1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2010, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 ------------------------------------------------------------------------------
26 pragma Style_Checks
(All_Checks
);
27 -- Turn off subprogram body ordering check. Subprograms are in order
28 -- by RM section rather than alphabetical
30 with Sinfo
.CN
; use Sinfo
.CN
;
35 -- Local subprograms, used only in this chapter
37 function P_Defining_Designator
return Node_Id
;
38 function P_Defining_Operator_Symbol
return Node_Id
;
39 function P_Return_Object_Declaration
return Node_Id
;
41 procedure P_Return_Subtype_Indication
(Decl_Node
: Node_Id
);
42 -- Decl_Node is a N_Object_Declaration.
43 -- Set the Null_Exclusion_Present and Object_Definition fields of
46 procedure Check_Junk_Semicolon_Before_Return
;
48 -- Check for common error of junk semicolon before RETURN keyword of
49 -- function specification. If present, skip over it with appropriate
50 -- error message, leaving Scan_Ptr pointing to the RETURN after. This
51 -- routine also deals with a possibly misspelled version of Return.
53 ----------------------------------------
54 -- Check_Junk_Semicolon_Before_Return --
55 ----------------------------------------
57 procedure Check_Junk_Semicolon_Before_Return
is
58 Scan_State
: Saved_Scan_State
;
61 if Token
= Tok_Semicolon
then
62 Save_Scan_State
(Scan_State
);
63 Scan
; -- past the semicolon
65 if Token
= Tok_Return
then
66 Restore_Scan_State
(Scan_State
);
67 Error_Msg_SC
-- CODEFIX
68 ("|extra "";"" ignored");
69 Scan
; -- rescan past junk semicolon
71 Restore_Scan_State
(Scan_State
);
74 elsif Bad_Spelling_Of
(Tok_Return
) then
77 end Check_Junk_Semicolon_Before_Return
;
79 -----------------------------------------------------
80 -- 6.1 Subprogram (Also 6.3, 8.5.4, 10.1.3, 12.3) --
81 -----------------------------------------------------
83 -- This routine scans out a subprogram declaration, subprogram body,
84 -- subprogram renaming declaration or subprogram generic instantiation.
85 -- It also handles the new Ada 2012 parameterized expression form
87 -- SUBPROGRAM_DECLARATION ::=
88 -- SUBPROGRAM_SPECIFICATION
89 -- [ASPECT_SPECIFICATIONS];
91 -- ABSTRACT_SUBPROGRAM_DECLARATION ::=
92 -- SUBPROGRAM_SPECIFICATION is abstract
93 -- [ASPECT_SPECIFICATIONS];
95 -- SUBPROGRAM_SPECIFICATION ::=
96 -- procedure DEFINING_PROGRAM_UNIT_NAME PARAMETER_PROFILE
97 -- | function DEFINING_DESIGNATOR PARAMETER_AND_RESULT_PROFILE
99 -- PARAMETER_PROFILE ::= [FORMAL_PART]
101 -- PARAMETER_AND_RESULT_PROFILE ::= [FORMAL_PART] return SUBTYPE_MARK
103 -- SUBPROGRAM_BODY ::=
104 -- SUBPROGRAM_SPECIFICATION is
107 -- HANDLED_SEQUENCE_OF_STATEMENTS
110 -- SUBPROGRAM_RENAMING_DECLARATION ::=
111 -- SUBPROGRAM_SPECIFICATION renames callable_entity_NAME;
113 -- SUBPROGRAM_BODY_STUB ::=
114 -- SUBPROGRAM_SPECIFICATION is separate;
116 -- GENERIC_INSTANTIATION ::=
117 -- procedure DEFINING_PROGRAM_UNIT_NAME is
118 -- new generic_procedure_NAME [GENERIC_ACTUAL_PART];
119 -- | function DEFINING_DESIGNATOR is
120 -- new generic_function_NAME [GENERIC_ACTUAL_PART];
122 -- NULL_PROCEDURE_DECLARATION ::=
123 -- SUBPROGRAM_SPECIFICATION is null;
125 -- Null procedures are an Ada 2005 feature. A null procedure declaration
126 -- is classified as a basic declarative item, but it is parsed here, with
127 -- other subprogram constructs.
129 -- PARAMETERIZED_EXPRESSION ::=
130 -- FUNCTION SPECIFICATION IS (EXPRESSION);
132 -- The value in Pf_Flags indicates which of these possible declarations
133 -- is acceptable to the caller:
135 -- Pf_Flags.Decl Set if declaration OK
136 -- Pf_Flags.Gins Set if generic instantiation OK
137 -- Pf_Flags.Pbod Set if proper body OK
138 -- Pf_Flags.Rnam Set if renaming declaration OK
139 -- Pf_Flags.Stub Set if body stub OK
140 -- Pf_Flags.Pexp Set if parameterized expression OK
142 -- If an inappropriate form is encountered, it is scanned out but an
143 -- error message indicating that it is appearing in an inappropriate
144 -- context is issued. The only possible values for Pf_Flags are those
145 -- defined as constants in the Par package.
147 -- The caller has checked that the initial token is FUNCTION, PROCEDURE,
148 -- NOT or OVERRIDING.
150 -- Error recovery: cannot raise Error_Resync
152 function P_Subprogram
(Pf_Flags
: Pf_Rec
) return Node_Id
is
153 Specification_Node
: Node_Id
;
155 Fpart_List
: List_Id
;
156 Fpart_Sloc
: Source_Ptr
;
157 Result_Not_Null
: Boolean := False;
158 Result_Node
: Node_Id
;
162 Rename_Node
: Node_Id
;
163 Absdec_Node
: Node_Id
;
165 Fproc_Sloc
: Source_Ptr
;
167 Scan_State
: Saved_Scan_State
;
169 -- Flags for optional overriding indication. Two flags are needed,
170 -- to distinguish positive and negative overriding indicators from
171 -- the absence of any indicator.
