2 files changed, 45 insertions, 0 deletions
diff --git a/src/cmd/link/internal/ld/testdata/deadcode/ifacemethod.go b/src/cmd/link/internal/ld/testdata/deadcode/ifacemethod.go
new file mode 100644
index 0000000000..b62f18c342
--- /dev/null
+++ b/src/cmd/link/internal/ld/testdata/deadcode/ifacemethod.go
@@ -0,0 +1,23 @@
+// Copyright 2020 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 that a method of a reachable type is not necessarily
+// live even if it matches an interface method, as long as
+// the type is never converted to an interface.
+
+package main
+
+type I interface{ M() }
+
+type T int
+
+func (T) M() { println("XXX") }
+
+var p *T
+var e interface{}
+
+func main() {
+	p = new(T) // used T, but never converted to interface
+	e.(I).M()  // used I and I.M
+}
diff --git a/src/cmd/link/internal/ld/testdata/deadcode/ifacemethod2.go b/src/cmd/link/internal/ld/testdata/deadcode/ifacemethod2.go
new file mode 100644
index 0000000000..48ba55d35e
--- /dev/null
+++ b/src/cmd/link/internal/ld/testdata/deadcode/ifacemethod2.go
@@ -0,0 +1,22 @@
+// Copyright 2020 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 that a method *is* live if it matches an interface
+// method and the type is "indirectly" converted to an
+// interface through reflection.
+
+package main
+
+import "reflect"
+
+type I interface{ M() }
+
+type T int
+
+func (T) M() { println("XXX") }
+
+func main() {
+	e := reflect.ValueOf([]T{1}).Index(0).Interface()
+	e.(I).M()
+}