1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
11 -- Copyright (C) 1992-2001 Free Software Foundation, Inc. --
13 -- GNAT is free software; you can redistribute it and/or modify it under --
14 -- terms of the GNU General Public License as published by the Free Soft- --
15 -- ware Foundation; either version 2, or (at your option) any later ver- --
16 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
17 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
18 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
19 -- for more details. You should have received a copy of the GNU General --
20 -- Public License distributed with GNAT; see file COPYING. If not, write --
21 -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
22 -- MA 02111-1307, USA. --
24 -- GNAT was originally developed by the GNAT team at New York University. --
25 -- It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). --
27 ------------------------------------------------------------------------------
29 with Atree; use Atree;
30 with Casing; use Casing;
31 with Einfo; use Einfo;
32 with Errout; use Errout;
33 with Exp_Ch11; use Exp_Ch11;
34 with Exp_Tss; use Exp_Tss;
35 with Exp_Util; use Exp_Util;
36 with Expander; use Expander;
37 with Namet; use Namet;
38 with Nlists; use Nlists;
39 with Nmake; use Nmake;
41 with Rtsfind; use Rtsfind;
43 with Sem_Eval; use Sem_Eval;
44 with Sem_Res; use Sem_Res;
45 with Sem_Util; use Sem_Util;
46 with Sinfo; use Sinfo;
47 with Sinput; use Sinput;
48 with Snames; use Snames;
49 with Stringt; use Stringt;
50 with Stand; use Stand;
51 with Tbuild; use Tbuild;
52 with Uintp; use Uintp;
54 package body Exp_Prag is
56 -----------------------
57 -- Local Subprograms --
58 -----------------------
60 function Arg1 (N : Node_Id) return Node_Id;
61 function Arg2 (N : Node_Id) return Node_Id;
62 function Arg3 (N : Node_Id) return Node_Id;
63 -- Obtain specified Pragma_Argument_Association
65 procedure Expand_Pragma_Abort_Defer (N : Node_Id);
66 procedure Expand_Pragma_Assert (N : Node_Id);
67 procedure Expand_Pragma_Import (N : Node_Id);
68 procedure Expand_Pragma_Import_Export_Exception (N : Node_Id);
69 procedure Expand_Pragma_Inspection_Point (N : Node_Id);
70 procedure Expand_Pragma_Interrupt_Priority (N : Node_Id);
76 function Arg1 (N : Node_Id) return Node_Id is
78 return First (Pragma_Argument_Associations (N));
81 function Arg2 (N : Node_Id) return Node_Id is
83 return Next (Arg1 (N));
86 function Arg3 (N : Node_Id) return Node_Id is
88 return Next (Arg2 (N));
95 procedure Expand_N_Pragma (N : Node_Id) is
97 -- Note: we may have a pragma whose chars field is not a
98 -- recognized pragma, and we must ignore it at this stage.
100 if Is_Pragma_Name (Chars (N)) then
101 case Get_Pragma_Id (Chars (N)) is
103 -- Pragmas requiring special expander action
105 when Pragma_Abort_Defer =>
106 Expand_Pragma_Abort_Defer (N);
108 when Pragma_Assert =>
109 Expand_Pragma_Assert (N);
111 when Pragma_Export_Exception =>
112 Expand_Pragma_Import_Export_Exception (N);
114 when Pragma_Import =>
115 Expand_Pragma_Import (N);
117 when Pragma_Import_Exception =>
118 Expand_Pragma_Import_Export_Exception (N);
120 when Pragma_Inspection_Point =>
121 Expand_Pragma_Inspection_Point (N);
123 when Pragma_Interrupt_Priority =>
124 Expand_Pragma_Interrupt_Priority (N);
126 -- All other pragmas need no expander action
134 -------------------------------
135 -- Expand_Pragma_Abort_Defer --
136 -------------------------------
138 -- An Abort_Defer pragma appears as the first statement in a handled
139 -- statement sequence (right after the begin). It defers aborts for
140 -- the entire statement sequence, but not for any declarations or
141 -- handlers (if any) associated with this statement sequence.
