libstdc++-v3/src/c++11/system_error.cc

   1 // <system_error> implementation file
   2
   3 // Copyright (C) 2007-2016 Free Software Foundation, Inc.
   4 //
   5 // This file is part of the GNU ISO C++ Library.  This library is free
   6 // software; you can redistribute it and/or modify it under the
   7 // terms of the GNU General Public License as published by the
   8 // Free Software Foundation; either version 3, or (at your option)
   9 // any later version.
  10
  11 // This library 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
  14 // GNU General Public License for more details.
  15
  16 // Under Section 7 of GPL version 3, you are granted additional
  17 // permissions described in the GCC Runtime Library Exception, version
  18 // 3.1, as published by the Free Software Foundation.
  19
  20 // You should have received a copy of the GNU General Public License and
  21 // a copy of the GCC Runtime Library Exception along with this program;
  22 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  23 // <http://www.gnu.org/licenses/>.
  24
  25
  26 #define _GLIBCXX_USE_CXX11_ABI 1
  27 #define __sso_string __sso_stringxxx
  28 #include <cstring>
  29 #include <system_error>
  30 #include <bits/functexcept.h>
  31 #include <limits>
  32 #undef __sso_string
  33
  34 namespace
  35 {
  36   using std::string;
  37
  38   struct generic_error_category : public std::error_category
  39   {
  40     virtual const char*
  41     name() const noexcept
  42     { return "generic"; }
  43
  44     _GLIBCXX_DEFAULT_ABI_TAG
  45     virtual string
  46     message(int i) const
  47     {
  48       // XXX locale issues: how does one get or set loc.
  49       // _GLIBCXX_HAVE_STRERROR_L, strerror_l(i, cloc)
  50       return string(strerror(i));
  51     }
  52   };
  53
  54   struct system_error_category : public std::error_category
  55   {
  56     virtual const char*
  57     name() const noexcept
  58     { return "system"; }
  59
  60     _GLIBCXX_DEFAULT_ABI_TAG
  61     virtual string
  62     message(int i) const
  63     {
  64       // XXX locale issues: how does one get or set loc.
  65       // _GLIBCXX_HAVE_STRERROR_L, strerror_l(i, cloc)
  66       return string(strerror(i));
  67     }
  68   };
  69
  70   const generic_error_category generic_category_instance{};
  71   const system_error_category system_category_instance{};
  72 }
  73
  74 namespace std _GLIBCXX_VISIBILITY(default)
  75 {
  76 _GLIBCXX_BEGIN_NAMESPACE_VERSION
  77
  78   error_category::~error_category() noexcept = default;
  79
  80   const error_category&
  81   _V2::system_category() noexcept { return system_category_instance; }
  82
  83   const error_category&
  84   _V2::generic_category() noexcept { return generic_category_instance; }
  85
  86   system_error::~system_error() noexcept = default;
  87
  88   error_condition
  89   error_category::default_error_condition(int __i) const noexcept
  90   { return error_condition(__i, *this); }
  91
  92   bool
  93   error_category::equivalent(int __i,
  94                              const error_condition& __cond) const noexcept
  95   { return default_error_condition(__i) == __cond; }
  96
  97   bool
  98   error_category::equivalent(const error_code& __code, int __i) const noexcept
  99   { return *this == __code.category() && __code.value() == __i; }
 100
 101   error_condition
 102   error_code::default_error_condition() const noexcept
 103   { return category().default_error_condition(value()); }
 104
 105 #if _GLIBCXX_USE_CXX11_ABI
 106   // Return error_category::message() as a COW string
 107   __cow_string
 108   error_category::_M_message(int i) const
 109   {
 110     string msg = this->message(i);
 111     return {msg.c_str(), msg.length()};
 112   }
 113 #endif
 114
 115 #if _GLIBCXX_USE_DUAL_ABI
 116 #pragma GCC diagnostic push
 117 #pragma GCC diagnostic ignored "-Wabi-tag"
 118   // Redefine __sso_string so that we can define and export its members
 119   // in terms of the SSO std::string.
 120   struct __sso_string
 121   {
 122     struct __str
 123     {
 124       const char* _M_p;
 125       size_t _M_string_length;
 126       char _M_local_buf[16];
 127     };
 128
 129     union {
 130       __str _M_s;
 131       char _M_bytes[sizeof(_M_s)];
 132       std::string _M_str;
 133     };
 134
 135     __sso_string();
 136     __sso_string(const std::string& s);
 137     __sso_string(const char*, size_t n);
 138     __sso_string(const __sso_string&) noexcept;
 139     __sso_string& operator=(const __sso_string&) noexcept;
 140     ~__sso_string();
 141     __sso_string(__sso_string&&) noexcept;
 142     __sso_string& operator=(__sso_string&&) noexcept;
 143   };
 144 #pragma GCC diagnostic pop
 145
 146   __sso_string::__sso_string() : _M_str() { }
 147
 148 #if _GLIBCXX_USE_CXX11_ABI
 149   static_assert(sizeof(__sso_string) == sizeof(std::string),
 150                 "sizeof(std::string) has changed");
 151   static_assert(alignof(__sso_string) == alignof(std::string),
 152                 "alignof(std::string) has changed");
 153
 154   // This constructor is defined in src/c++11/cow-stdexcept.cc for COW strings
 155   __sso_string::__sso_string(const std::string& s) : _M_str(s) { }
 156 #endif
 157
 158   __sso_string::__sso_string(const char* s, size_t n) : _M_str(s, n) { }
 159
 160   __sso_string::__sso_string(const __sso_string& s) noexcept
 161   : _M_str(s._M_str) { }
 162
 163   __sso_string&
 164   __sso_string::operator=(const __sso_string& s) noexcept
 165   {
 166     _M_str = s._M_str;
 167     return *this;
 168   }
 169
 170   __sso_string::~__sso_string() { _M_str.~basic_string(); }
 171
 172   __sso_string::__sso_string(__sso_string&& s) noexcept
 173   : _M_str(std::move(s._M_str)) { }
 174
 175   __sso_string&
 176   __sso_string::operator=(__sso_string&& s) noexcept
 177   {
 178     _M_str = std::move(s._M_str);
 179     return *this;
 180   }
 181 #endif // _GLIBCXX_USE_DUAL_ABI
 182
 183 _GLIBCXX_END_NAMESPACE_VERSION
 184 } // namespace