go/test/fixedbugs/issue27278.go
Cherry Zhang 54f9c0416a cmd/compile: count nil check as use in dead auto elim
Nil check is special in that it has no use but we must keep it.
Count it as a use of the auto.

Fixes #27278.

Change-Id: I857c3d0db2ebdca1bc342b4993c0dac5c01e067f
Reviewed-on: https://go-review.googlesource.com/131955
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2018-08-30 02:19:37 +00:00

64 lines
865 B
Go

// run
// Copyright 2018 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.
// Issue 27278: dead auto elim deletes an auto and its
// initialization, but it is live because of a nil check.
package main
type T struct {
_ [3]string
T2
}
func (t *T) M() []string {
return t.T2.M()
}
type T2 struct {
T3
}
func (t *T2) M() []string {
return t.T3.M()
}
type T3 struct {
a string
}
func (t *T3) M() []string {
return []string{}
}
func main() {
poison()
f()
}
//go:noinline
func f() {
(&T{}).M()
grow(10000)
}
// grow stack, triggers stack copy
func grow(n int) {
if n == 0 {
return
}
grow(n-1)
}
// put some junk on stack, which cannot be valid address
//go:noinline
func poison() {
x := [10]int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}
g = x
}
var g [10]int