mirror of
https://github.com/golang/go.git
synced 2025-05-05 15:43:04 +00:00
[release-branch.go1.17] 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). Updates #52953. Fixes #52960. 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> (cherry picked from commit 1c77137d4fdfbb3e7e8d9efaab3bab5ee736a19d) Reviewed-on: https://go-review.googlesource.com/c/go/+/419451 Reviewed-by: Matthew Dempsky <mdempsky@google.com>
This commit is contained in:
parent
489c148578
commit
d9242f7a8c
@ -621,6 +621,12 @@ func oaslit(n *ir.AssignStmt, init *ir.Nodes) bool {
|
||||
// not a special composite literal assignment
|
||||
return false
|
||||
}
|
||||
if x.Addrtaken() {
|
||||
// If x is address-taken, the RHS may (implicitly) uses LHS.
|
||||
// Not safe to do a special composite literal assignment
|
||||
// (which may expand to multiple assignments).
|
||||
return false
|
||||
}
|
||||
|
||||
switch n.Y.Op() {
|
||||
default:
|
||||
@ -629,7 +635,7 @@ func oaslit(n *ir.AssignStmt, init *ir.Nodes) bool {
|
||||
|
||||
case ir.OSTRUCTLIT, ir.OARRAYLIT, ir.OSLICELIT, ir.OMAPLIT:
|
||||
if ir.Any(n.Y, func(y ir.Node) bool { return ir.Uses(y, x) }) {
|
||||
// not a special composite literal assignment
|
||||
// not safe to do a special composite literal assignment if RHS uses LHS.
|
||||
return false
|
||||
}
|
||||
anylit(n.Y, n.X, init)
|
||||
|
29
test/fixedbugs/issue52953.go
Normal file
29
test/fixedbugs/issue52953.go
Normal file
@ -0,0 +1,29 @@
|
||||
// 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")
|
||||
}
|
||||
}
|
Loading…
x
Reference in New Issue
Block a user