1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2007, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 2, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING. If not, write --
19 -- to the Free Software Foundation, 51 Franklin Street, Fifth Floor, --
20 -- Boston, MA 02110-1301, USA. --
22 -- GNAT was originally developed by the GNAT team at New York University. --
23 -- Extensive contributions were provided by Ada Core Technologies Inc. --
25 ------------------------------------------------------------------------------
27 with Atree; use Atree;
28 with Checks; use Checks;
29 with Einfo; use Einfo;
30 with Elists; use Elists;
31 with Errout; use Errout;
32 with Exp_Atag; use Exp_Atag;
33 with Exp_Ch4; use Exp_Ch4;
34 with Exp_Ch7; use Exp_Ch7;
35 with Exp_Ch11; use Exp_Ch11;
36 with Exp_Code; use Exp_Code;
37 with Exp_Fixd; use Exp_Fixd;
38 with Exp_Util; use Exp_Util;
39 with Freeze; use Freeze;
40 with Namet; use Namet;
41 with Nmake; use Nmake;
42 with Nlists; use Nlists;
43 with Restrict; use Restrict;
44 with Rident; use Rident;
45 with Rtsfind; use Rtsfind;
47 with Sem_Eval; use Sem_Eval;
48 with Sem_Res; use Sem_Res;
49 with Sem_Util; use Sem_Util;
50 with Sinfo; use Sinfo;
51 with Sinput; use Sinput;
52 with Snames; use Snames;
53 with Stand; use Stand;
54 with Stringt; use Stringt;
55 with Tbuild; use Tbuild;
56 with Uintp; use Uintp;
57 with Urealp; use Urealp;
59 package body Exp_Intr is
61 -----------------------
62 -- Local Subprograms --
63 -----------------------
65 procedure Expand_Is_Negative (N : Node_Id);
66 -- Expand a call to the intrinsic Is_Negative function
68 procedure Expand_Dispatching_Constructor_Call (N : Node_Id);
69 -- Expand a call to an instantiation of Generic_Dispatching_Constructor
70 -- into a dispatching call to the actual subprogram associated with the
71 -- Constructor formal subprogram, passing it the Parameters actual of
72 -- the call to the instantiation and dispatching based on call's Tag
75 procedure Expand_Exception_Call (N : Node_Id; Ent : RE_Id);
76 -- Expand a call to Exception_Information/Message/Name. The first
77 -- parameter, N, is the node for the function call, and Ent is the
78 -- entity for the corresponding routine in the Ada.Exceptions package.
80 procedure Expand_Import_Call (N : Node_Id);
81 -- Expand a call to Import_Address/Longest_Integer/Value. The parameter
82 -- N is the node for the function call.
84 procedure Expand_Shift (N : Node_Id; E : Entity_Id; K : Node_Kind);
85 -- Expand an intrinsic shift operation, N and E are from the call to
86 -- Expand_Intrinsic_Call (call node and subprogram spec entity) and
87 -- K is the kind for the shift node
89 procedure Expand_Unc_Conversion (N : Node_Id; E : Entity_Id);
90 -- Expand a call to an instantiation of Unchecked_Convertion into a node
91 -- N_Unchecked_Type_Conversion.
93 procedure Expand_Unc_Deallocation (N : Node_Id);
94 -- Expand a call to an instantiation of Unchecked_Deallocation into a node
95 -- N_Free_Statement and appropriate context.
97 procedure Expand_To_Address (N : Node_Id);
98 procedure Expand_To_Pointer (N : Node_Id);
99 -- Expand a call to corresponding function, declared in an instance of
100 -- System.Addess_To_Access_Conversions.
102 procedure Expand_Source_Info (N : Node_Id; Nam : Name_Id);
103 -- Rewrite the node by the appropriate string or positive constant.
104 -- Nam can be one of the following:
105 -- Name_File - expand string that is the name of source file
106 -- Name_Line - expand integer line number
107 -- Name_Source_Location - expand string of form file:line
108 -- Name_Enclosing_Entity - expand string with name of enclosing entity
110 -----------------------------------------
111 -- Expand_Dispatching_Constructor_Call --
112 -----------------------------------------
114 -- Transform a call to an instantiation of Generic_Dispatching_Constructor
117 -- GDC_Instance (The_Tag, Parameters'Access)
119 -- to a class-wide conversion of a dispatching call to the actual
120 -- associated with the formal subprogram Construct, designating The_Tag
121 -- as the controlling tag of the call:
123 -- T'Class (Construct'Actual (Params)) -- Controlling tag is The_Tag
125 -- which will eventually be expanded to the following:
127 -- T'Class (The_Tag.all (Construct'Actual'Index).all (Params))
129 -- A class-wide membership test is also generated, preceding the call, to
130 -- ensure that the controlling tag denotes a type in T'Class.
