Implement break command

command/command.go

@@ -7,7 +7,7 @@ import (
 	"os"
 )
 
-type cmdfunc func() error
+type cmdfunc func(args ...string) error
 
 type Commands struct {
 	cmds map[string]cmdfunc
@@ -44,15 +44,21 @@ func (c *Commands) Find(cmdstr string) cmdfunc {
 	return cmd
 }
 
-func noCmdAvailable() error {
+func CommandFunc(fn func() error) cmdfunc {
+	return func(args ...string) error {
+		return fn()
+	}
+}
+
+func noCmdAvailable(args ...string) error {
 	return fmt.Errorf("command not available")
 }
 
-func exitFunc() error {
+func exitFunc(args ...string) error {
 	os.Exit(0)
 	return nil
 }
 
-func nullCommand() error {
+func nullCommand(args ...string) error {
 	return nil
 }

command/command_test.go

@@ -24,7 +24,7 @@ func TestCommandDefault(t *testing.T) {
 func TestCommandRegister(t *testing.T) {
 	cmds := Commands{make(map[string]cmdfunc)}
 
-	cmds.Register("foo", func() error { return fmt.Errorf("registered command") })
+	cmds.Register("foo", func(args ...string) error { return fmt.Errorf("registered command") })
 
 	cmd := cmds.Find("foo")
 
@@ -40,7 +40,7 @@ func TestCommandRegister(t *testing.T) {
 
 func TestCommandReplay(t *testing.T) {
 	cmds := DebugCommands()
-	cmds.Register("foo", func() error { return fmt.Errorf("registered command") })
+	cmds.Register("foo", func(args ...string) error { return fmt.Errorf("registered command") })
 	cmd := cmds.Find("foo")
 
 	err := cmd()

fixtures/livetestprog.go

@@ -6,12 +6,22 @@ import (
 	"time"
 )
 
+func printPid(pid int) {
+	fmt.Println(pid)
+}
+
+func sayhi() {
+	fmt.Println("hi")
+}
+
 func main() {
 	pid := os.Getpid()
-	fmt.Println(pid)
+	printPid(pid)
 
 	time.Sleep(3 * time.Second)
 	for {
-		fmt.Println(pid)
+		printPid(pid)
+		time.Sleep(3 * time.Millisecond)
+		sayhi()
 	}
 }

main.go

@@ -47,8 +47,10 @@ func main() {
 			printStderrAndDie("Prompt for input failed.\n")
 		}
 
+		cmdstr, args := parseCommand(cmdstr)
+
 		cmd := cmds.Find(cmdstr)
-		err = cmd()
+		err = cmd(args...)
 		if err != nil {
 			fmt.Fprintf(os.Stderr, "Command failed: %s\n", err)
 		}
@@ -61,8 +63,19 @@ func printStderrAndDie(args ...interface{}) {
 }
 
 func registerProcessCommands(cmds *command.Commands, proc *proctl.DebuggedProcess) {
-	cmds.Register("step", proc.Step)
-	cmds.Register("continue", proc.Continue)
+	cmds.Register("step", command.CommandFunc(proc.Step))
+	cmds.Register("continue", command.CommandFunc(proc.Continue))
+	cmds.Register("break", func(args ...string) error {
+		fname := args[0]
+		bp, err := proc.Break(fname)
+		if err != nil {
+			return err
+		}
+
+		fmt.Printf("Breakpoint set at %#v for %s %s:%d\n", bp.Addr, bp.FunctionName, bp.File, bp.Line)
+
+		return nil
+	})
 }
 
 func newTerm() *term {
@@ -71,6 +84,11 @@ func newTerm() *term {
 	}
 }
 
+func parseCommand(cmdstr string) (string, []string) {
+	vals := strings.Split(cmdstr, " ")
+	return vals[0], vals[1:]
+}
+
 func (t *term) promptForInput() (string, error) {
 	fmt.Print("dbg> ")