From 3facf7ecebdf10fbd48a87aabd688082c567b78c Mon Sep 17 00:00:00 2001

From: David Crawshaw <[email protected]>

Date: Wed, 4 Nov 2015 11:21:55 -0500

Subject: [PATCH 60/63] [release-branch.go1.5] misc/ios: keep whole buffer in

 go_darwin_arm_exec

The existing go_darwin_arm_exec.go script does not work with Xcode 7,

not due to any significant changes, but just ordering and timing of

statements from lldb. Unfortunately the current design of

go_darwin_arm_exec.go makes it not obvious what gets stuck where, so

this moves from a moving buffer window to a complete buffer of the

lldb output.

The result is easier code to follow, and it works with Xcode 7.

Updates #12660.

Change-Id: I3b8b890b0bf4474119482e95d84e821a86d1eaed

Reviewed-on: https://go-review.googlesource.com/16634

Reviewed-by: Michael Matloob <[email protected]>

Reviewed-on: https://go-review.googlesource.com/17146

---

 misc/ios/go_darwin_arm_exec.go | 366 +++++++++++++++++------------------------

 1 file changed, 149 insertions(+), 217 deletions(-)

diff --git a/misc/ios/go_darwin_arm_exec.go b/misc/ios/go_darwin_arm_exec.go

index debd2cd..3131b15 100644

--- a/misc/ios/go_darwin_arm_exec.go

+++ b/misc/ios/go_darwin_arm_exec.go

@@ -160,9 +160,6 @@ func run(bin string, args []string) (err error) {

 	}

 	defer os.Chdir(oldwd)

-	type waitPanic struct {

-		err error

-	}

 	defer func() {

 		if r := recover(); r != nil {

 			if w, ok := r.(waitPanic); ok {

@@ -174,14 +171,96 @@ func run(bin string, args []string) (err error) {

 	}()

 	defer exec.Command("killall", "ios-deploy").Run() // cleanup

-

 	exec.Command("killall", "ios-deploy").Run()

 	var opts options

 	opts, args = parseArgs(args)

 	// ios-deploy invokes lldb to give us a shell session with the app.

-	cmd = exec.Command(

+	s, err := newSession(appdir, args, opts)

+	if err != nil {

+		return err

+	}

+	defer func() {

+		b := s.out.Bytes()

+		if err == nil && !debug {

+			i := bytes.Index(b, []byte("(lldb) process continue"))

+			if i > 0 {

+				b = b[i:]

+			}

+		}

+		os.Stdout.Write(b)

+	}()

+

+	// Script LLDB. Oh dear.

+	s.do(`process handle SIGHUP  --stop false --pass true --notify false`)

+	s.do(`process handle SIGPIPE --stop false --pass true --notify false`)

+	s.do(`process handle SIGUSR1 --stop false --pass true --notify false`)

+	s.do(`process handle SIGSEGV --stop false --pass true --notify false`) // does not work

+	s.do(`process handle SIGBUS  --stop false --pass true --notify false`) // does not work

+

+	if opts.lldb {

+		_, err := io.Copy(s.in, os.Stdin)

+		if err != io.EOF {

+			return err

+		}

+		return nil

+	}

+

+	s.do(`breakpoint set -n getwd`) // in runtime/cgo/gcc_darwin_arm.go

+

+	s.doCmd("run", "stop reason = breakpoint", 20*time.Second)

+

+	// Move the current working directory into the faux gopath.

+	if pkgpath != "src" {

+		s.do(`breakpoint delete 1`)

+		s.do(`expr char* $mem = (char*)malloc(512)`)

+		s.do(`expr $mem = (char*)getwd($mem, 512)`)

+		s.do(`expr $mem = (char*)strcat($mem, "/` + pkgpath + `")`)

+		s.do(`call (void)chdir($mem)`)

+	}

+

+	startTestsLen := s.out.Len()

+	fmt.Fprintln(s.in, `process continue`)

+

+	passed := func(out *buf) bool {

+		// Just to make things fun, lldb sometimes translates \n into \r\n.

+		return s.out.LastIndex([]byte("\nPASS\n")) > startTestsLen ||

+			s.out.LastIndex([]byte("\nPASS\r")) > startTestsLen ||

+			s.out.LastIndex([]byte("\n(lldb) PASS\n")) > startTestsLen ||

+			s.out.LastIndex([]byte("\n(lldb) PASS\r")) > startTestsLen

+	}

+	err = s.wait("test completion", passed, opts.timeout)

+	if passed(s.out) {

+		// The returned lldb error code is usually non-zero.

