[objects] do not visit ArrayBuffer's backing store

test/cctest/test-api.cc

 // Copyright 2012 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 14205 matching lines @@
   Local<v8::ArrayBuffer> ab =
       v8::ArrayBuffer::New(isolate, backing_store.start(), 2 + kSize);
   Local<v8::DataView> dv = v8::DataView::New(ab, 2, kSize);
   CheckInternalFieldsAreZero<v8::ArrayBufferView>(dv);
   CHECK_EQ(2u, dv->ByteOffset());
   CHECK_EQ(kSize, static_cast<int>(dv->ByteLength()));
   CHECK(ab->Equals(dv->Buffer()));
 }
 
 
+THREADED_TEST(SkipArrayBufferBackingStoreDuringGC) {
+  const int kSize = 64;
+
+  LocalContext env;
+  v8::Isolate* isolate = env->GetIsolate();
+  v8::HandleScope handle_scope(isolate);
+
+  // Make sure the pointer looks like a heap object
+  uint8_t* store_ptr = reinterpret_cast<uint8_t*>(i::kHeapObjectTag);
+
+  // Create ArrayBuffer with pointer-that-cannot-be-visited in the backing store
+  Local<v8::ArrayBuffer> ab = v8::ArrayBuffer::New(isolate, store_ptr, 8);
+
+  // Should not crash
+  CcTest::heap()->CollectGarbage(i::NEW_SPACE);  // in survivor space now
+  CcTest::heap()->CollectGarbage(i::NEW_SPACE);  // in old gen now
+  CcTest::heap()->CollectAllGarbage();
+  CcTest::heap()->CollectAllGarbage();
+
+  // Should not move the pointer
+  CHECK_EQ(ab->GetContents().Data(), store_ptr);
+}
+
+
 THREADED_TEST(SharedUint8Array) {
   i::FLAG_harmony_sharedarraybuffer = true;
   TypedArrayTestHelper<uint8_t, v8::Uint8Array, i::FixedUint8Array,
                        v8::SharedArrayBuffer>(i::kExternalUint8Array, 0, 0xFF);
 }
 
 
 THREADED_TEST(SharedInt8Array) {
   i::FLAG_harmony_sharedarraybuffer = true;
   TypedArrayTestHelper<int8_t, v8::Int8Array, i::FixedInt8Array,
@@ skipping 7614 matching lines @@
   timeout_thread.Join();
 }
 
 
 TEST(EstimatedContextSize) {
   v8::Isolate* isolate = CcTest::isolate();
   v8::HandleScope scope(isolate);
   LocalContext env;
   CHECK(50000 < env->EstimatedSize());
 }