_Op_Lt;
1949 when N_Op_Le => Op := N_Op_Ge;
1950 when N_Op_Ge => Op := N_Op_Le;
1951 when others => raise Program_Error;
1952 end case;
1953
1954 else
1955 Op := N_Empty;
1956 end if;
1957
1958 return;
1959
1960 -- Case of Boolean variable reference, return as though the
1961 -- reference had said var = True.
1962
1963 else
1964 if Is_Entity_Name (Cond)
1965 and then Ent = Entity (Cond)
1966 then
1967 Val := New_Occurrence_Of (Standard_True, Sloc (Cond));
1968
1969 if Sens = False then
1970 Op := N_Op_Ne;
1971 else
1972 Op := N_Op_Eq;
1973 end if;
1974 end if;
1975 end if;
1976 end Process_Current_Value_Condition;
1977
1978 -- Start of processing for Get_Current_Value_Condition
1979
1980 begin
1981 Op := N_Empty;
1982 Val := Empty;
1983
1984 -- Immediate return, nothing doing, if this is not an object
1985
1986 if Ekind (Ent) not in Object_Kind then
1987 return;
1988 end if;
1989
1990 -- Otherwise examine current value
1991
1992 declare
1993 CV : constant Node_Id := Current_Value (Ent);
1994 Sens : Boolean;
1995 Stm : Node_Id;
1996
1997 begin
1998 -- If statement. Condition is known true in THEN section, known False
1999 -- in any ELSIF or ELSE part, and unknown outside the IF statement.
2000
2001 if Nkind (CV) = N_If_Statement then
2002
2003 -- Before start of IF statement
2004
2005 if Loc < Sloc (CV) then
2006 return;
2007
2008 -- After end of IF statement
2009
2010 elsif Loc >= Sloc (CV) + Text_Ptr (UI_To_Int (End_Span (CV))) then
2011 return;
2012 end if;
2013
2014 -- At this stage we know that we are within the IF statement, but
2015 -- unfortunately, the tree does not record the SLOC of the ELSE so
2016 -- we cannot use a simple SLOC comparison to distinguish between
2017 -- the then/else statements, so we have to climb the tree.
2018
2019 declare
2020 N : Node_Id;
2021
2022 begin
2023 N := Parent (Var);
2024 while Parent (N) /= CV loop
2025 N := Parent (N);
2026
2027 -- If we fall off the top of the tree, then that's odd, but
2028 -- perhaps it could occur in some error situation, and the
2029 -- safest response is simply to assume that the outcome of
2030 -- the condition is unknown. No point in bombing during an
2031 -- attempt to optimize things.
2032
2033 if No (N) then
2034 return;
2035 end if;
2036 end loop;
2037
2038 -- Now we have N pointing to a node whose parent is the IF
2039 -- statement in question, so now we can tell if we are within
2040 -- the THEN statements.
2041
2042 if Is_List_Member (N)
2043 and then List_Containing (N) = Then_Statements (CV)
2044 then
2045 Sens := True;
2046
2047 -- If the variable reference does not come from source, we
2048 -- cannot reliably tell whether it appears in the else part.
2049 -- In particular, if if appears in generated code for a node
2050 -- that requires finalization, it may be attached to a list
2051 -- that has not been yet inserted into the code. For now,
2052 -- treat it as unknown.
2053
2054 elsif not Comes_From_Source (N) then
2055 return;
2056
2057 -- Otherwise we must be in ELSIF or ELSE part
2058
2059 else
2060 Sens := False;
2061 end if;
2062 end;
2063
2064 -- ELSIF part. Condition is known true within the referenced
2065 -- ELSIF, known False in any subsequent ELSIF or ELSE part, and
2066 -- unknown before the ELSE part or after the IF statement.
2067
2068 elsif Nkind (CV) = N_Elsif_Part then
2069 Stm := Parent (CV);
2070
2071 -- Before start of ELSIF part
2072
2073 if Loc < Sloc (CV) then
2074 return;
2075
2076 -- After end of IF statement
2077
2078 elsif Loc >= Sloc (Stm) +
2079 Text_Ptr (UI_To_Int (End_Span (Stm)))
2080 then
2081 return;
2082 end if;
2083
2084 -- Again we lack the SLOC of the ELSE, so we need to climb the
2085 -- tree to see if we are within the ELSIF part in question.
2086
2087 declare
2088 N : Node_Id;
2089
2090 begin
2091 N := Parent (Var);
2092 while Parent (N) /= Stm loop
2093 N := Parent (N);
2094
2095 -- If we fall off the top of the tree, then that's odd, but
2096 -- perhaps it could occur in some error situation, and the
2097 -- safest response is simply to assume that the outcome of
2098 -- the condition is unknown. No point in bombing during an
2099 -- attempt to optimize things.
2100
2101 if No (N) then
2102 return;
2103 end if;
2104 end loop;
2105
2106 -- Now we have N pointing to a node whose parent is the IF
2107 -- statement in question, so see if is the ELSIF part we want.
2108 -- the THEN statements.
2109
2110 if N = CV then
2111 Sens := True;
2112
2113 -- Otherwise we must be in susbequent ELSIF or ELSE part
2114
2115 else
2116 Sens := False;
2117 end if;
2118 end;
2119
2120 -- Iteration scheme of while loop. The condition is known to be
2121 -- true within the body of the loop.
2122
2123 elsif Nkind (CV) = N_Iteration_Scheme then
2124 declare
2125 Loop_Stmt : constant Node_Id := Parent (CV);
2126
2127 begin
2128 -- Before start of body of loop
2129
2130 if Loc < Sloc (Loop_Stmt) then
2131 return;
2132
2133 -- After end of LOOP statement
2134
2135 elsif Loc >= Sloc (End_Label (Loop_Stmt)) then
2136 return;
2137
2138 -- We are within the body of the loop
2139
2140 else
2141 Sens := True;
2142 end if;
2143 end;
2144
2145 -- All other cases of Current_Value settings
2146
2147 else
2148 return;
2149 end if;
2150
2151 -- If we fall through here, then we have a reportable condition, Sens
2152 -- is True if the condition is true and False if it needs inverting.
2153
2154 Process_Current_Value_Condition (Condition (CV), Sens);
2155 end;
2156 end Get_Current_Value_Condition;
2157
2158 --------------------
2159 -- Homonym_Number --
2160 --------------------
2161
2162 function Homonym_Number (Subp : Entity_Id) return Nat is
2163 Count : Nat;
2164 Hom : Entity_Id;
2165
2166 begin
2167 Count := 1;
2168 Hom := Homonym (Subp);
2169 while Present (Hom) loop
2170 if Scope (Hom) = Scope (Subp) then
2171 Count := Count + 1;
2172 end if;
2173
2174 Hom := Homonym (Hom);
2175 end loop;
2176
2177 return Count;
2178 end Homonym_Number;
2179
2180 --------------------------
2181 -- Implements_Interface --
2182 --------------------------
2183
2184 function Implements_Interface
2185 (Typ : Entity_Id;
2186 Kind : Interface_Kind;
2187 Check_Parent : Boolean := False) return Boolean is
2188 begin
2189 return Find_Implemented_Interface (Typ, Kind, Check_Parent) /= Empty;
2190 end Implements_Interface;
2191
2192 ------------------------------
2193 -- In_Unconditional_Context --
2194 ------------------------------
2195
2196 function In_Unconditional_Context (Node : Node_Id) return Boolean is
2197 P : Node_Id;
2198
2199 begin
2200 P := Node;
2201 while Present (P) loop
2202 case Nkind (P) is
2203 when N_Subprogram_Body =>
2204 return True;
2205
2206 when N_If_Statement =>
2207 return False;
2208
2209 when N_Loop_Statement =>
2210 return False;
2211
2212 when N_Case_Statement =>
2213 return False;
2214
2215 when others =>
2216 P := Parent (P);
2217 end case;
2218 end loop;
2219
2220 return False;
2221 end In_Unconditional_Context;
2222
2223 -------------------
2224 -- Insert_Action --
2225 -------------------
2226
2227 procedure Insert_Action (Assoc_Node : Node_Id; Ins_Action : Node_Id) is
2228 begin
2229 if Present (Ins_Action) then
2230 Insert_Actions (Assoc_Node, New_List (Ins_Action));
2231 end if;
2232 end Insert_Action;
2233
2234 -- Version with check(s) suppressed
2235
2236 procedure Insert_Action
2237 (Assoc_Node : Node_Id; Ins_Action : Node_Id; Suppress : Check_Id)
2238 is
2239 begin
2240 Insert_Actions (Assoc_Node, New_List (Ins_Action), Suppress);
2241 end Insert_Action;
2242
2243 --------------------
2244 -- Insert_Actions --
2245 --------------------
2246
2247 procedure Insert_Actions (Assoc_Node : Node_Id; Ins_Actions : List_Id) is
2248 N : Node_Id;
2249 P : Node_Id;
2250
2251 Wrapped_Node : Node_Id := Empty;
2252
2253 begin
2254 if No (Ins_Actions) or else Is_Empty_List (Ins_Actions) then
2255 return;
2256 end if;
2257
2258 -- Ignore insert of actions from inside default expression in the
2259 -- special preliminary analyze mode. Any insertions at this point
2260 -- have no relevance, since we are only doing the analyze to freeze
2261 -- the types of any static expressions. See section "Handling of
2262 -- Default Expressions" in the spec of package Sem for further details.
2263
2264 if In_Default_Expression then
2265 return;
2266 end if;
2267
2268 -- If the action derives from stuff inside a record, then the actions
2269 -- are attached to the current scope, to be inserted and analyzed on
2270 -- exit from the scope. The reason for this is that we may also
2271 -- be generating freeze actions at the same time, and they must
2272 -- eventually be elaborated in the correct order.
2273
2274 if Is_Record_Type (Current_Scope)
2275 and then not Is_Frozen (Current_Scope)
2276 then
2277 if No (Scope_Stack.Table
2278 (Scope_Stack.Last).Pending_Freeze_Actions)
2279 then
2280 Scope_Stack.Table (Scope_Stack.Last).Pending_Freeze_Actions :=
2281 Ins_Actions;
2282 else
2283 Append_List
2284 (Ins_Actions,
2285 Scope_Stack.Table (Scope_Stack.Last).Pending_Freeze_Actions);
2286 end if;
2287
2288 return;
2289 end if;
2290
2291 -- We now intend to climb up the tree to find the right point to
2292 -- insert the actions. We start at Assoc_Node, unless this node is
2293 -- a subexpression in which case we start with its parent. We do this
2294 -- for two reasons. First it speeds things up. Second, if Assoc_Node
2295 -- is itself one of the special nodes like N_And_Then, then we assume
2296 -- that an initial request to insert actions for such a node does not
2297 -- expect the actions to get deposited in the node for later handling
2298 -- when the node is expanded, since clearly the node is being dealt
2299 -- with by the caller. Note that in the subexpression case, N is
2300 -- always the child we came from.
2301
2302 -- N_Raise_xxx_Error is an annoying special case, it is a statement
2303 -- if it has type Standard_Void_Type, and a subexpression otherwise.
2304 -- otherwise. Procedure attribute references are also statements.
2305
2306 if Nkind (Assoc_Node) in N_Subexpr
2307 and then (Nkind (Assoc_Node) in N_Raise_xxx_Error
2308 or else Etype (Assoc_Node) /= Standard_Void_Type)
2309 and then (Nkind (Assoc_Node) /= N_Attribute_Reference
2310 or else
2311 not Is_Procedure_Attribute_Name
2312 (Attribute_Name (Assoc_Node)))
2313 then
2314 P := Assoc_Node; -- ??? does not agree with above!
2315 N := Parent (Assoc_Node);
2316
2317 -- Non-subexpression case. Note that N is initially Empty in this
2318 -- case (N is only guaranteed Non-Empty in the subexpr case).
2319
2320 else
2321 P := Assoc_Node;
2322 N := Empty;
2323 end if;
2324
2325 -- Capture root of the transient scope
2326
2327 if Scope_Is_Transient then
2328 Wrapped_Node := Node_To_Be_Wrapped;
2329 end if;
2330
2331 loop
2332 pragma Assert (Present (P));
2333
2334 case Nkind (P) is
2335
2336 -- Case of right operand of AND THEN or OR ELSE. Put the actions
2337 -- in the Actions field of the right operand. They will be moved
2338 -- out further when the AND THEN or OR ELSE operator is expanded.
2339 -- Nothing special needs to be done for the left operand since
2340 -- in that case the actions are executed unconditionally.
2341
2342 when N_And_Then | N_Or_Else =>
2343 if N = Right_Opnd (P) then
2344 if Present (Actions (P)) then
2345 Insert_List_After_And_Analyze
2346 (Last (Actions (P)), Ins_Actions);
2347 else
2348 Set_Actions (P, Ins_Actions);
2349 Analyze_List (Actions (P));
2350 end if;
2351
2352 return;
2353 end if;
2354
2355 -- Then or Else operand of conditional expression. Add actions to
2356 -- Then_Actions or Else_Actions field as appropriate. The actions
2357 -- will be moved further out when the conditional is expanded.
2358
2359 when N_Conditional_Expression =>
2360 declare
2361 ThenX : constant Node_Id := Next (First (Expressions (P)));
2362 ElseX : constant Node_Id := Next (ThenX);
2363
2364 begin
2365 -- Actions belong to the then expression, temporarily
2366 -- place them as Then_Actions of the conditional expr.
2367 -- They will be moved to the proper place later when
2368 -- the conditional expression is expanded.
2369
2370 if N = ThenX then
2371 if Present (Then_Actions (P)) then
2372 Insert_List_After_And_Analyze
2373 (Last (Then_Actions (P)), Ins_Actions);
2374 else
2375 Set_Then_Actions (P, Ins_Actions);
2376 Analyze_List (Then_Actions (P));
2377 end if;
2378
2379 return;
2380
2381 -- Actions belong to the else expression, temporarily
2382 -- place them as Else_Actions of the conditional expr.
2383 -- They will be moved to the proper place later when
2384 -- the conditional expression is expanded.
