Reflection on generics.

runtime/lib/mirrors.cc

 // 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.
 
 #include "lib/invocation_mirror.h"
 #include "vm/bootstrap_natives.h"
+#include "vm/class_finalizer.h"
 #include "vm/dart_entry.h"
 #include "vm/exceptions.h"
 #include "vm/object_store.h"
 #include "vm/port.h"
 #include "vm/symbols.h"
 
 namespace dart {
 
 static RawInstance* CreateMirror(const String& mirror_class_name,
                                  const Array& constructor_arguments) {
@@ skipping 74 matching lines @@
     type ^= args.TypeAt(i);
     ASSERT(type.IsTypeParameter());
     name ^= type.name();
     result.SetAt(2 * i, name);
     result.SetAt(2 * i + 1, type);
   }
   return result.raw();
 }
 
 
-static RawInstance* CreateTypedefMirror(const Class& cls,
+static RawInstance* CreateTypedefMirror(const AbstractType& type,
                                         const Instance& owner_mirror) {
+  const Class& cls = Class::Handle(type.type_class());
   const Array& args = Array::Handle(Array::New(3));
-  args.SetAt(0, MirrorReference::Handle(MirrorReference::New(cls)));
+  args.SetAt(0, MirrorReference::Handle(MirrorReference::New(type)));
   args.SetAt(1, String::Handle(cls.UserVisibleName()));
   args.SetAt(2, owner_mirror);
   return CreateMirror(Symbols::_LocalTypedefMirrorImpl(), args);
 }
 
 
-static RawInstance* CreateFunctionTypeMirror(const Class& cls) {
+static RawInstance* CreateFunctionTypeMirror(const AbstractType& type) {
   const Array& args = Array::Handle(Array::New(1));
-  args.SetAt(0, MirrorReference::Handle(MirrorReference::New(cls)));
+  args.SetAt(0, MirrorReference::Handle(MirrorReference::New(type)));
   return CreateMirror(Symbols::_LocalFunctionTypeMirrorImpl(), args);
 }
 
 
 static RawInstance* CreateMethodMirror(const Function& func,
                                        const Instance& owner_mirror) {
   const Array& args = Array::Handle(Array::New(12));
   args.SetAt(0, MirrorReference::Handle(MirrorReference::New(func)));
   args.SetAt(1, String::Handle(func.UserVisibleName()));
   args.SetAt(2, owner_mirror);
@@ skipping 23 matching lines @@
   args.SetAt(1, name);
   args.SetAt(2, owner_mirror);
   args.SetAt(3, Instance::Handle());  // Null for type.
   args.SetAt(4, field.is_static() ? Bool::True() : Bool::False());
   args.SetAt(5, field.is_final()  ? Bool::True() : Bool::False());
 
   return CreateMirror(Symbols::_LocalVariableMirrorImpl(), args);
 }
 
 
-static RawInstance* CreateClassMirror(const Class& cls,
+static RawInstance* CreateClassMirror(const AbstractType& type,
                                       const Instance& owner_mirror) {
+  const Class& cls = Class::Handle(type.type_class());
   if (cls.IsSignatureClass()) {
     if (cls.IsCanonicalSignatureClass()) {
       // We represent function types as canonical signature classes.
-      return CreateFunctionTypeMirror(cls);
+      return CreateFunctionTypeMirror(type);
     } else {
       // We represent typedefs as non-canonical signature classes.
-      return CreateTypedefMirror(cls, owner_mirror);
+      return CreateTypedefMirror(type, owner_mirror);
     }
   }
 
   const Array& args = Array::Handle(Array::New(2));
-  args.SetAt(0, MirrorReference::Handle(MirrorReference::New(cls)));
+  args.SetAt(0, MirrorReference::Handle(MirrorReference::New(type)));
   args.SetAt(1, String::Handle(cls.UserVisibleName()));
   return CreateMirror(Symbols::_LocalClassMirrorImpl(), args);
 }
 
