text: // 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
  //       with the distribution.
  //     * Neither the name of Google Inc. nor the names of its
  //       contributors may be used to endorse or promote products derived
  //       from this software without specific prior written permission.
  //
  // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  
  #include <stdlib.h>
  #include <utility>
  
  #include "src/compilation-cache.h"
  #include "src/context-measure.h"
  #include "src/deoptimizer.h"
  #include "src/elements.h"
  #include "src/execution.h"
  #include "src/factory.h"
  #include "src/field-type.h"
  #include "src/global-handles.h"
  #include "src/heap/gc-tracer.h"
  #include "src/heap/memory-reducer.h"
  #include "src/ic/ic.h"
  #include "src/macro-assembler.h"
  #include "src/regexp/jsregexp.h"
  #include "src/snapshot/snapshot.h"
  #include "test/cctest/cctest.h"
  #include "test/cctest/heap/heap-tester.h"
  #include "test/cctest/heap/heap-utils.h"
  #include "test/cctest/test-feedback-vector.h"
  
  
  namespace v8 {
  namespace internal {
  
  static void CheckMap(Map* map, int type, int instance_size) {
    CHECK(map->IsHeapObject());
  #ifdef DEBUG
    CHECK(CcTest::heap()->Contains(map));
  #endif
    CHECK_EQ(CcTest::heap()->meta_map(), map->map());
    CHECK_EQ(type, map->instance_type());
    CHECK_EQ(instance_size, map->instance_size());
  }
  
  
  TEST(HeapMaps) {
    CcTest::InitializeVM();
    Heap* heap = CcTest::heap();
    CheckMap(heap->meta_map(), MAP_TYPE, Map::kSize);
    CheckMap(heap->heap_number_map(), HEAP_NUMBER_TYPE, HeapNumber::kSize);
  #define SIMD128_TYPE(TYPE, Type, type, lane_count, lane_type) \
    CheckMap(heap->type##_map(), SIMD128_VALUE_TYPE, Type::kSize);
    SIMD128_TYPES(SIMD128_TYPE)
  #undef SIMD128_TYPE
    CheckMap(heap->fixed_array_map(), FIXED_ARRAY_TYPE, kVariableSizeSentinel);
    CheckMap(heap->string_map(), STRING_TYPE, kVariableSizeSentinel);
  }
  
  
  static void CheckOddball(Isolate* isolate, Object* obj, const char* string) {
    CHECK(obj->IsOddball());
    Handle<Object> handle(obj, isolate);
    Object* print_string = *Object::ToString(isolate, handle).ToHandleChecked();
    CHECK(String::cast(print_string)->IsUtf8EqualTo(CStrVector(string)));
  }
  
  
  static void CheckSmi(Isolate* isolate, int value, const char* string) {
    Handle<Object> handle(Smi::FromInt(value), isolate);
    Object* print_string = *Object::ToString(isolate, handle).ToHandleChecked();
    CHECK(String::cast(print_string)->IsUtf8EqualTo(CStrVector(string)));
  }
  
  
  static void CheckNumber(Isolate* isolate, double value, const char* string) {
    Handle<Object> number = isolate->factory()->NewNumber(value);
    CHECK(number->IsNumber());
    Handle<Object> print_string =
        Object::ToString(isolate, number).ToHandleChecked();
    CHECK(String::cast(*print_string)->IsUtf8EqualTo(CStrVector(string)));
  }
  
  void CheckEmbeddedObjectsAreEqual(Handle<Code> lhs, Handle<Code> rhs) {
    int mode_mask = RelocInfo::ModeMask(RelocInfo::EMBEDDED_OBJECT);
    RelocIterator lhs_it(*lhs, mode_mask);
    RelocIterator rhs_it(*rhs, mode_mask);
    while (!lhs_it.done() && !rhs_it.done()) {
      CHECK(lhs_it.rinfo()->target_object() == rhs_it.rinfo()->target_object());
  
      lhs_it.next();
      rhs_it.next();
    }
    CHECK(lhs_it.done() == rhs_it.done());
  }
  
  HEAP_TEST(TestNewSpaceRefsInCopiedCode) {
    CcTest::InitializeVM();
    Isolate* isolate = CcTest::i_isolate();
    Factory* factory = isolate->factory();
    Heap* heap = isolate->heap();
    HandleScope sc(isolate);
  
    Handle<Object> value = factory->NewNumber(1.000123);
    CHECK(heap->InNewSpace(*value));
  
    i::byte buffer[i::Assembler::kMinimalBufferSize];
    MacroAssembler masm(isolate, buffer, sizeof(buffer),
                        v8::internal::CodeObjectRequired::kYes);
    // Add a new-space reference to the code.
    masm.Push(value);
  
    CodeDesc desc;
    masm.GetCode(&desc);
    Handle<Code> code = isolate->factory()->NewCode(
        desc, Code::ComputeFlags(Code::STUB), Handle<Code>());
  
    Code* tmp = nullptr;
    heap->CopyCode(*code).To(&tmp);
    Handle<Code> copy(tmp);
  
    CheckEmbeddedObjectsAreEqual(code, copy);
    heap->CollectAllAvailableGarbage();
    CheckEmbeddedObjectsAreEqual(code, copy);
  }
  
  static void CheckFindCodeObject(Isolate* isolate) {
    // Test FindCodeObject
  #define __ assm.
  
    Assembler assm(isolate, NULL, 0);
  
    __ nop();  // supported on all architectures
  
    CodeDesc desc;
    assm.GetCode(&desc);
    Handle<Code> code = isolate->factory()->NewCode(
        desc, Code::ComputeFlags(Code::STUB), Handle<Code>());
    CHECK(code->IsCode());
  
    HeapObject* obj = HeapObject::cast(*code);
    Address obj_addr = obj->address();
  
    for (int i = 0; i < obj->Size(); i += kPointerSize) {
      Object* found = isolate->FindCodeObject(obj_addr + i);
      CHECK_EQ(*code, found);
    }
  
    Handle<Code> copy = isolate->factory()->NewCode(
        desc, Code::ComputeFlags(Code::STUB), Handle<Code>());
    HeapObject* obj_copy = HeapObject::cast(*copy);
    Object* not_right = isolate->FindCodeObject(obj_copy->address() +
                                                obj_copy->Size() / 2);
    CHECK(not_right != *code);
  }
  
  
  TEST(HandleNull) {
    CcTest::InitializeVM();
    Isolate* isolate = CcTest::i_isolate();
    HandleScope outer_scope(isolate);
    LocalContext context;
    Handle<Object> n(static_cast<Object*>(nullptr), isolate);
    CHECK(!n.is_null());
  }
  
  
  TEST(HeapObjects) {
    CcTest::InitializeVM();
    Isolate* isolate = CcTest::i_isolate();
    Factory* factory = isolate->factory();
    Heap* heap = isolate->heap();
  
    HandleScope sc(isolate);
    Handle<Object> value = factory->NewNumber(1.000123);
    CHECK(value->IsHeapNumber());
    CHECK(value->IsNumber());
    CHECK_EQ(1.000123, value->Number());
  
    value = factory->NewNumber(1.0);
    CHECK(value->IsSmi());
    CHECK(value->IsNumber());
    CHECK_EQ(1.0, value->Number());
  
    value = factory->NewNumberFromInt(1024);
    CHECK(value->IsSmi());
    CHECK(value->IsNumber());
    CHECK_EQ(1024.0, value->Number());
  
    value = factory->NewNumberFromInt(Smi::kMinValue);
    CHECK(value->IsSmi());
    CHECK(value->IsNumber());
    CHECK_EQ(Smi::kMinValue, Handle<Smi>::cast(value)->value());
  
    value = factory->NewNumberFromInt(Smi::kMaxValue);
    CHECK(value->IsSmi());
    CHECK(value->IsNumber());
    CHECK_EQ(Smi::kMaxValue, Handle<Smi>::cast(value)->value());
  
  #if !defined(V8_TARGET_ARCH_64_BIT)
    // TODO(lrn): We need a NumberFromIntptr function in order to test this.
    value = factory->NewNumberFromInt(Smi::kMinValue - 1);
    CHECK(value->IsHeapNumber());
    CHECK(value->IsNumber());
    CHECK_EQ(static_cast<double>(Smi::kMinValue - 1), value->Number());
  #endif
  
    value = factory->NewNumberFromUint(static_cast<uint32_t>(Smi::kMaxValue) + 1);
    CHECK(value->IsHeapNumber());
    CHECK(value->IsNumber());
    CHECK_EQ(static_cast<double>(static_cast<uint32_t>(Smi::kMaxValue) + 1),
             value->Number());
  
    value = factory->NewNumberFromUint(static_cast<uint32_t>(1) << 31);
    CHECK(value->IsHeapNumber());
    CHECK(value->IsNumber());
    CHECK_EQ(static_cast<double>(static_cast<uint32_t>(1) << 31),
             value->Number());
  
    // nan oddball checks
    CHECK(factory->nan_value()->IsNumber());
    CHECK(std::isnan(factory->nan_value()->Number()));
  
    Handle<String> s = factory->NewStringFromStaticChars("fisk hest ");
    CHECK(s->IsString());
    CHECK_EQ(10, s->length());
  
    Handle<String> object_string = Handle<String>::cast(factory->Object_string());
    Handle<JSGlobalObject> global(
        CcTest::i_isolate()->context()->global_object());
    CHECK(Just(true) == JSReceiver::HasOwnProperty(global, object_string));
  
    // Check ToString for oddballs
    CheckOddball(isolate, heap->true_value(), "true");
    CheckOddball(isolate, heap->false_value(), "false");
    CheckOddball(isolate, heap->null_value(), "null");
    CheckOddball(isolate, heap->undefined_value(), "undefined");
  
    // Check ToString for Smis
    CheckSmi(isolate, 0, "0");
    CheckSmi(isolate, 42, "42");
    CheckSmi(isolate, -42, "-42");
  
    // Check ToString for Numbers
    CheckNumber(isolate, 1.1, "1.1");
  
    CheckFindCodeObject(isolate);
  }
  
  
  template <typename T, typename LANE_TYPE, int LANES>
  static void CheckSimdValue(T* value, LANE_TYPE lane_values[LANES],
                             LANE_TYPE other_value) {
    // Check against lane_values, and check that all lanes can be set to
    // other_value without disturbing the other lanes.
    for (int i = 0; i < LANES; i++) {
      CHECK_EQ(lane_values[i], value->get_lane(i));
    }
    for (int i = 0; i < LANES; i++) {
      value->set_lane(i, other_value);  // change the value
      for (int j = 0; j < LANES; j++) {
        if (i != j)
          CHECK_EQ(lane_values[j], value->get_lane(j));
        else
          CHECK_EQ(other_value, value->get_lane(j));
      }
      value->set_lane(i, lane_values[i]);  // restore the lane
    }
    CHECK(value->BooleanValue());  // SIMD values are 'true'.
  }
  
  
  TEST(SimdObjects) {
    CcTest::InitializeVM();
    Isolate* isolate = CcTest::i_isolate();
    Factory* factory = isolate->factory();
  
    HandleScope sc(isolate);
  
    // Float32x4
    {
      float lanes[4] = {1, 2, 3, 4};
      float quiet_NaN = std::numeric_limits<float>::quiet_NaN();
      float signaling_NaN = std::numeric_limits<float>::signaling_NaN();
  
      Handle<Float32x4> value = factory->NewFloat32x4(lanes);
      CHECK(value->IsFloat32x4());
      CheckSimdValue<Float32x4, float, 4>(*value, lanes, 3.14f);
  
      // Check special lane values.
      value->set_lane(1, -0.0);
      CHECK_EQ(-0.0f, value->get_lane(1));
      CHECK(std::signbit(value->get_lane(1)));  // Sign bit should be preserved.
      value->set_lane(2, quiet_NaN);
      CHECK(std::isnan(value->get_lane(2)));
      value->set_lane(3, signaling_NaN);
      CHECK(std::isnan(value->get_lane(3)));
  
  #ifdef OBJECT_PRINT
      // Check value printing.
      {
        value = factory->NewFloat32x4(lanes);
        std::ostringstream os;
        value->Float32x4Print(os);
        CHECK_EQ("1, 2, 3, 4", os.str());
      }
      {
        float special_lanes[4] = {0, -0.0, quiet_NaN, signaling_NaN};
        value = factory->NewFloat32x4(special_lanes);
        std::ostringstream os;
        value->Float32x4Print(os);
        // Value printing doesn't preserve signed zeroes.
        CHECK_EQ("0, 0, NaN, NaN", os.str());
      }
  #endif  // OBJECT_PRINT
    }
    // Int32x4
    {
      int32_t lanes[4] = {1, 2, 3, 4};
  
      Handle<Int32x4> value = factory->NewInt32x4(lanes);
      CHECK(value->IsInt32x4());
      CheckSimdValue<Int32x4, int32_t, 4>(*value, lanes, 3);
  
  #ifdef OBJECT_PRINT
      std::ostringstream os;
      value->Int32x4Print(os);
      CHECK_EQ("1, 2, 3, 4", os.str());
  #endif  // OBJECT_PRINT
    }
    // Uint32x4
    {
      uint32_t lanes[4] = {1, 2, 3, 4};
  
      Handle<Uint32x4> value = factory->NewUint32x4(lanes);
      CHECK(value->IsUint32x4());
      CheckSimdValue<Uint32x4, uint32_t, 4>(*value, lanes, 3);
  
  #ifdef OBJECT_PRINT
      std::ostringstream os;
      value->Uint32x4Print(os);
      CHECK_EQ("1, 2, 3, 4", os.str());
  #endif  // OBJECT_PRINT
    }
    // Bool32x4
    {
      bool lanes[4] = {true, false, true, false};
  
      Handle<Bool32x4> value = factory->NewBool32x4(lanes);
      CHECK(value->IsBool32x4());
      CheckSimdValue<Bool32x4, bool, 4>(*value, lanes, false);
  
  #ifdef OBJECT_PRINT
      std::ostringstream os;
      value->Bool32x4Print(os);
      CHECK_EQ("true, false, true, false", os.str());
  #endif  // OBJECT_PRINT
    }
    // Int16x8
    {
      int16_t lanes[8] = {1, 2, 3, 4, 5, 6, 7, 8};
  
      Handle<Int16x8> value = factory->NewInt16x8(lanes);
      CHECK(value->IsInt16x8());
      CheckSimdValue<Int16x8, int16_t, 8>(*value, lanes, 32767);
  
  #ifdef OBJECT_PRINT
      std::ostringstream os;
      value->Int16x8Print(os);
      CHECK_EQ("1, 2, 3, 4, 5, 6, 7, 8", os.str());
  #endif  // OBJECT_PRINT
    }
    // Uint16x8
    {
      uint16_t lanes[8] = {1, 2, 3, 4, 5, 6, 7, 8};
  
      Handle<Uint16x8> value = factory->NewUint16x8(lanes);
      CHECK(value->IsUint16x8());
      CheckSimdValue<Uint16x8, uint16_t, 8>(*value, lanes, 32767);
  
  #ifdef OBJECT_PRINT
      std::ostringstream os;
      value->Uint16x8Print(os);
      CHECK_EQ("1, 2, 3, 4, 5, 6, 7, 8", os.str());
  #endif  // OBJECT_PRINT
    }
    // Bool16x8
    {
      bool lanes[8] = {true, false, true, false, true, false, true, false};
  
      Handle<Bool16x8> value = factory->NewBool16x8(lanes);
      CHECK(value->IsBool16x8());
      CheckSimdValue<Bool16x8, bool, 8>(*value, lanes, false);
  
  #ifdef OBJECT_PRINT
      std::ostringstream os;
      value->Bool16x8Print(os);
      CHECK_EQ("true, false, true, false, true, false, true, false", os.str());
  #endif  // OBJECT_PRINT
    }
    // Int8x16
    {
      int8_t lanes[16] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16};
  
      Handle<Int8x16> value = factory->NewInt8x16(lanes);
      CHECK(value->IsInt8x16());
      CheckSimdValue<Int8x16, int8_t, 16>(*value, lanes, 127);
  
  #ifdef OBJECT_PRINT
      std::ostringstream os;
      value->Int8x16Print(os);
      CHECK_EQ("1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16", os.str());
  #endif  // OBJECT_PRINT
    }
    // Uint8x16
    {
      uint8_t lanes[16] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16};
  
      Handle<Uint8x16> value = factory->NewUint8x16(lanes);
      CHECK(value->IsUint8x16());
      CheckSimdValue<Uint8x16, uint8_t, 16>(*value, lanes, 127);
  
  #ifdef OBJECT_PRINT
      std::ostringstream os;
      value->Uint8x16Print(os);
      CHECK_EQ("1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16", os.str());
  #endif  // OBJECT_PRINT
    }
    // Bool8x16
    {
      bool lanes[16] = {true, false, true, false, true, false, true, false,
                        true, false, true, false, true, false, true, false};
  
      Handle<Bool8x16> value = factory->NewBool8x16(lanes);
      CHECK(value->IsBool8x16());
      CheckSimdValue<Bool8x16, bool, 16>(*value, lanes, false);
  
  #ifdef OBJECT_PRINT
      std::ostringstream os;
      value->Bool8x16Print(os);
      CHECK_EQ(
          "true, false, true, false, true, false, true, false, true, false, "
          "true, false, true, false, true, false",
          os.str());
  #endif  // OBJECT_PRINT
    }
  }
  
  
  TEST(Tagging) {
    CcTest::InitializeVM();
    int request = 24;
    CHECK_EQ(request, static_cast<int>(OBJECT_POINTER_ALIGN(request)));
    CHECK(Smi::FromInt(42)->IsSmi());
    CHECK(Smi::FromInt(Smi::kMinValue)->IsSmi());
    CHECK(Smi::FromInt(Smi::kMaxValue)->IsSmi());
  }
  
  
  TEST(GarbageCollection) {
    CcTest::InitializeVM();
    Isolate* isolate = CcTest::i_isolate();
    Heap* heap = isolate->heap();
    Factory* factory = isolate->factory();
  
    HandleScope sc(isolate);
    // Check GC.
    heap->CollectGarbage(NEW_SPACE);
  
    Handle<JSGlobalObject> global(
        CcTest::i_isolate()->context()->global_object());
    Handle<String> name = factory->InternalizeUtf8String("theFunction");
    Handle<String> prop_name = factory->InternalizeUtf8String("theSlot");
    Handle<String> prop_namex = factory->InternalizeUtf8String("theSlotx");
    Handle<String> obj_name = factory->InternalizeUtf8String("theObject");
    Handle<Smi> twenty_three(Smi::FromInt(23), isolate);
    Handle<Smi> twenty_four(Smi::FromInt(24), isolate);
  
    {
      HandleScope inner_scope(isolate);
      // Allocate a function and keep it in global object's property.
      Handle<JSFunction> function = factory->NewFunction(name);
      JSReceiver::SetProperty(global, name, function, SLOPPY).Check();
      // Allocate an object.  Unrooted after leaving the scope.
      Handle<JSObject> obj = factory->NewJSObject(function);
      JSReceiver::SetProperty(obj, prop_name, twenty_three, SLOPPY).Check();
      JSReceiver::SetProperty(obj, prop_namex, twenty_four, SLOPPY).Check();
  
      CHECK_EQ(Smi::FromInt(23),
               *Object::GetProperty(obj, prop_name).ToHandleChecked());
      CHECK_EQ(Smi::FromInt(24),
               *Object::GetProperty(obj, prop_namex).ToHandleChecked());
    }
  
    heap->CollectGarbage(NEW_SPACE);
  
    // Function should be alive.
    CHECK(Just(true) == JSReceiver::HasOwnProperty(global, name));
    // Check function is retained.
    Handle<Object> func_value =
        Object::GetProperty(global, name).ToHandleChecked();
    CHECK(func_value->IsJSFunction());
    Handle<JSFunction> function = Handle<JSFunction>::cast(func_value);
  
    {
      HandleScope inner_scope(isolate);
      // Allocate another object, make it reachable from global.
      Handle<JSObject> obj = factory->NewJSObject(function);
      JSReceiver::SetProperty(global, obj_name, obj, SLOPPY).Check();
      JSReceiver::SetProperty(obj, prop_name, twenty_three, SLOPPY).Check();
    }
  
    // After gc, it should survive.
    heap->CollectGarbage(NEW_SPACE);
  
    CHECK(Just(true) == JSReceiver::HasOwnProperty(global, obj_name));
    Handle<Object> obj =
        Object::GetProperty(global, obj_name).ToHandleChecked();
    CHECK(obj->IsJSObject());
    CHECK_EQ(Smi::FromInt(23),
             *Object::GetProperty(obj, prop_name).ToHandleChecked());
  }
  
  
  static void VerifyStringAllocation(Isolate* isolate, const char* string) {
    HandleScope scope(isolate);
    Handle<String> s = isolate->factory()->NewStringFromUtf8(
        CStrVector(string)).ToHandleChecked();
    CHECK_EQ(StrLength(string), s->length());
    for (int index = 0; index < s->length(); index++) {
      CHECK_EQ(static_cast<uint16_t>(string[index]), s->Get(index));
    }
  }
  
  
  TEST(String) {
    CcTest::InitializeVM();
    Isolate* isolate = reinterpret_cast<Isolate*>(CcTest::isolate());
  
    VerifyStringAllocation(isolate, "a");
    VerifyStringAllocation(isolate, "ab");
    VerifyStringAllocation(isolate, "abc");
    VerifyStringAllocation(isolate, "abcd");
    VerifyStringAllocation(isolate, "fiskerdrengen er paa havet");
  }
  
  
  TEST(LocalHandles) {
    CcTest::InitializeVM();
    Isolate* isolate = CcTest::i_isolate();
    Factory* factory = isolate->factory();
  
    v8::HandleScope scope(CcTest::isolate());
    const char* name = "Kasper the spunky";
    Handle<String> string = factory->NewStringFromAsciiChecked(name);
    CHECK_EQ(StrLength(name), string->length());
  }
  
  
  TEST(GlobalHandles) {
    CcTest::InitializeVM();
    Isolate* isolate = CcTest::i_isolate();
    Heap* heap = isolate->heap();
    Factory* factory = isolate->factory();
    GlobalHandles* global_handles = isolate->global_handles();
  
    Handle<Object> h1;
    Handle<Object> h2;
    Handle<Object> h3;
    Handle<Object> h4;
  
    {
      HandleScope scope(isolate);
  
      Handle<Object> i = factory->NewStringFromStaticChars("fisk");
      Handle<Object> u = factory->NewNumber(1.12344);
  
      h1 = global_handles->Create(*i);
      h2 = global_handles->Create(*u);
      h3 = global_handles->Create(*i);
      h4 = global_handles->Create(*u);
    }
  
    // after gc, it should survive
    heap->CollectGarbage(NEW_SPACE);
  
    CHECK((*h1)->IsString());
    CHECK((*h2)->IsHeapNumber());
    CHECK((*h3)->IsString());
    CHECK((*h4)->IsHeapNumber());
  
    CHECK_EQ(*h3, *h1);
    GlobalHandles::Destroy(h1.location());
    GlobalHandles::Destroy(h3.location());
  
    CHECK_EQ(*h4, *h2);
    GlobalHandles::Destroy(h2.location());
    GlobalHandles::Destroy(h4.location());
  }
  
  
  static bool WeakPointerCleared = false;
  
  static void TestWeakGlobalHandleCallback(
      const v8::WeakCallbackInfo<void>& data) {
    std::pair<v8::Persistent<v8::Value>*, int>* p =
        reinterpret_cast<std::pair<v8::Persistent<v8::Value>*, int>*>(
            data.GetParameter());
    if (p->second == 1234) WeakPointerCleared = true;
    p->first->Reset();
  }
  
  
  TEST(WeakGlobalHandlesScavenge) {
    i::FLAG_stress_compaction = false;
    CcTest::InitializeVM();
    Isolate* isolate = CcTest::i_isolate();
    Heap* heap = isolate->heap();
    Factory* factory = isolate->factory();
    GlobalHandles* global_handles = isolate->global_handles();
  
    WeakPointerCleared = false;
  
    Handle<Object> h1;
    Handle<Object> h2;
  
    {
      HandleScope scope(isolate);
  
      Handle<Object> i = factory->NewStringFromStaticChars("fisk");
      Handle<Object> u = factory->NewNumber(1.12344);
  
      h1 = global_handles->Create(*i);
      h2 = global_handles->Create(*u);
    }
  
    std::pair<Handle<Object>*, int> handle_and_id(&h2, 1234);
    GlobalHandles::MakeWeak(
        h2.location(), reinterpret_cast<void*>(&handle_and_id),
        &TestWeakGlobalHandleCallback, v8::WeakCallbackType::kParameter);
  
    // Scavenge treats weak pointers as normal roots.
    heap->CollectGarbage(NEW_SPACE);
  
    CHECK((*h1)->IsString());
    CHECK((*h2)->IsHeapNumber());
  
    CHECK(!WeakPointerCleared);
    CHECK(!global_handles->IsNearDeath(h2.location()));
    CHECK(!global_handles->IsNearDeath(h1.location()));
  
    GlobalHandles::Destroy(h1.location());
    GlobalHandles::Destroy(h2.location());
  }
  
  
  TEST(WeakGlobalHandlesMark) {
    CcTest::InitializeVM();
    Isolate* isolate = CcTest::i_isolate();
    Heap* heap = isolate->heap();
    Factory* factory = isolate->factory();
    GlobalHandles* global_handles = isolate->global_handles();
  
    WeakPointerCleared = false;
  
    Handle<Object> h1;
    Handle<Object> h2;
  
    {
      HandleScope scope(isolate);
  
      Handle<Object> i = factory->NewStringFromStaticChars("fisk");
      Handle<Object> u = factory->NewNumber(1.12344);
  
      h1 = global_handles->Create(*i);
      h2 = global_handles->Create(*u);
    }
  
    // Make sure the objects are promoted.
    heap->CollectGarbage(OLD_SPACE);
    heap->CollectGarbage(NEW_SPACE);
    CHECK(!heap->InNewSpace(*h1) && !heap->InNewSpace(*h2));
  
    std::pair<Handle<Object>*, int> handle_and_id(&h2, 1234);
    GlobalHandles::MakeWeak(
        h2.location(), reinterpret_cast<void*>(&handle_and_id),
        &TestWeakGlobalHandleCallback, v8::WeakCallbackType::kParameter);
    CHECK(!GlobalHandles::IsNearDeath(h1.location()));
    CHECK(!GlobalHandles::IsNearDeath(h2.location()));
  
    // Incremental marking potentially marked handles before they turned weak.
    heap->CollectAllGarbage();
  
    CHECK((*h1)->IsString());
  
    CHECK(WeakPointerCleared);
    CHECK(!GlobalHandles::IsNearDeath(h1.location()));
  
    GlobalHandles::Destroy(h1.location());
  }
  
  
  TEST(DeleteWeakGlobalHandle) {
    i::FLAG_stress_compaction = false;
    CcTest::InitializeVM();
    Isolate* isolate = CcTest::i_isolate();
    Heap* heap = isolate->heap();
    Factory* factory = isolate->factory();
    GlobalHandles* global_handles = isolate->global_handles();
  
    WeakPointerCleared = false;
  
    Handle<Object> h;
  
    {
      HandleScope scope(isolate);
  
      Handle<Object> i = factory->NewStringFromStaticChars("fisk");
      h = global_handles->Create(*i);
    }
  
    std::pair<Handle<Object>*, int> handle_and_id(&h, 1234);
    GlobalHandles::MakeWeak(h.location(), reinterpret_cast<void*>(&handle_and_id),
                            &TestWeakGlobalHandleCallback,
                            v8::WeakCallbackType::kParameter);
  
    // Scanvenge does not recognize weak reference.
    heap->CollectGarbage(NEW_SPACE);
  
    CHECK(!WeakPointerCleared);
  
    // Mark-compact treats weak reference properly.
    heap->CollectGarbage(OLD_SPACE);
  
    CHECK(WeakPointerCleared);
  }
  
  TEST(DoNotPromoteWhiteObjectsOnScavenge) {
    CcTest::InitializeVM();
    Isolate* isolate = CcTest::i_isolate();
    Heap* heap = isolate->heap();
    Factory* factory = isolate->factory();
  
    HandleScope scope(isolate);
    Handle<Object> white = factory->NewStringFromStaticChars("white");
  
    CHECK(Marking::IsWhite(ObjectMarking::MarkBitFrom(HeapObject::cast(*white))));
  
    heap->CollectGarbage(NEW_SPACE);
  
    CHECK(heap->InNewSpace(*white));
  }
  
  TEST(PromoteGreyOrBlackObjectsOnScavenge) {
    CcTest::InitializeVM();
    Isolate* isolate = CcTest::i_isolate();
    Heap* heap = isolate->heap();
    Factory* factory = isolate->factory();
  
    HandleScope scope(isolate);
    Handle<Object> marked = factory->NewStringFromStaticChars("marked");
  
    IncrementalMarking* marking = heap->incremental_marking();
    marking->Stop();
    heap->StartIncrementalMarking();
    while (
        Marking::IsWhite(ObjectMarking::MarkBitFrom(HeapObject::cast(*marked)))) {
      marking->Step(MB, IncrementalMarking::NO_GC_VIA_STACK_GUARD,
                    IncrementalMarking::FORCE_MARKING,
                    IncrementalMarking::DO_NOT_FORCE_COMPLETION);
    }
  
    heap->CollectGarbage(NEW_SPACE);
  
    CHECK(!heap->InNewSpace(*marked));
  }
  
  TEST(BytecodeArray) {
    static const uint8_t kRawBytes[] = {0xc3, 0x7e, 0xa5, 0x5a};
    static const int kRawBytesSize = sizeof(kRawBytes);
    static const int kFrameSize = 32;
    static const int kParameterCount = 2;
  
    i::FLAG_manual_evacuation_candidates_selection = true;
    CcTest::InitializeVM();
    Isolate* isolate = CcTest::i_isolate();
    Heap* heap = isolate->heap();
    Factory* factory = isolate->factory();
    HandleScope scope(isolate);
  
    heap::SimulateFullSpace(heap->old_space());
    Handle<FixedArray> constant_pool = factory->NewFixedArray(5, TENURED);
    for (int i = 0; i < 5; i++) {
      Handle<Object> number = factory->NewHeapNumber(i);
      constant_pool->set(i, *number);
    }
  
    // Allocate and initialize BytecodeArray
    Handle<BytecodeArray> array = factory->NewBytecodeArray(
        kRawBytesSize, kRawBytes, kFrameSize, kParameterCount, constant_pool);
  
    CHECK(array->IsBytecodeArray());
    CHECK_EQ(array->length(), (int)sizeof(kRawBytes));
    CHECK_EQ(array->frame_size(), kFrameSize);
    CHECK_EQ(array->parameter_count(), kParameterCount);
    CHECK_EQ(array->constant_pool(), *constant_pool);
    CHECK_LE(array->address(), array->GetFirstBytecodeAddress());
    CHECK_GE(array->address() + array->BytecodeArraySize(),
             array->GetFirstBytecodeAddress() + array->length());
    for (int i = 0; i < kRawBytesSize; i++) {
      CHECK_EQ(array->GetFirstBytecodeAddress()[i], kRawBytes[i]);
      CHECK_EQ(array->get(i), kRawBytes[i]);
    }
  
    FixedArray* old_constant_pool_address = *constant_pool;
  
    // Perform a full garbage collection and force the constant pool to be on an
    // evacuation candidate.
    Page* evac_page = Page::FromAddress(constant_pool->address());
    evac_page->SetFlag(MemoryChunk::FORCE_EVACUATION_CANDIDATE_FOR_TESTING);
    heap->CollectAllGarbage();
  
    // BytecodeArray should survive.
    CHECK_EQ(array->length(), kRawBytesSize);
    CHECK_EQ(array->frame_size(), kFrameSize);
    for (int i = 0; i < kRawBytesSize; i++) {
      CHECK_EQ(array->get(i), kRawBytes[i]);
      CHECK_EQ(array->GetFirstBytecodeAddress()[i], kRawBytes[i]);
    }
  
    // Constant pool should have been migrated.
    CHECK_EQ(array->constant_pool(), *constant_pool);
    CHECK_NE(array->constant_pool(), old_constant_pool_address);
  }
  
  
  static const char* not_so_random_string_table[] = {
    "abstract",
    "boolean",
    "break",
    "byte",
    "case",
    "catch",
    "char",
    "class",
    "const",
    "continue",
    "debugger",
    "default",
    "delete",
    "do",
    "double",
    "else",
    "enum",
    "export",
    "extends",
    "false",
    "final",
    "finally",
    "float",
    "for",
    "function",
    "goto",
    "if",
    "implements",
    "import",
    "in",
    "instanceof",
    "int",
    "interface",
    "long",
    "native",
    "new",
    "null",
    "package",
    "private",
    "protected",
    "public",
    "return",
    "short",
    "static",
    "super",
    "switch",
    "synchronized",
    "this",
    "throw",
    "throws",
    "transient",
    "true",
    "try",
    "typeof",
    "var",
    "void",
    "volatile",
    "while",
    "with",
    0
  };
  
  
  static void CheckInternalizedStrings(const char** strings) {
    Isolate* isolate = CcTest::i_isolate();
    Factory* factory = isolate->factory();
    for (const char* string = *strings; *strings != 0; string = *strings++) {
      HandleScope scope(isolate);
      Handle<String> a =
          isolate->factory()->InternalizeUtf8String(CStrVector(string));
      // InternalizeUtf8String may return a failure if a GC is needed.
      CHECK(a->IsInternalizedString());
      Handle<String> b = factory->InternalizeUtf8String(string);
      CHECK_EQ(*b, *a);
      CHECK(b->IsUtf8EqualTo(CStrVector(string)));
      b = isolate->factory()->InternalizeUtf8String(CStrVector(string));
      CHECK_EQ(*b, *a);
      CHECK(b->IsUtf8EqualTo(CStrVector(string)));
    }
  }
  
  
  TEST(StringTable) {
    CcTest::InitializeVM();
  
    v8::HandleScope sc(CcTest::isolate());
    CheckInternalizedStrings(not_so_random_string_table);
    CheckInternalizedStrings(not_so_random_string_table);
  }
  
  
  TEST(FunctionAllocation) {
    CcTest::InitializeVM();
    Isolate* isolate = CcTest::i_isolate();
    Factory* factory = isolate->factory();
  
    v8::HandleScope sc(CcTest::isolate());
    Handle<String> name = factory->InternalizeUtf8String("theFunction");
    Handle<JSFunction> function = factory->NewFunction(name);
  
    Handle<Smi> twenty_three(Smi::FromInt(23), isolate);
    Handle<Smi> twenty_four(Smi::FromInt(24), isolate);
  
    Handle<String> prop_name = factory->InternalizeUtf8String("theSlot");
    Handle<JSObject> obj = factory->NewJSObject(function);
    JSReceiver::SetProperty(obj, prop_name, twenty_three, SLOPPY).Check();
    CHECK_EQ(Smi::FromInt(23),
             *Object::GetProperty(obj, prop_name).ToHandleChecked());
    // Check that we can add properties to function objects.
    JSReceiver::SetProperty(function, prop_name, twenty_four, SLOPPY).Check();
    CHECK_EQ(Smi::FromInt(24),
             *Object::GetProperty(function, prop_name).ToHandleChecked());
  }
  
  
  TEST(ObjectProperties) {
    CcTest::InitializeVM();
    Isolate* isolate = CcTest::i_isolate();
    Factory* factory = isolate->factory();
  
    v8::HandleScope sc(CcTest::isolate());
    Handle<String> object_string(String::cast(CcTest::heap()->Object_string()));
    Handle<Object> object = Object::GetProperty(
        CcTest::i_isolate()->global_object(), object_string).ToHandleChecked();
    Handle<JSFunction> constructor = Handle<JSFunction>::cast(object);
    Handle<JSObject> obj = factory->NewJSObject(constructor);
    Handle<String> first = factory->InternalizeUtf8String("first");
    Handle<String> second = factory->InternalizeUtf8String("second");
  
