1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
11 -- Copyright (C) 1992-2002, 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 -- This package contains virtually all expansion mechanisms related to
33 with Atree; use Atree;
34 with Debug; use Debug;
35 with Einfo; use Einfo;
36 with Exp_Ch9; use Exp_Ch9;
37 with Exp_Ch11; use Exp_Ch11;
38 with Exp_Dbug; use Exp_Dbug;
39 with Exp_Tss; use Exp_Tss;
40 with Exp_Util; use Exp_Util;
41 with Freeze; use Freeze;
42 with Hostparm; use Hostparm;
44 with Lib.Xref; use Lib.Xref;
45 with Nlists; use Nlists;
46 with Nmake; use Nmake;
48 with Output; use Output;
49 with Restrict; use Restrict;
50 with Rtsfind; use Rtsfind;
51 with Targparm; use Targparm;
52 with Sinfo; use Sinfo;
54 with Sem_Ch3; use Sem_Ch3;
55 with Sem_Ch7; use Sem_Ch7;
56 with Sem_Ch8; use Sem_Ch8;
57 with Sem_Res; use Sem_Res;
58 with Sem_Type; use Sem_Type;
59 with Sem_Util; use Sem_Util;
60 with Snames; use Snames;
61 with Stand; use Stand;
62 with Tbuild; use Tbuild;
63 with Uintp; use Uintp;
65 package body Exp_Ch7 is
67 --------------------------------
68 -- Transient Scope Management --
69 --------------------------------
71 -- A transient scope is created when temporary objects are created by the
72 -- compiler. These temporary objects are allocated on the secondary stack
73 -- and the transient scope is responsible for finalizing the object when
74 -- appropriate and reclaiming the memory at the right time. The temporary
75 -- objects are generally the objects allocated to store the result of a
76 -- function returning an unconstrained or a tagged value. Expressions
77 -- needing to be wrapped in a transient scope (functions calls returning
78 -- unconstrained or tagged values) may appear in 3 different contexts which
79 -- lead to 3 different kinds of transient scope expansion:
81 -- 1. In a simple statement (procedure call, assignment, ...). In
82 -- this case the instruction is wrapped into a transient block.
83 -- (See Wrap_Transient_Statement for details)
85 -- 2. In an expression of a control structure (test in a IF statement,
86 -- expression in a CASE statement, ...).
87 -- (See Wrap_Transient_Expression for details)
89 -- 3. In a expression of an object_declaration. No wrapping is possible
90 -- here, so the finalization actions, if any are done right after the
91 -- declaration and the secondary stack deallocation is done in the
92 -- proper enclosing scope (see Wrap_Transient_Declaration for details)
94 -- Note about function returning tagged types: It has been decided to
95 -- always allocate their result in the secondary stack while it is not
96 -- absolutely mandatory when the tagged type is constrained because the
97 -- caller knows the size of the returned object and thus could allocate the
98 -- result in the primary stack. But, allocating them always in the
99 -- secondary stack simplifies many implementation hassles:
101 -- - If it is dispatching function call, the computation of the size of
102 -- the result is possible but complex from the outside.
104 -- - If the returned type is controlled, the assignment of the returned
105 -- value to the anonymous object involves an Adjust, and we have no
106 -- easy way to access the anonymous object created by the back-end
108 -- - If the returned type is class-wide, this is an unconstrained type
111 -- Furthermore, the little loss in efficiency which is the result of this
112 -- decision is not such a big deal because function returning tagged types
113 -- are not very much used in real life as opposed to functions returning
114 -- access to a tagged type
116 --------------------------------------------------
117 -- Transient Blocks and Finalization Management --
118 --------------------------------------------------
120 function Find_Node_To_Be_Wrapped (N : Node_Id) return Node_Id;
121 -- N is a node wich may generate a transient scope. Loop over the
122 -- parent pointers of N until it find the appropriate node to
123 -- wrap. It it returns Empty, it means that no transient scope is
124 -- needed in this context.
133 Is_Protected_Subprogram : Boolean;
134 Is_Task_Allocation_Block : Boolean;
135 Is_Asynchronous_Call_Block : Boolean)
137 -- Expand a the clean-up procedure for controlled and/or transient
138 -- block, and/or task master or task body, or blocks used to
139 -- implement task allocation or asynchronous entry calls, or
140 -- procedures used to implement protected procedures. Clean is the
141 -- entity for such a procedure. Mark is the entity for the secondary
142 -- stack mark, if empty only controlled block clean-up will be
143 -- performed. Flist is the entity for the local final list, if empty
144 -- only transient scope clean-up will be performed. The flags
145 -- Is_Task and Is_Master control the calls to the corresponding
146 -- finalization actions for a task body or for an entity that is a
149 procedure Set_Node_To_Be_Wrapped (N : Node_Id);
150 -- Set the field Node_To_Be_Wrapped of the current scope
152 procedure Insert_Actions_In_Scope_Around (N : Node_Id);
153 -- Insert the before-actions kept in the scope stack before N, and the
154 -- after after-actions, after N which must be a member of a list.
156 function Make_Transient_Block
160 -- Create a transient block whose name is Scope, which is also a
161 -- controlled block if Flist is not empty and whose only code is
162 -- Action (either a single statement or single declaration).
164 type Final_Primitives is (Initialize_Case, Adjust_Case, Finalize_Case);
165 -- This enumeration type is defined in order to ease sharing code for
166 -- building finalization procedures for composite types.
168 Name_Of : constant array (Final_Primitives) of Name_Id :=
169 (Initialize_Case => Name_Initialize,
170 Adjust_Case => Name_Adjust,
171 Finalize_Case => Name_Finalize);
173 Deep_Name_Of : constant array (Final_Primitives) of Name_Id :=
174 (Initialize_Case => Name_uDeep_Initialize,
175 Adjust_Case => Name_uDeep_Adjust,
176 Finalize_Case => Name_uDeep_Finalize);
178 procedure Build_Record_Deep_Procs (Typ : Entity_Id);
179 -- Build the deep Initialize/Adjust/Finalize for a record Typ with
180 -- Has_Component_Component set and store them using the TSS mechanism.
182 procedure Build_Array_Deep_Procs (Typ : Entity_Id);
183 -- Build the deep Initialize/Adjust/Finalize for a record Typ with
184 -- Has_Controlled_Component set and store them using the TSS mechanism.
186 function Make_Deep_Proc
187 (Prim : Final_Primitives;
191 -- This function generates the tree for Deep_Initialize, Deep_Adjust
192 -- or Deep_Finalize procedures according to the first parameter,
193 -- these procedures operate on the type Typ. The Stmts parameter
194 -- gives the body of the procedure.
196 function Make_Deep_Array_Body
197 (Prim : Final_Primitives;
200 -- This function generates the list of statements for implementing
201 -- Deep_Initialize, Deep_Adjust or Deep_Finalize procedures
202 -- according to the first parameter, these procedures operate on the
205 function Make_Deep_Record_Body
206 (Prim : Final_Primitives;
209 -- This function generates the list of statements for implementing
210 -- Deep_Initialize, Deep_Adjust or Deep_Finalize procedures
211 -- according to the first parameter, these procedures operate on the
214 function Convert_View
219 -- Proc is one of the Initialize/Adjust/Finalize operations, and
220 -- Arg is the argument being passed to it. Ind indicates which
221 -- formal of procedure Proc we are trying to match. This function
222 -- will, if necessary, generate an conversion between the partial
223 -- and full view of Arg to match the type of the formal of Proc,
224 -- or force a conversion to the class-wide type in the case where
225 -- the operation is abstract.
227 -----------------------------
228 -- Finalization Management --
229 -----------------------------
231 -- This part describe how Initialization/Adjusment/Finalization procedures
232 -- are generated and called. Two cases must be considered, types that are
233 -- Controlled (Is_Controlled flag set) and composite types that contain
234 -- controlled components (Has_Controlled_Component flag set). In the first
235 -- case the procedures to call are the user-defined primitive operations
236 -- Initialize/Adjust/Finalize. In the second case, GNAT generates
237 -- Deep_Initialize, Deep_Adjust and Deep_Finalize that are in charge of
238 -- calling the former procedures on the controlled components.
240 -- For records with Has_Controlled_Component set, a hidden "controller"
241 -- component is inserted. This controller component contains its own
242 -- finalization list on which all controlled components are attached
243 -- creating an indirection on the upper-level Finalization list. This
244 -- technique facilitates the management of objects whose number of
245 -- controlled components changes during execution. This controller
246 -- component is itself controlled and is attached to the upper-level
247 -- finalization chain. Its adjust primitive is in charge of calling
248 -- adjust on the components and adusting the finalization pointer to
249 -- match their new location (see a-finali.adb)
251 -- It is not possible to use a similar technique for arrays that have
252 -- Has_Controlled_Component set. In this case, deep procedures are
253 -- generated that call initialize/adjust/finalize + attachment or
254 -- detachment on the finalization list for all component.
256 -- Initialize calls: they are generated for declarations or dynamic
257 -- allocations of Controlled objects with no initial value. They are
258 -- always followed by an attachment to the current Finalization
259 -- Chain. For the dynamic allocation case this the chain attached to
260 -- the scope of the access type definition otherwise, this is the chain
261 -- of the current scope.
