1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2012, 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 expression function 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
112 -- [ASPECT_SPECIFICATIONS];
114 -- SUBPROGRAM_BODY_STUB ::=
115 -- SUBPROGRAM_SPECIFICATION is separate;
117 -- GENERIC_INSTANTIATION ::=
118 -- procedure DEFINING_PROGRAM_UNIT_NAME is
119 -- new generic_procedure_NAME [GENERIC_ACTUAL_PART];
120 -- | function DEFINING_DESIGNATOR is
121 -- new generic_function_NAME [GENERIC_ACTUAL_PART];
123 -- NULL_PROCEDURE_DECLARATION ::=
124 -- SUBPROGRAM_SPECIFICATION is null;
126 -- Null procedures are an Ada 2005 feature. A null procedure declaration
127 -- is classified as a basic declarative item, but it is parsed here, with
128 -- other subprogram constructs.
130 -- EXPRESSION_FUNCTION ::=
131 -- FUNCTION SPECIFICATION IS (EXPRESSION);
133 -- The value in Pf_Flags indicates which of these possible declarations
134 -- is acceptable to the caller:
136 -- Pf_Flags.Decl Set if declaration OK
137 -- Pf_Flags.Gins Set if generic instantiation OK
138 -- Pf_Flags.Pbod Set if proper body OK
139 -- Pf_Flags.Rnam Set if renaming declaration OK
140 -- Pf_Flags.Stub Set if body stub OK
141 -- Pf_Flags.Pexp Set if expression function OK
143 -- If an inappropriate form is encountered, it is scanned out but an
144 -- error message indicating that it is appearing in an inappropriate
145 -- context is issued. The only possible values for Pf_Flags are those
146 -- defined as constants in the Par package.
148 -- The caller has checked that the initial token is FUNCTION, PROCEDURE,
149 -- NOT or OVERRIDING.
151 -- Error recovery: cannot raise Error_Resync
153 function P_Subprogram (Pf_Flags : Pf_Rec) return Node_Id is
154 Specification_Node : Node_Id;
156 Fpart_List : List_Id;
157 Fpart_Sloc : Source_Ptr;
158 Result_Not_Null : Boolean := False;
159 Result_Node : Node_Id;
163 Rename_Node : Node_Id;
164 Absdec_Node : Node_Id;
166 Fproc_Sloc : Source_Ptr;
168 Scan_State : Saved_Scan_State;
170 -- Flags for optional overriding indication. Two flags are needed,
171 -- to distinguish positive and negative overriding indicators from
172 -- the absence of any indicator.
174 Is_Overriding : Boolean := False;
175 Not_Overriding : Boolean := False;
178 -- Set up scope stack entry. Note that the Labl field will be set later
180 SIS_Entry_Active := False;
181 SIS_Missing_Semicolon_Message := No_Error_Msg;
183 Scope.Table (Scope.Last).Sloc := Token_Ptr;
184 Scope.Table (Scope.Last).Etyp := E_Name;
185 Scope.Table (Scope.Last).Ecol := Start_Column;
186 Scope.Table (Scope.Last).Lreq := False;
188 -- Ada 2005: Scan leading NOT OVERRIDING indicator
190 if Token = Tok_Not then
193 if Token = Tok_Overriding then
194 Scan; -- past OVERRIDING
195 Not_Overriding := True;
197 -- Overriding keyword used in non Ada 2005 mode
199 elsif Token = Tok_Identifier
200 and then Token_Name = Name_Overriding
202 Error_Msg_SC ("overriding indicator is an Ada 2005 extension");
203 Error_Msg_SC ("\unit must be compiled with -gnat05 switch");
204 Scan; -- past Overriding
205 Not_Overriding := True;
208 Error_Msg_SC -- CODEFIX
209 ("OVERRIDING expected!");
212 -- Ada 2005: scan leading OVERRIDING indicator
214 -- Note: in the case of OVERRIDING keyword used in Ada 95 mode, the
215 -- declaration circuit already gave an error message and changed the
216 -- token to Tok_Overriding.
218 elsif Token = Tok_Overriding then
219 Scan; -- past OVERRIDING
220 Is_Overriding := True;
223 if Is_Overriding or else Not_Overriding then
225 -- Note that if we are not in Ada_2005 mode, error messages have
226 -- already been given, so no need to give another message here.
228 -- An overriding indicator is allowed for subprogram declarations,
229 -- bodies (including subunits), renamings, stubs, and instantiations.
230 -- The test against Pf_Decl_Pbod is added to account for the case of
231 -- subprograms declared in a protected type, where only subprogram
232 -- declarations and bodies can occur. The Pf_Pbod case is for
235 if Pf_Flags /= Pf_Decl_Gins_Pbod_Rnam_Stub_Pexp
237 Pf_Flags /= Pf_Decl_Pbod_Pexp
239 Pf_Flags /= Pf_Pbod_Pexp
241 Error_Msg_SC ("overriding indicator not allowed here!");
243 elsif Token /= Tok_Function and then Token /= Tok_Procedure then
244 Error_Msg_SC -- CODEFIX
245 ("FUNCTION or PROCEDURE expected!");
249 Func := (Token = Tok_Function);
250 Fproc_Sloc := Token_Ptr;
251 Scan; -- past FUNCTION or PROCEDURE
256 Name_Node := P_Defining_Designator;
258 if Nkind (Name_Node) = N_Defining_Operator_Symbol
259 and then Scope.Last = 1
261 Error_Msg_SP ("operator symbol not allowed at library level");
262 Name_Node := New_Entity (N_Defining_Identifier, Sloc (Name_Node));
264 -- Set name from file name, we need some junk name, and that's
265 -- as good as anything. This is only approximate, since we do
266 -- not do anything with non-standard name translations.
