- more steps towards automatic recursive compilation of dependencies

- make forward declarations of types match 6g
- better factoring

R=r
OCL=14059
CL=14059

usr/gri/gosrc/compilation.go

@@ -4,6 +4,7 @@
 
 package Compilation
 
+import Platform "platform"
 import Utils "utils"
 import Globals "globals"
 import Object "object"
@@ -12,16 +13,77 @@ import Universe "universe"
 import Scanner "scanner"
 import AST "ast"
 import Parser "parser"
-import Export "export"
+import Importer "import"
+import Exporter "export"
 import Printer "printer"
 import Verifier "verifier"
 
 
-export func Compile(flags *Globals.Flags, filename string) {
+func ReadImport(comp* Globals.Compilation, filename string, update bool) (data string, ok bool) {
+	if filename == "" {
+		panic "illegal package file name";
+	}
+
+	// see if it just works
+	data, ok = Platform.ReadObjectFile(filename);
+	if ok {
+		return data, ok;
+	}
+	
+	if filename[0] == '/' {
+		// absolute path
+		panic `don't know how to handle absolute import file path "` + filename + `"`;
+	}
+	
+	// relative path
+	// try relative to the $GOROOT/pkg directory
+	std_filename := Platform.GOROOT + "/pkg/" + filename;
+	data, ok = Platform.ReadObjectFile(std_filename);
+	if ok {
+		return data, ok;
+	}
+	
+	if !update {
+		return "", false;
+	}
+	
+	// TODO BIG HACK - fix this!
+	// look for a src file
+	// see if it just works
+	data, ok = Platform.ReadSourceFile(filename);
+	if ok {
+		comp.env.Compile(comp.flags, comp.env, filename + Platform.src_file_ext);
+		data, ok = ReadImport(comp, filename, false);
+		if ok {
+			return data, ok;
+		}
+	}
+	
+	return "", false;
+}
+
+
+export func Import(comp *Globals.Compilation, pkg_file string) *Globals.Package {
+	data, ok := ReadImport(comp, pkg_file, comp.flags.update_packages)
+	var pkg *Globals.Package;
+	if ok {
+		pkg = Importer.Import(comp, data);
+	}
+	return pkg;
+}
+
+
+export func Export(comp *Globals.Compilation) string {
+	panic "UNIMPLEMENTED";
+	return "";
+}
+
+
+export func Compile(flags *Globals.Flags, env* Globals.Environment, filename string) {
 	// setup compilation
 	comp := new(Globals.Compilation);
 	comp.flags = flags;
-	comp.Compile = &Compile;
+	comp.env = env;
 	
 	src, ok := sys.readfile(filename);
 	if !ok {
@@ -29,8 +91,10 @@ export func Compile(flags *Globals.Flags, filename string) {
 		return;
 	}
 	
-	print filename, "\n";
-	
+	if flags.verbosity > 0 {
+		print filename, "\n";
+	}
+
 	scanner := new(Scanner.Scanner);
 	scanner.Open(filename, src);
 	
@@ -58,5 +122,5 @@ export func Compile(flags *Globals.Flags, filename string) {
 		Printer.PrintObject(comp, comp.pkg_list[0].obj, false);
 	}
 	
-	Export.Export(comp, filename);
+	Exporter.Export(comp, filename);
 }

usr/gri/gosrc/decls.go

@@ -65,8 +65,7 @@ type T9 struct {
 	f *func(x, y *T9) *T9;
 }
 
-type T10;
-type T11 struct {
+export type T11 struct {
 	p *T10;
 }
 
@@ -78,7 +77,6 @@ type T12 struct {
 	p *T12
 }
 
-
 type I0 interface {}
 type I1 interface {
 	Do0(q *I0);
@@ -124,3 +122,9 @@ func (p *T4) m4(a int) (z T5, ok bool) { return; }
 func (p *T4) m5(a, b int, c float) (z T5, ok bool) {
 	L: var x = a;
 }
+
+
+func f2() {
+	type T *T14;
+}
+type T14 int;

usr/gri/gosrc/export.go

@@ -4,6 +4,7 @@
 
 package Exporter
 
+import Platform "platform"
 import Utils "utils"
 import Globals "globals"
 import Object "object"
@@ -248,7 +249,7 @@ func (E *Exporter) Export(comp* Globals.Compilation, file_name string) {
 	}
 
 	// write magic bits
-	magic := Globals.MAGIC_obj_file;  // TODO remove once len(constant) works
+	magic := Platform.MAGIC_obj_file;  // TODO remove once len(constant) works
 	for i := 0; i < len(magic); i++ {
 		E.WriteByte(magic[i]);
 	}
@@ -283,7 +284,51 @@ func (E *Exporter) Export(comp* Globals.Compilation, file_name string) {
 }
 
