mirror of
https://github.com/golang/go
synced 2024-11-22 10:54:46 -07:00
b2fd76ab8d
Most of the test cases in the test directory use the new go:build syntax already. Convert the rest. In general, try to place the build constraint line below the test directive comment in more places. For #41184. For #60268. Change-Id: I11c41a0642a8a26dc2eda1406da908645bbc005b Cq-Include-Trybots: luci.golang.try:gotip-linux-386-longtest,gotip-linux-amd64-longtest,gotip-windows-amd64-longtest Reviewed-on: https://go-review.googlesource.com/c/go/+/536236 Reviewed-by: Ian Lance Taylor <iant@google.com> Reviewed-by: Dmitri Shuralyov <dmitshur@google.com> Auto-Submit: Dmitri Shuralyov <dmitshur@golang.org> LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
72 lines
1.9 KiB
Go
72 lines
1.9 KiB
Go
// run
|
|
|
|
//go:build linux || darwin
|
|
|
|
// Copyright 2020 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.
|
|
|
|
// This is an optimization check. We want to make sure that we compare
|
|
// string lengths, and other scalar fields, before checking string
|
|
// contents. There's no way to verify this in the language, and
|
|
// codegen tests in test/codegen can't really detect ordering
|
|
// optimizations like this. Instead, we generate invalid strings with
|
|
// bad backing store pointers but nonzero length, so we can check that
|
|
// the backing store never gets compared.
|
|
//
|
|
// We use two different bad strings so that pointer comparisons of
|
|
// backing store pointers fail.
|
|
|
|
package main
|
|
|
|
import (
|
|
"fmt"
|
|
"reflect"
|
|
"syscall"
|
|
"unsafe"
|
|
)
|
|
|
|
type SI struct {
|
|
s string
|
|
i int
|
|
}
|
|
|
|
type SS struct {
|
|
s string
|
|
t string
|
|
}
|
|
|
|
func main() {
|
|
bad1 := "foo"
|
|
bad2 := "foo"
|
|
|
|
p := syscall.Getpagesize()
|
|
b, err := syscall.Mmap(-1, 0, p, syscall.PROT_READ|syscall.PROT_WRITE, syscall.MAP_ANON|syscall.MAP_PRIVATE)
|
|
if err != nil {
|
|
panic(err)
|
|
}
|
|
err = syscall.Mprotect(b, syscall.PROT_NONE)
|
|
if err != nil {
|
|
panic(err)
|
|
}
|
|
// write inaccessible pointers as the data fields of bad1 and bad2.
|
|
(*reflect.StringHeader)(unsafe.Pointer(&bad1)).Data = uintptr(unsafe.Pointer(&b[0]))
|
|
(*reflect.StringHeader)(unsafe.Pointer(&bad2)).Data = uintptr(unsafe.Pointer(&b[1]))
|
|
|
|
for _, test := range []struct {
|
|
a, b interface{}
|
|
}{
|
|
{SI{s: bad1, i: 1}, SI{s: bad2, i: 2}},
|
|
{SS{s: bad1, t: "a"}, SS{s: bad2, t: "aa"}},
|
|
{SS{s: "a", t: bad1}, SS{s: "b", t: bad2}},
|
|
// This one would panic because the length of both strings match, and we check
|
|
// the body of the bad strings before the body of the good strings.
|
|
//{SS{s: bad1, t: "a"}, SS{s: bad2, t: "b"}},
|
|
} {
|
|
if test.a == test.b {
|
|
panic(fmt.Sprintf("values %#v and %#v should not be equal", test.a, test.b))
|
|
}
|
|
}
|
|
|
|
}
|