2014-10-30 Yannick Moy <moy@adacore.com>
[official-gcc.git] / gcc / ada / exp_ch7.adb
blob8d5dd36aee864b504a1831698f5f7d6194bad13f
1 ------------------------------------------------------------------------------
2 -- --
3 -- GNAT COMPILER COMPONENTS --
4 -- --
5 -- E X P _ C H 7 --
6 -- --
7 -- B o d y --
8 -- --
9 -- Copyright (C) 1992-2014, Free Software Foundation, Inc. --
10 -- --
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. --
20 -- --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
23 -- --
24 ------------------------------------------------------------------------------
26 -- This package contains virtually all expansion mechanisms related to
27 -- - controlled types
28 -- - transient scopes
30 with Atree; use Atree;
31 with Debug; use Debug;
32 with Einfo; use Einfo;
33 with Elists; use Elists;
34 with Errout; use Errout;
35 with Exp_Ch6; use Exp_Ch6;
36 with Exp_Ch9; use Exp_Ch9;
37 with Exp_Ch11; use Exp_Ch11;
38 with Exp_Dbug; use Exp_Dbug;
39 with Exp_Dist; use Exp_Dist;
40 with Exp_Disp; use Exp_Disp;
41 with Exp_Prag; use Exp_Prag;
42 with Exp_Tss; use Exp_Tss;
43 with Exp_Util; use Exp_Util;
44 with Freeze; use Freeze;
45 with Lib; use Lib;
46 with Nlists; use Nlists;
47 with Nmake; use Nmake;
48 with Opt; use Opt;
49 with Output; use Output;
50 with Restrict; use Restrict;
51 with Rident; use Rident;
52 with Rtsfind; use Rtsfind;
53 with Sinfo; use Sinfo;
54 with Sem; use Sem;
55 with Sem_Aux; use Sem_Aux;
56 with Sem_Ch3; use Sem_Ch3;
57 with Sem_Ch7; use Sem_Ch7;
58 with Sem_Ch8; use Sem_Ch8;
59 with Sem_Res; use Sem_Res;
60 with Sem_Util; use Sem_Util;
61 with Snames; use Snames;
62 with Stand; use Stand;
63 with Targparm; use Targparm;
64 with Tbuild; use Tbuild;
65 with Ttypes; use Ttypes;
66 with Uintp; use Uintp;
68 package body Exp_Ch7 is
70 --------------------------------
71 -- Transient Scope Management --
72 --------------------------------
74 -- A transient scope is created when temporary objects are created by the
75 -- compiler. These temporary objects are allocated on the secondary stack
76 -- and the transient scope is responsible for finalizing the object when
77 -- appropriate and reclaiming the memory at the right time. The temporary
78 -- objects are generally the objects allocated to store the result of a
79 -- function returning an unconstrained or a tagged value. Expressions
80 -- needing to be wrapped in a transient scope (functions calls returning
81 -- unconstrained or tagged values) may appear in 3 different contexts which
82 -- lead to 3 different kinds of transient scope expansion:
84 -- 1. In a simple statement (procedure call, assignment, ...). In this
85 -- case the instruction is wrapped into a transient block. See
86 -- Wrap_Transient_Statement for details.
88 -- 2. In an expression of a control structure (test in a IF statement,
89 -- expression in a CASE statement, ...). See Wrap_Transient_Expression
90 -- for details.
92 -- 3. In a expression of an object_declaration. No wrapping is possible
93 -- here, so the finalization actions, if any, are done right after the
94 -- declaration and the secondary stack deallocation is done in the
95 -- proper enclosing scope. See Wrap_Transient_Declaration for details.
97 -- Note about functions returning tagged types: it has been decided to
98 -- always allocate their result in the secondary stack, even though is not
99 -- absolutely mandatory when the tagged type is constrained because the
100 -- caller knows the size of the returned object and thus could allocate the
101 -- result in the primary stack. An exception to this is when the function
102 -- builds its result in place, as is done for functions with inherently
103 -- limited result types for Ada 2005. In that case, certain callers may
104 -- pass the address of a constrained object as the target object for the
105 -- function result.
107 -- By allocating tagged results in the secondary stack a number of
108 -- implementation difficulties are avoided:
110 -- - If it is a dispatching function call, the computation of the size of
111 -- the result is possible but complex from the outside.
113 -- - If the returned type is controlled, the assignment of the returned
114 -- value to the anonymous object involves an Adjust, and we have no
115 -- easy way to access the anonymous object created by the back end.
117 -- - If the returned type is class-wide, this is an unconstrained type
118 -- anyway.
120 -- Furthermore, the small loss in efficiency which is the result of this
121 -- decision is not such a big deal because functions returning tagged types
122 -- are not as common in practice compared to functions returning access to
123 -- a tagged type.
125 --------------------------------------------------
126 -- Transient Blocks and Finalization Management --
127 --------------------------------------------------
129 function Find_Node_To_Be_Wrapped (N : Node_Id) return Node_Id;
130 -- N is a node which may generate a transient scope. Loop over the parent
131 -- pointers of N until it find the appropriate node to wrap. If it returns
132 -- Empty, it means that no transient scope is needed in this context.
134 procedure Insert_Actions_In_Scope_Around
135 (N : Node_Id;
136 Clean : Boolean;
137 Manage_SS : Boolean);
138 -- Insert the before-actions kept in the scope stack before N, and the
139 -- after-actions after N, which must be a member of a list. If flag Clean
140 -- is set, insert any cleanup actions. If flag Manage_SS is set, insert
141 -- calls to mark and release the secondary stack.
143 function Make_Transient_Block
144 (Loc : Source_Ptr;
145 Action : Node_Id;
146 Par : Node_Id) return Node_Id;
147 -- Action is a single statement or object declaration. Par is the proper
148 -- parent of the generated block. Create a transient block whose name is
149 -- the current scope and the only handled statement is Action. If Action
150 -- involves controlled objects or secondary stack usage, the corresponding
151 -- cleanup actions are performed at the end of the block.
153 procedure Set_Node_To_Be_Wrapped (N : Node_Id);
154 -- Set the field Node_To_Be_Wrapped of the current scope
156 -- ??? The entire comment needs to be rewritten
157 -- ??? which entire comment?
159 procedure Store_Actions_In_Scope (AK : Scope_Action_Kind; L : List_Id);
160 -- Shared processing for Store_xxx_Actions_In_Scope
162 -----------------------------
163 -- Finalization Management --
164 -----------------------------
166 -- This part describe how Initialization/Adjustment/Finalization procedures
167 -- are generated and called. Two cases must be considered, types that are
168 -- Controlled (Is_Controlled flag set) and composite types that contain
169 -- controlled components (Has_Controlled_Component flag set). In the first
170 -- case the procedures to call are the user-defined primitive operations
171 -- Initialize/Adjust/Finalize. In the second case, GNAT generates
172 -- Deep_Initialize, Deep_Adjust and Deep_Finalize that are in charge
173 -- of calling the former procedures on the controlled components.
175 -- For records with Has_Controlled_Component set, a hidden "controller"
176 -- component is inserted. This controller component contains its own
177 -- finalization list on which all controlled components are attached
178 -- creating an indirection on the upper-level Finalization list. This
179 -- technique facilitates the management of objects whose number of
180 -- controlled components changes during execution. This controller
181 -- component is itself controlled and is attached to the upper-level
182 -- finalization chain. Its adjust primitive is in charge of calling adjust
183 -- on the components and adjusting the finalization pointer to match their
184 -- new location (see a-finali.adb).
186 -- It is not possible to use a similar technique for arrays that have
187 -- Has_Controlled_Component set. In this case, deep procedures are
188 -- generated that call initialize/adjust/finalize + attachment or
189 -- detachment on the finalization list for all component.
191 -- Initialize calls: they are generated for declarations or dynamic
192 -- allocations of Controlled objects with no initial value. They are always
193 -- followed by an attachment to the current Finalization Chain. For the
194 -- dynamic allocation case this the chain attached to the scope of the
195 -- access type definition otherwise, this is the chain of the current
196 -- scope.
198 -- Adjust Calls: They are generated on 2 occasions: (1) for declarations
199 -- or dynamic allocations of Controlled objects with an initial value.
200 -- (2) after an assignment. In the first case they are followed by an
201 -- attachment to the final chain, in the second case they are not.
203 -- Finalization Calls: They are generated on (1) scope exit, (2)
204 -- assignments, (3) unchecked deallocations. In case (3) they have to
205 -- be detached from the final chain, in case (2) they must not and in
206 -- case (1) this is not important since we are exiting the scope anyway.
208 -- Other details:
210 -- Type extensions will have a new record controller at each derivation
211 -- level containing controlled components. The record controller for
212 -- the parent/ancestor is attached to the finalization list of the
213 -- extension's record controller (i.e. the parent is like a component
214 -- of the extension).
216 -- For types that are both Is_Controlled and Has_Controlled_Components,
217 -- the record controller and the object itself are handled separately.
218 -- It could seem simpler to attach the object at the end of its record
219 -- controller but this would not tackle view conversions properly.
221 -- A classwide type can always potentially have controlled components
222 -- but the record controller of the corresponding actual type may not
223 -- be known at compile time so the dispatch table contains a special
224 -- field that allows computation of the offset of the record controller
225 -- dynamically. See s-finimp.Deep_Tag_Attach and a-tags.RC_Offset.
227 -- Here is a simple example of the expansion of a controlled block :
229 -- declare
230 -- X : Controlled;
231 -- Y : Controlled := Init;
233 -- type R is record
234 -- C : Controlled;
235 -- end record;
236 -- W : R;
237 -- Z : R := (C => X);
239 -- begin
240 -- X := Y;
241 -- W := Z;
242 -- end;
244 -- is expanded into
246 -- declare
247 -- _L : System.FI.Finalizable_Ptr;
249 -- procedure _Clean is
250 -- begin
251 -- Abort_Defer;
252 -- System.FI.Finalize_List (_L);
253 -- Abort_Undefer;
254 -- end _Clean;
256 -- X : Controlled;
257 -- begin
258 -- Abort_Defer;
259 -- Initialize (X);
260 -- Attach_To_Final_List (_L, Finalizable (X), 1);
261 -- at end: Abort_Undefer;
262 -- Y : Controlled := Init;
263 -- Adjust (Y);
264 -- Attach_To_Final_List (_L, Finalizable (Y), 1);
266 -- type R is record
267 -- C : Controlled;
268 -- end record;
269 -- W : R;
270 -- begin
271 -- Abort_Defer;
272 -- Deep_Initialize (W, _L, 1);
273 -- at end: Abort_Under;
274 -- Z : R := (C => X);
275 -- Deep_Adjust (Z, _L, 1);
277 -- begin
278 -- _Assign (X, Y);
279 -- Deep_Finalize (W, False);
280 -- <save W's final pointers>
281 -- W := Z;
282 -- <restore W's final pointers>
283 -- Deep_Adjust (W, _L, 0);
284 -- at end
285 -- _Clean;
286 -- end;
288 type Final_Primitives is
289 (Initialize_Case, Adjust_Case, Finalize_Case, Address_Case);
290 -- This enumeration type is defined in order to ease sharing code for
291 -- building finalization procedures for composite types.
293 Name_Of : constant array (Final_Primitives) of Name_Id :=
294 (Initialize_Case => Name_Initialize,
295 Adjust_Case => Name_Adjust,
296 Finalize_Case => Name_Finalize,
297 Address_Case => Name_Finalize_Address);
298 Deep_Name_Of : constant array (Final_Primitives) of TSS_Name_Type :=
299 (Initialize_Case => TSS_Deep_Initialize,
300 Adjust_Case => TSS_Deep_Adjust,
301 Finalize_Case => TSS_Deep_Finalize,
302 Address_Case => TSS_Finalize_Address);
304 procedure Build_Array_Deep_Procs (Typ : Entity_Id);
305 -- Build the deep Initialize/Adjust/Finalize for a record Typ with
306 -- Has_Controlled_Component set and store them using the TSS mechanism.
308 function Build_Cleanup_Statements
309 (N : Node_Id;
310 Additional_Cleanup : List_Id) return List_Id;
311 -- Create the clean up calls for an asynchronous call block, task master,
312 -- protected subprogram body, task allocation block or task body, or
313 -- additional cleanup actions parked on a transient block. If the context
314 -- does not contain the above constructs, the routine returns an empty
315 -- list.
317 procedure Build_Finalizer
318 (N : Node_Id;
319 Clean_Stmts : List_Id;
320 Mark_Id : Entity_Id;
321 Top_Decls : List_Id;
322 Defer_Abort : Boolean;
323 Fin_Id : out Entity_Id);
324 -- N may denote an accept statement, block, entry body, package body,
325 -- package spec, protected body, subprogram body, or a task body. Create
326 -- a procedure which contains finalization calls for all controlled objects
327 -- declared in the declarative or statement region of N. The calls are
328 -- built in reverse order relative to the original declarations. In the
329 -- case of a task body, the routine delays the creation of the finalizer
330 -- until all statements have been moved to the task body procedure.
331 -- Clean_Stmts may contain additional context-dependent code used to abort
332 -- asynchronous calls or complete tasks (see Build_Cleanup_Statements).
333 -- Mark_Id is the secondary stack used in the current context or Empty if
334 -- missing. Top_Decls is the list on which the declaration of the finalizer
335 -- is attached in the non-package case. Defer_Abort indicates that the
336 -- statements passed in perform actions that require abort to be deferred,
337 -- such as for task termination. Fin_Id is the finalizer declaration
338 -- entity.
340 procedure Build_Finalizer_Call (N : Node_Id; Fin_Id : Entity_Id);
341 -- N is a construct which contains a handled sequence of statements, Fin_Id
342 -- is the entity of a finalizer. Create an At_End handler which covers the
343 -- statements of N and calls Fin_Id. If the handled statement sequence has
344 -- an exception handler, the statements will be wrapped in a block to avoid
345 -- unwanted interaction with the new At_End handler.
347 procedure Build_Record_Deep_Procs (Typ : Entity_Id);
348 -- Build the deep Initialize/Adjust/Finalize for a record Typ with
349 -- Has_Component_Component set and store them using the TSS mechanism.
351 procedure Check_Visibly_Controlled
352 (Prim : Final_Primitives;
353 Typ : Entity_Id;
354 E : in out Entity_Id;
355 Cref : in out Node_Id);
356 -- The controlled operation declared for a derived type may not be
357 -- overriding, if the controlled operations of the parent type are hidden,
358 -- for example when the parent is a private type whose full view is
359 -- controlled. For other primitive operations we modify the name of the
360 -- operation to indicate that it is not overriding, but this is not
361 -- possible for Initialize, etc. because they have to be retrievable by
362 -- name. Before generating the proper call to one of these operations we
363 -- check whether Typ is known to be controlled at the point of definition.
364 -- If it is not then we must retrieve the hidden operation of the parent
365 -- and use it instead. This is one case that might be solved more cleanly
366 -- once Overriding pragmas or declarations are in place.
368 function Convert_View
369 (Proc : Entity_Id;
370 Arg : Node_Id;
371 Ind : Pos := 1) return Node_Id;
372 -- Proc is one of the Initialize/Adjust/Finalize operations, and Arg is the
373 -- argument being passed to it. Ind indicates which formal of procedure
374 -- Proc we are trying to match. This function will, if necessary, generate
375 -- a conversion between the partial and full view of Arg to match the type
376 -- of the formal of Proc, or force a conversion to the class-wide type in
377 -- the case where the operation is abstract.
379 function Enclosing_Function (E : Entity_Id) return Entity_Id;
380 -- Given an arbitrary entity, traverse the scope chain looking for the
381 -- first enclosing function. Return Empty if no function was found.
383 function Make_Call
384 (Loc : Source_Ptr;
385 Proc_Id : Entity_Id;
386 Param : Node_Id;
387 Skip_Self : Boolean := False) return Node_Id;
388 -- Subsidiary to Make_Adjust_Call and Make_Final_Call. Given the entity of
389 -- routine [Deep_]Adjust or [Deep_]Finalize and an object parameter, create
390 -- an adjust or finalization call. Wnen flag Skip_Self is set, the related
391 -- action has an effect on the components only (if any).
393 function Make_Deep_Proc
394 (Prim : Final_Primitives;
395 Typ : Entity_Id;
396 Stmts : List_Id) return Node_Id;
397 -- This function generates the tree for Deep_Initialize, Deep_Adjust or
398 -- Deep_Finalize procedures according to the first parameter, these
399 -- procedures operate on the type Typ. The Stmts parameter gives the body
400 -- of the procedure.
402 function Make_Deep_Array_Body
403 (Prim : Final_Primitives;
404 Typ : Entity_Id) return List_Id;
405 -- This function generates the list of statements for implementing
406 -- Deep_Initialize, Deep_Adjust or Deep_Finalize procedures according to
407 -- the first parameter, these procedures operate on the array type Typ.
409 function Make_Deep_Record_Body
410 (Prim : Final_Primitives;
411 Typ : Entity_Id;
412 Is_Local : Boolean := False) return List_Id;
413 -- This function generates the list of statements for implementing
414 -- Deep_Initialize, Deep_Adjust or Deep_Finalize procedures according to
415 -- the first parameter, these procedures operate on the record type Typ.
416 -- Flag Is_Local is used in conjunction with Deep_Finalize to designate
417 -- whether the inner logic should be dictated by state counters.
419 function Make_Finalize_Address_Stmts (Typ : Entity_Id) return List_Id;
420 -- Subsidiary to Make_Finalize_Address_Body, Make_Deep_Array_Body and
421 -- Make_Deep_Record_Body. Generate the following statements:
423 -- declare
424 -- type Acc_Typ is access all Typ;
425 -- for Acc_Typ'Storage_Size use 0;
426 -- begin
427 -- [Deep_]Finalize (Acc_Typ (V).all);
428 -- end;
430 ----------------------------
431 -- Build_Array_Deep_Procs --
432 ----------------------------
434 procedure Build_Array_Deep_Procs (Typ : Entity_Id) is
435 begin
436 Set_TSS (Typ,
437 Make_Deep_Proc
438 (Prim => Initialize_Case,
439 Typ => Typ,
440 Stmts => Make_Deep_Array_Body (Initialize_Case, Typ)));
442 if not Is_Limited_View (Typ) then
443 Set_TSS (Typ,
444 Make_Deep_Proc
445 (Prim => Adjust_Case,
446 Typ => Typ,
447 Stmts => Make_Deep_Array_Body (Adjust_Case, Typ)));
448 end if;
450 -- Do not generate Deep_Finalize and Finalize_Address if finalization is
451 -- suppressed since these routine will not be used.
453 if not Restriction_Active (No_Finalization) then
454 Set_TSS (Typ,
455 Make_Deep_Proc
456 (Prim => Finalize_Case,
457 Typ => Typ,
458 Stmts => Make_Deep_Array_Body (Finalize_Case, Typ)));
460 -- Create TSS primitive Finalize_Address for non-VM targets. JVM and
461 -- .NET do not support address arithmetic and unchecked conversions.
463 if VM_Target = No_VM then
464 Set_TSS (Typ,
465 Make_Deep_Proc
466 (Prim => Address_Case,
467 Typ => Typ,
468 Stmts => Make_Deep_Array_Body (Address_Case, Typ)));
469 end if;
470 end if;
471 end Build_Array_Deep_Procs;
473 ------------------------------
474 -- Build_Cleanup_Statements --
475 ------------------------------
477 function Build_Cleanup_Statements
478 (N : Node_Id;
479 Additional_Cleanup : List_Id) return List_Id
481 Is_Asynchronous_Call : constant Boolean :=
482 Nkind (N) = N_Block_Statement
483 and then Is_Asynchronous_Call_Block (N);
484 Is_Master : constant Boolean :=
485 Nkind (N) /= N_Entry_Body
486 and then Is_Task_Master (N);
487 Is_Protected_Body : constant Boolean :=
488 Nkind (N) = N_Subprogram_Body
489 and then Is_Protected_Subprogram_Body (N);
490 Is_Task_Allocation : constant Boolean :=
491 Nkind (N) = N_Block_Statement
492 and then Is_Task_Allocation_Block (N);
493 Is_Task_Body : constant Boolean :=
494 Nkind (Original_Node (N)) = N_Task_Body;
496 Loc : constant Source_Ptr := Sloc (N);
497 Stmts : constant List_Id := New_List;
499 begin
500 if Is_Task_Body then
501 if Restricted_Profile then
502 Append_To (Stmts,
503 Build_Runtime_Call (Loc, RE_Complete_Restricted_Task));
504 else
505 Append_To (Stmts, Build_Runtime_Call (Loc, RE_Complete_Task));
506 end if;
508 elsif Is_Master then
509 if Restriction_Active (No_Task_Hierarchy) = False then
510 Append_To (Stmts, Build_Runtime_Call (Loc, RE_Complete_Master));
511 end if;
513 -- Add statements to unlock the protected object parameter and to
514 -- undefer abort. If the context is a protected procedure and the object
515 -- has entries, call the entry service routine.
517 -- NOTE: The generated code references _object, a parameter to the
518 -- procedure.
520 elsif Is_Protected_Body then
521 declare
522 Spec : constant Node_Id := Parent (Corresponding_Spec (N));
523 Conc_Typ : Entity_Id;
524 Param : Node_Id;
525 Param_Typ : Entity_Id;
527 begin
528 -- Find the _object parameter representing the protected object
530 Param := First (Parameter_Specifications (Spec));
531 loop
532 Param_Typ := Etype (Parameter_Type (Param));
534 if Ekind (Param_Typ) = E_Record_Type then
535 Conc_Typ := Corresponding_Concurrent_Type (Param_Typ);
536 end if;
538 exit when No (Param) or else Present (Conc_Typ);
539 Next (Param);
540 end loop;
542 pragma Assert (Present (Param));
544 -- Historical note: In earlier versions of GNAT, there was code
545 -- at this point to generate stuff to service entry queues. It is
546 -- now abstracted in Build_Protected_Subprogram_Call_Cleanup.
548 Build_Protected_Subprogram_Call_Cleanup
549 (Specification (N), Conc_Typ, Loc, Stmts);
550 end;
552 -- Add a call to Expunge_Unactivated_Tasks for dynamically allocated
553 -- tasks. Other unactivated tasks are completed by Complete_Task or
554 -- Complete_Master.
556 -- NOTE: The generated code references _chain, a local object
558 elsif Is_Task_Allocation then
560 -- Generate:
561 -- Expunge_Unactivated_Tasks (_chain);
563 -- where _chain is the list of tasks created by the allocator but not
564 -- yet activated. This list will be empty unless the block completes
565 -- abnormally.
567 Append_To (Stmts,
568 Make_Procedure_Call_Statement (Loc,
569 Name =>
570 New_Occurrence_Of
571 (RTE (RE_Expunge_Unactivated_Tasks), Loc),
572 Parameter_Associations => New_List (
573 New_Occurrence_Of (Activation_Chain_Entity (N), Loc))));
575 -- Attempt to cancel an asynchronous entry call whenever the block which
576 -- contains the abortable part is exited.
578 -- NOTE: The generated code references Cnn, a local object
580 elsif Is_Asynchronous_Call then
581 declare
582 Cancel_Param : constant Entity_Id :=
583 Entry_Cancel_Parameter (Entity (Identifier (N)));
585 begin
586 -- If it is of type Communication_Block, this must be a protected
587 -- entry call. Generate:
589 -- if Enqueued (Cancel_Param) then
590 -- Cancel_Protected_Entry_Call (Cancel_Param);
591 -- end if;
593 if Is_RTE (Etype (Cancel_Param), RE_Communication_Block) then
594 Append_To (Stmts,
595 Make_If_Statement (Loc,
596 Condition =>
597 Make_Function_Call (Loc,
598 Name =>
599 New_Occurrence_Of (RTE (RE_Enqueued), Loc),
600 Parameter_Associations => New_List (
601 New_Occurrence_Of (Cancel_Param, Loc))),
603 Then_Statements => New_List (
604 Make_Procedure_Call_Statement (Loc,
605 Name =>
606 New_Occurrence_Of
607 (RTE (RE_Cancel_Protected_Entry_Call), Loc),
608 Parameter_Associations => New_List (
609 New_Occurrence_Of (Cancel_Param, Loc))))));
611 -- Asynchronous delay, generate:
612 -- Cancel_Async_Delay (Cancel_Param);
614 elsif Is_RTE (Etype (Cancel_Param), RE_Delay_Block) then
615 Append_To (Stmts,
616 Make_Procedure_Call_Statement (Loc,
617 Name =>
618 New_Occurrence_Of (RTE (RE_Cancel_Async_Delay), Loc),
619 Parameter_Associations => New_List (
620 Make_Attribute_Reference (Loc,
621 Prefix =>
622 New_Occurrence_Of (Cancel_Param, Loc),
623 Attribute_Name => Name_Unchecked_Access))));
625 -- Task entry call, generate:
626 -- Cancel_Task_Entry_Call (Cancel_Param);
628 else
629 Append_To (Stmts,
630 Make_Procedure_Call_Statement (Loc,
631 Name =>
632 New_Occurrence_Of (RTE (RE_Cancel_Task_Entry_Call), Loc),
633 Parameter_Associations => New_List (
634 New_Occurrence_Of (Cancel_Param, Loc))));
635 end if;
636 end;
637 end if;
639 Append_List_To (Stmts, Additional_Cleanup);
640 return Stmts;
641 end Build_Cleanup_Statements;
643 -----------------------------
644 -- Build_Controlling_Procs --
645 -----------------------------
647 procedure Build_Controlling_Procs (Typ : Entity_Id) is
648 begin
649 if Is_Array_Type (Typ) then
650 Build_Array_Deep_Procs (Typ);
651 else pragma Assert (Is_Record_Type (Typ));
652 Build_Record_Deep_Procs (Typ);
653 end if;
654 end Build_Controlling_Procs;
656 -----------------------------
657 -- Build_Exception_Handler --
658 -----------------------------
660 function Build_Exception_Handler
661 (Data : Finalization_Exception_Data;
662 For_Library : Boolean := False) return Node_Id
664 Actuals : List_Id;
665 Proc_To_Call : Entity_Id;
666 Except : Node_Id;
667 Stmts : List_Id;
669 begin
670 pragma Assert (Present (Data.Raised_Id));
672 if Exception_Extra_Info
673 or else (For_Library and not Restricted_Profile)
674 then
675 if Exception_Extra_Info then
677 -- Generate:
679 -- Get_Current_Excep.all
681 Except :=
682 Make_Function_Call (Data.Loc,
683 Name =>
684 Make_Explicit_Dereference (Data.Loc,
685 Prefix =>
686 New_Occurrence_Of
687 (RTE (RE_Get_Current_Excep), Data.Loc)));
689 else
690 -- Generate:
692 -- null
694 Except := Make_Null (Data.Loc);
695 end if;
697 if For_Library and then not Restricted_Profile then
698 Proc_To_Call := RTE (RE_Save_Library_Occurrence);
699 Actuals := New_List (Except);
701 else
702 Proc_To_Call := RTE (RE_Save_Occurrence);
704 -- The dereference occurs only when Exception_Extra_Info is true,
705 -- and therefore Except is not null.
707 Actuals :=
708 New_List (
709 New_Occurrence_Of (Data.E_Id, Data.Loc),
710 Make_Explicit_Dereference (Data.Loc, Except));
711 end if;
713 -- Generate:
715 -- when others =>
716 -- if not Raised_Id then
717 -- Raised_Id := True;
719 -- Save_Occurrence (E_Id, Get_Current_Excep.all.all);
720 -- or
721 -- Save_Library_Occurrence (Get_Current_Excep.all);
722 -- end if;
724 Stmts :=
725 New_List (
726 Make_If_Statement (Data.Loc,
727 Condition =>
728 Make_Op_Not (Data.Loc,
729 Right_Opnd => New_Occurrence_Of (Data.Raised_Id, Data.Loc)),
731 Then_Statements => New_List (
732 Make_Assignment_Statement (Data.Loc,
733 Name => New_Occurrence_Of (Data.Raised_Id, Data.Loc),
734 Expression => New_Occurrence_Of (Standard_True, Data.Loc)),
736 Make_Procedure_Call_Statement (Data.Loc,
737 Name =>
738 New_Occurrence_Of (Proc_To_Call, Data.Loc),
739 Parameter_Associations => Actuals))));
741 else
742 -- Generate:
744 -- Raised_Id := True;
746 Stmts := New_List (
747 Make_Assignment_Statement (Data.Loc,
748 Name => New_Occurrence_Of (Data.Raised_Id, Data.Loc),
749 Expression => New_Occurrence_Of (Standard_True, Data.Loc)));
750 end if;
752 -- Generate:
754 -- when others =>
756 return
757 Make_Exception_Handler (Data.Loc,
758 Exception_Choices => New_List (Make_Others_Choice (Data.Loc)),
759 Statements => Stmts);
760 end Build_Exception_Handler;
762 -------------------------------
763 -- Build_Finalization_Master --
764 -------------------------------
766 procedure Build_Finalization_Master
767 (Typ : Entity_Id;
768 Ins_Node : Node_Id := Empty;
769 Encl_Scope : Entity_Id := Empty)
771 function In_Deallocation_Instance (E : Entity_Id) return Boolean;
772 -- Determine whether entity E is inside a wrapper package created for
773 -- an instance of Ada.Unchecked_Deallocation.
775 ------------------------------
776 -- In_Deallocation_Instance --
777 ------------------------------
779 function In_Deallocation_Instance (E : Entity_Id) return Boolean is
780 Pkg : constant Entity_Id := Scope (E);
781 Par : Node_Id := Empty;
783 begin
784 if Ekind (Pkg) = E_Package
785 and then Present (Related_Instance (Pkg))
786 and then Ekind (Related_Instance (Pkg)) = E_Procedure
787 then
788 Par := Generic_Parent (Parent (Related_Instance (Pkg)));
790 return
791 Present (Par)
792 and then Chars (Par) = Name_Unchecked_Deallocation
793 and then Chars (Scope (Par)) = Name_Ada
794 and then Scope (Scope (Par)) = Standard_Standard;
795 end if;
797 return False;
798 end In_Deallocation_Instance;
800 -- Local variables
802 Desig_Typ : constant Entity_Id := Directly_Designated_Type (Typ);
804 Ptr_Typ : constant Entity_Id := Root_Type_Of_Full_View (Base_Type (Typ));
805 -- A finalization master created for a named access type is associated
806 -- with the full view (if applicable) as a consequence of freezing. The
807 -- full view criteria does not apply to anonymous access types because
808 -- those cannot have a private and a full view.
810 -- Start of processing for Build_Finalization_Master
812 begin
813 -- Certain run-time configurations and targets do not provide support
814 -- for controlled types.
816 if Restriction_Active (No_Finalization) then
817 return;
819 -- Do not process C, C++, CIL and Java types since it is assumend that
820 -- the non-Ada side will handle their clean up.
822 elsif Convention (Desig_Typ) = Convention_C
823 or else Convention (Desig_Typ) = Convention_CIL
824 or else Convention (Desig_Typ) = Convention_CPP
825 or else Convention (Desig_Typ) = Convention_Java
826 then
827 return;
829 -- Various machinery such as freezing may have already created a
830 -- finalization master.
832 elsif Present (Finalization_Master (Ptr_Typ)) then
833 return;
835 -- Do not process types that return on the secondary stack
837 elsif Present (Associated_Storage_Pool (Ptr_Typ))
838 and then Is_RTE (Associated_Storage_Pool (Ptr_Typ), RE_SS_Pool)
839 then
840 return;
842 -- Do not process types which may never allocate an object
844 elsif No_Pool_Assigned (Ptr_Typ) then
845 return;
847 -- Do not process access types coming from Ada.Unchecked_Deallocation
848 -- instances. Even though the designated type may be controlled, the
849 -- access type will never participate in allocation.
851 elsif In_Deallocation_Instance (Ptr_Typ) then
852 return;
854 -- Ignore the general use of anonymous access types unless the context
855 -- requires a finalization master.
857 elsif Ekind (Ptr_Typ) = E_Anonymous_Access_Type
858 and then No (Ins_Node)
859 then
860 return;
862 -- Do not process non-library access types when restriction No_Nested_
863 -- Finalization is in effect since masters are controlled objects.
865 elsif Restriction_Active (No_Nested_Finalization)
866 and then not Is_Library_Level_Entity (Ptr_Typ)
867 then
868 return;
870 -- For .NET/JVM targets, allow the processing of access-to-controlled
871 -- types where the designated type is explicitly derived from [Limited_]
872 -- Controlled.
874 elsif VM_Target /= No_VM and then not Is_Controlled (Desig_Typ) then
875 return;
877 -- Do not create finalization masters in SPARK mode because they result
878 -- in unwanted expansion.
880 -- More detail would be useful here ???
882 elsif GNATprove_Mode then
883 return;
884 end if;
886 declare
887 Loc : constant Source_Ptr := Sloc (Ptr_Typ);
888 Actions : constant List_Id := New_List;
889 Fin_Mas_Id : Entity_Id;
890 Pool_Id : Entity_Id;
892 begin
893 -- Generate:
894 -- Fnn : aliased Finalization_Master;
896 -- Source access types use fixed master names since the master is
897 -- inserted in the same source unit only once. The only exception to
898 -- this are instances using the same access type as generic actual.
900 if Comes_From_Source (Ptr_Typ) and then not Inside_A_Generic then
901 Fin_Mas_Id :=
902 Make_Defining_Identifier (Loc,
903 Chars => New_External_Name (Chars (Ptr_Typ), "FM"));
905 -- Internally generated access types use temporaries as their names
906 -- due to possible collision with identical names coming from other
907 -- packages.
909 else
910 Fin_Mas_Id := Make_Temporary (Loc, 'F');
911 end if;
913 Append_To (Actions,
914 Make_Object_Declaration (Loc,
915 Defining_Identifier => Fin_Mas_Id,
916 Aliased_Present => True,
917 Object_Definition =>
918 New_Occurrence_Of (RTE (RE_Finalization_Master), Loc)));
920 -- Storage pool selection and attribute decoration of the generated
921 -- master. Since .NET/JVM compilers do not support pools, this step
922 -- is skipped.
924 if VM_Target = No_VM then
926 -- If the access type has a user-defined pool, use it as the base
927 -- storage medium for the finalization pool.
929 if Present (Associated_Storage_Pool (Ptr_Typ)) then
930 Pool_Id := Associated_Storage_Pool (Ptr_Typ);
932 -- The default choice is the global pool
934 else
935 Pool_Id := RTE (RE_Global_Pool_Object);
936 Set_Associated_Storage_Pool (Ptr_Typ, Pool_Id);
937 end if;
939 -- Generate:
940 -- Set_Base_Pool (Fnn, Pool_Id'Unchecked_Access);
942 Append_To (Actions,
943 Make_Procedure_Call_Statement (Loc,
944 Name =>
945 New_Occurrence_Of (RTE (RE_Set_Base_Pool), Loc),
946 Parameter_Associations => New_List (
947 New_Occurrence_Of (Fin_Mas_Id, Loc),
948 Make_Attribute_Reference (Loc,
949 Prefix => New_Occurrence_Of (Pool_Id, Loc),
950 Attribute_Name => Name_Unrestricted_Access))));
951 end if;
953 Set_Finalization_Master (Ptr_Typ, Fin_Mas_Id);
955 -- A finalization master created for an anonymous access type must be
956 -- inserted before a context-dependent node.
