ios_init.cc revision 146897
1// Iostreams base classes -*- C++ -*- 2 3// Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004 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#include <ext/stdio_sync_filebuf.h> 42 43namespace __gnu_internal 44{ 45 using namespace __gnu_cxx; 46 47 // Extern declarations for global objects in src/globals.cc. 48 extern stdio_sync_filebuf<char> buf_cout_sync; 49 extern stdio_sync_filebuf<char> buf_cin_sync; 50 extern stdio_sync_filebuf<char> buf_cerr_sync; 51 52 extern stdio_filebuf<char> buf_cout; 53 extern stdio_filebuf<char> buf_cin; 54 extern stdio_filebuf<char> buf_cerr; 55 56#ifdef _GLIBCXX_USE_WCHAR_T 57 extern stdio_sync_filebuf<wchar_t> buf_wcout_sync; 58 extern stdio_sync_filebuf<wchar_t> buf_wcin_sync; 59 extern stdio_sync_filebuf<wchar_t> buf_wcerr_sync; 60 61 extern stdio_filebuf<wchar_t> buf_wcout; 62 extern stdio_filebuf<wchar_t> buf_wcin; 63 extern stdio_filebuf<wchar_t> buf_wcerr; 64#endif 65} // namespace __gnu_internal 66 67namespace std 68{ 69 using namespace __gnu_internal; 70 71 extern istream cin; 72 extern ostream cout; 73 extern ostream cerr; 74 extern ostream clog; 75 76#ifdef _GLIBCXX_USE_WCHAR_T 77 extern wistream wcin; 78 extern wostream wcout; 79 extern wostream wcerr; 80 extern wostream wclog; 81#endif 82 83 ios_base::Init::Init() 84 { 85 if (__gnu_cxx::__exchange_and_add(&_S_refcount, 1) == 0) 86 { 87 // Standard streams default to synced with "C" operations. 88 _S_synced_with_stdio = true; 89 90 new (&buf_cout_sync) stdio_sync_filebuf<char>(stdout); 91 new (&buf_cin_sync) stdio_sync_filebuf<char>(stdin); 92 new (&buf_cerr_sync) stdio_sync_filebuf<char>(stderr); 93 94 // The standard streams are constructed once only and never 95 // destroyed. 96 new (&cout) ostream(&buf_cout_sync); 97 new (&cin) istream(&buf_cin_sync); 98 new (&cerr) ostream(&buf_cerr_sync); 99 new (&clog) ostream(&buf_cerr_sync); 100 cin.tie(&cout); 101 cerr.flags(ios_base::unitbuf); 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.flags(ios_base::unitbuf); 114#endif 115 116 // NB: Have to set refcount above one, so that standard 117 // streams are not re-initialized with uses of ios_base::Init 118 // besides <iostream> static object, ie just using <ios> with 119 // ios_base::Init objects. 120 __gnu_cxx::__atomic_add(&_S_refcount, 1); 121 } 122 } 123 124 ios_base::Init::~Init() 125 { 126 if (__gnu_cxx::__exchange_and_add(&_S_refcount, -1) == 2) 127 { 128 // Catch any exceptions thrown by basic_ostream::flush() 129 try 130 { 131 // Flush standard output streams as required by 27.4.2.1.6 132 cout.flush(); 133 cerr.flush(); 134 clog.flush(); 135 136#ifdef _GLIBCXX_USE_WCHAR_T 137 wcout.flush(); 138 wcerr.flush(); 139 wclog.flush(); 140#endif 141 } 142 catch (...) 143 { } 144 } 145 } 146 147 bool 148 ios_base::sync_with_stdio(bool __sync) 149 { 150 // _GLIBCXX_RESOLVE_LIB_DEFECTS 151 // 49. Underspecification of ios_base::sync_with_stdio 152 bool __ret = ios_base::Init::_S_synced_with_stdio; 153 154 // Turn off sync with C FILE* for cin, cout, cerr, clog iff 155 // currently synchronized. 156 if (!__sync && __ret) 157 { 158 // Make sure the standard streams are constructed. 159 ios_base::Init __init; 160 161 ios_base::Init::_S_synced_with_stdio = __sync; 162 163 // Explicitly call dtors to free any memory that is 164 // dynamically allocated by filebuf ctor or member functions, 165 // but don't deallocate all memory by calling operator delete. 166 buf_cout_sync.~stdio_sync_filebuf<char>(); 167 buf_cin_sync.~stdio_sync_filebuf<char>(); 168 buf_cerr_sync.~stdio_sync_filebuf<char>(); 169 170#ifdef _GLIBCXX_USE_WCHAR_T 171 buf_wcout_sync.~stdio_sync_filebuf<wchar_t>(); 172 buf_wcin_sync.~stdio_sync_filebuf<wchar_t>(); 173 buf_wcerr_sync.~stdio_sync_filebuf<wchar_t>(); 174#endif 175 176 // Create stream buffers for the standard streams and use 177 // those buffers without destroying and recreating the 178 // streams. 179 new (&buf_cout) stdio_filebuf<char>(stdout, ios_base::out); 180 new (&buf_cin) stdio_filebuf<char>(stdin, ios_base::in); 181 new (&buf_cerr) stdio_filebuf<char>(stderr, ios_base::out); 182 cout.rdbuf(&buf_cout); 183 cin.rdbuf(&buf_cin); 184 cerr.rdbuf(&buf_cerr); 185 clog.rdbuf(&buf_cerr); 186 187#ifdef _GLIBCXX_USE_WCHAR_T 188 new (&buf_wcout) stdio_filebuf<wchar_t>(stdout, ios_base::out); 189 new (&buf_wcin) stdio_filebuf<wchar_t>(stdin, ios_base::in); 190 new (&buf_wcerr) stdio_filebuf<wchar_t>(stderr, ios_base::out); 191 wcout.rdbuf(&buf_wcout); 192 wcin.rdbuf(&buf_wcin); 193 wcerr.rdbuf(&buf_wcerr); 194 wclog.rdbuf(&buf_wcerr); 195#endif 196 } 197 return __ret; 198 } 199} // namespace std 200