263 -- Adjust Calls: They are generated on 2 occasions: (1) for
264 -- declarations or dynamic allocations of Controlled objects with an
265 -- initial value. (2) after an assignment. In the first case they are
266 -- followed by an attachment to the final chain, in the second case
269 -- Finalization Calls: They are generated on (1) scope exit, (2)
270 -- assignments, (3) unchecked deallocations. In case (3) they have to
271 -- be detached from the final chain, in case (2) they must not and in
272 -- case (1) this is not important since we are exiting the scope
275 -- Here is a simple example of the expansion of a controlled block :
279 -- Y : Controlled := Init;
285 -- Z : R := (C => X);
294 -- _L : System.FI.Finalizable_Ptr;
296 -- procedure _Clean is
299 -- System.FI.Finalize_List (_L);
305 -- Attach_To_Final_List (_L, Finalizable (X), 1);
306 -- Y : Controlled := Init;
308 -- Attach_To_Final_List (_L, Finalizable (Y), 1);
311 -- _C : Record_Controller;
315 -- Deep_Initialize (W, _L, 1);
316 -- Z : R := (C => X);
317 -- Deep_Adjust (Z, _L, 1);
324 -- Deep_Finalize (W, False);
326 -- Deep_Adjust (W, _L, 0);
331 function Global_Flist_Ref (Flist_Ref : Node_Id) return Boolean;
332 -- Return True if Flist_Ref refers to a global final list, either
333 -- the object GLobal_Final_List which is used to attach standalone
334 -- objects, or any of the list controllers associated with library
335 -- level access to controlled objects
337 ----------------------------
338 -- Build_Array_Deep_Procs --
339 ----------------------------
341 procedure Build_Array_Deep_Procs (Typ : Entity_Id) is
345 Prim => Initialize_Case,
347 Stmts => Make_Deep_Array_Body (Initialize_Case, Typ)));
349 if not Is_Return_By_Reference_Type (Typ) then
354 Stmts => Make_Deep_Array_Body (Adjust_Case, Typ)));
359 Prim => Finalize_Case,
361 Stmts => Make_Deep_Array_Body (Finalize_Case, Typ)));
362 end Build_Array_Deep_Procs;
364 -----------------------------
365 -- Build_Controlling_Procs --
366 -----------------------------
368 procedure Build_Controlling_Procs (Typ : Entity_Id) is
370 if Is_Array_Type (Typ) then
371 Build_Array_Deep_Procs (Typ);
373 else pragma Assert (Is_Record_Type (Typ));
374 Build_Record_Deep_Procs (Typ);
376 end Build_Controlling_Procs;
378 ----------------------
379 -- Build_Final_List --
380 ----------------------
382 procedure Build_Final_List (N : Node_Id; Typ : Entity_Id) is
383 Loc : constant Source_Ptr := Sloc (N);
387 Set_Associated_Final_Chain (Typ,
388 Make_Defining_Identifier (Loc,
389 New_External_Name (Chars (Typ), 'L')));
392 Make_Object_Declaration (Loc,
393 Defining_Identifier =>
394 Associated_Final_Chain (Typ),
397 (RTE (RE_List_Controller), Loc));
399 -- The type may have been frozen already, and this is a late
400 -- freezing action, in which case the declaration must be elaborated
401 -- at once. If the call is for an allocator, the chain must also be
402 -- created now, because the freezing of the type does not build one.
403 -- Otherwise, the declaration is one of the freezing actions for a
404 -- user-defined type.
407 or else (Nkind (N) = N_Allocator
408 and then Ekind (Etype (N)) = E_Anonymous_Access_Type)
410 Insert_Action (N, Decl);
412 Append_Freeze_Action (Typ, Decl);
414 end Build_Final_List;
416 ---------------------
417 -- Build_Late_Proc --
418 ---------------------
420 procedure Build_Late_Proc (Typ : Entity_Id; Nam : Name_Id) is
422 for Final_Prim in Name_Of'Range loop
423 if Name_Of (Final_Prim) = Nam then
428 Stmts => Make_Deep_Record_Body (Final_Prim, Typ)));
433 -----------------------------
434 -- Build_Record_Deep_Procs --
435 -----------------------------
437 procedure Build_Record_Deep_Procs (Typ : Entity_Id) is
441 Prim => Initialize_Case,
443 Stmts => Make_Deep_Record_Body (Initialize_Case, Typ)));
445 if not Is_Return_By_Reference_Type (Typ) then
450 Stmts => Make_Deep_Record_Body (Adjust_Case, Typ)));
455 Prim => Finalize_Case,
457 Stmts => Make_Deep_Record_Body (Finalize_Case, Typ)));
458 end Build_Record_Deep_Procs;
460 ---------------------
461 -- Controlled_Type --
462 ---------------------
464 function Controlled_Type (T : Entity_Id) return Boolean is
466 function Has_Some_Controlled_Component (Rec : Entity_Id) return Boolean;
467 -- If type is not frozen yet, check explicitly among its components,
468 -- because flag is not necessarily set.
470 ------------------------------------
471 -- Has_Some_Controlled_Component --
472 ------------------------------------
474 function Has_Some_Controlled_Component (Rec : Entity_Id)
480 if Has_Controlled_Component (Rec) then
483 elsif not Is_Frozen (Rec) then
484 if Is_Record_Type (Rec) then
485 Comp := First_Entity (Rec);
487 while Present (Comp) loop
488 if not Is_Type (Comp)
489 and then Controlled_Type (Etype (Comp))
499 elsif Is_Array_Type (Rec) then
500 return Is_Controlled (Component_Type (Rec));
503 return Has_Controlled_Component (Rec);
508 end Has_Some_Controlled_Component;
510 -- Start of processing for Controlled_Type
513 -- Class-wide types must be treated as controlled because they may
514 -- contain an extension that has controlled components
516 return (Is_Class_Wide_Type (T)
517 and then not No_Run_Time
518 and then not In_Finalization_Root (T))
519 or else Is_Controlled (T)
520 or else Has_Some_Controlled_Component (T)
521 or else (Is_Concurrent_Type (T)
522 and then Present (Corresponding_Record_Type (T))
523 and then Controlled_Type (Corresponding_Record_Type (T)));
526 --------------------------
527 -- Controller_Component --
528 --------------------------
530 function Controller_Component (Typ : Entity_Id) return Entity_Id is
531 T : Entity_Id := Base_Type (Typ);
533 Comp_Scop : Entity_Id;
534 Res : Entity_Id := Empty;
535 Res_Scop : Entity_Id := Empty;
538 if Is_Class_Wide_Type (T) then
542 if Is_Private_Type (T) then
543 T := Underlying_Type (T);
546 -- Fetch the outermost controller
548 Comp := First_Entity (T);
549 while Present (Comp) loop
550 if Chars (Comp) = Name_uController then
551 Comp_Scop := Scope (Original_Record_Component (Comp));
553 -- If this controller is at the outermost level, no need to
554 -- look for another one
556 if Comp_Scop = T then
559 -- Otherwise record the outermost one and continue looking
561 elsif Res = Empty or else Is_Ancestor (Res_Scop, Comp_Scop) then
563 Res_Scop := Comp_Scop;
570 -- If we fall through the loop, there is no controller component
573 end Controller_Component;
579 function Convert_View
585 Fent : Entity_Id := First_Entity (Proc);
590 for J in 2 .. Ind loop
594 Ftyp := Etype (Fent);
596 if Nkind (Arg) = N_Type_Conversion
597 or else Nkind (Arg) = N_Unchecked_Type_Conversion
599 Atyp := Entity (Subtype_Mark (Arg));
604 if Is_Abstract (Proc) and then Is_Tagged_Type (Ftyp) then
605 return Unchecked_Convert_To (Class_Wide_Type (Ftyp), Arg);
608 and then Present (Atyp)
610 (Is_Private_Type (Ftyp) or else Is_Private_Type (Atyp))
611 and then Underlying_Type (Atyp) = Underlying_Type (Ftyp)
613 return Unchecked_Convert_To (Ftyp, Arg);
615 -- If the argument is already a conversion, as generated by
616 -- Make_Init_Call, set the target type to the type of the formal
617 -- directly, to avoid spurious typing problems.
619 elsif (Nkind (Arg) = N_Unchecked_Type_Conversion
620 or else Nkind (Arg) = N_Type_Conversion)
621 and then not Is_Class_Wide_Type (Atyp)
623 Set_Subtype_Mark (Arg, New_Occurrence_Of (Ftyp, Sloc (Arg)));
624 Set_Etype (Arg, Ftyp);
632 -------------------------------
633 -- Establish_Transient_Scope --
634 -------------------------------
636 -- This procedure is called each time a transient block has to be inserted
637 -- that is to say for each call to a function with unconstrained ot tagged
638 -- result. It creates a new scope on the stack scope in order to enclose
639 -- all transient variables generated
641 procedure Establish_Transient_Scope (N : Node_Id; Sec_Stack : Boolean) is
642 Loc : constant Source_Ptr := Sloc (N);
645 Sec_Stk : constant Boolean :=
646 Sec_Stack and not Functions_Return_By_DSP_On_Target;
647 -- We never need a secondary stack if functions return by DSP
650 -- Do not create a transient scope if we are already inside one
652 for S in reverse Scope_Stack.First .. Scope_Stack.Last loop
654 if Scope_Stack.Table (S).Is_Transient then
656 Set_Uses_Sec_Stack (Scope_Stack.Table (S).Entity);
661 -- If we have encountered Standard there are no enclosing
664 elsif Scope_Stack.Table (S).Entity = Standard_Standard then
670 Wrap_Node := Find_Node_To_Be_Wrapped (N);
672 -- Case of no wrap node, false alert, no transient scope needed
674 if No (Wrap_Node) then
677 -- Transient scope is required
680 New_Scope (New_Internal_Entity (E_Block, Current_Scope, Loc, 'B'));
681 Set_Scope_Is_Transient;
684 Set_Uses_Sec_Stack (Current_Scope);
685 Check_Restriction (No_Secondary_Stack, N);
688 Set_Etype (Current_Scope, Standard_Void_Type);
689 Set_Node_To_Be_Wrapped (Wrap_Node);
692 Write_Str (" <Transient>");
696 end Establish_Transient_Scope;
698 ----------------------------
699 -- Expand_Cleanup_Actions --
700 ----------------------------
702 procedure Expand_Cleanup_Actions (N : Node_Id) is
704 S : constant Entity_Id :=
706 Flist : constant Entity_Id :=
707 Finalization_Chain_Entity (S);
708 Is_Task : constant Boolean :=
709 (Nkind (Original_Node (N)) = N_Task_Body);
710 Is_Master : constant Boolean :=
711 Nkind (N) /= N_Entry_Body
712 and then Is_Task_Master (N);
713 Is_Protected : constant Boolean :=
714 Nkind (N) = N_Subprogram_Body
715 and then Is_Protected_Subprogram_Body (N);
716 Is_Task_Allocation : constant Boolean :=
717 Nkind (N) = N_Block_Statement
718 and then Is_Task_Allocation_Block (N);
719 Is_Asynchronous_Call : constant Boolean :=
720 Nkind (N) = N_Block_Statement
721 and then Is_Asynchronous_Call_Block (N);
724 Mark : Entity_Id := Empty;
725 New_Decls : List_Id := New_List;
728 Chain : Entity_Id := Empty;
734 -- Compute a location that is not directly in the user code in
735 -- order to avoid to generate confusing debug info. A good
736 -- approximation is the name of the outer user-defined scope
742 while not Comes_From_Source (S1) and then S1 /= Standard_Standard loop
749 -- There are cleanup actions only if the secondary stack needs
750 -- releasing or some finalizations are needed or in the context
753 if Uses_Sec_Stack (Current_Scope)
754 and then not Sec_Stack_Needed_For_Return (Current_Scope)
758 and then not Is_Master
760 and then not Is_Protected
761 and then not Is_Task_Allocation
762 and then not Is_Asynchronous_Call
767 -- Set polling off, since we don't need to poll during cleanup
768 -- actions, and indeed for the cleanup routine, which is executed
769 -- with aborts deferred, we don't want polling.
