text: // Copyright 2012 the V8 project authors. All rights reserved.
  // Use of this source code is governed by a BSD-style license that can be
  // found in the LICENSE file.
  
  #ifndef V8_HEAP_HEAP_INL_H_
  #define V8_HEAP_HEAP_INL_H_
  
  #include <cmath>
  
  #include "src/base/platform/platform.h"
  #include "src/heap/heap.h"
  #include "src/heap/store-buffer.h"
  #include "src/heap/store-buffer-inl.h"
  #include "src/heap-profiler.h"
  #include "src/isolate.h"
  #include "src/list-inl.h"
  #include "src/msan.h"
  #include "src/objects.h"
  
  namespace v8 {
  namespace internal {
  
  void PromotionQueue::insert(HeapObject* target, int size) {
    if (emergency_stack_ != NULL) {
      emergency_stack_->Add(Entry(target, size));
      return;
    }
  
    if ((rear_ - 2) < limit_) {
      RelocateQueueHead();
      emergency_stack_->Add(Entry(target, size));
      return;
    }
  
    *(--rear_) = reinterpret_cast<intptr_t>(target);
    *(--rear_) = size;
  // Assert no overflow into live objects.
  #ifdef DEBUG
    SemiSpace::AssertValidRange(target->GetIsolate()->heap()->new_space()->top(),
                                reinterpret_cast<Address>(rear_));
  #endif
  }
  
  
  template <>
  bool inline Heap::IsOneByte(Vector<const char> str, int chars) {
    // TODO(dcarney): incorporate Latin-1 check when Latin-1 is supported?
    return chars == str.length();
  }
  
  
  template <>
  bool inline Heap::IsOneByte(String* str, int chars) {
    return str->IsOneByteRepresentation();
  }
  
  
  AllocationResult Heap::AllocateInternalizedStringFromUtf8(
      Vector<const char> str, int chars, uint32_t hash_field) {
    if (IsOneByte(str, chars)) {
      return AllocateOneByteInternalizedString(Vector<const uint8_t>::cast(str),
                                               hash_field);
    }
    return AllocateInternalizedStringImpl<false>(str, chars, hash_field);
  }
  
  
  template <typename T>
  AllocationResult Heap::AllocateInternalizedStringImpl(T t, int chars,
                                                        uint32_t hash_field) {
    if (IsOneByte(t, chars)) {
      return AllocateInternalizedStringImpl<true>(t, chars, hash_field);
    }
    return AllocateInternalizedStringImpl<false>(t, chars, hash_field);
  }
  
  
  AllocationResult Heap::AllocateOneByteInternalizedString(
      Vector<const uint8_t> str, uint32_t hash_field) {
    CHECK_GE(String::kMaxLength, str.length());
    // Compute map and object size.
    Map* map = one_byte_internalized_string_map();
    int size = SeqOneByteString::SizeFor(str.length());
    AllocationSpace space = SelectSpace(size, TENURED);
  
    // Allocate string.
    HeapObject* result;
    {
      AllocationResult allocation = AllocateRaw(size, space, OLD_SPACE);
      if (!allocation.To(&result)) return allocation;
    }
  
    // String maps are all immortal immovable objects.
    result->set_map_no_write_barrier(map);
    // Set length and hash fields of the allocated string.
    String* answer = String::cast(result);
    answer->set_length(str.length());
    answer->set_hash_field(hash_field);
  
    DCHECK_EQ(size, answer->Size());
  
    // Fill in the characters.
    MemCopy(answer->address() + SeqOneByteString::kHeaderSize, str.start(),
            str.length());
  
    return answer;
  }
  
  
  AllocationResult Heap::AllocateTwoByteInternalizedString(Vector<const uc16> str,
                                                           uint32_t hash_field) {
    CHECK_GE(String::kMaxLength, str.length());
    // Compute map and object size.
    Map* map = internalized_string_map();
    int size = SeqTwoByteString::SizeFor(str.length());
    AllocationSpace space = SelectSpace(size, TENURED);
  
    // Allocate string.
    HeapObject* result;
    {
      AllocationResult allocation = AllocateRaw(size, space, OLD_SPACE);
      if (!allocation.To(&result)) return allocation;
    }
  
    result->set_map(map);
    // Set length and hash fields of the allocated string.
    String* answer = String::cast(result);
    answer->set_length(str.length());
    answer->set_hash_field(hash_field);
  
