Directly remove slot buffer entries in deoptimized code objects.

test/cctest/test-heap.cc

Index: test/cctest/test-heap.cc
diff --git a/test/cctest/test-heap.cc b/test/cctest/test-heap.cc
index 668fb01e1723de450e396ac176e23e0202d8c9e2..64235409299198926d3453ee12f77e6216eced26 100644
--- a/test/cctest/test-heap.cc
+++ b/test/cctest/test-heap.cc
@@ -6015,3 +6015,45 @@ TEST(AllocationThroughput) {
   throughput = tracer->AllocationThroughputInBytesPerMillisecond(100);
   CHECK_EQ(2 * (counter3 - counter1) / (time3 - time1), throughput);
 }
+
+
+TEST(SlotsBufferObjectSlotsRemoval) {
+  CcTest::InitializeVM();
+  v8::HandleScope scope(CcTest::isolate());
+  Isolate* isolate = CcTest::i_isolate();
+  Heap* heap = isolate->heap();
+  Factory* factory = isolate->factory();
+
+  SlotsBuffer* buffer = new SlotsBuffer(NULL);
+  void* fake_object[1];
+
+  Handle<FixedArray> array = factory->NewFixedArray(2, TENURED);
+  CHECK(heap->old_space()->Contains(*array));
+  array->set(0, reinterpret_cast<Object*>(fake_object), SKIP_WRITE_BARRIER);
+
+  // Firstly, let's test the regular slots buffer entry.
+  buffer->Add(HeapObject::RawField(*array, FixedArray::kHeaderSize));
+  DCHECK(reinterpret_cast<void*>(buffer->Get(0)) ==
+         HeapObject::RawField(*array, FixedArray::kHeaderSize));
+  SlotsBuffer::RemoveObjectSlots(CcTest::i_isolate()->heap(), buffer, *array);
+  DCHECK(reinterpret_cast<void*>(buffer->Get(0)) ==
+         HeapObject::RawField(heap->empty_fixed_array(),
+                              FixedArrayBase::kLengthOffset));
+
+  // Secondly, let's test the typed slots buffer entry.
+  SlotsBuffer::AddTo(NULL, &buffer, SlotsBuffer::EMBEDDED_OBJECT_SLOT,
+                     array->address() + FixedArray::kHeaderSize,
+                     SlotsBuffer::FAIL_ON_OVERFLOW);
+  DCHECK(reinterpret_cast<void*>(buffer->Get(1)) ==
+         reinterpret_cast<Object**>(SlotsBuffer::EMBEDDED_OBJECT_SLOT));
+  DCHECK(reinterpret_cast<void*>(buffer->Get(2)) ==
+         HeapObject::RawField(*array, FixedArray::kHeaderSize));
+  SlotsBuffer::RemoveObjectSlots(CcTest::i_isolate()->heap(), buffer, *array);
+  DCHECK(reinterpret_cast<void*>(buffer->Get(1)) ==
+         HeapObject::RawField(heap->empty_fixed_array(),
+                              FixedArrayBase::kLengthOffset));
+  DCHECK(reinterpret_cast<void*>(buffer->Get(2)) ==
+         HeapObject::RawField(heap->empty_fixed_array(),
+                              FixedArrayBase::kLengthOffset));
+  delete buffer;
+}