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 3, 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 COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 ------------------------------------------------------------------------------
26 with Atree; use Atree;
27 with Checks; use Checks;
28 with Einfo; use Einfo;
29 with Elists; use Elists;
30 with Errout; use Errout;
31 with Exp_Atag; use Exp_Atag;
32 with Exp_Ch4; use Exp_Ch4;
33 with Exp_Ch7; use Exp_Ch7;
34 with Exp_Ch11; use Exp_Ch11;
35 with Exp_Code; use Exp_Code;
36 with Exp_Fixd; use Exp_Fixd;
37 with Exp_Util; use Exp_Util;
38 with Freeze; use Freeze;
39 with Namet; use Namet;
40 with Nmake; use Nmake;
41 with Nlists; use Nlists;
42 with Restrict; use Restrict;
43 with Rident; use Rident;
44 with Rtsfind; use Rtsfind;
46 with Sem_Eval; use Sem_Eval;
47 with Sem_Res; use Sem_Res;
48 with Sem_Util; use Sem_Util;
49 with Sinfo; use Sinfo;
50 with Sinput; use Sinput;
51 with Snames; use Snames;
52 with Stand; use Stand;
53 with Stringt; use Stringt;
54 with Tbuild; use Tbuild;
55 with Uintp; use Uintp;
56 with Urealp; use Urealp;
58 package body Exp_Intr is
60 -----------------------
61 -- Local Subprograms --
62 -----------------------
64 procedure Expand_Is_Negative (N : Node_Id);
65 -- Expand a call to the intrinsic Is_Negative function
67 procedure Expand_Dispatching_Constructor_Call (N : Node_Id);
68 -- Expand a call to an instantiation of Generic_Dispatching_Constructor
69 -- into a dispatching call to the actual subprogram associated with the
70 -- Constructor formal subprogram, passing it the Parameters actual of
71 -- the call to the instantiation and dispatching based on call's Tag
74 procedure Expand_Exception_Call (N : Node_Id; Ent : RE_Id);
75 -- Expand a call to Exception_Information/Message/Name. The first
76 -- parameter, N, is the node for the function call, and Ent is the
77 -- entity for the corresponding routine in the Ada.Exceptions package.
79 procedure Expand_Import_Call (N : Node_Id);
80 -- Expand a call to Import_Address/Longest_Integer/Value. The parameter
81 -- N is the node for the function call.
83 procedure Expand_Shift (N : Node_Id; E : Entity_Id; K : Node_Kind);
84 -- Expand an intrinsic shift operation, N and E are from the call to
85 -- Expand_Intrinsic_Call (call node and subprogram spec entity) and
86 -- K is the kind for the shift node
88 procedure Expand_Unc_Conversion (N : Node_Id; E : Entity_Id);
89 -- Expand a call to an instantiation of Unchecked_Convertion into a node
90 -- N_Unchecked_Type_Conversion.
92 procedure Expand_Unc_Deallocation (N : Node_Id);
93 -- Expand a call to an instantiation of Unchecked_Deallocation into a node
94 -- N_Free_Statement and appropriate context.
96 procedure Expand_To_Address (N : Node_Id);
97 procedure Expand_To_Pointer (N : Node_Id);
98 -- Expand a call to corresponding function, declared in an instance of
99 -- System.Addess_To_Access_Conversions.
101 procedure Expand_Source_Info (N : Node_Id; Nam : Name_Id);
102 -- Rewrite the node by the appropriate string or positive constant.
103 -- Nam can be one of the following:
104 -- Name_File - expand string that is the name of source file
105 -- Name_Line - expand integer line number
106 -- Name_Source_Location - expand string of form file:line
107 -- Name_Enclosing_Entity - expand string with name of enclosing entity
109 -----------------------------------------
110 -- Expand_Dispatching_Constructor_Call --
111 -----------------------------------------
113 -- Transform a call to an instantiation of Generic_Dispatching_Constructor
116 -- GDC_Instance (The_Tag, Parameters'Access)
118 -- to a class-wide conversion of a dispatching call to the actual
119 -- associated with the formal subprogram Construct, designating The_Tag
120 -- as the controlling tag of the call:
122 -- T'Class (Construct'Actual (Params)) -- Controlling tag is The_Tag
124 -- which will eventually be expanded to the following:
126 -- T'Class (The_Tag.all (Construct'Actual'Index).all (Params))
128 -- A class-wide membership test is also generated, preceding the call, to
129 -- ensure that the controlling tag denotes a type in T'Class.
