1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2008, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 ------------------------------------------------------------------------------
26 -- This package contains virtually all expansion mechanisms related to
30 with Atree; use Atree;
31 with Debug; use Debug;
32 with Einfo; use Einfo;
33 with Errout; use Errout;
34 with Exp_Ch9; use Exp_Ch9;
35 with Exp_Ch11; use Exp_Ch11;
36 with Exp_Dbug; use Exp_Dbug;
37 with Exp_Dist; use Exp_Dist;
38 with Exp_Disp; use Exp_Disp;
39 with Exp_Tss; use Exp_Tss;
40 with Exp_Util; use Exp_Util;
41 with Freeze; use Freeze;
43 with Nlists; use Nlists;
44 with Nmake; use Nmake;
46 with Output; use Output;
47 with Restrict; use Restrict;
48 with Rident; use Rident;
49 with Rtsfind; use Rtsfind;
50 with Sinfo; use Sinfo;
52 with Sem_Aux; use Sem_Aux;
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 Targparm; use Targparm;
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 functions returning tagged types: It has been decided to
95 -- always allocate their result in the secondary stack, even though 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. An exception to this is when the function
99 -- builds its result in place, as is done for functions with inherently
100 -- limited result types for Ada 2005. In that case, certain callers may
101 -- pass the address of a constrained object as the target object for the
104 -- By allocating tagged results in the secondary stack a number of
105 -- implementation difficulties are avoided:
107 -- - If it is a dispatching function call, the computation of the size of
108 -- the result is possible but complex from the outside.
110 -- - If the returned type is controlled, the assignment of the returned
111 -- value to the anonymous object involves an Adjust, and we have no
112 -- easy way to access the anonymous object created by the back end.
114 -- - If the returned type is class-wide, this is an unconstrained type
117 -- Furthermore, the small loss in efficiency which is the result of this
118 -- decision is not such a big deal because functions returning tagged types
119 -- are not as common in practice compared to functions returning access to
122 --------------------------------------------------
123 -- Transient Blocks and Finalization Management --
124 --------------------------------------------------
126 function Find_Node_To_Be_Wrapped (N : Node_Id) return Node_Id;
127 -- N is a node which may generate a transient scope. Loop over the
128 -- parent pointers of N until it find the appropriate node to
129 -- wrap. It it returns Empty, it means that no transient scope is
130 -- needed in this context.
139 Is_Protected_Subprogram : Boolean;
140 Is_Task_Allocation_Block : Boolean;
141 Is_Asynchronous_Call_Block : Boolean;
142 Chained_Cleanup_Action : Node_Id) return Node_Id;
143 -- Expand the clean-up procedure for a controlled and/or transient block,
144 -- and/or task master or task body, or a block used to implement task
145 -- allocation or asynchronous entry calls, or a procedure used to implement
146 -- protected procedures. Clean is the entity for such a procedure. Mark
147 -- is the entity for the secondary stack mark, if empty only controlled
148 -- block clean-up will be performed. Flist is the entity for the local
149 -- final list, if empty only transient scope clean-up will be performed.
150 -- The flags Is_Task and Is_Master control the calls to the corresponding
151 -- finalization actions for a task body or for an entity that is a task
152 -- master. Finally if Chained_Cleanup_Action is present, it is a reference
153 -- to a previous cleanup procedure, a call to which is appended at the
154 -- end of the generated one.
156 procedure Set_Node_To_Be_Wrapped (N : Node_Id);
157 -- Set the field Node_To_Be_Wrapped of the current scope
159 procedure Insert_Actions_In_Scope_Around (N : Node_Id);
160 -- Insert the before-actions kept in the scope stack before N, and the
161 -- after after-actions, after N which must be a member of a list.
163 function Make_Transient_Block
165 Action : Node_Id) return Node_Id;
166 -- Create a transient block whose name is Scope, which is also a
167 -- controlled block if Flist is not empty and whose only code is
168 -- Action (either a single statement or single declaration).
170 type Final_Primitives is (Initialize_Case, Adjust_Case, Finalize_Case);
171 -- This enumeration type is defined in order to ease sharing code for
172 -- building finalization procedures for composite types.
174 Name_Of : constant array (Final_Primitives) of Name_Id :=
175 (Initialize_Case => Name_Initialize,
176 Adjust_Case => Name_Adjust,
177 Finalize_Case => Name_Finalize);
179 Deep_Name_Of : constant array (Final_Primitives) of TSS_Name_Type :=
180 (Initialize_Case => TSS_Deep_Initialize,
181 Adjust_Case => TSS_Deep_Adjust,
182 Finalize_Case => TSS_Deep_Finalize);
184 procedure Build_Record_Deep_Procs (Typ : Entity_Id);
185 -- Build the deep Initialize/Adjust/Finalize for a record Typ with
186 -- Has_Component_Component set and store them using the TSS mechanism.
188 procedure Build_Array_Deep_Procs (Typ : Entity_Id);
189 -- Build the deep Initialize/Adjust/Finalize for a record Typ with
190 -- Has_Controlled_Component set and store them using the TSS mechanism.
192 function Make_Deep_Proc
193 (Prim : Final_Primitives;
195 Stmts : List_Id) return Node_Id;
196 -- This function generates the tree for Deep_Initialize, Deep_Adjust
197 -- or Deep_Finalize procedures according to the first parameter,
198 -- these procedures operate on the type Typ. The Stmts parameter
199 -- gives the body of the procedure.
201 function Make_Deep_Array_Body
202 (Prim : Final_Primitives;
203 Typ : Entity_Id) return List_Id;
204 -- This function generates the list of statements for implementing
205 -- Deep_Initialize, Deep_Adjust or Deep_Finalize procedures
206 -- according to the first parameter, these procedures operate on the
209 function Make_Deep_Record_Body
210 (Prim : Final_Primitives;
211 Typ : Entity_Id) return List_Id;
212 -- This function generates the list of statements for implementing
213 -- Deep_Initialize, Deep_Adjust or Deep_Finalize procedures
214 -- according to the first parameter, these procedures operate on the
217 procedure Check_Visibly_Controlled
218 (Prim : Final_Primitives;
220 E : in out Entity_Id;
221 Cref : in out Node_Id);
222 -- The controlled operation declared for a derived type may not be
223 -- overriding, if the controlled operations of the parent type are
224 -- hidden, for example when the parent is a private type whose full
225 -- view is controlled. For other primitive operations we modify the
226 -- name of the operation to indicate that it is not overriding, but
227 -- this is not possible for Initialize, etc. because they have to be
228 -- retrievable by name. Before generating the proper call to one of
229 -- these operations we check whether Typ is known to be controlled at
230 -- the point of definition. If it is not then we must retrieve the
231 -- hidden operation of the parent and use it instead. This is one
232 -- case that might be solved more cleanly once Overriding pragmas or
233 -- declarations are in place.
235 function Convert_View
238 Ind : Pos := 1) return Node_Id;
239 -- Proc is one of the Initialize/Adjust/Finalize operations, and
240 -- Arg is the argument being passed to it. Ind indicates which
241 -- formal of procedure Proc we are trying to match. This function
242 -- will, if necessary, generate an conversion between the partial
243 -- and full view of Arg to match the type of the formal of Proc,
244 -- or force a conversion to the class-wide type in the case where
245 -- the operation is abstract.
247 -----------------------------
248 -- Finalization Management --
249 -----------------------------
251 -- This part describe how Initialization/Adjustment/Finalization procedures
252 -- are generated and called. Two cases must be considered, types that are
253 -- Controlled (Is_Controlled flag set) and composite types that contain
254 -- controlled components (Has_Controlled_Component flag set). In the first
255 -- case the procedures to call are the user-defined primitive operations
256 -- Initialize/Adjust/Finalize. In the second case, GNAT generates
257 -- Deep_Initialize, Deep_Adjust and Deep_Finalize that are in charge
258 -- of calling the former procedures on the controlled components.
260 -- For records with Has_Controlled_Component set, a hidden "controller"
261 -- component is inserted. This controller component contains its own
262 -- finalization list on which all controlled components are attached
263 -- creating an indirection on the upper-level Finalization list. This
264 -- technique facilitates the management of objects whose number of
265 -- controlled components changes during execution. This controller
266 -- component is itself controlled and is attached to the upper-level
267 -- finalization chain. Its adjust primitive is in charge of calling adjust
268 -- on the components and adjusting the finalization pointer to match their
269 -- new location (see a-finali.adb).
271 -- It is not possible to use a similar technique for arrays that have
272 -- Has_Controlled_Component set. In this case, deep procedures are
273 -- generated that call initialize/adjust/finalize + attachment or
274 -- detachment on the finalization list for all component.
276 -- Initialize calls: they are generated for declarations or dynamic
277 -- allocations of Controlled objects with no initial value. They are always
278 -- followed by an attachment to the current Finalization Chain. For the
279 -- dynamic allocation case this the chain attached to the scope of the
280 -- access type definition otherwise, this is the chain of the current
283 -- Adjust Calls: They are generated on 2 occasions: (1) for
284 -- declarations or dynamic allocations of Controlled objects with an
285 -- initial value. (2) after an assignment. In the first case they are
286 -- followed by an attachment to the final chain, in the second case
289 -- Finalization Calls: They are generated on (1) scope exit, (2)
290 -- assignments, (3) unchecked deallocations. In case (3) they have to
291 -- be detached from the final chain, in case (2) they must not and in
292 -- case (1) this is not important since we are exiting the scope anyway.
296 -- Type extensions will have a new record controller at each derivation
297 -- level containing controlled components. The record controller for
298 -- the parent/ancestor is attached to the finalization list of the
299 -- extension's record controller (i.e. the parent is like a component
300 -- of the extension).
302 -- For types that are both Is_Controlled and Has_Controlled_Components,
303 -- the record controller and the object itself are handled separately.
304 -- It could seem simpler to attach the object at the end of its record
305 -- controller but this would not tackle view conversions properly.
307 -- A classwide type can always potentially have controlled components
308 -- but the record controller of the corresponding actual type may not
309 -- be known at compile time so the dispatch table contains a special
310 -- field that allows to compute the offset of the record controller
311 -- dynamically. See s-finimp.Deep_Tag_Attach and a-tags.RC_Offset.
313 -- Here is a simple example of the expansion of a controlled block :
317 -- Y : Controlled := Init;
323 -- Z : R := (C => X);
332 -- _L : System.FI.Finalizable_Ptr;
334 -- procedure _Clean is
337 -- System.FI.Finalize_List (_L);
345 -- Attach_To_Final_List (_L, Finalizable (X), 1);
346 -- at end: Abort_Undefer;
347 -- Y : Controlled := Init;
349 -- Attach_To_Final_List (_L, Finalizable (Y), 1);
352 -- _C : Record_Controller;
358 -- Deep_Initialize (W, _L, 1);
359 -- at end: Abort_Under;
360 -- Z : R := (C => X);
361 -- Deep_Adjust (Z, _L, 1);
365 -- Deep_Finalize (W, False);
366 -- <save W's final pointers>
368 -- <restore W's final pointers>
369 -- Deep_Adjust (W, _L, 0);
374 function Global_Flist_Ref (Flist_Ref : Node_Id) return Boolean;
375 -- Return True if Flist_Ref refers to a global final list, either the
376 -- object Global_Final_List which is used to attach standalone objects,
377 -- or any of the list controllers associated with library-level access
378 -- to controlled objects.
380 procedure Clean_Simple_Protected_Objects (N : Node_Id);
381 -- Protected objects without entries are not controlled types, and the
382 -- locks have to be released explicitly when such an object goes out
383 -- of scope. Traverse declarations in scope to determine whether such
384 -- objects are present.
386 ----------------------------
387 -- Build_Array_Deep_Procs --
388 ----------------------------
390 procedure Build_Array_Deep_Procs (Typ : Entity_Id) is
394 Prim => Initialize_Case,
396 Stmts => Make_Deep_Array_Body (Initialize_Case, Typ)));
398 if not Is_Inherently_Limited_Type (Typ) then
403 Stmts => Make_Deep_Array_Body (Adjust_Case, Typ)));
408 Prim => Finalize_Case,
410 Stmts => Make_Deep_Array_Body (Finalize_Case, Typ)));
411 end Build_Array_Deep_Procs;
413 -----------------------------
414 -- Build_Controlling_Procs --
415 -----------------------------
417 procedure Build_Controlling_Procs (Typ : Entity_Id) is
419 if Is_Array_Type (Typ) then
420 Build_Array_Deep_Procs (Typ);
422 else pragma Assert (Is_Record_Type (Typ));
423 Build_Record_Deep_Procs (Typ);
425 end Build_Controlling_Procs;
427 ----------------------
428 -- Build_Final_List --
429 ----------------------
431 procedure Build_Final_List (N : Node_Id; Typ : Entity_Id) is
432 Loc : constant Source_Ptr := Sloc (N);
436 Set_Associated_Final_Chain (Typ,
437 Make_Defining_Identifier (Loc,
438 New_External_Name (Chars (Typ), 'L')));
441 Make_Object_Declaration (Loc,
442 Defining_Identifier =>
443 Associated_Final_Chain (Typ),
446 (RTE (RE_List_Controller), Loc));
448 -- The type may have been frozen already, and this is a late freezing
449 -- action, in which case the declaration must be elaborated at once.
