stub out trait aliases in save_analysis

Author: durka

src/librustc_save_analysis/dump_visitor.rs

@@ -285,6 +285,7 @@ impl<'l, 'tcx: 'l, 'll, O: DumpOutput + 'll> DumpVisitor<'l, 'tcx, 'll, O> {
             HirDef::Enum(..) |
             HirDef::TyAlias(..) |
             HirDef::TyForeign(..) |
+            HirDef::TraitAlias(..) |
             HirDef::Trait(_) => {
                 let span = self.span_from_span(sub_span.expect("No span found for type ref"));
                 self.dumper.dump_ref(Ref {

src/librustc_save_analysis/lib.rs

@@ -721,6 +721,7 @@ impl<'l, 'tcx: 'l> SaveContext<'l, 'tcx> {
             HirDef::Enum(def_id) |
             HirDef::TyAlias(def_id) |
             HirDef::TyForeign(def_id) |
+            HirDef::TraitAlias(def_id) |
             HirDef::AssociatedTy(def_id) |
             HirDef::Trait(def_id) |
             HirDef::TyParam(def_id) => {

src/librustc_save_analysis/sig.rs

@@ -487,6 +487,25 @@ impl Sig for ast::Item {
 
                 Ok(sig)
             }
+            ast::ItemKind::TraitAlias(ref generics, ref bounds) => {
+                let mut text = String::new();
+                text.push_str("trait ");
+                let mut sig = name_and_generics(text,
+                                                offset,
+                                                generics,
+                                                self.id,
+                                                self.ident,
+                                                scx)?;
+
+                if !bounds.is_empty() {
+                    sig.text.push_str(" = ");
+                    sig.text.push_str(&pprust::bounds_to_string(bounds));
+                }
+                // FIXME where clause
+                sig.text.push_str(";");
+
+                Ok(sig)
+            }
             ast::ItemKind::AutoImpl(unsafety, ref trait_ref) => {
                 let mut text = String::new();
                 if unsafety == ast::Unsafety::Unsafe {