PR modula2/109264 Bugfix resolve opaque types containing sets

Resolve opaque type handling.  The bug is caused by the compiler
attempting to resolve the meta types of a constant constructor.
It incorrectly attempts to get the type on an enumeration type
(resulting in NulSym) which causes the meta resolver to spin.
Some PHBuild rules (building records need to be copied from P3Build
so that hidden types are resolved in order across the compile.

gcc/m2/ChangeLog:

	PR modula2/109264
	* gm2-compiler/M2Quads.mod (BuildConstFunctionCall): Comment
	out ErrorString in debugging block.
	(BuildConstructorStart): Replace Assert with a call to
	MetaErrorT3.  Import MetaErrorT3.
	* gm2-compiler/PCSymBuild.mod (buildConstFunction): Rename
	local variables.
	(WalkFunctionParam): Remove test for IsEnumeration when
	resolving MIN or MAX parameters.
	* gm2-compiler/PHBuild.bnf (BlockAssert): New procedure.
	(ErrorArrayat): New procedure.
	(Expect): Renamed parameter t to tok.
	(PushQualident): New rule.
	(ConstSetOrQualidentOrFunction): Force AutoOn.
	(TypeDeclaration): Add debugging assert.
	(SimpleType): Add debugging assert.
	(DefaultRecordAttributes): New rule (and bugfix).
	(FieldPragmaExpression): New rule (and bugfix).
	(PragmaConstExpression): New rule (and bugfix).
	(SetOrDesignatorOrFunction): Add debugging assert.
	(Block): Add debugging assert.
	* gm2-gcc/m2expr.cc (m2expr_ConstantExpressionWarning): int
	to bool.
	* gm2-gcc/m2expr.h (m2expr_TreeOverflow): int to bool.
	(m2expr_GetBooleanTrue): Remove.
	(m2expr_GetBooleanFalse): Remove.
	* gm2-gcc/m2options.h (M2Options_SetStatistics): Replace
	int with bool.

gcc/testsuite/ChangeLog:

	PR modula2/109264
	* gm2/iso/extended-opaque/pass/iso-extended-opaque-pass.exp:
	New test.
	* gm2/iso/extended-opaque/pass/stressset.def: New test.
	* gm2/iso/extended-opaque/pass/stressset.mod: New test.
	* gm2/iso/extended-opaque/pass/testset.mod: New test.
	* gm2/projects/iso/small/run/pass/iso-extended-opaque-run-pass.exp:
	New test.
	* gm2/projects/iso/small/run/pass/stressset.def: New test.
	* gm2/projects/iso/small/run/pass/stressset.mod: New test.
	* gm2/projects/iso/small/run/pass/test1.mod: New test.
	* gm2/projects/iso/small/run/pass/testlib.def: New test.
	* gm2/projects/iso/small/run/pass/testlib.mod: New test.
	* gm2/projects/iso/small/run/pass/testset.mod: New test.

