-- --
-- B o d y --
-- --
--- --
--- Copyright (C) 1992-2001 Free Software Foundation, Inc. --
+-- Copyright (C) 1992-2021, Free Software Foundation, Inc. --
-- --
-- GNAT is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
--- ware Foundation; either version 2, or (at your option) any later ver- --
+-- ware Foundation; either version 3, or (at your option) any later ver- --
-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
-- for more details. You should have received a copy of the GNU General --
--- Public License distributed with GNAT; see file COPYING. If not, write --
--- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
--- MA 02111-1307, USA. --
+-- Public License distributed with GNAT; see file COPYING3. If not, go to --
+-- http://www.gnu.org/licenses for a complete copy of the license. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
--- It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). --
+-- Extensive contributions were provided by Ada Core Technologies Inc. --
-- --
------------------------------------------------------------------------------
-- Turn off subprogram body ordering check. Subprograms are in order
-- by RM section rather than alphabetical
-with Sinfo.CN; use Sinfo.CN;
+with Sinfo.CN; use Sinfo.CN;
separate (Par)
package body Ch6 is
function P_Defining_Designator return Node_Id;
function P_Defining_Operator_Symbol return Node_Id;
+ function P_Return_Object_Declaration return Node_Id;
+
+ procedure P_Return_Subtype_Indication (Decl_Node : Node_Id);
+ -- Decl_Node is a N_Object_Declaration. Set the Null_Exclusion_Present and
+ -- Object_Definition fields of Decl_Node.
procedure Check_Junk_Semicolon_Before_Return;
-- Check for common error of junk semicolon before RETURN keyword of
- -- function specification. If present, skip over it with appropriate
- -- error message, leaving Scan_Ptr pointing to the RETURN after. This
- -- routine also deals with a possibly misspelled version of Return.
+ -- function specification. If present, skip over it with appropriate error
+ -- message, leaving Scan_Ptr pointing to the RETURN after. This routine
+ -- also deals with a possibly misspelled version of Return.
+
+ procedure No_Constraint_Maybe_Expr_Func;
+ -- Called after scanning return subtype to check for missing constraint,
+ -- taking into account the possibility of an occurrence of an expression
+ -- function where the IS has been forgotten.
----------------------------------------
-- Check_Junk_Semicolon_Before_Return --
if Token = Tok_Return then
Restore_Scan_State (Scan_State);
- Error_Msg_SC ("Unexpected semicolon ignored");
+ Error_Msg_SC -- CODEFIX
+ ("|extra "";"" ignored");
Scan; -- rescan past junk semicolon
-
else
Restore_Scan_State (Scan_State);
end if;
-
- elsif Bad_Spelling_Of (Tok_Return) then
- null;
end if;
end Check_Junk_Semicolon_Before_Return;
+ -----------------------------------
+ -- No_Constraint_Maybe_Expr_Func --
+ -----------------------------------
+
+ procedure No_Constraint_Maybe_Expr_Func is
+ begin
+ -- If we have a left paren at the start of the line, then assume this is
+ -- the case of an expression function with missing IS. We do not have to
+ -- diagnose the missing IS, that is done elsewhere. We do this game in
+ -- Ada 2012 mode where expression functions are legal.
+
+ if Token = Tok_Left_Paren
+ and Ada_Version >= Ada_2012
+ and Token_Is_At_Start_Of_Line
+ then
+ -- One exception if we have "(token .." then this is a constraint
+
+ declare
+ Scan_State : Saved_Scan_State;
+
+ begin
+ Save_Scan_State (Scan_State);
+ Scan; -- past left paren
+ Scan; -- past following token
+
+ -- If we have "(token .." then restore scan state and treat as
+ -- unexpected constraint.
+
+ if Token = Tok_Dot_Dot then
+ Restore_Scan_State (Scan_State);
+ No_Constraint;
+
+ -- Otherwise we treat this as an expression function
+
+ else
+ Restore_Scan_State (Scan_State);
+ end if;
+ end;
+
+ -- Otherwise use standard routine to check for no constraint present
+
+ else
+ No_Constraint;
+ end if;
+ end No_Constraint_Maybe_Expr_Func;
+
-----------------------------------------------------
-- 6.1 Subprogram (Also 6.3, 8.5.4, 10.1.3, 12.3) --
-----------------------------------------------------
-- This routine scans out a subprogram declaration, subprogram body,
-- subprogram renaming declaration or subprogram generic instantiation.
+ -- It also handles the new Ada 2012 expression function form
- -- SUBPROGRAM_DECLARATION ::= SUBPROGRAM_SPECIFICATION;
+ -- SUBPROGRAM_DECLARATION ::=
+ -- SUBPROGRAM_SPECIFICATION
+ -- [ASPECT_SPECIFICATIONS];
-- ABSTRACT_SUBPROGRAM_DECLARATION ::=
- -- SUBPROGRAM_SPECIFICATION is abstract;
+ -- SUBPROGRAM_SPECIFICATION is abstract
+ -- [ASPECT_SPECIFICATIONS];
-- SUBPROGRAM_SPECIFICATION ::=
-- procedure DEFINING_PROGRAM_UNIT_NAME PARAMETER_PROFILE
-- PARAMETER_AND_RESULT_PROFILE ::= [FORMAL_PART] return SUBTYPE_MARK
-- SUBPROGRAM_BODY ::=
- -- SUBPROGRAM_SPECIFICATION is
+ -- SUBPROGRAM_SPECIFICATION [ASPECT_SPECIFICATIONS] is
-- DECLARATIVE_PART
-- begin
-- HANDLED_SEQUENCE_OF_STATEMENTS
-- end [DESIGNATOR];
-- SUBPROGRAM_RENAMING_DECLARATION ::=
- -- SUBPROGRAM_SPECIFICATION renames callable_entity_NAME;
+ -- SUBPROGRAM_SPECIFICATION renames callable_entity_NAME
+ -- [ASPECT_SPECIFICATIONS];
-- SUBPROGRAM_BODY_STUB ::=
- -- SUBPROGRAM_SPECIFICATION is separate;
+ -- SUBPROGRAM_SPECIFICATION is separate
+ -- [ASPECT_SPECIFICATIONS];
-- GENERIC_INSTANTIATION ::=
-- procedure DEFINING_PROGRAM_UNIT_NAME is
- -- new generic_procedure_NAME [GENERIC_ACTUAL_PART];
+ -- new generic_procedure_NAME [GENERIC_ACTUAL_PART]
+ -- [ASPECT_SPECIFICATIONS];
-- | function DEFINING_DESIGNATOR is
- -- new generic_function_NAME [GENERIC_ACTUAL_PART];
+ -- new generic_function_NAME [GENERIC_ACTUAL_PART]
+ -- [ASPECT_SPECIFICATIONS];
+
+ -- NULL_PROCEDURE_DECLARATION ::=
+ -- SUBPROGRAM_SPECIFICATION is null;
+
+ -- Null procedures are an Ada 2005 feature. A null procedure declaration
+ -- is classified as a basic declarative item, but it is parsed here, with
+ -- other subprogram constructs.
