https://bugs.webkit.org/show_bug.cgi?id=183072

LLIntOffsetsExtractor.cpp

#include <cstddef>
#include <utility>
#include <cstdint>

#define ALWAYS_INLINE inline
#define bitwise_cast reinterpret_cast

namespace WTF {

using PoisonedBits = uintptr_t;

namespace PoisonedImplHelper {

template<typename T>
struct isFunctionPointer : std::integral_constant<bool, std::is_function<typename std::remove_pointer<T>::type>::value> { };

template<typename T>
struct isVoidPointer : std::integral_constant<bool, std::is_void<typename std::remove_pointer<T>::type>::value> { };

template<typename T>
struct isConvertibleToReference : std::integral_constant<bool, !isFunctionPointer<T>::value && !isVoidPointer<T>::value> { };

template<typename T>
typename std::enable_if_t<!isConvertibleToReference<T>::value, int>&
asReference(T) {  }

template<typename T>
typename std::enable_if_t<isConvertibleToReference<T>::value, typename std::remove_pointer<T>::type>&
asReference(T ptr) { return *ptr; }

} // namespace PoisonedImplHelper

enum AlreadyPoisonedTag { AlreadyPoisoned };

template<uintptr_t& poisonKey>
class Poison {
public:
    template<typename PoisonedType = void>
    static uintptr_t key(const PoisonedType* = nullptr) { return poisonKey; }
};

template<typename Poison, typename T, typename = std::enable_if_t<std::is_pointer<T>::value>>
class Poisoned {
public:
    static constexpr bool isPoisonedType = true;

    Poisoned() { }

    Poisoned(std::nullptr_t) { }

    Poisoned(T ptr)
        : m_poisonedBits(poison(ptr))
    { }

    Poisoned(const Poisoned&) = default;

    template<typename Other, typename = std::enable_if_t<Other::isPoisonedType>>
    Poisoned(const Other& other)
        : m_poisonedBits(poison<T>(other.unpoisoned()))
    { }

    Poisoned(Poisoned&&) = default;

    explicit Poisoned(AlreadyPoisonedTag, PoisonedBits poisonedBits)
        : m_poisonedBits(poisonedBits)
    { }

    template<typename U = void*> static void assertIsPoisoned(U) { }
    template<typename U = void*> static void assertIsNotPoisoned(U) { }

    void assertIsPoisoned() const { assertIsPoisoned(m_poisonedBits); }
    void assertIsNotPoisoned() const { assertIsNotPoisoned(m_poisonedBits); }

    template<typename U = T>
    U unpoisoned() const { return unpoison<U>(m_poisonedBits); }

    void clear() { m_poisonedBits = 0; }

    auto& operator*() const { return PoisonedImplHelper::asReference(unpoison(m_poisonedBits)); }
    ALWAYS_INLINE T operator->() const { return unpoison(m_poisonedBits); }

    template<typename U = PoisonedBits>
    U bits() const { return bitwise_cast<U>(m_poisonedBits); }

    bool operator!() const { return !m_poisonedBits; }
    explicit operator bool() const { return !!m_poisonedBits; }

    bool operator==(const Poisoned& b) const { return m_poisonedBits == b.m_poisonedBits; }
    bool operator!=(const Poisoned& b) const { return m_poisonedBits != b.m_poisonedBits; }

    bool operator==(T b) const { return unpoisoned() == b; }
    bool operator!=(T b) const { return unpoisoned() != b; }
    bool operator<(T b) const { return unpoisoned() < b; }
    bool operator<=(T b) const { return unpoisoned() <= b; }
    bool operator>(T b) const { return unpoisoned() > b; }
    bool operator>=(T b) const { return unpoisoned() >= b; }

    Poisoned& operator=(T ptr)
    {
        m_poisonedBits = poison(ptr);
        return *this;
    }
    Poisoned& operator=(const Poisoned&) = default;

    Poisoned& operator=(std::nullptr_t)
    {
        clear();
        return *this;
    }

    template<typename Other, typename = std::enable_if_t<Other::isPoisonedType>>
    Poisoned& operator=(const Other& other)
    {
        m_poisonedBits = poison<T>(other.unpoisoned());
        return *this;
    }

    void swap(Poisoned& other)
    {
        std::swap(m_poisonedBits, other.m_poisonedBits);
    }

    void swap(std::nullptr_t) { clear(); }

    template<typename Other, typename = std::enable_if_t<Other::isPoisonedType>>
    void swap(Other& other)
    {
        T t1 = this->unpoisoned();
        T t2 = other.unpoisoned();
        std::swap(t1, t2);
        m_poisonedBits = poison(t1);
        other.m_poisonedBits = other.poison(t2);
    }

    void swap(T& t2)
    {
        T t1 = this->unpoisoned();
        std::swap(t1, t2);
        m_poisonedBits = poison(t1);
    }

    template<class U>
    T exchange(U&& newValue)
    {
        T oldValue = unpoisoned();
        m_poisonedBits = poison(std::forward<U>(newValue));
        return oldValue;
    }