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

6 files changed, 206 insertions, 80 deletions

diff --git a/gcc/m2/gm2-compiler/M2Quads.mod b/gcc/m2/gm2-compiler/M2Quads.mod
index 4dffb63..a44c5c7 100644
--- a/gcc/m2/gm2-compiler/M2Quads.mod
+++ b/gcc/m2/gm2-compiler/M2Quads.mod
@@ -34,7 +34,7 @@ FROM M2Scaffold IMPORT DeclareScaffold, mainFunction, initFunction,
 FROM M2MetaError IMPORT MetaError0, MetaError1, MetaError2, MetaError3,
                         MetaErrors1, MetaErrors2, MetaErrors3,
                         MetaErrorT0, MetaErrorT1, MetaErrorT2,
-                        MetaErrorsT1, MetaErrorsT2,
+                        MetaErrorsT1, MetaErrorsT2, MetaErrorT3,
                         MetaErrorStringT0, MetaErrorStringT1,
                         MetaErrorString1, MetaErrorString2,
                         MetaErrorN1, MetaErrorN2,
@@ -7492,7 +7492,7 @@ BEGIN
    IF CompilerDebugging
    THEN
       printf2 ('procsym = %d  token = %d\n', ProcSym, functok) ;
-      ErrorStringAt (InitString ('constant function'), functok)
+      (* ErrorStringAt (InitString ('constant function'), functok) *)
    END ;
    PushT (NoOfParam) ;
    IF (ProcSym # Convert) AND
@@ -12064,7 +12064,12 @@ VAR
 BEGIN
    PopT (type) ;   (* we ignore the type as we already have the constructor symbol from pass C *)
    GetConstructorFromFifoQueue (constValue) ;
-   Assert (type = GetSType (constValue)) ;
+   IF type # GetSType (constValue)
+   THEN
+      MetaErrorT3 (cbratokpos,
+                   '{%E}the constructor type is {%1ad} and this is different from the constant {%2ad} which has a type {%2tad}',
+                   type, constValue, constValue)
+   END ;
    PushTtok (constValue, cbratokpos) ;
    PushConstructor (type)
 END BuildConstructorStart ;
diff --git a/gcc/m2/gm2-compiler/PCSymBuild.mod b/gcc/m2/gm2-compiler/PCSymBuild.mod
index 887dd02..59b1652 100644
--- a/gcc/m2/gm2-compiler/PCSymBuild.mod
+++ b/gcc/m2/gm2-compiler/PCSymBuild.mod
@@ -1154,7 +1154,7 @@ PROCEDURE InitFunction (m: constType; p, t: CARDINAL; f, s: exprNode; more: BOOL
 VAR
    n: exprNode ;
 BEGIN
-   NEW(n) ;
+   NEW (n) ;
    WITH n^ DO
       tag := function ;
       CASE tag OF
@@ -1170,7 +1170,7 @@ BEGIN
 
       END
    END ;
-   PushAddress(exprStack, n)
+   PushAddress (exprStack, n)
 END InitFunction ;
 
 
@@ -1342,21 +1342,21 @@ PROCEDURE TypeToMeta (type: CARDINAL) : constType ;
 BEGIN
    IF type=Char
    THEN
-      RETURN( char )
+      RETURN char
    ELSIF type=Boolean
    THEN
-      RETURN( boolean )
-   ELSIF IsRealType(type)
+      RETURN boolean
+   ELSIF IsRealType (type)
    THEN
-      RETURN( rtype )
-   ELSIF IsComplexType(type)
+      RETURN rtype
+   ELSIF IsComplexType (type)
    THEN
-      RETURN( ctype )
-   ELSIF IsOrdinalType(type)
+      RETURN ctype
+   ELSIF IsOrdinalType (type)
    THEN
-      RETURN( ztype )
+      RETURN ztype
    ELSE
-      RETURN( unknown )
+      RETURN unknown
    END
 END TypeToMeta ;
 
@@ -1371,33 +1371,35 @@ END TypeToMeta ;
 
 PROCEDURE buildConstFunction (func: CARDINAL; n: CARDINAL) ;
 VAR
-   i   : CARDINAL ;
-   f, s: exprNode ;
+   i     : CARDINAL ;
+   first,
+   second: exprNode ;
 BEGIN
-   f := NIL ;
-   s := NIL ;
+   first := NIL ;
+   second := NIL ;
    IF n=1
    THEN
-      f := PopAddress(exprStack)
+      first := PopAddress (exprStack)
    ELSIF n>=2
    THEN
       i := n ;
       WHILE i>2 DO
-         s := PopAddress(exprStack) ;
-         DISPOSE(s) ;
-         DEC(i)
+         second := PopAddress (exprStack) ;
+         DISPOSE (second) ;
+         DEC (i)
       END ;
-      s := PopAddress(exprStack) ;
-      f := PopAddress(exprStack)
+      second := PopAddress (exprStack) ;
+      first := PopAddress (exprStack)
    END ;
    IF func=Val
    THEN
-      InitConvert(cast, NulSym, f, s)
+      InitConvert (cast, NulSym, first, second)
    ELSIF (func=Max) OR (func=Min)
    THEN
-      InitFunction(unknown, func, NulSym, f, s, FALSE)
+      InitFunction (unknown, func, NulSym, first, second, FALSE)
    ELSE
-      InitFunction(TypeToMeta(GetSkippedType(func)), func, GetSkippedType(func), f, s, n>2)
+      InitFunction (TypeToMeta(GetSkippedType(func)), func, GetSkippedType(func),
+                    first, second, n>2)
    END
 END buildConstFunction ;
 
