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
  42 namespace __gnu_cxx
  43 {
  44   // Extern declarations for global objects in src/globals.cc.
  45   extern stdio_filebuf<char> buf_cout;
  46   extern stdio_filebuf<char> buf_cin;
  47   extern stdio_filebuf<char> buf_cerr;
  48
  49 #ifdef _GLIBCPP_USE_WCHAR_T
  50   extern stdio_filebuf<wchar_t> buf_wcout;
  51   extern stdio_filebuf<wchar_t> buf_wcin;
  52   extern stdio_filebuf<wchar_t> buf_wcerr;
  53 #endif
  54 } // namespace __gnu_cxx
  55
  56 namespace std
  57 {
  58   using namespace __gnu_cxx;
  59
  60   extern istream cin;
  61   extern ostream cout;
  62   extern ostream cerr;
  63   extern ostream clog;
  64
  65 #ifdef _GLIBCPP_USE_WCHAR_T
  66   extern wistream wcin;
  67   extern wostream wcout;
  68   extern wostream wcerr;
  69   extern wostream wclog;
  70 #endif
  71
  72   // Definitions for static const data members of __ios_flags.
  73   const __ios_flags::__int_type __ios_flags::_S_boolalpha;
  74   const __ios_flags::__int_type __ios_flags::_S_dec;
  75   const __ios_flags::__int_type __ios_flags::_S_fixed;
  76   const __ios_flags::__int_type __ios_flags::_S_hex;
  77   const __ios_flags::__int_type __ios_flags::_S_internal;
  78   const __ios_flags::__int_type __ios_flags::_S_left;
  79   const __ios_flags::__int_type __ios_flags::_S_oct;
  80   const __ios_flags::__int_type __ios_flags::_S_right;
  81   const __ios_flags::__int_type __ios_flags::_S_scientific;
  82   const __ios_flags::__int_type __ios_flags::_S_showbase;
  83   const __ios_flags::__int_type __ios_flags::_S_showpoint;
  84   const __ios_flags::__int_type __ios_flags::_S_showpos;
  85   const __ios_flags::__int_type __ios_flags::_S_skipws;
  86   const __ios_flags::__int_type __ios_flags::_S_unitbuf;
  87   const __ios_flags::__int_type __ios_flags::_S_uppercase;
  88   const __ios_flags::__int_type __ios_flags::_S_adjustfield;
  89   const __ios_flags::__int_type __ios_flags::_S_basefield;
  90   const __ios_flags::__int_type __ios_flags::_S_floatfield;
  91
  92   const __ios_flags::__int_type __ios_flags::_S_badbit;
  93   const __ios_flags::__int_type __ios_flags::_S_eofbit;
  94   const __ios_flags::__int_type __ios_flags::_S_failbit;
  95
  96   const __ios_flags::__int_type __ios_flags::_S_app;
  97   const __ios_flags::__int_type __ios_flags::_S_ate;
  98   const __ios_flags::__int_type __ios_flags::_S_bin;
  99   const __ios_flags::__int_type __ios_flags::_S_in;
 100   const __ios_flags::__int_type __ios_flags::_S_out;
 101   const __ios_flags::__int_type __ios_flags::_S_trunc;
 102
 103   // Definitions for static const members of ios_base.
 104   const ios_base::fmtflags ios_base::boolalpha;
 105   const ios_base::fmtflags ios_base::dec;
 106   const ios_base::fmtflags ios_base::fixed;
 107   const ios_base::fmtflags ios_base::hex;
 108   const ios_base::fmtflags ios_base::internal;
 109   const ios_base::fmtflags ios_base::left;
 110   const ios_base::fmtflags ios_base::oct;
 111   const ios_base::fmtflags ios_base::right;
 112   const ios_base::fmtflags ios_base::scientific;
 113   const ios_base::fmtflags ios_base::showbase;
 114   const ios_base::fmtflags ios_base::showpoint;
 115   const ios_base::fmtflags ios_base::showpos;
 116   const ios_base::fmtflags ios_base::skipws;
 117   const ios_base::fmtflags ios_base::unitbuf;
 118   const ios_base::fmtflags ios_base::uppercase;
 119   const ios_base::fmtflags ios_base::adjustfield;
 120   const ios_base::fmtflags ios_base::basefield;
 121   const ios_base::fmtflags ios_base::floatfield;
 122
 123   const ios_base::iostate ios_base::badbit;
 124   const ios_base::iostate ios_base::eofbit;
 125   const ios_base::iostate ios_base::failbit;
 126   const ios_base::iostate ios_base::goodbit;
 127
 128   const ios_base::openmode ios_base::app;
 129   const ios_base::openmode ios_base::ate;
 130   const ios_base::openmode ios_base::binary;
 131   const ios_base::openmode ios_base::in;
 132   const ios_base::openmode ios_base::out;
 133   const ios_base::openmode ios_base::trunc;
 134
 135   const ios_base::seekdir ios_base::beg;
 136   const ios_base::seekdir ios_base::cur;
 137   const ios_base::seekdir ios_base::end;
 138
 139   const int ios_base::_S_local_word_size;
 140   int ios_base::Init::_S_ios_base_init = 0;
 141   bool ios_base::Init::_S_synced_with_stdio = true;
 142
 143   ios_base::failure::failure(const string& __str) throw()
 144   {
 145     strncpy(_M_name, __str.c_str(), _S_bufsize);
 146     _M_name[_S_bufsize - 1] = '\0';
 147   }
 148
 149   ios_base::failure::~failure() throw()
 150   { }
 151
 152   const char*
 153   ios_base::failure::what() const throw()
 154   { return _M_name; }
 155
 156   void
 157   ios_base::Init::_S_create_buffers(bool __sync)
 158   {
 159     size_t __out_size = __sync ? 0 : static_cast<size_t>(BUFSIZ);
 160     size_t __in_size = __sync ? 1 : static_cast<size_t>(BUFSIZ);
 161
 162     // Create stream buffers for the standard streams and use those
 163     // buffers without destroying and recreating the streams.
