boost/predef/other/endian.h

   1 /*
   2 Copyright Redshift Software, Inc. 2013
   3 Distributed under the Boost Software License, Version 1.0.
   4 (See accompanying file LICENSE_1_0.txt or copy at
   5 http://www.boost.org/LICENSE_1_0.txt)
   6 */
   7
   8 #ifndef BOOST_PREDEF_ENDIAN_H
   9 #define BOOST_PREDEF_ENDIAN_H
  10
  11 #include <boost/predef/version_number.h>
  12 #include <boost/predef/make.h>
  13 #include <boost/predef/library/c/gnu.h>
  14 #include <boost/predef/os/macos.h>
  15 #include <boost/predef/os/bsd.h>
  16
  17 /*`
  18 [heading `BOOST_ENDIAN_*`]
  19
  20 Detection of endian memory ordering. There are four defined macros
  21 in this header that define the various generally possible endian
  22 memory orderings:
  23
  24 * `BOOST_ENDIAN_BIG_BYTE`, byte-swapped big-endian.
  25 * `BOOST_ENDIAN_BIG_WORD`, word-swapped big-endian.
  26 * `BOOST_ENDIAN_LITTLE_BYTE`, byte-swapped little-endian.
  27 * `BOOST_ENDIAN_LITTLE_WORD`, word-swapped little-endian.
  28
  29 The detection is conservative in that it only identifies endianness
  30 that it knows for certain. In particular bi-endianness is not
  31 indicated as is it not practically possible to determine the
  32 endianness from anything but an operating system provided
  33 header. And the currently known headers do not define that
  34 programatic bi-endianness is available.
  35
  36 This implementation is a compilation of various publicly available
  37 information and acquired knowledge:
  38
  39 # The indispensable documentation of "Pre-defined Compiler Macros"
  40   [@http://sourceforge.net/p/predef/wiki/Endianness Endianness].
  41 # The various endian specifications available in the
  42   [@http://wikipedia.org/ Wikipedia] computer architecture pages.
  43 # Generally available searches for headers that define endianness.
  44  */
  45
  46 #define BOOST_ENDIAN_BIG_BYTE BOOST_VERSION_NUMBER_NOT_AVAILABLE
  47 #define BOOST_ENDIAN_BIG_WORD BOOST_VERSION_NUMBER_NOT_AVAILABLE
  48 #define BOOST_ENDIAN_LITTLE_BYTE BOOST_VERSION_NUMBER_NOT_AVAILABLE
  49 #define BOOST_ENDIAN_LITTLE_WORD BOOST_VERSION_NUMBER_NOT_AVAILABLE
  50
  51 /* GNU libc provides a header defining __BYTE_ORDER, or _BYTE_ORDER.
  52  * And some OSs provide some for of endian header also.
  53  */
  54 #if !BOOST_ENDIAN_BIG_BYTE && !BOOST_ENDIAN_BIG_WORD && \
  55     !BOOST_ENDIAN_LITTLE_BYTE && !BOOST_ENDIAN_LITTLE_WORD
  56 #   if BOOST_LIB_C_GNU
  57 #       include <endian.h>
  58 #   else
  59 #       if BOOST_OS_MACOS
  60 #           include <machine/endian.h>
  61 #       else
  62 #           if BOOST_OS_BSD
  63 #               if BOOST_OS_BSD_OPEN
  64 #                   include <machine/endian.h>
  65 #               else
  66 #                   include <sys/endian.h>
  67 #               endif
  68 #           endif
  69 #       endif
