libstdc++-v3/src/ios.cc

   1 // Iostreams base classes -*- C++ -*-
   2
   3 // Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003
   4 // Free Software Foundation, Inc.
   5 //
   6 // This file is part of the GNU ISO C++ Library.  This library is free
   7 // software; you can redistribute it and/or modify it under the
   8 // terms of the GNU General Public License as published by the
   9 // Free Software Foundation; either version 2, or (at your option)
  10 // any later version.
  11
  12 // This library is distributed in the hope that it will be useful,
  13 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 // GNU General Public License for more details.
  16
  17 // You should have received a copy of the GNU General Public License along
  18 // with this library; see the file COPYING.  If not, write to the Free
  19 // Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
  20 // USA.
  21
  22 // As a special exception, you may use this file as part of a free software
  23 // library without restriction.  Specifically, if other files instantiate
  24 // templates or use macros or inline functions from this file, or you compile
  25 // this file and link it with other files to produce an executable, this
  26 // file does not by itself cause the resulting executable to be covered by
  27 // the GNU General Public License.  This exception does not however
  28 // invalidate any other reasons why the executable file might be covered by
  29 // the GNU General Public License.
  30
  31 //
  32 // ISO C++ 14882: 27.4  Iostreams base classes
  33 //
  34
  35 #include <ios>
  36 #include <ostream>
  37 #include <istream>
  38 #include <fstream>
  39 #include <bits/atomicity.h>
  40 #include <ext/stdio_filebuf.h>
  41 #include <ext/stdio_sync_filebuf.h>
  42
  43 namespace __gnu_cxx
  44 {
  45   // Extern declarations for global objects in src/globals.cc.
  46   extern stdio_sync_filebuf<char> buf_cout_sync;
  47   extern stdio_sync_filebuf<char> buf_cin_sync;
  48   extern stdio_sync_filebuf<char> buf_cerr_sync;
  49
  50   extern stdio_filebuf<char> buf_cout;
  51   extern stdio_filebuf<char> buf_cin;
  52   extern stdio_filebuf<char> buf_cerr;
  53
  54 #ifdef _GLIBCXX_USE_WCHAR_T
  55   extern stdio_sync_filebuf<wchar_t> buf_wcout_sync;
  56   extern stdio_sync_filebuf<wchar_t> buf_wcin_sync;
  57   extern stdio_sync_filebuf<wchar_t> buf_wcerr_sync;
  58
  59   extern stdio_filebuf<wchar_t> buf_wcout;
  60   extern stdio_filebuf<wchar_t> buf_wcin;
  61   extern stdio_filebuf<wchar_t> buf_wcerr;
  62 #endif
  63 } // namespace __gnu_cxx
  64
  65 namespace std
  66 {
  67   using namespace __gnu_cxx;
  68
  69   extern istream cin;
  70   extern ostream cout;
  71   extern ostream cerr;
  72   extern ostream clog;
  73
  74 #ifdef _GLIBCXX_USE_WCHAR_T
  75   extern wistream wcin;
  76   extern wostream wcout;
  77   extern wostream wcerr;
  78   extern wostream wclog;
  79 #endif
  80
  81   // Definitions for static const data members of __ios_flags.
