| // 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_ELEMENTS_H_ |
| #define V8_ELEMENTS_H_ |
| |
| #include "elements-kind.h" |
| #include "objects.h" |
| #include "heap.h" |
| #include "isolate.h" |
| |
| namespace v8 { |
| namespace internal { |
| |
| // Abstract base class for handles that can operate on objects with differing |
| // ElementsKinds. |
| class ElementsAccessor { |
| public: |
| explicit ElementsAccessor(const char* name) : name_(name) { } |
| virtual ~ElementsAccessor() { } |
| |
| virtual ElementsKind kind() const = 0; |
| const char* name() const { return name_; } |
| |
| // Checks the elements of an object for consistency, asserting when a problem |
| // is found. |
| virtual void Validate(JSObject* obj) = 0; |
| |
| // Returns true if a holder contains an element with the specified key |
| // without iterating up the prototype chain. The caller can optionally pass |
| // in the backing store to use for the check, which must be compatible with |
| // the ElementsKind of the ElementsAccessor. If backing_store is NULL, the |
| // holder->elements() is used as the backing store. |
| virtual bool HasElement(Object* receiver, |
| JSObject* holder, |
| uint32_t key, |
| FixedArrayBase* backing_store = NULL) = 0; |
| |
| // Returns the element with the specified key or undefined if there is no such |
| // element. This method doesn't iterate up the prototype chain. The caller |
| // can optionally pass in the backing store to use for the check, which must |
| // be compatible with the ElementsKind of the ElementsAccessor. If |
| // backing_store is NULL, the holder->elements() is used as the backing store. |
| MUST_USE_RESULT virtual MaybeObject* Get( |
| Object* receiver, |
| JSObject* holder, |
| uint32_t key, |
| FixedArrayBase* backing_store = NULL) = 0; |
| |
| // Returns an element's attributes, or ABSENT if there is no such |
| // element. This method doesn't iterate up the prototype chain. The caller |
| // can optionally pass in the backing store to use for the check, which must |
| // be compatible with the ElementsKind of the ElementsAccessor. If |
| // backing_store is NULL, the holder->elements() is used as the backing store. |
| MUST_USE_RESULT virtual PropertyAttributes GetAttributes( |
| Object* receiver, |
| JSObject* holder, |
| uint32_t key, |
| FixedArrayBase* backing_store = NULL) = 0; |
| |
| // Returns an element's type, or NONEXISTENT if there is no such |
| // element. This method doesn't iterate up the prototype chain. The caller |
| // can optionally pass in the backing store to use for the check, which must |
| // be compatible with the ElementsKind of the ElementsAccessor. If |
| // backing_store is NULL, the holder->elements() is used as the backing store. |
| MUST_USE_RESULT virtual PropertyType GetType( |
| Object* receiver, |
| JSObject* holder, |
| uint32_t key, |
| FixedArrayBase* backing_store = NULL) = 0; |
| |
| // Returns an element's accessors, or NULL if the element does not exist or |
| // is plain. This method doesn't iterate up the prototype chain. The caller |
| // can optionally pass in the backing store to use for the check, which must |
| // be compatible with the ElementsKind of the ElementsAccessor. If |
| // backing_store is NULL, the holder->elements() is used as the backing store. |
| MUST_USE_RESULT virtual AccessorPair* GetAccessorPair( |
| Object* receiver, |
| JSObject* holder, |
| uint32_t key, |
| FixedArrayBase* backing_store = NULL) = 0; |
| |
| // Modifies the length data property as specified for JSArrays and resizes the |
| // underlying backing store accordingly. The method honors the semantics of |
| // changing array sizes as defined in EcmaScript 5.1 15.4.5.2, i.e. array that |
| // have non-deletable elements can only be shrunk to the size of highest |
| // element that is non-deletable. |
| MUST_USE_RESULT virtual MaybeObject* SetLength(JSArray* holder, |
| Object* new_length) = 0; |