132 procedure Expand_Dispatching_Constructor_Call (N : Node_Id) is
133 Loc : constant Source_Ptr := Sloc (N);
134 Tag_Arg : constant Node_Id := First_Actual (N);
135 Param_Arg : constant Node_Id := Next_Actual (Tag_Arg);
136 Subp_Decl : constant Node_Id := Parent (Parent (Entity (Name (N))));
137 Inst_Pkg : constant Node_Id := Parent (Subp_Decl);
138 Act_Rename : Node_Id;
139 Act_Constr : Entity_Id;
140 Result_Typ : Entity_Id;
141 Cnstr_Call : Node_Id;
144 -- The subprogram is the third actual in the instantiation, and is
145 -- retrieved from the corresponding renaming declaration. However,
146 -- freeze nodes may appear before, so we retrieve the declaration
147 -- with an explicit loop.
149 Act_Rename := First (Visible_Declarations (Inst_Pkg));
150 while Nkind (Act_Rename) /= N_Subprogram_Renaming_Declaration loop
154 Act_Constr := Entity (Name (Act_Rename));
155 Result_Typ := Class_Wide_Type (Etype (Act_Constr));
157 -- Ada 2005 (AI-251): If the result is an interface type, the function
158 -- returns a class-wide interface type (otherwise the resulting object
159 -- would be abstract!)
161 if Is_Interface (Etype (Act_Constr)) then
162 Set_Etype (Act_Constr, Result_Typ);
165 -- Create the call to the actual Constructor function
168 Make_Function_Call (Loc,
169 Name => New_Occurrence_Of (Act_Constr, Loc),
170 Parameter_Associations => New_List (Relocate_Node (Param_Arg)));
172 -- Establish its controlling tag from the tag passed to the instance
173 -- The tag may be given by a function call, in which case a temporary
174 -- should be generated now, to prevent out-of-order insertions during
175 -- the expansion of that call when stack-checking is enabled.
177 Remove_Side_Effects (Tag_Arg);
178 Set_Controlling_Argument (Cnstr_Call, Relocate_Node (Tag_Arg));
180 -- Rewrite and analyze the call to the instance as a class-wide
181 -- conversion of the call to the actual constructor.
183 Rewrite (N, Convert_To (Result_Typ, Cnstr_Call));
184 Analyze_And_Resolve (N, Etype (Act_Constr));
186 -- Do not generate a run-time check on the built object if tag
187 -- checks are suppressed for the result type.
189 if Tag_Checks_Suppressed (Etype (Result_Typ)) then
192 -- Generate a class-wide membership test to ensure that the call's tag
193 -- argument denotes a type within the class. We must keep separate the
194 -- case in which the Result_Type of the constructor function is a tagged
195 -- type from the case in which it is an abstract interface because the
196 -- run-time subprogram required to check these cases differ (and have
197 -- one difference in their parameters profile).
199 -- Call CW_Membership if the Result_Type is a tagged type to look for
200 -- the tag in the table of ancestor tags.
202 elsif not Is_Interface (Result_Typ) then
204 Make_Implicit_If_Statement (N,
207 Build_CW_Membership (Loc,
208 Obj_Tag_Node => Duplicate_Subexpr (Tag_Arg),
211 Node (First_Elmt (Access_Disp_Table (
212 Root_Type (Result_Typ)))), Loc))),
214 New_List (Make_Raise_Statement (Loc,
215 New_Occurrence_Of (RTE (RE_Tag_Error), Loc)))));
217 -- Call IW_Membership test if the Result_Type is an abstract interface
218 -- to look for the tag in the table of interface tags.
