libavutil/attributes.h

   1 /*
   2  * copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
   3  *
   4  * This file is part of Libav.
   5  *
   6  * Libav 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  * Libav 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 Libav; 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 #if AV_GCC_VERSION_AT_LEAST(3,1)
  36 #    define av_always_inline __attribute__((always_inline)) inline
  37 #elif defined(_MSC_VER)
  38 #    define av_always_inline __forceinline
  39 #else
  40 #    define av_always_inline inline
  41 #endif
  42
  43 #if AV_GCC_VERSION_AT_LEAST(3,1)
  44 #    define av_noinline __attribute__((noinline))
  45 #else
  46 #    define av_noinline
  47 #endif
  48
  49 #if AV_GCC_VERSION_AT_LEAST(3,1)
  50 #    define av_pure __attribute__((pure))
  51 #else
  52 #    define av_pure
  53 #endif
  54
  55 #if AV_GCC_VERSION_AT_LEAST(2,6)
  56 #    define av_const __attribute__((const))
  57 #else
  58 #    define av_const
  59 #endif
  60
  61 #if AV_GCC_VERSION_AT_LEAST(4,3)
  62 #    define av_cold __attribute__((cold))
  63 #else
  64 #    define av_cold
  65 #endif
  66
  67 #if AV_GCC_VERSION_AT_LEAST(4,1)
  68 #    define av_flatten __attribute__((flatten))
  69 #else
  70 #    define av_flatten
  71 #endif
  72
  73 #if AV_GCC_VERSION_AT_LEAST(3,1)
  74 #    define attribute_deprecated __attribute__((deprecated))
  75 #else
  76 #    define attribute_deprecated
  77 #endif
  78
  79 #if defined(__GNUC__)
  80 #    define av_unused __attribute__((unused))
  81 #else
  82 #    define av_unused
  83 #endif
  84
  85 /**
  86  * Mark a variable as used and prevent the compiler from optimizing it
  87  * away.  This is useful for variables accessed only from inline
  88  * assembler without the compiler being aware.
  89  */
  90 #if AV_GCC_VERSION_AT_LEAST(3,1)
  91 #    define av_used __attribute__((used))
  92 #else
  93 #    define av_used
  94 #endif
  95
  96 #if AV_GCC_VERSION_AT_LEAST(3,3)
  97 #   define av_alias __attribute__((may_alias))
  98 #else
  99 #   define av_alias
 100 #endif
 101
 102 #if defined(__GNUC__) && !defined(__ICC)
 103 #    define av_uninit(x) x=x
 104 #else
 105 #    define av_uninit(x) x
 106 #endif
 107
 108 #ifdef __GNUC__
 109 #    define av_builtin_constant_p __builtin_constant_p
 110 #    define av_printf_format(fmtpos, attrpos) __attribute__((__format__(__printf__, fmtpos, attrpos)))
 111 #else
 112 #    define av_builtin_constant_p(x) 0
 113 #    define av_printf_format(fmtpos, attrpos)
 114 #endif
 115
 116 #if AV_GCC_VERSION_AT_LEAST(2,5)
 117 #    define av_noreturn __attribute__((noreturn))
 118 #else
 119 #    define av_noreturn
 120 #endif
 121
 122 #endif /* AVUTIL_ATTRIBUTES_H */