@@ -1788,7 +1790,7 @@ BEGIN
             THEN
                IF (func=Min) OR (func=Max)
                THEN
-                  IF IsEnumeration(sym) OR IsSet(sym)
+                  IF IsSet (sym)
                   THEN
                      type := SkipType(GetType(sym))
                   ELSE
@@ -1832,7 +1834,7 @@ BEGIN
                type := getEtype(first) ;
                RETURN( TRUE )
             END ;
-            RETURN( WalkFunctionParam(func, first) )
+            RETURN WalkFunctionParam (func, first)
          ELSE
             MetaError1('not expecting this function inside a constant expression {%1Dad}', func)
          END
@@ -2059,9 +2061,13 @@ PROCEDURE WalkDes (d: exprNode) : BOOLEAN ;
 BEGIN
    IF d=NIL
    THEN
-      RETURN( FALSE )
+      RETURN FALSE
    ELSE
-      RETURN( doWalkDes(d) )
+      IF Debugging
+      THEN
+         DebugDes (d)
+      END ;
+      RETURN doWalkDes (d)
    END
 END WalkDes ;
 
diff --git a/gcc/m2/gm2-compiler/PHBuild.bnf b/gcc/m2/gm2-compiler/PHBuild.bnf
index a9ec1e6..a13da82 100644
--- a/gcc/m2/gm2-compiler/PHBuild.bnf
+++ b/gcc/m2/gm2-compiler/PHBuild.bnf
@@ -44,7 +44,9 @@ see <https://www.gnu.org/licenses/>.  *)
 
 IMPLEMENTATION MODULE PHBuild ;
 
-FROM M2LexBuf IMPORT currentstring, currenttoken, GetToken, InsertToken, InsertTokenAndRewind, GetTokenNo ;
+FROM M2LexBuf IMPORT currentstring, currenttoken, GetToken, InsertToken,
+                     InsertTokenAndRewind, GetTokenNo, MakeVirtualTok ;
+
 FROM M2Error IMPORT ErrorStringAt ;
 FROM NameKey IMPORT NulName, Name, makekey ;
 FROM M2Reserved IMPORT NulTok, ByTok, PeriodPeriodTok, tokToTok, toktype ;
@@ -55,6 +57,7 @@ FROM P2SymBuild IMPORT BuildString, BuildNumber ;
 
 FROM M2Quads IMPORT PushT, PopT, PushTF, PopTF, PopNothing, Annotate,
                     PushTtok, PushTFtok, PopTtok, PopTFtok, OperandTok,
+                    PushTFntok, Top,
                     StartBuildDefFile, StartBuildModFile,
                     BuildModuleStart,
                     EndBuildFile,
@@ -98,7 +101,8 @@ FROM M2Quads IMPORT PushT, PopT, PushTF, PopTF, PopNothing, Annotate,
                     BeginVarient, EndVarient, ElseVarient,
                     BeginVarientList, EndVarientList,
                     AddVarientRange, AddVarientEquality,
-                    CheckWithReference,
+                    BuildDefaultFieldAlignment, BuildPragmaField,
+                    CheckWithReference, DisplayStack, Annotate,
                     IsAutoPushOn, PushAutoOff, PushAutoOn, PopAuto ;
 
 FROM P3SymBuild IMPORT P3StartBuildProgModule,
@@ -120,6 +124,8 @@ FROM P3SymBuild IMPORT P3StartBuildProgModule,
                        BuildSubrange,
                        BuildNulName ;
 
+FROM P3SymBuild IMPORT CheckCanBeImported ;
+
 FROM SymbolTable IMPORT MakeGnuAsm, PutGnuAsmVolatile, PutGnuAsm, PutGnuAsmInput,
                         PutGnuAsmOutput, PutGnuAsmTrash, PutGnuAsmVolatile,
                         MakeRegInterface,
@@ -129,7 +135,7 @@ FROM SymbolTable IMPORT MakeGnuAsm, PutGnuAsmVolatile, PutGnuAsm, PutGnuAsmInput
                         StartScope, EndScope,
                         PutIncluded,
                         IsVarParam, IsProcedure, IsDefImp, IsModule,
-                        IsRecord,
+                        IsRecord, IsProcType,
                         RequestSym,
                         GetSym, GetLocalSym ;
 
