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2010-06-17 Thomas Quinot <quinot@adacore.com>
[thirdparty/gcc.git] / gcc / ada / sem_ch13.adb
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d6f39728 1------------------------------------------------------------------------------
7189d17f 2-- --
d6f39728 3-- GNAT COMPILER COMPONENTS --
4-- --
5-- S E M _ C H 1 3 --
6-- --
7-- B o d y --
8-- --
eef1ca1e 9-- Copyright (C) 1992-2009, Free Software Foundation, Inc. --
d6f39728 10-- --
11-- GNAT is free software; you can redistribute it and/or modify it under --
12-- terms of the GNU General Public License as published by the Free Soft- --
80df182a 13-- ware Foundation; either version 3, or (at your option) any later ver- --
d6f39728 14-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17-- for more details. You should have received a copy of the GNU General --
80df182a 18-- Public License distributed with GNAT; see file COPYING3. If not, go to --
19-- http://www.gnu.org/licenses for a complete copy of the license. --
d6f39728 20-- --
21-- GNAT was originally developed by the GNAT team at New York University. --
e78e8c8e 22-- Extensive contributions were provided by Ada Core Technologies Inc. --
d6f39728 23-- --
24------------------------------------------------------------------------------
25
26with Atree; use Atree;
713c00d6 27with Checks; use Checks;
d6f39728 28with Einfo; use Einfo;
29with Errout; use Errout;
30with Exp_Tss; use Exp_Tss;
31with Exp_Util; use Exp_Util;
d6f39728 32with Lib; use Lib;
83f8f0a6 33with Lib.Xref; use Lib.Xref;
15ebb600 34with Namet; use Namet;
d6f39728 35with Nlists; use Nlists;
36with Nmake; use Nmake;
37with Opt; use Opt;
e0521a36 38with Restrict; use Restrict;
39with Rident; use Rident;
d6f39728 40with Rtsfind; use Rtsfind;
41with Sem; use Sem;
d60c9ff7 42with Sem_Aux; use Sem_Aux;
40ca69b9 43with Sem_Ch3; use Sem_Ch3;
d6f39728 44with Sem_Ch8; use Sem_Ch8;
45with Sem_Eval; use Sem_Eval;
46with Sem_Res; use Sem_Res;
47with Sem_Type; use Sem_Type;
48with Sem_Util; use Sem_Util;
44e4341e 49with Sem_Warn; use Sem_Warn;
9dfe12ae 50with Snames; use Snames;
d6f39728 51with Stand; use Stand;
52with Sinfo; use Sinfo;
d6f39728 53with Table;
93735cb8 54with Targparm; use Targparm;
d6f39728 55with Ttypes; use Ttypes;
56with Tbuild; use Tbuild;
57with Urealp; use Urealp;
58
bfa5a9d9 59with GNAT.Heap_Sort_G;
d6f39728 60
61package body Sem_Ch13 is
62
63 SSU : constant Pos := System_Storage_Unit;
64 -- Convenient short hand for commonly used constant
65
66 -----------------------
67 -- Local Subprograms --
68 -----------------------
69
70 procedure Alignment_Check_For_Esize_Change (Typ : Entity_Id);
71 -- This routine is called after setting the Esize of type entity Typ.
1a34e48c 72 -- The purpose is to deal with the situation where an alignment has been
d6f39728 73 -- inherited from a derived type that is no longer appropriate for the
74 -- new Esize value. In this case, we reset the Alignment to unknown.
75
d6f39728 76 function Get_Alignment_Value (Expr : Node_Id) return Uint;
77 -- Given the expression for an alignment value, returns the corresponding
78 -- Uint value. If the value is inappropriate, then error messages are
79 -- posted as required, and a value of No_Uint is returned.
80
81 function Is_Operational_Item (N : Node_Id) return Boolean;
82 -- A specification for a stream attribute is allowed before the full
83 -- type is declared, as explained in AI-00137 and the corrigendum.
84 -- Attributes that do not specify a representation characteristic are
85 -- operational attributes.
86
44e4341e 87 procedure New_Stream_Subprogram
d6f39728 88 (N : Node_Id;
89 Ent : Entity_Id;
90 Subp : Entity_Id;
9dfe12ae 91 Nam : TSS_Name_Type);
44e4341e 92 -- Create a subprogram renaming of a given stream attribute to the
93 -- designated subprogram and then in the tagged case, provide this as a
94 -- primitive operation, or in the non-tagged case make an appropriate TSS
95 -- entry. This is more properly an expansion activity than just semantics,
96 -- but the presence of user-defined stream functions for limited types is a
97 -- legality check, which is why this takes place here rather than in
98 -- exp_ch13, where it was previously. Nam indicates the name of the TSS
99 -- function to be generated.
9dfe12ae 100 --
f15731c4 101 -- To avoid elaboration anomalies with freeze nodes, for untagged types
102 -- we generate both a subprogram declaration and a subprogram renaming
103 -- declaration, so that the attribute specification is handled as a
104 -- renaming_as_body. For tagged types, the specification is one of the
105 -- primitive specs.
106
d6f39728 107 ----------------------------------------------
108 -- Table for Validate_Unchecked_Conversions --
109 ----------------------------------------------
110
111 -- The following table collects unchecked conversions for validation.
112 -- Entries are made by Validate_Unchecked_Conversion and then the
113 -- call to Validate_Unchecked_Conversions does the actual error
114 -- checking and posting of warnings. The reason for this delayed
115 -- processing is to take advantage of back-annotations of size and
1a34e48c 116 -- alignment values performed by the back end.
d6f39728 117
299480f9 118 -- Note: the reason we store a Source_Ptr value instead of a Node_Id
119 -- is that by the time Validate_Unchecked_Conversions is called, Sprint
120 -- will already have modified all Sloc values if the -gnatD option is set.
121
d6f39728 122 type UC_Entry is record
299480f9 123 Eloc : Source_Ptr; -- node used for posting warnings
124 Source : Entity_Id; -- source type for unchecked conversion
125 Target : Entity_Id; -- target type for unchecked conversion
d6f39728 126 end record;
127
128 package Unchecked_Conversions is new Table.Table (
129 Table_Component_Type => UC_Entry,
130 Table_Index_Type => Int,
131 Table_Low_Bound => 1,
132 Table_Initial => 50,
133 Table_Increment => 200,
134 Table_Name => "Unchecked_Conversions");
135
83f8f0a6 136 ----------------------------------------
137 -- Table for Validate_Address_Clauses --
138 ----------------------------------------
139
140 -- If an address clause has the form
141
142 -- for X'Address use Expr
143
144 -- where Expr is of the form Y'Address or recursively is a reference
145 -- to a constant of either of these forms, and X and Y are entities of
146 -- objects, then if Y has a smaller alignment than X, that merits a
147 -- warning about possible bad alignment. The following table collects
148 -- address clauses of this kind. We put these in a table so that they
149 -- can be checked after the back end has completed annotation of the
150 -- alignments of objects, since we can catch more cases that way.
151
152 type Address_Clause_Check_Record is record
153 N : Node_Id;
154 -- The address clause
155
156 X : Entity_Id;
157 -- The entity of the object overlaying Y
158
159 Y : Entity_Id;
160 -- The entity of the object being overlaid
d6da7448 161
162 Off : Boolean;
163 -- Whether the address is offseted within Y
83f8f0a6 164 end record;
165
166 package Address_Clause_Checks is new Table.Table (
167 Table_Component_Type => Address_Clause_Check_Record,
168 Table_Index_Type => Int,
169 Table_Low_Bound => 1,
170 Table_Initial => 20,
171 Table_Increment => 200,
172 Table_Name => "Address_Clause_Checks");
173
59ac57b5 174 -----------------------------------------
175 -- Adjust_Record_For_Reverse_Bit_Order --
176 -----------------------------------------
177
178 procedure Adjust_Record_For_Reverse_Bit_Order (R : Entity_Id) is
67278d60 179 Comp : Node_Id;
180 CC : Node_Id;
59ac57b5 181
182 begin
67278d60 183 -- Processing depends on version of Ada
59ac57b5 184
67278d60 185 case Ada_Version is
59ac57b5 186
67278d60 187 -- For Ada 95, we just renumber bits within a storage unit. We do
188 -- the same for Ada 83 mode, since we recognize pragma Bit_Order
189 -- in Ada 83, and are free to add this extension.
59ac57b5 190
67278d60 191 when Ada_83 | Ada_95 =>
192 Comp := First_Component_Or_Discriminant (R);
193 while Present (Comp) loop
194 CC := Component_Clause (Comp);
59ac57b5 195
67278d60 196 -- If component clause is present, then deal with the non-
197 -- default bit order case for Ada 95 mode.
59ac57b5 198
67278d60 199 -- We only do this processing for the base type, and in
200 -- fact that's important, since otherwise if there are
201 -- record subtypes, we could reverse the bits once for
202 -- each subtype, which would be incorrect.
59ac57b5 203
67278d60 204 if Present (CC)
205 and then Ekind (R) = E_Record_Type
206 then
207 declare
208 CFB : constant Uint := Component_Bit_Offset (Comp);
209 CSZ : constant Uint := Esize (Comp);
210 CLC : constant Node_Id := Component_Clause (Comp);
211 Pos : constant Node_Id := Position (CLC);
212 FB : constant Node_Id := First_Bit (CLC);
59ac57b5 213
67278d60 214 Storage_Unit_Offset : constant Uint :=
215 CFB / System_Storage_Unit;
59ac57b5 216
67278d60 217 Start_Bit : constant Uint :=
218 CFB mod System_Storage_Unit;
59ac57b5 219
67278d60 220 begin
221 -- Cases where field goes over storage unit boundary
59ac57b5 222
67278d60 223 if Start_Bit + CSZ > System_Storage_Unit then
59ac57b5 224
67278d60 225 -- Allow multi-byte field but generate warning
31486bc0 226
67278d60 227 if Start_Bit mod System_Storage_Unit = 0
228 and then CSZ mod System_Storage_Unit = 0
229 then
31486bc0 230 Error_Msg_N
67278d60 231 ("multi-byte field specified with non-standard"
232 & " Bit_Order?", CLC);
233
234 if Bytes_Big_Endian then
235 Error_Msg_N
236 ("bytes are not reversed "
237 & "(component is big-endian)?", CLC);
238 else
239 Error_Msg_N
240 ("bytes are not reversed "
241 & "(component is little-endian)?", CLC);
242 end if;
243
244 -- Do not allow non-contiguous field
245
31486bc0 246 else
247 Error_Msg_N
67278d60 248 ("attempt to specify non-contiguous field "
249 & "not permitted", CLC);
250 Error_Msg_N
251 ("\caused by non-standard Bit_Order "
252 & "specified", CLC);
253 Error_Msg_N
254 ("\consider possibility of using "
255 & "Ada 2005 mode here", CLC);
31486bc0 256 end if;
59ac57b5 257
67278d60 258 -- Case where field fits in one storage unit
59ac57b5 259
67278d60 260 else
261 -- Give warning if suspicious component clause
59ac57b5 262
67278d60 263 if Intval (FB) >= System_Storage_Unit
264 and then Warn_On_Reverse_Bit_Order
265 then
266 Error_Msg_N
267 ("?Bit_Order clause does not affect " &
268 "byte ordering", Pos);
269 Error_Msg_Uint_1 :=
270 Intval (Pos) + Intval (FB) /
271 System_Storage_Unit;
272 Error_Msg_N
273 ("?position normalized to ^ before bit " &
274 "order interpreted", Pos);
275 end if;
59ac57b5 276
67278d60 277 -- Here is where we fix up the Component_Bit_Offset
278 -- value to account for the reverse bit order.
279 -- Some examples of what needs to be done are:
59ac57b5 280
67278d60 281 -- First_Bit .. Last_Bit Component_Bit_Offset
282 -- old new old new
59ac57b5 283
67278d60 284 -- 0 .. 0 7 .. 7 0 7
285 -- 0 .. 1 6 .. 7 0 6
286 -- 0 .. 2 5 .. 7 0 5
287 -- 0 .. 7 0 .. 7 0 4
59ac57b5 288
67278d60 289 -- 1 .. 1 6 .. 6 1 6
290 -- 1 .. 4 3 .. 6 1 3
291 -- 4 .. 7 0 .. 3 4 0
bfa5a9d9 292
67278d60 293 -- The general rule is that the first bit is
294 -- is obtained by subtracting the old ending bit
295 -- from storage_unit - 1.
59ac57b5 296
67278d60 297 Set_Component_Bit_Offset
298 (Comp,
299 (Storage_Unit_Offset * System_Storage_Unit) +
300 (System_Storage_Unit - 1) -
301 (Start_Bit + CSZ - 1));
59ac57b5 302
67278d60 303 Set_Normalized_First_Bit
304 (Comp,
305 Component_Bit_Offset (Comp) mod
306 System_Storage_Unit);
307 end if;
308 end;
309 end if;
59ac57b5 310
67278d60 311 Next_Component_Or_Discriminant (Comp);
312 end loop;
59ac57b5 313
67278d60 314 -- For Ada 2005, we do machine scalar processing, as fully described
315 -- In AI-133. This involves gathering all components which start at
316 -- the same byte offset and processing them together
59ac57b5 317
67278d60 318 when Ada_05 =>
319 declare
320 Max_Machine_Scalar_Size : constant Uint :=
321 UI_From_Int
322 (Standard_Long_Long_Integer_Size);
323 -- We use this as the maximum machine scalar size
59ac57b5 324
67278d60 325 Num_CC : Natural;
326 SSU : constant Uint := UI_From_Int (System_Storage_Unit);
59ac57b5 327
67278d60 328 begin
329 -- This first loop through components does two things. First it
330 -- deals with the case of components with component clauses
331 -- whose length is greater than the maximum machine scalar size
332 -- (either accepting them or rejecting as needed). Second, it
333 -- counts the number of components with component clauses whose
334 -- length does not exceed this maximum for later processing.
335
336 Num_CC := 0;
337 Comp := First_Component_Or_Discriminant (R);
338 while Present (Comp) loop
339 CC := Component_Clause (Comp);
340
341 if Present (CC) then
342 declare
343 Fbit : constant Uint :=
344 Static_Integer (First_Bit (CC));
345
346 begin
347 -- Case of component with size > max machine scalar
348
349 if Esize (Comp) > Max_Machine_Scalar_Size then
350
351 -- Must begin on byte boundary
352
353 if Fbit mod SSU /= 0 then
354 Error_Msg_N
355 ("illegal first bit value for "
356 & "reverse bit order",
357 First_Bit (CC));
358 Error_Msg_Uint_1 := SSU;
359 Error_Msg_Uint_2 := Max_Machine_Scalar_Size;
360
361 Error_Msg_N
362 ("\must be a multiple of ^ "
363 & "if size greater than ^",
364 First_Bit (CC));
365
366 -- Must end on byte boundary
367
368 elsif Esize (Comp) mod SSU /= 0 then
369 Error_Msg_N
370 ("illegal last bit value for "
371 & "reverse bit order",
372 Last_Bit (CC));
373 Error_Msg_Uint_1 := SSU;
374 Error_Msg_Uint_2 := Max_Machine_Scalar_Size;
375
376 Error_Msg_N
377 ("\must be a multiple of ^ if size "
378 & "greater than ^",
379 Last_Bit (CC));
380
381 -- OK, give warning if enabled
382
383 elsif Warn_On_Reverse_Bit_Order then
384 Error_Msg_N
385 ("multi-byte field specified with "
386 & " non-standard Bit_Order?", CC);
387
388 if Bytes_Big_Endian then
389 Error_Msg_N
390 ("\bytes are not reversed "
391 & "(component is big-endian)?", CC);
392 else
393 Error_Msg_N
394 ("\bytes are not reversed "
395 & "(component is little-endian)?", CC);
396 end if;
397 end if;
59ac57b5 398
67278d60 399 -- Case where size is not greater than max machine
400 -- scalar. For now, we just count these.
59ac57b5 401
67278d60 402 else
403 Num_CC := Num_CC + 1;
404 end if;
405 end;
406 end if;
59ac57b5 407
67278d60 408 Next_Component_Or_Discriminant (Comp);
409 end loop;
59ac57b5 410
67278d60 411 -- We need to sort the component clauses on the basis of the
412 -- Position values in the clause, so we can group clauses with
413 -- the same Position. together to determine the relevant
414 -- machine scalar size.
59ac57b5 415
67278d60 416 Sort_CC : declare
417 Comps : array (0 .. Num_CC) of Entity_Id;
418 -- Array to collect component and discriminant entities. The
419 -- data starts at index 1, the 0'th entry is for the sort
420 -- routine.
59ac57b5 421
67278d60 422 function CP_Lt (Op1, Op2 : Natural) return Boolean;
423 -- Compare routine for Sort
59ac57b5 424
67278d60 425 procedure CP_Move (From : Natural; To : Natural);
426 -- Move routine for Sort
59ac57b5 427
67278d60 428 package Sorting is new GNAT.Heap_Sort_G (CP_Move, CP_Lt);
59ac57b5 429
67278d60 430 Start : Natural;
431 Stop : Natural;
432 -- Start and stop positions in component list of set of
433 -- components with the same starting position (that
434 -- constitute components in a single machine scalar).
59ac57b5 435
67278d60 436 MaxL : Uint;
437 -- Maximum last bit value of any component in this set
59ac57b5 438
67278d60 439 MSS : Uint;
440 -- Corresponding machine scalar size
441
442 -----------
443 -- CP_Lt --
444 -----------
445
446 function CP_Lt (Op1, Op2 : Natural) return Boolean is
447 begin
448 return Position (Component_Clause (Comps (Op1))) <
449 Position (Component_Clause (Comps (Op2)));
450 end CP_Lt;
451
452 -------------
453 -- CP_Move --
454 -------------
455
456 procedure CP_Move (From : Natural; To : Natural) is
457 begin
458 Comps (To) := Comps (From);
459 end CP_Move;
460
461 -- Start of processing for Sort_CC
59ac57b5 462
463 begin
67278d60 464 -- Collect the component clauses
59ac57b5 465
67278d60 466 Num_CC := 0;
467 Comp := First_Component_Or_Discriminant (R);
468 while Present (Comp) loop
469 if Present (Component_Clause (Comp))
470 and then Esize (Comp) <= Max_Machine_Scalar_Size
471 then
472 Num_CC := Num_CC + 1;
473 Comps (Num_CC) := Comp;
59ac57b5 474 end if;
59ac57b5 475
67278d60 476 Next_Component_Or_Discriminant (Comp);
477 end loop;
478
479 -- Sort by ascending position number
480
481 Sorting.Sort (Num_CC);
482
483 -- We now have all the components whose size does not exceed
484 -- the max machine scalar value, sorted by starting
485 -- position. In this loop we gather groups of clauses
486 -- starting at the same position, to process them in
487 -- accordance with Ada 2005 AI-133.
488
489 Stop := 0;
490 while Stop < Num_CC loop
491 Start := Stop + 1;
492 Stop := Start;
493 MaxL :=
494 Static_Integer
495 (Last_Bit (Component_Clause (Comps (Start))));
496 while Stop < Num_CC loop
497 if Static_Integer
498 (Position (Component_Clause (Comps (Stop + 1)))) =
499 Static_Integer
500 (Position (Component_Clause (Comps (Stop))))
501 then
502 Stop := Stop + 1;
503 MaxL :=
504 UI_Max
505 (MaxL,
506 Static_Integer
507 (Last_Bit
508 (Component_Clause (Comps (Stop)))));
509 else
510 exit;
511 end if;
512 end loop;
513
514 -- Now we have a group of component clauses from Start to
515 -- Stop whose positions are identical, and MaxL is the
516 -- maximum last bit value of any of these components.
517
518 -- We need to determine the corresponding machine scalar
519 -- size. This loop assumes that machine scalar sizes are
520 -- even, and that each possible machine scalar has twice
521 -- as many bits as the next smaller one.
522
523 MSS := Max_Machine_Scalar_Size;
524 while MSS mod 2 = 0
525 and then (MSS / 2) >= SSU
526 and then (MSS / 2) > MaxL
527 loop
528 MSS := MSS / 2;
529 end loop;
530
531 -- Here is where we fix up the Component_Bit_Offset value
532 -- to account for the reverse bit order. Some examples of
533 -- what needs to be done for the case of a machine scalar
534 -- size of 8 are:
535
536 -- First_Bit .. Last_Bit Component_Bit_Offset
537 -- old new old new
538
539 -- 0 .. 0 7 .. 7 0 7
540 -- 0 .. 1 6 .. 7 0 6
541 -- 0 .. 2 5 .. 7 0 5
542 -- 0 .. 7 0 .. 7 0 4
543
544 -- 1 .. 1 6 .. 6 1 6
545 -- 1 .. 4 3 .. 6 1 3
546 -- 4 .. 7 0 .. 3 4 0
547
548 -- The general rule is that the first bit is obtained by
549 -- subtracting the old ending bit from machine scalar
550 -- size - 1.
551
552 for C in Start .. Stop loop
553 declare
554 Comp : constant Entity_Id := Comps (C);
555 CC : constant Node_Id :=
556 Component_Clause (Comp);
557 LB : constant Uint :=
558 Static_Integer (Last_Bit (CC));
559 NFB : constant Uint := MSS - Uint_1 - LB;
560 NLB : constant Uint := NFB + Esize (Comp) - 1;
561 Pos : constant Uint :=
562 Static_Integer (Position (CC));
563
564 begin
565 if Warn_On_Reverse_Bit_Order then
566 Error_Msg_Uint_1 := MSS;
567 Error_Msg_N
568 ("info: reverse bit order in machine " &
569 "scalar of length^?", First_Bit (CC));
570 Error_Msg_Uint_1 := NFB;
571 Error_Msg_Uint_2 := NLB;
572
573 if Bytes_Big_Endian then
574 Error_Msg_NE
575 ("?\info: big-endian range for "
576 & "component & is ^ .. ^",
577 First_Bit (CC), Comp);
578 else
579 Error_Msg_NE
580 ("?\info: little-endian range "
581 & "for component & is ^ .. ^",
582 First_Bit (CC), Comp);
583 end if;
584 end if;
585
586 Set_Component_Bit_Offset (Comp, Pos * SSU + NFB);
587 Set_Normalized_First_Bit (Comp, NFB mod SSU);
588 end;
589 end loop;
590 end loop;
591 end Sort_CC;
592 end;
593 end case;
59ac57b5 594 end Adjust_Record_For_Reverse_Bit_Order;
595
d6f39728 596 --------------------------------------
597 -- Alignment_Check_For_Esize_Change --
598 --------------------------------------
599
600 procedure Alignment_Check_For_Esize_Change (Typ : Entity_Id) is
601 begin
602 -- If the alignment is known, and not set by a rep clause, and is
603 -- inconsistent with the size being set, then reset it to unknown,
604 -- we assume in this case that the size overrides the inherited
605 -- alignment, and that the alignment must be recomputed.
