// 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. #include "v8.h" #include "accessors.h" #include "api.h" #include "arguments.h" #include "bootstrapper.h" #include "compiler.h" #include "debug.h" #include "execution.h" #include "global-handles.h" #include "natives.h" #include "runtime.h" #include "string-search.h" #include "stub-cache.h" #include "vm-state-inl.h" namespace v8 { namespace internal { int HandleScope::NumberOfHandles(Isolate* isolate) { HandleScopeImplementer* impl = isolate->handle_scope_implementer(); int n = impl->blocks()->length(); if (n == 0) return 0; return ((n - 1) * kHandleBlockSize) + static_cast<int>( (isolate->handle_scope_data()->next - impl->blocks()->last())); } Object** HandleScope::Extend(Isolate* isolate) { v8::ImplementationUtilities::HandleScopeData* current = isolate->handle_scope_data(); Object** result = current->next; ASSERT(result == current->limit); // Make sure there's at least one scope on the stack and that the // top of the scope stack isn't a barrier. if (current->level == 0) { Utils::ReportApiFailure("v8::HandleScope::CreateHandle()", "Cannot create a handle without a HandleScope"); return NULL; } HandleScopeImplementer* impl = isolate->handle_scope_implementer(); // If there's more room in the last block, we use that. This is used // for fast creation of scopes after scope barriers. if (!impl->blocks()->is_empty()) { Object** limit = &impl->blocks()->last()[kHandleBlockSize]; if (current->limit != limit) { current->limit = limit; ASSERT(limit - current->next < kHandleBlockSize); } } // If we still haven't found a slot for the handle, we extend the // current handle scope by allocating a new handle block. if (result == current->limit) { // If there's a spare block, use it for growing the current scope. result = impl->GetSpareOrNewBlock(); // Add the extension to the global list of blocks, but count the // extension as part of the current scope. impl->blocks()->Add(result); current->limit = &result[kHandleBlockSize]; } return result; } void HandleScope::DeleteExtensions(Isolate* isolate) { v8::ImplementationUtilities::HandleScopeData* current = isolate->handle_scope_data(); isolate->handle_scope_implementer()->DeleteExtensions(current->limit); } #ifdef ENABLE_EXTRA_CHECKS void HandleScope::ZapRange(Object** start, Object** end) { ASSERT(end - start <= kHandleBlockSize); for (Object** p = start; p != end; p++) { *reinterpret_cast<Address*>(p) = v8::internal::kHandleZapValue; } } #endif Address HandleScope::current_level_address(Isolate* isolate) { return reinterpret_cast<Address>(&isolate->handle_scope_data()->level); } Address HandleScope::current_next_address(Isolate* isolate) { return reinterpret_cast<Address>(&isolate->handle_scope_data()->next); } Address HandleScope::current_limit_address(Isolate* isolate) { return reinterpret_cast<Address>(&isolate->handle_scope_data()->limit); } Handle<FixedArray> AddKeysFromJSArray(Handle<FixedArray> content, Handle<JSArray> array) { CALL_HEAP_FUNCTION(content->GetIsolate(), content->AddKeysFromJSArray(*array), FixedArray); } Handle<FixedArray> UnionOfKeys(Handle<FixedArray> first, Handle<FixedArray> second) { CALL_HEAP_FUNCTION(first->GetIsolate(), first->UnionOfKeys(*second), FixedArray); } Handle<JSGlobalProxy> ReinitializeJSGlobalProxy( Handle<JSFunction> constructor, Handle<JSGlobalProxy> global) { CALL_HEAP_FUNCTION( constructor->GetIsolate(), constructor->GetHeap()->ReinitializeJSGlobalProxy(*constructor, *global), JSGlobalProxy); } void SetExpectedNofProperties(Handle<JSFunction> func, int nof) { // If objects constructed from this function exist then changing // 'estimated_nof_properties' is dangerous since the previous value might // have been compiled into the fast construct stub. More over, the inobject // slack tracking logic might have adjusted the previous value, so even // passing the same value is risky. if (func->shared()->live_objects_may_exist()) return; func->shared()->set_expected_nof_properties(nof); if (func->has_initial_map()) { Handle<Map> new_initial_map = func->GetIsolate()->factory()->CopyMap( Handle<Map>(func->initial_map())); new_initial_map->set_unused_property_fields(nof); func->set_initial_map(*new_initial_map); } } void SetPrototypeProperty(Handle<JSFunction> func, Handle<JSObject> value) { CALL_HEAP_FUNCTION_VOID(func->GetIsolate(), func->SetPrototype(*value)); } static int ExpectedNofPropertiesFromEstimate(int estimate) { // If no properties are added in the constructor, they are more likely // to be added later. if (estimate == 0) estimate = 2; // We do not shrink objects that go into a snapshot (yet), so we adjust // the estimate conservatively. if (Serializer::enabled()) return estimate + 2; // Inobject slack tracking will reclaim redundant inobject space later, // so we can afford to adjust the estimate generously. if (FLAG_clever_optimizations) { return estimate + 8; } else { return estimate + 3; } } void SetExpectedNofPropertiesFromEstimate(Handle<SharedFunctionInfo> shared, int estimate) { // See the comment in SetExpectedNofProperties. if (shared->live_objects_may_exist()) return; shared->set_expected_nof_properties( ExpectedNofPropertiesFromEstimate(estimate)); } void FlattenString(Handle<String> string) { CALL_HEAP_FUNCTION_VOID(string->GetIsolate(), string->TryFlatten()); } Handle<String> FlattenGetString(Handle<String> string) { CALL_HEAP_FUNCTION(string->GetIsolate(), string->TryFlatten(), String); } Handle<Object> SetPrototype(Handle<JSFunction> function, Handle<Object> prototype) { ASSERT(function->should_have_prototype()); CALL_HEAP_FUNCTION(function->GetIsolate(), Accessors::FunctionSetPrototype(*function, *prototype, NULL), Object); } Handle<Object> SetProperty(Isolate* isolate, Handle<Object> object, Handle<Object> key, Handle<Object> value, PropertyAttributes attributes, StrictModeFlag strict_mode) { CALL_HEAP_FUNCTION( isolate, Runtime::SetObjectProperty( isolate, object, key, value, attributes, strict_mode), Object); } Handle<Object> ForceSetProperty(Handle<JSObject> object, Handle<Object> key, Handle<Object> value, PropertyAttributes attributes) { Isolate* isolate = object->GetIsolate(); CALL_HEAP_FUNCTION( isolate, Runtime::ForceSetObjectProperty( isolate, object, key, value, attributes), Object); } Handle<Object> DeleteProperty(Handle<JSObject> object, Handle<Object> key) { Isolate* isolate = object->GetIsolate(); CALL_HEAP_FUNCTION(isolate, Runtime::DeleteObjectProperty( isolate, object, key, JSReceiver::NORMAL_DELETION), Object); } Handle<Object> ForceDeleteProperty(Handle<JSObject> object, Handle<Object> key) { Isolate* isolate = object->GetIsolate(); CALL_HEAP_FUNCTION(isolate, Runtime::DeleteObjectProperty( isolate, object, key, JSReceiver::FORCE_DELETION), Object); } Handle<Object> HasProperty(Handle<JSReceiver> obj, Handle<Object> key) { Isolate* isolate = obj->GetIsolate(); CALL_HEAP_FUNCTION(isolate, Runtime::HasObjectProperty(isolate, obj, key), Object); } Handle<Object> GetProperty(Handle<JSReceiver> obj, const char* name) { Isolate* isolate = obj->GetIsolate(); Handle<String> str = isolate->factory()->InternalizeUtf8String(name); CALL_HEAP_FUNCTION(isolate, obj->GetProperty(*str), Object); } Handle<Object> GetProperty(Isolate* isolate, Handle<Object> obj, Handle<Object> key) { CALL_HEAP_FUNCTION(isolate, Runtime::GetObjectProperty(isolate, obj, key), Object); } Handle<Object> SetPrototype(Handle<JSObject> obj, Handle<Object> value) { const bool skip_hidden_prototypes = false; CALL_HEAP_FUNCTION(obj->GetIsolate(), obj->SetPrototype(*value, skip_hidden_prototypes), Object); } Handle<Object> LookupSingleCharacterStringFromCode(Isolate* isolate, uint32_t index) { CALL_HEAP_FUNCTION( isolate, isolate->heap()->LookupSingleCharacterStringFromCode(index), Object); } Handle<String> SubString(Handle<String> str, int start, int end, PretenureFlag