diff options
Diffstat (limited to 'src/corelib/global/qendian_p.h')
| -rw-r--r-- | src/corelib/global/qendian_p.h | 273 |
1 files changed, 171 insertions, 102 deletions
diff --git a/src/corelib/global/qendian_p.h b/src/corelib/global/qendian_p.h index c830e65b54..8d96eba60c 100644 --- a/src/corelib/global/qendian_p.h +++ b/src/corelib/global/qendian_p.h @@ -1,41 +1,5 @@ -/**************************************************************************** -** -** Copyright (C) 2017 The Qt Company Ltd. -** Contact: https://www.qt.io/licensing/ -** -** This file is part of the QtCore module of the Qt Toolkit. -** -** $QT_BEGIN_LICENSE:LGPL$ -** Commercial License Usage -** Licensees holding valid commercial Qt licenses may use this file in -** accordance with the commercial license agreement provided with the -** Software or, alternatively, in accordance with the terms contained in -** a written agreement between you and The Qt Company. For licensing terms -** and conditions see https://www.qt.io/terms-conditions. For further -** information use the contact form at https://www.qt.io/contact-us. -** -** GNU Lesser General Public License Usage -** Alternatively, this file may be used under the terms of the GNU Lesser -** General Public License version 3 as published by the Free Software -** Foundation and appearing in the file LICENSE.LGPL3 included in the -** packaging of this file. Please review the following information to -** ensure the GNU Lesser General Public License version 3 requirements -** will be met: https://www.gnu.org/licenses/lgpl-3.0.html. -** -** GNU General Public License Usage -** Alternatively, this file may be used under the terms of the GNU -** General Public License version 2.0 or (at your option) the GNU General -** Public license version 3 or any later version approved by the KDE Free -** Qt Foundation. The licenses are as published by the Free Software -** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3 -** included in the packaging of this file. Please review the following -** information to ensure the GNU General Public License requirements will -** be met: https://www.gnu.org/licenses/gpl-2.0.html and -** https://www.gnu.org/licenses/gpl-3.0.html. -** -** $QT_END_LICENSE$ -** -****************************************************************************/ +// Copyright (C) 2020 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 #ifndef QENDIAN_P_H #define QENDIAN_P_H @@ -52,90 +16,195 @@ // #include <QtCore/qendian.h> +#include <QtCore/private/qglobal_p.h> QT_BEGIN_NAMESPACE -// Note if using multiple of these bitfields in a union; the underlying storage type must -// match. Since we always use an unsigned storage type, unsigned and signed versions may -// be used together, but different bit-widths may not. -template<class S, int pos, int width> -class QSpecialIntegerBitfield +enum class QSpecialIntegerBitfieldInitializer {}; +constexpr QSpecialIntegerBitfieldInitializer QSpecialIntegerBitfieldZero{}; + +template<class S> +class QSpecialIntegerStorage +{ +public: + using UnsignedStorageType = std::make_unsigned_t<typename S::StorageType>; + + constexpr QSpecialIntegerStorage() = default; + constexpr QSpecialIntegerStorage(QSpecialIntegerBitfieldInitializer) : val(0) {} + constexpr QSpecialIntegerStorage(UnsignedStorageType initial) : val(initial) {} + + UnsignedStorageType val; +}; + +template<class S, int pos, int width, class T = typename S::StorageType> +class QSpecialIntegerAccessor; + +template<class S, int pos, int width, class T = typename S::StorageType> +class QSpecialIntegerConstAccessor { -protected: - typedef