1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2004 Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 2, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING. If not, write --
19 -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
20 -- MA 02111-1307, USA. --
22 -- GNAT was originally developed by the GNAT team at New York University. --
23 -- Extensive contributions were provided by Ada Core Technologies Inc. --
25 ------------------------------------------------------------------------------
27 with Atree
; use Atree
;
28 with Casing
; use Casing
;
29 with Debug
; use Debug
;
30 with Einfo
; use Einfo
;
31 with Errout
; use Errout
;
32 with Exp_Ch7
; use Exp_Ch7
;
33 with Exp_Util
; use Exp_Util
;
34 with Hostparm
; use Hostparm
;
35 with Inline
; use Inline
;
37 with Namet
; use Namet
;
38 with Nlists
; use Nlists
;
39 with Nmake
; use Nmake
;
41 with Rtsfind
; use Rtsfind
;
42 with Restrict
; use Restrict
;
43 with Rident
; use Rident
;
45 with Sem_Ch5
; use Sem_Ch5
;
46 with Sem_Ch8
; use Sem_Ch8
;
47 with Sem_Res
; use Sem_Res
;
48 with Sem_Util
; use Sem_Util
;
49 with Sinfo
; use Sinfo
;
50 with Sinput
; use Sinput
;
51 with Snames
; use Snames
;
52 with Stand
; use Stand
;
53 with Stringt
; use Stringt
;
54 with Targparm
; use Targparm
;
55 with Tbuild
; use Tbuild
;
56 with Uintp
; use Uintp
;
57 with Uname
; use Uname
;
59 package body Exp_Ch11
is
62 -- This list gathers the values SDn'Unrestricted_Access used to
63 -- construct the unit exception table. It is set to Empty_List if
64 -- there are no subprogram descriptors.
66 -----------------------
67 -- Local Subprograms --
68 -----------------------
70 procedure Expand_Exception_Handler_Tables
(HSS
: Node_Id
);
71 -- Subsidiary procedure called by Expand_Exception_Handlers if zero
72 -- cost exception handling is installed for this target. Replaces the
73 -- exception handler structure with appropriate labeled code and tables
74 -- that allow the zero cost exception handling circuits to find the
75 -- correct handler (see unit Ada.Exceptions for details).
77 procedure Generate_Subprogram_Descriptor
82 -- Procedure called to generate a subprogram descriptor. N is the
83 -- subprogram body node or, in the case of an imported subprogram, is
84 -- Empty, and Spec is the entity of the sunprogram. For details of the
85 -- required structure, see package System.Exceptions. The generated
86 -- subprogram descriptor is appended to Slist. Loc provides the
87 -- source location to be used for the generated descriptor.
89 ---------------------------
90 -- Expand_At_End_Handler --
91 ---------------------------
93 -- For a handled statement sequence that has a cleanup (At_End_Proc
94 -- field set), an exception handler of the following form is required:
101 -- Note: this exception handler is treated rather specially by
102 -- subsequent expansion in two respects:
104 -- The normal call to Undefer_Abort is omitted
105 -- The raise call does not do Defer_Abort
107 -- This is because the current tasking code seems to assume that
108 -- the call to the cleanup routine that is made from an exception
109 -- handler for the abort signal is called with aborts deferred.
111 -- This expansion is only done if we have front end exception handling.
112 -- If we have back end exception handling, then the AT END handler is
113 -- left alone, and cleanups (including the exceptional case) are handled
116 -- In the front end case, the exception handler described above handles
117 -- the exceptional case. The AT END handler is left in the generated tree
118 -- and the code generator (e.g. gigi) must still handle proper generation
119 -- of cleanup calls for the non-exceptional case.
121 procedure Expand_At_End_Handler
(HSS
: Node_Id
; Block
: Node_Id
) is
122 Clean
: constant Entity_Id
:= Entity
(At_End_Proc
(HSS
));
123 Loc
: constant Source_Ptr
:= Sloc
(Clean
);
128 pragma Assert
(Present
(Clean
));
129 pragma Assert
(No
(Exception_Handlers
(HSS
)));
131 -- Don't expand if back end exception handling active
133 if Exception_Mechanism
= Back_End_ZCX_Exceptions
then
137 -- Don't expand an At End handler if we have already had configurable
138 -- run-time violations, since likely this will just be a matter of
139 -- generating useless cascaded messages
141 if Configurable_Run_Time_Violations
> 0 then
145 if Restriction_Active
(No_Exception_Handlers
) then
149 if Present
(Block
) then
154 Make_Others_Choice
(Loc
);
155 Set_All_Others
(Ohandle
);
158 Make_Procedure_Call_Statement
(Loc
,
159 Name
=> New_Occurrence_Of
(Clean
, Loc
)),
160 Make_Raise_Statement
(Loc
));
162 Set_Exception_Handlers
(HSS
, New_List
(
163 Make_Exception_Handler
(Loc
,
164 Exception_Choices
=> New_List
(Ohandle
),
165 Statements
=> Stmnts
)));
167 Analyze_List
(Stmnts
, Suppress
=> All_Checks
);
168 Expand_Exception_Handlers
(HSS
);
170 if Present
(Block
) then
173 end Expand_At_End_Handler
;
175 -------------------------------------
176 -- Expand_Exception_Handler_Tables --
177 -------------------------------------
179 -- See Ada.Exceptions specification for full details of the data
180 -- structures that we need to construct here. As an example of the
181 -- transformation that is required, given the structure:
198 -- We transform this into:
220 -- HR2 : constant Handler_Record := (
224 -- Handler => L5'Address);
226 -- HR3 : constant Handler_Record := (
230 -- Handler => L4'Address);
236 -- HR1 : constant Handler_Record := (
240 -- Handler => L4'Address);
243 -- The exception handlers in the transformed version are marked with the
244 -- Zero_Cost_Handling flag set, and all gigi does in this case is simply
245 -- to put the handler code somewhere. It can optionally be put inline
246 -- between the goto L3 and the label <<L3>> (which is why we generate
247 -- that goto in the first place).
249 procedure Expand_Exception_Handler_Tables
(HSS
: Node_Id
) is
250 Loc
: constant Source_Ptr
:= Sloc
(HSS
);
251 Handlrs
: constant List_Id
:= Exception_Handlers
(HSS
);
252 Stms
: constant List_Id
:= Statements
(HSS
);
256 -- This is the list to which handlers are to be appended. It is
257 -- either the list for the enclosing subprogram, or the enclosing
258 -- selective accept statement (which will turn into a subprogram
259 -- during expansion later on).
261 L1
: constant Entity_Id
:=
262 Make_Defining_Identifier
(Loc
,
263 Chars
=> New_Internal_Name
('L'));
265 L2
: constant Entity_Id
:=
266 Make_Defining_Identifier
(Loc
,
267 Chars
=> New_Internal_Name
('L'));
276 Subp_Entity
: Entity_Id
;
277 -- This is the entity for the subprogram (or library level package)
278 -- to which the handler record is to be attached for later reference
279 -- in a subprogram descriptor for this entity.
281 procedure Append_To_Stms
(N
: Node_Id
);
282 -- Append given statement to the end of the statements of the
283 -- handled sequence of statements and analyze it in place.
