blob: 7e64e05691d39310faa179bf51c31723dbf82498 [file] [log] [blame]
/*
* Copyright (C) 2016-2017 Apple Inc. All Rights Reserved.
*
* 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 "config.h"
#include "ProxyObject.h"
#include "ArrayConstructor.h"
#include "Error.h"
#include "IdentifierInlines.h"
#include "JSCInlines.h"
#include "JSObjectInlines.h"
#include "ObjectConstructor.h"
#include "SlotVisitorInlines.h"
#include "StructureInlines.h"
#include "VMInlines.h"
#include <wtf/NoTailCalls.h>
// Note that we use NO_TAIL_CALLS() throughout this file because we rely on the machine stack
// growing larger for throwing OOM errors for when we have an effectively cyclic prototype chain.
namespace JSC {
STATIC_ASSERT_IS_TRIVIALLY_DESTRUCTIBLE(ProxyObject);
const ClassInfo ProxyObject::s_info = { "ProxyObject", &Base::s_info, nullptr, nullptr, CREATE_METHOD_TABLE(ProxyObject) };
ProxyObject::ProxyObject(VM& vm, Structure* structure)
: Base(vm, structure)
{
}
String ProxyObject::toStringName(const JSObject* object, ExecState* exec)
{
VM& vm = exec->vm();
auto scope = DECLARE_THROW_SCOPE(vm);
const ProxyObject* proxy = jsCast<const ProxyObject*>(object);
while (proxy) {
const JSObject* target = proxy->target();
bool targetIsArray = isArray(exec, target);
if (UNLIKELY(scope.exception()))
break;
if (targetIsArray)
RELEASE_AND_RETURN(scope, target->classInfo(vm)->methodTable.toStringName(target, exec));
proxy = jsDynamicCast<const ProxyObject*>(vm, target);
}
return "Object"_s;
}
Structure* ProxyObject::structureForTarget(JSGlobalObject* globalObject, JSValue target)
{
if (!target.isObject())
return globalObject->proxyObjectStructure();
JSObject* targetAsObject = jsCast<JSObject*>(target);
CallData ignoredCallData;
VM& vm = globalObject->vm();
bool isCallable = targetAsObject->methodTable(vm)->getCallData(targetAsObject, ignoredCallData) != CallType::None;
return isCallable ? globalObject->callableProxyObjectStructure() : globalObject->proxyObjectStructure();
}
void ProxyObject::finishCreation(VM& vm, ExecState* exec, JSValue target, JSValue handler)
{
auto scope = DECLARE_THROW_SCOPE(vm);
Base::finishCreation(vm);
ASSERT(type() == ProxyObjectType);
if (!target.isObject()) {
throwTypeError(exec, scope, "A Proxy's 'target' should be an Object"_s);
return;
}
if (ProxyObject* targetAsProxy = jsDynamicCast<ProxyObject*>(vm, target)) {
if (targetAsProxy->handler().isNull()) {
throwTypeError(exec, scope, "If a Proxy's handler is another Proxy object, the other Proxy should not have been revoked"_s);
return;
}
}
if (!handler.isObject()) {
throwTypeError(exec, scope, "A Proxy's 'handler' should be an Object"_s);
return;
}
JSObject* targetAsObject = jsCast<JSObject*>(target);
CallData ignoredCallData;
m_isCallable = targetAsObject->methodTable(vm)->getCallData(targetAsObject, ignoredCallData) != CallType::None;
if (m_isCallable) {
TypeInfo info = structure(vm)->typeInfo();
RELEASE_ASSERT(info.implementsHasInstance() && info.implementsDefaultHasInstance());
}
m_isConstructible = jsCast<JSObject*>(target)->isConstructor(vm);
m_target.set(vm, this, targetAsObject);
m_handler.set(vm, this, handler);
}
static const ASCIILiteral s_proxyAlreadyRevokedErrorMessage { "Proxy has already been revoked. No more operations are allowed to be performed on it"_s };
static JSValue performProxyGet(ExecState* exec, ProxyObject* proxyObject, JSValue receiver, PropertyName propertyName)
{
NO_TAIL_CALLS();
VM& vm = exec->vm();
auto scope = DECLARE_THROW_SCOPE(vm);
if (UNLIKELY(!vm.isSafeToRecurseSoft())) {
throwStackOverflowError(exec, scope);
return { };
}
JSObject* target = proxyObject->target();
auto performDefaultGet = [&] {
scope.release();
PropertySlot slot(receiver, PropertySlot::InternalMethodType::Get);
bool hasProperty = target->getPropertySlot(exec, propertyName, slot);
EXCEPTION_ASSERT(!scope.exception() || !hasProperty);
if (hasProperty)
RELEASE_AND_RETURN(scope, slot.getValue(exec, propertyName));
return jsUndefined();
};
if (propertyName.isPrivateName())
return performDefaultGet();
JSValue handlerValue = proxyObject->handler();
if (handlerValue.isNull())
return throwTypeError(exec, scope, s_proxyAlreadyRevokedErrorMessage);
JSObject* handler = jsCast<JSObject*>(handlerValue);
CallData callData;
CallType callType;
JSValue getHandler = handler->getMethod(exec, callData, callType, vm.propertyNames->get, "'get' property of a Proxy's handler object should be callable"_s);
RETURN_IF_EXCEPTION(scope, { });
if (getHandler.isUndefined())
return performDefaultGet();
MarkedArgumentBuffer arguments;
arguments.append(target);
arguments.append(identifierToSafePublicJSValue(vm, Identifier::fromUid(&vm, propertyName.uid())));
arguments.append(receiver);
ASSERT(!arguments.hasOverflowed());
JSValue trapResult = call(exec, getHandler, callType, callData, handler, arguments);
RETURN_IF_EXCEPTION(scope, { });
PropertyDescriptor descriptor;
bool result = target->getOwnPropertyDescriptor(exec, propertyName, descriptor);
EXCEPTION_ASSERT(!scope.exception() || !result);
if (result) {
if (descriptor.isDataDescriptor() && !descriptor.configurable() && !descriptor.writable()) {
if (!sameValue(exec, descriptor.value(), trapResult))
return throwTypeError(exec, scope, "Proxy handler's 'get' result of a non-configurable and non-writable property should be the same value as the target's property"_s);
} else if (descriptor.isAccessorDescriptor() && !descriptor.configurable() && descriptor.getter().isUndefined()) {
