1560 lines
51 KiB
Ada
1560 lines
51 KiB
Ada
------------------------------------------------------------------------------
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-- --
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-- GNAT COMPILER COMPONENTS --
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-- --
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-- P A R . C H 6 --
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-- --
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-- B o d y --
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-- --
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-- Copyright (C) 1992-2009, Free Software Foundation, Inc. --
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-- --
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-- GNAT is free software; you can redistribute it and/or modify it under --
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-- terms of the GNU General Public License as published by the Free Soft- --
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-- ware Foundation; either version 3, or (at your option) any later ver- --
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-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
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-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
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-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
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-- for more details. You should have received a copy of the GNU General --
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-- Public License distributed with GNAT; see file COPYING3. If not, go to --
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-- http://www.gnu.org/licenses for a complete copy of the license. --
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-- --
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-- GNAT was originally developed by the GNAT team at New York University. --
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-- Extensive contributions were provided by Ada Core Technologies Inc. --
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-- --
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------------------------------------------------------------------------------
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pragma Style_Checks (All_Checks);
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-- Turn off subprogram body ordering check. Subprograms are in order
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-- by RM section rather than alphabetical
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with Sinfo.CN; use Sinfo.CN;
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separate (Par)
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package body Ch6 is
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-- Local subprograms, used only in this chapter
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function P_Defining_Designator return Node_Id;
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function P_Defining_Operator_Symbol return Node_Id;
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function P_Return_Object_Declaration return Node_Id;
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procedure P_Return_Subtype_Indication (Decl_Node : Node_Id);
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-- Decl_Node is a N_Object_Declaration.
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-- Set the Null_Exclusion_Present and Object_Definition fields of
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-- Decl_Node.
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procedure Check_Junk_Semicolon_Before_Return;
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-- Check for common error of junk semicolon before RETURN keyword of
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-- function specification. If present, skip over it with appropriate
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-- error message, leaving Scan_Ptr pointing to the RETURN after. This
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-- routine also deals with a possibly misspelled version of Return.
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----------------------------------------
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-- Check_Junk_Semicolon_Before_Return --
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----------------------------------------
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procedure Check_Junk_Semicolon_Before_Return is
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Scan_State : Saved_Scan_State;
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begin
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if Token = Tok_Semicolon then
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Save_Scan_State (Scan_State);
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Scan; -- past the semicolon
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if Token = Tok_Return then
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Restore_Scan_State (Scan_State);
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Error_Msg_SC ("|extra "";"" ignored");
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Scan; -- rescan past junk semicolon
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else
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Restore_Scan_State (Scan_State);
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end if;
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elsif Bad_Spelling_Of (Tok_Return) then
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null;
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end if;
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end Check_Junk_Semicolon_Before_Return;
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-----------------------------------------------------
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-- 6.1 Subprogram (Also 6.3, 8.5.4, 10.1.3, 12.3) --
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-----------------------------------------------------
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-- This routine scans out a subprogram declaration, subprogram body,
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-- subprogram renaming declaration or subprogram generic instantiation.
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-- SUBPROGRAM_DECLARATION ::= SUBPROGRAM_SPECIFICATION;
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-- ABSTRACT_SUBPROGRAM_DECLARATION ::=
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-- SUBPROGRAM_SPECIFICATION is abstract;
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-- SUBPROGRAM_SPECIFICATION ::=
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-- procedure DEFINING_PROGRAM_UNIT_NAME PARAMETER_PROFILE
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-- | function DEFINING_DESIGNATOR PARAMETER_AND_RESULT_PROFILE
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-- PARAMETER_PROFILE ::= [FORMAL_PART]
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-- PARAMETER_AND_RESULT_PROFILE ::= [FORMAL_PART] return SUBTYPE_MARK
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-- SUBPROGRAM_BODY ::=
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-- SUBPROGRAM_SPECIFICATION is
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-- DECLARATIVE_PART
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-- begin
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-- HANDLED_SEQUENCE_OF_STATEMENTS
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-- end [DESIGNATOR];
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-- SUBPROGRAM_RENAMING_DECLARATION ::=
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-- SUBPROGRAM_SPECIFICATION renames callable_entity_NAME;
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-- SUBPROGRAM_BODY_STUB ::=
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-- SUBPROGRAM_SPECIFICATION is separate;
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-- GENERIC_INSTANTIATION ::=
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-- procedure DEFINING_PROGRAM_UNIT_NAME is
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-- new generic_procedure_NAME [GENERIC_ACTUAL_PART];
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-- | function DEFINING_DESIGNATOR is
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-- new generic_function_NAME [GENERIC_ACTUAL_PART];
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-- NULL_PROCEDURE_DECLARATION ::=
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-- SUBPROGRAM_SPECIFICATION is null;
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-- Null procedures are an Ada 2005 feature. A null procedure declaration
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-- is classified as a basic declarative item, but it is parsed here, with
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-- other subprogram constructs.
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-- The value in Pf_Flags indicates which of these possible declarations
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-- is acceptable to the caller:
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-- Pf_Flags.Decl Set if declaration OK
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-- Pf_Flags.Gins Set if generic instantiation OK
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-- Pf_Flags.Pbod Set if proper body OK
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-- Pf_Flags.Rnam Set if renaming declaration OK
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-- Pf_Flags.Stub Set if body stub OK
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-- If an inappropriate form is encountered, it is scanned out but an
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-- error message indicating that it is appearing in an inappropriate
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-- context is issued. The only possible values for Pf_Flags are those
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-- defined as constants in the Par package.
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-- The caller has checked that the initial token is FUNCTION, PROCEDURE,
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-- NOT or OVERRIDING.
