ios.cc

00001 // Iostreams base classes -*- C++ -*-
00002 
00003 // Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002
00004 // Free Software Foundation, Inc.
00005 //
00006 // This file is part of the GNU ISO C++ Library.  This library is free
00007 // software; you can redistribute it and/or modify it under the
00008 // terms of the GNU General Public License as published by the
00009 // Free Software Foundation; either version 2, or (at your option)
00010 // any later version.
00011 
00012 // This library is distributed in the hope that it will be useful,
00013 // but WITHOUT ANY WARRANTY; without even the implied warranty of
00014 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00015 // GNU General Public License for more details.
00016 
00017 // You should have received a copy of the GNU General Public License along
00018 // with this library; see the file COPYING.  If not, write to the Free
00019 // Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
00020 // USA.
00021 
00022 // As a special exception, you may use this file as part of a free software
00023 // library without restriction.  Specifically, if other files instantiate
00024 // templates or use macros or inline functions from this file, or you compile
00025 // this file and link it with other files to produce an executable, this
00026 // file does not by itself cause the resulting executable to be covered by
00027 // the GNU General Public License.  This exception does not however
00028 // invalidate any other reasons why the executable file might be covered by
00029 // the GNU General Public License.
00030 
00031 //
00032 // ISO C++ 14882: 27.4  Iostreams base classes
00033 //
00034 
00035 #include <ios>
00036 #include <ostream>
00037 #include <istream>
00038 #include <fstream>
00039 #include <bits/atomicity.h>
00040 #include <ext/stdio_filebuf.h>
00041 #ifdef _GLIBCPP_HAVE_UNISTD_H
00042 #include <unistd.h>
00043 #endif
00044 
00045 namespace __gnu_cxx
00046 {
00047   // Extern declarations for global objects in src/globals.cc.
00048   extern stdio_filebuf<char> buf_cout;
00049   extern stdio_filebuf<char> buf_cin;
00050   extern stdio_filebuf<char> buf_cerr;
00051   extern std::__locale_cache<char> locale_cache_cout;
00052   extern std::__locale_cache<char> locale_cache_cin;
00053   extern std::__locale_cache<char> locale_cache_cerr;
00054   extern std::__locale_cache<char> locale_cache_clog;
00055 
00056 #ifdef _GLIBCPP_USE_WCHAR_T
00057   extern stdio_filebuf<wchar_t> buf_wcout;
00058   extern stdio_filebuf<wchar_t> buf_wcin;
00059   extern stdio_filebuf<wchar_t> buf_wcerr;
00060   extern std::__locale_cache<wchar_t> locale_cache_wcout;
00061   extern std::__locale_cache<wchar_t> locale_cache_wcin;
00062   extern std::__locale_cache<wchar_t> locale_cache_wcerr;
00063   extern std::__locale_cache<wchar_t> locale_cache_wclog;
00064 #endif
00065 } // namespace __gnu_cxx
00066 
00067 namespace std 
00068 {
00069   using namespace __gnu_cxx;
00070   
00071   extern istream cin;
00072   extern ostream cout;
00073   extern ostream cerr;
00074   extern ostream clog;
00075 
00076 #ifdef _GLIBCPP_USE_WCHAR_T
00077   extern wistream wcin;
00078   extern wostream wcout;
00079   extern wostream wcerr;
00080   extern wostream wclog;
00081 #endif
00082 
00083   // Definitions for static const data members of __ios_flags.
