"testing/iotest"
	"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])

	if err != nil || numEntries < 0 || int(2*numEntries) < int(numEntries) {
		return nil, ErrHeader
	}

	// There should be two numbers in sparseMap for each entry.
	sparseMap := strings.Split(paxHdrs[paxGNUSparseMap], ",")
	if len(sparseMap) == 1 && sparseMap[0] == "" {
		sparseMap = sparseMap[:0]
	}
	if int64(len(sparseMap)) != 2*numEntries {
		return nil, ErrHeader
	}

	parser := NewParser(ctxt, architecture, lexer)
	pList := new(obj.Plist)
	var ok bool
	testOut = new(strings.Builder) // The assembler writes test output to this buffer.
	ctxt.Bso = bufio.NewWriter(os.Stdout)
	ctxt.IsAsm = true
	defer ctxt.Bso.Flush()
	failed := false
	ctxt.DiagFunc = func(format string, args ...interface{}) {
		failed = true
		t.Errorf(format, args...)
	}
	pList.Firstpc, ok = parser.Parse()
	if !ok || failed {

		log.Printf("%s: empty file", filename)
		exitCode = 1
	} else if s[len(s)-1] != '\n' {
		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 {