606
607 if Known_Alignment (Typ)
608 and then not Has_Alignment_Clause (Typ)
609 and then Esize (Typ) mod (Alignment (Typ) * SSU) /= 0
610 then
611 Init_Alignment (Typ);
612 end if;
613 end Alignment_Check_For_Esize_Change;
614
615 -----------------------
616 -- Analyze_At_Clause --
617 -----------------------
618
619 -- An at clause is replaced by the corresponding Address attribute
620 -- definition clause that is the preferred approach in Ada 95.
621
622 procedure Analyze_At_Clause (N : Node_Id) is
177675a7 623 CS : constant Boolean := Comes_From_Source (N);
624
d6f39728 625 begin
177675a7 626 -- This is an obsolescent feature
627
e0521a36 628 Check_Restriction (No_Obsolescent_Features, N);
629
9dfe12ae 630 if Warn_On_Obsolescent_Feature then
631 Error_Msg_N
fbc67f84 632 ("at clause is an obsolescent feature (RM J.7(2))?", N);
9dfe12ae 633 Error_Msg_N
d53a018a 634 ("\use address attribute definition clause instead?", N);
9dfe12ae 635 end if;
636
177675a7 637 -- Rewrite as address clause
638
d6f39728 639 Rewrite (N,
640 Make_Attribute_Definition_Clause (Sloc (N),
641 Name => Identifier (N),
642 Chars => Name_Address,
643 Expression => Expression (N)));
177675a7 644
645 -- We preserve Comes_From_Source, since logically the clause still
646 -- comes from the source program even though it is changed in form.
647
648 Set_Comes_From_Source (N, CS);
649
650 -- Analyze rewritten clause
651
d6f39728 652 Analyze_Attribute_Definition_Clause (N);
653 end Analyze_At_Clause;
654
655 -----------------------------------------
656 -- Analyze_Attribute_Definition_Clause --
657 -----------------------------------------
658
659 procedure Analyze_Attribute_Definition_Clause (N : Node_Id) is
660 Loc : constant Source_Ptr := Sloc (N);
661 Nam : constant Node_Id := Name (N);
662 Attr : constant Name_Id := Chars (N);
663 Expr : constant Node_Id := Expression (N);
664 Id : constant Attribute_Id := Get_Attribute_Id (Attr);
665 Ent : Entity_Id;
666 U_Ent : Entity_Id;
667
668 FOnly : Boolean := False;
669 -- Reset to True for subtype specific attribute (Alignment, Size)
670 -- and for stream attributes, i.e. those cases where in the call
671 -- to Rep_Item_Too_Late, FOnly is set True so that only the freezing
672 -- rules are checked. Note that the case of stream attributes is not
673 -- clear from the RM, but see AI95-00137. Also, the RM seems to
674 -- disallow Storage_Size for derived task types, but that is also
675 -- clearly unintentional.
676
9f373bb8 677 procedure Analyze_Stream_TSS_Definition (TSS_Nam : TSS_Name_Type);
678 -- Common processing for 'Read, 'Write, 'Input and 'Output attribute
679 -- definition clauses.
680
177675a7 681 -----------------------------------
682 -- Analyze_Stream_TSS_Definition --
683 -----------------------------------
684
9f373bb8 685 procedure Analyze_Stream_TSS_Definition (TSS_Nam : TSS_Name_Type) is
686 Subp : Entity_Id := Empty;
687 I : Interp_Index;
688 It : Interp;
689 Pnam : Entity_Id;
690
691 Is_Read : constant Boolean := (TSS_Nam = TSS_Stream_Read);
692
693 function Has_Good_Profile (Subp : Entity_Id) return Boolean;
694 -- Return true if the entity is a subprogram with an appropriate
695 -- profile for the attribute being defined.
696
697 ----------------------
698 -- Has_Good_Profile --
699 ----------------------
700
701 function Has_Good_Profile (Subp : Entity_Id) return Boolean is
702 F : Entity_Id;
703 Is_Function : constant Boolean := (TSS_Nam = TSS_Stream_Input);
704 Expected_Ekind : constant array (Boolean) of Entity_Kind :=
705 (False => E_Procedure, True => E_Function);
706 Typ : Entity_Id;
707
708 begin
709 if Ekind (Subp) /= Expected_Ekind (Is_Function) then
710 return False;
711 end if;
712
713 F := First_Formal (Subp);
714
715 if No (F)
716 or else Ekind (Etype (F)) /= E_Anonymous_Access_Type
717 or else Designated_Type (Etype (F)) /=
718 Class_Wide_Type (RTE (RE_Root_Stream_Type))
719 then
720 return False;
721 end if;
722
723 if not Is_Function then
724 Next_Formal (F);
725
726 declare
727 Expected_Mode : constant array (Boolean) of Entity_Kind :=
728 (False => E_In_Parameter,
729 True => E_Out_Parameter);
730 begin
731 if Parameter_Mode (F) /= Expected_Mode (Is_Read) then
732 return False;
733 end if;
734 end;
735
736 Typ := Etype (F);
737
738 else
739 Typ := Etype (Subp);
740 end if;
741
742 return Base_Type (Typ) = Base_Type (Ent)
743 and then No (Next_Formal (F));
9f373bb8 744 end Has_Good_Profile;
745
746 -- Start of processing for Analyze_Stream_TSS_Definition
747
748 begin
749 FOnly := True;
750
751 if not Is_Type (U_Ent) then
752 Error_Msg_N ("local name must be a subtype", Nam);
753 return;
754 end if;
755
756 Pnam := TSS (Base_Type (U_Ent), TSS_Nam);
757
44e4341e 758 -- If Pnam is present, it can be either inherited from an ancestor
759 -- type (in which case it is legal to redefine it for this type), or
760 -- be a previous definition of the attribute for the same type (in
761 -- which case it is illegal).
762
763 -- In the first case, it will have been analyzed already, and we
764 -- can check that its profile does not match the expected profile
765 -- for a stream attribute of U_Ent. In the second case, either Pnam
766 -- has been analyzed (and has the expected profile), or it has not
767 -- been analyzed yet (case of a type that has not been frozen yet
768 -- and for which the stream attribute has been set using Set_TSS).
769
770 if Present (Pnam)
771 and then (No (First_Entity (Pnam)) or else Has_Good_Profile (Pnam))
772 then
9f373bb8 773 Error_Msg_Sloc := Sloc (Pnam);
774 Error_Msg_Name_1 := Attr;
775 Error_Msg_N ("% attribute already defined #", Nam);
776 return;
777 end if;
778
779 Analyze (Expr);
780
781 if Is_Entity_Name (Expr) then
782 if not Is_Overloaded (Expr) then
783 if Has_Good_Profile (Entity (Expr)) then
784 Subp := Entity (Expr);
785 end if;
786
787 else
788 Get_First_Interp (Expr, I, It);
9f373bb8 789 while Present (It.Nam) loop
790 if Has_Good_Profile (It.Nam) then
791 Subp := It.Nam;
792 exit;
793 end if;
794
795 Get_Next_Interp (I, It);
796 end loop;
797 end if;
798 end if;
799
800 if Present (Subp) then
59ac57b5 801 if Is_Abstract_Subprogram (Subp) then
9f373bb8 802 Error_Msg_N ("stream subprogram must not be abstract", Expr);
803 return;
804 end if;
805
806 Set_Entity (Expr, Subp);
807 Set_Etype (Expr, Etype (Subp));
808
44e4341e 809 New_Stream_Subprogram (N, U_Ent, Subp, TSS_Nam);
9f373bb8 810
811 else
812 Error_Msg_Name_1 := Attr;
813 Error_Msg_N ("incorrect expression for% attribute", Expr);
814 end if;
815 end Analyze_Stream_TSS_Definition;
816
817 -- Start of processing for Analyze_Attribute_Definition_Clause
818
d6f39728 819 begin
eef1ca1e 820 -- Process Ignore_Rep_Clauses option
821
fbc67f84 822 if Ignore_Rep_Clauses then
9d627c41 823 case Id is
824
eef1ca1e 825 -- The following should be ignored. They do not affect legality
826 -- and may be target dependent. The basic idea of -gnatI is to
827 -- ignore any rep clauses that may be target dependent but do not
828 -- affect legality (except possibly to be rejected because they
829 -- are incompatible with the compilation target).
9d627c41 830
2f1aac99 831 when Attribute_Alignment |
9d627c41 832 Attribute_Bit_Order |
833 Attribute_Component_Size |
834 Attribute_Machine_Radix |
835 Attribute_Object_Size |
836 Attribute_Size |
837 Attribute_Small |
838 Attribute_Stream_Size |
839 Attribute_Value_Size =>
840
841 Rewrite (N, Make_Null_Statement (Sloc (N)));
842 return;
843
eef1ca1e 844 -- The following should not be ignored, because in the first place
845 -- they are reasonably portable, and should not cause problems in
846 -- compiling code from another target, and also they do affect
847 -- legality, e.g. failing to provide a stream attribute for a
848 -- type may make a program illegal.
9d627c41 849
850 when Attribute_External_Tag |
851 Attribute_Input |
852 Attribute_Output |
853 Attribute_Read |
854 Attribute_Storage_Pool |
855 Attribute_Storage_Size |
856 Attribute_Write =>
857 null;
858
859 -- Other cases are errors, which will be caught below
860
861 when others =>
862 null;
863 end case;
fbc67f84 864 end if;
865
d6f39728 866 Analyze (Nam);
867 Ent := Entity (Nam);
868
869 if Rep_Item_Too_Early (Ent, N) then
870 return;
871 end if;
872
9f373bb8 873 -- Rep clause applies to full view of incomplete type or private type if
874 -- we have one (if not, this is a premature use of the type). However,
875 -- certain semantic checks need to be done on the specified entity (i.e.
876 -- the private view), so we save it in Ent.
d6f39728 877
878 if Is_Private_Type (Ent)
879 and then Is_Derived_Type (Ent)
880 and then not Is_Tagged_Type (Ent)
881 and then No (Full_View (Ent))
882 then
9f373bb8 883 -- If this is a private type whose completion is a derivation from
884 -- another private type, there is no full view, and the attribute
885 -- belongs to the type itself, not its underlying parent.
d6f39728 886
887 U_Ent := Ent;
888
889 elsif Ekind (Ent) = E_Incomplete_Type then
d5b349fa 890
9f373bb8 891 -- The attribute applies to the full view, set the entity of the
892 -- attribute definition accordingly.
d5b349fa 893
d6f39728 894 Ent := Underlying_Type (Ent);
895 U_Ent := Ent;
d5b349fa 896 Set_Entity (Nam, Ent);
897
d6f39728 898 else
899 U_Ent := Underlying_Type (Ent);
900 end if;
901
902 -- Complete other routine error checks
903
904 if Etype (Nam) = Any_Type then
905 return;
906
907 elsif Scope (Ent) /= Current_Scope then
908 Error_Msg_N ("entity must be declared in this scope", Nam);
909 return;
910
f15731c4 911 elsif No (U_Ent) then
912 U_Ent := Ent;
913
d6f39728 914 elsif Is_Type (U_Ent)
915 and then not Is_First_Subtype (U_Ent)
916 and then Id /= Attribute_Object_Size
917 and then Id /= Attribute_Value_Size
918 and then not From_At_Mod (N)
919 then
920 Error_Msg_N ("cannot specify attribute for subtype", Nam);
921 return;
d6f39728 922 end if;
923
924 -- Switch on particular attribute
925
926 case Id is
927
928 -------------
929 -- Address --
930 -------------
931
932 -- Address attribute definition clause
933
934 when Attribute_Address => Address : begin
177675a7 935
936 -- A little error check, catch for X'Address use X'Address;
937
938 if Nkind (Nam) = N_Identifier
939 and then Nkind (Expr) = N_Attribute_Reference
940 and then Attribute_Name (Expr) = Name_Address
941 and then Nkind (Prefix (Expr)) = N_Identifier
942 and then Chars (Nam) = Chars (Prefix (Expr))
943 then
944 Error_Msg_NE
945 ("address for & is self-referencing", Prefix (Expr), Ent);
946 return;
947 end if;
948
949 -- Not that special case, carry on with analysis of expression
950
d6f39728 951 Analyze_And_Resolve (Expr, RTE (RE_Address));
952
2f1aac99 953 -- Even when ignoring rep clauses we need to indicate that the
954 -- entity has an address clause and thus it is legal to declare
955 -- it imported.
956
957 if Ignore_Rep_Clauses then
d3ef794c 958 if Ekind_In (U_Ent, E_Variable, E_Constant) then
2f1aac99 959 Record_Rep_Item (U_Ent, N);
960 end if;
961
962 return;
963 end if;
964
d6f39728 965 if Present (Address_Clause (U_Ent)) then
966 Error_Msg_N ("address already given for &", Nam);
967
968 -- Case of address clause for subprogram
969
970 elsif Is_Subprogram (U_Ent) then
d6f39728 971 if Has_Homonym (U_Ent) then
972 Error_Msg_N
973 ("address clause cannot be given " &
974 "for overloaded subprogram",
975 Nam);
83f8f0a6 976 return;
d6f39728 977 end if;
978
83f8f0a6 979 -- For subprograms, all address clauses are permitted, and we
980 -- mark the subprogram as having a deferred freeze so that Gigi
981 -- will not elaborate it too soon.
d6f39728 982
983 -- Above needs more comments, what is too soon about???
984
985 Set_Has_Delayed_Freeze (U_Ent);
986
987 -- Case of address clause for entry
988
989 elsif Ekind (U_Ent) = E_Entry then
d6f39728 990 if Nkind (Parent (N)) = N_Task_Body then
991 Error_Msg_N
992 ("entry address must be specified in task spec", Nam);
83f8f0a6 993 return;
d6f39728 994 end if;
995
996 -- For entries, we require a constant address
997
998 Check_Constant_Address_Clause (Expr, U_Ent);
999
83f8f0a6 1000 -- Special checks for task types
1001
f15731c4 1002 if Is_Task_Type (Scope (U_Ent))
1003 and then Comes_From_Source (Scope (U_Ent))
1004 then
1005 Error_Msg_N
1006 ("?entry address declared for entry in task type", N);
1007 Error_Msg_N
1008 ("\?only one task can be declared of this type", N);
1009 end if;
1010
83f8f0a6 1011 -- Entry address clauses are obsolescent
1012
e0521a36 1013 Check_Restriction (No_Obsolescent_Features, N);
1014
9dfe12ae 1015 if Warn_On_Obsolescent_Feature then
1016 Error_Msg_N
1017 ("attaching interrupt to task entry is an " &
fbc67f84 1018 "obsolescent feature (RM J.7.1)?", N);
9dfe12ae 1019 Error_Msg_N
d53a018a 1020 ("\use interrupt procedure instead?", N);
9dfe12ae 1021 end if;
1022
83f8f0a6 1023 -- Case of an address clause for a controlled object which we
1024 -- consider to be erroneous.
9dfe12ae 1025
83f8f0a6 1026 elsif Is_Controlled (Etype (U_Ent))
1027 or else Has_Controlled_Component (Etype (U_Ent))
1028 then
9dfe12ae 1029 Error_Msg_NE
1030 ("?controlled object& must not be overlaid", Nam, U_Ent);
1031 Error_Msg_N
1032 ("\?Program_Error will be raised at run time", Nam);
1033 Insert_Action (Declaration_Node (U_Ent),
1034 Make_Raise_Program_Error (Loc,
1035 Reason => PE_Overlaid_Controlled_Object));
83f8f0a6 1036 return;
9dfe12ae 1037
1038 -- Case of address clause for a (non-controlled) object
d6f39728 1039
1040 elsif
1041 Ekind (U_Ent) = E_Variable
1042 or else
1043 Ekind (U_Ent) = E_Constant
1044 then
1045 declare
d6da7448 1046 Expr : constant Node_Id := Expression (N);
1047 O_Ent : Entity_Id;
1048 Off : Boolean;
d6f39728 1049
1050 begin
7ee315cc 1051 -- Exported variables cannot have an address clause, because
1052 -- this cancels the effect of the pragma Export.
d6f39728 1053
1054 if Is_Exported (U_Ent) then
1055 Error_Msg_N
1056 ("cannot export object with address clause", Nam);
83f8f0a6 1057 return;
d6da7448 1058 end if;
1059
1060 Find_Overlaid_Entity (N, O_Ent, Off);
d6f39728 1061
9dfe12ae 1062 -- Overlaying controlled objects is erroneous
1063
d6da7448 1064 if Present (O_Ent)
1065 and then (Has_Controlled_Component (Etype (O_Ent))
1066 or else Is_Controlled (Etype (O_Ent)))
9dfe12ae 1067 then
1068 Error_Msg_N
83f8f0a6 1069 ("?cannot overlay with controlled object", Expr);
9dfe12ae 1070 Error_Msg_N
1071 ("\?Program_Error will be raised at run time", Expr);
1072 Insert_Action (Declaration_Node (U_Ent),
1073 Make_Raise_Program_Error (Loc,
1074 Reason => PE_Overlaid_Controlled_Object));
83f8f0a6 1075 return;
9dfe12ae 1076
d6da7448 1077 elsif Present (O_Ent)
9dfe12ae 1078 and then Ekind (U_Ent) = E_Constant
d6da7448 1079 and then not Is_Constant_Object (O_Ent)
9dfe12ae 1080 then
1081 Error_Msg_N ("constant overlays a variable?", Expr);
1082
1083 elsif Present (Renamed_Object (U_Ent)) then
1084 Error_Msg_N
1085 ("address clause not allowed"
fbc67f84 1086 & " for a renaming declaration (RM 13.1(6))", Nam);
83f8f0a6 1087 return;
9dfe12ae 1088
d6f39728 1089 -- Imported variables can have an address clause, but then
1090 -- the import is pretty meaningless except to suppress
1091 -- initializations, so we do not need such variables to
1092 -- be statically allocated (and in fact it causes trouble
1093 -- if the address clause is a local value).
1094
1095 elsif Is_Imported (U_Ent) then
1096 Set_Is_Statically_Allocated (U_Ent, False);
1097 end if;
1098
1099 -- We mark a possible modification of a variable with an
1100 -- address clause, since it is likely aliasing is occurring.
1101
177675a7 1102 Note_Possible_Modification (Nam, Sure => False);
d6f39728 1103
83f8f0a6 1104 -- Here we are checking for explicit overlap of one variable
1105 -- by another, and if we find this then mark the overlapped
1106 -- variable as also being volatile to prevent unwanted
d6da7448 1107 -- optimizations. This is a significant pessimization so
1108 -- avoid it when there is an offset, i.e. when the object
1109 -- is composite; they cannot be optimized easily anyway.
d6f39728 1110
d6da7448 1111 if Present (O_Ent)
1112 and then Is_Object (O_Ent)
1113 and then not Off
1114 then
1115 Set_Treat_As_Volatile (O_Ent);
d6f39728 1116 end if;
1117
9dfe12ae 1118 -- Legality checks on the address clause for initialized
1119 -- objects is deferred until the freeze point, because
1120 -- a subsequent pragma might indicate that the object is
1121 -- imported and thus not initialized.
1122
1123 Set_Has_Delayed_Freeze (U_Ent);
1124
51ad5ad2 1125 -- If an initialization call has been generated for this
1126 -- object, it needs to be deferred to after the freeze node
1127 -- we have just now added, otherwise GIGI will see a
1128 -- reference to the variable (as actual to the IP call)
1129 -- before its definition.
1130
1131 declare
1132 Init_Call : constant Node_Id := Find_Init_Call (U_Ent, N);
1133 begin
1134 if Present (Init_Call) then
1135 Remove (Init_Call);
1136 Append_Freeze_Action (U_Ent, Init_Call);
1137 end if;
1138 end;
1139
d6f39728 1140 if Is_Exported (U_Ent) then
1141 Error_Msg_N
1142 ("& cannot be exported if an address clause is given",
1143 Nam);
1144 Error_Msg_N
1145 ("\define and export a variable " &
1146 "that holds its address instead",
1147 Nam);
1148 end if;
1149
44e4341e 1150 -- Entity has delayed freeze, so we will generate an
1151 -- alignment check at the freeze point unless suppressed.
d6f39728 1152
44e4341e 1153 if not Range_Checks_Suppressed (U_Ent)
1154 and then not Alignment_Checks_Suppressed (U_Ent)
1155 then
1156 Set_Check_Address_Alignment (N);
1157 end if;
d6f39728 1158
1159 -- Kill the size check code, since we are not allocating
1160 -- the variable, it is somewhere else.
1161
1162 Kill_Size_Check_Code (U_Ent);
83f8f0a6 1163
d6da7448 1164 -- If the address clause is of the form:
83f8f0a6 1165
d6da7448 1166 -- for Y'Address use X'Address
83f8f0a6 1167
d6da7448 1168 -- or
83f8f0a6 1169
d6da7448 1170 -- Const : constant Address := X'Address;
1171 -- ...
1172 -- for Y'Address use Const;
83f8f0a6 1173
d6da7448 1174 -- then we make an entry in the table for checking the size
1175 -- and alignment of the overlaying variable. We defer this
1176 -- check till after code generation to take full advantage
1177 -- of the annotation done by the back end. This entry is
1178 -- only made if the address clause comes from source.
9474aa9c 1179 -- If the entity has a generic type, the check will be
43dd6937 1180 -- performed in the instance if the actual type justifies
1181 -- it, and we do not insert the clause in the table to
1182 -- prevent spurious warnings.
83f8f0a6 1183
d6da7448 1184 if Address_Clause_Overlay_Warnings
1185 and then Comes_From_Source (N)
1186 and then Present (O_Ent)
1187 and then Is_Object (O_Ent)
1188 then
9474aa9c 1189 if not Is_Generic_Type (Etype (U_Ent)) then
1190 Address_Clause_Checks.Append ((N, U_Ent, O_Ent, Off));
1191 end if;
177675a7 1192
d6da7448 1193 -- If variable overlays a constant view, and we are
1194 -- warning on overlays, then mark the variable as
1195 -- overlaying a constant (we will give warnings later
1196 -- if this variable is assigned).
177675a7 1197
d6da7448 1198 if Is_Constant_Object (O_Ent)
1199 and then Ekind (U_Ent) = E_Variable
1200 then
1201 Set_Overlays_Constant (U_Ent);
83f8f0a6 1202 end if;
d6da7448 1203 end if;
1204 end;
83f8f0a6 1205
d6f39728 1206 -- Not a valid entity for an address clause
1207
1208 else
1209 Error_Msg_N ("address cannot be given for &", Nam);
1210 end if;
1211 end Address;
1212
1213 ---------------
1214 -- Alignment --
1215 ---------------
1216
1217 -- Alignment attribute definition clause
1218
b47769f0 1219 when Attribute_Alignment => Alignment : declare
9dfe12ae 1220 Align : constant Uint := Get_Alignment_Value (Expr);
d6f39728 1221
1222 begin
1223 FOnly := True;
1224
1225 if not Is_Type (U_Ent)
1226 and then Ekind (U_Ent) /= E_Variable
1227 and then Ekind (U_Ent) /= E_Constant
1228 then
1229 Error_Msg_N ("alignment cannot be given for &", Nam);
1230
1231 elsif Has_Alignment_Clause (U_Ent) then
1232 Error_Msg_Sloc := Sloc (Alignment_Clause (U_Ent));
1233 Error_Msg_N ("alignment clause previously given#", N);
1234
1235 elsif Align /= No_Uint then
1236 Set_Has_Alignment_Clause (U_Ent);
1237 Set_Alignment (U_Ent, Align);
b47769f0 1238
1239 -- For an array type, U_Ent is the first subtype. In that case,
1240 -- also set the alignment of the anonymous base type so that
1241 -- other subtypes (such as the itypes for aggregates of the
1242 -- type) also receive the expected alignment.
