MAKE_META_CMP_FILTER
char buf[sizeof(META_FILTER_VAR) + sizeof(MAKE_META_CMP_FILTER) + 24];
a = meta_filter(gn, a, MAKE_META_CMP_FILTER);
b = meta_filter(gn, b, MAKE_META_CMP_FILTER);
cmp_filter = metaFilter || metaCmpFilter || Var_Exists(gn, MAKE_META_CMP_FILTER);
metaCmpFilter = Var_Exists(SCOPE_GLOBAL, MAKE_META_CMP_FILTER);