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2009-04-09 Richard Guenther <rguenther@suse.de>
[thirdparty/gcc.git] / gcc / ada / exp_attr.adb
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ee6ba406 1------------------------------------------------------------------------------
2-- --
3-- GNAT COMPILER COMPONENTS --
4-- --
5-- E X P _ A T T R --
6-- --
7-- B o d y --
8-- --
4c06b9d2 9-- Copyright (C) 1992-2008, Free Software Foundation, Inc. --
ee6ba406 10-- --
11-- GNAT is free software; you can redistribute it and/or modify it under --
12-- terms of the GNU General Public License as published by the Free Soft- --
13-- ware Foundation; either version 2, or (at your option) any later ver- --
14-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17-- for more details. You should have received a copy of the GNU General --
18-- Public License distributed with GNAT; see file COPYING. If not, write --
f27cea3a 19-- to the Free Software Foundation, 51 Franklin Street, Fifth Floor, --
20-- Boston, MA 02110-1301, USA. --
ee6ba406 21-- --
22-- GNAT was originally developed by the GNAT team at New York University. --
e78e8c8e 23-- Extensive contributions were provided by Ada Core Technologies Inc. --
ee6ba406 24-- --
25------------------------------------------------------------------------------
26
27with Atree; use Atree;
28with Checks; use Checks;
29with Einfo; use Einfo;
00f91aef 30with Elists; use Elists;
99f2248e 31with Exp_Atag; use Exp_Atag;
ee6ba406 32with Exp_Ch2; use Exp_Ch2;
d55c93e0 33with Exp_Ch3; use Exp_Ch3;
34with Exp_Ch6; use Exp_Ch6;
ee6ba406 35with Exp_Ch9; use Exp_Ch9;
5690e662 36with Exp_Dist; use Exp_Dist;
ee6ba406 37with Exp_Imgv; use Exp_Imgv;
38with Exp_Pakd; use Exp_Pakd;
39with Exp_Strm; use Exp_Strm;
40with Exp_Tss; use Exp_Tss;
41with Exp_Util; use Exp_Util;
6e62b6c3 42with Exp_VFpt; use Exp_VFpt;
d55c93e0 43with Fname; use Fname;
db14252c 44with Freeze; use Freeze;
ee6ba406 45with Gnatvsn; use Gnatvsn;
db14252c 46with Itypes; use Itypes;
ee6ba406 47with Lib; use Lib;
48with Namet; use Namet;
49with Nmake; use Nmake;
50with Nlists; use Nlists;
51with Opt; use Opt;
52with Restrict; use Restrict;
1e16c51c 53with Rident; use Rident;
ee6ba406 54with Rtsfind; use Rtsfind;
55with Sem; use Sem;
d60c9ff7 56with Sem_Aux; use Sem_Aux;
4c06b9d2 57with Sem_Ch6; use Sem_Ch6;
ee6ba406 58with Sem_Ch7; use Sem_Ch7;
59with Sem_Ch8; use Sem_Ch8;
ee6ba406 60with Sem_Eval; use Sem_Eval;
61with Sem_Res; use Sem_Res;
62with Sem_Util; use Sem_Util;
63with Sinfo; use Sinfo;
64with Snames; use Snames;
65with Stand; use Stand;
66with Stringt; use Stringt;
83aa52b6 67with Targparm; use Targparm;
ee6ba406 68with Tbuild; use Tbuild;
69with Ttypes; use Ttypes;
70with Uintp; use Uintp;
71with Uname; use Uname;
72with Validsw; use Validsw;
73
74package body Exp_Attr is
75
76 -----------------------
77 -- Local Subprograms --
78 -----------------------
79
80 procedure Compile_Stream_Body_In_Scope
81 (N : Node_Id;
82 Decl : Node_Id;
83 Arr : Entity_Id;
84 Check : Boolean);
85 -- The body for a stream subprogram may be generated outside of the scope
86 -- of the type. If the type is fully private, it may depend on the full
87 -- view of other types (e.g. indices) that are currently private as well.
88 -- We install the declarations of the package in which the type is declared
89 -- before compiling the body in what is its proper environment. The Check
90 -- parameter indicates if checks are to be suppressed for the stream body.
91 -- We suppress checks for array/record reads, since the rule is that these
92 -- are like assignments, out of range values due to uninitialized storage,
93 -- or other invalid values do NOT cause a Constraint_Error to be raised.
94
7f8eb6ed 95 procedure Expand_Access_To_Protected_Op
96 (N : Node_Id;
97 Pref : Node_Id;
98 Typ : Entity_Id);
99
100 -- An attribute reference to a protected subprogram is transformed into
101 -- a pair of pointers: one to the object, and one to the operations.
102 -- This expansion is performed for 'Access and for 'Unrestricted_Access.
103
ee6ba406 104 procedure Expand_Fpt_Attribute
9dfe12ae 105 (N : Node_Id;
1550b445 106 Pkg : RE_Id;
9dfe12ae 107 Nam : Name_Id;
ee6ba406 108 Args : List_Id);
109 -- This procedure expands a call to a floating-point attribute function.
110 -- N is the attribute reference node, and Args is a list of arguments to
1550b445 111 -- be passed to the function call. Pkg identifies the package containing
112 -- the appropriate instantiation of System.Fat_Gen. Float arguments in Args
113 -- have already been converted to the floating-point type for which Pkg was
114 -- instantiated. The Nam argument is the relevant attribute processing
115 -- routine to be called. This is the same as the attribute name, except in
116 -- the Unaligned_Valid case.
ee6ba406 117
118 procedure Expand_Fpt_Attribute_R (N : Node_Id);
119 -- This procedure expands a call to a floating-point attribute function
9dfe12ae 120 -- that takes a single floating-point argument. The function to be called
121 -- is always the same as the attribute name.
ee6ba406 122
123 procedure Expand_Fpt_Attribute_RI (N : Node_Id);
124 -- This procedure expands a call to a floating-point attribute function
9dfe12ae 125 -- that takes one floating-point argument and one integer argument. The
126 -- function to be called is always the same as the attribute name.
ee6ba406 127
128 procedure Expand_Fpt_Attribute_RR (N : Node_Id);
129 -- This procedure expands a call to a floating-point attribute function
9dfe12ae 130 -- that takes two floating-point arguments. The function to be called
131 -- is always the same as the attribute name.
ee6ba406 132
133 procedure Expand_Pred_Succ (N : Node_Id);
134 -- Handles expansion of Pred or Succ attributes for case of non-real
135 -- operand with overflow checking required.
136
137 function Get_Index_Subtype (N : Node_Id) return Entity_Id;
f0bf2ff3 138 -- Used for Last, Last, and Length, when the prefix is an array type.
ee6ba406 139 -- Obtains the corresponding index subtype.
140
1550b445 141 procedure Find_Fat_Info
142 (T : Entity_Id;
143 Fat_Type : out Entity_Id;
144 Fat_Pkg : out RE_Id);
145 -- Given a floating-point type T, identifies the package containing the
146 -- attributes for this type (returned in Fat_Pkg), and the corresponding
147 -- type for which this package was instantiated from Fat_Gen. Error if T
148 -- is not a floating-point type.
149
9dfe12ae 150 function Find_Stream_Subprogram
151 (Typ : Entity_Id;
152 Nam : TSS_Name_Type) return Entity_Id;
153 -- Returns the stream-oriented subprogram attribute for Typ. For tagged
154 -- types, the corresponding primitive operation is looked up, else the
155 -- appropriate TSS from the type itself, or from its closest ancestor
156 -- defining it, is returned. In both cases, inheritance of representation
157 -- aspects is thus taken into account.
ee6ba406 158
5245b786 159 function Get_Stream_Convert_Pragma (T : Entity_Id) return Node_Id;
160 -- Given a type, find a corresponding stream convert pragma that applies to
161 -- the implementation base type of this type (Typ). If found, return the
162 -- pragma node, otherwise return Empty if no pragma is found.
163
ee6ba406 164 function Is_Constrained_Packed_Array (Typ : Entity_Id) return Boolean;
165 -- Utility for array attributes, returns true on packed constrained
166 -- arrays, and on access to same.
167
99f2248e 168 function Is_Inline_Floating_Point_Attribute (N : Node_Id) return Boolean;
169 -- Returns true iff the given node refers to an attribute call that
170 -- can be expanded directly by the back end and does not need front end
171 -- expansion. Typically used for rounding and truncation attributes that
172 -- appear directly inside a conversion to integer.
173
ee6ba406 174 ----------------------------------
175 -- Compile_Stream_Body_In_Scope --
176 ----------------------------------
177
178 procedure Compile_Stream_Body_In_Scope
179 (N : Node_Id;
180 Decl : Node_Id;
181 Arr : Entity_Id;
182 Check : Boolean)
183 is
184 Installed : Boolean := False;
185 Scop : constant Entity_Id := Scope (Arr);
186 Curr : constant Entity_Id := Current_Scope;
187
188 begin
189 if Is_Hidden (Arr)
190 and then not In_Open_Scopes (Scop)
191 and then Ekind (Scop) = E_Package
192 then
83aa52b6 193 Push_Scope (Scop);
ee6ba406 194 Install_Visible_Declarations (Scop);
195 Install_Private_Declarations (Scop);
196 Installed := True;
197
198 -- The entities in the package are now visible, but the generated
199 -- stream entity must appear in the current scope (usually an
200 -- enclosing stream function) so that itypes all have their proper
201 -- scopes.
202
83aa52b6 203 Push_Scope (Curr);
ee6ba406 204 end if;
205
206 if Check then
207 Insert_Action (N, Decl);
208 else
1550b445 209 Insert_Action (N, Decl, Suppress => All_Checks);
ee6ba406 210 end if;
211
212 if Installed then
213
214 -- Remove extra copy of current scope, and package itself
215
216 Pop_Scope;
217 End_Package_Scope (Scop);
218 end if;
219 end Compile_Stream_Body_In_Scope;
220
7f8eb6ed 221 -----------------------------------
222 -- Expand_Access_To_Protected_Op --
223 -----------------------------------
224
225 procedure Expand_Access_To_Protected_Op
226 (N : Node_Id;
227 Pref : Node_Id;
228 Typ : Entity_Id)
229 is
230 -- The value of the attribute_reference is a record containing two
231 -- fields: an access to the protected object, and an access to the
232 -- subprogram itself. The prefix is a selected component.
233
234 Loc : constant Source_Ptr := Sloc (N);
235 Agg : Node_Id;
236 Btyp : constant Entity_Id := Base_Type (Typ);
237 Sub : Entity_Id;
238 E_T : constant Entity_Id := Equivalent_Type (Btyp);
239 Acc : constant Entity_Id :=
240 Etype (Next_Component (First_Component (E_T)));
241 Obj_Ref : Node_Id;
242 Curr : Entity_Id;
243
244 function May_Be_External_Call return Boolean;
245 -- If the 'Access is to a local operation, but appears in a context
246 -- where it may lead to a call from outside the object, we must treat
247 -- this as an external call. Clearly we cannot tell without full
248 -- flow analysis, and a subsequent call that uses this 'Access may
249 -- lead to a bounded error (trying to seize locks twice, e.g.). For
250 -- now we treat 'Access as a potential external call if it is an actual
251 -- in a call to an outside subprogram.
252
253 --------------------------
254 -- May_Be_External_Call --
255 --------------------------
256
257 function May_Be_External_Call return Boolean is
258 Subp : Entity_Id;
d55c93e0 259 Par : Node_Id := Parent (N);
260
7f8eb6ed 261 begin
d55c93e0 262 -- Account for the case where the Access attribute is part of a
263 -- named parameter association.
264
265 if Nkind (Par) = N_Parameter_Association then
266 Par := Parent (Par);
267 end if;
268
269 if Nkind_In (Par, N_Procedure_Call_Statement, N_Function_Call)
270 and then Is_Entity_Name (Name (Par))
7f8eb6ed 271 then
d55c93e0 272 Subp := Entity (Name (Par));
7f8eb6ed 273 return not In_Open_Scopes (Scope (Subp));
274 else
275 return False;
276 end if;
277 end May_Be_External_Call;
278
279 -- Start of processing for Expand_Access_To_Protected_Op
280
281 begin
282 -- Within the body of the protected type, the prefix
283 -- designates a local operation, and the object is the first
284 -- parameter of the corresponding protected body of the
285 -- current enclosing operation.
286
287 if Is_Entity_Name (Pref) then
7f8eb6ed 288 if May_Be_External_Call then
289 Sub :=
290 New_Occurrence_Of
291 (External_Subprogram (Entity (Pref)), Loc);
292 else
293 Sub :=
294 New_Occurrence_Of
295 (Protected_Body_Subprogram (Entity (Pref)), Loc);
296 end if;
297
d55c93e0 298 -- Don't traverse the scopes when the attribute occurs within an init
299 -- proc, because we directly use the _init formal of the init proc in
300 -- that case.
301
7f8eb6ed 302 Curr := Current_Scope;
d55c93e0 303 if not Is_Init_Proc (Curr) then
304 pragma Assert (In_Open_Scopes (Scope (Entity (Pref))));
305
306 while Scope (Curr) /= Scope (Entity (Pref)) loop
307 Curr := Scope (Curr);
308 end loop;
309 end if;
7f8eb6ed 310
311 -- In case of protected entries the first formal of its Protected_
312 -- Body_Subprogram is the address of the object.
313
314 if Ekind (Curr) = E_Entry then
315 Obj_Ref :=
316 New_Occurrence_Of
317 (First_Formal
318 (Protected_Body_Subprogram (Curr)), Loc);
319
d55c93e0 320 -- If the current scope is an init proc, then use the address of the
321 -- _init formal as the object reference.
322
323 elsif Is_Init_Proc (Curr) then
324 Obj_Ref :=
325 Make_Attribute_Reference (Loc,
326 Prefix => New_Occurrence_Of (First_Formal (Curr), Loc),
327 Attribute_Name => Name_Address);
328
7f8eb6ed 329 -- In case of protected subprograms the first formal of its
330 -- Protected_Body_Subprogram is the object and we get its address.
331
332 else
333 Obj_Ref :=
334 Make_Attribute_Reference (Loc,
335 Prefix =>
336 New_Occurrence_Of
337 (First_Formal
338 (Protected_Body_Subprogram (Curr)), Loc),
339 Attribute_Name => Name_Address);
340 end if;
341
342 -- Case where the prefix is not an entity name. Find the
343 -- version of the protected operation to be called from
344 -- outside the protected object.
345
346 else
347 Sub :=
348 New_Occurrence_Of
349 (External_Subprogram
350 (Entity (Selector_Name (Pref))), Loc);
351
352 Obj_Ref :=
353 Make_Attribute_Reference (Loc,
354 Prefix => Relocate_Node (Prefix (Pref)),
355 Attribute_Name => Name_Address);
356 end if;
357
358 Agg :=
359 Make_Aggregate (Loc,
360 Expressions =>
361 New_List (
362 Obj_Ref,
363 Unchecked_Convert_To (Acc,
364 Make_Attribute_Reference (Loc,
365 Prefix => Sub,
366 Attribute_Name => Name_Address))));
367
368 Rewrite (N, Agg);
369
370 Analyze_And_Resolve (N, E_T);
371
372 -- For subsequent analysis, the node must retain its type.
373 -- The backend will replace it with the equivalent type where
374 -- needed.
375
376 Set_Etype (N, Typ);
377 end Expand_Access_To_Protected_Op;
378
ee6ba406 379 --------------------------
380 -- Expand_Fpt_Attribute --
381 --------------------------
382
383 procedure Expand_Fpt_Attribute
384 (N : Node_Id;
1550b445 385 Pkg : RE_Id;
9dfe12ae 386 Nam : Name_Id;
ee6ba406 387 Args : List_Id)
388 is
389 Loc : constant Source_Ptr := Sloc (N);
390 Typ : constant Entity_Id := Etype (N);
ee6ba406 391 Fnm : Node_Id;
392
393 begin
1550b445 394 -- The function name is the selected component Attr_xxx.yyy where
395 -- Attr_xxx is the package name, and yyy is the argument Nam.
ee6ba406 396
397 -- Note: it would be more usual to have separate RE entries for each
398 -- of the entities in the Fat packages, but first they have identical
399 -- names (so we would have to have lots of renaming declarations to
400 -- meet the normal RE rule of separate names for all runtime entities),
401 -- and second there would be an awful lot of them!
402
ee6ba406 403 Fnm :=
404 Make_Selected_Component (Loc,
405 Prefix => New_Reference_To (RTE (Pkg), Loc),
9dfe12ae 406 Selector_Name => Make_Identifier (Loc, Nam));
ee6ba406 407
408 -- The generated call is given the provided set of parameters, and then
409 -- wrapped in a conversion which converts the result to the target type
5245b786 410 -- We use the base type as the target because a range check may be
411 -- required.
ee6ba406 412
413 Rewrite (N,
5245b786 414 Unchecked_Convert_To (Base_Type (Etype (N)),
ee6ba406 415 Make_Function_Call (Loc,
1550b445 416 Name => Fnm,
ee6ba406 417 Parameter_Associations => Args)));
418
419 Analyze_And_Resolve (N, Typ);
ee6ba406 420 end Expand_Fpt_Attribute;
421
422 ----------------------------
423 -- Expand_Fpt_Attribute_R --
424 ----------------------------
425
426 -- The single argument is converted to its root type to call the
427 -- appropriate runtime function, with the actual call being built
428 -- by Expand_Fpt_Attribute
429
430 procedure Expand_Fpt_Attribute_R (N : Node_Id) is
431 E1 : constant Node_Id := First (Expressions (N));
1550b445 432 Ftp : Entity_Id;
433 Pkg : RE_Id;
ee6ba406 434 begin
1550b445 435 Find_Fat_Info (Etype (E1), Ftp, Pkg);
9dfe12ae 436 Expand_Fpt_Attribute
1550b445 437 (N, Pkg, Attribute_Name (N),
438 New_List (Unchecked_Convert_To (Ftp, Relocate_Node (E1))));
ee6ba406 439 end Expand_Fpt_Attribute_R;
440
441 -----------------------------
442 -- Expand_Fpt_Attribute_RI --
443 -----------------------------
444
445 -- The first argument is converted to its root type and the second
446 -- argument is converted to standard long long integer to call the
447 -- appropriate runtime function, with the actual call being built
448 -- by Expand_Fpt_Attribute
449
450 procedure Expand_Fpt_Attribute_RI (N : Node_Id) is
451 E1 : constant Node_Id := First (Expressions (N));
1550b445 452 Ftp : Entity_Id;
453 Pkg : RE_Id;
ee6ba406 454 E2 : constant Node_Id := Next (E1);
ee6ba406 455 begin
1550b445 456 Find_Fat_Info (Etype (E1), Ftp, Pkg);
9dfe12ae 457 Expand_Fpt_Attribute
1550b445 458 (N, Pkg, Attribute_Name (N),
9dfe12ae 459 New_List (
1550b445 460 Unchecked_Convert_To (Ftp, Relocate_Node (E1)),
9dfe12ae 461 Unchecked_Convert_To (Standard_Integer, Relocate_Node (E2))));
ee6ba406 462 end Expand_Fpt_Attribute_RI;
463
464 -----------------------------
465 -- Expand_Fpt_Attribute_RR --
466 -----------------------------
467
99f2248e 468 -- The two arguments are converted to their root types to call the
ee6ba406 469 -- appropriate runtime function, with the actual call being built
470 -- by Expand_Fpt_Attribute
471
472 procedure Expand_Fpt_Attribute_RR (N : Node_Id) is
473 E1 : constant Node_Id := First (Expressions (N));
1550b445 474 Ftp : Entity_Id;
475 Pkg : RE_Id;
ee6ba406 476 E2 : constant Node_Id := Next (E1);
ee6ba406 477 begin
1550b445 478 Find_Fat_Info (Etype (E1), Ftp, Pkg);
9dfe12ae 479 Expand_Fpt_Attribute
1550b445 480 (N, Pkg, Attribute_Name (N),
9dfe12ae 481 New_List (
1550b445 482 Unchecked_Convert_To (Ftp, Relocate_Node (E1)),
483 Unchecked_Convert_To (Ftp, Relocate_Node (E2))));
ee6ba406 484 end Expand_Fpt_Attribute_RR;
485
486 ----------------------------------
487 -- Expand_N_Attribute_Reference --
488 ----------------------------------
489
490 procedure Expand_N_Attribute_Reference (N : Node_Id) is
491 Loc : constant Source_Ptr := Sloc (N);
492 Typ : constant Entity_Id := Etype (N);
493 Btyp : constant Entity_Id := Base_Type (Typ);
494 Pref : constant Node_Id := Prefix (N);
d55c93e0 495 Ptyp : constant Entity_Id := Etype (Pref);
ee6ba406 496 Exprs : constant List_Id := Expressions (N);
497 Id : constant Attribute_Id := Get_Attribute_Id (Attribute_Name (N));
498
499 procedure Rewrite_Stream_Proc_Call (Pname : Entity_Id);
500 -- Rewrites a stream attribute for Read, Write or Output with the
501 -- procedure call. Pname is the entity for the procedure to call.
502
503 ------------------------------
504 -- Rewrite_Stream_Proc_Call --
505 ------------------------------
506
507 procedure Rewrite_Stream_Proc_Call (Pname : Entity_Id) is
508 Item : constant Node_Id := Next (First (Exprs));
9dfe12ae 509 Formal : constant Entity_Id := Next_Formal (First_Formal (Pname));
510 Formal_Typ : constant Entity_Id := Etype (Formal);
511 Is_Written : constant Boolean := (Ekind (Formal) /= E_In_Parameter);
ee6ba406 512
513 begin
9dfe12ae 514 -- The expansion depends on Item, the second actual, which is
515 -- the object being streamed in or out.
516
517 -- If the item is a component of a packed array type, and
518 -- a conversion is needed on exit, we introduce a temporary to
519 -- hold the value, because otherwise the packed reference will
520 -- not be properly expanded.
521
522 if Nkind (Item) = N_Indexed_Component
523 and then Is_Packed (Base_Type (Etype (Prefix (Item))))
524 and then Base_Type (Etype (Item)) /= Base_Type (Formal_Typ)
525 and then Is_Written
526 then
527 declare
528 Temp : constant Entity_Id :=
529 Make_Defining_Identifier
530 (Loc, New_Internal_Name ('V'));
531 Decl : Node_Id;
532 Assn : Node_Id;
533
534 begin
535 Decl :=
536 Make_Object_Declaration (Loc,
537 Defining_Identifier => Temp,
538 Object_Definition =>
539 New_Occurrence_Of (Formal_Typ, Loc));
540 Set_Etype (Temp, Formal_Typ);
541
542 Assn :=
543 Make_Assignment_Statement (Loc,
544 Name => New_Copy_Tree (Item),
545 Expression =>
546 Unchecked_Convert_To
547 (Etype (Item), New_Occurrence_Of (Temp, Loc)));
548
549 Rewrite (Item, New_Occurrence_Of (Temp, Loc));
550 Insert_Actions (N,
551 New_List (
552 Decl,
553 Make_Procedure_Call_Statement (Loc,
554 Name => New_Occurrence_Of (Pname, Loc),
555 Parameter_Associations => Exprs),
556 Assn));
557
558 Rewrite (N, Make_Null_Statement (Loc));
559 return;
560 end;
561 end if;
ee6ba406 562
563 -- For the class-wide dispatching cases, and for cases in which
564 -- the base type of the second argument matches the base type of
9dfe12ae 565 -- the corresponding formal parameter (that is to say the stream
566 -- operation is not inherited), we are all set, and can use the
567 -- argument unchanged.
ee6ba406 568
569 -- For all other cases we do an unchecked conversion of the second
570 -- parameter to the type of the formal of the procedure we are
571 -- calling. This deals with the private type cases, and with going
572 -- to the root type as required in elementary type case.
573
574 if not Is_Class_Wide_Type (Entity (Pref))
9dfe12ae 575 and then not Is_Class_Wide_Type (Etype (Item))
ee6ba406 576 and then Base_Type (Etype (Item)) /= Base_Type (Formal_Typ)
577 then
578 Rewrite (Item,
579 Unchecked_Convert_To (Formal_Typ, Relocate_Node (Item)));
580
581 -- For untagged derived types set Assignment_OK, to prevent
582 -- copies from being created when the unchecked conversion
583 -- is expanded (which would happen in Remove_Side_Effects
584 -- if Expand_N_Unchecked_Conversion were allowed to call
585 -- Force_Evaluation). The copy could violate Ada semantics
586 -- in cases such as an actual that is an out parameter.
587 -- Note that this approach is also used in exp_ch7 for calls
588 -- to controlled type operations to prevent problems with
589 -- actuals wrapped in unchecked conversions.
590
591 if Is_Untagged_Derivation (Etype (Expression (Item))) then
592 Set_Assignment_OK (Item);
593 end if;
594 end if;
595
596 -- And now rewrite the call
597
598 Rewrite (N,
599 Make_Procedure_Call_Statement (Loc,
600 Name => New_Occurrence_Of (Pname, Loc),
601 Parameter_Associations => Exprs));
602
603 Analyze (N);
604 end Rewrite_Stream_Proc_Call;
605
606 -- Start of processing for Expand_N_Attribute_Reference
607
608 begin
7189d17f 609 -- Do required validity checking, if enabled. Do not apply check to
610 -- output parameters of an Asm instruction, since the value of this
372ac9de 611 -- is not set till after the attribute has been elaborated, and do
612 -- not apply the check to the arguments of a 'Read or 'Input attribute
613 -- reference since the scalar argument is an OUT scalar.
ee6ba406 614
7189d17f 615 if Validity_Checks_On and then Validity_Check_Operands
616 and then Id /= Attribute_Asm_Output
372ac9de 617 and then Id /= Attribute_Read
618 and then Id /= Attribute_Input
7189d17f 619 then
ee6ba406 620 declare
621 Expr : Node_Id;
ee6ba406 622 begin
623 Expr := First (Expressions (N));
624 while Present (Expr) loop
625 Ensure_Valid (Expr);
626 Next (Expr);
627 end loop;
628 end;
629 end if;
630
d55c93e0 631 -- Ada 2005 (AI-318-02): If attribute prefix is a call to a build-in-
632 -- place function, then a temporary return object needs to be created
633 -- and access to it must be passed to the function. Currently we limit
634 -- such functions to those with inherently limited result subtypes, but
635 -- eventually we plan to expand the functions that are treated as
636 -- build-in-place to include other composite result types.
637
638 if Ada_Version >= Ada_05
639 and then Is_Build_In_Place_Function_Call (Pref)
640 then
641 Make_Build_In_Place_Call_In_Anonymous_Context (Pref);
642 end if;
643
98d58e33 644 -- If prefix is a protected type name, this is a reference to
645 -- the current instance of the type.
646
647 if Is_Protected_Self_Reference (Pref) then
648 Rewrite (Pref, Concurrent_Ref (Pref));
649 Analyze (Pref);
650 end if;
651
ee6ba406 652 -- Remaining processing depends on specific attribute
653
654 case Id is
655
656 ------------
657 -- Access --
658 ------------
659
f947f061 660 when Attribute_Access |
661 Attribute_Unchecked_Access |
662 Attribute_Unrestricted_Access =>
ee6ba406 663
5e82d8fe 664 Access_Cases : declare
5e82d8fe 665 Ref_Object : constant Node_Id := Get_Referenced_Object (Pref);
d251c56f 666 Btyp_DDT : Entity_Id;
ee6ba406 667
4094dca5 668 function Enclosing_Object (N : Node_Id) return Node_Id;
669 -- If N denotes a compound name (selected component, indexed
670 -- component, or slice), returns the name of the outermost
671 -- such enclosing object. Otherwise returns N. If the object
672 -- is a renaming, then the renamed object is returned.