if (!trapResult.isUndefined())
return throwTypeError(exec, scope, "Proxy handler's 'get' result of a non-configurable accessor property without a getter should be undefined"_s);
}
}
RETURN_IF_EXCEPTION(scope, { });
return trapResult;
}
bool ProxyObject::performGet(ExecState* exec, PropertyName propertyName, PropertySlot& slot)
{
NO_TAIL_CALLS();
VM& vm = exec->vm();
auto scope = DECLARE_THROW_SCOPE(vm);
JSValue result = performProxyGet(exec, this, slot.thisValue(), propertyName);
RETURN_IF_EXCEPTION(scope, false);
unsigned ignoredAttributes = 0;
slot.setValue(this, ignoredAttributes, result);
return true;
}
bool ProxyObject::performInternalMethodGetOwnProperty(ExecState* exec, PropertyName propertyName, PropertySlot& slot)
{
NO_TAIL_CALLS();
VM& vm = exec->vm();
auto scope = DECLARE_THROW_SCOPE(vm);
if (UNLIKELY(!vm.isSafeToRecurseSoft())) {
throwStackOverflowError(exec, scope);
return false;
}
JSObject* target = this->target();
auto performDefaultGetOwnProperty = [&] {
return target->methodTable(vm)->getOwnPropertySlot(target, exec, propertyName, slot);
};
if (propertyName.isPrivateName())
RELEASE_AND_RETURN(scope, performDefaultGetOwnProperty());
JSValue handlerValue = this->handler();
if (handlerValue.isNull()) {
throwVMTypeError(exec, scope, s_proxyAlreadyRevokedErrorMessage);
return false;
}
JSObject* handler = jsCast<JSObject*>(handlerValue);
CallData callData;
CallType callType;
JSValue getOwnPropertyDescriptorMethod = handler->getMethod(exec, callData, callType, makeIdentifier(vm, "getOwnPropertyDescriptor"), "'getOwnPropertyDescriptor' property of a Proxy's handler should be callable"_s);
RETURN_IF_EXCEPTION(scope, false);
if (getOwnPropertyDescriptorMethod.isUndefined())
RELEASE_AND_RETURN(scope, performDefaultGetOwnProperty());
MarkedArgumentBuffer arguments;
arguments.append(target);
arguments.append(identifierToSafePublicJSValue(vm, Identifier::fromUid(&vm, propertyName.uid())));
ASSERT(!arguments.hasOverflowed());
JSValue trapResult = call(exec, getOwnPropertyDescriptorMethod, callType, callData, handler, arguments);
RETURN_IF_EXCEPTION(scope, false);
if (!trapResult.isUndefined() && !trapResult.isObject()) {
throwVMTypeError(exec, scope, "result of 'getOwnPropertyDescriptor' call should either be an Object or undefined"_s);
return false;
}
PropertyDescriptor targetPropertyDescriptor;
bool isTargetPropertyDescriptorDefined = target->getOwnPropertyDescriptor(exec, propertyName, targetPropertyDescriptor);
RETURN_IF_EXCEPTION(scope, false);
if (trapResult.isUndefined()) {
if (!isTargetPropertyDescriptorDefined)
return false;
if (!targetPropertyDescriptor.configurable()) {
throwVMTypeError(exec, scope, "When the result of 'getOwnPropertyDescriptor' is undefined the target must be configurable"_s);
return false;
}
// FIXME: this doesn't work if 'target' is another Proxy. We don't have isExtensible implemented in a way that fits w/ Proxys.
// https://bugs.webkit.org/show_bug.cgi?id=154375
bool isExtensible = target->isExtensible(exec);
RETURN_IF_EXCEPTION(scope, false);
if (!isExtensible) {
// FIXME: Come up with a test for this error. I'm not sure how to because
// Object.seal(o) will make all fields [[Configurable]] false.
// https://bugs.webkit.org/show_bug.cgi?id=154376
throwVMTypeError(exec, scope, "When 'getOwnPropertyDescriptor' returns undefined, the 'target' of a Proxy should be extensible"_s);
return false;
}
return false;
}
bool isExtensible = target->isExtensible(exec);
RETURN_IF_EXCEPTION(scope, false);
PropertyDescriptor trapResultAsDescriptor;
toPropertyDescriptor(exec, trapResult, trapResultAsDescriptor);
RETURN_IF_EXCEPTION(scope, false);
bool throwException = false;
bool valid = validateAndApplyPropertyDescriptor(exec, nullptr, propertyName, isExtensible,
trapResultAsDescriptor, isTargetPropertyDescriptorDefined, targetPropertyDescriptor, throwException);
RETURN_IF_EXCEPTION(scope, false);
if (!valid) {
throwVMTypeError(exec, scope, "Result from 'getOwnPropertyDescriptor' fails the IsCompatiblePropertyDescriptor test"_s);
return false;
}
if (!trapResultAsDescriptor.configurable()) {
if (!isTargetPropertyDescriptorDefined || targetPropertyDescriptor.configurable()) {
throwVMTypeError(exec, scope, "Result from 'getOwnPropertyDescriptor' can't be non-configurable when the 'target' doesn't have it as an own property or if it is a configurable own property on 'target'"_s);
return false;
}
}
if (trapResultAsDescriptor.isAccessorDescriptor()) {
GetterSetter* getterSetter = trapResultAsDescriptor.slowGetterSetter(exec);
RETURN_IF_EXCEPTION(scope, false);
slot.setGetterSlot(this, trapResultAsDescriptor.attributes(), getterSetter);
} else if (trapResultAsDescriptor.isDataDescriptor() && !trapResultAsDescriptor.value().isEmpty())
slot.setValue(this, trapResultAsDescriptor.attributes(), trapResultAsDescriptor.value());
else
slot.setValue(this, trapResultAsDescriptor.attributes(), jsUndefined()); // We use undefined because it's the default value in object properties.
return true;
}
bool ProxyObject::performHasProperty(ExecState* exec, PropertyName propertyName, PropertySlot& slot)
{
NO_TAIL_CALLS();
VM& vm = exec->vm();
auto scope = DECLARE_THROW_SCOPE(vm);
if (UNLIKELY(!vm.isSafeToRecurseSoft())) {
throwStackOverflowError(exec, scope);
return false;
}
JSObject* target = this->target();
slot.setValue(this, static_cast<unsigned>(PropertyAttribute::None), jsUndefined()); // Nobody should rely on our value, but be safe and protect against any bad actors reading our value.
