- fixed import bug (import "...")

- better debugging support
- removed dead code

R=r
OCL=13680
CL=13680

9 files changed, 156 insertions, 105 deletions

diff --git a/usr/gri/gosrc/compilation.go b/usr/gri/gosrc/compilation.go
index 33d5029e9..a7d1c9a1a 100644
--- a/usr/gri/gosrc/compilation.go
+++ b/usr/gri/gosrc/compilation.go
@@ -14,6 +14,7 @@ import AST "ast"
 import Parser "parser"
 import Export "export"
 import Printer "printer"
+import Verifier "verifier"
 
 
 export Compile
@@ -36,9 +37,15 @@ func Compile(comp *Globals.Compilation, file_name string) {
 		return;
 	}
 	
-	// export
-	if comp.flags.semantic_checks {
+	if !comp.flags.semantic_checks {
+		return;
+	}
+	
+	Verifier.Verify(comp);
+	
+	if comp.flags.print_export {
 		Printer.PrintObject(comp, comp.pkgs[0].obj, false);
-		Export.Export(comp, file_name);
 	}
+	
+	Export.Export(comp, file_name);
 }
diff --git a/usr/gri/gosrc/decls.go b/usr/gri/gosrc/decls.go
index f8e70d5ff..37b261e3b 100755
--- a/usr/gri/gosrc/decls.go
+++ b/usr/gri/gosrc/decls.go
@@ -6,7 +6,7 @@
 
 package decls
 
-// import "base"  // this fails
+import "base"
 import base "base"
 import base2 "base"
 
diff --git a/usr/gri/gosrc/export.go b/usr/gri/gosrc/export.go
index 17e414586..441e68a61 100755
--- a/usr/gri/gosrc/export.go
+++ b/usr/gri/gosrc/export.go
@@ -15,7 +15,7 @@ type Exporter struct {
 	comp *Globals.Compilation;
 	debug bool;
 	buf [4*1024] byte;
-	pos int;
+	buf_pos int;
 	pkg_ref int;
 	type_ref int;
 };
@@ -27,8 +27,8 @@ func (E *Exporter) WritePackage(pkg *Globals.Package);
 
 
 func (E *Exporter) WriteByte(x byte) {
-	E.buf[E.pos] = x;
-	E.pos++;
+	E.buf[E.buf_pos] = x;
+	E.buf_pos++;
 	/*
 	if E.debug {
 		print " ", x;
@@ -71,7 +71,7 @@ func (E *Exporter) WriteObjectTag(tag int) {
 	}
 	E.WriteInt(tag);
 	if E.debug {
-		print "\nObj: ", tag;  // obj kind
+		print "\n", Object.KindStr(tag);
 	}
 }
 
@@ -79,10 +79,10 @@ func (E *Exporter) WriteObjectTag(tag int) {
 func (E *Exporter) WriteTypeTag(tag int) {
 	E.WriteInt(tag);
 	if E.debug {
-		if tag > 0 {
-			print "\nTyp ", E.type_ref, ": ", tag;  // type form
+		if tag >= 0 {
+			print " [T", tag, "]";  // type ref
 		} else {
-			print " [Typ ", -tag, "]";  // type ref
+			print "\nT", E.type_ref, ": ", Type.FormStr(-tag);
 		}
 	}
 }
@@ -91,23 +91,15 @@ func (E *Exporter) WriteTypeTag(tag int) {
 func (E *Exporter) WritePackageTag(tag int) {
 	E.WriteInt(tag);
 	if E.debug {
-		if tag > 0 {
-			print "\nPkg ", E.pkg_ref, ": ", tag;  // package no
+		if tag >= 0 {
+			print " [P", tag, "]";  // package ref
 		} else {
-			print " [Pkg ", -tag, "]";  // package ref
+			print "\nP", E.pkg_ref, ": ", -tag;  // package no
 		}
 	}
 }
 
