summaryrefslogtreecommitdiffstats
path: root/src/corelib/global/qtypeinfo.h
blob: 30be47296e882c51270fa2e793efd24d8037239d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
/****************************************************************************
**
** Copyright (C) 2016 The Qt Company Ltd.
** Copyright (C) 2016 Intel Corporation.
** 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.
**
** $QT_END_LICENSE$
**
****************************************************************************/

#include <QtCore/qglobal.h>

#ifndef QTYPEINFO_H
#define QTYPEINFO_H

QT_BEGIN_NAMESPACE

/*
   QTypeInfo     - type trait functionality
*/

template <typename T>
static constexpr bool qIsRelocatable()
{
#if defined(Q_CC_CLANG) || !defined(Q_CC_GNU) || Q_CC_GNU >= 501
    return std::is_trivially_copyable<T>::value && std::is_trivially_destructible<T>::value;
#else
    return std::is_enum<T>::value || std::is_integral<T>::value;
#endif
}

template <typename T>
static constexpr bool qIsTrivial()
{
#if defined(Q_CC_CLANG) || !defined(Q_CC_GNU) || Q_CC_GNU >= 501
    return std::is_trivial<T>::value;
#else
    return std::is_enum<T>::value || std::is_integral<T>::value;
#endif
}

/*
  The catch-all template.
*/

template <typename T>
class QTypeInfo
{
public:
    enum {
        isSpecialized = std::is_enum<T>::value, // don't require every enum to be marked manually
        isPointer = false,
        isIntegral = std::is_integral<T>::value,
        isComplex = !qIsTrivial<T>(),
        isStatic = true,
        isRelocatable = qIsRelocatable<T>(),
        isLarge = (sizeof(T)>sizeof(void*)),
        isDummy = false, //### Qt6: remove
        sizeOf = sizeof(T)
    };
};

template<>
class QTypeInfo<void>
{
public:
    enum {
        isSpecialized = true,
        isPointer = false,
        isIntegral = false,
        isComplex = false,
        isStatic = false,
        isRelocatable = false,
        isLarge = false,
        isDummy = false,
        sizeOf = 0
    };
};

template <typename T>
class QTypeInfo<T*>
{
public:
    enum {
        isSpecialized = true,
        isPointer = true,
        isIntegral = false,
        isComplex = false,
        isStatic = false,
        isRelocatable = true,
        isLarge = false,
        isDummy = false,
        sizeOf = sizeof(T*)
    };
};

/*!
    \class QTypeInfoQuery
    \inmodule QtCore
    \internal
    \brief QTypeInfoQuery is used to query the values of a given QTypeInfo<T>

    We use it because there may be some QTypeInfo<T> specializations in user
    code that don't provide certain flags that we added after Qt 5.0. They are:
    \list
      \li isRelocatable: defaults to !isStatic
    \endlist

    DO NOT specialize this class elsewhere.
*/
// apply defaults for a generic QTypeInfo<T> that didn't provide the new values
template <typename T, typename = void>
struct QTypeInfoQuery : public QTypeInfo<T>
{
    enum { isRelocatable = !QTypeInfo<T>::isStatic };
};

// if QTypeInfo<T>::isRelocatable exists, use it
template <typename T>
struct QTypeInfoQuery<T, typename std::enable_if<QTypeInfo<T>::isRelocatable || true>::type> : public QTypeInfo<T>
{};

/*!
    \class QTypeInfoMerger
    \inmodule QtCore
    \internal

    \brief QTypeInfoMerger merges the QTypeInfo flags of T1, T2... and presents them
    as a QTypeInfo<T> would do.

    Let's assume that we have a simple set of structs:

    \snippet code/src_corelib_global_qglobal.cpp 50

    To create a proper QTypeInfo specialization for A struct, we have to check
    all sub-components; B, C and D, then take the lowest common denominator and call
    Q_DECLARE_TYPEINFO with the resulting flags. An easier and less fragile approach is to
    use QTypeInfoMerger, which does that automatically. So struct A would have
    the following QTypeInfo definition:

    \snippet code/src_corelib_global_qglobal.cpp 51
*/
template <class T, class T1, class T2 = T1, class T3 = T1, class T4 = T1>
class QTypeInfoMerger
{
public:
    enum {
        isSpecialized = true,
        isComplex = QTypeInfoQuery<T1>::isComplex || QTypeInfoQuery<T2>::isComplex
                    || QTypeInfoQuery<T3>::isComplex || QTypeInfoQuery<T4>::isComplex,
        isStatic = QTypeInfoQuery<T1>::isStatic || QTypeInfoQuery<T2>::isStatic
                    || QTypeInfoQuery<T3>::isStatic || QTypeInfoQuery<T4>::isStatic,
        isRelocatable = QTypeInfoQuery<T1>::isRelocatable && QTypeInfoQuery<T2>::isRelocatable
                    && QTypeInfoQuery<T3>::isRelocatable && QTypeInfoQuery<T4>::isRelocatable,
        isLarge = sizeof(T) > sizeof(void*),
        isPointer = false,
        isIntegral = false,
        isDummy = false,
        sizeOf = sizeof(T)
    };
};