@@ -140,21 +146,34 @@ FROM M2CaseList IMPORT BeginCaseList, EndCaseList, ElseCase ;
 FROM M2Reserved IMPORT NulTok, ImportTok, ExportTok, QualifiedTok, UnQualifiedTok,
                        EqualTok, HashTok, LessGreaterTok, LessTok, LessEqualTok,
                        GreaterTok, GreaterEqualTok, InTok, PlusTok, MinusTok,
-                       OrTok, TimesTok, DivTok, DivideTok, ModTok, RemTok, AndTok, AmbersandTok ;
+                       OrTok, TimesTok, DivTok, DivideTok, ModTok, RemTok, AndTok,
+                       AmbersandTok ;
 
 IMPORT M2Error ;
 
 
 CONST
    Debugging = FALSE ;
-   Pass1     = FALSE ;          (* permanently disabled for the time being *)
-   Pass2     = FALSE ;          (* permanently disabled for the time being *)
-   Pass3     = FALSE ;
 
 VAR
    WasNoError: BOOLEAN ;
 
 
+(*
+   BlockAssert - used when developing, if disabled the bug (incorrect stack level)
+                 will be caught by the block and a user error issued.
+                 This procedure useful to detect the failure earlier.
+*)
+
+PROCEDURE BlockAssert (value: BOOLEAN) ;
+BEGIN
+   IF Debugging
+   THEN
+      Assert (value)
+   END
+END BlockAssert ;
+
+
 PROCEDURE ErrorString (s: String) ;
 BEGIN
    ErrorStringAt(s, GetTokenNo()) ;
@@ -168,6 +187,11 @@ BEGIN
 END ErrorArray ;
 
 
+PROCEDURE ErrorArrayAt (a: ARRAY OF CHAR; tok: CARDINAL) ;
+BEGIN
+   ErrorStringAt (InitString(a), tok)
+END ErrorArrayAt ;
+
 % declaration PHBuild begin
 
 
@@ -315,7 +339,8 @@ BEGIN
       (NOT InStopSet(identtok, stopset0, stopset1, stopset2))
    THEN
       (* SyntaxCheck would fail since currentoken is not part of the stopset
-         we check to see whether any of currenttoken might be a commonly omitted token *)
+         we check to see whether any of currenttoken might be a commonly
+         omitted token.  *)
       IF CheckAndInsert(semicolontok, stopset0, stopset1, stopset2) OR
          CheckAndInsert(rsbratok, stopset0, stopset1, stopset2) OR
          CheckAndInsert(rparatok, stopset0, stopset1, stopset2) OR
@@ -334,19 +359,16 @@ END PeepToken ;
    Expect -
 *)
 
-PROCEDURE Expect (t: toktype; stopset0: SetOfStop0; stopset1: SetOfStop1; stopset2: SetOfStop2) ;
+PROCEDURE Expect (tok: toktype; stopset0: SetOfStop0; stopset1: SetOfStop1;
+                  stopset2: SetOfStop2) ;
 BEGIN
-   IF currenttoken=t
+   IF currenttoken=tok
    THEN
-      GetToken ;
-      IF Pass1
-      THEN
-         PeepToken(stopset0, stopset1, stopset2)
-      END
+      GetToken
    ELSE
-      MissingToken(t)
+      MissingToken (tok)
    END ;
-   SyntaxCheck(stopset0, stopset1, stopset2)
+   SyntaxCheck (stopset0, stopset1, stopset2)
 END Expect ;
 
 
@@ -358,8 +380,8 @@ END Expect ;
 PROCEDURE CompilationUnit () : BOOLEAN ;
 BEGIN
    WasNoError := TRUE ;
-   FileUnit(SetOfStop0{eoftok}, SetOfStop1{}, SetOfStop2{}) ;
-   RETURN( WasNoError )
+   FileUnit (SetOfStop0{eoftok}, SetOfStop1{}, SetOfStop2{}) ;
+   RETURN WasNoError
 END CompilationUnit ;
 