+
+ -- EXPRESSION_FUNCTION ::=
+ -- FUNCTION SPECIFICATION IS (EXPRESSION)
+ -- [ASPECT_SPECIFICATIONS];
-- The value in Pf_Flags indicates which of these possible declarations
-- is acceptable to the caller:
-- Pf_Flags.Pbod Set if proper body OK
-- Pf_Flags.Rnam Set if renaming declaration OK
-- Pf_Flags.Stub Set if body stub OK
+ -- Pf_Flags.Pexp Set if expression function OK
-- If an inappropriate form is encountered, it is scanned out but an
-- error message indicating that it is appearing in an inappropriate
-- context is issued. The only possible values for Pf_Flags are those
-- defined as constants in the Par package.
- -- The caller has checked that the initial token is FUNCTION or PROCEDURE
+ -- The caller has checked that the initial token is FUNCTION, PROCEDURE,
+ -- NOT or OVERRIDING.
-- Error recovery: cannot raise Error_Resync
function P_Subprogram (Pf_Flags : Pf_Rec) return Node_Id is
Specification_Node : Node_Id;
- Name_Node : Node_Id;
- Fpart_List : List_Id;
- Fpart_Sloc : Source_Ptr;
- Return_Node : Node_Id;
- Inst_Node : Node_Id;
- Body_Node : Node_Id;
- Decl_Node : Node_Id;
- Rename_Node : Node_Id;
- Absdec_Node : Node_Id;
- Stub_Node : Node_Id;
- Fproc_Sloc : Source_Ptr;
- Func : Boolean;
- Scan_State : Saved_Scan_State;
+ Name_Node : Node_Id;
+ Aspects : List_Id;
+ Fpart_List : List_Id;
+ Fpart_Sloc : Source_Ptr;
+ Result_Not_Null : Boolean := False;
+ Result_Node : Node_Id;
+ Inst_Node : Node_Id;
+ Body_Node : Node_Id;
+ Decl_Node : Node_Id;
+ Rename_Node : Node_Id;
+ Absdec_Node : Node_Id;
+ Stub_Node : Node_Id;
+ Fproc_Sloc : Source_Ptr;
+ Func : Boolean;
+ Scan_State : Saved_Scan_State;
+
+ -- Flags for optional overriding indication. Two flags are needed,
+ -- to distinguish positive and negative overriding indicators from
+ -- the absence of any indicator.
+
+ Is_Overriding : Boolean := False;
+ Not_Overriding : Boolean := False;
begin
-- Set up scope stack entry. Note that the Labl field will be set later
SIS_Entry_Active := False;
+ SIS_Aspect_Import_Seen := False;
SIS_Missing_Semicolon_Message := No_Error_Msg;
Push_Scope_Stack;
- Scope.Table (Scope.Last).Sloc := Token_Ptr;
- Scope.Table (Scope.Last).Etyp := E_Name;
- Scope.Table (Scope.Last).Ecol := Start_Column;
- Scope.Table (Scope.Last).Lreq := False;
+ Scopes (Scope.Last).Sloc := Token_Ptr;
+ Scopes (Scope.Last).Etyp := E_Name;
+ Scopes (Scope.Last).Ecol := Start_Column;
+ Scopes (Scope.Last).Lreq := False;
+
+ Aspects := Empty_List;
+
+ -- Ada 2005: Scan leading NOT OVERRIDING indicator
+
+ if Token = Tok_Not then
+ Scan; -- past NOT
+
+ if Token = Tok_Overriding then
+ Scan; -- past OVERRIDING
+ Not_Overriding := True;
+
+ -- Overriding keyword used in non Ada 2005 mode
+
+ elsif Token = Tok_Identifier
+ and then Token_Name = Name_Overriding
+ then
+ Error_Msg_SC ("overriding indicator is an Ada 2005 extension");
+ Error_Msg_SC ("\unit must be compiled with -gnat05 switch");
+ Scan; -- past Overriding
+ Not_Overriding := True;
+
+ else
+ Error_Msg_SC -- CODEFIX
+ ("OVERRIDING expected!");
+ end if;
+
+ -- Ada 2005: scan leading OVERRIDING indicator
+
+ -- Note: in the case of OVERRIDING keyword used in Ada 95 mode, the
+ -- declaration circuit already gave an error message and changed the
+ -- token to Tok_Overriding.
+
+ elsif Token = Tok_Overriding then
+ Scan; -- past OVERRIDING
+ Is_Overriding := True;
+ end if;
+
+ if Is_Overriding or else Not_Overriding then
+
+ -- Note that if we are not in Ada_2005 mode, error messages have
+ -- already been given, so no need to give another message here.
+
+ -- An overriding indicator is allowed for subprogram declarations,
+ -- bodies (including subunits), renamings, stubs, and instantiations.
+ -- The test against Pf_Decl_Pbod is added to account for the case of
+ -- subprograms declared in a protected type, where only subprogram
+ -- declarations and bodies can occur. The Pf_Pbod case is for
+ -- subunits.
+
+ if Pf_Flags /= Pf_Decl_Gins_Pbod_Rnam_Stub_Pexp
+ and then
+ Pf_Flags /= Pf_Decl_Pbod_Pexp
+ and then
+ Pf_Flags /= Pf_Pbod_Pexp
+ then
+ Error_Msg_SC ("overriding indicator not allowed here!");
+
+ elsif Token /= Tok_Function and then Token /= Tok_Procedure then
+ Error_Msg_SC -- CODEFIX
+ ("FUNCTION or PROCEDURE expected!");
+ end if;
+ end if;
Func := (Token = Tok_Function);
Fproc_Sloc := Token_Ptr;
Name_Node := P_Defining_Program_Unit_Name;
end if;
- Scope.Table (Scope.Last).Labl := Name_Node;
-
- if Token = Tok_Colon then
- Error_Msg_SC ("redundant colon ignored");
- Scan; -- past colon
- end if;
+ Scopes (Scope.Last).Labl := Name_Node;
+ Current_Node := Name_Node;
+ Ignore (Tok_Colon);
-- Deal with generic instantiation, the one case in which we do not
-- have a subprogram specification as part of whatever we are parsing
if Token = Tok_Is then
Save_Scan_State (Scan_State); -- at the IS
- T_Is; -- checks for redundant IS's
+ T_Is; -- checks for redundant IS
if Token = Tok_New then
if not Pf_Flags.Gins then
Set_Defining_Unit_Name (Inst_Node, Name_Node);
Set_Generic_Associations (Inst_Node, P_Generic_Actual_Part_Opt);
- TF_Semicolon;
+ P_Aspect_Specifications (Inst_Node);
Pop_Scope_Stack; -- Don't need scope stack entry in this case
+
+ if Is_Overriding then
+ Set_Must_Override (Inst_Node);
+
+ elsif Not_Overriding then
+ Set_Must_Not_Override (Inst_Node);
+ end if;
+
return Inst_Node;
else
if Token = Tok_Identifier
and then not Token_Is_At_Start_Of_Line
then
- T_Left_Paren; -- to generate message
- Fpart_List := P_Formal_Part;
+ T_Left_Paren; -- to generate message
+ Fpart_List := P_Formal_Part;
-- Otherwise scan out an optional formal part in the usual manner
-- since later RETURN statements will be valid in either case.
