1 // Iostreams base classes -*- C++ -*- 2 3 // Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006 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, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, 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 <ext/stdio_filebuf.h> 40 #include <ext/stdio_sync_filebuf.h> 41 42 namespace __gnu_internal _GLIBCXX_VISIBILITY(hidden) 43 { 44 using namespace __gnu_cxx; 45 46 // Extern declarations for global objects in src/globals.cc. 47 extern stdio_sync_filebuf<char> buf_cout_sync; 48 extern stdio_sync_filebuf<char> buf_cin_sync; 49 extern stdio_sync_filebuf<char> buf_cerr_sync; 50 51 extern stdio_filebuf<char> buf_cout; 52 extern stdio_filebuf<char> buf_cin; 53 extern stdio_filebuf<char> buf_cerr; 54 55 #ifdef _GLIBCXX_USE_WCHAR_T 56 extern stdio_sync_filebuf<wchar_t> buf_wcout_sync; 57 extern stdio_sync_filebuf<wchar_t> buf_wcin_sync; 58 extern stdio_sync_filebuf<wchar_t> buf_wcerr_sync; 59 60 extern stdio_filebuf<wchar_t> buf_wcout; 61 extern stdio_filebuf<wchar_t> buf_wcin; 62 extern stdio_filebuf<wchar_t> buf_wcerr; 63 #endif 64 } // namespace __gnu_internal 65 66 _GLIBCXX_BEGIN_NAMESPACE(std) 67 68 using namespace __gnu_internal; 69 70 extern istream cin; 71 extern ostream cout; 72 extern ostream cerr; 73 extern ostream clog; 74 75 #ifdef _GLIBCXX_USE_WCHAR_T 76 extern wistream wcin; 77 extern wostream wcout; 78 extern wostream wcerr; 79 extern wostream wclog; 80 #endif 81 Init()82 ios_base::Init::Init() 83 { 84 if (__gnu_cxx::__exchange_and_add_dispatch(&_S_refcount, 1) == 0) 85 { 86 // Standard streams default to synced with "C" operations. 87 _S_synced_with_stdio = true; 88 89 new (&buf_cout_sync) stdio_sync_filebuf<char>(stdout); 90 new (&buf_cin_sync) stdio_sync_filebuf<char>(stdin); 91 new (&buf_cerr_sync) stdio_sync_filebuf<char>(stderr); 92 93 // The standard streams are constructed once only and never 94 // destroyed. 95 new (&cout) ostream(&buf_cout_sync); 96 new (&cin) istream(&buf_cin_sync); 97 new (&cerr) ostream(&buf_cerr_sync); 98 new (&clog) ostream(&buf_cerr_sync); 99 cin.tie(&cout); 100 cerr.flags(ios_base::unitbuf); 101 // _GLIBCXX_RESOLVE_LIB_DEFECTS 102 // 455. cerr::tie() and wcerr::tie() are overspecified. 103 cerr.tie(&cout); 104 105 #ifdef _GLIBCXX_USE_WCHAR_T 106 new (&buf_wcout_sync) stdio_sync_filebuf<wchar_t>(stdout); 107 new (&buf_wcin_sync) stdio_sync_filebuf<wchar_t>(stdin); 108 new (&buf_wcerr_sync) stdio_sync_filebuf<wchar_t>(stderr); 109 110 new (&wcout) wostream(&buf_wcout_sync); 111 new (&wcin) wistream(&buf_wcin_sync); 112 new (&wcerr) wostream(&buf_wcerr_sync); 113 new (&wclog) wostream(&buf_wcerr_sync); 114 wcin.tie(&wcout); 115 wcerr.flags(ios_base::unitbuf); 116 wcerr.tie(&wcout); 117 #endif 118 119 // NB: Have to set refcount above one, so that standard 120 // streams are not re-initialized with uses of ios_base::Init 121 // besides <iostream> static object, ie just using <ios> with 122 // ios_base::Init objects. 123 __gnu_cxx::__atomic_add_dispatch(&_S_refcount, 1); 124 } 125 } 126 ~Init()127 ios_base::Init::~Init() 128 { 129 if (__gnu_cxx::__exchange_and_add_dispatch(&_S_refcount, -1) == 2) 130 { 131 // Catch any exceptions thrown by basic_ostream::flush() 132 try 133 { 134 // Flush standard output streams as required by 27.4.2.1.6 135 cout.flush(); 136 cerr.flush(); 137 clog.flush(); 138 139 #ifdef _GLIBCXX_USE_WCHAR_T 140 wcout.flush(); 141 wcerr.flush(); 142 wclog.flush(); 143 #endif 144 } 145 catch (...) 146 { } 147 } 148 } 149 150 bool sync_with_stdio(bool __sync)151 ios_base::sync_with_stdio(bool __sync) 152 { 153 // _GLIBCXX_RESOLVE_LIB_DEFECTS 154 // 49. Underspecification of ios_base::sync_with_stdio 155 bool __ret = ios_base::Init::_S_synced_with_stdio; 156 157 // Turn off sync with C FILE* for cin, cout, cerr, clog iff 158 // currently synchronized. 159 if (!__sync && __ret) 160 { 161 // Make sure the standard streams are constructed. 162 ios_base::Init __init; 163 164 ios_base::Init::_S_synced_with_stdio = __sync; 165 166 // Explicitly call dtors to free any memory that is 167 // dynamically allocated by filebuf ctor or member functions, 168 // but don't deallocate all memory by calling operator delete. 169 buf_cout_sync.~stdio_sync_filebuf<char>(); 170 buf_cin_sync.~stdio_sync_filebuf<char>(); 171 buf_cerr_sync.~stdio_sync_filebuf<char>(); 172 173 #ifdef _GLIBCXX_USE_WCHAR_T 174 buf_wcout_sync.~stdio_sync_filebuf<wchar_t>(); 175 buf_wcin_sync.~stdio_sync_filebuf<wchar_t>(); 176 buf_wcerr_sync.~stdio_sync_filebuf<wchar_t>(); 177 #endif 178 179 // Create stream buffers for the standard streams and use 180 // those buffers without destroying and recreating the 181 // streams. 182 new (&buf_cout) stdio_filebuf<char>(stdout, ios_base::out); 183 new (&buf_cin) stdio_filebuf<char>(stdin, ios_base::in); 184 new (&buf_cerr) stdio_filebuf<char>(stderr, ios_base::out); 185 cout.rdbuf(&buf_cout); 186 cin.rdbuf(&buf_cin); 187 cerr.rdbuf(&buf_cerr); 188 clog.rdbuf(&buf_cerr); 189 190 #ifdef _GLIBCXX_USE_WCHAR_T 191 new (&buf_wcout) stdio_filebuf<wchar_t>(stdout, ios_base::out); 192 new (&buf_wcin) stdio_filebuf<wchar_t>(stdin, ios_base::in); 193 new (&buf_wcerr) stdio_filebuf<wchar_t>(stderr, ios_base::out); 194 wcout.rdbuf(&buf_wcout); 195 wcin.rdbuf(&buf_wcin); 196 wcerr.rdbuf(&buf_wcerr); 197 wclog.rdbuf(&buf_wcerr); 198 #endif 199 } 200 return __ret; 201 } 202 203 _GLIBCXX_END_NAMESPACE 204