222 Make_Implicit_If_Statement (N,
225 Make_Function_Call (Loc,
226 Name => New_Occurrence_Of (RTE (RE_IW_Membership), Loc),
227 Parameter_Associations => New_List (
228 Make_Attribute_Reference (Loc,
229 Prefix => Duplicate_Subexpr (Tag_Arg),
230 Attribute_Name => Name_Address),
233 Node (First_Elmt (Access_Disp_Table (
234 Root_Type (Result_Typ)))), Loc)))),
237 Make_Raise_Statement (Loc,
238 Name => New_Occurrence_Of (RTE (RE_Tag_Error), Loc)))));
240 end Expand_Dispatching_Constructor_Call;
242 ---------------------------
243 -- Expand_Exception_Call --
244 ---------------------------
246 -- If the function call is not within an exception handler, then the call
247 -- is replaced by a null string. Otherwise the appropriate routine in
248 -- Ada.Exceptions is called passing the choice parameter specification
249 -- from the enclosing handler. If the enclosing handler lacks a choice
250 -- parameter, then one is supplied.
252 procedure Expand_Exception_Call (N : Node_Id; Ent : RE_Id) is
253 Loc : constant Source_Ptr := Sloc (N);
258 -- Climb up parents to see if we are in exception handler
262 -- Case of not in exception handler, replace by null string
266 Make_String_Literal (Loc,
270 -- Case of in exception handler
272 elsif Nkind (P) = N_Exception_Handler then
274 -- Handler cannot be used for a local raise, and furthermore, this
275 -- is a violation of the No_Exception_Propagation restriction.
277 Set_Local_Raise_Not_OK (P);
278 Check_Restriction (No_Exception_Propagation, N);
280 -- If no choice parameter present, then put one there. Note that
281 -- we do not need to put it on the entity chain, since no one will
282 -- be referencing it by normal visibility methods.
284 if No (Choice_Parameter (P)) then
285 E := Make_Defining_Identifier (Loc, New_Internal_Name ('E'));
286 Set_Choice_Parameter (P, E);
287 Set_Ekind (E, E_Variable);
288 Set_Etype (E, RTE (RE_Exception_Occurrence));
289 Set_Scope (E, Current_Scope);
293 Make_Function_Call (Loc,
294 Name => New_Occurrence_Of (RTE (Ent), Loc),
295 Parameter_Associations => New_List (
296 New_Occurrence_Of (Choice_Parameter (P), Loc))));
306 Analyze_And_Resolve (N, Standard_String);
307 end Expand_Exception_Call;
309 ------------------------
310 -- Expand_Import_Call --
311 ------------------------
313 -- The function call must have a static string as its argument. We create
314 -- a dummy variable which uses this string as the external name in an
315 -- Import pragma. The result is then obtained as the address of this
316 -- dummy variable, converted to the appropriate target type.
318 procedure Expand_Import_Call (N : Node_Id) is
319 Loc : constant Source_Ptr := Sloc (N);
320 Ent : constant Entity_Id := Entity (Name (N));
321 Str : constant Node_Id := First_Actual (N);
325 Dum := Make_Defining_Identifier (Loc, New_Internal_Name ('D'));
327 Insert_Actions (N, New_List (
328 Make_Object_Declaration (Loc,
329 Defining_Identifier => Dum,
331 New_Occurrence_Of (Standard_Character, Loc)),
334 Chars => Name_Import,
335 Pragma_Argument_Associations => New_List (
336 Make_Pragma_Argument_Association (Loc,
337 Expression => Make_Identifier (Loc, Name_Ada)),
339 Make_Pragma_Argument_Association (Loc,
340 Expression => Make_Identifier (Loc, Chars (Dum))),
342 Make_Pragma_Argument_Association (Loc,
343 Chars => Name_Link_Name,
344 Expression => Relocate_Node (Str))))));
347 Unchecked_Convert_To (Etype (Ent),
348 Make_Attribute_Reference (Loc,
349 Attribute_Name => Name_Address,
350 Prefix => Make_Identifier (Loc, Chars (Dum)))));
352 Analyze_And_Resolve (N, Etype (Ent));
353 end Expand_Import_Call;
355 ---------------------------
356 -- Expand_Intrinsic_Call --
357 ---------------------------
359 procedure Expand_Intrinsic_Call (N : Node_Id; E : Entity_Id) is
363 -- If the intrinsic subprogram is generic, gets its original name
