Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame^] | 1 | // Copyright 2014 the V8 project authors. All rights reserved. |
| 2 | // Use of this source code is governed by a BSD-style license that can be |
| 3 | // found in the LICENSE file. |
| 4 | |
| 5 | #ifndef V8_LOOKUP_H_ |
| 6 | #define V8_LOOKUP_H_ |
| 7 | |
| 8 | #include "src/factory.h" |
| 9 | #include "src/isolate.h" |
| 10 | #include "src/objects.h" |
| 11 | |
| 12 | namespace v8 { |
| 13 | namespace internal { |
| 14 | |
| 15 | class LookupIterator FINAL BASE_EMBEDDED { |
| 16 | public: |
| 17 | enum Configuration { |
| 18 | // Configuration bits. |
| 19 | kHidden = 1 << 0, |
| 20 | kInterceptor = 1 << 1, |
| 21 | kPrototypeChain = 1 << 2, |
| 22 | |
| 23 | // Convience combinations of bits. |
| 24 | OWN_SKIP_INTERCEPTOR = 0, |
| 25 | OWN = kInterceptor, |
| 26 | HIDDEN_SKIP_INTERCEPTOR = kHidden, |
| 27 | HIDDEN = kHidden | kInterceptor, |
| 28 | PROTOTYPE_CHAIN_SKIP_INTERCEPTOR = kHidden | kPrototypeChain, |
| 29 | PROTOTYPE_CHAIN = kHidden | kPrototypeChain | kInterceptor |
| 30 | }; |
| 31 | |
| 32 | enum State { |
| 33 | ACCESS_CHECK, |
| 34 | INTERCEPTOR, |
| 35 | JSPROXY, |
| 36 | NOT_FOUND, |
| 37 | ACCESSOR, |
| 38 | DATA, |
| 39 | TRANSITION, |
| 40 | // Set state_ to BEFORE_PROPERTY to ensure that the next lookup will be a |
| 41 | // PROPERTY lookup. |
| 42 | BEFORE_PROPERTY = INTERCEPTOR |
| 43 | }; |
| 44 | |
| 45 | LookupIterator(Handle<Object> receiver, Handle<Name> name, |
| 46 | Configuration configuration = PROTOTYPE_CHAIN) |
| 47 | : configuration_(ComputeConfiguration(configuration, name)), |
| 48 | state_(NOT_FOUND), |
| 49 | property_details_(NONE, NORMAL, Representation::None()), |
| 50 | isolate_(name->GetIsolate()), |
| 51 | name_(name), |
| 52 | receiver_(receiver), |
| 53 | number_(DescriptorArray::kNotFound) { |
| 54 | holder_ = GetRoot(); |
| 55 | holder_map_ = handle(holder_->map(), isolate_); |
| 56 | Next(); |
| 57 | } |
| 58 | |
| 59 | LookupIterator(Handle<Object> receiver, Handle<Name> name, |
| 60 | Handle<JSReceiver> holder, |
| 61 | Configuration configuration = PROTOTYPE_CHAIN) |
| 62 | : configuration_(ComputeConfiguration(configuration, name)), |
| 63 | state_(NOT_FOUND), |
| 64 | property_details_(NONE, NORMAL, Representation::None()), |
| 65 | isolate_(name->GetIsolate()), |
| 66 | name_(name), |
| 67 | holder_map_(holder->map(), isolate_), |
| 68 | receiver_(receiver), |
| 69 | holder_(holder), |
| 70 | number_(DescriptorArray::kNotFound) { |
| 71 | Next(); |
| 72 | } |
| 73 | |
| 74 | Isolate* isolate() const { return isolate_; } |
| 75 | State state() const { return state_; } |
| 76 | Handle<Name> name() const { return name_; } |
| 77 | |
| 78 | bool IsFound() const { return state_ != NOT_FOUND; } |
| 79 | void Next(); |
| 80 | void NotFound() { |
| 81 | has_property_ = false; |
| 82 | state_ = NOT_FOUND; |
| 83 | } |
| 84 | |
| 85 | Factory* factory() const { return isolate_->factory(); } |
| 86 | Handle<Object> GetReceiver() const { return receiver_; } |
| 87 | Handle<JSObject> GetStoreTarget() const; |
| 88 | bool is_dictionary_holder() const { return holder_map_->is_dictionary_map(); } |
| 89 | Handle<Map> transition_map() const { |
| 90 | DCHECK_EQ(TRANSITION, state_); |
| 91 | return transition_map_; |
| 92 | } |
| 93 | template <class T> |
| 94 | Handle<T> GetHolder() const { |
| 95 | DCHECK(IsFound()); |
| 96 | return Handle<T>::cast(holder_); |
| 97 | } |
| 98 | Handle<JSReceiver> GetRoot() const; |
| 99 | bool HolderIsReceiverOrHiddenPrototype() const; |
| 100 | |
| 101 | /* ACCESS_CHECK */ |
| 102 | bool HasAccess(v8::AccessType access_type) const; |
