- Add following additional methods to the API to make returning values

runtime/vm/dart_api_impl.cc

 // Copyright (c) 2013, 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 "include/dart_api.h"
 #include "include/dart_mirrors_api.h"
 #include "include/dart_native_api.h"
 
 #include "platform/assert.h"
 #include "vm/bigint_operations.h"
@@ skipping 3547 matching lines @@
 DART_EXPORT Dart_Handle Dart_GetNativeFieldOfArgument(Dart_NativeArguments args,
                                                       int arg_index,
                                                       int fld_index,
                                                       intptr_t* value) {
   NativeArguments* arguments = reinterpret_cast<NativeArguments*>(args);
   if ((arg_index < 0) || (arg_index >= arguments->NativeArgCount())) {
     return Api::NewError(
         "%s: argument 'arg_index' out of range. Expected 0..%d but saw %d.",
         CURRENT_FUNC, arguments->NativeArgCount() - 1, arg_index);
   }
-  Isolate* isolate = Isolate::Current();
+  Isolate* isolate = arguments->isolate();
   DARTSCOPE(isolate);
   const Object& obj = Object::Handle(isolate,
                                      arguments->NativeArgAt(arg_index));
   if (!obj.IsInstance()) {
     return Api::NewError("%s expects argument at index '%d' to be of"
                          " type Instance.", CURRENT_FUNC, arg_index);
   }
   if (obj.IsNull()) {
     return Api::NewError("%s expects argument at index '%d' to be non-null.",
                          CURRENT_FUNC, arg_index);
   }
   const Instance& instance = Instance::Cast(obj);
   if (!instance.IsValidNativeIndex(fld_index)) {
     return Api::NewError(
         "%s: invalid index %d passed in to access native instance field",
         CURRENT_FUNC, fld_index);
   }
   if (value == NULL) {
     RETURN_NULL_ERROR(value);
   }
   *value = instance.GetNativeField(isolate, fld_index);
   return Api::Success();
 }
 
 
 DART_EXPORT void Dart_SetReturnValue(Dart_NativeArguments args,
                                      Dart_Handle retval) {
-  const Object& ret_obj = Object::Handle(Api::UnwrapHandle(retval));
-  if (!ret_obj.IsNull() && !ret_obj.IsInstance()) {
+  NativeArguments* arguments = reinterpret_cast<NativeArguments*>(args);
+  Isolate* isolate = arguments->isolate();
+  CHECK_ISOLATE(isolate);
+  if ((retval != Api::Null()) && (!Api::IsInstance(retval))) {
+    const Object& ret_obj = Object::Handle(Api::UnwrapHandle(retval));
     FATAL1("Return value check failed: saw '%s' expected a dart Instance.",
            ret_obj.ToCString());
   }
-  NoGCScope no_gc_scope;
+  Api::SetReturnValue(arguments, retval);
+}
+
+
+DART_EXPORT void Dart_SetBooleanReturnValue(Dart_NativeArguments args,
+                                            bool retval) {
   NativeArguments* arguments = reinterpret_cast<NativeArguments*>(args);
-  arguments->SetReturn(ret_obj);
+  arguments->SetReturn(retval ? Bool::True() : Bool::False());
+}
+
+
+DART_EXPORT void Dart_SetIntegerReturnValue(Dart_NativeArguments args,
+                                            intptr_t retval) {
+  NativeArguments* arguments = reinterpret_cast<NativeArguments*>(args);
+  Isolate* isolate = arguments->isolate();
+  CHECK_ISOLATE(isolate);
+  if (Smi::IsValid64(retval)) {
+    Api::SetSmiReturnValue(arguments, retval);
+  } else {
+    // Slow path for Mints and Bigints.
+    ASSERT_CALLBACK_STATE(isolate);
+    Api::SetIntegerReturnValue(arguments, retval);
+  }
+}
+
+
+DART_EXPORT void Dart_SetDoubleReturnValue(Dart_NativeArguments args,
+                                           double retval) {
+  NativeArguments* arguments = reinterpret_cast<NativeArguments*>(args);
+  Isolate* isolate = arguments->isolate();
+  CHECK_ISOLATE(isolate);
+  ASSERT_CALLBACK_STATE(isolate);
+  Api::SetDoubleReturnValue(arguments, retval);
 }
 
 
 // --- Scripts and Libraries ---
 
 DART_EXPORT Dart_Handle Dart_SetLibraryTagHandler(
     Dart_LibraryTagHandler handler) {
   Isolate* isolate = Isolate::Current();
   CHECK_ISOLATE(isolate);
   isolate->set_library_tag_handler(handler);
@@ skipping 461 matching lines @@
   }
   {
     NoGCScope no_gc;
     RawObject* raw_obj = obj.raw();
     isolate->heap()->SetPeer(raw_obj, peer);
   }
   return Api::Success();
 }
 
 }  // namespace dart