Source/JavaScriptCore/runtime/ProxyObject.h

/*
 * Copyright (C) 2016 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. AND ITS CONTRIBUTORS ``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 ITS 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.
 */

#pragma once

#include "JSGlobalObject.h"
#include "JSObject.h"

namespace JSC {

class ProxyObject final : public JSNonFinalObject {
public:
    typedef JSNonFinalObject Base;

    static constexpr unsigned StructureFlags = Base::StructureFlags | OverridesGetOwnPropertySlot | OverridesGetCallData | InterceptsGetOwnPropertySlotByIndexEvenWhenLengthIsNotZero | OverridesGetPropertyNames | OverridesAnyFormOfGetPropertyNames | OverridesGetPrototype | ProhibitsPropertyCaching;

    template<typename CellType, SubspaceAccess mode>
    static IsoSubspace* subspaceFor(VM& vm)
    {
        return vm.proxyObjectSpace<mode>();
    }

    static ProxyObject* create(JSGlobalObject* globalObject, JSValue target, JSValue handler)
    {
        VM& vm = getVM(globalObject);
        Structure* structure = ProxyObject::structureForTarget(globalObject, target);
        ProxyObject* proxy = new (NotNull, allocateCell<ProxyObject>(vm.heap)) ProxyObject(vm, structure);
        proxy->finishCreation(vm, globalObject, target, handler);
        return proxy;
    }

    static Structure* createStructure(VM& vm, JSGlobalObject* globalObject, JSValue prototype, bool isCallable)
    {
        unsigned flags = StructureFlags;
        if (isCallable)
            flags |= (ImplementsHasInstance | ImplementsDefaultHasInstance);
        Structure* result = Structure::create(vm, globalObject, prototype, TypeInfo(ProxyObjectType, flags), info(), NonArray | MayHaveIndexedAccessors);
        result->setIsQuickPropertyAccessAllowedForEnumeration(false);
        RELEASE_ASSERT(!result->canAccessPropertiesQuicklyForEnumeration());
        RELEASE_ASSERT(!result->canCachePropertyNameEnumerator(vm));
        return result;
    }

    DECLARE_EXPORT_INFO;

    JSObject* target() const { return m_target.get(); }
    JSValue handler() const { return m_handler.get(); }

    static bool put(JSCell*, JSGlobalObject*, PropertyName, JSValue, PutPropertySlot&);
    static bool putByIndex(JSCell*, JSGlobalObject*, unsigned propertyName, JSValue, bool shouldThrow);
    bool putByIndexCommon(JSGlobalObject*, JSValue thisValue, unsigned propertyName, JSValue putValue, bool shouldThrow);
    JSValue performGetPrototype(JSGlobalObject*);
    void revoke(VM&);
    bool isRevoked() const;

private:
    JS_EXPORT_PRIVATE ProxyObject(VM&, Structure*);
    JS_EXPORT_PRIVATE void finishCreation(VM&, JSGlobalObject*, JSValue target, JSValue handler);
    JS_EXPORT_PRIVATE static Structure* structureForTarget(JSGlobalObject*, JSValue target);

    static bool getOwnPropertySlot(JSObject*, JSGlobalObject*, PropertyName, PropertySlot&);
    static bool getOwnPropertySlotByIndex(JSObject*, JSGlobalObject*, unsigned propertyName, PropertySlot&);
    static CallData getCallData(JSCell*);
    static CallData getConstructData(JSCell*);
    static bool deleteProperty(JSCell*, JSGlobalObject*, PropertyName, DeletePropertySlot&);
    static bool deletePropertyByIndex(JSCell*, JSGlobalObject*, unsigned propertyName);
    static bool preventExtensions(JSObject*, JSGlobalObject*);
    static bool isExtensible(JSObject*, JSGlobalObject*);
    static bool defineOwnProperty(JSObject*, JSGlobalObject*, PropertyName, const PropertyDescriptor&, bool shouldThrow);
    static void getOwnPropertyNames(JSObject*, JSGlobalObject*, PropertyNameArray&, EnumerationMode);
    static void getPropertyNames(JSObject*, JSGlobalObject*, PropertyNameArray&, EnumerationMode);
    static NO_RETURN_DUE_TO_CRASH void getOwnNonIndexPropertyNames(JSObject*, JSGlobalObject*, PropertyNameArray&, EnumerationMode);
    static NO_RETURN_DUE_TO_CRASH void getStructurePropertyNames(JSObject*, JSGlobalObject*, PropertyNameArray&, EnumerationMode);
    static NO_RETURN_DUE_TO_CRASH void getGenericPropertyNames(JSObject*, JSGlobalObject*, PropertyNameArray&, EnumerationMode);
    static bool setPrototype(JSObject*, JSGlobalObject*, JSValue prototype, bool shouldThrowIfCantSet);
    static JSValue getPrototype(JSObject*, JSGlobalObject*);
    static void visitChildren(JSCell*, SlotVisitor&);

    bool getOwnPropertySlotCommon(JSGlobalObject*, PropertyName, PropertySlot&);
    bool performInternalMethodGetOwnProperty(JSGlobalObject*, PropertyName, PropertySlot&);
    bool performGet(JSGlobalObject*, PropertyName, PropertySlot&);
    bool performHasProperty(JSGlobalObject*, PropertyName, PropertySlot&);
    template <typename DefaultDeleteFunction>
    bool performDelete(JSGlobalObject*, PropertyName, DefaultDeleteFunction);
    template <typename PerformDefaultPutFunction>
    bool performPut(JSGlobalObject*, JSValue putValue, JSValue thisValue, PropertyName, PerformDefaultPutFunction, bool shouldThrow);
    bool performPreventExtensions(JSGlobalObject*);
    bool performIsExtensible(JSGlobalObject*);
    bool performDefineOwnProperty(JSGlobalObject*, PropertyName, const PropertyDescriptor&, bool shouldThrow);
    void performGetOwnPropertyNames(JSGlobalObject*, PropertyNameArray&);
    void performGetOwnEnumerablePropertyNames(JSGlobalObject*, PropertyNameArray&);
    bool performSetPrototype(JSGlobalObject*, JSValue prototype, bool shouldThrowIfCantSet);

    WriteBarrier<JSObject> m_target;
    WriteBarrier<Unknown> m_handler;
    bool m_isCallable : 1;
    bool m_isConstructible : 1;
};

} // namespace JSC