131 procedure Expand_Dispatching_Constructor_Call (N : Node_Id) is
132 Loc : constant Source_Ptr := Sloc (N);
133 Tag_Arg : constant Node_Id := First_Actual (N);
134 Param_Arg : constant Node_Id := Next_Actual (Tag_Arg);
135 Subp_Decl : constant Node_Id := Parent (Parent (Entity (Name (N))));
136 Inst_Pkg : constant Node_Id := Parent (Subp_Decl);
137 Act_Rename : Node_Id;
138 Act_Constr : Entity_Id;
139 Result_Typ : Entity_Id;
140 Cnstr_Call : Node_Id;
143 -- The subprogram is the third actual in the instantiation, and is
144 -- retrieved from the corresponding renaming declaration. However,
145 -- freeze nodes may appear before, so we retrieve the declaration
146 -- with an explicit loop.
148 Act_Rename := First (Visible_Declarations (Inst_Pkg));
149 while Nkind (Act_Rename) /= N_Subprogram_Renaming_Declaration loop
153 Act_Constr := Entity (Name (Act_Rename));
154 Result_Typ := Class_Wide_Type (Etype (Act_Constr));
156 -- Ada 2005 (AI-251): If the result is an interface type, the function
157 -- returns a class-wide interface type (otherwise the resulting object
158 -- would be abstract!)
160 if Is_Interface (Etype (Act_Constr)) then
161 Set_Etype (Act_Constr, Result_Typ);
164 -- Create the call to the actual Constructor function
167 Make_Function_Call (Loc,
168 Name => New_Occurrence_Of (Act_Constr, Loc),
169 Parameter_Associations => New_List (Relocate_Node (Param_Arg)));
171 -- Establish its controlling tag from the tag passed to the instance
172 -- The tag may be given by a function call, in which case a temporary
173 -- should be generated now, to prevent out-of-order insertions during
174 -- the expansion of that call when stack-checking is enabled.
176 Remove_Side_Effects (Tag_Arg);
177 Set_Controlling_Argument (Cnstr_Call, Relocate_Node (Tag_Arg));
179 -- Rewrite and analyze the call to the instance as a class-wide
180 -- conversion of the call to the actual constructor.
182 Rewrite (N, Convert_To (Result_Typ, Cnstr_Call));
183 Analyze_And_Resolve (N, Etype (Act_Constr));
185 -- Do not generate a run-time check on the built object if tag
186 -- checks are suppressed for the result type.
188 if Tag_Checks_Suppressed (Etype (Result_Typ)) then
191 -- Generate a class-wide membership test to ensure that the call's tag
192 -- argument denotes a type within the class. We must keep separate the
193 -- case in which the Result_Type of the constructor function is a tagged
194 -- type from the case in which it is an abstract interface because the
195 -- run-time subprogram required to check these cases differ (and have
196 -- one difference in their parameters profile).
198 -- Call CW_Membership if the Result_Type is a tagged type to look for
199 -- the tag in the table of ancestor tags.
201 elsif not Is_Interface (Result_Typ) then
203 Make_Implicit_If_Statement (N,
206 Build_CW_Membership (Loc,
207 Obj_Tag_Node => Duplicate_Subexpr (Tag_Arg),
210 Node (First_Elmt (Access_Disp_Table (
211 Root_Type (Result_Typ)))), Loc))),
213 New_List (Make_Raise_Statement (Loc,
214 New_Occurrence_Of (RTE (RE_Tag_Error), Loc)))));
216 -- Call IW_Membership test if the Result_Type is an abstract interface
217 -- to look for the tag in the table of interface tags.
221 Make_Implicit_If_Statement (N,
224 Make_Function_Call (Loc,
225 Name => New_Occurrence_Of (RTE (RE_IW_Membership), Loc),
226 Parameter_Associations => New_List (
227 Make_Attribute_Reference (Loc,
228 Prefix => Duplicate_Subexpr (Tag_Arg),
229 Attribute_Name => Name_Address),
232 Node (First_Elmt (Access_Disp_Table (
233 Root_Type (Result_Typ)))), Loc)))),
236 Make_Raise_Statement (Loc,
237 Name => New_Occurrence_Of (RTE (RE_Tag_Error), Loc)))));
239 end Expand_Dispatching_Constructor_Call;
241 ---------------------------
242 -- Expand_Exception_Call --
243 ---------------------------
245 -- If the function call is not within an exception handler, then the call
246 -- is replaced by a null string. Otherwise the appropriate routine in
247 -- Ada.Exceptions is called passing the choice parameter specification
248 -- from the enclosing handler. If the enclosing handler lacks a choice
249 -- parameter, then one is supplied.