 
@@ -369,11 +391,11 @@ END CompilationUnit ;
 
 PROCEDURE Ident (stopset0: SetOfStop0; stopset1: SetOfStop1; stopset2: SetOfStop2) ;
 BEGIN
-   IF IsAutoPushOn()
+   IF IsAutoPushOn ()
    THEN
-      PushTF(makekey(currentstring), identtok)
+      PushTF (makekey (currentstring), identtok)
    END ;
-   Expect(identtok, stopset0, stopset1, stopset2)
+   Expect (identtok, stopset0, stopset1, stopset2)
 END Ident ;
 
 
@@ -592,6 +614,7 @@ ImplementationOrProgramModule :=                                           % Pus
 
 Number := Integer | Real =:
 
+
 Qualident :=                                                               % VAR name: Name ;
                                                                                  Type, Sym, tok: CARDINAL ; %
              Ident
@@ -616,6 +639,71 @@ Qualident :=                                                               % VAR
              { "." Ident }                                                 % END %
            =:
 
+PushQualident :=                                                           % VAR name         : Name ;
+                                                                                 init, ip1    : CARDINAL ;
+                                                                                 tok, tokstart: CARDINAL ; %
+                                                                           % PushAutoOn %
+             Ident                                                         % IF IsAutoPushOn()
+                                                                             THEN
+                                                                                PopTtok (name, tokstart) ;
+                                                                                tok := tokstart ;
+                                                                                init := GetSym (name) ;
+                                                                                IF init=NulSym
+                                                                                THEN
+                                                                                   PushTFntok (NulSym, NulSym, name, tok)
+                                                                                ELSE
+                                                                                   WHILE IsDefImp (init) OR IsModule (init) DO
+                                                                                      IF currenttoken # periodtok
+                                                                                      THEN
+                                                                                         ErrorArrayAt ("expecting '.' after module in the construction of a qualident", tok) ;
+                                                                                         IF tok#tokstart
+                                                                                         THEN
+                                                                                            tok := MakeVirtualTok (tokstart, tokstart, tok)
+                                                                                         END ;
+                                                                                         PushTtok (init, tok) ;
+                                                                                         PopAuto ;
+                                                                                         RETURN
+                                                                                      ELSE
+                                                                                         Expect (periodtok, stopset0, stopset1, stopset2 + SetOfStop2{identtok}) ;
+                                                                                         StartScope (init) ;
+                                                                                         Ident (stopset0, stopset1, stopset2) ;
+                                                                                         PopTtok (name, tok) ;
+                                                                                         ip1 := GetSym (name) ;
+                                                                                         IF ip1 = NulSym
+                                                                                         THEN
+                                                                                            ErrorArrayAt ("unknown ident in the construction of a qualident", tok) ;
+                                                                                            EndScope ;
+                                                                                            IF tok#tokstart
+                                                                                            THEN
+                                                                                               tok := MakeVirtualTok (tokstart, tokstart, tok)
+                                                                                            END ;
+                                                                                            PushTFntok (NulSym, NulSym, name, tok) ;
+                                                                                            PopAuto ;
+                                                                                            RETURN
+                                                                                         ELSE
+                                                                                            PutIncluded (ip1)
+                                                                                         END ;
+                                                                                         EndScope ;
+                                                                                         CheckCanBeImported (init, ip1) ;
+                                                                                         init := ip1
+                                                                                      END
+                                                                                   END ;
+                                                                                   IF tok#tokstart
+                                                                                   THEN
+                                                                                      tok := MakeVirtualTok (tokstart, tokstart, tok)
+                                                                                   END ;
+                                                                                   IF IsProcedure (init) OR IsProcType (init)
+                                                                                   THEN
+                                                                                      PushTtok (init, tok)
+                                                                                   ELSE
+                                                                                      PushTFtok (init, GetType(init), tok)
+                                                                                   END
+                                                                                END
+                                                                             ELSE %
+             { "." Ident }                                                 % END %
+                                                                           % PopAuto %
+           =:
+
 ConstantDeclaration :=                                                     % PushAutoOn %
                                                                            % VAR tokno: CARDINAL ; %
                        ( Ident "="                                         % tokno := GetTokenNo () %
@@ -709,11 +797,16 @@ Constructor := '{'                                                         % Bui
                   [ ArraySetRecordValue ]                                  % BuildConstructorEnd (GetTokenNo())  %
                '}' =:
 