  70 #   endif
  71 #   if defined(__BYTE_ORDER)
  72 #       if (__BYTE_ORDER == __BIG_ENDIAN)
  73 #           undef BOOST_ENDIAN_BIG_BYTE
  74 #           define BOOST_ENDIAN_BIG_BYTE BOOST_VERSION_NUMBER_AVAILABLE
  75 #       endif
  76 #       if (__BYTE_ORDER == __LITTLE_ENDIAN)
  77 #           undef BOOST_ENDIAN_LITTLE_BYTE
  78 #           define BOOST_ENDIAN_LITTLE_BYTE BOOST_VERSION_NUMBER_AVAILABLE
  79 #       endif
  80 #       if (__BYTE_ORDER == __PDP_ENDIAN)
  81 #           undef BOOST_ENDIAN_LITTLE_WORD
  82 #           define BOOST_ENDIAN_LITTLE_WORD BOOST_VERSION_NUMBER_AVAILABLE
  83 #       endif
  84 #   endif
  85 #   if !defined(__BYTE_ORDER) && defined(_BYTE_ORDER)
  86 #       if (_BYTE_ORDER == _BIG_ENDIAN)
  87 #           undef BOOST_ENDIAN_BIG_BYTE
  88 #           define BOOST_ENDIAN_BIG_BYTE BOOST_VERSION_NUMBER_AVAILABLE
  89 #       endif
  90 #       if (_BYTE_ORDER == _LITTLE_ENDIAN)
  91 #           undef BOOST_ENDIAN_LITTLE_BYTE
  92 #           define BOOST_ENDIAN_LITTLE_BYTE BOOST_VERSION_NUMBER_AVAILABLE
  93 #       endif
  94 #       if (_BYTE_ORDER == _PDP_ENDIAN)
  95 #           undef BOOST_ENDIAN_LITTLE_WORD
  96 #           define BOOST_ENDIAN_LITTLE_WORD BOOST_VERSION_NUMBER_AVAILABLE
  97 #       endif
  98 #   endif
  99 #endif
 100
 101 /* Built-in byte-swpped big-endian macros.
 102  */
 103 #if !BOOST_ENDIAN_BIG_BYTE && !BOOST_ENDIAN_BIG_WORD && \
 104     !BOOST_ENDIAN_LITTLE_BYTE && !BOOST_ENDIAN_LITTLE_WORD
 105 #   if !BOOST_ENDIAN_BIG_BYTE
 106 #       if (defined(__BIG_ENDIAN__) && !defined(__LITTLE_ENDIAN__)) || \
 107             defined(__ARMEB__) || \
 108             defined(__THUMBEB__) || \
 109             defined(__AARCH64EB__) || \
 110             defined(_MIPSEB) || \
 111             defined(__MIPSEB) || \
 112             defined(__MIPSEB__)
 113 #           undef BOOST_ENDIAN_BIG_BYTE
 114 #           define BOOST_ENDIAN_BIG_BYTE BOOST_VERSION_NUMBER_AVAILABLE
 115 #       endif
 116 #   endif
 117 #endif
 118
 119 /* Built-in byte-swpped little-endian macros.
 120  */
 121 #if !BOOST_ENDIAN_BIG_BYTE && !BOOST_ENDIAN_BIG_WORD && \
 122     !BOOST_ENDIAN_LITTLE_BYTE && !BOOST_ENDIAN_LITTLE_WORD
 123 #   if !BOOST_ENDIAN_LITTLE_BYTE
 124 #       if (defined(__LITTLE_ENDIAN__) && !defined(__BIG_ENDIAN__)) || \
 125             defined(__ARMEL__) || \
 126             defined(__THUMBEL__) || \
 127             defined(__AARCH64EL__) || \
 128             defined(_MIPSEL) || \
 129             defined(__MIPSEL) || \
 130             defined(__MIPSEL__)
 131 #           undef BOOST_ENDIAN_LITTLE_BYTE
 132 #           define BOOST_ENDIAN_LITTLE_BYTE BOOST_VERSION_NUMBER_AVAILABLE
 133 #       endif
 134 #   endif
 135 #endif
 136
 137 /* Some architectures are strictly one endianess (as opposed
 138  * the current common bi-endianess).