173 Is_Overriding
: Boolean := False;
174 Not_Overriding
: Boolean := False;
177 -- Set up scope stack entry. Note that the Labl field will be set later
179 SIS_Entry_Active
:= False;
180 SIS_Missing_Semicolon_Message
:= No_Error_Msg
;
182 Scope
.Table
(Scope
.Last
).Sloc
:= Token_Ptr
;
183 Scope
.Table
(Scope
.Last
).Etyp
:= E_Name
;
184 Scope
.Table
(Scope
.Last
).Ecol
:= Start_Column
;
185 Scope
.Table
(Scope
.Last
).Lreq
:= False;
187 -- Ada2005: scan leading NOT OVERRIDING indicator
189 if Token
= Tok_Not
then
192 if Token
= Tok_Overriding
then
193 Scan
; -- past OVERRIDING
194 Not_Overriding
:= True;
196 -- Overriding keyword used in non Ada 2005 mode
198 elsif Token
= Tok_Identifier
199 and then Token_Name
= Name_Overriding
201 Error_Msg_SC
("overriding indicator is an Ada 2005 extension");
202 Error_Msg_SC
("\unit must be compiled with -gnat05 switch");
203 Scan
; -- past Overriding
204 Not_Overriding
:= True;
207 Error_Msg_SC
-- CODEFIX
208 ("OVERRIDING expected!");
211 -- Ada 2005: scan leading OVERRIDING indicator
213 -- Note: in the case of OVERRIDING keyword used in Ada 95 mode, the
214 -- declaration circuit already gave an error message and changed the
215 -- token to Tok_Overriding.
217 elsif Token
= Tok_Overriding
then
218 Scan
; -- past OVERRIDING
219 Is_Overriding
:= True;
222 if Is_Overriding
or else Not_Overriding
then
224 -- Note that if we are not in Ada_2005 mode, error messages have
225 -- already been given, so no need to give another message here.
227 -- An overriding indicator is allowed for subprogram declarations,
228 -- bodies (including subunits), renamings, stubs, and instantiations.
229 -- The test against Pf_Decl_Pbod is added to account for the case of
230 -- subprograms declared in a protected type, where only subprogram
231 -- declarations and bodies can occur. The Pf_Pbod case is for
234 if Pf_Flags
/= Pf_Decl_Gins_Pbod_Rnam_Stub_Pexp
236 Pf_Flags
/= Pf_Decl_Pbod_Pexp
238 Pf_Flags
/= Pf_Pbod_Pexp
240 Error_Msg_SC
("overriding indicator not allowed here!");
242 elsif Token
/= Tok_Function
and then Token
/= Tok_Procedure
then
243 Error_Msg_SC
-- CODEFIX
244 ("FUNCTION or PROCEDURE expected!");
248 Func
:= (Token
= Tok_Function
);
249 Fproc_Sloc
:= Token_Ptr
;
250 Scan
; -- past FUNCTION or PROCEDURE
255 Name_Node
:= P_Defining_Designator
;
257 if Nkind
(Name_Node
) = N_Defining_Operator_Symbol
258 and then Scope
.Last
= 1
260 Error_Msg_SP
("operator symbol not allowed at library level");
261 Name_Node
:= New_Entity
(N_Defining_Identifier
, Sloc
(Name_Node
));
263 -- Set name from file name, we need some junk name, and that's
264 -- as good as anything. This is only approximate, since we do
265 -- not do anything with non-standard name translations.
267 Get_Name_String
(File_Name
(Current_Source_File
));
269 for J
in 1 .. Name_Len
loop
270 if Name_Buffer
(J
) = '.' then
276 Set_Chars
(Name_Node
, Name_Find
);
277 Set_Error_Posted
(Name_Node
);
281 Name_Node
:= P_Defining_Program_Unit_Name
;
284 Scope
.Table
(Scope
.Last
).Labl
:= Name_Node
;
287 -- Deal with generic instantiation, the one case in which we do not
288 -- have a subprogram specification as part of whatever we are parsing
290 if Token
= Tok_Is
then
291 Save_Scan_State
(Scan_State
); -- at the IS
292 T_Is
; -- checks for redundant IS
294 if Token
= Tok_New
then
295 if not Pf_Flags
.Gins
then
296 Error_Msg_SC
("generic instantiation not allowed here!");
302 Inst_Node
:= New_Node
(N_Function_Instantiation
, Fproc_Sloc
);
303 Set_Name
(Inst_Node
, P_Function_Name
);
305 Inst_Node
:= New_Node
(N_Procedure_Instantiation
, Fproc_Sloc
);
306 Set_Name
(Inst_Node
, P_Qualified_Simple_Name
);
309 Set_Defining_Unit_Name
(Inst_Node
, Name_Node
);
310 Set_Generic_Associations
(Inst_Node
, P_Generic_Actual_Part_Opt
);
311 P_Aspect_Specifications
(Inst_Node
);
312 Pop_Scope_Stack
; -- Don't need scope stack entry in this case
314 if Is_Overriding
then
315 Set_Must_Override
(Inst_Node
);
317 elsif Not_Overriding
then
318 Set_Must_Not_Override
(Inst_Node
);
324 Restore_Scan_State
(Scan_State
); -- to the IS
328 -- If not a generic instantiation, then we definitely have a subprogram
329 -- specification (all possibilities at this stage include one here)
331 Fpart_Sloc
:= Token_Ptr
;
333 Check_Misspelling_Of
(Tok_Return
);
335 -- Scan formal part. First a special error check. If we have an
336 -- identifier here, then we have a definite error. If this identifier
337 -- is on the same line as the designator, then we assume it is the
338 -- first formal after a missing left parenthesis
340 if Token
= Tok_Identifier
341 and then not Token_Is_At_Start_Of_Line
343 T_Left_Paren
; -- to generate message
344 Fpart_List
:= P_Formal_Part
;
346 -- Otherwise scan out an optional formal part in the usual manner
349 Fpart_List
:= P_Parameter_Profile
;
352 -- We treat what we have as a function specification if FUNCTION was
353 -- used, or if a RETURN is present. This gives better error recovery
354 -- since later RETURN statements will be valid in either case.
