// See https://golang.org/issue/23469.
	output, err := exec.Command(swig, "-go", "-swiglib").Output()
	if err != nil {
		t.Skip("swig is missing Go support")
	}
	swigDir := strings.TrimSpace(string(output))

	_, err = os.Stat(filepath.Join(swigDir, "go"))
	if err != nil {
		t.Skip("swig is missing Go support")
	}

	// Check that swig has a new enough version.

	if err != nil {
		if ee, ok := err.(*exec.ExitError); ok && len(ee.Stderr) > 0 {
			return errorf("%v: %s", cmd, ee.Stderr)
		}
		return errorf("%v: %w", cmd, err)
	}

	parts := strings.SplitN(string(bytes.TrimSpace(out)), ":", 4)
	if len(parts) < 2 {
		return errorf("%v: missing ':' in output: %q", cmd, out)
	}
	importPath = parts[0]
	if importPath == "" || importPath == "." {

	if !ok {
		return
	}

	if n.Doc == nil {
		return
	}
	for _, c := range n.Doc.List {
		if !strings.HasPrefix(c.Text, "//export ") {
			continue
		}

		name := strings.TrimSpace(c.Text[9:])
		if name == "" {
			error_(c.Pos(), "export missing name")
		}

		if name != n.Name.Name {
			error_(c.Pos(), "export comment has wrong name %q, want %q", name, n.Name.Name)
		}

			//    "... : bad file descriptor.
			continue
		}
		lines := strings.Split(string(d), "\n")
		for _, line := range lines {
			// Different kernel vintages pad differently.
			line = strings.TrimSpace(line)
			if strings.HasPrefix(line, "Pid:\t") {
				// On loaded systems, it is possible
				// for a TID to be reused really
				// quickly. As such, we need to
				// validate that the thread status

			i := strings.Index(c.Text, "+godefs map")
			if i < 0 {
				continue
			}
			s := strings.TrimSpace(c.Text[i+len("+godefs map"):])
			i = strings.Index(s, " ")
			if i < 0 {
				fmt.Fprintf(os.Stderr, "invalid +godefs map comment: %s\n", c.Text)
				continue
			}
			override["_Ctype_"+strings.TrimSpace(s[:i])] = strings.TrimSpace(s[i:])
		}
	}
	for _, n := range f.Name {
		if s := override[n.Go]; s != "" {

		case 1:
			// no comment
		case 2:
			// might be printed form or hex
			note := strings.TrimSpace(parts[1])
			if isHexes(note) {
				hexes = note
			} else {
				printed = note
			}
		case 3:
			// printed form, then hex
			printed = strings.TrimSpace(parts[1])
			hexes = strings.TrimSpace(parts[2])
			if !isHexes(hexes) {
				t.Errorf("%s:%d: malformed hex instruction encoding: %s", input, lineno, line)

}

func plistExtract(fname string, path string) ([]byte, error) {
	out, err := exec.Command("/usr/libexec/PlistBuddy", "-c", "Print "+path, fname).CombinedOutput()
	if err != nil {
		return nil, err
	}
	return bytes.TrimSpace(out), nil
}

func getLines(cmd *exec.Cmd) [][]byte {
	out := output(cmd)
	lines := bytes.Split(out, []byte("\n"))
	// Skip the empty line at the end.
	if len(lines[len(lines)-1]) == 0 {

			continue
		}

		line = strings.TrimSpace(line[8:])

		var key, val string
		spaceIndex := strings.Index(line, " ")
		tabIndex := strings.Index(line, "\t")

		if spaceIndex == -1 && tabIndex == -1 {
			continue
		} else if tabIndex == -1 || (spaceIndex != -1 && spaceIndex < tabIndex) {
			key = line[0:spaceIndex]
			val = strings.TrimSpace(line[spaceIndex:])
		} else {
			key = line[0:tabIndex]

		log.Printf("%s: missing final newline", filename)
		exitCode = 1
	}
	s = aliasReplacer.Replace(s)
	lines := strings.Split(s, "\n")
	var nonblank []string
	for i, line := range lines {
		line = strings.TrimSpace(line)
		if line == "" || strings.HasPrefix(line, "#") {
			continue
		}
		if needApproval {
			feature, approval, ok := strings.Cut(line, "#")
			if !ok {

	"time"
)

func bytediff(a, b []byte) string {
	const (
		uniqueA  = "-  "
		uniqueB  = "+  "
		identity = "   "
	)
	var ss []string
	sa := strings.Split(strings.TrimSpace(hex.Dump(a)), "\n")
	sb := strings.Split(strings.TrimSpace(hex.Dump(b)), "\n")
	for len(sa) > 0 && len(sb) > 0 {
		if sa[0] == sb[0] {
			ss = append(ss, identity+sa[0])
		} else {
			ss = append(ss, uniqueA+sa[0])