objects-inl.h.svn-base

Google浏览器V8内核代码

}


bool Dictionary::requires_slow_elements() {
  Object* max_index_object = get(kPrefixStartIndex);
  if (!max_index_object->IsSmi()) return false;
  return 0 !=
      (Smi::cast(max_index_object)->value() & kRequiresSlowElementsMask);
}


uint32_t Dictionary::max_number_key() {
  ASSERT(!requires_slow_elements());
  Object* max_index_object = get(kPrefixStartIndex);
  if (!max_index_object->IsSmi()) return 0;
  uint32_t value = static_cast<uint32_t>(Smi::cast(max_index_object)->value());
  return value >> kRequiresSlowElementsTagSize;
}


// ------------------------------------
// Cast operations


CAST_ACCESSOR(FixedArray)
CAST_ACCESSOR(DescriptorArray)
CAST_ACCESSOR(Dictionary)
CAST_ACCESSOR(SymbolTable)
CAST_ACCESSOR(CompilationCacheTable)
CAST_ACCESSOR(MapCache)
CAST_ACCESSOR(String)
CAST_ACCESSOR(SeqString)
CAST_ACCESSOR(AsciiString)
CAST_ACCESSOR(TwoByteString)
CAST_ACCESSOR(ConsString)
CAST_ACCESSOR(SlicedString)
CAST_ACCESSOR(ExternalString)
CAST_ACCESSOR(ExternalAsciiString)
CAST_ACCESSOR(ExternalTwoByteString)
CAST_ACCESSOR(JSObject)
CAST_ACCESSOR(Smi)
CAST_ACCESSOR(Failure)
CAST_ACCESSOR(HeapObject)
CAST_ACCESSOR(HeapNumber)
CAST_ACCESSOR(Oddball)
CAST_ACCESSOR(SharedFunctionInfo)
CAST_ACCESSOR(Map)
CAST_ACCESSOR(JSFunction)
CAST_ACCESSOR(JSGlobalObject)
CAST_ACCESSOR(JSBuiltinsObject)
CAST_ACCESSOR(Code)
CAST_ACCESSOR(JSArray)
CAST_ACCESSOR(JSRegExp)
CAST_ACCESSOR(Proxy)
CAST_ACCESSOR(ByteArray)
CAST_ACCESSOR(Struct)


#define MAKE_STRUCT_CAST(NAME, Name, name) CAST_ACCESSOR(Name)
  STRUCT_LIST(MAKE_STRUCT_CAST)
#undef MAKE_STRUCT_CAST

template <int prefix_size, int elem_size>
HashTable<prefix_size, elem_size>* HashTable<prefix_size, elem_size>::cast(
    Object* obj) {
  ASSERT(obj->IsHashTable());
  return reinterpret_cast<HashTable*>(obj);
}


INT_ACCESSORS(Array, length, kLengthOffset)


bool String::Equals(String* other) {
  if (other == this) return true;
  if (IsSymbol() && other->IsSymbol()) return false;
  return SlowEquals(other);
}


int String::length() {
  uint32_t len = READ_INT_FIELD(this, kLengthOffset);

  switch (size_tag()) {
    case kShortStringTag:
      return  len >> kShortLengthShift;
    case kMediumStringTag:
      return len >> kMediumLengthShift;
    case kLongStringTag:
      return len >> kLongLengthShift;
    default:
      break;
  }
  UNREACHABLE();
  return 0;
}


void String::set_length(int value) {
  switch (size_tag()) {
    case kShortStringTag:
      WRITE_INT_FIELD(this, kLengthOffset, value << kShortLengthShift);
      break;
    case kMediumStringTag:
      WRITE_INT_FIELD(this, kLengthOffset, value << kMediumLengthShift);
      break;
    case kLongStringTag:
      WRITE_INT_FIELD(this, kLengthOffset, value << kLongLengthShift);
      break;
    default:
      UNREACHABLE();
      break;
  }
}