450 -- If the call is for an allocator, the chain must also be created now,
451 -- because the freezing of the type does not build one. Otherwise, the
452 -- declaration is one of the freezing actions for a user-defined type.
455 or else (Nkind (N) = N_Allocator
456 and then Ekind (Etype (N)) = E_Anonymous_Access_Type)
458 Insert_Action (N, Decl);
460 Append_Freeze_Action (Typ, Decl);
462 end Build_Final_List;
464 ---------------------
465 -- Build_Late_Proc --
466 ---------------------
468 procedure Build_Late_Proc (Typ : Entity_Id; Nam : Name_Id) is
470 for Final_Prim in Name_Of'Range loop
471 if Name_Of (Final_Prim) = Nam then
476 Stmts => Make_Deep_Record_Body (Final_Prim, Typ)));
481 -----------------------------
482 -- Build_Record_Deep_Procs --
483 -----------------------------
485 procedure Build_Record_Deep_Procs (Typ : Entity_Id) is
489 Prim => Initialize_Case,
491 Stmts => Make_Deep_Record_Body (Initialize_Case, Typ)));
493 if not Is_Inherently_Limited_Type (Typ) then
498 Stmts => Make_Deep_Record_Body (Adjust_Case, Typ)));
503 Prim => Finalize_Case,
505 Stmts => Make_Deep_Record_Body (Finalize_Case, Typ)));
506 end Build_Record_Deep_Procs;
512 function Cleanup_Array
515 Typ : Entity_Id) return List_Id
517 Loc : constant Source_Ptr := Sloc (N);
518 Index_List : constant List_Id := New_List;
520 function Free_Component return List_Id;
521 -- Generate the code to finalize the task or protected subcomponents
522 -- of a single component of the array.
524 function Free_One_Dimension (Dim : Int) return List_Id;
525 -- Generate a loop over one dimension of the array
531 function Free_Component return List_Id is
532 Stmts : List_Id := New_List;
534 C_Typ : constant Entity_Id := Component_Type (Typ);
537 -- Component type is known to contain tasks or protected objects
540 Make_Indexed_Component (Loc,
541 Prefix => Duplicate_Subexpr_No_Checks (Obj),
542 Expressions => Index_List);
544 Set_Etype (Tsk, C_Typ);
546 if Is_Task_Type (C_Typ) then
547 Append_To (Stmts, Cleanup_Task (N, Tsk));
549 elsif Is_Simple_Protected_Type (C_Typ) then
550 Append_To (Stmts, Cleanup_Protected_Object (N, Tsk));
552 elsif Is_Record_Type (C_Typ) then
553 Stmts := Cleanup_Record (N, Tsk, C_Typ);
555 elsif Is_Array_Type (C_Typ) then
556 Stmts := Cleanup_Array (N, Tsk, C_Typ);
562 ------------------------
563 -- Free_One_Dimension --
564 ------------------------
566 function Free_One_Dimension (Dim : Int) return List_Id is
570 if Dim > Number_Dimensions (Typ) then
571 return Free_Component;
573 -- Here we generate the required loop
577 Make_Defining_Identifier (Loc, New_Internal_Name ('J'));
579 Append (New_Reference_To (Index, Loc), Index_List);
582 Make_Implicit_Loop_Statement (N,
585 Make_Iteration_Scheme (Loc,
586 Loop_Parameter_Specification =>
587 Make_Loop_Parameter_Specification (Loc,
588 Defining_Identifier => Index,
589 Discrete_Subtype_Definition =>
590 Make_Attribute_Reference (Loc,
591 Prefix => Duplicate_Subexpr (Obj),
592 Attribute_Name => Name_Range,
593 Expressions => New_List (
594 Make_Integer_Literal (Loc, Dim))))),
595 Statements => Free_One_Dimension (Dim + 1)));
597 end Free_One_Dimension;
599 -- Start of processing for Cleanup_Array
602 return Free_One_Dimension (1);
609 function Cleanup_Record
612 Typ : Entity_Id) return List_Id
614 Loc : constant Source_Ptr := Sloc (N);
617 Stmts : constant List_Id := New_List;
618 U_Typ : constant Entity_Id := Underlying_Type (Typ);
621 if Has_Discriminants (U_Typ)
622 and then Nkind (Parent (U_Typ)) = N_Full_Type_Declaration
624 Nkind (Type_Definition (Parent (U_Typ))) = N_Record_Definition
628 (Component_List (Type_Definition (Parent (U_Typ)))))
630 -- For now, do not attempt to free a component that may appear in
631 -- a variant, and instead issue a warning. Doing this "properly"
632 -- would require building a case statement and would be quite a
633 -- mess. Note that the RM only requires that free "work" for the
634 -- case of a task access value, so already we go way beyond this
635 -- in that we deal with the array case and non-discriminated
639 ("task/protected object in variant record will not be freed?", N);
640 return New_List (Make_Null_Statement (Loc));
643 Comp := First_Component (Typ);
645 while Present (Comp) loop
646 if Has_Task (Etype (Comp))
647 or else Has_Simple_Protected_Object (Etype (Comp))
650 Make_Selected_Component (Loc,
651 Prefix => Duplicate_Subexpr_No_Checks (Obj),
652 Selector_Name => New_Occurrence_Of (Comp, Loc));
653 Set_Etype (Tsk, Etype (Comp));
655 if Is_Task_Type (Etype (Comp)) then
656 Append_To (Stmts, Cleanup_Task (N, Tsk));
658 elsif Is_Simple_Protected_Type (Etype (Comp)) then
659 Append_To (Stmts, Cleanup_Protected_Object (N, Tsk));
661 elsif Is_Record_Type (Etype (Comp)) then
663 -- Recurse, by generating the prefix of the argument to
664 -- the eventual cleanup call.
667 (Stmts, Cleanup_Record (N, Tsk, Etype (Comp)));
669 elsif Is_Array_Type (Etype (Comp)) then
671 (Stmts, Cleanup_Array (N, Tsk, Etype (Comp)));
675 Next_Component (Comp);
681 ------------------------------
682 -- Cleanup_Protected_Object --
683 ------------------------------
685 function Cleanup_Protected_Object
687 Ref : Node_Id) return Node_Id
689 Loc : constant Source_Ptr := Sloc (N);
693 Make_Procedure_Call_Statement (Loc,
694 Name => New_Reference_To (RTE (RE_Finalize_Protection), Loc),
695 Parameter_Associations => New_List (
696 Concurrent_Ref (Ref)));
697 end Cleanup_Protected_Object;
699 ------------------------------------
700 -- Clean_Simple_Protected_Objects --
701 ------------------------------------
703 procedure Clean_Simple_Protected_Objects (N : Node_Id) is
704 Stmts : constant List_Id := Statements (Handled_Statement_Sequence (N));
705 Stmt : Node_Id := Last (Stmts);
709 E := First_Entity (Current_Scope);
710 while Present (E) loop
711 if (Ekind (E) = E_Variable
712 or else Ekind (E) = E_Constant)
713 and then Has_Simple_Protected_Object (Etype (E))
714 and then not Has_Task (Etype (E))
715 and then Nkind (Parent (E)) /= N_Object_Renaming_Declaration
718 Typ : constant Entity_Id := Etype (E);
719 Ref : constant Node_Id := New_Occurrence_Of (E, Sloc (Stmt));
722 if Is_Simple_Protected_Type (Typ) then
723 Append_To (Stmts, Cleanup_Protected_Object (N, Ref));
725 elsif Has_Simple_Protected_Object (Typ) then
726 if Is_Record_Type (Typ) then
727 Append_List_To (Stmts, Cleanup_Record (N, Ref, Typ));
729 elsif Is_Array_Type (Typ) then
730 Append_List_To (Stmts, Cleanup_Array (N, Ref, Typ));
739 -- Analyze inserted cleanup statements
741 if Present (Stmt) then
744 while Present (Stmt) loop
749 end Clean_Simple_Protected_Objects;
755 function Cleanup_Task
757 Ref : Node_Id) return Node_Id
759 Loc : constant Source_Ptr := Sloc (N);
762 Make_Procedure_Call_Statement (Loc,
763 Name => New_Reference_To (RTE (RE_Free_Task), Loc),
764 Parameter_Associations =>
765 New_List (Concurrent_Ref (Ref)));
768 ---------------------------------
769 -- Has_Simple_Protected_Object --
770 ---------------------------------
772 function Has_Simple_Protected_Object (T : Entity_Id) return Boolean is
776 if Is_Simple_Protected_Type (T) then
779 elsif Is_Array_Type (T) then
780 return Has_Simple_Protected_Object (Component_Type (T));
782 elsif Is_Record_Type (T) then
783 Comp := First_Component (T);
785 while Present (Comp) loop
786 if Has_Simple_Protected_Object (Etype (Comp)) then
790 Next_Component (Comp);
798 end Has_Simple_Protected_Object;
800 ------------------------------
801 -- Is_Simple_Protected_Type --
802 ------------------------------
804 function Is_Simple_Protected_Type (T : Entity_Id) return Boolean is
806 return Is_Protected_Type (T) and then not Has_Entries (T);
807 end Is_Simple_Protected_Type;
809 ------------------------------
810 -- Check_Visibly_Controlled --
811 ------------------------------
813 procedure Check_Visibly_Controlled
814 (Prim : Final_Primitives;
816 E : in out Entity_Id;
817 Cref : in out Node_Id)
819 Parent_Type : Entity_Id;
823 if Is_Derived_Type (Typ)
824 and then Comes_From_Source (E)
825 and then not Is_Overriding_Operation (E)
827 -- We know that the explicit operation on the type does not override
828 -- the inherited operation of the parent, and that the derivation
829 -- is from a private type that is not visibly controlled.
831 Parent_Type := Etype (Typ);
832 Op := Find_Prim_Op (Parent_Type, Name_Of (Prim));
837 -- Wrap the object to be initialized into the proper
838 -- unchecked conversion, to be compatible with the operation
841 if Nkind (Cref) = N_Unchecked_Type_Conversion then
842 Cref := Unchecked_Convert_To (Parent_Type, Expression (Cref));
844 Cref := Unchecked_Convert_To (Parent_Type, Cref);
848 end Check_Visibly_Controlled;
850 -------------------------------
851 -- CW_Or_Has_Controlled_Part --
852 -------------------------------
854 function CW_Or_Has_Controlled_Part (T : Entity_Id) return Boolean is
856 return Is_Class_Wide_Type (T) or else Needs_Finalization (T);
857 end CW_Or_Has_Controlled_Part;
859 --------------------------
860 -- Controller_Component --
861 --------------------------
863 function Controller_Component (Typ : Entity_Id) return Entity_Id is
864 T : Entity_Id := Base_Type (Typ);
866 Comp_Scop : Entity_Id;
867 Res : Entity_Id := Empty;
868 Res_Scop : Entity_Id := Empty;
871 if Is_Class_Wide_Type (T) then
875 if Is_Private_Type (T) then
876 T := Underlying_Type (T);
879 -- Fetch the outermost controller
881 Comp := First_Entity (T);
882 while Present (Comp) loop
883 if Chars (Comp) = Name_uController then
884 Comp_Scop := Scope (Original_Record_Component (Comp));
886 -- If this controller is at the outermost level, no need to
887 -- look for another one
889 if Comp_Scop = T then
892 -- Otherwise record the outermost one and continue looking
894 elsif Res = Empty or else Is_Ancestor (Res_Scop, Comp_Scop) then
896 Res_Scop := Comp_Scop;
903 -- If we fall through the loop, there is no controller component
906 end Controller_Component;
912 function Convert_View
915 Ind : Pos := 1) return Node_Id
917 Fent : Entity_Id := First_Entity (Proc);
922 for J in 2 .. Ind loop
926 Ftyp := Etype (Fent);
928 if Nkind_In (Arg, N_Type_Conversion, N_Unchecked_Type_Conversion) then
929 Atyp := Entity (Subtype_Mark (Arg));
934 if Is_Abstract_Subprogram (Proc) and then Is_Tagged_Type (Ftyp) then
935 return Unchecked_Convert_To (Class_Wide_Type (Ftyp), Arg);
938 and then Present (Atyp)
940 (Is_Private_Type (Ftyp) or else Is_Private_Type (Atyp))
942 Base_Type (Underlying_Type (Atyp)) =
943 Base_Type (Underlying_Type (Ftyp))
945 return Unchecked_Convert_To (Ftyp, Arg);
947 -- If the argument is already a conversion, as generated by
948 -- Make_Init_Call, set the target type to the type of the formal
949 -- directly, to avoid spurious typing problems.
