ffmpeg/libavutil/attributes.h

   1 /*
   2  * copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
   3  *
   4  * This file is part of FFmpeg.
   5  *
   6  * FFmpeg is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * FFmpeg is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with FFmpeg; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  19  */
  20
  21 /**
  22  * @file
  23  * Macro definitions for various function/variable attributes
  24  */
  25
  26 #ifndef AVUTIL_ATTRIBUTES_H
  27 #define AVUTIL_ATTRIBUTES_H
  28
  29 #ifdef __GNUC__
  30 #    define AV_GCC_VERSION_AT_LEAST(x,y) (__GNUC__ > x || __GNUC__ == x && __GNUC_MINOR__ >= y)
  31 #else
  32 #    define AV_GCC_VERSION_AT_LEAST(x,y) 0
  33 #endif
  34
  35 #ifndef av_always_inline
  36 #if AV_GCC_VERSION_AT_LEAST(3,1)
  37 #    define av_always_inline __attribute__((always_inline)) inline
  38 #elif defined(_MSC_VER)
  39 #    define av_always_inline __forceinline
  40 #else
  41 #    define av_always_inline inline
  42 #endif
  43 #endif
  44
  45 #ifndef av_extern_inline
  46 #if defined(__ICL) && __ICL >= 1210 || defined(__GNUC_STDC_INLINE__)
  47 #    define av_extern_inline extern inline
  48 #else
  49 #    define av_extern_inline inline
  50 #endif
  51 #endif
  52
  53 #if AV_GCC_VERSION_AT_LEAST(3,1)
  54 #    define av_noinline __attribute__((noinline))
  55 #elif defined(_MSC_VER)
  56 #    define av_noinline __declspec(noinline)
  57 #else
  58 #    define av_noinline
  59 #endif
  60
  61 #if AV_GCC_VERSION_AT_LEAST(3,1)
  62 #    define av_pure __attribute__((pure))
  63 #else
  64 #    define av_pure
  65 #endif
  66
  67 #if AV_GCC_VERSION_AT_LEAST(2,6)
  68 #    define av_const __attribute__((const))
  69 #else
  70 #    define av_const
  71 #endif
  72
  73 #if AV_GCC_VERSION_AT_LEAST(4,3)
  74 #    define av_cold __attribute__((cold))
  75 #else
  76 #    define av_cold
  77 #endif
  78
  79 #if AV_GCC_VERSION_AT_LEAST(4,1) && !defined(__llvm__)
  80 #    define av_flatten __attribute__((flatten))
  81 #else
  82 #    define av_flatten
  83 #endif
  84
  85 #if AV_GCC_VERSION_AT_LEAST(3,1)
  86 #    define attribute_deprecated __attribute__((deprecated))
  87 #elif defined(_MSC_VER)
  88 #    define attribute_deprecated __declspec(deprecated)
  89 #else
  90 #    define attribute_deprecated
  91 #endif
  92
  93 /**
  94  * Disable warnings about deprecated features
  95  * This is useful for sections of code kept for backward compatibility and
  96  * scheduled for removal.
  97  */
  98 #ifndef AV_NOWARN_DEPRECATED
  99 #if AV_GCC_VERSION_AT_LEAST(4,6)
 100 #    define AV_NOWARN_DEPRECATED(code) \
 101         _Pragma("GCC diagnostic push") \
 102         _Pragma("GCC diagnostic ignored \"-Wdeprecated-declarations\"") \
 103         code \
 104         _Pragma("GCC diagnostic pop")
 105 #elif defined(_MSC_VER)
 106 #    define AV_NOWARN_DEPRECATED(code) \
 107         __pragma(warning(push)) \
 108         __pragma(warning(disable : 4996)) \
 109         code; \
 110         __pragma(warning(pop))
 111 #else
 112 #    define AV_NOWARN_DEPRECATED(code) code
 113 #endif
 114 #endif
 115
 116
 117 #if defined(__GNUC__)
 118 #    define av_unused __attribute__((unused))
 119 #else
 120 #    define av_unused
 121 #endif
 122
 123 /**
 124  * Mark a variable as used and prevent the compiler from optimizing it
 125  * away.  This is useful for variables accessed only from inline
 126  * assembler without the compiler being aware.
 127  */
 128 #if AV_GCC_VERSION_AT_LEAST(3,1)
 129 #    define av_used __attribute__((used))
 130 #else
 131 #    define av_used
 132 #endif
 133
 134 #if AV_GCC_VERSION_AT_LEAST(3,3)
 135 #   define av_alias __attribute__((may_alias))
 136 #else
 137 #   define av_alias
 138 #endif
 139
 140 #if defined(__GNUC__) && !defined(__INTEL_COMPILER) && !defined(__clang__)
 141 #    define av_uninit(x) x=x
 142 #else
 143 #    define av_uninit(x) x
 144 #endif
 145
 146 #ifdef __GNUC__
 147 #    define av_builtin_constant_p __builtin_constant_p
 148 #    define av_printf_format(fmtpos, attrpos) __attribute__((__format__(__printf__, fmtpos, attrpos)))
 149 #else
 150 #    define av_builtin_constant_p(x) 0
 151 #    define av_printf_format(fmtpos, attrpos)
 152 #endif
 153
 154 #if AV_GCC_VERSION_AT_LEAST(2,5)
 155 #    define av_noreturn __attribute__((noreturn))
 156 #else
 157 #    define av_noreturn
 158 #endif
 159
 160 #endif /* AVUTIL_ATTRIBUTES_H */