int String::length_field() {
  return READ_INT_FIELD(this, kLengthOffset);
}


void String::set_length_field(int value) {
  WRITE_INT_FIELD(this, kLengthOffset, value);
}


void String::TryFlatten() {
  // We don't need to flatten strings that are already flat.  Since this code
  // is inlined, it can be helpful in the flat case to not call out to Flatten.
  StringRepresentationTag str_type = representation_tag();
  if (str_type != kSeqStringTag && str_type != kExternalStringTag) {
    Flatten();
  }
}


uint16_t String::Get(int index) {
  ASSERT(index >= 0 && index < length());
  switch (representation_tag()) {
    case kSeqStringTag:
      return is_ascii()
        ? AsciiString::cast(this)->AsciiStringGet(index)
        : TwoByteString::cast(this)->TwoByteStringGet(index);
    case kConsStringTag:
      return ConsString::cast(this)->ConsStringGet(index);
    case kSlicedStringTag:
      return SlicedString::cast(this)->SlicedStringGet(index);
    case kExternalStringTag:
      return is_ascii()
        ? ExternalAsciiString::cast(this)->ExternalAsciiStringGet(index)
        : ExternalTwoByteString::cast(this)->ExternalTwoByteStringGet(index);
    default:
      break;
  }

  UNREACHABLE();
  return 0;
}


void String::Set(int index, uint16_t value) {
  ASSERT(index >= 0 && index < length());
  ASSERT(IsSeqString());

  return is_ascii()
      ? AsciiString::cast(this)->AsciiStringSet(index, value)
      : TwoByteString::cast(this)->TwoByteStringSet(index, value);
}


bool String::IsAscii() {
  return is_ascii();
}


bool String::StringIsConsString() {
  return representation_tag() == kConsStringTag;
}


bool String::StringIsSlicedString() {
  return representation_tag() == kSlicedStringTag;
}


uint32_t String::size_tag() {
  return map_size_tag(map());
}


uint32_t String::map_size_tag(Map* map) {
  return map->instance_type() & kStringSizeMask;
}


bool String::is_symbol() {
  return is_symbol_map(map());
}


bool String::is_symbol_map(Map* map) {
  return (map->instance_type() & kIsSymbolMask) != 0;
}


bool String::is_ascii() {
  return is_ascii_map(map());
}


bool String::is_ascii_map(Map* map) {
  return (map->instance_type() & kStringEncodingMask) != 0;
}


StringRepresentationTag String::representation_tag() {
  return map_representation_tag(map());
}


StringRepresentationTag String::map_representation_tag(Map* map) {
  uint32_t tag = map->instance_type() & kStringRepresentationMask;
  return static_cast<StringRepresentationTag>(tag);
}


bool String::IsFlat() {
  String* current = this;
  while (true) {
    switch (current->representation_tag()) {
      case kConsStringTag:
        return String::cast(ConsString::cast(current)->second())->length() == 0;
      case kSlicedStringTag:
        current = String::cast(SlicedString::cast(this)->buffer());
        break;
      default:
        return true;
    }
  }
}


uint16_t AsciiString::AsciiStringGet(int index) {
  ASSERT(index >= 0 && index < length());
  return READ_BYTE_FIELD(this, kHeaderSize + index * kCharSize);
}


void AsciiString::AsciiStringSet(int index, uint16_t value) {
  ASSERT(index >= 0 && index < length() && value <= kMaxAsciiCharCode);
  WRITE_BYTE_FIELD(this, kHeaderSize + index * kCharSize,
                   static_cast<byte>(value));
}


Address AsciiString::GetCharsAddress() {
  return FIELD_ADDR(this, kHeaderSize);
}


uint16_t TwoByteString::TwoByteStringGet(int index) {
  ASSERT(index >= 0 && index < length());
  return READ_SHORT_FIELD(this, kHeaderSize + index * kShortSize);
}


void TwoByteString::TwoByteStringSet(int index, uint16_t value) {
  ASSERT(index >= 0 && index < length());
  WRITE_SHORT_FIELD(this, kHeaderSize + index * kShortSize, value);
}


int TwoByteString::TwoByteStringSize(Map* map) {
  uint32_t length = READ_INT_FIELD(this, kLengthOffset);

