file  string // Optional filename of expected output
		tests []testFnc
	}{{
		// The writer test file was produced with this command:
		// tar (GNU tar) 1.26
		//   ln -s small.txt link.txt
		//   tar -b 1 --format=ustar -c -f writer.tar small.txt small2.txt link.txt
		file: "testdata/writer.tar",
		tests: []testFnc{
			testHeader{Header{
				Typeflag: TypeReg,
				Name:     "small.txt",
				Size:     5,
				Mode:     0640,

	d.dirDiskNbr = b.uint32()         // number of the disk with the start of the central directory
	d.dirRecordsThisDisk = b.uint64() // total number of entries in the central directory on this disk
	d.directoryRecords = b.uint64()   // total number of entries in the central directory
	d.directorySize = b.uint64()      // size of the central directory
	d.directoryOffset = b.uint64()    // offset of start of central directory with respect to the starting disk number

		if s.err != nil {
			// Shut it down.
			s.start = 0
			s.end = 0
			return false
		}
		// Must read more data.
		// First, shift data to beginning of buffer if there's lots of empty space
		// or space is needed.
		if s.start > 0 && (s.end == len(s.buf) || s.start > len(s.buf)/2) {
			copy(s.buf, s.buf[s.start:s.end])
			s.end -= s.start
			s.start = 0
		}
		// Is the buffer full? If so, resize.

		t.Fatalf("expected function name %v; got %v", symName, funcName)
	}
	fi1, err := os.Stat("addr2line_test.go")
	if err != nil {
		t.Fatalf("Stat failed: %v", err)
	}

	// Debug paths are stored slash-separated, so convert to system-native.
	srcPath = filepath.FromSlash(srcPath)
	fi2, err := os.Stat(srcPath)

	if err != nil {
		t.Fatalf("Stat failed: %v", err)
	}
	if !os.SameFile(fi1, fi2) {

	{"4611686018427387904", 4611686018427387904, true},
}

func TestExpr(t *testing.T) {
	p := NewParser(nil, nil, nil) // Expression evaluation uses none of these fields of the parser.
	for i, test := range exprTests {
		p.start(lex.Tokenize(test.input))
		result := int64(p.expr())
		if result != test.output {
			t.Errorf("%d: %q evaluated to %d; expected %d", i, test.input, result, test.output)
		}
		tok := p.next()

There are no runtime metrics for this change,
This setting may be removed in a future release, Go 1.27 at the earliest.

Go 1.23 changed the mode bits reported by [`os.Lstat`](/pkg/os#Lstat) and [`os.Stat`](/pkg/os#Stat)
for reparse points, which can be controlled with the `winsymlink` setting.
As of Go 1.23 (`winsymlink=1`), mount points no longer have [`os.ModeSymlink`](/pkg/os#ModeSymlink)

(The prototype will also let <code>go</code> <code>vet</code> check the argument references.)
At the start of the function, the arguments are assumed
to be initialized but the results are assumed uninitialized.
If the results will hold live pointers during a call instruction,
the function should start by zeroing the results and then
executing the pseudo-instruction <code>GO_RESULTS_INITIALIZED</code>.

// See the [ZIP specification] for details.
//
// [ZIP specification]: https://support.pkware.com/pkzip/appnote
type FileHeader struct {
	// Name is the name of the file.
	//
	// It must be a relative path, not start with a drive letter (such as "C:"),
	// and must use forward slashes instead of back slashes. A trailing slash
	// indicates that this file is a directory and should have no data.
	Name string

func TestIndexByteBig(t *testing.T) {
	var n = 1024
	if testing.Short() {
		n = 128
	}
	b := make([]byte, n)
	for i := 0; i < n; i++ {
		// different start alignments
		b1 := b[i:]
		for j := 0; j < len(b1); j++ {
			b1[j] = 'x'
			pos := IndexByte(b1, 'x')
			if pos != j {
				t.Errorf("IndexByte(%q, 'x') = %v", b1, pos)
			}
			b1[j] = 0

	// more efficient, possibly due to cache effects.
	start := -1 // valid span start if >= 0
	for i := 0; i < len(s); {
		size := 1
		r := rune(s[i])
		if r >= utf8.RuneSelf {
			r, size = utf8.DecodeRune(s[i:])
		}
		if f(r) {
			if start >= 0 {
				spans = append(spans, span{start, i})
				start = -1
			}
		} else {
			if start < 0 {
				start = i
			}
		}
		i += size
	}