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

   1 // Iostreams base classes -*- C++ -*-
   2
   3 // Copyright (C) 1997-2019 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 #include <ios>
  30 #include <limits>
  31
  32 namespace std _GLIBCXX_VISIBILITY(default)
  33 {
  34 _GLIBCXX_BEGIN_NAMESPACE_VERSION
  35
  36   // Definitions for static const members of ios_base.
  37   const ios_base::fmtflags ios_base::boolalpha;
  38   const ios_base::fmtflags ios_base::dec;
  39   const ios_base::fmtflags ios_base::fixed;
  40   const ios_base::fmtflags ios_base::hex;
  41   const ios_base::fmtflags ios_base::internal;
  42   const ios_base::fmtflags ios_base::left;
  43   const ios_base::fmtflags ios_base::oct;
  44   const ios_base::fmtflags ios_base::right;
  45   const ios_base::fmtflags ios_base::scientific;
  46   const ios_base::fmtflags ios_base::showbase;
  47   const ios_base::fmtflags ios_base::showpoint;
  48   const ios_base::fmtflags ios_base::showpos;
  49   const ios_base::fmtflags ios_base::skipws;
  50   const ios_base::fmtflags ios_base::unitbuf;
  51   const ios_base::fmtflags ios_base::uppercase;
  52   const ios_base::fmtflags ios_base::adjustfield;
  53   const ios_base::fmtflags ios_base::basefield;
  54   const ios_base::fmtflags ios_base::floatfield;
  55
  56   const ios_base::iostate ios_base::badbit;
  57   const ios_base::iostate ios_base::eofbit;
  58   const ios_base::iostate ios_base::failbit;
  59   const ios_base::iostate ios_base::goodbit;
  60
  61   const ios_base::openmode ios_base::app;
  62   const ios_base::openmode ios_base::ate;
  63   const ios_base::openmode ios_base::binary;
  64   const ios_base::openmode ios_base::in;
  65   const ios_base::openmode ios_base::out;
  66   const ios_base::openmode ios_base::trunc;
  67
  68   const ios_base::seekdir ios_base::beg;
  69   const ios_base::seekdir ios_base::cur;
  70   const ios_base::seekdir ios_base::end;
  71
  72   _Atomic_word ios_base::Init::_S_refcount;
  73
  74   bool ios_base::Init::_S_synced_with_stdio = true;
  75
  76   ios_base::ios_base() throw()
  77   : _M_precision(), _M_width(), _M_flags(), _M_exception(),
  78   _M_streambuf_state(), _M_callbacks(0), _M_word_zero(),
  79   _M_word_size(_S_local_word_size), _M_word(_M_local_word), _M_ios_locale()
  80   {
  81     // Do nothing: basic_ios::init() does it.
  82     // NB: _M_callbacks and _M_word must be zero for non-initialized
  83     // ios_base to go through ~ios_base gracefully.
  84   }
  85
  86   // 27.4.2.7  ios_base constructors/destructors
  87   ios_base::~ios_base()
  88   {
  89     _M_call_callbacks(erase_event);
  90     _M_dispose_callbacks();
  91     if (_M_word != _M_local_word)
  92       {
  93         delete [] _M_word;
  94         _M_word = 0;
  95       }
  96   }
  97
  98   // 27.4.2.5  ios_base storage functions
  99   int
 100   ios_base::xalloc() throw()
 101   {
 102     // Implementation note: Initialize top to zero to ensure that
 103     // initialization occurs before main() is started.