pretenure) { CALL_HEAP_FUNCTION(str->GetIsolate(), str->SubString(start, end, pretenure), String); } Handle<JSObject> Copy(Handle<JSObject> obj) { Isolate* isolate = obj->GetIsolate(); CALL_HEAP_FUNCTION(isolate, isolate->heap()->CopyJSObject(*obj), JSObject); } Handle<JSObject> DeepCopy(Handle<JSObject> obj) { Isolate* isolate = obj->GetIsolate(); CALL_HEAP_FUNCTION(isolate, obj->DeepCopy(isolate), JSObject); } Handle<Object> SetAccessor(Handle<JSObject> obj, Handle<AccessorInfo> info) { CALL_HEAP_FUNCTION(obj->GetIsolate(), obj->DefineAccessor(*info), Object); } // Wrappers for scripts are kept alive and cached in weak global // handles referred from foreign objects held by the scripts as long as // they are used. When they are not used anymore, the garbage // collector will call the weak callback on the global handle // associated with the wrapper and get rid of both the wrapper and the // handle. static void ClearWrapperCache(v8::Isolate* v8_isolate, Persistent<v8::Value> handle, void*) { Handle<Object> cache = Utils::OpenHandle(*handle); JSValue* wrapper = JSValue::cast(*cache); Foreign* foreign = Script::cast(wrapper->value())->wrapper(); ASSERT(foreign->foreign_address() == reinterpret_cast<Address>(cache.location())); foreign->set_foreign_address(0); Isolate* isolate = reinterpret_cast<Isolate*>(v8_isolate); isolate->global_handles()->Destroy(cache.location()); isolate->counters()->script_wrappers()->Decrement(); } Handle<JSValue> GetScriptWrapper(Handle<Script> script) { if (script->wrapper()->foreign_address() != NULL) { // Return the script wrapper directly from the cache. return Handle<JSValue>( reinterpret_cast<JSValue**>(script->wrapper()->foreign_address())); } Isolate* isolate = script->GetIsolate(); // Construct a new script wrapper. isolate->counters()->script_wrappers()->Increment(); Handle<JSFunction> constructor = isolate->script_function(); Handle<JSValue> result = Handle<JSValue>::cast(isolate->factory()->NewJSObject(constructor)); // The allocation might have triggered a GC, which could have called this // function recursively, and a wrapper has already been created and cached. // In that case, simply return the cached wrapper. if (script->wrapper()->foreign_address() != NULL) { return Handle<JSValue>( reinterpret_cast<JSValue**>(script->wrapper()->foreign_address())); } result->set_value(*script); // Create a new weak global handle and use it to cache the wrapper // for future use. The cache will automatically be cleared by the // garbage collector when it is not used anymore. Handle<Object> handle = isolate->global_handles()->Create(*result); isolate->global_handles()->MakeWeak(handle.location(), NULL, NULL, &ClearWrapperCache); script->wrapper()->set_foreign_address( reinterpret_cast<Address>(handle.location())); return result; } // Init line_ends array with code positions of line ends inside script // source. void InitScriptLineEnds(Handle<Script> script) { if (!script->line_ends()->IsUndefined()) return; Isolate* isolate = script->GetIsolate(); if (!script->source()->IsString()) { ASSERT(script->source()->IsUndefined()); Handle<FixedArray> empty = isolate->factory()->NewFixedArray(0); script->set_line_ends(*empty); ASSERT(script->line_ends()->IsFixedArray()); return; } Handle<String> src(String::cast(script->source()), isolate); Handle<FixedArray> array = CalculateLineEnds(src, true); if (*array != isolate->heap()->empty_fixed_array()) { array->set_map(isolate->heap()->fixed_cow_array_map()); } script->set_line_ends(*array); ASSERT(script->line_ends()->IsFixedArray()); } template <typename SourceChar> static void CalculateLineEnds(Isolate* isolate, List<int>* line_ends, Vector<const SourceChar> src, bool with_last_line) { const int src_len = src.length(); StringSearch<uint8_t, SourceChar> search(isolate, STATIC_ASCII_VECTOR("\n")); // Find and record line ends. int position = 0; while (position != -1 && position < src_len) { position = search.Search(src, position); if (position != -1) { line_ends->Add(position); position++; } else if (with_last_line) { // Even if the last line misses a line end, it is counted. line_ends->Add(src_len); return; } } } Handle<FixedArray> CalculateLineEnds(Handle<String> src, bool with_last_line) { src = FlattenGetString(src); // Rough estimate of line count based on a roughly estimated average // length of (unpacked) code. int line_count_estimate = src->length() >> 4; List<int> line_ends(line_count_estimate); Isolate* isolate = src->GetIsolate(); { AssertNoAllocation no_heap_allocation; // ensure vectors stay valid. // Dispatch on type of strings. String::FlatContent content = src->GetFlatContent(); ASSERT(content.IsFlat()); if (content.IsAscii()) { CalculateLineEnds(isolate, &line_ends, content.ToOneByteVector(), with_last_line); } else { CalculateLineEnds(isolate, &line_ends, content.ToUC16Vector(), with_last_line); } } int line_count = line_ends.length(); Handle<FixedArray> array = isolate->factory()->NewFixedArray(line_count); for (int i = 0; i < line_count; i++) { array->set(i, Smi::FromInt(line_ends[i])); } return array; } // Convert code position into line number. int GetScriptLineNumber(Handle<Script> script, int code_pos) { InitScriptLineEnds(script); AssertNoAllocation no_allocation; FixedArray* line_ends_array = FixedArray::cast(script->line_ends()); const int line_ends_len = line_ends_array->length(); if (!line_ends_len) return -1; if ((Smi::cast(line_ends_array->get(0)))->value() >= code_pos) { return script->line_offset()->value(); } int left = 0; int right = line_ends_len; while (int half = (right - left) / 2) { if ((Smi::cast(line_ends_array->get(left + half)))->value() > code_pos) { right -= half; } else { left += half; } } return right + script->line_offset()->value(); } // Convert code position into column number. int GetScriptColumnNumber(Handle<Script> script, int code_pos) { int line_number = GetScriptLineNumber(script, code_pos); if (line_number == -1) return -1; AssertNoAllocation no_allocation; FixedArray* line_ends_array = FixedArray::cast(script->line_ends()); line_number = line_number - script->line_offset()->value(); if (line_number == 0) return code_pos + script->column_offset()->value(); int prev_line_end_pos = Smi::cast(line_ends_array->get(line_number - 1))->value(); return code_pos - (prev_line_end_pos + 1); } int GetScriptLineNumberSafe(Handle<Script> script, int code_pos) { AssertNoAllocation no_allocation; if (!script->line_ends()->IsUndefined()) { return GetScriptLineNumber(script, code_pos); } // Slow mode: we do not have line_ends. We have to iterate through source. if (!script->source()->IsString()) { return -1; } String* source = String::cast(script->source()); int line = 0; int len = source->length(); for (int pos = 0; pos < len; pos++) { if (pos == code_pos) { break; } if (source->Get(pos) == '\n') { line++; } } return line; } void CustomArguments::IterateInstance(ObjectVisitor* v) { v->VisitPointers(values_, values_ + ARRAY_SIZE(values_)); } // Compute the property keys from the interceptor. // TODO(rossberg): support symbols in API, and filter here if needed. v8::Handle<v8::Array> GetKeysForNamedInterceptor(Handle<JSReceiver> receiver, Handle<JSObject> object) { Isolate* isolate = receiver->GetIsolate(); Handle<InterceptorInfo> interceptor(object->GetNamedInterceptor()); CustomArguments args(isolate, interceptor->data(), *receiver, *object); v8::AccessorInfo info(args.end()); v8::Handle<v8::Array> result; if (!interceptor->enumerator()->IsUndefined()) { v8::NamedPropertyEnumerator enum_fun = v8::ToCData<v8::NamedPropertyEnumerator>(interceptor->enumerator()); LOG(isolate, ApiObjectAccess("interceptor-named-enum", *object)); { // Leaving JavaScript. VMState state(isolate, EXTERNAL); result = enum_fun(info); } } #if ENABLE_EXTRA_CHECKS CHECK(result.IsEmpty() || v8::Utils::OpenHandle(*result)->IsJSObject()); #endif return