use syntax::ast::{self, AttrItem, Attribute, MetaItem};
use syntax::attr;
use syntax::attr::HasAttrs;
-use syntax::feature_gate::feature_err;
use syntax::mut_visit::*;
use syntax::ptr::P;
-use syntax::sess::ParseSess;
+use syntax::sess::{feature_err, ParseSess};
use syntax::util::map_in_place::MapInPlace;
use smallvec::SmallVec;