1 // Iostreams base classes -*- C++ -*- 2 3 // Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 4 // 2006, 2007, 2008, 2009, 2010, 2011 5 // Free Software Foundation, Inc. 6 // 7 // This file is part of the GNU ISO C++ Library. This library is free 8 // software; you can redistribute it and/or modify it under the 9 // terms of the GNU General Public License as published by the 10 // Free Software Foundation; either version 3, or (at your option) 11 // any later version. 12 13 // This library is distributed in the hope that it will be useful, 14 // but WITHOUT ANY WARRANTY; without even the implied warranty of 15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 // GNU General Public License for more details. 17 18 // Under Section 7 of GPL version 3, you are granted additional 19 // permissions described in the GCC Runtime Library Exception, version 20 // 3.1, as published by the Free Software Foundation. 21 22 // You should have received a copy of the GNU General Public License and 23 // a copy of the GCC Runtime Library Exception along with this program; 24 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 25 // <http://www.gnu.org/licenses/>. 26 27 // 28 // ISO C++ 14882: 27.4 Iostreams base classes 29 // 30 31 #include <ios> 32 #include <ostream> 33 #include <istream> 34 #include <fstream> 35 #include <ext/stdio_filebuf.h> 36 #include <ext/stdio_sync_filebuf.h> 37 38 namespace __gnu_internal _GLIBCXX_VISIBILITY(hidden) 39 { 40 using namespace __gnu_cxx; 41 42 // Extern declarations for global objects in src/globals.cc. 43 extern stdio_sync_filebuf<char> buf_cout_sync; 44 extern stdio_sync_filebuf<char> buf_cin_sync; 45 extern stdio_sync_filebuf<char> buf_cerr_sync; 46 47 extern stdio_filebuf<char> buf_cout; 48 extern stdio_filebuf<char> buf_cin; 49 extern stdio_filebuf<char> buf_cerr; 50 51 #ifdef _GLIBCXX_USE_WCHAR_T 52 extern stdio_sync_filebuf<wchar_t> buf_wcout_sync; 53 extern stdio_sync_filebuf<wchar_t> buf_wcin_sync; 54 extern stdio_sync_filebuf<wchar_t> buf_wcerr_sync; 55 56 extern stdio_filebuf<wchar_t> buf_wcout; 57 extern stdio_filebuf<wchar_t> buf_wcin; 58 extern stdio_filebuf<wchar_t> buf_wcerr; 59 #endif 60 } // namespace __gnu_internal 61 62 namespace std _GLIBCXX_VISIBILITY(default) 63 { 64 _GLIBCXX_BEGIN_NAMESPACE_VERSION 65 66 using namespace __gnu_internal; 67 68 extern istream cin; 69 extern ostream cout; 70 extern ostream cerr; 71 extern ostream clog; 72 73 #ifdef _GLIBCXX_USE_WCHAR_T 74 extern wistream wcin; 75 extern wostream wcout; 76 extern wostream wcerr; 77 extern wostream wclog; 78 #endif 79 80 ios_base::Init::Init() 81 { 82 if (__gnu_cxx::__exchange_and_add_dispatch(&_S_refcount, 1) == 0) 83 { 84 // Standard streams default to synced with "C" operations. 85 _S_synced_with_stdio = true; 86 87 new (&buf_cout_sync) stdio_sync_filebuf<char>(stdout); 88 new (&buf_cin_sync) stdio_sync_filebuf<char>(stdin); 89 new (&buf_cerr_sync) stdio_sync_filebuf<char>(stderr); 90 91 // The standard streams are constructed once only and never 92 // destroyed. 93 new (&cout) ostream(&buf_cout_sync); 94 new (&cin) istream(&buf_cin_sync); 95 new (&cerr) ostream(&buf_cerr_sync); 96 new (&clog) ostream(&buf_cerr_sync); 97 cin.tie(&cout); 98 cerr.setf(ios_base::unitbuf); 99 // _GLIBCXX_RESOLVE_LIB_DEFECTS 100 // 455. cerr::tie() and wcerr::tie() are overspecified. 