  82   const __ios_flags::__int_type __ios_flags::_S_boolalpha;
  83   const __ios_flags::__int_type __ios_flags::_S_dec;
  84   const __ios_flags::__int_type __ios_flags::_S_fixed;
  85   const __ios_flags::__int_type __ios_flags::_S_hex;
  86   const __ios_flags::__int_type __ios_flags::_S_internal;
  87   const __ios_flags::__int_type __ios_flags::_S_left;
  88   const __ios_flags::__int_type __ios_flags::_S_oct;
  89   const __ios_flags::__int_type __ios_flags::_S_right;
  90   const __ios_flags::__int_type __ios_flags::_S_scientific;
  91   const __ios_flags::__int_type __ios_flags::_S_showbase;
  92   const __ios_flags::__int_type __ios_flags::_S_showpoint;
  93   const __ios_flags::__int_type __ios_flags::_S_showpos;
  94   const __ios_flags::__int_type __ios_flags::_S_skipws;
  95   const __ios_flags::__int_type __ios_flags::_S_unitbuf;
  96   const __ios_flags::__int_type __ios_flags::_S_uppercase;
  97   const __ios_flags::__int_type __ios_flags::_S_adjustfield;
  98   const __ios_flags::__int_type __ios_flags::_S_basefield;
  99   const __ios_flags::__int_type __ios_flags::_S_floatfield;
 100
 101   const __ios_flags::__int_type __ios_flags::_S_badbit;
 102   const __ios_flags::__int_type __ios_flags::_S_eofbit;
 103   const __ios_flags::__int_type __ios_flags::_S_failbit;
 104
 105   const __ios_flags::__int_type __ios_flags::_S_app;
 106   const __ios_flags::__int_type __ios_flags::_S_ate;
 107   const __ios_flags::__int_type __ios_flags::_S_bin;
 108   const __ios_flags::__int_type __ios_flags::_S_in;
 109   const __ios_flags::__int_type __ios_flags::_S_out;
 110   const __ios_flags::__int_type __ios_flags::_S_trunc;
 111
 112   // Definitions for static const members of ios_base.
 113   const ios_base::fmtflags ios_base::boolalpha;
 114   const ios_base::fmtflags ios_base::dec;
 115   const ios_base::fmtflags ios_base::fixed;
 116   const ios_base::fmtflags ios_base::hex;
 117   const ios_base::fmtflags ios_base::internal;
 118   const ios_base::fmtflags ios_base::left;
 119   const ios_base::fmtflags ios_base::oct;
 120   const ios_base::fmtflags ios_base::right;
 121   const ios_base::fmtflags ios_base::scientific;
 122   const ios_base::fmtflags ios_base::showbase;
 123   const ios_base::fmtflags ios_base::showpoint;
 124   const ios_base::fmtflags ios_base::showpos;
 125   const ios_base::fmtflags ios_base::skipws;
 126   const ios_base::fmtflags ios_base::unitbuf;
 127   const ios_base::fmtflags ios_base::uppercase;
 128   const ios_base::fmtflags ios_base::adjustfield;
 129   const ios_base::fmtflags ios_base::basefield;
 130   const ios_base::fmtflags ios_base::floatfield;
 131
 132   const ios_base::iostate ios_base::badbit;
 133   const ios_base::iostate ios_base::eofbit;
 134   const ios_base::iostate ios_base::failbit;
 135   const ios_base::iostate ios_base::goodbit;
 136
 137   const ios_base::openmode ios_base::app;
 138   const ios_base::openmode ios_base::ate;
 139   const ios_base::openmode ios_base::binary;
 140   const ios_base::openmode ios_base::in;
 141   const ios_base::openmode ios_base::out;
 142   const ios_base::openmode ios_base::trunc;
 143
 144   const ios_base::seekdir ios_base::beg;
 145   const ios_base::seekdir ios_base::cur;
 146   const ios_base::seekdir ios_base::end;
 147
 148   const int ios_base::_S_local_word_size;
 149   int ios_base::Init::_S_ios_base_init = 0;
 150   bool ios_base::Init::_S_synced_with_stdio = true;
 151
 152   ios_base::failure::failure(const string& __str) throw()
 153   {
 154     strncpy(_M_name, __str.c_str(), _S_bufsize);
 155     _M_name[_S_bufsize - 1] = '\0';
 156   }
 157
 158   ios_base::failure::~failure() throw()
 159   { }
 160
 161   const char*
 162   ios_base::failure::what() const throw()
 163   { return _M_name; }
 164
 165   ios_base::Init::Init()
 166   {
 167     if (_S_ios_base_init == 0)
 168       {
 169         // Standard streams default to synced with "C" operations.
 170         ios_base::Init::_S_synced_with_stdio = true;
 171
 172         new (&buf_cout_sync) stdio_sync_filebuf<char>(stdout);
 173         new (&buf_cin_sync) stdio_sync_filebuf<char>(stdin);
 174         new (&buf_cerr_sync) stdio_sync_filebuf<char>(stderr);
 175
 176         // The standard streams are constructed once only and never
 177         // destroyed.