951 elsif Nkind_In (Arg, N_Unchecked_Type_Conversion, N_Type_Conversion)
952 and then not Is_Class_Wide_Type (Atyp)
954 Set_Subtype_Mark (Arg, New_Occurrence_Of (Ftyp, Sloc (Arg)));
955 Set_Etype (Arg, Ftyp);
963 -------------------------------
964 -- Establish_Transient_Scope --
965 -------------------------------
967 -- This procedure is called each time a transient block has to be inserted
968 -- that is to say for each call to a function with unconstrained or tagged
969 -- result. It creates a new scope on the stack scope in order to enclose
970 -- all transient variables generated
972 procedure Establish_Transient_Scope (N : Node_Id; Sec_Stack : Boolean) is
973 Loc : constant Source_Ptr := Sloc (N);
977 -- Nothing to do for virtual machines where memory is GCed
979 if VM_Target /= No_VM then
983 -- Do not create a transient scope if we are already inside one
985 for S in reverse Scope_Stack.First .. Scope_Stack.Last loop
986 if Scope_Stack.Table (S).Is_Transient then
988 Set_Uses_Sec_Stack (Scope_Stack.Table (S).Entity);
993 -- If we have encountered Standard there are no enclosing
996 elsif Scope_Stack.Table (S).Entity = Standard_Standard then
1002 Wrap_Node := Find_Node_To_Be_Wrapped (N);
1004 -- Case of no wrap node, false alert, no transient scope needed
1006 if No (Wrap_Node) then
1009 -- If the node to wrap is an iteration_scheme, the expression is
1010 -- one of the bounds, and the expansion will make an explicit
1011 -- declaration for it (see Analyze_Iteration_Scheme, sem_ch5.adb),
1012 -- so do not apply any transformations here.
1014 elsif Nkind (Wrap_Node) = N_Iteration_Scheme then
1018 Push_Scope (New_Internal_Entity (E_Block, Current_Scope, Loc, 'B'));
1019 Set_Scope_Is_Transient;
1022 Set_Uses_Sec_Stack (Current_Scope);
1023 Check_Restriction (No_Secondary_Stack, N);
1026 Set_Etype (Current_Scope, Standard_Void_Type);
1027 Set_Node_To_Be_Wrapped (Wrap_Node);
1029 if Debug_Flag_W then
1030 Write_Str (" <Transient>");
1034 end Establish_Transient_Scope;
1036 ----------------------------
1037 -- Expand_Cleanup_Actions --
1038 ----------------------------
1040 procedure Expand_Cleanup_Actions (N : Node_Id) is
1041 S : constant Entity_Id := Current_Scope;
1042 Flist : constant Entity_Id := Finalization_Chain_Entity (S);
1043 Is_Task : constant Boolean := Nkind (Original_Node (N)) = N_Task_Body;
1045 Is_Master : constant Boolean :=
1046 Nkind (N) /= N_Entry_Body
1047 and then Is_Task_Master (N);
1048 Is_Protected : constant Boolean :=
1049 Nkind (N) = N_Subprogram_Body
1050 and then Is_Protected_Subprogram_Body (N);
1051 Is_Task_Allocation : constant Boolean :=
1052 Nkind (N) = N_Block_Statement
1053 and then Is_Task_Allocation_Block (N);
1054 Is_Asynchronous_Call : constant Boolean :=
1055 Nkind (N) = N_Block_Statement
1056 and then Is_Asynchronous_Call_Block (N);
1058 Previous_At_End_Proc : constant Node_Id :=
1059 At_End_Proc (Handled_Statement_Sequence (N));
1063 Mark : Entity_Id := Empty;
1064 New_Decls : constant List_Id := New_List;
1068 Chain : Entity_Id := Empty;
1073 -- If we are generating expanded code for debugging purposes, use
1074 -- the Sloc of the point of insertion for the cleanup code. The Sloc
1075 -- will be updated subsequently to reference the proper line in the
1076 -- .dg file. If we are not debugging generated code, use instead
1077 -- No_Location, so that no debug information is generated for the
1078 -- cleanup code. This makes the behavior of the NEXT command in GDB
1079 -- monotonic, and makes the placement of breakpoints more accurate.
1081 if Debug_Generated_Code then
1087 -- There are cleanup actions only if the secondary stack needs
1088 -- releasing or some finalizations are needed or in the context
1091 if Uses_Sec_Stack (Current_Scope)
1092 and then not Sec_Stack_Needed_For_Return (Current_Scope)
1096 and then not Is_Master
1097 and then not Is_Task
1098 and then not Is_Protected
1099 and then not Is_Task_Allocation
1100 and then not Is_Asynchronous_Call
1102 Clean_Simple_Protected_Objects (N);
1106 -- If the current scope is the subprogram body that is the rewriting
1107 -- of a task body, and the descriptors have not been delayed (due to
1108 -- some nested instantiations) do not generate redundant cleanup
1109 -- actions: the cleanup procedure already exists for this body.
1111 if Nkind (N) = N_Subprogram_Body
1112 and then Nkind (Original_Node (N)) = N_Task_Body
1113 and then not Delay_Subprogram_Descriptors (Corresponding_Spec (N))
1118 -- Set polling off, since we don't need to poll during cleanup
1119 -- actions, and indeed for the cleanup routine, which is executed
1120 -- with aborts deferred, we don't want polling.
1122 Old_Poll := Polling_Required;
1123 Polling_Required := False;
1125 -- Make sure we have a declaration list, since we will add to it
1127 if No (Declarations (N)) then
1128 Set_Declarations (N, New_List);
1131 -- The task activation call has already been built for task
1132 -- allocation blocks.
1134 if not Is_Task_Allocation then
1135 Build_Task_Activation_Call (N);
1139 Establish_Task_Master (N);
1142 -- If secondary stack is in use, expand:
1143 -- _Mxx : constant Mark_Id := SS_Mark;
1145 -- Suppress calls to SS_Mark and SS_Release if VM_Target,
1146 -- since we never use the secondary stack on the VM.
1148 if Uses_Sec_Stack (Current_Scope)
1149 and then not Sec_Stack_Needed_For_Return (Current_Scope)
1150 and then VM_Target = No_VM
1152 Mark := Make_Defining_Identifier (Loc, New_Internal_Name ('M'));
1153 Append_To (New_Decls,
1154 Make_Object_Declaration (Loc,
1155 Defining_Identifier => Mark,
1156 Object_Definition => New_Reference_To (RTE (RE_Mark_Id), Loc),
1158 Make_Function_Call (Loc,
1159 Name => New_Reference_To (RTE (RE_SS_Mark), Loc))));
1161 Set_Uses_Sec_Stack (Current_Scope, False);
1164 -- If finalization list is present then expand:
1165 -- Local_Final_List : System.FI.Finalizable_Ptr;
1167 if Present (Flist) then
1168 Append_To (New_Decls,
1169 Make_Object_Declaration (Loc,
1170 Defining_Identifier => Flist,
1171 Object_Definition =>
1172 New_Reference_To (RTE (RE_Finalizable_Ptr), Loc)));
1175 -- Clean-up procedure definition
1177 Clean := Make_Defining_Identifier (Loc, Name_uClean);
1178 Set_Suppress_Elaboration_Warnings (Clean);
1179 Append_To (New_Decls,
1180 Make_Clean (N, Clean, Mark, Flist,
1185 Is_Asynchronous_Call,
1186 Previous_At_End_Proc));
1188 -- The previous AT END procedure, if any, has been captured in Clean:
1189 -- reset it to Empty now because we check further on that we never
1190 -- overwrite an existing AT END call.
1192 Set_At_End_Proc (Handled_Statement_Sequence (N), Empty);
1194 -- If exception handlers are present, wrap the Sequence of statements in
1195 -- a block because it is not possible to get exception handlers and an
1196 -- AT END call in the same scope.
1198 if Present (Exception_Handlers (Handled_Statement_Sequence (N))) then
1200 -- Preserve end label to provide proper cross-reference information
1202 End_Lab := End_Label (Handled_Statement_Sequence (N));
1204 Make_Block_Statement (Loc,
1205 Handled_Statement_Sequence => Handled_Statement_Sequence (N));
1206 Set_Handled_Statement_Sequence (N,
1207 Make_Handled_Sequence_Of_Statements (Loc, New_List (Blok)));
1208 Set_End_Label (Handled_Statement_Sequence (N), End_Lab);
1211 -- Comment needed here, see RH for 1.306 ???
1213 if Nkind (N) = N_Subprogram_Body then
1214 Set_Has_Nested_Block_With_Handler (Current_Scope);
1217 -- Otherwise we do not wrap
1224 -- Don't move the _chain Activation_Chain declaration in task
1225 -- allocation blocks. Task allocation blocks use this object
1226 -- in their cleanup handlers, and gigi complains if it is declared
1227 -- in the sequence of statements of the scope that declares the
1230 if Is_Task_Allocation then
1231 Chain := Activation_Chain_Entity (N);
1233 Decl := First (Declarations (N));
1234 while Nkind (Decl) /= N_Object_Declaration
1235 or else Defining_Identifier (Decl) /= Chain
1238 pragma Assert (Present (Decl));
1242 Prepend_To (New_Decls, Decl);
1245 -- Now we move the declarations into the Sequence of statements
1246 -- in order to get them protected by the AT END call. It may seem
1247 -- weird to put declarations in the sequence of statement but in
1248 -- fact nothing forbids that at the tree level. We also set the
1249 -- First_Real_Statement field so that we remember where the real
1250 -- statements (i.e. original statements) begin. Note that if we
1251 -- wrapped the statements, the first real statement is inside the
1252 -- inner block. If the First_Real_Statement is already set (as is
1253 -- the case for subprogram bodies that are expansions of task bodies)
1254 -- then do not reset it, because its declarative part would migrate
1255 -- to the statement part.
1258 if No (First_Real_Statement (Handled_Statement_Sequence (N))) then
1259 Set_First_Real_Statement (Handled_Statement_Sequence (N),
1260 First (Statements (Handled_Statement_Sequence (N))));
1264 Set_First_Real_Statement (Handled_Statement_Sequence (N), Blok);
1267 Append_List_To (Declarations (N),
1268 Statements (Handled_Statement_Sequence (N)));
1269 Set_Statements (Handled_Statement_Sequence (N), Declarations (N));
1271 -- We need to reset the Sloc of the handled statement sequence to
1272 -- properly reflect the new initial "statement" in the sequence.
1275 (Handled_Statement_Sequence (N), Sloc (First (Declarations (N))));
1277 -- The declarations of the _Clean procedure and finalization chain
1278 -- replace the old declarations that have been moved inward.
1280 Set_Declarations (N, New_Decls);
1281 Analyze_Declarations (New_Decls);
1283 -- The At_End call is attached to the sequence of statements
1289 -- If the construct is a protected subprogram, then the call to
1290 -- the corresponding unprotected subprogram appears in a block which
1291 -- is the last statement in the body, and it is this block that must
1292 -- be covered by the At_End handler.
1294 if Is_Protected then
1295 HSS := Handled_Statement_Sequence
1296 (Last (Statements (Handled_Statement_Sequence (N))));
1298 HSS := Handled_Statement_Sequence (N);
1301 -- Never overwrite an existing AT END call
1303 pragma Assert (No (At_End_Proc (HSS)));
1305 Set_At_End_Proc (HSS, New_Occurrence_Of (Clean, Loc));
1306 Expand_At_End_Handler (HSS, Empty);
1309 -- Restore saved polling mode
1311 Polling_Required := Old_Poll;
1312 end Expand_Cleanup_Actions;
1314 -------------------------------
1315 -- Expand_Ctrl_Function_Call --
1316 -------------------------------
1318 procedure Expand_Ctrl_Function_Call (N : Node_Id) is
1319 Loc : constant Source_Ptr := Sloc (N);
1320 Rtype : constant Entity_Id := Etype (N);
1321 Utype : constant Entity_Id := Underlying_Type (Rtype);
1324 Action2 : Node_Id := Empty;
1326 Attach_Level : Uint := Uint_1;
1327 Len_Ref : Node_Id := Empty;
1329 function Last_Array_Component
1331 Typ : Entity_Id) return Node_Id;
1332 -- Creates a reference to the last component of the array object
1333 -- designated by Ref whose type is Typ.
1335 --------------------------
1336 -- Last_Array_Component --
1337 --------------------------
1339 function Last_Array_Component
1341 Typ : Entity_Id) return Node_Id
1343 Index_List : constant List_Id := New_List;
1346 for N in 1 .. Number_Dimensions (Typ) loop
1347 Append_To (Index_List,
1348 Make_Attribute_Reference (Loc,
1349 Prefix => Duplicate_Subexpr_No_Checks (Ref),
1350 Attribute_Name => Name_Last,
1351 Expressions => New_List (
1352 Make_Integer_Literal (Loc, N))));
1356 Make_Indexed_Component (Loc,
1357 Prefix => Duplicate_Subexpr (Ref),
1358 Expressions => Index_List);
1359 end Last_Array_Component;
1361 -- Start of processing for Expand_Ctrl_Function_Call
1364 -- Optimization, if the returned value (which is on the sec-stack) is
1365 -- returned again, no need to copy/readjust/finalize, we can just pass
1366 -- the value thru (see Expand_N_Simple_Return_Statement), and thus no
1367 -- attachment is needed
1369 if Nkind (Parent (N)) = N_Simple_Return_Statement then
1373 -- Resolution is now finished, make sure we don't start analysis again
1374 -- because of the duplication
1377 Ref := Duplicate_Subexpr_No_Checks (N);
1379 -- Now we can generate the Attach Call, note that this value is
1380 -- always in the (secondary) stack and thus is attached to a singly
1381 -- linked final list:
1383 -- Resx := F (X)'reference;
1384 -- Attach_To_Final_List (_Lx, Resx.all, 1);
1386 -- or when there are controlled components
1388 -- Attach_To_Final_List (_Lx, Resx._controller, 1);
1390 -- or when it is both is_controlled and has_controlled_components
1392 -- Attach_To_Final_List (_Lx, Resx._controller, 1);
1393 -- Attach_To_Final_List (_Lx, Resx, 1);
1395 -- or if it is an array with is_controlled (and has_controlled)
1397 -- Attach_To_Final_List (_Lx, Resx (Resx'last), 3);
1398 -- An attach level of 3 means that a whole array is to be
1399 -- attached to the finalization list (including the controlled
1402 -- or if it is an array with has_controlled components but not
1405 -- Attach_To_Final_List (_Lx, Resx (Resx'last)._controller, 3);
1407 -- If the context is an aggregate, the call will be expanded into an
1408 -- assignment, and the attachment will be done when the aggregate
1409 -- expansion is complete. See body of Exp_Aggr for the treatment of
1410 -- other controlled components.
