Enumerate URIs of all types in type errors in order to help the user diagnose

runtime/lib/object.cc

Index: runtime/lib/object.cc
diff --git a/runtime/lib/object.cc b/runtime/lib/object.cc
index 09e4808ba15c1ff9fe06776d455ef08186363190..85f1d27f6dd3d3d735e7553d4c90ebe8432a8a6b 100644
--- a/runtime/lib/object.cc
+++ b/runtime/lib/object.cc
@@ -155,7 +155,7 @@ DEFINE_NATIVE_ENTRY(Object_instanceOf, 4) {
     String& bound_error_message = String::Handle(
         zone, String::New(bound_error.ToErrorCString()));
     Exceptions::CreateAndThrowTypeError(
-        location, Symbols::Empty(), Symbols::Empty(),
+        location, AbstractType::Handle(), AbstractType::Handle(),

[srdjan, 2016/03/09 22:38:22]

AbstractType::Handle(zone) x 2

[regis, 2016/03/09 23:15:40]

Done here and above.

         Symbols::Empty(), bound_error_message);
     UNREACHABLE();
   }
@@ -227,8 +227,7 @@ DEFINE_NATIVE_ENTRY(Object_as, 3) {
   const Instance& instance = Instance::CheckedHandle(arguments->NativeArgAt(0));
   const TypeArguments& instantiator_type_arguments =
       TypeArguments::CheckedHandle(arguments->NativeArgAt(1));
-  const AbstractType& type =
-      AbstractType::CheckedHandle(arguments->NativeArgAt(2));
+  AbstractType& type = AbstractType::CheckedHandle(arguments->NativeArgAt(2));
   ASSERT(type.IsFinalized());
   ASSERT(!type.IsMalformed());
   ASSERT(!type.IsMalbounded());
@@ -258,32 +257,22 @@ DEFINE_NATIVE_ENTRY(Object_as, 3) {
     const TokenPosition location = caller_frame->GetTokenPos();
     const AbstractType& instance_type =
         AbstractType::Handle(instance.GetType());
-    const String& instance_type_name =
-        String::Handle(instance_type.UserVisibleName());
-    String& type_name = String::Handle();
     if (!type.IsInstantiated()) {
       // Instantiate type before reporting the error.
-      const AbstractType& instantiated_type = AbstractType::Handle(
-          type.InstantiateFrom(instantiator_type_arguments, NULL,
-                               NULL, NULL, Heap::kNew));
-      // Note that instantiated_type may be malformed.
-      type_name = instantiated_type.UserVisibleName();
-    } else {
-      type_name = type.UserVisibleName();
+      type = type.InstantiateFrom(instantiator_type_arguments, NULL,
+                                  NULL, NULL, Heap::kNew);
+      // Note that the instantiated type may be malformed.
     }
-    String& bound_error_message =  String::Handle();
     if (bound_error.IsNull()) {
-      const String& dst_name = String::ZoneHandle(
-          Symbols::New(Exceptions::kCastErrorDstName));
-
       Exceptions::CreateAndThrowTypeError(
-          location, instance_type_name, type_name,
-          dst_name, Object::null_string());
+          location, instance_type, type,
+          Symbols::InTypeCast(), Object::null_string());
     } else {
       ASSERT(isolate->type_checks());
-      bound_error_message = String::New(bound_error.ToErrorCString());
+      const String& bound_error_message =
+          String::Handle(String::New(bound_error.ToErrorCString()));

[srdjan, 2016/03/09 22:38:22]

zone, 

[regis, 2016/03/09 23:15:40]

Done.

       Exceptions::CreateAndThrowTypeError(
-          location, instance_type_name, Symbols::Empty(),
+          location, instance_type, AbstractType::Handle(),

[srdjan, 2016/03/09 22:38:22]

zone

[regis, 2016/03/09 23:15:40]

Done.

           Symbols::Empty(), bound_error_message);
     }
     UNREACHABLE();