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

   1 // Iostreams base classes -*- C++ -*-
   2
   3 // Copyright (C) 1997-2017 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 // ISO C++ 14882: 27.4  Iostreams base classes
  27 //
  28
  29 // Determines the version of ios_base::failure thrown by __throw_ios_failure.
  30 // If !_GLIBCXX_USE_DUAL_ABI this will get undefined automatically.
  31 #define _GLIBCXX_USE_CXX11_ABI 1
  32
  33 #include <ios>
  34 #include <limits>
  35 #include <bits/functexcept.h>
  36
  37 #ifdef _GLIBCXX_USE_NLS
  38 # include <libintl.h>
  39 # define _(msgid)   gettext (msgid)
  40 #else
  41 # define _(msgid)   (msgid)
  42 #endif
  43
  44 namespace std _GLIBCXX_VISIBILITY(default)
  45 {
  46 _GLIBCXX_BEGIN_NAMESPACE_VERSION
  47
  48   void
  49   __throw_ios_failure(const char* __s __attribute__((unused)))
  50   { _GLIBCXX_THROW_OR_ABORT(ios_base::failure(_(__s))); }
  51
  52   // Definitions for static const members of ios_base.
  53   const ios_base::fmtflags ios_base::boolalpha;
  54   const ios_base::fmtflags ios_base::dec;
  55   const ios_base::fmtflags ios_base::fixed;
  56   const ios_base::fmtflags ios_base::hex;
  57   const ios_base::fmtflags ios_base::internal;
  58   const ios_base::fmtflags ios_base::left;
  59   const ios_base::fmtflags ios_base::oct;
  60   const ios_base::fmtflags ios_base::right;
  61   const ios_base::fmtflags ios_base::scientific;
  62   const ios_base::fmtflags ios_base::showbase;
  63   const ios_base::fmtflags ios_base::showpoint;
  64   const ios_base::fmtflags ios_base::showpos;
  65   const ios_base::fmtflags ios_base::skipws;
  66   const ios_base::fmtflags ios_base::unitbuf;
  67   const ios_base::fmtflags ios_base::uppercase;
  68   const ios_base::fmtflags ios_base::adjustfield;
  69   const ios_base::fmtflags ios_base::basefield;
  70   const ios_base::fmtflags ios_base::floatfield;
  71
  72   const ios_base::iostate ios_base::badbit;
  73   const ios_base::iostate ios_base::eofbit;
  74   const ios_base::iostate ios_base::failbit;
  75   const ios_base::iostate ios_base::goodbit;
  76
  77   const ios_base::openmode ios_base::app;
  78   const ios_base::openmode ios_base::ate;
  79   const ios_base::openmode ios_base::binary;
  80   const ios_base::openmode ios_base::in;
  81   const ios_base::openmode ios_base::out;
  82   const ios_base::openmode ios_base::trunc;
  83
  84   const ios_base::seekdir ios_base::beg;
  85   const ios_base::seekdir ios_base::cur;
  86   const ios_base::seekdir ios_base::end;
  87
  88   _Atomic_word ios_base::Init::_S_refcount;
  89
  90   bool ios_base::Init::_S_synced_with_stdio = true;
  91
  92   ios_base::ios_base() throw()
  93   : _M_precision(), _M_width(), _M_flags(), _M_exception(),
  94   _M_streambuf_state(), _M_callbacks(0), _M_word_zero(),
  95   _M_word_size(_S_local_word_size), _M_word(_M_local_word), _M_ios_locale()
  96   {
  97     // Do nothing: basic_ios::init() does it.
  98     // NB: _M_callbacks and _M_word must be zero for non-initialized
  99     // ios_base to go through ~ios_base gracefully.
 100   }
 101
 102   // 27.4.2.7  ios_base constructors/destructors
 103   ios_base::~ios_base()
 104   {
 105     _M_call_callbacks(erase_event);
 106     _M_dispose_callbacks();
 107     if (_M_word != _M_local_word)
 108       {
 109         delete [] _M_word;
 110         _M_word = 0;
 111       }
 112   }
 113
 114   // 27.4.2.5  ios_base storage functions
 115   int
 116   ios_base::xalloc() throw()
 117   {
 118     // Implementation note: Initialize top to zero to ensure that
 119     // initialization occurs before main() is started.
