go/test/fixedbugs/issue24503.go
Bryan Chan 625f2dccd4 cmd/compile/internal/ssa: handle symbol address comparisons consistently
CL 38338 introduced SSA rules to optimize two types of pointer equality
tests: a pointer compared with itself, and comparison of addresses taken
of two symbols which may have the same base. This patch adds rules to
apply the same optimization to pointer inequality tests, which also ensures
that two pointers to zero-width types cannot be both equal and unequal
at the same time.

Fixes #24503.

Change-Id: Ic828aeb86ae2e680caf66c35f4c247674768a9ba
Reviewed-on: https://go-review.googlesource.com/102275
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2018-03-31 21:37:13 +00:00

28 lines
517 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 24503: Handle == and != of addresses taken of symbols consistently.
package main
func test() string {
type test struct{}
o1 := test{}
o2 := test{}
if &o1 == &o2 {
return "equal"
}
if &o1 != &o2 {
return "unequal"
}
return "failed"
}
func main() {
if test() == "failed" {
panic("expected either 'equal' or 'unequal'")
}
}