cmd/syncthing: Extract flag parsing.

GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/3126

build.go

@@ -128,12 +128,7 @@ func main() {
 	// might have installed during "build.go setup".
 	os.Setenv("PATH", fmt.Sprintf("%s%cbin%c%s", os.Getenv("GOPATH"), os.PathSeparator, os.PathListSeparator, os.Getenv("PATH")))
 
-	flag.StringVar(&goarch, "goarch", runtime.GOARCH, "GOARCH")
-	flag.StringVar(&goos, "goos", runtime.GOOS, "GOOS")
-	flag.BoolVar(&noupgrade, "no-upgrade", noupgrade, "Disable upgrade functionality")
-	flag.StringVar(&version, "version", getVersion(), "Set compiled in version string")
-	flag.BoolVar(&race, "race", race, "Use race detector")
-	flag.Parse()
+	parseFlags()
 
 	switch goarch {
 	case "386", "amd64", "arm", "arm64", "ppc64", "ppc64le":
@@ -245,6 +240,15 @@ func setGoPath() {
 	os.Setenv("GOPATH", gopath)
 }
 
+func parseFlags() {
+	flag.StringVar(&goarch, "goarch", runtime.GOARCH, "GOARCH")
+	flag.StringVar(&goos, "goos", runtime.GOOS, "GOOS")
+	flag.BoolVar(&noupgrade, "no-upgrade", noupgrade, "Disable upgrade functionality")
+	flag.StringVar(&version, "version", getVersion(), "Set compiled in version string")
+	flag.BoolVar(&race, "race", race, "Use race detector")
+	flag.Parse()
+}
+
 func checkRequiredGoVersion() (float64, bool) {
 	re := regexp.MustCompile(`go(\d+\.\d+)`)
 	ver := runtime.Version()