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https://github.com/golang/go
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744ebfde04
This is a crude compiler pass to eliminate stores to auto variables
that are only ever written to.
Eliminates an unnecessary store to x from the following code:
func f() int {
var x := 1
return *(&x)
}
Fixes #19765.
Change-Id: If2c63a8ae67b8c590b6e0cc98a9610939a3eeffa
Reviewed-on: https://go-review.googlesource.com/38746
Run-TryBot: Michael Munday <mike.munday@ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
43 lines
1.1 KiB
Go
43 lines
1.1 KiB
Go
// errorcheck -0 -live -wb=0
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// Copyright 2014 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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// liveness tests with inlining ENABLED
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// see also live.go.
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package main
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// issue 8142: lost 'addrtaken' bit on inlined variables.
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// no inlining in this test, so just checking that non-inlined works.
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func printnl()
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//go:noescape
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func useT40(*T40)
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type T40 struct {
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m map[int]int
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}
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func newT40() *T40 {
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ret := T40{}
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ret.m = make(map[int]int) // ERROR "live at call to makemap: &ret$"
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return &ret
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}
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func bad40() {
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t := newT40() // ERROR "live at call to makemap: .autotmp_[0-9]+ ret$"
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printnl() // ERROR "live at call to printnl: .autotmp_[0-9]+ ret$"
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useT40(t) // ERROR "live at call to useT40: .autotmp_[0-9]+ ret$"
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}
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func good40() {
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ret := T40{}
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ret.m = make(map[int]int) // ERROR "live at call to makemap: .autotmp_[0-9]+ ret$"
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t := &ret
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printnl() // ERROR "live at call to printnl: .autotmp_[0-9]+ ret$"
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useT40(t) // ERROR "live at call to useT40: .autotmp_[0-9]+ ret$"
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}
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