-ConstSetOrQualidentOrFunction := Qualident
-                                 [ Constructor | ConstActualParameters     % BuildConstFunctionCall %
-                                                                       ]
-                                   |                                       % BuildTypeForConstructor %
-                                     Constructor =:
+ConstSetOrQualidentOrFunction :=                                            % PushAutoOn %
+                                 (
+                                    Qualident
+                                    [ Constructor |
+                                       ConstActualParameters               % BuildConstFunctionCall %
+                                                                          ]
+                                      |                                    % BuildTypeForConstructor %
+                                        Constructor
+                                 )                                          % PopAuto %
+                                =:
 
 ConstAttribute := "__ATTRIBUTE__" "__BUILTIN__" "(" "(" ConstAttributeExpression ")" ")" =:
 
@@ -730,7 +823,10 @@ ByteAlignment := '<*'                                                      % Pus
 
 Alignment := [ ByteAlignment ] =:
 
-TypeDeclaration := Ident "=" Type Alignment
+TypeDeclaration :=                                                         % VAR top: CARDINAL ; %
+                                                                           % top := Top () %
+                   Ident "=" Type Alignment
+                                                                           % BlockAssert (top = Top ()) %
                 =:
 
 Type :=
@@ -742,7 +838,11 @@ Type :=
           | ProcedureType )                                                % PopAuto %
       =:
 
-SimpleType := Qualident [ SubrangeType ] | Enumeration | SubrangeType =:
+SimpleType :=                                                              % VAR top: CARDINAL ; %
+                                                                           % top := Top () %
+              ( Qualident [ SubrangeType ] | Enumeration | SubrangeType )
+                                                                           % BlockAssert (top = Top ()) %
+            =:
 
 Enumeration := "("
                    ( IdentList
@@ -782,18 +882,24 @@ ArrayType := "ARRAY"
 
 RecordType := "RECORD" [ DefaultRecordAttributes ] FieldListSequence "END" =:
 
-DefaultRecordAttributes := '<*' AttributeExpression '*>' =:
+DefaultRecordAttributes := '<*'                                           % PushAutoOn %
+                                AttributeExpression                       % BuildDefaultFieldAlignment %
+                                                                          % PopAuto %
+                                                    '*>' =:
 
 RecordFieldPragma := [ '<*' FieldPragmaExpression
-                        { ',' FieldPragmaExpression } '*>' ] =:
+                            { ',' FieldPragmaExpression } '*>' ] =:
 
-FieldPragmaExpression :=                                                    % PushAutoOff %
-                         Ident [ '(' ConstExpression ')' ]                  % PopAuto %
+FieldPragmaExpression :=                                                   % PushAutoOn %
+                         Ident PragmaConstExpression                       % BuildPragmaField %
+                                                                           % PopAuto %
                                                            =:
 
-AttributeExpression :=                                                      % PushAutoOff %
-                       Ident '(' ConstExpression ')'                        % PopAuto %
-                                                      =:
+PragmaConstExpression := ( '(' ConstExpression ')' |                       % PushT(NulSym) %
+                                                                           % Annotate('NulSym||no pragma const') %
+                                                     )     =:
+
+AttributeExpression := Ident '(' ConstExpression ')' =:
 
 FieldListSequence := FieldListStatement { ";" FieldListStatement } =:
 
@@ -1002,12 +1108,21 @@ Term := Factor { SilentMulOperator Factor
 Factor := Number | string | SetOrDesignatorOrFunction |
           "(" Expression ")" | "NOT" Factor | ConstAttribute =:
 
--- again Set | Designator causes problems as both has a first symbol, ident or Qualident
+-- again Set | Designator causes problems as both have a first symbol, ident or Qualident
+
+ParseConstructor := "{" [ SilentElement { "," SilentElement } ] "}" =:
+
 
