28   if (!list) return NULL;  in list_new_internal()
47   CHECK(list != NULL);  in list_is_empty()
52   CHECK(list != NULL);  in list_contains()
53   CHECK(data != NULL);  in list_contains()
64   CHECK(list != NULL);  in list_length()
69   CHECK(list != NULL);  in list_front()
76   CHECK(list != NULL);  in list_back()
83   CHECK(list != NULL);  in list_back_node()
90   CHECK(list != NULL);  in list_insert_after()
91   CHECK(prev_node != NULL);  in list_insert_after()
92   CHECK(data != NULL);  in list_insert_after()
106   CHECK(list != NULL);  in list_prepend()
107   CHECK(data != NULL);  in list_prepend()
114   if (list->tail == NULL) list->tail = list->head;  in list_prepend()
120   CHECK(list != NULL);  in list_append()
121   CHECK(data != NULL);  in list_append()
125   node->next = NULL;  in list_append()
127   if (list->tail == NULL) {  in list_append()
139   CHECK(list != NULL);  in list_remove()
140   CHECK(data != NULL);  in list_remove()
163   CHECK(list != NULL);  in list_clear()
166   list->head = NULL;  in list_clear()
167   list->tail = NULL;  in list_clear()
173   CHECK(list != NULL);  in list_foreach()
174   CHECK(callback != NULL);  in list_foreach()
181   return NULL;  in list_foreach()
185   CHECK(list != NULL);  in list_begin()
190   CHECK(list != NULL);  in list_end()
191   return NULL;  in list_end()
195   CHECK(node != NULL);  in list_next()
200   CHECK(node != NULL);  in list_node()
205   CHECK(list != NULL);  in list_free_node_()
206   CHECK(node != NULL);  in list_free_node_()