    Handle<Smi> one(Smi::FromInt(1), isolate);
    Handle<Smi> two(Smi::FromInt(2), isolate);
  
    // check for empty
    CHECK(Just(false) == JSReceiver::HasOwnProperty(obj, first));
  
    // add first
    JSReceiver::SetProperty(obj, first, one, SLOPPY).Check();
    CHECK(Just(true) == JSReceiver::HasOwnProperty(obj, first));
  
    // delete first
    CHECK(Just(true) == JSReceiver::DeleteProperty(obj, first, SLOPPY));
    CHECK(Just(false) == JSReceiver::HasOwnProperty(obj, first));
  
    // add first and then second
    JSReceiver::SetProperty(obj, first, one, SLOPPY).Check();
    JSReceiver::SetProperty(obj, second, two, SLOPPY).Check();
    CHECK(Just(true) == JSReceiver::HasOwnProperty(obj, first));
    CHECK(Just(true) == JSReceiver::HasOwnProperty(obj, second));
  
    // delete first and then second
    CHECK(Just(true) == JSReceiver::DeleteProperty(obj, first, SLOPPY));
    CHECK(Just(true) == JSReceiver::HasOwnProperty(obj, second));
    CHECK(Just(true) == JSReceiver::DeleteProperty(obj, second, SLOPPY));
    CHECK(Just(false) == JSReceiver::HasOwnProperty(obj, first));
    CHECK(Just(false) == JSReceiver::HasOwnProperty(obj, second));
  
    // add first and then second
    JSReceiver::SetProperty(obj, first, one, SLOPPY).Check();
    JSReceiver::SetProperty(obj, second, two, SLOPPY).Check();
    CHECK(Just(true) == JSReceiver::HasOwnProperty(obj, first));
    CHECK(Just(true) == JSReceiver::HasOwnProperty(obj, second));
  
    // delete second and then first
    CHECK(Just(true) == JSReceiver::DeleteProperty(obj, second, SLOPPY));
    CHECK(Just(true) == JSReceiver::HasOwnProperty(obj, first));
    CHECK(Just(true) == JSReceiver::DeleteProperty(obj, first, SLOPPY));
    CHECK(Just(false) == JSReceiver::HasOwnProperty(obj, first));
    CHECK(Just(false) == JSReceiver::HasOwnProperty(obj, second));
  
    // check string and internalized string match
    const char* string1 = "fisk";
    Handle<String> s1 = factory->NewStringFromAsciiChecked(string1);
    JSReceiver::SetProperty(obj, s1, one, SLOPPY).Check();
    Handle<String> s1_string = factory->InternalizeUtf8String(string1);
    CHECK(Just(true) == JSReceiver::HasOwnProperty(obj, s1_string));
  
    // check internalized string and string match
    const char* string2 = "fugl";
    Handle<String> s2_string = factory->InternalizeUtf8String(string2);
    JSReceiver::SetProperty(obj, s2_string, one, SLOPPY).Check();
    Handle<String> s2 = factory->NewStringFromAsciiChecked(string2);
    CHECK(Just(true) == JSReceiver::HasOwnProperty(obj, s2));
  }
  
  
  TEST(JSObjectMaps) {
    CcTest::InitializeVM();
    Isolate* isolate = CcTest::i_isolate();
    Factory* factory = isolate->factory();
  
    v8::HandleScope sc(CcTest::isolate());
    Handle<String> name = factory->InternalizeUtf8String("theFunction");
    Handle<JSFunction> function = factory->NewFunction(name);
  
    Handle<String> prop_name = factory->InternalizeUtf8String("theSlot");
    Handle<JSObject> obj = factory->NewJSObject(function);
    Handle<Map> initial_map(function->initial_map());
  
    // Set a propery
    Handle<Smi> twenty_three(Smi::FromInt(23), isolate);
    JSReceiver::SetProperty(obj, prop_name, twenty_three, SLOPPY).Check();
    CHECK_EQ(Smi::FromInt(23),
             *Object::GetProperty(obj, prop_name).ToHandleChecked());
  
    // Check the map has changed
    CHECK(*initial_map != obj->map());
  }
  
  
  TEST(JSArray) {
    CcTest::InitializeVM();
    Isolate* isolate = CcTest::i_isolate();
    Factory* factory = isolate->factory();
  
    v8::HandleScope sc(CcTest::isolate());
    Handle<String> name = factory->InternalizeUtf8String("Array");
    Handle<Object> fun_obj = Object::GetProperty(
        CcTest::i_isolate()->global_object(), name).ToHandleChecked();
    Handle<JSFunction> function = Handle<JSFunction>::cast(fun_obj);
  
    // Allocate the object.
    Handle<Object> element;
    Handle<JSObject> object = factory->NewJSObject(function);
    Handle<JSArray> array = Handle<JSArray>::cast(object);
    // We just initialized the VM, no heap allocation failure yet.
    JSArray::Initialize(array, 0);
  
    // Set array length to 0.
    JSArray::SetLength(array, 0);
    CHECK_EQ(Smi::FromInt(0), array->length());
    // Must be in fast mode.
    CHECK(array->HasFastSmiOrObjectElements());
  
    // array[length] = name.
    JSReceiver::SetElement(isolate, array, 0, name, SLOPPY).Check();
    CHECK_EQ(Smi::FromInt(1), array->length());
    element = i::Object::GetElement(isolate, array, 0).ToHandleChecked();
    CHECK_EQ(*element, *name);
  
    // Set array length with larger than smi value.
    JSArray::SetLength(array, static_cast<uint32_t>(Smi::kMaxValue) + 1);
  
    uint32_t int_length = 0;
    CHECK(array->length()->ToArrayIndex(&int_length));
    CHECK_EQ(static_cast<uint32_t>(Smi::kMaxValue) + 1, int_length);
    CHECK(array->HasDictionaryElements());  // Must be in slow mode.
  
    // array[length] = name.
    JSReceiver::SetElement(isolate, array, int_length, name, SLOPPY).Check();
    uint32_t new_int_length = 0;
    CHECK(array->length()->ToArrayIndex(&new_int_length));
    CHECK_EQ(static_cast<double>(int_length), new_int_length - 1);
    element = Object::GetElement(isolate, array, int_length).ToHandleChecked();
    CHECK_EQ(*element, *name);
    element = Object::GetElement(isolate, array, 0).ToHandleChecked();
    CHECK_EQ(*element, *name);
  }
  
  
  TEST(JSObjectCopy) {
    CcTest::InitializeVM();
    Isolate* isolate = CcTest::i_isolate();
    Factory* factory = isolate->factory();
  
    v8::HandleScope sc(CcTest::isolate());
    Handle<String> object_string(String::cast(CcTest::heap()->Object_string()));
    Handle<Object> object = Object::GetProperty(
        CcTest::i_isolate()->global_object(), object_string).ToHandleChecked();
    Handle<JSFunction> constructor = Handle<JSFunction>::cast(object);
    Handle<JSObject> obj = factory->NewJSObject(constructor);
    Handle<String> first = factory->InternalizeUtf8String("first");
    Handle<String> second = factory->InternalizeUtf8String("second");
  
    Handle<Smi> one(Smi::FromInt(1), isolate);
    Handle<Smi> two(Smi::FromInt(2), isolate);
  
    JSReceiver::SetProperty(obj, first, one, SLOPPY).Check();
    JSReceiver::SetProperty(obj, second, two, SLOPPY).Check();
  
    JSReceiver::SetElement(isolate, obj, 0, first, SLOPPY).Check();
    JSReceiver::SetElement(isolate, obj, 1, second, SLOPPY).Check();
  
    // Make the clone.
    Handle<Object> value1, value2;
    Handle<JSObject> clone = factory->CopyJSObject(obj);
    CHECK(!clone.is_identical_to(obj));
  
    value1 = Object::GetElement(isolate, obj, 0).ToHandleChecked();
    value2 = Object::GetElement(isolate, clone, 0).ToHandleChecked();
    CHECK_EQ(*value1, *value2);
    value1 = Object::GetElement(isolate, obj, 1).ToHandleChecked();
    value2 = Object::GetElement(isolate, clone, 1).ToHandleChecked();
    CHECK_EQ(*value1, *value2);
  
    value1 = Object::GetProperty(obj, first).ToHandleChecked();
    value2 = Object::GetProperty(clone, first).ToHandleChecked();
    CHECK_EQ(*value1, *value2);
    value1 = Object::GetProperty(obj, second).ToHandleChecked();
    value2 = Object::GetProperty(clone, second).ToHandleChecked();
    CHECK_EQ(*value1, *value2);
  
    // Flip the values.
    JSReceiver::SetProperty(clone, first, two, SLOPPY).Check();
    JSReceiver::SetProperty(clone, second, one, SLOPPY).Check();
  
    JSReceiver::SetElement(isolate, clone, 0, second, SLOPPY).Check();
    JSReceiver::SetElement(isolate, clone, 1, first, SLOPPY).Check();
  
    value1 = Object::GetElement(isolate, obj, 1).ToHandleChecked();
    value2 = Object::GetElement(isolate, clone, 0).ToHandleChecked();
    CHECK_EQ(*value1, *value2);
    value1 = Object::GetElement(isolate, obj, 0).ToHandleChecked();
    value2 = Object::GetElement(isolate, clone, 1).ToHandleChecked();
    CHECK_EQ(*value1, *value2);
  
    value1 = Object::GetProperty(obj, second).ToHandleChecked();
    value2 = Object::GetProperty(clone, first).ToHandleChecked();
    CHECK_EQ(*value1, *value2);
    value1 = Object::GetProperty(obj, first).ToHandleChecked();
    value2 = Object::GetProperty(clone, second).ToHandleChecked();
    CHECK_EQ(*value1, *value2);
  }
  
  
  TEST(StringAllocation) {
    CcTest::InitializeVM();
    Isolate* isolate = CcTest::i_isolate();
    Factory* factory = isolate->factory();
  
    const unsigned char chars[] = { 0xe5, 0xa4, 0xa7 };
    for (int length = 0; length < 100; length++) {
      v8::HandleScope scope(CcTest::isolate());
      char* non_one_byte = NewArray<char>(3 * length + 1);
      char* one_byte = NewArray<char>(length + 1);
      non_one_byte[3 * length] = 0;
      one_byte[length] = 0;
      for (int i = 0; i < length; i++) {
        one_byte[i] = 'a';
        non_one_byte[3 * i] = chars[0];
        non_one_byte[3 * i + 1] = chars[1];
        non_one_byte[3 * i + 2] = chars[2];
      }
      Handle<String> non_one_byte_sym = factory->InternalizeUtf8String(
          Vector<const char>(non_one_byte, 3 * length));
      CHECK_EQ(length, non_one_byte_sym->length());
      Handle<String> one_byte_sym =
          factory->InternalizeOneByteString(OneByteVector(one_byte, length));
      CHECK_EQ(length, one_byte_sym->length());
      Handle<String> non_one_byte_str =
          factory->NewStringFromUtf8(Vector<const char>(non_one_byte, 3 * length))
              .ToHandleChecked();
      non_one_byte_str->Hash();
      CHECK_EQ(length, non_one_byte_str->length());
      Handle<String> one_byte_str =
          factory->NewStringFromUtf8(Vector<const char>(one_byte, length))
              .ToHandleChecked();
      one_byte_str->Hash();
      CHECK_EQ(length, one_byte_str->length());
      DeleteArray(non_one_byte);
      DeleteArray(one_byte);
    }
  }
  
  
  static int ObjectsFoundInHeap(Heap* heap, Handle<Object> objs[], int size) {
    // Count the number of objects found in the heap.
    int found_count = 0;
    HeapIterator iterator(heap);
    for (HeapObject* obj = iterator.next(); obj != NULL; obj = iterator.next()) {
      for (int i = 0; i < size; i++) {
        if (*objs[i] == obj) {
          found_count++;
        }
      }
    }
    return found_count;
  }
  
  
  TEST(Iteration) {
    CcTest::InitializeVM();
    Isolate* isolate = CcTest::i_isolate();
    Factory* factory = isolate->factory();
    v8::HandleScope scope(CcTest::isolate());
  
    // Array of objects to scan haep for.
    const int objs_count = 6;
    Handle<Object> objs[objs_count];
    int next_objs_index = 0;
  
    // Allocate a JS array to OLD_SPACE and NEW_SPACE
    objs[next_objs_index++] = factory->NewJSArray(10);
    objs[next_objs_index++] =
        factory->NewJSArray(10, FAST_HOLEY_ELEMENTS, TENURED);
  
    // Allocate a small string to OLD_DATA_SPACE and NEW_SPACE
    objs[next_objs_index++] = factory->NewStringFromStaticChars("abcdefghij");
    objs[next_objs_index++] =
        factory->NewStringFromStaticChars("abcdefghij", TENURED);
  
    // Allocate a large string (for large object space).
    int large_size = Page::kMaxRegularHeapObjectSize + 1;
    char* str = new char[large_size];
    for (int i = 0; i < large_size - 1; ++i) str[i] = 'a';
    str[large_size - 1] = '\0';
    objs[next_objs_index++] = factory->NewStringFromAsciiChecked(str, TENURED);
    delete[] str;
  
    // Add a Map object to look for.
    objs[next_objs_index++] = Handle<Map>(HeapObject::cast(*objs[0])->map());
  
    CHECK_EQ(objs_count, next_objs_index);
    CHECK_EQ(objs_count, ObjectsFoundInHeap(CcTest::heap(), objs, objs_count));
  }
  
  
  UNINITIALIZED_TEST(TestCodeFlushing) {
    // If we do not flush code this test is invalid.
    if (!FLAG_flush_code) return;
    i::FLAG_allow_natives_syntax = true;
    i::FLAG_optimize_for_size = false;
    v8::Isolate::CreateParams create_params;
    create_params.array_buffer_allocator = CcTest::array_buffer_allocator();
    v8::Isolate* isolate = v8::Isolate::New(create_params);
    i::Isolate* i_isolate = reinterpret_cast<i::Isolate*>(isolate);
    isolate->Enter();
    Factory* factory = i_isolate->factory();
    {
      v8::HandleScope scope(isolate);
      v8::Context::New(isolate)->Enter();
      const char* source =
          "function foo() {"
          "  var x = 42;"
          "  var y = 42;"
          "  var z = x + y;"
          "};"
          "foo()";
      Handle<String> foo_name = factory->InternalizeUtf8String("foo");
  
      // This compile will add the code to the compilation cache.
      {
        v8::HandleScope scope(isolate);
        CompileRun(source);
      }
  
      // Check function is compiled.
      Handle<Object> func_value = Object::GetProperty(i_isolate->global_object(),
                                                      foo_name).ToHandleChecked();
      CHECK(func_value->IsJSFunction());
      Handle<JSFunction> function = Handle<JSFunction>::cast(func_value);
      CHECK(function->shared()->is_compiled());
  
      // The code will survive at least two GCs.
      i_isolate->heap()->CollectAllGarbage();
      i_isolate->heap()->CollectAllGarbage();
      CHECK(function->shared()->is_compiled());
  
      // Simulate several GCs that use full marking.
      const int kAgingThreshold = 6;
      for (int i = 0; i < kAgingThreshold; i++) {
        i_isolate->heap()->CollectAllGarbage();
      }
  
      // foo should no longer be in the compilation cache
      CHECK(!function->shared()->is_compiled() || function->IsOptimized());
      CHECK(!function->is_compiled() || function->IsOptimized());
      // Call foo to get it recompiled.
      CompileRun("foo()");
      CHECK(function->shared()->is_compiled());
      CHECK(function->is_compiled());
    }
    isolate->Exit();
    isolate->Dispose();
  }
  
  
  TEST(TestCodeFlushingPreAged) {
    // If we do not flush code this test is invalid.
    if (!FLAG_flush_code) return;
    i::FLAG_allow_natives_syntax = true;
    i::FLAG_optimize_for_size = true;
    CcTest::InitializeVM();
    Isolate* isolate = CcTest::i_isolate();
    Factory* factory = isolate->factory();
    v8::HandleScope scope(CcTest::isolate());
    const char* source = "function foo() {"
                         "  var x = 42;"
                         "  var y = 42;"
                         "  var z = x + y;"
                         "};"
                         "foo()";
    Handle<String> foo_name = factory->InternalizeUtf8String("foo");
  
    // Compile foo, but don't run it.
    { v8::HandleScope scope(CcTest::isolate());
      CompileRun(source);
    }
  
    // Check function is compiled.
    Handle<Object> func_value =
        Object::GetProperty(isolate->global_object(), foo_name).ToHandleChecked();
    CHECK(func_value->IsJSFunction());
    Handle<JSFunction> function = Handle<JSFunction>::cast(func_value);
    CHECK(function->shared()->is_compiled());
  
    // The code has been run so will survive at least one GC.
    CcTest::heap()->CollectAllGarbage();
    CHECK(function->shared()->is_compiled());
  
    // The code was only run once, so it should be pre-aged and collected on the
    // next GC.
    CcTest::heap()->CollectAllGarbage();
    CHECK(!function->shared()->is_compiled() || function->IsOptimized());
  
    // Execute the function again twice, and ensure it is reset to the young age.
    { v8::HandleScope scope(CcTest::isolate());
      CompileRun("foo();"
                 "foo();");
    }
  
    // The code will survive at least two GC now that it is young again.
    CcTest::heap()->CollectAllGarbage();
    CcTest::heap()->CollectAllGarbage();
    CHECK(function->shared()->is_compiled());
  
    // Simulate several GCs that use full marking.
    const int kAgingThreshold = 6;
    for (int i = 0; i < kAgingThreshold; i++) {
      CcTest::heap()->CollectAllGarbage();
    }
  
    // foo should no longer be in the compilation cache
    CHECK(!function->shared()->is_compiled() || function->IsOptimized());
    CHECK(!function->is_compiled() || function->IsOptimized());
    // Call foo to get it recompiled.
    CompileRun("foo()");
    CHECK(function->shared()->is_compiled());
    CHECK(function->is_compiled());
  }
  
  
  TEST(TestCodeFlushingIncremental) {
    // If we do not flush code this test is invalid.
    if (!FLAG_flush_code) return;
    i::FLAG_allow_natives_syntax = true;
    i::FLAG_optimize_for_size = false;
    CcTest::InitializeVM();
    Isolate* isolate = CcTest::i_isolate();
    Factory* factory = isolate->factory();
    v8::HandleScope scope(CcTest::isolate());
    const char* source = "function foo() {"
                         "  var x = 42;"
                         "  var y = 42;"
                         "  var z = x + y;"
                         "};"
                         "foo()";
    Handle<String> foo_name = factory->InternalizeUtf8String("foo");
  
    // This compile will add the code to the compilation cache.
    { v8::HandleScope scope(CcTest::isolate());
      CompileRun(source);
    }
  
    // Check function is compiled.
    Handle<Object> func_value =
        Object::GetProperty(isolate->global_object(), foo_name).ToHandleChecked();
    CHECK(func_value->IsJSFunction());
    Handle<JSFunction> function = Handle<JSFunction>::cast(func_value);
    CHECK(function->shared()->is_compiled());
  
    // The code will survive at least two GCs.
    CcTest::heap()->CollectAllGarbage();
    CcTest::heap()->CollectAllGarbage();
    CHECK(function->shared()->is_compiled());
  
    // Simulate several GCs that use incremental marking.
    const int kAgingThreshold = 6;
    for (int i = 0; i < kAgingThreshold; i++) {
      heap::SimulateIncrementalMarking(CcTest::heap());
      CcTest::heap()->CollectAllGarbage();
    }
    CHECK(!function->shared()->is_compiled() || function->IsOptimized());
    CHECK(!function->is_compiled() || function->IsOptimized());
  
    // This compile will compile the function again.
    { v8::HandleScope scope(CcTest::isolate());
      CompileRun("foo();");
    }
  
    // Simulate several GCs that use incremental marking but make sure
    // the loop breaks once the function is enqueued as a candidate.
    for (int i = 0; i < kAgingThreshold; i++) {
      heap::SimulateIncrementalMarking(CcTest::heap());
      if (!function->next_function_link()->IsUndefined(CcTest::i_isolate()))
        break;
      CcTest::heap()->CollectAllGarbage();
    }
  
    // Force optimization while incremental marking is active and while
    // the function is enqueued as a candidate.
    { v8::HandleScope scope(CcTest::isolate());
      CompileRun("%OptimizeFunctionOnNextCall(foo); foo();");
    }
  
    // Simulate one final GC to make sure the candidate queue is sane.
    CcTest::heap()->CollectAllGarbage();
    CHECK(function->shared()->is_compiled() || !function->IsOptimized());
    CHECK(function->is_compiled() || !function->IsOptimized());
  }
  
  
  TEST(TestCodeFlushingIncrementalScavenge) {
    // If we do not flush code this test is invalid.
    if (!FLAG_flush_code) return;
    i::FLAG_allow_natives_syntax = true;
    i::FLAG_optimize_for_size = false;
    CcTest::InitializeVM();
    Isolate* isolate = CcTest::i_isolate();
    Factory* factory = isolate->factory();
    v8::HandleScope scope(CcTest::isolate());
    const char* source = "var foo = function() {"
                         "  var x = 42;"
                         "  var y = 42;"
                         "  var z = x + y;"
                         "};"
                         "foo();"
                         "var bar = function() {"
                         "  var x = 23;"
                         "};"
                         "bar();";
    Handle<String> foo_name = factory->InternalizeUtf8String("foo");
    Handle<String> bar_name = factory->InternalizeUtf8String("bar");
  
    // Perfrom one initial GC to enable code flushing.
    CcTest::heap()->CollectAllGarbage();
  
    // This compile will add the code to the compilation cache.
    { v8::HandleScope scope(CcTest::isolate());
      CompileRun(source);
    }
  
    // Check functions are compiled.
    Handle<Object> func_value =
        Object::GetProperty(isolate->global_object(), foo_name).ToHandleChecked();
    CHECK(func_value->IsJSFunction());
    Handle<JSFunction> function = Handle<JSFunction>::cast(func_value);
    CHECK(function->shared()->is_compiled());
    Handle<Object> func_value2 =
        Object::GetProperty(isolate->global_object(), bar_name).ToHandleChecked();
    CHECK(func_value2->IsJSFunction());
    Handle<JSFunction> function2 = Handle<JSFunction>::cast(func_value2);
    CHECK(function2->shared()->is_compiled());
  
    // Clear references to functions so that one of them can die.
    { v8::HandleScope scope(CcTest::isolate());
      CompileRun("foo = 0; bar = 0;");
    }
  
    // Bump the code age so that flushing is triggered while the function
    // object is still located in new-space.
    const int kAgingThreshold = 6;
    for (int i = 0; i < kAgingThreshold; i++) {
      function->shared()->code()->MakeOlder(static_cast<MarkingParity>(i % 2));
      function2->shared()->code()->MakeOlder(static_cast<MarkingParity>(i % 2));
    }
  
    // Simulate incremental marking so that the functions are enqueued as
    // code flushing candidates. Then kill one of the functions. Finally
    // perform a scavenge while incremental marking is still running.
    heap::SimulateIncrementalMarking(CcTest::heap(), false);
    *function2.location() = NULL;
    CcTest::heap()->CollectGarbage(NEW_SPACE, "test scavenge while marking");
  
    // Simulate one final GC to make sure the candidate queue is sane.
    CcTest::heap()->CollectAllGarbage();
    CHECK(!function->shared()->is_compiled() || function->IsOptimized());
    CHECK(!function->is_compiled() || function->IsOptimized());
  }
  
  
  TEST(TestCodeFlushingIncrementalAbort) {
    // If we do not flush code this test is invalid.
    if (!FLAG_flush_code) return;
    i::FLAG_allow_natives_syntax = true;
    i::FLAG_optimize_for_size = false;
    CcTest::InitializeVM();
    Isolate* isolate = CcTest::i_isolate();
    Factory* factory = isolate->factory();
    Heap* heap = isolate->heap();
    v8::HandleScope scope(CcTest::isolate());
    const char* source = "function foo() {"
                         "  var x = 42;"
                         "  var y = 42;"
                         "  var z = x + y;"
                         "};"
                         "foo()";
    Handle<String> foo_name = factory->InternalizeUtf8String("foo");
  
    // This compile will add the code to the compilation cache.
    { v8::HandleScope scope(CcTest::isolate());
      CompileRun(source);
    }
  
    // Check function is compiled.
    Handle<Object> func_value =
        Object::GetProperty(isolate->global_object(), foo_name).ToHandleChecked();
    CHECK(func_value->IsJSFunction());
    Handle<JSFunction> function = Handle<JSFunction>::cast(func_value);
    CHECK(function->shared()->is_compiled());
  
    // The code will survive at least two GCs.
    heap->CollectAllGarbage();
    heap->CollectAllGarbage();
    CHECK(function->shared()->is_compiled());
  
    // Bump the code age so that flushing is triggered.
    const int kAgingThreshold = 6;
    for (int i = 0; i < kAgingThreshold; i++) {
      function->shared()->code()->MakeOlder(static_cast<MarkingParity>(i % 2));
    }
  
    // Simulate incremental marking so that the function is enqueued as
    // code flushing candidate.
    heap::SimulateIncrementalMarking(heap);
  
    // Enable the debugger and add a breakpoint while incremental marking
    // is running so that incremental marking aborts and code flushing is
    // disabled.
    int position = function->shared()->start_position();
    Handle<Object> breakpoint_object(Smi::FromInt(0), isolate);
    EnableDebugger(CcTest::isolate());
    isolate->debug()->SetBreakPoint(function, breakpoint_object, &position);
    isolate->debug()->ClearAllBreakPoints();
    DisableDebugger(CcTest::isolate());
  
    // Force optimization now that code flushing is disabled.
    { v8::HandleScope scope(CcTest::isolate());
      CompileRun("%OptimizeFunctionOnNextCall(foo); foo();");
    }
  
    // Simulate one final GC to make sure the candidate queue is sane.
    heap->CollectAllGarbage();
    CHECK(function->shared()->is_compiled() || !function->IsOptimized());
    CHECK(function->is_compiled() || !function->IsOptimized());
  }
  
  TEST(TestUseOfIncrementalBarrierOnCompileLazy) {
    // Turn off always_opt because it interferes with running the built-in for
    // the last call to g().
    i::FLAG_always_opt = false;
    i::FLAG_allow_natives_syntax = true;
    CcTest::InitializeVM();
    Isolate* isolate = CcTest::i_isolate();
    Factory* factory = isolate->factory();
    Heap* heap = isolate->heap();
    v8::HandleScope scope(CcTest::isolate());
  
    CompileRun(
        "function make_closure(x) {"
        "  return function() { return x + 3 };"
        "}"
        "var f = make_closure(5); f();"
        "var g = make_closure(5);");
  
    // Check f is compiled.
    Handle<String> f_name = factory->InternalizeUtf8String("f");
    Handle<Object> f_value =
        Object::GetProperty(isolate->global_object(), f_name).ToHandleChecked();
    Handle<JSFunction> f_function = Handle<JSFunction>::cast(f_value);
    CHECK(f_function->is_compiled());
  
    // Check g is not compiled.
    Handle<String> g_name = factory->InternalizeUtf8String("g");
    Handle<Object> g_value =
        Object::GetProperty(isolate->global_object(), g_name).ToHandleChecked();
    Handle<JSFunction> g_function = Handle<JSFunction>::cast(g_value);
    CHECK(!g_function->is_compiled());
  
    heap::SimulateIncrementalMarking(heap);
    CompileRun("%OptimizeFunctionOnNextCall(f); f();");
  
    // g should now have available an optimized function, unmarked by gc. The
    // CompileLazy built-in will discover it and install it in the closure, and
    // the incremental write barrier should be used.
    CompileRun("g();");
    CHECK(g_function->is_compiled());
  }
  
  TEST(CompilationCacheCachingBehavior) {
    // If we do not flush code, or have the compilation cache turned off, this
    // test is invalid.
    if (!FLAG_flush_code || !FLAG_compilation_cache) {
      return;
    }
    CcTest::InitializeVM();
    Isolate* isolate = CcTest::i_isolate();
    Factory* factory = isolate->factory();
    Heap* heap = isolate->heap();
    CompilationCache* compilation_cache = isolate->compilation_cache();
    LanguageMode language_mode = construct_language_mode(FLAG_use_strict);
  
    v8::HandleScope scope(CcTest::isolate());
    const char* raw_source =
        "function foo() {"
        "  var x = 42;"
        "  var y = 42;"
        "  var z = x + y;"
        "};"
        "foo()";
    Handle<String> source = factory->InternalizeUtf8String(raw_source);
    Handle<Context> native_context = isolate->native_context();
  
    {
      v8::HandleScope scope(CcTest::isolate());
      CompileRun(raw_source);
    }
  
    // The script should be in the cache now.
    MaybeHandle<SharedFunctionInfo> info = compilation_cache->LookupScript(
        source, Handle<Object>(), 0, 0,
        v8::ScriptOriginOptions(false, true, false), native_context,
        language_mode);
    CHECK(!info.is_null());
  
    // Check that the code cache entry survives at least on GC.
    // (Unless --optimize-for-size, in which case it might get collected
    // immediately.)
    if (!FLAG_optimize_for_size) {
      heap->CollectAllGarbage();
      info = compilation_cache->LookupScript(
          source, Handle<Object>(), 0, 0,
          v8::ScriptOriginOptions(false, true, false), native_context,
          language_mode);
      CHECK(!info.is_null());
    }
  
    // Progress code age until it's old and ready for GC.
    while (!info.ToHandleChecked()->code()->IsOld()) {
      // To guarantee progress, we have to MakeOlder with different parities.
      // We can't just use NO_MARKING_PARITY, since e.g. kExecutedOnceCodeAge is
      // always NO_MARKING_PARITY and the code age only progresses if the parity
      // is different.
      info.ToHandleChecked()->code()->MakeOlder(ODD_MARKING_PARITY);
      info.ToHandleChecked()->code()->MakeOlder(EVEN_MARKING_PARITY);
    }
  
    heap->CollectAllGarbage();
    // Ensure code aging cleared the entry from the cache.
    info = compilation_cache->LookupScript(
        source, Handle<Object>(), 0, 0,
        v8::ScriptOriginOptions(false, true, false), native_context,
        language_mode);
    CHECK(info.is_null());
  }
  
  
  static void OptimizeEmptyFunction(const char* name) {
    HandleScope scope(CcTest::i_isolate());
    EmbeddedVector<char, 256> source;
    SNPrintF(source,
             "function %s() { return 0; }"
             "%s(); %s();"
             "%%OptimizeFunctionOnNextCall(%s);"
             "%s();",
             name, name, name, name, name);
    CompileRun(source.start());
  }
  
  
  // Count the number of native contexts in the weak list of native contexts.
  int CountNativeContexts() {
    int count = 0;
    Object* object = CcTest::heap()->native_contexts_list();
    while (!object->IsUndefined(CcTest::i_isolate())) {
      count++;
      object = Context::cast(object)->next_context_link();
    }
    return count;
  }
  
  
  // Count the number of user functions in the weak list of optimized
  // functions attached to a native context.
  static int CountOptimizedUserFunctions(v8::Local<v8::Context> context) {
    int count = 0;
    Handle<Context> icontext = v8::Utils::OpenHandle(*context);
    Object* object = icontext->get(Context::OPTIMIZED_FUNCTIONS_LIST);
    while (object->IsJSFunction() &&
           !JSFunction::cast(object)->shared()->IsBuiltin()) {
      count++;
      object = JSFunction::cast(object)->next_function_link();
    }
    return count;
  }
  
  
  TEST(TestInternalWeakLists) {
    FLAG_always_opt = false;
    FLAG_allow_natives_syntax = true;
    v8::V8::Initialize();
  
    // Some flags turn Scavenge collections into Mark-sweep collections
    // and hence are incompatible with this test case.
    if (FLAG_gc_global || FLAG_stress_compaction) return;
    FLAG_retain_maps_for_n_gc = 0;
  
    static const int kNumTestContexts = 10;
  
    Isolate* isolate = CcTest::i_isolate();
    Heap* heap = isolate->heap();
    HandleScope scope(isolate);
    v8::Local<v8::Context> ctx[kNumTestContexts];
    if (!isolate->use_crankshaft()) return;
  
    CHECK_EQ(0, CountNativeContexts());
  
    // Create a number of global contests which gets linked together.
    for (int i = 0; i < kNumTestContexts; i++) {
      ctx[i] = v8::Context::New(CcTest::isolate());
  
      // Collect garbage that might have been created by one of the
      // installed extensions.
      isolate->compilation_cache()->Clear();
      heap->CollectAllGarbage();
  
      CHECK_EQ(i + 1, CountNativeContexts());
  
      ctx[i]->Enter();
  
      // Create a handle scope so no function objects get stuck in the outer
      // handle scope.
      HandleScope scope(isolate);
      CHECK_EQ(0, CountOptimizedUserFunctions(ctx[i]));
      OptimizeEmptyFunction("f1");
      CHECK_EQ(1, CountOptimizedUserFunctions(ctx[i]));
      OptimizeEmptyFunction("f2");
      CHECK_EQ(2, CountOptimizedUserFunctions(ctx[i]));
      OptimizeEmptyFunction("f3");
      CHECK_EQ(3, CountOptimizedUserFunctions(ctx[i]));
      OptimizeEmptyFunction("f4");
      CHECK_EQ(4, CountOptimizedUserFunctions(ctx[i]));
      OptimizeEmptyFunction("f5");
      CHECK_EQ(5, CountOptimizedUserFunctions(ctx[i]));
  
      // Remove function f1, and
      CompileRun("f1=null");
  
      // Scavenge treats these references as strong.
      for (int j = 0; j < 10; j++) {
        CcTest::heap()->CollectGarbage(NEW_SPACE);
        CHECK_EQ(5, CountOptimizedUserFunctions(ctx[i]));
      }
  
      // Mark compact handles the weak references.
      isolate->compilation_cache()->Clear();
      heap->CollectAllGarbage();
      CHECK_EQ(4, CountOptimizedUserFunctions(ctx[i]));
  
      // Get rid of f3 and f5 in the same way.
      CompileRun("f3=null");
      for (int j = 0; j < 10; j++) {
        CcTest::heap()->CollectGarbage(NEW_SPACE);
        CHECK_EQ(4, CountOptimizedUserFunctions(ctx[i]));
      }
      CcTest::heap()->CollectAllGarbage();
      CHECK_EQ(3, CountOptimizedUserFunctions(ctx[i]));
      CompileRun("f5=null");
      for (int j = 0; j < 10; j++) {
        CcTest::heap()->CollectGarbage(NEW_SPACE);
        CHECK_EQ(3, CountOptimizedUserFunctions(ctx[i]));
      }
      CcTest::heap()->CollectAllGarbage();
      CHECK_EQ(2, CountOptimizedUserFunctions(ctx[i]));
  
      ctx[i]->Exit();
    }
  
    // Force compilation cache cleanup.
    CcTest::heap()->NotifyContextDisposed(true);
    CcTest::heap()->CollectAllGarbage();
  
    // Dispose the native contexts one by one.
    for (int i = 0; i < kNumTestContexts; i++) {
      // TODO(dcarney): is there a better way to do this?
      i::Object** unsafe = reinterpret_cast<i::Object**>(*ctx[i]);
      *unsafe = CcTest::heap()->undefined_value();
      ctx[i].Clear();
  
      // Scavenge treats these references as strong.
      for (int j = 0; j < 10; j++) {
        CcTest::heap()->CollectGarbage(i::NEW_SPACE);
        CHECK_EQ(kNumTestContexts - i, CountNativeContexts());
      }
  
      // Mark compact handles the weak references.
      CcTest::heap()->CollectAllGarbage();
      CHECK_EQ(kNumTestContexts - i - 1, CountNativeContexts());
    }
  