771 Old_Poll := Polling_Required;
772 Polling_Required := False;
774 -- Make sure we have a declaration list, since we will add to it
776 if No (Declarations (N)) then
777 Set_Declarations (N, New_List);
780 -- The task activation call has already been built for task
781 -- allocation blocks.
783 if not Is_Task_Allocation then
784 Build_Task_Activation_Call (N);
788 Establish_Task_Master (N);
791 -- If secondary stack is in use, expand:
792 -- _Mxx : constant Mark_Id := SS_Mark;
794 -- Suppress calls to SS_Mark and SS_Release if Java_VM,
795 -- since we never use the secondary stack on the JVM.
797 if Uses_Sec_Stack (Current_Scope)
798 and then not Sec_Stack_Needed_For_Return (Current_Scope)
801 Mark := Make_Defining_Identifier (Loc, New_Internal_Name ('M'));
802 Append_To (New_Decls,
803 Make_Object_Declaration (Loc,
804 Defining_Identifier => Mark,
805 Object_Definition => New_Reference_To (RTE (RE_Mark_Id), Loc),
807 Make_Function_Call (Loc,
808 Name => New_Reference_To (RTE (RE_SS_Mark), Loc))));
810 Set_Uses_Sec_Stack (Current_Scope, False);
813 -- If finalization list is present then expand:
814 -- Local_Final_List : System.FI.Finalizable_Ptr;
816 if Present (Flist) then
817 Append_To (New_Decls,
818 Make_Object_Declaration (Loc,
819 Defining_Identifier => Flist,
821 New_Reference_To (RTE (RE_Finalizable_Ptr), Loc)));
824 -- Clean-up procedure definition
826 Clean := Make_Defining_Identifier (Loc, Name_uClean);
827 Set_Suppress_Elaboration_Warnings (Clean);
828 Append_To (New_Decls,
829 Make_Clean (N, Clean, Mark, Flist,
834 Is_Asynchronous_Call));
836 -- If exception handlers are present, wrap the Sequence of
837 -- statements in a block because it is not possible to get
838 -- exception handlers and an AT END call in the same scope.
840 if Present (Exception_Handlers (Handled_Statement_Sequence (N))) then
842 Make_Block_Statement (Loc,
843 Handled_Statement_Sequence => Handled_Statement_Sequence (N));
844 Set_Handled_Statement_Sequence (N,
845 Make_Handled_Sequence_Of_Statements (Loc, New_List (Blok)));
848 -- Otherwise we do not wrap
855 -- Don't move the _chain Activation_Chain declaration in task
856 -- allocation blocks. Task allocation blocks use this object
857 -- in their cleanup handlers, and gigi complains if it is declared
858 -- in the sequence of statements of the scope that declares the
861 if Is_Task_Allocation then
862 Chain := Activation_Chain_Entity (N);
863 Decl := First (Declarations (N));
865 while Nkind (Decl) /= N_Object_Declaration
866 or else Defining_Identifier (Decl) /= Chain
869 pragma Assert (Present (Decl));
873 Prepend_To (New_Decls, Decl);
876 -- Now we move the declarations into the Sequence of statements
877 -- in order to get them protected by the AT END call. It may seem
878 -- weird to put declarations in the sequence of statement but in
879 -- fact nothing forbids that at the tree level. We also set the
880 -- First_Real_Statement field so that we remember where the real
881 -- statements (i.e. original statements) begin. Note that if we
882 -- wrapped the statements, the first real statement is inside the
883 -- inner block. If the First_Real_Statement is already set (as is
884 -- the case for subprogram bodies that are expansions of task bodies)
885 -- then do not reset it, because its declarative part would migrate
886 -- to the statement part.
889 if No (First_Real_Statement (Handled_Statement_Sequence (N))) then
890 Set_First_Real_Statement (Handled_Statement_Sequence (N),
891 First (Statements (Handled_Statement_Sequence (N))));
895 Set_First_Real_Statement (Handled_Statement_Sequence (N), Blok);
898 Append_List_To (Declarations (N),
899 Statements (Handled_Statement_Sequence (N)));
900 Set_Statements (Handled_Statement_Sequence (N), Declarations (N));
902 -- We need to reset the Sloc of the handled statement sequence to
903 -- properly reflect the new initial "statement" in the sequence.
906 (Handled_Statement_Sequence (N), Sloc (First (Declarations (N))));
908 -- The declarations of the _Clean procedure and finalization chain
909 -- replace the old declarations that have been moved inward
911 Set_Declarations (N, New_Decls);
912 Analyze_Declarations (New_Decls);
914 -- The At_End call is attached to the sequence of statements.
920 -- If the construct is a protected subprogram, then the call to
921 -- the corresponding unprotected program appears in a block which
922 -- is the last statement in the body, and it is this block that
923 -- must be covered by the At_End handler.
926 HSS := Handled_Statement_Sequence
927 (Last (Statements (Handled_Statement_Sequence (N))));
929 HSS := Handled_Statement_Sequence (N);
932 Set_At_End_Proc (HSS, New_Occurrence_Of (Clean, Loc));
933 Expand_At_End_Handler (HSS, Empty);
936 -- Restore saved polling mode
938 Polling_Required := Old_Poll;
939 end Expand_Cleanup_Actions;
941 -------------------------------
942 -- Expand_Ctrl_Function_Call --
943 -------------------------------
945 procedure Expand_Ctrl_Function_Call (N : Node_Id) is
946 Loc : constant Source_Ptr := Sloc (N);
947 Rtype : constant Entity_Id := Etype (N);
948 Utype : constant Entity_Id := Underlying_Type (Rtype);
952 Attach_Level : Uint := Uint_1;
953 Len_Ref : Node_Id := Empty;
955 function Last_Array_Component
959 -- Creates a reference to the last component of the array object
960 -- designated by Ref whose type is Typ.
962 function Last_Array_Component
968 Index_List : List_Id := New_List;
972 while N <= Number_Dimensions (Typ) loop
973 Append_To (Index_List,
974 Make_Attribute_Reference (Loc,
975 Prefix => Duplicate_Subexpr (Ref),
976 Attribute_Name => Name_Last,
977 Expressions => New_List (
978 Make_Integer_Literal (Loc, N))));
984 Make_Indexed_Component (Loc,
985 Prefix => Duplicate_Subexpr (Ref),
986 Expressions => Index_List);
987 end Last_Array_Component;
989 -- Start of processing for Expand_Ctrl_Function_Call
992 -- Optimization, if the returned value (which is on the sec-stack)
993 -- is returned again, no need to copy/readjust/finalize, we can just
994 -- pass the value thru (see Expand_N_Return_Statement), and thus no
995 -- attachment is needed
997 if Nkind (Parent (N)) = N_Return_Statement then
1001 -- Resolution is now finished, make sure we don't start analysis again
1002 -- because of the duplication
1005 Ref := Duplicate_Subexpr (N);
1007 -- Now we can generate the Attach Call, note that this value is
1008 -- always in the (secondary) stack and thus is attached to a singly
1009 -- linked final list:
1011 -- Resx := F (X)'reference;
1012 -- Attach_To_Final_List (_Lx, Resx.all, 1);
1013 -- or when there are controlled components
1014 -- Attach_To_Final_List (_Lx, Resx._controller, 1);
1015 -- or if it is an array with is_controlled components
1016 -- Attach_To_Final_List (_Lx, Resx (Resx'last), 3);
1017 -- An attach level of 3 means that a whole array is to be
1018 -- attached to the finalization list
1019 -- or if it is an array with has_controlled components
1020 -- Attach_To_Final_List (_Lx, Resx (Resx'last)._controller, 3);
1022 if Has_Controlled_Component (Rtype) then
1024 T1 : Entity_Id := Rtype;
1025 T2 : Entity_Id := Utype;
1028 if Is_Array_Type (T2) then
1030 Make_Attribute_Reference (Loc,
1031 Prefix => Duplicate_Subexpr (Unchecked_Convert_To (T2, Ref)),
1032 Attribute_Name => Name_Length);
1035 while Is_Array_Type (T2) loop
1037 Ref := Unchecked_Convert_To (T2, Ref);
1039 Ref := Last_Array_Component (Ref, T2);
1040 Attach_Level := Uint_3;
1041 T1 := Component_Type (T2);
1042 T2 := Underlying_Type (T1);
1045 if Has_Controlled_Component (T2) then
1047 Ref := Unchecked_Convert_To (T2, Ref);
1050 Make_Selected_Component (Loc,
1052 Selector_Name => Make_Identifier (Loc, Name_uController));
1056 -- Here we know that 'Ref' has a controller so we may as well
1057 -- attach it directly
1062 Flist_Ref => Find_Final_List (Current_Scope),
1063 With_Attach => Make_Integer_Literal (Loc, Attach_Level));
1066 -- Here, we have a controlled type that does not seem to have
1067 -- controlled components but it could be a class wide type whose
1068 -- further derivations have controlled components. So we don't know
1069 -- if the object itself needs to be attached or if it
1070 -- has a record controller. We need to call a runtime function
1071 -- (Deep_Tag_Attach) which knows what to do thanks to the
1072 -- RC_Offset in the dispatch table.
1075 Make_Procedure_Call_Statement (Loc,
1076 Name => New_Reference_To (RTE (RE_Deep_Tag_Attach), Loc),
1077 Parameter_Associations => New_List (
1078 Find_Final_List (Current_Scope),
1080 Make_Attribute_Reference (Loc,
1082 Attribute_Name => Name_Address),
1084 Make_Integer_Literal (Loc, Attach_Level)));
1087 if Present (Len_Ref) then
1089 Make_Implicit_If_Statement (N,
1090 Condition => Make_Op_Gt (Loc,
1091 Left_Opnd => Len_Ref,
1092 Right_Opnd => Make_Integer_Literal (Loc, 0)),
1093 Then_Statements => New_List (Action));
1096 Insert_Action (N, Action);
1097 end Expand_Ctrl_Function_Call;
1099 ---------------------------
1100 -- Expand_N_Package_Body --
1101 ---------------------------
1103 -- Add call to Activate_Tasks if body is an activator (actual
1104 -- processing is in chapter 9).