958 if Present (Ins_Node) then
959 Push_Scope (Encl_Scope);
961 -- Treat use clauses as declarations and insert directly in front
962 -- of them.
964 if Nkind_In (Ins_Node, N_Use_Package_Clause,
965 N_Use_Type_Clause)
966 then
967 Insert_List_Before_And_Analyze (Ins_Node, Actions);
968 else
969 Insert_Actions (Ins_Node, Actions);
970 end if;
972 Pop_Scope;
974 elsif Ekind (Desig_Typ) = E_Incomplete_Type
975 and then Has_Completion_In_Body (Desig_Typ)
976 then
977 Insert_Actions (Parent (Ptr_Typ), Actions);
979 -- If the designated type is not yet frozen, then append the actions
980 -- to that type's freeze actions. The actions need to be appended to
981 -- whichever type is frozen later, similarly to what Freeze_Type does
982 -- for appending the storage pool declaration for an access type.
983 -- Otherwise, the call to Set_Storage_Pool_Ptr might reference the
984 -- pool object before it's declared. However, it's not clear that
985 -- this is exactly the right test to accomplish that here. ???
987 elsif Present (Freeze_Node (Desig_Typ))
988 and then not Analyzed (Freeze_Node (Desig_Typ))
989 then
990 Append_Freeze_Actions (Desig_Typ, Actions);
992 elsif Present (Freeze_Node (Ptr_Typ))
993 and then not Analyzed (Freeze_Node (Ptr_Typ))
994 then
995 Append_Freeze_Actions (Ptr_Typ, Actions);
997 -- If there's a pool created locally for the access type, then we
998 -- need to ensure that the master gets created after the pool object,
999 -- because otherwise we can have a forward reference, so we force the
1000 -- master actions to be inserted and analyzed after the pool entity.
1001 -- Note that both the access type and its designated type may have
1002 -- already been frozen and had their freezing actions analyzed at
1003 -- this point. (This seems a little unclean.???)
1005 elsif VM_Target = No_VM
1006 and then Scope (Pool_Id) = Scope (Ptr_Typ)
1007 then
1008 Insert_List_After_And_Analyze (Parent (Pool_Id), Actions);
1010 else
1011 Insert_Actions (Parent (Ptr_Typ), Actions);
1012 end if;
1013 end;
1014 end Build_Finalization_Master;
1016 ---------------------
1017 -- Build_Finalizer --
1018 ---------------------
1020 procedure Build_Finalizer
1021 (N : Node_Id;
1022 Clean_Stmts : List_Id;
1023 Mark_Id : Entity_Id;
1024 Top_Decls : List_Id;
1025 Defer_Abort : Boolean;
1026 Fin_Id : out Entity_Id)
1028 Acts_As_Clean : constant Boolean :=
1029 Present (Mark_Id)
1030 or else
1031 (Present (Clean_Stmts)
1032 and then Is_Non_Empty_List (Clean_Stmts));
1033 Exceptions_OK : constant Boolean :=
1034 not Restriction_Active (No_Exception_Propagation);
1035 For_Package_Body : constant Boolean := Nkind (N) = N_Package_Body;
1036 For_Package_Spec : constant Boolean := Nkind (N) = N_Package_Declaration;
1037 For_Package : constant Boolean :=
1038 For_Package_Body or else For_Package_Spec;
1039 Loc : constant Source_Ptr := Sloc (N);
1041 -- NOTE: Local variable declarations are conservative and do not create
1042 -- structures right from the start. Entities and lists are created once
1043 -- it has been established that N has at least one controlled object.
1045 Components_Built : Boolean := False;
1046 -- A flag used to avoid double initialization of entities and lists. If
1047 -- the flag is set then the following variables have been initialized:
1048 -- Counter_Id
1049 -- Finalizer_Decls
1050 -- Finalizer_Stmts
1051 -- Jump_Alts
1053 Counter_Id : Entity_Id := Empty;
1054 Counter_Val : Int := 0;
1055 -- Name and value of the state counter
1057 Decls : List_Id := No_List;
1058 -- Declarative region of N (if available). If N is a package declaration
1059 -- Decls denotes the visible declarations.
1061 Finalizer_Data : Finalization_Exception_Data;
1062 -- Data for the exception
1064 Finalizer_Decls : List_Id := No_List;
1065 -- Local variable declarations. This list holds the label declarations
1066 -- of all jump block alternatives as well as the declaration of the
1067 -- local exception occurence and the raised flag:
1068 -- E : Exception_Occurrence;
1069 -- Raised : Boolean := False;
1070 -- L<counter value> : label;
1072 Finalizer_Insert_Nod : Node_Id := Empty;
1073 -- Insertion point for the finalizer body. Depending on the context
1074 -- (Nkind of N) and the individual grouping of controlled objects, this
1075 -- node may denote a package declaration or body, package instantiation,
1076 -- block statement or a counter update statement.
1078 Finalizer_Stmts : List_Id := No_List;
1079 -- The statement list of the finalizer body. It contains the following:
1081 -- Abort_Defer; -- Added if abort is allowed
1082 -- <call to Prev_At_End> -- Added if exists
1083 -- <cleanup statements> -- Added if Acts_As_Clean
1084 -- <jump block> -- Added if Has_Ctrl_Objs
1085 -- <finalization statements> -- Added if Has_Ctrl_Objs
1086 -- <stack release> -- Added if Mark_Id exists
1087 -- Abort_Undefer; -- Added if abort is allowed
1089 Has_Ctrl_Objs : Boolean := False;
1090 -- A general flag which denotes whether N has at least one controlled
1091 -- object.
1093 Has_Tagged_Types : Boolean := False;
1094 -- A general flag which indicates whether N has at least one library-
1095 -- level tagged type declaration.
1097 HSS : Node_Id := Empty;
1098 -- The sequence of statements of N (if available)
1100 Jump_Alts : List_Id := No_List;
1101 -- Jump block alternatives. Depending on the value of the state counter,
1102 -- the control flow jumps to a sequence of finalization statements. This
1103 -- list contains the following:
1105 -- when <counter value> =>
1106 -- goto L<counter value>;
1108 Jump_Block_Insert_Nod : Node_Id := Empty;
1109 -- Specific point in the finalizer statements where the jump block is
1110 -- inserted.
1112 Last_Top_Level_Ctrl_Construct : Node_Id := Empty;
1113 -- The last controlled construct encountered when processing the top
1114 -- level lists of N. This can be a nested package, an instantiation or
1115 -- an object declaration.
1117 Prev_At_End : Entity_Id := Empty;
1118 -- The previous at end procedure of the handled statements block of N
1120 Priv_Decls : List_Id := No_List;
1121 -- The private declarations of N if N is a package declaration
1123 Spec_Id : Entity_Id := Empty;
1124 Spec_Decls : List_Id := Top_Decls;
1125 Stmts : List_Id := No_List;
1127 Tagged_Type_Stmts : List_Id := No_List;
1128 -- Contains calls to Ada.Tags.Unregister_Tag for all library-level
1129 -- tagged types found in N.
1131 -----------------------
1132 -- Local subprograms --
1133 -----------------------
1135 procedure Build_Components;
1136 -- Create all entites and initialize all lists used in the creation of
1137 -- the finalizer.
1139 procedure Create_Finalizer;
1140 -- Create the spec and body of the finalizer and insert them in the
1141 -- proper place in the tree depending on the context.
1143 procedure Process_Declarations
1144 (Decls : List_Id;
1145 Preprocess : Boolean := False;
1146 Top_Level : Boolean := False);
1147 -- Inspect a list of declarations or statements which may contain
1148 -- objects that need finalization. When flag Preprocess is set, the
1149 -- routine will simply count the total number of controlled objects in
1150 -- Decls. Flag Top_Level denotes whether the processing is done for
1151 -- objects in nested package declarations or instances.
1153 procedure Process_Object_Declaration
1154 (Decl : Node_Id;
1155 Has_No_Init : Boolean := False;
1156 Is_Protected : Boolean := False);
1157 -- Generate all the machinery associated with the finalization of a
1158 -- single object. Flag Has_No_Init is used to denote certain contexts
1159 -- where Decl does not have initialization call(s). Flag Is_Protected
1160 -- is set when Decl denotes a simple protected object.
1162 procedure Process_Tagged_Type_Declaration (Decl : Node_Id);
1163 -- Generate all the code necessary to unregister the external tag of a
1164 -- tagged type.
1166 ----------------------
1167 -- Build_Components --
1168 ----------------------
1170 procedure Build_Components is
1171 Counter_Decl : Node_Id;
1172 Counter_Typ : Entity_Id;
1173 Counter_Typ_Decl : Node_Id;
1175 begin
1176 pragma Assert (Present (Decls));
1178 -- This routine might be invoked several times when dealing with
1179 -- constructs that have two lists (either two declarative regions
1180 -- or declarations and statements). Avoid double initialization.
1182 if Components_Built then
1183 return;
1184 end if;
1186 Components_Built := True;
1188 if Has_Ctrl_Objs then
1190 -- Create entities for the counter, its type, the local exception
1191 -- and the raised flag.
1193 Counter_Id := Make_Temporary (Loc, 'C');
1194 Counter_Typ := Make_Temporary (Loc, 'T');
1196 Finalizer_Decls := New_List;
1198 Build_Object_Declarations
1199 (Finalizer_Data, Finalizer_Decls, Loc, For_Package);
1201 -- Since the total number of controlled objects is always known,
1202 -- build a subtype of Natural with precise bounds. This allows
1203 -- the backend to optimize the case statement. Generate:
1205 -- subtype Tnn is Natural range 0 .. Counter_Val;
1207 Counter_Typ_Decl :=
1208 Make_Subtype_Declaration (Loc,
1209 Defining_Identifier => Counter_Typ,
1210 Subtype_Indication =>
1211 Make_Subtype_Indication (Loc,
1212 Subtype_Mark => New_Occurrence_Of (Standard_Natural, Loc),
1213 Constraint =>
1214 Make_Range_Constraint (Loc,
1215 Range_Expression =>
1216 Make_Range (Loc,
1217 Low_Bound =>
1218 Make_Integer_Literal (Loc, Uint_0),
1219 High_Bound =>
1220 Make_Integer_Literal (Loc, Counter_Val)))));
1222 -- Generate the declaration of the counter itself:
1224 -- Counter : Integer := 0;
1226 Counter_Decl :=
1227 Make_Object_Declaration (Loc,
1228 Defining_Identifier => Counter_Id,
1229 Object_Definition => New_Occurrence_Of (Counter_Typ, Loc),
1230 Expression => Make_Integer_Literal (Loc, 0));
1232 -- Set the type of the counter explicitly to prevent errors when
1233 -- examining object declarations later on.
1235 Set_Etype (Counter_Id, Counter_Typ);
1237 -- The counter and its type are inserted before the source
1238 -- declarations of N.
1240 Prepend_To (Decls, Counter_Decl);
1241 Prepend_To (Decls, Counter_Typ_Decl);
1243 -- The counter and its associated type must be manually analized
1244 -- since N has already been analyzed. Use the scope of the spec
1245 -- when inserting in a package.
1247 if For_Package then
1248 Push_Scope (Spec_Id);
1249 Analyze (Counter_Typ_Decl);
1250 Analyze (Counter_Decl);
1251 Pop_Scope;
1253 else
1254 Analyze (Counter_Typ_Decl);
1255 Analyze (Counter_Decl);
1256 end if;
1258 Jump_Alts := New_List;
1259 end if;
1261 -- If the context requires additional clean up, the finalization
1262 -- machinery is added after the clean up code.
1264 if Acts_As_Clean then
1265 Finalizer_Stmts := Clean_Stmts;
1266 Jump_Block_Insert_Nod := Last (Finalizer_Stmts);
1267 else
1268 Finalizer_Stmts := New_List;
1269 end if;
1271 if Has_Tagged_Types then
1272 Tagged_Type_Stmts := New_List;
1273 end if;
1274 end Build_Components;
1276 ----------------------
1277 -- Create_Finalizer --
1278 ----------------------
1280 procedure Create_Finalizer is
1281 Body_Id : Entity_Id;
1282 Fin_Body : Node_Id;
1283 Fin_Spec : Node_Id;
1284 Jump_Block : Node_Id;
1285 Label : Node_Id;
1286 Label_Id : Entity_Id;
1288 function New_Finalizer_Name return Name_Id;
1289 -- Create a fully qualified name of a package spec or body finalizer.
1290 -- The generated name is of the form: xx__yy__finalize_[spec|body].
1292 ------------------------
1293 -- New_Finalizer_Name --
1294 ------------------------
1296 function New_Finalizer_Name return Name_Id is
1297 procedure New_Finalizer_Name (Id : Entity_Id);
1298 -- Place "__<name-of-Id>" in the name buffer. If the identifier
1299 -- has a non-standard scope, process the scope first.
1301 ------------------------
1302 -- New_Finalizer_Name --
1303 ------------------------
1305 procedure New_Finalizer_Name (Id : Entity_Id) is
1306 begin
1307 if Scope (Id) = Standard_Standard then
1308 Get_Name_String (Chars (Id));
1310 else
1311 New_Finalizer_Name (Scope (Id));
1312 Add_Str_To_Name_Buffer ("__");
1313 Add_Str_To_Name_Buffer (Get_Name_String (Chars (Id)));
1314 end if;
1315 end New_Finalizer_Name;
1317 -- Start of processing for New_Finalizer_Name
1319 begin
1320 -- Create the fully qualified name of the enclosing scope
1322 New_Finalizer_Name (Spec_Id);
1324 -- Generate:
1325 -- __finalize_[spec|body]
1327 Add_Str_To_Name_Buffer ("__finalize_");
1329 if For_Package_Spec then
1330 Add_Str_To_Name_Buffer ("spec");
1331 else
1332 Add_Str_To_Name_Buffer ("body");
1333 end if;
1335 return Name_Find;
1336 end New_Finalizer_Name;
1338 -- Start of processing for Create_Finalizer
1340 begin
1341 -- Step 1: Creation of the finalizer name
1343 -- Packages must use a distinct name for their finalizers since the
1344 -- binder will have to generate calls to them by name. The name is
1345 -- of the following form:
1347 -- xx__yy__finalize_[spec|body]
1349 if For_Package then
1350 Fin_Id := Make_Defining_Identifier (Loc, New_Finalizer_Name);
1351 Set_Has_Qualified_Name (Fin_Id);
1352 Set_Has_Fully_Qualified_Name (Fin_Id);
1354 -- The default name is _finalizer
1356 else
1357 Fin_Id :=
1358 Make_Defining_Identifier (Loc,
1359 Chars => New_External_Name (Name_uFinalizer));
1361 -- The visibility semantics of AT_END handlers force a strange
1362 -- separation of spec and body for stack-related finalizers:
1364 -- declare : Enclosing_Scope
1365 -- procedure _finalizer;
1366 -- begin
1367 -- <controlled objects>
1368 -- procedure _finalizer is
1369 -- ...
1370 -- at end
1371 -- _finalizer;
1372 -- end;
1374 -- Both spec and body are within the same construct and scope, but
1375 -- the body is part of the handled sequence of statements. This
1376 -- placement confuses the elaboration mechanism on targets where
1377 -- AT_END handlers are expanded into "when all others" handlers:
1379 -- exception
1380 -- when all others =>
1381 -- _finalizer; -- appears to require elab checks
1382 -- at end
1383 -- _finalizer;
1384 -- end;
1386 -- Since the compiler guarantees that the body of a _finalizer is
1387 -- always inserted in the same construct where the AT_END handler
1388 -- resides, there is no need for elaboration checks.
1390 Set_Kill_Elaboration_Checks (Fin_Id);
1391 end if;
1393 -- Step 2: Creation of the finalizer specification
1395 -- Generate:
1396 -- procedure Fin_Id;
1398 Fin_Spec :=
1399 Make_Subprogram_Declaration (Loc,
1400 Specification =>
1401 Make_Procedure_Specification (Loc,
1402 Defining_Unit_Name => Fin_Id));
1404 -- Step 3: Creation of the finalizer body
1406 if Has_Ctrl_Objs then
1408 -- Add L0, the default destination to the jump block
1410 Label_Id := Make_Identifier (Loc, New_External_Name ('L', 0));
1411 Set_Entity (Label_Id,
1412 Make_Defining_Identifier (Loc, Chars (Label_Id)));
1413 Label := Make_Label (Loc, Label_Id);
1415 -- Generate:
1416 -- L0 : label;
1418 Prepend_To (Finalizer_Decls,
1419 Make_Implicit_Label_Declaration (Loc,
1420 Defining_Identifier => Entity (Label_Id),
1421 Label_Construct => Label));
1423 -- Generate:
1424 -- when others =>
1425 -- goto L0;
1427 Append_To (Jump_Alts,
1428 Make_Case_Statement_Alternative (Loc,
1429 Discrete_Choices => New_List (Make_Others_Choice (Loc)),
1430 Statements => New_List (
1431 Make_Goto_Statement (Loc,
1432 Name => New_Occurrence_Of (Entity (Label_Id), Loc)))));
1434 -- Generate:
1435 -- <<L0>>
1437 Append_To (Finalizer_Stmts, Label);
1439 -- Create the jump block which controls the finalization flow
1440 -- depending on the value of the state counter.
1442 Jump_Block :=
1443 Make_Case_Statement (Loc,
1444 Expression => Make_Identifier (Loc, Chars (Counter_Id)),
1445 Alternatives => Jump_Alts);
1447 if Acts_As_Clean and then Present (Jump_Block_Insert_Nod) then
1448 Insert_After (Jump_Block_Insert_Nod, Jump_Block);
1449 else
1450 Prepend_To (Finalizer_Stmts, Jump_Block);
1451 end if;
1452 end if;
1454 -- Add the library-level tagged type unregistration machinery before
1455 -- the jump block circuitry. This ensures that external tags will be
1456 -- removed even if a finalization exception occurs at some point.
1458 if Has_Tagged_Types then
1459 Prepend_List_To (Finalizer_Stmts, Tagged_Type_Stmts);
1460 end if;
1462 -- Add a call to the previous At_End handler if it exists. The call
1463 -- must always precede the jump block.
1465 if Present (Prev_At_End) then
1466 Prepend_To (Finalizer_Stmts,
1467 Make_Procedure_Call_Statement (Loc, Prev_At_End));
1469 -- Clear the At_End handler since we have already generated the
1470 -- proper replacement call for it.
1472 Set_At_End_Proc (HSS, Empty);
1473 end if;
1475 -- Release the secondary stack mark
1477 if Present (Mark_Id) then
1478 Append_To (Finalizer_Stmts, Build_SS_Release_Call (Loc, Mark_Id));
1479 end if;
1481 -- Protect the statements with abort defer/undefer. This is only when
1482 -- aborts are allowed and the clean up statements require deferral or
1483 -- there are controlled objects to be finalized.
1485 if Abort_Allowed and then (Defer_Abort or Has_Ctrl_Objs) then
1486 Prepend_To (Finalizer_Stmts,
1487 Make_Procedure_Call_Statement (Loc,
1488 Name => New_Occurrence_Of (RTE (RE_Abort_Defer), Loc)));
1490 Append_To (Finalizer_Stmts,
1491 Make_Procedure_Call_Statement (Loc,
1492 Name => New_Occurrence_Of (RTE (RE_Abort_Undefer), Loc)));
1493 end if;
1495 -- The local exception does not need to be reraised for library-level
1496 -- finalizers. Note that this action must be carried out after object
1497 -- clean up, secondary stack release and abort undeferral. Generate:
1499 -- if Raised and then not Abort then
1500 -- Raise_From_Controlled_Operation (E);
1501 -- end if;
1503 if Has_Ctrl_Objs and Exceptions_OK and not For_Package then
1504 Append_To (Finalizer_Stmts,
1505 Build_Raise_Statement (Finalizer_Data));
1506 end if;
1508 -- Generate:
1509 -- procedure Fin_Id is
1510 -- Abort : constant Boolean := Triggered_By_Abort;
1511 -- <or>
1512 -- Abort : constant Boolean := False; -- no abort
1514 -- E : Exception_Occurrence; -- All added if flag
1515 -- Raised : Boolean := False; -- Has_Ctrl_Objs is set
1516 -- L0 : label;
1517 -- ...
1518 -- Lnn : label;
1520 -- begin
1521 -- Abort_Defer; -- Added if abort is allowed
1522 -- <call to Prev_At_End> -- Added if exists
1523 -- <cleanup statements> -- Added if Acts_As_Clean
1524 -- <jump block> -- Added if Has_Ctrl_Objs
1525 -- <finalization statements> -- Added if Has_Ctrl_Objs
1526 -- <stack release> -- Added if Mark_Id exists
1527 -- Abort_Undefer; -- Added if abort is allowed
1528 -- <exception propagation> -- Added if Has_Ctrl_Objs
1529 -- end Fin_Id;
1531 -- Create the body of the finalizer
1533 Body_Id := Make_Defining_Identifier (Loc, Chars (Fin_Id));
1535 if For_Package then
1536 Set_Has_Qualified_Name (Body_Id);
1537 Set_Has_Fully_Qualified_Name (Body_Id);
1538 end if;
1540 Fin_Body :=
1541 Make_Subprogram_Body (Loc,
1542 Specification =>
1543 Make_Procedure_Specification (Loc,
1544 Defining_Unit_Name => Body_Id),
1545 Declarations => Finalizer_Decls,
1546 Handled_Statement_Sequence =>
1547 Make_Handled_Sequence_Of_Statements (Loc, Finalizer_Stmts));
1549 -- Step 4: Spec and body insertion, analysis
1551 if For_Package then
1553 -- If the package spec has private declarations, the finalizer
1554 -- body must be added to the end of the list in order to have
1555 -- visibility of all private controlled objects.
1557 if For_Package_Spec then
1558 if Present (Priv_Decls) then
1559 Append_To (Priv_Decls, Fin_Spec);
1560 Append_To (Priv_Decls, Fin_Body);
1561 else
1562 Append_To (Decls, Fin_Spec);
1563 Append_To (Decls, Fin_Body);
1564 end if;
1566 -- For package bodies, both the finalizer spec and body are
1567 -- inserted at the end of the package declarations.
1569 else
1570 Append_To (Decls, Fin_Spec);
1571 Append_To (Decls, Fin_Body);
1572 end if;
1574 -- Push the name of the package
1576 Push_Scope (Spec_Id);
1577 Analyze (Fin_Spec);
1578 Analyze (Fin_Body);
1579 Pop_Scope;
1581 -- Non-package case
1583 else
1584 -- Create the spec for the finalizer. The At_End handler must be
1585 -- able to call the body which resides in a nested structure.
1587 -- Generate:
1588 -- declare
1589 -- procedure Fin_Id; -- Spec
1590 -- begin
1591 -- <objects and possibly statements>
1592 -- procedure Fin_Id is ... -- Body
1593 -- <statements>
1594 -- at end
1595 -- Fin_Id; -- At_End handler
1596 -- end;
1598 pragma Assert (Present (Spec_Decls));
1600 Append_To (Spec_Decls, Fin_Spec);
1601 Analyze (Fin_Spec);
1603 -- When the finalizer acts solely as a clean up routine, the body
1604 -- is inserted right after the spec.
1606 if Acts_As_Clean and not Has_Ctrl_Objs then
1607 Insert_After (Fin_Spec, Fin_Body);
1609 -- In all other cases the body is inserted after either:
1611 -- 1) The counter update statement of the last controlled object
1612 -- 2) The last top level nested controlled package
1613 -- 3) The last top level controlled instantiation
1615 else
1616 -- Manually freeze the spec. This is somewhat of a hack because
1617 -- a subprogram is frozen when its body is seen and the freeze
1618 -- node appears right before the body. However, in this case,
1619 -- the spec must be frozen earlier since the At_End handler
1620 -- must be able to call it.
1622 -- declare
1623 -- procedure Fin_Id; -- Spec
1624 -- [Fin_Id] -- Freeze node
1625 -- begin
1626 -- ...
1627 -- at end
1628 -- Fin_Id; -- At_End handler
1629 -- end;
1631 Ensure_Freeze_Node (Fin_Id);
1632 Insert_After (Fin_Spec, Freeze_Node (Fin_Id));
1633 Set_Is_Frozen (Fin_Id);
1635 -- In the case where the last construct to contain a controlled
1636 -- object is either a nested package, an instantiation or a
1637 -- freeze node, the body must be inserted directly after the
1638 -- construct.
1640 if Nkind_In (Last_Top_Level_Ctrl_Construct,
1641 N_Freeze_Entity,
1642 N_Package_Declaration,
1643 N_Package_Body)
1644 then
1645 Finalizer_Insert_Nod := Last_Top_Level_Ctrl_Construct;
1646 end if;
1648 Insert_After (Finalizer_Insert_Nod, Fin_Body);
1649 end if;
1651 Analyze (Fin_Body);
1652 end if;
1653 end Create_Finalizer;
1655 --------------------------
1656 -- Process_Declarations --
1657 --------------------------
1659 procedure Process_Declarations
1660 (Decls : List_Id;
1661 Preprocess : Boolean := False;
1662 Top_Level : Boolean := False)
1664 Decl : Node_Id;
1665 Expr : Node_Id;
1666 Obj_Id : Entity_Id;
1667 Obj_Typ : Entity_Id;
1668 Pack_Id : Entity_Id;
1669 Spec : Node_Id;
1670 Typ : Entity_Id;
1672 Old_Counter_Val : Int;
1673 -- This variable is used to determine whether a nested package or
1674 -- instance contains at least one controlled object.
1676 procedure Processing_Actions
1677 (Has_No_Init : Boolean := False;
1678 Is_Protected : Boolean := False);
1679 -- Depending on the mode of operation of Process_Declarations, either
1680 -- increment the controlled object counter, set the controlled object
1681 -- flag and store the last top level construct or process the current
1682 -- declaration. Flag Has_No_Init is used to propagate scenarios where
1683 -- the current declaration may not have initialization proc(s). Flag
1684 -- Is_Protected should be set when the current declaration denotes a
1685 -- simple protected object.
1687 ------------------------
1688 -- Processing_Actions --
1689 ------------------------
1691 procedure Processing_Actions
1692 (Has_No_Init : Boolean := False;
1693 Is_Protected : Boolean := False)
1695 begin
1696 -- Library-level tagged type
1698 if Nkind (Decl) = N_Full_Type_Declaration then
1699 if Preprocess then
1700 Has_Tagged_Types := True;
1702 if Top_Level and then No (Last_Top_Level_Ctrl_Construct) then
1703 Last_Top_Level_Ctrl_Construct := Decl;
1704 end if;
1706 else
1707 Process_Tagged_Type_Declaration (Decl);
1708 end if;
1710 -- Controlled object declaration
1712 else
1713 if Preprocess then
1714 Counter_Val := Counter_Val + 1;
1715 Has_Ctrl_Objs := True;
1717 if Top_Level and then No (Last_Top_Level_Ctrl_Construct) then
1718 Last_Top_Level_Ctrl_Construct := Decl;
1719 end if;
1721 else
1722 Process_Object_Declaration (Decl, Has_No_Init, Is_Protected);
1723 end if;
1724 end if;
1725 end Processing_Actions;
1727 -- Start of processing for Process_Declarations
1729 begin
1730 if No (Decls) or else Is_Empty_List (Decls) then
1731 return;
1732 end if;
1734 -- Process all declarations in reverse order
1736 Decl := Last_Non_Pragma (Decls);
1737 while Present (Decl) loop
1739 -- Library-level tagged types
1741 if Nkind (Decl) = N_Full_Type_Declaration then
1742 Typ := Defining_Identifier (Decl);
1744 if Is_Tagged_Type (Typ)
1745 and then Is_Library_Level_Entity (Typ)
1746 and then Convention (Typ) = Convention_Ada
1747 and then Present (Access_Disp_Table (Typ))
1748 and then RTE_Available (RE_Register_Tag)
1749 and then not No_Run_Time_Mode
1750 and then not Is_Abstract_Type (Typ)
1751 then
1752 Processing_Actions;
1753 end if;
1755 -- Regular object declarations
1757 elsif Nkind (Decl) = N_Object_Declaration then
1758 Obj_Id := Defining_Identifier (Decl);
1759 Obj_Typ := Base_Type (Etype (Obj_Id));
1760 Expr := Expression (Decl);
1762 -- Bypass any form of processing for objects which have their
1763 -- finalization disabled. This applies only to objects at the
1764 -- library level.
1766 if For_Package and then Finalize_Storage_Only (Obj_Typ) then
1767 null;
1769 -- Transient variables are treated separately in order to
1770 -- minimize the size of the generated code. For details, see
1771 -- Process_Transient_Objects.
1773 elsif Is_Processed_Transient (Obj_Id) then
1774 null;
1776 -- The object is of the form:
1777 -- Obj : Typ [:= Expr];
1779 -- Do not process the incomplete view of a deferred constant.
1780 -- Do not consider tag-to-class-wide conversions.
1782 elsif not Is_Imported (Obj_Id)
1783 and then Needs_Finalization (Obj_Typ)
1784 and then not (Ekind (Obj_Id) = E_Constant
1785 and then not Has_Completion (Obj_Id))
1786 and then not Is_Tag_To_Class_Wide_Conversion (Obj_Id)
1787 then
1788 Processing_Actions;
1790 -- The object is of the form:
1791 -- Obj : Access_Typ := Non_BIP_Function_Call'reference;
1793 -- Obj : Access_Typ :=
1794 -- BIP_Function_Call (BIPalloc => 2, ...)'reference;
1796 elsif Is_Access_Type (Obj_Typ)
1797 and then Needs_Finalization
1798 (Available_View (Designated_Type (Obj_Typ)))
1799 and then Present (Expr)
1800 and then
1801 (Is_Secondary_Stack_BIP_Func_Call (Expr)
1802 or else
1803 (Is_Non_BIP_Func_Call (Expr)
1804 and then not Is_Related_To_Func_Return (Obj_Id)))
1805 then
1806 Processing_Actions (Has_No_Init => True);
1808 -- Processing for "hook" objects generated for controlled
1809 -- transients declared inside an Expression_With_Actions.
1811 elsif Is_Access_Type (Obj_Typ)
1812 and then Present (Status_Flag_Or_Transient_Decl (Obj_Id))
1813 and then Nkind (Status_Flag_Or_Transient_Decl (Obj_Id)) =
1814 N_Object_Declaration
1815 then
1816 Processing_Actions (Has_No_Init => True);
1818 -- Process intermediate results of an if expression with one
1819 -- of the alternatives using a controlled function call.
1821 elsif Is_Access_Type (Obj_Typ)
1822 and then Present (Status_Flag_Or_Transient_Decl (Obj_Id))
1823 and then Nkind (Status_Flag_Or_Transient_Decl (Obj_Id)) =
1824 N_Defining_Identifier
1825 and then Present (Expr)
1826 and then Nkind (Expr) = N_Null
1827 then
1828 Processing_Actions (Has_No_Init => True);
1830 -- Simple protected objects which use type System.Tasking.
1831 -- Protected_Objects.Protection to manage their locks should
1832 -- be treated as controlled since they require manual cleanup.
1833 -- The only exception is illustrated in the following example:
1835 -- package Pkg is
1836 -- type Ctrl is new Controlled ...
1837 -- procedure Finalize (Obj : in out Ctrl);
1838 -- Lib_Obj : Ctrl;
1839 -- end Pkg;
1841 -- package body Pkg is
1842 -- protected Prot is
1843 -- procedure Do_Something (Obj : in out Ctrl);
1844 -- end Prot;
1846 -- protected body Prot is
1847 -- procedure Do_Something (Obj : in out Ctrl) is ...
1848 -- end Prot;
1850 -- procedure Finalize (Obj : in out Ctrl) is
1851 -- begin
1852 -- Prot.Do_Something (Obj);
1853 -- end Finalize;
1854 -- end Pkg;
1856 -- Since for the most part entities in package bodies depend on
1857 -- those in package specs, Prot's lock should be cleaned up
1858 -- first. The subsequent cleanup of the spec finalizes Lib_Obj.
1859 -- This act however attempts to invoke Do_Something and fails
1860 -- because the lock has disappeared.
1862 elsif Ekind (Obj_Id) = E_Variable
1863 and then not In_Library_Level_Package_Body (Obj_Id)
1864 and then (Is_Simple_Protected_Type (Obj_Typ)
1865 or else Has_Simple_Protected_Object (Obj_Typ))
1866 then
1867 Processing_Actions (Is_Protected => True);
1868 end if;
1870 -- Specific cases of object renamings
1872 elsif Nkind (Decl) = N_Object_Renaming_Declaration then
1873 Obj_Id := Defining_Identifier (Decl);
1874 Obj_Typ := Base_Type (Etype (Obj_Id));
1876 -- Bypass any form of processing for objects which have their
1877 -- finalization disabled. This applies only to objects at the
1878 -- library level.
1880 if For_Package and then Finalize_Storage_Only (Obj_Typ) then
1881 null;
1883 -- Return object of a build-in-place function. This case is
1884 -- recognized and marked by the expansion of an extended return
1885 -- statement (see Expand_N_Extended_Return_Statement).
1887 elsif Needs_Finalization (Obj_Typ)
1888 and then Is_Return_Object (Obj_Id)
1889 and then Present (Status_Flag_Or_Transient_Decl (Obj_Id))
1890 then
1891 Processing_Actions (Has_No_Init => True);
1893 -- Detect a case where a source object has been initialized by
1894 -- a controlled function call or another object which was later
1895 -- rewritten as a class-wide conversion of Ada.Tags.Displace.
1897 -- Obj1 : CW_Type := Src_Obj;
1898 -- Obj2 : CW_Type := Function_Call (...);
1900 -- Obj1 : CW_Type renames (... Ada.Tags.Displace (Src_Obj));
1901 -- Tmp : ... := Function_Call (...)'reference;
1902 -- Obj2 : CW_Type renames (... Ada.Tags.Displace (Tmp));
1904 elsif Is_Displacement_Of_Object_Or_Function_Result (Obj_Id) then
1905 Processing_Actions (Has_No_Init => True);
1906 end if;
1908 -- Inspect the freeze node of an access-to-controlled type and
1909 -- look for a delayed finalization master. This case arises when
1910 -- the freeze actions are inserted at a later time than the
1911 -- expansion of the context. Since Build_Finalizer is never called
1912 -- on a single construct twice, the master will be ultimately
1913 -- left out and never finalized. This is also needed for freeze
1914 -- actions of designated types themselves, since in some cases the
1915 -- finalization master is associated with a designated type's
1916 -- freeze node rather than that of the access type (see handling
1917 -- for freeze actions in Build_Finalization_Master).
1919 elsif Nkind (Decl) = N_Freeze_Entity
1920 and then Present (Actions (Decl))
1921 then
1922 Typ := Entity (Decl);
1924 if (Is_Access_Type (Typ)
1925 and then not Is_Access_Subprogram_Type (Typ)
1926 and then Needs_Finalization
1927 (Available_View (Designated_Type (Typ))))
1928 or else (Is_Type (Typ) and then Needs_Finalization (Typ))
1929 then
1930 Old_Counter_Val := Counter_Val;
1932 -- Freeze nodes are considered to be identical to packages
1933 -- and blocks in terms of nesting. The difference is that
1934 -- a finalization master created inside the freeze node is
1935 -- at the same nesting level as the node itself.
