go/test/fixedbugs/issue52953.go
Cherry Mui 1c77137d4f cmd/compile: do not use special literal assignment if LHS is address-taken
A composite literal assignment

x = T{field: v}

may be compiled to

x = T{}
x.field = v

We already do not use this form is RHS uses LHS. If LHS is
address-taken, RHS may uses LHS implicitly, e.g.

v = &x.field
x = T{field: *v}

The lowering above would change the value of RHS (*v).

Fixes #52953.

Change-Id: I3f798e00598aaa550b8c17182c7472fef440d483
Reviewed-on: https://go-review.googlesource.com/c/go/+/407014
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Run-TryBot: Cherry Mui <cherryyz@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
2022-05-18 18:24:59 +00:00

30 lines
488 B
Go

// run
// Copyright 2022 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 52953: miscompilation for composite literal assignment
// when LHS is address-taken.
package main
type T struct {
Field1 bool
}
func main() {
var ret T
ret.Field1 = true
var v *bool = &ret.Field1
ret = T{Field1: *v}
check(ret.Field1)
}
//go:noinline
func check(b bool) {
if !b {
panic("FAIL")
}
}