/* * Copyright (C) 2006-2019 Apple Inc. All rights reserved. * Copyright (C) 2007 Eric Seidel * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. 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. * * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``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 APPLE INC. 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 "APICast.h" #include "Error.h" #include "ExceptionHelpers.h" #include "JSCallbackFunction.h" #include "JSClassRef.h" #include "JSFunction.h" #include "JSGlobalObject.h" #include "JSLock.h" #include "JSObjectRef.h" #include "JSString.h" #include "OpaqueJSString.h" #include "PropertyNameArray.h" #include namespace JSC { template inline JSCallbackObject* JSCallbackObject::asCallbackObject(JSValue value) { ASSERT(asObject(value)->inherits(value.getObject()->vm(), info())); return jsCast(asObject(value)); } template inline JSCallbackObject* JSCallbackObject::asCallbackObject(EncodedJSValue encodedValue) { JSValue value = JSValue::decode(encodedValue); ASSERT(asObject(value)->inherits(value.getObject()->vm(), info())); return jsCast(asObject(value)); } template JSCallbackObject::JSCallbackObject(ExecState* exec, Structure* structure, JSClassRef jsClass, void* data) : Parent(exec->vm(), structure) , m_callbackObjectData(makeUnique(data, jsClass)) { } // Global object constructor. // FIXME: Move this into a separate JSGlobalCallbackObject class derived from this one. template JSCallbackObject::JSCallbackObject(VM& vm, JSClassRef jsClass, Structure* structure) : Parent(vm, structure) , m_callbackObjectData(makeUnique(nullptr, jsClass)) { } template JSCallbackObject::~JSCallbackObject() { VM& vm = this->HeapCell::vm(); vm.currentlyDestructingCallbackObject = this; ASSERT(m_classInfo); vm.currentlyDestructingCallbackObjectClassInfo = m_classInfo; JSObjectRef thisRef = toRef(static_cast(this)); for (JSClassRef jsClass = classRef(); jsClass; jsClass = jsClass->parentClass) { if (JSObjectFinalizeCallback finalize = jsClass->finalize) finalize(thisRef); } vm.currentlyDestructingCallbackObject = nullptr; vm.currentlyDestructingCallbackObjectClassInfo = nullptr; } template void JSCallbackObject::finishCreation(ExecState* exec) { VM& vm = exec->vm(); Base::finishCreation(vm); ASSERT(Parent::inherits(vm, info())); init(exec); } // This is just for Global object, so we can assume that Base::finishCreation is JSGlobalObject::finishCreation. template void JSCallbackObject::finishCreation(VM& vm) { ASSERT(Parent::inherits(vm, info())); ASSERT(Parent::isGlobalObject()); Base::finishCreation(vm); init(jsCast(this)->globalExec()); } template void JSCallbackObject::init(ExecState* exec) { ASSERT(exec); Vector initRoutines; JSClassRef jsClass = classRef(); do { if (JSObjectInitializeCallback initialize = jsClass->initialize) initRoutines.append(initialize); } while ((jsClass = jsClass->parentClass)); // initialize from base to derived for (int i = static_cast(initRoutines.size()) - 1; i >= 0; i--) { JSLock::DropAllLocks dropAllLocks(exec); JSObjectInitializeCallback initialize = initRoutines[i]; initialize(toRef(exec), toRef(this)); } m_classInfo = this->classInfo(); } template String JSCallbackObject::className(const JSObject* object, VM& vm) { const JSCallbackObject* thisObject = jsCast(object); String thisClassName = thisObject->classRef()->className(); if (!thisClassName.isEmpty()) return thisClassName; return Parent::className(object, vm); } template String JSCallbackObject::toStringName(const JSObject* object, ExecState* exec) { VM& vm = exec->vm(); const ClassInfo* info = object->classInfo(vm); ASSERT(info); return info->methodTable.className(object, vm); } template bool JSCallbackObject::getOwnPropertySlot(JSObject* object, ExecState* exec, PropertyName propertyName, PropertySlot& slot) { VM& vm = exec->vm(); auto scope = DECLARE_THROW_SCOPE(vm); JSCallbackObject* thisObject = jsCast(object); JSContextRef ctx = toRef(exec); JSObjectRef thisRef = toRef(thisObject); RefPtr propertyNameRef; if (StringImpl* name = propertyName.uid()) { for (JSClassRef jsClass = thisObject->classRef(); jsClass; jsClass = jsClass->parentClass) { // optional optimization to bypass getProperty in cases when we only need to know if the property exists if (JSObjectHasPropertyCallback hasProperty = jsClass->hasProperty) { if (!propertyNameRef) propertyNameRef = OpaqueJSString::tryCreate(name); JSLock::DropAllLocks dropAllLocks(exec); if (hasProperty(ctx, thisRef, propertyNameRef.get())) { slot.setCustom(thisObject, PropertyAttribute::ReadOnly | PropertyAttribute::DontEnum, callbackGetter); return true; } } else if (JSObjectGetPropertyCallback getProperty = jsClass->getProperty) { if (!propertyNameRef) propertyNameRef = OpaqueJSString::tryCreate(name); JSValueRef exception = 0; JSValueRef value; { JSLock::DropAllLocks dropAllLocks(exec); value = getProperty(ctx, thisRef, propertyNameRef.get(), &exception); } if (exception) { throwException(exec, scope, toJS(exec, exception)); slot.setValue(thisObject, PropertyAttribute::ReadOnly | PropertyAttribute::DontEnum, jsUndefined()); return true; } if (value) { slot.setValue(thisObject, PropertyAttribute::ReadOnly | PropertyAttribute::DontEnum, toJS(exec, value)); return true; } } if (OpaqueJSClassStaticValuesTable* staticValues = jsClass->staticValues(exec)) { if (staticValues->contains(name)) { JSValue value = thisObject->getStaticValue(exec, propertyName); if (value) { slot.setValue(thisObject, PropertyAttribute::ReadOnly | PropertyAttribute::DontEnum, value); return true; } } } if (OpaqueJSClassStaticFunctionsTable* staticFunctions = jsClass->staticFunctions(exec)) { if (staticFunctions->contains(name)) { slot.setCustom(thisObject, PropertyAttribute::ReadOnly | PropertyAttribute::DontEnum, staticFunctionGetter); return true; } } } } return Parent::getOwnPropertySlot(thisObject, exec, propertyName, slot); } template bool JSCallbackObject::getOwnPropertySlotByIndex(JSObject* object, ExecState* exec, unsigned propertyName, PropertySlot& slot) { VM& vm = exec->vm(); return object->methodTable(vm)->getOwnPropertySlot(object, exec, Identifier::from(vm, propertyName), slot); } template JSValue JSCallbackObject::defaultValue(const JSObject* object, ExecState* exec, PreferredPrimitiveType hint) { VM& vm = exec->vm(); auto scope = DECLARE_THROW_SCOPE(vm); const JSCallbackObject* thisObject = jsCast(object); JSContextRef ctx = toRef(exec); JSObjectRef thisRef = toRef(thisObject); ::JSType jsHint = hint == PreferString ? kJSTypeString : kJSTypeNumber; for (JSClassRef jsClass = thisObject->classRef(); jsClass; jsClass = jsClass->parentClass) { if (JSObjectConvertToTypeCallback convertToType = jsClass->convertToType) { JSValueRef exception = 0; JSValueRef result = convertToType(ctx, thisRef, jsHint, &exception); if (exception) { throwException(exec, scope, toJS(exec, exception)); return jsUndefined(); } if (result) return toJS(exec, result); } } return Parent::defaultValue(object, exec, hint); } template bool JSCallbackObject::put(JSCell* cell, ExecState* exec, PropertyName propertyName, JSValue value, PutPropertySlot& slot) { VM& vm = exec->vm(); auto scope = DECLARE_THROW_SCOPE(vm); JSCallbackObject* thisObject = jsCast(cell); JSContextRef ctx = toRef(exec); JSObjectRef thisRef = toRef(thisObject); RefPtr propertyNameRef; JSValueRef valueRef = toRef(exec, value); if (StringImpl* name = propertyName.uid()) { for (JSClassRef jsClass = thisObject->classRef(); jsClass; jsClass = jsClass->parentClass) { if (JSObjectSetPropertyCallback setProperty = jsClass->setProperty) { if (!propertyNameRef) propertyNameRef = OpaqueJSString::tryCreate(name); JSValueRef exception = 0; bool result; { JSLock::DropAllLocks dropAllLocks(exec); result = setProperty(ctx, thisRef, propertyNameRef.get(), valueRef, &exception); } if (exception) throwException(exec, scope, toJS(exec, exception)); if (result || exception) return result; } if (OpaqueJSClassStaticValuesTable* staticValues = jsClass->staticValues(exec)) { if (StaticValueEntry* entry = staticValues->get(name)) { if (entry->attributes & kJSPropertyAttributeReadOnly) return false; if (JSObjectSetPropertyCallback setProperty = entry->setProperty) { JSValueRef exception = 0; bool result; { JSLock::DropAllLocks dropAllLocks(exec); result = setProperty(ctx, thisRef, entry->propertyNameRef.get(), valueRef, &exception); } if (exception) throwException(exec, scope, toJS(exec, exception)); if (result || exception) return result; } } } if (OpaqueJSClassStaticFunctionsTable* staticFunctions = jsClass->staticFunctions(exec)) { if (StaticFunctionEntry* entry = staticFunctions->get(name)) { PropertySlot getSlot(thisObject, PropertySlot::InternalMethodType::VMInquiry); if (Parent::getOwnPropertySlot(thisObject, exec, propertyName, getSlot)) return Parent::put(thisObject, exec, propertyName, value, slot); if (entry->attributes & kJSPropertyAttributeReadOnly) return false; return thisObject->JSCallbackObject::putDirect(vm, propertyName, value); // put as override property } } } } return Parent::put(thisObject, exec, propertyName, value, slot); } template bool JSCallbackObject::putByIndex(JSCell* cell, ExecState* exec, unsigned propertyIndex, JSValue value, bool shouldThrow) { VM& vm = exec->vm(); auto scope = DECLARE_THROW_SCOPE(vm); JSCallbackObject* thisObject = jsCast(cell); JSContextRef ctx = toRef(exec); JSObjectRef thisRef = toRef(thisObject); RefPtr propertyNameRef; JSValueRef valueRef = toRef(exec, value); Identifier propertyName = Identifier::from(vm, propertyIndex); for (JSClassRef jsClass = thisObject->classRef(); jsClass; jsClass = jsClass->parentClass) { if (JSObjectSetPropertyCallback setProperty = jsClass->setProperty) { if (!propertyNameRef) propertyNameRef = OpaqueJSString::tryCreate(propertyName.impl()); JSValueRef exception = 0; bool result; { JSLock::DropAllLocks dropAllLocks(exec); result = setProperty(ctx, thisRef, propertyNameRef.get(), valueRef, &exception); } if (exception) throwException(exec, scope, toJS(exec, exception)); if (result || exception) return result; } if (OpaqueJSClassStaticValuesTable* staticValues = jsClass->staticValues(exec)) { if (StaticValueEntry* entry = staticValues->get(propertyName.impl())) { if (entry->attributes & kJSPropertyAttributeReadOnly) return false; if (JSObjectSetPropertyCallback setProperty = entry->setProperty) { JSValueRef exception = 0; bool result; { JSLock::DropAllLocks dropAllLocks(exec); result = setProperty(ctx, thisRef, entry->propertyNameRef.get(), valueRef, &exception); } if (exception) throwException(exec, scope, toJS(exec, exception)); if (result || exception) return result; } } } if (OpaqueJSClassStaticFunctionsTable* staticFunctions = jsClass->staticFunctions(exec)) { if (StaticFunctionEntry* entry = staticFunctions->get(propertyName.impl())) { if (entry->attributes & kJSPropertyAttributeReadOnly) return false; break; } } } return Parent::putByIndex(thisObject, exec, propertyIndex, value, shouldThrow); } template bool JSCallbackObject::deleteProperty(JSCell* cell, ExecState* exec, PropertyName propertyName) { VM& vm = exec->vm(); auto scope = DECLARE_THROW_SCOPE(vm); JSCallbackObject* thisObject = jsCast(cell); JSContextRef ctx = toRef(exec); JSObjectRef thisRef = toRef(thisObject); RefPtr propertyNameRef; if (StringImpl* name = propertyName.uid()) { for (JSClassRef jsClass = thisObject->classRef(); jsClass; jsClass = jsClass->parentClass) { if (JSObjectDeletePropertyCallback deleteProperty = jsClass->deleteProperty) { if (!propertyNameRef) propertyNameRef = OpaqueJSString::tryCreate(name); JSValueRef exception = 0; bool result; { JSLock::DropAllLocks dropAllLocks(exec); result = deleteProperty(ctx, thisRef, propertyNameRef.get(), &exception); } if (exception) throwException(exec, scope, toJS(exec, exception)); if (result || exception) return true; } if (OpaqueJSClassStaticValuesTable* staticValues = jsClass->staticValues(exec)) { if (StaticValueEntry* entry = staticValues->get(name)) { if (entry->attributes & kJSPropertyAttributeDontDelete) return false; return true; } } if (OpaqueJSClassStaticFunctionsTable* staticFunctions = jsClass->staticFunctions(exec)) { if (StaticFunctionEntry* entry = staticFunctions->get(name)) { if (entry->attributes & kJSPropertyAttributeDontDelete) return false; return true; } } } } return Parent::deleteProperty(thisObject, exec, propertyName); } template bool JSCallbackObject::deletePropertyByIndex(JSCell* cell, ExecState* exec, unsigned propertyName) { VM& vm = exec->vm(); JSCallbackObject* thisObject = jsCast(cell); return thisObject->methodTable(vm)->deleteProperty(thisObject, exec, Identifier::from(vm, propertyName)); } template ConstructType JSCallbackObject::getConstructData(JSCell* cell, ConstructData& constructData) { JSCallbackObject* thisObject = jsCast(cell); for (JSClassRef jsClass = thisObject->classRef(); jsClass; jsClass = jsClass->parentClass) { if (jsClass->callAsConstructor) { constructData.native.function = construct; return ConstructType::Host; } } return ConstructType::None; } template EncodedJSValue JSCallbackObject::construct(ExecState* exec) { VM& vm = exec->vm(); auto scope = DECLARE_THROW_SCOPE(vm); JSObject* constructor = exec->jsCallee(); JSContextRef execRef = toRef(exec); JSObjectRef constructorRef = toRef(constructor); for (JSClassRef jsClass = jsCast*>(constructor)->classRef(); jsClass; jsClass = jsClass->parentClass) { if (JSObjectCallAsConstructorCallback callAsConstructor = jsClass->callAsConstructor) { size_t argumentCount = exec->argumentCount(); Vector arguments; arguments.reserveInitialCapacity(argumentCount); for (size_t i = 0; i < argumentCount; ++i) arguments.uncheckedAppend(toRef(exec, exec->uncheckedArgument(i))); JSValueRef exception = 0; JSObject* result; { JSLock::DropAllLocks dropAllLocks(exec); result = toJS(callAsConstructor(execRef, constructorRef, argumentCount, arguments.data(), &exception)); } if (exception) throwException(exec, scope, toJS(exec, exception)); return JSValue::encode(result); } } RELEASE_ASSERT_NOT_REACHED(); // getConstructData should prevent us from reaching here return JSValue::encode(JSValue()); } template bool JSCallbackObject::customHasInstance(JSObject* object, ExecState* exec, JSValue value) { VM& vm = exec->vm(); auto scope = DECLARE_THROW_SCOPE(vm); JSCallbackObject* thisObject = jsCast(object); JSContextRef execRef = toRef(exec); JSObjectRef thisRef = toRef(thisObject); for (JSClassRef jsClass = thisObject->classRef(); jsClass; jsClass = jsClass->parentClass) { if (JSObjectHasInstanceCallback hasInstance = jsClass->hasInstance) { JSValueRef valueRef = toRef(exec, value); JSValueRef exception = 0; bool result; { JSLock::DropAllLocks dropAllLocks(exec); result = hasInstance(execRef, thisRef, valueRef, &exception); } if (exception) throwException(exec, scope, toJS(exec, exception)); return result; } } return false; } template CallType JSCallbackObject::getCallData(JSCell* cell, CallData& callData) { JSCallbackObject* thisObject = jsCast(cell); for (JSClassRef jsClass = thisObject->classRef(); jsClass; jsClass = jsClass->parentClass) { if (jsClass->callAsFunction) { callData.native.function = call; return CallType::Host; } } return CallType::None; } template EncodedJSValue JSCallbackObject::call(ExecState* exec) { VM& vm = exec->vm(); auto scope = DECLARE_THROW_SCOPE(vm); JSContextRef execRef = toRef(exec); JSObjectRef functionRef = toRef(exec->jsCallee()); JSObjectRef thisObjRef = toRef(jsCast(exec->thisValue().toThis(exec, NotStrictMode))); for (JSClassRef jsClass = jsCast*>(toJS(functionRef))->classRef(); jsClass; jsClass = jsClass->parentClass) { if (JSObjectCallAsFunctionCallback callAsFunction = jsClass->callAsFunction) { size_t argumentCount = exec->argumentCount(); Vector arguments; arguments.reserveInitialCapacity(argumentCount); for (size_t i = 0; i < argumentCount; ++i) arguments.uncheckedAppend(toRef(exec, exec->uncheckedArgument(i))); JSValueRef exception = 0; JSValue result; { JSLock::DropAllLocks dropAllLocks(exec); result = toJS(exec, callAsFunction(execRef, functionRef, thisObjRef, argumentCount, arguments.data(), &exception)); } if (exception) throwException(exec, scope, toJS(exec, exception)); return JSValue::encode(result); } } RELEASE_ASSERT_NOT_REACHED(); // getCallData should prevent us from reaching here return JSValue::encode(JSValue()); } template void JSCallbackObject::getOwnNonIndexPropertyNames(JSObject* object, ExecState* exec, PropertyNameArray& propertyNames, EnumerationMode mode) { VM& vm = exec->vm(); JSCallbackObject* thisObject = jsCast(object); JSContextRef execRef = toRef(exec); JSObjectRef thisRef = toRef(thisObject); for (JSClassRef jsClass = thisObject->classRef(); jsClass; jsClass = jsClass->parentClass) { if (JSObjectGetPropertyNamesCallback getPropertyNames = jsClass->getPropertyNames) { JSLock::DropAllLocks dropAllLocks(exec); getPropertyNames(execRef, thisRef, toRef(&propertyNames)); } if (OpaqueJSClassStaticValuesTable* staticValues = jsClass->staticValues(exec)) { typedef OpaqueJSClassStaticValuesTable::const_iterator iterator; iterator end = staticValues->end(); for (iterator it = staticValues->begin(); it != end; ++it) { StringImpl* name = it->key.get(); StaticValueEntry* entry = it->value.get(); if (entry->getProperty && (!(entry->attributes & kJSPropertyAttributeDontEnum) || mode.includeDontEnumProperties())) { ASSERT(!name->isSymbol()); propertyNames.add(Identifier::fromString(vm, String(name))); } } } if (OpaqueJSClassStaticFunctionsTable* staticFunctions = jsClass->staticFunctions(exec)) { typedef OpaqueJSClassStaticFunctionsTable::const_iterator iterator; iterator end = staticFunctions->end(); for (iterator it = staticFunctions->begin(); it != end; ++it) { StringImpl* name = it->key.get(); StaticFunctionEntry* entry = it->value.get(); if (!