cmd/go: remove work directory on usage error

    
    Backport https://golang.org/cl/163237 from the master library:
    
        Ensure that cmd/go consistently calls base.Exit rather than os.Exit,
        so that we don't incorrectly leave the work directory around on exit.
    
        Test this by modifying the testsuite to run all the tests with TMPDIR
        set to a temporary directory, and then check that no files are left
        behind in that temporary directory. Adjust a couple of tests to make
        this approach work.
    
    Updates https://gcc.gnu.org/PR89406
    
    Reviewed-on: https://go-review.googlesource.com/c/163198

From-SVN: r269086

10 files changed, 71 insertions, 19 deletions

diff --git a/libgo/go/cmd/go/go_test.go b/libgo/go/cmd/go/go_test.go
index 63549cf..10ff53f 100644
--- a/libgo/go/cmd/go/go_test.go
+++ b/libgo/go/cmd/go/go_test.go
@@ -146,7 +146,18 @@ func TestMain(m *testing.M) {
 		select {}
 	}
 
-	dir, err := ioutil.TempDir(os.Getenv("GOTMPDIR"), "cmd-go-test-")
+	// Run with a temporary TMPDIR to check that the tests don't
+	// leave anything behind.
+	topTmpdir, err := ioutil.TempDir("", "cmd-go-test-")
+	if err != nil {
+		log.Fatal(err)
+	}
+	if !*testWork {
+		defer removeAll(topTmpdir)
+	}
+	os.Setenv(tempEnvName(), topTmpdir)
+
+	dir, err := ioutil.TempDir(topTmpdir, "tmpdir")
 	if err != nil {
 		log.Fatal(err)
 	}
@@ -258,6 +269,23 @@ func TestMain(m *testing.M) {
 		removeAll(testTmpDir) // os.Exit won't run defer
 	}
 
+	if !*testWork {
+		// There shouldn't be anything left in topTmpdir.
+		dirf, err := os.Open(topTmpdir)
+		if err != nil {
+			log.Fatal(err)
+		}
+		names, err := dirf.Readdirnames(0)
+		if err != nil {
+			log.Fatal(err)
+		}
+		if len(names) > 0 {
+			log.Fatalf("unexpected files left in tmpdir: %v", names)
+		}
+
+		removeAll(topTmpdir)
+	}
+
 	os.Exit(r)
 }
 
@@ -5020,7 +5048,8 @@ func TestExecBuildX(t *testing.T) {
 	obj := tg.path("main")
 	tg.run("build", "-x", "-o", obj, src)
 	sh := tg.path("test.sh")
-	err := ioutil.WriteFile(sh, []byte("set -e\n"+tg.getStderr()), 0666)
+	cmds := tg.getStderr()
+	err := ioutil.WriteFile(sh, []byte("set -e\n"+cmds), 0666)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -5051,6 +5080,12 @@ func TestExecBuildX(t *testing.T) {
 	if string(out) != "hello" {
 		t.Fatalf("got %q; want %q", out, "hello")
 	}
+
+	matches := regexp.MustCompile(`^WORK=(.*)\n`).FindStringSubmatch(cmds)
+	if len(matches) == 0 {
+		t.Fatal("no WORK directory")
+	}
+	tg.must(os.RemoveAll(matches[1]))
 }
 
 func TestParallelNumber(t *testing.T) {
diff --git a/libgo/go/cmd/go/internal/base/base.go b/libgo/go/cmd/go/internal/base/base.go
index e7f54c9..bf810ff 100644
--- a/libgo/go/cmd/go/internal/base/base.go
+++ b/libgo/go/cmd/go/internal/base/base.go
@@ -82,7 +82,8 @@ func (c *Command) Name() string {
 func (c *Command) Usage() {
 	fmt.Fprintf(os.Stderr, "usage: %s\n", c.UsageLine)
 	fmt.Fprintf(os.Stderr, "Run 'go help %s' for details.\n", c.LongName())
-	os.Exit(2)
+	SetExitStatus(2)
+	Exit()
 }
 
 // Runnable reports whether the command can be run; otherwise
diff --git a/libgo/go/cmd/go/internal/cmdflag/flag.go b/libgo/go/cmd/go/internal/cmdflag/flag.go
index 7f2c53de..3f93432 100644
--- a/libgo/go/cmd/go/internal/cmdflag/flag.go
+++ b/libgo/go/cmd/go/internal/cmdflag/flag.go
@@ -66,7 +66,8 @@ func SyntaxError(cmd, msg string) {
 	} else {
 		fmt.Fprintf(os.Stderr, `run "go help %s" for more information`+"\n", cmd)
 	}
-	os.Exit(2)
+	base.SetExitStatus(2)
+	base.Exit()
 }
 