auto performDefaultHasProperty = [&] {
return target->methodTable(vm)->getOwnPropertySlot(target, exec, propertyName, slot);
};
if (propertyName.isPrivateName())
RELEASE_AND_RETURN(scope, performDefaultHasProperty());
JSValue handlerValue = this->handler();
if (handlerValue.isNull()) {
throwVMTypeError(exec, scope, s_proxyAlreadyRevokedErrorMessage);
return false;
}
JSObject* handler = jsCast<JSObject*>(handlerValue);
CallData callData;
CallType callType;
JSValue hasMethod = handler->getMethod(exec, callData, callType, vm.propertyNames->has, "'has' property of a Proxy's handler should be callable"_s);
RETURN_IF_EXCEPTION(scope, false);
if (hasMethod.isUndefined())
RELEASE_AND_RETURN(scope, performDefaultHasProperty());
MarkedArgumentBuffer arguments;
arguments.append(target);
arguments.append(identifierToSafePublicJSValue(vm, Identifier::fromUid(&vm, propertyName.uid())));
ASSERT(!arguments.hasOverflowed());
JSValue trapResult = call(exec, hasMethod, callType, callData, handler, arguments);
RETURN_IF_EXCEPTION(scope, false);
bool trapResultAsBool = trapResult.toBoolean(exec);
RETURN_IF_EXCEPTION(scope, false);
if (!trapResultAsBool) {
PropertyDescriptor descriptor;
bool isPropertyDescriptorDefined = target->getOwnPropertyDescriptor(exec, propertyName, descriptor);
RETURN_IF_EXCEPTION(scope, false);
if (isPropertyDescriptorDefined) {
if (!descriptor.configurable()) {
throwVMTypeError(exec, scope, "Proxy 'has' must return 'true' for non-configurable properties"_s);
return false;
}
bool isExtensible = target->isExtensible(exec);
RETURN_IF_EXCEPTION(scope, false);
if (!isExtensible) {
throwVMTypeError(exec, scope, "Proxy 'has' must return 'true' for a non-extensible 'target' object with a configurable property"_s);
return false;
}
}
}
return trapResultAsBool;
}
bool ProxyObject::getOwnPropertySlotCommon(ExecState* exec, PropertyName propertyName, PropertySlot& slot)
{
slot.disableCaching();
slot.setIsTaintedByOpaqueObject();
if (slot.internalMethodType() == PropertySlot::InternalMethodType::VMInquiry)
return false;
VM& vm = exec->vm();
auto scope = DECLARE_THROW_SCOPE(vm);
if (UNLIKELY(!vm.isSafeToRecurseSoft())) {
throwStackOverflowError(exec, scope);
return false;
}
switch (slot.internalMethodType()) {
case PropertySlot::InternalMethodType::Get:
RELEASE_AND_RETURN(scope, performGet(exec, propertyName, slot));
case PropertySlot::InternalMethodType::GetOwnProperty:
RELEASE_AND_RETURN(scope, performInternalMethodGetOwnProperty(exec, propertyName, slot));
case PropertySlot::InternalMethodType::HasProperty:
RELEASE_AND_RETURN(scope, performHasProperty(exec, propertyName, slot));
default:
return false;
}
RELEASE_ASSERT_NOT_REACHED();
return false;
}
bool ProxyObject::getOwnPropertySlot(JSObject* object, ExecState* exec, PropertyName propertyName, PropertySlot& slot)
{
ProxyObject* thisObject = jsCast<ProxyObject*>(object);
return thisObject->getOwnPropertySlotCommon(exec, propertyName, slot);
}
bool ProxyObject::getOwnPropertySlotByIndex(JSObject* object, ExecState* exec, unsigned propertyName, PropertySlot& slot)
{
ProxyObject* thisObject = jsCast<ProxyObject*>(object);
Identifier ident = Identifier::from(exec, propertyName);
return thisObject->getOwnPropertySlotCommon(exec, ident.impl(), slot);
}
template <typename PerformDefaultPutFunction>
bool ProxyObject::performPut(ExecState* exec, JSValue putValue, JSValue thisValue, PropertyName propertyName, PerformDefaultPutFunction performDefaultPut, bool shouldThrow)
{
NO_TAIL_CALLS();
VM& vm = exec->vm();
auto scope = DECLARE_THROW_SCOPE(vm);
if (UNLIKELY(!vm.isSafeToRecurseSoft())) {
throwStackOverflowError(exec, scope);
return false;
}
if (propertyName.isPrivateName())
RELEASE_AND_RETURN(scope, performDefaultPut());
JSValue handlerValue = this->handler();
if (handlerValue.isNull()) {
throwVMTypeError(exec, scope, s_proxyAlreadyRevokedErrorMessage);
return false;
}
JSObject* handler = jsCast<JSObject*>(handlerValue);
CallData callData;
CallType callType;
JSValue setMethod = handler->getMethod(exec, callData, callType, vm.propertyNames->set, "'set' property of a Proxy's handler should be callable"_s);
RETURN_IF_EXCEPTION(scope, false);
JSObject* target = this->target();
if (setMethod.isUndefined())
RELEASE_AND_RETURN(scope, performDefaultPut());
MarkedArgumentBuffer arguments;
arguments.append(target);
arguments.append(identifierToSafePublicJSValue(vm, Identifier::fromUid(&vm, propertyName.uid())));
arguments.append(putValue);
arguments.append(thisValue);
ASSERT(!arguments.hasOverflowed());
JSValue trapResult = call(exec, setMethod, callType, callData, handler, arguments);
RETURN_IF_EXCEPTION(scope, false);
bool trapResultAsBool = trapResult.toBoolean(exec);
RETURN_IF_EXCEPTION(scope, false);
if (!trapResultAsBool) {
if (shouldThrow)
throwVMTypeError(exec, scope, makeString("Proxy object's 'set' trap returned falsy value for property '", String(propertyName.uid()), "'"));
return false;
}
PropertyDescriptor descriptor;
bool hasProperty = target->getOwnPropertyDescriptor(exec, propertyName, descriptor);
EXCEPTION_ASSERT(!scope.exception() || !hasProperty);
if (hasProperty) {
if (descriptor.isDataDescriptor() && !descriptor.configurable() && !descriptor.writable()) {
if (!sameValue(exec, descriptor.value(), putValue)) {
throwVMTypeError(exec, scope, "Proxy handler's 'set' on a non-configurable and non-writable property on 'target' should either return false or be the same value already on the 'target'"_s);
return false;
}
} else if (descriptor.isAccessorDescriptor() && !descriptor.configurable() && descriptor.setter().isUndefined()) {
throwVMTypeError(exec, scope, "Proxy handler's 'set' method on a non-configurable accessor property without a setter should return false"_s);
return false;
}
}
return true;
}
bool ProxyObject::put(JSCell* cell, ExecState* exec, PropertyName propertyName, JSValue value, PutPropertySlot& slot)
{
VM& vm = exec->vm();
slot.disableCaching();
ProxyObject* thisObject = jsCast<ProxyObject*>(cell);
auto performDefaultPut = [&] () {
JSObject* target = jsCast<JSObject*>(thisObject->target());
return target->methodTable(vm)->put(target, exec, propertyName, value, slot);
};
return thisObject->performPut(exec, value, slot.thisValue(), propertyName, performDefaultPut, slot.isStrictMode());
}
bool ProxyObject::putByIndexCommon(ExecState* exec, JSValue thisValue, unsigned propertyName, JSValue putValue, bool shouldThrow)
{
VM& vm = exec->vm();
auto scope = DECLARE_THROW_SCOPE(vm);
Identifier ident = Identifier::from(exec, propertyName);
RETURN_IF_EXCEPTION(scope, false);
auto performDefaultPut = [&] () {
JSObject* target = this->target();
bool isStrictMode = shouldThrow;
PutPropertySlot slot(thisValue, isStrictMode); // We must preserve the "this" target of the putByIndex.
