attributes: disable flatten on llvm/clang
[libav.git] / 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 #elif defined(_MSC_VER)
46 # define av_noinline __declspec(noinline)
47 #else
48 # define av_noinline
49 #endif
50
51 #if AV_GCC_VERSION_AT_LEAST(3,1)
52 # define av_pure __attribute__((pure))
53 #else
54 # define av_pure
55 #endif
56
57 #if AV_GCC_VERSION_AT_LEAST(2,6)
58 # define av_const __attribute__((const))
59 #else
60 # define av_const
61 #endif
62
63 #if AV_GCC_VERSION_AT_LEAST(4,3)
64 # define av_cold __attribute__((cold))
65 #else
66 # define av_cold
67 #endif
68
69 #if AV_GCC_VERSION_AT_LEAST(4,1) && !defined(__llvm__)
70 # define av_flatten __attribute__((flatten))
71 #else
72 # define av_flatten
73 #endif
74
75 #if AV_GCC_VERSION_AT_LEAST(3,1)
76 # define attribute_deprecated __attribute__((deprecated))
77 #elif defined(_MSC_VER)
78 # define attribute_deprecated __declspec(deprecated)
79 #else
80 # define attribute_deprecated
81 #endif
82
83 #if defined(__GNUC__)
84 # define av_unused __attribute__((unused))
85 #else
86 # define av_unused
87 #endif
88
89 /**
90 * Mark a variable as used and prevent the compiler from optimizing it
91 * away. This is useful for variables accessed only from inline
92 * assembler without the compiler being aware.
93 */
94 #if AV_GCC_VERSION_AT_LEAST(3,1)
95 # define av_used __attribute__((used))
96 #else
97 # define av_used
98 #endif
99
100 #if AV_GCC_VERSION_AT_LEAST(3,3)
101 # define av_alias __attribute__((may_alias))
102 #else
103 # define av_alias
104 #endif
105
106 #if defined(__GNUC__) && !defined(__ICC)
107 # define av_uninit(x) x=x
108 #else
109 # define av_uninit(x) x
110 #endif
111
112 #ifdef __GNUC__
113 # define av_builtin_constant_p __builtin_constant_p
114 # define av_printf_format(fmtpos, attrpos) __attribute__((__format__(__printf__, fmtpos, attrpos)))
115 #else
116 # define av_builtin_constant_p(x) 0
117 # define av_printf_format(fmtpos, attrpos)
118 #endif
119
120 #if AV_GCC_VERSION_AT_LEAST(2,5)
121 # define av_noreturn __attribute__((noreturn))
122 #else
123 # define av_noreturn
124 #endif
125
126 #endif /* AVUTIL_ATTRIBUTES_H */