1243
1244 if Is_Array_Type (U_Ent) then
1245 Set_Alignment (Base_Type (U_Ent), Align);
1246 end if;
d6f39728 1247 end if;
b47769f0 1248 end Alignment;
d6f39728 1249
1250 ---------------
1251 -- Bit_Order --
1252 ---------------
1253
1254 -- Bit_Order attribute definition clause
1255
1256 when Attribute_Bit_Order => Bit_Order : declare
1257 begin
1258 if not Is_Record_Type (U_Ent) then
1259 Error_Msg_N
1260 ("Bit_Order can only be defined for record type", Nam);
1261
1262 else
1263 Analyze_And_Resolve (Expr, RTE (RE_Bit_Order));
1264
1265 if Etype (Expr) = Any_Type then
1266 return;
1267
1268 elsif not Is_Static_Expression (Expr) then
9dfe12ae 1269 Flag_Non_Static_Expr
1270 ("Bit_Order requires static expression!", Expr);
d6f39728 1271
1272 else
1273 if (Expr_Value (Expr) = 0) /= Bytes_Big_Endian then
1274 Set_Reverse_Bit_Order (U_Ent, True);
1275 end if;
1276 end if;
1277 end if;
1278 end Bit_Order;
1279
1280 --------------------
1281 -- Component_Size --
1282 --------------------
1283
1284 -- Component_Size attribute definition clause
1285
1286 when Attribute_Component_Size => Component_Size_Case : declare
1287 Csize : constant Uint := Static_Integer (Expr);
1288 Btype : Entity_Id;
1289 Biased : Boolean;
1290 New_Ctyp : Entity_Id;
1291 Decl : Node_Id;
1292
1293 begin
1294 if not Is_Array_Type (U_Ent) then
1295 Error_Msg_N ("component size requires array type", Nam);
1296 return;
1297 end if;
1298
1299 Btype := Base_Type (U_Ent);
1300
1301 if Has_Component_Size_Clause (Btype) then
1302 Error_Msg_N
3062c401 1303 ("component size clause for& previously given", Nam);
d6f39728 1304
1305 elsif Csize /= No_Uint then
1306 Check_Size (Expr, Component_Type (Btype), Csize, Biased);
1307
1308 if Has_Aliased_Components (Btype)
1309 and then Csize < 32
1310 and then Csize /= 8
1311 and then Csize /= 16
1312 then
1313 Error_Msg_N
1314 ("component size incorrect for aliased components", N);
1315 return;
1316 end if;
1317
1318 -- For the biased case, build a declaration for a subtype
1319 -- that will be used to represent the biased subtype that
1320 -- reflects the biased representation of components. We need
1321 -- this subtype to get proper conversions on referencing
3062c401 1322 -- elements of the array. Note that component size clauses
1323 -- are ignored in VM mode.
1324
1325 if VM_Target = No_VM then
1326 if Biased then
1327 New_Ctyp :=
1328 Make_Defining_Identifier (Loc,
1329 Chars =>
1330 New_External_Name (Chars (U_Ent), 'C', 0, 'T'));
1331
1332 Decl :=
1333 Make_Subtype_Declaration (Loc,
1334 Defining_Identifier => New_Ctyp,
1335 Subtype_Indication =>
1336 New_Occurrence_Of (Component_Type (Btype), Loc));
1337
1338 Set_Parent (Decl, N);
1339 Analyze (Decl, Suppress => All_Checks);
1340
1341 Set_Has_Delayed_Freeze (New_Ctyp, False);
1342 Set_Esize (New_Ctyp, Csize);
1343 Set_RM_Size (New_Ctyp, Csize);
1344 Init_Alignment (New_Ctyp);
1345 Set_Has_Biased_Representation (New_Ctyp, True);
1346 Set_Is_Itype (New_Ctyp, True);
1347 Set_Associated_Node_For_Itype (New_Ctyp, U_Ent);
1348
1349 Set_Component_Type (Btype, New_Ctyp);
cc46ff4b 1350
1351 if Warn_On_Biased_Representation then
1352 Error_Msg_N
1353 ("?component size clause forces biased "
1354 & "representation", N);
1355 end if;
3062c401 1356 end if;
1357
1358 Set_Component_Size (Btype, Csize);
1359
1360 -- For VM case, we ignore component size clauses
1361
1362 else
1363 -- Give a warning unless we are in GNAT mode, in which case
1364 -- the warning is suppressed since it is not useful.
1365
1366 if not GNAT_Mode then
1367 Error_Msg_N
1368 ("?component size ignored in this configuration", N);
1369 end if;
d6f39728 1370 end if;
1371
d6f39728 1372 Set_Has_Component_Size_Clause (Btype, True);
1373 Set_Has_Non_Standard_Rep (Btype, True);
1374 end if;
1375 end Component_Size_Case;
1376
1377 ------------------
1378 -- External_Tag --
1379 ------------------
1380
1381 when Attribute_External_Tag => External_Tag :
1382 begin
1383 if not Is_Tagged_Type (U_Ent) then
1384 Error_Msg_N ("should be a tagged type", Nam);
1385 end if;
1386
1387 Analyze_And_Resolve (Expr, Standard_String);
1388
1389 if not Is_Static_Expression (Expr) then
9dfe12ae 1390 Flag_Non_Static_Expr
1391 ("static string required for tag name!", Nam);
d6f39728 1392 end if;
1393
15ebb600 1394 if VM_Target = No_VM then
1395 Set_Has_External_Tag_Rep_Clause (U_Ent);
9af0ddc7 1396 else
15ebb600 1397 Error_Msg_Name_1 := Attr;
1398 Error_Msg_N
1399 ("% attribute unsupported in this configuration", Nam);
1400 end if;
fbc67f84 1401
1402 if not Is_Library_Level_Entity (U_Ent) then
1403 Error_Msg_NE
1404 ("?non-unique external tag supplied for &", N, U_Ent);
1405 Error_Msg_N
1406 ("?\same external tag applies to all subprogram calls", N);
1407 Error_Msg_N
1408 ("?\corresponding internal tag cannot be obtained", N);
1409 end if;
d6f39728 1410 end External_Tag;
1411
1412 -----------
1413 -- Input --
1414 -----------
1415
9f373bb8 1416 when Attribute_Input =>
1417 Analyze_Stream_TSS_Definition (TSS_Stream_Input);
1418 Set_Has_Specified_Stream_Input (Ent);
d6f39728 1419
1420 -------------------
1421 -- Machine_Radix --
1422 -------------------
1423
1424 -- Machine radix attribute definition clause
1425
1426 when Attribute_Machine_Radix => Machine_Radix : declare
1427 Radix : constant Uint := Static_Integer (Expr);
1428
1429 begin
1430 if not Is_Decimal_Fixed_Point_Type (U_Ent) then
1431 Error_Msg_N ("decimal fixed-point type expected for &", Nam);
1432
1433 elsif Has_Machine_Radix_Clause (U_Ent) then
1434 Error_Msg_Sloc := Sloc (Alignment_Clause (U_Ent));
1435 Error_Msg_N ("machine radix clause previously given#", N);
1436
1437 elsif Radix /= No_Uint then
1438 Set_Has_Machine_Radix_Clause (U_Ent);
1439 Set_Has_Non_Standard_Rep (Base_Type (U_Ent));
1440
1441 if Radix = 2 then
1442 null;
1443 elsif Radix = 10 then
1444 Set_Machine_Radix_10 (U_Ent);
1445 else
1446 Error_Msg_N ("machine radix value must be 2 or 10", Expr);
1447 end if;
1448 end if;
1449 end Machine_Radix;
1450
1451 -----------------
1452 -- Object_Size --
1453 -----------------
1454
1455 -- Object_Size attribute definition clause
1456
1457 when Attribute_Object_Size => Object_Size : declare
bfa5a9d9 1458 Size : constant Uint := Static_Integer (Expr);
1459
d6f39728 1460 Biased : Boolean;
bfa5a9d9 1461 pragma Warnings (Off, Biased);
d6f39728 1462
1463 begin
1464 if not Is_Type (U_Ent) then
1465 Error_Msg_N ("Object_Size cannot be given for &", Nam);
1466
1467 elsif Has_Object_Size_Clause (U_Ent) then
1468 Error_Msg_N ("Object_Size already given for &", Nam);
1469
1470 else
1471 Check_Size (Expr, U_Ent, Size, Biased);
1472
1473 if Size /= 8
1474 and then
1475 Size /= 16
1476 and then
1477 Size /= 32
1478 and then
1479 UI_Mod (Size, 64) /= 0
1480 then
1481 Error_Msg_N
1482 ("Object_Size must be 8, 16, 32, or multiple of 64",
1483 Expr);
1484 end if;
1485
1486 Set_Esize (U_Ent, Size);
1487 Set_Has_Object_Size_Clause (U_Ent);
1488 Alignment_Check_For_Esize_Change (U_Ent);
1489 end if;
1490 end Object_Size;
1491
1492 ------------
1493 -- Output --
1494 ------------
1495
9f373bb8 1496 when Attribute_Output =>
1497 Analyze_Stream_TSS_Definition (TSS_Stream_Output);
1498 Set_Has_Specified_Stream_Output (Ent);
d6f39728 1499
1500 ----------
1501 -- Read --
1502 ----------
1503
9f373bb8 1504 when Attribute_Read =>
1505 Analyze_Stream_TSS_Definition (TSS_Stream_Read);
1506 Set_Has_Specified_Stream_Read (Ent);
d6f39728 1507
1508 ----------
1509 -- Size --
1510 ----------
1511
1512 -- Size attribute definition clause
1513
1514 when Attribute_Size => Size : declare
1515 Size : constant Uint := Static_Integer (Expr);
1516 Etyp : Entity_Id;
1517 Biased : Boolean;
1518
1519 begin
1520 FOnly := True;
1521
1522 if Has_Size_Clause (U_Ent) then
1523 Error_Msg_N ("size already given for &", Nam);
1524
1525 elsif not Is_Type (U_Ent)
1526 and then Ekind (U_Ent) /= E_Variable
1527 and then Ekind (U_Ent) /= E_Constant
1528 then
1529 Error_Msg_N ("size cannot be given for &", Nam);
1530
1531 elsif Is_Array_Type (U_Ent)
1532 and then not Is_Constrained (U_Ent)
1533 then
1534 Error_Msg_N
1535 ("size cannot be given for unconstrained array", Nam);
1536
1537 elsif Size /= No_Uint then
d6f39728 1538 if Is_Type (U_Ent) then
1539 Etyp := U_Ent;
1540 else
1541 Etyp := Etype (U_Ent);
1542 end if;
1543
59ac57b5 1544 -- Check size, note that Gigi is in charge of checking that the
1545 -- size of an array or record type is OK. Also we do not check
1546 -- the size in the ordinary fixed-point case, since it is too
1547 -- early to do so (there may be subsequent small clause that
1548 -- affects the size). We can check the size if a small clause
1549 -- has already been given.
d6f39728 1550
1551 if not Is_Ordinary_Fixed_Point_Type (U_Ent)
1552 or else Has_Small_Clause (U_Ent)
1553 then
1554 Check_Size (Expr, Etyp, Size, Biased);
cc46ff4b 1555 Set_Has_Biased_Representation (U_Ent, Biased);
1556
1557 if Biased and Warn_On_Biased_Representation then
1558 Error_Msg_N
1559 ("?size clause forces biased representation", N);
1560 end if;
d6f39728 1561 end if;
1562
1563 -- For types set RM_Size and Esize if possible
1564
1565 if Is_Type (U_Ent) then
1566 Set_RM_Size (U_Ent, Size);
1567
59ac57b5 1568 -- For scalar types, increase Object_Size to power of 2, but
1569 -- not less than a storage unit in any case (i.e., normally
1570 -- this means it will be byte addressable).
d6f39728 1571
1572 if Is_Scalar_Type (U_Ent) then
f15731c4 1573 if Size <= System_Storage_Unit then
1574 Init_Esize (U_Ent, System_Storage_Unit);
d6f39728 1575 elsif Size <= 16 then
1576 Init_Esize (U_Ent, 16);
1577 elsif Size <= 32 then
1578 Init_Esize (U_Ent, 32);
1579 else
1580 Set_Esize (U_Ent, (Size + 63) / 64 * 64);
1581 end if;
1582
1583 -- For all other types, object size = value size. The
1584 -- backend will adjust as needed.
1585
1586 else
1587 Set_Esize (U_Ent, Size);
1588 end if;
1589
1590 Alignment_Check_For_Esize_Change (U_Ent);
1591
1592 -- For objects, set Esize only
1593
1594 else
9dfe12ae 1595 if Is_Elementary_Type (Etyp) then
1596 if Size /= System_Storage_Unit
1597 and then
1598 Size /= System_Storage_Unit * 2
1599 and then
1600 Size /= System_Storage_Unit * 4
1601 and then
1602 Size /= System_Storage_Unit * 8
1603 then
5c99c290 1604 Error_Msg_Uint_1 := UI_From_Int (System_Storage_Unit);
87d5c1d0 1605 Error_Msg_Uint_2 := Error_Msg_Uint_1 * 8;
9dfe12ae 1606 Error_Msg_N
5c99c290 1607 ("size for primitive object must be a power of 2"
87d5c1d0 1608 & " in the range ^-^", N);
9dfe12ae 1609 end if;
1610 end if;
1611
d6f39728 1612 Set_Esize (U_Ent, Size);
1613 end if;
1614
1615 Set_Has_Size_Clause (U_Ent);
1616 end if;
1617 end Size;
1618
1619 -----------
1620 -- Small --
1621 -----------
1622
1623 -- Small attribute definition clause
1624
1625 when Attribute_Small => Small : declare
1626 Implicit_Base : constant Entity_Id := Base_Type (U_Ent);
1627 Small : Ureal;
1628
1629 begin
1630 Analyze_And_Resolve (Expr, Any_Real);
1631
1632 if Etype (Expr) = Any_Type then
1633 return;
1634
1635 elsif not Is_Static_Expression (Expr) then
9dfe12ae 1636 Flag_Non_Static_Expr
1637 ("small requires static expression!", Expr);
d6f39728 1638 return;
1639
1640 else
1641 Small := Expr_Value_R (Expr);
1642
1643 if Small <= Ureal_0 then
1644 Error_Msg_N ("small value must be greater than zero", Expr);
1645 return;
1646 end if;
1647
1648 end if;
1649
1650 if not Is_Ordinary_Fixed_Point_Type (U_Ent) then
1651 Error_Msg_N
1652 ("small requires an ordinary fixed point type", Nam);
1653
1654 elsif Has_Small_Clause (U_Ent) then
1655 Error_Msg_N ("small already given for &", Nam);
1656
1657 elsif Small > Delta_Value (U_Ent) then
1658 Error_Msg_N
1659 ("small value must not be greater then delta value", Nam);
1660
1661 else
1662 Set_Small_Value (U_Ent, Small);
1663 Set_Small_Value (Implicit_Base, Small);
1664 Set_Has_Small_Clause (U_Ent);
1665 Set_Has_Small_Clause (Implicit_Base);
1666 Set_Has_Non_Standard_Rep (Implicit_Base);
1667 end if;
1668 end Small;
1669
d6f39728 1670 ------------------
1671 -- Storage_Pool --
1672 ------------------
1673
1674 -- Storage_Pool attribute definition clause
1675
1676 when Attribute_Storage_Pool => Storage_Pool : declare
1677 Pool : Entity_Id;
6b567c71 1678 T : Entity_Id;
d6f39728 1679
1680 begin
44e4341e 1681 if Ekind (U_Ent) = E_Access_Subprogram_Type then
1682 Error_Msg_N
1683 ("storage pool cannot be given for access-to-subprogram type",
1684 Nam);
1685 return;
1686
d3ef794c 1687 elsif not
1688 Ekind_In (U_Ent, E_Access_Type, E_General_Access_Type)
d6f39728 1689 then
44e4341e 1690 Error_Msg_N
1691 ("storage pool can only be given for access types", Nam);
d6f39728 1692 return;
1693
1694 elsif Is_Derived_Type (U_Ent) then
1695 Error_Msg_N
1696 ("storage pool cannot be given for a derived access type",
1697 Nam);
1698
1699 elsif Has_Storage_Size_Clause (U_Ent) then
1700 Error_Msg_N ("storage size already given for &", Nam);
1701 return;
1702
1703 elsif Present (Associated_Storage_Pool (U_Ent)) then
1704 Error_Msg_N ("storage pool already given for &", Nam);
1705 return;
1706 end if;
1707
1708 Analyze_And_Resolve
1709 (Expr, Class_Wide_Type (RTE (RE_Root_Storage_Pool)));
1710
8c5c7277 1711 if not Denotes_Variable (Expr) then
1712 Error_Msg_N ("storage pool must be a variable", Expr);
1713 return;
1714 end if;
1715
6b567c71 1716 if Nkind (Expr) = N_Type_Conversion then
1717 T := Etype (Expression (Expr));
1718 else
1719 T := Etype (Expr);
1720 end if;
1721
1722 -- The Stack_Bounded_Pool is used internally for implementing
1723 -- access types with a Storage_Size. Since it only work
1724 -- properly when used on one specific type, we need to check
1a34e48c 1725 -- that it is not hijacked improperly:
6b567c71 1726 -- type T is access Integer;
1727 -- for T'Storage_Size use n;
1728 -- type Q is access Float;
1729 -- for Q'Storage_Size use T'Storage_Size; -- incorrect
1730
15ebb600 1731 if RTE_Available (RE_Stack_Bounded_Pool)
1732 and then Base_Type (T) = RTE (RE_Stack_Bounded_Pool)
1733 then
1734 Error_Msg_N ("non-shareable internal Pool", Expr);
6b567c71 1735 return;
1736 end if;
1737
d6f39728 1738 -- If the argument is a name that is not an entity name, then
1739 -- we construct a renaming operation to define an entity of
1740 -- type storage pool.
1741
1742 if not Is_Entity_Name (Expr)
1743 and then Is_Object_Reference (Expr)
1744 then
1745 Pool :=
1746 Make_Defining_Identifier (Loc,
1747 Chars => New_Internal_Name ('P'));
1748
1749 declare
1750 Rnode : constant Node_Id :=
1751 Make_Object_Renaming_Declaration (Loc,
1752 Defining_Identifier => Pool,
1753 Subtype_Mark =>
1754 New_Occurrence_Of (Etype (Expr), Loc),
1755 Name => Expr);
1756
1757 begin
1758 Insert_Before (N, Rnode);
1759 Analyze (Rnode);
1760 Set_Associated_Storage_Pool (U_Ent, Pool);
1761 end;
1762
1763 elsif Is_Entity_Name (Expr) then
1764 Pool := Entity (Expr);
1765
1766 -- If pool is a renamed object, get original one. This can
1767 -- happen with an explicit renaming, and within instances.
1768
1769 while Present (Renamed_Object (Pool))
1770 and then Is_Entity_Name (Renamed_Object (Pool))
1771 loop
1772 Pool := Entity (Renamed_Object (Pool));
1773 end loop;
1774
1775 if Present (Renamed_Object (Pool))
1776 and then Nkind (Renamed_Object (Pool)) = N_Type_Conversion
1777 and then Is_Entity_Name (Expression (Renamed_Object (Pool)))
1778 then
1779 Pool := Entity (Expression (Renamed_Object (Pool)));
1780 end if;
1781
6b567c71 1782 Set_Associated_Storage_Pool (U_Ent, Pool);
d6f39728 1783
1784 elsif Nkind (Expr) = N_Type_Conversion
1785 and then Is_Entity_Name (Expression (Expr))
1786 and then Nkind (Original_Node (Expr)) = N_Attribute_Reference
1787 then
1788 Pool := Entity (Expression (Expr));
6b567c71 1789 Set_Associated_Storage_Pool (U_Ent, Pool);
d6f39728 1790
1791 else
1792 Error_Msg_N ("incorrect reference to a Storage Pool", Expr);
1793 return;
1794 end if;
1795 end Storage_Pool;
1796
44e4341e 1797 ------------------
1798 -- Storage_Size --
1799 ------------------
1800
1801 -- Storage_Size attribute definition clause
1802
1803 when Attribute_Storage_Size => Storage_Size : declare
1804 Btype : constant Entity_Id := Base_Type (U_Ent);
1805 Sprag : Node_Id;
1806
1807 begin
1808 if Is_Task_Type (U_Ent) then
1809 Check_Restriction (No_Obsolescent_Features, N);
1810
1811 if Warn_On_Obsolescent_Feature then
1812 Error_Msg_N
1813 ("storage size clause for task is an " &
fbc67f84 1814 "obsolescent feature (RM J.9)?", N);
44e4341e 1815 Error_Msg_N
1816 ("\use Storage_Size pragma instead?", N);
1817 end if;
1818
1819 FOnly := True;
1820 end if;
1821
1822 if not Is_Access_Type (U_Ent)
1823 and then Ekind (U_Ent) /= E_Task_Type
1824 then
1825 Error_Msg_N ("storage size cannot be given for &", Nam);
1826
1827 elsif Is_Access_Type (U_Ent) and Is_Derived_Type (U_Ent) then
1828 Error_Msg_N
1829 ("storage size cannot be given for a derived access type",
1830 Nam);
1831
1832 elsif Has_Storage_Size_Clause (Btype) then
1833 Error_Msg_N ("storage size already given for &", Nam);
1834
1835 else
1836 Analyze_And_Resolve (Expr, Any_Integer);
1837
1838 if Is_Access_Type (U_Ent) then
1839 if Present (Associated_Storage_Pool (U_Ent)) then
1840 Error_Msg_N ("storage pool already given for &", Nam);
1841 return;
1842 end if;
1843
1844 if Compile_Time_Known_Value (Expr)
1845 and then Expr_Value (Expr) = 0
1846 then
1847 Set_No_Pool_Assigned (Btype);
1848 end if;
1849
1850 else -- Is_Task_Type (U_Ent)
1851 Sprag := Get_Rep_Pragma (Btype, Name_Storage_Size);
1852
1853 if Present (Sprag) then
1854 Error_Msg_Sloc := Sloc (Sprag);
1855 Error_Msg_N
1856 ("Storage_Size already specified#", Nam);
1857 return;
1858 end if;
1859 end if;
1860
1861 Set_Has_Storage_Size_Clause (Btype);
1862 end if;
1863 end Storage_Size;
1864
7189d17f 1865 -----------------
1866 -- Stream_Size --
1867 -----------------
1868
1869 when Attribute_Stream_Size => Stream_Size : declare
1870 Size : constant Uint := Static_Integer (Expr);
1871
1872 begin
15ebb600 1873 if Ada_Version <= Ada_95 then
1874 Check_Restriction (No_Implementation_Attributes, N);
1875 end if;
1876
7189d17f 1877 if Has_Stream_Size_Clause (U_Ent) then
1878 Error_Msg_N ("Stream_Size already given for &", Nam);
1879
1880 elsif Is_Elementary_Type (U_Ent) then
1881 if Size /= System_Storage_Unit
1882 and then
1883 Size /= System_Storage_Unit * 2
1884 and then
1885 Size /= System_Storage_Unit * 4
1886 and then
1887 Size /= System_Storage_Unit * 8
1888 then
1889 Error_Msg_Uint_1 := UI_From_Int (System_Storage_Unit);
1890 Error_Msg_N
1891 ("stream size for elementary type must be a"
1892 & " power of 2 and at least ^", N);
1893
1894 elsif RM_Size (U_Ent) > Size then
1895 Error_Msg_Uint_1 := RM_Size (U_Ent);
1896 Error_Msg_N
1897 ("stream size for elementary type must be a"
1898 & " power of 2 and at least ^", N);
1899 end if;
1900
1901 Set_Has_Stream_Size_Clause (U_Ent);
1902
1903 else
1904 Error_Msg_N ("Stream_Size cannot be given for &", Nam);
1905 end if;
1906 end Stream_Size;
1907
d6f39728 1908 ----------------
1909 -- Value_Size --
1910 ----------------
1911
1912 -- Value_Size attribute definition clause
1913
1914 when Attribute_Value_Size => Value_Size : declare
1915 Size : constant Uint := Static_Integer (Expr);
1916 Biased : Boolean;
1917
1918 begin
1919 if not Is_Type (U_Ent) then
1920 Error_Msg_N ("Value_Size cannot be given for &", Nam);
1921
1922 elsif Present
1923 (Get_Attribute_Definition_Clause
1924 (U_Ent, Attribute_Value_Size))
1925 then
1926 Error_Msg_N ("Value_Size already given for &", Nam);
1927
59ac57b5 1928 elsif Is_Array_Type (U_Ent)
1929 and then not Is_Constrained (U_Ent)
1930 then
1931 Error_Msg_N
1932 ("Value_Size cannot be given for unconstrained array", Nam);
1933
d6f39728 1934 else
1935 if Is_Elementary_Type (U_Ent) then
1936 Check_Size (Expr, U_Ent, Size, Biased);
1937 Set_Has_Biased_Representation (U_Ent, Biased);
cc46ff4b 1938
1939 if Biased and Warn_On_Biased_Representation then
1940 Error_Msg_N
1941 ("?value size clause forces biased representation", N);
1942 end if;
d6f39728 1943 end if;
1944
1945 Set_RM_Size (U_Ent, Size);
1946 end if;
1947 end Value_Size;
1948
1949 -----------
1950 -- Write --
1951 -----------
1952
9f373bb8 1953 when Attribute_Write =>
1954 Analyze_Stream_TSS_Definition (TSS_Stream_Write);
1955 Set_Has_Specified_Stream_Write (Ent);
d6f39728 1956
1957 -- All other attributes cannot be set
1958
1959 when others =>
1960 Error_Msg_N
1961 ("attribute& cannot be set with definition clause", N);
d6f39728 1962 end case;
1963
1964 -- The test for the type being frozen must be performed after
1965 -- any expression the clause has been analyzed since the expression
1966 -- itself might cause freezing that makes the clause illegal.
