Revert of [handles] Sanitize Handle and friends.

src/handles-inl.h

Index: src/handles-inl.h
diff --git a/src/handles-inl.h b/src/handles-inl.h
index b905c16a04f4e1f33342243aef9a77c01a268b2c..3022f288a3919230c955c01c90d5773d731fac6d 100644
--- a/src/handles-inl.h
+++ b/src/handles-inl.h
@@ -1,6 +1,7 @@
 // Copyright 2006-2008 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
+//
 
 #ifndef V8_HANDLES_INL_H_
 #define V8_HANDLES_INL_H_
@@ -13,8 +14,72 @@
 namespace v8 {
 namespace internal {
 
-HandleBase::HandleBase(Object* object, Isolate* isolate)
-    : location_(HandleScope::CreateHandle(isolate, object)) {}
+template<typename T>
+Handle<T>::Handle(T* obj) {
+  location_ = HandleScope::CreateHandle(obj->GetIsolate(), obj);
+}
+
+
+template<typename T>
+Handle<T>::Handle(T* obj, Isolate* isolate) {
+  location_ = HandleScope::CreateHandle(isolate, obj);
+}
+
+
+template <typename T>
+inline bool Handle<T>::is_identical_to(const Handle<T> o) const {
+  // Dereferencing deferred handles to check object equality is safe.
+  SLOW_DCHECK(
+      (location_ == NULL || IsDereferenceAllowed(NO_DEFERRED_CHECK)) &&
+      (o.location_ == NULL || o.IsDereferenceAllowed(NO_DEFERRED_CHECK)));
+  if (location_ == o.location_) return true;
+  if (location_ == NULL || o.location_ == NULL) return false;
+  return *location_ == *o.location_;
+}
+
+
+template <typename T>
+inline T* Handle<T>::operator*() const {
+  SLOW_DCHECK(IsDereferenceAllowed(INCLUDE_DEFERRED_CHECK));
+  return *bit_cast<T**>(location_);
+}
+
+template <typename T>
+inline T** Handle<T>::location() const {
+  SLOW_DCHECK(location_ == NULL ||
+              IsDereferenceAllowed(INCLUDE_DEFERRED_CHECK));
+  return location_;
+}
+
+#ifdef DEBUG
+template <typename T>
+bool Handle<T>::IsDereferenceAllowed(DereferenceCheckMode mode) const {
+  DCHECK(location_ != NULL);
+  Object* object = *bit_cast<T**>(location_);
+  if (object->IsSmi()) return true;
+  HeapObject* heap_object = HeapObject::cast(object);
+  Heap* heap = heap_object->GetHeap();
+  Object** handle = reinterpret_cast<Object**>(location_);
+  Object** roots_array_start = heap->roots_array_start();
+  if (roots_array_start <= handle &&
+      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 cells, maps and internalized strings is safe.
+    if (heap_object->IsCell()) return true;
+    if (heap_object->IsMap()) return true;
+    if (heap_object->IsInternalizedString()) return true;
+    return !heap->isolate()->IsDeferredHandle(handle);
+  }
+  return true;
+}
+#endif
+
 
 
 HandleScope::HandleScope(Isolate* isolate) {
@@ -71,7 +136,7 @@
   CloseScope(isolate_, prev_next_, prev_limit_);
   // Allocate one handle in the parent scope.
   DCHECK(current->level > 0);
-  Handle<T> result(value, isolate_);
+  Handle<T> result(CreateHandle<T>(isolate_, value));
   // Reinitialize the current scope (so that it's ready
   // to be used or closed again).
   prev_next_ = current->next;
@@ -86,7 +151,7 @@
   DCHECK(AllowHandleAllocation::IsAllowed());
   HandleScopeData* current = isolate->handle_scope_data();
 
-  Object** cur = current->next;
+  internal::Object** cur = current->next;
   if (cur == current->limit) cur = Extend(isolate);
   // Update the current next field, set the value in the created
   // handle, and return the result.
@@ -125,7 +190,6 @@
 
 #endif
 
-}  // namespace internal
-}  // namespace v8
+} }  // namespace v8::internal
 
 #endif  // V8_HANDLES_INL_H_