356 Check_Junk_Semicolon_Before_Return
;
357 Result_Node
:= Error
;
359 if Token
= Tok_Return
then
362 ("PROCEDURE should be FUNCTION", Fproc_Sloc
);
368 Result_Not_Null
:= P_Null_Exclusion
; -- Ada 2005 (AI-231)
370 -- Ada 2005 (AI-318-02)
372 if Token
= Tok_Access
then
373 if Ada_Version
< Ada_2005
then
375 ("anonymous access result type is an Ada 2005 extension");
376 Error_Msg_SC
("\unit must be compiled with -gnat05 switch");
379 Result_Node
:= P_Access_Definition
(Result_Not_Null
);
382 Result_Node
:= P_Subtype_Mark
;
387 -- Skip extra parenthesis at end of formal part
389 Ignore
(Tok_Right_Paren
);
391 -- For function, scan result subtype
396 if Prev_Token
= Tok_Return
then
397 Result_Node
:= P_Subtype_Mark
;
403 Specification_Node
:=
404 New_Node
(N_Function_Specification
, Fproc_Sloc
);
406 Set_Null_Exclusion_Present
(Specification_Node
, Result_Not_Null
);
407 Set_Result_Definition
(Specification_Node
, Result_Node
);
410 Specification_Node
:=
411 New_Node
(N_Procedure_Specification
, Fproc_Sloc
);
414 Set_Defining_Unit_Name
(Specification_Node
, Name_Node
);
415 Set_Parameter_Specifications
(Specification_Node
, Fpart_List
);
417 if Is_Overriding
then
418 Set_Must_Override
(Specification_Node
);
420 elsif Not_Overriding
then
421 Set_Must_Not_Override
(Specification_Node
);
424 -- Error check: barriers not allowed on protected functions/procedures
426 if Token
= Tok_When
then
428 Error_Msg_SC
("barrier not allowed on function, only on entry");
430 Error_Msg_SC
("barrier not allowed on procedure, only on entry");
434 Discard_Junk_Node
(P_Expression
);
437 -- Deal with semicolon followed by IS. We want to treat this as IS
439 if Token
= Tok_Semicolon
then
440 Save_Scan_State
(Scan_State
);
441 Scan
; -- past semicolon
443 if Token
= Tok_Is
then
444 Error_Msg_SP
-- CODEFIX
445 ("extra "";"" ignored");
447 Restore_Scan_State
(Scan_State
);
451 -- Subprogram declaration ended by aspect specifications
453 if Aspect_Specifications_Present
then
454 goto Subprogram_Declaration
;
456 -- Deal with case of semicolon ending a subprogram declaration
458 elsif Token
= Tok_Semicolon
then
459 if not Pf_Flags
.Decl
then
463 Save_Scan_State
(Scan_State
);
464 Scan
; -- past semicolon
466 -- If semicolon is immediately followed by IS, then ignore the
467 -- semicolon, and go process the body.
469 if Token
= Tok_Is
then
470 Error_Msg_SP
-- CODEFIX
471 ("|extra "";"" ignored");
472 T_Is
; -- scan past IS
473 goto Subprogram_Body
;
475 -- If BEGIN follows in an appropriate column, we immediately
476 -- commence the error action of assuming that the previous
477 -- subprogram declaration should have been a subprogram body,
478 -- i.e. that the terminating semicolon should have been IS.
480 elsif Token
= Tok_Begin
481 and then Start_Column
>= Scope
.Table
(Scope
.Last
).Ecol
483 Error_Msg_SP
-- CODEFIX
484 ("|"";"" should be IS!");
485 goto Subprogram_Body
;
488 Restore_Scan_State
(Scan_State
);
489 goto Subprogram_Declaration
;
492 -- Case of not followed by semicolon
495 -- Subprogram renaming declaration case
497 Check_Misspelling_Of
(Tok_Renames
);
499 if Token
= Tok_Renames
then
500 if not Pf_Flags
.Rnam
then
501 Error_Msg_SC
("renaming declaration not allowed here!");
505 New_Node
(N_Subprogram_Renaming_Declaration
, Token_Ptr
);
506 Scan
; -- past RENAMES
507 Set_Name
(Rename_Node
, P_Name
);
508 Set_Specification
(Rename_Node
, Specification_Node
);
513 -- Case of IS following subprogram specification
515 elsif Token
= Tok_Is
then
516 T_Is
; -- ignore redundant Is's
518 if Token_Name
= Name_Abstract
then
519 Check_95_Keyword
(Tok_Abstract
, Tok_Semicolon
);
522 -- Deal nicely with (now obsolete) use of <> in place of abstract
524 if Token
= Tok_Box
then
525 Error_Msg_SC
-- CODEFIX
526 ("ABSTRACT expected");
527 Token
:= Tok_Abstract
;
530 -- Abstract subprogram declaration case
532 if Token
= Tok_Abstract
then
534 New_Node
(N_Abstract_Subprogram_Declaration
, Token_Ptr
);
535 Set_Specification
(Absdec_Node
, Specification_Node
);
536 Pop_Scope_Stack
; -- discard unneeded entry
537 Scan
; -- past ABSTRACT
538 P_Aspect_Specifications
(Absdec_Node
);
541 -- Ada 2005 (AI-248): Parse a null procedure declaration
543 elsif Token
= Tok_Null
then
544 if Ada_Version
< Ada_2005
then
545 Error_Msg_SP
("null procedures are an Ada 2005 extension");
546 Error_Msg_SP
("\unit must be compiled with -gnat05 switch");
552 Error_Msg_SP
("only procedures can be null");
554 Set_Null_Present
(Specification_Node
);
557 goto Subprogram_Declaration
;
559 -- Check for IS NEW with Formal_Part present and handle nicely
561 elsif Token
= Tok_New
then
563 ("formal part not allowed in instantiation", Fpart_Sloc
);
567 Inst_Node
:= New_Node
(N_Function_Instantiation
, Fproc_Sloc
);
570 New_Node
(N_Procedure_Instantiation
, Fproc_Sloc
);
573 Set_Defining_Unit_Name
(Inst_Node
, Name_Node
);
574 Set_Name
(Inst_Node
, P_Name
);
575 Set_Generic_Associations
(Inst_Node
, P_Generic_Actual_Part_Opt
);
577 Pop_Scope_Stack
; -- Don't need scope stack entry in this case
581 goto Subprogram_Body
;
584 -- Aspect specifications present
586 elsif Aspect_Specifications_Present
then
587 goto Subprogram_Declaration
;
589 -- Here we have a missing IS or missing semicolon, we always guess
590 -- a missing semicolon, since we are pretty good at fixing up a
591 -- semicolon which should really be an IS
594 Error_Msg_AP
-- CODEFIX
596 SIS_Missing_Semicolon_Message
:= Get_Msg_Id
;
597 goto Subprogram_Declaration
;
601 -- Processing for stub or subprogram body or parameterized expression
605 -- Subprogram body stub case
607 if Separate_Present
then
608 if not Pf_Flags
.Stub
then
609 Error_Msg_SC
("body stub not allowed here!");
612 if Nkind
(Name_Node
) = N_Defining_Operator_Symbol
then
614 ("operator symbol cannot be used as subunit name",
619 New_Node
(N_Subprogram_Body_Stub
, Sloc
(Specification_Node
));
620 Set_Specification
(Stub_Node
, Specification_Node
);
621 Scan
; -- past SEPARATE
626 -- Subprogram body or parameterized expression case
629 Scan_Body_Or_Parameterized_Expression
: declare
631 function Likely_Parameterized_Expression
return Boolean;
632 -- Returns True if we have a probably case of a parameterized
633 -- expression omitting the parentheses, if so, returns True
634 -- and emits an appropriate error message, else returns False.