251 procedure Expand_Exception_Call (N : Node_Id; Ent : RE_Id) is
252 Loc : constant Source_Ptr := Sloc (N);
257 -- Climb up parents to see if we are in exception handler
261 -- Case of not in exception handler, replace by null string
265 Make_String_Literal (Loc,
269 -- Case of in exception handler
271 elsif Nkind (P) = N_Exception_Handler then
273 -- Handler cannot be used for a local raise, and furthermore, this
274 -- is a violation of the No_Exception_Propagation restriction.
276 Set_Local_Raise_Not_OK (P);
277 Check_Restriction (No_Exception_Propagation, N);
279 -- If no choice parameter present, then put one there. Note that
280 -- we do not need to put it on the entity chain, since no one will
281 -- be referencing it by normal visibility methods.
283 if No (Choice_Parameter (P)) then
284 E := Make_Defining_Identifier (Loc, New_Internal_Name ('E'));
285 Set_Choice_Parameter (P, E);
286 Set_Ekind (E, E_Variable);
287 Set_Etype (E, RTE (RE_Exception_Occurrence));
288 Set_Scope (E, Current_Scope);
292 Make_Function_Call (Loc,
293 Name => New_Occurrence_Of (RTE (Ent), Loc),
294 Parameter_Associations => New_List (
295 New_Occurrence_Of (Choice_Parameter (P), Loc))));
305 Analyze_And_Resolve (N, Standard_String);
306 end Expand_Exception_Call;
308 ------------------------
309 -- Expand_Import_Call --
310 ------------------------
312 -- The function call must have a static string as its argument. We create
313 -- a dummy variable which uses this string as the external name in an
314 -- Import pragma. The result is then obtained as the address of this
315 -- dummy variable, converted to the appropriate target type.
317 procedure Expand_Import_Call (N : Node_Id) is
318 Loc : constant Source_Ptr := Sloc (N);
319 Ent : constant Entity_Id := Entity (Name (N));
320 Str : constant Node_Id := First_Actual (N);
324 Dum := Make_Defining_Identifier (Loc, New_Internal_Name ('D'));
326 Insert_Actions (N, New_List (
327 Make_Object_Declaration (Loc,
328 Defining_Identifier => Dum,
330 New_Occurrence_Of (Standard_Character, Loc)),
333 Chars => Name_Import,
334 Pragma_Argument_Associations => New_List (
335 Make_Pragma_Argument_Association (Loc,
336 Expression => Make_Identifier (Loc, Name_Ada)),
338 Make_Pragma_Argument_Association (Loc,
339 Expression => Make_Identifier (Loc, Chars (Dum))),
341 Make_Pragma_Argument_Association (Loc,
342 Chars => Name_Link_Name,
343 Expression => Relocate_Node (Str))))));
346 Unchecked_Convert_To (Etype (Ent),
347 Make_Attribute_Reference (Loc,
348 Attribute_Name => Name_Address,
349 Prefix => Make_Identifier (Loc, Chars (Dum)))));
351 Analyze_And_Resolve (N, Etype (Ent));
352 end Expand_Import_Call;
354 ---------------------------
355 -- Expand_Intrinsic_Call --
356 ---------------------------
358 procedure Expand_Intrinsic_Call (N : Node_Id; E : Entity_Id) is
362 -- If the intrinsic subprogram is generic, gets its original name
364 if Present (Parent (E))
365 and then Present (Generic_Parent (Parent (E)))
367 Nam := Chars (Generic_Parent (Parent (E)));
372 if Nam = Name_Asm then
375 elsif Nam = Name_Divide then
376 Expand_Decimal_Divide_Call (N);
378 elsif Nam = Name_Exception_Information then
379 Expand_Exception_Call (N, RE_Exception_Information);
381 elsif Nam = Name_Exception_Message then
382 Expand_Exception_Call (N, RE_Exception_Message);
384 elsif Nam = Name_Exception_Name then
385 Expand_Exception_Call (N, RE_Exception_Name_Simple);
387 elsif Nam = Name_Generic_Dispatching_Constructor then
