PR modula2/115328: use enable forward bool and set default true

This patch introduces GetEnableForward and SetEnableForward
against which the forward procedure declaration feature is checked.
Currently this is set as default true.

gcc/m2/ChangeLog:

	PR modula2/115328
	* gm2-compiler/M2Options.def (GetEnableForward): New procedure
	function.
	(SetEnableForward): New procedure.
	* gm2-compiler/M2Options.mod (GetEnableForward): New procedure
	function.
	(SetEnableForward): New procedure.
	(EnableForward): New boolean.
	* gm2-compiler/P1SymBuild.mod (EndBuildForward): Check
	GetEnableForward and generate an error message if false.

gcc/testsuite/ChangeLog:

	PR modula2/115328
	* gm2/pim/fail/forward.mod: Move to...
	* gm2/pim/pass/forward.mod: ...here.

Signed-off-by: Gaius Mulley <gaiusmod2@gmail.com>

4 files changed, 40 insertions, 4 deletions

diff --git a/gcc/m2/gm2-compiler/M2Options.def b/gcc/m2/gm2-compiler/M2Options.def
index baa5d7e..1f483e6 100644
--- a/gcc/m2/gm2-compiler/M2Options.def
+++ b/gcc/m2/gm2-compiler/M2Options.def
@@ -1122,6 +1122,20 @@ PROCEDURE GetDebugFunctionLineNumbers () : BOOLEAN ;
 
 
 (*
+   GetEnableForward - return EnableForward.
+*)
+
+PROCEDURE GetEnableForward () : BOOLEAN ;
+
+
+(*
+   SetEnableForward - set EnableForward to value.
+*)
+
+PROCEDURE SetEnableForward (value: BOOLEAN) ;
+
+
+(*
    FinaliseOptions - once all options have been parsed we set any inferred
                      values.
 *)
diff --git a/gcc/m2/gm2-compiler/M2Options.mod b/gcc/m2/gm2-compiler/M2Options.mod
index 4048144..8f4e326 100644
--- a/gcc/m2/gm2-compiler/M2Options.mod
+++ b/gcc/m2/gm2-compiler/M2Options.mod
@@ -76,6 +76,7 @@ VAR
    UselistFilename,
    RuntimeModuleOverride,
    CppArgs              : String ;
+   EnableForward,
    DebugFunctionLineNumbers,
    DebugTraceQuad,   (* -fm2-debug-trace=quad.  *)
    DebugTraceLine,   (* -fm2-debug-trace=line.  *)
@@ -2008,6 +2009,26 @@ BEGIN
 END GetDumpDecl ;
 
 
+(*
+   GetEnableForward - return EnableForward.
+*)
+
+PROCEDURE GetEnableForward () : BOOLEAN ;
+BEGIN
+   RETURN EnableForward
+END GetEnableForward ;
+
+
+(*
+   SetEnableForward - set EnableForward to value.
+*)
+
+PROCEDURE SetEnableForward (value: BOOLEAN) ;
+BEGIN
+   EnableForward := value
+END SetEnableForward ;
+
+
 BEGIN
    cflag                             := FALSE ;  (* -c.  *)
    RuntimeModuleOverride             := InitString (DefaultRuntimeModuleOverride) ;
@@ -2099,5 +2120,6 @@ BEGIN
    DumpQuad                          := FALSE ;
    DumpGimple                        := FALSE ;
    M2Dump                            := NIL ;
-   M2DumpFilter                      := NIL
+   M2DumpFilter                      := NIL ;
+   EnableForward                     := TRUE
 END M2Options.
diff --git a/gcc/m2/gm2-compiler/P1SymBuild.mod b/gcc/m2/gm2-compiler/P1SymBuild.mod
index cd42417..e916fb6 100644
--- a/gcc/m2/gm2-compiler/P1SymBuild.mod
+++ b/gcc/m2/gm2-compiler/P1SymBuild.mod
@@ -32,7 +32,7 @@ FROM M2MetaError IMPORT MetaErrorString2, MetaError0, MetaError1,
 
 FROM DynamicStrings IMPORT String, Slice, InitString, KillString, EqualCharStar, RIndex, Mark, ConCat ;
 FROM M2Printf IMPORT printf0, printf1, printf2 ;
-FROM M2Options IMPORT Iso ;
+FROM M2Options IMPORT Iso, GetEnableForward ;
 
 FROM M2Reserved IMPORT ImportTok, ExportTok, QualifiedTok, UnQualifiedTok,
                        NulTok, VarTok, ArrayTok, BuiltinTok, InlineTok ;
@@ -1074,10 +1074,10 @@ VAR
 BEGIN
    ProcSym := OperandT (1) ;
    tok := OperandTok (1) ;
-   IF NOT Iso
+   IF NOT GetEnableForward ()
    THEN
       MetaErrorT0 (forwardPos,
-                   'forward declaration is only allowed in the ISO dialect of Modula-2')
+                   'forward declaration has not been enabled, use -fiso or -fenable-forward to enable forward procedure declarations')
    END ;
    IF GetProcedureDefined (ProcSym, ForwardProcedure)
    THEN
diff --git a/gcc/testsuite/gm2/pim/fail/forward.mod b/gcc/testsuite/gm2/pim/pass/forward.mod
index 123e006..123e006 100644
--- a/gcc/testsuite/gm2/pim/fail/forward.mod
+++ b/gcc/testsuite/gm2/pim/pass/forward.mod