268 Get_Name_String (File_Name (Current_Source_File));
270 for J in 1 .. Name_Len loop
271 if Name_Buffer (J) = '.' then
277 Set_Chars (Name_Node, Name_Find);
278 Set_Error_Posted (Name_Node);
282 Name_Node := P_Defining_Program_Unit_Name;
285 Scope.Table (Scope.Last).Labl := Name_Node;
288 -- Deal with generic instantiation, the one case in which we do not
289 -- have a subprogram specification as part of whatever we are parsing
291 if Token = Tok_Is then
292 Save_Scan_State (Scan_State); -- at the IS
293 T_Is; -- checks for redundant IS
295 if Token = Tok_New then
296 if not Pf_Flags.Gins then
297 Error_Msg_SC ("generic instantiation not allowed here!");
303 Inst_Node := New_Node (N_Function_Instantiation, Fproc_Sloc);
304 Set_Name (Inst_Node, P_Function_Name);
306 Inst_Node := New_Node (N_Procedure_Instantiation, Fproc_Sloc);
307 Set_Name (Inst_Node, P_Qualified_Simple_Name);
310 Set_Defining_Unit_Name (Inst_Node, Name_Node);
311 Set_Generic_Associations (Inst_Node, P_Generic_Actual_Part_Opt);
312 P_Aspect_Specifications (Inst_Node);
313 Pop_Scope_Stack; -- Don't need scope stack entry in this case
315 if Is_Overriding then
316 Set_Must_Override (Inst_Node);
318 elsif Not_Overriding then
319 Set_Must_Not_Override (Inst_Node);
325 Restore_Scan_State (Scan_State); -- to the IS
329 -- If not a generic instantiation, then we definitely have a subprogram
330 -- specification (all possibilities at this stage include one here)
332 Fpart_Sloc := Token_Ptr;
334 Check_Misspelling_Of (Tok_Return);
336 -- Scan formal part. First a special error check. If we have an
337 -- identifier here, then we have a definite error. If this identifier
338 -- is on the same line as the designator, then we assume it is the
339 -- first formal after a missing left parenthesis
341 if Token = Tok_Identifier
342 and then not Token_Is_At_Start_Of_Line
344 T_Left_Paren; -- to generate message
345 Fpart_List := P_Formal_Part;
347 -- Otherwise scan out an optional formal part in the usual manner
350 Fpart_List := P_Parameter_Profile;
353 -- We treat what we have as a function specification if FUNCTION was
354 -- used, or if a RETURN is present. This gives better error recovery
355 -- since later RETURN statements will be valid in either case.
357 Check_Junk_Semicolon_Before_Return;
358 Result_Node := Error;
360 if Token = Tok_Return then
363 ("PROCEDURE should be FUNCTION", Fproc_Sloc);
369 Result_Not_Null := P_Null_Exclusion; -- Ada 2005 (AI-231)
371 -- Ada 2005 (AI-318-02)
373 if Token = Tok_Access then
374 if Ada_Version < Ada_2005 then
376 ("anonymous access result type is an Ada 2005 extension");
377 Error_Msg_SC ("\unit must be compiled with -gnat05 switch");
380 Result_Node := P_Access_Definition (Result_Not_Null);
383 Result_Node := P_Subtype_Mark;
388 -- Skip extra parenthesis at end of formal part
390 Ignore (Tok_Right_Paren);
392 -- For function, scan result subtype
397 if Prev_Token = Tok_Return then
398 Result_Node := P_Subtype_Mark;
404 Specification_Node :=
405 New_Node (N_Function_Specification, Fproc_Sloc);
407 Set_Null_Exclusion_Present (Specification_Node, Result_Not_Null);
408 Set_Result_Definition (Specification_Node, Result_Node);
411 Specification_Node :=
412 New_Node (N_Procedure_Specification, Fproc_Sloc);
415 Set_Defining_Unit_Name (Specification_Node, Name_Node);
416 Set_Parameter_Specifications (Specification_Node, Fpart_List);
418 if Is_Overriding then
419 Set_Must_Override (Specification_Node);
421 elsif Not_Overriding then
422 Set_Must_Not_Override (Specification_Node);
425 -- Error check: barriers not allowed on protected functions/procedures
427 if Token = Tok_When then
429 Error_Msg_SC ("barrier not allowed on function, only on entry");
431 Error_Msg_SC ("barrier not allowed on procedure, only on entry");
435 Discard_Junk_Node (P_Expression);
438 -- Deal with semicolon followed by IS. We want to treat this as IS
440 if Token = Tok_Semicolon then
441 Save_Scan_State (Scan_State);
442 Scan; -- past semicolon
444 if Token = Tok_Is then
445 Error_Msg_SP -- CODEFIX
446 ("extra "";"" ignored");
448 Restore_Scan_State (Scan_State);
452 -- Subprogram declaration ended by aspect specifications
454 if Aspect_Specifications_Present then
455 goto Subprogram_Declaration;
457 -- Deal with case of semicolon ending a subprogram declaration
459 elsif Token = Tok_Semicolon then
460 if not Pf_Flags.Decl then
464 Save_Scan_State (Scan_State);
465 Scan; -- past semicolon
467 -- If semicolon is immediately followed by IS, then ignore the
468 -- semicolon, and go process the body.
470 if Token = Tok_Is then
471 Error_Msg_SP -- CODEFIX
472 ("|extra "";"" ignored");
473 T_Is; -- scan past IS
474 goto Subprogram_Body;
476 -- If BEGIN follows in an appropriate column, we immediately
477 -- commence the error action of assuming that the previous
478 -- subprogram declaration should have been a subprogram body,
479 -- i.e. that the terminating semicolon should have been IS.
