if mode == readdirDirEntry {
				dirents = append(dirents, dirEntry{f})
			} else {
				infos = append(infos, f)
			}
		}
		d.bufp += m
		n--
	}

	if n > 0 && len(names)+len(dirents)+len(infos) == 0 {
		return nil, nil, nil, io.EOF
	}
	return names, dirents, infos, nil
}

type dirEntry struct {
	fs *fileStat
}

func (de dirEntry) Name() string            { return de.fs.Name() }

	ReadDir(name string) ([]DirEntry, error)
}

// ReadDir reads the named directory
// and returns a list of directory entries sorted by filename.
//
// If fs implements [ReadDirFS], ReadDir calls fs.ReadDir.
// Otherwise ReadDir calls fs.Open and uses ReadDir and Close
// on the returned file.
func ReadDir(fsys FS, name string) ([]DirEntry, error) {
	if fsys, ok := fsys.(ReadDirFS); ok {

		names = []string{}
	}
	return names, err
}

// A DirEntry is an entry read from a directory
// (using the [ReadDir] function or a [File.ReadDir] method).
type DirEntry = fs.DirEntry

// ReadDir reads the contents of the directory associated with the file f
// and returns a slice of [DirEntry] values in directory order.
// Subsequent calls on the same file will yield later DirEntry records in the directory.
//

				if mode == readdirDirEntry {
					dirents = append(dirents, dirEntry{f})
				} else {
					infos = append(infos, f)
				}
			}
			n--
		}
	}
	if !wantAll && len(names)+len(dirents)+len(infos) == 0 {
		return nil, nil, nil, io.EOF
	}
	return names, dirents, infos, nil
}

type dirEntry struct {
	fs *fileStat
}

func (de dirEntry) Name() string            { return de.fs.Name() }

	return 0, &fs.PathError{Op: "read", Path: d.path, Err: fs.ErrInvalid}
}

func (d *mapDir) ReadDir(count int) ([]fs.DirEntry, error) {
	n := len(d.entry) - d.offset
	if n == 0 && count > 0 {
		return nil, io.EOF
	}
	if count > 0 && n > count {
		n = count
	}
	list := make([]fs.DirEntry, n)
	for i := range list {
		list[i] = &d.entry[d.offset+i]
	}
	d.offset += n
	return list, nil

)

// A file is a single file in the FS.
// It implements fs.FileInfo and fs.DirEntry.
type file struct {
	// The compiler knows the layout of this struct.
	// See cmd/compile/internal/staticdata's WriteEmbed.
	name string
	data string
	hash [16]byte // truncated SHA256 hash
}

var (
	_ fs.FileInfo = (*file)(nil)
	_ fs.DirEntry = (*file)(nil)
)

	f, err := MapFS(fsys).Open(name)
	if err != nil {
		return nil, err
	}
	return &shuffledFile{File: f}, nil
}

type shuffledFile struct{ fs.File }

func (f *shuffledFile) ReadDir(n int) ([]fs.DirEntry, error) {
	dirents, err := f.File.(fs.ReadDirFile).ReadDir(n)
	// Shuffle in a deterministic way, all we care about is making sure that the
	// list of directory entries is not is the lexicographic order.
	//

// The order of the lists need not match.
func (t *fsTester) checkDirList(dir, desc string, list1, list2 []fs.DirEntry) {
	old := make(map[string]fs.DirEntry)
	checkMode := func(entry fs.DirEntry) {
		if entry.IsDir() != (entry.Type()&fs.ModeDir != 0) {
			if entry.IsDir() {
				t.errorf("%s: ReadDir returned %s with IsDir() = true, Type() & ModeDir = 0", dir, entry.Name())

}

func walkDir(path string) {
	filepath.WalkDir(path, visitFile)
}

func visitFile(path string, f fs.DirEntry, err error) error {
	if err == nil && isGoFile(f) {
		err = processFile(path, false)
	}
	if err != nil {
		report(err)
	}
	return nil
}

func isGoFile(f fs.DirEntry) bool {
	// ignore non-Go files
	name := f.Name()

}

func (d *dirInfo) close() {
	if d.dir == 0 {
		return
	}
	closedir(d.dir)
	d.dir = 0
}

func (f *File) readdir(n int, mode readdirMode) (names []string, dirents []DirEntry, infos []FileInfo, err error) {
	// If this file has no dirinfo, create one.
	var d *dirInfo
	for {
		d = f.dirinfo.Load()
		if d != nil {
			break
		}
		dir, call, errno := f.pfd.OpenDir()