FFmpeg
attributes.h
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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 # define AV_GCC_VERSION_AT_MOST(x,y) (__GNUC__ < (x) || __GNUC__ == (x) && __GNUC_MINOR__ <= (y))
32 #else
33 # define AV_GCC_VERSION_AT_LEAST(x,y) 0
34 # define AV_GCC_VERSION_AT_MOST(x,y) 0
35 #endif
36 
37 #ifdef __has_builtin
38 # define AV_HAS_BUILTIN(x) __has_builtin(x)
39 #else
40 # define AV_HAS_BUILTIN(x) 0
41 #endif
42 
43 #ifndef av_always_inline
44 #if AV_GCC_VERSION_AT_LEAST(3,1)
45 # define av_always_inline __attribute__((always_inline)) inline
46 #elif defined(_MSC_VER)
47 # define av_always_inline __forceinline
48 #else
49 # define av_always_inline inline
50 #endif
51 #endif
52 
53 #ifndef av_extern_inline
54 #if defined(__ICL) && __ICL >= 1210 || defined(__GNUC_STDC_INLINE__)
55 # define av_extern_inline extern inline
56 #else
57 # define av_extern_inline inline
58 #endif
59 #endif
60 
61 #if AV_GCC_VERSION_AT_LEAST(3,4)
62 # define av_warn_unused_result __attribute__((warn_unused_result))
63 #else
64 # define av_warn_unused_result
65 #endif
66 
67 #if AV_GCC_VERSION_AT_LEAST(3,1)
68 # define av_noinline __attribute__((noinline))
69 #elif defined(_MSC_VER)
70 # define av_noinline __declspec(noinline)
71 #else
72 # define av_noinline
73 #endif
74 
75 #if AV_GCC_VERSION_AT_LEAST(3,1) || defined(__clang__)
76 # define av_pure __attribute__((pure))
77 #else
78 # define av_pure
79 #endif
80 
81 #if AV_GCC_VERSION_AT_LEAST(2,6) || defined(__clang__)
82 # define av_const __attribute__((const))
83 #else
84 # define av_const
85 #endif
86 
87 #if AV_GCC_VERSION_AT_LEAST(4,3) || defined(__clang__)
88 # define av_cold __attribute__((cold))
89 #else
90 # define av_cold
91 #endif
92 
93 #if AV_GCC_VERSION_AT_LEAST(4,1) && !defined(__llvm__)
94 # define av_flatten __attribute__((flatten))
95 #else
96 # define av_flatten
97 #endif
98 
99 #if AV_GCC_VERSION_AT_LEAST(3,1)
100 # define attribute_deprecated __attribute__((deprecated))
101 #elif defined(_MSC_VER)
102 # define attribute_deprecated __declspec(deprecated)
103 #else
104 # define attribute_deprecated
105 #endif
106 
107 /**
108  * Disable warnings about deprecated features
109  * This is useful for sections of code kept for backward compatibility and
110  * scheduled for removal.
111  */
112 #ifndef AV_NOWARN_DEPRECATED
113 #if AV_GCC_VERSION_AT_LEAST(4,6)
114 # define AV_NOWARN_DEPRECATED(code) \
115  _Pragma("GCC diagnostic push") \
116  _Pragma("GCC diagnostic ignored \"-Wdeprecated-declarations\"") \
117  code \
118  _Pragma("GCC diagnostic pop")
119 #elif defined(_MSC_VER)
120 # define AV_NOWARN_DEPRECATED(code) \
121  __pragma(warning(push)) \
122  __pragma(warning(disable : 4996)) \
123  code; \
124  __pragma(warning(pop))
125 #else
126 # define AV_NOWARN_DEPRECATED(code) code
127 #endif
128 #endif
129 
130 #if defined(__GNUC__) || defined(__clang__)
131 # define av_unused __attribute__((unused))
132 #else
133 # define av_unused
134 #endif
135 
136 /**
137  * Mark a variable as used and prevent the compiler from optimizing it
138  * away. This is useful for variables accessed only from inline
139  * assembler without the compiler being aware.
140  */
141 #if AV_GCC_VERSION_AT_LEAST(3,1) || defined(__clang__)
142 # define av_used __attribute__((used))
143 #else
144 # define av_used
145 #endif
146 
147 #if AV_GCC_VERSION_AT_LEAST(3,3) || defined(__clang__)
148 # define av_alias __attribute__((may_alias))
149 #else
150 # define av_alias
151 #endif
152 
153 #if (defined(__GNUC__) || defined(__clang__)) && !defined(__INTEL_COMPILER)
154 # define av_uninit(x) x=x
155 #else
156 # define av_uninit(x) x
157 #endif
158 
159 #if defined(__GNUC__) || defined(__clang__)
160 # define av_builtin_constant_p __builtin_constant_p
161 # define av_printf_format(fmtpos, attrpos) __attribute__((__format__(__printf__, fmtpos, attrpos)))
162 #else
163 # define av_builtin_constant_p(x) 0
164 # define av_printf_format(fmtpos, attrpos)
165 #endif
166 
167 #if AV_GCC_VERSION_AT_LEAST(2,5) || defined(__clang__)
168 # define av_noreturn __attribute__((noreturn))
169 #else
170 # define av_noreturn
171 #endif
172 
173 #endif /* AVUTIL_ATTRIBUTES_H */
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