673
674 ----------------------
675 -- Enclosing_Object --
676 ----------------------
677
678 function Enclosing_Object (N : Node_Id) return Node_Id is
679 Obj_Name : Node_Id;
680
681 begin
682 Obj_Name := N;
683 while Nkind_In (Obj_Name, N_Selected_Component,
684 N_Indexed_Component,
685 N_Slice)
686 loop
687 Obj_Name := Prefix (Obj_Name);
688 end loop;
689
690 return Get_Referenced_Object (Obj_Name);
691 end Enclosing_Object;
692
693 -- Local declarations
694
695 Enc_Object : constant Node_Id := Enclosing_Object (Ref_Object);
696
697 -- Start of processing for Access_Cases
698
5e82d8fe 699 begin
d251c56f 700 Btyp_DDT := Designated_Type (Btyp);
701
702 -- Handle designated types that come from the limited view
703
704 if Ekind (Btyp_DDT) = E_Incomplete_Type
705 and then From_With_Type (Btyp_DDT)
706 and then Present (Non_Limited_View (Btyp_DDT))
707 then
708 Btyp_DDT := Non_Limited_View (Btyp_DDT);
709
710 elsif Is_Class_Wide_Type (Btyp_DDT)
711 and then Ekind (Etype (Btyp_DDT)) = E_Incomplete_Type
712 and then From_With_Type (Etype (Btyp_DDT))
713 and then Present (Non_Limited_View (Etype (Btyp_DDT)))
714 and then Present (Class_Wide_Type
715 (Non_Limited_View (Etype (Btyp_DDT))))
716 then
717 Btyp_DDT :=
718 Class_Wide_Type (Non_Limited_View (Etype (Btyp_DDT)));
719 end if;
720
4c06b9d2 721 -- In order to improve the text of error messages, the designated
722 -- type of access-to-subprogram itypes is set by the semantics as
723 -- the associated subprogram entity (see sem_attr). Now we replace
724 -- such node with the proper E_Subprogram_Type itype.
725
726 if Id = Attribute_Unrestricted_Access
727 and then Is_Subprogram (Directly_Designated_Type (Typ))
728 then
d55c93e0 729 -- The following conditions ensure that this special management
4c06b9d2 730 -- is done only for "Address!(Prim'Unrestricted_Access)" nodes.
731 -- At this stage other cases in which the designated type is
732 -- still a subprogram (instead of an E_Subprogram_Type) are
526aedbb 733 -- wrong because the semantics must have overridden the type of
4c06b9d2 734 -- the node with the type imposed by the context.
735
d55c93e0 736 if Nkind (Parent (N)) = N_Unchecked_Type_Conversion
737 and then Etype (Parent (N)) = RTE (RE_Prim_Ptr)
738 then
739 Set_Etype (N, RTE (RE_Prim_Ptr));
4c06b9d2 740
d55c93e0 741 else
742 declare
743 Subp : constant Entity_Id :=
744 Directly_Designated_Type (Typ);
745 Etyp : Entity_Id;
746 Extra : Entity_Id := Empty;
747 New_Formal : Entity_Id;
748 Old_Formal : Entity_Id := First_Formal (Subp);
749 Subp_Typ : Entity_Id;
4c06b9d2 750
d55c93e0 751 begin
752 Subp_Typ := Create_Itype (E_Subprogram_Type, N);
753 Set_Etype (Subp_Typ, Etype (Subp));
754 Set_Returns_By_Ref (Subp_Typ, Returns_By_Ref (Subp));
4c06b9d2 755
d55c93e0 756 if Present (Old_Formal) then
757 New_Formal := New_Copy (Old_Formal);
758 Set_First_Entity (Subp_Typ, New_Formal);
4c06b9d2 759
d55c93e0 760 loop
761 Set_Scope (New_Formal, Subp_Typ);
762 Etyp := Etype (New_Formal);
4c06b9d2 763
d55c93e0 764 -- Handle itypes. There is no need to duplicate
765 -- here the itypes associated with record types
766 -- (i.e the implicit full view of private types).
4c06b9d2 767
d55c93e0 768 if Is_Itype (Etyp)
769 and then Ekind (Base_Type (Etyp)) /= E_Record_Type
4c06b9d2 770 then
d55c93e0 771 Extra := New_Copy (Etyp);
772 Set_Parent (Extra, New_Formal);
773 Set_Etype (New_Formal, Extra);
774 Set_Scope (Extra, Subp_Typ);
4c06b9d2 775 end if;
776
d55c93e0 777 Extra := New_Formal;
778 Next_Formal (Old_Formal);
779 exit when No (Old_Formal);
4c06b9d2 780
d55c93e0 781 Set_Next_Entity (New_Formal,
782 New_Copy (Old_Formal));
783 Next_Entity (New_Formal);
784 end loop;
4c06b9d2 785
d55c93e0 786 Set_Next_Entity (New_Formal, Empty);
787 Set_Last_Entity (Subp_Typ, Extra);
788 end if;
4c06b9d2 789
d55c93e0 790 -- Now that the explicit formals have been duplicated,
791 -- any extra formals needed by the subprogram must be
792 -- created.
4c06b9d2 793
d55c93e0 794 if Present (Extra) then
795 Set_Extra_Formal (Extra, Empty);
796 end if;
4c06b9d2 797
d55c93e0 798 Create_Extra_Formals (Subp_Typ);
799 Set_Directly_Designated_Type (Typ, Subp_Typ);
800 end;
801 end if;
4c06b9d2 802 end if;
803
5e82d8fe 804 if Is_Access_Protected_Subprogram_Type (Btyp) then
805 Expand_Access_To_Protected_Op (N, Pref, Typ);
806
807 -- If prefix is a type name, this is a reference to the current
808 -- instance of the type, within its initialization procedure.
809
810 elsif Is_Entity_Name (Pref)
811 and then Is_Type (Entity (Pref))
812 then
813 declare
814 Par : Node_Id;
815 Formal : Entity_Id;
816
817 begin
818 -- If the current instance name denotes a task type, then
819 -- the access attribute is rewritten to be the name of the
820 -- "_task" parameter associated with the task type's task
821 -- procedure. An unchecked conversion is applied to ensure
822 -- a type match in cases of expander-generated calls (e.g.
823 -- init procs).
824
825 if Is_Task_Type (Entity (Pref)) then
826 Formal :=
827 First_Entity (Get_Task_Body_Procedure (Entity (Pref)));
828 while Present (Formal) loop
829 exit when Chars (Formal) = Name_uTask;
830 Next_Entity (Formal);
831 end loop;
832
833 pragma Assert (Present (Formal));
f947f061 834
5e82d8fe 835 Rewrite (N,
836 Unchecked_Convert_To (Typ,
837 New_Occurrence_Of (Formal, Loc)));
838 Set_Etype (N, Typ);
f947f061 839
5e82d8fe 840 -- The expression must appear in a default expression,
841 -- (which in the initialization procedure is the
842 -- right-hand side of an assignment), and not in a
843 -- discriminant constraint.
f947f061 844
5e82d8fe 845 else
846 Par := Parent (N);
847 while Present (Par) loop
848 exit when Nkind (Par) = N_Assignment_Statement;
f947f061 849
5e82d8fe 850 if Nkind (Par) = N_Component_Declaration then
851 return;
852 end if;
f947f061 853
5e82d8fe 854 Par := Parent (Par);
855 end loop;
f947f061 856
5e82d8fe 857 if Present (Par) then
858 Rewrite (N,
859 Make_Attribute_Reference (Loc,
860 Prefix => Make_Identifier (Loc, Name_uInit),
861 Attribute_Name => Attribute_Name (N)));
f947f061 862
5e82d8fe 863 Analyze_And_Resolve (N, Typ);
864 end if;
f947f061 865 end if;
5e82d8fe 866 end;
867
868 -- If the prefix of an Access attribute is a dereference of an
4094dca5 869 -- access parameter (or a renaming of such a dereference, or a
870 -- subcomponent of such a dereference) and the context is a
80e22f63 871 -- general access type (including the type of an object or
872 -- component with an access_definition, but not the anonymous
873 -- type of an access parameter or access discriminant), then
4094dca5 874 -- apply an accessibility check to the access parameter. We used
875 -- to rewrite the access parameter as a type conversion, but that
876 -- could only be done if the immediate prefix of the Access
877 -- attribute was the dereference, and didn't handle cases where
878 -- the attribute is applied to a subcomponent of the dereference,
879 -- since there's generally no available, appropriate access type
55dc6dc2 880 -- to convert to in that case. The attribute is passed as the
881 -- point to insert the check, because the access parameter may
882 -- come from a renaming, possibly in a different scope, and the
883 -- check must be associated with the attribute itself.
4094dca5 884
885 elsif Id = Attribute_Access
886 and then Nkind (Enc_Object) = N_Explicit_Dereference
887 and then Is_Entity_Name (Prefix (Enc_Object))
80e22f63 888 and then (Ekind (Btyp) = E_General_Access_Type
889 or else Is_Local_Anonymous_Access (Btyp))
4094dca5 890 and then Ekind (Entity (Prefix (Enc_Object))) in Formal_Kind
891 and then Ekind (Etype (Entity (Prefix (Enc_Object))))
5e82d8fe 892 = E_Anonymous_Access_Type
893 and then Present (Extra_Accessibility
4094dca5 894 (Entity (Prefix (Enc_Object))))
5e82d8fe 895 then
55dc6dc2 896 Apply_Accessibility_Check (Prefix (Enc_Object), Typ, N);
5e82d8fe 897
898 -- Ada 2005 (AI-251): If the designated type is an interface we
899 -- add an implicit conversion to force the displacement of the
900 -- pointer to reference the secondary dispatch table.
901
902 elsif Is_Interface (Btyp_DDT)
903 and then (Comes_From_Source (N)
904 or else Comes_From_Source (Ref_Object)
905 or else (Nkind (Ref_Object) in N_Has_Chars
906 and then Chars (Ref_Object) = Name_uInit))
907 then
908 if Nkind (Ref_Object) /= N_Explicit_Dereference then
909
910 -- No implicit conversion required if types match
911
912 if Btyp_DDT /= Etype (Ref_Object) then
913 Rewrite (Prefix (N),
d251c56f 914 Convert_To (Btyp_DDT,
5e82d8fe 915 New_Copy_Tree (Prefix (N))));
916
d251c56f 917 Analyze_And_Resolve (Prefix (N), Btyp_DDT);
ee6ba406 918 end if;
aad6babd 919
5e82d8fe 920 -- When the object is an explicit dereference, convert the
921 -- dereference's prefix.
f947f061 922
5e82d8fe 923 else
924 declare
925 Obj_DDT : constant Entity_Id :=
926 Base_Type
927 (Directly_Designated_Type
928 (Etype (Prefix (Ref_Object))));
929 begin
930 -- No implicit conversion required if designated types
931 -- match.
932
933 if Obj_DDT /= Btyp_DDT
934 and then not (Is_Class_Wide_Type (Obj_DDT)
935 and then Etype (Obj_DDT) = Btyp_DDT)
936 then
937 Rewrite (N,
938 Convert_To (Typ,
939 New_Copy_Tree (Prefix (Ref_Object))));
940 Analyze_And_Resolve (N, Typ);
941 end if;
942 end;
ee6ba406 943 end if;
5e82d8fe 944 end if;
945 end Access_Cases;
ee6ba406 946
947 --------------
948 -- Adjacent --
949 --------------
950
951 -- Transforms 'Adjacent into a call to the floating-point attribute
952 -- function Adjacent in Fat_xxx (where xxx is the root type)
953
954 when Attribute_Adjacent =>
955 Expand_Fpt_Attribute_RR (N);
956
957 -------------
958 -- Address --
959 -------------
960
961 when Attribute_Address => Address : declare
962 Task_Proc : Entity_Id;
963
964 begin
f947f061 965 -- If the prefix is a task or a task type, the useful address is that
966 -- of the procedure for the task body, i.e. the actual program unit.
967 -- We replace the original entity with that of the procedure.
ee6ba406 968
969 if Is_Entity_Name (Pref)
970 and then Is_Task_Type (Entity (Pref))
971 then
d55c93e0 972 Task_Proc := Next_Entity (Root_Type (Ptyp));
ee6ba406 973
974 while Present (Task_Proc) loop
975 exit when Ekind (Task_Proc) = E_Procedure
976 and then Etype (First_Formal (Task_Proc)) =
d55c93e0 977 Corresponding_Record_Type (Ptyp);
ee6ba406 978 Next_Entity (Task_Proc);
979 end loop;
980
981 if Present (Task_Proc) then
982 Set_Entity (Pref, Task_Proc);
983 Set_Etype (Pref, Etype (Task_Proc));
984 end if;
985
986 -- Similarly, the address of a protected operation is the address
987 -- of the corresponding protected body, regardless of the protected
988 -- object from which it is selected.
989
990 elsif Nkind (Pref) = N_Selected_Component
991 and then Is_Subprogram (Entity (Selector_Name (Pref)))
992 and then Is_Protected_Type (Scope (Entity (Selector_Name (Pref))))
993 then
994 Rewrite (Pref,
995 New_Occurrence_Of (
996 External_Subprogram (Entity (Selector_Name (Pref))), Loc));
997
998 elsif Nkind (Pref) = N_Explicit_Dereference
d55c93e0 999 and then Ekind (Ptyp) = E_Subprogram_Type
1000 and then Convention (Ptyp) = Convention_Protected
ee6ba406 1001 then
1002 -- The prefix is be a dereference of an access_to_protected_
1003 -- subprogram. The desired address is the second component of
1004 -- the record that represents the access.
1005
1006 declare
1007 Addr : constant Entity_Id := Etype (N);
1008 Ptr : constant Node_Id := Prefix (Pref);
1009 T : constant Entity_Id :=
1010 Equivalent_Type (Base_Type (Etype (Ptr)));
1011
1012 begin
1013 Rewrite (N,
1014 Unchecked_Convert_To (Addr,
1015 Make_Selected_Component (Loc,
1016 Prefix => Unchecked_Convert_To (T, Ptr),
1017 Selector_Name => New_Occurrence_Of (
1018 Next_Entity (First_Entity (T)), Loc))));
1019
1020 Analyze_And_Resolve (N, Addr);
1021 end;
99f2248e 1022
1023 -- Ada 2005 (AI-251): Class-wide interface objects are always
1024 -- "displaced" to reference the tag associated with the interface
1025 -- type. In order to obtain the real address of such objects we
1026 -- generate a call to a run-time subprogram that returns the base
1027 -- address of the object.
1028
f0bf2ff3 1029 -- This processing is not needed in the VM case, where dispatching
1030 -- issues are taken care of by the virtual machine.
1031
d55c93e0 1032 elsif Is_Class_Wide_Type (Ptyp)
1033 and then Is_Interface (Ptyp)
f0bf2ff3 1034 and then VM_Target = No_VM
83aa52b6 1035 and then not (Nkind (Pref) in N_Has_Entity
1036 and then Is_Subprogram (Entity (Pref)))
99f2248e 1037 then
1038 Rewrite (N,
1039 Make_Function_Call (Loc,
1040 Name => New_Reference_To (RTE (RE_Base_Address), Loc),
1041 Parameter_Associations => New_List (
1042 Relocate_Node (N))));
1043 Analyze (N);
1044 return;
ee6ba406 1045 end if;
1046
d55c93e0 1047 -- Deal with packed array reference, other cases are handled by
1048 -- the back end.
ee6ba406 1049
1050 if Involves_Packed_Array_Reference (Pref) then
1051 Expand_Packed_Address_Reference (N);
1052 end if;
1053 end Address;
1054
9dfe12ae 1055 ---------------
1056 -- Alignment --
1057 ---------------
1058
1059 when Attribute_Alignment => Alignment : declare
9dfe12ae 1060 New_Node : Node_Id;
1061
1062 begin
1063 -- For class-wide types, X'Class'Alignment is transformed into a
1064 -- direct reference to the Alignment of the class type, so that the
1065 -- back end does not have to deal with the X'Class'Alignment
1066 -- reference.
1067
1068 if Is_Entity_Name (Pref)
1069 and then Is_Class_Wide_Type (Entity (Pref))
1070 then
1071 Rewrite (Prefix (N), New_Occurrence_Of (Entity (Pref), Loc));
1072 return;
1073
1074 -- For x'Alignment applied to an object of a class wide type,
1075 -- transform X'Alignment into a call to the predefined primitive
1076 -- operation _Alignment applied to X.
1077
1078 elsif Is_Class_Wide_Type (Ptyp) then
99f2248e 1079
1080 -- No need to do anything else compiling under restriction
1081 -- No_Dispatching_Calls. During the semantic analysis we
1082 -- already notified such violation.
1083
1084 if Restriction_Active (No_Dispatching_Calls) then
1085 return;
1086 end if;
1087
9dfe12ae 1088 New_Node :=
1089 Make_Function_Call (Loc,
1090 Name => New_Reference_To
1091 (Find_Prim_Op (Ptyp, Name_uAlignment), Loc),
1092 Parameter_Associations => New_List (Pref));
1093
1094 if Typ /= Standard_Integer then
1095
1096 -- The context is a specific integer type with which the
1097 -- original attribute was compatible. The function has a
1098 -- specific type as well, so to preserve the compatibility
1099 -- we must convert explicitly.
1100
1101 New_Node := Convert_To (Typ, New_Node);
1102 end if;
1103
1104 Rewrite (N, New_Node);
1105 Analyze_And_Resolve (N, Typ);
1106 return;
1107
1108 -- For all other cases, we just have to deal with the case of
1109 -- the fact that the result can be universal.
1110
1111 else
1112 Apply_Universal_Integer_Attribute_Checks (N);
1113 end if;
1114 end Alignment;
1115
ee6ba406 1116 ---------------
1117 -- AST_Entry --
1118 ---------------
1119
1120 when Attribute_AST_Entry => AST_Entry : declare
1121 Ttyp : Entity_Id;
1122 T_Id : Node_Id;
1123 Eent : Entity_Id;
1124
1125 Entry_Ref : Node_Id;
1126 -- The reference to the entry or entry family
1127
1128 Index : Node_Id;
1129 -- The index expression for an entry family reference, or
1130 -- the Empty if Entry_Ref references a simple entry.
1131
1132 begin
1133 if Nkind (Pref) = N_Indexed_Component then
1134 Entry_Ref := Prefix (Pref);
1135 Index := First (Expressions (Pref));
1136 else
1137 Entry_Ref := Pref;
1138 Index := Empty;
1139 end if;
1140
1141 -- Get expression for Task_Id and the entry entity
1142
1143 if Nkind (Entry_Ref) = N_Selected_Component then
1144 T_Id :=
1145 Make_Attribute_Reference (Loc,
1146 Attribute_Name => Name_Identity,
1147 Prefix => Prefix (Entry_Ref));
1148
1149 Ttyp := Etype (Prefix (Entry_Ref));
1150 Eent := Entity (Selector_Name (Entry_Ref));
1151
1152 else
1153 T_Id :=
1154 Make_Function_Call (Loc,
1155 Name => New_Occurrence_Of (RTE (RE_Current_Task), Loc));
1156
1157 Eent := Entity (Entry_Ref);
1158
1159 -- We have to find the enclosing task to get the task type
1160 -- There must be one, since we already validated this earlier
1161
1162 Ttyp := Current_Scope;
1163 while not Is_Task_Type (Ttyp) loop
1164 Ttyp := Scope (Ttyp);
1165 end loop;
1166 end if;
1167
1168 -- Now rewrite the attribute with a call to Create_AST_Handler
1169
1170 Rewrite (N,
1171 Make_Function_Call (Loc,
1172 Name => New_Occurrence_Of (RTE (RE_Create_AST_Handler), Loc),
1173 Parameter_Associations => New_List (
1174 T_Id,
1175 Entry_Index_Expression (Loc, Eent, Index, Ttyp))));
1176
1177 Analyze_And_Resolve (N, RTE (RE_AST_Handler));
1178 end AST_Entry;
1179
1180 ------------------
1181 -- Bit_Position --
1182 ------------------
1183
d55c93e0 1184 -- We compute this if a component clause was present, otherwise we leave
1185 -- the computation up to the back end, since we don't know what layout
1186 -- will be chosen.
ee6ba406 1187
1188 -- Note that the attribute can apply to a naked record component
1189 -- in generated code (i.e. the prefix is an identifier that
1190 -- references the component or discriminant entity).
1191
1192 when Attribute_Bit_Position => Bit_Position :
1193 declare
1194 CE : Entity_Id;
1195
1196 begin
1197 if Nkind (Pref) = N_Identifier then
1198 CE := Entity (Pref);
1199 else
1200 CE := Entity (Selector_Name (Pref));
1201 end if;
1202
1203 if Known_Static_Component_Bit_Offset (CE) then
1204 Rewrite (N,
1205 Make_Integer_Literal (Loc,
1206 Intval => Component_Bit_Offset (CE)));
1207 Analyze_And_Resolve (N, Typ);
1208
1209 else
1210 Apply_Universal_Integer_Attribute_Checks (N);
1211 end if;
1212 end Bit_Position;
1213
1214 ------------------
1215 -- Body_Version --
1216 ------------------
1217
1218 -- A reference to P'Body_Version or P'Version is expanded to
1219
1220 -- Vnn : Unsigned;
1221 -- pragma Import (C, Vnn, "uuuuT";
1222 -- ...
1223 -- Get_Version_String (Vnn)
1224
1225 -- where uuuu is the unit name (dots replaced by double underscore)
1226 -- and T is B for the cases of Body_Version, or Version applied to a
1227 -- subprogram acting as its own spec, and S for Version applied to a
1228 -- subprogram spec or package. This sequence of code references the
1229 -- the unsigned constant created in the main program by the binder.
1230
1231 -- A special exception occurs for Standard, where the string
7f8eb6ed 1232 -- returned is a copy of the library string in gnatvsn.ads.
ee6ba406 1233
1234 when Attribute_Body_Version | Attribute_Version => Version : declare
1235 E : constant Entity_Id :=
1236 Make_Defining_Identifier (Loc, New_Internal_Name ('V'));
f947f061 1237 Pent : Entity_Id;
ee6ba406 1238 S : String_Id;
1239
1240 begin
1241 -- If not library unit, get to containing library unit
1242
f947f061 1243 Pent := Entity (Pref);
ee6ba406 1244 while Pent /= Standard_Standard
1245 and then Scope (Pent) /= Standard_Standard
f947f061 1246 and then not Is_Child_Unit (Pent)
ee6ba406 1247 loop
1248 Pent := Scope (Pent);
1249 end loop;
1250
f947f061 1251 -- Special case Standard and Standard.ASCII
ee6ba406 1252
f947f061 1253 if Pent = Standard_Standard or else Pent = Standard_ASCII then
ee6ba406 1254 Rewrite (N,
1255 Make_String_Literal (Loc,
5245b786 1256 Strval => Verbose_Library_Version));
ee6ba406 1257
1258 -- All other cases
1259
1260 else
1261 -- Build required string constant
1262
1263 Get_Name_String (Get_Unit_Name (Pent));
1264
1265 Start_String;
1266 for J in 1 .. Name_Len - 2 loop
1267 if Name_Buffer (J) = '.' then
1268 Store_String_Chars ("__");
1269 else
1270 Store_String_Char (Get_Char_Code (Name_Buffer (J)));
1271 end if;
1272 end loop;
1273
1274 -- Case of subprogram acting as its own spec, always use body
1275
1276 if Nkind (Declaration_Node (Pent)) in N_Subprogram_Specification
1277 and then Nkind (Parent (Declaration_Node (Pent))) =
1278 N_Subprogram_Body
1279 and then Acts_As_Spec (Parent (Declaration_Node (Pent)))
1280 then
1281 Store_String_Chars ("B");
1282
1283 -- Case of no body present, always use spec
1284
1285 elsif not Unit_Requires_Body (Pent) then
1286 Store_String_Chars ("S");
1287
1288 -- Otherwise use B for Body_Version, S for spec
1289
1290 elsif Id = Attribute_Body_Version then
1291 Store_String_Chars ("B");
1292 else
1293 Store_String_Chars ("S");
1294 end if;
1295
1296 S := End_String;
1297 Lib.Version_Referenced (S);
1298
1299 -- Insert the object declaration
1300
1301 Insert_Actions (N, New_List (
1302 Make_Object_Declaration (Loc,
1303 Defining_Identifier => E,
1304 Object_Definition =>
1305 New_Occurrence_Of (RTE (RE_Unsigned), Loc))));
1306
1307 -- Set entity as imported with correct external name
1308
1309 Set_Is_Imported (E);
1310 Set_Interface_Name (E, Make_String_Literal (Loc, S));
1311
f947f061 1312 -- Set entity as internal to ensure proper Sprint output of its
1313 -- implicit importation.
1314
1315 Set_Is_Internal (E);
1316
ee6ba406 1317 -- And now rewrite original reference
1318
1319 Rewrite (N,
1320 Make_Function_Call (Loc,
1321 Name => New_Reference_To (RTE (RE_Get_Version_String), Loc),
1322 Parameter_Associations => New_List (
1323 New_Occurrence_Of (E, Loc))));
1324 end if;
1325
1326 Analyze_And_Resolve (N, RTE (RE_Version_String));
1327 end Version;
1328
1329 -------------
1330 -- Ceiling --
1331 -------------
1332
1333 -- Transforms 'Ceiling into a call to the floating-point attribute
1334 -- function Ceiling in Fat_xxx (where xxx is the root type)
1335
1336 when Attribute_Ceiling =>
1337 Expand_Fpt_Attribute_R (N);
1338
1339 --------------
1340 -- Callable --
1341 --------------
1342
aad6babd 1343 -- Transforms 'Callable attribute into a call to the Callable function
ee6ba406 1344
1345 when Attribute_Callable => Callable :
1346 begin
1550b445 1347 -- We have an object of a task interface class-wide type as a prefix
1348 -- to Callable. Generate:
1349
83aa52b6 1350 -- callable (Task_Id (Pref._disp_get_task_id));
1550b445 1351
1352 if Ada_Version >= Ada_05
d55c93e0 1353 and then Ekind (Ptyp) = E_Class_Wide_Type
1354 and then Is_Interface (Ptyp)
1355 and then Is_Task_Interface (Ptyp)
1550b445 1356 then
1357 Rewrite (N,
1358 Make_Function_Call (Loc,
1359 Name =>
1360 New_Reference_To (RTE (RE_Callable), Loc),
1361 Parameter_Associations => New_List (
83aa52b6 1362 Make_Unchecked_Type_Conversion (Loc,
1363 Subtype_Mark =>
1364 New_Reference_To (RTE (RO_ST_Task_Id), Loc),
1365 Expression =>
1366 Make_Selected_Component (Loc,
1367 Prefix =>
1368 New_Copy_Tree (Pref),
1369 Selector_Name =>
1370 Make_Identifier (Loc, Name_uDisp_Get_Task_Id))))));
1371
1550b445 1372 else
1373 Rewrite (N,
1374 Build_Call_With_Task (Pref, RTE (RE_Callable)));
1375 end if;
1376
ee6ba406 1377 Analyze_And_Resolve (N, Standard_Boolean);
1378 end Callable;
1379
1380 ------------
1381 -- Caller --
1382 ------------
1383
1384 -- Transforms 'Caller attribute into a call to either the
1385 -- Task_Entry_Caller or the Protected_Entry_Caller function.