 
-func (E *Exporter) WriteTypeField(fld *Globals.Object) {
-	if fld.kind != Object.VAR {
-		panic "fld.kind != Object.VAR";
-	}
-	E.WriteType(fld.typ);
-}
-
-
 func (E *Exporter) WriteScope(scope *Globals.Scope) {
 	if E.debug {
 		print " {";
@@ -118,7 +110,7 @@ func (E *Exporter) WriteScope(scope *Globals.Scope) {
 			E.WriteObject(p.obj);
 		}
 	}
-	E.WriteObjectTag(0);  // terminator
+	E.WriteObjectTag(Object.EOS);
 	
 	if E.debug {
 		print " }";
@@ -127,8 +119,8 @@ func (E *Exporter) WriteScope(scope *Globals.Scope) {
 
 
 func (E *Exporter) WriteObject(obj *Globals.Object) {
-	if obj == nil || !obj.exported {
-		panic "obj == nil || !obj.exported";
+	if !obj.exported {
+		panic "!obj.exported";
 	}
 
 	if obj.kind == Object.TYPE && obj.typ.obj == obj {
@@ -156,7 +148,6 @@ func (E *Exporter) WriteObject(obj *Globals.Object) {
 			E.WriteInt(0);  // should be the correct address/offset
 			
 		default:
-			print "obj.kind = ", obj.kind, "\n";
 			panic "UNREACHABLE";
 		}
 	}
@@ -164,19 +155,16 @@ func (E *Exporter) WriteObject(obj *Globals.Object) {
 
 
 func (E *Exporter) WriteType(typ *Globals.Type) {
-	if typ == nil {
-		panic "typ == nil";
-	}
-
 	if typ.ref >= 0 {
-		E.WriteTypeTag(-typ.ref);  // type already exported
+		E.WriteTypeTag(typ.ref);  // type already exported
 		return;
 	}
 
-	if typ.form <= 0 {
-		panic "typ.form <= 0";
+	if -typ.form >= 0 {
+		panic "-typ.form >= 0";  // conflict with ref numbers
 	}
-	E.WriteTypeTag(typ.form);
+	
+	E.WriteTypeTag(-typ.form);
 	typ.ref = E.type_ref;
 	E.type_ref++;
 
@@ -214,7 +202,6 @@ func (E *Exporter) WriteType(typ *Globals.Type) {
 		E.WriteType(typ.elt);
 
 	default:
-		print "typ.form = ", typ.form, "\n";
 		panic "UNREACHABLE";
 	}
 }
@@ -222,14 +209,15 @@ func (E *Exporter) WriteType(typ *Globals.Type) {
 
 func (E *Exporter) WritePackage(pkg *Globals.Package) {
 	if pkg.ref >= 0 {
-		E.WritePackageTag(-pkg.ref);  // package already exported
+		E.WritePackageTag(pkg.ref);  // package already exported
 		return;
 	}
 
-	if Object.PACKAGE <= 0 {
-		panic "Object.PACKAGE <= 0";
+	if -Object.PACKAGE >= 0 {
+		panic "-Object.PACKAGE >= 0";  // conflict with ref numbers
 	}
-	E.WritePackageTag(Object.PACKAGE);
+	
+	E.WritePackageTag(-Object.PACKAGE);
 	pkg.ref = E.pkg_ref;
 	E.pkg_ref++;
 
@@ -242,7 +230,7 @@ func (E *Exporter) WritePackage(pkg *Globals.Package) {
 func (E *Exporter) Export(comp* Globals.Compilation, file_name string) {
 	E.comp = comp;
 	E.debug = comp.flags.debug;
-	E.pos = 0;
+	E.buf_pos = 0;
 	E.pkg_ref = 0;
 	E.type_ref = 0;
 	
@@ -267,10 +255,10 @@ func (E *Exporter) Export(comp* Globals.Compilation, file_name string) {
 	E.WriteScope(pkg.scope);
 	
 	if E.debug {
-		print "\n(", E.pos, " bytes)\n";
+		print "\n(", E.buf_pos, " bytes)\n";
 	}
 	
-	data := string(E.buf)[0 : E.pos];
+	data := string(E.buf)[0 : E.buf_pos];
 	ok := sys.writefile(file_name, data);
 	
 	if !ok {
diff --git a/usr/gri/gosrc/globals.go b/usr/gri/gosrc/globals.go
index 6e872dfdb..34743551c 100644
--- a/usr/gri/gosrc/globals.go
+++ b/usr/gri/gosrc/globals.go
@@ -78,8 +78,10 @@ type Scope struct {
 export Flags;
 type Flags struct {
 	debug bool;
+	print_export bool;
 	semantic_checks bool;
 	verbose int;
+	sixg bool;
 }
 