    DCHECK_EQ(size, answer->Size());
  
    // Fill in the characters.
    MemCopy(answer->address() + SeqTwoByteString::kHeaderSize, str.start(),
            str.length() * kUC16Size);
  
    return answer;
  }
  
  AllocationResult Heap::CopyFixedArray(FixedArray* src) {
    if (src->length() == 0) return src;
    return CopyFixedArrayWithMap(src, src->map());
  }
  
  
  AllocationResult Heap::CopyFixedDoubleArray(FixedDoubleArray* src) {
    if (src->length() == 0) return src;
    return CopyFixedDoubleArrayWithMap(src, src->map());
  }
  
  
  AllocationResult Heap::CopyConstantPoolArray(ConstantPoolArray* src) {
    if (src->length() == 0) return src;
    return CopyConstantPoolArrayWithMap(src, src->map());
  }
  
  
  AllocationResult Heap::AllocateRaw(int size_in_bytes, AllocationSpace space,
                                     AllocationSpace retry_space,
                                     AllocationAlignment alignment) {
    DCHECK(AllowHandleAllocation::IsAllowed());
    DCHECK(AllowHeapAllocation::IsAllowed());
    DCHECK(gc_state_ == NOT_IN_GC);
  #ifdef DEBUG
    if (FLAG_gc_interval >= 0 && AllowAllocationFailure::IsAllowed(isolate_) &&
        Heap::allocation_timeout_-- <= 0) {
      return AllocationResult::Retry(space);
    }
    isolate_->counters()->objs_since_last_full()->Increment();
    isolate_->counters()->objs_since_last_young()->Increment();
  #endif
  
    HeapObject* object;
    AllocationResult allocation;
    if (NEW_SPACE == space) {
      allocation = new_space_.AllocateRaw(size_in_bytes, alignment);
      if (always_allocate() && allocation.IsRetry() && retry_space != NEW_SPACE) {
        space = retry_space;
      } else {
        if (allocation.To(&object)) {
          OnAllocationEvent(object, size_in_bytes);
        }
        return allocation;
      }
    }
  
    if (OLD_SPACE == space) {
      allocation = old_space_->AllocateRaw(size_in_bytes, alignment);
    } else if (CODE_SPACE == space) {
      if (size_in_bytes <= code_space()->AreaSize()) {
        allocation = code_space_->AllocateRawUnaligned(size_in_bytes);
      } else {
        // Large code objects are allocated in large object space.
        allocation = lo_space_->AllocateRaw(size_in_bytes, EXECUTABLE);
      }
    } else if (LO_SPACE == space) {
      allocation = lo_space_->AllocateRaw(size_in_bytes, NOT_EXECUTABLE);
    } else {
      DCHECK(MAP_SPACE == space);
      allocation = map_space_->AllocateRawUnaligned(size_in_bytes);
    }
    if (allocation.To(&object)) {
      OnAllocationEvent(object, size_in_bytes);
    } else {
      old_gen_exhausted_ = true;
    }
    return allocation;
  }
  
  
  void Heap::OnAllocationEvent(HeapObject* object, int size_in_bytes) {
    HeapProfiler* profiler = isolate_->heap_profiler();
    if (profiler->is_tracking_allocations()) {
      profiler->AllocationEvent(object->address(), size_in_bytes);
    }
  
    ++allocations_count_;
  
    if (FLAG_verify_predictable) {
      UpdateAllocationsHash(object);
      UpdateAllocationsHash(size_in_bytes);
  
      if ((FLAG_dump_allocations_digest_at_alloc > 0) &&
          (--dump_allocations_hash_countdown_ == 0)) {
        dump_allocations_hash_countdown_ = FLAG_dump_allocations_digest_at_alloc;
        PrintAlloctionsHash();
      }
    }
  
    if (FLAG_trace_allocation_stack_interval > 0) {
      if (allocations_count_ % FLAG_trace_allocation_stack_interval == 0) {
        isolate()->PrintStack(stdout, Isolate::kPrintStackConcise);
      }
    }
  }
  
  
  void Heap::OnMoveEvent(HeapObject* target, HeapObject* source,
                         int size_in_bytes) {
    HeapProfiler* heap_profiler = isolate_->heap_profiler();
    if (heap_profiler->is_tracking_object_moves()) {
      heap_profiler->ObjectMoveEvent(source->address(), target->address(),
                                     size_in_bytes);
    }
    if (target->IsSharedFunctionInfo()) {
      LOG_CODE_EVENT(isolate_, SharedFunctionInfoMoveEvent(source->address(),
                                                           target->address()));
    }
  
    if (FLAG_verify_predictable) {
      ++allocations_count_;
  