    CHECK_EQ(0, CountNativeContexts());
  }
  
  
  // Count the number of native contexts in the weak list of native contexts
  // causing a GC after the specified number of elements.
  static int CountNativeContextsWithGC(Isolate* isolate, int n) {
    Heap* heap = isolate->heap();
    int count = 0;
    Handle<Object> object(heap->native_contexts_list(), isolate);
    while (!object->IsUndefined(isolate)) {
      count++;
      if (count == n) heap->CollectAllGarbage();
      object =
          Handle<Object>(Context::cast(*object)->next_context_link(), isolate);
    }
    return count;
  }
  
  
  // Count the number of user functions in the weak list of optimized
  // functions attached to a native context causing a GC after the
  // specified number of elements.
  static int CountOptimizedUserFunctionsWithGC(v8::Local<v8::Context> context,
                                               int n) {
    int count = 0;
    Handle<Context> icontext = v8::Utils::OpenHandle(*context);
    Isolate* isolate = icontext->GetIsolate();
    Handle<Object> object(icontext->get(Context::OPTIMIZED_FUNCTIONS_LIST),
                          isolate);
    while (object->IsJSFunction() &&
           !Handle<JSFunction>::cast(object)->shared()->IsBuiltin()) {
      count++;
      if (count == n) isolate->heap()->CollectAllGarbage();
      object = Handle<Object>(
          Object::cast(JSFunction::cast(*object)->next_function_link()),
          isolate);
    }
    return count;
  }
  
  
  TEST(TestInternalWeakListsTraverseWithGC) {
    FLAG_always_opt = false;
    FLAG_allow_natives_syntax = true;
    v8::V8::Initialize();
  
    static const int kNumTestContexts = 10;
  
    Isolate* isolate = CcTest::i_isolate();
    HandleScope scope(isolate);
    v8::Local<v8::Context> ctx[kNumTestContexts];
    if (!isolate->use_crankshaft()) return;
  
    CHECK_EQ(0, CountNativeContexts());
  
    // Create an number of contexts and check the length of the weak list both
    // with and without GCs while iterating the list.
    for (int i = 0; i < kNumTestContexts; i++) {
      ctx[i] = v8::Context::New(CcTest::isolate());
      CHECK_EQ(i + 1, CountNativeContexts());
      CHECK_EQ(i + 1, CountNativeContextsWithGC(isolate, i / 2 + 1));
    }
  
    ctx[0]->Enter();
  
    // Compile a number of functions the length of the weak list of optimized
    // functions both with and without GCs while iterating the list.
    CHECK_EQ(0, CountOptimizedUserFunctions(ctx[0]));
    OptimizeEmptyFunction("f1");
    CHECK_EQ(1, CountOptimizedUserFunctions(ctx[0]));
    CHECK_EQ(1, CountOptimizedUserFunctionsWithGC(ctx[0], 1));
    OptimizeEmptyFunction("f2");
    CHECK_EQ(2, CountOptimizedUserFunctions(ctx[0]));
    CHECK_EQ(2, CountOptimizedUserFunctionsWithGC(ctx[0], 1));
    OptimizeEmptyFunction("f3");
    CHECK_EQ(3, CountOptimizedUserFunctions(ctx[0]));
    CHECK_EQ(3, CountOptimizedUserFunctionsWithGC(ctx[0], 1));
    OptimizeEmptyFunction("f4");
    CHECK_EQ(4, CountOptimizedUserFunctions(ctx[0]));
    CHECK_EQ(4, CountOptimizedUserFunctionsWithGC(ctx[0], 2));
    OptimizeEmptyFunction("f5");
    CHECK_EQ(5, CountOptimizedUserFunctions(ctx[0]));
    CHECK_EQ(5, CountOptimizedUserFunctionsWithGC(ctx[0], 4));
  
    ctx[0]->Exit();
  }
  
  
  TEST(TestSizeOfRegExpCode) {
    if (!FLAG_regexp_optimization) return;
  
    v8::V8::Initialize();
  
    Isolate* isolate = CcTest::i_isolate();
    HandleScope scope(isolate);
  
    LocalContext context;
  
    // Adjust source below and this check to match
    // RegExpImple::kRegExpTooLargeToOptimize.
    CHECK_EQ(i::RegExpImpl::kRegExpTooLargeToOptimize, 20 * KB);
  
    // Compile a regexp that is much larger if we are using regexp optimizations.
    CompileRun(
        "var reg_exp_source = '(?:a|bc|def|ghij|klmno|pqrstu)';"
        "var half_size_reg_exp;"
        "while (reg_exp_source.length < 20 * 1024) {"
        "  half_size_reg_exp = reg_exp_source;"
        "  reg_exp_source = reg_exp_source + reg_exp_source;"
        "}"
        // Flatten string.
        "reg_exp_source.match(/f/);");
  
    // Get initial heap size after several full GCs, which will stabilize
    // the heap size and return with sweeping finished completely.
    CcTest::heap()->CollectAllGarbage();
    CcTest::heap()->CollectAllGarbage();
    CcTest::heap()->CollectAllGarbage();
    CcTest::heap()->CollectAllGarbage();
    CcTest::heap()->CollectAllGarbage();
    MarkCompactCollector* collector = CcTest::heap()->mark_compact_collector();
    if (collector->sweeping_in_progress()) {
      collector->EnsureSweepingCompleted();
    }
    int initial_size = static_cast<int>(CcTest::heap()->SizeOfObjects());
  
    CompileRun("'foo'.match(reg_exp_source);");
    CcTest::heap()->CollectAllGarbage();
    int size_with_regexp = static_cast<int>(CcTest::heap()->SizeOfObjects());
  
    CompileRun("'foo'.match(half_size_reg_exp);");
    CcTest::heap()->CollectAllGarbage();
    int size_with_optimized_regexp =
        static_cast<int>(CcTest::heap()->SizeOfObjects());
  
    int size_of_regexp_code = size_with_regexp - initial_size;
  
    // On some platforms the debug-code flag causes huge amounts of regexp code
    // to be emitted, breaking this test.
    if (!FLAG_debug_code) {
      CHECK_LE(size_of_regexp_code, 1 * MB);
    }
  
    // Small regexp is half the size, but compiles to more than twice the code
    // due to the optimization steps.
    CHECK_GE(size_with_optimized_regexp,
             size_with_regexp + size_of_regexp_code * 2);
  }
  
  
  HEAP_TEST(TestSizeOfObjects) {
    v8::V8::Initialize();
  
    // Get initial heap size after several full GCs, which will stabilize
    // the heap size and return with sweeping finished completely.
    CcTest::heap()->CollectAllGarbage();
    CcTest::heap()->CollectAllGarbage();
    CcTest::heap()->CollectAllGarbage();
    CcTest::heap()->CollectAllGarbage();
    CcTest::heap()->CollectAllGarbage();
    MarkCompactCollector* collector = CcTest::heap()->mark_compact_collector();
    if (collector->sweeping_in_progress()) {
      collector->EnsureSweepingCompleted();
    }
    int initial_size = static_cast<int>(CcTest::heap()->SizeOfObjects());
  
    {
      // Allocate objects on several different old-space pages so that
      // concurrent sweeper threads will be busy sweeping the old space on
      // subsequent GC runs.
      AlwaysAllocateScope always_allocate(CcTest::i_isolate());
      int filler_size = static_cast<int>(FixedArray::SizeFor(8192));
      for (int i = 1; i <= 100; i++) {
        CcTest::heap()->AllocateFixedArray(8192, TENURED).ToObjectChecked();
        CHECK_EQ(initial_size + i * filler_size,
                 static_cast<int>(CcTest::heap()->SizeOfObjects()));
      }
    }
  
    // The heap size should go back to initial size after a full GC, even
    // though sweeping didn't finish yet.
    CcTest::heap()->CollectAllGarbage();
  
    // Normally sweeping would not be complete here, but no guarantees.
  
    CHECK_EQ(initial_size, static_cast<int>(CcTest::heap()->SizeOfObjects()));
  
    // Waiting for sweeper threads should not change heap size.
    if (collector->sweeping_in_progress()) {
      collector->EnsureSweepingCompleted();
    }
    CHECK_EQ(initial_size, static_cast<int>(CcTest::heap()->SizeOfObjects()));
  }
  
  
  TEST(TestAlignmentCalculations) {
    // Maximum fill amounts are consistent.
    int maximum_double_misalignment = kDoubleSize - kPointerSize;
    int maximum_simd128_misalignment = kSimd128Size - kPointerSize;
    int max_word_fill = Heap::GetMaximumFillToAlign(kWordAligned);
    CHECK_EQ(0, max_word_fill);
    int max_double_fill = Heap::GetMaximumFillToAlign(kDoubleAligned);
    CHECK_EQ(maximum_double_misalignment, max_double_fill);
    int max_double_unaligned_fill = Heap::GetMaximumFillToAlign(kDoubleUnaligned);
    CHECK_EQ(maximum_double_misalignment, max_double_unaligned_fill);
    int max_simd128_unaligned_fill =
        Heap::GetMaximumFillToAlign(kSimd128Unaligned);
    CHECK_EQ(maximum_simd128_misalignment, max_simd128_unaligned_fill);
  
    Address base = static_cast<Address>(NULL);
    int fill = 0;
  
    // Word alignment never requires fill.
    fill = Heap::GetFillToAlign(base, kWordAligned);
    CHECK_EQ(0, fill);
    fill = Heap::GetFillToAlign(base + kPointerSize, kWordAligned);
    CHECK_EQ(0, fill);
  
    // No fill is required when address is double aligned.
    fill = Heap::GetFillToAlign(base, kDoubleAligned);
    CHECK_EQ(0, fill);
    // Fill is required if address is not double aligned.
    fill = Heap::GetFillToAlign(base + kPointerSize, kDoubleAligned);
    CHECK_EQ(maximum_double_misalignment, fill);
    // kDoubleUnaligned has the opposite fill amounts.
    fill = Heap::GetFillToAlign(base, kDoubleUnaligned);
    CHECK_EQ(maximum_double_misalignment, fill);
    fill = Heap::GetFillToAlign(base + kPointerSize, kDoubleUnaligned);
    CHECK_EQ(0, fill);
  
    // 128 bit SIMD types have 2 or 4 possible alignments, depending on platform.
    fill = Heap::GetFillToAlign(base, kSimd128Unaligned);
    CHECK_EQ((3 * kPointerSize) & kSimd128AlignmentMask, fill);
    fill = Heap::GetFillToAlign(base + kPointerSize, kSimd128Unaligned);
    CHECK_EQ((2 * kPointerSize) & kSimd128AlignmentMask, fill);
    fill = Heap::GetFillToAlign(base + 2 * kPointerSize, kSimd128Unaligned);
    CHECK_EQ(kPointerSize, fill);
    fill = Heap::GetFillToAlign(base + 3 * kPointerSize, kSimd128Unaligned);
    CHECK_EQ(0, fill);
  }
  
  
  static HeapObject* NewSpaceAllocateAligned(int size,
                                             AllocationAlignment alignment) {
    Heap* heap = CcTest::heap();
    AllocationResult allocation =
        heap->new_space()->AllocateRawAligned(size, alignment);
    HeapObject* obj = NULL;
    allocation.To(&obj);
    heap->CreateFillerObjectAt(obj->address(), size, ClearRecordedSlots::kNo);
    return obj;
  }
  
  
  // Get new space allocation into the desired alignment.
  static Address AlignNewSpace(AllocationAlignment alignment, int offset) {
    Address* top_addr = CcTest::heap()->new_space()->allocation_top_address();
    int fill = Heap::GetFillToAlign(*top_addr, alignment);
    if (fill) {
      NewSpaceAllocateAligned(fill + offset, kWordAligned);
    }
    return *top_addr;
  }
  
  
  TEST(TestAlignedAllocation) {
    // Double misalignment is 4 on 32-bit platforms, 0 on 64-bit ones.
    const intptr_t double_misalignment = kDoubleSize - kPointerSize;
    Address* top_addr = CcTest::heap()->new_space()->allocation_top_address();
    Address start;
    HeapObject* obj;
    HeapObject* filler;
    if (double_misalignment) {
      // Allocate a pointer sized object that must be double aligned at an
      // aligned address.
      start = AlignNewSpace(kDoubleAligned, 0);
      obj = NewSpaceAllocateAligned(kPointerSize, kDoubleAligned);
      CHECK(IsAddressAligned(obj->address(), kDoubleAlignment));
      // There is no filler.
      CHECK_EQ(kPointerSize, *top_addr - start);
  
      // Allocate a second pointer sized object that must be double aligned at an
      // unaligned address.
      start = AlignNewSpace(kDoubleAligned, kPointerSize);
      obj = NewSpaceAllocateAligned(kPointerSize, kDoubleAligned);
      CHECK(IsAddressAligned(obj->address(), kDoubleAlignment));
      // There is a filler object before the object.
      filler = HeapObject::FromAddress(start);
      CHECK(obj != filler && filler->IsFiller() &&
            filler->Size() == kPointerSize);
      CHECK_EQ(kPointerSize + double_misalignment, *top_addr - start);
  
      // Similarly for kDoubleUnaligned.
      start = AlignNewSpace(kDoubleUnaligned, 0);
      obj = NewSpaceAllocateAligned(kPointerSize, kDoubleUnaligned);
      CHECK(IsAddressAligned(obj->address(), kDoubleAlignment, kPointerSize));
      CHECK_EQ(kPointerSize, *top_addr - start);
      start = AlignNewSpace(kDoubleUnaligned, kPointerSize);
      obj = NewSpaceAllocateAligned(kPointerSize, kDoubleUnaligned);
      CHECK(IsAddressAligned(obj->address(), kDoubleAlignment, kPointerSize));
      // There is a filler object before the object.
      filler = HeapObject::FromAddress(start);
      CHECK(obj != filler && filler->IsFiller() &&
            filler->Size() == kPointerSize);
      CHECK_EQ(kPointerSize + double_misalignment, *top_addr - start);
    }
  
    // Now test SIMD alignment. There are 2 or 4 possible alignments, depending
    // on platform.
    start = AlignNewSpace(kSimd128Unaligned, 0);
    obj = NewSpaceAllocateAligned(kPointerSize, kSimd128Unaligned);
    CHECK(IsAddressAligned(obj->address(), kSimd128Alignment, kPointerSize));
    // There is no filler.
    CHECK_EQ(kPointerSize, *top_addr - start);
    start = AlignNewSpace(kSimd128Unaligned, kPointerSize);
    obj = NewSpaceAllocateAligned(kPointerSize, kSimd128Unaligned);
    CHECK(IsAddressAligned(obj->address(), kSimd128Alignment, kPointerSize));
    // There is a filler object before the object.
    filler = HeapObject::FromAddress(start);
    CHECK(obj != filler && filler->IsFiller() &&
          filler->Size() == kSimd128Size - kPointerSize);
    CHECK_EQ(kPointerSize + kSimd128Size - kPointerSize, *top_addr - start);
  
    if (double_misalignment) {
      // Test the 2 other alignments possible on 32 bit platforms.
      start = AlignNewSpace(kSimd128Unaligned, 2 * kPointerSize);
      obj = NewSpaceAllocateAligned(kPointerSize, kSimd128Unaligned);
      CHECK(IsAddressAligned(obj->address(), kSimd128Alignment, kPointerSize));
      // There is a filler object before the object.
      filler = HeapObject::FromAddress(start);
      CHECK(obj != filler && filler->IsFiller() &&
            filler->Size() == 2 * kPointerSize);
      CHECK_EQ(kPointerSize + 2 * kPointerSize, *top_addr - start);
      start = AlignNewSpace(kSimd128Unaligned, 3 * kPointerSize);
      obj = NewSpaceAllocateAligned(kPointerSize, kSimd128Unaligned);
      CHECK(IsAddressAligned(obj->address(), kSimd128Alignment, kPointerSize));
      // There is a filler object before the object.
      filler = HeapObject::FromAddress(start);
      CHECK(obj != filler && filler->IsFiller() &&
            filler->Size() == kPointerSize);
      CHECK_EQ(kPointerSize + kPointerSize, *top_addr - start);
    }
  }
  
  
  static HeapObject* OldSpaceAllocateAligned(int size,
                                             AllocationAlignment alignment) {
    Heap* heap = CcTest::heap();
    AllocationResult allocation =
        heap->old_space()->AllocateRawAligned(size, alignment);
    HeapObject* obj = NULL;
    allocation.To(&obj);
    heap->CreateFillerObjectAt(obj->address(), size, ClearRecordedSlots::kNo);
    return obj;
  }
  
  
  // Get old space allocation into the desired alignment.
  static Address AlignOldSpace(AllocationAlignment alignment, int offset) {
    Address* top_addr = CcTest::heap()->old_space()->allocation_top_address();
    int fill = Heap::GetFillToAlign(*top_addr, alignment);
    int allocation = fill + offset;
    if (allocation) {
      OldSpaceAllocateAligned(allocation, kWordAligned);
    }
    Address top = *top_addr;
    // Now force the remaining allocation onto the free list.
    CcTest::heap()->old_space()->EmptyAllocationInfo();
    return top;
  }
  
  
  // Test the case where allocation must be done from the free list, so filler
  // may precede or follow the object.
  TEST(TestAlignedOverAllocation) {
    // Double misalignment is 4 on 32-bit platforms, 0 on 64-bit ones.
    const intptr_t double_misalignment = kDoubleSize - kPointerSize;
    Address start;
    HeapObject* obj;
    HeapObject* filler1;
    HeapObject* filler2;
    if (double_misalignment) {
      start = AlignOldSpace(kDoubleAligned, 0);
      obj = OldSpaceAllocateAligned(kPointerSize, kDoubleAligned);
      // The object is aligned, and a filler object is created after.
      CHECK(IsAddressAligned(obj->address(), kDoubleAlignment));
      filler1 = HeapObject::FromAddress(start + kPointerSize);
      CHECK(obj != filler1 && filler1->IsFiller() &&
            filler1->Size() == kPointerSize);
      // Try the opposite alignment case.
      start = AlignOldSpace(kDoubleAligned, kPointerSize);
      obj = OldSpaceAllocateAligned(kPointerSize, kDoubleAligned);
      CHECK(IsAddressAligned(obj->address(), kDoubleAlignment));
      filler1 = HeapObject::FromAddress(start);
      CHECK(obj != filler1);
      CHECK(filler1->IsFiller());
      CHECK(filler1->Size() == kPointerSize);
      CHECK(obj != filler1 && filler1->IsFiller() &&
            filler1->Size() == kPointerSize);
  
      // Similarly for kDoubleUnaligned.
      start = AlignOldSpace(kDoubleUnaligned, 0);
      obj = OldSpaceAllocateAligned(kPointerSize, kDoubleUnaligned);
      // The object is aligned, and a filler object is created after.
      CHECK(IsAddressAligned(obj->address(), kDoubleAlignment, kPointerSize));
      filler1 = HeapObject::FromAddress(start + kPointerSize);
      CHECK(obj != filler1 && filler1->IsFiller() &&
            filler1->Size() == kPointerSize);
      // Try the opposite alignment case.
      start = AlignOldSpace(kDoubleUnaligned, kPointerSize);
      obj = OldSpaceAllocateAligned(kPointerSize, kDoubleUnaligned);
      CHECK(IsAddressAligned(obj->address(), kDoubleAlignment, kPointerSize));
      filler1 = HeapObject::FromAddress(start);
      CHECK(obj != filler1 && filler1->IsFiller() &&
            filler1->Size() == kPointerSize);
    }
  
    // Now test SIMD alignment. There are 2 or 4 possible alignments, depending
    // on platform.
    start = AlignOldSpace(kSimd128Unaligned, 0);
    obj = OldSpaceAllocateAligned(kPointerSize, kSimd128Unaligned);
    CHECK(IsAddressAligned(obj->address(), kSimd128Alignment, kPointerSize));
    // There is a filler object after the object.
    filler1 = HeapObject::FromAddress(start + kPointerSize);
    CHECK(obj != filler1 && filler1->IsFiller() &&
          filler1->Size() == kSimd128Size - kPointerSize);
    start = AlignOldSpace(kSimd128Unaligned, kPointerSize);
    obj = OldSpaceAllocateAligned(kPointerSize, kSimd128Unaligned);
    CHECK(IsAddressAligned(obj->address(), kSimd128Alignment, kPointerSize));
    // There is a filler object before the object.
    filler1 = HeapObject::FromAddress(start);
    CHECK(obj != filler1 && filler1->IsFiller() &&
          filler1->Size() == kSimd128Size - kPointerSize);
  
    if (double_misalignment) {
      // Test the 2 other alignments possible on 32 bit platforms.
      start = AlignOldSpace(kSimd128Unaligned, 2 * kPointerSize);
      obj = OldSpaceAllocateAligned(kPointerSize, kSimd128Unaligned);
      CHECK(IsAddressAligned(obj->address(), kSimd128Alignment, kPointerSize));
      // There are filler objects before and after the object.
      filler1 = HeapObject::FromAddress(start);
      CHECK(obj != filler1 && filler1->IsFiller() &&
            filler1->Size() == 2 * kPointerSize);
      filler2 = HeapObject::FromAddress(start + 3 * kPointerSize);
      CHECK(obj != filler2 && filler2->IsFiller() &&
            filler2->Size() == kPointerSize);
      start = AlignOldSpace(kSimd128Unaligned, 3 * kPointerSize);
      obj = OldSpaceAllocateAligned(kPointerSize, kSimd128Unaligned);
      CHECK(IsAddressAligned(obj->address(), kSimd128Alignment, kPointerSize));
      // There are filler objects before and after the object.
      filler1 = HeapObject::FromAddress(start);
      CHECK(obj != filler1 && filler1->IsFiller() &&
            filler1->Size() == kPointerSize);
      filler2 = HeapObject::FromAddress(start + 2 * kPointerSize);
      CHECK(obj != filler2 && filler2->IsFiller() &&
            filler2->Size() == 2 * kPointerSize);
    }
  }
  
  
  TEST(TestSizeOfObjectsVsHeapIteratorPrecision) {
    CcTest::InitializeVM();
    HeapIterator iterator(CcTest::heap());
    intptr_t size_of_objects_1 = CcTest::heap()->SizeOfObjects();
    intptr_t size_of_objects_2 = 0;
    for (HeapObject* obj = iterator.next();
         obj != NULL;
         obj = iterator.next()) {
      if (!obj->IsFreeSpace()) {
        size_of_objects_2 += obj->Size();
      }
    }
    // Delta must be within 5% of the larger result.
    // TODO(gc): Tighten this up by distinguishing between byte
    // arrays that are real and those that merely mark free space
    // on the heap.
    if (size_of_objects_1 > size_of_objects_2) {
      intptr_t delta = size_of_objects_1 - size_of_objects_2;
      PrintF("Heap::SizeOfObjects: %" V8PRIdPTR
             ", "
             "Iterator: %" V8PRIdPTR
             ", "
             "delta: %" V8PRIdPTR "\n",
             size_of_objects_1, size_of_objects_2, delta);
      CHECK_GT(size_of_objects_1 / 20, delta);
    } else {
      intptr_t delta = size_of_objects_2 - size_of_objects_1;
      PrintF("Heap::SizeOfObjects: %" V8PRIdPTR
             ", "
             "Iterator: %" V8PRIdPTR
             ", "
             "delta: %" V8PRIdPTR "\n",
             size_of_objects_1, size_of_objects_2, delta);
      CHECK_GT(size_of_objects_2 / 20, delta);
    }
  }
  
  
  static void FillUpNewSpace(NewSpace* new_space) {
    // Fill up new space to the point that it is completely full. Make sure
    // that the scavenger does not undo the filling.
    Heap* heap = new_space->heap();
    Isolate* isolate = heap->isolate();
    Factory* factory = isolate->factory();
    HandleScope scope(isolate);
    AlwaysAllocateScope always_allocate(isolate);
    intptr_t available = new_space->Capacity() - new_space->Size();
    intptr_t number_of_fillers = (available / FixedArray::SizeFor(32)) - 1;
    for (intptr_t i = 0; i < number_of_fillers; i++) {
      CHECK(heap->InNewSpace(*factory->NewFixedArray(32, NOT_TENURED)));
    }
  }
  
  
  TEST(GrowAndShrinkNewSpace) {
    CcTest::InitializeVM();
    Heap* heap = CcTest::heap();
    NewSpace* new_space = heap->new_space();
  
    if (heap->MaxSemiSpaceSize() == heap->InitialSemiSpaceSize()) {
      return;
    }
  
    // Explicitly growing should double the space capacity.
    intptr_t old_capacity, new_capacity;
    old_capacity = new_space->TotalCapacity();
    new_space->Grow();
    new_capacity = new_space->TotalCapacity();
    CHECK(2 * old_capacity == new_capacity);
  
    old_capacity = new_space->TotalCapacity();
    FillUpNewSpace(new_space);
    new_capacity = new_space->TotalCapacity();
    CHECK(old_capacity == new_capacity);
  
    // Explicitly shrinking should not affect space capacity.
    old_capacity = new_space->TotalCapacity();
    new_space->Shrink();
    new_capacity = new_space->TotalCapacity();
    CHECK(old_capacity == new_capacity);
  
    // Let the scavenger empty the new space.
    heap->CollectGarbage(NEW_SPACE);
    CHECK_LE(new_space->Size(), old_capacity);
  
    // Explicitly shrinking should halve the space capacity.
    old_capacity = new_space->TotalCapacity();
    new_space->Shrink();
    new_capacity = new_space->TotalCapacity();
    CHECK(old_capacity == 2 * new_capacity);
  
    // Consecutive shrinking should not affect space capacity.
    old_capacity = new_space->TotalCapacity();
    new_space->Shrink();
    new_space->Shrink();
    new_space->Shrink();
    new_capacity = new_space->TotalCapacity();
    CHECK(old_capacity == new_capacity);
  }
  
  
  TEST(CollectingAllAvailableGarbageShrinksNewSpace) {
    CcTest::InitializeVM();
    Heap* heap = CcTest::heap();
    if (heap->MaxSemiSpaceSize() == heap->InitialSemiSpaceSize()) {
      return;
    }
  
    v8::HandleScope scope(CcTest::isolate());
    NewSpace* new_space = heap->new_space();
    intptr_t old_capacity, new_capacity;
    old_capacity = new_space->TotalCapacity();
    new_space->Grow();
    new_capacity = new_space->TotalCapacity();
    CHECK(2 * old_capacity == new_capacity);
    FillUpNewSpace(new_space);
    heap->CollectAllAvailableGarbage();
    new_capacity = new_space->TotalCapacity();
    CHECK(old_capacity == new_capacity);
  }
  
  
  static int NumberOfGlobalObjects() {
    int count = 0;
    HeapIterator iterator(CcTest::heap());
    for (HeapObject* obj = iterator.next(); obj != NULL; obj = iterator.next()) {
      if (obj->IsJSGlobalObject()) count++;
    }
    return count;
  }
  
  
  // Test that we don't embed maps from foreign contexts into
  // optimized code.
  TEST(LeakNativeContextViaMap) {
    i::FLAG_allow_natives_syntax = true;
    v8::Isolate* isolate = CcTest::isolate();
    v8::HandleScope outer_scope(isolate);
    v8::Persistent<v8::Context> ctx1p;
    v8::Persistent<v8::Context> ctx2p;
    {
      v8::HandleScope scope(isolate);
      ctx1p.Reset(isolate, v8::Context::New(isolate));
      ctx2p.Reset(isolate, v8::Context::New(isolate));
      v8::Local<v8::Context>::New(isolate, ctx1p)->Enter();
    }
  
    CcTest::heap()->CollectAllAvailableGarbage();
    CHECK_EQ(2, NumberOfGlobalObjects());
  
    {
      v8::HandleScope inner_scope(isolate);
      CompileRun("var v = {x: 42}");
      v8::Local<v8::Context> ctx1 = v8::Local<v8::Context>::New(isolate, ctx1p);
      v8::Local<v8::Context> ctx2 = v8::Local<v8::Context>::New(isolate, ctx2p);
      v8::Local<v8::Value> v =
          ctx1->Global()->Get(ctx1, v8_str("v")).ToLocalChecked();
      ctx2->Enter();
      CHECK(ctx2->Global()->Set(ctx2, v8_str("o"), v).FromJust());
      v8::Local<v8::Value> res = CompileRun(
          "function f() { return o.x; }"
          "for (var i = 0; i < 10; ++i) f();"
          "%OptimizeFunctionOnNextCall(f);"
          "f();");
      CHECK_EQ(42, res->Int32Value(ctx2).FromJust());
      CHECK(ctx2->Global()
                ->Set(ctx2, v8_str("o"), v8::Int32::New(isolate, 0))
                .FromJust());
      ctx2->Exit();
      v8::Local<v8::Context>::New(isolate, ctx1)->Exit();
      ctx1p.Reset();
      isolate->ContextDisposedNotification();
    }
    CcTest::heap()->CollectAllAvailableGarbage();
    CHECK_EQ(1, NumberOfGlobalObjects());
    ctx2p.Reset();
    CcTest::heap()->CollectAllAvailableGarbage();
    CHECK_EQ(0, NumberOfGlobalObjects());
  }
  
  
  // Test that we don't embed functions from foreign contexts into
  // optimized code.
  TEST(LeakNativeContextViaFunction) {
    i::FLAG_allow_natives_syntax = true;
    v8::Isolate* isolate = CcTest::isolate();
    v8::HandleScope outer_scope(isolate);
    v8::Persistent<v8::Context> ctx1p;
    v8::Persistent<v8::Context> ctx2p;
    {
      v8::HandleScope scope(isolate);
      ctx1p.Reset(isolate, v8::Context::New(isolate));
      ctx2p.Reset(isolate, v8::Context::New(isolate));
      v8::Local<v8::Context>::New(isolate, ctx1p)->Enter();
    }
  
    CcTest::heap()->CollectAllAvailableGarbage();
    CHECK_EQ(2, NumberOfGlobalObjects());
  
    {
      v8::HandleScope inner_scope(isolate);
      CompileRun("var v = function() { return 42; }");
      v8::Local<v8::Context> ctx1 = v8::Local<v8::Context>::New(isolate, ctx1p);
      v8::Local<v8::Context> ctx2 = v8::Local<v8::Context>::New(isolate, ctx2p);
      v8::Local<v8::Value> v =
          ctx1->Global()->Get(ctx1, v8_str("v")).ToLocalChecked();
      ctx2->Enter();
      CHECK(ctx2->Global()->Set(ctx2, v8_str("o"), v).FromJust());
      v8::Local<v8::Value> res = CompileRun(
          "function f(x) { return x(); }"
          "for (var i = 0; i < 10; ++i) f(o);"
          "%OptimizeFunctionOnNextCall(f);"
          "f(o);");
      CHECK_EQ(42, res->Int32Value(ctx2).FromJust());
      CHECK(ctx2->Global()
                ->Set(ctx2, v8_str("o"), v8::Int32::New(isolate, 0))
                .FromJust());
      ctx2->Exit();
      ctx1->Exit();
      ctx1p.Reset();
      isolate->ContextDisposedNotification();
    }
    CcTest::heap()->CollectAllAvailableGarbage();
    CHECK_EQ(1, NumberOfGlobalObjects());
    ctx2p.Reset();
    CcTest::heap()->CollectAllAvailableGarbage();
    CHECK_EQ(0, NumberOfGlobalObjects());
  }
  
  
  TEST(LeakNativeContextViaMapKeyed) {
    i::FLAG_allow_natives_syntax = true;
    v8::Isolate* isolate = CcTest::isolate();
    v8::HandleScope outer_scope(isolate);
    v8::Persistent<v8::Context> ctx1p;
    v8::Persistent<v8::Context> ctx2p;
    {
      v8::HandleScope scope(isolate);
      ctx1p.Reset(isolate, v8::Context::New(isolate));
      ctx2p.Reset(isolate, v8::Context::New(isolate));
      v8::Local<v8::Context>::New(isolate, ctx1p)->Enter();
    }
  
    CcTest::heap()->CollectAllAvailableGarbage();
    CHECK_EQ(2, NumberOfGlobalObjects());
  
    {
      v8::HandleScope inner_scope(isolate);
      CompileRun("var v = [42, 43]");
      v8::Local<v8::Context> ctx1 = v8::Local<v8::Context>::New(isolate, ctx1p);
      v8::Local<v8::Context> ctx2 = v8::Local<v8::Context>::New(isolate, ctx2p);
      v8::Local<v8::Value> v =
          ctx1->Global()->Get(ctx1, v8_str("v")).ToLocalChecked();
      ctx2->Enter();
      CHECK(ctx2->Global()->Set(ctx2, v8_str("o"), v).FromJust());
      v8::Local<v8::Value> res = CompileRun(
          "function f() { return o[0]; }"
          "for (var i = 0; i < 10; ++i) f();"
          "%OptimizeFunctionOnNextCall(f);"
          "f();");
      CHECK_EQ(42, res->Int32Value(ctx2).FromJust());
      CHECK(ctx2->Global()
                ->Set(ctx2, v8_str("o"), v8::Int32::New(isolate, 0))
                .FromJust());
      ctx2->Exit();
      ctx1->Exit();
      ctx1p.Reset();
      isolate->ContextDisposedNotification();
    }
    CcTest::heap()->CollectAllAvailableGarbage();
    CHECK_EQ(1, NumberOfGlobalObjects());
    ctx2p.Reset();
    CcTest::heap()->CollectAllAvailableGarbage();
    CHECK_EQ(0, NumberOfGlobalObjects());
  }
  
  
  TEST(LeakNativeContextViaMapProto) {
    i::FLAG_allow_natives_syntax = true;
    v8::Isolate* isolate = CcTest::isolate();
    v8::HandleScope outer_scope(isolate);
    v8::Persistent<v8::Context> ctx1p;
    v8::Persistent<v8::Context> ctx2p;
    {
      v8::HandleScope scope(isolate);
      ctx1p.Reset(isolate, v8::Context::New(isolate));
      ctx2p.Reset(isolate, v8::Context::New(isolate));
      v8::Local<v8::Context>::New(isolate, ctx1p)->Enter();
    }
  
    CcTest::heap()->CollectAllAvailableGarbage();
    CHECK_EQ(2, NumberOfGlobalObjects());
  
    {
      v8::HandleScope inner_scope(isolate);
      CompileRun("var v = { y: 42}");
      v8::Local<v8::Context> ctx1 = v8::Local<v8::Context>::New(isolate, ctx1p);
      v8::Local<v8::Context> ctx2 = v8::Local<v8::Context>::New(isolate, ctx2p);
      v8::Local<v8::Value> v =
          ctx1->Global()->Get(ctx1, v8_str("v")).ToLocalChecked();
      ctx2->Enter();
      CHECK(ctx2->Global()->Set(ctx2, v8_str("o"), v).FromJust());
      v8::Local<v8::Value> res = CompileRun(
          "function f() {"
          "  var p = {x: 42};"
          "  p.__proto__ = o;"
          "  return p.x;"
          "}"
          "for (var i = 0; i < 10; ++i) f();"
          "%OptimizeFunctionOnNextCall(f);"
          "f();");
      CHECK_EQ(42, res->Int32Value(ctx2).FromJust());
      CHECK(ctx2->Global()
                ->Set(ctx2, v8_str("o"), v8::Int32::New(isolate, 0))
                .FromJust());
      ctx2->Exit();
      ctx1->Exit();
      ctx1p.Reset();
      isolate->ContextDisposedNotification();
    }
    CcTest::heap()->CollectAllAvailableGarbage();
    CHECK_EQ(1, NumberOfGlobalObjects());
    ctx2p.Reset();
    CcTest::heap()->CollectAllAvailableGarbage();
    CHECK_EQ(0, NumberOfGlobalObjects());
  }
  
