// If we were unable to read anything out of the archive don't
		// bother trying to roundtrip it.
		if len(files) == 0 {
			return
		}

		out := bytes.NewBuffer(nil)
		w := NewWriter(out)
		for _, f := range files {
			if err := w.WriteHeader(f.header); err != nil {
				t.Fatalf("unable to write previously parsed header: %s", err)
			}
			if _, err := w.Write(f.content); err != nil {

	}
}

// predefine installs the macros set by the -D flag on the command line.
func predefine(defines flags.MultiFlag) map[string]*Macro {
	macros := make(map[string]*Macro)
	for _, name := range defines {
		value := "1"
		i := strings.IndexRune(name, '=')
		if i > 0 {
			name, value = name[:i], name[i+1:]
		}
		tokens := Tokenize(name)
		if len(tokens) != 1 || tokens[0].ScanToken != scanner.Ident {

	// We do not do any explicit checks, just ensure that it does not crash.
	for _, f := range splitTests {
		f()
	}
}

//export goStackCheck
func goStackCheck() {
	// use some stack memory to trigger split stack check
	var buf [256]byte
	use(buf[:])
}

var Used byte

func use(buf []byte) {
	for _, c := range buf {
		Used += c
	}
}

var splitTests = []func(){

			panic("bytes: Join output length overflow")
		}
		n += len(sep) * (len(s) - 1)
	}
	for _, v := range s {
		if len(v) > maxInt-n {
			panic("bytes: Join output length overflow")
		}
		n += len(v)
	}

	b := bytealg.MakeNoZero(n)[:n:n]
	bp := copy(b, s[0])
	for _, v := range s[1:] {
		bp += copy(b[bp:], sep)
		bp += copy(b[bp:], v)
	}
	return b
}

		if lastByte := rp.b; len(p) > 0 && p[0] == lastByte {
			if bytes.Count(p, []byte{lastByte}) == len(p) {
				rp.n += int64(len(p))
				return len(p), nil
			}
		}
	}

	for _, b := range p {
		if rp == nil || rp.b != b {
			r.buf = append(r.buf, repeatedByte{r.Size(), b, 1})
			rp = &r.buf[len(r.buf)-1]
		} else {
			rp.n++
		}
	}
	return len(p), nil
}

		{seek: io.SeekStart, n: 5, want: "01234"},
		{seek: io.SeekCurrent, n: 5, want: "56789"},
		{seek: io.SeekEnd, off: -1, n: 1, wantpos: 9, want: "9"},
	}

	for i, tt := range tests {
		pos, err := r.Seek(tt.off, tt.seek)
		if err == nil && tt.seekerr != "" {
			t.Errorf("%d. want seek error %q", i, tt.seekerr)
			continue
		}
		if err != nil && err.Error() != tt.seekerr {

	if len(paxHdrs) > 0 || isGlobal {
		// Sort keys for deterministic ordering.
		var keys []string
		for k := range paxHdrs {
			keys = append(keys, k)
		}
		sort.Strings(keys)

		// Write each record to a buffer.
		var buf strings.Builder
		for _, k := range keys {
			rec, err := formatPAXRecord(k, paxHdrs[k])
			if err != nil {
				return err
			}
			buf.WriteString(rec)
		}

		Name, Body string
	}{
		{"readme.txt", "This archive contains some text files."},
		{"gopher.txt", "Gopher names:\nGeorge\nGeoffrey\nGonzo"},
		{"todo.txt", "Get animal handling license."},
	}
	for _, file := range files {
		hdr := &tar.Header{
			Name: file.Name,
			Mode: 0600,
			Size: int64(len(file.Body)),
		}
		if err := tw.WriteHeader(hdr); err != nil {
			log.Fatal(err)
		}

}

var errorRune = []byte(string(utf8.RuneError))

// ScanRunes is a split function for a [Scanner] that returns each
// UTF-8-encoded rune as a token. The sequence of runes returned is
// equivalent to that from a range loop over the input as a string, which
// means that erroneous UTF-8 encodings translate to U+FFFD = "\xef\xbf\xbd".
// Because of the Scan interface, this makes it impossible for the client to

		{"BSWAPW DX", `unrecognized instruction`},
		{"BSWAPW R11", `unrecognized instruction`},
	})
}

func testBadInstParser(t *testing.T, goarch string, tests []badInstTest) {
	for i, test := range tests {
		arch, ctxt := setArch(goarch)
		tokenizer := lex.NewTokenizer("", strings.NewReader(test.input+"\n"), nil)
		parser := NewParser(ctxt, arch, tokenizer)

		err := tryParse(t, func() {
			parser.Parse()
		})