Auto merge of #25785 - arielb1:cleanup-201505, r=eddyb

The caching essentially eliminates "stability checking" time (my attempt to clean-up junk got tangled up with stability, so I added the caching while I was at it).

r? @eddyb

src/librustc/metadata/common.rs

@@ -146,7 +146,7 @@ enum_from_u32! {
         tag_table_closure_kinds = 0x65,
         tag_table_upvar_capture_map = 0x66,
         tag_table_capture_modes = 0x67,
-        tag_table_object_cast_map = 0x68,
+        // GAP 0x68
         tag_table_const_qualif = 0x69,
         tag_table_cast_kinds = 0x6a,
     }

src/librustc/metadata/csearch.rs

@@ -297,15 +297,6 @@ pub fn get_impl_trait<'tcx>(tcx: &ty::ctxt<'tcx>,
     decoder::get_impl_trait(&*cdata, def.node, tcx)
 }
 
-// Given a def_id for an impl, return information about its vtables
-pub fn get_impl_vtables<'tcx>(tcx: &ty::ctxt<'tcx>,
-                              def: ast::DefId)
-                              -> ty::vtable_res<'tcx> {
-    let cstore = &tcx.sess.cstore;
-    let cdata = cstore.get_crate_data(def.krate);
-    decoder::get_impl_vtables(&*cdata, def.node, tcx)
-}
-
 pub fn get_native_libraries(cstore: &cstore::CStore, crate_num: ast::CrateNum)
                             -> Vec<(cstore::NativeLibraryKind, String)> {
     let cdata = cstore.get_crate_data(crate_num);
@@ -389,15 +380,20 @@ pub fn is_const_fn(cstore: &cstore::CStore, did: ast::DefId) -> bool {
     decoder::is_const_fn(&*cdata, did.node)
 }
 
+pub fn is_impl(cstore: &cstore::CStore, did: ast::DefId) -> bool {
+    let cdata = cstore.get_crate_data(did.krate);
+    decoder::is_impl(&*cdata, did.node)
+}
+
 pub fn get_stability(cstore: &cstore::CStore,
                      def: ast::DefId)
                      -> Option<attr::Stability> {
     let cdata = cstore.get_crate_data(def.krate);
     decoder::get_stability(&*cdata, def.node)
 }
 
-pub fn is_staged_api(cstore: &cstore::CStore, def: ast::DefId) -> bool {
-    let cdata = cstore.get_crate_data(def.krate);
+pub fn is_staged_api(cstore: &cstore::CStore, krate: ast::CrateNum) -> bool {
+    let cdata = cstore.get_crate_data(krate);
     let attrs = decoder::get_crate_attributes(cdata.data());
     for attr in &attrs {
         if &attr.name()[..] == "staged_api" {
@@ -414,11 +410,6 @@ pub fn get_repr_attrs(cstore: &cstore::CStore, def: ast::DefId)
     decoder::get_repr_attrs(&*cdata, def.node)
 }
 
-pub fn is_associated_type(cstore: &cstore::CStore, def: ast::DefId) -> bool {
-    let cdata = cstore.get_crate_data(def.krate);
-    decoder::is_associated_type(&*cdata, def.node)
-}
-
 pub fn is_defaulted_trait(cstore: &cstore::CStore, trait_def_id: ast::DefId) -> bool {
     let cdata = cstore.get_crate_data(trait_def_id.krate);
     decoder::is_defaulted_trait(&*cdata, trait_def_id.node)

src/librustc/metadata/decoder.rs

@@ -30,7 +30,6 @@ use middle::lang_items;
 use middle::subst;
 use middle::ty::{ImplContainer, TraitContainer};
 use middle::ty::{self, Ty};
-use middle::astencode::vtable_decoder_helpers;
 use util::nodemap::FnvHashMap;
 
 use std::cell::{Cell, RefCell};
@@ -522,18 +521,6 @@ pub fn get_impl_trait<'tcx>(cdata: Cmd,
     }
 }
 
-pub fn get_impl_vtables<'tcx>(cdata: Cmd,
-                              id: ast::NodeId,
-                              tcx: &ty::ctxt<'tcx>)
-                              -> ty::vtable_res<'tcx>
-{
-    let item_doc = lookup_item(id, cdata.data());
-    let vtables_doc = reader::get_doc(item_doc, tag_item_impl_vtables);
-    let mut decoder = reader::Decoder::new(vtables_doc);
-    decoder.read_vtable_res(tcx, cdata)
-}
-
-
 pub fn get_symbol(data: &[u8], id: ast::NodeId) -> String {
     return item_symbol(lookup_item(id, data));
 }
@@ -1546,6 +1533,14 @@ pub fn is_const_fn(cdata: Cmd, id: ast::NodeId) -> bool {
     }
 }
 