  
  TEST(InstanceOfStubWriteBarrier) {
    i::FLAG_allow_natives_syntax = true;
  #ifdef VERIFY_HEAP
    i::FLAG_verify_heap = true;
  #endif
  
    CcTest::InitializeVM();
    if (!CcTest::i_isolate()->use_crankshaft()) return;
    if (i::FLAG_force_marking_deque_overflows) return;
    v8::HandleScope outer_scope(CcTest::isolate());
    v8::Local<v8::Context> ctx = CcTest::isolate()->GetCurrentContext();
  
    {
      v8::HandleScope scope(CcTest::isolate());
      CompileRun(
          "function foo () { }"
          "function mkbar () { return new (new Function(\"\")) (); }"
          "function f (x) { return (x instanceof foo); }"
          "function g () { f(mkbar()); }"
          "f(new foo()); f(new foo());"
          "%OptimizeFunctionOnNextCall(f);"
          "f(new foo()); g();");
    }
  
    IncrementalMarking* marking = CcTest::heap()->incremental_marking();
    marking->Stop();
    CcTest::heap()->StartIncrementalMarking();
  
    i::Handle<JSFunction> f = i::Handle<JSFunction>::cast(
        v8::Utils::OpenHandle(*v8::Local<v8::Function>::Cast(
            CcTest::global()->Get(ctx, v8_str("f")).ToLocalChecked())));
  
    CHECK(f->IsOptimized());
  
    while (!Marking::IsBlack(ObjectMarking::MarkBitFrom(f->code())) &&
           !marking->IsStopped()) {
      // Discard any pending GC requests otherwise we will get GC when we enter
      // code below.
      marking->Step(MB, IncrementalMarking::NO_GC_VIA_STACK_GUARD);
    }
  
    CHECK(marking->IsMarking());
  
    {
      v8::HandleScope scope(CcTest::isolate());
      v8::Local<v8::Object> global = CcTest::global();
      v8::Local<v8::Function> g = v8::Local<v8::Function>::Cast(
          global->Get(ctx, v8_str("g")).ToLocalChecked());
      g->Call(ctx, global, 0, nullptr).ToLocalChecked();
    }
  
    CcTest::heap()->incremental_marking()->set_should_hurry(true);
    CcTest::heap()->CollectGarbage(OLD_SPACE);
  }
  
  namespace {
  
  int GetProfilerTicks(SharedFunctionInfo* shared) {
    return FLAG_ignition ? shared->profiler_ticks()
                         : shared->code()->profiler_ticks();
  }
  
  }  // namespace
  
  TEST(ResetSharedFunctionInfoCountersDuringIncrementalMarking) {
    i::FLAG_stress_compaction = false;
    i::FLAG_allow_natives_syntax = true;
  #ifdef VERIFY_HEAP
    i::FLAG_verify_heap = true;
  #endif
  
    CcTest::InitializeVM();
    if (!CcTest::i_isolate()->use_crankshaft()) return;
    v8::HandleScope outer_scope(CcTest::isolate());
    v8::Local<v8::Context> ctx = CcTest::isolate()->GetCurrentContext();
  
    {
      v8::HandleScope scope(CcTest::isolate());
      CompileRun(
          "function f () {"
          "  var s = 0;"
          "  for (var i = 0; i < 100; i++)  s += i;"
          "  return s;"
          "}"
          "f(); f();"
          "%OptimizeFunctionOnNextCall(f);"
          "f();");
    }
    i::Handle<JSFunction> f = i::Handle<JSFunction>::cast(
        v8::Utils::OpenHandle(*v8::Local<v8::Function>::Cast(
            CcTest::global()->Get(ctx, v8_str("f")).ToLocalChecked())));
    CHECK(f->IsOptimized());
  
    // Make sure incremental marking it not running.
    CcTest::heap()->incremental_marking()->Stop();
  
    CcTest::heap()->StartIncrementalMarking();
    // The following calls will increment CcTest::heap()->global_ic_age().
    CcTest::isolate()->ContextDisposedNotification();
    heap::SimulateIncrementalMarking(CcTest::heap());
    CcTest::heap()->CollectAllGarbage();
  
    CHECK_EQ(CcTest::heap()->global_ic_age(), f->shared()->ic_age());
    CHECK_EQ(0, f->shared()->opt_count());
    CHECK_EQ(0, GetProfilerTicks(f->shared()));
  }
  
  
  TEST(ResetSharedFunctionInfoCountersDuringMarkSweep) {
    i::FLAG_stress_compaction = false;
    i::FLAG_allow_natives_syntax = true;
  #ifdef VERIFY_HEAP
    i::FLAG_verify_heap = true;
  #endif
  
    CcTest::InitializeVM();
    if (!CcTest::i_isolate()->use_crankshaft()) return;
    v8::HandleScope outer_scope(CcTest::isolate());
    v8::Local<v8::Context> ctx = CcTest::isolate()->GetCurrentContext();
  
    {
      v8::HandleScope scope(CcTest::isolate());
      CompileRun(
          "function f () {"
          "  var s = 0;"
          "  for (var i = 0; i < 100; i++)  s += i;"
          "  return s;"
          "}"
          "f(); f();"
          "%OptimizeFunctionOnNextCall(f);"
          "f();");
    }
    i::Handle<JSFunction> f = i::Handle<JSFunction>::cast(
        v8::Utils::OpenHandle(*v8::Local<v8::Function>::Cast(
            CcTest::global()->Get(ctx, v8_str("f")).ToLocalChecked())));
    CHECK(f->IsOptimized());
  
    // Make sure incremental marking it not running.
    CcTest::heap()->incremental_marking()->Stop();
  
    // The following two calls will increment CcTest::heap()->global_ic_age().
    CcTest::isolate()->ContextDisposedNotification();
    CcTest::heap()->CollectAllGarbage();
  
    CHECK_EQ(CcTest::heap()->global_ic_age(), f->shared()->ic_age());
    CHECK_EQ(0, f->shared()->opt_count());
    CHECK_EQ(0, GetProfilerTicks(f->shared()));
  }
  
  
  HEAP_TEST(GCFlags) {
    CcTest::InitializeVM();
    Heap* heap = CcTest::heap();
  
    heap->set_current_gc_flags(Heap::kNoGCFlags);
    CHECK_EQ(Heap::kNoGCFlags, heap->current_gc_flags_);
  
    // Set the flags to check whether we appropriately resets them after the GC.
    heap->set_current_gc_flags(Heap::kAbortIncrementalMarkingMask);
    heap->CollectAllGarbage(Heap::kReduceMemoryFootprintMask);
    CHECK_EQ(Heap::kNoGCFlags, heap->current_gc_flags_);
  
    MarkCompactCollector* collector = heap->mark_compact_collector();
    if (collector->sweeping_in_progress()) {
      collector->EnsureSweepingCompleted();
    }
  
    IncrementalMarking* marking = heap->incremental_marking();
    marking->Stop();
    heap->StartIncrementalMarking(Heap::kReduceMemoryFootprintMask);
    CHECK_NE(0, heap->current_gc_flags_ & Heap::kReduceMemoryFootprintMask);
  
    heap->CollectGarbage(NEW_SPACE);
    // NewSpace scavenges should not overwrite the flags.
    CHECK_NE(0, heap->current_gc_flags_ & Heap::kReduceMemoryFootprintMask);
  
    heap->CollectAllGarbage(Heap::kAbortIncrementalMarkingMask);
    CHECK_EQ(Heap::kNoGCFlags, heap->current_gc_flags_);
  }
  
  
  TEST(IdleNotificationFinishMarking) {
    i::FLAG_allow_natives_syntax = true;
    CcTest::InitializeVM();
    const int initial_gc_count = CcTest::heap()->gc_count();
    heap::SimulateFullSpace(CcTest::heap()->old_space());
    IncrementalMarking* marking = CcTest::heap()->incremental_marking();
    marking->Stop();
    CcTest::heap()->StartIncrementalMarking();
  
    CHECK_EQ(CcTest::heap()->gc_count(), initial_gc_count);
  
    // TODO(hpayer): We cannot write proper unit test right now for heap.
    // The ideal test would call kMaxIdleMarkingDelayCounter to test the
    // marking delay counter.
  
    // Perform a huge incremental marking step but don't complete marking.
    intptr_t bytes_processed = 0;
    do {
      bytes_processed =
          marking->Step(1 * MB, IncrementalMarking::NO_GC_VIA_STACK_GUARD,
                        IncrementalMarking::FORCE_MARKING,
                        IncrementalMarking::DO_NOT_FORCE_COMPLETION);
      CHECK(!marking->IsIdleMarkingDelayCounterLimitReached());
    } while (bytes_processed);
  
    // The next invocations of incremental marking are not going to complete
    // marking
    // since the completion threshold is not reached
    for (size_t i = 0; i < IncrementalMarking::kMaxIdleMarkingDelayCounter - 2;
         i++) {
      marking->Step(1 * MB, IncrementalMarking::NO_GC_VIA_STACK_GUARD,
                    IncrementalMarking::FORCE_MARKING,
                    IncrementalMarking::DO_NOT_FORCE_COMPLETION);
      CHECK(!marking->IsIdleMarkingDelayCounterLimitReached());
    }
  
    marking->SetWeakClosureWasOverApproximatedForTesting(true);
  
    // The next idle notification has to finish incremental marking.
    const double kLongIdleTime = 1000.0;
    CcTest::isolate()->IdleNotificationDeadline(
        (v8::base::TimeTicks::HighResolutionNow().ToInternalValue() /
         static_cast<double>(v8::base::Time::kMicrosecondsPerSecond)) +
        kLongIdleTime);
    CHECK_EQ(CcTest::heap()->gc_count(), initial_gc_count + 1);
  }
  
  
  // Test that HAllocateObject will always return an object in new-space.
  TEST(OptimizedAllocationAlwaysInNewSpace) {
    i::FLAG_allow_natives_syntax = true;
    CcTest::InitializeVM();
    if (!CcTest::i_isolate()->use_crankshaft() || i::FLAG_always_opt) return;
    if (i::FLAG_gc_global || i::FLAG_stress_compaction) return;
    v8::HandleScope scope(CcTest::isolate());
    v8::Local<v8::Context> ctx = CcTest::isolate()->GetCurrentContext();
    heap::SimulateFullSpace(CcTest::heap()->new_space());
    AlwaysAllocateScope always_allocate(CcTest::i_isolate());
    v8::Local<v8::Value> res = CompileRun(
        "function c(x) {"
        "  this.x = x;"
        "  for (var i = 0; i < 32; i++) {"
        "    this['x' + i] = x;"
        "  }"
        "}"
        "function f(x) { return new c(x); };"
        "f(1); f(2); f(3);"
        "%OptimizeFunctionOnNextCall(f);"
        "f(4);");
  
    CHECK_EQ(4, res.As<v8::Object>()
                    ->GetRealNamedProperty(ctx, v8_str("x"))
                    .ToLocalChecked()
                    ->Int32Value(ctx)
                    .FromJust());
  
    i::Handle<JSReceiver> o =
        v8::Utils::OpenHandle(*v8::Local<v8::Object>::Cast(res));
  
    CHECK(CcTest::heap()->InNewSpace(*o));
  }
  
  
  TEST(OptimizedPretenuringAllocationFolding) {
    i::FLAG_allow_natives_syntax = true;
    i::FLAG_expose_gc = true;
    CcTest::InitializeVM();
    if (!CcTest::i_isolate()->use_crankshaft() || i::FLAG_always_opt) return;
    if (i::FLAG_gc_global || i::FLAG_stress_compaction) return;
    v8::HandleScope scope(CcTest::isolate());
    v8::Local<v8::Context> ctx = CcTest::isolate()->GetCurrentContext();
    // Grow new space unitl maximum capacity reached.
    while (!CcTest::heap()->new_space()->IsAtMaximumCapacity()) {
      CcTest::heap()->new_space()->Grow();
    }
  
    i::ScopedVector<char> source(1024);
    i::SNPrintF(
        source,
        "var number_elements = %d;"
        "var elements = new Array();"
        "function f() {"
        "  for (var i = 0; i < number_elements; i++) {"
        "    elements[i] = [[{}], [1.1]];"
        "  }"
        "  return elements[number_elements-1]"
        "};"
        "f(); gc();"
        "f(); f();"
        "%%OptimizeFunctionOnNextCall(f);"
        "f();",
        AllocationSite::kPretenureMinimumCreated);
  
    v8::Local<v8::Value> res = CompileRun(source.start());
  
    v8::Local<v8::Value> int_array =
        v8::Object::Cast(*res)->Get(ctx, v8_str("0")).ToLocalChecked();
    i::Handle<JSObject> int_array_handle = i::Handle<JSObject>::cast(
        v8::Utils::OpenHandle(*v8::Local<v8::Object>::Cast(int_array)));
    v8::Local<v8::Value> double_array =
        v8::Object::Cast(*res)->Get(ctx, v8_str("1")).ToLocalChecked();
    i::Handle<JSObject> double_array_handle = i::Handle<JSObject>::cast(
        v8::Utils::OpenHandle(*v8::Local<v8::Object>::Cast(double_array)));
  
    i::Handle<JSReceiver> o =
        v8::Utils::OpenHandle(*v8::Local<v8::Object>::Cast(res));
    CHECK(CcTest::heap()->InOldSpace(*o));
    CHECK(CcTest::heap()->InOldSpace(*int_array_handle));
    CHECK(CcTest::heap()->InOldSpace(int_array_handle->elements()));
    CHECK(CcTest::heap()->InOldSpace(*double_array_handle));
    CHECK(CcTest::heap()->InOldSpace(double_array_handle->elements()));
  }
  
  
  TEST(OptimizedPretenuringObjectArrayLiterals) {
    i::FLAG_allow_natives_syntax = true;
    i::FLAG_expose_gc = true;
    CcTest::InitializeVM();
    if (!CcTest::i_isolate()->use_crankshaft() || i::FLAG_always_opt) return;
    if (i::FLAG_gc_global || i::FLAG_stress_compaction) return;
    v8::HandleScope scope(CcTest::isolate());
  
    // Grow new space unitl maximum capacity reached.
    while (!CcTest::heap()->new_space()->IsAtMaximumCapacity()) {
      CcTest::heap()->new_space()->Grow();
    }
  
    i::ScopedVector<char> source(1024);
    i::SNPrintF(
        source,
        "var number_elements = %d;"
        "var elements = new Array(number_elements);"
        "function f() {"
        "  for (var i = 0; i < number_elements; i++) {"
        "    elements[i] = [{}, {}, {}];"
        "  }"
        "  return elements[number_elements - 1];"
        "};"
        "f(); gc();"
        "f(); f();"
        "%%OptimizeFunctionOnNextCall(f);"
        "f();",
        AllocationSite::kPretenureMinimumCreated);
  
    v8::Local<v8::Value> res = CompileRun(source.start());
  
    i::Handle<JSObject> o = Handle<JSObject>::cast(
        v8::Utils::OpenHandle(*v8::Local<v8::Object>::Cast(res)));
  
    CHECK(CcTest::heap()->InOldSpace(o->elements()));
    CHECK(CcTest::heap()->InOldSpace(*o));
  }
  
  
  TEST(OptimizedPretenuringMixedInObjectProperties) {
    i::FLAG_allow_natives_syntax = true;
    i::FLAG_expose_gc = true;
    CcTest::InitializeVM();
    if (!CcTest::i_isolate()->use_crankshaft() || i::FLAG_always_opt) return;
    if (i::FLAG_gc_global || i::FLAG_stress_compaction) return;
    v8::HandleScope scope(CcTest::isolate());
  
    // Grow new space unitl maximum capacity reached.
    while (!CcTest::heap()->new_space()->IsAtMaximumCapacity()) {
      CcTest::heap()->new_space()->Grow();
    }
  
  
    i::ScopedVector<char> source(1024);
    i::SNPrintF(
        source,
        "var number_elements = %d;"
        "var elements = new Array(number_elements);"
        "function f() {"
        "  for (var i = 0; i < number_elements; i++) {"
        "    elements[i] = {a: {c: 2.2, d: {}}, b: 1.1};"
        "  }"
        "  return elements[number_elements - 1];"
        "};"
        "f(); gc();"
        "f(); f();"
        "%%OptimizeFunctionOnNextCall(f);"
        "f();",
        AllocationSite::kPretenureMinimumCreated);
  
    v8::Local<v8::Value> res = CompileRun(source.start());
  
    i::Handle<JSObject> o = Handle<JSObject>::cast(
        v8::Utils::OpenHandle(*v8::Local<v8::Object>::Cast(res)));
  
    CHECK(CcTest::heap()->InOldSpace(*o));
    FieldIndex idx1 = FieldIndex::ForPropertyIndex(o->map(), 0);
    FieldIndex idx2 = FieldIndex::ForPropertyIndex(o->map(), 1);
    CHECK(CcTest::heap()->InOldSpace(o->RawFastPropertyAt(idx1)));
    if (!o->IsUnboxedDoubleField(idx2)) {
      CHECK(CcTest::heap()->InOldSpace(o->RawFastPropertyAt(idx2)));
    } else {
      CHECK_EQ(1.1, o->RawFastDoublePropertyAt(idx2));
    }
  
    JSObject* inner_object =
        reinterpret_cast<JSObject*>(o->RawFastPropertyAt(idx1));
    CHECK(CcTest::heap()->InOldSpace(inner_object));
    if (!inner_object->IsUnboxedDoubleField(idx1)) {
      CHECK(CcTest::heap()->InOldSpace(inner_object->RawFastPropertyAt(idx1)));
    } else {
      CHECK_EQ(2.2, inner_object->RawFastDoublePropertyAt(idx1));
    }
    CHECK(CcTest::heap()->InOldSpace(inner_object->RawFastPropertyAt(idx2)));
  }
  
  
  TEST(OptimizedPretenuringDoubleArrayProperties) {
    i::FLAG_allow_natives_syntax = true;
    i::FLAG_expose_gc = true;
    CcTest::InitializeVM();
    if (!CcTest::i_isolate()->use_crankshaft() || i::FLAG_always_opt) return;
    if (i::FLAG_gc_global || i::FLAG_stress_compaction) return;
    v8::HandleScope scope(CcTest::isolate());
  
    // Grow new space unitl maximum capacity reached.
    while (!CcTest::heap()->new_space()->IsAtMaximumCapacity()) {
      CcTest::heap()->new_space()->Grow();
    }
  
    i::ScopedVector<char> source(1024);
    i::SNPrintF(
        source,
        "var number_elements = %d;"
        "var elements = new Array(number_elements);"
        "function f() {"
        "  for (var i = 0; i < number_elements; i++) {"
        "    elements[i] = {a: 1.1, b: 2.2};"
        "  }"
        "  return elements[i - 1];"
        "};"
        "f(); gc();"
        "f(); f();"
        "%%OptimizeFunctionOnNextCall(f);"
        "f();",
        AllocationSite::kPretenureMinimumCreated);
  
    v8::Local<v8::Value> res = CompileRun(source.start());
  
    i::Handle<JSObject> o = Handle<JSObject>::cast(
        v8::Utils::OpenHandle(*v8::Local<v8::Object>::Cast(res)));
  
    CHECK(CcTest::heap()->InOldSpace(*o));
    CHECK(CcTest::heap()->InOldSpace(o->properties()));
  }
  
  
  TEST(OptimizedPretenuringdoubleArrayLiterals) {
    i::FLAG_allow_natives_syntax = true;
    i::FLAG_expose_gc = true;
    CcTest::InitializeVM();
    if (!CcTest::i_isolate()->use_crankshaft() || i::FLAG_always_opt) return;
    if (i::FLAG_gc_global || i::FLAG_stress_compaction) return;
    v8::HandleScope scope(CcTest::isolate());
  
    // Grow new space unitl maximum capacity reached.
    while (!CcTest::heap()->new_space()->IsAtMaximumCapacity()) {
      CcTest::heap()->new_space()->Grow();
    }
  
    i::ScopedVector<char> source(1024);
    i::SNPrintF(
        source,
        "var number_elements = %d;"
        "var elements = new Array(number_elements);"
        "function f() {"
        "  for (var i = 0; i < number_elements; i++) {"
        "    elements[i] = [1.1, 2.2, 3.3];"
        "  }"
        "  return elements[number_elements - 1];"
        "};"
        "f(); gc();"
        "f(); f();"
        "%%OptimizeFunctionOnNextCall(f);"
        "f();",
        AllocationSite::kPretenureMinimumCreated);
  
    v8::Local<v8::Value> res = CompileRun(source.start());
  
    i::Handle<JSObject> o = Handle<JSObject>::cast(
        v8::Utils::OpenHandle(*v8::Local<v8::Object>::Cast(res)));
  
    CHECK(CcTest::heap()->InOldSpace(o->elements()));
    CHECK(CcTest::heap()->InOldSpace(*o));
  }
  
  
  TEST(OptimizedPretenuringNestedMixedArrayLiterals) {
    i::FLAG_allow_natives_syntax = true;
    i::FLAG_expose_gc = true;
    CcTest::InitializeVM();
    if (!CcTest::i_isolate()->use_crankshaft() || i::FLAG_always_opt) return;
    if (i::FLAG_gc_global || i::FLAG_stress_compaction) return;
    v8::HandleScope scope(CcTest::isolate());
    v8::Local<v8::Context> ctx = CcTest::isolate()->GetCurrentContext();
    // Grow new space unitl maximum capacity reached.
    while (!CcTest::heap()->new_space()->IsAtMaximumCapacity()) {
      CcTest::heap()->new_space()->Grow();
    }
  
    i::ScopedVector<char> source(1024);
    i::SNPrintF(
        source,
        "var number_elements = 100;"
        "var elements = new Array(number_elements);"
        "function f() {"
        "  for (var i = 0; i < number_elements; i++) {"
        "    elements[i] = [[{}, {}, {}], [1.1, 2.2, 3.3]];"
        "  }"
        "  return elements[number_elements - 1];"
        "};"
        "f(); gc();"
        "f(); f();"
        "%%OptimizeFunctionOnNextCall(f);"
        "f();");
  
    v8::Local<v8::Value> res = CompileRun(source.start());
  
    v8::Local<v8::Value> int_array =
        v8::Object::Cast(*res)->Get(ctx, v8_str("0")).ToLocalChecked();
    i::Handle<JSObject> int_array_handle = i::Handle<JSObject>::cast(
        v8::Utils::OpenHandle(*v8::Local<v8::Object>::Cast(int_array)));
    v8::Local<v8::Value> double_array =
        v8::Object::Cast(*res)->Get(ctx, v8_str("1")).ToLocalChecked();
    i::Handle<JSObject> double_array_handle = i::Handle<JSObject>::cast(
        v8::Utils::OpenHandle(*v8::Local<v8::Object>::Cast(double_array)));
  
    Handle<JSObject> o = Handle<JSObject>::cast(
        v8::Utils::OpenHandle(*v8::Local<v8::Object>::Cast(res)));
    CHECK(CcTest::heap()->InOldSpace(*o));
    CHECK(CcTest::heap()->InOldSpace(*int_array_handle));
    CHECK(CcTest::heap()->InOldSpace(int_array_handle->elements()));
    CHECK(CcTest::heap()->InOldSpace(*double_array_handle));
    CHECK(CcTest::heap()->InOldSpace(double_array_handle->elements()));
  }
  
  
  TEST(OptimizedPretenuringNestedObjectLiterals) {
    i::FLAG_allow_natives_syntax = true;
    i::FLAG_expose_gc = true;
    CcTest::InitializeVM();
    if (!CcTest::i_isolate()->use_crankshaft() || i::FLAG_always_opt) return;
    if (i::FLAG_gc_global || i::FLAG_stress_compaction) return;
    v8::HandleScope scope(CcTest::isolate());
    v8::Local<v8::Context> ctx = CcTest::isolate()->GetCurrentContext();
    // Grow new space unitl maximum capacity reached.
    while (!CcTest::heap()->new_space()->IsAtMaximumCapacity()) {
      CcTest::heap()->new_space()->Grow();
    }
  
    i::ScopedVector<char> source(1024);
    i::SNPrintF(
        source,
        "var number_elements = %d;"
        "var elements = new Array(number_elements);"
        "function f() {"
        "  for (var i = 0; i < number_elements; i++) {"
        "    elements[i] = [[{}, {}, {}],[{}, {}, {}]];"
        "  }"
        "  return elements[number_elements - 1];"
        "};"
        "f(); gc();"
        "f(); f();"
        "%%OptimizeFunctionOnNextCall(f);"
        "f();",
        AllocationSite::kPretenureMinimumCreated);
  
    v8::Local<v8::Value> res = CompileRun(source.start());
  
    v8::Local<v8::Value> int_array_1 =
        v8::Object::Cast(*res)->Get(ctx, v8_str("0")).ToLocalChecked();
    Handle<JSObject> int_array_handle_1 = Handle<JSObject>::cast(
        v8::Utils::OpenHandle(*v8::Local<v8::Object>::Cast(int_array_1)));
    v8::Local<v8::Value> int_array_2 =
        v8::Object::Cast(*res)->Get(ctx, v8_str("1")).ToLocalChecked();
    Handle<JSObject> int_array_handle_2 = Handle<JSObject>::cast(
        v8::Utils::OpenHandle(*v8::Local<v8::Object>::Cast(int_array_2)));
  
    Handle<JSObject> o = Handle<JSObject>::cast(
        v8::Utils::OpenHandle(*v8::Local<v8::Object>::Cast(res)));
    CHECK(CcTest::heap()->InOldSpace(*o));
    CHECK(CcTest::heap()->InOldSpace(*int_array_handle_1));
    CHECK(CcTest::heap()->InOldSpace(int_array_handle_1->elements()));
    CHECK(CcTest::heap()->InOldSpace(*int_array_handle_2));
    CHECK(CcTest::heap()->InOldSpace(int_array_handle_2->elements()));
  }
  
  
  TEST(OptimizedPretenuringNestedDoubleLiterals) {
    i::FLAG_allow_natives_syntax = true;
    i::FLAG_expose_gc = true;
    CcTest::InitializeVM();
    if (!CcTest::i_isolate()->use_crankshaft() || i::FLAG_always_opt) return;
    if (i::FLAG_gc_global || i::FLAG_stress_compaction) return;
    v8::HandleScope scope(CcTest::isolate());
    v8::Local<v8::Context> ctx = CcTest::isolate()->GetCurrentContext();
    // Grow new space unitl maximum capacity reached.
    while (!CcTest::heap()->new_space()->IsAtMaximumCapacity()) {
      CcTest::heap()->new_space()->Grow();
    }
  
    i::ScopedVector<char> source(1024);
    i::SNPrintF(
        source,
        "var number_elements = %d;"
        "var elements = new Array(number_elements);"
        "function f() {"
        "  for (var i = 0; i < number_elements; i++) {"
        "    elements[i] = [[1.1, 1.2, 1.3],[2.1, 2.2, 2.3]];"
        "  }"
        "  return elements[number_elements - 1];"
        "};"
        "f(); gc();"
        "f(); f();"
        "%%OptimizeFunctionOnNextCall(f);"
        "f();",
        AllocationSite::kPretenureMinimumCreated);
  
    v8::Local<v8::Value> res = CompileRun(source.start());
  
    v8::Local<v8::Value> double_array_1 =
        v8::Object::Cast(*res)->Get(ctx, v8_str("0")).ToLocalChecked();
    i::Handle<JSObject> double_array_handle_1 = i::Handle<JSObject>::cast(
        v8::Utils::OpenHandle(*v8::Local<v8::Object>::Cast(double_array_1)));
    v8::Local<v8::Value> double_array_2 =
        v8::Object::Cast(*res)->Get(ctx, v8_str("1")).ToLocalChecked();
    i::Handle<JSObject> double_array_handle_2 = Handle<JSObject>::cast(
        v8::Utils::OpenHandle(*v8::Local<v8::Object>::Cast(double_array_2)));
  
    i::Handle<JSObject> o = Handle<JSObject>::cast(
        v8::Utils::OpenHandle(*v8::Local<v8::Object>::Cast(res)));
    CHECK(CcTest::heap()->InOldSpace(*o));
    CHECK(CcTest::heap()->InOldSpace(*double_array_handle_1));
    CHECK(CcTest::heap()->InOldSpace(double_array_handle_1->elements()));
    CHECK(CcTest::heap()->InOldSpace(*double_array_handle_2));
    CHECK(CcTest::heap()->InOldSpace(double_array_handle_2->elements()));
  }
  
  
  // Test regular array literals allocation.
  TEST(OptimizedAllocationArrayLiterals) {
    i::FLAG_allow_natives_syntax = true;
    CcTest::InitializeVM();
    if (!CcTest::i_isolate()->use_crankshaft() || i::FLAG_always_opt) return;
    if (i::FLAG_gc_global || i::FLAG_stress_compaction) return;
    v8::HandleScope scope(CcTest::isolate());
    v8::Local<v8::Context> ctx = CcTest::isolate()->GetCurrentContext();
    v8::Local<v8::Value> res = CompileRun(
        "function f() {"
        "  var numbers = new Array(1, 2, 3);"
        "  numbers[0] = 3.14;"
        "  return numbers;"
        "};"
        "f(); f(); f();"
        "%OptimizeFunctionOnNextCall(f);"
        "f();");
    CHECK_EQ(static_cast<int>(3.14), v8::Object::Cast(*res)
                                         ->Get(ctx, v8_str("0"))
                                         .ToLocalChecked()
                                         ->Int32Value(ctx)
                                         .FromJust());
  
    i::Handle<JSObject> o = Handle<JSObject>::cast(
        v8::Utils::OpenHandle(*v8::Local<v8::Object>::Cast(res)));
  
    CHECK(CcTest::heap()->InNewSpace(o->elements()));
  }
  
  
  static int CountMapTransitions(Map* map) {
    return TransitionArray::NumberOfTransitions(map->raw_transitions());
  }
  
  
  // Test that map transitions are cleared and maps are collected with
  // incremental marking as well.
  TEST(Regress1465) {
    i::FLAG_stress_compaction = false;
    i::FLAG_allow_natives_syntax = true;
    i::FLAG_trace_incremental_marking = true;
    i::FLAG_retain_maps_for_n_gc = 0;
    CcTest::InitializeVM();
    v8::HandleScope scope(CcTest::isolate());
    v8::Local<v8::Context> ctx = CcTest::isolate()->GetCurrentContext();
    static const int transitions_count = 256;
  
    CompileRun("function F() {}");
    {
      AlwaysAllocateScope always_allocate(CcTest::i_isolate());
      for (int i = 0; i < transitions_count; i++) {
        EmbeddedVector<char, 64> buffer;
        SNPrintF(buffer, "var o = new F; o.prop%d = %d;", i, i);
        CompileRun(buffer.start());
      }
      CompileRun("var root = new F;");
    }
  
    i::Handle<JSReceiver> root =
        v8::Utils::OpenHandle(*v8::Local<v8::Object>::Cast(
            CcTest::global()->Get(ctx, v8_str("root")).ToLocalChecked()));
  
    // Count number of live transitions before marking.
    int transitions_before = CountMapTransitions(root->map());
    CompileRun("%DebugPrint(root);");
    CHECK_EQ(transitions_count, transitions_before);
  
    heap::SimulateIncrementalMarking(CcTest::heap());
    CcTest::heap()->CollectAllGarbage();
  
    // Count number of live transitions after marking.  Note that one transition
    // is left, because 'o' still holds an instance of one transition target.
    int transitions_after = CountMapTransitions(root->map());
    CompileRun("%DebugPrint(root);");
    CHECK_EQ(1, transitions_after);
  }
  
  
  #ifdef DEBUG
  static void AddTransitions(int transitions_count) {
    AlwaysAllocateScope always_allocate(CcTest::i_isolate());
    for (int i = 0; i < transitions_count; i++) {
      EmbeddedVector<char, 64> buffer;
      SNPrintF(buffer, "var o = new F; o.prop%d = %d;", i, i);
      CompileRun(buffer.start());
    }
  }
  
  
  static i::Handle<JSObject> GetByName(const char* name) {
    return i::Handle<JSObject>::cast(
        v8::Utils::OpenHandle(*v8::Local<v8::Object>::Cast(
            CcTest::global()
                ->Get(CcTest::isolate()->GetCurrentContext(), v8_str(name))
                .ToLocalChecked())));
  }
  
  
  static void AddPropertyTo(
      int gc_count, Handle<JSObject> object, const char* property_name) {
    Isolate* isolate = CcTest::i_isolate();
    Factory* factory = isolate->factory();
    Handle<String> prop_name = factory->InternalizeUtf8String(property_name);
    Handle<Smi> twenty_three(Smi::FromInt(23), isolate);
    i::FLAG_gc_interval = gc_count;
    i::FLAG_gc_global = true;
    i::FLAG_retain_maps_for_n_gc = 0;
    CcTest::heap()->set_allocation_timeout(gc_count);
    JSReceiver::SetProperty(object, prop_name, twenty_three, SLOPPY).Check();
  }
  
  
  TEST(TransitionArrayShrinksDuringAllocToZero) {
    i::FLAG_stress_compaction = false;
    i::FLAG_allow_natives_syntax = true;
    CcTest::InitializeVM();
    v8::HandleScope scope(CcTest::isolate());
    static const int transitions_count = 10;
    CompileRun("function F() { }");
    AddTransitions(transitions_count);
    CompileRun("var root = new F;");
    Handle<JSObject> root = GetByName("root");
  
    // Count number of live transitions before marking.
    int transitions_before = CountMapTransitions(root->map());
    CHECK_EQ(transitions_count, transitions_before);
  
    // Get rid of o
    CompileRun("o = new F;"
               "root = new F");
    root = GetByName("root");
    AddPropertyTo(2, root, "funny");
    CcTest::heap()->CollectGarbage(NEW_SPACE);
  
    // Count number of live transitions after marking.  Note that one transition
    // is left, because 'o' still holds an instance of one transition target.
    int transitions_after = CountMapTransitions(
        Map::cast(root->map()->GetBackPointer()));
    CHECK_EQ(1, transitions_after);
  }
  
  
  TEST(TransitionArrayShrinksDuringAllocToOne) {
    i::FLAG_stress_compaction = false;
    i::FLAG_allow_natives_syntax = true;
    CcTest::InitializeVM();
    v8::HandleScope scope(CcTest::isolate());
    static const int transitions_count = 10;
    CompileRun("function F() {}");
    AddTransitions(transitions_count);
    CompileRun("var root = new F;");
    Handle<JSObject> root = GetByName("root");
  
    // Count number of live transitions before marking.
    int transitions_before = CountMapTransitions(root->map());
    CHECK_EQ(transitions_count, transitions_before);
  
    root = GetByName("root");
    AddPropertyTo(2, root, "funny");
    CcTest::heap()->CollectGarbage(NEW_SPACE);
  
    // Count number of live transitions after marking.  Note that one transition
    // is left, because 'o' still holds an instance of one transition target.
    int transitions_after = CountMapTransitions(
        Map::cast(root->map()->GetBackPointer()));
    CHECK_EQ(2, transitions_after);
  }
  
  
  TEST(TransitionArrayShrinksDuringAllocToOnePropertyFound) {
    i::FLAG_stress_compaction = false;
    i::FLAG_allow_natives_syntax = true;
    CcTest::InitializeVM();
    v8::HandleScope scope(CcTest::isolate());
    static const int transitions_count = 10;
    CompileRun("function F() {}");
    AddTransitions(transitions_count);
    CompileRun("var root = new F;");
    Handle<JSObject> root = GetByName("root");
  
    // Count number of live transitions before marking.
    int transitions_before = CountMapTransitions(root->map());
    CHECK_EQ(transitions_count, transitions_before);
  
    root = GetByName("root");
    AddPropertyTo(0, root, "prop9");
    CcTest::i_isolate()->heap()->CollectGarbage(OLD_SPACE);
  
    // Count number of live transitions after marking.  Note that one transition
    // is left, because 'o' still holds an instance of one transition target.
    int transitions_after = CountMapTransitions(
        Map::cast(root->map()->GetBackPointer()));
    CHECK_EQ(1, transitions_after);
  }
  