 
@@ -102,7 +104,7 @@ func NewObject(pos, kind int, ident string) *Object {
 	obj.pos = pos;
 	obj.kind = kind;
 	obj.ident = ident;
-	obj.typ = nil;  // Universe::undef_t;
+	obj.typ = nil;  // Universe::undef_t;  (cyclic import...)
 	obj.pnolev = 0;
 	return obj;
 }
diff --git a/usr/gri/gosrc/go.go b/usr/gri/gosrc/go.go
index 85b4a9fec..31f1b87c5 100644
--- a/usr/gri/gosrc/go.go
+++ b/usr/gri/gosrc/go.go
@@ -18,9 +18,11 @@ func PrintHelp() {
   print "usage:\n";
   print "  go { flag | file }\n";
   print "  -d  print debug information\n";
+  print "  -p  print export\n";
   print "  -s  enable semantic checks\n";
   print "  -v  verbose mode\n";
   print "  -vv  very verbose mode\n";
+  print "  -6g  6g compatibility mode\n";
 }
 
 
@@ -36,9 +38,11 @@ func main() {
 	for i := 1; i < sys.argc(); i++ {
 		switch arg := sys.argv(i); arg {
 		case "-d": flags.debug = true;
+		case "-p": flags.print_export = true;
 		case "-s": flags.semantic_checks = true;
 		case "-v": flags.verbose = 1;
 		case "-vv": flags.verbose = 2;
+		case "-6g": flags.sixg = true;
 		default: files.AddStr(arg);
 		}
 	}
diff --git a/usr/gri/gosrc/import.go b/usr/gri/gosrc/import.go
index 77b0f3050..66c6e2f91 100755
--- a/usr/gri/gosrc/import.go
+++ b/usr/gri/gosrc/import.go
@@ -15,11 +15,11 @@ type Importer struct {
 	comp *Globals.Compilation;
 	debug bool;
 	buf string;
-	pos int;
+	buf_pos int;
 	pkgs [256] *Globals.Package;
-	npkgs int;
+	pkg_ref int;
 	types [1024] *Globals.Type;
-	ntypes int;
+	type_ref int;
 };
 
 
@@ -29,8 +29,8 @@ func (I *Importer) ReadPackage() *Globals.Package;
 
 
 func (I *Importer) ReadByte() byte {
-	x := I.buf[I.pos];
-	I.pos++;
+	x := I.buf[I.buf_pos];
+	I.buf_pos++;
 	/*
 	if E.debug {
 		print " ", x;
@@ -80,7 +80,7 @@ func (I *Importer) ReadObjectTag() int {
 		panic "tag < 0";
 	}
 	if I.debug {
-		print "\nObj: ", tag;  // obj kind
+		print "\n", Object.KindStr(tag);
 	}
 	return tag;
 }
@@ -89,10 +89,10 @@ func (I *Importer) ReadObjectTag() int {
 func (I *Importer) ReadTypeTag() int {
 	tag := I.ReadInt();
 	if I.debug {
-		if tag > 0 {
-			print "\nTyp ", I.ntypes, ": ", tag;  // type form
+		if tag >= 0 {
+			print " [T", tag, "]";  // type ref
 		} else {
-			print " [Typ ", -tag, "]";  // type ref
+			print "\nT", I.type_ref, ": ", Type.FormStr(-tag);
 		}
 	}
 	return tag;
@@ -102,23 +102,16 @@ func (I *Importer) ReadTypeTag() int {
 func (I *Importer) ReadPackageTag() int {
 	tag := I.ReadInt();
 	if I.debug {
-		if tag > 0 {
-			print "\nPkg ", I.npkgs, ": ", tag;  // package tag
+		if tag >= 0 {
+			print " [P", tag, "]";  // package ref
 		} else {
-			print " [Pkg ", -tag, "]";  // package ref
+			print "\nP", I.pkg_ref, ": ", -tag;  // package tag
 		}
 	}
 	return tag;
 }
 
 
-func (I *Importer) ReadTypeField() *Globals.Object {
-	fld := Globals.NewObject(0, Object.VAR, "");
-	fld.typ = I.ReadType();
-	return fld;
-}
-
-
 func (I *Importer) ReadScope() *Globals.Scope {
 	if I.debug {
 		print " {";
@@ -127,7 +120,7 @@ func (I *Importer) ReadScope() *Globals.Scope {
 	scope := Globals.NewScope(nil);
 	for {
 		tag := I.ReadObjectTag();
-		if tag == 0 {
+		if tag == Object.EOS {  // terminator
 			break;
 		}
 		// InsertImport only needed for package scopes
@@ -159,12 +152,6 @@ func (I *Importer) ReadObject(tag int) *Globals.Object {
 		obj.pnolev = I.ReadPackage().obj.pnolev;
 
 		switch (tag) {
-		default: fallthrough;
-		case Object.BAD: fallthrough;
-		case Object.PACKAGE: fallthrough;
-		case Object.PTYPE:
-			panic "UNREACHABLE";
-
 		case Object.CONST:
 			I.ReadInt();  // should set the value field
 
@@ -176,6 +163,9 @@ func (I *Importer) ReadObject(tag int) *Globals.Object {
 
 		case Object.FUNC:
 			I.ReadInt();  // should set the address/offset field
+			
+		default:
+			panic "UNREACHABLE";
 		}
 
 		return obj;
@@ -186,14 +176,14 @@ func (I *Importer) ReadObject(tag int) *Globals.Object {
 func (I *Importer) ReadType() *Globals.Type {
 	tag := I.ReadTypeTag();
 
-	if tag <= 0 {
-		return I.types[-tag];  // type already imported
+	if tag >= 0 {
+		return I.types[tag];  // type already imported
 	}
 
-	typ := Globals.NewType(tag);
+	typ := Globals.NewType(-tag);
 	ptyp := typ;  // primary type
 	ident := I.ReadString();
-	if (len(ident) > 0) {
+	if len(ident) > 0 {
 		// primary type
 		obj := Globals.NewObject(0, Object.TYPE, ident);
 		obj.typ = typ;
@@ -206,22 +196,11 @@ func (I *Importer) ReadType() *Globals.Type {
 
 		ptyp = obj.typ;
 	}
-	I.types[I.ntypes] = ptyp;
-	I.ntypes++;
+	I.types[I.type_ref] = ptyp;
+	I.type_ref++;
 
-	switch (tag) {
+	switch (typ.form) {
 	default: fallthrough;
-	case Type.UNDEF: fallthrough;
-	case Type.BAD: fallthrough;
-	case Type.NIL: fallthrough;
-	case Type.BOOL: fallthrough;
-	case Type.UINT: fallthrough;
-	case Type.INT: fallthrough;
-	case Type.FLOAT: fallthrough;
-	case Type.STRING: fallthrough;
-	case Type.ANY:
-		panic "UNREACHABLE";
-
 	case Type.ARRAY:
 		typ.len_ = I.ReadInt();
 		typ.elt = I.ReadType();
@@ -243,6 +222,9 @@ func (I *Importer) ReadType() *Globals.Type {
 
 	case Type.POINTER, Type.REFERENCE:
 		typ.elt = I.ReadType();
+
+	default:
+		panic "UNREACHABLE";
 	}
 
 	return ptyp;  // only use primary type
@@ -252,10 +234,14 @@ func (I *Importer) ReadType() *Globals.Type {
 func (I *Importer) ReadPackage() *Globals.Package {
 	tag := I.ReadPackageTag();
 
-	if (tag <= 0) {
-		return I.pkgs[-tag];  // package already imported
+	if tag >= 0 {
+		return I.pkgs[tag];  // package already imported
 	}
 
+	if -tag != Object.PACKAGE {
+		panic "incorrect package tag";
+	}
+	
 	ident := I.ReadString();
 	file_name := I.ReadString();
 	key := I.ReadString();
@@ -268,12 +254,12 @@ func (I *Importer) ReadPackage() *Globals.Package {
 		pkg.scope = Globals.NewScope(nil);
 		pkg = I.comp.InsertImport(pkg);
 
-	} else if (key != pkg.key) {
+	} else if key != pkg.key {
 		// package inconsistency
 		panic "package key inconsistency";
 	}
-	I.pkgs[I.npkgs] = pkg;
-	I.npkgs++;
+	I.pkgs[I.pkg_ref] = pkg;
+	I.pkg_ref++;
 
 	return pkg;
 }
@@ -283,9 +269,9 @@ func (I *Importer) Import(comp* Globals.Compilation, file_name string) *Globals.
 	I.comp = comp;
 	I.debug = comp.flags.debug;
 	I.buf = "";
-	I.pos = 0;
-	I.npkgs = 0;
-	I.ntypes = 0;
+	I.buf_pos = 0;
+	I.pkg_ref = 0;
+	I.type_ref = 0;
 	
 	if I.debug {
 		print "importing from ", file_name, "\n";
@@ -299,17 +285,17 @@ func (I *Importer) Import(comp* Globals.Compilation, file_name string) *Globals.
 	
 	// Predeclared types are "pre-imported".
 	for p := Universe.types.first; p != nil; p = p.next {
-		if p.typ.ref != I.ntypes {
+		if p.typ.ref != I.type_ref {
 			panic "incorrect ref for predeclared type";
 		}
-		I.types[I.ntypes] = p.typ;
-		I.ntypes++;
+		I.types[I.type_ref] = p.typ;
+		I.type_ref++;
 	}
 
 	pkg := I.ReadPackage();
 	for {
 		tag := I.ReadObjectTag();
-		if tag == 0 {
+		if tag == Object.EOS {
 			break;
 		}
 		obj := I.ReadObject(tag);
@@ -318,7 +304,7 @@ func (I *Importer) Import(comp* Globals.Compilation, file_name string) *Globals.
 	}
 
 	if I.debug {
-		print "\n(", I.pos, " bytes)\n";
+		print "\n(", I.buf_pos, " bytes)\n";
 	}
 	
 	return pkg;
diff --git a/usr/gri/gosrc/object.go b/usr/gri/gosrc/object.go
index bef5fbcee..aab80cc57 100755
--- a/usr/gri/gosrc/object.go
+++ b/usr/gri/gosrc/object.go
@@ -7,14 +7,32 @@ package Object
 import Globals "globals"
 
 
-export BAD, CONST, TYPE, VAR, FUNC, PACKAGE, LABEL, PTYPE
+export BAD, CONST, TYPE, VAR, FUNC, PACKAGE, LABEL, PTYPE, EOS
 const /* kind */ (
 	BAD = iota;  // error handling
 	CONST; TYPE; VAR; FUNC; PACKAGE; LABEL;
 	PTYPE;  // primary type (import/export only)
+	EOS;  // end of scope (import/export only)
 )
 
 
 // The 'Object' declaration should be here as well, but 6g cannot handle
 // this due to cross-package circular references. For now it's all in
 // globals.go.
+
+
+export KindStr
+func KindStr(kind int) string {
+	switch kind {
+	case BAD: return "BAD";
+	case CONST: return "CONST";
+	case TYPE: return "TYPE";
+	case VAR: return "VAR";
+	case FUNC: return "FUNC";
+	case PACKAGE: return "PACKAGE";
+	case LABEL: return "LABEL";
+	case PTYPE: return "PTYPE";
+	case EOS: return "EOS";
+	}
+	return "<unknown Object kind>";
+}
diff --git a/usr/gri/gosrc/parser.go b/usr/gri/gosrc/parser.go
index d12ce764e..45b529dd5 100644
--- a/usr/gri/gosrc/parser.go
+++ b/usr/gri/gosrc/parser.go
@@ -27,7 +27,7 @@ type Parser struct {
 	val string;  // token value (for IDENT, NUMBER, STRING only)
 
 	// Semantic analysis
-	level int;  // 0 = global scope, -1 = function scope of global functions, etc.
+	level int;  // 0 = global scope, -1 = function/struct scope of global functions/structs, etc.
 	top_scope *Globals.Scope;
 	undef_types *Globals.List;
 	exports *Globals.List;
@@ -486,6 +486,7 @@ func (P *Parser) ParseAnonymousSignature() *Globals.Type {
 	P.Trace("AnonymousSignature");
 	
 	P.OpenScope();
+	P.level--;
 	sig := P.top_scope;
 	p0 := 0;
 	
@@ -505,6 +506,7 @@ func (P *Parser) ParseAnonymousSignature() *Globals.Type {
 	
 	r0 := sig.entries.len_;
 	P.TryResult();
+	P.level++;
 	P.CloseScope();
 	
 	P.Ecart();
@@ -525,6 +527,7 @@ func (P *Parser) ParseNamedSignature() (name string, typ *Globals.Type) {
 	P.Trace("NamedSignature");
 	
 	P.OpenScope();
+	P.level--;
 	sig := P.top_scope;
 	p0 := 0;
 
@@ -546,6 +549,7 @@ func (P *Parser) ParseNamedSignature() (name string, typ *Globals.Type) {
 	
 	r0 := sig.entries.len_;
 	P.TryResult();
+	P.level++;
 	P.CloseScope();
 	
 	P.Ecart();
@@ -569,11 +573,13 @@ func (P *Parser) ParseMethodDecl() {
 	
 	P.ParseIdent();
 	P.OpenScope();
+	P.level--;
 	sig := P.top_scope;
 	p0 := 0;
 	P.ParseParameters();
 	r0 := sig.entries.len_;
 	P.TryResult();
+	P.level++;
 	P.CloseScope();
 	P.Optional(Scanner.SEMICOLON);
 	
