not be referenced from Go code; static functions are permitted.

See $GOROOT/cmd/cgo/internal/teststdio and $GOROOT/misc/cgo/gmp for examples. See
"C? Go? Cgo!" for an introduction to using cgo:
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++

		if !validPAXRecord(k, v) {
			return FormatUnknown, nil, headerError{fmt.Sprintf("invalid PAX record: %q", k+" = "+v)}
		}
	}

	// TODO(dsnet): Re-enable this when adding sparse support.
	// See https://golang.org/issue/22735
	/*
		// Check sparse files.
		if len(h.SparseHoles) > 0 || h.Typeflag == TypeGNUSparse {
			if isHeaderOnlyType(h.Typeflag) {
				return FormatUnknown, nil, headerError{"header-only type cannot be sparse"}

// If the allocation fails, it panics with ErrTooLarge.
func growSlice(b []byte, n int) []byte {
	defer func() {
		if recover() != nil {
			panic(ErrTooLarge)
		}
	}()
	// TODO(http://golang.org/issue/51462): We should rely on the append-make
	// pattern so that the compiler can call runtime.growslice. For example:
	//	return append(b, make([]byte, n)...)
	// This avoids unnecessary zero-ing of the first len(b) bytes of the

	// Most notably, it cannot support sparse files, files larger than 8GiB,
	// filenames larger than 256 characters, and non-ASCII filenames.
	//
	// Reference:
	//	http://pubs.opengroup.org/onlinepubs/9699919799/utilities/pax.html#tag_20_92_13_06
	FormatUSTAR

	// FormatPAX represents the PAX header format defined in POSIX.1-2001.
	//
	// PAX extends USTAR by writing a special file with Typeflag TypeXHeader

		case zip64ExtraID:
			f.zip64 = true

			// update directory values from the zip64 extra block.
			// They should only be consulted if the sizes read earlier
			// are maxed out.
			// See golang.org/issue/13367.
			if needUSize {
				needUSize = false
				if len(fieldBuf) < 8 {
					return ErrFormat
				}
				f.UncompressedSize64 = fieldBuf.uint64()
			}
			if needCSize {
				needCSize = false

}

func (tw *Writer) writePAXHeader(hdr *Header, paxHdrs map[string]string) error {
	realName, realSize := hdr.Name, hdr.Size

	// TODO(dsnet): Re-enable this when adding sparse support.
	// See https://golang.org/issue/22735
	/*
		// Handle sparse files.
		var spd sparseDatas
		var spb []byte
		if len(hdr.SparseHoles) > 0 {
			sph := append([]sparseEntry{}, hdr.SparseHoles...) // Copy sparse map

func Repeat(b []byte, count int) []byte {
	if count == 0 {
		return []byte{}
	}

	// Since we cannot return an error on overflow,
	// we should panic if the repeat will generate an overflow.
	// See golang.org/issue/16237.
	if count < 0 {
		panic("bytes: negative Repeat count")
	}
	if len(b) >= maxInt/count {
		panic("bytes: Repeat output length overflow")
	}
	n := len(b) * count

	if len(b) == 0 {

// For example, on return:
//
//	w.importMap["math"] = "math"
//	w.importDir["math"] = "<goroot>/src/math"
//
//	w.importMap["golang.org/x/net/route"] = "vendor/golang.org/x/net/route"
//	w.importDir["vendor/golang.org/x/net/route"] = "<goroot>/src/vendor/golang.org/x/net/route"
//
// Since the set of packages that exist depends on context, the result of

			// then it is impossible to distinguish between a valid GNU file
			// and an invalid pre-Go1.8 file.
			//
			// See https://golang.org/issues/12594
			// See https://golang.org/issues/21005
			if p2.err != nil {
				hdr.AccessTime, hdr.ChangeTime = time.Time{}, time.Time{}
				ustar := tr.blk.toUSTAR()
				if s := p.parseString(ustar.prefix()); isASCII(s) {
					prefix = s

	defer adb("exec-out", "rm", "-rf", deviceGotmp) // Clean up.

	// Determine the package by examining the current working
	// directory, which will look something like
	// "$GOROOT/src/mime/multipart" or "$GOPATH/src/golang.org/x/mobile".
	// We extract everything after the $GOROOT or $GOPATH to run on the
	// same relative directory on the target device.
	importPath, isStd, modPath, modDir, err := pkgPath()
	if err != nil {
		return 0, err