  
  TEST(TransitionArraySimpleToFull) {
    i::FLAG_stress_compaction = false;
    i::FLAG_allow_natives_syntax = true;
    CcTest::InitializeVM();
    v8::HandleScope scope(CcTest::isolate());
    static const int transitions_count = 1;
    CompileRun("function F() {}");
    AddTransitions(transitions_count);
    CompileRun("var root = new F;");
    Handle<JSObject> root = GetByName("root");
  
    // Count number of live transitions before marking.
    int transitions_before = CountMapTransitions(root->map());
    CHECK_EQ(transitions_count, transitions_before);
  
    CompileRun("o = new F;"
               "root = new F");
    root = GetByName("root");
    CHECK(TransitionArray::IsSimpleTransition(root->map()->raw_transitions()));
    AddPropertyTo(2, root, "happy");
  
    // Count number of live transitions after marking.  Note that one transition
    // is left, because 'o' still holds an instance of one transition target.
    int transitions_after = CountMapTransitions(
        Map::cast(root->map()->GetBackPointer()));
    CHECK_EQ(1, transitions_after);
  }
  #endif  // DEBUG
  
  
  TEST(Regress2143a) {
    i::FLAG_incremental_marking = true;
    CcTest::InitializeVM();
    v8::HandleScope scope(CcTest::isolate());
  
    // Prepare a map transition from the root object together with a yet
    // untransitioned root object.
    CompileRun("var root = new Object;"
               "root.foo = 0;"
               "root = new Object;");
  
    heap::SimulateIncrementalMarking(CcTest::heap());
  
    // Compile a StoreIC that performs the prepared map transition. This
    // will restart incremental marking and should make sure the root is
    // marked grey again.
    CompileRun("function f(o) {"
               "  o.foo = 0;"
               "}"
               "f(new Object);"
               "f(root);");
  
    // This bug only triggers with aggressive IC clearing.
    CcTest::heap()->AgeInlineCaches();
  
    // Explicitly request GC to perform final marking step and sweeping.
    CcTest::heap()->CollectAllGarbage();
  
    Handle<JSReceiver> root = v8::Utils::OpenHandle(*v8::Local<v8::Object>::Cast(
        CcTest::global()
            ->Get(CcTest::isolate()->GetCurrentContext(), v8_str("root"))
            .ToLocalChecked()));
  
    // The root object should be in a sane state.
    CHECK(root->IsJSObject());
    CHECK(root->map()->IsMap());
  }
  
  
  TEST(Regress2143b) {
    i::FLAG_incremental_marking = true;
    i::FLAG_allow_natives_syntax = true;
    CcTest::InitializeVM();
    v8::HandleScope scope(CcTest::isolate());
  
    // Prepare a map transition from the root object together with a yet
    // untransitioned root object.
    CompileRun("var root = new Object;"
               "root.foo = 0;"
               "root = new Object;");
  
    heap::SimulateIncrementalMarking(CcTest::heap());
  
    // Compile an optimized LStoreNamedField that performs the prepared
    // map transition. This will restart incremental marking and should
    // make sure the root is marked grey again.
    CompileRun("function f(o) {"
               "  o.foo = 0;"
               "}"
               "f(new Object);"
               "f(new Object);"
               "%OptimizeFunctionOnNextCall(f);"
               "f(root);"
               "%DeoptimizeFunction(f);");
  
    // This bug only triggers with aggressive IC clearing.
    CcTest::heap()->AgeInlineCaches();
  
    // Explicitly request GC to perform final marking step and sweeping.
    CcTest::heap()->CollectAllGarbage();
  
    Handle<JSReceiver> root = v8::Utils::OpenHandle(*v8::Local<v8::Object>::Cast(
        CcTest::global()
            ->Get(CcTest::isolate()->GetCurrentContext(), v8_str("root"))
            .ToLocalChecked()));
  
    // The root object should be in a sane state.
    CHECK(root->IsJSObject());
    CHECK(root->map()->IsMap());
  }
  
  
  TEST(ReleaseOverReservedPages) {
    if (FLAG_never_compact) return;
    i::FLAG_trace_gc = true;
    // The optimizer can allocate stuff, messing up the test.
    i::FLAG_crankshaft = false;
    i::FLAG_always_opt = false;
    // Parallel compaction increases fragmentation, depending on how existing
    // memory is distributed. Since this is non-deterministic because of
    // concurrent sweeping, we disable it for this test.
    i::FLAG_parallel_compaction = false;
    // Concurrent sweeping adds non determinism, depending on when memory is
    // available for further reuse.
    i::FLAG_concurrent_sweeping = false;
    // Fast evacuation of pages may result in a different page count in old space.
    i::FLAG_page_promotion = false;
    CcTest::InitializeVM();
    Isolate* isolate = CcTest::i_isolate();
    Factory* factory = isolate->factory();
    Heap* heap = isolate->heap();
    v8::HandleScope scope(CcTest::isolate());
    static const int number_of_test_pages = 20;
  
    // Prepare many pages with low live-bytes count.
    PagedSpace* old_space = heap->old_space();
    const int initial_page_count = old_space->CountTotalPages();
    const int overall_page_count = number_of_test_pages + initial_page_count;
    for (int i = 0; i < number_of_test_pages; i++) {
      AlwaysAllocateScope always_allocate(isolate);
      heap::SimulateFullSpace(old_space);
      factory->NewFixedArray(1, TENURED);
    }
    CHECK_EQ(overall_page_count, old_space->CountTotalPages());
  
    // Triggering one GC will cause a lot of garbage to be discovered but
    // even spread across all allocated pages.
    heap->CollectAllGarbage(Heap::kFinalizeIncrementalMarkingMask,
                            "triggered for preparation");
    CHECK_GE(overall_page_count, old_space->CountTotalPages());
  
    // Triggering subsequent GCs should cause at least half of the pages
    // to be released to the OS after at most two cycles.
    heap->CollectAllGarbage(Heap::kFinalizeIncrementalMarkingMask,
                            "triggered by test 1");
    CHECK_GE(overall_page_count, old_space->CountTotalPages());
    heap->CollectAllGarbage(Heap::kFinalizeIncrementalMarkingMask,
                            "triggered by test 2");
    CHECK_GE(overall_page_count, old_space->CountTotalPages() * 2);
  
    // Triggering a last-resort GC should cause all pages to be released to the
    // OS so that other processes can seize the memory.  If we get a failure here
    // where there are 2 pages left instead of 1, then we should increase the
    // size of the first page a little in SizeOfFirstPage in spaces.cc.  The
    // first page should be small in order to reduce memory used when the VM
    // boots, but if the 20 small arrays don't fit on the first page then that's
    // an indication that it is too small.
    heap->CollectAllAvailableGarbage("triggered really hard");
    CHECK_EQ(initial_page_count, old_space->CountTotalPages());
  }
  
  static int forced_gc_counter = 0;
  
  void MockUseCounterCallback(v8::Isolate* isolate,
                              v8::Isolate::UseCounterFeature feature) {
    isolate->GetCurrentContext();
    if (feature == v8::Isolate::kForcedGC) {
      forced_gc_counter++;
    }
  }
  
  
  TEST(CountForcedGC) {
    i::FLAG_expose_gc = true;
    CcTest::InitializeVM();
    Isolate* isolate = CcTest::i_isolate();
    v8::HandleScope scope(CcTest::isolate());
  
    isolate->SetUseCounterCallback(MockUseCounterCallback);
  
    forced_gc_counter = 0;
    const char* source = "gc();";
    CompileRun(source);
    CHECK_GT(forced_gc_counter, 0);
  }
  
  
  #ifdef OBJECT_PRINT
  TEST(PrintSharedFunctionInfo) {
    CcTest::InitializeVM();
    v8::HandleScope scope(CcTest::isolate());
    v8::Local<v8::Context> ctx = CcTest::isolate()->GetCurrentContext();
    const char* source = "f = function() { return 987654321; }\n"
                         "g = function() { return 123456789; }\n";
    CompileRun(source);
    i::Handle<JSFunction> g = i::Handle<JSFunction>::cast(
        v8::Utils::OpenHandle(*v8::Local<v8::Function>::Cast(
            CcTest::global()->Get(ctx, v8_str("g")).ToLocalChecked())));
  
    OFStream os(stdout);
    g->shared()->Print(os);
    os << std::endl;
  }
  #endif  // OBJECT_PRINT
  
  
  TEST(IncrementalMarkingPreservesMonomorphicCallIC) {
    if (i::FLAG_always_opt) return;
    CcTest::InitializeVM();
    v8::HandleScope scope(CcTest::isolate());
    v8::Local<v8::Value> fun1, fun2;
    v8::Local<v8::Context> ctx = CcTest::isolate()->GetCurrentContext();
    {
      CompileRun("function fun() {};");
      fun1 = CcTest::global()->Get(ctx, v8_str("fun")).ToLocalChecked();
    }
  
    {
      CompileRun("function fun() {};");
      fun2 = CcTest::global()->Get(ctx, v8_str("fun")).ToLocalChecked();
    }
  
    // Prepare function f that contains type feedback for the two closures.
    CHECK(CcTest::global()->Set(ctx, v8_str("fun1"), fun1).FromJust());
    CHECK(CcTest::global()->Set(ctx, v8_str("fun2"), fun2).FromJust());
    CompileRun("function f(a, b) { a(); b(); } f(fun1, fun2);");
  
    Handle<JSFunction> f = Handle<JSFunction>::cast(
        v8::Utils::OpenHandle(*v8::Local<v8::Function>::Cast(
            CcTest::global()->Get(ctx, v8_str("f")).ToLocalChecked())));
  
    Handle<TypeFeedbackVector> feedback_vector(f->feedback_vector());
    FeedbackVectorHelper feedback_helper(feedback_vector);
  
    int expected_slots = 2;
    CHECK_EQ(expected_slots, feedback_helper.slot_count());
    int slot1 = 0;
    int slot2 = 1;
    CHECK(feedback_vector->Get(feedback_helper.slot(slot1))->IsWeakCell());
    CHECK(feedback_vector->Get(feedback_helper.slot(slot2))->IsWeakCell());
  
    heap::SimulateIncrementalMarking(CcTest::heap());
    CcTest::heap()->CollectAllGarbage();
  
    CHECK(!WeakCell::cast(feedback_vector->Get(feedback_helper.slot(slot1)))
               ->cleared());
    CHECK(!WeakCell::cast(feedback_vector->Get(feedback_helper.slot(slot2)))
               ->cleared());
  }
  
  
  static Code* FindFirstIC(Code* code, Code::Kind kind) {
    int mask = RelocInfo::ModeMask(RelocInfo::CODE_TARGET) |
               RelocInfo::ModeMask(RelocInfo::CODE_TARGET_WITH_ID);
    for (RelocIterator it(code, mask); !it.done(); it.next()) {
      RelocInfo* info = it.rinfo();
      Code* target = Code::GetCodeFromTargetAddress(info->target_address());
      if (target->is_inline_cache_stub() && target->kind() == kind) {
        return target;
      }
    }
    return NULL;
  }
  
  
  static void CheckVectorIC(Handle<JSFunction> f, int slot_index,
                            InlineCacheState desired_state) {
    Handle<TypeFeedbackVector> vector =
        Handle<TypeFeedbackVector>(f->feedback_vector());
    FeedbackVectorHelper helper(vector);
    FeedbackVectorSlot slot = helper.slot(slot_index);
    if (vector->GetKind(slot) == FeedbackVectorSlotKind::LOAD_IC) {
      LoadICNexus nexus(vector, slot);
      CHECK(nexus.StateFromFeedback() == desired_state);
    } else {
      CHECK_EQ(FeedbackVectorSlotKind::KEYED_LOAD_IC, vector->GetKind(slot));
      KeyedLoadICNexus nexus(vector, slot);
      CHECK(nexus.StateFromFeedback() == desired_state);
    }
  }
  
  TEST(IncrementalMarkingPreservesMonomorphicConstructor) {
    if (i::FLAG_always_opt) return;
    CcTest::InitializeVM();
    v8::HandleScope scope(CcTest::isolate());
    v8::Local<v8::Context> ctx = CcTest::isolate()->GetCurrentContext();
    // Prepare function f that contains a monomorphic IC for object
    // originating from the same native context.
    CompileRun(
        "function fun() { this.x = 1; };"
        "function f(o) { return new o(); } f(fun); f(fun);");
    Handle<JSFunction> f = Handle<JSFunction>::cast(
        v8::Utils::OpenHandle(*v8::Local<v8::Function>::Cast(
            CcTest::global()->Get(ctx, v8_str("f")).ToLocalChecked())));
  
    Handle<TypeFeedbackVector> vector(f->feedback_vector());
    CHECK(vector->Get(FeedbackVectorSlot(0))->IsWeakCell());
  
    heap::SimulateIncrementalMarking(CcTest::heap());
    CcTest::heap()->CollectAllGarbage();
  
    CHECK(vector->Get(FeedbackVectorSlot(0))->IsWeakCell());
  }
  
  TEST(IncrementalMarkingPreservesMonomorphicIC) {
    if (i::FLAG_always_opt) return;
    CcTest::InitializeVM();
    v8::HandleScope scope(CcTest::isolate());
    v8::Local<v8::Context> ctx = CcTest::isolate()->GetCurrentContext();
    // Prepare function f that contains a monomorphic IC for object
    // originating from the same native context.
    CompileRun("function fun() { this.x = 1; }; var obj = new fun();"
               "function f(o) { return o.x; } f(obj); f(obj);");
    Handle<JSFunction> f = Handle<JSFunction>::cast(
        v8::Utils::OpenHandle(*v8::Local<v8::Function>::Cast(
            CcTest::global()->Get(ctx, v8_str("f")).ToLocalChecked())));
  
    CheckVectorIC(f, 0, MONOMORPHIC);
  
    heap::SimulateIncrementalMarking(CcTest::heap());
    CcTest::heap()->CollectAllGarbage();
  
    CheckVectorIC(f, 0, MONOMORPHIC);
  }
  
  TEST(IncrementalMarkingPreservesPolymorphicIC) {
    if (i::FLAG_always_opt) return;
    CcTest::InitializeVM();
    v8::HandleScope scope(CcTest::isolate());
    v8::Local<v8::Value> obj1, obj2;
    v8::Local<v8::Context> ctx = CcTest::isolate()->GetCurrentContext();
  
    {
      LocalContext env;
      CompileRun("function fun() { this.x = 1; }; var obj = new fun();");
      obj1 = env->Global()->Get(env.local(), v8_str("obj")).ToLocalChecked();
    }
  
    {
      LocalContext env;
      CompileRun("function fun() { this.x = 2; }; var obj = new fun();");
      obj2 = env->Global()->Get(env.local(), v8_str("obj")).ToLocalChecked();
    }
  
    // Prepare function f that contains a polymorphic IC for objects
    // originating from two different native contexts.
    CHECK(CcTest::global()->Set(ctx, v8_str("obj1"), obj1).FromJust());
    CHECK(CcTest::global()->Set(ctx, v8_str("obj2"), obj2).FromJust());
    CompileRun("function f(o) { return o.x; } f(obj1); f(obj1); f(obj2);");
    Handle<JSFunction> f = Handle<JSFunction>::cast(
        v8::Utils::OpenHandle(*v8::Local<v8::Function>::Cast(
            CcTest::global()->Get(ctx, v8_str("f")).ToLocalChecked())));
  
    CheckVectorIC(f, 0, POLYMORPHIC);
  
    // Fire context dispose notification.
    heap::SimulateIncrementalMarking(CcTest::heap());
    CcTest::heap()->CollectAllGarbage();
  
    CheckVectorIC(f, 0, POLYMORPHIC);
  }
  
  TEST(ContextDisposeDoesntClearPolymorphicIC) {
    if (i::FLAG_always_opt) return;
    CcTest::InitializeVM();
    v8::HandleScope scope(CcTest::isolate());
    v8::Local<v8::Value> obj1, obj2;
    v8::Local<v8::Context> ctx = CcTest::isolate()->GetCurrentContext();
  
    {
      LocalContext env;
      CompileRun("function fun() { this.x = 1; }; var obj = new fun();");
      obj1 = env->Global()->Get(env.local(), v8_str("obj")).ToLocalChecked();
    }
  
    {
      LocalContext env;
      CompileRun("function fun() { this.x = 2; }; var obj = new fun();");
      obj2 = env->Global()->Get(env.local(), v8_str("obj")).ToLocalChecked();
    }
  
    // Prepare function f that contains a polymorphic IC for objects
    // originating from two different native contexts.
    CHECK(CcTest::global()->Set(ctx, v8_str("obj1"), obj1).FromJust());
    CHECK(CcTest::global()->Set(ctx, v8_str("obj2"), obj2).FromJust());
    CompileRun("function f(o) { return o.x; } f(obj1); f(obj1); f(obj2);");
    Handle<JSFunction> f = Handle<JSFunction>::cast(
        v8::Utils::OpenHandle(*v8::Local<v8::Function>::Cast(
            CcTest::global()->Get(ctx, v8_str("f")).ToLocalChecked())));
  
    CheckVectorIC(f, 0, POLYMORPHIC);
  
    // Fire context dispose notification.
    CcTest::isolate()->ContextDisposedNotification();
    heap::SimulateIncrementalMarking(CcTest::heap());
    CcTest::heap()->CollectAllGarbage();
  
    CheckVectorIC(f, 0, POLYMORPHIC);
  }
  
  
  class SourceResource : public v8::String::ExternalOneByteStringResource {
   public:
    explicit SourceResource(const char* data)
      : data_(data), length_(strlen(data)) { }
  
    virtual void Dispose() {
      i::DeleteArray(data_);
      data_ = NULL;
    }
  
    const char* data() const { return data_; }
  
    size_t length() const { return length_; }
  
    bool IsDisposed() { return data_ == NULL; }
  
   private:
    const char* data_;
    size_t length_;
  };
  
  
  void ReleaseStackTraceDataTest(v8::Isolate* isolate, const char* source,
                                 const char* accessor) {
    // Test that the data retained by the Error.stack accessor is released
    // after the first time the accessor is fired.  We use external string
    // to check whether the data is being released since the external string
    // resource's callback is fired when the external string is GC'ed.
    i::Isolate* i_isolate = reinterpret_cast<i::Isolate*>(isolate);
    v8::HandleScope scope(isolate);
    SourceResource* resource = new SourceResource(i::StrDup(source));
    {
      v8::HandleScope scope(isolate);
      v8::Local<v8::Context> ctx = isolate->GetCurrentContext();
      v8::Local<v8::String> source_string =
          v8::String::NewExternalOneByte(isolate, resource).ToLocalChecked();
      i_isolate->heap()->CollectAllAvailableGarbage();
      v8::Script::Compile(ctx, source_string)
          .ToLocalChecked()
          ->Run(ctx)
          .ToLocalChecked();
      CHECK(!resource->IsDisposed());
    }
    // i_isolate->heap()->CollectAllAvailableGarbage();
    CHECK(!resource->IsDisposed());
  
    CompileRun(accessor);
    i_isolate->heap()->CollectAllAvailableGarbage();
  
    // External source has been released.
    CHECK(resource->IsDisposed());
    delete resource;
  }
  
  
  UNINITIALIZED_TEST(ReleaseStackTraceData) {
    if (i::FLAG_always_opt) {
      // TODO(ulan): Remove this once the memory leak via code_next_link is fixed.
      // See: https://codereview.chromium.org/181833004/
      return;
    }
    FLAG_use_ic = false;  // ICs retain objects.
    FLAG_concurrent_recompilation = false;
    v8::Isolate::CreateParams create_params;
    create_params.array_buffer_allocator = CcTest::array_buffer_allocator();
    v8::Isolate* isolate = v8::Isolate::New(create_params);
    {
      v8::Isolate::Scope isolate_scope(isolate);
      v8::HandleScope handle_scope(isolate);
      v8::Context::New(isolate)->Enter();
      static const char* source1 = "var error = null;            "
      /* Normal Error */           "try {                        "
                                   "  throw new Error();         "
                                   "} catch (e) {                "
                                   "  error = e;                 "
                                   "}                            ";
      static const char* source2 = "var error = null;            "
      /* Stack overflow */         "try {                        "
                                   "  (function f() { f(); })(); "
                                   "} catch (e) {                "
                                   "  error = e;                 "
                                   "}                            ";
      static const char* source3 = "var error = null;            "
      /* Normal Error */           "try {                        "
      /* as prototype */           "  throw new Error();         "
                                   "} catch (e) {                "
                                   "  error = {};                "
                                   "  error.__proto__ = e;       "
                                   "}                            ";
      static const char* source4 = "var error = null;            "
      /* Stack overflow */         "try {                        "
      /* as prototype   */         "  (function f() { f(); })(); "
                                   "} catch (e) {                "
                                   "  error = {};                "
                                   "  error.__proto__ = e;       "
                                   "}                            ";
      static const char* getter = "error.stack";
      static const char* setter = "error.stack = 0";
  
      ReleaseStackTraceDataTest(isolate, source1, setter);
      ReleaseStackTraceDataTest(isolate, source2, setter);
      // We do not test source3 and source4 with setter, since the setter is
      // supposed to (untypically) write to the receiver, not the holder.  This is
      // to emulate the behavior of a data property.
  
      ReleaseStackTraceDataTest(isolate, source1, getter);
      ReleaseStackTraceDataTest(isolate, source2, getter);
      ReleaseStackTraceDataTest(isolate, source3, getter);
      ReleaseStackTraceDataTest(isolate, source4, getter);
    }
    isolate->Dispose();
  }
  
  
  TEST(Regress159140) {
    i::FLAG_allow_natives_syntax = true;
    CcTest::InitializeVM();
    Isolate* isolate = CcTest::i_isolate();
    LocalContext env;
    Heap* heap = isolate->heap();
    HandleScope scope(isolate);
  
    // Perform one initial GC to enable code flushing.
    heap->CollectAllGarbage();
  
    // Prepare several closures that are all eligible for code flushing
    // because all reachable ones are not optimized. Make sure that the
    // optimized code object is directly reachable through a handle so
    // that it is marked black during incremental marking.
    Handle<Code> code;
    {
      HandleScope inner_scope(isolate);
      CompileRun("function h(x) {}"
                 "function mkClosure() {"
                 "  return function(x) { return x + 1; };"
                 "}"
                 "var f = mkClosure();"
                 "var g = mkClosure();"
                 "f(1); f(2);"
                 "g(1); g(2);"
                 "h(1); h(2);"
                 "%OptimizeFunctionOnNextCall(f); f(3);"
                 "%OptimizeFunctionOnNextCall(h); h(3);");
  
      Handle<JSFunction> f = Handle<JSFunction>::cast(
          v8::Utils::OpenHandle(*v8::Local<v8::Function>::Cast(
              CcTest::global()->Get(env.local(), v8_str("f")).ToLocalChecked())));
      CHECK(f->is_compiled());
      CompileRun("f = null;");
  
      Handle<JSFunction> g = Handle<JSFunction>::cast(
          v8::Utils::OpenHandle(*v8::Local<v8::Function>::Cast(
              CcTest::global()->Get(env.local(), v8_str("g")).ToLocalChecked())));
      CHECK(g->is_compiled());
      const int kAgingThreshold = 6;
      for (int i = 0; i < kAgingThreshold; i++) {
        g->code()->MakeOlder(static_cast<MarkingParity>(i % 2));
      }
  
      code = inner_scope.CloseAndEscape(Handle<Code>(f->code()));
    }
  
    // Simulate incremental marking so that the functions are enqueued as
    // code flushing candidates. Then optimize one function. Finally
    // finish the GC to complete code flushing.
    heap::SimulateIncrementalMarking(heap);
    CompileRun("%OptimizeFunctionOnNextCall(g); g(3);");
    heap->CollectAllGarbage();
  
    // Unoptimized code is missing and the deoptimizer will go ballistic.
    CompileRun("g('bozo');");
  }
  
  
  TEST(Regress165495) {
    i::FLAG_allow_natives_syntax = true;
    CcTest::InitializeVM();
    Isolate* isolate = CcTest::i_isolate();
    Heap* heap = isolate->heap();
    HandleScope scope(isolate);
  
    // Perform one initial GC to enable code flushing.
    heap->CollectAllGarbage();
  
    // Prepare an optimized closure that the optimized code map will get
    // populated. Then age the unoptimized code to trigger code flushing
    // but make sure the optimized code is unreachable.
    {
      HandleScope inner_scope(isolate);
      LocalContext env;
      CompileRun("function mkClosure() {"
                 "  return function(x) { return x + 1; };"
                 "}"
                 "var f = mkClosure();"
                 "f(1); f(2);"
                 "%OptimizeFunctionOnNextCall(f); f(3);");
  
      Handle<JSFunction> f = Handle<JSFunction>::cast(
          v8::Utils::OpenHandle(*v8::Local<v8::Function>::Cast(
              CcTest::global()->Get(env.local(), v8_str("f")).ToLocalChecked())));
      CHECK(f->is_compiled());
      const int kAgingThreshold = 6;
      for (int i = 0; i < kAgingThreshold; i++) {
        f->shared()->code()->MakeOlder(static_cast<MarkingParity>(i % 2));
      }
  
      CompileRun("f = null;");
    }
  
    // Simulate incremental marking so that unoptimized code is flushed
    // even though it still is cached in the optimized code map.
    heap::SimulateIncrementalMarking(heap);
    heap->CollectAllGarbage();
  
    // Make a new closure that will get code installed from the code map.
    // Unoptimized code is missing and the deoptimizer will go ballistic.
    CompileRun("var g = mkClosure(); g('bozo');");
  }
  
  
  TEST(Regress169209) {
    i::FLAG_stress_compaction = false;
    i::FLAG_allow_natives_syntax = true;
  
    CcTest::InitializeVM();
    Isolate* isolate = CcTest::i_isolate();
    Heap* heap = isolate->heap();
    HandleScope scope(isolate);
  
    // Perform one initial GC to enable code flushing.
    heap->CollectAllGarbage();
  
    // Prepare a shared function info eligible for code flushing for which
    // the unoptimized code will be replaced during optimization.
    Handle<SharedFunctionInfo> shared1;
    {
      HandleScope inner_scope(isolate);
      LocalContext env;
      CompileRun("function f() { return 'foobar'; }"
                 "function g(x) { if (x) f(); }"
                 "f();"
                 "g(false);"
                 "g(false);");
  
      Handle<JSFunction> f = Handle<JSFunction>::cast(
          v8::Utils::OpenHandle(*v8::Local<v8::Function>::Cast(
              CcTest::global()->Get(env.local(), v8_str("f")).ToLocalChecked())));
      CHECK(f->is_compiled());
      const int kAgingThreshold = 6;
      for (int i = 0; i < kAgingThreshold; i++) {
        f->shared()->code()->MakeOlder(static_cast<MarkingParity>(i % 2));
      }
  
      shared1 = inner_scope.CloseAndEscape(handle(f->shared(), isolate));
    }
  
    // Prepare a shared function info eligible for code flushing that will
    // represent the dangling tail of the candidate list.
    Handle<SharedFunctionInfo> shared2;
    {
      HandleScope inner_scope(isolate);
      LocalContext env;
      CompileRun("function flushMe() { return 0; }"
                 "flushMe(1);");
  
      Handle<JSFunction> f = Handle<JSFunction>::cast(v8::Utils::OpenHandle(
          *v8::Local<v8::Function>::Cast(CcTest::global()
                                             ->Get(env.local(), v8_str("flushMe"))
                                             .ToLocalChecked())));
      CHECK(f->is_compiled());
      const int kAgingThreshold = 6;
      for (int i = 0; i < kAgingThreshold; i++) {
        f->shared()->code()->MakeOlder(static_cast<MarkingParity>(i % 2));
      }
  
      shared2 = inner_scope.CloseAndEscape(handle(f->shared(), isolate));
    }
  
    // Simulate incremental marking and collect code flushing candidates.
    heap::SimulateIncrementalMarking(heap);
    CHECK(shared1->code()->gc_metadata() != NULL);
  
    // Optimize function and make sure the unoptimized code is replaced.
    CompileRun("%OptimizeFunctionOnNextCall(g);"
               "g(false);");
  
    // Finish garbage collection cycle.
    heap->CollectAllGarbage();
    CHECK(shared1->code()->gc_metadata() == NULL);
  }
  
  
  TEST(Regress169928) {
    i::FLAG_allow_natives_syntax = true;
    i::FLAG_crankshaft = false;
    CcTest::InitializeVM();
    Isolate* isolate = CcTest::i_isolate();
    LocalContext env;
    Factory* factory = isolate->factory();
    v8::HandleScope scope(CcTest::isolate());
  
    // Some flags turn Scavenge collections into Mark-sweep collections
    // and hence are incompatible with this test case.
    if (FLAG_gc_global || FLAG_stress_compaction) return;
  
    // Prepare the environment
    CompileRun("function fastliteralcase(literal, value) {"
               "    literal[0] = value;"
               "    return literal;"
               "}"
               "function get_standard_literal() {"
               "    var literal = [1, 2, 3];"
               "    return literal;"
               "}"
               "obj = fastliteralcase(get_standard_literal(), 1);"
               "obj = fastliteralcase(get_standard_literal(), 1.5);"
               "obj = fastliteralcase(get_standard_literal(), 2);");
  
    // prepare the heap
    v8::Local<v8::String> mote_code_string =
        v8_str("fastliteralcase(mote, 2.5);");
  
    v8::Local<v8::String> array_name = v8_str("mote");
    CHECK(CcTest::global()
              ->Set(env.local(), array_name, v8::Int32::New(CcTest::isolate(), 0))
              .FromJust());
  
    // First make sure we flip spaces
    CcTest::heap()->CollectGarbage(NEW_SPACE);
  
    // Allocate the object.
    Handle<FixedArray> array_data = factory->NewFixedArray(2, NOT_TENURED);
    array_data->set(0, Smi::FromInt(1));
    array_data->set(1, Smi::FromInt(2));
  
    heap::AllocateAllButNBytes(
        CcTest::heap()->new_space(),
        JSArray::kSize + AllocationMemento::kSize + kPointerSize);
  
    Handle<JSArray> array =
        factory->NewJSArrayWithElements(array_data, FAST_SMI_ELEMENTS);
  
    CHECK_EQ(Smi::FromInt(2), array->length());
    CHECK(array->HasFastSmiOrObjectElements());
  
    // We need filler the size of AllocationMemento object, plus an extra
    // fill pointer value.
    HeapObject* obj = NULL;
    AllocationResult allocation =
        CcTest::heap()->new_space()->AllocateRawUnaligned(
            AllocationMemento::kSize + kPointerSize);
    CHECK(allocation.To(&obj));
    Address addr_obj = obj->address();
    CcTest::heap()->CreateFillerObjectAt(addr_obj,
                                         AllocationMemento::kSize + kPointerSize,
                                         ClearRecordedSlots::kNo);
  
    // Give the array a name, making sure not to allocate strings.
    v8::Local<v8::Object> array_obj = v8::Utils::ToLocal(array);
    CHECK(CcTest::global()->Set(env.local(), array_name, array_obj).FromJust());
  
    // This should crash with a protection violation if we are running a build
    // with the bug.
    AlwaysAllocateScope aa_scope(isolate);
    v8::Script::Compile(env.local(), mote_code_string)
        .ToLocalChecked()
        ->Run(env.local())
        .ToLocalChecked();
  }
  
  
  #ifdef DEBUG
  TEST(Regress513507) {
    i::FLAG_flush_optimized_code_cache = false;
    i::FLAG_allow_natives_syntax = true;
    i::FLAG_gc_global = true;
    CcTest::InitializeVM();
    Isolate* isolate = CcTest::i_isolate();
    LocalContext env;
    Heap* heap = isolate->heap();
    HandleScope scope(isolate);
  
    // Prepare function whose optimized code map we can use.
    Handle<SharedFunctionInfo> shared;
    {
      HandleScope inner_scope(isolate);
      CompileRun("function f() { return 1 }"
                 "f(); %OptimizeFunctionOnNextCall(f); f();");
  
      Handle<JSFunction> f = Handle<JSFunction>::cast(
          v8::Utils::OpenHandle(*v8::Local<v8::Function>::Cast(
              CcTest::global()->Get(env.local(), v8_str("f")).ToLocalChecked())));
      shared = inner_scope.CloseAndEscape(handle(f->shared(), isolate));
      CompileRun("f = null");
    }
  
    // Prepare optimized code that we can use.
    Handle<Code> code;
    {
      HandleScope inner_scope(isolate);
      CompileRun("function g() { return 2 }"
                 "g(); %OptimizeFunctionOnNextCall(g); g();");
  
      Handle<JSFunction> g = Handle<JSFunction>::cast(
          v8::Utils::OpenHandle(*v8::Local<v8::Function>::Cast(
              CcTest::global()->Get(env.local(), v8_str("g")).ToLocalChecked())));
      code = inner_scope.CloseAndEscape(handle(g->code(), isolate));
      if (!code->is_optimized_code()) return;
    }
  
    Handle<TypeFeedbackVector> vector =
        TypeFeedbackVector::New(isolate, handle(shared->feedback_metadata()));
    Handle<LiteralsArray> lit =
        LiteralsArray::New(isolate, vector, shared->num_literals());
    Handle<Context> context(isolate->context());
  
    // Add the new code several times to the optimized code map and also set an
    // allocation timeout so that expanding the code map will trigger a GC.
    heap->set_allocation_timeout(5);
    FLAG_gc_interval = 1000;
    for (int i = 0; i < 10; ++i) {
      BailoutId id = BailoutId(i);
      SharedFunctionInfo::AddToOptimizedCodeMap(shared, context, code, lit, id);
    }
  }
  #endif  // DEBUG
  
  
  TEST(Regress514122) {
    i::FLAG_flush_optimized_code_cache = false;
    i::FLAG_allow_natives_syntax = true;
    CcTest::InitializeVM();
    Isolate* isolate = CcTest::i_isolate();
    LocalContext env;
    Heap* heap = isolate->heap();
    HandleScope scope(isolate);
  
    // Perfrom one initial GC to enable code flushing.
    CcTest::heap()->CollectAllGarbage();
  
    // Prepare function whose optimized code map we can use.
    Handle<SharedFunctionInfo> shared;
    {
      HandleScope inner_scope(isolate);
      CompileRun("function f() { return 1 }"
                 "f(); %OptimizeFunctionOnNextCall(f); f();");
  
      Handle<JSFunction> f = Handle<JSFunction>::cast(
          v8::Utils::OpenHandle(*v8::Local<v8::Function>::Cast(
              CcTest::global()->Get(env.local(), v8_str("f")).ToLocalChecked())));
      shared = inner_scope.CloseAndEscape(handle(f->shared(), isolate));
      CompileRun("f = null");
    }
  
    // Prepare optimized code that we can use.
    Handle<Code> code;
    {
      HandleScope inner_scope(isolate);
      CompileRun("function g() { return 2 }"
                 "g(); %OptimizeFunctionOnNextCall(g); g();");
  
      Handle<JSFunction> g = Handle<JSFunction>::cast(
          v8::Utils::OpenHandle(*v8::Local<v8::Function>::Cast(
              CcTest::global()->Get(env.local(), v8_str("g")).ToLocalChecked())));
      code = inner_scope.CloseAndEscape(handle(g->code(), isolate));
      if (!code->is_optimized_code()) return;
    }
  
    Handle<TypeFeedbackVector> vector =
        TypeFeedbackVector::New(isolate, handle(shared->feedback_metadata()));
    Handle<LiteralsArray> lit =
        LiteralsArray::New(isolate, vector, shared->num_literals(), TENURED);
    Handle<Context> context(isolate->context());
  