388 Expand_Dispatching_Constructor_Call (N);
390 elsif Nam = Name_Import_Address
392 Nam = Name_Import_Largest_Value
394 Nam = Name_Import_Value
396 Expand_Import_Call (N);
398 elsif Nam = Name_Is_Negative then
399 Expand_Is_Negative (N);
401 elsif Nam = Name_Rotate_Left then
402 Expand_Shift (N, E, N_Op_Rotate_Left);
404 elsif Nam = Name_Rotate_Right then
405 Expand_Shift (N, E, N_Op_Rotate_Right);
407 elsif Nam = Name_Shift_Left then
408 Expand_Shift (N, E, N_Op_Shift_Left);
410 elsif Nam = Name_Shift_Right then
411 Expand_Shift (N, E, N_Op_Shift_Right);
413 elsif Nam = Name_Shift_Right_Arithmetic then
414 Expand_Shift (N, E, N_Op_Shift_Right_Arithmetic);
416 elsif Nam = Name_Unchecked_Conversion then
417 Expand_Unc_Conversion (N, E);
419 elsif Nam = Name_Unchecked_Deallocation then
420 Expand_Unc_Deallocation (N);
422 elsif Nam = Name_To_Address then
423 Expand_To_Address (N);
425 elsif Nam = Name_To_Pointer then
426 Expand_To_Pointer (N);
428 elsif Nam = Name_File
429 or else Nam = Name_Line
430 or else Nam = Name_Source_Location
431 or else Nam = Name_Enclosing_Entity
433 Expand_Source_Info (N, Nam);
435 -- If we have a renaming, expand the call to the original operation,
436 -- which must itself be intrinsic, since renaming requires matching
437 -- conventions and this has already been checked.
439 elsif Present (Alias (E)) then
440 Expand_Intrinsic_Call (N, Alias (E));
442 -- The only other case is where an external name was specified,
443 -- since this is the only way that an otherwise unrecognized
444 -- name could escape the checking in Sem_Prag. Nothing needs
445 -- to be done in such a case, since we pass such a call to the
446 -- back end unchanged.
451 end Expand_Intrinsic_Call;
453 ------------------------
454 -- Expand_Is_Negative --
455 ------------------------
457 procedure Expand_Is_Negative (N : Node_Id) is
458 Loc : constant Source_Ptr := Sloc (N);
459 Opnd : constant Node_Id := Relocate_Node (First_Actual (N));
463 -- We replace the function call by the following expression
465 -- if Opnd < 0.0 then
468 -- if Opnd > 0.0 then
471 -- Float_Unsigned!(Float (Opnd)) /= 0
476 Make_Conditional_Expression (Loc,
477 Expressions => New_List (
479 Left_Opnd => Duplicate_Subexpr (Opnd),
480 Right_Opnd => Make_Real_Literal (Loc, Ureal_0)),
482 New_Occurrence_Of (Standard_True, Loc),
484 Make_Conditional_Expression (Loc,
485 Expressions => New_List (
487 Left_Opnd => Duplicate_Subexpr_No_Checks (Opnd),
488 Right_Opnd => Make_Real_Literal (Loc, Ureal_0)),
490 New_Occurrence_Of (Standard_False, Loc),
495 (RTE (RE_Float_Unsigned),
498 Duplicate_Subexpr_No_Checks (Opnd))),
500 Make_Integer_Literal (Loc, 0)))))));
502 Analyze_And_Resolve (N, Standard_Boolean);
503 end Expand_Is_Negative;
509 -- This procedure is used to convert a call to a shift function to the
510 -- corresponding operator node. This conversion is not done by the usual
511 -- circuit for converting calls to operator functions (e.g. "+"(1,2)) to
512 -- operator nodes, because shifts are not predefined operators.
514 -- As a result, whenever a shift is used in the source program, it will
515 -- remain as a call until converted by this routine to the operator node
516 -- form which Gigi is expecting to see.
518 -- Note: it is possible for the expander to generate shift operator nodes
519 -- directly, which will be analyzed in the normal manner by calling Analyze
520 -- and Resolve. Such shift operator nodes will not be seen by Expand_Shift.