 
+func (E *Exporter) Export2(comp* Globals.Compilation) string {
+	E.comp = comp;
+	E.debug = comp.flags.debug;
+	E.buf_pos = 0;
+	E.pkg_ref = 0;
+	E.type_ref = 0;
+	
+	// write magic bits
+	magic := Platform.MAGIC_obj_file;  // TODO remove once len(constant) works
+	for i := 0; i < len(magic); i++ {
+		E.WriteByte(magic[i]);
+	}
+	
+	// Predeclared types are "pre-exported".
+	// TODO run the loop below only in debug mode
+	{	i := 0;
+		for p := Universe.types.first; p != nil; p = p.next {
+			if p.typ.ref != i {
+				panic "incorrect ref for predeclared type";
+			}
+			i++;
+		}
+	}
+	E.type_ref = Universe.types.len_;
+	
+	// export package 0
+	pkg := comp.pkg_list[0];
+	E.WritePackage(pkg);
+	E.WriteScope(pkg.scope);
+	
+	if E.debug {
+		print "\n(", E.buf_pos, " bytes)\n";
+	}
+	
+	return string(E.buf)[0 : E.buf_pos];
+}
+
+
 export func Export(comp* Globals.Compilation, pkg_name string) {
 	var E Exporter;
-	(&E).Export(comp, Utils.TrimExt(Utils.BaseName(pkg_name), Globals.src_file_ext) + Globals.obj_file_ext);
+	(&E).Export(comp, Utils.TrimExt(Utils.BaseName(pkg_name), Platform.src_file_ext) + Platform.obj_file_ext);
+}
+
+
+export func Export2(comp* Globals.Compilation) string {
+	var E Exporter;
+	return (&E).Export2(comp);
 }

usr/gri/gosrc/globals.go

@@ -5,18 +5,6 @@
 package Globals
 
 
-// ----------------------------------------------------------------------------
-// Constants
-
-export const (
-	MAGIC_obj_file = "/*go.7*/";  // anything, really
-	src_file_ext = ".go";
-	obj_file_ext = ".7";
-)
-
-
-// ----------------------------------------------------------------------------
-
 // The following types should really be in their respective files
 // (object.go, type.go, scope.go, package.go, compilation.go, etc.) but
 // they refer to each other and we don't know how to handle forward
@@ -44,7 +32,7 @@ export type Type struct {
 	obj *Object;  // primary type object or NULL
 	aux *Type;  // alias base type or map key
 	elt *Type;  // aliases, arrays, maps, channels, pointers
-	scope *Scope;  // structs, interfaces, functions
+	scope *Scope;  // forwards, structs, interfaces, functions
 }
 
 
@@ -72,7 +60,7 @@ export type Scope struct {
 
 export type Flags struct {
 	debug bool;
-	object_filename string;
+	object_file string;
 	update_packages bool;
 	print_interface bool;
 	verbosity uint;
@@ -86,13 +74,18 @@ export type Flags struct {
 }
 
 
-export type Compilation struct {
-	// envionment
-	flags *Flags;
+export type Environment struct {
 	Error *func(comp *Compilation);  // TODO complete this
-	Import *func(comp *Compilation, data string) *Package;
+	Import *func(comp *Compilation, pkg_file string) *Package;
 	Export *func(comp *Compilation) string;
-    Compile *func(flags *Flags, filename string);  // TODO remove this eventually
+	Compile *func(flags *Flags, env* Environment, file string);
+}
+
+
+export type Compilation struct {
+	// environment
+	flags *Flags;
+	env *Environment;
 	
 	// TODO use open arrays eventually
 	pkg_list [256] *Package;  // pkg_list[0] is the current package
@@ -128,7 +121,7 @@ type Elem struct {
 // ----------------------------------------------------------------------------
 // Creation
 
-export var Universe_undef_t *Type  // initialized by Universe to Universe.undef_t
+export var Universe_void_t *Type  // initialized by Universe to Universe.void_t
 
 export func NewObject(pos, kind int, ident string) *Object {
 	obj := new(Object);
@@ -136,7 +129,7 @@ export func NewObject(pos, kind int, ident string) *Object {
 	obj.pos = pos;
 	obj.kind = kind;
 	obj.ident = ident;
-	obj.typ = Universe_undef_t;
+	obj.typ = Universe_void_t;
 	obj.pnolev = 0;
 	return obj;
 }

usr/gri/gosrc/go.go

@@ -15,7 +15,7 @@ func PrintHelp() {
 		"usage:\n" +
 		"  go { flag } { file }\n" +
 		"  -d             debug mode, additional self tests and prints\n" +
-		"  -o filename    explicit object filename\n" +
+		"  -o file        explicit object file\n" +
 		"  -r             recursively update imported packages in current directory\n" +
 		"  -p             print package interface\n" +
 		"  -v [0 .. 3]    verbosity level\n" +
@@ -53,7 +53,7 @@ func main() {
 	for arg != "" {
 	    switch arg {
 		case "-d": flags.debug = true;
-		case "-o": flags.object_filename = Next();
+		case "-o": flags.object_file = Next();
 			print "note: -o flag ignored at the moment\n";
 		case "-r": flags.update_packages = true;
 		case "-p": flags.print_interface = true;
@@ -81,8 +81,14 @@ func main() {
 		arg = Next();
 	}
 	