143 -- The transformation is to transform
145 -- pragma Abort_Defer;
154 -- when all others =>
155 -- Abort_Undefer.all;
158 -- Abort_Undefer_Direct;
161 procedure Expand_Pragma_Abort_Defer (N : Node_Id) is
162 Loc : constant Source_Ptr := Sloc (N);
166 Blk : constant Entity_Id :=
167 New_Internal_Entity (E_Block, Current_Scope, Sloc (N), 'B');
170 Stms := New_List (Build_Runtime_Call (Loc, RE_Abort_Defer));
173 Stm := Remove_Next (N);
179 Make_Handled_Sequence_Of_Statements (Loc,
182 New_Occurrence_Of (RTE (RE_Abort_Undefer_Direct), Loc));
185 Make_Block_Statement (Loc,
186 Handled_Statement_Sequence => HSS));
188 Set_Scope (Blk, Current_Scope);
189 Set_Etype (Blk, Standard_Void_Type);
190 Set_Identifier (N, New_Occurrence_Of (Blk, Sloc (N)));
191 Expand_At_End_Handler (HSS, Blk);
193 end Expand_Pragma_Abort_Defer;
195 --------------------------
196 -- Expand_Pragma_Assert --
197 --------------------------
199 procedure Expand_Pragma_Assert (N : Node_Id) is
200 Loc : constant Source_Ptr := Sloc (N);
201 Cond : constant Node_Id := Expression (Arg1 (N));
205 -- We already know that assertions are enabled, because otherwise
206 -- the semantic pass dealt with rewriting the assertion (see Sem_Prag)
208 pragma Assert (Assertions_Enabled);
210 -- Since assertions are on, we rewrite the pragma with its
211 -- corresponding if statement, and then analyze the statement
212 -- The expansion transforms:
214 -- pragma Assert (condition [,message]);
218 -- if not condition then
219 -- System.Assertions.Raise_Assert_Failure (Str);
222 -- where Str is the message if one is present, or the default of
223 -- file:line if no message is given.
225 -- First, we need to prepare the character literal
227 if Present (Arg2 (N)) then
228 Msg := Strval (Expr_Value_S (Expression (Arg2 (N))));
230 Build_Location_String (Loc);
231 Msg := String_From_Name_Buffer;
234 -- Now generate the if statement. Note that we consider this to be
235 -- an explicit conditional in the source, not an implicit if, so we
236 -- do not call Make_Implicit_If_Statement.
239 Make_If_Statement (Loc,
243 Then_Statements => New_List (
244 Make_Procedure_Call_Statement (Loc,
246 New_Reference_To (RTE (RE_Raise_Assert_Failure), Loc),
247 Parameter_Associations => New_List (
248 Make_String_Literal (Loc, Msg))))));
252 -- If new condition is always false, give a warning
254 if Nkind (N) = N_Procedure_Call_Statement
255 and then Is_RTE (Entity (Name (N)), RE_Raise_Assert_Failure)
257 -- If original condition was a Standard.False, we assume
258 -- that this is indeed intented to raise assert error
259 -- and no warning is required.
261 if Is_Entity_Name (Original_Node (Cond))
262 and then Entity (Original_Node (Cond)) = Standard_False
266 Error_Msg_N ("?assertion will fail at run-time", N);
269 end Expand_Pragma_Assert;
271 --------------------------
272 -- Expand_Pragma_Import --
273 --------------------------
275 -- When applied to a variable, the default initialization must not be
276 -- done. As it is already done when the pragma is found, we just get rid
277 -- of the call the initialization procedure which followed the object
280 -- We can't use the freezing mechanism for this purpose, since we
281 -- have to elaborate the initialization expression when it is first
282 -- seen (i.e. this elaboration cannot be deferred to the freeze point).
284 procedure Expand_Pragma_Import (N : Node_Id) is
285 Def_Id : constant Entity_Id := Entity (Expression (Arg2 (N)));
290 if Ekind (Def_Id) = E_Variable then
291 Typ := Etype (Def_Id);
292 After_Def := Next (Parent (Def_Id));
294 if Has_Non_Null_Base_Init_Proc (Typ)
295 and then Nkind (After_Def) = N_Procedure_Call_Statement
296 and then Is_Entity_Name (Name (After_Def))
297 and then Entity (Name (After_Def)) = Base_Init_Proc (Typ)
301 elsif Is_Access_Type (Typ) then
302 Set_Expression (Parent (Def_Id), Empty);
305 end Expand_Pragma_Import;
307 -------------------------------------------
308 -- Expand_Pragma_Import_Export_Exception --
309 -------------------------------------------
311 -- For a VMS exception fix up the language field with "VMS"
312 -- instead of "Ada" (gigi needs this), create a constant that will be the
313 -- value of the VMS condition code and stuff the Interface_Name field
314 -- with the unexpanded name of the exception (if not already set).
315 -- For a Ada exception, just stuff the Interface_Name field
316 -- with the unexpanded name of the exception (if not already set).
