?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
(extendsfdf2): Add pattern accidentally deleted when cirrus instructions were
[official-gcc.git] / gcc / ada / sem_ch13.adb
blob6eb7b4f79d85b42bd2277e4d44077fbb7b06cfe5
1 ------------------------------------------------------------------------------
2 -- --
3 -- GNAT COMPILER COMPONENTS --
4 -- --
5 -- S E M _ C H 1 3 --
6 -- --
7 -- B o d y --
8 -- --
9 -- --
10 -- Copyright (C) 1992-2002, Free Software Foundation, Inc. --
11 -- --
12 -- GNAT is free software; you can redistribute it and/or modify it under --
13 -- terms of the GNU General Public License as published by the Free Soft- --
14 -- ware Foundation; either version 2, or (at your option) any later ver- --
15 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
16 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
17 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
18 -- for more details. You should have received a copy of the GNU General --
19 -- Public License distributed with GNAT; see file COPYING. If not, write --
20 -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
21 -- MA 02111-1307, USA. --
22 -- --
23 -- GNAT was originally developed by the GNAT team at New York University. --
24 -- Extensive contributions were provided by Ada Core Technologies Inc. --
25 -- --
26 ------------------------------------------------------------------------------
27
28 with Atree; use Atree;
29 with Checks; use Checks;
30 with Einfo; use Einfo;
31 with Errout; use Errout;
32 with Exp_Tss; use Exp_Tss;
33 with Exp_Util; use Exp_Util;
34 with Hostparm; use Hostparm;
35 with Lib; use Lib;
36 with Nlists; use Nlists;
37 with Nmake; use Nmake;
38 with Opt; use Opt;
39 with Rtsfind; use Rtsfind;
40 with Sem; use Sem;
41 with Sem_Ch8; use Sem_Ch8;
42 with Sem_Eval; use Sem_Eval;
43 with Sem_Res; use Sem_Res;
44 with Sem_Type; use Sem_Type;
45 with Sem_Util; use Sem_Util;
46 with Snames; use Snames;
47 with Stand; use Stand;
48 with Sinfo; use Sinfo;
49 with Table;
50 with Ttypes; use Ttypes;
51 with Tbuild; use Tbuild;
52 with Urealp; use Urealp;
53
54 with GNAT.Heap_Sort_A; use GNAT.Heap_Sort_A;
55
56 package body Sem_Ch13 is
57
58 SSU : constant Pos := System_Storage_Unit;
59 -- Convenient short hand for commonly used constant
60
61 -----------------------
62 -- Local Subprograms --
63 -----------------------
64
65 procedure Alignment_Check_For_Esize_Change (Typ : Entity_Id);
66 -- This routine is called after setting the Esize of type entity Typ.
67 -- The purpose is to deal with the situation where an aligment has been
68 -- inherited from a derived type that is no longer appropriate for the
69 -- new Esize value. In this case, we reset the Alignment to unknown.
70
71 procedure Check_Component_Overlap (C1_Ent, C2_Ent : Entity_Id);
72 -- Given two entities for record components or discriminants, checks
73 -- if they hav overlapping component clauses and issues errors if so.
74
75 function Get_Alignment_Value (Expr : Node_Id) return Uint;
76 -- Given the expression for an alignment value, returns the corresponding
77 -- Uint value. If the value is inappropriate, then error messages are
78 -- posted as required, and a value of No_Uint is returned.
79
80 function Is_Operational_Item (N : Node_Id) return Boolean;
81 -- A specification for a stream attribute is allowed before the full
82 -- type is declared, as explained in AI-00137 and the corrigendum.
83 -- Attributes that do not specify a representation characteristic are
84 -- operational attributes.
85
86 procedure New_Stream_Function
87 (N : Node_Id;
88 Ent : Entity_Id;
89 Subp : Entity_Id;
90 Nam : Name_Id);
91 -- Create a function renaming of a given stream attribute to the
92 -- designated subprogram and then in the tagged case, provide this as
93 -- a primitive operation, or in the non-tagged case make an appropriate
94 -- TSS entry. Used for Input. This is more properly an expansion activity
95 -- than just semantics, but the presence of user-defined stream functions
96 -- for limited types is a legality check, which is why this takes place
97 -- here rather than in exp_ch13, where it was previously.
98
99 -- To avoid elaboration anomalies with freeze nodes, for untagged types
100 -- we generate both a subprogram declaration and a subprogram renaming
101 -- declaration, so that the attribute specification is handled as a
102 -- renaming_as_body. For tagged types, the specification is one of the
103 -- primitive specs.
104
105 procedure New_Stream_Procedure
106 (N : Node_Id;
107 Ent : Entity_Id;
108 Subp : Entity_Id;
109 Nam : Name_Id;
110 Out_P : Boolean := False);
111 -- Create a procedure renaming of a given stream attribute to the
112 -- designated subprogram and then in the tagged case, provide this as
113 -- a primitive operation, or in the non-tagged case make an appropriate
114 -- TSS entry. Used for Read, Output, Write.
115
116 procedure Check_Constant_Address_Clause (Expr : Node_Id; U_Ent : Entity_Id);
117 -- Expr is an expression for an address clause. This procedure checks
118 -- that the expression is constant, in the limited sense that it is safe
119 -- to evaluate it at the point the object U_Ent is declared, rather than
120 -- at the point of the address clause. The condition for this to be true
121 -- is that the expression has no variables, no constants declared after
122 -- U_Ent, and no calls to non-pure functions. If this condition is not
123 -- met, then an appropriate error message is posted.
124
125 procedure Warn_Overlay
126 (Expr : Node_Id;
127 Typ : Entity_Id;
128 Nam : Node_Id);
129 -- Expr is the expression for an address clause for entity Nam whose type
130 -- is Typ. If Typ has a default initialization, check whether the address
131 -- clause might overlay two entities, and emit a warning on the side effect
132 -- that the initialization will cause.
133
134 ----------------------------------------------
135 -- Table for Validate_Unchecked_Conversions --
136 ----------------------------------------------
137
138 -- The following table collects unchecked conversions for validation.
139 -- Entries are made by Validate_Unchecked_Conversion and then the
140 -- call to Validate_Unchecked_Conversions does the actual error
141 -- checking and posting of warnings. The reason for this delayed
142 -- processing is to take advantage of back-annotations of size and
143 -- alignment values peformed by the back end.
144
145 type UC_Entry is record
146 Enode : Node_Id; -- node used for posting warnings
147 Source : Entity_Id; -- source type for unchecked conversion
148 Target : Entity_Id; -- target type for unchecked conversion
149 end record;
150
151 package Unchecked_Conversions is new Table.Table (
152 Table_Component_Type => UC_Entry,
153 Table_Index_Type => Int,
154 Table_Low_Bound => 1,
155 Table_Initial => 50,
156 Table_Increment => 200,
157 Table_Name => "Unchecked_Conversions");
158
159 --------------------------------------
160 -- Alignment_Check_For_Esize_Change --
161 --------------------------------------
162
163 procedure Alignment_Check_For_Esize_Change (Typ : Entity_Id) is
164 begin
165 -- If the alignment is known, and not set by a rep clause, and is
166 -- inconsistent with the size being set, then reset it to unknown,
167 -- we assume in this case that the size overrides the inherited
168 -- alignment, and that the alignment must be recomputed.
169
170 if Known_Alignment (Typ)
171 and then not Has_Alignment_Clause (Typ)
172 and then Esize (Typ) mod (Alignment (Typ) * SSU) /= 0
173 then
174 Init_Alignment (Typ);
175 end if;
176 end Alignment_Check_For_Esize_Change;
177
178 -----------------------
179 -- Analyze_At_Clause --
180 -----------------------
181
182 -- An at clause is replaced by the corresponding Address attribute
183 -- definition clause that is the preferred approach in Ada 95.
184
185 procedure Analyze_At_Clause (N : Node_Id) is
186 begin
187 Rewrite (N,
188 Make_Attribute_Definition_Clause (Sloc (N),
189 Name => Identifier (N),
190 Chars => Name_Address,
191 Expression => Expression (N)));
192 Analyze_Attribute_Definition_Clause (N);
193 end Analyze_At_Clause;
194
195 -----------------------------------------
196 -- Analyze_Attribute_Definition_Clause --
197 -----------------------------------------
198
199 procedure Analyze_Attribute_Definition_Clause (N : Node_Id) is
200 Loc : constant Source_Ptr := Sloc (N);
201 Nam : constant Node_Id := Name (N);
202 Attr : constant Name_Id := Chars (N);
203 Expr : constant Node_Id := Expression (N);
204 Id : constant Attribute_Id := Get_Attribute_Id (Attr);
205 Ent : Entity_Id;
206 U_Ent : Entity_Id;
207
208 FOnly : Boolean := False;
209 -- Reset to True for subtype specific attribute (Alignment, Size)
210 -- and for stream attributes, i.e. those cases where in the call
211 -- to Rep_Item_Too_Late, FOnly is set True so that only the freezing
212 -- rules are checked. Note that the case of stream attributes is not
213 -- clear from the RM, but see AI95-00137. Also, the RM seems to
214 -- disallow Storage_Size for derived task types, but that is also
215 -- clearly unintentional.
216
217 begin
218 Analyze (Nam);
219 Ent := Entity (Nam);
220
221 if Rep_Item_Too_Early (Ent, N) then
222 return;
223 end if;
224
225 -- Rep clause applies to full view of incomplete type or private type
226 -- if we have one (if not, this is a premature use of the type).
227 -- However, certain semantic checks need to be done on the specified
228 -- entity (i.e. the private view), so we save it in Ent.
229
230 if Is_Private_Type (Ent)
231 and then Is_Derived_Type (Ent)
232 and then not Is_Tagged_Type (Ent)
233 and then No (Full_View (Ent))
234 then
235 -- If this is a private type whose completion is a derivation
236 -- from another private type, there is no full view, and the
237 -- attribute belongs to the type itself, not its underlying parent.
238
239 U_Ent := Ent;
240
241 elsif Ekind (Ent) = E_Incomplete_Type then
242 Ent := Underlying_Type (Ent);
243 U_Ent := Ent;
244 else
245 U_Ent := Underlying_Type (Ent);
246 end if;
247
248 -- Complete other routine error checks
249
250 if Etype (Nam) = Any_Type then
251 return;
252
253 elsif Scope (Ent) /= Current_Scope then
254 Error_Msg_N ("entity must be declared in this scope", Nam);
255 return;
256
257 elsif No (U_Ent) then
258 U_Ent := Ent;
259
260 elsif Is_Type (U_Ent)
261 and then not Is_First_Subtype (U_Ent)
262 and then Id /= Attribute_Object_Size
263 and then Id /= Attribute_Value_Size
264 and then not From_At_Mod (N)
265 then
266 Error_Msg_N ("cannot specify attribute for subtype", Nam);
267 return;
268
269 end if;
270
271 -- Switch on particular attribute
272
273 case Id is
274
275 -------------
276 -- Address --
277 -------------
278
279 -- Address attribute definition clause
280
281 when Attribute_Address => Address : begin
282 Analyze_And_Resolve (Expr, RTE (RE_Address));
283
284 if Present (Address_Clause (U_Ent)) then
285 Error_Msg_N ("address already given for &", Nam);
286
287 -- Case of address clause for subprogram
288
289 elsif Is_Subprogram (U_Ent) then
290
291 if Has_Homonym (U_Ent) then
292 Error_Msg_N
293 ("address clause cannot be given " &
294 "for overloaded subprogram",
295 Nam);
296 end if;
297
298 -- For subprograms, all address clauses are permitted,
299 -- and we mark the subprogram as having a deferred freeze
300 -- so that Gigi will not elaborate it too soon.
301
302 -- Above needs more comments, what is too soon about???
303
304 Set_Has_Delayed_Freeze (U_Ent);
305
306 -- Case of address clause for entry
307
308 elsif Ekind (U_Ent) = E_Entry then
309
310 if Nkind (Parent (N)) = N_Task_Body then
311 Error_Msg_N
312 ("entry address must be specified in task spec", Nam);
313 end if;
314
315 -- For entries, we require a constant address
316
317 Check_Constant_Address_Clause (Expr, U_Ent);
318
319 if Is_Task_Type (Scope (U_Ent))
320 and then Comes_From_Source (Scope (U_Ent))
321 then
322 Error_Msg_N
323 ("?entry address declared for entry in task type", N);
324 Error_Msg_N
325 ("\?only one task can be declared of this type", N);
326 end if;
327
328 -- Case of address clause for an object
329
330 elsif
331 Ekind (U_Ent) = E_Variable
332 or else
333 Ekind (U_Ent) = E_Constant
334 then
335 declare
336 Decl : constant Node_Id := Declaration_Node (U_Ent);
337 Expr : constant Node_Id := Expression (N);
338 Typ : constant Entity_Id := Etype (U_Ent);
339
340 begin
341 -- Exported variables cannot have an address clause,
342 -- because this cancels the effect of the pragma Export
343
344 if Is_Exported (U_Ent) then
345 Error_Msg_N
346 ("cannot export object with address clause", Nam);
347
348 -- Imported variables can have an address clause, but then
349 -- the import is pretty meaningless except to suppress
350 -- initializations, so we do not need such variables to
351 -- be statically allocated (and in fact it causes trouble
352 -- if the address clause is a local value).
353
354 elsif Is_Imported (U_Ent) then
355 Set_Is_Statically_Allocated (U_Ent, False);
356 end if;
357
358 -- We mark a possible modification of a variable with an
359 -- address clause, since it is likely aliasing is occurring.
360
361 Note_Possible_Modification (Nam);
362
363 -- If we have no initialization of any kind, then we can
364 -- safely defer the elaboration of the variable to its
365 -- freezing point, so that the address clause will be
366 -- computed at the proper point.
367
368 -- The same processing applies to all initialized scalar
369 -- types and all access types. Packed bit arrays of size
370 -- up to 64 are represented using a modular type with an
371 -- initialization (to zero) and can be processed like
372 -- other initialized scalar types.
373
374 if (No (Expression (Decl))
375 and then not Has_Non_Null_Base_Init_Proc (Typ))
376
377 or else
378 (Present (Expression (Decl))
379 and then Is_Scalar_Type (Typ))
380
381 or else
382 Is_Access_Type (Typ)
383
384 or else
385 (Is_Bit_Packed_Array (Base_Type (Typ))
386 and then
387 Is_Modular_Integer_Type (Packed_Array_Type (Typ)))
388 then
389 Set_Has_Delayed_Freeze (U_Ent);
390
391 -- Otherwise, we require the address clause to be constant
392
393 else
394 Check_Constant_Address_Clause (Expr, U_Ent);
395 end if;
396
397 if Is_Exported (U_Ent) then
398 Error_Msg_N
399 ("& cannot be exported if an address clause is given",
400 Nam);
401 Error_Msg_N
402 ("\define and export a variable " &
403 "that holds its address instead",
404 Nam);
405 end if;
406
407 if not Error_Posted (Expr) then
408 Warn_Overlay (Expr, Typ, Nam);
409 end if;
410
411 -- If entity has delayed freeze then we will generate
412 -- an alignment check at the freeze point. If there is
413 -- no delayed freeze we can do it right now.
414
415 if not Has_Delayed_Freeze (U_Ent) then
416 Apply_Alignment_Check (U_Ent, N);
417 end if;
418
419 -- Kill the size check code, since we are not allocating
420 -- the variable, it is somewhere else.