  // Use the map (and not 'this') to compute the size tag, since
  // TwoByteStringSize is called during GC when maps are encoded.
  switch (map_size_tag(map)) {
    case kShortStringTag:
      length = length >> kShortLengthShift;
      break;
    case kMediumStringTag:
      length = length >> kMediumLengthShift;
      break;
    case kLongStringTag:
      length = length >> kLongLengthShift;
      break;
    default:
      break;
  }
  return SizeFor(length);
}


int AsciiString::AsciiStringSize(Map* map) {
  uint32_t length = READ_INT_FIELD(this, kLengthOffset);

  // Use the map (and not 'this') to compute the size tag, since
  // AsciiStringSize is called during GC when maps are encoded.
  switch (map_size_tag(map)) {
    case kShortStringTag:
      length = length >> kShortLengthShift;
      break;
    case kMediumStringTag:
      length = length >> kMediumLengthShift;
      break;
    case kLongStringTag:
      length = length >> kLongLengthShift;
      break;
    default:
      break;
  }

  return SizeFor(length);
}


Object* ConsString::first() {
  return READ_FIELD(this, kFirstOffset);
}


void ConsString::set_first(Object* value) {
  WRITE_FIELD(this, kFirstOffset, value);
  WRITE_BARRIER(this, kFirstOffset);
}


Object* ConsString::second() {
  return READ_FIELD(this, kSecondOffset);
}


void ConsString::set_second(Object* value) {
  WRITE_FIELD(this, kSecondOffset, value);
  WRITE_BARRIER(this, kSecondOffset);
}


Object* SlicedString::buffer() {
  return READ_FIELD(this, kBufferOffset);
}


void SlicedString::set_buffer(Object* buffer) {
  WRITE_FIELD(this, kBufferOffset, buffer);
  WRITE_BARRIER(this, kBufferOffset);
}


int SlicedString::start() {
  return READ_INT_FIELD(this, kStartOffset);
}


void SlicedString::set_start(int start) {
  WRITE_INT_FIELD(this, kStartOffset, start);
}


ExternalAsciiString::Resource* ExternalAsciiString::resource() {
  return *reinterpret_cast<Resource**>(FIELD_ADDR(this, kResourceOffset));
}


void ExternalAsciiString::set_resource(
    ExternalAsciiString::Resource* resource) {
  *reinterpret_cast<Resource**>(FIELD_ADDR(this, kResourceOffset)) = resource;
}


ExternalTwoByteString::Resource* ExternalTwoByteString::resource() {
  return *reinterpret_cast<Resource**>(FIELD_ADDR(this, kResourceOffset));
}


void ExternalTwoByteString::set_resource(
    ExternalTwoByteString::Resource* resource) {
  *reinterpret_cast<Resource**>(FIELD_ADDR(this, kResourceOffset)) = resource;
}


byte ByteArray::get(int index) {
  ASSERT(index >= 0 && index < this->length());
  return READ_BYTE_FIELD(this, kHeaderSize + index * kCharSize);
}


void ByteArray::set(int index, byte value) {
  ASSERT(index >= 0 && index < this->length());
  WRITE_BYTE_FIELD(this, kHeaderSize + index * kCharSize, value);
}


int ByteArray::get_int(int index) {
  ASSERT(index >= 0 && (index * kIntSize) < this->length());
  return READ_INT_FIELD(this, kHeaderSize + index * kIntSize);
}


ByteArray* ByteArray::FromDataStartAddress(Address address) {
  ASSERT_TAG_ALIGNED(address);
  return reinterpret_cast<ByteArray*>(address - kHeaderSize + kHeapObjectTag);
}