 // AddKnownFlags registers the flags in defns with base.AddKnownFlag.
diff --git a/libgo/go/cmd/go/internal/help/help.go b/libgo/go/cmd/go/internal/help/help.go
index 312a295..121deb7 100644
--- a/libgo/go/cmd/go/internal/help/help.go
+++ b/libgo/go/cmd/go/internal/help/help.go
@@ -63,7 +63,8 @@ Args:
 			helpSuccess = " " + strings.Join(args[:i], " ")
 		}
 		fmt.Fprintf(os.Stderr, "go help %s: unknown help topic. Run '%s'.\n", strings.Join(args, " "), helpSuccess)
-		os.Exit(2) // failed at 'go help cmd'
+		base.SetExitStatus(2) // failed at 'go help cmd'
+		base.Exit()
 	}
 
 	if len(cmd.Commands) > 0 {
@@ -167,7 +168,8 @@ func tmpl(w io.Writer, text string, data interface{}) {
 	if ew.err != nil {
 		// I/O error writing. Ignore write on closed pipe.
 		if strings.Contains(ew.err.Error(), "pipe") {
-			os.Exit(1)
+			base.SetExitStatus(1)
+			base.Exit()
 		}
 		base.Fatalf("writing output: %v", ew.err)
 	}
diff --git a/libgo/go/cmd/go/internal/vet/vetflag.go b/libgo/go/cmd/go/internal/vet/vetflag.go
index 37342f4..cbe7f8c 100644
--- a/libgo/go/cmd/go/internal/vet/vetflag.go
+++ b/libgo/go/cmd/go/internal/vet/vetflag.go
@@ -76,7 +76,8 @@ func vetFlags(usage func(), args []string) (passToVet, packageNames []string) {
 	vetcmd.Stdout = out
 	if err := vetcmd.Run(); err != nil {
 		fmt.Fprintf(os.Stderr, "go vet: can't execute %s -flags: %v\n", tool, err)
-		os.Exit(2)
+		base.SetExitStatus(2)
+		base.Exit()
 	}
 	var analysisFlags []struct {
 		Name  string
@@ -85,7 +86,8 @@ func vetFlags(usage func(), args []string) (passToVet, packageNames []string) {
 	}
 	if err := json.Unmarshal(out.Bytes(), &analysisFlags); err != nil {
 		fmt.Fprintf(os.Stderr, "go vet: can't unmarshal JSON from %s -flags: %v", tool, err)
-		os.Exit(2)
+		base.SetExitStatus(2)
+		base.Exit()
 	}
 
 	// Add vet's flags to vetflagDefn.
@@ -134,7 +136,8 @@ func vetFlags(usage func(), args []string) (passToVet, packageNames []string) {
 		if f == nil {
 			fmt.Fprintf(os.Stderr, "vet: flag %q not defined\n", args[i])
 			fmt.Fprintf(os.Stderr, "Run \"go help vet\" for more information\n")
-			os.Exit(2)
+			base.SetExitStatus(2)
+			base.Exit()
 		}
 		if f.Value != nil {
 			if err := f.Value.Set(value); err != nil {
@@ -182,5 +185,6 @@ func usage() {
 	}
 	fmt.Fprintf(os.Stderr, "Run '%s -help' for the vet tool's flags.\n", cmd)
 
-	os.Exit(2)
+	base.SetExitStatus(2)
+	base.Exit()
 }
diff --git a/libgo/go/cmd/go/internal/work/action.go b/libgo/go/cmd/go/internal/work/action.go
index d0d0211..1cc701d 100644
--- a/libgo/go/cmd/go/internal/work/action.go
+++ b/libgo/go/cmd/go/internal/work/action.go
@@ -249,12 +249,14 @@ func (b *Builder) Init() {
 