+	// setup environment
+	env := new(Globals.Environment);
+	env.Import = &Compilation.Import;
+	env.Export = &Compilation.Export;
+	env.Compile = &Compilation.Compile;
+	
 	// compile files
 	for p := files.first; p != nil; p = p.next {
-		Compilation.Compile(flags, p.str);
+		Compilation.Compile(flags, env, p.str);
 	}
 }

usr/gri/gosrc/import.go

@@ -4,6 +4,7 @@
 
 package Importer
 
+import Platform "platform"
 import Utils "utils"
 import Globals "globals"
 import Object "object"
@@ -128,6 +129,9 @@ func (I *Importer) ReadPackage() *Globals.Package {
 		obj := Globals.NewObject(-1, Object.PACKAGE, ident);
 		pkg = Globals.NewPackage(file_name, obj, Globals.NewScope(nil));
 		I.comp.Insert(pkg);
+		if I.comp.flags.verbosity > 1 {
+			print `import: implicitly adding package `, ident, ` "`, file_name, `" (pno = `, obj.pnolev, ")\n";
+		}
 	} else if key != pkg.key {
 		// the package was imported before but the package
 		// key has changed
@@ -264,84 +268,18 @@ func (I *Importer) ReadObject() *Globals.Object {
 }
 
 
-func ReadObjectFile(filename string) (data string, ok bool) {
-	data, ok = sys.readfile(filename + Globals.obj_file_ext);
-	magic := Globals.MAGIC_obj_file;  // TODO remove once len(constant) works
-	if ok && len(data) >= len(magic) && data[0 : len(magic)] == magic {
-		return data, ok;
-	}
-	return "", false;
-}
-
-
-func ReadSourceFile(filename string) (data string, ok bool) {
-	data, ok = sys.readfile(filename + Globals.src_file_ext);
-	return data, ok;
-}
-
-
-func ReadImport(comp* Globals.Compilation, filename string, update bool) (data string, ok bool) {
-	if filename == "" {
-		panic "illegal package file name";
-	}
-
-	// see if it just works
-	data, ok = ReadObjectFile(filename);
-	if ok {
-		return data, ok;
-	}
-	
-	if filename[0] == '/' {
-		// absolute path
-		panic `don't know how to handle absolute import file path "` + filename + `"`;
-	}
-	
-	// relative path
-	// try relative to the $GOROOT/pkg directory
-	std_filename := Utils.GOROOT + "/pkg/" + filename;
-	data, ok = ReadObjectFile(std_filename);
-	if ok {
-		return data, ok;
-	}
-	
-	if !update {
-		return "", false;
-	}
-	
-	// TODO BIG HACK - fix this!
-	// look for a src file
-	// see if it just works
-	data, ok = ReadSourceFile(filename);
-	if ok {
-		comp.Compile(comp.flags, filename + Globals.src_file_ext);
-		data, ok = ReadImport(comp, filename, false);
-		if ok {
-			return data, ok;
-		}
-	}
-	
-	return "", false;
-}
-
-
-func (I *Importer) Import(comp* Globals.Compilation, file_name string) *Globals.Package {
+func (I *Importer) Import(comp* Globals.Compilation, data string) *Globals.Package {
 	I.comp = comp;
 	I.debug = comp.flags.debug;
-	I.buf = "";
+	I.buf = data;
 	I.buf_pos = 0;
 	I.pkg_ref = 0;
 	I.type_ref = 0;
 	
-	if I.debug {
-		print "importing from ", file_name, "\n";
-	}
-	
-	//  read file and check magic bits
-	buf, ok := ReadImport(comp, file_name, comp.flags.update_packages);
-	if !ok {
+	// check magic bits
+	if !Utils.Contains(data, Platform.MAGIC_obj_file, 0) {
 		return nil;
 	}
-	I.buf = buf;
 	
 	// Predeclared types are "pre-imported".
 	for p := Universe.types.first; p != nil; p = p.next {
@@ -364,7 +302,8 @@ func (I *Importer) Import(comp* Globals.Compilation, file_name string) *Globals.
 }
 
 
-export func Import(comp* Globals.Compilation, pkg_name string) *Globals.Package {
+export func Import(comp *Globals.Compilation, data string) *Globals.Package {
 	var I Importer;
-	return (&I).Import(comp, pkg_name);
+	pkg := (&I).Import(comp, data);
+	return pkg;
 }

usr/gri/gosrc/parser.go

@@ -17,7 +17,8 @@ import AST "ast"
 export type Parser struct {
 	comp *Globals.Compilation;
 	semantic_checks bool;
-	verbose, indent uint;
+	verbose bool;
+	indent uint;
 	S *Scanner.Scanner;
 	C *chan *Scanner.Token;
 	
@@ -29,7 +30,7 @@ export type Parser struct {
 	// Semantic analysis
 	level int;  // 0 = global scope, -1 = function/struct scope of global functions/structs, etc.
 	top_scope *Globals.Scope;
-	undef_types *Globals.List;
+	forward_types *Globals.List;
 	exports *Globals.List;
 }
 
