Adds a special case for sending an int over a port with the native API.

runtime/vm/native_message_handler.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 "vm/native_message_handler.h"
 
 #include "vm/dart_api_message.h"
 #include "vm/isolate.h"
 #include "vm/message.h"
 #include "vm/snapshot.h"
@@ skipping 20 matching lines @@
 }
 #endif
 
 
 MessageHandler::MessageStatus NativeMessageHandler::HandleMessage(
     Message* message) {
   if (message->IsOOB()) {
     // We currently do not use OOB messages for native ports.
     UNREACHABLE();
   }
+  ASSERT(message->len() > 0);

[Ivan Posva, 2015/12/09 22:45:28]

You cannot assert this. The poster of the message on the other side is free to
use the shortcut without knowing who the recipient is.

[zra, 2015/12/10 00:07:29]

I'm not sure I see a good way to convert a RawObject to a Dart_CObject, here. I
could try to serialize the RawObject as if it had been posted by Dart_Post, but
the problem there is that the NativeMessageHandlers run on a thread that doesn't
have an Isolate or Thread, which the SnapshotWriter assumes exists.

Thoughts?

[zra, 2015/12/10 20:51:33]

I've added some code to this CL to handle RawObject -> CObject conversion of
Smis and Null. I put it in //runtime/vm/dart_api_message.h. PTAL.

   // We create a native scope for handling the message.
   // All allocation of objects for decoding the message is done in the
   // zone associated with this scope.
   ApiNativeScope scope;
   ApiMessageReader reader(message->data(), message->len());
   Dart_CObject* object = reader.ReadMessage();
   (*func())(message->dest_port(), object);
   delete message;
   return kOK;
 }
 
 }  // namespace dart