cmd/gc: check for initialization cycles in method values

Fixes issue 7960.

LGTM=rsc
R=rsc
CC=golang-codereviews, gri
https://codereview.appspot.com/159800045

1 files changed, 28 insertions, 0 deletions

diff --git a/test/fixedbugs/issue6703r.go b/test/fixedbugs/issue6703r.go
new file mode 100644
index 000000000..669846241
--- /dev/null
+++ b/test/fixedbugs/issue6703r.go
@@ -0,0 +1,28 @@
+// 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.
+
+// Check for cycles in the method call of an embedded struct returned
+// from a function call.
+
+package funcembedmethcall
+
+type T int
+
+func (T) m() int {
+	_ = x
+	return 0
+}
+
+func g() E {
+	return E{0}
+}
+
+type E struct{ T }
+
+var (
+	e E
+	x = g().m() // ERROR "initialization loop|depends upon itself" 
+)