      UpdateAllocationsHash(source);
      UpdateAllocationsHash(target);
      UpdateAllocationsHash(size_in_bytes);
  
      if ((FLAG_dump_allocations_digest_at_alloc > 0) &&
          (--dump_allocations_hash_countdown_ == 0)) {
        dump_allocations_hash_countdown_ = FLAG_dump_allocations_digest_at_alloc;
        PrintAlloctionsHash();
      }
    }
  }
  
  
  void Heap::UpdateAllocationsHash(HeapObject* object) {
    Address object_address = object->address();
    MemoryChunk* memory_chunk = MemoryChunk::FromAddress(object_address);
    AllocationSpace allocation_space = memory_chunk->owner()->identity();
  
    STATIC_ASSERT(kSpaceTagSize + kPageSizeBits <= 32);
    uint32_t value =
        static_cast<uint32_t>(object_address - memory_chunk->address()) |
        (static_cast<uint32_t>(allocation_space) << kPageSizeBits);
  
    UpdateAllocationsHash(value);
  }
  
  
  void Heap::UpdateAllocationsHash(uint32_t value) {
    uint16_t c1 = static_cast<uint16_t>(value);
    uint16_t c2 = static_cast<uint16_t>(value >> 16);
    raw_allocations_hash_ =
        StringHasher::AddCharacterCore(raw_allocations_hash_, c1);
    raw_allocations_hash_ =
        StringHasher::AddCharacterCore(raw_allocations_hash_, c2);
  }
  
  
  void Heap::PrintAlloctionsHash() {
    uint32_t hash = StringHasher::GetHashCore(raw_allocations_hash_);
    PrintF("\n### Allocations = %u, hash = 0x%08x\n", allocations_count_, hash);
  }
  
  
  void Heap::FinalizeExternalString(String* string) {
    DCHECK(string->IsExternalString());
    v8::String::ExternalStringResourceBase** resource_addr =
        reinterpret_cast<v8::String::ExternalStringResourceBase**>(
            reinterpret_cast<byte*>(string) + ExternalString::kResourceOffset -
            kHeapObjectTag);
  
    // Dispose of the C++ object if it has not already been disposed.
    if (*resource_addr != NULL) {
      (*resource_addr)->Dispose();
      *resource_addr = NULL;
    }
  }
  
  
  bool Heap::InNewSpace(Object* object) {
    bool result = new_space_.Contains(object);
    DCHECK(!result ||                 // Either not in new space
           gc_state_ != NOT_IN_GC ||  // ... or in the middle of GC
           InToSpace(object));        // ... or in to-space (where we allocate).
    return result;
  }
  
  
  bool Heap::InNewSpace(Address address) { return new_space_.Contains(address); }
  
  
  bool Heap::InFromSpace(Object* object) {
    return new_space_.FromSpaceContains(object);
  }
  
  
  bool Heap::InToSpace(Object* object) {
    return new_space_.ToSpaceContains(object);
  }
  
  
  bool Heap::InOldSpace(Address address) { return old_space_->Contains(address); }
  
  
  bool Heap::InOldSpace(Object* object) {
    return InOldSpace(reinterpret_cast<Address>(object));
  }
  
  
  bool Heap::OldGenerationAllocationLimitReached() {
    if (!incremental_marking()->IsStopped()) return false;
    return OldGenerationSpaceAvailable() < 0;
  }
  
  
  bool Heap::ShouldBePromoted(Address old_address, int object_size) {
    NewSpacePage* page = NewSpacePage::FromAddress(old_address);
    Address age_mark = new_space_.age_mark();
    return page->IsFlagSet(MemoryChunk::NEW_SPACE_BELOW_AGE_MARK) &&
           (!page->ContainsLimit(age_mark) || old_address < age_mark);
  }
  
  
  void Heap::RecordWrite(Address address, int offset) {
    if (!InNewSpace(address)) store_buffer_.Mark(address + offset);
  }
  
  
  void Heap::RecordWrites(Address address, int start, int len) {
    if (!InNewSpace(address)) {
      for (int i = 0; i < len; i++) {
        store_buffer_.Mark(address + start + i * kPointerSize);
      }
    }
  }
  
