misc/ios/go_darwin_arm_exec.go - go - Git at Google

 // Copyright 2015 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.

 // This program can be used as go_darwin_arm_exec by the Go tool.
 // It executes binaries on an iOS device using the XCode toolchain
 // and the ios-deploy program: https://github.com/phonegap/ios-deploy
 //
 // This script supports an extra flag, -lldb, that pauses execution
 // just before the main program begins and allows the user to control
 // the remote lldb session. This flag is appended to the end of the
 // script's arguments and is not passed through to the underlying
 // binary.
 //
 // This script requires that three environment variables be set:
 // 	GOIOS_DEV_ID: The codesigning developer id or certificate identifier
 // 	GOIOS_APP_ID: The provisioning app id prefix. Must support wildcard app ids.
 // 	GOIOS_TEAM_ID: The team id that owns the app id prefix.
 // $GOROOT/misc/ios contains a script, detect.go, that attempts to autodetect these.
 package main

 import (
 	"bytes"
 	"errors"
 	"flag"
 	"fmt"
 	"go/build"
 	"io"
 	"io/ioutil"
 	"log"
 	"os"
 	"os/exec"
 	"path/filepath"
 	"runtime"
 	"strings"
 	"sync"
 	"syscall"
 	"time"
 )

 const debug = false

 var errRetry = errors.New("failed to start test harness (retry attempted)")

 var tmpdir string

 var (
 	devID    string
 	appID    string
 	teamID   string
 	bundleID string
 )

 // lock is a file lock to serialize iOS runs. It is global to avoid the
 // garbage collector finalizing it, closing the file and releasing the
 // lock prematurely.
 var lock *os.File

 func main() {
 	log.SetFlags(0)
 	log.SetPrefix("go_darwin_arm_exec: ")
 	if debug {
 		log.Println(strings.Join(os.Args, " "))
 	}
 	if len(os.Args) < 2 {
 		log.Fatal("usage: go_darwin_arm_exec a.out")
 	}

 	// e.g. B393DDEB490947F5A463FD074299B6C0AXXXXXXX
 	devID = getenv("GOIOS_DEV_ID")

 	// e.g. Z8B3JBXXXX.org.golang.sample, Z8B3JBXXXX prefix is available at
 	// https://developer.apple.com/membercenter/index.action#accountSummary as Team ID.
 	appID = getenv("GOIOS_APP_ID")

 	// e.g. Z8B3JBXXXX, available at
 	// https://developer.apple.com/membercenter/index.action#accountSummary as Team ID.
 	teamID = getenv("GOIOS_TEAM_ID")

 	parts := strings.SplitN(appID, ".", 2)
 	// For compatibility with the old builders, use a fallback bundle ID
 	bundleID = "golang.gotest"
 	if len(parts) == 2 {
 		bundleID = parts[1]
 	}

 	var err error
 	tmpdir, err = ioutil.TempDir("", "go_darwin_arm_exec_")
 	if err != nil {
 		log.Fatal(err)
 	}

 	// This wrapper uses complicated machinery to run iOS binaries. It
 	// works, but only when running one binary at a time.
 	// Use a file lock to make sure only one wrapper is running at a time.
 	//
 	// The lock file is never deleted, to avoid concurrent locks on distinct
 	// files with the same path.
 	lockName := filepath.Join(os.TempDir(), "go_darwin_arm_exec.lock")
 	lock, err = os.OpenFile(lockName, os.O_CREATE|os.O_RDONLY, 0666)
 	if err != nil {
 		log.Fatal(err)
 	}
 	if err := syscall.Flock(int(lock.Fd()), syscall.LOCK_EX); err != nil {
 		log.Fatal(err)
 	}
 	// Approximately 1 in a 100 binaries fail to start. If it happens,
 	// try again. These failures happen for several reasons beyond
 	// our control, but all of them are safe to retry as they happen
 	// before lldb encounters the initial getwd breakpoint. As we
 	// know the tests haven't started, we are not hiding flaky tests
 	// with this retry.
 	for i := 0; i < 5; i++ {
 		if i > 0 {
 			fmt.Fprintln(os.Stderr, "start timeout, trying again")
 		}
 		err = run(os.Args[1], os.Args[2:])
 		if err == nil || err != errRetry {
 			break
 		}
 	}
 	if !debug {
 		os.RemoveAll(tmpdir)
 	}
 	if err != nil {
 		fmt.Fprintf(os.Stderr, "go_darwin_arm_exec: %v\n", err)
 		os.Exit(1)
 	}
 }