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-- Error recovery: cannot raise Error_Resync
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function P_Subprogram (Pf_Flags : Pf_Rec) return Node_Id is
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Specification_Node : Node_Id;
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Name_Node : Node_Id;
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Fpart_List : List_Id;
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Fpart_Sloc : Source_Ptr;
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Result_Not_Null : Boolean := False;
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Result_Node : Node_Id;
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Inst_Node : Node_Id;
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Body_Node : Node_Id;
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Decl_Node : Node_Id;
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Rename_Node : Node_Id;
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Absdec_Node : Node_Id;
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Stub_Node : Node_Id;
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Fproc_Sloc : Source_Ptr;
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Func : Boolean;
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Scan_State : Saved_Scan_State;
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-- Flags for optional overriding indication. Two flags are needed,
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-- to distinguish positive and negative overriding indicators from
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-- the absence of any indicator.
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Is_Overriding : Boolean := False;
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Not_Overriding : Boolean := False;
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begin
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-- Set up scope stack entry. Note that the Labl field will be set later
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SIS_Entry_Active := False;
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SIS_Missing_Semicolon_Message := No_Error_Msg;
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Push_Scope_Stack;
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Scope.Table (Scope.Last).Sloc := Token_Ptr;
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Scope.Table (Scope.Last).Etyp := E_Name;
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Scope.Table (Scope.Last).Ecol := Start_Column;
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Scope.Table (Scope.Last).Lreq := False;
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-- Ada2005: scan leading NOT OVERRIDING indicator
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if Token = Tok_Not then
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Scan; -- past NOT
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if Token = Tok_Overriding then
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Scan; -- past OVERRIDING
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Not_Overriding := True;
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-- Overriding keyword used in non Ada 2005 mode
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elsif Token = Tok_Identifier
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and then Token_Name = Name_Overriding
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then
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Error_Msg_SC ("overriding indicator is an Ada 2005 extension");
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Error_Msg_SC ("\unit must be compiled with -gnat05 switch");
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Scan; -- past Overriding
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Not_Overriding := True;
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else
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Error_Msg_SC ("OVERRIDING expected!");
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end if;
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-- Ada 2005: scan leading OVERRIDING indicator
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-- Note: in the case of OVERRIDING keyword used in Ada 95 mode, the
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-- declaration circuit already gave an error message and changed the
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-- token to Tok_Overriding.
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elsif Token = Tok_Overriding then
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Scan; -- past OVERRIDING
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Is_Overriding := True;
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end if;
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if (Is_Overriding or else Not_Overriding) then
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-- Note that if we are not in Ada_05 mode, error messages have
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-- already been given, so no need to give another message here.
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-- An overriding indicator is allowed for subprogram declarations,
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-- bodies, renamings, stubs, and instantiations. The test against
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-- Pf_Decl_Pbod is added to account for the case of subprograms
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-- declared in a protected type, where only subprogram declarations
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-- and bodies can occur.
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if Pf_Flags /= Pf_Decl_Gins_Pbod_Rnam_Stub
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and then
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Pf_Flags /= Pf_Decl_Pbod
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then
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Error_Msg_SC ("overriding indicator not allowed here!");
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elsif Token /= Tok_Function and then Token /= Tok_Procedure then
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Error_Msg_SC -- CODEFIX
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("FUNCTION or PROCEDURE expected!");
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end if;
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end if;
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Func := (Token = Tok_Function);
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Fproc_Sloc := Token_Ptr;
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Scan; -- past FUNCTION or PROCEDURE
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Ignore (Tok_Type);
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Ignore (Tok_Body);
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if Func then
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Name_Node := P_Defining_Designator;
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if Nkind (Name_Node) = N_Defining_Operator_Symbol
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and then Scope.Last = 1
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then
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Error_Msg_SP ("operator symbol not allowed at library level");
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Name_Node := New_Entity (N_Defining_Identifier, Sloc (Name_Node));
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-- Set name from file name, we need some junk name, and that's
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-- as good as anything. This is only approximate, since we do
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-- not do anything with non-standard name translations.
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Get_Name_String (File_Name (Current_Source_File));
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for J in 1 .. Name_Len loop
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if Name_Buffer (J) = '.' then
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Name_Len := J - 1;
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exit;
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end if;
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end loop;
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Set_Chars (Name_Node, Name_Find);
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Set_Error_Posted (Name_Node);
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end if;
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else
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Name_Node := P_Defining_Program_Unit_Name;
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end if;
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Scope.Table (Scope.Last).Labl := Name_Node;
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Ignore (Tok_Colon);
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-- Deal with generic instantiation, the one case in which we do not
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-- have a subprogram specification as part of whatever we are parsing
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if Token = Tok_Is then
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Save_Scan_State (Scan_State); -- at the IS
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T_Is; -- checks for redundant IS
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if Token = Tok_New then
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if not Pf_Flags.Gins then
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Error_Msg_SC ("generic instantiation not allowed here!");
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end if;
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Scan; -- past NEW
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if Func then
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Inst_Node := New_Node (N_Function_Instantiation, Fproc_Sloc);
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Set_Name (Inst_Node, P_Function_Name);
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else
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Inst_Node := New_Node (N_Procedure_Instantiation, Fproc_Sloc);
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Set_Name (Inst_Node, P_Qualified_Simple_Name);
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end if;
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Set_Defining_Unit_Name (Inst_Node, Name_Node);
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Set_Generic_Associations (Inst_Node, P_Generic_Actual_Part_Opt);
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TF_Semicolon;
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Pop_Scope_Stack; -- Don't need scope stack entry in this case
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if Is_Overriding then
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Set_Must_Override (Inst_Node);
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elsif Not_Overriding then
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Set_Must_Not_Override (Inst_Node);
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end if;
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return Inst_Node;
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else
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Restore_Scan_State (Scan_State); -- to the IS
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end if;
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end if;
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-- If not a generic instantiation, then we definitely have a subprogram
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-- specification (all possibilities at this stage include one here)
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Fpart_Sloc := Token_Ptr;
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Check_Misspelling_Of (Tok_Return);
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-- Scan formal part. First a special error check. If we have an
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-- identifier here, then we have a definite error. If this identifier
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-- is on the same line as the designator, then we assume it is the
|
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-- first formal after a missing left parenthesis
|
|
|
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if Token = Tok_Identifier
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and then not Token_Is_At_Start_Of_Line
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then
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T_Left_Paren; -- to generate message
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Fpart_List := P_Formal_Part;
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-- Otherwise scan out an optional formal part in the usual manner
|
|
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else
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Fpart_List := P_Parameter_Profile;
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end if;
|
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|
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-- We treat what we have as a function specification if FUNCTION was
|
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-- used, or if a RETURN is present. This gives better error recovery
|
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-- since later RETURN statements will be valid in either case.