1967
1968 if Rep_Item_Too_Late (U_Ent, N, FOnly) then
1969 return;
1970 end if;
1971 end Analyze_Attribute_Definition_Clause;
1972
1973 ----------------------------
1974 -- Analyze_Code_Statement --
1975 ----------------------------
1976
1977 procedure Analyze_Code_Statement (N : Node_Id) is
1978 HSS : constant Node_Id := Parent (N);
1979 SBody : constant Node_Id := Parent (HSS);
1980 Subp : constant Entity_Id := Current_Scope;
1981 Stmt : Node_Id;
1982 Decl : Node_Id;
1983 StmtO : Node_Id;
1984 DeclO : Node_Id;
1985
1986 begin
1987 -- Analyze and check we get right type, note that this implements the
1988 -- requirement (RM 13.8(1)) that Machine_Code be with'ed, since that
1989 -- is the only way that Asm_Insn could possibly be visible.
1990
1991 Analyze_And_Resolve (Expression (N));
1992
1993 if Etype (Expression (N)) = Any_Type then
1994 return;
1995 elsif Etype (Expression (N)) /= RTE (RE_Asm_Insn) then
1996 Error_Msg_N ("incorrect type for code statement", N);
1997 return;
1998 end if;
1999
44e4341e 2000 Check_Code_Statement (N);
2001
d6f39728 2002 -- Make sure we appear in the handled statement sequence of a
2003 -- subprogram (RM 13.8(3)).
2004
2005 if Nkind (HSS) /= N_Handled_Sequence_Of_Statements
2006 or else Nkind (SBody) /= N_Subprogram_Body
2007 then
2008 Error_Msg_N
2009 ("code statement can only appear in body of subprogram", N);
2010 return;
2011 end if;
2012
2013 -- Do remaining checks (RM 13.8(3)) if not already done
2014
2015 if not Is_Machine_Code_Subprogram (Subp) then
2016 Set_Is_Machine_Code_Subprogram (Subp);
2017
2018 -- No exception handlers allowed
2019
2020 if Present (Exception_Handlers (HSS)) then
2021 Error_Msg_N
2022 ("exception handlers not permitted in machine code subprogram",
2023 First (Exception_Handlers (HSS)));
2024 end if;
2025
2026 -- No declarations other than use clauses and pragmas (we allow
2027 -- certain internally generated declarations as well).
2028
2029 Decl := First (Declarations (SBody));
2030 while Present (Decl) loop
2031 DeclO := Original_Node (Decl);
2032 if Comes_From_Source (DeclO)
fdd294d1 2033 and not Nkind_In (DeclO, N_Pragma,
2034 N_Use_Package_Clause,
2035 N_Use_Type_Clause,
2036 N_Implicit_Label_Declaration)
d6f39728 2037 then
2038 Error_Msg_N
2039 ("this declaration not allowed in machine code subprogram",
2040 DeclO);
2041 end if;
2042
2043 Next (Decl);
2044 end loop;
2045
2046 -- No statements other than code statements, pragmas, and labels.
2047 -- Again we allow certain internally generated statements.
2048
2049 Stmt := First (Statements (HSS));
2050 while Present (Stmt) loop
2051 StmtO := Original_Node (Stmt);
2052 if Comes_From_Source (StmtO)
fdd294d1 2053 and then not Nkind_In (StmtO, N_Pragma,
2054 N_Label,
2055 N_Code_Statement)
d6f39728 2056 then
2057 Error_Msg_N
2058 ("this statement is not allowed in machine code subprogram",
2059 StmtO);
2060 end if;
2061
2062 Next (Stmt);
2063 end loop;
2064 end if;
d6f39728 2065 end Analyze_Code_Statement;
2066
2067 -----------------------------------------------
2068 -- Analyze_Enumeration_Representation_Clause --
2069 -----------------------------------------------
2070
2071 procedure Analyze_Enumeration_Representation_Clause (N : Node_Id) is
2072 Ident : constant Node_Id := Identifier (N);
2073 Aggr : constant Node_Id := Array_Aggregate (N);
2074 Enumtype : Entity_Id;
2075 Elit : Entity_Id;
2076 Expr : Node_Id;
2077 Assoc : Node_Id;
2078 Choice : Node_Id;
2079 Val : Uint;
2080 Err : Boolean := False;
2081
2082 Lo : constant Uint := Expr_Value (Type_Low_Bound (Universal_Integer));
2083 Hi : constant Uint := Expr_Value (Type_High_Bound (Universal_Integer));
2084 Min : Uint;
2085 Max : Uint;
2086
2087 begin
fbc67f84 2088 if Ignore_Rep_Clauses then
2089 return;
2090 end if;
2091
d6f39728 2092 -- First some basic error checks
2093
2094 Find_Type (Ident);
2095 Enumtype := Entity (Ident);
2096
2097 if Enumtype = Any_Type
2098 or else Rep_Item_Too_Early (Enumtype, N)
2099 then
2100 return;
2101 else
2102 Enumtype := Underlying_Type (Enumtype);
2103 end if;
2104
2105 if not Is_Enumeration_Type (Enumtype) then
2106 Error_Msg_NE
2107 ("enumeration type required, found}",
2108 Ident, First_Subtype (Enumtype));
2109 return;
2110 end if;
2111
9dfe12ae 2112 -- Ignore rep clause on generic actual type. This will already have
2113 -- been flagged on the template as an error, and this is the safest
2114 -- way to ensure we don't get a junk cascaded message in the instance.
2115
2116 if Is_Generic_Actual_Type (Enumtype) then
2117 return;
2118
2119 -- Type must be in current scope
2120
2121 elsif Scope (Enumtype) /= Current_Scope then
d6f39728 2122 Error_Msg_N ("type must be declared in this scope", Ident);
2123 return;
2124
9dfe12ae 2125 -- Type must be a first subtype
2126
d6f39728 2127 elsif not Is_First_Subtype (Enumtype) then
2128 Error_Msg_N ("cannot give enumeration rep clause for subtype", N);
2129 return;
2130
9dfe12ae 2131 -- Ignore duplicate rep clause
2132
d6f39728 2133 elsif Has_Enumeration_Rep_Clause (Enumtype) then
2134 Error_Msg_N ("duplicate enumeration rep clause ignored", N);
2135 return;
2136
7189d17f 2137 -- Don't allow rep clause for standard [wide_[wide_]]character
9dfe12ae 2138
177675a7 2139 elsif Is_Standard_Character_Type (Enumtype) then
d6f39728 2140 Error_Msg_N ("enumeration rep clause not allowed for this type", N);
9dfe12ae 2141 return;
2142
d9125581 2143 -- Check that the expression is a proper aggregate (no parentheses)
2144
2145 elsif Paren_Count (Aggr) /= 0 then
2146 Error_Msg
2147 ("extra parentheses surrounding aggregate not allowed",
2148 First_Sloc (Aggr));
2149 return;
2150
9dfe12ae 2151 -- All tests passed, so set rep clause in place
d6f39728 2152
2153 else
2154 Set_Has_Enumeration_Rep_Clause (Enumtype);
2155 Set_Has_Enumeration_Rep_Clause (Base_Type (Enumtype));
2156 end if;
2157
2158 -- Now we process the aggregate. Note that we don't use the normal
2159 -- aggregate code for this purpose, because we don't want any of the
2160 -- normal expansion activities, and a number of special semantic
2161 -- rules apply (including the component type being any integer type)
2162
d6f39728 2163 Elit := First_Literal (Enumtype);
2164
2165 -- First the positional entries if any
2166
2167 if Present (Expressions (Aggr)) then
2168 Expr := First (Expressions (Aggr));
2169 while Present (Expr) loop
2170 if No (Elit) then
2171 Error_Msg_N ("too many entries in aggregate", Expr);
2172 return;
2173 end if;
2174
2175 Val := Static_Integer (Expr);
2176
d9125581 2177 -- Err signals that we found some incorrect entries processing
2178 -- the list. The final checks for completeness and ordering are
2179 -- skipped in this case.
2180
d6f39728 2181 if Val = No_Uint then
2182 Err := True;
d6f39728 2183 elsif Val < Lo or else Hi < Val then
2184 Error_Msg_N ("value outside permitted range", Expr);
2185 Err := True;
2186 end if;
2187
2188 Set_Enumeration_Rep (Elit, Val);
2189 Set_Enumeration_Rep_Expr (Elit, Expr);
2190 Next (Expr);
2191 Next (Elit);
2192 end loop;
2193 end if;
2194
2195 -- Now process the named entries if present
2196
2197 if Present (Component_Associations (Aggr)) then
2198 Assoc := First (Component_Associations (Aggr));
2199 while Present (Assoc) loop
2200 Choice := First (Choices (Assoc));
2201
2202 if Present (Next (Choice)) then
2203 Error_Msg_N
2204 ("multiple choice not allowed here", Next (Choice));
2205 Err := True;
2206 end if;
2207
2208 if Nkind (Choice) = N_Others_Choice then
2209 Error_Msg_N ("others choice not allowed here", Choice);
2210 Err := True;
2211
2212 elsif Nkind (Choice) = N_Range then
2213 -- ??? should allow zero/one element range here
2214 Error_Msg_N ("range not allowed here", Choice);
2215 Err := True;
2216
2217 else
2218 Analyze_And_Resolve (Choice, Enumtype);
2219
2220 if Is_Entity_Name (Choice)
2221 and then Is_Type (Entity (Choice))
2222 then
2223 Error_Msg_N ("subtype name not allowed here", Choice);
2224 Err := True;
2225 -- ??? should allow static subtype with zero/one entry
2226
2227 elsif Etype (Choice) = Base_Type (Enumtype) then
2228 if not Is_Static_Expression (Choice) then
9dfe12ae 2229 Flag_Non_Static_Expr
2230 ("non-static expression used for choice!", Choice);
d6f39728 2231 Err := True;
2232
2233 else
2234 Elit := Expr_Value_E (Choice);
2235
2236 if Present (Enumeration_Rep_Expr (Elit)) then
2237 Error_Msg_Sloc := Sloc (Enumeration_Rep_Expr (Elit));
2238 Error_Msg_NE
2239 ("representation for& previously given#",
2240 Choice, Elit);
2241 Err := True;
2242 end if;
2243
2244 Set_Enumeration_Rep_Expr (Elit, Choice);
2245
2246 Expr := Expression (Assoc);
2247 Val := Static_Integer (Expr);
2248
2249 if Val = No_Uint then
2250 Err := True;
2251
2252 elsif Val < Lo or else Hi < Val then
2253 Error_Msg_N ("value outside permitted range", Expr);
2254 Err := True;
2255 end if;
2256
2257 Set_Enumeration_Rep (Elit, Val);
2258 end if;
2259 end if;
2260 end if;
2261
2262 Next (Assoc);
2263 end loop;
2264 end if;
2265
2266 -- Aggregate is fully processed. Now we check that a full set of
2267 -- representations was given, and that they are in range and in order.
2268 -- These checks are only done if no other errors occurred.
2269
2270 if not Err then
2271 Min := No_Uint;
2272 Max := No_Uint;
2273
2274 Elit := First_Literal (Enumtype);
2275 while Present (Elit) loop
2276 if No (Enumeration_Rep_Expr (Elit)) then
2277 Error_Msg_NE ("missing representation for&!", N, Elit);
2278
2279 else
2280 Val := Enumeration_Rep (Elit);
2281
2282 if Min = No_Uint then
2283 Min := Val;
2284 end if;
2285
2286 if Val /= No_Uint then
2287 if Max /= No_Uint and then Val <= Max then
2288 Error_Msg_NE
2289 ("enumeration value for& not ordered!",
2290 Enumeration_Rep_Expr (Elit), Elit);
2291 end if;
2292
2293 Max := Val;
2294 end if;
2295
2296 -- If there is at least one literal whose representation
2297 -- is not equal to the Pos value, then note that this
2298 -- enumeration type has a non-standard representation.
2299
2300 if Val /= Enumeration_Pos (Elit) then
2301 Set_Has_Non_Standard_Rep (Base_Type (Enumtype));
2302 end if;
2303 end if;
2304
2305 Next (Elit);
2306 end loop;
2307
2308 -- Now set proper size information
2309
2310 declare
2311 Minsize : Uint := UI_From_Int (Minimum_Size (Enumtype));
2312
2313 begin
2314 if Has_Size_Clause (Enumtype) then
2315 if Esize (Enumtype) >= Minsize then
2316 null;
2317
2318 else
2319 Minsize :=
2320 UI_From_Int (Minimum_Size (Enumtype, Biased => True));
2321
2322 if Esize (Enumtype) < Minsize then
2323 Error_Msg_N ("previously given size is too small", N);
2324
2325 else
2326 Set_Has_Biased_Representation (Enumtype);
2327 end if;
2328 end if;
2329
2330 else
2331 Set_RM_Size (Enumtype, Minsize);
2332 Set_Enum_Esize (Enumtype);
2333 end if;
2334
2335 Set_RM_Size (Base_Type (Enumtype), RM_Size (Enumtype));
2336 Set_Esize (Base_Type (Enumtype), Esize (Enumtype));
2337 Set_Alignment (Base_Type (Enumtype), Alignment (Enumtype));
2338 end;
2339 end if;
2340
2341 -- We repeat the too late test in case it froze itself!
2342
2343 if Rep_Item_Too_Late (Enumtype, N) then
2344 null;
2345 end if;
d6f39728 2346 end Analyze_Enumeration_Representation_Clause;
2347
2348 ----------------------------
2349 -- Analyze_Free_Statement --
2350 ----------------------------
2351
2352 procedure Analyze_Free_Statement (N : Node_Id) is
2353 begin
2354 Analyze (Expression (N));
2355 end Analyze_Free_Statement;
2356
40ca69b9 2357 ---------------------------
2358 -- Analyze_Freeze_Entity --
2359 ---------------------------
2360
2361 procedure Analyze_Freeze_Entity (N : Node_Id) is
2362 E : constant Entity_Id := Entity (N);
2363
2364 begin
2365 -- For tagged types covering interfaces add internal entities that link
2366 -- the primitives of the interfaces with the primitives that cover them.
2367
2368 -- Note: These entities were originally generated only when generating
2369 -- code because their main purpose was to provide support to initialize
2370 -- the secondary dispatch tables. They are now generated also when
2371 -- compiling with no code generation to provide ASIS the relationship
2372 -- between interface primitives and tagged type primitives.
2373
2374 if Ada_Version >= Ada_05
2375 and then Ekind (E) = E_Record_Type
2376 and then Is_Tagged_Type (E)
2377 and then not Is_Interface (E)
2378 and then Has_Interfaces (E)
2379 then
2380 Add_Internal_Interface_Entities (E);
2381 end if;
2382 end Analyze_Freeze_Entity;
2383
d6f39728 2384 ------------------------------------------
2385 -- Analyze_Record_Representation_Clause --
2386 ------------------------------------------
2387
67278d60 2388 -- Note: we check as much as we can here, but we can't do any checks
2389 -- based on the position values (e.g. overlap checks) until freeze time
2390 -- because especially in Ada 2005 (machine scalar mode), the processing
2391 -- for non-standard bit order can substantially change the positions.
2392 -- See procedure Check_Record_Representation_Clause (called from Freeze)
2393 -- for the remainder of this processing.
2394
d6f39728 2395 procedure Analyze_Record_Representation_Clause (N : Node_Id) is
d6f39728 2396 Ident : constant Node_Id := Identifier (N);
2397 Rectype : Entity_Id;
d6f39728 2398 CC : Node_Id;
2399 Posit : Uint;
2400 Fbit : Uint;
2401 Lbit : Uint;
2402 Hbit : Uint := Uint_0;
2403 Comp : Entity_Id;
2404 Ocomp : Entity_Id;
2405 Biased : Boolean;
2406
639e37b0 2407 CR_Pragma : Node_Id := Empty;
2408 -- Points to N_Pragma node if Complete_Representation pragma present
2409
d6f39728 2410 begin
fbc67f84 2411 if Ignore_Rep_Clauses then
2412 return;
2413 end if;
2414
d6f39728 2415 Find_Type (Ident);
2416 Rectype := Entity (Ident);
2417
2418 if Rectype = Any_Type
2419 or else Rep_Item_Too_Early (Rectype, N)
2420 then
2421 return;
2422 else
2423 Rectype := Underlying_Type (Rectype);
2424 end if;
2425
2426 -- First some basic error checks
2427
2428 if not Is_Record_Type (Rectype) then
2429 Error_Msg_NE
2430 ("record type required, found}", Ident, First_Subtype (Rectype));
2431 return;
2432
2433 elsif Is_Unchecked_Union (Rectype) then
2434 Error_Msg_N
2435 ("record rep clause not allowed for Unchecked_Union", N);
2436
2437 elsif Scope (Rectype) /= Current_Scope then
2438 Error_Msg_N ("type must be declared in this scope", N);
2439 return;
2440
2441 elsif not Is_First_Subtype (Rectype) then
2442 Error_Msg_N ("cannot give record rep clause for subtype", N);
2443 return;
2444
2445 elsif Has_Record_Rep_Clause (Rectype) then
2446 Error_Msg_N ("duplicate record rep clause ignored", N);
2447 return;
2448
2449 elsif Rep_Item_Too_Late (Rectype, N) then
2450 return;
2451 end if;
2452
2453 if Present (Mod_Clause (N)) then
2454 declare
2455 Loc : constant Source_Ptr := Sloc (N);
2456 M : constant Node_Id := Mod_Clause (N);
2457 P : constant List_Id := Pragmas_Before (M);
d6f39728 2458 AtM_Nod : Node_Id;
2459
9dfe12ae 2460 Mod_Val : Uint;
2461 pragma Warnings (Off, Mod_Val);
2462
d6f39728 2463 begin
e0521a36 2464 Check_Restriction (No_Obsolescent_Features, Mod_Clause (N));
2465
9dfe12ae 2466 if Warn_On_Obsolescent_Feature then
2467 Error_Msg_N
fbc67f84 2468 ("mod clause is an obsolescent feature (RM J.8)?", N);
9dfe12ae 2469 Error_Msg_N
d53a018a 2470 ("\use alignment attribute definition clause instead?", N);
9dfe12ae 2471 end if;
2472
d6f39728 2473 if Present (P) then
2474 Analyze_List (P);
2475 end if;
2476
fbc67f84 2477 -- In ASIS_Mode mode, expansion is disabled, but we must convert
2478 -- the Mod clause into an alignment clause anyway, so that the
2479 -- back-end can compute and back-annotate properly the size and
2480 -- alignment of types that may include this record.
d6f39728 2481
15ebb600 2482 -- This seems dubious, this destroys the source tree in a manner
2483 -- not detectable by ASIS ???
