libstdc++-v3/src/ios.cc

   1 // Iostreams base classes -*- C++ -*-
   2
   3 // Copyright (C) 1997, 1998, 1999, 2000, 2001 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 2, 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 // You should have received a copy of the GNU General Public License along
  17 // with this library; see the file COPYING.  If not, write to the Free
  18 // Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
  19 // USA.
  20
  21 // As a special exception, you may use this file as part of a free software
  22 // library without restriction.  Specifically, if other files instantiate
  23 // templates or use macros or inline functions from this file, or you compile
  24 // this file and link it with other files to produce an executable, this
  25 // file does not by itself cause the resulting executable to be covered by
  26 // the GNU General Public License.  This exception does not however
  27 // invalidate any other reasons why the executable file might be covered by
  28 // the GNU General Public License.
  29
  30 //
  31 // ISO C++ 14882: 27.4  Iostreams base classes
  32 //
  33
  34 #include <ios>
  35 #include <ostream>
  36 #include <istream>
  37 #include <fstream>
  38
  39 namespace std
  40 {
  41   // Extern declarations for global objects in src/globals.cc.
  42   extern istream cin;
  43   extern ostream cout;
  44   extern ostream cerr;
  45   extern ostream clog;
  46   extern filebuf buf_cout;
  47   extern filebuf buf_cin;
  48   extern filebuf buf_cerr;
  49
  50 #ifdef _GLIBCPP_USE_WCHAR_T
  51   extern wistream wcin;
  52   extern wostream wcout;
  53   extern wostream wcerr;
  54   extern wostream wclog;
  55   extern wfilebuf buf_wcout;
  56   extern wfilebuf buf_wcin;
  57   extern wfilebuf buf_wcerr;
  58 #endif
  59
  60   // Definitions for static const data members of __ios_flags.
  61   const __ios_flags::__int_type __ios_flags::_S_boolalpha;
  62   const __ios_flags::__int_type __ios_flags::_S_dec;
  63   const __ios_flags::__int_type __ios_flags::_S_fixed;
  64   const __ios_flags::__int_type __ios_flags::_S_hex;
  65   const __ios_flags::__int_type __ios_flags::_S_internal;
  66   const __ios_flags::__int_type __ios_flags::_S_left;
  67   const __ios_flags::__int_type __ios_flags::_S_oct;
  68   const __ios_flags::__int_type __ios_flags::_S_right;
  69   const __ios_flags::__int_type __ios_flags::_S_scientific;
  70   const __ios_flags::__int_type __ios_flags::_S_showbase;
  71   const __ios_flags::__int_type __ios_flags::_S_showpoint;
  72   const __ios_flags::__int_type __ios_flags::_S_showpos;
  73   const __ios_flags::__int_type __ios_flags::_S_skipws;
  74   const __ios_flags::__int_type __ios_flags::_S_unitbuf;
  75   const __ios_flags::__int_type __ios_flags::_S_uppercase;
  76   const __ios_flags::__int_type __ios_flags::_S_adjustfield;
  77   const __ios_flags::__int_type __ios_flags::_S_basefield;
  78   const __ios_flags::__int_type __ios_flags::_S_floatfield;
  79
  80   const __ios_flags::__int_type __ios_flags::_S_badbit;
  81   const __ios_flags::__int_type __ios_flags::_S_eofbit;
  82   const __ios_flags::__int_type __ios_flags::_S_failbit;
  83
  84   const __ios_flags::__int_type __ios_flags::_S_app;
  85   const __ios_flags::__int_type __ios_flags::_S_ate;
  86   const __ios_flags::__int_type __ios_flags::_S_bin;
  87   const __ios_flags::__int_type __ios_flags::_S_in;
  88   const __ios_flags::__int_type __ios_flags::_S_out;
  89   const __ios_flags::__int_type __ios_flags::_S_trunc;
  90
  91   // Definitions for static const members of ios_base.
