Revert changes 601 and 602. TBR

src/objects.cc

Index: src/objects.cc
===================================================================
--- src/objects.cc	(revision 602)
+++ src/objects.cc	(working copy)
@@ -333,7 +333,7 @@
       // Check if we're allowed to read from the current object. Note
       // that even though we may not actually end up loading the named
       // property from the current object, we still check that we have
-      // access to it.
+      // access to the it.
       JSObject* checked = JSObject::cast(current);
       if (!Top::MayNamedAccess(checked, name, v8::ACCESS_GET)) {
         return checked->GetPropertyWithFailedAccessCheck(receiver,
@@ -4050,67 +4050,6 @@
 }
 
 
-void Map::CreateBackPointers() {
-  DescriptorArray* descriptors = instance_descriptors();
-  for (DescriptorReader r(descriptors); !r.eos(); r.advance()) {
-    if (r.type() == MAP_TRANSITION) {
-      // Get target.
-      Map* target = Map::cast(r.GetValue());
-#ifdef DEBUG
-      // Verify target.
-      Object* source_prototype = prototype();
-      Object* target_prototype = target->prototype();
-      ASSERT(source_prototype->IsJSObject() ||
-             source_prototype->IsMap() ||
-             source_prototype->IsNull());
-      ASSERT(target_prototype->IsJSObject() ||
-             target_prototype->IsNull());
-      ASSERT(source_prototype->IsMap() ||
-          source_prototype == target_prototype);
-#endif
-      // Point target back to source.  set_prototype() will not let us set
-      // the prototype to a map, as we do here.
-      RawField(target, kPrototypeOffset) = this;
-    }
-  }
-}
-
-
-void Map::ClearNonLiveTransitions(Object* real_prototype) {
-  // Live DescriptorArray objects will be marked, so we must use
-  // low-level accessors to get and modify their data.
-  DescriptorArray* d = reinterpret_cast<DescriptorArray*>(
-      RawField(this, Map::kInstanceDescriptorsOffset));
-  if (d == Heap::empty_descriptor_array()) return;
-  Smi* NullDescriptorDetails =
-    PropertyDetails(NONE, NULL_DESCRIPTOR).AsSmi();
-  FixedArray* contents = reinterpret_cast<FixedArray*>(
-      d->get(DescriptorArray::kContentArrayIndex));
-  ASSERT(contents->length() >= 2);
-  for (int i = 0; i < contents->length(); i += 2) {
-    // If the pair (value, details) is a map transition,
-    // check if the target is live.  If not, null the descriptor.
-    // Also drop the back pointer for that map transition, so that this
-    // map is not reached again by following a back pointer from a
-    // non-live object.
-    PropertyDetails details(Smi::cast(contents->get(i + 1)));
-    if (details.type() == MAP_TRANSITION) {
-      Map* target = reinterpret_cast<Map*>(contents->get(i));
-      ASSERT(target->IsHeapObject());
-      if (!target->IsMarked()) {
-        ASSERT(target->IsMap());
-        contents->set(i + 1, NullDescriptorDetails, SKIP_WRITE_BARRIER);
-        contents->set(i, Heap::null_value(), SKIP_WRITE_BARRIER);
-        ASSERT(target->prototype() == this ||
-               target->prototype() == real_prototype);
-        // Getter prototype() is read-only, set_prototype() has side effects.
-        RawField(target, Map::kPrototypeOffset) = real_prototype;
-      }
-    }
-  }
-}
-
-
 void Map::MapIterateBody(ObjectVisitor* v) {
   // Assumes all Object* members are contiguously allocated!
   IteratePointers(v, kPrototypeOffset, kCodeCacheOffset + kPointerSize);