(entry->attributes & kJSPropertyAttributeDontEnum) || mode.includeDontEnumProperties()) { ASSERT(!name->isSymbol()); propertyNames.add(Identifier::fromString(vm, String(name))); } } } } Parent::getOwnNonIndexPropertyNames(thisObject, exec, propertyNames, mode); } template void JSCallbackObject::setPrivate(void* data) { m_callbackObjectData->privateData = data; } template void* JSCallbackObject::getPrivate() { return m_callbackObjectData->privateData; } template bool JSCallbackObject::inherits(JSClassRef c) const { for (JSClassRef jsClass = classRef(); jsClass; jsClass = jsClass->parentClass) { if (jsClass == c) return true; } return false; } template JSValue JSCallbackObject::getStaticValue(ExecState* exec, PropertyName propertyName) { VM& vm = exec->vm(); auto scope = DECLARE_THROW_SCOPE(vm); JSObjectRef thisRef = toRef(this); if (StringImpl* name = propertyName.uid()) { for (JSClassRef jsClass = classRef(); jsClass; jsClass = jsClass->parentClass) { if (OpaqueJSClassStaticValuesTable* staticValues = jsClass->staticValues(exec)) { if (StaticValueEntry* entry = staticValues->get(name)) { if (JSObjectGetPropertyCallback getProperty = entry->getProperty) { JSValueRef exception = 0; JSValueRef value; { JSLock::DropAllLocks dropAllLocks(exec); value = getProperty(toRef(exec), thisRef, entry->propertyNameRef.get(), &exception); } if (exception) { throwException(exec, scope, toJS(exec, exception)); return jsUndefined(); } if (value) return toJS(exec, value); } } } } } return JSValue(); } template EncodedJSValue JSCallbackObject::staticFunctionGetter(ExecState* exec, EncodedJSValue thisValue, PropertyName propertyName) { VM& vm = exec->vm(); auto scope = DECLARE_THROW_SCOPE(vm); JSCallbackObject* thisObj = asCallbackObject(thisValue); // Check for cached or override property. PropertySlot slot2(thisObj, PropertySlot::InternalMethodType::VMInquiry); if (Parent::getOwnPropertySlot(thisObj, exec, propertyName, slot2)) return JSValue::encode(slot2.getValue(exec, propertyName)); if (StringImpl* name = propertyName.uid()) { for (JSClassRef jsClass = thisObj->classRef(); jsClass; jsClass = jsClass->parentClass) { if (OpaqueJSClassStaticFunctionsTable* staticFunctions = jsClass->staticFunctions(exec)) { if (StaticFunctionEntry* entry = staticFunctions->get(name)) { if (JSObjectCallAsFunctionCallback callAsFunction = entry->callAsFunction) { JSObject* o = JSCallbackFunction::create(vm, thisObj->globalObject(vm), callAsFunction, name); thisObj->putDirect(vm, propertyName, o, entry->attributes); return JSValue::encode(o); } } } } } return JSValue::encode(throwException(exec, scope, createReferenceError(exec, "Static function property defined with NULL callAsFunction callback."_s))); } template EncodedJSValue JSCallbackObject::callbackGetter(ExecState* exec, EncodedJSValue thisValue, PropertyName propertyName) { VM& vm = exec->vm(); auto scope = DECLARE_THROW_SCOPE(vm); JSCallbackObject* thisObj = asCallbackObject(thisValue); JSObjectRef thisRef = toRef(thisObj); RefPtr propertyNameRef; if (StringImpl* name = propertyName.uid()) { for (JSClassRef jsClass = thisObj->classRef(); jsClass; jsClass = jsClass->parentClass) { if (JSObjectGetPropertyCallback getProperty = jsClass->getProperty) { if (!propertyNameRef) propertyNameRef = OpaqueJSString::tryCreate(name); JSValueRef exception = 0; JSValueRef value; { JSLock::DropAllLocks dropAllLocks(exec); value = getProperty(toRef(exec), thisRef, propertyNameRef.get(), &exception); } if (exception) { throwException(exec, scope, toJS(exec, exception)); return JSValue::encode(jsUndefined()); } if (value) return JSValue::encode(toJS(exec, value)); } } } return JSValue::encode(throwException(exec, scope, createReferenceError(exec, "hasProperty callback returned true for a property that doesn't exist."_s))); } } // namespace JSC