| |
| // Modifies both the length and capacity of a JSArray, resizing the underlying |
| // backing store as necessary. This method does NOT honor the semantics of |
| // EcmaScript 5.1 15.4.5.2, arrays can be shrunk beyond non-deletable |
| // elements. This method should only be called for array expansion OR by |
| // runtime JavaScript code that use InternalArrays and don't care about |
| // EcmaScript 5.1 semantics. |
| MUST_USE_RESULT virtual MaybeObject* SetCapacityAndLength(JSArray* array, |
| int capacity, |
| int length) = 0; |
| |
| // Deletes an element in an object, returning a new elements backing store. |
| MUST_USE_RESULT virtual MaybeObject* Delete(JSObject* holder, |
| uint32_t key, |
| JSReceiver::DeleteMode mode) = 0; |
| |
| // If kCopyToEnd is specified as the copy_size to CopyElements, it copies all |
| // of elements from source after source_start to the destination array. |
| static const int kCopyToEnd = -1; |
| // If kCopyToEndAndInitializeToHole is specified as the copy_size to |
| // CopyElements, it copies all of elements from source after source_start to |
| // destination array, padding any remaining uninitialized elements in the |
| // destination array with the hole. |
| static const int kCopyToEndAndInitializeToHole = -2; |
| |
| // Copy elements from one backing store to another. Typically, callers specify |
| // the source JSObject or JSArray in source_holder. If the holder's backing |
| // store is available, it can be passed in source and source_holder is |
| // ignored. |
| MUST_USE_RESULT virtual MaybeObject* CopyElements( |
| JSObject* source_holder, |
| uint32_t source_start, |
| ElementsKind source_kind, |
| FixedArrayBase* destination, |
| uint32_t destination_start, |
| int copy_size, |
| FixedArrayBase* source = NULL) = 0; |
| |
| MUST_USE_RESULT MaybeObject* CopyElements(JSObject* from_holder, |
| FixedArrayBase* to, |
| ElementsKind from_kind, |
| FixedArrayBase* from = NULL) { |
| return CopyElements(from_holder, 0, from_kind, to, 0, |
| kCopyToEndAndInitializeToHole, from); |
| } |
| |
| MUST_USE_RESULT virtual MaybeObject* AddElementsToFixedArray( |
| Object* receiver, |
| JSObject* holder, |
| FixedArray* to, |
| FixedArrayBase* from = NULL) = 0; |
| |
| // Returns a shared ElementsAccessor for the specified ElementsKind. |
| static ElementsAccessor* ForKind(ElementsKind elements_kind) { |
| ASSERT(elements_kind < kElementsKindCount); |
| return elements_accessors_[elements_kind]; |
| } |
| |
| static ElementsAccessor* ForArray(FixedArrayBase* array); |
| |
| static void InitializeOncePerProcess(); |
| static void TearDown(); |
| |
| protected: |
| friend class NonStrictArgumentsElementsAccessor; |
| |
| virtual uint32_t GetCapacity(FixedArrayBase* backing_store) = 0; |
| |
| // Element handlers distinguish between indexes and keys when they manipulate |
| // elements. Indexes refer to elements in terms of their location in the |
| // underlying storage's backing store representation, and are between 0 and |
| // GetCapacity. Keys refer to elements in terms of the value that would be |
| // specified in JavaScript to access the element. In most implementations, |
| // keys are equivalent to indexes, and GetKeyForIndex returns the same value |
| // it is passed. In the NumberDictionary ElementsAccessor, GetKeyForIndex maps |
| // the index to a key using the KeyAt method on the NumberDictionary. |
| virtual uint32_t GetKeyForIndex(FixedArrayBase* backing_store, |
| uint32_t index) = 0; |
| |
| private: |
| static ElementsAccessor** elements_accessors_; |
| const char* name_; |
| |
| DISALLOW_COPY_AND_ASSIGN(ElementsAccessor); |
| }; |
| |
| void CheckArrayAbuse(JSObject* obj, const char* op, uint32_t key, |
| bool allow_appending = false); |
| |
| MUST_USE_RESULT MaybeObject* ArrayConstructInitializeElements( |
| JSArray* array, Arguments* args); |
| |
| } } // namespace v8::internal |
| |
| #endif // V8_ELEMENTS_H_ |
