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54f9c0416a
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>
64 lines
865 B
Go
64 lines
865 B
Go
// run
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// Copyright 2018 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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// Issue 27278: dead auto elim deletes an auto and its
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// initialization, but it is live because of a nil check.
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package main
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type T struct {
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_ [3]string
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T2
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}
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func (t *T) M() []string {
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return t.T2.M()
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}
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type T2 struct {
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T3
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}
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func (t *T2) M() []string {
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return t.T3.M()
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}
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type T3 struct {
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a string
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}
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func (t *T3) M() []string {
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return []string{}
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}
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func main() {
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poison()
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f()
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}
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//go:noinline
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func f() {
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(&T{}).M()
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grow(10000)
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}
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// grow stack, triggers stack copy
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func grow(n int) {
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if n == 0 {
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return
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}
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grow(n-1)
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}
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// put some junk on stack, which cannot be valid address
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//go:noinline
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func poison() {
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x := [10]int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}
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g = x
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}
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var g [10]int
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