1412 if Nkind (Parent (N)) = N_Aggregate then
1416 -- Case where type has controlled components
1418 if Has_Controlled_Component (Rtype) then
1420 T1 : Entity_Id := Rtype;
1421 T2 : Entity_Id := Utype;
1424 if Is_Array_Type (T2) then
1426 Make_Attribute_Reference (Loc,
1428 Duplicate_Subexpr_Move_Checks
1429 (Unchecked_Convert_To (T2, Ref)),
1430 Attribute_Name => Name_Length);
1433 while Is_Array_Type (T2) loop
1435 Ref := Unchecked_Convert_To (T2, Ref);
1438 Ref := Last_Array_Component (Ref, T2);
1439 Attach_Level := Uint_3;
1440 T1 := Component_Type (T2);
1441 T2 := Underlying_Type (T1);
1444 -- If the type has controlled components, go to the controller
1445 -- except in the case of arrays of controlled objects since in
1446 -- this case objects and their components are already chained
1447 -- and the head of the chain is the last array element.
1449 if Is_Array_Type (Rtype) and then Is_Controlled (T2) then
1452 elsif Has_Controlled_Component (T2) then
1454 Ref := Unchecked_Convert_To (T2, Ref);
1458 Make_Selected_Component (Loc,
1460 Selector_Name => Make_Identifier (Loc, Name_uController));
1464 -- Here we know that 'Ref' has a controller so we may as well
1465 -- attach it directly
1470 Flist_Ref => Find_Final_List (Current_Scope),
1471 With_Attach => Make_Integer_Literal (Loc, Attach_Level));
1473 -- If it is also Is_Controlled we need to attach the global object
1475 if Is_Controlled (Rtype) then
1478 Obj_Ref => Duplicate_Subexpr_No_Checks (N),
1479 Flist_Ref => Find_Final_List (Current_Scope),
1480 With_Attach => Make_Integer_Literal (Loc, Attach_Level));
1483 -- Here, we have a controlled type that does not seem to have
1484 -- controlled components but it could be a class wide type whose
1485 -- further derivations have controlled components. So we don't know
1486 -- if the object itself needs to be attached or if it has a record
1487 -- controller. We need to call a runtime function (Deep_Tag_Attach)
1488 -- which knows what to do thanks to the RC_Offset in the dispatch table.
1492 Make_Procedure_Call_Statement (Loc,
1493 Name => New_Reference_To (RTE (RE_Deep_Tag_Attach), Loc),
1494 Parameter_Associations => New_List (
1495 Find_Final_List (Current_Scope),
1497 Make_Attribute_Reference (Loc,
1499 Attribute_Name => Name_Address),
1501 Make_Integer_Literal (Loc, Attach_Level)));
1504 if Present (Len_Ref) then
1506 Make_Implicit_If_Statement (N,
1507 Condition => Make_Op_Gt (Loc,
1508 Left_Opnd => Len_Ref,
1509 Right_Opnd => Make_Integer_Literal (Loc, 0)),
1510 Then_Statements => New_List (Action));
1513 Insert_Action (N, Action);
1514 if Present (Action2) then
1515 Insert_Action (N, Action2);
1517 end Expand_Ctrl_Function_Call;
1519 ---------------------------
1520 -- Expand_N_Package_Body --
1521 ---------------------------
1523 -- Add call to Activate_Tasks if body is an activator (actual processing
1524 -- is in chapter 9).
1526 -- Generate subprogram descriptor for elaboration routine
1528 -- Encode entity names in package body
1530 procedure Expand_N_Package_Body (N : Node_Id) is
1531 Ent : constant Entity_Id := Corresponding_Spec (N);
1534 -- This is done only for non-generic packages
1536 if Ekind (Ent) = E_Package then
1537 Push_Scope (Corresponding_Spec (N));
1539 -- Build dispatch tables of library level tagged types
1541 if Is_Library_Level_Entity (Ent) then
1542 Build_Static_Dispatch_Tables (N);
1545 Build_Task_Activation_Call (N);
1549 Set_Elaboration_Flag (N, Corresponding_Spec (N));
1550 Set_In_Package_Body (Ent, False);
1552 -- Set to encode entity names in package body before gigi is called
1554 Qualify_Entity_Names (N);
1555 end Expand_N_Package_Body;
1557 ----------------------------------
1558 -- Expand_N_Package_Declaration --
1559 ----------------------------------
1561 -- Add call to Activate_Tasks if there are tasks declared and the package
1562 -- has no body. Note that in Ada83, this may result in premature activation
1563 -- of some tasks, given that we cannot tell whether a body will eventually
1566 procedure Expand_N_Package_Declaration (N : Node_Id) is
1567 Spec : constant Node_Id := Specification (N);
1568 Id : constant Entity_Id := Defining_Entity (N);
1570 No_Body : Boolean := False;
1571 -- True in the case of a package declaration that is a compilation unit
1572 -- and for which no associated body will be compiled in
1573 -- this compilation.
1576 -- Case of a package declaration other than a compilation unit
1578 if Nkind (Parent (N)) /= N_Compilation_Unit then
1581 -- Case of a compilation unit that does not require a body
1583 elsif not Body_Required (Parent (N))
1584 and then not Unit_Requires_Body (Id)
1588 -- Special case of generating calling stubs for a remote call interface
1589 -- package: even though the package declaration requires one, the
1590 -- body won't be processed in this compilation (so any stubs for RACWs
1591 -- declared in the package must be generated here, along with the
1594 elsif Parent (N) = Cunit (Main_Unit)
1595 and then Is_Remote_Call_Interface (Id)
1596 and then Distribution_Stub_Mode = Generate_Caller_Stub_Body
1601 -- For a package declaration that implies no associated body, generate
1602 -- task activation call and RACW supporting bodies now (since we won't
1603 -- have a specific separate compilation unit for that).
1608 if Has_RACW (Id) then
1610 -- Generate RACW subprogram bodies
1612 Decls := Private_Declarations (Spec);
1615 Decls := Visible_Declarations (Spec);
1620 Set_Visible_Declarations (Spec, Decls);
1623 Append_RACW_Bodies (Decls, Id);
1624 Analyze_List (Decls);
1627 if Present (Activation_Chain_Entity (N)) then
1629 -- Generate task activation call as last step of elaboration
1631 Build_Task_Activation_Call (N);
1637 -- Build dispatch tables of library level tagged types
1639 if Is_Compilation_Unit (Id)
1640 or else (Is_Generic_Instance (Id)
1641 and then Is_Library_Level_Entity (Id))
1643 Build_Static_Dispatch_Tables (N);
1646 -- Note: it is not necessary to worry about generating a subprogram
1647 -- descriptor, since the only way to get exception handlers into a
1648 -- package spec is to include instantiations, and that would cause
1649 -- generation of subprogram descriptors to be delayed in any case.
1651 -- Set to encode entity names in package spec before gigi is called
1653 Qualify_Entity_Names (N);
1654 end Expand_N_Package_Declaration;
1656 ---------------------
1657 -- Find_Final_List --
1658 ---------------------
1660 function Find_Final_List
1662 Ref : Node_Id := Empty) return Node_Id
1664 Loc : constant Source_Ptr := Sloc (Ref);
1670 -- If the restriction No_Finalization applies, then there's not any
1671 -- finalization list available to return, so return Empty.
1673 if Restriction_Active (No_Finalization) then
1676 -- Case of an internal component. The Final list is the record
1677 -- controller of the enclosing record.
1679 elsif Present (Ref) then
1683 when N_Unchecked_Type_Conversion | N_Type_Conversion =>
1684 R := Expression (R);
1686 when N_Indexed_Component | N_Explicit_Dereference =>
1689 when N_Selected_Component =>
1693 when N_Identifier =>
1697 raise Program_Error;
1702 Make_Selected_Component (Loc,
1704 Make_Selected_Component (Loc,
1706 Selector_Name => Make_Identifier (Loc, Name_uController)),
1707 Selector_Name => Make_Identifier (Loc, Name_F));
1709 -- Case of a dynamically allocated object whose access type has an
1710 -- Associated_Final_Chain. The final list is the corresponding list
1711 -- controller (the next entity in the scope of the access type with
1712 -- the right type). If the type comes from a With_Type clause, no
1713 -- controller was created, we use the global chain instead. (The code
1714 -- related to with_type clauses should presumably be removed at some
1715 -- point since that feature is obsolete???)
1717 -- An anonymous access type either has a list created for it when the
1718 -- allocator is a for an access parameter or an access discriminant,
1719 -- or else it uses the list of the enclosing dynamic scope, when the
1720 -- context is a declaration or an assignment.
1722 elsif Is_Access_Type (E)
1723 and then (Present (Associated_Final_Chain (E))
1724 or else From_With_Type (E))
1726 if From_With_Type (E) then
1727 return New_Reference_To (RTE (RE_Global_Final_List), Sloc (E));
1729 -- Use the access type's associated finalization chain
1733 Make_Selected_Component (Loc,
1736 (Associated_Final_Chain (Base_Type (E)), Loc),
1737 Selector_Name => Make_Identifier (Loc, Name_F));
1741 if Is_Dynamic_Scope (E) then
1744 S := Enclosing_Dynamic_Scope (E);
1747 -- When the finalization chain entity is 'Error', it means that there
1748 -- should not be any chain at that level and that the enclosing one
1751 -- This is a nasty kludge, see ??? note in exp_ch11
1753 while Finalization_Chain_Entity (S) = Error loop
1754 S := Enclosing_Dynamic_Scope (S);
1757 if S = Standard_Standard then
1758 return New_Reference_To (RTE (RE_Global_Final_List), Sloc (E));
1760 if No (Finalization_Chain_Entity (S)) then
1762 -- In the case where the scope is a subprogram, retrieve the
1763 -- Sloc of subprogram's body for association with the chain,
1764 -- since using the Sloc of the spec would be confusing during
1765 -- source-line stepping within the debugger.
1768 Flist_Loc : Source_Ptr := Sloc (S);
1769 Subp_Body : Node_Id;
1772 if Ekind (S) in Subprogram_Kind then
1773 Subp_Body := Unit_Declaration_Node (S);
1775 if Nkind (Subp_Body) /= N_Subprogram_Body then
1776 Subp_Body := Corresponding_Body (Subp_Body);
1779 if Present (Subp_Body) then
1780 Flist_Loc := Sloc (Subp_Body);
1785 Make_Defining_Identifier (Flist_Loc,
1786 Chars => New_Internal_Name ('F'));
1789 Set_Finalization_Chain_Entity (S, Id);
1791 -- Set momentarily some semantics attributes to allow normal
1792 -- analysis of expansions containing references to this chain.
1793 -- Will be fully decorated during the expansion of the scope
1796 Set_Ekind (Id, E_Variable);
1797 Set_Etype (Id, RTE (RE_Finalizable_Ptr));
1800 return New_Reference_To (Finalization_Chain_Entity (S), Sloc (E));
1803 end Find_Final_List;
1805 -----------------------------
1806 -- Find_Node_To_Be_Wrapped --
1807 -----------------------------
1809 function Find_Node_To_Be_Wrapped (N : Node_Id) return Node_Id is
1811 The_Parent : Node_Id;
1817 pragma Assert (P /= Empty);
1818 The_Parent := Parent (P);
1820 case Nkind (The_Parent) is
1822 -- Simple statement can be wrapped
1827 -- Usually assignments are good candidate for wrapping
1828 -- except when they have been generated as part of a
1829 -- controlled aggregate where the wrapping should take
1830 -- place more globally.
1832 when N_Assignment_Statement =>
1833 if No_Ctrl_Actions (The_Parent) then
1839 -- An entry call statement is a special case if it occurs in
1840 -- the context of a Timed_Entry_Call. In this case we wrap
1841 -- the entire timed entry call.