 120     static _Atomic_word _S_top = 0;
 121     return __gnu_cxx::__exchange_and_add_dispatch(&_S_top, 1) + 4;
 122   }
 123
 124   void
 125   ios_base::register_callback(event_callback __fn, int __index)
 126   { _M_callbacks = new _Callback_list(__fn, __index, _M_callbacks); }
 127
 128   // 27.4.2.5  iword/pword storage
 129   ios_base::_Words&
 130   ios_base::_M_grow_words(int __ix, bool __iword)
 131   {
 132     // Precondition: _M_word_size <= __ix
 133     int __newsize = _S_local_word_size;
 134     _Words* __words = _M_local_word;
 135     if (__ix > _S_local_word_size - 1)
 136       {
 137         if (__ix < numeric_limits<int>::max())
 138           {
 139             __newsize = __ix + 1;
 140             /* We still need to catch bad_alloc even though we use
 141                a nothrow new, because the new-expression can throw
 142                a bad_array_new_length.  */
 143             __try
 144               { __words = new (std::nothrow) _Words[__newsize]; }
 145             __catch(const std::bad_alloc&)
 146               { __words = nullptr; }
 147             if (!__words)
 148               {
 149                 _M_streambuf_state |= badbit;
 150                 if (_M_streambuf_state & _M_exception)
 151                   __throw_ios_failure(__N("ios_base::_M_grow_words "
 152                                           "allocation failed"));
 153                 if (__iword)
 154                   _M_word_zero._M_iword = 0;
 155                 else
 156                   _M_word_zero._M_pword = 0;
 157                 return _M_word_zero;
 158               }
 159             for (int __i = 0; __i < _M_word_size; __i++)
 160               __words[__i] = _M_word[__i];
 161             if (_M_word && _M_word != _M_local_word)
 162               {
 163                 delete [] _M_word;
 164                 _M_word = 0;
 165               }
 166           }
 167         else
 168           {
 169             _M_streambuf_state |= badbit;
 170             if (_M_streambuf_state & _M_exception)
 171               __throw_ios_failure(__N("ios_base::_M_grow_words is not valid"));
 172             if (__iword)
 173               _M_word_zero._M_iword = 0;
 174             else
 175               _M_word_zero._M_pword = 0;
 176             return _M_word_zero;
 177           }
 178       }
 179     _M_word = __words;
 180     _M_word_size = __newsize;
 181     return _M_word[__ix];
 182   }
 183
 184   void
 185   ios_base::_M_call_callbacks(event __e) throw()
 186   {
 187     _Callback_list* __p = _M_callbacks;
 188     while (__p)
 189       {
 190         __try
 191           { (*__p->_M_fn) (__e, *this, __p->_M_index); }
 192         __catch(...)
 193           { }
 194         __p = __p->_M_next;
 195       }
 196   }
 197
 198   void
 199   ios_base::_M_dispose_callbacks(void) throw()
 200   {
 201     _Callback_list* __p = _M_callbacks;
 202     while (__p && __p->_M_remove_reference() == 0)
 203       {
 204         _Callback_list* __next = __p->_M_next;
 205         delete __p;
 206         __p = __next;
 207       }
 208     _M_callbacks = 0;
 209   }
 210
 211   void
 212   ios_base::_M_move(ios_base& __rhs) noexcept
 213   {
 214     _M_precision = __rhs._M_precision;
 215     _M_width = __rhs._M_width;
 216     _M_flags = __rhs._M_flags;
 217     _M_exception = __rhs._M_exception;
 218     _M_streambuf_state = __rhs._M_streambuf_state;
 219     _M_callbacks = std::__exchange(__rhs._M_callbacks, nullptr);
 220     if (_M_word != _M_local_word)
 221        delete[] _M_word;
 222     if (__rhs._M_word == __rhs._M_local_word)
 223      {
 224        _M_word = _M_local_word;
 225        _M_word_size = _S_local_word_size;
 226        for (int __i = 0; __i < _S_local_word_size; __i++)
 227          _M_word[__i] = std::__exchange(__rhs._M_word[__i], {});
 228      }
 229     else
 230      {
 231        _M_word = std::__exchange(__rhs._M_word, __rhs._M_local_word);
 232        _M_word_size
 233          = std::__exchange(__rhs._M_word_size, _S_local_word_size);
 234      }
 235     _M_ios_locale = __rhs._M_ios_locale;
 236   }
 237
 238   void
 239   ios_base::_M_swap(ios_base& __rhs) noexcept
 240   {
 241     std::swap(_M_precision, __rhs._M_precision);
 242     std::swap(_M_width, __rhs._M_width);
 243     std::swap(_M_flags, __rhs._M_flags);
 244     std::swap(_M_exception, __rhs._M_exception);
 245     std::swap(_M_streambuf_state, __rhs._M_streambuf_state);
 246     std::swap(_M_callbacks, __rhs._M_callbacks);
 247     const bool __lhs_local = _M_word == _M_local_word;
 248     const bool __rhs_local = __rhs._M_word == __rhs._M_local_word;
 249     if (__lhs_local && __rhs_local)
 250      std::swap(_M_local_word, __rhs._M_local_word); // array swap
 251     else
 252      {
 253        if (!__lhs_local && !__rhs_local)
 254          std::swap(_M_word, __rhs._M_word);
 255        else
 256          {
 257            ios_base* __local;
 258            ios_base* __allocated;
 259            if (__lhs_local)
 260              {
 261                __local = this;
 262                __allocated = &__rhs;
 263              }
 264            else
 265              {
 266                __local = &__rhs;
 267                __allocated= this;
 268              }
 269            for (int __i = 0; __i < _S_local_word_size; __i++)
 270              __allocated->_M_local_word[__i] = __local->_M_local_word[__i];
 271            __local->_M_word = __allocated->_M_word;
 272            __allocated->_M_word = __allocated->_M_local_word;
 273          }
 274        std::swap(_M_word_size, __rhs._M_word_size);
 275      }
 276     std::swap(_M_ios_locale, __rhs._M_ios_locale);
 277   }
 278
 279 _GLIBCXX_END_NAMESPACE_VERSION
 280 } // namespace