1937 Process_Declarations (Actions (Decl), Preprocess);
1939 -- The freeze node contains a finalization master
1941 if Preprocess
1942 and then Top_Level
1943 and then No (Last_Top_Level_Ctrl_Construct)
1944 and then Counter_Val > Old_Counter_Val
1945 then
1946 Last_Top_Level_Ctrl_Construct := Decl;
1947 end if;
1948 end if;
1950 -- Nested package declarations, avoid generics
1952 elsif Nkind (Decl) = N_Package_Declaration then
1953 Spec := Specification (Decl);
1954 Pack_Id := Defining_Unit_Name (Spec);
1956 if Nkind (Pack_Id) = N_Defining_Program_Unit_Name then
1957 Pack_Id := Defining_Identifier (Pack_Id);
1958 end if;
1960 if Ekind (Pack_Id) /= E_Generic_Package then
1961 Old_Counter_Val := Counter_Val;
1962 Process_Declarations
1963 (Private_Declarations (Spec), Preprocess);
1964 Process_Declarations
1965 (Visible_Declarations (Spec), Preprocess);
1967 -- Either the visible or the private declarations contain a
1968 -- controlled object. The nested package declaration is the
1969 -- last such construct.
1971 if Preprocess
1972 and then Top_Level
1973 and then No (Last_Top_Level_Ctrl_Construct)
1974 and then Counter_Val > Old_Counter_Val
1975 then
1976 Last_Top_Level_Ctrl_Construct := Decl;
1977 end if;
1978 end if;
1980 -- Nested package bodies, avoid generics
1982 elsif Nkind (Decl) = N_Package_Body then
1983 Spec := Corresponding_Spec (Decl);
1985 if Ekind (Spec) /= E_Generic_Package then
1986 Old_Counter_Val := Counter_Val;
1987 Process_Declarations (Declarations (Decl), Preprocess);
1989 -- The nested package body is the last construct to contain
1990 -- a controlled object.
1992 if Preprocess
1993 and then Top_Level
1994 and then No (Last_Top_Level_Ctrl_Construct)
1995 and then Counter_Val > Old_Counter_Val
1996 then
1997 Last_Top_Level_Ctrl_Construct := Decl;
1998 end if;
1999 end if;
2001 -- Handle a rare case caused by a controlled transient variable
2002 -- created as part of a record init proc. The variable is wrapped
2003 -- in a block, but the block is not associated with a transient
2004 -- scope.
2006 elsif Nkind (Decl) = N_Block_Statement
2007 and then Inside_Init_Proc
2008 then
2009 Old_Counter_Val := Counter_Val;
2011 if Present (Handled_Statement_Sequence (Decl)) then
2012 Process_Declarations
2013 (Statements (Handled_Statement_Sequence (Decl)),
2014 Preprocess);
2015 end if;
2017 Process_Declarations (Declarations (Decl), Preprocess);
2019 -- Either the declaration or statement list of the block has a
2020 -- controlled object.
2022 if Preprocess
2023 and then Top_Level
2024 and then No (Last_Top_Level_Ctrl_Construct)
2025 and then Counter_Val > Old_Counter_Val
2026 then
2027 Last_Top_Level_Ctrl_Construct := Decl;
2028 end if;
2030 -- Handle the case where the original context has been wrapped in
2031 -- a block to avoid interference between exception handlers and
2032 -- At_End handlers. Treat the block as transparent and process its
2033 -- contents.
2035 elsif Nkind (Decl) = N_Block_Statement
2036 and then Is_Finalization_Wrapper (Decl)
2037 then
2038 if Present (Handled_Statement_Sequence (Decl)) then
2039 Process_Declarations
2040 (Statements (Handled_Statement_Sequence (Decl)),
2041 Preprocess);
2042 end if;
2044 Process_Declarations (Declarations (Decl), Preprocess);
2045 end if;
2047 Prev_Non_Pragma (Decl);
2048 end loop;
2049 end Process_Declarations;
2051 --------------------------------
2052 -- Process_Object_Declaration --
2053 --------------------------------
2055 procedure Process_Object_Declaration
2056 (Decl : Node_Id;
2057 Has_No_Init : Boolean := False;
2058 Is_Protected : Boolean := False)
2060 Loc : constant Source_Ptr := Sloc (Decl);
2061 Obj_Id : constant Entity_Id := Defining_Identifier (Decl);
2063 Init_Typ : Entity_Id;
2064 -- The initialization type of the related object declaration. Note
2065 -- that this is not necessarely the same type as Obj_Typ because of
2066 -- possible type derivations.
2068 Obj_Typ : Entity_Id;
2069 -- The type of the related object declaration
2071 function Build_BIP_Cleanup_Stmts (Func_Id : Entity_Id) return Node_Id;
2072 -- Func_Id denotes a build-in-place function. Generate the following
2073 -- cleanup code:
2075 -- if BIPallocfrom > Secondary_Stack'Pos
2076 -- and then BIPfinalizationmaster /= null
2077 -- then
2078 -- declare
2079 -- type Ptr_Typ is access Obj_Typ;
2080 -- for Ptr_Typ'Storage_Pool
2081 -- use Base_Pool (BIPfinalizationmaster);
2082 -- begin
2083 -- Free (Ptr_Typ (Temp));
2084 -- end;
2085 -- end if;
2087 -- Obj_Typ is the type of the current object, Temp is the original
2088 -- allocation which Obj_Id renames.
2090 procedure Find_Last_Init
2091 (Last_Init : out Node_Id;
2092 Body_Insert : out Node_Id);
2093 -- Find the last initialization call related to object declaration
2094 -- Decl. Last_Init denotes the last initialization call which follows
2095 -- Decl. Body_Insert denotes a node where the finalizer body could be
2096 -- potentially inserted after (if blocks are involved).
2098 -----------------------------
2099 -- Build_BIP_Cleanup_Stmts --
2100 -----------------------------
2102 function Build_BIP_Cleanup_Stmts
2103 (Func_Id : Entity_Id) return Node_Id
2105 Decls : constant List_Id := New_List;
2106 Fin_Mas_Id : constant Entity_Id :=
2107 Build_In_Place_Formal
2108 (Func_Id, BIP_Finalization_Master);
2109 Func_Typ : constant Entity_Id := Etype (Func_Id);
2110 Temp_Id : constant Entity_Id :=
2111 Entity (Prefix (Name (Parent (Obj_Id))));
2113 Cond : Node_Id;
2114 Free_Blk : Node_Id;
2115 Free_Stmt : Node_Id;
2116 Pool_Id : Entity_Id;
2117 Ptr_Typ : Entity_Id;
2119 begin
2120 -- Generate:
2121 -- Pool_Id renames Base_Pool (BIPfinalizationmaster.all).all;
2123 Pool_Id := Make_Temporary (Loc, 'P');
2125 Append_To (Decls,
2126 Make_Object_Renaming_Declaration (Loc,
2127 Defining_Identifier => Pool_Id,
2128 Subtype_Mark =>
2129 New_Occurrence_Of (RTE (RE_Root_Storage_Pool), Loc),
2130 Name =>
2131 Make_Explicit_Dereference (Loc,
2132 Prefix =>
2133 Make_Function_Call (Loc,
2134 Name =>
2135 New_Occurrence_Of (RTE (RE_Base_Pool), Loc),
2136 Parameter_Associations => New_List (
2137 Make_Explicit_Dereference (Loc,
2138 Prefix =>
2139 New_Occurrence_Of (Fin_Mas_Id, Loc)))))));
2141 -- Create an access type which uses the storage pool of the
2142 -- caller's finalization master.
2144 -- Generate:
2145 -- type Ptr_Typ is access Func_Typ;
2147 Ptr_Typ := Make_Temporary (Loc, 'P');
2149 Append_To (Decls,
2150 Make_Full_Type_Declaration (Loc,
2151 Defining_Identifier => Ptr_Typ,
2152 Type_Definition =>
2153 Make_Access_To_Object_Definition (Loc,
2154 Subtype_Indication => New_Occurrence_Of (Func_Typ, Loc))));
2156 -- Perform minor decoration in order to set the master and the
2157 -- storage pool attributes.
2159 Set_Ekind (Ptr_Typ, E_Access_Type);
2160 Set_Finalization_Master (Ptr_Typ, Fin_Mas_Id);
2161 Set_Associated_Storage_Pool (Ptr_Typ, Pool_Id);
2163 -- Create an explicit free statement. Note that the free uses the
2164 -- caller's pool expressed as a renaming.
2166 Free_Stmt :=
2167 Make_Free_Statement (Loc,
2168 Expression =>
2169 Unchecked_Convert_To (Ptr_Typ,
2170 New_Occurrence_Of (Temp_Id, Loc)));
2172 Set_Storage_Pool (Free_Stmt, Pool_Id);
2174 -- Create a block to house the dummy type and the instantiation as
2175 -- well as to perform the cleanup the temporary.
2177 -- Generate:
2178 -- declare
2179 -- <Decls>
2180 -- begin
2181 -- Free (Ptr_Typ (Temp_Id));
2182 -- end;
2184 Free_Blk :=
2185 Make_Block_Statement (Loc,
2186 Declarations => Decls,
2187 Handled_Statement_Sequence =>
2188 Make_Handled_Sequence_Of_Statements (Loc,
2189 Statements => New_List (Free_Stmt)));
2191 -- Generate:
2192 -- if BIPfinalizationmaster /= null then
2194 Cond :=
2195 Make_Op_Ne (Loc,
2196 Left_Opnd => New_Occurrence_Of (Fin_Mas_Id, Loc),
2197 Right_Opnd => Make_Null (Loc));
2199 -- For constrained or tagged results escalate the condition to
2200 -- include the allocation format. Generate:
2202 -- if BIPallocform > Secondary_Stack'Pos
2203 -- and then BIPfinalizationmaster /= null
2204 -- then
2206 if not Is_Constrained (Func_Typ)
2207 or else Is_Tagged_Type (Func_Typ)
2208 then
2209 declare
2210 Alloc : constant Entity_Id :=
2211 Build_In_Place_Formal (Func_Id, BIP_Alloc_Form);
2212 begin
2213 Cond :=
2214 Make_And_Then (Loc,
2215 Left_Opnd =>
2216 Make_Op_Gt (Loc,
2217 Left_Opnd => New_Occurrence_Of (Alloc, Loc),
2218 Right_Opnd =>
2219 Make_Integer_Literal (Loc,
2220 UI_From_Int
2221 (BIP_Allocation_Form'Pos (Secondary_Stack)))),
2223 Right_Opnd => Cond);
2224 end;
2225 end if;
2227 -- Generate:
2228 -- if <Cond> then
2229 -- <Free_Blk>
2230 -- end if;
2232 return
2233 Make_If_Statement (Loc,
2234 Condition => Cond,
2235 Then_Statements => New_List (Free_Blk));
2236 end Build_BIP_Cleanup_Stmts;
2238 --------------------
2239 -- Find_Last_Init --
2240 --------------------
2242 procedure Find_Last_Init
2243 (Last_Init : out Node_Id;
2244 Body_Insert : out Node_Id)
2246 function Find_Last_Init_In_Block (Blk : Node_Id) return Node_Id;
2247 -- Find the last initialization call within the statements of
2248 -- block Blk.
2250 function Is_Init_Call (N : Node_Id) return Boolean;
2251 -- Determine whether node N denotes one of the initialization
2252 -- procedures of types Init_Typ or Obj_Typ.
2254 function Next_Suitable_Statement (Stmt : Node_Id) return Node_Id;
2255 -- Given a statement which is part of a list, return the next
2256 -- statement while skipping over dynamic elab checks.
2258 -----------------------------
2259 -- Find_Last_Init_In_Block --
2260 -----------------------------
2262 function Find_Last_Init_In_Block (Blk : Node_Id) return Node_Id is
2263 HSS : constant Node_Id := Handled_Statement_Sequence (Blk);
2264 Stmt : Node_Id;
2266 begin
2267 -- Examine the individual statements of the block in reverse to
2268 -- locate the last initialization call.
2270 if Present (HSS) and then Present (Statements (HSS)) then
2271 Stmt := Last (Statements (HSS));
2272 while Present (Stmt) loop
2274 -- Peek inside nested blocks in case aborts are allowed
2276 if Nkind (Stmt) = N_Block_Statement then
2277 return Find_Last_Init_In_Block (Stmt);
2279 elsif Is_Init_Call (Stmt) then
2280 return Stmt;
2281 end if;
2283 Prev (Stmt);
2284 end loop;
2285 end if;
2287 return Empty;
2288 end Find_Last_Init_In_Block;
2290 ------------------
2291 -- Is_Init_Call --
2292 ------------------
2294 function Is_Init_Call (N : Node_Id) return Boolean is
2295 function Is_Init_Proc_Of
2296 (Subp_Id : Entity_Id;
2297 Typ : Entity_Id) return Boolean;
2298 -- Determine whether subprogram Subp_Id is a valid init proc of
2299 -- type Typ.
2301 ---------------------
2302 -- Is_Init_Proc_Of --
2303 ---------------------
2305 function Is_Init_Proc_Of
2306 (Subp_Id : Entity_Id;
2307 Typ : Entity_Id) return Boolean
2309 Deep_Init : Entity_Id := Empty;
2310 Prim_Init : Entity_Id := Empty;
2311 Type_Init : Entity_Id := Empty;
2313 begin
2314 -- Obtain all possible initialization routines of the
2315 -- related type and try to match the subprogram entity
2316 -- against one of them.
2318 -- Deep_Initialize
2320 Deep_Init := TSS (Typ, TSS_Deep_Initialize);
2322 -- Primitive Initialize
2324 if Is_Controlled (Typ) then
2325 Prim_Init := Find_Prim_Op (Typ, Name_Initialize);
2327 if Present (Prim_Init) then
2328 Prim_Init := Ultimate_Alias (Prim_Init);
2329 end if;
2330 end if;
2332 -- Type initialization routine
2334 if Has_Non_Null_Base_Init_Proc (Typ) then
2335 Type_Init := Base_Init_Proc (Typ);
2336 end if;
2338 return
2339 (Present (Deep_Init) and then Subp_Id = Deep_Init)
2340 or else
2341 (Present (Prim_Init) and then Subp_Id = Prim_Init)
2342 or else
2343 (Present (Type_Init) and then Subp_Id = Type_Init);
2344 end Is_Init_Proc_Of;
2346 -- Local variables
2348 Call_Id : Entity_Id;
2350 -- Start of processing for Is_Init_Call
2352 begin
2353 if Nkind (N) = N_Procedure_Call_Statement
2354 and then Nkind (Name (N)) = N_Identifier
2355 then
2356 Call_Id := Entity (Name (N));
2358 -- Consider both the type of the object declaration and its
2359 -- related initialization type.
2361 return
2362 Is_Init_Proc_Of (Call_Id, Init_Typ)
2363 or else
2364 Is_Init_Proc_Of (Call_Id, Obj_Typ);
2365 end if;
2367 return False;
2368 end Is_Init_Call;
2370 -----------------------------
2371 -- Next_Suitable_Statement --
2372 -----------------------------
2374 function Next_Suitable_Statement (Stmt : Node_Id) return Node_Id is
2375 Result : Node_Id := Next (Stmt);
2377 begin
2378 -- Skip over access-before-elaboration checks
2380 if Dynamic_Elaboration_Checks
2381 and then Nkind (Result) = N_Raise_Program_Error
2382 then
2383 Result := Next (Result);
2384 end if;
2386 return Result;
2387 end Next_Suitable_Statement;
2389 -- Local variables
2391 Call : Node_Id;
2392 Stmt : Node_Id;
2393 Stmt_2 : Node_Id;
2395 Deep_Init_Found : Boolean := False;
2396 -- A flag set when a call to [Deep_]Initialize has been found
2398 -- Start of processing for Find_Last_Init
2400 begin
2401 Last_Init := Decl;
2402 Body_Insert := Empty;
2404 -- Object renamings and objects associated with controlled
2405 -- function results do not require initialization.
2407 if Has_No_Init then
2408 return;
2409 end if;
2411 Stmt := Next_Suitable_Statement (Decl);
2413 -- A limited controlled object initialized by a function call uses
2414 -- the build-in-place machinery to obtain its value.
2416 -- Obj : Lim_Controlled_Type := Func_Call;
2418 -- is expanded into
2420 -- Obj : Lim_Controlled_Type;
2421 -- type Ptr_Typ is access Lim_Controlled_Type;
2422 -- Temp : constant Ptr_Typ :=
2423 -- Func_Call
2424 -- (BIPalloc => 1,
2425 -- BIPaccess => Obj'Unrestricted_Access)'reference;
2427 -- In this scenario the declaration of the temporary acts as the
2428 -- last initialization statement.
2430 if Is_Limited_Type (Obj_Typ)
2431 and then Has_Init_Expression (Decl)
2432 and then No (Expression (Decl))
2433 then
2434 while Present (Stmt) loop
2435 if Nkind (Stmt) = N_Object_Declaration
2436 and then Present (Expression (Stmt))
2437 and then Is_Object_Access_BIP_Func_Call
2438 (Expr => Expression (Stmt),
2439 Obj_Id => Obj_Id)
2440 then
2441 Last_Init := Stmt;
2442 exit;
2443 end if;
2445 Next (Stmt);
2446 end loop;
2448 -- Nothing to do for an object with supporessed initialization.
2449 -- Note that this check is not performed at the beginning of the
2450 -- routine because a declaration marked with No_Initialization
2451 -- may still be initialized by a build-in-place call (the case
2452 -- above).
2454 elsif No_Initialization (Decl) then
2455 return;
2457 -- In all other cases the initialization calls follow the related
2458 -- object. The general structure of object initialization built by
2459 -- routine Default_Initialize_Object is as follows:
2461 -- [begin -- aborts allowed
2462 -- Abort_Defer;]
2463 -- Type_Init_Proc (Obj);
2464 -- [begin] -- exceptions allowed
2465 -- Deep_Initialize (Obj);
2466 -- [exception -- exceptions allowed
2467 -- when others =>
2468 -- Deep_Finalize (Obj, Self => False);
2469 -- raise;
2470 -- end;]
2471 -- [at end -- aborts allowed
2472 -- Abort_Undefer;
2473 -- end;]
2475 -- When aborts are allowed, the initialization calls are housed
2476 -- within a block.
2478 elsif Nkind (Stmt) = N_Block_Statement then
2479 Last_Init := Find_Last_Init_In_Block (Stmt);
2480 Body_Insert := Stmt;
2482 -- Otherwise the initialization calls follow the related object
2484 else
2485 Stmt_2 := Next_Suitable_Statement (Stmt);
2487 -- Check for an optional call to Deep_Initialize which may
2488 -- appear within a block depending on whether the object has
2489 -- controlled components.
2491 if Present (Stmt_2) then
2492 if Nkind (Stmt_2) = N_Block_Statement then
2493 Call := Find_Last_Init_In_Block (Stmt_2);
2495 if Present (Call) then
2496 Deep_Init_Found := True;
2497 Last_Init := Call;
2498 Body_Insert := Stmt_2;
2499 end if;
2501 elsif Is_Init_Call (Stmt_2) then
2502 Deep_Init_Found := True;
2503 Last_Init := Stmt_2;
2504 Body_Insert := Last_Init;
2505 end if;
2506 end if;
2508 -- If the object lacks a call to Deep_Initialize, then it must
2509 -- have a call to its related type init proc.
2511 if not Deep_Init_Found and then Is_Init_Call (Stmt) then
2512 Last_Init := Stmt;
2513 Body_Insert := Last_Init;
2514 end if;
2515 end if;
2516 end Find_Last_Init;
2518 -- Local variables
2520 Body_Ins : Node_Id;
2521 Count_Ins : Node_Id;
2522 Fin_Call : Node_Id;
2523 Fin_Stmts : List_Id;
2524 Inc_Decl : Node_Id;
2525 Label : Node_Id;
2526 Label_Id : Entity_Id;
2527 Obj_Ref : Node_Id;
2529 -- Start of processing for Process_Object_Declaration
2531 begin
2532 -- Handle the object type and the reference to the object
2534 Obj_Ref := New_Occurrence_Of (Obj_Id, Loc);
2535 Obj_Typ := Base_Type (Etype (Obj_Id));
2537 loop
2538 if Is_Access_Type (Obj_Typ) then
2539 Obj_Typ := Directly_Designated_Type (Obj_Typ);
2540 Obj_Ref := Make_Explicit_Dereference (Loc, Obj_Ref);
2542 elsif Is_Concurrent_Type (Obj_Typ)
2543 and then Present (Corresponding_Record_Type (Obj_Typ))
2544 then
2545 Obj_Typ := Corresponding_Record_Type (Obj_Typ);
2546 Obj_Ref := Unchecked_Convert_To (Obj_Typ, Obj_Ref);
2548 elsif Is_Private_Type (Obj_Typ)
2549 and then Present (Full_View (Obj_Typ))
2550 then
2551 Obj_Typ := Full_View (Obj_Typ);
2552 Obj_Ref := Unchecked_Convert_To (Obj_Typ, Obj_Ref);
2554 elsif Obj_Typ /= Base_Type (Obj_Typ) then
2555 Obj_Typ := Base_Type (Obj_Typ);
2556 Obj_Ref := Unchecked_Convert_To (Obj_Typ, Obj_Ref);
2558 else
2559 exit;
2560 end if;
2561 end loop;
2563 Set_Etype (Obj_Ref, Obj_Typ);
2565 -- Handle the initialization type of the object declaration
2567 Init_Typ := Obj_Typ;
2568 loop
2569 if Is_Private_Type (Init_Typ)
2570 and then Present (Full_View (Init_Typ))
2571 then
2572 Init_Typ := Full_View (Init_Typ);
2574 elsif Is_Untagged_Derivation (Init_Typ) then
2575 Init_Typ := Root_Type (Init_Typ);
2577 else
2578 exit;
2579 end if;
2580 end loop;
2582 -- Set a new value for the state counter and insert the statement
2583 -- after the object declaration. Generate:
2585 -- Counter := <value>;
2587 Inc_Decl :=
2588 Make_Assignment_Statement (Loc,
2589 Name => New_Occurrence_Of (Counter_Id, Loc),
2590 Expression => Make_Integer_Literal (Loc, Counter_Val));
2592 -- Insert the counter after all initialization has been done. The
2593 -- place of insertion depends on the context. If an object is being
2594 -- initialized via an aggregate, then the counter must be inserted
2595 -- after the last aggregate assignment.
2597 if Ekind_In (Obj_Id, E_Constant, E_Variable)
2598 and then Present (Last_Aggregate_Assignment (Obj_Id))
2599 then
2600 Count_Ins := Last_Aggregate_Assignment (Obj_Id);
2601 Body_Ins := Empty;
2603 -- In all other cases the counter is inserted after the last call to
2604 -- either [Deep_]Initialize or the type specific init proc.
2606 else
2607 Find_Last_Init (Count_Ins, Body_Ins);
2608 end if;
2610 Insert_After (Count_Ins, Inc_Decl);
2611 Analyze (Inc_Decl);
2613 -- If the current declaration is the last in the list, the finalizer
2614 -- body needs to be inserted after the set counter statement for the
2615 -- current object declaration. This is complicated by the fact that
2616 -- the set counter statement may appear in abort deferred block. In
2617 -- that case, the proper insertion place is after the block.
2619 if No (Finalizer_Insert_Nod) then
2621 -- Insertion after an abort deffered block
2623 if Present (Body_Ins) then
2624 Finalizer_Insert_Nod := Body_Ins;
2625 else
2626 Finalizer_Insert_Nod := Inc_Decl;
2627 end if;
2628 end if;
2630 -- Create the associated label with this object, generate:
2632 -- L<counter> : label;
2634 Label_Id :=
2635 Make_Identifier (Loc, New_External_Name ('L', Counter_Val));
2636 Set_Entity
2637 (Label_Id, Make_Defining_Identifier (Loc, Chars (Label_Id)));
2638 Label := Make_Label (Loc, Label_Id);
2640 Prepend_To (Finalizer_Decls,
2641 Make_Implicit_Label_Declaration (Loc,
2642 Defining_Identifier => Entity (Label_Id),
2643 Label_Construct => Label));
2645 -- Create the associated jump with this object, generate:
2647 -- when <counter> =>
2648 -- goto L<counter>;
2650 Prepend_To (Jump_Alts,
2651 Make_Case_Statement_Alternative (Loc,
2652 Discrete_Choices => New_List (
2653 Make_Integer_Literal (Loc, Counter_Val)),
2654 Statements => New_List (
2655 Make_Goto_Statement (Loc,
2656 Name => New_Occurrence_Of (Entity (Label_Id), Loc)))));
2658 -- Insert the jump destination, generate:
2660 -- <<L<counter>>>
2662 Append_To (Finalizer_Stmts, Label);
2664 -- Processing for simple protected objects. Such objects require
2665 -- manual finalization of their lock managers.
2667 if Is_Protected then
2668 Fin_Stmts := No_List;
2670 if Is_Simple_Protected_Type (Obj_Typ) then
2671 Fin_Call := Cleanup_Protected_Object (Decl, Obj_Ref);
2673 if Present (Fin_Call) then
2674 Fin_Stmts := New_List (Fin_Call);
2675 end if;
2677 elsif Has_Simple_Protected_Object (Obj_Typ) then
2678 if Is_Record_Type (Obj_Typ) then
2679 Fin_Stmts := Cleanup_Record (Decl, Obj_Ref, Obj_Typ);
2680 elsif Is_Array_Type (Obj_Typ) then
2681 Fin_Stmts := Cleanup_Array (Decl, Obj_Ref, Obj_Typ);
2682 end if;
2683 end if;
2685 -- Generate:
2686 -- begin
2687 -- System.Tasking.Protected_Objects.Finalize_Protection
2688 -- (Obj._object);
2690 -- exception
2691 -- when others =>
2692 -- null;
2693 -- end;
2695 if Present (Fin_Stmts) then
2696 Append_To (Finalizer_Stmts,
2697 Make_Block_Statement (Loc,
2698 Handled_Statement_Sequence =>
2699 Make_Handled_Sequence_Of_Statements (Loc,
2700 Statements => Fin_Stmts,
2702 Exception_Handlers => New_List (
2703 Make_Exception_Handler (Loc,
2704 Exception_Choices => New_List (
2705 Make_Others_Choice (Loc)),
2707 Statements => New_List (
2708 Make_Null_Statement (Loc)))))));
2709 end if;
2711 -- Processing for regular controlled objects
2713 else
2714 -- Generate:
2715 -- [Deep_]Finalize (Obj); -- No_Exception_Propagation
2717 -- begin -- Exception handlers allowed
2718 -- [Deep_]Finalize (Obj);
2720 -- exception
2721 -- when Id : others =>
2722 -- if not Raised then
2723 -- Raised := True;
2724 -- Save_Occurrence (E, Id);
2725 -- end if;
2726 -- end;
2728 Fin_Call :=
2729 Make_Final_Call (
2730 Obj_Ref => Obj_Ref,
2731 Typ => Obj_Typ);
2733 -- For CodePeer, the exception handlers normally generated here
2734 -- generate complex flowgraphs which result in capacity problems.
2735 -- Omitting these handlers for CodePeer is justified as follows:
2737 -- If a handler is dead, then omitting it is surely ok
2739 -- If a handler is live, then CodePeer should flag the
2740 -- potentially-exception-raising construct that causes it
2741 -- to be live. That is what we are interested in, not what
2742 -- happens after the exception is raised.
2744 if Exceptions_OK and not CodePeer_Mode then
2745 Fin_Stmts := New_List (
2746 Make_Block_Statement (Loc,
2747 Handled_Statement_Sequence =>
2748 Make_Handled_Sequence_Of_Statements (Loc,
2749 Statements => New_List (Fin_Call),
2751 Exception_Handlers => New_List (
2752 Build_Exception_Handler
2753 (Finalizer_Data, For_Package)))));
2755 -- When exception handlers are prohibited, the finalization call
2756 -- appears unprotected. Any exception raised during finalization
2757 -- will bypass the circuitry which ensures the cleanup of all
2758 -- remaining objects.
2760 else
2761 Fin_Stmts := New_List (Fin_Call);
2762 end if;
2764 -- If we are dealing with a return object of a build-in-place
2765 -- function, generate the following cleanup statements:
2767 -- if BIPallocfrom > Secondary_Stack'Pos
2768 -- and then BIPfinalizationmaster /= null
2769 -- then
2770 -- declare
2771 -- type Ptr_Typ is access Obj_Typ;
2772 -- for Ptr_Typ'Storage_Pool use
2773 -- Base_Pool (BIPfinalizationmaster.all).all;
2774 -- begin
2775 -- Free (Ptr_Typ (Temp));
2776 -- end;
2777 -- end if;
2779 -- The generated code effectively detaches the temporary from the
2780 -- caller finalization master and deallocates the object. This is
2781 -- disabled on .NET/JVM because pools are not supported.
2783 if VM_Target = No_VM and then Is_Return_Object (Obj_Id) then
2784 declare
2785 Func_Id : constant Entity_Id := Enclosing_Function (Obj_Id);
2786 begin
2787 if Is_Build_In_Place_Function (Func_Id)
2788 and then Needs_BIP_Finalization_Master (Func_Id)
2789 then
2790 Append_To (Fin_Stmts, Build_BIP_Cleanup_Stmts (Func_Id));
2791 end if;
2792 end;
2793 end if;
2795 if Ekind_In (Obj_Id, E_Constant, E_Variable)
2796 and then Present (Status_Flag_Or_Transient_Decl (Obj_Id))
2797 then
2798 -- Temporaries created for the purpose of "exporting" a
2799 -- controlled transient out of an Expression_With_Actions (EWA)
2800 -- need guards. The following illustrates the usage of such
2801 -- temporaries.
2803 -- Access_Typ : access [all] Obj_Typ;
2804 -- Temp : Access_Typ := null;
2805 -- <Counter> := ...;
2807 -- do
2808 -- Ctrl_Trans : [access [all]] Obj_Typ := ...;
2809 -- Temp := Access_Typ (Ctrl_Trans); -- when a pointer
2810 -- <or>
2811 -- Temp := Ctrl_Trans'Unchecked_Access;
2812 -- in ... end;
2814 -- The finalization machinery does not process EWA nodes as
2815 -- this may lead to premature finalization of expressions. Note
2816 -- that Temp is marked as being properly initialized regardless
2817 -- of whether the initialization of Ctrl_Trans succeeded. Since
2818 -- a failed initialization may leave Temp with a value of null,
2819 -- add a guard to handle this case:
2821 -- if Obj /= null then
2822 -- <object finalization statements>
2823 -- end if;
2825 if Nkind (Status_Flag_Or_Transient_Decl (Obj_Id)) =
2826 N_Object_Declaration
2827 then
2828 Fin_Stmts := New_List (
2829 Make_If_Statement (Loc,
2830 Condition =>
2831 Make_Op_Ne (Loc,
2832 Left_Opnd => New_Occurrence_Of (Obj_Id, Loc),
2833 Right_Opnd => Make_Null (Loc)),
2834 Then_Statements => Fin_Stmts));
2836 -- Return objects use a flag to aid in processing their
2837 -- potential finalization when the enclosing function fails
2838 -- to return properly. Generate:
2840 -- if not Flag then
2841 -- <object finalization statements>
2842 -- end if;
2844 else
2845 Fin_Stmts := New_List (
2846 Make_If_Statement (Loc,
2847 Condition =>
2848 Make_Op_Not (Loc,
2849 Right_Opnd =>
2850 New_Occurrence_Of
2851 (Status_Flag_Or_Transient_Decl (Obj_Id), Loc)),
2853 Then_Statements => Fin_Stmts));
2854 end if;
2855 end if;
2856 end if;
2858 Append_List_To (Finalizer_Stmts, Fin_Stmts);
2860 -- Since the declarations are examined in reverse, the state counter
2861 -- must be decremented in order to keep with the true position of
2862 -- objects.
2864 Counter_Val := Counter_Val - 1;
2865 end Process_Object_Declaration;
2867 -------------------------------------
2868 -- Process_Tagged_Type_Declaration --
2869 -------------------------------------
2871 procedure Process_Tagged_Type_Declaration (Decl : Node_Id) is
2872 Typ : constant Entity_Id := Defining_Identifier (Decl);
2873 DT_Ptr : constant Entity_Id :=
2874 Node (First_Elmt (Access_Disp_Table (Typ)));
2875 begin
2876 -- Generate:
2877 -- Ada.Tags.Unregister_Tag (<Typ>P);
2879 Append_To (Tagged_Type_Stmts,
2880 Make_Procedure_Call_Statement (Loc,
2881 Name =>
2882 New_Occurrence_Of (RTE (RE_Unregister_Tag), Loc),
2883 Parameter_Associations => New_List (
2884 New_Occurrence_Of (DT_Ptr, Loc))));
2885 end Process_Tagged_Type_Declaration;
2887 -- Start of processing for Build_Finalizer
2889 begin
2890 Fin_Id := Empty;
2892 -- Do not perform this expansion in SPARK mode because it is not
2893 -- necessary.
2895 if GNATprove_Mode then
2896 return;
2897 end if;
2899 -- Step 1: Extract all lists which may contain controlled objects or
2900 -- library-level tagged types.
2902 if For_Package_Spec then
2903 Decls := Visible_Declarations (Specification (N));
2904 Priv_Decls := Private_Declarations (Specification (N));
2906 -- Retrieve the package spec id
2908 Spec_Id := Defining_Unit_Name (Specification (N));
2910 if Nkind (Spec_Id) = N_Defining_Program_Unit_Name then
2911 Spec_Id := Defining_Identifier (Spec_Id);
2912 end if;
2914 -- Accept statement, block, entry body, package body, protected body,
2915 -- subprogram body or task body.
2917 else
2918 Decls := Declarations (N);
2919 HSS := Handled_Statement_Sequence (N);
2921 if Present (HSS) then
2922 if Present (Statements (HSS)) then
2923 Stmts := Statements (HSS);
2924 end if;
2926 if Present (At_End_Proc (HSS)) then
2927 Prev_At_End := At_End_Proc (HSS);
2928 end if;
2929 end if;
2931 -- Retrieve the package spec id for package bodies
2933 if For_Package_Body then
2934 Spec_Id := Corresponding_Spec (N);
2935 end if;
2936 end if;
2938 -- Do not process nested packages since those are handled by the
2939 -- enclosing scope's finalizer. Do not process non-expanded package
2940 -- instantiations since those will be re-analyzed and re-expanded.
2942 if For_Package
2943 and then
2944 (not Is_Library_Level_Entity (Spec_Id)
2946 -- Nested packages are considered to be library level entities,
2947 -- but do not need to be processed separately. True library level
2948 -- packages have a scope value of 1.
2950 or else Scope_Depth_Value (Spec_Id) /= Uint_1
2951 or else (Is_Generic_Instance (Spec_Id)
2952 and then Package_Instantiation (Spec_Id) /= N))
2953 then
2954 return;
2955 end if;
2957 -- Step 2: Object [pre]processing
2959 if For_Package then
2961 -- Preprocess the visible declarations now in order to obtain the
2962 -- correct number of controlled object by the time the private
2963 -- declarations are processed.