481 elsif Token = Tok_Begin
482 and then Start_Column >= Scope.Table (Scope.Last).Ecol
484 Error_Msg_SP -- CODEFIX
485 ("|"";"" should be IS!");
486 goto Subprogram_Body;
489 Restore_Scan_State (Scan_State);
490 goto Subprogram_Declaration;
493 -- Case of not followed by semicolon
496 -- Subprogram renaming declaration case
498 Check_Misspelling_Of (Tok_Renames);
500 if Token = Tok_Renames then
501 if not Pf_Flags.Rnam then
502 Error_Msg_SC ("renaming declaration not allowed here!");
506 New_Node (N_Subprogram_Renaming_Declaration, Token_Ptr);
507 Scan; -- past RENAMES
508 Set_Name (Rename_Node, P_Name);
509 Set_Specification (Rename_Node, Specification_Node);
510 P_Aspect_Specifications (Rename_Node);
515 -- Case of IS following subprogram specification
517 elsif Token = Tok_Is then
518 T_Is; -- ignore redundant Is's
520 if Token_Name = Name_Abstract then
521 Check_95_Keyword (Tok_Abstract, Tok_Semicolon);
524 -- Deal nicely with (now obsolete) use of <> in place of abstract
526 if Token = Tok_Box then
527 Error_Msg_SC -- CODEFIX
528 ("ABSTRACT expected");
529 Token := Tok_Abstract;
532 -- Abstract subprogram declaration case
534 if Token = Tok_Abstract then
536 New_Node (N_Abstract_Subprogram_Declaration, Token_Ptr);
537 Set_Specification (Absdec_Node, Specification_Node);
538 Pop_Scope_Stack; -- discard unneeded entry
539 Scan; -- past ABSTRACT
540 P_Aspect_Specifications (Absdec_Node);
543 -- Ada 2005 (AI-248): Parse a null procedure declaration
545 elsif Token = Tok_Null then
546 if Ada_Version < Ada_2005 then
547 Error_Msg_SP ("null procedures are an Ada 2005 extension");
548 Error_Msg_SP ("\unit must be compiled with -gnat05 switch");
554 Error_Msg_SP ("only procedures can be null");
556 Set_Null_Present (Specification_Node);
559 goto Subprogram_Declaration;
561 -- Check for IS NEW with Formal_Part present and handle nicely
563 elsif Token = Tok_New then
565 ("formal part not allowed in instantiation", Fpart_Sloc);
569 Inst_Node := New_Node (N_Function_Instantiation, Fproc_Sloc);
572 New_Node (N_Procedure_Instantiation, Fproc_Sloc);
575 Set_Defining_Unit_Name (Inst_Node, Name_Node);
576 Set_Name (Inst_Node, P_Name);
577 Set_Generic_Associations (Inst_Node, P_Generic_Actual_Part_Opt);
579 Pop_Scope_Stack; -- Don't need scope stack entry in this case
583 goto Subprogram_Body;
586 -- Aspect specifications present
588 elsif Aspect_Specifications_Present then
589 goto Subprogram_Declaration;
591 -- Here we have a missing IS or missing semicolon, we always guess
592 -- a missing semicolon, since we are pretty good at fixing up a
593 -- semicolon which should really be an IS
596 Error_Msg_AP -- CODEFIX
598 SIS_Missing_Semicolon_Message := Get_Msg_Id;
599 goto Subprogram_Declaration;
603 -- Processing for stub or subprogram body or expression function
607 -- Subprogram body stub case
609 if Separate_Present then
610 if not Pf_Flags.Stub then
611 Error_Msg_SC ("body stub not allowed here!");
614 if Nkind (Name_Node) = N_Defining_Operator_Symbol then
616 ("operator symbol cannot be used as subunit name",
621 New_Node (N_Subprogram_Body_Stub, Sloc (Specification_Node));
622 Set_Specification (Stub_Node, Specification_Node);
623 Scan; -- past SEPARATE
628 -- Subprogram body or expression function case
631 Scan_Body_Or_Expression_Function : declare
633 Body_Is_Hidden_In_SPARK : Boolean;
634 Hidden_Region_Start : Source_Ptr;
636 function Likely_Expression_Function return Boolean;
637 -- Returns True if we have a probable case of an expression
638 -- function omitting the parentheses, if so, returns True
639 -- and emits an appropriate error message, else returns False.
641 --------------------------------
642 -- Likely_Expression_Function --
643 --------------------------------
645 function Likely_Expression_Function return Boolean is
647 -- If currently pointing to BEGIN or a declaration keyword
648 -- or a pragma, then we definitely have a subprogram body.
649 -- This is a common case, so worth testing first.
652 or else Token in Token_Class_Declk
653 or else Token = Tok_Pragma
657 -- Test for tokens which could only start an expression and
658 -- thus signal the case of a expression function.
660 elsif Token in Token_Class_Literal
661 or else Token in Token_Class_Unary_Addop
662 or else Token = Tok_Left_Paren
663 or else Token = Tok_Abs
664 or else Token = Tok_Null
665 or else Token = Tok_New
666 or else Token = Tok_Not
670 -- Anything other than an identifier must be a body
672 elsif Token /= Tok_Identifier then
675 -- Here for an identifier
678 -- If the identifier is the first token on its line, then
679 -- let's assume that we have a missing begin and this is
680 -- intended as a subprogram body. However, if the context
681 -- is a function and the unit is a package declaration, a
682 -- body would be illegal, so try for an unparenthesized
683 -- expression function.
685 if Token_Is_At_Start_Of_Line then
687 -- The enclosing scope entry is a subprogram spec
689 Spec_Node : constant Node_Id :=
691 (Scope.Table (Scope.Last).Labl);
692 Lib_Node : Node_Id := Spec_Node;
695 -- Check whether there is an enclosing scope that
696 -- is a package declaration.
698 if Scope.Last > 1 then
700 Parent (Scope.Table (Scope.Last - 1).Labl);
703 if Ada_Version >= Ada_2012
705 Nkind (Lib_Node) = N_Package_Specification
707 Nkind (Spec_Node) = N_Function_Specification
715 -- Otherwise we have to scan ahead. If the identifier is
716 -- followed by a colon or a comma, it is a declaration
717 -- and hence we have a subprogram body. Otherwise assume
718 -- a expression function.
722 Scan_State : Saved_Scan_State;
726 Save_Scan_State (Scan_State);
727 Scan; -- past identifier
729 Restore_Scan_State (Scan_State);
731 if Tok = Tok_Colon or else Tok = Tok_Comma then
738 -- Fall through if we have a likely expression function
741 ("expression function must be enclosed in parentheses");
743 end Likely_Expression_Function;
745 -- Start of processing for Scan_Body_Or_Expression_Function
748 -- Expression_Function case
750 if Token = Tok_Left_Paren
751 or else Likely_Expression_Function
753 -- Check expression function allowed here
755 if not Pf_Flags.Pexp then
756 Error_Msg_SC ("expression function not allowed here!");
759 -- Check we are in Ada 2012 mode
761 if Ada_Version < Ada_2012 then
763 ("expression function is an Ada 2012 feature!");
765 ("\unit must be compiled with -gnat2012 switch!");
768 -- Parse out expression and build expression function
772 (N_Expression_Function, Sloc (Specification_Node));
773 Set_Specification (Body_Node, Specification_Node);
774 Set_Expression (Body_Node, P_Expression);
776 -- Expression functions can carry pre/postconditions
778 P_Aspect_Specifications (Body_Node);
781 -- Subprogram body case
784 -- Check body allowed here
786 if not Pf_Flags.Pbod then
787 Error_Msg_SP ("subprogram body not allowed here!");
790 -- Here is the test for a suspicious IS (i.e. one that
791 -- looks like it might more properly be a semicolon).
