cmd/dist: rename variables + functions

This belongs to a series of clean-up changes (see below) for cmd/dist.
This is change (9).

These changes include:
(1)  apply minor fixes
(2)  restore behavior of branchtag
(3)  unleash bootstrap optimization for windows
(4)  use standard generated code header
(5)  remove trivial variables + functions
(6)  move functions for the better
(7)  simplify code segments
(8)  use bytes.Buffer for code generation
(9)  rename variables + functions

Change-Id: I9247433d7d07a2c99d15b0a4d23164bcbc042768
Reviewed-on: https://go-review.googlesource.com/61015
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

src/cmd/dist/build.go

@@ -95,7 +95,7 @@ func find(p string, l []string) int {
 func xinit() {
 	b := os.Getenv("GOROOT")
 	if b == "" {
-		fatal("$GOROOT must be set")
+		fatalf("$GOROOT must be set")
 	}
 	goroot = filepath.Clean(b)
 
@@ -117,7 +117,7 @@ func xinit() {
 	}
 	goos = b
 	if find(goos, okgoos) < 0 {
-		fatal("unknown $GOOS %s", goos)
+		fatalf("unknown $GOOS %s", goos)
 	}
 
 	b = os.Getenv("GOARM")
@@ -137,7 +137,7 @@ func xinit() {
 	go386 = b
 
 	if p := pathf("%s/src/all.bash", goroot); !isfile(p) {
-		fatal("$GOROOT is not set correctly or not exported\n"+
+		fatalf("$GOROOT is not set correctly or not exported\n"+
 			"\tGOROOT=%s\n"+
 			"\t%s does not exist", goroot, p)
 	}
@@ -147,7 +147,7 @@ func xinit() {
 		gohostarch = b
 	}
 	if find(gohostarch, okgoarch) < 0 {
-		fatal("unknown $GOHOSTARCH %s", gohostarch)
+		fatalf("unknown $GOHOSTARCH %s", gohostarch)
 	}
 
 	b = os.Getenv("GOARCH")
@@ -156,13 +156,13 @@ func xinit() {
 	}
 	goarch = b
 	if find(goarch, okgoarch) < 0 {
-		fatal("unknown $GOARCH %s", goarch)
+		fatalf("unknown $GOARCH %s", goarch)
 	}
 
 	b = os.Getenv("GO_EXTLINK_ENABLED")
 	if b != "" {
 		if b != "0" && b != "1" {
-			fatal("unknown $GO_EXTLINK_ENABLED %s", b)
+			fatalf("unknown $GO_EXTLINK_ENABLED %s", b)
 		}
 		goextlinkenabled = b
 	}
@@ -247,9 +247,9 @@ func chomp(s string) string {
 }
 
 func branchtag(branch string) (tag string, precise bool) {
-	b := run(goroot, CheckExit, "git", "log", "--decorate=full", "--format=format:%d", "master.."+branch)
+	log := run(goroot, CheckExit, "git", "log", "--decorate=full", "--format=format:%d", "master.."+branch)
 	tag = branch
-	for row, line := range strings.Split(b, "\n") {
+	for row, line := range strings.Split(log, "\n") {
 		// Each line is either blank, or looks like
 		//	  (tag: refs/tags/go1.4rc2, refs/remotes/origin/release-branch.go1.4, refs/heads/release-branch.go1.4)
 		// We need to find an element starting with refs/tags/.
@@ -301,7 +301,7 @@ func findgoversion() string {
 
 	// Show a nicer error message if this isn't a Git repo.
 	if !isGitRepo() {
-		fatal("FAILED: not a Git repo; must put a VERSION file in $GOROOT")
+		fatalf("FAILED: not a Git repo; must put a VERSION file in $GOROOT")
 	}
 
 	// Otherwise, use Git.
@@ -448,7 +448,7 @@ func setup() {
 	if strings.HasPrefix(goversion, "release.") || (strings.HasPrefix(goversion, "go") && !strings.Contains(goversion, "beta")) {
 		for _, dir := range unreleased {
 			if p := pathf("%s/%s", goroot, dir); isdir(p) {
-				fatal("%s should not exist in release build", p)
+				fatalf("%s should not exist in release build", p)
 			}
 		}
 	}
@@ -666,7 +666,7 @@ func install(dir string) {
 		}
 		// Did not rebuild p.
 		if find(p, missing) >= 0 {
-			fatal("missing file %s", p)
+			fatalf("missing file %s", p)
 		}
 	built:
 	}
@@ -987,7 +987,7 @@ func cmdbootstrap() {
 	xflagparse(0)
 
