| // Copyright 2006-2008 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_HANDLES_H_ |
| #define V8_HANDLES_H_ |
| |
| #include "apiutils.h" |
| |
| namespace v8 { |
| namespace internal { |
| |
| // ---------------------------------------------------------------------------- |
| // A Handle provides a reference to an object that survives relocation by |
| // the garbage collector. |
| // Handles are only valid within a HandleScope. |
| // When a handle is created for an object a cell is allocated in the heap. |
| |
| template<class T> |
| class Handle { |
| public: |
| INLINE(explicit Handle(T** location)) { location_ = location; } |
| INLINE(explicit Handle(T* obj)); |
| |
| INLINE(Handle()) : location_(NULL) {} |
| |
| // Constructor for handling automatic up casting. |
| // Ex. Handle<JSFunction> can be passed when Handle<Object> is expected. |
| template <class S> Handle(Handle<S> handle) { |
| #ifdef DEBUG |
| T* a = NULL; |
| S* b = NULL; |
| a = b; // Fake assignment to enforce type checks. |
| USE(a); |
| #endif |
| location_ = reinterpret_cast<T**>(handle.location()); |
| } |
| |
| INLINE(T* operator ->() const) { return operator*(); } |
| |
| // Check if this handle refers to the exact same object as the other handle. |
| bool is_identical_to(const Handle<T> other) const { |
| return operator*() == *other; |
| } |
| |
| // Provides the C++ dereference operator. |
| INLINE(T* operator*() const); |
| |
| // Returns the address to where the raw pointer is stored. |
| T** location() const { |
| ASSERT(location_ == NULL || |
| reinterpret_cast<Address>(*location_) != kZapValue); |
| return location_; |
| } |
| |
| template <class S> static Handle<T> cast(Handle<S> that) { |
| T::cast(*that); |
| return Handle<T>(reinterpret_cast<T**>(that.location())); |
| } |
| |
| static Handle<T> null() { return Handle<T>(); } |
| bool is_null() { return location_ == NULL; } |
| |
| // Closes the given scope, but lets this handle escape. See |
| // implementation in api.h. |
| inline Handle<T> EscapeFrom(v8::HandleScope* scope); |
| |
| private: |
| T** location_; |
| }; |
| |
| |
| // A stack-allocated class that governs a number of local handles. |
| // After a handle scope has been created, all local handles will be |
| // allocated within that handle scope until either the handle scope is |
| // deleted or another handle scope is created. If there is already a |
| // handle scope and a new one is created, all allocations will take |
| // place in the new handle scope until it is deleted. After that, |
| // new handles will again be allocated in the original handle scope. |
| // |
| // After the handle scope of a local handle has been deleted the |
| // garbage collector will no longer track the object stored in the |
| // handle and may deallocate it. The behavior of accessing a handle |
| // for which the handle scope has been deleted is undefined. |
| class HandleScope { |
| public: |
| HandleScope() : previous_(current_) { |
| current_.extensions = 0; |
| } |
| |
| ~HandleScope() { |
| Leave(&previous_); |
| } |
| |
| // Counts the number of allocated handles. |
| static int NumberOfHandles(); |
| |
| // Creates a new handle with the given value. |
| template <typename T> |
| static inline T** CreateHandle(T* value) { |
| internal::Object** cur = current_.next; |
| if (cur == current_.limit) cur = Extend(); |
| // Update the current next field, set the value in the created |
| // handle, and return the result. |
| ASSERT(cur < current_.limit); |
| current_.next = cur + 1; |
| |
| T** result = reinterpret_cast<T**>(cur); |
| *result = value; |
| return result; |
| } |
| |
| // Deallocates any extensions used by the current scope. |
| static void DeleteExtensions(); |
| |
| static Address current_extensions_address(); |
| static Address current_next_address(); |
| static Address current_limit_address(); |
| |
| private: |
| // Prevent heap allocation or illegal handle scopes. |
| HandleScope(const HandleScope&); |
| void operator=(const HandleScope&); |
| void* operator new(size_t size); |
| void operator delete(void* size_t); |
| |
| static v8::ImplementationUtilities::HandleScopeData current_; |
| const v8::ImplementationUtilities::HandleScopeData previous_; |
