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::Init::Init()
 153   {
 154     if (_S_ios_base_init == 0)
 155       {
 156         // Standard streams default to synced with "C" operations.
 157         _S_synced_with_stdio = true;
 158
 159         new (&buf_cout_sync) stdio_sync_filebuf<char>(stdout);
 160         new (&buf_cin_sync) stdio_sync_filebuf<char>(stdin);
 161         new (&buf_cerr_sync) stdio_sync_filebuf<char>(stderr);
 162
 163         // The standard streams are constructed once only and never
 164         // destroyed.
 165         new (&cout) ostream(&buf_cout_sync);
 166         new (&cin) istream(&buf_cin_sync);
 167         new (&cerr) ostream(&buf_cerr_sync);
 168         new (&clog) ostream(&buf_cerr_sync);
 169         cin.tie(&cout);
 170         cerr.flags(ios_base::unitbuf);
 171
 172 #ifdef _GLIBCXX_USE_WCHAR_T
 173         new (&buf_wcout_sync) stdio_sync_filebuf<wchar_t>(stdout);
 174         new (&buf_wcin_sync) stdio_sync_filebuf<wchar_t>(stdin);
 175         new (&buf_wcerr_sync) stdio_sync_filebuf<wchar_t>(stderr);
 176
 177         new (&wcout) wostream(&buf_wcout_sync);
 178         new (&wcin) wistream(&buf_wcin_sync);
 179         new (&wcerr) wostream(&buf_wcerr_sync);
 180         new (&wclog) wostream(&buf_wcerr_sync);
 181         wcin.tie(&wcout);
 182         wcerr.flags(ios_base::unitbuf);
 183 #endif
 184
 185         _S_ios_base_init = 1;
 186       }
 187     ++_S_ios_base_init;
 188   }
 189
 190   ios_base::Init::~Init()
 191   {
 192     if (--_S_ios_base_init == 1)
 193       {
 194         // Catch any exceptions thrown by basic_ostream::flush()
 195         try
 196           {
 197             // Flush standard output streams as required by 27.4.2.1.6
 198             cout.flush();
 199             cerr.flush();
 200             clog.flush();
 201
 202 #ifdef _GLIBCXX_USE_WCHAR_T
 203             wcout.flush();
 204             wcerr.flush();
 205             wclog.flush();
 206 #endif
 207           }
 208         catch (...)
 209           { }
 210       }
 211   }
 212
 213   // 27.4.2.5  ios_base storage functions
 214   int
 215   ios_base::xalloc() throw()
 216   {
 217     // Implementation note: Initialize top to zero to ensure that
 218     // initialization occurs before main() is started.
 219     static _Atomic_word _S_top = 0;
 220     return __exchange_and_add(&_S_top, 1) + 4;
 221   }
 222
 223   // 27.4.2.5  iword/pword storage
 224   ios_base::_Words&
 225   ios_base::_M_grow_words(int ix)
 226   {
 227     // Precondition: _M_word_size <= ix
 228     int newsize = _S_local_word_size;
 229     _Words* words = _M_local_word;
 230     if (ix > _S_local_word_size - 1)
 231       {
 232         if (ix < numeric_limits<int>::max())
 233           {
 234             newsize = ix + 1;
 235             try
 236               { words = new _Words[newsize]; }
 237             catch (...)
 238               {
 239                 _M_streambuf_state |= badbit;
 240                 if (_M_streambuf_state & _M_exception)
 241                   __throw_ios_failure("ios_base::_M_grow_words "
 242                                       "allocation failed");
 243                 return _M_word_zero;
 244               }
 245             for (int i = 0; i < _M_word_size; i++)
 246               words[i] = _M_word[i];
 247             if (_M_word && _M_word != _M_local_word)
 248               {
 249                 delete [] _M_word;
 250                 _M_word = 0;
 251               }
 252           }
 253         else
 254           {
 255             _M_streambuf_state |= badbit;
 256             if (_M_streambuf_state & _M_exception)
 257               __throw_ios_failure("ios_base::_M_grow_words is not valid");
 258             return _M_word_zero;
 259           }
 260       }
 261     _M_word = words;
 262     _M_word_size = newsize;
 263     return _M_word[ix];
 264   }
 265
 266   // Called only by basic_ios<>::init.