1106 -- Generate subprogram descriptor for elaboration routine
1108 -- ENcode entity names in package body
1110 procedure Expand_N_Package_Body (N : Node_Id) is
1111 Ent : Entity_Id := Corresponding_Spec (N);
1114 -- This is done only for non-generic packages
1116 if Ekind (Ent) = E_Package then
1117 New_Scope (Corresponding_Spec (N));
1118 Build_Task_Activation_Call (N);
1122 Set_Elaboration_Flag (N, Corresponding_Spec (N));
1124 -- Generate a subprogram descriptor for the elaboration routine of
1125 -- a package body if the package body has no pending instantiations
1126 -- and it has generated at least one exception handler
1128 if Present (Handler_Records (Body_Entity (Ent)))
1129 and then Is_Compilation_Unit (Ent)
1130 and then not Delay_Subprogram_Descriptors (Body_Entity (Ent))
1132 Generate_Subprogram_Descriptor_For_Package
1133 (N, Body_Entity (Ent));
1136 Set_In_Package_Body (Ent, False);
1138 -- Set to encode entity names in package body before gigi is called
1140 Qualify_Entity_Names (N);
1141 end Expand_N_Package_Body;
1143 ----------------------------------
1144 -- Expand_N_Package_Declaration --
1145 ----------------------------------
1147 -- Add call to Activate_Tasks if there are tasks declared and the
1148 -- package has no body. Note that in Ada83, this may result in
1149 -- premature activation of some tasks, given that we cannot tell
1150 -- whether a body will eventually appear.
1152 procedure Expand_N_Package_Declaration (N : Node_Id) is
1154 if Nkind (Parent (N)) = N_Compilation_Unit
1155 and then not Body_Required (Parent (N))
1156 and then not Unit_Requires_Body (Defining_Entity (N))
1157 and then Present (Activation_Chain_Entity (N))
1159 New_Scope (Defining_Entity (N));
1160 Build_Task_Activation_Call (N);
1164 -- Note: it is not necessary to worry about generating a subprogram
1165 -- descriptor, since the only way to get exception handlers into a
1166 -- package spec is to include instantiations, and that would cause
1167 -- generation of subprogram descriptors to be delayed in any case.
1169 -- Set to encode entity names in package spec before gigi is called
1171 Qualify_Entity_Names (N);
1172 end Expand_N_Package_Declaration;
1174 ---------------------
1175 -- Find_Final_List --
1176 ---------------------
1178 function Find_Final_List
1180 Ref : Node_Id := Empty)
1183 Loc : constant Source_Ptr := Sloc (Ref);
1189 -- Case of an internal component. The Final list is the record
1190 -- controller of the enclosing record
1192 if Present (Ref) then
1196 when N_Unchecked_Type_Conversion | N_Type_Conversion =>
1197 R := Expression (R);
1199 when N_Indexed_Component | N_Explicit_Dereference =>
1202 when N_Selected_Component =>
1206 when N_Identifier =>
1210 raise Program_Error;
1215 Make_Selected_Component (Loc,
1217 Make_Selected_Component (Loc,
1219 Selector_Name => Make_Identifier (Loc, Name_uController)),
1220 Selector_Name => Make_Identifier (Loc, Name_F));
1222 -- Case of a dynamically allocated object. The final list is the
1223 -- corresponding list controller (The next entity in the scope of
1224 -- the access type with the right type). If the type comes from a
1225 -- With_Type clause, no controller was created, and we use the
1226 -- global chain instead.
1228 elsif Is_Access_Type (E) then
1229 if not From_With_Type (E) then
1231 Make_Selected_Component (Loc,
1234 (Associated_Final_Chain (Base_Type (E)), Loc),
1235 Selector_Name => Make_Identifier (Loc, Name_F));
1237 return New_Reference_To (RTE (RE_Global_Final_List), Sloc (E));
1241 if Is_Dynamic_Scope (E) then
1244 S := Enclosing_Dynamic_Scope (E);
1247 -- When the finalization chain entity is 'Error', it means that
1248 -- there should not be any chain at that level and that the
1249 -- enclosing one should be used
1251 -- This is a nasty kludge, see ??? note in exp_ch11
1253 while Finalization_Chain_Entity (S) = Error loop
1254 S := Enclosing_Dynamic_Scope (S);
1257 if S = Standard_Standard then
1258 return New_Reference_To (RTE (RE_Global_Final_List), Sloc (E));
1260 if No (Finalization_Chain_Entity (S)) then
1262 Id := Make_Defining_Identifier (Sloc (S),
1263 New_Internal_Name ('F'));
1264 Set_Finalization_Chain_Entity (S, Id);
1266 -- Set momentarily some semantics attributes to allow normal
1267 -- analysis of expansions containing references to this chain.
1268 -- Will be fully decorated during the expansion of the scope
1271 Set_Ekind (Id, E_Variable);
1272 Set_Etype (Id, RTE (RE_Finalizable_Ptr));
1275 return New_Reference_To (Finalization_Chain_Entity (S), Sloc (E));
1278 end Find_Final_List;
1280 -----------------------------
1281 -- Find_Node_To_Be_Wrapped --
1282 -----------------------------
1284 function Find_Node_To_Be_Wrapped (N : Node_Id) return Node_Id is
1286 The_Parent : Node_Id;
1292 pragma Assert (P /= Empty);
1293 The_Parent := Parent (P);
1295 case Nkind (The_Parent) is
1297 -- Simple statement can be wrapped
1302 -- Usually assignments are good candidate for wrapping
1303 -- except when they have been generated as part of a
1304 -- controlled aggregate where the wrapping should take
1305 -- place more globally.
1307 when N_Assignment_Statement =>
1308 if No_Ctrl_Actions (The_Parent) then
1314 -- An entry call statement is a special case if it occurs in
1315 -- the context of a Timed_Entry_Call. In this case we wrap
1316 -- the entire timed entry call.
1318 when N_Entry_Call_Statement |
1319 N_Procedure_Call_Statement =>
1320 if Nkind (Parent (The_Parent)) = N_Entry_Call_Alternative
1322 Nkind (Parent (Parent (The_Parent))) = N_Timed_Entry_Call
1324 return Parent (Parent (The_Parent));
1329 -- Object declarations are also a boundary for the transient scope
1330 -- even if they are not really wrapped
1331 -- (see Wrap_Transient_Declaration)
1333 when N_Object_Declaration |
1334 N_Object_Renaming_Declaration |
1335 N_Subtype_Declaration =>
1338 -- The expression itself is to be wrapped if its parent is a
1339 -- compound statement or any other statement where the expression
1340 -- is known to be scalar
1342 when N_Accept_Alternative |
1343 N_Attribute_Definition_Clause |
1346 N_Delay_Alternative |
1347 N_Delay_Until_Statement |
1348 N_Delay_Relative_Statement |
1349 N_Discriminant_Association |
1351 N_Entry_Body_Formal_Part |
1354 N_Iteration_Scheme |
1355 N_Terminate_Alternative =>
1358 when N_Attribute_Reference =>
1360 if Is_Procedure_Attribute_Name
1361 (Attribute_Name (The_Parent))
1366 -- ??? No scheme yet for "for I in Expression'Range loop"
1367 -- ??? the current scheme for Expression wrapping doesn't apply
1368 -- ??? because a RANGE is NOT an expression. Tricky problem...
1369 -- ??? while this problem is not solved we have a potential for
1370 -- ??? leak and unfinalized intermediate objects here.
1372 when N_Loop_Parameter_Specification =>
1375 -- The following nodes contains "dummy calls" which don't
1376 -- need to be wrapped.
1378 when N_Parameter_Specification |
1379 N_Discriminant_Specification |
1380 N_Component_Declaration =>
1383 -- The return statement is not to be wrapped when the function
1384 -- itself needs wrapping at the outer-level
1386 when N_Return_Statement =>
1387 if Requires_Transient_Scope (Return_Type (The_Parent)) then
1393 -- If we leave a scope without having been able to find a node to
1394 -- wrap, something is going wrong but this can happen in error
1395 -- situation that are not detected yet (such as a dynamic string
1396 -- in a pragma export)
1398 when N_Subprogram_Body |
1399 N_Package_Declaration |
1401 N_Block_Statement =>
1404 -- otherwise continue the search
1410 end Find_Node_To_Be_Wrapped;
1412 ----------------------
1413 -- Global_Flist_Ref --
1414 ----------------------
1416 function Global_Flist_Ref (Flist_Ref : Node_Id) return Boolean is
1420 -- Look for the Global_Final_List
1422 if Is_Entity_Name (Flist_Ref) then
1423 Flist := Entity (Flist_Ref);
1425 -- Look for the final list associated with an access to controlled
1427 elsif Nkind (Flist_Ref) = N_Selected_Component
1428 and then Is_Entity_Name (Prefix (Flist_Ref))
1430 Flist := Entity (Prefix (Flist_Ref));
1435 return Present (Flist)
1436 and then Present (Scope (Flist))
1437 and then Enclosing_Dynamic_Scope (Flist) = Standard_Standard;
1438 end Global_Flist_Ref;
1440 ----------------------------------
1441 -- Has_New_Controlled_Component --
1442 ----------------------------------
1444 function Has_New_Controlled_Component (E : Entity_Id) return Boolean is
1448 if not Is_Tagged_Type (E) then
1449 return Has_Controlled_Component (E);
1450 elsif not Is_Derived_Type (E) then
1451 return Has_Controlled_Component (E);
1454 Comp := First_Component (E);
1455 while Present (Comp) loop
1457 if Chars (Comp) = Name_uParent then
1460 elsif Scope (Original_Record_Component (Comp)) = E
1461 and then Controlled_Type (Etype (Comp))
1466 Next_Component (Comp);
1470 end Has_New_Controlled_Component;
1472 --------------------------
1473 -- In_Finalization_Root --
1474 --------------------------
1476 -- It would seem simpler to test Scope (RTE (RE_Root_Controlled)) but
1477 -- the purpose of this function is to avoid a circular call to Rtsfind
1478 -- which would been caused by such a test.
