// Max length of a special file (PAX header, GNU long name or link).
	// This matches the limit used by libarchive.
	maxSpecialFileSize = 1 << 20
)

// blockPadding computes the number of bytes needed to pad offset up to the
// nearest block edge where 0 <= n < blockSize.
func blockPadding(offset int64) (n int64) {
	return -offset & (blockSize - 1)
}

var zeroBlock block

type block [blockSize]byte

	// fileList is a list of files sorted by ename,
	// for use by the Open method.
	fileListOnce sync.Once
	fileList     []fileListEntry
}

// A ReadCloser is a [Reader] that must be closed when no longer needed.
type ReadCloser struct {
	f *os.File
	Reader
}

// A File is a single file in a ZIP archive.
// The file information is in the embedded [FileHeader].
// The file content can be accessed by calling [File.Open].

			// 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.

	}
	return r1, r2, scale, true
}

// registerShift parses an ARM/ARM64 shifted register reference and returns the encoded representation.
// There is known to be a register (current token) and a shift operator (peeked token).
func (p *Parser) registerShift(name string, prefix rune) int64 {
	if prefix != 0 {
		p.errorf("prefix %c not allowed for shifted register: $%s", prefix, name)
	}
	// R1 op R2 or r1 op constant.
	// op is:

(it does not need to implement a complete ELF and Mach-O linker) and
that gcc is not needed after the package is compiled. For example,
package net uses cgo for access to name resolution functions provided
by libc. Although gcc is needed to compile package net, gcc is not
needed to link programs that import package net.

Runtime

When using cgo, Go must not assume that it owns all details of the

// not be accessed once that happens. An Arena is automatically freed once
// it is no longer referenced, so it must be kept alive (see runtime.KeepAlive)
// until any memory allocated from it is no longer needed.
//
// An Arena must never be used concurrently by multiple goroutines.
type Arena struct {
	a unsafe.Pointer
}

// NewArena allocates a new arena.
func NewArena() *Arena {

	"time"
)

type ZipTest struct {
	Name     string
	Source   func() (r io.ReaderAt, size int64) // if non-nil, used instead of testdata/<Name> file
	Comment  string
	File     []ZipTestFile
	Obscured bool  // needed for Apple notarization (golang.org/issue/34986)
	Error    error // the error that Opening this file should return
}

type ZipTestFile struct {
	Name     string
	Mode     fs.FileMode
	NonUTF8  bool

func (b *Buffer) Grow(n int) {
	if n < 0 {
		panic("bytes.Buffer.Grow: negative count")
	}
	m := b.grow(n)
	b.buf = b.buf[:m]
}

// Write appends the contents of p to the buffer, growing the buffer as
// needed. The return value n is the length of p; err is always nil. If the
// buffer becomes too large, Write will panic with [ErrTooLarge].
func (b *Buffer) Write(p []byte) (n int, err error) {
	b.lastRead = opInvalid

		b.uint64(directory64EndLen - 12) // length minus signature (uint32) and length fields (uint64)
		b.uint16(zipVersion45)           // version made by
		b.uint16(zipVersion45)           // version needed to extract
		b.uint32(0)                      // number of this disk
		b.uint32(0)                      // number of the disk with the start of the central directory

explicitly in Go to pointers to arrays, as they do (implicitly) in C.

Garbage collection is the big problem.  It is fine for the Go world to
have pointers into the C world and to free those pointers when they
are no longer needed.  To help, the Go code can define Go objects
holding the C pointers and use runtime.SetFinalizer on those Go objects.

It is much more difficult for the C world to have pointers into the Go