522 procedure Expand_Shift (N : Node_Id; E : Entity_Id; K : Node_Kind) is
523 Loc : constant Source_Ptr := Sloc (N);
524 Typ : constant Entity_Id := Etype (N);
525 Left : constant Node_Id := First_Actual (N);
526 Right : constant Node_Id := Next_Actual (Left);
527 Ltyp : constant Node_Id := Etype (Left);
528 Rtyp : constant Node_Id := Etype (Right);
532 Snode := New_Node (K, Loc);
533 Set_Left_Opnd (Snode, Relocate_Node (Left));
534 Set_Right_Opnd (Snode, Relocate_Node (Right));
535 Set_Chars (Snode, Chars (E));
536 Set_Etype (Snode, Base_Type (Typ));
537 Set_Entity (Snode, E);
539 if Compile_Time_Known_Value (Type_High_Bound (Rtyp))
540 and then Expr_Value (Type_High_Bound (Rtyp)) < Esize (Ltyp)
542 Set_Shift_Count_OK (Snode, True);
545 -- Do the rewrite. Note that we don't call Analyze and Resolve on
546 -- this node, because it already got analyzed and resolved when
547 -- it was a function call!
553 ------------------------
554 -- Expand_Source_Info --
555 ------------------------
557 procedure Expand_Source_Info (N : Node_Id; Nam : Name_Id) is
558 Loc : constant Source_Ptr := Sloc (N);
561 procedure Write_Entity_Name (E : Entity_Id);
562 -- Recursive procedure to construct string for qualified name of
563 -- enclosing program unit. The qualification stops at an enclosing
564 -- scope has no source name (block or loop). If entity is a subprogram
565 -- instance, skip enclosing wrapper package.
567 -----------------------
568 -- Write_Entity_Name --
569 -----------------------
571 procedure Write_Entity_Name (E : Entity_Id) is
573 TDef : constant Source_Buffer_Ptr :=
574 Source_Text (Get_Source_File_Index (Sloc (E)));
577 -- Nothing to do if at outer level
579 if Scope (E) = Standard_Standard then
582 -- If scope comes from source, write its name
584 elsif Comes_From_Source (Scope (E)) then
585 Write_Entity_Name (Scope (E));
586 Add_Char_To_Name_Buffer ('.');
588 -- If in wrapper package skip past it
590 elsif Is_Wrapper_Package (Scope (E)) then
591 Write_Entity_Name (Scope (Scope (E)));
592 Add_Char_To_Name_Buffer ('.');
594 -- Otherwise nothing to output (happens in unnamed block statements)
600 -- Loop to output the name
602 -- is this right wrt wide char encodings ??? (no!)
605 while TDef (SDef) in '0' .. '9'
606 or else TDef (SDef) >= 'A'
607 or else TDef (SDef) = ASCII.ESC
609 Add_Char_To_Name_Buffer (TDef (SDef));
612 end Write_Entity_Name;
614 -- Start of processing for Expand_Source_Info
619 if Nam = Name_Line then
621 Make_Integer_Literal (Loc,
622 Intval => UI_From_Int (Int (Get_Logical_Line_Number (Loc)))));
623 Analyze_And_Resolve (N, Standard_Positive);
630 Get_Decoded_Name_String
631 (Reference_Name (Get_Source_File_Index (Loc)));
633 when Name_Source_Location =>
634 Build_Location_String (Loc);
636 when Name_Enclosing_Entity =>
639 Ent := Current_Scope;
641 -- Skip enclosing blocks to reach enclosing unit
643 while Present (Ent) loop
644 exit when Ekind (Ent) /= E_Block
645 and then Ekind (Ent) /= E_Loop;
649 -- Ent now points to the relevant defining entity
652 Write_Entity_Name (Ent);
659 Make_String_Literal (Loc, Strval => String_From_Name_Buffer));
660 Analyze_And_Resolve (N, Standard_String);
663 Set_Is_Static_Expression (N);
664 end Expand_Source_Info;
666 ---------------------------
667 -- Expand_Unc_Conversion --
668 ---------------------------
670 procedure Expand_Unc_Conversion (N : Node_Id; E : Entity_Id) is
671 Func : constant Entity_Id := Entity (Name (N));
677 -- Rewrite as unchecked conversion node. Note that we must convert
678 -- the operand to the formal type of the input parameter of the
679 -- function, so that the resulting N_Unchecked_Type_Conversion
680 -- call indicates the correct types for Gigi.
