1 files changed, 94 insertions, 0 deletions
diff --git a/test/nowritebarrier.go b/test/nowritebarrier.go
new file mode 100644
index 0000000..654f16d
--- /dev/null
+++ b/test/nowritebarrier.go
@@ -0,0 +1,94 @@
+// errorcheck -+
+
+// Copyright 2016 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.
+
+// Test go:nowritebarrier and related directives.
+
+package p
+
+type t struct {
+	f *t
+}
+
+var x t
+var y *t
+
+//go:nowritebarrier
+func a1() {
+	x.f = y // ERROR "write barrier prohibited"
+	a2()    // no error
+}
+
+//go:noinline
+func a2() {
+	x.f = y
+}
+
+//go:nowritebarrierrec
+func b1() {
+	b2()
+}
+
+//go:noinline
+func b2() {
+	x.f = y // ERROR "write barrier prohibited by caller"
+}
+
+// Test recursive cycles through nowritebarrierrec and yeswritebarrierrec.
+
+//go:nowritebarrierrec
+func c1() {
+	c2()
+}
+
+//go:yeswritebarrierrec
+func c2() {
+	c3()
+}
+
+func c3() {
+	x.f = y
+	c4()
+}
+
+//go:nowritebarrierrec
+func c4() {
+	c2()
+}
+
+//go:nowritebarrierrec
+func d1() {
+	d2()
+}
+
+func d2() {
+	d3()
+}
+
+//go:noinline
+func d3() {
+	x.f = y // ERROR "write barrier prohibited by caller"
+	d4()
+}
+
+//go:yeswritebarrierrec
+func d4() {
+	d2()
+}
+
+//go:noinline
+func systemstack(func()) {}
+
+//go:nowritebarrierrec
+func e1() {
+	systemstack(e2)
+	systemstack(func() {
+		x.f = y // ERROR "write barrier prohibited by caller"
+	})
+}
+
+func e2() {
+	x.f = y // ERROR "write barrier prohibited by caller"
+}