| |
| // Pushes a fresh handle scope to be used when allocating new handles. |
| static void Enter( |
| v8::ImplementationUtilities::HandleScopeData* previous) { |
| *previous = current_; |
| current_.extensions = 0; |
| } |
| |
| // Re-establishes the previous scope state. Should be called only |
| // once, and only for the current scope. |
| static void Leave( |
| const v8::ImplementationUtilities::HandleScopeData* previous) { |
| if (current_.extensions > 0) { |
| DeleteExtensions(); |
| } |
| current_ = *previous; |
| #ifdef DEBUG |
| ZapRange(current_.next, current_.limit); |
| #endif |
| } |
| |
| // Extend the handle scope making room for more handles. |
| static internal::Object** Extend(); |
| |
| // Zaps the handles in the half-open interval [start, end). |
| static void ZapRange(internal::Object** start, internal::Object** end); |
| |
| friend class v8::HandleScope; |
| friend class v8::ImplementationUtilities; |
| }; |
| |
| |
| // ---------------------------------------------------------------------------- |
| // Handle operations. |
| // They might invoke garbage collection. The result is an handle to |
| // an object of expected type, or the handle is an error if running out |
| // of space or encountering an internal error. |
| |
| void NormalizeProperties(Handle<JSObject> object, |
| PropertyNormalizationMode mode, |
| int expected_additional_properties); |
| void NormalizeElements(Handle<JSObject> object); |
| void TransformToFastProperties(Handle<JSObject> object, |
| int unused_property_fields); |
| |
| // Flattens a string. |
| void FlattenString(Handle<String> str); |
| |
| // Flattens a string and returns the underlying external or sequential |
| // string. |
| Handle<String> FlattenGetString(Handle<String> str); |
| |
| Handle<Object> SetProperty(Handle<JSObject> object, |
| Handle<String> key, |
| Handle<Object> value, |
| PropertyAttributes attributes); |
| |
| Handle<Object> SetProperty(Handle<Object> object, |
| Handle<Object> key, |
| Handle<Object> value, |
| PropertyAttributes attributes); |
| |
| Handle<Object> ForceSetProperty(Handle<JSObject> object, |
| Handle<Object> key, |
| Handle<Object> value, |
| PropertyAttributes attributes); |
| |
| Handle<Object> SetNormalizedProperty(Handle<JSObject> object, |
| Handle<String> key, |
| Handle<Object> value, |
| PropertyDetails details); |
| |
| Handle<Object> ForceDeleteProperty(Handle<JSObject> object, |
| Handle<Object> key); |
| |
| Handle<Object> IgnoreAttributesAndSetLocalProperty(Handle<JSObject> object, |
| Handle<String> key, |
| Handle<Object> value, |
| PropertyAttributes attributes); |
| |
| Handle<Object> SetPropertyWithInterceptor(Handle<JSObject> object, |
| Handle<String> key, |
| Handle<Object> value, |
| PropertyAttributes attributes); |
| |
| Handle<Object> SetElement(Handle<JSObject> object, |
| uint32_t index, |
| Handle<Object> value); |
| |
| Handle<Object> GetProperty(Handle<JSObject> obj, |
| const char* name); |
| |
| Handle<Object> GetProperty(Handle<Object> obj, |
| Handle<Object> key); |
| |
| Handle<Object> GetElement(Handle<Object> obj, |
| uint32_t index); |
| |
| Handle<Object> GetPropertyWithInterceptor(Handle<JSObject> receiver, |
| Handle<JSObject> holder, |
| Handle<String> name, |
| PropertyAttributes* attributes); |
| |
| Handle<Object> GetPrototype(Handle<Object> obj); |
| |
| Handle<Object> SetPrototype(Handle<JSObject> obj, Handle<Object> value); |
| |
| // Return the object's hidden properties object. If the object has no hidden |
| // properties and create_if_needed is true, then a new hidden property object |
| // will be allocated. Otherwise the Heap::undefined_value is returned. |
| Handle<Object> GetHiddenProperties(Handle<JSObject> obj, bool create_if_needed); |
| |
| Handle<Object> DeleteElement(Handle<JSObject> obj, uint32_t index); |
| Handle<Object> DeleteProperty(Handle<JSObject> obj, Handle<String> prop); |
| |
| Handle<Object> LookupSingleCharacterStringFromCode(uint32_t index); |
| |
| Handle<JSObject> Copy(Handle<JSObject> obj); |
| |
| Handle<Object> SetAccessor(Handle<JSObject> obj, Handle<AccessorInfo> info); |
| |
| Handle<FixedArray> AddKeysFromJSArray(Handle<FixedArray>, |
| Handle<JSArray> array); |
| |