792 -- See separate section describing use of IS instead
793 -- of semicolon in package Parse.
795 if (Token in Token_Class_Declk
797 Token = Tok_Identifier)
798 and then Start_Column <= Scope.Table (Scope.Last).Ecol
799 and then Scope.Last /= 1
801 Scope.Table (Scope.Last).Etyp := E_Suspicious_Is;
802 Scope.Table (Scope.Last).S_Is := Prev_Token_Ptr;
805 -- Build and return subprogram body, parsing declarations
806 -- and statement sequence that belong to the body.
809 New_Node (N_Subprogram_Body, Sloc (Specification_Node));
810 Set_Specification (Body_Node, Specification_Node);
812 -- In SPARK, a HIDE directive can be placed at the beginning
813 -- of a subprogram implementation, thus hiding the
814 -- subprogram body from SPARK tool-set. No violation of the
815 -- SPARK restriction should be issued on nodes in a hidden
816 -- part, which is obtained by marking such hidden parts.
818 if Token = Tok_SPARK_Hide then
819 Body_Is_Hidden_In_SPARK := True;
820 Hidden_Region_Start := Token_Ptr;
821 Scan; -- past HIDE directive
823 Body_Is_Hidden_In_SPARK := False;
826 Parse_Decls_Begin_End (Body_Node);
828 if Body_Is_Hidden_In_SPARK then
829 Set_Hidden_Part_In_SPARK (Hidden_Region_Start, Token_Ptr);
834 end Scan_Body_Or_Expression_Function;
837 -- Processing for subprogram declaration
839 <<Subprogram_Declaration>>
841 New_Node (N_Subprogram_Declaration, Sloc (Specification_Node));
842 Set_Specification (Decl_Node, Specification_Node);
843 P_Aspect_Specifications (Decl_Node);
845 -- If this is a context in which a subprogram body is permitted,
846 -- set active SIS entry in case (see section titled "Handling
847 -- Semicolon Used in Place of IS" in body of Parser package)
848 -- Note that SIS_Missing_Semicolon_Message is already set properly.
850 if Pf_Flags.Pbod then
851 SIS_Labl := Scope.Table (Scope.Last).Labl;
852 SIS_Sloc := Scope.Table (Scope.Last).Sloc;
853 SIS_Ecol := Scope.Table (Scope.Last).Ecol;
854 SIS_Declaration_Node := Decl_Node;
855 SIS_Semicolon_Sloc := Prev_Token_Ptr;
856 SIS_Entry_Active := True;
863 ---------------------------------
864 -- 6.1 Subprogram Declaration --
865 ---------------------------------
867 -- Parsed by P_Subprogram (6.1)
869 ------------------------------------------
870 -- 6.1 Abstract Subprogram Declaration --
871 ------------------------------------------
873 -- Parsed by P_Subprogram (6.1)
875 -----------------------------------
876 -- 6.1 Subprogram Specification --
877 -----------------------------------
879 -- SUBPROGRAM_SPECIFICATION ::=
880 -- procedure DEFINING_PROGRAM_UNIT_NAME PARAMETER_PROFILE
881 -- | function DEFINING_DESIGNATOR PARAMETER_AND_RESULT_PROFILE
883 -- PARAMETER_PROFILE ::= [FORMAL_PART]
885 -- PARAMETER_AND_RESULT_PROFILE ::= [FORMAL_PART] return SUBTYPE_MARK
887 -- Subprogram specifications that appear in subprogram declarations
888 -- are parsed by P_Subprogram (6.1). This routine is used in other
889 -- contexts where subprogram specifications occur.
891 -- Note: this routine does not affect the scope stack in any way
893 -- Error recovery: can raise Error_Resync
895 function P_Subprogram_Specification return Node_Id is
896 Specification_Node : Node_Id;
897 Result_Not_Null : Boolean;
898 Result_Node : Node_Id;
901 if Token = Tok_Function then
902 Specification_Node := New_Node (N_Function_Specification, Token_Ptr);
903 Scan; -- past FUNCTION
905 Set_Defining_Unit_Name (Specification_Node, P_Defining_Designator);
906 Set_Parameter_Specifications
907 (Specification_Node, P_Parameter_Profile);
908 Check_Junk_Semicolon_Before_Return;
911 Result_Not_Null := P_Null_Exclusion; -- Ada 2005 (AI-231)
913 -- Ada 2005 (AI-318-02)
915 if Token = Tok_Access then
916 if Ada_Version < Ada_2005 then
918 ("anonymous access result type is an Ada 2005 extension");
919 Error_Msg_SC ("\unit must be compiled with -gnat05 switch");
922 Result_Node := P_Access_Definition (Result_Not_Null);
925 Result_Node := P_Subtype_Mark;
929 Set_Null_Exclusion_Present (Specification_Node, Result_Not_Null);
930 Set_Result_Definition (Specification_Node, Result_Node);
931 return Specification_Node;
933 elsif Token = Tok_Procedure then
934 Specification_Node := New_Node (N_Procedure_Specification, Token_Ptr);
935 Scan; -- past PROCEDURE
937 Set_Defining_Unit_Name
938 (Specification_Node, P_Defining_Program_Unit_Name);
939 Set_Parameter_Specifications
940 (Specification_Node, P_Parameter_Profile);
941 return Specification_Node;
944 Error_Msg_SC ("subprogram specification expected");
947 end P_Subprogram_Specification;
949 ---------------------
951 ---------------------
954 -- [PARENT_UNIT_NAME .] IDENTIFIER | OPERATOR_SYMBOL
956 -- The caller has checked that the initial token is an identifier,
957 -- operator symbol, or string literal. Note that we don't bother to
958 -- do much error diagnosis in this routine, since it is only used for
959 -- the label on END lines, and the routines in package Par.Endh will
960 -- check that the label is appropriate.
