1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2003, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 2, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING. If not, write --
19 -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
20 -- MA 02111-1307, USA. --
22 -- GNAT was originally developed by the GNAT team at New York University. --
23 -- Extensive contributions were provided by Ada Core Technologies Inc. --
25 ------------------------------------------------------------------------------
27 -- This package contains virtually all expansion mechanisms related to
31 with Atree; use Atree;
32 with Debug; use Debug;
33 with Einfo; use Einfo;
34 with Errout; use Errout;
35 with Exp_Ch9; use Exp_Ch9;
36 with Exp_Ch11; use Exp_Ch11;
37 with Exp_Dbug; use Exp_Dbug;
38 with Exp_Tss; use Exp_Tss;
39 with Exp_Util; use Exp_Util;
40 with Fname; use Fname;
41 with Freeze; use Freeze;
42 with Hostparm; use Hostparm;
44 with Nlists; use Nlists;
45 with Nmake; use Nmake;
47 with Output; use Output;
48 with Restrict; use Restrict;
49 with Rtsfind; use Rtsfind;
50 with Targparm; use Targparm;
51 with Sinfo; use Sinfo;
53 with Sem_Ch3; use Sem_Ch3;
54 with Sem_Ch7; use Sem_Ch7;
55 with Sem_Ch8; use Sem_Ch8;
56 with Sem_Res; use Sem_Res;
57 with Sem_Type; use Sem_Type;
58 with Sem_Util; use Sem_Util;
59 with Snames; use Snames;
60 with Stand; use Stand;
61 with Tbuild; use Tbuild;
62 with Uintp; use Uintp;
64 package body Exp_Ch7 is
66 --------------------------------
67 -- Transient Scope Management --
68 --------------------------------
70 -- A transient scope is created when temporary objects are created by the
71 -- compiler. These temporary objects are allocated on the secondary stack
72 -- and the transient scope is responsible for finalizing the object when
73 -- appropriate and reclaiming the memory at the right time. The temporary
74 -- objects are generally the objects allocated to store the result of a
75 -- function returning an unconstrained or a tagged value. Expressions
76 -- needing to be wrapped in a transient scope (functions calls returning
77 -- unconstrained or tagged values) may appear in 3 different contexts which
78 -- lead to 3 different kinds of transient scope expansion:
80 -- 1. In a simple statement (procedure call, assignment, ...). In
81 -- this case the instruction is wrapped into a transient block.
82 -- (See Wrap_Transient_Statement for details)
84 -- 2. In an expression of a control structure (test in a IF statement,
85 -- expression in a CASE statement, ...).
86 -- (See Wrap_Transient_Expression for details)
88 -- 3. In a expression of an object_declaration. No wrapping is possible
89 -- here, so the finalization actions, if any are done right after the
90 -- declaration and the secondary stack deallocation is done in the
91 -- proper enclosing scope (see Wrap_Transient_Declaration for details)
93 -- Note about function returning tagged types: It has been decided to
94 -- always allocate their result in the secondary stack while it is not
95 -- absolutely mandatory when the tagged type is constrained because the
96 -- caller knows the size of the returned object and thus could allocate the
97 -- result in the primary stack. But, allocating them always in the
98 -- secondary stack simplifies many implementation hassles:
100 -- - If it is dispatching function call, the computation of the size of
101 -- the result is possible but complex from the outside.
103 -- - If the returned type is controlled, the assignment of the returned
104 -- value to the anonymous object involves an Adjust, and we have no
105 -- easy way to access the anonymous object created by the back-end
107 -- - If the returned type is class-wide, this is an unconstrained type
110 -- Furthermore, the little loss in efficiency which is the result of this
111 -- decision is not such a big deal because function returning tagged types
112 -- are not very much used in real life as opposed to functions returning
113 -- access to a tagged type
115 --------------------------------------------------
116 -- Transient Blocks and Finalization Management --
117 --------------------------------------------------
119 function Find_Node_To_Be_Wrapped (N : Node_Id) return Node_Id;
120 -- N is a node wich may generate a transient scope. Loop over the
121 -- parent pointers of N until it find the appropriate node to
122 -- wrap. It it returns Empty, it means that no transient scope is
123 -- needed in this context.
132 Is_Protected_Subprogram : Boolean;
133 Is_Task_Allocation_Block : Boolean;
134 Is_Asynchronous_Call_Block : Boolean)
136 -- Expand a the clean-up procedure for controlled and/or transient
137 -- block, and/or task master or task body, or blocks used to
138 -- implement task allocation or asynchronous entry calls, or
139 -- procedures used to implement protected procedures. Clean is the
140 -- entity for such a procedure. Mark is the entity for the secondary
141 -- stack mark, if empty only controlled block clean-up will be
142 -- performed. Flist is the entity for the local final list, if empty
143 -- only transient scope clean-up will be performed. The flags
144 -- Is_Task and Is_Master control the calls to the corresponding
145 -- finalization actions for a task body or for an entity that is a
148 procedure Set_Node_To_Be_Wrapped (N : Node_Id);
149 -- Set the field Node_To_Be_Wrapped of the current scope
151 procedure Insert_Actions_In_Scope_Around (N : Node_Id);
152 -- Insert the before-actions kept in the scope stack before N, and the
153 -- after after-actions, after N which must be a member of a list.
155 function Make_Transient_Block
159 -- Create a transient block whose name is Scope, which is also a
160 -- controlled block if Flist is not empty and whose only code is
161 -- Action (either a single statement or single declaration).
163 type Final_Primitives is (Initialize_Case, Adjust_Case, Finalize_Case);
164 -- This enumeration type is defined in order to ease sharing code for
165 -- building finalization procedures for composite types.
167 Name_Of : constant array (Final_Primitives) of Name_Id :=
168 (Initialize_Case => Name_Initialize,
169 Adjust_Case => Name_Adjust,
170 Finalize_Case => Name_Finalize);
172 Deep_Name_Of : constant array (Final_Primitives) of TSS_Name_Type :=
173 (Initialize_Case => TSS_Deep_Initialize,
174 Adjust_Case => TSS_Deep_Adjust,
175 Finalize_Case => TSS_Deep_Finalize);
177 procedure Build_Record_Deep_Procs (Typ : Entity_Id);
178 -- Build the deep Initialize/Adjust/Finalize for a record Typ with
179 -- Has_Component_Component set and store them using the TSS mechanism.
181 procedure Build_Array_Deep_Procs (Typ : Entity_Id);
182 -- Build the deep Initialize/Adjust/Finalize for a record Typ with
183 -- Has_Controlled_Component set and store them using the TSS mechanism.
185 function Make_Deep_Proc
186 (Prim : Final_Primitives;
190 -- This function generates the tree for Deep_Initialize, Deep_Adjust
191 -- or Deep_Finalize procedures according to the first parameter,
192 -- these procedures operate on the type Typ. The Stmts parameter
193 -- gives the body of the procedure.
195 function Make_Deep_Array_Body
196 (Prim : Final_Primitives;
199 -- This function generates the list of statements for implementing
200 -- Deep_Initialize, Deep_Adjust or Deep_Finalize procedures
201 -- according to the first parameter, these procedures operate on the
204 function Make_Deep_Record_Body
205 (Prim : Final_Primitives;
208 -- This function generates the list of statements for implementing
209 -- Deep_Initialize, Deep_Adjust or Deep_Finalize procedures
210 -- according to the first parameter, these procedures operate on the
213 procedure Check_Visibly_Controlled
214 (Prim : Final_Primitives;
216 E : in out Entity_Id;
217 Cref : in out Node_Id);
218 -- The controlled operation declared for a derived type may not be
219 -- overriding, if the controlled operations of the parent type are
220 -- hidden, for example when the parent is a private type whose full
221 -- view is controlled. For other primitive operations we modify the
222 -- name of the operation to indicate that it is not overriding, but
223 -- this is not possible for Initialize, etc. because they have to be
224 -- retrievable by name. Before generating the proper call to one of
225 -- these operations we check whether Typ is known to be controlled at
226 -- the point of definition. If it is not then we must retrieve the
227 -- hidden operation of the parent and use it instead. This is one
228 -- case that might be solved more cleanly once Overriding pragmas or
229 -- declarations are in place.
231 function Convert_View
236 -- Proc is one of the Initialize/Adjust/Finalize operations, and
237 -- Arg is the argument being passed to it. Ind indicates which
238 -- formal of procedure Proc we are trying to match. This function
239 -- will, if necessary, generate an conversion between the partial
240 -- and full view of Arg to match the type of the formal of Proc,
241 -- or force a conversion to the class-wide type in the case where
242 -- the operation is abstract.
244 -----------------------------
245 -- Finalization Management --
246 -----------------------------
248 -- This part describe how Initialization/Adjusment/Finalization procedures
249 -- are generated and called. Two cases must be considered, types that are
250 -- Controlled (Is_Controlled flag set) and composite types that contain
251 -- controlled components (Has_Controlled_Component flag set). In the first
252 -- case the procedures to call are the user-defined primitive operations
253 -- Initialize/Adjust/Finalize. In the second case, GNAT generates
254 -- Deep_Initialize, Deep_Adjust and Deep_Finalize that are in charge of
255 -- calling the former procedures on the controlled components.
257 -- For records with Has_Controlled_Component set, a hidden "controller"
258 -- component is inserted. This controller component contains its own
259 -- finalization list on which all controlled components are attached
260 -- creating an indirection on the upper-level Finalization list. This
261 -- technique facilitates the management of objects whose number of
262 -- controlled components changes during execution. This controller
263 -- component is itself controlled and is attached to the upper-level
264 -- finalization chain. Its adjust primitive is in charge of calling
265 -- adjust on the components and adusting the finalization pointer to
266 -- match their new location (see a-finali.adb).
268 -- It is not possible to use a similar technique for arrays that have
269 -- Has_Controlled_Component set. In this case, deep procedures are
270 -- generated that call initialize/adjust/finalize + attachment or
271 -- detachment on the finalization list for all component.
273 -- Initialize calls: they are generated for declarations or dynamic
274 -- allocations of Controlled objects with no initial value. They are
275 -- always followed by an attachment to the current Finalization
276 -- Chain. For the dynamic allocation case this the chain attached to
277 -- the scope of the access type definition otherwise, this is the chain
278 -- of the current scope.
280 -- Adjust Calls: They are generated on 2 occasions: (1) for
281 -- declarations or dynamic allocations of Controlled objects with an
282 -- initial value. (2) after an assignment. In the first case they are
283 -- followed by an attachment to the final chain, in the second case
286 -- Finalization Calls: They are generated on (1) scope exit, (2)
287 -- assignments, (3) unchecked deallocations. In case (3) they have to
288 -- be detached from the final chain, in case (2) they must not and in
289 -- case (1) this is not important since we are exiting the scope
293 -- - Type extensions will have a new record controller at each derivation
294 -- level containing controlled components.
295 -- - For types that are both Is_Controlled and Has_Controlled_Components,
296 -- the record controller and the object itself are handled separately.
297 -- It could seem simpler to attach the object at the end of its record
298 -- controller but this would not tackle view conversions properly.
299 -- - A classwide type can always potentially have controlled components
300 -- but the record controller of the corresponding actual type may not
301 -- be nown at compile time so the dispatch table contains a special
302 -- field that allows to compute the offset of the record controller
303 -- dynamically. See s-finimp.Deep_Tag_Attach and a-tags.RC_Offset
305 -- Here is a simple example of the expansion of a controlled block :
309 -- Y : Controlled := Init;
315 -- Z : R := (C => X);
324 -- _L : System.FI.Finalizable_Ptr;
326 -- procedure _Clean is
329 -- System.FI.Finalize_List (_L);
337 -- Attach_To_Final_List (_L, Finalizable (X), 1);
338 -- at end: Abort_Undefer;
339 -- Y : Controlled := Init;
341 -- Attach_To_Final_List (_L, Finalizable (Y), 1);
344 -- _C : Record_Controller;
350 -- Deep_Initialize (W, _L, 1);
351 -- at end: Abort_Under;
352 -- Z : R := (C => X);
353 -- Deep_Adjust (Z, _L, 1);
357 -- Deep_Finalize (W, False);
358 -- <save W's final pointers>
360 -- <restore W's final pointers>
361 -- Deep_Adjust (W, _L, 0);
366 function Global_Flist_Ref (Flist_Ref : Node_Id) return Boolean;
367 -- Return True if Flist_Ref refers to a global final list, either
368 -- the object GLobal_Final_List which is used to attach standalone
369 -- objects, or any of the list controllers associated with library
370 -- level access to controlled objects
372 procedure Clean_Simple_Protected_Objects (N : Node_Id);
373 -- Protected objects without entries are not controlled types, and the
374 -- locks have to be released explicitly when such an object goes out
375 -- of scope. Traverse declarations in scope to determine whether such
376 -- objects are present.