| // Get the JS object corresponding to the given script; create it |
| // if none exists. |
| Handle<JSValue> GetScriptWrapper(Handle<Script> script); |
| |
| // Script line number computations. |
| void InitScriptLineEnds(Handle<Script> script); |
| // For string calculates an array of line end positions. If the string |
| // does not end with a new line character, this character may optionally be |
| // imagined. |
| Handle<FixedArray> CalculateLineEnds(Handle<String> string, |
| bool with_imaginary_last_new_line); |
| int GetScriptLineNumber(Handle<Script> script, int code_position); |
| // The safe version does not make heap allocations but may work much slower. |
| int GetScriptLineNumberSafe(Handle<Script> script, int code_position); |
| |
| // Computes the enumerable keys from interceptors. Used for debug mirrors and |
| // by GetKeysInFixedArrayFor below. |
| v8::Handle<v8::Array> GetKeysForNamedInterceptor(Handle<JSObject> receiver, |
| Handle<JSObject> object); |
| v8::Handle<v8::Array> GetKeysForIndexedInterceptor(Handle<JSObject> receiver, |
| Handle<JSObject> object); |
| |
| enum KeyCollectionType { LOCAL_ONLY, INCLUDE_PROTOS }; |
| |
| // Computes the enumerable keys for a JSObject. Used for implementing |
| // "for (n in object) { }". |
| Handle<FixedArray> GetKeysInFixedArrayFor(Handle<JSObject> object, |
| KeyCollectionType type); |
| Handle<JSArray> GetKeysFor(Handle<JSObject> object); |
| Handle<FixedArray> GetEnumPropertyKeys(Handle<JSObject> object, |
| bool cache_result); |
| |
| // Computes the union of keys and return the result. |
| // Used for implementing "for (n in object) { }" |
| Handle<FixedArray> UnionOfKeys(Handle<FixedArray> first, |
| Handle<FixedArray> second); |
| |
| Handle<String> SubString(Handle<String> str, |
| int start, |
| int end, |
| PretenureFlag pretenure = NOT_TENURED); |
| |
| |
| // Sets the expected number of properties for the function's instances. |
| void SetExpectedNofProperties(Handle<JSFunction> func, int nof); |
| |
| // Sets the prototype property for a function instance. |
| void SetPrototypeProperty(Handle<JSFunction> func, Handle<JSObject> value); |
| |
| // Sets the expected number of properties based on estimate from compiler. |
| void SetExpectedNofPropertiesFromEstimate(Handle<SharedFunctionInfo> shared, |
| int estimate); |
| |
| |
| Handle<JSGlobalProxy> ReinitializeJSGlobalProxy( |
| Handle<JSFunction> constructor, |
| Handle<JSGlobalProxy> global); |
| |
| Handle<Object> SetPrototype(Handle<JSFunction> function, |
| Handle<Object> prototype); |
| |
| |
| // Does lazy compilation of the given function. Returns true on success and |
| // false if the compilation resulted in a stack overflow. |
| enum ClearExceptionFlag { KEEP_EXCEPTION, CLEAR_EXCEPTION }; |
| |
| bool EnsureCompiled(Handle<SharedFunctionInfo> shared, |
| ClearExceptionFlag flag); |
| |
| bool CompileLazyShared(Handle<SharedFunctionInfo> shared, |
| ClearExceptionFlag flag); |
| |
| bool CompileLazy(Handle<JSFunction> function, |
| Handle<Object> receiver, |
| ClearExceptionFlag flag); |
| |
| bool CompileLazyInLoop(Handle<JSFunction> function, |
| Handle<Object> receiver, |
| ClearExceptionFlag flag); |
| |
| class NoHandleAllocation BASE_EMBEDDED { |
| public: |
| #ifndef DEBUG |
| NoHandleAllocation() {} |
| ~NoHandleAllocation() {} |
| #else |
| inline NoHandleAllocation(); |
| inline ~NoHandleAllocation(); |
| private: |
| int extensions_; |
| #endif |
| }; |
| |
| |
| // ---------------------------------------------------------------------------- |
| |
| |
| // Stack allocated wrapper call for optimizing adding multiple |
| // properties to an object. |
| class OptimizedObjectForAddingMultipleProperties BASE_EMBEDDED { |
| public: |
| OptimizedObjectForAddingMultipleProperties(Handle<JSObject> object, |
| int expected_property_count, |
| bool condition = true); |
| ~OptimizedObjectForAddingMultipleProperties(); |
| private: |
| bool has_been_transformed_; // Tells whether the object has been transformed. |
| int unused_property_fields_; // Captures the unused number of field. |
| Handle<JSObject> object_; // The object being optimized. |
| }; |
| |
| |
| } } // namespace v8::internal |
| |
| #endif // V8_HANDLES_H_ |