636 -------------------------------------
637 -- Likely_Parameterized_Expression --
638 -------------------------------------
640 function Likely_Parameterized_Expression
return Boolean is
642 -- If currently pointing to BEGIN or a declaration keyword
643 -- or a pragma, then we definitely have a subprogram body.
644 -- This is a common case, so worth testing first.
647 or else Token
in Token_Class_Declk
648 or else Token
= Tok_Pragma
652 -- Test for tokens which could only start an expression and
653 -- thus signal the case of a parameterized expression.
655 elsif Token
in Token_Class_Literal
656 or else Token
in Token_Class_Unary_Addop
657 or else Token
= Tok_Left_Paren
658 or else Token
= Tok_Abs
659 or else Token
= Tok_Null
660 or else Token
= Tok_New
661 or else Token
= Tok_Not
665 -- Anything other than an identifier must be a body
667 elsif Token
/= Tok_Identifier
then
670 -- Here for an identifier
673 -- If the identifier is the first token on its line, then
674 -- let's assume that we have a missing begin and this is
675 -- intended as a subprogram body.
677 if Token_Is_At_Start_Of_Line
then
680 -- Otherwise we have to scan ahead. If the identifier is
681 -- followed by a colon or a comma, it is a declaration
682 -- and hence we have a subprogram body. Otherwise assume
683 -- a parameterized expression.
687 Scan_State
: Saved_Scan_State
;
690 Save_Scan_State
(Scan_State
);
691 Scan
; -- past identifier
693 Restore_Scan_State
(Scan_State
);
695 if Tok
= Tok_Colon
or else Tok
= Tok_Comma
then
702 -- Fall through if we have a likely parameterized expression
705 ("parameterized expression must be "
706 & "enclosed in parentheses");
708 end Likely_Parameterized_Expression
;
710 -- Start of processing for Scan_Body_Or_Parameterized_Expression
713 -- Parameterized_Expression case
715 if Token
= Tok_Left_Paren
716 or else Likely_Parameterized_Expression
718 -- Check parameterized expression allowed here
720 if not Pf_Flags
.Pexp
then
722 ("parameterized expression not allowed here!");
725 -- Check we are in Ada 2012 mode
727 if Ada_Version
< Ada_2012
then
729 ("parameterized expression is an Ada 2012 feature!");
731 ("\unit must be compiled with -gnat2012 switch!");
734 -- Parse out expression and build parameterized expression
738 (N_Parameterized_Expression
, Sloc
(Specification_Node
));
739 Set_Specification
(Body_Node
, Specification_Node
);
740 Set_Expression
(Body_Node
, P_Expression
);
744 -- Subprogram body case
747 -- Check body allowed here
749 if not Pf_Flags
.Pbod
then
750 Error_Msg_SP
("subprogram body not allowed here!");
753 -- Here is the test for a suspicious IS (i.e. one that
754 -- looks like it might more properly be a semicolon).
755 -- See separate section describing use of IS instead
756 -- of semicolon in package Parse.
758 if (Token
in Token_Class_Declk
760 Token
= Tok_Identifier
)
761 and then Start_Column
<= Scope
.Table
(Scope
.Last
).Ecol
762 and then Scope
.Last
/= 1
764 Scope
.Table
(Scope
.Last
).Etyp
:= E_Suspicious_Is
;
765 Scope
.Table
(Scope
.Last
).S_Is
:= Prev_Token_Ptr
;
768 -- Build and return subprogram body, parsing declarations
769 -- and statement sequence that belong to the body.
772 New_Node
(N_Subprogram_Body
, Sloc
(Specification_Node
));
773 Set_Specification
(Body_Node
, Specification_Node
);
774 Parse_Decls_Begin_End
(Body_Node
);
778 end Scan_Body_Or_Parameterized_Expression
;
781 -- Processing for subprogram declaration
783 <<Subprogram_Declaration
>>
785 New_Node
(N_Subprogram_Declaration
, Sloc
(Specification_Node
));
786 Set_Specification
(Decl_Node
, Specification_Node
);
787 P_Aspect_Specifications
(Decl_Node
);
789 -- If this is a context in which a subprogram body is permitted,
790 -- set active SIS entry in case (see section titled "Handling
791 -- Semicolon Used in Place of IS" in body of Parser package)
792 -- Note that SIS_Missing_Semicolon_Message is already set properly.
794 if Pf_Flags
.Pbod
then
795 SIS_Labl
:= Scope
.Table
(Scope
.Last
).Labl
;
796 SIS_Sloc
:= Scope
.Table
(Scope
.Last
).Sloc
;
797 SIS_Ecol
:= Scope
.Table
(Scope
.Last
).Ecol
;
798 SIS_Declaration_Node
:= Decl_Node
;
799 SIS_Semicolon_Sloc
:= Prev_Token_Ptr
;
800 SIS_Entry_Active
:= True;
807 ---------------------------------
808 -- 6.1 Subprogram Declaration --
809 ---------------------------------
811 -- Parsed by P_Subprogram (6.1)
813 ------------------------------------------
814 -- 6.1 Abstract Subprogram Declaration --
815 ------------------------------------------
817 -- Parsed by P_Subprogram (6.1)
819 -----------------------------------
820 -- 6.1 Subprogram Specification --
821 -----------------------------------
823 -- SUBPROGRAM_SPECIFICATION ::=
824 -- procedure DEFINING_PROGRAM_UNIT_NAME PARAMETER_PROFILE
825 -- | function DEFINING_DESIGNATOR PARAMETER_AND_RESULT_PROFILE
827 -- PARAMETER_PROFILE ::= [FORMAL_PART]
829 -- PARAMETER_AND_RESULT_PROFILE ::= [FORMAL_PART] return SUBTYPE_MARK
831 -- Subprogram specifications that appear in subprogram declarations
832 -- are parsed by P_Subprogram (6.1). This routine is used in other
833 -- contexts where subprogram specifications occur.
