Tools/TestWebKitAPI/SoftLinkShim.h

/*
 * Copyright (C) 2025 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
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 */

#pragma once

namespace TestWebKitAPI {

template<typename R, typename... Args>
class SoftLinkShim {
public:
    using Pointer = R(*)(Args...);
    using CanLoadPtr = bool(*)();

    SoftLinkShim(Pointer* originalFunctor, Pointer replacementFunctor)
        : m_originalFunctor { originalFunctor }
        , m_originalFunctorValue { *originalFunctor }
    {
        *m_originalFunctor = replacementFunctor;
    }

    SoftLinkShim(Pointer* originalFunctor, Pointer replacementFunctor, CanLoadPtr canLoadPtr)
        : m_originalFunctor { originalFunctor }
    {
        if (canLoadPtr)
            canLoadPtr();
        m_originalFunctorValue = *originalFunctor;
        *m_originalFunctor = replacementFunctor;
    }

    ~SoftLinkShim()
    {
        *m_originalFunctor = m_originalFunctorValue;
    }

private:
    Pointer* m_originalFunctor;
    Pointer m_originalFunctorValue;
};



}