1386
1387 when Attribute_Caller => Caller : declare
7f9be362 1388 Id_Kind : constant Entity_Id := RTE (RO_AT_Task_Id);
9dfe12ae 1389 Ent : constant Entity_Id := Entity (Pref);
1390 Conctype : constant Entity_Id := Scope (Ent);
1391 Nest_Depth : Integer := 0;
ee6ba406 1392 Name : Node_Id;
1393 S : Entity_Id;
1394
1395 begin
1396 -- Protected case
1397
1398 if Is_Protected_Type (Conctype) then
4c06b9d2 1399 case Corresponding_Runtime_Package (Conctype) is
1400 when System_Tasking_Protected_Objects_Entries =>
1401 Name :=
1402 New_Reference_To
1403 (RTE (RE_Protected_Entry_Caller), Loc);
1404
1405 when System_Tasking_Protected_Objects_Single_Entry =>
1406 Name :=
1407 New_Reference_To
1408 (RTE (RE_Protected_Single_Entry_Caller), Loc);
1409
1410 when others =>
1411 raise Program_Error;
1412 end case;
ee6ba406 1413
1414 Rewrite (N,
1415 Unchecked_Convert_To (Id_Kind,
1416 Make_Function_Call (Loc,
1417 Name => Name,
d55c93e0 1418 Parameter_Associations => New_List (
1419 New_Reference_To
1420 (Find_Protection_Object (Current_Scope), Loc)))));
ee6ba406 1421
1422 -- Task case
1423
1424 else
1425 -- Determine the nesting depth of the E'Caller attribute, that
1426 -- is, how many accept statements are nested within the accept
1427 -- statement for E at the point of E'Caller. The runtime uses
1428 -- this depth to find the specified entry call.
1429
1430 for J in reverse 0 .. Scope_Stack.Last loop
1431 S := Scope_Stack.Table (J).Entity;
1432
1433 -- We should not reach the scope of the entry, as it should
1434 -- already have been checked in Sem_Attr that this attribute
1435 -- reference is within a matching accept statement.
1436
1437 pragma Assert (S /= Conctype);
1438
1439 if S = Ent then
1440 exit;
1441
1442 elsif Is_Entry (S) then
1443 Nest_Depth := Nest_Depth + 1;
1444 end if;
1445 end loop;
1446
1447 Rewrite (N,
1448 Unchecked_Convert_To (Id_Kind,
1449 Make_Function_Call (Loc,
d55c93e0 1450 Name =>
1451 New_Reference_To (RTE (RE_Task_Entry_Caller), Loc),
ee6ba406 1452 Parameter_Associations => New_List (
1453 Make_Integer_Literal (Loc,
1454 Intval => Int (Nest_Depth))))));
1455 end if;
1456
1457 Analyze_And_Resolve (N, Id_Kind);
1458 end Caller;
1459
1460 -------------
1461 -- Compose --
1462 -------------
1463
1464 -- Transforms 'Compose into a call to the floating-point attribute
1465 -- function Compose in Fat_xxx (where xxx is the root type)
1466
1467 -- Note: we strictly should have special code here to deal with the
1468 -- case of absurdly negative arguments (less than Integer'First)
1469 -- which will return a (signed) zero value, but it hardly seems
1470 -- worth the effort. Absurdly large positive arguments will raise
1471 -- constraint error which is fine.
1472
1473 when Attribute_Compose =>
1474 Expand_Fpt_Attribute_RI (N);
1475
1476 -----------------
1477 -- Constrained --
1478 -----------------
1479
1480 when Attribute_Constrained => Constrained : declare
1481 Formal_Ent : constant Entity_Id := Param_Entity (Pref);
1482
7f8eb6ed 1483 function Is_Constrained_Aliased_View (Obj : Node_Id) return Boolean;
1484 -- Ada 2005 (AI-363): Returns True if the object name Obj denotes a
1485 -- view of an aliased object whose subtype is constrained.
1486
1487 ---------------------------------
1488 -- Is_Constrained_Aliased_View --
1489 ---------------------------------
1490
1491 function Is_Constrained_Aliased_View (Obj : Node_Id) return Boolean is
1492 E : Entity_Id;
1493
1494 begin
1495 if Is_Entity_Name (Obj) then
1496 E := Entity (Obj);
1497
1498 if Present (Renamed_Object (E)) then
1499 return Is_Constrained_Aliased_View (Renamed_Object (E));
7f8eb6ed 1500 else
1501 return Is_Aliased (E) and then Is_Constrained (Etype (E));
1502 end if;
1503
1504 else
1505 return Is_Aliased_View (Obj)
1506 and then
1507 (Is_Constrained (Etype (Obj))
1508 or else (Nkind (Obj) = N_Explicit_Dereference
1509 and then
1510 not Has_Constrained_Partial_View
1511 (Base_Type (Etype (Obj)))));
1512 end if;
1513 end Is_Constrained_Aliased_View;
1514
1515 -- Start of processing for Constrained
1516
ee6ba406 1517 begin
1518 -- Reference to a parameter where the value is passed as an extra
1519 -- actual, corresponding to the extra formal referenced by the
9dfe12ae 1520 -- Extra_Constrained field of the corresponding formal. If this
1521 -- is an entry in-parameter, it is replaced by a constant renaming
1522 -- for which Extra_Constrained is never created.
ee6ba406 1523
1524 if Present (Formal_Ent)
9dfe12ae 1525 and then Ekind (Formal_Ent) /= E_Constant
ee6ba406 1526 and then Present (Extra_Constrained (Formal_Ent))
1527 then
1528 Rewrite (N,
1529 New_Occurrence_Of
1530 (Extra_Constrained (Formal_Ent), Sloc (N)));
1531
1532 -- For variables with a Extra_Constrained field, we use the
1533 -- corresponding entity.
1534
1535 elsif Nkind (Pref) = N_Identifier
1536 and then Ekind (Entity (Pref)) = E_Variable
1537 and then Present (Extra_Constrained (Entity (Pref)))
1538 then
1539 Rewrite (N,
1540 New_Occurrence_Of
1541 (Extra_Constrained (Entity (Pref)), Sloc (N)));
1542
1543 -- For all other entity names, we can tell at compile time
1544
1545 elsif Is_Entity_Name (Pref) then
1546 declare
1547 Ent : constant Entity_Id := Entity (Pref);
1548 Res : Boolean;
1549
1550 begin
1551 -- (RM J.4) obsolescent cases
1552
1553 if Is_Type (Ent) then
1554
1555 -- Private type
1556
1557 if Is_Private_Type (Ent) then
1558 Res := not Has_Discriminants (Ent)
1559 or else Is_Constrained (Ent);
1560
1561 -- It not a private type, must be a generic actual type
1562 -- that corresponded to a private type. We know that this
1563 -- correspondence holds, since otherwise the reference
1564 -- within the generic template would have been illegal.
1565
1566 else
9dfe12ae 1567 if Is_Composite_Type (Underlying_Type (Ent)) then
1568 Res := Is_Constrained (Ent);
1569 else
1570 Res := True;
1571 end if;
ee6ba406 1572 end if;
1573
1574 -- If the prefix is not a variable or is aliased, then
d55c93e0 1575 -- definitely true; if it's a formal parameter without an
1576 -- associated extra formal, then treat it as constrained.
ee6ba406 1577
7f8eb6ed 1578 -- Ada 2005 (AI-363): An aliased prefix must be known to be
1579 -- constrained in order to set the attribute to True.
1580
ee6ba406 1581 elsif not Is_Variable (Pref)
1582 or else Present (Formal_Ent)
7f8eb6ed 1583 or else (Ada_Version < Ada_05
1584 and then Is_Aliased_View (Pref))
1585 or else (Ada_Version >= Ada_05
1586 and then Is_Constrained_Aliased_View (Pref))
ee6ba406 1587 then
1588 Res := True;
1589
d55c93e0 1590 -- Variable case, look at type to see if it is constrained.
1591 -- Note that the one case where this is not accurate (the
1592 -- procedure formal case), has been handled above.
ee6ba406 1593
99f2248e 1594 -- We use the Underlying_Type here (and below) in case the
1595 -- type is private without discriminants, but the full type
1596 -- has discriminants. This case is illegal, but we generate it
1597 -- internally for passing to the Extra_Constrained parameter.
1598
ee6ba406 1599 else
99f2248e 1600 Res := Is_Constrained (Underlying_Type (Etype (Ent)));
ee6ba406 1601 end if;
1602
1bbc9831 1603 Rewrite (N,
1604 New_Reference_To (Boolean_Literals (Res), Loc));
ee6ba406 1605 end;
1606
d55c93e0 1607 -- Prefix is not an entity name. These are also cases where we can
1608 -- always tell at compile time by looking at the form and type of the
1609 -- prefix. If an explicit dereference of an object with constrained
1610 -- partial view, this is unconstrained (Ada 2005 AI-363).
ee6ba406 1611
1612 else
1bbc9831 1613 Rewrite (N,
1614 New_Reference_To (
1615 Boolean_Literals (
1616 not Is_Variable (Pref)
aad6babd 1617 or else
1618 (Nkind (Pref) = N_Explicit_Dereference
1619 and then
d55c93e0 1620 not Has_Constrained_Partial_View (Base_Type (Ptyp)))
1621 or else Is_Constrained (Underlying_Type (Ptyp))),
1bbc9831 1622 Loc));
ee6ba406 1623 end if;
1624
1625 Analyze_And_Resolve (N, Standard_Boolean);
1626 end Constrained;
1627
1628 ---------------
1629 -- Copy_Sign --
1630 ---------------
1631
1632 -- Transforms 'Copy_Sign into a call to the floating-point attribute
1633 -- function Copy_Sign in Fat_xxx (where xxx is the root type)
1634
1635 when Attribute_Copy_Sign =>
1636 Expand_Fpt_Attribute_RR (N);
1637
1638 -----------
1639 -- Count --
1640 -----------
1641
1642 -- Transforms 'Count attribute into a call to the Count function
1643
d55c93e0 1644 when Attribute_Count => Count : declare
1645 Call : Node_Id;
1646 Conctyp : Entity_Id;
1647 Entnam : Node_Id;
1648 Entry_Id : Entity_Id;
1649 Index : Node_Id;
1650 Name : Node_Id;
ee6ba406 1651
1652 begin
1653 -- If the prefix is a member of an entry family, retrieve both
1654 -- entry name and index. For a simple entry there is no index.
1655
1656 if Nkind (Pref) = N_Indexed_Component then
1657 Entnam := Prefix (Pref);
1658 Index := First (Expressions (Pref));
1659 else
1660 Entnam := Pref;
1661 Index := Empty;
1662 end if;
1663
d55c93e0 1664 Entry_Id := Entity (Entnam);
1665
ee6ba406 1666 -- Find the concurrent type in which this attribute is referenced
1667 -- (there had better be one).
1668
1669 Conctyp := Current_Scope;
1670 while not Is_Concurrent_Type (Conctyp) loop
1671 Conctyp := Scope (Conctyp);
1672 end loop;
1673
1674 -- Protected case
1675
1676 if Is_Protected_Type (Conctyp) then
4c06b9d2 1677 case Corresponding_Runtime_Package (Conctyp) is
1678 when System_Tasking_Protected_Objects_Entries =>
1679 Name := New_Reference_To (RTE (RE_Protected_Count), Loc);
1680
1681 Call :=
1682 Make_Function_Call (Loc,
1683 Name => Name,
1684 Parameter_Associations => New_List (
d55c93e0 1685 New_Reference_To
1686 (Find_Protection_Object (Current_Scope), Loc),
1687 Entry_Index_Expression
1688 (Loc, Entry_Id, Index, Scope (Entry_Id))));
4c06b9d2 1689
1690 when System_Tasking_Protected_Objects_Single_Entry =>
d55c93e0 1691 Name :=
1692 New_Reference_To (RTE (RE_Protected_Count_Entry), Loc);
4c06b9d2 1693
1694 Call :=
1695 Make_Function_Call (Loc,
1696 Name => Name,
1697 Parameter_Associations => New_List (
d55c93e0 1698 New_Reference_To
1699 (Find_Protection_Object (Current_Scope), Loc)));
1700
4c06b9d2 1701 when others =>
1702 raise Program_Error;
4c06b9d2 1703 end case;
ee6ba406 1704
1705 -- Task case
1706
1707 else
1708 Call :=
1709 Make_Function_Call (Loc,
1710 Name => New_Reference_To (RTE (RE_Task_Count), Loc),
1711 Parameter_Associations => New_List (
d55c93e0 1712 Entry_Index_Expression (Loc,
1713 Entry_Id, Index, Scope (Entry_Id))));
ee6ba406 1714 end if;
1715
1716 -- The call returns type Natural but the context is universal integer
1717 -- so any integer type is allowed. The attribute was already resolved
1718 -- so its Etype is the required result type. If the base type of the
1719 -- context type is other than Standard.Integer we put in a conversion
1720 -- to the required type. This can be a normal typed conversion since
1721 -- both input and output types of the conversion are integer types
1722
1723 if Base_Type (Typ) /= Base_Type (Standard_Integer) then
1724 Rewrite (N, Convert_To (Typ, Call));
1725 else
1726 Rewrite (N, Call);
1727 end if;
1728
1729 Analyze_And_Resolve (N, Typ);
1730 end Count;
1731
1732 ---------------
1733 -- Elab_Body --
1734 ---------------
1735
1736 -- This processing is shared by Elab_Spec
1737
1738 -- What we do is to insert the following declarations
1739
1740 -- procedure tnn;
1741 -- pragma Import (C, enn, "name___elabb/s");
1742
1743 -- and then the Elab_Body/Spec attribute is replaced by a reference
1744 -- to this defining identifier.
1745
1746 when Attribute_Elab_Body |
1747 Attribute_Elab_Spec =>
1748
1749 Elab_Body : declare
1750 Ent : constant Entity_Id :=
1751 Make_Defining_Identifier (Loc,
1752 New_Internal_Name ('E'));
1753 Str : String_Id;
1754 Lang : Node_Id;
1755
1756 procedure Make_Elab_String (Nod : Node_Id);
1757 -- Given Nod, an identifier, or a selected component, put the
1758 -- image into the current string literal, with double underline
1759 -- between components.
1760
7f8eb6ed 1761 ----------------------
1762 -- Make_Elab_String --
1763 ----------------------
1764
ee6ba406 1765 procedure Make_Elab_String (Nod : Node_Id) is
1766 begin
1767 if Nkind (Nod) = N_Selected_Component then
1768 Make_Elab_String (Prefix (Nod));
7f8eb6ed 1769
83aa52b6 1770 case VM_Target is
1771 when JVM_Target =>
1772 Store_String_Char ('$');
1773 when CLI_Target =>
1774 Store_String_Char ('.');
1775 when No_VM =>
1776 Store_String_Char ('_');
1777 Store_String_Char ('_');
1778 end case;
ee6ba406 1779
1780 Get_Name_String (Chars (Selector_Name (Nod)));
1781
1782 else
1783 pragma Assert (Nkind (Nod) = N_Identifier);
1784 Get_Name_String (Chars (Nod));
1785 end if;
1786
1787 Store_String_Chars (Name_Buffer (1 .. Name_Len));
1788 end Make_Elab_String;
1789
1790 -- Start of processing for Elab_Body/Elab_Spec
1791
1792 begin
1793 -- First we need to prepare the string literal for the name of
1794 -- the elaboration routine to be referenced.
1795
1796 Start_String;
1797 Make_Elab_String (Pref);
1798
83aa52b6 1799 if VM_Target = No_VM then
ee6ba406 1800 Store_String_Chars ("___elab");
1801 Lang := Make_Identifier (Loc, Name_C);
83aa52b6 1802 else
1803 Store_String_Chars ("._elab");
1804 Lang := Make_Identifier (Loc, Name_Ada);
ee6ba406 1805 end if;
1806
1807 if Id = Attribute_Elab_Body then
1808 Store_String_Char ('b');
1809 else
1810 Store_String_Char ('s');
1811 end if;
1812
1813 Str := End_String;
1814
1815 Insert_Actions (N, New_List (
1816 Make_Subprogram_Declaration (Loc,
1817 Specification =>
1818 Make_Procedure_Specification (Loc,
1819 Defining_Unit_Name => Ent)),
1820
1821 Make_Pragma (Loc,
1822 Chars => Name_Import,
1823 Pragma_Argument_Associations => New_List (
1824 Make_Pragma_Argument_Association (Loc,
1825 Expression => Lang),
1826
1827 Make_Pragma_Argument_Association (Loc,
1828 Expression =>
1829 Make_Identifier (Loc, Chars (Ent))),
1830
1831 Make_Pragma_Argument_Association (Loc,
1832 Expression =>
1833 Make_String_Literal (Loc, Str))))));
1834
1835 Set_Entity (N, Ent);
1836 Rewrite (N, New_Occurrence_Of (Ent, Loc));
1837 end Elab_Body;
1838
1839 ----------------
1840 -- Elaborated --
1841 ----------------
1842
d55c93e0 1843 -- Elaborated is always True for preelaborated units, predefined units,
1844 -- pure units and units which have Elaborate_Body pragmas. These units
1845 -- have no elaboration entity.
ee6ba406 1846
d55c93e0 1847 -- Note: The Elaborated attribute is never passed to the back end
ee6ba406 1848
1849 when Attribute_Elaborated => Elaborated : declare
1850 Ent : constant Entity_Id := Entity (Pref);
1851
1852 begin
1853 if Present (Elaboration_Entity (Ent)) then
1854 Rewrite (N,
1855 New_Occurrence_Of (Elaboration_Entity (Ent), Loc));
1856 else
1857 Rewrite (N, New_Occurrence_Of (Standard_True, Loc));
1858 end if;
1859 end Elaborated;
1860
1861 --------------
1862 -- Enum_Rep --
1863 --------------
1864
1865 when Attribute_Enum_Rep => Enum_Rep :
1866 begin
1867 -- X'Enum_Rep (Y) expands to
1868
1869 -- target-type (Y)
1870
d55c93e0 1871 -- This is simply a direct conversion from the enumeration type to
1872 -- the target integer type, which is treated by the back end as a
1873 -- normal integer conversion, treating the enumeration type as an
1874 -- integer, which is exactly what we want! We set Conversion_OK to
1875 -- make sure that the analyzer does not complain about what otherwise
1876 -- might be an illegal conversion.
ee6ba406 1877
1878 if Is_Non_Empty_List (Exprs) then
1879 Rewrite (N,
1880 OK_Convert_To (Typ, Relocate_Node (First (Exprs))));
1881
1882 -- X'Enum_Rep where X is an enumeration literal is replaced by
1883 -- the literal value.
1884
1885 elsif Ekind (Entity (Pref)) = E_Enumeration_Literal then
1886 Rewrite (N,
1887 Make_Integer_Literal (Loc, Enumeration_Rep (Entity (Pref))));
1888
9dfe12ae 1889 -- If this is a renaming of a literal, recover the representation
1890 -- of the original.
1891
1892 elsif Ekind (Entity (Pref)) = E_Constant
1893 and then Present (Renamed_Object (Entity (Pref)))
1894 and then
1895 Ekind (Entity (Renamed_Object (Entity (Pref))))
1896 = E_Enumeration_Literal
1897 then
1898 Rewrite (N,
1899 Make_Integer_Literal (Loc,
1900 Enumeration_Rep (Entity (Renamed_Object (Entity (Pref))))));
1901
ee6ba406 1902 -- X'Enum_Rep where X is an object does a direct unchecked conversion
1903 -- of the object value, as described for the type case above.
1904
1905 else
1906 Rewrite (N,
1907 OK_Convert_To (Typ, Relocate_Node (Pref)));
1908 end if;
1909
1910 Set_Etype (N, Typ);
1911 Analyze_And_Resolve (N, Typ);
ee6ba406 1912 end Enum_Rep;
1913
d55c93e0 1914 --------------
1915 -- Enum_Val --
1916 --------------
1917
1918 when Attribute_Enum_Val => Enum_Val : declare
1919 Expr : Node_Id;
1920 Btyp : constant Entity_Id := Base_Type (Ptyp);
1921
1922 begin
1923 -- X'Enum_Val (Y) expands to
1924
1925 -- [constraint_error when _rep_to_pos (Y, False) = -1, msg]
1926 -- X!(Y);
1927
1928 Expr := Unchecked_Convert_To (Ptyp, First (Exprs));
1929
1930 Insert_Action (N,
1931 Make_Raise_Constraint_Error (Loc,
1932 Condition =>
1933 Make_Op_Eq (Loc,
1934 Left_Opnd =>
1935 Make_Function_Call (Loc,
1936 Name =>
1937 New_Reference_To (TSS (Btyp, TSS_Rep_To_Pos), Loc),
1938 Parameter_Associations => New_List (
1939 Relocate_Node (Duplicate_Subexpr (Expr)),
1940 New_Occurrence_Of (Standard_False, Loc))),
1941
1942 Right_Opnd => Make_Integer_Literal (Loc, -1)),
1943 Reason => CE_Range_Check_Failed));
1944
1945 Rewrite (N, Expr);
1946 Analyze_And_Resolve (N, Ptyp);
1947 end Enum_Val;
1948
ee6ba406 1949 --------------
1950 -- Exponent --
1951 --------------
1952
1953 -- Transforms 'Exponent into a call to the floating-point attribute
1954 -- function Exponent in Fat_xxx (where xxx is the root type)
1955
1956 when Attribute_Exponent =>
1957 Expand_Fpt_Attribute_R (N);
1958
1959 ------------------
1960 -- External_Tag --
1961 ------------------
1962
1963 -- transforme X'External_Tag into Ada.Tags.External_Tag (X'tag)
1964
1965 when Attribute_External_Tag => External_Tag :
1966 begin
1967 Rewrite (N,
1968 Make_Function_Call (Loc,
1969 Name => New_Reference_To (RTE (RE_External_Tag), Loc),
1970 Parameter_Associations => New_List (
1971 Make_Attribute_Reference (Loc,
1972 Attribute_Name => Name_Tag,
1973 Prefix => Prefix (N)))));
1974
1975 Analyze_And_Resolve (N, Standard_String);
1976 end External_Tag;
1977
1978 -----------
1979 -- First --
1980 -----------
1981
d55c93e0 1982 when Attribute_First =>
ee6ba406 1983
ee6ba406 1984 -- If the prefix type is a constrained packed array type which
1985 -- already has a Packed_Array_Type representation defined, then
1986 -- replace this attribute with a direct reference to 'First of the
d55c93e0 1987 -- appropriate index subtype (since otherwise the back end will try
1988 -- to give us the value of 'First for this implementation type).
ee6ba406 1989
1990 if Is_Constrained_Packed_Array (Ptyp) then
1991 Rewrite (N,
1992 Make_Attribute_Reference (Loc,
1993 Attribute_Name => Name_First,
1994 Prefix => New_Reference_To (Get_Index_Subtype (N), Loc)));
1995 Analyze_And_Resolve (N, Typ);
1996
1997 elsif Is_Access_Type (Ptyp) then
1998 Apply_Access_Check (N);
1999 end if;
ee6ba406 2000
2001 ---------------
2002 -- First_Bit --
2003 ---------------
2004
d55c93e0 2005 -- Compute this if component clause was present, otherwise we leave the
2006 -- computation to be completed in the back-end, since we don't know what
ee6ba406 2007 -- layout will be chosen.
2008
d55c93e0 2009 when Attribute_First_Bit => First_Bit : declare
ee6ba406 2010 CE : constant Entity_Id := Entity (Selector_Name (Pref));
2011
2012 begin
2013 if Known_Static_Component_Bit_Offset (CE) then
2014 Rewrite (N,
2015 Make_Integer_Literal (Loc,
2016 Component_Bit_Offset (CE) mod System_Storage_Unit));
2017
2018 Analyze_And_Resolve (N, Typ);
2019
2020 else
2021 Apply_Universal_Integer_Attribute_Checks (N);
2022 end if;
2023 end First_Bit;
2024
2025 -----------------
2026 -- Fixed_Value --
2027 -----------------
2028
2029 -- We transform:
2030
2031 -- fixtype'Fixed_Value (integer-value)
2032
2033 -- into
2034
2035 -- fixtype(integer-value)
2036
d55c93e0 2037 -- We do all the required analysis of the conversion here, because we do
2038 -- not want this to go through the fixed-point conversion circuits. Note
2039 -- that the back end always treats fixed-point as equivalent to the
2040 -- corresponding integer type anyway.
ee6ba406 2041
2042 when Attribute_Fixed_Value => Fixed_Value :
2043 begin
2044 Rewrite (N,
2045 Make_Type_Conversion (Loc,
2046 Subtype_Mark => New_Occurrence_Of (Entity (Pref), Loc),
2047 Expression => Relocate_Node (First (Exprs))));
2048 Set_Etype (N, Entity (Pref));
2049 Set_Analyzed (N);
9dfe12ae 2050
2051 -- Note: it might appear that a properly analyzed unchecked conversion
2052 -- would be just fine here, but that's not the case, since the full
2053 -- range checks performed by the following call are critical!
2054
ee6ba406 2055 Apply_Type_Conversion_Checks (N);
2056 end Fixed_Value;
2057
2058 -----------
2059 -- Floor --
2060 -----------
2061
2062 -- Transforms 'Floor into a call to the floating-point attribute
2063 -- function Floor in Fat_xxx (where xxx is the root type)
2064
2065 when Attribute_Floor =>
2066 Expand_Fpt_Attribute_R (N);
2067
2068 ----------
2069 -- Fore --
2070 ----------
2071
2072 -- For the fixed-point type Typ:
2073
2074 -- Typ'Fore
2075
2076 -- expands into
2077
1550b445 2078 -- Result_Type (System.Fore (Universal_Real (Type'First)),
2079 -- Universal_Real (Type'Last))
ee6ba406 2080
2081 -- Note that we know that the type is a non-static subtype, or Fore
2082 -- would have itself been computed dynamically in Eval_Attribute.
2083
d55c93e0 2084 when Attribute_Fore => Fore : begin
ee6ba406 2085 Rewrite (N,
2086 Convert_To (Typ,
2087 Make_Function_Call (Loc,
2088 Name => New_Reference_To (RTE (RE_Fore), Loc),
2089
2090 Parameter_Associations => New_List (
1550b445 2091 Convert_To (Universal_Real,
ee6ba406 2092 Make_Attribute_Reference (Loc,
2093 Prefix => New_Reference_To (Ptyp, Loc),
2094 Attribute_Name => Name_First)),
2095
1550b445 2096 Convert_To (Universal_Real,
ee6ba406 2097 Make_Attribute_Reference (Loc,
2098 Prefix => New_Reference_To (Ptyp, Loc),
2099 Attribute_Name => Name_Last))))));
2100
2101 Analyze_And_Resolve (N, Typ);
2102 end Fore;
2103
2104 --------------
2105 -- Fraction --
2106 --------------
2107
2108 -- Transforms 'Fraction into a call to the floating-point attribute
2109 -- function Fraction in Fat_xxx (where xxx is the root type)
2110
2111 when Attribute_Fraction =>
2112 Expand_Fpt_Attribute_R (N);
2113
5690e662 2114 --------------
2115 -- From_Any --
2116 --------------
2117
2118 when Attribute_From_Any => From_Any : declare
2119 P_Type : constant Entity_Id := Etype (Pref);
2120 Decls : constant List_Id := New_List;
2121 begin
2122 Rewrite (N,
2123 Build_From_Any_Call (P_Type,
2124 Relocate_Node (First (Exprs)),
2125 Decls));
2126 Insert_Actions (N, Decls);
2127 Analyze_And_Resolve (N, P_Type);
2128 end From_Any;
2129
ee6ba406 2130 --------------
2131 -- Identity --
2132 --------------
2133
2134 -- For an exception returns a reference to the exception data:
2135 -- Exception_Id!(Prefix'Reference)
2136
2137 -- For a task it returns a reference to the _task_id component of
2138 -- corresponding record:
2139
7f9be362 2140 -- taskV!(Prefix)._Task_Id, converted to the type Task_Id defined
ee6ba406 2141
aad6babd 2142 -- in Ada.Task_Identification
ee6ba406 2143
2144 when Attribute_Identity => Identity : declare
2145 Id_Kind : Entity_Id;
2146
2147 begin
d55c93e0 2148 if Ptyp = Standard_Exception_Type then
ee6ba406 2149 Id_Kind := RTE (RE_Exception_Id);
2150
2151 if Present (Renamed_Object (Entity (Pref))) then
2152 Set_Entity (Pref, Renamed_Object (Entity (Pref)));
2153 end if;
2154
2155 Rewrite (N,
2156 Unchecked_Convert_To (Id_Kind, Make_Reference (Loc, Pref)));
2157 else
7f9be362 2158 Id_Kind := RTE (RO_AT_Task_Id);
ee6ba406 2159
f0bf2ff3 2160 -- If the prefix is a task interface, the Task_Id is obtained
2161 -- dynamically through a dispatching call, as for other task
2162 -- attributes applied to interfaces.