#define Q_DECLARE_MOVABLE_CONTAINER(CONTAINER) \
template <typename T> class CONTAINER; \
template <typename T> \
class QTypeInfo< CONTAINER<T> > \
{ \
public: \
    enum { \
        isSpecialized = true, \
        isPointer = false, \
        isIntegral = false, \
        isComplex = true, \
        isRelocatable = true, \
        isStatic = false, \
        isLarge = (sizeof(CONTAINER<T>) > sizeof(void*)), \
        isDummy = false, \
        sizeOf = sizeof(CONTAINER<T>) \
    }; \
}

Q_DECLARE_MOVABLE_CONTAINER(QList);
Q_DECLARE_MOVABLE_CONTAINER(QVector);
Q_DECLARE_MOVABLE_CONTAINER(QQueue);
Q_DECLARE_MOVABLE_CONTAINER(QStack);
Q_DECLARE_MOVABLE_CONTAINER(QSet);

#undef Q_DECLARE_MOVABLE_CONTAINER

/* These cannot be movable before ### Qt 6, for BC reasons */
#define Q_DECLARE_MOVABLE_CONTAINER(CONTAINER) \
template <typename K, typename V> class CONTAINER; \
template <typename K, typename V> \
class QTypeInfo< CONTAINER<K, V> > \
{ \
public: \
    enum { \
        isSpecialized = true, \
        isPointer = false, \
        isIntegral = false, \
        isComplex = true, \
        isStatic = (QT_VERSION < QT_VERSION_CHECK(6, 0, 0)), \
        isRelocatable = true, \
        isLarge = (sizeof(CONTAINER<K, V>) > sizeof(void*)), \
        isDummy = false, \
        sizeOf = sizeof(CONTAINER<K, V>) \
    }; \
}

Q_DECLARE_MOVABLE_CONTAINER(QMap);
Q_DECLARE_MOVABLE_CONTAINER(QMultiMap);
Q_DECLARE_MOVABLE_CONTAINER(QHash);
Q_DECLARE_MOVABLE_CONTAINER(QMultiHash);

#undef Q_DECLARE_MOVABLE_CONTAINER

/*
   Specialize a specific type with:

     Q_DECLARE_TYPEINFO(type, flags);

   where 'type' is the name of the type to specialize and 'flags' is
   logically-OR'ed combination of the flags below.
*/
enum { /* TYPEINFO flags */
    Q_COMPLEX_TYPE = 0,
    Q_PRIMITIVE_TYPE = 0x1,
    Q_STATIC_TYPE = 0,
    Q_MOVABLE_TYPE = 0x2,               // ### Qt6: merge movable and relocatable once QList no longer depends on it
    Q_DUMMY_TYPE = 0x4,
    Q_RELOCATABLE_TYPE = 0x8
};

#define Q_DECLARE_TYPEINFO_BODY(TYPE, FLAGS) \
class QTypeInfo<TYPE > \
{ \
public: \
    enum { \
        isSpecialized = true, \
        isComplex = (((FLAGS) & Q_PRIMITIVE_TYPE) == 0) && !qIsTrivial<TYPE>(), \
        isStatic = (((FLAGS) & (Q_MOVABLE_TYPE | Q_PRIMITIVE_TYPE)) == 0), \
        isRelocatable = !isStatic || ((FLAGS) & Q_RELOCATABLE_TYPE) || qIsRelocatable<TYPE>(), \
        isLarge = (sizeof(TYPE)>sizeof(void*)), \
        isPointer = false, \
        isIntegral = std::is_integral< TYPE >::value, \
        isDummy = (((FLAGS) & Q_DUMMY_TYPE) != 0), \
        sizeOf = sizeof(TYPE) \
    }; \
    static inline const char *name() { return #TYPE; } \
}

#define Q_DECLARE_TYPEINFO(TYPE, FLAGS) \
template<> \
Q_DECLARE_TYPEINFO_BODY(TYPE, FLAGS)

/* Specialize QTypeInfo for QFlags<T> */
template<typename T> class QFlags;
template<typename T>
Q_DECLARE_TYPEINFO_BODY(QFlags<T>, Q_PRIMITIVE_TYPE);

/*
   Specialize a shared type with:

     Q_DECLARE_SHARED(type)

   where 'type' is the name of the type to specialize.  NOTE: shared
   types must define a member-swap, and be defined in the same
   namespace as Qt for this to work.