421
422 Kill_Size_Check_Code (U_Ent);
423 end;
424
425 -- Not a valid entity for an address clause
426
427 else
428 Error_Msg_N ("address cannot be given for &", Nam);
429 end if;
430 end Address;
431
432 ---------------
433 -- Alignment --
434 ---------------
435
436 -- Alignment attribute definition clause
437
438 when Attribute_Alignment => Alignment_Block : declare
439 Align : Uint := Get_Alignment_Value (Expr);
440
441 begin
442 FOnly := True;
443
444 if not Is_Type (U_Ent)
445 and then Ekind (U_Ent) /= E_Variable
446 and then Ekind (U_Ent) /= E_Constant
447 then
448 Error_Msg_N ("alignment cannot be given for &", Nam);
449
450 elsif Has_Alignment_Clause (U_Ent) then
451 Error_Msg_Sloc := Sloc (Alignment_Clause (U_Ent));
452 Error_Msg_N ("alignment clause previously given#", N);
453
454 elsif Align /= No_Uint then
455 Set_Has_Alignment_Clause (U_Ent);
456 Set_Alignment (U_Ent, Align);
457 end if;
458 end Alignment_Block;
459
460 ---------------
461 -- Bit_Order --
462 ---------------
463
464 -- Bit_Order attribute definition clause
465
466 when Attribute_Bit_Order => Bit_Order : declare
467 begin
468 if not Is_Record_Type (U_Ent) then
469 Error_Msg_N
470 ("Bit_Order can only be defined for record type", Nam);
471
472 else
473 Analyze_And_Resolve (Expr, RTE (RE_Bit_Order));
474
475 if Etype (Expr) = Any_Type then
476 return;
477
478 elsif not Is_Static_Expression (Expr) then
479 Error_Msg_N ("Bit_Order requires static expression", Expr);
480
481 else
482 if (Expr_Value (Expr) = 0) /= Bytes_Big_Endian then
483 Set_Reverse_Bit_Order (U_Ent, True);
484 end if;
485 end if;
486 end if;
487 end Bit_Order;
488
489 --------------------
490 -- Component_Size --
491 --------------------
492
493 -- Component_Size attribute definition clause
494
495 when Attribute_Component_Size => Component_Size_Case : declare
496 Csize : constant Uint := Static_Integer (Expr);
497 Btype : Entity_Id;
498 Biased : Boolean;
499 New_Ctyp : Entity_Id;
500 Decl : Node_Id;
501
502 begin
503 if not Is_Array_Type (U_Ent) then
504 Error_Msg_N ("component size requires array type", Nam);
505 return;
506 end if;
507
508 Btype := Base_Type (U_Ent);
509
510 if Has_Component_Size_Clause (Btype) then
511 Error_Msg_N
512 ("component size clase for& previously given", Nam);
513
514 elsif Csize /= No_Uint then
515 Check_Size (Expr, Component_Type (Btype), Csize, Biased);
516
517 if Has_Aliased_Components (Btype)
518 and then Csize < 32
519 and then Csize /= 8
520 and then Csize /= 16
521 then
522 Error_Msg_N
523 ("component size incorrect for aliased components", N);
524 return;
525 end if;
526
527 -- For the biased case, build a declaration for a subtype
528 -- that will be used to represent the biased subtype that
529 -- reflects the biased representation of components. We need
530 -- this subtype to get proper conversions on referencing
531 -- elements of the array.
532
533 if Biased then
534 New_Ctyp :=
535 Make_Defining_Identifier (Loc,
536 Chars => New_External_Name (Chars (U_Ent), 'C', 0, 'T'));
537
538 Decl :=
539 Make_Subtype_Declaration (Loc,
540 Defining_Identifier => New_Ctyp,
541 Subtype_Indication =>
542 New_Occurrence_Of (Component_Type (Btype), Loc));
543
544 Set_Parent (Decl, N);
545 Analyze (Decl, Suppress => All_Checks);
546
547 Set_Has_Delayed_Freeze (New_Ctyp, False);
548 Set_Esize (New_Ctyp, Csize);
549 Set_RM_Size (New_Ctyp, Csize);
550 Init_Alignment (New_Ctyp);
551 Set_Has_Biased_Representation (New_Ctyp, True);
552 Set_Is_Itype (New_Ctyp, True);
553 Set_Associated_Node_For_Itype (New_Ctyp, U_Ent);
554
555 Set_Component_Type (Btype, New_Ctyp);
556 end if;
557
558 Set_Component_Size (Btype, Csize);
559 Set_Has_Component_Size_Clause (Btype, True);
560 Set_Has_Non_Standard_Rep (Btype, True);
561 end if;
562 end Component_Size_Case;
563
564 ------------------
565 -- External_Tag --
566 ------------------
567
568 when Attribute_External_Tag => External_Tag :
569 begin
570 if not Is_Tagged_Type (U_Ent) then
571 Error_Msg_N ("should be a tagged type", Nam);
572 end if;
573
574 Analyze_And_Resolve (Expr, Standard_String);
575
576 if not Is_Static_Expression (Expr) then
577 Error_Msg_N ("must be a static string", Nam);
578 end if;
579
580 Set_Has_External_Tag_Rep_Clause (U_Ent);
581 end External_Tag;
582
583 -----------
584 -- Input --
585 -----------
586
587 when Attribute_Input => Input : declare
588 Subp : Entity_Id := Empty;
589 I : Interp_Index;
590 It : Interp;
591 Pnam : Entity_Id;
592
593 function Has_Good_Profile (Subp : Entity_Id) return Boolean;
594 -- Return true if the entity is a function with an appropriate
595 -- profile for the Input attribute.
596
597 function Has_Good_Profile (Subp : Entity_Id) return Boolean is
598 F : Entity_Id;
599 Ok : Boolean := False;
600
601 begin
602 if Ekind (Subp) = E_Function then
603 F := First_Formal (Subp);
604
605 if Present (F) and then No (Next_Formal (F)) then
606 if Ekind (Etype (F)) = E_Anonymous_Access_Type
607 and then
608 Designated_Type (Etype (F)) =
609 Class_Wide_Type (RTE (RE_Root_Stream_Type))
610 then
611 Ok := Base_Type (Etype (Subp)) = Base_Type (Ent);
612 end if;
613 end if;
614 end if;
615
616 return Ok;
617 end Has_Good_Profile;
618
619 -- Start of processing for Input attribute definition
620
621 begin
622 FOnly := True;
623
624 if not Is_Type (U_Ent) then
625 Error_Msg_N ("local name must be a subtype", Nam);
626 return;
627
628 else
629 Pnam := TSS (Base_Type (U_Ent), Name_uInput);
630
631 if Present (Pnam)
632 and then Base_Type (Etype (Pnam)) = Base_Type (U_Ent)
633 then
634 Error_Msg_Sloc := Sloc (Pnam);
635 Error_Msg_N ("input attribute already defined #", Nam);
636 return;
637 end if;
638 end if;
639
640 Analyze (Expr);
641
642 if Is_Entity_Name (Expr) then
643 if not Is_Overloaded (Expr) then
644 if Has_Good_Profile (Entity (Expr)) then
645 Subp := Entity (Expr);
646 end if;
647
648 else
649 Get_First_Interp (Expr, I, It);
650
651 while Present (It.Nam) loop
652 if Has_Good_Profile (It.Nam) then
653 Subp := It.Nam;
654 exit;
655 end if;
656
657 Get_Next_Interp (I, It);
658 end loop;
659 end if;
660 end if;
661
662 if Present (Subp) then
663 Set_Entity (Expr, Subp);
664 Set_Etype (Expr, Etype (Subp));
665 New_Stream_Function (N, U_Ent, Subp, Name_uInput);
666 else
667 Error_Msg_N ("incorrect expression for input attribute", Expr);
668 return;
669 end if;
670 end Input;
671
672 -------------------
673 -- Machine_Radix --
674 -------------------
675
676 -- Machine radix attribute definition clause
677
678 when Attribute_Machine_Radix => Machine_Radix : declare
679 Radix : constant Uint := Static_Integer (Expr);
680
681 begin
682 if not Is_Decimal_Fixed_Point_Type (U_Ent) then
683 Error_Msg_N ("decimal fixed-point type expected for &", Nam);
684
685 elsif Has_Machine_Radix_Clause (U_Ent) then
686 Error_Msg_Sloc := Sloc (Alignment_Clause (U_Ent));
687 Error_Msg_N ("machine radix clause previously given#", N);
688
689 elsif Radix /= No_Uint then
690 Set_Has_Machine_Radix_Clause (U_Ent);
691 Set_Has_Non_Standard_Rep (Base_Type (U_Ent));
692
693 if Radix = 2 then
694 null;
695 elsif Radix = 10 then
696 Set_Machine_Radix_10 (U_Ent);
697 else
698 Error_Msg_N ("machine radix value must be 2 or 10", Expr);
699 end if;
700 end if;
701 end Machine_Radix;
702
703 -----------------
704 -- Object_Size --
705 -----------------
706
707 -- Object_Size attribute definition clause
708
709 when Attribute_Object_Size => Object_Size : declare
710 Size : constant Uint := Static_Integer (Expr);
711 Biased : Boolean;
712
713 begin
714 if not Is_Type (U_Ent) then
715 Error_Msg_N ("Object_Size cannot be given for &", Nam);
716
717 elsif Has_Object_Size_Clause (U_Ent) then
718 Error_Msg_N ("Object_Size already given for &", Nam);
719
720 else
721 Check_Size (Expr, U_Ent, Size, Biased);
722
723 if Size /= 8
724 and then
725 Size /= 16
726 and then
727 Size /= 32
728 and then
729 UI_Mod (Size, 64) /= 0
730 then
731 Error_Msg_N
732 ("Object_Size must be 8, 16, 32, or multiple of 64",
733 Expr);
734 end if;
735
736 Set_Esize (U_Ent, Size);
737 Set_Has_Object_Size_Clause (U_Ent);
738 Alignment_Check_For_Esize_Change (U_Ent);
739 end if;
740 end Object_Size;
741
742 ------------
743 -- Output --
744 ------------
745
746 when Attribute_Output => Output : declare
747 Subp : Entity_Id := Empty;
748 I : Interp_Index;
749 It : Interp;
750 Pnam : Entity_Id;
751
752 function Has_Good_Profile (Subp : Entity_Id) return Boolean;
753 -- Return true if the entity is a procedure with an
754 -- appropriate profile for the output attribute.
755
756 function Has_Good_Profile (Subp : Entity_Id) return Boolean is
757 F : Entity_Id;
758 Ok : Boolean := False;
759
760 begin
761 if Ekind (Subp) = E_Procedure then
762 F := First_Formal (Subp);
763
764 if Present (F) then
765 if Ekind (Etype (F)) = E_Anonymous_Access_Type
766 and then
767 Designated_Type (Etype (F)) =
768 Class_Wide_Type (RTE (RE_Root_Stream_Type))
769 then
770 Next_Formal (F);
771 Ok := Present (F)
772 and then Parameter_Mode (F) = E_In_Parameter
773 and then Base_Type (Etype (F)) = Base_Type (Ent)
774 and then No (Next_Formal (F));
775 end if;
776 end if;
777 end if;
778
779 return Ok;
780 end Has_Good_Profile;
781
782 begin
783 FOnly := True;
784
785 if not Is_Type (U_Ent) then
786 Error_Msg_N ("local name must be a subtype", Nam);
787 return;
788
789 else
790 Pnam := TSS (Base_Type (U_Ent), Name_uOutput);
791
792 if Present (Pnam)
793 and then
794 Base_Type (Etype (Next_Formal (First_Formal (Pnam))))
795 = Base_Type (U_Ent)
796 then
797 Error_Msg_Sloc := Sloc (Pnam);
798 Error_Msg_N ("output attribute already defined #", Nam);
799 return;
800 end if;
801 end if;
802
803 Analyze (Expr);
804
805 if Is_Entity_Name (Expr) then
806 if not Is_Overloaded (Expr) then
807 if Has_Good_Profile (Entity (Expr)) then
808 Subp := Entity (Expr);
809 end if;
810
811 else
812 Get_First_Interp (Expr, I, It);
813
814 while Present (It.Nam) loop
815 if Has_Good_Profile (It.Nam) then
816 Subp := It.Nam;
817 exit;
818 end if;
819
820 Get_Next_Interp (I, It);
821 end loop;
822 end if;
823 end if;
824
825 if Present (Subp) then
826 Set_Entity (Expr, Subp);
827 Set_Etype (Expr, Etype (Subp));
828 New_Stream_Procedure (N, U_Ent, Subp, Name_uOutput);
829 else
830 Error_Msg_N ("incorrect expression for output attribute", Expr);
831 return;
832 end if;
833 end Output;
834
835 ----------
836 -- Read --
837 ----------
838
839 when Attribute_Read => Read : declare
840 Subp : Entity_Id := Empty;
841 I : Interp_Index;
842 It : Interp;
843 Pnam : Entity_Id;
844
845 function Has_Good_Profile (Subp : Entity_Id) return Boolean;
846 -- Return true if the entity is a procedure with an appropriate
847 -- profile for the Read attribute.
848
849 function Has_Good_Profile (Subp : Entity_Id) return Boolean is
850 F : Entity_Id;
851 Ok : Boolean := False;
852
853 begin
854 if Ekind (Subp) = E_Procedure then
855 F := First_Formal (Subp);
856
857 if Present (F) then
858 if Ekind (Etype (F)) = E_Anonymous_Access_Type
859 and then
860 Designated_Type (Etype (F)) =
861 Class_Wide_Type (RTE (RE_Root_Stream_Type))
862 then
863 Next_Formal (F);
864 Ok := Present (F)
865 and then Parameter_Mode (F) = E_Out_Parameter
866 and then Base_Type (Etype (F)) = Base_Type (Ent)
867 and then No (Next_Formal (F));
868 end if;
869 end if;
870 end if;
871
872 return Ok;
873 end Has_Good_Profile;
874
875 -- Start of processing for Read attribute definition
876
877 begin
878 FOnly := True;
879
880 if not Is_Type (U_Ent) then
881 Error_Msg_N ("local name must be a subtype", Nam);
882 return;
883
884 else
885 Pnam := TSS (Base_Type (U_Ent), Name_uRead);
886
887 if Present (Pnam)
888 and then Base_Type (Etype (Next_Formal (First_Formal (Pnam))))
889 = Base_Type (U_Ent)
890 then
891 Error_Msg_Sloc := Sloc (Pnam);
892 Error_Msg_N ("read attribute already defined #", Nam);
893 return;
894 end if;
895 end if;
896
897 Analyze (Expr);
898
899 if Is_Entity_Name (Expr) then
900 if not Is_Overloaded (Expr) then
901 if Has_Good_Profile (Entity (Expr)) then
902 Subp := Entity (Expr);
903 end if;
904
905 else
906 Get_First_Interp (Expr, I, It);
907
908 while Present (It.Nam) loop
909 if Has_Good_Profile (It.Nam) then
910 Subp := It.Nam;
911 exit;
912 end if;
913
914 Get_Next_Interp (I, It);
915 end loop;
916 end if;
917 end if;
918
919 if Present (Subp) then
920 Set_Entity (Expr, Subp);
921 Set_Etype (Expr, Etype (Subp));
922 New_Stream_Procedure (N, U_Ent, Subp, Name_uRead, True);
923 else
924 Error_Msg_N ("incorrect expression for read attribute", Expr);
925 return;
926 end if;
927 end Read;
928
929 ----------
930 -- Size --
931 ----------
932
933 -- Size attribute definition clause
934
935 when Attribute_Size => Size : declare
936 Size : constant Uint := Static_Integer (Expr);
937 Etyp : Entity_Id;
938 Biased : Boolean;
939
940 begin
941 FOnly := True;
942
943 if Has_Size_Clause (U_Ent) then
944 Error_Msg_N ("size already given for &", Nam);
945
946 elsif not Is_Type (U_Ent)
947 and then Ekind (U_Ent) /= E_Variable
948 and then Ekind (U_Ent) /= E_Constant
949 then
950 Error_Msg_N ("size cannot be given for &", Nam);
951
952 elsif Is_Array_Type (U_Ent)
953 and then not Is_Constrained (U_Ent)
954 then
955 Error_Msg_N
956 ("size cannot be given for unconstrained array", Nam);
957
958 elsif Size /= No_Uint then
959
960 if Is_Type (U_Ent) then
961 Etyp := U_Ent;
962 else
963 Etyp := Etype (U_Ent);
964 end if;
965
966 -- Check size, note that Gigi is in charge of checking
967 -- that the size of an array or record type is OK. Also
968 -- we do not check the size in the ordinary fixed-point
969 -- case, since it is too early to do so (there may be a
970 -- subsequent small clause that affects the size). We can
971 -- check the size if a small clause has already been given.
972
973 if not Is_Ordinary_Fixed_Point_Type (U_Ent)
974 or else Has_Small_Clause (U_Ent)
975 then
976 Check_Size (Expr, Etyp, Size, Biased);
977 Set_Has_Biased_Representation (U_Ent, Biased);
978 end if;
979
980 -- For types set RM_Size and Esize if possible
981
982 if Is_Type (U_Ent) then
983 Set_RM_Size (U_Ent, Size);
984
985 -- For scalar types, increase Object_Size to power of 2,
986 -- but not less than a storage unit in any case (i.e.,
987 -- normally this means it will be byte addressable).
