Create read only handles for empty_array and sentinel objects

vm/dart_api_impl.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 "include/dart_api.h"
 
 #include "vm/bigint_operations.h"
 #include "vm/class_finalizer.h"
 #include "vm/compiler.h"
 #include "vm/dart.h"
@@ skipping 3559 matching lines @@
 }
 
 
 static bool FieldIsUninitialized(Isolate* isolate, const Field& fld) {
   ASSERT(!fld.IsNull());
 
   // Return getter method for uninitialized fields, rather than the
   // field object, since the value in the field object will not be
   // initialized until the first time the getter is invoked.
   const Instance& value = Instance::Handle(isolate, fld.value());
-  ASSERT(value.raw() != Object::transition_sentinel());
-  return value.raw() == Object::sentinel();
+  ASSERT(value.raw() != Object::transition_sentinel().raw());
+  return value.raw() == Object::sentinel().raw();
 }
 
 
 DART_EXPORT Dart_Handle Dart_GetField(Dart_Handle container, Dart_Handle name) {
   Isolate* isolate = Isolate::Current();
   DARTSCOPE(isolate);
 
   const String& field_name = Api::UnwrapStringHandle(isolate, name);
   if (field_name.IsNull()) {
     RETURN_TYPE_ERROR(isolate, name, String);
@@ skipping 44 matching lines @@
     const Class& cls = Class::Cast(obj);
     field = cls.LookupStaticField(field_name);
     if (field.IsNull() || FieldIsUninitialized(isolate, field)) {
       const String& getter_name =
           String::Handle(isolate, Field::GetterName(field_name));
       getter = cls.LookupStaticFunction(getter_name);
     }
 
     if (!getter.IsNull()) {
       // Invoke the getter and return the result.
-      const Array& args = Array::Handle(isolate, Object::empty_array());
-      return Api::NewHandle(isolate, DartEntry::InvokeStatic(getter, args));
+      return Api::NewHandle(
+          isolate, DartEntry::InvokeStatic(getter, Object::empty_array()));
     } else if (!field.IsNull()) {
       return Api::NewHandle(isolate, field.value());
     } else {
       return Api::NewError("%s: did not find static field '%s'.",
                            CURRENT_FUNC, field_name.ToCString());
     }
 
   } else if (obj.IsLibrary()) {
     // TODO(turnidge): Do we need to call CheckIsolateState here?
 
@@ skipping 10 matching lines @@
     } else if (FieldIsUninitialized(isolate, field)) {
       // A field was found.  Check for a getter in the field's owner classs.
       const Class& cls = Class::Handle(isolate, field.owner());
       const String& getter_name =
           String::Handle(isolate, Field::GetterName(field_name));
       getter = cls.LookupStaticFunction(getter_name);
     }
 
     if (!getter.IsNull()) {
       // Invoke the getter and return the result.
-      const Array& args = Array::Handle(isolate, Object::empty_array());
-      return Api::NewHandle(isolate, DartEntry::InvokeStatic(getter, args));
+      return Api::NewHandle(
+          isolate, DartEntry::InvokeStatic(getter, Object::empty_array()));
     } else if (!field.IsNull()) {
       return Api::NewHandle(isolate, field.value());
     } else {
       return Api::NewError("%s: did not find top-level variable '%s'.",
                            CURRENT_FUNC, field_name.ToCString());
     }
 
   } else if (obj.IsError()) {
       return container;
   } else {
@@ skipping 806 matching lines @@
   }
   {
     NoGCScope no_gc;
     RawObject* raw_obj = obj.raw();
     isolate->heap()->SetPeer(raw_obj, peer);
   }
   return Api::Success(isolate);
 }
 
 }  // namespace dart