+		// We check for test success by scanning for the final

+		// PASS returned by the test harness, assuming the worst

+		// in its absence.

+		return nil

+	}

+	return err

+}

+

+type lldbSession struct {

+	cmd      *exec.Cmd

+	in       *os.File

+	out      *buf

+	timedout chan struct{}

+	exited   chan error

+}

+

+func newSession(appdir string, args []string, opts options) (*lldbSession, error) {

+	lldbr, in, err := os.Pipe()

+	if err != nil {

+		return nil, err

+	}

+	s := &lldbSession{

+		in:     in,

+		out:    new(buf),

+		exited: make(chan error),

+	}

+

+	s.cmd = exec.Command(

 		// lldb tries to be clever with terminals.

 		// So we wrap it in script(1) and be clever

 		// right back at it.

@@ -198,267 +277,120 @@ func run(bin string, args []string) (err error) {

 		"--bundle", appdir,

 	)

 	if debug {

-		log.Println(strings.Join(cmd.Args, " "))

+		log.Println(strings.Join(s.cmd.Args, " "))

 	}

-	lldbr, lldb, err := os.Pipe()

-	if err != nil {

-		return err

-	}

-	w := new(bufWriter)

+	var out io.Writer = s.out

 	if opts.lldb {

-		mw := io.MultiWriter(w, os.Stderr)

-		cmd.Stdout = mw

-		cmd.Stderr = mw

-	} else {

-		cmd.Stdout = w

-		cmd.Stderr = w // everything of interest is on stderr

+		out = io.MultiWriter(out, os.Stderr)

 	}

-	cmd.Stdin = lldbr

+	s.cmd.Stdout = out

+	s.cmd.Stderr = out // everything of interest is on stderr

+	s.cmd.Stdin = lldbr

-	if err := cmd.Start(); err != nil {

-		return fmt.Errorf("ios-deploy failed to start: %v", err)

+	if err := s.cmd.Start(); err != nil {

+		return nil, fmt.Errorf("ios-deploy failed to start: %v", err)

 	}

 	// Manage the -test.timeout here, outside of the test. There is a lot

 	// of moving parts in an iOS test harness (notably lldb) that can

 	// swallow useful stdio or cause its own ruckus.

-	var timedout chan struct{}

 	if opts.timeout > 1*time.Second {

-		timedout = make(chan struct{})

+		s.timedout = make(chan struct{})

 		time.AfterFunc(opts.timeout-1*time.Second, func() {

-			close(timedout)

+			close(s.timedout)

 		})

 	}

-	exited := make(chan error)

 	go func() {

-		exited <- cmd.Wait()

+		s.exited <- s.cmd.Wait()

 	}()

-	waitFor := func(stage, str string, timeout time.Duration) error {

-		select {

-		case <-timedout:

-			w.printBuf()

-			if p := cmd.Process; p != nil {

-				p.Kill()

-			}

-			return fmt.Errorf("timeout (stage %s)", stage)

-		case err := <-exited:

-			w.printBuf()

-			return fmt.Errorf("failed (stage %s): %v", stage, err)

-		case i := <-w.find(str, timeout):

-			if i < 0 {

-				log.Printf("timed out on stage %q, retrying", stage)

-				return errRetry

-			}

-			w.clearTo(i + len(str))

-			return nil

-		}

+	cond := func(out *buf) bool {

+		i0 := s.out.LastIndex([]byte("(lldb)"))

+		i1 := s.out.LastIndex([]byte("fruitstrap"))

+		i2 := s.out.LastIndex([]byte(" connect"))

+		return i0 > 0 && i1 > 0 && i2 > 0

 	}

-	do := func(cmd string) {

-		fmt.Fprintln(lldb, cmd)

-		if err := waitFor(fmt.Sprintf("prompt after %q", cmd), "(lldb)", 0); err != nil {

-			panic(waitPanic{err})

-		}

+	if err := s.wait("lldb start", cond, 5*time.Second); err != nil {

+		fmt.Printf("lldb start error: %v\n", err)

+		return nil, errRetry

 	}

+	return s, nil

+}

-	// Wait for installation and connection.