285 function Inside_Selective_Accept
return Boolean;
286 -- This function is called if we are inside the scope of an entry
287 -- or task. It checks if the handler is appearing in the context
288 -- of a selective accept statement. If so, Hlist is set to
289 -- temporarily park the handlers in the N_Accept_Alternative.
290 -- node. They will subsequently be moved to the procedure entity
291 -- for the procedure built for this alternative. The statements that
292 -- follow the Accept within the alternative are not inside the Accept
293 -- for purposes of this test, and handlers that may appear within
294 -- them belong in the enclosing task procedure.
297 -- Sets the handler list corresponding to Subp_Entity
303 procedure Append_To_Stms
(N
: Node_Id
) is
305 Insert_After_And_Analyze
(Last
(Stms
), N
);
306 Set_Exception_Junk
(N
);
309 -----------------------------
310 -- Inside_Selective_Accept --
311 -----------------------------
313 function Inside_Selective_Accept
return Boolean is
315 Curr
: Node_Id
:= HSS
;
318 Parnt
:= Parent
(HSS
);
319 while Nkind
(Parnt
) /= N_Compilation_Unit
loop
320 if Nkind
(Parnt
) = N_Accept_Alternative
321 and then Curr
= Accept_Statement
(Parnt
)
323 if Present
(Accept_Handler_Records
(Parnt
)) then
324 Hlist
:= Accept_Handler_Records
(Parnt
);
327 Set_Accept_Handler_Records
(Parnt
, Hlist
);
333 Parnt
:= Parent
(Parnt
);
338 end Inside_Selective_Accept
;
344 procedure Set_Hlist
is
346 -- Never try to inline a subprogram with exception handlers
348 Set_Is_Inlined
(Subp_Entity
, False);
350 if Present
(Subp_Entity
)
351 and then Present
(Handler_Records
(Subp_Entity
))
353 Hlist
:= Handler_Records
(Subp_Entity
);
356 Set_Handler_Records
(Subp_Entity
, Hlist
);
360 -- Start of processing for Expand_Exception_Handler_Tables
363 -- Nothing to do if this handler has already been processed
365 if Zero_Cost_Handling
(HSS
) then
369 Set_Zero_Cost_Handling
(HSS
);
371 -- Find the parent subprogram or package scope containing this
372 -- exception frame. This should always find a real package or
373 -- subprogram. If it does not it will stop at Standard, but
374 -- this cannot legitimately occur.
376 -- We only stop at library level packages, for inner packages
377 -- we always attach handlers to the containing procedure.
379 Subp_Entity
:= Current_Scope
;
382 -- Never need tables expanded inside a generic template
384 if Is_Generic_Unit
(Subp_Entity
) then
387 -- Stop if we reached containing subprogram. Go to protected
388 -- subprogram if there is one defined.
390 elsif Ekind
(Subp_Entity
) = E_Function
391 or else Ekind
(Subp_Entity
) = E_Procedure
393 if Present
(Protected_Body_Subprogram
(Subp_Entity
)) then
394 Subp_Entity
:= Protected_Body_Subprogram
(Subp_Entity
);
400 -- Case of within an entry
402 elsif Is_Entry
(Subp_Entity
) then
404 -- Protected entry, use corresponding body subprogram
406 if Present
(Protected_Body_Subprogram
(Subp_Entity
)) then
407 Subp_Entity
:= Protected_Body_Subprogram
(Subp_Entity
);
411 -- Check if we are within a selective accept alternative
413 elsif Inside_Selective_Accept
then
415 -- As a side effect, Inside_Selective_Accept set Hlist,
416 -- in much the same manner as Set_Hlist, except that
417 -- the list involved was the one for the selective accept.
422 -- Case of within library level package
424 elsif Ekind
(Subp_Entity
) = E_Package
425 and then Is_Compilation_Unit
(Subp_Entity
)
427 if Is_Body_Name
(Unit_Name
(Get_Code_Unit
(HSS
))) then
428 Subp_Entity
:= Body_Entity
(Subp_Entity
);
436 elsif Ekind
(Subp_Entity
) = E_Task_Type
then
438 -- Check if we are within a selective accept alternative
440 if Inside_Selective_Accept
then
442 -- As a side effect, Inside_Selective_Accept set Hlist,
443 -- in much the same manner as Set_Hlist, except that the
444 -- list involved was the one for the selective accept.
448 -- Stop if we reached task type with task body procedure,
449 -- use the task body procedure.
451 elsif Present
(Get_Task_Body_Procedure
(Subp_Entity
)) then
452 Subp_Entity
:= Get_Task_Body_Procedure
(Subp_Entity
);
458 -- If we fall through, keep looking
460 Subp_Entity
:= Scope
(Subp_Entity
);
463 pragma Assert
(Subp_Entity
/= Standard_Standard
);
465 -- Analyze standard labels
467 Analyze_Label_Entity
(L1
);
468 Analyze_Label_Entity
(L2
);
470 Insert_Before_And_Analyze
(First
(Stms
),
472 Identifier
=> New_Occurrence_Of
(L1
, Loc
)));
473 Set_Exception_Junk
(First
(Stms
));
477 Identifier
=> New_Occurrence_Of
(L2
, Loc
)));
479 -- Loop through exception handlers
481 Handler
:= First_Non_Pragma
(Handlrs
);
482 while Present
(Handler
) loop
483 Set_Zero_Cost_Handling
(Handler
);
485 -- Add label at start of handler, and goto at the end
488 Make_Defining_Identifier
(Loc
,
489 Chars
=> New_Internal_Name
('L'));
491 Analyze_Label_Entity
(Lnn
);
495 Identifier
=> New_Occurrence_Of
(Lnn
, Loc
));
496 Set_Exception_Junk
(Item
);
497 Insert_Before_And_Analyze
(First
(Statements
(Handler
)), Item
);
499 -- Loop through choices
501 Choice
:= First
(Exception_Choices
(Handler
));
502 while Present
(Choice
) loop
504 -- Others (or all others) choice
506 if Nkind
(Choice
) = N_Others_Choice
then
507 if All_Others
(Choice
) then
508 E_Id
:= New_Occurrence_Of
(RTE
(RE_All_Others_Id
), Loc
);
510 E_Id
:= New_Occurrence_Of
(RTE
(RE_Others_Id
), Loc
);
513 -- Special case of VMS_Exception. Not clear what we will do
514 -- eventually here if and when we implement zero cost exceptions
515 -- on VMS. But at least for now, don't blow up trying to take
516 -- a garbage code address for such an exception.
518 elsif Is_VMS_Exception
(Entity
(Choice
)) then
519 E_Id
:= New_Occurrence_Of
(RTE
(RE_Null_Id
), Loc
);
521 -- Normal case of specific exception choice
525 Make_Attribute_Reference
(Loc
,
526 Prefix
=> New_Occurrence_Of
(Entity
(Choice
), Loc
),
527 Attribute_Name
=> Name_Identity
);
531 Make_Defining_Identifier
(Loc
,
532 Chars
=> New_Internal_Name
('H'));
535 Make_Attribute_Reference
(Loc
,
536 Prefix
=> New_Occurrence_Of
(HR_Ent
, Loc
),
537 Attribute_Name
=> Name_Unrestricted_Access
);
539 -- Now we need to add the entry for the new handler record to
540 -- the list of handler records for the current subprogram.
