ceph/src/boost/boost/system/detail/generic_category.hpp

   1 // Implementation details of generic_error_category
   2 //
   3 // Copyright 2018 Peter Dimov
   4 //
   5 // Distributed under the Boost Software License, Version 1.0. (See accompanying
   6 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   7 //
   8 // See library home page at http://www.boost.org/libs/system
   9
  10 #include <cstring>
  11
  12 namespace boost
  13 {
  14
  15 namespace system
  16 {
  17
  18 namespace detail
  19 {
  20
  21 #if defined(__GLIBC__)
  22
  23 // glibc has two incompatible strerror_r definitions
  24
  25 inline char const * strerror_r_helper( char const * r, char const * ) BOOST_NOEXCEPT
  26 {
  27     return r;
  28 }
  29
  30 inline char const * strerror_r_helper( int r, char const * buffer ) BOOST_NOEXCEPT
  31 {
  32     return r == 0? buffer: "Unknown error";
  33 }
  34
  35 inline char const * generic_error_category_message( int ev, char * buffer, std::size_t len ) BOOST_NOEXCEPT
  36 {
  37     return strerror_r_helper( strerror_r( ev, buffer, len ), buffer );
  38 }
  39
  40 inline std::string generic_error_category_message( int ev )
  41 {
  42     char buffer[ 128 ];
  43     return generic_error_category_message( ev, buffer, sizeof( buffer ) );
  44 }
  45
  46 #else
  47
  48 // std::strerror is thread-safe on everything else, incl. Windows
  49
  50 # if defined( BOOST_MSVC )
  51 #  pragma warning( push )
  52 #  pragma warning( disable: 4996 )
  53 # elif defined(__clang__) && defined(__has_warning)
  54 #  pragma clang diagnostic push
  55 #  if __has_warning("-Wdeprecated-declarations")
  56 #   pragma clang diagnostic ignored "-Wdeprecated-declarations"
  57 #  endif
  58 # endif
  59
  60 inline std::string generic_error_category_message( int ev )
  61 {
  62     char const * m = std::strerror( ev );
  63     return m? m: "Unknown error";
  64 }
  65
  66 inline char const * generic_error_category_message( int ev, char * buffer, std::size_t len ) BOOST_NOEXCEPT
  67 {
  68     if( len == 0 )
  69     {
  70         return buffer;
  71     }
  72
  73     if( len == 1 )
  74     {
  75         buffer[0] = 0;
  76         return buffer;
  77     }
  78
  79     char const * m = std::strerror( ev );
  80
  81     if( m == 0 ) return "Unknown error";
  82
  83     std::strncpy( buffer, m, len - 1 );
  84     buffer[ len-1 ] = 0;
  85
  86     return buffer;
  87 }
  88
  89 # if defined( BOOST_MSVC )
  90 #  pragma warning( pop )
  91 # elif defined(__clang__) && defined(__has_warning)
  92 #  pragma clang diagnostic pop
  93 # endif
  94
  95 #endif
  96
  97 } // namespace detail
  98
  99 } // namespace system
 100
 101 } // namespace boost