 func getenv(envvar string) string {
 	s := os.Getenv(envvar)
 	if s == "" {
 		log.Fatalf("%s not set\nrun $GOROOT/misc/ios/detect.go to attempt to autodetect", envvar)
 	}
 	return s
 }

 func run(bin string, args []string) (err error) {
 	appdir := filepath.Join(tmpdir, "gotest.app")
 	os.RemoveAll(appdir)
 	if err := os.MkdirAll(appdir, 0755); err != nil {
 		return err
 	}

 	if err := cp(filepath.Join(appdir, "gotest"), bin); err != nil {
 		return err
 	}

 	pkgpath, err := copyLocalData(appdir)
 	if err != nil {
 		return err
 	}

 	entitlementsPath := filepath.Join(tmpdir, "Entitlements.plist")
 	if err := ioutil.WriteFile(entitlementsPath, []byte(entitlementsPlist()), 0744); err != nil {
 		return err
 	}
 	if err := ioutil.WriteFile(filepath.Join(appdir, "Info.plist"), []byte(infoPlist(pkgpath)), 0744); err != nil {
 		return err
 	}
 	if err := ioutil.WriteFile(filepath.Join(appdir, "ResourceRules.plist"), []byte(resourceRules), 0744); err != nil {
 		return err
 	}

 	cmd := exec.Command(
 		"codesign",
 		"-f",
 		"-s", devID,
 		"--entitlements", entitlementsPath,
 		appdir,
 	)
 	if debug {
 		log.Println(strings.Join(cmd.Args, " "))
 	}
 	cmd.Stdout = os.Stdout
 	cmd.Stderr = os.Stderr
 	if err := cmd.Run(); err != nil {
 		return fmt.Errorf("codesign: %v", err)
 	}

 	oldwd, err := os.Getwd()
 	if err != nil {
 		return err
 	}
 	if err := os.Chdir(filepath.Join(appdir, "..")); err != nil {
 		return err
 	}
 	defer os.Chdir(oldwd)

 	// Setting up lldb is flaky. The test binary itself runs when
 	// started is set to true. Everything before that is considered
 	// part of the setup and is retried.
 	started := false
 	defer func() {
 		if r := recover(); r != nil {
 			if w, ok := r.(waitPanic); ok {
 				err = w.err
 				if !started {
 					fmt.Printf("lldb setup error: %v\n", err)
 					err = errRetry
 				}
 				return
 			}
 			panic(r)
 		}
 	}()

 	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.
 	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 SIGCONT --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
 	}

 	started = true

 	s.doCmd("run", "stop reason = signal SIGINT", 20*time.Second)

 	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 ||
 			s.out.LastIndex([]byte("exited with status = 0 (0x00000000) \n")) > startTestsLen ||
 			s.out.LastIndex([]byte("exited with status = 0 (0x00000000) \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),
 	}

 	iosdPath, err := exec.LookPath("ios-deploy")
 	if err != nil {
 		return nil, err
 	}
 	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.
 		"script",
 		"-q", "-t", "0",
 		"/dev/null",

 		iosdPath,
 		"--debug",
 		"-u",
 		"-r",
 		"-n",
 		`--args=`+strings.Join(args, " ")+``,
 		"--bundle", appdir,
 	)
 	if debug {
 		log.Println(strings.Join(s.cmd.Args, " "))
 	}

 	var out io.Writer = s.out
 	if opts.lldb {
 		out = io.MultiWriter(out, os.Stderr)
 	}
 	s.cmd.Stdout = out
 	s.cmd.Stderr = out // everything of interest is on stderr
 	s.cmd.Stdin = lldbr