542 -- Normally we end up generating the handler records in exactly
543 -- the right order. Here right order means innermost first,
544 -- since the table will be searched sequentially. Since we
545 -- generally expand from outside to inside, the order is just
546 -- what we want, and we need to append the new entry to the
549 -- However, there are exceptions, notably in the case where
550 -- a generic body is inserted later on. See for example the
551 -- case of ACVC test C37213J, which has the following form:
553 -- generic package x ... end x;
564 -- package q is new x;
571 -- In this case, we will expand exception handler (2) first,
572 -- since the expansion of (1) is delayed till later when the
573 -- generic body is inserted. But (1) belongs before (2) in
576 -- Note that scopes are not totally ordered, because two
577 -- scopes can be in parallel blocks, so that it does not
578 -- matter what order these entries appear in. An ordering
579 -- relation exists if one scope is inside another, and what
580 -- we really want is some partial ordering.
582 -- A simple, not very efficient, but adequate algorithm to
583 -- achieve this partial ordering is to search the list for
584 -- the first entry containing the given scope, and put the
585 -- new entry just before it.
588 New_Scop
: constant Entity_Id
:= Current_Scope
;
592 Ent
:= First
(Hlist
);
594 -- If all searched, then we can just put the new
595 -- entry at the end of the list (it actually does
596 -- not matter where we put it in this case).
599 Append_To
(Hlist
, HL_Ref
);
602 -- If the current scope is within the scope of the
603 -- entry then insert the entry before to retain the
604 -- proper order as per above discussion.
606 -- Note that for equal entries, we just keep going,
607 -- which is fine, the entry will end up at the end
608 -- of the list where it belongs.
611 (New_Scop
, Scope
(Entity
(Prefix
(Ent
))))
613 Insert_Before
(Ent
, HL_Ref
);
616 -- Otherwise keep looking
625 Make_Object_Declaration
(Loc
,
626 Defining_Identifier
=> HR_Ent
,
627 Constant_Present
=> True,
628 Aliased_Present
=> True,
630 New_Occurrence_Of
(RTE
(RE_Handler_Record
), Loc
),
634 Expressions
=> New_List
(
635 Make_Attribute_Reference
(Loc
, -- Lo
636 Prefix
=> New_Occurrence_Of
(L1
, Loc
),
637 Attribute_Name
=> Name_Address
),
639 Make_Attribute_Reference
(Loc
, -- Hi
640 Prefix
=> New_Occurrence_Of
(L2
, Loc
),
641 Attribute_Name
=> Name_Address
),
645 Make_Attribute_Reference
(Loc
,
646 Prefix
=> New_Occurrence_Of
(Lnn
, Loc
), -- Handler
647 Attribute_Name
=> Name_Address
))));
649 Set_Handler_List_Entry
(Item
, HL_Ref
);
650 Set_Exception_Junk
(Item
);
651 Insert_After_And_Analyze
(Last
(Statements
(Handler
)), Item
);
652 Set_Is_Statically_Allocated
(HR_Ent
);
654 -- If this is a late insertion (from body instance) it is being
655 -- inserted in the component list of an already analyzed aggre-
656 -- gate, and must be analyzed explicitly.
658 Analyze_And_Resolve
(HL_Ref
, RTE
(RE_Handler_Record_Ptr
));
663 Next_Non_Pragma
(Handler
);
665 end Expand_Exception_Handler_Tables
;
667 -------------------------------
668 -- Expand_Exception_Handlers --
669 -------------------------------
671 procedure Expand_Exception_Handlers
(HSS
: Node_Id
) is
672 Handlrs
: constant List_Id
:= Exception_Handlers
(HSS
);
675 Others_Choice
: Boolean;
678 procedure Prepend_Call_To_Handler
680 Args
: List_Id
:= No_List
);
681 -- Routine to prepend a call to the procedure referenced by Proc at
682 -- the start of the handler code for the current Handler.
684 -----------------------------
685 -- Prepend_Call_To_Handler --
686 -----------------------------
688 procedure Prepend_Call_To_Handler
690 Args
: List_Id
:= No_List
)
692 Ent
: constant Entity_Id
:= RTE
(Proc
);
695 -- If we have no Entity, then we are probably in no run time mode
696 -- or some weird error has occured. In either case do do nothing!
698 if Present
(Ent
) then
700 Call
: constant Node_Id
:=
701 Make_Procedure_Call_Statement
(Loc
,
702 Name
=> New_Occurrence_Of
(RTE
(Proc
), Loc
),
703 Parameter_Associations
=> Args
);
706 Prepend_To
(Statements
(Handler
), Call
);
707 Analyze
(Call
, Suppress
=> All_Checks
);
710 end Prepend_Call_To_Handler
;
712 -- Start of processing for Expand_Exception_Handlers
715 -- Loop through handlers
717 Handler
:= First_Non_Pragma
(Handlrs
);
718 Handler_Loop
: while Present
(Handler
) loop
719 Loc
:= Sloc
(Handler
);
721 -- Remove source handler if gnat debug flag N is set
723 if Debug_Flag_Dot_X
and then Comes_From_Source
(Handler
) then
725 H
: constant Node_Id
:= Handler
;
727 Next_Non_Pragma
(Handler
);
729 goto Continue_Handler_Loop
;
734 -- If an exception occurrence is present, then we must declare it
735 -- and initialize it from the value stored in the TSD
738 -- name : Exception_Occurrence;
741 -- Save_Occurrence (name, Get_Current_Excep.all)
745 if Present
(Choice_Parameter
(Handler
)) then
747 Cparm
: constant Entity_Id
:= Choice_Parameter
(Handler
);
748 Clc
: constant Source_Ptr
:= Sloc
(Cparm
);
753 Make_Procedure_Call_Statement
(Loc
,
755 New_Occurrence_Of
(RTE
(RE_Save_Occurrence
), Loc
),
756 Parameter_Associations
=> New_List
(
757 New_Occurrence_Of
(Cparm
, Clc
),
758 Make_Explicit_Dereference
(Loc
,
759 Make_Function_Call
(Loc
,
760 Name
=> Make_Explicit_Dereference
(Loc
,
762 (RTE
(RE_Get_Current_Excep
), Loc
))))));
764 Mark_Rewrite_Insertion
(Save
);
765 Prepend
(Save
, Statements
(Handler
));
768 Make_Object_Declaration
(Clc
,
769 Defining_Identifier
=> Cparm
,
772 (RTE
(RE_Exception_Occurrence
), Clc
));
773 Set_No_Initialization
(Obj_Decl
, True);
776 Make_Exception_Handler
(Loc
,
777 Exception_Choices
=> Exception_Choices
(Handler
),
779 Statements
=> New_List
(
780 Make_Block_Statement
(Loc
,
781 Declarations
=> New_List
(Obj_Decl
),
782 Handled_Statement_Sequence
=>
783 Make_Handled_Sequence_Of_Statements
(Loc
,
784 Statements
=> Statements
(Handler
))))));
786 Analyze_List
(Statements
(Handler
), Suppress
=> All_Checks
);
790 -- The processing at this point is rather different for the
791 -- JVM case, so we completely separate the processing.
793 -- For the JVM case, we unconditionally call Update_Exception,
794 -- passing a call to the intrinsic function Current_Target_Exception
795 -- (see JVM version of Ada.Exceptions in 4jexcept.adb for details).
