if err != nil {
				t.Fatal(err)
			}
			for _, feat := range w.Features() {
				fmt.Fprintf(f, "%s\n", feat)
			}
			f.Close()
		}

		bs, err := os.ReadFile(goldenFile)
		if err != nil {
			t.Fatalf("opening golden.txt for package %q: %v", fi.Name(), err)
		}
		wanted := strings.Split(string(bs), "\n")
		sort.Strings(wanted)
		for _, feature := range wanted {
			if feature == "" {
				continue
			}

	"os"
	"path/filepath"
	"testing"
)

func FuzzReader(f *testing.F) {
	testdata, err := os.ReadDir("testdata")
	if err != nil {
		f.Fatalf("failed to read testdata directory: %s", err)
	}
	for _, de := range testdata {
		if de.IsDir() {
			continue
		}
		b, err := os.ReadFile(filepath.Join("testdata", de.Name()))
		if err != nil {
			f.Fatalf("failed to read testdata: %s", err)
		}
		f.Add(b)
	}

	// Note these errors should be independent of the architecture.
	// Just run the test with amd64.
	parser := newParser("amd64")
	var buf strings.Builder
	parser.errorWriter = &buf

	for _, cat := range testcats {
		for _, test := range cat.tests {
			parser.allowABI = cat.allowABI
			parser.errorCount = 0
			parser.lineNum++
			if !parser.pseudo(test.pseudo, tokenize(test.operands)) {

		argv := append(os.Args, "-test.run=^$")
		if err := syscall.Exec(os.Args[0], argv, os.Environ()); err != nil {
			t.Fatal(err)
		}
	}

	var cmds []*exec.Cmd
	defer func() {
		for _, cmd := range cmds {
			cmd.Process.Kill()
		}
	}()

	args := append(append([]string(nil), os.Args[1:]...), "-test.run=^Test18146$")
	for n := attempts; n > 0; n-- {
		cmd := exec.Command(os.Args[0], args...)

	RORIW	$32, X5, X6			// ERROR "immediate out of range 0 to 31"
	SLLIW	$32, X5, X6			// ERROR "immediate out of range 0 to 31"
	SRLIW	$32, X5, X6			// ERROR "immediate out of range 0 to 31"
	SRAIW	$32, X5, X6			// ERROR "immediate out of range 0 to 31"
	RORIW	$-1, X5, X6			// ERROR "immediate out of range 0 to 31"
	SLLIW	$-1, X5, X6			// ERROR "immediate out of range 0 to 31"

func TestEqualNearPageBoundary(t *testing.T) {
	t.Parallel()
	b := dangerousSlice(t)
	for i := range b {
		b[i] = 'A'
	}
	for i := 0; i <= len(b); i++ {
		Equal(b[:i], b[len(b)-i:])
		Equal(b[len(b)-i:], b[:i])
	}
}

func TestIndexByteNearPageBoundary(t *testing.T) {
	t.Parallel()
	b := dangerousSlice(t)
	for i := range b {
		idx := IndexByte(b[i:], 1)
		if idx != -1 {

	fs, err := os.ReadDir(fmt.Sprintf("/proc/%d/task", pid))
	if err != nil {
		return fmt.Errorf("unable to find %d tasks: %v", pid, err)
	}
	expectedProc := fmt.Sprintf("Pid:\t%d", pid)
	foundAThread := false
	for _, f := range fs {
		tf := fmt.Sprintf("/proc/%s/status", f.Name())
		d, err := os.ReadFile(tf)
		if err != nil {
			// There are a surprising number of ways this
			// can error out on linux.  We've seen all of

func isASCII(s string) bool {
	for _, c := range s {
		if c >= 0x80 || c == 0x00 {
			return false
		}
	}
	return true
}

// toASCII converts the input to an ASCII C-style string.
// This is a best effort conversion, so invalid characters are dropped.
func toASCII(s string) string {
	if isASCII(s) {
		return s
	}
	b := make([]byte, 0, len(s))
	for _, c := range s {
		if c < 0x80 && c != 0x00 {

	if err != nil {
		if os.IsNotExist(err) {
			t.Skip("no /proc/self/exe")
		}
		t.Fatal("opening /proc/self/exe: ", err)
	}
	defer f.Close()

	c := 0
sections:
	for i, s := range f.Sections {
		if s.Type != elf.SHT_NOTE {
			continue
		}

		d, err := s.Data()
		if err != nil {
			t.Logf("reading data of note section %d: %v", i, err)
			continue
		}

		for len(d) > 0 {

		// 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 {