golang issue26407 代码
文件路径：/test/fixedbugs/issue26407.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 26407: ensure that stack variables which have
/ had their address taken and then used in a comparison,
/ but are otherwise unused, are cleared.
package main
func main() {
poison()
test()
}
/go:noinline
func poison() {
/ initialise the stack with invalid pointers
var large [256]uintptr
for i := range large {
large[i] = 1
}
use(large[:])
}
/go:noinline
func test() {
a := 2
x := &a
if x != compare(&x) {
panic("not possible")
}
}
/go:noinline
func compare(x **int) *int {
var y *int
if x == &y {
panic("not possible")
}
/ grow the stack to trigger a check for invalid pointers
grow()
if x == &y {
panic("not possible")
}
return *x
}
/go:noinline
func grow() {
var large [1 << 16]uintptr
use(large[:])
}
/go:noinline
func use(_ []uintptr) { }