378 ----------------------------
379 -- Build_Array_Deep_Procs --
380 ----------------------------
382 procedure Build_Array_Deep_Procs (Typ : Entity_Id) is
386 Prim => Initialize_Case,
388 Stmts => Make_Deep_Array_Body (Initialize_Case, Typ)));
390 if not Is_Return_By_Reference_Type (Typ) then
395 Stmts => Make_Deep_Array_Body (Adjust_Case, Typ)));
400 Prim => Finalize_Case,
402 Stmts => Make_Deep_Array_Body (Finalize_Case, Typ)));
403 end Build_Array_Deep_Procs;
405 -----------------------------
406 -- Build_Controlling_Procs --
407 -----------------------------
409 procedure Build_Controlling_Procs (Typ : Entity_Id) is
411 if Is_Array_Type (Typ) then
412 Build_Array_Deep_Procs (Typ);
414 else pragma Assert (Is_Record_Type (Typ));
415 Build_Record_Deep_Procs (Typ);
417 end Build_Controlling_Procs;
419 ----------------------
420 -- Build_Final_List --
421 ----------------------
423 procedure Build_Final_List (N : Node_Id; Typ : Entity_Id) is
424 Loc : constant Source_Ptr := Sloc (N);
428 Set_Associated_Final_Chain (Typ,
429 Make_Defining_Identifier (Loc,
430 New_External_Name (Chars (Typ), 'L')));
433 Make_Object_Declaration (Loc,
434 Defining_Identifier =>
435 Associated_Final_Chain (Typ),
438 (RTE (RE_List_Controller), Loc));
440 -- The type may have been frozen already, and this is a late freezing
441 -- action, in which case the declaration must be elaborated at once.
442 -- If the call is for an allocator, the chain must also be created now,
443 -- because the freezing of the type does not build one. Otherwise, the
444 -- declaration is one of the freezing actions for a user-defined type.
447 or else (Nkind (N) = N_Allocator
448 and then Ekind (Etype (N)) = E_Anonymous_Access_Type)
450 Insert_Action (N, Decl);
452 Append_Freeze_Action (Typ, Decl);
454 end Build_Final_List;
456 ---------------------
457 -- Build_Late_Proc --
458 ---------------------
460 procedure Build_Late_Proc (Typ : Entity_Id; Nam : Name_Id) is
462 for Final_Prim in Name_Of'Range loop
463 if Name_Of (Final_Prim) = Nam then
468 Stmts => Make_Deep_Record_Body (Final_Prim, Typ)));
473 -----------------------------
474 -- Build_Record_Deep_Procs --
475 -----------------------------
477 procedure Build_Record_Deep_Procs (Typ : Entity_Id) is
481 Prim => Initialize_Case,
483 Stmts => Make_Deep_Record_Body (Initialize_Case, Typ)));
485 if not Is_Return_By_Reference_Type (Typ) then
490 Stmts => Make_Deep_Record_Body (Adjust_Case, Typ)));
495 Prim => Finalize_Case,
497 Stmts => Make_Deep_Record_Body (Finalize_Case, Typ)));
498 end Build_Record_Deep_Procs;
504 function Cleanup_Array
510 Loc : constant Source_Ptr := Sloc (N);
511 Index_List : List_Id := New_List;
513 function Free_Component return List_Id;
514 -- Generate the code to finalize the task or protected subcomponents
515 -- of a single component of the array.
517 function Free_One_Dimension (Dim : Int) return List_Id;
518 -- Generate a loop over one dimension of the array.
524 function Free_Component return List_Id is
525 Stmts : List_Id := New_List;
527 C_Typ : Entity_Id := Component_Type (Typ);
530 -- Component type is known to contain tasks or protected objects
533 Make_Indexed_Component (Loc,
534 Prefix => Duplicate_Subexpr_No_Checks (Obj),
535 Expressions => Index_List);
537 Set_Etype (Tsk, C_Typ);
539 if Is_Task_Type (C_Typ) then
540 Append_To (Stmts, Cleanup_Task (N, Tsk));
542 elsif Is_Simple_Protected_Type (C_Typ) then
543 Append_To (Stmts, Cleanup_Protected_Object (N, Tsk));
545 elsif Is_Record_Type (C_Typ) then
546 Stmts := Cleanup_Record (N, Tsk, C_Typ);
548 elsif Is_Array_Type (C_Typ) then
549 Stmts := Cleanup_Array (N, Tsk, C_Typ);
555 ------------------------
556 -- Free_One_Dimension --
557 ------------------------
559 function Free_One_Dimension (Dim : Int) return List_Id is
563 if Dim > Number_Dimensions (Typ) then
564 return Free_Component;
566 -- Here we generate the required loop
570 Make_Defining_Identifier (Loc, New_Internal_Name ('J'));
572 Append (New_Reference_To (Index, Loc), Index_List);
575 Make_Implicit_Loop_Statement (N,
578 Make_Iteration_Scheme (Loc,
579 Loop_Parameter_Specification =>
580 Make_Loop_Parameter_Specification (Loc,
581 Defining_Identifier => Index,
582 Discrete_Subtype_Definition =>
583 Make_Attribute_Reference (Loc,
584 Prefix => Duplicate_Subexpr (Obj),
585 Attribute_Name => Name_Range,
586 Expressions => New_List (
587 Make_Integer_Literal (Loc, Dim))))),
588 Statements => Free_One_Dimension (Dim + 1)));
590 end Free_One_Dimension;
592 -- Start of processing for Cleanup_Array
595 return Free_One_Dimension (1);
602 function Cleanup_Record
608 Loc : constant Source_Ptr := Sloc (N);
611 Stmts : List_Id := New_List;
612 U_Typ : constant Entity_Id := Underlying_Type (Typ);
615 if Has_Discriminants (U_Typ)
616 and then Nkind (Parent (U_Typ)) = N_Full_Type_Declaration
618 Nkind (Type_Definition (Parent (U_Typ))) = N_Record_Definition
622 (Component_List (Type_Definition (Parent (U_Typ)))))
624 -- For now, do not attempt to free a component that may appear in
625 -- a variant, and instead issue a warning. Doing this "properly"
626 -- would require building a case statement and would be quite a
627 -- mess. Note that the RM only requires that free "work" for the
628 -- case of a task access value, so already we go way beyond this
629 -- in that we deal with the array case and non-discriminated
633 ("task/protected object in variant record will not be freed?", N);
634 return New_List (Make_Null_Statement (Loc));
637 Comp := First_Component (Typ);
639 while Present (Comp) loop
640 if Has_Task (Etype (Comp))
641 or else Has_Simple_Protected_Object (Etype (Comp))
644 Make_Selected_Component (Loc,
645 Prefix => Duplicate_Subexpr_No_Checks (Obj),
646 Selector_Name => New_Occurrence_Of (Comp, Loc));
647 Set_Etype (Tsk, Etype (Comp));
649 if Is_Task_Type (Etype (Comp)) then
650 Append_To (Stmts, Cleanup_Task (N, Tsk));
652 elsif Is_Simple_Protected_Type (Etype (Comp)) then
653 Append_To (Stmts, Cleanup_Protected_Object (N, Tsk));
655 elsif Is_Record_Type (Etype (Comp)) then
657 -- Recurse, by generating the prefix of the argument to
658 -- the eventual cleanup call.
661 (Stmts, Cleanup_Record (N, Tsk, Etype (Comp)));
663 elsif Is_Array_Type (Etype (Comp)) then
665 (Stmts, Cleanup_Array (N, Tsk, Etype (Comp)));
669 Next_Component (Comp);
675 -------------------------------
676 -- Cleanup_Protected_Object --
677 -------------------------------
679 function Cleanup_Protected_Object
684 Loc : constant Source_Ptr := Sloc (N);
688 Make_Procedure_Call_Statement (Loc,
689 Name => New_Reference_To (RTE (RE_Finalize_Protection), Loc),
690 Parameter_Associations => New_List (
691 Concurrent_Ref (Ref)));
692 end Cleanup_Protected_Object;
694 ------------------------------------
695 -- Clean_Simple_Protected_Objects --
696 ------------------------------------
698 procedure Clean_Simple_Protected_Objects (N : Node_Id) is
700 Stmts : List_Id := Statements (Handled_Statement_Sequence (N));
701 Stmt : Node_Id := Last (Stmts);
704 E := First_Entity (Current_Scope);
706 while Present (E) loop
707 if (Ekind (E) = E_Variable
708 or else Ekind (E) = E_Constant)
709 and then Has_Simple_Protected_Object (Etype (E))
710 and then not Has_Task (Etype (E))
713 Typ : constant Entity_Id := Etype (E);
714 Ref : constant Node_Id := New_Occurrence_Of (E, Sloc (Stmt));
717 if Is_Simple_Protected_Type (Typ) then
718 Append_To (Stmts, Cleanup_Protected_Object (N, Ref));
720 elsif Has_Simple_Protected_Object (Typ) then
721 if Is_Record_Type (Typ) then
722 Append_List_To (Stmts, Cleanup_Record (N, Ref, Typ));
724 elsif Is_Array_Type (Typ) then
725 Append_List_To (Stmts, Cleanup_Array (N, Ref, Typ));
734 -- Analyze inserted cleanup statements.
736 if Present (Stmt) then
739 while Present (Stmt) loop
744 end Clean_Simple_Protected_Objects;
750 function Cleanup_Task
755 Loc : constant Source_Ptr := Sloc (N);
758 Make_Procedure_Call_Statement (Loc,
759 Name => New_Reference_To (RTE (RE_Free_Task), Loc),
760 Parameter_Associations =>
761 New_List (Concurrent_Ref (Ref)));
764 ---------------------------------
765 -- Has_Simple_Protected_Object --
766 ---------------------------------
768 function Has_Simple_Protected_Object (T : Entity_Id) return Boolean is
772 if Is_Simple_Protected_Type (T) then
775 elsif Is_Array_Type (T) then
776 return Has_Simple_Protected_Object (Component_Type (T));
778 elsif Is_Record_Type (T) then
779 Comp := First_Component (T);
781 while Present (Comp) loop
782 if Has_Simple_Protected_Object (Etype (Comp)) then
786 Next_Component (Comp);
794 end Has_Simple_Protected_Object;
796 ------------------------------
797 -- Is_Simple_Protected_Type --
798 ------------------------------
800 function Is_Simple_Protected_Type (T : Entity_Id) return Boolean is
802 return Is_Protected_Type (T) and then not Has_Entries (T);
803 end Is_Simple_Protected_Type;
805 ------------------------------
806 -- Check_Visibly_Controlled --
807 ------------------------------
809 procedure Check_Visibly_Controlled
810 (Prim : Final_Primitives;
812 E : in out Entity_Id;
813 Cref : in out Node_Id)
815 Parent_Type : Entity_Id;
819 if Is_Derived_Type (Typ)
820 and then Comes_From_Source (E)
821 and then Is_Overriding_Operation (E)
823 (not Is_Predefined_File_Name
824 (Unit_File_Name (Get_Source_Unit (Root_Type (Typ)))))
826 -- We know that the explicit operation on the type overrode
827 -- the inherited operation of the parent, and that the derivation
828 -- is from a private type that is not visibly controlled.
