contain any definitions, only declarations. If a file contains both
definitions and declarations, then the two output files will produce
duplicate symbols and the linker will fail. To avoid this, definitions
must be placed in preambles in other files, or in C source files.

# Passing pointers

Go is a garbage collected language, and the garbage collector needs to

	if sysStat != nil {
		return h, sysStat(fi, h, doNameLookups)
	}
	return h, nil
}

// FileInfoNames extends [fs.FileInfo].
// Passing an instance of this to [FileInfoHeader] permits the caller
// to avoid a system-dependent name lookup by specifying the Uname and Gname directly.
type FileInfoNames interface {
	fs.FileInfo
	// Uname should give a user name.
	Uname() (string, error)
	// Gname should give a group name.

	register["HI"] = mips.REG_HI
	register["LO"] = mips.REG_LO
	// Pseudo-registers.
	register["SB"] = RSB
	register["FP"] = RFP
	register["PC"] = RPC
	// Avoid unintentionally clobbering g using R30.
	delete(register, "R30")
	register["g"] = mips.REG_R30
	// Avoid unintentionally clobbering RSB using R28.
	delete(register, "R28")
	register["RSB"] = mips.REG_R28
	registerPrefix := map[string]bool{
		"F":   true,

(such as [`os.ModeDir`](/pkg/os#ModeDir)) do not have the `ModeIrregular` bit set.

Go 1.23 changed [`os.Readlink`](/pkg/os#Readlink) and [`filepath.EvalSymlinks`](/pkg/path/filepath#EvalSymlinks)
to avoid trying to normalize volumes to drive letters, which was not always even possible.
This behavior is controlled by the `winreadlinkvolume` setting.
For Go 1.23, it defaults to `winreadlinkvolume=1`.

Also, constants are always evaluated as 64-bit unsigned integers.
Thus <code>-2</code> is not the integer value minus two,
but the unsigned 64-bit integer with the same bit pattern.
The distinction rarely matters but
to avoid ambiguity, division or right shift where the right operand's
high bit is set is rejected.
</p>

<h3 id="symbols">Symbols</h3>

<p>
Some symbols, such as <code>R1</code> or <code>LR</code>,

	if atEOF {
		return len(data), dropCR(data), nil
	}
	// Request more data.
	return 0, nil, nil
}

// isSpace reports whether the character is a Unicode white space character.
// We avoid dependency on the unicode package, but check validity of the implementation
// in the tests.
func isSpace(r rune) bool {
	if r <= '\u00FF' {
		// Obvious ASCII ones: \t through \r plus space. Plus two Latin-1 oddballs.

func (as *asciiSet) contains(c byte) bool {
	return (as[c/32] & (1 << (c % 32))) != 0
}

// containsRune is a simplified version of strings.ContainsRune
// to avoid importing the strings package.
// We avoid bytes.ContainsRune to avoid allocating a temporary copy of s.
func containsRune(s string, r rune) bool {
	for _, c := range s {
		if c == r {
			return true
		}
	}
	return false
}

func (tw *Writer) WriteHeader(hdr *Header) error {
	if err := tw.Flush(); err != nil {
		return err
	}
	tw.hdr = *hdr // Shallow copy of Header

	// Avoid usage of the legacy TypeRegA flag, and automatically promote
	// it to use TypeReg or TypeDir.
	if tw.hdr.Typeflag == TypeRegA {
		if strings.HasSuffix(tw.hdr.Name, "/") {
			tw.hdr.Typeflag = TypeDir
		} else {

func (b *Reader) Reset(r io.Reader) {
	// If a Reader r is passed to NewReader, NewReader will return r.
	// Different layers of code may do that, and then later pass r
	// to Reset. Avoid infinite recursion in that case.
	if b == r {
		return
	}
	if b.buf == nil {
		b.buf = make([]byte, defaultBufSize)
	}
	b.reset(b.buf, r)
}

func (b *Reader) reset(buf []byte, r io.Reader) {

	// However, if the os.Stderr (or os.Stdout) file descriptors are
	// passed on, the hanging adb subprocess will hold them open and
	// go test will hang forever.
	//
	// Avoid that by wrapping stderr, breaking the short circuit and
	// forcing cmd.Run to use another pipe and goroutine to pass
	// along stderr from adb.
	cmd.Stderr = struct{ io.Writer }{os.Stderr}
	err := cmd.Run()