blob: 8ac4436947f78cce3b01b2566319d8a6edc01fd2 [file] [log] [blame]
// Copyright 2016 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.
package gc
import (
"internal/testenv"
"io/ioutil"
"os"
"os/exec"
"path/filepath"
"strings"
"testing"
)
type T struct {
x [2]int64 // field that will be clobbered. Also makes type not SSAable.
p *byte // has a pointer
}
//go:noinline
func makeT() T {
return T{}
}
var g T
var sink interface{}
func TestIssue15854(t *testing.T) {
for i := 0; i < 10000; i++ {
if g.x[0] != 0 {
t.Fatalf("g.x[0] clobbered with %x\n", g.x[0])
}
// The bug was in the following assignment. The return
// value of makeT() is not copied out of the args area of
// stack frame in a timely fashion. So when write barriers
// are enabled, the marshaling of the args for the write
// barrier call clobbers the result of makeT() before it is
// read by the write barrier code.
g = makeT()
sink = make([]byte, 1000) // force write barriers to eventually happen
}
}
func TestIssue15854b(t *testing.T) {
const N = 10000
a := make([]T, N)
for i := 0; i < N; i++ {
a = append(a, makeT())
sink = make([]byte, 1000) // force write barriers to eventually happen
}
for i, v := range a {
if v.x[0] != 0 {
t.Fatalf("a[%d].x[0] clobbered with %x\n", i, v.x[0])
}
}
}
// Test that the generated assembly has line numbers (Issue #16214).
func TestIssue16214(t *testing.T) {
testenv.MustHaveGoBuild(t)
dir, err := ioutil.TempDir("", "TestLineNumber")
if err != nil {
t.Fatalf("could not create directory: %v", err)
}
defer os.RemoveAll(dir)
src := filepath.Join(dir, "x.go")
err = ioutil.WriteFile(src, []byte(issue16214src), 0644)
if err != nil {
t.Fatalf("could not write file: %v", err)
}
cmd := exec.Command(testenv.GoToolPath(t), "tool", "compile", "-S", "-o", filepath.Join(dir, "out.o"), src)
out, err := cmd.CombinedOutput()
if err != nil {
t.Fatalf("fail to run go tool compile: %v", err)
}
if strings.Contains(string(out), "unknown line number") {
t.Errorf("line number missing in assembly:\n%s", out)
}
}
var issue16214src = `
package main
func Mod32(x uint32) uint32 {
return x % 3 // frontend rewrites it as HMUL with 2863311531, the LITERAL node has unknown Pos
}
`