result; } // Compute the element keys from the interceptor. v8::Handle<v8::Array> GetKeysForIndexedInterceptor(Handle<JSReceiver> receiver, Handle<JSObject> object) { Isolate* isolate = receiver->GetIsolate(); Handle<InterceptorInfo> interceptor(object->GetIndexedInterceptor()); CustomArguments args(isolate, interceptor->data(), *receiver, *object); v8::AccessorInfo info(args.end()); v8::Handle<v8::Array> result; if (!interceptor->enumerator()->IsUndefined()) { v8::IndexedPropertyEnumerator enum_fun = v8::ToCData<v8::IndexedPropertyEnumerator>(interceptor->enumerator()); LOG(isolate, ApiObjectAccess("interceptor-indexed-enum", *object)); { // Leaving JavaScript. VMState state(isolate, EXTERNAL); result = enum_fun(info); #if ENABLE_EXTRA_CHECKS CHECK(result.IsEmpty() || v8::Utils::OpenHandle(*result)->IsJSObject()); #endif } } return result; } Handle<Object> GetScriptNameOrSourceURL(Handle<Script> script) { Isolate* isolate = script->GetIsolate(); Handle<String> name_or_source_url_key = isolate->factory()->InternalizeOneByteString( STATIC_ASCII_VECTOR("nameOrSourceURL")); Handle<JSValue> script_wrapper = GetScriptWrapper(script); Handle<Object> property = GetProperty(isolate, script_wrapper, name_or_source_url_key); ASSERT(property->IsJSFunction()); Handle<JSFunction> method = Handle<JSFunction>::cast(property); bool caught_exception; Handle<Object> result = Execution::TryCall(method, script_wrapper, 0, NULL, &caught_exception); if (caught_exception) { result = isolate->factory()->undefined_value(); } return result; } static bool ContainsOnlyValidKeys(Handle<FixedArray> array) { int len = array->length(); for (int i = 0; i < len; i++) { Object* e = array->get(i); if (!(e->IsString() || e->IsNumber())) return false; } return true; } Handle<FixedArray> GetKeysInFixedArrayFor(Handle<JSReceiver> object, KeyCollectionType type, bool* threw) { USE(ContainsOnlyValidKeys); Isolate* isolate = object->GetIsolate(); Handle<FixedArray> content = isolate->factory()->empty_fixed_array(); Handle<JSObject> arguments_boilerplate = Handle<JSObject>( isolate->context()->native_context()->arguments_boilerplate(), isolate); Handle<JSFunction> arguments_function = Handle<JSFunction>( JSFunction::cast(arguments_boilerplate->map()->constructor()), isolate); // Only collect keys if access is permitted. for (Handle<Object> p = object; *p != isolate->heap()->null_value(); p = Handle<Object>(p->GetPrototype(isolate), isolate)) { if (p->IsJSProxy()) { Handle<JSProxy> proxy(JSProxy::cast(*p), isolate); Handle<Object> args[] = { proxy }; Handle<Object> names = Execution::Call( isolate->proxy_enumerate(), object, ARRAY_SIZE(args), args, threw); if (*threw) return content; content = AddKeysFromJSArray(content, Handle<JSArray>::cast(names)); break; } Handle<JSObject> current(JSObject::cast(*p), isolate); // Check access rights if required. if (current->IsAccessCheckNeeded() && !isolate->MayNamedAccess(*current, isolate->heap()->undefined_value(), v8::ACCESS_KEYS)) { isolate->ReportFailedAccessCheck(*current, v8::ACCESS_KEYS); break; } // Compute the element keys. Handle<FixedArray> element_keys = isolate->factory()->NewFixedArray(current->NumberOfEnumElements()); current->GetEnumElementKeys(*element_keys); content = UnionOfKeys(content, element_keys); ASSERT(ContainsOnlyValidKeys(content)); // Add the element keys from the interceptor. if (current->HasIndexedInterceptor()) { v8::Handle<v8::Array> result = GetKeysForIndexedInterceptor(object, current); if (!result.IsEmpty()) content = AddKeysFromJSArray(content, v8::Utils::OpenHandle(*result)); ASSERT(ContainsOnlyValidKeys(content)); } // We can cache the computed property keys if access checks are // not needed and no interceptors are involved. // // We do not use the cache if the object has elements and // therefore it does not make sense to cache the property names // for arguments objects. Arguments objects will always have // elements. // Wrapped