365 if Present (Parent (E))
366 and then Present (Generic_Parent (Parent (E)))
368 Nam := Chars (Generic_Parent (Parent (E)));
373 if Nam = Name_Asm then
376 elsif Nam = Name_Divide then
377 Expand_Decimal_Divide_Call (N);
379 elsif Nam = Name_Exception_Information then
380 Expand_Exception_Call (N, RE_Exception_Information);
382 elsif Nam = Name_Exception_Message then
383 Expand_Exception_Call (N, RE_Exception_Message);
385 elsif Nam = Name_Exception_Name then
386 Expand_Exception_Call (N, RE_Exception_Name_Simple);
388 elsif Nam = Name_Generic_Dispatching_Constructor then
389 Expand_Dispatching_Constructor_Call (N);
391 elsif Nam = Name_Import_Address
393 Nam = Name_Import_Largest_Value
395 Nam = Name_Import_Value
397 Expand_Import_Call (N);
399 elsif Nam = Name_Is_Negative then
400 Expand_Is_Negative (N);
402 elsif Nam = Name_Rotate_Left then
403 Expand_Shift (N, E, N_Op_Rotate_Left);
405 elsif Nam = Name_Rotate_Right then
406 Expand_Shift (N, E, N_Op_Rotate_Right);
408 elsif Nam = Name_Shift_Left then
409 Expand_Shift (N, E, N_Op_Shift_Left);
411 elsif Nam = Name_Shift_Right then
412 Expand_Shift (N, E, N_Op_Shift_Right);
414 elsif Nam = Name_Shift_Right_Arithmetic then
415 Expand_Shift (N, E, N_Op_Shift_Right_Arithmetic);
417 elsif Nam = Name_Unchecked_Conversion then
418 Expand_Unc_Conversion (N, E);
420 elsif Nam = Name_Unchecked_Deallocation then
421 Expand_Unc_Deallocation (N);
423 elsif Nam = Name_To_Address then
424 Expand_To_Address (N);
426 elsif Nam = Name_To_Pointer then
427 Expand_To_Pointer (N);
429 elsif Nam = Name_File
430 or else Nam = Name_Line
431 or else Nam = Name_Source_Location
432 or else Nam = Name_Enclosing_Entity
434 Expand_Source_Info (N, Nam);
436 -- If we have a renaming, expand the call to the original operation,
437 -- which must itself be intrinsic, since renaming requires matching
438 -- conventions and this has already been checked.
440 elsif Present (Alias (E)) then
441 Expand_Intrinsic_Call (N, Alias (E));
443 -- The only other case is where an external name was specified,
444 -- since this is the only way that an otherwise unrecognized
445 -- name could escape the checking in Sem_Prag. Nothing needs
446 -- to be done in such a case, since we pass such a call to the
447 -- back end unchanged.
452 end Expand_Intrinsic_Call;
454 ------------------------
455 -- Expand_Is_Negative --
456 ------------------------
458 procedure Expand_Is_Negative (N : Node_Id) is
459 Loc : constant Source_Ptr := Sloc (N);
460 Opnd : constant Node_Id := Relocate_Node (First_Actual (N));
464 -- We replace the function call by the following expression
466 -- if Opnd < 0.0 then
469 -- if Opnd > 0.0 then
472 -- Float_Unsigned!(Float (Opnd)) /= 0
477 Make_Conditional_Expression (Loc,
478 Expressions => New_List (
480 Left_Opnd => Duplicate_Subexpr (Opnd),
481 Right_Opnd => Make_Real_Literal (Loc, Ureal_0)),
483 New_Occurrence_Of (Standard_True, Loc),
485 Make_Conditional_Expression (Loc,
486 Expressions => New_List (
488 Left_Opnd => Duplicate_Subexpr_No_Checks (Opnd),
489 Right_Opnd => Make_Real_Literal (Loc, Ureal_0)),
491 New_Occurrence_Of (Standard_False, Loc),
496 (RTE (RE_Float_Unsigned),
499 Duplicate_Subexpr_No_Checks (Opnd))),
501 Make_Integer_Literal (Loc, 0)))))));
503 Analyze_And_Resolve (N, Standard_Boolean);
504 end Expand_Is_Negative;
510 -- This procedure is used to convert a call to a shift function to the
511 -- corresponding operator node. This conversion is not done by the usual
512 -- circuit for converting calls to operator functions (e.g. "+"(1,2)) to
513 -- operator nodes, because shifts are not predefined operators.
515 -- As a result, whenever a shift is used in the source program, it will
516 -- remain as a call until converted by this routine to the operator node
517 -- form which Gigi is expecting to see.