+// Note a "raw type" is not the same as a RawType.
+static RawAbstractType* RawTypeOfClass(const Class& klass) {
+  AbstractTypeArguments& type_arguments = AbstractTypeArguments::Handle();
+  Type& type =
+      Type::Handle(Type::New(klass, type_arguments, Scanner::kDummyTokenIndex));
+  return ClassFinalizer::FinalizeType(klass,
+                                      type,
+                                      ClassFinalizer::kCanonicalize);
+}
+
+static RawInstance* CreateGenericClassMirror(const Class& klass,
+                                             const Instance& owner_mirror) {
+  return CreateClassMirror(AbstractType::Handle(RawTypeOfClass(klass)),
+                           owner_mirror);
+}
+
 
 static RawInstance* CreateLibraryMirror(const Library& lib) {
   const Array& args = Array::Handle(Array::New(3));
   args.SetAt(0, MirrorReference::Handle(MirrorReference::New(lib)));
   String& str = String::Handle();
   str = lib.name();
   args.SetAt(1, str);
   str = lib.url();
   args.SetAt(2, str);
   return CreateMirror(Symbols::_LocalLibraryMirrorImpl(), args);
 }
 
 
 static RawInstance* CreateTypeMirror(const AbstractType& type) {
   ASSERT(!type.IsMalformed());
   if (type.HasResolvedTypeClass()) {
     const Class& cls = Class::Handle(type.type_class());
     // Handle void and dynamic types.
     if (cls.IsVoidClass()) {
       Array& args = Array::Handle(Array::New(1));
       args.SetAt(0, Symbols::Void());
       // TODO(mlippautz): Create once in the VM isolate and retrieve from there.
       return CreateMirror(Symbols::_SpecialTypeMirrorImpl(), args);
     } else if (cls.IsDynamicClass()) {
       Array& args = Array::Handle(Array::New(1));
       args.SetAt(0, Symbols::Dynamic());
       // TODO(mlippautz): Create once in the VM isolate and retrieve from there.
       return CreateMirror(Symbols::_SpecialTypeMirrorImpl(), args);
     }
-    return CreateClassMirror(cls, Object::null_instance());
+    return CreateClassMirror(type, Object::null_instance());
   } else if (type.IsTypeParameter()) {
     return CreateTypeVariableMirror(TypeParameter::Cast(type),
                                     Object::null_instance());
   }
   UNREACHABLE();
   return Instance::null();
 }
 
 
 static RawInstance* CreateIsolateMirror() {
@@ skipping 36 matching lines @@
 }
 
 
 DEFINE_NATIVE_ENTRY(Mirrors_makeLocalMirrorSystem, 0) {
   return CreateMirrorSystem();
 }
 
 
 DEFINE_NATIVE_ENTRY(Mirrors_makeLocalClassMirror, 1) {
   GET_NON_NULL_NATIVE_ARGUMENT(Type, type, arguments->NativeArgAt(0));
-  const Class& cls = Class::Handle(type.type_class());
-  return CreateClassMirror(cls, Object::null_instance());
+  return CreateClassMirror(type, Object::null_instance());
 }
 
 
 static void ThrowMirroredCompilationError(const String& message) {
   Array& args = Array::Handle(Array::New(1));
   args.SetAt(0, message);
 
   Exceptions::ThrowByType(Exceptions::kMirroredCompilationError, args);
   UNREACHABLE();
 }
@@ skipping 15 matching lines @@
 DEFINE_NATIVE_ENTRY(MirrorReference_equals, 2) {
   GET_NON_NULL_NATIVE_ARGUMENT(MirrorReference, a, arguments->NativeArgAt(0));
   GET_NON_NULL_NATIVE_ARGUMENT(MirrorReference, b, arguments->NativeArgAt(1));
   return Bool::Get(a.referent() == b.referent());
 }
 
 
 DEFINE_NATIVE_ENTRY(DeclarationMirror_metadata, 1) {
   const MirrorReference& decl_ref =
       MirrorReference::CheckedHandle(arguments->NativeArgAt(0));
-  const Object& decl = Object::Handle(decl_ref.referent());
+  Object& decl = Object::Handle(decl_ref.referent());
 
