#define countof(array) (sizeof (array) / sizeof ((array)[0]))
/* Zero out a value. */
-#define xzero(x) memset (&(x), '\0', sizeof (x))
+#define xzero(x) memset (&(x), '\0', sizeof ((x)))
/* Convert an ASCII hex digit to the corresponding number between 0
and 15. X should be a hexadecimal digit that satisfies isxdigit;