519 -- Note: it is possible for the expander to generate shift operator nodes
520 -- directly, which will be analyzed in the normal manner by calling Analyze
521 -- and Resolve. Such shift operator nodes will not be seen by Expand_Shift.
523 procedure Expand_Shift (N : Node_Id; E : Entity_Id; K : Node_Kind) is
524 Loc : constant Source_Ptr := Sloc (N);
525 Typ : constant Entity_Id := Etype (N);
526 Left : constant Node_Id := First_Actual (N);
527 Right : constant Node_Id := Next_Actual (Left);
528 Ltyp : constant Node_Id := Etype (Left);
529 Rtyp : constant Node_Id := Etype (Right);
533 Snode := New_Node (K, Loc);
534 Set_Left_Opnd (Snode, Relocate_Node (Left));
535 Set_Right_Opnd (Snode, Relocate_Node (Right));
536 Set_Chars (Snode, Chars (E));
537 Set_Etype (Snode, Base_Type (Typ));
538 Set_Entity (Snode, E);
540 if Compile_Time_Known_Value (Type_High_Bound (Rtyp))
541 and then Expr_Value (Type_High_Bound (Rtyp)) < Esize (Ltyp)
543 Set_Shift_Count_OK (Snode, True);
546 -- Do the rewrite. Note that we don't call Analyze and Resolve on
547 -- this node, because it already got analyzed and resolved when
548 -- it was a function call!
554 ------------------------
555 -- Expand_Source_Info --
556 ------------------------
558 procedure Expand_Source_Info (N : Node_Id; Nam : Name_Id) is
559 Loc : constant Source_Ptr := Sloc (N);
562 procedure Write_Entity_Name (E : Entity_Id);
563 -- Recursive procedure to construct string for qualified name of
564 -- enclosing program unit. The qualification stops at an enclosing
565 -- scope has no source name (block or loop). If entity is a subprogram
566 -- instance, skip enclosing wrapper package.
568 -----------------------
569 -- Write_Entity_Name --
570 -----------------------
572 procedure Write_Entity_Name (E : Entity_Id) is
574 TDef : constant Source_Buffer_Ptr :=
575 Source_Text (Get_Source_File_Index (Sloc (E)));
578 -- Nothing to do if at outer level
580 if Scope (E) = Standard_Standard then
583 -- If scope comes from source, write its name
585 elsif Comes_From_Source (Scope (E)) then
586 Write_Entity_Name (Scope (E));
587 Add_Char_To_Name_Buffer ('.');
589 -- If in wrapper package skip past it
591 elsif Is_Wrapper_Package (Scope (E)) then
592 Write_Entity_Name (Scope (Scope (E)));
593 Add_Char_To_Name_Buffer ('.');
595 -- Otherwise nothing to output (happens in unnamed block statements)
601 -- Loop to output the name
603 -- is this right wrt wide char encodings ??? (no!)
606 while TDef (SDef) in '0' .. '9'
607 or else TDef (SDef) >= 'A'
608 or else TDef (SDef) = ASCII.ESC
610 Add_Char_To_Name_Buffer (TDef (SDef));
613 end Write_Entity_Name;
615 -- Start of processing for Expand_Source_Info
620 if Nam = Name_Line then
622 Make_Integer_Literal (Loc,
623 Intval => UI_From_Int (Int (Get_Logical_Line_Number (Loc)))));
624 Analyze_And_Resolve (N, Standard_Positive);
631 Get_Decoded_Name_String
632 (Reference_Name (Get_Source_File_Index (Loc)));
634 when Name_Source_Location =>
635 Build_Location_String (Loc);
637 when Name_Enclosing_Entity =>
640 Ent := Current_Scope;
642 -- Skip enclosing blocks to reach enclosing unit
644 while Present (Ent) loop
645 exit when Ekind (Ent) /= E_Block
646 and then Ekind (Ent) /= E_Loop;
650 -- Ent now points to the relevant defining entity
653 Write_Entity_Name (Ent);
660 Make_String_Literal (Loc, Strval => String_From_Name_Buffer));
661 Analyze_And_Resolve (N, Standard_String);
664 Set_Is_Static_Expression (N);
665 end Expand_Source_Info;
667 ---------------------------
668 -- Expand_Unc_Conversion --
669 ---------------------------
671 procedure Expand_Unc_Conversion (N : Node_Id; E : Entity_Id) is
672 Func : constant Entity_Id := Entity (Name (N));
678 -- Rewrite as unchecked conversion node. Note that we must convert
679 -- the operand to the formal type of the input parameter of the
680 -- function, so that the resulting N_Unchecked_Type_Conversion
681 -- call indicates the correct types for Gigi.
