contrib/gcc-8.0/libstdc++-v3/src/c++98/ios_init.cc

   1 // Iostreams base classes -*- C++ -*-
   2
   3 // Copyright (C) 1997-2018 Free Software Foundation, Inc.
   4 //
   5 // This file is part of the GNU ISO C++ Library.  This library is free
   6 // software; you can redistribute it and/or modify it under the
   7 // terms of the GNU General Public License as published by the
   8 // Free Software Foundation; either version 3, or (at your option)
   9 // any later version.
  10
  11 // This library is distributed in the hope that it will be useful,
  12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 // GNU General Public License for more details.
  15
  16 // Under Section 7 of GPL version 3, you are granted additional
  17 // permissions described in the GCC Runtime Library Exception, version
  18 // 3.1, as published by the Free Software Foundation.
  19
  20 // You should have received a copy of the GNU General Public License and
  21 // a copy of the GCC Runtime Library Exception along with this program;
  22 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  23 // <http://www.gnu.org/licenses/>.
  24
  25 //
  26 // ISO C++ 14882: 27.4  Iostreams base classes
  27 //
  28
  29 #include <ios>
  30 #include <ostream>
  31 #include <istream>
  32 #include <fstream>
  33 #include <ext/stdio_filebuf.h>
  34 #include <ext/stdio_sync_filebuf.h>
  35
  36 namespace __gnu_internal _GLIBCXX_VISIBILITY(hidden)
  37 {
  38   using namespace __gnu_cxx;
  39
  40   // Extern declarations for global objects in src/c++98/globals.cc.
  41   extern stdio_sync_filebuf<char> buf_cout_sync;
  42   extern stdio_sync_filebuf<char> buf_cin_sync;
  43   extern stdio_sync_filebuf<char> buf_cerr_sync;
  44
  45   extern stdio_filebuf<char> buf_cout;
  46   extern stdio_filebuf<char> buf_cin;
  47   extern stdio_filebuf<char> buf_cerr;
  48
  49 #ifdef _GLIBCXX_USE_WCHAR_T
  50   extern stdio_sync_filebuf<wchar_t> buf_wcout_sync;
  51   extern stdio_sync_filebuf<wchar_t> buf_wcin_sync;
  52   extern stdio_sync_filebuf<wchar_t> buf_wcerr_sync;
  53
  54   extern stdio_filebuf<wchar_t> buf_wcout;
  55   extern stdio_filebuf<wchar_t> buf_wcin;
  56   extern stdio_filebuf<wchar_t> buf_wcerr;
  57 #endif
  58 } // namespace __gnu_internal
  59
  60 namespace std _GLIBCXX_VISIBILITY(default)
  61 {
  62 _GLIBCXX_BEGIN_NAMESPACE_VERSION
  63
  64   using namespace __gnu_internal;
  65
  66   extern istream cin;
  67   extern ostream cout;
  68   extern ostream cerr;
  69   extern ostream clog;
  70
  71 #ifdef _GLIBCXX_USE_WCHAR_T
  72   extern wistream wcin;
  73   extern wostream wcout;
  74   extern wostream wcerr;
  75   extern wostream wclog;
  76 #endif
  77
  78   ios_base::Init::Init()
  79   {
  80     if (__gnu_cxx::__exchange_and_add_dispatch(&_S_refcount, 1) == 0)
  81       {
  82         // Standard streams default to synced with "C" operations.
  83         _S_synced_with_stdio = true;
  84
  85         new (&buf_cout_sync) stdio_sync_filebuf<char>(stdout);
  86         new (&buf_cin_sync) stdio_sync_filebuf<char>(stdin);
  87         new (&buf_cerr_sync) stdio_sync_filebuf<char>(stderr);
  88
  89         // The standard streams are constructed once only and never
  90         // destroyed.
  91         new (&cout) ostream(&buf_cout_sync);
  92         new (&cin) istream(&buf_cin_sync);
  93         new (&cerr) ostream(&buf_cerr_sync);
  94         new (&clog) ostream(&buf_cerr_sync);
  95         cin.tie(&cout);
  96         cerr.setf(ios_base::unitbuf);
  97         // _GLIBCXX_RESOLVE_LIB_DEFECTS
  98         // 455. cerr::tie() and wcerr::tie() are overspecified.
