ios.cc revision 110614
1// Iostreams base classes -*- C++ -*- 2 3// Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002 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 45namespace __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 59namespace 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 int __out_size = __sync ? 0 : static_cast<int>(BUFSIZ); 163#ifdef _GLIBCPP_HAVE_ISATTY 164 int __in_size = (__sync || isatty (0)) ? 1 : static_cast<int>(BUFSIZ); 165#else 166 int __in_size = 1; 167#endif 168 169 // NB: The file globals.cc creates the four standard files 170 // with NULL buffers. At this point, we swap out the dummy NULL 171 // [io]stream objects and buffers with the real deal. 172 new (&buf_cout) stdio_filebuf<char>(stdout, ios_base::out, __out_size); 173 new (&buf_cin) stdio_filebuf<char>(stdin, ios_base::in, __in_size); 174 new (&buf_cerr) stdio_filebuf<char>(stderr, ios_base::out, __out_size); 175 new (&cout) ostream(&buf_cout); 176 new (&cin) istream(&buf_cin); 177 new (&cerr) ostream(&buf_cerr); 178 new (&clog) ostream(&buf_cerr); 179 cin.tie(&cout); 180 cerr.flags(ios_base::unitbuf); 181 182#ifdef _GLIBCPP_USE_WCHAR_T 183 new (&buf_wcout) stdio_filebuf<wchar_t>(stdout, ios_base::out, __out_size); 184 new (&buf_wcin) stdio_filebuf<wchar_t>(stdin, ios_base::in, __in_size); 185 new (&buf_wcerr) stdio_filebuf<wchar_t>(stderr, ios_base::out, __out_size); 186 new (&wcout) wostream(&buf_wcout); 187 new (&wcin) wistream(&buf_wcin); 188 new (&wcerr) wostream(&buf_wcerr); 189 new (&wclog) wostream(&buf_wcerr); 190 wcin.tie(&wcout); 191 wcerr.flags(ios_base::unitbuf); 192#endif 193 } 194 195 void 196 ios_base::Init::_S_ios_destroy() 197 { 198 // Explicitly call dtors to free any memory that is dynamically 199 // allocated by filebuf ctor or member functions, but don't 200 // deallocate all memory by calling operator delete. 201 buf_cout.~stdio_filebuf(); 202 buf_cin.~stdio_filebuf(); 203 buf_cerr.~stdio_filebuf(); 204 205#ifdef _GLIBCPP_USE_WCHAR_T 206 buf_wcout.~stdio_filebuf(); 207 buf_wcin.~stdio_filebuf(); 208 buf_wcerr.~stdio_filebuf(); 209#endif 210 } 211 212 ios_base::Init::Init() 213 { 214 if (_S_ios_base_init == 0) 215 { 216 // Standard streams default to synced with "C" operations. 217 ios_base::Init::_S_synced_with_stdio = true; 218 _S_ios_create(ios_base::Init::_S_synced_with_stdio); 219 } 220 ++_S_ios_base_init; 221 } 222 223 ios_base::Init::~Init() 224 { 225 if (--_S_ios_base_init == 0) 226 _S_ios_destroy(); 227 } 228 229 // 27.4.2.5 ios_base storage functions 230 int 231 ios_base::xalloc() throw() 232 { 233 // Implementation note: Initialize top to zero to ensure that 234 // initialization occurs before main() is started. 235 static _Atomic_word _S_top = 0; 236 return __exchange_and_add(&_S_top, 1) + 4; 237 } 238 239 // 27.4.2.5 iword/pword storage 240 ios_base::_Words& 241 ios_base::_M_grow_words(int ix) 242 { 243 // Precondition: _M_word_size <= ix 244 int newsize = _S_local_word_size; 245 _Words* words = _M_local_word; 246 if (ix > _S_local_word_size - 1) 247 { 248 if (ix < numeric_limits<int>::max()) 249 { 250 newsize = ix + 1; 251 try 252 { words = new _Words[newsize]; } 253 catch (...) 254 { 255 delete [] _M_word; 256 _M_word = 0; 257 _M_streambuf_state |= badbit; 258 if (_M_streambuf_state & _M_exception) 259 __throw_ios_failure("ios_base::_M_grow_words failure"); 260 return _M_word_zero; 261 } 262 for (int i = 0; i < _M_word_size; i++) 263 words[i] = _M_word[i]; 264 if (_M_word && _M_word != _M_local_word) 265 { 266 delete [] _M_word; 267 _M_word = 0; 268 } 269 } 270 else 271 { 272 _M_streambuf_state |= badbit; 273 return _M_word_zero; 274 } 275 } 276 _M_word = words; 277 _M_word_size = newsize; 278 return _M_word[ix]; 279 } 280 281 // Called only by basic_ios<>::init. 282 void 283 ios_base::_M_init() 284 { 285 // NB: May be called more than once 286 _M_precision = 6; 287 _M_width = 0; 288 _M_flags = skipws | dec; 289 _M_callbacks = 0; 290 _M_word_size = 0; 291 _M_ios_locale = locale(); 292 } 293 294 // 27.4.2.3 ios_base locale functions 295 locale 296 ios_base::imbue(const locale& __loc) 297 { 298 locale __old = _M_ios_locale; 299 _M_ios_locale = __loc; 300 _M_call_callbacks(imbue_event); 301 return __old; 302 } 303 304 ios_base::ios_base() : _M_callbacks(0), _M_word(0) 305 { 306 // Do nothing: basic_ios::init() does it. 307 // NB: _M_callbacks and _M_word must be zero for non-initialized 308 // ios_base to go through ~ios_base gracefully. 309 } 310 311 // 27.4.2.7 ios_base constructors/destructors 312 ios_base::~ios_base() 313 { 314 _M_call_callbacks(erase_event); 315 _M_dispose_callbacks(); 316 if (_M_word && _M_word != _M_local_word) 317 { 318 delete [] _M_word; 319 _M_word = 0; 320 } 321 } 322 323 void 324 ios_base::register_callback(event_callback __fn, int __index) 325 { _M_callbacks = new _Callback_list(__fn, __index, _M_callbacks); } 326 327 void 328 ios_base::_M_call_callbacks(event __e) throw() 329 { 330 _Callback_list* __p = _M_callbacks; 331 while (__p) 332 { 333 try 334 { (*__p->_M_fn) (__e, *this, __p->_M_index); } 335 catch (...) 336 { } 337 __p = __p->_M_next; 338 } 339 } 340 341 void 342 ios_base::_M_dispose_callbacks(void) 343 { 344 _Callback_list* __p = _M_callbacks; 345 while (__p && __p->_M_remove_reference() == 0) 346 { 347 _Callback_list* __next = __p->_M_next; 348 delete __p; 349 __p = __next; 350 } 351 _M_callbacks = 0; 352 } 353 354 bool 355 ios_base::sync_with_stdio(bool __sync) 356 { 357#ifdef _GLIBCPP_RESOLVE_LIB_DEFECTS 358 // 49. Underspecification of ios_base::sync_with_stdio 359 bool __ret = ios_base::Init::_S_synced_with_stdio; 360#endif 361 362 // Turn off sync with C FILE* for cin, cout, cerr, clog iff 363 // currently synchronized. 364 if (!__sync && __ret) 365 { 366 ios_base::Init::_S_synced_with_stdio = false; 367 ios_base::Init::_S_ios_destroy(); 368 ios_base::Init::_S_ios_create(ios_base::Init::_S_synced_with_stdio); 369 } 370 return __ret; 371 } 372} // namespace std 373