248 lines
9.2 KiB
Ada
248 lines
9.2 KiB
Ada
------------------------------------------------------------------------------
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-- --
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-- GNAT COMPILER COMPONENTS --
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-- --
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-- S C N --
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-- --
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-- B o d y --
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-- --
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-- Copyright (C) 1992-2020, 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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with Atree; use Atree;
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with Csets; use Csets;
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with Namet; use Namet;
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with Opt; use Opt;
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with Restrict; use Restrict;
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with Rident; use Rident;
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with Scans; use Scans;
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with Sinfo; use Sinfo;
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with Sinput; use Sinput;
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with Uintp; use Uintp;
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package body Scn is
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Used_As_Identifier : array (Token_Type) of Boolean;
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-- Flags set True if a given keyword is used as an identifier (used to
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-- make sure that we only post an error message for incorrect use of a
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-- keyword as an identifier once for a given keyword).
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----------------------------
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-- Determine_Token_Casing --
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----------------------------
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function Determine_Token_Casing return Casing_Type is
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begin
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return Scanner.Determine_Token_Casing;
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end Determine_Token_Casing;
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------------------------
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-- Initialize_Scanner --
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------------------------
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procedure Initialize_Scanner
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(Unit : Unit_Number_Type;
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Index : Source_File_Index) is
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begin
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Scanner.Initialize_Scanner (Index);
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Set_Unit (Index, Unit);
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Current_Source_Unit := Unit;
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-- Set default for Comes_From_Source. All nodes built now until we
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-- reenter the analyzer will have Comes_From_Source set to True
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Set_Comes_From_Source_Default (True);
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Check_For_BOM;
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-- Because of the License stuff above, Scng.Initialize_Scanner cannot
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-- call Scan. Scan initial token (note this initializes Prev_Token,
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-- Prev_Token_Ptr).
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Scan;
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-- Clear flags for reserved words used as identifiers
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Used_As_Identifier := (others => False);
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end Initialize_Scanner;
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---------------
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-- Post_Scan --
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---------------
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procedure Post_Scan is
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procedure Check_Obsolescent_Features_Restriction (S : Source_Ptr);
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-- This checks for Obsolescent_Features restriction being active, and
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-- if so, flags the restriction as occurring at the given scan location.
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procedure Check_Obsolete_Base_Char;
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-- Check for numeric literal using ':' instead of '#' for based case
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--------------------------------------------
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-- Check_Obsolescent_Features_Restriction --
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--------------------------------------------
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procedure Check_Obsolescent_Features_Restriction (S : Source_Ptr) is
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begin
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-- Normally we have a node handy for posting restrictions. We don't
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-- have such a node here, so construct a dummy one with the right
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-- scan pointer. This is only used to get the Sloc value anyway.