2163
2164 if Ada_Version >= Ada_05
d55c93e0 2165 and then Ekind (Ptyp) = E_Class_Wide_Type
2166 and then Is_Interface (Ptyp)
2167 and then Is_Task_Interface (Ptyp)
f0bf2ff3 2168 then
2169 Rewrite (N,
2170 Unchecked_Convert_To (Id_Kind,
2171 Make_Selected_Component (Loc,
2172 Prefix =>
2173 New_Copy_Tree (Pref),
2174 Selector_Name =>
2175 Make_Identifier (Loc, Name_uDisp_Get_Task_Id))));
2176
2177 else
2178 Rewrite (N,
2179 Unchecked_Convert_To (Id_Kind, Concurrent_Ref (Pref)));
2180 end if;
ee6ba406 2181 end if;
2182
2183 Analyze_And_Resolve (N, Id_Kind);
2184 end Identity;
2185
2186 -----------
2187 -- Image --
2188 -----------
2189
2190 -- Image attribute is handled in separate unit Exp_Imgv
2191
2192 when Attribute_Image =>
2193 Exp_Imgv.Expand_Image_Attribute (N);
2194
2195 ---------
2196 -- Img --
2197 ---------
2198
2199 -- X'Img is expanded to typ'Image (X), where typ is the type of X
2200
2201 when Attribute_Img => Img :
2202 begin
2203 Rewrite (N,
2204 Make_Attribute_Reference (Loc,
d55c93e0 2205 Prefix => New_Reference_To (Ptyp, Loc),
ee6ba406 2206 Attribute_Name => Name_Image,
2207 Expressions => New_List (Relocate_Node (Pref))));
2208
2209 Analyze_And_Resolve (N, Standard_String);
2210 end Img;
2211
2212 -----------
2213 -- Input --
2214 -----------
2215
2216 when Attribute_Input => Input : declare
2217 P_Type : constant Entity_Id := Entity (Pref);
2218 B_Type : constant Entity_Id := Base_Type (P_Type);
2219 U_Type : constant Entity_Id := Underlying_Type (P_Type);
2220 Strm : constant Node_Id := First (Exprs);
2221 Fname : Entity_Id;
2222 Decl : Node_Id;
2223 Call : Node_Id;
2224 Prag : Node_Id;
2225 Arg2 : Node_Id;
2226 Rfunc : Node_Id;
2227
2228 Cntrl : Node_Id := Empty;
2229 -- Value for controlling argument in call. Always Empty except in
2230 -- the dispatching (class-wide type) case, where it is a reference
2231 -- to the dummy object initialized to the right internal tag.
2232
d53a018a 2233 procedure Freeze_Stream_Subprogram (F : Entity_Id);
2234 -- The expansion of the attribute reference may generate a call to
2235 -- a user-defined stream subprogram that is frozen by the call. This
2236 -- can lead to access-before-elaboration problem if the reference
2237 -- appears in an object declaration and the subprogram body has not
2238 -- been seen. The freezing of the subprogram requires special code
2239 -- because it appears in an expanded context where expressions do
2240 -- not freeze their constituents.
2241
2242 ------------------------------
2243 -- Freeze_Stream_Subprogram --
2244 ------------------------------
2245
2246 procedure Freeze_Stream_Subprogram (F : Entity_Id) is
2247 Decl : constant Node_Id := Unit_Declaration_Node (F);
2248 Bod : Node_Id;
2249
2250 begin
2251 -- If this is user-defined subprogram, the corresponding
2252 -- stream function appears as a renaming-as-body, and the
2253 -- user subprogram must be retrieved by tree traversal.
2254
2255 if Present (Decl)
2256 and then Nkind (Decl) = N_Subprogram_Declaration
2257 and then Present (Corresponding_Body (Decl))
2258 then
2259 Bod := Corresponding_Body (Decl);
2260
2261 if Nkind (Unit_Declaration_Node (Bod)) =
2262 N_Subprogram_Renaming_Declaration
2263 then
2264 Set_Is_Frozen (Entity (Name (Unit_Declaration_Node (Bod))));
2265 end if;
2266 end if;
2267 end Freeze_Stream_Subprogram;
2268
2269 -- Start of processing for Input
2270
ee6ba406 2271 begin
2272 -- If no underlying type, we have an error that will be diagnosed
2273 -- elsewhere, so here we just completely ignore the expansion.
2274
2275 if No (U_Type) then
2276 return;
2277 end if;
2278
2279 -- If there is a TSS for Input, just call it
2280
9dfe12ae 2281 Fname := Find_Stream_Subprogram (P_Type, TSS_Stream_Input);
ee6ba406 2282
2283 if Present (Fname) then
2284 null;
2285
2286 else
2287 -- If there is a Stream_Convert pragma, use it, we rewrite
2288
2289 -- sourcetyp'Input (stream)
2290
2291 -- as
2292
2293 -- sourcetyp (streamread (strmtyp'Input (stream)));
2294
2c145f84 2295 -- where streamread is the given Read function that converts an
d55c93e0 2296 -- argument of type strmtyp to type sourcetyp or a type from which
2297 -- it is derived (extra conversion required for the derived case).
ee6ba406 2298
5245b786 2299 Prag := Get_Stream_Convert_Pragma (P_Type);
ee6ba406 2300
2301 if Present (Prag) then
2302 Arg2 := Next (First (Pragma_Argument_Associations (Prag)));
2303 Rfunc := Entity (Expression (Arg2));
2304
2305 Rewrite (N,
2306 Convert_To (B_Type,
2307 Make_Function_Call (Loc,
2308 Name => New_Occurrence_Of (Rfunc, Loc),
2309 Parameter_Associations => New_List (
2310 Make_Attribute_Reference (Loc,
2311 Prefix =>
2312 New_Occurrence_Of
2313 (Etype (First_Formal (Rfunc)), Loc),
2314 Attribute_Name => Name_Input,
2315 Expressions => Exprs)))));
2316
2317 Analyze_And_Resolve (N, B_Type);
2318 return;
2319
2320 -- Elementary types
2321
2322 elsif Is_Elementary_Type (U_Type) then
2323
2324 -- A special case arises if we have a defined _Read routine,
2325 -- since in this case we are required to call this routine.
2326
9dfe12ae 2327 if Present (TSS (Base_Type (U_Type), TSS_Stream_Read)) then
ee6ba406 2328 Build_Record_Or_Elementary_Input_Function
2329 (Loc, U_Type, Decl, Fname);
2330 Insert_Action (N, Decl);
2331
2332 -- For normal cases, we call the I_xxx routine directly
2333
2334 else
2335 Rewrite (N, Build_Elementary_Input_Call (N));
2336 Analyze_And_Resolve (N, P_Type);
2337 return;
2338 end if;
2339
2340 -- Array type case
2341
2342 elsif Is_Array_Type (U_Type) then
2343 Build_Array_Input_Function (Loc, U_Type, Decl, Fname);
2344 Compile_Stream_Body_In_Scope (N, Decl, U_Type, Check => False);
2345
2346 -- Dispatching case with class-wide type
2347
2348 elsif Is_Class_Wide_Type (P_Type) then
2349
99f2248e 2350 -- No need to do anything else compiling under restriction
2351 -- No_Dispatching_Calls. During the semantic analysis we
2352 -- already notified such violation.
2353
2354 if Restriction_Active (No_Dispatching_Calls) then
2355 return;
2356 end if;
2357
ee6ba406 2358 declare
2359 Rtyp : constant Entity_Id := Root_Type (P_Type);
2360 Dnn : Entity_Id;
2361 Decl : Node_Id;
2362
2363 begin
2364 -- Read the internal tag (RM 13.13.2(34)) and use it to
2365 -- initialize a dummy tag object:
2366
2367 -- Dnn : Ada.Tags.Tag
aad6babd 2368 -- := Descendant_Tag (String'Input (Strm), P_Type);
ee6ba406 2369
2370 -- This dummy object is used only to provide a controlling
aad6babd 2371 -- argument for the eventual _Input call. Descendant_Tag is
2372 -- called rather than Internal_Tag to ensure that we have a
2373 -- tag for a type that is descended from the prefix type and
2374 -- declared at the same accessibility level (the exception
2375 -- Tag_Error will be raised otherwise). The level check is
2376 -- required for Ada 2005 because tagged types can be
2377 -- extended in nested scopes (AI-344).
ee6ba406 2378
2379 Dnn :=
2380 Make_Defining_Identifier (Loc,
2381 Chars => New_Internal_Name ('D'));
2382
2383 Decl :=
2384 Make_Object_Declaration (Loc,
2385 Defining_Identifier => Dnn,
2386 Object_Definition =>
2387 New_Occurrence_Of (RTE (RE_Tag), Loc),
2388 Expression =>
2389 Make_Function_Call (Loc,
2390 Name =>
aad6babd 2391 New_Occurrence_Of (RTE (RE_Descendant_Tag), Loc),
ee6ba406 2392 Parameter_Associations => New_List (
2393 Make_Attribute_Reference (Loc,
2394 Prefix =>
2395 New_Occurrence_Of (Standard_String, Loc),
2396 Attribute_Name => Name_Input,
2397 Expressions => New_List (
2398 Relocate_Node
aad6babd 2399 (Duplicate_Subexpr (Strm)))),
2400 Make_Attribute_Reference (Loc,
2401 Prefix => New_Reference_To (P_Type, Loc),
2402 Attribute_Name => Name_Tag))));
ee6ba406 2403
2404 Insert_Action (N, Decl);
2405
2406 -- Now we need to get the entity for the call, and construct
2407 -- a function call node, where we preset a reference to Dnn
aad6babd 2408 -- as the controlling argument (doing an unchecked convert
2409 -- to the class-wide tagged type to make it look like a real
2410 -- tagged object).
ee6ba406 2411
9dfe12ae 2412 Fname := Find_Prim_Op (Rtyp, TSS_Stream_Input);
2413 Cntrl := Unchecked_Convert_To (P_Type,
ee6ba406 2414 New_Occurrence_Of (Dnn, Loc));
9dfe12ae 2415 Set_Etype (Cntrl, P_Type);
ee6ba406 2416 Set_Parent (Cntrl, N);
2417 end;
2418
2419 -- For tagged types, use the primitive Input function
2420
2421 elsif Is_Tagged_Type (U_Type) then
9dfe12ae 2422 Fname := Find_Prim_Op (U_Type, TSS_Stream_Input);
ee6ba406 2423
aad6babd 2424 -- All other record type cases, including protected records. The
2425 -- latter only arise for expander generated code for handling
2426 -- shared passive partition access.
ee6ba406 2427
2428 else
2429 pragma Assert
2430 (Is_Record_Type (U_Type) or else Is_Protected_Type (U_Type));
2431
d55c93e0 2432 -- Ada 2005 (AI-216): Program_Error is raised executing default
2433 -- implementation of the Input attribute of an unchecked union
2434 -- type if the type lacks default discriminant values.
00f91aef 2435
2436 if Is_Unchecked_Union (Base_Type (U_Type))
18a40e97 2437 and then No (Discriminant_Constraint (U_Type))
00f91aef 2438 then
2439 Insert_Action (N,
2440 Make_Raise_Program_Error (Loc,
2441 Reason => PE_Unchecked_Union_Restriction));
2442
2443 return;
2444 end if;
2445
ee6ba406 2446 Build_Record_Or_Elementary_Input_Function
2447 (Loc, Base_Type (U_Type), Decl, Fname);
2448 Insert_Action (N, Decl);
d53a018a 2449
2450 if Nkind (Parent (N)) = N_Object_Declaration
2451 and then Is_Record_Type (U_Type)
2452 then
2453 -- The stream function may contain calls to user-defined
2454 -- Read procedures for individual components.
2455
2456 declare
2457 Comp : Entity_Id;
2458 Func : Entity_Id;
2459
2460 begin
2461 Comp := First_Component (U_Type);
2462 while Present (Comp) loop
2463 Func :=
2464 Find_Stream_Subprogram
2465 (Etype (Comp), TSS_Stream_Read);
2466
2467 if Present (Func) then
2468 Freeze_Stream_Subprogram (Func);
2469 end if;
2470
2471 Next_Component (Comp);
2472 end loop;
2473 end;
2474 end if;
ee6ba406 2475 end if;
2476 end if;
2477
aad6babd 2478 -- If we fall through, Fname is the function to be called. The result
2479 -- is obtained by calling the appropriate function, then converting
2480 -- the result. The conversion does a subtype check.
ee6ba406 2481
2482 Call :=
2483 Make_Function_Call (Loc,
2484 Name => New_Occurrence_Of (Fname, Loc),
2485 Parameter_Associations => New_List (
2486 Relocate_Node (Strm)));
2487
2488 Set_Controlling_Argument (Call, Cntrl);
2489 Rewrite (N, Unchecked_Convert_To (P_Type, Call));
2490 Analyze_And_Resolve (N, P_Type);
d53a018a 2491
2492 if Nkind (Parent (N)) = N_Object_Declaration then
2493 Freeze_Stream_Subprogram (Fname);
2494 end if;
ee6ba406 2495 end Input;
2496
2497 -------------------
2498 -- Integer_Value --
2499 -------------------
2500
2501 -- We transform
2502
2503 -- inttype'Fixed_Value (fixed-value)
2504
2505 -- into
2506
2507 -- inttype(integer-value))
2508
d55c93e0 2509 -- we do all the required analysis of the conversion here, because we do
2510 -- not want this to go through the fixed-point conversion circuits. Note
2511 -- that the back end always treats fixed-point as equivalent to the
2512 -- corresponding integer type anyway.
ee6ba406 2513
2514 when Attribute_Integer_Value => Integer_Value :
2515 begin
2516 Rewrite (N,
2517 Make_Type_Conversion (Loc,
2518 Subtype_Mark => New_Occurrence_Of (Entity (Pref), Loc),
2519 Expression => Relocate_Node (First (Exprs))));
2520 Set_Etype (N, Entity (Pref));
2521 Set_Analyzed (N);
9dfe12ae 2522
2523 -- Note: it might appear that a properly analyzed unchecked conversion
2524 -- would be just fine here, but that's not the case, since the full
2525 -- range checks performed by the following call are critical!
2526
ee6ba406 2527 Apply_Type_Conversion_Checks (N);
2528 end Integer_Value;
2529
d55c93e0 2530 -------------------
2531 -- Invalid_Value --
2532 -------------------
2533
2534 when Attribute_Invalid_Value =>
2535 Rewrite (N, Get_Simple_Init_Val (Ptyp, N));
2536
ee6ba406 2537 ----------
2538 -- Last --
2539 ----------
2540
d55c93e0 2541 when Attribute_Last =>
ee6ba406 2542
ee6ba406 2543 -- If the prefix type is a constrained packed array type which
2544 -- already has a Packed_Array_Type representation defined, then
2545 -- replace this attribute with a direct reference to 'Last of the
d55c93e0 2546 -- appropriate index subtype (since otherwise the back end will try
2547 -- to give us the value of 'Last for this implementation type).
ee6ba406 2548
2549 if Is_Constrained_Packed_Array (Ptyp) then
2550 Rewrite (N,
2551 Make_Attribute_Reference (Loc,
2552 Attribute_Name => Name_Last,
2553 Prefix => New_Reference_To (Get_Index_Subtype (N), Loc)));
2554 Analyze_And_Resolve (N, Typ);
2555
2556 elsif Is_Access_Type (Ptyp) then
2557 Apply_Access_Check (N);
2558 end if;
ee6ba406 2559
2560 --------------
2561 -- Last_Bit --
2562 --------------
2563
d55c93e0 2564 -- We compute this if a component clause was present, otherwise we leave
2565 -- the computation up to the back end, since we don't know what layout
2566 -- will be chosen.
ee6ba406 2567
d55c93e0 2568 when Attribute_Last_Bit => Last_Bit : declare
ee6ba406 2569 CE : constant Entity_Id := Entity (Selector_Name (Pref));
2570
2571 begin
2572 if Known_Static_Component_Bit_Offset (CE)
2573 and then Known_Static_Esize (CE)
2574 then
2575 Rewrite (N,
2576 Make_Integer_Literal (Loc,
2577 Intval => (Component_Bit_Offset (CE) mod System_Storage_Unit)
2578 + Esize (CE) - 1));
2579
2580 Analyze_And_Resolve (N, Typ);
2581
2582 else
2583 Apply_Universal_Integer_Attribute_Checks (N);
2584 end if;
2585 end Last_Bit;
2586
2587 ------------------
2588 -- Leading_Part --
2589 ------------------
2590
2591 -- Transforms 'Leading_Part into a call to the floating-point attribute
2592 -- function Leading_Part in Fat_xxx (where xxx is the root type)
2593
d55c93e0 2594 -- Note: strictly, we should generate special case code to deal with
aad6babd 2595 -- absurdly large positive arguments (greater than Integer'Last), which
2596 -- result in returning the first argument unchanged, but it hardly seems
2597 -- worth the effort. We raise constraint error for absurdly negative
2598 -- arguments which is fine.
ee6ba406 2599
2600 when Attribute_Leading_Part =>
2601 Expand_Fpt_Attribute_RI (N);
2602
2603 ------------
2604 -- Length --
2605 ------------
2606
2607 when Attribute_Length => declare
ee6ba406 2608 Ityp : Entity_Id;
2609 Xnum : Uint;
2610
2611 begin
2612 -- Processing for packed array types
2613
2614 if Is_Array_Type (Ptyp) and then Is_Packed (Ptyp) then
2615 Ityp := Get_Index_Subtype (N);
2616
d55c93e0 2617 -- If the index type, Ityp, is an enumeration type with holes,
2618 -- then we calculate X'Length explicitly using
ee6ba406 2619
2620 -- Typ'Max
2621 -- (0, Ityp'Pos (X'Last (N)) -
2622 -- Ityp'Pos (X'First (N)) + 1);
2623
d55c93e0 2624 -- Since the bounds in the template are the representation values
2625 -- and the back end would get the wrong value.
ee6ba406 2626
2627 if Is_Enumeration_Type (Ityp)
2628 and then Present (Enum_Pos_To_Rep (Base_Type (Ityp)))
2629 then
2630 if No (Exprs) then
2631 Xnum := Uint_1;
2632 else
2633 Xnum := Expr_Value (First (Expressions (N)));
2634 end if;
2635
2636 Rewrite (N,
2637 Make_Attribute_Reference (Loc,
2638 Prefix => New_Occurrence_Of (Typ, Loc),
2639 Attribute_Name => Name_Max,
2640 Expressions => New_List
2641 (Make_Integer_Literal (Loc, 0),
2642
2643 Make_Op_Add (Loc,
2644 Left_Opnd =>
2645 Make_Op_Subtract (Loc,
2646 Left_Opnd =>
2647 Make_Attribute_Reference (Loc,
2648 Prefix => New_Occurrence_Of (Ityp, Loc),
2649 Attribute_Name => Name_Pos,
2650
2651 Expressions => New_List (
2652 Make_Attribute_Reference (Loc,
2653 Prefix => Duplicate_Subexpr (Pref),
2654 Attribute_Name => Name_Last,
2655 Expressions => New_List (
2656 Make_Integer_Literal (Loc, Xnum))))),
2657
2658 Right_Opnd =>
2659 Make_Attribute_Reference (Loc,
2660 Prefix => New_Occurrence_Of (Ityp, Loc),
2661 Attribute_Name => Name_Pos,
2662
2663 Expressions => New_List (
2664 Make_Attribute_Reference (Loc,
9dfe12ae 2665 Prefix =>
2666 Duplicate_Subexpr_No_Checks (Pref),
ee6ba406 2667 Attribute_Name => Name_First,
2668 Expressions => New_List (
2669 Make_Integer_Literal (Loc, Xnum)))))),
2670
2671 Right_Opnd => Make_Integer_Literal (Loc, 1)))));
2672
2673 Analyze_And_Resolve (N, Typ, Suppress => All_Checks);
2674 return;
2675
2676 -- If the prefix type is a constrained packed array type which
2677 -- already has a Packed_Array_Type representation defined, then
2678 -- replace this attribute with a direct reference to 'Range_Length
d55c93e0 2679 -- of the appropriate index subtype (since otherwise the back end
2680 -- will try to give us the value of 'Length for this
2681 -- implementation type).
ee6ba406 2682
2683 elsif Is_Constrained (Ptyp) then
2684 Rewrite (N,
2685 Make_Attribute_Reference (Loc,
2686 Attribute_Name => Name_Range_Length,
2687 Prefix => New_Reference_To (Ityp, Loc)));
2688 Analyze_And_Resolve (N, Typ);
2689 end if;
2690
ee6ba406 2691 -- Access type case
2692
2693 elsif Is_Access_Type (Ptyp) then
2694 Apply_Access_Check (N);
2695
d55c93e0 2696 -- If the designated type is a packed array type, then we convert
2697 -- the reference to:
ee6ba406 2698
2699 -- typ'Max (0, 1 +
2700 -- xtyp'Pos (Pref'Last (Expr)) -
2701 -- xtyp'Pos (Pref'First (Expr)));
2702
d55c93e0 2703 -- This is a bit complex, but it is the easiest thing to do that
2704 -- works in all cases including enum types with holes xtyp here
2705 -- is the appropriate index type.
ee6ba406 2706
2707 declare
2708 Dtyp : constant Entity_Id := Designated_Type (Ptyp);
2709 Xtyp : Entity_Id;
2710
2711 begin
2712 if Is_Array_Type (Dtyp) and then Is_Packed (Dtyp) then
2713 Xtyp := Get_Index_Subtype (N);
2714
2715 Rewrite (N,
2716 Make_Attribute_Reference (Loc,
2717 Prefix => New_Occurrence_Of (Typ, Loc),
2718 Attribute_Name => Name_Max,
2719 Expressions => New_List (
2720 Make_Integer_Literal (Loc, 0),
2721
2722 Make_Op_Add (Loc,
2723 Make_Integer_Literal (Loc, 1),
2724 Make_Op_Subtract (Loc,
2725 Left_Opnd =>
2726 Make_Attribute_Reference (Loc,
2727 Prefix => New_Occurrence_Of (Xtyp, Loc),
2728 Attribute_Name => Name_Pos,
2729 Expressions => New_List (
2730 Make_Attribute_Reference (Loc,
2731 Prefix => Duplicate_Subexpr (Pref),
2732 Attribute_Name => Name_Last,
2733 Expressions =>
2734 New_Copy_List (Exprs)))),
2735
2736 Right_Opnd =>
2737 Make_Attribute_Reference (Loc,
2738 Prefix => New_Occurrence_Of (Xtyp, Loc),
2739 Attribute_Name => Name_Pos,
2740 Expressions => New_List (
2741 Make_Attribute_Reference (Loc,
9dfe12ae 2742 Prefix =>
2743 Duplicate_Subexpr_No_Checks (Pref),
ee6ba406 2744 Attribute_Name => Name_First,
2745 Expressions =>
2746 New_Copy_List (Exprs)))))))));
2747
2748 Analyze_And_Resolve (N, Typ);
2749 end if;
2750 end;
2751
d55c93e0 2752 -- Otherwise leave it to the back end
ee6ba406 2753
2754 else
2755 Apply_Universal_Integer_Attribute_Checks (N);
2756 end if;
2757 end;
2758
2759 -------------
2760 -- Machine --
2761 -------------
2762
2763 -- Transforms 'Machine into a call to the floating-point attribute
2764 -- function Machine in Fat_xxx (where xxx is the root type)
2765
2766 when Attribute_Machine =>
2767 Expand_Fpt_Attribute_R (N);
2768
1550b445 2769 ----------------------
2770 -- Machine_Rounding --
2771 ----------------------
2772
2773 -- Transforms 'Machine_Rounding into a call to the floating-point
2774 -- attribute function Machine_Rounding in Fat_xxx (where xxx is the root
99f2248e 2775 -- type). Expansion is avoided for cases the back end can handle
2776 -- directly.
1550b445 2777
2778 when Attribute_Machine_Rounding =>
99f2248e 2779 if not Is_Inline_Floating_Point_Attribute (N) then
2780 Expand_Fpt_Attribute_R (N);
2781 end if;
1550b445 2782
ee6ba406 2783 ------------------
2784 -- Machine_Size --
2785 ------------------
2786
2787 -- Machine_Size is equivalent to Object_Size, so transform it into
d55c93e0 2788 -- Object_Size and that way the back end never sees Machine_Size.
ee6ba406 2789
2790 when Attribute_Machine_Size =>
2791 Rewrite (N,
2792 Make_Attribute_Reference (Loc,
2793 Prefix => Prefix (N),
2794 Attribute_Name => Name_Object_Size));
2795
2796 Analyze_And_Resolve (N, Typ);
2797
2798 --------------
2799 -- Mantissa --
2800 --------------
2801
aad6babd 2802 -- The only case that can get this far is the dynamic case of the old
d55c93e0 2803 -- Ada 83 Mantissa attribute for the fixed-point case. For this case,
2804 -- we expand:
ee6ba406 2805
2806 -- typ'Mantissa
2807
2808 -- into
2809
2810 -- ityp (System.Mantissa.Mantissa_Value
2811 -- (Integer'Integer_Value (typ'First),
2812 -- Integer'Integer_Value (typ'Last)));
2813
d55c93e0 2814 when Attribute_Mantissa => Mantissa : begin
ee6ba406 2815 Rewrite (N,
2816 Convert_To (Typ,
2817 Make_Function_Call (Loc,
2818 Name => New_Occurrence_Of (RTE (RE_Mantissa_Value), Loc),
2819
2820 Parameter_Associations => New_List (
2821
2822 Make_Attribute_Reference (Loc,
2823 Prefix => New_Occurrence_Of (Standard_Integer, Loc),
2824 Attribute_Name => Name_Integer_Value,
2825 Expressions => New_List (
2826
2827 Make_Attribute_Reference (Loc,
2828 Prefix => New_Occurrence_Of (Ptyp, Loc),
2829 Attribute_Name => Name_First))),
2830
2831 Make_Attribute_Reference (Loc,
2832 Prefix => New_Occurrence_Of (Standard_Integer, Loc),
2833 Attribute_Name => Name_Integer_Value,
2834 Expressions => New_List (
2835
2836 Make_Attribute_Reference (Loc,
2837 Prefix => New_Occurrence_Of (Ptyp, Loc),
2838 Attribute_Name => Name_Last)))))));
2839
2840 Analyze_And_Resolve (N, Typ);
2841 end Mantissa;
2842
18a40e97 2843 --------------------
2844 -- Mechanism_Code --
2845 --------------------
2846
2847 when Attribute_Mechanism_Code =>
2848
2849 -- We must replace the prefix in the renamed case
2850
2851 if Is_Entity_Name (Pref)
2852 and then Present (Alias (Entity (Pref)))
2853 then
2854 Set_Renamed_Subprogram (Pref, Alias (Entity (Pref)));
2855 end if;
2856
e0521a36 2857 ---------
2858 -- Mod --
2859 ---------
2860
2861 when Attribute_Mod => Mod_Case : declare
2862 Arg : constant Node_Id := Relocate_Node (First (Exprs));
2863 Hi : constant Node_Id := Type_High_Bound (Etype (Arg));
2864 Modv : constant Uint := Modulus (Btyp);
2865
2866 begin
2867
2868 -- This is not so simple. The issue is what type to use for the
2869 -- computation of the modular value.
