bool
BaseDOMProxyHandler::getPropertyDescriptor(JSContext* cx,
                                           JS::Handle<JSObject*> proxy,
                                           JS::Handle<jsid> id,
                                           MutableHandle<JSPropertyDescriptor> desc,
                                           unsigned flags)
{
  if (!getOwnPropertyDescriptor(cx, proxy, id, desc, flags)) {
    return false;
  }
  if (desc.object()) {
    return true;
  }

  JS::Rooted<JSObject*> proto(cx);
  if (!js::GetObjectProto(cx, proxy, &proto)) {
    return false;
  }
  if (!proto) {
    desc.object().set(nullptr);
    return true;
  }

  return JS_GetPropertyDescriptorById(cx, proto, id, 0, desc);
}
bool
DOMProxyHandler::getPropertyDescriptor(JSContext* cx, JS::Handle<JSObject*> proxy, JS::Handle<jsid> id,
                                       JSPropertyDescriptor* desc, unsigned flags)
{
  if (!getOwnPropertyDescriptor(cx, proxy, id, desc, flags)) {
    return false;
  }
  if (desc->obj) {
    return true;
  }

  JSObject* proto;
  if (!js::GetObjectProto(cx, proxy, &proto)) {
    return false;
  }
  if (!proto) {
    desc->obj = NULL;
    return true;
  }

  return JS_GetPropertyDescriptorById(cx, proto, id, 0, desc);
}
예제 #3
0
bool JSObject::defineOwnProperty(ExecState* exec, const Identifier& propertyName, PropertyDescriptor& descriptor, bool throwException)
{
    // If we have a new property we can just put it on normally
    PropertyDescriptor current;
    if (!getOwnPropertyDescriptor(exec, propertyName, current))
        return putDescriptor(exec, this, propertyName, descriptor, descriptor.attributes(), jsUndefined());

    if (descriptor.isEmpty())
        return true;

    if (current.equalTo(descriptor))
        return true;

    // Filter out invalid changes
    if (!current.configurable()) {
        if (descriptor.configurable()) {
            if (throwException)
                throwError(exec, TypeError, "Attempting to configurable attribute of unconfigurable property.");
            return false;
        }
        if (descriptor.enumerablePresent() && descriptor.enumerable() != current.enumerable()) {
            if (throwException)
                throwError(exec, TypeError, "Attempting to change enumerable attribute of unconfigurable property.");
            return false;
        }
    }

    // A generic descriptor is simply changing the attributes of an existing property
    if (descriptor.isGenericDescriptor()) {
        if (!current.attributesEqual(descriptor)) {
            deleteProperty(exec, propertyName);
            putDescriptor(exec, this, propertyName, descriptor, current.attributesWithOverride(descriptor), current.value());
        }
        return true;
    }

    // Changing between a normal property or an accessor property
    if (descriptor.isDataDescriptor() != current.isDataDescriptor()) {
        if (!current.configurable()) {
            if (throwException)
                throwError(exec, TypeError, "Attempting to change access mechanism for an unconfigurable property.");
            return false;
        }
        deleteProperty(exec, propertyName);
        return putDescriptor(exec, this, propertyName, descriptor, current.attributesWithOverride(descriptor), current.value() ? current.value() : jsUndefined());
    }

    // Changing the value and attributes of an existing property
    if (descriptor.isDataDescriptor()) {
        if (!current.configurable()) {
            if (!current.writable() && descriptor.writable()) {
                if (throwException)
                    throwError(exec, TypeError, "Attempting to change writable attribute of unconfigurable property.");
                return false;
            }
            if (!current.writable()) {
                if (descriptor.value() || !JSValue::strictEqual(current.value(), descriptor.value())) {
                    if (throwException)
                        throwError(exec, TypeError, "Attempting to change value of a readonly property.");
                    return false;
                }
            }
        } else if (current.attributesEqual(descriptor)) {
            if (!descriptor.value())
                return true;
            PutPropertySlot slot;
            put(exec, propertyName, descriptor.value(), slot);
            if (exec->hadException())
                return false;
            return true;
        }
        deleteProperty(exec, propertyName);
        return putDescriptor(exec, this, propertyName, descriptor, current.attributesWithOverride(descriptor), current.value());
    }

    // Changing the accessor functions of an existing accessor property
    ASSERT(descriptor.isAccessorDescriptor());
    if (!current.configurable()) {
        if (descriptor.setterPresent() && !(current.setter() && JSValue::strictEqual(current.setter(), descriptor.setter()))) {
            if (throwException)
                throwError(exec, TypeError, "Attempting to change the setter of an unconfigurable property.");
            return false;
        }
        if (descriptor.getterPresent() && !(current.getter() && JSValue::strictEqual(current.getter(), descriptor.getter()))) {
            if (throwException)
                throwError(exec, TypeError, "Attempting to change the getter of an unconfigurable property.");
            return false;
        }
    }
    JSValue accessor = getDirect(propertyName);
    if (!accessor)
        return false;
    GetterSetter* getterSetter = asGetterSetter(accessor);
    if (current.attributesEqual(descriptor)) {
        if (descriptor.setter())
            getterSetter->setSetter(asObject(descriptor.setter()));
        if (descriptor.getter())
            getterSetter->setGetter(asObject(descriptor.getter()));
        return true;
    }
    deleteProperty(exec, propertyName);
    unsigned attrs = current.attributesWithOverride(descriptor);
    if (descriptor.setter())
        attrs |= Setter;
    if (descriptor.getter())
        attrs |= Getter;
    putDirect(propertyName, getterSetter, attrs);
    return true;
}