 	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.
 	if opts.timeout > 1*time.Second {
 		s.timedout = make(chan struct{})
 		time.AfterFunc(opts.timeout-1*time.Second, func() {
 			close(s.timedout)
 		})
 	}

 	go func() {
 		s.exited <- s.cmd.Wait()
 	}()

 	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
 	}
 	if err := s.wait("lldb start", cond, 10*time.Second); err != nil {
 		panic(waitPanic{err})
 	}
 	return s, nil
 }

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

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

 func (s *lldbSession) wait(reason string, cond func(out *buf) bool, extraTimeout time.Duration) error {
 	doTimeout := 2*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)
 		}
 	}
 }

 type buf struct {
 	mu  sync.Mutex
 	buf []byte
 }

 func (w *buf) Write(in []byte) (n int, err error) {
 	w.mu.Lock()
 	defer w.mu.Unlock()
 	w.buf = append(w.buf, in...)
 	return len(in), nil
 }

 func (w *buf) LastIndex(sep []byte) int {
 	w.mu.Lock()
 	defer w.mu.Unlock()
 	return bytes.LastIndex(w.buf, sep)
 }

 func (w *buf) Bytes() []byte {
 	w.mu.Lock()
 	defer w.mu.Unlock()

 	b := make([]byte, len(w.buf))
 	copy(b, w.buf)
 	return b
 }

 func (w *buf) Len() int {
 	w.mu.Lock()
 	defer w.mu.Unlock()
 	return len(w.buf)
 }

 type waitPanic struct {
 	err error
 }

 type options struct {
 	timeout time.Duration
 	lldb    bool
 }

 func parseArgs(binArgs []string) (opts options, remainingArgs []string) {
 	var flagArgs []string
 	for _, arg := range binArgs {
 		if strings.Contains(arg, "-test.timeout") {
 			flagArgs = append(flagArgs, arg)
 		}
 		if strings.Contains(arg, "-lldb") {
 			flagArgs = append(flagArgs, arg)
 			continue
 		}
 		remainingArgs = append(remainingArgs, arg)
 	}
 	f := flag.NewFlagSet("", flag.ContinueOnError)
 	f.DurationVar(&opts.timeout, "test.timeout", 10*time.Minute, "")
 	f.BoolVar(&opts.lldb, "lldb", false, "")
 	f.Parse(flagArgs)
 	return opts, remainingArgs

 }

 func copyLocalDir(dst, src string) error {
 	if err := os.Mkdir(dst, 0755); err != nil {
 		return err
 	}

 	d, err := os.Open(src)
 	if err != nil {
 		return err
 	}
 	defer d.Close()
 	fi, err := d.Readdir(-1)
 	if err != nil {
 		return err
 	}

 	for _, f := range fi {
 		if f.IsDir() {
 			if f.Name() == "testdata" {
 				if err := cp(dst, filepath.Join(src, f.Name())); err != nil {
 					return err
 				}
 			}
 			continue
 		}
 		if err := cp(dst, filepath.Join(src, f.Name())); err != nil {
 			return err
 		}
 	}
 	return nil
 }

 func cp(dst, src string) error {
 	out, err := exec.Command("cp", "-a", src, dst).CombinedOutput()
 	if err != nil {
 		os.Stderr.Write(out)
 	}
 	return err
 }

 func copyLocalData(dstbase string) (pkgpath string, err error) {
 	cwd, err := os.Getwd()
 	if err != nil {
 		return "", err
 	}

 	finalPkgpath, underGoRoot, err := subdir()
 	if err != nil {
 		return "", err
 	}
 	cwd = strings.TrimSuffix(cwd, finalPkgpath)