00084   const __ios_flags::__int_type __ios_flags::_S_boolalpha;
00085   const __ios_flags::__int_type __ios_flags::_S_dec;
00086   const __ios_flags::__int_type __ios_flags::_S_fixed;
00087   const __ios_flags::__int_type __ios_flags::_S_hex;
00088   const __ios_flags::__int_type __ios_flags::_S_internal;
00089   const __ios_flags::__int_type __ios_flags::_S_left;
00090   const __ios_flags::__int_type __ios_flags::_S_oct;
00091   const __ios_flags::__int_type __ios_flags::_S_right;
00092   const __ios_flags::__int_type __ios_flags::_S_scientific;
00093   const __ios_flags::__int_type __ios_flags::_S_showbase;
00094   const __ios_flags::__int_type __ios_flags::_S_showpoint;
00095   const __ios_flags::__int_type __ios_flags::_S_showpos;
00096   const __ios_flags::__int_type __ios_flags::_S_skipws;
00097   const __ios_flags::__int_type __ios_flags::_S_unitbuf;
00098   const __ios_flags::__int_type __ios_flags::_S_uppercase;
00099   const __ios_flags::__int_type __ios_flags::_S_adjustfield;
00100   const __ios_flags::__int_type __ios_flags::_S_basefield;
00101   const __ios_flags::__int_type __ios_flags::_S_floatfield;
00102 
00103   const __ios_flags::__int_type __ios_flags::_S_badbit;
00104   const __ios_flags::__int_type __ios_flags::_S_eofbit;
00105   const __ios_flags::__int_type __ios_flags::_S_failbit;
00106 
00107   const __ios_flags::__int_type __ios_flags::_S_app;
00108   const __ios_flags::__int_type __ios_flags::_S_ate;
00109   const __ios_flags::__int_type __ios_flags::_S_bin;
00110   const __ios_flags::__int_type __ios_flags::_S_in;
00111   const __ios_flags::__int_type __ios_flags::_S_out;
00112   const __ios_flags::__int_type __ios_flags::_S_trunc;
00113 
00114   // Definitions for static const members of ios_base.
00115   const ios_base::fmtflags ios_base::boolalpha;
00116   const ios_base::fmtflags ios_base::dec;
00117   const ios_base::fmtflags ios_base::fixed;
00118   const ios_base::fmtflags ios_base::hex;
00119   const ios_base::fmtflags ios_base::internal;
00120   const ios_base::fmtflags ios_base::left;
00121   const ios_base::fmtflags ios_base::oct;
00122   const ios_base::fmtflags ios_base::right;
00123   const ios_base::fmtflags ios_base::scientific;
00124   const ios_base::fmtflags ios_base::showbase;
00125   const ios_base::fmtflags ios_base::showpoint;
00126   const ios_base::fmtflags ios_base::showpos;
00127   const ios_base::fmtflags ios_base::skipws;
00128   const ios_base::fmtflags ios_base::unitbuf;
00129   const ios_base::fmtflags ios_base::uppercase;
00130   const ios_base::fmtflags ios_base::adjustfield;
00131   const ios_base::fmtflags ios_base::basefield;
00132   const ios_base::fmtflags ios_base::floatfield;
00133 
00134   const ios_base::iostate ios_base::badbit;
00135   const ios_base::iostate ios_base::eofbit;
00136   const ios_base::iostate ios_base::failbit;
00137   const ios_base::iostate ios_base::goodbit;
00138 
00139   const ios_base::openmode ios_base::app;
00140   const ios_base::openmode ios_base::ate;
00141   const ios_base::openmode ios_base::binary;
00142   const ios_base::openmode ios_base::in;
00143   const ios_base::openmode ios_base::out;
00144   const ios_base::openmode ios_base::trunc;
00145 
00146   const ios_base::seekdir ios_base::beg;
00147   const ios_base::seekdir ios_base::cur;
00148   const ios_base::seekdir ios_base::end;
00149 
00150   const int ios_base::_S_local_word_size;
00151   int ios_base::Init::_S_ios_base_init = 0;
00152   bool ios_base::Init::_S_synced_with_stdio = true;
00153 
00154   ios_base::failure::failure(const string& __str) throw()
00155   {
00156     strncpy(_M_name, __str.c_str(), _M_bufsize);
00157     _M_name[_M_bufsize - 1] = '\0';
00158   }
00159 
00160   ios_base::failure::~failure() throw()
00161   { }
00162 
00163   const char*
00164   ios_base::failure::what() const throw()
00165   { return _M_name; }
00166 
00167   void
00168   ios_base::Init::_S_ios_create(bool __sync)
00169   {
00170     size_t __out_size = __sync ? 0 : static_cast<size_t>(BUFSIZ);
00171 #ifdef _GLIBCPP_HAVE_ISATTY
00172     size_t __in_size =
00173       (__sync || isatty (0)) ? 1 : static_cast<size_t>(BUFSIZ);
00174 #else
00175     size_t __in_size = 1;
00176 #endif
00177 
00178     // NB: The file globals.cc creates the four standard files
00179     // with NULL buffers. At this point, we swap out the dummy NULL
00180     // [io]stream objects and buffers with the real deal.