962 -- Error recovery: cannot raise Error_Resync
964 function P_Designator return Node_Id is
965 Ident_Node : Node_Id;
967 Prefix_Node : Node_Id;
969 function Real_Dot return Boolean;
970 -- Tests if a current token is an interesting period, i.e. is followed
971 -- by an identifier or operator symbol or string literal. If not, it is
972 -- probably just incorrect punctuation to be caught by our caller. Note
973 -- that the case of an operator symbol or string literal is also an
974 -- error, but that is an error that we catch here. If the result is
975 -- True, a real dot has been scanned and we are positioned past it,
976 -- if the result is False, the scan position is unchanged.
982 function Real_Dot return Boolean is
983 Scan_State : Saved_Scan_State;
986 if Token /= Tok_Dot then
990 Save_Scan_State (Scan_State);
993 if Token = Tok_Identifier
994 or else Token = Tok_Operator_Symbol
995 or else Token = Tok_String_Literal
1000 Restore_Scan_State (Scan_State);
1006 -- Start of processing for P_Designator
1009 Ident_Node := Token_Node;
1010 Scan; -- past initial token
1012 if Prev_Token = Tok_Operator_Symbol
1013 or else Prev_Token = Tok_String_Literal
1014 or else not Real_Dot
1021 Prefix_Node := Ident_Node;
1023 -- Loop through child names, on entry to this loop, Prefix contains
1024 -- the name scanned so far, and Ident_Node is the last identifier.
1027 Name_Node := New_Node (N_Selected_Component, Prev_Token_Ptr);
1028 Set_Prefix (Name_Node, Prefix_Node);
1029 Ident_Node := P_Identifier;
1030 Set_Selector_Name (Name_Node, Ident_Node);
1031 Prefix_Node := Name_Node;
1032 exit when not Real_Dot;
1035 -- On exit from the loop, Ident_Node is the last identifier scanned,
1036 -- i.e. the defining identifier, and Prefix_Node is a node for the
1037 -- entire name, structured (incorrectly!) as a selected component.
1039 Name_Node := Prefix (Prefix_Node);
1040 Change_Node (Prefix_Node, N_Designator);
1041 Set_Name (Prefix_Node, Name_Node);
1042 Set_Identifier (Prefix_Node, Ident_Node);
1047 when Error_Resync =>
1048 while Token = Tok_Dot or else Token = Tok_Identifier loop
1055 ------------------------------
1056 -- 6.1 Defining Designator --
1057 ------------------------------
1059 -- DEFINING_DESIGNATOR ::=
1060 -- DEFINING_PROGRAM_UNIT_NAME | DEFINING_OPERATOR_SYMBOL
1062 -- Error recovery: cannot raise Error_Resync
1064 function P_Defining_Designator return Node_Id is
1066 if Token = Tok_Operator_Symbol then
1067 return P_Defining_Operator_Symbol;
1069 elsif Token = Tok_String_Literal then
1070 Error_Msg_SC ("invalid operator name");
1071 Scan; -- past junk string
1075 return P_Defining_Program_Unit_Name;
1077 end P_Defining_Designator;
1079 -------------------------------------
1080 -- 6.1 Defining Program Unit Name --
1081 -------------------------------------
1083 -- DEFINING_PROGRAM_UNIT_NAME ::=
1084 -- [PARENT_UNIT_NAME .] DEFINING_IDENTIFIER
1086 -- Note: PARENT_UNIT_NAME may be present only in 95 mode at the outer level
1088 -- Error recovery: cannot raise Error_Resync
1090 function P_Defining_Program_Unit_Name return Node_Id is
1091 Ident_Node : Node_Id;
1092 Name_Node : Node_Id;
1093 Prefix_Node : Node_Id;
1096 -- Set identifier casing if not already set and scan initial identifier
1098 if Token = Tok_Identifier
1099 and then Identifier_Casing (Current_Source_File) = Unknown
1101 Set_Identifier_Casing (Current_Source_File, Determine_Token_Casing);
1104 Ident_Node := P_Identifier (C_Dot);
1105 Merge_Identifier (Ident_Node, Tok_Return);
1107 -- Normal case (not child library unit name)
1109 if Token /= Tok_Dot then
1110 Change_Identifier_To_Defining_Identifier (Ident_Node);
1113 -- Child library unit name case
1116 if Scope.Last > 1 then
1117 Error_Msg_SP ("child unit allowed only at library level");
1120 elsif Ada_Version = Ada_83 then
1121 Error_Msg_SP ("(Ada 83) child unit not allowed!");
1125 Prefix_Node := Ident_Node;
1127 -- Loop through child names, on entry to this loop, Prefix contains
1128 -- the name scanned so far, and Ident_Node is the last identifier.
1131 exit when Token /= Tok_Dot;
1132 Name_Node := New_Node (N_Selected_Component, Token_Ptr);
1133 Scan; -- past period
1134 Set_Prefix (Name_Node, Prefix_Node);
1135 Ident_Node := P_Identifier (C_Dot);
1136 Set_Selector_Name (Name_Node, Ident_Node);
1137 Prefix_Node := Name_Node;
1140 -- On exit from the loop, Ident_Node is the last identifier scanned,
1141 -- i.e. the defining identifier, and Prefix_Node is a node for the
1142 -- entire name, structured (incorrectly!) as a selected component.