797 if Hostparm
.Java_VM
then
799 Arg
: constant Node_Id
:=
800 Make_Function_Call
(Loc
,
801 Name
=> New_Occurrence_Of
802 (RTE
(RE_Current_Target_Exception
), Loc
));
804 Prepend_Call_To_Handler
(RE_Update_Exception
, New_List
(Arg
));
807 -- For the normal case, we have to worry about the state of abort
808 -- deferral. Generally, we defer abort during runtime handling of
809 -- exceptions. When control is passed to the handler, then in the
810 -- normal case we undefer aborts. In any case this entire handling
811 -- is relevant only if aborts are allowed!
813 elsif Abort_Allowed
then
815 -- There are some special cases in which we do not do the
816 -- undefer. In particular a finalization (AT END) handler
817 -- wants to operate with aborts still deferred.
819 -- We also suppress the call if this is the special handler
820 -- for Abort_Signal, since if we are aborting, we want to keep
821 -- aborts deferred (one abort is enough thank you very much :-)
823 -- If abort really needs to be deferred the expander must add
824 -- this call explicitly, see Exp_Ch9.Expand_N_Asynchronous_Select.
827 Nkind
(First
(Exception_Choices
(Handler
))) = N_Others_Choice
;
830 or else Entity
(First
(Exception_Choices
(Handler
))) /=
834 and then All_Others
(First
(Exception_Choices
(Handler
))))
835 and then Abort_Allowed
837 Prepend_Call_To_Handler
(RE_Abort_Undefer
);
841 Next_Non_Pragma
(Handler
);
843 <<Continue_Handler_Loop
>>
845 end loop Handler_Loop
;
847 -- If all handlers got removed by gnatdN, then remove the list
850 and then Is_Empty_List
(Exception_Handlers
(HSS
))
852 Set_Exception_Handlers
(HSS
, No_List
);
855 -- The last step for expanding exception handlers is to expand the
856 -- exception tables if zero cost exception handling is active.
858 if Exception_Mechanism
= Front_End_ZCX_Exceptions
then
859 Expand_Exception_Handler_Tables
(HSS
);
861 end Expand_Exception_Handlers
;
863 ------------------------------------
864 -- Expand_N_Exception_Declaration --
865 ------------------------------------
868 -- exceptE : constant String := "A.B.EXCEP"; -- static data
869 -- except : exception_data := (
870 -- Handled_By_Other => False,
872 -- Name_Length => exceptE'Length,
873 -- Full_Name => exceptE'Address,
874 -- HTable_Ptr => null,
876 -- Raise_Hook => null,
879 -- (protecting test only needed if not at library level)
881 -- exceptF : Boolean := True -- static data
884 -- Register_Exception (except'Unchecked_Access);
887 procedure Expand_N_Exception_Declaration
(N
: Node_Id
) is
888 Loc
: constant Source_Ptr
:= Sloc
(N
);
889 Id
: constant Entity_Id
:= Defining_Identifier
(N
);
890 L
: List_Id
:= New_List
;
893 Name_Exname
: constant Name_Id
:= New_External_Name
(Chars
(Id
), 'E');
894 Exname
: constant Node_Id
:=
895 Make_Defining_Identifier
(Loc
, Name_Exname
);
898 -- There is no expansion needed when compiling for the JVM since the
899 -- JVM has a built-in exception mechanism. See 4jexcept.ads for details.
901 if Hostparm
.Java_VM
then
905 -- Definition of the external name: nam : constant String := "A.B.NAME";
908 Make_Object_Declaration
(Loc
,
909 Defining_Identifier
=> Exname
,
910 Constant_Present
=> True,
911 Object_Definition
=> New_Occurrence_Of
(Standard_String
, Loc
),
912 Expression
=> Make_String_Literal
(Loc
, Full_Qualified_Name
(Id
))));
914 Set_Is_Statically_Allocated
(Exname
);
916 -- Create the aggregate list for type Standard.Exception_Type:
917 -- Handled_By_Other component: False
919 Append_To
(L
, New_Occurrence_Of
(Standard_False
, Loc
));
921 -- Lang component: 'A'
924 Make_Character_Literal
(Loc
, Name_uA
, Get_Char_Code
('A')));
926 -- Name_Length component: Nam'Length
929 Make_Attribute_Reference
(Loc
,
930 Prefix
=> New_Occurrence_Of
(Exname
, Loc
),
931 Attribute_Name
=> Name_Length
));
933 -- Full_Name component: Standard.A_Char!(Nam'Address)
935 Append_To
(L
, Unchecked_Convert_To
(Standard_A_Char
,
936 Make_Attribute_Reference
(Loc
,
937 Prefix
=> New_Occurrence_Of
(Exname
, Loc
),
938 Attribute_Name
=> Name_Address
)));
940 -- HTable_Ptr component: null
942 Append_To
(L
, Make_Null
(Loc
));
944 -- Import_Code component: 0
946 Append_To
(L
, Make_Integer_Literal
(Loc
, 0));
948 -- Raise_Hook component: null
950 Append_To
(L
, Make_Null
(Loc
));
952 Set_Expression
(N
, Make_Aggregate
(Loc
, Expressions
=> L
));
953 Analyze_And_Resolve
(Expression
(N
), Etype
(Id
));
955 -- Register_Exception (except'Unchecked_Access);
957 if not Restriction_Active
(No_Exception_Handlers
)
958 and then not Restriction_Active
(No_Exception_Registration
)
961 Make_Procedure_Call_Statement
(Loc
,
962 Name
=> New_Occurrence_Of
(RTE
(RE_Register_Exception
), Loc
),
963 Parameter_Associations
=> New_List
(
964 Unchecked_Convert_To
(RTE
(RE_Exception_Data_Ptr
),
965 Make_Attribute_Reference
(Loc
,
966 Prefix
=> New_Occurrence_Of
(Id
, Loc
),
967 Attribute_Name
=> Name_Unrestricted_Access
)))));
969 Set_Register_Exception_Call
(Id
, First
(L
));
971 if not Is_Library_Level_Entity
(Id
) then
972 Flag_Id
:= Make_Defining_Identifier
(Loc
,
973 New_External_Name
(Chars
(Id
), 'F'));
976 Make_Object_Declaration
(Loc
,
977 Defining_Identifier
=> Flag_Id
,
979 New_Occurrence_Of
(Standard_Boolean
, Loc
),
981 New_Occurrence_Of
(Standard_True
, Loc
)));
983 Set_Is_Statically_Allocated
(Flag_Id
);
986 Make_Assignment_Statement
(Loc
,
987 Name
=> New_Occurrence_Of
(Flag_Id
, Loc
),
988 Expression
=> New_Occurrence_Of
(Standard_False
, Loc
)));
990 Insert_After_And_Analyze
(N
,
991 Make_Implicit_If_Statement
(N
,
992 Condition
=> New_Occurrence_Of
(Flag_Id
, Loc
),
993 Then_Statements
=> L
));
996 Insert_List_After_And_Analyze
(N
, L
);
1000 end Expand_N_Exception_Declaration
;
1002 ---------------------------------------------
1003 -- Expand_N_Handled_Sequence_Of_Statements --
1004 ---------------------------------------------
1006 procedure Expand_N_Handled_Sequence_Of_Statements
(N
: Node_Id
) is
1008 if Present
(Exception_Handlers
(N
))
1009 and then not Restriction_Active
(No_Exception_Handlers
)
1011 Expand_Exception_Handlers
(N
);
1014 -- The following code needs comments ???
