| // 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. |
| |
| #ifndef V8_PROPERTY_DETAILS_H_ |
| #define V8_PROPERTY_DETAILS_H_ |
| |
| #include "../include/v8.h" |
| #include "allocation.h" |
| #include "utils.h" |
| |
| // Ecma-262 3rd 8.6.1 |
| enum PropertyAttributes { |
| NONE = v8::None, |
| READ_ONLY = v8::ReadOnly, |
| DONT_ENUM = v8::DontEnum, |
| DONT_DELETE = v8::DontDelete, |
| |
| SEALED = DONT_DELETE, |
| FROZEN = SEALED | READ_ONLY, |
| |
| SYMBOLIC = 8, // Used to filter symbol names |
| DONT_SHOW = DONT_ENUM | SYMBOLIC, |
| ABSENT = 16 // Used in runtime to indicate a property is absent. |
| // ABSENT can never be stored in or returned from a descriptor's attributes |
| // bitfield. It is only used as a return value meaning the attributes of |
| // a non-existent property. |
| }; |
| |
| |
| namespace v8 { |
| namespace internal { |
| |
| class Smi; |
| class Type; |
| class TypeInfo; |
| |
| // Type of properties. |
| // Order of properties is significant. |
| // Must fit in the BitField PropertyDetails::TypeField. |
| // A copy of this is in mirror-debugger.js. |
| enum PropertyType { |
| // Only in slow mode. |
| NORMAL = 0, |
| // Only in fast mode. |
| FIELD = 1, |
| CONSTANT = 2, |
| CALLBACKS = 3, |
| // Only in lookup results, not in descriptors. |
| HANDLER = 4, |
| INTERCEPTOR = 5, |
| TRANSITION = 6, |
| // Only used as a marker in LookupResult. |
| NONEXISTENT = 7 |
| }; |
| |
| |
| class Representation { |
| public: |
| enum Kind { |
| kNone, |
| kSmi, |
| kInteger32, |
| kDouble, |
| kHeapObject, |
| kTagged, |
| kExternal, |
| kNumRepresentations |
| }; |
| |
| Representation() : kind_(kNone) { } |
| |
| static Representation None() { return Representation(kNone); } |
| static Representation Tagged() { return Representation(kTagged); } |
| static Representation Smi() { return Representation(kSmi); } |
| static Representation Integer32() { return Representation(kInteger32); } |
| static Representation Double() { return Representation(kDouble); } |
| static Representation HeapObject() { return Representation(kHeapObject); } |
| static Representation External() { return Representation(kExternal); } |
| |
| static Representation FromKind(Kind kind) { return Representation(kind); } |
| |
| // TODO(rossberg): this should die eventually. |
| static Representation FromType(TypeInfo info); |
| static Representation FromType(Handle<Type> type); |
| |
| bool Equals(const Representation& other) const { |
| return kind_ == other.kind_; |
| } |
| |
| bool IsCompatibleForLoad(const Representation& other) const { |
| return (IsDouble() && other.IsDouble()) || |
| (!IsDouble() && !other.IsDouble()); |
| } |
| |
| bool IsCompatibleForStore(const Representation& other) const { |
| return Equals(other); |
| } |
| |
| bool is_more_general_than(const Representation& other) const { |
| ASSERT(kind_ != kExternal); |
| ASSERT(other.kind_ != kExternal); |
| if (IsHeapObject()) return other.IsDouble() || other.IsNone(); |
| return kind_ > other.kind_; |
| } |
| |
| bool fits_into(const Representation& other) const { |
| return other.is_more_general_than(*this) || other.Equals(*this); |
| } |
| |
| Representation generalize(Representation other) { |
| if (other.fits_into(*this)) return *this; |
| if (other.is_more_general_than(*this)) return other; |
| return Representation::Tagged(); |
| } |
| |
| Kind kind() const { return static_cast<Kind>(kind_); } |
| bool IsNone() const { return kind_ == kNone; } |
| bool IsTagged() const { return kind_ == kTagged; } |
| bool IsSmi() const { return kind_ == kSmi; } |
| bool IsSmiOrTagged() const { return IsSmi() || IsTagged(); } |
| bool IsInteger32() const { return kind_ == kInteger32; } |
| bool IsSmiOrInteger32() const { return IsSmi() || IsInteger32(); } |
| bool IsDouble() const { return kind_ == kDouble; } |
| bool IsHeapObject() const { return kind_ == kHeapObject; } |
| bool IsExternal() const { return kind_ == kExternal; } |
| bool IsSpecialization() const { |
| return kind_ == kInteger32 || kind_ == kDouble; |
| } |
| const char* Mnemonic() const; |
| |
| private: |