  
  bool Heap::AllowedToBeMigrated(HeapObject* obj, AllocationSpace dst) {
    // Object migration is governed by the following rules:
    //
    // 1) Objects in new-space can be migrated to the old space
    //    that matches their target space or they stay in new-space.
    // 2) Objects in old-space stay in the same space when migrating.
    // 3) Fillers (two or more words) can migrate due to left-trimming of
    //    fixed arrays in new-space or old space.
    // 4) Fillers (one word) can never migrate, they are skipped by
    //    incremental marking explicitly to prevent invalid pattern.
    //
    // Since this function is used for debugging only, we do not place
    // asserts here, but check everything explicitly.
    if (obj->map() == one_pointer_filler_map()) return false;
    InstanceType type = obj->map()->instance_type();
    MemoryChunk* chunk = MemoryChunk::FromAddress(obj->address());
    AllocationSpace src = chunk->owner()->identity();
    switch (src) {
      case NEW_SPACE:
        return dst == src || dst == OLD_SPACE;
      case OLD_SPACE:
        return dst == src &&
               (dst == OLD_SPACE || obj->IsFiller() || obj->IsExternalString());
      case CODE_SPACE:
        return dst == src && type == CODE_TYPE;
      case MAP_SPACE:
      case LO_SPACE:
        return false;
    }
    UNREACHABLE();
    return false;
  }
  
  
  void Heap::CopyBlock(Address dst, Address src, int byte_size) {
    CopyWords(reinterpret_cast<Object**>(dst), reinterpret_cast<Object**>(src),
              static_cast<size_t>(byte_size / kPointerSize));
  }
  
  
  void Heap::MoveBlock(Address dst, Address src, int byte_size) {
    DCHECK(IsAligned(byte_size, kPointerSize));
  
    int size_in_words = byte_size / kPointerSize;
  
    if ((dst < src) || (dst >= (src + byte_size))) {
      Object** src_slot = reinterpret_cast<Object**>(src);
      Object** dst_slot = reinterpret_cast<Object**>(dst);
      Object** end_slot = src_slot + size_in_words;
  
      while (src_slot != end_slot) {
        *dst_slot++ = *src_slot++;
      }
    } else {
      MemMove(dst, src, static_cast<size_t>(byte_size));
    }
  }
  
  
  void Heap::ScavengePointer(HeapObject** p) { ScavengeObject(p, *p); }
  
  
  AllocationMemento* Heap::FindAllocationMemento(HeapObject* object) {
    // Check if there is potentially a memento behind the object. If
    // the last word of the memento is on another page we return
    // immediately.
    Address object_address = object->address();
    Address memento_address = object_address + object->Size();
    Address last_memento_word_address = memento_address + kPointerSize;
    if (!NewSpacePage::OnSamePage(object_address, last_memento_word_address)) {
      return NULL;
    }
  
    HeapObject* candidate = HeapObject::FromAddress(memento_address);
    Map* candidate_map = candidate->map();
    // This fast check may peek at an uninitialized word. However, the slow check
    // below (memento_address == top) ensures that this is safe. Mark the word as
    // initialized to silence MemorySanitizer warnings.
    MSAN_MEMORY_IS_INITIALIZED(&candidate_map, sizeof(candidate_map));
    if (candidate_map != allocation_memento_map()) return NULL;
  
    // Either the object is the last object in the new space, or there is another
    // object of at least word size (the header map word) following it, so
    // suffices to compare ptr and top here. Note that technically we do not have
    // to compare with the current top pointer of the from space page during GC,
    // since we always install filler objects above the top pointer of a from
    // space page when performing a garbage collection. However, always performing
    // the test makes it possible to have a single, unified version of
    // FindAllocationMemento that is used both by the GC and the mutator.
    Address top = NewSpaceTop();
    DCHECK(memento_address == top ||
           memento_address + HeapObject::kHeaderSize <= top ||
           !NewSpacePage::OnSamePage(memento_address, top));
    if (memento_address == top) return NULL;
  
    AllocationMemento* memento = AllocationMemento::cast(candidate);
    if (!memento->IsValid()) return NULL;
    return memento;
  }
  
  
  void Heap::UpdateAllocationSiteFeedback(HeapObject* object,
                                          ScratchpadSlotMode mode) {
    Heap* heap = object->GetHeap();
    DCHECK(heap->InFromSpace(object));
  
    if (!FLAG_allocation_site_pretenuring ||
        !AllocationSite::CanTrack(object->map()->instance_type()))
      return;
  