@@ -45,7 +46,7 @@ func (P *Parser) PrintIndent() {
 
 
 func (P *Parser) Trace(msg string) {
-	if P.verbose > 0 {
+	if P.verbose {
 		P.PrintIndent();
 		print msg, " {\n";
 	}
@@ -55,7 +56,7 @@ func (P *Parser) Trace(msg string) {
 
 func (P *Parser) Ecart() {
 	P.indent--;
-	if P.verbose > 0 {
+	if P.verbose {
 		P.PrintIndent();
 		print "}\n";
 	}
@@ -69,7 +70,7 @@ func (P *Parser) Next() {
 		t := <- P.C;
 		P.tok, P.pos, P.val = t.tok, t.pos, t.val;
 	}
-	if P.verbose > 1 {
+	if P.verbose {
 		P.PrintIndent();
 		print "[", P.pos, "] ", Scanner.TokenName(P.tok), "\n";
 	}
@@ -79,14 +80,14 @@ func (P *Parser) Next() {
 func (P *Parser) Open(comp *Globals.Compilation, S *Scanner.Scanner, C *chan *Scanner.Token) {
 	P.comp = comp;
 	P.semantic_checks = comp.flags.ast;
-	P.verbose = comp.flags.verbosity;
+	P.verbose = comp.flags.verbosity > 2;
 	P.indent = 0;
 	P.S = S;
 	P.C = C;
 	P.Next();
 	P.level = 0;
 	P.top_scope = Universe.scope;
-	P.undef_types = Globals.NewList();
+	P.forward_types = Globals.NewList();
 	P.exports = Globals.NewList();
 }
 
@@ -185,7 +186,7 @@ func MakeFunctionType(sig *Globals.Scope, p0, r0 int, check_recv bool) *Globals.
 }
 
 
-func (P *Parser) DeclareFunc(ident string, typ *Globals.Type) *Globals.Object {
+func (P *Parser) DeclareFunc(pos int, ident string, typ *Globals.Type) *Globals.Object {
 	// determine scope
 	scope := P.top_scope;
 	if typ.flags & Type.RECV != 0 {
@@ -203,7 +204,7 @@ func (P *Parser) DeclareFunc(ident string, typ *Globals.Type) *Globals.Object {
 	// declare the function
 	obj := scope.Lookup(ident);
 	if obj == nil {
-		obj = Globals.NewObject(-1, Object.FUNC, ident);
+		obj = Globals.NewObject(pos, Object.FUNC, ident);
 		obj.typ = typ;
 		// TODO do we need to set the primary type? probably...
 		P.DeclareInScope(scope, obj);
@@ -245,13 +246,14 @@ func (P *Parser) TryStatement() bool;
 func (P *Parser) ParseDeclaration();
 
 
-func (P *Parser) ParseIdent() string {
+func (P *Parser) ParseIdent() (pos int, ident string) {
 	P.Trace("Ident");
 
-	ident := "";
+	pos = P.pos;
+	ident = "";
 	if P.tok == Scanner.IDENT {
 		ident = P.val;
-		if P.verbose > 0 {
+		if P.verbose {
 			P.PrintIndent();
 			print "Ident = \"", ident, "\"\n";
 		}
@@ -261,15 +263,15 @@ func (P *Parser) ParseIdent() string {
 	}
 	
 	P.Ecart();
-	return ident;
+	return pos, ident;
 }
 
 
 func (P *Parser) ParseIdentDecl(kind int) *Globals.Object {
 	P.Trace("IdentDecl");
 	
-	pos := P.pos;
-	obj := Globals.NewObject(pos, kind, P.ParseIdent());
+	pos, ident := P.ParseIdent();
+	obj := Globals.NewObject(pos, kind, ident);
 	P.Declare(obj);
 	
 	P.Ecart();
@@ -307,8 +309,7 @@ func (P *Parser) ParseQualifiedIdent(pos int, ident string) *Globals.Object {
 	P.Trace("QualifiedIdent");
 
 	if pos < 0 {
-		pos = P.pos;
-		ident = P.ParseIdent();
+		pos, ident = P.ParseIdent();
 	}
 	
 	if P.semantic_checks {
@@ -327,8 +328,7 @@ func (P *Parser) ParseQualifiedIdent(pos int, ident string) *Globals.Object {
 			//	panic "pkg.obj.ident != ident";
 			//}
 			P.Next();  // consume "."
-			pos = P.pos;
-			ident = P.ParseIdent();
+			pos, ident = P.ParseIdent();
 			obj = pkg.scope.Lookup(ident);
 			if obj == nil {
 				P.Error(pos, `"` + ident + `" is not declared in package "` + pkg.obj.ident + `"`);
@@ -559,14 +559,14 @@ func (P *Parser) ParseAnonymousSignature() *Globals.Type {
 
 // Named signatures
 //
-//        name (params)
-//        name (params) type
-//        name (params) (results)
-// (recv) name (params)
-// (recv) name (params) type
-// (recv) name (params) (results)
-
-func (P *Parser) ParseNamedSignature() (name string, typ *Globals.Type) {
+//        ident (params)
+//        ident (params) type
+//        ident (params) (results)
+// (recv) ident (params)
+// (recv) ident (params) type
+// (recv) ident (params) (results)
+
+func (P *Parser) ParseNamedSignature() (pos int, ident string, typ *Globals.Type) {
 	P.Trace("NamedSignature");
 	
 	P.OpenScope();
@@ -586,7 +586,7 @@ func (P *Parser) ParseNamedSignature() (name string, typ *Globals.Type) {
 		}
 	}
 	
-	name = P.ParseIdent();
+	pos, ident = P.ParseIdent();
 
 	P.ParseParameters();
 	
@@ -596,7 +596,7 @@ func (P *Parser) ParseNamedSignature() (name string, typ *Globals.Type) {
 	P.CloseScope();
 	
