proc/gdbserial: return error if stopped with a sginal

On macOS we can also stop when we receive a signal,
propagate this reason upwards to the client.

Also clear internal breakpoints after an unrecovered-panic since they
can not be reached anymore.

Fixes #872

pkg/proc/gdbserial/gdbserver.go

@@ -321,7 +321,7 @@ func (p *Process) Connect(conn net.Conn, path string, pid int) error {
 	if err == nil {
 		bp, err := p.SetBreakpoint(panicpc, proc.UserBreakpoint, nil)
 		if err == nil {
-			bp.Name = "unrecovered-panic"
+			bp.Name = proc.UnrecoveredPanic
 			bp.Variables = []string{"runtime.curg._panic.arg"}
 			bp.ID = -1
 			p.breakpointIDCounter--
@@ -631,7 +631,22 @@ continueLoop:
 
 	for _, thread := range p.threads {
 		if thread.strID == threadID {
-			return thread, nil
+			var err error = nil
+			switch sig {
+			case 0x91:
+				err = errors.New("bad access")
+			case 0x92:
+				err = errors.New("bad instruction")
+			case 0x93:
+				err = errors.New("arithmetic exception")
+			case 0x94:
+				err = errors.New("emulation exception")
+			case 0x95:
+				err = errors.New("software exception")
+			case 0x96:
+				err = errors.New("breakpoint exception")
+			}
+			return thread, err
 		}
 	}
 

pkg/proc/native/proc.go

@@ -408,7 +408,7 @@ func initializeDebugProcess(dbp *Process, path string) (*Process, error) {
 	if err == nil {
 		bp, err := dbp.SetBreakpoint(panicpc, proc.UserBreakpoint, nil)
 		if err == nil {
-			bp.Name = "unrecovered-panic"
+			bp.Name = proc.UnrecoveredPanic
 			bp.Variables = []string{"runtime.curg._panic.arg"}
 			bp.ID = -1
 			dbp.breakpointIDCounter--

pkg/proc/proc.go

@@ -19,6 +19,8 @@ type functionDebugInfo struct {
 var NotExecutableErr = errors.New("not an executable file")
 var NotRecordedErr = errors.New("not a recording")
 
+const UnrecoveredPanic = "unrecovered-panic"
+
 // ProcessExitedError indicates that the process has exited and contains both
 // process id and exit status.
 type ProcessExitedError struct {
@@ -169,6 +171,9 @@ func Continue(dbp Process) error {
 					return err
 				}
 			}
+			if curbp.Name == UnrecoveredPanic {
+				dbp.ClearInternalBreakpoints()
+			}
 			return conditionErrors(threads)
 		default:
 			// not a manual stop, not on runtime.Breakpoint, not on a breakpoint, just repeat

pkg/proc/proc_test.go

@@ -1871,7 +1871,7 @@ func TestPanicBreakpoint(t *testing.T) {
 	withTestProcess("panic", t, func(p proc.Process, fixture protest.Fixture) {
 		assertNoError(proc.Continue(p), t, "Continue()")
 		bp, _, _ := p.CurrentThread().Breakpoint()
-		if bp == nil || bp.Name != "unrecovered-panic" {
+		if bp == nil || bp.Name != proc.UnrecoveredPanic {
 			t.Fatalf("not on unrecovered-panic breakpoint: %v", bp)
 		}
 	})
@@ -1881,7 +1881,7 @@ func TestCmdLineArgs(t *testing.T) {
 	expectSuccess := func(p proc.Process, fixture protest.Fixture) {
 		err := proc.Continue(p)
 		bp, _, _ := p.CurrentThread().Breakpoint()
-		if bp != nil && bp.Name == "unrecovered-panic" {
+		if bp != nil && bp.Name == proc.UnrecoveredPanic {
 			t.Fatalf("testing args failed on unrecovered-panic breakpoint: %v", bp)
 		}
 		exit, exited := err.(proc.ProcessExitedError)
@@ -1897,7 +1897,7 @@ func TestCmdLineArgs(t *testing.T) {
 	expectPanic := func(p proc.Process, fixture protest.Fixture) {
 		proc.Continue(p)
 		bp, _, _ := p.CurrentThread().Breakpoint()
-		if bp == nil || bp.Name != "unrecovered-panic" {
+		if bp == nil || bp.Name != proc.UnrecoveredPanic {
 			t.Fatalf("not on unrecovered-panic breakpoint: %v", bp)
 		}
 	}
@@ -2283,7 +2283,7 @@ func TestStepConcurrentDirect(t *testing.T) {
 		assertNoError(err, t, "ClearBreakpoint()")
 
 		for _, b := range p.Breakpoints() {
-			if b.Name == "unrecovered-panic" {
+			if b.Name == proc.UnrecoveredPanic {
 				_, err := p.ClearBreakpoint(b.Addr)
 				assertNoError(err, t, "ClearBreakpoint(unrecovered-panic)")
 				break
@@ -2354,7 +2354,7 @@ func TestStepConcurrentPtr(t *testing.T) {
 		assertNoError(err, t, "SetBreakpoint()")
 
 		for _, b := range p.Breakpoints() {
-			if b.Name == "unrecovered-panic" {
+			if b.Name == proc.UnrecoveredPanic {
 				_, err := p.ClearBreakpoint(b.Addr)
 				assertNoError(err, t, "ClearBreakpoint(unrecovered-panic)")
 				break

pkg/terminal/command.go

@@ -671,11 +671,18 @@ func restart(t *Term, ctx callContext, args string) error {
 	return nil
 }
 
+func printfileNoState(t *Term) {
+	if state, _ := t.client.GetState(); state != nil && state.CurrentThread != nil {
+		printfile(t, state.CurrentThread.File, state.CurrentThread.Line, true)
+	}
+}
+
 func cont(t *Term, ctx callContext, args string) error {
 	stateChan := t.client.Continue()
 	var state *api.DebuggerState
 	for state = range stateChan {
 		if state.Err != nil {
+			printfileNoState(t)
 			return state.Err
 		}
 		printcontext(t, state)
@@ -694,6 +701,7 @@ func continueUntilCompleteNext(t *Term, state *api.DebuggerState, op string) err
 		var state *api.DebuggerState
 		for state = range stateChan {
 			if state.Err != nil {
+				printfileNoState(t)
 				return state.Err
 			}
 			printcontext(t, state)
@@ -728,6 +736,7 @@ func step(t *Term, ctx callContext, args string) error {
 	}
 	state, err := t.client.Step()
 	if err != nil {
+		printfileNoState(t)
 		return err
 	}
 	printcontext(t, state)
@@ -740,6 +749,7 @@ func stepInstruction(t *Term, ctx callContext, args string) error {
 	}
 	state, err := t.client.StepInstruction()
 	if err != nil {
+		printfileNoState(t)
 		return err
 	}
 	printcontext(t, state)
@@ -753,6 +763,7 @@ func next(t *Term, ctx callContext, args string) error {
 	}
 	state, err := t.client.Next()
 	if err != nil {
+		printfileNoState(t)
 		return err
 	}
 	printcontext(t, state)
@@ -765,6 +776,7 @@ func stepout(t *Term, ctx callContext, args string) error {
 	}
 	state, err := t.client.StepOut()
 	if err != nil {
+		printfileNoState(t)
 		return err
 	}
 	printcontext(t, state)