   If the type was already released without Q_DECLARE_SHARED applied,
   _and_ without an explicit Q_DECLARE_TYPEINFO(type, Q_MOVABLE_TYPE),
   then use Q_DECLARE_SHARED_NOT_MOVABLE_UNTIL_QT6(type) to mark the
   type shared (incl. swap()), without marking it movable (which
   would change the memory layout of QList, a BiC change.
*/

#define Q_DECLARE_SHARED_IMPL(TYPE, FLAGS) \
Q_DECLARE_TYPEINFO(TYPE, FLAGS); \
inline void swap(TYPE &value1, TYPE &value2) \
    noexcept(noexcept(value1.swap(value2))) \
{ value1.swap(value2); }
#define Q_DECLARE_SHARED(TYPE) Q_DECLARE_SHARED_IMPL(TYPE, Q_MOVABLE_TYPE)
#define Q_DECLARE_SHARED_NOT_MOVABLE_UNTIL_QT6(TYPE) \
                               Q_DECLARE_SHARED_IMPL(TYPE, QT_VERSION >= QT_VERSION_CHECK(6,0,0) ? Q_MOVABLE_TYPE : Q_RELOCATABLE_TYPE)

/*
   QTypeInfo primitive specializations
*/
Q_DECLARE_TYPEINFO(bool, Q_PRIMITIVE_TYPE);
Q_DECLARE_TYPEINFO(char, Q_PRIMITIVE_TYPE);
Q_DECLARE_TYPEINFO(signed char, Q_PRIMITIVE_TYPE);
Q_DECLARE_TYPEINFO(uchar, Q_PRIMITIVE_TYPE);
Q_DECLARE_TYPEINFO(short, Q_PRIMITIVE_TYPE);
Q_DECLARE_TYPEINFO(ushort, Q_PRIMITIVE_TYPE);
Q_DECLARE_TYPEINFO(int, Q_PRIMITIVE_TYPE);
Q_DECLARE_TYPEINFO(uint, Q_PRIMITIVE_TYPE);
Q_DECLARE_TYPEINFO(long, Q_PRIMITIVE_TYPE);
Q_DECLARE_TYPEINFO(ulong, Q_PRIMITIVE_TYPE);
Q_DECLARE_TYPEINFO(qint64, Q_PRIMITIVE_TYPE);
Q_DECLARE_TYPEINFO(quint64, Q_PRIMITIVE_TYPE);
Q_DECLARE_TYPEINFO(float, Q_PRIMITIVE_TYPE);
Q_DECLARE_TYPEINFO(double, Q_PRIMITIVE_TYPE);

#if QT_VERSION >= QT_VERSION_CHECK(6,0,0)
// ### Qt 6: remove the other branch
// This was required so that QList<T> for these types allocates out of the array storage
Q_DECLARE_TYPEINFO(long double, Q_PRIMITIVE_TYPE);
#  ifdef Q_COMPILER_UNICODE_STRINGS
Q_DECLARE_TYPEINFO(char16_t, Q_PRIMITIVE_TYPE);
Q_DECLARE_TYPEINFO(char32_t, Q_PRIMITIVE_TYPE);
#  endif
#  if !defined(Q_CC_MSVC) || defined(_NATIVE_WCHAR_T_DEFINED)
Q_DECLARE_TYPEINFO(wchar_t, Q_PRIMITIVE_TYPE);
#  endif
#else
#  ifndef Q_OS_DARWIN
Q_DECLARE_TYPEINFO(long double, Q_PRIMITIVE_TYPE);
#  else
Q_DECLARE_TYPEINFO(long double, Q_RELOCATABLE_TYPE);
#  endif
#  ifdef Q_COMPILER_UNICODE_STRINGS
Q_DECLARE_TYPEINFO(char16_t, Q_RELOCATABLE_TYPE);
Q_DECLARE_TYPEINFO(char32_t, Q_RELOCATABLE_TYPE);
#  endif
#  if !defined(Q_CC_MSVC) || defined(_NATIVE_WCHAR_T_DEFINED)
Q_DECLARE_TYPEINFO(wchar_t, Q_RELOCATABLE_TYPE);
#  endif
#endif // Qt 6

QT_END_NAMESPACE
#endif // QTYPEINFO_H