return target->methodTable(vm)->put(target, exec, ident.impl(), putValue, slot);
};
RELEASE_AND_RETURN(scope, performPut(exec, putValue, thisValue, ident.impl(), performDefaultPut, shouldThrow));
}
bool ProxyObject::putByIndex(JSCell* cell, ExecState* exec, unsigned propertyName, JSValue value, bool shouldThrow)
{
ProxyObject* thisObject = jsCast<ProxyObject*>(cell);
return thisObject->putByIndexCommon(exec, thisObject, propertyName, value, shouldThrow);
}
static EncodedJSValue JSC_HOST_CALL performProxyCall(ExecState* exec)
{
NO_TAIL_CALLS();
VM& vm = exec->vm();
auto scope = DECLARE_THROW_SCOPE(vm);
if (UNLIKELY(!vm.isSafeToRecurseSoft())) {
throwStackOverflowError(exec, scope);
return encodedJSValue();
}
ProxyObject* proxy = jsCast<ProxyObject*>(exec->jsCallee());
JSValue handlerValue = proxy->handler();
if (handlerValue.isNull())
return throwVMTypeError(exec, scope, s_proxyAlreadyRevokedErrorMessage);
JSObject* handler = jsCast<JSObject*>(handlerValue);
CallData callData;
CallType callType;
JSValue applyMethod = handler->getMethod(exec, callData, callType, makeIdentifier(vm, "apply"), "'apply' property of a Proxy's handler should be callable"_s);
RETURN_IF_EXCEPTION(scope, encodedJSValue());
JSObject* target = proxy->target();
if (applyMethod.isUndefined()) {
CallData callData;
CallType callType = target->methodTable(vm)->getCallData(target, callData);
RELEASE_ASSERT(callType != CallType::None);
RELEASE_AND_RETURN(scope, JSValue::encode(call(exec, target, callType, callData, exec->thisValue(), ArgList(exec))));
}
JSArray* argArray = constructArray(exec, static_cast<ArrayAllocationProfile*>(nullptr), ArgList(exec));
RETURN_IF_EXCEPTION(scope, encodedJSValue());
MarkedArgumentBuffer arguments;
arguments.append(target);
arguments.append(exec->thisValue().toThis(exec, ECMAMode::StrictMode));
arguments.append(argArray);
ASSERT(!arguments.hasOverflowed());
RELEASE_AND_RETURN(scope, JSValue::encode(call(exec, applyMethod, callType, callData, handler, arguments)));
}
CallType ProxyObject::getCallData(JSCell* cell, CallData& callData)
{
ProxyObject* proxy = jsCast<ProxyObject*>(cell);
if (!proxy->m_isCallable) {
callData.js.functionExecutable = nullptr;
callData.js.scope = nullptr;
return CallType::None;
}
callData.native.function = performProxyCall;
return CallType::Host;
}
static EncodedJSValue JSC_HOST_CALL performProxyConstruct(ExecState* exec)
{
NO_TAIL_CALLS();
VM& vm = exec->vm();
auto scope = DECLARE_THROW_SCOPE(vm);
if (UNLIKELY(!vm.isSafeToRecurseSoft())) {
throwStackOverflowError(exec, scope);
return encodedJSValue();
}
ProxyObject* proxy = jsCast<ProxyObject*>(exec->jsCallee());
JSValue handlerValue = proxy->handler();
if (handlerValue.isNull())
return throwVMTypeError(exec, scope, s_proxyAlreadyRevokedErrorMessage);
JSObject* handler = jsCast<JSObject*>(handlerValue);
CallData callData;
CallType callType;
JSValue constructMethod = handler->getMethod(exec, callData, callType, makeIdentifier(vm, "construct"), "'construct' property of a Proxy's handler should be callable"_s);
RETURN_IF_EXCEPTION(scope, encodedJSValue());
JSObject* target = proxy->target();
if (constructMethod.isUndefined()) {
ConstructData constructData;
ConstructType constructType = target->methodTable(vm)->getConstructData(target, constructData);
RELEASE_ASSERT(constructType != ConstructType::None);
RELEASE_AND_RETURN(scope, JSValue::encode(construct(exec, target, constructType, constructData, ArgList(exec), exec->newTarget())));
}
JSArray* argArray = constructArray(exec, static_cast<ArrayAllocationProfile*>(nullptr), ArgList(exec));
RETURN_IF_EXCEPTION(scope, encodedJSValue());
MarkedArgumentBuffer arguments;
arguments.append(target);
arguments.append(argArray);
arguments.append(exec->newTarget());
ASSERT(!arguments.hasOverflowed());
JSValue result = call(exec, constructMethod, callType, callData, handler, arguments);
RETURN_IF_EXCEPTION(scope, encodedJSValue());
if (!result.isObject())
return throwVMTypeError(exec, scope, "Result from Proxy handler's 'construct' method should be an object"_s);
return JSValue::encode(result);
}
ConstructType ProxyObject::getConstructData(JSCell* cell, ConstructData& constructData)
{
ProxyObject* proxy = jsCast<ProxyObject*>(cell);
if (!proxy->m_isConstructible) {
constructData.js.functionExecutable = nullptr;
constructData.js.scope = nullptr;
return ConstructType::None;
}
constructData.native.function = performProxyConstruct;
return ConstructType::Host;
}
template <typename DefaultDeleteFunction>
bool ProxyObject::performDelete(ExecState* exec, PropertyName propertyName, DefaultDeleteFunction performDefaultDelete)
{
NO_TAIL_CALLS();
VM& vm = exec->vm();
auto scope = DECLARE_THROW_SCOPE(vm);
if (UNLIKELY(!vm.isSafeToRecurseSoft())) {
throwStackOverflowError(exec, scope);
return false;
}
if (propertyName.isPrivateName())
RELEASE_AND_RETURN(scope, performDefaultDelete());
JSValue handlerValue = this->handler();
if (handlerValue.isNull()) {
throwVMTypeError(exec, scope, s_proxyAlreadyRevokedErrorMessage);
return false;
}
JSObject* handler = jsCast<JSObject*>(handlerValue);
CallData callData;
CallType callType;
JSValue deletePropertyMethod = handler->getMethod(exec, callData, callType, makeIdentifier(vm, "deleteProperty"), "'deleteProperty' property of a Proxy's handler should be callable"_s);
RETURN_IF_EXCEPTION(scope, false);
JSObject* target = this->target();
if (deletePropertyMethod.isUndefined())
RELEASE_AND_RETURN(scope, performDefaultDelete());
MarkedArgumentBuffer arguments;