|
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Check_Junk_Semicolon_Before_Return;
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Result_Node := Error;
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if Token = Tok_Return then
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if not Func then
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Error_Msg ("PROCEDURE should be FUNCTION", Fproc_Sloc);
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Func := True;
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end if;
|
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Scan; -- past RETURN
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Result_Not_Null := P_Null_Exclusion; -- Ada 2005 (AI-231)
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|
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-- Ada 2005 (AI-318-02)
|
|
|
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if Token = Tok_Access then
|
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if Ada_Version < Ada_05 then
|
|
Error_Msg_SC
|
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("anonymous access result type is an Ada 2005 extension");
|
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Error_Msg_SC ("\unit must be compiled with -gnat05 switch");
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end if;
|
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Result_Node := P_Access_Definition (Result_Not_Null);
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else
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Result_Node := P_Subtype_Mark;
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No_Constraint;
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end if;
|
|
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else
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if Func then
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Ignore (Tok_Right_Paren);
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TF_Return;
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end if;
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end if;
|
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if Func then
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Specification_Node :=
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New_Node (N_Function_Specification, Fproc_Sloc);
|
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Set_Null_Exclusion_Present (Specification_Node, Result_Not_Null);
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Set_Result_Definition (Specification_Node, Result_Node);
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else
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Specification_Node :=
|
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New_Node (N_Procedure_Specification, Fproc_Sloc);
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end if;
|
|
|
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Set_Defining_Unit_Name (Specification_Node, Name_Node);
|
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Set_Parameter_Specifications (Specification_Node, Fpart_List);
|
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|
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if Is_Overriding then
|
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Set_Must_Override (Specification_Node);
|
|
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elsif Not_Overriding then
|
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Set_Must_Not_Override (Specification_Node);
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end if;
|
|
|
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-- Error check: barriers not allowed on protected functions/procedures
|
|
|
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if Token = Tok_When then
|
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if Func then
|
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Error_Msg_SC ("barrier not allowed on function, only on entry");
|
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else
|
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Error_Msg_SC ("barrier not allowed on procedure, only on entry");
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end if;
|
|
|
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Scan; -- past WHEN
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Discard_Junk_Node (P_Expression);
|
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end if;
|
|
|
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-- Deal with semicolon followed by IS. We want to treat this as IS
|
|
|
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if Token = Tok_Semicolon then
|
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Save_Scan_State (Scan_State);
|
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Scan; -- past semicolon
|
|
|
|
if Token = Tok_Is then
|
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Error_Msg_SP ("extra "";"" ignored");
|
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else
|
|
Restore_Scan_State (Scan_State);
|
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end if;
|
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end if;
|
|
|
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-- Deal with case of semicolon ending a subprogram declaration
|
|
|
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if Token = Tok_Semicolon then
|
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if not Pf_Flags.Decl then
|
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T_Is;
|
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end if;
|
|
|
|
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 ("|extra "";"" ignored");
