summaryrefslogtreecommitdiffstats
path: root/tdecore/kdemacros.h.cmake
blob: f48f518f69ca1f135f2cba2672a69c18d545fd0d (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
/* This file is part of the KDE libraries
    Copyright (c) 2002-2003 KDE Team

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Library General Public
    License as published by the Free Software Foundation; either
    version 2 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Library General Public License for more details.

    You should have received a copy of the GNU Library General Public License
    along with this library; see the file COPYING.LIB.  If not, write to
    the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
    Boston, MA 02110-1301, USA.
*/

#ifndef _KDE_MACROS_H_
#define _KDE_MACROS_H_

/* Set by configure */
#cmakedefine __TDE_HAVE_TDEHWLIB 1
#cmakedefine __KDE_HAVE_GCC_VISIBILITY 1

/**
 * The TDE_NO_EXPORT macro marks the symbol of the given variable 
 * to be hidden. A hidden symbol is stripped during the linking step, 
 * so it can't be used from outside the resulting library, which is similar
 * to static. However, static limits the visibility to the current 
 * compilation unit. hidden symbols can still be used in multiple compilation
 * units.
 *
 * \code
 * int TDE_NO_EXPORT foo;
 * int TDE_EXPORT bar;
 * \end
 */

#ifdef __KDE_HAVE_GCC_VISIBILITY
#define TDE_NO_EXPORT __attribute__ ((visibility("hidden")))
#define TDE_EXPORT __attribute__ ((visibility("default")))
#elif defined(TQ_WS_WIN)
#define TDE_NO_EXPORT
#define TDE_EXPORT __declspec(dllexport)
#else
#define TDE_NO_EXPORT
#define TDE_EXPORT
#endif

#define KDE_NO_EXPORT TDE_NO_EXPORT
#define KDE_EXPORT TDE_EXPORT

/**
 * KDE_Q_EXPORT_PLUGIN is a workaround for Qt not being able to
 * cope with symbol visibility.
 */
#define KDE_Q_EXPORT_PLUGIN(PLUGIN) \
  TQ_EXTERN_C TDE_EXPORT const char* qt_ucm_query_verification_data(); \
  TQ_EXTERN_C TDE_EXPORT TQUnknownInterface* ucm_instantiate(); \
  TQ_EXPORT_PLUGIN(PLUGIN)

/**
 * The KDE_PACKED can be used to hint the compiler that a particular
 * structure or class should not contain unnecessary paddings. 
 */

#ifdef __GNUC__
#define KDE_PACKED __attribute__((__packed__))
#else
#define KDE_PACKED
#endif

/**
 * The KDE_DEPRECATED macro can be used to trigger compile-time warnings
 * with newer compilers when deprecated functions are used.
 *
 * For non-inline functions, the macro gets inserted at the very end of the
 * function declaration, right before the semicolon:
 *
 * \code
 * DeprecatedConstructor() KDE_DEPRECATED;
 * void deprecatedFunctionA() KDE_DEPRECATED;
 * int deprecatedFunctionB() const KDE_DEPRECATED;
 * \endcode
 *
 * Functions which are implemented inline are handled differently: for them,
 * the KDE_DEPRECATED macro is inserted at the front, right before the return
 * type, but after "static" or "virtual":
 *
 * \code
 * KDE_DEPRECATED void deprecatedInlineFunctionA() { .. }
 * virtual KDE_DEPRECATED int deprecatedInlineFunctionB() { .. }
 * static KDE_DEPRECATED bool deprecatedInlineFunctionC() { .. }
 * \end
 *
 * You can also mark whole structs or classes as deprecated, by inserting the
 * KDE_DEPRECATED macro after the struct/class keyword, but before the
 * name of the struct/class:
 *
 * \code
 * class KDE_DEPRECATED DeprecatedClass { };
 * struct KDE_DEPRECATED DeprecatedStruct { };
 * \endcode
 *
 * \note
 * It does not make much sense to use the KDE_DEPRECATED keyword for a Qt signal;
 * this is because usually get called by the class which they belong to,
 * and one'd assume that a class author doesn't use deprecated methods of his
 * own class. The only exception to this are signals which are connected to
 * other signals; they get invoked from moc-generated code. In any case, 
 * printing a warning message in either case is not useful.
 * For slots, it can make sense (since slots can be invoked directly) but be
 * aware that if the slots get triggered by a signal, the will get called from
 * moc code as well and thus the warnings are useless.
 *
 * \par
 * Also note that it is not possible to use KDE_DEPRECATED for classes which
 * use the k_dcop keyword (to indicate a DCOP interface declaration); this is
 * because the dcopidl program would choke on the unexpected declaration
 * syntax.
 */

