libstdc++-v3/src/globals_io.cc

   1 // Copyright (C) 2001, 2002, 2003 Free Software Foundation, Inc.
   2 //
   3 // This file is part of the GNU ISO C++ Library.  This library is free
   4 // software; you can redistribute it and/or modify it under the
   5 // terms of the GNU General Public License as published by the
   6 // Free Software Foundation; either version 2, or (at your option)
   7 // any later version.
   8
   9 // This library is distributed in the hope that it will be useful,
  10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 // GNU General Public License for more details.
  13
  14 // You should have received a copy of the GNU General Public License along
  15 // with this library; see the file COPYING.  If not, write to the Free
  16 // Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
  17 // USA.
  18
  19 // As a special exception, you may use this file as part of a free software
  20 // library without restriction.  Specifically, if other files instantiate
  21 // templates or use macros or inline functions from this file, or you compile
  22 // this file and link it with other files to produce an executable, this
  23 // file does not by itself cause the resulting executable to be covered by
  24 // the GNU General Public License.  This exception does not however
  25 // invalidate any other reasons why the executable file might be covered by
  26 // the GNU General Public License.
  27
  28 #include "bits/c++config.h"
  29 #include "bits/gthr.h"
  30 #include <fstream>
  31 #include <istream>
  32 #include <ostream>
  33 #include <ext/stdio_filebuf.h>
  34 #include <ext/stdio_sync_filebuf.h>
  35
  36 // On AIX, and perhaps other systems, library initialization order is
  37 // not guaranteed.  For example, the static initializers for the main
  38 // program might run before the static initializers for this library.
  39 // That means that we cannot rely on static initialization in the
  40 // library; there is no guarantee that things will get initialized in
  41 // time.  This file contains definitions of all global variables that
  42 // require initialization as arrays of characters.
  43
  44 // NB: asm directives can rename these non-exported, namespace
  45 // __gnu_cxx symbols into exported, namespace std symbols with the
  46 // appropriate symbol version name.
  47 // The rename syntax is
  48 //   asm (".symver currentname,oldname@@GLIBCXX_3.2")
  49 // In macro form:
  50 // _GLIBCXX_ASM_SYMVER(currentname, oldname, GLIBCXX_3.2)
  51
  52 namespace std
  53 {
  54   // Standard stream objects.
  55   // NB: Iff <iostream> is included, these definitions become wonky.
  56   typedef char fake_istream[sizeof(istream)]
  57   __attribute__ ((aligned(__alignof__(istream))));
  58   typedef char fake_ostream[sizeof(ostream)]
  59   __attribute__ ((aligned(__alignof__(ostream))));
  60   fake_istream cin;
  61   fake_ostream cout;
  62   fake_ostream cerr;
  63   fake_ostream clog;
  64
  65 #ifdef _GLIBCXX_USE_WCHAR_T
  66   typedef char fake_wistream[sizeof(wistream)]
  67   __attribute__ ((aligned(__alignof__(wistream))));
  68   typedef char fake_wostream[sizeof(wostream)]
  69   __attribute__ ((aligned(__alignof__(wostream))));
  70   fake_wistream wcin;
  71   fake_wostream wcout;
  72   fake_wostream wcerr;
  73   fake_wostream wclog;
  74 #endif
  75 } // namespace std
  76
  77 namespace __gnu_cxx
  78 {
  79   using namespace std;
  80
  81   // We use different stream buffer types depending on whether
  82   // ios_base::sync_with_stdio(false) has been called.
  83   typedef char fake_stdiobuf[sizeof(stdio_sync_filebuf<char>)]
  84   __attribute__ ((aligned(__alignof__(stdio_sync_filebuf<char>))));
  85   fake_stdiobuf buf_cout_sync;
  86   fake_stdiobuf buf_cin_sync;
  87   fake_stdiobuf buf_cerr_sync;
  88
  89   typedef char fake_filebuf[sizeof(stdio_filebuf<char>)]
  90   __attribute__ ((aligned(__alignof__(stdio_filebuf<char>))));
  91   fake_filebuf buf_cout;
  92   fake_filebuf buf_cin;
  93   fake_filebuf buf_cerr;
  94
  95 #ifdef _GLIBCXX_USE_WCHAR_T
  96   typedef char fake_wstdiobuf[sizeof(stdio_sync_filebuf<wchar_t>)]
  97   __attribute__ ((aligned(__alignof__(stdio_sync_filebuf<wchar_t>))));
  98   fake_wstdiobuf buf_wcout_sync;
  99   fake_wstdiobuf buf_wcin_sync;
 100   fake_wstdiobuf buf_wcerr_sync;
 101
 102   typedef char fake_wfilebuf[sizeof(stdio_filebuf<wchar_t>)]
 103   __attribute__ ((aligned(__alignof__(stdio_filebuf<wchar_t>))));
 104   fake_wfilebuf buf_wcout;
 105   fake_wfilebuf buf_wcin;
 106   fake_wfilebuf buf_wcerr;
 107 #endif
 108
 109   // Globals for once-only runtime initialization of mutex objects.  This
 110   // allows static initialization of these objects on systems that need a
 111   // function call to initialize a mutex.  For example, see stl_threads.h.
 112 #ifdef __GTHREAD_MUTEX_INIT
 113 #elif defined(__GTHREAD_MUTEX_INIT_FUNCTION)
 114   __gthread_once_t _GLIBCXX_once = __GTHREAD_ONCE_INIT;
 115   __gthread_mutex_t _GLIBCXX_mutex;
 116   __gthread_mutex_t *_GLIBCXX_mutex_address;
 117
 118   // Once-only initializer function for _GLIBCXX_mutex.
 119   void
 120   _GLIBCXX_mutex_init ()
 121   { __GTHREAD_MUTEX_INIT_FUNCTION (&_GLIBCXX_mutex); }
 122
 123   // Once-only initializer function for _GLIBCXX_mutex_address.
 124   void
 125   _GLIBCXX_mutex_address_init ()
 126   { __GTHREAD_MUTEX_INIT_FUNCTION (_GLIBCXX_mutex_address); }
 127 #endif
 128 } // namespace __gnu_cxx