 164     new (&buf_cout) stdio_filebuf<char>(stdout, ios_base::out, __out_size);
 165     new (&buf_cin) stdio_filebuf<char>(stdin, ios_base::in, __in_size);
 166     new (&buf_cerr) stdio_filebuf<char>(stderr, ios_base::out, __out_size);
 167     cout.rdbuf(&buf_cout);
 168     cin.rdbuf(&buf_cin);
 169     cerr.rdbuf(&buf_cerr);
 170     clog.rdbuf(&buf_cerr);
 171
 172 #ifdef _GLIBCPP_USE_WCHAR_T
 173     new (&buf_wcout) stdio_filebuf<wchar_t>(stdout, ios_base::out, __out_size);
 174     new (&buf_wcin) stdio_filebuf<wchar_t>(stdin, ios_base::in, __in_size);
 175     new (&buf_wcerr) stdio_filebuf<wchar_t>(stderr, ios_base::out, __out_size);
 176     wcout.rdbuf(&buf_wcout);
 177     wcin.rdbuf(&buf_wcin);
 178     wcerr.rdbuf(&buf_wcerr);
 179     wclog.rdbuf(&buf_wcerr);
 180 #endif
 181   }
 182
 183   void
 184   ios_base::Init::_S_destroy_buffers()
 185   {
 186     // Explicitly call dtors to free any memory that is dynamically
 187     // allocated by filebuf ctor or member functions, but don't
 188     // deallocate all memory by calling operator delete.
 189     buf_cout.~stdio_filebuf();
 190     buf_cin.~stdio_filebuf();
 191     buf_cerr.~stdio_filebuf();
 192
 193 #ifdef _GLIBCPP_USE_WCHAR_T
 194     buf_wcout.~stdio_filebuf();
 195     buf_wcin.~stdio_filebuf();
 196     buf_wcerr.~stdio_filebuf();
 197 #endif
 198   }
 199
 200   ios_base::Init::Init()
 201   {
 202     if (_S_ios_base_init == 0)
 203       {
 204         // Standard streams default to synced with "C" operations.
 205         ios_base::Init::_S_synced_with_stdio = true;
 206
 207         // The standard streams are constructed once only and never destroyed.
 208         // The stream buffers are set in _S_create_buffers below.
 209         new (&cout) ostream(NULL);
 210         new (&cin) istream(NULL);
 211         new (&cerr) ostream(NULL);
 212         new (&clog) ostream(NULL);
 213         cin.tie(&cout);
 214         cerr.flags(ios_base::unitbuf);
 215
 216 #ifdef _GLIBCPP_USE_WCHAR_T
 217         new (&wcout) wostream(NULL);
 218         new (&wcin) wistream(NULL);
 219         new (&wcerr) wostream(NULL);
 220         new (&wclog) wostream(NULL);
 221         wcin.tie(&wcout);
 222         wcerr.flags(ios_base::unitbuf);
 223 #endif
 224
 225         _S_create_buffers(ios_base::Init::_S_synced_with_stdio);
 226         _S_ios_base_init = 1;
 227       }
 228     ++_S_ios_base_init;
 229   }
 230
 231   ios_base::Init::~Init()
 232   {
 233     if (--_S_ios_base_init == 1)
 234       {
 235         // Catch any exceptions thrown by basic_ostream::flush()
 236         try
 237           {
 238             // Flush standard output streams as required by 27.4.2.1.6
 239             cout.flush();
 240             cerr.flush();
 241             clog.flush();
 242
 243 #ifdef _GLIBCPP_USE_WCHAR_T
 244             wcout.flush();
 245             wcerr.flush();
 246             wclog.flush();
 247 #endif
 248           }
 249         catch (...)