typename S::StorageType T; - typedef typename std::make_unsigned<T>::type UT; + Q_DISABLE_COPY_MOVE(QSpecialIntegerConstAccessor) +public: + using Storage = const QSpecialIntegerStorage<S>; + using Type = T; + using UnsignedType = std::make_unsigned_t<T>; - static Q_DECL_CONSTEXPR UT mask() + operator Type() const noexcept { - return ((UT(1) << width) - 1) << pos; + if constexpr (std::is_signed_v<Type>) { + UnsignedType i = S::fromSpecial(storage->val); + i <<= (sizeof(Type) * 8) - width - pos; + Type t = Type(i); + t >>= (sizeof(Type) * 8) - width; + return t; + } + return (S::fromSpecial(storage->val) & mask()) >> pos; } + + bool operator!() const noexcept { return !(storage->val & S::toSpecial(mask())); } + + static constexpr UnsignedType mask() noexcept + { + if constexpr (width == sizeof(UnsignedType) * 8) { + static_assert(pos == 0); + return ~UnsignedType(0); + } else { + return ((UnsignedType(1) << width) - 1) << pos; + } + } + +private: + template<class Storage, typename... Accessors> + friend class QSpecialIntegerBitfieldUnion; + friend class QSpecialIntegerAccessor<S, pos, width, T>; + + explicit QSpecialIntegerConstAccessor(Storage *storage) : storage(storage) {} + + friend bool operator==(const QSpecialIntegerConstAccessor<S, pos, width, T> &i, + const QSpecialIntegerConstAccessor<S, pos, width, T> &j) noexcept + { + return ((i.storage->val ^ j.storage->val) & S::toSpecial(mask())) == 0; + } + + friend bool operator!=(const QSpecialIntegerConstAccessor<S, pos, width, T> &i, + const QSpecialIntegerConstAccessor<S, pos, width, T> &j) noexcept + { + return ((i.storage->val ^ j.storage->val) & S::toSpecial(mask())) != 0; + } + + Storage *storage; +}; + +template<class S, int pos, int width, class T> +class QSpecialIntegerAccessor +{ + Q_DISABLE_COPY_MOVE(QSpecialIntegerAccessor) public: - // FIXME: val is public until qtdeclarative is fixed to not access it directly. - UT val; + using Const = QSpecialIntegerConstAccessor<S, pos, width, T>; + using Storage = QSpecialIntegerStorage<S>; + using Type = T; + using UnsignedType = std::make_unsigned_t<T>; - QSpecialIntegerBitfield &operator =(T t) + QSpecialIntegerAccessor &operator=(Type t) { - UT i = S::fromSpecial(val); - i &= ~mask(); - i |= (UT(t) << pos) & mask(); - val = S::toSpecial(i); + UnsignedType i = S::fromSpecial(storage->val); + i &= ~Const::mask(); + i |= (UnsignedType(t) << pos) & Const::mask(); + storage->val = S::toSpecial(i); return *this; } - operator T() const + + operator Const() { return Const(storage); } + +private: + template<class Storage, typename... Accessors> + friend class QSpecialIntegerBitfieldUnion; + + explicit QSpecialIntegerAccessor(Storage *storage) : storage(storage) {} + + Storage *storage; +}; + +template<class S, typename... Accessors> +class QSpecialIntegerBitfieldUnion +{ +public: + constexpr QSpecialIntegerBitfieldUnion() = default; + constexpr QSpecialIntegerBitfieldUnion(QSpecialIntegerBitfieldInitializer initial) + : storage(initial) + {} + + constexpr QSpecialIntegerBitfieldUnion( + typename QSpecialIntegerStorage<S>::UnsignedStorageType initial) + : storage(initial) + {} + + template<typename A> + void set(typename A::Type value) { - if (std::is_signed<T>::value) { - UT i = S::fromSpecial(val); - i <<= (sizeof(T) * 8) - width - pos; - T t = T(i); - t >>= (sizeof(T) * 8) - width; - return t; - } - return (S::fromSpecial(val) & mask()) >> pos; + member<A>() = value; + } + + template<typename A> + typename A::Type get() const + { + return member<A>(); + } + + typename QSpecialIntegerStorage<S>::UnsignedStorageType data() const + { + return storage.val; + } + +private: + template<typename A> + static constexpr bool isAccessor = std::disjunction_v<std::is_same<A, Accessors>...