Check_Junk_Semicolon_Before_Return;
- Return_Node := Error;
+ Result_Node := Error;
if Token = Tok_Return then
if not Func then
- Error_Msg ("PROCEDURE should be FUNCTION", Fproc_Sloc);
+ Error_Msg -- CODEFIX
+ ("PROCEDURE should be FUNCTION", Fproc_Sloc);
Func := True;
end if;
Scan; -- past RETURN
- Return_Node := P_Subtype_Mark;
- No_Constraint;
+
+ Result_Not_Null := P_Null_Exclusion; -- Ada 2005 (AI-231)
+
+ -- Ada 2005 (AI-318-02)
+
+ if Token = Tok_Access then
+ Error_Msg_Ada_2005_Extension ("anonymous access result type");
+
+ Result_Node := P_Access_Definition (Result_Not_Null);
+
+ else
+ Result_Node := P_Subtype_Mark;
+ No_Constraint_Maybe_Expr_Func;
+ end if;
else
+ -- Skip extra parenthesis at end of formal part
+
+ Ignore (Tok_Right_Paren);
+
+ -- For function, scan result subtype
+
if Func then
- Ignore (Tok_Right_Paren);
TF_Return;
+
+ if Prev_Token = Tok_Return then
+ Result_Node := P_Subtype_Mark;
+ end if;
end if;
end if;
if Func then
Specification_Node :=
New_Node (N_Function_Specification, Fproc_Sloc);
- Set_Subtype_Mark (Specification_Node, Return_Node);
+
+ Set_Null_Exclusion_Present (Specification_Node, Result_Not_Null);
+ Set_Result_Definition (Specification_Node, Result_Node);
else
Specification_Node :=
Set_Defining_Unit_Name (Specification_Node, Name_Node);
Set_Parameter_Specifications (Specification_Node, Fpart_List);
+ if Is_Overriding then
+ Set_Must_Override (Specification_Node);
+
+ elsif Not_Overriding then
+ Set_Must_Not_Override (Specification_Node);
+ end if;
+
-- Error check: barriers not allowed on protected functions/procedures
if Token = Tok_When then
Discard_Junk_Node (P_Expression);
end if;
- -- Deal with case of semicolon ending a subprogram declaration
+ -- Deal with semicolon followed by IS. We want to treat this as IS
if Token = Tok_Semicolon then
+ Save_Scan_State (Scan_State);
+ Scan; -- past semicolon
+
+ if Token = Tok_Is then
+ Error_Msg_SP -- CODEFIX
+ ("extra "";"" ignored");
+ else
+ Restore_Scan_State (Scan_State);
+ end if;
+ end if;
+
+ -- Subprogram declaration ended by aspect specifications
+
+ if Aspect_Specifications_Present then
+ goto Subprogram_Declaration;
+
+ -- Deal with case of semicolon ending a subprogram declaration
+
+ elsif Token = Tok_Semicolon then
if not Pf_Flags.Decl then
T_Is;
end if;
+ Save_Scan_State (Scan_State);
Scan; -- past semicolon
-- If semicolon is immediately followed by IS, then ignore the
-- semicolon, and go process the body.
if Token = Tok_Is then
- Error_Msg_SP ("unexpected semicolon ignored");
- T_Is; -- ignroe redundant IS's
+ Error_Msg_SP -- CODEFIX
+ ("|extra "";"" ignored");
+ T_Is; -- scan past IS
goto Subprogram_Body;
-- If BEGIN follows in an appropriate column, we immediately
-- i.e. that the terminating semicolon should have been IS.
elsif Token = Tok_Begin
- and then Start_Column >= Scope.Table (Scope.Last).Ecol
+ and then Start_Column >= Scopes (Scope.Last).Ecol
then
- Error_Msg_SP (""";"" should be IS!");
+ Error_Msg_SP -- CODEFIX
+ ("|"";"" should be IS!");
goto Subprogram_Body;
else
+ Restore_Scan_State (Scan_State);
goto Subprogram_Declaration;
end if;
Scan; -- past RENAMES
Set_Name (Rename_Node, P_Name);
Set_Specification (Rename_Node, Specification_Node);
+ P_Aspect_Specifications (Rename_Node);
TF_Semicolon;
Pop_Scope_Stack;
return Rename_Node;
-- Deal nicely with (now obsolete) use of <> in place of abstract
if Token = Tok_Box then
- Error_Msg_SC ("ABSTRACT expected");
+ Error_Msg_SC -- CODEFIX
+ ("ABSTRACT expected");
Token := Tok_Abstract;
end if;
Set_Specification (Absdec_Node, Specification_Node);
Pop_Scope_Stack; -- discard unneeded entry
Scan; -- past ABSTRACT
- TF_Semicolon;
+ P_Aspect_Specifications (Absdec_Node);
return Absdec_Node;
+ -- Ada 2005 (AI-248): Parse a null procedure declaration
+
+ elsif Token = Tok_Null then
+ Error_Msg_Ada_2005_Extension ("null procedure");
+
+ Scan; -- past NULL
+
+ if Func then
+ Error_Msg_SP ("only procedures can be null");
+ else
+ Set_Null_Present (Specification_Node);
+ Set_Null_Statement (Specification_Node,
+ New_Node (N_Null_Statement, Prev_Token_Ptr));
+ end if;
+
+ goto Subprogram_Declaration;
+
-- Check for IS NEW with Formal_Part present and handle nicely
elsif Token = Tok_New then
goto Subprogram_Body;
end if;
- -- Here we have a missing IS or missing semicolon, we always guess
- -- a missing semicolon, since we are pretty good at fixing up a
- -- semicolon which should really be an IS
+ -- Aspect specifications present
- else
- Error_Msg_AP ("missing "";""");
- SIS_Missing_Semicolon_Message := Get_Msg_Id;
+ elsif Aspect_Specifications_Present then
goto Subprogram_Declaration;
+
+ -- Here we have a missing IS or missing semicolon
+
+ else
+ -- If the next token is a left paren at the start of a line, then
+ -- this is almost certainly the start of the expression for an
+ -- expression function, so in this case guess a missing IS.