 250           { }
 251       }
 252   }
 253
 254   // 27.4.2.5  ios_base storage functions
 255   int
 256   ios_base::xalloc() throw()
 257   {
 258     // Implementation note: Initialize top to zero to ensure that
 259     // initialization occurs before main() is started.
 260     static _Atomic_word _S_top = 0;
 261     return __exchange_and_add(&_S_top, 1) + 4;
 262   }
 263
 264   // 27.4.2.5  iword/pword storage
 265   ios_base::_Words&
 266   ios_base::_M_grow_words(int ix)
 267   {
 268     // Precondition: _M_word_size <= ix
 269     int newsize = _S_local_word_size;
 270     _Words* words = _M_local_word;
 271     if (ix > _S_local_word_size - 1)
 272       {
 273         if (ix < numeric_limits<int>::max())
 274           {
 275             newsize = ix + 1;
 276             try
 277               { words = new _Words[newsize]; }
 278             catch (...)
 279               {
 280                 _M_streambuf_state |= badbit;
 281                 if (_M_streambuf_state & _M_exception)
 282                   __throw_ios_failure("ios_base::_M_grow_words "
 283                                       "allocation failed");
 284                 return _M_word_zero;
 285               }
 286             for (int i = 0; i < _M_word_size; i++)
 287               words[i] = _M_word[i];
 288             if (_M_word && _M_word != _M_local_word)
 289               {
 290                 delete [] _M_word;
 291                 _M_word = 0;
 292               }
 293           }
 294         else
 295           {
 296             _M_streambuf_state |= badbit;
 297             if (_M_streambuf_state & _M_exception)
 298               __throw_ios_failure("ios_base::_M_grow_words ix not valid");
 299             return _M_word_zero;
 300           }
 301       }
 302     _M_word = words;
 303     _M_word_size = newsize;
 304     return _M_word[ix];
 305   }
 306
 307   // Called only by basic_ios<>::init.
 308   void
 309   ios_base::_M_init()
 310   {
 311     // NB: May be called more than once
 312     _M_precision = 6;
 313     _M_width = 0;
 314     _M_flags = skipws | dec;
 315     _M_ios_locale = locale();
 316   }
 317
 318   // 27.4.2.3  ios_base locale functions
 319   locale
 320   ios_base::imbue(const locale& __loc)
 321   {
 322     locale __old = _M_ios_locale;
 323     _M_ios_locale = __loc;
 324     _M_call_callbacks(imbue_event);
 325     return __old;
 326   }
 327
 328   ios_base::ios_base() : _M_callbacks(0), _M_word_size(_S_local_word_size),
 329                          _M_word(_M_local_word), _M_locale_cache(0)
 330   {
 331     // Do nothing: basic_ios::init() does it.
 332     // NB: _M_callbacks and _M_word must be zero for non-initialized
 333     // ios_base to go through ~ios_base gracefully.
 334   }
 335
 336   // 27.4.2.7  ios_base constructors/destructors
 337   ios_base::~ios_base()
 338   {
 339     _M_call_callbacks(erase_event);
 340     _M_dispose_callbacks();
 341     if (_M_word != _M_local_word)
 342       {
 343         delete [] _M_word;
 344         _M_word = 0;
 345       }
 346   }
 347
 348   void
 349   ios_base::register_callback(event_callback __fn, int __index)
 350   { _M_callbacks = new _Callback_list(__fn, __index, _M_callbacks); }
 351
 352   void
 353   ios_base::_M_call_callbacks(event __e) throw()
 354   {
 355     _Callback_list* __p = _M_callbacks;
 356     while (__p)
 357       {
 358         try
 359           { (*__p->_M_fn) (__e, *this, __p->_M_index); }
 360         catch (...)
 361           { }
 362         __p = __p->_M_next;
 363       }
 364   }
 365
 366   void
 367   ios_base::_M_dispose_callbacks(void)
 368   {
 369     _Callback_list* __p = _M_callbacks;
 370     while (__p && __p->_M_remove_reference() == 0)
 371       {
 372         _Callback_list* __next = __p->_M_next;
 373         delete __p;
 374         __p = __next;
 375       }
 376     _M_callbacks = 0;
 377   }
 378
 379   bool
 380   ios_base::sync_with_stdio(bool __sync)
 381   {
 382 #ifdef _GLIBCPP_RESOLVE_LIB_DEFECTS
 383     // 49.  Underspecification of ios_base::sync_with_stdio
 384     bool __ret = ios_base::Init::_S_synced_with_stdio;
 385 #endif
 386
 387     // Turn off sync with C FILE* for cin, cout, cerr, clog iff
 388     // currently synchronized.
 389     if (!__sync && __ret)
 390       {
 391         ios_base::Init::_S_synced_with_stdio = __sync;
 392         ios_base::Init::_S_destroy_buffers();
 393         ios_base::Init::_S_create_buffers(__sync);
 394       }
 395     return __ret;
 396   }
 397 }  // namespace std