1016 if Nkind
(Parent
(N
)) /= N_Package_Body
1017 and then Nkind
(Parent
(N
)) /= N_Accept_Statement
1018 and then not Delay_Cleanups
(Current_Scope
)
1020 Expand_Cleanup_Actions
(Parent
(N
));
1022 Set_First_Real_Statement
(N
, First
(Statements
(N
)));
1025 end Expand_N_Handled_Sequence_Of_Statements
;
1027 -------------------------------------
1028 -- Expand_N_Raise_Constraint_Error --
1029 -------------------------------------
1031 -- The only processing required is to adjust the condition to deal
1032 -- with the C/Fortran boolean case. This may well not be necessary,
1033 -- as all such conditions are generated by the expander and probably
1034 -- are all standard boolean, but who knows what strange optimization
1035 -- in future may require this adjustment!
1037 procedure Expand_N_Raise_Constraint_Error
(N
: Node_Id
) is
1039 Adjust_Condition
(Condition
(N
));
1040 end Expand_N_Raise_Constraint_Error
;
1042 ----------------------------------
1043 -- Expand_N_Raise_Program_Error --
1044 ----------------------------------
1046 -- The only processing required is to adjust the condition to deal
1047 -- with the C/Fortran boolean case. This may well not be necessary,
1048 -- as all such conditions are generated by the expander and probably
1049 -- are all standard boolean, but who knows what strange optimization
1050 -- in future may require this adjustment!
1052 procedure Expand_N_Raise_Program_Error
(N
: Node_Id
) is
1054 Adjust_Condition
(Condition
(N
));
1055 end Expand_N_Raise_Program_Error
;
1057 ------------------------------
1058 -- Expand_N_Raise_Statement --
1059 ------------------------------
1061 procedure Expand_N_Raise_Statement
(N
: Node_Id
) is
1062 Loc
: constant Source_Ptr
:= Sloc
(N
);
1068 -- There is no expansion needed for statement "raise <exception>;" when
1069 -- compiling for the JVM since the JVM has a built-in exception
1070 -- mechanism. However we need the keep the expansion for "raise;"
1071 -- statements. See 4jexcept.ads for details.
1073 if Present
(Name
(N
)) and then Hostparm
.Java_VM
then
1077 -- Don't expand a raise statement that does not come from source
1078 -- if we have already had configurable run-time violations, since
1079 -- most likely it will be junk cascaded nonsense.
1081 if Configurable_Run_Time_Violations
> 0
1082 and then not Comes_From_Source
(N
)
1087 -- Convert explicit raise of Program_Error, Constraint_Error, and
1088 -- Storage_Error into the corresponding raise (in High_Integrity_Mode
1089 -- all other raises will get normal expansion and be disallowed,
1090 -- but this is also faster in all modes).
1092 if Present
(Name
(N
)) and then Nkind
(Name
(N
)) = N_Identifier
then
1093 if Entity
(Name
(N
)) = Standard_Constraint_Error
then
1095 Make_Raise_Constraint_Error
(Loc
,
1096 Reason
=> CE_Explicit_Raise
));
1100 elsif Entity
(Name
(N
)) = Standard_Program_Error
then
1102 Make_Raise_Program_Error
(Loc
,
1103 Reason
=> PE_Explicit_Raise
));
1107 elsif Entity
(Name
(N
)) = Standard_Storage_Error
then
1109 Make_Raise_Storage_Error
(Loc
,
1110 Reason
=> SE_Explicit_Raise
));
1116 -- Case of name present, in this case we expand raise name to
1118 -- Raise_Exception (name'Identity, location_string);
1120 -- where location_string identifies the file/line of the raise
1122 if Present
(Name
(N
)) then
1124 Id
: Entity_Id
:= Entity
(Name
(N
));
1127 Build_Location_String
(Loc
);
1129 -- If the exception is a renaming, use the exception that it
1130 -- renames (which might be a predefined exception, e.g.).
1132 if Present
(Renamed_Object
(Id
)) then
1133 Id
:= Renamed_Object
(Id
);
1136 -- Build a C-compatible string in case of no exception handlers,
1137 -- since this is what the last chance handler is expecting.
1139 if Restriction_Active
(No_Exception_Handlers
) then
1141 -- Generate an empty message if configuration pragma
1142 -- Suppress_Exception_Locations is set for this unit.
1144 if Opt
.Exception_Locations_Suppressed
then
1147 Name_Len
:= Name_Len
+ 1;
1150 Name_Buffer
(Name_Len
) := ASCII
.NUL
;
1154 if Opt
.Exception_Locations_Suppressed
then
1158 Str
:= String_From_Name_Buffer
;
1160 -- For VMS exceptions, convert the raise into a call to
1161 -- lib$stop so it will be handled by __gnat_error_handler.
1163 if Is_VMS_Exception
(Id
) then
1165 Excep_Image
: String_Id
;
1169 if Present
(Interface_Name
(Id
)) then
1170 Excep_Image
:= Strval
(Interface_Name
(Id
));
1172 Get_Name_String
(Chars
(Id
));
1174 Excep_Image
:= String_From_Name_Buffer
;
1177 if Exception_Code
(Id
) /= No_Uint
then
1179 Make_Integer_Literal
(Loc
, Exception_Code
(Id
));
1182 Unchecked_Convert_To
(Standard_Integer
,
1183 Make_Function_Call
(Loc
,
1184 Name
=> New_Occurrence_Of
1185 (RTE
(RE_Import_Value
), Loc
),
1186 Parameter_Associations
=> New_List
1187 (Make_String_Literal
(Loc
,
1188 Strval
=> Excep_Image
))));
1192 Make_Procedure_Call_Statement
(Loc
,
1194 New_Occurrence_Of
(RTE
(RE_Lib_Stop
), Loc
),
1195 Parameter_Associations
=> New_List
(Cond
)));
1196 Analyze_And_Resolve
(Cond
, Standard_Integer
);
1199 -- Not VMS exception case, convert raise to call to the
1200 -- Raise_Exception routine.
1204 Make_Procedure_Call_Statement
(Loc
,
1205 Name
=> New_Occurrence_Of
(RTE
(RE_Raise_Exception
), Loc
),
1206 Parameter_Associations
=> New_List
(
1207 Make_Attribute_Reference
(Loc
,
1209 Attribute_Name
=> Name_Identity
),
1210 Make_String_Literal
(Loc
,
1215 -- Case of no name present (reraise). We rewrite the raise to:
1217 -- Reraise_Occurrence_Always (EO);
1219 -- where EO is the current exception occurrence. If the current handler
1220 -- does not have a choice parameter specification, then we provide one.
1223 -- Find innermost enclosing exception handler (there must be one,
1224 -- since the semantics has already verified that this raise statement
1225 -- is valid, and a raise with no arguments is only permitted in the
1226 -- context of an exception handler.
1228 Ehand
:= Parent
(N
);
1229 while Nkind
(Ehand
) /= N_Exception_Handler
loop
1230 Ehand
:= Parent
(Ehand
);
1233 -- Make exception choice parameter if none present. Note that we do
1234 -- not need to put the entity on the entity chain, since no one will
1235 -- be referencing this entity by normal visibility methods.