682 -- Right now, we only do this if a scalar type is involved. It is
683 -- not clear if it is needed in other cases. If we do attempt to
684 -- do the conversion unconditionally, it crashes 3411-018. To be
685 -- investigated further ???
687 Conv := Relocate_Node (First_Actual (N));
688 Ftyp := Etype (First_Formal (Func));
690 if Is_Scalar_Type (Ftyp) then
691 Conv := Convert_To (Ftyp, Conv);
692 Set_Parent (Conv, N);
693 Analyze_And_Resolve (Conv);
696 -- The instantiation of Unchecked_Conversion creates a wrapper package,
697 -- and the target type is declared as a subtype of the actual. Recover
698 -- the actual, which is the subtype indic. in the subtype declaration
699 -- for the target type. This is semantically correct, and avoids
700 -- anomalies with access subtypes. For entities, leave type as is.
702 -- We do the analysis here, because we do not want the compiler
703 -- to try to optimize or otherwise reorganize the unchecked
708 if Is_Entity_Name (Conv) then
711 elsif Nkind (Parent (Ttyp)) = N_Subtype_Declaration then
712 Ttyp := Entity (Subtype_Indication (Parent (Etype (E))));
714 elsif Is_Itype (Ttyp) then
716 Entity (Subtype_Indication (Associated_Node_For_Itype (Ttyp)));
721 Rewrite (N, Unchecked_Convert_To (Ttyp, Conv));
725 if Nkind (N) = N_Unchecked_Type_Conversion then
726 Expand_N_Unchecked_Type_Conversion (N);
728 end Expand_Unc_Conversion;
730 -----------------------------
731 -- Expand_Unc_Deallocation --
732 -----------------------------
734 -- Generate the following Code :
736 -- if Arg /= null then
737 -- <Finalize_Call> (.., T'Class(Arg.all), ..); -- for controlled types
742 -- For a task, we also generate a call to Free_Task to ensure that the
743 -- task itself is freed if it is terminated, ditto for a simple protected
744 -- object, with a call to Finalize_Protection. For composite types that
745 -- have tasks or simple protected objects as components, we traverse the
746 -- structures to find and terminate those components.
748 procedure Expand_Unc_Deallocation (N : Node_Id) is
749 Loc : constant Source_Ptr := Sloc (N);
750 Arg : constant Node_Id := First_Actual (N);
751 Typ : constant Entity_Id := Etype (Arg);
752 Stmts : constant List_Id := New_List;
753 Rtyp : constant Entity_Id := Underlying_Type (Root_Type (Typ));
754 Pool : constant Entity_Id := Associated_Storage_Pool (Rtyp);
756 Desig_T : constant Entity_Id := Designated_Type (Typ);
764 Arg_Known_Non_Null : constant Boolean := Known_Non_Null (N);
765 -- This captures whether we know the argument to be non-null so that
766 -- we can avoid the test. The reason that we need to capture this is
767 -- that we analyze some generated statements before properly attaching
768 -- them to the tree, and that can disturb current value settings.
771 if No_Pool_Assigned (Rtyp) then
772 Error_Msg_N ("?deallocation from empty storage pool!", N);
775 -- Nothing to do if we know the argument is null
777 if Known_Null (N) then
781 -- Processing for pointer to controlled type
783 if Controlled_Type (Desig_T) then
785 Make_Explicit_Dereference (Loc,
786 Prefix => Duplicate_Subexpr_No_Checks (Arg));
788 -- If the type is tagged, then we must force dispatching on the
789 -- finalization call because the designated type may not be the
790 -- actual type of the object.
792 if Is_Tagged_Type (Desig_T)
793 and then not Is_Class_Wide_Type (Desig_T)
795 Deref := Unchecked_Convert_To (Class_Wide_Type (Desig_T), Deref);
797 elsif not Is_Tagged_Type (Desig_T) then
799 -- Set type of result, to force a conversion when needed (see
800 -- exp_ch7, Convert_View), given that Deep_Finalize may be
801 -- inherited from the parent type, and we need the type of the
802 -- expression to see whether the conversion is in fact needed.