1480 function In_Finalization_Root (E : Entity_Id) return Boolean is
1481 S : constant Entity_Id := Scope (E);
1484 return Chars (Scope (S)) = Name_System
1485 and then Chars (S) = Name_Finalization_Root
1486 and then Scope (Scope (S)) = Standard_Standard;
1487 end In_Finalization_Root;
1489 ------------------------------------
1490 -- Insert_Actions_In_Scope_Around --
1491 ------------------------------------
1493 procedure Insert_Actions_In_Scope_Around (N : Node_Id) is
1494 SE : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
1497 if Present (SE.Actions_To_Be_Wrapped_Before) then
1498 Insert_List_Before (N, SE.Actions_To_Be_Wrapped_Before);
1499 SE.Actions_To_Be_Wrapped_Before := No_List;
1502 if Present (SE.Actions_To_Be_Wrapped_After) then
1503 Insert_List_After (N, SE.Actions_To_Be_Wrapped_After);
1504 SE.Actions_To_Be_Wrapped_After := No_List;
1506 end Insert_Actions_In_Scope_Around;
1508 -----------------------
1509 -- Make_Adjust_Call --
1510 -----------------------
1512 function Make_Adjust_Call
1515 Flist_Ref : Node_Id;
1516 With_Attach : Node_Id)
1519 Loc : constant Source_Ptr := Sloc (Ref);
1520 Res : constant List_Id := New_List;
1523 Cref : Node_Id := Ref;
1525 Attach : Node_Id := With_Attach;
1528 if Is_Class_Wide_Type (Typ) then
1529 Utyp := Underlying_Type (Base_Type (Root_Type (Typ)));
1531 Utyp := Underlying_Type (Base_Type (Typ));
1534 Set_Assignment_OK (Cref);
1536 -- Deal with non-tagged derivation of private views
1538 if Is_Untagged_Derivation (Typ) then
1539 Utyp := Underlying_Type (Root_Type (Base_Type (Typ)));
1540 Cref := Unchecked_Convert_To (Utyp, Cref);
1541 Set_Assignment_OK (Cref);
1542 -- To prevent problems with UC see 1.156 RH ???
1545 -- If the underlying_type is a subtype, we are dealing with
1546 -- the completion of a private type. We need to access
1547 -- the base type and generate a conversion to it.
1549 if Utyp /= Base_Type (Utyp) then
1550 pragma Assert (Is_Private_Type (Typ));
1551 Utyp := Base_Type (Utyp);
1552 Cref := Unchecked_Convert_To (Utyp, Cref);
1555 -- We do not need to attach to one of the Global Final Lists
1556 -- the objects whose type is Finalize_Storage_Only
1558 if Finalize_Storage_Only (Typ)
1559 and then (Global_Flist_Ref (Flist_Ref)
1560 or else Entity (Constant_Value (RTE (RE_Garbage_Collected)))
1563 Attach := Make_Integer_Literal (Loc, 0);
1567 -- Deep_Adjust (Flist_Ref, Ref, With_Attach);
1569 if Has_Controlled_Component (Utyp)
1570 or else Is_Class_Wide_Type (Typ)
1572 if Is_Tagged_Type (Utyp) then
1573 Proc := Find_Prim_Op (Utyp, Deep_Name_Of (Adjust_Case));
1576 Proc := TSS (Utyp, Deep_Name_Of (Adjust_Case));
1579 Cref := Convert_View (Proc, Cref, 2);
1582 Make_Procedure_Call_Statement (Loc,
1583 Name => New_Reference_To (Proc, Loc),
1584 Parameter_Associations =>
1585 New_List (Flist_Ref, Cref, Attach)));
1588 -- if With_Attach then
1589 -- Attach_To_Final_List (Ref, Flist_Ref);
1593 else -- Is_Controlled (Utyp)
1595 Proc := Find_Prim_Op (Utyp, Name_Of (Adjust_Case));
1596 Cref := Convert_View (Proc, Cref);
1597 Cref2 := New_Copy_Tree (Cref);
1600 Make_Procedure_Call_Statement (Loc,
1601 Name => New_Reference_To (Proc, Loc),
1602 Parameter_Associations => New_List (Cref2)));
1604 Append_To (Res, Make_Attach_Call (Cref, Flist_Ref, Attach));
1606 -- Treat this as a reference to Adjust if the Adjust routine
1607 -- comes from source. The call is not explicit, but it is near
1608 -- enough, and we won't typically get explicit adjust calls.
1610 if Comes_From_Source (Proc) then
1611 Generate_Reference (Proc, Ref);
1616 end Make_Adjust_Call;
1618 ----------------------
1619 -- Make_Attach_Call --
1620 ----------------------
1623 -- System.FI.Attach_To_Final_List (Flist, Ref, Nb_Link)
1625 function Make_Attach_Call
1627 Flist_Ref : Node_Id;
1628 With_Attach : Node_Id)
1631 Loc : constant Source_Ptr := Sloc (Obj_Ref);
1634 -- Optimization: If the number of links is statically '0', don't
1635 -- call the attach_proc.
1637 if Nkind (With_Attach) = N_Integer_Literal
1638 and then Intval (With_Attach) = Uint_0
1640 return Make_Null_Statement (Loc);
1644 Make_Procedure_Call_Statement (Loc,
1645 Name => New_Reference_To (RTE (RE_Attach_To_Final_List), Loc),
1646 Parameter_Associations => New_List (
1648 OK_Convert_To (RTE (RE_Finalizable), Obj_Ref),
1650 end Make_Attach_Call;
1662 Is_Master : Boolean;
1663 Is_Protected_Subprogram : Boolean;
1664 Is_Task_Allocation_Block : Boolean;
1665 Is_Asynchronous_Call_Block : Boolean)
1668 Loc : constant Source_Ptr := Sloc (Clean);
1670 Stmt : List_Id := New_List;
1676 Param_Type : Entity_Id;
1677 Pid : Entity_Id := Empty;
1678 Cancel_Param : Entity_Id;
1682 if Restricted_Profile then
1684 (Stmt, Build_Runtime_Call (Loc, RE_Complete_Restricted_Task));
1686 Append_To (Stmt, Build_Runtime_Call (Loc, RE_Complete_Task));
1689 elsif Is_Master then
1690 if Restrictions (No_Task_Hierarchy) = False then
1691 Append_To (Stmt, Build_Runtime_Call (Loc, RE_Complete_Master));
1694 elsif Is_Protected_Subprogram then
1696 -- Add statements to the cleanup handler of the (ordinary)
1697 -- subprogram expanded to implement a protected subprogram,
1698 -- unlocking the protected object parameter and undeferring abortion.
1699 -- If this is a protected procedure, and the object contains
1700 -- entries, this also calls the entry service routine.
1702 -- NOTE: This cleanup handler references _object, a parameter
1703 -- to the procedure.
1705 -- Find the _object parameter representing the protected object.
1707 Spec := Parent (Corresponding_Spec (N));
1709 Param := First (Parameter_Specifications (Spec));
1711 Param_Type := Etype (Parameter_Type (Param));
1713 if Ekind (Param_Type) = E_Record_Type then
1714 Pid := Corresponding_Concurrent_Type (Param_Type);
1717 exit when not Present (Param) or else Present (Pid);
1721 pragma Assert (Present (Param));
1723 -- If the associated protected object declares entries,
1724 -- a protected procedure has to service entry queues.
1725 -- In this case, add
1727 -- Service_Entries (_object._object'Access);
1729 -- _object is the record used to implement the protected object.
1730 -- It is a parameter to the protected subprogram.
1732 if Nkind (Specification (N)) = N_Procedure_Specification
1733 and then Has_Entries (Pid)
1736 or else Restrictions (No_Entry_Queue) = False
1737 or else Number_Entries (Pid) > 1
1739 Name := New_Reference_To (RTE (RE_Service_Entries), Loc);
1741 Name := New_Reference_To (RTE (RE_Service_Entry), Loc);
1745 Make_Procedure_Call_Statement (Loc,
1747 Parameter_Associations => New_List (
1748 Make_Attribute_Reference (Loc,
1750 Make_Selected_Component (Loc,
1751 Prefix => New_Reference_To (
1752 Defining_Identifier (Param), Loc),
1754 Make_Identifier (Loc, Name_uObject)),
1755 Attribute_Name => Name_Unchecked_Access))));
1758 -- Unlock (_object._object'Access);
1760 -- _object is the record used to implement the protected object.
1761 -- It is a parameter to the protected subprogram.
1763 -- If the protected object is controlled (i.e it has entries or
1764 -- needs finalization for interrupt handling), call Unlock_Entries,
1765 -- except if the protected object follows the ravenscar profile, in
1766 -- which case call Unlock_Entry, otherwise call the simplified
1769 if Has_Entries (Pid)
1770 or else Has_Interrupt_Handler (Pid)
1771 or else Has_Attach_Handler (Pid)
1774 or else Restrictions (No_Entry_Queue) = False
1775 or else Number_Entries (Pid) > 1
1777 Unlock := New_Reference_To (RTE (RE_Unlock_Entries), Loc);
1779 Unlock := New_Reference_To (RTE (RE_Unlock_Entry), Loc);
1783 Unlock := New_Reference_To (RTE (RE_Unlock), Loc);
1787 Make_Procedure_Call_Statement (Loc,
1789 Parameter_Associations => New_List (
1790 Make_Attribute_Reference (Loc,
1792 Make_Selected_Component (Loc,
1794 New_Reference_To (Defining_Identifier (Param), Loc),
1796 Make_Identifier (Loc, Name_uObject)),
1797 Attribute_Name => Name_Unchecked_Access))));
1799 if Abort_Allowed then
1803 Make_Procedure_Call_Statement (Loc,
1806 RTE (RE_Abort_Undefer), Loc),
1807 Parameter_Associations => Empty_List));
1810 elsif Is_Task_Allocation_Block then
1812 -- Add a call to Expunge_Unactivated_Tasks to the cleanup
1813 -- handler of a block created for the dynamic allocation of
1816 -- Expunge_Unactivated_Tasks (_chain);
1818 -- where _chain is the list of tasks created by the allocator
1819 -- but not yet activated. This list will be empty unless
1820 -- the block completes abnormally.
1822 -- This only applies to dynamically allocated tasks;
1823 -- other unactivated tasks are completed by Complete_Task or
1826 -- NOTE: This cleanup handler references _chain, a local
1830 Make_Procedure_Call_Statement (Loc,
1833 RTE (RE_Expunge_Unactivated_Tasks), Loc),
1834 Parameter_Associations => New_List (
1835 New_Reference_To (Activation_Chain_Entity (N), Loc))));
1837 elsif Is_Asynchronous_Call_Block then
1839 -- Add a call to attempt to cancel the asynchronous entry call
1840 -- whenever the block containing the abortable part is exited.