arguments.append(target);
arguments.append(identifierToSafePublicJSValue(vm, Identifier::fromUid(&vm, propertyName.uid())));
ASSERT(!arguments.hasOverflowed());
JSValue trapResult = call(exec, deletePropertyMethod, callType, callData, handler, arguments);
RETURN_IF_EXCEPTION(scope, false);
bool trapResultAsBool = trapResult.toBoolean(exec);
RETURN_IF_EXCEPTION(scope, false);
if (!trapResultAsBool)
return false;
PropertyDescriptor descriptor;
bool result = target->getOwnPropertyDescriptor(exec, propertyName, descriptor);
EXCEPTION_ASSERT(!scope.exception() || !result);
if (result) {
if (!descriptor.configurable()) {
throwVMTypeError(exec, scope, "Proxy handler's 'deleteProperty' method should return false when the target's property is not configurable"_s);
return false;
}
}
RETURN_IF_EXCEPTION(scope, false);
return true;
}
bool ProxyObject::deleteProperty(JSCell* cell, ExecState* exec, PropertyName propertyName)
{
ProxyObject* thisObject = jsCast<ProxyObject*>(cell);
auto performDefaultDelete = [&] () -> bool {
JSObject* target = thisObject->target();
return target->methodTable(exec->vm())->deleteProperty(target, exec, propertyName);
};
return thisObject->performDelete(exec, propertyName, performDefaultDelete);
}
bool ProxyObject::deletePropertyByIndex(JSCell* cell, ExecState* exec, unsigned propertyName)
{
ProxyObject* thisObject = jsCast<ProxyObject*>(cell);
Identifier ident = Identifier::from(exec, propertyName);
auto performDefaultDelete = [&] () -> bool {
JSObject* target = thisObject->target();
return target->methodTable(exec->vm())->deletePropertyByIndex(target, exec, propertyName);
};
return thisObject->performDelete(exec, ident.impl(), performDefaultDelete);
}
bool ProxyObject::performPreventExtensions(ExecState* exec)
{
NO_TAIL_CALLS();
VM& vm = exec->vm();
auto scope = DECLARE_THROW_SCOPE(vm);
if (UNLIKELY(!vm.isSafeToRecurseSoft())) {
throwStackOverflowError(exec, scope);
return false;
}
JSValue handlerValue = this->handler();
if (handlerValue.isNull()) {
throwVMTypeError(exec, scope, s_proxyAlreadyRevokedErrorMessage);
return false;
}
JSObject* handler = jsCast<JSObject*>(handlerValue);
CallData callData;
CallType callType;
JSValue preventExtensionsMethod = handler->getMethod(exec, callData, callType, makeIdentifier(vm, "preventExtensions"), "'preventExtensions' property of a Proxy's handler should be callable"_s);
RETURN_IF_EXCEPTION(scope, false);
JSObject* target = this->target();
if (preventExtensionsMethod.isUndefined())
RELEASE_AND_RETURN(scope, target->methodTable(vm)->preventExtensions(target, exec));
MarkedArgumentBuffer arguments;
arguments.append(target);
ASSERT(!arguments.hasOverflowed());
JSValue trapResult = call(exec, preventExtensionsMethod, callType, callData, handler, arguments);
RETURN_IF_EXCEPTION(scope, false);
bool trapResultAsBool = trapResult.toBoolean(exec);
RETURN_IF_EXCEPTION(scope, false);
if (trapResultAsBool) {
bool targetIsExtensible = target->isExtensible(exec);
RETURN_IF_EXCEPTION(scope, false);
if (targetIsExtensible) {
throwVMTypeError(exec, scope, "Proxy's 'preventExtensions' trap returned true even though its target is extensible. It should have returned false"_s);
return false;
}
}
return trapResultAsBool;
}
bool ProxyObject::preventExtensions(JSObject* object, ExecState* exec)
{
return jsCast<ProxyObject*>(object)->performPreventExtensions(exec);
}
bool ProxyObject::performIsExtensible(ExecState* exec)
{
NO_TAIL_CALLS();
VM& vm = exec->vm();
auto scope = DECLARE_THROW_SCOPE(vm);
if (UNLIKELY(!vm.isSafeToRecurseSoft())) {
throwStackOverflowError(exec, scope);
return false;
}
JSValue handlerValue = this->handler();
if (handlerValue.isNull()) {
throwVMTypeError(exec, scope, s_proxyAlreadyRevokedErrorMessage);
return false;
}
JSObject* handler = jsCast<JSObject*>(handlerValue);
CallData callData;
CallType callType;
JSValue isExtensibleMethod = handler->getMethod(exec, callData, callType, makeIdentifier(vm, "isExtensible"), "'isExtensible' property of a Proxy's handler should be callable"_s);
RETURN_IF_EXCEPTION(scope, false);
JSObject* target = this->target();
if (isExtensibleMethod.isUndefined())
RELEASE_AND_RETURN(scope, target->isExtensible(exec));
MarkedArgumentBuffer arguments;
arguments.append(target);
ASSERT(!arguments.hasOverflowed());
JSValue trapResult = call(exec, isExtensibleMethod, callType, callData, handler, arguments);
RETURN_IF_EXCEPTION(scope, false);
bool trapResultAsBool = trapResult.toBoolean(exec);
RETURN_IF_EXCEPTION(scope, false);
bool isTargetExtensible = target->isExtensible(exec);
RETURN_IF_EXCEPTION(scope, false);
if (trapResultAsBool != isTargetExtensible) {
if (isTargetExtensible) {
ASSERT(!trapResultAsBool);
throwVMTypeError(exec, scope, "Proxy object's 'isExtensible' trap returned false when the target is extensible. It should have returned true"_s);
} else {
ASSERT(!isTargetExtensible);
ASSERT(trapResultAsBool);
throwVMTypeError(exec, scope, "Proxy object's 'isExtensible' trap returned true when the target is non-extensible. It should have returned false"_s);
}
}
return trapResultAsBool;
}
bool ProxyObject::isExtensible(JSObject* object, ExecState* exec)
{
return jsCast<ProxyObject*>(object)->performIsExtensible(exec);
}
bool ProxyObject::performDefineOwnProperty(ExecState* exec, PropertyName propertyName, const PropertyDescriptor& descriptor, bool shouldThrow)
{
NO_TAIL_CALLS();
VM& vm = exec->vm();
auto scope = DECLARE_THROW_SCOPE(vm);
if (UNLIKELY(!vm.isSafeToRecurseSoft())) {
throwStackOverflowError(exec, scope);