+
+ if Token = Tok_Left_Paren and then Token_Is_At_Start_Of_Line then
+ Error_Msg_AP -- CODEFIX
+ ("missing IS");
+
+ -- In all other cases, we guess a missing semicolon, since we are
+ -- good at fixing up a semicolon which should really be an IS.
+
+ else
+ Error_Msg_AP -- CODEFIX
+ ("|missing "";""");
+ SIS_Missing_Semicolon_Message := Get_Msg_Id;
+ goto Subprogram_Declaration;
+ end if;
end if;
end if;
- -- Processing for subprogram body
+ -- Processing for stub or subprogram body or expression function
<<Subprogram_Body>>
- if not Pf_Flags.Pbod then
- Error_Msg_SP ("subprogram body not allowed here!");
- end if;
-- Subprogram body stub case
Sloc (Name_Node));
end if;
+ Scan; -- past SEPARATE
+
Stub_Node :=
New_Node (N_Subprogram_Body_Stub, Sloc (Specification_Node));
Set_Specification (Stub_Node, Specification_Node);
- Scan; -- past SEPARATE
- Pop_Scope_Stack;
+
+ if Is_Non_Empty_List (Aspects) then
+ Error_Msg
+ ("aspect specifications must come after SEPARATE",
+ Sloc (First (Aspects)));
+ end if;
+
+ P_Aspect_Specifications (Stub_Node, Semicolon => False);
TF_Semicolon;
+ Pop_Scope_Stack;
return Stub_Node;
- -- Subprogram body case
+ -- Subprogram body or expression function case
else
- -- Here is the test for a suspicious IS (i.e. one that looks
- -- like it might more properly be a semicolon). See separate
- -- section discussing use of IS instead of semicolon in
- -- package Parse.
-
- if (Token in Token_Class_Declk
- or else
- Token = Tok_Identifier)
- and then Start_Column <= Scope.Table (Scope.Last).Ecol
- and then Scope.Last /= 1
- then
- Scope.Table (Scope.Last).Etyp := E_Suspicious_Is;
- Scope.Table (Scope.Last).S_Is := Prev_Token_Ptr;
- end if;
+ Scan_Body_Or_Expression_Function : declare
+
+ function Likely_Expression_Function return Boolean;
+ -- Returns True if we have a probable case of an expression
+ -- function omitting the parentheses, if so, returns True
+ -- and emits an appropriate error message, else returns False.
+
+ --------------------------------
+ -- Likely_Expression_Function --
+ --------------------------------
+
+ function Likely_Expression_Function return Boolean is
+ begin
+ -- If currently pointing to BEGIN or a declaration keyword
+ -- or a pragma, then we definitely have a subprogram body.
+ -- This is a common case, so worth testing first.
+
+ if Token = Tok_Begin
+ or else Token in Token_Class_Declk
+ or else Token = Tok_Pragma
+ then
+ return False;
+
+ -- Test for tokens which could only start an expression and
+ -- thus signal the case of a expression function.
+
+ elsif Token in Token_Class_Literal
+ or else Token in Token_Class_Unary_Addop
+ or else Token = Tok_Left_Paren
+ or else Token = Tok_Abs
+ or else Token = Tok_Null
+ or else Token = Tok_New
+ or else Token = Tok_Not
+ then
+ null;
+
+ -- Anything other than an identifier must be a body
+
+ elsif Token /= Tok_Identifier then
+ return False;
+
+ -- Here for an identifier
+
+ else
+ -- If the identifier is the first token on its line, then
+ -- let's assume that we have a missing begin and this is
+ -- intended as a subprogram body. However, if the context
+ -- is a function and the unit is a package declaration, a
+ -- body would be illegal, so try for an unparenthesized
+ -- expression function.
+
+ if Token_Is_At_Start_Of_Line then
+ declare
+ -- The enclosing scope entry is a subprogram spec
+
+ Spec_Node : constant Node_Id :=
+ Parent
+ (Scopes (Scope.Last).Labl);
+ Lib_Node : Node_Id := Spec_Node;
+
+ begin
+ -- Check whether there is an enclosing scope that
+ -- is a package declaration.
+
+ if Scope.Last > 1 then
+ Lib_Node :=
+ Parent (Scopes (Scope.Last - 1).Labl);
+ end if;
+
+ if Ada_Version >= Ada_2012
+ and then
+ Nkind (Lib_Node) = N_Package_Specification
+ and then
+ Nkind (Spec_Node) = N_Function_Specification
+ then
+ null;
+ else
+ return False;
+ end if;
+ end;
+
+ -- Otherwise we have to scan ahead. If the identifier is
+ -- followed by a colon or a comma, it is a declaration
+ -- and hence we have a subprogram body. Otherwise assume
+ -- a expression function.
+
+ else
+ declare
+ Scan_State : Saved_Scan_State;
+ Tok : Token_Type;
+
+ begin
+ Save_Scan_State (Scan_State);
+ Scan; -- past identifier
+ Tok := Token;
+ Restore_Scan_State (Scan_State);
+
+ if Tok = Tok_Colon or else Tok = Tok_Comma then
+ return False;
+ end if;
+ end;
+ end if;
+ end if;
+
+ -- Fall through if we have a likely expression function.
+ -- If the starting keyword is not "function" the error
+ -- will be reported elsewhere.
+
+ if Func then
+ Error_Msg_SC
+ ("expression function must be enclosed in parentheses");
+ end if;
+
+ return True;
+ end Likely_Expression_Function;
+
+ -- Start of processing for Scan_Body_Or_Expression_Function
+
+ begin
+ -- Expression_Function case
+
+ if Token = Tok_Left_Paren
+ or else Likely_Expression_Function
+ then
+ -- Check expression function allowed here
+
+ if not Pf_Flags.Pexp then
+ Error_Msg_SC ("expression function not allowed here!");
+ end if;
+
+ -- Check we are in Ada 2012 mode
+
+ Error_Msg_Ada_2012_Feature
+ ("!expression function", Token_Ptr);
+
+ -- Catch an illegal placement of the aspect specification
+ -- list:
+
+ -- function_specification
+ -- [aspect_specification] is (expression);
+
+ -- This case is correctly processed by the parser because
+ -- the expression function first appears as a subprogram
+ -- declaration to the parser. The starting keyword may
+ -- not have been "function" in which case the error is
+ -- on a malformed procedure.