Address ByteArray::GetDataStartAddress() {
  return reinterpret_cast<Address>(this) - kHeapObjectTag + kHeaderSize;
}


int Map::instance_size() {
  return READ_BYTE_FIELD(this, kInstanceSizeOffset);
}


int HeapObject::SizeFromMap(Map* map) {
  InstanceType instance_type = map->instance_type();
  // Only inline the two most frequent cases.
  if (instance_type == JS_OBJECT_TYPE) return  map->instance_size();
  if (instance_type == FIXED_ARRAY_TYPE) {
    return reinterpret_cast<FixedArray*>(this)->FixedArraySize();
  }
  // Otherwise do the general size computation.
  return SlowSizeFromMap(map);
}


void Map::set_instance_size(int value) {
  ASSERT(0 <= value && value < 256);
  WRITE_BYTE_FIELD(this, kInstanceSizeOffset, static_cast<byte>(value));
}


InstanceType Map::instance_type() {
  return static_cast<InstanceType>(READ_BYTE_FIELD(this, kInstanceTypeOffset));
}


void Map::set_instance_type(InstanceType value) {
  ASSERT(0 <= value && value < 256);
  WRITE_BYTE_FIELD(this, kInstanceTypeOffset, value);
}


int Map::unused_property_fields() {
  return READ_BYTE_FIELD(this, kUnusedPropertyFieldsOffset);
}


void Map::set_unused_property_fields(int value) {
  WRITE_BYTE_FIELD(this, kUnusedPropertyFieldsOffset, Min(value, 255));
}


byte Map::bit_field() {
  return READ_BYTE_FIELD(this, kBitFieldOffset);
}


void Map::set_bit_field(byte value) {
  WRITE_BYTE_FIELD(this, kBitFieldOffset, value);
}


void Map::set_non_instance_prototype(bool value) {
  if (value) {
    set_bit_field(bit_field() | (1 << kHasNonInstancePrototype));
  } else {
    set_bit_field(bit_field() & ~(1 << kHasNonInstancePrototype));
  }
}


bool Map::has_non_instance_prototype() {
  return ((1 << kHasNonInstancePrototype) & bit_field()) != 0;
}


Code::Flags Code::flags() {
  return static_cast<Flags>(READ_INT_FIELD(this, kFlagsOffset));
}


void Code::set_flags(Code::Flags flags) {
  // Make sure that all call stubs have an arguments count.
  ASSERT(ExtractKindFromFlags(flags) != CALL_IC ||
         ExtractArgumentsCountFromFlags(flags) >= 0);
  WRITE_INT_FIELD(this, kFlagsOffset, flags);
}


Code::Kind Code::kind() {
  return ExtractKindFromFlags(flags());
}


InlineCacheState Code::ic_state() {
  InlineCacheState result = ExtractICStateFromFlags(flags());
  // Only allow uninitialized or debugger states for non-IC code
  // objects. This is used in the debugger to determine whether or not
  // a call to code object has been replaced with a debug break call.
  ASSERT(is_inline_cache_stub() ||
         result == UNINITIALIZED ||
         result == DEBUG_BREAK ||
         result == DEBUG_PREPARE_STEP_IN);
  return result;
}


PropertyType Code::type() {
  ASSERT(ic_state() == MONOMORPHIC);
  return ExtractTypeFromFlags(flags());
}


int Code::arguments_count() {
  ASSERT(is_call_stub() || kind() == STUB);
  return ExtractArgumentsCountFromFlags(flags());
}


CodeStub::Major Code::major_key() {
  ASSERT(kind() == STUB);
  return static_cast<CodeStub::Major>(READ_BYTE_FIELD(this,
                                                      kStubMajorKeyOffset));
}


void Code::set_major_key(CodeStub::Major major) {
  ASSERT(kind() == STUB);
  ASSERT(0 <= major && major < 256);
  WRITE_BYTE_FIELD(this, kStubMajorKeyOffset, major);
}


bool Code::is_inline_cache_stub() {
  Kind kind = this->kind();
  return kind >= FIRST_IC_KIND && kind <= LAST_IC_KIND;
}


Code::Flags Code::ComputeFlags(Kind kind,
                               InlineCacheState ic_state,
                               PropertyType type,