2385
2386 elsif N = ElseX then
2387 if Present (Else_Actions (P)) then
2388 Insert_List_After_And_Analyze
2389 (Last (Else_Actions (P)), Ins_Actions);
2390 else
2391 Set_Else_Actions (P, Ins_Actions);
2392 Analyze_List (Else_Actions (P));
2393 end if;
2394
2395 return;
2396
2397 -- Actions belong to the condition. In this case they are
2398 -- unconditionally executed, and so we can continue the
2399 -- search for the proper insert point.
2400
2401 else
2402 null;
2403 end if;
2404 end;
2405
2406 -- Case of appearing in the condition of a while expression or
2407 -- elsif. We insert the actions into the Condition_Actions field.
2408 -- They will be moved further out when the while loop or elsif
2409 -- is analyzed.
2410
2411 when N_Iteration_Scheme |
2412 N_Elsif_Part
2413 =>
2414 if N = Condition (P) then
2415 if Present (Condition_Actions (P)) then
2416 Insert_List_After_And_Analyze
2417 (Last (Condition_Actions (P)), Ins_Actions);
2418 else
2419 Set_Condition_Actions (P, Ins_Actions);
2420
2421 -- Set the parent of the insert actions explicitly.
2422 -- This is not a syntactic field, but we need the
2423 -- parent field set, in particular so that freeze
2424 -- can understand that it is dealing with condition
2425 -- actions, and properly insert the freezing actions.
2426
2427 Set_Parent (Ins_Actions, P);
2428 Analyze_List (Condition_Actions (P));
2429 end if;
2430
2431 return;
2432 end if;
2433
2434 -- Statements, declarations, pragmas, representation clauses
2435
2436 when
2437 -- Statements
2438
2439 N_Procedure_Call_Statement |
2440 N_Statement_Other_Than_Procedure_Call |
2441
2442 -- Pragmas
2443
2444 N_Pragma |
2445
2446 -- Representation_Clause
2447
2448 N_At_Clause |
2449 N_Attribute_Definition_Clause |
2450 N_Enumeration_Representation_Clause |
2451 N_Record_Representation_Clause |
2452
2453 -- Declarations
2454
2455 N_Abstract_Subprogram_Declaration |
2456 N_Entry_Body |
2457 N_Exception_Declaration |
2458 N_Exception_Renaming_Declaration |
2459 N_Formal_Abstract_Subprogram_Declaration |
2460 N_Formal_Concrete_Subprogram_Declaration |
2461 N_Formal_Object_Declaration |
2462 N_Formal_Type_Declaration |
2463 N_Full_Type_Declaration |
2464 N_Function_Instantiation |
2465 N_Generic_Function_Renaming_Declaration |
2466 N_Generic_Package_Declaration |
2467 N_Generic_Package_Renaming_Declaration |
2468 N_Generic_Procedure_Renaming_Declaration |
2469 N_Generic_Subprogram_Declaration |
2470 N_Implicit_Label_Declaration |
2471 N_Incomplete_Type_Declaration |
2472 N_Number_Declaration |
2473 N_Object_Declaration |
2474 N_Object_Renaming_Declaration |
2475 N_Package_Body |
2476 N_Package_Body_Stub |
2477 N_Package_Declaration |
2478 N_Package_Instantiation |
2479 N_Package_Renaming_Declaration |
2480 N_Private_Extension_Declaration |
2481 N_Private_Type_Declaration |
2482 N_Procedure_Instantiation |
2483 N_Protected_Body_Stub |
2484 N_Protected_Type_Declaration |
2485 N_Single_Task_Declaration |
2486 N_Subprogram_Body |
2487 N_Subprogram_Body_Stub |
2488 N_Subprogram_Declaration |
2489 N_Subprogram_Renaming_Declaration |
2490 N_Subtype_Declaration |
2491 N_Task_Body |
2492 N_Task_Body_Stub |
2493 N_Task_Type_Declaration |
2494
2495 -- Freeze entity behaves like a declaration or statement
2496
2497 N_Freeze_Entity
2498 =>
2499 -- Do not insert here if the item is not a list member (this
2500 -- happens for example with a triggering statement, and the
2501 -- proper approach is to insert before the entire select).
2502
2503 if not Is_List_Member (P) then
2504 null;
2505
2506 -- Do not insert if parent of P is an N_Component_Association
2507 -- node (i.e. we are in the context of an N_Aggregate or
2508 -- N_Extension_Aggregate node. In this case we want to insert
2509 -- before the entire aggregate.
2510
2511 elsif Nkind (Parent (P)) = N_Component_Association then
2512 null;
2513
2514 -- Do not insert if the parent of P is either an N_Variant
2515 -- node or an N_Record_Definition node, meaning in either
2516 -- case that P is a member of a component list, and that
2517 -- therefore the actions should be inserted outside the
2518 -- complete record declaration.
2519
2520 elsif Nkind (Parent (P)) = N_Variant
2521 or else Nkind (Parent (P)) = N_Record_Definition
2522 then
2523 null;
2524
2525 -- Do not insert freeze nodes within the loop generated for
2526 -- an aggregate, because they may be elaborated too late for
2527 -- subsequent use in the back end: within a package spec the
2528 -- loop is part of the elaboration procedure and is only
2529 -- elaborated during the second pass.
2530 -- If the loop comes from source, or the entity is local to
2531 -- the loop itself it must remain within.
2532
2533 elsif Nkind (Parent (P)) = N_Loop_Statement
2534 and then not Comes_From_Source (Parent (P))
2535 and then Nkind (First (Ins_Actions)) = N_Freeze_Entity
2536 and then
2537 Scope (Entity (First (Ins_Actions))) /= Current_Scope
2538 then
2539 null;
2540
2541 -- Otherwise we can go ahead and do the insertion
2542
2543 elsif P = Wrapped_Node then
2544 Store_Before_Actions_In_Scope (Ins_Actions);
2545 return;
2546
2547 else
2548 Insert_List_Before_And_Analyze (P, Ins_Actions);
2549 return;
2550 end if;
2551
2552 -- A special case, N_Raise_xxx_Error can act either as a
2553 -- statement or a subexpression. We tell the difference
2554 -- by looking at the Etype. It is set to Standard_Void_Type
2555 -- in the statement case.
2556
2557 when
2558 N_Raise_xxx_Error =>
2559 if Etype (P) = Standard_Void_Type then
2560 if P = Wrapped_Node then
2561 Store_Before_Actions_In_Scope (Ins_Actions);
2562 else
2563 Insert_List_Before_And_Analyze (P, Ins_Actions);
2564 end if;
2565
2566 return;
2567
2568 -- In the subexpression case, keep climbing
2569
2570 else
2571 null;
2572 end if;
2573
2574 -- If a component association appears within a loop created for
2575 -- an array aggregate, attach the actions to the association so
2576 -- they can be subsequently inserted within the loop. For other
2577 -- component associations insert outside of the aggregate. For
2578 -- an association that will generate a loop, its Loop_Actions
2579 -- attribute is already initialized (see exp_aggr.adb).
2580
2581 -- The list of loop_actions can in turn generate additional ones,
2582 -- that are inserted before the associated node. If the associated
2583 -- node is outside the aggregate, the new actions are collected
2584 -- at the end of the loop actions, to respect the order in which
2585 -- they are to be elaborated.
2586
2587 when
2588 N_Component_Association =>
2589 if Nkind (Parent (P)) = N_Aggregate
2590 and then Present (Loop_Actions (P))
2591 then
2592 if Is_Empty_List (Loop_Actions (P)) then
2593 Set_Loop_Actions (P, Ins_Actions);
2594 Analyze_List (Ins_Actions);
2595
2596 else
2597 declare
2598 Decl : Node_Id;
2599
2600 begin
2601 -- Check whether these actions were generated
2602 -- by a declaration that is part of the loop_
2603 -- actions for the component_association.
2604
2605 Decl := Assoc_Node;
2606 while Present (Decl) loop
2607 exit when Parent (Decl) = P
2608 and then Is_List_Member (Decl)
2609 and then
2610 List_Containing (Decl) = Loop_Actions (P);
2611 Decl := Parent (Decl);
2612 end loop;
2613
2614 if Present (Decl) then
2615 Insert_List_Before_And_Analyze
2616 (Decl, Ins_Actions);
2617 else
2618 Insert_List_After_And_Analyze
2619 (Last (Loop_Actions (P)), Ins_Actions);
2620 end if;
2621 end;
2622 end if;
2623
2624 return;
2625
2626 else
2627 null;
2628 end if;
2629
2630 -- Another special case, an attribute denoting a procedure call
2631
2632 when
2633 N_Attribute_Reference =>
2634 if Is_Procedure_Attribute_Name (Attribute_Name (P)) then
2635 if P = Wrapped_Node then
2636 Store_Before_Actions_In_Scope (Ins_Actions);
2637 else
2638 Insert_List_Before_And_Analyze (P, Ins_Actions);
2639 end if;
2640
2641 return;
2642
2643 -- In the subexpression case, keep climbing
2644
2645 else
2646 null;
2647 end if;
2648
2649 -- For all other node types, keep climbing tree
2650
2651 when
2652 N_Abortable_Part |
2653 N_Accept_Alternative |
2654 N_Access_Definition |
2655 N_Access_Function_Definition |
2656 N_Access_Procedure_Definition |
2657 N_Access_To_Object_Definition |
2658 N_Aggregate |
2659 N_Allocator |
2660 N_Case_Statement_Alternative |
2661 N_Character_Literal |
2662 N_Compilation_Unit |
2663 N_Compilation_Unit_Aux |
2664 N_Component_Clause |
2665 N_Component_Declaration |
2666 N_Component_Definition |
2667 N_Component_List |
2668 N_Constrained_Array_Definition |
2669 N_Decimal_Fixed_Point_Definition |
2670 N_Defining_Character_Literal |
2671 N_Defining_Identifier |
2672 N_Defining_Operator_Symbol |
2673 N_Defining_Program_Unit_Name |
2674 N_Delay_Alternative |
2675 N_Delta_Constraint |
2676 N_Derived_Type_Definition |
2677 N_Designator |
2678 N_Digits_Constraint |
2679 N_Discriminant_Association |
2680 N_Discriminant_Specification |
2681 N_Empty |
2682 N_Entry_Body_Formal_Part |
2683 N_Entry_Call_Alternative |
2684 N_Entry_Declaration |
2685 N_Entry_Index_Specification |
2686 N_Enumeration_Type_Definition |
2687 N_Error |
2688 N_Exception_Handler |
2689 N_Expanded_Name |
2690 N_Explicit_Dereference |
2691 N_Extension_Aggregate |
2692 N_Floating_Point_Definition |
2693 N_Formal_Decimal_Fixed_Point_Definition |
2694 N_Formal_Derived_Type_Definition |
2695 N_Formal_Discrete_Type_Definition |
2696 N_Formal_Floating_Point_Definition |
2697 N_Formal_Modular_Type_Definition |
2698 N_Formal_Ordinary_Fixed_Point_Definition |
2699 N_Formal_Package_Declaration |
2700 N_Formal_Private_Type_Definition |
2701 N_Formal_Signed_Integer_Type_Definition |
2702 N_Function_Call |
2703 N_Function_Specification |
2704 N_Generic_Association |
2705 N_Handled_Sequence_Of_Statements |
2706 N_Identifier |
2707 N_In |
2708 N_Index_Or_Discriminant_Constraint |
2709 N_Indexed_Component |
2710 N_Integer_Literal |
2711 N_Itype_Reference |
2712 N_Label |
2713 N_Loop_Parameter_Specification |
2714 N_Mod_Clause |
2715 N_Modular_Type_Definition |
2716 N_Not_In |
2717 N_Null |
2718 N_Op_Abs |
2719 N_Op_Add |
2720 N_Op_And |
2721 N_Op_Concat |
2722 N_Op_Divide |
2723 N_Op_Eq |
2724 N_Op_Expon |
2725 N_Op_Ge |
2726 N_Op_Gt |
2727 N_Op_Le |
2728 N_Op_Lt |
2729 N_Op_Minus |
2730 N_Op_Mod |
2731 N_Op_Multiply |
2732 N_Op_Ne |
2733 N_Op_Not |
2734 N_Op_Or |
2735 N_Op_Plus |
2736 N_Op_Rem |
2737 N_Op_Rotate_Left |
2738 N_Op_Rotate_Right |
2739 N_Op_Shift_Left |
2740 N_Op_Shift_Right |
2741 N_Op_Shift_Right_Arithmetic |
2742 N_Op_Subtract |
2743 N_Op_Xor |
2744 N_Operator_Symbol |
2745 N_Ordinary_Fixed_Point_Definition |
2746 N_Others_Choice |
2747 N_Package_Specification |
2748 N_Parameter_Association |
2749 N_Parameter_Specification |
2750 N_Pragma_Argument_Association |
2751 N_Procedure_Specification |
2752 N_Protected_Body |
2753 N_Protected_Definition |
2754 N_Qualified_Expression |
2755 N_Range |
2756 N_Range_Constraint |
2757 N_Real_Literal |
2758 N_Real_Range_Specification |
2759 N_Record_Definition |
2760 N_Reference |
2761 N_Selected_Component |
2762 N_Signed_Integer_Type_Definition |
2763 N_Single_Protected_Declaration |
2764 N_Slice |
2765 N_String_Literal |
2766 N_Subprogram_Info |
2767 N_Subtype_Indication |
2768 N_Subunit |
2769 N_Task_Definition |
2770 N_Terminate_Alternative |
2771 N_Triggering_Alternative |
2772 N_Type_Conversion |
2773 N_Unchecked_Expression |
2774 N_Unchecked_Type_Conversion |
2775 N_Unconstrained_Array_Definition |
2776 N_Unused_At_End |
2777 N_Unused_At_Start |
2778 N_Use_Package_Clause |
2779 N_Use_Type_Clause |
2780 N_Variant |
2781 N_Variant_Part |
2782 N_Validate_Unchecked_Conversion |
2783 N_With_Clause |
2784 N_With_Type_Clause
2785 =>
2786 null;
2787
2788 end case;
2789
2790 -- Make sure that inserted actions stay in the transient scope
2791
2792 if P = Wrapped_Node then
2793 Store_Before_Actions_In_Scope (Ins_Actions);
2794 return;
2795 end if;
2796
2797 -- If we fall through above tests, keep climbing tree
2798
2799 N := P;
2800
2801 if Nkind (Parent (N)) = N_Subunit then
2802
2803 -- This is the proper body corresponding to a stub. Insertion
2804 -- must be done at the point of the stub, which is in the decla-
2805 -- tive part of the parent unit.