2870
2871 -- The easy case is when the modulus value is within the bounds
2872 -- of the signed integer type of the argument. In this case we can
2873 -- just do the computation in that signed integer type, and then
2874 -- do an ordinary conversion to the target type.
2875
2876 if Modv <= Expr_Value (Hi) then
2877 Rewrite (N,
2878 Convert_To (Btyp,
2879 Make_Op_Mod (Loc,
2880 Left_Opnd => Arg,
2881 Right_Opnd => Make_Integer_Literal (Loc, Modv))));
2882
2883 -- Here we know that the modulus is larger than type'Last of the
9eb397d8 2884 -- integer type. There are two cases to consider:
e0521a36 2885
2886 -- a) The integer value is non-negative. In this case, it is
2887 -- returned as the result (since it is less than the modulus).
2888
aad6babd 2889 -- b) The integer value is negative. In this case, we know that the
2890 -- result is modulus + value, where the value might be as small as
2891 -- -modulus. The trouble is what type do we use to do the subtract.
2892 -- No type will do, since modulus can be as big as 2**64, and no
2c145f84 2893 -- integer type accommodates this value. Let's do bit of algebra
e0521a36 2894
2895 -- modulus + value
2896 -- = modulus - (-value)
2897 -- = (modulus - 1) - (-value - 1)
2898
2899 -- Now modulus - 1 is certainly in range of the modular type.
2900 -- -value is in the range 1 .. modulus, so -value -1 is in the
2901 -- range 0 .. modulus-1 which is in range of the modular type.
2902 -- Furthermore, (-value - 1) can be expressed as -(value + 1)
2903 -- which we can compute using the integer base type.
2904
9eb397d8 2905 -- Once this is done we analyze the conditional expression without
2906 -- range checks, because we know everything is in range, and we
2907 -- want to prevent spurious warnings on either branch.
2908
e0521a36 2909 else
2910 Rewrite (N,
2911 Make_Conditional_Expression (Loc,
2912 Expressions => New_List (
2913 Make_Op_Ge (Loc,
2914 Left_Opnd => Duplicate_Subexpr (Arg),
2915 Right_Opnd => Make_Integer_Literal (Loc, 0)),
2916
2917 Convert_To (Btyp,
2918 Duplicate_Subexpr_No_Checks (Arg)),
2919
2920 Make_Op_Subtract (Loc,
2921 Left_Opnd =>
2922 Make_Integer_Literal (Loc,
2923 Intval => Modv - 1),
2924 Right_Opnd =>
2925 Convert_To (Btyp,
2926 Make_Op_Minus (Loc,
2927 Right_Opnd =>
2928 Make_Op_Add (Loc,
2929 Left_Opnd => Duplicate_Subexpr_No_Checks (Arg),
2930 Right_Opnd =>
2931 Make_Integer_Literal (Loc,
2932 Intval => 1))))))));
2933
e0521a36 2934 end if;
2935
1550b445 2936 Analyze_And_Resolve (N, Btyp, Suppress => All_Checks);
e0521a36 2937 end Mod_Case;
2938
ee6ba406 2939 -----------
2940 -- Model --
2941 -----------
2942
2943 -- Transforms 'Model into a call to the floating-point attribute
2944 -- function Model in Fat_xxx (where xxx is the root type)
2945
2946 when Attribute_Model =>
2947 Expand_Fpt_Attribute_R (N);
2948
2949 -----------------
2950 -- Object_Size --
2951 -----------------
2952
2953 -- The processing for Object_Size shares the processing for Size
2954
4c06b9d2 2955 ---------
2956 -- Old --
2957 ---------
2958
2959 when Attribute_Old => Old : declare
2960 Tnn : constant Entity_Id :=
2961 Make_Defining_Identifier (Loc,
2962 Chars => New_Internal_Name ('T'));
2963 Subp : Node_Id;
2964 Asn_Stm : Node_Id;
2965
2966 begin
d55c93e0 2967 -- Find the nearest subprogram body, ignoring _Preconditions
2968
4c06b9d2 2969 Subp := N;
2970 loop
2971 Subp := Parent (Subp);
d55c93e0 2972 exit when Nkind (Subp) = N_Subprogram_Body
2973 and then Chars (Defining_Entity (Subp)) /= Name_uPostconditions;
4c06b9d2 2974 end loop;
2975
d55c93e0 2976 -- Insert the assignment at the start of the declarations
2977
4c06b9d2 2978 Asn_Stm :=
2979 Make_Object_Declaration (Loc,
2980 Defining_Identifier => Tnn,
2981 Constant_Present => True,
2982 Object_Definition => New_Occurrence_Of (Etype (N), Loc),
2983 Expression => Pref);
2984
2985 if Is_Empty_List (Declarations (Subp)) then
2986 Set_Declarations (Subp, New_List (Asn_Stm));
2987 Analyze (Asn_Stm);
2988 else
2989 Insert_Action (First (Declarations (Subp)), Asn_Stm);
2990 end if;
2991
2992 Rewrite (N, New_Occurrence_Of (Tnn, Loc));
2993 end Old;
2994
ee6ba406 2995 ------------
2996 -- Output --
2997 ------------
2998
2999 when Attribute_Output => Output : declare
3000 P_Type : constant Entity_Id := Entity (Pref);
ee6ba406 3001 U_Type : constant Entity_Id := Underlying_Type (P_Type);
3002 Pname : Entity_Id;
3003 Decl : Node_Id;
3004 Prag : Node_Id;
3005 Arg3 : Node_Id;
3006 Wfunc : Node_Id;
3007
3008 begin
3009 -- If no underlying type, we have an error that will be diagnosed
3010 -- elsewhere, so here we just completely ignore the expansion.
3011
3012 if No (U_Type) then
3013 return;
3014 end if;
3015
3016 -- If TSS for Output is present, just call it
3017
9dfe12ae 3018 Pname := Find_Stream_Subprogram (P_Type, TSS_Stream_Output);
ee6ba406 3019
3020 if Present (Pname) then
3021 null;
3022
3023 else
3024 -- If there is a Stream_Convert pragma, use it, we rewrite
3025
3026 -- sourcetyp'Output (stream, Item)
3027
3028 -- as
3029
3030 -- strmtyp'Output (Stream, strmwrite (acttyp (Item)));
3031
aad6babd 3032 -- where strmwrite is the given Write function that converts an
3033 -- argument of type sourcetyp or a type acctyp, from which it is
3034 -- derived to type strmtyp. The conversion to acttyp is required
3035 -- for the derived case.
ee6ba406 3036
5245b786 3037 Prag := Get_Stream_Convert_Pragma (P_Type);
ee6ba406 3038
3039 if Present (Prag) then
3040 Arg3 :=
3041 Next (Next (First (Pragma_Argument_Associations (Prag))));
3042 Wfunc := Entity (Expression (Arg3));
3043
3044 Rewrite (N,
3045 Make_Attribute_Reference (Loc,
3046 Prefix => New_Occurrence_Of (Etype (Wfunc), Loc),
3047 Attribute_Name => Name_Output,
3048 Expressions => New_List (
3049 Relocate_Node (First (Exprs)),
3050 Make_Function_Call (Loc,
3051 Name => New_Occurrence_Of (Wfunc, Loc),
3052 Parameter_Associations => New_List (
83aa52b6 3053 OK_Convert_To (Etype (First_Formal (Wfunc)),
ee6ba406 3054 Relocate_Node (Next (First (Exprs)))))))));
3055
3056 Analyze (N);
3057 return;
3058
3059 -- For elementary types, we call the W_xxx routine directly.
3060 -- Note that the effect of Write and Output is identical for
3061 -- the case of an elementary type, since there are no
3062 -- discriminants or bounds.
3063
3064 elsif Is_Elementary_Type (U_Type) then
3065
3066 -- A special case arises if we have a defined _Write routine,
3067 -- since in this case we are required to call this routine.
3068
9dfe12ae 3069 if Present (TSS (Base_Type (U_Type), TSS_Stream_Write)) then
ee6ba406 3070 Build_Record_Or_Elementary_Output_Procedure
3071 (Loc, U_Type, Decl, Pname);
3072 Insert_Action (N, Decl);
3073
3074 -- For normal cases, we call the W_xxx routine directly
3075
3076 else
3077 Rewrite (N, Build_Elementary_Write_Call (N));
3078 Analyze (N);
3079 return;
3080 end if;
3081
3082 -- Array type case
3083
3084 elsif Is_Array_Type (U_Type) then
3085 Build_Array_Output_Procedure (Loc, U_Type, Decl, Pname);
3086 Compile_Stream_Body_In_Scope (N, Decl, U_Type, Check => False);
3087
3088 -- Class-wide case, first output external tag, then dispatch
3089 -- to the appropriate primitive Output function (RM 13.13.2(31)).
3090
3091 elsif Is_Class_Wide_Type (P_Type) then
99f2248e 3092
3093 -- No need to do anything else compiling under restriction
3094 -- No_Dispatching_Calls. During the semantic analysis we
3095 -- already notified such violation.
3096
3097 if Restriction_Active (No_Dispatching_Calls) then
3098 return;
3099 end if;
3100
ee6ba406 3101 Tag_Write : declare
3102 Strm : constant Node_Id := First (Exprs);
3103 Item : constant Node_Id := Next (Strm);
3104
3105 begin
83aa52b6 3106 -- Ada 2005 (AI-344): Check that the accessibility level
3107 -- of the type of the output object is not deeper than
3108 -- that of the attribute's prefix type.
3109
aad6babd 3110 -- if Get_Access_Level (Item'Tag)
3111 -- /= Get_Access_Level (P_Type'Tag)
3112 -- then
3113 -- raise Tag_Error;
3114 -- end if;
83aa52b6 3115
aad6babd 3116 -- String'Output (Strm, External_Tag (Item'Tag));
3117
83aa52b6 3118 -- We cannot figure out a practical way to implement this
3119 -- accessibility check on virtual machines, so we omit it.
aad6babd 3120
83aa52b6 3121 if Ada_Version >= Ada_05
3122 and then VM_Target = No_VM
3123 then
aad6babd 3124 Insert_Action (N,
3125 Make_Implicit_If_Statement (N,
3126 Condition =>
3127 Make_Op_Ne (Loc,
3128 Left_Opnd =>
99f2248e 3129 Build_Get_Access_Level (Loc,
3130 Make_Attribute_Reference (Loc,
3131 Prefix =>
3132 Relocate_Node (
3133 Duplicate_Subexpr (Item,
3134 Name_Req => True)),
3135 Attribute_Name => Name_Tag)),
3136
aad6babd 3137 Right_Opnd =>
99f2248e 3138 Make_Integer_Literal (Loc,
3139 Type_Access_Level (P_Type))),
3140
aad6babd 3141 Then_Statements =>
3142 New_List (Make_Raise_Statement (Loc,
3143 New_Occurrence_Of (
3144 RTE (RE_Tag_Error), Loc)))));
3145 end if;
ee6ba406 3146
3147 Insert_Action (N,
3148 Make_Attribute_Reference (Loc,
3149 Prefix => New_Occurrence_Of (Standard_String, Loc),
3150 Attribute_Name => Name_Output,
3151 Expressions => New_List (
3152 Relocate_Node (Duplicate_Subexpr (Strm)),
3153 Make_Function_Call (Loc,
3154 Name =>
3155 New_Occurrence_Of (RTE (RE_External_Tag), Loc),
3156 Parameter_Associations => New_List (
3157 Make_Attribute_Reference (Loc,
3158 Prefix =>
3159 Relocate_Node
3160 (Duplicate_Subexpr (Item, Name_Req => True)),
3161 Attribute_Name => Name_Tag))))));
3162 end Tag_Write;
3163
9dfe12ae 3164 Pname := Find_Prim_Op (U_Type, TSS_Stream_Output);
ee6ba406 3165
3166 -- Tagged type case, use the primitive Output function
3167
3168 elsif Is_Tagged_Type (U_Type) then
9dfe12ae 3169 Pname := Find_Prim_Op (U_Type, TSS_Stream_Output);
ee6ba406 3170
99f2248e 3171 -- All other record type cases, including protected records.
3172 -- The latter only arise for expander generated code for
3173 -- handling shared passive partition access.
ee6ba406 3174
3175 else
3176 pragma Assert
3177 (Is_Record_Type (U_Type) or else Is_Protected_Type (U_Type));
3178
00f91aef 3179 -- Ada 2005 (AI-216): Program_Error is raised when executing
3180 -- the default implementation of the Output attribute of an
3181 -- unchecked union type if the type lacks default discriminant
3182 -- values.
3183
3184 if Is_Unchecked_Union (Base_Type (U_Type))
18a40e97 3185 and then No (Discriminant_Constraint (U_Type))
00f91aef 3186 then
3187 Insert_Action (N,
3188 Make_Raise_Program_Error (Loc,
3189 Reason => PE_Unchecked_Union_Restriction));
3190
3191 return;
3192 end if;
3193
ee6ba406 3194 Build_Record_Or_Elementary_Output_Procedure
3195 (Loc, Base_Type (U_Type), Decl, Pname);
3196 Insert_Action (N, Decl);
3197 end if;
3198 end if;
3199
3200 -- If we fall through, Pname is the name of the procedure to call
3201
3202 Rewrite_Stream_Proc_Call (Pname);
3203 end Output;
3204
3205 ---------
3206 -- Pos --
3207 ---------
3208
3209 -- For enumeration types with a standard representation, Pos is
d55c93e0 3210 -- handled by the back end.
ee6ba406 3211
3212 -- For enumeration types, with a non-standard representation we
3213 -- generate a call to the _Rep_To_Pos function created when the
3214 -- type was frozen. The call has the form
3215
9dfe12ae 3216 -- _rep_to_pos (expr, flag)
ee6ba406 3217
9dfe12ae 3218 -- The parameter flag is True if range checks are enabled, causing
3219 -- Program_Error to be raised if the expression has an invalid
3220 -- representation, and False if range checks are suppressed.
ee6ba406 3221
3222 -- For integer types, Pos is equivalent to a simple integer
3223 -- conversion and we rewrite it as such
3224
3225 when Attribute_Pos => Pos :
3226 declare
3227 Etyp : Entity_Id := Base_Type (Entity (Pref));
3228
3229 begin
3230 -- Deal with zero/non-zero boolean values
3231
3232 if Is_Boolean_Type (Etyp) then
3233 Adjust_Condition (First (Exprs));
3234 Etyp := Standard_Boolean;
3235 Set_Prefix (N, New_Occurrence_Of (Standard_Boolean, Loc));
3236 end if;
3237
3238 -- Case of enumeration type
3239
3240 if Is_Enumeration_Type (Etyp) then
3241
3242 -- Non-standard enumeration type (generate call)
3243
3244 if Present (Enum_Pos_To_Rep (Etyp)) then
9dfe12ae 3245 Append_To (Exprs, Rep_To_Pos_Flag (Etyp, Loc));
ee6ba406 3246 Rewrite (N,
3247 Convert_To (Typ,
3248 Make_Function_Call (Loc,
3249 Name =>
9dfe12ae 3250 New_Reference_To (TSS (Etyp, TSS_Rep_To_Pos), Loc),
ee6ba406 3251 Parameter_Associations => Exprs)));
3252
3253 Analyze_And_Resolve (N, Typ);
3254
3255 -- Standard enumeration type (do universal integer check)
3256
3257 else
3258 Apply_Universal_Integer_Attribute_Checks (N);
3259 end if;
3260
3261 -- Deal with integer types (replace by conversion)
3262
3263 elsif Is_Integer_Type (Etyp) then
3264 Rewrite (N, Convert_To (Typ, First (Exprs)));
3265 Analyze_And_Resolve (N, Typ);
3266 end if;
3267
3268 end Pos;
3269
3270 --------------
3271 -- Position --
3272 --------------
3273
d55c93e0 3274 -- We compute this if a component clause was present, otherwise we leave
3275 -- the computation up to the back end, since we don't know what layout
3276 -- will be chosen.
ee6ba406 3277
3278 when Attribute_Position => Position :
3279 declare
3280 CE : constant Entity_Id := Entity (Selector_Name (Pref));
3281
3282 begin
3283 if Present (Component_Clause (CE)) then
3284 Rewrite (N,
3285 Make_Integer_Literal (Loc,
3286 Intval => Component_Bit_Offset (CE) / System_Storage_Unit));
3287 Analyze_And_Resolve (N, Typ);
3288
3289 else
3290 Apply_Universal_Integer_Attribute_Checks (N);
3291 end if;
3292 end Position;
3293
3294 ----------
3295 -- Pred --
3296 ----------
3297
3298 -- 1. Deal with enumeration types with holes
3299 -- 2. For floating-point, generate call to attribute function
3300 -- 3. For other cases, deal with constraint checking
3301
3302 when Attribute_Pred => Pred :
3303 declare
d55c93e0 3304 Etyp : constant Entity_Id := Base_Type (Ptyp);
ee6ba406 3305
3306 begin
d55c93e0 3307
ee6ba406 3308 -- For enumeration types with non-standard representations, we
3309 -- expand typ'Pred (x) into
3310
3311 -- Pos_To_Rep (Rep_To_Pos (x) - 1)
3312
9dfe12ae 3313 -- If the representation is contiguous, we compute instead
3314 -- Lit1 + Rep_to_Pos (x -1), to catch invalid representations.
d55c93e0 3315 -- The conversion function Enum_Pos_To_Rep is defined on the
3316 -- base type, not the subtype, so we have to use the base type
3317 -- explicitly for this and other enumeration attributes.
9dfe12ae 3318
ee6ba406 3319 if Is_Enumeration_Type (Ptyp)
d55c93e0 3320 and then Present (Enum_Pos_To_Rep (Etyp))
ee6ba406 3321 then
d55c93e0 3322 if Has_Contiguous_Rep (Etyp) then
9dfe12ae 3323 Rewrite (N,
3324 Unchecked_Convert_To (Ptyp,
3325 Make_Op_Add (Loc,
3326 Left_Opnd =>
3327 Make_Integer_Literal (Loc,
3328 Enumeration_Rep (First_Literal (Ptyp))),
3329 Right_Opnd =>
3330 Make_Function_Call (Loc,
3331 Name =>
3332 New_Reference_To
d55c93e0 3333 (TSS (Etyp, TSS_Rep_To_Pos), Loc),
9dfe12ae 3334
3335 Parameter_Associations =>
3336 New_List (
3337 Unchecked_Convert_To (Ptyp,
3338 Make_Op_Subtract (Loc,
3339 Left_Opnd =>
3340 Unchecked_Convert_To (Standard_Integer,
3341 Relocate_Node (First (Exprs))),
3342 Right_Opnd =>
3343 Make_Integer_Literal (Loc, 1))),
3344 Rep_To_Pos_Flag (Ptyp, Loc))))));
ee6ba406 3345
9dfe12ae 3346 else
3347 -- Add Boolean parameter True, to request program errror if
3348 -- we have a bad representation on our hands. If checks are
3349 -- suppressed, then add False instead
ee6ba406 3350
9dfe12ae 3351 Append_To (Exprs, Rep_To_Pos_Flag (Ptyp, Loc));
3352 Rewrite (N,
3353 Make_Indexed_Component (Loc,
d55c93e0 3354 Prefix =>
3355 New_Reference_To
3356 (Enum_Pos_To_Rep (Etyp), Loc),
9dfe12ae 3357 Expressions => New_List (
3358 Make_Op_Subtract (Loc,
ee6ba406 3359 Left_Opnd =>
3360 Make_Function_Call (Loc,
3361 Name =>
d55c93e0 3362 New_Reference_To
3363 (TSS (Etyp, TSS_Rep_To_Pos), Loc),
9dfe12ae 3364 Parameter_Associations => Exprs),
ee6ba406 3365 Right_Opnd => Make_Integer_Literal (Loc, 1)))));
9dfe12ae 3366 end if;
ee6ba406 3367
3368 Analyze_And_Resolve (N, Typ);
3369
3370 -- For floating-point, we transform 'Pred into a call to the Pred
3371 -- floating-point attribute function in Fat_xxx (xxx is root type)
3372
3373 elsif Is_Floating_Point_Type (Ptyp) then
3374 Expand_Fpt_Attribute_R (N);
3375 Analyze_And_Resolve (N, Typ);
3376
3377 -- For modular types, nothing to do (no overflow, since wraps)
3378
3379 elsif Is_Modular_Integer_Type (Ptyp) then
3380 null;
3381
3382 -- For other types, if range checking is enabled, we must generate
3383 -- a check if overflow checking is enabled.
3384
3385 elsif not Overflow_Checks_Suppressed (Ptyp) then
3386 Expand_Pred_Succ (N);
3387 end if;
ee6ba406 3388 end Pred;
3389
7f8eb6ed 3390 --------------
3391 -- Priority --
3392 --------------
3393
3394 -- Ada 2005 (AI-327): Dynamic ceiling priorities
3395
3396 -- We rewrite X'Priority as the following run-time call:
3397
3398 -- Get_Ceiling (X._Object)
3399
3400 -- Note that although X'Priority is notionally an object, it is quite
3401 -- deliberately not defined as an aliased object in the RM. This means
3402 -- that it works fine to rewrite it as a call, without having to worry
3403 -- about complications that would other arise from X'Priority'Access,
3404 -- which is illegal, because of the lack of aliasing.
3405
3406 when Attribute_Priority =>
3407 declare
3408 Call : Node_Id;
3409 Conctyp : Entity_Id;
3410 Object_Parm : Node_Id;
3411 Subprg : Entity_Id;
3412 RT_Subprg_Name : Node_Id;
3413
3414 begin
3415 -- Look for the enclosing concurrent type
3416
3417 Conctyp := Current_Scope;
3418 while not Is_Concurrent_Type (Conctyp) loop
3419 Conctyp := Scope (Conctyp);
3420 end loop;
3421
3422 pragma Assert (Is_Protected_Type (Conctyp));
3423
3424 -- Generate the actual of the call
3425
3426 Subprg := Current_Scope;
3427 while not Present (Protected_Body_Subprogram (Subprg)) loop
3428 Subprg := Scope (Subprg);
3429 end loop;
3430
db14252c 3431 -- Use of 'Priority inside protected entries and barriers (in
3432 -- both cases the type of the first formal of their expanded
3433 -- subprogram is Address)
3434
3435 if Etype (First_Entity (Protected_Body_Subprogram (Subprg)))
3436 = RTE (RE_Address)
3437 then
3438 declare
3439 New_Itype : Entity_Id;
3440
3441 begin
3442 -- In the expansion of protected entries the type of the
3443 -- first formal of the Protected_Body_Subprogram is an
3444 -- Address. In order to reference the _object component
3445 -- we generate:
3446
3447 -- type T is access p__ptTV;
3448 -- freeze T []
3449
3450 New_Itype := Create_Itype (E_Access_Type, N);
3451 Set_Etype (New_Itype, New_Itype);
db14252c 3452 Set_Directly_Designated_Type (New_Itype,
3453 Corresponding_Record_Type (Conctyp));
3454 Freeze_Itype (New_Itype, N);
3455
3456 -- Generate:
3457 -- T!(O)._object'unchecked_access
3458
3459 Object_Parm :=
3460 Make_Attribute_Reference (Loc,
3461 Prefix =>
3462 Make_Selected_Component (Loc,
3463 Prefix =>
3464 Unchecked_Convert_To (New_Itype,
3465 New_Reference_To
7f8eb6ed 3466 (First_Entity
db14252c 3467 (Protected_Body_Subprogram (Subprg)),
3468 Loc)),
3469 Selector_Name =>
3470 Make_Identifier (Loc, Name_uObject)),
3471 Attribute_Name => Name_Unchecked_Access);
3472 end;
3473
3474 -- Use of 'Priority inside a protected subprogram
3475
3476 else
3477 Object_Parm :=
3478 Make_Attribute_Reference (Loc,
3479 Prefix =>
3480 Make_Selected_Component (Loc,
3481 Prefix => New_Reference_To
3482 (First_Entity
3483 (Protected_Body_Subprogram (Subprg)),
3484 Loc),
3485 Selector_Name =>
3486 Make_Identifier (Loc, Name_uObject)),
3487 Attribute_Name => Name_Unchecked_Access);
3488 end if;
7f8eb6ed 3489
3490 -- Select the appropriate run-time subprogram
3491
3492 if Number_Entries (Conctyp) = 0 then
3493 RT_Subprg_Name :=
3494 New_Reference_To (RTE (RE_Get_Ceiling), Loc);
3495 else
3496 RT_Subprg_Name :=
3497 New_Reference_To (RTE (RO_PE_Get_Ceiling), Loc);
3498 end if;
3499
3500 Call :=
3501 Make_Function_Call (Loc,
3502 Name => RT_Subprg_Name,
3503 Parameter_Associations => New_List (Object_Parm));
3504
3505 Rewrite (N, Call);
db14252c 3506
3507 -- Avoid the generation of extra checks on the pointer to the
3508 -- protected object.
3509
3510 Analyze_And_Resolve (N, Typ, Suppress => Access_Check);
7f8eb6ed 3511 end;
3512
ee6ba406 3513 ------------------
3514 -- Range_Length --
3515 ------------------
3516
d55c93e0 3517 when Attribute_Range_Length => Range_Length : begin
ee6ba406 3518 -- The only special processing required is for the case where
3519 -- Range_Length is applied to an enumeration type with holes.
3520 -- In this case we transform
3521
3522 -- X'Range_Length
3523
3524 -- to
3525
3526 -- X'Pos (X'Last) - X'Pos (X'First) + 1
3527
3528 -- So that the result reflects the proper Pos values instead
3529 -- of the underlying representations.
3530
d55c93e0 3531 if Is_Enumeration_Type (Ptyp)
3532 and then Has_Non_Standard_Rep (Ptyp)
ee6ba406 3533 then
3534 Rewrite (N,
3535 Make_Op_Add (Loc,
3536 Left_Opnd =>
3537 Make_Op_Subtract (Loc,
3538 Left_Opnd =>
3539 Make_Attribute_Reference (Loc,
3540 Attribute_Name => Name_Pos,
d55c93e0 3541 Prefix => New_Occurrence_Of (Ptyp, Loc),
ee6ba406 3542 Expressions => New_List (
3543 Make_Attribute_Reference (Loc,
3544 Attribute_Name => Name_Last,
d55c93e0 3545 Prefix => New_Occurrence_Of (Ptyp, Loc)))),
ee6ba406 3546
3547 Right_Opnd =>
3548 Make_Attribute_Reference (Loc,
3549 Attribute_Name => Name_Pos,
d55c93e0 3550 Prefix => New_Occurrence_Of (Ptyp, Loc),
ee6ba406 3551 Expressions => New_List (
3552 Make_Attribute_Reference (Loc,
3553 Attribute_Name => Name_First,
d55c93e0 3554 Prefix => New_Occurrence_Of (Ptyp, Loc))))),
ee6ba406 3555
3556 Right_Opnd =>
3557 Make_Integer_Literal (Loc, 1)));
3558
3559 Analyze_And_Resolve (N, Typ);
3560
d55c93e0 3561 -- For all other cases, the attribute is handled by the back end, but
3562 -- we need to deal with the case of the range check on a universal
3563 -- integer.
ee6ba406 3564
3565 else
3566 Apply_Universal_Integer_Attribute_Checks (N);
3567 end if;
ee6ba406 3568 end Range_Length;
3569
3570 ----------
3571 -- Read --
3572 ----------
3573
3574 when Attribute_Read => Read : declare
3575 P_Type : constant Entity_Id := Entity (Pref);
3576 B_Type : constant Entity_Id := Base_Type (P_Type);
3577 U_Type : constant Entity_Id := Underlying_Type (P_Type);
3578 Pname : Entity_Id;
3579 Decl : Node_Id;
3580 Prag : Node_Id;
3581 Arg2 : Node_Id;
3582 Rfunc : Node_Id;
3583 Lhs : Node_Id;
3584 Rhs : Node_Id;
3585
3586 begin
3587 -- If no underlying type, we have an error that will be diagnosed
3588 -- elsewhere, so here we just completely ignore the expansion.
