Add names to BareFnTy

src/librustc/hir/intravisit.rs

@@ -574,7 +574,7 @@ pub fn walk_ty<'v, V: Visitor<'v>>(visitor: &mut V, typ: &'v Ty) {
         TyTup(ref tuple_element_types) => {
             walk_list!(visitor, visit_ty, tuple_element_types);
         }
-        TyBareFn(ref function_declaration) => {
+        TyBareFn(ref function_declaration, _) => {
             visitor.visit_fn_decl(&function_declaration.decl);
             walk_list!(visitor, visit_lifetime_def, &function_declaration.lifetimes);
         }

src/librustc/hir/lowering.rs

@@ -673,7 +673,15 @@ fn lower_ty(&mut self, t: &Ty) -> P<hir::Ty> {
                     unsafety: self.lower_unsafety(f.unsafety),
                     abi: f.abi,
                     decl: self.lower_fn_decl(&f.decl),
-                }))
+                },
+                decl.inputs.iter().map(|arg| {
+                    match arg.pat.node {
+                        PatKind::Ident(_, ident, None) => {
+                            respan(ident.span, ident.node.name)
+                        }
+                        _ => respan(arg.pat.span, keywords::Invalid.name()),
+                    }
+                }).collect()))
             }
             TyKind::Never => hir::TyNever,
             TyKind::Tup(ref tys) => {