1237 if No
(Choice_Parameter
(Ehand
)) then
1238 E
:= Make_Defining_Identifier
(Loc
, New_Internal_Name
('E'));
1239 Set_Choice_Parameter
(Ehand
, E
);
1240 Set_Ekind
(E
, E_Variable
);
1241 Set_Etype
(E
, RTE
(RE_Exception_Occurrence
));
1242 Set_Scope
(E
, Current_Scope
);
1245 -- Now rewrite the raise as a call to Reraise. A special case arises
1246 -- if this raise statement occurs in the context of a handler for
1247 -- all others (i.e. an at end handler). in this case we avoid
1248 -- the call to defer abort, cleanup routines are expected to be
1249 -- called in this case with aborts deferred.
1252 Ech
: constant Node_Id
:= First
(Exception_Choices
(Ehand
));
1256 if Nkind
(Ech
) = N_Others_Choice
1257 and then All_Others
(Ech
)
1259 Ent
:= RTE
(RE_Reraise_Occurrence_No_Defer
);
1261 Ent
:= RTE
(RE_Reraise_Occurrence_Always
);
1265 Make_Procedure_Call_Statement
(Loc
,
1266 Name
=> New_Occurrence_Of
(Ent
, Loc
),
1267 Parameter_Associations
=> New_List
(
1268 New_Occurrence_Of
(Choice_Parameter
(Ehand
), Loc
))));
1273 end Expand_N_Raise_Statement
;
1275 ----------------------------------
1276 -- Expand_N_Raise_Storage_Error --
1277 ----------------------------------
1279 -- The only processing required is to adjust the condition to deal
1280 -- with the C/Fortran boolean case. This may well not be necessary,
1281 -- as all such conditions are generated by the expander and probably
1282 -- are all standard boolean, but who knows what strange optimization
1283 -- in future may require this adjustment!
1285 procedure Expand_N_Raise_Storage_Error
(N
: Node_Id
) is
1287 Adjust_Condition
(Condition
(N
));
1288 end Expand_N_Raise_Storage_Error
;
1290 ------------------------------
1291 -- Expand_N_Subprogram_Info --
1292 ------------------------------
1294 procedure Expand_N_Subprogram_Info
(N
: Node_Id
) is
1295 Loc
: constant Source_Ptr
:= Sloc
(N
);
1298 -- For now, we replace an Expand_N_Subprogram_Info node with an
1299 -- attribute reference that gives the address of the procedure.
1300 -- This is because gigi does not yet recognize this node, and
1301 -- for the initial targets, this is the right value anyway.
1304 Make_Attribute_Reference
(Loc
,
1305 Prefix
=> Identifier
(N
),
1306 Attribute_Name
=> Name_Code_Address
));
1308 Analyze_And_Resolve
(N
, RTE
(RE_Code_Loc
));
1309 end Expand_N_Subprogram_Info
;
1311 ------------------------------------
1312 -- Generate_Subprogram_Descriptor --
1313 ------------------------------------
1315 procedure Generate_Subprogram_Descriptor
1330 if Exception_Mechanism
/= Front_End_ZCX_Exceptions
then
1334 if Restriction_Active
(No_Exception_Handlers
) then
1338 -- Suppress descriptor if we are not generating code. This happens
1339 -- in the case of a -gnatc -gnatt compilation where we force generics
1340 -- to be generated, but we still don't want exception tables.
1342 if Operating_Mode
/= Generate_Code
then
1346 -- Suppress descriptor if we are in No_Exceptions restrictions mode,
1347 -- since we can never propagate exceptions in any case in this mode.
1348 -- The same consideration applies for No_Exception_Handlers (which
1349 -- is also set in High_Integrity_Mode).
1351 if Restriction_Active
(No_Exceptions
)
1352 or Restriction_Active
(No_Exception_Handlers
)
1357 -- Suppress descriptor if we are inside a generic. There are two
1358 -- ways that we can tell that, depending on what is going on. If
1359 -- we are actually inside the processing for a generic right now,
1360 -- then Expander_Active will be reset. If we are outside the
1361 -- generic, then we will see the generic entity.
1363 if not Expander_Active
then
1367 -- Suppress descriptor is subprogram is marked as eliminated, for
1368 -- example if this is a subprogram created to analyze a default
1369 -- expression with potential side effects. Ditto if it is nested
1370 -- within an eliminated subprogram, for example a cleanup action.
1377 while Scop
/= Standard_Standard
loop
1378 if Is_Generic_Unit
(Scop
) or else Is_Eliminated
(Scop
) then
1382 Scop
:= Scope
(Scop
);
1386 -- Suppress descriptor for original protected subprogram (we will
1387 -- be called again later to generate the descriptor for the actual
1388 -- protected body subprogram.) This does not apply to barrier
1389 -- functions which are there own protected subprogram.
1391 if Is_Subprogram
(Spec
)
1392 and then Present
(Protected_Body_Subprogram
(Spec
))
1393 and then Protected_Body_Subprogram
(Spec
) /= Spec
1398 -- Suppress descriptors for packages unless they have at least one
1399 -- handler. The binder will generate the dummy (no handler) descriptors
1400 -- for elaboration procedures. We can't do it here, because we don't
1401 -- know if an elaboration routine does in fact exist.
1403 -- If there is at least one handler for the package spec or body
1404 -- then most certainly an elaboration routine must exist, so we
1405 -- can safely reference it.
1407 if (Nkind
(N
) = N_Package_Declaration
1409 Nkind
(N
) = N_Package_Body
)
1410 and then No
(Handler_Records
(Spec
))
1415 -- Suppress all subprogram descriptors for the file System.Exceptions.
1416 -- We similarly suppress subprogram descriptors for Ada.Exceptions.
1417 -- These are all init procs for types which cannot raise exceptions.
1418 -- The reason this is done is that otherwise we get embarassing
1419 -- elaboration dependencies.
1421 Get_Name_String
(Unit_File_Name
(Current_Sem_Unit
));
1423 if Name_Buffer
(1 .. 12) = "s-except.ads"
1425 Name_Buffer
(1 .. 12) = "a-except.ads"
1430 -- Similarly, we need to suppress entries for System.Standard_Library,
1431 -- since otherwise we get elaboration circularities. Again, this would
1432 -- better be done with a Suppress_Initialization pragma :-)
1434 if Name_Buffer
(1 .. 11) = "s-stalib.ad" then
1438 -- For now, also suppress entries for s-stoele because we have
1439 -- some kind of unexplained error there ???
1441 if Name_Buffer
(1 .. 11) = "s-stoele.ad" then
1445 -- And also for g-htable, because it cannot raise exceptions,
1446 -- and generates some kind of elaboration order problem.
