On 10/26/2016 05:29 AM, Halil Pasic wrote: > > > On 10/22/2016 12:52 AM, Jianjun Duan wrote: >> +#define RAW_FIELD(base, offset) >> \ >> + ((char *) (base) + offset) >> + > > Seems you partially adopted Paolo's suggestion for improving the > macros. Is there a particular reason why you did not follow it more > closely? I find the solution with field_at_offset(base, offset, type) > more readable than with RAW_FIELD(base, offset). > field_at_offset is too general. We only use (void **) and (void ***) here. For pointer arithmetic, I think RAW_FIELD is more straightforward.
Thanks, Jianjun >> +/* >> + * Offsets of layout of a tail queue head. >> + */ >> +#define QTAILQ_FIRST_OFFSET 0 >> +#define QTAILQ_LAST_OFFSET (sizeof(void *)) >> +/* >> + * Raw access of elements of a tail queue >> + */ >> +#define QTAILQ_RAW_FIRST(head) >> \ >> + (*((void **) (RAW_FIELD(head, QTAILQ_FIRST_OFFSET)))) >> +#define QTAILQ_RAW_LAST(head) >> \ >> + (*((void ***) (RAW_FIELD(head, QTAILQ_LAST_OFFSET)))) >> + >> +/* >> + * Offsets of layout of a tail queue element. >> + */ >> +#define QTAILQ_NEXT_OFFSET 0 >> +#define QTAILQ_PREV_OFFSET (sizeof(void *)) >> + >> +/* >> + * Raw access of elements of a tail entry >> + */ >> +#define QTAILQ_RAW_NEXT(elm, entry) >> \ >> + (*((void **) (RAW_FIELD(elm, entry + QTAILQ_NEXT_OFFSET)))) >> +#define QTAILQ_RAW_PREV(elm, entry) >> \ >> + (*((void ***) (RAW_FIELD(elm, entry + QTAILQ_PREV_OFFSET)))) >> +/* >> + * Tail queue tranversal using pointer arithmetic. >> + */