+
+ if Is_Non_Empty_List (Aspects) then
+ if Func then
+ Error_Msg
+ ("aspect specifications must come after "
+ & "parenthesized expression",
+ Sloc (First (Aspects)));
+ else
+ Error_Msg
+ ("aspect specifications must come after subprogram "
+ & "specification", Sloc (First (Aspects)));
+ end if;
+ end if;
+
+ -- Parse out expression and build expression function
+
+ Body_Node :=
+ New_Node
+ (N_Expression_Function, Sloc (Specification_Node));
+ Set_Specification (Body_Node, Specification_Node);
+
+ declare
+ Expr : constant Node_Id := P_Expression;
+ begin
+ Set_Expression (Body_Node, Expr);
+
+ -- Check that the full expression is properly
+ -- parenthesized since we may have a left-operand that is
+ -- parenthesized but that is not one of the allowed cases
+ -- with syntactic parentheses.
+
+ if not (Paren_Count (Expr) /= 0
+ or else Nkind (Expr) in N_Aggregate
+ | N_Extension_Aggregate
+ | N_Quantified_Expression)
+ then
+ Error_Msg
+ ("expression function must be enclosed in "
+ & "parentheses", Sloc (Expr));
+ end if;
+ end;
+
+ -- Expression functions can carry pre/postconditions
+
+ P_Aspect_Specifications (Body_Node);
+ Pop_Scope_Stack;
+
+ -- Subprogram body case
+
+ else
+ -- Check body allowed here
+
+ if not Pf_Flags.Pbod then
+ Error_Msg_SP ("subprogram body not allowed here!");
+ end if;
+
+ -- Here is the test for a suspicious IS (i.e. one that
+ -- looks like it might more properly be a semicolon).
+ -- See separate section describing use of IS instead
+ -- of semicolon in package Parse.
- Body_Node :=
- New_Node (N_Subprogram_Body, Sloc (Specification_Node));
- Set_Specification (Body_Node, Specification_Node);
- Parse_Decls_Begin_End (Body_Node);
- return Body_Node;
+ if (Token in Token_Class_Declk
+ or else
+ Token = Tok_Identifier)
+ and then Start_Column <= Scopes (Scope.Last).Ecol
+ and then Scope.Last /= 1
+ then
+ Scopes (Scope.Last).Etyp := E_Suspicious_Is;
+ Scopes (Scope.Last).S_Is := Prev_Token_Ptr;
+ end if;
+
+ -- Build and return subprogram body, parsing declarations
+ -- and statement sequence that belong to the body.
+
+ Body_Node :=
+ New_Node (N_Subprogram_Body, Sloc (Specification_Node));
+ Set_Specification (Body_Node, Specification_Node);
+
+ -- If aspects are present, the specification is parsed as
+ -- a subprogram declaration, and we jump here after seeing
+ -- the keyword IS. Attach asspects previously collected to
+ -- the body.
+
+ if Is_Non_Empty_List (Aspects) then
+ Set_Parent (Aspects, Body_Node);
+ Set_Aspect_Specifications (Body_Node, Aspects);
+ end if;
+
+ Parse_Decls_Begin_End (Body_Node);
+ end if;
+
+ return Body_Node;
+ end Scan_Body_Or_Expression_Function;
end if;
-- Processing for subprogram declaration
Decl_Node :=
New_Node (N_Subprogram_Declaration, Sloc (Specification_Node));
Set_Specification (Decl_Node, Specification_Node);
+ Aspects := Get_Aspect_Specifications (Semicolon => False);
+
+ -- Aspects may be present on a subprogram body. The source parsed
+ -- so far is that of its specification. Go parse the body and attach
+ -- the collected aspects, if any, to the body.
+
+ if Token = Tok_Is then
+
+ -- If the subprogram is a procedure and already has a
+ -- specification, we can't define another.
+
+ if Nkind (Specification (Decl_Node)) = N_Procedure_Specification
+ and then Null_Present (Specification (Decl_Node))
+ then
+ Error_Msg_AP ("null procedure cannot have a body");
+ end if;
+
+ Scan;
+ goto Subprogram_Body;
+
+ else
+ if Is_Non_Empty_List (Aspects) then
+ Set_Parent (Aspects, Decl_Node);
+ Set_Aspect_Specifications (Decl_Node, Aspects);
+ end if;
+
+ TF_Semicolon;
+ end if;
-- If this is a context in which a subprogram body is permitted,
-- set active SIS entry in case (see section titled "Handling
-- Semicolon Used in Place of IS" in body of Parser package)
-- Note that SIS_Missing_Semicolon_Message is already set properly.
- if Pf_Flags.Pbod then
- SIS_Labl := Scope.Table (Scope.Last).Labl;
- SIS_Sloc := Scope.Table (Scope.Last).Sloc;
- SIS_Ecol := Scope.Table (Scope.Last).Ecol;
+ if Pf_Flags.Pbod
+
+ -- Disconnect this processing if we have scanned a null procedure
+ -- because in this case the spec is complete anyway with no body.
+
+ and then (Nkind (Specification_Node) /= N_Procedure_Specification
+ or else not Null_Present (Specification_Node))
+ then
+ SIS_Labl := Scopes (Scope.Last).Labl;
+ SIS_Sloc := Scopes (Scope.Last).Sloc;
+ SIS_Ecol := Scopes (Scope.Last).Ecol;
SIS_Declaration_Node := Decl_Node;
SIS_Semicolon_Sloc := Prev_Token_Ptr;
- SIS_Entry_Active := True;
+
+ -- Do not activate the entry if we have "with Import"
+
+ if not SIS_Aspect_Import_Seen then
+ SIS_Entry_Active := True;
+ end if;
end if;
Pop_Scope_Stack;
return Decl_Node;
-
end P_Subprogram;
---------------------------------
function P_Subprogram_Specification return Node_Id is
Specification_Node : Node_Id;
+ Result_Not_Null : Boolean;
+ Result_Node : Node_Id;
begin
if Token = Tok_Function then
(Specification_Node, P_Parameter_Profile);
Check_Junk_Semicolon_Before_Return;
TF_Return;
- Set_Subtype_Mark (Specification_Node, P_Subtype_Mark);
- No_Constraint;
+
+ Result_Not_Null := P_Null_Exclusion; -- Ada 2005 (AI-231)
+
+ -- Ada 2005 (AI-318-02)
+
+ if Token = Tok_Access then
+ Error_Msg_Ada_2005_Extension ("anonymous access result type");
+
+ Result_Node := P_Access_Definition (Result_Not_Null);
+
+ else
+ Result_Node := P_Subtype_Mark;
+ No_Constraint_Maybe_Expr_Func;
+ end if;
+
+ Set_Null_Exclusion_Present (Specification_Node, Result_Not_Null);
+ Set_Result_Definition (Specification_Node, Result_Node);
return Specification_Node;
elsif Token = Tok_Procedure then
-- True, a real dot has been scanned and we are positioned past it,
-- if the result is False, the scan position is unchanged.