strings have elements, but don't have an elements // array or dictionary. So the fast inline test for whether to // use the cache says yes, so we should not create a cache. bool cache_enum_keys = ((current->map()->constructor() != *arguments_function) && !current->IsJSValue() && !current->IsAccessCheckNeeded() && !current->HasNamedInterceptor() && !current->HasIndexedInterceptor()); // Compute the property keys and cache them if possible. content = UnionOfKeys(content, GetEnumPropertyKeys(current, cache_enum_keys)); ASSERT(ContainsOnlyValidKeys(content)); // Add the property keys from the interceptor. if (current->HasNamedInterceptor()) { v8::Handle<v8::Array> result = GetKeysForNamedInterceptor(object, current); if (!result.IsEmpty()) content = AddKeysFromJSArray(content, v8::Utils::OpenHandle(*result)); ASSERT(ContainsOnlyValidKeys(content)); } // If we only want local properties we bail out after the first // iteration. if (type == LOCAL_ONLY) break; } return content; } Handle<JSArray> GetKeysFor(Handle<JSReceiver> object, bool* threw) { Isolate* isolate = object->GetIsolate(); isolate->counters()->for_in()->Increment(); Handle<FixedArray> elements = GetKeysInFixedArrayFor(object, INCLUDE_PROTOS, threw); return isolate->factory()->NewJSArrayWithElements(elements); } Handle<FixedArray> ReduceFixedArrayTo(Handle<FixedArray> array, int length) { ASSERT(array->length() >= length); if (array->length() == length) return array; Handle<FixedArray> new_array = array->GetIsolate()->factory()->NewFixedArray(length); for (int i = 0; i < length; ++i) new_array->set(i, array->get(i)); return new_array; } Handle<FixedArray> GetEnumPropertyKeys(Handle<JSObject> object, bool cache_result) { Isolate* isolate = object->GetIsolate(); if (object->HasFastProperties()) { if (object->map()->instance_descriptors()->HasEnumCache()) { int own_property_count = object->map()->EnumLength(); // If we have an enum cache, but the enum length of the given map is set // to kInvalidEnumCache, this means that the map itself has never used the // present enum cache. The first step to using the cache is to set the // enum length of the map by counting the number of own descriptors that // are not DONT_ENUM or SYMBOLIC. if (own_property_count == Map::kInvalidEnumCache) { own_property_count = object->map()->NumberOfDescribedProperties( OWN_DESCRIPTORS, DONT_SHOW); if (cache_result) object->map()->SetEnumLength(own_property_count); } DescriptorArray* desc = object->map()->instance_descriptors(); Handle<FixedArray> keys(desc->GetEnumCache(), isolate); // In case the number of properties required in the enum are actually // present, we can reuse the enum cache. Otherwise, this means that the // enum cache was generated for a previous (smaller) version of the // Descriptor Array. In that case we regenerate the enum cache. if (own_property_count <= keys->length()) { isolate->counters()->enum_cache_hits()->Increment(); return ReduceFixedArrayTo(keys, own_property_count); } } Handle<Map> map(object->map()); if (map->instance_descriptors()->IsEmpty()) { isolate->counters()->enum_cache_hits()->Increment(); if (cache_result) map->SetEnumLength(0); return isolate->factory()->empty_fixed_array(); } isolate->counters()->enum_cache_misses()->Increment(); int num_enum = map->NumberOfDescribedProperties(ALL_DESCRIPTORS, DONT_SHOW); Handle<FixedArray> storage = isolate->factory()->NewFixedArray(num_enum); Handle<FixedArray> indices = isolate->factory()->NewFixedArray(num_enum); Handle<DescriptorArray> descs = Handle<DescriptorArray>(object->map()->instance_descriptors(), isolate); int real_size = map->NumberOfOwnDescriptors(); int enum_size = 0; int index = 0; for (int i = 0; i < descs->number_of_descriptors(); i++) { PropertyDetails details = descs->GetDetails(i); Object* key = descs->GetKey(i); if (!