830 Parent_Type := Etype (Typ);
831 Op := Find_Prim_Op (Parent_Type, Name_Of (Prim));
834 and then Is_Hidden (Op)
835 and then Scope (Scope (Typ)) /= Scope (Op)
836 and then not In_Open_Scopes (Scope (Typ))
838 -- If the parent operation is not visible, and the derived
839 -- type is not declared in a child unit, then the explicit
840 -- operation does not override, and we must use the operation
845 -- Wrap the object to be initialized into the proper
846 -- unchecked conversion, to be compatible with the operation
849 if Nkind (Cref) = N_Unchecked_Type_Conversion then
850 Cref := Unchecked_Convert_To (Parent_Type, Expression (Cref));
852 Cref := Unchecked_Convert_To (Parent_Type, Cref);
856 end Check_Visibly_Controlled;
858 ---------------------
859 -- Controlled_Type --
860 ---------------------
862 function Controlled_Type (T : Entity_Id) return Boolean is
864 function Has_Some_Controlled_Component (Rec : Entity_Id) return Boolean;
865 -- If type is not frozen yet, check explicitly among its components,
866 -- because flag is not necessarily set.
868 ------------------------------------
869 -- Has_Some_Controlled_Component --
870 ------------------------------------
872 function Has_Some_Controlled_Component (Rec : Entity_Id)
878 if Has_Controlled_Component (Rec) then
881 elsif not Is_Frozen (Rec) then
882 if Is_Record_Type (Rec) then
883 Comp := First_Entity (Rec);
885 while Present (Comp) loop
886 if not Is_Type (Comp)
887 and then Controlled_Type (Etype (Comp))
897 elsif Is_Array_Type (Rec) then
898 return Is_Controlled (Component_Type (Rec));
901 return Has_Controlled_Component (Rec);
906 end Has_Some_Controlled_Component;
908 -- Start of processing for Controlled_Type
911 -- Class-wide types must be treated as controlled because they may
912 -- contain an extension that has controlled components
914 -- We can skip this if finalization is not available
916 return (Is_Class_Wide_Type (T)
917 and then not In_Finalization_Root (T)
918 and then not Restrictions (No_Finalization))
919 or else Is_Controlled (T)
920 or else Has_Some_Controlled_Component (T)
921 or else (Is_Concurrent_Type (T)
922 and then Present (Corresponding_Record_Type (T))
923 and then Controlled_Type (Corresponding_Record_Type (T)));
926 --------------------------
927 -- Controller_Component --
928 --------------------------
930 function Controller_Component (Typ : Entity_Id) return Entity_Id is
931 T : Entity_Id := Base_Type (Typ);
933 Comp_Scop : Entity_Id;
934 Res : Entity_Id := Empty;
935 Res_Scop : Entity_Id := Empty;
938 if Is_Class_Wide_Type (T) then
942 if Is_Private_Type (T) then
943 T := Underlying_Type (T);
946 -- Fetch the outermost controller
948 Comp := First_Entity (T);
949 while Present (Comp) loop
950 if Chars (Comp) = Name_uController then
951 Comp_Scop := Scope (Original_Record_Component (Comp));
953 -- If this controller is at the outermost level, no need to
954 -- look for another one
956 if Comp_Scop = T then
959 -- Otherwise record the outermost one and continue looking
961 elsif Res = Empty or else Is_Ancestor (Res_Scop, Comp_Scop) then
963 Res_Scop := Comp_Scop;
970 -- If we fall through the loop, there is no controller component
973 end Controller_Component;
979 function Convert_View
985 Fent : Entity_Id := First_Entity (Proc);
990 for J in 2 .. Ind loop
994 Ftyp := Etype (Fent);
996 if Nkind (Arg) = N_Type_Conversion
997 or else Nkind (Arg) = N_Unchecked_Type_Conversion
999 Atyp := Entity (Subtype_Mark (Arg));
1001 Atyp := Etype (Arg);
1004 if Is_Abstract (Proc) and then Is_Tagged_Type (Ftyp) then
1005 return Unchecked_Convert_To (Class_Wide_Type (Ftyp), Arg);
1008 and then Present (Atyp)
1010 (Is_Private_Type (Ftyp) or else Is_Private_Type (Atyp))
1011 and then Underlying_Type (Atyp) = Underlying_Type (Ftyp)
1013 return Unchecked_Convert_To (Ftyp, Arg);
1015 -- If the argument is already a conversion, as generated by
1016 -- Make_Init_Call, set the target type to the type of the formal
1017 -- directly, to avoid spurious typing problems.
1019 elsif (Nkind (Arg) = N_Unchecked_Type_Conversion
1020 or else Nkind (Arg) = N_Type_Conversion)
1021 and then not Is_Class_Wide_Type (Atyp)
1023 Set_Subtype_Mark (Arg, New_Occurrence_Of (Ftyp, Sloc (Arg)));
1024 Set_Etype (Arg, Ftyp);
1032 -------------------------------
1033 -- Establish_Transient_Scope --
1034 -------------------------------
1036 -- This procedure is called each time a transient block has to be inserted
1037 -- that is to say for each call to a function with unconstrained ot tagged
1038 -- result. It creates a new scope on the stack scope in order to enclose
1039 -- all transient variables generated
1041 procedure Establish_Transient_Scope (N : Node_Id; Sec_Stack : Boolean) is
1042 Loc : constant Source_Ptr := Sloc (N);
1043 Wrap_Node : Node_Id;
1045 Sec_Stk : constant Boolean :=
1046 Sec_Stack and not Functions_Return_By_DSP_On_Target;
1047 -- We never need a secondary stack if functions return by DSP
1050 -- Do not create a transient scope if we are already inside one
1052 for S in reverse Scope_Stack.First .. Scope_Stack.Last loop
1054 if Scope_Stack.Table (S).Is_Transient then
1056 Set_Uses_Sec_Stack (Scope_Stack.Table (S).Entity);
1061 -- If we have encountered Standard there are no enclosing
1062 -- transient scopes.
1064 elsif Scope_Stack.Table (S).Entity = Standard_Standard then
1070 Wrap_Node := Find_Node_To_Be_Wrapped (N);
1072 -- Case of no wrap node, false alert, no transient scope needed
1074 if No (Wrap_Node) then
1077 -- Transient scope is required
1080 New_Scope (New_Internal_Entity (E_Block, Current_Scope, Loc, 'B'));
1081 Set_Scope_Is_Transient;
1084 Set_Uses_Sec_Stack (Current_Scope);
1085 Check_Restriction (No_Secondary_Stack, N);
1088 Set_Etype (Current_Scope, Standard_Void_Type);
1089 Set_Node_To_Be_Wrapped (Wrap_Node);
1091 if Debug_Flag_W then
1092 Write_Str (" <Transient>");
1096 end Establish_Transient_Scope;
1098 ----------------------------
1099 -- Expand_Cleanup_Actions --
1100 ----------------------------
1102 procedure Expand_Cleanup_Actions (N : Node_Id) is
1104 S : constant Entity_Id :=
1106 Flist : constant Entity_Id :=
1107 Finalization_Chain_Entity (S);
1108 Is_Task : constant Boolean :=
1109 (Nkind (Original_Node (N)) = N_Task_Body);
1110 Is_Master : constant Boolean :=
1111 Nkind (N) /= N_Entry_Body
1112 and then Is_Task_Master (N);
1113 Is_Protected : constant Boolean :=
1114 Nkind (N) = N_Subprogram_Body
1115 and then Is_Protected_Subprogram_Body (N);
1116 Is_Task_Allocation : constant Boolean :=
1117 Nkind (N) = N_Block_Statement
1118 and then Is_Task_Allocation_Block (N);
1119 Is_Asynchronous_Call : constant Boolean :=
1120 Nkind (N) = N_Block_Statement
1121 and then Is_Asynchronous_Call_Block (N);
1124 Mark : Entity_Id := Empty;
1125 New_Decls : constant List_Id := New_List;
1128 Chain : Entity_Id := Empty;
1134 -- Compute a location that is not directly in the user code in
1135 -- order to avoid to generate confusing debug info. A good
1136 -- approximation is the name of the outer user-defined scope
1139 S1 : Entity_Id := S;
1142 while not Comes_From_Source (S1) and then S1 /= Standard_Standard loop
1149 -- There are cleanup actions only if the secondary stack needs
1150 -- releasing or some finalizations are needed or in the context
1153 if Uses_Sec_Stack (Current_Scope)
1154 and then not Sec_Stack_Needed_For_Return (Current_Scope)
1158 and then not Is_Master
1159 and then not Is_Task
1160 and then not Is_Protected
1161 and then not Is_Task_Allocation
1162 and then not Is_Asynchronous_Call
1164 Clean_Simple_Protected_Objects (N);
1168 -- If the current scope is the subprogram body that is the rewriting
1169 -- of a task body, and the descriptors have not been delayed (due to
1170 -- some nested instantiations) do not generate redundant cleanup
1171 -- actions: the cleanup procedure already exists for this body.
1173 if Nkind (N) = N_Subprogram_Body
1174 and then Nkind (Original_Node (N)) = N_Task_Body
1175 and then not Delay_Subprogram_Descriptors (Corresponding_Spec (N))
1180 -- Set polling off, since we don't need to poll during cleanup
1181 -- actions, and indeed for the cleanup routine, which is executed
1182 -- with aborts deferred, we don't want polling.
1184 Old_Poll := Polling_Required;
1185 Polling_Required := False;
1187 -- Make sure we have a declaration list, since we will add to it
1189 if No (Declarations (N)) then
1190 Set_Declarations (N, New_List);
1193 -- The task activation call has already been built for task
1194 -- allocation blocks.
1196 if not Is_Task_Allocation then
1197 Build_Task_Activation_Call (N);
1201 Establish_Task_Master (N);
1204 -- If secondary stack is in use, expand:
1205 -- _Mxx : constant Mark_Id := SS_Mark;
1207 -- Suppress calls to SS_Mark and SS_Release if Java_VM,
1208 -- since we never use the secondary stack on the JVM.
1210 if Uses_Sec_Stack (Current_Scope)
1211 and then not Sec_Stack_Needed_For_Return (Current_Scope)
1212 and then not Java_VM
1214 Mark := Make_Defining_Identifier (Loc, New_Internal_Name ('M'));
1215 Append_To (New_Decls,
1216 Make_Object_Declaration (Loc,
1217 Defining_Identifier => Mark,
1218 Object_Definition => New_Reference_To (RTE (RE_Mark_Id), Loc),
1220 Make_Function_Call (Loc,
1221 Name => New_Reference_To (RTE (RE_SS_Mark), Loc))));
1223 Set_Uses_Sec_Stack (Current_Scope, False);
1226 -- If finalization list is present then expand:
1227 -- Local_Final_List : System.FI.Finalizable_Ptr;
1229 if Present (Flist) then
1230 Append_To (New_Decls,
1231 Make_Object_Declaration (Loc,
1232 Defining_Identifier => Flist,
1233 Object_Definition =>
1234 New_Reference_To (RTE (RE_Finalizable_Ptr), Loc)));
1237 -- Clean-up procedure definition
1239 Clean := Make_Defining_Identifier (Loc, Name_uClean);
1240 Set_Suppress_Elaboration_Warnings (Clean);
1241 Append_To (New_Decls,
1242 Make_Clean (N, Clean, Mark, Flist,
1247 Is_Asynchronous_Call));
1249 -- If exception handlers are present, wrap the Sequence of
1250 -- statements in a block because it is not possible to get
1251 -- exception handlers and an AT END call in the same scope.
1253 if Present (Exception_Handlers (Handled_Statement_Sequence (N))) then
1255 Make_Block_Statement (Loc,
1256 Handled_Statement_Sequence => Handled_Statement_Sequence (N));
1257 Set_Handled_Statement_Sequence (N,
1258 Make_Handled_Sequence_Of_Statements (Loc, New_List (Blok)));
1261 -- Otherwise we do not wrap
1268 -- Don't move the _chain Activation_Chain declaration in task
1269 -- allocation blocks. Task allocation blocks use this object
1270 -- in their cleanup handlers, and gigi complains if it is declared
1271 -- in the sequence of statements of the scope that declares the
1274 if Is_Task_Allocation then
1275 Chain := Activation_Chain_Entity (N);
1276 Decl := First (Declarations (N));
1278 while Nkind (Decl) /= N_Object_Declaration
1279 or else Defining_Identifier (Decl) /= Chain
1282 pragma Assert (Present (Decl));
1286 Prepend_To (New_Decls, Decl);
1289 -- Now we move the declarations into the Sequence of statements
1290 -- in order to get them protected by the AT END call. It may seem
1291 -- weird to put declarations in the sequence of statement but in
1292 -- fact nothing forbids that at the tree level. We also set the
1293 -- First_Real_Statement field so that we remember where the real
1294 -- statements (i.e. original statements) begin. Note that if we
1295 -- wrapped the statements, the first real statement is inside the
1296 -- inner block. If the First_Real_Statement is already set (as is
1297 -- the case for subprogram bodies that are expansions of task bodies)
1298 -- then do not reset it, because its declarative part would migrate
1299 -- to the statement part.