988
989 if Is_Scalar_Type (U_Ent) then
990 if Size <= System_Storage_Unit then
991 Init_Esize (U_Ent, System_Storage_Unit);
992 elsif Size <= 16 then
993 Init_Esize (U_Ent, 16);
994 elsif Size <= 32 then
995 Init_Esize (U_Ent, 32);
996 else
997 Set_Esize (U_Ent, (Size + 63) / 64 * 64);
998 end if;
999
1000 -- For all other types, object size = value size. The
1001 -- backend will adjust as needed.
1002
1003 else
1004 Set_Esize (U_Ent, Size);
1005 end if;
1006
1007 Alignment_Check_For_Esize_Change (U_Ent);
1008
1009 -- For objects, set Esize only
1010
1011 else
1012 Set_Esize (U_Ent, Size);
1013 end if;
1014
1015 Set_Has_Size_Clause (U_Ent);
1016 end if;
1017 end Size;
1018
1019 -----------
1020 -- Small --
1021 -----------
1022
1023 -- Small attribute definition clause
1024
1025 when Attribute_Small => Small : declare
1026 Implicit_Base : constant Entity_Id := Base_Type (U_Ent);
1027 Small : Ureal;
1028
1029 begin
1030 Analyze_And_Resolve (Expr, Any_Real);
1031
1032 if Etype (Expr) = Any_Type then
1033 return;
1034
1035 elsif not Is_Static_Expression (Expr) then
1036 Error_Msg_N ("small requires static expression", Expr);
1037 return;
1038
1039 else
1040 Small := Expr_Value_R (Expr);
1041
1042 if Small <= Ureal_0 then
1043 Error_Msg_N ("small value must be greater than zero", Expr);
1044 return;
1045 end if;
1046
1047 end if;
1048
1049 if not Is_Ordinary_Fixed_Point_Type (U_Ent) then
1050 Error_Msg_N
1051 ("small requires an ordinary fixed point type", Nam);
1052
1053 elsif Has_Small_Clause (U_Ent) then
1054 Error_Msg_N ("small already given for &", Nam);
1055
1056 elsif Small > Delta_Value (U_Ent) then
1057 Error_Msg_N
1058 ("small value must not be greater then delta value", Nam);
1059
1060 else
1061 Set_Small_Value (U_Ent, Small);
1062 Set_Small_Value (Implicit_Base, Small);
1063 Set_Has_Small_Clause (U_Ent);
1064 Set_Has_Small_Clause (Implicit_Base);
1065 Set_Has_Non_Standard_Rep (Implicit_Base);
1066 end if;
1067 end Small;
1068
1069 ------------------
1070 -- Storage_Size --
1071 ------------------
1072
1073 -- Storage_Size attribute definition clause
1074
1075 when Attribute_Storage_Size => Storage_Size : declare
1076 Btype : constant Entity_Id := Base_Type (U_Ent);
1077 Sprag : Node_Id;
1078
1079 begin
1080 if Is_Task_Type (U_Ent) then
1081 FOnly := True;
1082 end if;
1083
1084 if not Is_Access_Type (U_Ent)
1085 and then Ekind (U_Ent) /= E_Task_Type
1086 then
1087 Error_Msg_N ("storage size cannot be given for &", Nam);
1088
1089 elsif Is_Access_Type (U_Ent) and Is_Derived_Type (U_Ent) then
1090 Error_Msg_N
1091 ("storage size cannot be given for a derived access type",
1092 Nam);
1093
1094 elsif Has_Storage_Size_Clause (Btype) then
1095 Error_Msg_N ("storage size already given for &", Nam);
1096
1097 else
1098 Analyze_And_Resolve (Expr, Any_Integer);
1099
1100 if Is_Access_Type (U_Ent) then
1101
1102 if Present (Associated_Storage_Pool (U_Ent)) then
1103 Error_Msg_N ("storage pool already given for &", Nam);
1104 return;
1105 end if;
1106
1107 if Compile_Time_Known_Value (Expr)
1108 and then Expr_Value (Expr) = 0
1109 then
1110 Set_No_Pool_Assigned (Btype);
1111 end if;
1112
1113 else -- Is_Task_Type (U_Ent)
1114 Sprag := Get_Rep_Pragma (Btype, Name_Storage_Size);
1115
1116 if Present (Sprag) then
1117 Error_Msg_Sloc := Sloc (Sprag);
1118 Error_Msg_N
1119 ("Storage_Size already specified#", Nam);
1120 return;
1121 end if;
1122 end if;
1123
1124 Set_Has_Storage_Size_Clause (Btype);
1125 end if;
1126 end Storage_Size;
1127
1128 ------------------
1129 -- Storage_Pool --
1130 ------------------
1131
1132 -- Storage_Pool attribute definition clause
1133
1134 when Attribute_Storage_Pool => Storage_Pool : declare
1135 Pool : Entity_Id;
1136
1137 begin
1138 if Ekind (U_Ent) /= E_Access_Type
1139 and then Ekind (U_Ent) /= E_General_Access_Type
1140 then
1141 Error_Msg_N (
1142 "storage pool can only be given for access types", Nam);
1143 return;
1144
1145 elsif Is_Derived_Type (U_Ent) then
1146 Error_Msg_N
1147 ("storage pool cannot be given for a derived access type",
1148 Nam);
1149
1150 elsif Has_Storage_Size_Clause (U_Ent) then
1151 Error_Msg_N ("storage size already given for &", Nam);
1152 return;
1153
1154 elsif Present (Associated_Storage_Pool (U_Ent)) then
1155 Error_Msg_N ("storage pool already given for &", Nam);
1156 return;
1157 end if;
1158
1159 Analyze_And_Resolve
1160 (Expr, Class_Wide_Type (RTE (RE_Root_Storage_Pool)));
1161
1162 -- If the argument is a name that is not an entity name, then
1163 -- we construct a renaming operation to define an entity of
1164 -- type storage pool.
1165
1166 if not Is_Entity_Name (Expr)
1167 and then Is_Object_Reference (Expr)
1168 then
1169 Pool :=
1170 Make_Defining_Identifier (Loc,
1171 Chars => New_Internal_Name ('P'));
1172
1173 declare
1174 Rnode : constant Node_Id :=
1175 Make_Object_Renaming_Declaration (Loc,
1176 Defining_Identifier => Pool,
1177 Subtype_Mark =>
1178 New_Occurrence_Of (Etype (Expr), Loc),
1179 Name => Expr);
1180
1181 begin
1182 Insert_Before (N, Rnode);
1183 Analyze (Rnode);
1184 Set_Associated_Storage_Pool (U_Ent, Pool);
1185 end;
1186
1187 elsif Is_Entity_Name (Expr) then
1188 Pool := Entity (Expr);
1189
1190 -- If pool is a renamed object, get original one. This can
1191 -- happen with an explicit renaming, and within instances.
1192
1193 while Present (Renamed_Object (Pool))
1194 and then Is_Entity_Name (Renamed_Object (Pool))
1195 loop
1196 Pool := Entity (Renamed_Object (Pool));
1197 end loop;
1198
1199 if Present (Renamed_Object (Pool))
1200 and then Nkind (Renamed_Object (Pool)) = N_Type_Conversion
1201 and then Is_Entity_Name (Expression (Renamed_Object (Pool)))
1202 then
1203 Pool := Entity (Expression (Renamed_Object (Pool)));
1204 end if;
1205
1206 if Present (Etype (Pool))
1207 and then Etype (Pool) /= RTE (RE_Stack_Bounded_Pool)
1208 and then Etype (Pool) /= RTE (RE_Unbounded_Reclaim_Pool)
1209 then
1210 Set_Associated_Storage_Pool (U_Ent, Pool);
1211 else
1212 Error_Msg_N ("Non sharable GNAT Pool", Expr);
1213 end if;
1214
1215 -- The pool may be specified as the Storage_Pool of some other
1216 -- type. It is rewritten as a class_wide conversion of the
1217 -- corresponding pool entity.
1218
1219 elsif Nkind (Expr) = N_Type_Conversion
1220 and then Is_Entity_Name (Expression (Expr))
1221 and then Nkind (Original_Node (Expr)) = N_Attribute_Reference
1222 then
1223 Pool := Entity (Expression (Expr));
1224
1225 if Present (Etype (Pool))
1226 and then Etype (Pool) /= RTE (RE_Stack_Bounded_Pool)
1227 and then Etype (Pool) /= RTE (RE_Unbounded_Reclaim_Pool)
1228 then
1229 Set_Associated_Storage_Pool (U_Ent, Pool);
1230 else
1231 Error_Msg_N ("Non sharable GNAT Pool", Expr);
1232 end if;
1233
1234 else
1235 Error_Msg_N ("incorrect reference to a Storage Pool", Expr);
1236 return;
1237 end if;
1238 end Storage_Pool;
1239
1240 ----------------
1241 -- Value_Size --
1242 ----------------
1243
1244 -- Value_Size attribute definition clause
1245
1246 when Attribute_Value_Size => Value_Size : declare
1247 Size : constant Uint := Static_Integer (Expr);
1248 Biased : Boolean;
1249
1250 begin
1251 if not Is_Type (U_Ent) then
1252 Error_Msg_N ("Value_Size cannot be given for &", Nam);
1253
1254 elsif Present
1255 (Get_Attribute_Definition_Clause
1256 (U_Ent, Attribute_Value_Size))
1257 then
1258 Error_Msg_N ("Value_Size already given for &", Nam);
1259
1260 else
1261 if Is_Elementary_Type (U_Ent) then
1262 Check_Size (Expr, U_Ent, Size, Biased);
1263 Set_Has_Biased_Representation (U_Ent, Biased);
1264 end if;
1265
1266 Set_RM_Size (U_Ent, Size);
1267 end if;
1268 end Value_Size;
1269
1270 -----------
1271 -- Write --
1272 -----------
1273
1274 -- Write attribute definition clause
1275 -- check for class-wide case will be performed later
1276
1277 when Attribute_Write => Write : declare
1278 Subp : Entity_Id := Empty;
1279 I : Interp_Index;
1280 It : Interp;
1281 Pnam : Entity_Id;
1282
1283 function Has_Good_Profile (Subp : Entity_Id) return Boolean;
1284 -- Return true if the entity is a procedure with an
1285 -- appropriate profile for the write attribute.
1286
1287 function Has_Good_Profile (Subp : Entity_Id) return Boolean is
1288 F : Entity_Id;
1289 Ok : Boolean := False;
1290
1291 begin
1292 if Ekind (Subp) = E_Procedure then
1293 F := First_Formal (Subp);
1294
1295 if Present (F) then
1296 if Ekind (Etype (F)) = E_Anonymous_Access_Type
1297 and then
1298 Designated_Type (Etype (F)) =
1299 Class_Wide_Type (RTE (RE_Root_Stream_Type))
1300 then
1301 Next_Formal (F);
1302 Ok := Present (F)
1303 and then Parameter_Mode (F) = E_In_Parameter
1304 and then Base_Type (Etype (F)) = Base_Type (Ent)
1305 and then No (Next_Formal (F));
1306 end if;
1307 end if;
1308 end if;
1309
1310 return Ok;
1311 end Has_Good_Profile;
1312
1313 -- Start of processing for Write attribute definition
1314
1315 begin
1316 FOnly := True;
1317
1318 if not Is_Type (U_Ent) then
1319 Error_Msg_N ("local name must be a subtype", Nam);
1320 return;
1321 end if;
1322
1323 Pnam := TSS (Base_Type (U_Ent), Name_uWrite);
1324
1325 if Present (Pnam)
1326 and then Base_Type (Etype (Next_Formal (First_Formal (Pnam))))
1327 = Base_Type (U_Ent)
1328 then
1329 Error_Msg_Sloc := Sloc (Pnam);
1330 Error_Msg_N ("write attribute already defined #", Nam);
1331 return;
1332 end if;
1333
1334 Analyze (Expr);
1335
1336 if Is_Entity_Name (Expr) then
1337 if not Is_Overloaded (Expr) then
1338 if Has_Good_Profile (Entity (Expr)) then
1339 Subp := Entity (Expr);
1340 end if;
1341
1342 else
1343 Get_First_Interp (Expr, I, It);
1344
1345 while Present (It.Nam) loop
1346 if Has_Good_Profile (It.Nam) then
1347 Subp := It.Nam;
1348 exit;
1349 end if;
1350
1351 Get_Next_Interp (I, It);
1352 end loop;
1353 end if;
1354 end if;
1355
1356 if Present (Subp) then
1357 Set_Entity (Expr, Subp);
1358 Set_Etype (Expr, Etype (Subp));
1359 New_Stream_Procedure (N, U_Ent, Subp, Name_uWrite);
1360 else
1361 Error_Msg_N ("incorrect expression for write attribute", Expr);
1362 return;
1363 end if;
1364 end Write;
1365
1366 -- All other attributes cannot be set
1367
1368 when others =>
1369 Error_Msg_N
1370 ("attribute& cannot be set with definition clause", N);
1371
1372 end case;
1373
1374 -- The test for the type being frozen must be performed after
1375 -- any expression the clause has been analyzed since the expression
1376 -- itself might cause freezing that makes the clause illegal.
1377
1378 if Rep_Item_Too_Late (U_Ent, N, FOnly) then
1379 return;
1380 end if;
1381 end Analyze_Attribute_Definition_Clause;
1382
1383 ----------------------------
1384 -- Analyze_Code_Statement --
1385 ----------------------------
1386
1387 procedure Analyze_Code_Statement (N : Node_Id) is
1388 HSS : constant Node_Id := Parent (N);
1389 SBody : constant Node_Id := Parent (HSS);
1390 Subp : constant Entity_Id := Current_Scope;
1391 Stmt : Node_Id;
1392 Decl : Node_Id;
1393 StmtO : Node_Id;
1394 DeclO : Node_Id;
1395
1396 begin
1397 -- Analyze and check we get right type, note that this implements the
1398 -- requirement (RM 13.8(1)) that Machine_Code be with'ed, since that
1399 -- is the only way that Asm_Insn could possibly be visible.
1400
1401 Analyze_And_Resolve (Expression (N));
1402
1403 if Etype (Expression (N)) = Any_Type then
1404 return;
1405 elsif Etype (Expression (N)) /= RTE (RE_Asm_Insn) then
1406 Error_Msg_N ("incorrect type for code statement", N);
1407 return;
1408 end if;
1409
1410 -- Make sure we appear in the handled statement sequence of a
1411 -- subprogram (RM 13.8(3)).
1412
1413 if Nkind (HSS) /= N_Handled_Sequence_Of_Statements
1414 or else Nkind (SBody) /= N_Subprogram_Body
1415 then
1416 Error_Msg_N
1417 ("code statement can only appear in body of subprogram", N);
1418 return;
1419 end if;
1420
1421 -- Do remaining checks (RM 13.8(3)) if not already done
1422
1423 if not Is_Machine_Code_Subprogram (Subp) then
1424 Set_Is_Machine_Code_Subprogram (Subp);
1425
1426 -- No exception handlers allowed
1427
1428 if Present (Exception_Handlers (HSS)) then
1429 Error_Msg_N
1430 ("exception handlers not permitted in machine code subprogram",
1431 First (Exception_Handlers (HSS)));
1432 end if;
1433
1434 -- No declarations other than use clauses and pragmas (we allow
1435 -- certain internally generated declarations as well).
1436
1437 Decl := First (Declarations (SBody));
1438 while Present (Decl) loop
1439 DeclO := Original_Node (Decl);
1440 if Comes_From_Source (DeclO)
1441 and then Nkind (DeclO) /= N_Pragma
1442 and then Nkind (DeclO) /= N_Use_Package_Clause
1443 and then Nkind (DeclO) /= N_Use_Type_Clause
1444 and then Nkind (DeclO) /= N_Implicit_Label_Declaration
1445 then
1446 Error_Msg_N
1447 ("this declaration not allowed in machine code subprogram",
1448 DeclO);
1449 end if;
1450
1451 Next (Decl);
1452 end loop;
1453
1454 -- No statements other than code statements, pragmas, and labels.