 	// Copy all immediate files and testdata directories between
 	// the package being tested and the source root.
 	pkgpath = ""
 	for _, element := range strings.Split(finalPkgpath, string(filepath.Separator)) {
 		if debug {
 			log.Printf("copying %s", pkgpath)
 		}
 		pkgpath = filepath.Join(pkgpath, element)
 		dst := filepath.Join(dstbase, pkgpath)
 		src := filepath.Join(cwd, pkgpath)
 		if err := copyLocalDir(dst, src); err != nil {
 			return "", err
 		}
 	}

 	// Copy timezone file.
 	//
 	// Typical apps have the zoneinfo.zip in the root of their app bundle,
 	// read by the time package as the working directory at initialization.
 	// As we move the working directory to the GOROOT pkg directory, we
 	// install the zoneinfo.zip file in the pkgpath.
 	if underGoRoot {
 		err := cp(
 			filepath.Join(dstbase, pkgpath),
 			filepath.Join(cwd, "lib", "time", "zoneinfo.zip"),
 		)
 		if err != nil {
 			return "", err
 		}
 	}

 	return finalPkgpath, nil
 }

 // subdir determines the package based on the current working directory,
 // and returns the path to the package source relative to $GOROOT (or $GOPATH).
 func subdir() (pkgpath string, underGoRoot bool, err error) {
 	cwd, err := os.Getwd()
 	if err != nil {
 		return "", false, err
 	}
 	if root := runtime.GOROOT(); strings.HasPrefix(cwd, root) {
 		subdir, err := filepath.Rel(root, cwd)
 		if err != nil {
 			return "", false, err
 		}
 		return subdir, true, nil
 	}

 	for _, p := range filepath.SplitList(build.Default.GOPATH) {
 		if !strings.HasPrefix(cwd, p) {
 			continue
 		}
 		subdir, err := filepath.Rel(p, cwd)
 		if err == nil {
 			return subdir, false, nil
 		}
 	}
 	return "", false, fmt.Errorf(
 		"working directory %q is not in either GOROOT(%q) or GOPATH(%q)",
 		cwd,
 		runtime.GOROOT(),
 		build.Default.GOPATH,
 	)
 }

 func infoPlist(pkgpath string) string {
 	return `<?xml version="1.0" encoding="UTF-8"?>
 <!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
 <plist version="1.0">
 <dict>
 <key>CFBundleName</key><string>golang.gotest</string>
 <key>CFBundleSupportedPlatforms</key><array><string>iPhoneOS</string></array>
 <key>CFBundleExecutable</key><string>gotest</string>
 <key>CFBundleVersion</key><string>1.0</string>
 <key>CFBundleIdentifier</key><string>` + bundleID + `</string>
 <key>CFBundleResourceSpecification</key><string>ResourceRules.plist</string>
 <key>LSRequiresIPhoneOS</key><true/>
 <key>CFBundleDisplayName</key><string>gotest</string>
 <key>GoExecWrapperWorkingDirectory</key><string>` + pkgpath + `</string>
 </dict>
 </plist>
 `
 }

 func entitlementsPlist() string {
 	return `<?xml version="1.0" encoding="UTF-8"?>
 <!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
 <plist version="1.0">
 <dict>
 	<key>keychain-access-groups</key>
 	<array><string>` + appID + `</string></array>
 	<key>get-task-allow</key>
 	<true/>
 	<key>application-identifier</key>
 	<string>` + appID + `</string>
 	<key>com.apple.developer.team-identifier</key>
 	<string>` + teamID + `</string>
 </dict>
 </plist>
 `
 }