1302 if No (First_Real_Statement (Handled_Statement_Sequence (N))) then
1303 Set_First_Real_Statement (Handled_Statement_Sequence (N),
1304 First (Statements (Handled_Statement_Sequence (N))));
1308 Set_First_Real_Statement (Handled_Statement_Sequence (N), Blok);
1311 Append_List_To (Declarations (N),
1312 Statements (Handled_Statement_Sequence (N)));
1313 Set_Statements (Handled_Statement_Sequence (N), Declarations (N));
1315 -- We need to reset the Sloc of the handled statement sequence to
1316 -- properly reflect the new initial "statement" in the sequence.
1319 (Handled_Statement_Sequence (N), Sloc (First (Declarations (N))));
1321 -- The declarations of the _Clean procedure and finalization chain
1322 -- replace the old declarations that have been moved inward
1324 Set_Declarations (N, New_Decls);
1325 Analyze_Declarations (New_Decls);
1327 -- The At_End call is attached to the sequence of statements.
1333 -- If the construct is a protected subprogram, then the call to
1334 -- the corresponding unprotected program appears in a block which
1335 -- is the last statement in the body, and it is this block that
1336 -- must be covered by the At_End handler.
1338 if Is_Protected then
1339 HSS := Handled_Statement_Sequence
1340 (Last (Statements (Handled_Statement_Sequence (N))));
1342 HSS := Handled_Statement_Sequence (N);
1345 Set_At_End_Proc (HSS, New_Occurrence_Of (Clean, Loc));
1346 Expand_At_End_Handler (HSS, Empty);
1349 -- Restore saved polling mode
1351 Polling_Required := Old_Poll;
1352 end Expand_Cleanup_Actions;
1354 -------------------------------
1355 -- Expand_Ctrl_Function_Call --
1356 -------------------------------
1358 procedure Expand_Ctrl_Function_Call (N : Node_Id) is
1359 Loc : constant Source_Ptr := Sloc (N);
1360 Rtype : constant Entity_Id := Etype (N);
1361 Utype : constant Entity_Id := Underlying_Type (Rtype);
1364 Action2 : Node_Id := Empty;
1366 Attach_Level : Uint := Uint_1;
1367 Len_Ref : Node_Id := Empty;
1369 function Last_Array_Component
1373 -- Creates a reference to the last component of the array object
1374 -- designated by Ref whose type is Typ.
1376 --------------------------
1377 -- Last_Array_Component --
1378 --------------------------
1380 function Last_Array_Component
1385 Index_List : constant List_Id := New_List;
1388 for N in 1 .. Number_Dimensions (Typ) loop
1389 Append_To (Index_List,
1390 Make_Attribute_Reference (Loc,
1391 Prefix => Duplicate_Subexpr_No_Checks (Ref),
1392 Attribute_Name => Name_Last,
1393 Expressions => New_List (
1394 Make_Integer_Literal (Loc, N))));
1398 Make_Indexed_Component (Loc,
1399 Prefix => Duplicate_Subexpr (Ref),
1400 Expressions => Index_List);
1401 end Last_Array_Component;
1403 -- Start of processing for Expand_Ctrl_Function_Call
1406 -- Optimization, if the returned value (which is on the sec-stack)
1407 -- is returned again, no need to copy/readjust/finalize, we can just
1408 -- pass the value thru (see Expand_N_Return_Statement), and thus no
1409 -- attachment is needed
1411 if Nkind (Parent (N)) = N_Return_Statement then
1415 -- Resolution is now finished, make sure we don't start analysis again
1416 -- because of the duplication
1419 Ref := Duplicate_Subexpr_No_Checks (N);
1421 -- Now we can generate the Attach Call, note that this value is
1422 -- always in the (secondary) stack and thus is attached to a singly
1423 -- linked final list:
1425 -- Resx := F (X)'reference;
1426 -- Attach_To_Final_List (_Lx, Resx.all, 1);
1428 -- or when there are controlled components
1430 -- Attach_To_Final_List (_Lx, Resx._controller, 1);
1432 -- or when it is both is_controlled and has_controlled_components
1434 -- Attach_To_Final_List (_Lx, Resx._controller, 1);
1435 -- Attach_To_Final_List (_Lx, Resx, 1);
1437 -- or if it is an array with is_controlled (and has_controlled)
1439 -- Attach_To_Final_List (_Lx, Resx (Resx'last), 3);
1440 -- An attach level of 3 means that a whole array is to be
1441 -- attached to the finalization list (including the controlled
1444 -- or if it is an array with has_controlled components but not
1447 -- Attach_To_Final_List (_Lx, Resx (Resx'last)._controller, 3);
1449 if Has_Controlled_Component (Rtype) then
1451 T1 : Entity_Id := Rtype;
1452 T2 : Entity_Id := Utype;
1455 if Is_Array_Type (T2) then
1457 Make_Attribute_Reference (Loc,
1459 Duplicate_Subexpr_Move_Checks
1460 (Unchecked_Convert_To (T2, Ref)),
1461 Attribute_Name => Name_Length);
1464 while Is_Array_Type (T2) loop
1466 Ref := Unchecked_Convert_To (T2, Ref);
1469 Ref := Last_Array_Component (Ref, T2);
1470 Attach_Level := Uint_3;
1471 T1 := Component_Type (T2);
1472 T2 := Underlying_Type (T1);
1475 -- If the type has controlled components, go to the controller
1476 -- except in the case of arrays of controlled objects since in
1477 -- this case objects and their components are already chained
1478 -- and the head of the chain is the last array element.
1480 if Is_Array_Type (Rtype) and then Is_Controlled (T2) then
1483 elsif Has_Controlled_Component (T2) then
1485 Ref := Unchecked_Convert_To (T2, Ref);
1489 Make_Selected_Component (Loc,
1491 Selector_Name => Make_Identifier (Loc, Name_uController));
1495 -- Here we know that 'Ref' has a controller so we may as well
1496 -- attach it directly
1501 Flist_Ref => Find_Final_List (Current_Scope),
1502 With_Attach => Make_Integer_Literal (Loc, Attach_Level));
1504 -- If it is also Is_Controlled we need to attach the global object
1506 if Is_Controlled (Rtype) then
1509 Obj_Ref => Duplicate_Subexpr_No_Checks (N),
1510 Flist_Ref => Find_Final_List (Current_Scope),
1511 With_Attach => Make_Integer_Literal (Loc, Attach_Level));
1515 -- Here, we have a controlled type that does not seem to have
1516 -- controlled components but it could be a class wide type whose
1517 -- further derivations have controlled components. So we don't know
1518 -- if the object itself needs to be attached or if it
1519 -- has a record controller. We need to call a runtime function
1520 -- (Deep_Tag_Attach) which knows what to do thanks to the
1521 -- RC_Offset in the dispatch table.
1524 Make_Procedure_Call_Statement (Loc,
1525 Name => New_Reference_To (RTE (RE_Deep_Tag_Attach), Loc),
1526 Parameter_Associations => New_List (
1527 Find_Final_List (Current_Scope),
1529 Make_Attribute_Reference (Loc,
1531 Attribute_Name => Name_Address),
1533 Make_Integer_Literal (Loc, Attach_Level)));
1536 if Present (Len_Ref) then
1538 Make_Implicit_If_Statement (N,
1539 Condition => Make_Op_Gt (Loc,
1540 Left_Opnd => Len_Ref,
1541 Right_Opnd => Make_Integer_Literal (Loc, 0)),
1542 Then_Statements => New_List (Action));
1545 Insert_Action (N, Action);
1546 if Present (Action2) then
1547 Insert_Action (N, Action2);
1549 end Expand_Ctrl_Function_Call;
1551 ---------------------------
1552 -- Expand_N_Package_Body --
1553 ---------------------------
1555 -- Add call to Activate_Tasks if body is an activator (actual
1556 -- processing is in chapter 9).
1558 -- Generate subprogram descriptor for elaboration routine
1560 -- ENcode entity names in package body
1562 procedure Expand_N_Package_Body (N : Node_Id) is
1563 Ent : constant Entity_Id := Corresponding_Spec (N);
1566 -- This is done only for non-generic packages
1568 if Ekind (Ent) = E_Package then
1569 New_Scope (Corresponding_Spec (N));
1570 Build_Task_Activation_Call (N);
1574 Set_Elaboration_Flag (N, Corresponding_Spec (N));
1576 -- Generate a subprogram descriptor for the elaboration routine of
1577 -- a package body if the package body has no pending instantiations
1578 -- and it has generated at least one exception handler
1580 if Present (Handler_Records (Body_Entity (Ent)))
1581 and then Is_Compilation_Unit (Ent)
1582 and then not Delay_Subprogram_Descriptors (Body_Entity (Ent))
1584 Generate_Subprogram_Descriptor_For_Package
1585 (N, Body_Entity (Ent));
1588 Set_In_Package_Body (Ent, False);
1590 -- Set to encode entity names in package body before gigi is called
1592 Qualify_Entity_Names (N);
1593 end Expand_N_Package_Body;
1595 ----------------------------------
1596 -- Expand_N_Package_Declaration --
1597 ----------------------------------
1599 -- Add call to Activate_Tasks if there are tasks declared and the
1600 -- package has no body. Note that in Ada83, this may result in
1601 -- premature activation of some tasks, given that we cannot tell
1602 -- whether a body will eventually appear.
1604 procedure Expand_N_Package_Declaration (N : Node_Id) is
1606 if Nkind (Parent (N)) = N_Compilation_Unit
1607 and then not Body_Required (Parent (N))
1608 and then not Unit_Requires_Body (Defining_Entity (N))
1609 and then Present (Activation_Chain_Entity (N))
1611 New_Scope (Defining_Entity (N));
1612 Build_Task_Activation_Call (N);
1616 -- Note: it is not necessary to worry about generating a subprogram
1617 -- descriptor, since the only way to get exception handlers into a
1618 -- package spec is to include instantiations, and that would cause
1619 -- generation of subprogram descriptors to be delayed in any case.
1621 -- Set to encode entity names in package spec before gigi is called
1623 Qualify_Entity_Names (N);
1624 end Expand_N_Package_Declaration;
1626 ---------------------
1627 -- Find_Final_List --
1628 ---------------------
1630 function Find_Final_List
1632 Ref : Node_Id := Empty)
1635 Loc : constant Source_Ptr := Sloc (Ref);
1641 -- Case of an internal component. The Final list is the record
1642 -- controller of the enclosing record
1644 if Present (Ref) then
1648 when N_Unchecked_Type_Conversion | N_Type_Conversion =>
1649 R := Expression (R);
1651 when N_Indexed_Component | N_Explicit_Dereference =>
1654 when N_Selected_Component =>
1658 when N_Identifier =>
1662 raise Program_Error;
1667 Make_Selected_Component (Loc,
1669 Make_Selected_Component (Loc,
1671 Selector_Name => Make_Identifier (Loc, Name_uController)),
1672 Selector_Name => Make_Identifier (Loc, Name_F));
1674 -- Case of a dynamically allocated object. The final list is the
1675 -- corresponding list controller (The next entity in the scope of
1676 -- the access type with the right type). If the type comes from a
1677 -- With_Type clause, no controller was created, and we use the
1678 -- global chain instead.
1680 elsif Is_Access_Type (E) then
1681 if not From_With_Type (E) then
1683 Make_Selected_Component (Loc,
1686 (Associated_Final_Chain (Base_Type (E)), Loc),
1687 Selector_Name => Make_Identifier (Loc, Name_F));
1689 return New_Reference_To (RTE (RE_Global_Final_List), Sloc (E));
1693 if Is_Dynamic_Scope (E) then
1696 S := Enclosing_Dynamic_Scope (E);
1699 -- When the finalization chain entity is 'Error', it means that
1700 -- there should not be any chain at that level and that the
1701 -- enclosing one should be used
1703 -- This is a nasty kludge, see ??? note in exp_ch11
1705 while Finalization_Chain_Entity (S) = Error loop
1706 S := Enclosing_Dynamic_Scope (S);
1709 if S = Standard_Standard then
1710 return New_Reference_To (RTE (RE_Global_Final_List), Sloc (E));
1712 if No (Finalization_Chain_Entity (S)) then
1714 Id := Make_Defining_Identifier (Sloc (S),
1715 New_Internal_Name ('F'));
1716 Set_Finalization_Chain_Entity (S, Id);
1718 -- Set momentarily some semantics attributes to allow normal
1719 -- analysis of expansions containing references to this chain.