1455 -- Again we allow certain internally generated statements.
1456
1457 Stmt := First (Statements (HSS));
1458 while Present (Stmt) loop
1459 StmtO := Original_Node (Stmt);
1460 if Comes_From_Source (StmtO)
1461 and then Nkind (StmtO) /= N_Pragma
1462 and then Nkind (StmtO) /= N_Label
1463 and then Nkind (StmtO) /= N_Code_Statement
1464 then
1465 Error_Msg_N
1466 ("this statement is not allowed in machine code subprogram",
1467 StmtO);
1468 end if;
1469
1470 Next (Stmt);
1471 end loop;
1472 end if;
1473
1474 end Analyze_Code_Statement;
1475
1476 -----------------------------------------------
1477 -- Analyze_Enumeration_Representation_Clause --
1478 -----------------------------------------------
1479
1480 procedure Analyze_Enumeration_Representation_Clause (N : Node_Id) is
1481 Ident : constant Node_Id := Identifier (N);
1482 Aggr : constant Node_Id := Array_Aggregate (N);
1483 Enumtype : Entity_Id;
1484 Elit : Entity_Id;
1485 Expr : Node_Id;
1486 Assoc : Node_Id;
1487 Choice : Node_Id;
1488 Val : Uint;
1489 Err : Boolean := False;
1490
1491 Lo : constant Uint := Expr_Value (Type_Low_Bound (Universal_Integer));
1492 Hi : constant Uint := Expr_Value (Type_High_Bound (Universal_Integer));
1493 Min : Uint;
1494 Max : Uint;
1495
1496 begin
1497 -- First some basic error checks
1498
1499 Find_Type (Ident);
1500 Enumtype := Entity (Ident);
1501
1502 if Enumtype = Any_Type
1503 or else Rep_Item_Too_Early (Enumtype, N)
1504 then
1505 return;
1506 else
1507 Enumtype := Underlying_Type (Enumtype);
1508 end if;
1509
1510 if not Is_Enumeration_Type (Enumtype) then
1511 Error_Msg_NE
1512 ("enumeration type required, found}",
1513 Ident, First_Subtype (Enumtype));
1514 return;
1515 end if;
1516
1517 if Scope (Enumtype) /= Current_Scope then
1518 Error_Msg_N ("type must be declared in this scope", Ident);
1519 return;
1520
1521 elsif not Is_First_Subtype (Enumtype) then
1522 Error_Msg_N ("cannot give enumeration rep clause for subtype", N);
1523 return;
1524
1525 elsif Has_Enumeration_Rep_Clause (Enumtype) then
1526 Error_Msg_N ("duplicate enumeration rep clause ignored", N);
1527 return;
1528
1529 elsif Root_Type (Enumtype) = Standard_Character
1530 or else Root_Type (Enumtype) = Standard_Wide_Character
1531 then
1532 Error_Msg_N ("enumeration rep clause not allowed for this type", N);
1533
1534 else
1535 Set_Has_Enumeration_Rep_Clause (Enumtype);
1536 Set_Has_Enumeration_Rep_Clause (Base_Type (Enumtype));
1537 end if;
1538
1539 -- Now we process the aggregate. Note that we don't use the normal
1540 -- aggregate code for this purpose, because we don't want any of the
1541 -- normal expansion activities, and a number of special semantic
1542 -- rules apply (including the component type being any integer type)
1543
1544 -- Badent signals that we found some incorrect entries processing
1545 -- the list. The final checks for completeness and ordering are
1546 -- skipped in this case.
1547
1548 Elit := First_Literal (Enumtype);
1549
1550 -- First the positional entries if any
1551
1552 if Present (Expressions (Aggr)) then
1553 Expr := First (Expressions (Aggr));
1554 while Present (Expr) loop
1555 if No (Elit) then
1556 Error_Msg_N ("too many entries in aggregate", Expr);
1557 return;
1558 end if;
1559
1560 Val := Static_Integer (Expr);
1561
1562 if Val = No_Uint then
1563 Err := True;
1564
1565 elsif Val < Lo or else Hi < Val then
1566 Error_Msg_N ("value outside permitted range", Expr);
1567 Err := True;
1568 end if;
1569
1570 Set_Enumeration_Rep (Elit, Val);
1571 Set_Enumeration_Rep_Expr (Elit, Expr);
1572 Next (Expr);
1573 Next (Elit);
1574 end loop;
1575 end if;
1576
1577 -- Now process the named entries if present
1578
1579 if Present (Component_Associations (Aggr)) then
1580 Assoc := First (Component_Associations (Aggr));
1581 while Present (Assoc) loop
1582 Choice := First (Choices (Assoc));
1583
1584 if Present (Next (Choice)) then
1585 Error_Msg_N
1586 ("multiple choice not allowed here", Next (Choice));
1587 Err := True;
1588 end if;
1589
1590 if Nkind (Choice) = N_Others_Choice then
1591 Error_Msg_N ("others choice not allowed here", Choice);
1592 Err := True;
1593
1594 elsif Nkind (Choice) = N_Range then
1595 -- ??? should allow zero/one element range here
1596 Error_Msg_N ("range not allowed here", Choice);
1597 Err := True;
1598
1599 else
1600 Analyze_And_Resolve (Choice, Enumtype);
1601
1602 if Is_Entity_Name (Choice)
1603 and then Is_Type (Entity (Choice))
1604 then
1605 Error_Msg_N ("subtype name not allowed here", Choice);
1606 Err := True;
1607 -- ??? should allow static subtype with zero/one entry
1608
1609 elsif Etype (Choice) = Base_Type (Enumtype) then
1610 if not Is_Static_Expression (Choice) then
1611 Error_Msg_N
1612 ("non-static expression used for choice", Choice);
1613 Err := True;
1614
1615 else
1616 Elit := Expr_Value_E (Choice);
1617
1618 if Present (Enumeration_Rep_Expr (Elit)) then
1619 Error_Msg_Sloc := Sloc (Enumeration_Rep_Expr (Elit));
1620 Error_Msg_NE
1621 ("representation for& previously given#",
1622 Choice, Elit);
1623 Err := True;
1624 end if;
1625
1626 Set_Enumeration_Rep_Expr (Elit, Choice);
1627
1628 Expr := Expression (Assoc);
1629 Val := Static_Integer (Expr);
1630
1631 if Val = No_Uint then
1632 Err := True;
1633
1634 elsif Val < Lo or else Hi < Val then
1635 Error_Msg_N ("value outside permitted range", Expr);
1636 Err := True;
1637 end if;
1638
1639 Set_Enumeration_Rep (Elit, Val);
1640 end if;
1641 end if;
1642 end if;
1643
1644 Next (Assoc);
1645 end loop;
1646 end if;
1647
1648 -- Aggregate is fully processed. Now we check that a full set of
1649 -- representations was given, and that they are in range and in order.
1650 -- These checks are only done if no other errors occurred.
1651
1652 if not Err then
1653 Min := No_Uint;
1654 Max := No_Uint;
1655
1656 Elit := First_Literal (Enumtype);
1657 while Present (Elit) loop
1658 if No (Enumeration_Rep_Expr (Elit)) then
1659 Error_Msg_NE ("missing representation for&!", N, Elit);
1660
1661 else
1662 Val := Enumeration_Rep (Elit);
1663
1664 if Min = No_Uint then
1665 Min := Val;
1666 end if;
1667
1668 if Val /= No_Uint then
1669 if Max /= No_Uint and then Val <= Max then
1670 Error_Msg_NE
1671 ("enumeration value for& not ordered!",
1672 Enumeration_Rep_Expr (Elit), Elit);
1673 end if;
1674
1675 Max := Val;
1676 end if;
1677
1678 -- If there is at least one literal whose representation
1679 -- is not equal to the Pos value, then note that this
1680 -- enumeration type has a non-standard representation.
1681
1682 if Val /= Enumeration_Pos (Elit) then
1683 Set_Has_Non_Standard_Rep (Base_Type (Enumtype));
1684 end if;
1685 end if;
1686
1687 Next (Elit);
1688 end loop;
1689
1690 -- Now set proper size information
1691
1692 declare
1693 Minsize : Uint := UI_From_Int (Minimum_Size (Enumtype));
1694
1695 begin
1696 if Has_Size_Clause (Enumtype) then
1697 if Esize (Enumtype) >= Minsize then
1698 null;
1699
1700 else
1701 Minsize :=
1702 UI_From_Int (Minimum_Size (Enumtype, Biased => True));
1703
1704 if Esize (Enumtype) < Minsize then
1705 Error_Msg_N ("previously given size is too small", N);
1706
1707 else
1708 Set_Has_Biased_Representation (Enumtype);
1709 end if;
1710 end if;
1711
1712 else
1713 Set_RM_Size (Enumtype, Minsize);
1714 Set_Enum_Esize (Enumtype);
1715 end if;
1716
1717 Set_RM_Size (Base_Type (Enumtype), RM_Size (Enumtype));
1718 Set_Esize (Base_Type (Enumtype), Esize (Enumtype));
1719 Set_Alignment (Base_Type (Enumtype), Alignment (Enumtype));
1720 end;
1721 end if;
1722
1723 -- We repeat the too late test in case it froze itself!
1724
1725 if Rep_Item_Too_Late (Enumtype, N) then
1726 null;
1727 end if;
1728
1729 end Analyze_Enumeration_Representation_Clause;
1730
1731 ----------------------------
1732 -- Analyze_Free_Statement --
1733 ----------------------------
1734
1735 procedure Analyze_Free_Statement (N : Node_Id) is
1736 begin
1737 Analyze (Expression (N));
1738 end Analyze_Free_Statement;
1739
1740 ------------------------------------------
1741 -- Analyze_Record_Representation_Clause --
1742 ------------------------------------------
1743
1744 procedure Analyze_Record_Representation_Clause (N : Node_Id) is
1745 Loc : constant Source_Ptr := Sloc (N);
1746 Ident : constant Node_Id := Identifier (N);
1747 Rectype : Entity_Id;
1748 Fent : Entity_Id;
1749 CC : Node_Id;
1750 Posit : Uint;
1751 Fbit : Uint;
1752 Lbit : Uint;
1753 Hbit : Uint := Uint_0;
1754 Comp : Entity_Id;
1755 Ocomp : Entity_Id;
1756 Biased : Boolean;
1757
1758 Max_Bit_So_Far : Uint;
1759 -- Records the maximum bit position so far. If all field positoins
1760 -- are monotonically increasing, then we can skip the circuit for
1761 -- checking for overlap, since no overlap is possible.
1762
1763 Overlap_Check_Required : Boolean;
1764 -- Used to keep track of whether or not an overlap check is required
1765
1766 Ccount : Natural := 0;
1767 -- Number of component clauses in record rep clause
1768
1769 begin
1770 Find_Type (Ident);
1771 Rectype := Entity (Ident);
1772
1773 if Rectype = Any_Type
1774 or else Rep_Item_Too_Early (Rectype, N)
1775 then
1776 return;
1777 else
1778 Rectype := Underlying_Type (Rectype);
1779 end if;
1780
1781 -- First some basic error checks
1782
1783 if not Is_Record_Type (Rectype) then
1784 Error_Msg_NE
1785 ("record type required, found}", Ident, First_Subtype (Rectype));
1786 return;
1787
1788 elsif Is_Unchecked_Union (Rectype) then
1789 Error_Msg_N
1790 ("record rep clause not allowed for Unchecked_Union", N);
1791
1792 elsif Scope (Rectype) /= Current_Scope then
1793 Error_Msg_N ("type must be declared in this scope", N);
1794 return;
1795
1796 elsif not Is_First_Subtype (Rectype) then
1797 Error_Msg_N ("cannot give record rep clause for subtype", N);
1798 return;
1799
1800 elsif Has_Record_Rep_Clause (Rectype) then
1801 Error_Msg_N ("duplicate record rep clause ignored", N);
1802 return;
1803
1804 elsif Rep_Item_Too_Late (Rectype, N) then
1805 return;
1806 end if;
1807
1808 if Present (Mod_Clause (N)) then
1809 declare
1810 Loc : constant Source_Ptr := Sloc (N);
1811 M : constant Node_Id := Mod_Clause (N);
1812 P : constant List_Id := Pragmas_Before (M);
1813 Mod_Val : Uint;
1814 AtM_Nod : Node_Id;
1815
1816 begin
1817 if Present (P) then
1818 Analyze_List (P);
1819 end if;
1820
1821 -- In Tree_Output mode, expansion is disabled, but we must
1822 -- convert the Mod clause into an alignment clause anyway, so
1823 -- that the back-end can compute and back-annotate properly the
1824 -- size and alignment of types that may include this record.
1825
1826 if Operating_Mode = Check_Semantics
1827 and then Tree_Output
1828 then
1829 AtM_Nod :=
1830 Make_Attribute_Definition_Clause (Loc,
1831 Name => New_Reference_To (Base_Type (Rectype), Loc),
1832 Chars => Name_Alignment,
1833 Expression => Relocate_Node (Expression (M)));
1834
1835 Set_From_At_Mod (AtM_Nod);
1836 Insert_After (N, AtM_Nod);
1837 Mod_Val := Get_Alignment_Value (Expression (AtM_Nod));
1838 Set_Mod_Clause (N, Empty);
1839
1840 else
1841 -- Get the alignment value to perform error checking
1842
1843 Mod_Val := Get_Alignment_Value (Expression (M));
1844
1845 end if;
1846 end;
1847 end if;
1848
1849 -- Clear any existing component clauses for the type (this happens
1850 -- with derived types, where we are now overriding the original)
1851
1852 Fent := First_Entity (Rectype);
1853
1854 Comp := Fent;
1855 while Present (Comp) loop
1856 if Ekind (Comp) = E_Component
1857 or else Ekind (Comp) = E_Discriminant
1858 then
1859 Set_Component_Clause (Comp, Empty);
1860 end if;
1861
1862 Next_Entity (Comp);
1863 end loop;
1864
1865 -- All done if no component clauses
1866
1867 CC := First (Component_Clauses (N));
1868
1869 if No (CC) then
1870 return;
1871 end if;
1872
1873 -- If a tag is present, then create a component clause that places
1874 -- it at the start of the record (otherwise gigi may place it after
1875 -- other fields that have rep clauses).
1876
1877 if Nkind (Fent) = N_Defining_Identifier
1878 and then Chars (Fent) = Name_uTag
1879 then
1880 Set_Component_Bit_Offset (Fent, Uint_0);
1881 Set_Normalized_Position (Fent, Uint_0);
1882 Set_Normalized_First_Bit (Fent, Uint_0);
1883 Set_Normalized_Position_Max (Fent, Uint_0);
1884 Init_Esize (Fent, System_Address_Size);
1885
1886 Set_Component_Clause (Fent,
1887 Make_Component_Clause (Loc,
1888 Component_Name =>
1889 Make_Identifier (Loc,
1890 Chars => Name_uTag),
1891
1892 Position =>
1893 Make_Integer_Literal (Loc,
1894 Intval => Uint_0),
1895
1896 First_Bit =>
1897 Make_Integer_Literal (Loc,
1898 Intval => Uint_0),
1899
1900 Last_Bit =>
1901 Make_Integer_Literal (Loc,
1902 UI_From_Int (System_Address_Size))));
1903
1904 Ccount := Ccount + 1;
1905 end if;
1906
1907 -- A representation like this applies to the base type
1908
1909 Set_Has_Record_Rep_Clause (Base_Type (Rectype));
1910 Set_Has_Non_Standard_Rep (Base_Type (Rectype));
1911 Set_Has_Specified_Layout (Base_Type (Rectype));
1912
1913 Max_Bit_So_Far := Uint_Minus_1;
1914 Overlap_Check_Required := False;
1915
1916 -- Process the component clauses
1917
1918 while Present (CC) loop
1919
1920 -- If pragma, just analyze it
1921
1922 if Nkind (CC) = N_Pragma then
1923 Analyze (CC);
1924
1925 -- Processing for real component clause
1926
1927 else
1928 Ccount := Ccount + 1;
1929 Posit := Static_Integer (Position (CC));
1930 Fbit := Static_Integer (First_Bit (CC));
1931 Lbit := Static_Integer (Last_Bit (CC));
1932
1933 if Posit /= No_Uint
1934 and then Fbit /= No_Uint
1935 and then Lbit /= No_Uint
1936 then
1937 if Posit < 0 then
1938 Error_Msg_N
1939 ("position cannot be negative", Position (CC));
1940
1941 elsif Fbit < 0 then
1942 Error_Msg_N
1943 ("first bit cannot be negative", First_Bit (CC));
1944
1945 -- Values look OK, so find the corresponding record component
1946 -- Even though the syntax allows an attribute reference for
1947 -- implementation-defined components, GNAT does not allow the
1948 -- tag to get an explicit position.