2965 Process_Declarations (Decls, Preprocess => True, Top_Level => True);
2967 -- From all the possible contexts, only package specifications may
2968 -- have private declarations.
2970 if For_Package_Spec then
2971 Process_Declarations
2972 (Priv_Decls, Preprocess => True, Top_Level => True);
2973 end if;
2975 -- The current context may lack controlled objects, but require some
2976 -- other form of completion (task termination for instance). In such
2977 -- cases, the finalizer must be created and carry the additional
2978 -- statements.
2980 if Acts_As_Clean or Has_Ctrl_Objs or Has_Tagged_Types then
2981 Build_Components;
2982 end if;
2984 -- The preprocessing has determined that the context has controlled
2985 -- objects or library-level tagged types.
2987 if Has_Ctrl_Objs or Has_Tagged_Types then
2989 -- Private declarations are processed first in order to preserve
2990 -- possible dependencies between public and private objects.
2992 if For_Package_Spec then
2993 Process_Declarations (Priv_Decls);
2994 end if;
2996 Process_Declarations (Decls);
2997 end if;
2999 -- Non-package case
3001 else
3002 -- Preprocess both declarations and statements
3004 Process_Declarations (Decls, Preprocess => True, Top_Level => True);
3005 Process_Declarations (Stmts, Preprocess => True, Top_Level => True);
3007 -- At this point it is known that N has controlled objects. Ensure
3008 -- that N has a declarative list since the finalizer spec will be
3009 -- attached to it.
3011 if Has_Ctrl_Objs and then No (Decls) then
3012 Set_Declarations (N, New_List);
3013 Decls := Declarations (N);
3014 Spec_Decls := Decls;
3015 end if;
3017 -- The current context may lack controlled objects, but require some
3018 -- other form of completion (task termination for instance). In such
3019 -- cases, the finalizer must be created and carry the additional
3020 -- statements.
3022 if Acts_As_Clean or Has_Ctrl_Objs or Has_Tagged_Types then
3023 Build_Components;
3024 end if;
3026 if Has_Ctrl_Objs or Has_Tagged_Types then
3027 Process_Declarations (Stmts);
3028 Process_Declarations (Decls);
3029 end if;
3030 end if;
3032 -- Step 3: Finalizer creation
3034 if Acts_As_Clean or Has_Ctrl_Objs or Has_Tagged_Types then
3035 Create_Finalizer;
3036 end if;
3037 end Build_Finalizer;
3039 --------------------------
3040 -- Build_Finalizer_Call --
3041 --------------------------
3043 procedure Build_Finalizer_Call (N : Node_Id; Fin_Id : Entity_Id) is
3044 Is_Prot_Body : constant Boolean :=
3045 Nkind (N) = N_Subprogram_Body
3046 and then Is_Protected_Subprogram_Body (N);
3047 -- Determine whether N denotes the protected version of a subprogram
3048 -- which belongs to a protected type.
3050 Loc : constant Source_Ptr := Sloc (N);
3051 HSS : Node_Id;
3053 begin
3054 -- Do not perform this expansion in SPARK mode because we do not create
3055 -- finalizers in the first place.
3057 if GNATprove_Mode then
3058 return;
3059 end if;
3061 -- The At_End handler should have been assimilated by the finalizer
3063 HSS := Handled_Statement_Sequence (N);
3064 pragma Assert (No (At_End_Proc (HSS)));
3066 -- If the construct to be cleaned up is a protected subprogram body, the
3067 -- finalizer call needs to be associated with the block which wraps the
3068 -- unprotected version of the subprogram. The following illustrates this
3069 -- scenario:
3071 -- procedure Prot_SubpP is
3072 -- procedure finalizer is
3073 -- begin
3074 -- Service_Entries (Prot_Obj);
3075 -- Abort_Undefer;
3076 -- end finalizer;
3078 -- begin
3079 -- . . .
3080 -- begin
3081 -- Prot_SubpN (Prot_Obj);
3082 -- at end
3083 -- finalizer;
3084 -- end;
3085 -- end Prot_SubpP;
3087 if Is_Prot_Body then
3088 HSS := Handled_Statement_Sequence (Last (Statements (HSS)));
3090 -- An At_End handler and regular exception handlers cannot coexist in
3091 -- the same statement sequence. Wrap the original statements in a block.
3093 elsif Present (Exception_Handlers (HSS)) then
3094 declare
3095 End_Lab : constant Node_Id := End_Label (HSS);
3096 Block : Node_Id;
3098 begin
3099 Block :=
3100 Make_Block_Statement (Loc, Handled_Statement_Sequence => HSS);
3102 Set_Handled_Statement_Sequence (N,
3103 Make_Handled_Sequence_Of_Statements (Loc, New_List (Block)));
3105 HSS := Handled_Statement_Sequence (N);
3106 Set_End_Label (HSS, End_Lab);
3107 end;
3108 end if;
3110 Set_At_End_Proc (HSS, New_Occurrence_Of (Fin_Id, Loc));
3112 Analyze (At_End_Proc (HSS));
3113 Expand_At_End_Handler (HSS, Empty);
3114 end Build_Finalizer_Call;
3116 ---------------------
3117 -- Build_Late_Proc --
3118 ---------------------
3120 procedure Build_Late_Proc (Typ : Entity_Id; Nam : Name_Id) is
3121 begin
3122 for Final_Prim in Name_Of'Range loop
3123 if Name_Of (Final_Prim) = Nam then
3124 Set_TSS (Typ,
3125 Make_Deep_Proc
3126 (Prim => Final_Prim,
3127 Typ => Typ,
3128 Stmts => Make_Deep_Record_Body (Final_Prim, Typ)));
3129 end if;
3130 end loop;
3131 end Build_Late_Proc;
3133 -------------------------------
3134 -- Build_Object_Declarations --
3135 -------------------------------
3137 procedure Build_Object_Declarations
3138 (Data : out Finalization_Exception_Data;
3139 Decls : List_Id;
3140 Loc : Source_Ptr;
3141 For_Package : Boolean := False)
3143 Decl : Node_Id;
3145 Dummy : Entity_Id;
3146 -- This variable captures an unused dummy internal entity, see the
3147 -- comment associated with its use.
3149 begin
3150 pragma Assert (Decls /= No_List);
3152 -- Always set the proper location as it may be needed even when
3153 -- exception propagation is forbidden.
3155 Data.Loc := Loc;
3157 if Restriction_Active (No_Exception_Propagation) then
3158 Data.Abort_Id := Empty;
3159 Data.E_Id := Empty;
3160 Data.Raised_Id := Empty;
3161 return;
3162 end if;
3164 Data.Raised_Id := Make_Temporary (Loc, 'R');
3166 -- In certain scenarios, finalization can be triggered by an abort. If
3167 -- the finalization itself fails and raises an exception, the resulting
3168 -- Program_Error must be supressed and replaced by an abort signal. In
3169 -- order to detect this scenario, save the state of entry into the
3170 -- finalization code.
3172 -- No need to do this for VM case, since VM version of Ada.Exceptions
3173 -- does not include routine Raise_From_Controlled_Operation which is the
3174 -- the sole user of flag Abort.
3176 -- This is not needed for library-level finalizers as they are called by
3177 -- the environment task and cannot be aborted.
3179 if VM_Target = No_VM and then not For_Package then
3180 if Abort_Allowed then
3181 Data.Abort_Id := Make_Temporary (Loc, 'A');
3183 -- Generate:
3184 -- Abort_Id : constant Boolean := <A_Expr>;
3186 Append_To (Decls,
3187 Make_Object_Declaration (Loc,
3188 Defining_Identifier => Data.Abort_Id,
3189 Constant_Present => True,
3190 Object_Definition =>
3191 New_Occurrence_Of (Standard_Boolean, Loc),
3192 Expression =>
3193 New_Occurrence_Of (RTE (RE_Triggered_By_Abort), Loc)));
3195 -- Abort is not required
3197 else
3198 -- Generate a dummy entity to ensure that the internal symbols are
3199 -- in sync when a unit is compiled with and without aborts.
3201 Dummy := Make_Temporary (Loc, 'A');
3202 Data.Abort_Id := Empty;
3203 end if;
3205 -- .NET/JVM or library-level finalizers
3207 else
3208 Data.Abort_Id := Empty;
3209 end if;
3211 if Exception_Extra_Info then
3212 Data.E_Id := Make_Temporary (Loc, 'E');
3214 -- Generate:
3215 -- E_Id : Exception_Occurrence;
3217 Decl :=
3218 Make_Object_Declaration (Loc,
3219 Defining_Identifier => Data.E_Id,
3220 Object_Definition =>
3221 New_Occurrence_Of (RTE (RE_Exception_Occurrence), Loc));
3222 Set_No_Initialization (Decl);
3224 Append_To (Decls, Decl);
3226 else
3227 Data.E_Id := Empty;
3228 end if;
3230 -- Generate:
3231 -- Raised_Id : Boolean := False;
3233 Append_To (Decls,
3234 Make_Object_Declaration (Loc,
3235 Defining_Identifier => Data.Raised_Id,
3236 Object_Definition => New_Occurrence_Of (Standard_Boolean, Loc),
3237 Expression => New_Occurrence_Of (Standard_False, Loc)));
3238 end Build_Object_Declarations;
3240 ---------------------------
3241 -- Build_Raise_Statement --
3242 ---------------------------
3244 function Build_Raise_Statement
3245 (Data : Finalization_Exception_Data) return Node_Id
3247 Stmt : Node_Id;
3248 Expr : Node_Id;
3250 begin
3251 -- Standard run-time and .NET/JVM targets use the specialized routine
3252 -- Raise_From_Controlled_Operation.
3254 if Exception_Extra_Info
3255 and then RTE_Available (RE_Raise_From_Controlled_Operation)
3256 then
3257 Stmt :=
3258 Make_Procedure_Call_Statement (Data.Loc,
3259 Name =>
3260 New_Occurrence_Of
3261 (RTE (RE_Raise_From_Controlled_Operation), Data.Loc),
3262 Parameter_Associations =>
3263 New_List (New_Occurrence_Of (Data.E_Id, Data.Loc)));
3265 -- Restricted run-time: exception messages are not supported and hence
3266 -- Raise_From_Controlled_Operation is not supported. Raise Program_Error
3267 -- instead.
3269 else
3270 Stmt :=
3271 Make_Raise_Program_Error (Data.Loc,
3272 Reason => PE_Finalize_Raised_Exception);
3273 end if;
3275 -- Generate:
3277 -- Raised_Id and then not Abort_Id
3278 -- <or>
3279 -- Raised_Id
3281 Expr := New_Occurrence_Of (Data.Raised_Id, Data.Loc);
3283 if Present (Data.Abort_Id) then
3284 Expr := Make_And_Then (Data.Loc,
3285 Left_Opnd => Expr,
3286 Right_Opnd =>
3287 Make_Op_Not (Data.Loc,
3288 Right_Opnd => New_Occurrence_Of (Data.Abort_Id, Data.Loc)));
3289 end if;
3291 -- Generate:
3293 -- if Raised_Id and then not Abort_Id then
3294 -- Raise_From_Controlled_Operation (E_Id);
3295 -- <or>
3296 -- raise Program_Error; -- restricted runtime
3297 -- end if;
3299 return
3300 Make_If_Statement (Data.Loc,
3301 Condition => Expr,
3302 Then_Statements => New_List (Stmt));
3303 end Build_Raise_Statement;
3305 -----------------------------
3306 -- Build_Record_Deep_Procs --
3307 -----------------------------
3309 procedure Build_Record_Deep_Procs (Typ : Entity_Id) is
3310 begin
3311 Set_TSS (Typ,
3312 Make_Deep_Proc
3313 (Prim => Initialize_Case,
3314 Typ => Typ,
3315 Stmts => Make_Deep_Record_Body (Initialize_Case, Typ)));
3317 if not Is_Limited_View (Typ) then
3318 Set_TSS (Typ,
3319 Make_Deep_Proc
3320 (Prim => Adjust_Case,
3321 Typ => Typ,
3322 Stmts => Make_Deep_Record_Body (Adjust_Case, Typ)));
3323 end if;
3325 -- Do not generate Deep_Finalize and Finalize_Address if finalization is
3326 -- suppressed since these routine will not be used.
3328 if not Restriction_Active (No_Finalization) then
3329 Set_TSS (Typ,
3330 Make_Deep_Proc
3331 (Prim => Finalize_Case,
3332 Typ => Typ,
3333 Stmts => Make_Deep_Record_Body (Finalize_Case, Typ)));
3335 -- Create TSS primitive Finalize_Address for non-VM targets. JVM and
3336 -- .NET do not support address arithmetic and unchecked conversions.
3338 if VM_Target = No_VM then
3339 Set_TSS (Typ,
3340 Make_Deep_Proc
3341 (Prim => Address_Case,
3342 Typ => Typ,
3343 Stmts => Make_Deep_Record_Body (Address_Case, Typ)));
3344 end if;
3345 end if;
3346 end Build_Record_Deep_Procs;
3348 -------------------
3349 -- Cleanup_Array --
3350 -------------------
3352 function Cleanup_Array
3353 (N : Node_Id;
3354 Obj : Node_Id;
3355 Typ : Entity_Id) return List_Id
3357 Loc : constant Source_Ptr := Sloc (N);
3358 Index_List : constant List_Id := New_List;
3360 function Free_Component return List_Id;
3361 -- Generate the code to finalize the task or protected subcomponents
3362 -- of a single component of the array.
3364 function Free_One_Dimension (Dim : Int) return List_Id;
3365 -- Generate a loop over one dimension of the array
3367 --------------------
3368 -- Free_Component --
3369 --------------------
3371 function Free_Component return List_Id is
3372 Stmts : List_Id := New_List;
3373 Tsk : Node_Id;
3374 C_Typ : constant Entity_Id := Component_Type (Typ);
3376 begin
3377 -- Component type is known to contain tasks or protected objects
3379 Tsk :=
3380 Make_Indexed_Component (Loc,
3381 Prefix => Duplicate_Subexpr_No_Checks (Obj),
3382 Expressions => Index_List);
3384 Set_Etype (Tsk, C_Typ);
3386 if Is_Task_Type (C_Typ) then
3387 Append_To (Stmts, Cleanup_Task (N, Tsk));
3389 elsif Is_Simple_Protected_Type (C_Typ) then
3390 Append_To (Stmts, Cleanup_Protected_Object (N, Tsk));
3392 elsif Is_Record_Type (C_Typ) then
3393 Stmts := Cleanup_Record (N, Tsk, C_Typ);
3395 elsif Is_Array_Type (C_Typ) then
3396 Stmts := Cleanup_Array (N, Tsk, C_Typ);
3397 end if;
3399 return Stmts;
3400 end Free_Component;
3402 ------------------------
3403 -- Free_One_Dimension --
3404 ------------------------
3406 function Free_One_Dimension (Dim : Int) return List_Id is
3407 Index : Entity_Id;
3409 begin
3410 if Dim > Number_Dimensions (Typ) then
3411 return Free_Component;
3413 -- Here we generate the required loop
3415 else
3416 Index := Make_Temporary (Loc, 'J');
3417 Append (New_Occurrence_Of (Index, Loc), Index_List);
3419 return New_List (
3420 Make_Implicit_Loop_Statement (N,
3421 Identifier => Empty,
3422 Iteration_Scheme =>
3423 Make_Iteration_Scheme (Loc,
3424 Loop_Parameter_Specification =>
3425 Make_Loop_Parameter_Specification (Loc,
3426 Defining_Identifier => Index,
3427 Discrete_Subtype_Definition =>
3428 Make_Attribute_Reference (Loc,
3429 Prefix => Duplicate_Subexpr (Obj),
3430 Attribute_Name => Name_Range,
3431 Expressions => New_List (
3432 Make_Integer_Literal (Loc, Dim))))),
3433 Statements => Free_One_Dimension (Dim + 1)));
3434 end if;
3435 end Free_One_Dimension;
3437 -- Start of processing for Cleanup_Array
3439 begin
3440 return Free_One_Dimension (1);
3441 end Cleanup_Array;
3443 --------------------
3444 -- Cleanup_Record --
3445 --------------------
3447 function Cleanup_Record
3448 (N : Node_Id;
3449 Obj : Node_Id;
3450 Typ : Entity_Id) return List_Id
3452 Loc : constant Source_Ptr := Sloc (N);
3453 Tsk : Node_Id;
3454 Comp : Entity_Id;
3455 Stmts : constant List_Id := New_List;
3456 U_Typ : constant Entity_Id := Underlying_Type (Typ);
3458 begin
3459 if Has_Discriminants (U_Typ)
3460 and then Nkind (Parent (U_Typ)) = N_Full_Type_Declaration
3461 and then Nkind (Type_Definition (Parent (U_Typ))) = N_Record_Definition
3462 and then
3463 Present
3464 (Variant_Part (Component_List (Type_Definition (Parent (U_Typ)))))
3465 then
3466 -- For now, do not attempt to free a component that may appear in a
3467 -- variant, and instead issue a warning. Doing this "properly" would
3468 -- require building a case statement and would be quite a mess. Note
3469 -- that the RM only requires that free "work" for the case of a task
3470 -- access value, so already we go way beyond this in that we deal
3471 -- with the array case and non-discriminated record cases.
3473 Error_Msg_N
3474 ("task/protected object in variant record will not be freed??", N);
3475 return New_List (Make_Null_Statement (Loc));
3476 end if;
3478 Comp := First_Component (Typ);
3479 while Present (Comp) loop
3480 if Has_Task (Etype (Comp))
3481 or else Has_Simple_Protected_Object (Etype (Comp))
3482 then
3483 Tsk :=
3484 Make_Selected_Component (Loc,
3485 Prefix => Duplicate_Subexpr_No_Checks (Obj),
3486 Selector_Name => New_Occurrence_Of (Comp, Loc));
3487 Set_Etype (Tsk, Etype (Comp));
3489 if Is_Task_Type (Etype (Comp)) then
3490 Append_To (Stmts, Cleanup_Task (N, Tsk));
3492 elsif Is_Simple_Protected_Type (Etype (Comp)) then
3493 Append_To (Stmts, Cleanup_Protected_Object (N, Tsk));
3495 elsif Is_Record_Type (Etype (Comp)) then
3497 -- Recurse, by generating the prefix of the argument to
3498 -- the eventual cleanup call.
3500 Append_List_To (Stmts, Cleanup_Record (N, Tsk, Etype (Comp)));
3502 elsif Is_Array_Type (Etype (Comp)) then
3503 Append_List_To (Stmts, Cleanup_Array (N, Tsk, Etype (Comp)));
3504 end if;
3505 end if;
3507 Next_Component (Comp);
3508 end loop;
3510 return Stmts;
3511 end Cleanup_Record;
3513 ------------------------------
3514 -- Cleanup_Protected_Object --
3515 ------------------------------
3517 function Cleanup_Protected_Object
3518 (N : Node_Id;
3519 Ref : Node_Id) return Node_Id
3521 Loc : constant Source_Ptr := Sloc (N);
3523 begin
3524 -- For restricted run-time libraries (Ravenscar), tasks are
3525 -- non-terminating, and protected objects can only appear at library
3526 -- level, so we do not want finalization of protected objects.
3528 if Restricted_Profile then
3529 return Empty;
3531 else
3532 return
3533 Make_Procedure_Call_Statement (Loc,
3534 Name =>
3535 New_Occurrence_Of (RTE (RE_Finalize_Protection), Loc),
3536 Parameter_Associations => New_List (Concurrent_Ref (Ref)));
3537 end if;
3538 end Cleanup_Protected_Object;
3540 ------------------
3541 -- Cleanup_Task --
3542 ------------------
3544 function Cleanup_Task
3545 (N : Node_Id;
3546 Ref : Node_Id) return Node_Id
3548 Loc : constant Source_Ptr := Sloc (N);
3550 begin
3551 -- For restricted run-time libraries (Ravenscar), tasks are
3552 -- non-terminating and they can only appear at library level, so we do
3553 -- not want finalization of task objects.
3555 if Restricted_Profile then
3556 return Empty;
3558 else
3559 return
3560 Make_Procedure_Call_Statement (Loc,
3561 Name =>
3562 New_Occurrence_Of (RTE (RE_Free_Task), Loc),
3563 Parameter_Associations => New_List (Concurrent_Ref (Ref)));
3564 end if;
3565 end Cleanup_Task;
3567 ------------------------------
3568 -- Check_Visibly_Controlled --
3569 ------------------------------
3571 procedure Check_Visibly_Controlled
3572 (Prim : Final_Primitives;
3573 Typ : Entity_Id;
3574 E : in out Entity_Id;
3575 Cref : in out Node_Id)
3577 Parent_Type : Entity_Id;
3578 Op : Entity_Id;
3580 begin
3581 if Is_Derived_Type (Typ)
3582 and then Comes_From_Source (E)
3583 and then not Present (Overridden_Operation (E))
3584 then
3585 -- We know that the explicit operation on the type does not override
3586 -- the inherited operation of the parent, and that the derivation
3587 -- is from a private type that is not visibly controlled.
3589 Parent_Type := Etype (Typ);
3590 Op := Find_Prim_Op (Parent_Type, Name_Of (Prim));
3592 if Present (Op) then
3593 E := Op;
3595 -- Wrap the object to be initialized into the proper
3596 -- unchecked conversion, to be compatible with the operation
3597 -- to be called.
3599 if Nkind (Cref) = N_Unchecked_Type_Conversion then
3600 Cref := Unchecked_Convert_To (Parent_Type, Expression (Cref));
3601 else
3602 Cref := Unchecked_Convert_To (Parent_Type, Cref);
3603 end if;
3604 end if;
3605 end if;
3606 end Check_Visibly_Controlled;
3608 -------------------------------
3609 -- CW_Or_Has_Controlled_Part --
3610 -------------------------------
3612 function CW_Or_Has_Controlled_Part (T : Entity_Id) return Boolean is
3613 begin
3614 return Is_Class_Wide_Type (T) or else Needs_Finalization (T);
3615 end CW_Or_Has_Controlled_Part;
3617 ------------------
3618 -- Convert_View --
3619 ------------------
3621 function Convert_View
3622 (Proc : Entity_Id;
3623 Arg : Node_Id;
3624 Ind : Pos := 1) return Node_Id
3626 Fent : Entity_Id := First_Entity (Proc);
3627 Ftyp : Entity_Id;
3628 Atyp : Entity_Id;
3630 begin
3631 for J in 2 .. Ind loop
3632 Next_Entity (Fent);
3633 end loop;
3635 Ftyp := Etype (Fent);
3637 if Nkind_In (Arg, N_Type_Conversion, N_Unchecked_Type_Conversion) then
3638 Atyp := Entity (Subtype_Mark (Arg));
3639 else
3640 Atyp := Etype (Arg);
3641 end if;
3643 if Is_Abstract_Subprogram (Proc) and then Is_Tagged_Type (Ftyp) then
3644 return Unchecked_Convert_To (Class_Wide_Type (Ftyp), Arg);
3646 elsif Ftyp /= Atyp
3647 and then Present (Atyp)
3648 and then (Is_Private_Type (Ftyp) or else Is_Private_Type (Atyp))
3649 and then Base_Type (Underlying_Type (Atyp)) =
3650 Base_Type (Underlying_Type (Ftyp))
3651 then
3652 return Unchecked_Convert_To (Ftyp, Arg);
3654 -- If the argument is already a conversion, as generated by
3655 -- Make_Init_Call, set the target type to the type of the formal
3656 -- directly, to avoid spurious typing problems.
3658 elsif Nkind_In (Arg, N_Unchecked_Type_Conversion, N_Type_Conversion)
3659 and then not Is_Class_Wide_Type (Atyp)
3660 then
3661 Set_Subtype_Mark (Arg, New_Occurrence_Of (Ftyp, Sloc (Arg)));
3662 Set_Etype (Arg, Ftyp);
3663 return Arg;
3665 else
3666 return Arg;
3667 end if;
3668 end Convert_View;
3670 ------------------------
3671 -- Enclosing_Function --
3672 ------------------------
3674 function Enclosing_Function (E : Entity_Id) return Entity_Id is
3675 Func_Id : Entity_Id;
3677 begin
3678 Func_Id := E;
3679 while Present (Func_Id) and then Func_Id /= Standard_Standard loop
3680 if Ekind (Func_Id) = E_Function then
3681 return Func_Id;
3682 end if;
3684 Func_Id := Scope (Func_Id);
3685 end loop;
3687 return Empty;
3688 end Enclosing_Function;
3690 -------------------------------
3691 -- Establish_Transient_Scope --
3692 -------------------------------
3694 -- This procedure is called each time a transient block has to be inserted
3695 -- that is to say for each call to a function with unconstrained or tagged
3696 -- result. It creates a new scope on the stack scope in order to enclose
3697 -- all transient variables generated.
3699 procedure Establish_Transient_Scope (N : Node_Id; Sec_Stack : Boolean) is
3700 Loc : constant Source_Ptr := Sloc (N);
3701 Iter_Loop : Entity_Id;
3702 Wrap_Node : Node_Id;
3704 begin
3705 -- Do not create a transient scope if we are already inside one
3707 for S in reverse Scope_Stack.First .. Scope_Stack.Last loop
3708 if Scope_Stack.Table (S).Is_Transient then
3709 if Sec_Stack then
3710 Set_Uses_Sec_Stack (Scope_Stack.Table (S).Entity);
3711 end if;
3713 return;
3715 -- If we encounter Standard there are no enclosing transient scopes
3717 elsif Scope_Stack.Table (S).Entity = Standard_Standard then
3718 exit;
3719 end if;
3720 end loop;
3722 Wrap_Node := Find_Node_To_Be_Wrapped (N);
3724 -- The context does not contain a node that requires a transient scope,
3725 -- nothing to do.
3727 if No (Wrap_Node) then
3728 null;
3730 -- If the node to wrap is an iteration_scheme, the expression is one of
3731 -- the bounds, and the expansion will make an explicit declaration for
3732 -- it (see Analyze_Iteration_Scheme, sem_ch5.adb), so do not apply any
3733 -- transformations here. Same for an Ada 2012 iterator specification,
3734 -- where a block is created for the expression that build the container.
3736 elsif Nkind_In (Wrap_Node, N_Iteration_Scheme,
3737 N_Iterator_Specification)
3738 then
3739 null;
3741 -- In formal verification mode, if the node to wrap is a pragma check,
3742 -- this node and enclosed expression are not expanded, so do not apply
3743 -- any transformations here.
3745 elsif GNATprove_Mode
3746 and then Nkind (Wrap_Node) = N_Pragma
3747 and then Get_Pragma_Id (Wrap_Node) = Pragma_Check
3748 then
3749 null;
3751 -- Create a block entity to act as a transient scope. Note that when the
3752 -- node to be wrapped is an expression or a statement, a real physical
3753 -- block is constructed (see routines Wrap_Transient_Expression and
3754 -- Wrap_Transient_Statement) and inserted into the tree.
3756 else
3757 Push_Scope (New_Internal_Entity (E_Block, Current_Scope, Loc, 'B'));
3758 Set_Scope_Is_Transient;
3760 -- The transient scope must also take care of the secondary stack
3761 -- management.
3763 if Sec_Stack then
3764 Set_Uses_Sec_Stack (Current_Scope);
3765 Check_Restriction (No_Secondary_Stack, N);
3767 -- The expansion of iterator loops generates references to objects
3768 -- in order to extract elements from a container:
3770 -- Ref : Reference_Type_Ptr := Reference (Container, Cursor);
3771 -- Obj : <object type> renames Ref.all.Element.all;
3773 -- These references are controlled and returned on the secondary
3774 -- stack. A new reference is created at each iteration of the loop
3775 -- and as a result it must be finalized and the space occupied by
3776 -- it on the secondary stack reclaimed at the end of the current
3777 -- iteration.
3779 -- When the context that requires a transient scope is a call to
3780 -- routine Reference, the node to be wrapped is the source object:
3782 -- for Obj of Container loop
3784 -- Routine Wrap_Transient_Declaration however does not generate a
3785 -- physical block as wrapping a declaration will kill it too ealy.
3786 -- To handle this peculiar case, mark the related iterator loop as
3787 -- requiring the secondary stack. This signals the finalization
3788 -- machinery to manage the secondary stack (see routine
3789 -- Process_Statements_For_Controlled_Objects).
3791 Iter_Loop := Find_Enclosing_Iterator_Loop (Current_Scope);
3793 if Present (Iter_Loop) then
3794 Set_Uses_Sec_Stack (Iter_Loop);
3795 end if;
3796 end if;
3798 Set_Etype (Current_Scope, Standard_Void_Type);
3799 Set_Node_To_Be_Wrapped (Wrap_Node);
3801 if Debug_Flag_W then
3802 Write_Str (" <Transient>");
3803 Write_Eol;
3804 end if;
3805 end if;
3806 end Establish_Transient_Scope;
3808 ----------------------------
3809 -- Expand_Cleanup_Actions --
3810 ----------------------------
3812 procedure Expand_Cleanup_Actions (N : Node_Id) is
3813 Scop : constant Entity_Id := Current_Scope;
3815 Is_Asynchronous_Call : constant Boolean :=
3816 Nkind (N) = N_Block_Statement
3817 and then Is_Asynchronous_Call_Block (N);
3818 Is_Master : constant Boolean :=
3819 Nkind (N) /= N_Entry_Body
3820 and then Is_Task_Master (N);
3821 Is_Protected_Body : constant Boolean :=
3822 Nkind (N) = N_Subprogram_Body
3823 and then Is_Protected_Subprogram_Body (N);
3824 Is_Task_Allocation : constant Boolean :=
3825 Nkind (N) = N_Block_Statement
3826 and then Is_Task_Allocation_Block (N);
3827 Is_Task_Body : constant Boolean :=
3828 Nkind (Original_Node (N)) = N_Task_Body;
3829 Needs_Sec_Stack_Mark : constant Boolean :=
3830 Uses_Sec_Stack (Scop)
3831 and then
3832 not Sec_Stack_Needed_For_Return (Scop)
3833 and then VM_Target = No_VM;
3834 Needs_Custom_Cleanup : constant Boolean :=
3835 Nkind (N) = N_Block_Statement
3836 and then Present (Cleanup_Actions (N));
3838 Actions_Required : constant Boolean :=
3839 Requires_Cleanup_Actions (N, True)
3840 or else Is_Asynchronous_Call
3841 or else Is_Master
3842 or else Is_Protected_Body
3843 or else Is_Task_Allocation
3844 or else Is_Task_Body
3845 or else Needs_Sec_Stack_Mark
3846 or else Needs_Custom_Cleanup;
3848 HSS : Node_Id := Handled_Statement_Sequence (N);
3849 Loc : Source_Ptr;
3850 Cln : List_Id;
3852 procedure Wrap_HSS_In_Block;
3853 -- Move HSS inside a new block along with the original exception
3854 -- handlers. Make the newly generated block the sole statement of HSS.
3856 -----------------------
3857 -- Wrap_HSS_In_Block --
3858 -----------------------
3860 procedure Wrap_HSS_In_Block is
3861 Block : Node_Id;
3862 End_Lab : Node_Id;
3864 begin
3865 -- Preserve end label to provide proper cross-reference information
3867 End_Lab := End_Label (HSS);
3868 Block :=
3869 Make_Block_Statement (Loc, Handled_Statement_Sequence => HSS);
3871 -- Signal the finalization machinery that this particular block
3872 -- contains the original context.
3874 Set_Is_Finalization_Wrapper (Block);
3876 Set_Handled_Statement_Sequence (N,
3877 Make_Handled_Sequence_Of_Statements (Loc, New_List (Block)));
3878 HSS := Handled_Statement_Sequence (N);
3880 Set_First_Real_Statement (HSS, Block);
3881 Set_End_Label (HSS, End_Lab);
3883 -- Comment needed here, see RH for 1.306 ???
3885 if Nkind (N) = N_Subprogram_Body then
3886 Set_Has_Nested_Block_With_Handler (Scop);
3887 end if;
3888 end Wrap_HSS_In_Block;
3890 -- Start of processing for Expand_Cleanup_Actions
3892 begin
3893 -- The current construct does not need any form of servicing
3895 if not Actions_Required then
3896 return;
3898 -- If the current node is a rewritten task body and the descriptors have
3899 -- not been delayed (due to some nested instantiations), do not generate
3900 -- redundant cleanup actions.
3902 elsif Is_Task_Body
3903 and then Nkind (N) = N_Subprogram_Body
3904 and then not Delay_Subprogram_Descriptors (Corresponding_Spec (N))
3905 then
3906 return;
3907 end if;
3909 if Needs_Custom_Cleanup then
3910 Cln := Cleanup_Actions (N);
3911 else
3912 Cln := No_List;
3913 end if;
3915 declare
3916 Decls : List_Id := Declarations (N);
3917 Fin_Id : Entity_Id;
3918 Mark : Entity_Id := Empty;
3919 New_Decls : List_Id;
3920 Old_Poll : Boolean;
3922 begin
3923 -- If we are generating expanded code for debugging purposes, use the
3924 -- Sloc of the point of insertion for the cleanup code. The Sloc will
3925 -- be updated subsequently to reference the proper line in .dg files.
3926 -- If we are not debugging generated code, use No_Location instead,
3927 -- so that no debug information is generated for the cleanup code.
3928 -- This makes the behavior of the NEXT command in GDB monotonic, and
3929 -- makes the placement of breakpoints more accurate.
3931 if Debug_Generated_Code then
3932 Loc := Sloc (Scop);
3933 else
3934 Loc := No_Location;
3935 end if;
3937 -- Set polling off. The finalization and cleanup code is executed
3938 -- with aborts deferred.
3940 Old_Poll := Polling_Required;
3941 Polling_Required := False;
3943 -- A task activation call has already been built for a task
3944 -- allocation block.
3946 if not Is_Task_Allocation then
3947 Build_Task_Activation_Call (N);
3948 end if;
3950 if Is_Master then
3951 Establish_Task_Master (N);
3952 end if;
3954 New_Decls := New_List;
3956 -- If secondary stack is in use, generate:
3958 -- Mnn : constant Mark_Id := SS_Mark;
3960 -- Suppress calls to SS_Mark and SS_Release if VM_Target, since the
3961 -- secondary stack is never used on a VM.
3963 if Needs_Sec_Stack_Mark then
3964 Mark := Make_Temporary (Loc, 'M');
3966 Append_To (New_Decls, Build_SS_Mark_Call (Loc, Mark));
3967 Set_Uses_Sec_Stack (Scop, False);
3968 end if;
3970 -- If exception handlers are present, wrap the sequence of statements
3971 -- in a block since it is not possible to have exception handlers and
3972 -- an At_End handler in the same construct.
3974 if Present (Exception_Handlers (HSS)) then
3975 Wrap_HSS_In_Block;
3977 -- Ensure that the First_Real_Statement field is set
3979 elsif No (First_Real_Statement (HSS)) then
3980 Set_First_Real_Statement (HSS, First (Statements (HSS)));
3981 end if;
3983 -- Do not move the Activation_Chain declaration in the context of
3984 -- task allocation blocks. Task allocation blocks use _chain in their
3985 -- cleanup handlers and gigi complains if it is declared in the
3986 -- sequence of statements of the scope that declares the handler.
