MalformedType used for all invalid type annotations.

sdk/lib/_internal/compiler/implementation/mirrors/dart2js_mirror.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library mirrors_dart2js;
 
 import 'dart:io';
 import 'dart:uri';
 
 import '../../compiler.dart' as diagnostics;
@@ skipping 57 matching lines @@
       return new Dart2JsInterfaceTypeMirror(system, type);
     }
   } else if (type is TypeVariableType) {
     return new Dart2JsTypeVariableMirror(system, type);
   } else if (type is FunctionType) {
     return new Dart2JsFunctionTypeMirror(system, type, functionSignature);
   } else if (type is VoidType) {
     return new Dart2JsVoidMirror(system, type);
   } else if (type is TypedefType) {
     return new Dart2JsTypedefMirror(system, type);
+  } else if (type is MalformedType) {
+    // TODO(johnniwinther): We need a mirror on malformed types.
+    return system.dynamicType;
   }
-  throw new ArgumentError("Unexpected interface type $type");
+  throw new ArgumentError("Unexpected type $type of kind ${type.kind}");
 }
 
 Collection<Dart2JsMemberMirror> _convertElementMemberToMemberMirrors(
     Dart2JsContainerMirror library, Element element) {
   if (element is SynthesizedConstructorElement) {
     return const <Dart2JsMemberMirror>[];
   } else if (element is VariableElement) {
     return <Dart2JsMemberMirror>[new Dart2JsFieldMirror(library, element)];
   } else if (element is FunctionElement) {
     return <Dart2JsMemberMirror>[new Dart2JsMethodMirror(library, element)];
@@ skipping 1465 matching lines @@
     var node = _variable.variables.parseNode(_diagnosticListener);
     if (node != null) {
       var span = mirrors.compiler.spanFromNode(node, script.uri);
       return new Dart2JsSourceLocation(script, span);
     } else {
       var span = mirrors.compiler.spanFromElement(_variable);
       return new Dart2JsSourceLocation(script, span);
     }
   }
 }