   Class& klass = Class::Handle();
   Library& library = Library::Handle();
 
-  if (decl.IsClass()) {
-    klass ^= decl.raw();
+  if (decl.IsAbstractType() || decl.IsType()) {
+    klass = AbstractType::Cast(decl).type_class();
     library = klass.library();
+    decl = klass.raw();
   } else if (decl.IsFunction()) {
     klass = Function::Cast(decl).origin();
     library = klass.library();
   } else if (decl.IsField()) {
     klass = Field::Cast(decl).origin();
     library = klass.library();
   } else if (decl.IsLibrary()) {
     library ^= decl.raw();
   } else {
     return Object::empty_array().raw();
   }
 
   const Object& metadata = Object::Handle(library.GetMetadata(decl));
   if (metadata.IsError()) {
     ThrowInvokeError(Error::Cast(metadata));
   }
   return metadata.raw();
 }
 
 
 DEFINE_NATIVE_ENTRY(FunctionTypeMirror_parameters, 1) {
   GET_NON_NULL_NATIVE_ARGUMENT(MirrorReference, ref, arguments->NativeArgAt(0));
-  const Class& cls = Class::Handle(ref.GetClassReferent());
-  const Function& func = Function::Handle(cls.signature_function());
+  const AbstractType& type =
+      AbstractType::Handle(ref.GetAbstractTypeReferent());
+  const Class& klass = Class::Handle(type.type_class());
+  const Function& func = Function::Handle(klass.signature_function());
   return CreateParameterMirrorList(func);
 }
 
 
 DEFINE_NATIVE_ENTRY(FunctionTypeMirror_return_type, 1) {
   GET_NON_NULL_NATIVE_ARGUMENT(MirrorReference, ref, arguments->NativeArgAt(0));
-  const Class& cls = Class::Handle(ref.GetClassReferent());
-  const Function& func = Function::Handle(cls.signature_function());
+  const AbstractType& type =
+      AbstractType::Handle(ref.GetAbstractTypeReferent());
+  const Class& klass = Class::Handle(type.type_class());
+  const Function& func = Function::Handle(klass.signature_function());
   const AbstractType& return_type = AbstractType::Handle(func.result_type());
   return CreateTypeMirror(return_type);
 }
 
 
 static bool FieldIsUninitialized(const Field& field) {
   ASSERT(!field.IsNull());
 
   // Return getter method for uninitialized fields, rather than the
   // field object, since the value in the field object will not be
   // initialized until the first time the getter is invoked.
   const Instance& value = Instance::Handle(field.value());
   ASSERT(value.raw() != Object::transition_sentinel().raw());
   return value.raw() == Object::sentinel().raw();
 }
 
 
 DEFINE_NATIVE_ENTRY(ClassMirror_name, 1) {
   GET_NON_NULL_NATIVE_ARGUMENT(MirrorReference, ref, arguments->NativeArgAt(0));
-  const Class& klass = Class::Handle(ref.GetClassReferent());
+  const AbstractType& type =
+      AbstractType::Handle(ref.GetAbstractTypeReferent());
+  const Class& klass = Class::Handle(type.type_class());
   return klass.UserVisibleName();
 }
 
 
 DEFINE_NATIVE_ENTRY(ClassMirror_library, 1) {
   GET_NON_NULL_NATIVE_ARGUMENT(MirrorReference, ref, arguments->NativeArgAt(0));
-  const Class& klass = Class::Handle(ref.GetClassReferent());
+  const AbstractType& type =
+      AbstractType::Handle(ref.GetAbstractTypeReferent());
+  const Class& klass = Class::Handle(type.type_class());
   const Library& library = Library::Handle(klass.library());
   // TODO(rmacnak): Revisit when we decide what to do about
   // reflectClass(dynamic).
   if (library.IsNull()) {
     return Instance::null();
   }
   return CreateLibraryMirror(library);
 }
 