  99         cerr.tie(&cout);
 100
 101 #ifdef _GLIBCXX_USE_WCHAR_T
 102         new (&buf_wcout_sync) stdio_sync_filebuf<wchar_t>(stdout);
 103         new (&buf_wcin_sync) stdio_sync_filebuf<wchar_t>(stdin);
 104         new (&buf_wcerr_sync) stdio_sync_filebuf<wchar_t>(stderr);
 105
 106         new (&wcout) wostream(&buf_wcout_sync);
 107         new (&wcin) wistream(&buf_wcin_sync);
 108         new (&wcerr) wostream(&buf_wcerr_sync);
 109         new (&wclog) wostream(&buf_wcerr_sync);
 110         wcin.tie(&wcout);
 111         wcerr.setf(ios_base::unitbuf);
 112         wcerr.tie(&wcout);
 113 #endif
 114
 115         // NB: Have to set refcount above one, so that standard
 116         // streams are not re-initialized with uses of ios_base::Init
 117         // besides <iostream> static object, ie just using <ios> with
 118         // ios_base::Init objects.
 119         __gnu_cxx::__atomic_add_dispatch(&_S_refcount, 1);
 120       }
 121   }
 122
 123   ios_base::Init::~Init()
 124   {
 125     // Be race-detector-friendly.  For more info see bits/c++config.
 126     _GLIBCXX_SYNCHRONIZATION_HAPPENS_BEFORE(&_S_refcount);
 127     if (__gnu_cxx::__exchange_and_add_dispatch(&_S_refcount, -1) == 2)
 128       {
 129         _GLIBCXX_SYNCHRONIZATION_HAPPENS_AFTER(&_S_refcount);
 130         // Catch any exceptions thrown by basic_ostream::flush()
 131         __try
 132           {
 133             // Flush standard output streams as required by 27.4.2.1.6
 134             cout.flush();
 135             cerr.flush();
 136             clog.flush();
 137
 138 #ifdef _GLIBCXX_USE_WCHAR_T
 139             wcout.flush();
 140             wcerr.flush();
 141             wclog.flush();
 142 #endif
 143           }
 144         __catch(...)
 145           { }
 146       }
 147   }
 148
 149   bool
 150   ios_base::sync_with_stdio(bool __sync)
 151   {
 152     // _GLIBCXX_RESOLVE_LIB_DEFECTS
 153     // 49.  Underspecification of ios_base::sync_with_stdio
 154     bool __ret = ios_base::Init::_S_synced_with_stdio;
 155
 156     // Turn off sync with C FILE* for cin, cout, cerr, clog iff
 157     // currently synchronized.
 158     if (!__sync && __ret)
 159       {
 160         // Make sure the standard streams are constructed.
 161         ios_base::Init __init;
 162
 163         ios_base::Init::_S_synced_with_stdio = __sync;
 164
 165         // Explicitly call dtors to free any memory that is
 166         // dynamically allocated by filebuf ctor or member functions,
 167         // but don't deallocate all memory by calling operator delete.
 168         buf_cout_sync.~stdio_sync_filebuf<char>();
 169         buf_cin_sync.~stdio_sync_filebuf<char>();
 170         buf_cerr_sync.~stdio_sync_filebuf<char>();
 171
 172 #ifdef _GLIBCXX_USE_WCHAR_T
 173         buf_wcout_sync.~stdio_sync_filebuf<wchar_t>();
 174         buf_wcin_sync.~stdio_sync_filebuf<wchar_t>();
 175         buf_wcerr_sync.~stdio_sync_filebuf<wchar_t>();
 176 #endif
 177
 178         // Create stream buffers for the standard streams and use
 179         // those buffers without destroying and recreating the
 180         // streams.
 181         new (&buf_cout) stdio_filebuf<char>(stdout, ios_base::out);
 182         new (&buf_cin) stdio_filebuf<char>(stdin, ios_base::in);
 183         new (&buf_cerr) stdio_filebuf<char>(stderr, ios_base::out);
 184         cout.rdbuf(&buf_cout);
 185         cin.rdbuf(&buf_cin);
 186         cerr.rdbuf(&buf_cerr);
 187         clog.rdbuf(&buf_cerr);
 188
 189 #ifdef _GLIBCXX_USE_WCHAR_T
 190         new (&buf_wcout) stdio_filebuf<wchar_t>(stdout, ios_base::out);
 191         new (&buf_wcin) stdio_filebuf<wchar_t>(stdin, ios_base::in);
 192         new (&buf_wcerr) stdio_filebuf<wchar_t>(stderr, ios_base::out);
 193         wcout.rdbuf(&buf_wcout);
 194         wcin.rdbuf(&buf_wcin);
 195         wcerr.rdbuf(&buf_wcerr);
 196         wclog.rdbuf(&buf_wcerr);
 197 #endif
 198       }
 199     return __ret;
 200   }
 201
 202 _GLIBCXX_END_NAMESPACE_VERSION
 203 } // namespace