|
|
T_Is; -- scan past IS
|
|
goto Subprogram_Body;
|
|
|
|
-- If BEGIN follows in an appropriate column, we immediately
|
|
-- commence the error action of assuming that the previous
|
|
-- subprogram declaration should have been a subprogram body,
|
|
-- i.e. that the terminating semicolon should have been IS.
|
|
|
|
elsif Token = Tok_Begin
|
|
and then Start_Column >= Scope.Table (Scope.Last).Ecol
|
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then
|
|
Error_Msg_SP ("|"";"" should be IS!");
|
|
goto Subprogram_Body;
|
|
|
|
else
|
|
goto Subprogram_Declaration;
|
|
end if;
|
|
|
|
-- Case of not followed by semicolon
|
|
|
|
else
|
|
-- Subprogram renaming declaration case
|
|
|
|
Check_Misspelling_Of (Tok_Renames);
|
|
|
|
if Token = Tok_Renames then
|
|
if not Pf_Flags.Rnam then
|
|
Error_Msg_SC ("renaming declaration not allowed here!");
|
|
end if;
|
|
|
|
Rename_Node :=
|
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New_Node (N_Subprogram_Renaming_Declaration, Token_Ptr);
|
|
Scan; -- past RENAMES
|
|
Set_Name (Rename_Node, P_Name);
|
|
Set_Specification (Rename_Node, Specification_Node);
|
|
TF_Semicolon;
|
|
Pop_Scope_Stack;
|
|
return Rename_Node;
|
|
|
|
-- Case of IS following subprogram specification
|
|
|
|
elsif Token = Tok_Is then
|
|
T_Is; -- ignore redundant Is's
|
|
|
|
if Token_Name = Name_Abstract then
|
|
Check_95_Keyword (Tok_Abstract, Tok_Semicolon);
|
|
end if;
|
|
|
|
-- Deal nicely with (now obsolete) use of <> in place of abstract
|
|
|
|
if Token = Tok_Box then
|
|
Error_Msg_SC ("ABSTRACT expected");
|
|
Token := Tok_Abstract;
|
|
end if;
|
|
|
|
-- Abstract subprogram declaration case
|
|
|
|
if Token = Tok_Abstract then
|
|
Absdec_Node :=
|
|
New_Node (N_Abstract_Subprogram_Declaration, Token_Ptr);
|
|
Set_Specification (Absdec_Node, Specification_Node);
|
|
Pop_Scope_Stack; -- discard unneeded entry
|
|
Scan; -- past ABSTRACT
|
|
TF_Semicolon;
|
|
return Absdec_Node;
|
|
|
|
-- Ada 2005 (AI-248): Parse a null procedure declaration
|
|
|
|
elsif Token = Tok_Null then
|
|
if Ada_Version < Ada_05 then
|
|
Error_Msg_SP ("null procedures are an Ada 2005 extension");
|
|
Error_Msg_SP ("\unit must be compiled with -gnat05 switch");
|
|
end if;
|
|
|
|
Scan; -- past NULL
|
|
|
|
if Func then
|
|
Error_Msg_SP ("only procedures can be null");
|
|
else
|
|
Set_Null_Present (Specification_Node);
|
|
end if;
|
|
|
|
TF_Semicolon;
|
|
goto Subprogram_Declaration;
|
|
|
|
-- Check for IS NEW with Formal_Part present and handle nicely
|
|
|
|
elsif Token = Tok_New then
|
|
Error_Msg
|
|
("formal part not allowed in instantiation", Fpart_Sloc);
|
|
Scan; -- past NEW
|
|
|
|
if Func then
|
|
Inst_Node := New_Node (N_Function_Instantiation, Fproc_Sloc);
|
|
else
|
|
Inst_Node :=
|
|
New_Node (N_Procedure_Instantiation, Fproc_Sloc);
|
|
end if;
|
|
|
|
Set_Defining_Unit_Name (Inst_Node, Name_Node);
|
|
Set_Name (Inst_Node, P_Name);
|
|
Set_Generic_Associations (Inst_Node, P_Generic_Actual_Part_Opt);
|
|
TF_Semicolon;
|
|
Pop_Scope_Stack; -- Don't need scope stack entry in this case
|
|
return Inst_Node;
|
|
|
|
else
|
|
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
|
|
|
|
else
|
|
Error_Msg_AP ("|missing "";""");
|
|
SIS_Missing_Semicolon_Message := Get_Msg_Id;
|
|
goto Subprogram_Declaration;
|
|
end if;
|
|
end if;
|
|
|
|
-- Processing for subprogram body
|
|
|
|
<<Subprogram_Body>>
|
|
if not Pf_Flags.Pbod then
|
|
Error_Msg_SP ("subprogram body not allowed here!");
|
|
end if;
|
|
|
|
-- Subprogram body stub case
|
|
|
|
if Separate_Present then
|
|
if not Pf_Flags.Stub then
|
|
Error_Msg_SC ("body stub not allowed here!");
|
|
end if;
|
|
|
|
if Nkind (Name_Node) = N_Defining_Operator_Symbol then
|
|
Error_Msg
|
|
("operator symbol cannot be used as subunit name",
|
|
Sloc (Name_Node));
|
|
end if;
|
|
|
|
Stub_Node :=
|
|
New_Node (N_Subprogram_Body_Stub, Sloc (Specification_Node));
|
|
Set_Specification (Stub_Node, Specification_Node);
|
|
Scan; -- past SEPARATE
|
|
Pop_Scope_Stack;
|
|
TF_Semicolon;
|
|
return Stub_Node;
|
|
|
|
-- Subprogram body 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;
|
|
|
|
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;
|
|
end if;
|
|
|
|
-- Processing for subprogram declaration
|
|
|
|
<<Subprogram_Declaration>>
|
|
Decl_Node :=
|
|
New_Node (N_Subprogram_Declaration, Sloc (Specification_Node));
|
|
Set_Specification (Decl_Node, Specification_Node);
|
|
|
|
-- 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;
|
|
SIS_Declaration_Node := Decl_Node;
|
|
SIS_Semicolon_Sloc := Prev_Token_Ptr;
|
|
SIS_Entry_Active := True;
|
|
end if;
|
|
|
|
Pop_Scope_Stack;
|
|
return Decl_Node;
|
|
|
|
end P_Subprogram;
|
|
|
|
---------------------------------
|
|
-- 6.1 Subprogram Declaration --
|
|
---------------------------------
|
|
|
|
-- Parsed by P_Subprogram (6.1)
|
|
|
|
------------------------------------------
|
|
-- 6.1 Abstract Subprogram Declaration --
|
|
------------------------------------------
|
|
|
|
-- Parsed by P_Subprogram (6.1)
|
|
|
|
-----------------------------------
|
|
-- 6.1 Subprogram Specification --
|
|
-----------------------------------
|
|
|
|
-- SUBPROGRAM_SPECIFICATION ::=
|
|
-- procedure DEFINING_PROGRAM_UNIT_NAME PARAMETER_PROFILE
|
|
-- | function DEFINING_DESIGNATOR PARAMETER_AND_RESULT_PROFILE
|
|
|
|
-- PARAMETER_PROFILE ::= [FORMAL_PART]
|
|
|
|
-- PARAMETER_AND_RESULT_PROFILE ::= [FORMAL_PART] return SUBTYPE_MARK
|
|
|
|
-- Subprogram specifications that appear in subprogram declarations
|
|
-- are parsed by P_Subprogram (6.1). This routine is used in other
|
|
-- contexts where subprogram specifications occur.