| explicit Representation(Kind k) : kind_(k) { } |
| |
| // Make sure kind fits in int8. |
| STATIC_ASSERT(kNumRepresentations <= (1 << kBitsPerByte)); |
| |
| int8_t kind_; |
| }; |
| |
| |
| // PropertyDetails captures type and attributes for a property. |
| // They are used both in property dictionaries and instance descriptors. |
| class PropertyDetails BASE_EMBEDDED { |
| public: |
| PropertyDetails(PropertyAttributes attributes, |
| PropertyType type, |
| int index) { |
| value_ = TypeField::encode(type) |
| | AttributesField::encode(attributes) |
| | DictionaryStorageField::encode(index); |
| |
| ASSERT(type == this->type()); |
| ASSERT(attributes == this->attributes()); |
| } |
| |
| PropertyDetails(PropertyAttributes attributes, |
| PropertyType type, |
| Representation representation, |
| int field_index = 0) { |
| value_ = TypeField::encode(type) |
| | AttributesField::encode(attributes) |
| | RepresentationField::encode(EncodeRepresentation(representation)) |
| | FieldIndexField::encode(field_index); |
| } |
| |
| int pointer() { return DescriptorPointer::decode(value_); } |
| |
| PropertyDetails set_pointer(int i) { return PropertyDetails(value_, i); } |
| |
| PropertyDetails CopyWithRepresentation(Representation representation) { |
| return PropertyDetails(value_, representation); |
| } |
| PropertyDetails CopyAddAttributes(PropertyAttributes new_attributes) { |
| new_attributes = |
| static_cast<PropertyAttributes>(attributes() | new_attributes); |
| return PropertyDetails(value_, new_attributes); |
| } |
| |
| // Conversion for storing details as Object*. |
| explicit inline PropertyDetails(Smi* smi); |
| inline Smi* AsSmi(); |
| |
| static uint8_t EncodeRepresentation(Representation representation) { |
| return representation.kind(); |
| } |
| |
| static Representation DecodeRepresentation(uint32_t bits) { |
| return Representation::FromKind(static_cast<Representation::Kind>(bits)); |
| } |
| |
| PropertyType type() { return TypeField::decode(value_); } |
| |
| PropertyAttributes attributes() const { |
| return AttributesField::decode(value_); |
| } |
| |
| int dictionary_index() { |
| return DictionaryStorageField::decode(value_); |
| } |
| |
| Representation representation() { |
| ASSERT(type() != NORMAL); |
| return DecodeRepresentation(RepresentationField::decode(value_)); |
| } |
| |
| int field_index() { |
| return FieldIndexField::decode(value_); |
| } |
| |
| inline PropertyDetails AsDeleted(); |
| |
| static bool IsValidIndex(int index) { |
| return DictionaryStorageField::is_valid(index); |
| } |
| |
| bool IsReadOnly() const { return (attributes() & READ_ONLY) != 0; } |
| bool IsDontDelete() const { return (attributes() & DONT_DELETE) != 0; } |
| bool IsDontEnum() const { return (attributes() & DONT_ENUM) != 0; } |
| bool IsDeleted() const { return DeletedField::decode(value_) != 0;} |
| |
| // Bit fields in value_ (type, shift, size). Must be public so the |
| // constants can be embedded in generated code. |
| class TypeField: public BitField<PropertyType, 0, 3> {}; |
| class AttributesField: public BitField<PropertyAttributes, 3, 3> {}; |
| |
| // Bit fields for normalized objects. |
| class DeletedField: public BitField<uint32_t, 6, 1> {}; |
| class DictionaryStorageField: public BitField<uint32_t, 7, 24> {}; |
| |
| // Bit fields for fast objects. |
| class DescriptorPointer: public BitField<uint32_t, 6, 11> {}; |
| class RepresentationField: public BitField<uint32_t, 17, 3> {}; |
| class FieldIndexField: public BitField<uint32_t, 20, 11> {}; |
| |
| static const int kInitialIndex = 1; |
| |
| private: |
| PropertyDetails(int value, int pointer) { |
| value_ = DescriptorPointer::update(value, pointer); |
| } |
| PropertyDetails(int value, Representation representation) { |
| value_ = RepresentationField::update( |
| value, EncodeRepresentation(representation)); |
| } |
| PropertyDetails(int value, PropertyAttributes attributes) { |
| value_ = AttributesField::update(value, attributes); |
| } |
| |
| uint32_t value_; |
| }; |
| |
| } } // namespace v8::internal |
| |
| #endif // V8_PROPERTY_DETAILS_H_ |