Use the return value of vm native methods to set the return value,

lib/isolate.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 "platform/assert.h"
 #include "vm/bootstrap_natives.h"
 #include "vm/class_finalizer.h"
 #include "vm/dart.h"
 #include "vm/dart_api_impl.h"
 #include "vm/dart_entry.h"
@@ skipping 102 matching lines @@
 
 
 DEFINE_NATIVE_ENTRY(ReceivePortImpl_factory, 1) {
   ASSERT(AbstractTypeArguments::CheckedHandle(arguments->At(0)).IsNull());
   intptr_t port_id =
       PortMap::CreatePort(arguments->isolate()->message_handler());
   const Object& port = Object::Handle(ReceivePortCreate(port_id));
   if (port.IsError()) {
     Exceptions::PropagateError(Error::Cast(port));
   }
-  arguments->SetReturn(port);
+  return port.raw();
 }
 
 
 DEFINE_NATIVE_ENTRY(ReceivePortImpl_closeInternal, 1) {
   GET_NATIVE_ARGUMENT(Smi, id, arguments->At(0));
   PortMap::ClosePort(id.Value());
+  return Object::null();
 }
 
 
 DEFINE_NATIVE_ENTRY(SendPortImpl_sendInternal_, 3) {
   GET_NATIVE_ARGUMENT(Smi, send_id, arguments->At(0));
   GET_NATIVE_ARGUMENT(Smi, reply_id, arguments->At(1));
   // TODO(iposva): Allow for arbitrary messages to be sent.
   GET_NATIVE_ARGUMENT(Instance, obj, arguments->At(2));
 
   uint8_t* data = NULL;
   MessageWriter writer(&data, &allocator);
   writer.WriteMessage(obj);
 
   // TODO(turnidge): Throw an exception when the return value is false?
   PortMap::PostMessage(new Message(send_id.Value(), reply_id.Value(),
                                    data, writer.BytesWritten(),
                                    Message::kNormalPriority));
+  return Object::null();
 }
 
 
 static void ThrowIllegalArgException(const String& message) {
   GrowableArray<const Object*> args(1);
   args.Add(&message);
   Exceptions::ThrowByType(Exceptions::kIllegalArgument, args);
 }
 
 
@@ skipping 202 matching lines @@
     result = DartEntry::InvokeStatic(func, args, kNoArgNames);
     if (result.IsError()) {
       StoreError(isolate, result);
       return false;
     }
   }
   return true;
 }
 
 
-static void Spawn(NativeArguments* arguments, SpawnState* state) {
+static RawObject* Spawn(NativeArguments* arguments, SpawnState* state) {
   // Create a new isolate.
   char* error = NULL;
   if (!CreateIsolate(state, &error)) {
     delete state;
     const String& msg = String::Handle(String::New(error));
     free(error);
     ThrowIsolateSpawnException(msg);
   }
 
   // Try to create a SendPort for the new isolate.
   const Object& port = Object::Handle(
       DartLibraryCalls::NewSendPort(state->isolate()->main_port()));
   if (port.IsError()) {
     state->Cleanup();
     delete state;
     Exceptions::PropagateError(Error::Cast(port));
   }
 
   // Start the new isolate.
   state->isolate()->set_spawn_data(reinterpret_cast<uword>(state));
   state->isolate()->message_handler()->Run(
       Dart::thread_pool(), RunIsolate, ShutdownIsolate,
       reinterpret_cast<uword>(state->isolate()));
 
-  arguments->SetReturn(port);
+  return port.raw();
 }
 
 
 DEFINE_NATIVE_ENTRY(isolate_spawnFunction, 1) {
   GET_NATIVE_ARGUMENT(Closure, closure, arguments->At(0));
   const Function& func = Function::Handle(closure.function());
   const Class& cls = Class::Handle(func.Owner());
   if (!func.IsClosureFunction() || !func.is_static() || !cls.IsTopLevel()) {
     const String& msg = String::Handle(String::New(
         "spawnFunction expects to be passed a closure to a top-level static "
         "function"));
     ThrowIllegalArgException(msg);
   }
 
 #if defined(DEBUG)
   const Context& ctx = Context::Handle(closure.context());
   ASSERT(ctx.num_variables() == 0);
 #endif
 
-  Spawn(arguments, new SpawnState(func));
+  return Spawn(arguments, new SpawnState(func));
 }
 
 
 DEFINE_NATIVE_ENTRY(isolate_spawnUri, 1) {
   GET_NATIVE_ARGUMENT(String, uri, arguments->At(0));
 
   // Canonicalize the uri with respect to the current isolate.
   char* error = NULL;
   char* canonical_uri = NULL;
   const Library& root_lib =
       Library::Handle(arguments->isolate()->object_store()->root_library());
   if (!CanonicalizeUri(arguments->isolate(), root_lib, uri,
                        &canonical_uri, &error)) {
     const String& msg = String::Handle(String::New(error));
     free(error);
     ThrowIsolateSpawnException(msg);
   }
 
-  Spawn(arguments, new SpawnState(canonical_uri));
+  return Spawn(arguments, new SpawnState(canonical_uri));
 }
 
 
 DEFINE_NATIVE_ENTRY(isolate_getPortInternal, 0) {
   const Object& port = Object::Handle(ReceivePortCreate(isolate->main_port()));
   if (port.IsError()) {
     Exceptions::PropagateError(Error::Cast(port));
   }
-  arguments->SetReturn(port);
+  return port.raw();
 }
 
 }  // namespace dart