 178         new (&cout) ostream(&buf_cout_sync);
 179         new (&cin) istream(&buf_cin_sync);
 180         new (&cerr) ostream(&buf_cerr_sync);
 181         new (&clog) ostream(&buf_cerr_sync);
 182         cin.tie(&cout);
 183         cerr.flags(ios_base::unitbuf);
 184
 185 #ifdef _GLIBCXX_USE_WCHAR_T
 186         new (&buf_wcout_sync) stdio_sync_filebuf<wchar_t>(stdout);
 187         new (&buf_wcin_sync) stdio_sync_filebuf<wchar_t>(stdin);
 188         new (&buf_wcerr_sync) stdio_sync_filebuf<wchar_t>(stderr);
 189
 190         new (&wcout) wostream(&buf_wcout_sync);
 191         new (&wcin) wistream(&buf_wcin_sync);
 192         new (&wcerr) wostream(&buf_wcerr_sync);
 193         new (&wclog) wostream(&buf_wcerr_sync);
 194         wcin.tie(&wcout);
 195         wcerr.flags(ios_base::unitbuf);
 196 #endif
 197
 198         _S_ios_base_init = 1;
 199       }
 200     ++_S_ios_base_init;
 201   }
 202
 203   ios_base::Init::~Init()
 204   {
 205     if (--_S_ios_base_init == 1)
 206       {
 207         // Catch any exceptions thrown by basic_ostream::flush()
 208         try
 209           {
 210             // Flush standard output streams as required by 27.4.2.1.6
 211             cout.flush();
 212             cerr.flush();
 213             clog.flush();
 214
 215 #ifdef _GLIBCXX_USE_WCHAR_T
 216             wcout.flush();
 217             wcerr.flush();
 218             wclog.flush();
 219 #endif
 220           }
 221         catch (...)
 222           { }
 223       }
 224   }
 225
 226   // 27.4.2.5  ios_base storage functions
 227   int
 228   ios_base::xalloc() throw()
 229   {
 230     // Implementation note: Initialize top to zero to ensure that
 231     // initialization occurs before main() is started.
 232     static _Atomic_word _S_top = 0;
 233     return __exchange_and_add(&_S_top, 1) + 4;
 234   }
 235
 236   // 27.4.2.5  iword/pword storage
 237   ios_base::_Words&
 238   ios_base::_M_grow_words(int ix)
 239   {
 240     // Precondition: _M_word_size <= ix
 241     int newsize = _S_local_word_size;
 242     _Words* words = _M_local_word;
 243     if (ix > _S_local_word_size - 1)
 244       {
 245         if (ix < numeric_limits<int>::max())
 246           {
 247             newsize = ix + 1;
 248             try
 249               { words = new _Words[newsize]; }
 250             catch (...)
 251               {
 252                 _M_streambuf_state |= badbit;
 253                 if (_M_streambuf_state & _M_exception)
 254                   __throw_ios_failure("ios_base::_M_grow_words "
 255                                       "allocation failed");
 256                 return _M_word_zero;
 257               }
 258             for (int i = 0; i < _M_word_size; i++)
 259               words[i] = _M_word[i];
 260             if (_M_word && _M_word != _M_local_word)
 261               {
 262                 delete [] _M_word;
 263                 _M_word = 0;
 264               }
 265           }
 266         else
 267           {
 268             _M_streambuf_state |= badbit;
 269             if (_M_streambuf_state & _M_exception)
 270               __throw_ios_failure("ios_base::_M_grow_words is not valid");
 271             return _M_word_zero;
 272           }
 273       }
 274     _M_word = words;
 275     _M_word_size = newsize;
 276     return _M_word[ix];
 277   }
 278
 279   // Called only by basic_ios<>::init.
 280   void
 281   ios_base::_M_init()
 282   {
 283     // NB: May be called more than once
 284     _M_precision = 6;
 285     _M_width = 0;
 286     _M_flags = skipws | dec;
 287     _M_ios_locale = locale();
 288   }
 289
 290   // 27.4.2.3  ios_base locale functions
 291   locale
 292   ios_base::imbue(const locale& __loc)
 293   {
 294     locale __old = _M_ios_locale;
 295     _M_ios_locale = __loc;
 296     _M_call_callbacks(imbue_event);
 297     return __old;
 298   }
 299
 300   ios_base::ios_base()
 301   : _M_callbacks(0), _M_word_size(_S_local_word_size), _M_word(_M_local_word)
 302   {
 303     // Do nothing: basic_ios::init() does it.
