stub out trait aliases in resolve

Author: durka

src/librustc_resolve/build_reduced_graph.rs

@@ -344,6 +344,11 @@ impl<'a> Resolver<'a> {
  }
  }
 
+ ItemKind::TraitAlias(..) => {
+ let def = Def::TraitAlias(self.definitions.local_def_id(item.id));
+ self.define(parent, ident, TypeNS, (def, vis, sp, expansion));
+ }
+
  // These items live in both the type and value namespaces.
  ItemKind::Struct(ref struct_def, _) => {
  // Define a name in the type namespace.
@@ -411,6 +416,7 @@ impl<'a> Resolver<'a> {
  self.define(parent, ident, TypeNS, (module, vis, sp, expansion));
  self.current_module = module;
  }
+
  ItemKind::MacroDef(..) | ItemKind::Mac(_) => unreachable!(),
  }
  }

src/librustc_resolve/lib.rs

@@ -474,6 +474,7 @@ impl<'a> PathSource<'a> {
  },
  PathSource::Trait => match def {
  Def::Trait(..) => true,
+ Def::TraitAlias(..) => true,
  _ => false,
  },
  PathSource::Expr(..) => match def {
@@ -1935,6 +1936,17 @@ impl<'a> Resolver<'a> {
  });
  }
 
+ ItemKind::TraitAlias(ref generics, ref bounds) => {
+ // Create a new rib for the trait-wide type parameters.
+ self.with_type_parameter_rib(HasTypeParameters(generics, ItemRibKind), |this| {
+ let local_def_id = this.definitions.local_def_id(item.id);
+ this.with_self_rib(Def::SelfTy(Some(local_def_id), None), |this| {
+ this.visit_generics(generics);
+ walk_list!(this, visit_ty_param_bound, bounds);
+ });
+ });
+ }
+
  ItemKind::Mod(_) | ItemKind::ForeignMod(_) => {
  self.with_scope(item.id, |this| {
  visit::walk_item(this, item);