 	if isdir(pathf("%s/src/pkg", goroot)) {
-		fatal("\n\n"+
+		fatalf("\n\n"+
 			"The Go package sources have moved to $GOROOT/src.\n"+
 			"*** %s still exists. ***\n"+
 			"It probably contains stale files that may confuse the build.\n"+
@@ -1127,7 +1127,7 @@ func checkCC() {
 		if len(output) > 0 {
 			outputHdr = "\nCommand output:\n\n"
 		}
-		fatal("cannot invoke C compiler %q: %v\n\n"+
+		fatalf("cannot invoke C compiler %q: %v\n\n"+
 			"Go needs a system C compiler for use with cgo.\n"+
 			"To set a C compiler, set CC=the-compiler.\n"+
 			"To disable cgo, set CGO_ENABLED=0.\n%s%s", defaultcc, err, outputHdr, output)
@@ -1143,7 +1143,7 @@ func defaulttarg() string {
 	src := pathf("%s/src/", goroot)
 	real_src := xrealwd(src)
 	if !strings.HasPrefix(pwd, real_src) {
-		fatal("current directory %s is not under %s", pwd, real_src)
+		fatalf("current directory %s is not under %s", pwd, real_src)
 	}
 	pwd = pwd[len(real_src):]
 	// guard against xrealwd returning the directory without the trailing /
@@ -1247,9 +1247,9 @@ func cmdlist() {
 	}
 	out, err := json.MarshalIndent(results, "", "\t")
 	if err != nil {
-		fatal("json marshal error: %v", err)
+		fatalf("json marshal error: %v", err)
 	}
 	if _, err := os.Stdout.Write(out); err != nil {
-		fatal("write failed: %v", err)
+		fatalf("write failed: %v", err)
 	}
 }

src/cmd/dist/main.go

@@ -76,7 +76,7 @@ func main() {
 	case "plan9":
 		gohostarch = os.Getenv("objtype")
 		if gohostarch == "" {
-			fatal("$objtype is unset")
+			fatalf("$objtype is unset")
 		}
 	case "windows":
 		exe = ".exe"
@@ -117,7 +117,7 @@ func main() {
 				gohostarch = "arm"
 			}
 		default:
-			fatal("unknown architecture: %s", out)
+			fatalf("unknown architecture: %s", out)
 		}
 	}
 

src/cmd/dist/sys_windows.go

@@ -44,6 +44,6 @@ func sysinit() {
 	case PROCESSOR_ARCHITECTURE_INTEL:
 		gohostarch = "386"
 	default:
-		fatal("unknown processor architecture")
+		fatalf("unknown processor architecture")
 	}
 }

src/cmd/dist/util.go

@@ -62,7 +62,7 @@ var outputLock sync.Mutex
 // run runs the command line cmd in dir.
 // If mode has ShowOutput set and Background unset, run passes cmd's output to
 // stdout/stderr directly. Otherwise, run returns cmd's output as a string.
-// If mode has CheckExit set and the command fails, run calls fatal.
+// If mode has CheckExit set and the command fails, run calls fatalf.
 // If mode has Background set, this command is being run as a
 // Background job. Only bgrun should use the Background mode,
 // not other callers.
@@ -97,11 +97,11 @@ func run(dir string, mode int, cmd ...string) string {
 		}
 		outputLock.Unlock()
 		if mode&Background != 0 {
-			// Prevent fatal from waiting on our own goroutine's
+			// Prevent fatalf from waiting on our own goroutine's
 			// bghelper to exit:
 			bghelpers.Done()
 		}
-		fatal("FAILED: %v: %v", strings.Join(cmd, " "), err)
+		fatalf("FAILED: %v: %v", strings.Join(cmd, " "), err)
 	}
 	if mode&ShowOutput != 0 {
 		outputLock.Lock()
@@ -179,7 +179,7 @@ func bgwait(wg *sync.WaitGroup) {
 func xgetwd() string {
 	wd, err := os.Getwd()
 	if err != nil {
-		fatal("%s", err)
+		fatalf("%s", err)
 	}
 	return wd
 }
@@ -189,11 +189,11 @@ func xgetwd() string {
 func xrealwd(path string) string {
 	old := xgetwd()
 	if err := os.Chdir(path); err != nil {
-		fatal("chdir %s: %v", path, err)
+		fatalf("chdir %s: %v", path, err)
 	}
 	real := xgetwd()
 	if err := os.Chdir(old); err != nil {
-		fatal("chdir %s: %v", old, err)
+		fatalf("chdir %s: %v", old, err)
 	}
 	return real
 }
@@ -223,7 +223,7 @@ func mtime(p string) time.Time {
 func readfile(file string) string {
 	data, err := ioutil.ReadFile(file)
 	if err != nil {
-		fatal("%v", err)
+		fatalf("%v", err)
 	}
 	return string(data)
 }
@@ -233,12 +233,12 @@ const (
 	writeSkipSame
 )
 
