third_party/v8/src/builtins/proxy-set-property.tq

// 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 {

extern transitioning runtime
SetPropertyWithReceiver(implicit context: Context)(
    Object, Name, Object, Object): void;

transitioning macro CallThrowTypeErrorIfStrict(implicit context: Context)(
    message: constexpr MessageTemplate) {
  ThrowTypeErrorIfStrict(SmiConstant(message), Null, Null);
}

// ES #sec-proxy-object-internal-methods-and-internal-slots-set-p-v-receiver
// https://tc39.github.io/ecma262/#sec-proxy-object-internal-methods-and-internal-slots-set-p-v-receiver
transitioning builtin
ProxySetProperty(implicit context: Context)(
    proxy: JSProxy, name: PropertyKey|PrivateSymbol, value: JSAny,
    receiverValue: JSAny): JSAny {
  // 1. Assert: IsPropertyKey(P) is true.
  assert(TaggedIsNotSmi(name));
  assert(Is<Name>(name));

  let key: PropertyKey;
  typeswitch (name) {
    case (PrivateSymbol): {
      CallThrowTypeErrorIfStrict(MessageTemplate::kProxyPrivate);
      return Undefined;
    }
    case (name: PropertyKey): {
      key = name;
    }
  }

  try {
    // 2. Let handler be O.[[ProxyHandler]].
    // 3. If handler is null, throw a TypeError exception.
    // 4. Assert: Type(handler) is Object.
    assert(proxy.handler == Null || Is<JSReceiver>(proxy.handler));
    const handler =
        Cast<JSReceiver>(proxy.handler) otherwise ThrowProxyHandlerRevoked;

    // 5. Let target be O.[[ProxyTarget]].
    const target = UnsafeCast<JSReceiver>(proxy.target);

    // 6. Let trap be ? GetMethod(handler, "set").
    // 7. If trap is undefined, then (see 7.a below).
    const trap: Callable = GetMethod(handler, 'set')
        otherwise goto TrapUndefined(target);

    // 8. Let booleanTrapResult be ToBoolean(? Call(trap, handler,
    // « target, P, V, Receiver »)).
    // 9. If booleanTrapResult is false, return false.
    // 10. Let targetDesc be ? target.[[GetOwnProperty]](P).
    // 11. If targetDesc is not undefined and targetDesc.[[Configurable]] is
    // false, then
    //    a. If IsDataDescriptor(targetDesc) is true and
    //    targetDesc.[[Writable]] is false, then
    //      i. If SameValue(V, targetDesc.[[Value]]) is false, throw a
    //      TypeError exception.
    //    b. If IsAccessorDescriptor(targetDesc) is true, then
    //      i. If targetDesc.[[Set]] is undefined, throw a TypeError
    //      exception.
    // 12. Return true.
    const trapResult =
        Call(context, trap, handler, target, key, value, receiverValue);
    if (ToBoolean(trapResult)) {
      CheckGetSetTrapResult(target, proxy, name, value, kProxySet);
      return value;
    }
    ThrowTypeErrorIfStrict(
        SmiConstant(MessageTemplate::kProxyTrapReturnedFalsishFor), 'set',
        name);
    return value;
  } label TrapUndefined(target: Object) {
    // 7.a. Return ? target.[[Set]](P, V, Receiver).
    SetPropertyWithReceiver(target, name, value, receiverValue);
    return value;
  } label ThrowProxyHandlerRevoked deferred {
    ThrowTypeError(MessageTemplate::kProxyRevoked, 'set');
  }
}
}