Ben Murdoch | 3ef787d | 2012-04-12 10:51:47 +0100 | [diff] [blame] | 1 | // Copyright 2012 the V8 project authors. All rights reserved. |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame^] | 2 | // Use of this source code is governed by a BSD-style license that can be |
| 3 | // found in the LICENSE file. |
Ben Murdoch | 3ef787d | 2012-04-12 10:51:47 +0100 | [diff] [blame] | 4 | |
| 5 | #ifndef V8_PROPERTY_DETAILS_H_ |
| 6 | #define V8_PROPERTY_DETAILS_H_ |
| 7 | |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame^] | 8 | #include "include/v8.h" |
| 9 | #include "src/allocation.h" |
| 10 | #include "src/utils.h" |
Ben Murdoch | 3ef787d | 2012-04-12 10:51:47 +0100 | [diff] [blame] | 11 | |
| 12 | // Ecma-262 3rd 8.6.1 |
| 13 | enum PropertyAttributes { |
| 14 | NONE = v8::None, |
| 15 | READ_ONLY = v8::ReadOnly, |
| 16 | DONT_ENUM = v8::DontEnum, |
| 17 | DONT_DELETE = v8::DontDelete, |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame^] | 18 | |
| 19 | SEALED = DONT_DELETE, |
| 20 | FROZEN = SEALED | READ_ONLY, |
| 21 | |
| 22 | STRING = 8, // Used to filter symbols and string names |
| 23 | SYMBOLIC = 16, |
| 24 | PRIVATE_SYMBOL = 32, |
| 25 | |
| 26 | DONT_SHOW = DONT_ENUM | SYMBOLIC | PRIVATE_SYMBOL, |
| 27 | ABSENT = 64 // Used in runtime to indicate a property is absent. |
Ben Murdoch | 3ef787d | 2012-04-12 10:51:47 +0100 | [diff] [blame] | 28 | // ABSENT can never be stored in or returned from a descriptor's attributes |
| 29 | // bitfield. It is only used as a return value meaning the attributes of |
| 30 | // a non-existent property. |
| 31 | }; |
| 32 | |
| 33 | |
| 34 | namespace v8 { |
| 35 | namespace internal { |
| 36 | |
| 37 | class Smi; |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame^] | 38 | template<class> class TypeImpl; |
| 39 | struct ZoneTypeConfig; |
| 40 | typedef TypeImpl<ZoneTypeConfig> Type; |
| 41 | class TypeInfo; |
Ben Murdoch | 3ef787d | 2012-04-12 10:51:47 +0100 | [diff] [blame] | 42 | |
| 43 | // Type of properties. |
| 44 | // Order of properties is significant. |
| 45 | // Must fit in the BitField PropertyDetails::TypeField. |
| 46 | // A copy of this is in mirror-debugger.js. |
| 47 | enum PropertyType { |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame^] | 48 | // Only in slow mode. |
| 49 | NORMAL = 0, |
| 50 | // Only in fast mode. |
| 51 | FIELD = 1, |
| 52 | CONSTANT = 2, |
| 53 | CALLBACKS = 3 |
Ben Murdoch | 3ef787d | 2012-04-12 10:51:47 +0100 | [diff] [blame] | 54 | }; |
| 55 | |
| 56 | |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame^] | 57 | class Representation { |
| 58 | public: |
| 59 | enum Kind { |
| 60 | kNone, |
| 61 | kInteger8, |
| 62 | kUInteger8, |
| 63 | kInteger16, |
| 64 | kUInteger16, |
| 65 | kSmi, |
| 66 | kInteger32, |
| 67 | kDouble, |
| 68 | kHeapObject, |
| 69 | kTagged, |
| 70 | kExternal, |
| 71 | kNumRepresentations |
| 72 | }; |
| 73 | |
| 74 | Representation() : kind_(kNone) { } |
| 75 | |
| 76 | static Representation None() { return Representation(kNone); } |
| 77 | static Representation Tagged() { return Representation(kTagged); } |
| 78 | static Representation Integer8() { return Representation(kInteger8); } |
| 79 | static Representation UInteger8() { return Representation(kUInteger8); } |
| 80 | static Representation Integer16() { return Representation(kInteger16); } |
| 81 | static Representation UInteger16() { return Representation(kUInteger16); } |