 304     // NB: _M_callbacks and _M_word must be zero for non-initialized
 305     // ios_base to go through ~ios_base gracefully.
 306   }
 307
 308   // 27.4.2.7  ios_base constructors/destructors
 309   ios_base::~ios_base()
 310   {
 311     _M_call_callbacks(erase_event);
 312     _M_dispose_callbacks();
 313     if (_M_word != _M_local_word)
 314       {
 315         delete [] _M_word;
 316         _M_word = 0;
 317       }
 318   }
 319
 320   void
 321   ios_base::register_callback(event_callback __fn, int __index)
 322   { _M_callbacks = new _Callback_list(__fn, __index, _M_callbacks); }
 323
 324   void
 325   ios_base::_M_call_callbacks(event __e) throw()
 326   {
 327     _Callback_list* __p = _M_callbacks;
 328     while (__p)
 329       {
 330         try
 331           { (*__p->_M_fn) (__e, *this, __p->_M_index); }
 332         catch (...)
 333           { }
 334         __p = __p->_M_next;
 335       }
 336   }
 337
 338   void
 339   ios_base::_M_dispose_callbacks(void)
 340   {
 341     _Callback_list* __p = _M_callbacks;
 342     while (__p && __p->_M_remove_reference() == 0)
 343       {
 344         _Callback_list* __next = __p->_M_next;
 345         delete __p;
 346         __p = __next;
 347       }
 348     _M_callbacks = 0;
 349   }
 350
 351   bool
 352   ios_base::sync_with_stdio(bool __sync)
 353   {
 354 #ifdef _GLIBCXX_RESOLVE_LIB_DEFECTS
 355     // 49.  Underspecification of ios_base::sync_with_stdio
 356     bool __ret = ios_base::Init::_S_synced_with_stdio;
 357 #endif
 358
 359     // Turn off sync with C FILE* for cin, cout, cerr, clog iff
 360     // currently synchronized.
 361     if (!__sync && __ret)
 362       {
 363         ios_base::Init::_S_synced_with_stdio = __sync;
 364
 365         // Explicitly call dtors to free any memory that is
 366         // dynamically allocated by filebuf ctor or member functions,
 367         // but don't deallocate all memory by calling operator delete.
 368         buf_cout_sync.~stdio_sync_filebuf<char>();
 369         buf_cin_sync.~stdio_sync_filebuf<char>();
 370         buf_cerr_sync.~stdio_sync_filebuf<char>();
 371
 372 #ifdef _GLIBCXX_USE_WCHAR_T
 373         buf_wcout_sync.~stdio_sync_filebuf<wchar_t>();
 374         buf_wcin_sync.~stdio_sync_filebuf<wchar_t>();
 375         buf_wcerr_sync.~stdio_sync_filebuf<wchar_t>();
 376 #endif
 377
 378         // Create stream buffers for the standard streams and use
 379         // those buffers without destroying and recreating the
 380         // streams.
 381         new (&buf_cout) stdio_filebuf<char>(stdout, ios_base::out);
 382         new (&buf_cin) stdio_filebuf<char>(stdin, ios_base::in);
 383         new (&buf_cerr) stdio_filebuf<char>(stderr, ios_base::out);
 384         cout.rdbuf(&buf_cout);
 385         cin.rdbuf(&buf_cin);
 386         cerr.rdbuf(&buf_cerr);
 387         clog.rdbuf(&buf_cerr);
 388
 389 #ifdef _GLIBCXX_USE_WCHAR_T
 390         new (&buf_wcout) stdio_filebuf<wchar_t>(stdout, ios_base::out);
 391         new (&buf_wcin) stdio_filebuf<wchar_t>(stdin, ios_base::in);
 392         new (&buf_wcerr) stdio_filebuf<wchar_t>(stderr, ios_base::out);
 393         wcout.rdbuf(&buf_wcout);
 394         wcin.rdbuf(&buf_wcin);
 395         wcerr.rdbuf(&buf_wcerr);
 396         wclog.rdbuf(&buf_wcerr);
 397 #endif
 398       }
 399     return __ret;
 400   }
 401 }  // namespace std