read_byte
#define CSR_READ(sc, r) (*sc->sc_ios.read_byte)(sc->sc_dev, r)
uint8_t (*read_byte)(device_t, int reg);
if ((c = read_byte()) == EOF) {
while (c = read_byte(), isspace(c) != 0)
c = read_byte();
c = read_byte();
c = read_byte();
c = read_byte();
seen_end_of_comment = c == '*' && (c = read_byte()) == '/';
if ((c = read_byte()) == EOF) {
for (int c; c = read_byte(), c != EOF && c != '\n';)
int c = read_byte();
c = read_byte();