804 Set_Etype (Deref, Desig_T);
811 With_Detach => New_Reference_To (Standard_True, Loc));
813 if Abort_Allowed then
814 Prepend_To (Free_Cod,
815 Build_Runtime_Call (Loc, RE_Abort_Defer));
818 Make_Block_Statement (Loc, Handled_Statement_Sequence =>
819 Make_Handled_Sequence_Of_Statements (Loc,
820 Statements => Free_Cod,
822 New_Occurrence_Of (RTE (RE_Abort_Undefer_Direct), Loc)));
824 -- We now expand the exception (at end) handler. We set a
825 -- temporary parent pointer since we have not attached Blk
830 Expand_At_End_Handler
831 (Handled_Statement_Sequence (Blk), Entity (Identifier (Blk)));
834 -- We kill saved current values, since analyzing statements not
835 -- properly attached to the tree can set wrong current values.
840 Append_List_To (Stmts, Free_Cod);
844 -- For a task type, call Free_Task before freeing the ATCB
846 if Is_Task_Type (Desig_T) then
848 Stat : Node_Id := Prev (N);
853 -- An Abort followed by a Free will not do what the user
854 -- expects, because the abort is not immediate. This is
855 -- worth a friendly warning.
858 and then not Comes_From_Source (Original_Node (Stat))
864 and then Nkind (Original_Node (Stat)) = N_Abort_Statement
866 Stat := Original_Node (Stat);
867 Nam1 := First (Names (Stat));
868 Nam2 := Original_Node (First (Parameter_Associations (N)));
870 if Nkind (Nam1) = N_Explicit_Dereference
871 and then Is_Entity_Name (Prefix (Nam1))
872 and then Is_Entity_Name (Nam2)
873 and then Entity (Prefix (Nam1)) = Entity (Nam2)
875 Error_Msg_N ("abort may take time to complete?", N);
876 Error_Msg_N ("\deallocation might have no effect?", N);
877 Error_Msg_N ("\safer to wait for termination.?", N);
883 (Stmts, Cleanup_Task (N, Duplicate_Subexpr_No_Checks (Arg)));
885 -- For composite types that contain tasks, recurse over the structure
886 -- to build the selectors for the task subcomponents.
888 elsif Has_Task (Desig_T) then
889 if Is_Record_Type (Desig_T) then
890 Append_List_To (Stmts, Cleanup_Record (N, Arg, Desig_T));
892 elsif Is_Array_Type (Desig_T) then
893 Append_List_To (Stmts, Cleanup_Array (N, Arg, Desig_T));
897 -- Same for simple protected types. Eventually call Finalize_Protection
898 -- before freeing the PO for each protected component.
900 if Is_Simple_Protected_Type (Desig_T) then
902 Cleanup_Protected_Object (N, Duplicate_Subexpr_No_Checks (Arg)));
904 elsif Has_Simple_Protected_Object (Desig_T) then
905 if Is_Record_Type (Desig_T) then
906 Append_List_To (Stmts, Cleanup_Record (N, Arg, Desig_T));
907 elsif Is_Array_Type (Desig_T) then
908 Append_List_To (Stmts, Cleanup_Array (N, Arg, Desig_T));
912 -- Normal processing for non-controlled types
914 Free_Arg := Duplicate_Subexpr_No_Checks (Arg);
915 Free_Node := Make_Free_Statement (Loc, Empty);
916 Append_To (Stmts, Free_Node);
917 Set_Storage_Pool (Free_Node, Pool);
919 -- Deal with storage pool
921 if Present (Pool) then
923 -- Freeing the secondary stack is meaningless
925 if Is_RTE (Pool, RE_SS_Pool) then
928 elsif Is_Class_Wide_Type (Etype (Pool)) then
930 -- Case of a class-wide pool type: make a dispatching call
931 -- to Deallocate through the class-wide Deallocate_Any.
933 Set_Procedure_To_Call (Free_Node,
934 RTE (RE_Deallocate_Any));
937 -- Case of a specific pool type: make a statically bound call
939 Set_Procedure_To_Call (Free_Node,
940 Find_Prim_Op (Etype (Pool), Name_Deallocate));
944 if Present (Procedure_To_Call (Free_Node)) then
946 -- For all cases of a Deallocate call, the back-end needs to be
947 -- able to compute the size of the object being freed. This may
948 -- require some adjustments for objects of dynamic size.
950 -- If the type is class wide, we generate an implicit type with the
951 -- right dynamic size, so that the deallocate call gets the right
952 -- size parameter computed by GIGI. Same for an access to
953 -- unconstrained packed array.