1144 Name_Node := Prefix (Prefix_Node);
1145 Change_Node (Prefix_Node, N_Defining_Program_Unit_Name);
1146 Set_Name (Prefix_Node, Name_Node);
1147 Change_Identifier_To_Defining_Identifier (Ident_Node);
1148 Set_Defining_Identifier (Prefix_Node, Ident_Node);
1150 -- All set with unit name parsed
1156 when Error_Resync =>
1157 while Token = Tok_Dot or else Token = Tok_Identifier loop
1162 end P_Defining_Program_Unit_Name;
1164 --------------------------
1165 -- 6.1 Operator Symbol --
1166 --------------------------
1168 -- OPERATOR_SYMBOL ::= STRING_LITERAL
1170 -- Operator symbol is returned by the scanner as Tok_Operator_Symbol
1172 -----------------------------------
1173 -- 6.1 Defining Operator Symbol --
1174 -----------------------------------
1176 -- DEFINING_OPERATOR_SYMBOL ::= OPERATOR_SYMBOL
1178 -- The caller has checked that the initial symbol is an operator symbol
1180 function P_Defining_Operator_Symbol return Node_Id is
1184 Op_Node := Token_Node;
1185 Change_Operator_Symbol_To_Defining_Operator_Symbol (Op_Node);
1186 Scan; -- past operator symbol
1188 end P_Defining_Operator_Symbol;
1190 ----------------------------
1191 -- 6.1 Parameter_Profile --
1192 ----------------------------
1194 -- PARAMETER_PROFILE ::= [FORMAL_PART]
1196 -- Empty is returned if no formal part is present
1198 -- Error recovery: cannot raise Error_Resync
1200 function P_Parameter_Profile return List_Id is
1202 if Token = Tok_Left_Paren then
1203 Scan; -- part left paren
1204 return P_Formal_Part;
1208 end P_Parameter_Profile;
1210 ---------------------------------------
1211 -- 6.1 Parameter And Result Profile --
1212 ---------------------------------------
1214 -- Parsed by its parent construct, which uses P_Parameter_Profile to
1215 -- parse the parameters, and P_Subtype_Mark to parse the return type.
1217 ----------------------
1218 -- 6.1 Formal part --
1219 ----------------------
1221 -- FORMAL_PART ::= (PARAMETER_SPECIFICATION {; PARAMETER_SPECIFICATION})
1223 -- PARAMETER_SPECIFICATION ::=
1224 -- DEFINING_IDENTIFIER_LIST : [ALIASED] MODE [NULL_EXCLUSION]
1225 -- SUBTYPE_MARK [:= DEFAULT_EXPRESSION]
1226 -- | DEFINING_IDENTIFIER_LIST : ACCESS_DEFINITION
1227 -- [:= DEFAULT_EXPRESSION]
1229 -- This scans the construct Formal_Part. The caller has already checked
1230 -- that the initial token is a left parenthesis, and skipped past it, so
1231 -- that on entry Token is the first token following the left parenthesis.
1233 -- Note: The ALIASED keyword is allowed only in Ada 2012 mode (AI 142)
1235 -- Error recovery: cannot raise Error_Resync
1237 function P_Formal_Part return List_Id is
1238 Specification_List : List_Id;
1239 Specification_Node : Node_Id;
1240 Scan_State : Saved_Scan_State;
1243 Ident_Sloc : Source_Ptr;
1244 Not_Null_Present : Boolean := False;
1245 Not_Null_Sloc : Source_Ptr;
1247 Idents : array (Int range 1 .. 4096) of Entity_Id;
1248 -- This array holds the list of defining identifiers. The upper bound
1249 -- of 4096 is intended to be essentially infinite, and we do not even
1250 -- bother to check for it being exceeded.
1253 Specification_List := New_List;
1254 Specification_Loop : loop
1256 if Token = Tok_Pragma then
1257 Error_Msg_SC ("pragma not allowed in formal part");
1258 Discard_Junk_Node (P_Pragma (Skipping => True));
1261 Ignore (Tok_Left_Paren);
1262 Ident_Sloc := Token_Ptr;
1263 Idents (1) := P_Defining_Identifier (C_Comma_Colon);
1267 exit Ident_Loop when Token = Tok_Colon;
1269 -- The only valid tokens are colon and comma, so if we have
1270 -- neither do a bit of investigation to see which is the
1271 -- better choice for insertion.
1273 if Token /= Tok_Comma then
1275 -- Assume colon if ALIASED, IN or OUT keyword found
1277 exit Ident_Loop when Token = Tok_Aliased or else
1278 Token = Tok_In or else
1281 -- Otherwise scan ahead
1283 Save_Scan_State (Scan_State);
1286 -- If we run into a semicolon, then assume that a
1287 -- colon was missing, e.g. Parms (X Y; ...). Also
1288 -- assume missing colon on EOF (a real disaster!)
1289 -- and on a right paren, e.g. Parms (X Y), and also
1290 -- on an assignment symbol, e.g. Parms (X Y := ..)
1292 if Token = Tok_Semicolon
1293 or else Token = Tok_Right_Paren
1294 or else Token = Tok_EOF
1295 or else Token = Tok_Colon_Equal
1297 Restore_Scan_State (Scan_State);
1300 -- If we run into a colon, assume that we had a missing
1301 -- comma, e.g. Parms (A B : ...). Also assume a missing
1302 -- comma if we hit another comma, e.g. Parms (A B, C ..)
1304 elsif Token = Tok_Colon
1305 or else Token = Tok_Comma
1307 Restore_Scan_State (Scan_State);
1312 end loop Look_Ahead;
1315 -- Here if a comma is present, or to be assumed
1318 Num_Idents := Num_Idents + 1;
1319 Idents (Num_Idents) := P_Defining_Identifier (C_Comma_Colon);
1320 end loop Ident_Loop;
1322 -- Fall through the loop on encountering a colon, or deciding
1323 -- that there is a missing colon.
1327 -- If there are multiple identifiers, we repeatedly scan the
1328 -- type and initialization expression information by resetting
1329 -- the scan pointer (so that we get completely separate trees
1330 -- for each occurrence).