+ --------------
+ -- Real_Dot --
+ --------------
+
function Real_Dot return Boolean is
Scan_State : Saved_Scan_State;
-- On exit from the loop, Ident_Node is the last identifier scanned,
-- i.e. the defining identifier, and Prefix_Node is a node for the
- -- entire name, structured (incorrectly!) as a selected component.
+ -- entire name, structured (incorrectly) as a selected component.
Name_Node := Prefix (Prefix_Node);
Change_Node (Prefix_Node, N_Designator);
Set_Identifier_Casing (Current_Source_File, Determine_Token_Casing);
end if;
- Ident_Node := P_Identifier;
+ Ident_Node := P_Identifier (C_Dot);
Merge_Identifier (Ident_Node, Tok_Return);
-- Normal case (not child library unit name)
if Token /= Tok_Dot then
Change_Identifier_To_Defining_Identifier (Ident_Node);
+ Warn_If_Standard_Redefinition (Ident_Node);
return Ident_Node;
-- Child library unit name case
Error_Msg_SP ("child unit allowed only at library level");
raise Error_Resync;
- elsif Ada_83 then
+ elsif Ada_Version = Ada_83 then
Error_Msg_SP ("(Ada 83) child unit not allowed!");
end if;
Name_Node := New_Node (N_Selected_Component, Token_Ptr);
Scan; -- past period
Set_Prefix (Name_Node, Prefix_Node);
- Ident_Node := P_Identifier;
+ Ident_Node := P_Identifier (C_Dot);
Set_Selector_Name (Name_Node, Ident_Node);
Prefix_Node := Name_Node;
end loop;
-- On exit from the loop, Ident_Node is the last identifier scanned,
-- i.e. the defining identifier, and Prefix_Node is a node for the
- -- entire name, structured (incorrectly!) as a selected component.
+ -- entire name, structured (incorrectly) as a selected component.
Name_Node := Prefix (Prefix_Node);
Change_Node (Prefix_Node, N_Defining_Program_Unit_Name);
Set_Name (Prefix_Node, Name_Node);
Change_Identifier_To_Defining_Identifier (Ident_Node);
+ Warn_If_Standard_Redefinition (Ident_Node);
Set_Defining_Identifier (Prefix_Node, Ident_Node);
-- All set with unit name parsed
-- FORMAL_PART ::= (PARAMETER_SPECIFICATION {; PARAMETER_SPECIFICATION})
-- PARAMETER_SPECIFICATION ::=
- -- DEFINING_IDENTIFIER_LIST : MODE SUBTYPE_MARK
- -- [:= DEFAULT_EXPRESSION]
+ -- DEFINING_IDENTIFIER_LIST : [ALIASED] MODE [NULL_EXCLUSION]
+ -- SUBTYPE_MARK [:= DEFAULT_EXPRESSION]
-- | DEFINING_IDENTIFIER_LIST : ACCESS_DEFINITION
-- [:= DEFAULT_EXPRESSION]
-- that the initial token is a left parenthesis, and skipped past it, so
-- that on entry Token is the first token following the left parenthesis.
+ -- Note: The ALIASED keyword is allowed only in Ada 2012 mode (AI 142)
+
-- Error recovery: cannot raise Error_Resync
function P_Formal_Part return List_Id is
Num_Idents : Nat;
Ident : Nat;
Ident_Sloc : Source_Ptr;
+ Not_Null_Present : Boolean := False;
+ Not_Null_Sloc : Source_Ptr;
Idents : array (Int range 1 .. 4096) of Entity_Id;
-- This array holds the list of defining identifiers. The upper bound
begin
Specification_List := New_List;
-
Specification_Loop : loop
begin
if Token = Tok_Pragma then
- P_Pragmas_Misplaced;
+ Error_Msg_SC ("pragma not allowed in formal part");
+ Discard_Junk_Node (P_Pragma (Skipping => True));
end if;
Ignore (Tok_Left_Paren);
Ident_Sloc := Token_Ptr;
- Idents (1) := P_Defining_Identifier;
+ Idents (1) := P_Defining_Identifier (C_Comma_Colon);
Num_Idents := 1;
Ident_Loop : loop
if Token /= Tok_Comma then
- -- Assume colon if IN or OUT keyword found
+ -- Assume colon if ALIASED, IN or OUT keyword found
- exit Ident_Loop when Token = Tok_In or else Token = Tok_Out;
+ exit Ident_Loop when Token = Tok_Aliased or else
+ Token = Tok_In or else
+ Token = Tok_Out;
-- Otherwise scan ahead
Look_Ahead : loop
-- If we run into a semicolon, then assume that a
- -- colon was missing, e.g. Parms (X Y; ...). Also
- -- assume missing colon on EOF (a real disaster!)
+ -- colon was missing, e.g. Parms (X Y; ...). Also
+ -- assume missing colon on EOF (a real disaster)
-- and on a right paren, e.g. Parms (X Y), and also
-- on an assignment symbol, e.g. Parms (X Y := ..)