1949
1950 elsif Nkind (Component_Name (CC)) = N_Attribute_Reference then
1951
1952 if Attribute_Name (Component_Name (CC)) = Name_Tag then
1953 Error_Msg_N ("position of tag cannot be specified", CC);
1954 else
1955 Error_Msg_N ("illegal component name", CC);
1956 end if;
1957
1958 else
1959 Comp := First_Entity (Rectype);
1960 while Present (Comp) loop
1961 exit when Chars (Comp) = Chars (Component_Name (CC));
1962 Next_Entity (Comp);
1963 end loop;
1964
1965 if No (Comp) then
1966
1967 -- Maybe component of base type that is absent from
1968 -- statically constrained first subtype.
1969
1970 Comp := First_Entity (Base_Type (Rectype));
1971 while Present (Comp) loop
1972 exit when Chars (Comp) = Chars (Component_Name (CC));
1973 Next_Entity (Comp);
1974 end loop;
1975 end if;
1976
1977 if No (Comp) then
1978 Error_Msg_N
1979 ("component clause is for non-existent field", CC);
1980
1981 elsif Present (Component_Clause (Comp)) then
1982 Error_Msg_Sloc := Sloc (Component_Clause (Comp));
1983 Error_Msg_N
1984 ("component clause previously given#", CC);
1985
1986 else
1987 -- Update Fbit and Lbit to the actual bit number.
1988
1989 Fbit := Fbit + UI_From_Int (SSU) * Posit;
1990 Lbit := Lbit + UI_From_Int (SSU) * Posit;
1991
1992 if Fbit <= Max_Bit_So_Far then
1993 Overlap_Check_Required := True;
1994 else
1995 Max_Bit_So_Far := Lbit;
1996 end if;
1997
1998 if Has_Size_Clause (Rectype)
1999 and then Esize (Rectype) <= Lbit
2000 then
2001 Error_Msg_N
2002 ("bit number out of range of specified size",
2003 Last_Bit (CC));
2004 else
2005 Set_Component_Clause (Comp, CC);
2006 Set_Component_Bit_Offset (Comp, Fbit);
2007 Set_Esize (Comp, 1 + (Lbit - Fbit));
2008 Set_Normalized_First_Bit (Comp, Fbit mod SSU);
2009 Set_Normalized_Position (Comp, Fbit / SSU);
2010
2011 Set_Normalized_Position_Max
2012 (Fent, Normalized_Position (Fent));
2013
2014 if Is_Tagged_Type (Rectype)
2015 and then Fbit < System_Address_Size
2016 then
2017 Error_Msg_NE
2018 ("component overlaps tag field of&",
2019 CC, Rectype);
2020 end if;
2021
2022 -- Test for large object that is not on a byte
2023 -- boundary, defined as a large packed array not
2024 -- represented by a modular type, or an object for
2025 -- which a size of greater than 64 bits is specified.
2026
2027 if Fbit mod SSU /= 0 then
2028 if (Is_Packed_Array_Type (Etype (Comp))
2029 and then Is_Array_Type
2030 (Packed_Array_Type (Etype (Comp))))
2031 or else Esize (Etype (Comp)) > 64
2032 then
2033 Error_Msg_N
2034 ("large component must be on byte boundary",
2035 First_Bit (CC));
2036 end if;
2037 end if;
2038
2039 -- This information is also set in the
2040 -- corresponding component of the base type,
2041 -- found by accessing the Original_Record_Component
2042 -- link if it is present.
2043
2044 Ocomp := Original_Record_Component (Comp);
2045
2046 if Hbit < Lbit then
2047 Hbit := Lbit;
2048 end if;
2049
2050 Check_Size
2051 (Component_Name (CC),
2052 Etype (Comp),
2053 Esize (Comp),
2054 Biased);
2055
2056 Set_Has_Biased_Representation (Comp, Biased);
2057
2058 if Present (Ocomp) then
2059 Set_Component_Clause (Ocomp, CC);
2060 Set_Component_Bit_Offset (Ocomp, Fbit);
2061 Set_Normalized_First_Bit (Ocomp, Fbit mod SSU);
2062 Set_Normalized_Position (Ocomp, Fbit / SSU);
2063 Set_Esize (Ocomp, 1 + (Lbit - Fbit));
2064
2065 Set_Normalized_Position_Max
2066 (Ocomp, Normalized_Position (Ocomp));
2067
2068 Set_Has_Biased_Representation
2069 (Ocomp, Has_Biased_Representation (Comp));
2070 end if;
2071
2072 if Esize (Comp) < 0 then
2073 Error_Msg_N ("component size is negative", CC);
2074 end if;
2075 end if;
2076 end if;
2077 end if;
2078 end if;
2079 end if;
2080
2081 Next (CC);
2082 end loop;
2083
2084 -- Now that we have processed all the component clauses, check for
2085 -- overlap. We have to leave this till last, since the components
2086 -- can appear in any arbitrary order in the representation clause.
2087
2088 -- We do not need this check if all specified ranges were monotonic,
2089 -- as recorded by Overlap_Check_Required being False at this stage.
2090
2091 -- This first section checks if there are any overlapping entries
2092 -- at all. It does this by sorting all entries and then seeing if
2093 -- there are any overlaps. If there are none, then that is decisive,
2094 -- but if there are overlaps, they may still be OK (they may result
2095 -- from fields in different variants).
2096
2097 if Overlap_Check_Required then
2098 Overlap_Check1 : declare
2099
2100 OC_Fbit : array (0 .. Ccount) of Uint;
2101 -- First-bit values for component clauses, the value is the
2102 -- offset of the first bit of the field from start of record.
2103 -- The zero entry is for use in sorting.
2104
2105 OC_Lbit : array (0 .. Ccount) of Uint;
2106 -- Last-bit values for component clauses, the value is the
2107 -- offset of the last bit of the field from start of record.
2108 -- The zero entry is for use in sorting.
2109
2110 OC_Count : Natural := 0;
2111 -- Count of entries in OC_Fbit and OC_Lbit
2112
2113 function OC_Lt (Op1, Op2 : Natural) return Boolean;
2114 -- Compare routine for Sort (See GNAT.Heap_Sort_A)
2115
2116 procedure OC_Move (From : Natural; To : Natural);
2117 -- Move routine for Sort (see GNAT.Heap_Sort_A)
2118
2119 function OC_Lt (Op1, Op2 : Natural) return Boolean is
2120 begin
2121 return OC_Fbit (Op1) < OC_Fbit (Op2);
2122 end OC_Lt;
2123
2124 procedure OC_Move (From : Natural; To : Natural) is
2125 begin
2126 OC_Fbit (To) := OC_Fbit (From);
2127 OC_Lbit (To) := OC_Lbit (From);
2128 end OC_Move;
2129
2130 begin
2131 CC := First (Component_Clauses (N));
2132 while Present (CC) loop
2133 if Nkind (CC) /= N_Pragma then
2134 Posit := Static_Integer (Position (CC));
2135 Fbit := Static_Integer (First_Bit (CC));
2136 Lbit := Static_Integer (Last_Bit (CC));
2137
2138 if Posit /= No_Uint
2139 and then Fbit /= No_Uint
2140 and then Lbit /= No_Uint
2141 then
2142 OC_Count := OC_Count + 1;
2143 Posit := Posit * SSU;
2144 OC_Fbit (OC_Count) := Fbit + Posit;
2145 OC_Lbit (OC_Count) := Lbit + Posit;
2146 end if;
2147 end if;
2148
2149 Next (CC);
2150 end loop;
2151
2152 Sort
2153 (OC_Count,
2154 OC_Move'Unrestricted_Access,
2155 OC_Lt'Unrestricted_Access);
2156
2157 Overlap_Check_Required := False;
2158 for J in 1 .. OC_Count - 1 loop
2159 if OC_Lbit (J) >= OC_Fbit (J + 1) then
2160 Overlap_Check_Required := True;
2161 exit;
2162 end if;
2163 end loop;
2164 end Overlap_Check1;
2165 end if;
2166
2167 -- If Overlap_Check_Required is still True, then we have to do
2168 -- the full scale overlap check, since we have at least two fields
2169 -- that do overlap, and we need to know if that is OK since they
2170 -- are in the same variant, or whether we have a definite problem
2171
2172 if Overlap_Check_Required then
2173 Overlap_Check2 : declare
2174 C1_Ent, C2_Ent : Entity_Id;
2175 -- Entities of components being checked for overlap
2176
2177 Clist : Node_Id;
2178 -- Component_List node whose Component_Items are being checked
2179
2180 Citem : Node_Id;
2181 -- Component declaration for component being checked
2182
2183 begin
2184 C1_Ent := First_Entity (Base_Type (Rectype));
2185
2186 -- Loop through all components in record. For each component check
2187 -- for overlap with any of the preceding elements on the component
2188 -- list containing the component, and also, if the component is in
2189 -- a variant, check against components outside the case structure.
2190 -- This latter test is repeated recursively up the variant tree.
2191
2192 Main_Component_Loop : while Present (C1_Ent) loop
2193 if Ekind (C1_Ent) /= E_Component
2194 and then Ekind (C1_Ent) /= E_Discriminant
2195 then
2196 goto Continue_Main_Component_Loop;
2197 end if;
2198
2199 -- Skip overlap check if entity has no declaration node. This
2200 -- happens with discriminants in constrained derived types.
2201 -- Probably we are missing some checks as a result, but that
2202 -- does not seem terribly serious ???
2203
2204 if No (Declaration_Node (C1_Ent)) then
2205 goto Continue_Main_Component_Loop;
2206 end if;
2207
2208 Clist := Parent (List_Containing (Declaration_Node (C1_Ent)));
2209
2210 -- Loop through component lists that need checking. Check the
2211 -- current component list and all lists in variants above us.
2212
2213 Component_List_Loop : loop
2214
2215 -- If derived type definition, go to full declaration
2216 -- If at outer level, check discriminants if there are any
2217
2218 if Nkind (Clist) = N_Derived_Type_Definition then
2219 Clist := Parent (Clist);
2220 end if;
2221
2222 -- Outer level of record definition, check discriminants
2223
2224 if Nkind (Clist) = N_Full_Type_Declaration
2225 or else Nkind (Clist) = N_Private_Type_Declaration
2226 then
2227 if Has_Discriminants (Defining_Identifier (Clist)) then
2228 C2_Ent :=
2229 First_Discriminant (Defining_Identifier (Clist));
2230
2231 while Present (C2_Ent) loop
2232 exit when C1_Ent = C2_Ent;
2233 Check_Component_Overlap (C1_Ent, C2_Ent);
2234 Next_Discriminant (C2_Ent);
2235 end loop;
2236 end if;
2237
2238 -- Record extension case
2239
2240 elsif Nkind (Clist) = N_Derived_Type_Definition then
2241 Clist := Empty;
2242
2243 -- Otherwise check one component list
2244
2245 else
2246 Citem := First (Component_Items (Clist));
2247
2248 while Present (Citem) loop
2249 if Nkind (Citem) = N_Component_Declaration then
2250 C2_Ent := Defining_Identifier (Citem);
2251 exit when C1_Ent = C2_Ent;
2252 Check_Component_Overlap (C1_Ent, C2_Ent);
2253 end if;
2254
2255 Next (Citem);
2256 end loop;
2257 end if;
2258
2259 -- Check for variants above us (the parent of the Clist can
2260 -- be a variant, in which case its parent is a variant part,
2261 -- and the parent of the variant part is a component list
2262 -- whose components must all be checked against the current
2263 -- component for overlap.
2264
2265 if Nkind (Parent (Clist)) = N_Variant then
2266 Clist := Parent (Parent (Parent (Clist)));
2267
2268 -- Check for possible discriminant part in record, this is
2269 -- treated essentially as another level in the recursion.
2270 -- For this case we have the parent of the component list
2271 -- is the record definition, and its parent is the full
2272 -- type declaration which contains the discriminant
2273 -- specifications.
2274
2275 elsif Nkind (Parent (Clist)) = N_Record_Definition then
2276 Clist := Parent (Parent ((Clist)));
2277
2278 -- If neither of these two cases, we are at the top of
2279 -- the tree
2280
2281 else
2282 exit Component_List_Loop;
2283 end if;
2284 end loop Component_List_Loop;
2285
2286 <<Continue_Main_Component_Loop>>
2287 Next_Entity (C1_Ent);
2288
2289 end loop Main_Component_Loop;
2290 end Overlap_Check2;
2291 end if;
2292
2293 -- For records that have component clauses for all components, and
2294 -- whose size is less than or equal to 32, we need to know the size
2295 -- in the front end to activate possible packed array processing
2296 -- where the component type is a record.
2297
2298 -- At this stage Hbit + 1 represents the first unused bit from all
2299 -- the component clauses processed, so if the component clauses are
2300 -- complete, then this is the length of the record.
2301
2302 -- For records longer than System.Storage_Unit, and for those where
2303 -- not all components have component clauses, the back end determines
2304 -- the length (it may for example be appopriate to round up the size
2305 -- to some convenient boundary, based on alignment considerations etc).
2306
2307 if Unknown_RM_Size (Rectype)
2308 and then Hbit + 1 <= 32
2309 then
2310 -- Nothing to do if at least one component with no component clause
2311
2312 Comp := First_Entity (Rectype);
2313 while Present (Comp) loop
2314 if Ekind (Comp) = E_Component
2315 or else Ekind (Comp) = E_Discriminant
2316 then
2317 if No (Component_Clause (Comp)) then
2318 return;
2319 end if;
2320 end if;
2321
2322 Next_Entity (Comp);
2323 end loop;
2324
2325 -- If we fall out of loop, all components have component clauses
2326 -- and so we can set the size to the maximum value.
2327
2328 Set_RM_Size (Rectype, Hbit + 1);
2329 end if;
2330
2331 end Analyze_Record_Representation_Clause;
2332
2333 -----------------------------
2334 -- Check_Component_Overlap --
2335 -----------------------------
2336
2337 procedure Check_Component_Overlap (C1_Ent, C2_Ent : Entity_Id) is
2338 begin
2339 if Present (Component_Clause (C1_Ent))
2340 and then Present (Component_Clause (C2_Ent))
2341 then
2342 -- Exclude odd case where we have two tag fields in the same
2343 -- record, both at location zero. This seems a bit strange,
2344 -- but it seems to happen in some circumstances ???
2345
2346 if Chars (C1_Ent) = Name_uTag
2347 and then Chars (C2_Ent) = Name_uTag
2348 then
2349 return;
2350 end if;
2351
2352 -- Here we check if the two fields overlap
2353
2354 declare
2355 S1 : constant Uint := Component_Bit_Offset (C1_Ent);
2356 S2 : constant Uint := Component_Bit_Offset (C2_Ent);
2357 E1 : constant Uint := S1 + Esize (C1_Ent);
2358 E2 : constant Uint := S2 + Esize (C2_Ent);
2359
2360 begin
2361 if E2 <= S1 or else E1 <= S2 then
2362 null;
2363 else
2364 Error_Msg_Node_2 :=
2365 Component_Name (Component_Clause (C2_Ent));
2366 Error_Msg_Sloc := Sloc (Error_Msg_Node_2);
2367 Error_Msg_Node_1 :=
2368 Component_Name (Component_Clause (C1_Ent));
2369 Error_Msg_N
2370 ("component& overlaps & #",
2371 Component_Name (Component_Clause (C1_Ent)));
2372 end if;
2373 end;
2374 end if;
2375 end Check_Component_Overlap;
2376
2377 -----------------------------------
2378 -- Check_Constant_Address_Clause --
2379 -----------------------------------
2380
2381 procedure Check_Constant_Address_Clause
2382 (Expr : Node_Id;
2383 U_Ent : Entity_Id)
2384 is
2385 procedure Check_At_Constant_Address (Nod : Node_Id);
2386 -- Checks that the given node N represents a name whose 'Address
2387 -- is constant (in the same sense as OK_Constant_Address_Clause,
2388 -- i.e. the address value is the same at the point of declaration
2389 -- of U_Ent and at the time of elaboration of the address clause.