3589
3590 if No (U_Type) then
3591 return;
3592 end if;
3593
3594 -- The simple case, if there is a TSS for Read, just call it
3595
9dfe12ae 3596 Pname := Find_Stream_Subprogram (P_Type, TSS_Stream_Read);
ee6ba406 3597
3598 if Present (Pname) then
3599 null;
3600
3601 else
3602 -- If there is a Stream_Convert pragma, use it, we rewrite
3603
3604 -- sourcetyp'Read (stream, Item)
3605
3606 -- as
3607
3608 -- Item := sourcetyp (strmread (strmtyp'Input (Stream)));
3609
aad6babd 3610 -- where strmread is the given Read function that converts an
3611 -- argument of type strmtyp to type sourcetyp or a type from which
3612 -- it is derived. The conversion to sourcetyp is required in the
3613 -- latter case.
ee6ba406 3614
3615 -- A special case arises if Item is a type conversion in which
3616 -- case, we have to expand to:
3617
3618 -- Itemx := typex (strmread (strmtyp'Input (Stream)));
3619
3620 -- where Itemx is the expression of the type conversion (i.e.
3621 -- the actual object), and typex is the type of Itemx.
3622
5245b786 3623 Prag := Get_Stream_Convert_Pragma (P_Type);
ee6ba406 3624
3625 if Present (Prag) then
3626 Arg2 := Next (First (Pragma_Argument_Associations (Prag)));
3627 Rfunc := Entity (Expression (Arg2));
3628 Lhs := Relocate_Node (Next (First (Exprs)));
3629 Rhs :=
83aa52b6 3630 OK_Convert_To (B_Type,
ee6ba406 3631 Make_Function_Call (Loc,
3632 Name => New_Occurrence_Of (Rfunc, Loc),
3633 Parameter_Associations => New_List (
3634 Make_Attribute_Reference (Loc,
3635 Prefix =>
3636 New_Occurrence_Of
3637 (Etype (First_Formal (Rfunc)), Loc),
3638 Attribute_Name => Name_Input,
3639 Expressions => New_List (
3640 Relocate_Node (First (Exprs)))))));
3641
3642 if Nkind (Lhs) = N_Type_Conversion then
3643 Lhs := Expression (Lhs);
3644 Rhs := Convert_To (Etype (Lhs), Rhs);
3645 end if;
3646
3647 Rewrite (N,
3648 Make_Assignment_Statement (Loc,
9dfe12ae 3649 Name => Lhs,
ee6ba406 3650 Expression => Rhs));
3651 Set_Assignment_OK (Lhs);
3652 Analyze (N);
3653 return;
3654
3655 -- For elementary types, we call the I_xxx routine using the first
3656 -- parameter and then assign the result into the second parameter.
3657 -- We set Assignment_OK to deal with the conversion case.
3658
3659 elsif Is_Elementary_Type (U_Type) then
3660 declare
3661 Lhs : Node_Id;
3662 Rhs : Node_Id;
3663
3664 begin
3665 Lhs := Relocate_Node (Next (First (Exprs)));
3666 Rhs := Build_Elementary_Input_Call (N);
3667
3668 if Nkind (Lhs) = N_Type_Conversion then
3669 Lhs := Expression (Lhs);
3670 Rhs := Convert_To (Etype (Lhs), Rhs);
3671 end if;
3672
3673 Set_Assignment_OK (Lhs);
3674
3675 Rewrite (N,
3676 Make_Assignment_Statement (Loc,
3677 Name => Lhs,
3678 Expression => Rhs));
3679
3680 Analyze (N);
3681 return;
3682 end;
3683
3684 -- Array type case
3685
3686 elsif Is_Array_Type (U_Type) then
3687 Build_Array_Read_Procedure (N, U_Type, Decl, Pname);
3688 Compile_Stream_Body_In_Scope (N, Decl, U_Type, Check => False);
3689
3690 -- Tagged type case, use the primitive Read function. Note that
3691 -- this will dispatch in the class-wide case which is what we want
3692
3693 elsif Is_Tagged_Type (U_Type) then
9dfe12ae 3694 Pname := Find_Prim_Op (U_Type, TSS_Stream_Read);
ee6ba406 3695
aad6babd 3696 -- All other record type cases, including protected records. The
3697 -- latter only arise for expander generated code for handling
3698 -- shared passive partition access.
ee6ba406 3699
3700 else
3701 pragma Assert
3702 (Is_Record_Type (U_Type) or else Is_Protected_Type (U_Type));
3703
00f91aef 3704 -- Ada 2005 (AI-216): Program_Error is raised when executing
3705 -- the default implementation of the Read attribute of an
3706 -- Unchecked_Union type.
3707
3708 if Is_Unchecked_Union (Base_Type (U_Type)) then
3709 Insert_Action (N,
3710 Make_Raise_Program_Error (Loc,
3711 Reason => PE_Unchecked_Union_Restriction));
3712 end if;
3713
ee6ba406 3714 if Has_Discriminants (U_Type)
3715 and then Present
3716 (Discriminant_Default_Value (First_Discriminant (U_Type)))
3717 then
3718 Build_Mutable_Record_Read_Procedure
3719 (Loc, Base_Type (U_Type), Decl, Pname);
ee6ba406 3720 else
3721 Build_Record_Read_Procedure
3722 (Loc, Base_Type (U_Type), Decl, Pname);
3723 end if;
3724
3725 -- Suppress checks, uninitialized or otherwise invalid
3726 -- data does not cause constraint errors to be raised for
3727 -- a complete record read.
3728
3729 Insert_Action (N, Decl, All_Checks);
3730 end if;
3731 end if;
3732
3733 Rewrite_Stream_Proc_Call (Pname);
3734 end Read;
3735
3736 ---------------
3737 -- Remainder --
3738 ---------------
3739
3740 -- Transforms 'Remainder into a call to the floating-point attribute
3741 -- function Remainder in Fat_xxx (where xxx is the root type)
3742
3743 when Attribute_Remainder =>
3744 Expand_Fpt_Attribute_RR (N);
3745
d55c93e0 3746 ------------
3747 -- Result --
3748 ------------
3749
3750 -- Transform 'Result into reference to _Result formal. At the point
3751 -- where a legal 'Result attribute is expanded, we know that we are in
3752 -- the context of a _Postcondition function with a _Result parameter.
3753
3754 when Attribute_Result =>
3755 Rewrite (N,
3756 Make_Identifier (Loc,
3757 Chars => Name_uResult));
3758 Analyze_And_Resolve (N, Typ);
3759
ee6ba406 3760 -----------
3761 -- Round --
3762 -----------
3763
aad6babd 3764 -- The handling of the Round attribute is quite delicate. The processing
3765 -- in Sem_Attr introduced a conversion to universal real, reflecting the
3766 -- semantics of Round, but we do not want anything to do with universal
3767 -- real at runtime, since this corresponds to using floating-point
3768 -- arithmetic.
3769
3770 -- What we have now is that the Etype of the Round attribute correctly
3771 -- indicates the final result type. The operand of the Round is the
3772 -- conversion to universal real, described above, and the operand of
3773 -- this conversion is the actual operand of Round, which may be the
3774 -- special case of a fixed point multiplication or division (Etype =
3775 -- universal fixed)
3776
3777 -- The exapander will expand first the operand of the conversion, then
3778 -- the conversion, and finally the round attribute itself, since we
3779 -- always work inside out. But we cannot simply process naively in this
3780 -- order. In the semantic world where universal fixed and real really
3781 -- exist and have infinite precision, there is no problem, but in the
3782 -- implementation world, where universal real is a floating-point type,
3783 -- we would get the wrong result.
3784
3785 -- So the approach is as follows. First, when expanding a multiply or
3786 -- divide whose type is universal fixed, we do nothing at all, instead
3787 -- deferring the operation till later.
ee6ba406 3788
3789 -- The actual processing is done in Expand_N_Type_Conversion which
aad6babd 3790 -- handles the special case of Round by looking at its parent to see if
3791 -- it is a Round attribute, and if it is, handling the conversion (or
3792 -- its fixed multiply/divide child) in an appropriate manner.
ee6ba406 3793
3794 -- This means that by the time we get to expanding the Round attribute
3795 -- itself, the Round is nothing more than a type conversion (and will
3796 -- often be a null type conversion), so we just replace it with the
3797 -- appropriate conversion operation.
3798
3799 when Attribute_Round =>
3800 Rewrite (N,
3801 Convert_To (Etype (N), Relocate_Node (First (Exprs))));
3802 Analyze_And_Resolve (N);
3803
3804 --------------
3805 -- Rounding --
3806 --------------
3807
3808 -- Transforms 'Rounding into a call to the floating-point attribute
3809 -- function Rounding in Fat_xxx (where xxx is the root type)
3810
3811 when Attribute_Rounding =>
3812 Expand_Fpt_Attribute_R (N);
3813
3814 -------------
3815 -- Scaling --
3816 -------------
3817
3818 -- Transforms 'Scaling into a call to the floating-point attribute
3819 -- function Scaling in Fat_xxx (where xxx is the root type)
3820
3821 when Attribute_Scaling =>
3822 Expand_Fpt_Attribute_RI (N);
3823
3824 ----------
3825 -- Size --
3826 ----------
3827
3828 when Attribute_Size |
3829 Attribute_Object_Size |
3830 Attribute_Value_Size |
3831 Attribute_VADS_Size => Size :
3832
3833 declare
ee6ba406 3834 Siz : Uint;
9dfe12ae 3835 New_Node : Node_Id;
ee6ba406 3836
3837 begin
3838 -- Processing for VADS_Size case. Note that this processing removes
3839 -- all traces of VADS_Size from the tree, and completes all required
3840 -- processing for VADS_Size by translating the attribute reference
3841 -- to an appropriate Size or Object_Size reference.
3842
3843 if Id = Attribute_VADS_Size
3844 or else (Use_VADS_Size and then Id = Attribute_Size)
3845 then
3846 -- If the size is specified, then we simply use the specified
3847 -- size. This applies to both types and objects. The size of an
3848 -- object can be specified in the following ways:
3849
3850 -- An explicit size object is given for an object
3851 -- A component size is specified for an indexed component
3852 -- A component clause is specified for a selected component
3853 -- The object is a component of a packed composite object
3854
3855 -- If the size is specified, then VADS_Size of an object
3856
3857 if (Is_Entity_Name (Pref)
3858 and then Present (Size_Clause (Entity (Pref))))
3859 or else
3860 (Nkind (Pref) = N_Component_Clause
3861 and then (Present (Component_Clause
3862 (Entity (Selector_Name (Pref))))
3863 or else Is_Packed (Etype (Prefix (Pref)))))
3864 or else
3865 (Nkind (Pref) = N_Indexed_Component
3866 and then (Component_Size (Etype (Prefix (Pref))) /= 0
3867 or else Is_Packed (Etype (Prefix (Pref)))))
3868 then
3869 Set_Attribute_Name (N, Name_Size);
3870
3871 -- Otherwise if we have an object rather than a type, then the
3872 -- VADS_Size attribute applies to the type of the object, rather
3873 -- than the object itself. This is one of the respects in which
3874 -- VADS_Size differs from Size.
3875
3876 else
3877 if (not Is_Entity_Name (Pref)
3878 or else not Is_Type (Entity (Pref)))
d55c93e0 3879 and then (Is_Scalar_Type (Ptyp) or else Is_Constrained (Ptyp))
ee6ba406 3880 then
d55c93e0 3881 Rewrite (Pref, New_Occurrence_Of (Ptyp, Loc));
ee6ba406 3882 end if;
3883
aad6babd 3884 -- For a scalar type for which no size was explicitly given,
3885 -- VADS_Size means Object_Size. This is the other respect in
3886 -- which VADS_Size differs from Size.
ee6ba406 3887
d55c93e0 3888 if Is_Scalar_Type (Ptyp) and then No (Size_Clause (Ptyp)) then
ee6ba406 3889 Set_Attribute_Name (N, Name_Object_Size);
3890
3891 -- In all other cases, Size and VADS_Size are the sane
3892
3893 else
3894 Set_Attribute_Name (N, Name_Size);
3895 end if;
3896 end if;
3897 end if;
3898
d55c93e0 3899 -- For class-wide types, X'Class'Size is transformed into a direct
3900 -- reference to the Size of the class type, so that the back end does
3901 -- not have to deal with the X'Class'Size reference.
ee6ba406 3902
9dfe12ae 3903 if Is_Entity_Name (Pref)
3904 and then Is_Class_Wide_Type (Entity (Pref))
3905 then
3906 Rewrite (Prefix (N), New_Occurrence_Of (Entity (Pref), Loc));
3907 return;
3908
1550b445 3909 -- For X'Size applied to an object of a class-wide type, transform
9dfe12ae 3910 -- X'Size into a call to the primitive operation _Size applied to X.
3911
3912 elsif Is_Class_Wide_Type (Ptyp) then
99f2248e 3913
3914 -- No need to do anything else compiling under restriction
3915 -- No_Dispatching_Calls. During the semantic analysis we
3916 -- already notified such violation.
3917
3918 if Restriction_Active (No_Dispatching_Calls) then
3919 return;
3920 end if;
3921
ee6ba406 3922 New_Node :=
3923 Make_Function_Call (Loc,
3924 Name => New_Reference_To
3925 (Find_Prim_Op (Ptyp, Name_uSize), Loc),
3926 Parameter_Associations => New_List (Pref));
3927
3928 if Typ /= Standard_Long_Long_Integer then
3929
3930 -- The context is a specific integer type with which the
3931 -- original attribute was compatible. The function has a
3932 -- specific type as well, so to preserve the compatibility
3933 -- we must convert explicitly.
3934
3935 New_Node := Convert_To (Typ, New_Node);
3936 end if;
3937
3938 Rewrite (N, New_Node);
3939 Analyze_And_Resolve (N, Typ);
83aa52b6 3940 return;
3941
3942 -- Case of known RM_Size of a type
3943
3944 elsif (Id = Attribute_Size or else Id = Attribute_Value_Size)
3945 and then Is_Entity_Name (Pref)
3946 and then Is_Type (Entity (Pref))
3947 and then Known_Static_RM_Size (Entity (Pref))
3948 then
3949 Siz := RM_Size (Entity (Pref));
3950
3951 -- Case of known Esize of a type
3952
3953 elsif Id = Attribute_Object_Size
3954 and then Is_Entity_Name (Pref)
3955 and then Is_Type (Entity (Pref))
3956 and then Known_Static_Esize (Entity (Pref))
3957 then
3958 Siz := Esize (Entity (Pref));
3959
3960 -- Case of known size of object
3961
3962 elsif Id = Attribute_Size
3963 and then Is_Entity_Name (Pref)
3964 and then Is_Object (Entity (Pref))
3965 and then Known_Esize (Entity (Pref))
3966 and then Known_Static_Esize (Entity (Pref))
3967 then
3968 Siz := Esize (Entity (Pref));
ee6ba406 3969
3970 -- For an array component, we can do Size in the front end
3971 -- if the component_size of the array is set.
3972
3973 elsif Nkind (Pref) = N_Indexed_Component then
3974 Siz := Component_Size (Etype (Prefix (Pref)));
3975
aad6babd 3976 -- For a record component, we can do Size in the front end if there
3977 -- is a component clause, or if the record is packed and the
3978 -- component's size is known at compile time.
ee6ba406 3979
3980 elsif Nkind (Pref) = N_Selected_Component then
3981 declare
3982 Rec : constant Entity_Id := Etype (Prefix (Pref));
3983 Comp : constant Entity_Id := Entity (Selector_Name (Pref));
3984
3985 begin
3986 if Present (Component_Clause (Comp)) then
3987 Siz := Esize (Comp);
3988
3989 elsif Is_Packed (Rec) then
3990 Siz := RM_Size (Ptyp);
3991
3992 else
3993 Apply_Universal_Integer_Attribute_Checks (N);
3994 return;
3995 end if;
3996 end;
3997
d55c93e0 3998 -- All other cases are handled by the back end
ee6ba406 3999
4000 else
4001 Apply_Universal_Integer_Attribute_Checks (N);
4002
1550b445 4003 -- If Size is applied to a formal parameter that is of a packed
4004 -- array subtype, then apply Size to the actual subtype.
ee6ba406 4005
4006 if Is_Entity_Name (Pref)
4007 and then Is_Formal (Entity (Pref))
d55c93e0 4008 and then Is_Array_Type (Ptyp)
4009 and then Is_Packed (Ptyp)
ee6ba406 4010 then
4011 Rewrite (N,
4012 Make_Attribute_Reference (Loc,
4013 Prefix =>
4014 New_Occurrence_Of (Get_Actual_Subtype (Pref), Loc),
4015 Attribute_Name => Name_Size));
4016 Analyze_And_Resolve (N, Typ);
4017 end if;
4018
83aa52b6 4019 -- If Size applies to a dereference of an access to unconstrained
d55c93e0 4020 -- packed array, the back end needs to see its unconstrained
4021 -- nominal type, but also a hint to the actual constrained type.
1550b445 4022
4023 if Nkind (Pref) = N_Explicit_Dereference
d55c93e0 4024 and then Is_Array_Type (Ptyp)
4025 and then not Is_Constrained (Ptyp)
4026 and then Is_Packed (Ptyp)
1550b445 4027 then
4028 Set_Actual_Designated_Subtype (Pref,
4029 Get_Actual_Subtype (Pref));
4030 end if;
4031
ee6ba406 4032 return;
4033 end if;
4034
4035 -- Common processing for record and array component case
4036
83aa52b6 4037 if Siz /= No_Uint and then Siz /= 0 then
6deeca1d 4038 declare
4039 CS : constant Boolean := Comes_From_Source (N);
ee6ba406 4040
6deeca1d 4041 begin
4042 Rewrite (N, Make_Integer_Literal (Loc, Siz));
4043
4044 -- This integer literal is not a static expression. We do not
4045 -- call Analyze_And_Resolve here, because this would activate
4046 -- the circuit for deciding that a static value was out of
4047 -- range, and we don't want that.
ee6ba406 4048
6deeca1d 4049 -- So just manually set the type, mark the expression as non-
4050 -- static, and then ensure that the result is checked properly
4051 -- if the attribute comes from source (if it was internally
4052 -- generated, we never need a constraint check).
ee6ba406 4053
6deeca1d 4054 Set_Etype (N, Typ);
4055 Set_Is_Static_Expression (N, False);
4056
4057 if CS then
4058 Apply_Constraint_Check (N, Typ);
4059 end if;
4060 end;
ee6ba406 4061 end if;
4062 end Size;
4063
4064 ------------------
4065 -- Storage_Pool --
4066 ------------------
4067
4068 when Attribute_Storage_Pool =>
4069 Rewrite (N,
4070 Make_Type_Conversion (Loc,
4071 Subtype_Mark => New_Reference_To (Etype (N), Loc),
4072 Expression => New_Reference_To (Entity (N), Loc)));
4073 Analyze_And_Resolve (N, Typ);
4074
4075 ------------------
4076 -- Storage_Size --
4077 ------------------
4078
d55c93e0 4079 when Attribute_Storage_Size => Storage_Size : begin
ee6ba406 4080
ee6ba406 4081 -- Access type case, always go to the root type
4082
4083 -- The case of access types results in a value of zero for the case
4084 -- where no storage size attribute clause has been given. If a
4085 -- storage size has been given, then the attribute is converted
4086 -- to a reference to the variable used to hold this value.
4087
4088 if Is_Access_Type (Ptyp) then
4089 if Present (Storage_Size_Variable (Root_Type (Ptyp))) then
4090 Rewrite (N,
4091 Make_Attribute_Reference (Loc,
4092 Prefix => New_Reference_To (Typ, Loc),
4093 Attribute_Name => Name_Max,
4094 Expressions => New_List (
4095 Make_Integer_Literal (Loc, 0),
4096 Convert_To (Typ,
4097 New_Reference_To
4098 (Storage_Size_Variable (Root_Type (Ptyp)), Loc)))));
4099
4100 elsif Present (Associated_Storage_Pool (Root_Type (Ptyp))) then
4101 Rewrite (N,
4102 OK_Convert_To (Typ,
4103 Make_Function_Call (Loc,
9dfe12ae 4104 Name =>
4105 New_Reference_To
7f8eb6ed 4106 (Find_Prim_Op
4107 (Etype (Associated_Storage_Pool (Root_Type (Ptyp))),
4108 Attribute_Name (N)),
4109 Loc),
4110
4111 Parameter_Associations => New_List (
4112 New_Reference_To
4113 (Associated_Storage_Pool (Root_Type (Ptyp)), Loc)))));
ee6ba406 4114
ee6ba406 4115 else
4116 Rewrite (N, Make_Integer_Literal (Loc, 0));
4117 end if;
4118
4119 Analyze_And_Resolve (N, Typ);
4120
7f8eb6ed 4121 -- For tasks, we retrieve the size directly from the TCB. The
4122 -- size may depend on a discriminant of the type, and therefore
4123 -- can be a per-object expression, so type-level information is
4124 -- not sufficient in general. There are four cases to consider:
ee6ba406 4125
7f8eb6ed 4126 -- a) If the attribute appears within a task body, the designated
4127 -- TCB is obtained by a call to Self.
ee6ba406 4128
7f8eb6ed 4129 -- b) If the prefix of the attribute is the name of a task object,
4130 -- the designated TCB is the one stored in the corresponding record.
ee6ba406 4131
7f8eb6ed 4132 -- c) If the prefix is a task type, the size is obtained from the
4133 -- size variable created for each task type
ee6ba406 4134
7f8eb6ed 4135 -- d) If no storage_size was specified for the type , there is no
4136 -- size variable, and the value is a system-specific default.
ee6ba406 4137
4138 else
7f8eb6ed 4139 if In_Open_Scopes (Ptyp) then
4140
4141 -- Storage_Size (Self)
4142
ee6ba406 4143 Rewrite (N,
4144 Convert_To (Typ,
4145 Make_Function_Call (Loc,
4146 Name =>
7f8eb6ed 4147 New_Occurrence_Of (RTE (RE_Storage_Size), Loc),
4148 Parameter_Associations =>
4149 New_List (
4150 Make_Function_Call (Loc,
4151 Name =>
4152 New_Reference_To (RTE (RE_Self), Loc))))));
ee6ba406 4153
7f8eb6ed 4154 elsif not Is_Entity_Name (Pref)
4155 or else not Is_Type (Entity (Pref))
4156 then
4157 -- Storage_Size (Rec (Obj).Size)
4158
4159 Rewrite (N,
4160 Convert_To (Typ,
4161 Make_Function_Call (Loc,
4162 Name =>
4163 New_Occurrence_Of (RTE (RE_Storage_Size), Loc),
4164 Parameter_Associations =>
ee6ba406 4165 New_List (
4166 Make_Selected_Component (Loc,
4167 Prefix =>
4168 Unchecked_Convert_To (
4169 Corresponding_Record_Type (Ptyp),
7f8eb6ed 4170 New_Copy_Tree (Pref)),
ee6ba406 4171 Selector_Name =>
7f8eb6ed 4172 Make_Identifier (Loc, Name_uTask_Id))))));
ee6ba406 4173
7f8eb6ed 4174 elsif Present (Storage_Size_Variable (Ptyp)) then
ee6ba406 4175
7f8eb6ed 4176 -- Static storage size pragma given for type: retrieve value
4177 -- from its allocated storage variable.
ee6ba406 4178
7f8eb6ed 4179 Rewrite (N,
4180 Convert_To (Typ,
4181 Make_Function_Call (Loc,
4182 Name => New_Occurrence_Of (
4183 RTE (RE_Adjust_Storage_Size), Loc),
4184 Parameter_Associations =>
4185 New_List (
4186 New_Reference_To (
4187 Storage_Size_Variable (Ptyp), Loc)))));
4188 else
4189 -- Get system default
4190
4191 Rewrite (N,
4192 Convert_To (Typ,
4193 Make_Function_Call (Loc,
4194 Name =>
4195 New_Occurrence_Of (
4196 RTE (RE_Default_Stack_Size), Loc))));
ee6ba406 4197 end if;
7f8eb6ed 4198
4199 Analyze_And_Resolve (N, Typ);
ee6ba406 4200 end if;
4201 end Storage_Size;
4202
7189d17f 4203 -----------------
4204 -- Stream_Size --
4205 -----------------
4206
4207 when Attribute_Stream_Size => Stream_Size : declare
7189d17f 4208 Size : Int;
4209
4210 begin
4211 -- If we have a Stream_Size clause for this type use it, otherwise
4212 -- the Stream_Size if the size of the type.
4213
4214 if Has_Stream_Size_Clause (Ptyp) then
7f8eb6ed 4215 Size :=
4216 UI_To_Int
4217 (Static_Integer (Expression (Stream_Size_Clause (Ptyp))));
7189d17f 4218 else
4219 Size := UI_To_Int (Esize (Ptyp));
4220 end if;
4221
4222 Rewrite (N, Make_Integer_Literal (Loc, Intval => Size));
4223 Analyze_And_Resolve (N, Typ);
4224 end Stream_Size;
4225
ee6ba406 4226 ----------
4227 -- Succ --
4228 ----------
4229
4230 -- 1. Deal with enumeration types with holes
4231 -- 2. For floating-point, generate call to attribute function
4232 -- 3. For other cases, deal with constraint checking
4233
4234 when Attribute_Succ => Succ :
4235 declare
d55c93e0 4236 Etyp : constant Entity_Id := Base_Type (Ptyp);
ee6ba406 4237
4238 begin
d55c93e0 4239
ee6ba406 4240 -- For enumeration types with non-standard representations, we
4241 -- expand typ'Succ (x) into
4242
4243 -- Pos_To_Rep (Rep_To_Pos (x) + 1)
4244
9dfe12ae 4245 -- If the representation is contiguous, we compute instead
4246 -- Lit1 + Rep_to_Pos (x+1), to catch invalid representations.