>; + + template<typename A> + A member() + { + static_assert(isAccessor<A>); + return A(&storage); + } + + template<typename A> + typename A::Const member() const + { + static_assert(isAccessor<A>); + return typename A::Const(&storage); } - bool operator !() const { return !(val & S::toSpecial(mask())); } - bool operator ==(QSpecialIntegerBitfield<S, pos, width> i) const - { return ((val ^ i.val) & S::toSpecial(mask())) == 0; } - bool operator !=(QSpecialIntegerBitfield<S, pos, width> i) const - { return ((val ^ i.val) & S::toSpecial(mask())) != 0; } - - QSpecialIntegerBitfield &operator +=(T i) - { return (*this = (T(*this) + i)); } - QSpecialIntegerBitfield &operator -=(T i) - { return (*this = (T(*this) - i)); } - QSpecialIntegerBitfield &operator *=(T i) - { return (*this = (T(*this) * i)); } - QSpecialIntegerBitfield &operator /=(T i) - { return (*this = (T(*this) / i)); } - QSpecialIntegerBitfield &operator %=(T i) - { return (*this = (T(*this) % i)); } - QSpecialIntegerBitfield &operator |=(T i) - { return (*this = (T(*this) | i)); } - QSpecialIntegerBitfield &operator &=(T i) - { return (*this = (T(*this) & i)); } - QSpecialIntegerBitfield &operator ^=(T i) - { return (*this = (T(*this) ^ i)); } - QSpecialIntegerBitfield &operator >>=(T i) - { return (*this = (T(*this) >> i)); } - QSpecialIntegerBitfield &operator <<=(T i) - { return (*this = (T(*this) << i)); } + QSpecialIntegerStorage<S> storage; }; -template<typename T, int pos, int width> -using QLEIntegerBitfield = QSpecialIntegerBitfield<QLittleEndianStorageType<T>, pos, width>; +template<typename T, typename... Accessors> +using QLEIntegerBitfieldUnion + = QSpecialIntegerBitfieldUnion<QLittleEndianStorageType<T>, Accessors...>; -template<typename T, int pos, int width> -using QBEIntegerBitfield = QSpecialIntegerBitfield<QBigEndianStorageType<T>, pos, width>; +template<typename T, typename... Accessors> +using QBEIntegerBitfieldUnion + = QSpecialIntegerBitfieldUnion<QBigEndianStorageType<T>, Accessors...>; -template<int pos, int width> -using qint32_le_bitfield = QLEIntegerBitfield<int, pos, width>; -template<int pos, int width> -using quint32_le_bitfield = QLEIntegerBitfield<uint, pos, width>; -template<int pos, int width> -using qint32_be_bitfield = QBEIntegerBitfield<int, pos, width>; -template<int pos, int width> -using quint32_be_bitfield = QBEIntegerBitfield<uint, pos, width>; +template<typename... Accessors> +using qint32_le_bitfield_union = QLEIntegerBitfieldUnion<int, Accessors...>; +template<typename... Accessors> +using quint32_le_bitfield_union = QLEIntegerBitfieldUnion<uint, Accessors...>; +template<typename... Accessors> +using qint32_be_bitfield_union = QBEIntegerBitfieldUnion<int, Accessors...>; +template<typename... Accessors> +using quint32_be_bitfield_union = QBEIntegerBitfieldUnion<uint, Accessors...>; +template<int pos, int width, typename T = int> +using qint32_le_bitfield_member + = QSpecialIntegerAccessor<QLittleEndianStorageType<int>, pos, width, T>; +template<int pos, int width, typename T = uint> +using quint32_le_bitfield_member + = QSpecialIntegerAccessor<QLittleEndianStorageType<uint>, pos, width, T>; +template<int pos, int width, typename T = int> +using qint32_be_bitfield_member + = QSpecialIntegerAccessor<QBigEndianStorageType<int>, pos, width, T>; +template<int pos, int width, typename T = uint> +using quint32_be_bitfield_member + = QSpecialIntegerAccessor<QBigEndianStorageType<uint>, pos, width, T>; QT_END_NAMESPACE |