00181     new (&buf_cout) stdio_filebuf<char>(stdout, ios_base::out, __out_size);
00182     new (&buf_cin) stdio_filebuf<char>(stdin, ios_base::in, __in_size);
00183     new (&buf_cerr) stdio_filebuf<char>(stderr, ios_base::out, __out_size);
00184 
00185     new (&cout) ostream(&buf_cout);
00186     new (&cin) istream(&buf_cin);
00187     new (&cerr) ostream(&buf_cerr);
00188     new (&clog) ostream(&buf_cerr);
00189     cout.init(&buf_cout, &locale_cache_cout);
00190     cin.init(&buf_cin, &locale_cache_cin);
00191     cerr.init(&buf_cerr, &locale_cache_cerr);
00192     clog.init(&buf_cerr, &locale_cache_clog);
00193     cin.tie(&cout);
00194     cerr.flags(ios_base::unitbuf);
00195     
00196 #ifdef _GLIBCPP_USE_WCHAR_T
00197     new (&buf_wcout) stdio_filebuf<wchar_t>(stdout, ios_base::out, __out_size);
00198     new (&buf_wcin) stdio_filebuf<wchar_t>(stdin, ios_base::in, __in_size);
00199     new (&buf_wcerr) stdio_filebuf<wchar_t>(stderr, ios_base::out, __out_size);
00200     new (&wcout) wostream(&buf_wcout);
00201     new (&wcin) wistream(&buf_wcin);
00202     new (&wcerr) wostream(&buf_wcerr);
00203     new (&wclog) wostream(&buf_wcerr);
00204     wcout.init(&buf_wcout, &locale_cache_wcout);
00205     wcin.init(&buf_wcin, &locale_cache_wcin);
00206     wcerr.init(&buf_wcerr, &locale_cache_wcerr);
00207     wclog.init(&buf_wcerr, &locale_cache_wclog);
00208     wcin.tie(&wcout);
00209     wcerr.flags(ios_base::unitbuf);
00210 #endif
00211   }
00212 
00213   void
00214   ios_base::Init::_S_ios_destroy()
00215   {
00216     // Explicitly call dtors to free any memory that is dynamically
00217     // allocated by filebuf ctor or member functions, but don't
00218     // deallocate all memory by calling operator delete.
00219     buf_cout.~stdio_filebuf();
00220     buf_cin.~stdio_filebuf();
00221     buf_cerr.~stdio_filebuf();
00222 
00223 #ifdef _GLIBCPP_USE_WCHAR_T
00224     buf_wcout.~stdio_filebuf();
00225     buf_wcin.~stdio_filebuf();
00226     buf_wcerr.~stdio_filebuf();
00227 #endif
00228   }
00229 
00230   ios_base::Init::Init()
00231   {
00232     if (_S_ios_base_init == 0)
00233       {
00234     // Standard streams default to synced with "C" operations.
00235     ios_base::Init::_S_synced_with_stdio = true;
00236     _S_ios_create(ios_base::Init::_S_synced_with_stdio);
00237       }
00238     ++_S_ios_base_init;
00239   }
00240 
00241   ios_base::Init::~Init()
00242   {
00243     if (--_S_ios_base_init == 0)
00244       _S_ios_destroy();
00245   } 
00246 
00247   // 27.4.2.5  ios_base storage functions
00248   int 
00249   ios_base::xalloc() throw()
00250   {
00251     // Implementation note: Initialize top to zero to ensure that
00252     // initialization occurs before main() is started.
00253     static _Atomic_word _S_top = 0; 
00254     return __exchange_and_add(&_S_top, 1) + 4;
00255   }
00256 
00257   // 27.4.2.5  iword/pword storage
00258   ios_base::_Words&
00259   ios_base::_M_grow_words(int ix)
00260   {
00261     // Precondition: _M_word_size <= ix
00262     int newsize = _S_local_word_size;
00263     _Words* words = _M_local_word;
00264     if (ix > _S_local_word_size - 1)
00265       {
00266     if (ix < numeric_limits<int>::max())
00267       {
00268         newsize = ix + 1;
00269         try
00270           { words = new _Words[newsize]; }
00271         catch (...)
