misc/dist: add -version flag to override version name

Also, don't build the tour when making the source distribution.

R=golang-dev, dsymonds
CC=golang-dev
https://golang.org/cl/8354043

misc/dist/bindist.go

@@ -37,6 +37,7 @@ var (
 	wxsFile         = flag.String("wxs", "", "path to custom installer.wxs")
 	addLabel        = flag.String("label", "", "additional label to apply to file when uploading")
 	includeRace     = flag.Bool("race", true, "build race detector packages")
+	versionOverride = flag.String("version", "", "override version name")
 
 	username, password string // for Google Code upload
 )
@@ -184,11 +185,10 @@ func (b *Build) Do() error {
 		} else {
 			_, err = b.run(src, "bash", "make.bash")
 		}
-	}
+		if *includeRace {
 			if err != nil {
 				return err
 			}
-	if !b.Source && *includeRace {
 			goCmd := filepath.Join(b.root, "bin", "go")
 			if b.OS == "windows" {
 				goCmd += ".exe"
@@ -200,12 +200,13 @@ func (b *Build) Do() error {
 			// Re-install std without -race, so that we're not left with
 			// a slower, race-enabled cmd/go, cmd/godoc, etc.
 			_, err = b.run(src, goCmd, "install", "-a", "std")
+		}
 		if err != nil {
 			return err
 		}
+		err = b.tour()
 	}
-
-	if err := b.tour(); err != nil {
+	if err != nil {
 		return err
 	}
 
@@ -229,6 +230,9 @@ func (b *Build) Do() error {
 	fullVersion = bytes.TrimSpace(fullVersion)
 	v := bytes.SplitN(fullVersion, []byte(" "), 2)
 	version = string(v[0])
+	if *versionOverride != "" {
+		version = *versionOverride
+	}
 
 	// Write VERSION file.
 	err = ioutil.WriteFile(filepath.Join(b.root, "VERSION"), fullVersion, 0644)
@@ -522,7 +526,12 @@ func (b *Build) Upload(version string, filename string) error {
 		ftype = "Source"
 		summary = fmt.Sprintf("%s (source only)", version)
 	}
-	labels = append(labels, "OpSys-"+opsys, "Type-"+ftype)
+	if opsys != "" {
+		labels = append(labels, "OpSys-"+opsys)
+	}
+	if ftype != "" {
+		labels = append(labels, "Type-"+ftype)
+	}
 	if *addLabel != "" {
 		labels = append(labels, *addLabel)
 	}