 
 DEFINE_NATIVE_ENTRY(ClassMirror_supertype, 1) {
   GET_NON_NULL_NATIVE_ARGUMENT(MirrorReference, ref, arguments->NativeArgAt(0));
-  const Class& klass = Class::Handle(ref.GetClassReferent());
+  const AbstractType& type =
+      AbstractType::Handle(ref.GetAbstractTypeReferent());
+  const Class& klass = Class::Handle(type.type_class());
   return klass.super_type();
 }
 
 
 DEFINE_NATIVE_ENTRY(ClassMirror_interfaces, 1) {
   GET_NON_NULL_NATIVE_ARGUMENT(MirrorReference, ref, arguments->NativeArgAt(0));
-  const Class& klass = Class::Handle(ref.GetClassReferent());
+  const AbstractType& type =
+      AbstractType::Handle(ref.GetAbstractTypeReferent());
+  const Class& klass = Class::Handle(type.type_class());
 
   const Error& error = Error::Handle(klass.EnsureIsFinalized(isolate));
   if (!error.IsNull()) {
     ThrowInvokeError(error);
   }
 
   return klass.interfaces();
 }
 
 
 DEFINE_NATIVE_ENTRY(ClassMirror_members, 2) {
   GET_NON_NULL_NATIVE_ARGUMENT(Instance,
                                owner_mirror,
                                arguments->NativeArgAt(0));
   GET_NON_NULL_NATIVE_ARGUMENT(MirrorReference, ref, arguments->NativeArgAt(1));
-  const Class& klass = Class::Handle(ref.GetClassReferent());
+  const AbstractType& type =
+      AbstractType::Handle(ref.GetAbstractTypeReferent());
+  const Class& klass = Class::Handle(type.type_class());
 
   const Error& error = Error::Handle(klass.EnsureIsFinalized(isolate));
   if (!error.IsNull()) {
     ThrowInvokeError(error);
   }
 
   const Array& fields = Array::Handle(klass.fields());
   // Some special types like 'dynamic' have a null fields list, but they should
   // not wind up as the reflectees of ClassMirrors.
   ASSERT(!fields.IsNull());
@@ skipping 29 matching lines @@
 
   return member_mirrors.raw();
 }
 
 
 DEFINE_NATIVE_ENTRY(ClassMirror_constructors, 2) {
   GET_NON_NULL_NATIVE_ARGUMENT(Instance,
                                owner_mirror,
                                arguments->NativeArgAt(0));
   GET_NON_NULL_NATIVE_ARGUMENT(MirrorReference, ref, arguments->NativeArgAt(1));
-  const Class& klass = Class::Handle(ref.GetClassReferent());
+  const AbstractType& type =
+      AbstractType::Handle(ref.GetAbstractTypeReferent());
+  const Class& klass = Class::Handle(type.type_class());
 
   const Error& error = Error::Handle(klass.EnsureIsFinalized(isolate));
   if (!error.IsNull()) {
     ThrowInvokeError(error);
   }
 
   const Array& functions = Array::Handle(klass.functions());
   // Some special types like 'dynamic' have a null functions list, but they
   // should not wind up as the reflectees of ClassMirrors.
   ASSERT(!functions.IsNull());
@@ skipping 31 matching lines @@
   DictionaryIterator entries(library);
 
   while (entries.HasNext()) {
     entry = entries.GetNext();
     if (entry.IsClass()) {
       const Class& klass = Class::Cast(entry);
       if (!klass.IsCanonicalSignatureClass()) {
         // The various implementations of public classes don't always have the
         // expected superinterfaces or other properties, so we filter them out.
         if (!RawObject::IsImplementationClassId(klass.id())) {
-          member_mirror = CreateClassMirror(klass, owner_mirror);
+          member_mirror = CreateGenericClassMirror(klass, owner_mirror);
           member_mirrors.Add(member_mirror);
         }
       }
     } else if (entry.IsField()) {
       const Field& field = Field::Cast(entry);
       member_mirror = CreateVariableMirror(field, owner_mirror);
       member_mirrors.Add(member_mirror);
     } else if (entry.IsFunction()) {
       const Function& func = Function::Cast(entry);
       if (func.kind() == RawFunction::kRegularFunction ||
           func.kind() == RawFunction::kGetterFunction ||
           func.kind() == RawFunction::kSetterFunction) {
         member_mirror = CreateMethodMirror(func, owner_mirror);
         member_mirrors.Add(member_mirror);
       }
     }
   }
 