| 82 | static Representation Smi() { return Representation(kSmi); } |
| 83 | static Representation Integer32() { return Representation(kInteger32); } |
| 84 | static Representation Double() { return Representation(kDouble); } |
| 85 | static Representation HeapObject() { return Representation(kHeapObject); } |
| 86 | static Representation External() { return Representation(kExternal); } |
| 87 | |
| 88 | static Representation FromKind(Kind kind) { return Representation(kind); } |
| 89 | |
| 90 | static Representation FromType(Type* type); |
| 91 | |
| 92 | bool Equals(const Representation& other) const { |
| 93 | return kind_ == other.kind_; |
| 94 | } |
| 95 | |
| 96 | bool IsCompatibleForLoad(const Representation& other) const { |
| 97 | return (IsDouble() && other.IsDouble()) || |
| 98 | (!IsDouble() && !other.IsDouble()); |
| 99 | } |
| 100 | |
| 101 | bool IsCompatibleForStore(const Representation& other) const { |
| 102 | return Equals(other); |
| 103 | } |
| 104 | |
| 105 | bool is_more_general_than(const Representation& other) const { |
| 106 | if (kind_ == kExternal && other.kind_ == kNone) return true; |
| 107 | if (kind_ == kExternal && other.kind_ == kExternal) return false; |
| 108 | if (kind_ == kNone && other.kind_ == kExternal) return false; |
| 109 | |
| 110 | DCHECK(kind_ != kExternal); |
| 111 | DCHECK(other.kind_ != kExternal); |
| 112 | if (IsHeapObject()) return other.IsNone(); |
| 113 | if (kind_ == kUInteger8 && other.kind_ == kInteger8) return false; |
| 114 | if (kind_ == kUInteger16 && other.kind_ == kInteger16) return false; |
| 115 | return kind_ > other.kind_; |
| 116 | } |
| 117 | |
| 118 | bool fits_into(const Representation& other) const { |
| 119 | return other.is_more_general_than(*this) || other.Equals(*this); |
| 120 | } |
| 121 | |
| 122 | Representation generalize(Representation other) { |
| 123 | if (other.fits_into(*this)) return *this; |
| 124 | if (other.is_more_general_than(*this)) return other; |
| 125 | return Representation::Tagged(); |
| 126 | } |
| 127 | |
| 128 | int size() const { |
| 129 | DCHECK(!IsNone()); |
| 130 | if (IsInteger8() || IsUInteger8()) { |
| 131 | return sizeof(uint8_t); |
| 132 | } |
| 133 | if (IsInteger16() || IsUInteger16()) { |
| 134 | return sizeof(uint16_t); |
| 135 | } |
| 136 | if (IsInteger32()) { |
| 137 | return sizeof(uint32_t); |
| 138 | } |
| 139 | return kPointerSize; |
| 140 | } |
| 141 | |
| 142 | Kind kind() const { return static_cast<Kind>(kind_); } |
| 143 | bool IsNone() const { return kind_ == kNone; } |
| 144 | bool IsInteger8() const { return kind_ == kInteger8; } |
| 145 | bool IsUInteger8() const { return kind_ == kUInteger8; } |
| 146 | bool IsInteger16() const { return kind_ == kInteger16; } |
| 147 | bool IsUInteger16() const { return kind_ == kUInteger16; } |
| 148 | bool IsTagged() const { return kind_ == kTagged; } |
| 149 | bool IsSmi() const { return kind_ == kSmi; } |
| 150 | bool IsSmiOrTagged() const { return IsSmi() || IsTagged(); } |
| 151 | bool IsInteger32() const { return kind_ == kInteger32; } |
| 152 | bool IsSmiOrInteger32() const { return IsSmi() || IsInteger32(); } |
| 153 | bool IsDouble() const { return kind_ == kDouble; } |
| 154 | bool IsHeapObject() const { return kind_ == kHeapObject; } |
| 155 | bool IsExternal() const { return kind_ == kExternal; } |
| 156 | bool IsSpecialization() const { |