00272           {
00273         _M_streambuf_state |= badbit;
00274         if (_M_streambuf_state & _M_exception)
00275           __throw_ios_failure("ios_base::_M_grow_words failure");
00276         return _M_word_zero;
00277           }
00278         for (int i = 0; i < _M_word_size; i++) 
00279           words[i] = _M_word[i];
00280         if (_M_word && _M_word != _M_local_word) 
00281           {
00282         delete [] _M_word;
00283         _M_word = 0;
00284           }
00285       }
00286     else
00287       {
00288         _M_streambuf_state |= badbit;
00289         if (_M_streambuf_state & _M_exception)
00290           __throw_ios_failure("ios_base::_M_grow_words failure");
00291         return _M_word_zero;
00292       }
00293       }
00294     _M_word = words;
00295     _M_word_size = newsize;
00296     return _M_word[ix];
00297   }
00298   
00299   // Called only by basic_ios<>::init.
00300   void 
00301   ios_base::_M_init()   
00302   {
00303     // NB: May be called more than once
00304     _M_precision = 6;
00305     _M_width = 0;
00306     _M_flags = skipws | dec;
00307     _M_ios_locale = locale();
00308   }  
00309   
00310   // 27.4.2.3  ios_base locale functions
00311   locale
00312   ios_base::imbue(const locale& __loc)
00313   {
00314     locale __old = _M_ios_locale;
00315     _M_ios_locale = __loc;
00316     _M_call_callbacks(imbue_event);
00317     return __old;
00318   }
00319 
00320   ios_base::ios_base() : _M_callbacks(0), _M_word_size(_S_local_word_size),
00321              _M_word(_M_local_word)
00322   {
00323     // Do nothing: basic_ios::init() does it.  
00324     // NB: _M_callbacks and _M_word must be zero for non-initialized
00325     // ios_base to go through ~ios_base gracefully.
00326   }
00327   
00328   // 27.4.2.7  ios_base constructors/destructors
00329   ios_base::~ios_base()
00330   {
00331     _M_call_callbacks(erase_event);
00332     _M_dispose_callbacks();
00333     if (_M_word != _M_local_word) 
00334       {
00335     delete [] _M_word;
00336     _M_word = 0;
00337       }
00338   }
00339 
00340   void 
00341   ios_base::register_callback(event_callback __fn, int __index)
00342   { _M_callbacks = new _Callback_list(__fn, __index, _M_callbacks); }
00343 
00344   void 
00345   ios_base::_M_call_callbacks(event __e) throw()
00346   {
00347     _Callback_list* __p = _M_callbacks;
00348     while (__p)
00349       {
00350     try 
00351       { (*__p->_M_fn) (__e, *this, __p->_M_index); } 
00352     catch (...) 
00353       { }
00354     __p = __p->_M_next;
00355       }
00356   }
00357 
00358   void 
00359   ios_base::_M_dispose_callbacks(void)
00360   {
00361     _Callback_list* __p = _M_callbacks;
00362     while (__p && __p->_M_remove_reference() == 0)
00363       {
00364     _Callback_list* __next = __p->_M_next;
00365     delete __p;
00366     __p = __next;
00367       }
00368     _M_callbacks = 0;
00369   }
00370 
00371   bool 
00372   ios_base::sync_with_stdio(bool __sync)
00373   { 
00374 #ifdef _GLIBCPP_RESOLVE_LIB_DEFECTS
00375     // 49.  Underspecification of ios_base::sync_with_stdio
00376     bool __ret = ios_base::Init::_S_synced_with_stdio;
00377 #endif
00378 
00379     // Turn off sync with C FILE* for cin, cout, cerr, clog iff
00380     // currently synchronized.
00381     if (!__sync && __ret)
00382       {
00383     ios_base::Init::_S_synced_with_stdio = false;
00384     ios_base::Init::_S_ios_destroy();
00385     ios_base::Init::_S_ios_create(ios_base::Init::_S_synced_with_stdio);
00386       }
00387     return __ret; 
00388   }
00389 }  // namespace std

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