1843 when N_Entry_Call_Statement |
1844 N_Procedure_Call_Statement =>
1845 if Nkind (Parent (The_Parent)) = N_Entry_Call_Alternative
1846 and then Nkind_In (Parent (Parent (The_Parent)),
1848 N_Conditional_Entry_Call)
1850 return Parent (Parent (The_Parent));
1855 -- Object declarations are also a boundary for the transient scope
1856 -- even if they are not really wrapped
1857 -- (see Wrap_Transient_Declaration)
1859 when N_Object_Declaration |
1860 N_Object_Renaming_Declaration |
1861 N_Subtype_Declaration =>
1864 -- The expression itself is to be wrapped if its parent is a
1865 -- compound statement or any other statement where the expression
1866 -- is known to be scalar
1868 when N_Accept_Alternative |
1869 N_Attribute_Definition_Clause |
1872 N_Delay_Alternative |
1873 N_Delay_Until_Statement |
1874 N_Delay_Relative_Statement |
1875 N_Discriminant_Association |
1877 N_Entry_Body_Formal_Part |
1880 N_Iteration_Scheme |
1881 N_Terminate_Alternative =>
1884 when N_Attribute_Reference =>
1886 if Is_Procedure_Attribute_Name
1887 (Attribute_Name (The_Parent))
1892 -- A raise statement can be wrapped. This will arise when the
1893 -- expression in a raise_with_expression uses the secondary
1894 -- stack, for example.
1896 when N_Raise_Statement =>
1899 -- If the expression is within the iteration scheme of a loop,
1900 -- we must create a declaration for it, followed by an assignment
1901 -- in order to have a usable statement to wrap.
1903 when N_Loop_Parameter_Specification =>
1904 return Parent (The_Parent);
1906 -- The following nodes contains "dummy calls" which don't
1907 -- need to be wrapped.
1909 when N_Parameter_Specification |
1910 N_Discriminant_Specification |
1911 N_Component_Declaration =>
1914 -- The return statement is not to be wrapped when the function
1915 -- itself needs wrapping at the outer-level
1917 when N_Simple_Return_Statement =>
1919 Applies_To : constant Entity_Id :=
1921 (Return_Statement_Entity (The_Parent));
1922 Return_Type : constant Entity_Id := Etype (Applies_To);
1924 if Requires_Transient_Scope (Return_Type) then
1931 -- If we leave a scope without having been able to find a node to
1932 -- wrap, something is going wrong but this can happen in error
1933 -- situation that are not detected yet (such as a dynamic string
1934 -- in a pragma export)
1936 when N_Subprogram_Body |
1937 N_Package_Declaration |
1939 N_Block_Statement =>
1942 -- otherwise continue the search
1948 end Find_Node_To_Be_Wrapped;
1950 ----------------------
1951 -- Global_Flist_Ref --
1952 ----------------------
1954 function Global_Flist_Ref (Flist_Ref : Node_Id) return Boolean is
1958 -- Look for the Global_Final_List
1960 if Is_Entity_Name (Flist_Ref) then
1961 Flist := Entity (Flist_Ref);
1963 -- Look for the final list associated with an access to controlled
1965 elsif Nkind (Flist_Ref) = N_Selected_Component
1966 and then Is_Entity_Name (Prefix (Flist_Ref))
1968 Flist := Entity (Prefix (Flist_Ref));
1973 return Present (Flist)
1974 and then Present (Scope (Flist))
1975 and then Enclosing_Dynamic_Scope (Flist) = Standard_Standard;
1976 end Global_Flist_Ref;
1978 ----------------------------------
1979 -- Has_New_Controlled_Component --
1980 ----------------------------------
1982 function Has_New_Controlled_Component (E : Entity_Id) return Boolean is
1986 if not Is_Tagged_Type (E) then
1987 return Has_Controlled_Component (E);
1988 elsif not Is_Derived_Type (E) then
1989 return Has_Controlled_Component (E);
1992 Comp := First_Component (E);
1993 while Present (Comp) loop
1995 if Chars (Comp) = Name_uParent then
1998 elsif Scope (Original_Record_Component (Comp)) = E
1999 and then Needs_Finalization (Etype (Comp))
2004 Next_Component (Comp);
2008 end Has_New_Controlled_Component;
2010 --------------------------
2011 -- In_Finalization_Root --
2012 --------------------------
2014 -- It would seem simpler to test Scope (RTE (RE_Root_Controlled)) but
2015 -- the purpose of this function is to avoid a circular call to Rtsfind
2016 -- which would been caused by such a test.
2018 function In_Finalization_Root (E : Entity_Id) return Boolean is
2019 S : constant Entity_Id := Scope (E);
2022 return Chars (Scope (S)) = Name_System
2023 and then Chars (S) = Name_Finalization_Root
2024 and then Scope (Scope (S)) = Standard_Standard;
2025 end In_Finalization_Root;
2027 ------------------------------------
2028 -- Insert_Actions_In_Scope_Around --
2029 ------------------------------------
2031 procedure Insert_Actions_In_Scope_Around (N : Node_Id) is
2032 SE : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
2036 -- If the node to be wrapped is the triggering statement of an
2037 -- asynchronous select, it is not part of a statement list. The
2038 -- actions must be inserted before the Select itself, which is
2039 -- part of some list of statements. Note that the triggering
2040 -- alternative includes the triggering statement and an optional
2041 -- statement list. If the node to be wrapped is part of that list,
2042 -- the normal insertion applies.
2044 if Nkind (Parent (Node_To_Be_Wrapped)) = N_Triggering_Alternative
2045 and then not Is_List_Member (Node_To_Be_Wrapped)
2047 Target := Parent (Parent (Node_To_Be_Wrapped));
2052 if Present (SE.Actions_To_Be_Wrapped_Before) then
2053 Insert_List_Before (Target, SE.Actions_To_Be_Wrapped_Before);
2054 SE.Actions_To_Be_Wrapped_Before := No_List;
2057 if Present (SE.Actions_To_Be_Wrapped_After) then
2058 Insert_List_After (Target, SE.Actions_To_Be_Wrapped_After);
2059 SE.Actions_To_Be_Wrapped_After := No_List;
2061 end Insert_Actions_In_Scope_Around;
2063 -----------------------
2064 -- Make_Adjust_Call --
2065 -----------------------
2067 function Make_Adjust_Call
2070 Flist_Ref : Node_Id;
2071 With_Attach : Node_Id;
2072 Allocator : Boolean := False) return List_Id
2074 Loc : constant Source_Ptr := Sloc (Ref);
2075 Res : constant List_Id := New_List;
2078 Cref : Node_Id := Ref;
2080 Attach : Node_Id := With_Attach;
2083 if Is_Class_Wide_Type (Typ) then
2084 Utyp := Underlying_Type (Base_Type (Root_Type (Typ)));
2086 Utyp := Underlying_Type (Base_Type (Typ));
2089 Set_Assignment_OK (Cref);
2091 -- Deal with non-tagged derivation of private views
2093 if Is_Untagged_Derivation (Typ) then
2094 Utyp := Underlying_Type (Root_Type (Base_Type (Typ)));
2095 Cref := Unchecked_Convert_To (Utyp, Cref);
2096 Set_Assignment_OK (Cref);
2097 -- To prevent problems with UC see 1.156 RH ???
2100 -- If the underlying_type is a subtype, we are dealing with
2101 -- the completion of a private type. We need to access
2102 -- the base type and generate a conversion to it.
2104 if Utyp /= Base_Type (Utyp) then
2105 pragma Assert (Is_Private_Type (Typ));
2106 Utyp := Base_Type (Utyp);
2107 Cref := Unchecked_Convert_To (Utyp, Cref);
2110 -- If the object is unanalyzed, set its expected type for use
2111 -- in Convert_View in case an additional conversion is needed.
2113 if No (Etype (Cref))
2114 and then Nkind (Cref) /= N_Unchecked_Type_Conversion
2116 Set_Etype (Cref, Typ);
2119 -- We do not need to attach to one of the Global Final Lists
2120 -- the objects whose type is Finalize_Storage_Only
2122 if Finalize_Storage_Only (Typ)
2123 and then (Global_Flist_Ref (Flist_Ref)
2124 or else Entity (Constant_Value (RTE (RE_Garbage_Collected)))
2127 Attach := Make_Integer_Literal (Loc, 0);
2130 -- Special case for allocators: need initialization of the chain
2131 -- pointers. For the 0 case, reset them to null.
2134 pragma Assert (Nkind (Attach) = N_Integer_Literal);
2136 if Intval (Attach) = 0 then
2137 Set_Intval (Attach, Uint_4);
2142 -- Deep_Adjust (Flist_Ref, Ref, Attach);
2144 if Has_Controlled_Component (Utyp)
2145 or else Is_Class_Wide_Type (Typ)
2147 if Is_Tagged_Type (Utyp) then
2148 Proc := Find_Prim_Op (Utyp, TSS_Deep_Adjust);
2151 Proc := TSS (Utyp, TSS_Deep_Adjust);
2154 Cref := Convert_View (Proc, Cref, 2);
2157 Make_Procedure_Call_Statement (Loc,
2158 Name => New_Reference_To (Proc, Loc),
2159 Parameter_Associations =>
2160 New_List (Flist_Ref, Cref, Attach)));
2163 -- if With_Attach then
2164 -- Attach_To_Final_List (Ref, Flist_Ref);
2168 else -- Is_Controlled (Utyp)
2170 Proc := Find_Prim_Op (Utyp, Name_Of (Adjust_Case));
2171 Cref := Convert_View (Proc, Cref);
2172 Cref2 := New_Copy_Tree (Cref);
2175 Make_Procedure_Call_Statement (Loc,
2176 Name => New_Reference_To (Proc, Loc),
2177 Parameter_Associations => New_List (Cref2)));
2179 Append_To (Res, Make_Attach_Call (Cref, Flist_Ref, Attach));
2183 end Make_Adjust_Call;
2185 ----------------------
2186 -- Make_Attach_Call --
2187 ----------------------
2190 -- System.FI.Attach_To_Final_List (Flist, Ref, Nb_Link)
2192 function Make_Attach_Call
2194 Flist_Ref : Node_Id;
2195 With_Attach : Node_Id) return Node_Id
2197 Loc : constant Source_Ptr := Sloc (Obj_Ref);
2200 -- Optimization: If the number of links is statically '0', don't
2201 -- call the attach_proc.
2203 if Nkind (With_Attach) = N_Integer_Literal
2204 and then Intval (With_Attach) = Uint_0
2206 return Make_Null_Statement (Loc);
2210 Make_Procedure_Call_Statement (Loc,
2211 Name => New_Reference_To (RTE (RE_Attach_To_Final_List), Loc),
2212 Parameter_Associations => New_List (
2214 OK_Convert_To (RTE (RE_Finalizable), Obj_Ref),
2216 end Make_Attach_Call;
2228 Is_Master : Boolean;
2229 Is_Protected_Subprogram : Boolean;
2230 Is_Task_Allocation_Block : Boolean;
2231 Is_Asynchronous_Call_Block : Boolean;
2232 Chained_Cleanup_Action : Node_Id) return Node_Id
2234 Loc : constant Source_Ptr := Sloc (Clean);
2235 Stmt : constant List_Id := New_List;
2241 Param_Type : Entity_Id;
2242 Pid : Entity_Id := Empty;
2243 Cancel_Param : Entity_Id;
2247 if Restricted_Profile then
2249 (Stmt, Build_Runtime_Call (Loc, RE_Complete_Restricted_Task));
2251 Append_To (Stmt, Build_Runtime_Call (Loc, RE_Complete_Task));
2254 elsif Is_Master then
2255 if Restriction_Active (No_Task_Hierarchy) = False then
2256 Append_To (Stmt, Build_Runtime_Call (Loc, RE_Complete_Master));
2259 elsif Is_Protected_Subprogram then
2261 -- Add statements to the cleanup handler of the (ordinary)
2262 -- subprogram expanded to implement a protected subprogram,
2263 -- unlocking the protected object parameter and undeferring abort.
2264 -- If this is a protected procedure, and the object contains
2265 -- entries, this also calls the entry service routine.
2267 -- NOTE: This cleanup handler references _object, a parameter
2268 -- to the procedure.
2270 -- Find the _object parameter representing the protected object
2272 Spec := Parent (Corresponding_Spec (N));
2274 Param := First (Parameter_Specifications (Spec));
2276 Param_Type := Etype (Parameter_Type (Param));
2278 if Ekind (Param_Type) = E_Record_Type then
2279 Pid := Corresponding_Concurrent_Type (Param_Type);
2282 exit when No (Param) or else Present (Pid);
2286 pragma Assert (Present (Param));
2288 -- If the associated protected object declares entries,
2289 -- a protected procedure has to service entry queues.
2290 -- In this case, add
2292 -- Service_Entries (_object._object'Access);
2294 -- _object is the record used to implement the protected object.
2295 -- It is a parameter to the protected subprogram.
2297 if Nkind (Specification (N)) = N_Procedure_Specification
2298 and then Has_Entries (Pid)
2300 case Corresponding_Runtime_Package (Pid) is
2301 when System_Tasking_Protected_Objects_Entries =>
2302 Name := New_Reference_To (RTE (RE_Service_Entries), Loc);
2304 when System_Tasking_Protected_Objects_Single_Entry =>
2305 Name := New_Reference_To (RTE (RE_Service_Entry), Loc);
2308 raise Program_Error;
2312 Make_Procedure_Call_Statement (Loc,
2314 Parameter_Associations => New_List (
2315 Make_Attribute_Reference (Loc,
2317 Make_Selected_Component (Loc,
2318 Prefix => New_Reference_To (
2319 Defining_Identifier (Param), Loc),
2321 Make_Identifier (Loc, Name_uObject)),
2322 Attribute_Name => Name_Unchecked_Access))));
2325 -- Unlock (_object._object'Access);
2327 -- object is the record used to implement the protected object.