1842 -- NOTE: This cleanup handler references C, a local object
1844 -- Get the argument to the Cancel procedure
1845 Cancel_Param := Entry_Cancel_Parameter (Entity (Identifier (N)));
1847 -- If it is of type Communication_Block, this must be a
1848 -- protected entry call.
1850 if Is_RTE (Etype (Cancel_Param), RE_Communication_Block) then
1854 -- if Enqueued (Cancel_Parameter) then
1856 Make_Implicit_If_Statement (Clean,
1857 Condition => Make_Function_Call (Loc,
1858 Name => New_Reference_To (
1859 RTE (RE_Enqueued), Loc),
1860 Parameter_Associations => New_List (
1861 New_Reference_To (Cancel_Param, Loc))),
1862 Then_Statements => New_List (
1864 -- Cancel_Protected_Entry_Call (Cancel_Param);
1866 Make_Procedure_Call_Statement (Loc,
1867 Name => New_Reference_To (
1868 RTE (RE_Cancel_Protected_Entry_Call), Loc),
1869 Parameter_Associations => New_List (
1870 New_Reference_To (Cancel_Param, Loc))))));
1872 -- Asynchronous delay
1874 elsif Is_RTE (Etype (Cancel_Param), RE_Delay_Block) then
1876 Make_Procedure_Call_Statement (Loc,
1877 Name => New_Reference_To (RTE (RE_Cancel_Async_Delay), Loc),
1878 Parameter_Associations => New_List (
1879 Make_Attribute_Reference (Loc,
1880 Prefix => New_Reference_To (Cancel_Param, Loc),
1881 Attribute_Name => Name_Unchecked_Access))));
1886 -- Append call to Cancel_Task_Entry_Call (C);
1889 Make_Procedure_Call_Statement (Loc,
1890 Name => New_Reference_To (
1891 RTE (RE_Cancel_Task_Entry_Call),
1893 Parameter_Associations => New_List (
1894 New_Reference_To (Cancel_Param, Loc))));
1899 if Present (Flist) then
1901 Make_Procedure_Call_Statement (Loc,
1902 Name => New_Reference_To (RTE (RE_Finalize_List), Loc),
1903 Parameter_Associations => New_List (
1904 New_Reference_To (Flist, Loc))));
1907 if Present (Mark) then
1909 Make_Procedure_Call_Statement (Loc,
1910 Name => New_Reference_To (RTE (RE_SS_Release), Loc),
1911 Parameter_Associations => New_List (
1912 New_Reference_To (Mark, Loc))));
1916 Make_Subprogram_Body (Loc,
1918 Make_Procedure_Specification (Loc,
1919 Defining_Unit_Name => Clean),
1921 Declarations => New_List,
1923 Handled_Statement_Sequence =>
1924 Make_Handled_Sequence_Of_Statements (Loc,
1925 Statements => Stmt));
1927 if Present (Flist) or else Is_Task or else Is_Master then
1928 Wrap_Cleanup_Procedure (Sbody);
1931 -- We do not want debug information for _Clean routines,
1932 -- since it just confuses the debugging operation unless
1933 -- we are debugging generated code.
1935 if not Debug_Generated_Code then
1936 Set_Debug_Info_Off (Clean, True);
1942 --------------------------
1943 -- Make_Deep_Array_Body --
1944 --------------------------
1946 -- Array components are initialized and adjusted in the normal order
1947 -- and finalized in the reverse order. Exceptions are handled and
1948 -- Program_Error is re-raise in the Adjust and Finalize case
1949 -- (RM 7.6.1(12)). Generate the following code :
1951 -- procedure Deep_<P> -- with <P> being Initialize or Adjust or Finalize
1952 -- (L : in out Finalizable_Ptr;
1956 -- for J1 in Typ'First (1) .. Typ'Last (1) loop
1957 -- ^ reverse ^ -- in the finalization case
1959 -- for J2 in Typ'First (n) .. Typ'Last (n) loop
1960 -- Make_<P>_Call (Typ, V (J1, .. , Jn), L, V);
1964 -- exception -- not in the
1965 -- when others => raise Program_Error; -- Initialize case
1968 function Make_Deep_Array_Body
1969 (Prim : Final_Primitives;
1973 Loc : constant Source_Ptr := Sloc (Typ);
1975 Index_List : constant List_Id := New_List;
1976 -- Stores the list of references to the indexes (one per dimension)
1978 function One_Component return List_Id;
1979 -- Create one statement to initialize/adjust/finalize one array
1980 -- component, designated by a full set of indices.
1982 function One_Dimension (N : Int) return List_Id;
1983 -- Create loop to deal with one dimension of the array. The single
1984 -- statement in the body of the loop initializes the inner dimensions if
1985 -- any, or else a single component.
1991 function One_Component return List_Id is
1992 Comp_Typ : constant Entity_Id := Component_Type (Typ);
1993 Comp_Ref : constant Node_Id :=
1994 Make_Indexed_Component (Loc,
1995 Prefix => Make_Identifier (Loc, Name_V),
1996 Expressions => Index_List);
1999 -- Set the etype of the component Reference, which is used to
2000 -- determine whether a conversion to a parent type is needed.
2002 Set_Etype (Comp_Ref, Comp_Typ);
2005 when Initialize_Case =>
2006 return Make_Init_Call (Comp_Ref, Comp_Typ,
2007 Make_Identifier (Loc, Name_L),
2008 Make_Identifier (Loc, Name_B));
2011 return Make_Adjust_Call (Comp_Ref, Comp_Typ,
2012 Make_Identifier (Loc, Name_L),
2013 Make_Identifier (Loc, Name_B));
2015 when Finalize_Case =>
2016 return Make_Final_Call (Comp_Ref, Comp_Typ,
2017 Make_Identifier (Loc, Name_B));
2025 function One_Dimension (N : Int) return List_Id is
2029 if N > Number_Dimensions (Typ) then
2030 return One_Component;
2034 Make_Defining_Identifier (Loc, New_External_Name ('J', N));
2036 Append_To (Index_List, New_Reference_To (Index, Loc));
2039 Make_Implicit_Loop_Statement (Typ,
2040 Identifier => Empty,
2042 Make_Iteration_Scheme (Loc,
2043 Loop_Parameter_Specification =>
2044 Make_Loop_Parameter_Specification (Loc,
2045 Defining_Identifier => Index,
2046 Discrete_Subtype_Definition =>
2047 Make_Attribute_Reference (Loc,
2048 Prefix => Make_Identifier (Loc, Name_V),
2049 Attribute_Name => Name_Range,
2050 Expressions => New_List (
2051 Make_Integer_Literal (Loc, N))),
2052 Reverse_Present => Prim = Finalize_Case)),
2053 Statements => One_Dimension (N + 1)));
2057 -- Start of processing for Make_Deep_Array_Body
2060 return One_Dimension (1);
2061 end Make_Deep_Array_Body;
2063 --------------------
2064 -- Make_Deep_Proc --
2065 --------------------
2068 -- procedure DEEP_<prim>
2069 -- (L : IN OUT Finalizable_Ptr; -- not for Finalize
2070 -- V : IN OUT <typ>;
2071 -- B : IN Short_Short_Integer) is
2074 -- exception -- Finalize and Adjust Cases only
2075 -- raise Program_Error; -- idem
2078 function Make_Deep_Proc
2079 (Prim : Final_Primitives;
2084 Loc : constant Source_Ptr := Sloc (Typ);
2086 Proc_Name : Entity_Id;
2087 Handler : List_Id := No_List;
2088 Subp_Body : Node_Id;
2092 if Prim = Finalize_Case then
2093 Formals := New_List;
2094 Type_B := Standard_Boolean;
2097 Formals := New_List (
2098 Make_Parameter_Specification (Loc,
2099 Defining_Identifier => Make_Defining_Identifier (Loc, Name_L),
2101 Out_Present => True,
2103 New_Reference_To (RTE (RE_Finalizable_Ptr), Loc)));
2104 Type_B := Standard_Short_Short_Integer;
2108 Make_Parameter_Specification (Loc,
2109 Defining_Identifier => Make_Defining_Identifier (Loc, Name_V),
2111 Out_Present => True,
2112 Parameter_Type => New_Reference_To (Typ, Loc)));
2115 Make_Parameter_Specification (Loc,
2116 Defining_Identifier => Make_Defining_Identifier (Loc, Name_B),
2117 Parameter_Type => New_Reference_To (Type_B, Loc)));
2119 if Prim = Finalize_Case or else Prim = Adjust_Case then
2120 Handler := New_List (
2121 Make_Exception_Handler (Loc,
2122 Exception_Choices => New_List (Make_Others_Choice (Loc)),
2123 Statements => New_List (
2124 Make_Raise_Program_Error (Loc,
2125 Reason => PE_Finalize_Raised_Exception))));
2128 Proc_Name := Make_Defining_Identifier (Loc, Deep_Name_Of (Prim));
2131 Make_Subprogram_Body (Loc,
2133 Make_Procedure_Specification (Loc,
2134 Defining_Unit_Name => Proc_Name,
2135 Parameter_Specifications => Formals),
2137 Declarations => Empty_List,
2138 Handled_Statement_Sequence =>
2139 Make_Handled_Sequence_Of_Statements (Loc,
2140 Statements => Stmts,
2141 Exception_Handlers => Handler));
2146 ---------------------------
2147 -- Make_Deep_Record_Body --
2148 ---------------------------
2150 -- The Deep procedures call the appropriate Controlling proc on the
2151 -- the controller component. In the init case, it also attach the
2152 -- controller to the current finalization list.