private:
    template<typename U>
    ALWAYS_INLINE PoisonedBits poison(U ptr) const { return poison<PoisonedBits>(this, bitwise_cast<uintptr_t>(ptr)); }
    template<typename U = T>
    ALWAYS_INLINE U unpoison(PoisonedBits poisonedBits) const { return unpoison<U>(this, poisonedBits); }

    constexpr static PoisonedBits poison(const Poisoned*, std::nullptr_t) { return 0; }

    template<typename U>
    ALWAYS_INLINE static PoisonedBits poison(const Poisoned* thisPoisoned, U ptr) { return ptr ? bitwise_cast<PoisonedBits>(ptr) ^ Poison::key(thisPoisoned) : 0; }
    template<typename U = T>
    ALWAYS_INLINE static U unpoison(const Poisoned* thisPoisoned, PoisonedBits poisonedBits) { return poisonedBits ? bitwise_cast<U>(poisonedBits ^ Poison::key(thisPoisoned)) : bitwise_cast<U>(0ll); }

    PoisonedBits m_poisonedBits { 0 };

    template<typename, typename, typename> friend class Poisoned;
};

template<typename T, typename U, typename = std::enable_if_t<T::isPoisonedType && U::isPoisonedType && !std::is_same<T, U>::value>>
inline bool operator==(const T& a, const U& b) { return a.unpoisoned() == b.unpoisoned(); }

template<typename T, typename U, typename = std::enable_if_t<T::isPoisonedType && U::isPoisonedType && !std::is_same<T, U>::value>>
inline bool operator!=(const T& a, const U& b) { return a.unpoisoned() != b.unpoisoned(); }

template<typename T, typename U, typename = std::enable_if_t<T::isPoisonedType && U::isPoisonedType>>
inline bool operator<(const T& a, const U& b) { return a.unpoisoned() < b.unpoisoned(); }

template<typename T, typename U, typename = std::enable_if_t<T::isPoisonedType && U::isPoisonedType>>
inline bool operator<=(const T& a, const U& b) { return a.unpoisoned() <= b.unpoisoned(); }

template<typename T, typename U, typename = std::enable_if_t<T::isPoisonedType && U::isPoisonedType>>
inline bool operator>(const T& a, const U& b) { return a.unpoisoned() > b.unpoisoned(); }

template<typename T, typename U, typename = std::enable_if_t<T::isPoisonedType && U::isPoisonedType>>
inline bool operator>=(const T& a, const U& b) { return a.unpoisoned() >= b.unpoisoned(); }

template<typename T, typename U, typename = std::enable_if_t<T::isPoisonedType>>
inline void swap(T& a, U& b)
{
    a.swap(b);
}



template<typename Poison, typename T>
struct PoisonedPtrTraits {
    using StorageType = Poisoned<Poison, T*>;

    template<class U> static ALWAYS_INLINE T* exchange(StorageType& ptr, U&& newValue) { return ptr.exchange(newValue); }

    template<typename Other>
    static ALWAYS_INLINE void swap(Poisoned<Poison, T*>& a, Other& b) { a.swap(b); }

    static ALWAYS_INLINE T* unwrap(const StorageType& ptr) { return ptr.unpoisoned(); }
};

template<typename Poison, typename T>
struct PoisonedValueTraits {
    using StorageType = Poisoned<Poison, T>;

    template<class U> static ALWAYS_INLINE T exchange(StorageType& val, U&& newValue) { return val.exchange(newValue); }

    template<typename Other>
    static ALWAYS_INLINE void swap(Poisoned<Poison, T>& a, Other& b) { a.swap(b); }

    static ALWAYS_INLINE T unwrap(const StorageType& val) { return val.unpoisoned(); }
};

} // namespace WTF

using WTF::AlreadyPoisoned;
using WTF::Poison;
using WTF::Poisoned;
using WTF::PoisonedBits;
using WTF::PoisonedPtrTraits;
using WTF::PoisonedValueTraits;


#define POISON_KEY_NAME(_poisonID_) g_##_poisonID_##Poison

extern "C" uintptr_t POISON_KEY_NAME(JITCode);
using JITCodePoison = Poison<POISON_KEY_NAME(JITCode)>;

using PoisonedMasmPtr = Poisoned<JITCodePoison, void*>;

namespace JSC {

class MacroAssemblerCodePtr {
public:
    static MacroAssemblerCodePtr createFromExecutableAddress(void* value)
    {
        MacroAssemblerCodePtr result;
        result.m_value = PoisonedMasmPtr(value);
        return result;
    }

    PoisonedMasmPtr m_value;
};

class VM {
public:

    void foo();
    class DeletePropertyModeScope {
    public:
        DeletePropertyModeScope(VM& vm)
            : m_vm(vm)
        {
            m_vm.foo();
        }

    private:
        VM& m_vm;
    };

    MacroAssemblerCodePtr getCTIInternalFunctionTrampolineFor();
    
};

class ArrayBuffer {
public:
    static ptrdiff_t offsetOfData() { return offsetof(ArrayBuffer, m_contents) ; }
    void notifyIncommingReferencesOfTransfer(VM&);
    int m_contents;
};

}

using JSC::ArrayBuffer;

int main(int, char**)
{
    return 0;
}