proc/gdbserial,dlv/cmds: make logGdbWire command line configurable

cmd/dlv/cmds/commands.go

@@ -14,6 +14,7 @@ import (
 
 	"github.com/derekparker/delve/pkg/config"
 	"github.com/derekparker/delve/pkg/goversion"
+	"github.com/derekparker/delve/pkg/logflags"
 	"github.com/derekparker/delve/pkg/terminal"
 	"github.com/derekparker/delve/pkg/version"
 	"github.com/derekparker/delve/service"
@@ -25,7 +26,7 @@ import (
 
 var (
 	// Log is whether to log debug statements.
-	Log bool
+	Log string
 	// Headless is whether to run without terminal.
 	Headless bool
 	// APIVersion is the requested API version while running headless
@@ -85,7 +86,11 @@ func New(docCall bool) *cobra.Command {
 	}
 
 	RootCommand.PersistentFlags().StringVarP(&Addr, "listen", "l", "localhost:0", "Debugging server listen address.")
-	RootCommand.PersistentFlags().BoolVarP(&Log, "log", "", false, "Enable debugging server logging.")
+	RootCommand.PersistentFlags().StringVarP(&Log, "log", "", "false", `Comma separated list of components that should produce debug output, possible values:
+	debugger	Log debugger commands
+	gdbwire		Log connection to gdbserial backend
+	lldbout		Copy output from debugserver/lldb to standard output
+`)
 	RootCommand.PersistentFlags().BoolVarP(&Headless, "headless", "", false, "Run debug server only, in headless mode.")
 	RootCommand.PersistentFlags().BoolVarP(&AcceptMulti, "accept-multiclient", "", false, "Allows a headless server to accept multiple client connections. Note that the server API is not reentrant and clients will have to coordinate.")
 	RootCommand.PersistentFlags().IntVar(&APIVersion, "api-version", 1, "Selects API version when headless.")
@@ -304,6 +309,7 @@ func debugCmd(cmd *cobra.Command, args []string) {
 
 func traceCmd(cmd *cobra.Command, args []string) {
 	status := func() int {
+		logflags.Setup(Log)
 
 		debugname, err := filepath.Abs(cmd.Flag("output").Value.String())
 		if err != nil {
@@ -348,7 +354,7 @@ func traceCmd(cmd *cobra.Command, args []string) {
 			APIVersion:  2,
 			WorkingDir:  WorkingDir,
 			Backend:     Backend,
-		}, Log)
+		}, logflags.Debugger())
 		if err := server.Run(); err != nil {
 			fmt.Fprintln(os.Stderr, err)
 			return 1
@@ -455,6 +461,8 @@ const (
 )
 
 func execute(attachPid int, processArgs []string, conf *config.Config, coreFile string, kind executeKind) int {
+	logflags.Setup(Log)
+
 	// Make a TCP listener
 	listener, err := net.Listen("tcp", Addr)
 	if err != nil {
@@ -488,7 +496,7 @@ func execute(attachPid int, processArgs []string, conf *config.Config, coreFile
 			CoreFile:    coreFile,
 
 			DisconnectChan: disconnectChan,
-		}, Log)
+		}, logflags.Debugger())
 	default:
 		fmt.Printf("Unknown API version: %d\n", APIVersion)
 		return 1

pkg/logflags/logflags.go

@@ -0,0 +1,43 @@
+package logflags
+
+import "strings"
+
+var debugger = false
+var gdbWire = false
+var lldbServerOutput = false
+
+// GdbWire returns true if the gdbserial package should log all the packets
+// exchanged with the stub.
+func GdbWire() bool {
+	return gdbWire
+}
+
+// Debugger returns true if the debugger package should log.
+func Debugger() bool {
+	return debugger
+}
+
+// LLDBServerOutput returns true if the output of the LLDB server should be
+// redirected to standard output instead of suppressed.
+func LLDBServerOutput() bool {
+	return lldbServerOutput
+}
+
+// Setup sets debugger flags based on the contents of logstr.
+func Setup(logstr string) {
+	if logstr == "true" || logstr == "" {
+		debugger = true
+		return
+	}
+	v := strings.Split(logstr, ",")
+	for _, logcmd := range v {
+		switch logcmd {
+		case "debugger":
+			debugger = true
+		case "gdbwire":
+			gdbWire = true
+		case "lldbout":
+			lldbServerOutput = true
+		}
+	}
+}

pkg/proc/gdbserial/gdbserver.go

@@ -79,14 +79,13 @@ import (
 
 	"golang.org/x/arch/x86/x86asm"
 