2390
2391 procedure Check_Expr_Constants (Nod : Node_Id);
2392 -- Checks that Nod meets the requirements for a constant address
2393 -- clause in the sense of the enclosing procedure.
2394
2395 procedure Check_List_Constants (Lst : List_Id);
2396 -- Check that all elements of list Lst meet the requirements for a
2397 -- constant address clause in the sense of the enclosing procedure.
2398
2399 -------------------------------
2400 -- Check_At_Constant_Address --
2401 -------------------------------
2402
2403 procedure Check_At_Constant_Address (Nod : Node_Id) is
2404 begin
2405 if Is_Entity_Name (Nod) then
2406 if Present (Address_Clause (Entity ((Nod)))) then
2407 Error_Msg_NE
2408 ("invalid address clause for initialized object &!",
2409 Nod, U_Ent);
2410 Error_Msg_NE
2411 ("address for& cannot" &
2412 " depend on another address clause! ('R'M 13.1(22))!",
2413 Nod, U_Ent);
2414
2415 elsif In_Same_Source_Unit (Entity (Nod), U_Ent)
2416 and then Sloc (U_Ent) < Sloc (Entity (Nod))
2417 then
2418 Error_Msg_NE
2419 ("invalid address clause for initialized object &!",
2420 Nod, U_Ent);
2421 Error_Msg_Name_1 := Chars (Entity (Nod));
2422 Error_Msg_Name_2 := Chars (U_Ent);
2423 Error_Msg_N
2424 ("\% must be defined before % ('R'M 13.1(22))!",
2425 Nod);
2426 end if;
2427
2428 elsif Nkind (Nod) = N_Selected_Component then
2429 declare
2430 T : constant Entity_Id := Etype (Prefix (Nod));
2431
2432 begin
2433 if (Is_Record_Type (T)
2434 and then Has_Discriminants (T))
2435 or else
2436 (Is_Access_Type (T)
2437 and then Is_Record_Type (Designated_Type (T))
2438 and then Has_Discriminants (Designated_Type (T)))
2439 then
2440 Error_Msg_NE
2441 ("invalid address clause for initialized object &!",
2442 Nod, U_Ent);
2443 Error_Msg_N
2444 ("\address cannot depend on component" &
2445 " of discriminated record ('R'M 13.1(22))!",
2446 Nod);
2447 else
2448 Check_At_Constant_Address (Prefix (Nod));
2449 end if;
2450 end;
2451
2452 elsif Nkind (Nod) = N_Indexed_Component then
2453 Check_At_Constant_Address (Prefix (Nod));
2454 Check_List_Constants (Expressions (Nod));
2455
2456 else
2457 Check_Expr_Constants (Nod);
2458 end if;
2459 end Check_At_Constant_Address;
2460
2461 --------------------------
2462 -- Check_Expr_Constants --
2463 --------------------------
2464
2465 procedure Check_Expr_Constants (Nod : Node_Id) is
2466 begin
2467 if Nkind (Nod) in N_Has_Etype
2468 and then Etype (Nod) = Any_Type
2469 then
2470 return;
2471 end if;
2472
2473 case Nkind (Nod) is
2474 when N_Empty | N_Error =>
2475 return;
2476
2477 when N_Identifier | N_Expanded_Name =>
2478 declare
2479 Ent : constant Entity_Id := Entity (Nod);
2480 Loc_Ent : constant Source_Ptr := Sloc (Ent);
2481 Loc_U_Ent : constant Source_Ptr := Sloc (U_Ent);
2482
2483 begin
2484 if Ekind (Ent) = E_Named_Integer
2485 or else
2486 Ekind (Ent) = E_Named_Real
2487 or else
2488 Is_Type (Ent)
2489 then
2490 return;
2491
2492 elsif
2493 Ekind (Ent) = E_Constant
2494 or else
2495 Ekind (Ent) = E_In_Parameter
2496 then
2497 -- This is the case where we must have Ent defined
2498 -- before U_Ent. Clearly if they are in different
2499 -- units this requirement is met since the unit
2500 -- containing Ent is already processed.
2501
2502 if not In_Same_Source_Unit (Ent, U_Ent) then
2503 return;
2504
2505 -- Otherwise location of Ent must be before the
2506 -- location of U_Ent, that's what prior defined means.
2507
2508 elsif Loc_Ent < Loc_U_Ent then
2509 return;
2510
2511 else
2512 Error_Msg_NE
2513 ("invalid address clause for initialized object &!",
2514 Nod, U_Ent);
2515 Error_Msg_Name_1 := Chars (Ent);
2516 Error_Msg_Name_2 := Chars (U_Ent);
2517 Error_Msg_N
2518 ("\% must be defined before % ('R'M 13.1(22))!",
2519 Nod);
2520 end if;
2521
2522 elsif Nkind (Original_Node (Nod)) = N_Function_Call then
2523 Check_Expr_Constants (Original_Node (Nod));
2524
2525 else
2526 Error_Msg_NE
2527 ("invalid address clause for initialized object &!",
2528 Nod, U_Ent);
2529 Error_Msg_Name_1 := Chars (Ent);
2530 Error_Msg_N
2531 ("\reference to variable% not allowed ('R'M 13.1(22))!",
2532 Nod);
2533 end if;
2534 end;
2535
2536 when N_Integer_Literal |
2537 N_Real_Literal |
2538 N_String_Literal |
2539 N_Character_Literal =>
2540 return;
2541
2542 when N_Range =>
2543 Check_Expr_Constants (Low_Bound (Nod));
2544 Check_Expr_Constants (High_Bound (Nod));
2545
2546 when N_Explicit_Dereference =>
2547 Check_Expr_Constants (Prefix (Nod));
2548
2549 when N_Indexed_Component =>
2550 Check_Expr_Constants (Prefix (Nod));
2551 Check_List_Constants (Expressions (Nod));
2552
2553 when N_Slice =>
2554 Check_Expr_Constants (Prefix (Nod));
2555 Check_Expr_Constants (Discrete_Range (Nod));
2556
2557 when N_Selected_Component =>
2558 Check_Expr_Constants (Prefix (Nod));
2559
2560 when N_Attribute_Reference =>
2561
2562 if (Attribute_Name (Nod) = Name_Address
2563 or else
2564 Attribute_Name (Nod) = Name_Access
2565 or else
2566 Attribute_Name (Nod) = Name_Unchecked_Access
2567 or else
2568 Attribute_Name (Nod) = Name_Unrestricted_Access)
2569 then
2570 Check_At_Constant_Address (Prefix (Nod));
2571
2572 else
2573 Check_Expr_Constants (Prefix (Nod));
2574 Check_List_Constants (Expressions (Nod));
2575 end if;
2576
2577 when N_Aggregate =>
2578 Check_List_Constants (Component_Associations (Nod));
2579 Check_List_Constants (Expressions (Nod));
2580
2581 when N_Component_Association =>
2582 Check_Expr_Constants (Expression (Nod));
2583
2584 when N_Extension_Aggregate =>
2585 Check_Expr_Constants (Ancestor_Part (Nod));
2586 Check_List_Constants (Component_Associations (Nod));
2587 Check_List_Constants (Expressions (Nod));
2588
2589 when N_Null =>
2590 return;
2591
2592 when N_Binary_Op | N_And_Then | N_Or_Else | N_In | N_Not_In =>
2593 Check_Expr_Constants (Left_Opnd (Nod));
2594 Check_Expr_Constants (Right_Opnd (Nod));
2595
2596 when N_Unary_Op =>
2597 Check_Expr_Constants (Right_Opnd (Nod));
2598
2599 when N_Type_Conversion |
2600 N_Qualified_Expression |
2601 N_Allocator =>
2602 Check_Expr_Constants (Expression (Nod));
2603
2604 when N_Unchecked_Type_Conversion =>
2605 Check_Expr_Constants (Expression (Nod));
2606
2607 -- If this is a rewritten unchecked conversion, subtypes
2608 -- in this node are those created within the instance.
2609 -- To avoid order of elaboration issues, replace them
2610 -- with their base types. Note that address clauses can
2611 -- cause order of elaboration problems because they are
2612 -- elaborated by the back-end at the point of definition,
2613 -- and may mention entities declared in between (as long
2614 -- as everything is static). It is user-friendly to allow
2615 -- unchecked conversions in this context.
2616
2617 if Nkind (Original_Node (Nod)) = N_Function_Call then
2618 Set_Etype (Expression (Nod),
2619 Base_Type (Etype (Expression (Nod))));
2620 Set_Etype (Nod, Base_Type (Etype (Nod)));
2621 end if;
2622
2623 when N_Function_Call =>
2624 if not Is_Pure (Entity (Name (Nod))) then
2625 Error_Msg_NE
2626 ("invalid address clause for initialized object &!",
2627 Nod, U_Ent);
2628
2629 Error_Msg_NE
2630 ("\function & is not pure ('R'M 13.1(22))!",
2631 Nod, Entity (Name (Nod)));
2632
2633 else
2634 Check_List_Constants (Parameter_Associations (Nod));
2635 end if;
2636
2637 when N_Parameter_Association =>
2638 Check_Expr_Constants (Explicit_Actual_Parameter (Nod));
2639
2640 when others =>
2641 Error_Msg_NE
2642 ("invalid address clause for initialized object &!",
2643 Nod, U_Ent);
2644 Error_Msg_NE
2645 ("\must be constant defined before& ('R'M 13.1(22))!",
2646 Nod, U_Ent);
2647 end case;
2648 end Check_Expr_Constants;
2649
2650 --------------------------
2651 -- Check_List_Constants --
2652 --------------------------
2653
2654 procedure Check_List_Constants (Lst : List_Id) is
2655 Nod1 : Node_Id;
2656
2657 begin
2658 if Present (Lst) then
2659 Nod1 := First (Lst);
2660 while Present (Nod1) loop
2661 Check_Expr_Constants (Nod1);
2662 Next (Nod1);
2663 end loop;
2664 end if;
2665 end Check_List_Constants;
2666
2667 -- Start of processing for Check_Constant_Address_Clause
2668
2669 begin
2670 Check_Expr_Constants (Expr);
2671 end Check_Constant_Address_Clause;
2672
2673 ----------------
2674 -- Check_Size --
2675 ----------------
2676
2677 procedure Check_Size
2678 (N : Node_Id;
2679 T : Entity_Id;
2680 Siz : Uint;
2681 Biased : out Boolean)
2682 is
2683 UT : constant Entity_Id := Underlying_Type (T);
2684 M : Uint;
2685
2686 begin
2687 Biased := False;
2688
2689 -- Immediate return if size is same as standard size or if composite
2690 -- item, or generic type, or type with previous errors.
2691
2692 if No (UT)
2693 or else UT = Any_Type
2694 or else Is_Generic_Type (UT)
2695 or else Is_Generic_Type (Root_Type (UT))
2696 or else Is_Composite_Type (UT)
2697 or else (Known_Esize (UT) and then Siz = Esize (UT))
2698 then
2699 return;
2700
2701 -- For fixed-point types, don't check minimum if type is not frozen,
2702 -- since type is not known till then
2703 -- at freeze time.
2704
2705 elsif Is_Fixed_Point_Type (UT)
2706 and then not Is_Frozen (UT)
2707 then
2708 null;
2709
2710 -- Cases for which a minimum check is required
2711
2712 else
2713 M := UI_From_Int (Minimum_Size (UT));
2714
2715 if Siz < M then
2716
2717 -- Size is less than minimum size, but one possibility remains
2718 -- that we can manage with the new size if we bias the type
2719
2720 M := UI_From_Int (Minimum_Size (UT, Biased => True));
2721
2722 if Siz < M then
2723 Error_Msg_Uint_1 := M;
2724 Error_Msg_NE
2725 ("size for& too small, minimum allowed is ^", N, T);
2726 else
2727 Biased := True;
2728 end if;
2729 end if;
2730 end if;
2731 end Check_Size;
2732
2733 -------------------------
2734 -- Get_Alignment_Value --
2735 -------------------------
2736
2737 function Get_Alignment_Value (Expr : Node_Id) return Uint is
2738 Align : constant Uint := Static_Integer (Expr);
2739
2740 begin
2741 if Align = No_Uint then
2742 return No_Uint;
2743
2744 elsif Align <= 0 then
2745 Error_Msg_N ("alignment value must be positive", Expr);
2746 return No_Uint;
2747
2748 else
2749 for J in Int range 0 .. 64 loop
2750 declare
2751 M : constant Uint := Uint_2 ** J;
2752
2753 begin
2754 exit when M = Align;
2755
2756 if M > Align then
2757 Error_Msg_N
2758 ("alignment value must be power of 2", Expr);
2759 return No_Uint;
2760 end if;
2761 end;
2762 end loop;
2763
2764 return Align;
2765 end if;
2766 end Get_Alignment_Value;
2767
2768 ----------------
2769 -- Initialize --
2770 ----------------
2771
2772 procedure Initialize is
2773 begin
2774 Unchecked_Conversions.Init;
2775 end Initialize;
2776
2777 -------------------------
2778 -- Is_Operational_Item --
2779 -------------------------
2780
2781 function Is_Operational_Item (N : Node_Id) return Boolean is
2782 begin
2783 if Nkind (N) /= N_Attribute_Definition_Clause then
2784 return False;
2785 else
2786 declare
2787 Id : constant Attribute_Id := Get_Attribute_Id (Chars (N));
2788
2789 begin
2790 return Id = Attribute_Input
2791 or else Id = Attribute_Output
2792 or else Id = Attribute_Read
2793 or else Id = Attribute_Write
2794 or else Id = Attribute_External_Tag;
2795 end;
2796 end if;
2797 end Is_Operational_Item;
2798
2799 ------------------
2800 -- Minimum_Size --
2801 ------------------
2802
2803 function Minimum_Size
2804 (T : Entity_Id;
2805 Biased : Boolean := False)
2806 return Nat
2807 is
2808 Lo : Uint := No_Uint;
2809 Hi : Uint := No_Uint;
2810 LoR : Ureal := No_Ureal;
2811 HiR : Ureal := No_Ureal;
2812 LoSet : Boolean := False;
2813 HiSet : Boolean := False;
2814 B : Uint;
2815 S : Nat;
2816 Ancest : Entity_Id;
2817 R_Typ : constant Entity_Id := Root_Type (T);
2818
2819 begin
2820 -- If bad type, return 0
2821
2822 if T = Any_Type then
2823 return 0;
2824
2825 -- For generic types, just return zero. There cannot be any legitimate
2826 -- need to know such a size, but this routine may be called with a
2827 -- generic type as part of normal processing.
2828
2829 elsif Is_Generic_Type (R_Typ)
2830 or else R_Typ = Any_Type
2831 then
2832 return 0;
2833
2834 -- Access types
2835
2836 elsif Is_Access_Type (T) then
2837 return System_Address_Size;
2838
2839 -- Floating-point types
2840
2841 elsif Is_Floating_Point_Type (T) then
2842 return UI_To_Int (Esize (R_Typ));
2843
2844 -- Discrete types
2845
2846 elsif Is_Discrete_Type (T) then
2847
2848 -- The following loop is looking for the nearest compile time
2849 -- known bounds following the ancestor subtype chain. The idea
2850 -- is to find the most restrictive known bounds information.
2851
2852 Ancest := T;
2853 loop
2854 if Ancest = Any_Type or else Etype (Ancest) = Any_Type then
2855 return 0;
2856 end if;
2857
2858 if not LoSet then
2859 if Compile_Time_Known_Value (Type_Low_Bound (Ancest)) then
2860 Lo := Expr_Rep_Value (Type_Low_Bound (Ancest));
2861 LoSet := True;
2862 exit when HiSet;
2863 end if;
2864 end if;
2865
2866 if not HiSet then
2867 if Compile_Time_Known_Value (Type_High_Bound (Ancest)) then
2868 Hi := Expr_Rep_Value (Type_High_Bound (Ancest));
2869 HiSet := True;
2870 exit when LoSet;
2871 end if;
2872 end if;
2873
2874 Ancest := Ancestor_Subtype (Ancest);
2875
2876 if No (Ancest) then
2877 Ancest := Base_Type (T);
2878
2879 if Is_Generic_Type (Ancest) then
2880 return 0;
2881 end if;
2882 end if;
2883 end loop;
2884
2885 -- Fixed-point types. We can't simply use Expr_Value to get the
2886 -- Corresponding_Integer_Value values of the bounds, since these
2887 -- do not get set till the type is frozen, and this routine can
2888 -- be called before the type is frozen. Similarly the test for
2889 -- bounds being static needs to include the case where we have
2890 -- unanalyzed real literals for the same reason.