 const resourceRules = `<?xml version="1.0" encoding="UTF-8"?>
 <!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
 <plist version="1.0">
 <dict>
 	<key>rules</key>
 	<dict>
 		<key>.*</key>
 		<true/>
 		<key>Info.plist</key>
 		<dict>
 			<key>omit</key>
 			<true/>
 			<key>weight</key>
 			<integer>10</integer>
 		</dict>
 		<key>ResourceRules.plist</key>
 		<dict>
 			<key>omit</key>
 			<true/>
 			<key>weight</key>
 			<integer>100</integer>
 		</dict>
 	</dict>
 </dict>
 </plist>
 `
	// Copyright 2015 The Go Authors. All rights reserved.
	// Use of this source code is governed by a BSD-style
	// license that can be found in the LICENSE file.

	// This program can be used as go_darwin_arm_exec by the Go tool.
	// It executes binaries on an iOS device using the XCode toolchain
	// and the ios-deploy program: https://github.com/phonegap/ios-deploy
	//
	// This script supports an extra flag, -lldb, that pauses execution
	// just before the main program begins and allows the user to control
	// the remote lldb session. This flag is appended to the end of the
	// script's arguments and is not passed through to the underlying
	// binary.
	//
	// This script requires that three environment variables be set:
	// GOIOS_DEV_ID: The codesigning developer id or certificate identifier
	// GOIOS_APP_ID: The provisioning app id prefix. Must support wildcard app ids.
	// GOIOS_TEAM_ID: The team id that owns the app id prefix.
	// $GOROOT/misc/ios contains a script, detect.go, that attempts to autodetect these.
	package main

	import (
	"bytes"
	"errors"
	"flag"
	"fmt"
	"go/build"
	"io"
	"io/ioutil"
	"log"
	"os"
	"os/exec"
	"path/filepath"
	"runtime"
	"strings"
	"sync"
	"syscall"
	"time"
	)

	const debug = false

	var errRetry = errors.New("failed to start test harness (retry attempted)")

	var tmpdir string

	var (
	devID string
	appID string
	teamID string
	bundleID string
	)

	// lock is a file lock to serialize iOS runs. It is global to avoid the
	// garbage collector finalizing it, closing the file and releasing the
	// lock prematurely.
	var lock *os.File

	func main() {
	log.SetFlags(0)
	log.SetPrefix("go_darwin_arm_exec: ")
	if debug {
	log.Println(strings.Join(os.Args, " "))
	}
	if len(os.Args) < 2 {
	log.Fatal("usage: go_darwin_arm_exec a.out")
	}

	// e.g. B393DDEB490947F5A463FD074299B6C0AXXXXXXX
	devID = getenv("GOIOS_DEV_ID")

	// e.g. Z8B3JBXXXX.org.golang.sample, Z8B3JBXXXX prefix is available at
	// https://developer.apple.com/membercenter/index.action#accountSummary as Team ID.
	appID = getenv("GOIOS_APP_ID")

	// e.g. Z8B3JBXXXX, available at
	// https://developer.apple.com/membercenter/index.action#accountSummary as Team ID.
	teamID = getenv("GOIOS_TEAM_ID")

	parts := strings.SplitN(appID, ".", 2)
	// For compatibility with the old builders, use a fallback bundle ID
	bundleID = "golang.gotest"
	if len(parts) == 2 {
	bundleID = parts[1]
	}

	var err error
	tmpdir, err = ioutil.TempDir("", "go_darwin_arm_exec_")
	if err != nil {
	log.Fatal(err)
	}