  92   const ios_base::fmtflags ios_base::boolalpha;
  93   const ios_base::fmtflags ios_base::dec;
  94   const ios_base::fmtflags ios_base::fixed;
  95   const ios_base::fmtflags ios_base::hex;
  96   const ios_base::fmtflags ios_base::internal;
  97   const ios_base::fmtflags ios_base::left;
  98   const ios_base::fmtflags ios_base::oct;
  99   const ios_base::fmtflags ios_base::right;
 100   const ios_base::fmtflags ios_base::scientific;
 101   const ios_base::fmtflags ios_base::showbase;
 102   const ios_base::fmtflags ios_base::showpoint;
 103   const ios_base::fmtflags ios_base::showpos;
 104   const ios_base::fmtflags ios_base::skipws;
 105   const ios_base::fmtflags ios_base::unitbuf;
 106   const ios_base::fmtflags ios_base::uppercase;
 107   const ios_base::fmtflags ios_base::adjustfield;
 108   const ios_base::fmtflags ios_base::basefield;
 109   const ios_base::fmtflags ios_base::floatfield;
 110
 111   const ios_base::iostate ios_base::badbit;
 112   const ios_base::iostate ios_base::eofbit;
 113   const ios_base::iostate ios_base::failbit;
 114   const ios_base::iostate ios_base::goodbit;
 115
 116   const ios_base::openmode ios_base::app;
 117   const ios_base::openmode ios_base::ate;
 118   const ios_base::openmode ios_base::binary;
 119   const ios_base::openmode ios_base::in;
 120   const ios_base::openmode ios_base::out;
 121   const ios_base::openmode ios_base::trunc;
 122
 123   const ios_base::seekdir ios_base::beg;
 124   const ios_base::seekdir ios_base::cur;
 125   const ios_base::seekdir ios_base::end;
 126
 127   const int ios_base::_S_local_words;
 128   int ios_base::Init::_S_ios_base_init = 0;
 129   bool ios_base::Init::_S_synced_with_stdio = true;
 130
 131   ios_base::failure::failure(const string& __str) throw()
 132   {
 133     strncpy(_M_name, __str.c_str(), _M_bufsize);
 134     _M_name[_M_bufsize - 1] = '\0';
 135   }
 136
 137   ios_base::failure::~failure() throw()
 138   { }
 139
 140   const char*
 141   ios_base::failure::what() const throw()
 142   { return _M_name; }
 143
 144   void
 145   ios_base::Init::_S_ios_create(bool __sync)
 146   {
 147     int __out_bufsize = __sync ? 0 : static_cast<int>(BUFSIZ);
 148     int __in_bufsize = __sync ? 1 : static_cast<int>(BUFSIZ);
 149
 150 #if _GLIBCPP_AVOID_FSEEK
 151     // Platforms that prefer to avoid fseek() calls on streams only
 152     // get their desire when the C++-layer input buffer size is 1.
 153     // This hack hurts performance but keeps correctness across
 154     // all types of streams that might be attached to (e.g.) cin.
 155     __in_bufsize = 1;
 156 #endif
 157
 158     // NB: The file globals.cc creates the four standard files
 159     // with NULL buffers. At this point, we swap out the dummy NULL
 160     // [io]stream objects and buffers with the real deal.
 161     new (&buf_cout) filebuf(stdout, ios_base::out, __out_bufsize);
 162     new (&buf_cin) filebuf(stdin, ios_base::in, __in_bufsize);
 163     new (&buf_cerr) filebuf(stderr, ios_base::out, __out_bufsize);
 164     new (&cout) ostream(&buf_cout);
 165     new (&cin) istream(&buf_cin);
 166     new (&cerr) ostream(&buf_cerr);
 167     new (&clog) ostream(&buf_cerr);
 168     cin.tie(&cout);
 169     cerr.flags(ios_base::unitbuf);
 170
 171 #ifdef _GLIBCPP_USE_WCHAR_T
 172     new (&buf_wcout) wfilebuf(stdout, ios_base::out, __out_bufsize);
 173     new (&buf_wcin) wfilebuf(stdin, ios_base::in, __in_bufsize);
 174     new (&buf_wcerr) wfilebuf(stderr, ios_base::out, __out_bufsize);
 175     new (&wcout) wostream(&buf_wcout);
 176     new (&wcin) wistream(&buf_wcin);
 177     new (&wcerr) wostream(&buf_wcerr);
 178     new (&wclog) wostream(&buf_wcerr);
 179     wcin.tie(&wcout);
 180     wcerr.flags(ios_base::unitbuf);
 181 #endif
 182   }
 183
 184   void
 185   ios_base::Init::_S_ios_destroy()
 186   {
 187     // Explicitly call dtors to free any memory that is dynamically
 188     // allocated by filebuf ctor or member functions, but don't
 189     // deallocate all memory by calling operator delete.
 190     cout.flush();
 191     cerr.flush();
 192     clog.flush();
 193     buf_cout.~filebuf();
 194     buf_cin.~filebuf();
 195     buf_cerr.~filebuf();
 196 #ifdef _GLIBCPP_USE_WCHAR_T
 197     wcout.flush();
 198     wcerr.flush();
 199     wclog.flush();
 200     buf_wcout.~wfilebuf();
 201     buf_wcin.~wfilebuf();
 202     buf_wcerr.~wfilebuf();
 203 #endif
 204   }
 205
 206   ios_base::Init::Init()
 207   {
 208     if (_S_ios_base_init == 0)
 209       {
 210         // Standard streams default to synced with "C" operations.
