libstdc++-v3/src/ios_init.cc

   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_ATTR(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
  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
 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
 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