    AllocationMemento* memento = heap->FindAllocationMemento(object);
    if (memento == NULL) return;
  
    if (memento->GetAllocationSite()->IncrementMementoFoundCount()) {
      heap->AddAllocationSiteToScratchpad(memento->GetAllocationSite(), mode);
    }
  }
  
  
  void Heap::ScavengeObject(HeapObject** p, HeapObject* object) {
    DCHECK(object->GetIsolate()->heap()->InFromSpace(object));
  
    // We use the first word (where the map pointer usually is) of a heap
    // object to record the forwarding pointer.  A forwarding pointer can
    // point to an old space, the code space, or the to space of the new
    // generation.
    MapWord first_word = object->map_word();
  
    // If the first word is a forwarding address, the object has already been
    // copied.
    if (first_word.IsForwardingAddress()) {
      HeapObject* dest = first_word.ToForwardingAddress();
      DCHECK(object->GetIsolate()->heap()->InFromSpace(*p));
      *p = dest;
      return;
    }
  
    UpdateAllocationSiteFeedback(object, IGNORE_SCRATCHPAD_SLOT);
  
    // AllocationMementos are unrooted and shouldn't survive a scavenge
    DCHECK(object->map() != object->GetHeap()->allocation_memento_map());
    // Call the slow part of scavenge object.
    return ScavengeObjectSlow(p, object);
  }
  
  
  bool Heap::CollectGarbage(AllocationSpace space, const char* gc_reason,
                            const v8::GCCallbackFlags callbackFlags) {
    const char* collector_reason = NULL;
    GarbageCollector collector = SelectGarbageCollector(space, &collector_reason);
    return CollectGarbage(collector, gc_reason, collector_reason, callbackFlags);
  }
  
  
  Isolate* Heap::isolate() {
    return reinterpret_cast<Isolate*>(
        reinterpret_cast<intptr_t>(this) -
        reinterpret_cast<size_t>(reinterpret_cast<Isolate*>(16)->heap()) + 16);
  }
  
  
  // Calls the FUNCTION_CALL function and retries it up to three times
  // to guarantee that any allocations performed during the call will
  // succeed if there's enough memory.
  
  // Warning: Do not use the identifiers __object__, __maybe_object__ or
  // __scope__ in a call to this macro.
  
  #define RETURN_OBJECT_UNLESS_RETRY(ISOLATE, RETURN_VALUE) \
    if (__allocation__.To(&__object__)) {                   \
      DCHECK(__object__ != (ISOLATE)->heap()->exception()); \
      RETURN_VALUE;                                         \
    }
  
  #define CALL_AND_RETRY(ISOLATE, FUNCTION_CALL, RETURN_VALUE, RETURN_EMPTY)    \
    do {                                                                        \
      AllocationResult __allocation__ = FUNCTION_CALL;                          \
      Object* __object__ = NULL;                                                \
      RETURN_OBJECT_UNLESS_RETRY(ISOLATE, RETURN_VALUE)                         \
      /* Two GCs before panicking.  In newspace will almost always succeed. */  \
      for (int __i__ = 0; __i__ < 2; __i__++) {                                 \
        (ISOLATE)->heap()->CollectGarbage(__allocation__.RetrySpace(),          \
                                          "allocation failure");                \
        __allocation__ = FUNCTION_CALL;                                         \
        RETURN_OBJECT_UNLESS_RETRY(ISOLATE, RETURN_VALUE)                       \
      }                                                                         \
      (ISOLATE)->counters()->gc_last_resort_from_handles()->Increment();        \
      (ISOLATE)->heap()->CollectAllAvailableGarbage("last resort gc");          \
      {                                                                         \
        AlwaysAllocateScope __scope__(ISOLATE);                                 \
        __allocation__ = FUNCTION_CALL;                                         \
      }                                                                         \
      RETURN_OBJECT_UNLESS_RETRY(ISOLATE, RETURN_VALUE)                         \
      /* TODO(1181417): Fix this. */                                            \
      v8::internal::Heap::FatalProcessOutOfMemory("CALL_AND_RETRY_LAST", true); \
      RETURN_EMPTY;                                                             \
    } while (false)
  
  #define CALL_AND_RETRY_OR_DIE(ISOLATE, FUNCTION_CALL, RETURN_VALUE, \
                                RETURN_EMPTY)                         \
    CALL_AND_RETRY(ISOLATE, FUNCTION_CALL, RETURN_VALUE, RETURN_EMPTY)
  