2328 -- It is a parameter to the protected subprogram.
2330 case Corresponding_Runtime_Package (Pid) is
2331 when System_Tasking_Protected_Objects_Entries =>
2332 Name := New_Reference_To (RTE (RE_Unlock_Entries), Loc);
2334 when System_Tasking_Protected_Objects_Single_Entry =>
2335 Name := New_Reference_To (RTE (RE_Unlock_Entry), Loc);
2337 when System_Tasking_Protected_Objects =>
2338 Name := New_Reference_To (RTE (RE_Unlock), Loc);
2341 raise Program_Error;
2345 Make_Procedure_Call_Statement (Loc,
2347 Parameter_Associations => New_List (
2348 Make_Attribute_Reference (Loc,
2350 Make_Selected_Component (Loc,
2352 New_Reference_To (Defining_Identifier (Param), Loc),
2354 Make_Identifier (Loc, Name_uObject)),
2355 Attribute_Name => Name_Unchecked_Access))));
2358 if Abort_Allowed then
2363 Make_Procedure_Call_Statement (Loc,
2366 RTE (RE_Abort_Undefer), Loc),
2367 Parameter_Associations => Empty_List));
2370 elsif Is_Task_Allocation_Block then
2372 -- Add a call to Expunge_Unactivated_Tasks to the cleanup
2373 -- handler of a block created for the dynamic allocation of
2376 -- Expunge_Unactivated_Tasks (_chain);
2378 -- where _chain is the list of tasks created by the allocator
2379 -- but not yet activated. This list will be empty unless
2380 -- the block completes abnormally.
2382 -- This only applies to dynamically allocated tasks;
2383 -- other unactivated tasks are completed by Complete_Task or
2386 -- NOTE: This cleanup handler references _chain, a local
2390 Make_Procedure_Call_Statement (Loc,
2393 RTE (RE_Expunge_Unactivated_Tasks), Loc),
2394 Parameter_Associations => New_List (
2395 New_Reference_To (Activation_Chain_Entity (N), Loc))));
2397 elsif Is_Asynchronous_Call_Block then
2399 -- Add a call to attempt to cancel the asynchronous entry call
2400 -- whenever the block containing the abortable part is exited.
2402 -- NOTE: This cleanup handler references C, a local object
2404 -- Get the argument to the Cancel procedure
2405 Cancel_Param := Entry_Cancel_Parameter (Entity (Identifier (N)));
2407 -- If it is of type Communication_Block, this must be a
2408 -- protected entry call.
2410 if Is_RTE (Etype (Cancel_Param), RE_Communication_Block) then
2414 -- if Enqueued (Cancel_Parameter) then
2416 Make_Implicit_If_Statement (Clean,
2417 Condition => Make_Function_Call (Loc,
2418 Name => New_Reference_To (
2419 RTE (RE_Enqueued), Loc),
2420 Parameter_Associations => New_List (
2421 New_Reference_To (Cancel_Param, Loc))),
2422 Then_Statements => New_List (
2424 -- Cancel_Protected_Entry_Call (Cancel_Param);
2426 Make_Procedure_Call_Statement (Loc,
2427 Name => New_Reference_To (
2428 RTE (RE_Cancel_Protected_Entry_Call), Loc),
2429 Parameter_Associations => New_List (
2430 New_Reference_To (Cancel_Param, Loc))))));
2432 -- Asynchronous delay
2434 elsif Is_RTE (Etype (Cancel_Param), RE_Delay_Block) then
2436 Make_Procedure_Call_Statement (Loc,
2437 Name => New_Reference_To (RTE (RE_Cancel_Async_Delay), Loc),
2438 Parameter_Associations => New_List (
2439 Make_Attribute_Reference (Loc,
2440 Prefix => New_Reference_To (Cancel_Param, Loc),
2441 Attribute_Name => Name_Unchecked_Access))));
2446 -- Append call to Cancel_Task_Entry_Call (C);
2449 Make_Procedure_Call_Statement (Loc,
2450 Name => New_Reference_To (
2451 RTE (RE_Cancel_Task_Entry_Call),
2453 Parameter_Associations => New_List (
2454 New_Reference_To (Cancel_Param, Loc))));
2459 if Present (Flist) then
2461 Make_Procedure_Call_Statement (Loc,
2462 Name => New_Reference_To (RTE (RE_Finalize_List), Loc),
2463 Parameter_Associations => New_List (
2464 New_Reference_To (Flist, Loc))));
2467 if Present (Mark) then
2469 Make_Procedure_Call_Statement (Loc,
2470 Name => New_Reference_To (RTE (RE_SS_Release), Loc),
2471 Parameter_Associations => New_List (
2472 New_Reference_To (Mark, Loc))));
2475 if Present (Chained_Cleanup_Action) then
2477 Make_Procedure_Call_Statement (Loc,
2478 Name => Chained_Cleanup_Action));
2482 Make_Subprogram_Body (Loc,
2484 Make_Procedure_Specification (Loc,
2485 Defining_Unit_Name => Clean),
2487 Declarations => New_List,
2489 Handled_Statement_Sequence =>
2490 Make_Handled_Sequence_Of_Statements (Loc,
2491 Statements => Stmt));
2493 if Present (Flist) or else Is_Task or else Is_Master then
2494 Wrap_Cleanup_Procedure (Sbody);
2497 -- We do not want debug information for _Clean routines,
2498 -- since it just confuses the debugging operation unless
2499 -- we are debugging generated code.
2501 if not Debug_Generated_Code then
2502 Set_Debug_Info_Off (Clean, True);
2508 --------------------------
2509 -- Make_Deep_Array_Body --
2510 --------------------------
2512 -- Array components are initialized and adjusted in the normal order
2513 -- and finalized in the reverse order. Exceptions are handled and
2514 -- Program_Error is re-raise in the Adjust and Finalize case
2515 -- (RM 7.6.1(12)). Generate the following code :
2517 -- procedure Deep_<P> -- with <P> being Initialize or Adjust or Finalize
2518 -- (L : in out Finalizable_Ptr;
2522 -- for J1 in Typ'First (1) .. Typ'Last (1) loop
2523 -- ^ reverse ^ -- in the finalization case
2525 -- for J2 in Typ'First (n) .. Typ'Last (n) loop
2526 -- Make_<P>_Call (Typ, V (J1, .. , Jn), L, V);
2530 -- exception -- not in the
2531 -- when others => raise Program_Error; -- Initialize case
2534 function Make_Deep_Array_Body
2535 (Prim : Final_Primitives;
2536 Typ : Entity_Id) return List_Id
2538 Loc : constant Source_Ptr := Sloc (Typ);
2540 Index_List : constant List_Id := New_List;
2541 -- Stores the list of references to the indexes (one per dimension)
2543 function One_Component return List_Id;
2544 -- Create one statement to initialize/adjust/finalize one array
2545 -- component, designated by a full set of indices.
2547 function One_Dimension (N : Int) return List_Id;
2548 -- Create loop to deal with one dimension of the array. The single
2549 -- statement in the body of the loop initializes the inner dimensions if
2550 -- any, or else a single component.
2556 function One_Component return List_Id is
2557 Comp_Typ : constant Entity_Id := Component_Type (Typ);
2558 Comp_Ref : constant Node_Id :=
2559 Make_Indexed_Component (Loc,
2560 Prefix => Make_Identifier (Loc, Name_V),
2561 Expressions => Index_List);
2564 -- Set the etype of the component Reference, which is used to
2565 -- determine whether a conversion to a parent type is needed.
2567 Set_Etype (Comp_Ref, Comp_Typ);
2570 when Initialize_Case =>
2571 return Make_Init_Call (Comp_Ref, Comp_Typ,
2572 Make_Identifier (Loc, Name_L),
2573 Make_Identifier (Loc, Name_B));
2576 return Make_Adjust_Call (Comp_Ref, Comp_Typ,
2577 Make_Identifier (Loc, Name_L),
2578 Make_Identifier (Loc, Name_B));
2580 when Finalize_Case =>
2581 return Make_Final_Call (Comp_Ref, Comp_Typ,
2582 Make_Identifier (Loc, Name_B));
2590 function One_Dimension (N : Int) return List_Id is
2594 if N > Number_Dimensions (Typ) then
2595 return One_Component;
2599 Make_Defining_Identifier (Loc, New_External_Name ('J', N));
2601 Append_To (Index_List, New_Reference_To (Index, Loc));
2604 Make_Implicit_Loop_Statement (Typ,
2605 Identifier => Empty,
2607 Make_Iteration_Scheme (Loc,
2608 Loop_Parameter_Specification =>
2609 Make_Loop_Parameter_Specification (Loc,
2610 Defining_Identifier => Index,
2611 Discrete_Subtype_Definition =>
2612 Make_Attribute_Reference (Loc,
2613 Prefix => Make_Identifier (Loc, Name_V),
2614 Attribute_Name => Name_Range,
2615 Expressions => New_List (
2616 Make_Integer_Literal (Loc, N))),
2617 Reverse_Present => Prim = Finalize_Case)),
2618 Statements => One_Dimension (N + 1)));
2622 -- Start of processing for Make_Deep_Array_Body
2625 return One_Dimension (1);
2626 end Make_Deep_Array_Body;
2628 --------------------
2629 -- Make_Deep_Proc --
2630 --------------------
2633 -- procedure DEEP_<prim>
2634 -- (L : IN OUT Finalizable_Ptr; -- not for Finalize
2635 -- V : IN OUT <typ>;
2636 -- B : IN Short_Short_Integer) is
2639 -- exception -- Finalize and Adjust Cases only
2640 -- raise Program_Error; -- idem
2643 function Make_Deep_Proc
2644 (Prim : Final_Primitives;
2646 Stmts : List_Id) return Entity_Id
2648 Loc : constant Source_Ptr := Sloc (Typ);
2650 Proc_Name : Entity_Id;
2651 Handler : List_Id := No_List;
2655 if Prim = Finalize_Case then
2656 Formals := New_List;
2657 Type_B := Standard_Boolean;
2660 Formals := New_List (
2661 Make_Parameter_Specification (Loc,
2662 Defining_Identifier => Make_Defining_Identifier (Loc, Name_L),
2664 Out_Present => True,
2666 New_Reference_To (RTE (RE_Finalizable_Ptr), Loc)));
2667 Type_B := Standard_Short_Short_Integer;
2671 Make_Parameter_Specification (Loc,
2672 Defining_Identifier => Make_Defining_Identifier (Loc, Name_V),
2674 Out_Present => True,
2675 Parameter_Type => New_Reference_To (Typ, Loc)));
2678 Make_Parameter_Specification (Loc,
2679 Defining_Identifier => Make_Defining_Identifier (Loc, Name_B),
2680 Parameter_Type => New_Reference_To (Type_B, Loc)));
2682 if Prim = Finalize_Case or else Prim = Adjust_Case then
2683 Handler := New_List (Make_Handler_For_Ctrl_Operation (Loc));
2687 Make_Defining_Identifier (Loc,
2688 Chars => Make_TSS_Name (Typ, Deep_Name_Of (Prim)));
2691 Make_Subprogram_Body (Loc,
2693 Make_Procedure_Specification (Loc,
2694 Defining_Unit_Name => Proc_Name,
2695 Parameter_Specifications => Formals),
2697 Declarations => Empty_List,
2698 Handled_Statement_Sequence =>
2699 Make_Handled_Sequence_Of_Statements (Loc,
2700 Statements => Stmts,
2701 Exception_Handlers => Handler)));
2706 ---------------------------
2707 -- Make_Deep_Record_Body --
2708 ---------------------------
2710 -- The Deep procedures call the appropriate Controlling proc on the
2711 -- the controller component. In the init case, it also attach the
2712 -- controller to the current finalization list.
2714 function Make_Deep_Record_Body
2715 (Prim : Final_Primitives;
2716 Typ : Entity_Id) return List_Id
2718 Loc : constant Source_Ptr := Sloc (Typ);
2719 Controller_Typ : Entity_Id;
2720 Obj_Ref : constant Node_Id := Make_Identifier (Loc, Name_V);
2721 Controller_Ref : constant Node_Id :=
2722 Make_Selected_Component (Loc,
2725 Make_Identifier (Loc, Name_uController));
2726 Res : constant List_Id := New_List;
2729 if Is_Inherently_Limited_Type (Typ) then
2730 Controller_Typ := RTE (RE_Limited_Record_Controller);
2732 Controller_Typ := RTE (RE_Record_Controller);
2736 when Initialize_Case =>
2737 Append_List_To (Res,
2739 Ref => Controller_Ref,
2740 Typ => Controller_Typ,
2741 Flist_Ref => Make_Identifier (Loc, Name_L),
2742 With_Attach => Make_Identifier (Loc, Name_B)));
2744 -- When the type is also a controlled type by itself,
2745 -- initialize it and attach it to the finalization chain.