+pub fn is_impl(cdata: Cmd, id: ast::NodeId) -> bool {
+    let item_doc = lookup_item(id, cdata.data());
+    match item_family(item_doc) {
+        Impl => true,
+        _ => false,
+    }
+}
+
 fn doc_generics<'tcx>(base_doc: rbml::Doc,
                       tcx: &ty::ctxt<'tcx>,
                       cdata: Cmd,
@@ -1623,14 +1618,6 @@ fn doc_predicates<'tcx>(base_doc: rbml::Doc,
     ty::GenericPredicates { predicates: predicates }
 }
 
-pub fn is_associated_type(cdata: Cmd, id: ast::NodeId) -> bool {
-    let items = reader::get_doc(rbml::Doc::new(cdata.data()), tag_items);
-    match maybe_find_item(id, items) {
-        None => false,
-        Some(item) => item_sort(item) == Some('t'),
-    }
-}
-
 pub fn is_defaulted_trait(cdata: Cmd, trait_id: ast::NodeId) -> bool {
     let trait_doc = lookup_item(trait_id, cdata.data());
     assert!(item_family(trait_doc) == Family::Trait);

src/librustc/metadata/encoder.rs

@@ -999,7 +999,7 @@ fn encode_extension_implementations(ecx: &EncodeContext,
     });
 }
 
-fn encode_stability(rbml_w: &mut Encoder, stab_opt: Option<attr::Stability>) {
+fn encode_stability(rbml_w: &mut Encoder, stab_opt: Option<&attr::Stability>) {
     stab_opt.map(|stab| {
         rbml_w.start_tag(tag_items_data_item_stability);
         stab.encode(rbml_w).unwrap();
@@ -1215,11 +1215,11 @@ fn encode_info_for_item(ecx: &EncodeContext,
           encode_name(rbml_w, item.ident.name);
           encode_unsafety(rbml_w, unsafety);
 
-          let trait_ref = ty::impl_id_to_trait_ref(tcx, item.id);
+          let trait_ref = ty::impl_trait_ref(tcx, local_def(item.id)).unwrap();
           encode_trait_ref(rbml_w, ecx, trait_ref, tag_item_trait_ref);
           rbml_w.end_tag();
       }
-      ast::ItemImpl(unsafety, polarity, _, ref opt_trait, ref ty, ref ast_items) => {
+      ast::ItemImpl(unsafety, polarity, _, _, ref ty, ref ast_items) => {
         // We need to encode information about the default methods we
         // have inherited, so we drive this based on the impl structure.
         let impl_items = tcx.impl_items.borrow();
@@ -1269,8 +1269,7 @@ fn encode_info_for_item(ecx: &EncodeContext,
             }
             rbml_w.end_tag();
         }
-        if opt_trait.is_some() {
-            let trait_ref = ty::impl_id_to_trait_ref(tcx, item.id);
+        if let Some(trait_ref) = ty::impl_trait_ref(tcx, local_def(item.id)) {
             encode_trait_ref(rbml_w, ecx, trait_ref, tag_item_trait_ref);
         }
         encode_path(rbml_w, path.clone());

src/librustc/middle/astencode.rs

@@ -696,19 +696,6 @@ pub fn encode_cast_kind(ebml_w: &mut Encoder, kind: cast::CastKind) {
 pub trait vtable_decoder_helpers<'tcx> {
     fn read_vec_per_param_space<T, F>(&mut self, f: F) -> VecPerParamSpace<T> where
         F: FnMut(&mut Self) -> T;
-    fn read_vtable_res_with_key(&mut self,
-                                tcx: &ty::ctxt<'tcx>,
-                                cdata: &cstore::crate_metadata)
-                                -> (u32, ty::vtable_res<'tcx>);
-    fn read_vtable_res(&mut self,
-                       tcx: &ty::ctxt<'tcx>, cdata: &cstore::crate_metadata)
-                      -> ty::vtable_res<'tcx>;
-    fn read_vtable_param_res(&mut self,
-                       tcx: &ty::ctxt<'tcx>, cdata: &cstore::crate_metadata)
-                      -> ty::vtable_param_res<'tcx>;
-    fn read_vtable_origin(&mut self,
-                          tcx: &ty::ctxt<'tcx>, cdata: &cstore::crate_metadata)
-                          -> ty::vtable_origin<'tcx>;
 }
 
