// Copyright 2019 the V8 project authors. All rights reserved. // Use of this source code is governed by a BSD-style license that can be // found in the LICENSE file. #include 'src/builtins/builtins-proxy-gen.h' namespace proxy { // ES #sec-proxy-object-internal-methods-and-internal-slots-isextensible // https://tc39.github.io/ecma262/#sec-proxy-object-internal-methods-and-internal-slots-isextensible transitioning builtin ProxyIsExtensible(implicit context: Context)( proxy: JSProxy): JSAny { PerformStackCheck(); const kTrapName: constexpr string = 'isExtensible'; try { // 1. Let handler be O.[[ProxyHandler]]. // 2. If handler is null, throw a TypeError exception. // 3. Assert: Type(handler) is Object. assert(proxy.handler == Null || Is<JSReceiver>(proxy.handler)); const handler = Cast<JSReceiver>(proxy.handler) otherwise ThrowProxyHandlerRevoked; // 4. Let target be O.[[ProxyTarget]]. const target = proxy.target; // 5. Let trap be ? GetMethod(handler, "isExtensible"). // 6. If trap is undefined, then (see 6.a below). const trap: Callable = GetMethod(handler, kTrapName) otherwise goto TrapUndefined(target); // 7. Let booleanTrapResult be ToBoolean(? Call(trap, handler, « // target»)). const trapResult = ToBoolean(Call(context, trap, handler, target)); // 8. Let targetResult be ? IsExtensible(target). const targetResult: bool = ToBoolean(object::ObjectIsExtensibleImpl(target)); // 9. If SameValue(booleanTrapResult, targetResult) is false, throw a // TypeError exception. if (trapResult != targetResult) { ThrowTypeError( MessageTemplate::kProxyIsExtensibleInconsistent, SelectBooleanConstant(targetResult)); } // 10. Return booleanTrapResult. return SelectBooleanConstant(trapResult); } label TrapUndefined(target: JSAny) { // 6.a. Return ? IsExtensible(target). return object::ObjectIsExtensibleImpl(target); } label ThrowProxyHandlerRevoked deferred { ThrowTypeError(MessageTemplate::kProxyRevoked, kTrapName); } } }