return false;
}
JSObject* target = this->target();
auto performDefaultDefineOwnProperty = [&] {
RELEASE_AND_RETURN(scope, target->methodTable(vm)->defineOwnProperty(target, exec, propertyName, descriptor, shouldThrow));
};
if (propertyName.isPrivateName())
return performDefaultDefineOwnProperty();
JSValue handlerValue = this->handler();
if (handlerValue.isNull()) {
throwVMTypeError(exec, scope, s_proxyAlreadyRevokedErrorMessage);
return false;
}
JSObject* handler = jsCast<JSObject*>(handlerValue);
CallData callData;
CallType callType;
JSValue definePropertyMethod = handler->getMethod(exec, callData, callType, vm.propertyNames->defineProperty, "'defineProperty' property of a Proxy's handler should be callable"_s);
RETURN_IF_EXCEPTION(scope, false);
if (definePropertyMethod.isUndefined())
return performDefaultDefineOwnProperty();
JSObject* descriptorObject = constructObjectFromPropertyDescriptor(exec, descriptor);
RETURN_IF_EXCEPTION(scope, false);
MarkedArgumentBuffer arguments;
arguments.append(target);
arguments.append(identifierToSafePublicJSValue(vm, Identifier::fromUid(&vm, propertyName.uid())));
arguments.append(descriptorObject);
ASSERT(!arguments.hasOverflowed());
JSValue trapResult = call(exec, definePropertyMethod, callType, callData, handler, arguments);
RETURN_IF_EXCEPTION(scope, false);
bool trapResultAsBool = trapResult.toBoolean(exec);
RETURN_IF_EXCEPTION(scope, false);
if (!trapResultAsBool)
return false;
PropertyDescriptor targetDescriptor;
bool isTargetDescriptorDefined = target->getOwnPropertyDescriptor(exec, propertyName, targetDescriptor);
RETURN_IF_EXCEPTION(scope, false);
bool targetIsExtensible = target->isExtensible(exec);
RETURN_IF_EXCEPTION(scope, false);
bool settingConfigurableToFalse = descriptor.configurablePresent() && !descriptor.configurable();
if (!isTargetDescriptorDefined) {
if (!targetIsExtensible) {
throwVMTypeError(exec, scope, "Proxy's 'defineProperty' trap returned true even though getOwnPropertyDescriptor of the Proxy's target returned undefined and the target is non-extensible"_s);
return false;
}
if (settingConfigurableToFalse) {
throwVMTypeError(exec, scope, "Proxy's 'defineProperty' trap returned true for a non-configurable field even though getOwnPropertyDescriptor of the Proxy's target returned undefined"_s);
return false;
}
return true;
}
ASSERT(isTargetDescriptorDefined);
bool isCurrentDefined = isTargetDescriptorDefined;
const PropertyDescriptor& current = targetDescriptor;
bool throwException = false;
bool isCompatibleDescriptor = validateAndApplyPropertyDescriptor(exec, nullptr, propertyName, targetIsExtensible, descriptor, isCurrentDefined, current, throwException);
RETURN_IF_EXCEPTION(scope, false);
if (!isCompatibleDescriptor) {
throwVMTypeError(exec, scope, "Proxy's 'defineProperty' trap did not define a property on its target that is compatible with the trap's input descriptor"_s);
return false;
}
if (settingConfigurableToFalse && targetDescriptor.configurable()) {
throwVMTypeError(exec, scope, "Proxy's 'defineProperty' trap did not define a non-configurable property on its target even though the input descriptor to the trap said it must do so"_s);
return false;
}
return true;
}
bool ProxyObject::defineOwnProperty(JSObject* object, ExecState* exec, PropertyName propertyName, const PropertyDescriptor& descriptor, bool shouldThrow)
{
ProxyObject* thisObject = jsCast<ProxyObject*>(object);
return thisObject->performDefineOwnProperty(exec, propertyName, descriptor, shouldThrow);
}
void ProxyObject::performGetOwnPropertyNames(ExecState* exec, PropertyNameArray& propertyNames, EnumerationMode enumerationMode)
{
NO_TAIL_CALLS();
VM& vm = exec->vm();
auto scope = DECLARE_THROW_SCOPE(vm);
if (UNLIKELY(!vm.isSafeToRecurseSoft())) {
throwStackOverflowError(exec, scope);
return;
}
JSValue handlerValue = this->handler();
if (handlerValue.isNull()) {
throwVMTypeError(exec, scope, s_proxyAlreadyRevokedErrorMessage);
return;
}
JSObject* handler = jsCast<JSObject*>(handlerValue);
CallData callData;
CallType callType;
JSValue ownKeysMethod = handler->getMethod(exec, callData, callType, makeIdentifier(vm, "ownKeys"), "'ownKeys' property of a Proxy's handler should be callable"_s);
RETURN_IF_EXCEPTION(scope, void());
JSObject* target = this->target();
if (ownKeysMethod.isUndefined()) {
scope.release();
target->methodTable(vm)->getOwnPropertyNames(target, exec, propertyNames, enumerationMode);
return;
}
MarkedArgumentBuffer arguments;
arguments.append(target);
ASSERT(!arguments.hasOverflowed());
JSValue arrayLikeObject = call(exec, ownKeysMethod, callType, callData, handler, arguments);
RETURN_IF_EXCEPTION(scope, void());
PropertyNameArray trapResult(&vm, propertyNames.propertyNameMode(), propertyNames.privateSymbolMode());
HashSet<UniquedStringImpl*> uncheckedResultKeys;
{
HashSet<RefPtr<UniquedStringImpl>> seenKeys;
RuntimeTypeMask resultFilter = 0;
switch (propertyNames.propertyNameMode()) {
case PropertyNameMode::Symbols:
resultFilter = TypeSymbol;
break;
case PropertyNameMode::Strings:
resultFilter = TypeString;
break;
case PropertyNameMode::StringsAndSymbols:
resultFilter = TypeSymbol | TypeString;
break;
}
ASSERT(resultFilter);
auto addPropName = [&] (JSValue value, RuntimeType type) -> bool {
static const bool doExitEarly = true;
static const bool dontExitEarly = false;
Identifier ident = value.toPropertyKey(exec);
RETURN_IF_EXCEPTION(scope, doExitEarly);
// If trapResult contains any duplicate entries, throw a TypeError exception.