|
|
|
|
-- Note: this routine does not affect the scope stack in any way
|
|
|
|
-- Error recovery: can raise Error_Resync
|
|
|
|
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 := New_Node (N_Function_Specification, Token_Ptr);
|
|
Scan; -- past FUNCTION
|
|
Ignore (Tok_Body);
|
|
Set_Defining_Unit_Name (Specification_Node, P_Defining_Designator);
|
|
Set_Parameter_Specifications
|
|
(Specification_Node, P_Parameter_Profile);
|
|
Check_Junk_Semicolon_Before_Return;
|
|
TF_Return;
|
|
|
|
Result_Not_Null := P_Null_Exclusion; -- Ada 2005 (AI-231)
|
|
|
|
-- Ada 2005 (AI-318-02)
|
|
|
|
if Token = Tok_Access then
|
|
if Ada_Version < Ada_05 then
|
|
Error_Msg_SC
|
|
("anonymous access result type is an Ada 2005 extension");
|
|
Error_Msg_SC ("\unit must be compiled with -gnat05 switch");
|
|
end if;
|
|
|
|
Result_Node := P_Access_Definition (Result_Not_Null);
|
|
|
|
else
|
|
Result_Node := P_Subtype_Mark;
|
|
No_Constraint;
|
|
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
|
|
Specification_Node := New_Node (N_Procedure_Specification, Token_Ptr);
|
|
Scan; -- past PROCEDURE
|
|
Ignore (Tok_Body);
|
|
Set_Defining_Unit_Name
|
|
(Specification_Node, P_Defining_Program_Unit_Name);
|
|
Set_Parameter_Specifications
|
|
(Specification_Node, P_Parameter_Profile);
|
|
return Specification_Node;
|
|
|
|
else
|
|
Error_Msg_SC ("subprogram specification expected");
|
|
raise Error_Resync;
|
|
end if;
|
|
end P_Subprogram_Specification;
|
|
|
|
---------------------
|
|
-- 6.1 Designator --
|
|
---------------------
|
|
|
|
-- DESIGNATOR ::=
|
|
-- [PARENT_UNIT_NAME .] IDENTIFIER | OPERATOR_SYMBOL
|
|
|
|
-- The caller has checked that the initial token is an identifier,
|
|
-- operator symbol, or string literal. Note that we don't bother to
|
|
-- do much error diagnosis in this routine, since it is only used for
|
|
-- the label on END lines, and the routines in package Par.Endh will
|
|
-- check that the label is appropriate.
|
|
|
|
-- Error recovery: cannot raise Error_Resync
|
|
|
|
function P_Designator return Node_Id is
|
|
Ident_Node : Node_Id;
|
|
Name_Node : Node_Id;
|
|
Prefix_Node : Node_Id;
|
|
|
|
function Real_Dot return Boolean;
|
|
-- Tests if a current token is an interesting period, i.e. is followed
|
|
-- by an identifier or operator symbol or string literal. If not, it is
|
|
-- probably just incorrect punctuation to be caught by our caller. Note
|
|
-- that the case of an operator symbol or string literal is also an
|
|
-- error, but that is an error that we catch here. If the result is
|
|
-- 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;
|
|
|
|
begin
|
|
if Token /= Tok_Dot then
|
|
return False;
|
|
|
|
else
|
|
Save_Scan_State (Scan_State);
|
|
Scan; -- past dot
|
|
|
|
if Token = Tok_Identifier
|
|
or else Token = Tok_Operator_Symbol
|
|
or else Token = Tok_String_Literal
|
|
then
|
|
return True;
|
|
|
|
else
|
|
Restore_Scan_State (Scan_State);
|
|
return False;
|
|
end if;
|
|
end if;
|
|
end Real_Dot;
|
|
|
|
-- Start of processing for P_Designator
|
|
|
|
begin
|
|
Ident_Node := Token_Node;
|
|
Scan; -- past initial token
|
|
|
|
if Prev_Token = Tok_Operator_Symbol
|
|
or else Prev_Token = Tok_String_Literal
|
|
or else not Real_Dot
|
|
then
|
|
return Ident_Node;
|
|
|
|
-- Child name case
|
|
|
|
else
|
|
Prefix_Node := Ident_Node;
|
|
|
|
-- Loop through child names, on entry to this loop, Prefix contains
|
|
-- the name scanned so far, and Ident_Node is the last identifier.
|
|
|
|
loop
|
|
Name_Node := New_Node (N_Selected_Component, Prev_Token_Ptr);
|
|
Set_Prefix (Name_Node, Prefix_Node);
|
|
Ident_Node := P_Identifier;
|
|
Set_Selector_Name (Name_Node, Ident_Node);
|
|
Prefix_Node := Name_Node;
|
|
exit when not Real_Dot;
|
|
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.
|
|
|
|
Name_Node := Prefix (Prefix_Node);
|
|
Change_Node (Prefix_Node, N_Designator);
|
|
Set_Name (Prefix_Node, Name_Node);
|
|
Set_Identifier (Prefix_Node, Ident_Node);
|
|
return Prefix_Node;
|
|
end if;
|
|
|
|
exception
|
|
when Error_Resync =>
|
|
while Token = Tok_Dot or else Token = Tok_Identifier loop
|
|
Scan;
|
|
end loop;
|
|
|
|
return Error;
|
|
end P_Designator;
|
|
|
|
------------------------------
|
|
-- 6.1 Defining Designator --
|
|
------------------------------
|
|
|
|
-- DEFINING_DESIGNATOR ::=
|
|
-- DEFINING_PROGRAM_UNIT_NAME | DEFINING_OPERATOR_SYMBOL
|
|
|
|
-- Error recovery: cannot raise Error_Resync
|
|
|
|
function P_Defining_Designator return Node_Id is
|
|
begin
|
|
if Token = Tok_Operator_Symbol then
|
|
return P_Defining_Operator_Symbol;
|
|
|
|
elsif Token = Tok_String_Literal then
|
|
Error_Msg_SC ("invalid operator name");
|
|
Scan; -- past junk string
|
|
return Error;
|
|
|
|
else
|
|
return P_Defining_Program_Unit_Name;
|
|
end if;
|
|
end P_Defining_Designator;
|
|
|
|
-------------------------------------
|
|
-- 6.1 Defining Program Unit Name --
|
|
-------------------------------------
|
|
|
|
-- DEFINING_PROGRAM_UNIT_NAME ::=
|
|
-- [PARENT_UNIT_NAME .] DEFINING_IDENTIFIER
|
|
|
|
-- Note: PARENT_UNIT_NAME may be present only in 95 mode at the outer level
|
|
|
|
-- Error recovery: cannot raise Error_Resync
|
|
|
|
function P_Defining_Program_Unit_Name return Node_Id is
|
|
Ident_Node : Node_Id;
|
|
Name_Node : Node_Id;
|
|
Prefix_Node : Node_Id;
|
|
|
|
begin
|
|
-- Set identifier casing if not already set and scan initial identifier
|
|
|
|
if Token = Tok_Identifier
|
|
and then Identifier_Casing (Current_Source_File) = Unknown
|
|
then
|
|
Set_Identifier_Casing (Current_Source_File, Determine_Token_Casing);
|
|
end if;
|
|
|
|
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);
|
|
return Ident_Node;
|
|
|
|
-- Child library unit name case
|
|
|
|
else
|
|
if Scope.Last > 1 then
|
|
Error_Msg_SP ("child unit allowed only at library level");
|
|
raise Error_Resync;
|
|
|
|
elsif Ada_Version = Ada_83 then
|
|
Error_Msg_SP ("(Ada 83) child unit not allowed!");
|
|
|
|
end if;
|
|
|
|
Prefix_Node := Ident_Node;
|
|
|
|
-- Loop through child names, on entry to this loop, Prefix contains
|
|
-- the name scanned so far, and Ident_Node is the last identifier.