3988 if Is_Task_Allocation then
3989 declare
3990 Chain : constant Entity_Id := Activation_Chain_Entity (N);
3991 Decl : Node_Id;
3993 begin
3994 Decl := First (Decls);
3995 while Nkind (Decl) /= N_Object_Declaration
3996 or else Defining_Identifier (Decl) /= Chain
3997 loop
3998 Next (Decl);
4000 -- A task allocation block should always include a _chain
4001 -- declaration.
4003 pragma Assert (Present (Decl));
4004 end loop;
4006 Remove (Decl);
4007 Prepend_To (New_Decls, Decl);
4008 end;
4009 end if;
4011 -- Ensure the presence of a declaration list in order to successfully
4012 -- append all original statements to it.
4014 if No (Decls) then
4015 Set_Declarations (N, New_List);
4016 Decls := Declarations (N);
4017 end if;
4019 -- Move the declarations into the sequence of statements in order to
4020 -- have them protected by the At_End handler. It may seem weird to
4021 -- put declarations in the sequence of statement but in fact nothing
4022 -- forbids that at the tree level.
4024 Append_List_To (Decls, Statements (HSS));
4025 Set_Statements (HSS, Decls);
4027 -- Reset the Sloc of the handled statement sequence to properly
4028 -- reflect the new initial "statement" in the sequence.
4030 Set_Sloc (HSS, Sloc (First (Decls)));
4032 -- The declarations of finalizer spec and auxiliary variables replace
4033 -- the old declarations that have been moved inward.
4035 Set_Declarations (N, New_Decls);
4036 Analyze_Declarations (New_Decls);
4038 -- Generate finalization calls for all controlled objects appearing
4039 -- in the statements of N. Add context specific cleanup for various
4040 -- constructs.
4042 Build_Finalizer
4043 (N => N,
4044 Clean_Stmts => Build_Cleanup_Statements (N, Cln),
4045 Mark_Id => Mark,
4046 Top_Decls => New_Decls,
4047 Defer_Abort => Nkind (Original_Node (N)) = N_Task_Body
4048 or else Is_Master,
4049 Fin_Id => Fin_Id);
4051 if Present (Fin_Id) then
4052 Build_Finalizer_Call (N, Fin_Id);
4053 end if;
4055 -- Restore saved polling mode
4057 Polling_Required := Old_Poll;
4058 end;
4059 end Expand_Cleanup_Actions;
4061 ---------------------------
4062 -- Expand_N_Package_Body --
4063 ---------------------------
4065 -- Add call to Activate_Tasks if body is an activator (actual processing
4066 -- is in chapter 9).
4068 -- Generate subprogram descriptor for elaboration routine
4070 -- Encode entity names in package body
4072 procedure Expand_N_Package_Body (N : Node_Id) is
4073 Spec_Ent : constant Entity_Id := Corresponding_Spec (N);
4074 Fin_Id : Entity_Id;
4076 begin
4077 -- This is done only for non-generic packages
4079 if Ekind (Spec_Ent) = E_Package then
4080 Push_Scope (Corresponding_Spec (N));
4082 -- Build dispatch tables of library level tagged types
4084 if Tagged_Type_Expansion
4085 and then Is_Library_Level_Entity (Spec_Ent)
4086 then
4087 Build_Static_Dispatch_Tables (N);
4088 end if;
4090 Build_Task_Activation_Call (N);
4092 -- When the package is subject to pragma Initial_Condition, the
4093 -- assertion expression must be verified at the end of the body
4094 -- statements.
4096 if Present (Get_Pragma (Spec_Ent, Pragma_Initial_Condition)) then
4097 Expand_Pragma_Initial_Condition (N);
4098 end if;
4100 Pop_Scope;
4101 end if;
4103 Set_Elaboration_Flag (N, Corresponding_Spec (N));
4104 Set_In_Package_Body (Spec_Ent, False);
4106 -- Set to encode entity names in package body before gigi is called
4108 Qualify_Entity_Names (N);
4110 if Ekind (Spec_Ent) /= E_Generic_Package then
4111 Build_Finalizer
4112 (N => N,
4113 Clean_Stmts => No_List,
4114 Mark_Id => Empty,
4115 Top_Decls => No_List,
4116 Defer_Abort => False,
4117 Fin_Id => Fin_Id);
4119 if Present (Fin_Id) then
4120 declare
4121 Body_Ent : Node_Id := Defining_Unit_Name (N);
4123 begin
4124 if Nkind (Body_Ent) = N_Defining_Program_Unit_Name then
4125 Body_Ent := Defining_Identifier (Body_Ent);
4126 end if;
4128 Set_Finalizer (Body_Ent, Fin_Id);
4129 end;
4130 end if;
4131 end if;
4132 end Expand_N_Package_Body;
4134 ----------------------------------
4135 -- Expand_N_Package_Declaration --
4136 ----------------------------------
4138 -- Add call to Activate_Tasks if there are tasks declared and the package
4139 -- has no body. Note that in Ada 83 this may result in premature activation
4140 -- of some tasks, given that we cannot tell whether a body will eventually
4141 -- appear.
4143 procedure Expand_N_Package_Declaration (N : Node_Id) is
4144 Id : constant Entity_Id := Defining_Entity (N);
4145 Spec : constant Node_Id := Specification (N);
4146 Decls : List_Id;
4147 Fin_Id : Entity_Id;
4149 No_Body : Boolean := False;
4150 -- True in the case of a package declaration that is a compilation
4151 -- unit and for which no associated body will be compiled in this
4152 -- compilation.
4154 begin
4155 -- Case of a package declaration other than a compilation unit
4157 if Nkind (Parent (N)) /= N_Compilation_Unit then
4158 null;
4160 -- Case of a compilation unit that does not require a body
4162 elsif not Body_Required (Parent (N))
4163 and then not Unit_Requires_Body (Id)
4164 then
4165 No_Body := True;
4167 -- Special case of generating calling stubs for a remote call interface
4168 -- package: even though the package declaration requires one, the body
4169 -- won't be processed in this compilation (so any stubs for RACWs
4170 -- declared in the package must be generated here, along with the spec).
4172 elsif Parent (N) = Cunit (Main_Unit)
4173 and then Is_Remote_Call_Interface (Id)
4174 and then Distribution_Stub_Mode = Generate_Caller_Stub_Body
4175 then
4176 No_Body := True;
4177 end if;
4179 -- For a nested instance, delay processing until freeze point
4181 if Has_Delayed_Freeze (Id)
4182 and then Nkind (Parent (N)) /= N_Compilation_Unit
4183 then
4184 return;
4185 end if;
4187 -- For a package declaration that implies no associated body, generate
4188 -- task activation call and RACW supporting bodies now (since we won't
4189 -- have a specific separate compilation unit for that).
4191 if No_Body then
4192 Push_Scope (Id);
4194 -- Generate RACW subprogram bodies
4196 if Has_RACW (Id) then
4197 Decls := Private_Declarations (Spec);
4199 if No (Decls) then
4200 Decls := Visible_Declarations (Spec);
4201 end if;
4203 if No (Decls) then
4204 Decls := New_List;
4205 Set_Visible_Declarations (Spec, Decls);
4206 end if;
4208 Append_RACW_Bodies (Decls, Id);
4209 Analyze_List (Decls);
4210 end if;
4212 -- Generate task activation call as last step of elaboration
4214 if Present (Activation_Chain_Entity (N)) then
4215 Build_Task_Activation_Call (N);
4216 end if;
4218 -- When the package is subject to pragma Initial_Condition and lacks
4219 -- a body, the assertion expression must be verified at the end of
4220 -- the visible declarations. Otherwise the check is performed at the
4221 -- end of the body statements (see Expand_N_Package_Body).
4223 if Present (Get_Pragma (Id, Pragma_Initial_Condition)) then
4224 Expand_Pragma_Initial_Condition (N);
4225 end if;
4227 Pop_Scope;
4228 end if;
4230 -- Build dispatch tables of library level tagged types
4232 if Tagged_Type_Expansion
4233 and then (Is_Compilation_Unit (Id)
4234 or else (Is_Generic_Instance (Id)
4235 and then Is_Library_Level_Entity (Id)))
4236 then
4237 Build_Static_Dispatch_Tables (N);
4238 end if;
4240 -- Note: it is not necessary to worry about generating a subprogram
4241 -- descriptor, since the only way to get exception handlers into a
4242 -- package spec is to include instantiations, and that would cause
4243 -- generation of subprogram descriptors to be delayed in any case.
4245 -- Set to encode entity names in package spec before gigi is called
4247 Qualify_Entity_Names (N);
4249 if Ekind (Id) /= E_Generic_Package then
4250 Build_Finalizer
4251 (N => N,
4252 Clean_Stmts => No_List,
4253 Mark_Id => Empty,
4254 Top_Decls => No_List,
4255 Defer_Abort => False,
4256 Fin_Id => Fin_Id);
4258 Set_Finalizer (Id, Fin_Id);
4259 end if;
4260 end Expand_N_Package_Declaration;
4262 -----------------------------
4263 -- Find_Node_To_Be_Wrapped --
4264 -----------------------------
4266 function Find_Node_To_Be_Wrapped (N : Node_Id) return Node_Id is
4267 P : Node_Id;
4268 The_Parent : Node_Id;
4270 begin
4271 The_Parent := N;
4272 P := Empty;
4273 loop
4274 case Nkind (The_Parent) is
4276 -- Simple statement can be wrapped
4278 when N_Pragma =>
4279 return The_Parent;
4281 -- Usually assignments are good candidate for wrapping except
4282 -- when they have been generated as part of a controlled aggregate
4283 -- where the wrapping should take place more globally. Note that
4284 -- No_Ctrl_Actions may be set also for non-controlled assignements
4285 -- in order to disable the use of dispatching _assign, so we need
4286 -- to test explicitly for a controlled type here.
4288 when N_Assignment_Statement =>
4289 if No_Ctrl_Actions (The_Parent)
4290 and then Needs_Finalization (Etype (Name (The_Parent)))
4291 then
4292 null;
4293 else
4294 return The_Parent;
4295 end if;
4297 -- An entry call statement is a special case if it occurs in the
4298 -- context of a Timed_Entry_Call. In this case we wrap the entire
4299 -- timed entry call.
4301 when N_Entry_Call_Statement |
4302 N_Procedure_Call_Statement =>
4303 if Nkind (Parent (The_Parent)) = N_Entry_Call_Alternative
4304 and then Nkind_In (Parent (Parent (The_Parent)),
4305 N_Timed_Entry_Call,
4306 N_Conditional_Entry_Call)
4307 then
4308 return Parent (Parent (The_Parent));
4309 else
4310 return The_Parent;
4311 end if;
4313 -- Object declarations are also a boundary for the transient scope
4314 -- even if they are not really wrapped. For further details, see
4315 -- Wrap_Transient_Declaration.
4317 when N_Object_Declaration |
4318 N_Object_Renaming_Declaration |
4319 N_Subtype_Declaration =>
4320 return The_Parent;
4322 -- The expression itself is to be wrapped if its parent is a
4323 -- compound statement or any other statement where the expression
4324 -- is known to be scalar.
4326 when N_Accept_Alternative |
4327 N_Attribute_Definition_Clause |
4328 N_Case_Statement |
4329 N_Code_Statement |
4330 N_Delay_Alternative |
4331 N_Delay_Until_Statement |
4332 N_Delay_Relative_Statement |
4333 N_Discriminant_Association |
4334 N_Elsif_Part |
4335 N_Entry_Body_Formal_Part |
4336 N_Exit_Statement |
4337 N_If_Statement |
4338 N_Iteration_Scheme |
4339 N_Terminate_Alternative =>
4340 pragma Assert (Present (P));
4341 return P;
4343 when N_Attribute_Reference =>
4345 if Is_Procedure_Attribute_Name
4346 (Attribute_Name (The_Parent))
4347 then
4348 return The_Parent;
4349 end if;
4351 -- A raise statement can be wrapped. This will arise when the
4352 -- expression in a raise_with_expression uses the secondary
4353 -- stack, for example.
4355 when N_Raise_Statement =>
4356 return The_Parent;
4358 -- If the expression is within the iteration scheme of a loop,
4359 -- we must create a declaration for it, followed by an assignment
4360 -- in order to have a usable statement to wrap.
4362 when N_Loop_Parameter_Specification =>
4363 return Parent (The_Parent);
4365 -- The following nodes contains "dummy calls" which don't need to
4366 -- be wrapped.
4368 when N_Parameter_Specification |
4369 N_Discriminant_Specification |
4370 N_Component_Declaration =>
4371 return Empty;
4373 -- The return statement is not to be wrapped when the function
4374 -- itself needs wrapping at the outer-level
4376 when N_Simple_Return_Statement =>
4377 declare
4378 Applies_To : constant Entity_Id :=
4379 Return_Applies_To
4380 (Return_Statement_Entity (The_Parent));
4381 Return_Type : constant Entity_Id := Etype (Applies_To);
4382 begin
4383 if Requires_Transient_Scope (Return_Type) then
4384 return Empty;
4385 else
4386 return The_Parent;
4387 end if;
4388 end;
4390 -- If we leave a scope without having been able to find a node to
4391 -- wrap, something is going wrong but this can happen in error
4392 -- situation that are not detected yet (such as a dynamic string
4393 -- in a pragma export)
4395 when N_Subprogram_Body |
4396 N_Package_Declaration |
4397 N_Package_Body |
4398 N_Block_Statement =>
4399 return Empty;
4401 -- Otherwise continue the search
4403 when others =>
4404 null;
4405 end case;
4407 P := The_Parent;
4408 The_Parent := Parent (P);
4409 end loop;
4410 end Find_Node_To_Be_Wrapped;
4412 ----------------------------------
4413 -- Has_New_Controlled_Component --
4414 ----------------------------------
4416 function Has_New_Controlled_Component (E : Entity_Id) return Boolean is
4417 Comp : Entity_Id;
4419 begin
4420 if not Is_Tagged_Type (E) then
4421 return Has_Controlled_Component (E);
4422 elsif not Is_Derived_Type (E) then
4423 return Has_Controlled_Component (E);
4424 end if;
4426 Comp := First_Component (E);
4427 while Present (Comp) loop
4428 if Chars (Comp) = Name_uParent then
4429 null;
4431 elsif Scope (Original_Record_Component (Comp)) = E
4432 and then Needs_Finalization (Etype (Comp))
4433 then
4434 return True;
4435 end if;
4437 Next_Component (Comp);
4438 end loop;
4440 return False;
4441 end Has_New_Controlled_Component;
4443 ---------------------------------
4444 -- Has_Simple_Protected_Object --
4445 ---------------------------------
4447 function Has_Simple_Protected_Object (T : Entity_Id) return Boolean is
4448 begin
4449 if Has_Task (T) then
4450 return False;
4452 elsif Is_Simple_Protected_Type (T) then
4453 return True;
4455 elsif Is_Array_Type (T) then
4456 return Has_Simple_Protected_Object (Component_Type (T));
4458 elsif Is_Record_Type (T) then
4459 declare
4460 Comp : Entity_Id;
4462 begin
4463 Comp := First_Component (T);
4464 while Present (Comp) loop
4465 if Has_Simple_Protected_Object (Etype (Comp)) then
4466 return True;
4467 end if;
4469 Next_Component (Comp);
4470 end loop;
4472 return False;
4473 end;
4475 else
4476 return False;
4477 end if;
4478 end Has_Simple_Protected_Object;
4480 ------------------------------------
4481 -- Insert_Actions_In_Scope_Around --
4482 ------------------------------------
4484 procedure Insert_Actions_In_Scope_Around
4485 (N : Node_Id;
4486 Clean : Boolean;
4487 Manage_SS : Boolean)
4489 Act_Before : constant List_Id :=
4490 Scope_Stack.Table (Scope_Stack.Last).Actions_To_Be_Wrapped (Before);
4491 Act_After : constant List_Id :=
4492 Scope_Stack.Table (Scope_Stack.Last).Actions_To_Be_Wrapped (After);
4493 Act_Cleanup : constant List_Id :=
4494 Scope_Stack.Table (Scope_Stack.Last).Actions_To_Be_Wrapped (Cleanup);
4495 -- Note: We used to use renamings of Scope_Stack.Table (Scope_Stack.
4496 -- Last), but this was incorrect as Process_Transient_Object may
4497 -- introduce new scopes and cause a reallocation of Scope_Stack.Table.
4499 procedure Process_Transient_Objects
4500 (First_Object : Node_Id;
4501 Last_Object : Node_Id;
4502 Related_Node : Node_Id);
4503 -- First_Object and Last_Object define a list which contains potential
4504 -- controlled transient objects. Finalization flags are inserted before
4505 -- First_Object and finalization calls are inserted after Last_Object.
4506 -- Related_Node is the node for which transient objects have been
4507 -- created.
4509 -------------------------------
4510 -- Process_Transient_Objects --
4511 -------------------------------
4513 procedure Process_Transient_Objects
4514 (First_Object : Node_Id;
4515 Last_Object : Node_Id;
4516 Related_Node : Node_Id)
4518 Must_Hook : Boolean := False;
4519 -- Flag denoting whether the context requires transient variable
4520 -- export to the outer finalizer.
4522 function Is_Subprogram_Call (N : Node_Id) return Traverse_Result;
4523 -- Determine whether an arbitrary node denotes a subprogram call
4525 procedure Detect_Subprogram_Call is
4526 new Traverse_Proc (Is_Subprogram_Call);
4528 ------------------------
4529 -- Is_Subprogram_Call --
4530 ------------------------
4532 function Is_Subprogram_Call (N : Node_Id) return Traverse_Result is
4533 begin
4534 -- Complex constructs are factored out by the expander and their
4535 -- occurrences are replaced with references to temporaries or
4536 -- object renamings. Due to this expansion activity, inspect the
4537 -- original tree to detect subprogram calls.
4539 if Nkind_In (N, N_Identifier,
4540 N_Object_Renaming_Declaration)
4541 and then Original_Node (N) /= N
4542 then
4543 Detect_Subprogram_Call (Original_Node (N));
4545 -- The original construct contains a subprogram call, there is
4546 -- no point in continuing the tree traversal.
4548 if Must_Hook then
4549 return Abandon;
4550 else
4551 return OK;
4552 end if;
4554 -- The original construct contains a subprogram call, there is no
4555 -- point in continuing the tree traversal.
4557 elsif Nkind (N) = N_Object_Declaration
4558 and then Present (Expression (N))
4559 and then Nkind (Original_Node (Expression (N))) = N_Function_Call
4560 then
4561 Must_Hook := True;
4562 return Abandon;
4564 -- A regular procedure or function call
4566 elsif Nkind (N) in N_Subprogram_Call then
4567 Must_Hook := True;
4568 return Abandon;
4570 -- Keep searching
4572 else
4573 return OK;
4574 end if;
4575 end Is_Subprogram_Call;
4577 -- Local variables
4579 Built : Boolean := False;
4580 Desig_Typ : Entity_Id;
4581 Expr : Node_Id;
4582 Fin_Block : Node_Id;
4583 Fin_Data : Finalization_Exception_Data;
4584 Fin_Decls : List_Id;
4585 Fin_Insrt : Node_Id;
4586 Last_Fin : Node_Id := Empty;
4587 Loc : Source_Ptr;
4588 Obj_Id : Entity_Id;
4589 Obj_Ref : Node_Id;
4590 Obj_Typ : Entity_Id;
4591 Prev_Fin : Node_Id := Empty;
4592 Ptr_Id : Entity_Id;
4593 Stmt : Node_Id;
4594 Stmts : List_Id;
4595 Temp_Id : Entity_Id;
4596 Temp_Ins : Node_Id;
4598 -- Start of processing for Process_Transient_Objects
4600 begin
4601 -- Recognize a scenario where the transient context is an object
4602 -- declaration initialized by a build-in-place function call:
4604 -- Obj : ... := BIP_Function_Call (Ctrl_Func_Call);
4606 -- The rough expansion of the above is:
4608 -- Temp : ... := Ctrl_Func_Call;
4609 -- Obj : ...;
4610 -- Res : ... := BIP_Func_Call (..., Obj, ...);
4612 -- The finalization of any controlled transient must happen after
4613 -- the build-in-place function call is executed.
4615 if Nkind (N) = N_Object_Declaration
4616 and then Present (BIP_Initialization_Call (Defining_Identifier (N)))
4617 then
4618 Must_Hook := True;
4619 Fin_Insrt := BIP_Initialization_Call (Defining_Identifier (N));
4621 -- Search the context for at least one subprogram call. If found, the
4622 -- machinery exports all transient objects to the enclosing finalizer
4623 -- due to the possibility of abnormal call termination.
4625 else
4626 Detect_Subprogram_Call (N);
4627 Fin_Insrt := Last_Object;
4628 end if;
4630 -- Examine all objects in the list First_Object .. Last_Object
4632 Stmt := First_Object;
4633 while Present (Stmt) loop
4634 if Nkind (Stmt) = N_Object_Declaration
4635 and then Analyzed (Stmt)
4636 and then Is_Finalizable_Transient (Stmt, N)
4638 -- Do not process the node to be wrapped since it will be
4639 -- handled by the enclosing finalizer.
4641 and then Stmt /= Related_Node
4642 then
4643 Loc := Sloc (Stmt);
4644 Obj_Id := Defining_Identifier (Stmt);
4645 Obj_Typ := Base_Type (Etype (Obj_Id));
4646 Desig_Typ := Obj_Typ;
4648 Set_Is_Processed_Transient (Obj_Id);
4650 -- Handle access types
4652 if Is_Access_Type (Desig_Typ) then
4653 Desig_Typ := Available_View (Designated_Type (Desig_Typ));
4654 end if;
4656 -- Create the necessary entities and declarations the first
4657 -- time around.
4659 if not Built then
4660 Built := True;
4661 Fin_Decls := New_List;
4663 Build_Object_Declarations (Fin_Data, Fin_Decls, Loc);
4664 end if;
4666 -- Transient variables associated with subprogram calls need
4667 -- extra processing. These variables are usually created right
4668 -- before the call and finalized immediately after the call.
4669 -- If an exception occurs during the call, the clean up code
4670 -- is skipped due to the sudden change in control and the
4671 -- transient is never finalized.
4673 -- To handle this case, such variables are "exported" to the
4674 -- enclosing sequence of statements where their corresponding
4675 -- "hooks" are picked up by the finalization machinery.
4677 if Must_Hook then
4679 -- Step 1: Create an access type which provides a reference
4680 -- to the transient object. Generate:
4682 -- Ann : access [all] <Desig_Typ>;
4684 Ptr_Id := Make_Temporary (Loc, 'A');
4686 Insert_Action (Stmt,
4687 Make_Full_Type_Declaration (Loc,
4688 Defining_Identifier => Ptr_Id,
4689 Type_Definition =>
4690 Make_Access_To_Object_Definition (Loc,
4691 All_Present =>
4692 Ekind (Obj_Typ) = E_General_Access_Type,
4693 Subtype_Indication =>
4694 New_Occurrence_Of (Desig_Typ, Loc))));
4696 -- Step 2: Create a temporary which acts as a hook to the
4697 -- transient object. Generate:
4699 -- Temp : Ptr_Id := null;
4701 Temp_Id := Make_Temporary (Loc, 'T');
4703 Insert_Action (Stmt,
4704 Make_Object_Declaration (Loc,
4705 Defining_Identifier => Temp_Id,
4706 Object_Definition =>
4707 New_Occurrence_Of (Ptr_Id, Loc)));
4709 -- Mark the temporary as a transient hook. This signals the
4710 -- machinery in Build_Finalizer to recognize this special
4711 -- case.
4713 Set_Status_Flag_Or_Transient_Decl (Temp_Id, Stmt);
4715 -- Step 3: Hook the transient object to the temporary
4717 if Is_Access_Type (Obj_Typ) then
4718 Expr :=
4719 Convert_To (Ptr_Id, New_Occurrence_Of (Obj_Id, Loc));
4720 else
4721 Expr :=
4722 Make_Attribute_Reference (Loc,
4723 Prefix => New_Occurrence_Of (Obj_Id, Loc),
4724 Attribute_Name => Name_Unrestricted_Access);
4725 end if;
4727 -- Generate:
4728 -- Temp := Ptr_Id (Obj_Id);
4729 -- <or>
4730 -- Temp := Obj_Id'Unrestricted_Access;
4732 -- When the transient object is initialized by an aggregate,
4733 -- the hook must capture the object after the last component
4734 -- assignment takes place. Only then is the object fully
4735 -- initialized.
4737 if Ekind (Obj_Id) = E_Variable
4738 and then Present (Last_Aggregate_Assignment (Obj_Id))
4739 then
4740 Temp_Ins := Last_Aggregate_Assignment (Obj_Id);
4742 -- Otherwise the hook seizes the related object immediately
4744 else
4745 Temp_Ins := Stmt;
4746 end if;
4748 Insert_After_And_Analyze (Temp_Ins,
4749 Make_Assignment_Statement (Loc,
4750 Name => New_Occurrence_Of (Temp_Id, Loc),
4751 Expression => Expr));
4752 end if;
4754 Stmts := New_List;
4756 -- The transient object is about to be finalized by the clean
4757 -- up code following the subprogram call. In order to avoid
4758 -- double finalization, clear the hook.
4760 -- Generate:
4761 -- Temp := null;
4763 if Must_Hook then
4764 Append_To (Stmts,
4765 Make_Assignment_Statement (Loc,
4766 Name => New_Occurrence_Of (Temp_Id, Loc),
4767 Expression => Make_Null (Loc)));
4768 end if;
4770 -- Generate:
4771 -- [Deep_]Finalize (Obj_Ref);
4773 Obj_Ref := New_Occurrence_Of (Obj_Id, Loc);
4775 if Is_Access_Type (Obj_Typ) then
4776 Obj_Ref := Make_Explicit_Dereference (Loc, Obj_Ref);
4777 end if;
4779 Append_To (Stmts,
4780 Make_Final_Call (Obj_Ref => Obj_Ref, Typ => Desig_Typ));
4782 -- Generate:
4783 -- [Temp := null;]
4784 -- begin
4785 -- [Deep_]Finalize (Obj_Ref);
4787 -- exception
4788 -- when others =>
4789 -- if not Raised then
4790 -- Raised := True;
4791 -- Save_Occurrence
4792 -- (Enn, Get_Current_Excep.all.all);
4793 -- end if;
4794 -- end;
4796 Fin_Block :=
4797 Make_Block_Statement (Loc,
4798 Handled_Statement_Sequence =>
4799 Make_Handled_Sequence_Of_Statements (Loc,
4800 Statements => Stmts,
4801 Exception_Handlers => New_List (
4802 Build_Exception_Handler (Fin_Data))));
4804 -- The single raise statement must be inserted after all the
4805 -- finalization blocks, and we put everything into a wrapper
4806 -- block to clearly expose the construct to the back-end.
4808 if Present (Prev_Fin) then
4809 Insert_Before_And_Analyze (Prev_Fin, Fin_Block);
4810 else
4811 Insert_After_And_Analyze (Fin_Insrt,
4812 Make_Block_Statement (Loc,
4813 Declarations => Fin_Decls,
4814 Handled_Statement_Sequence =>
4815 Make_Handled_Sequence_Of_Statements (Loc,
4816 Statements => New_List (Fin_Block))));
4818 Last_Fin := Fin_Block;
4819 end if;
4821 Prev_Fin := Fin_Block;
4822 end if;
4824 -- Terminate the scan after the last object has been processed to
4825 -- avoid touching unrelated code.
4827 if Stmt = Last_Object then
4828 exit;
4829 end if;
4831 Next (Stmt);
4832 end loop;
4834 if Clean then
4835 if Present (Prev_Fin) then
4836 Insert_List_Before_And_Analyze (Prev_Fin, Act_Cleanup);
4837 else
4838 Insert_List_After_And_Analyze (Fin_Insrt, Act_Cleanup);
4839 end if;
4840 end if;
4842 -- Generate:
4843 -- if Raised and then not Abort then
4844 -- Raise_From_Controlled_Operation (E);
4845 -- end if;
4847 if Built and then Present (Last_Fin) then
4848 Insert_After_And_Analyze (Last_Fin,
4849 Build_Raise_Statement (Fin_Data));
4850 end if;
4851 end Process_Transient_Objects;
4853 -- Local variables
4855 Loc : constant Source_Ptr := Sloc (N);
4856 Node_To_Wrap : constant Node_Id := Node_To_Be_Wrapped;
4857 First_Obj : Node_Id;
4858 Last_Obj : Node_Id;
4859 Mark_Id : Entity_Id;
4860 Target : Node_Id;
4862 -- Start of processing for Insert_Actions_In_Scope_Around
4864 begin
4865 if No (Act_Before) and then No (Act_After) and then No (Act_Cleanup) then
4866 return;
4867 end if;
4869 -- If the node to be wrapped is the trigger of an asynchronous select,
4870 -- it is not part of a statement list. The actions must be inserted
4871 -- before the select itself, which is part of some list of statements.
4872 -- Note that the triggering alternative includes the triggering
4873 -- statement and an optional statement list. If the node to be
4874 -- wrapped is part of that list, the normal insertion applies.
4876 if Nkind (Parent (Node_To_Wrap)) = N_Triggering_Alternative
4877 and then not Is_List_Member (Node_To_Wrap)
4878 then
4879 Target := Parent (Parent (Node_To_Wrap));
4880 else
4881 Target := N;
4882 end if;
4884 First_Obj := Target;
4885 Last_Obj := Target;
4887 -- Add all actions associated with a transient scope into the main tree.
4888 -- There are several scenarios here:
4890 -- +--- Before ----+ +----- After ---+
4891 -- 1) First_Obj ....... Target ........ Last_Obj
4893 -- 2) First_Obj ....... Target
4895 -- 3) Target ........ Last_Obj
4897 -- Flag declarations are inserted before the first object
4899 if Present (Act_Before) then
4900 First_Obj := First (Act_Before);
4901 Insert_List_Before (Target, Act_Before);
4902 end if;
4904 -- Finalization calls are inserted after the last object
4906 if Present (Act_After) then
4907 Last_Obj := Last (Act_After);
4908 Insert_List_After (Target, Act_After);
4909 end if;
4911 -- Mark and release the secondary stack when the context warrants it
4913 if Manage_SS then
4914 Mark_Id := Make_Temporary (Loc, 'M');
4916 -- Generate:
4917 -- Mnn : constant Mark_Id := SS_Mark;
4919 Insert_Before_And_Analyze
4920 (First_Obj, Build_SS_Mark_Call (Loc, Mark_Id));
4922 -- Generate:
4923 -- SS_Release (Mnn);
4925 Insert_After_And_Analyze
4926 (Last_Obj, Build_SS_Release_Call (Loc, Mark_Id));
4927 end if;
4929 -- Check for transient controlled objects associated with Target and
4930 -- generate the appropriate finalization actions for them.
4932 Process_Transient_Objects
4933 (First_Object => First_Obj,
4934 Last_Object => Last_Obj,
4935 Related_Node => Target);
4937 -- Reset the action lists
4939 Scope_Stack.Table
4940 (Scope_Stack.Last).Actions_To_Be_Wrapped (Before) := No_List;
4941 Scope_Stack.Table
4942 (Scope_Stack.Last).Actions_To_Be_Wrapped (After) := No_List;
4944 if Clean then
4945 Scope_Stack.Table
4946 (Scope_Stack.Last).Actions_To_Be_Wrapped (Cleanup) := No_List;
4947 end if;
4948 end Insert_Actions_In_Scope_Around;
4950 ------------------------------
4951 -- Is_Simple_Protected_Type --
4952 ------------------------------
4954 function Is_Simple_Protected_Type (T : Entity_Id) return Boolean is
4955 begin
4956 return
4957 Is_Protected_Type (T)
4958 and then not Uses_Lock_Free (T)
4959 and then not Has_Entries (T)
4960 and then Is_RTE (Find_Protection_Type (T), RE_Protection);
4961 end Is_Simple_Protected_Type;
4963 -----------------------
4964 -- Make_Adjust_Call --
4965 -----------------------
4967 function Make_Adjust_Call
4968 (Obj_Ref : Node_Id;
4969 Typ : Entity_Id;
4970 Skip_Self : Boolean := False) return Node_Id
4972 Loc : constant Source_Ptr := Sloc (Obj_Ref);
4973 Adj_Id : Entity_Id := Empty;
4974 Ref : Node_Id := Obj_Ref;
4975 Utyp : Entity_Id;
4977 begin
4978 -- Recover the proper type which contains Deep_Adjust
4980 if Is_Class_Wide_Type (Typ) then
4981 Utyp := Root_Type (Typ);
4982 else
4983 Utyp := Typ;
4984 end if;
4986 Utyp := Underlying_Type (Base_Type (Utyp));
4987 Set_Assignment_OK (Ref);
4989 -- Deal with untagged derivation of private views
4991 if Is_Untagged_Derivation (Typ) then
4992 Utyp := Underlying_Type (Root_Type (Base_Type (Typ)));
4993 Ref := Unchecked_Convert_To (Utyp, Ref);
4994 Set_Assignment_OK (Ref);
4995 end if;
4997 -- When dealing with the completion of a private type, use the base
4998 -- type instead.
5000 if Utyp /= Base_Type (Utyp) then
5001 pragma Assert (Is_Private_Type (Typ));
5003 Utyp := Base_Type (Utyp);
5004 Ref := Unchecked_Convert_To (Utyp, Ref);
5005 end if;
5007 if Skip_Self then
5008 if Has_Controlled_Component (Utyp) then
5009 if Is_Tagged_Type (Utyp) then
5010 Adj_Id := Find_Prim_Op (Utyp, TSS_Deep_Adjust);
5011 else
5012 Adj_Id := TSS (Utyp, TSS_Deep_Adjust);
5013 end if;
5014 end if;
5016 -- Class-wide types, interfaces and types with controlled components
5018 elsif Is_Class_Wide_Type (Typ)
5019 or else Is_Interface (Typ)
5020 or else Has_Controlled_Component (Utyp)
5021 then
5022 if Is_Tagged_Type (Utyp) then
5023 Adj_Id := Find_Prim_Op (Utyp, TSS_Deep_Adjust);
5024 else
5025 Adj_Id := TSS (Utyp, TSS_Deep_Adjust);
5026 end if;
5028 -- Derivations from [Limited_]Controlled
5030 elsif Is_Controlled (Utyp) then
5031 if Has_Controlled_Component (Utyp) then
5032 Adj_Id := Find_Prim_Op (Utyp, TSS_Deep_Adjust);
5033 else
5034 Adj_Id := Find_Prim_Op (Utyp, Name_Of (Adjust_Case));
5035 end if;
5037 -- Tagged types
5039 elsif Is_Tagged_Type (Utyp) then
5040 Adj_Id := Find_Prim_Op (Utyp, TSS_Deep_Adjust);
5042 else
5043 raise Program_Error;
5044 end if;
5046 if Present (Adj_Id) then
5048 -- If the object is unanalyzed, set its expected type for use in
5049 -- Convert_View in case an additional conversion is needed.
5051 if No (Etype (Ref))
5052 and then Nkind (Ref) /= N_Unchecked_Type_Conversion
5053 then
5054 Set_Etype (Ref, Typ);
5055 end if;
5057 -- The object reference may need another conversion depending on the
5058 -- type of the formal and that of the actual.