 	P.Ecart();
-	return name, MakeFunctionType(sig, p0, r0, true);
+	return pos, ident, MakeFunctionType(sig, p0, r0, true);
 }
 
 
@@ -614,8 +614,7 @@ func (P *Parser) ParseFunctionType() *Globals.Type {
 func (P *Parser) ParseMethodDecl(recv_typ *Globals.Type) {
 	P.Trace("MethodDecl");
 	
-	pos := P.pos;
-	ident := P.ParseIdent();
+	pos, ident := P.ParseIdent();
 	P.OpenScope();
 	P.level--;
 	sig := P.top_scope;
@@ -715,39 +714,40 @@ func (P *Parser) ParsePointerType() *Globals.Type {
 	P.Expect(Scanner.MUL);
 	typ := Globals.NewType(Type.POINTER);
 	
-	if P.semantic_checks {
-		if P.tok == Scanner.IDENT {
-			if P.Lookup(P.val) == nil {
-				// implicit forward declaration
-				// TODO very problematic: in which scope should the
-				// type object be declared? It's different if this
-				// is inside a struct or say in a var declaration.
-				// This code is only here for "compatibility" with 6g.
-				pos := P.pos;
-				obj := Globals.NewObject(pos, Object.TYPE, P.ParseIdent());
-				obj.typ = Globals.NewType(Type.UNDEF);
-				obj.typ.obj = obj;  // primary type object
-				typ.elt = obj.typ;
-				// TODO obj should be declared, but scope is not clear
-			} else {
-				// type name
-				// (ParseType() doesn't permit incomplete types,
-				// so call ParseTypeName() here)
-				typ.elt = P.ParseTypeName();
-			}
+	var elt *Globals.Type;
+	if P.semantic_checks && P.tok == Scanner.IDENT {
+		if P.Lookup(P.val) == nil {
+			// implicit forward declaration
+			// create a named forward type 
+			pos, ident := P.ParseIdent();
+			obj := Globals.NewObject(pos, Object.TYPE, ident);
+			elt = Globals.NewType(Type.FORWARD);
+			obj.typ = elt;
+			elt.obj = obj;  // primary type object;
+			// remember the current scope - resolving the forward
+			// type must find a matching declaration in this or a less nested scope
+			elt.scope = P.top_scope;
+			
 		} else {
-			typ.elt = P.ParseType();
+			// type name
+			// (ParseType() (via TryType()) checks for forward types and complains,
+			// so call ParseTypeName() directly)
+			// we can only have a foward type here if we refer to the name of a
+			// yet incomplete type (i.e. if we are in the middle of a type's declaration)
+			elt = P.ParseTypeName();
 		}
-	
-		// collect undefined pointer types
-		if typ.elt.form == Type.UNDEF {
-			P.undef_types.AddTyp(typ);
+
+		// collect uses of pointer types referring to forward types
+		if elt.form == Type.FORWARD {
+			P.forward_types.AddTyp(typ);
 		}
 		
 	} else {
-		typ.elt = P.ParseType();
+		elt = P.ParseType();
 	}
 
+	typ.elt = elt;
+	
 	P.Ecart();
 	return typ;
 }
@@ -770,7 +770,7 @@ func (P *Parser) TryType() *Globals.Type {
 	case Scanner.MUL: typ = P.ParsePointerType();
 	}
 
-	if typ != nil && typ.form == Type.UNDEF {
+	if typ != nil && typ.form == Type.FORWARD {
 		P.Error(pos, "incomplete type");
 	}
 
@@ -1066,8 +1066,7 @@ func (P *Parser) ParseSelectorOrTypeAssertion(x Globals.Expr) Globals.Expr {
 	P.Expect(Scanner.PERIOD);
 	
 	if P.tok == Scanner.IDENT {
-		ident_pos := P.pos;
-		ident := P.ParseIdent();
+		ident_pos, ident := P.ParseIdent();
 		
 		if P.semantic_checks {
 			switch typ := x.typ(); typ.form {
@@ -1256,7 +1255,7 @@ func (P *Parser) ParseBinaryExpr(pos int, ident string, prec1 int) Globals.Expr
 	for prec := Precedence(P.tok); prec >= prec1; prec-- {
 		for Precedence(P.tok) == prec {
 			e := new(AST.BinaryExpr);
-			e.typ_ = Universe.undef_t;  // TODO fix this
+			e.typ_ = Universe.bad_t;  // TODO fix this
 			e.op = P.tok;  // TODO should we use tokens or separate operator constants?
 			e.x = x;
 			P.Next();
@@ -1745,7 +1744,9 @@ func (P *Parser) ParseImportSpec() {
 	if P.semantic_checks && P.tok == Scanner.STRING {
 		// TODO eventually the scanner should strip the quotes
 		pkg_name := P.val[1 : len(P.val) - 1];  // strip quotes
-		pkg := Import.Import(P.comp, pkg_name);
+		// TODO switch to indirect import once the compiler problems are fixed
+		//pkg := Import.Import(P.comp, pkg_name);
+		pkg := P.comp.env.Import(P.comp, pkg_name);
 		if pkg != nil {
 			pno := pkg.obj.pnolev;  // preserve pno
 			if obj == nil {
@@ -1794,55 +1795,48 @@ func (P *Parser) ParseConstSpec(exported bool) {
 
 func (P *Parser) ParseTypeSpec(exported bool) {
 	P.Trace("TypeSpec");
+
+	// Immediately after declaration of the type name, the type is
+	// considered forward-declared. It may be referred to from inside
+	// the type specification only via a pointer type.
+	typ := Globals.NewType(Type.FORWARD);
+	typ.scope = P.top_scope;  // not really needed here, but for consistency
 	
-	pos := P.pos;
-	ident := P.ParseIdent();
-	obj := P.top_scope.Lookup(ident);  // only lookup in top scope!
-	if obj != nil {
-		// name already declared - ok if forward declared type
-		if obj.kind != Object.TYPE || obj.typ.form != Type.UNDEF {
-			// TODO use obj.pos to refer to decl pos in error msg!
-			P.Error(pos, `"` + ident + `" is declared already`);
-		}
-	} else {
-		obj = Globals.NewObject(pos, Object.TYPE, ident);
-		obj.exported = exported;
-		obj.typ = Globals.NewType(Type.UNDEF);
-		obj.typ.obj = obj;  // primary type object
-		P.Declare(obj);
-	}
+	pos, ident := P.ParseIdent();
+	obj := Globals.NewObject(pos, Object.TYPE, ident);
+	obj.exported = exported;
+	obj.typ = typ;
+	typ.obj = obj;  // primary type object
+	P.Declare(obj);
 	
 	// If the next token is an identifier and we have a legal program,
 	// it must be a typename. In that case this declaration introduces
 	// an alias type.
-	make_alias := P.tok == Scanner.IDENT;
-	
-	// If we have an explicit forward declaration, TryType will not
-	// find a type and return nil.
-	typ := P.TryType();
-
-	if typ != nil {
-		if make_alias {
-			alias := Globals.NewType(Type.ALIAS);
-			if typ.form == Type.ALIAS {
-				alias.aux = typ.aux;  // the base type
-			} else {
-				alias.aux = typ;
-			}
-			alias.elt = typ;
-			typ = alias;
-		}
-		obj.typ = typ;
-		if typ.obj == nil {
-			typ.obj = obj;  // primary type object
+	if P.tok == Scanner.IDENT {
+		typ = Globals.NewType(Type.ALIAS);
+		elt := P.ParseType();  // we want a complete type - don't shortcut to ParseTypeName()
+		typ.elt = elt;
+		if elt.form == Type.ALIAS {
+			typ.aux = elt.aux;  // the base type
+		} else {
+			typ.aux = elt;
 		}
-		// if the type is exported, for now we export all fields
-		// of structs and interfaces by default
-		// TODO this needs to change eventually
-		if exported && (typ.form == Type.STRUCT || typ.form == Type.INTERFACE) {
-			for p := typ.scope.entries.first; p != nil; p = p.next {
-				p.obj.exported = true;
-			}
+	} else {
+		typ = P.ParseType();
+	}
+
+	obj.typ = typ;
+	if typ.obj == nil {
+		typ.obj = obj;  // primary type object
+	}
+	
+	// if the type is exported, for now we export all fields
+	// of structs and interfaces by default
+	// TODO this needs to change eventually
+	// Actually in 6g even types referred to are exported - sigh...
+	if exported && (typ.form == Type.STRUCT || typ.form == Type.INTERFACE) {
+		for p := typ.scope.entries.first; p != nil; p = p.next {
+			p.obj.exported = true;
 		}
 	}
 	
@@ -1916,8 +1910,8 @@ func (P *Parser) ParseFuncDecl(exported bool) {
 	P.Trace("FuncDecl");
 	
 	P.Expect(Scanner.FUNC);
-	ident, typ := P.ParseNamedSignature();
-	obj := P.DeclareFunc(ident, typ);  // need obj later for statements
+	pos, ident, typ := P.ParseNamedSignature();
+	obj := P.DeclareFunc(pos, ident, typ);  // need obj later for statements
 	obj.exported = exported;
 	if P.tok == Scanner.SEMICOLON {
 		// forward declaration
@@ -1947,7 +1941,8 @@ func (P *Parser) ParseExportDecl() {
 		has_paren = true;
 	}
 	for P.tok == Scanner.IDENT {
-		P.exports.AddStr(P.ParseIdent());
+		pos, ident := P.ParseIdent();
+		P.exports.AddStr(ident);
 		P.Optional(Scanner.COMMA);  // TODO this seems wrong
 	}
 	if has_paren {
@@ -2002,23 +1997,49 @@ func (P *Parser) ParseDeclaration() {
 // ----------------------------------------------------------------------------
 // Program
 
-func (P *Parser) ResolveUndefTypes() {
+func (P *Parser) ResolveForwardTypes() {
 	if !P.semantic_checks {
 		return;
 	}
 	
-	for p := P.undef_types.first; p != nil; p = p.next {
+	for p := P.forward_types.first; p != nil; p = p.next {
 		typ := p.typ;
 		if typ.form != Type.POINTER {
 			panic "unresolved types should be pointers only";
 		}
-		if typ.elt.form != Type.UNDEF {
-			panic "unresolved pointer should point to undefined type";
+		
+		elt := typ.elt;
+		if typ.elt.form != Type.FORWARD {
+			panic "unresolved pointer should point to forward type";
 		}
-		obj := typ.elt.obj;
+		
+		obj := elt.obj;
+		if obj.typ == elt {
+			// actual forward declaration (as opposed to forward types introduced
+			// during type declaration) - need to lookup the actual type object
+			var elt_obj *Globals.Object;
+			for scope := elt.scope; scope != nil && elt_obj == nil; scope = scope.parent {
+				elt_obj = scope.Lookup(obj.ident);
+			}
+			// update the type object if we found one
+			if elt_obj != nil {
+				if elt_obj.kind == Object.TYPE {
+					obj = elt_obj;
+				} else {
+					P.Error(obj.pos, `"` + obj.ident + `" does not denote a type`);
+				}
+			}
+		}
+
+		// update the pointer type
 		typ.elt = obj.typ;
-		if typ.elt.form == Type.UNDEF {
-			P.Error(obj.pos, `"` + obj.ident + `" is not declared`);
+		
+		// TODO as long as we don't *use* a forward type, we are ok
+		// => consider not reporting this as an error
+		// (in a real forward declaration, the corresponding objects are not in a scope
+		// and have incorrect pnolev)
+		if typ.elt.form == Type.FORWARD {
+			P.Error(obj.pos, `"` + obj.ident + `" is not declared after forward declaration`);
 		}
 	}
 }
@@ -2081,7 +2102,7 @@ func (P *Parser) ParseProgram() {
 			P.Optional(Scanner.SEMICOLON);
 		}
 		
-		P.ResolveUndefTypes();
+		P.ResolveForwardTypes();
 		P.MarkExports();
 		
 		if P.level != 0 {

usr/gri/gosrc/platform.go

+// Copyright 2009 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package Platform
+
+// ----------------------------------------------------------------------------
+// Environment
+
+export var
+	GOARCH,
+	GOOS,
+	GOROOT,
+	USER string;
+
+
+func GetEnv(key string) string {
+	n := len(key);
+	for i := 0; i < sys.envc(); i++ {
+		v := sys.envv(i);
+		if v[0 : n] == key {
+			return v[n + 1 : len(v)];  // +1: trim "="
+		}
+	}
+	return "";
+}
+
+
+func init() {
+	GOARCH = GetEnv("GOARCH");
+	GOOS = GetEnv("GOOS");
+	GOROOT = GetEnv("GOROOT");
+	USER = GetEnv("USER");
+}
+
+
+// ----------------------------------------------------------------------------
+// I/O
+
+export const (
+	MAGIC_obj_file = "@gri-go.7@v0";  // make it clear thar it cannot be a source file
+	src_file_ext = ".go";
+	obj_file_ext = ".7";
+)
+
+
+export func ReadObjectFile(filename string) (data string, ok bool) {
+	data, ok = sys.readfile(filename + obj_file_ext);
+	magic := MAGIC_obj_file;  // TODO remove once len(constant) works
+	if ok && len(data) >= len(magic) && data[0 : len(magic)] == magic {
+		return data, ok;
+	}
+	return "", false;
+}
+
+
+export func ReadSourceFile(filename string) (data string, ok bool) {
+	data, ok = sys.readfile(filename + src_file_ext);
+	return data, ok;
+}

usr/gri/gosrc/printer.go

@@ -186,8 +186,11 @@ func (P *Printer) PrintObject(obj *Globals.Object) {
 
 func (P *Printer) PrintTypeStruct(typ *Globals.Type) {
 	switch typ.form {
-	case Type.UNDEF:
-		print "<undef type>";
+	case Type.VOID:
+		print "void";
+		
+	case Type.FORWARD:
+		print "<forward type>";
 
 	case Type.BAD:
 		print "<bad type>";

usr/gri/gosrc/scanner.go

@@ -4,8 +4,10 @@
 
 package Scanner
 
+import Platform "platform"
 import Utils "utils"
 
+
 export const (
 	ILLEGAL = iota;
 	EOF;
@@ -223,7 +225,7 @@ func init() {
 	}
 	
 	// Provide column information in error messages for gri only...
-	VerboseMsgs = Utils.USER == "gri";
+	VerboseMsgs = Platform.USER == "gri";
 }
 
 
@@ -291,7 +293,7 @@ func (S *Scanner) Next() {
 		Bad	= 0xFFFD;  // Runeerror
 	);
 
-	src := S.src;  // TODO only needed because of 6g bug
+	src := S.src;
 	lim := len(src);
 	pos := S.pos;
 	
@@ -425,38 +427,6 @@ func (S *Scanner) Open(filename, src string) {
 }
 
 
-// TODO this needs to go elsewhere
-func IntString(x, base int) string {
-	neg := false;
-	if x < 0 {
-		x = -x;
-		if x < 0 {
-			panic "smallest int not handled";
-		}
-		neg = true;
-	}
-
-	hex := "0123456789ABCDEF";
-	var buf [16] byte;
-	i := 0;
-	for x > 0 || i == 0 {
-		buf[i] = hex[x % base];
-		x /= base;
-		i++;
-	}
-	
-	s := "";
-	if neg {
-		s = "-";
-	}
-	for i > 0 {
-		i--;
-		s = s + string(int(buf[i]));
-	}
-	return s;
-}
-
-
 func CharString(ch int) string {
 	s := string(ch);
 	switch ch {
@@ -470,7 +440,7 @@ func CharString(ch int) string {
 	case '\\': s = `\\`;
 	case '\'': s = `\'`;
 	}
-	return "'" + s + "' (U+" + IntString(ch, 16) + ")";
+	return "'" + s + "' (U+" + Utils.IntToString(ch, 16) + ")";
 }
 