318 procedure Expand_Pragma_Import_Export_Exception (N : Node_Id) is
319 Id : constant Entity_Id := Entity (Expression (Arg1 (N)));
320 Call : constant Node_Id := Register_Exception_Call (Id);
321 Loc : constant Source_Ptr := Sloc (N);
323 if Present (Call) then
325 Excep_Internal : constant Node_Id :=
326 Make_Defining_Identifier
327 (Loc, New_Internal_Name ('V'));
328 Export_Pragma : Node_Id;
329 Excep_Alias : Node_Id;
330 Excep_Object : Node_Id;
331 Excep_Image : String_Id;
338 if Present (Interface_Name (Id)) then
339 Excep_Image := Strval (Interface_Name (Id));
341 Get_Name_String (Chars (Id));
343 Excep_Image := String_From_Name_Buffer;
346 Exdata := Component_Associations (Expression (Parent (Id)));
348 if Is_VMS_Exception (Id) then
350 Lang1 := Next (First (Exdata));
351 Lang2 := Next (Lang1);
352 Lang3 := Next (Lang2);
354 Rewrite (Expression (Lang1),
355 Make_Character_Literal (Loc, Name_uV, Get_Char_Code ('V')));
356 Analyze (Expression (Lang1));
358 Rewrite (Expression (Lang2),
359 Make_Character_Literal (Loc, Name_uM, Get_Char_Code ('M')));
360 Analyze (Expression (Lang2));
362 Rewrite (Expression (Lang3),
363 Make_Character_Literal (Loc, Name_uS, Get_Char_Code ('S')));
364 Analyze (Expression (Lang3));
366 if Exception_Code (Id) /= No_Uint then
367 Code := Make_Integer_Literal (Loc, Exception_Code (Id));
370 Make_Object_Declaration (Loc,
371 Defining_Identifier => Excep_Internal,
373 New_Reference_To (Standard_Integer, Loc));
375 Insert_Action (N, Excep_Object);
376 Analyze (Excep_Object);
379 Store_String_Int (UI_To_Int (Exception_Code (Id)) / 8 * 8);
386 (Make_Pragma_Argument_Association
389 New_Reference_To (Excep_Internal, Loc)),
390 Make_Pragma_Argument_Association
395 Strval => End_String))));
397 Insert_Action (N, Excep_Alias);
398 Analyze (Excep_Alias);
405 (Make_Pragma_Argument_Association
407 Expression => Make_Identifier (Loc, Name_C)),
408 Make_Pragma_Argument_Association
411 New_Reference_To (Excep_Internal, Loc)),
412 Make_Pragma_Argument_Association
417 Strval => Excep_Image)),
418 Make_Pragma_Argument_Association
423 Strval => Excep_Image))));
425 Insert_Action (N, Export_Pragma);
426 Analyze (Export_Pragma);
430 Unchecked_Convert_To (Standard_Integer,
431 Make_Function_Call (Loc,
433 New_Reference_To (RTE (RE_Import_Value), Loc),
434 Parameter_Associations => New_List
435 (Make_String_Literal (Loc,
436 Strval => Excep_Image))));
440 Make_Procedure_Call_Statement (Loc,
441 Name => New_Reference_To
442 (RTE (RE_Register_VMS_Exception), Loc),
443 Parameter_Associations => New_List (Code)));
445 Analyze_And_Resolve (Code, Standard_Integer);
450 if not Present (Interface_Name (Id)) then
451 Set_Interface_Name (Id,
454 Strval => Excep_Image));
458 end Expand_Pragma_Import_Export_Exception;
460 ------------------------------------
461 -- Expand_Pragma_Inspection_Point --
462 ------------------------------------
464 -- If no argument is given, then we supply a default argument list that
465 -- includes all objects declared at the source level in all subprograms
466 -- that enclose the inspection point pragma.
468 procedure Expand_Pragma_Inspection_Point (N : Node_Id) is
469 Loc : constant Source_Ptr := Sloc (N);
476 if No (Pragma_Argument_Associations (N)) then
480 while S /= Standard_Standard loop
481 E := First_Entity (S);
482 while Present (E) loop
483 if Comes_From_Source (E)
484 and then Is_Object (E)
485 and then not Is_Entry_Formal (E)
486 and then Ekind (E) /= E_Component
487 and then Ekind (E) /= E_Discriminant
488 and then Ekind (E) /= E_Generic_In_Parameter
489 and then Ekind (E) /= E_Generic_In_Out_Parameter
492 Make_Pragma_Argument_Association (Loc,
493 Expression => New_Occurrence_Of (E, Loc)));
502 Set_Pragma_Argument_Associations (N, A);
505 -- Expand the arguments of the pragma. Expanding an entity reference
506 -- is a noop, except in a protected operation, where a reference may
507 -- have to be transformed into a reference to the corresponding prival.
508 -- Are there other pragmas that may require this ???
510 Assoc := First (Pragma_Argument_Associations (N));
512 while Present (Assoc) loop
513 Expand (Expression (Assoc));
516 end Expand_Pragma_Inspection_Point;
518 --------------------------------------
519 -- Expand_Pragma_Interrupt_Priority --
520 --------------------------------------
522 -- Supply default argument if none exists (System.Interrupt_Priority'Last)
524 procedure Expand_Pragma_Interrupt_Priority (N : Node_Id) is
525 Loc : constant Source_Ptr := Sloc (N);
528 if No (Pragma_Argument_Associations (N)) then
529 Set_Pragma_Argument_Associations (N, New_List (
530 Make_Pragma_Argument_Association (Loc,
532 Make_Attribute_Reference (Loc,
534 New_Occurrence_Of (RTE (RE_Interrupt_Priority), Loc),
535 Attribute_Name => Name_Last))));
537 end Expand_Pragma_Interrupt_Priority;