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|
------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- S C N --
-- --
-- B o d y --
-- --
-- Copyright (C) 1992-2023, 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 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 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. --
-- Extensive contributions were provided by Ada Core Technologies Inc. --
-- --
------------------------------------------------------------------------------
with Atree; use Atree;
with Csets; use Csets;
with Namet; use Namet;
with Restrict; use Restrict;
with Rident; use Rident;
with Scans; use Scans;
with Sinfo; use Sinfo;
with Sinfo.Nodes; use Sinfo.Nodes;
with Sinput; use Sinput;
with Uintp; use Uintp;
with Warnsw; use Warnsw;
package body Scn is
Used_As_Identifier : array (Token_Type) of Boolean;
-- Flags set True if a given keyword is used as an identifier (used to
-- make sure that we only post an error message for incorrect use of a
-- keyword as an identifier once for a given keyword).
----------------------------
-- Determine_Token_Casing --
----------------------------
function Determine_Token_Casing return Casing_Type is
begin
return Scanner.Determine_Token_Casing;
end Determine_Token_Casing;
------------------------
-- Initialize_Scanner --
------------------------
procedure Initialize_Scanner
(Unit : Unit_Number_Type;
Index : Source_File_Index) is
begin
Scanner.Initialize_Scanner (Index);
Set_Unit (Index, Unit);
Current_Source_Unit := Unit;
-- Set default for Comes_From_Source. All nodes built now until we
-- reenter the analyzer will have Comes_From_Source set to True
Set_Comes_From_Source_Default (True);
Check_For_BOM;
-- Because of the License stuff above, Scng.Initialize_Scanner cannot
-- call Scan. Scan initial token (note this initializes Prev_Token,
-- Prev_Token_Ptr).
Scan;
-- Clear flags for reserved words used as identifiers
Used_As_Identifier := (others => False);
end Initialize_Scanner;
---------------
-- Post_Scan --
---------------
procedure Post_Scan is
procedure Check_Obsolescent_Features_Restriction (S : Source_Ptr);
-- This checks for Obsolescent_Features restriction being active, and
-- if so, flags the restriction as occurring at the given scan location.
procedure Check_Obsolete_Base_Char;
-- Check for numeric literal using ':' instead of '#' for based case
--------------------------------------------
-- Check_Obsolescent_Features_Restriction --
--------------------------------------------
procedure Check_Obsolescent_Features_Restriction (S : Source_Ptr) is
begin
-- Normally we have a node handy for posting restrictions. We don't
-- have such a node here, so construct a dummy one with the right
-- scan pointer. This is only used to get the Sloc value anyway.
Check_Restriction (No_Obsolescent_Features, New_Node (N_Empty, S));
end Check_Obsolescent_Features_Restriction;
------------------------------
-- Check_Obsolete_Base_Char --
------------------------------
procedure Check_Obsolete_Base_Char is
S : Source_Ptr;
begin
if Based_Literal_Uses_Colon then
-- Find the : for the restriction or warning message
S := Token_Ptr;
while Source (S) /= ':' loop
S := S + 1;
end loop;
Check_Obsolescent_Features_Restriction (S);
if Warn_On_Obsolescent_Feature then
Error_Msg
("?j?use of "":"" is an obsolescent feature (RM J.2(3))", S);
Error_Msg
("\?j?use ""'#"" instead", S);
end if;
end if;
end Check_Obsolete_Base_Char;
-- Start of processing for Post_Scan
begin
case Token is
when Tok_Char_Literal =>
Token_Node := New_Node (N_Character_Literal, Token_Ptr);
Set_Char_Literal_Value (Token_Node, UI_From_CC (Character_Code));
Set_Chars (Token_Node, Token_Name);
when Tok_Identifier =>
Token_Node := New_Node (N_Identifier, Token_Ptr);
Set_Chars (Token_Node, Token_Name);
when Tok_Real_Literal =>
Token_Node := New_Node (N_Real_Literal, Token_Ptr);
Set_Realval (Token_Node, Real_Literal_Value);
Check_Obsolete_Base_Char;
when Tok_Integer_Literal =>
Token_Node := New_Node (N_Integer_Literal, Token_Ptr);
-- Int_Literal_Value can be No_Uint in some cases in syntax-only
-- mode (see Scng.Scan.Nlit).
if Present (Int_Literal_Value) then
Set_Intval (Token_Node, Int_Literal_Value);
end if;
Check_Obsolete_Base_Char;
when Tok_String_Literal =>
Token_Node := New_Node (N_String_Literal, Token_Ptr);
Set_Has_Wide_Character
(Token_Node, Wide_Character_Found);
Set_Has_Wide_Wide_Character
(Token_Node, Wide_Wide_Character_Found);
Set_Strval (Token_Node, String_Literal_Id);
if Source (Token_Ptr) = '%' then
Check_Obsolescent_Features_Restriction (Token_Ptr);
if Warn_On_Obsolescent_Feature then
Error_Msg_SC
("?j?use of ""'%"" is an obsolescent feature (RM J.2(4))");
Error_Msg_SC ("\?j?use """""" instead");
end if;
end if;
when Tok_Operator_Symbol =>
Token_Node := New_Node (N_Operator_Symbol, Token_Ptr);
Set_Chars (Token_Node, Token_Name);
Set_Strval (Token_Node, String_Literal_Id);
when Tok_Vertical_Bar =>
if Source (Token_Ptr) = '!' then
Check_Obsolescent_Features_Restriction (Token_Ptr);
if Warn_On_Obsolescent_Feature then
Error_Msg_SC
("?j?use of ""'!"" is an obsolescent feature (RM J.2(2))");
Error_Msg_SC ("\?j?use ""'|"" instead");
end if;
end if;
when others =>
null;
end case;
end Post_Scan;
------------------------------
-- Scan_Reserved_Identifier --
------------------------------
procedure Scan_Reserved_Identifier (Force_Msg : Boolean) is
Token_Chars : String := Token_Type'Image (Token);
Len : Natural := 0;
begin
-- AI12-0125 : '@' denotes the target_name, i.e. serves as an
-- abbreviation for the LHS of an assignment.
if Token = Tok_At_Sign then
Token_Node := New_Node (N_Target_Name, Token_Ptr);
return;
end if;
-- We have in Token_Chars the image of the Token name, i.e. Tok_xxx.
-- This code extracts the xxx and makes an identifier out of it.
for J in 5 .. Token_Chars'Length loop
Len := Len + 1;
Token_Chars (Len) := Fold_Lower (Token_Chars (J));
end loop;
Token_Name := Name_Find (Token_Chars (1 .. Len));
-- If Inside_Pragma is True, we don't give an error. This is to allow
-- things like "pragma Ignore_Pragma (Interface)", where "Interface" is
-- a reserved word. There is no danger of missing errors, because any
-- misuse must have been preceded by an illegal declaration. For
-- example, in "pragma Pack (Begin);", either Begin is not declared,
-- which is an error, or it is declared, which will be an error on that
-- declaration.
if (not Used_As_Identifier (Token) or else Force_Msg)
and then not Inside_Pragma
then
Error_Msg_Name_1 := Token_Name;
Error_Msg_SC ("reserved word* cannot be used as identifier!");
Used_As_Identifier (Token) := True;
end if;
Token := Tok_Identifier;
Token_Node := New_Node (N_Identifier, Token_Ptr);
Set_Chars (Token_Node, Token_Name);
end Scan_Reserved_Identifier;
end Scn;
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