2 files changed, 65 insertions, 0 deletions
diff --git a/test/fixedbugs/issue37837.dir/a.go b/test/fixedbugs/issue37837.dir/a.go
new file mode 100644
index 0000000..49d830f
--- /dev/null
+++ b/test/fixedbugs/issue37837.dir/a.go
@@ -0,0 +1,33 @@
+// 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.
+
+package a
+
+func F(i interface{}) int { // ERROR "can inline F" "i does not escape"
+	switch i.(type) {
+	case nil:
+		return 0
+	case int:
+		return 1
+	case float64:
+		return 2
+	default:
+		return 3
+	}
+}
+
+func G(i interface{}) interface{} { // ERROR "can inline G" "leaking param: i"
+	switch i := i.(type) {
+	case nil: // ERROR "moved to heap: i"
+		return &i
+	case int: // ERROR "moved to heap: i"
+		return &i
+	case float64: // ERROR "moved to heap: i"
+		return &i
+	case string, []byte: // ERROR "moved to heap: i"
+		return &i
+	default: // ERROR "moved to heap: i"
+		return &i
+	}
+}
diff --git a/test/fixedbugs/issue37837.dir/b.go b/test/fixedbugs/issue37837.dir/b.go
new file mode 100644
index 0000000..461f5c7
--- /dev/null
+++ b/test/fixedbugs/issue37837.dir/b.go
@@ -0,0 +1,32 @@
+// 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.
+
+package main
+
+import "./a"
+
+func main() {
+	// Test that inlined type switches without short variable
+	// declarations work correctly.
+	check(0, a.F(nil)) // ERROR "inlining call to a.F"
+	check(1, a.F(0))   // ERROR "inlining call to a.F" "does not escape"
+	check(2, a.F(0.0)) // ERROR "inlining call to a.F" "does not escape"
+	check(3, a.F(""))  // ERROR "inlining call to a.F" "does not escape"
+
+	// Test that inlined type switches with short variable
+	// declarations work correctly.
+	_ = a.G(nil).(*interface{})                       // ERROR "inlining call to a.G"
+	_ = a.G(1).(*int)                                 // ERROR "inlining call to a.G" "does not escape"
+	_ = a.G(2.0).(*float64)                           // ERROR "inlining call to a.G" "does not escape"
+	_ = (*a.G("").(*interface{})).(string)            // ERROR "inlining call to a.G" "does not escape"
+	_ = (*a.G(([]byte)(nil)).(*interface{})).([]byte) // ERROR "inlining call to a.G" "does not escape"
+	_ = (*a.G(true).(*interface{})).(bool)            // ERROR "inlining call to a.G" "does not escape"
+}
+
+//go:noinline
+func check(want, got int) {
+	if want != got {
+		println("want", want, "but got", got)
+	}
+}