5060 if not Is_Class_Wide_Type (Typ) then
5061 Ref := Convert_View (Adj_Id, Ref);
5062 end if;
5064 return
5065 Make_Call (Loc,
5066 Proc_Id => Adj_Id,
5067 Param => New_Copy_Tree (Ref),
5068 Skip_Self => Skip_Self);
5069 else
5070 return Empty;
5071 end if;
5072 end Make_Adjust_Call;
5074 ----------------------
5075 -- Make_Attach_Call --
5076 ----------------------
5078 function Make_Attach_Call
5079 (Obj_Ref : Node_Id;
5080 Ptr_Typ : Entity_Id) return Node_Id
5082 pragma Assert (VM_Target /= No_VM);
5084 Loc : constant Source_Ptr := Sloc (Obj_Ref);
5085 begin
5086 return
5087 Make_Procedure_Call_Statement (Loc,
5088 Name =>
5089 New_Occurrence_Of (RTE (RE_Attach), Loc),
5090 Parameter_Associations => New_List (
5091 New_Occurrence_Of (Finalization_Master (Ptr_Typ), Loc),
5092 Unchecked_Convert_To (RTE (RE_Root_Controlled_Ptr), Obj_Ref)));
5093 end Make_Attach_Call;
5095 ----------------------
5096 -- Make_Detach_Call --
5097 ----------------------
5099 function Make_Detach_Call (Obj_Ref : Node_Id) return Node_Id is
5100 Loc : constant Source_Ptr := Sloc (Obj_Ref);
5102 begin
5103 return
5104 Make_Procedure_Call_Statement (Loc,
5105 Name =>
5106 New_Occurrence_Of (RTE (RE_Detach), Loc),
5107 Parameter_Associations => New_List (
5108 Unchecked_Convert_To (RTE (RE_Root_Controlled_Ptr), Obj_Ref)));
5109 end Make_Detach_Call;
5111 ---------------
5112 -- Make_Call --
5113 ---------------
5115 function Make_Call
5116 (Loc : Source_Ptr;
5117 Proc_Id : Entity_Id;
5118 Param : Node_Id;
5119 Skip_Self : Boolean := False) return Node_Id
5121 Params : constant List_Id := New_List (Param);
5123 begin
5124 -- Do not apply the controlled action to the object itself by signaling
5125 -- the related routine to avoid self.
5127 if Skip_Self then
5128 Append_To (Params, New_Occurrence_Of (Standard_False, Loc));
5129 end if;
5131 return
5132 Make_Procedure_Call_Statement (Loc,
5133 Name => New_Occurrence_Of (Proc_Id, Loc),
5134 Parameter_Associations => Params);
5135 end Make_Call;
5137 --------------------------
5138 -- Make_Deep_Array_Body --
5139 --------------------------
5141 function Make_Deep_Array_Body
5142 (Prim : Final_Primitives;
5143 Typ : Entity_Id) return List_Id
5145 function Build_Adjust_Or_Finalize_Statements
5146 (Typ : Entity_Id) return List_Id;
5147 -- Create the statements necessary to adjust or finalize an array of
5148 -- controlled elements. Generate:
5150 -- declare
5151 -- Abort : constant Boolean := Triggered_By_Abort;
5152 -- <or>
5153 -- Abort : constant Boolean := False; -- no abort
5155 -- E : Exception_Occurrence;
5156 -- Raised : Boolean := False;
5158 -- begin
5159 -- for J1 in [reverse] Typ'First (1) .. Typ'Last (1) loop
5160 -- ^-- in the finalization case
5161 -- ...
5162 -- for Jn in [reverse] Typ'First (n) .. Typ'Last (n) loop
5163 -- begin
5164 -- [Deep_]Adjust / Finalize (V (J1, ..., Jn));
5166 -- exception
5167 -- when others =>
5168 -- if not Raised then
5169 -- Raised := True;
5170 -- Save_Occurrence (E, Get_Current_Excep.all.all);
5171 -- end if;
5172 -- end;
5173 -- end loop;
5174 -- ...
5175 -- end loop;
5177 -- if Raised and then not Abort then
5178 -- Raise_From_Controlled_Operation (E);
5179 -- end if;
5180 -- end;
5182 function Build_Initialize_Statements (Typ : Entity_Id) return List_Id;
5183 -- Create the statements necessary to initialize an array of controlled
5184 -- elements. Include a mechanism to carry out partial finalization if an
5185 -- exception occurs. Generate:
5187 -- declare
5188 -- Counter : Integer := 0;
5190 -- begin
5191 -- for J1 in V'Range (1) loop
5192 -- ...
5193 -- for JN in V'Range (N) loop
5194 -- begin
5195 -- [Deep_]Initialize (V (J1, ..., JN));
5197 -- Counter := Counter + 1;
5199 -- exception
5200 -- when others =>
5201 -- declare
5202 -- Abort : constant Boolean := Triggered_By_Abort;
5203 -- <or>
5204 -- Abort : constant Boolean := False; -- no abort
5205 -- E : Exception_Occurence;
5206 -- Raised : Boolean := False;
5208 -- begin
5209 -- Counter :=
5210 -- V'Length (1) *
5211 -- V'Length (2) *
5212 -- ...
5213 -- V'Length (N) - Counter;
5215 -- for F1 in reverse V'Range (1) loop
5216 -- ...
5217 -- for FN in reverse V'Range (N) loop
5218 -- if Counter > 0 then
5219 -- Counter := Counter - 1;
5220 -- else
5221 -- begin
5222 -- [Deep_]Finalize (V (F1, ..., FN));
5224 -- exception
5225 -- when others =>
5226 -- if not Raised then
5227 -- Raised := True;
5228 -- Save_Occurrence (E,
5229 -- Get_Current_Excep.all.all);
5230 -- end if;
5231 -- end;
5232 -- end if;
5233 -- end loop;
5234 -- ...
5235 -- end loop;
5236 -- end;
5238 -- if Raised and then not Abort then
5239 -- Raise_From_Controlled_Operation (E);
5240 -- end if;
5242 -- raise;
5243 -- end;
5244 -- end loop;
5245 -- end loop;
5246 -- end;
5248 function New_References_To
5249 (L : List_Id;
5250 Loc : Source_Ptr) return List_Id;
5251 -- Given a list of defining identifiers, return a list of references to
5252 -- the original identifiers, in the same order as they appear.
5254 -----------------------------------------
5255 -- Build_Adjust_Or_Finalize_Statements --
5256 -----------------------------------------
5258 function Build_Adjust_Or_Finalize_Statements
5259 (Typ : Entity_Id) return List_Id
5261 Comp_Typ : constant Entity_Id := Component_Type (Typ);
5262 Index_List : constant List_Id := New_List;
5263 Loc : constant Source_Ptr := Sloc (Typ);
5264 Num_Dims : constant Int := Number_Dimensions (Typ);
5265 Finalizer_Decls : List_Id := No_List;
5266 Finalizer_Data : Finalization_Exception_Data;
5267 Call : Node_Id;
5268 Comp_Ref : Node_Id;
5269 Core_Loop : Node_Id;
5270 Dim : Int;
5271 J : Entity_Id;
5272 Loop_Id : Entity_Id;
5273 Stmts : List_Id;
5275 Exceptions_OK : constant Boolean :=
5276 not Restriction_Active (No_Exception_Propagation);
5278 procedure Build_Indexes;
5279 -- Generate the indexes used in the dimension loops
5281 -------------------
5282 -- Build_Indexes --
5283 -------------------
5285 procedure Build_Indexes is
5286 begin
5287 -- Generate the following identifiers:
5288 -- Jnn - for initialization
5290 for Dim in 1 .. Num_Dims loop
5291 Append_To (Index_List,
5292 Make_Defining_Identifier (Loc, New_External_Name ('J', Dim)));
5293 end loop;
5294 end Build_Indexes;
5296 -- Start of processing for Build_Adjust_Or_Finalize_Statements
5298 begin
5299 Finalizer_Decls := New_List;
5301 Build_Indexes;
5302 Build_Object_Declarations (Finalizer_Data, Finalizer_Decls, Loc);
5304 Comp_Ref :=
5305 Make_Indexed_Component (Loc,
5306 Prefix => Make_Identifier (Loc, Name_V),
5307 Expressions => New_References_To (Index_List, Loc));
5308 Set_Etype (Comp_Ref, Comp_Typ);
5310 -- Generate:
5311 -- [Deep_]Adjust (V (J1, ..., JN))
5313 if Prim = Adjust_Case then
5314 Call := Make_Adjust_Call (Obj_Ref => Comp_Ref, Typ => Comp_Typ);
5316 -- Generate:
5317 -- [Deep_]Finalize (V (J1, ..., JN))
5319 else pragma Assert (Prim = Finalize_Case);
5320 Call := Make_Final_Call (Obj_Ref => Comp_Ref, Typ => Comp_Typ);
5321 end if;
5323 -- Generate the block which houses the adjust or finalize call:
5325 -- <adjust or finalize call>; -- No_Exception_Propagation
5327 -- begin -- Exception handlers allowed
5328 -- <adjust or finalize call>
5330 -- exception
5331 -- when others =>
5332 -- if not Raised then
5333 -- Raised := True;
5334 -- Save_Occurrence (E, Get_Current_Excep.all.all);
5335 -- end if;
5336 -- end;
5338 if Exceptions_OK then
5339 Core_Loop :=
5340 Make_Block_Statement (Loc,
5341 Handled_Statement_Sequence =>
5342 Make_Handled_Sequence_Of_Statements (Loc,
5343 Statements => New_List (Call),
5344 Exception_Handlers => New_List (
5345 Build_Exception_Handler (Finalizer_Data))));
5346 else
5347 Core_Loop := Call;
5348 end if;
5350 -- Generate the dimension loops starting from the innermost one
5352 -- for Jnn in [reverse] V'Range (Dim) loop
5353 -- <core loop>
5354 -- end loop;
5356 J := Last (Index_List);
5357 Dim := Num_Dims;
5358 while Present (J) and then Dim > 0 loop
5359 Loop_Id := J;
5360 Prev (J);
5361 Remove (Loop_Id);
5363 Core_Loop :=
5364 Make_Loop_Statement (Loc,
5365 Iteration_Scheme =>
5366 Make_Iteration_Scheme (Loc,
5367 Loop_Parameter_Specification =>
5368 Make_Loop_Parameter_Specification (Loc,
5369 Defining_Identifier => Loop_Id,
5370 Discrete_Subtype_Definition =>
5371 Make_Attribute_Reference (Loc,
5372 Prefix => Make_Identifier (Loc, Name_V),
5373 Attribute_Name => Name_Range,
5374 Expressions => New_List (
5375 Make_Integer_Literal (Loc, Dim))),
5377 Reverse_Present => Prim = Finalize_Case)),
5379 Statements => New_List (Core_Loop),
5380 End_Label => Empty);
5382 Dim := Dim - 1;
5383 end loop;
5385 -- Generate the block which contains the core loop, the declarations
5386 -- of the abort flag, the exception occurrence, the raised flag and
5387 -- the conditional raise:
5389 -- declare
5390 -- Abort : constant Boolean := Triggered_By_Abort;
5391 -- <or>
5392 -- Abort : constant Boolean := False; -- no abort
5394 -- E : Exception_Occurrence;
5395 -- Raised : Boolean := False;
5397 -- begin
5398 -- <core loop>
5400 -- if Raised and then not Abort then -- Expection handlers OK
5401 -- Raise_From_Controlled_Operation (E);
5402 -- end if;
5403 -- end;
5405 Stmts := New_List (Core_Loop);
5407 if Exceptions_OK then
5408 Append_To (Stmts,
5409 Build_Raise_Statement (Finalizer_Data));
5410 end if;
5412 return
5413 New_List (
5414 Make_Block_Statement (Loc,
5415 Declarations =>
5416 Finalizer_Decls,
5417 Handled_Statement_Sequence =>
5418 Make_Handled_Sequence_Of_Statements (Loc, Stmts)));
5419 end Build_Adjust_Or_Finalize_Statements;
5421 ---------------------------------
5422 -- Build_Initialize_Statements --
5423 ---------------------------------
5425 function Build_Initialize_Statements (Typ : Entity_Id) return List_Id is
5426 Comp_Typ : constant Entity_Id := Component_Type (Typ);
5427 Final_List : constant List_Id := New_List;
5428 Index_List : constant List_Id := New_List;
5429 Loc : constant Source_Ptr := Sloc (Typ);
5430 Num_Dims : constant Int := Number_Dimensions (Typ);
5431 Counter_Id : Entity_Id;
5432 Dim : Int;
5433 F : Node_Id;
5434 Fin_Stmt : Node_Id;
5435 Final_Block : Node_Id;
5436 Final_Loop : Node_Id;
5437 Finalizer_Data : Finalization_Exception_Data;
5438 Finalizer_Decls : List_Id := No_List;
5439 Init_Loop : Node_Id;
5440 J : Node_Id;
5441 Loop_Id : Node_Id;
5442 Stmts : List_Id;
5444 Exceptions_OK : constant Boolean :=
5445 not Restriction_Active (No_Exception_Propagation);
5447 function Build_Counter_Assignment return Node_Id;
5448 -- Generate the following assignment:
5449 -- Counter := V'Length (1) *
5450 -- ...
5451 -- V'Length (N) - Counter;
5453 function Build_Finalization_Call return Node_Id;
5454 -- Generate a deep finalization call for an array element
5456 procedure Build_Indexes;
5457 -- Generate the initialization and finalization indexes used in the
5458 -- dimension loops.
5460 function Build_Initialization_Call return Node_Id;
5461 -- Generate a deep initialization call for an array element
5463 ------------------------------
5464 -- Build_Counter_Assignment --
5465 ------------------------------
5467 function Build_Counter_Assignment return Node_Id is
5468 Dim : Int;
5469 Expr : Node_Id;
5471 begin
5472 -- Start from the first dimension and generate:
5473 -- V'Length (1)
5475 Dim := 1;
5476 Expr :=
5477 Make_Attribute_Reference (Loc,
5478 Prefix => Make_Identifier (Loc, Name_V),
5479 Attribute_Name => Name_Length,
5480 Expressions => New_List (Make_Integer_Literal (Loc, Dim)));
5482 -- Process the rest of the dimensions, generate:
5483 -- Expr * V'Length (N)
5485 Dim := Dim + 1;
5486 while Dim <= Num_Dims loop
5487 Expr :=
5488 Make_Op_Multiply (Loc,
5489 Left_Opnd => Expr,
5490 Right_Opnd =>
5491 Make_Attribute_Reference (Loc,
5492 Prefix => Make_Identifier (Loc, Name_V),
5493 Attribute_Name => Name_Length,
5494 Expressions => New_List (
5495 Make_Integer_Literal (Loc, Dim))));
5497 Dim := Dim + 1;
5498 end loop;
5500 -- Generate:
5501 -- Counter := Expr - Counter;
5503 return
5504 Make_Assignment_Statement (Loc,
5505 Name => New_Occurrence_Of (Counter_Id, Loc),
5506 Expression =>
5507 Make_Op_Subtract (Loc,
5508 Left_Opnd => Expr,
5509 Right_Opnd => New_Occurrence_Of (Counter_Id, Loc)));
5510 end Build_Counter_Assignment;
5512 -----------------------------
5513 -- Build_Finalization_Call --
5514 -----------------------------
5516 function Build_Finalization_Call return Node_Id is
5517 Comp_Ref : constant Node_Id :=
5518 Make_Indexed_Component (Loc,
5519 Prefix => Make_Identifier (Loc, Name_V),
5520 Expressions => New_References_To (Final_List, Loc));
5522 begin
5523 Set_Etype (Comp_Ref, Comp_Typ);
5525 -- Generate:
5526 -- [Deep_]Finalize (V);
5528 return Make_Final_Call (Obj_Ref => Comp_Ref, Typ => Comp_Typ);
5529 end Build_Finalization_Call;
5531 -------------------
5532 -- Build_Indexes --
5533 -------------------
5535 procedure Build_Indexes is
5536 begin
5537 -- Generate the following identifiers:
5538 -- Jnn - for initialization
5539 -- Fnn - for finalization
5541 for Dim in 1 .. Num_Dims loop
5542 Append_To (Index_List,
5543 Make_Defining_Identifier (Loc, New_External_Name ('J', Dim)));
5545 Append_To (Final_List,
5546 Make_Defining_Identifier (Loc, New_External_Name ('F', Dim)));
5547 end loop;
5548 end Build_Indexes;
5550 -------------------------------
5551 -- Build_Initialization_Call --
5552 -------------------------------
5554 function Build_Initialization_Call return Node_Id is
5555 Comp_Ref : constant Node_Id :=
5556 Make_Indexed_Component (Loc,
5557 Prefix => Make_Identifier (Loc, Name_V),
5558 Expressions => New_References_To (Index_List, Loc));
5560 begin
5561 Set_Etype (Comp_Ref, Comp_Typ);
5563 -- Generate:
5564 -- [Deep_]Initialize (V (J1, ..., JN));
5566 return Make_Init_Call (Obj_Ref => Comp_Ref, Typ => Comp_Typ);
5567 end Build_Initialization_Call;
5569 -- Start of processing for Build_Initialize_Statements
5571 begin
5572 Counter_Id := Make_Temporary (Loc, 'C');
5573 Finalizer_Decls := New_List;
5575 Build_Indexes;
5576 Build_Object_Declarations (Finalizer_Data, Finalizer_Decls, Loc);
5578 -- Generate the block which houses the finalization call, the index
5579 -- guard and the handler which triggers Program_Error later on.
5581 -- if Counter > 0 then
5582 -- Counter := Counter - 1;
5583 -- else
5584 -- [Deep_]Finalize (V (F1, ..., FN)); -- No_Except_Propagation
5586 -- begin -- Exceptions allowed
5587 -- [Deep_]Finalize (V (F1, ..., FN));
5588 -- exception
5589 -- when others =>
5590 -- if not Raised then
5591 -- Raised := True;
5592 -- Save_Occurrence (E, Get_Current_Excep.all.all);
5593 -- end if;
5594 -- end;
5595 -- end if;
5597 if Exceptions_OK then
5598 Fin_Stmt :=
5599 Make_Block_Statement (Loc,
5600 Handled_Statement_Sequence =>
5601 Make_Handled_Sequence_Of_Statements (Loc,
5602 Statements => New_List (Build_Finalization_Call),
5603 Exception_Handlers => New_List (
5604 Build_Exception_Handler (Finalizer_Data))));
5605 else
5606 Fin_Stmt := Build_Finalization_Call;
5607 end if;
5609 -- This is the core of the loop, the dimension iterators are added
5610 -- one by one in reverse.
5612 Final_Loop :=
5613 Make_If_Statement (Loc,
5614 Condition =>
5615 Make_Op_Gt (Loc,
5616 Left_Opnd => New_Occurrence_Of (Counter_Id, Loc),
5617 Right_Opnd => Make_Integer_Literal (Loc, 0)),
5619 Then_Statements => New_List (
5620 Make_Assignment_Statement (Loc,
5621 Name => New_Occurrence_Of (Counter_Id, Loc),
5622 Expression =>
5623 Make_Op_Subtract (Loc,
5624 Left_Opnd => New_Occurrence_Of (Counter_Id, Loc),
5625 Right_Opnd => Make_Integer_Literal (Loc, 1)))),
5627 Else_Statements => New_List (Fin_Stmt));
5629 -- Generate all finalization loops starting from the innermost
5630 -- dimension.
5632 -- for Fnn in reverse V'Range (Dim) loop
5633 -- <final loop>
5634 -- end loop;
5636 F := Last (Final_List);
5637 Dim := Num_Dims;
5638 while Present (F) and then Dim > 0 loop
5639 Loop_Id := F;
5640 Prev (F);
5641 Remove (Loop_Id);
5643 Final_Loop :=
5644 Make_Loop_Statement (Loc,
5645 Iteration_Scheme =>
5646 Make_Iteration_Scheme (Loc,
5647 Loop_Parameter_Specification =>
5648 Make_Loop_Parameter_Specification (Loc,
5649 Defining_Identifier => Loop_Id,
5650 Discrete_Subtype_Definition =>
5651 Make_Attribute_Reference (Loc,
5652 Prefix => Make_Identifier (Loc, Name_V),
5653 Attribute_Name => Name_Range,
5654 Expressions => New_List (
5655 Make_Integer_Literal (Loc, Dim))),
5657 Reverse_Present => True)),
5659 Statements => New_List (Final_Loop),
5660 End_Label => Empty);
5662 Dim := Dim - 1;
5663 end loop;
5665 -- Generate the block which contains the finalization loops, the
5666 -- declarations of the abort flag, the exception occurrence, the
5667 -- raised flag and the conditional raise.
5669 -- declare
5670 -- Abort : constant Boolean := Triggered_By_Abort;
5671 -- <or>
5672 -- Abort : constant Boolean := False; -- no abort
5674 -- E : Exception_Occurrence;
5675 -- Raised : Boolean := False;
5677 -- begin
5678 -- Counter :=
5679 -- V'Length (1) *
5680 -- ...
5681 -- V'Length (N) - Counter;
5683 -- <final loop>
5685 -- if Raised and then not Abort then -- Exception handlers OK
5686 -- Raise_From_Controlled_Operation (E);
5687 -- end if;
5689 -- raise; -- Exception handlers OK
5690 -- end;
5692 Stmts := New_List (Build_Counter_Assignment, Final_Loop);
5694 if Exceptions_OK then
5695 Append_To (Stmts,
5696 Build_Raise_Statement (Finalizer_Data));
5697 Append_To (Stmts, Make_Raise_Statement (Loc));
5698 end if;
5700 Final_Block :=
5701 Make_Block_Statement (Loc,
5702 Declarations =>
5703 Finalizer_Decls,
5704 Handled_Statement_Sequence =>
5705 Make_Handled_Sequence_Of_Statements (Loc, Statements => Stmts));
5707 -- Generate the block which contains the initialization call and
5708 -- the partial finalization code.
5710 -- begin
5711 -- [Deep_]Initialize (V (J1, ..., JN));
5713 -- Counter := Counter + 1;
5715 -- exception
5716 -- when others =>
5717 -- <finalization code>
5718 -- end;
5720 Init_Loop :=
5721 Make_Block_Statement (Loc,
5722 Handled_Statement_Sequence =>
5723 Make_Handled_Sequence_Of_Statements (Loc,
5724 Statements => New_List (Build_Initialization_Call),
5725 Exception_Handlers => New_List (
5726 Make_Exception_Handler (Loc,
5727 Exception_Choices => New_List (Make_Others_Choice (Loc)),
5728 Statements => New_List (Final_Block)))));
5730 Append_To (Statements (Handled_Statement_Sequence (Init_Loop)),
5731 Make_Assignment_Statement (Loc,
5732 Name => New_Occurrence_Of (Counter_Id, Loc),
5733 Expression =>
5734 Make_Op_Add (Loc,
5735 Left_Opnd => New_Occurrence_Of (Counter_Id, Loc),
5736 Right_Opnd => Make_Integer_Literal (Loc, 1))));
5738 -- Generate all initialization loops starting from the innermost
5739 -- dimension.
5741 -- for Jnn in V'Range (Dim) loop
5742 -- <init loop>
5743 -- end loop;
5745 J := Last (Index_List);
5746 Dim := Num_Dims;
5747 while Present (J) and then Dim > 0 loop
5748 Loop_Id := J;
5749 Prev (J);
5750 Remove (Loop_Id);
5752 Init_Loop :=
5753 Make_Loop_Statement (Loc,
5754 Iteration_Scheme =>
5755 Make_Iteration_Scheme (Loc,
5756 Loop_Parameter_Specification =>
5757 Make_Loop_Parameter_Specification (Loc,
5758 Defining_Identifier => Loop_Id,
5759 Discrete_Subtype_Definition =>
5760 Make_Attribute_Reference (Loc,
5761 Prefix => Make_Identifier (Loc, Name_V),
5762 Attribute_Name => Name_Range,
5763 Expressions => New_List (
5764 Make_Integer_Literal (Loc, Dim))))),
5766 Statements => New_List (Init_Loop),
5767 End_Label => Empty);
5769 Dim := Dim - 1;
5770 end loop;
5772 -- Generate the block which contains the counter variable and the
5773 -- initialization loops.
5775 -- declare
5776 -- Counter : Integer := 0;
5777 -- begin
5778 -- <init loop>
5779 -- end;
5781 return
5782 New_List (
5783 Make_Block_Statement (Loc,
5784 Declarations => New_List (
5785 Make_Object_Declaration (Loc,
5786 Defining_Identifier => Counter_Id,
5787 Object_Definition =>
5788 New_Occurrence_Of (Standard_Integer, Loc),
5789 Expression => Make_Integer_Literal (Loc, 0))),
5791 Handled_Statement_Sequence =>
5792 Make_Handled_Sequence_Of_Statements (Loc,
5793 Statements => New_List (Init_Loop))));
5794 end Build_Initialize_Statements;
5796 -----------------------
5797 -- New_References_To --
5798 -----------------------
5800 function New_References_To
5801 (L : List_Id;
5802 Loc : Source_Ptr) return List_Id
5804 Refs : constant List_Id := New_List;
5805 Id : Node_Id;
5807 begin
5808 Id := First (L);
5809 while Present (Id) loop
5810 Append_To (Refs, New_Occurrence_Of (Id, Loc));
5811 Next (Id);
5812 end loop;
5814 return Refs;
5815 end New_References_To;
5817 -- Start of processing for Make_Deep_Array_Body
5819 begin
5820 case Prim is
5821 when Address_Case =>
5822 return Make_Finalize_Address_Stmts (Typ);
5824 when Adjust_Case |
5825 Finalize_Case =>
5826 return Build_Adjust_Or_Finalize_Statements (Typ);
5828 when Initialize_Case =>
5829 return Build_Initialize_Statements (Typ);
5830 end case;
5831 end Make_Deep_Array_Body;
5833 --------------------
5834 -- Make_Deep_Proc --
5835 --------------------
5837 function Make_Deep_Proc
5838 (Prim : Final_Primitives;
5839 Typ : Entity_Id;
5840 Stmts : List_Id) return Entity_Id
5842 Loc : constant Source_Ptr := Sloc (Typ);
5843 Formals : List_Id;
5844 Proc_Id : Entity_Id;
5846 begin
5847 -- Create the object formal, generate:
5848 -- V : System.Address
5850 if Prim = Address_Case then
5851 Formals := New_List (
5852 Make_Parameter_Specification (Loc,
5853 Defining_Identifier => Make_Defining_Identifier (Loc, Name_V),
5854 Parameter_Type =>
5855 New_Occurrence_Of (RTE (RE_Address), Loc)));
5857 -- Default case
5859 else
5860 -- V : in out Typ
5862 Formals := New_List (
5863 Make_Parameter_Specification (Loc,
5864 Defining_Identifier => Make_Defining_Identifier (Loc, Name_V),
5865 In_Present => True,
5866 Out_Present => True,
5867 Parameter_Type => New_Occurrence_Of (Typ, Loc)));
5869 -- F : Boolean := True
5871 if Prim = Adjust_Case
5872 or else Prim = Finalize_Case
5873 then
5874 Append_To (Formals,
5875 Make_Parameter_Specification (Loc,
5876 Defining_Identifier => Make_Defining_Identifier (Loc, Name_F),
5877 Parameter_Type =>
5878 New_Occurrence_Of (Standard_Boolean, Loc),
5879 Expression =>
5880 New_Occurrence_Of (Standard_True, Loc)));
5881 end if;
5882 end if;
5884 Proc_Id :=
5885 Make_Defining_Identifier (Loc,
5886 Chars => Make_TSS_Name (Typ, Deep_Name_Of (Prim)));
5888 -- Generate:
5889 -- procedure Deep_Initialize / Adjust / Finalize (V : in out <typ>) is
5890 -- begin
5891 -- <stmts>
5892 -- exception -- Finalize and Adjust cases only
5893 -- raise Program_Error;
5894 -- end Deep_Initialize / Adjust / Finalize;
5896 -- or
5898 -- procedure Finalize_Address (V : System.Address) is
5899 -- begin
5900 -- <stmts>
5901 -- end Finalize_Address;
5903 Discard_Node (
5904 Make_Subprogram_Body (Loc,
5905 Specification =>
5906 Make_Procedure_Specification (Loc,
5907 Defining_Unit_Name => Proc_Id,
5908 Parameter_Specifications => Formals),
5910 Declarations => Empty_List,
5912 Handled_Statement_Sequence =>
5913 Make_Handled_Sequence_Of_Statements (Loc, Statements => Stmts)));
5915 return Proc_Id;
5916 end Make_Deep_Proc;
5918 ---------------------------
5919 -- Make_Deep_Record_Body --
5920 ---------------------------
5922 function Make_Deep_Record_Body
5923 (Prim : Final_Primitives;
5924 Typ : Entity_Id;
5925 Is_Local : Boolean := False) return List_Id
5927 function Build_Adjust_Statements (Typ : Entity_Id) return List_Id;
5928 -- Build the statements necessary to adjust a record type. The type may
5929 -- have discriminants and contain variant parts. Generate:
5931 -- begin
5932 -- begin
5933 -- [Deep_]Adjust (V.Comp_1);
5934 -- exception
5935 -- when Id : others =>
5936 -- if not Raised then
5937 -- Raised := True;
5938 -- Save_Occurrence (E, Get_Current_Excep.all.all);
5939 -- end if;
5940 -- end;
5941 -- . . .
5942 -- begin
5943 -- [Deep_]Adjust (V.Comp_N);
5944 -- exception
5945 -- when Id : others =>
5946 -- if not Raised then
5947 -- Raised := True;
5948 -- Save_Occurrence (E, Get_Current_Excep.all.all);
5949 -- end if;
5950 -- end;
5952 -- begin
5953 -- Deep_Adjust (V._parent, False); -- If applicable
5954 -- exception
5955 -- when Id : others =>
5956 -- if not Raised then
5957 -- Raised := True;
5958 -- Save_Occurrence (E, Get_Current_Excep.all.all);
5959 -- end if;
5960 -- end;
5962 -- if F then
5963 -- begin
5964 -- Adjust (V); -- If applicable
5965 -- exception
5966 -- when others =>
5967 -- if not Raised then
5968 -- Raised := True;
5969 -- Save_Occurence (E, Get_Current_Excep.all.all);
5970 -- end if;
5971 -- end;
5972 -- end if;
5974 -- if Raised and then not Abort then
5975 -- Raise_From_Controlled_Operation (E);
5976 -- end if;
5977 -- end;
5979 function Build_Finalize_Statements (Typ : Entity_Id) return List_Id;
5980 -- Build the statements necessary to finalize a record type. The type
5981 -- may have discriminants and contain variant parts. Generate:
5983 -- declare
5984 -- Abort : constant Boolean := Triggered_By_Abort;
5985 -- <or>
5986 -- Abort : constant Boolean := False; -- no abort
5987 -- E : Exception_Occurence;
5988 -- Raised : Boolean := False;
5990 -- begin
5991 -- if F then
5992 -- begin
5993 -- Finalize (V); -- If applicable
5994 -- exception
5995 -- when others =>
5996 -- if not Raised then
5997 -- Raised := True;
5998 -- Save_Occurence (E, Get_Current_Excep.all.all);
5999 -- end if;
6000 -- end;
6001 -- end if;
6003 -- case Variant_1 is
6004 -- when Value_1 =>
6005 -- case State_Counter_N => -- If Is_Local is enabled
6006 -- when N => .
6007 -- goto LN; .
6008 -- ... .
6009 -- when 1 => .
6010 -- goto L1; .
6011 -- when others => .
6012 -- goto L0; .
6013 -- end case; .
6015 -- <<LN>> -- If Is_Local is enabled
6016 -- begin
6017 -- [Deep_]Finalize (V.Comp_N);
6018 -- exception
6019 -- when others =>
6020 -- if not Raised then
6021 -- Raised := True;
6022 -- Save_Occurence (E, Get_Current_Excep.all.all);
6023 -- end if;
6024 -- end;
6025 -- . . .
6026 -- <<L1>>
6027 -- begin
6028 -- [Deep_]Finalize (V.Comp_1);
6029 -- exception
6030 -- when others =>
6031 -- if not Raised then
6032 -- Raised := True;
6033 -- Save_Occurence (E, Get_Current_Excep.all.all);
6034 -- end if;
6035 -- end;
6036 -- <<L0>>
6037 -- end case;
6039 -- case State_Counter_1 => -- If Is_Local is enabled
6040 -- when M => .
6041 -- goto LM; .
6042 -- ...
6044 -- begin
6045 -- Deep_Finalize (V._parent, False); -- If applicable
6046 -- exception
6047 -- when Id : others =>
6048 -- if not Raised then
6049 -- Raised := True;
6050 -- Save_Occurrence (E, Get_Current_Excep.all.all);
6051 -- end if;
6052 -- end;
6054 -- if Raised and then not Abort then
6055 -- Raise_From_Controlled_Operation (E);
6056 -- end if;
6057 -- end;
6059 function Parent_Field_Type (Typ : Entity_Id) return Entity_Id;
6060 -- Given a derived tagged type Typ, traverse all components, find field
6061 -- _parent and return its type.
6063 procedure Preprocess_Components
6064 (Comps : Node_Id;
6065 Num_Comps : out Int;
6066 Has_POC : out Boolean);
6067 -- Examine all components in component list Comps, count all controlled
6068 -- components and determine whether at least one of them is per-object
6069 -- constrained. Component _parent is always skipped.
6071 -----------------------------
6072 -- Build_Adjust_Statements --
6073 -----------------------------
6075 function Build_Adjust_Statements (Typ : Entity_Id) return List_Id is
6076 Loc : constant Source_Ptr := Sloc (Typ);
6077 Typ_Def : constant Node_Id := Type_Definition (Parent (Typ));
6078 Bod_Stmts : List_Id;
6079 Finalizer_Data : Finalization_Exception_Data;
6080 Finalizer_Decls : List_Id := No_List;
6081 Rec_Def : Node_Id;
6082 Var_Case : Node_Id;
6084 Exceptions_OK : constant Boolean :=
6085 not Restriction_Active (No_Exception_Propagation);
6087 function Process_Component_List_For_Adjust
6088 (Comps : Node_Id) return List_Id;
6089 -- Build all necessary adjust statements for a single component list
6091 ---------------------------------------
6092 -- Process_Component_List_For_Adjust --
6093 ---------------------------------------
6095 function Process_Component_List_For_Adjust
6096 (Comps : Node_Id) return List_Id
6098 Stmts : constant List_Id := New_List;
6099 Decl : Node_Id;
6100 Decl_Id : Entity_Id;
6101 Decl_Typ : Entity_Id;
6102 Has_POC : Boolean;
6103 Num_Comps : Int;
6105 procedure Process_Component_For_Adjust (Decl : Node_Id);
6106 -- Process the declaration of a single controlled component
6108 ----------------------------------
6109 -- Process_Component_For_Adjust --
6110 ----------------------------------
6112 procedure Process_Component_For_Adjust (Decl : Node_Id) is
6113 Id : constant Entity_Id := Defining_Identifier (Decl);
6114 Typ : constant Entity_Id := Etype (Id);
6115 Adj_Stmt : Node_Id;
6117 begin
6118 -- Generate:
6119 -- [Deep_]Adjust (V.Id); -- No_Exception_Propagation
6121 -- begin -- Exception handlers allowed
6122 -- [Deep_]Adjust (V.Id);
6123 -- exception
6124 -- when others =>
6125 -- if not Raised then
6126 -- Raised := True;
6127 -- Save_Occurrence (E, Get_Current_Excep.all.all);
6128 -- end if;
6129 -- end;
6131 Adj_Stmt :=
6132 Make_Adjust_Call (
6133 Obj_Ref =>
6134 Make_Selected_Component (Loc,
6135 Prefix => Make_Identifier (Loc, Name_V),
6136 Selector_Name => Make_Identifier (Loc, Chars (Id))),
6137 Typ => Typ);
6139 if Exceptions_OK then
6140 Adj_Stmt :=
6141 Make_Block_Statement (Loc,
6142 Handled_Statement_Sequence =>
6143 Make_Handled_Sequence_Of_Statements (Loc,
6144 Statements => New_List (Adj_Stmt),
6145 Exception_Handlers => New_List (
6146 Build_Exception_Handler (Finalizer_Data))));
6147 end if;
6149 Append_To (Stmts, Adj_Stmt);
6150 end Process_Component_For_Adjust;
6152 -- Start of processing for Process_Component_List_For_Adjust
6154 begin
6155 -- Perform an initial check, determine the number of controlled
6156 -- components in the current list and whether at least one of them
6157 -- is per-object constrained.