2484
d6f39728 2485 if Operating_Mode = Check_Semantics
9dfe12ae 2486 and then ASIS_Mode
d6f39728 2487 then
2488 AtM_Nod :=
2489 Make_Attribute_Definition_Clause (Loc,
2490 Name => New_Reference_To (Base_Type (Rectype), Loc),
2491 Chars => Name_Alignment,
2492 Expression => Relocate_Node (Expression (M)));
2493
2494 Set_From_At_Mod (AtM_Nod);
2495 Insert_After (N, AtM_Nod);
2496 Mod_Val := Get_Alignment_Value (Expression (AtM_Nod));
2497 Set_Mod_Clause (N, Empty);
2498
2499 else
2500 -- Get the alignment value to perform error checking
2501
2502 Mod_Val := Get_Alignment_Value (Expression (M));
d6f39728 2503 end if;
2504 end;
2505 end if;
2506
3062c401 2507 -- For untagged types, clear any existing component clauses for the
2508 -- type. If the type is derived, this is what allows us to override
2509 -- a rep clause for the parent. For type extensions, the representation
2510 -- of the inherited components is inherited, so we want to keep previous
2511 -- component clauses for completeness.
d6f39728 2512
3062c401 2513 if not Is_Tagged_Type (Rectype) then
2514 Comp := First_Component_Or_Discriminant (Rectype);
2515 while Present (Comp) loop
2516 Set_Component_Clause (Comp, Empty);
2517 Next_Component_Or_Discriminant (Comp);
2518 end loop;
2519 end if;
d6f39728 2520
2521 -- All done if no component clauses
2522
2523 CC := First (Component_Clauses (N));
2524
2525 if No (CC) then
2526 return;
2527 end if;
2528
f15731c4 2529 -- A representation like this applies to the base type
d6f39728 2530
2531 Set_Has_Record_Rep_Clause (Base_Type (Rectype));
2532 Set_Has_Non_Standard_Rep (Base_Type (Rectype));
2533 Set_Has_Specified_Layout (Base_Type (Rectype));
2534
d6f39728 2535 -- Process the component clauses
2536
2537 while Present (CC) loop
2538
639e37b0 2539 -- Pragma
d6f39728 2540
2541 if Nkind (CC) = N_Pragma then
2542 Analyze (CC);
2543
639e37b0 2544 -- The only pragma of interest is Complete_Representation
2545
fdd294d1 2546 if Pragma_Name (CC) = Name_Complete_Representation then
639e37b0 2547 CR_Pragma := CC;
2548 end if;
2549
d6f39728 2550 -- Processing for real component clause
2551
2552 else
d6f39728 2553 Posit := Static_Integer (Position (CC));
2554 Fbit := Static_Integer (First_Bit (CC));
2555 Lbit := Static_Integer (Last_Bit (CC));
2556
2557 if Posit /= No_Uint
2558 and then Fbit /= No_Uint
2559 and then Lbit /= No_Uint
2560 then
2561 if Posit < 0 then
2562 Error_Msg_N
2563 ("position cannot be negative", Position (CC));
2564
2565 elsif Fbit < 0 then
2566 Error_Msg_N
2567 ("first bit cannot be negative", First_Bit (CC));
2568
177675a7 2569 -- The Last_Bit specified in a component clause must not be
2570 -- less than the First_Bit minus one (RM-13.5.1(10)).
2571
2572 elsif Lbit < Fbit - 1 then
2573 Error_Msg_N
2574 ("last bit cannot be less than first bit minus one",
2575 Last_Bit (CC));
2576
d6f39728 2577 -- Values look OK, so find the corresponding record component
2578 -- Even though the syntax allows an attribute reference for
2579 -- implementation-defined components, GNAT does not allow the
2580 -- tag to get an explicit position.
2581
2582 elsif Nkind (Component_Name (CC)) = N_Attribute_Reference then
d6f39728 2583 if Attribute_Name (Component_Name (CC)) = Name_Tag then
2584 Error_Msg_N ("position of tag cannot be specified", CC);
2585 else
2586 Error_Msg_N ("illegal component name", CC);
2587 end if;
2588
2589 else
2590 Comp := First_Entity (Rectype);
2591 while Present (Comp) loop
2592 exit when Chars (Comp) = Chars (Component_Name (CC));
2593 Next_Entity (Comp);
2594 end loop;
2595
2596 if No (Comp) then
2597
2598 -- Maybe component of base type that is absent from
2599 -- statically constrained first subtype.
2600
2601 Comp := First_Entity (Base_Type (Rectype));
2602 while Present (Comp) loop
2603 exit when Chars (Comp) = Chars (Component_Name (CC));
2604 Next_Entity (Comp);
2605 end loop;
2606 end if;
2607
2608 if No (Comp) then
2609 Error_Msg_N
2610 ("component clause is for non-existent field", CC);
2611
2612 elsif Present (Component_Clause (Comp)) then
3062c401 2613
1a34e48c 2614 -- Diagnose duplicate rep clause, or check consistency
fdd294d1 2615 -- if this is an inherited component. In a double fault,
3062c401 2616 -- there may be a duplicate inconsistent clause for an
2617 -- inherited component.
2618
fdd294d1 2619 if Scope (Original_Record_Component (Comp)) = Rectype
2620 or else Parent (Component_Clause (Comp)) = N
3062c401 2621 then
2622 Error_Msg_Sloc := Sloc (Component_Clause (Comp));
2623 Error_Msg_N ("component clause previously given#", CC);
2624
2625 else
2626 declare
2627 Rep1 : constant Node_Id := Component_Clause (Comp);
3062c401 2628 begin
2629 if Intval (Position (Rep1)) /=
2630 Intval (Position (CC))
2631 or else Intval (First_Bit (Rep1)) /=
2632 Intval (First_Bit (CC))
2633 or else Intval (Last_Bit (Rep1)) /=
2634 Intval (Last_Bit (CC))
2635 then
2636 Error_Msg_N ("component clause inconsistent "
2637 & "with representation of ancestor", CC);
3062c401 2638 elsif Warn_On_Redundant_Constructs then
2639 Error_Msg_N ("?redundant component clause "
2640 & "for inherited component!", CC);
2641 end if;
2642 end;
2643 end if;
d6f39728 2644
d2b860b4 2645 -- Normal case where this is the first component clause we
2646 -- have seen for this entity, so set it up properly.
2647
d6f39728 2648 else
83f8f0a6 2649 -- Make reference for field in record rep clause and set
2650 -- appropriate entity field in the field identifier.
2651
2652 Generate_Reference
2653 (Comp, Component_Name (CC), Set_Ref => False);
2654 Set_Entity (Component_Name (CC), Comp);
2655
2866d595 2656 -- Update Fbit and Lbit to the actual bit number
d6f39728 2657
2658 Fbit := Fbit + UI_From_Int (SSU) * Posit;
2659 Lbit := Lbit + UI_From_Int (SSU) * Posit;
2660
d6f39728 2661 if Has_Size_Clause (Rectype)
2662 and then Esize (Rectype) <= Lbit
2663 then
2664 Error_Msg_N
2665 ("bit number out of range of specified size",
2666 Last_Bit (CC));
2667 else
2668 Set_Component_Clause (Comp, CC);
2669 Set_Component_Bit_Offset (Comp, Fbit);
2670 Set_Esize (Comp, 1 + (Lbit - Fbit));
2671 Set_Normalized_First_Bit (Comp, Fbit mod SSU);
2672 Set_Normalized_Position (Comp, Fbit / SSU);
2673
ea61a7ea 2674 -- This information is also set in the corresponding
2675 -- component of the base type, found by accessing the
2676 -- Original_Record_Component link if it is present.
d6f39728 2677
2678 Ocomp := Original_Record_Component (Comp);
2679
2680 if Hbit < Lbit then
2681 Hbit := Lbit;
2682 end if;
2683
2684 Check_Size
2685 (Component_Name (CC),
2686 Etype (Comp),
2687 Esize (Comp),
2688 Biased);
2689
2690 Set_Has_Biased_Representation (Comp, Biased);
2691
cc46ff4b 2692 if Biased and Warn_On_Biased_Representation then
2693 Error_Msg_F
2694 ("?component clause forces biased "
2695 & "representation", CC);
2696 end if;
2697
d6f39728 2698 if Present (Ocomp) then
2699 Set_Component_Clause (Ocomp, CC);
2700 Set_Component_Bit_Offset (Ocomp, Fbit);
2701 Set_Normalized_First_Bit (Ocomp, Fbit mod SSU);
2702 Set_Normalized_Position (Ocomp, Fbit / SSU);
2703 Set_Esize (Ocomp, 1 + (Lbit - Fbit));
2704
2705 Set_Normalized_Position_Max
2706 (Ocomp, Normalized_Position (Ocomp));
2707
2708 Set_Has_Biased_Representation
2709 (Ocomp, Has_Biased_Representation (Comp));
2710 end if;
2711
2712 if Esize (Comp) < 0 then
2713 Error_Msg_N ("component size is negative", CC);
2714 end if;
2715 end if;
2716 end if;
2717 end if;
2718 end if;
2719 end if;
2720
2721 Next (CC);
2722 end loop;
2723
67278d60 2724 -- Check missing components if Complete_Representation pragma appeared
d6f39728 2725
67278d60 2726 if Present (CR_Pragma) then
2727 Comp := First_Component_Or_Discriminant (Rectype);
2728 while Present (Comp) loop
2729 if No (Component_Clause (Comp)) then
2730 Error_Msg_NE
2731 ("missing component clause for &", CR_Pragma, Comp);
2732 end if;
d6f39728 2733
67278d60 2734 Next_Component_Or_Discriminant (Comp);
2735 end loop;
d6f39728 2736
67278d60 2737 -- If no Complete_Representation pragma, warn if missing components
15ebb600 2738
fdd294d1 2739 elsif Warn_On_Unrepped_Components then
15ebb600 2740 declare
2741 Num_Repped_Components : Nat := 0;
2742 Num_Unrepped_Components : Nat := 0;
2743
2744 begin
2745 -- First count number of repped and unrepped components
2746
2747 Comp := First_Component_Or_Discriminant (Rectype);
2748 while Present (Comp) loop
2749 if Present (Component_Clause (Comp)) then
2750 Num_Repped_Components := Num_Repped_Components + 1;
2751 else
2752 Num_Unrepped_Components := Num_Unrepped_Components + 1;
2753 end if;
2754
2755 Next_Component_Or_Discriminant (Comp);
2756 end loop;
2757
2758 -- We are only interested in the case where there is at least one
2759 -- unrepped component, and at least half the components have rep
2760 -- clauses. We figure that if less than half have them, then the
87f9eef5 2761 -- partial rep clause is really intentional. If the component
2762 -- type has no underlying type set at this point (as for a generic
2763 -- formal type), we don't know enough to give a warning on the
2764 -- component.
15ebb600 2765
2766 if Num_Unrepped_Components > 0
2767 and then Num_Unrepped_Components < Num_Repped_Components
2768 then
2769 Comp := First_Component_Or_Discriminant (Rectype);
2770 while Present (Comp) loop
83f8f0a6 2771 if No (Component_Clause (Comp))
3062c401 2772 and then Comes_From_Source (Comp)
87f9eef5 2773 and then Present (Underlying_Type (Etype (Comp)))
83f8f0a6 2774 and then (Is_Scalar_Type (Underlying_Type (Etype (Comp)))
67278d60 2775 or else Size_Known_At_Compile_Time
2776 (Underlying_Type (Etype (Comp))))
fdd294d1 2777 and then not Has_Warnings_Off (Rectype)
83f8f0a6 2778 then
15ebb600 2779 Error_Msg_Sloc := Sloc (Comp);
2780 Error_Msg_NE
2781 ("?no component clause given for & declared #",
2782 N, Comp);
2783 end if;
2784
2785 Next_Component_Or_Discriminant (Comp);
2786 end loop;
2787 end if;
2788 end;
d6f39728 2789 end if;
d6f39728 2790 end Analyze_Record_Representation_Clause;
2791
d6f39728 2792 -----------------------------------
2793 -- Check_Constant_Address_Clause --
2794 -----------------------------------
2795
2796 procedure Check_Constant_Address_Clause
2797 (Expr : Node_Id;
2798 U_Ent : Entity_Id)
2799 is
2800 procedure Check_At_Constant_Address (Nod : Node_Id);
fdd294d1 2801 -- Checks that the given node N represents a name whose 'Address is
2802 -- constant (in the same sense as OK_Constant_Address_Clause, i.e. the
2803 -- address value is the same at the point of declaration of U_Ent and at
2804 -- the time of elaboration of the address clause.
d6f39728 2805
2806 procedure Check_Expr_Constants (Nod : Node_Id);
fdd294d1 2807 -- Checks that Nod meets the requirements for a constant address clause
2808 -- in the sense of the enclosing procedure.
d6f39728 2809
2810 procedure Check_List_Constants (Lst : List_Id);
2811 -- Check that all elements of list Lst meet the requirements for a
2812 -- constant address clause in the sense of the enclosing procedure.
2813
2814 -------------------------------
2815 -- Check_At_Constant_Address --
2816 -------------------------------
2817
2818 procedure Check_At_Constant_Address (Nod : Node_Id) is
2819 begin
2820 if Is_Entity_Name (Nod) then
2821 if Present (Address_Clause (Entity ((Nod)))) then
2822 Error_Msg_NE
2823 ("invalid address clause for initialized object &!",
2824 Nod, U_Ent);
2825 Error_Msg_NE
2826 ("address for& cannot" &
fbc67f84 2827 " depend on another address clause! (RM 13.1(22))!",
d6f39728 2828 Nod, U_Ent);
2829
2830 elsif In_Same_Source_Unit (Entity (Nod), U_Ent)
2831 and then Sloc (U_Ent) < Sloc (Entity (Nod))
2832 then
2833 Error_Msg_NE
2834 ("invalid address clause for initialized object &!",
2835 Nod, U_Ent);
2f582d72 2836 Error_Msg_Node_2 := U_Ent;
2837 Error_Msg_NE
2838 ("\& must be defined before & (RM 13.1(22))!",
2839 Nod, Entity (Nod));
d6f39728 2840 end if;
2841
2842 elsif Nkind (Nod) = N_Selected_Component then
2843 declare
2844 T : constant Entity_Id := Etype (Prefix (Nod));
2845
2846 begin
2847 if (Is_Record_Type (T)
2848 and then Has_Discriminants (T))
2849 or else
2850 (Is_Access_Type (T)
2851 and then Is_Record_Type (Designated_Type (T))
2852 and then Has_Discriminants (Designated_Type (T)))
2853 then
2854 Error_Msg_NE
2855 ("invalid address clause for initialized object &!",
2856 Nod, U_Ent);
2857 Error_Msg_N
2858 ("\address cannot depend on component" &
fbc67f84 2859 " of discriminated record (RM 13.1(22))!",
d6f39728 2860 Nod);
2861 else
2862 Check_At_Constant_Address (Prefix (Nod));
2863 end if;
2864 end;
2865
2866 elsif Nkind (Nod) = N_Indexed_Component then
2867 Check_At_Constant_Address (Prefix (Nod));
2868 Check_List_Constants (Expressions (Nod));
2869
2870 else
2871 Check_Expr_Constants (Nod);
2872 end if;
2873 end Check_At_Constant_Address;
2874
2875 --------------------------
2876 -- Check_Expr_Constants --
2877 --------------------------
2878
2879 procedure Check_Expr_Constants (Nod : Node_Id) is
e7b2d6bc 2880 Loc_U_Ent : constant Source_Ptr := Sloc (U_Ent);
2881 Ent : Entity_Id := Empty;
2882
d6f39728 2883 begin
2884 if Nkind (Nod) in N_Has_Etype
2885 and then Etype (Nod) = Any_Type
2886 then
2887 return;
2888 end if;
2889
2890 case Nkind (Nod) is
2891 when N_Empty | N_Error =>
2892 return;
2893
2894 when N_Identifier | N_Expanded_Name =>
e7b2d6bc 2895 Ent := Entity (Nod);
9dfe12ae 2896
2897 -- We need to look at the original node if it is different
2898 -- from the node, since we may have rewritten things and
2899 -- substituted an identifier representing the rewrite.
2900
2901 if Original_Node (Nod) /= Nod then
2902 Check_Expr_Constants (Original_Node (Nod));
2903
2904 -- If the node is an object declaration without initial
2905 -- value, some code has been expanded, and the expression
2906 -- is not constant, even if the constituents might be
fdd294d1 2907 -- acceptable, as in A'Address + offset.
9dfe12ae 2908
e7b2d6bc 2909 if Ekind (Ent) = E_Variable
fdd294d1 2910 and then
2911 Nkind (Declaration_Node (Ent)) = N_Object_Declaration
9dfe12ae 2912 and then
e7b2d6bc 2913 No (Expression (Declaration_Node (Ent)))
2914 then
2915 Error_Msg_NE
2916 ("invalid address clause for initialized object &!",
2917 Nod, U_Ent);
2918
2919 -- If entity is constant, it may be the result of expanding
2920 -- a check. We must verify that its declaration appears
2921 -- before the object in question, else we also reject the
2922 -- address clause.
2923
2924 elsif Ekind (Ent) = E_Constant
2925 and then In_Same_Source_Unit (Ent, U_Ent)
2926 and then Sloc (Ent) > Loc_U_Ent
9dfe12ae 2927 then
2928 Error_Msg_NE
2929 ("invalid address clause for initialized object &!",
2930 Nod, U_Ent);
2931 end if;
e7b2d6bc 2932
9dfe12ae 2933 return;
2934 end if;
2935
2866d595 2936 -- Otherwise look at the identifier and see if it is OK
9dfe12ae 2937
d3ef794c 2938 if Ekind_In (Ent, E_Named_Integer, E_Named_Real)
2939 or else Is_Type (Ent)
e7b2d6bc 2940 then
2941 return;
d6f39728 2942
e7b2d6bc 2943 elsif
2944 Ekind (Ent) = E_Constant
2945 or else
2946 Ekind (Ent) = E_In_Parameter
2947 then
fdd294d1 2948 -- This is the case where we must have Ent defined before
2949 -- U_Ent. Clearly if they are in different units this
2950 -- requirement is met since the unit containing Ent is
2951 -- already processed.
d6f39728 2952
e7b2d6bc 2953 if not In_Same_Source_Unit (Ent, U_Ent) then
2954 return;
d6f39728 2955
fdd294d1 2956 -- Otherwise location of Ent must be before the location
2957 -- of U_Ent, that's what prior defined means.
d6f39728 2958
e7b2d6bc 2959 elsif Sloc (Ent) < Loc_U_Ent then
2960 return;
d6f39728 2961
2962 else
2963 Error_Msg_NE
2964 ("invalid address clause for initialized object &!",
2965 Nod, U_Ent);
2f582d72 2966 Error_Msg_Node_2 := U_Ent;
2967 Error_Msg_NE
2968 ("\& must be defined before & (RM 13.1(22))!",
2969 Nod, Ent);
e7b2d6bc 2970 end if;
9dfe12ae 2971
e7b2d6bc 2972 elsif Nkind (Original_Node (Nod)) = N_Function_Call then
2973 Check_Expr_Constants (Original_Node (Nod));
2974
2975 else
2976 Error_Msg_NE
2977 ("invalid address clause for initialized object &!",
2978 Nod, U_Ent);
2979
2980 if Comes_From_Source (Ent) then
2f582d72 2981 Error_Msg_NE
2982 ("\reference to variable& not allowed"
2983 & " (RM 13.1(22))!", Nod, Ent);
e7b2d6bc 2984 else
2985 Error_Msg_N
2986 ("non-static expression not allowed"
fbc67f84 2987 & " (RM 13.1(22))!", Nod);
d6f39728 2988 end if;
e7b2d6bc 2989 end if;
d6f39728 2990
93735cb8 2991 when N_Integer_Literal =>
2992
2993 -- If this is a rewritten unchecked conversion, in a system
2994 -- where Address is an integer type, always use the base type
2995 -- for a literal value. This is user-friendly and prevents
2996 -- order-of-elaboration issues with instances of unchecked
2997 -- conversion.
2998
2999 if Nkind (Original_Node (Nod)) = N_Function_Call then
3000 Set_Etype (Nod, Base_Type (Etype (Nod)));
3001 end if;
3002
3003 when N_Real_Literal |
d6f39728 3004 N_String_Literal |
3005 N_Character_Literal =>
3006 return;
3007
3008 when N_Range =>
3009 Check_Expr_Constants (Low_Bound (Nod));
3010 Check_Expr_Constants (High_Bound (Nod));
3011
3012 when N_Explicit_Dereference =>
3013 Check_Expr_Constants (Prefix (Nod));
3014
3015 when N_Indexed_Component =>
3016 Check_Expr_Constants (Prefix (Nod));
3017 Check_List_Constants (Expressions (Nod));
3018
3019 when N_Slice =>
3020 Check_Expr_Constants (Prefix (Nod));
3021 Check_Expr_Constants (Discrete_Range (Nod));
3022
3023 when N_Selected_Component =>
3024 Check_Expr_Constants (Prefix (Nod));
3025
3026 when N_Attribute_Reference =>
9dfe12ae 3027 if Attribute_Name (Nod) = Name_Address
3028 or else
3029 Attribute_Name (Nod) = Name_Access
d6f39728 3030 or else
9dfe12ae 3031 Attribute_Name (Nod) = Name_Unchecked_Access
d6f39728 3032 or else
9dfe12ae 3033 Attribute_Name (Nod) = Name_Unrestricted_Access
d6f39728 3034 then
3035 Check_At_Constant_Address (Prefix (Nod));
3036
3037 else
3038 Check_Expr_Constants (Prefix (Nod));
3039 Check_List_Constants (Expressions (Nod));
3040 end if;
3041
3042 when N_Aggregate =>
3043 Check_List_Constants (Component_Associations (Nod));
3044 Check_List_Constants (Expressions (Nod));
3045
3046 when N_Component_Association =>
3047 Check_Expr_Constants (Expression (Nod));
3048
3049 when N_Extension_Aggregate =>
3050 Check_Expr_Constants (Ancestor_Part (Nod));
3051 Check_List_Constants (Component_Associations (Nod));
3052 Check_List_Constants (Expressions (Nod));
3053
3054 when N_Null =>
3055 return;
3056
e7771556 3057 when N_Binary_Op | N_Short_Circuit | N_Membership_Test =>
d6f39728 3058 Check_Expr_Constants (Left_Opnd (Nod));
3059 Check_Expr_Constants (Right_Opnd (Nod));
3060
3061 when N_Unary_Op =>
3062 Check_Expr_Constants (Right_Opnd (Nod));
3063
3064 when N_Type_Conversion |
3065 N_Qualified_Expression |
3066 N_Allocator =>
3067 Check_Expr_Constants (Expression (Nod));
3068
3069 when N_Unchecked_Type_Conversion =>
3070 Check_Expr_Constants (Expression (Nod));
3071
fdd294d1 3072 -- If this is a rewritten unchecked conversion, subtypes in
3073 -- this node are those created within the instance. To avoid
3074 -- order of elaboration issues, replace them with their base
3075 -- types. Note that address clauses can cause order of
3076 -- elaboration problems because they are elaborated by the
3077 -- back-end at the point of definition, and may mention
3078 -- entities declared in between (as long as everything is
3079 -- static). It is user-friendly to allow unchecked conversions
3080 -- in this context.
d6f39728 3081
3082 if Nkind (Original_Node (Nod)) = N_Function_Call then
3083 Set_Etype (Expression (Nod),
3084 Base_Type (Etype (Expression (Nod))));
3085 Set_Etype (Nod, Base_Type (Etype (Nod)));
3086 end if;
3087
3088 when N_Function_Call =>
3089 if not Is_Pure (Entity (Name (Nod))) then
3090 Error_Msg_NE
3091 ("invalid address clause for initialized object &!",
3092 Nod, U_Ent);
3093
3094 Error_Msg_NE
fbc67f84 3095 ("\function & is not pure (RM 13.1(22))!",
d6f39728 3096 Nod, Entity (Name (Nod)));
3097
3098 else
3099 Check_List_Constants (Parameter_Associations (Nod));
3100 end if;
3101
3102 when N_Parameter_Association =>
3103 Check_Expr_Constants (Explicit_Actual_Parameter (Nod));
3104
3105 when others =>
3106 Error_Msg_NE
3107 ("invalid address clause for initialized object &!",
3108 Nod, U_Ent);
3109 Error_Msg_NE
fbc67f84 3110 ("\must be constant defined before& (RM 13.1(22))!",
d6f39728 3111 Nod, U_Ent);
3112 end case;
3113 end Check_Expr_Constants;
3114
3115 --------------------------
3116 -- Check_List_Constants --
3117 --------------------------
3118
3119 procedure Check_List_Constants (Lst : List_Id) is
3120 Nod1 : Node_Id;
3121
3122 begin
3123 if Present (Lst) then
3124 Nod1 := First (Lst);
3125 while Present (Nod1) loop
3126 Check_Expr_Constants (Nod1);
3127 Next (Nod1);
3128 end loop;
3129 end if;
3130 end Check_List_Constants;
3131
3132 -- Start of processing for Check_Constant_Address_Clause
3133
3134 begin
3135 Check_Expr_Constants (Expr);
3136 end Check_Constant_Address_Clause;
3137
67278d60 3138 ----------------------------------------
3139 -- Check_Record_Representation_Clause --
3140 ----------------------------------------
3141
3142 procedure Check_Record_Representation_Clause (N : Node_Id) is
3143 Loc : constant Source_Ptr := Sloc (N);
3144 Ident : constant Node_Id := Identifier (N);
3145 Rectype : Entity_Id;
3146 Fent : Entity_Id;
3147 CC : Node_Id;
3148 Fbit : Uint;
3149 Lbit : Uint;
3150 Hbit : Uint := Uint_0;
3151 Comp : Entity_Id;
3152 Pcomp : Entity_Id;
3153
3154 Max_Bit_So_Far : Uint;
3155 -- Records the maximum bit position so far. If all field positions
3156 -- are monotonically increasing, then we can skip the circuit for
3157 -- checking for overlap, since no overlap is possible.