   return member_mirrors.raw();
 }
 
 
 DEFINE_NATIVE_ENTRY(ClassMirror_type_variables, 1) {
   GET_NON_NULL_NATIVE_ARGUMENT(MirrorReference, ref, arguments->NativeArgAt(0));
-  const Class& klass = Class::Handle(ref.GetClassReferent());
+  const AbstractType& type =
+      AbstractType::Handle(ref.GetAbstractTypeReferent());
+  const Class& klass = Class::Handle(type.type_class());
   return CreateTypeVariableList(klass);
 }
 
 
+DEFINE_NATIVE_ENTRY(ClassMirror_type_arguments, 1) {
+  GET_NON_NULL_NATIVE_ARGUMENT(MirrorReference, ref, arguments->NativeArgAt(0));
+  AbstractType& type = AbstractType::Handle(ref.GetAbstractTypeReferent());
+
+  const AbstractTypeArguments& args =
+      AbstractTypeArguments::Handle(type.arguments());
+  if (args.IsNull()) {
+    return Object::empty_array().raw();
+  }
+
+  const Array& result = Array::Handle(Array::New(args.Length()));
+  Instance& type_mirror = Instance::Handle();
+  for (intptr_t i = 0; i < args.Length(); i++) {
+    type ^= args.TypeAt(i);
+    type_mirror = CreateTypeMirror(type);
+    result.SetAt(i, type_mirror);
+  }
+  return result.raw();
+}
+
+
 DEFINE_NATIVE_ENTRY(LocalTypeVariableMirror_owner, 1) {
   GET_NON_NULL_NATIVE_ARGUMENT(TypeParameter, param, arguments->NativeArgAt(0));
-  return CreateClassMirror(Class::Handle(param.parameterized_class()),
+  return CreateGenericClassMirror(Class::Handle(param.parameterized_class()),
                            Instance::null_instance());
 }
 
 
 DEFINE_NATIVE_ENTRY(LocalTypeVariableMirror_upper_bound, 1) {
   GET_NON_NULL_NATIVE_ARGUMENT(TypeParameter, param, arguments->NativeArgAt(0));
   return CreateTypeMirror(AbstractType::Handle(param.bound()));
 }
 
 
@@ skipping 211 matching lines @@
   Exceptions::ThrowByType(Exceptions::kNoSuchMethod, args);
   UNREACHABLE();
 }
 
 
 static void ThrowNoSuchMethod(const Class& klass,
                               const String& function_name,
                               const Function& function,
                               const InvocationMirror::Call call,
                               const InvocationMirror::Type type) {
-  AbstractTypeArguments& type_arguments = AbstractTypeArguments::Handle();
-  Type& pre_type = Type::Handle(
-      Type::New(klass, type_arguments, Scanner::kDummyTokenIndex));
-  pre_type.SetIsFinalized();
-  AbstractType& runtime_type = AbstractType::Handle(pre_type.Canonicalize());
+  AbstractType& runtime_type = AbstractType::Handle(RawTypeOfClass(klass));
 
   ThrowNoSuchMethod(runtime_type,
                     function_name,
                     function,
                     call,
                     type);
   UNREACHABLE();
 }
 
 
 static void ThrowNoSuchMethod(const Library& library,
                               const String& function_name,
                               const Function& function,
                               const InvocationMirror::Call call,
                               const InvocationMirror::Type type) {
   ThrowNoSuchMethod(Instance::null_instance(),
                     function_name,
                     function,
                     call,
                     type);
   UNREACHABLE();
 }
 
