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// 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
ProxyGetPrototypeOf(implicit context: Context)(proxy: JSProxy): JSAny {
PerformStackCheck();
const kTrapName: constexpr string = 'getPrototypeOf';
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, "getPrototypeOf").
// 6. If trap is undefined, then (see 6.a below).
const trap: Callable = GetMethod(handler, kTrapName)
otherwise goto TrapUndefined(target);
// 7. Let handlerProto be ? Call(trap, handler, « target »).
const handlerProto = Call(context, trap, handler, target);
// 8. If Type(handlerProto) is neither Object nor Null, throw a TypeError
// exception.
if (!Is<JSReceiver>(handlerProto)) {
goto ThrowProxyGetPrototypeOfInvalid;
}
// 9. Let extensibleTarget be ? IsExtensible(target).
// 10. If extensibleTarget is true, return handlerProto.
const extensibleTarget: JSAny = object::ObjectIsExtensible(target);
assert(extensibleTarget == True || extensibleTarget == False);
if (extensibleTarget == True) {
return handlerProto;
}
// 11. Let targetProto be ? target.[[GetPrototypeOf]]().
const targetProto = object::ObjectGetPrototypeOf(target);
// 12. If SameValue(handlerProto, targetProto) is false, throw a TypeError
// exception.
// 13. Return handlerProto.
if (SameValue(targetProto, handlerProto)) {
return handlerProto;
}
ThrowTypeError(kProxyGetPrototypeOfNonExtensible);
}
label TrapUndefined(target: JSAny) {
// 6.a. Return ? target.[[GetPrototypeOf]]().
return object::ObjectGetPrototypeOf(target);
}
label ThrowProxyHandlerRevoked deferred {
ThrowTypeError(kProxyRevoked, kTrapName);
}
label ThrowProxyGetPrototypeOfInvalid deferred {
ThrowTypeError(kProxyGetPrototypeOfInvalid);
}
}
}
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