4247
ee6ba406 4248 if Is_Enumeration_Type (Ptyp)
d55c93e0 4249 and then Present (Enum_Pos_To_Rep (Etyp))
ee6ba406 4250 then
d55c93e0 4251 if Has_Contiguous_Rep (Etyp) then
9dfe12ae 4252 Rewrite (N,
4253 Unchecked_Convert_To (Ptyp,
4254 Make_Op_Add (Loc,
4255 Left_Opnd =>
4256 Make_Integer_Literal (Loc,
4257 Enumeration_Rep (First_Literal (Ptyp))),
4258 Right_Opnd =>
4259 Make_Function_Call (Loc,
4260 Name =>
4261 New_Reference_To
d55c93e0 4262 (TSS (Etyp, TSS_Rep_To_Pos), Loc),
9dfe12ae 4263
4264 Parameter_Associations =>
4265 New_List (
4266 Unchecked_Convert_To (Ptyp,
4267 Make_Op_Add (Loc,
4268 Left_Opnd =>
4269 Unchecked_Convert_To (Standard_Integer,
4270 Relocate_Node (First (Exprs))),
4271 Right_Opnd =>
4272 Make_Integer_Literal (Loc, 1))),
4273 Rep_To_Pos_Flag (Ptyp, Loc))))));
4274 else
4275 -- Add Boolean parameter True, to request program errror if
4276 -- we have a bad representation on our hands. Add False if
4277 -- checks are suppressed.
ee6ba406 4278
9dfe12ae 4279 Append_To (Exprs, Rep_To_Pos_Flag (Ptyp, Loc));
4280 Rewrite (N,
4281 Make_Indexed_Component (Loc,
d55c93e0 4282 Prefix =>
4283 New_Reference_To
4284 (Enum_Pos_To_Rep (Etyp), Loc),
9dfe12ae 4285 Expressions => New_List (
4286 Make_Op_Add (Loc,
4287 Left_Opnd =>
4288 Make_Function_Call (Loc,
4289 Name =>
4290 New_Reference_To
d55c93e0 4291 (TSS (Etyp, TSS_Rep_To_Pos), Loc),
9dfe12ae 4292 Parameter_Associations => Exprs),
4293 Right_Opnd => Make_Integer_Literal (Loc, 1)))));
4294 end if;
ee6ba406 4295
4296 Analyze_And_Resolve (N, Typ);
4297
4298 -- For floating-point, we transform 'Succ into a call to the Succ
4299 -- floating-point attribute function in Fat_xxx (xxx is root type)
4300
4301 elsif Is_Floating_Point_Type (Ptyp) then
4302 Expand_Fpt_Attribute_R (N);
4303 Analyze_And_Resolve (N, Typ);
4304
4305 -- For modular types, nothing to do (no overflow, since wraps)
4306
4307 elsif Is_Modular_Integer_Type (Ptyp) then
4308 null;
4309
4310 -- For other types, if range checking is enabled, we must generate
4311 -- a check if overflow checking is enabled.
4312
4313 elsif not Overflow_Checks_Suppressed (Ptyp) then
4314 Expand_Pred_Succ (N);
4315 end if;
4316 end Succ;
4317
4318 ---------
4319 -- Tag --
4320 ---------
4321
4322 -- Transforms X'Tag into a direct reference to the tag of X
4323
4324 when Attribute_Tag => Tag :
4325 declare
4326 Ttyp : Entity_Id;
4327 Prefix_Is_Type : Boolean;
4328
4329 begin
4330 if Is_Entity_Name (Pref) and then Is_Type (Entity (Pref)) then
4331 Ttyp := Entity (Pref);
4332 Prefix_Is_Type := True;
4333 else
d55c93e0 4334 Ttyp := Ptyp;
ee6ba406 4335 Prefix_Is_Type := False;
4336 end if;
4337
4338 if Is_Class_Wide_Type (Ttyp) then
4339 Ttyp := Root_Type (Ttyp);
4340 end if;
4341
4342 Ttyp := Underlying_Type (Ttyp);
4343
4344 if Prefix_Is_Type then
1d7e0b5b 4345
83aa52b6 4346 -- For VMs we leave the type attribute unexpanded because
1d7e0b5b 4347 -- there's not a dispatching table to reference.
4348
83aa52b6 4349 if VM_Target = No_VM then
1d7e0b5b 4350 Rewrite (N,
4351 Unchecked_Convert_To (RTE (RE_Tag),
4660e715 4352 New_Reference_To
4353 (Node (First_Elmt (Access_Disp_Table (Ttyp))), Loc)));
1d7e0b5b 4354 Analyze_And_Resolve (N, RTE (RE_Tag));
4355 end if;
ee6ba406 4356
83aa52b6 4357 -- (Ada 2005 (AI-251): The use of 'Tag in the sources always
4358 -- references the primary tag of the actual object. If 'Tag is
4359 -- applied to class-wide interface objects we generate code that
4360 -- displaces "this" to reference the base of the object.
4361
4362 elsif Comes_From_Source (N)
4363 and then Is_Class_Wide_Type (Etype (Prefix (N)))
4364 and then Is_Interface (Etype (Prefix (N)))
4365 then
4366 -- Generate:
4367 -- (To_Tag_Ptr (Prefix'Address)).all
4368
4369 -- Note that Prefix'Address is recursively expanded into a call
4370 -- to Base_Address (Obj.Tag)
4371
f0bf2ff3 4372 -- Not needed for VM targets, since all handled by the VM
4373
4374 if VM_Target = No_VM then
4375 Rewrite (N,
4376 Make_Explicit_Dereference (Loc,
4377 Unchecked_Convert_To (RTE (RE_Tag_Ptr),
4378 Make_Attribute_Reference (Loc,
4379 Prefix => Relocate_Node (Pref),
4380 Attribute_Name => Name_Address))));
4381 Analyze_And_Resolve (N, RTE (RE_Tag));
4382 end if;
83aa52b6 4383
ee6ba406 4384 else
4385 Rewrite (N,
4386 Make_Selected_Component (Loc,
4387 Prefix => Relocate_Node (Pref),
4388 Selector_Name =>
4660e715 4389 New_Reference_To (First_Tag_Component (Ttyp), Loc)));
1d7e0b5b 4390 Analyze_And_Resolve (N, RTE (RE_Tag));
ee6ba406 4391 end if;
ee6ba406 4392 end Tag;
4393
4394 ----------------
4395 -- Terminated --
4396 ----------------
4397
aad6babd 4398 -- Transforms 'Terminated attribute into a call to Terminated function
ee6ba406 4399
4400 when Attribute_Terminated => Terminated :
4401 begin
1550b445 4402 -- The prefix of Terminated is of a task interface class-wide type.
4403 -- Generate:
4404
83aa52b6 4405 -- terminated (Task_Id (Pref._disp_get_task_id));
1550b445 4406
4407 if Ada_Version >= Ada_05
d55c93e0 4408 and then Ekind (Ptyp) = E_Class_Wide_Type
4409 and then Is_Interface (Ptyp)
4410 and then Is_Task_Interface (Ptyp)
1550b445 4411 then
4412 Rewrite (N,
4413 Make_Function_Call (Loc,
4414 Name =>
4415 New_Reference_To (RTE (RE_Terminated), Loc),
4416 Parameter_Associations => New_List (
83aa52b6 4417 Make_Unchecked_Type_Conversion (Loc,
4418 Subtype_Mark =>
4419 New_Reference_To (RTE (RO_ST_Task_Id), Loc),
4420 Expression =>
4421 Make_Selected_Component (Loc,
4422 Prefix =>
4423 New_Copy_Tree (Pref),
4424 Selector_Name =>
4425 Make_Identifier (Loc, Name_uDisp_Get_Task_Id))))));
1550b445 4426
4427 elsif Restricted_Profile then
ee6ba406 4428 Rewrite (N,
4429 Build_Call_With_Task (Pref, RTE (RE_Restricted_Terminated)));
4430
4431 else
4432 Rewrite (N,
4433 Build_Call_With_Task (Pref, RTE (RE_Terminated)));
4434 end if;
4435
4436 Analyze_And_Resolve (N, Standard_Boolean);
4437 end Terminated;
4438
4439 ----------------
4440 -- To_Address --
4441 ----------------
4442
4443 -- Transforms System'To_Address (X) into unchecked conversion
4444 -- from (integral) type of X to type address.
4445
4446 when Attribute_To_Address =>
4447 Rewrite (N,
4448 Unchecked_Convert_To (RTE (RE_Address),
4449 Relocate_Node (First (Exprs))));
4450 Analyze_And_Resolve (N, RTE (RE_Address));
4451
5690e662 4452 ------------
4453 -- To_Any --
4454 ------------
4455
4456 when Attribute_To_Any => To_Any : declare
4457 P_Type : constant Entity_Id := Etype (Pref);
4458 Decls : constant List_Id := New_List;
4459 begin
4460 Rewrite (N,
4461 Build_To_Any_Call
4462 (Convert_To (P_Type,
4463 Relocate_Node (First (Exprs))), Decls));
4464 Insert_Actions (N, Decls);
4465 Analyze_And_Resolve (N, RTE (RE_Any));
4466 end To_Any;
4467
ee6ba406 4468 ----------------
4469 -- Truncation --
4470 ----------------
4471
4472 -- Transforms 'Truncation into a call to the floating-point attribute
99f2248e 4473 -- function Truncation in Fat_xxx (where xxx is the root type).
4474 -- Expansion is avoided for cases the back end can handle directly.
ee6ba406 4475
4476 when Attribute_Truncation =>
99f2248e 4477 if not Is_Inline_Floating_Point_Attribute (N) then
4478 Expand_Fpt_Attribute_R (N);
4479 end if;
ee6ba406 4480
5690e662 4481 --------------
4482 -- TypeCode --
4483 --------------
4484
4485 when Attribute_TypeCode => TypeCode : declare
4486 P_Type : constant Entity_Id := Etype (Pref);
4487 Decls : constant List_Id := New_List;
4488 begin
4489 Rewrite (N, Build_TypeCode_Call (Loc, P_Type, Decls));
4490 Insert_Actions (N, Decls);
4491 Analyze_And_Resolve (N, RTE (RE_TypeCode));
4492 end TypeCode;
4493
ee6ba406 4494 -----------------------
4495 -- Unbiased_Rounding --
4496 -----------------------
4497
4498 -- Transforms 'Unbiased_Rounding into a call to the floating-point
4499 -- attribute function Unbiased_Rounding in Fat_xxx (where xxx is the
99f2248e 4500 -- root type). Expansion is avoided for cases the back end can handle
4501 -- directly.
ee6ba406 4502
4503 when Attribute_Unbiased_Rounding =>
99f2248e 4504 if not Is_Inline_Floating_Point_Attribute (N) then
4505 Expand_Fpt_Attribute_R (N);
4506 end if;
ee6ba406 4507
ee6ba406 4508 -----------------
4509 -- UET_Address --
4510 -----------------
4511
4512 when Attribute_UET_Address => UET_Address : declare
4513 Ent : constant Entity_Id :=
4514 Make_Defining_Identifier (Loc, New_Internal_Name ('T'));
4515
4516 begin
4517 Insert_Action (N,
4518 Make_Object_Declaration (Loc,
4519 Defining_Identifier => Ent,
4520 Aliased_Present => True,
4521 Object_Definition =>
4522 New_Occurrence_Of (RTE (RE_Address), Loc)));
4523
4524 -- Construct name __gnat_xxx__SDP, where xxx is the unit name
4525 -- in normal external form.
4526
4527 Get_External_Unit_Name_String (Get_Unit_Name (Pref));
4528 Name_Buffer (1 + 7 .. Name_Len + 7) := Name_Buffer (1 .. Name_Len);
4529 Name_Len := Name_Len + 7;
4530 Name_Buffer (1 .. 7) := "__gnat_";
4531 Name_Buffer (Name_Len + 1 .. Name_Len + 5) := "__SDP";
4532 Name_Len := Name_Len + 5;
4533
4534 Set_Is_Imported (Ent);
4535 Set_Interface_Name (Ent,
4536 Make_String_Literal (Loc,
4537 Strval => String_From_Name_Buffer));
4538
f947f061 4539 -- Set entity as internal to ensure proper Sprint output of its
4540 -- implicit importation.
4541
4542 Set_Is_Internal (Ent);
4543
ee6ba406 4544 Rewrite (N,
4545 Make_Attribute_Reference (Loc,
4546 Prefix => New_Occurrence_Of (Ent, Loc),
4547 Attribute_Name => Name_Address));
4548
4549 Analyze_And_Resolve (N, Typ);
4550 end UET_Address;
4551
ee6ba406 4552 ---------------
4553 -- VADS_Size --
4554 ---------------
4555
4556 -- The processing for VADS_Size is shared with Size
4557
4558 ---------
4559 -- Val --
4560 ---------
4561
4562 -- For enumeration types with a standard representation, and for all
d55c93e0 4563 -- other types, Val is handled by the back end. For enumeration types
4564 -- with a non-standard representation we use the _Pos_To_Rep array that
ee6ba406 4565 -- was created when the type was frozen.
4566
4567 when Attribute_Val => Val :
4568 declare
4569 Etyp : constant Entity_Id := Base_Type (Entity (Pref));
4570
4571 begin
4572 if Is_Enumeration_Type (Etyp)
4573 and then Present (Enum_Pos_To_Rep (Etyp))
4574 then
9dfe12ae 4575 if Has_Contiguous_Rep (Etyp) then
4576 declare
4577 Rep_Node : constant Node_Id :=
4578 Unchecked_Convert_To (Etyp,
4579 Make_Op_Add (Loc,
4580 Left_Opnd =>
4581 Make_Integer_Literal (Loc,
4582 Enumeration_Rep (First_Literal (Etyp))),
4583 Right_Opnd =>
4584 (Convert_To (Standard_Integer,
4585 Relocate_Node (First (Exprs))))));
4586
4587 begin
4588 Rewrite (N,
4589 Unchecked_Convert_To (Etyp,
4590 Make_Op_Add (Loc,
4591 Left_Opnd =>
4592 Make_Integer_Literal (Loc,
4593 Enumeration_Rep (First_Literal (Etyp))),
4594 Right_Opnd =>
4595 Make_Function_Call (Loc,
4596 Name =>
4597 New_Reference_To
4598 (TSS (Etyp, TSS_Rep_To_Pos), Loc),
4599 Parameter_Associations => New_List (
4600 Rep_Node,
4601 Rep_To_Pos_Flag (Etyp, Loc))))));
4602 end;
4603
4604 else
4605 Rewrite (N,
4606 Make_Indexed_Component (Loc,
4607 Prefix => New_Reference_To (Enum_Pos_To_Rep (Etyp), Loc),
4608 Expressions => New_List (
4609 Convert_To (Standard_Integer,
4610 Relocate_Node (First (Exprs))))));
4611 end if;
ee6ba406 4612
4613 Analyze_And_Resolve (N, Typ);
4614 end if;
4615 end Val;
4616
4617 -----------
4618 -- Valid --
4619 -----------
4620
4621 -- The code for valid is dependent on the particular types involved.
4622 -- See separate sections below for the generated code in each case.
4623
4624 when Attribute_Valid => Valid :
4625 declare
d55c93e0 4626 Btyp : Entity_Id := Base_Type (Ptyp);
ee6ba406 4627 Tst : Node_Id;
4628
9dfe12ae 4629 Save_Validity_Checks_On : constant Boolean := Validity_Checks_On;
4630 -- Save the validity checking mode. We always turn off validity
4631 -- checking during process of 'Valid since this is one place
4632 -- where we do not want the implicit validity checks to intefere
4633 -- with the explicit validity check that the programmer is doing.
4634
ee6ba406 4635 function Make_Range_Test return Node_Id;
4636 -- Build the code for a range test of the form
4637 -- Btyp!(Pref) >= Btyp!(Ptyp'First)
4638 -- and then
4639 -- Btyp!(Pref) <= Btyp!(Ptyp'Last)
4640
9dfe12ae 4641 ---------------------
4642 -- Make_Range_Test --
4643 ---------------------
4644
ee6ba406 4645 function Make_Range_Test return Node_Id is
4646 begin
4647 return
4648 Make_And_Then (Loc,
4649 Left_Opnd =>
4650 Make_Op_Ge (Loc,
4651 Left_Opnd =>
4652 Unchecked_Convert_To (Btyp, Duplicate_Subexpr (Pref)),
4653
4654 Right_Opnd =>
4655 Unchecked_Convert_To (Btyp,
4656 Make_Attribute_Reference (Loc,
4657 Prefix => New_Occurrence_Of (Ptyp, Loc),
4658 Attribute_Name => Name_First))),
4659
4660 Right_Opnd =>
4661 Make_Op_Le (Loc,
4662 Left_Opnd =>
9dfe12ae 4663 Unchecked_Convert_To (Btyp,
4664 Duplicate_Subexpr_No_Checks (Pref)),
ee6ba406 4665
4666 Right_Opnd =>
4667 Unchecked_Convert_To (Btyp,
4668 Make_Attribute_Reference (Loc,
4669 Prefix => New_Occurrence_Of (Ptyp, Loc),
4670 Attribute_Name => Name_Last))));
4671 end Make_Range_Test;
4672
4673 -- Start of processing for Attribute_Valid
4674
4675 begin
9dfe12ae 4676 -- Turn off validity checks. We do not want any implicit validity
4677 -- checks to intefere with the explicit check from the attribute
4678
4679 Validity_Checks_On := False;
4680
ee6ba406 4681 -- Floating-point case. This case is handled by the Valid attribute
4682 -- code in the floating-point attribute run-time library.
4683
4684 if Is_Floating_Point_Type (Ptyp) then
4685 declare
1550b445 4686 Pkg : RE_Id;
4687 Ftp : Entity_Id;
ee6ba406 4688
4689 begin
6e62b6c3 4690 -- For vax fpt types, call appropriate routine in special vax
4691 -- floating point unit. We do not have to worry about loads in
4692 -- this case, since these types have no signalling NaN's.
4693
1550b445 4694 if Vax_Float (Btyp) then
6e62b6c3 4695 Expand_Vax_Valid (N);
4696
7f8eb6ed 4697 -- The AAMP back end handles Valid for floating-point types
4698
4699 elsif Is_AAMP_Float (Btyp) then
4700 Analyze_And_Resolve (Pref, Ptyp);
4701 Set_Etype (N, Standard_Boolean);
4702 Set_Analyzed (N);
4703
1550b445 4704 -- Non VAX float case
9dfe12ae 4705
1550b445 4706 else
d55c93e0 4707 Find_Fat_Info (Ptyp, Ftp, Pkg);
1550b445 4708
4709 -- If the floating-point object might be unaligned, we need
4710 -- to call the special routine Unaligned_Valid, which makes
4711 -- the needed copy, being careful not to load the value into
4712 -- any floating-point register. The argument in this case is
99f2248e 4713 -- obj'Address (see Unaligned_Valid routine in Fat_Gen).
1550b445 4714
4715 if Is_Possibly_Unaligned_Object (Pref) then
1550b445 4716 Expand_Fpt_Attribute
4717 (N, Pkg, Name_Unaligned_Valid,
4718 New_List (
4719 Make_Attribute_Reference (Loc,
4720 Prefix => Relocate_Node (Pref),
4721 Attribute_Name => Name_Address)));
9dfe12ae 4722
1550b445 4723 -- In the normal case where we are sure the object is
4724 -- aligned, we generate a call to Valid, and the argument in
4725 -- this case is obj'Unrestricted_Access (after converting
4726 -- obj to the right floating-point type).
9dfe12ae 4727
1550b445 4728 else
4729 Expand_Fpt_Attribute
4730 (N, Pkg, Name_Valid,
4731 New_List (
4732 Make_Attribute_Reference (Loc,
4733 Prefix => Unchecked_Convert_To (Ftp, Pref),
4734 Attribute_Name => Name_Unrestricted_Access)));
4735 end if;
9dfe12ae 4736 end if;
ee6ba406 4737
4738 -- One more task, we still need a range check. Required
4739 -- only if we have a constraint, since the Valid routine
4740 -- catches infinities properly (infinities are never valid).
4741
4742 -- The way we do the range check is simply to create the
4743 -- expression: Valid (N) and then Base_Type(Pref) in Typ.
4744
4745 if not Subtypes_Statically_Match (Ptyp, Btyp) then
4746 Rewrite (N,
4747 Make_And_Then (Loc,
4748 Left_Opnd => Relocate_Node (N),
4749 Right_Opnd =>
4750 Make_In (Loc,
4751 Left_Opnd => Convert_To (Btyp, Pref),
4752 Right_Opnd => New_Occurrence_Of (Ptyp, Loc))));
4753 end if;
4754 end;
4755
4756 -- Enumeration type with holes
4757
4758 -- For enumeration types with holes, the Pos value constructed by
4759 -- the Enum_Rep_To_Pos function built in Exp_Ch3 called with a
4760 -- second argument of False returns minus one for an invalid value,
4761 -- and the non-negative pos value for a valid value, so the
4762 -- expansion of X'Valid is simply:
4763
4764 -- type(X)'Pos (X) >= 0
4765
4766 -- We can't quite generate it that way because of the requirement
5329ca64 4767 -- for the non-standard second argument of False in the resulting
4768 -- rep_to_pos call, so we have to explicitly create:
ee6ba406 4769
4770 -- _rep_to_pos (X, False) >= 0
4771
4772 -- If we have an enumeration subtype, we also check that the
4773 -- value is in range:
4774
4775 -- _rep_to_pos (X, False) >= 0
4776 -- and then
5329ca64 4777 -- (X >= type(X)'First and then type(X)'Last <= X)
ee6ba406 4778
4779 elsif Is_Enumeration_Type (Ptyp)
4780 and then Present (Enum_Pos_To_Rep (Base_Type (Ptyp)))
4781 then
4782 Tst :=
4783 Make_Op_Ge (Loc,
4784 Left_Opnd =>
4785 Make_Function_Call (Loc,
4786 Name =>
4787 New_Reference_To
9dfe12ae 4788 (TSS (Base_Type (Ptyp), TSS_Rep_To_Pos), Loc),
ee6ba406 4789 Parameter_Associations => New_List (
4790 Pref,
4791 New_Occurrence_Of (Standard_False, Loc))),
4792 Right_Opnd => Make_Integer_Literal (Loc, 0));
4793
4794 if Ptyp /= Btyp
4795 and then
4796 (Type_Low_Bound (Ptyp) /= Type_Low_Bound (Btyp)
4797 or else
4798 Type_High_Bound (Ptyp) /= Type_High_Bound (Btyp))
4799 then
4800 -- The call to Make_Range_Test will create declarations
4801 -- that need a proper insertion point, but Pref is now
4802 -- attached to a node with no ancestor. Attach to tree
4803 -- even if it is to be rewritten below.
4804
4805 Set_Parent (Tst, Parent (N));
4806
4807 Tst :=
4808 Make_And_Then (Loc,
4809 Left_Opnd => Make_Range_Test,
4810 Right_Opnd => Tst);
4811 end if;
4812
4813 Rewrite (N, Tst);
4814
4815 -- Fortran convention booleans
4816
4817 -- For the very special case of Fortran convention booleans, the
4818 -- value is always valid, since it is an integer with the semantics
4819 -- that non-zero is true, and any value is permissible.
4820
4821 elsif Is_Boolean_Type (Ptyp)
4822 and then Convention (Ptyp) = Convention_Fortran
4823 then
4824 Rewrite (N, New_Occurrence_Of (Standard_True, Loc));
4825
4826 -- For biased representations, we will be doing an unchecked
aad6babd 4827 -- conversion without unbiasing the result. That means that the range
4828 -- test has to take this into account, and the proper form of the
4829 -- test is:
ee6ba406 4830
4831 -- Btyp!(Pref) < Btyp!(Ptyp'Range_Length)
4832
4833 elsif Has_Biased_Representation (Ptyp) then
4834 Btyp := RTE (RE_Unsigned_32);
4835 Rewrite (N,
4836 Make_Op_Lt (Loc,
4837 Left_Opnd =>
4838 Unchecked_Convert_To (Btyp, Duplicate_Subexpr (Pref)),
4839 Right_Opnd =>
4840 Unchecked_Convert_To (Btyp,
4841 Make_Attribute_Reference (Loc,
4842 Prefix => New_Occurrence_Of (Ptyp, Loc),
4843 Attribute_Name => Name_Range_Length))));
4844
4845 -- For all other scalar types, what we want logically is a
4846 -- range test:
4847
4848 -- X in type(X)'First .. type(X)'Last
4849
4850 -- But that's precisely what won't work because of possible
4851 -- unwanted optimization (and indeed the basic motivation for
5329ca64 4852 -- the Valid attribute is exactly that this test does not work!)
ee6ba406 4853 -- What will work is:
4854
4855 -- Btyp!(X) >= Btyp!(type(X)'First)
4856 -- and then
4857 -- Btyp!(X) <= Btyp!(type(X)'Last)
4858
4859 -- where Btyp is an integer type large enough to cover the full
4860 -- range of possible stored values (i.e. it is chosen on the basis
4861 -- of the size of the type, not the range of the values). We write
4862 -- this as two tests, rather than a range check, so that static
4863 -- evaluation will easily remove either or both of the checks if
4864 -- they can be -statically determined to be true (this happens
4865 -- when the type of X is static and the range extends to the full
4866 -- range of stored values).
4867
4868 -- Unsigned types. Note: it is safe to consider only whether the
4869 -- subtype is unsigned, since we will in that case be doing all
aad6babd 4870 -- unsigned comparisons based on the subtype range. Since we use the
4871 -- actual subtype object size, this is appropriate.
ee6ba406 4872
4873 -- For example, if we have
4874
4875 -- subtype x is integer range 1 .. 200;
4876 -- for x'Object_Size use 8;
4877
aad6babd 4878 -- Now the base type is signed, but objects of this type are bits
4879 -- unsigned, and doing an unsigned test of the range 1 to 200 is
4880 -- correct, even though a value greater than 127 looks signed to a
4881 -- signed comparison.
ee6ba406 4882
4883 elsif Is_Unsigned_Type (Ptyp) then
4884 if Esize (Ptyp) <= 32 then
4885 Btyp := RTE (RE_Unsigned_32);
4886 else
4887 Btyp := RTE (RE_Unsigned_64);
4888 end if;
4889
4890 Rewrite (N, Make_Range_Test);
4891
4892 -- Signed types
4893
4894 else
4895 if Esize (Ptyp) <= Esize (Standard_Integer) then
4896 Btyp := Standard_Integer;
4897 else
4898 Btyp := Universal_Integer;
4899 end if;
4900
4901 Rewrite (N, Make_Range_Test);
4902 end if;
4903
4904 Analyze_And_Resolve (N, Standard_Boolean);
9dfe12ae 4905 Validity_Checks_On := Save_Validity_Checks_On;
ee6ba406 4906 end Valid;
4907
4908 -----------
4909 -- Value --
4910 -----------
4911
4912 -- Value attribute is handled in separate unti Exp_Imgv
4913
4914 when Attribute_Value =>
4915 Exp_Imgv.Expand_Value_Attribute (N);
4916
4917 -----------------
4918 -- Value_Size --
4919 -----------------
4920
4921 -- The processing for Value_Size shares the processing for Size
4922
4923 -------------
4924 -- Version --
4925 -------------
4926
4927 -- The processing for Version shares the processing for Body_Version
4928
4929 ----------------
4930 -- Wide_Image --
4931 ----------------
4932
f0bf2ff3 4933 -- Wide_Image attribute is handled in separate unit Exp_Imgv
ee6ba406 4934
f0bf2ff3 4935 when Attribute_Wide_Image =>
4936 Exp_Imgv.Expand_Wide_Image_Attribute (N);
ee6ba406 4937
7189d17f 4938 ---------------------
4939 -- Wide_Wide_Image --
4940 ---------------------
4941
f0bf2ff3 4942 -- Wide_Wide_Image attribute is handled in separate unit Exp_Imgv
7189d17f 4943
f0bf2ff3 4944 when Attribute_Wide_Wide_Image =>
4945 Exp_Imgv.Expand_Wide_Wide_Image_Attribute (N);
7189d17f 4946
ee6ba406 4947 ----------------
4948 -- Wide_Value --
4949 ----------------
4950
4951 -- We expand typ'Wide_Value (X) into
4952
4953 -- typ'Value
4954 -- (Wide_String_To_String (X, Wide_Character_Encoding_Method))
4955
4956 -- Wide_String_To_String is a runtime function that converts its wide
4957 -- string argument to String, converting any non-translatable characters
4958 -- into appropriate escape sequences. This preserves the required
4959 -- semantics of Wide_Value in all cases, and results in a very simple
4960 -- implementation approach.