 impl<'tcx, 'a> vtable_decoder_helpers<'tcx> for reader::Decoder<'a> {
@@ -720,85 +707,6 @@ impl<'tcx, 'a> vtable_decoder_helpers<'tcx> for reader::Decoder<'a> {
         let fns = self.read_to_vec(|this| Ok(f(this))).unwrap();
         VecPerParamSpace::new(types, selfs, fns)
     }
-
-    fn read_vtable_res_with_key(&mut self,
-                                tcx: &ty::ctxt<'tcx>,
-                                cdata: &cstore::crate_metadata)
-                                -> (u32, ty::vtable_res<'tcx>) {
-        self.read_struct("VtableWithKey", 2, |this| {
-            let autoderef = this.read_struct_field("autoderef", 0, |this| {
-                Decodable::decode(this)
-            }).unwrap();
-            Ok((autoderef, this.read_struct_field("vtable_res", 1, |this| {
-                Ok(this.read_vtable_res(tcx, cdata))
-            }).unwrap()))
-        }).unwrap()
-    }
-
-    fn read_vtable_res(&mut self,
-                       tcx: &ty::ctxt<'tcx>,
-                       cdata: &cstore::crate_metadata)
-                       -> ty::vtable_res<'tcx>
-    {
-        self.read_vec_per_param_space(
-            |this| this.read_vtable_param_res(tcx, cdata))
-    }
-
-    fn read_vtable_param_res(&mut self,
-                             tcx: &ty::ctxt<'tcx>, cdata: &cstore::crate_metadata)
-                      -> ty::vtable_param_res<'tcx> {
-        self.read_to_vec(|this| Ok(this.read_vtable_origin(tcx, cdata)))
-             .unwrap().into_iter().collect()
-    }
-
-    fn read_vtable_origin(&mut self,
-                          tcx: &ty::ctxt<'tcx>, cdata: &cstore::crate_metadata)
-        -> ty::vtable_origin<'tcx> {
-        self.read_enum("vtable_origin", |this| {
-            this.read_enum_variant(&["vtable_static",
-                                     "vtable_param",
-                                     "vtable_error",
-                                     "vtable_closure"],
-                                   |this, i| {
-                Ok(match i {
-                  0 => {
-                    ty::vtable_static(
-                        this.read_enum_variant_arg(0, |this| {
-                            Ok(this.read_def_id_nodcx(cdata))
-                        }).unwrap(),
-                        this.read_enum_variant_arg(1, |this| {
-                            Ok(this.read_substs_nodcx(tcx, cdata))
-                        }).unwrap(),
-                        this.read_enum_variant_arg(2, |this| {
-                            Ok(this.read_vtable_res(tcx, cdata))
-                        }).unwrap()
-                    )
-                  }
-                  1 => {
-                    ty::vtable_param(
-                        this.read_enum_variant_arg(0, |this| {
-                            Decodable::decode(this)
-                        }).unwrap(),
-                        this.read_enum_variant_arg(1, |this| {
-                            this.read_uint()
-                        }).unwrap()
-                    )
-                  }
-                  2 => {
-                    ty::vtable_closure(
-                        this.read_enum_variant_arg(0, |this| {
-                            Ok(this.read_def_id_nodcx(cdata))
-                        }).unwrap()
-                    )
-                  }
-                  3 => {
-                    ty::vtable_error
-                  }
-                  _ => panic!("bad enum variant")
-                })
-            })
-        }).unwrap()
-    }
 }
 
 // ___________________________________________________________________________
@@ -1209,13 +1117,6 @@ fn encode_side_tables_for_id(ecx: &e::EncodeContext,
         })
     }
 
-    if let Some(trait_ref) = tcx.object_cast_map.borrow().get(&id) {
-        rbml_w.tag(c::tag_table_object_cast_map, |rbml_w| {
-            rbml_w.id(id);
-            rbml_w.emit_trait_ref(ecx, &trait_ref.0);
-        })
-    }
-
     if let Some(adjustment) = tcx.adjustments.borrow().get(&id) {
         match *adjustment {
             ty::AdjustDerefRef(ref adj) => {
@@ -1800,11 +1701,6 @@ fn decode_side_tables(dcx: &DecodeContext,
                         };
                         dcx.tcx.method_map.borrow_mut().insert(method_call, method);
                     }
-                    c::tag_table_object_cast_map => {
-                        let trait_ref = val_dsr.read_poly_trait_ref(dcx);
-                        dcx.tcx.object_cast_map.borrow_mut()
-                                               .insert(id, trait_ref);
-                    }
                     c::tag_table_adjustments => {
                         let adj: ty::AutoAdjustment = val_dsr.read_auto_adjustment(dcx);
                         dcx.tcx.adjustments.borrow_mut().insert(id, adj);