r, w, err := pipe2(&pp, flags)
	if err == nil {
		p[0], p[1] = r, w
	}
	return err
}

//sys	extpread(fd int, p []byte, flags int, offset int64) (n int, err error)

func pread(fd int, p []byte, offset int64) (n int, err error) {
	return extpread(fd, p, 0, offset)
}

//sys	extpwrite(fd int, p []byte, flags int, offset int64) (n int, err error)

	r, w, err := pipe2(&pp, flags)
	if err == nil {
		p[0], p[1] = r, w
	}
	return err
}

//sys	extpread(fd int, p []byte, flags int, offset int64) (n int, err error)

func pread(fd int, p []byte, offset int64) (n int, err error) {
	return extpread(fd, p, 0, offset)
}

//sys	extpwrite(fd int, p []byte, flags int, offset int64) (n int, err error)

	SYS_SYSARCH       = 165 // { int sysarch(int op, char *parms); }
	SYS_RTPRIO        = 166 // { int rtprio(int function, pid_t pid, \
	SYS_EXTPREAD      = 173 // { ssize_t extpread(int fd, void *buf, \
	SYS_EXTPWRITE     = 174 // { ssize_t extpwrite(int fd, const void *buf, \
	SYS_NTP_ADJTIME   = 176 // { int ntp_adjtime(struct timex *tp); }
	SYS_SETGID        = 181 // { int setgid(gid_t gid); }

	SYS_SYSARCH                = 165 // { int sysarch(int op, char *parms); }
	SYS_RTPRIO                 = 166 // { int rtprio(int function, pid_t pid, struct rtprio *rtp); }
	SYS_EXTPREAD               = 173 // { ssize_t extpread(int fd, void *buf, size_t nbyte, int flags, off_t offset); }
	SYS_EXTPWRITE              = 174 // { ssize_t extpwrite(int fd, const void *buf, size_t nbyte, int flags, off_t offset); }

	r = int(r0)
	w = int(r1)
	if e1 != 0 {
		err = errnoErr(e1)
	}
	return
}

// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT

func extpread(fd int, p []byte, flags int, offset int64) (n int, err error) {
	var _p0 unsafe.Pointer
	if len(p) > 0 {
		_p0 = unsafe.Pointer(&p[0])
	} else {
		_p0 = unsafe.Pointer(&_zero)
	}

	r = int(r0)
	w = int(r1)
	if e1 != 0 {
		err = errnoErr(e1)
	}
	return
}

// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT

func extpread(fd int, p []byte, flags int, offset int64) (n int, err error) {
	var _p0 unsafe.Pointer
	if len(p) > 0 {
		_p0 = unsafe.Pointer(&p[0])
	} else {
		_p0 = unsafe.Pointer(&_zero)
	}

	return n, nr.err
}

// tests that we don't ignore errors from our underlying reader
func TestDecoderIssue3577(t *testing.T) {
	next := make(chan nextRead, 10)
	wantErr := errors.New("my error")
	next <- nextRead{5, nil}
	next <- nextRead{10, wantErr}
	next <- nextRead{0, wantErr}
	d := NewDecoder(StdEncoding, &faultInjectReader{
		source: "VHdhcyBicmlsbGlnLCBhbmQgdGhlIHNsaXRoeSB0b3Zlcw==", // twas brillig...
		nextc:  next,

	for {
		changed := false
		for _, id := range exit.contents() {
			b := idToBlock[id]
		NextPred:
			for _, pe := range b.Preds {
				p := pe.b
				if exit.contains(p.ID) {
					continue
				}
				for _, s := range p.Succs {
					if !exit.contains(s.b.ID) {
						continue NextPred
					}
				}
				// All Succs are in exit; add p.
				exit.add(p.ID)
				changed = true
			}
		}

	token.TYPE:        true,
	token.VAR:         true,
}

var declStart = map[token.Token]bool{
	token.IMPORT: true,
	token.CONST:  true,
	token.TYPE:   true,
	token.VAR:    true,
}

var exprEnd = map[token.Token]bool{
	token.COMMA:     true,
	token.COLON:     true,
	token.SEMICOLON: true,
	token.RPAREN:    true,
	token.RBRACK:    true,
	token.RBRACE:    true,
}