Something

#  define BU_CKMAG(_ptr, _magic, _str)  { \
        if( (!(_ptr)) || ( ((long)(_ptr)) & (sizeof(long)-1) )  ||  \
            *((unsigned long *)(_ptr)) != (unsigned long)(_magic) )  { \
                bu_badmagic( (long *)(_ptr), (unsigned long)_magic, _str, __FILE
        return; \
        } \
        return; \
        }