+	"github.com/derekparker/delve/pkg/logflags"
 	"github.com/derekparker/delve/pkg/proc"
 )
 
 const (
-	logGdbWire               = false
+	gdbWireFullStopPacket = false
-	logGdbWireFullStopPacket = false
+	gdbWireMaxLen         = 120
-	showLldbServerOutput     = false
-	logGdbWireMaxLen         = 120
 
 	maxTransmitAttempts    = 3    // number of retransmission attempts on failed checksum
 	initialInputBufferSize = 2048 // size of the input buffer for gdbConn
@@ -424,7 +423,7 @@ func LLDBLaunch(cmd []string, wd string) (*Process, error) {
 		proc = exec.Command("lldb-server", args...)
 	}
 
-	if showLldbServerOutput || logGdbWire {
+	if logflags.LLDBServerOutput() || logflags.GdbWire() {
 		proc.Stdout = os.Stdout
 		proc.Stderr = os.Stderr
 	}

pkg/proc/gdbserial/gdbserver_conn.go

@@ -16,6 +16,7 @@ import (
 	"sync"
 	"time"
 
+	"github.com/derekparker/delve/pkg/logflags"
 	"github.com/derekparker/delve/pkg/proc"
 )
 
@@ -632,7 +633,7 @@ func (conn *gdbConn) parseStopPacket(resp []byte, threadID string, tu *threadUpd
 		}
 		sp.sig = uint8(sig)
 
-		if logGdbWire && logGdbWireFullStopPacket {
+		if logflags.GdbWire() && gdbWireFullStopPacket {
 			fmt.Fprintf(os.Stderr, "full stop packet: %s\n", string(resp))
 		}
 
@@ -704,7 +705,7 @@ const ctrlC = 0x03 // the ASCII character for ^C
 
 // executes a ctrl-C on the line
 func (conn *gdbConn) sendCtrlC() error {
-	if logGdbWire {
+	if logflags.GdbWire() {
 		fmt.Println("<- interrupt")
 	}
 	_, err := conn.conn.Write([]byte{ctrlC})
@@ -991,9 +992,9 @@ func (conn *gdbConn) send(cmd []byte) error {
 
 	attempt := 0
 	for {
-		if logGdbWire {
+		if logflags.GdbWire() {
-			if len(cmd) > logGdbWireMaxLen {
+			if len(cmd) > gdbWireMaxLen {
-				fmt.Printf("<- %s...\n", string(cmd[:logGdbWireMaxLen]))
+				fmt.Printf("<- %s...\n", string(cmd[:gdbWireMaxLen]))
 			} else {
 				fmt.Printf("<- %s\n", string(cmd))
 			}
@@ -1032,15 +1033,15 @@ func (conn *gdbConn) recv(cmd []byte, context string, binary bool) (resp []byte,
 		if err != nil {
 			return nil, err
 		}
-		if logGdbWire {
+		if logflags.GdbWire() {
 			out := resp
 			partial := false
 			if idx := bytes.Index(out, []byte{'\n'}); idx >= 0 {
 				out = resp[:idx]
 				partial = true
 			}
-			if len(out) > logGdbWireMaxLen {
+			if len(out) > gdbWireMaxLen {
-				out = out[:logGdbWireMaxLen]
+				out = out[:gdbWireMaxLen]
 				partial = true
 			}
 			if !partial {
@@ -1097,7 +1098,7 @@ func (conn *gdbConn) readack() bool {
 	if err != nil {
 		return false
 	}
-	if logGdbWire {
+	if logflags.GdbWire() {
 		fmt.Printf("-> %s\n", string(b))
 	}
 	return b == '+'
@@ -1109,7 +1110,7 @@ func (conn *gdbConn) sendack(c byte) {
 		panic(fmt.Errorf("sendack(%c)", c))
 	}
 	conn.conn.Write([]byte{c})
-	if logGdbWire {
+	if logflags.GdbWire() {
 		fmt.Printf("<- %s\n", string(c))
 	}
 }