|
|
|
|
loop
|
|
exit when Token /= Tok_Dot;
|
|
Name_Node := New_Node (N_Selected_Component, Token_Ptr);
|
|
Scan; -- past period
|
|
Set_Prefix (Name_Node, Prefix_Node);
|
|
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.
|
|
|
|
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);
|
|
Set_Defining_Identifier (Prefix_Node, Ident_Node);
|
|
|
|
-- All set with unit name parsed
|
|
|
|
return Prefix_Node;
|
|
end if;
|
|
|
|
exception
|
|
when Error_Resync =>
|
|
while Token = Tok_Dot or else Token = Tok_Identifier loop
|
|
Scan;
|
|
end loop;
|
|
|
|
return Error;
|
|
end P_Defining_Program_Unit_Name;
|
|
|
|
--------------------------
|
|
-- 6.1 Operator Symbol --
|
|
--------------------------
|
|
|
|
-- OPERATOR_SYMBOL ::= STRING_LITERAL
|
|
|
|
-- Operator symbol is returned by the scanner as Tok_Operator_Symbol
|
|
|
|
-----------------------------------
|
|
-- 6.1 Defining Operator Symbol --
|
|
-----------------------------------
|
|
|
|
-- DEFINING_OPERATOR_SYMBOL ::= OPERATOR_SYMBOL
|
|
|
|
-- The caller has checked that the initial symbol is an operator symbol
|
|
|
|
function P_Defining_Operator_Symbol return Node_Id is
|
|
Op_Node : Node_Id;
|
|
|
|
begin
|
|
Op_Node := Token_Node;
|
|
Change_Operator_Symbol_To_Defining_Operator_Symbol (Op_Node);
|
|
Scan; -- past operator symbol
|
|
return Op_Node;
|
|
end P_Defining_Operator_Symbol;
|
|
|
|
----------------------------
|
|
-- 6.1 Parameter_Profile --
|
|
----------------------------
|
|
|
|
-- PARAMETER_PROFILE ::= [FORMAL_PART]
|
|
|
|
-- Empty is returned if no formal part is present
|
|
|
|
-- Error recovery: cannot raise Error_Resync
|
|
|
|
function P_Parameter_Profile return List_Id is
|
|
begin
|
|
if Token = Tok_Left_Paren then
|
|
Scan; -- part left paren
|
|
return P_Formal_Part;
|
|
else
|
|
return No_List;
|
|
end if;
|
|
end P_Parameter_Profile;
|
|
|
|
---------------------------------------
|
|
-- 6.1 Parameter And Result Profile --
|
|
---------------------------------------
|
|
|
|
-- Parsed by its parent construct, which uses P_Parameter_Profile to
|
|
-- parse the parameters, and P_Subtype_Mark to parse the return type.
|
|
|
|
----------------------
|
|
-- 6.1 Formal part --
|
|
----------------------
|
|
|
|
-- FORMAL_PART ::= (PARAMETER_SPECIFICATION {; PARAMETER_SPECIFICATION})
|
|
|
|
-- PARAMETER_SPECIFICATION ::=
|
|
-- DEFINING_IDENTIFIER_LIST : MODE [NULL_EXCLUSION] SUBTYPE_MARK
|
|
-- [:= DEFAULT_EXPRESSION]
|
|
-- | DEFINING_IDENTIFIER_LIST : ACCESS_DEFINITION
|
|
-- [:= DEFAULT_EXPRESSION]
|
|
|
|
-- This scans the construct Formal_Part. The caller has already checked
|
|
-- 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.
|
|
|
|
-- Error recovery: cannot raise Error_Resync
|
|
|
|
function P_Formal_Part return List_Id is
|
|
Specification_List : List_Id;
|
|
Specification_Node : Node_Id;
|
|
Scan_State : Saved_Scan_State;
|
|
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
|
|
-- of 4096 is intended to be essentially infinite, and we do not even
|
|
-- bother to check for it being exceeded.
|
|
|
|
begin
|
|
Specification_List := New_List;
|
|
Specification_Loop : loop
|
|
begin
|
|
if Token = Tok_Pragma then
|
|
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 (C_Comma_Colon);
|
|
Num_Idents := 1;
|
|
|
|
Ident_Loop : loop
|
|
exit Ident_Loop when Token = Tok_Colon;
|
|
|
|
-- The only valid tokens are colon and comma, so if we have
|
|
-- neither do a bit of investigation to see which is the
|
|
-- better choice for insertion.