1332 if Num_Idents > 1 then
1333 Save_Scan_State (Scan_State);
1336 -- Loop through defining identifiers in list
1340 Ident_List_Loop : loop
1341 Specification_Node :=
1342 New_Node (N_Parameter_Specification, Ident_Sloc);
1343 Set_Defining_Identifier (Specification_Node, Idents (Ident));
1345 -- Scan possible ALIASED for Ada 2012 (AI-142)
1347 if Token = Tok_Aliased then
1348 if Ada_Version < Ada_2012 then
1349 Error_Msg_SC ("ALIASED parameter is an Ada 2012 feature");
1351 Set_Aliased_Present (Specification_Node);
1354 Scan; -- past ALIASED
1357 -- Scan possible NOT NULL for Ada 2005 (AI-231, AI-447)
1359 Not_Null_Sloc := Token_Ptr;
1361 P_Null_Exclusion (Allow_Anonymous_In_95 => True);
1363 -- Case of ACCESS keyword present
1365 if Token = Tok_Access then
1366 Set_Null_Exclusion_Present
1367 (Specification_Node, Not_Null_Present);
1369 if Ada_Version = Ada_83 then
1370 Error_Msg_SC ("(Ada 83) access parameters not allowed");
1374 (Specification_Node,
1375 P_Access_Definition (Not_Null_Present));
1377 -- Case of IN or OUT present
1380 if Token = Tok_In or else Token = Tok_Out then
1381 if Not_Null_Present then
1383 ("`NOT NULL` can only be used with `ACCESS`",
1386 if Token = Tok_In then
1388 ("\`IN` not allowed together with `ACCESS`",
1392 ("\`OUT` not allowed together with `ACCESS`",
1397 P_Mode (Specification_Node);
1398 Not_Null_Present := P_Null_Exclusion; -- Ada 2005 (AI-231)
1401 Set_Null_Exclusion_Present
1402 (Specification_Node, Not_Null_Present);
1404 if Token = Tok_Procedure
1406 Token = Tok_Function
1408 Error_Msg_SC ("formal subprogram parameter not allowed");
1411 if Token = Tok_Left_Paren then
1412 Discard_Junk_List (P_Formal_Part);
1415 if Token = Tok_Return then
1417 Discard_Junk_Node (P_Subtype_Mark);
1420 Set_Parameter_Type (Specification_Node, Error);
1423 Set_Parameter_Type (Specification_Node, P_Subtype_Mark);
1428 Set_Expression (Specification_Node, Init_Expr_Opt (True));
1431 Set_Prev_Ids (Specification_Node, True);
1434 if Ident < Num_Idents then
1435 Set_More_Ids (Specification_Node, True);
1438 Append (Specification_Node, Specification_List);
1439 exit Ident_List_Loop when Ident = Num_Idents;
1441 Restore_Scan_State (Scan_State);
1442 end loop Ident_List_Loop;
1445 when Error_Resync =>
1446 Resync_Semicolon_List;
1449 if Token = Tok_Semicolon then
1450 Save_Scan_State (Scan_State);
1451 Scan; -- past semicolon
1453 -- If we have RETURN or IS after the semicolon, then assume
1454 -- that semicolon should have been a right parenthesis and exit
1456 if Token = Tok_Is or else Token = Tok_Return then
1457 Error_Msg_SP -- CODEFIX
1458 ("|"";"" should be "")""");
1459 exit Specification_Loop;
1462 -- If we have a declaration keyword after the semicolon, then
1463 -- assume we had a missing right parenthesis and terminate list
1465 if Token in Token_Class_Declk then
1466 Error_Msg_AP -- CODEFIX
1468 Restore_Scan_State (Scan_State);
1469 exit Specification_Loop;
1472 elsif Token = Tok_Right_Paren then
1473 Scan; -- past right paren
1474 exit Specification_Loop;
1476 -- Special check for common error of using comma instead of semicolon
1478 elsif Token = Tok_Comma then
1482 -- Special check for omitted separator
1484 elsif Token = Tok_Identifier then
1487 -- If nothing sensible, skip to next semicolon or right paren
1491 Resync_Semicolon_List;
1493 if Token = Tok_Semicolon then
1494 Scan; -- past semicolon
1497 exit Specification_Loop;
1500 end loop Specification_Loop;
1502 return Specification_List;
1505 ----------------------------------
1506 -- 6.1 Parameter Specification --
1507 ----------------------------------
1509 -- Parsed by P_Formal_Part (6.1)
1515 -- MODE ::= [in] | in out | out
1517 -- There is no explicit node in the tree for the Mode. Instead the
1518 -- In_Present and Out_Present flags are set in the parent node to
1519 -- record the presence of keywords specifying the mode.
1521 -- Error_Recovery: cannot raise Error_Resync
1523 procedure P_Mode (Node : Node_Id) is
1525 if Token = Tok_In then
1527 Set_In_Present (Node, True);
1529 if Style.Mode_In_Check and then Token /= Tok_Out then
1530 Error_Msg_SP -- CODEFIX
1531 ("(style) IN should be omitted");
1534 if Token = Tok_Access then
1535 Error_Msg_SP ("IN not allowed together with ACCESS");
1536 Scan; -- past ACCESS
1540 if Token = Tok_Out then
1542 Set_Out_Present (Node, True);
1545 if Token = Tok_In then
1546 Error_Msg_SC ("IN must precede OUT in parameter mode");
1548 Set_In_Present (Node, True);
1552 --------------------------
1553 -- 6.3 Subprogram Body --
1554 --------------------------
1556 -- Parsed by P_Subprogram (6.1)
1558 -----------------------------------
1559 -- 6.4 Procedure Call Statement --
1560 -----------------------------------
1562 -- Parsed by P_Sequence_Of_Statements (5.1)
1564 ------------------------
1565 -- 6.4 Function Call --
1566 ------------------------
1568 -- Parsed by P_Name (4.1)
1570 --------------------------------
1571 -- 6.4 Actual Parameter Part --
1572 --------------------------------
1574 -- Parsed by P_Name (4.1)
1576 --------------------------------
1577 -- 6.4 Parameter Association --
1578 --------------------------------
1580 -- Parsed by P_Name (4.1)
1582 ------------------------------------
1583 -- 6.4 Explicit Actual Parameter --
1584 ------------------------------------
1586 -- Parsed by P_Name (4.1)
1588 ---------------------------
1589 -- 6.5 Return Statement --
1590 ---------------------------
1592 -- SIMPLE_RETURN_STATEMENT ::= return [EXPRESSION];
1594 -- EXTENDED_RETURN_STATEMENT ::=
1595 -- return DEFINING_IDENTIFIER : [aliased] RETURN_SUBTYPE_INDICATION
1596 -- [:= EXPRESSION] [do
1597 -- HANDLED_SEQUENCE_OF_STATEMENTS
1600 -- RETURN_SUBTYPE_INDICATION ::= SUBTYPE_INDICATION | ACCESS_DEFINITION
1602 -- RETURN_STATEMENT ::= return [EXPRESSION];
1604 -- Error recovery: can raise Error_Resync
1606 procedure P_Return_Subtype_Indication (Decl_Node : Node_Id) is
1608 -- Note: We don't need to check Ada_Version here, because this is
1609 -- only called in >= Ada 2005 cases anyway.