4961
7f8eb6ed 4962 -- Note: for this approach to be fully standard compliant for the cases
4963 -- where typ is Wide_Character and Wide_Wide_Character, the encoding
4964 -- method must cover the entire character range (e.g. UTF-8). But that
4965 -- is a reasonable requirement when dealing with encoded character
4966 -- sequences. Presumably if one of the restrictive encoding mechanisms
4967 -- is in use such as Shift-JIS, then characters that cannot be
4968 -- represented using this encoding will not appear in any case.
ee6ba406 4969
4970 when Attribute_Wide_Value => Wide_Value :
4971 begin
4972 Rewrite (N,
4973 Make_Attribute_Reference (Loc,
4974 Prefix => Pref,
4975 Attribute_Name => Name_Value,
4976
4977 Expressions => New_List (
4978 Make_Function_Call (Loc,
4979 Name =>
4980 New_Reference_To (RTE (RE_Wide_String_To_String), Loc),
4981
4982 Parameter_Associations => New_List (
4983 Relocate_Node (First (Exprs)),
4984 Make_Integer_Literal (Loc,
4985 Intval => Int (Wide_Character_Encoding_Method)))))));
4986
4987 Analyze_And_Resolve (N, Typ);
4988 end Wide_Value;
4989
7189d17f 4990 ---------------------
4991 -- Wide_Wide_Value --
4992 ---------------------
4993
4994 -- We expand typ'Wide_Value_Value (X) into
4995
4996 -- typ'Value
4997 -- (Wide_Wide_String_To_String (X, Wide_Character_Encoding_Method))
4998
4999 -- Wide_Wide_String_To_String is a runtime function that converts its
5000 -- wide string argument to String, converting any non-translatable
5001 -- characters into appropriate escape sequences. This preserves the
5002 -- required semantics of Wide_Wide_Value in all cases, and results in a
5003 -- very simple implementation approach.
5004
5005 -- It's not quite right where typ = Wide_Wide_Character, because the
5006 -- encoding method may not cover the whole character type ???
5007
5008 when Attribute_Wide_Wide_Value => Wide_Wide_Value :
5009 begin
5010 Rewrite (N,
5011 Make_Attribute_Reference (Loc,
5012 Prefix => Pref,
5013 Attribute_Name => Name_Value,
5014
5015 Expressions => New_List (
5016 Make_Function_Call (Loc,
5017 Name =>
5018 New_Reference_To (RTE (RE_Wide_Wide_String_To_String), Loc),
5019
5020 Parameter_Associations => New_List (
5021 Relocate_Node (First (Exprs)),
5022 Make_Integer_Literal (Loc,
5023 Intval => Int (Wide_Character_Encoding_Method)))))));
5024
5025 Analyze_And_Resolve (N, Typ);
5026 end Wide_Wide_Value;
5027
5028 ---------------------
5029 -- Wide_Wide_Width --
5030 ---------------------
5031
5032 -- Wide_Wide_Width attribute is handled in separate unit Exp_Imgv
5033
5034 when Attribute_Wide_Wide_Width =>
5035 Exp_Imgv.Expand_Width_Attribute (N, Wide_Wide);
5036
ee6ba406 5037 ----------------
5038 -- Wide_Width --
5039 ----------------
5040
5041 -- Wide_Width attribute is handled in separate unit Exp_Imgv
5042
5043 when Attribute_Wide_Width =>
7189d17f 5044 Exp_Imgv.Expand_Width_Attribute (N, Wide);
ee6ba406 5045
5046 -----------
5047 -- Width --
5048 -----------
5049
5050 -- Width attribute is handled in separate unit Exp_Imgv
5051
5052 when Attribute_Width =>
7189d17f 5053 Exp_Imgv.Expand_Width_Attribute (N, Normal);
ee6ba406 5054
5055 -----------
5056 -- Write --
5057 -----------
5058
5059 when Attribute_Write => Write : declare
5060 P_Type : constant Entity_Id := Entity (Pref);
5061 U_Type : constant Entity_Id := Underlying_Type (P_Type);
5062 Pname : Entity_Id;
5063 Decl : Node_Id;
5064 Prag : Node_Id;
5065 Arg3 : Node_Id;
5066 Wfunc : Node_Id;
5067
5068 begin
5069 -- If no underlying type, we have an error that will be diagnosed
5070 -- elsewhere, so here we just completely ignore the expansion.
5071
5072 if No (U_Type) then
5073 return;
5074 end if;
5075
5076 -- The simple case, if there is a TSS for Write, just call it
5077
9dfe12ae 5078 Pname := Find_Stream_Subprogram (P_Type, TSS_Stream_Write);
ee6ba406 5079
5080 if Present (Pname) then
5081 null;
5082
5083 else
5084 -- If there is a Stream_Convert pragma, use it, we rewrite
5085
5086 -- sourcetyp'Output (stream, Item)
5087
5088 -- as
5089
5090 -- strmtyp'Output (Stream, strmwrite (acttyp (Item)));
5091
aad6babd 5092 -- where strmwrite is the given Write function that converts an
5093 -- argument of type sourcetyp or a type acctyp, from which it is
5094 -- derived to type strmtyp. The conversion to acttyp is required
5095 -- for the derived case.
ee6ba406 5096
5245b786 5097 Prag := Get_Stream_Convert_Pragma (P_Type);
ee6ba406 5098
5099 if Present (Prag) then
5100 Arg3 :=
5101 Next (Next (First (Pragma_Argument_Associations (Prag))));
5102 Wfunc := Entity (Expression (Arg3));
5103
5104 Rewrite (N,
5105 Make_Attribute_Reference (Loc,
5106 Prefix => New_Occurrence_Of (Etype (Wfunc), Loc),
5107 Attribute_Name => Name_Output,
5108 Expressions => New_List (
5109 Relocate_Node (First (Exprs)),
5110 Make_Function_Call (Loc,
5111 Name => New_Occurrence_Of (Wfunc, Loc),
5112 Parameter_Associations => New_List (
83aa52b6 5113 OK_Convert_To (Etype (First_Formal (Wfunc)),
ee6ba406 5114 Relocate_Node (Next (First (Exprs)))))))));
5115
5116 Analyze (N);
5117 return;
5118
5119 -- For elementary types, we call the W_xxx routine directly
5120
5121 elsif Is_Elementary_Type (U_Type) then
5122 Rewrite (N, Build_Elementary_Write_Call (N));
5123 Analyze (N);
5124 return;
5125
5126 -- Array type case
5127
5128 elsif Is_Array_Type (U_Type) then
5129 Build_Array_Write_Procedure (N, U_Type, Decl, Pname);
5130 Compile_Stream_Body_In_Scope (N, Decl, U_Type, Check => False);
5131
5132 -- Tagged type case, use the primitive Write function. Note that
5133 -- this will dispatch in the class-wide case which is what we want
5134
5135 elsif Is_Tagged_Type (U_Type) then
9dfe12ae 5136 Pname := Find_Prim_Op (U_Type, TSS_Stream_Write);
ee6ba406 5137
5138 -- All other record type cases, including protected records.
5139 -- The latter only arise for expander generated code for
5140 -- handling shared passive partition access.
5141
5142 else
5143 pragma Assert
5144 (Is_Record_Type (U_Type) or else Is_Protected_Type (U_Type));
5145
00f91aef 5146 -- Ada 2005 (AI-216): Program_Error is raised when executing
5147 -- the default implementation of the Write attribute of an
99f2248e 5148 -- Unchecked_Union type. However, if the 'Write reference is
5149 -- within the generated Output stream procedure, Write outputs
5150 -- the components, and the default values of the discriminant
5151 -- are streamed by the Output procedure itself.
00f91aef 5152
99f2248e 5153 if Is_Unchecked_Union (Base_Type (U_Type))
5154 and not Is_TSS (Current_Scope, TSS_Stream_Output)
5155 then
00f91aef 5156 Insert_Action (N,
5157 Make_Raise_Program_Error (Loc,
5158 Reason => PE_Unchecked_Union_Restriction));
5159 end if;
5160
ee6ba406 5161 if Has_Discriminants (U_Type)
5162 and then Present
5163 (Discriminant_Default_Value (First_Discriminant (U_Type)))
5164 then
5165 Build_Mutable_Record_Write_Procedure
5166 (Loc, Base_Type (U_Type), Decl, Pname);
ee6ba406 5167 else
5168 Build_Record_Write_Procedure
5169 (Loc, Base_Type (U_Type), Decl, Pname);
5170 end if;
5171
5172 Insert_Action (N, Decl);
5173 end if;
5174 end if;
5175
5176 -- If we fall through, Pname is the procedure to be called
5177
5178 Rewrite_Stream_Proc_Call (Pname);
5179 end Write;
5180
d55c93e0 5181 -- Component_Size is handled by the back end, unless the component size
5182 -- is known at compile time, which is always true in the packed array
5183 -- case. It is important that the packed array case is handled in the
5184 -- front end (see Eval_Attribute) since the back end would otherwise get
5185 -- confused by the equivalent packed array type.
ee6ba406 5186
5187 when Attribute_Component_Size =>
5188 null;
5189
18a40e97 5190 -- The following attributes are handled by the back end (except that
5191 -- static cases have already been evaluated during semantic processing,
5192 -- but in any case the back end should not count on this). The one bit
5193 -- of special processing required is that these attributes typically
5194 -- generate conditionals in the code, so we need to check the relevant
5195 -- restriction.
5196
5197 when Attribute_Max |
5198 Attribute_Min =>
5199 Check_Restriction (No_Implicit_Conditionals, N);
ee6ba406 5200
18a40e97 5201 -- The following attributes are handled by the back end (except that
5202 -- static cases have already been evaluated during semantic processing,
5203 -- but in any case the back end should not count on this).
ee6ba406 5204
d55c93e0 5205 -- The back end also handles the non-class-wide cases of Size
ee6ba406 5206
5207 when Attribute_Bit_Order |
5208 Attribute_Code_Address |
5209 Attribute_Definite |
ee6ba406 5210 Attribute_Null_Parameter |
9dfe12ae 5211 Attribute_Passed_By_Reference |
5212 Attribute_Pool_Address =>
ee6ba406 5213 null;
5214
d55c93e0 5215 -- The following attributes are also handled by the back end, but return
5216 -- a universal integer result, so may need a conversion for checking
ee6ba406 5217 -- that the result is in range.
5218
5219 when Attribute_Aft |
ee6ba406 5220 Attribute_Bit |
5221 Attribute_Max_Size_In_Storage_Elements
5222 =>
5223 Apply_Universal_Integer_Attribute_Checks (N);
5224
5225 -- The following attributes should not appear at this stage, since they
5226 -- have already been handled by the analyzer (and properly rewritten
5227 -- with corresponding values or entities to represent the right values)
5228
5229 when Attribute_Abort_Signal |
5230 Attribute_Address_Size |
5231 Attribute_Base |
5232 Attribute_Class |
5233 Attribute_Default_Bit_Order |
5234 Attribute_Delta |
5235 Attribute_Denorm |
5236 Attribute_Digits |
5237 Attribute_Emax |
f947f061 5238 Attribute_Enabled |
ee6ba406 5239 Attribute_Epsilon |
f0bf2ff3 5240 Attribute_Fast_Math |
5c99c290 5241 Attribute_Has_Access_Values |
ee6ba406 5242 Attribute_Has_Discriminants |
d55c93e0 5243 Attribute_Has_Tagged_Values |
ee6ba406 5244 Attribute_Large |
5245 Attribute_Machine_Emax |
5246 Attribute_Machine_Emin |
5247 Attribute_Machine_Mantissa |
5248 Attribute_Machine_Overflows |
5249 Attribute_Machine_Radix |
5250 Attribute_Machine_Rounds |
ee6ba406 5251 Attribute_Maximum_Alignment |
5252 Attribute_Model_Emin |
5253 Attribute_Model_Epsilon |
5254 Attribute_Model_Mantissa |
5255 Attribute_Model_Small |
5256 Attribute_Modulus |
5257 Attribute_Partition_ID |
5258 Attribute_Range |
5259 Attribute_Safe_Emax |
5260 Attribute_Safe_First |
5261 Attribute_Safe_Large |
5262 Attribute_Safe_Last |
5263 Attribute_Safe_Small |
5264 Attribute_Scale |
5265 Attribute_Signed_Zeros |
5266 Attribute_Small |
5267 Attribute_Storage_Unit |
7f8eb6ed 5268 Attribute_Stub_Type |
9dfe12ae 5269 Attribute_Target_Name |
ee6ba406 5270 Attribute_Type_Class |
9dfe12ae 5271 Attribute_Unconstrained_Array |
ee6ba406 5272 Attribute_Universal_Literal_String |
5273 Attribute_Wchar_T_Size |
5274 Attribute_Word_Size =>
5275
5276 raise Program_Error;
5277
5278 -- The Asm_Input and Asm_Output attributes are not expanded at this
d55c93e0 5279 -- stage, but will be eliminated in the expansion of the Asm call, see
5280 -- Exp_Intr for details. So the back end will never see these either.
ee6ba406 5281
5282 when Attribute_Asm_Input |
5283 Attribute_Asm_Output =>
5284
5285 null;
5286
5287 end case;
5288
9dfe12ae 5289 exception
5290 when RE_Not_Available =>
5291 return;
ee6ba406 5292 end Expand_N_Attribute_Reference;
5293
5294 ----------------------
5295 -- Expand_Pred_Succ --
5296 ----------------------
5297
5298 -- For typ'Pred (exp), we generate the check
5299
5300 -- [constraint_error when exp = typ'Base'First]
5301
5302 -- Similarly, for typ'Succ (exp), we generate the check
5303
5304 -- [constraint_error when exp = typ'Base'Last]
5305
5306 -- These checks are not generated for modular types, since the proper
5307 -- semantics for Succ and Pred on modular types is to wrap, not raise CE.
5308
5309 procedure Expand_Pred_Succ (N : Node_Id) is
5310 Loc : constant Source_Ptr := Sloc (N);
5311 Cnam : Name_Id;
5312
5313 begin
5314 if Attribute_Name (N) = Name_Pred then
5315 Cnam := Name_First;
5316 else
5317 Cnam := Name_Last;
5318 end if;
5319
5320 Insert_Action (N,
5321 Make_Raise_Constraint_Error (Loc,
5322 Condition =>
5323 Make_Op_Eq (Loc,
9dfe12ae 5324 Left_Opnd =>
5325 Duplicate_Subexpr_Move_Checks (First (Expressions (N))),
ee6ba406 5326 Right_Opnd =>
5327 Make_Attribute_Reference (Loc,
5328 Prefix =>
5329 New_Reference_To (Base_Type (Etype (Prefix (N))), Loc),
f15731c4 5330 Attribute_Name => Cnam)),
5331 Reason => CE_Overflow_Check_Failed));
ee6ba406 5332 end Expand_Pred_Succ;
5333
1550b445 5334 -------------------
5335 -- Find_Fat_Info --
5336 -------------------
5337
5338 procedure Find_Fat_Info
5339 (T : Entity_Id;
5340 Fat_Type : out Entity_Id;
5341 Fat_Pkg : out RE_Id)
5342 is
5343 Btyp : constant Entity_Id := Base_Type (T);
5344 Rtyp : constant Entity_Id := Root_Type (T);
5345 Digs : constant Nat := UI_To_Int (Digits_Value (Btyp));
5346
5347 begin
5348 -- If the base type is VAX float, then get appropriate VAX float type
5349
5350 if Vax_Float (Btyp) then
5351 case Digs is
5352 when 6 =>
5353 Fat_Type := RTE (RE_Fat_VAX_F);
5354 Fat_Pkg := RE_Attr_VAX_F_Float;
5355
5356 when 9 =>
5357 Fat_Type := RTE (RE_Fat_VAX_D);
5358 Fat_Pkg := RE_Attr_VAX_D_Float;
5359
5360 when 15 =>
5361 Fat_Type := RTE (RE_Fat_VAX_G);
5362 Fat_Pkg := RE_Attr_VAX_G_Float;
5363
5364 when others =>
5365 raise Program_Error;
5366 end case;
5367
5368 -- If root type is VAX float, this is the case where the library has
5369 -- been recompiled in VAX float mode, and we have an IEEE float type.
5370 -- This is when we use the special IEEE Fat packages.
5371
5372 elsif Vax_Float (Rtyp) then
5373 case Digs is
5374 when 6 =>
5375 Fat_Type := RTE (RE_Fat_IEEE_Short);
5376 Fat_Pkg := RE_Attr_IEEE_Short;
5377
5378 when 15 =>
5379 Fat_Type := RTE (RE_Fat_IEEE_Long);
5380 Fat_Pkg := RE_Attr_IEEE_Long;
5381
5382 when others =>
5383 raise Program_Error;
5384 end case;
5385
5386 -- If neither the base type nor the root type is VAX_Float then VAX
5387 -- float is out of the picture, and we can just use the root type.
5388
5389 else
5390 Fat_Type := Rtyp;
5391
5392 if Fat_Type = Standard_Short_Float then
5393 Fat_Pkg := RE_Attr_Short_Float;
7f8eb6ed 5394
1550b445 5395 elsif Fat_Type = Standard_Float then
5396 Fat_Pkg := RE_Attr_Float;
7f8eb6ed 5397
1550b445 5398 elsif Fat_Type = Standard_Long_Float then
5399 Fat_Pkg := RE_Attr_Long_Float;
7f8eb6ed 5400
1550b445 5401 elsif Fat_Type = Standard_Long_Long_Float then
5402 Fat_Pkg := RE_Attr_Long_Long_Float;
7f8eb6ed 5403
5404 -- Universal real (which is its own root type) is treated as being
5405 -- equivalent to Standard.Long_Long_Float, since it is defined to
5406 -- have the same precision as the longest Float type.
5407
5408 elsif Fat_Type = Universal_Real then
5409 Fat_Type := Standard_Long_Long_Float;
5410 Fat_Pkg := RE_Attr_Long_Long_Float;
5411
1550b445 5412 else
5413 raise Program_Error;
5414 end if;
5415 end if;
5416 end Find_Fat_Info;
5417
9dfe12ae 5418 ----------------------------
5419 -- Find_Stream_Subprogram --
5420 ----------------------------
5421
5422 function Find_Stream_Subprogram
5423 (Typ : Entity_Id;
aad6babd 5424 Nam : TSS_Name_Type) return Entity_Id
5425 is
8667b0b2 5426 Base_Typ : constant Entity_Id := Base_Type (Typ);
5427 Ent : constant Entity_Id := TSS (Typ, Nam);
d55c93e0 5428
9dfe12ae 5429 begin
aad6babd 5430 if Present (Ent) then
5431 return Ent;
5432 end if;
5433
d55c93e0 5434 -- Stream attributes for strings are expanded into library calls. The
5435 -- following checks are disabled when the run-time is not available or
5436 -- when compiling predefined types due to bootstrap issues. As a result,
5437 -- the compiler will generate in-place stream routines for string types
5438 -- that appear in GNAT's library, but will generate calls via rtsfind
5439 -- to library routines for user code.
5440 -- ??? For now, disable this code for JVM, since this generates a
5441 -- VerifyError exception at run-time on e.g. c330001.
5442 -- This is disabled for AAMP, to avoid making dependences on files not
5443 -- supported in the AAMP library (such as s-fileio.adb).
5444
5445 if VM_Target /= JVM_Target
5446 and then not AAMP_On_Target
5447 and then
5448 not Is_Predefined_File_Name (Unit_File_Name (Current_Sem_Unit))
5449 then
d55c93e0 5450 -- String as defined in package Ada
5451
8667b0b2 5452 if Base_Typ = Standard_String then
b9f24e67 5453 if Restriction_Active (No_Stream_Optimizations) then
5454 if Nam = TSS_Stream_Input then
5455 return RTE (RE_String_Input);
5456
5457 elsif Nam = TSS_Stream_Output then
5458 return RTE (RE_String_Output);
5459
5460 elsif Nam = TSS_Stream_Read then
5461 return RTE (RE_String_Read);
d55c93e0 5462
b9f24e67 5463 else pragma Assert (Nam = TSS_Stream_Write);
5464 return RTE (RE_String_Write);
5465 end if;
5466
5467 else
5468 if Nam = TSS_Stream_Input then
5469 return RTE (RE_String_Input_Blk_IO);
d55c93e0 5470
b9f24e67 5471 elsif Nam = TSS_Stream_Output then
5472 return RTE (RE_String_Output_Blk_IO);
d55c93e0 5473
b9f24e67 5474 elsif Nam = TSS_Stream_Read then
5475 return RTE (RE_String_Read_Blk_IO);
5476
5477 else pragma Assert (Nam = TSS_Stream_Write);
5478 return RTE (RE_String_Write_Blk_IO);
5479 end if;
d55c93e0 5480 end if;
5481
5482 -- Wide_String as defined in package Ada
5483
8667b0b2 5484 elsif Base_Typ = Standard_Wide_String then
b9f24e67 5485 if Restriction_Active (No_Stream_Optimizations) then
5486 if Nam = TSS_Stream_Input then
5487 return RTE (RE_Wide_String_Input);
5488
5489 elsif Nam = TSS_Stream_Output then
5490 return RTE (RE_Wide_String_Output);
5491
5492 elsif Nam = TSS_Stream_Read then
5493 return RTE (RE_Wide_String_Read);
5494
5495 else pragma Assert (Nam = TSS_Stream_Write);
5496 return RTE (RE_Wide_String_Write);
5497 end if;
5498
5499 else
5500 if Nam = TSS_Stream_Input then
5501 return RTE (RE_Wide_String_Input_Blk_IO);
d55c93e0 5502
b9f24e67 5503 elsif Nam = TSS_Stream_Output then
5504 return RTE (RE_Wide_String_Output_Blk_IO);
d55c93e0 5505
b9f24e67 5506 elsif Nam = TSS_Stream_Read then
5507 return RTE (RE_Wide_String_Read_Blk_IO);
d55c93e0 5508
b9f24e67 5509 else pragma Assert (Nam = TSS_Stream_Write);
5510 return RTE (RE_Wide_String_Write_Blk_IO);
5511 end if;
d55c93e0 5512 end if;
5513
5514 -- Wide_Wide_String as defined in package Ada
5515
8667b0b2 5516 elsif Base_Typ = Standard_Wide_Wide_String then
b9f24e67 5517 if Restriction_Active (No_Stream_Optimizations) then
5518 if Nam = TSS_Stream_Input then
5519 return RTE (RE_Wide_Wide_String_Input);
5520
5521 elsif Nam = TSS_Stream_Output then
5522 return RTE (RE_Wide_Wide_String_Output);
d55c93e0 5523
b9f24e67 5524 elsif Nam = TSS_Stream_Read then
5525 return RTE (RE_Wide_Wide_String_Read);
d55c93e0 5526
b9f24e67 5527 else pragma Assert (Nam = TSS_Stream_Write);
5528 return RTE (RE_Wide_Wide_String_Write);
5529 end if;
d55c93e0 5530
b9f24e67 5531 else
5532 if Nam = TSS_Stream_Input then
5533 return RTE (RE_Wide_Wide_String_Input_Blk_IO);
5534
5535 elsif Nam = TSS_Stream_Output then
5536 return RTE (RE_Wide_Wide_String_Output_Blk_IO);
5537
5538 elsif Nam = TSS_Stream_Read then
5539 return RTE (RE_Wide_Wide_String_Read_Blk_IO);
5540
5541 else pragma Assert (Nam = TSS_Stream_Write);
5542 return RTE (RE_Wide_Wide_String_Write_Blk_IO);
5543 end if;
d55c93e0 5544 end if;
5545 end if;
5546 end if;
5547
9dfe12ae 5548 if Is_Tagged_Type (Typ)
5549 and then Is_Derived_Type (Typ)
5550 then
5551 return Find_Prim_Op (Typ, Nam);
5552 else
5553 return Find_Inherited_TSS (Typ, Nam);
5554 end if;
5555 end Find_Stream_Subprogram;
5556
ee6ba406 5557 -----------------------
5558 -- Get_Index_Subtype --
5559 -----------------------
5560
5561 function Get_Index_Subtype (N : Node_Id) return Node_Id is
5562 P_Type : Entity_Id := Etype (Prefix (N));
5563 Indx : Node_Id;
5564 J : Int;
5565
5566 begin
5567 if Is_Access_Type (P_Type) then
5568 P_Type := Designated_Type (P_Type);
5569 end if;
5570
5571 if No (Expressions (N)) then
5572 J := 1;
5573 else
5574 J := UI_To_Int (Expr_Value (First (Expressions (N))));
5575 end if;
5576
5577 Indx := First_Index (P_Type);
5578 while J > 1 loop
5579 Next_Index (Indx);
5580 J := J - 1;
5581 end loop;
5582
5583 return Etype (Indx);
5584 end Get_Index_Subtype;
5585
5245b786 5586 -------------------------------
5587 -- Get_Stream_Convert_Pragma --
5588 -------------------------------
5589
5590 function Get_Stream_Convert_Pragma (T : Entity_Id) return Node_Id is
5591 Typ : Entity_Id;
5592 N : Node_Id;
5593
5594 begin
5595 -- Note: we cannot use Get_Rep_Pragma here because of the peculiarity
5596 -- that a stream convert pragma for a tagged type is not inherited from
5597 -- its parent. Probably what is wrong here is that it is basically
5598 -- incorrect to consider a stream convert pragma to be a representation
5599 -- pragma at all ???
5600
5601 N := First_Rep_Item (Implementation_Base_Type (T));
5602 while Present (N) loop
4c06b9d2 5603 if Nkind (N) = N_Pragma
5604 and then Pragma_Name (N) = Name_Stream_Convert
5605 then
5245b786 5606 -- For tagged types this pragma is not inherited, so we
5607 -- must verify that it is defined for the given type and
5608 -- not an ancestor.
5609
5610 Typ :=
5611 Entity (Expression (First (Pragma_Argument_Associations (N))));
5612
5613 if not Is_Tagged_Type (T)
5614 or else T = Typ
5615 or else (Is_Private_Type (Typ) and then T = Full_View (Typ))
5616 then
5617 return N;
5618 end if;
5619 end if;
5620
5621 Next_Rep_Item (N);
5622 end loop;
5623
5624 return Empty;
5625 end Get_Stream_Convert_Pragma;
5626
ee6ba406 5627 ---------------------------------
5628 -- Is_Constrained_Packed_Array --
5629 ---------------------------------
5630
5631 function Is_Constrained_Packed_Array (Typ : Entity_Id) return Boolean is
5632 Arr : Entity_Id := Typ;
5633
5634 begin
5635 if Is_Access_Type (Arr) then
5636 Arr := Designated_Type (Arr);
5637 end if;
5638
5639 return Is_Array_Type (Arr)
5640 and then Is_Constrained (Arr)
5641 and then Present (Packed_Array_Type (Arr));
5642 end Is_Constrained_Packed_Array;
5643
99f2248e 5644 ----------------------------------------
5645 -- Is_Inline_Floating_Point_Attribute --
5646 ----------------------------------------
5647
5648 function Is_Inline_Floating_Point_Attribute (N : Node_Id) return Boolean is
5649 Id : constant Attribute_Id := Get_Attribute_Id (Attribute_Name (N));
5650
5651 begin
5652 if Nkind (Parent (N)) /= N_Type_Conversion
5653 or else not Is_Integer_Type (Etype (Parent (N)))
5654 then
5655 return False;
5656 end if;
5657
5658 -- Should also support 'Machine_Rounding and 'Unbiased_Rounding, but
5659 -- required back end support has not been implemented yet ???
5660
5661 return Id = Attribute_Truncation;
5662 end Is_Inline_Floating_Point_Attribute;
5663
ee6ba406 5664end Exp_Attr;
Mirror of https://gcc.gnu.org/git/gcc.git