683 -- Right now, we only do this if a scalar type is involved. It is
684 -- not clear if it is needed in other cases. If we do attempt to
685 -- do the conversion unconditionally, it crashes 3411-018. To be
686 -- investigated further ???
688 Conv := Relocate_Node (First_Actual (N));
689 Ftyp := Etype (First_Formal (Func));
691 if Is_Scalar_Type (Ftyp) then
692 Conv := Convert_To (Ftyp, Conv);
693 Set_Parent (Conv, N);
694 Analyze_And_Resolve (Conv);
697 -- The instantiation of Unchecked_Conversion creates a wrapper package,
698 -- and the target type is declared as a subtype of the actual. Recover
699 -- the actual, which is the subtype indic. in the subtype declaration
700 -- for the target type. This is semantically correct, and avoids
701 -- anomalies with access subtypes. For entities, leave type as is.
703 -- We do the analysis here, because we do not want the compiler
704 -- to try to optimize or otherwise reorganize the unchecked
709 if Is_Entity_Name (Conv) then
712 elsif Nkind (Parent (Ttyp)) = N_Subtype_Declaration then
713 Ttyp := Entity (Subtype_Indication (Parent (Etype (E))));
715 elsif Is_Itype (Ttyp) then
717 Entity (Subtype_Indication (Associated_Node_For_Itype (Ttyp)));
722 Rewrite (N, Unchecked_Convert_To (Ttyp, Conv));
726 if Nkind (N) = N_Unchecked_Type_Conversion then
727 Expand_N_Unchecked_Type_Conversion (N);
729 end Expand_Unc_Conversion;
731 -----------------------------
732 -- Expand_Unc_Deallocation --
733 -----------------------------
735 -- Generate the following Code :
737 -- if Arg /= null then
738 -- <Finalize_Call> (.., T'Class(Arg.all), ..); -- for controlled types
743 -- For a task, we also generate a call to Free_Task to ensure that the
744 -- task itself is freed if it is terminated, ditto for a simple protected
745 -- object, with a call to Finalize_Protection. For composite types that
746 -- have tasks or simple protected objects as components, we traverse the
747 -- structures to find and terminate those components.
749 procedure Expand_Unc_Deallocation (N : Node_Id) is
750 Loc : constant Source_Ptr := Sloc (N);
751 Arg : constant Node_Id := First_Actual (N);
752 Typ : constant Entity_Id := Etype (Arg);
753 Stmts : constant List_Id := New_List;
754 Rtyp : constant Entity_Id := Underlying_Type (Root_Type (Typ));
755 Pool : constant Entity_Id := Associated_Storage_Pool (Rtyp);
757 Desig_T : constant Entity_Id := Designated_Type (Typ);
765 Arg_Known_Non_Null : constant Boolean := Known_Non_Null (N);
766 -- This captures whether we know the argument to be non-null so that
767 -- we can avoid the test. The reason that we need to capture this is
768 -- that we analyze some generated statements before properly attaching
769 -- them to the tree, and that can disturb current value settings.
772 if No_Pool_Assigned (Rtyp) then
773 Error_Msg_N ("?deallocation from empty storage pool", N);
776 -- Nothing to do if we know the argument is null
778 if Known_Null (N) then
782 -- Processing for pointer to controlled type
784 if Controlled_Type (Desig_T) then
786 Make_Explicit_Dereference (Loc,
787 Prefix => Duplicate_Subexpr_No_Checks (Arg));
789 -- If the type is tagged, then we must force dispatching on the
790 -- finalization call because the designated type may not be the
791 -- actual type of the object.
793 if Is_Tagged_Type (Desig_T)
794 and then not Is_Class_Wide_Type (Desig_T)
796 Deref := Unchecked_Convert_To (Class_Wide_Type (Desig_T), Deref);
798 elsif not Is_Tagged_Type (Desig_T) then
800 -- Set type of result, to force a conversion when needed (see
801 -- exp_ch7, Convert_View), given that Deep_Finalize may be
802 -- inherited from the parent type, and we need the type of the
803 -- expression to see whether the conversion is in fact needed.