835 -- Note: this routine does not affect the scope stack in any way
837 -- Error recovery: can raise Error_Resync
839 function P_Subprogram_Specification
return Node_Id
is
840 Specification_Node
: Node_Id
;
841 Result_Not_Null
: Boolean;
842 Result_Node
: Node_Id
;
845 if Token
= Tok_Function
then
846 Specification_Node
:= New_Node
(N_Function_Specification
, Token_Ptr
);
847 Scan
; -- past FUNCTION
849 Set_Defining_Unit_Name
(Specification_Node
, P_Defining_Designator
);
850 Set_Parameter_Specifications
851 (Specification_Node
, P_Parameter_Profile
);
852 Check_Junk_Semicolon_Before_Return
;
855 Result_Not_Null
:= P_Null_Exclusion
; -- Ada 2005 (AI-231)
857 -- Ada 2005 (AI-318-02)
859 if Token
= Tok_Access
then
860 if Ada_Version
< Ada_2005
then
862 ("anonymous access result type is an Ada 2005 extension");
863 Error_Msg_SC
("\unit must be compiled with -gnat05 switch");
866 Result_Node
:= P_Access_Definition
(Result_Not_Null
);
869 Result_Node
:= P_Subtype_Mark
;
873 Set_Null_Exclusion_Present
(Specification_Node
, Result_Not_Null
);
874 Set_Result_Definition
(Specification_Node
, Result_Node
);
875 return Specification_Node
;
877 elsif Token
= Tok_Procedure
then
878 Specification_Node
:= New_Node
(N_Procedure_Specification
, Token_Ptr
);
879 Scan
; -- past PROCEDURE
881 Set_Defining_Unit_Name
882 (Specification_Node
, P_Defining_Program_Unit_Name
);
883 Set_Parameter_Specifications
884 (Specification_Node
, P_Parameter_Profile
);
885 return Specification_Node
;
888 Error_Msg_SC
("subprogram specification expected");
891 end P_Subprogram_Specification
;
893 ---------------------
895 ---------------------
898 -- [PARENT_UNIT_NAME .] IDENTIFIER | OPERATOR_SYMBOL
900 -- The caller has checked that the initial token is an identifier,
901 -- operator symbol, or string literal. Note that we don't bother to
902 -- do much error diagnosis in this routine, since it is only used for
903 -- the label on END lines, and the routines in package Par.Endh will
904 -- check that the label is appropriate.
906 -- Error recovery: cannot raise Error_Resync
908 function P_Designator
return Node_Id
is
909 Ident_Node
: Node_Id
;
911 Prefix_Node
: Node_Id
;
913 function Real_Dot
return Boolean;
914 -- Tests if a current token is an interesting period, i.e. is followed
915 -- by an identifier or operator symbol or string literal. If not, it is
916 -- probably just incorrect punctuation to be caught by our caller. Note
917 -- that the case of an operator symbol or string literal is also an
918 -- error, but that is an error that we catch here. If the result is
919 -- True, a real dot has been scanned and we are positioned past it,
920 -- if the result is False, the scan position is unchanged.
926 function Real_Dot
return Boolean is
927 Scan_State
: Saved_Scan_State
;
930 if Token
/= Tok_Dot
then
934 Save_Scan_State
(Scan_State
);
937 if Token
= Tok_Identifier
938 or else Token
= Tok_Operator_Symbol
939 or else Token
= Tok_String_Literal
944 Restore_Scan_State
(Scan_State
);
950 -- Start of processing for P_Designator
953 Ident_Node
:= Token_Node
;
954 Scan
; -- past initial token
956 if Prev_Token
= Tok_Operator_Symbol
957 or else Prev_Token
= Tok_String_Literal
965 Prefix_Node
:= Ident_Node
;
967 -- Loop through child names, on entry to this loop, Prefix contains
968 -- the name scanned so far, and Ident_Node is the last identifier.
971 Name_Node
:= New_Node
(N_Selected_Component
, Prev_Token_Ptr
);
972 Set_Prefix
(Name_Node
, Prefix_Node
);
973 Ident_Node
:= P_Identifier
;
974 Set_Selector_Name
(Name_Node
, Ident_Node
);
975 Prefix_Node
:= Name_Node
;
976 exit when not Real_Dot
;
979 -- On exit from the loop, Ident_Node is the last identifier scanned,
980 -- i.e. the defining identifier, and Prefix_Node is a node for the
981 -- entire name, structured (incorrectly!) as a selected component.
983 Name_Node
:= Prefix
(Prefix_Node
);
984 Change_Node
(Prefix_Node
, N_Designator
);
985 Set_Name
(Prefix_Node
, Name_Node
);
986 Set_Identifier
(Prefix_Node
, Ident_Node
);
992 while Token
= Tok_Dot
or else Token
= Tok_Identifier
loop
999 ------------------------------
1000 -- 6.1 Defining Designator --
1001 ------------------------------
1003 -- DEFINING_DESIGNATOR ::=
1004 -- DEFINING_PROGRAM_UNIT_NAME | DEFINING_OPERATOR_SYMBOL
1006 -- Error recovery: cannot raise Error_Resync
1008 function P_Defining_Designator
return Node_Id
is
1010 if Token
= Tok_Operator_Symbol
then
1011 return P_Defining_Operator_Symbol
;
1013 elsif Token
= Tok_String_Literal
then
1014 Error_Msg_SC
("invalid operator name");
1015 Scan
; -- past junk string
1019 return P_Defining_Program_Unit_Name
;
1021 end P_Defining_Designator
;
1023 -------------------------------------
1024 -- 6.1 Defining Program Unit Name --
1025 -------------------------------------
1027 -- DEFINING_PROGRAM_UNIT_NAME ::=
1028 -- [PARENT_UNIT_NAME .] DEFINING_IDENTIFIER
1030 -- Note: PARENT_UNIT_NAME may be present only in 95 mode at the outer level
1032 -- Error recovery: cannot raise Error_Resync
1034 function P_Defining_Program_Unit_Name
return Node_Id
is
1035 Ident_Node
: Node_Id
;
1036 Name_Node
: Node_Id
;
1037 Prefix_Node
: Node_Id
;
1040 -- Set identifier casing if not already set and scan initial identifier
1042 if Token
= Tok_Identifier
1043 and then Identifier_Casing
(Current_Source_File
) = Unknown
1045 Set_Identifier_Casing
(Current_Source_File
, Determine_Token_Casing
);
1048 Ident_Node
:= P_Identifier
(C_Dot
);
1049 Merge_Identifier
(Ident_Node
, Tok_Return
);
1051 -- Normal case (not child library unit name)
1053 if Token
/= Tok_Dot
then
1054 Change_Identifier_To_Defining_Identifier
(Ident_Node
);
1057 -- Child library unit name case
1060 if Scope
.Last
> 1 then
1061 Error_Msg_SP
("child unit allowed only at library level");
1064 elsif Ada_Version
= Ada_83
then
1065 Error_Msg_SP
("(Ada 83) child unit not allowed!");
1069 Prefix_Node
:= Ident_Node
;
1071 -- Loop through child names, on entry to this loop, Prefix contains
1072 -- the name scanned so far, and Ident_Node is the last identifier.