-// writefile writes b to the named file, creating it if needed.
+// writefile writes text to the named file, creating it if needed.
 // if exec is non-zero, marks the file as executable.
 // If the file already exists and has the expected content,
 // it is not rewritten, to avoid changing the time stamp.
-func writefile(b, file string, flag int) {
-	new := []byte(b)
+func writefile(text, file string, flag int) {
+	new := []byte(text)
 	if flag&writeSkipSame != 0 {
 		old, err := ioutil.ReadFile(file)
 		if err == nil && bytes.Equal(old, new) {
@@ -251,7 +251,7 @@ func writefile(b, file string, flag int) {
 	}
 	err := ioutil.WriteFile(file, new, mode)
 	if err != nil {
-		fatal("%v", err)
+		fatalf("%v", err)
 	}
 }
 
@@ -259,7 +259,7 @@ func writefile(b, file string, flag int) {
 func xmkdir(p string) {
 	err := os.Mkdir(p, 0777)
 	if err != nil {
-		fatal("%v", err)
+		fatalf("%v", err)
 	}
 }
 
@@ -267,7 +267,7 @@ func xmkdir(p string) {
 func xmkdirall(p string) {
 	err := os.MkdirAll(p, 0777)
 	if err != nil {
-		fatal("%v", err)
+		fatalf("%v", err)
 	}
 }
 
@@ -292,12 +292,12 @@ func xremoveall(p string) {
 func xreaddir(dir string) []string {
 	f, err := os.Open(dir)
 	if err != nil {
-		fatal("%v", err)
+		fatalf("%v", err)
 	}
 	defer f.Close()
 	names, err := f.Readdirnames(-1)
 	if err != nil {
-		fatal("reading %s: %v", dir, err)
+		fatalf("reading %s: %v", dir, err)
 	}
 	return names
 }
@@ -307,12 +307,12 @@ func xreaddir(dir string) []string {
 func xreaddirfiles(dir string) []string {
 	f, err := os.Open(dir)
 	if err != nil {
-		fatal("%v", err)
+		fatalf("%v", err)
 	}
 	defer f.Close()
 	infos, err := f.Readdir(-1)
 	if err != nil {
-		fatal("reading %s: %v", dir, err)
+		fatalf("reading %s: %v", dir, err)
 	}
 	var names []string
 	for _, fi := range infos {
@@ -328,13 +328,13 @@ func xreaddirfiles(dir string) []string {
 func xworkdir() string {
 	name, err := ioutil.TempDir("", "go-tool-dist-")
 	if err != nil {
-		fatal("%v", err)
+		fatalf("%v", err)
 	}
 	return name
 }
 
-// fatal prints an error message to standard error and exits.
-func fatal(format string, args ...interface{}) {
+// fatalf prints an error message to standard error and exits.
+func fatalf(format string, args ...interface{}) {
 	fmt.Fprintf(os.Stderr, "go tool dist: %s\n", fmt.Sprintf(format, args...))
 
 	dieOnce.Do(func() { close(dying) })
@@ -432,17 +432,17 @@ func elfIsLittleEndian(fn string) bool {
 	// debug/elf package.
 	file, err := os.Open(fn)
 	if err != nil {
-		fatal("failed to open file to determine endianness: %v", err)
+		fatalf("failed to open file to determine endianness: %v", err)
 	}
 	defer file.Close()
 	var hdr [16]byte
 	if _, err := io.ReadFull(file, hdr[:]); err != nil {
-		fatal("failed to read ELF header to determine endianness: %v", err)
+		fatalf("failed to read ELF header to determine endianness: %v", err)
 	}
 	// hdr[5] is EI_DATA byte, 1 is ELFDATA2LSB and 2 is ELFDATA2MSB
 	switch hdr[5] {
 	default:
-		fatal("unknown ELF endianness of %s: EI_DATA = %d", fn, hdr[5])
+		fatalf("unknown ELF endianness of %s: EI_DATA = %d", fn, hdr[5])
 	case 1:
 		return true
 	case 2: