add & fix bug208, from ken.

fix bug198.

R=ken
OCL=35504
CL=35507

src/cmd/gc/dcl.c

@@ -781,6 +781,10 @@ stotype(NodeList *l, int et, Type **t)
 		if(n->right != N) {
 			typecheck(&n->right, Etype);
 			n->type = n->right->type;
+			if(n->type == T) {
+				*t0 = T;
+				return t0;
+			}
 			if(n->left != N)
 				n->left->type = n->type;
 			n->right = N;
@@ -886,6 +890,10 @@ dostruct(NodeList *l, int et)
 	t = typ(et);
 	t->funarg = funarg;
 	stotype(l, et, &t->type);
+	if(t->type == T && l != nil) {
+		t->broke = 1;
+		return t;
+	}
 	if(!funarg)
 		checkwidth(t);
 	return t;

src/cmd/gc/go.h

@@ -145,6 +145,7 @@ struct	Type
 	uchar	copyany;
 	uchar	local;		// created in this file
 	uchar	deferwidth;
+	uchar	broke;
 
 	Node*	nod;		// canonical OTYPE node
 	int		lineno;

src/cmd/gc/typecheck.c

@@ -81,10 +81,12 @@ typecheck(Node **np, int top)
 	n->typecheck = 2;
 
 redo:
-	if(n->sym)
-		walkdef(n);
-
 	lno = setlineno(n);
+	if(n->sym) {
+		walkdef(n);
+		if(n->op == ONONAME)
+			goto error;
+	}
 
 reswitch:
 	ok = 0;
@@ -683,6 +685,8 @@ reswitch:
 		ok |= Erv;
 		if(t->outtuple == 1) {
 			t = getoutargx(l->type)->type;
+			if(t == T)
+				goto error;
 			if(t->etype == TFIELD)
 				t = t->type;
 			n->type = t;
@@ -1384,6 +1388,9 @@ typecheckaste(int op, Type *tstruct, NodeList *nl)
 
 	lno = lineno;
 
+	if(tstruct->broke)
+		goto out;
+
 	if(nl != nil && nl->next == nil && (n = nl->n)->type != T)
 	if(n->type->etype == TSTRUCT && n->type->funarg) {
 		setlineno(n);
@@ -1592,7 +1599,6 @@ typecheckcomplit(Node **np)
 
 	memset(hash, 0, sizeof hash);
 
-	// TODO: dup detection
 	l = typecheck(&n->right /* sic */, Etype /* TODO | Edotarray */);
 	if((t = l->type) == T)
 		goto error;
@@ -1699,6 +1705,7 @@ typecheckcomplit(Node **np)
 					typecheck(&l->right, Erv);
 					continue;
 				}
+				l->left = newname(l->left->sym);
 				l->left->typecheck = 1;
 				f = lookdot1(l->left->sym, t, t->type);
 				typecheck(&l->right, Erv);

test/fixedbugs/bug198.go

@@ -5,7 +5,8 @@
 // license that can be found in the LICENSE file.
 
 package main
-func f(a T) T {	return a }	// ERROR "T"
+func f(a T) T { return a }	// ERROR "undefined"
 func main() {
 	x := f(0);
+	_ = x;
 }

test/fixedbugs/bug208.go

@@ -0,0 +1,20 @@
+// errchk $G $D/$F.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 main
+
+type	T struct
+{
+	f int;
+}
+
+var _ = T{f: 1}
+
+// 6g used to get confused by the f:1 above
+// and allow uses of f that would be silently
+// dropped during the compilation.
+var _ = f;	// ERROR "undefined"
+

test/golden.out

@@ -167,10 +167,3 @@ BUG: errchk: bugs/bug193.go:14: missing expected error: 'shift'
 too many calls: 5
 panic PC=xxx
 BUG: bug196
-
-=========== bugs/bug198.go
-bugs/bug198.go:8: undefined: T
-bugs/bug198.go:8: T is not a type
-bugs/bug198.go:8: too many arguments to return
-bugs/bug198.go:10: too many arguments to CALL
-BUG: errchk: compiler crashed