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Check_Restriction (No_Obsolescent_Features, New_Node (N_Empty, S));
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end Check_Obsolescent_Features_Restriction;
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------------------------------
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-- Check_Obsolete_Base_Char --
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------------------------------
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procedure Check_Obsolete_Base_Char is
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S : Source_Ptr;
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begin
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if Based_Literal_Uses_Colon then
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-- Find the : for the restriction or warning message
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S := Token_Ptr;
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while Source (S) /= ':' loop
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S := S + 1;
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end loop;
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Check_Obsolescent_Features_Restriction (S);
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if Warn_On_Obsolescent_Feature then
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Error_Msg
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("?j?use of "":"" is an obsolescent feature (RM J.2(3))", S);
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Error_Msg
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("\?j?use ""'#"" instead", S);
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end if;
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end if;
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end Check_Obsolete_Base_Char;
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-- Start of processing for Post_Scan
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begin
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case Token is
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when Tok_Char_Literal =>
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Token_Node := New_Node (N_Character_Literal, Token_Ptr);
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Set_Char_Literal_Value (Token_Node, UI_From_CC (Character_Code));
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Set_Chars (Token_Node, Token_Name);
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when Tok_Identifier =>
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Token_Node := New_Node (N_Identifier, Token_Ptr);
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Set_Chars (Token_Node, Token_Name);
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when Tok_Real_Literal =>
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Token_Node := New_Node (N_Real_Literal, Token_Ptr);
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Set_Realval (Token_Node, Real_Literal_Value);
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Check_Obsolete_Base_Char;
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when Tok_Integer_Literal =>
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Token_Node := New_Node (N_Integer_Literal, Token_Ptr);
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Set_Intval (Token_Node, Int_Literal_Value);
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Check_Obsolete_Base_Char;
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when Tok_String_Literal =>
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Token_Node := New_Node (N_String_Literal, Token_Ptr);
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Set_Has_Wide_Character
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(Token_Node, Wide_Character_Found);
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Set_Has_Wide_Wide_Character
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(Token_Node, Wide_Wide_Character_Found);
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Set_Strval (Token_Node, String_Literal_Id);
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if Source (Token_Ptr) = '%' then
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Check_Obsolescent_Features_Restriction (Token_Ptr);
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if Warn_On_Obsolescent_Feature then
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Error_Msg_SC
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("?j?use of ""'%"" is an obsolescent feature (RM J.2(4))");
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Error_Msg_SC ("\?j?use """""" instead");
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end if;
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end if;
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when Tok_Operator_Symbol =>
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Token_Node := New_Node (N_Operator_Symbol, Token_Ptr);
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Set_Chars (Token_Node, Token_Name);
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Set_Strval (Token_Node, String_Literal_Id);
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when Tok_Vertical_Bar =>
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if Source (Token_Ptr) = '!' then
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Check_Obsolescent_Features_Restriction (Token_Ptr);
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if Warn_On_Obsolescent_Feature then
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Error_Msg_SC
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("?j?use of ""'!"" is an obsolescent feature (RM J.2(2))");
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Error_Msg_SC ("\?j?use ""'|"" instead");
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end if;
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end if;
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when others =>
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null;
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end case;
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end Post_Scan;
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------------------------------
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-- Scan_Reserved_Identifier --
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------------------------------
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procedure Scan_Reserved_Identifier (Force_Msg : Boolean) is
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Token_Chars : String := Token_Type'Image (Token);
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Len : Natural := 0;
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begin
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-- AI12-0125 : '@' denotes the target_name, i.e. serves as an
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-- abbreviation for the LHS of an assignment.
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if Token = Tok_At_Sign then
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Token_Node := New_Node (N_Target_Name, Token_Ptr);
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return;
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end if;
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-- We have in Token_Chars the image of the Token name, i.e. Tok_xxx.
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-- This code extracts the xxx and makes an identifier out of it.
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for J in 5 .. Token_Chars'Length loop
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Len := Len + 1;
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Token_Chars (Len) := Fold_Lower (Token_Chars (J));
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end loop;
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Token_Name := Name_Find (Token_Chars (1 .. Len));
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-- If Inside_Pragma is True, we don't give an error. This is to allow
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-- things like "pragma Ignore_Pragma (Interface)", where "Interface" is
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-- a reserved word. There is no danger of missing errors, because any
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-- misuse must have been preceded by an illegal declaration. For
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-- example, in "pragma Pack (Begin);", either Begin is not declared,
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-- which is an error, or it is declared, which will be an error on that
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-- declaration.
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if (not Used_As_Identifier (Token) or else Force_Msg)
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and then not Inside_Pragma
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then
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Error_Msg_Name_1 := Token_Name;
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Error_Msg_SC ("reserved word* cannot be used as identifier!");
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Used_As_Identifier (Token) := True;
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end if;
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Token := Tok_Identifier;
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Token_Node := New_Node (N_Identifier, Token_Ptr);
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Set_Chars (Token_Node, Token_Name);
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end Scan_Reserved_Identifier;
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end Scn;
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