Revision control
++ // Copyright (C) 2023 The Qt Company Ltd.
++ // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
++ // Qt-Security score:critical reason:data-parser
++
++ #ifndef QVARIANT_P_H
++ #define QVARIANT_P_H
++
++ //
++ // W A R N I N G
++ // -------------
++ //
++ // This file is not part of the Qt API. It exists purely as an
++ // implementation detail. This header file may change from version to
++ // version without notice, or even be removed.
++ //
++ // We mean it.
++ //
++
++ #include "qvariant.h"
++
++ QT_BEGIN_NAMESPACE
++
++ inline auto customConstructSharedImpl(size_t size, size_t align)
++ {
++ struct Deleter {
++ void operator()(QVariant::PrivateShared *p) const
++ { QVariant::PrivateShared::free(p); }
++ };
++
++ // this is exception-safe
++ std::unique_ptr<QVariant::PrivateShared, Deleter> ptr;
++ ptr.reset(QVariant::PrivateShared::create(size, align));
++ return ptr;
++ }
++
++ template <typename F> static QVariant::PrivateShared *
++ customConstructShared(size_t size, size_t align, F &&construct)
++ {
++ auto ptr = customConstructSharedImpl(size, align);
++ construct(ptr->data());
++ return ptr.release();
++ }
++
++ inline int QVariant::PrivateShared::computeOffset(PrivateShared *ps, size_t align)
++ {
++ if (align < sizeof(PrivateShared))
++ return sizeof(PrivateShared);
++ return int(((quintptr(ps) + sizeof(PrivateShared) + align - 1) & ~(align - 1)) - quintptr(ps));
++ }
++
++ inline size_t QVariant::PrivateShared::computeAllocationSize(size_t size, size_t align)
++ {
++ size += sizeof(PrivateShared);
++ if (align > sizeof(PrivateShared)) {
++ // The alignment is larger than the alignment we can guarantee for the pointer
++ // directly following PrivateShared, so we need to allocate some additional
++ // memory to be able to fit the object into the available memory with suitable
++ // alignment.
++ size += align - sizeof(PrivateShared);
++ }
++ return size;
++ }
++
++ inline QVariant::PrivateShared *QVariant::PrivateShared::create(size_t size, size_t align)
++ {
++ size = computeAllocationSize(size, align);
++ void *data = operator new(size);
++ auto *ps = new (data) QVariant::PrivateShared();
++ ps->offset = computeOffset(ps, align);
++ return ps;
++ }
++
++ inline void QVariant::PrivateShared::free(PrivateShared *p)
++ {
++ p->~PrivateShared();
++ operator delete(p);
++ }
++
++ inline QVariant::Private::Private(const QtPrivate::QMetaTypeInterface *iface) noexcept
++ : is_shared(false), is_null(false), packedType(quintptr(iface) >> 2)
++ {
++ Q_ASSERT((quintptr(iface) & 0x3) == 0);
++ }
++
++ template <typename TT>
++ QVariant::Private::Private(std::in_place_t, TT &&t)
++ : is_shared{!CanUseInternalSpace<q20::remove_cvref_t<TT>>},
++ is_null{std::is_null_pointer_v<std::remove_reference_t<TT>>}
++ {
++ using T = q20::remove_cvref_t<TT>;
++ // confirm noexceptness
++ constexpr bool isNothrowQVariantConstructible = noexcept(QVariant{std::forward<TT>(t)});
++ constexpr bool isNothrowConstructible = std::is_nothrow_constructible_v<T, TT>;
++ constexpr bool isNothrowAssignable = std::is_nothrow_assignable_v<T&, TT>;
++
++ const QtPrivate::QMetaTypeInterface *iface = QtPrivate::qMetaTypeInterfaceForType<T>();
++ Q_ASSERT((quintptr(iface) & 0x3) == 0);
++ packedType = quintptr(iface) >> 2;
++
++ if constexpr (CanUseInternalSpace<T>) {
++ static_assert(isNothrowQVariantConstructible == isNothrowConstructible);
++ static_assert(isNothrowQVariantConstructible == isNothrowAssignable);
++ new (data.data) T(std::forward<TT>(t));
++ } else {
++ static_assert(!isNothrowQVariantConstructible); // we allocate memory, even if T doesn't
++ data.shared = customConstructShared(sizeof(T), alignof(T), [&t](void *where) {
++ new (where) T(std::forward<TT>(t));
++ });
++ }
++ }
++
++ QT_END_NAMESPACE
++
++ #endif // QVARIANT_P_H