(details.IsDontEnum() || key->IsSymbol())) { if (i < real_size) ++enum_size; storage->set(index, key); if (!indices.is_null()) { if (details.type() != FIELD) { indices = Handle<FixedArray>(); } else { int field_index = Descriptor::IndexFromValue(descs->GetValue(i)); if (field_index >= map->inobject_properties()) { field_index = -(field_index - map->inobject_properties() + 1); } indices->set(index, Smi::FromInt(field_index)); } } index++; } } ASSERT(index == storage->length()); Handle<FixedArray> bridge_storage = isolate->factory()->NewFixedArray( DescriptorArray::kEnumCacheBridgeLength); DescriptorArray* desc = object->map()->instance_descriptors(); desc->SetEnumCache(*bridge_storage, *storage, indices.is_null() ? Object::cast(Smi::FromInt(0)) : Object::cast(*indices)); if (cache_result) { object->map()->SetEnumLength(enum_size); } return ReduceFixedArrayTo(storage, enum_size); } else { Handle<NameDictionary> dictionary(object->property_dictionary()); int length = dictionary->NumberOfElements(); if (length == 0) { return Handle<FixedArray>(isolate->heap()->empty_fixed_array()); } // The enumeration array is generated by allocating an array big enough to // hold all properties that have been seen, whether they are are deleted or // not. Subsequently all visible properties are added to the array. If some // properties were not visible, the array is trimmed so it only contains // visible properties. This improves over adding elements and sorting by // index by having linear complexity rather than n*log(n). // By comparing the monotonous NextEnumerationIndex to the NumberOfElements, // we can predict the number of holes in the final array. If there will be // more than 50% holes, regenerate the enumeration indices to reduce the // number of holes to a minimum. This avoids allocating a large array if // many properties were added but subsequently deleted. int next_enumeration = dictionary->NextEnumerationIndex(); if (!object->IsGlobalObject() && next_enumeration > (length * 3) / 2) { NameDictionary::DoGenerateNewEnumerationIndices(dictionary); next_enumeration = dictionary->NextEnumerationIndex(); } Handle<FixedArray> storage = isolate->factory()->NewFixedArray(next_enumeration); storage = Handle<FixedArray>(dictionary->CopyEnumKeysTo(*storage)); ASSERT(storage->length() == object->NumberOfLocalProperties(DONT_SHOW)); return storage; } } Handle<ObjectHashSet> ObjectHashSetAdd(Handle<ObjectHashSet> table, Handle<Object> key) { CALL_HEAP_FUNCTION(table->GetIsolate(), table->Add(*key), ObjectHashSet); } Handle<ObjectHashSet> ObjectHashSetRemove(Handle<ObjectHashSet> table, Handle<Object> key) { CALL_HEAP_FUNCTION(table->GetIsolate(), table->Remove(*key), ObjectHashSet); } Handle<ObjectHashTable> PutIntoObjectHashTable(Handle<ObjectHashTable> table, Handle<Object> key, Handle<Object> value) { CALL_HEAP_FUNCTION(table->GetIsolate(), table->Put(*key, *value), ObjectHashTable); } DeferredHandleScope::DeferredHandleScope(Isolate* isolate) : impl_(isolate->handle_scope_implementer()) { impl_->BeginDeferredScope(); v8::ImplementationUtilities::HandleScopeData* data = impl_->isolate()->handle_scope_data(); Object** new_next = impl_->GetSpareOrNewBlock(); Object** new_limit = &new_next[kHandleBlockSize]; ASSERT(data->limit == &impl_->blocks()->last()[kHandleBlockSize]); impl_->blocks()->Add(new_next); #ifdef DEBUG prev_level_ = data->level; #endif data->level++; prev_limit_ = data->limit; prev_next_ = data->next; data->next = new_next; data->limit = new_limit; } DeferredHandleScope::~DeferredHandleScope() { impl_->isolate()->handle_scope_data()->level--; ASSERT(handles_detached_); ASSERT(impl_->isolate()->handle_scope_data()->level == prev_level_); } DeferredHandles* DeferredHandleScope::Detach() { DeferredHandles* deferred = impl_->Detach(prev_limit_); v8::ImplementationUtilities::HandleScopeData* data = impl_->isolate()->handle_scope_data(); data->next = prev_next_; data->limit = prev_limit_; #ifdef DEBUG handles_detached_ = true; #endif return deferred; } } } // namespace v8::internal