cmd/dlv: add --client-addr flag to run dap with a predefined client

Documentation/usage/dlv_dap.md

@@ -17,9 +17,9 @@ The server does not yet accept multiple client connections (--accept-multiclient
 While --continue is not supported, stopOnEntry launch/attach attribute can be used to control if
 execution is resumed at the start of the debug session.
 
-The --connect flag is a special flag that makes the server operate in reverse mode.
-In this mode, Delve connects to a DAP client listening on host:port,
-instead of listening for connections.
+The --client-addr flag is a special flag that makes the server initiate a debug session
+by dialing in to the host:port where a DAP client is waiting. This server process
+will exit when the debug session ends.
 
 ```
 dlv dap
@@ -28,7 +28,7 @@ dlv dap
 ### Options
 
 ```
-      --connect string   host:port of the DAP client when running in reverse mode.
+      --client-addr string   host:port where the DAP client is waiting for the DAP server to dial in
 ```
 
 ### Options inherited from parent commands

cmd/dlv/cmds/commands.go

@@ -61,10 +61,10 @@ var (
 	// disableASLR is used to disable ASLR
 	disableASLR bool
 
-	// dapConnect is dap subcommand's flag that specifies the address of a DAP client.
-	// If it is specified, the dap server operates in reverse mode and
-	// and dials into the client waiting there.
-	dapConnect string
+	// dapClientAddr is dap subcommand's flag that specifies the address of a DAP client.
+	// If it is specified, the dap server starts a debug session by dialing to the client.
+	// The dap server will serve only for the debug session.
+	dapClientAddr string
 
 	// backend selection
 	backend string
@@ -192,12 +192,12 @@ The server does not yet accept multiple client connections (--accept-multiclient
 While --continue is not supported, stopOnEntry launch/attach attribute can be used to control if
 execution is resumed at the start of the debug session.
 
-The --connect flag is a special flag that makes the server operate in reverse mode.
-In this mode, Delve connects to a DAP client listening on host:port,
-instead of listening for connections.`,
+The --client-addr flag is a special flag that makes the server initiate a debug session
+by dialing in to the host:port where a DAP client is waiting. This server process
+will exit when the debug session ends.`,
 		Run: dapCmd,
 	}
-	dapCommand.Flags().StringVar(&dapConnect, "connect", "", "host:port of the DAP client when running in reverse mode.")
+	dapCommand.Flags().StringVar(&dapClientAddr, "client-addr", "", "host:port where the DAP client is waiting for the DAP server to dial in")
 
 	rootCommand.AddCommand(dapCommand)
 
@@ -449,7 +449,7 @@ func dapCmd(cmd *cobra.Command, args []string) {
 		var server *dap.Server
 		disconnectChan := make(chan struct{})
 
-		if dapConnect == "" {
+		if dapClientAddr == "" {
 			listener, err := net.Listen("tcp", addr)
 			if err != nil {
 				fmt.Printf("couldn't start listener: %s\n", err)
@@ -470,9 +470,9 @@ func dapCmd(cmd *cobra.Command, args []string) {
 		} else { // reverse mode
 			headless = true // TODO(github.com/go-delve/delve/issues/2552): consider the same for the normal mode.
 
-			conn, err := net.Dial("tcp", dapConnect)
+			conn, err := net.Dial("tcp", dapClientAddr)
 			if err != nil {
-				fmt.Fprintf(os.Stderr, "Failed to connect to the DAP proxy server: %v\n", err)
+				fmt.Fprintf(os.Stderr, "Failed to connect to the DAP client: %v\n", err)
 				return 1
 			}
 			server = dap.NewReverseServer(&service.Config{

cmd/dlv/dlv_test.go

@@ -656,7 +656,7 @@ func TestDapReverse(t *testing.T) {
 	dlvbin, tmpdir := getDlvBin(t)
 	defer os.RemoveAll(tmpdir)
 
-	cmd := exec.Command(dlvbin, "dap", "--log-output=dap", "--log", "--connect", listener.Addr().String())
+	cmd := exec.Command(dlvbin, "dap", "--log-output=dap", "--log", "--client-addr", listener.Addr().String())
 	buf := &bytes.Buffer{}
 	cmd.Stdin = buf
 	cmd.Stdout = buf
@@ -670,7 +670,7 @@ func TestDapReverse(t *testing.T) {
 	}
 	t.Log("dlv-reverse dialed in successfully")
 
-	client := daptest.NewClientWithConn(conn)
+	client := daptest.NewClientFromConn(conn)
 	client.InitializeRequest()
 	client.ExpectInitializeResponse(t)
 

service/dap/daptest/client.go

@@ -37,10 +37,12 @@ func NewClient(addr string) *Client {
 	if err != nil {
 		log.Fatal("dialing:", err)
 	}
-	return NewClientWithConn(conn)
+	return NewClientFromConn(conn)
 }
 
-func NewClientWithConn(conn net.Conn) *Client {
+// NewClientFromConn creates a new Client with the given TCP connection.
+// Call Close to close the connection.
+func NewClientFromConn(conn net.Conn) *Client {
 	c := &Client{conn: conn, reader: bufio.NewReader(conn)}
 	c.seq = 1 // match VS Code numbering
 	return c

service/dap/server.go

@@ -203,17 +203,17 @@ const (
 // disconnects or requests shutdown. Once config.DisconnectChan is closed,
 // Server.Stop() must be called to shutdown this single-user server.
 func NewServer(config *service.Config) *Server {
-	return newServer(config, nil, false)
+	return newServer(config, nil)
 }
 
 // NewReverseServer creates a special DAP server that operates in reverse mode.
 // Reverse DAP server is not actually running a TCP server listening on a port,
 // but communicates with the provided net.Conn only for a single debug session.
 func NewReverseServer(config *service.Config, conn net.Conn) *Server {
-	return newServer(config, conn, true)
+	return newServer(config, conn)
 }
 
-func newServer(config *service.Config, conn net.Conn, inReverseMode bool) *Server {
+func newServer(config *service.Config, conn net.Conn) *Server {
 	logger := logflags.DAPLogger()
 	if config.Listener != nil {
 		logflags.WriteDAPListeningMessage(config.Listener.Addr().String())