955 if Is_Class_Wide_Type (Desig_T)
957 (Is_Array_Type (Desig_T)
958 and then not Is_Constrained (Desig_T)
959 and then Is_Packed (Desig_T))
962 Deref : constant Node_Id :=
963 Make_Explicit_Dereference (Loc,
964 Duplicate_Subexpr_No_Checks (Arg));
969 Set_Etype (Deref, Typ);
970 Set_Parent (Deref, Free_Node);
971 D_Subtyp := Make_Subtype_From_Expr (Deref, Desig_T);
973 if Nkind (D_Subtyp) in N_Has_Entity then
974 D_Type := Entity (D_Subtyp);
977 D_Type := Make_Defining_Identifier (Loc,
978 New_Internal_Name ('A'));
980 Make_Subtype_Declaration (Loc,
981 Defining_Identifier => D_Type,
982 Subtype_Indication => D_Subtyp));
983 Freeze_Itype (D_Type, N);
987 Set_Actual_Designated_Subtype (Free_Node, D_Type);
993 -- Ada 2005 (AI-251): In case of abstract interface type we must
994 -- displace the pointer to reference the base of the object to
995 -- deallocate its memory.
998 -- free (Base_Address (Obj_Ptr))
1000 if Is_Interface (Directly_Designated_Type (Typ)) then
1001 Set_Expression (Free_Node,
1002 Unchecked_Convert_To (Typ,
1003 Make_Function_Call (Loc,
1004 Name => New_Reference_To (RTE (RE_Base_Address), Loc),
1005 Parameter_Associations => New_List (
1006 Unchecked_Convert_To (RTE (RE_Address), Free_Arg)))));
1012 Set_Expression (Free_Node, Free_Arg);
1015 -- Only remaining step is to set result to null, or generate a
1016 -- raise of constraint error if the target object is "not null".
1018 if Can_Never_Be_Null (Etype (Arg)) then
1020 Make_Raise_Constraint_Error (Loc,
1021 Reason => CE_Access_Check_Failed));
1025 Lhs : constant Node_Id := Duplicate_Subexpr_No_Checks (Arg);
1027 Set_Assignment_OK (Lhs);
1029 Make_Assignment_Statement (Loc,
1031 Expression => Make_Null (Loc)));
1035 -- If we know the argument is non-null, then make a block statement
1036 -- that contains the required statements, no need for a test.
1038 if Arg_Known_Non_Null then
1040 Make_Block_Statement (Loc,
1041 Handled_Statement_Sequence =>
1042 Make_Handled_Sequence_Of_Statements (Loc,
1043 Statements => Stmts));
1045 -- If the argument may be null, wrap the statements inside an IF that
1046 -- does an explicit test to exclude the null case.
1050 Make_Implicit_If_Statement (N,
1053 Left_Opnd => Duplicate_Subexpr (Arg),
1054 Right_Opnd => Make_Null (Loc)),
1055 Then_Statements => Stmts);
1060 Rewrite (N, Gen_Code);
1062 end Expand_Unc_Deallocation;
1064 -----------------------
1065 -- Expand_To_Address --
1066 -----------------------
1068 procedure Expand_To_Address (N : Node_Id) is
1069 Loc : constant Source_Ptr := Sloc (N);
1070 Arg : constant Node_Id := First_Actual (N);
1074 Remove_Side_Effects (Arg);
1076 Obj := Make_Explicit_Dereference (Loc, Relocate_Node (Arg));
1079 Make_Conditional_Expression (Loc,
1080 Expressions => New_List (
1082 Left_Opnd => New_Copy_Tree (Arg),
1083 Right_Opnd => Make_Null (Loc)),
1084 New_Occurrence_Of (RTE (RE_Null_Address), Loc),
1085 Make_Attribute_Reference (Loc,
1086 Attribute_Name => Name_Address,
1089 Analyze_And_Resolve (N, RTE (RE_Address));
1090 end Expand_To_Address;
1092 -----------------------
1093 -- Expand_To_Pointer --
1094 -----------------------
1096 procedure Expand_To_Pointer (N : Node_Id) is
1097 Arg : constant Node_Id := First_Actual (N);
1100 Rewrite (N, Unchecked_Convert_To (Etype (N), Arg));
1102 end Expand_To_Pointer;