1720 -- Will be fully decorated during the expansion of the scope
1723 Set_Ekind (Id, E_Variable);
1724 Set_Etype (Id, RTE (RE_Finalizable_Ptr));
1727 return New_Reference_To (Finalization_Chain_Entity (S), Sloc (E));
1730 end Find_Final_List;
1732 -----------------------------
1733 -- Find_Node_To_Be_Wrapped --
1734 -----------------------------
1736 function Find_Node_To_Be_Wrapped (N : Node_Id) return Node_Id is
1738 The_Parent : Node_Id;
1744 pragma Assert (P /= Empty);
1745 The_Parent := Parent (P);
1747 case Nkind (The_Parent) is
1749 -- Simple statement can be wrapped
1754 -- Usually assignments are good candidate for wrapping
1755 -- except when they have been generated as part of a
1756 -- controlled aggregate where the wrapping should take
1757 -- place more globally.
1759 when N_Assignment_Statement =>
1760 if No_Ctrl_Actions (The_Parent) then
1766 -- An entry call statement is a special case if it occurs in
1767 -- the context of a Timed_Entry_Call. In this case we wrap
1768 -- the entire timed entry call.
1770 when N_Entry_Call_Statement |
1771 N_Procedure_Call_Statement =>
1772 if Nkind (Parent (The_Parent)) = N_Entry_Call_Alternative
1774 Nkind (Parent (Parent (The_Parent))) = N_Timed_Entry_Call
1776 return Parent (Parent (The_Parent));
1781 -- Object declarations are also a boundary for the transient scope
1782 -- even if they are not really wrapped
1783 -- (see Wrap_Transient_Declaration)
1785 when N_Object_Declaration |
1786 N_Object_Renaming_Declaration |
1787 N_Subtype_Declaration =>
1790 -- The expression itself is to be wrapped if its parent is a
1791 -- compound statement or any other statement where the expression
1792 -- is known to be scalar
1794 when N_Accept_Alternative |
1795 N_Attribute_Definition_Clause |
1798 N_Delay_Alternative |
1799 N_Delay_Until_Statement |
1800 N_Delay_Relative_Statement |
1801 N_Discriminant_Association |
1803 N_Entry_Body_Formal_Part |
1806 N_Iteration_Scheme |
1807 N_Terminate_Alternative =>
1810 when N_Attribute_Reference =>
1812 if Is_Procedure_Attribute_Name
1813 (Attribute_Name (The_Parent))
1818 -- ??? No scheme yet for "for I in Expression'Range loop"
1819 -- ??? the current scheme for Expression wrapping doesn't apply
1820 -- ??? because a RANGE is NOT an expression. Tricky problem...
1821 -- ??? while this problem is not solved we have a potential for
1822 -- ??? leak and unfinalized intermediate objects here.
1824 when N_Loop_Parameter_Specification =>
1827 -- The following nodes contains "dummy calls" which don't
1828 -- need to be wrapped.
1830 when N_Parameter_Specification |
1831 N_Discriminant_Specification |
1832 N_Component_Declaration =>
1835 -- The return statement is not to be wrapped when the function
1836 -- itself needs wrapping at the outer-level
1838 when N_Return_Statement =>
1839 if Requires_Transient_Scope (Return_Type (The_Parent)) then
1845 -- If we leave a scope without having been able to find a node to
1846 -- wrap, something is going wrong but this can happen in error
1847 -- situation that are not detected yet (such as a dynamic string
1848 -- in a pragma export)
1850 when N_Subprogram_Body |
1851 N_Package_Declaration |
1853 N_Block_Statement =>
1856 -- otherwise continue the search
1862 end Find_Node_To_Be_Wrapped;
1864 ----------------------
1865 -- Global_Flist_Ref --
1866 ----------------------
1868 function Global_Flist_Ref (Flist_Ref : Node_Id) return Boolean is
1872 -- Look for the Global_Final_List
1874 if Is_Entity_Name (Flist_Ref) then
1875 Flist := Entity (Flist_Ref);
1877 -- Look for the final list associated with an access to controlled
1879 elsif Nkind (Flist_Ref) = N_Selected_Component
1880 and then Is_Entity_Name (Prefix (Flist_Ref))
1882 Flist := Entity (Prefix (Flist_Ref));
1887 return Present (Flist)
1888 and then Present (Scope (Flist))
1889 and then Enclosing_Dynamic_Scope (Flist) = Standard_Standard;
1890 end Global_Flist_Ref;
1892 ----------------------------------
1893 -- Has_New_Controlled_Component --
1894 ----------------------------------
1896 function Has_New_Controlled_Component (E : Entity_Id) return Boolean is
1900 if not Is_Tagged_Type (E) then
1901 return Has_Controlled_Component (E);
1902 elsif not Is_Derived_Type (E) then
1903 return Has_Controlled_Component (E);
1906 Comp := First_Component (E);
1907 while Present (Comp) loop
1909 if Chars (Comp) = Name_uParent then
1912 elsif Scope (Original_Record_Component (Comp)) = E
1913 and then Controlled_Type (Etype (Comp))
1918 Next_Component (Comp);
1922 end Has_New_Controlled_Component;
1924 --------------------------
1925 -- In_Finalization_Root --
1926 --------------------------
1928 -- It would seem simpler to test Scope (RTE (RE_Root_Controlled)) but
1929 -- the purpose of this function is to avoid a circular call to Rtsfind
1930 -- which would been caused by such a test.
1932 function In_Finalization_Root (E : Entity_Id) return Boolean is
1933 S : constant Entity_Id := Scope (E);
1936 return Chars (Scope (S)) = Name_System
1937 and then Chars (S) = Name_Finalization_Root
1938 and then Scope (Scope (S)) = Standard_Standard;
1939 end In_Finalization_Root;
1941 ------------------------------------
1942 -- Insert_Actions_In_Scope_Around --
1943 ------------------------------------
1945 procedure Insert_Actions_In_Scope_Around (N : Node_Id) is
1946 SE : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
1949 if Present (SE.Actions_To_Be_Wrapped_Before) then
1950 Insert_List_Before (N, SE.Actions_To_Be_Wrapped_Before);
1951 SE.Actions_To_Be_Wrapped_Before := No_List;
1954 if Present (SE.Actions_To_Be_Wrapped_After) then
1955 Insert_List_After (N, SE.Actions_To_Be_Wrapped_After);
1956 SE.Actions_To_Be_Wrapped_After := No_List;
1958 end Insert_Actions_In_Scope_Around;
1960 -----------------------
1961 -- Make_Adjust_Call --
1962 -----------------------
1964 function Make_Adjust_Call
1967 Flist_Ref : Node_Id;
1968 With_Attach : Node_Id)
1971 Loc : constant Source_Ptr := Sloc (Ref);
1972 Res : constant List_Id := New_List;
1975 Cref : Node_Id := Ref;
1977 Attach : Node_Id := With_Attach;
1980 if Is_Class_Wide_Type (Typ) then
1981 Utyp := Underlying_Type (Base_Type (Root_Type (Typ)));
1983 Utyp := Underlying_Type (Base_Type (Typ));
1986 Set_Assignment_OK (Cref);
1988 -- Deal with non-tagged derivation of private views
1990 if Is_Untagged_Derivation (Typ) then
1991 Utyp := Underlying_Type (Root_Type (Base_Type (Typ)));
1992 Cref := Unchecked_Convert_To (Utyp, Cref);
1993 Set_Assignment_OK (Cref);
1994 -- To prevent problems with UC see 1.156 RH ???
1997 -- If the underlying_type is a subtype, we are dealing with
1998 -- the completion of a private type. We need to access
1999 -- the base type and generate a conversion to it.
2001 if Utyp /= Base_Type (Utyp) then
2002 pragma Assert (Is_Private_Type (Typ));
2003 Utyp := Base_Type (Utyp);
2004 Cref := Unchecked_Convert_To (Utyp, Cref);
2007 -- If the object is unanalyzed, set its expected type for use
2008 -- in Convert_View in case an additional conversion is needed.
2010 if No (Etype (Cref))
2011 and then Nkind (Cref) /= N_Unchecked_Type_Conversion
2013 Set_Etype (Cref, Typ);
2016 -- We do not need to attach to one of the Global Final Lists
2017 -- the objects whose type is Finalize_Storage_Only
2019 if Finalize_Storage_Only (Typ)
2020 and then (Global_Flist_Ref (Flist_Ref)
2021 or else Entity (Constant_Value (RTE (RE_Garbage_Collected)))
2024 Attach := Make_Integer_Literal (Loc, 0);
2028 -- Deep_Adjust (Flist_Ref, Ref, With_Attach);
2030 if Has_Controlled_Component (Utyp)
2031 or else Is_Class_Wide_Type (Typ)
2033 if Is_Tagged_Type (Utyp) then
2034 Proc := Find_Prim_Op (Utyp, TSS_Deep_Adjust);
2037 Proc := TSS (Utyp, TSS_Deep_Adjust);
2040 Cref := Convert_View (Proc, Cref, 2);
2043 Make_Procedure_Call_Statement (Loc,
2044 Name => New_Reference_To (Proc, Loc),
2045 Parameter_Associations =>
2046 New_List (Flist_Ref, Cref, Attach)));
2049 -- if With_Attach then
2050 -- Attach_To_Final_List (Ref, Flist_Ref);
2054 else -- Is_Controlled (Utyp)
2056 Proc := Find_Prim_Op (Utyp, Name_Of (Adjust_Case));
2057 Cref := Convert_View (Proc, Cref);
2058 Cref2 := New_Copy_Tree (Cref);
2061 Make_Procedure_Call_Statement (Loc,
2062 Name => New_Reference_To (Proc, Loc),
2063 Parameter_Associations => New_List (Cref2)));
2065 Append_To (Res, Make_Attach_Call (Cref, Flist_Ref, Attach));
2069 end Make_Adjust_Call;
2071 ----------------------
2072 -- Make_Attach_Call --
2073 ----------------------
2076 -- System.FI.Attach_To_Final_List (Flist, Ref, Nb_Link)
2078 function Make_Attach_Call
2080 Flist_Ref : Node_Id;
2081 With_Attach : Node_Id)
2084 Loc : constant Source_Ptr := Sloc (Obj_Ref);
2087 -- Optimization: If the number of links is statically '0', don't
2088 -- call the attach_proc.
2090 if Nkind (With_Attach) = N_Integer_Literal
2091 and then Intval (With_Attach) = Uint_0
2093 return Make_Null_Statement (Loc);
2097 Make_Procedure_Call_Statement (Loc,
2098 Name => New_Reference_To (RTE (RE_Attach_To_Final_List), Loc),
2099 Parameter_Associations => New_List (
2101 OK_Convert_To (RTE (RE_Finalizable), Obj_Ref),
2103 end Make_Attach_Call;
2115 Is_Master : Boolean;
2116 Is_Protected_Subprogram : Boolean;
2117 Is_Task_Allocation_Block : Boolean;
2118 Is_Asynchronous_Call_Block : Boolean)
2121 Loc : constant Source_Ptr := Sloc (Clean);
2122 Stmt : constant List_Id := New_List;
2129 Param_Type : Entity_Id;
2130 Pid : Entity_Id := Empty;
2131 Cancel_Param : Entity_Id;
2135 if Restricted_Profile then
2137 (Stmt, Build_Runtime_Call (Loc, RE_Complete_Restricted_Task));
2139 Append_To (Stmt, Build_Runtime_Call (Loc, RE_Complete_Task));
2142 elsif Is_Master then
2143 if Restrictions (No_Task_Hierarchy) = False then
2144 Append_To (Stmt, Build_Runtime_Call (Loc, RE_Complete_Master));
2147 elsif Is_Protected_Subprogram then
2149 -- Add statements to the cleanup handler of the (ordinary)
2150 -- subprogram expanded to implement a protected subprogram,
2151 -- unlocking the protected object parameter and undeferring abortion.
