Make handle dereference check more precise.

src/handles-inl.h

 // Copyright 2006-2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 14 matching lines @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 //
 
 #ifndef V8_HANDLES_INL_H_
 #define V8_HANDLES_INL_H_
 
 #include "api.h"
 #include "apiutils.h"
 #include "handles.h"
+#include "heap.h"
 #include "isolate.h"
 
 namespace v8 {
 namespace internal {
 
 template<typename T>
 Handle<T>::Handle(T* obj) {
   ASSERT(!obj->IsFailure());
   location_ = HandleScope::CreateHandle(obj->GetIsolate(), obj);
 }
@@ skipping 33 matching lines @@
   return location_;
 }
 
 #ifdef DEBUG
 template <typename T>
 bool Handle<T>::IsDereferenceAllowed(DereferenceCheckMode mode) const {
   ASSERT(location_ != NULL);
   Object* object = *BitCast<T**>(location_);
   if (object->IsSmi()) return true;
   HeapObject* heap_object = HeapObject::cast(object);
-  Isolate* isolate = heap_object->GetIsolate();
+  Heap* heap = heap_object->GetHeap();
   Object** handle = reinterpret_cast<Object**>(location_);
-  Object** roots_array_start = isolate->heap()->roots_array_start();
+  Object** roots_array_start = heap->roots_array_start();
   if (roots_array_start <= handle &&
-      handle < roots_array_start + Heap::kStrongRootListLength) {
+      handle < roots_array_start + Heap::kStrongRootListLength &&
+      heap->RootCanBeTreatedAsConstant(
+        static_cast<Heap::RootListIndex>(handle - roots_array_start))) {
     return true;
   }
   if (!AllowHandleDereference::IsAllowed()) return false;
   if (mode == INCLUDE_DEFERRED_CHECK &&
       !AllowDeferredHandleDereference::IsAllowed()) {
     // Accessing maps and internalized strings is safe.
     if (heap_object->IsMap()) return true;
     if (heap_object->IsInternalizedString()) return true;
-    return !isolate->IsDeferredHandle(handle);
+    return !heap->isolate()->IsDeferredHandle(handle);
   }
   return true;
 }
 #endif
 
 
 
 HandleScope::HandleScope(Isolate* isolate) {
   v8::ImplementationUtilities::HandleScopeData* current =
       isolate->handle_scope_data();
@@ skipping 91 matching lines @@
   current->level = level_;
   ASSERT_EQ(current->next, current->limit);
   current->limit = limit_;
 }
 
 #endif
 
 } }  // namespace v8::internal
 
 #endif  // V8_HANDLES_INL_H_