3158
3159 Tagged_Parent : Entity_Id := Empty;
3160 -- This is set in the case of a derived tagged type for which we have
3161 -- Is_Fully_Repped_Tagged_Type True (indicating that all components are
3162 -- positioned by record representation clauses). In this case we must
3163 -- check for overlap between components of this tagged type, and the
3164 -- components of its parent. Tagged_Parent will point to this parent
3165 -- type. For all other cases Tagged_Parent is left set to Empty.
3166
3167 Parent_Last_Bit : Uint;
3168 -- Relevant only if Tagged_Parent is set, Parent_Last_Bit indicates the
3169 -- last bit position for any field in the parent type. We only need to
3170 -- check overlap for fields starting below this point.
3171
3172 Overlap_Check_Required : Boolean;
3173 -- Used to keep track of whether or not an overlap check is required
3174
3175 Ccount : Natural := 0;
3176 -- Number of component clauses in record rep clause
3177
3178 procedure Check_Component_Overlap (C1_Ent, C2_Ent : Entity_Id);
3179 -- Given two entities for record components or discriminants, checks
3180 -- if they have overlapping component clauses and issues errors if so.
3181
3182 procedure Find_Component;
3183 -- Finds component entity corresponding to current component clause (in
3184 -- CC), and sets Comp to the entity, and Fbit/Lbit to the zero origin
3185 -- start/stop bits for the field. If there is no matching component or
3186 -- if the matching component does not have a component clause, then
3187 -- that's an error and Comp is set to Empty, but no error message is
3188 -- issued, since the message was already given. Comp is also set to
3189 -- Empty if the current "component clause" is in fact a pragma.
3190
3191 -----------------------------
3192 -- Check_Component_Overlap --
3193 -----------------------------
3194
3195 procedure Check_Component_Overlap (C1_Ent, C2_Ent : Entity_Id) is
3196 CC1 : constant Node_Id := Component_Clause (C1_Ent);
3197 CC2 : constant Node_Id := Component_Clause (C2_Ent);
3198 begin
3199 if Present (CC1) and then Present (CC2) then
3200
3201 -- Exclude odd case where we have two tag fields in the same
3202 -- record, both at location zero. This seems a bit strange, but
3203 -- it seems to happen in some circumstances, perhaps on an error.
3204
3205 if Chars (C1_Ent) = Name_uTag
3206 and then
3207 Chars (C2_Ent) = Name_uTag
3208 then
3209 return;
3210 end if;
3211
3212 -- Here we check if the two fields overlap
3213
3214 declare
3215 S1 : constant Uint := Component_Bit_Offset (C1_Ent);
3216 S2 : constant Uint := Component_Bit_Offset (C2_Ent);
3217 E1 : constant Uint := S1 + Esize (C1_Ent);
3218 E2 : constant Uint := S2 + Esize (C2_Ent);
3219
3220 begin
3221 if E2 <= S1 or else E1 <= S2 then
3222 null;
3223 else
3224 Error_Msg_Node_2 := Component_Name (CC2);
3225 Error_Msg_Sloc := Sloc (Error_Msg_Node_2);
3226 Error_Msg_Node_1 := Component_Name (CC1);
3227 Error_Msg_N
3228 ("component& overlaps & #", Component_Name (CC1));
3229 end if;
3230 end;
3231 end if;
3232 end Check_Component_Overlap;
3233
3234 --------------------
3235 -- Find_Component --
3236 --------------------
3237
3238 procedure Find_Component is
3239
3240 procedure Search_Component (R : Entity_Id);
3241 -- Search components of R for a match. If found, Comp is set.
3242
3243 ----------------------
3244 -- Search_Component --
3245 ----------------------
3246
3247 procedure Search_Component (R : Entity_Id) is
3248 begin
3249 Comp := First_Component_Or_Discriminant (R);
3250 while Present (Comp) loop
3251
3252 -- Ignore error of attribute name for component name (we
3253 -- already gave an error message for this, so no need to
3254 -- complain here)
3255
3256 if Nkind (Component_Name (CC)) = N_Attribute_Reference then
3257 null;
3258 else
3259 exit when Chars (Comp) = Chars (Component_Name (CC));
3260 end if;
3261
3262 Next_Component_Or_Discriminant (Comp);
3263 end loop;
3264 end Search_Component;
3265
3266 -- Start of processing for Find_Component
3267
3268 begin
3269 -- Return with Comp set to Empty if we have a pragma
3270
3271 if Nkind (CC) = N_Pragma then
3272 Comp := Empty;
3273 return;
3274 end if;
3275
3276 -- Search current record for matching component
3277
3278 Search_Component (Rectype);
3279
3280 -- If not found, maybe component of base type that is absent from
3281 -- statically constrained first subtype.
3282
3283 if No (Comp) then
3284 Search_Component (Base_Type (Rectype));
3285 end if;
3286
3287 -- If no component, or the component does not reference the component
3288 -- clause in question, then there was some previous error for which
3289 -- we already gave a message, so just return with Comp Empty.
3290
3291 if No (Comp)
3292 or else Component_Clause (Comp) /= CC
3293 then
3294 Comp := Empty;
3295
3296 -- Normal case where we have a component clause
3297
3298 else
3299 Fbit := Component_Bit_Offset (Comp);
3300 Lbit := Fbit + Esize (Comp) - 1;
3301 end if;
3302 end Find_Component;
3303
3304 -- Start of processing for Check_Record_Representation_Clause
3305
3306 begin
3307 Find_Type (Ident);
3308 Rectype := Entity (Ident);
3309
3310 if Rectype = Any_Type then
3311 return;
3312 else
3313 Rectype := Underlying_Type (Rectype);
3314 end if;
3315
3316 -- See if we have a fully repped derived tagged type
3317
3318 declare
3319 PS : constant Entity_Id := Parent_Subtype (Rectype);
3320
3321 begin
3322 if Present (PS) and then Is_Fully_Repped_Tagged_Type (PS) then
3323 Tagged_Parent := PS;
3324
3325 -- Find maximum bit of any component of the parent type
3326
3327 Parent_Last_Bit := UI_From_Int (System_Address_Size - 1);
3328 Pcomp := First_Entity (Tagged_Parent);
3329 while Present (Pcomp) loop
3330 if Ekind_In (Pcomp, E_Discriminant, E_Component) then
3331 if Component_Bit_Offset (Pcomp) /= No_Uint
3332 and then Known_Static_Esize (Pcomp)
3333 then
3334 Parent_Last_Bit :=
3335 UI_Max
3336 (Parent_Last_Bit,
3337 Component_Bit_Offset (Pcomp) + Esize (Pcomp) - 1);
3338 end if;
3339
3340 Next_Entity (Pcomp);
3341 end if;
3342 end loop;
3343 end if;
3344 end;
3345
3346 -- All done if no component clauses
3347
3348 CC := First (Component_Clauses (N));
3349
3350 if No (CC) then
3351 return;
3352 end if;
3353
3354 -- If a tag is present, then create a component clause that places it
3355 -- at the start of the record (otherwise gigi may place it after other
3356 -- fields that have rep clauses).
3357
3358 Fent := First_Entity (Rectype);
3359
3360 if Nkind (Fent) = N_Defining_Identifier
3361 and then Chars (Fent) = Name_uTag
3362 then
3363 Set_Component_Bit_Offset (Fent, Uint_0);
3364 Set_Normalized_Position (Fent, Uint_0);
3365 Set_Normalized_First_Bit (Fent, Uint_0);
3366 Set_Normalized_Position_Max (Fent, Uint_0);
3367 Init_Esize (Fent, System_Address_Size);
3368
3369 Set_Component_Clause (Fent,
3370 Make_Component_Clause (Loc,
3371 Component_Name =>
3372 Make_Identifier (Loc,
3373 Chars => Name_uTag),
3374
3375 Position =>
3376 Make_Integer_Literal (Loc,
3377 Intval => Uint_0),
3378
3379 First_Bit =>
3380 Make_Integer_Literal (Loc,
3381 Intval => Uint_0),
3382
3383 Last_Bit =>
3384 Make_Integer_Literal (Loc,
3385 UI_From_Int (System_Address_Size))));
3386
3387 Ccount := Ccount + 1;
3388 end if;
3389
3390 Max_Bit_So_Far := Uint_Minus_1;
3391 Overlap_Check_Required := False;
3392
3393 -- Process the component clauses
3394
3395 while Present (CC) loop
3396 Find_Component;
3397
3398 if Present (Comp) then
3399 Ccount := Ccount + 1;
3400
3401 if Fbit <= Max_Bit_So_Far then
3402 Overlap_Check_Required := True;
3403 else
3404 Max_Bit_So_Far := Lbit;
3405 end if;
3406
3407 -- Check bit position out of range of specified size
3408
3409 if Has_Size_Clause (Rectype)
3410 and then Esize (Rectype) <= Lbit
3411 then
3412 Error_Msg_N
3413 ("bit number out of range of specified size",
3414 Last_Bit (CC));
3415
3416 -- Check for overlap with tag field
3417
3418 else
3419 if Is_Tagged_Type (Rectype)
3420 and then Fbit < System_Address_Size
3421 then
3422 Error_Msg_NE
3423 ("component overlaps tag field of&",
3424 Component_Name (CC), Rectype);
3425 end if;
3426
3427 if Hbit < Lbit then
3428 Hbit := Lbit;
3429 end if;
3430 end if;
3431
3432 -- Check parent overlap if component might overlap parent field
3433
3434 if Present (Tagged_Parent)
3435 and then Fbit <= Parent_Last_Bit
3436 then
3437 Pcomp := First_Component_Or_Discriminant (Tagged_Parent);
3438 while Present (Pcomp) loop
3439 if not Is_Tag (Pcomp)
3440 and then Chars (Pcomp) /= Name_uParent
3441 then
3442 Check_Component_Overlap (Comp, Pcomp);
3443 end if;
3444
3445 Next_Component_Or_Discriminant (Pcomp);
3446 end loop;
3447 end if;
3448 end if;
3449
3450 Next (CC);
3451 end loop;
3452
3453 -- Now that we have processed all the component clauses, check for
3454 -- overlap. We have to leave this till last, since the components can
3455 -- appear in any arbitrary order in the representation clause.
3456
3457 -- We do not need this check if all specified ranges were monotonic,
3458 -- as recorded by Overlap_Check_Required being False at this stage.
3459
3460 -- This first section checks if there are any overlapping entries at
3461 -- all. It does this by sorting all entries and then seeing if there are
3462 -- any overlaps. If there are none, then that is decisive, but if there
3463 -- are overlaps, they may still be OK (they may result from fields in
3464 -- different variants).
3465
3466 if Overlap_Check_Required then
3467 Overlap_Check1 : declare
3468
3469 OC_Fbit : array (0 .. Ccount) of Uint;
3470 -- First-bit values for component clauses, the value is the offset
3471 -- of the first bit of the field from start of record. The zero
3472 -- entry is for use in sorting.
3473
3474 OC_Lbit : array (0 .. Ccount) of Uint;
3475 -- Last-bit values for component clauses, the value is the offset
3476 -- of the last bit of the field from start of record. The zero
3477 -- entry is for use in sorting.
3478
3479 OC_Count : Natural := 0;
3480 -- Count of entries in OC_Fbit and OC_Lbit
3481
3482 function OC_Lt (Op1, Op2 : Natural) return Boolean;
3483 -- Compare routine for Sort
3484
3485 procedure OC_Move (From : Natural; To : Natural);
3486 -- Move routine for Sort
3487
3488 package Sorting is new GNAT.Heap_Sort_G (OC_Move, OC_Lt);
3489
3490 -----------
3491 -- OC_Lt --
3492 -----------
3493
3494 function OC_Lt (Op1, Op2 : Natural) return Boolean is
3495 begin
3496 return OC_Fbit (Op1) < OC_Fbit (Op2);
3497 end OC_Lt;
3498
3499 -------------
3500 -- OC_Move --
3501 -------------
3502
3503 procedure OC_Move (From : Natural; To : Natural) is
3504 begin
3505 OC_Fbit (To) := OC_Fbit (From);
3506 OC_Lbit (To) := OC_Lbit (From);
3507 end OC_Move;
3508
3509 -- Start of processing for Overlap_Check
3510
3511 begin
3512 CC := First (Component_Clauses (N));
3513 while Present (CC) loop
3514
3515 -- Exclude component clause already marked in error
3516
3517 if not Error_Posted (CC) then
3518 Find_Component;
3519
3520 if Present (Comp) then
3521 OC_Count := OC_Count + 1;
3522 OC_Fbit (OC_Count) := Fbit;
3523 OC_Lbit (OC_Count) := Lbit;
3524 end if;
3525 end if;
3526
3527 Next (CC);
3528 end loop;
3529
3530 Sorting.Sort (OC_Count);
3531
3532 Overlap_Check_Required := False;
3533 for J in 1 .. OC_Count - 1 loop
3534 if OC_Lbit (J) >= OC_Fbit (J + 1) then
3535 Overlap_Check_Required := True;
3536 exit;
3537 end if;
3538 end loop;
3539 end Overlap_Check1;
3540 end if;
3541
3542 -- If Overlap_Check_Required is still True, then we have to do the full
3543 -- scale overlap check, since we have at least two fields that do
3544 -- overlap, and we need to know if that is OK since they are in
3545 -- different variant, or whether we have a definite problem.
3546
3547 if Overlap_Check_Required then
3548 Overlap_Check2 : declare
3549 C1_Ent, C2_Ent : Entity_Id;
3550 -- Entities of components being checked for overlap
3551
3552 Clist : Node_Id;
3553 -- Component_List node whose Component_Items are being checked
3554
3555 Citem : Node_Id;
3556 -- Component declaration for component being checked
3557
3558 begin
3559 C1_Ent := First_Entity (Base_Type (Rectype));
3560
3561 -- Loop through all components in record. For each component check
3562 -- for overlap with any of the preceding elements on the component
3563 -- list containing the component and also, if the component is in
3564 -- a variant, check against components outside the case structure.
3565 -- This latter test is repeated recursively up the variant tree.
3566
3567 Main_Component_Loop : while Present (C1_Ent) loop
3568 if not Ekind_In (C1_Ent, E_Component, E_Discriminant) then
3569 goto Continue_Main_Component_Loop;
3570 end if;
3571
3572 -- Skip overlap check if entity has no declaration node. This
3573 -- happens with discriminants in constrained derived types.
3574 -- Probably we are missing some checks as a result, but that
3575 -- does not seem terribly serious ???
3576
3577 if No (Declaration_Node (C1_Ent)) then
3578 goto Continue_Main_Component_Loop;
3579 end if;
3580
3581 Clist := Parent (List_Containing (Declaration_Node (C1_Ent)));
3582
3583 -- Loop through component lists that need checking. Check the
3584 -- current component list and all lists in variants above us.
3585
3586 Component_List_Loop : loop
3587
3588 -- If derived type definition, go to full declaration
3589 -- If at outer level, check discriminants if there are any.
3590
3591 if Nkind (Clist) = N_Derived_Type_Definition then
3592 Clist := Parent (Clist);
3593 end if;
3594
3595 -- Outer level of record definition, check discriminants
3596
3597 if Nkind_In (Clist, N_Full_Type_Declaration,
3598 N_Private_Type_Declaration)
3599 then
3600 if Has_Discriminants (Defining_Identifier (Clist)) then
3601 C2_Ent :=
3602 First_Discriminant (Defining_Identifier (Clist));
3603 while Present (C2_Ent) loop
3604 exit when C1_Ent = C2_Ent;
3605 Check_Component_Overlap (C1_Ent, C2_Ent);
3606 Next_Discriminant (C2_Ent);
3607 end loop;
3608 end if;
3609
3610 -- Record extension case
3611
3612 elsif Nkind (Clist) = N_Derived_Type_Definition then
3613 Clist := Empty;
3614
3615 -- Otherwise check one component list
3616
3617 else
3618 Citem := First (Component_Items (Clist));
3619
3620 while Present (Citem) loop
3621 if Nkind (Citem) = N_Component_Declaration then
3622 C2_Ent := Defining_Identifier (Citem);
3623 exit when C1_Ent = C2_Ent;
3624 Check_Component_Overlap (C1_Ent, C2_Ent);
3625 end if;
3626
3627 Next (Citem);
3628 end loop;
3629 end if;
3630
3631 -- Check for variants above us (the parent of the Clist can
3632 -- be a variant, in which case its parent is a variant part,
3633 -- and the parent of the variant part is a component list
3634 -- whose components must all be checked against the current
3635 -- component for overlap).
3636
3637 if Nkind (Parent (Clist)) = N_Variant then
3638 Clist := Parent (Parent (Parent (Clist)));
3639
3640 -- Check for possible discriminant part in record, this
3641 -- is treated essentially as another level in the
3642 -- recursion. For this case the parent of the component
3643 -- list is the record definition, and its parent is the
3644 -- full type declaration containing the discriminant
3645 -- specifications.
3646
3647 elsif Nkind (Parent (Clist)) = N_Record_Definition then
3648 Clist := Parent (Parent ((Clist)));
3649
3650 -- If neither of these two cases, we are at the top of
3651 -- the tree.
3652
3653 else
3654 exit Component_List_Loop;
3655 end if;
3656 end loop Component_List_Loop;
3657
3658 <<Continue_Main_Component_Loop>>
3659 Next_Entity (C1_Ent);
3660
3661 end loop Main_Component_Loop;
3662 end Overlap_Check2;
3663 end if;
3664
3665 -- For records that have component clauses for all components, and whose
3666 -- size is less than or equal to 32, we need to know the size in the
3667 -- front end to activate possible packed array processing where the
3668 -- component type is a record.
3669
3670 -- At this stage Hbit + 1 represents the first unused bit from all the
3671 -- component clauses processed, so if the component clauses are
3672 -- complete, then this is the length of the record.
3673
3674 -- For records longer than System.Storage_Unit, and for those where not
3675 -- all components have component clauses, the back end determines the
3676 -- length (it may for example be appropriate to round up the size
3677 -- to some convenient boundary, based on alignment considerations, etc).
3678
3679 if Unknown_RM_Size (Rectype) and then Hbit + 1 <= 32 then
3680
3681 -- Nothing to do if at least one component has no component clause
3682
3683 Comp := First_Component_Or_Discriminant (Rectype);
3684 while Present (Comp) loop
3685 exit when No (Component_Clause (Comp));
3686 Next_Component_Or_Discriminant (Comp);
3687 end loop;
3688
3689 -- If we fall out of loop, all components have component clauses
3690 -- and so we can set the size to the maximum value.
3691
3692 if No (Comp) then
3693 Set_RM_Size (Rectype, Hbit + 1);
3694 end if;
3695 end if;
3696 end Check_Record_Representation_Clause;
3697
d6f39728 3698 ----------------
3699 -- Check_Size --
3700 ----------------
3701
3702 procedure Check_Size
3703 (N : Node_Id;
3704 T : Entity_Id;
3705 Siz : Uint;
3706 Biased : out Boolean)
3707 is
3708 UT : constant Entity_Id := Underlying_Type (T);
3709 M : Uint;
3710
3711 begin
3712 Biased := False;
3713
ea61a7ea 3714 -- Dismiss cases for generic types or types with previous errors
d6f39728 3715
3716 if No (UT)
3717 or else UT = Any_Type
3718 or else Is_Generic_Type (UT)
3719 or else Is_Generic_Type (Root_Type (UT))
d6f39728 3720 then
3721 return;
3722
ea61a7ea 3723 -- Check case of bit packed array
3724
3725 elsif Is_Array_Type (UT)
3726 and then Known_Static_Component_Size (UT)
3727 and then Is_Bit_Packed_Array (UT)
3728 then
3729 declare
3730 Asiz : Uint;
3731 Indx : Node_Id;
3732 Ityp : Entity_Id;
3733
3734 begin
3735 Asiz := Component_Size (UT);
3736 Indx := First_Index (UT);
3737 loop
3738 Ityp := Etype (Indx);
3739
3740 -- If non-static bound, then we are not in the business of
3741 -- trying to check the length, and indeed an error will be
3742 -- issued elsewhere, since sizes of non-static array types
3743 -- cannot be set implicitly or explicitly.