-	if err := waitFor("ios-deploy before run", "(lldb)", 0); err != nil {

-		// Retry if we see a rare and longstanding ios-deploy bug.

-		// https://github.com/phonegap/ios-deploy/issues/11

-		//	Assertion failed: (AMDeviceStartService(device, CFSTR("com.apple.debugserver"), &gdbfd, NULL) == 0)

-		log.Printf("%v, retrying", err)

-		return errRetry

-	}

+func (s *lldbSession) do(cmd string) { s.doCmd(cmd, "(lldb)", 0) }

-	// Script LLDB. Oh dear.

-	do(`process handle SIGHUP  --stop false --pass true --notify false`)

-	do(`process handle SIGPIPE --stop false --pass true --notify false`)

-	do(`process handle SIGUSR1 --stop false --pass true --notify false`)

-	do(`process handle SIGSEGV --stop false --pass true --notify false`) // does not work

-	do(`process handle SIGBUS  --stop false --pass true --notify false`) // does not work

-

-	if opts.lldb {

-		_, err := io.Copy(lldb, os.Stdin)

-		if err != io.EOF {

-			return err

-		}

-		return nil

+func (s *lldbSession) doCmd(cmd string, waitFor string, extraTimeout time.Duration) {

+	startLen := s.out.Len()

+	fmt.Fprintln(s.in, cmd)

+	cond := func(out *buf) bool {

+		i := s.out.LastIndex([]byte(waitFor))

+		return i > startLen

 	}

-

-	do(`breakpoint set -n getwd`) // in runtime/cgo/gcc_darwin_arm.go

-

-	fmt.Fprintln(lldb, `run`)

-	if err := waitFor("br getwd", "stop reason = breakpoint", 20*time.Second); err != nil {

-		// At this point we see several flaky errors from the iOS

-		// build infrastructure. The most common is never reaching

-		// the breakpoint, which we catch with a timeout. Very

-		// occasionally lldb can produce errors like:

-		//

-		//	Breakpoint 1: no locations (pending).

-		//	WARNING:  Unable to resolve breakpoint to any actual locations.

-		//

-		// As no actual test code has been executed by this point,

-		// we treat all errors as recoverable.

-		if err != errRetry {

-			log.Printf("%v, retrying", err)

-			err = errRetry

-		}

-		return err

-	}

-	if err := waitFor("br getwd prompt", "(lldb)", 0); err != nil {

-		return err

+	if err := s.wait(fmt.Sprintf("running cmd %q", cmd), cond, extraTimeout); err != nil {

+		panic(waitPanic{err})

 	}

+}

-	// Move the current working directory into the faux gopath.

-	if pkgpath != "src" {

-		do(`breakpoint delete 1`)

-		do(`expr char* $mem = (char*)malloc(512)`)

-		do(`expr $mem = (char*)getwd($mem, 512)`)

-		do(`expr $mem = (char*)strcat($mem, "/` + pkgpath + `")`)

-		do(`call (void)chdir($mem)`)

-	}

-

-	// Run the tests.

-	w.trimSuffix("(lldb) ")

-	fmt.Fprintln(lldb, `process continue`)

-

-	// Wait for the test to complete.

-	select {

-	case <-timedout:

-		w.printBuf()

-		if p := cmd.Process; p != nil {

-			p.Kill()

-		}

-		return errors.New("timeout running tests")

-	case <-w.find("\nPASS", 0):

-		passed := w.isPass()

-		w.printBuf()

-		if passed {

-			return nil

-		}

-		return errors.New("test failure")

-	case err := <-exited:

-		// The returned lldb error code is usually non-zero.

-		// We check for test success by scanning for the final

-		// PASS returned by the test harness, assuming the worst

-		// in its absence.

