if context == ctxAssign2 {
		context = ctxExpr
	}
	if context == ctxEmbedType {
		error_(sel.Pos(), "cannot embed C type")
	}
	goname := sel.Sel.Name
	if goname == "errno" {
		error_(sel.Pos(), "cannot refer to errno directly; see documentation")
		return
	}
	if goname == "_CMalloc" {
		error_(sel.Pos(), "cannot refer to C._CMalloc; use C.malloc")
		return
	}
	if goname == "malloc" {
		goname = "_CMalloc"
	}

NUL byte.

As Go doesn't have support for C's union type in the general case,
C's union types are represented as a Go byte array with the same length.

Go structs cannot embed fields with C types.

Go code cannot refer to zero-sized fields that occur at the end of
non-empty C structs. To get the address of such a field (which is the
only operation you can do with a zero-sized field) you must take the

		if hasNUL(s) || (tooLong && !allowLongGNU) {
			whyNoGNU = fmt.Sprintf("GNU cannot encode %s=%q", name, s)
			format.mustNotBe(FormatGNU)
		}
		if !isASCII(s) || tooLong {
			canSplitUSTAR := paxKey == paxPath
			if _, _, ok := splitUSTARPath(s); !canSplitUSTAR || !ok {
				whyNoUSTAR = fmt.Sprintf("USTAR cannot encode %s=%q", name, s)
				format.mustNotBe(FormatUSTAR)
			}
			if paxKey == paxNone {

	opReadRune2 readOp = 2  // Read rune of size 2.
	opReadRune3 readOp = 3  // Read rune of size 3.
	opReadRune4 readOp = 4  // Read rune of size 4.
)

// ErrTooLarge is passed to panic if memory cannot be allocated to store data in a buffer.
var ErrTooLarge = errors.New("bytes.Buffer: too large")
var errNegativeRead = errors.New("bytes.Buffer: reader returned negative count from Read")

const maxInt = int(^uint(0) >> 1)

// The cases are auto-generated by disassembler.
// The uncommented cases means they can be handled by assembler
// and they are consistent with disassembler decoding.
// TODO means they cannot be handled by current assembler.

#include "../../../../../runtime/textflag.h"

TEXT asmtest(SB),DUPOK|NOSPLIT,$-8

	AND $(1<<63), R1                           // AND $-9223372036854775808, R1     // 21004192

					s.empties++
					if s.empties > maxConsecutiveEmptyReads {
						panic("bufio.Scan: too many empty tokens without progressing")
					}
				}
				return true
			}
		}
		// We cannot generate a token with what we are holding.
		// If we've already hit EOF or an I/O error, we are done.
		if s.err != nil {
			// Shut it down.
			s.start = 0
			s.end = 0
			return false
		}

	//
	// While this format is compatible with most tar readers,
	// the format has several limitations making it unsuitable for some usages.
	// 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

// 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
}

which are tied to a specific release.
-->

## Introduction {#intro}

Go's emphasis on backwards compatibility is one of its key strengths.
There are, however, times when we cannot maintain complete compatibility.
If code depends on buggy (including insecure) behavior,
then fixing the bug will break that code.
New features can also have similar impacts:

package path followed by a period and the symbol name:
<code>fmt.Printf</code> or <code>math/rand.Int</code>.
Because the assembler's parser treats period and slash as punctuation,
those strings cannot be used directly as identifier names.
Instead, the assembler allows the middle dot character U+00B7
and the division slash U+2215 in identifiers and rewrites them to
plain period and slash.