	// This wrapper uses complicated machinery to run iOS binaries. It
	// works, but only when running one binary at a time.
	// Use a file lock to make sure only one wrapper is running at a time.
	//
	// The lock file is never deleted, to avoid concurrent locks on distinct
	// files with the same path.
	lockName := filepath.Join(os.TempDir(), "go_darwin_arm_exec.lock")
	lock, err = os.OpenFile(lockName, os.O_CREATE\|os.O_RDONLY, 0666)
	if err != nil {
	log.Fatal(err)
	}
	if err := syscall.Flock(int(lock.Fd()), syscall.LOCK_EX); err != nil {
	log.Fatal(err)
	}
	// Approximately 1 in a 100 binaries fail to start. If it happens,
	// try again. These failures happen for several reasons beyond
	// our control, but all of them are safe to retry as they happen
	// before lldb encounters the initial getwd breakpoint. As we
	// know the tests haven't started, we are not hiding flaky tests
	// with this retry.
	for i := 0; i < 5; i++ {
	if i > 0 {
	fmt.Fprintln(os.Stderr, "start timeout, trying again")
	}
	err = run(os.Args[1], os.Args[2:])
	if err == nil \|\| err != errRetry {
	break
	}
	}
	if !debug {
	os.RemoveAll(tmpdir)
	}
	if err != nil {
	fmt.Fprintf(os.Stderr, "go_darwin_arm_exec: %v\n", err)
	os.Exit(1)
	}
	}

	func getenv(envvar string) string {
	s := os.Getenv(envvar)
	if s == "" {
	log.Fatalf("%s not set\nrun $GOROOT/misc/ios/detect.go to attempt to autodetect", envvar)
	}
	return s
	}

	func run(bin string, args []string) (err error) {
	appdir := filepath.Join(tmpdir, "gotest.app")
	os.RemoveAll(appdir)
	if err := os.MkdirAll(appdir, 0755); err != nil {
	return err
	}

	if err := cp(filepath.Join(appdir, "gotest"), bin); err != nil {
	return err
	}

	pkgpath, err := copyLocalData(appdir)
	if err != nil {
	return err
	}

	entitlementsPath := filepath.Join(tmpdir, "Entitlements.plist")
	if err := ioutil.WriteFile(entitlementsPath, []byte(entitlementsPlist()), 0744); err != nil {
	return err
	}
	if err := ioutil.WriteFile(filepath.Join(appdir, "Info.plist"), []byte(infoPlist(pkgpath)), 0744); err != nil {
	return err
	}
	if err := ioutil.WriteFile(filepath.Join(appdir, "ResourceRules.plist"), []byte(resourceRules), 0744); err != nil {
	return err
	}

	cmd := exec.Command(
	"codesign",
	"-f",
	"-s", devID,
	"--entitlements", entitlementsPath,
	appdir,
	)
	if debug {
	log.Println(strings.Join(cmd.Args, " "))
	}
	cmd.Stdout = os.Stdout
	cmd.Stderr = os.Stderr
	if err := cmd.Run(); err != nil {
	return fmt.Errorf("codesign: %v", err)
	}

	oldwd, err := os.Getwd()
	if err != nil {
	return err
	}
	if err := os.Chdir(filepath.Join(appdir, "..")); err != nil {
	return err
	}
	defer os.Chdir(oldwd)

	// Setting up lldb is flaky. The test binary itself runs when
	// started is set to true. Everything before that is considered
	// part of the setup and is retried.
	started := false
	defer func() {
	if r := recover(); r != nil {
	if w, ok := r.(waitPanic); ok {
	err = w.err
	if !started {
	fmt.Printf("lldb setup error: %v\n", err)
	err = errRetry
	}
	return
	}
	panic(r)
	}
	}()

	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.
	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 SIGCONT --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
	}

	started = true

	s.doCmd("run", "stop reason = signal SIGINT", 20*time.Second)

	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 \|\|
	s.out.LastIndex([]byte("exited with status = 0 (0x00000000) \n")) > startTestsLen \|\|
	s.out.LastIndex([]byte("exited with status = 0 (0x00000000) \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),
	}

	iosdPath, err := exec.LookPath("ios-deploy")
	if err != nil {
	return nil, err
	}
	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.
	"script",
	"-q", "-t", "0",
	"/dev/null",

	iosdPath,
	"--debug",
	"-u",
	"-r",
	"-n",
	`--args=`+strings.Join(args, " ")+``,
	"--bundle", appdir,
	)
	if debug {
	log.Println(strings.Join(s.cmd.Args, " "))
	}

	var out io.Writer = s.out
	if opts.lldb {
	out = io.MultiWriter(out, os.Stderr)
	}
	s.cmd.Stdout = out
	s.cmd.Stderr = out // everything of interest is on stderr
	s.cmd.Stdin = lldbr

