// byte is an alias for uint8 and is equivalent to uint8 in all ways. It is
// used, by convention, to distinguish byte values from 8-bit unsigned
// integer values.
type byte = uint8

// rune is an alias for int32 and is equivalent to int32 in all ways. It is
// used, by convention, to distinguish character values from integer values.
type rune = int32

// any is an alias for interface{} and is equivalent to interface{} in all ways.

https://golang.org/doc/articles/c_go_cgo.html.

CFLAGS, CPPFLAGS, CXXFLAGS, FFLAGS and LDFLAGS may be defined with pseudo
#cgo directives within these comments to tweak the behavior of the C, C++
or Fortran compiler. Values defined in multiple directives are concatenated
together. The directive can include a list of build constraints limiting its
effect to systems satisfying one of the constraints

		// Corrupt foo.txt's final crc32 byte, in both
		// the file header and TOC. (0x7e -> 0x7f)
		b[0x11]++
		b[0x9d]++

		// TODO(bradfitz): add a new test that only corrupts
		// one of these values, and verify that that's also an
		// error. Currently, the reader code doesn't verify the
		// fileheader and TOC's crc32 match if they're both
		// non-zero and only the second line above, the TOC,
		// is what matters.

	// the BSD tar utility.
	if size < 0 {
		return false
	}
	var pre sparseEntry
	for _, cur := range sp {
		switch {
		case cur.Offset < 0 || cur.Length < 0:
			return false // Negative values are never okay
		case cur.Offset > math.MaxInt64-cur.Length:
			return false // Integer overflow with large length
		case cur.endOffset() > size:
			return false // Region extends beyond the actual size

		b.uint32(1)           // total number of disks

		if _, err := w.cw.Write(buf[:]); err != nil {
			return err
		}

		// store max values in the regular end record to signal
		// that the zip64 values should be used instead
		records = uint16max
		size = uint32max
		offset = uint32max
	}

	// write end record
	var buf [directoryEndLen]byte
	b := writeBuf(buf[:])

// boundary of the block containing the last newline.
//
// Note that the GNU manual says that numeric values should be encoded in octal
// format. However, the GNU tar utility itself outputs these values in decimal.
// As such, this library treats values as being encoded in decimal.
func readGNUSparseMap1x0(r io.Reader) (sparseDatas, error) {
	var (
		cntNewline int64
		buf        bytes.Buffer