 	if _, ok := cfg.OSArchSupportsCgo[cfg.Goos+"/"+cfg.Goarch]; !ok && cfg.BuildContext.Compiler == "gc" {
 		fmt.Fprintf(os.Stderr, "cmd/go: unsupported GOOS/GOARCH pair %s/%s\n", cfg.Goos, cfg.Goarch)
-		os.Exit(2)
+		base.SetExitStatus(2)
+		base.Exit()
 	}
 	for _, tag := range cfg.BuildContext.BuildTags {
 		if strings.Contains(tag, ",") {
 			fmt.Fprintf(os.Stderr, "cmd/go: -tags space-separated list contains comma\n")
-			os.Exit(2)
+			base.SetExitStatus(2)
+			base.Exit()
 		}
 	}
 }
diff --git a/libgo/go/cmd/go/internal/work/exec.go b/libgo/go/cmd/go/internal/work/exec.go
index a4feb1d..de18dae 100644
--- a/libgo/go/cmd/go/internal/work/exec.go
+++ b/libgo/go/cmd/go/internal/work/exec.go
@@ -2334,7 +2334,7 @@ func (b *Builder) gccSupportsFlag(compiler []string, flag string) bool {
 	// version of GCC, so some systems have frozen on it.
 	// Now we pass an empty file on stdin, which should work at least for
 	// GCC and clang.
-	cmdArgs := str.StringList(compiler, flag, "-c", "-x", "c", "-")
+	cmdArgs := str.StringList(compiler, flag, "-c", "-x", "c", "-", "-o", os.DevNull)
 	if cfg.BuildN || cfg.BuildX {
 		b.Showcmd(b.WorkDir, "%s || true", joinUnambiguously(cmdArgs))
 		if cfg.BuildN {
diff --git a/libgo/go/cmd/go/internal/work/gccgo.go b/libgo/go/cmd/go/internal/work/gccgo.go
index 82da591..6311d65 100644
--- a/libgo/go/cmd/go/internal/work/gccgo.go
+++ b/libgo/go/cmd/go/internal/work/gccgo.go
@@ -56,7 +56,8 @@ func checkGccgoBin() {
 		return
 	}
 	fmt.Fprintf(os.Stderr, "cmd/go: gccgo: %s\n", gccgoErr)
-	os.Exit(2)
+	base.SetExitStatus(2)
+	base.Exit()
 }
 
 func (tools gccgoToolchain) gc(b *Builder, a *Action, archive string, importcfg []byte, symabis string, asmhdr bool, gofiles []string) (ofile string, output []byte, err error) {
diff --git a/libgo/go/cmd/go/internal/work/init.go b/libgo/go/cmd/go/internal/work/init.go
index 693a53e..3381ab5 100644
--- a/libgo/go/cmd/go/internal/work/init.go
+++ b/libgo/go/cmd/go/internal/work/init.go
@@ -29,7 +29,8 @@ func BuildInit() {
 		p, err := filepath.Abs(cfg.BuildPkgdir)
 		if err != nil {
 			fmt.Fprintf(os.Stderr, "go %s: evaluating -pkgdir: %v\n", flag.Args()[0], err)
-			os.Exit(2)
+			base.SetExitStatus(2)
+			base.Exit()
 		}
 		cfg.BuildPkgdir = p
 	}
@@ -41,16 +42,19 @@ func instrumentInit() {
 	}
 	if cfg.BuildRace && cfg.BuildMSan {
 		fmt.Fprintf(os.Stderr, "go %s: may not use -race and -msan simultaneously\n", flag.Args()[0])
-		os.Exit(2)
+		base.SetExitStatus(2)
+		base.Exit()
 	}
 	if cfg.BuildMSan && !sys.MSanSupported(cfg.Goos, cfg.Goarch) {
 		fmt.Fprintf(os.Stderr, "-msan is not supported on %s/%s\n", cfg.Goos, cfg.Goarch)
-		os.Exit(2)
+		base.SetExitStatus(2)
+		base.Exit()
 	}
 	if cfg.BuildRace {
 		if !sys.RaceDetectorSupported(cfg.Goos, cfg.Goarch) {
 			fmt.Fprintf(os.Stderr, "go %s: -race is only supported on linux/amd64, linux/ppc64le, linux/arm64, freebsd/amd64, netbsd/amd64, darwin/amd64 and windows/amd64\n", flag.Args()[0])
-			os.Exit(2)
+			base.SetExitStatus(2)
+			base.Exit()
 		}
 	}
 	mode := "race"
@@ -61,7 +65,8 @@ func instrumentInit() {
 
 	if !cfg.BuildContext.CgoEnabled {
 		fmt.Fprintf(os.Stderr, "go %s: %s requires cgo; enable cgo by setting CGO_ENABLED=1\n", flag.Args()[0], modeFlag)
-		os.Exit(2)
+		base.SetExitStatus(2)
+		base.Exit()
 	}
 	forcedGcflags = append(forcedGcflags, modeFlag)
 	forcedLdflags = append(forcedLdflags, modeFlag)
diff --git a/libgo/go/cmd/go/script_test.go b/libgo/go/cmd/go/script_test.go
index f6facfd..1acc61f 100644
--- a/libgo/go/cmd/go/script_test.go
+++ b/libgo/go/cmd/go/script_test.go
@@ -400,6 +400,7 @@ func (ts *testScript) cmdCc(neg bool, args []string) {
 	var b work.Builder
 	b.Init()
 	ts.cmdExec(neg, append(b.GccCmd(".", ""), args...))
+	os.RemoveAll(b.WorkDir)
 }
 
 // cd changes to a different directory.