//
// Per spec[1], filtering by type should occur _after_ [[OwnPropertyKeys]], so duplicates
// are tracked in a separate hashtable from uncheckedResultKeys (which only contain the
// keys filtered by type).
//
// [1] Per https://tc39.github.io/ecma262/#sec-proxy-object-internal-methods-and-internal-slots-ownpropertykeysmust not contain any duplicate names"_s);
if (!seenKeys.add(ident.impl()).isNewEntry) {
throwTypeError(exec, scope, "Proxy handler's 'ownKeys' trap result must not contain any duplicate names"_s);
return doExitEarly;
}
if (!(type & resultFilter))
return dontExitEarly;
uncheckedResultKeys.add(ident.impl());
trapResult.add(ident.impl());
return dontExitEarly;
};
RuntimeTypeMask dontThrowAnExceptionTypeFilter = TypeString | TypeSymbol;
createListFromArrayLike(exec, arrayLikeObject, dontThrowAnExceptionTypeFilter, "Proxy handler's 'ownKeys' method must return an object"_s, "Proxy handler's 'ownKeys' method must return an array-like object containing only Strings and Symbols"_s, addPropName);
RETURN_IF_EXCEPTION(scope, void());
}
bool targetIsExensible = target->isExtensible(exec);
RETURN_IF_EXCEPTION(scope, void());
PropertyNameArray targetKeys(&vm, propertyNames.propertyNameMode(), propertyNames.privateSymbolMode());
target->methodTable(vm)->getOwnPropertyNames(target, exec, targetKeys, enumerationMode);
RETURN_IF_EXCEPTION(scope, void());
Vector<UniquedStringImpl*> targetConfigurableKeys;
Vector<UniquedStringImpl*> targetNonConfigurableKeys;
for (const Identifier& ident : targetKeys) {
PropertyDescriptor descriptor;
bool isPropertyDefined = target->getOwnPropertyDescriptor(exec, ident.impl(), descriptor);
RETURN_IF_EXCEPTION(scope, void());
if (isPropertyDefined && !descriptor.configurable())
targetNonConfigurableKeys.append(ident.impl());
else
targetConfigurableKeys.append(ident.impl());
}
enum ContainedIn { IsContainedIn, IsNotContainedIn };
auto removeIfContainedInUncheckedResultKeys = [&] (UniquedStringImpl* impl) -> ContainedIn {
auto iter = uncheckedResultKeys.find(impl);
if (iter == uncheckedResultKeys.end())
return IsNotContainedIn;
uncheckedResultKeys.remove(iter);
return IsContainedIn;
};
for (UniquedStringImpl* impl : targetNonConfigurableKeys) {
if (removeIfContainedInUncheckedResultKeys(impl) == IsNotContainedIn) {
throwVMTypeError(exec, scope, makeString("Proxy object's 'target' has the non-configurable property '", String(impl), "' that was not in the result from the 'ownKeys' trap"));
return;
}
}
if (!targetIsExensible) {
for (UniquedStringImpl* impl : targetConfigurableKeys) {
if (removeIfContainedInUncheckedResultKeys(impl) == IsNotContainedIn) {
throwVMTypeError(exec, scope, makeString("Proxy object's non-extensible 'target' has configurable property '", String(impl), "' that was not in the result from the 'ownKeys' trap"));
return;
}
}
if (uncheckedResultKeys.size()) {
throwVMTypeError(exec, scope, "Proxy handler's 'ownKeys' method returned a key that was not present in its non-extensible target"_s);
return;
}
}
if (!enumerationMode.includeDontEnumProperties()) {
// Filtering DontEnum properties is observable in proxies and must occur following the invariant checks above.
for (auto propertyName : trapResult) {
PropertySlot slot(this, PropertySlot::InternalMethodType::GetOwnProperty);
auto result = getOwnPropertySlotCommon(exec, propertyName, slot);
RETURN_IF_EXCEPTION(scope, void());
if (!result)
continue;
if (slot.attributes() & PropertyAttribute::DontEnum)
continue;
propertyNames.add(propertyName.impl());
}
} else {
for (auto propertyName : trapResult)
propertyNames.add(propertyName.impl());
}
}
void ProxyObject::getOwnPropertyNames(JSObject* object, ExecState* exec, PropertyNameArray& propertyNameArray, EnumerationMode enumerationMode)
{
ProxyObject* thisObject = jsCast<ProxyObject*>(object);
thisObject->performGetOwnPropertyNames(exec, propertyNameArray, enumerationMode);
}
void ProxyObject::getPropertyNames(JSObject* object, ExecState* exec, PropertyNameArray& propertyNameArray, EnumerationMode enumerationMode)
{
NO_TAIL_CALLS();
JSObject::getPropertyNames(object, exec, propertyNameArray, enumerationMode);
}
void ProxyObject::getOwnNonIndexPropertyNames(JSObject*, ExecState*, PropertyNameArray&, EnumerationMode)
{
RELEASE_ASSERT_NOT_REACHED();
}
void ProxyObject::getStructurePropertyNames(JSObject*, ExecState*, PropertyNameArray&, EnumerationMode)
{
// We should always go down the getOwnPropertyNames path.