1075 exit when Token
/= Tok_Dot
;
1076 Name_Node
:= New_Node
(N_Selected_Component
, Token_Ptr
);
1077 Scan
; -- past period
1078 Set_Prefix
(Name_Node
, Prefix_Node
);
1079 Ident_Node
:= P_Identifier
(C_Dot
);
1080 Set_Selector_Name
(Name_Node
, Ident_Node
);
1081 Prefix_Node
:= Name_Node
;
1084 -- On exit from the loop, Ident_Node is the last identifier scanned,
1085 -- i.e. the defining identifier, and Prefix_Node is a node for the
1086 -- entire name, structured (incorrectly!) as a selected component.
1088 Name_Node
:= Prefix
(Prefix_Node
);
1089 Change_Node
(Prefix_Node
, N_Defining_Program_Unit_Name
);
1090 Set_Name
(Prefix_Node
, Name_Node
);
1091 Change_Identifier_To_Defining_Identifier
(Ident_Node
);
1092 Set_Defining_Identifier
(Prefix_Node
, Ident_Node
);
1094 -- All set with unit name parsed
1100 when Error_Resync
=>
1101 while Token
= Tok_Dot
or else Token
= Tok_Identifier
loop
1106 end P_Defining_Program_Unit_Name
;
1108 --------------------------
1109 -- 6.1 Operator Symbol --
1110 --------------------------
1112 -- OPERATOR_SYMBOL ::= STRING_LITERAL
1114 -- Operator symbol is returned by the scanner as Tok_Operator_Symbol
1116 -----------------------------------
1117 -- 6.1 Defining Operator Symbol --
1118 -----------------------------------
1120 -- DEFINING_OPERATOR_SYMBOL ::= OPERATOR_SYMBOL
1122 -- The caller has checked that the initial symbol is an operator symbol
1124 function P_Defining_Operator_Symbol
return Node_Id
is
1128 Op_Node
:= Token_Node
;
1129 Change_Operator_Symbol_To_Defining_Operator_Symbol
(Op_Node
);
1130 Scan
; -- past operator symbol
1132 end P_Defining_Operator_Symbol
;
1134 ----------------------------
1135 -- 6.1 Parameter_Profile --
1136 ----------------------------
1138 -- PARAMETER_PROFILE ::= [FORMAL_PART]
1140 -- Empty is returned if no formal part is present
1142 -- Error recovery: cannot raise Error_Resync
1144 function P_Parameter_Profile
return List_Id
is
1146 if Token
= Tok_Left_Paren
then
1147 Scan
; -- part left paren
1148 return P_Formal_Part
;
1152 end P_Parameter_Profile
;
1154 ---------------------------------------
1155 -- 6.1 Parameter And Result Profile --
1156 ---------------------------------------
1158 -- Parsed by its parent construct, which uses P_Parameter_Profile to
1159 -- parse the parameters, and P_Subtype_Mark to parse the return type.
1161 ----------------------
1162 -- 6.1 Formal part --
1163 ----------------------
1165 -- FORMAL_PART ::= (PARAMETER_SPECIFICATION {; PARAMETER_SPECIFICATION})
1167 -- PARAMETER_SPECIFICATION ::=
1168 -- DEFINING_IDENTIFIER_LIST : MODE [NULL_EXCLUSION] SUBTYPE_MARK
1169 -- [:= DEFAULT_EXPRESSION]
1170 -- | DEFINING_IDENTIFIER_LIST : ACCESS_DEFINITION
1171 -- [:= DEFAULT_EXPRESSION]
1173 -- This scans the construct Formal_Part. The caller has already checked
1174 -- that the initial token is a left parenthesis, and skipped past it, so
1175 -- that on entry Token is the first token following the left parenthesis.
1177 -- Error recovery: cannot raise Error_Resync
1179 function P_Formal_Part
return List_Id
is
1180 Specification_List
: List_Id
;
1181 Specification_Node
: Node_Id
;
1182 Scan_State
: Saved_Scan_State
;
1185 Ident_Sloc
: Source_Ptr
;
1186 Not_Null_Present
: Boolean := False;
1187 Not_Null_Sloc
: Source_Ptr
;
1189 Idents
: array (Int
range 1 .. 4096) of Entity_Id
;
1190 -- This array holds the list of defining identifiers. The upper bound
1191 -- of 4096 is intended to be essentially infinite, and we do not even
1192 -- bother to check for it being exceeded.
1195 Specification_List
:= New_List
;
1196 Specification_Loop
: loop
1198 if Token
= Tok_Pragma
then
1199 Error_Msg_SC
("pragma not allowed in formal part");
1200 Discard_Junk_Node
(P_Pragma
(Skipping
=> True));
1203 Ignore
(Tok_Left_Paren
);
1204 Ident_Sloc
:= Token_Ptr
;
1205 Idents
(1) := P_Defining_Identifier
(C_Comma_Colon
);
1209 exit Ident_Loop
when Token
= Tok_Colon
;
1211 -- The only valid tokens are colon and comma, so if we have
1212 -- neither do a bit of investigation to see which is the
1213 -- better choice for insertion.
1215 if Token
/= Tok_Comma
then
1217 -- Assume colon if IN or OUT keyword found
1219 exit Ident_Loop
when Token
= Tok_In
or else Token
= Tok_Out
;
1221 -- Otherwise scan ahead
1223 Save_Scan_State
(Scan_State
);
1226 -- If we run into a semicolon, then assume that a
1227 -- colon was missing, e.g. Parms (X Y; ...). Also
1228 -- assume missing colon on EOF (a real disaster!)
1229 -- and on a right paren, e.g. Parms (X Y), and also
1230 -- on an assignment symbol, e.g. Parms (X Y := ..)
1232 if Token
= Tok_Semicolon
1233 or else Token
= Tok_Right_Paren
1234 or else Token
= Tok_EOF
1235 or else Token
= Tok_Colon_Equal
1237 Restore_Scan_State
(Scan_State
);
1240 -- If we run into a colon, assume that we had a missing
1241 -- comma, e.g. Parms (A B : ...). Also assume a missing
1242 -- comma if we hit another comma, e.g. Parms (A B, C ..)
1244 elsif Token
= Tok_Colon
1245 or else Token
= Tok_Comma
1247 Restore_Scan_State
(Scan_State
);
1252 end loop Look_Ahead
;
1255 -- Here if a comma is present, or to be assumed
1258 Num_Idents
:= Num_Idents
+ 1;
1259 Idents
(Num_Idents
) := P_Defining_Identifier
(C_Comma_Colon
);
1260 end loop Ident_Loop
;
1262 -- Fall through the loop on encountering a colon, or deciding
1263 -- that there is a missing colon.
