// goroutine. When a function F calls panic, normal execution of F stops
// immediately. Any functions whose execution was deferred by F are run in
// the usual way, and then F returns to its caller. To the caller G, the
// invocation of F then behaves like a call to panic, terminating G's
// execution and running any deferred functions. This continues until all

func Index(s, sep []byte) int {
	n := len(sep)
	switch {
	case n == 0:
		return 0
	case n == 1:
		return IndexByte(s, sep[0])
	case n == len(s):
		if Equal(sep, s) {
			return 0
		}
		return -1
	case n > len(s):
		return -1
	case n <= bytealg.MaxLen:
		// Use brute force when s and sep both are small
		if len(s) <= bytealg.MaxBruteForce {

	// The C string is allocated in the C heap using malloc.
	// It is the caller's responsibility to arrange for it to be
	// freed, such as by calling C.free (be sure to include stdlib.h
	// if C.free is needed).
	func C.CString(string) *C.char

	// Go []byte slice to C array
	// The C array is allocated in the C heap using malloc.
	// It is the caller's responsibility to arrange for it to be

// initial contents. The new [Buffer] takes ownership of buf, and the
// caller should not use buf after this call. NewBuffer is intended to
// prepare a [Buffer] to read existing data. It can also be used to set
// the initial size of the internal buffer for writing. To do that,
// buf should have the desired capacity but a length of zero.
//
// In most cases, new([Buffer]) (or just declaring a [Buffer] variable) is

	switch m := fs.FileMode(fi.h.Mode) &^ 07777; m {
	case c_ISDIR:
		mode |= fs.ModeDir
	case c_ISFIFO:
		mode |= fs.ModeNamedPipe
	case c_ISLNK:
		mode |= fs.ModeSymlink
	case c_ISBLK:
		mode |= fs.ModeDevice
	case c_ISCHR:
		mode |= fs.ModeDevice
		mode |= fs.ModeCharDevice
	case c_ISSOCK:
		mode |= fs.ModeSocket
	}

	switch fi.h.Typeflag {
	case TypeSymlink:
		mode |= fs.ModeSymlink

		case 1:
			t.Go = c.uint8
		case 2:
			t.Go = c.uint16
		case 4:
			t.Go = c.uint32
		case 8:
			t.Go = c.uint64
		case 1 + signedDelta:
			t.Go = c.int8
		case 2 + signedDelta:
			t.Go = c.int16
		case 4 + signedDelta:
			t.Go = c.int32
		case 8 + signedDelta:
			t.Go = c.int64
		}

	case *dwarf.FloatType:
		switch t.Size {

	// valid UTF-8 string, then we set the UTF-8 bit.
	//
	// For the case, where the user explicitly wants to specify the encoding
	// as UTF-8, they will need to set the flag bit themselves.
	utf8Valid1, utf8Require1 := detectUTF8(fh.Name)
	utf8Valid2, utf8Require2 := detectUTF8(fh.Comment)
	switch {
	case fh.NonUTF8:
		fh.Flags &^= 0x800
	case (utf8Require1 || utf8Require2) && (utf8Valid1 && utf8Valid2):
		fh.Flags |= 0x800

			// walking the tree and copying it piecewise. If the directory tree
			// contains nested modules this could push a lot of unnecessary contents,
			// but for the golang.org/x repos it seems to be significantly (~2x)
			// faster than copying one file at a time (via filepath.WalkDir),
			// apparently due to high latency in 'adb' commands.
			if err := adb("push", modDir, deviceModDir); err != nil {
				return 0, err
			}
		} else {