2806
2807 P := Corresponding_Stub (Parent (N));
2808
2809 else
2810 P := Parent (N);
2811 end if;
2812 end loop;
2813
2814 end Insert_Actions;
2815
2816 -- Version with check(s) suppressed
2817
2818 procedure Insert_Actions
2819 (Assoc_Node : Node_Id; Ins_Actions : List_Id; Suppress : Check_Id)
2820 is
2821 begin
2822 if Suppress = All_Checks then
2823 declare
2824 Svg : constant Suppress_Array := Scope_Suppress;
2825 begin
2826 Scope_Suppress := (others => True);
2827 Insert_Actions (Assoc_Node, Ins_Actions);
2828 Scope_Suppress := Svg;
2829 end;
2830
2831 else
2832 declare
2833 Svg : constant Boolean := Scope_Suppress (Suppress);
2834 begin
2835 Scope_Suppress (Suppress) := True;
2836 Insert_Actions (Assoc_Node, Ins_Actions);
2837 Scope_Suppress (Suppress) := Svg;
2838 end;
2839 end if;
2840 end Insert_Actions;
2841
2842 --------------------------
2843 -- Insert_Actions_After --
2844 --------------------------
2845
2846 procedure Insert_Actions_After
2847 (Assoc_Node : Node_Id;
2848 Ins_Actions : List_Id)
2849 is
2850 begin
2851 if Scope_Is_Transient
2852 and then Assoc_Node = Node_To_Be_Wrapped
2853 then
2854 Store_After_Actions_In_Scope (Ins_Actions);
2855 else
2856 Insert_List_After_And_Analyze (Assoc_Node, Ins_Actions);
2857 end if;
2858 end Insert_Actions_After;
2859
2860 ---------------------------------
2861 -- Insert_Library_Level_Action --
2862 ---------------------------------
2863
2864 procedure Insert_Library_Level_Action (N : Node_Id) is
2865 Aux : constant Node_Id := Aux_Decls_Node (Cunit (Main_Unit));
2866
2867 begin
2868 New_Scope (Cunit_Entity (Main_Unit));
2869
2870 if No (Actions (Aux)) then
2871 Set_Actions (Aux, New_List (N));
2872 else
2873 Append (N, Actions (Aux));
2874 end if;
2875
2876 Analyze (N);
2877 Pop_Scope;
2878 end Insert_Library_Level_Action;
2879
2880 ----------------------------------
2881 -- Insert_Library_Level_Actions --
2882 ----------------------------------
2883
2884 procedure Insert_Library_Level_Actions (L : List_Id) is
2885 Aux : constant Node_Id := Aux_Decls_Node (Cunit (Main_Unit));
2886
2887 begin
2888 if Is_Non_Empty_List (L) then
2889 New_Scope (Cunit_Entity (Main_Unit));
2890
2891 if No (Actions (Aux)) then
2892 Set_Actions (Aux, L);
2893 Analyze_List (L);
2894 else
2895 Insert_List_After_And_Analyze (Last (Actions (Aux)), L);
2896 end if;
2897
2898 Pop_Scope;
2899 end if;
2900 end Insert_Library_Level_Actions;
2901
2902 ----------------------
2903 -- Inside_Init_Proc --
2904 ----------------------
2905
2906 function Inside_Init_Proc return Boolean is
2907 S : Entity_Id;
2908
2909 begin
2910 S := Current_Scope;
2911 while Present (S)
2912 and then S /= Standard_Standard
2913 loop
2914 if Is_Init_Proc (S) then
2915 return True;
2916 else
2917 S := Scope (S);
2918 end if;
2919 end loop;
2920
2921 return False;
2922 end Inside_Init_Proc;
2923
2924 ----------------------------
2925 -- Is_All_Null_Statements --
2926 ----------------------------
2927
2928 function Is_All_Null_Statements (L : List_Id) return Boolean is
2929 Stm : Node_Id;
2930
2931 begin
2932 Stm := First (L);
2933 while Present (Stm) loop
2934 if Nkind (Stm) /= N_Null_Statement then
2935 return False;
2936 end if;
2937
2938 Next (Stm);
2939 end loop;
2940
2941 return True;
2942 end Is_All_Null_Statements;
2943
2944 -----------------------------------------
2945 -- Is_Predefined_Dispatching_Operation --
2946 -----------------------------------------
2947
2948 function Is_Predefined_Dispatching_Operation (E : Entity_Id) return Boolean
2949 is
2950 TSS_Name : TSS_Name_Type;
2951
2952 begin
2953 if not Is_Dispatching_Operation (E) then
2954 return False;
2955 end if;
2956
2957 Get_Name_String (Chars (E));
2958
2959 if Name_Len > TSS_Name_Type'Last then
2960 TSS_Name := TSS_Name_Type (Name_Buffer (Name_Len - TSS_Name'Length + 1
2961 .. Name_Len));
2962 if Chars (E) = Name_uSize
2963 or else Chars (E) = Name_uAlignment
2964 or else TSS_Name = TSS_Stream_Read
2965 or else TSS_Name = TSS_Stream_Write
2966 or else TSS_Name = TSS_Stream_Input
2967 or else TSS_Name = TSS_Stream_Output
2968 or else
2969 (Chars (E) = Name_Op_Eq
2970 and then Etype (First_Entity (E)) = Etype (Last_Entity (E)))
2971 or else Chars (E) = Name_uAssign
2972 or else TSS_Name = TSS_Deep_Adjust
2973 or else TSS_Name = TSS_Deep_Finalize
2974 or else (Ada_Version >= Ada_05
2975 and then (Chars (E) = Name_uDisp_Asynchronous_Select
2976 or else Chars (E) = Name_uDisp_Conditional_Select
2977 or else Chars (E) = Name_uDisp_Get_Prim_Op_Kind
2978 or else Chars (E) = Name_uDisp_Get_Task_Id
2979 or else Chars (E) = Name_uDisp_Timed_Select))
2980 then
2981 return True;
2982 end if;
2983 end if;
2984
2985 return False;
2986 end Is_Predefined_Dispatching_Operation;
2987
2988 ----------------------------------
2989 -- Is_Possibly_Unaligned_Object --
2990 ----------------------------------
2991
2992 function Is_Possibly_Unaligned_Object (N : Node_Id) return Boolean is
2993 T : constant Entity_Id := Etype (N);
2994
2995 begin
2996 -- If renamed object, apply test to underlying object
2997
2998 if Is_Entity_Name (N)
2999 and then Is_Object (Entity (N))
3000 and then Present (Renamed_Object (Entity (N)))
3001 then
3002 return Is_Possibly_Unaligned_Object (Renamed_Object (Entity (N)));
3003 end if;
3004
3005 -- Tagged and controlled types and aliased types are always aligned,
3006 -- as are concurrent types.
3007
3008 if Is_Aliased (T)
3009 or else Has_Controlled_Component (T)
3010 or else Is_Concurrent_Type (T)
3011 or else Is_Tagged_Type (T)
3012 or else Is_Controlled (T)
3013 then
3014 return False;
3015 end if;
3016
3017 -- If this is an element of a packed array, may be unaligned
3018
3019 if Is_Ref_To_Bit_Packed_Array (N) then
3020 return True;
3021 end if;
3022
3023 -- Case of component reference
3024
3025 if Nkind (N) = N_Selected_Component then
3026 declare
3027 P : constant Node_Id := Prefix (N);
3028 C : constant Entity_Id := Entity (Selector_Name (N));
3029 M : Nat;
3030 S : Nat;
3031
3032 begin
3033 -- If component reference is for an array with non-static bounds,
3034 -- then it is always aligned: we can only process unaligned
3035 -- arrays with static bounds (more accurately bounds known at
3036 -- compile time).
3037
3038 if Is_Array_Type (T)
3039 and then not Compile_Time_Known_Bounds (T)
3040 then
3041 return False;
3042 end if;
3043
3044 -- If component is aliased, it is definitely properly aligned
3045
3046 if Is_Aliased (C) then
3047 return False;
3048 end if;
3049
3050 -- If component is for a type implemented as a scalar, and the
3051 -- record is packed, and the component is other than the first
3052 -- component of the record, then the component may be unaligned.
3053
3054 if Is_Packed (Etype (P))
3055 and then Represented_As_Scalar (Etype (C))
3056 and then First_Entity (Scope (C)) /= C
3057 then
3058 return True;
3059 end if;
3060
3061 -- Compute maximum possible alignment for T
3062
3063 -- If alignment is known, then that settles things
3064
3065 if Known_Alignment (T) then
3066 M := UI_To_Int (Alignment (T));
3067
3068 -- If alignment is not known, tentatively set max alignment
3069
3070 else
3071 M := Ttypes.Maximum_Alignment;
3072
3073 -- We can reduce this if the Esize is known since the default
3074 -- alignment will never be more than the smallest power of 2
3075 -- that does not exceed this Esize value.
3076
3077 if Known_Esize (T) then
3078 S := UI_To_Int (Esize (T));
3079
3080 while (M / 2) >= S loop
3081 M := M / 2;
3082 end loop;
3083 end if;
3084 end if;
3085
3086 -- If the component reference is for a record that has a specified
3087 -- alignment, and we either know it is too small, or cannot tell,
3088 -- then the component may be unaligned
3089
3090 if Known_Alignment (Etype (P))
3091 and then Alignment (Etype (P)) < Ttypes.Maximum_Alignment
3092 and then M > Alignment (Etype (P))
3093 then
3094 return True;
3095 end if;
3096
3097 -- Case of component clause present which may specify an
3098 -- unaligned position.
3099
3100 if Present (Component_Clause (C)) then
3101
3102 -- Otherwise we can do a test to make sure that the actual
3103 -- start position in the record, and the length, are both
3104 -- consistent with the required alignment. If not, we know
3105 -- that we are unaligned.
3106
3107 declare
3108 Align_In_Bits : constant Nat := M * System_Storage_Unit;
3109 begin
3110 if Component_Bit_Offset (C) mod Align_In_Bits /= 0
3111 or else Esize (C) mod Align_In_Bits /= 0
3112 then
3113 return True;
3114 end if;
3115 end;
3116 end if;
3117
3118 -- Otherwise, for a component reference, test prefix
3119
3120 return Is_Possibly_Unaligned_Object (P);
3121 end;
3122
3123 -- If not a component reference, must be aligned
3124
3125 else
3126 return False;
3127 end if;
3128 end Is_Possibly_Unaligned_Object;
3129
3130 ---------------------------------
3131 -- Is_Possibly_Unaligned_Slice --
3132 ---------------------------------
3133
3134 function Is_Possibly_Unaligned_Slice (N : Node_Id) return Boolean is
3135 begin
3136 -- ??? GCC3 will eventually handle strings with arbitrary alignments,
3137 -- but for now the following check must be disabled.
3138
3139 -- if get_gcc_version >= 3 then
3140 -- return False;
3141 -- end if;
3142
3143 -- For renaming case, go to renamed object
3144
3145 if Is_Entity_Name (N)
3146 and then Is_Object (Entity (N))
3147 and then Present (Renamed_Object (Entity (N)))
3148 then
3149 return Is_Possibly_Unaligned_Slice (Renamed_Object (Entity (N)));
3150 end if;
3151
3152 -- The reference must be a slice
3153
3154 if Nkind (N) /= N_Slice then
3155 return False;
3156 end if;
3157
3158 -- Always assume the worst for a nested record component with a
3159 -- component clause, which gigi/gcc does not appear to handle well.
3160 -- It is not clear why this special test is needed at all ???
3161
3162 if Nkind (Prefix (N)) = N_Selected_Component
3163 and then Nkind (Prefix (Prefix (N))) = N_Selected_Component
3164 and then
3165 Present (Component_Clause (Entity (Selector_Name (Prefix (N)))))
3166 then
3167 return True;
3168 end if;
3169
3170 -- We only need to worry if the target has strict alignment
3171
3172 if not Target_Strict_Alignment then
3173 return False;
3174 end if;
3175
3176 -- If it is a slice, then look at the array type being sliced
3177
3178 declare
3179 Sarr : constant Node_Id := Prefix (N);
3180 -- Prefix of the slice, i.e. the array being sliced
3181
3182 Styp : constant Entity_Id := Etype (Prefix (N));
3183 -- Type of the array being sliced
3184
3185 Pref : Node_Id;
3186 Ptyp : Entity_Id;
3187
3188 begin
3189 -- The problems arise if the array object that is being sliced
3190 -- is a component of a record or array, and we cannot guarantee
3191 -- the alignment of the array within its containing object.
3192
3193 -- To investigate this, we look at successive prefixes to see
3194 -- if we have a worrisome indexed or selected component.
3195
3196 Pref := Sarr;
3197 loop
3198 -- Case of array is part of an indexed component reference
3199
3200 if Nkind (Pref) = N_Indexed_Component then
3201 Ptyp := Etype (Prefix (Pref));
3202
3203 -- The only problematic case is when the array is packed,
3204 -- in which case we really know nothing about the alignment
3205 -- of individual components.
3206
3207 if Is_Bit_Packed_Array (Ptyp) then
3208 return True;
3209 end if;
3210
3211 -- Case of array is part of a selected component reference
3212
3213 elsif Nkind (Pref) = N_Selected_Component then
3214 Ptyp := Etype (Prefix (Pref));
3215
3216 -- We are definitely in trouble if the record in question
3217 -- has an alignment, and either we know this alignment is
3218 -- inconsistent with the alignment of the slice, or we
3219 -- don't know what the alignment of the slice should be.
3220
3221 if Known_Alignment (Ptyp)
3222 and then (Unknown_Alignment (Styp)
3223 or else Alignment (Styp) > Alignment (Ptyp))
3224 then
3225 return True;
3226 end if;
3227
3228 -- We are in potential trouble if the record type is packed.
3229 -- We could special case when we know that the array is the
3230 -- first component, but that's not such a simple case ???