    // Add the code several times to the optimized code map.
    for (int i = 0; i < 3; ++i) {
      HandleScope inner_scope(isolate);
      BailoutId id = BailoutId(i);
      SharedFunctionInfo::AddToOptimizedCodeMap(shared, context, code, lit, id);
    }
    shared->optimized_code_map()->Print();
  
    // Add the code with a literals array to be evacuated.
    Page* evac_page;
    {
      HandleScope inner_scope(isolate);
      AlwaysAllocateScope always_allocate(isolate);
      // Make sure literal is placed on an old-space evacuation candidate.
      heap::SimulateFullSpace(heap->old_space());
  
      // Make sure there the number of literals is > 0.
      Handle<LiteralsArray> lit = LiteralsArray::New(isolate, vector, 23);
  
      evac_page = Page::FromAddress(lit->address());
      BailoutId id = BailoutId(100);
      SharedFunctionInfo::AddToOptimizedCodeMap(shared, context, code, lit, id);
    }
  
    // Heap is ready, force {lit_page} to become an evacuation candidate and
    // simulate incremental marking to enqueue optimized code map.
    FLAG_manual_evacuation_candidates_selection = true;
    evac_page->SetFlag(MemoryChunk::FORCE_EVACUATION_CANDIDATE_FOR_TESTING);
    heap::SimulateIncrementalMarking(heap);
  
    // No matter whether reachable or not, {boomer} is doomed.
    Handle<Object> boomer(shared->optimized_code_map(), isolate);
  
    // Add the code several times to the optimized code map. This will leave old
    // copies of the optimized code map unreachable but still marked.
    for (int i = 3; i < 6; ++i) {
      HandleScope inner_scope(isolate);
      BailoutId id = BailoutId(i);
      SharedFunctionInfo::AddToOptimizedCodeMap(shared, context, code, lit, id);
    }
  
    // Trigger a GC to flush out the bug.
    heap->CollectGarbage(i::OLD_SPACE, "fire in the hole");
    boomer->Print();
  }
  
  
  TEST(OptimizedCodeMapReuseEntries) {
    i::FLAG_flush_optimized_code_cache = false;
    i::FLAG_allow_natives_syntax = true;
    // BUG(v8:4598): Since TurboFan doesn't treat maps in code weakly, we can't
    // run this test.
    if (i::FLAG_turbo) return;
    CcTest::InitializeVM();
    v8::Isolate* v8_isolate = CcTest::isolate();
    Isolate* isolate = CcTest::i_isolate();
    Heap* heap = isolate->heap();
    HandleScope scope(isolate);
  
    // Create 3 contexts, allow the 2nd one to be disposed, and verify that
    // a 4th context will re-use the weak slots in the optimized code map
    // to hold data, rather than expanding the map.
    v8::Local<v8::Context> c1 = v8::Context::New(v8_isolate);
    const char* source = "function foo(x) { var l = [1]; return x+l[0]; }";
    v8::ScriptCompiler::Source script_source(
        v8::String::NewFromUtf8(v8_isolate, source, v8::NewStringType::kNormal)
            .ToLocalChecked());
    v8::Local<v8::UnboundScript> indep =
        v8::ScriptCompiler::CompileUnboundScript(v8_isolate, &script_source)
            .ToLocalChecked();
    const char* toplevel = "foo(3); %OptimizeFunctionOnNextCall(foo); foo(3);";
    // Perfrom one initial GC to enable code flushing.
    heap->CollectAllGarbage();
  
    c1->Enter();
    indep->BindToCurrentContext()->Run(c1).ToLocalChecked();
    CompileRun(toplevel);
  
    Handle<SharedFunctionInfo> shared;
    Handle<JSFunction> foo = Handle<JSFunction>::cast(
        v8::Utils::OpenHandle(*v8::Local<v8::Function>::Cast(
            CcTest::global()->Get(c1, v8_str("foo")).ToLocalChecked())));
    CHECK(foo->shared()->is_compiled());
    shared = handle(foo->shared());
    c1->Exit();
  
    {
      HandleScope scope(isolate);
      v8::Local<v8::Context> c2 = v8::Context::New(v8_isolate);
      c2->Enter();
      indep->BindToCurrentContext()->Run(c2).ToLocalChecked();
      CompileRun(toplevel);
      c2->Exit();
    }
  
    {
      HandleScope scope(isolate);
      v8::Local<v8::Context> c3 = v8::Context::New(v8_isolate);
      c3->Enter();
      indep->BindToCurrentContext()->Run(c3).ToLocalChecked();
      CompileRun(toplevel);
      c3->Exit();
  
      // Now, collect garbage. Context c2 should have no roots to it, and it's
      // entry in the optimized code map should be free for a new context.
      for (int i = 0; i < 4; i++) {
        heap->CollectAllGarbage();
      }
  
      Handle<FixedArray> optimized_code_map =
          handle(shared->optimized_code_map());
      // There should be 3 entries in the map.
      CHECK_EQ(
          3, ((optimized_code_map->length() - SharedFunctionInfo::kEntriesStart) /
              SharedFunctionInfo::kEntryLength));
      // But one of them (formerly for c2) should be cleared.
      int cleared_count = 0;
      for (int i = SharedFunctionInfo::kEntriesStart;
           i < optimized_code_map->length();
           i += SharedFunctionInfo::kEntryLength) {
        cleared_count +=
            WeakCell::cast(
                optimized_code_map->get(i + SharedFunctionInfo::kContextOffset))
                    ->cleared()
                ? 1
                : 0;
      }
      CHECK_EQ(1, cleared_count);
  
      // Verify that a new context uses the cleared entry rather than creating a
      // new
      // optimized code map array.
      v8::Local<v8::Context> c4 = v8::Context::New(v8_isolate);
      c4->Enter();
      indep->BindToCurrentContext()->Run(c4).ToLocalChecked();
      CompileRun(toplevel);
      c4->Exit();
      CHECK_EQ(*optimized_code_map, shared->optimized_code_map());
  
      // Now each entry is in use.
      cleared_count = 0;
      for (int i = SharedFunctionInfo::kEntriesStart;
           i < optimized_code_map->length();
           i += SharedFunctionInfo::kEntryLength) {
        cleared_count +=
            WeakCell::cast(
                optimized_code_map->get(i + SharedFunctionInfo::kContextOffset))
                    ->cleared()
                ? 1
                : 0;
      }
      CHECK_EQ(0, cleared_count);
    }
  }
  
  
  TEST(Regress513496) {
    i::FLAG_flush_optimized_code_cache = false;
    i::FLAG_allow_natives_syntax = true;
    CcTest::InitializeVM();
    Isolate* isolate = CcTest::i_isolate();
    Heap* heap = isolate->heap();
    HandleScope scope(isolate);
  
    // Perfrom one initial GC to enable code flushing.
    CcTest::heap()->CollectAllGarbage();
  
    // Prepare an optimized closure with containing an inlined function. Then age
    // the inlined unoptimized code to trigger code flushing but make sure the
    // outer optimized code is kept in the optimized code map.
    Handle<SharedFunctionInfo> shared;
    {
      LocalContext context;
      HandleScope inner_scope(isolate);
      CompileRun(
          "function g(x) { return x + 1 }"
          "function mkClosure() {"
          "  return function(x) { return g(x); };"
          "}"
          "var f = mkClosure();"
          "f(1); f(2);"
          "%OptimizeFunctionOnNextCall(f); f(3);");
  
      Handle<JSFunction> g = Handle<JSFunction>::cast(v8::Utils::OpenHandle(
          *v8::Local<v8::Function>::Cast(CcTest::global()
                                             ->Get(context.local(), v8_str("g"))
                                             .ToLocalChecked())));
      CHECK(g->shared()->is_compiled());
      const int kAgingThreshold = 6;
      for (int i = 0; i < kAgingThreshold; i++) {
        g->shared()->code()->MakeOlder(static_cast<MarkingParity>(i % 2));
      }
  
      Handle<JSFunction> f = Handle<JSFunction>::cast(v8::Utils::OpenHandle(
          *v8::Local<v8::Function>::Cast(CcTest::global()
                                             ->Get(context.local(), v8_str("f"))
                                             .ToLocalChecked())));
      CHECK(f->is_compiled());
      shared = inner_scope.CloseAndEscape(handle(f->shared(), isolate));
      CompileRun("f = null");
    }
  
    // Lookup the optimized code and keep it alive.
    CodeAndLiterals result = shared->SearchOptimizedCodeMap(
        isolate->context()->native_context(), BailoutId::None());
    Handle<Code> optimized_code(result.code, isolate);
  
    // Finish a full GC cycle so that the unoptimized code of 'g' is flushed even
    // though the optimized code for 'f' is reachable via the optimized code map.
    heap->CollectAllGarbage();
  
    // Make a new closure that will get code installed from the code map.
    // Unoptimized code is missing and the deoptimizer will go ballistic.
    CompileRun("var h = mkClosure(); h('bozo');");
  }
  
  
  TEST(LargeObjectSlotRecording) {
    FLAG_manual_evacuation_candidates_selection = true;
    CcTest::InitializeVM();
    Isolate* isolate = CcTest::i_isolate();
    Heap* heap = isolate->heap();
    HandleScope scope(isolate);
  
    // Create an object on an evacuation candidate.
    heap::SimulateFullSpace(heap->old_space());
    Handle<FixedArray> lit = isolate->factory()->NewFixedArray(4, TENURED);
    Page* evac_page = Page::FromAddress(lit->address());
    evac_page->SetFlag(MemoryChunk::FORCE_EVACUATION_CANDIDATE_FOR_TESTING);
    FixedArray* old_location = *lit;
  
    // Allocate a large object.
    int size = Max(1000000, Page::kMaxRegularHeapObjectSize + KB);
    CHECK(size > Page::kMaxRegularHeapObjectSize);
    Handle<FixedArray> lo = isolate->factory()->NewFixedArray(size, TENURED);
    CHECK(heap->lo_space()->Contains(*lo));
  
    // Start incremental marking to active write barrier.
    heap::SimulateIncrementalMarking(heap, false);
    heap->incremental_marking()->AdvanceIncrementalMarking(
        10000000, IncrementalMarking::IdleStepActions());
  
    // Create references from the large object to the object on the evacuation
    // candidate.
    const int kStep = size / 10;
    for (int i = 0; i < size; i += kStep) {
      lo->set(i, *lit);
      CHECK(lo->get(i) == old_location);
    }
  
    // Move the evaucation candidate object.
    CcTest::heap()->CollectAllGarbage();
  
    // Verify that the pointers in the large object got updated.
    for (int i = 0; i < size; i += kStep) {
      CHECK_EQ(lo->get(i), *lit);
      CHECK(lo->get(i) != old_location);
    }
  }
  
  
  class DummyVisitor : public ObjectVisitor {
   public:
    void VisitPointers(Object** start, Object** end) override {}
  };
  
  
  TEST(DeferredHandles) {
    CcTest::InitializeVM();
    Isolate* isolate = CcTest::i_isolate();
    Heap* heap = isolate->heap();
    v8::HandleScope scope(reinterpret_cast<v8::Isolate*>(isolate));
    HandleScopeData* data = isolate->handle_scope_data();
    Handle<Object> init(heap->empty_string(), isolate);
    while (data->next < data->limit) {
      Handle<Object> obj(heap->empty_string(), isolate);
    }
    // An entire block of handles has been filled.
    // Next handle would require a new block.
    CHECK(data->next == data->limit);
  
    DeferredHandleScope deferred(isolate);
    DummyVisitor visitor;
    isolate->handle_scope_implementer()->Iterate(&visitor);
    delete deferred.Detach();
  }
  
  
  TEST(IncrementalMarkingStepMakesBigProgressWithLargeObjects) {
    CcTest::InitializeVM();
    v8::HandleScope scope(CcTest::isolate());
    CompileRun("function f(n) {"
               "    var a = new Array(n);"
               "    for (var i = 0; i < n; i += 100) a[i] = i;"
               "};"
               "f(10 * 1024 * 1024);");
    IncrementalMarking* marking = CcTest::heap()->incremental_marking();
    if (marking->IsStopped()) {
      CcTest::heap()->StartIncrementalMarking();
    }
    // This big step should be sufficient to mark the whole array.
    marking->Step(100 * MB, IncrementalMarking::NO_GC_VIA_STACK_GUARD);
    CHECK(marking->IsComplete() ||
          marking->IsReadyToOverApproximateWeakClosure());
  }
  
  
  TEST(DisableInlineAllocation) {
    i::FLAG_allow_natives_syntax = true;
    CcTest::InitializeVM();
    v8::HandleScope scope(CcTest::isolate());
    CompileRun("function test() {"
               "  var x = [];"
               "  for (var i = 0; i < 10; i++) {"
               "    x[i] = [ {}, [1,2,3], [1,x,3] ];"
               "  }"
               "}"
               "function run() {"
               "  %OptimizeFunctionOnNextCall(test);"
               "  test();"
               "  %DeoptimizeFunction(test);"
               "}");
  
    // Warm-up with inline allocation enabled.
    CompileRun("test(); test(); run();");
  
    // Run test with inline allocation disabled.
    CcTest::heap()->DisableInlineAllocation();
    CompileRun("run()");
  
    // Run test with inline allocation re-enabled.
    CcTest::heap()->EnableInlineAllocation();
    CompileRun("run()");
  }
  
  
  static int AllocationSitesCount(Heap* heap) {
    int count = 0;
    for (Object* site = heap->allocation_sites_list();
         !(site->IsUndefined(heap->isolate()));
         site = AllocationSite::cast(site)->weak_next()) {
      count++;
    }
    return count;
  }
  
  
  TEST(EnsureAllocationSiteDependentCodesProcessed) {
    if (i::FLAG_always_opt || !i::FLAG_crankshaft) return;
    i::FLAG_allow_natives_syntax = true;
    CcTest::InitializeVM();
    Isolate* isolate = CcTest::i_isolate();
    v8::internal::Heap* heap = CcTest::heap();
    GlobalHandles* global_handles = isolate->global_handles();
  
    if (!isolate->use_crankshaft()) return;
  
    // The allocation site at the head of the list is ours.
    Handle<AllocationSite> site;
    {
      LocalContext context;
      v8::HandleScope scope(context->GetIsolate());
  
      int count = AllocationSitesCount(heap);
      CompileRun("var bar = function() { return (new Array()); };"
                 "var a = bar();"
                 "bar();"
                 "bar();");
  
      // One allocation site should have been created.
      int new_count = AllocationSitesCount(heap);
      CHECK_EQ(new_count, (count + 1));
      site = Handle<AllocationSite>::cast(
          global_handles->Create(
              AllocationSite::cast(heap->allocation_sites_list())));
  
      CompileRun("%OptimizeFunctionOnNextCall(bar); bar();");
  
      Handle<JSFunction> bar_handle = Handle<JSFunction>::cast(
          v8::Utils::OpenHandle(*v8::Local<v8::Function>::Cast(
              CcTest::global()
                  ->Get(context.local(), v8_str("bar"))
                  .ToLocalChecked())));
  
      int dependency_group_count = 0;
      DependentCode* dependency = site->dependent_code();
      while (dependency != heap->empty_fixed_array()) {
        CHECK(dependency->group() ==
                  DependentCode::kAllocationSiteTransitionChangedGroup ||
              dependency->group() ==
                  DependentCode::kAllocationSiteTenuringChangedGroup);
        CHECK_EQ(1, dependency->count());
        CHECK(dependency->object_at(0)->IsWeakCell());
        Code* function_bar =
            Code::cast(WeakCell::cast(dependency->object_at(0))->value());
        CHECK_EQ(bar_handle->code(), function_bar);
        dependency = dependency->next_link();
        dependency_group_count++;
      }
  
      // TurboFan respects pretenuring feedback from allocation sites, Crankshaft
      // does not. Either is fine for the purposes of this test.
      CHECK(dependency_group_count == 1 || dependency_group_count == 2);
    }
  
    // Now make sure that a gc should get rid of the function, even though we
    // still have the allocation site alive.
    for (int i = 0; i < 4; i++) {
      heap->CollectAllGarbage();
    }
  
    // The site still exists because of our global handle, but the code is no
    // longer referred to by dependent_code().
    CHECK(site->dependent_code()->object_at(0)->IsWeakCell() &&
          WeakCell::cast(site->dependent_code()->object_at(0))->cleared());
  }
  
  
  TEST(CellsInOptimizedCodeAreWeak) {
    if (i::FLAG_always_opt || !i::FLAG_crankshaft) return;
    i::FLAG_weak_embedded_objects_in_optimized_code = true;
    i::FLAG_allow_natives_syntax = true;
    CcTest::InitializeVM();
    Isolate* isolate = CcTest::i_isolate();
    v8::internal::Heap* heap = CcTest::heap();
  
    if (!isolate->use_crankshaft()) return;
    HandleScope outer_scope(heap->isolate());
    Handle<Code> code;
    {
      LocalContext context;
      HandleScope scope(heap->isolate());
  
      CompileRun(
          "bar = (function() {"
          "  function bar() {"
          "    return foo(1);"
          "  };"
          "  var foo = function(x) { with (x) { return 1 + x; } };"
          "  %NeverOptimizeFunction(foo);"
          "  bar(foo);"
          "  bar(foo);"
          "  bar(foo);"
          "  %OptimizeFunctionOnNextCall(bar);"
          "  bar(foo);"
          "  return bar;})();");
  
      Handle<JSFunction> bar = Handle<JSFunction>::cast(v8::Utils::OpenHandle(
          *v8::Local<v8::Function>::Cast(CcTest::global()
                                             ->Get(context.local(), v8_str("bar"))
                                             .ToLocalChecked())));
      code = scope.CloseAndEscape(Handle<Code>(bar->code()));
    }
  
    // Now make sure that a gc should get rid of the function
    for (int i = 0; i < 4; i++) {
      heap->CollectAllGarbage();
    }
  
    CHECK(code->marked_for_deoptimization());
  }
  
  
  TEST(ObjectsInOptimizedCodeAreWeak) {
    if (i::FLAG_always_opt || !i::FLAG_crankshaft) return;
    i::FLAG_weak_embedded_objects_in_optimized_code = true;
    i::FLAG_allow_natives_syntax = true;
    CcTest::InitializeVM();
    Isolate* isolate = CcTest::i_isolate();
    v8::internal::Heap* heap = CcTest::heap();
  
    if (!isolate->use_crankshaft()) return;
    HandleScope outer_scope(heap->isolate());
    Handle<Code> code;
    {
      LocalContext context;
      HandleScope scope(heap->isolate());
  
      CompileRun(
          "function bar() {"
          "  return foo(1);"
          "};"
          "function foo(x) { with (x) { return 1 + x; } };"
          "%NeverOptimizeFunction(foo);"
          "bar();"
          "bar();"
          "bar();"
          "%OptimizeFunctionOnNextCall(bar);"
          "bar();");
  
      Handle<JSFunction> bar = Handle<JSFunction>::cast(v8::Utils::OpenHandle(
          *v8::Local<v8::Function>::Cast(CcTest::global()
                                             ->Get(context.local(), v8_str("bar"))
                                             .ToLocalChecked())));
      code = scope.CloseAndEscape(Handle<Code>(bar->code()));
    }
  
    // Now make sure that a gc should get rid of the function
    for (int i = 0; i < 4; i++) {
      heap->CollectAllGarbage();
    }
  
    CHECK(code->marked_for_deoptimization());
  }
  
  TEST(NewSpaceObjectsInOptimizedCode) {
    if (i::FLAG_always_opt || !i::FLAG_crankshaft || i::FLAG_turbo) return;
    i::FLAG_weak_embedded_objects_in_optimized_code = true;
    i::FLAG_allow_natives_syntax = true;
    CcTest::InitializeVM();
    Isolate* isolate = CcTest::i_isolate();
    v8::internal::Heap* heap = CcTest::heap();
  
    if (!isolate->use_crankshaft()) return;
    HandleScope outer_scope(heap->isolate());
    Handle<Code> code;
    {
      LocalContext context;
      HandleScope scope(heap->isolate());
  
      CompileRun(
          "var foo;"
          "var bar;"
          "(function() {"
          "  function foo_func(x) { with (x) { return 1 + x; } };"
          "  %NeverOptimizeFunction(foo_func);"
          "  function bar_func() {"
          "    return foo(1);"
          "  };"
          "  bar = bar_func;"
          "  foo = foo_func;"
          "  bar_func();"
          "  bar_func();"
          "  bar_func();"
          "  %OptimizeFunctionOnNextCall(bar_func);"
          "  bar_func();"
          "})();");
  
      Handle<JSFunction> bar = Handle<JSFunction>::cast(v8::Utils::OpenHandle(
          *v8::Local<v8::Function>::Cast(CcTest::global()
                                             ->Get(context.local(), v8_str("bar"))
                                             .ToLocalChecked())));
  
      Handle<JSFunction> foo = Handle<JSFunction>::cast(v8::Utils::OpenHandle(
          *v8::Local<v8::Function>::Cast(CcTest::global()
                                             ->Get(context.local(), v8_str("foo"))
                                             .ToLocalChecked())));
  
      CHECK(heap->InNewSpace(*foo));
      heap->CollectGarbage(NEW_SPACE);
      heap->CollectGarbage(NEW_SPACE);
      CHECK(!heap->InNewSpace(*foo));
  #ifdef VERIFY_HEAP
      heap->Verify();
  #endif
      CHECK(!bar->code()->marked_for_deoptimization());
      code = scope.CloseAndEscape(Handle<Code>(bar->code()));
    }
  
    // Now make sure that a gc should get rid of the function
    for (int i = 0; i < 4; i++) {
      heap->CollectAllGarbage();
    }
  
    CHECK(code->marked_for_deoptimization());
  }
  
  TEST(NoWeakHashTableLeakWithIncrementalMarking) {
    if (i::FLAG_always_opt || !i::FLAG_crankshaft) return;
    if (!i::FLAG_incremental_marking) return;
    i::FLAG_weak_embedded_objects_in_optimized_code = true;
    i::FLAG_allow_natives_syntax = true;
    i::FLAG_compilation_cache = false;
    i::FLAG_retain_maps_for_n_gc = 0;
    CcTest::InitializeVM();
    Isolate* isolate = CcTest::i_isolate();
  
    // Do not run for no-snap builds.
    if (!i::Snapshot::HasContextSnapshot(isolate, 0)) return;
  
    v8::internal::Heap* heap = CcTest::heap();
  
    // Get a clean slate regarding optimized functions on the heap.
    i::Deoptimizer::DeoptimizeAll(isolate);
    heap->CollectAllGarbage();
  
    if (!isolate->use_crankshaft()) return;
    HandleScope outer_scope(heap->isolate());
    for (int i = 0; i < 3; i++) {
      heap::SimulateIncrementalMarking(heap);
      {
        LocalContext context;
        HandleScope scope(heap->isolate());
        EmbeddedVector<char, 256> source;
        SNPrintF(source,
                 "function bar%d() {"
                 "  return foo%d(1);"
                 "};"
                 "function foo%d(x) { with (x) { return 1 + x; } };"
                 "bar%d();"
                 "bar%d();"
                 "bar%d();"
                 "%%OptimizeFunctionOnNextCall(bar%d);"
                 "bar%d();",
                 i, i, i, i, i, i, i, i);
        CompileRun(source.start());
      }
      // We have to abort incremental marking here to abandon black pages.
      heap->CollectAllGarbage(Heap::kAbortIncrementalMarkingMask);
    }
    int elements = 0;
    if (heap->weak_object_to_code_table()->IsHashTable()) {
      WeakHashTable* t = WeakHashTable::cast(heap->weak_object_to_code_table());
      elements = t->NumberOfElements();
    }
    CHECK_EQ(0, elements);
  }
  
  
  static Handle<JSFunction> OptimizeDummyFunction(v8::Isolate* isolate,
                                                  const char* name) {
    EmbeddedVector<char, 256> source;
    SNPrintF(source,
            "function %s() { return 0; }"
            "%s(); %s();"
            "%%OptimizeFunctionOnNextCall(%s);"
            "%s();", name, name, name, name, name);
    CompileRun(source.start());
    i::Handle<JSFunction> fun = Handle<JSFunction>::cast(
        v8::Utils::OpenHandle(*v8::Local<v8::Function>::Cast(
            CcTest::global()
                ->Get(isolate->GetCurrentContext(), v8_str(name))
                .ToLocalChecked())));
    return fun;
  }
  
  
  static int GetCodeChainLength(Code* code) {
    int result = 0;
    while (code->next_code_link()->IsCode()) {
      result++;
      code = Code::cast(code->next_code_link());
    }
    return result;
  }
  
  
  TEST(NextCodeLinkIsWeak) {
    i::FLAG_always_opt = false;
    i::FLAG_allow_natives_syntax = true;
    CcTest::InitializeVM();
    Isolate* isolate = CcTest::i_isolate();
    v8::internal::Heap* heap = CcTest::heap();
  
    if (!isolate->use_crankshaft()) return;
    HandleScope outer_scope(heap->isolate());
    Handle<Code> code;
    heap->CollectAllAvailableGarbage();
    int code_chain_length_before, code_chain_length_after;
    {
      HandleScope scope(heap->isolate());
      Handle<JSFunction> mortal =
          OptimizeDummyFunction(CcTest::isolate(), "mortal");
      Handle<JSFunction> immortal =
          OptimizeDummyFunction(CcTest::isolate(), "immortal");
      CHECK_EQ(immortal->code()->next_code_link(), mortal->code());
      code_chain_length_before = GetCodeChainLength(immortal->code());
      // Keep the immortal code and let the mortal code die.
      code = scope.CloseAndEscape(Handle<Code>(immortal->code()));
      CompileRun("mortal = null; immortal = null;");
    }
    heap->CollectAllAvailableGarbage();
    // Now mortal code should be dead.
    code_chain_length_after = GetCodeChainLength(*code);
    CHECK_EQ(code_chain_length_before - 1, code_chain_length_after);
  }
  
  
  static Handle<Code> DummyOptimizedCode(Isolate* isolate) {
    i::byte buffer[i::Assembler::kMinimalBufferSize];
    MacroAssembler masm(isolate, buffer, sizeof(buffer),
                        v8::internal::CodeObjectRequired::kYes);
    CodeDesc desc;
    masm.Push(isolate->factory()->undefined_value());
    masm.Drop(1);
    masm.GetCode(&desc);
    Handle<Object> undefined(isolate->heap()->undefined_value(), isolate);
    Handle<Code> code = isolate->factory()->NewCode(
        desc, Code::ComputeFlags(Code::OPTIMIZED_FUNCTION), undefined);
    CHECK(code->IsCode());
    return code;
  }
  
  
  TEST(NextCodeLinkIsWeak2) {
    i::FLAG_allow_natives_syntax = true;
    CcTest::InitializeVM();
    Isolate* isolate = CcTest::i_isolate();
    v8::internal::Heap* heap = CcTest::heap();
  
    if (!isolate->use_crankshaft()) return;
    HandleScope outer_scope(heap->isolate());
    heap->CollectAllAvailableGarbage();
    Handle<Context> context(Context::cast(heap->native_contexts_list()), isolate);
    Handle<Code> new_head;
    Handle<Object> old_head(context->get(Context::OPTIMIZED_CODE_LIST), isolate);
    {
      HandleScope scope(heap->isolate());
      Handle<Code> immortal = DummyOptimizedCode(isolate);
      Handle<Code> mortal = DummyOptimizedCode(isolate);
      mortal->set_next_code_link(*old_head);
      immortal->set_next_code_link(*mortal);
      context->set(Context::OPTIMIZED_CODE_LIST, *immortal);
      new_head = scope.CloseAndEscape(immortal);
    }
    heap->CollectAllAvailableGarbage();
    // Now mortal code should be dead.
    CHECK_EQ(*old_head, new_head->next_code_link());
  }
  
  
  static bool weak_ic_cleared = false;
  
  static void ClearWeakIC(
      const v8::WeakCallbackInfo<v8::Persistent<v8::Object>>& data) {
    printf("clear weak is called\n");
    weak_ic_cleared = true;
    data.GetParameter()->Reset();
  }
  
  
  TEST(WeakFunctionInConstructor) {
    if (i::FLAG_always_opt) return;
    i::FLAG_stress_compaction = false;
    CcTest::InitializeVM();
    v8::Isolate* isolate = CcTest::isolate();
    LocalContext env;
    v8::HandleScope scope(isolate);
    CompileRun(
        "function createObj(obj) {"
        "  return new obj();"
        "}");
    i::Handle<JSFunction> createObj = Handle<JSFunction>::cast(
        v8::Utils::OpenHandle(*v8::Local<v8::Function>::Cast(
            CcTest::global()
                ->Get(env.local(), v8_str("createObj"))
                .ToLocalChecked())));
  
    v8::Persistent<v8::Object> garbage;
    {
      v8::HandleScope scope(isolate);
      const char* source =
          " (function() {"
          "   function hat() { this.x = 5; }"
          "   createObj(hat);"
          "   createObj(hat);"
          "   return hat;"
          " })();";
      garbage.Reset(isolate, CompileRun(env.local(), source)
                                 .ToLocalChecked()
                                 ->ToObject(env.local())
                                 .ToLocalChecked());
    }
    weak_ic_cleared = false;
    garbage.SetWeak(&garbage, &ClearWeakIC, v8::WeakCallbackType::kParameter);
    Heap* heap = CcTest::i_isolate()->heap();
    heap->CollectAllGarbage();
    CHECK(weak_ic_cleared);
  
    // We've determined the constructor in createObj has had it's weak cell
    // cleared. Now, verify that one additional call with a new function
    // allows monomorphicity.
    Handle<TypeFeedbackVector> feedback_vector = Handle<TypeFeedbackVector>(
        createObj->feedback_vector(), CcTest::i_isolate());
    for (int i = 0; i < 20; i++) {
      Object* slot_value = feedback_vector->Get(FeedbackVectorSlot(0));
      CHECK(slot_value->IsWeakCell());
      if (WeakCell::cast(slot_value)->cleared()) break;
      heap->CollectAllGarbage();
    }
  
    Object* slot_value = feedback_vector->Get(FeedbackVectorSlot(0));
    CHECK(slot_value->IsWeakCell() && WeakCell::cast(slot_value)->cleared());
    CompileRun(
        "function coat() { this.x = 6; }"
        "createObj(coat);");
    slot_value = feedback_vector->Get(FeedbackVectorSlot(0));
    CHECK(slot_value->IsWeakCell() && !WeakCell::cast(slot_value)->cleared());
  }
  
  
  // Checks that the value returned by execution of the source is weak.
  void CheckWeakness(const char* source) {
    i::FLAG_stress_compaction = false;
    CcTest::InitializeVM();
    v8::Isolate* isolate = CcTest::isolate();
    LocalContext env;
    v8::HandleScope scope(isolate);
    v8::Persistent<v8::Object> garbage;
    {
      v8::HandleScope scope(isolate);
      garbage.Reset(isolate, CompileRun(env.local(), source)
                                 .ToLocalChecked()
                                 ->ToObject(env.local())
                                 .ToLocalChecked());
    }
    weak_ic_cleared = false;
    garbage.SetWeak(&garbage, &ClearWeakIC, v8::WeakCallbackType::kParameter);
    Heap* heap = CcTest::i_isolate()->heap();
    heap->CollectAllGarbage();
    CHECK(weak_ic_cleared);
  }
  
  
  // Each of the following "weak IC" tests creates an IC that embeds a map with
  // the prototype pointing to _proto_ and checks that the _proto_ dies on GC.
  TEST(WeakMapInMonomorphicLoadIC) {
    CheckWeakness("function loadIC(obj) {"
                  "  return obj.name;"
                  "}"
                  " (function() {"
                  "   var proto = {'name' : 'weak'};"
                  "   var obj = Object.create(proto);"
                  "   loadIC(obj);"
                  "   loadIC(obj);"
                  "   loadIC(obj);"
                  "   return proto;"
                  " })();");
  }
  
  
  TEST(WeakMapInPolymorphicLoadIC) {
    CheckWeakness(
        "function loadIC(obj) {"
        "  return obj.name;"
        "}"
        " (function() {"
        "   var proto = {'name' : 'weak'};"
        "   var obj = Object.create(proto);"
        "   loadIC(obj);"
        "   loadIC(obj);"
        "   loadIC(obj);"
        "   var poly = Object.create(proto);"
        "   poly.x = true;"
        "   loadIC(poly);"
        "   return proto;"
        " })();");
  }
  
  
  TEST(WeakMapInMonomorphicKeyedLoadIC) {
    CheckWeakness("function keyedLoadIC(obj, field) {"
                  "  return obj[field];"
                  "}"
                  " (function() {"
                  "   var proto = {'name' : 'weak'};"
                  "   var obj = Object.create(proto);"
                  "   keyedLoadIC(obj, 'name');"
                  "   keyedLoadIC(obj, 'name');"
                  "   keyedLoadIC(obj, 'name');"
                  "   return proto;"
                  " })();");
  }
  
  
  TEST(WeakMapInPolymorphicKeyedLoadIC) {
    CheckWeakness(
        "function keyedLoadIC(obj, field) {"
        "  return obj[field];"
        "}"
        " (function() {"
        "   var proto = {'name' : 'weak'};"
        "   var obj = Object.create(proto);"
        "   keyedLoadIC(obj, 'name');"
        "   keyedLoadIC(obj, 'name');"
        "   keyedLoadIC(obj, 'name');"
        "   var poly = Object.create(proto);"
        "   poly.x = true;"
        "   keyedLoadIC(poly, 'name');"
        "   return proto;"
        " })();");
  }
  
  
  TEST(WeakMapInMonomorphicStoreIC) {
    CheckWeakness("function storeIC(obj, value) {"
                  "  obj.name = value;"
                  "}"
                  " (function() {"
                  "   var proto = {'name' : 'weak'};"
                  "   var obj = Object.create(proto);"
                  "   storeIC(obj, 'x');"
                  "   storeIC(obj, 'x');"
                  "   storeIC(obj, 'x');"
                  "   return proto;"
                  " })();");
  }
  
  
  TEST(WeakMapInPolymorphicStoreIC) {
    CheckWeakness(
        "function storeIC(obj, value) {"
        "  obj.name = value;"
        "}"
        " (function() {"
        "   var proto = {'name' : 'weak'};"
        "   var obj = Object.create(proto);"
        "   storeIC(obj, 'x');"
        "   storeIC(obj, 'x');"
        "   storeIC(obj, 'x');"
        "   var poly = Object.create(proto);"
        "   poly.x = true;"
        "   storeIC(poly, 'x');"
        "   return proto;"
        " })();");
  }
  
  
  TEST(WeakMapInMonomorphicKeyedStoreIC) {
    CheckWeakness("function keyedStoreIC(obj, field, value) {"
                  "  obj[field] = value;"
                  "}"
                  " (function() {"
                  "   var proto = {'name' : 'weak'};"
                  "   var obj = Object.create(proto);"
                  "   keyedStoreIC(obj, 'x');"
                  "   keyedStoreIC(obj, 'x');"
                  "   keyedStoreIC(obj, 'x');"
                  "   return proto;"
                  " })();");
  }
  
  
  TEST(WeakMapInPolymorphicKeyedStoreIC) {
    CheckWeakness(
        "function keyedStoreIC(obj, field, value) {"
        "  obj[field] = value;"
        "}"
        " (function() {"
        "   var proto = {'name' : 'weak'};"
        "   var obj = Object.create(proto);"
        "   keyedStoreIC(obj, 'x');"
        "   keyedStoreIC(obj, 'x');"
        "   keyedStoreIC(obj, 'x');"
        "   var poly = Object.create(proto);"
        "   poly.x = true;"
        "   keyedStoreIC(poly, 'x');"
        "   return proto;"
        " })();");
  }
  
  
  TEST(WeakMapInMonomorphicCompareNilIC) {
    CheckWeakness("function compareNilIC(obj) {"
                  "  return obj == null;"
                  "}"
                  " (function() {"
                  "   var proto = {'name' : 'weak'};"
                  "   var obj = Object.create(proto);"
                  "   compareNilIC(obj);"
                  "   compareNilIC(obj);"
                  "   compareNilIC(obj);"
                  "   return proto;"
                  " })();");
  }
  