	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.
	if opts.timeout > 1*time.Second {
	s.timedout = make(chan struct{})
	time.AfterFunc(opts.timeout-1*time.Second, func() {
	close(s.timedout)
	})
	}

	go func() {
	s.exited <- s.cmd.Wait()
	}()

	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
	}
	if err := s.wait("lldb start", cond, 10*time.Second); err != nil {
	panic(waitPanic{err})
	}
	return s, nil
	}

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

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

	func (s lldbSession) wait(reason string, cond func(out buf) bool, extraTimeout time.Duration) error {
	doTimeout := 2*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)
	}
	}
	}

	type buf struct {
	mu sync.Mutex
	buf []byte
	}

	func (w *buf) Write(in []byte) (n int, err error) {
	w.mu.Lock()
	defer w.mu.Unlock()
	w.buf = append(w.buf, in...)
	return len(in), nil
	}

	func (w *buf) LastIndex(sep []byte) int {
	w.mu.Lock()
	defer w.mu.Unlock()
	return bytes.LastIndex(w.buf, sep)
	}

	func (w *buf) Bytes() []byte {
	w.mu.Lock()
	defer w.mu.Unlock()

	b := make([]byte, len(w.buf))
	copy(b, w.buf)
	return b
	}

	func (w *buf) Len() int {
	w.mu.Lock()
	defer w.mu.Unlock()
	return len(w.buf)
	}

	type waitPanic struct {
	err error
	}

	type options struct {
	timeout time.Duration
	lldb bool
	}

	func parseArgs(binArgs []string) (opts options, remainingArgs []string) {
	var flagArgs []string
	for _, arg := range binArgs {
	if strings.Contains(arg, "-test.timeout") {
	flagArgs = append(flagArgs, arg)
	}
	if strings.Contains(arg, "-lldb") {
	flagArgs = append(flagArgs, arg)
	continue
	}
	remainingArgs = append(remainingArgs, arg)
	}
	f := flag.NewFlagSet("", flag.ContinueOnError)
	f.DurationVar(&opts.timeout, "test.timeout", 10*time.Minute, "")
	f.BoolVar(&opts.lldb, "lldb", false, "")
	f.Parse(flagArgs)
	return opts, remainingArgs

	}

	func copyLocalDir(dst, src string) error {
	if err := os.Mkdir(dst, 0755); err != nil {
	return err
	}

	d, err := os.Open(src)
	if err != nil {
	return err
	}
	defer d.Close()
	fi, err := d.Readdir(-1)
	if err != nil {
	return err
	}

	for _, f := range fi {
	if f.IsDir() {
	if f.Name() == "testdata" {
	if err := cp(dst, filepath.Join(src, f.Name())); err != nil {
	return err
	}
	}
	continue
	}
	if err := cp(dst, filepath.Join(src, f.Name())); err != nil {
	return err
	}
	}
	return nil
	}

	func cp(dst, src string) error {
	out, err := exec.Command("cp", "-a", src, dst).CombinedOutput()
	if err != nil {
	os.Stderr.Write(out)
	}
	return err
	}

	func copyLocalData(dstbase string) (pkgpath string, err error) {
	cwd, err := os.Getwd()
	if err != nil {
	return "", err
	}

	finalPkgpath, underGoRoot, err := subdir()
	if err != nil {
	return "", err
	}
	cwd = strings.TrimSuffix(cwd, finalPkgpath)

