mfbt/Compiler.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 /* Various compiler checks. */
   8
   9 #ifndef mozilla_Compiler_h
  10 #define mozilla_Compiler_h
  11
  12 #define MOZ_IS_GCC 0
  13 #define MOS_IS_MSVC 0
  14
  15 #if !defined(__clang__) && defined(__GNUC__)
  16
  17 #  undef MOZ_IS_GCC
  18 #  define MOZ_IS_GCC 1
  19    /*
  20     * This macro should simplify gcc version checking. For example, to check
  21     * for gcc 4.5.1 or later, check `#if MOZ_GCC_VERSION_AT_LEAST(4, 5, 1)`.
  22     */
  23 #  define MOZ_GCC_VERSION_AT_LEAST(major, minor, patchlevel)          \
  24      ((__GNUC__ * 10000 + __GNUC_MINOR__ * 100 + __GNUC_PATCHLEVEL__) \
  25       >= ((major) * 10000 + (minor) * 100 + (patchlevel)))
  26 #  if !MOZ_GCC_VERSION_AT_LEAST(4, 4, 0)
  27 #    error "mfbt (and Gecko) require at least gcc 4.4 to build."
  28 #  endif
  29
  30 #elif defined(_MSC_VER)
  31
  32 #  undef MOZ_IS_MSVC
  33 #  define MOZ_IS_MSVC 1
  34    /*
  35     * This macro should simplify MSVC version checking. For example, to check
  36     * for VC10 or later, check `#ifdef MOZ_MSVC_VERSION_AT_LEAST(10)`.
  37     */
  38 #  define MOZ_MSVC_VERSION_AT_LEAST(version) \
  39      (version == 10 ? _MSC_VER >= 1600 : \
  40      (version == 11 ? _MSC_VER >= 1700 : \
  41      (version == 12 ? _MSC_VER >= 1800 : \
  42      (version == 13 ? _MSC_VER >= 1900 : \
  43       0))))
  44 #  if !MOZ_MSVC_VERSION_AT_LEAST(10)
  45 #    error "mfbt (and Gecko) require at least MSVC 2010 RTM to build."
  46 #  endif
  47
  48 #endif
  49
  50 /*
  51  * The situation with standard libraries is a lot worse than with compilers,
  52  * particularly as clang and gcc could end up using one of three or so standard
  53  * libraries, and they may not be up-to-snuff with newer C++11 versions. To
  54  * detect the library, we're going to include cstddef (which is a small header
  55  * which will be transitively included by everybody else at some point) to grab
  56  * the version macros and deduce macros from there.
  57  */
  58 #ifdef __cplusplus
  59 #  include <cstddef>
  60 #  ifdef _STLPORT_MAJOR
  61 #    define MOZ_USING_STLPORT 1
  62 #    define MOZ_STLPORT_VERSION_AT_LEAST(major, minor, patch) \
  63        (_STLPORT_VERSION >= ((major) << 8 | (minor) << 4 | (patch)))
  64 #  elif defined(_LIBCPP_VERSION)
  65    /*
  66     * libc++, unfortunately, doesn't appear to have useful versioning macros.
  67     * Hopefully, the recommendations of N3694 with respect to standard libraries
  68     * will get applied instead and we won't need to worry about version numbers
  69     * here.
  70     */
  71 #    define MOZ_USING_LIBCXX 1
  72 #  elif defined(__GLIBCXX__)
  73 #    define MOZ_USING_LIBSTDCXX 1
  74    /*
  75     * libstdc++ is also annoying and doesn't give us useful versioning macros
  76     * for the library. If we're using gcc, then assume that libstdc++ matches
  77     * the compiler version. If we're using clang, we're going to have to fake
  78     * major/minor combinations by looking for newly-defined config macros.
  79     */
  80 #    if MOZ_IS_GCC
  81 #      define MOZ_LIBSTDCXX_VERSION_AT_LEAST(major, minor, patch) \
  82           MOZ_GCC_VERSION_AT_LEAST(major, minor, patch)
  83 #    elif defined(_GLIBCXX_THROW_OR_ABORT)
  84 #      define MOZ_LIBSTDCXX_VERSION_AT_LEAST(major, minor, patch) \
  85           ((major) < 4 || ((major) == 4 && (minor) <= 8))
  86 #    elif defined(_GLIBCXX_NOEXCEPT)
  87 #      define MOZ_LIBSTDCXX_VERSION_AT_LEAST(major, minor, patch) \
  88           ((major) < 4 || ((major) == 4 && (minor) <= 7))
  89 #    elif defined(_GLIBCXX_USE_DEPRECATED)
  90 #      define MOZ_LIBSTDCXX_VERSION_AT_LEAST(major, minor, patch) \
  91           ((major) < 4 || ((major) == 4 && (minor) <= 6))
  92 #    elif defined(_GLIBCXX_PSEUDO_VISIBILITY)
  93 #      define MOZ_LIBSTDCXX_VERSION_AT_LEAST(major, minor, patch) \
  94           ((major) < 4 || ((major) == 4 && (minor) <= 5))
  95 #    elif defined(_GLIBCXX_BEGIN_EXTERN_C)
  96 #      define MOZ_LIBSTDCXX_VERSION_AT_LEAST(major, minor, patch) \
  97           ((major) < 4 || ((major) == 4 && (minor) <= 4))
  98 #    elif defined(_GLIBCXX_VISIBILITY_ATTR)
  99 #      define MOZ_LIBSTDCXX_VERSION_AT_LEAST(major, minor, patch) \
 100           ((major) < 4 || ((major) == 4 && (minor) <= 3))
 101 #    elif defined(_GLIBCXX_VISIBILITY)
 102 #      define MOZ_LIBSTDCXX_VERSION_AT_LEAST(major, minor, patch) \
 103           ((major) < 4 || ((major) == 4 && (minor) <= 2))
 104 #    else
 105 #      error "Your version of libstdc++ is unknown to us and is likely too old."
 106 #    endif
 107 #  endif
 108
 109    // Flesh out the defines for everyone else
 110 #  ifndef MOZ_USING_STLPORT
 111 #    define MOZ_USING_STLPORT 0
 112 #    define MOZ_STLPORT_VERSION_AT_LEAST(major, minor, patch) 0
 113 #  endif
 114 #  ifndef MOZ_USING_LIBCXX
 115 #    define MOZ_USING_LIBCXX 0
 116 #  endif
 117 #  ifndef MOZ_USING_LIBSTDCXX
 118 #    define MOZ_USING_LIBSTDCXX 0
 119 #    define MOZ_LIBSTDCXX_VERSION_AT_LEAST(major, minor, patch) 0
 120 #  endif
 121 #endif /* __cplusplus */
 122
 123 #endif /* mozilla_Compiler_h */