-void filter_register(const char *type, filter_constructor_t constructor,
- filter_destructor_t destructor, filter_runner_t runner);
+filter_type_t filter_register(const char *type, filter_constructor_t constructor,
+ filter_destructor_t destructor, filter_runner_t runner);
+
+__attribute__((nonnull(2)))
+filter_result_t filter_hook_register(filter_type_t filter, const char *name);