RELEASE_ASSERT_NOT_REACHED();
}
void ProxyObject::getGenericPropertyNames(JSObject*, ExecState*, PropertyNameArray&, EnumerationMode)
{
RELEASE_ASSERT_NOT_REACHED();
}
bool ProxyObject::performSetPrototype(ExecState* exec, JSValue prototype, bool shouldThrowIfCantSet)
{
NO_TAIL_CALLS();
ASSERT(prototype.isObject() || prototype.isNull());
VM& vm = exec->vm();
auto scope = DECLARE_THROW_SCOPE(vm);
if (UNLIKELY(!vm.isSafeToRecurseSoft())) {
throwStackOverflowError(exec, scope);
return false;
}
JSValue handlerValue = this->handler();
if (handlerValue.isNull()) {
throwVMTypeError(exec, scope, s_proxyAlreadyRevokedErrorMessage);
return false;
}
JSObject* handler = jsCast<JSObject*>(handlerValue);
CallData callData;
CallType callType;
JSValue setPrototypeOfMethod = handler->getMethod(exec, callData, callType, makeIdentifier(vm, "setPrototypeOf"), "'setPrototypeOf' property of a Proxy's handler should be callable"_s);
RETURN_IF_EXCEPTION(scope, false);
JSObject* target = this->target();
if (setPrototypeOfMethod.isUndefined())
RELEASE_AND_RETURN(scope, target->setPrototype(vm, exec, prototype, shouldThrowIfCantSet));
MarkedArgumentBuffer arguments;
arguments.append(target);
arguments.append(prototype);
ASSERT(!arguments.hasOverflowed());
JSValue trapResult = call(exec, setPrototypeOfMethod, callType, callData, handler, arguments);
RETURN_IF_EXCEPTION(scope, false);
bool trapResultAsBool = trapResult.toBoolean(exec);
RETURN_IF_EXCEPTION(scope, false);
if (!trapResultAsBool) {
if (shouldThrowIfCantSet)
throwVMTypeError(exec, scope, "Proxy 'setPrototypeOf' returned false indicating it could not set the prototype value. The operation was expected to succeed"_s);
return false;
}
bool targetIsExtensible = target->isExtensible(exec);
RETURN_IF_EXCEPTION(scope, false);
if (targetIsExtensible)
return true;
JSValue targetPrototype = target->getPrototype(vm, exec);
RETURN_IF_EXCEPTION(scope, false);
if (!sameValue(exec, prototype, targetPrototype)) {
throwVMTypeError(exec, scope, "Proxy 'setPrototypeOf' trap returned true when its target is non-extensible and the new prototype value is not the same as the current prototype value. It should have returned false"_s);
return false;
}
return true;
}
bool ProxyObject::setPrototype(JSObject* object, ExecState* exec, JSValue prototype, bool shouldThrowIfCantSet)
{
return jsCast<ProxyObject*>(object)->performSetPrototype(exec, prototype, shouldThrowIfCantSet);
}
JSValue ProxyObject::performGetPrototype(ExecState* exec)
{
NO_TAIL_CALLS();
VM& vm = exec->vm();
auto scope = DECLARE_THROW_SCOPE(vm);
if (UNLIKELY(!vm.isSafeToRecurseSoft())) {
throwStackOverflowError(exec, scope);
return { };
}
JSValue handlerValue = this->handler();
if (handlerValue.isNull()) {
throwVMTypeError(exec, scope, s_proxyAlreadyRevokedErrorMessage);
return { };
}
JSObject* handler = jsCast<JSObject*>(handlerValue);
CallData callData;
CallType callType;
JSValue getPrototypeOfMethod = handler->getMethod(exec, callData, callType, makeIdentifier(vm, "getPrototypeOf"), "'getPrototypeOf' property of a Proxy's handler should be callable"_s);
RETURN_IF_EXCEPTION(scope, { });
JSObject* target = this->target();
if (getPrototypeOfMethod.isUndefined())
RELEASE_AND_RETURN(scope, target->getPrototype(vm, exec));
MarkedArgumentBuffer arguments;
arguments.append(target);
ASSERT(!arguments.hasOverflowed());
JSValue trapResult = call(exec, getPrototypeOfMethod, callType, callData, handler, arguments);
RETURN_IF_EXCEPTION(scope, { });
if (!trapResult.isObject() && !trapResult.isNull()) {
throwVMTypeError(exec, scope, "Proxy handler's 'getPrototypeOf' trap should either return an object or null"_s);
return { };
}
bool targetIsExtensible = target->isExtensible(exec);
RETURN_IF_EXCEPTION(scope, { });
if (targetIsExtensible)
return trapResult;
JSValue targetPrototype = target->getPrototype(vm, exec);
RETURN_IF_EXCEPTION(scope, { });
if (!sameValue(exec, targetPrototype, trapResult)) {
throwVMTypeError(exec, scope, "Proxy's 'getPrototypeOf' trap for a non-extensible target should return the same value as the target's prototype"_s);
return { };
}
return trapResult;
}
JSValue ProxyObject::getPrototype(JSObject* object, ExecState* exec)
{
return jsCast<ProxyObject*>(object)->performGetPrototype(exec);
}
void ProxyObject::revoke(VM& vm)
{
// This should only ever be called once and we should strictly transition from Object to null.
RELEASE_ASSERT(!m_handler.get().isNull() && m_handler.get().isObject());
m_handler.set(vm, this, jsNull());
}
bool ProxyObject::isRevoked() const
{
return handler().isNull();
}
void ProxyObject::visitChildren(JSCell* cell, SlotVisitor& visitor)
{
ProxyObject* thisObject = jsCast<ProxyObject*>(cell);
ASSERT_GC_OBJECT_INHERITS(thisObject, info());
Base::visitChildren(thisObject, visitor);
visitor.append(thisObject->m_target);
visitor.append(thisObject->m_handler);
}
} // namespace JSC