  
  Handle<JSFunction> GetFunctionByName(Isolate* isolate, const char* name) {
    Handle<String> str = isolate->factory()->InternalizeUtf8String(name);
    Handle<Object> obj =
        Object::GetProperty(isolate->global_object(), str).ToHandleChecked();
    return Handle<JSFunction>::cast(obj);
  }
  
  void CheckIC(Handle<JSFunction> function, Code::Kind kind, int slot_index,
               InlineCacheState state) {
    if (kind == Code::LOAD_IC || kind == Code::KEYED_LOAD_IC ||
        kind == Code::CALL_IC) {
      TypeFeedbackVector* vector = function->feedback_vector();
      FeedbackVectorSlot slot(slot_index);
      if (kind == Code::LOAD_IC) {
        LoadICNexus nexus(vector, slot);
        CHECK_EQ(nexus.StateFromFeedback(), state);
      } else if (kind == Code::KEYED_LOAD_IC) {
        KeyedLoadICNexus nexus(vector, slot);
        CHECK_EQ(nexus.StateFromFeedback(), state);
      } else if (kind == Code::CALL_IC) {
        CallICNexus nexus(vector, slot);
        CHECK_EQ(nexus.StateFromFeedback(), state);
      }
    } else {
      Code* ic = FindFirstIC(function->code(), kind);
      CHECK(ic->is_inline_cache_stub());
      CHECK(!IC::ICUseVector(kind));
      CHECK_EQ(state, IC::StateFromCode(ic));
    }
  }
  
  
  TEST(MonomorphicStaysMonomorphicAfterGC) {
    if (FLAG_always_opt) return;
    CcTest::InitializeVM();
    Isolate* isolate = CcTest::i_isolate();
    Heap* heap = isolate->heap();
    v8::HandleScope scope(CcTest::isolate());
    CompileRun(
        "function loadIC(obj) {"
        "  return obj.name;"
        "}"
        "function testIC() {"
        "  var proto = {'name' : 'weak'};"
        "  var obj = Object.create(proto);"
        "  loadIC(obj);"
        "  loadIC(obj);"
        "  loadIC(obj);"
        "  return proto;"
        "};");
    Handle<JSFunction> loadIC = GetFunctionByName(isolate, "loadIC");
    {
      v8::HandleScope scope(CcTest::isolate());
      CompileRun("(testIC())");
    }
    heap->CollectAllGarbage();
    CheckIC(loadIC, Code::LOAD_IC, 0, MONOMORPHIC);
    {
      v8::HandleScope scope(CcTest::isolate());
      CompileRun("(testIC())");
    }
    CheckIC(loadIC, Code::LOAD_IC, 0, MONOMORPHIC);
  }
  
  
  TEST(PolymorphicStaysPolymorphicAfterGC) {
    if (FLAG_always_opt) return;
    CcTest::InitializeVM();
    Isolate* isolate = CcTest::i_isolate();
    Heap* heap = isolate->heap();
    v8::HandleScope scope(CcTest::isolate());
    CompileRun(
        "function loadIC(obj) {"
        "  return obj.name;"
        "}"
        "function testIC() {"
        "  var proto = {'name' : 'weak'};"
        "  var obj = Object.create(proto);"
        "  loadIC(obj);"
        "  loadIC(obj);"
        "  loadIC(obj);"
        "  var poly = Object.create(proto);"
        "  poly.x = true;"
        "  loadIC(poly);"
        "  return proto;"
        "};");
    Handle<JSFunction> loadIC = GetFunctionByName(isolate, "loadIC");
    {
      v8::HandleScope scope(CcTest::isolate());
      CompileRun("(testIC())");
    }
    heap->CollectAllGarbage();
    CheckIC(loadIC, Code::LOAD_IC, 0, POLYMORPHIC);
    {
      v8::HandleScope scope(CcTest::isolate());
      CompileRun("(testIC())");
    }
    CheckIC(loadIC, Code::LOAD_IC, 0, POLYMORPHIC);
  }
  
  
  TEST(WeakCell) {
    CcTest::InitializeVM();
    Isolate* isolate = CcTest::i_isolate();
    v8::internal::Heap* heap = CcTest::heap();
    v8::internal::Factory* factory = isolate->factory();
  
    HandleScope outer_scope(isolate);
    Handle<WeakCell> weak_cell1;
    {
      HandleScope inner_scope(isolate);
      Handle<HeapObject> value = factory->NewFixedArray(1, NOT_TENURED);
      weak_cell1 = inner_scope.CloseAndEscape(factory->NewWeakCell(value));
    }
  
    Handle<FixedArray> survivor = factory->NewFixedArray(1, NOT_TENURED);
    Handle<WeakCell> weak_cell2;
    {
      HandleScope inner_scope(isolate);
      weak_cell2 = inner_scope.CloseAndEscape(factory->NewWeakCell(survivor));
    }
    CHECK(weak_cell1->value()->IsFixedArray());
    CHECK_EQ(*survivor, weak_cell2->value());
    heap->CollectGarbage(NEW_SPACE);
    CHECK(weak_cell1->value()->IsFixedArray());
    CHECK_EQ(*survivor, weak_cell2->value());
    heap->CollectGarbage(NEW_SPACE);
    CHECK(weak_cell1->value()->IsFixedArray());
    CHECK_EQ(*survivor, weak_cell2->value());
    heap->CollectAllAvailableGarbage();
    CHECK(weak_cell1->cleared());
    CHECK_EQ(*survivor, weak_cell2->value());
  }
  
  
  TEST(WeakCellsWithIncrementalMarking) {
    CcTest::InitializeVM();
    Isolate* isolate = CcTest::i_isolate();
    v8::internal::Heap* heap = CcTest::heap();
    v8::internal::Factory* factory = isolate->factory();
  
    const int N = 16;
    HandleScope outer_scope(isolate);
    Handle<FixedArray> survivor = factory->NewFixedArray(1, NOT_TENURED);
    Handle<WeakCell> weak_cells[N];
  
    for (int i = 0; i < N; i++) {
      HandleScope inner_scope(isolate);
      Handle<HeapObject> value =
          i == 0 ? survivor : factory->NewFixedArray(1, NOT_TENURED);
      Handle<WeakCell> weak_cell = factory->NewWeakCell(value);
      CHECK(weak_cell->value()->IsFixedArray());
      IncrementalMarking* marking = heap->incremental_marking();
      if (marking->IsStopped()) {
        heap->StartIncrementalMarking();
      }
      marking->Step(128, IncrementalMarking::NO_GC_VIA_STACK_GUARD);
      heap->CollectGarbage(NEW_SPACE);
      CHECK(weak_cell->value()->IsFixedArray());
      weak_cells[i] = inner_scope.CloseAndEscape(weak_cell);
    }
    // Call collect all twice to make sure that we also cleared
    // weak cells that were allocated on black pages.
    heap->CollectAllGarbage();
    heap->CollectAllGarbage();
    CHECK_EQ(*survivor, weak_cells[0]->value());
    for (int i = 1; i < N; i++) {
      CHECK(weak_cells[i]->cleared());
    }
  }
  
  
  #ifdef DEBUG
  TEST(AddInstructionChangesNewSpacePromotion) {
    i::FLAG_allow_natives_syntax = true;
    i::FLAG_expose_gc = true;
    i::FLAG_stress_compaction = true;
    i::FLAG_gc_interval = 1000;
    CcTest::InitializeVM();
    if (!i::FLAG_allocation_site_pretenuring) return;
    v8::HandleScope scope(CcTest::isolate());
    Isolate* isolate = CcTest::i_isolate();
    Heap* heap = isolate->heap();
    LocalContext env;
    CompileRun(
        "function add(a, b) {"
        "  return a + b;"
        "}"
        "add(1, 2);"
        "add(\"a\", \"b\");"
        "var oldSpaceObject;"
        "gc();"
        "function crash(x) {"
        "  var object = {a: null, b: null};"
        "  var result = add(1.5, x | 0);"
        "  object.a = result;"
        "  oldSpaceObject = object;"
        "  return object;"
        "}"
        "crash(1);"
        "crash(1);"
        "%OptimizeFunctionOnNextCall(crash);"
        "crash(1);");
  
    v8::Local<v8::Object> global = CcTest::global();
    v8::Local<v8::Function> g = v8::Local<v8::Function>::Cast(
        global->Get(env.local(), v8_str("crash")).ToLocalChecked());
    v8::Local<v8::Value> args1[] = {v8_num(1)};
    heap->DisableInlineAllocation();
    heap->set_allocation_timeout(1);
    g->Call(env.local(), global, 1, args1).ToLocalChecked();
    heap->CollectAllGarbage();
  }
  
  
  void OnFatalErrorExpectOOM(const char* location, const char* message) {
    // Exit with 0 if the location matches our expectation.
    exit(strcmp(location, "CALL_AND_RETRY_LAST"));
  }
  
  
  TEST(CEntryStubOOM) {
    i::FLAG_allow_natives_syntax = true;
    CcTest::InitializeVM();
    v8::HandleScope scope(CcTest::isolate());
    CcTest::isolate()->SetFatalErrorHandler(OnFatalErrorExpectOOM);
  
    v8::Local<v8::Value> result = CompileRun(
        "%SetFlags('--gc-interval=1');"
        "var a = [];"
        "a.__proto__ = [];"
        "a.unshift(1)");
  
    CHECK(result->IsNumber());
  }
  
  #endif  // DEBUG
  
  
  static void InterruptCallback357137(v8::Isolate* isolate, void* data) { }
  
  
  static void RequestInterrupt(const v8::FunctionCallbackInfo<v8::Value>& args) {
    CcTest::isolate()->RequestInterrupt(&InterruptCallback357137, NULL);
  }
  
  
  UNINITIALIZED_TEST(Regress538257) {
    i::FLAG_manual_evacuation_candidates_selection = true;
    v8::Isolate::CreateParams create_params;
    // Set heap limits.
    create_params.constraints.set_max_semi_space_size(1 * Page::kPageSize / MB);
    create_params.constraints.set_max_old_space_size(6 * Page::kPageSize / MB);
    create_params.array_buffer_allocator = CcTest::array_buffer_allocator();
    v8::Isolate* isolate = v8::Isolate::New(create_params);
    isolate->Enter();
    {
      i::Isolate* i_isolate = reinterpret_cast<i::Isolate*>(isolate);
      Heap* heap = i_isolate->heap();
      HandleScope handle_scope(i_isolate);
      PagedSpace* old_space = heap->old_space();
      const int kMaxObjects = 10000;
      const int kFixedArrayLen = 512;
      Handle<FixedArray> objects[kMaxObjects];
      for (int i = 0; (i < kMaxObjects) &&
                      heap->CanExpandOldGeneration(old_space->AreaSize());
           i++) {
        objects[i] = i_isolate->factory()->NewFixedArray(kFixedArrayLen, TENURED);
        Page::FromAddress(objects[i]->address())
            ->SetFlag(MemoryChunk::FORCE_EVACUATION_CANDIDATE_FOR_TESTING);
      }
      heap::SimulateFullSpace(old_space);
      heap->CollectGarbage(OLD_SPACE);
      // If we get this far, we've successfully aborted compaction. Any further
      // allocations might trigger OOM.
    }
    isolate->Exit();
    isolate->Dispose();
  }
  
  
  TEST(Regress357137) {
    CcTest::InitializeVM();
    v8::Isolate* isolate = CcTest::isolate();
    v8::HandleScope hscope(isolate);
    v8::Local<v8::ObjectTemplate> global = v8::ObjectTemplate::New(isolate);
    global->Set(
        v8::String::NewFromUtf8(isolate, "interrupt", v8::NewStringType::kNormal)
            .ToLocalChecked(),
        v8::FunctionTemplate::New(isolate, RequestInterrupt));
    v8::Local<v8::Context> context = v8::Context::New(isolate, NULL, global);
    CHECK(!context.IsEmpty());
    v8::Context::Scope cscope(context);
  
    v8::Local<v8::Value> result = CompileRun(
        "var locals = '';"
        "for (var i = 0; i < 512; i++) locals += 'var v' + i + '= 42;';"
        "eval('function f() {' + locals + 'return function() { return v0; }; }');"
        "interrupt();"  // This triggers a fake stack overflow in f.
        "f()()");
    CHECK_EQ(42.0, result->ToNumber(context).ToLocalChecked()->Value());
  }
  
  
  TEST(Regress507979) {
    const int kFixedArrayLen = 10;
    CcTest::InitializeVM();
    Isolate* isolate = CcTest::i_isolate();
    Heap* heap = isolate->heap();
    HandleScope handle_scope(isolate);
  
    Handle<FixedArray> o1 = isolate->factory()->NewFixedArray(kFixedArrayLen);
    Handle<FixedArray> o2 = isolate->factory()->NewFixedArray(kFixedArrayLen);
    CHECK(heap->InNewSpace(*o1));
    CHECK(heap->InNewSpace(*o2));
  
    HeapIterator it(heap, i::HeapIterator::kFilterUnreachable);
  
    // Replace parts of an object placed before a live object with a filler. This
    // way the filler object shares the mark bits with the following live object.
    o1->Shrink(kFixedArrayLen - 1);
  
    for (HeapObject* obj = it.next(); obj != NULL; obj = it.next()) {
      // Let's not optimize the loop away.
      CHECK(obj->address() != nullptr);
    }
  }
  
  
  UNINITIALIZED_TEST(PromotionQueue) {
    i::FLAG_expose_gc = true;
    i::FLAG_max_semi_space_size = 2 * Page::kPageSize / MB;
    i::FLAG_min_semi_space_size = i::FLAG_max_semi_space_size;
    v8::Isolate::CreateParams create_params;
    create_params.array_buffer_allocator = CcTest::array_buffer_allocator();
    v8::Isolate* isolate = v8::Isolate::New(create_params);
    i::Isolate* i_isolate = reinterpret_cast<i::Isolate*>(isolate);
    {
      v8::Isolate::Scope isolate_scope(isolate);
      v8::HandleScope handle_scope(isolate);
      v8::Context::New(isolate)->Enter();
      Heap* heap = i_isolate->heap();
      NewSpace* new_space = heap->new_space();
  
      // In this test we will try to overwrite the promotion queue which is at the
      // end of to-space. To actually make that possible, we need at least two
      // semi-space pages and take advantage of fragmentation.
      // (1) Use a semi-space consisting of two pages.
      // (2) Create a few small long living objects and call the scavenger to
      // move them to the other semi-space.
      // (3) Create a huge object, i.e., remainder of first semi-space page and
      // create another huge object which should be of maximum allocatable memory
      // size of the second semi-space page.
      // (4) Call the scavenger again.
      // What will happen is: the scavenger will promote the objects created in
      // (2) and will create promotion queue entries at the end of the second
      // semi-space page during the next scavenge when it promotes the objects to
      // the old generation. The first allocation of (3) will fill up the first
      // semi-space page. The second allocation in (3) will not fit into the
      // first semi-space page, but it will overwrite the promotion queue which
      // are in the second semi-space page. If the right guards are in place, the
      // promotion queue will be evacuated in that case.
  
  
      CHECK(new_space->IsAtMaximumCapacity());
      CHECK(i::FLAG_min_semi_space_size * MB == new_space->TotalCapacity());
  
      // Call the scavenger two times to get an empty new space
      heap->CollectGarbage(NEW_SPACE);
      heap->CollectGarbage(NEW_SPACE);
  
      // First create a few objects which will survive a scavenge, and will get
      // promoted to the old generation later on. These objects will create
      // promotion queue entries at the end of the second semi-space page.
      const int number_handles = 12;
      Handle<FixedArray> handles[number_handles];
      for (int i = 0; i < number_handles; i++) {
        handles[i] = i_isolate->factory()->NewFixedArray(1, NOT_TENURED);
      }
  
      heap->CollectGarbage(NEW_SPACE);
      CHECK(i::FLAG_min_semi_space_size * MB == new_space->TotalCapacity());
  
      // Fill-up the first semi-space page.
      heap::FillUpOnePage(new_space);
  
      // Create a small object to initialize the bump pointer on the second
      // semi-space page.
      Handle<FixedArray> small =
          i_isolate->factory()->NewFixedArray(1, NOT_TENURED);
      CHECK(heap->InNewSpace(*small));
  
      // Fill-up the second semi-space page.
      heap::FillUpOnePage(new_space);
  
      // This scavenge will corrupt memory if the promotion queue is not
      // evacuated.
      heap->CollectGarbage(NEW_SPACE);
    }
    isolate->Dispose();
  }
  
  
  TEST(Regress388880) {
    i::FLAG_expose_gc = true;
    CcTest::InitializeVM();
    v8::HandleScope scope(CcTest::isolate());
    Isolate* isolate = CcTest::i_isolate();
    Factory* factory = isolate->factory();
    Heap* heap = isolate->heap();
  
    Handle<Map> map1 = Map::Create(isolate, 1);
    Handle<String> name = factory->NewStringFromStaticChars("foo");
    name = factory->InternalizeString(name);
    Handle<Map> map2 =
        Map::CopyWithField(map1, name, FieldType::Any(isolate), NONE,
                           Representation::Tagged(), OMIT_TRANSITION)
            .ToHandleChecked();
  
    int desired_offset = Page::kPageSize - map1->instance_size();
  
    // Allocate padding objects in old pointer space so, that object allocated
    // afterwards would end at the end of the page.
    heap::SimulateFullSpace(heap->old_space());
    int padding_size = desired_offset - Page::kObjectStartOffset;
    heap::CreatePadding(heap, padding_size, TENURED);
  
    Handle<JSObject> o = factory->NewJSObjectFromMap(map1, TENURED);
    o->set_properties(*factory->empty_fixed_array());
  
    // Ensure that the object allocated where we need it.
    Page* page = Page::FromAddress(o->address());
    CHECK_EQ(desired_offset, page->Offset(o->address()));
  
    // Now we have an object right at the end of the page.
  
    // Enable incremental marking to trigger actions in Heap::AdjustLiveBytes()
    // that would cause crash.
    IncrementalMarking* marking = CcTest::heap()->incremental_marking();
    marking->Stop();
    CcTest::heap()->StartIncrementalMarking();
    CHECK(marking->IsMarking());
  
    // Now everything is set up for crashing in JSObject::MigrateFastToFast()
    // when it calls heap->AdjustLiveBytes(...).
    JSObject::MigrateToMap(o, map2);
  }
  
  
  TEST(Regress3631) {
    i::FLAG_expose_gc = true;
    CcTest::InitializeVM();
    v8::HandleScope scope(CcTest::isolate());
    Isolate* isolate = CcTest::i_isolate();
    Heap* heap = isolate->heap();
    IncrementalMarking* marking = CcTest::heap()->incremental_marking();
    v8::Local<v8::Value> result = CompileRun(
        "var weak_map = new WeakMap();"
        "var future_keys = [];"
        "for (var i = 0; i < 50; i++) {"
        "  var key = {'k' : i + 0.1};"
        "  weak_map.set(key, 1);"
        "  future_keys.push({'x' : i + 0.2});"
        "}"
        "weak_map");
    if (marking->IsStopped()) {
      CcTest::heap()->StartIncrementalMarking();
    }
    // Incrementally mark the backing store.
    Handle<JSReceiver> obj =
        v8::Utils::OpenHandle(*v8::Local<v8::Object>::Cast(result));
    Handle<JSWeakCollection> weak_map(reinterpret_cast<JSWeakCollection*>(*obj));
    while (!Marking::IsBlack(
               ObjectMarking::MarkBitFrom(HeapObject::cast(weak_map->table()))) &&
           !marking->IsStopped()) {
      marking->Step(MB, IncrementalMarking::NO_GC_VIA_STACK_GUARD);
    }
    // Stash the backing store in a handle.
    Handle<Object> save(weak_map->table(), isolate);
    // The following line will update the backing store.
    CompileRun(
        "for (var i = 0; i < 50; i++) {"
        "  weak_map.set(future_keys[i], i);"
        "}");
    heap->incremental_marking()->set_should_hurry(true);
    heap->CollectGarbage(OLD_SPACE);
  }
  
  
  TEST(Regress442710) {
    CcTest::InitializeVM();
    Isolate* isolate = CcTest::i_isolate();
    Heap* heap = isolate->heap();
    Factory* factory = isolate->factory();
  
    HandleScope sc(isolate);
    Handle<JSGlobalObject> global(
        CcTest::i_isolate()->context()->global_object());
    Handle<JSArray> array = factory->NewJSArray(2);
  
    Handle<String> name = factory->InternalizeUtf8String("testArray");
    JSReceiver::SetProperty(global, name, array, SLOPPY).Check();
    CompileRun("testArray[0] = 1; testArray[1] = 2; testArray.shift();");
    heap->CollectGarbage(OLD_SPACE);
  }
  
  
  HEAP_TEST(NumberStringCacheSize) {
    // Test that the number-string cache has not been resized in the snapshot.
    CcTest::InitializeVM();
    Isolate* isolate = CcTest::i_isolate();
    if (!isolate->snapshot_available()) return;
    Heap* heap = isolate->heap();
    CHECK_EQ(Heap::kInitialNumberStringCacheSize * 2,
             heap->number_string_cache()->length());
  }
  
  
  TEST(Regress3877) {
    CcTest::InitializeVM();
    Isolate* isolate = CcTest::i_isolate();
    Heap* heap = isolate->heap();
    Factory* factory = isolate->factory();
    HandleScope scope(isolate);
    CompileRun("function cls() { this.x = 10; }");
    Handle<WeakCell> weak_prototype;
    {
      HandleScope inner_scope(isolate);
      v8::Local<v8::Value> result = CompileRun("cls.prototype");
      Handle<JSReceiver> proto =
          v8::Utils::OpenHandle(*v8::Local<v8::Object>::Cast(result));
      weak_prototype = inner_scope.CloseAndEscape(factory->NewWeakCell(proto));
    }
    CHECK(!weak_prototype->cleared());
    CompileRun(
        "var a = { };"
        "a.x = new cls();"
        "cls.prototype = null;");
    for (int i = 0; i < 4; i++) {
      heap->CollectAllGarbage();
    }
    // The map of a.x keeps prototype alive
    CHECK(!weak_prototype->cleared());
    // Change the map of a.x and make the previous map garbage collectable.
    CompileRun("a.x.__proto__ = {};");
    for (int i = 0; i < 4; i++) {
      heap->CollectAllGarbage();
    }
    CHECK(weak_prototype->cleared());
  }
  
  
  Handle<WeakCell> AddRetainedMap(Isolate* isolate, Heap* heap) {
      HandleScope inner_scope(isolate);
      Handle<Map> map = Map::Create(isolate, 1);
      v8::Local<v8::Value> result =
          CompileRun("(function () { return {x : 10}; })();");
      Handle<JSReceiver> proto =
          v8::Utils::OpenHandle(*v8::Local<v8::Object>::Cast(result));
      Map::SetPrototype(map, proto);
      heap->AddRetainedMap(map);
      return inner_scope.CloseAndEscape(Map::WeakCellForMap(map));
  }
  
  
  void CheckMapRetainingFor(int n) {
    FLAG_retain_maps_for_n_gc = n;
    Isolate* isolate = CcTest::i_isolate();
    Heap* heap = isolate->heap();
    Handle<WeakCell> weak_cell = AddRetainedMap(isolate, heap);
    CHECK(!weak_cell->cleared());
    for (int i = 0; i < n; i++) {
      heap::SimulateIncrementalMarking(heap);
      heap->CollectGarbage(OLD_SPACE);
    }
    CHECK(!weak_cell->cleared());
    heap::SimulateIncrementalMarking(heap);
    heap->CollectGarbage(OLD_SPACE);
    CHECK(weak_cell->cleared());
  }
  
  
  TEST(MapRetaining) {
    CcTest::InitializeVM();
    v8::HandleScope scope(CcTest::isolate());
    CheckMapRetainingFor(FLAG_retain_maps_for_n_gc);
    CheckMapRetainingFor(0);
    CheckMapRetainingFor(1);
    CheckMapRetainingFor(7);
  }
  
  
  TEST(RegressArrayListGC) {
    FLAG_retain_maps_for_n_gc = 1;
    FLAG_incremental_marking = 0;
    FLAG_gc_global = true;
    CcTest::InitializeVM();
    v8::HandleScope scope(CcTest::isolate());
    Isolate* isolate = CcTest::i_isolate();
    Heap* heap = isolate->heap();
    AddRetainedMap(isolate, heap);
    Handle<Map> map = Map::Create(isolate, 1);
    heap->CollectGarbage(OLD_SPACE);
    // Force GC in old space on next addition of retained map.
    Map::WeakCellForMap(map);
    heap::SimulateFullSpace(CcTest::heap()->new_space());
    for (int i = 0; i < 10; i++) {
      heap->AddRetainedMap(map);
    }
    heap->CollectGarbage(OLD_SPACE);
  }
  
  
  #ifdef DEBUG
  TEST(PathTracer) {
    CcTest::InitializeVM();
    v8::HandleScope scope(CcTest::isolate());
  
    v8::Local<v8::Value> result = CompileRun("'abc'");
    Handle<Object> o = v8::Utils::OpenHandle(*result);
    CcTest::i_isolate()->heap()->TracePathToObject(*o);
  }
  #endif  // DEBUG
  
  
  TEST(WritableVsImmortalRoots) {
    for (int i = 0; i < Heap::kStrongRootListLength; ++i) {
      Heap::RootListIndex root_index = static_cast<Heap::RootListIndex>(i);
      bool writable = Heap::RootCanBeWrittenAfterInitialization(root_index);
      bool immortal = Heap::RootIsImmortalImmovable(root_index);
      // A root value can be writable, immortal, or neither, but not both.
      CHECK(!immortal || !writable);
    }
  }
  
  
  static void TestRightTrimFixedTypedArray(i::ExternalArrayType type,
                                           int initial_length,
                                           int elements_to_trim) {
    v8::HandleScope scope(CcTest::isolate());
    Isolate* isolate = CcTest::i_isolate();
    Factory* factory = isolate->factory();
    Heap* heap = isolate->heap();
  
    Handle<FixedTypedArrayBase> array =
        factory->NewFixedTypedArray(initial_length, type, true);
    int old_size = array->size();
    heap->RightTrimFixedArray<Heap::CONCURRENT_TO_SWEEPER>(*array,
                                                           elements_to_trim);
  
    // Check that free space filler is at the right place and did not smash the
    // array header.
    CHECK(array->IsFixedArrayBase());
    CHECK_EQ(initial_length - elements_to_trim, array->length());
    int new_size = array->size();
    if (new_size != old_size) {
      // Free space filler should be created in this case.
      Address next_obj_address = array->address() + array->size();
      CHECK(HeapObject::FromAddress(next_obj_address)->IsFiller());
    }
    heap->CollectAllAvailableGarbage();
  }
  
  
  TEST(Regress472513) {
    CcTest::InitializeVM();
    v8::HandleScope scope(CcTest::isolate());
  
    // The combination of type/initial_length/elements_to_trim triggered
    // typed array header smashing with free space filler (crbug/472513).
  
    // 64-bit cases.
    TestRightTrimFixedTypedArray(i::kExternalUint8Array, 32, 6);
    TestRightTrimFixedTypedArray(i::kExternalUint8Array, 32 - 7, 6);
    TestRightTrimFixedTypedArray(i::kExternalUint16Array, 16, 6);
    TestRightTrimFixedTypedArray(i::kExternalUint16Array, 16 - 3, 6);
    TestRightTrimFixedTypedArray(i::kExternalUint32Array, 8, 6);
    TestRightTrimFixedTypedArray(i::kExternalUint32Array, 8 - 1, 6);
  
    // 32-bit cases.
    TestRightTrimFixedTypedArray(i::kExternalUint8Array, 16, 3);
    TestRightTrimFixedTypedArray(i::kExternalUint8Array, 16 - 3, 3);
    TestRightTrimFixedTypedArray(i::kExternalUint16Array, 8, 3);
    TestRightTrimFixedTypedArray(i::kExternalUint16Array, 8 - 1, 3);
    TestRightTrimFixedTypedArray(i::kExternalUint32Array, 4, 3);
  }
  
  
  TEST(WeakFixedArray) {
    CcTest::InitializeVM();
    v8::HandleScope scope(CcTest::isolate());
  
    Handle<HeapNumber> number = CcTest::i_isolate()->factory()->NewHeapNumber(1);
    Handle<WeakFixedArray> array = WeakFixedArray::Add(Handle<Object>(), number);
    array->Remove(number);
    array->Compact<WeakFixedArray::NullCallback>();
    WeakFixedArray::Add(array, number);
  }
  
  
  TEST(PreprocessStackTrace) {
    // Do not automatically trigger early GC.
    FLAG_gc_interval = -1;
    CcTest::InitializeVM();
    v8::HandleScope scope(CcTest::isolate());
    v8::TryCatch try_catch(CcTest::isolate());
    CompileRun("throw new Error();");
    CHECK(try_catch.HasCaught());
    Isolate* isolate = CcTest::i_isolate();
    Handle<Object> exception = v8::Utils::OpenHandle(*try_catch.Exception());
    Handle<Name> key = isolate->factory()->stack_trace_symbol();
    Handle<Object> stack_trace =
        Object::GetProperty(exception, key).ToHandleChecked();
    Handle<Object> code =
        Object::GetElement(isolate, stack_trace, 3).ToHandleChecked();
    CHECK(code->IsCode());
  
    isolate->heap()->CollectAllAvailableGarbage("stack trace preprocessing");
  
    Handle<Object> pos =
        Object::GetElement(isolate, stack_trace, 3).ToHandleChecked();
    CHECK(pos->IsSmi());
  
    Handle<JSArray> stack_trace_array = Handle<JSArray>::cast(stack_trace);
    int array_length = Smi::cast(stack_trace_array->length())->value();
    for (int i = 0; i < array_length; i++) {
      Handle<Object> element =
          Object::GetElement(isolate, stack_trace, i).ToHandleChecked();
      CHECK(!element->IsCode());
    }
  }
  
  
  static bool utils_has_been_collected = false;
  
  static void UtilsHasBeenCollected(
      const v8::WeakCallbackInfo<v8::Persistent<v8::Object>>& data) {
    utils_has_been_collected = true;
    data.GetParameter()->Reset();
  }
  
  
  TEST(BootstrappingExports) {
    // Expose utils object and delete it to observe that it is indeed
    // being garbage-collected.
    FLAG_expose_natives_as = "utils";
    CcTest::InitializeVM();
    v8::Isolate* isolate = CcTest::isolate();
    LocalContext env;
  
    if (Snapshot::HasContextSnapshot(CcTest::i_isolate(), 0)) return;
  
    utils_has_been_collected = false;
  
    v8::Persistent<v8::Object> utils;
  
    {
      v8::HandleScope scope(isolate);
      v8::Local<v8::String> name = v8_str("utils");
      utils.Reset(isolate, CcTest::global()
                               ->Get(env.local(), name)
                               .ToLocalChecked()
                               ->ToObject(env.local())
                               .ToLocalChecked());
      CHECK(CcTest::global()->Delete(env.local(), name).FromJust());
    }
  
    utils.SetWeak(&utils, UtilsHasBeenCollected,
                  v8::WeakCallbackType::kParameter);
  
    CcTest::heap()->CollectAllAvailableGarbage("fire weak callbacks");
  
    CHECK(utils_has_been_collected);
  }
  
  
  TEST(Regress1878) {
    FLAG_allow_natives_syntax = true;
    CcTest::InitializeVM();
    v8::Isolate* isolate = CcTest::isolate();
    v8::HandleScope scope(isolate);
    v8::Local<v8::Function> constructor = v8::Utils::CallableToLocal(
        CcTest::i_isolate()->internal_array_function());
    LocalContext env;
    CHECK(CcTest::global()
              ->Set(env.local(), v8_str("InternalArray"), constructor)
              .FromJust());
  
    v8::TryCatch try_catch(isolate);
  
    CompileRun(
        "var a = Array();"
        "for (var i = 0; i < 1000; i++) {"
        "  var ai = new InternalArray(10000);"
        "  if (%HaveSameMap(ai, a)) throw Error();"
        "  if (!%HasFastObjectElements(ai)) throw Error();"
        "}"
        "for (var i = 0; i < 1000; i++) {"
        "  var ai = new InternalArray(10000);"
        "  if (%HaveSameMap(ai, a)) throw Error();"
        "  if (!%HasFastObjectElements(ai)) throw Error();"
        "}");
  
    CHECK(!try_catch.HasCaught());
  }
  
  
  void AllocateInSpace(Isolate* isolate, size_t bytes, AllocationSpace space) {
    CHECK(bytes >= FixedArray::kHeaderSize);
    CHECK(bytes % kPointerSize == 0);
    Factory* factory = isolate->factory();
    HandleScope scope(isolate);
    AlwaysAllocateScope always_allocate(isolate);
    int elements =
        static_cast<int>((bytes - FixedArray::kHeaderSize) / kPointerSize);
    Handle<FixedArray> array = factory->NewFixedArray(
        elements, space == NEW_SPACE ? NOT_TENURED : TENURED);
    CHECK((space == NEW_SPACE) == isolate->heap()->InNewSpace(*array));
    CHECK_EQ(bytes, static_cast<size_t>(array->Size()));
  }
  
  
  TEST(NewSpaceAllocationCounter) {
    CcTest::InitializeVM();
    v8::HandleScope scope(CcTest::isolate());
    Isolate* isolate = CcTest::i_isolate();
    Heap* heap = isolate->heap();
    size_t counter1 = heap->NewSpaceAllocationCounter();
    heap->CollectGarbage(NEW_SPACE);
    const size_t kSize = 1024;
    AllocateInSpace(isolate, kSize, NEW_SPACE);
    size_t counter2 = heap->NewSpaceAllocationCounter();
    CHECK_EQ(kSize, counter2 - counter1);
    heap->CollectGarbage(NEW_SPACE);
    size_t counter3 = heap->NewSpaceAllocationCounter();
    CHECK_EQ(0U, counter3 - counter2);
    // Test counter overflow.
    size_t max_counter = -1;
    heap->set_new_space_allocation_counter(max_counter - 10 * kSize);
    size_t start = heap->NewSpaceAllocationCounter();
    for (int i = 0; i < 20; i++) {
      AllocateInSpace(isolate, kSize, NEW_SPACE);
      size_t counter = heap->NewSpaceAllocationCounter();
      CHECK_EQ(kSize, counter - start);
      start = counter;
    }
  }
  
  
  TEST(OldSpaceAllocationCounter) {
    CcTest::InitializeVM();
    v8::HandleScope scope(CcTest::isolate());
    Isolate* isolate = CcTest::i_isolate();
    Heap* heap = isolate->heap();
    size_t counter1 = heap->OldGenerationAllocationCounter();
    heap->CollectGarbage(NEW_SPACE);
    heap->CollectGarbage(NEW_SPACE);
    const size_t kSize = 1024;
    AllocateInSpace(isolate, kSize, OLD_SPACE);
    size_t counter2 = heap->OldGenerationAllocationCounter();
    // TODO(ulan): replace all CHECK_LE with CHECK_EQ after v8:4148 is fixed.
    CHECK_LE(kSize, counter2 - counter1);
    heap->CollectGarbage(NEW_SPACE);
    size_t counter3 = heap->OldGenerationAllocationCounter();
    CHECK_EQ(0u, counter3 - counter2);
    AllocateInSpace(isolate, kSize, OLD_SPACE);
    heap->CollectGarbage(OLD_SPACE);
    size_t counter4 = heap->OldGenerationAllocationCounter();
    CHECK_LE(kSize, counter4 - counter3);
    // Test counter overflow.
    size_t max_counter = -1;
    heap->set_old_generation_allocation_counter(max_counter - 10 * kSize);
    size_t start = heap->OldGenerationAllocationCounter();
    for (int i = 0; i < 20; i++) {
      AllocateInSpace(isolate, kSize, OLD_SPACE);
      size_t counter = heap->OldGenerationAllocationCounter();
      CHECK_LE(kSize, counter - start);
      start = counter;
    }
  }
  
