track the extern-crate def-id rather than path

We used to track, for each crate, a path that led to the extern-crate
that imported it. Instead of that, track the def-id of the extern crate,
along with a bit more information, and derive the path on the fly.

1 files changed, 3 insertions, 1 deletions

diff --git a/src/librustc_metadata/decoder.rs b/src/librustc_metadata/decoder.rs
index 562525e956a..561248fc703 100644
--- a/src/librustc_metadata/decoder.rs
+++ b/src/librustc_metadata/decoder.rs
@@ -1763,7 +1763,9 @@ pub fn closure_ty<'tcx>(cdata: Cmd, closure_id: DefIndex, tcx: &TyCtxt<'tcx>)
         .parse_closure_ty()
 }
 
-fn def_key(item_doc: rbml::Doc) -> hir_map::DefKey {
+pub fn def_key(cdata: Cmd, id: DefIndex) -> hir_map::DefKey {
+    debug!("def_key: id={:?}", id);
+    let item_doc = cdata.lookup_item(id);
     match reader::maybe_get_doc(item_doc, tag_def_key) {
         Some(def_key_doc) => {
             let mut decoder = reader::Decoder::new(def_key_doc);