3231
3232 if Is_Packed (Ptyp) then
3233 return True;
3234 end if;
3235
3236 -- We are in trouble if there is a component clause, and
3237 -- either we do not know the alignment of the slice, or
3238 -- the alignment of the slice is inconsistent with the
3239 -- bit position specified by the component clause.
3240
3241 declare
3242 Field : constant Entity_Id := Entity (Selector_Name (Pref));
3243 begin
3244 if Present (Component_Clause (Field))
3245 and then
3246 (Unknown_Alignment (Styp)
3247 or else
3248 (Component_Bit_Offset (Field) mod
3249 (System_Storage_Unit * Alignment (Styp))) /= 0)
3250 then
3251 return True;
3252 end if;
3253 end;
3254
3255 -- For cases other than selected or indexed components we
3256 -- know we are OK, since no issues arise over alignment.
3257
3258 else
3259 return False;
3260 end if;
3261
3262 -- We processed an indexed component or selected component
3263 -- reference that looked safe, so keep checking prefixes.
3264
3265 Pref := Prefix (Pref);
3266 end loop;
3267 end;
3268 end Is_Possibly_Unaligned_Slice;
3269
3270 --------------------------------
3271 -- Is_Ref_To_Bit_Packed_Array --
3272 --------------------------------
3273
3274 function Is_Ref_To_Bit_Packed_Array (N : Node_Id) return Boolean is
3275 Result : Boolean;
3276 Expr : Node_Id;
3277
3278 begin
3279 if Is_Entity_Name (N)
3280 and then Is_Object (Entity (N))
3281 and then Present (Renamed_Object (Entity (N)))
3282 then
3283 return Is_Ref_To_Bit_Packed_Array (Renamed_Object (Entity (N)));
3284 end if;
3285
3286 if Nkind (N) = N_Indexed_Component
3287 or else
3288 Nkind (N) = N_Selected_Component
3289 then
3290 if Is_Bit_Packed_Array (Etype (Prefix (N))) then
3291 Result := True;
3292 else
3293 Result := Is_Ref_To_Bit_Packed_Array (Prefix (N));
3294 end if;
3295
3296 if Result and then Nkind (N) = N_Indexed_Component then
3297 Expr := First (Expressions (N));
3298 while Present (Expr) loop
3299 Force_Evaluation (Expr);
3300 Next (Expr);
3301 end loop;
3302 end if;
3303
3304 return Result;
3305
3306 else
3307 return False;
3308 end if;
3309 end Is_Ref_To_Bit_Packed_Array;
3310
3311 --------------------------------
3312 -- Is_Ref_To_Bit_Packed_Slice --
3313 --------------------------------
3314
3315 function Is_Ref_To_Bit_Packed_Slice (N : Node_Id) return Boolean is
3316 begin
3317 if Nkind (N) = N_Type_Conversion then
3318 return Is_Ref_To_Bit_Packed_Slice (Expression (N));
3319
3320 elsif Is_Entity_Name (N)
3321 and then Is_Object (Entity (N))
3322 and then Present (Renamed_Object (Entity (N)))
3323 then
3324 return Is_Ref_To_Bit_Packed_Slice (Renamed_Object (Entity (N)));
3325
3326 elsif Nkind (N) = N_Slice
3327 and then Is_Bit_Packed_Array (Etype (Prefix (N)))
3328 then
3329 return True;
3330
3331 elsif Nkind (N) = N_Indexed_Component
3332 or else
3333 Nkind (N) = N_Selected_Component
3334 then
3335 return Is_Ref_To_Bit_Packed_Slice (Prefix (N));
3336
3337 else
3338 return False;
3339 end if;
3340 end Is_Ref_To_Bit_Packed_Slice;
3341
3342 -----------------------
3343 -- Is_Renamed_Object --
3344 -----------------------
3345
3346 function Is_Renamed_Object (N : Node_Id) return Boolean is
3347 Pnod : constant Node_Id := Parent (N);
3348 Kind : constant Node_Kind := Nkind (Pnod);
3349
3350 begin
3351 if Kind = N_Object_Renaming_Declaration then
3352 return True;
3353
3354 elsif Kind = N_Indexed_Component
3355 or else Kind = N_Selected_Component
3356 then
3357 return Is_Renamed_Object (Pnod);
3358
3359 else
3360 return False;
3361 end if;
3362 end Is_Renamed_Object;
3363
3364 ----------------------------
3365 -- Is_Untagged_Derivation --
3366 ----------------------------
3367
3368 function Is_Untagged_Derivation (T : Entity_Id) return Boolean is
3369 begin
3370 return (not Is_Tagged_Type (T) and then Is_Derived_Type (T))
3371 or else
3372 (Is_Private_Type (T) and then Present (Full_View (T))
3373 and then not Is_Tagged_Type (Full_View (T))
3374 and then Is_Derived_Type (Full_View (T))
3375 and then Etype (Full_View (T)) /= T);
3376 end Is_Untagged_Derivation;
3377
3378 --------------------
3379 -- Kill_Dead_Code --
3380 --------------------
3381
3382 procedure Kill_Dead_Code (N : Node_Id; Warn : Boolean := False) is
3383 begin
3384 if Present (N) then
3385 Remove_Warning_Messages (N);
3386
3387 if Warn then
3388 Error_Msg_F
3389 ("?this code can never be executed and has been deleted", N);
3390 end if;
3391
3392 -- Recurse into block statements and bodies to process declarations
3393 -- and statements
3394
3395 if Nkind (N) = N_Block_Statement
3396 or else Nkind (N) = N_Subprogram_Body
3397 or else Nkind (N) = N_Package_Body
3398 then
3399 Kill_Dead_Code
3400 (Declarations (N), False);
3401 Kill_Dead_Code
3402 (Statements (Handled_Statement_Sequence (N)));
3403
3404 if Nkind (N) = N_Subprogram_Body then
3405 Set_Is_Eliminated (Defining_Entity (N));
3406 end if;
3407
3408 elsif Nkind (N) = N_Package_Declaration then
3409 Kill_Dead_Code (Visible_Declarations (Specification (N)));
3410 Kill_Dead_Code (Private_Declarations (Specification (N)));
3411
3412 declare
3413 E : Entity_Id := First_Entity (Defining_Entity (N));
3414 begin
3415 while Present (E) loop
3416 if Ekind (E) = E_Operator then
3417 Set_Is_Eliminated (E);
3418 end if;
3419
3420 Next_Entity (E);
3421 end loop;
3422 end;
3423
3424 -- Recurse into composite statement to kill individual statements,
3425 -- in particular instantiations.
3426
3427 elsif Nkind (N) = N_If_Statement then
3428 Kill_Dead_Code (Then_Statements (N));
3429 Kill_Dead_Code (Elsif_Parts (N));
3430 Kill_Dead_Code (Else_Statements (N));
3431
3432 elsif Nkind (N) = N_Loop_Statement then
3433 Kill_Dead_Code (Statements (N));
3434
3435 elsif Nkind (N) = N_Case_Statement then
3436 declare
3437 Alt : Node_Id;
3438 begin
3439 Alt := First (Alternatives (N));
3440 while Present (Alt) loop
3441 Kill_Dead_Code (Statements (Alt));
3442 Next (Alt);
3443 end loop;
3444 end;
3445
3446 elsif Nkind (N) = N_Case_Statement_Alternative then
3447 Kill_Dead_Code (Statements (N));
3448
3449 -- Deal with dead instances caused by deleting instantiations
3450
3451 elsif Nkind (N) in N_Generic_Instantiation then
3452 Remove_Dead_Instance (N);
3453 end if;
3454
3455 Delete_Tree (N);
3456 end if;
3457 end Kill_Dead_Code;
3458
3459 -- Case where argument is a list of nodes to be killed
3460
3461 procedure Kill_Dead_Code (L : List_Id; Warn : Boolean := False) is
3462 N : Node_Id;
3463 W : Boolean;
3464 begin
3465 W := Warn;
3466 if Is_Non_Empty_List (L) then
3467 loop
3468 N := Remove_Head (L);
3469 exit when No (N);
3470 Kill_Dead_Code (N, W);
3471 W := False;
3472 end loop;
3473 end if;
3474 end Kill_Dead_Code;
3475
3476 ------------------------
3477 -- Known_Non_Negative --
3478 ------------------------
3479
3480 function Known_Non_Negative (Opnd : Node_Id) return Boolean is
3481 begin
3482 if Is_OK_Static_Expression (Opnd)
3483 and then Expr_Value (Opnd) >= 0
3484 then
3485 return True;
3486
3487 else
3488 declare
3489 Lo : constant Node_Id := Type_Low_Bound (Etype (Opnd));
3490
3491 begin
3492 return
3493 Is_OK_Static_Expression (Lo) and then Expr_Value (Lo) >= 0;
3494 end;
3495 end if;
3496 end Known_Non_Negative;
3497
3498 --------------------
3499 -- Known_Non_Null --
3500 --------------------
3501
3502 function Known_Non_Null (N : Node_Id) return Boolean is
3503 begin
3504 -- Checks for case where N is an entity reference
3505
3506 if Is_Entity_Name (N) and then Present (Entity (N)) then
3507 declare
3508 E : constant Entity_Id := Entity (N);
3509 Op : Node_Kind;
3510 Val : Node_Id;
3511
3512 begin
3513 -- First check if we are in decisive conditional
3514
3515 Get_Current_Value_Condition (N, Op, Val);
3516
3517 if Nkind (Val) = N_Null then
3518 if Op = N_Op_Eq then
3519 return False;
3520 elsif Op = N_Op_Ne then
3521 return True;
3522 end if;
3523 end if;
3524
3525 -- If OK to do replacement, test Is_Known_Non_Null flag
3526
3527 if OK_To_Do_Constant_Replacement (E) then
3528 return Is_Known_Non_Null (E);
3529
3530 -- Otherwise if not safe to do replacement, then say so
3531
3532 else
3533 return False;
3534 end if;
3535 end;
3536
3537 -- True if access attribute
3538
3539 elsif Nkind (N) = N_Attribute_Reference
3540 and then (Attribute_Name (N) = Name_Access
3541 or else
3542 Attribute_Name (N) = Name_Unchecked_Access
3543 or else
3544 Attribute_Name (N) = Name_Unrestricted_Access)
3545 then
3546 return True;
3547
3548 -- True if allocator
3549
3550 elsif Nkind (N) = N_Allocator then
3551 return True;
3552
3553 -- For a conversion, true if expression is known non-null
3554
3555 elsif Nkind (N) = N_Type_Conversion then
3556 return Known_Non_Null (Expression (N));
3557
3558 -- Above are all cases where the value could be determined to be
3559 -- non-null. In all other cases, we don't know, so return False.
3560
3561 else
3562 return False;
3563 end if;
3564 end Known_Non_Null;
3565
3566 ----------------
3567 -- Known_Null --
3568 ----------------
3569
3570 function Known_Null (N : Node_Id) return Boolean is
3571 begin
3572 -- Checks for case where N is an entity reference
3573
3574 if Is_Entity_Name (N) and then Present (Entity (N)) then
3575 declare
3576 E : constant Entity_Id := Entity (N);
3577 Op : Node_Kind;
3578 Val : Node_Id;
3579
3580 begin
3581 -- First check if we are in decisive conditional
3582
3583 Get_Current_Value_Condition (N, Op, Val);
3584
3585 if Nkind (Val) = N_Null then
3586 if Op = N_Op_Eq then
3587 return True;
3588 elsif Op = N_Op_Ne then
3589 return False;
3590 end if;
3591 end if;
3592
3593 -- If OK to do replacement, test Is_Known_Null flag
3594
3595 if OK_To_Do_Constant_Replacement (E) then
3596 return Is_Known_Null (E);
3597
3598 -- Otherwise if not safe to do replacement, then say so
3599
3600 else
3601 return False;
3602 end if;
3603 end;
3604
3605 -- True if explicit reference to null
3606
3607 elsif Nkind (N) = N_Null then
3608 return True;
3609
3610 -- For a conversion, true if expression is known null
3611
3612 elsif Nkind (N) = N_Type_Conversion then
3613 return Known_Null (Expression (N));
3614
3615 -- Above are all cases where the value could be determined to be null.
3616 -- In all other cases, we don't know, so return False.
3617
3618 else
3619 return False;
3620 end if;
3621 end Known_Null;
3622
3623 -----------------------------
3624 -- Make_CW_Equivalent_Type --
3625 -----------------------------
3626
3627 -- Create a record type used as an equivalent of any member
3628 -- of the class which takes its size from exp.