1267 -- If there are multiple identifiers, we repeatedly scan the
1268 -- type and initialization expression information by resetting
1269 -- the scan pointer (so that we get completely separate trees
1270 -- for each occurrence).
1272 if Num_Idents
> 1 then
1273 Save_Scan_State
(Scan_State
);
1276 -- Loop through defining identifiers in list
1280 Ident_List_Loop
: loop
1281 Specification_Node
:=
1282 New_Node
(N_Parameter_Specification
, Ident_Sloc
);
1283 Set_Defining_Identifier
(Specification_Node
, Idents
(Ident
));
1285 -- Scan possible NOT NULL for Ada 2005 (AI-231, AI-447)
1287 Not_Null_Sloc
:= Token_Ptr
;
1289 P_Null_Exclusion
(Allow_Anonymous_In_95
=> True);
1291 -- Case of ACCESS keyword present
1293 if Token
= Tok_Access
then
1294 Set_Null_Exclusion_Present
1295 (Specification_Node
, Not_Null_Present
);
1297 if Ada_Version
= Ada_83
then
1298 Error_Msg_SC
("(Ada 83) access parameters not allowed");
1302 (Specification_Node
,
1303 P_Access_Definition
(Not_Null_Present
));
1305 -- Case of IN or OUT present
1308 if Token
= Tok_In
or else Token
= Tok_Out
then
1309 if Not_Null_Present
then
1311 ("`NOT NULL` can only be used with `ACCESS`",
1314 if Token
= Tok_In
then
1316 ("\`IN` not allowed together with `ACCESS`",
1320 ("\`OUT` not allowed together with `ACCESS`",
1325 P_Mode
(Specification_Node
);
1326 Not_Null_Present
:= P_Null_Exclusion
; -- Ada 2005 (AI-231)
1329 Set_Null_Exclusion_Present
1330 (Specification_Node
, Not_Null_Present
);
1332 if Token
= Tok_Procedure
1334 Token
= Tok_Function
1336 Error_Msg_SC
("formal subprogram parameter not allowed");
1339 if Token
= Tok_Left_Paren
then
1340 Discard_Junk_List
(P_Formal_Part
);
1343 if Token
= Tok_Return
then
1345 Discard_Junk_Node
(P_Subtype_Mark
);
1348 Set_Parameter_Type
(Specification_Node
, Error
);
1351 Set_Parameter_Type
(Specification_Node
, P_Subtype_Mark
);
1356 Set_Expression
(Specification_Node
, Init_Expr_Opt
(True));
1359 Set_Prev_Ids
(Specification_Node
, True);
1362 if Ident
< Num_Idents
then
1363 Set_More_Ids
(Specification_Node
, True);
1366 Append
(Specification_Node
, Specification_List
);
1367 exit Ident_List_Loop
when Ident
= Num_Idents
;
1369 Restore_Scan_State
(Scan_State
);
1370 end loop Ident_List_Loop
;
1373 when Error_Resync
=>
1374 Resync_Semicolon_List
;
1377 if Token
= Tok_Semicolon
then
1378 Save_Scan_State
(Scan_State
);
1379 Scan
; -- past semicolon
1381 -- If we have RETURN or IS after the semicolon, then assume
1382 -- that semicolon should have been a right parenthesis and exit
1384 if Token
= Tok_Is
or else Token
= Tok_Return
then
1385 Error_Msg_SP
-- CODEFIX
1386 ("|"";"" should be "")""");
1387 exit Specification_Loop
;
1390 -- If we have a declaration keyword after the semicolon, then
1391 -- assume we had a missing right parenthesis and terminate list
1393 if Token
in Token_Class_Declk
then
1394 Error_Msg_AP
-- CODEFIX
1396 Restore_Scan_State
(Scan_State
);
1397 exit Specification_Loop
;
1400 elsif Token
= Tok_Right_Paren
then
1401 Scan
; -- past right paren
1402 exit Specification_Loop
;
1404 -- Special check for common error of using comma instead of semicolon
1406 elsif Token
= Tok_Comma
then
1410 -- Special check for omitted separator
1412 elsif Token
= Tok_Identifier
then
1415 -- If nothing sensible, skip to next semicolon or right paren
1419 Resync_Semicolon_List
;
1421 if Token
= Tok_Semicolon
then
1422 Scan
; -- past semicolon
1425 exit Specification_Loop
;
1428 end loop Specification_Loop
;
1430 return Specification_List
;
1433 ----------------------------------
1434 -- 6.1 Parameter Specification --
1435 ----------------------------------
1437 -- Parsed by P_Formal_Part (6.1)
1443 -- MODE ::= [in] | in out | out
1445 -- There is no explicit node in the tree for the Mode. Instead the
1446 -- In_Present and Out_Present flags are set in the parent node to
1447 -- record the presence of keywords specifying the mode.
1449 -- Error_Recovery: cannot raise Error_Resync
1451 procedure P_Mode
(Node
: Node_Id
) is
1453 if Token
= Tok_In
then
1455 Set_In_Present
(Node
, True);
1457 if Style
.Mode_In_Check
and then Token
/= Tok_Out
then
1458 Error_Msg_SP
-- CODEFIX
1459 ("(style) IN should be omitted");
1462 if Token
= Tok_Access
then
1463 Error_Msg_SP
("IN not allowed together with ACCESS");
1464 Scan
; -- past ACCESS
1468 if Token
= Tok_Out
then
1470 Set_Out_Present
(Node
, True);
1473 if Token
= Tok_In
then
1474 Error_Msg_SC
("IN must precede OUT in parameter mode");
1476 Set_In_Present
(Node
, True);
1480 --------------------------
1481 -- 6.3 Subprogram Body --
1482 --------------------------
1484 -- Parsed by P_Subprogram (6.1)
1486 -----------------------------------
1487 -- 6.4 Procedure Call Statement --
1488 -----------------------------------
1490 -- Parsed by P_Sequence_Of_Statements (5.1)
1492 ------------------------
1493 -- 6.4 Function Call --
1494 ------------------------
1496 -- Parsed by P_Call_Or_Name (4.1)
1498 --------------------------------
1499 -- 6.4 Actual Parameter Part --
1500 --------------------------------
1502 -- Parsed by P_Call_Or_Name (4.1)
1504 --------------------------------
1505 -- 6.4 Parameter Association --
1506 --------------------------------
1508 -- Parsed by P_Call_Or_Name (4.1)
1510 ------------------------------------
1511 -- 6.4 Explicit Actual Parameter --
1512 ------------------------------------
1514 -- Parsed by P_Call_Or_Name (4.1)
1516 ---------------------------
1517 -- 6.5 Return Statement --
1518 ---------------------------
1520 -- SIMPLE_RETURN_STATEMENT ::= return [EXPRESSION];
1522 -- EXTENDED_RETURN_STATEMENT ::=
1523 -- return DEFINING_IDENTIFIER : [aliased] RETURN_SUBTYPE_INDICATION
1524 -- [:= EXPRESSION] [do
1525 -- HANDLED_SEQUENCE_OF_STATEMENTS
1528 -- RETURN_SUBTYPE_INDICATION ::= SUBTYPE_INDICATION | ACCESS_DEFINITION
1530 -- RETURN_STATEMENT ::= return [EXPRESSION];
1532 -- Error recovery: can raise Error_Resync
1534 procedure P_Return_Subtype_Indication
(Decl_Node
: Node_Id
) is
1536 -- Note: We don't need to check Ada_Version here, because this is
1537 -- only called in >= Ada 2005 cases anyway.
