Rewrite associated types to use projection rather than dummy type parameters

src/librustc/metadata/common.rs

@@ -256,3 +256,6 @@ pub const tag_predicate_space: uint = 0xa9;
 pub const tag_predicate_data: uint = 0xb0;
 
 pub const tag_unsafety: uint = 0xb1;
+
+pub const tag_associated_type_names: uint = 0xb2;
+pub const tag_associated_type_name: uint = 0xb3;

src/librustc/metadata/csearch.rs

@@ -226,7 +226,7 @@ pub fn get_struct_field_attrs(cstore: &cstore::CStore, def: ast::DefId) -> HashM
 
 pub fn get_type<'tcx>(tcx: &ty::ctxt<'tcx>,
                       def: ast::DefId)
-                      -> ty::Polytype<'tcx> {
+                      -> ty::TypeScheme<'tcx> {
     let cstore = &tcx.sess.cstore;
     let cdata = cstore.get_crate_data(def.krate);
     decoder::get_type(&*cdata, def.node, tcx)
@@ -239,7 +239,7 @@ pub fn get_trait_def<'tcx>(tcx: &ty::ctxt<'tcx>, def: ast::DefId) -> ty::TraitDe
 }
 
 pub fn get_field_type<'tcx>(tcx: &ty::ctxt<'tcx>, class_id: ast::DefId,
-                            def: ast::DefId) -> ty::Polytype<'tcx> {
+                            def: ast::DefId) -> ty::TypeScheme<'tcx> {
     let cstore = &tcx.sess.cstore;
     let cdata = cstore.get_crate_data(class_id.krate);
     let all_items = reader::get_doc(rbml::Doc::new(cdata.data()), tag_items);
@@ -257,7 +257,7 @@ pub fn get_field_type<'tcx>(tcx: &ty::ctxt<'tcx>, class_id: ast::DefId,
                     def)).to_string()
         });
     let ty = decoder::item_type(def, the_field, tcx, &*cdata);
-    ty::Polytype {
+    ty::TypeScheme {
         generics: ty::Generics::empty(),
         ty: ty,
     }

src/librustc/metadata/decoder.rs

@@ -172,14 +172,15 @@ fn item_visibility(item: rbml::Doc) -> ast::Visibility {
 }
 
 fn item_sort(item: rbml::Doc) -> char {
-    // NB(pcwalton): The default of 'r' here is relied upon in
-    // `is_associated_type` below.
-    let mut ret = 'r';
+    let mut ret = None;
     reader::tagged_docs(item, tag_item_trait_item_sort, |doc| {
-        ret = doc.as_str_slice().as_bytes()[0] as char;
+        ret = Some(doc.as_str_slice().as_bytes()[0] as char);
         false
     });
-    ret
+    match ret {
+        Some(r) => r,
+        None => panic!("No item_sort found")
+    }
 }
 
 fn item_symbol(item: rbml::Doc) -> String {
@@ -245,13 +246,13 @@ pub fn item_type<'tcx>(_item_id: ast::DefId, item: rbml::Doc,
 }
 
 fn doc_trait_ref<'tcx>(doc: rbml::Doc, tcx: &ty::ctxt<'tcx>, cdata: Cmd)
-                       -> ty::TraitRef<'tcx> {
+                       -> Rc<ty::TraitRef<'tcx>> {
     parse_trait_ref_data(doc.data, cdata.cnum, doc.start, tcx,
                          |_, did| translate_def_id(cdata, did))
 }
 
 fn item_trait_ref<'tcx>(doc: rbml::Doc, tcx: &ty::ctxt<'tcx>, cdata: Cmd)
-                        -> ty::TraitRef<'tcx> {
+                        -> Rc<ty::TraitRef<'tcx>> {
     let tp = reader::get_doc(doc, tag_item_trait_ref);
     doc_trait_ref(tp, tcx, cdata)
 }
@@ -369,6 +370,17 @@ fn parse_unsafety(item_doc: rbml::Doc) -> ast::Unsafety {
     }
 }
 
+fn parse_associated_type_names(item_doc: rbml::Doc) -> Vec<ast::Name> {
+    let names_doc = reader::get_doc(item_doc, tag_associated_type_names);
+    let mut names = Vec::new();
+    reader::tagged_docs(names_doc, tag_associated_type_name, |name_doc| {
+        let name = token::intern(name_doc.as_str_slice());
+        names.push(name);
+        true
+    });
+    names
+}
+
 pub fn get_trait_def<'tcx>(cdata: Cmd,
                            item_id: ast::NodeId,
                            tcx: &ty::ctxt<'tcx>) -> ty::TraitDef<'tcx>
@@ -377,17 +389,19 @@ pub fn get_trait_def<'tcx>(cdata: Cmd,
     let generics = doc_generics(item_doc, tcx, cdata, tag_item_generics);
     let bounds = trait_def_bounds(item_doc, tcx, cdata);
     let unsafety = parse_unsafety(item_doc);
+    let associated_type_names = parse_associated_type_names(item_doc);
 
     ty::TraitDef {
         unsafety: unsafety,
         generics: generics,
         bounds: bounds,
-        trait_ref: Rc::new(item_trait_ref(item_doc, tcx, cdata))
+        trait_ref: item_trait_ref(item_doc, tcx, cdata),
+        associated_type_names: associated_type_names,
     }
 }
 
 pub fn get_type<'tcx>(cdata: Cmd, id: ast::NodeId, tcx: &ty::ctxt<'tcx>)
-    -> ty::Polytype<'tcx> {
+    -> ty::TypeScheme<'tcx> {
 
     let item = lookup_item(id, cdata.data());
 
