blob: a2f9be9f7e22d945a269a4ea500644c0e2192a2d [file] [log] [blame]
// Copyright 2018 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package cmd
import (
// Serve is a struct that exposes the configurable parts of the LSP server as
// flags, in the right form for tool.Main to consume.
type Serve struct {
Logfile string `flag:"logfile" help:"filename to log to. if value is \"auto\", then logging to a default output file is enabled"`
Mode string `flag:"mode" help:"no effect"`
Port int `flag:"port" help:"port on which to run gopls for debugging purposes"`
Address string `flag:"listen" help:"address on which to listen for remote connections. If prefixed by 'unix;', the subsequent address is assumed to be a unix domain socket. Otherwise, TCP is used."`
IdleTimeout time.Duration `flag:"listen.timeout" help:"when used with -listen, shut down the server when there are no connected clients for this duration"`
Trace bool `flag:"rpc.trace" help:"print the full rpc trace in lsp inspector format"`
Debug string `flag:"debug" help:"serve debug information on the supplied address"`
RemoteListenTimeout time.Duration `flag:"remote.listen.timeout" help:"when used with -remote=auto, the -listen.timeout value used to start the daemon"`
RemoteDebug string `flag:"remote.debug" help:"when used with -remote=auto, the -debug value used to start the daemon"`
RemoteLogfile string `flag:"remote.logfile" help:"when used with -remote=auto, the -logfile value used to start the daemon"`
app *Application
func (s *Serve) Name() string { return "serve" }
func (s *Serve) Parent() string { return }
func (s *Serve) Usage() string { return "[server-flags]" }
func (s *Serve) ShortHelp() string {
return "run a server for Go code using the Language Server Protocol"
func (s *Serve) DetailedHelp(f *flag.FlagSet) {
fmt.Fprint(f.Output(), ` gopls [flags] [server-flags]
The server communicates using JSONRPC2 on stdin and stdout, and is intended to be run directly as
a child of an editor process.
func (s *Serve) remoteArgs(network, address string) []string {
args := []string{"serve",
"-listen", fmt.Sprintf(`%s;%s`, network, address),
if s.RemoteDebug != "" {
args = append(args, "-debug", s.RemoteDebug)
if s.RemoteListenTimeout != 0 {
args = append(args, "-listen.timeout", s.RemoteListenTimeout.String())
if s.RemoteLogfile != "" {
args = append(args, "-logfile", s.RemoteLogfile)
return args
// Run configures a server based on the flags, and then runs it.
// It blocks until the server shuts down.
func (s *Serve) Run(ctx context.Context, args ...string) error {
if len(args) > 0 {
return tool.CommandLineErrorf("server does not take arguments, got %v", args)
di := debug.GetInstance(ctx)
isDaemon := s.Address != "" || s.Port != 0
if di != nil {
closeLog, err := di.SetLogFile(s.Logfile, isDaemon)
if err != nil {
return err
defer closeLog()
di.ServerAddress = s.Address
di.Serve(ctx, s.Debug)
var ss jsonrpc2.StreamServer
if != "" {
var err error
ss, err = lsprpc.NewForwarder(, s.remoteArgs)
if err != nil {
return fmt.Errorf("creating forwarder: %w", err)
} else {
ss = lsprpc.NewStreamServer(cache.New(nil), isDaemon,
var network, addr string
if s.Address != "" {
network, addr = lsprpc.ParseAddr(s.Address)
if s.Port != 0 {
network = "tcp"
// TODO(adonovan): should gopls ever be listening on network
// sockets, or only local ones?
// Ian says this was added in anticipation of
// something related to "VS Code remote" that turned
// out to be unnecessary. So I propose we limit it to
// localhost, if only so that we avoid the macOS
// firewall prompt.
// Hana says: "s.Address is for the remote access (LSP)
// and s.Port is for debugging purpose (according to
// the Server type documentation). I am not sure why the
// existing code here is mixing up and overwriting addr.
// For debugging endpoint, I think localhost makes perfect sense."
// TODO(adonovan): disentangle Address and Port,
// and use only localhost for the latter.
addr = fmt.Sprintf(":%v", s.Port)
if addr != "" {
log.Printf("Gopls daemon: listening on %s network, address %s...", network, addr)
defer log.Printf("Gopls daemon: exiting")
return jsonrpc2.ListenAndServe(ctx, network, addr, ss, s.IdleTimeout)
stream := jsonrpc2.NewHeaderStream(fakenet.NewConn("stdio", os.Stdin, os.Stdout))
if s.Trace && di != nil {
stream = protocol.LoggingStream(stream, di.LogWriter)
conn := jsonrpc2.NewConn(stream)
err := ss.ServeStream(ctx, conn)
if errors.Is(err, io.EOF) {
return nil
return err