3744
3745 if not Is_Static_Subtype (Ityp) then
3746 return;
3747 end if;
3748
3749 -- Otherwise accumulate next dimension
3750
3751 Asiz := Asiz * (Expr_Value (Type_High_Bound (Ityp)) -
3752 Expr_Value (Type_Low_Bound (Ityp)) +
3753 Uint_1);
3754
3755 Next_Index (Indx);
3756 exit when No (Indx);
3757 end loop;
3758
3759 if Asiz <= Siz then
3760 return;
3761 else
3762 Error_Msg_Uint_1 := Asiz;
3763 Error_Msg_NE
3764 ("size for& too small, minimum allowed is ^", N, T);
37cb33b0 3765 Set_Esize (T, Asiz);
3766 Set_RM_Size (T, Asiz);
ea61a7ea 3767 end if;
3768 end;
3769
3770 -- All other composite types are ignored
3771
3772 elsif Is_Composite_Type (UT) then
3773 return;
3774
d6f39728 3775 -- For fixed-point types, don't check minimum if type is not frozen,
ea61a7ea 3776 -- since we don't know all the characteristics of the type that can
3777 -- affect the size (e.g. a specified small) till freeze time.
d6f39728 3778
3779 elsif Is_Fixed_Point_Type (UT)
3780 and then not Is_Frozen (UT)
3781 then
3782 null;
3783
3784 -- Cases for which a minimum check is required
3785
3786 else
ea61a7ea 3787 -- Ignore if specified size is correct for the type
3788
3789 if Known_Esize (UT) and then Siz = Esize (UT) then
3790 return;
3791 end if;
3792
3793 -- Otherwise get minimum size
3794
d6f39728 3795 M := UI_From_Int (Minimum_Size (UT));
3796
3797 if Siz < M then
3798
3799 -- Size is less than minimum size, but one possibility remains
fdd294d1 3800 -- that we can manage with the new size if we bias the type.
d6f39728 3801
3802 M := UI_From_Int (Minimum_Size (UT, Biased => True));
3803
3804 if Siz < M then
3805 Error_Msg_Uint_1 := M;
3806 Error_Msg_NE
3807 ("size for& too small, minimum allowed is ^", N, T);
37cb33b0 3808 Set_Esize (T, M);
3809 Set_RM_Size (T, M);
d6f39728 3810 else
3811 Biased := True;
3812 end if;
3813 end if;
3814 end if;
3815 end Check_Size;
3816
3817 -------------------------
3818 -- Get_Alignment_Value --
3819 -------------------------
3820
3821 function Get_Alignment_Value (Expr : Node_Id) return Uint is
3822 Align : constant Uint := Static_Integer (Expr);
3823
3824 begin
3825 if Align = No_Uint then
3826 return No_Uint;
3827
3828 elsif Align <= 0 then
3829 Error_Msg_N ("alignment value must be positive", Expr);
3830 return No_Uint;
3831
3832 else
3833 for J in Int range 0 .. 64 loop
3834 declare
3835 M : constant Uint := Uint_2 ** J;
3836
3837 begin
3838 exit when M = Align;
3839
3840 if M > Align then
3841 Error_Msg_N
3842 ("alignment value must be power of 2", Expr);
3843 return No_Uint;
3844 end if;
3845 end;
3846 end loop;
3847
3848 return Align;
3849 end if;
3850 end Get_Alignment_Value;
3851
d6f39728 3852 ----------------
3853 -- Initialize --
3854 ----------------
3855
3856 procedure Initialize is
3857 begin
3858 Unchecked_Conversions.Init;
3859 end Initialize;
3860
3861 -------------------------
3862 -- Is_Operational_Item --
3863 -------------------------
3864
3865 function Is_Operational_Item (N : Node_Id) return Boolean is
3866 begin
3867 if Nkind (N) /= N_Attribute_Definition_Clause then
3868 return False;
3869 else
3870 declare
3871 Id : constant Attribute_Id := Get_Attribute_Id (Chars (N));
d6f39728 3872 begin
fdd294d1 3873 return Id = Attribute_Input
d6f39728 3874 or else Id = Attribute_Output
3875 or else Id = Attribute_Read
f15731c4 3876 or else Id = Attribute_Write
3877 or else Id = Attribute_External_Tag;
d6f39728 3878 end;
3879 end if;
3880 end Is_Operational_Item;
3881
3882 ------------------
3883 -- Minimum_Size --
3884 ------------------
3885
3886 function Minimum_Size
3887 (T : Entity_Id;
d5b349fa 3888 Biased : Boolean := False) return Nat
d6f39728 3889 is
3890 Lo : Uint := No_Uint;
3891 Hi : Uint := No_Uint;
3892 LoR : Ureal := No_Ureal;
3893 HiR : Ureal := No_Ureal;
3894 LoSet : Boolean := False;
3895 HiSet : Boolean := False;
3896 B : Uint;
3897 S : Nat;
3898 Ancest : Entity_Id;
f15731c4 3899 R_Typ : constant Entity_Id := Root_Type (T);
d6f39728 3900
3901 begin
3902 -- If bad type, return 0
3903
3904 if T = Any_Type then
3905 return 0;
3906
3907 -- For generic types, just return zero. There cannot be any legitimate
3908 -- need to know such a size, but this routine may be called with a
3909 -- generic type as part of normal processing.
3910
f15731c4 3911 elsif Is_Generic_Type (R_Typ)
3912 or else R_Typ = Any_Type
3913 then
d6f39728 3914 return 0;
3915
93735cb8 3916 -- Access types. Normally an access type cannot have a size smaller
3917 -- than the size of System.Address. The exception is on VMS, where
3918 -- we have short and long addresses, and it is possible for an access
3919 -- type to have a short address size (and thus be less than the size
3920 -- of System.Address itself). We simply skip the check for VMS, and
fdd294d1 3921 -- leave it to the back end to do the check.
d6f39728 3922
3923 elsif Is_Access_Type (T) then
93735cb8 3924 if OpenVMS_On_Target then
3925 return 0;
3926 else
3927 return System_Address_Size;
3928 end if;
d6f39728 3929
3930 -- Floating-point types
3931
3932 elsif Is_Floating_Point_Type (T) then
f15731c4 3933 return UI_To_Int (Esize (R_Typ));
d6f39728 3934
3935 -- Discrete types
3936
3937 elsif Is_Discrete_Type (T) then
3938
fdd294d1 3939 -- The following loop is looking for the nearest compile time known
3940 -- bounds following the ancestor subtype chain. The idea is to find
3941 -- the most restrictive known bounds information.
d6f39728 3942
3943 Ancest := T;
3944 loop
3945 if Ancest = Any_Type or else Etype (Ancest) = Any_Type then
3946 return 0;
3947 end if;
3948
3949 if not LoSet then
3950 if Compile_Time_Known_Value (Type_Low_Bound (Ancest)) then
3951 Lo := Expr_Rep_Value (Type_Low_Bound (Ancest));
3952 LoSet := True;
3953 exit when HiSet;
3954 end if;
3955 end if;
3956
3957 if not HiSet then
3958 if Compile_Time_Known_Value (Type_High_Bound (Ancest)) then
3959 Hi := Expr_Rep_Value (Type_High_Bound (Ancest));
3960 HiSet := True;
3961 exit when LoSet;
3962 end if;
3963 end if;
3964
3965 Ancest := Ancestor_Subtype (Ancest);
3966
3967 if No (Ancest) then
3968 Ancest := Base_Type (T);
3969
3970 if Is_Generic_Type (Ancest) then
3971 return 0;
3972 end if;
3973 end if;
3974 end loop;
3975
3976 -- Fixed-point types. We can't simply use Expr_Value to get the
fdd294d1 3977 -- Corresponding_Integer_Value values of the bounds, since these do not
3978 -- get set till the type is frozen, and this routine can be called
3979 -- before the type is frozen. Similarly the test for bounds being static
3980 -- needs to include the case where we have unanalyzed real literals for
3981 -- the same reason.
d6f39728 3982
3983 elsif Is_Fixed_Point_Type (T) then
3984
fdd294d1 3985 -- The following loop is looking for the nearest compile time known
3986 -- bounds following the ancestor subtype chain. The idea is to find
3987 -- the most restrictive known bounds information.
d6f39728 3988
3989 Ancest := T;
3990 loop
3991 if Ancest = Any_Type or else Etype (Ancest) = Any_Type then
3992 return 0;
3993 end if;
3994
3062c401 3995 -- Note: In the following two tests for LoSet and HiSet, it may
3996 -- seem redundant to test for N_Real_Literal here since normally
3997 -- one would assume that the test for the value being known at
3998 -- compile time includes this case. However, there is a glitch.
3999 -- If the real literal comes from folding a non-static expression,
4000 -- then we don't consider any non- static expression to be known
4001 -- at compile time if we are in configurable run time mode (needed
4002 -- in some cases to give a clearer definition of what is and what
4003 -- is not accepted). So the test is indeed needed. Without it, we
4004 -- would set neither Lo_Set nor Hi_Set and get an infinite loop.
4005
d6f39728 4006 if not LoSet then
4007 if Nkind (Type_Low_Bound (Ancest)) = N_Real_Literal
4008 or else Compile_Time_Known_Value (Type_Low_Bound (Ancest))
4009 then
4010 LoR := Expr_Value_R (Type_Low_Bound (Ancest));
4011 LoSet := True;
4012 exit when HiSet;
4013 end if;
4014 end if;
4015
4016 if not HiSet then
4017 if Nkind (Type_High_Bound (Ancest)) = N_Real_Literal
4018 or else Compile_Time_Known_Value (Type_High_Bound (Ancest))
4019 then
4020 HiR := Expr_Value_R (Type_High_Bound (Ancest));
4021 HiSet := True;
4022 exit when LoSet;
4023 end if;
4024 end if;
4025
4026 Ancest := Ancestor_Subtype (Ancest);
4027
4028 if No (Ancest) then
4029 Ancest := Base_Type (T);
4030
4031 if Is_Generic_Type (Ancest) then
4032 return 0;
4033 end if;
4034 end if;
4035 end loop;
4036
4037 Lo := UR_To_Uint (LoR / Small_Value (T));
4038 Hi := UR_To_Uint (HiR / Small_Value (T));
4039
4040 -- No other types allowed
4041
4042 else
4043 raise Program_Error;
4044 end if;
4045
2866d595 4046 -- Fall through with Hi and Lo set. Deal with biased case
d6f39728 4047
cc46ff4b 4048 if (Biased
4049 and then not Is_Fixed_Point_Type (T)
4050 and then not (Is_Enumeration_Type (T)
4051 and then Has_Non_Standard_Rep (T)))
d6f39728 4052 or else Has_Biased_Representation (T)
4053 then
4054 Hi := Hi - Lo;
4055 Lo := Uint_0;
4056 end if;
4057
4058 -- Signed case. Note that we consider types like range 1 .. -1 to be
fdd294d1 4059 -- signed for the purpose of computing the size, since the bounds have
1a34e48c 4060 -- to be accommodated in the base type.
d6f39728 4061
4062 if Lo < 0 or else Hi < 0 then
4063 S := 1;
4064 B := Uint_1;
4065
da253936 4066 -- S = size, B = 2 ** (size - 1) (can accommodate -B .. +(B - 1))
4067 -- Note that we accommodate the case where the bounds cross. This
d6f39728 4068 -- can happen either because of the way the bounds are declared
4069 -- or because of the algorithm in Freeze_Fixed_Point_Type.
4070
4071 while Lo < -B
4072 or else Hi < -B
4073 or else Lo >= B
4074 or else Hi >= B
4075 loop
4076 B := Uint_2 ** S;
4077 S := S + 1;
4078 end loop;
4079
4080 -- Unsigned case
4081
4082 else
4083 -- If both bounds are positive, make sure that both are represen-
4084 -- table in the case where the bounds are crossed. This can happen
4085 -- either because of the way the bounds are declared, or because of
4086 -- the algorithm in Freeze_Fixed_Point_Type.
4087
4088 if Lo > Hi then
4089 Hi := Lo;
4090 end if;
4091
da253936 4092 -- S = size, (can accommodate 0 .. (2**size - 1))
d6f39728 4093
4094 S := 0;
4095 while Hi >= Uint_2 ** S loop
4096 S := S + 1;
4097 end loop;
4098 end if;
4099
4100 return S;
4101 end Minimum_Size;
4102
44e4341e 4103 ---------------------------
4104 -- New_Stream_Subprogram --
4105 ---------------------------
d6f39728 4106
44e4341e 4107 procedure New_Stream_Subprogram
4108 (N : Node_Id;
4109 Ent : Entity_Id;
4110 Subp : Entity_Id;
4111 Nam : TSS_Name_Type)
d6f39728 4112 is
4113 Loc : constant Source_Ptr := Sloc (N);
9dfe12ae 4114 Sname : constant Name_Id := Make_TSS_Name (Base_Type (Ent), Nam);
f15731c4 4115 Subp_Id : Entity_Id;
d6f39728 4116 Subp_Decl : Node_Id;
4117 F : Entity_Id;
4118 Etyp : Entity_Id;
4119
44e4341e 4120 Defer_Declaration : constant Boolean :=
4121 Is_Tagged_Type (Ent) or else Is_Private_Type (Ent);
4122 -- For a tagged type, there is a declaration for each stream attribute
4123 -- at the freeze point, and we must generate only a completion of this
4124 -- declaration. We do the same for private types, because the full view
4125 -- might be tagged. Otherwise we generate a declaration at the point of
4126 -- the attribute definition clause.
4127
f15731c4 4128 function Build_Spec return Node_Id;
4129 -- Used for declaration and renaming declaration, so that this is
4130 -- treated as a renaming_as_body.
4131
4132 ----------------
4133 -- Build_Spec --
4134 ----------------
4135
d5b349fa 4136 function Build_Spec return Node_Id is
44e4341e 4137 Out_P : constant Boolean := (Nam = TSS_Stream_Read);
4138 Formals : List_Id;
4139 Spec : Node_Id;
4140 T_Ref : constant Node_Id := New_Reference_To (Etyp, Loc);
4141
f15731c4 4142 begin
9dfe12ae 4143 Subp_Id := Make_Defining_Identifier (Loc, Sname);
f15731c4 4144
44e4341e 4145 -- S : access Root_Stream_Type'Class
4146
4147 Formals := New_List (
4148 Make_Parameter_Specification (Loc,
4149 Defining_Identifier =>
4150 Make_Defining_Identifier (Loc, Name_S),
4151 Parameter_Type =>
4152 Make_Access_Definition (Loc,
4153 Subtype_Mark =>
4154 New_Reference_To (
4155 Designated_Type (Etype (F)), Loc))));
4156
4157 if Nam = TSS_Stream_Input then
4158 Spec := Make_Function_Specification (Loc,
4159 Defining_Unit_Name => Subp_Id,
4160 Parameter_Specifications => Formals,
4161 Result_Definition => T_Ref);
4162 else
4163 -- V : [out] T
f15731c4 4164
44e4341e 4165 Append_To (Formals,
4166 Make_Parameter_Specification (Loc,
4167 Defining_Identifier => Make_Defining_Identifier (Loc, Name_V),
4168 Out_Present => Out_P,
4169 Parameter_Type => T_Ref));
f15731c4 4170
d3ef794c 4171 Spec :=
4172 Make_Procedure_Specification (Loc,
4173 Defining_Unit_Name => Subp_Id,
4174 Parameter_Specifications => Formals);
44e4341e 4175 end if;
f15731c4 4176
44e4341e 4177 return Spec;
4178 end Build_Spec;
d6f39728 4179
44e4341e 4180 -- Start of processing for New_Stream_Subprogram
d6f39728 4181
44e4341e 4182 begin
4183 F := First_Formal (Subp);
4184
4185 if Ekind (Subp) = E_Procedure then
4186 Etyp := Etype (Next_Formal (F));
d6f39728 4187 else
44e4341e 4188 Etyp := Etype (Subp);
d6f39728 4189 end if;
f15731c4 4190
44e4341e 4191 -- Prepare subprogram declaration and insert it as an action on the
4192 -- clause node. The visibility for this entity is used to test for
4193 -- visibility of the attribute definition clause (in the sense of
4194 -- 8.3(23) as amended by AI-195).
9dfe12ae 4195
44e4341e 4196 if not Defer_Declaration then
f15731c4 4197 Subp_Decl :=
4198 Make_Subprogram_Declaration (Loc,
4199 Specification => Build_Spec);
44e4341e 4200
4201 -- For a tagged type, there is always a visible declaration for each
15ebb600 4202 -- stream TSS (it is a predefined primitive operation), and the
44e4341e 4203 -- completion of this declaration occurs at the freeze point, which is
4204 -- not always visible at places where the attribute definition clause is
4205 -- visible. So, we create a dummy entity here for the purpose of
4206 -- tracking the visibility of the attribute definition clause itself.
4207
4208 else
4209 Subp_Id :=
4210 Make_Defining_Identifier (Loc,
4211 Chars => New_External_Name (Sname, 'V'));
4212 Subp_Decl :=
4213 Make_Object_Declaration (Loc,
4214 Defining_Identifier => Subp_Id,
4215 Object_Definition => New_Occurrence_Of (Standard_Boolean, Loc));
f15731c4 4216 end if;
4217
44e4341e 4218 Insert_Action (N, Subp_Decl);
4219 Set_Entity (N, Subp_Id);
4220
d6f39728 4221 Subp_Decl :=
4222 Make_Subprogram_Renaming_Declaration (Loc,
f15731c4 4223 Specification => Build_Spec,
4224 Name => New_Reference_To (Subp, Loc));
d6f39728 4225
44e4341e 4226 if Defer_Declaration then
d6f39728 4227 Set_TSS (Base_Type (Ent), Subp_Id);
4228 else
4229 Insert_Action (N, Subp_Decl);
4230 Copy_TSS (Subp_Id, Base_Type (Ent));
4231 end if;
44e4341e 4232 end New_Stream_Subprogram;
d6f39728 4233
d6f39728 4234 ------------------------
4235 -- Rep_Item_Too_Early --
4236 ------------------------
4237
80d4fec4 4238 function Rep_Item_Too_Early (T : Entity_Id; N : Node_Id) return Boolean is
d6f39728 4239 begin
44e4341e 4240 -- Cannot apply non-operational rep items to generic types
d6f39728 4241
f15731c4 4242 if Is_Operational_Item (N) then
4243 return False;
4244
4245 elsif Is_Type (T)
d6f39728 4246 and then Is_Generic_Type (Root_Type (T))
4247 then
4248 Error_Msg_N
4249 ("representation item not allowed for generic type", N);
4250 return True;
4251 end if;
4252
fdd294d1 4253 -- Otherwise check for incomplete type
d6f39728 4254
4255 if Is_Incomplete_Or_Private_Type (T)
4256 and then No (Underlying_Type (T))
4257 then
4258 Error_Msg_N
4259 ("representation item must be after full type declaration", N);
4260 return True;
4261
1a34e48c 4262 -- If the type has incomplete components, a representation clause is
d6f39728 4263 -- illegal but stream attributes and Convention pragmas are correct.
4264
4265 elsif Has_Private_Component (T) then
f15731c4 4266 if Nkind (N) = N_Pragma then
d6f39728 4267 return False;
4268 else
4269 Error_Msg_N
4270 ("representation item must appear after type is fully defined",
4271 N);
4272 return True;
4273 end if;
4274 else
4275 return False;
4276 end if;
4277 end Rep_Item_Too_Early;
4278
4279 -----------------------
4280 -- Rep_Item_Too_Late --
4281 -----------------------
4282
4283 function Rep_Item_Too_Late
4284 (T : Entity_Id;
4285 N : Node_Id;
d5b349fa 4286 FOnly : Boolean := False) return Boolean
d6f39728 4287 is
4288 S : Entity_Id;
4289 Parent_Type : Entity_Id;
4290
4291 procedure Too_Late;
d53a018a 4292 -- Output the too late message. Note that this is not considered a
4293 -- serious error, since the effect is simply that we ignore the
4294 -- representation clause in this case.
4295
4296 --------------
4297 -- Too_Late --
4298 --------------
d6f39728 4299
4300 procedure Too_Late is
4301 begin
d53a018a 4302 Error_Msg_N ("|representation item appears too late!", N);
d6f39728 4303 end Too_Late;
4304
4305 -- Start of processing for Rep_Item_Too_Late
4306
4307 begin
4308 -- First make sure entity is not frozen (RM 13.1(9)). Exclude imported
4309 -- types, which may be frozen if they appear in a representation clause
4310 -- for a local type.
4311
4312 if Is_Frozen (T)
4313 and then not From_With_Type (T)
4314 then
4315 Too_Late;
4316 S := First_Subtype (T);
4317
4318 if Present (Freeze_Node (S)) then
4319 Error_Msg_NE
87d5c1d0 4320 ("?no more representation items for }", Freeze_Node (S), S);
d6f39728 4321 end if;
4322
4323 return True;
4324
4325 -- Check for case of non-tagged derived type whose parent either has
4326 -- primitive operations, or is a by reference type (RM 13.1(10)).
4327
4328 elsif Is_Type (T)
4329 and then not FOnly
4330 and then Is_Derived_Type (T)
4331 and then not Is_Tagged_Type (T)
4332 then
4333 Parent_Type := Etype (Base_Type (T));
4334
4335 if Has_Primitive_Operations (Parent_Type) then
4336 Too_Late;
4337 Error_Msg_NE
4338 ("primitive operations already defined for&!", N, Parent_Type);
4339 return True;
4340
4341 elsif Is_By_Reference_Type (Parent_Type) then
4342 Too_Late;
4343 Error_Msg_NE
4344 ("parent type & is a by reference type!", N, Parent_Type);
4345 return True;
4346 end if;
4347 end if;
4348
3062c401 4349 -- No error, link item into head of chain of rep items for the entity,
4350 -- but avoid chaining if we have an overloadable entity, and the pragma
4351 -- is one that can apply to multiple overloaded entities.
4352
4353 if Is_Overloadable (T)
4354 and then Nkind (N) = N_Pragma
3062c401 4355 then
fdd294d1 4356 declare
4357 Pname : constant Name_Id := Pragma_Name (N);
4358 begin
4359 if Pname = Name_Convention or else
4360 Pname = Name_Import or else
4361 Pname = Name_Export or else
4362 Pname = Name_External or else
4363 Pname = Name_Interface
4364 then
4365 return False;
4366 end if;
4367 end;
3062c401 4368 end if;
4369
fdd294d1 4370 Record_Rep_Item (T, N);
d6f39728 4371 return False;
4372 end Rep_Item_Too_Late;
4373
4374 -------------------------
4375 -- Same_Representation --
4376 -------------------------
4377
4378 function Same_Representation (Typ1, Typ2 : Entity_Id) return Boolean is
4379 T1 : constant Entity_Id := Underlying_Type (Typ1);
4380 T2 : constant Entity_Id := Underlying_Type (Typ2);
4381
4382 begin
4383 -- A quick check, if base types are the same, then we definitely have
4384 -- the same representation, because the subtype specific representation
4385 -- attributes (Size and Alignment) do not affect representation from
4386 -- the point of view of this test.
4387
4388 if Base_Type (T1) = Base_Type (T2) then
4389 return True;
4390
4391 elsif Is_Private_Type (Base_Type (T2))
4392 and then Base_Type (T1) = Full_View (Base_Type (T2))
4393 then
4394 return True;
4395 end if;
4396
4397 -- Tagged types never have differing representations
4398
4399 if Is_Tagged_Type (T1) then
4400 return True;
4401 end if;
4402
4403 -- Representations are definitely different if conventions differ
4404
4405 if Convention (T1) /= Convention (T2) then
4406 return False;
4407 end if;
4408
4409 -- Representations are different if component alignments differ
4410
4411 if (Is_Record_Type (T1) or else Is_Array_Type (T1))
4412 and then
4413 (Is_Record_Type (T2) or else Is_Array_Type (T2))
4414 and then Component_Alignment (T1) /= Component_Alignment (T2)
4415 then
4416 return False;
4417 end if;
4418
4419 -- For arrays, the only real issue is component size. If we know the
4420 -- component size for both arrays, and it is the same, then that's
4421 -- good enough to know we don't have a change of representation.