 267   void
 268   ios_base::_M_init()
 269   {
 270     // NB: May be called more than once
 271     _M_precision = 6;
 272     _M_width = 0;
 273     _M_flags = skipws | dec;
 274     _M_ios_locale = locale();
 275   }
 276
 277   // 27.4.2.3  ios_base locale functions
 278   locale
 279   ios_base::imbue(const locale& __loc)
 280   {
 281     locale __old = _M_ios_locale;
 282     _M_ios_locale = __loc;
 283     _M_call_callbacks(imbue_event);
 284     return __old;
 285   }
 286
 287   ios_base::ios_base()
 288   : _M_callbacks(0), _M_word_size(_S_local_word_size), _M_word(_M_local_word)
 289   {
 290     // Do nothing: basic_ios::init() does it.
 291     // NB: _M_callbacks and _M_word must be zero for non-initialized
 292     // ios_base to go through ~ios_base gracefully.
 293   }
 294
 295   // 27.4.2.7  ios_base constructors/destructors
 296   ios_base::~ios_base()
 297   {
 298     _M_call_callbacks(erase_event);
 299     _M_dispose_callbacks();
 300     if (_M_word != _M_local_word)
 301       {
 302         delete [] _M_word;
 303         _M_word = 0;
 304       }
 305   }
 306
 307   void
 308   ios_base::register_callback(event_callback __fn, int __index)
 309   { _M_callbacks = new _Callback_list(__fn, __index, _M_callbacks); }
 310
 311   void
 312   ios_base::_M_call_callbacks(event __e) throw()
 313   {
 314     _Callback_list* __p = _M_callbacks;
 315     while (__p)
 316       {
 317         try
 318           { (*__p->_M_fn) (__e, *this, __p->_M_index); }
 319         catch (...)
 320           { }
 321         __p = __p->_M_next;
 322       }
 323   }
 324
 325   void
 326   ios_base::_M_dispose_callbacks(void)
 327   {
 328     _Callback_list* __p = _M_callbacks;
 329     while (__p && __p->_M_remove_reference() == 0)
 330       {
 331         _Callback_list* __next = __p->_M_next;
 332         delete __p;
 333         __p = __next;
 334       }
 335     _M_callbacks = 0;
 336   }
 337
 338   bool
 339   ios_base::sync_with_stdio(bool __sync)
 340   {
 341 #ifdef _GLIBCXX_RESOLVE_LIB_DEFECTS
 342     // 49.  Underspecification of ios_base::sync_with_stdio
 343     bool __ret = ios_base::Init::_S_synced_with_stdio;
 344 #endif
 345
 346     // Turn off sync with C FILE* for cin, cout, cerr, clog iff
 347     // currently synchronized.
 348     if (!__sync && __ret)
 349       {
 350         ios_base::Init::_S_synced_with_stdio = __sync;
 351
 352         // Explicitly call dtors to free any memory that is
 353         // dynamically allocated by filebuf ctor or member functions,
 354         // but don't deallocate all memory by calling operator delete.
 355         buf_cout_sync.~stdio_sync_filebuf<char>();
 356         buf_cin_sync.~stdio_sync_filebuf<char>();
 357         buf_cerr_sync.~stdio_sync_filebuf<char>();
 358
 359 #ifdef _GLIBCXX_USE_WCHAR_T
 360         buf_wcout_sync.~stdio_sync_filebuf<wchar_t>();
 361         buf_wcin_sync.~stdio_sync_filebuf<wchar_t>();
 362         buf_wcerr_sync.~stdio_sync_filebuf<wchar_t>();
 363 #endif
 364
 365         // Create stream buffers for the standard streams and use
 366         // those buffers without destroying and recreating the
 367         // streams.
 368         new (&buf_cout) stdio_filebuf<char>(stdout, ios_base::out);
 369         new (&buf_cin) stdio_filebuf<char>(stdin, ios_base::in);
 370         new (&buf_cerr) stdio_filebuf<char>(stderr, ios_base::out);
 371         cout.rdbuf(&buf_cout);
 372         cin.rdbuf(&buf_cin);
 373         cerr.rdbuf(&buf_cerr);
 374         clog.rdbuf(&buf_cerr);
 375
 376 #ifdef _GLIBCXX_USE_WCHAR_T
 377         new (&buf_wcout) stdio_filebuf<wchar_t>(stdout, ios_base::out);
 378         new (&buf_wcin) stdio_filebuf<wchar_t>(stdin, ios_base::in);
 379         new (&buf_wcerr) stdio_filebuf<wchar_t>(stderr, ios_base::out);
 380         wcout.rdbuf(&buf_wcout);
 381         wcin.rdbuf(&buf_wcin);
 382         wcerr.rdbuf(&buf_wcerr);
 383         wclog.rdbuf(&buf_wcerr);
 384 #endif
 385       }
 386     return __ret;
 387   }
 388 } // namespace std