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

   1 // <system_error> implementation file
   2
   3 // Copyright (C) 2007-2015 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     virtual string
  45     message(int i) const
  46     {
  47       // XXX locale issues: how does one get or set loc.
  48       // _GLIBCXX_HAVE_STRERROR_L, strerror_l(i, cloc)
  49       return string(strerror(i));
  50     }
  51   };
  52
  53   struct system_error_category : public std::error_category
  54   {
  55     virtual const char*
  56     name() const noexcept
  57     { return "system"; }
  58
  59     virtual string
  60     message(int i) const
  61     {
  62       // XXX locale issues: how does one get or set loc.
  63       // _GLIBCXX_HAVE_STRERROR_L, strerror_l(i, cloc)
  64       return string(strerror(i));
  65     }
  66   };
  67
  68   const generic_error_category generic_category_instance{};
  69   const system_error_category system_category_instance{};
  70 }
  71
  72 namespace std _GLIBCXX_VISIBILITY(default)
  73 {
  74 _GLIBCXX_BEGIN_NAMESPACE_VERSION
  75
  76   error_category::~error_category() noexcept = default;
  77
  78   const error_category&
  79   _V2::system_category() noexcept { return system_category_instance; }
  80
  81   const error_category&
  82   _V2::generic_category() noexcept { return generic_category_instance; }
  83
  84   system_error::~system_error() noexcept = default;
  85
  86   error_condition
  87   error_category::default_error_condition(int __i) const noexcept
  88   { return error_condition(__i, *this); }
  89
  90   bool
  91   error_category::equivalent(int __i,
  92                              const error_condition& __cond) const noexcept
  93   { return default_error_condition(__i) == __cond; }
  94
  95   bool
  96   error_category::equivalent(const error_code& __code, int __i) const noexcept
  97   { return *this == __code.category() && __code.value() == __i; }
  98
  99   error_condition
 100   error_code::default_error_condition() const noexcept
 101   { return category().default_error_condition(value()); }
 102
 103 #if _GLIBCXX_USE_CXX11_ABI
 104   // Return error_category::message() as a COW string
 105   __cow_string
 106   error_category::_M_message(int i) const
 107   {
 108     string msg = this->message(i);
 109     return {msg.c_str(), msg.length()};
 110   }
 111 #endif
 112
 113 #if _GLIBCXX_USE_DUAL_ABI
 114   // Redefine __sso_string so that we can define and export its members
 115   // in terms of the SSO std::string.
 116   struct __sso_string
 117   {
 118     struct __str
 119     {
 120       const char* _M_p;
 121       size_t _M_string_length;
 122       char _M_local_buf[16];
 123     };
 124
 125     union {
 126       __str _M_s;
 127       char _M_bytes[sizeof(_M_s)];
 128       std::string _M_str;
 129     };
 130
 131     __sso_string();
 132     __sso_string(const std::string& s);
 133     __sso_string(const char*, size_t n);
 134     __sso_string(const __sso_string&) noexcept;
 135     __sso_string& operator=(const __sso_string&) noexcept;
 136     ~__sso_string();
 137     __sso_string(__sso_string&&) noexcept;
 138     __sso_string& operator=(__sso_string&&) noexcept;
 139   };
 140
 141   __sso_string::__sso_string() : _M_str() { }
 142
 143 #if _GLIBCXX_USE_CXX11_ABI
 144   static_assert(sizeof(__sso_string) == sizeof(std::string),
 145                 "sizeof(std::string) has changed");
 146   static_assert(alignof(__sso_string) == alignof(std::string),
 147                 "alignof(std::string) has changed");
 148
 149   // This constructor is defined in src/c++11/cow-stdexcept.cc for COW strings
 150   __sso_string::__sso_string(const std::string& s) : _M_str(s) { }
 151 #endif
 152
 153   __sso_string::__sso_string(const char* s, size_t n) : _M_str(s, n) { }
 154
 155   __sso_string::__sso_string(const __sso_string& s) noexcept
 156   : _M_str(s._M_str) { }
 157
 158   __sso_string&
 159   __sso_string::operator=(const __sso_string& s) noexcept
 160   {
 161     _M_str = s._M_str;
 162     return *this;
 163   }
 164
 165   __sso_string::~__sso_string() { _M_str.~basic_string(); }
 166
 167   __sso_string::__sso_string(__sso_string&& s) noexcept
 168   : _M_str(std::move(s._M_str)) { }
 169
 170   __sso_string&
 171   __sso_string::operator=(__sso_string&& s) noexcept
 172   {
 173     _M_str = std::move(s._M_str);
 174     return *this;
 175   }
 176 #endif // _GLIBCXX_USE_DUAL_ABI
 177
 178 _GLIBCXX_END_NAMESPACE_VERSION
 179 } // namespace