From 05a1eb1ab0650b465b23f01ca0ea5944735fa63b Mon Sep 17 00:00:00 2001
From: Russ Cox <rsc@golang.org>
Date: Thu, 3 Dec 2009 01:12:02 -0800
Subject: [PATCH] gc: recursive type error

Fixes #245.

R=ken2
https://golang.org/cl/164094
---
 src/cmd/gc/align.c       |  3 +++
 src/cmd/gc/typecheck.c   |  2 ++
 test/fixedbugs/bug224.go | 10 ++++++++++
 3 files changed, 15 insertions(+)
 create mode 100644 test/fixedbugs/bug224.go

diff --git a/src/cmd/gc/align.c b/src/cmd/gc/align.c
index b74ac0f29f..cf08516465 100644
--- a/src/cmd/gc/align.c
+++ b/src/cmd/gc/align.c
@@ -205,6 +205,9 @@ dowidth(Type *t)
 		checkwidth(t->down);
 		break;
 	case TFORW:		// should have been filled in
+		yyerror("invalid recursive type %T", t);
+		w = 1;	// anything will do
+		break;
 	case TANY:
 		// dummy type; should be replaced before use.
 		if(!debug['A'])
diff --git a/src/cmd/gc/typecheck.c b/src/cmd/gc/typecheck.c
index 0fd359b319..76147e48f0 100644
--- a/src/cmd/gc/typecheck.c
+++ b/src/cmd/gc/typecheck.c
@@ -1039,6 +1039,8 @@ reswitch:
 	case ODCLTYPE:
 		ok |= Etop;
 		typecheck(&n->left, Etype);
+		if(!incannedimport)
+			checkwidth(n->left->type);
 		goto ret;
 	}
 
diff --git a/test/fixedbugs/bug224.go b/test/fixedbugs/bug224.go
new file mode 100644
index 0000000000..11ee57ecfa
--- /dev/null
+++ b/test/fixedbugs/bug224.go
@@ -0,0 +1,10 @@
+// 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 T		// ERROR "recursive"
+
-- 
2.50.0