1611 Not_Null_Present : constant Boolean := P_Null_Exclusion;
1614 Set_Null_Exclusion_Present (Decl_Node, Not_Null_Present);
1616 if Token = Tok_Access then
1617 Set_Object_Definition
1618 (Decl_Node, P_Access_Definition (Not_Null_Present));
1620 Set_Object_Definition
1621 (Decl_Node, P_Subtype_Indication (Not_Null_Present));
1623 end P_Return_Subtype_Indication;
1625 -- Error recovery: can raise Error_Resync
1627 function P_Return_Object_Declaration return Node_Id is
1628 Return_Obj : Node_Id;
1629 Decl_Node : Node_Id;
1632 Return_Obj := Token_Node;
1633 Change_Identifier_To_Defining_Identifier (Return_Obj);
1634 Decl_Node := New_Node (N_Object_Declaration, Token_Ptr);
1635 Set_Defining_Identifier (Decl_Node, Return_Obj);
1637 Scan; -- past identifier
1640 -- First an error check, if we have two identifiers in a row, a likely
1641 -- possibility is that the first of the identifiers is an incorrectly
1642 -- spelled keyword. See similar check in P_Identifier_Declarations.
1644 if Token = Tok_Identifier then
1646 SS : Saved_Scan_State;
1650 Save_Scan_State (SS);
1651 Scan; -- past initial identifier
1652 I2 := (Token = Tok_Identifier);
1653 Restore_Scan_State (SS);
1657 (Bad_Spelling_Of (Tok_Access) or else
1658 Bad_Spelling_Of (Tok_Aliased) or else
1659 Bad_Spelling_Of (Tok_Constant))
1666 -- We allow "constant" here (as in "return Result : constant
1667 -- T..."). This is not in the latest RM, but the ARG is considering an
1668 -- AI on the subject (see AI05-0015-1), which we expect to be approved.
1670 if Token = Tok_Constant then
1671 Scan; -- past CONSTANT
1672 Set_Constant_Present (Decl_Node);
1674 if Token = Tok_Aliased then
1675 Error_Msg_SC -- CODEFIX
1676 ("ALIASED should be before CONSTANT");
1677 Scan; -- past ALIASED
1678 Set_Aliased_Present (Decl_Node);
1681 elsif Token = Tok_Aliased then
1682 Scan; -- past ALIASED
1683 Set_Aliased_Present (Decl_Node);
1685 if Ada_Version < Ada_2012 then
1686 Error_Msg_SC -- CODEFIX
1687 ("ALIASED not allowed in extended return in Ada 2012?");
1689 Error_Msg_SC -- CODEFIX
1690 ("ALIASED not allowed in extended return");
1693 if Token = Tok_Constant then
1694 Scan; -- past CONSTANT
1695 Set_Constant_Present (Decl_Node);
1699 P_Return_Subtype_Indication (Decl_Node);
1701 if Token = Tok_Colon_Equal then
1703 Set_Expression (Decl_Node, P_Expression_No_Right_Paren);
1707 end P_Return_Object_Declaration;
1709 -- Error recovery: can raise Error_Resync
1711 function P_Return_Statement return Node_Id is
1712 -- The caller has checked that the initial token is RETURN
1714 function Is_Simple return Boolean;
1715 -- Scan state is just after RETURN (and is left that way).
1716 -- Determine whether this is a simple or extended return statement
1717 -- by looking ahead for "identifier :", which implies extended.
1723 function Is_Simple return Boolean is
1724 Scan_State : Saved_Scan_State;
1725 Result : Boolean := True;
1728 if Token = Tok_Identifier then
1729 Save_Scan_State (Scan_State); -- at identifier
1730 Scan; -- past identifier
1732 if Token = Tok_Colon then
1733 Result := False; -- It's an extended_return_statement.
1736 Restore_Scan_State (Scan_State); -- to identifier
1742 Return_Sloc : constant Source_Ptr := Token_Ptr;
1743 Return_Node : Node_Id;
1745 -- Start of processing for P_Return_Statement
1748 Scan; -- past RETURN
1750 -- Simple_return_statement, no expression, return an
1751 -- N_Simple_Return_Statement node with the expression field left Empty.
1753 if Token = Tok_Semicolon then
1755 Return_Node := New_Node (N_Simple_Return_Statement, Return_Sloc);
1760 -- Simple_return_statement with expression
1762 -- We avoid trying to scan an expression if we are at an
1763 -- expression terminator since in that case the best error
1764 -- message is probably that we have a missing semicolon.
1767 Return_Node := New_Node (N_Simple_Return_Statement, Return_Sloc);
1769 if Token not in Token_Class_Eterm then
1770 Set_Expression (Return_Node, P_Expression_No_Right_Paren);
1773 -- Extended_return_statement (Ada 2005 only -- AI-318):
1776 if Ada_Version < Ada_2005 then
1778 (" extended_return_statement is an Ada 2005 extension");
1779 Error_Msg_SP ("\unit must be compiled with -gnat05 switch");
1782 Return_Node := New_Node (N_Extended_Return_Statement, Return_Sloc);
1783 Set_Return_Object_Declarations
1784 (Return_Node, New_List (P_Return_Object_Declaration));
1786 if Token = Tok_Do then
1788 Scope.Table (Scope.Last).Etyp := E_Return;
1789 Scope.Table (Scope.Last).Ecol := Start_Column;
1790 Scope.Table (Scope.Last).Sloc := Return_Sloc;
1793 Set_Handled_Statement_Sequence
1794 (Return_Node, P_Handled_Sequence_Of_Statements);
1797 -- Do we need to handle Error_Resync here???
1805 end P_Return_Statement;