// the [ErrInsecurePath] error and use the returned reader.
func NewReader(r io.ReaderAt, size int64) (*Reader, error) {
	if size < 0 {
		return nil, errors.New("zip: size cannot be negative")
	}
	zr := new(Reader)
	var err error
	if err = zr.init(r, size); err != nil && err != ErrInsecurePath {
		return nil, err
	}
	return zr, err
}

func (r *Reader) init(rdr io.ReaderAt, size int64) error {

	return messWith("crc32-not-streamed.zip", func(b []byte) {
		// 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

	// defined by the GNU manual (e.g., "GNU.sparse.map").
	//
	// Reference:
	//	http://pubs.opengroup.org/onlinepubs/009695399/utilities/pax.html
	FormatPAX

	// FormatGNU represents the GNU header format.
	//
	// The GNU header format is older than the USTAR and PAX standards and
	// is not compatible with them. The GNU format supports
	// arbitrary file sizes, filenames of arbitrary encoding and length,
	// sparse files, and other features.

	case "all", "ret":
		ctxt.Retpoline = true
	}

	ctxt.Bso = bufio.NewWriter(os.Stdout)
	defer ctxt.Bso.Flush()

	architecture.Init(ctxt)

	// Create object file, write header.
	buf, err := bio.Create(*flags.OutputFile)
	if err != nil {
		log.Fatal(err)
	}
	defer buf.Close()

	if !*flags.SymABIs {
		buf.WriteString(objabi.HeaderString())
		fmt.Fprintf(buf, "!\n")
	}

	// Version numbers.
	zipVersion20 = 20 // 2.0
	zipVersion45 = 45 // 4.5 (reads and writes zip64 archives)

	// Limits for non zip64 files.
	uint16max = (1 << 16) - 1
	uint32max = (1 << 32) - 1

	// Extra header IDs.
	//
	// IDs 0..31 are reserved for official use by PKWARE.
	// IDs above that range are defined by third-party vendors.
	// Since ZIP lacked high precision timestamps (nor an official specification

	os.Setenv("GO_ADDR2LINETEST_IS_ADDR2LINE", "1") // Set for subprocesses to inherit.
	os.Exit(m.Run())
}

// addr2linePath returns the path to the "addr2line" binary to run.
func addr2linePath(t testing.TB) string {
	t.Helper()
	testenv.MustHaveExec(t)

	addr2linePathOnce.Do(func() {
		addr2lineExePath, addr2linePathErr = os.Executable()
	})
	if addr2linePathErr != nil {
		t.Fatal(addr2linePathErr)
	}
	return addr2lineExePath
}

type bufReader struct {
	name string
	fn   func(*Reader) string
}

var bufreaders = []bufReader{
	{"1", func(b *Reader) string { return reads(b, 1) }},
	{"2", func(b *Reader) string { return reads(b, 2) }},
	{"3", func(b *Reader) string { return reads(b, 3) }},
	{"4", func(b *Reader) string { return reads(b, 4) }},
	{"5", func(b *Reader) string { return reads(b, 5) }},
	{"7", func(b *Reader) string { return reads(b, 7) }},

		if err != nil {
			return
		}

		type file struct {
			header  *FileHeader
			content []byte
		}
		files := []file{}

		for _, f := range r.File {
			fr, err := f.Open()
			if err != nil {
				continue
			}
			content, err := io.ReadAll(fr)
			if err != nil {
				continue
			}
			files = append(files, file{header: &f.FileHeader, content: content})
			if _, err := r.Open(f.Name); err != nil {

	func C.GoBytes(unsafe.Pointer, C.int) []byte

As a special case, C.malloc does not call the C library malloc directly
but instead calls a Go helper function that wraps the C library malloc
but guarantees never to return nil. If C's malloc indicates out of memory,
the helper function crashes the program, like when Go itself runs out
of memory. Because C.malloc cannot fail, it has no two-result form
that returns errno.

//go:linkname runtime_arena_newArena
func runtime_arena_newArena() unsafe.Pointer

//go:linkname runtime_arena_arena_New
func runtime_arena_arena_New(arena unsafe.Pointer, typ any) any

// Mark as noescape to avoid escaping the slice header.
//
//go:noescape
//go:linkname runtime_arena_arena_Slice
func runtime_arena_arena_Slice(arena unsafe.Pointer, slice any, cap int)

//go:linkname runtime_arena_arena_Free