2154 function Make_Deep_Record_Body
2155 (Prim : Final_Primitives;
2159 Loc : constant Source_Ptr := Sloc (Typ);
2160 Controller_Typ : Entity_Id;
2161 Obj_Ref : constant Node_Id := Make_Identifier (Loc, Name_V);
2162 Controller_Ref : constant Node_Id :=
2163 Make_Selected_Component (Loc,
2166 Make_Identifier (Loc, Name_uController));
2169 if Is_Return_By_Reference_Type (Typ) then
2170 Controller_Typ := RTE (RE_Limited_Record_Controller);
2172 Controller_Typ := RTE (RE_Record_Controller);
2176 when Initialize_Case =>
2178 Res : constant List_Id := New_List;
2181 Append_List_To (Res,
2183 Ref => Controller_Ref,
2184 Typ => Controller_Typ,
2185 Flist_Ref => Make_Identifier (Loc, Name_L),
2186 With_Attach => Make_Identifier (Loc, Name_B)));
2188 -- When the type is also a controlled type by itself,
2189 -- Initialize it and attach it at the end of the internal
2190 -- finalization chain
2192 if Is_Controlled (Typ) then
2194 Make_Procedure_Call_Statement (Loc,
2195 Name => New_Reference_To (
2196 Find_Prim_Op (Typ, Name_Of (Prim)), Loc),
2198 Parameter_Associations =>
2199 New_List (New_Copy_Tree (Obj_Ref))));
2201 Append_To (Res, Make_Attach_Call (
2202 Obj_Ref => New_Copy_Tree (Obj_Ref),
2204 Make_Selected_Component (Loc,
2205 Prefix => New_Copy_Tree (Controller_Ref),
2206 Selector_Name => Make_Identifier (Loc, Name_F)),
2207 With_Attach => Make_Integer_Literal (Loc, 1)));
2215 Make_Adjust_Call (Controller_Ref, Controller_Typ,
2216 Make_Identifier (Loc, Name_L),
2217 Make_Identifier (Loc, Name_B));
2219 when Finalize_Case =>
2221 Make_Final_Call (Controller_Ref, Controller_Typ,
2222 Make_Identifier (Loc, Name_B));
2224 end Make_Deep_Record_Body;
2226 ----------------------
2227 -- Make_Final_Call --
2228 ----------------------
2230 function Make_Final_Call
2233 With_Detach : Node_Id)
2236 Loc : constant Source_Ptr := Sloc (Ref);
2237 Res : constant List_Id := New_List;
2244 if Is_Class_Wide_Type (Typ) then
2245 Utyp := Root_Type (Typ);
2248 elsif Is_Concurrent_Type (Typ) then
2249 Utyp := Corresponding_Record_Type (Typ);
2250 Cref := Convert_Concurrent (Ref, Typ);
2252 elsif Is_Private_Type (Typ)
2253 and then Present (Full_View (Typ))
2254 and then Is_Concurrent_Type (Full_View (Typ))
2256 Utyp := Corresponding_Record_Type (Full_View (Typ));
2257 Cref := Convert_Concurrent (Ref, Full_View (Typ));
2263 Utyp := Underlying_Type (Base_Type (Utyp));
2264 Set_Assignment_OK (Cref);
2266 -- Deal with non-tagged derivation of private views
2268 if Is_Untagged_Derivation (Typ) then
2269 Utyp := Underlying_Type (Root_Type (Base_Type (Typ)));
2270 Cref := Unchecked_Convert_To (Utyp, Cref);
2271 Set_Assignment_OK (Cref);
2272 -- To prevent problems with UC see 1.156 RH ???
2275 -- If the underlying_type is a subtype, we are dealing with
2276 -- the completion of a private type. We need to access
2277 -- the base type and generate a conversion to it.
2279 if Utyp /= Base_Type (Utyp) then
2280 pragma Assert (Is_Private_Type (Typ));
2281 Utyp := Base_Type (Utyp);
2282 Cref := Unchecked_Convert_To (Utyp, Cref);
2286 -- Deep_Finalize (Ref, With_Detach);
2288 if Has_Controlled_Component (Utyp)
2289 or else Is_Class_Wide_Type (Typ)
2291 if Is_Tagged_Type (Utyp) then
2292 Proc := Find_Prim_Op (Utyp, Deep_Name_Of (Finalize_Case));
2294 Proc := TSS (Utyp, Deep_Name_Of (Finalize_Case));
2297 Cref := Convert_View (Proc, Cref);
2300 Make_Procedure_Call_Statement (Loc,
2301 Name => New_Reference_To (Proc, Loc),
2302 Parameter_Associations =>
2303 New_List (Cref, With_Detach)));
2306 -- if With_Detach then
2307 -- Finalize_One (Ref);
2313 Proc := Find_Prim_Op (Utyp, Name_Of (Finalize_Case));
2315 if Chars (With_Detach) = Chars (Standard_True) then
2317 Make_Procedure_Call_Statement (Loc,
2318 Name => New_Reference_To (RTE (RE_Finalize_One), Loc),
2319 Parameter_Associations => New_List (
2320 OK_Convert_To (RTE (RE_Finalizable), Cref))));
2322 elsif Chars (With_Detach) = Chars (Standard_False) then
2324 Make_Procedure_Call_Statement (Loc,
2325 Name => New_Reference_To (Proc, Loc),
2326 Parameter_Associations =>
2327 New_List (Convert_View (Proc, Cref))));
2330 Cref2 := New_Copy_Tree (Cref);
2332 Make_Implicit_If_Statement (Ref,
2333 Condition => With_Detach,
2334 Then_Statements => New_List (
2335 Make_Procedure_Call_Statement (Loc,
2336 Name => New_Reference_To (RTE (RE_Finalize_One), Loc),
2337 Parameter_Associations => New_List (
2338 OK_Convert_To (RTE (RE_Finalizable), Cref)))),
2340 Else_Statements => New_List (
2341 Make_Procedure_Call_Statement (Loc,
2342 Name => New_Reference_To (Proc, Loc),
2343 Parameter_Associations =>
2344 New_List (Convert_View (Proc, Cref2))))));
2348 -- Treat this as a reference to Finalize if the Finalize routine
2349 -- comes from source. The call is not explicit, but it is near
2350 -- enough, and we won't typically get explicit adjust calls.
2352 if Comes_From_Source (Proc) then
2353 Generate_Reference (Proc, Ref);
2356 end Make_Final_Call;
2358 --------------------
2359 -- Make_Init_Call --
2360 --------------------
2362 function Make_Init_Call
2365 Flist_Ref : Node_Id;
2366 With_Attach : Node_Id)
2369 Loc : constant Source_Ptr := Sloc (Ref);
2371 Res : constant List_Id := New_List;
2376 Attach : Node_Id := With_Attach;
2379 if Is_Concurrent_Type (Typ) then
2381 Utyp := Corresponding_Record_Type (Typ);
2382 Cref := Convert_Concurrent (Ref, Typ);
2384 elsif Is_Private_Type (Typ)
2385 and then Present (Full_View (Typ))
2386 and then Is_Concurrent_Type (Underlying_Type (Typ))
2389 Utyp := Corresponding_Record_Type (Underlying_Type (Typ));
2390 Cref := Convert_Concurrent (Ref, Underlying_Type (Typ));
2398 Utyp := Underlying_Type (Base_Type (Utyp));
2400 Set_Assignment_OK (Cref);
2402 -- Deal with non-tagged derivation of private views
2404 if Is_Untagged_Derivation (Typ)
2405 and then not Is_Conc
2407 Utyp := Underlying_Type (Root_Type (Base_Type (Typ)));
2408 Cref := Unchecked_Convert_To (Utyp, Cref);
2409 Set_Assignment_OK (Cref);
2410 -- To prevent problems with UC see 1.156 RH ???
2413 -- If the underlying_type is a subtype, we are dealing with
2414 -- the completion of a private type. We need to access
2415 -- the base type and generate a conversion to it.
2417 if Utyp /= Base_Type (Utyp) then
2418 pragma Assert (Is_Private_Type (Typ));
2419 Utyp := Base_Type (Utyp);
2420 Cref := Unchecked_Convert_To (Utyp, Cref);
2423 -- We do not need to attach to one of the Global Final Lists
2424 -- the objects whose type is Finalize_Storage_Only
2426 if Finalize_Storage_Only (Typ)
2427 and then (Global_Flist_Ref (Flist_Ref)
2428 or else Entity (Constant_Value (RTE (RE_Garbage_Collected)))
2431 Attach := Make_Integer_Literal (Loc, 0);
2435 -- Deep_Initialize (Ref, Flist_Ref);
2437 if Has_Controlled_Component (Utyp) then
2438 Proc := TSS (Utyp, Deep_Name_Of (Initialize_Case));
2440 Cref := Convert_View (Proc, Cref, 2);
2443 Make_Procedure_Call_Statement (Loc,
2444 Name => New_Reference_To (Proc, Loc),
2445 Parameter_Associations => New_List (
2451 -- Attach_To_Final_List (Ref, Flist_Ref);
2452 -- Initialize (Ref);
2454 else -- Is_Controlled (Utyp)
2455 Proc := Find_Prim_Op (Utyp, Name_Of (Initialize_Case));
2456 Cref := Convert_View (Proc, Cref);
2457 Cref2 := New_Copy_Tree (Cref);
2460 Make_Procedure_Call_Statement (Loc,
2461 Name => New_Reference_To (Proc, Loc),
2462 Parameter_Associations => New_List (Cref2)));
2465 Make_Attach_Call (Cref, Flist_Ref, Attach));
2467 -- Treat this as a reference to Initialize if Initialize routine
2468 -- comes from source. The call is not explicit, but it is near
2469 -- enough, and we won't typically get explicit adjust calls.
2471 if Comes_From_Source (Proc) then
2472 Generate_Reference (Proc, Ref);
2479 --------------------------
2480 -- Make_Transient_Block --
2481 --------------------------
2483 -- If finalization is involved, this function just wraps the instruction
2484 -- into a block whose name is the transient block entity, and then
2485 -- Expand_Cleanup_Actions (called on the expansion of the handled
2486 -- sequence of statements will do the necessary expansions for
2489 function Make_Transient_Block
2494 Flist : constant Entity_Id := Finalization_Chain_Entity (Current_Scope);
2495 Decls : constant List_Id := New_List;
2496 Par : constant Node_Id := Parent (Action);
2497 Instrs : constant List_Id := New_List (Action);
2501 -- Case where only secondary stack use is involved
2503 if Uses_Sec_Stack (Current_Scope)
2505 and then Nkind (Action) /= N_Return_Statement
2506 and then Nkind (Par) /= N_Exception_Handler
2513 S := Scope (Current_Scope);
2517 -- At the outer level, no need to release the sec stack
2519 if S = Standard_Standard then
2520 Set_Uses_Sec_Stack (Current_Scope, False);
2523 -- In a function, only release the sec stack if the
2524 -- function does not return on the sec stack otherwise
2525 -- the result may be lost. The caller is responsible for
2528 elsif K = E_Function then
2529 Set_Uses_Sec_Stack (Current_Scope, False);
2531 if not Requires_Transient_Scope (Etype (S)) then
2532 if not Functions_Return_By_DSP_On_Target then
2533 Set_Uses_Sec_Stack (S, True);
2534 Check_Restriction (No_Secondary_Stack, Action);
2540 -- In a loop or entry we should install a block encompassing
2541 -- all the construct. For now just release right away.
