diff options
Diffstat (limited to 'lib/typesafe.h')
| -rw-r--r-- | lib/typesafe.h | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/lib/typesafe.h b/lib/typesafe.h index b284397d98..06fdc52e78 100644 --- a/lib/typesafe.h +++ b/lib/typesafe.h @@ -43,6 +43,22 @@ extern "C" { item; \ item = from, from = prefix##_next_safe(head, from)) +/* reverse direction, only supported by a few containers */ + +#define frr_rev_each(prefix, head, item) \ + for (item = prefix##_last(head); item; \ + item = prefix##_prev(head, item)) +#define frr_rev_each_safe(prefix, head, item) \ + for (typeof(prefix##_prev_safe(head, NULL)) prefix##_safe = \ + prefix##_prev_safe(head, \ + (item = prefix##_last(head))); \ + item; \ + item = prefix##_safe, \ + prefix##_safe = prefix##_prev_safe(head, prefix##_safe)) +#define frr_rev_each_from(prefix, head, item, from) \ + for (item = from, from = prefix##_prev_safe(head, item); \ + item; \ + item = from, from = prefix##_prev_safe(head, from)) /* non-const variants. these wrappers are the same for all the types, so * bundle them together here. @@ -57,6 +73,16 @@ macro_pure type *prefix ## _next(struct prefix##_head *h, type *item) \ return (type *)prefix ## _const_next(h, item); \ } \ /* ... */ +#define TYPESAFE_LAST_PREV(prefix, type) \ +macro_pure type *prefix ## _last(struct prefix##_head *h) \ +{ \ + return (type *)prefix ## _const_last(h); \ +} \ +macro_pure type *prefix ## _prev(struct prefix##_head *h, type *item) \ +{ \ + return (type *)prefix ## _const_prev(h, item); \ +} \ +/* ... */ #define TYPESAFE_FIND(prefix, type) \ macro_inline type *prefix ## _find(struct prefix##_head *h, \ const type *item) \ @@ -398,12 +424,34 @@ macro_pure const type *prefix ## _const_next(const struct prefix##_head *h, \ return container_of(ditem->next, type, field.di); \ } \ TYPESAFE_FIRST_NEXT(prefix, type) \ +macro_pure const type *prefix ## _const_last(const struct prefix##_head *h) \ +{ \ + const struct dlist_item *ditem = h->dh.hitem.prev; \ + if (ditem == &h->dh.hitem) \ + return NULL; \ + return container_of(ditem, type, field.di); \ +} \ +macro_pure const type *prefix ## _const_prev(const struct prefix##_head *h, \ + const type *item) \ +{ \ + const struct dlist_item *ditem = &item->field.di; \ + if (ditem->prev == &h->dh.hitem) \ + return NULL; \ + return container_of(ditem->prev, type, field.di); \ +} \ +TYPESAFE_LAST_PREV(prefix, type) \ macro_pure type *prefix ## _next_safe(struct prefix##_head *h, type *item) \ { \ if (!item) \ return NULL; \ return prefix ## _next(h, item); \ } \ +macro_pure type *prefix ## _prev_safe(struct prefix##_head *h, type *item) \ +{ \ + if (!item) \ + return NULL; \ + return prefix ## _prev(h, item); \ +} \ macro_pure size_t prefix ## _count(const struct prefix##_head *h) \ { \ return h->dh.count; \ |