2152 -- If this is a protected procedure, and the object contains
2153 -- entries, this also calls the entry service routine.
2155 -- NOTE: This cleanup handler references _object, a parameter
2156 -- to the procedure.
2158 -- Find the _object parameter representing the protected object.
2160 Spec := Parent (Corresponding_Spec (N));
2162 Param := First (Parameter_Specifications (Spec));
2164 Param_Type := Etype (Parameter_Type (Param));
2166 if Ekind (Param_Type) = E_Record_Type then
2167 Pid := Corresponding_Concurrent_Type (Param_Type);
2170 exit when not Present (Param) or else Present (Pid);
2174 pragma Assert (Present (Param));
2176 -- If the associated protected object declares entries,
2177 -- a protected procedure has to service entry queues.
2178 -- In this case, add
2180 -- Service_Entries (_object._object'Access);
2182 -- _object is the record used to implement the protected object.
2183 -- It is a parameter to the protected subprogram.
2185 if Nkind (Specification (N)) = N_Procedure_Specification
2186 and then Has_Entries (Pid)
2189 or else Restrictions (No_Entry_Queue) = False
2190 or else Number_Entries (Pid) > 1
2192 Name := New_Reference_To (RTE (RE_Service_Entries), Loc);
2194 Name := New_Reference_To (RTE (RE_Service_Entry), Loc);
2198 Make_Procedure_Call_Statement (Loc,
2200 Parameter_Associations => New_List (
2201 Make_Attribute_Reference (Loc,
2203 Make_Selected_Component (Loc,
2204 Prefix => New_Reference_To (
2205 Defining_Identifier (Param), Loc),
2207 Make_Identifier (Loc, Name_uObject)),
2208 Attribute_Name => Name_Unchecked_Access))));
2211 -- Unlock (_object._object'Access);
2213 -- _object is the record used to implement the protected object.
2214 -- It is a parameter to the protected subprogram.
2216 -- If the protected object is controlled (i.e it has entries or
2217 -- needs finalization for interrupt handling), call Unlock_Entries,
2218 -- except if the protected object follows the ravenscar profile, in
2219 -- which case call Unlock_Entry, otherwise call the simplified
2222 if Has_Entries (Pid)
2223 or else Has_Interrupt_Handler (Pid)
2224 or else (Has_Attach_Handler (Pid) and then not Restricted_Profile)
2227 or else Restrictions (No_Entry_Queue) = False
2228 or else Number_Entries (Pid) > 1
2230 Unlock := New_Reference_To (RTE (RE_Unlock_Entries), Loc);
2232 Unlock := New_Reference_To (RTE (RE_Unlock_Entry), Loc);
2236 Unlock := New_Reference_To (RTE (RE_Unlock), Loc);
2240 Make_Procedure_Call_Statement (Loc,
2242 Parameter_Associations => New_List (
2243 Make_Attribute_Reference (Loc,
2245 Make_Selected_Component (Loc,
2247 New_Reference_To (Defining_Identifier (Param), Loc),
2249 Make_Identifier (Loc, Name_uObject)),
2250 Attribute_Name => Name_Unchecked_Access))));
2252 if Abort_Allowed then
2256 Make_Procedure_Call_Statement (Loc,
2259 RTE (RE_Abort_Undefer), Loc),
2260 Parameter_Associations => Empty_List));
2263 elsif Is_Task_Allocation_Block then
2265 -- Add a call to Expunge_Unactivated_Tasks to the cleanup
2266 -- handler of a block created for the dynamic allocation of
2269 -- Expunge_Unactivated_Tasks (_chain);
2271 -- where _chain is the list of tasks created by the allocator
2272 -- but not yet activated. This list will be empty unless
2273 -- the block completes abnormally.
2275 -- This only applies to dynamically allocated tasks;
2276 -- other unactivated tasks are completed by Complete_Task or
2279 -- NOTE: This cleanup handler references _chain, a local
2283 Make_Procedure_Call_Statement (Loc,
2286 RTE (RE_Expunge_Unactivated_Tasks), Loc),
2287 Parameter_Associations => New_List (
2288 New_Reference_To (Activation_Chain_Entity (N), Loc))));
2290 elsif Is_Asynchronous_Call_Block then
2292 -- Add a call to attempt to cancel the asynchronous entry call
2293 -- whenever the block containing the abortable part is exited.
2295 -- NOTE: This cleanup handler references C, a local object
2297 -- Get the argument to the Cancel procedure
2298 Cancel_Param := Entry_Cancel_Parameter (Entity (Identifier (N)));
2300 -- If it is of type Communication_Block, this must be a
2301 -- protected entry call.
2303 if Is_RTE (Etype (Cancel_Param), RE_Communication_Block) then
2307 -- if Enqueued (Cancel_Parameter) then
2309 Make_Implicit_If_Statement (Clean,
2310 Condition => Make_Function_Call (Loc,
2311 Name => New_Reference_To (
2312 RTE (RE_Enqueued), Loc),
2313 Parameter_Associations => New_List (
2314 New_Reference_To (Cancel_Param, Loc))),
2315 Then_Statements => New_List (
2317 -- Cancel_Protected_Entry_Call (Cancel_Param);
2319 Make_Procedure_Call_Statement (Loc,
2320 Name => New_Reference_To (
2321 RTE (RE_Cancel_Protected_Entry_Call), Loc),
2322 Parameter_Associations => New_List (
2323 New_Reference_To (Cancel_Param, Loc))))));
2325 -- Asynchronous delay
2327 elsif Is_RTE (Etype (Cancel_Param), RE_Delay_Block) then
2329 Make_Procedure_Call_Statement (Loc,
2330 Name => New_Reference_To (RTE (RE_Cancel_Async_Delay), Loc),
2331 Parameter_Associations => New_List (
2332 Make_Attribute_Reference (Loc,
2333 Prefix => New_Reference_To (Cancel_Param, Loc),
2334 Attribute_Name => Name_Unchecked_Access))));
2339 -- Append call to Cancel_Task_Entry_Call (C);
2342 Make_Procedure_Call_Statement (Loc,
2343 Name => New_Reference_To (
2344 RTE (RE_Cancel_Task_Entry_Call),
2346 Parameter_Associations => New_List (
2347 New_Reference_To (Cancel_Param, Loc))));
2352 if Present (Flist) then
2354 Make_Procedure_Call_Statement (Loc,
2355 Name => New_Reference_To (RTE (RE_Finalize_List), Loc),
2356 Parameter_Associations => New_List (
2357 New_Reference_To (Flist, Loc))));
2360 if Present (Mark) then
2362 Make_Procedure_Call_Statement (Loc,
2363 Name => New_Reference_To (RTE (RE_SS_Release), Loc),
2364 Parameter_Associations => New_List (
2365 New_Reference_To (Mark, Loc))));
2369 Make_Subprogram_Body (Loc,
2371 Make_Procedure_Specification (Loc,
2372 Defining_Unit_Name => Clean),
2374 Declarations => New_List,
2376 Handled_Statement_Sequence =>
2377 Make_Handled_Sequence_Of_Statements (Loc,
2378 Statements => Stmt));
2380 if Present (Flist) or else Is_Task or else Is_Master then
2381 Wrap_Cleanup_Procedure (Sbody);
2384 -- We do not want debug information for _Clean routines,
2385 -- since it just confuses the debugging operation unless
2386 -- we are debugging generated code.
2388 if not Debug_Generated_Code then
2389 Set_Debug_Info_Off (Clean, True);
2395 --------------------------
2396 -- Make_Deep_Array_Body --
2397 --------------------------
2399 -- Array components are initialized and adjusted in the normal order
2400 -- and finalized in the reverse order. Exceptions are handled and
2401 -- Program_Error is re-raise in the Adjust and Finalize case
2402 -- (RM 7.6.1(12)). Generate the following code :
2404 -- procedure Deep_<P> -- with <P> being Initialize or Adjust or Finalize
2405 -- (L : in out Finalizable_Ptr;
2409 -- for J1 in Typ'First (1) .. Typ'Last (1) loop
2410 -- ^ reverse ^ -- in the finalization case
2412 -- for J2 in Typ'First (n) .. Typ'Last (n) loop
2413 -- Make_<P>_Call (Typ, V (J1, .. , Jn), L, V);
2417 -- exception -- not in the
2418 -- when others => raise Program_Error; -- Initialize case
2421 function Make_Deep_Array_Body
2422 (Prim : Final_Primitives;
2426 Loc : constant Source_Ptr := Sloc (Typ);
2428 Index_List : constant List_Id := New_List;
2429 -- Stores the list of references to the indexes (one per dimension)
2431 function One_Component return List_Id;
2432 -- Create one statement to initialize/adjust/finalize one array
2433 -- component, designated by a full set of indices.
2435 function One_Dimension (N : Int) return List_Id;
2436 -- Create loop to deal with one dimension of the array. The single
2437 -- statement in the body of the loop initializes the inner dimensions if
2438 -- any, or else a single component.
2444 function One_Component return List_Id is
2445 Comp_Typ : constant Entity_Id := Component_Type (Typ);
2446 Comp_Ref : constant Node_Id :=
2447 Make_Indexed_Component (Loc,
2448 Prefix => Make_Identifier (Loc, Name_V),
2449 Expressions => Index_List);
2452 -- Set the etype of the component Reference, which is used to
2453 -- determine whether a conversion to a parent type is needed.
2455 Set_Etype (Comp_Ref, Comp_Typ);
2458 when Initialize_Case =>
2459 return Make_Init_Call (Comp_Ref, Comp_Typ,
2460 Make_Identifier (Loc, Name_L),
2461 Make_Identifier (Loc, Name_B));
2464 return Make_Adjust_Call (Comp_Ref, Comp_Typ,
2465 Make_Identifier (Loc, Name_L),
2466 Make_Identifier (Loc, Name_B));
2468 when Finalize_Case =>
2469 return Make_Final_Call (Comp_Ref, Comp_Typ,
2470 Make_Identifier (Loc, Name_B));
2478 function One_Dimension (N : Int) return List_Id is
2482 if N > Number_Dimensions (Typ) then
2483 return One_Component;
2487 Make_Defining_Identifier (Loc, New_External_Name ('J', N));
2489 Append_To (Index_List, New_Reference_To (Index, Loc));
2492 Make_Implicit_Loop_Statement (Typ,
2493 Identifier => Empty,
2495 Make_Iteration_Scheme (Loc,
2496 Loop_Parameter_Specification =>
2497 Make_Loop_Parameter_Specification (Loc,
2498 Defining_Identifier => Index,
2499 Discrete_Subtype_Definition =>
2500 Make_Attribute_Reference (Loc,
2501 Prefix => Make_Identifier (Loc, Name_V),
2502 Attribute_Name => Name_Range,
2503 Expressions => New_List (
2504 Make_Integer_Literal (Loc, N))),
2505 Reverse_Present => Prim = Finalize_Case)),
2506 Statements => One_Dimension (N + 1)));
2510 -- Start of processing for Make_Deep_Array_Body
2513 return One_Dimension (1);
2514 end Make_Deep_Array_Body;
2516 --------------------
2517 -- Make_Deep_Proc --
2518 --------------------
2521 -- procedure DEEP_<prim>
2522 -- (L : IN OUT Finalizable_Ptr; -- not for Finalize
2523 -- V : IN OUT <typ>;
2524 -- B : IN Short_Short_Integer) is
2527 -- exception -- Finalize and Adjust Cases only
2528 -- raise Program_Error; -- idem
2531 function Make_Deep_Proc
2532 (Prim : Final_Primitives;
2537 Loc : constant Source_Ptr := Sloc (Typ);
2539 Proc_Name : Entity_Id;
2540 Handler : List_Id := No_List;
2544 if Prim = Finalize_Case then
2545 Formals := New_List;
2546 Type_B := Standard_Boolean;
2549 Formals := New_List (
2550 Make_Parameter_Specification (Loc,
2551 Defining_Identifier => Make_Defining_Identifier (Loc, Name_L),
2553 Out_Present => True,
2555 New_Reference_To (RTE (RE_Finalizable_Ptr), Loc)));
2556 Type_B := Standard_Short_Short_Integer;
2560 Make_Parameter_Specification (Loc,
2561 Defining_Identifier => Make_Defining_Identifier (Loc, Name_V),
2563 Out_Present => True,
2564 Parameter_Type => New_Reference_To (Typ, Loc)));
2567 Make_Parameter_Specification (Loc,
2568 Defining_Identifier => Make_Defining_Identifier (Loc, Name_B),
2569 Parameter_Type => New_Reference_To (Type_B, Loc)));
2571 if Prim = Finalize_Case or else Prim = Adjust_Case then
2572 Handler := New_List (
2573 Make_Exception_Handler (Loc,
2574 Exception_Choices => New_List (Make_Others_Choice (Loc)),
2575 Statements => New_List (
2576 Make_Raise_Program_Error (Loc,
2577 Reason => PE_Finalize_Raised_Exception))));
2581 Make_Defining_Identifier (Loc,
2582 Chars => Make_TSS_Name (Typ, Deep_Name_Of (Prim)));
2585 Make_Subprogram_Body (Loc,
2587 Make_Procedure_Specification (Loc,
2588 Defining_Unit_Name => Proc_Name,
2589 Parameter_Specifications => Formals),
2591 Declarations => Empty_List,
2592 Handled_Statement_Sequence =>
2593 Make_Handled_Sequence_Of_Statements (Loc,
2594 Statements => Stmts,
2595 Exception_Handlers => Handler)));
2600 ---------------------------
2601 -- Make_Deep_Record_Body --
2602 ---------------------------
2604 -- The Deep procedures call the appropriate Controlling proc on the
2605 -- the controller component. In the init case, it also attach the
2606 -- controller to the current finalization list.