1448 if Name_Buffer
(1 .. 11) = "g-htable.ad" then
1452 -- Suppress subprogram descriptor if already generated. This happens
1453 -- in the case of late generation from Delay_Subprogram_Descriptors
1454 -- beging set (where there is more than one instantiation in the list)
1456 if Has_Subprogram_Descriptor
(Spec
) then
1459 Set_Has_Subprogram_Descriptor
(Spec
);
1462 -- Never generate descriptors for inlined bodies
1464 if Analyzing_Inlined_Bodies
then
1468 -- Here we definitely are going to generate a subprogram descriptor
1471 Hnum
: Nat
:= Homonym_Number
(Spec
);
1479 Make_Defining_Identifier
(Loc
,
1480 Chars
=> New_External_Name
(Chars
(Spec
), "SD", Hnum
));
1483 if No
(Handler_Records
(Spec
)) then
1487 Hrc
:= Handler_Records
(Spec
);
1488 Numh
:= List_Length
(Hrc
);
1493 -- We need a static subtype for the declaration of the subprogram
1494 -- descriptor. For the case of 0-3 handlers we can use one of the
1495 -- predefined subtypes in System.Exceptions. For more handlers,
1496 -- we build our own subtype here.
1500 Dtyp
:= RTE
(RE_Subprogram_Descriptor_0
);
1503 Dtyp
:= RTE
(RE_Subprogram_Descriptor_1
);
1506 Dtyp
:= RTE
(RE_Subprogram_Descriptor_2
);
1509 Dtyp
:= RTE
(RE_Subprogram_Descriptor_3
);
1513 Make_Defining_Identifier
(Loc
,
1514 Chars
=> New_Internal_Name
('T'));
1516 -- Set the constructed type as global, since we will be
1517 -- referencing the object that is of this type globally
1519 Set_Is_Statically_Allocated
(Dtyp
);
1522 Make_Subtype_Declaration
(Loc
,
1523 Defining_Identifier
=> Dtyp
,
1524 Subtype_Indication
=>
1525 Make_Subtype_Indication
(Loc
,
1527 New_Occurrence_Of
(RTE
(RE_Subprogram_Descriptor
), Loc
),
1529 Make_Index_Or_Discriminant_Constraint
(Loc
,
1530 Constraints
=> New_List
(
1531 Make_Integer_Literal
(Loc
, Numh
)))));
1533 Append
(Decl
, Slist
);
1535 -- We analyze the descriptor for the subprogram and package
1536 -- case, but not for the imported subprogram case (it will
1537 -- be analyzed when the freeze entity actions are analyzed.
1543 Set_Exception_Junk
(Decl
);
1546 -- Prepare the code address entry for the table entry. For the normal
1547 -- case of being within a procedure, this is simply:
1551 -- where P is the procedure, but for the package case, it is
1553 -- P'Elab_Body'Code_Address
1554 -- P'Elab_Spec'Code_Address
1556 -- for the body and spec respectively. Note that we do our own
1557 -- analysis of these attribute references, because we know in this
1558 -- case that the prefix of ELab_Body/Spec is a visible package,
1559 -- which can be referenced directly instead of using the general
1560 -- case expansion for these attributes.
1562 if Ekind
(Spec
) = E_Package
then
1564 Make_Attribute_Reference
(Loc
,
1565 Prefix
=> New_Occurrence_Of
(Spec
, Loc
),
1566 Attribute_Name
=> Name_Elab_Spec
);
1567 Set_Etype
(Code
, Standard_Void_Type
);
1568 Set_Analyzed
(Code
);
1570 elsif Ekind
(Spec
) = E_Package_Body
then
1572 Make_Attribute_Reference
(Loc
,
1573 Prefix
=> New_Occurrence_Of
(Spec_Entity
(Spec
), Loc
),
1574 Attribute_Name
=> Name_Elab_Body
);
1575 Set_Etype
(Code
, Standard_Void_Type
);
1576 Set_Analyzed
(Code
);
1579 Code
:= New_Occurrence_Of
(Spec
, Loc
);
1583 Make_Attribute_Reference
(Loc
,
1585 Attribute_Name
=> Name_Code_Address
);
1587 Set_Etype
(Code
, RTE
(RE_Address
));
1588 Set_Analyzed
(Code
);
1590 -- Now we can build the subprogram descriptor
1593 Make_Object_Declaration
(Loc
,
1594 Defining_Identifier
=> Ent
,
1595 Constant_Present
=> True,
1596 Aliased_Present
=> True,
1597 Object_Definition
=> New_Occurrence_Of
(Dtyp
, Loc
),
1600 Make_Aggregate
(Loc
,
1601 Expressions
=> New_List
(
1602 Make_Integer_Literal
(Loc
, Numh
), -- Num_Handlers
1608 -- Make_Subprogram_Info (Loc, -- Subprogram_Info
1610 -- New_Occurrence_Of (Spec, Loc)),
1612 New_Copy_Tree
(Code
),
1614 Make_Aggregate
(Loc
, -- Handler_Records
1615 Expressions
=> Hrc
))));
1617 Set_Exception_Junk
(Sdes
);
1618 Set_Is_Subprogram_Descriptor
(Sdes
);
1620 Append
(Sdes
, Slist
);
1622 -- We analyze the descriptor for the subprogram and package case,
1623 -- but not for the imported subprogram case (it will be analyzed
1624 -- when the freeze entity actions are analyzed.
1630 -- We can now pop the scope used for analyzing the descriptor
1634 -- We need to set the descriptor as statically allocated, since
1635 -- it will be referenced from the unit exception table.
1637 Set_Is_Statically_Allocated
(Ent
);
1639 -- Append the resulting descriptor to the list. We do this only
1640 -- if we are in the main unit. You might think that we could
1641 -- simply skip generating the descriptors completely if we are
1642 -- not in the main unit, but in fact this is not the case, since
1643 -- we have problems with inconsistent serial numbers for internal
1644 -- names if we do this.
1646 if In_Extended_Main_Code_Unit
(Spec
) then
1648 Make_Attribute_Reference
(Loc
,
1649 Prefix
=> New_Occurrence_Of
(Ent
, Loc
),
1650 Attribute_Name
=> Name_Unrestricted_Access
));
1652 Unit_Exception_Table_Present
:= True;
1655 end Generate_Subprogram_Descriptor
;
1657 ------------------------------------------------------------
1658 -- Generate_Subprogram_Descriptor_For_Imported_Subprogram --
1659 ------------------------------------------------------------
1661 procedure Generate_Subprogram_Descriptor_For_Imported_Subprogram
1666 Generate_Subprogram_Descriptor
(Empty
, Sloc
(Spec
), Spec
, Slist
);
1667 end Generate_Subprogram_Descriptor_For_Imported_Subprogram
;
1669 ------------------------------------------------
1670 -- Generate_Subprogram_Descriptor_For_Package --
1671 ------------------------------------------------
1673 procedure Generate_Subprogram_Descriptor_For_Package
1680 -- If N is empty with prior errors, ignore
1682 if Total_Errors_Detected
/= 0 and then No
(N
) then
1686 -- Do not generate if no exceptions
1688 if Restriction_Active
(No_Exception_Handlers
) then
1692 -- Otherwise generate descriptor
1694 Adecl
:= Aux_Decls_Node
(Parent
(N
));
1696 if No
(Actions
(Adecl
)) then
1697 Set_Actions
(Adecl
, New_List
);
1700 Generate_Subprogram_Descriptor
(N
, Sloc
(N
), Spec
, Actions
(Adecl
));
1701 end Generate_Subprogram_Descriptor_For_Package
;
1703 ---------------------------------------------------
1704 -- Generate_Subprogram_Descriptor_For_Subprogram --
1705 ---------------------------------------------------
1707 procedure Generate_Subprogram_Descriptor_For_Subprogram
1712 -- If we have no subprogram body and prior errors, ignore
1714 if Total_Errors_Detected
/= 0 and then No
(N
) then
1718 -- Do not generate if no exceptions
1720 if Restriction_Active
(No_Exception_Handlers
) then
1724 -- Else generate descriptor
1727 HSS
: constant Node_Id
:= Handled_Statement_Sequence
(N
);
1730 if No
(Exception_Handlers
(HSS
)) then
1731 Generate_Subprogram_Descriptor
1732 (N
, Sloc
(N
), Spec
, Statements
(HSS
));
1734 Generate_Subprogram_Descriptor
1736 Spec
, Statements
(Last
(Exception_Handlers
(HSS
))));
1739 end Generate_Subprogram_Descriptor_For_Subprogram
;
1741 -----------------------------------
1742 -- Generate_Unit_Exception_Table --
1743 -----------------------------------
1745 -- The only remaining thing to generate here is to generate the
1746 -- reference to the subprogram descriptor chain. See Ada.Exceptions
1747 -- for details of required data structures.
