l.FatalErr was an antipattern

cmd/syncthing/main.go

@@ -198,7 +198,9 @@ func main() {
 		dir := expandTilde(generateDir)
 
 		info, err := os.Stat(dir)
-		l.FatalErr(err)
+		if err != nil {
+			l.Fatalln("generate:", err)
+		}
 		if !info.IsDir() {
 			l.Fatalln(dir, "is not a directory")
 		}
@@ -212,7 +214,9 @@ func main() {
 
 		newCertificate(dir, "")
 		cert, err = loadCert(dir, "")
-		l.FatalErr(err)
+		if err != nil {
+			l.Fatalln("load cert:", err)
+		}
 		if err == nil {
 			l.Infoln("Node ID:", protocol.NewNodeID(cert.Certificate[0]))
 		}
@@ -303,7 +307,9 @@ func syncthingMain() {
 	if err != nil {
 		newCertificate(confDir, "")
 		cert, err = loadCert(confDir, "")
-		l.FatalErr(err)
+		if err != nil {
+			l.Fatalln("load cert:", err)
+		}
 	}
 
 	myID = protocol.NewNodeID(cert.Certificate[0])
@@ -352,11 +358,15 @@ func syncthingMain() {
 		}
 
 		port, err := getFreePort("127.0.0.1", 8080)
-		l.FatalErr(err)
+		if err != nil {
+			l.Fatalln("get free port (GUI):", err)
+		}
 		cfg.GUI.Address = fmt.Sprintf("127.0.0.1:%d", port)
 
 		port, err = getFreePort("0.0.0.0", 22000)
-		l.FatalErr(err)
+		if err != nil {
+			l.Fatalln("get free port (BEP):", err)
+		}
 		cfg.Options.ListenAddress = []string{fmt.Sprintf("0.0.0.0:%d", port)}
 
 		cfg.Save()
@@ -853,9 +863,13 @@ func listenTLS(conns chan *tls.Conn, addr string, tlsCfg *tls.Config) {
 	}
 
 	tcaddr, err := net.ResolveTCPAddr("tcp", addr)
-	l.FatalErr(err)
+	if err != nil {
+		l.Fatalln("listen (BEP):", err)
+	}
 	listener, err := net.ListenTCP("tcp", tcaddr)
-	l.FatalErr(err)
+	if err != nil {
+		l.Fatalln("listen (BEP):", err)
+	}
 
 	for {
 		conn, err := listener.Accept()
@@ -1000,7 +1014,9 @@ func ensureDir(dir string, mode int) {
 	fi, err := os.Stat(dir)
 	if os.IsNotExist(err) {
 		err := os.MkdirAll(dir, 0700)
-		l.FatalErr(err)
+		if err != nil {
+			l.Fatalln(err)
+		}
 	} else if mode >= 0 && err == nil && int(fi.Mode()&0777) != mode {
 		err := os.Chmod(dir, os.FileMode(mode))
 		// This can fail on crappy filesystems, nothing we can do about it.

cmd/syncthing/tls.go

@@ -45,7 +45,9 @@ func newCertificate(dir string, prefix string) {
 	l.Infoln("Generating RSA key and certificate...")
 
 	priv, err := rsa.GenerateKey(rand.Reader, tlsRSABits)
-	l.FatalErr(err)
+	if err != nil {
+		l.Fatalln("generate key:", err)
+	}
 
 	notBefore := time.Now()
 	notAfter := time.Date(2049, 12, 31, 23, 59, 59, 0, time.UTC)
@@ -64,21 +66,35 @@ func newCertificate(dir string, prefix string) {
 	}
 
 	derBytes, err := x509.CreateCertificate(rand.Reader, &template, &template, &priv.PublicKey, priv)
-	l.FatalErr(err)
+	if err != nil {
+		l.Fatalln("create cert:", err)
+	}
 
 	certOut, err := os.Create(filepath.Join(dir, prefix+"cert.pem"))
-	l.FatalErr(err)
+	if err != nil {
+		l.Fatalln("save cert:", err)
+	}
 	err = pem.Encode(certOut, &pem.Block{Type: "CERTIFICATE", Bytes: derBytes})
-	l.FatalErr(err)
+	if err != nil {
+		l.Fatalln("save cert:", err)
+	}
 	err = certOut.Close()
-	l.FatalErr(err)
+	if err != nil {
+		l.Fatalln("save cert:", err)
+	}
 
 	keyOut, err := os.OpenFile(filepath.Join(dir, prefix+"key.pem"), os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0600)
-	l.FatalErr(err)
+	if err != nil {
+		l.Fatalln("save key:", err)
+	}
 	err = pem.Encode(keyOut, &pem.Block{Type: "RSA PRIVATE KEY", Bytes: x509.MarshalPKCS1PrivateKey(priv)})
-	l.FatalErr(err)
+	if err != nil {
+		l.Fatalln("save key:", err)
+	}
 	err = keyOut.Close()
-	l.FatalErr(err)
+	if err != nil {
+		l.Fatalln("save key:", err)
+	}
 }
 
 type DowngradingListener struct {

logger/logger.go

@@ -140,14 +140,3 @@ func (l *Logger) Fatalf(format string, vals ...interface{}) {
 	l.callHandlers(LevelFatal, s)
 	os.Exit(1)
 }
-
-func (l *Logger) FatalErr(err error) {
-	if err != nil {
-		l.mut.Lock()
-		defer l.mut.Unlock()
-		l.logger.SetFlags(l.logger.Flags() | log.Lshortfile)
-		l.logger.Output(2, "FATAL: "+err.Error())
-		l.callHandlers(LevelFatal, err.Error())
-		os.Exit(1)
-	}
-}