@@ -587,11 +593,13 @@ func (P *Parser) ParseInterfaceType() *Globals.Type {
 	P.Expect(Scanner.INTERFACE);
 	P.Expect(Scanner.LBRACE);
 	P.OpenScope();
+	P.level--;
 	typ := Globals.NewType(Type.INTERFACE);
 	typ.scope = P.top_scope;
 	for P.tok == Scanner.IDENT {
 		P.ParseMethodDecl();
 	}
+	P.level++;
 	P.CloseScope();
 	P.Expect(Scanner.RBRACE);
 	
@@ -628,6 +636,7 @@ func (P *Parser) ParseStructType() *Globals.Type {
 	P.Expect(Scanner.STRUCT);
 	P.Expect(Scanner.LBRACE);
 	P.OpenScope();
+	P.level--;
 	typ := Globals.NewType(Type.STRUCT);
 	typ.scope = P.top_scope;
 	for P.tok == Scanner.IDENT {
@@ -637,6 +646,7 @@ func (P *Parser) ParseStructType() *Globals.Type {
 		}
 	}
 	P.Optional(Scanner.SEMICOLON);
+	P.level++;
 	P.CloseScope();
 	P.Expect(Scanner.RBRACE);
 	
@@ -745,8 +755,12 @@ func (P *Parser) ParseBlock(sig *Globals.Scope) {
 	if sig != nil {
 		P.level--;
 		// add function parameters to scope
+		// TODO do we need to make a copy? what if we change obj fields?
 		scope := P.top_scope;
 		for p := sig.entries.first; p != nil; p = p.next {
+			if p.obj.pnolev != P.level {
+				panic "incorrect level";
+			}
 			scope.Insert(p.obj)
 		}
 	}
@@ -1560,12 +1574,13 @@ func (P *Parser) ParseImportSpec() {
 		pkg_name := P.val[1 : len(P.val) - 1];  // strip quotes
 		pkg := Import.Import(P.comp, pkg_name);
 		if pkg != nil {
+			pno := pkg.obj.pnolev;  // preserve pno
 			if obj == nil {
 				// use original package name
 				obj = pkg.obj;
-				P.Declare(obj);
+				P.Declare(obj);  // this changes (pkg.)obj.pnolev!
 			}
-			obj.pnolev = pkg.obj.pnolev;
+			obj.pnolev = pno;  // correct pno
 		} else {
 			P.Error(P.pos, `import of "` + pkg_name + `" failed`);
 		}
@@ -1836,7 +1851,10 @@ func (P *Parser) ParseProgram() {
 	}
 	P.Optional(Scanner.SEMICOLON);
 	
-	{	P.OpenScope();
+	{	if P.level != 0 {
+			panic "incorrect scope level";
+		}
+		P.OpenScope();
 		pkg.scope = P.top_scope;
 		for P.tok == Scanner.IMPORT {
 			P.ParseDecl(false, Scanner.IMPORT);
@@ -1851,6 +1869,9 @@ func (P *Parser) ParseProgram() {
 		P.ResolveUndefTypes();
 		P.MarkExports();
 		P.CloseScope();
+		if P.level != 0 {
+			panic "incorrect scope level";
+		}
 	}
 	
 	P.CloseScope();
diff --git a/usr/gri/gosrc/type.go b/usr/gri/gosrc/type.go
index f46f58d00..ea0877990 100644
--- a/usr/gri/gosrc/type.go
+++ b/usr/gri/gosrc/type.go
@@ -34,3 +34,28 @@ const /* flag */ (
 // The 'Type' declaration should be here as well, but 6g cannot handle
 // this due to cross-package circular references. For now it's all in
 // globals.go.
+
+
+export FormStr
+func FormStr(form int) string {
+	switch form {
+	case UNDEF: return "UNDEF";
+	case BAD: return "BAD";
+	case NIL: return "NIL";
+	case BOOL: return "BOOL";
+	case UINT: return "UINT";
+	case INT: return "INT";
+	case FLOAT: return "FLOAT";
+	case STRING: return "STRING";
+	case ANY: return "ANY";
+	case ARRAY: return "ARRAY";
+	case STRUCT: return "STRUCT";
+	case INTERFACE: return "INTERFACE";
+	case MAP: return "MAP";
+	case CHANNEL: return "CHANNEL";
+	case FUNCTION: return "FUNCTION";
+	case POINTER: return "POINTER";
+	case REFERENCE: return "REFERENCE";
+	}
+	return "<unknown Type form>";
+}