 
 DEFINE_NATIVE_ENTRY(ClassMirror_invoke, 4) {
   // Argument 0 is the mirror, which is unused by the native. It exists
   // because this native is an instance method in order to be polymorphic
   // with its cousins.
   GET_NON_NULL_NATIVE_ARGUMENT(MirrorReference, ref, arguments->NativeArgAt(1));
-  const Class& klass = Class::Handle(ref.GetClassReferent());
+  const AbstractType& type =
+      AbstractType::Handle(ref.GetAbstractTypeReferent());
+  const Class& klass = Class::Handle(type.type_class());
   GET_NON_NULL_NATIVE_ARGUMENT(
       String, function_name, arguments->NativeArgAt(2));
   GET_NON_NULL_NATIVE_ARGUMENT(
       Array, positional_args, arguments->NativeArgAt(3));
 
   intptr_t number_of_arguments = positional_args.Length();
 
   const Function& function = Function::Handle(
       klass.LookupStaticFunctionAllowPrivate(function_name));
 
@@ skipping 17 matching lines @@
   }
   return result.raw();
 }
 
 
 DEFINE_NATIVE_ENTRY(ClassMirror_invokeGetter, 3) {
   // Argument 0 is the mirror, which is unused by the native. It exists
   // because this native is an instance method in order to be polymorphic
   // with its cousins.
   GET_NON_NULL_NATIVE_ARGUMENT(MirrorReference, ref, arguments->NativeArgAt(1));
-  const Class& klass = Class::Handle(ref.GetClassReferent());
+  const AbstractType& type =
+      AbstractType::Handle(ref.GetAbstractTypeReferent());
+  const Class& klass = Class::Handle(type.type_class());
   GET_NON_NULL_NATIVE_ARGUMENT(String, getter_name, arguments->NativeArgAt(2));
 
   // Note static fields do not have implicit getters.
   const Field& field = Field::Handle(klass.LookupStaticField(getter_name));
   if (field.IsNull() || FieldIsUninitialized(field)) {
     const String& internal_getter_name = String::Handle(
         Field::GetterName(getter_name));
     const Function& getter = Function::Handle(
         klass.LookupStaticFunctionAllowPrivate(internal_getter_name));
 
@@ skipping 17 matching lines @@
   }
   return field.value();
 }
 
 
 DEFINE_NATIVE_ENTRY(ClassMirror_invokeSetter, 4) {
   // Argument 0 is the mirror, which is unused by the native. It exists
   // because this native is an instance method in order to be polymorphic
   // with its cousins.
   GET_NON_NULL_NATIVE_ARGUMENT(MirrorReference, ref, arguments->NativeArgAt(1));
-  const Class& klass = Class::Handle(ref.GetClassReferent());
+  const AbstractType& type =
+      AbstractType::Handle(ref.GetAbstractTypeReferent());
+  const Class& klass = Class::Handle(type.type_class());
   GET_NON_NULL_NATIVE_ARGUMENT(String, setter_name, arguments->NativeArgAt(2));
   GET_NATIVE_ARGUMENT(Instance, value, arguments->NativeArgAt(3));
 
   // Check for real fields and user-defined setters.
   const Field& field = Field::Handle(klass.LookupStaticField(setter_name));
   if (field.IsNull()) {
     const String& internal_setter_name = String::Handle(
       Field::SetterName(setter_name));
     const Function& setter = Function::Handle(
       klass.LookupStaticFunctionAllowPrivate(internal_setter_name));
@@ skipping 30 matching lines @@
     UNREACHABLE();
   }
 
   field.set_value(value);
   return value.raw();
 }
 
 
 DEFINE_NATIVE_ENTRY(ClassMirror_invokeConstructor, 3) {
   GET_NON_NULL_NATIVE_ARGUMENT(MirrorReference, ref, arguments->NativeArgAt(0));
-  const Class& klass = Class::Handle(ref.GetClassReferent());
+  const AbstractType& type =
+      AbstractType::Handle(ref.GetAbstractTypeReferent());
+  const Class& klass = Class::Handle(type.type_class());
   GET_NON_NULL_NATIVE_ARGUMENT(
       String, constructor_name, arguments->NativeArgAt(1));
   GET_NON_NULL_NATIVE_ARGUMENT(
       Array, positional_args, arguments->NativeArgAt(2));
 
   intptr_t number_of_arguments = positional_args.Length();
 