2608 function Make_Deep_Record_Body
2609 (Prim : Final_Primitives;
2613 Loc : constant Source_Ptr := Sloc (Typ);
2614 Controller_Typ : Entity_Id;
2615 Obj_Ref : constant Node_Id := Make_Identifier (Loc, Name_V);
2616 Controller_Ref : constant Node_Id :=
2617 Make_Selected_Component (Loc,
2620 Make_Identifier (Loc, Name_uController));
2621 Res : constant List_Id := New_List;
2624 if Is_Return_By_Reference_Type (Typ) then
2625 Controller_Typ := RTE (RE_Limited_Record_Controller);
2627 Controller_Typ := RTE (RE_Record_Controller);
2631 when Initialize_Case =>
2632 Append_List_To (Res,
2634 Ref => Controller_Ref,
2635 Typ => Controller_Typ,
2636 Flist_Ref => Make_Identifier (Loc, Name_L),
2637 With_Attach => Make_Identifier (Loc, Name_B)));
2639 -- When the type is also a controlled type by itself,
2640 -- Initialize it and attach it to the finalization chain
2642 if Is_Controlled (Typ) then
2644 Make_Procedure_Call_Statement (Loc,
2645 Name => New_Reference_To (
2646 Find_Prim_Op (Typ, Name_Of (Prim)), Loc),
2647 Parameter_Associations =>
2648 New_List (New_Copy_Tree (Obj_Ref))));
2650 Append_To (Res, Make_Attach_Call (
2651 Obj_Ref => New_Copy_Tree (Obj_Ref),
2652 Flist_Ref => Make_Identifier (Loc, Name_L),
2653 With_Attach => Make_Identifier (Loc, Name_B)));
2657 Append_List_To (Res,
2658 Make_Adjust_Call (Controller_Ref, Controller_Typ,
2659 Make_Identifier (Loc, Name_L),
2660 Make_Identifier (Loc, Name_B)));
2662 -- When the type is also a controlled type by itself,
2663 -- Adjust it it and attach it to the finalization chain
2665 if Is_Controlled (Typ) then
2667 Make_Procedure_Call_Statement (Loc,
2668 Name => New_Reference_To (
2669 Find_Prim_Op (Typ, Name_Of (Prim)), Loc),
2670 Parameter_Associations =>
2671 New_List (New_Copy_Tree (Obj_Ref))));
2673 Append_To (Res, Make_Attach_Call (
2674 Obj_Ref => New_Copy_Tree (Obj_Ref),
2675 Flist_Ref => Make_Identifier (Loc, Name_L),
2676 With_Attach => Make_Identifier (Loc, Name_B)));
2679 when Finalize_Case =>
2680 if Is_Controlled (Typ) then
2682 Make_Implicit_If_Statement (Obj_Ref,
2683 Condition => Make_Identifier (Loc, Name_B),
2684 Then_Statements => New_List (
2685 Make_Procedure_Call_Statement (Loc,
2686 Name => New_Reference_To (RTE (RE_Finalize_One), Loc),
2687 Parameter_Associations => New_List (
2688 OK_Convert_To (RTE (RE_Finalizable),
2689 New_Copy_Tree (Obj_Ref))))),
2691 Else_Statements => New_List (
2692 Make_Procedure_Call_Statement (Loc,
2693 Name => New_Reference_To (
2694 Find_Prim_Op (Typ, Name_Of (Prim)), Loc),
2695 Parameter_Associations =>
2696 New_List (New_Copy_Tree (Obj_Ref))))));
2699 Append_List_To (Res,
2700 Make_Final_Call (Controller_Ref, Controller_Typ,
2701 Make_Identifier (Loc, Name_B)));
2704 end Make_Deep_Record_Body;
2706 ----------------------
2707 -- Make_Final_Call --
2708 ----------------------
2710 function Make_Final_Call
2713 With_Detach : Node_Id)
2716 Loc : constant Source_Ptr := Sloc (Ref);
2717 Res : constant List_Id := New_List;
2724 if Is_Class_Wide_Type (Typ) then
2725 Utyp := Root_Type (Typ);
2728 elsif Is_Concurrent_Type (Typ) then
2729 Utyp := Corresponding_Record_Type (Typ);
2730 Cref := Convert_Concurrent (Ref, Typ);
2732 elsif Is_Private_Type (Typ)
2733 and then Present (Full_View (Typ))
2734 and then Is_Concurrent_Type (Full_View (Typ))
2736 Utyp := Corresponding_Record_Type (Full_View (Typ));
2737 Cref := Convert_Concurrent (Ref, Full_View (Typ));
2743 Utyp := Underlying_Type (Base_Type (Utyp));
2744 Set_Assignment_OK (Cref);
2746 -- Deal with non-tagged derivation of private views
2748 if Is_Untagged_Derivation (Typ) then
2749 Utyp := Underlying_Type (Root_Type (Base_Type (Typ)));
2750 Cref := Unchecked_Convert_To (Utyp, Cref);
2751 Set_Assignment_OK (Cref);
2752 -- To prevent problems with UC see 1.156 RH ???
2755 -- If the underlying_type is a subtype, we are dealing with
2756 -- the completion of a private type. We need to access
2757 -- the base type and generate a conversion to it.
2759 if Utyp /= Base_Type (Utyp) then
2760 pragma Assert (Is_Private_Type (Typ));
2761 Utyp := Base_Type (Utyp);
2762 Cref := Unchecked_Convert_To (Utyp, Cref);
2766 -- Deep_Finalize (Ref, With_Detach);
2768 if Has_Controlled_Component (Utyp)
2769 or else Is_Class_Wide_Type (Typ)
2771 if Is_Tagged_Type (Utyp) then
2772 Proc := Find_Prim_Op (Utyp, TSS_Deep_Finalize);
2774 Proc := TSS (Utyp, TSS_Deep_Finalize);
2777 Cref := Convert_View (Proc, Cref);
2780 Make_Procedure_Call_Statement (Loc,
2781 Name => New_Reference_To (Proc, Loc),
2782 Parameter_Associations =>
2783 New_List (Cref, With_Detach)));
2786 -- if With_Detach then
2787 -- Finalize_One (Ref);
2793 Proc := Find_Prim_Op (Utyp, Name_Of (Finalize_Case));
2795 if Chars (With_Detach) = Chars (Standard_True) then
2797 Make_Procedure_Call_Statement (Loc,
2798 Name => New_Reference_To (RTE (RE_Finalize_One), Loc),
2799 Parameter_Associations => New_List (
2800 OK_Convert_To (RTE (RE_Finalizable), Cref))));
2802 elsif Chars (With_Detach) = Chars (Standard_False) then
2804 Make_Procedure_Call_Statement (Loc,
2805 Name => New_Reference_To (Proc, Loc),
2806 Parameter_Associations =>
2807 New_List (Convert_View (Proc, Cref))));
2810 Cref2 := New_Copy_Tree (Cref);
2812 Make_Implicit_If_Statement (Ref,
2813 Condition => With_Detach,
2814 Then_Statements => New_List (
2815 Make_Procedure_Call_Statement (Loc,
2816 Name => New_Reference_To (RTE (RE_Finalize_One), Loc),
2817 Parameter_Associations => New_List (
2818 OK_Convert_To (RTE (RE_Finalizable), Cref)))),
2820 Else_Statements => New_List (
2821 Make_Procedure_Call_Statement (Loc,
2822 Name => New_Reference_To (Proc, Loc),
2823 Parameter_Associations =>
2824 New_List (Convert_View (Proc, Cref2))))));
2829 end Make_Final_Call;
2831 --------------------
2832 -- Make_Init_Call --
2833 --------------------
2835 function Make_Init_Call
2838 Flist_Ref : Node_Id;
2839 With_Attach : Node_Id)
2842 Loc : constant Source_Ptr := Sloc (Ref);
2844 Res : constant List_Id := New_List;
2849 Attach : Node_Id := With_Attach;
2852 if Is_Concurrent_Type (Typ) then
2854 Utyp := Corresponding_Record_Type (Typ);
2855 Cref := Convert_Concurrent (Ref, Typ);
2857 elsif Is_Private_Type (Typ)
2858 and then Present (Full_View (Typ))
2859 and then Is_Concurrent_Type (Underlying_Type (Typ))
2862 Utyp := Corresponding_Record_Type (Underlying_Type (Typ));
2863 Cref := Convert_Concurrent (Ref, Underlying_Type (Typ));
2871 Utyp := Underlying_Type (Base_Type (Utyp));
2873 Set_Assignment_OK (Cref);
2875 -- Deal with non-tagged derivation of private views
2877 if Is_Untagged_Derivation (Typ)
2878 and then not Is_Conc
2880 Utyp := Underlying_Type (Root_Type (Base_Type (Typ)));
2881 Cref := Unchecked_Convert_To (Utyp, Cref);
2882 Set_Assignment_OK (Cref);
2883 -- To prevent problems with UC see 1.156 RH ???
2886 -- If the underlying_type is a subtype, we are dealing with
2887 -- the completion of a private type. We need to access
2888 -- the base type and generate a conversion to it.