1749 procedure Generate_Unit_Exception_Table
is
1750 Loc
: constant Source_Ptr
:= No_Location
;
1754 Next_Ent
: Entity_Id
;
1758 -- Nothing to be done if zero length exceptions not active
1760 if Exception_Mechanism
/= Front_End_ZCX_Exceptions
then
1764 -- Nothing to do if no exceptions
1766 if Restriction_Active
(No_Exception_Handlers
) then
1770 -- Remove any entries from SD_List that correspond to eliminated
1773 Ent
:= First
(SD_List
);
1774 while Present
(Ent
) loop
1775 Next_Ent
:= Next
(Ent
);
1776 if Is_Eliminated
(Scope
(Entity
(Prefix
(Ent
)))) then
1777 Remove
(Ent
); -- After this, there is no Next (Ent) anymore
1783 -- Nothing to do if no unit exception table present.
1784 -- An empty table can result from subprogram elimination,
1785 -- in such a case, eliminate the exception table itself.
1787 if Is_Empty_List
(SD_List
) then
1788 Unit_Exception_Table_Present
:= False;
1792 -- Do not generate table in a generic
1794 if Inside_A_Generic
then
1798 -- Generate the unit exception table
1800 -- subtype Tnn is Subprogram_Descriptors_Record (Num);
1801 -- __gnat_unitname__SDP : aliased constant Tnn :=
1803 -- (sub1'unrestricted_access,
1804 -- sub2'unrestricted_access,
1806 -- subNum'unrestricted_access));
1808 Num
:= List_Length
(SD_List
);
1811 Make_Defining_Identifier
(Loc
,
1812 Chars
=> New_Internal_Name
('T'));
1814 Insert_Library_Level_Action
(
1815 Make_Subtype_Declaration
(Loc
,
1816 Defining_Identifier
=> Stent
,
1817 Subtype_Indication
=>
1818 Make_Subtype_Indication
(Loc
,
1821 (RTE
(RE_Subprogram_Descriptors_Record
), Loc
),
1823 Make_Index_Or_Discriminant_Constraint
(Loc
,
1824 Constraints
=> New_List
(
1825 Make_Integer_Literal
(Loc
, Num
))))));
1827 Set_Is_Statically_Allocated
(Stent
);
1829 Get_External_Unit_Name_String
(Unit_Name
(Main_Unit
));
1830 Name_Buffer
(1 + 7 .. Name_Len
+ 7) := Name_Buffer
(1 .. Name_Len
);
1831 Name_Buffer
(1 .. 7) := "__gnat_";
1832 Name_Len
:= Name_Len
+ 7;
1833 Add_Str_To_Name_Buffer
("__SDP");
1836 Make_Defining_Identifier
(Loc
,
1837 Chars
=> Name_Find
);
1839 Get_Name_String
(Chars
(Ent
));
1840 Set_Interface_Name
(Ent
,
1841 Make_String_Literal
(Loc
, Strval
=> String_From_Name_Buffer
));
1844 Make_Object_Declaration
(Loc
,
1845 Defining_Identifier
=> Ent
,
1846 Object_Definition
=> New_Occurrence_Of
(Stent
, Loc
),
1847 Constant_Present
=> True,
1848 Aliased_Present
=> True,
1850 Make_Aggregate
(Loc
,
1852 Make_Integer_Literal
(Loc
, List_Length
(SD_List
)),
1854 Make_Aggregate
(Loc
,
1855 Expressions
=> SD_List
))));
1857 Insert_Library_Level_Action
(Decl
);
1859 Set_Is_Exported
(Ent
, True);
1860 Set_Is_Public
(Ent
, True);
1861 Set_Is_Statically_Allocated
(Ent
, True);
1863 Get_Name_String
(Chars
(Ent
));
1864 Set_Interface_Name
(Ent
,
1865 Make_String_Literal
(Loc
,
1866 Strval
=> String_From_Name_Buffer
));
1868 end Generate_Unit_Exception_Table
;
1874 procedure Initialize
is
1876 SD_List
:= Empty_List
;
1879 ----------------------
1880 -- Is_Non_Ada_Error --
1881 ----------------------
1883 function Is_Non_Ada_Error
(E
: Entity_Id
) return Boolean is
1885 if not OpenVMS_On_Target
then
1889 Get_Name_String
(Chars
(E
));
1891 -- Note: it is a little irregular for the body of exp_ch11 to know
1892 -- the details of the encoding scheme for names, but on the other
1893 -- hand, gigi knows them, and this is for gigi's benefit anyway!
1895 if Name_Buffer
(1 .. 30) /= "system__aux_dec__non_ada_error" then
1900 end Is_Non_Ada_Error
;
1902 ----------------------------
1903 -- Remove_Handler_Entries --
1904 ----------------------------
1906 procedure Remove_Handler_Entries
(N
: Node_Id
) is
1907 function Check_Handler_Entry
(N
: Node_Id
) return Traverse_Result
;
1908 -- This function checks one node for a possible reference to a
1909 -- handler entry that must be deleted. it always returns OK.
1911 function Remove_All_Handler_Entries
is new
1912 Traverse_Func
(Check_Handler_Entry
);
1913 -- This defines the traversal operation
1915 Discard
: Traverse_Result
;
1916 pragma Warnings
(Off
, Discard
);
1918 function Check_Handler_Entry
(N
: Node_Id
) return Traverse_Result
is
1920 if Nkind
(N
) = N_Object_Declaration
then
1922 if Present
(Handler_List_Entry
(N
)) then
1923 Remove
(Handler_List_Entry
(N
));
1924 Delete_Tree
(Handler_List_Entry
(N
));
1925 Set_Handler_List_Entry
(N
, Empty
);
1927 elsif Is_Subprogram_Descriptor
(N
) then
1932 SDN
:= First
(SD_List
);
1933 while Present
(SDN
) loop
1934 if Defining_Identifier
(N
) = Entity
(Prefix
(SDN
)) then
1947 end Check_Handler_Entry
;
1949 -- Start of processing for Remove_Handler_Entries
1952 if Exception_Mechanism
= Front_End_ZCX_Exceptions
then
1953 Discard
:= Remove_All_Handler_Entries
(N
);
1955 end Remove_Handler_Entries
;