| 157 | return IsInteger8() || IsUInteger8() || |
| 158 | IsInteger16() || IsUInteger16() || |
| 159 | IsSmi() || IsInteger32() || IsDouble(); |
| 160 | } |
| 161 | const char* Mnemonic() const; |
| 162 | |
| 163 | private: |
| 164 | explicit Representation(Kind k) : kind_(k) { } |
| 165 | |
| 166 | // Make sure kind fits in int8. |
| 167 | STATIC_ASSERT(kNumRepresentations <= (1 << kBitsPerByte)); |
| 168 | |
| 169 | int8_t kind_; |
| 170 | }; |
| 171 | |
| 172 | |
| 173 | static const int kDescriptorIndexBitCount = 10; |
| 174 | // The maximum number of descriptors we want in a descriptor array (should |
| 175 | // fit in a page). |
| 176 | static const int kMaxNumberOfDescriptors = |
| 177 | (1 << kDescriptorIndexBitCount) - 2; |
| 178 | static const int kInvalidEnumCacheSentinel = |
| 179 | (1 << kDescriptorIndexBitCount) - 1; |
| 180 | |
| 181 | |
Ben Murdoch | 3ef787d | 2012-04-12 10:51:47 +0100 | [diff] [blame] | 182 | // PropertyDetails captures type and attributes for a property. |
| 183 | // They are used both in property dictionaries and instance descriptors. |
| 184 | class PropertyDetails BASE_EMBEDDED { |
| 185 | public: |
| 186 | PropertyDetails(PropertyAttributes attributes, |
| 187 | PropertyType type, |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame^] | 188 | int index) { |
Ben Murdoch | 3ef787d | 2012-04-12 10:51:47 +0100 | [diff] [blame] | 189 | value_ = TypeField::encode(type) |
| 190 | | AttributesField::encode(attributes) |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame^] | 191 | | DictionaryStorageField::encode(index); |
Ben Murdoch | 3ef787d | 2012-04-12 10:51:47 +0100 | [diff] [blame] | 192 | |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame^] | 193 | DCHECK(type == this->type()); |
| 194 | DCHECK(attributes == this->attributes()); |
| 195 | } |
| 196 | |
| 197 | PropertyDetails(PropertyAttributes attributes, |
| 198 | PropertyType type, |
| 199 | Representation representation, |
| 200 | int field_index = 0) { |
| 201 | value_ = TypeField::encode(type) |
| 202 | | AttributesField::encode(attributes) |
| 203 | | RepresentationField::encode(EncodeRepresentation(representation)) |
| 204 | | FieldIndexField::encode(field_index); |
| 205 | } |
| 206 | |
| 207 | int pointer() const { return DescriptorPointer::decode(value_); } |
| 208 | |
| 209 | PropertyDetails set_pointer(int i) { return PropertyDetails(value_, i); } |
| 210 | |
| 211 | PropertyDetails CopyWithRepresentation(Representation representation) const { |
| 212 | return PropertyDetails(value_, representation); |
| 213 | } |
| 214 | PropertyDetails CopyAddAttributes(PropertyAttributes new_attributes) { |
| 215 | new_attributes = |
| 216 | static_cast<PropertyAttributes>(attributes() | new_attributes); |
| 217 | return PropertyDetails(value_, new_attributes); |
Ben Murdoch | 3ef787d | 2012-04-12 10:51:47 +0100 | [diff] [blame] | 218 | } |
| 219 | |
| 220 | // Conversion for storing details as Object*. |
| 221 | explicit inline PropertyDetails(Smi* smi); |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame^] | 222 | inline Smi* AsSmi() const; |
Ben Murdoch | 3ef787d | 2012-04-12 10:51:47 +0100 | [diff] [blame] | 223 | |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame^] | 224 | static uint8_t EncodeRepresentation(Representation representation) { |
| 225 | return representation.kind(); |
Ben Murdoch | 3ef787d | 2012-04-12 10:51:47 +0100 | [diff] [blame] | 226 | } |