| 103 | |
| 104 | /* PROPERTY */ |
| 105 | void PrepareForDataProperty(Handle<Object> value); |
| 106 | void PrepareTransitionToDataProperty(Handle<Object> value, |
| 107 | PropertyAttributes attributes, |
| 108 | Object::StoreFromKeyed store_mode); |
| 109 | bool IsCacheableTransition() { |
| 110 | bool cacheable = |
| 111 | state_ == TRANSITION && transition_map()->GetBackPointer()->IsMap(); |
| 112 | if (cacheable) { |
| 113 | property_details_ = transition_map_->GetLastDescriptorDetails(); |
| 114 | has_property_ = true; |
| 115 | } |
| 116 | return cacheable; |
| 117 | } |
| 118 | void ApplyTransitionToDataProperty(); |
| 119 | void ReconfigureDataProperty(Handle<Object> value, |
| 120 | PropertyAttributes attributes); |
| 121 | void TransitionToAccessorProperty(AccessorComponent component, |
| 122 | Handle<Object> accessor, |
| 123 | PropertyAttributes attributes); |
| 124 | PropertyDetails property_details() const { |
| 125 | DCHECK(has_property_); |
| 126 | return property_details_; |
| 127 | } |
| 128 | bool IsConfigurable() const { return property_details().IsConfigurable(); } |
| 129 | bool IsReadOnly() const { return property_details().IsReadOnly(); } |
| 130 | Representation representation() const { |
| 131 | return property_details().representation(); |
| 132 | } |
| 133 | FieldIndex GetFieldIndex() const; |
| 134 | Handle<HeapType> GetFieldType() const; |
| 135 | int GetConstantIndex() const; |
| 136 | Handle<PropertyCell> GetPropertyCell() const; |
| 137 | Handle<Object> GetAccessors() const; |
| 138 | Handle<Object> GetDataValue() const; |
| 139 | void WriteDataValue(Handle<Object> value); |
| 140 | |
| 141 | void InternalizeName(); |
| 142 | |
| 143 | private: |
| 144 | Handle<Map> GetReceiverMap() const; |
| 145 | |
| 146 | MUST_USE_RESULT inline JSReceiver* NextHolder(Map* map); |
| 147 | inline State LookupInHolder(Map* map, JSReceiver* holder); |
| 148 | Handle<Object> FetchValue() const; |
| 149 | void ReloadPropertyInformation(); |
| 150 | |
| 151 | bool IsBootstrapping() const; |
| 152 | |
| 153 | bool check_hidden() const { return (configuration_ & kHidden) != 0; } |
| 154 | bool check_interceptor() const { |
| 155 | return !IsBootstrapping() && (configuration_ & kInterceptor) != 0; |
| 156 | } |
| 157 | bool check_prototype_chain() const { |
| 158 | return (configuration_ & kPrototypeChain) != 0; |
| 159 | } |
| 160 | int descriptor_number() const { |
| 161 | DCHECK(has_property_); |
| 162 | DCHECK(!holder_map_->is_dictionary_map()); |
| 163 | return number_; |
| 164 | } |
| 165 | int dictionary_entry() const { |
| 166 | DCHECK(has_property_); |
| 167 | DCHECK(holder_map_->is_dictionary_map()); |
| 168 | return number_; |
| 169 | } |
| 170 | |
| 171 | static Configuration ComputeConfiguration( |
| 172 | Configuration configuration, Handle<Name> name) { |
| 173 | if (name->IsOwn()) { |
| 174 | return static_cast<Configuration>(configuration & HIDDEN); |
| 175 | } else { |
| 176 | return configuration; |
| 177 | } |
| 178 | } |
| 179 | |
| 180 | // If configuration_ becomes mutable, update |
| 181 | // HolderIsReceiverOrHiddenPrototype. |
| 182 | Configuration configuration_; |
| 183 | State state_; |
| 184 | bool has_property_; |
| 185 | PropertyDetails property_details_; |
| 186 | Isolate* isolate_; |
| 187 | Handle<Name> name_; |
| 188 | Handle<Map> holder_map_; |
| 189 | Handle<Map> transition_map_; |
| 190 | Handle<Object> receiver_; |
| 191 | Handle<JSReceiver> holder_; |
| 192 | |
| 193 | int number_; |
| 194 | }; |
| 195 | |
| 196 | |
| 197 | } } // namespace v8::internal |
| 198 | |
| 199 | #endif // V8_LOOKUP_H_ |