  
  TEST(NewSpaceAllocationThroughput) {
    CcTest::InitializeVM();
    v8::HandleScope scope(CcTest::isolate());
    Isolate* isolate = CcTest::i_isolate();
    Heap* heap = isolate->heap();
    GCTracer* tracer = heap->tracer();
    tracer->ResetForTesting();
    int time1 = 100;
    size_t counter1 = 1000;
    tracer->SampleAllocation(time1, counter1, 0);
    int time2 = 200;
    size_t counter2 = 2000;
    tracer->SampleAllocation(time2, counter2, 0);
    size_t throughput =
        tracer->NewSpaceAllocationThroughputInBytesPerMillisecond();
    CHECK_EQ((counter2 - counter1) / (time2 - time1), throughput);
    int time3 = 1000;
    size_t counter3 = 30000;
    tracer->SampleAllocation(time3, counter3, 0);
    throughput = tracer->NewSpaceAllocationThroughputInBytesPerMillisecond();
    CHECK_EQ((counter3 - counter1) / (time3 - time1), throughput);
  }
  
  
  TEST(NewSpaceAllocationThroughput2) {
    CcTest::InitializeVM();
    v8::HandleScope scope(CcTest::isolate());
    Isolate* isolate = CcTest::i_isolate();
    Heap* heap = isolate->heap();
    GCTracer* tracer = heap->tracer();
    tracer->ResetForTesting();
    int time1 = 100;
    size_t counter1 = 1000;
    tracer->SampleAllocation(time1, counter1, 0);
    int time2 = 200;
    size_t counter2 = 2000;
    tracer->SampleAllocation(time2, counter2, 0);
    size_t throughput =
        tracer->NewSpaceAllocationThroughputInBytesPerMillisecond(100);
    CHECK_EQ((counter2 - counter1) / (time2 - time1), throughput);
    int time3 = 1000;
    size_t counter3 = 30000;
    tracer->SampleAllocation(time3, counter3, 0);
    throughput = tracer->NewSpaceAllocationThroughputInBytesPerMillisecond(100);
    CHECK_EQ((counter3 - counter1) / (time3 - time1), throughput);
  }
  
  
  static void CheckLeak(const v8::FunctionCallbackInfo<v8::Value>& args) {
    Isolate* isolate = CcTest::i_isolate();
    Object* message =
        *reinterpret_cast<Object**>(isolate->pending_message_obj_address());
    CHECK(message->IsTheHole(isolate));
  }
  
  
  TEST(MessageObjectLeak) {
    CcTest::InitializeVM();
    v8::Isolate* isolate = CcTest::isolate();
    v8::HandleScope scope(isolate);
    v8::Local<v8::ObjectTemplate> global = v8::ObjectTemplate::New(isolate);
    global->Set(
        v8::String::NewFromUtf8(isolate, "check", v8::NewStringType::kNormal)
            .ToLocalChecked(),
        v8::FunctionTemplate::New(isolate, CheckLeak));
    v8::Local<v8::Context> context = v8::Context::New(isolate, NULL, global);
    v8::Context::Scope cscope(context);
  
    const char* test =
        "try {"
        "  throw 'message 1';"
        "} catch (e) {"
        "}"
        "check();"
        "L: try {"
        "  throw 'message 2';"
        "} finally {"
        "  break L;"
        "}"
        "check();";
    CompileRun(test);
  
    const char* flag = "--turbo-filter=*";
    FlagList::SetFlagsFromString(flag, StrLength(flag));
    FLAG_always_opt = true;
  
    CompileRun(test);
  }
  
  
  static void CheckEqualSharedFunctionInfos(
      const v8::FunctionCallbackInfo<v8::Value>& args) {
    Handle<Object> obj1 = v8::Utils::OpenHandle(*args[0]);
    Handle<Object> obj2 = v8::Utils::OpenHandle(*args[1]);
    Handle<JSFunction> fun1 = Handle<JSFunction>::cast(obj1);
    Handle<JSFunction> fun2 = Handle<JSFunction>::cast(obj2);
    CHECK(fun1->shared() == fun2->shared());
  }
  
  
  static void RemoveCodeAndGC(const v8::FunctionCallbackInfo<v8::Value>& args) {
    Isolate* isolate = CcTest::i_isolate();
    Handle<Object> obj = v8::Utils::OpenHandle(*args[0]);
    Handle<JSFunction> fun = Handle<JSFunction>::cast(obj);
    fun->ReplaceCode(*isolate->builtins()->CompileLazy());
    fun->shared()->ReplaceCode(*isolate->builtins()->CompileLazy());
    fun->shared()->ClearBytecodeArray();  // Bytecode is code too.
    isolate->heap()->CollectAllAvailableGarbage("remove code and gc");
  }
  
  
  TEST(CanonicalSharedFunctionInfo) {
    CcTest::InitializeVM();
    v8::Isolate* isolate = CcTest::isolate();
    v8::HandleScope scope(isolate);
    v8::Local<v8::ObjectTemplate> global = v8::ObjectTemplate::New(isolate);
    global->Set(isolate, "check", v8::FunctionTemplate::New(
                                      isolate, CheckEqualSharedFunctionInfos));
    global->Set(isolate, "remove",
                v8::FunctionTemplate::New(isolate, RemoveCodeAndGC));
    v8::Local<v8::Context> context = v8::Context::New(isolate, NULL, global);
    v8::Context::Scope cscope(context);
    CompileRun(
        "function f() { return function g() {}; }"
        "var g1 = f();"
        "remove(f);"
        "var g2 = f();"
        "check(g1, g2);");
  
    CompileRun(
        "function f() { return (function() { return function g() {}; })(); }"
        "var g1 = f();"
        "remove(f);"
        "var g2 = f();"
        "check(g1, g2);");
  }
  
  TEST(RemoveCodeFromSharedFunctionInfoButNotFromClosure) {
    CcTest::InitializeVM();
    v8::Isolate* isolate = CcTest::isolate();
    v8::HandleScope scope(isolate);
    v8::Local<v8::ObjectTemplate> global = v8::ObjectTemplate::New(isolate);
    global->Set(isolate, "check", v8::FunctionTemplate::New(
                                      isolate, CheckEqualSharedFunctionInfos));
    global->Set(isolate, "remove",
                v8::FunctionTemplate::New(isolate, RemoveCodeAndGC));
    v8::Local<v8::Context> context = v8::Context::New(isolate, NULL, global);
    v8::Context::Scope cscope(context);
    CompileRun(
        "function f() { return function g() {}; }"
        "var g1 = f();"
        "var g2 = f();"
        "check(g1, g2);"
        "g1();"
        "g2();"
        "remove(g1);"
        "g2();"
        "check(g1, g2);");
  }
  
  TEST(OldGenerationAllocationThroughput) {
    CcTest::InitializeVM();
    v8::HandleScope scope(CcTest::isolate());
    Isolate* isolate = CcTest::i_isolate();
    Heap* heap = isolate->heap();
    GCTracer* tracer = heap->tracer();
    tracer->ResetForTesting();
    int time1 = 100;
    size_t counter1 = 1000;
    tracer->SampleAllocation(time1, 0, counter1);
    int time2 = 200;
    size_t counter2 = 2000;
    tracer->SampleAllocation(time2, 0, counter2);
    size_t throughput = static_cast<size_t>(
        tracer->OldGenerationAllocationThroughputInBytesPerMillisecond(100));
    CHECK_EQ((counter2 - counter1) / (time2 - time1), throughput);
    int time3 = 1000;
    size_t counter3 = 30000;
    tracer->SampleAllocation(time3, 0, counter3);
    throughput = static_cast<size_t>(
        tracer->OldGenerationAllocationThroughputInBytesPerMillisecond(100));
    CHECK_EQ((counter3 - counter1) / (time3 - time1), throughput);
  }
  
  
  TEST(AllocationThroughput) {
    CcTest::InitializeVM();
    v8::HandleScope scope(CcTest::isolate());
    Isolate* isolate = CcTest::i_isolate();
    Heap* heap = isolate->heap();
    GCTracer* tracer = heap->tracer();
    tracer->ResetForTesting();
    int time1 = 100;
    size_t counter1 = 1000;
    tracer->SampleAllocation(time1, counter1, counter1);
    int time2 = 200;
    size_t counter2 = 2000;
    tracer->SampleAllocation(time2, counter2, counter2);
    size_t throughput = static_cast<size_t>(
        tracer->AllocationThroughputInBytesPerMillisecond(100));
    CHECK_EQ(2 * (counter2 - counter1) / (time2 - time1), throughput);
    int time3 = 1000;
    size_t counter3 = 30000;
    tracer->SampleAllocation(time3, counter3, counter3);
    throughput = tracer->AllocationThroughputInBytesPerMillisecond(100);
    CHECK_EQ(2 * (counter3 - counter1) / (time3 - time1), throughput);
  }
  
  
  TEST(ContextMeasure) {
    CcTest::InitializeVM();
    v8::HandleScope scope(CcTest::isolate());
    Isolate* isolate = CcTest::i_isolate();
    LocalContext context;
  
    int size_upper_limit = 0;
    int count_upper_limit = 0;
    HeapIterator it(CcTest::heap());
    for (HeapObject* obj = it.next(); obj != NULL; obj = it.next()) {
      size_upper_limit += obj->Size();
      count_upper_limit++;
    }
  
    ContextMeasure measure(*isolate->native_context());
  
    PrintF("Context size        : %d bytes\n", measure.Size());
    PrintF("Context object count: %d\n", measure.Count());
  
    CHECK_LE(1000, measure.Count());
    CHECK_LE(50000, measure.Size());
  
    CHECK_LE(measure.Count(), count_upper_limit);
    CHECK_LE(measure.Size(), size_upper_limit);
  }
  
  
  TEST(ScriptIterator) {
    CcTest::InitializeVM();
    v8::HandleScope scope(CcTest::isolate());
    Isolate* isolate = CcTest::i_isolate();
    Heap* heap = CcTest::heap();
    LocalContext context;
  
    heap->CollectAllGarbage();
  
    int script_count = 0;
    {
      HeapIterator it(heap);
      for (HeapObject* obj = it.next(); obj != NULL; obj = it.next()) {
        if (obj->IsScript()) script_count++;
      }
    }
  
    {
      Script::Iterator iterator(isolate);
      while (iterator.Next()) script_count--;
    }
  
    CHECK_EQ(0, script_count);
  }
  
  
  TEST(SharedFunctionInfoIterator) {
    CcTest::InitializeVM();
    v8::HandleScope scope(CcTest::isolate());
    Isolate* isolate = CcTest::i_isolate();
    Heap* heap = CcTest::heap();
    LocalContext context;
  
    heap->CollectAllGarbage();
    heap->CollectAllGarbage();
  
    int sfi_count = 0;
    {
      HeapIterator it(heap);
      for (HeapObject* obj = it.next(); obj != NULL; obj = it.next()) {
        if (!obj->IsSharedFunctionInfo()) continue;
        sfi_count++;
      }
    }
  
    {
      SharedFunctionInfo::Iterator iterator(isolate);
      while (iterator.Next()) sfi_count--;
    }
  
    CHECK_EQ(0, sfi_count);
  }
  
  
  template <typename T>
  static UniqueId MakeUniqueId(const Persistent<T>& p) {
    return UniqueId(reinterpret_cast<uintptr_t>(*v8::Utils::OpenPersistent(p)));
  }
  
  
  TEST(Regress519319) {
    CcTest::InitializeVM();
    v8::Isolate* isolate = CcTest::isolate();
    v8::HandleScope scope(isolate);
    Heap* heap = CcTest::heap();
    LocalContext context;
  
    v8::Persistent<Value> parent;
    v8::Persistent<Value> child;
  
    parent.Reset(isolate, v8::Object::New(isolate));
    child.Reset(isolate, v8::Object::New(isolate));
  
    heap::SimulateFullSpace(heap->old_space());
    heap->CollectGarbage(OLD_SPACE);
    {
      UniqueId id = MakeUniqueId(parent);
      isolate->SetObjectGroupId(parent, id);
      isolate->SetReferenceFromGroup(id, child);
    }
    // The CollectGarbage call above starts sweeper threads.
    // The crash will happen if the following two functions
    // are called before sweeping finishes.
    heap->StartIncrementalMarking();
    heap->FinalizeIncrementalMarkingIfComplete("test");
  }
  
  
  HEAP_TEST(TestMemoryReducerSampleJsCalls) {
    CcTest::InitializeVM();
    v8::HandleScope scope(CcTest::isolate());
    Heap* heap = CcTest::heap();
    Isolate* isolate = CcTest::i_isolate();
    MemoryReducer* memory_reducer = heap->memory_reducer_;
    memory_reducer->SampleAndGetJsCallsPerMs(0);
    isolate->IncrementJsCallsFromApiCounter();
    isolate->IncrementJsCallsFromApiCounter();
    isolate->IncrementJsCallsFromApiCounter();
    double calls_per_ms = memory_reducer->SampleAndGetJsCallsPerMs(1);
    CheckDoubleEquals(3, calls_per_ms);
  
    calls_per_ms = memory_reducer->SampleAndGetJsCallsPerMs(2);
    CheckDoubleEquals(0, calls_per_ms);
  
    isolate->IncrementJsCallsFromApiCounter();
    isolate->IncrementJsCallsFromApiCounter();
    isolate->IncrementJsCallsFromApiCounter();
    isolate->IncrementJsCallsFromApiCounter();
    calls_per_ms = memory_reducer->SampleAndGetJsCallsPerMs(4);
    CheckDoubleEquals(2, calls_per_ms);
  }
  
  HEAP_TEST(Regress587004) {
    FLAG_concurrent_sweeping = false;
  #ifdef VERIFY_HEAP
    FLAG_verify_heap = false;
  #endif
    CcTest::InitializeVM();
    v8::HandleScope scope(CcTest::isolate());
    Heap* heap = CcTest::heap();
    Isolate* isolate = CcTest::i_isolate();
    Factory* factory = isolate->factory();
    const int N = (Page::kMaxRegularHeapObjectSize - FixedArray::kHeaderSize) /
                  kPointerSize;
    Handle<FixedArray> array = factory->NewFixedArray(N, TENURED);
    CHECK(heap->old_space()->Contains(*array));
    Handle<Object> number = factory->NewHeapNumber(1.0);
    CHECK(heap->InNewSpace(*number));
    for (int i = 0; i < N; i++) {
      array->set(i, *number);
    }
    heap->CollectGarbage(OLD_SPACE);
    heap::SimulateFullSpace(heap->old_space());
    heap->RightTrimFixedArray<Heap::CONCURRENT_TO_SWEEPER>(*array, N - 1);
    heap->mark_compact_collector()->EnsureSweepingCompleted();
    ByteArray* byte_array;
    const int M = 256;
    // Don't allow old space expansion. The test works without this flag too,
    // but becomes very slow.
    heap->set_force_oom(true);
    while (heap->AllocateByteArray(M, TENURED).To(&byte_array)) {
      for (int j = 0; j < M; j++) {
        byte_array->set(j, 0x31);
      }
    }
    // Re-enable old space expansion to avoid OOM crash.
    heap->set_force_oom(false);
    heap->CollectGarbage(NEW_SPACE);
  }
  
  HEAP_TEST(Regress589413) {
    FLAG_stress_compaction = true;
    FLAG_manual_evacuation_candidates_selection = true;
    FLAG_parallel_compaction = false;
    FLAG_concurrent_sweeping = false;
    CcTest::InitializeVM();
    v8::HandleScope scope(CcTest::isolate());
    Heap* heap = CcTest::heap();
    // Get the heap in clean state.
    heap->CollectGarbage(OLD_SPACE);
    heap->CollectGarbage(OLD_SPACE);
    Isolate* isolate = CcTest::i_isolate();
    Factory* factory = isolate->factory();
    // Fill the new space with byte arrays with elements looking like pointers.
    const int M = 256;
    ByteArray* byte_array;
    while (heap->AllocateByteArray(M).To(&byte_array)) {
      for (int j = 0; j < M; j++) {
        byte_array->set(j, 0x31);
      }
      // Add the array in root set.
      handle(byte_array);
    }
    // Make sure the byte arrays will be promoted on the next GC.
    heap->CollectGarbage(NEW_SPACE);
    // This number is close to large free list category threshold.
    const int N = 0x3eee;
    {
      std::vector<FixedArray*> arrays;
      std::set<Page*> pages;
      FixedArray* array;
      // Fill all pages with fixed arrays.
      heap->set_force_oom(true);
      while (heap->AllocateFixedArray(N, TENURED).To(&array)) {
        arrays.push_back(array);
        pages.insert(Page::FromAddress(array->address()));
        // Add the array in root set.
        handle(array);
      }
      // Expand and full one complete page with fixed arrays.
      heap->set_force_oom(false);
      while (heap->AllocateFixedArray(N, TENURED).To(&array)) {
        arrays.push_back(array);
        pages.insert(Page::FromAddress(array->address()));
        // Add the array in root set.
        handle(array);
        // Do not expand anymore.
        heap->set_force_oom(true);
      }
      // Expand and mark the new page as evacuation candidate.
      heap->set_force_oom(false);
      {
        AlwaysAllocateScope always_allocate(isolate);
        Handle<HeapObject> ec_obj = factory->NewFixedArray(5000, TENURED);
        Page* ec_page = Page::FromAddress(ec_obj->address());
        ec_page->SetFlag(MemoryChunk::FORCE_EVACUATION_CANDIDATE_FOR_TESTING);
        // Make all arrays point to evacuation candidate so that
        // slots are recorded for them.
        for (size_t j = 0; j < arrays.size(); j++) {
          array = arrays[j];
          for (int i = 0; i < N; i++) {
            array->set(i, *ec_obj);
          }
        }
      }
      heap::SimulateIncrementalMarking(heap);
      for (size_t j = 0; j < arrays.size(); j++) {
        heap->RightTrimFixedArray<Heap::CONCURRENT_TO_SWEEPER>(arrays[j], N - 1);
      }
    }
    // Force allocation from the free list.
    heap->set_force_oom(true);
    heap->CollectGarbage(OLD_SPACE);
  }
  
  TEST(Regress598319) {
    // This test ensures that no white objects can cross the progress bar of large
    // objects during incremental marking. It checks this by using Shift() during
    // incremental marking.
    CcTest::InitializeVM();
    v8::HandleScope scope(CcTest::isolate());
    Heap* heap = CcTest::heap();
    Isolate* isolate = heap->isolate();
  
    const int kNumberOfObjects = Page::kMaxRegularHeapObjectSize / kPointerSize;
  
    struct Arr {
      Arr(Isolate* isolate, int number_of_objects) {
        root = isolate->factory()->NewFixedArray(1, TENURED);
        {
          // Temporary scope to avoid getting any other objects into the root set.
          v8::HandleScope scope(CcTest::isolate());
          Handle<FixedArray> tmp =
              isolate->factory()->NewFixedArray(number_of_objects);
          root->set(0, *tmp);
          for (int i = 0; i < get()->length(); i++) {
            tmp = isolate->factory()->NewFixedArray(100, TENURED);
            get()->set(i, *tmp);
          }
        }
      }
  
      FixedArray* get() { return FixedArray::cast(root->get(0)); }
  
      Handle<FixedArray> root;
    } arr(isolate, kNumberOfObjects);
  
    CHECK_EQ(arr.get()->length(), kNumberOfObjects);
    CHECK(heap->lo_space()->Contains(arr.get()));
    LargePage* page = heap->lo_space()->FindPage(arr.get()->address());
    CHECK_NOT_NULL(page);
  
    // GC to cleanup state
    heap->CollectGarbage(OLD_SPACE);
    MarkCompactCollector* collector = heap->mark_compact_collector();
    if (collector->sweeping_in_progress()) {
      collector->EnsureSweepingCompleted();
    }
  
    CHECK(heap->lo_space()->Contains(arr.get()));
    CHECK(Marking::IsWhite(ObjectMarking::MarkBitFrom(arr.get())));
    for (int i = 0; i < arr.get()->length(); i++) {
      CHECK(Marking::IsWhite(
          ObjectMarking::MarkBitFrom(HeapObject::cast(arr.get()->get(i)))));
    }
  
    // Start incremental marking.
    IncrementalMarking* marking = heap->incremental_marking();
    CHECK(marking->IsMarking() || marking->IsStopped());
    if (marking->IsStopped()) {
      heap->StartIncrementalMarking();
    }
    CHECK(marking->IsMarking());
  
    // Check that we have not marked the interesting array during root scanning.
    for (int i = 0; i < arr.get()->length(); i++) {
      CHECK(Marking::IsWhite(
          ObjectMarking::MarkBitFrom(HeapObject::cast(arr.get()->get(i)))));
    }
  
    // Now we search for a state where we are in incremental marking and have
    // only partially marked the large object.
    while (!marking->IsComplete()) {
      marking->Step(i::KB, i::IncrementalMarking::NO_GC_VIA_STACK_GUARD);
      if (page->IsFlagSet(Page::HAS_PROGRESS_BAR) && page->progress_bar() > 0) {
        CHECK_NE(page->progress_bar(), arr.get()->Size());
        {
          // Shift by 1, effectively moving one white object across the progress
          // bar, meaning that we will miss marking it.
          v8::HandleScope scope(CcTest::isolate());
          Handle<JSArray> js_array = isolate->factory()->NewJSArrayWithElements(
              Handle<FixedArray>(arr.get()));
          js_array->GetElementsAccessor()->Shift(js_array);
        }
        break;
      }
    }
  
    // Finish marking with bigger steps to speed up test.
    while (!marking->IsComplete()) {
      marking->Step(10 * i::MB, i::IncrementalMarking::NO_GC_VIA_STACK_GUARD);
      if (marking->IsReadyToOverApproximateWeakClosure()) {
        marking->FinalizeIncrementally();
      }
    }
    CHECK(marking->IsComplete());
  
    // All objects need to be black after marking. If a white object crossed the
    // progress bar, we would fail here.
    for (int i = 0; i < arr.get()->length(); i++) {
      CHECK(Marking::IsBlack(
          ObjectMarking::MarkBitFrom(HeapObject::cast(arr.get()->get(i)))));
    }
  }
  
  TEST(Regress609761) {
    CcTest::InitializeVM();
    v8::HandleScope scope(CcTest::isolate());
    Heap* heap = CcTest::heap();
    Isolate* isolate = heap->isolate();
  
    intptr_t size_before = heap->SizeOfObjects();
    Handle<FixedArray> array = isolate->factory()->NewFixedArray(200000);
    array->Shrink(1);
    intptr_t size_after = heap->SizeOfObjects();
    CHECK_EQ(size_after, size_before + array->Size());
  }
  
  TEST(Regress615489) {
    FLAG_black_allocation = true;
    CcTest::InitializeVM();
    v8::HandleScope scope(CcTest::isolate());
    Heap* heap = CcTest::heap();
    Isolate* isolate = heap->isolate();
    heap->CollectAllGarbage();
  
    i::MarkCompactCollector* collector = heap->mark_compact_collector();
    i::IncrementalMarking* marking = heap->incremental_marking();
    if (collector->sweeping_in_progress()) {
      collector->EnsureSweepingCompleted();
    }
    CHECK(marking->IsMarking() || marking->IsStopped());
    if (marking->IsStopped()) {
      heap->StartIncrementalMarking();
    }
    CHECK(marking->IsMarking());
    marking->StartBlackAllocationForTesting();
    {
      AlwaysAllocateScope always_allocate(CcTest::i_isolate());
      v8::HandleScope inner(CcTest::isolate());
      isolate->factory()->NewFixedArray(500, TENURED)->Size();
    }
    while (!marking->IsComplete()) {
      marking->Step(i::MB, i::IncrementalMarking::NO_GC_VIA_STACK_GUARD);
      if (marking->IsReadyToOverApproximateWeakClosure()) {
        marking->FinalizeIncrementally();
      }
    }
    CHECK(marking->IsComplete());
    intptr_t size_before = heap->SizeOfObjects();
    CcTest::heap()->CollectAllGarbage();
    intptr_t size_after = heap->SizeOfObjects();
    // Live size does not increase after garbage collection.
    CHECK_LE(size_after, size_before);
  }
  
  TEST(LeftTrimFixedArrayInBlackArea) {
    FLAG_black_allocation = true;
    CcTest::InitializeVM();
    v8::HandleScope scope(CcTest::isolate());
    Heap* heap = CcTest::heap();
    Isolate* isolate = heap->isolate();
    heap->CollectAllGarbage();
  
    i::MarkCompactCollector* collector = heap->mark_compact_collector();
    i::IncrementalMarking* marking = heap->incremental_marking();
    if (collector->sweeping_in_progress()) {
      collector->EnsureSweepingCompleted();
    }
    CHECK(marking->IsMarking() || marking->IsStopped());
    if (marking->IsStopped()) {
      heap->StartIncrementalMarking();
    }
    CHECK(marking->IsMarking());
    marking->StartBlackAllocationForTesting();
  
    // Ensure that we allocate a new page, set up a bump pointer area, and
    // perform the allocation in a black area.
    heap::SimulateFullSpace(heap->old_space());
    isolate->factory()->NewFixedArray(4, TENURED);
    Handle<FixedArray> array = isolate->factory()->NewFixedArray(50, TENURED);
    CHECK(heap->old_space()->Contains(*array));
    CHECK(Marking::IsBlack(ObjectMarking::MarkBitFrom(*array)));
  
    // Now left trim the allocated black area. A filler has to be installed
    // for the trimmed area and all mark bits of the trimmed area have to be
    // cleared.
    FixedArrayBase* trimmed = heap->LeftTrimFixedArray(*array, 10);
    CHECK(Marking::IsBlack(ObjectMarking::MarkBitFrom(trimmed)));
  
    heap::GcAndSweep(heap, OLD_SPACE);
  }
  
  TEST(ContinuousLeftTrimFixedArrayInBlackArea) {
    FLAG_black_allocation = true;
    CcTest::InitializeVM();
    v8::HandleScope scope(CcTest::isolate());
    Heap* heap = CcTest::heap();
    Isolate* isolate = heap->isolate();
    heap->CollectAllGarbage();
  
    i::MarkCompactCollector* collector = heap->mark_compact_collector();
    i::IncrementalMarking* marking = heap->incremental_marking();
    if (collector->sweeping_in_progress()) {
      collector->EnsureSweepingCompleted();
    }
    CHECK(marking->IsMarking() || marking->IsStopped());
    if (marking->IsStopped()) {
      heap->StartIncrementalMarking();
    }
    CHECK(marking->IsMarking());
    marking->StartBlackAllocationForTesting();
  
    // Ensure that we allocate a new page, set up a bump pointer area, and
    // perform the allocation in a black area.
    heap::SimulateFullSpace(heap->old_space());
    isolate->factory()->NewFixedArray(10, TENURED);
  
    // Allocate the fixed array that will be trimmed later.
    Handle<FixedArray> array = isolate->factory()->NewFixedArray(100, TENURED);
    Address start_address = array->address();
    Address end_address = start_address + array->Size();
    Page* page = Page::FromAddress(start_address);
    CHECK(Marking::IsBlack(ObjectMarking::MarkBitFrom(*array)));
    CHECK(page->markbits()->AllBitsSetInRange(
        page->AddressToMarkbitIndex(start_address),
        page->AddressToMarkbitIndex(end_address)));
    CHECK(heap->old_space()->Contains(*array));
  
    FixedArrayBase* previous = *array;
    FixedArrayBase* trimmed;
  
    // First trim in one word steps.
    for (int i = 0; i < 10; i++) {
      trimmed = heap->LeftTrimFixedArray(previous, 1);
      HeapObject* filler = HeapObject::FromAddress(previous->address());
      CHECK(filler->IsFiller());
      CHECK(Marking::IsBlack(ObjectMarking::MarkBitFrom(trimmed)));
      CHECK(Marking::IsImpossible(ObjectMarking::MarkBitFrom(previous)));
      previous = trimmed;
    }
  
    // Then trim in two and three word steps.
    for (int i = 2; i <= 3; i++) {
      for (int j = 0; j < 10; j++) {
        trimmed = heap->LeftTrimFixedArray(previous, i);
        HeapObject* filler = HeapObject::FromAddress(previous->address());
        CHECK(filler->IsFiller());
        CHECK(Marking::IsBlack(ObjectMarking::MarkBitFrom(trimmed)));
        CHECK(Marking::IsWhite(ObjectMarking::MarkBitFrom(previous)));
        previous = trimmed;
      }
    }
  
    heap::GcAndSweep(heap, OLD_SPACE);
  }
  
  TEST(ContinuousRightTrimFixedArrayInBlackArea) {
    FLAG_black_allocation = true;
    CcTest::InitializeVM();
    v8::HandleScope scope(CcTest::isolate());
    Heap* heap = CcTest::heap();
    Isolate* isolate = heap->isolate();
    heap->CollectAllGarbage();
  
    i::MarkCompactCollector* collector = heap->mark_compact_collector();
    i::IncrementalMarking* marking = heap->incremental_marking();
    if (collector->sweeping_in_progress()) {
      collector->EnsureSweepingCompleted();
    }
    CHECK(marking->IsMarking() || marking->IsStopped());
    if (marking->IsStopped()) {
      heap->StartIncrementalMarking();
    }
    CHECK(marking->IsMarking());
    marking->StartBlackAllocationForTesting();
  
    // Ensure that we allocate a new page, set up a bump pointer area, and
    // perform the allocation in a black area.
    heap::SimulateFullSpace(heap->old_space());
    isolate->factory()->NewFixedArray(10, TENURED);
  
    // Allocate the fixed array that will be trimmed later.
    Handle<FixedArray> array = isolate->factory()->NewFixedArray(100, TENURED);
    Address start_address = array->address();
    Address end_address = start_address + array->Size();
    Page* page = Page::FromAddress(start_address);
    CHECK(Marking::IsBlack(ObjectMarking::MarkBitFrom(*array)));
    CHECK(page->markbits()->AllBitsSetInRange(
        page->AddressToMarkbitIndex(start_address),
        page->AddressToMarkbitIndex(end_address)));
    CHECK(heap->old_space()->Contains(*array));
  
    // Trim it once by one word to make checking for white marking color uniform.
    Address previous = end_address - kPointerSize;
    heap->RightTrimFixedArray<Heap::SEQUENTIAL_TO_SWEEPER>(*array, 1);
    HeapObject* filler = HeapObject::FromAddress(previous);
    CHECK(filler->IsFiller());
    CHECK(Marking::IsImpossible(ObjectMarking::MarkBitFrom(previous)));
  
    // Trim 10 times by one, two, and three word.
    for (int i = 1; i <= 3; i++) {
      for (int j = 0; j < 10; j++) {
        previous -= kPointerSize * i;
        heap->RightTrimFixedArray<Heap::SEQUENTIAL_TO_SWEEPER>(*array, i);
        HeapObject* filler = HeapObject::FromAddress(previous);
        CHECK(filler->IsFiller());
        CHECK(Marking::IsWhite(ObjectMarking::MarkBitFrom(previous)));
      }
    }
  
    heap::GcAndSweep(heap, OLD_SPACE);
  }
  
  TEST(Regress618958) {
    CcTest::InitializeVM();
    v8::HandleScope scope(CcTest::isolate());
    Heap* heap = CcTest::heap();
    bool isolate_is_locked = true;
    heap->update_external_memory(100 * MB);
    int mark_sweep_count_before = heap->ms_count();
    heap->MemoryPressureNotification(MemoryPressureLevel::kCritical,
                                     isolate_is_locked);
    int mark_sweep_count_after = heap->ms_count();
    int mark_sweeps_performed = mark_sweep_count_after - mark_sweep_count_before;
    // The memory pressuer handler either performed two GCs or performed one and
    // started incremental marking.
    CHECK(mark_sweeps_performed == 2 ||
          (mark_sweeps_performed == 1 &&
           !heap->incremental_marking()->IsStopped()));
  }
  
  TEST(UncommitUnusedLargeObjectMemory) {
    CcTest::InitializeVM();
    v8::HandleScope scope(CcTest::isolate());
    Heap* heap = CcTest::heap();
    Isolate* isolate = heap->isolate();
  
    Handle<FixedArray> array = isolate->factory()->NewFixedArray(200000);
    MemoryChunk* chunk = MemoryChunk::FromAddress(array->address());
    CHECK(chunk->owner()->identity() == LO_SPACE);
  
    intptr_t size_before = array->Size();
    size_t committed_memory_before = chunk->CommittedPhysicalMemory();
  
    array->Shrink(1);
    CHECK(array->Size() < size_before);
  
    CcTest::heap()->CollectAllGarbage();
    CHECK(chunk->CommittedPhysicalMemory() < committed_memory_before);
    size_t shrinked_size =
        RoundUp((array->address() - chunk->address()) + array->Size(),
                base::OS::CommitPageSize());
    CHECK_EQ(shrinked_size, chunk->CommittedPhysicalMemory());
  }
  
  TEST(RememberedSetRemoveRange) {
    CcTest::InitializeVM();
    v8::HandleScope scope(CcTest::isolate());
    Heap* heap = CcTest::heap();
    Isolate* isolate = heap->isolate();
  
    Handle<FixedArray> array = isolate->factory()->NewFixedArray(Page::kPageSize /
                                                                kPointerSize);
    MemoryChunk* chunk = MemoryChunk::FromAddress(array->address());
    CHECK(chunk->owner()->identity() == LO_SPACE);
    Address start = array->address();
    // Maps slot to boolean indicator of whether the slot should be in the set.
    std::map<Address, bool> slots;
    slots[start + 0] = true;
    slots[start + kPointerSize] = true;
    slots[start + Page::kPageSize - kPointerSize] = true;
    slots[start + Page::kPageSize] = true;
    slots[start + Page::kPageSize + kPointerSize] = true;
    slots[chunk->area_end() - kPointerSize] = true;
  
    for (auto x : slots) {
      RememberedSet<OLD_TO_NEW>::Insert(chunk, x.first);
    }
  
    RememberedSet<OLD_TO_NEW>::Iterate(chunk, [&slots](Address addr) {
      CHECK(slots[addr]);
      return KEEP_SLOT;
    });
  
    RememberedSet<OLD_TO_NEW>::RemoveRange(chunk, start, start + kPointerSize);
    slots[start] = false;
    RememberedSet<OLD_TO_NEW>::Iterate(chunk, [&slots](Address addr) {
      CHECK(slots[addr]);
      return KEEP_SLOT;
    });
  
    RememberedSet<OLD_TO_NEW>::RemoveRange(chunk, start + kPointerSize,
                                           start + Page::kPageSize);
    slots[start + kPointerSize] = false;
    slots[start + Page::kPageSize - kPointerSize] = false;
    RememberedSet<OLD_TO_NEW>::Iterate(chunk, [&slots](Address addr) {
      CHECK(slots[addr]);
      return KEEP_SLOT;
    });
  
    RememberedSet<OLD_TO_NEW>::RemoveRange(
        chunk, start, start + Page::kPageSize + kPointerSize);
    slots[start + Page::kPageSize] = false;
    RememberedSet<OLD_TO_NEW>::Iterate(chunk, [&slots](Address addr) {
      CHECK(slots[addr]);
      return KEEP_SLOT;
    });
  
    RememberedSet<OLD_TO_NEW>::RemoveRange(
        chunk, chunk->area_end() - kPointerSize, chunk->area_end());
    slots[chunk->area_end() - kPointerSize] = false;
    RememberedSet<OLD_TO_NEW>::Iterate(chunk, [&slots](Address addr) {
      CHECK(slots[addr]);
      return KEEP_SLOT;
    });
  }
  
  }  // namespace internal
  }  // namespace v8
  