Source/JavaScriptCore/runtime/JSDestructibleObject.h

/*
 * Copyright (C) 2012-2017 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 "JSObject.h"

namespace JSC {

struct ClassInfo;

class JSDestructibleObject : public JSNonFinalObject {
public:
    typedef JSNonFinalObject Base;

    static const bool needsDestruction = true;
    
    template<typename CellType>
    static CompleteSubspace* subspaceFor(VM& vm)
    {
        return &vm.destructibleObjectSpace;
    }

    const ClassInfo* classInfo() const { return m_classInfo.unpoisoned(); }
    
    static ptrdiff_t classInfoOffset() { return OBJECT_OFFSETOF(JSDestructibleObject, m_classInfo); }

protected:
    JSDestructibleObject(VM& vm, Structure* structure, Butterfly* butterfly = 0)
        : JSNonFinalObject(vm, structure, butterfly)
        , m_classInfo(structure->classInfo())
    {
        ASSERT(m_classInfo);
    }

private:
    PoisonedClassInfoPtr m_classInfo;
};

} // namespace JSC