T_Comma;
Num_Idents := Num_Idents + 1;
- Idents (Num_Idents) := P_Defining_Identifier;
+ Idents (Num_Idents) := P_Defining_Identifier (C_Comma_Colon);
end loop Ident_Loop;
-- Fall through the loop on encountering a colon, or deciding
New_Node (N_Parameter_Specification, Ident_Sloc);
Set_Defining_Identifier (Specification_Node, Idents (Ident));
+ -- Scan possible ALIASED for Ada 2012 (AI-142)
+
+ if Token = Tok_Aliased then
+ if Ada_Version < Ada_2012 then
+ Error_Msg_Ada_2012_Feature
+ ("ALIASED parameter", Token_Ptr);
+ else
+ Set_Aliased_Present (Specification_Node);
+ end if;
+
+ Scan; -- past ALIASED
+ end if;
+
+ -- Scan possible NOT NULL for Ada 2005 (AI-231, AI-447)
+
+ Not_Null_Sloc := Token_Ptr;
+ Not_Null_Present :=
+ P_Null_Exclusion (Allow_Anonymous_In_95 => True);
+
+ -- Case of ACCESS keyword present
+
if Token = Tok_Access then
- if Ada_83 then
+ Set_Null_Exclusion_Present
+ (Specification_Node, Not_Null_Present);
+
+ if Ada_Version = Ada_83 then
Error_Msg_SC ("(Ada 83) access parameters not allowed");
end if;
Set_Parameter_Type
- (Specification_Node, P_Access_Definition);
+ (Specification_Node,
+ P_Access_Definition (Not_Null_Present));
+
+ -- Case of IN or OUT present
else
- P_Mode (Specification_Node);
+ if Token = Tok_In or else Token = Tok_Out then
+ if Not_Null_Present then
+ Error_Msg
+ ("`NOT NULL` can only be used with `ACCESS`",
+ Not_Null_Sloc);
+
+ if Token = Tok_In then
+ Error_Msg
+ ("\`IN` not allowed together with `ACCESS`",
+ Not_Null_Sloc);
+ else
+ Error_Msg
+ ("\`OUT` not allowed together with `ACCESS`",
+ Not_Null_Sloc);
+ end if;
+ end if;
+
+ P_Mode (Specification_Node);
+ Not_Null_Present := P_Null_Exclusion; -- Ada 2005 (AI-231)
+ end if;
+
+ Set_Null_Exclusion_Present
+ (Specification_Node, Not_Null_Present);
if Token = Tok_Procedure
or else
end;
if Token = Tok_Semicolon then
+ Save_Scan_State (Scan_State);
Scan; -- past semicolon
-- If we have RETURN or IS after the semicolon, then assume
-- that semicolon should have been a right parenthesis and exit
if Token = Tok_Is or else Token = Tok_Return then
- Error_Msg_SP ("expected "")"" in place of "";""");
+ Error_Msg_SP -- CODEFIX
+ ("|"";"" should be "")""");
+ exit Specification_Loop;
+ end if;
+
+ -- If we have a declaration keyword after the semicolon, then
+ -- assume we had a missing right parenthesis and terminate list
+
+ if Token in Token_Class_Declk then
+ Error_Msg_AP -- CODEFIX
+ ("missing "")""");
+ Restore_Scan_State (Scan_State);
exit Specification_Loop;
end if;
Scan; -- past right paren
exit Specification_Loop;
+ -- Support for aspects on formal parameters is a GNAT extension for
+ -- the time being.
+
+ elsif Token = Tok_With then
+ Error_Msg_Ada_2022_Feature
+ ("aspect on formal parameter", Token_Ptr);
+
+ P_Aspect_Specifications (Specification_Node, False);
+
+ if Token = Tok_Right_Paren then
+ Scan; -- past right paren
+ exit Specification_Loop;
+
+ elsif Token = Tok_Semicolon then
+ Save_Scan_State (Scan_State);
+ Scan; -- past semicolon
+ end if;
+
-- Special check for common error of using comma instead of semicolon
elsif Token = Tok_Comma then
T_Semicolon;
- Scan; -- past comma
-- Special check for omitted separator
if Token = Tok_In then
Scan; -- past IN
Set_In_Present (Node, True);
+
+ if Style.Mode_In_Check and then Token /= Tok_Out then
+ Error_Msg_SP -- CODEFIX
+ ("(style) IN should be omitted");
+ end if;
+
+ -- Since Ada 2005, formal objects can have an anonymous access type,
+ -- and of course carry a mode indicator.
+
+ if Token = Tok_Access
+ and then Nkind (Node) /= N_Formal_Object_Declaration
+ then
+ Error_Msg_SP ("IN not allowed together with ACCESS");
+ Scan; -- past ACCESS
+ end if;
end if;
if Token = Tok_Out then
-- 6.4 Function Call --
------------------------
- -- Parsed by P_Call_Or_Name (4.1)
+ -- Parsed by P_Name (4.1)
--------------------------------
-- 6.4 Actual Parameter Part --
--------------------------------
- -- Parsed by P_Call_Or_Name (4.1)
+ -- Parsed by P_Name (4.1)
--------------------------------
-- 6.4 Parameter Association --
--------------------------------
- -- Parsed by P_Call_Or_Name (4.1)
+ -- Parsed by P_Name (4.1)
------------------------------------
-- 6.4 Explicit Actual Parameter --
------------------------------------
- -- Parsed by P_Call_Or_Name (4.1)
+ -- Parsed by P_Name (4.1)
---------------------------
-- 6.5 Return Statement --
---------------------------
+ -- SIMPLE_RETURN_STATEMENT ::= return [EXPRESSION];
+ --
+ -- EXTENDED_RETURN_STATEMENT ::=
+ -- return DEFINING_IDENTIFIER : [aliased] RETURN_SUBTYPE_INDICATION
+ -- [:= EXPRESSION]
+ -- [ASPECT_SPECIFICATION] [do
+ -- HANDLED_SEQUENCE_OF_STATEMENTS
+ -- end return];
+ --
+ -- RETURN_SUBTYPE_INDICATION ::= SUBTYPE_INDICATION | ACCESS_DEFINITION
+
-- RETURN_STATEMENT ::= return [EXPRESSION];
- -- The caller has checked that the initial token is RETURN
+ -- Error recovery: can raise Error_Resync
+
+ procedure P_Return_Subtype_Indication (Decl_Node : Node_Id) is
+
+ -- Note: We don't need to check Ada_Version here, because this is
+ -- only called in >= Ada 2005 cases anyway.
+
+ Not_Null_Present : constant Boolean := P_Null_Exclusion;
+
+ begin
+ Set_Null_Exclusion_Present (Decl_Node, Not_Null_Present);
+
+ if Token = Tok_Access then
+ Set_Object_Definition
+ (Decl_Node, P_Access_Definition (Not_Null_Present));
+ else
+ Set_Object_Definition
+ (Decl_Node, P_Subtype_Indication (Not_Null_Present));
+ end if;
+ end P_Return_Subtype_Indication;
-- Error recovery: can raise Error_Resync
- function P_Return_Statement return Node_Id is
- Return_Node : Node_Id;
+ function P_Return_Object_Declaration return Node_Id is
+ Return_Obj : Node_Id;
+ Decl_Node : Node_Id;
begin
- Return_Node := New_Node (N_Return_Statement, Token_Ptr);
+ Return_Obj := Token_Node;
+ Change_Identifier_To_Defining_Identifier (Return_Obj);
+ Warn_If_Standard_Redefinition (Return_Obj);
+ Decl_Node := New_Node (N_Object_Declaration, Token_Ptr);
+ Set_Defining_Identifier (Decl_Node, Return_Obj);
+
+ Scan; -- past identifier
+ Scan; -- past :
+
+ -- First an error check, if we have two identifiers in a row, a likely
+ -- possibility is that the first of the identifiers is an incorrectly
+ -- spelled keyword. See similar check in P_Identifier_Declarations.
