xref: /third_party/ffmpeg/libavutil/attributes.h (revision cabdff1a)
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) || defined(__clang__)
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 */
174