805 Set_Etype (Deref, Desig_T);
812 With_Detach => New_Reference_To (Standard_True, Loc));
814 if Abort_Allowed then
815 Prepend_To (Free_Cod,
816 Build_Runtime_Call (Loc, RE_Abort_Defer));
819 Make_Block_Statement (Loc, Handled_Statement_Sequence =>
820 Make_Handled_Sequence_Of_Statements (Loc,
821 Statements => Free_Cod,
823 New_Occurrence_Of (RTE (RE_Abort_Undefer_Direct), Loc)));
825 -- We now expand the exception (at end) handler. We set a
826 -- temporary parent pointer since we have not attached Blk
831 Expand_At_End_Handler
832 (Handled_Statement_Sequence (Blk), Entity (Identifier (Blk)));
835 -- We kill saved current values, since analyzing statements not
836 -- properly attached to the tree can set wrong current values.
841 Append_List_To (Stmts, Free_Cod);
845 -- For a task type, call Free_Task before freeing the ATCB
847 if Is_Task_Type (Desig_T) then
849 Stat : Node_Id := Prev (N);
854 -- An Abort followed by a Free will not do what the user
855 -- expects, because the abort is not immediate. This is
856 -- worth a friendly warning.
859 and then not Comes_From_Source (Original_Node (Stat))
865 and then Nkind (Original_Node (Stat)) = N_Abort_Statement
867 Stat := Original_Node (Stat);
868 Nam1 := First (Names (Stat));
869 Nam2 := Original_Node (First (Parameter_Associations (N)));
871 if Nkind (Nam1) = N_Explicit_Dereference
872 and then Is_Entity_Name (Prefix (Nam1))
873 and then Is_Entity_Name (Nam2)
874 and then Entity (Prefix (Nam1)) = Entity (Nam2)
876 Error_Msg_N ("abort may take time to complete?", N);
877 Error_Msg_N ("\deallocation might have no effect?", N);
878 Error_Msg_N ("\safer to wait for termination.?", N);
884 (Stmts, Cleanup_Task (N, Duplicate_Subexpr_No_Checks (Arg)));
886 -- For composite types that contain tasks, recurse over the structure
887 -- to build the selectors for the task subcomponents.
889 elsif Has_Task (Desig_T) then
890 if Is_Record_Type (Desig_T) then
891 Append_List_To (Stmts, Cleanup_Record (N, Arg, Desig_T));
893 elsif Is_Array_Type (Desig_T) then
894 Append_List_To (Stmts, Cleanup_Array (N, Arg, Desig_T));
898 -- Same for simple protected types. Eventually call Finalize_Protection
899 -- before freeing the PO for each protected component.
901 if Is_Simple_Protected_Type (Desig_T) then
903 Cleanup_Protected_Object (N, Duplicate_Subexpr_No_Checks (Arg)));
905 elsif Has_Simple_Protected_Object (Desig_T) then
906 if Is_Record_Type (Desig_T) then
907 Append_List_To (Stmts, Cleanup_Record (N, Arg, Desig_T));
908 elsif Is_Array_Type (Desig_T) then
909 Append_List_To (Stmts, Cleanup_Array (N, Arg, Desig_T));
913 -- Normal processing for non-controlled types
915 Free_Arg := Duplicate_Subexpr_No_Checks (Arg);
916 Free_Node := Make_Free_Statement (Loc, Empty);
917 Append_To (Stmts, Free_Node);
918 Set_Storage_Pool (Free_Node, Pool);
920 -- Deal with storage pool
922 if Present (Pool) then
924 -- Freeing the secondary stack is meaningless
926 if Is_RTE (Pool, RE_SS_Pool) then
929 elsif Is_Class_Wide_Type (Etype (Pool)) then
931 -- Case of a class-wide pool type: make a dispatching call
932 -- to Deallocate through the class-wide Deallocate_Any.
934 Set_Procedure_To_Call (Free_Node,
935 RTE (RE_Deallocate_Any));
938 -- Case of a specific pool type: make a statically bound call
940 Set_Procedure_To_Call (Free_Node,
941 Find_Prim_Op (Etype (Pool), Name_Deallocate));
945 if Present (Procedure_To_Call (Free_Node)) then
947 -- For all cases of a Deallocate call, the back-end needs to be
948 -- able to compute the size of the object being freed. This may
949 -- require some adjustments for objects of dynamic size.
