(* M2Pass.mod provides setting and testing of the current pass.

Copyright (C) 2001-2023 Free Software Foundation, Inc.
Contributed by Gaius Mulley <gaius.mulley@southwales.ac.uk>.

This file is part of GNU Modula-2.

GNU Modula-2 is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3, or (at your option)
any later version.

GNU Modula-2 is distributed in the hope that it will be useful, but
WITHOUT 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
along with GNU Modula-2; see the file COPYING3.  If not see
<http://www.gnu.org/licenses/>.  *)

IMPLEMENTATION MODULE M2Pass ;

FROM M2Error IMPORT InternalError ;

TYPE
   Pass = (NoPass, Pass0, Pass1, Pass2, PassC, Pass3, CodeGeneration, ErrorPass, HiddenPass) ;

VAR
   CurrentPass: Pass ;


(*
   SetPassToNoPass - sets the pass state to no Pass.
*)

PROCEDURE SetPassToNoPass ;
BEGIN
   CurrentPass := NoPass
END SetPassToNoPass ;


(*
   SetPassToPass0 - sets the pass state to Pass 0.
*)

PROCEDURE SetPassToPass0 ;
BEGIN
   IF CurrentPass=NoPass
   THEN
      CurrentPass := Pass0
   ELSE
      InternalError ('attempting to set CurrentPass to Pass1')
   END
END SetPassToPass0 ;


(*
   SetPassToPass1 - sets the pass state to Pass 1.
*)

PROCEDURE SetPassToPass1 ;
BEGIN
   IF CurrentPass=NoPass
   THEN
      CurrentPass := Pass1
   ELSE
      InternalError ('attempting to set CurrentPass to Pass1')
   END
END SetPassToPass1 ;



(*
   SetPassToPass2 - sets the pass state to Pass 2.
*)

PROCEDURE SetPassToPass2 ;
BEGIN
   IF CurrentPass=NoPass
   THEN
      CurrentPass := Pass2
   ELSE
      InternalError ('attempting to set CurrentPass to Pass2')
   END
END SetPassToPass2 ;


(*
   SetPassToPassC - sets the pass state to Pass C.
*)

PROCEDURE SetPassToPassC ;
BEGIN
   IF CurrentPass=NoPass
   THEN
      CurrentPass := PassC
   ELSE
      InternalError ('attempting to set CurrentPass to PassC')
   END
END SetPassToPassC ;


(*
   SetPassToPass3 - sets the pass state to Pass 3.
*)

PROCEDURE SetPassToPass3 ;
BEGIN
   IF CurrentPass=NoPass
   THEN
      CurrentPass := Pass3
   ELSE
      InternalError ('attempting to set CurrentPass to Pass3')
   END
END SetPassToPass3 ;


(*
   SetPassToErrorPass - sets the pass state to no Error Pass.
*)

PROCEDURE SetPassToErrorPass ;
BEGIN
   CurrentPass := ErrorPass
END SetPassToErrorPass ;


(*
   SetPassToPassHidden - sets the pass state to the hidden type pass.
*)

PROCEDURE SetPassToPassHidden ;
BEGIN
   CurrentPass := HiddenPass
END SetPassToPassHidden ;


(*
   SetPassToCodeGeneration - sets the pass state to CodeGeneration.
*)

PROCEDURE SetPassToCodeGeneration ;
BEGIN
   IF CurrentPass=NoPass
   THEN
      CurrentPass := CodeGeneration
   ELSE
      InternalError ('attempting to set CurrentPass to CodeGeneration')
   END
END SetPassToCodeGeneration ;


(*
   IsNoPass - returns true if currently in no Pass.
*)

PROCEDURE IsNoPass () : BOOLEAN ;
BEGIN
   RETURN( CurrentPass=NoPass )
END IsNoPass ;


(*
   IsPass0 - returns true if currently in Pass 0.
*)

PROCEDURE IsPass0 () : BOOLEAN ;
BEGIN
   RETURN( CurrentPass=Pass0 )
END IsPass0 ;


(*
   IsPass1 - returns true if currently in Pass 1.
*)

PROCEDURE IsPass1 () : BOOLEAN ;
BEGIN
   RETURN( CurrentPass=Pass1 )
END IsPass1 ;


(*
   IsPass2 - returns true if currently in Pass 2.
*)

PROCEDURE IsPass2 () : BOOLEAN ;
BEGIN
   RETURN( CurrentPass=Pass2 )
END IsPass2 ;


(*
   IsPassC - returns true if currently in Pass C.
*)

PROCEDURE IsPassC () : BOOLEAN ;
BEGIN
   RETURN( CurrentPass=PassC )
END IsPassC ;


(*
   IsPass3 - returns true if currently in Pass 3.
*)

PROCEDURE IsPass3 () : BOOLEAN ;
BEGIN
   RETURN( CurrentPass=Pass3 )
END IsPass3 ;


(*
   IsPassCodeGeneration - returns true if currently in the CodeGeneration Pass.
*)

PROCEDURE IsPassCodeGeneration () : BOOLEAN ;
BEGIN
   RETURN( CurrentPass=CodeGeneration )
END IsPassCodeGeneration ;


(*
   IsPassHidden - returns TRUE if currently parsing for hidden types.
*)

PROCEDURE IsPassHidden () : BOOLEAN ;
BEGIN
   RETURN( CurrentPass=HiddenPass )
END IsPassHidden ;


(*
   IsErrorPass - returns true if currently in the Error Pass.
*)

PROCEDURE IsErrorPass () : BOOLEAN ;
BEGIN
   RETURN( CurrentPass=ErrorPass )
END IsErrorPass ;


BEGIN
   SetPassToNoPass
END M2Pass.