2890 if Utyp /= Base_Type (Utyp) then
2891 pragma Assert (Is_Private_Type (Typ));
2892 Utyp := Base_Type (Utyp);
2893 Cref := Unchecked_Convert_To (Utyp, Cref);
2896 -- We do not need to attach to one of the Global Final Lists
2897 -- the objects whose type is Finalize_Storage_Only
2899 if Finalize_Storage_Only (Typ)
2900 and then (Global_Flist_Ref (Flist_Ref)
2901 or else Entity (Constant_Value (RTE (RE_Garbage_Collected)))
2904 Attach := Make_Integer_Literal (Loc, 0);
2908 -- Deep_Initialize (Ref, Flist_Ref);
2910 if Has_Controlled_Component (Utyp) then
2911 Proc := TSS (Utyp, Deep_Name_Of (Initialize_Case));
2913 Cref := Convert_View (Proc, Cref, 2);
2916 Make_Procedure_Call_Statement (Loc,
2917 Name => New_Reference_To (Proc, Loc),
2918 Parameter_Associations => New_List (
2924 -- Attach_To_Final_List (Ref, Flist_Ref);
2925 -- Initialize (Ref);
2927 else -- Is_Controlled (Utyp)
2928 Proc := Find_Prim_Op (Utyp, Name_Of (Initialize_Case));
2929 Check_Visibly_Controlled (Initialize_Case, Typ, Proc, Cref);
2931 Cref := Convert_View (Proc, Cref);
2932 Cref2 := New_Copy_Tree (Cref);
2935 Make_Procedure_Call_Statement (Loc,
2936 Name => New_Reference_To (Proc, Loc),
2937 Parameter_Associations => New_List (Cref2)));
2940 Make_Attach_Call (Cref, Flist_Ref, Attach));
2946 --------------------------
2947 -- Make_Transient_Block --
2948 --------------------------
2950 -- If finalization is involved, this function just wraps the instruction
2951 -- into a block whose name is the transient block entity, and then
2952 -- Expand_Cleanup_Actions (called on the expansion of the handled
2953 -- sequence of statements will do the necessary expansions for
2956 function Make_Transient_Block
2961 Flist : constant Entity_Id := Finalization_Chain_Entity (Current_Scope);
2962 Decls : constant List_Id := New_List;
2963 Par : constant Node_Id := Parent (Action);
2964 Instrs : constant List_Id := New_List (Action);
2968 -- Case where only secondary stack use is involved
2970 if Uses_Sec_Stack (Current_Scope)
2972 and then Nkind (Action) /= N_Return_Statement
2973 and then Nkind (Par) /= N_Exception_Handler
2980 S := Scope (Current_Scope);
2984 -- At the outer level, no need to release the sec stack
2986 if S = Standard_Standard then
2987 Set_Uses_Sec_Stack (Current_Scope, False);
2990 -- In a function, only release the sec stack if the
2991 -- function does not return on the sec stack otherwise
2992 -- the result may be lost. The caller is responsible for
2995 elsif K = E_Function then
2996 Set_Uses_Sec_Stack (Current_Scope, False);
2998 if not Requires_Transient_Scope (Etype (S)) then
2999 if not Functions_Return_By_DSP_On_Target then
3000 Set_Uses_Sec_Stack (S, True);
3001 Check_Restriction (No_Secondary_Stack, Action);
3007 -- In a loop or entry we should install a block encompassing
3008 -- all the construct. For now just release right away.
3010 elsif K = E_Loop or else K = E_Entry then
3013 -- In a procedure or a block, we release on exit of the
3014 -- procedure or block. ??? memory leak can be created by
3017 elsif K = E_Procedure
3020 if not Functions_Return_By_DSP_On_Target then
3021 Set_Uses_Sec_Stack (S, True);
3022 Check_Restriction (No_Secondary_Stack, Action);
3025 Set_Uses_Sec_Stack (Current_Scope, False);
3035 -- Insert actions stuck in the transient scopes as well as all
3036 -- freezing nodes needed by those actions
3038 Insert_Actions_In_Scope_Around (Action);
3041 Last_Inserted : Node_Id := Prev (Action);
3044 if Present (Last_Inserted) then
3045 Freeze_All (First_Entity (Current_Scope), Last_Inserted);
3050 Make_Block_Statement (Loc,
3051 Identifier => New_Reference_To (Current_Scope, Loc),
3052 Declarations => Decls,
3053 Handled_Statement_Sequence =>
3054 Make_Handled_Sequence_Of_Statements (Loc, Statements => Instrs),
3055 Has_Created_Identifier => True);
3057 -- When the transient scope was established, we pushed the entry for
3058 -- the transient scope onto the scope stack, so that the scope was
3059 -- active for the installation of finalizable entities etc. Now we
3060 -- must remove this entry, since we have constructed a proper block.
3065 end Make_Transient_Block;
3067 ------------------------
3068 -- Node_To_Be_Wrapped --
3069 ------------------------
3071 function Node_To_Be_Wrapped return Node_Id is
3073 return Scope_Stack.Table (Scope_Stack.Last).Node_To_Be_Wrapped;
3074 end Node_To_Be_Wrapped;
3076 ----------------------------
3077 -- Set_Node_To_Be_Wrapped --
3078 ----------------------------
3080 procedure Set_Node_To_Be_Wrapped (N : Node_Id) is
3082 Scope_Stack.Table (Scope_Stack.Last).Node_To_Be_Wrapped := N;
3083 end Set_Node_To_Be_Wrapped;
3085 ----------------------------------
3086 -- Store_After_Actions_In_Scope --
3087 ----------------------------------
3089 procedure Store_After_Actions_In_Scope (L : List_Id) is
3090 SE : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
3093 if Present (SE.Actions_To_Be_Wrapped_After) then
3094 Insert_List_Before_And_Analyze (
3095 First (SE.Actions_To_Be_Wrapped_After), L);
3098 SE.Actions_To_Be_Wrapped_After := L;
3100 if Is_List_Member (SE.Node_To_Be_Wrapped) then
3101 Set_Parent (L, Parent (SE.Node_To_Be_Wrapped));
3103 Set_Parent (L, SE.Node_To_Be_Wrapped);
3108 end Store_After_Actions_In_Scope;
3110 -----------------------------------
3111 -- Store_Before_Actions_In_Scope --
3112 -----------------------------------
3114 procedure Store_Before_Actions_In_Scope (L : List_Id) is
3115 SE : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
3118 if Present (SE.Actions_To_Be_Wrapped_Before) then
3119 Insert_List_After_And_Analyze (
3120 Last (SE.Actions_To_Be_Wrapped_Before), L);
3123 SE.Actions_To_Be_Wrapped_Before := L;
3125 if Is_List_Member (SE.Node_To_Be_Wrapped) then
3126 Set_Parent (L, Parent (SE.Node_To_Be_Wrapped));
3128 Set_Parent (L, SE.Node_To_Be_Wrapped);
3133 end Store_Before_Actions_In_Scope;
3135 --------------------------------
3136 -- Wrap_Transient_Declaration --
3137 --------------------------------
3139 -- If a transient scope has been established during the processing of the
3140 -- Expression of an Object_Declaration, it is not possible to wrap the
3141 -- declaration into a transient block as usual case, otherwise the object
3142 -- would be itself declared in the wrong scope. Therefore, all entities (if
3143 -- any) defined in the transient block are moved to the proper enclosing
3144 -- scope, furthermore, if they are controlled variables they are finalized
3145 -- right after the declaration. The finalization list of the transient
3146 -- scope is defined as a renaming of the enclosing one so during their
3147 -- initialization they will be attached to the proper finalization
3148 -- list. For instance, the following declaration :
3150 -- X : Typ := F (G (A), G (B));
3152 -- (where G(A) and G(B) return controlled values, expanded as _v1 and _v2)
3153 -- is expanded into :
3155 -- _local_final_list_1 : Finalizable_Ptr;
3156 -- X : Typ := [ complex Expression-Action ];
3157 -- Finalize_One(_v1);
3158 -- Finalize_One (_v2);
3160 procedure Wrap_Transient_Declaration (N : Node_Id) is
3162 LC : Entity_Id := Empty;
3164 Loc : constant Source_Ptr := Sloc (N);
3165 Enclosing_S : Entity_Id;
3167 Next_N : constant Node_Id := Next (N);
3171 Enclosing_S := Scope (S);
3173 -- Insert Actions kept in the Scope stack
3175 Insert_Actions_In_Scope_Around (N);
3177 -- If the declaration is consuming some secondary stack, mark the
3178 -- Enclosing scope appropriately.
3180 Uses_SS := Uses_Sec_Stack (S);
3183 -- Create a List controller and rename the final list to be its
3184 -- internal final pointer:
3185 -- Lxxx : Simple_List_Controller;
3186 -- Fxxx : Finalizable_Ptr renames Lxxx.F;
3188 if Present (Finalization_Chain_Entity (S)) then
3189 LC := Make_Defining_Identifier (Loc, New_Internal_Name ('L'));
3192 Make_Object_Declaration (Loc,
3193 Defining_Identifier => LC,
3194 Object_Definition =>
3195 New_Reference_To (RTE (RE_Simple_List_Controller), Loc)),
3197 Make_Object_Renaming_Declaration (Loc,
3198 Defining_Identifier => Finalization_Chain_Entity (S),
3199 Subtype_Mark => New_Reference_To (RTE (RE_Finalizable_Ptr), Loc),
3201 Make_Selected_Component (Loc,
3202 Prefix => New_Reference_To (LC, Loc),
3203 Selector_Name => Make_Identifier (Loc, Name_F))));
3205 -- Put the declaration at the beginning of the declaration part
3206 -- to make sure it will be before all other actions that have been
3207 -- inserted before N.
3209 Insert_List_Before_And_Analyze (First (List_Containing (N)), Nodes);
3211 -- Generate the Finalization calls by finalizing the list
3212 -- controller right away. It will be re-finalized on scope
3213 -- exit but it doesn't matter. It cannot be done when the
3214 -- call initializes a renaming object though because in this
3215 -- case, the object becomes a pointer to the temporary and thus
3216 -- increases its life span.
3218 if Nkind (N) = N_Object_Renaming_Declaration
3219 and then Controlled_Type (Etype (Defining_Identifier (N)))
3226 Ref => New_Reference_To (LC, Loc),
3228 With_Detach => New_Reference_To (Standard_False, Loc));
3229 if Present (Next_N) then
3230 Insert_List_Before_And_Analyze (Next_N, Nodes);
3232 Append_List_To (List_Containing (N), Nodes);
3237 -- Put the local entities back in the enclosing scope, and set the
3238 -- Is_Public flag appropriately.
3240 Transfer_Entities (S, Enclosing_S);
3242 -- Mark the enclosing dynamic scope so that the sec stack will be
3243 -- released upon its exit unless this is a function that returns on
3244 -- the sec stack in which case this will be done by the caller.
3247 S := Enclosing_Dynamic_Scope (S);
3249 if Ekind (S) = E_Function
3250 and then Requires_Transient_Scope (Etype (S))
3254 Set_Uses_Sec_Stack (S);
3255 Check_Restriction (No_Secondary_Stack, N);
3258 end Wrap_Transient_Declaration;
3260 -------------------------------
3261 -- Wrap_Transient_Expression --
3262 -------------------------------
3264 -- Insert actions before <Expression>:
3266 -- (lines marked with <CTRL> are expanded only in presence of Controlled
3267 -- objects needing finalization)
3271 -- _M : constant Mark_Id := SS_Mark;
3272 -- Local_Final_List : System.FI.Finalizable_Ptr; <CTRL>
3274 -- procedure _Clean is
3277 -- System.FI.Finalize_List (Local_Final_List); <CTRL>
3283 -- _E := <Expression>;
3288 -- then expression is replaced by _E
3290 procedure Wrap_Transient_Expression (N : Node_Id) is
3291 Loc : constant Source_Ptr := Sloc (N);
3292 E : constant Entity_Id :=
3293 Make_Defining_Identifier (Loc, New_Internal_Name ('E'));
3294 Etyp : constant Entity_Id := Etype (N);
3297 Insert_Actions (N, New_List (
3298 Make_Object_Declaration (Loc,
3299 Defining_Identifier => E,
3300 Object_Definition => New_Reference_To (Etyp, Loc)),
3302 Make_Transient_Block (Loc,
3304 Make_Assignment_Statement (Loc,
3305 Name => New_Reference_To (E, Loc),
3306 Expression => Relocate_Node (N)))));
3308 Rewrite (N, New_Reference_To (E, Loc));
3309 Analyze_And_Resolve (N, Etyp);
3310 end Wrap_Transient_Expression;
3312 ------------------------------
3313 -- Wrap_Transient_Statement --
3314 ------------------------------
3316 -- Transform <Instruction> into
3318 -- (lines marked with <CTRL> are expanded only in presence of Controlled
3319 -- objects needing finalization)
3322 -- _M : Mark_Id := SS_Mark;
3323 -- Local_Final_List : System.FI.Finalizable_Ptr ; <CTRL>
3325 -- procedure _Clean is
3328 -- System.FI.Finalize_List (Local_Final_List); <CTRL>
3339 procedure Wrap_Transient_Statement (N : Node_Id) is
3340 Loc : constant Source_Ptr := Sloc (N);
3341 New_Statement : constant Node_Id := Relocate_Node (N);
3344 Rewrite (N, Make_Transient_Block (Loc, New_Statement));
3346 -- With the scope stack back to normal, we can call analyze on the
3347 -- resulting block. At this point, the transient scope is being
3348 -- treated like a perfectly normal scope, so there is nothing
3349 -- special about it.
3351 -- Note: Wrap_Transient_Statement is called with the node already
3352 -- analyzed (i.e. Analyzed (N) is True). This is important, since
3353 -- otherwise we would get a recursive processing of the node when
3354 -- we do this Analyze call.
3357 end Wrap_Transient_Statement;