2891
2892 elsif Is_Fixed_Point_Type (T) then
2893
2894 -- The following loop is looking for the nearest compile time
2895 -- known bounds following the ancestor subtype chain. The idea
2896 -- is to find the most restrictive known bounds information.
2897
2898 Ancest := T;
2899 loop
2900 if Ancest = Any_Type or else Etype (Ancest) = Any_Type then
2901 return 0;
2902 end if;
2903
2904 if not LoSet then
2905 if Nkind (Type_Low_Bound (Ancest)) = N_Real_Literal
2906 or else Compile_Time_Known_Value (Type_Low_Bound (Ancest))
2907 then
2908 LoR := Expr_Value_R (Type_Low_Bound (Ancest));
2909 LoSet := True;
2910 exit when HiSet;
2911 end if;
2912 end if;
2913
2914 if not HiSet then
2915 if Nkind (Type_High_Bound (Ancest)) = N_Real_Literal
2916 or else Compile_Time_Known_Value (Type_High_Bound (Ancest))
2917 then
2918 HiR := Expr_Value_R (Type_High_Bound (Ancest));
2919 HiSet := True;
2920 exit when LoSet;
2921 end if;
2922 end if;
2923
2924 Ancest := Ancestor_Subtype (Ancest);
2925
2926 if No (Ancest) then
2927 Ancest := Base_Type (T);
2928
2929 if Is_Generic_Type (Ancest) then
2930 return 0;
2931 end if;
2932 end if;
2933 end loop;
2934
2935 Lo := UR_To_Uint (LoR / Small_Value (T));
2936 Hi := UR_To_Uint (HiR / Small_Value (T));
2937
2938 -- No other types allowed
2939
2940 else
2941 raise Program_Error;
2942 end if;
2943
2944 -- Fall through with Hi and Lo set. Deal with biased case.
2945
2946 if (Biased and then not Is_Fixed_Point_Type (T))
2947 or else Has_Biased_Representation (T)
2948 then
2949 Hi := Hi - Lo;
2950 Lo := Uint_0;
2951 end if;
2952
2953 -- Signed case. Note that we consider types like range 1 .. -1 to be
2954 -- signed for the purpose of computing the size, since the bounds
2955 -- have to be accomodated in the base type.
2956
2957 if Lo < 0 or else Hi < 0 then
2958 S := 1;
2959 B := Uint_1;
2960
2961 -- S = size, B = 2 ** (size - 1) (can accommodate -B .. +(B - 1))
2962 -- Note that we accommodate the case where the bounds cross. This
2963 -- can happen either because of the way the bounds are declared
2964 -- or because of the algorithm in Freeze_Fixed_Point_Type.
2965
2966 while Lo < -B
2967 or else Hi < -B
2968 or else Lo >= B
2969 or else Hi >= B
2970 loop
2971 B := Uint_2 ** S;
2972 S := S + 1;
2973 end loop;
2974
2975 -- Unsigned case
2976
2977 else
2978 -- If both bounds are positive, make sure that both are represen-
2979 -- table in the case where the bounds are crossed. This can happen
2980 -- either because of the way the bounds are declared, or because of
2981 -- the algorithm in Freeze_Fixed_Point_Type.
2982
2983 if Lo > Hi then
2984 Hi := Lo;
2985 end if;
2986
2987 -- S = size, (can accommodate 0 .. (2**size - 1))
2988
2989 S := 0;
2990 while Hi >= Uint_2 ** S loop
2991 S := S + 1;
2992 end loop;
2993 end if;
2994
2995 return S;
2996 end Minimum_Size;
2997
2998 -------------------------
2999 -- New_Stream_Function --
3000 -------------------------
3001
3002 procedure New_Stream_Function
3003 (N : Node_Id;
3004 Ent : Entity_Id;
3005 Subp : Entity_Id;
3006 Nam : Name_Id)
3007 is
3008 Loc : constant Source_Ptr := Sloc (N);
3009 Subp_Id : Entity_Id;
3010 Subp_Decl : Node_Id;
3011 F : Entity_Id;
3012 Etyp : Entity_Id;
3013
3014 function Build_Spec return Node_Id;
3015 -- Used for declaration and renaming declaration, so that this is
3016 -- treated as a renaming_as_body.
3017
3018 ----------------
3019 -- Build_Spec --
3020 ----------------
3021
3022 function Build_Spec return Node_Id is
3023 begin
3024 Subp_Id := Make_Defining_Identifier (Loc, Nam);
3025
3026 return
3027 Make_Function_Specification (Loc,
3028 Defining_Unit_Name => Subp_Id,
3029 Parameter_Specifications =>
3030 New_List (
3031 Make_Parameter_Specification (Loc,
3032 Defining_Identifier =>
3033 Make_Defining_Identifier (Loc, Name_S),
3034 Parameter_Type =>
3035 Make_Access_Definition (Loc,
3036 Subtype_Mark =>
3037 New_Reference_To (
3038 Designated_Type (Etype (F)), Loc)))),
3039
3040 Subtype_Mark =>
3041 New_Reference_To (Etyp, Loc));
3042 end Build_Spec;
3043
3044 -- Start of processing for New_Stream_Function
3045
3046 begin
3047 F := First_Formal (Subp);
3048 Etyp := Etype (Subp);
3049
3050 if not Is_Tagged_Type (Ent) then
3051 Subp_Decl :=
3052 Make_Subprogram_Declaration (Loc,
3053 Specification => Build_Spec);
3054 Insert_Action (N, Subp_Decl);
3055 end if;
3056
3057 Subp_Decl :=
3058 Make_Subprogram_Renaming_Declaration (Loc,
3059 Specification => Build_Spec,
3060 Name => New_Reference_To (Subp, Loc));
3061
3062 if Is_Tagged_Type (Ent) and then not Is_Limited_Type (Ent) then
3063 Set_TSS (Base_Type (Ent), Subp_Id);
3064 else
3065 Insert_Action (N, Subp_Decl);
3066 Copy_TSS (Subp_Id, Base_Type (Ent));
3067 end if;
3068
3069 end New_Stream_Function;
3070
3071 --------------------------
3072 -- New_Stream_Procedure --
3073 --------------------------
3074
3075 procedure New_Stream_Procedure
3076 (N : Node_Id;
3077 Ent : Entity_Id;
3078 Subp : Entity_Id;
3079 Nam : Name_Id;
3080 Out_P : Boolean := False)
3081 is
3082 Loc : constant Source_Ptr := Sloc (N);
3083 Subp_Id : Entity_Id;
3084 Subp_Decl : Node_Id;
3085 F : Entity_Id;
3086 Etyp : Entity_Id;
3087
3088 function Build_Spec return Node_Id;
3089 -- Used for declaration and renaming declaration, so that this is
3090 -- treated as a renaming_as_body.
3091
3092 function Build_Spec return Node_Id is
3093 begin
3094 Subp_Id := Make_Defining_Identifier (Loc, Nam);
3095
3096 return
3097 Make_Procedure_Specification (Loc,
3098 Defining_Unit_Name => Subp_Id,
3099 Parameter_Specifications =>
3100 New_List (
3101 Make_Parameter_Specification (Loc,
3102 Defining_Identifier =>
3103 Make_Defining_Identifier (Loc, Name_S),
3104 Parameter_Type =>
3105 Make_Access_Definition (Loc,
3106 Subtype_Mark =>
3107 New_Reference_To (
3108 Designated_Type (Etype (F)), Loc))),
3109
3110 Make_Parameter_Specification (Loc,
3111 Defining_Identifier =>
3112 Make_Defining_Identifier (Loc, Name_V),
3113 Out_Present => Out_P,
3114 Parameter_Type =>
3115 New_Reference_To (Etyp, Loc))));
3116 end Build_Spec;
3117
3118 -- Start of processing for New_Stream_Function
3119
3120 begin
3121 F := First_Formal (Subp);
3122 Etyp := Etype (Next_Formal (F));
3123
3124 if not Is_Tagged_Type (Ent) then
3125 Subp_Decl :=
3126 Make_Subprogram_Declaration (Loc,
3127 Specification => Build_Spec);
3128 Insert_Action (N, Subp_Decl);
3129 end if;
3130
3131 Subp_Decl :=
3132 Make_Subprogram_Renaming_Declaration (Loc,
3133 Specification => Build_Spec,
3134 Name => New_Reference_To (Subp, Loc));
3135
3136 if Is_Tagged_Type (Ent) and then not Is_Limited_Type (Ent) then
3137 Set_TSS (Base_Type (Ent), Subp_Id);
3138 else
3139 Insert_Action (N, Subp_Decl);
3140 Copy_TSS (Subp_Id, Base_Type (Ent));
3141 end if;
3142
3143 end New_Stream_Procedure;
3144
3145 ---------------------
3146 -- Record_Rep_Item --
3147 ---------------------
3148
3149 procedure Record_Rep_Item (T : Entity_Id; N : Node_Id) is
3150 begin
3151 Set_Next_Rep_Item (N, First_Rep_Item (T));
3152 Set_First_Rep_Item (T, N);
3153 end Record_Rep_Item;
3154
3155 ------------------------
3156 -- Rep_Item_Too_Early --
3157 ------------------------
3158
3159 function Rep_Item_Too_Early
3160 (T : Entity_Id;
3161 N : Node_Id)
3162 return Boolean
3163 is
3164 begin
3165 -- Cannot apply rep items that are not operational items
3166 -- to generic types
3167
3168 if Is_Operational_Item (N) then
3169 return False;
3170
3171 elsif Is_Type (T)
3172 and then Is_Generic_Type (Root_Type (T))
3173 then
3174 Error_Msg_N
3175 ("representation item not allowed for generic type", N);
3176 return True;
3177 end if;
3178
3179 -- Otherwise check for incompleted type
3180
3181 if Is_Incomplete_Or_Private_Type (T)
3182 and then No (Underlying_Type (T))
3183 then
3184 Error_Msg_N
3185 ("representation item must be after full type declaration", N);
3186 return True;
3187
3188 -- If the type has incompleted components, a representation clause is
3189 -- illegal but stream attributes and Convention pragmas are correct.
3190
3191 elsif Has_Private_Component (T) then
3192 if Nkind (N) = N_Pragma then
3193 return False;
3194 else
3195 Error_Msg_N
3196 ("representation item must appear after type is fully defined",
3197 N);
3198 return True;
3199 end if;
3200 else
3201 return False;
3202 end if;
3203 end Rep_Item_Too_Early;
3204
3205 -----------------------
3206 -- Rep_Item_Too_Late --
3207 -----------------------
3208
3209 function Rep_Item_Too_Late
3210 (T : Entity_Id;
3211 N : Node_Id;
3212 FOnly : Boolean := False)
3213 return Boolean
3214 is
3215 S : Entity_Id;
3216 Parent_Type : Entity_Id;
3217
3218 procedure Too_Late;
3219 -- Output the too late message
3220
3221 procedure Too_Late is
3222 begin
3223 Error_Msg_N ("representation item appears too late!", N);
3224 end Too_Late;
3225
3226 -- Start of processing for Rep_Item_Too_Late
3227
3228 begin
3229 -- First make sure entity is not frozen (RM 13.1(9)). Exclude imported
3230 -- types, which may be frozen if they appear in a representation clause
3231 -- for a local type.
3232
3233 if Is_Frozen (T)
3234 and then not From_With_Type (T)
3235 then
3236 Too_Late;
3237 S := First_Subtype (T);
3238
3239 if Present (Freeze_Node (S)) then
3240 Error_Msg_NE
3241 ("?no more representation items for }!", Freeze_Node (S), S);
3242 end if;
3243
3244 return True;
3245
3246 -- Check for case of non-tagged derived type whose parent either has
3247 -- primitive operations, or is a by reference type (RM 13.1(10)).
3248
3249 elsif Is_Type (T)
3250 and then not FOnly
3251 and then Is_Derived_Type (T)
3252 and then not Is_Tagged_Type (T)
3253 then
3254 Parent_Type := Etype (Base_Type (T));
3255
3256 if Has_Primitive_Operations (Parent_Type) then
3257 Too_Late;
3258 Error_Msg_NE
3259 ("primitive operations already defined for&!", N, Parent_Type);
3260 return True;
3261
3262 elsif Is_By_Reference_Type (Parent_Type) then
3263 Too_Late;
3264 Error_Msg_NE
3265 ("parent type & is a by reference type!", N, Parent_Type);
3266 return True;
3267 end if;
3268 end if;
3269
3270 -- No error, link item into head of chain of rep items for the entity
3271
3272 Record_Rep_Item (T, N);
3273 return False;
3274 end Rep_Item_Too_Late;
3275
3276 -------------------------
3277 -- Same_Representation --
3278 -------------------------
3279
3280 function Same_Representation (Typ1, Typ2 : Entity_Id) return Boolean is
3281 T1 : constant Entity_Id := Underlying_Type (Typ1);
3282 T2 : constant Entity_Id := Underlying_Type (Typ2);
3283
3284 begin
3285 -- A quick check, if base types are the same, then we definitely have
3286 -- the same representation, because the subtype specific representation
3287 -- attributes (Size and Alignment) do not affect representation from
3288 -- the point of view of this test.
3289
3290 if Base_Type (T1) = Base_Type (T2) then
3291 return True;
3292
3293 elsif Is_Private_Type (Base_Type (T2))
3294 and then Base_Type (T1) = Full_View (Base_Type (T2))
3295 then
3296 return True;
3297 end if;
3298
3299 -- Tagged types never have differing representations
3300
3301 if Is_Tagged_Type (T1) then
3302 return True;
3303 end if;
3304
3305 -- Representations are definitely different if conventions differ
3306
3307 if Convention (T1) /= Convention (T2) then
3308 return False;
3309 end if;
3310
3311 -- Representations are different if component alignments differ
3312
3313 if (Is_Record_Type (T1) or else Is_Array_Type (T1))
3314 and then
3315 (Is_Record_Type (T2) or else Is_Array_Type (T2))
3316 and then Component_Alignment (T1) /= Component_Alignment (T2)
3317 then
3318 return False;
3319 end if;
3320
3321 -- For arrays, the only real issue is component size. If we know the
3322 -- component size for both arrays, and it is the same, then that's
3323 -- good enough to know we don't have a change of representation.
3324
3325 if Is_Array_Type (T1) then
3326 if Known_Component_Size (T1)
3327 and then Known_Component_Size (T2)
3328 and then Component_Size (T1) = Component_Size (T2)
3329 then
3330 return True;
3331 end if;
3332 end if;
3333
3334 -- Types definitely have same representation if neither has non-standard
3335 -- representation since default representations are always consistent.
3336 -- If only one has non-standard representation, and the other does not,
3337 -- then we consider that they do not have the same representation. They
3338 -- might, but there is no way of telling early enough.
3339
3340 if Has_Non_Standard_Rep (T1) then
3341 if not Has_Non_Standard_Rep (T2) then
3342 return False;
3343 end if;
3344 else
3345 return not Has_Non_Standard_Rep (T2);
3346 end if;
3347
3348 -- Here the two types both have non-standard representation, and we
3349 -- need to determine if they have the same non-standard representation
3350
3351 -- For arrays, we simply need to test if the component sizes are the
3352 -- same. Pragma Pack is reflected in modified component sizes, so this
3353 -- check also deals with pragma Pack.
3354
3355 if Is_Array_Type (T1) then
3356 return Component_Size (T1) = Component_Size (T2);
3357
3358 -- Tagged types always have the same representation, because it is not
3359 -- possible to specify different representations for common fields.