3629
3630 -- Generate the following code:
3631
3632 -- type Equiv_T is record
3633 -- _parent : T (List of discriminant constaints taken from Exp);
3634 -- Ext__50 : Storage_Array (1 .. (Exp'size - Typ'object_size)/8);
3635 -- end Equiv_T;
3636 --
3637 -- ??? Note that this type does not guarantee same alignment as all
3638 -- derived types
3639
3640 function Make_CW_Equivalent_Type
3641 (T : Entity_Id;
3642 E : Node_Id) return Entity_Id
3643 is
3644 Loc : constant Source_Ptr := Sloc (E);
3645 Root_Typ : constant Entity_Id := Root_Type (T);
3646 List_Def : constant List_Id := Empty_List;
3647 Equiv_Type : Entity_Id;
3648 Range_Type : Entity_Id;
3649 Str_Type : Entity_Id;
3650 Constr_Root : Entity_Id;
3651 Sizexpr : Node_Id;
3652
3653 begin
3654 if not Has_Discriminants (Root_Typ) then
3655 Constr_Root := Root_Typ;
3656 else
3657 Constr_Root :=
3658 Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
3659
3660 -- subtype cstr__n is T (List of discr constraints taken from Exp)
3661
3662 Append_To (List_Def,
3663 Make_Subtype_Declaration (Loc,
3664 Defining_Identifier => Constr_Root,
3665 Subtype_Indication =>
3666 Make_Subtype_From_Expr (E, Root_Typ)));
3667 end if;
3668
3669 -- subtype rg__xx is Storage_Offset range
3670 -- (Expr'size - typ'size) / Storage_Unit
3671
3672 Range_Type := Make_Defining_Identifier (Loc, New_Internal_Name ('G'));
3673
3674 Sizexpr :=
3675 Make_Op_Subtract (Loc,
3676 Left_Opnd =>
3677 Make_Attribute_Reference (Loc,
3678 Prefix =>
3679 OK_Convert_To (T, Duplicate_Subexpr_No_Checks (E)),
3680 Attribute_Name => Name_Size),
3681 Right_Opnd =>
3682 Make_Attribute_Reference (Loc,
3683 Prefix => New_Reference_To (Constr_Root, Loc),
3684 Attribute_Name => Name_Object_Size));
3685
3686 Set_Paren_Count (Sizexpr, 1);
3687
3688 Append_To (List_Def,
3689 Make_Subtype_Declaration (Loc,
3690 Defining_Identifier => Range_Type,
3691 Subtype_Indication =>
3692 Make_Subtype_Indication (Loc,
3693 Subtype_Mark => New_Reference_To (RTE (RE_Storage_Offset), Loc),
3694 Constraint => Make_Range_Constraint (Loc,
3695 Range_Expression =>
3696 Make_Range (Loc,
3697 Low_Bound => Make_Integer_Literal (Loc, 1),
3698 High_Bound =>
3699 Make_Op_Divide (Loc,
3700 Left_Opnd => Sizexpr,
3701 Right_Opnd => Make_Integer_Literal (Loc,
3702 Intval => System_Storage_Unit)))))));
3703
3704 -- subtype str__nn is Storage_Array (rg__x);
3705
3706 Str_Type := Make_Defining_Identifier (Loc, New_Internal_Name ('S'));
3707 Append_To (List_Def,
3708 Make_Subtype_Declaration (Loc,
3709 Defining_Identifier => Str_Type,
3710 Subtype_Indication =>
3711 Make_Subtype_Indication (Loc,
3712 Subtype_Mark => New_Reference_To (RTE (RE_Storage_Array), Loc),
3713 Constraint =>
3714 Make_Index_Or_Discriminant_Constraint (Loc,
3715 Constraints =>
3716 New_List (New_Reference_To (Range_Type, Loc))))));
3717
3718 -- type Equiv_T is record
3719 -- _parent : Tnn;
3720 -- E : Str_Type;
3721 -- end Equiv_T;
3722
3723 Equiv_Type := Make_Defining_Identifier (Loc, New_Internal_Name ('T'));
3724
3725 -- When the target requires front-end layout, it's necessary to allow
3726 -- the equivalent type to be frozen so that layout can occur (when the
3727 -- associated class-wide subtype is frozen, the equivalent type will
3728 -- be frozen, see freeze.adb). For other targets, Gigi wants to have
3729 -- the equivalent type marked as frozen and deals with this type itself.
3730 -- In the Gigi case this will also avoid the generation of an init
3731 -- procedure for the type.
3732
3733 if not Frontend_Layout_On_Target then
3734 Set_Is_Frozen (Equiv_Type);
3735 end if;
3736
3737 Set_Ekind (Equiv_Type, E_Record_Type);
3738 Set_Parent_Subtype (Equiv_Type, Constr_Root);
3739
3740 Append_To (List_Def,
3741 Make_Full_Type_Declaration (Loc,
3742 Defining_Identifier => Equiv_Type,
3743
3744 Type_Definition =>
3745 Make_Record_Definition (Loc,
3746 Component_List => Make_Component_List (Loc,
3747 Component_Items => New_List (
3748 Make_Component_Declaration (Loc,
3749 Defining_Identifier =>
3750 Make_Defining_Identifier (Loc, Name_uParent),
3751 Component_Definition =>
3752 Make_Component_Definition (Loc,
3753 Aliased_Present => False,
3754 Subtype_Indication =>
3755 New_Reference_To (Constr_Root, Loc))),
3756
3757 Make_Component_Declaration (Loc,
3758 Defining_Identifier =>
3759 Make_Defining_Identifier (Loc,
3760 Chars => New_Internal_Name ('C')),
3761 Component_Definition =>
3762 Make_Component_Definition (Loc,
3763 Aliased_Present => False,
3764 Subtype_Indication =>
3765 New_Reference_To (Str_Type, Loc)))),
3766
3767 Variant_Part => Empty))));
3768
3769 Insert_Actions (E, List_Def);
3770 return Equiv_Type;
3771 end Make_CW_Equivalent_Type;
3772
3773 ------------------------
3774 -- Make_Literal_Range --
3775 ------------------------
3776
3777 function Make_Literal_Range
3778 (Loc : Source_Ptr;
3779 Literal_Typ : Entity_Id) return Node_Id
3780 is
3781 Lo : constant Node_Id :=
3782 New_Copy_Tree (String_Literal_Low_Bound (Literal_Typ));
3783
3784 begin
3785 Set_Analyzed (Lo, False);
3786
3787 return
3788 Make_Range (Loc,
3789 Low_Bound => Lo,
3790
3791 High_Bound =>
3792 Make_Op_Subtract (Loc,
3793 Left_Opnd =>
3794 Make_Op_Add (Loc,
3795 Left_Opnd => New_Copy_Tree (Lo),
3796 Right_Opnd =>
3797 Make_Integer_Literal (Loc,
3798 String_Literal_Length (Literal_Typ))),
3799 Right_Opnd => Make_Integer_Literal (Loc, 1)));
3800 end Make_Literal_Range;
3801
3802 ----------------------------
3803 -- Make_Subtype_From_Expr --
3804 ----------------------------
3805
3806 -- 1. If Expr is an uncontrained array expression, creates
3807 -- Unc_Type(Expr'first(1)..Expr'Last(1),..., Expr'first(n)..Expr'last(n))
3808
3809 -- 2. If Expr is a unconstrained discriminated type expression, creates
3810 -- Unc_Type(Expr.Discr1, ... , Expr.Discr_n)
3811
3812 -- 3. If Expr is class-wide, creates an implicit class wide subtype
3813
3814 function Make_Subtype_From_Expr
3815 (E : Node_Id;
3816 Unc_Typ : Entity_Id) return Node_Id
3817 is
3818 Loc : constant Source_Ptr := Sloc (E);
3819 List_Constr : constant List_Id := New_List;
3820 D : Entity_Id;
3821
3822 Full_Subtyp : Entity_Id;
3823 Priv_Subtyp : Entity_Id;
3824 Utyp : Entity_Id;
3825 Full_Exp : Node_Id;
3826
3827 begin
3828 if Is_Private_Type (Unc_Typ)
3829 and then Has_Unknown_Discriminants (Unc_Typ)
3830 then
3831 -- Prepare the subtype completion, Go to base type to
3832 -- find underlying type, because the type may be a generic
3833 -- actual or an explicit subtype.
3834
3835 Utyp := Underlying_Type (Base_Type (Unc_Typ));
3836 Full_Subtyp := Make_Defining_Identifier (Loc,
3837 New_Internal_Name ('C'));
3838 Full_Exp :=
3839 Unchecked_Convert_To
3840 (Utyp, Duplicate_Subexpr_No_Checks (E));
3841 Set_Parent (Full_Exp, Parent (E));
3842
3843 Priv_Subtyp :=
3844 Make_Defining_Identifier (Loc, New_Internal_Name ('P'));
3845
3846 Insert_Action (E,
3847 Make_Subtype_Declaration (Loc,
3848 Defining_Identifier => Full_Subtyp,
3849 Subtype_Indication => Make_Subtype_From_Expr (Full_Exp, Utyp)));
3850
3851 -- Define the dummy private subtype
3852
3853 Set_Ekind (Priv_Subtyp, Subtype_Kind (Ekind (Unc_Typ)));
3854 Set_Etype (Priv_Subtyp, Base_Type (Unc_Typ));
3855 Set_Scope (Priv_Subtyp, Full_Subtyp);
3856 Set_Is_Constrained (Priv_Subtyp);
3857 Set_Is_Tagged_Type (Priv_Subtyp, Is_Tagged_Type (Unc_Typ));
3858 Set_Is_Itype (Priv_Subtyp);
3859 Set_Associated_Node_For_Itype (Priv_Subtyp, E);
3860
3861 if Is_Tagged_Type (Priv_Subtyp) then
3862 Set_Class_Wide_Type
3863 (Base_Type (Priv_Subtyp), Class_Wide_Type (Unc_Typ));
3864 Set_Primitive_Operations (Priv_Subtyp,
3865 Primitive_Operations (Unc_Typ));
3866 end if;
3867
3868 Set_Full_View (Priv_Subtyp, Full_Subtyp);
3869
3870 return New_Reference_To (Priv_Subtyp, Loc);
3871
3872 elsif Is_Array_Type (Unc_Typ) then
3873 for J in 1 .. Number_Dimensions (Unc_Typ) loop
3874 Append_To (List_Constr,
3875 Make_Range (Loc,
3876 Low_Bound =>
3877 Make_Attribute_Reference (Loc,
3878 Prefix => Duplicate_Subexpr_No_Checks (E),
3879 Attribute_Name => Name_First,
3880 Expressions => New_List (
3881 Make_Integer_Literal (Loc, J))),
3882
3883 High_Bound =>
3884 Make_Attribute_Reference (Loc,
3885 Prefix => Duplicate_Subexpr_No_Checks (E),
3886 Attribute_Name => Name_Last,
3887 Expressions => New_List (
3888 Make_Integer_Literal (Loc, J)))));
3889 end loop;
3890
3891 elsif Is_Class_Wide_Type (Unc_Typ) then
3892 declare
3893 CW_Subtype : Entity_Id;
3894 EQ_Typ : Entity_Id := Empty;
3895
3896 begin
3897 -- A class-wide equivalent type is not needed when Java_VM
3898 -- because the JVM back end handles the class-wide object
3899 -- initialization itself (and doesn't need or want the
3900 -- additional intermediate type to handle the assignment).
3901
3902 if Expander_Active and then not Java_VM then
3903 EQ_Typ := Make_CW_Equivalent_Type (Unc_Typ, E);
3904 end if;
3905
3906 CW_Subtype := New_Class_Wide_Subtype (Unc_Typ, E);
3907 Set_Equivalent_Type (CW_Subtype, EQ_Typ);
3908
3909 if Present (EQ_Typ) then
3910 Set_Is_Class_Wide_Equivalent_Type (EQ_Typ);
3911 end if;
3912
3913 Set_Cloned_Subtype (CW_Subtype, Base_Type (Unc_Typ));
3914
3915 return New_Occurrence_Of (CW_Subtype, Loc);
3916 end;
3917
3918 -- Indefinite record type with discriminants
3919
3920 else
3921 D := First_Discriminant (Unc_Typ);
3922 while Present (D) loop
3923 Append_To (List_Constr,
3924 Make_Selected_Component (Loc,
3925 Prefix => Duplicate_Subexpr_No_Checks (E),
3926 Selector_Name => New_Reference_To (D, Loc)));
3927
3928 Next_Discriminant (D);
3929 end loop;
3930 end if;
3931
3932 return
3933 Make_Subtype_Indication (Loc,
3934 Subtype_Mark => New_Reference_To (Unc_Typ, Loc),
3935 Constraint =>
3936 Make_Index_Or_Discriminant_Constraint (Loc,
3937 Constraints => List_Constr));
3938 end Make_Subtype_From_Expr;
3939
3940 -----------------------------
3941 -- May_Generate_Large_Temp --
3942 -----------------------------
3943
3944 -- At the current time, the only types that we return False for (i.e.
3945 -- where we decide we know they cannot generate large temps) are ones
3946 -- where we know the size is 256 bits or less at compile time, and we
3947 -- are still not doing a thorough job on arrays and records ???
3948
3949 function May_Generate_Large_Temp (Typ : Entity_Id) return Boolean is
3950 begin
3951 if not Size_Known_At_Compile_Time (Typ) then
3952 return False;
3953
3954 elsif Esize (Typ) /= 0 and then Esize (Typ) <= 256 then
3955 return False;
3956
3957 elsif Is_Array_Type (Typ)
3958 and then Present (Packed_Array_Type (Typ))
3959 then
3960 return May_Generate_Large_Temp (Packed_Array_Type (Typ));
3961
3962 -- We could do more here to find other small types ???
3963
3964 else
3965 return True;
3966 end if;
3967 end May_Generate_Large_Temp;
3968
3969 ----------------------------
3970 -- New_Class_Wide_Subtype --
3971 ----------------------------
3972
3973 function New_Class_Wide_Subtype
3974 (CW_Typ : Entity_Id;
3975 N : Node_Id) return Entity_Id
3976 is
3977 Res : constant Entity_Id := Create_Itype (E_Void, N);
3978 Res_Name : constant Name_Id := Chars (Res);
3979 Res_Scope : constant Entity_Id := Scope (Res);
3980
3981 begin
3982 Copy_Node (CW_Typ, Res);
3983 Set_Comes_From_Source (Res, False);
3984 Set_Sloc (Res, Sloc (N));
3985 Set_Is_Itype (Res);
3986 Set_Associated_Node_For_Itype (Res, N);
3987 Set_Is_Public (Res, False); -- By default, may be changed below.
3988 Set_Public_Status (Res);
3989 Set_Chars (Res, Res_Name);
3990 Set_Scope (Res, Res_Scope);
3991 Set_Ekind (Res, E_Class_Wide_Subtype);
3992 Set_Next_Entity (Res, Empty);
3993 Set_Etype (Res, Base_Type (CW_Typ));
3994
3995 -- For targets where front-end layout is required, reset the Is_Frozen
3996 -- status of the subtype to False (it can be implicitly set to true
3997 -- from the copy of the class-wide type). For other targets, Gigi
3998 -- doesn't want the class-wide subtype to go through the freezing
3999 -- process (though it's unclear why that causes problems and it would
4000 -- be nice to allow freezing to occur normally for all targets ???).
4001
4002 if Frontend_Layout_On_Target then
4003 Set_Is_Frozen (Res, False);
4004 end if;
4005
4006 Set_Freeze_Node (Res, Empty);
4007 return (Res);
4008 end New_Class_Wide_Subtype;
4009
4010 -----------------------------------
4011 -- OK_To_Do_Constant_Replacement --
4012 -----------------------------------
4013
4014 function OK_To_Do_Constant_Replacement (E : Entity_Id) return Boolean is
4015 ES : constant Entity_Id := Scope (E);
4016 CS : Entity_Id;
4017
4018 begin
4019 -- Do not replace statically allocated objects, because they may be
4020 -- modified outside the current scope.