@@ -396,7 +410,7 @@ pub fn get_type<'tcx>(cdata: Cmd, id: ast::NodeId, tcx: &ty::ctxt<'tcx>)
 
     let generics = doc_generics(item, tcx, cdata, tag_item_generics);
 
-    ty::Polytype {
+    ty::TypeScheme {
         generics: generics,
         ty: t
     }
@@ -428,7 +442,7 @@ pub fn get_impl_trait<'tcx>(cdata: Cmd,
 {
     let item_doc = lookup_item(id, cdata.data());
     reader::maybe_get_doc(item_doc, tag_item_trait_ref).map(|tp| {
-        Rc::new(doc_trait_ref(tp, tcx, cdata))
+        doc_trait_ref(tp, tcx, cdata)
     })
 }
 
@@ -924,7 +938,7 @@ pub fn get_supertraits<'tcx>(cdata: Cmd, id: ast::NodeId, tcx: &ty::ctxt<'tcx>)
         // FIXME(#8559): The builtin bounds shouldn't be encoded in the first place.
         let trait_ref = doc_trait_ref(trait_doc, tcx, cdata);
         if tcx.lang_items.to_builtin_kind(trait_ref.def_id).is_none() {
-            results.push(Rc::new(trait_ref));
+            results.push(trait_ref);
         }
         true
     });
@@ -1353,7 +1367,7 @@ pub fn get_dylib_dependency_formats(cdata: Cmd)
         if spec.len() == 0 { continue }
         let cnum = spec.split(':').nth(0).unwrap();
         let link = spec.split(':').nth(1).unwrap();
-        let cnum = cnum.parse().unwrap();
+        let cnum: ast::CrateNum = cnum.parse().unwrap();
         let cnum = match cdata.cnum_map.get(&cnum) {
             Some(&n) => n,
             None => panic!("didn't find a crate in the cnum_map")

src/librustc/metadata/encoder.rs

@@ -142,7 +142,7 @@ fn encode_item_variances(rbml_w: &mut Encoder,
 
 fn encode_bounds_and_type<'a, 'tcx>(rbml_w: &mut Encoder,
                                     ecx: &EncodeContext<'a, 'tcx>,
-                                    pty: &ty::Polytype<'tcx>) {
+                                    pty: &ty::TypeScheme<'tcx>) {
     encode_generics(rbml_w, ecx, &pty.generics, tag_item_generics);
     encode_type(ecx, rbml_w, pty.ty);
 }
@@ -898,7 +898,10 @@ fn encode_info_for_associated_type(ecx: &EncodeContext,
     encode_visibility(rbml_w, associated_type.vis);
     encode_family(rbml_w, 'y');
     encode_parent_item(rbml_w, local_def(parent_id));
-    encode_item_sort(rbml_w, 'r');
+    encode_item_sort(rbml_w, 't');
+
+    let type_scheme = ty::lookup_item_type(ecx.tcx, associated_type.def_id);
+    encode_bounds_and_type(rbml_w, ecx, &type_scheme);
 
     let stab = stability::lookup(ecx.tcx, associated_type.def_id);
     encode_stability(rbml_w, stab);
@@ -1316,6 +1319,7 @@ fn encode_info_for_item(ecx: &EncodeContext,
         encode_item_variances(rbml_w, ecx, item.id);
         let trait_def = ty::lookup_trait_def(tcx, def_id);
         encode_unsafety(rbml_w, trait_def.unsafety);
+        encode_associated_type_names(rbml_w, trait_def.associated_type_names.as_slice());
         encode_generics(rbml_w, ecx, &trait_def.generics, tag_item_generics);
         encode_trait_ref(rbml_w, ecx, &*trait_def.trait_ref, tag_item_trait_ref);
         encode_name(rbml_w, item.ident.name);
@@ -1397,10 +1401,13 @@ fn encode_info_for_item(ecx: &EncodeContext,
                         ty::StaticExplicitSelfCategory;
                 }
                 ty::TypeTraitItem(associated_type) => {
+                    encode_name(rbml_w, associated_type.name);
+
                     let elem = ast_map::PathName(associated_type.name);
                     encode_path(rbml_w,
                                 path.clone().chain(Some(elem).into_iter()));
 
+                    encode_item_sort(rbml_w, 't');
                     encode_family(rbml_w, 'y');
 
                     is_nonstatic_method = false;
@@ -1689,6 +1696,14 @@ fn encode_unsafety(rbml_w: &mut Encoder, unsafety: ast::Unsafety) {
     rbml_w.wr_tagged_u8(tag_unsafety, byte);
 }
 
+fn encode_associated_type_names(rbml_w: &mut Encoder, names: &[ast::Name]) {
+    rbml_w.start_tag(tag_associated_type_names);
+    for &name in names.iter() {
+        rbml_w.wr_tagged_str(tag_associated_type_name, token::get_name(name).get());
+    }
+    rbml_w.end_tag();
+}
+
 fn encode_crate_deps(rbml_w: &mut Encoder, cstore: &cstore::CStore) {
     fn get_ordered_deps(cstore: &cstore::CStore) -> Vec<decoder::CrateDep> {
         // Pull the cnums and name,vers,hash out of cstore