2747 if Is_Controlled (Typ) then
2749 Make_Procedure_Call_Statement (Loc,
2750 Name => New_Reference_To (
2751 Find_Prim_Op (Typ, Name_Of (Prim)), Loc),
2752 Parameter_Associations =>
2753 New_List (New_Copy_Tree (Obj_Ref))));
2755 Append_To (Res, Make_Attach_Call (
2756 Obj_Ref => New_Copy_Tree (Obj_Ref),
2757 Flist_Ref => Make_Identifier (Loc, Name_L),
2758 With_Attach => Make_Identifier (Loc, Name_B)));
2762 Append_List_To (Res,
2763 Make_Adjust_Call (Controller_Ref, Controller_Typ,
2764 Make_Identifier (Loc, Name_L),
2765 Make_Identifier (Loc, Name_B)));
2767 -- When the type is also a controlled type by itself,
2768 -- adjust it and attach it to the finalization chain.
2770 if Is_Controlled (Typ) then
2772 Make_Procedure_Call_Statement (Loc,
2773 Name => New_Reference_To (
2774 Find_Prim_Op (Typ, Name_Of (Prim)), Loc),
2775 Parameter_Associations =>
2776 New_List (New_Copy_Tree (Obj_Ref))));
2778 Append_To (Res, Make_Attach_Call (
2779 Obj_Ref => New_Copy_Tree (Obj_Ref),
2780 Flist_Ref => Make_Identifier (Loc, Name_L),
2781 With_Attach => Make_Identifier (Loc, Name_B)));
2784 when Finalize_Case =>
2785 if Is_Controlled (Typ) then
2787 Make_Implicit_If_Statement (Obj_Ref,
2788 Condition => Make_Identifier (Loc, Name_B),
2789 Then_Statements => New_List (
2790 Make_Procedure_Call_Statement (Loc,
2791 Name => New_Reference_To (RTE (RE_Finalize_One), Loc),
2792 Parameter_Associations => New_List (
2793 OK_Convert_To (RTE (RE_Finalizable),
2794 New_Copy_Tree (Obj_Ref))))),
2796 Else_Statements => New_List (
2797 Make_Procedure_Call_Statement (Loc,
2798 Name => New_Reference_To (
2799 Find_Prim_Op (Typ, Name_Of (Prim)), Loc),
2800 Parameter_Associations =>
2801 New_List (New_Copy_Tree (Obj_Ref))))));
2804 Append_List_To (Res,
2805 Make_Final_Call (Controller_Ref, Controller_Typ,
2806 Make_Identifier (Loc, Name_B)));
2809 end Make_Deep_Record_Body;
2811 ----------------------
2812 -- Make_Final_Call --
2813 ----------------------
2815 function Make_Final_Call
2818 With_Detach : Node_Id) return List_Id
2820 Loc : constant Source_Ptr := Sloc (Ref);
2821 Res : constant List_Id := New_List;
2828 if Is_Class_Wide_Type (Typ) then
2829 Utyp := Root_Type (Typ);
2832 elsif Is_Concurrent_Type (Typ) then
2833 Utyp := Corresponding_Record_Type (Typ);
2834 Cref := Convert_Concurrent (Ref, Typ);
2836 elsif Is_Private_Type (Typ)
2837 and then Present (Full_View (Typ))
2838 and then Is_Concurrent_Type (Full_View (Typ))
2840 Utyp := Corresponding_Record_Type (Full_View (Typ));
2841 Cref := Convert_Concurrent (Ref, Full_View (Typ));
2847 Utyp := Underlying_Type (Base_Type (Utyp));
2848 Set_Assignment_OK (Cref);
2850 -- Deal with non-tagged derivation of private views. If the parent is
2851 -- now known to be protected, the finalization routine is the one
2852 -- defined on the corresponding record of the ancestor (corresponding
2853 -- records do not automatically inherit operations, but maybe they
2856 if Is_Untagged_Derivation (Typ) then
2857 if Is_Protected_Type (Typ) then
2858 Utyp := Corresponding_Record_Type (Root_Type (Base_Type (Typ)));
2860 Utyp := Underlying_Type (Root_Type (Base_Type (Typ)));
2863 Cref := Unchecked_Convert_To (Utyp, Cref);
2865 -- We need to set Assignment_OK to prevent problems with unchecked
2866 -- conversions, where we do not want them to be converted back in the
2867 -- case of untagged record derivation (see code in Make_*_Call
2868 -- procedures for similar situations).
2870 Set_Assignment_OK (Cref);
2873 -- If the underlying_type is a subtype, we are dealing with
2874 -- the completion of a private type. We need to access
2875 -- the base type and generate a conversion to it.
2877 if Utyp /= Base_Type (Utyp) then
2878 pragma Assert (Is_Private_Type (Typ));
2879 Utyp := Base_Type (Utyp);
2880 Cref := Unchecked_Convert_To (Utyp, Cref);
2884 -- Deep_Finalize (Ref, With_Detach);
2886 if Has_Controlled_Component (Utyp)
2887 or else Is_Class_Wide_Type (Typ)
2889 if Is_Tagged_Type (Utyp) then
2890 Proc := Find_Prim_Op (Utyp, TSS_Deep_Finalize);
2892 Proc := TSS (Utyp, TSS_Deep_Finalize);
2895 Cref := Convert_View (Proc, Cref);
2898 Make_Procedure_Call_Statement (Loc,
2899 Name => New_Reference_To (Proc, Loc),
2900 Parameter_Associations =>
2901 New_List (Cref, With_Detach)));
2904 -- if With_Detach then
2905 -- Finalize_One (Ref);
2911 Proc := Find_Prim_Op (Utyp, Name_Of (Finalize_Case));
2913 if Chars (With_Detach) = Chars (Standard_True) then
2915 Make_Procedure_Call_Statement (Loc,
2916 Name => New_Reference_To (RTE (RE_Finalize_One), Loc),
2917 Parameter_Associations => New_List (
2918 OK_Convert_To (RTE (RE_Finalizable), Cref))));
2920 elsif Chars (With_Detach) = Chars (Standard_False) then
2922 Make_Procedure_Call_Statement (Loc,
2923 Name => New_Reference_To (Proc, Loc),
2924 Parameter_Associations =>
2925 New_List (Convert_View (Proc, Cref))));
2928 Cref2 := New_Copy_Tree (Cref);
2930 Make_Implicit_If_Statement (Ref,
2931 Condition => With_Detach,
2932 Then_Statements => New_List (
2933 Make_Procedure_Call_Statement (Loc,
2934 Name => New_Reference_To (RTE (RE_Finalize_One), Loc),
2935 Parameter_Associations => New_List (
2936 OK_Convert_To (RTE (RE_Finalizable), Cref)))),
2938 Else_Statements => New_List (
2939 Make_Procedure_Call_Statement (Loc,
2940 Name => New_Reference_To (Proc, Loc),
2941 Parameter_Associations =>
2942 New_List (Convert_View (Proc, Cref2))))));
2947 end Make_Final_Call;
2949 -------------------------------------
2950 -- Make_Handler_For_Ctrl_Operation --
2951 -------------------------------------
2955 -- when E : others =>
2956 -- Raise_From_Controlled_Operation (X => E);
2961 -- raise Program_Error [finalize raised exception];
2963 -- depending on whether Raise_From_Controlled_Operation is available
2965 function Make_Handler_For_Ctrl_Operation
2966 (Loc : Source_Ptr) return Node_Id
2969 -- Choice parameter (for the first case above)
2971 Raise_Node : Node_Id;
2972 -- Procedure call or raise statement
2975 if RTE_Available (RE_Raise_From_Controlled_Operation) then
2977 -- Standard runtime: add choice parameter E, and pass it to
2978 -- Raise_From_Controlled_Operation so that the original exception
2979 -- name and message can be recorded in the exception message for
2982 E_Occ := Make_Defining_Identifier (Loc, Name_E);
2983 Raise_Node := Make_Procedure_Call_Statement (Loc,
2986 RTE (RE_Raise_From_Controlled_Operation), Loc),
2987 Parameter_Associations => New_List (
2988 New_Occurrence_Of (E_Occ, Loc)));
2991 -- Restricted runtime: exception messages are not supported
2994 Raise_Node := Make_Raise_Program_Error (Loc,
2995 Reason => PE_Finalize_Raised_Exception);
2998 return Make_Implicit_Exception_Handler (Loc,
2999 Exception_Choices => New_List (Make_Others_Choice (Loc)),
3000 Choice_Parameter => E_Occ,
3001 Statements => New_List (Raise_Node));
3002 end Make_Handler_For_Ctrl_Operation;
3004 --------------------
3005 -- Make_Init_Call --
3006 --------------------
3008 function Make_Init_Call
3011 Flist_Ref : Node_Id;
3012 With_Attach : Node_Id) return List_Id
3014 Loc : constant Source_Ptr := Sloc (Ref);
3016 Res : constant List_Id := New_List;
3021 Attach : Node_Id := With_Attach;
3024 if Is_Concurrent_Type (Typ) then
3026 Utyp := Corresponding_Record_Type (Typ);
3027 Cref := Convert_Concurrent (Ref, Typ);
3029 elsif Is_Private_Type (Typ)
3030 and then Present (Full_View (Typ))
3031 and then Is_Concurrent_Type (Underlying_Type (Typ))
3034 Utyp := Corresponding_Record_Type (Underlying_Type (Typ));
3035 Cref := Convert_Concurrent (Ref, Underlying_Type (Typ));
3043 Utyp := Underlying_Type (Base_Type (Utyp));
3045 Set_Assignment_OK (Cref);
3047 -- Deal with non-tagged derivation of private views
3049 if Is_Untagged_Derivation (Typ)
3050 and then not Is_Conc
3052 Utyp := Underlying_Type (Root_Type (Base_Type (Typ)));
3053 Cref := Unchecked_Convert_To (Utyp, Cref);
3054 Set_Assignment_OK (Cref);
3055 -- To prevent problems with UC see 1.156 RH ???
3058 -- If the underlying_type is a subtype, we are dealing with
3059 -- the completion of a private type. We need to access
3060 -- the base type and generate a conversion to it.
3062 if Utyp /= Base_Type (Utyp) then
3063 pragma Assert (Is_Private_Type (Typ));
3064 Utyp := Base_Type (Utyp);
3065 Cref := Unchecked_Convert_To (Utyp, Cref);
3068 -- We do not need to attach to one of the Global Final Lists
3069 -- the objects whose type is Finalize_Storage_Only
3071 if Finalize_Storage_Only (Typ)
3072 and then (Global_Flist_Ref (Flist_Ref)
3073 or else Entity (Constant_Value (RTE (RE_Garbage_Collected)))
3076 Attach := Make_Integer_Literal (Loc, 0);
3080 -- Deep_Initialize (Ref, Flist_Ref);
3082 if Has_Controlled_Component (Utyp) then
3083 Proc := TSS (Utyp, Deep_Name_Of (Initialize_Case));
3085 Cref := Convert_View (Proc, Cref, 2);
3088 Make_Procedure_Call_Statement (Loc,
3089 Name => New_Reference_To (Proc, Loc),
3090 Parameter_Associations => New_List (
3096 -- Attach_To_Final_List (Ref, Flist_Ref);
3097 -- Initialize (Ref);
3099 else -- Is_Controlled (Utyp)
3100 Proc := Find_Prim_Op (Utyp, Name_Of (Initialize_Case));
3101 Check_Visibly_Controlled (Initialize_Case, Typ, Proc, Cref);
3103 Cref := Convert_View (Proc, Cref);
3104 Cref2 := New_Copy_Tree (Cref);
3107 Make_Procedure_Call_Statement (Loc,
3108 Name => New_Reference_To (Proc, Loc),
3109 Parameter_Associations => New_List (Cref2)));
3112 Make_Attach_Call (Cref, Flist_Ref, Attach));
3118 --------------------------
3119 -- Make_Transient_Block --
3120 --------------------------
3122 -- If finalization is involved, this function just wraps the instruction
3123 -- into a block whose name is the transient block entity, and then
3124 -- Expand_Cleanup_Actions (called on the expansion of the handled
3125 -- sequence of statements will do the necessary expansions for
3128 function Make_Transient_Block
3130 Action : Node_Id) return Node_Id
3132 Flist : constant Entity_Id := Finalization_Chain_Entity (Current_Scope);
3133 Decls : constant List_Id := New_List;
3134 Par : constant Node_Id := Parent (Action);
3135 Instrs : constant List_Id := New_List (Action);
3139 -- Case where only secondary stack use is involved
3141 if VM_Target = No_VM
3142 and then Uses_Sec_Stack (Current_Scope)
3144 and then Nkind (Action) /= N_Simple_Return_Statement
3145 and then Nkind (Par) /= N_Exception_Handler
3152 S := Scope (Current_Scope);
3156 -- At the outer level, no need to release the sec stack
3158 if S = Standard_Standard then
3159 Set_Uses_Sec_Stack (Current_Scope, False);
3162 -- In a function, only release the sec stack if the
3163 -- function does not return on the sec stack otherwise
3164 -- the result may be lost. The caller is responsible for
3167 elsif K = E_Function then
3168 Set_Uses_Sec_Stack (Current_Scope, False);
3170 if not Requires_Transient_Scope (Etype (S)) then
3171 Set_Uses_Sec_Stack (S, True);
3172 Check_Restriction (No_Secondary_Stack, Action);
3177 -- In a loop or entry we should install a block encompassing
3178 -- all the construct. For now just release right away.