4021
4022 if Is_Statically_Allocated (E) then
4023 return False;
4024
4025 -- Do not replace aliased or volatile objects, since we don't know what
4026 -- else might change the value.
4027
4028 elsif Is_Aliased (E) or else Treat_As_Volatile (E) then
4029 return False;
4030
4031 -- Debug flag -gnatdM disconnects this optimization
4032
4033 elsif Debug_Flag_MM then
4034 return False;
4035
4036 -- Otherwise check scopes
4037
4038 else
4039 CS := Current_Scope;
4040
4041 loop
4042 -- If we are in right scope, replacement is safe
4043
4044 if CS = ES then
4045 return True;
4046
4047 -- Packages do not affect the determination of safety
4048
4049 elsif Ekind (CS) = E_Package then
4050 exit when CS = Standard_Standard;
4051 CS := Scope (CS);
4052
4053 -- Blocks do not affect the determination of safety
4054
4055 elsif Ekind (CS) = E_Block then
4056 CS := Scope (CS);
4057
4058 -- Loops do not affect the determination of safety. Note that we
4059 -- kill all current values on entry to a loop, so we are just
4060 -- talking about processing within a loop here.
4061
4062 elsif Ekind (CS) = E_Loop then
4063 CS := Scope (CS);
4064
4065 -- Otherwise, the reference is dubious, and we cannot be sure that
4066 -- it is safe to do the replacement.
4067
4068 else
4069 exit;
4070 end if;
4071 end loop;
4072
4073 return False;
4074 end if;
4075 end OK_To_Do_Constant_Replacement;
4076
4077 -------------------------
4078 -- Remove_Side_Effects --
4079 -------------------------
4080
4081 procedure Remove_Side_Effects
4082 (Exp : Node_Id;
4083 Name_Req : Boolean := False;
4084 Variable_Ref : Boolean := False)
4085 is
4086 Loc : constant Source_Ptr := Sloc (Exp);
4087 Exp_Type : constant Entity_Id := Etype (Exp);
4088 Svg_Suppress : constant Suppress_Array := Scope_Suppress;
4089 Def_Id : Entity_Id;
4090 Ref_Type : Entity_Id;
4091 Res : Node_Id;
4092 Ptr_Typ_Decl : Node_Id;
4093 New_Exp : Node_Id;
4094 E : Node_Id;
4095
4096 function Side_Effect_Free (N : Node_Id) return Boolean;
4097 -- Determines if the tree N represents an expression that is known not
4098 -- to have side effects, and for which no processing is required.
4099
4100 function Side_Effect_Free (L : List_Id) return Boolean;
4101 -- Determines if all elements of the list L are side effect free
4102
4103 function Safe_Prefixed_Reference (N : Node_Id) return Boolean;
4104 -- The argument N is a construct where the Prefix is dereferenced if it
4105 -- is an access type and the result is a variable. The call returns True
4106 -- if the construct is side effect free (not considering side effects in
4107 -- other than the prefix which are to be tested by the caller).
4108
4109 function Within_In_Parameter (N : Node_Id) return Boolean;
4110 -- Determines if N is a subcomponent of a composite in-parameter. If so,
4111 -- N is not side-effect free when the actual is global and modifiable
4112 -- indirectly from within a subprogram, because it may be passed by
4113 -- reference. The front-end must be conservative here and assume that
4114 -- this may happen with any array or record type. On the other hand, we
4115 -- cannot create temporaries for all expressions for which this
4116 -- condition is true, for various reasons that might require clearing up
4117 -- ??? For example, descriminant references that appear out of place, or
4118 -- spurious type errors with class-wide expressions. As a result, we
4119 -- limit the transformation to loop bounds, which is so far the only
4120 -- case that requires it.
4121
4122 -----------------------------
4123 -- Safe_Prefixed_Reference --
4124 -----------------------------
4125
4126 function Safe_Prefixed_Reference (N : Node_Id) return Boolean is
4127 begin
4128 -- If prefix is not side effect free, definitely not safe
4129
4130 if not Side_Effect_Free (Prefix (N)) then
4131 return False;
4132
4133 -- If the prefix is of an access type that is not access-to-constant,
4134 -- then this construct is a variable reference, which means it is to
4135 -- be considered to have side effects if Variable_Ref is set True
4136 -- Exception is an access to an entity that is a constant or an
4137 -- in-parameter which does not come from source, and is the result
4138 -- of a previous removal of side-effects.
4139
4140 elsif Is_Access_Type (Etype (Prefix (N)))
4141 and then not Is_Access_Constant (Etype (Prefix (N)))
4142 and then Variable_Ref
4143 then
4144 if not Is_Entity_Name (Prefix (N)) then
4145 return False;
4146 else
4147 return Ekind (Entity (Prefix (N))) = E_Constant
4148 or else Ekind (Entity (Prefix (N))) = E_In_Parameter;
4149 end if;
4150
4151 -- The following test is the simplest way of solving a complex
4152 -- problem uncovered by BB08-010: Side effect on loop bound that
4153 -- is a subcomponent of a global variable:
4154 -- If a loop bound is a subcomponent of a global variable, a
4155 -- modification of that variable within the loop may incorrectly
4156 -- affect the execution of the loop.
4157
4158 elsif not
4159 (Nkind (Parent (Parent (N))) /= N_Loop_Parameter_Specification
4160 or else not Within_In_Parameter (Prefix (N)))
4161 then
4162 return False;
4163
4164 -- All other cases are side effect free
4165
4166 else
4167 return True;
4168 end if;
4169 end Safe_Prefixed_Reference;
4170
4171 ----------------------
4172 -- Side_Effect_Free --
4173 ----------------------
4174
4175 function Side_Effect_Free (N : Node_Id) return Boolean is
4176 begin
4177 -- Note on checks that could raise Constraint_Error. Strictly, if
4178 -- we take advantage of 11.6, these checks do not count as side
4179 -- effects. However, we would just as soon consider that they are
4180 -- side effects, since the backend CSE does not work very well on
4181 -- expressions which can raise Constraint_Error. On the other
4182 -- hand, if we do not consider them to be side effect free, then
4183 -- we get some awkward expansions in -gnato mode, resulting in
4184 -- code insertions at a point where we do not have a clear model
4185 -- for performing the insertions. See 4908-002/comment for details.
4186
4187 -- Special handling for entity names
4188
4189 if Is_Entity_Name (N) then
4190
4191 -- If the entity is a constant, it is definitely side effect
4192 -- free. Note that the test of Is_Variable (N) below might
4193 -- be expected to catch this case, but it does not, because
4194 -- this test goes to the original tree, and we may have
4195 -- already rewritten a variable node with a constant as
4196 -- a result of an earlier Force_Evaluation call.
4197
4198 if Ekind (Entity (N)) = E_Constant
4199 or else Ekind (Entity (N)) = E_In_Parameter
4200 then
4201 return True;
4202
4203 -- Functions are not side effect free
4204
4205 elsif Ekind (Entity (N)) = E_Function then
4206 return False;
4207
4208 -- Variables are considered to be a side effect if Variable_Ref
4209 -- is set or if we have a volatile variable and Name_Req is off.
4210 -- If Name_Req is True then we can't help returning a name which
4211 -- effectively allows multiple references in any case.
4212
4213 elsif Is_Variable (N) then
4214 return not Variable_Ref
4215 and then (not Treat_As_Volatile (Entity (N))
4216 or else Name_Req);
4217
4218 -- Any other entity (e.g. a subtype name) is definitely side
4219 -- effect free.
4220
4221 else
4222 return True;
4223 end if;
4224
4225 -- A value known at compile time is always side effect free
4226
4227 elsif Compile_Time_Known_Value (N) then
4228 return True;
4229 end if;
4230
4231 -- For other than entity names and compile time known values,
4232 -- check the node kind for special processing.
4233
4234 case Nkind (N) is
4235
4236 -- An attribute reference is side effect free if its expressions
4237 -- are side effect free and its prefix is side effect free or
4238 -- is an entity reference.
4239
4240 -- Is this right? what about x'first where x is a variable???
4241
4242 when N_Attribute_Reference =>
4243 return Side_Effect_Free (Expressions (N))
4244 and then Attribute_Name (N) /= Name_Input
4245 and then (Is_Entity_Name (Prefix (N))
4246 or else Side_Effect_Free (Prefix (N)));
4247
4248 -- A binary operator is side effect free if and both operands
4249 -- are side effect free. For this purpose binary operators
4250 -- include membership tests and short circuit forms
4251
4252 when N_Binary_Op |
4253 N_Membership_Test |
4254 N_And_Then |
4255 N_Or_Else =>
4256 return Side_Effect_Free (Left_Opnd (N))
4257 and then Side_Effect_Free (Right_Opnd (N));
4258
4259 -- An explicit dereference is side effect free only if it is
4260 -- a side effect free prefixed reference.
4261
4262 when N_Explicit_Dereference =>
4263 return Safe_Prefixed_Reference (N);
4264
4265 -- A call to _rep_to_pos is side effect free, since we generate
4266 -- this pure function call ourselves. Moreover it is critically
4267 -- important to make this exception, since otherwise we can
4268 -- have discriminants in array components which don't look
4269 -- side effect free in the case of an array whose index type
4270 -- is an enumeration type with an enumeration rep clause.
4271
4272 -- All other function calls are not side effect free
4273
4274 when N_Function_Call =>
4275 return Nkind (Name (N)) = N_Identifier
4276 and then Is_TSS (Name (N), TSS_Rep_To_Pos)
4277 and then
4278 Side_Effect_Free (First (Parameter_Associations (N)));
4279
4280 -- An indexed component is side effect free if it is a side
4281 -- effect free prefixed reference and all the indexing
4282 -- expressions are side effect free.
4283
4284 when N_Indexed_Component =>
4285 return Side_Effect_Free (Expressions (N))
4286 and then Safe_Prefixed_Reference (N);
4287
4288 -- A type qualification is side effect free if the expression
4289 -- is side effect free.
4290
4291 when N_Qualified_Expression =>
4292 return Side_Effect_Free (Expression (N));
4293
4294 -- A selected component is side effect free only if it is a
4295 -- side effect free prefixed reference.
4296
4297 when N_Selected_Component =>
4298 return Safe_Prefixed_Reference (N);
4299
4300 -- A range is side effect free if the bounds are side effect free
4301
4302 when N_Range =>
4303 return Side_Effect_Free (Low_Bound (N))
4304 and then Side_Effect_Free (High_Bound (N));
4305
4306 -- A slice is side effect free if it is a side effect free
4307 -- prefixed reference and the bounds are side effect free.
4308
4309 when N_Slice =>
4310 return Side_Effect_Free (Discrete_Range (N))
4311 and then Safe_Prefixed_Reference (N);
4312
4313 -- A type conversion is side effect free if the expression
4314 -- to be converted is side effect free.
4315
4316 when N_Type_Conversion =>
4317 return Side_Effect_Free (Expression (N));
4318
4319 -- A unary operator is side effect free if the operand
4320 -- is side effect free.
4321
4322 when N_Unary_Op =>
4323 return Side_Effect_Free (Right_Opnd (N));
4324
4325 -- An unchecked type conversion is side effect free only if it
4326 -- is safe and its argument is side effect free.
4327
4328 when N_Unchecked_Type_Conversion =>
4329 return Safe_Unchecked_Type_Conversion (N)
4330 and then Side_Effect_Free (Expression (N));
4331
4332 -- An unchecked expression is side effect free if its expression
4333 -- is side effect free.
4334
4335 when N_Unchecked_Expression =>
4336 return Side_Effect_Free (Expression (N));
4337
4338 -- A literal is side effect free
4339
4340 when N_Character_Literal |
4341 N_Integer_Literal |
4342 N_Real_Literal |
4343 N_String_Literal =>
4344 return True;
4345
4346 -- We consider that anything else has side effects. This is a bit
4347 -- crude, but we are pretty close for most common cases, and we
4348 -- are certainly correct (i.e. we never return True when the
4349 -- answer should be False).
4350
4351 when others =>
4352 return False;
4353 end case;
4354 end Side_Effect_Free;
4355
4356 -- A list is side effect free if all elements of the list are
4357 -- side effect free.
4358
4359 function Side_Effect_Free (L : List_Id) return Boolean is
4360 N : Node_Id;
4361
4362 begin
4363 if L = No_List or else L = Error_List then
4364 return True;
4365
4366 else
4367 N := First (L);
4368 while Present (N) loop
4369 if not Side_Effect_Free (N) then
4370 return False;
4371 else
4372 Next (N);
4373 end if;
4374 end loop;
4375
4376 return True;
4377 end if;
4378 end Side_Effect_Free;
4379
4380 -------------------------
4381 -- Within_In_Parameter --
4382 -------------------------
4383
4384 function Within_In_Parameter (N : Node_Id) return Boolean is
4385 begin
4386 if not Comes_From_Source (N) then
4387 return False;
4388
4389 elsif Is_Entity_Name (N) then
4390 return
4391 Ekind (Entity (N)) = E_In_Parameter;
4392
4393 elsif Nkind (N) = N_Indexed_Component
4394 or else Nkind (N) = N_Selected_Component
4395 then
4396 return Within_In_Parameter (Prefix (N));
4397 else
4398
4399 return False;
4400 end if;
4401 end Within_In_Parameter;
4402
4403 -- Start of processing for Remove_Side_Effects
4404
4405 begin
4406 -- If we are side effect free already or expansion is disabled,
4407 -- there is nothing to do.
4408
4409 if Side_Effect_Free (Exp) or else not Expander_Active then
4410 return;
4411 end if;
4412
4413 -- All this must not have any checks
4414
4415 Scope_Suppress := (others => True);
4416
4417 -- If it is a scalar type and we need to capture the value, just
4418 -- make a copy. Likewise for a function call. And if we have a
4419 -- volatile variable and Nam_Req is not set (see comments above
4420 -- for Side_Effect_Free).