|
|
|
|
if Token /= Tok_Comma then
|
|
|
|
-- Assume colon if IN or OUT keyword found
|
|
|
|
exit Ident_Loop when Token = Tok_In or else Token = Tok_Out;
|
|
|
|
-- Otherwise scan ahead
|
|
|
|
Save_Scan_State (Scan_State);
|
|
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!)
|
|
-- and on a right paren, e.g. Parms (X Y), and also
|
|
-- on an assignment symbol, e.g. Parms (X Y := ..)
|
|
|
|
if Token = Tok_Semicolon
|
|
or else Token = Tok_Right_Paren
|
|
or else Token = Tok_EOF
|
|
or else Token = Tok_Colon_Equal
|
|
then
|
|
Restore_Scan_State (Scan_State);
|
|
exit Ident_Loop;
|
|
|
|
-- If we run into a colon, assume that we had a missing
|
|
-- comma, e.g. Parms (A B : ...). Also assume a missing
|
|
-- comma if we hit another comma, e.g. Parms (A B, C ..)
|
|
|
|
elsif Token = Tok_Colon
|
|
or else Token = Tok_Comma
|
|
then
|
|
Restore_Scan_State (Scan_State);
|
|
exit Look_Ahead;
|
|
end if;
|
|
|
|
Scan;
|
|
end loop Look_Ahead;
|
|
end if;
|
|
|
|
-- Here if a comma is present, or to be assumed
|
|
|
|
T_Comma;
|
|
Num_Idents := Num_Idents + 1;
|
|
Idents (Num_Idents) := P_Defining_Identifier (C_Comma_Colon);
|
|
end loop Ident_Loop;
|
|
|
|
-- Fall through the loop on encountering a colon, or deciding
|
|
-- that there is a missing colon.
|
|
|
|
T_Colon;
|
|
|
|
-- If there are multiple identifiers, we repeatedly scan the
|
|
-- type and initialization expression information by resetting
|
|
-- the scan pointer (so that we get completely separate trees
|
|
-- for each occurrence).
|
|
|
|
if Num_Idents > 1 then
|
|
Save_Scan_State (Scan_State);
|
|
end if;
|
|
|
|
-- Loop through defining identifiers in list
|
|
|
|
Ident := 1;
|
|
|
|
Ident_List_Loop : loop
|
|
Specification_Node :=
|
|
New_Node (N_Parameter_Specification, Ident_Sloc);
|
|
Set_Defining_Identifier (Specification_Node, Idents (Ident));
|
|
|
|
-- 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
|
|
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 (Not_Null_Present));
|
|
|
|
-- Case of IN or OUT present
|
|
|
|
else
|
|
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
|
|
Token = Tok_Function
|
|
then
|
|
Error_Msg_SC ("formal subprogram parameter not allowed");
|
|
Scan;
|
|
|
|
if Token = Tok_Left_Paren then
|
|
Discard_Junk_List (P_Formal_Part);
|
|
end if;
|
|
|
|
if Token = Tok_Return then
|
|
Scan;
|
|
Discard_Junk_Node (P_Subtype_Mark);
|
|
end if;
|
|
|
|
Set_Parameter_Type (Specification_Node, Error);
|
|
|
|
else
|
|
Set_Parameter_Type (Specification_Node, P_Subtype_Mark);
|
|
No_Constraint;
|
|
end if;
|
|
end if;
|
|
|
|
Set_Expression (Specification_Node, Init_Expr_Opt (True));
|
|
|
|
if Ident > 1 then
|
|
Set_Prev_Ids (Specification_Node, True);
|
|
end if;
|
|
|
|
if Ident < Num_Idents then
|
|
Set_More_Ids (Specification_Node, True);
|
|
end if;
|
|
|
|
Append (Specification_Node, Specification_List);
|
|
exit Ident_List_Loop when Ident = Num_Idents;
|
|
Ident := Ident + 1;
|
|
Restore_Scan_State (Scan_State);
|
|
end loop Ident_List_Loop;
|
|
|
|
exception
|
|
when Error_Resync =>
|
|
Resync_Semicolon_List;
|
|
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 ("|"";"" 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 ("missing "")""");
|
|
Restore_Scan_State (Scan_State);
|
|
exit Specification_Loop;
|
|
end if;
|
|
|
|
elsif Token = Tok_Right_Paren then
|
|
Scan; -- past right paren
|
|
exit Specification_Loop;
|
|
|
|
-- 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
|
|
|
|
elsif Token = Tok_Identifier then
|
|
T_Semicolon;
|
|
|
|
-- If nothing sensible, skip to next semicolon or right paren
|
|
|
|
else
|
|
T_Semicolon;
|
|
Resync_Semicolon_List;
|
|
|
|
if Token = Tok_Semicolon then
|
|
Scan; -- past semicolon
|
|
else
|
|
T_Right_Paren;
|
|
exit Specification_Loop;
|
|
end if;
|
|
end if;
|
|
end loop Specification_Loop;
|
|
|
|
return Specification_List;
|
|
end P_Formal_Part;
|
|
|
|
----------------------------------
|
|
-- 6.1 Parameter Specification --
|
|
----------------------------------
|
|
|
|
-- Parsed by P_Formal_Part (6.1)
|
|
|
|
---------------
|
|
-- 6.1 Mode --
|
|
---------------
|
|
|
|
-- MODE ::= [in] | in out | out
|
|
|
|
-- There is no explicit node in the tree for the Mode. Instead the
|
|
-- In_Present and Out_Present flags are set in the parent node to
|
|
-- record the presence of keywords specifying the mode.
