cmd/nm: do not write to GOROOT testdata directories during TestNM

LGTM=bradfitz
R=bradfitz, 0intro
CC=golang-codereviews
https://golang.org/cl/95280043

diff --git a/src/cmd/nm/nm_test.go b/src/cmd/nm/nm_test.go
index 829c844b491bd5213d282823f662876c86fdeab8..eab0732794f35b1586a0d7b670c2860b2e27813b 100644 (file)
--- a/src/cmd/nm/nm_test.go
+++ b/src/cmd/nm/nm_test.go
@@ -8,6 +8,7 @@ import (
        "bufio"
        "bytes"
        "fmt"
+       "io/ioutil"
        "os"
        "os/exec"
        "path/filepath"
@@ -54,11 +55,17 @@ func checkSymbols(t *testing.T, nmoutput []byte) {
 }
 
 func TestNM(t *testing.T) {
-       out, err := exec.Command("go", "build", "-o", "testnm.exe", "cmd/nm").CombinedOutput()
+       tmpDir, err := ioutil.TempDir("", "TestNM")
        if err != nil {
-               t.Fatalf("go build -o testnm.exe cmd/nm: %v\n%s", err, string(out))
+               t.Fatal("TempDir failed: ", err)
+       }
+       defer os.RemoveAll(tmpDir)
+
+       testnmpath := filepath.Join(tmpDir, "testnm.exe")
+       out, err := exec.Command("go", "build", "-o", testnmpath, "cmd/nm").CombinedOutput()
+       if err != nil {
+               t.Fatalf("go build -o %v cmd/nm: %v\n%s", testnmpath, err, string(out))
        }
-       defer os.Remove("testnm.exe")
 
        testfiles := []string{
                "elf/testdata/gcc-386-freebsd-exec",
@@ -72,14 +79,14 @@ func TestNM(t *testing.T) {
        }
        for _, f := range testfiles {
                exepath := filepath.Join(runtime.GOROOT(), "src", "pkg", "debug", f)
-               cmd := exec.Command("./testnm.exe", exepath)
+               cmd := exec.Command(testnmpath, exepath)
                out, err := cmd.CombinedOutput()
                if err != nil {
                        t.Fatalf("go tool nm %v: %v\n%s", exepath, err, string(out))
                }
        }
 
-       cmd := exec.Command("./testnm.exe", os.Args[0])
+       cmd := exec.Command(testnmpath, os.Args[0])
        out, err = cmd.CombinedOutput()
        if err != nil {
                t.Fatalf("go tool nm %v: %v\n%s", os.Args[0], err, string(out))