6159 Preprocess_Components (Comps, Num_Comps, Has_POC);
6161 -- The processing in this routine is done in the following order:
6162 -- 1) Regular components
6163 -- 2) Per-object constrained components
6164 -- 3) Variant parts
6166 if Num_Comps > 0 then
6168 -- Process all regular components in order of declarations
6170 Decl := First_Non_Pragma (Component_Items (Comps));
6171 while Present (Decl) loop
6172 Decl_Id := Defining_Identifier (Decl);
6173 Decl_Typ := Etype (Decl_Id);
6175 -- Skip _parent as well as per-object constrained components
6177 if Chars (Decl_Id) /= Name_uParent
6178 and then Needs_Finalization (Decl_Typ)
6179 then
6180 if Has_Access_Constraint (Decl_Id)
6181 and then No (Expression (Decl))
6182 then
6183 null;
6184 else
6185 Process_Component_For_Adjust (Decl);
6186 end if;
6187 end if;
6189 Next_Non_Pragma (Decl);
6190 end loop;
6192 -- Process all per-object constrained components in order of
6193 -- declarations.
6195 if Has_POC then
6196 Decl := First_Non_Pragma (Component_Items (Comps));
6197 while Present (Decl) loop
6198 Decl_Id := Defining_Identifier (Decl);
6199 Decl_Typ := Etype (Decl_Id);
6201 -- Skip _parent
6203 if Chars (Decl_Id) /= Name_uParent
6204 and then Needs_Finalization (Decl_Typ)
6205 and then Has_Access_Constraint (Decl_Id)
6206 and then No (Expression (Decl))
6207 then
6208 Process_Component_For_Adjust (Decl);
6209 end if;
6211 Next_Non_Pragma (Decl);
6212 end loop;
6213 end if;
6214 end if;
6216 -- Process all variants, if any
6218 Var_Case := Empty;
6219 if Present (Variant_Part (Comps)) then
6220 declare
6221 Var_Alts : constant List_Id := New_List;
6222 Var : Node_Id;
6224 begin
6225 Var := First_Non_Pragma (Variants (Variant_Part (Comps)));
6226 while Present (Var) loop
6228 -- Generate:
6229 -- when <discrete choices> =>
6230 -- <adjust statements>
6232 Append_To (Var_Alts,
6233 Make_Case_Statement_Alternative (Loc,
6234 Discrete_Choices =>
6235 New_Copy_List (Discrete_Choices (Var)),
6236 Statements =>
6237 Process_Component_List_For_Adjust (
6238 Component_List (Var))));
6240 Next_Non_Pragma (Var);
6241 end loop;
6243 -- Generate:
6244 -- case V.<discriminant> is
6245 -- when <discrete choices 1> =>
6246 -- <adjust statements 1>
6247 -- ...
6248 -- when <discrete choices N> =>
6249 -- <adjust statements N>
6250 -- end case;
6252 Var_Case :=
6253 Make_Case_Statement (Loc,
6254 Expression =>
6255 Make_Selected_Component (Loc,
6256 Prefix => Make_Identifier (Loc, Name_V),
6257 Selector_Name =>
6258 Make_Identifier (Loc,
6259 Chars => Chars (Name (Variant_Part (Comps))))),
6260 Alternatives => Var_Alts);
6261 end;
6262 end if;
6264 -- Add the variant case statement to the list of statements
6266 if Present (Var_Case) then
6267 Append_To (Stmts, Var_Case);
6268 end if;
6270 -- If the component list did not have any controlled components
6271 -- nor variants, return null.
6273 if Is_Empty_List (Stmts) then
6274 Append_To (Stmts, Make_Null_Statement (Loc));
6275 end if;
6277 return Stmts;
6278 end Process_Component_List_For_Adjust;
6280 -- Start of processing for Build_Adjust_Statements
6282 begin
6283 Finalizer_Decls := New_List;
6284 Build_Object_Declarations (Finalizer_Data, Finalizer_Decls, Loc);
6286 if Nkind (Typ_Def) = N_Derived_Type_Definition then
6287 Rec_Def := Record_Extension_Part (Typ_Def);
6288 else
6289 Rec_Def := Typ_Def;
6290 end if;
6292 -- Create an adjust sequence for all record components
6294 if Present (Component_List (Rec_Def)) then
6295 Bod_Stmts :=
6296 Process_Component_List_For_Adjust (Component_List (Rec_Def));
6297 end if;
6299 -- A derived record type must adjust all inherited components. This
6300 -- action poses the following problem:
6302 -- procedure Deep_Adjust (Obj : in out Parent_Typ) is
6303 -- begin
6304 -- Adjust (Obj);
6305 -- ...
6307 -- procedure Deep_Adjust (Obj : in out Derived_Typ) is
6308 -- begin
6309 -- Deep_Adjust (Obj._parent);
6310 -- ...
6311 -- Adjust (Obj);
6312 -- ...
6314 -- Adjusting the derived type will invoke Adjust of the parent and
6315 -- then that of the derived type. This is undesirable because both
6316 -- routines may modify shared components. Only the Adjust of the
6317 -- derived type should be invoked.
6319 -- To prevent this double adjustment of shared components,
6320 -- Deep_Adjust uses a flag to control the invocation of Adjust:
6322 -- procedure Deep_Adjust
6323 -- (Obj : in out Some_Type;
6324 -- Flag : Boolean := True)
6325 -- is
6326 -- begin
6327 -- if Flag then
6328 -- Adjust (Obj);
6329 -- end if;
6330 -- ...
6332 -- When Deep_Adjust is invokes for field _parent, a value of False is
6333 -- provided for the flag:
6335 -- Deep_Adjust (Obj._parent, False);
6337 if Is_Tagged_Type (Typ) and then Is_Derived_Type (Typ) then
6338 declare
6339 Par_Typ : constant Entity_Id := Parent_Field_Type (Typ);
6340 Adj_Stmt : Node_Id;
6341 Call : Node_Id;
6343 begin
6344 if Needs_Finalization (Par_Typ) then
6345 Call :=
6346 Make_Adjust_Call
6347 (Obj_Ref =>
6348 Make_Selected_Component (Loc,
6349 Prefix => Make_Identifier (Loc, Name_V),
6350 Selector_Name =>
6351 Make_Identifier (Loc, Name_uParent)),
6352 Typ => Par_Typ,
6353 Skip_Self => True);
6355 -- Generate:
6356 -- Deep_Adjust (V._parent, False); -- No_Except_Propagat
6358 -- begin -- Exceptions OK
6359 -- Deep_Adjust (V._parent, False);
6360 -- exception
6361 -- when Id : others =>
6362 -- if not Raised then
6363 -- Raised := True;
6364 -- Save_Occurrence (E,
6365 -- Get_Current_Excep.all.all);
6366 -- end if;
6367 -- end;
6369 if Present (Call) then
6370 Adj_Stmt := Call;
6372 if Exceptions_OK then
6373 Adj_Stmt :=
6374 Make_Block_Statement (Loc,
6375 Handled_Statement_Sequence =>
6376 Make_Handled_Sequence_Of_Statements (Loc,
6377 Statements => New_List (Adj_Stmt),
6378 Exception_Handlers => New_List (
6379 Build_Exception_Handler (Finalizer_Data))));
6380 end if;
6382 Prepend_To (Bod_Stmts, Adj_Stmt);
6383 end if;
6384 end if;
6385 end;
6386 end if;
6388 -- Adjust the object. This action must be performed last after all
6389 -- components have been adjusted.
6391 if Is_Controlled (Typ) then
6392 declare
6393 Adj_Stmt : Node_Id;
6394 Proc : Entity_Id;
6396 begin
6397 Proc := Find_Prim_Op (Typ, Name_Adjust);
6399 -- Generate:
6400 -- if F then
6401 -- Adjust (V); -- No_Exception_Propagation
6403 -- begin -- Exception handlers allowed
6404 -- Adjust (V);
6405 -- exception
6406 -- when others =>
6407 -- if not Raised then
6408 -- Raised := True;
6409 -- Save_Occurrence (E,
6410 -- Get_Current_Excep.all.all);
6411 -- end if;
6412 -- end;
6413 -- end if;
6415 if Present (Proc) then
6416 Adj_Stmt :=
6417 Make_Procedure_Call_Statement (Loc,
6418 Name => New_Occurrence_Of (Proc, Loc),
6419 Parameter_Associations => New_List (
6420 Make_Identifier (Loc, Name_V)));
6422 if Exceptions_OK then
6423 Adj_Stmt :=
6424 Make_Block_Statement (Loc,
6425 Handled_Statement_Sequence =>
6426 Make_Handled_Sequence_Of_Statements (Loc,
6427 Statements => New_List (Adj_Stmt),
6428 Exception_Handlers => New_List (
6429 Build_Exception_Handler
6430 (Finalizer_Data))));
6431 end if;
6433 Append_To (Bod_Stmts,
6434 Make_If_Statement (Loc,
6435 Condition => Make_Identifier (Loc, Name_F),
6436 Then_Statements => New_List (Adj_Stmt)));
6437 end if;
6438 end;
6439 end if;
6441 -- At this point either all adjustment statements have been generated
6442 -- or the type is not controlled.
6444 if Is_Empty_List (Bod_Stmts) then
6445 Append_To (Bod_Stmts, Make_Null_Statement (Loc));
6447 return Bod_Stmts;
6449 -- Generate:
6450 -- declare
6451 -- Abort : constant Boolean := Triggered_By_Abort;
6452 -- <or>
6453 -- Abort : constant Boolean := False; -- no abort
6455 -- E : Exception_Occurence;
6456 -- Raised : Boolean := False;
6458 -- begin
6459 -- <adjust statements>
6461 -- if Raised and then not Abort then
6462 -- Raise_From_Controlled_Operation (E);
6463 -- end if;
6464 -- end;
6466 else
6467 if Exceptions_OK then
6468 Append_To (Bod_Stmts,
6469 Build_Raise_Statement (Finalizer_Data));
6470 end if;
6472 return
6473 New_List (
6474 Make_Block_Statement (Loc,
6475 Declarations =>
6476 Finalizer_Decls,
6477 Handled_Statement_Sequence =>
6478 Make_Handled_Sequence_Of_Statements (Loc, Bod_Stmts)));
6479 end if;
6480 end Build_Adjust_Statements;
6482 -------------------------------
6483 -- Build_Finalize_Statements --
6484 -------------------------------
6486 function Build_Finalize_Statements (Typ : Entity_Id) return List_Id is
6487 Loc : constant Source_Ptr := Sloc (Typ);
6488 Typ_Def : constant Node_Id := Type_Definition (Parent (Typ));
6489 Bod_Stmts : List_Id;
6490 Counter : Int := 0;
6491 Finalizer_Data : Finalization_Exception_Data;
6492 Finalizer_Decls : List_Id := No_List;
6493 Rec_Def : Node_Id;
6494 Var_Case : Node_Id;
6496 Exceptions_OK : constant Boolean :=
6497 not Restriction_Active (No_Exception_Propagation);
6499 function Process_Component_List_For_Finalize
6500 (Comps : Node_Id) return List_Id;
6501 -- Build all necessary finalization statements for a single component
6502 -- list. The statements may include a jump circuitry if flag Is_Local
6503 -- is enabled.
6505 -----------------------------------------
6506 -- Process_Component_List_For_Finalize --
6507 -----------------------------------------
6509 function Process_Component_List_For_Finalize
6510 (Comps : Node_Id) return List_Id
6512 Alts : List_Id;
6513 Counter_Id : Entity_Id;
6514 Decl : Node_Id;
6515 Decl_Id : Entity_Id;
6516 Decl_Typ : Entity_Id;
6517 Decls : List_Id;
6518 Has_POC : Boolean;
6519 Jump_Block : Node_Id;
6520 Label : Node_Id;
6521 Label_Id : Entity_Id;
6522 Num_Comps : Int;
6523 Stmts : List_Id;
6525 procedure Process_Component_For_Finalize
6526 (Decl : Node_Id;
6527 Alts : List_Id;
6528 Decls : List_Id;
6529 Stmts : List_Id);
6530 -- Process the declaration of a single controlled component. If
6531 -- flag Is_Local is enabled, create the corresponding label and
6532 -- jump circuitry. Alts is the list of case alternatives, Decls
6533 -- is the top level declaration list where labels are declared
6534 -- and Stmts is the list of finalization actions.
6536 ------------------------------------
6537 -- Process_Component_For_Finalize --
6538 ------------------------------------
6540 procedure Process_Component_For_Finalize
6541 (Decl : Node_Id;
6542 Alts : List_Id;
6543 Decls : List_Id;
6544 Stmts : List_Id)
6546 Id : constant Entity_Id := Defining_Identifier (Decl);
6547 Typ : constant Entity_Id := Etype (Id);
6548 Fin_Stmt : Node_Id;
6550 begin
6551 if Is_Local then
6552 declare
6553 Label : Node_Id;
6554 Label_Id : Entity_Id;
6556 begin
6557 -- Generate:
6558 -- LN : label;
6560 Label_Id :=
6561 Make_Identifier (Loc,
6562 Chars => New_External_Name ('L', Num_Comps));
6563 Set_Entity (Label_Id,
6564 Make_Defining_Identifier (Loc, Chars (Label_Id)));
6565 Label := Make_Label (Loc, Label_Id);
6567 Append_To (Decls,
6568 Make_Implicit_Label_Declaration (Loc,
6569 Defining_Identifier => Entity (Label_Id),
6570 Label_Construct => Label));
6572 -- Generate:
6573 -- when N =>
6574 -- goto LN;
6576 Append_To (Alts,
6577 Make_Case_Statement_Alternative (Loc,
6578 Discrete_Choices => New_List (
6579 Make_Integer_Literal (Loc, Num_Comps)),
6581 Statements => New_List (
6582 Make_Goto_Statement (Loc,
6583 Name =>
6584 New_Occurrence_Of (Entity (Label_Id), Loc)))));
6586 -- Generate:
6587 -- <<LN>>
6589 Append_To (Stmts, Label);
6591 -- Decrease the number of components to be processed.
6592 -- This action yields a new Label_Id in future calls.
6594 Num_Comps := Num_Comps - 1;
6595 end;
6596 end if;
6598 -- Generate:
6599 -- [Deep_]Finalize (V.Id); -- No_Exception_Propagation
6601 -- begin -- Exception handlers allowed
6602 -- [Deep_]Finalize (V.Id);
6603 -- exception
6604 -- when others =>
6605 -- if not Raised then
6606 -- Raised := True;
6607 -- Save_Occurrence (E,
6608 -- Get_Current_Excep.all.all);
6609 -- end if;
6610 -- end;
6612 Fin_Stmt :=
6613 Make_Final_Call
6614 (Obj_Ref =>
6615 Make_Selected_Component (Loc,
6616 Prefix => Make_Identifier (Loc, Name_V),
6617 Selector_Name => Make_Identifier (Loc, Chars (Id))),
6618 Typ => Typ);
6620 if not Restriction_Active (No_Exception_Propagation) then
6621 Fin_Stmt :=
6622 Make_Block_Statement (Loc,
6623 Handled_Statement_Sequence =>
6624 Make_Handled_Sequence_Of_Statements (Loc,
6625 Statements => New_List (Fin_Stmt),
6626 Exception_Handlers => New_List (
6627 Build_Exception_Handler (Finalizer_Data))));
6628 end if;
6630 Append_To (Stmts, Fin_Stmt);
6631 end Process_Component_For_Finalize;
6633 -- Start of processing for Process_Component_List_For_Finalize
6635 begin
6636 -- Perform an initial check, look for controlled and per-object
6637 -- constrained components.
6639 Preprocess_Components (Comps, Num_Comps, Has_POC);
6641 -- Create a state counter to service the current component list.
6642 -- This step is performed before the variants are inspected in
6643 -- order to generate the same state counter names as those from
6644 -- Build_Initialize_Statements.
6646 if Num_Comps > 0 and then Is_Local then
6647 Counter := Counter + 1;
6649 Counter_Id :=
6650 Make_Defining_Identifier (Loc,
6651 Chars => New_External_Name ('C', Counter));
6652 end if;
6654 -- Process the component in the following order:
6655 -- 1) Variants
6656 -- 2) Per-object constrained components
6657 -- 3) Regular components
6659 -- Start with the variant parts
6661 Var_Case := Empty;
6662 if Present (Variant_Part (Comps)) then
6663 declare
6664 Var_Alts : constant List_Id := New_List;
6665 Var : Node_Id;
6667 begin
6668 Var := First_Non_Pragma (Variants (Variant_Part (Comps)));
6669 while Present (Var) loop
6671 -- Generate:
6672 -- when <discrete choices> =>
6673 -- <finalize statements>
6675 Append_To (Var_Alts,
6676 Make_Case_Statement_Alternative (Loc,
6677 Discrete_Choices =>
6678 New_Copy_List (Discrete_Choices (Var)),
6679 Statements =>
6680 Process_Component_List_For_Finalize (
6681 Component_List (Var))));
6683 Next_Non_Pragma (Var);
6684 end loop;
6686 -- Generate:
6687 -- case V.<discriminant> is
6688 -- when <discrete choices 1> =>
6689 -- <finalize statements 1>
6690 -- ...
6691 -- when <discrete choices N> =>
6692 -- <finalize statements N>
6693 -- end case;
6695 Var_Case :=
6696 Make_Case_Statement (Loc,
6697 Expression =>
6698 Make_Selected_Component (Loc,
6699 Prefix => Make_Identifier (Loc, Name_V),
6700 Selector_Name =>
6701 Make_Identifier (Loc,
6702 Chars => Chars (Name (Variant_Part (Comps))))),
6703 Alternatives => Var_Alts);
6704 end;
6705 end if;
6707 -- The current component list does not have a single controlled
6708 -- component, however it may contain variants. Return the case
6709 -- statement for the variants or nothing.
6711 if Num_Comps = 0 then
6712 if Present (Var_Case) then
6713 return New_List (Var_Case);
6714 else
6715 return New_List (Make_Null_Statement (Loc));
6716 end if;
6717 end if;
6719 -- Prepare all lists
6721 Alts := New_List;
6722 Decls := New_List;
6723 Stmts := New_List;
6725 -- Process all per-object constrained components in reverse order
6727 if Has_POC then
6728 Decl := Last_Non_Pragma (Component_Items (Comps));
6729 while Present (Decl) loop
6730 Decl_Id := Defining_Identifier (Decl);
6731 Decl_Typ := Etype (Decl_Id);
6733 -- Skip _parent
6735 if Chars (Decl_Id) /= Name_uParent
6736 and then Needs_Finalization (Decl_Typ)
6737 and then Has_Access_Constraint (Decl_Id)
6738 and then No (Expression (Decl))
6739 then
6740 Process_Component_For_Finalize (Decl, Alts, Decls, Stmts);
6741 end if;
6743 Prev_Non_Pragma (Decl);
6744 end loop;
6745 end if;
6747 -- Process the rest of the components in reverse order
6749 Decl := Last_Non_Pragma (Component_Items (Comps));
6750 while Present (Decl) loop
6751 Decl_Id := Defining_Identifier (Decl);
6752 Decl_Typ := Etype (Decl_Id);
6754 -- Skip _parent
6756 if Chars (Decl_Id) /= Name_uParent
6757 and then Needs_Finalization (Decl_Typ)
6758 then
6759 -- Skip per-object constrained components since they were
6760 -- handled in the above step.
6762 if Has_Access_Constraint (Decl_Id)
6763 and then No (Expression (Decl))
6764 then
6765 null;
6766 else
6767 Process_Component_For_Finalize (Decl, Alts, Decls, Stmts);
6768 end if;
6769 end if;
6771 Prev_Non_Pragma (Decl);
6772 end loop;
6774 -- Generate:
6775 -- declare
6776 -- LN : label; -- If Is_Local is enabled
6777 -- ... .
6778 -- L0 : label; .
6780 -- begin .
6781 -- case CounterX is .
6782 -- when N => .
6783 -- goto LN; .
6784 -- ... .
6785 -- when 1 => .
6786 -- goto L1; .
6787 -- when others => .
6788 -- goto L0; .
6789 -- end case; .
6791 -- <<LN>> -- If Is_Local is enabled
6792 -- begin
6793 -- [Deep_]Finalize (V.CompY);
6794 -- exception
6795 -- when Id : others =>
6796 -- if not Raised then
6797 -- Raised := True;
6798 -- Save_Occurrence (E,
6799 -- Get_Current_Excep.all.all);
6800 -- end if;
6801 -- end;
6802 -- ...
6803 -- <<L0>> -- If Is_Local is enabled
6804 -- end;
6806 if Is_Local then
6808 -- Add the declaration of default jump location L0, its
6809 -- corresponding alternative and its place in the statements.
6811 Label_Id := Make_Identifier (Loc, New_External_Name ('L', 0));
6812 Set_Entity (Label_Id,
6813 Make_Defining_Identifier (Loc, Chars (Label_Id)));
6814 Label := Make_Label (Loc, Label_Id);
6816 Append_To (Decls, -- declaration
6817 Make_Implicit_Label_Declaration (Loc,
6818 Defining_Identifier => Entity (Label_Id),
6819 Label_Construct => Label));
6821 Append_To (Alts, -- alternative
6822 Make_Case_Statement_Alternative (Loc,
6823 Discrete_Choices => New_List (
6824 Make_Others_Choice (Loc)),
6826 Statements => New_List (
6827 Make_Goto_Statement (Loc,
6828 Name => New_Occurrence_Of (Entity (Label_Id), Loc)))));
6830 Append_To (Stmts, Label); -- statement
6832 -- Create the jump block
6834 Prepend_To (Stmts,
6835 Make_Case_Statement (Loc,
6836 Expression => Make_Identifier (Loc, Chars (Counter_Id)),
6837 Alternatives => Alts));
6838 end if;
6840 Jump_Block :=
6841 Make_Block_Statement (Loc,
6842 Declarations => Decls,
6843 Handled_Statement_Sequence =>
6844 Make_Handled_Sequence_Of_Statements (Loc, Stmts));
6846 if Present (Var_Case) then
6847 return New_List (Var_Case, Jump_Block);
6848 else
6849 return New_List (Jump_Block);
6850 end if;
6851 end Process_Component_List_For_Finalize;
6853 -- Start of processing for Build_Finalize_Statements
6855 begin
6856 Finalizer_Decls := New_List;
6857 Build_Object_Declarations (Finalizer_Data, Finalizer_Decls, Loc);
6859 if Nkind (Typ_Def) = N_Derived_Type_Definition then
6860 Rec_Def := Record_Extension_Part (Typ_Def);
6861 else
6862 Rec_Def := Typ_Def;
6863 end if;
6865 -- Create a finalization sequence for all record components
6867 if Present (Component_List (Rec_Def)) then
6868 Bod_Stmts :=
6869 Process_Component_List_For_Finalize (Component_List (Rec_Def));
6870 end if;
6872 -- A derived record type must finalize all inherited components. This
6873 -- action poses the following problem:
6875 -- procedure Deep_Finalize (Obj : in out Parent_Typ) is
6876 -- begin
6877 -- Finalize (Obj);
6878 -- ...
6880 -- procedure Deep_Finalize (Obj : in out Derived_Typ) is
6881 -- begin
6882 -- Deep_Finalize (Obj._parent);
6883 -- ...
6884 -- Finalize (Obj);
6885 -- ...
6887 -- Finalizing the derived type will invoke Finalize of the parent and
6888 -- then that of the derived type. This is undesirable because both
6889 -- routines may modify shared components. Only the Finalize of the
6890 -- derived type should be invoked.
6892 -- To prevent this double adjustment of shared components,
6893 -- Deep_Finalize uses a flag to control the invocation of Finalize:
6895 -- procedure Deep_Finalize
6896 -- (Obj : in out Some_Type;
6897 -- Flag : Boolean := True)
6898 -- is
6899 -- begin
6900 -- if Flag then
6901 -- Finalize (Obj);
6902 -- end if;
6903 -- ...
6905 -- When Deep_Finalize is invokes for field _parent, a value of False
6906 -- is provided for the flag:
6908 -- Deep_Finalize (Obj._parent, False);
6910 if Is_Tagged_Type (Typ) and then Is_Derived_Type (Typ) then
6911 declare
6912 Par_Typ : constant Entity_Id := Parent_Field_Type (Typ);
6913 Call : Node_Id;
6914 Fin_Stmt : Node_Id;
6916 begin
6917 if Needs_Finalization (Par_Typ) then
6918 Call :=
6919 Make_Final_Call
6920 (Obj_Ref =>
6921 Make_Selected_Component (Loc,
6922 Prefix => Make_Identifier (Loc, Name_V),
6923 Selector_Name =>
6924 Make_Identifier (Loc, Name_uParent)),
6925 Typ => Par_Typ,
6926 Skip_Self => True);
6928 -- Generate:
6929 -- Deep_Finalize (V._parent, False); -- No_Except_Propag
6931 -- begin -- Exceptions OK
6932 -- Deep_Finalize (V._parent, False);
6933 -- exception
6934 -- when Id : others =>
6935 -- if not Raised then
6936 -- Raised := True;
6937 -- Save_Occurrence (E,
6938 -- Get_Current_Excep.all.all);
6939 -- end if;
6940 -- end;
6942 if Present (Call) then
6943 Fin_Stmt := Call;
6945 if Exceptions_OK then
6946 Fin_Stmt :=
6947 Make_Block_Statement (Loc,
6948 Handled_Statement_Sequence =>
6949 Make_Handled_Sequence_Of_Statements (Loc,
6950 Statements => New_List (Fin_Stmt),
6951 Exception_Handlers => New_List (
6952 Build_Exception_Handler
6953 (Finalizer_Data))));
6954 end if;
6956 Append_To (Bod_Stmts, Fin_Stmt);
6957 end if;
6958 end if;
6959 end;
6960 end if;
6962 -- Finalize the object. This action must be performed first before
6963 -- all components have been finalized.
6965 if Is_Controlled (Typ) and then not Is_Local then
6966 declare
6967 Fin_Stmt : Node_Id;
6968 Proc : Entity_Id;
6970 begin
6971 Proc := Find_Prim_Op (Typ, Name_Finalize);
6973 -- Generate:
6974 -- if F then
6975 -- Finalize (V); -- No_Exception_Propagation
6977 -- begin
6978 -- Finalize (V);
6979 -- exception
6980 -- when others =>
6981 -- if not Raised then
6982 -- Raised := True;
6983 -- Save_Occurrence (E,
6984 -- Get_Current_Excep.all.all);
6985 -- end if;
6986 -- end;
6987 -- end if;
6989 if Present (Proc) then
6990 Fin_Stmt :=
6991 Make_Procedure_Call_Statement (Loc,
6992 Name => New_Occurrence_Of (Proc, Loc),
6993 Parameter_Associations => New_List (
6994 Make_Identifier (Loc, Name_V)));
6996 if Exceptions_OK then
6997 Fin_Stmt :=
6998 Make_Block_Statement (Loc,
6999 Handled_Statement_Sequence =>
7000 Make_Handled_Sequence_Of_Statements (Loc,
7001 Statements => New_List (Fin_Stmt),
7002 Exception_Handlers => New_List (
7003 Build_Exception_Handler
7004 (Finalizer_Data))));
7005 end if;
7007 Prepend_To (Bod_Stmts,
7008 Make_If_Statement (Loc,
7009 Condition => Make_Identifier (Loc, Name_F),
7010 Then_Statements => New_List (Fin_Stmt)));
7011 end if;
7012 end;
7013 end if;
7015 -- At this point either all finalization statements have been
7016 -- generated or the type is not controlled.
7018 if No (Bod_Stmts) then
7019 return New_List (Make_Null_Statement (Loc));
7021 -- Generate:
7022 -- declare
7023 -- Abort : constant Boolean := Triggered_By_Abort;
7024 -- <or>
7025 -- Abort : constant Boolean := False; -- no abort
7027 -- E : Exception_Occurence;
7028 -- Raised : Boolean := False;
7030 -- begin
7031 -- <finalize statements>
7033 -- if Raised and then not Abort then
7034 -- Raise_From_Controlled_Operation (E);
7035 -- end if;
7036 -- end;
7038 else
7039 if Exceptions_OK then
7040 Append_To (Bod_Stmts,
7041 Build_Raise_Statement (Finalizer_Data));
7042 end if;
7044 return
7045 New_List (
7046 Make_Block_Statement (Loc,
7047 Declarations =>
7048 Finalizer_Decls,
7049 Handled_Statement_Sequence =>
7050 Make_Handled_Sequence_Of_Statements (Loc, Bod_Stmts)));
7051 end if;
7052 end Build_Finalize_Statements;
7054 -----------------------
7055 -- Parent_Field_Type --
7056 -----------------------
7058 function Parent_Field_Type (Typ : Entity_Id) return Entity_Id is
7059 Field : Entity_Id;
7061 begin
7062 Field := First_Entity (Typ);
7063 while Present (Field) loop
7064 if Chars (Field) = Name_uParent then
7065 return Etype (Field);
7066 end if;
7068 Next_Entity (Field);
7069 end loop;
7071 -- A derived tagged type should always have a parent field
7073 raise Program_Error;
7074 end Parent_Field_Type;
7076 ---------------------------
7077 -- Preprocess_Components --
7078 ---------------------------
7080 procedure Preprocess_Components
7081 (Comps : Node_Id;
7082 Num_Comps : out Int;
7083 Has_POC : out Boolean)
7085 Decl : Node_Id;
7086 Id : Entity_Id;
7087 Typ : Entity_Id;
7089 begin
7090 Num_Comps := 0;
7091 Has_POC := False;
7093 Decl := First_Non_Pragma (Component_Items (Comps));
7094 while Present (Decl) loop
7095 Id := Defining_Identifier (Decl);
7096 Typ := Etype (Id);
7098 -- Skip field _parent
7100 if Chars (Id) /= Name_uParent
7101 and then Needs_Finalization (Typ)
7102 then
7103 Num_Comps := Num_Comps + 1;
7105 if Has_Access_Constraint (Id)
7106 and then No (Expression (Decl))
7107 then
7108 Has_POC := True;
7109 end if;
7110 end if;
7112 Next_Non_Pragma (Decl);
7113 end loop;
7114 end Preprocess_Components;
7116 -- Start of processing for Make_Deep_Record_Body
7118 begin
7119 case Prim is
7120 when Address_Case =>
7121 return Make_Finalize_Address_Stmts (Typ);
7123 when Adjust_Case =>
7124 return Build_Adjust_Statements (Typ);
7126 when Finalize_Case =>
7127 return Build_Finalize_Statements (Typ);
7129 when Initialize_Case =>
7130 declare
7131 Loc : constant Source_Ptr := Sloc (Typ);
7133 begin
7134 if Is_Controlled (Typ) then
7135 return New_List (
7136 Make_Procedure_Call_Statement (Loc,
7137 Name =>
7138 New_Occurrence_Of
7139 (Find_Prim_Op (Typ, Name_Of (Prim)), Loc),
7140 Parameter_Associations => New_List (
7141 Make_Identifier (Loc, Name_V))));
7142 else
7143 return Empty_List;
7144 end if;
7145 end;
7146 end case;
7147 end Make_Deep_Record_Body;
7149 ----------------------
7150 -- Make_Final_Call --
7151 ----------------------
7153 function Make_Final_Call
7154 (Obj_Ref : Node_Id;
7155 Typ : Entity_Id;
7156 Skip_Self : Boolean := False) return Node_Id
7158 Loc : constant Source_Ptr := Sloc (Obj_Ref);
7159 Atyp : Entity_Id;
7160 Fin_Id : Entity_Id := Empty;
7161 Ref : Node_Id;
7162 Utyp : Entity_Id;
7164 begin
7165 -- Recover the proper type which contains [Deep_]Finalize
7167 if Is_Class_Wide_Type (Typ) then
7168 Utyp := Root_Type (Typ);
7169 Atyp := Utyp;
7170 Ref := Obj_Ref;
7172 elsif Is_Concurrent_Type (Typ) then
7173 Utyp := Corresponding_Record_Type (Typ);
7174 Atyp := Empty;
7175 Ref := Convert_Concurrent (Obj_Ref, Typ);
7177 elsif Is_Private_Type (Typ)
7178 and then Present (Full_View (Typ))
7179 and then Is_Concurrent_Type (Full_View (Typ))
7180 then
7181 Utyp := Corresponding_Record_Type (Full_View (Typ));
7182 Atyp := Typ;
7183 Ref := Convert_Concurrent (Obj_Ref, Full_View (Typ));
7185 else
7186 Utyp := Typ;
7187 Atyp := Typ;
7188 Ref := Obj_Ref;
7189 end if;
7191 Utyp := Underlying_Type (Base_Type (Utyp));
7192 Set_Assignment_OK (Ref);
7194 -- Deal with untagged derivation of private views. If the parent type
7195 -- is a protected type, Deep_Finalize is found on the corresponding
7196 -- record of the ancestor.
7198 if Is_Untagged_Derivation (Typ) then
7199 if Is_Protected_Type (Typ) then
7200 Utyp := Corresponding_Record_Type (Root_Type (Base_Type (Typ)));
7201 else
7202 Utyp := Underlying_Type (Root_Type (Base_Type (Typ)));
7204 if Is_Protected_Type (Utyp) then
7205 Utyp := Corresponding_Record_Type (Utyp);
7206 end if;
7207 end if;
7209 Ref := Unchecked_Convert_To (Utyp, Ref);
7210 Set_Assignment_OK (Ref);
7211 end if;
7213 -- Deal with derived private types which do not inherit primitives from
7214 -- their parents. In this case, [Deep_]Finalize can be found in the full
7215 -- view of the parent type.