   // By convention, the static function implementing a named constructor 'C'
   // for class 'A' is labeled 'A.C', and the static function implementing the
   // unnamed constructor for class 'A' is labeled 'A.'.
@@ skipping 195 matching lines @@
                            setter_name.ToCString()));
     ThrowMirroredCompilationError(message);
     UNREACHABLE();
   }
 
   field.set_value(value);
   return value.raw();
 }
 
 
+
 DEFINE_NATIVE_ENTRY(MethodMirror_owner, 1) {
   GET_NON_NULL_NATIVE_ARGUMENT(MirrorReference, ref, arguments->NativeArgAt(0));
   const Function& func = Function::Handle(ref.GetFunctionReferent());
   if (func.IsNonImplicitClosureFunction()) {
     return CreateMethodMirror(Function::Handle(
         func.parent_function()), Object::null_instance());
   }
   const Class& owner = Class::Handle(func.Owner());
   if (owner.IsTopLevel()) {
     return CreateLibraryMirror(Library::Handle(owner.library()));
   }
-  return CreateClassMirror(owner, Object::null_instance());
+  return CreateGenericClassMirror(owner, Object::null_instance());
 }
 
 
 DEFINE_NATIVE_ENTRY(MethodMirror_parameters, 1) {
   GET_NON_NULL_NATIVE_ARGUMENT(MirrorReference, ref, arguments->NativeArgAt(0));
   const Function& func = Function::Handle(ref.GetFunctionReferent());
   return CreateParameterMirrorList(func);
 }
 
 
 DEFINE_NATIVE_ENTRY(MethodMirror_return_type, 1) {
   GET_NON_NULL_NATIVE_ARGUMENT(MirrorReference, ref, arguments->NativeArgAt(0));
   const Function& func = Function::Handle(ref.GetFunctionReferent());
   // We handle constructors in Dart code.
   ASSERT(!func.IsConstructor());
   const AbstractType& return_type = AbstractType::Handle(func.result_type());
   return CreateTypeMirror(return_type);
 }
 
 
 DEFINE_NATIVE_ENTRY(TypedefMirror_referent, 1) {
   GET_NON_NULL_NATIVE_ARGUMENT(MirrorReference, ref, arguments->NativeArgAt(0));
-  const Class& cls = Class::Handle(ref.GetClassReferent());
+  const AbstractType& type =
+      AbstractType::Handle(ref.GetAbstractTypeReferent());
+  const Class& cls = Class::Handle(type.type_class());
   const Function& sig_func = Function::Handle(cls.signature_function());
   const Class& sig_cls = Class::Handle(sig_func.signature_class());
-  return MirrorReference::New(sig_cls);
+
+  // Possibly losing information here....
+  AbstractType& runtime_type = AbstractType::Handle(RawTypeOfClass(sig_cls));
+
+  return MirrorReference::New(runtime_type);
 }
 
 
 DEFINE_NATIVE_ENTRY(ParameterMirror_type, 2) {
   GET_NON_NULL_NATIVE_ARGUMENT(MirrorReference, ref, arguments->NativeArgAt(0));
   GET_NON_NULL_NATIVE_ARGUMENT(Smi, pos, arguments->NativeArgAt(1));
   const Function& func = Function::Handle(ref.GetFunctionReferent());
   const AbstractType& param_type = AbstractType::Handle(func.ParameterTypeAt(
       func.NumImplicitParameters() + pos.Value()));
   return CreateTypeMirror(param_type);
 }
 
 
 DEFINE_NATIVE_ENTRY(VariableMirror_type, 1) {
   GET_NON_NULL_NATIVE_ARGUMENT(MirrorReference, ref, arguments->NativeArgAt(0));
   const Field& field = Field::Handle(ref.GetFieldReferent());
 
   const AbstractType& type = AbstractType::Handle(field.type());
   return CreateTypeMirror(type);
 }
 
 }  // namespace dart