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