101 cerr.tie(&cout); 102 103 #ifdef _GLIBCXX_USE_WCHAR_T 104 new (&buf_wcout_sync) stdio_sync_filebuf<wchar_t>(stdout); 105 new (&buf_wcin_sync) stdio_sync_filebuf<wchar_t>(stdin); 106 new (&buf_wcerr_sync) stdio_sync_filebuf<wchar_t>(stderr); 107 108 new (&wcout) wostream(&buf_wcout_sync); 109 new (&wcin) wistream(&buf_wcin_sync); 110 new (&wcerr) wostream(&buf_wcerr_sync); 111 new (&wclog) wostream(&buf_wcerr_sync); 112 wcin.tie(&wcout); 113 wcerr.setf(ios_base::unitbuf); 114 wcerr.tie(&wcout); 115 #endif 116 117 // NB: Have to set refcount above one, so that standard 118 // streams are not re-initialized with uses of ios_base::Init 119 // besides <iostream> static object, ie just using <ios> with 120 // ios_base::Init objects. 121 __gnu_cxx::__atomic_add_dispatch(&_S_refcount, 1); 122 } 123 } 124 125 ios_base::Init::~Init() 126 { 127 // Be race-detector-friendly. For more info see bits/c++config. 128 _GLIBCXX_SYNCHRONIZATION_HAPPENS_BEFORE(&_S_refcount); 129 if (__gnu_cxx::__exchange_and_add_dispatch(&_S_refcount, -1) == 2) 130 { 131 _GLIBCXX_SYNCHRONIZATION_HAPPENS_AFTER(&_S_refcount); 132 // Catch any exceptions thrown by basic_ostream::flush() 133 __try 134 { 135 // Flush standard output streams as required by 27.4.2.1.6 136 cout.flush(); 137 cerr.flush(); 138 clog.flush(); 139 140 #ifdef _GLIBCXX_USE_WCHAR_T 141 wcout.flush(); 142 wcerr.flush(); 143 wclog.flush(); 144 #endif 145 } 146 __catch(...) 147 { } 148 } 149 } 150 151 bool 152 ios_base::sync_with_stdio(bool __sync) 153 { 154 // _GLIBCXX_RESOLVE_LIB_DEFECTS 155 // 49. Underspecification of ios_base::sync_with_stdio 156 bool __ret = ios_base::Init::_S_synced_with_stdio; 157 158 // Turn off sync with C FILE* for cin, cout, cerr, clog iff 159 // currently synchronized. 160 if (!__sync && __ret) 161 { 162 // Make sure the standard streams are constructed. 163 ios_base::Init __init; 164 165 ios_base::Init::_S_synced_with_stdio = __sync; 166 167 // Explicitly call dtors to free any memory that is 168 // dynamically allocated by filebuf ctor or member functions, 169 // but don't deallocate all memory by calling operator delete. 170 buf_cout_sync.~stdio_sync_filebuf<char>(); 171 buf_cin_sync.~stdio_sync_filebuf<char>(); 172 buf_cerr_sync.~stdio_sync_filebuf<char>(); 173 174 #ifdef _GLIBCXX_USE_WCHAR_T 175 buf_wcout_sync.~stdio_sync_filebuf<wchar_t>(); 176 buf_wcin_sync.~stdio_sync_filebuf<wchar_t>(); 177 buf_wcerr_sync.~stdio_sync_filebuf<wchar_t>(); 178 #endif 179 180 // Create stream buffers for the standard streams and use 181 // those buffers without destroying and recreating the 182 // streams. 183 new (&buf_cout) stdio_filebuf<char>(stdout, ios_base::out); 184 new (&buf_cin) stdio_filebuf<char>(stdin, ios_base::in); 185 new (&buf_cerr) stdio_filebuf<char>(stderr, ios_base::out); 186 cout.rdbuf(&buf_cout); 187 cin.rdbuf(&buf_cin); 188 cerr.rdbuf(&buf_cerr); 189 clog.rdbuf(&buf_cerr); 190 191 #ifdef _GLIBCXX_USE_WCHAR_T 192 new (&buf_wcout) stdio_filebuf<wchar_t>(stdout, ios_base::out); 193 new (&buf_wcin) stdio_filebuf<wchar_t>(stdin, ios_base::in); 194 new (&buf_wcerr) stdio_filebuf<wchar_t>(stderr, ios_base::out); 195 wcout.rdbuf(&buf_wcout); 196 wcin.rdbuf(&buf_wcin); 197 wcerr.rdbuf(&buf_wcerr); 198 wclog.rdbuf(&buf_wcerr); 199 #endif 200 } 201 return __ret; 202 } 203 204 _GLIBCXX_END_NAMESPACE_VERSION 205 } // namespace 206