-void source_description_add_user_data(Gom_ctxt ctxt, struct user_data* data)
-{
- struct source_description *obj = SAFE_CTXT_CAST(source_description, ctxt);
- if (obj)
- LINK_CHAIN_ELT(user_data, obj->extra, data);
-}
-
-void source_description_cleanup(struct source_description* desc)