| 227 | |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame^] | 228 | static Representation DecodeRepresentation(uint32_t bits) { |
| 229 | return Representation::FromKind(static_cast<Representation::Kind>(bits)); |
| 230 | } |
| 231 | |
| 232 | PropertyType type() const { return TypeField::decode(value_); } |
| 233 | |
| 234 | PropertyAttributes attributes() const { |
| 235 | return AttributesField::decode(value_); |
| 236 | } |
| 237 | |
| 238 | int dictionary_index() const { |
| 239 | return DictionaryStorageField::decode(value_); |
| 240 | } |
| 241 | |
| 242 | Representation representation() const { |
| 243 | DCHECK(type() != NORMAL); |
| 244 | return DecodeRepresentation(RepresentationField::decode(value_)); |
| 245 | } |
| 246 | |
| 247 | int field_index() const { |
| 248 | return FieldIndexField::decode(value_); |
| 249 | } |
| 250 | |
| 251 | inline PropertyDetails AsDeleted() const; |
| 252 | |
| 253 | static bool IsValidIndex(int index) { |
| 254 | return DictionaryStorageField::is_valid(index); |
| 255 | } |
| 256 | |
| 257 | bool IsReadOnly() const { return (attributes() & READ_ONLY) != 0; } |
| 258 | bool IsConfigurable() const { return (attributes() & DONT_DELETE) == 0; } |
| 259 | bool IsDontEnum() const { return (attributes() & DONT_ENUM) != 0; } |
| 260 | bool IsDeleted() const { return DeletedField::decode(value_) != 0;} |
Ben Murdoch | 3ef787d | 2012-04-12 10:51:47 +0100 | [diff] [blame] | 261 | |
| 262 | // Bit fields in value_ (type, shift, size). Must be public so the |
| 263 | // constants can be embedded in generated code. |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame^] | 264 | class TypeField : public BitField<PropertyType, 0, 2> {}; |
| 265 | class AttributesField : public BitField<PropertyAttributes, 2, 3> {}; |
| 266 | |
| 267 | // Bit fields for normalized objects. |
| 268 | class DeletedField : public BitField<uint32_t, 5, 1> {}; |
| 269 | class DictionaryStorageField : public BitField<uint32_t, 6, 24> {}; |
| 270 | |
| 271 | // Bit fields for fast objects. |
| 272 | class RepresentationField : public BitField<uint32_t, 5, 4> {}; |
| 273 | class DescriptorPointer |
| 274 | : public BitField<uint32_t, 9, kDescriptorIndexBitCount> {}; // NOLINT |
| 275 | class FieldIndexField |
| 276 | : public BitField<uint32_t, 9 + kDescriptorIndexBitCount, |
| 277 | kDescriptorIndexBitCount> {}; // NOLINT |
| 278 | // All bits for fast objects must fix in a smi. |
| 279 | STATIC_ASSERT(9 + kDescriptorIndexBitCount + kDescriptorIndexBitCount <= 31); |
Ben Murdoch | 3ef787d | 2012-04-12 10:51:47 +0100 | [diff] [blame] | 280 | |
| 281 | static const int kInitialIndex = 1; |
| 282 | |
| 283 | private: |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame^] | 284 | PropertyDetails(int value, int pointer) { |
| 285 | value_ = DescriptorPointer::update(value, pointer); |
| 286 | } |
| 287 | PropertyDetails(int value, Representation representation) { |
| 288 | value_ = RepresentationField::update( |
| 289 | value, EncodeRepresentation(representation)); |
| 290 | } |
| 291 | PropertyDetails(int value, PropertyAttributes attributes) { |
| 292 | value_ = AttributesField::update(value, attributes); |
| 293 | } |
| 294 | |
Ben Murdoch | 3ef787d | 2012-04-12 10:51:47 +0100 | [diff] [blame] | 295 | uint32_t value_; |
| 296 | }; |
| 297 | |
| 298 | } } // namespace v8::internal |
| 299 | |
| 300 | #endif // V8_PROPERTY_DETAILS_H_ |