 139  */
 140 #if !BOOST_ENDIAN_BIG_BYTE && !BOOST_ENDIAN_BIG_WORD && \
 141     !BOOST_ENDIAN_LITTLE_BYTE && !BOOST_ENDIAN_LITTLE_WORD
 142 #   include <boost/predef/architecture.h>
 143 #   if BOOST_ARCH_M68K || \
 144         BOOST_ARCH_PARISK || \
 145         BOOST_ARCH_SYS370 || \
 146         BOOST_ARCH_SYS390 || \
 147         BOOST_ARCH_Z
 148 #       undef BOOST_ENDIAN_BIG_BYTE
 149 #       define BOOST_ENDIAN_BIG_BYTE BOOST_VERSION_NUMBER_AVAILABLE
 150 #   endif
 151 #   if BOOST_ARCH_AMD64 || \
 152         BOOST_ARCH_IA64 || \
 153         BOOST_ARCH_X86 || \
 154         BOOST_ARCH_BLACKFIN
 155 #       undef BOOST_ENDIAN_LITTLE_BYTE
 156 #       define BOOST_ENDIAN_LITTLE_BYTE BOOST_VERSION_NUMBER_AVAILABLE
 157 #   endif
 158 #endif
 159
 160 /* Windows on ARM, if not otherwise detected/specified, is always
 161  * byte-swaped little-endian.
 162  */
 163 #if !BOOST_ENDIAN_BIG_BYTE && !BOOST_ENDIAN_BIG_WORD && \
 164     !BOOST_ENDIAN_LITTLE_BYTE && !BOOST_ENDIAN_LITTLE_WORD
 165 #   if BOOST_ARCH_ARM
 166 #       include <boost/predef/os/windows.h>
 167 #       if BOOST_OS_WINDOWS
 168 #           undef BOOST_ENDIAN_LITTLE_BYTE
 169 #           define BOOST_ENDIAN_LITTLE_BYTE BOOST_VERSION_NUMBER_AVAILABLE
 170 #       endif
 171 #   endif
 172 #endif
 173
 174 #if BOOST_ENDIAN_BIG_BYTE
 175 #   define BOOST_ENDIAN_BIG_BYTE_AVAILABLE
 176 #endif
 177 #if BOOST_ENDIAN_BIG_WORD
 178 #   define BOOST_ENDIAN_BIG_WORD_BYTE_AVAILABLE
 179 #endif
 180 #if BOOST_ENDIAN_LITTLE_BYTE
 181 #   define BOOST_ENDIAN_LITTLE_BYTE_AVAILABLE
 182 #endif
 183 #if BOOST_ENDIAN_LITTLE_WORD
 184 #   define BOOST_ENDIAN_LITTLE_WORD_BYTE_AVAILABLE
 185 #endif
 186
 187 #define BOOST_ENDIAN_BIG_BYTE_NAME "Byte-Swapped Big-Endian"
 188 #define BOOST_ENDIAN_BIG_WORD_NAME "Word-Swapped Big-Endian"
 189 #define BOOST_ENDIAN_LITTLE_BYTE_NAME "Byte-Swapped Little-Endian"
 190 #define BOOST_ENDIAN_LITTLE_WORD_NAME "Word-Swapped Little-Endian"
 191
 192 #include <boost/predef/detail/test.h>
 193 BOOST_PREDEF_DECLARE_TEST(BOOST_ENDIAN_BIG_BYTE,BOOST_ENDIAN_BIG_BYTE_NAME)
 194
 195 #include <boost/predef/detail/test.h>
 196 BOOST_PREDEF_DECLARE_TEST(BOOST_ENDIAN_BIG_WORD,BOOST_ENDIAN_BIG_WORD_NAME)
 197
 198 #include <boost/predef/detail/test.h>
 199 BOOST_PREDEF_DECLARE_TEST(BOOST_ENDIAN_LITTLE_BYTE,BOOST_ENDIAN_LITTLE_BYTE_NAME)
 200
 201 #include <boost/predef/detail/test.h>
 202 BOOST_PREDEF_DECLARE_TEST(BOOST_ENDIAN_LITTLE_WORD,BOOST_ENDIAN_LITTLE_WORD_NAME)
 203
 204
 205 #endif