include/c99_compat.h

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  16  * of the Software.
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  27
  28 #include "no_extern_c.h"
  29
  30 #ifndef _C99_COMPAT_H_
  31 #define _C99_COMPAT_H_
  32
  33
  34 /*
  35  * MSVC hacks.
  36  */
  37 #if defined(_MSC_VER)
  38
  39 #  if _MSC_VER < 1900
  40 #    error "Microsoft Visual Studio 2015 or higher required"
  41 #  endif
  42
  43    /*
  44     * Visual Studio will complain if we define the `inline` keyword, but
  45     * actually it only supports the keyword on C++.
  46     *
  47     * To avoid this the _ALLOW_KEYWORD_MACROS must be set.
  48     */
  49 #  if !defined(_ALLOW_KEYWORD_MACROS)
  50 #    define _ALLOW_KEYWORD_MACROS
  51 #  endif
  52
  53    /*
  54     * XXX: MSVC has a `__restrict` keyword, but it also has a
  55     * `__declspec(restrict)` modifier, so it is impossible to define a
  56     * `restrict` macro without interfering with the latter.  Furthermore the
  57     * MSVC standard library uses __declspec(restrict) under the _CRTRESTRICT
  58     * macro.  For now resolve this issue by redefining _CRTRESTRICT, but going
  59     * forward we should probably should stop using restrict, especially
  60     * considering that our code does not obbey strict aliasing rules any way.
  61     */
  62 #  include <crtdefs.h>
  63 #  undef _CRTRESTRICT
  64 #  define _CRTRESTRICT
  65 #endif
  66
  67
  68 /*
  69  * C99 inline keyword
  70  */
  71 #ifndef inline
  72 #  ifdef __cplusplus
  73      /* C++ supports inline keyword */
  74 #  elif defined(__GNUC__)
  75 #    define inline __inline__
  76 #  elif defined(_MSC_VER)
  77 #    define inline __inline
  78 #  elif defined(__ICL)
  79 #    define inline __inline
  80 #  elif defined(__INTEL_COMPILER)
  81      /* Intel compiler supports inline keyword */
  82 #  elif defined(__WATCOMC__) && (__WATCOMC__ >= 1100)
  83 #    define inline __inline
  84 #  elif (__STDC_VERSION__ >= 199901L)
  85      /* C99 supports inline keyword */
  86 #  else
  87 #    define inline
  88 #  endif
  89 #endif
  90
  91
  92 /*
  93  * C99 restrict keyword
  94  *
  95  * See also:
  96  * - http://cellperformance.beyond3d.com/articles/2006/05/demystifying-the-restrict-keyword.html
  97  */
  98 #ifndef restrict
  99 #  if (__STDC_VERSION__ >= 199901L) && !defined(__cplusplus)
 100      /* C99 */
 101 #  elif defined(__GNUC__)
 102 #    define restrict __restrict__
 103 #  elif defined(_MSC_VER)
 104 #    define restrict __restrict
 105 #  else
 106 #    define restrict /* */
 107 #  endif
 108 #endif
 109
 110
 111 /*
 112  * C99 __func__ macro
 113  */
 114 #ifndef __func__
 115 #  if (__STDC_VERSION__ >= 199901L)
 116      /* C99 */
 117 #  elif defined(__GNUC__)
 118 #    define __func__ __FUNCTION__
 119 #  elif defined(_MSC_VER)
 120 #    define __func__ __FUNCTION__
 121 #  else
 122 #    define __func__ "<unknown>"
 123 #  endif
 124 #endif
 125
 126
 127 /* Simple test case for debugging */
 128 #if 0
 129 static inline const char *
 130 test_c99_compat_h(const void * restrict a,
 131                   const void * restrict b)
 132 {
 133    return __func__;
 134 }
 135 #endif
 136
 137
 138 /* Fallback definitions, for scons which doesn't auto-detect these things. */
 139 #ifdef HAVE_SCONS
 140
 141 #  ifndef _WIN32
 142 #    define HAVE_PTHREAD
 143 #    define HAVE_POSIX_MEMALIGN
 144 #  endif
 145
 146 #  ifdef __GNUC__
 147 #    if __GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 2)
 148 #      error "GCC version 4.2 or higher required"
 149 #    endif
 150
 151      /* https://gcc.gnu.org/onlinedocs/gcc-4.2.4/gcc/Other-Builtins.html */
 152 #    define HAVE___BUILTIN_CLZ 1
 153 #    define HAVE___BUILTIN_CLZLL 1
 154 #    define HAVE___BUILTIN_CTZ 1
 155 #    define HAVE___BUILTIN_EXPECT 1
 156 #    define HAVE___BUILTIN_FFS 1
 157 #    define HAVE___BUILTIN_FFSLL 1
 158 #    define HAVE___BUILTIN_POPCOUNT 1
 159 #    define HAVE___BUILTIN_POPCOUNTLL 1
 160      /* https://gcc.gnu.org/onlinedocs/gcc-4.2.4/gcc/Function-Attributes.html */
 161 #    define HAVE_FUNC_ATTRIBUTE_FLATTEN 1
 162 #    define HAVE_FUNC_ATTRIBUTE_UNUSED 1
 163 #    define HAVE_FUNC_ATTRIBUTE_FORMAT 1
 164 #    define HAVE_FUNC_ATTRIBUTE_PACKED 1
 165 #    define HAVE_FUNC_ATTRIBUTE_ALIAS 1
 166 #    define HAVE_FUNC_ATTRIBUTE_NORETURN 1
 167
 168 #    if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 3)
 169        /* https://gcc.gnu.org/onlinedocs/gcc-4.3.6/gcc/Other-Builtins.html */
 170 #      define HAVE___BUILTIN_BSWAP32 1
 171 #      define HAVE___BUILTIN_BSWAP64 1
 172 #    endif
 173
 174 #    if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 5)
 175 #      define HAVE___BUILTIN_UNREACHABLE 1
 176 #    endif
 177
 178 #  endif /* __GNUC__ */
 179
 180 #endif /* HAVE_SCONS */
 181
 182
 183 #endif /* _C99_COMPAT_H_ */