 211         ios_base::Init::_S_synced_with_stdio = true;
 212         _S_ios_create(ios_base::Init::_S_synced_with_stdio);
 213       }
 214     ++_S_ios_base_init;
 215   }
 216
 217   ios_base::Init::~Init()
 218   {
 219     if (--_S_ios_base_init == 0)
 220       _S_ios_destroy();
 221   }
 222
 223   // 27.4.2.5  ios_base storage functions
 224   int
 225   ios_base::xalloc() throw()
 226   {
 227     // XXX MT
 228     // XXX should be a symbol. (Reserve 0..3 for builtins.)
 229     static int top = 4;
 230     return top++;
 231   }
 232
 233   // 27.4.2.5  iword/pword storage
 234   ios_base::_Words&
 235   ios_base::_M_grow_words(int ix)
 236   {
 237     // Precondition: _M_word_limit <= ix
 238     _Words zero = { 0, 0 };
 239     int newlimit = _S_local_words;
 240     _Words* words = _M_word_array;
 241     int i = 0;
 242     if (_S_local_words <= ix)
 243       {
 244         newlimit = ix+1;
 245         try
 246           { words = new _Words[ix+1]; }
 247         catch (...)
 248           {
 249             _M_dummy = zero;  // XXX MT? Not on "normal" machines.
 250             // XXX now in basic_ios
 251             // _M_clear(_M_rdstate() | badbit);  // may throw
 252             return _M_dummy;
 253           }
 254         for (; i < _M_word_limit; i++)
 255           words[i] = _M_words[i];
 256         if (_M_words != _M_word_array)
 257           delete [] _M_words;
 258       }
 259
 260     do { words[i] = zero; } while (++i < newlimit);
 261     _M_words = words;
 262     _M_word_limit = newlimit;
 263     return words[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_callbacks = 0;
 275     _M_words = 0;
 276     _M_word_limit = 0;
 277     _M_ios_locale = locale();
 278     // No init needed for _M_word_array or _M_dummy.
 279   }
 280
 281   // 27.4.2.3  ios_base locale functions
 282   locale
 283   ios_base::imbue(const locale& __loc)
 284   {
 285     locale __old = _M_ios_locale;
 286     _M_ios_locale = __loc;
 287     _M_call_callbacks(imbue_event);
 288     return __old;
 289   }
 290
 291   ios_base::ios_base()
 292   {
 293     // Do nothing; init() does it.  Static init to 0 makes everything sane.
 294   }
 295
 296   // 27.4.2.7  ios_base constructors/destructors
 297   ios_base::~ios_base()
 298   {
 299     _M_call_callbacks(erase_event);
 300     _M_dispose_callbacks();
 301     if (_M_words != _M_word_array)
 302       delete [] _M_words;
 303     // XXX done?
 304   }
 305
 306   void
 307   ios_base::register_callback(event_callback __fn, int __index)
 308   { _M_callbacks = new _Callback_list(__fn, __index, _M_callbacks); }
 309
 310   void
 311   ios_base::_M_call_callbacks(event __e) throw()
 312   {
 313     for (_Callback_list* __p = _M_callbacks; __p; __p = __p->_M_next)
 314       {
 315         try {
 316           (*__p->_M_fn) (__e, *this, __p->_M_index);
 317         }
 318         catch (...) {
 319         }
 320       }
 321   }
 322
 323   void
 324   ios_base::_M_dispose_callbacks(void)
 325   {
 326     _Callback_list* __p = _M_callbacks;
 327     while (__p && __p->_M_remove_reference() == 0)
 328       {
 329         _Callback_list* __next = __p->_M_next;
 330         delete __p;
 331         __p = __next;
 332       }
 333     _M_callbacks = 0;
 334   }
 335
 336   bool
 337   ios_base::sync_with_stdio(bool __sync)
 338   {
 339 #ifdef _GLIBCPP_RESOLVE_LIB_DEFECTS
 340     // 49.  Underspecification of ios_base::sync_with_stdio
 341     bool __ret = ios_base::Init::_S_synced_with_stdio;
 342 #endif
 343
 344     // Turn off sync with C FILE* for cin, cout, cerr, clog iff
 345     // currently synchronized.
 346     if (!__sync && __ret)
 347       {
 348         ios_base::Init::_S_synced_with_stdio = false;
 349         ios_base::Init::_S_ios_destroy();
 350         ios_base::Init::_S_ios_create(ios_base::Init::_S_synced_with_stdio);
 351       }
 352     return __ret;
 353   }
 354 }  // namespace std
 355