4421
4422 if Is_Elementary_Type (Exp_Type)
4423 and then (Variable_Ref
4424 or else Nkind (Exp) = N_Function_Call
4425 or else (not Name_Req
4426 and then Is_Entity_Name (Exp)
4427 and then Treat_As_Volatile (Entity (Exp))))
4428 then
4429
4430 Def_Id := Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
4431 Set_Etype (Def_Id, Exp_Type);
4432 Res := New_Reference_To (Def_Id, Loc);
4433
4434 E :=
4435 Make_Object_Declaration (Loc,
4436 Defining_Identifier => Def_Id,
4437 Object_Definition => New_Reference_To (Exp_Type, Loc),
4438 Constant_Present => True,
4439 Expression => Relocate_Node (Exp));
4440
4441 Set_Assignment_OK (E);
4442 Insert_Action (Exp, E);
4443
4444 -- If the expression has the form v.all then we can just capture
4445 -- the pointer, and then do an explicit dereference on the result.
4446
4447 elsif Nkind (Exp) = N_Explicit_Dereference then
4448 Def_Id :=
4449 Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
4450 Res :=
4451 Make_Explicit_Dereference (Loc, New_Reference_To (Def_Id, Loc));
4452
4453 Insert_Action (Exp,
4454 Make_Object_Declaration (Loc,
4455 Defining_Identifier => Def_Id,
4456 Object_Definition =>
4457 New_Reference_To (Etype (Prefix (Exp)), Loc),
4458 Constant_Present => True,
4459 Expression => Relocate_Node (Prefix (Exp))));
4460
4461 -- Similar processing for an unchecked conversion of an expression
4462 -- of the form v.all, where we want the same kind of treatment.
4463
4464 elsif Nkind (Exp) = N_Unchecked_Type_Conversion
4465 and then Nkind (Expression (Exp)) = N_Explicit_Dereference
4466 then
4467 Remove_Side_Effects (Expression (Exp), Name_Req, Variable_Ref);
4468 Scope_Suppress := Svg_Suppress;
4469 return;
4470
4471 -- If this is a type conversion, leave the type conversion and remove
4472 -- the side effects in the expression. This is important in several
4473 -- circumstances: for change of representations, and also when this
4474 -- is a view conversion to a smaller object, where gigi can end up
4475 -- creating its own temporary of the wrong size.
4476
4477 elsif Nkind (Exp) = N_Type_Conversion then
4478 Remove_Side_Effects (Expression (Exp), Name_Req, Variable_Ref);
4479 Scope_Suppress := Svg_Suppress;
4480 return;
4481
4482 -- If this is an unchecked conversion that Gigi can't handle, make
4483 -- a copy or a use a renaming to capture the value.
4484
4485 elsif Nkind (Exp) = N_Unchecked_Type_Conversion
4486 and then not Safe_Unchecked_Type_Conversion (Exp)
4487 then
4488 if Controlled_Type (Exp_Type) then
4489
4490 -- Use a renaming to capture the expression, rather than create
4491 -- a controlled temporary.
4492
4493 Def_Id := Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
4494 Res := New_Reference_To (Def_Id, Loc);
4495
4496 Insert_Action (Exp,
4497 Make_Object_Renaming_Declaration (Loc,
4498 Defining_Identifier => Def_Id,
4499 Subtype_Mark => New_Reference_To (Exp_Type, Loc),
4500 Name => Relocate_Node (Exp)));
4501
4502 else
4503 Def_Id := Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
4504 Set_Etype (Def_Id, Exp_Type);
4505 Res := New_Reference_To (Def_Id, Loc);
4506
4507 E :=
4508 Make_Object_Declaration (Loc,
4509 Defining_Identifier => Def_Id,
4510 Object_Definition => New_Reference_To (Exp_Type, Loc),
4511 Constant_Present => not Is_Variable (Exp),
4512 Expression => Relocate_Node (Exp));
4513
4514 Set_Assignment_OK (E);
4515 Insert_Action (Exp, E);
4516 end if;
4517
4518 -- For expressions that denote objects, we can use a renaming scheme.
4519 -- We skip using this if we have a volatile variable and we do not
4520 -- have Nam_Req set true (see comments above for Side_Effect_Free).
4521
4522 elsif Is_Object_Reference (Exp)
4523 and then Nkind (Exp) /= N_Function_Call
4524 and then (Name_Req
4525 or else not Is_Entity_Name (Exp)
4526 or else not Treat_As_Volatile (Entity (Exp)))
4527 then
4528 Def_Id := Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
4529
4530 if Nkind (Exp) = N_Selected_Component
4531 and then Nkind (Prefix (Exp)) = N_Function_Call
4532 and then Is_Array_Type (Exp_Type)
4533 then
4534 -- Avoid generating a variable-sized temporary, by generating
4535 -- the renaming declaration just for the function call. The
4536 -- transformation could be refined to apply only when the array
4537 -- component is constrained by a discriminant???
4538
4539 Res :=
4540 Make_Selected_Component (Loc,
4541 Prefix => New_Occurrence_Of (Def_Id, Loc),
4542 Selector_Name => Selector_Name (Exp));
4543
4544 Insert_Action (Exp,
4545 Make_Object_Renaming_Declaration (Loc,
4546 Defining_Identifier => Def_Id,
4547 Subtype_Mark =>
4548 New_Reference_To (Base_Type (Etype (Prefix (Exp))), Loc),
4549 Name => Relocate_Node (Prefix (Exp))));
4550
4551 else
4552 Res := New_Reference_To (Def_Id, Loc);
4553
4554 Insert_Action (Exp,
4555 Make_Object_Renaming_Declaration (Loc,
4556 Defining_Identifier => Def_Id,
4557 Subtype_Mark => New_Reference_To (Exp_Type, Loc),
4558 Name => Relocate_Node (Exp)));
4559
4560 end if;
4561
4562 -- If this is a packed reference, or a selected component with a
4563 -- non-standard representation, a reference to the temporary will
4564 -- be replaced by a copy of the original expression (see
4565 -- exp_ch2.Expand_Renaming). Otherwise the temporary must be
4566 -- elaborated by gigi, and is of course not to be replaced in-line
4567 -- by the expression it renames, which would defeat the purpose of
4568 -- removing the side-effect.
4569
4570 if (Nkind (Exp) = N_Selected_Component
4571 or else Nkind (Exp) = N_Indexed_Component)
4572 and then Has_Non_Standard_Rep (Etype (Prefix (Exp)))
4573 then
4574 null;
4575 else
4576 Set_Is_Renaming_Of_Object (Def_Id, False);
4577 end if;
4578
4579 -- Otherwise we generate a reference to the value
4580
4581 else
4582 Ref_Type := Make_Defining_Identifier (Loc, New_Internal_Name ('A'));
4583
4584 Ptr_Typ_Decl :=
4585 Make_Full_Type_Declaration (Loc,
4586 Defining_Identifier => Ref_Type,
4587 Type_Definition =>
4588 Make_Access_To_Object_Definition (Loc,
4589 All_Present => True,
4590 Subtype_Indication =>
4591 New_Reference_To (Exp_Type, Loc)));
4592
4593 E := Exp;
4594 Insert_Action (Exp, Ptr_Typ_Decl);
4595
4596 Def_Id := Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
4597 Set_Etype (Def_Id, Exp_Type);
4598
4599 Res :=
4600 Make_Explicit_Dereference (Loc,
4601 Prefix => New_Reference_To (Def_Id, Loc));
4602
4603 if Nkind (E) = N_Explicit_Dereference then
4604 New_Exp := Relocate_Node (Prefix (E));
4605 else
4606 E := Relocate_Node (E);
4607 New_Exp := Make_Reference (Loc, E);
4608 end if;
4609
4610 if Is_Delayed_Aggregate (E) then
4611
4612 -- The expansion of nested aggregates is delayed until the
4613 -- enclosing aggregate is expanded. As aggregates are often
4614 -- qualified, the predicate applies to qualified expressions
4615 -- as well, indicating that the enclosing aggregate has not
4616 -- been expanded yet. At this point the aggregate is part of
4617 -- a stand-alone declaration, and must be fully expanded.
4618
4619 if Nkind (E) = N_Qualified_Expression then
4620 Set_Expansion_Delayed (Expression (E), False);
4621 Set_Analyzed (Expression (E), False);
4622 else
4623 Set_Expansion_Delayed (E, False);
4624 end if;
4625
4626 Set_Analyzed (E, False);
4627 end if;
4628
4629 Insert_Action (Exp,
4630 Make_Object_Declaration (Loc,
4631 Defining_Identifier => Def_Id,
4632 Object_Definition => New_Reference_To (Ref_Type, Loc),
4633 Expression => New_Exp));
4634 end if;
4635
4636 -- Preserve the Assignment_OK flag in all copies, since at least
4637 -- one copy may be used in a context where this flag must be set
4638 -- (otherwise why would the flag be set in the first place).
4639
4640 Set_Assignment_OK (Res, Assignment_OK (Exp));
4641
4642 -- Finally rewrite the original expression and we are done
4643
4644 Rewrite (Exp, Res);
4645 Analyze_And_Resolve (Exp, Exp_Type);
4646 Scope_Suppress := Svg_Suppress;
4647 end Remove_Side_Effects;
4648
4649 ---------------------------
4650 -- Represented_As_Scalar --
4651 ---------------------------
4652
4653 function Represented_As_Scalar (T : Entity_Id) return Boolean is
4654 UT : constant Entity_Id := Underlying_Type (T);
4655 begin
4656 return Is_Scalar_Type (UT)
4657 or else (Is_Bit_Packed_Array (UT)
4658 and then Is_Scalar_Type (Packed_Array_Type (UT)));
4659 end Represented_As_Scalar;
4660
4661 ------------------------------------
4662 -- Safe_Unchecked_Type_Conversion --
4663 ------------------------------------
4664
4665 -- Note: this function knows quite a bit about the exact requirements
4666 -- of Gigi with respect to unchecked type conversions, and its code
4667 -- must be coordinated with any changes in Gigi in this area.
4668
4669 -- The above requirements should be documented in Sinfo ???
4670
4671 function Safe_Unchecked_Type_Conversion (Exp : Node_Id) return Boolean is
4672 Otyp : Entity_Id;
4673 Ityp : Entity_Id;
4674 Oalign : Uint;
4675 Ialign : Uint;
4676 Pexp : constant Node_Id := Parent (Exp);
4677
4678 begin
4679 -- If the expression is the RHS of an assignment or object declaration
4680 -- we are always OK because there will always be a target.
4681
4682 -- Object renaming declarations, (generated for view conversions of
4683 -- actuals in inlined calls), like object declarations, provide an
4684 -- explicit type, and are safe as well.
4685
4686 if (Nkind (Pexp) = N_Assignment_Statement
4687 and then Expression (Pexp) = Exp)
4688 or else Nkind (Pexp) = N_Object_Declaration
4689 or else Nkind (Pexp) = N_Object_Renaming_Declaration
4690 then
4691 return True;
4692
4693 -- If the expression is the prefix of an N_Selected_Component
4694 -- we should also be OK because GCC knows to look inside the
4695 -- conversion except if the type is discriminated. We assume
4696 -- that we are OK anyway if the type is not set yet or if it is
4697 -- controlled since we can't afford to introduce a temporary in
4698 -- this case.
4699
4700 elsif Nkind (Pexp) = N_Selected_Component
4701 and then Prefix (Pexp) = Exp
4702 then
4703 if No (Etype (Pexp)) then
4704 return True;
4705 else
4706 return
4707 not Has_Discriminants (Etype (Pexp))
4708 or else Is_Constrained (Etype (Pexp));
4709 end if;
4710 end if;
4711
4712 -- Set the output type, this comes from Etype if it is set, otherwise
4713 -- we take it from the subtype mark, which we assume was already
4714 -- fully analyzed.
4715
4716 if Present (Etype (Exp)) then
4717 Otyp := Etype (Exp);
4718 else
4719 Otyp := Entity (Subtype_Mark (Exp));
4720 end if;
4721
4722 -- The input type always comes from the expression, and we assume
4723 -- this is indeed always analyzed, so we can simply get the Etype.
4724
4725 Ityp := Etype (Expression (Exp));
4726
4727 -- Initialize alignments to unknown so far
4728
4729 Oalign := No_Uint;
4730 Ialign := No_Uint;
4731
4732 -- Replace a concurrent type by its corresponding record type
4733 -- and each type by its underlying type and do the tests on those.
4734 -- The original type may be a private type whose completion is a
4735 -- concurrent type, so find the underlying type first.
4736
4737 if Present (Underlying_Type (Otyp)) then
4738 Otyp := Underlying_Type (Otyp);
4739 end if;
4740
4741 if Present (Underlying_Type (Ityp)) then
4742 Ityp := Underlying_Type (Ityp);
4743 end if;
4744
4745 if Is_Concurrent_Type (Otyp) then
4746 Otyp := Corresponding_Record_Type (Otyp);
4747 end if;
4748
4749 if Is_Concurrent_Type (Ityp) then
4750 Ityp := Corresponding_Record_Type (Ityp);
4751 end if;
4752
4753 -- If the base types are the same, we know there is no problem since
4754 -- this conversion will be a noop.
4755
4756 if Implementation_Base_Type (Otyp) = Implementation_Base_Type (Ityp) then
4757 return True;
4758
4759 -- Same if this is an upwards conversion of an untagged type, and there
4760 -- are no constraints involved (could be more general???)
4761
4762 elsif Etype (Ityp) = Otyp
4763 and then not Is_Tagged_Type (Ityp)
4764 and then not Has_Discriminants (Ityp)
4765 and then No (First_Rep_Item (Base_Type (Ityp)))
4766 then
4767 return True;
4768
4769 -- If the size of output type is known at compile time, there is
4770 -- never a problem. Note that unconstrained records are considered
4771 -- to be of known size, but we can't consider them that way here,
4772 -- because we are talking about the actual size of the object.
4773
4774 -- We also make sure that in addition to the size being known, we do
4775 -- not have a case which might generate an embarrassingly large temp
4776 -- in stack checking mode.
4777
4778 elsif Size_Known_At_Compile_Time (Otyp)
4779 and then
4780 (not Stack_Checking_Enabled
4781 or else not May_Generate_Large_Temp (Otyp))
4782 and then not (Is_Record_Type (Otyp) and then not Is_Constrained (Otyp))
4783 then
4784 return True;
4785
4786 -- If either type is tagged, then we know the alignment is OK so
4787 -- Gigi will be able to use pointer punning.