3360
3361 elsif Is_Tagged_Type (T1) then
3362 return True;
3363
3364 -- Case of record types
3365
3366 elsif Is_Record_Type (T1) then
3367
3368 -- Packed status must conform
3369
3370 if Is_Packed (T1) /= Is_Packed (T2) then
3371 return False;
3372
3373 -- Otherwise we must check components. Typ2 maybe a constrained
3374 -- subtype with fewer components, so we compare the components
3375 -- of the base types.
3376
3377 else
3378 Record_Case : declare
3379 CD1, CD2 : Entity_Id;
3380
3381 function Same_Rep return Boolean;
3382 -- CD1 and CD2 are either components or discriminants. This
3383 -- function tests whether the two have the same representation
3384
3385 function Same_Rep return Boolean is
3386 begin
3387 if No (Component_Clause (CD1)) then
3388 return No (Component_Clause (CD2));
3389
3390 else
3391 return
3392 Present (Component_Clause (CD2))
3393 and then
3394 Component_Bit_Offset (CD1) = Component_Bit_Offset (CD2)
3395 and then
3396 Esize (CD1) = Esize (CD2);
3397 end if;
3398 end Same_Rep;
3399
3400 -- Start processing for Record_Case
3401
3402 begin
3403 if Has_Discriminants (T1) then
3404 CD1 := First_Discriminant (T1);
3405 CD2 := First_Discriminant (T2);
3406
3407 while Present (CD1) loop
3408 if not Same_Rep then
3409 return False;
3410 else
3411 Next_Discriminant (CD1);
3412 Next_Discriminant (CD2);
3413 end if;
3414 end loop;
3415 end if;
3416
3417 CD1 := First_Component (Underlying_Type (Base_Type (T1)));
3418 CD2 := First_Component (Underlying_Type (Base_Type (T2)));
3419
3420 while Present (CD1) loop
3421 if not Same_Rep then
3422 return False;
3423 else
3424 Next_Component (CD1);
3425 Next_Component (CD2);
3426 end if;
3427 end loop;
3428
3429 return True;
3430 end Record_Case;
3431 end if;
3432
3433 -- For enumeration types, we must check each literal to see if the
3434 -- representation is the same. Note that we do not permit enumeration
3435 -- representation clauses for Character and Wide_Character, so these
3436 -- cases were already dealt with.
3437
3438 elsif Is_Enumeration_Type (T1) then
3439
3440 Enumeration_Case : declare
3441 L1, L2 : Entity_Id;
3442
3443 begin
3444 L1 := First_Literal (T1);
3445 L2 := First_Literal (T2);
3446
3447 while Present (L1) loop
3448 if Enumeration_Rep (L1) /= Enumeration_Rep (L2) then
3449 return False;
3450 else
3451 Next_Literal (L1);
3452 Next_Literal (L2);
3453 end if;
3454 end loop;
3455
3456 return True;
3457
3458 end Enumeration_Case;
3459
3460 -- Any other types have the same representation for these purposes
3461
3462 else
3463 return True;
3464 end if;
3465
3466 end Same_Representation;
3467
3468 --------------------
3469 -- Set_Enum_Esize --
3470 --------------------
3471
3472 procedure Set_Enum_Esize (T : Entity_Id) is
3473 Lo : Uint;
3474 Hi : Uint;
3475 Sz : Nat;
3476
3477 begin
3478 Init_Alignment (T);
3479
3480 -- Find the minimum standard size (8,16,32,64) that fits
3481
3482 Lo := Enumeration_Rep (Entity (Type_Low_Bound (T)));
3483 Hi := Enumeration_Rep (Entity (Type_High_Bound (T)));
3484
3485 if Lo < 0 then
3486 if Lo >= -Uint_2**07 and then Hi < Uint_2**07 then
3487 Sz := Standard_Character_Size; -- May be > 8 on some targets
3488
3489 elsif Lo >= -Uint_2**15 and then Hi < Uint_2**15 then
3490 Sz := 16;
3491
3492 elsif Lo >= -Uint_2**31 and then Hi < Uint_2**31 then
3493 Sz := 32;
3494
3495 else pragma Assert (Lo >= -Uint_2**63 and then Hi < Uint_2**63);
3496 Sz := 64;
3497 end if;
3498
3499 else
3500 if Hi < Uint_2**08 then
3501 Sz := Standard_Character_Size; -- May be > 8 on some targets
3502
3503 elsif Hi < Uint_2**16 then
3504 Sz := 16;
3505
3506 elsif Hi < Uint_2**32 then
3507 Sz := 32;
3508
3509 else pragma Assert (Hi < Uint_2**63);
3510 Sz := 64;
3511 end if;
3512 end if;
3513
3514 -- That minimum is the proper size unless we have a foreign convention
3515 -- and the size required is 32 or less, in which case we bump the size
3516 -- up to 32. This is required for C and C++ and seems reasonable for
3517 -- all other foreign conventions.
3518
3519 if Has_Foreign_Convention (T)
3520 and then Esize (T) < Standard_Integer_Size
3521 then
3522 Init_Esize (T, Standard_Integer_Size);
3523
3524 else
3525 Init_Esize (T, Sz);
3526 end if;
3527
3528 end Set_Enum_Esize;
3529
3530 -----------------------------------
3531 -- Validate_Unchecked_Conversion --
3532 -----------------------------------
3533
3534 procedure Validate_Unchecked_Conversion
3535 (N : Node_Id;
3536 Act_Unit : Entity_Id)
3537 is
3538 Source : Entity_Id;
3539 Target : Entity_Id;
3540 Vnode : Node_Id;
3541
3542 begin
3543 -- Obtain source and target types. Note that we call Ancestor_Subtype
3544 -- here because the processing for generic instantiation always makes
3545 -- subtypes, and we want the original frozen actual types.
3546
3547 -- If we are dealing with private types, then do the check on their
3548 -- fully declared counterparts if the full declarations have been
3549 -- encountered (they don't have to be visible, but they must exist!)
3550
3551 Source := Ancestor_Subtype (Etype (First_Formal (Act_Unit)));
3552
3553 if Is_Private_Type (Source)
3554 and then Present (Underlying_Type (Source))
3555 then
3556 Source := Underlying_Type (Source);
3557 end if;
3558
3559 Target := Ancestor_Subtype (Etype (Act_Unit));
3560
3561 -- If either type is generic, the instantiation happens within a
3562 -- generic unit, and there is nothing to check. The proper check
3563 -- will happen when the enclosing generic is instantiated.
3564
3565 if Is_Generic_Type (Source) or else Is_Generic_Type (Target) then
3566 return;
3567 end if;
3568
3569 if Is_Private_Type (Target)
3570 and then Present (Underlying_Type (Target))
3571 then
3572 Target := Underlying_Type (Target);
3573 end if;
3574
3575 -- Source may be unconstrained array, but not target
3576
3577 if Is_Array_Type (Target)
3578 and then not Is_Constrained (Target)
3579 then
3580 Error_Msg_N
3581 ("unchecked conversion to unconstrained array not allowed", N);
3582 return;
3583 end if;
3584
3585 -- Make entry in unchecked conversion table for later processing
3586 -- by Validate_Unchecked_Conversions, which will check sizes and
3587 -- alignments (using values set by the back-end where possible).
3588
3589 Unchecked_Conversions.Append
3590 (New_Val => UC_Entry'
3591 (Enode => N,
3592 Source => Source,
3593 Target => Target));
3594
3595 -- Generate N_Validate_Unchecked_Conversion node for back end if
3596 -- the back end needs to perform special validation checks. At the
3597 -- current time, only the JVM version requires such checks.
3598
3599 if Java_VM then
3600 Vnode :=
3601 Make_Validate_Unchecked_Conversion (Sloc (N));
3602 Set_Source_Type (Vnode, Source);
3603 Set_Target_Type (Vnode, Target);
3604 Insert_After (N, Vnode);
3605 end if;
3606 end Validate_Unchecked_Conversion;
3607
3608 ------------------------------------
3609 -- Validate_Unchecked_Conversions --
3610 ------------------------------------
3611
3612 procedure Validate_Unchecked_Conversions is
3613 begin
3614 for N in Unchecked_Conversions.First .. Unchecked_Conversions.Last loop
3615 declare
3616 T : UC_Entry renames Unchecked_Conversions.Table (N);
3617
3618 Enode : constant Node_Id := T.Enode;
3619 Source : constant Entity_Id := T.Source;
3620 Target : constant Entity_Id := T.Target;
3621
3622 Source_Siz : Uint;
3623 Target_Siz : Uint;
3624
3625 begin
3626 -- This validation check, which warns if we have unequal sizes
3627 -- for unchecked conversion, and thus potentially implementation
3628 -- dependent semantics, is one of the few occasions on which we
3629 -- use the official RM size instead of Esize. See description
3630 -- in Einfo "Handling of Type'Size Values" for details.
3631
3632 if Serious_Errors_Detected = 0
3633 and then Known_Static_RM_Size (Source)
3634 and then Known_Static_RM_Size (Target)
3635 then
3636 Source_Siz := RM_Size (Source);
3637 Target_Siz := RM_Size (Target);
3638
3639 if Source_Siz /= Target_Siz then
3640 Warn_On_Instance := True;
3641 Error_Msg_N
3642 ("types for unchecked conversion have different sizes?",
3643 Enode);
3644
3645 if All_Errors_Mode then
3646 Error_Msg_Name_1 := Chars (Source);
3647 Error_Msg_Uint_1 := Source_Siz;
3648 Error_Msg_Name_2 := Chars (Target);
3649 Error_Msg_Uint_2 := Target_Siz;
3650 Error_Msg_N
3651 ("\size of % is ^, size of % is ^?", Enode);
3652
3653 Error_Msg_Uint_1 := UI_Abs (Source_Siz - Target_Siz);
3654
3655 if Is_Discrete_Type (Source)
3656 and then Is_Discrete_Type (Target)
3657 then
3658 if Source_Siz > Target_Siz then
3659 Error_Msg_N
3660 ("\^ high order bits of source will be ignored?",
3661 Enode);
3662
3663 elsif Is_Modular_Integer_Type (Source) then
3664 Error_Msg_N
3665 ("\source will be extended with ^ high order " &
3666 "zero bits?", Enode);
3667
3668 else
3669 Error_Msg_N
3670 ("\source will be extended with ^ high order " &
3671 "sign bits?",
3672 Enode);
3673 end if;
3674
3675 elsif Source_Siz < Target_Siz then
3676 if Is_Discrete_Type (Target) then
3677 if Bytes_Big_Endian then
3678 Error_Msg_N
3679 ("\target value will include ^ undefined " &
3680 "low order bits?",
3681 Enode);
3682 else
3683 Error_Msg_N
3684 ("\target value will include ^ undefined " &
3685 "high order bits?",
3686 Enode);
3687 end if;
3688
3689 else
3690 Error_Msg_N
3691 ("\^ trailing bits of target value will be " &
3692 "undefined?", Enode);
3693 end if;
3694
3695 else pragma Assert (Source_Siz > Target_Siz);
3696 Error_Msg_N
3697 ("\^ trailing bits of source will be ignored?",
3698 Enode);
3699 end if;
3700 end if;
3701
3702 Warn_On_Instance := False;
3703 end if;
3704 end if;
3705
3706 -- If both types are access types, we need to check the alignment.
3707 -- If the alignment of both is specified, we can do it here.
3708
3709 if Serious_Errors_Detected = 0
3710 and then Ekind (Source) in Access_Kind
3711 and then Ekind (Target) in Access_Kind
3712 and then Target_Strict_Alignment
3713 and then Present (Designated_Type (Source))
3714 and then Present (Designated_Type (Target))
3715 then
3716 declare
3717 D_Source : constant Entity_Id := Designated_Type (Source);
3718 D_Target : constant Entity_Id := Designated_Type (Target);
3719
3720 begin
3721 if Known_Alignment (D_Source)
3722 and then Known_Alignment (D_Target)
3723 then
3724 declare
3725 Source_Align : constant Uint := Alignment (D_Source);
3726 Target_Align : constant Uint := Alignment (D_Target);
3727
3728 begin
3729 if Source_Align < Target_Align
3730 and then not Is_Tagged_Type (D_Source)
3731 then
3732 Warn_On_Instance := True;
3733 Error_Msg_Uint_1 := Target_Align;
3734 Error_Msg_Uint_2 := Source_Align;
3735 Error_Msg_Node_2 := D_Source;
3736 Error_Msg_NE
3737 ("alignment of & (^) is stricter than " &
3738 "alignment of & (^)?", Enode, D_Target);
3739
3740 if All_Errors_Mode then
3741 Error_Msg_N
3742 ("\resulting access value may have invalid " &
3743 "alignment?", Enode);
3744 end if;
3745
3746 Warn_On_Instance := False;
3747 end if;
3748 end;
3749 end if;
3750 end;
3751 end if;
3752 end;
3753 end loop;
3754 end Validate_Unchecked_Conversions;
3755
3756 ------------------
3757 -- Warn_Overlay --
3758 ------------------
3759
3760 procedure Warn_Overlay
3761 (Expr : Node_Id;
3762 Typ : Entity_Id;
3763 Nam : Node_Id)
3764 is
3765 Old : Entity_Id := Empty;
3766 Decl : Node_Id;
3767
3768 begin
3769 if not Address_Clause_Overlay_Warnings then
3770 return;
3771 end if;
3772
3773 if Present (Expr)
3774 and then (Has_Non_Null_Base_Init_Proc (Typ)
3775 or else Is_Access_Type (Typ))
3776 and then not Is_Imported (Entity (Nam))
3777 then
3778 if Nkind (Expr) = N_Attribute_Reference
3779 and then Is_Entity_Name (Prefix (Expr))
3780 then
3781 Old := Entity (Prefix (Expr));
3782
3783 elsif Is_Entity_Name (Expr)
3784 and then Ekind (Entity (Expr)) = E_Constant
3785 then
3786 Decl := Declaration_Node (Entity (Expr));
3787
3788 if Nkind (Decl) = N_Object_Declaration
3789 and then Present (Expression (Decl))
3790 and then Nkind (Expression (Decl)) = N_Attribute_Reference
3791 and then Is_Entity_Name (Prefix (Expression (Decl)))
3792 then
3793 Old := Entity (Prefix (Expression (Decl)));
3794
3795 elsif Nkind (Expr) = N_Function_Call then
3796 return;
3797 end if;
3798
3799 -- A function call (most likely to To_Address) is probably not
3800 -- an overlay, so skip warning. Ditto if the function call was
3801 -- inlined and transformed into an entity.
3802
3803 elsif Nkind (Original_Node (Expr)) = N_Function_Call then
3804 return;
3805 end if;
3806
3807 Decl := Next (Parent (Expr));
3808
3809 -- If a pragma Import follows, we assume that it is for the current
3810 -- target of the address clause, and skip the warning.
3811
3812 if Present (Decl)
3813 and then Nkind (Decl) = N_Pragma
3814 and then Chars (Decl) = Name_Import
3815 then
3816 return;
3817 end if;
3818
3819 if Present (Old) then
3820 Error_Msg_Node_2 := Old;
3821 Error_Msg_N
3822 ("default initialization of & may modify &?",
3823 Nam);
3824 else
3825 Error_Msg_N
3826 ("default initialization of & may modify overlaid storage?",
3827 Nam);
3828 end if;
3829
3830 -- Add friendly warning if initialization comes from a packed array
3831 -- component.
3832
3833 if Is_Record_Type (Typ) then
3834 declare
3835 Comp : Entity_Id;
3836
3837 begin
3838 Comp := First_Component (Typ);
3839
3840 while Present (Comp) loop
3841 if Nkind (Parent (Comp)) = N_Component_Declaration
3842 and then Present (Expression (Parent (Comp)))
3843 then
3844 exit;
3845 elsif Is_Array_Type (Etype (Comp))
3846 and then Present (Packed_Array_Type (Etype (Comp)))
3847 then
3848 Error_Msg_NE
3849 ("packed array component& will be initialized to zero?",
3850 Nam, Comp);
3851 exit;
3852 else
3853 Next_Component (Comp);
3854 end if;
3855 end loop;
3856 end;
3857 end if;
3858
3859 Error_Msg_N
3860 ("use pragma Import for & to " &
3861 "suppress initialization ('R'M B.1(24))?",
3862 Nam);
3863 end if;
3864 end Warn_Overlay;
3865
3866 end Sem_Ch13;
Mirror of the offical gcc git repository hosted at gcc.gnu.org