3180 elsif K = E_Loop or else K = E_Entry then
3183 -- In a procedure or a block, we release on exit of the
3184 -- procedure or block. ??? memory leak can be created by
3187 elsif K = E_Procedure
3190 Set_Uses_Sec_Stack (S, True);
3191 Check_Restriction (No_Secondary_Stack, Action);
3192 Set_Uses_Sec_Stack (Current_Scope, False);
3202 -- Insert actions stuck in the transient scopes as well as all
3203 -- freezing nodes needed by those actions
3205 Insert_Actions_In_Scope_Around (Action);
3208 Last_Inserted : Node_Id := Prev (Action);
3210 if Present (Last_Inserted) then
3211 Freeze_All (First_Entity (Current_Scope), Last_Inserted);
3216 Make_Block_Statement (Loc,
3217 Identifier => New_Reference_To (Current_Scope, Loc),
3218 Declarations => Decls,
3219 Handled_Statement_Sequence =>
3220 Make_Handled_Sequence_Of_Statements (Loc, Statements => Instrs),
3221 Has_Created_Identifier => True);
3223 -- When the transient scope was established, we pushed the entry for
3224 -- the transient scope onto the scope stack, so that the scope was
3225 -- active for the installation of finalizable entities etc. Now we
3226 -- must remove this entry, since we have constructed a proper block.
3231 end Make_Transient_Block;
3233 ------------------------
3234 -- Needs_Finalization --
3235 ------------------------
3237 function Needs_Finalization (T : Entity_Id) return Boolean is
3239 function Has_Some_Controlled_Component (Rec : Entity_Id) return Boolean;
3240 -- If type is not frozen yet, check explicitly among its components,
3241 -- because the Has_Controlled_Component flag is not necessarily set.
3243 -----------------------------------
3244 -- Has_Some_Controlled_Component --
3245 -----------------------------------
3247 function Has_Some_Controlled_Component
3248 (Rec : Entity_Id) return Boolean
3253 if Has_Controlled_Component (Rec) then
3256 elsif not Is_Frozen (Rec) then
3257 if Is_Record_Type (Rec) then
3258 Comp := First_Entity (Rec);
3260 while Present (Comp) loop
3261 if not Is_Type (Comp)
3262 and then Needs_Finalization (Etype (Comp))
3272 elsif Is_Array_Type (Rec) then
3273 return Needs_Finalization (Component_Type (Rec));
3276 return Has_Controlled_Component (Rec);
3281 end Has_Some_Controlled_Component;
3283 -- Start of processing for Needs_Finalization
3286 -- Class-wide types must be treated as controlled because they may
3287 -- contain an extension that has controlled components
3289 -- We can skip this if finalization is not available
3291 return (Is_Class_Wide_Type (T)
3292 and then not In_Finalization_Root (T)
3293 and then not Restriction_Active (No_Finalization))
3294 or else Is_Controlled (T)
3295 or else Has_Some_Controlled_Component (T)
3296 or else (Is_Concurrent_Type (T)
3297 and then Present (Corresponding_Record_Type (T))
3298 and then Needs_Finalization (Corresponding_Record_Type (T)));
3299 end Needs_Finalization;
3301 ------------------------
3302 -- Node_To_Be_Wrapped --
3303 ------------------------
3305 function Node_To_Be_Wrapped return Node_Id is
3307 return Scope_Stack.Table (Scope_Stack.Last).Node_To_Be_Wrapped;
3308 end Node_To_Be_Wrapped;
3310 ----------------------------
3311 -- Set_Node_To_Be_Wrapped --
3312 ----------------------------
3314 procedure Set_Node_To_Be_Wrapped (N : Node_Id) is
3316 Scope_Stack.Table (Scope_Stack.Last).Node_To_Be_Wrapped := N;
3317 end Set_Node_To_Be_Wrapped;
3319 ----------------------------------
3320 -- Store_After_Actions_In_Scope --
3321 ----------------------------------
3323 procedure Store_After_Actions_In_Scope (L : List_Id) is
3324 SE : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
3327 if Present (SE.Actions_To_Be_Wrapped_After) then
3328 Insert_List_Before_And_Analyze (
3329 First (SE.Actions_To_Be_Wrapped_After), L);
3332 SE.Actions_To_Be_Wrapped_After := L;
3334 if Is_List_Member (SE.Node_To_Be_Wrapped) then
3335 Set_Parent (L, Parent (SE.Node_To_Be_Wrapped));
3337 Set_Parent (L, SE.Node_To_Be_Wrapped);
3342 end Store_After_Actions_In_Scope;
3344 -----------------------------------
3345 -- Store_Before_Actions_In_Scope --
3346 -----------------------------------
3348 procedure Store_Before_Actions_In_Scope (L : List_Id) is
3349 SE : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
3352 if Present (SE.Actions_To_Be_Wrapped_Before) then
3353 Insert_List_After_And_Analyze (
3354 Last (SE.Actions_To_Be_Wrapped_Before), L);
3357 SE.Actions_To_Be_Wrapped_Before := L;
3359 if Is_List_Member (SE.Node_To_Be_Wrapped) then
3360 Set_Parent (L, Parent (SE.Node_To_Be_Wrapped));
3362 Set_Parent (L, SE.Node_To_Be_Wrapped);
3367 end Store_Before_Actions_In_Scope;
3369 --------------------------------
3370 -- Wrap_Transient_Declaration --
3371 --------------------------------
3373 -- If a transient scope has been established during the processing of the
3374 -- Expression of an Object_Declaration, it is not possible to wrap the
3375 -- declaration into a transient block as usual case, otherwise the object
3376 -- would be itself declared in the wrong scope. Therefore, all entities (if
3377 -- any) defined in the transient block are moved to the proper enclosing
3378 -- scope, furthermore, if they are controlled variables they are finalized
3379 -- right after the declaration. The finalization list of the transient
3380 -- scope is defined as a renaming of the enclosing one so during their
3381 -- initialization they will be attached to the proper finalization
3382 -- list. For instance, the following declaration :
3384 -- X : Typ := F (G (A), G (B));
3386 -- (where G(A) and G(B) return controlled values, expanded as _v1 and _v2)
3387 -- is expanded into :
3389 -- _local_final_list_1 : Finalizable_Ptr;
3390 -- X : Typ := [ complex Expression-Action ];
3391 -- Finalize_One(_v1);
3392 -- Finalize_One (_v2);
3394 procedure Wrap_Transient_Declaration (N : Node_Id) is
3396 LC : Entity_Id := Empty;
3398 Loc : constant Source_Ptr := Sloc (N);
3399 First_Decl_Loc : Source_Ptr;
3400 Enclosing_S : Entity_Id;
3402 Next_N : constant Node_Id := Next (N);
3406 Enclosing_S := Scope (S);
3408 -- Insert Actions kept in the Scope stack
3410 Insert_Actions_In_Scope_Around (N);
3412 -- If the declaration is consuming some secondary stack, mark the
3413 -- Enclosing scope appropriately.
3415 Uses_SS := Uses_Sec_Stack (S);
3418 -- Create a List controller and rename the final list to be its
3419 -- internal final pointer:
3420 -- Lxxx : Simple_List_Controller;
3421 -- Fxxx : Finalizable_Ptr renames Lxxx.F;
3423 if Present (Finalization_Chain_Entity (S)) then
3424 LC := Make_Defining_Identifier (Loc, New_Internal_Name ('L'));
3426 -- Use the Sloc of the first declaration of N's containing list, to
3427 -- maintain monotonicity of source-line stepping during debugging.
3429 First_Decl_Loc := Sloc (First (List_Containing (N)));
3432 Make_Object_Declaration (First_Decl_Loc,
3433 Defining_Identifier => LC,
3434 Object_Definition =>
3436 (RTE (RE_Simple_List_Controller), First_Decl_Loc)),
3438 Make_Object_Renaming_Declaration (First_Decl_Loc,
3439 Defining_Identifier => Finalization_Chain_Entity (S),
3441 New_Reference_To (RTE (RE_Finalizable_Ptr), First_Decl_Loc),
3443 Make_Selected_Component (Loc,
3444 Prefix => New_Reference_To (LC, First_Decl_Loc),
3445 Selector_Name => Make_Identifier (First_Decl_Loc, Name_F))));
3447 -- Put the declaration at the beginning of the declaration part
3448 -- to make sure it will be before all other actions that have been
3449 -- inserted before N.
3451 Insert_List_Before_And_Analyze (First (List_Containing (N)), Nodes);
3453 -- Generate the Finalization calls by finalizing the list controller
3454 -- right away. It will be re-finalized on scope exit but it doesn't
3455 -- matter. It cannot be done when the call initializes a renaming
3456 -- object though because in this case, the object becomes a pointer
3457 -- to the temporary and thus increases its life span. Ditto if this
3458 -- is a renaming of a component of an expression (such as a function
3461 -- Note that there is a problem if an actual in the call needs
3462 -- finalization, because in that case the call itself is the master,
3463 -- and the actual should be finalized on return from the call ???
3465 if Nkind (N) = N_Object_Renaming_Declaration
3466 and then Needs_Finalization (Etype (Defining_Identifier (N)))
3470 elsif Nkind (N) = N_Object_Renaming_Declaration
3472 Nkind_In (Renamed_Object (Defining_Identifier (N)),
3473 N_Selected_Component,
3474 N_Indexed_Component)
3477 (Etype (Prefix (Renamed_Object (Defining_Identifier (N)))))
3484 (Ref => New_Reference_To (LC, Loc),
3486 With_Detach => New_Reference_To (Standard_False, Loc));
3488 if Present (Next_N) then
3489 Insert_List_Before_And_Analyze (Next_N, Nodes);
3491 Append_List_To (List_Containing (N), Nodes);
3496 -- Put the local entities back in the enclosing scope, and set the
3497 -- Is_Public flag appropriately.
3499 Transfer_Entities (S, Enclosing_S);
3501 -- Mark the enclosing dynamic scope so that the sec stack will be
3502 -- released upon its exit unless this is a function that returns on
3503 -- the sec stack in which case this will be done by the caller.
3505 if VM_Target = No_VM and then Uses_SS then
3506 S := Enclosing_Dynamic_Scope (S);
3508 if Ekind (S) = E_Function
3509 and then Requires_Transient_Scope (Etype (S))
3513 Set_Uses_Sec_Stack (S);
3514 Check_Restriction (No_Secondary_Stack, N);
3517 end Wrap_Transient_Declaration;
3519 -------------------------------
3520 -- Wrap_Transient_Expression --
3521 -------------------------------
3523 -- Insert actions before <Expression>:
3525 -- (lines marked with <CTRL> are expanded only in presence of Controlled
3526 -- objects needing finalization)
3530 -- _M : constant Mark_Id := SS_Mark;
3531 -- Local_Final_List : System.FI.Finalizable_Ptr; <CTRL>
3533 -- procedure _Clean is
3536 -- System.FI.Finalize_List (Local_Final_List); <CTRL>
3542 -- _E := <Expression>;
3547 -- then expression is replaced by _E
3549 procedure Wrap_Transient_Expression (N : Node_Id) is
3550 Loc : constant Source_Ptr := Sloc (N);
3551 E : constant Entity_Id :=
3552 Make_Defining_Identifier (Loc, New_Internal_Name ('E'));
3553 Etyp : constant Entity_Id := Etype (N);
3556 Insert_Actions (N, New_List (
3557 Make_Object_Declaration (Loc,
3558 Defining_Identifier => E,
3559 Object_Definition => New_Reference_To (Etyp, Loc)),
3561 Make_Transient_Block (Loc,
3563 Make_Assignment_Statement (Loc,
3564 Name => New_Reference_To (E, Loc),
3565 Expression => Relocate_Node (N)))));
3567 Rewrite (N, New_Reference_To (E, Loc));
3568 Analyze_And_Resolve (N, Etyp);
3569 end Wrap_Transient_Expression;
3571 ------------------------------
3572 -- Wrap_Transient_Statement --
3573 ------------------------------
3575 -- Transform <Instruction> into
3577 -- (lines marked with <CTRL> are expanded only in presence of Controlled
3578 -- objects needing finalization)
3581 -- _M : Mark_Id := SS_Mark;
3582 -- Local_Final_List : System.FI.Finalizable_Ptr ; <CTRL>
3584 -- procedure _Clean is
3587 -- System.FI.Finalize_List (Local_Final_List); <CTRL>
3598 procedure Wrap_Transient_Statement (N : Node_Id) is
3599 Loc : constant Source_Ptr := Sloc (N);
3600 New_Statement : constant Node_Id := Relocate_Node (N);
3603 Rewrite (N, Make_Transient_Block (Loc, New_Statement));
3605 -- With the scope stack back to normal, we can call analyze on the
3606 -- resulting block. At this point, the transient scope is being
3607 -- treated like a perfectly normal scope, so there is nothing
3608 -- special about it.
3610 -- Note: Wrap_Transient_Statement is called with the node already
3611 -- analyzed (i.e. Analyzed (N) is True). This is important, since
3612 -- otherwise we would get a recursive processing of the node when
3613 -- we do this Analyze call.
3616 end Wrap_Transient_Statement;