diff options
| author | Josh Bailey <joshb@google.com> | 2012-03-21 10:00:07 -0700 |
|---|---|---|
| committer | Avneesh Sachdev <avneesh@opensourcerouting.org> | 2012-04-07 13:52:23 -0700 |
| commit | 54dd61227352dd1dd4db4fe76dbf7d2e92522e74 (patch) | |
| tree | da320cdec867ca81748f3b85b772422b386bf376 | |
| parent | 8ced4e82e6f417b13f4bfc09018fc51fd31058e2 (diff) | |
lib: Tweaks to linked list macros
* lib/linklist.h
- Change the listnextnode, listhead and listtail macros so that
they allow the list pointer to be NULL.
- Modify the ALL_LIST_ELEMENTS* macros such that they clear the
data pointer at the beginning and end of the loop.
From: Josh Bailey <joshb@google.com>
Signed-off-by: Avneesh Sachdev <avneesh@opensourcerouting.org>
Signed-off-by: David Lamparter <equinox@diac24.net>
| -rw-r--r-- | lib/linklist.h | 14 |
1 files changed, 7 insertions, 7 deletions
diff --git a/lib/linklist.h b/lib/linklist.h index cc6867cd..f0ae3625 100644 --- a/lib/linklist.h +++ b/lib/linklist.h @@ -54,9 +54,9 @@ struct list void (*del) (void *val); }; -#define listnextnode(X) ((X)->next) -#define listhead(X) ((X)->head) -#define listtail(X) ((X)->tail) +#define listnextnode(X) ((X) ? ((X)->next) : NULL) +#define listhead(X) ((X) ? ((X)->head) : NULL) +#define listtail(X) ((X) ? ((X)->tail) : NULL) #define listcount(X) ((X)->count) #define list_isempty(X) ((X)->head == NULL && (X)->tail == NULL) #define listgetdata(X) (assert((X)->data != NULL), (X)->data) @@ -88,10 +88,10 @@ extern void list_add_list (struct list *, struct list *); * It is safe to delete the listnode using this macro. */ #define ALL_LIST_ELEMENTS(list,node,nextnode,data) \ - (node) = listhead(list); \ + (node) = listhead(list), ((data) = NULL); \ (node) != NULL && \ ((data) = listgetdata(node),(nextnode) = listnextnode(node), 1); \ - (node) = (nextnode) + (node) = (nextnode), ((data) = NULL) /* read-only list iteration macro. * Usage: as per ALL_LIST_ELEMENTS, but not safe to delete the listnode Only @@ -100,9 +100,9 @@ extern void list_add_list (struct list *, struct list *); * of previous macro. */ #define ALL_LIST_ELEMENTS_RO(list,node,data) \ - (node) = listhead(list); \ + (node) = listhead(list), ((data) = NULL);\ (node) != NULL && ((data) = listgetdata(node), 1); \ - (node) = listnextnode(node) + (node) = listnextnode(node), ((data) = NULL) /* these *do not* cleanup list nodes and referenced data, as the functions * do - these macros simply {de,at}tach a listnode from/to a list. |