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

vm/stub_code_x64_test.cc

 // Copyright (c) 2011, 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/globals.h"
 #if defined(TARGET_ARCH_X64)
 
 #include "vm/isolate.h"
 #include "vm/dart_entry.h"
 #include "vm/native_entry.h"
@@ skipping 102 matching lines @@
 }
 
 
 // Test calls to stub code which calls a native C function.
 static void GenerateCallToCallNativeCFunctionStub(Assembler* assembler,
                                                   int value1, int value2) {
   const int argc = 2;
   const Smi& smi1 = Smi::ZoneHandle(Smi::New(value1));
   const Smi& smi2 = Smi::ZoneHandle(Smi::New(value2));
   const Object& result = Object::ZoneHandle();
-  const String& native_name = String::ZoneHandle(String::New("TestSmiSub"));
-  Dart_NativeFunction native_function =
-      NativeTestEntry_Lookup(native_name, argc);
+  Dart_NativeFunction native_function = TestSmiSub;
   ASSERT(native_function != NULL);
   const Context& context = Context::ZoneHandle(Context::New(0, Heap::kOld));
   ASSERT(context.isolate() == Isolate::Current());
   __ enter(Immediate(0));
   __ LoadObject(CTX, context);
   __ PushObject(smi1);  // Push argument 1 smi1.
   __ PushObject(smi2);  // Push argument 2 smi2.
   __ PushObject(result);  // Push Null object for return value.
   // Pass a pointer to the first argument in RAX.
   __ leaq(RAX, Address(RSP, 2 * kWordSize));
@@ skipping 21 matching lines @@
   GrowableArray<const Object*>  arguments;
   const Array& kNoArgumentNames = Array::Handle();
   Smi& result = Smi::Handle();
   result ^= DartEntry::InvokeStatic(function, arguments, kNoArgumentNames);
   EXPECT_EQ((value1 - value2), result.Value());
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_X64