 

usr/gri/gosrc/type.go

@@ -10,11 +10,28 @@ import Object "object"
 
 export const /* form */ (
 	// internal types
-	UNDEF = iota; VOID; BAD; NIL;
+	// VOID types are used when we don't have a type.
+	VOID = iota;
+	
+	// BAD types are compatible with any type and don't cause further errors.
+	// They are introduced only as a result of an error in the source code. A
+	// correct program cannot have BAD types.
+	BAD;
+	
+	// FORWARD types are forward-declared (incomplete) types. They can only
+	// be used as element types of pointer types and must be resolved before
+	// their internals are accessible.
+	FORWARD;
+	
+	// The type of nil.
+	NIL;
+
 	// basic types
 	BOOL; UINT; INT; FLOAT; STRING; INTEGER;
-	// 'any' type
+	
+	// 'any' type  // TODO this should go away eventually
 	ANY;
+	
 	// composite types
 	ALIAS; ARRAY; STRUCT; INTERFACE; MAP; CHANNEL; FUNCTION; POINTER; REFERENCE;
 )
@@ -33,9 +50,9 @@ export const /* flag */ (
 
 export func FormStr(form int) string {
 	switch form {
-	case UNDEF: return "UNDEF";
 	case VOID: return "VOID";
 	case BAD: return "BAD";
+	case FORWARD: return "FORWARD";
 	case NIL: return "NIL";
 	case BOOL: return "BOOL";
 	case UINT: return "UINT";
@@ -74,7 +91,7 @@ func Equal0(x, y *Globals.Type) bool {
 	}
 
 	switch x.form {
-	case UNDEF, BAD:
+	case FORWARD, BAD:
 		break;
 
 	case NIL, BOOL, STRING, ANY:

usr/gri/gosrc/universe.go

@@ -14,7 +14,7 @@ export var (
 	types *Globals.List;
 	
 	// internal types
-	undef_t,
+	void_t,
 	bad_t,
 	nil_t,
 	
@@ -93,8 +93,8 @@ func init() {
 	types = Globals.NewList();
 	
 	// Interal types
-	undef_t = Globals.NewType(Type.UNDEF);
-	Globals.Universe_undef_t = undef_t;
+	void_t = Globals.NewType(Type.VOID);
+	Globals.Universe_void_t = void_t;
 	bad_t = Globals.NewType(Type.BAD);
 	nil_t = DeclType(Type.NIL, "nil", 8);
 	

usr/gri/gosrc/utils.go

@@ -5,34 +5,6 @@
 package Utils
 
 
-// Environment
-export var
-	GOARCH,
-	GOOS,
-	GOROOT,
-	USER string;
-
-
-func GetEnv(key string) string {
-	n := len(key);
-	for i := 0; i < sys.envc(); i++ {
-		v := sys.envv(i);
-		if v[0 : n] == key {
-			return v[n + 1 : len(v)];  // +1: trim "="
-		}
-	}
-	return "";
-}
-
-
-func init() {
-	GOARCH = GetEnv("GOARCH");
-	GOOS = GetEnv("GOOS");
-	GOROOT = GetEnv("GOROOT");
-	USER = GetEnv("USER");
-}
-
-
 export func BaseName(s string) string {
 	// TODO this is not correct for non-ASCII strings!
 	i := len(s) - 1;
@@ -46,6 +18,12 @@ export func BaseName(s string) string {
 }
 
 
+export func Contains(s, sub string, pos int) bool {
+	end := pos + len(sub);
+	return pos >= 0 && end <= len(s) && s[pos : end] == sub;
+}
+
+
 export func TrimExt(s, ext string) string {
 	i := len(s) - len(ext);
 	if i >= 0 && s[i : len(s)] == ext {
@@ -53,3 +31,33 @@ export func TrimExt(s, ext string) string {
 	}
 	return s;
 }
+
+
+export func IntToString(x, base int) string {
+	x0 := x;
+	if x < 0 {
+		x = -x;
+		if x < 0 {
+			panic "smallest int not handled";
+		}
+	} else if x == 0 {
+		return "0";
+	}
+
+	// x > 0
+	hex := "0123456789ABCDEF";
+	var buf [32] byte;
+	i := len(buf);
+	for x > 0 {
+		i--;
+		buf[i] = hex[x % base];
+		x /= base;
+	}
+	
+	if x0 < 0 {
+		i--;
+		buf[i] = '-';
+	}
+	
+	return string(buf)[i : len(buf)];
+}

usr/gri/gosrc/verifier.go

@@ -45,7 +45,12 @@ func (V *Verifier) VerifyType(typ *Globals.Type) {
 	}
 	
 	switch typ.form {
-	case Type.UNDEF:  // for now - remove eventually
+	case Type.VOID:
+		break;  // TODO for now - remove eventually
+	case Type.FORWARD:
+		if typ.scope == nil {
+			Error("forward types must have a scope");
+		}
 		break;
 	case Type.NIL:
 		break;