2543 elsif K = E_Loop or else K = E_Entry then
2546 -- In a procedure or a block, we release on exit of the
2547 -- procedure or block. ??? memory leak can be created by
2550 elsif K = E_Procedure
2553 if not Functions_Return_By_DSP_On_Target then
2554 Set_Uses_Sec_Stack (S, True);
2555 Check_Restriction (No_Secondary_Stack, Action);
2558 Set_Uses_Sec_Stack (Current_Scope, False);
2568 -- Insert actions stuck in the transient scopes as well as all
2569 -- freezing nodes needed by those actions
2571 Insert_Actions_In_Scope_Around (Action);
2574 Last_Inserted : Node_Id := Prev (Action);
2577 if Present (Last_Inserted) then
2578 Freeze_All (First_Entity (Current_Scope), Last_Inserted);
2583 Make_Block_Statement (Loc,
2584 Identifier => New_Reference_To (Current_Scope, Loc),
2585 Declarations => Decls,
2586 Handled_Statement_Sequence =>
2587 Make_Handled_Sequence_Of_Statements (Loc, Statements => Instrs),
2588 Has_Created_Identifier => True);
2590 -- When the transient scope was established, we pushed the entry for
2591 -- the transient scope onto the scope stack, so that the scope was
2592 -- active for the installation of finalizable entities etc. Now we
2593 -- must remove this entry, since we have constructed a proper block.
2598 end Make_Transient_Block;
2600 ------------------------
2601 -- Node_To_Be_Wrapped --
2602 ------------------------
2604 function Node_To_Be_Wrapped return Node_Id is
2606 return Scope_Stack.Table (Scope_Stack.Last).Node_To_Be_Wrapped;
2607 end Node_To_Be_Wrapped;
2609 ----------------------------
2610 -- Set_Node_To_Be_Wrapped --
2611 ----------------------------
2613 procedure Set_Node_To_Be_Wrapped (N : Node_Id) is
2615 Scope_Stack.Table (Scope_Stack.Last).Node_To_Be_Wrapped := N;
2616 end Set_Node_To_Be_Wrapped;
2618 ----------------------------------
2619 -- Store_After_Actions_In_Scope --
2620 ----------------------------------
2622 procedure Store_After_Actions_In_Scope (L : List_Id) is
2623 SE : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
2626 if Present (SE.Actions_To_Be_Wrapped_After) then
2627 Insert_List_Before_And_Analyze (
2628 First (SE.Actions_To_Be_Wrapped_After), L);
2631 SE.Actions_To_Be_Wrapped_After := L;
2633 if Is_List_Member (SE.Node_To_Be_Wrapped) then
2634 Set_Parent (L, Parent (SE.Node_To_Be_Wrapped));
2636 Set_Parent (L, SE.Node_To_Be_Wrapped);
2641 end Store_After_Actions_In_Scope;
2643 -----------------------------------
2644 -- Store_Before_Actions_In_Scope --
2645 -----------------------------------
2647 procedure Store_Before_Actions_In_Scope (L : List_Id) is
2648 SE : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
2651 if Present (SE.Actions_To_Be_Wrapped_Before) then
2652 Insert_List_After_And_Analyze (
2653 Last (SE.Actions_To_Be_Wrapped_Before), L);
2656 SE.Actions_To_Be_Wrapped_Before := L;
2658 if Is_List_Member (SE.Node_To_Be_Wrapped) then
2659 Set_Parent (L, Parent (SE.Node_To_Be_Wrapped));
2661 Set_Parent (L, SE.Node_To_Be_Wrapped);
2666 end Store_Before_Actions_In_Scope;
2668 --------------------------------
2669 -- Wrap_Transient_Declaration --
2670 --------------------------------
2672 -- If a transient scope has been established during the processing of the
2673 -- Expression of an Object_Declaration, it is not possible to wrap the
2674 -- declaration into a transient block as usual case, otherwise the object
2675 -- would be itself declared in the wrong scope. Therefore, all entities (if
2676 -- any) defined in the transient block are moved to the proper enclosing
2677 -- scope, furthermore, if they are controlled variables they are finalized
2678 -- right after the declaration. The finalization list of the transient
2679 -- scope is defined as a renaming of the enclosing one so during their
2680 -- initialization they will be attached to the proper finalization
2681 -- list. For instance, the following declaration :
2683 -- X : Typ := F (G (A), G (B));
2685 -- (where G(A) and G(B) return controlled values, expanded as _v1 and _v2)
2686 -- is expanded into :
2688 -- _local_final_list_1 : Finalizable_Ptr;
2689 -- X : Typ := [ complex Expression-Action ];
2690 -- Finalize_One(_v1);
2691 -- Finalize_One (_v2);
2693 procedure Wrap_Transient_Declaration (N : Node_Id) is
2695 LC : Entity_Id := Empty;
2697 Loc : constant Source_Ptr := Sloc (N);
2698 Enclosing_S : Entity_Id;
2700 Next_N : constant Node_Id := Next (N);
2704 Enclosing_S := Scope (S);
2706 -- Insert Actions kept in the Scope stack
2708 Insert_Actions_In_Scope_Around (N);
2710 -- If the declaration is consuming some secondary stack, mark the
2711 -- Enclosing scope appropriately.
2713 Uses_SS := Uses_Sec_Stack (S);
2716 -- Create a List controller and rename the final list to be its
2717 -- internal final pointer:
2718 -- Lxxx : Simple_List_Controller;
2719 -- Fxxx : Finalizable_Ptr renames Lxxx.F;
2721 if Present (Finalization_Chain_Entity (S)) then
2722 LC := Make_Defining_Identifier (Loc, New_Internal_Name ('L'));
2725 Make_Object_Declaration (Loc,
2726 Defining_Identifier => LC,
2727 Object_Definition =>
2728 New_Reference_To (RTE (RE_Simple_List_Controller), Loc)),
2730 Make_Object_Renaming_Declaration (Loc,
2731 Defining_Identifier => Finalization_Chain_Entity (S),
2732 Subtype_Mark => New_Reference_To (RTE (RE_Finalizable_Ptr), Loc),
2734 Make_Selected_Component (Loc,
2735 Prefix => New_Reference_To (LC, Loc),
2736 Selector_Name => Make_Identifier (Loc, Name_F))));
2738 -- Put the declaration at the beginning of the declaration part
2739 -- to make sure it will be before all other actions that have been
2740 -- inserted before N.
2742 Insert_List_Before_And_Analyze (First (List_Containing (N)), Nodes);
2744 -- Generate the Finalization calls by finalizing the list
2745 -- controller right away. It will be re-finalized on scope
2746 -- exit but it doesn't matter. It cannot be done when the
2747 -- call initializes a renaming object though because in this
2748 -- case, the object becomes a pointer to the temporary and thus
2749 -- increases its life span.
2751 if Nkind (N) = N_Object_Renaming_Declaration
2752 and then Controlled_Type (Etype (Defining_Identifier (N)))
2759 Ref => New_Reference_To (LC, Loc),
2761 With_Detach => New_Reference_To (Standard_False, Loc));
2762 if Present (Next_N) then
2763 Insert_List_Before_And_Analyze (Next_N, Nodes);
2765 Append_List_To (List_Containing (N), Nodes);
2770 -- Put the local entities back in the enclosing scope, and set the
2771 -- Is_Public flag appropriately.
2773 Transfer_Entities (S, Enclosing_S);
2775 -- Mark the enclosing dynamic scope so that the sec stack will be
2776 -- released upon its exit unless this is a function that returns on
2777 -- the sec stack in which case this will be done by the caller.
2780 S := Enclosing_Dynamic_Scope (S);
2782 if Ekind (S) = E_Function
2783 and then Requires_Transient_Scope (Etype (S))
2787 Set_Uses_Sec_Stack (S);
2788 Check_Restriction (No_Secondary_Stack, N);
2791 end Wrap_Transient_Declaration;
2793 -------------------------------
2794 -- Wrap_Transient_Expression --
2795 -------------------------------
2797 -- Insert actions before <Expression>:
2799 -- (lines marked with <CTRL> are expanded only in presence of Controlled
2800 -- objects needing finalization)
2804 -- _M : constant Mark_Id := SS_Mark;
2805 -- Local_Final_List : System.FI.Finalizable_Ptr; <CTRL>
2807 -- procedure _Clean is
2810 -- System.FI.Finalize_List (Local_Final_List); <CTRL>
2816 -- _E := <Expression>;
2821 -- then expression is replaced by _E
2823 procedure Wrap_Transient_Expression (N : Node_Id) is
2824 Loc : constant Source_Ptr := Sloc (N);
2825 E : constant Entity_Id :=
2826 Make_Defining_Identifier (Loc, New_Internal_Name ('E'));
2827 Etyp : Entity_Id := Etype (N);
2830 Insert_Actions (N, New_List (
2831 Make_Object_Declaration (Loc,
2832 Defining_Identifier => E,
2833 Object_Definition => New_Reference_To (Etyp, Loc)),
2835 Make_Transient_Block (Loc,
2837 Make_Assignment_Statement (Loc,
2838 Name => New_Reference_To (E, Loc),
2839 Expression => Relocate_Node (N)))));
2841 Rewrite (N, New_Reference_To (E, Loc));
2842 Analyze_And_Resolve (N, Etyp);
2843 end Wrap_Transient_Expression;
2845 ------------------------------
2846 -- Wrap_Transient_Statement --
2847 ------------------------------
2849 -- Transform <Instruction> into
2851 -- (lines marked with <CTRL> are expanded only in presence of Controlled
2852 -- objects needing finalization)
2855 -- _M : Mark_Id := SS_Mark;
2856 -- Local_Final_List : System.FI.Finalizable_Ptr ; <CTRL>
2858 -- procedure _Clean is
2861 -- System.FI.Finalize_List (Local_Final_List); <CTRL>
2872 procedure Wrap_Transient_Statement (N : Node_Id) is
2873 Loc : constant Source_Ptr := Sloc (N);
2874 New_Statement : constant Node_Id := Relocate_Node (N);
2877 Rewrite (N, Make_Transient_Block (Loc, New_Statement));
2879 -- With the scope stack back to normal, we can call analyze on the
2880 -- resulting block. At this point, the transient scope is being
2881 -- treated like a perfectly normal scope, so there is nothing
2882 -- special about it.
2884 -- Note: Wrap_Transient_Statement is called with the node already
2885 -- analyzed (i.e. Analyzed (N) is True). This is important, since
2886 -- otherwise we would get a recursive processing of the node when
2887 -- we do this Analyze call.
2890 end Wrap_Transient_Statement;