|
|
|
|
-- Error_Recovery: cannot raise Error_Resync
|
|
|
|
procedure P_Mode (Node : Node_Id) is
|
|
begin
|
|
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 ("(style) IN should be omitted");
|
|
end if;
|
|
|
|
if Token = Tok_Access then
|
|
Error_Msg_SP ("IN not allowed together with ACCESS");
|
|
Scan; -- past ACCESS
|
|
end if;
|
|
end if;
|
|
|
|
if Token = Tok_Out then
|
|
Scan; -- past OUT
|
|
Set_Out_Present (Node, True);
|
|
end if;
|
|
|
|
if Token = Tok_In then
|
|
Error_Msg_SC -- CODEFIX ???
|
|
("IN must precede OUT in parameter mode");
|
|
Scan; -- past IN
|
|
Set_In_Present (Node, True);
|
|
end if;
|
|
end P_Mode;
|
|
|
|
--------------------------
|
|
-- 6.3 Subprogram Body --
|
|
--------------------------
|
|
|
|
-- Parsed by P_Subprogram (6.1)
|
|
|
|
-----------------------------------
|
|
-- 6.4 Procedure Call Statement --
|
|
-----------------------------------
|
|
|
|
-- Parsed by P_Sequence_Of_Statements (5.1)
|
|
|
|
------------------------
|
|
-- 6.4 Function Call --
|
|
------------------------
|
|
|
|
-- Parsed by P_Call_Or_Name (4.1)
|
|
|
|
--------------------------------
|
|
-- 6.4 Actual Parameter Part --
|
|
--------------------------------
|
|
|
|
-- Parsed by P_Call_Or_Name (4.1)
|
|
|
|
--------------------------------
|
|
-- 6.4 Parameter Association --
|
|
--------------------------------
|
|
|
|
-- Parsed by P_Call_Or_Name (4.1)
|
|
|
|
------------------------------------
|
|
-- 6.4 Explicit Actual Parameter --
|
|
------------------------------------
|
|
|
|
-- Parsed by P_Call_Or_Name (4.1)
|
|
|
|
---------------------------
|
|
-- 6.5 Return Statement --
|
|
---------------------------
|
|
|
|
-- SIMPLE_RETURN_STATEMENT ::= return [EXPRESSION];
|
|
--
|
|
-- EXTENDED_RETURN_STATEMENT ::=
|
|
-- return DEFINING_IDENTIFIER : [aliased] RETURN_SUBTYPE_INDICATION
|
|
-- [:= EXPRESSION] [do
|
|
-- HANDLED_SEQUENCE_OF_STATEMENTS
|
|
-- end return];
|
|
--
|
|
-- RETURN_SUBTYPE_INDICATION ::= SUBTYPE_INDICATION | ACCESS_DEFINITION
|
|
|
|
-- RETURN_STATEMENT ::= return [EXPRESSION];
|
|
|
|
-- 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_Object_Declaration return Node_Id is
|
|
Return_Obj : Node_Id;
|
|
Decl_Node : Node_Id;
|
|
|
|
begin
|
|
Return_Obj := Token_Node;
|
|
Change_Identifier_To_Defining_Identifier (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);
|
|
|
|
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);
|
|
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
|
|
|
|
function Is_Simple return Boolean;
|
|
-- 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.
|
|
|
|
---------------
|
|
-- Is_Simple --
|
|
---------------
|
|
|
|
function Is_Simple return Boolean is
|
|
Scan_State : Saved_Scan_State;
|
|
Result : Boolean := True;
|
|
|
|
begin
|
|
if Token = Tok_Identifier then
|
|
Save_Scan_State (Scan_State); -- at identifier
|
|
Scan; -- past identifier
|
|
|
|
if Token = Tok_Colon then
|
|
Result := False; -- It's an extended_return_statement.
|
|
end if;
|
|
|
|
Restore_Scan_State (Scan_State); -- to identifier
|
|
end if;
|
|
|
|
return Result;
|
|
end Is_Simple;
|
|
|
|
Return_Sloc : constant Source_Ptr := Token_Ptr;
|
|
Return_Node : Node_Id;
|
|
|
|
-- Start of processing for P_Return_Statement
|
|
|
|
begin
|
|
Scan; -- past RETURN
|
|
|
|
-- 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 ;
|
|
Return_Node := New_Node (N_Simple_Return_Statement, Return_Sloc);
|
|
|
|
-- Non-trivial case
|
|
|
|
else
|
|
-- Simple_return_statement with expression
|
|
|
|
-- 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 Is_Simple then
|
|
Return_Node := New_Node (N_Simple_Return_Statement, Return_Sloc);
|
|
|
|
if Token not in Token_Class_Eterm then
|
|
Set_Expression (Return_Node, P_Expression_No_Right_Paren);
|
|
end if;
|
|
|
|
-- Extended_return_statement (Ada 2005 only -- AI-318):
|
|
|
|
else
|
|
if Ada_Version < Ada_05 then
|
|
Error_Msg_SP
|
|
(" extended_return_statement is an Ada 2005 extension");
|
|
Error_Msg_SP ("\unit must be compiled with -gnat05 switch");
|
|
end if;
|
|
|
|
Return_Node := New_Node (N_Extended_Return_Statement, Return_Sloc);
|
|
Set_Return_Object_Declarations
|
|
(Return_Node, New_List (P_Return_Object_Declaration));
|
|
|
|
if Token = Tok_Do then
|
|
Push_Scope_Stack;
|
|
Scope.Table (Scope.Last).Etyp := E_Return;
|
|
Scope.Table (Scope.Last).Ecol := Start_Column;
|
|
Scope.Table (Scope.Last).Sloc := Return_Sloc;
|
|
|
|
Scan; -- past DO
|
|
Set_Handled_Statement_Sequence
|
|
(Return_Node, P_Handled_Sequence_Of_Statements);
|
|
End_Statements;
|
|
|
|
-- Do we need to handle Error_Resync here???
|
|
end if;
|
|
end if;
|
|
|
|
TF_Semicolon;
|
|
end if;
|
|
|
|
return Return_Node;
|
|
end P_Return_Statement;
|
|
|
|
end Ch6;
|