+
+ if Token = Tok_Identifier then
+ declare
+ SS : Saved_Scan_State;
+ I2 : Boolean;
+
+ begin
+ Save_Scan_State (SS);
+ Scan; -- past initial identifier
+ I2 := (Token = Tok_Identifier);
+ Restore_Scan_State (SS);
+
+ if I2
+ and then
+ (Bad_Spelling_Of (Tok_Access) or else
+ Bad_Spelling_Of (Tok_Aliased) or else
+ Bad_Spelling_Of (Tok_Constant))
+ then
+ null;
+ end if;
+ end;
+ end if;
+
+ -- We allow "constant" here (as in "return Result : constant
+ -- T..."). This is not in the latest RM, but the ARG is considering an
+ -- AI on the subject (see AI05-0015-1), which we expect to be approved.
+
+ if Token = Tok_Constant then
+ Scan; -- past CONSTANT
+ Set_Constant_Present (Decl_Node);
+
+ if Token = Tok_Aliased then
+ Error_Msg_SC -- CODEFIX
+ ("ALIASED should be before CONSTANT");
+ Scan; -- past ALIASED
+ Set_Aliased_Present (Decl_Node);
+ end if;
+
+ elsif Token = Tok_Aliased then
+ Scan; -- past ALIASED
+ Set_Aliased_Present (Decl_Node);
+
+ -- The restrictions on the use of aliased in an extended return
+ -- are semantic, not syntactic.
+
+ if Token = Tok_Constant then
+ Scan; -- past CONSTANT
+ Set_Constant_Present (Decl_Node);
+ end if;
+ end if;
+
+ P_Return_Subtype_Indication (Decl_Node);
+
+ if Token = Tok_Colon_Equal then
+ Scan; -- past :=
+ Set_Expression (Decl_Node, P_Expression_No_Right_Paren);
+ Set_Has_Init_Expression (Decl_Node);
+ end if;
+
+ return Decl_Node;
+ end P_Return_Object_Declaration;
+
+ -- Error recovery: can raise Error_Resync
+
+ function P_Return_Statement return Node_Id is
+ -- The caller has checked that the initial token is RETURN
+
+ type Return_Kind is (Simple_Return, Extended_Return, Return_When);
+
+ function Get_Return_Kind return Return_Kind;
+ -- Scan state is just after RETURN (and is left that way). Determine
+ -- whether this is a simple or extended return statement by looking
+ -- ahead for "identifier :", which implies extended.
- -- Sloc points to RETURN
- -- Expression (Op3)
+ ---------------------
+ -- Get_Return_Kind --
+ ---------------------
+ function Get_Return_Kind return Return_Kind is
+ Scan_State : Saved_Scan_State;
+ Result : Return_Kind := Simple_Return;
+
+ begin
+ if Token = Tok_Identifier then
+ Save_Scan_State (Scan_State); -- at identifier
+ Scan; -- past identifier
+
+ if Token = Tok_Colon then
+ Result := Extended_Return; -- It's an extended_return_statement
+ elsif Token = Tok_When then
+ Error_Msg_GNAT_Extension ("return when statement");
+
+ Result := Return_When;
+ end if;
+
+ Restore_Scan_State (Scan_State); -- to identifier
+
+ elsif Token = Tok_When then
+ Error_Msg_GNAT_Extension ("return when statement");
+
+ Result := Return_When;
+ end if;
+
+ return Result;
+ end Get_Return_Kind;
+
+ Ret_Sloc : constant Source_Ptr := Token_Ptr;
+ Ret_Strt : constant Column_Number := Start_Column;
+ Ret_Node : Node_Id := New_Node (N_Simple_Return_Statement, Ret_Sloc);
+ Decl : Node_Id;
+
+ -- Start of processing for P_Return_Statement
+
+ begin
Scan; -- past RETURN
- if Token /= Tok_Semicolon then
+ -- Simple_return_statement, no expression, return an
+ -- N_Simple_Return_Statement node with the expression field left Empty.
+
+ if Token = Tok_Semicolon then
+ Scan; -- past ;
+
+ -- Nontrivial case
+
+ else
+ -- Simple_return_statement with expression
- -- If no semicolon, then scan an expression, except that
- -- we avoid trying to scan an expression if we are at an
+ -- We avoid trying to scan an expression if we are at an
-- expression terminator since in that case the best error
-- message is probably that we have a missing semicolon.
- if Token not in Token_Class_Eterm then
- Set_Expression (Return_Node, P_Expression_No_Right_Paren);
- end if;
+ case Get_Return_Kind is
+ -- Return_when_statement (Experimental only)
+
+ when Return_When =>
+ Ret_Node := New_Node (N_Return_When_Statement, Ret_Sloc);
+
+ if Token not in Token_Class_Eterm then
+ Set_Expression (Ret_Node, P_Expression_No_Right_Paren);
+ end if;
+
+ if Token = Tok_When and then not Missing_Semicolon_On_When then
+ Scan; -- past WHEN
+ Set_Condition (Ret_Node, P_Condition);
+
+ -- Allow IF instead of WHEN, giving error message
+
+ elsif Token = Tok_If then
+ T_When;
+ Scan; -- past IF used in place of WHEN
+ Set_Condition (Ret_Node, P_Expression_No_Right_Paren);
+ end if;
+
+ -- Simple_return_statement
+
+ when Simple_Return =>
+ Ret_Node := New_Node (N_Simple_Return_Statement, Ret_Sloc);
+
+ if Token not in Token_Class_Eterm then
+ Set_Expression (Ret_Node, P_Expression_No_Right_Paren);
+ end if;
+
+ -- Extended_return_statement (Ada 2005 only -- AI-318):
+
+ when Extended_Return =>
+ Error_Msg_Ada_2005_Extension ("extended return statement");
+
+ Ret_Node := New_Node (N_Extended_Return_Statement, Ret_Sloc);
+ Decl := P_Return_Object_Declaration;
+ Set_Return_Object_Declarations (Ret_Node, New_List (Decl));
+
+ if Token = Tok_With then
+ P_Aspect_Specifications (Decl, False);
+ end if;
+
+ if Token = Tok_Do then
+ Push_Scope_Stack;
+ Scopes (Scope.Last).Ecol := Ret_Strt;
+ Scopes (Scope.Last).Etyp := E_Return;
+ Scopes (Scope.Last).Labl := Error;
+ Scopes (Scope.Last).Sloc := Ret_Sloc;
+
+ Scan; -- past DO
+ Set_Handled_Statement_Sequence
+ (Ret_Node, P_Handled_Sequence_Of_Statements);
+ End_Statements;
+
+ -- Do we need to handle Error_Resync here???
+ end if;
+ end case;
+
+ TF_Semicolon;
end if;
- TF_Semicolon;
- return Return_Node;
+ return Ret_Node;
end P_Return_Statement;
end Ch6;
projects / thirdparty / gcc.git / blobdiff