	// Copy all immediate files and testdata directories between
	// the package being tested and the source root.
	pkgpath = ""
	for _, element := range strings.Split(finalPkgpath, string(filepath.Separator)) {
	if debug {
	log.Printf("copying %s", pkgpath)
	}
	pkgpath = filepath.Join(pkgpath, element)
	dst := filepath.Join(dstbase, pkgpath)
	src := filepath.Join(cwd, pkgpath)
	if err := copyLocalDir(dst, src); err != nil {
	return "", err
	}
	}

	// Copy timezone file.
	//
	// Typical apps have the zoneinfo.zip in the root of their app bundle,
	// read by the time package as the working directory at initialization.
	// As we move the working directory to the GOROOT pkg directory, we
	// install the zoneinfo.zip file in the pkgpath.
	if underGoRoot {
	err := cp(
	filepath.Join(dstbase, pkgpath),
	filepath.Join(cwd, "lib", "time", "zoneinfo.zip"),
	)
	if err != nil {
	return "", err
	}
	}

	return finalPkgpath, nil
	}

	// subdir determines the package based on the current working directory,
	// and returns the path to the package source relative to $GOROOT (or $GOPATH).
	func subdir() (pkgpath string, underGoRoot bool, err error) {
	cwd, err := os.Getwd()
	if err != nil {
	return "", false, err
	}
	if root := runtime.GOROOT(); strings.HasPrefix(cwd, root) {
	subdir, err := filepath.Rel(root, cwd)
	if err != nil {
	return "", false, err
	}
	return subdir, true, nil
	}

	for _, p := range filepath.SplitList(build.Default.GOPATH) {
	if !strings.HasPrefix(cwd, p) {
	continue
	}
	subdir, err := filepath.Rel(p, cwd)
	if err == nil {
	return subdir, false, nil
	}
	}
	return "", false, fmt.Errorf(
	"working directory %q is not in either GOROOT(%q) or GOPATH(%q)",
	cwd,
	runtime.GOROOT(),
	build.Default.GOPATH,
	)
	}

	func infoPlist(pkgpath string) string {
	return `<?xml version="1.0" encoding="UTF-8"?>
	<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
	<plist version="1.0">
	<dict>
	<key>CFBundleName</key><string>golang.gotest</string>
	<key>CFBundleSupportedPlatforms</key><array><string>iPhoneOS</string></array>
	<key>CFBundleExecutable</key><string>gotest</string>
	<key>CFBundleVersion</key><string>1.0</string>
	<key>CFBundleIdentifier</key><string>` + bundleID + `</string>
	<key>CFBundleResourceSpecification</key><string>ResourceRules.plist</string>
	<key>LSRequiresIPhoneOS</key><true/>
	<key>CFBundleDisplayName</key><string>gotest</string>
	<key>GoExecWrapperWorkingDirectory</key><string>` + pkgpath + `</string>
	</dict>
	</plist>
	`
	}

	func entitlementsPlist() string {
	return `<?xml version="1.0" encoding="UTF-8"?>
	<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
	<plist version="1.0">
	<dict>
	<key>keychain-access-groups</key>
	<array><string>` + appID + `</string></array>
	<key>get-task-allow</key>
	<true/>
	<key>application-identifier</key>
	<string>` + appID + `</string>
	<key>com.apple.developer.team-identifier</key>
	<string>` + teamID + `</string>
	</dict>
	</plist>
	`
	}

	const resourceRules = `<?xml version="1.0" encoding="UTF-8"?>
	<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
	<plist version="1.0">
	<dict>
	<key>rules</key>
	<dict>
	<key>.*</key>
	<true/>
	<key>Info.plist</key>
	<dict>
	<key>omit</key>
	<true/>
	<key>weight</key>
	<integer>10</integer>
	</dict>
	<key>ResourceRules.plist</key>
	<dict>
	<key>omit</key>
	<true/>
	<key>weight</key>
	<integer>100</integer>
	</dict>
	</dict>
	</dict>
	</plist>
	`