  #define CALL_HEAP_FUNCTION(ISOLATE, FUNCTION_CALL, TYPE)                      \
    CALL_AND_RETRY_OR_DIE(ISOLATE, FUNCTION_CALL,                               \
                          return Handle<TYPE>(TYPE::cast(__object__), ISOLATE), \
                          return Handle<TYPE>())
  
  
  #define CALL_HEAP_FUNCTION_VOID(ISOLATE, FUNCTION_CALL) \
    CALL_AND_RETRY_OR_DIE(ISOLATE, FUNCTION_CALL, return, return)
  
  
  void ExternalStringTable::AddString(String* string) {
    DCHECK(string->IsExternalString());
    if (heap_->InNewSpace(string)) {
      new_space_strings_.Add(string);
    } else {
      old_space_strings_.Add(string);
    }
  }
  
  
  void ExternalStringTable::Iterate(ObjectVisitor* v) {
    if (!new_space_strings_.is_empty()) {
      Object** start = &new_space_strings_[0];
      v->VisitPointers(start, start + new_space_strings_.length());
    }
    if (!old_space_strings_.is_empty()) {
      Object** start = &old_space_strings_[0];
      v->VisitPointers(start, start + old_space_strings_.length());
    }
  }
  
  
  // Verify() is inline to avoid ifdef-s around its calls in release
  // mode.
  void ExternalStringTable::Verify() {
  #ifdef DEBUG
    for (int i = 0; i < new_space_strings_.length(); ++i) {
      Object* obj = Object::cast(new_space_strings_[i]);
      DCHECK(heap_->InNewSpace(obj));
      DCHECK(obj != heap_->the_hole_value());
    }
    for (int i = 0; i < old_space_strings_.length(); ++i) {
      Object* obj = Object::cast(old_space_strings_[i]);
      DCHECK(!heap_->InNewSpace(obj));
      DCHECK(obj != heap_->the_hole_value());
    }
  #endif
  }
  
  
  void ExternalStringTable::AddOldString(String* string) {
    DCHECK(string->IsExternalString());
    DCHECK(!heap_->InNewSpace(string));
    old_space_strings_.Add(string);
  }
  
  
  void ExternalStringTable::ShrinkNewStrings(int position) {
    new_space_strings_.Rewind(position);
  #ifdef VERIFY_HEAP
    if (FLAG_verify_heap) {
      Verify();
    }
  #endif
  }
  
  
  void Heap::ClearInstanceofCache() {
    set_instanceof_cache_function(Smi::FromInt(0));
  }
  
  
  Object* Heap::ToBoolean(bool condition) {
    return condition ? true_value() : false_value();
  }
  
  
  void Heap::CompletelyClearInstanceofCache() {
    set_instanceof_cache_map(Smi::FromInt(0));
    set_instanceof_cache_function(Smi::FromInt(0));
  }
  
  
  AlwaysAllocateScope::AlwaysAllocateScope(Isolate* isolate)
      : heap_(isolate->heap()), daf_(isolate) {
    heap_->always_allocate_scope_depth_++;
  }
  
  
  AlwaysAllocateScope::~AlwaysAllocateScope() {
    heap_->always_allocate_scope_depth_--;
  }
  
  
  GCCallbacksScope::GCCallbacksScope(Heap* heap) : heap_(heap) {
    heap_->gc_callbacks_depth_++;
  }
  
  
  GCCallbacksScope::~GCCallbacksScope() { heap_->gc_callbacks_depth_--; }
  
  
  bool GCCallbacksScope::CheckReenter() {
    return heap_->gc_callbacks_depth_ == 1;
  }
  
  
  void VerifyPointersVisitor::VisitPointers(Object** start, Object** end) {
    for (Object** current = start; current < end; current++) {
      if ((*current)->IsHeapObject()) {
        HeapObject* object = HeapObject::cast(*current);
        CHECK(object->GetIsolate()->heap()->Contains(object));
        CHECK(object->map()->IsMap());
      }
    }
  }
  
  
  void VerifySmisVisitor::VisitPointers(Object** start, Object** end) {
    for (Object** current = start; current < end; current++) {
      CHECK((*current)->IsSmi());
    }
  }
  }
  }  // namespace v8::internal
  
  #endif  // V8_HEAP_HEAP_INL_H_
  