 104     static _Atomic_word _S_top = 0;
 105     return __gnu_cxx::__exchange_and_add_dispatch(&_S_top, 1) + 4;
 106   }
 107
 108   void
 109   ios_base::register_callback(event_callback __fn, int __index)
 110   { _M_callbacks = new _Callback_list(__fn, __index, _M_callbacks); }
 111
 112   // 27.4.2.5 [ios.base.storage] iword/pword storage
 113   ios_base::_Words&
 114   ios_base::_M_grow_words(int __ix, bool __iword)
 115   {
 116     // Precondition: _M_word_size <= __ix
 117     int __newsize = _S_local_word_size;
 118     _Words* __words = _M_local_word;
 119     const char* __error = nullptr;
 120     if ((unsigned)__ix >= (unsigned)numeric_limits<int>::max())
 121       __error = __N("ios_base::_M_grow_words is not valid");
 122     else if (__ix > _S_local_word_size - 1)
 123       {
 124         __newsize = __ix + 1;
 125         /* We still need to catch bad_alloc even though we use
 126            a nothrow new, because the new-expression can throw
 127            a bad_array_new_length.  */
 128         __try
 129           { __words = new (std::nothrow) _Words[__newsize]; }
 130         __catch(const std::bad_alloc&)
 131           { __words = nullptr; }
 132         if (!__words)
 133           __error = __N("ios_base::_M_grow_words allocation failed");
 134         else
 135           {
 136             for (int __i = 0; __i < _M_word_size; __i++)
 137               __words[__i] = _M_word[__i];
 138             if (_M_word && _M_word != _M_local_word)
 139               {
 140                 delete [] _M_word;
 141                 _M_word = 0;
 142               }
 143           }
 144       }
 145     if (__error)
 146       {
 147         _M_streambuf_state |= badbit;
 148         if (_M_streambuf_state & _M_exception)
 149           __throw_ios_failure(__error);
 150         if (__iword)
 151           _M_word_zero._M_iword = 0;
 152         else
 153           _M_word_zero._M_pword = 0;
 154         return _M_word_zero;
 155       }
 156     _M_word = __words;
 157     _M_word_size = __newsize;
 158     return _M_word[__ix];
 159   }
 160
 161   void
 162   ios_base::_M_call_callbacks(event __e) throw()
 163   {
 164     _Callback_list* __p = _M_callbacks;
 165     while (__p)
 166       {
 167         __try
 168           { (*__p->_M_fn) (__e, *this, __p->_M_index); }
 169         __catch(...)
 170           { }
 171         __p = __p->_M_next;
 172       }
 173   }
 174
 175   void
 176   ios_base::_M_dispose_callbacks(void) throw()
 177   {
 178     _Callback_list* __p = _M_callbacks;
 179     while (__p && __p->_M_remove_reference() == 0)
 180       {
 181         _Callback_list* __next = __p->_M_next;
 182         delete __p;
 183         __p = __next;
 184       }
 185     _M_callbacks = 0;
 186   }
 187
 188   void
 189   ios_base::_M_move(ios_base& __rhs) noexcept
 190   {
 191     _M_precision = __rhs._M_precision;
 192     _M_width = __rhs._M_width;
 193     _M_flags = __rhs._M_flags;
 194     _M_exception = __rhs._M_exception;
 195     _M_streambuf_state = __rhs._M_streambuf_state;
 196     _M_callbacks = std::__exchange(__rhs._M_callbacks, nullptr);
 197     if (_M_word != _M_local_word)
 198        delete[] _M_word;
 199     if (__rhs._M_word == __rhs._M_local_word)
 200      {
 201        _M_word = _M_local_word;
 202        _M_word_size = _S_local_word_size;
 203        for (int __i = 0; __i < _S_local_word_size; __i++)
 204          _M_word[__i] = std::__exchange(__rhs._M_word[__i], {});
 205      }
 206     else
 207      {
 208        _M_word = std::__exchange(__rhs._M_word, __rhs._M_local_word);
 209        _M_word_size
 210          = std::__exchange(__rhs._M_word_size, _S_local_word_size);
 211      }
 212     _M_ios_locale = __rhs._M_ios_locale;
 213   }
 214
 215   void
 216   ios_base::_M_swap(ios_base& __rhs) noexcept
 217   {
 218     std::swap(_M_precision, __rhs._M_precision);
 219     std::swap(_M_width, __rhs._M_width);
 220     std::swap(_M_flags, __rhs._M_flags);
 221     std::swap(_M_exception, __rhs._M_exception);
 222     std::swap(_M_streambuf_state, __rhs._M_streambuf_state);
 223     std::swap(_M_callbacks, __rhs._M_callbacks);
 224     const bool __lhs_local = _M_word == _M_local_word;
 225     const bool __rhs_local = __rhs._M_word == __rhs._M_local_word;
 226     if (__lhs_local && __rhs_local)
 227      std::swap(_M_local_word, __rhs._M_local_word); // array swap
 228     else
 229      {
 230        if (!__lhs_local && !__rhs_local)
 231          std::swap(_M_word, __rhs._M_word);
 232        else
 233          {
 234            ios_base* __local;
 235            ios_base* __allocated;
 236            if (__lhs_local)
 237              {
 238                __local = this;
 239                __allocated = &__rhs;
 240              }
 241            else
 242              {
 243                __local = &__rhs;
 244                __allocated= this;
 245              }
 246            for (int __i = 0; __i < _S_local_word_size; __i++)
 247              __allocated->_M_local_word[__i] = __local->_M_local_word[__i];
 248            __local->_M_word = __allocated->_M_word;
 249            __allocated->_M_word = __allocated->_M_local_word;
 250          }
 251        std::swap(_M_word_size, __rhs._M_word_size);
 252      }
 253     std::swap(_M_ios_locale, __rhs._M_ios_locale);
 254   }
 255
 256 _GLIBCXX_END_NAMESPACE_VERSION
 257 } // namespace