-SetOrDesignatorOrFunction := ( Qualident [ Constructor |
-                                           SimpleDes [ ActualParameters ]
-                                         ] | Constructor
+SetOrDesignatorOrFunction :=                                               % VAR n: CARDINAL ; %
+                                                                           % n := Top () %
+                                                                           % Assert (NOT IsAutoPushOn ()) %
+                             ( Qualident [ ParseConstructor
+                                                             |
+                                           SilentSimpleDes [ SilentActualParameters ]
+                                         ] |
+                                             ParseConstructor
                              )
+                                                                           % Assert (n = Top ()) %
                            =:
 
 -- SimpleDes := { "." Ident | "[" ExpList "]" | "^" } =:
@@ -1147,7 +1262,12 @@ AttributeUnused := [ "<*" Ident "*>" ] =:
 ProcedureBlock := { Declaration } [ "BEGIN" BlockBody ] "END"
                 =:
 
-Block := { Declaration } InitialBlock FinalBlock "END" =:
+Block :=                                                                   % VAR top: CARDINAL ; %
+                                                                           % top := Top () %
+         { Declaration }                                                   % BlockAssert (top = Top ()) %
+                         InitialBlock                                      % BlockAssert (top = Top ()) %
+                                      FinalBlock                           % BlockAssert (top = Top ()) %
+                                                 "END" =:
 
 InitialBlock := [ "BEGIN" BlockBody ] =:
 
diff --git a/gcc/m2/gm2-gcc/m2expr.cc b/gcc/m2/gm2-gcc/m2expr.cc
index c172039..ef8368a 100644
--- a/gcc/m2/gm2-gcc/m2expr.cc
+++ b/gcc/m2/gm2-gcc/m2expr.cc
@@ -939,7 +939,7 @@ m2expr_ConstantExpressionWarning (tree value)
    an overflow.  No error message or warning is emitted and no
    modification is made to, t.  */
 
-int
+bool
 m2expr_TreeOverflow (tree t)
 {
   if ((TREE_CODE (t) == INTEGER_CST
diff --git a/gcc/m2/gm2-gcc/m2expr.h b/gcc/m2/gm2-gcc/m2expr.h
index 64169c1..3701bcd 100644
--- a/gcc/m2/gm2-gcc/m2expr.h
+++ b/gcc/m2/gm2-gcc/m2expr.h
@@ -120,7 +120,7 @@ EXTERN tree m2expr_BuildTrunc (tree op1);
 EXTERN tree m2expr_BuildCoerce (location_t location, tree des, tree type,
                                 tree expr);
 EXTERN tree m2expr_RemoveOverflow (tree t);
-EXTERN int m2expr_TreeOverflow (tree t);
+EXTERN bool m2expr_TreeOverflow (tree t);
 
 EXTERN unsigned int m2expr_StringLength (tree string);
 EXTERN tree m2expr_FoldAndStrip (tree t);
@@ -220,11 +220,6 @@ EXTERN tree m2expr_GetWordOne (location_t location);
 EXTERN tree m2expr_GetPointerZero (location_t location);
 EXTERN tree m2expr_GetPointerOne (location_t location);
 
-#if 0
-EXTERN tree m2expr_GetBooleanTrue (void);
-EXTERN tree m2expr_GetBooleanFalse (void);
-#endif
-
 EXTERN int m2expr_CompareTrees (tree e1, tree e2);
 EXTERN tree m2expr_build_unary_op (location_t location ATTRIBUTE_UNUSED,
                                    enum tree_code code, tree arg,
diff --git a/gcc/m2/gm2-gcc/m2options.h b/gcc/m2/gm2-gcc/m2options.h
index bcec299..767b617 100644
--- a/gcc/m2/gm2-gcc/m2options.h
+++ b/gcc/m2/gm2-gcc/m2options.h
@@ -96,7 +96,7 @@ EXTERN bool M2Options_SetCpp (bool value);
 EXTERN void M2Options_SetSwig (bool value);
 EXTERN void M2Options_SetForcedLocation (location_t location);
 EXTERN location_t M2Options_OverrideLocation (location_t location);
-EXTERN void M2Options_SetStatistics (int on);
+EXTERN void M2Options_SetStatistics (bool on);
 EXTERN void M2Options_CppProg (const char *program);
 EXTERN void M2Options_CppArg (const char *opt, const char *arg, bool joined);
 EXTERN void M2Options_SetWholeProgram (bool value);