+ array_deep_wipe(filter->params, filter_params_wipe);
+ return ret;
+}
+
+bool filter_update_references(filter_t *filter, A(filter_t) *filter_list)
+{
+ foreach (filter_hook_t *hook, filter->hooks) {
+ if (!hook->postfix) {
+ hook->filter_id = filter_find_with_name(filter_list, hook->value);
+ if (hook->filter_id == -1) {
+ syslog(LOG_ERR, "invalid filter name %s for hook %s",
+ hook->value, htokens[hook->type]);
+ return false;
+ }
+ p_delete(&hook->value);
+ }
+ }}
+ return true;
+}
+
+static inline bool filter_check_loop(filter_t *filter, A(filter_t) *array, int level)
+{
+ if (filter->last_seen == level) {
+ return true;
+ }
+ filter->last_seen = level;
+ foreach (filter_hook_t *hook, filter->hooks) {
+ if (hook->postfix) {
+ continue;
+ }
+ if (hook->filter_id == level) {
+ return false;
+ }
+ if (!filter_check_loop(array_ptr(*array, hook->filter_id), array, level)) {
+ return false;
+ }
+ }}
+ return true;
+}
+
+bool filter_check_safety(A(filter_t) *array)
+{
+ foreach (filter_t *filter, *array) {
+ if (!filter_check_loop(filter, array, __Ai)) {
+ syslog(LOG_ERR, "the filter tree contains a loop");
+ return false;
+ }
+ }}