4422
4423 if Is_Array_Type (T1) then
4424 if Known_Component_Size (T1)
4425 and then Known_Component_Size (T2)
4426 and then Component_Size (T1) = Component_Size (T2)
4427 then
4428 return True;
4429 end if;
4430 end if;
4431
4432 -- Types definitely have same representation if neither has non-standard
4433 -- representation since default representations are always consistent.
4434 -- If only one has non-standard representation, and the other does not,
4435 -- then we consider that they do not have the same representation. They
4436 -- might, but there is no way of telling early enough.
4437
4438 if Has_Non_Standard_Rep (T1) then
4439 if not Has_Non_Standard_Rep (T2) then
4440 return False;
4441 end if;
4442 else
4443 return not Has_Non_Standard_Rep (T2);
4444 end if;
4445
fdd294d1 4446 -- Here the two types both have non-standard representation, and we need
4447 -- to determine if they have the same non-standard representation.
d6f39728 4448
4449 -- For arrays, we simply need to test if the component sizes are the
4450 -- same. Pragma Pack is reflected in modified component sizes, so this
4451 -- check also deals with pragma Pack.
4452
4453 if Is_Array_Type (T1) then
4454 return Component_Size (T1) = Component_Size (T2);
4455
4456 -- Tagged types always have the same representation, because it is not
4457 -- possible to specify different representations for common fields.
4458
4459 elsif Is_Tagged_Type (T1) then
4460 return True;
4461
4462 -- Case of record types
4463
4464 elsif Is_Record_Type (T1) then
4465
4466 -- Packed status must conform
4467
4468 if Is_Packed (T1) /= Is_Packed (T2) then
4469 return False;
4470
4471 -- Otherwise we must check components. Typ2 maybe a constrained
4472 -- subtype with fewer components, so we compare the components
4473 -- of the base types.
4474
4475 else
4476 Record_Case : declare
4477 CD1, CD2 : Entity_Id;
4478
4479 function Same_Rep return Boolean;
4480 -- CD1 and CD2 are either components or discriminants. This
4481 -- function tests whether the two have the same representation
4482
80d4fec4 4483 --------------
4484 -- Same_Rep --
4485 --------------
4486
d6f39728 4487 function Same_Rep return Boolean is
4488 begin
4489 if No (Component_Clause (CD1)) then
4490 return No (Component_Clause (CD2));
4491
4492 else
4493 return
4494 Present (Component_Clause (CD2))
4495 and then
4496 Component_Bit_Offset (CD1) = Component_Bit_Offset (CD2)
4497 and then
4498 Esize (CD1) = Esize (CD2);
4499 end if;
4500 end Same_Rep;
4501
1e35409d 4502 -- Start of processing for Record_Case
d6f39728 4503
4504 begin
4505 if Has_Discriminants (T1) then
4506 CD1 := First_Discriminant (T1);
4507 CD2 := First_Discriminant (T2);
4508
9dfe12ae 4509 -- The number of discriminants may be different if the
4510 -- derived type has fewer (constrained by values). The
4511 -- invisible discriminants retain the representation of
4512 -- the original, so the discrepancy does not per se
4513 -- indicate a different representation.
4514
4515 while Present (CD1)
4516 and then Present (CD2)
4517 loop
d6f39728 4518 if not Same_Rep then
4519 return False;
4520 else
4521 Next_Discriminant (CD1);
4522 Next_Discriminant (CD2);
4523 end if;
4524 end loop;
4525 end if;
4526
4527 CD1 := First_Component (Underlying_Type (Base_Type (T1)));
4528 CD2 := First_Component (Underlying_Type (Base_Type (T2)));
4529
4530 while Present (CD1) loop
4531 if not Same_Rep then
4532 return False;
4533 else
4534 Next_Component (CD1);
4535 Next_Component (CD2);
4536 end if;
4537 end loop;
4538
4539 return True;
4540 end Record_Case;
4541 end if;
4542
4543 -- For enumeration types, we must check each literal to see if the
4544 -- representation is the same. Note that we do not permit enumeration
1a34e48c 4545 -- representation clauses for Character and Wide_Character, so these
d6f39728 4546 -- cases were already dealt with.
4547
4548 elsif Is_Enumeration_Type (T1) then
4549
4550 Enumeration_Case : declare
4551 L1, L2 : Entity_Id;
4552
4553 begin
4554 L1 := First_Literal (T1);
4555 L2 := First_Literal (T2);
4556
4557 while Present (L1) loop
4558 if Enumeration_Rep (L1) /= Enumeration_Rep (L2) then
4559 return False;
4560 else
4561 Next_Literal (L1);
4562 Next_Literal (L2);
4563 end if;
4564 end loop;
4565
4566 return True;
4567
4568 end Enumeration_Case;
4569
4570 -- Any other types have the same representation for these purposes
4571
4572 else
4573 return True;
4574 end if;
d6f39728 4575 end Same_Representation;
4576
4577 --------------------
4578 -- Set_Enum_Esize --
4579 --------------------
4580
4581 procedure Set_Enum_Esize (T : Entity_Id) is
4582 Lo : Uint;
4583 Hi : Uint;
4584 Sz : Nat;
4585
4586 begin
4587 Init_Alignment (T);
4588
4589 -- Find the minimum standard size (8,16,32,64) that fits
4590
4591 Lo := Enumeration_Rep (Entity (Type_Low_Bound (T)));
4592 Hi := Enumeration_Rep (Entity (Type_High_Bound (T)));
4593
4594 if Lo < 0 then
4595 if Lo >= -Uint_2**07 and then Hi < Uint_2**07 then
f15731c4 4596 Sz := Standard_Character_Size; -- May be > 8 on some targets
d6f39728 4597
4598 elsif Lo >= -Uint_2**15 and then Hi < Uint_2**15 then
4599 Sz := 16;
4600
4601 elsif Lo >= -Uint_2**31 and then Hi < Uint_2**31 then
4602 Sz := 32;
4603
4604 else pragma Assert (Lo >= -Uint_2**63 and then Hi < Uint_2**63);
4605 Sz := 64;
4606 end if;
4607
4608 else
4609 if Hi < Uint_2**08 then
f15731c4 4610 Sz := Standard_Character_Size; -- May be > 8 on some targets
d6f39728 4611
4612 elsif Hi < Uint_2**16 then
4613 Sz := 16;
4614
4615 elsif Hi < Uint_2**32 then
4616 Sz := 32;
4617
4618 else pragma Assert (Hi < Uint_2**63);
4619 Sz := 64;
4620 end if;
4621 end if;
4622
4623 -- That minimum is the proper size unless we have a foreign convention
4624 -- and the size required is 32 or less, in which case we bump the size
4625 -- up to 32. This is required for C and C++ and seems reasonable for
4626 -- all other foreign conventions.
4627
4628 if Has_Foreign_Convention (T)
4629 and then Esize (T) < Standard_Integer_Size
4630 then
4631 Init_Esize (T, Standard_Integer_Size);
d6f39728 4632 else
4633 Init_Esize (T, Sz);
4634 end if;
d6f39728 4635 end Set_Enum_Esize;
4636
83f8f0a6 4637 ------------------------------
4638 -- Validate_Address_Clauses --
4639 ------------------------------
4640
4641 procedure Validate_Address_Clauses is
4642 begin
4643 for J in Address_Clause_Checks.First .. Address_Clause_Checks.Last loop
4644 declare
4645 ACCR : Address_Clause_Check_Record
4646 renames Address_Clause_Checks.Table (J);
4647
d6da7448 4648 Expr : Node_Id;
4649
83f8f0a6 4650 X_Alignment : Uint;
4651 Y_Alignment : Uint;
4652
4653 X_Size : Uint;
4654 Y_Size : Uint;
4655
4656 begin
4657 -- Skip processing of this entry if warning already posted
4658
4659 if not Address_Warning_Posted (ACCR.N) then
4660
d6da7448 4661 Expr := Original_Node (Expression (ACCR.N));
83f8f0a6 4662
d6da7448 4663 -- Get alignments
83f8f0a6 4664
d6da7448 4665 X_Alignment := Alignment (ACCR.X);
4666 Y_Alignment := Alignment (ACCR.Y);
83f8f0a6 4667
4668 -- Similarly obtain sizes
4669
d6da7448 4670 X_Size := Esize (ACCR.X);
4671 Y_Size := Esize (ACCR.Y);
83f8f0a6 4672
4673 -- Check for large object overlaying smaller one
4674
4675 if Y_Size > Uint_0
4676 and then X_Size > Uint_0
4677 and then X_Size > Y_Size
4678 then
d6da7448 4679 Error_Msg_NE
4680 ("?& overlays smaller object", ACCR.N, ACCR.X);
83f8f0a6 4681 Error_Msg_N
d6da7448 4682 ("\?program execution may be erroneous", ACCR.N);
83f8f0a6 4683 Error_Msg_Uint_1 := X_Size;
4684 Error_Msg_NE
4685 ("\?size of & is ^", ACCR.N, ACCR.X);
4686 Error_Msg_Uint_1 := Y_Size;
4687 Error_Msg_NE
4688 ("\?size of & is ^", ACCR.N, ACCR.Y);
4689
d6da7448 4690 -- Check for inadequate alignment, both of the base object
4691 -- and of the offset, if any.
83f8f0a6 4692
d6da7448 4693 -- Note: we do not check the alignment if we gave a size
4694 -- warning, since it would likely be redundant.
83f8f0a6 4695
4696 elsif Y_Alignment /= Uint_0
d6da7448 4697 and then (Y_Alignment < X_Alignment
4698 or else (ACCR.Off
4699 and then
4700 Nkind (Expr) = N_Attribute_Reference
4701 and then
4702 Attribute_Name (Expr) = Name_Address
4703 and then
4704 Has_Compatible_Alignment
4705 (ACCR.X, Prefix (Expr))
4706 /= Known_Compatible))
83f8f0a6 4707 then
4708 Error_Msg_NE
4709 ("?specified address for& may be inconsistent "
4710 & "with alignment",
4711 ACCR.N, ACCR.X);
4712 Error_Msg_N
4713 ("\?program execution may be erroneous (RM 13.3(27))",
4714 ACCR.N);
4715 Error_Msg_Uint_1 := X_Alignment;
4716 Error_Msg_NE
4717 ("\?alignment of & is ^",
4718 ACCR.N, ACCR.X);
4719 Error_Msg_Uint_1 := Y_Alignment;
4720 Error_Msg_NE
4721 ("\?alignment of & is ^",
4722 ACCR.N, ACCR.Y);
d6da7448 4723 if Y_Alignment >= X_Alignment then
4724 Error_Msg_N
4725 ("\?but offset is not multiple of alignment",
4726 ACCR.N);
4727 end if;
83f8f0a6 4728 end if;
4729 end if;
4730 end;
4731 end loop;
4732 end Validate_Address_Clauses;
4733
d6f39728 4734 -----------------------------------
4735 -- Validate_Unchecked_Conversion --
4736 -----------------------------------
4737
4738 procedure Validate_Unchecked_Conversion
4739 (N : Node_Id;
4740 Act_Unit : Entity_Id)
4741 is
4742 Source : Entity_Id;
4743 Target : Entity_Id;
4744 Vnode : Node_Id;
4745
4746 begin
4747 -- Obtain source and target types. Note that we call Ancestor_Subtype
4748 -- here because the processing for generic instantiation always makes
4749 -- subtypes, and we want the original frozen actual types.
4750
4751 -- If we are dealing with private types, then do the check on their
4752 -- fully declared counterparts if the full declarations have been
4753 -- encountered (they don't have to be visible, but they must exist!)
4754
4755 Source := Ancestor_Subtype (Etype (First_Formal (Act_Unit)));
4756
4757 if Is_Private_Type (Source)
4758 and then Present (Underlying_Type (Source))
4759 then
4760 Source := Underlying_Type (Source);
4761 end if;
4762
4763 Target := Ancestor_Subtype (Etype (Act_Unit));
4764
fdd294d1 4765 -- If either type is generic, the instantiation happens within a generic
4766 -- unit, and there is nothing to check. The proper check
d6f39728 4767 -- will happen when the enclosing generic is instantiated.
4768
4769 if Is_Generic_Type (Source) or else Is_Generic_Type (Target) then
4770 return;
4771 end if;
4772
4773 if Is_Private_Type (Target)
4774 and then Present (Underlying_Type (Target))
4775 then
4776 Target := Underlying_Type (Target);
4777 end if;
4778
4779 -- Source may be unconstrained array, but not target
4780
4781 if Is_Array_Type (Target)
4782 and then not Is_Constrained (Target)
4783 then
4784 Error_Msg_N
4785 ("unchecked conversion to unconstrained array not allowed", N);
4786 return;
4787 end if;
4788
fbc67f84 4789 -- Warn if conversion between two different convention pointers
4790
4791 if Is_Access_Type (Target)
4792 and then Is_Access_Type (Source)
4793 and then Convention (Target) /= Convention (Source)
4794 and then Warn_On_Unchecked_Conversion
4795 then
fdd294d1 4796 -- Give warnings for subprogram pointers only on most targets. The
4797 -- exception is VMS, where data pointers can have different lengths
4798 -- depending on the pointer convention.
4799
4800 if Is_Access_Subprogram_Type (Target)
4801 or else Is_Access_Subprogram_Type (Source)
4802 or else OpenVMS_On_Target
4803 then
4804 Error_Msg_N
4805 ("?conversion between pointers with different conventions!", N);
4806 end if;
fbc67f84 4807 end if;
4808
3062c401 4809 -- Warn if one of the operands is Ada.Calendar.Time. Do not emit a
4810 -- warning when compiling GNAT-related sources.
4811
4812 if Warn_On_Unchecked_Conversion
4813 and then not In_Predefined_Unit (N)
4814 and then RTU_Loaded (Ada_Calendar)
4815 and then
4816 (Chars (Source) = Name_Time
4817 or else
4818 Chars (Target) = Name_Time)
4819 then
4820 -- If Ada.Calendar is loaded and the name of one of the operands is
4821 -- Time, there is a good chance that this is Ada.Calendar.Time.
4822
4823 declare
4824 Calendar_Time : constant Entity_Id :=
4825 Full_View (RTE (RO_CA_Time));
4826 begin
4827 pragma Assert (Present (Calendar_Time));
4828
4829 if Source = Calendar_Time
4830 or else Target = Calendar_Time
4831 then
4832 Error_Msg_N
4833 ("?representation of 'Time values may change between " &
4834 "'G'N'A'T versions", N);
4835 end if;
4836 end;
4837 end if;
4838
fdd294d1 4839 -- Make entry in unchecked conversion table for later processing by
4840 -- Validate_Unchecked_Conversions, which will check sizes and alignments
4841 -- (using values set by the back-end where possible). This is only done
4842 -- if the appropriate warning is active.
d6f39728 4843
9dfe12ae 4844 if Warn_On_Unchecked_Conversion then
4845 Unchecked_Conversions.Append
4846 (New_Val => UC_Entry'
299480f9 4847 (Eloc => Sloc (N),
9dfe12ae 4848 Source => Source,
4849 Target => Target));
4850
4851 -- If both sizes are known statically now, then back end annotation
4852 -- is not required to do a proper check but if either size is not
4853 -- known statically, then we need the annotation.
4854
4855 if Known_Static_RM_Size (Source)
4856 and then Known_Static_RM_Size (Target)
4857 then
4858 null;
4859 else
4860 Back_Annotate_Rep_Info := True;
4861 end if;
4862 end if;
d6f39728 4863
fdd294d1 4864 -- If unchecked conversion to access type, and access type is declared
4865 -- in the same unit as the unchecked conversion, then set the
4866 -- No_Strict_Aliasing flag (no strict aliasing is implicit in this
4867 -- situation).
28ed91d4 4868
4869 if Is_Access_Type (Target) and then
4870 In_Same_Source_Unit (Target, N)
4871 then
4872 Set_No_Strict_Aliasing (Implementation_Base_Type (Target));
4873 end if;
3d875462 4874
4875 -- Generate N_Validate_Unchecked_Conversion node for back end in
4876 -- case the back end needs to perform special validation checks.
4877
fdd294d1 4878 -- Shouldn't this be in Exp_Ch13, since the check only gets done
3d875462 4879 -- if we have full expansion and the back end is called ???
4880
4881 Vnode :=
4882 Make_Validate_Unchecked_Conversion (Sloc (N));
4883 Set_Source_Type (Vnode, Source);
4884 Set_Target_Type (Vnode, Target);
4885
fdd294d1 4886 -- If the unchecked conversion node is in a list, just insert before it.
4887 -- If not we have some strange case, not worth bothering about.
3d875462 4888
4889 if Is_List_Member (N) then
d6f39728 4890 Insert_After (N, Vnode);
4891 end if;
4892 end Validate_Unchecked_Conversion;
4893
4894 ------------------------------------
4895 -- Validate_Unchecked_Conversions --
4896 ------------------------------------
4897
4898 procedure Validate_Unchecked_Conversions is
4899 begin
4900 for N in Unchecked_Conversions.First .. Unchecked_Conversions.Last loop
4901 declare
4902 T : UC_Entry renames Unchecked_Conversions.Table (N);
4903
299480f9 4904 Eloc : constant Source_Ptr := T.Eloc;
4905 Source : constant Entity_Id := T.Source;
4906 Target : constant Entity_Id := T.Target;
d6f39728 4907
4908 Source_Siz : Uint;
4909 Target_Siz : Uint;
4910
4911 begin
fdd294d1 4912 -- This validation check, which warns if we have unequal sizes for
4913 -- unchecked conversion, and thus potentially implementation
d6f39728 4914 -- dependent semantics, is one of the few occasions on which we
fdd294d1 4915 -- use the official RM size instead of Esize. See description in
4916 -- Einfo "Handling of Type'Size Values" for details.
d6f39728 4917
f15731c4 4918 if Serious_Errors_Detected = 0
d6f39728 4919 and then Known_Static_RM_Size (Source)
4920 and then Known_Static_RM_Size (Target)
f25f4252 4921
4922 -- Don't do the check if warnings off for either type, note the
4923 -- deliberate use of OR here instead of OR ELSE to get the flag
4924 -- Warnings_Off_Used set for both types if appropriate.
4925
4926 and then not (Has_Warnings_Off (Source)
4927 or
4928 Has_Warnings_Off (Target))
d6f39728 4929 then
4930 Source_Siz := RM_Size (Source);
4931 Target_Siz := RM_Size (Target);
4932
4933 if Source_Siz /= Target_Siz then
299480f9 4934 Error_Msg
fbc67f84 4935 ("?types for unchecked conversion have different sizes!",
299480f9 4936 Eloc);
d6f39728 4937
4938 if All_Errors_Mode then
4939 Error_Msg_Name_1 := Chars (Source);
4940 Error_Msg_Uint_1 := Source_Siz;
4941 Error_Msg_Name_2 := Chars (Target);
4942 Error_Msg_Uint_2 := Target_Siz;
299480f9 4943 Error_Msg ("\size of % is ^, size of % is ^?", Eloc);
d6f39728 4944
4945 Error_Msg_Uint_1 := UI_Abs (Source_Siz - Target_Siz);
4946
4947 if Is_Discrete_Type (Source)
4948 and then Is_Discrete_Type (Target)
4949 then
4950 if Source_Siz > Target_Siz then
299480f9 4951 Error_Msg
fbc67f84 4952 ("\?^ high order bits of source will be ignored!",
299480f9 4953 Eloc);
d6f39728 4954
9dfe12ae 4955 elsif Is_Unsigned_Type (Source) then
299480f9 4956 Error_Msg
fbc67f84 4957 ("\?source will be extended with ^ high order " &
299480f9 4958 "zero bits?!", Eloc);
d6f39728 4959
4960 else
299480f9 4961 Error_Msg
fbc67f84 4962 ("\?source will be extended with ^ high order " &
4963 "sign bits!",
299480f9 4964 Eloc);
d6f39728 4965 end if;
4966
4967 elsif Source_Siz < Target_Siz then
4968 if Is_Discrete_Type (Target) then
4969 if Bytes_Big_Endian then
299480f9 4970 Error_Msg
fbc67f84 4971 ("\?target value will include ^ undefined " &
4972 "low order bits!",
299480f9 4973 Eloc);
d6f39728 4974 else
299480f9 4975 Error_Msg
fbc67f84 4976 ("\?target value will include ^ undefined " &
4977 "high order bits!",
299480f9 4978 Eloc);
d6f39728 4979 end if;
4980
4981 else
299480f9 4982 Error_Msg
fbc67f84 4983 ("\?^ trailing bits of target value will be " &
299480f9 4984 "undefined!", Eloc);
d6f39728 4985 end if;
4986
4987 else pragma Assert (Source_Siz > Target_Siz);
299480f9 4988 Error_Msg
fbc67f84 4989 ("\?^ trailing bits of source will be ignored!",
299480f9 4990 Eloc);
d6f39728 4991 end if;
4992 end if;
d6f39728 4993 end if;
4994 end if;
4995
4996 -- If both types are access types, we need to check the alignment.
4997 -- If the alignment of both is specified, we can do it here.
4998
f15731c4 4999 if Serious_Errors_Detected = 0
d6f39728 5000 and then Ekind (Source) in Access_Kind
5001 and then Ekind (Target) in Access_Kind
5002 and then Target_Strict_Alignment
5003 and then Present (Designated_Type (Source))
5004 and then Present (Designated_Type (Target))
5005 then
5006 declare
5007 D_Source : constant Entity_Id := Designated_Type (Source);
5008 D_Target : constant Entity_Id := Designated_Type (Target);
5009
5010 begin
5011 if Known_Alignment (D_Source)
5012 and then Known_Alignment (D_Target)
5013 then
5014 declare
5015 Source_Align : constant Uint := Alignment (D_Source);
5016 Target_Align : constant Uint := Alignment (D_Target);
5017
5018 begin
5019 if Source_Align < Target_Align
5020 and then not Is_Tagged_Type (D_Source)
f25f4252 5021
5022 -- Suppress warning if warnings suppressed on either
5023 -- type or either designated type. Note the use of
5024 -- OR here instead of OR ELSE. That is intentional,
5025 -- we would like to set flag Warnings_Off_Used in
5026 -- all types for which warnings are suppressed.
5027
5028 and then not (Has_Warnings_Off (D_Source)
5029 or
5030 Has_Warnings_Off (D_Target)
5031 or
5032 Has_Warnings_Off (Source)
5033 or
5034 Has_Warnings_Off (Target))
d6f39728 5035 then
d6f39728 5036 Error_Msg_Uint_1 := Target_Align;
5037 Error_Msg_Uint_2 := Source_Align;
299480f9 5038 Error_Msg_Node_1 := D_Target;
d6f39728 5039 Error_Msg_Node_2 := D_Source;
299480f9 5040 Error_Msg
fbc67f84 5041 ("?alignment of & (^) is stricter than " &
299480f9 5042 "alignment of & (^)!", Eloc);
f25f4252 5043 Error_Msg
5044 ("\?resulting access value may have invalid " &
5045 "alignment!", Eloc);
d6f39728 5046 end if;
5047 end;
5048 end if;
5049 end;
5050 end if;
5051 end;
5052 end loop;
5053 end Validate_Unchecked_Conversions;
5054
d6f39728 5055end Sem_Ch13;
Mirror of https://gcc.gnu.org/git/gcc.git