4788
4789 elsif Is_Tagged_Type (Otyp) or else Is_Tagged_Type (Ityp) then
4790 return True;
4791
4792 -- If either type is a limited record type, we cannot do a copy, so
4793 -- say safe since there's nothing else we can do.
4794
4795 elsif Is_Limited_Record (Otyp) or else Is_Limited_Record (Ityp) then
4796 return True;
4797
4798 -- Conversions to and from packed array types are always ignored and
4799 -- hence are safe.
4800
4801 elsif Is_Packed_Array_Type (Otyp)
4802 or else Is_Packed_Array_Type (Ityp)
4803 then
4804 return True;
4805 end if;
4806
4807 -- The only other cases known to be safe is if the input type's
4808 -- alignment is known to be at least the maximum alignment for the
4809 -- target or if both alignments are known and the output type's
4810 -- alignment is no stricter than the input's. We can use the alignment
4811 -- of the component type of an array if a type is an unpacked
4812 -- array type.
4813
4814 if Present (Alignment_Clause (Otyp)) then
4815 Oalign := Expr_Value (Expression (Alignment_Clause (Otyp)));
4816
4817 elsif Is_Array_Type (Otyp)
4818 and then Present (Alignment_Clause (Component_Type (Otyp)))
4819 then
4820 Oalign := Expr_Value (Expression (Alignment_Clause
4821 (Component_Type (Otyp))));
4822 end if;
4823
4824 if Present (Alignment_Clause (Ityp)) then
4825 Ialign := Expr_Value (Expression (Alignment_Clause (Ityp)));
4826
4827 elsif Is_Array_Type (Ityp)
4828 and then Present (Alignment_Clause (Component_Type (Ityp)))
4829 then
4830 Ialign := Expr_Value (Expression (Alignment_Clause
4831 (Component_Type (Ityp))));
4832 end if;
4833
4834 if Ialign /= No_Uint and then Ialign > Maximum_Alignment then
4835 return True;
4836
4837 elsif Ialign /= No_Uint and then Oalign /= No_Uint
4838 and then Ialign <= Oalign
4839 then
4840 return True;
4841
4842 -- Otherwise, Gigi cannot handle this and we must make a temporary
4843
4844 else
4845 return False;
4846 end if;
4847 end Safe_Unchecked_Type_Conversion;
4848
4849 ---------------------------------
4850 -- Set_Current_Value_Condition --
4851 ---------------------------------
4852
4853 -- Note: the implementation of this procedure is very closely tied to the
4854 -- implementation of Get_Current_Value_Condition. Here we set required
4855 -- Current_Value fields, and in Get_Current_Value_Condition, we interpret
4856 -- them, so they must have a consistent view.
4857
4858 procedure Set_Current_Value_Condition (Cnode : Node_Id) is
4859
4860 procedure Set_Entity_Current_Value (N : Node_Id);
4861 -- If N is an entity reference, where the entity is of an appropriate
4862 -- kind, then set the current value of this entity to Cnode, unless
4863 -- there is already a definite value set there.
4864
4865 procedure Set_Expression_Current_Value (N : Node_Id);
4866 -- If N is of an appropriate form, sets an appropriate entry in current
4867 -- value fields of relevant entities. Multiple entities can be affected
4868 -- in the case of an AND or AND THEN.
4869
4870 ------------------------------
4871 -- Set_Entity_Current_Value --
4872 ------------------------------
4873
4874 procedure Set_Entity_Current_Value (N : Node_Id) is
4875 begin
4876 if Is_Entity_Name (N) then
4877 declare
4878 Ent : constant Entity_Id := Entity (N);
4879
4880 begin
4881 -- Don't capture if not safe to do so
4882
4883 if not Safe_To_Capture_Value (N, Ent, Cond => True) then
4884 return;
4885 end if;
4886
4887 -- Here we have a case where the Current_Value field may
4888 -- need to be set. We set it if it is not already set to a
4889 -- compile time expression value.
4890
4891 -- Note that this represents a decision that one condition
4892 -- blots out another previous one. That's certainly right
4893 -- if they occur at the same level. If the second one is
4894 -- nested, then the decision is neither right nor wrong (it
4895 -- would be equally OK to leave the outer one in place, or
4896 -- take the new inner one. Really we should record both, but
4897 -- our data structures are not that elaborate.
4898
4899 if Nkind (Current_Value (Ent)) not in N_Subexpr then
4900 Set_Current_Value (Ent, Cnode);
4901 end if;
4902 end;
4903 end if;
4904 end Set_Entity_Current_Value;
4905
4906 ----------------------------------
4907 -- Set_Expression_Current_Value --
4908 ----------------------------------
4909
4910 procedure Set_Expression_Current_Value (N : Node_Id) is
4911 Cond : Node_Id;
4912
4913 begin
4914 Cond := N;
4915
4916 -- Loop to deal with (ignore for now) any NOT operators present. The
4917 -- presence of NOT operators will be handled properly when we call
4918 -- Get_Current_Value_Condition.
4919
4920 while Nkind (Cond) = N_Op_Not loop
4921 Cond := Right_Opnd (Cond);
4922 end loop;
4923
4924 -- For an AND or AND THEN, recursively process operands
4925
4926 if Nkind (Cond) = N_Op_And or else Nkind (Cond) = N_And_Then then
4927 Set_Expression_Current_Value (Left_Opnd (Cond));
4928 Set_Expression_Current_Value (Right_Opnd (Cond));
4929 return;
4930 end if;
4931
4932 -- Check possible relational operator
4933
4934 if Nkind (Cond) in N_Op_Compare then
4935 if Compile_Time_Known_Value (Right_Opnd (Cond)) then
4936 Set_Entity_Current_Value (Left_Opnd (Cond));
4937 elsif Compile_Time_Known_Value (Left_Opnd (Cond)) then
4938 Set_Entity_Current_Value (Right_Opnd (Cond));
4939 end if;
4940
4941 -- Check possible boolean variable reference
4942
4943 else
4944 Set_Entity_Current_Value (Cond);
4945 end if;
4946 end Set_Expression_Current_Value;
4947
4948 -- Start of processing for Set_Current_Value_Condition
4949
4950 begin
4951 Set_Expression_Current_Value (Condition (Cnode));
4952 end Set_Current_Value_Condition;
4953
4954 --------------------------
4955 -- Set_Elaboration_Flag --
4956 --------------------------
4957
4958 procedure Set_Elaboration_Flag (N : Node_Id; Spec_Id : Entity_Id) is
4959 Loc : constant Source_Ptr := Sloc (N);
4960 Ent : constant Entity_Id := Elaboration_Entity (Spec_Id);
4961 Asn : Node_Id;
4962
4963 begin
4964 if Present (Ent) then
4965
4966 -- Nothing to do if at the compilation unit level, because in this
4967 -- case the flag is set by the binder generated elaboration routine.
4968
4969 if Nkind (Parent (N)) = N_Compilation_Unit then
4970 null;
4971
4972 -- Here we do need to generate an assignment statement
4973
4974 else
4975 Check_Restriction (No_Elaboration_Code, N);
4976 Asn :=
4977 Make_Assignment_Statement (Loc,
4978 Name => New_Occurrence_Of (Ent, Loc),
4979 Expression => New_Occurrence_Of (Standard_True, Loc));
4980
4981 if Nkind (Parent (N)) = N_Subunit then
4982 Insert_After (Corresponding_Stub (Parent (N)), Asn);
4983 else
4984 Insert_After (N, Asn);
4985 end if;
4986
4987 Analyze (Asn);
4988
4989 -- Kill current value indication. This is necessary because
4990 -- the tests of this flag are inserted out of sequence and must
4991 -- not pick up bogus indications of the wrong constant value.
4992
4993 Set_Current_Value (Ent, Empty);
4994 end if;
4995 end if;
4996 end Set_Elaboration_Flag;
4997
4998 ----------------------------
4999 -- Set_Renamed_Subprogram --
5000 ----------------------------
5001
5002 procedure Set_Renamed_Subprogram (N : Node_Id; E : Entity_Id) is
5003 begin
5004 -- If input node is an identifier, we can just reset it
5005
5006 if Nkind (N) = N_Identifier then
5007 Set_Chars (N, Chars (E));
5008 Set_Entity (N, E);
5009
5010 -- Otherwise we have to do a rewrite, preserving Comes_From_Source
5011
5012 else
5013 declare
5014 CS : constant Boolean := Comes_From_Source (N);
5015 begin
5016 Rewrite (N, Make_Identifier (Sloc (N), Chars => Chars (E)));
5017 Set_Entity (N, E);
5018 Set_Comes_From_Source (N, CS);
5019 Set_Analyzed (N, True);
5020 end;
5021 end if;
5022 end Set_Renamed_Subprogram;
5023
5024 --------------------------
5025 -- Target_Has_Fixed_Ops --
5026 --------------------------
5027
5028 Integer_Sized_Small : Ureal;
5029 -- Set to 2.0 ** -(Integer'Size - 1) the first time that this
5030 -- function is called (we don't want to compute it more than once!)
5031
5032 Long_Integer_Sized_Small : Ureal;
5033 -- Set to 2.0 ** -(Long_Integer'Size - 1) the first time that this
5034 -- functoin is called (we don't want to compute it more than once)
5035
5036 First_Time_For_THFO : Boolean := True;
5037 -- Set to False after first call (if Fractional_Fixed_Ops_On_Target)
5038
5039 function Target_Has_Fixed_Ops
5040 (Left_Typ : Entity_Id;
5041 Right_Typ : Entity_Id;
5042 Result_Typ : Entity_Id) return Boolean
5043 is
5044 function Is_Fractional_Type (Typ : Entity_Id) return Boolean;
5045 -- Return True if the given type is a fixed-point type with a small
5046 -- value equal to 2 ** (-(T'Object_Size - 1)) and whose values have
5047 -- an absolute value less than 1.0. This is currently limited
5048 -- to fixed-point types that map to Integer or Long_Integer.
5049
5050 ------------------------
5051 -- Is_Fractional_Type --
5052 ------------------------
5053
5054 function Is_Fractional_Type (Typ : Entity_Id) return Boolean is
5055 begin
5056 if Esize (Typ) = Standard_Integer_Size then
5057 return Small_Value (Typ) = Integer_Sized_Small;
5058
5059 elsif Esize (Typ) = Standard_Long_Integer_Size then
5060 return Small_Value (Typ) = Long_Integer_Sized_Small;
5061
5062 else
5063 return False;
5064 end if;
5065 end Is_Fractional_Type;
5066
5067 -- Start of processing for Target_Has_Fixed_Ops
5068
5069 begin
5070 -- Return False if Fractional_Fixed_Ops_On_Target is false
5071
5072 if not Fractional_Fixed_Ops_On_Target then
5073 return False;
5074 end if;
5075
5076 -- Here the target has Fractional_Fixed_Ops, if first time, compute
5077 -- standard constants used by Is_Fractional_Type.
5078
5079 if First_Time_For_THFO then
5080 First_Time_For_THFO := False;
5081
5082 Integer_Sized_Small :=
5083 UR_From_Components
5084 (Num => Uint_1,
5085 Den => UI_From_Int (Standard_Integer_Size - 1),
5086 Rbase => 2);
5087
5088 Long_Integer_Sized_Small :=
5089 UR_From_Components
5090 (Num => Uint_1,
5091 Den => UI_From_Int (Standard_Long_Integer_Size - 1),
5092 Rbase => 2);
5093 end if;
5094
5095 -- Return True if target supports fixed-by-fixed multiply/divide
5096 -- for fractional fixed-point types (see Is_Fractional_Type) and
5097 -- the operand and result types are equivalent fractional types.
5098
5099 return Is_Fractional_Type (Base_Type (Left_Typ))
5100 and then Is_Fractional_Type (Base_Type (Right_Typ))
5101 and then Is_Fractional_Type (Base_Type (Result_Typ))
5102 and then Esize (Left_Typ) = Esize (Right_Typ)
5103 and then Esize (Left_Typ) = Esize (Result_Typ);
5104 end Target_Has_Fixed_Ops;
5105
5106 ------------------------------------------
5107 -- Type_May_Have_Bit_Aligned_Components --
5108 ------------------------------------------
5109
5110 function Type_May_Have_Bit_Aligned_Components
5111 (Typ : Entity_Id) return Boolean
5112 is
5113 begin
5114 -- Array type, check component type
5115
5116 if Is_Array_Type (Typ) then
5117 return
5118 Type_May_Have_Bit_Aligned_Components (Component_Type (Typ));
5119
5120 -- Record type, check components
5121
5122 elsif Is_Record_Type (Typ) then
5123 declare
5124 E : Entity_Id;
5125
5126 begin
5127 E := First_Entity (Typ);
5128 while Present (E) loop
5129 if Ekind (E) = E_Component
5130 or else Ekind (E) = E_Discriminant
5131 then
5132 if Component_May_Be_Bit_Aligned (E)
5133 or else
5134 Type_May_Have_Bit_Aligned_Components (Etype (E))
5135 then
5136 return True;
5137 end if;
5138 end if;
5139
5140 Next_Entity (E);
5141 end loop;
5142
5143 return False;
5144 end;
5145
5146 -- Type other than array or record is always OK
5147
5148 else
5149 return False;
5150 end if;
5151 end Type_May_Have_Bit_Aligned_Components;
5152
5153 ----------------------------
5154 -- Wrap_Cleanup_Procedure --
5155 ----------------------------
5156
5157 procedure Wrap_Cleanup_Procedure (N : Node_Id) is
5158 Loc : constant Source_Ptr := Sloc (N);
5159 Stseq : constant Node_Id := Handled_Statement_Sequence (N);
5160 Stmts : constant List_Id := Statements (Stseq);
5161
5162 begin
5163 if Abort_Allowed then
5164 Prepend_To (Stmts, Build_Runtime_Call (Loc, RE_Abort_Defer));
5165 Append_To (Stmts, Build_Runtime_Call (Loc, RE_Abort_Undefer));
5166 end if;
5167 end Wrap_Cleanup_Procedure;
5168
5169 end Exp_Util;
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