951 -- If the type is class wide, we generate an implicit type with the
952 -- right dynamic size, so that the deallocate call gets the right
953 -- size parameter computed by GIGI. Same for an access to
954 -- unconstrained packed array.
956 if Is_Class_Wide_Type (Desig_T)
958 (Is_Array_Type (Desig_T)
959 and then not Is_Constrained (Desig_T)
960 and then Is_Packed (Desig_T))
963 Deref : constant Node_Id :=
964 Make_Explicit_Dereference (Loc,
965 Duplicate_Subexpr_No_Checks (Arg));
970 Set_Etype (Deref, Typ);
971 Set_Parent (Deref, Free_Node);
972 D_Subtyp := Make_Subtype_From_Expr (Deref, Desig_T);
974 if Nkind (D_Subtyp) in N_Has_Entity then
975 D_Type := Entity (D_Subtyp);
978 D_Type := Make_Defining_Identifier (Loc,
979 New_Internal_Name ('A'));
981 Make_Subtype_Declaration (Loc,
982 Defining_Identifier => D_Type,
983 Subtype_Indication => D_Subtyp));
984 Freeze_Itype (D_Type, N);
988 Set_Actual_Designated_Subtype (Free_Node, D_Type);
994 -- Ada 2005 (AI-251): In case of abstract interface type we must
995 -- displace the pointer to reference the base of the object to
996 -- deallocate its memory.
999 -- free (Base_Address (Obj_Ptr))
1001 if Is_Interface (Directly_Designated_Type (Typ)) then
1002 Set_Expression (Free_Node,
1003 Unchecked_Convert_To (Typ,
1004 Make_Function_Call (Loc,
1005 Name => New_Reference_To (RTE (RE_Base_Address), Loc),
1006 Parameter_Associations => New_List (
1007 Unchecked_Convert_To (RTE (RE_Address), Free_Arg)))));
1013 Set_Expression (Free_Node, Free_Arg);
1016 -- Only remaining step is to set result to null, or generate a
1017 -- raise of constraint error if the target object is "not null".
1019 if Can_Never_Be_Null (Etype (Arg)) then
1021 Make_Raise_Constraint_Error (Loc,
1022 Reason => CE_Access_Check_Failed));
1026 Lhs : constant Node_Id := Duplicate_Subexpr_No_Checks (Arg);
1028 Set_Assignment_OK (Lhs);
1030 Make_Assignment_Statement (Loc,
1032 Expression => Make_Null (Loc)));
1036 -- If we know the argument is non-null, then make a block statement
1037 -- that contains the required statements, no need for a test.
1039 if Arg_Known_Non_Null then
1041 Make_Block_Statement (Loc,
1042 Handled_Statement_Sequence =>
1043 Make_Handled_Sequence_Of_Statements (Loc,
1044 Statements => Stmts));
1046 -- If the argument may be null, wrap the statements inside an IF that
1047 -- does an explicit test to exclude the null case.
1051 Make_Implicit_If_Statement (N,
1054 Left_Opnd => Duplicate_Subexpr (Arg),
1055 Right_Opnd => Make_Null (Loc)),
1056 Then_Statements => Stmts);
1061 Rewrite (N, Gen_Code);
1063 end Expand_Unc_Deallocation;
1065 -----------------------
1066 -- Expand_To_Address --
1067 -----------------------
1069 procedure Expand_To_Address (N : Node_Id) is
1070 Loc : constant Source_Ptr := Sloc (N);
1071 Arg : constant Node_Id := First_Actual (N);
1075 Remove_Side_Effects (Arg);
1077 Obj := Make_Explicit_Dereference (Loc, Relocate_Node (Arg));
1080 Make_Conditional_Expression (Loc,
1081 Expressions => New_List (
1083 Left_Opnd => New_Copy_Tree (Arg),
1084 Right_Opnd => Make_Null (Loc)),
1085 New_Occurrence_Of (RTE (RE_Null_Address), Loc),
1086 Make_Attribute_Reference (Loc,
1087 Attribute_Name => Name_Address,
1090 Analyze_And_Resolve (N, RTE (RE_Address));
1091 end Expand_To_Address;
1093 -----------------------
1094 -- Expand_To_Pointer --
1095 -----------------------
1097 procedure Expand_To_Pointer (N : Node_Id) is
1098 Arg : constant Node_Id := First_Actual (N);
1101 Rewrite (N, Unchecked_Convert_To (Etype (N), Arg));
1103 end Expand_To_Pointer;