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// 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.
// This test makes sure that naming named
// return variables in a return statement works.
// See issue #14904.
package main
import (
"runtime"
"testing"
)
// Our heap-allocated object that will be GC'd incorrectly.
// Note that we always check the second word because that's
// where 0xdeaddeaddeaddead is written.
type B [4]int
// small (SSAable) array
type A1 [3]*B
//go:noinline
func f1() (t A1) {
t[0] = &B{91, 92, 93, 94}
runtime.GC()
return t
}
// large (non-SSAable) array
type A2 [8]*B
//go:noinline
func f2() (t A2) {
t[0] = &B{91, 92, 93, 94}
runtime.GC()
return t
}
// small (SSAable) struct
type A3 struct {
a, b, c *B
}
//go:noinline
func f3() (t A3) {
t.a = &B{91, 92, 93, 94}
runtime.GC()
return t
}
// large (non-SSAable) struct
type A4 struct {
a, b, c, d, e, f *B
}
//go:noinline
func f4() (t A4) {
t.a = &B{91, 92, 93, 94}
runtime.GC()
return t
}
var sink *B
func f5() int {
b := &B{91, 92, 93, 94}
t := A4{b, nil, nil, nil, nil, nil}
sink = b // make sure b is heap allocated ...
sink = nil // ... but not live
runtime.GC()
t = t
return t.a[1]
}
func TestNamedReturn(t *testing.T) {
if v := f1()[0][1]; v != 92 {
t.Errorf("f1()[0][1]=%d, want 92\n", v)
}
if v := f2()[0][1]; v != 92 {
t.Errorf("f2()[0][1]=%d, want 92\n", v)
}
if v := f3().a[1]; v != 92 {
t.Errorf("f3().a[1]=%d, want 92\n", v)
}
if v := f4().a[1]; v != 92 {
t.Errorf("f4().a[1]=%d, want 92\n", v)
}
if v := f5(); v != 92 {
t.Errorf("f5()=%d, want 92\n", v)
}
}