7217 if Is_Tagged_Type (Utyp)
7218 and then Is_Derived_Type (Utyp)
7219 and then Is_Empty_Elmt_List (Primitive_Operations (Utyp))
7220 and then Is_Private_Type (Etype (Utyp))
7221 and then Present (Full_View (Etype (Utyp)))
7222 then
7223 Utyp := Full_View (Etype (Utyp));
7224 Ref := Unchecked_Convert_To (Utyp, Ref);
7225 Set_Assignment_OK (Ref);
7226 end if;
7228 -- When dealing with the completion of a private type, use the base type
7229 -- instead.
7231 if Utyp /= Base_Type (Utyp) then
7232 pragma Assert (Present (Atyp) and then Is_Private_Type (Atyp));
7234 Utyp := Base_Type (Utyp);
7235 Ref := Unchecked_Convert_To (Utyp, Ref);
7236 Set_Assignment_OK (Ref);
7237 end if;
7239 if Skip_Self then
7240 if Has_Controlled_Component (Utyp) then
7241 if Is_Tagged_Type (Utyp) then
7242 Fin_Id := Find_Prim_Op (Utyp, TSS_Deep_Finalize);
7243 else
7244 Fin_Id := TSS (Utyp, TSS_Deep_Finalize);
7245 end if;
7246 end if;
7248 -- Class-wide types, interfaces and types with controlled components
7250 elsif Is_Class_Wide_Type (Typ)
7251 or else Is_Interface (Typ)
7252 or else Has_Controlled_Component (Utyp)
7253 then
7254 if Is_Tagged_Type (Utyp) then
7255 Fin_Id := Find_Prim_Op (Utyp, TSS_Deep_Finalize);
7256 else
7257 Fin_Id := TSS (Utyp, TSS_Deep_Finalize);
7258 end if;
7260 -- Derivations from [Limited_]Controlled
7262 elsif Is_Controlled (Utyp) then
7263 if Has_Controlled_Component (Utyp) then
7264 Fin_Id := Find_Prim_Op (Utyp, TSS_Deep_Finalize);
7265 else
7266 Fin_Id := Find_Prim_Op (Utyp, Name_Of (Finalize_Case));
7267 end if;
7269 -- Tagged types
7271 elsif Is_Tagged_Type (Utyp) then
7272 Fin_Id := Find_Prim_Op (Utyp, TSS_Deep_Finalize);
7274 else
7275 raise Program_Error;
7276 end if;
7278 if Present (Fin_Id) then
7280 -- When finalizing a class-wide object, do not convert to the root
7281 -- type in order to produce a dispatching call.
7283 if Is_Class_Wide_Type (Typ) then
7284 null;
7286 -- Ensure that a finalization routine is at least decorated in order
7287 -- to inspect the object parameter.
7289 elsif Analyzed (Fin_Id)
7290 or else Ekind (Fin_Id) = E_Procedure
7291 then
7292 -- In certain cases, such as the creation of Stream_Read, the
7293 -- visible entity of the type is its full view. Since Stream_Read
7294 -- will have to create an object of type Typ, the local object
7295 -- will be finalzed by the scope finalizer generated later on. The
7296 -- object parameter of Deep_Finalize will always use the private
7297 -- view of the type. To avoid such a clash between a private and a
7298 -- full view, perform an unchecked conversion of the object
7299 -- reference to the private view.
7301 declare
7302 Formal_Typ : constant Entity_Id :=
7303 Etype (First_Formal (Fin_Id));
7304 begin
7305 if Is_Private_Type (Formal_Typ)
7306 and then Present (Full_View (Formal_Typ))
7307 and then Full_View (Formal_Typ) = Utyp
7308 then
7309 Ref := Unchecked_Convert_To (Formal_Typ, Ref);
7310 end if;
7311 end;
7313 Ref := Convert_View (Fin_Id, Ref);
7314 end if;
7316 return
7317 Make_Call (Loc,
7318 Proc_Id => Fin_Id,
7319 Param => New_Copy_Tree (Ref),
7320 Skip_Self => Skip_Self);
7321 else
7322 return Empty;
7323 end if;
7324 end Make_Final_Call;
7326 --------------------------------
7327 -- Make_Finalize_Address_Body --
7328 --------------------------------
7330 procedure Make_Finalize_Address_Body (Typ : Entity_Id) is
7331 Is_Task : constant Boolean :=
7332 Ekind (Typ) = E_Record_Type
7333 and then Is_Concurrent_Record_Type (Typ)
7334 and then Ekind (Corresponding_Concurrent_Type (Typ)) =
7335 E_Task_Type;
7336 Loc : constant Source_Ptr := Sloc (Typ);
7337 Proc_Id : Entity_Id;
7338 Stmts : List_Id;
7340 begin
7341 -- The corresponding records of task types are not controlled by design.
7342 -- For the sake of completeness, create an empty Finalize_Address to be
7343 -- used in task class-wide allocations.
7345 if Is_Task then
7346 null;
7348 -- Nothing to do if the type is not controlled or it already has a
7349 -- TSS entry for Finalize_Address. Skip class-wide subtypes which do not
7350 -- come from source. These are usually generated for completeness and
7351 -- do not need the Finalize_Address primitive.
7353 elsif not Needs_Finalization (Typ)
7354 or else Is_Abstract_Type (Typ)
7355 or else Present (TSS (Typ, TSS_Finalize_Address))
7356 or else
7357 (Is_Class_Wide_Type (Typ)
7358 and then Ekind (Root_Type (Typ)) = E_Record_Subtype
7359 and then not Comes_From_Source (Root_Type (Typ)))
7360 then
7361 return;
7362 end if;
7364 Proc_Id :=
7365 Make_Defining_Identifier (Loc,
7366 Make_TSS_Name (Typ, TSS_Finalize_Address));
7368 -- Generate:
7370 -- procedure <Typ>FD (V : System.Address) is
7371 -- begin
7372 -- null; -- for tasks
7374 -- declare -- for all other types
7375 -- type Pnn is access all Typ;
7376 -- for Pnn'Storage_Size use 0;
7377 -- begin
7378 -- [Deep_]Finalize (Pnn (V).all);
7379 -- end;
7380 -- end TypFD;
7382 if Is_Task then
7383 Stmts := New_List (Make_Null_Statement (Loc));
7384 else
7385 Stmts := Make_Finalize_Address_Stmts (Typ);
7386 end if;
7388 Discard_Node (
7389 Make_Subprogram_Body (Loc,
7390 Specification =>
7391 Make_Procedure_Specification (Loc,
7392 Defining_Unit_Name => Proc_Id,
7394 Parameter_Specifications => New_List (
7395 Make_Parameter_Specification (Loc,
7396 Defining_Identifier =>
7397 Make_Defining_Identifier (Loc, Name_V),
7398 Parameter_Type =>
7399 New_Occurrence_Of (RTE (RE_Address), Loc)))),
7401 Declarations => No_List,
7403 Handled_Statement_Sequence =>
7404 Make_Handled_Sequence_Of_Statements (Loc,
7405 Statements => Stmts)));
7407 Set_TSS (Typ, Proc_Id);
7408 end Make_Finalize_Address_Body;
7410 ---------------------------------
7411 -- Make_Finalize_Address_Stmts --
7412 ---------------------------------
7414 function Make_Finalize_Address_Stmts (Typ : Entity_Id) return List_Id is
7415 Loc : constant Source_Ptr := Sloc (Typ);
7416 Ptr_Typ : constant Entity_Id := Make_Temporary (Loc, 'P');
7417 Decls : List_Id;
7418 Desg_Typ : Entity_Id;
7419 Obj_Expr : Node_Id;
7421 begin
7422 if Is_Array_Type (Typ) then
7423 if Is_Constrained (First_Subtype (Typ)) then
7424 Desg_Typ := First_Subtype (Typ);
7425 else
7426 Desg_Typ := Base_Type (Typ);
7427 end if;
7429 -- Class-wide types of constrained root types
7431 elsif Is_Class_Wide_Type (Typ)
7432 and then Has_Discriminants (Root_Type (Typ))
7433 and then not
7434 Is_Empty_Elmt_List (Discriminant_Constraint (Root_Type (Typ)))
7435 then
7436 declare
7437 Parent_Typ : Entity_Id;
7439 begin
7440 -- Climb the parent type chain looking for a non-constrained type
7442 Parent_Typ := Root_Type (Typ);
7443 while Parent_Typ /= Etype (Parent_Typ)
7444 and then Has_Discriminants (Parent_Typ)
7445 and then not
7446 Is_Empty_Elmt_List (Discriminant_Constraint (Parent_Typ))
7447 loop
7448 Parent_Typ := Etype (Parent_Typ);
7449 end loop;
7451 -- Handle views created for tagged types with unknown
7452 -- discriminants.
7454 if Is_Underlying_Record_View (Parent_Typ) then
7455 Parent_Typ := Underlying_Record_View (Parent_Typ);
7456 end if;
7458 Desg_Typ := Class_Wide_Type (Underlying_Type (Parent_Typ));
7459 end;
7461 -- General case
7463 else
7464 Desg_Typ := Typ;
7465 end if;
7467 -- Generate:
7468 -- type Ptr_Typ is access all Typ;
7469 -- for Ptr_Typ'Storage_Size use 0;
7471 Decls := New_List (
7472 Make_Full_Type_Declaration (Loc,
7473 Defining_Identifier => Ptr_Typ,
7474 Type_Definition =>
7475 Make_Access_To_Object_Definition (Loc,
7476 All_Present => True,
7477 Subtype_Indication => New_Occurrence_Of (Desg_Typ, Loc))),
7479 Make_Attribute_Definition_Clause (Loc,
7480 Name => New_Occurrence_Of (Ptr_Typ, Loc),
7481 Chars => Name_Storage_Size,
7482 Expression => Make_Integer_Literal (Loc, 0)));
7484 Obj_Expr := Make_Identifier (Loc, Name_V);
7486 -- Unconstrained arrays require special processing in order to retrieve
7487 -- the elements. To achieve this, we have to skip the dope vector which
7488 -- lays in front of the elements and then use a thin pointer to perform
7489 -- the address-to-access conversion.
7491 if Is_Array_Type (Typ)
7492 and then not Is_Constrained (First_Subtype (Typ))
7493 then
7494 declare
7495 Dope_Id : Entity_Id;
7497 begin
7498 -- Ensure that Ptr_Typ a thin pointer, generate:
7499 -- for Ptr_Typ'Size use System.Address'Size;
7501 Append_To (Decls,
7502 Make_Attribute_Definition_Clause (Loc,
7503 Name => New_Occurrence_Of (Ptr_Typ, Loc),
7504 Chars => Name_Size,
7505 Expression =>
7506 Make_Integer_Literal (Loc, System_Address_Size)));
7508 -- Generate:
7509 -- Dnn : constant Storage_Offset :=
7510 -- Desg_Typ'Descriptor_Size / Storage_Unit;
7512 Dope_Id := Make_Temporary (Loc, 'D');
7514 Append_To (Decls,
7515 Make_Object_Declaration (Loc,
7516 Defining_Identifier => Dope_Id,
7517 Constant_Present => True,
7518 Object_Definition =>
7519 New_Occurrence_Of (RTE (RE_Storage_Offset), Loc),
7520 Expression =>
7521 Make_Op_Divide (Loc,
7522 Left_Opnd =>
7523 Make_Attribute_Reference (Loc,
7524 Prefix => New_Occurrence_Of (Desg_Typ, Loc),
7525 Attribute_Name => Name_Descriptor_Size),
7526 Right_Opnd =>
7527 Make_Integer_Literal (Loc, System_Storage_Unit))));
7529 -- Shift the address from the start of the dope vector to the
7530 -- start of the elements:
7532 -- V + Dnn
7534 -- Note that this is done through a wrapper routine since RTSfind
7535 -- cannot retrieve operations with string names of the form "+".
7537 Obj_Expr :=
7538 Make_Function_Call (Loc,
7539 Name =>
7540 New_Occurrence_Of (RTE (RE_Add_Offset_To_Address), Loc),
7541 Parameter_Associations => New_List (
7542 Obj_Expr,
7543 New_Occurrence_Of (Dope_Id, Loc)));
7544 end;
7545 end if;
7547 -- Create the block and the finalization call
7549 return New_List (
7550 Make_Block_Statement (Loc,
7551 Declarations => Decls,
7553 Handled_Statement_Sequence =>
7554 Make_Handled_Sequence_Of_Statements (Loc,
7555 Statements => New_List (
7556 Make_Final_Call (
7557 Obj_Ref =>
7558 Make_Explicit_Dereference (Loc,
7559 Prefix => Unchecked_Convert_To (Ptr_Typ, Obj_Expr)),
7560 Typ => Desg_Typ)))));
7561 end Make_Finalize_Address_Stmts;
7563 -------------------------------------
7564 -- Make_Handler_For_Ctrl_Operation --
7565 -------------------------------------
7567 -- Generate:
7569 -- when E : others =>
7570 -- Raise_From_Controlled_Operation (E);
7572 -- or:
7574 -- when others =>
7575 -- raise Program_Error [finalize raised exception];
7577 -- depending on whether Raise_From_Controlled_Operation is available
7579 function Make_Handler_For_Ctrl_Operation
7580 (Loc : Source_Ptr) return Node_Id
7582 E_Occ : Entity_Id;
7583 -- Choice parameter (for the first case above)
7585 Raise_Node : Node_Id;
7586 -- Procedure call or raise statement
7588 begin
7589 -- Standard run-time, .NET/JVM targets: add choice parameter E and pass
7590 -- it to Raise_From_Controlled_Operation so that the original exception
7591 -- name and message can be recorded in the exception message for
7592 -- Program_Error.
7594 if RTE_Available (RE_Raise_From_Controlled_Operation) then
7595 E_Occ := Make_Defining_Identifier (Loc, Name_E);
7596 Raise_Node :=
7597 Make_Procedure_Call_Statement (Loc,
7598 Name =>
7599 New_Occurrence_Of
7600 (RTE (RE_Raise_From_Controlled_Operation), Loc),
7601 Parameter_Associations => New_List (
7602 New_Occurrence_Of (E_Occ, Loc)));
7604 -- Restricted run-time: exception messages are not supported
7606 else
7607 E_Occ := Empty;
7608 Raise_Node :=
7609 Make_Raise_Program_Error (Loc,
7610 Reason => PE_Finalize_Raised_Exception);
7611 end if;
7613 return
7614 Make_Implicit_Exception_Handler (Loc,
7615 Exception_Choices => New_List (Make_Others_Choice (Loc)),
7616 Choice_Parameter => E_Occ,
7617 Statements => New_List (Raise_Node));
7618 end Make_Handler_For_Ctrl_Operation;
7620 --------------------
7621 -- Make_Init_Call --
7622 --------------------
7624 function Make_Init_Call
7625 (Obj_Ref : Node_Id;
7626 Typ : Entity_Id) return Node_Id
7628 Loc : constant Source_Ptr := Sloc (Obj_Ref);
7629 Is_Conc : Boolean;
7630 Proc : Entity_Id;
7631 Ref : Node_Id;
7632 Utyp : Entity_Id;
7634 begin
7635 -- Deal with the type and object reference. Depending on the context, an
7636 -- object reference may need several conversions.
7638 if Is_Concurrent_Type (Typ) then
7639 Is_Conc := True;
7640 Utyp := Corresponding_Record_Type (Typ);
7641 Ref := Convert_Concurrent (Obj_Ref, Typ);
7643 elsif Is_Private_Type (Typ)
7644 and then Present (Full_View (Typ))
7645 and then Is_Concurrent_Type (Underlying_Type (Typ))
7646 then
7647 Is_Conc := True;
7648 Utyp := Corresponding_Record_Type (Underlying_Type (Typ));
7649 Ref := Convert_Concurrent (Obj_Ref, Underlying_Type (Typ));
7651 else
7652 Is_Conc := False;
7653 Utyp := Typ;
7654 Ref := Obj_Ref;
7655 end if;
7657 Set_Assignment_OK (Ref);
7659 Utyp := Underlying_Type (Base_Type (Utyp));
7661 -- Deal with untagged derivation of private views
7663 if Is_Untagged_Derivation (Typ) and then not Is_Conc then
7664 Utyp := Underlying_Type (Root_Type (Base_Type (Typ)));
7665 Ref := Unchecked_Convert_To (Utyp, Ref);
7667 -- The following is to prevent problems with UC see 1.156 RH ???
7669 Set_Assignment_OK (Ref);
7670 end if;
7672 -- If the underlying_type is a subtype, then we are dealing with the
7673 -- completion of a private type. We need to access the base type and
7674 -- generate a conversion to it.
7676 if Utyp /= Base_Type (Utyp) then
7677 pragma Assert (Is_Private_Type (Typ));
7678 Utyp := Base_Type (Utyp);
7679 Ref := Unchecked_Convert_To (Utyp, Ref);
7680 end if;
7682 -- Select the appropriate version of initialize
7684 if Has_Controlled_Component (Utyp) then
7685 Proc := TSS (Utyp, Deep_Name_Of (Initialize_Case));
7686 else
7687 Proc := Find_Prim_Op (Utyp, Name_Of (Initialize_Case));
7688 Check_Visibly_Controlled (Initialize_Case, Typ, Proc, Ref);
7689 end if;
7691 -- The object reference may need another conversion depending on the
7692 -- type of the formal and that of the actual.
7694 Ref := Convert_View (Proc, Ref);
7696 -- Generate:
7697 -- [Deep_]Initialize (Ref);
7699 return
7700 Make_Procedure_Call_Statement (Loc,
7701 Name =>
7702 New_Occurrence_Of (Proc, Loc),
7703 Parameter_Associations => New_List (Ref));
7704 end Make_Init_Call;
7706 ------------------------------
7707 -- Make_Local_Deep_Finalize --
7708 ------------------------------
7710 function Make_Local_Deep_Finalize
7711 (Typ : Entity_Id;
7712 Nam : Entity_Id) return Node_Id
7714 Loc : constant Source_Ptr := Sloc (Typ);
7715 Formals : List_Id;
7717 begin
7718 Formals := New_List (
7720 -- V : in out Typ
7722 Make_Parameter_Specification (Loc,
7723 Defining_Identifier => Make_Defining_Identifier (Loc, Name_V),
7724 In_Present => True,
7725 Out_Present => True,
7726 Parameter_Type => New_Occurrence_Of (Typ, Loc)),
7728 -- F : Boolean := True
7730 Make_Parameter_Specification (Loc,
7731 Defining_Identifier => Make_Defining_Identifier (Loc, Name_F),
7732 Parameter_Type => New_Occurrence_Of (Standard_Boolean, Loc),
7733 Expression => New_Occurrence_Of (Standard_True, Loc)));
7735 -- Add the necessary number of counters to represent the initialization
7736 -- state of an object.
7738 return
7739 Make_Subprogram_Body (Loc,
7740 Specification =>
7741 Make_Procedure_Specification (Loc,
7742 Defining_Unit_Name => Nam,
7743 Parameter_Specifications => Formals),
7745 Declarations => No_List,
7747 Handled_Statement_Sequence =>
7748 Make_Handled_Sequence_Of_Statements (Loc,
7749 Statements => Make_Deep_Record_Body (Finalize_Case, Typ, True)));
7750 end Make_Local_Deep_Finalize;
7752 ------------------------------------
7753 -- Make_Set_Finalize_Address_Call --
7754 ------------------------------------
7756 function Make_Set_Finalize_Address_Call
7757 (Loc : Source_Ptr;
7758 Typ : Entity_Id;
7759 Ptr_Typ : Entity_Id) return Node_Id
7761 Desig_Typ : constant Entity_Id :=
7762 Available_View (Designated_Type (Ptr_Typ));
7763 Fin_Mas_Id : constant Entity_Id := Finalization_Master (Ptr_Typ);
7764 Fin_Mas_Ref : Node_Id;
7765 Utyp : Entity_Id;
7767 begin
7768 -- If the context is a class-wide allocator, we use the class-wide type
7769 -- to obtain the proper Finalize_Address routine.
7771 if Is_Class_Wide_Type (Desig_Typ) then
7772 Utyp := Desig_Typ;
7774 else
7775 Utyp := Typ;
7777 if Is_Private_Type (Utyp) and then Present (Full_View (Utyp)) then
7778 Utyp := Full_View (Utyp);
7779 end if;
7781 if Is_Concurrent_Type (Utyp) then
7782 Utyp := Corresponding_Record_Type (Utyp);
7783 end if;
7784 end if;
7786 Utyp := Underlying_Type (Base_Type (Utyp));
7788 -- Deal with untagged derivation of private views. If the parent is
7789 -- now known to be protected, the finalization routine is the one
7790 -- defined on the corresponding record of the ancestor (corresponding
7791 -- records do not automatically inherit operations, but maybe they
7792 -- should???)
7794 if Is_Untagged_Derivation (Typ) then
7795 if Is_Protected_Type (Typ) then
7796 Utyp := Corresponding_Record_Type (Root_Type (Base_Type (Typ)));
7797 else
7798 Utyp := Underlying_Type (Root_Type (Base_Type (Typ)));
7800 if Is_Protected_Type (Utyp) then
7801 Utyp := Corresponding_Record_Type (Utyp);
7802 end if;
7803 end if;
7804 end if;
7806 -- If the underlying_type is a subtype, we are dealing with the
7807 -- completion of a private type. We need to access the base type and
7808 -- generate a conversion to it.
7810 if Utyp /= Base_Type (Utyp) then
7811 pragma Assert (Is_Private_Type (Typ));
7813 Utyp := Base_Type (Utyp);
7814 end if;
7816 Fin_Mas_Ref := New_Occurrence_Of (Fin_Mas_Id, Loc);
7818 -- If the call is from a build-in-place function, the Master parameter
7819 -- is actually a pointer. Dereference it for the call.
7821 if Is_Access_Type (Etype (Fin_Mas_Id)) then
7822 Fin_Mas_Ref := Make_Explicit_Dereference (Loc, Fin_Mas_Ref);
7823 end if;
7825 -- Generate:
7826 -- Set_Finalize_Address (<Ptr_Typ>FM, <Utyp>FD'Unrestricted_Access);
7828 return
7829 Make_Procedure_Call_Statement (Loc,
7830 Name =>
7831 New_Occurrence_Of (RTE (RE_Set_Finalize_Address), Loc),
7832 Parameter_Associations => New_List (
7833 Fin_Mas_Ref,
7834 Make_Attribute_Reference (Loc,
7835 Prefix =>
7836 New_Occurrence_Of (TSS (Utyp, TSS_Finalize_Address), Loc),
7837 Attribute_Name => Name_Unrestricted_Access)));
7838 end Make_Set_Finalize_Address_Call;
7840 --------------------------
7841 -- Make_Transient_Block --
7842 --------------------------
7844 function Make_Transient_Block
7845 (Loc : Source_Ptr;
7846 Action : Node_Id;
7847 Par : Node_Id) return Node_Id
7849 Decls : constant List_Id := New_List;
7850 Instrs : constant List_Id := New_List (Action);
7851 Block : Node_Id;
7852 Insert : Node_Id;
7854 begin
7855 -- Case where only secondary stack use is involved
7857 if VM_Target = No_VM
7858 and then Uses_Sec_Stack (Current_Scope)
7859 and then Nkind (Action) /= N_Simple_Return_Statement
7860 and then Nkind (Par) /= N_Exception_Handler
7861 then
7862 declare
7863 S : Entity_Id;
7865 begin
7866 S := Scope (Current_Scope);
7867 loop
7868 -- At the outer level, no need to release the sec stack
7870 if S = Standard_Standard then
7871 Set_Uses_Sec_Stack (Current_Scope, False);
7872 exit;
7874 -- In a function, only release the sec stack if the function
7875 -- does not return on the sec stack otherwise the result may
7876 -- be lost. The caller is responsible for releasing.
7878 elsif Ekind (S) = E_Function then
7879 Set_Uses_Sec_Stack (Current_Scope, False);
7881 if not Requires_Transient_Scope (Etype (S)) then
7882 Set_Uses_Sec_Stack (S, True);
7883 Check_Restriction (No_Secondary_Stack, Action);
7884 end if;
7886 exit;
7888 -- In a loop or entry we should install a block encompassing
7889 -- all the construct. For now just release right away.
7891 elsif Ekind_In (S, E_Entry, E_Loop) then
7892 exit;
7894 -- In a procedure or a block, we release on exit of the
7895 -- procedure or block. ??? memory leak can be created by
7896 -- recursive calls.
7898 elsif Ekind_In (S, E_Block, E_Procedure) then
7899 Set_Uses_Sec_Stack (S, True);
7900 Check_Restriction (No_Secondary_Stack, Action);
7901 Set_Uses_Sec_Stack (Current_Scope, False);
7902 exit;
7904 else
7905 S := Scope (S);
7906 end if;
7907 end loop;
7908 end;
7909 end if;
7911 -- Create the transient block. Set the parent now since the block itself
7912 -- is not part of the tree. The current scope is the E_Block entity
7913 -- that has been pushed by Establish_Transient_Scope.
7915 pragma Assert (Ekind (Current_Scope) = E_Block);
7916 Block :=
7917 Make_Block_Statement (Loc,
7918 Identifier => New_Occurrence_Of (Current_Scope, Loc),
7919 Declarations => Decls,
7920 Handled_Statement_Sequence =>
7921 Make_Handled_Sequence_Of_Statements (Loc, Statements => Instrs),
7922 Has_Created_Identifier => True);
7923 Set_Parent (Block, Par);
7925 -- Insert actions stuck in the transient scopes as well as all freezing
7926 -- nodes needed by those actions. Do not insert cleanup actions here,
7927 -- they will be transferred to the newly created block.
7929 Insert_Actions_In_Scope_Around
7930 (Action, Clean => False, Manage_SS => False);
7932 Insert := Prev (Action);
7933 if Present (Insert) then
7934 Freeze_All (First_Entity (Current_Scope), Insert);
7935 end if;
7937 -- Transfer cleanup actions to the newly created block
7939 declare
7940 Cleanup_Actions : List_Id
7941 renames Scope_Stack.Table (Scope_Stack.Last).
7942 Actions_To_Be_Wrapped (Cleanup);
7943 begin
7944 Set_Cleanup_Actions (Block, Cleanup_Actions);
7945 Cleanup_Actions := No_List;
7946 end;
7948 -- When the transient scope was established, we pushed the entry for the
7949 -- transient scope onto the scope stack, so that the scope was active
7950 -- for the installation of finalizable entities etc. Now we must remove
7951 -- this entry, since we have constructed a proper block.
7953 Pop_Scope;
7955 return Block;
7956 end Make_Transient_Block;
7958 ------------------------
7959 -- Node_To_Be_Wrapped --
7960 ------------------------
7962 function Node_To_Be_Wrapped return Node_Id is
7963 begin
7964 return Scope_Stack.Table (Scope_Stack.Last).Node_To_Be_Wrapped;
7965 end Node_To_Be_Wrapped;
7967 ----------------------------
7968 -- Set_Node_To_Be_Wrapped --
7969 ----------------------------
7971 procedure Set_Node_To_Be_Wrapped (N : Node_Id) is
7972 begin
7973 Scope_Stack.Table (Scope_Stack.Last).Node_To_Be_Wrapped := N;
7974 end Set_Node_To_Be_Wrapped;
7976 ----------------------------
7977 -- Store_Actions_In_Scope --
7978 ----------------------------
7980 procedure Store_Actions_In_Scope (AK : Scope_Action_Kind; L : List_Id) is
7981 SE : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
7982 Actions : List_Id renames SE.Actions_To_Be_Wrapped (AK);
7984 begin
7985 if No (Actions) then
7986 Actions := L;
7988 if Is_List_Member (SE.Node_To_Be_Wrapped) then
7989 Set_Parent (L, Parent (SE.Node_To_Be_Wrapped));
7990 else
7991 Set_Parent (L, SE.Node_To_Be_Wrapped);
7992 end if;
7994 Analyze_List (L);
7996 elsif AK = Before then
7997 Insert_List_After_And_Analyze (Last (Actions), L);
7999 else
8000 Insert_List_Before_And_Analyze (First (Actions), L);
8001 end if;
8002 end Store_Actions_In_Scope;
8004 ----------------------------------
8005 -- Store_After_Actions_In_Scope --
8006 ----------------------------------
8008 procedure Store_After_Actions_In_Scope (L : List_Id) is
8009 begin
8010 Store_Actions_In_Scope (After, L);
8011 end Store_After_Actions_In_Scope;
8013 -----------------------------------
8014 -- Store_Before_Actions_In_Scope --
8015 -----------------------------------
8017 procedure Store_Before_Actions_In_Scope (L : List_Id) is
8018 begin
8019 Store_Actions_In_Scope (Before, L);
8020 end Store_Before_Actions_In_Scope;
8022 -----------------------------------
8023 -- Store_Cleanup_Actions_In_Scope --
8024 -----------------------------------
8026 procedure Store_Cleanup_Actions_In_Scope (L : List_Id) is
8027 begin
8028 Store_Actions_In_Scope (Cleanup, L);
8029 end Store_Cleanup_Actions_In_Scope;
8031 --------------------------------
8032 -- Wrap_Transient_Declaration --
8033 --------------------------------
8035 -- If a transient scope has been established during the processing of the
8036 -- Expression of an Object_Declaration, it is not possible to wrap the
8037 -- declaration into a transient block as usual case, otherwise the object
8038 -- would be itself declared in the wrong scope. Therefore, all entities (if
8039 -- any) defined in the transient block are moved to the proper enclosing
8040 -- scope. Furthermore, if they are controlled variables they are finalized
8041 -- right after the declaration. The finalization list of the transient
8042 -- scope is defined as a renaming of the enclosing one so during their
8043 -- initialization they will be attached to the proper finalization list.
8044 -- For instance, the following declaration :
8046 -- X : Typ := F (G (A), G (B));
8048 -- (where G(A) and G(B) return controlled values, expanded as _v1 and _v2)
8049 -- is expanded into :
8051 -- X : Typ := [ complex Expression-Action ];
8052 -- [Deep_]Finalize (_v1);
8053 -- [Deep_]Finalize (_v2);
8055 procedure Wrap_Transient_Declaration (N : Node_Id) is
8056 Curr_S : Entity_Id;
8057 Encl_S : Entity_Id;
8059 begin
8060 Curr_S := Current_Scope;
8061 Encl_S := Scope (Curr_S);
8063 -- Insert all actions inluding cleanup generated while analyzing or
8064 -- expanding the transient context back into the tree. Manage the
8065 -- secondary stack when the object declaration appears in a library
8066 -- level package [body]. This is not needed for .NET/JVM as those do
8067 -- not support the secondary stack.
8069 Insert_Actions_In_Scope_Around
8070 (N => N,
8071 Clean => True,
8072 Manage_SS =>
8073 VM_Target = No_VM
8074 and then Uses_Sec_Stack (Curr_S)
8075 and then Nkind (N) = N_Object_Declaration
8076 and then Ekind_In (Encl_S, E_Package, E_Package_Body)
8077 and then Is_Library_Level_Entity (Encl_S));
8078 Pop_Scope;
8080 -- Relocate local entities declared within the transient scope to the
8081 -- enclosing scope. This action sets their Is_Public flag accordingly.
8083 Transfer_Entities (Curr_S, Encl_S);
8085 -- Mark the enclosing dynamic scope to ensure that the secondary stack
8086 -- is properly released upon exiting the said scope. This is not needed
8087 -- for .NET/JVM as those do not support the secondary stack.
8089 if VM_Target = No_VM and then Uses_Sec_Stack (Curr_S) then
8090 Curr_S := Enclosing_Dynamic_Scope (Curr_S);
8092 -- Do not mark a function that returns on the secondary stack as the
8093 -- reclamation is done by the caller.
8095 if Ekind (Curr_S) = E_Function
8096 and then Requires_Transient_Scope (Etype (Curr_S))
8097 then
8098 null;
8100 -- Otherwise mark the enclosing dynamic scope
8102 else
8103 Set_Uses_Sec_Stack (Curr_S);
8104 Check_Restriction (No_Secondary_Stack, N);
8105 end if;
8106 end if;
8107 end Wrap_Transient_Declaration;
8109 -------------------------------
8110 -- Wrap_Transient_Expression --
8111 -------------------------------
8113 procedure Wrap_Transient_Expression (N : Node_Id) is
8114 Loc : constant Source_Ptr := Sloc (N);
8115 Expr : Node_Id := Relocate_Node (N);
8116 Temp : constant Entity_Id := Make_Temporary (Loc, 'E', N);
8117 Typ : constant Entity_Id := Etype (N);
8119 begin
8120 -- Generate:
8122 -- Temp : Typ;
8123 -- declare
8124 -- M : constant Mark_Id := SS_Mark;
8125 -- procedure Finalizer is ... (See Build_Finalizer)
8127 -- begin
8128 -- Temp := <Expr>; -- general case
8129 -- Temp := (if <Expr> then True else False); -- boolean case
8131 -- at end
8132 -- Finalizer;
8133 -- end;
8135 -- A special case is made for Boolean expressions so that the back-end
8136 -- knows to generate a conditional branch instruction, if running with
8137 -- -fpreserve-control-flow. This ensures that a control flow change
8138 -- signalling the decision outcome occurs before the cleanup actions.
8140 if Opt.Suppress_Control_Flow_Optimizations
8141 and then Is_Boolean_Type (Typ)
8142 then
8143 Expr :=
8144 Make_If_Expression (Loc,
8145 Expressions => New_List (
8146 Expr,
8147 New_Occurrence_Of (Standard_True, Loc),
8148 New_Occurrence_Of (Standard_False, Loc)));
8149 end if;
8151 Insert_Actions (N, New_List (
8152 Make_Object_Declaration (Loc,
8153 Defining_Identifier => Temp,
8154 Object_Definition => New_Occurrence_Of (Typ, Loc)),
8156 Make_Transient_Block (Loc,
8157 Action =>
8158 Make_Assignment_Statement (Loc,
8159 Name => New_Occurrence_Of (Temp, Loc),
8160 Expression => Expr),
8161 Par => Parent (N))));
8163 Rewrite (N, New_Occurrence_Of (Temp, Loc));
8164 Analyze_And_Resolve (N, Typ);
8165 end Wrap_Transient_Expression;
8167 ------------------------------
8168 -- Wrap_Transient_Statement --
8169 ------------------------------
8171 procedure Wrap_Transient_Statement (N : Node_Id) is
8172 Loc : constant Source_Ptr := Sloc (N);
8173 New_Stmt : constant Node_Id := Relocate_Node (N);
8175 begin
8176 -- Generate:
8177 -- declare
8178 -- M : constant Mark_Id := SS_Mark;
8179 -- procedure Finalizer is ... (See Build_Finalizer)
8181 -- begin
8182 -- <New_Stmt>;
8184 -- at end
8185 -- Finalizer;
8186 -- end;
8188 Rewrite (N,
8189 Make_Transient_Block (Loc,
8190 Action => New_Stmt,
8191 Par => Parent (N)));
8193 -- With the scope stack back to normal, we can call analyze on the
8194 -- resulting block. At this point, the transient scope is being
8195 -- treated like a perfectly normal scope, so there is nothing
8196 -- special about it.
8198 -- Note: Wrap_Transient_Statement is called with the node already
8199 -- analyzed (i.e. Analyzed (N) is True). This is important, since
8200 -- otherwise we would get a recursive processing of the node when
8201 -- we do this Analyze call.
8203 Analyze (N);
8204 end Wrap_Transient_Statement;
8206 end Exp_Ch7;