1539 Not_Null_Present
: constant Boolean := P_Null_Exclusion
;
1542 Set_Null_Exclusion_Present
(Decl_Node
, Not_Null_Present
);
1544 if Token
= Tok_Access
then
1545 Set_Object_Definition
1546 (Decl_Node
, P_Access_Definition
(Not_Null_Present
));
1548 Set_Object_Definition
1549 (Decl_Node
, P_Subtype_Indication
(Not_Null_Present
));
1551 end P_Return_Subtype_Indication
;
1553 -- Error recovery: can raise Error_Resync
1555 function P_Return_Object_Declaration
return Node_Id
is
1556 Return_Obj
: Node_Id
;
1557 Decl_Node
: Node_Id
;
1560 Return_Obj
:= Token_Node
;
1561 Change_Identifier_To_Defining_Identifier
(Return_Obj
);
1562 Decl_Node
:= New_Node
(N_Object_Declaration
, Token_Ptr
);
1563 Set_Defining_Identifier
(Decl_Node
, Return_Obj
);
1565 Scan
; -- past identifier
1568 -- First an error check, if we have two identifiers in a row, a likely
1569 -- possibility is that the first of the identifiers is an incorrectly
1570 -- spelled keyword. See similar check in P_Identifier_Declarations.
1572 if Token
= Tok_Identifier
then
1574 SS
: Saved_Scan_State
;
1578 Save_Scan_State
(SS
);
1579 Scan
; -- past initial identifier
1580 I2
:= (Token
= Tok_Identifier
);
1581 Restore_Scan_State
(SS
);
1585 (Bad_Spelling_Of
(Tok_Access
) or else
1586 Bad_Spelling_Of
(Tok_Aliased
) or else
1587 Bad_Spelling_Of
(Tok_Constant
))
1594 -- We allow "constant" here (as in "return Result : constant
1595 -- T..."). This is not in the latest RM, but the ARG is considering an
1596 -- AI on the subject (see AI05-0015-1), which we expect to be approved.
1598 if Token
= Tok_Constant
then
1599 Scan
; -- past CONSTANT
1600 Set_Constant_Present
(Decl_Node
);
1602 if Token
= Tok_Aliased
then
1603 Error_Msg_SC
-- CODEFIX
1604 ("ALIASED should be before CONSTANT");
1605 Scan
; -- past ALIASED
1606 Set_Aliased_Present
(Decl_Node
);
1609 elsif Token
= Tok_Aliased
then
1610 Scan
; -- past ALIASED
1611 Set_Aliased_Present
(Decl_Node
);
1613 if Token
= Tok_Constant
then
1614 Scan
; -- past CONSTANT
1615 Set_Constant_Present
(Decl_Node
);
1619 P_Return_Subtype_Indication
(Decl_Node
);
1621 if Token
= Tok_Colon_Equal
then
1623 Set_Expression
(Decl_Node
, P_Expression_No_Right_Paren
);
1627 end P_Return_Object_Declaration
;
1629 -- Error recovery: can raise Error_Resync
1631 function P_Return_Statement
return Node_Id
is
1632 -- The caller has checked that the initial token is RETURN
1634 function Is_Simple
return Boolean;
1635 -- Scan state is just after RETURN (and is left that way).
1636 -- Determine whether this is a simple or extended return statement
1637 -- by looking ahead for "identifier :", which implies extended.
1643 function Is_Simple
return Boolean is
1644 Scan_State
: Saved_Scan_State
;
1645 Result
: Boolean := True;
1648 if Token
= Tok_Identifier
then
1649 Save_Scan_State
(Scan_State
); -- at identifier
1650 Scan
; -- past identifier
1652 if Token
= Tok_Colon
then
1653 Result
:= False; -- It's an extended_return_statement.
1656 Restore_Scan_State
(Scan_State
); -- to identifier
1662 Return_Sloc
: constant Source_Ptr
:= Token_Ptr
;
1663 Return_Node
: Node_Id
;
1665 -- Start of processing for P_Return_Statement
1668 Scan
; -- past RETURN
1670 -- Simple_return_statement, no expression, return an
1671 -- N_Simple_Return_Statement node with the expression field left Empty.
1673 if Token
= Tok_Semicolon
then
1675 Return_Node
:= New_Node
(N_Simple_Return_Statement
, Return_Sloc
);
1680 -- Simple_return_statement with expression
1682 -- We avoid trying to scan an expression if we are at an
1683 -- expression terminator since in that case the best error
1684 -- message is probably that we have a missing semicolon.
1687 Return_Node
:= New_Node
(N_Simple_Return_Statement
, Return_Sloc
);
1689 if Token
not in Token_Class_Eterm
then
1690 Set_Expression
(Return_Node
, P_Expression_No_Right_Paren
);
1693 -- Extended_return_statement (Ada 2005 only -- AI-318):
1696 if Ada_Version
< Ada_2005
then
1698 (" extended_return_statement is an Ada 2005 extension");
1699 Error_Msg_SP
("\unit must be compiled with -gnat05 switch");
1702 Return_Node
:= New_Node
(N_Extended_Return_Statement
, Return_Sloc
);
1703 Set_Return_Object_Declarations
1704 (Return_Node
, New_List
(P_Return_Object_Declaration
));
1706 if Token
= Tok_Do
then
1708 Scope
.Table
(Scope
.Last
).Etyp
:= E_Return
;
1709 Scope
.Table
(Scope
.Last
).Ecol
:= Start_Column
;
1710 Scope
.Table
(Scope
.Last
).Sloc
:= Return_Sloc
;
1713 Set_Handled_Statement_Sequence
1714 (Return_Node
, P_Handled_Sequence_Of_Statements
);
1717 -- Do we need to handle Error_Resync here???
1725 end P_Return_Statement
;