From 53c66543e022b1a96a599fee0819f6b16e92bead Mon Sep 17 00:00:00 2001
From: Russ Cox <rsc@golang.org>
Date: Thu, 25 Sep 2014 13:08:37 -0400
Subject: [PATCH] cmd/gc: avoid infinite recursion on invalid recursive type
Fixes #8507.
LGTM=iant
R=golang-codereviews, iant
CC=golang-codereviews, r
https://golang.org/cl/144560043
---
src/cmd/gc/align.c | 4 +++-
src/cmd/gc/subr.c | 3 ++-
test/fixedbugs/issue8507.go | 16 ++++++++++++++++
3 files changed, 21 insertions(+), 2 deletions(-)
create mode 100644 test/fixedbugs/issue8507.go
diff --git a/src/cmd/gc/align.c b/src/cmd/gc/align.c
index b809640e42..6e5d149c75 100644
--- a/src/cmd/gc/align.c
+++ b/src/cmd/gc/align.c
@@ -119,8 +119,10 @@ dowidth(Type *t)
if(t->width == -2) {
lno = lineno;
lineno = t->lineno;
- if(!t->broke)
+ if(!t->broke) {
+ t->broke = 1;
yyerror("invalid recursive type %T", t);
+ }
t->width = 0;
lineno = lno;
return;
diff --git a/src/cmd/gc/subr.c b/src/cmd/gc/subr.c
index 666be96679..c3bc5af3b8 100644
--- a/src/cmd/gc/subr.c
+++ b/src/cmd/gc/subr.c
@@ -529,7 +529,8 @@ algtype1(Type *t, Type **bad)
if(bad)
*bad = T;
-
+ if(t->broke)
+ return AMEM;
if(t->noalg)
return ANOEQ;
diff --git a/test/fixedbugs/issue8507.go b/test/fixedbugs/issue8507.go
new file mode 100644
index 0000000000..00a14aa88f
--- /dev/null
+++ b/test/fixedbugs/issue8507.go
@@ -0,0 +1,16 @@
+// errorcheck
+
+// Copyright 2014 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.
+
+// issue 8507
+// used to call algtype on invalid recursive type and get into infinite recursion
+
+package p
+
+type T struct{ T } // ERROR "invalid recursive type T"
+
+func f() {
+ println(T{} == T{})
+}
--
2.30.9