#ifndef KDE_DEPRECATED
#if __GNUC__ - 0 > 3 || (__GNUC__ - 0 == 3 && __GNUC_MINOR__ - 0 >= 2)
  /* gcc >= 3.2 */
# define KDE_DEPRECATED __attribute__ ((deprecated))
#elif defined(_MSC_VER) && (_MSC_VER >= 1300)
  /* msvc >= 7 */
# define KDE_DEPRECATED __declspec(deprecated)
#else
# define KDE_DEPRECATED
#endif
#endif

/**
 * The KDE_ISLIKELY macro tags a boolean expression as likely to evaluate to
 * 'true'. When used in an if ( ) statement, it gives a hint to the compiler
 * that the following codeblock is likely to get executed. Providing this
 * information helps the compiler to optimize the code for better performance.
 * Using the macro has an insignificant code size or runtime memory footprint impact.
 * The code semantics is not affected.
 *
 * \note
 * Providing wrong information ( like marking a condition that almost never
 * passes as 'likely' ) will cause a significant runtime slowdown. Therefore only
 * use it for cases where you can be sure about the odds of the expression to pass
 * in all cases ( independent from e.g. user configuration ).
 *
 * \par
 * The KDE_ISUNLIKELY macro tags an expression as unlikely evaluating to 'true'. 
 *
 * \note
 * Do NOT use ( !KDE_ISLIKELY(foo) ) as an replacement for KDE_ISUNLIKELY !
 *
 * \code
 * if ( KDE_ISUNLIKELY( testsomething() ) )
 *     abort();     // assume its unlikely that the application aborts
 * \endcode
 */
#if __GNUC__ - 0 >= 3
# define KDE_ISLIKELY( x )    __builtin_expect(!!(x),1)
# define KDE_ISUNLIKELY( x )  __builtin_expect(!!(x),0)
#else
# define KDE_ISLIKELY( x )   ( x )
# define KDE_ISUNLIKELY( x )  ( x )
#endif

/**
 * This macro, and it's friends going up to 10 reserve a fixed number of virtual
 * functions in a class.  Because adding virtual functions to a class changes the
 * size of the vtable, adding virtual functions to a class breaks binary
 * compatibility.  However, by using this macro, and decrementing it as new
 * virtual methods are added, binary compatibility can still be preserved.
 *
 * \note The added functions must be added to the header at the same location
 * as the macro; changing the order of virtual functions in a header is also
 * binary incompatible as it breaks the layout of the vtable.
 */

#define RESERVE_VIRTUAL_1 \
    virtual void reservedVirtual1() {}
#define RESERVE_VIRTUAL_2 \
    virtual void reservedVirtual2() {} \
    RESERVE_VIRTUAL_1
#define RESERVE_VIRTUAL_3 \
    virtual void reservedVirtual3() {} \
    RESERVE_VIRTUAL_2
#define RESERVE_VIRTUAL_4 \
    virtual void reservedVirtual4() {} \
    RESERVE_VIRTUAL_3
#define RESERVE_VIRTUAL_5 \
    virtual void reservedVirtual5() {} \
    RESERVE_VIRTUAL_4
#define RESERVE_VIRTUAL_6 \
    virtual void reservedVirtual6() {} \
    RESERVE_VIRTUAL_5
#define RESERVE_VIRTUAL_7 \
    virtual void reservedVirtual7() {} \
    RESERVE_VIRTUAL_6
#define RESERVE_VIRTUAL_8 \
    virtual void reservedVirtual8() {} \
    RESERVE_VIRTUAL_7
#define RESERVE_VIRTUAL_9 \
    virtual void reservedVirtual9() {} \
    RESERVE_VIRTUAL_8
#define RESERVE_VIRTUAL_10 \
    virtual void reservedVirtual10() {} \
    RESERVE_VIRTUAL_9

/**
 * The KDE_WEAK_SYMBOL macro can be used to tell the compiler that
 * a particular function should be a weak symbol (that e.g. may be overriden
 * in another library, -Bdirect will not bind this symbol directly)
 */

#ifdef __GNUC__
#define KDE_WEAK_SYMBOL __attribute__((__weak__))
#else
#define KDE_WEAK_SYMBOL
#endif

#endif /* _KDE_MACROS_H_ */