-		if w.isPass() {

-			err = nil

-		} else if err == nil {

-			err = errors.New("test failure")

+func (s *lldbSession) wait(reason string, cond func(out *buf) bool, extraTimeout time.Duration) error {

+	doTimeout := 1*time.Second + extraTimeout

+	doTimedout := time.After(doTimeout)

+	for {

+		select {

+		case <-s.timedout:

+			if p := s.cmd.Process; p != nil {

+				p.Kill()

+			}

+			return fmt.Errorf("test timeout (%s)", reason)

+		case <-doTimedout:

+			return fmt.Errorf("command timeout (%s for %v)", reason, doTimeout)

+		case err := <-s.exited:

+			return fmt.Errorf("exited (%s: %v)", reason, err)

+		default:

+			if cond(s.out) {

+				return nil

+			}

+			time.Sleep(20 * time.Millisecond)

 		}

-		w.printBuf()

-		return err

 	}

 }

-type bufWriter struct {

-	mu     sync.Mutex

-	buf    []byte

-	suffix []byte // remove from each Write

-

-	findTxt   []byte   // search buffer on each Write

-	findCh    chan int // report find position

-	findAfter *time.Timer

+type buf struct {

+	mu  sync.Mutex

+	buf []byte

 }

-func (w *bufWriter) Write(in []byte) (n int, err error) {

+func (w *buf) Write(in []byte) (n int, err error) {

 	w.mu.Lock()

 	defer w.mu.Unlock()

-

-	n = len(in)

-	in = bytes.TrimSuffix(in, w.suffix)

-

-	if debug {

-		inTxt := strings.Replace(string(in), "\n", "\\n", -1)

-		findTxt := strings.Replace(string(w.findTxt), "\n", "\\n", -1)

-		fmt.Printf("debug --> %s <-- debug (findTxt='%s')\n", inTxt, findTxt)

-	}

-

 	w.buf = append(w.buf, in...)

-

-	if len(w.findTxt) > 0 {

-		if i := bytes.Index(w.buf, w.findTxt); i >= 0 {

-			w.findCh <- i

-			close(w.findCh)

-			w.findTxt = nil

-			w.findCh = nil

-			if w.findAfter != nil {

-				w.findAfter.Stop()

-				w.findAfter = nil

-			}

-		}

-	}

-	return n, nil

+	return len(in), nil

 }

-func (w *bufWriter) trimSuffix(p string) {

+func (w *buf) LastIndex(sep []byte) int {

 	w.mu.Lock()

 	defer w.mu.Unlock()

-	w.suffix = []byte(p)

+	return bytes.LastIndex(w.buf, sep)

 }

-func (w *bufWriter) printBuf() {

+func (w *buf) Bytes() []byte {

 	w.mu.Lock()

 	defer w.mu.Unlock()

-	fmt.Fprintf(os.Stderr, "%s", w.buf)

-	w.buf = nil

-}

-func (w *bufWriter) clearTo(i int) {

-	w.mu.Lock()

-	defer w.mu.Unlock()

-	w.buf = w.buf[i:]

+	b := make([]byte, len(w.buf))

+	copy(b, w.buf)

+	return b

 }

-// find returns a channel that will have exactly one byte index sent

-// to it when the text str appears in the buffer. If the text does not

-// appear before timeout, -1 is sent.

-//

-// A timeout of zero means no timeout.

-func (w *bufWriter) find(str string, timeout time.Duration) <-chan int {

+func (w *buf) Len() int {

 	w.mu.Lock()

 	defer w.mu.Unlock()

-	if len(w.findTxt) > 0 {

-		panic(fmt.Sprintf("find(%s): already trying to find %s", str, w.findTxt))

-	}

-	txt := []byte(str)

-	ch := make(chan int, 1)

-	if i := bytes.Index(w.buf, txt); i >= 0 {

-		ch <- i

-		close(ch)

-	} else {

-		w.findTxt = txt

-		w.findCh = ch

-		if timeout > 0 {

-			w.findAfter = time.AfterFunc(timeout, func() {

-				w.mu.Lock()

-				defer w.mu.Unlock()

-				if w.findCh == ch {

-					w.findTxt = nil

-					w.findCh = nil

-					w.findAfter = nil

-					ch <- -1

-					close(ch)

-				}

-			})

-		}

-	}

-	return ch

+	return len(w.buf)

 }

-func (w *bufWriter) isPass() bool {

-	w.mu.Lock()

-	defer w.mu.Unlock()

-

-	// The final stdio of lldb is non-deterministic, so we

-	// scan the whole buffer.

-	//

-	// Just to make things fun, lldb sometimes translates \n

-	// into \r\n.

-	return bytes.Contains(w.buf, []byte("\nPASS\n")) || bytes.Contains(w.buf, []byte("\nPASS\r"))

+type waitPanic struct {

+	err error

 }

 type options struct {

-- 

2.6.1