globals_io.cc revision 132720 
1// Copyright (C) 2001, 2002, 2003, 2004 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
52namespace 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
77namespace __gnu_internal
78{
79  using namespace std;
80  using namespace __gnu_cxx;
81
82  // We use different stream buffer types depending on whether
83  // ios_base::sync_with_stdio(false) has been called.
84  typedef char fake_stdiobuf[sizeof(stdio_sync_filebuf<char>)]
85  __attribute__ ((aligned(__alignof__(stdio_sync_filebuf<char>))));
86  fake_stdiobuf buf_cout_sync;
87  fake_stdiobuf buf_cin_sync;
88  fake_stdiobuf buf_cerr_sync;
89
90  typedef char fake_filebuf[sizeof(stdio_filebuf<char>)]
91  __attribute__ ((aligned(__alignof__(stdio_filebuf<char>))));
92  fake_filebuf buf_cout;
93  fake_filebuf buf_cin;
94  fake_filebuf buf_cerr;
95
96#ifdef _GLIBCXX_USE_WCHAR_T
97  typedef char fake_wstdiobuf[sizeof(stdio_sync_filebuf<wchar_t>)]
98  __attribute__ ((aligned(__alignof__(stdio_sync_filebuf<wchar_t>))));
99  fake_wstdiobuf buf_wcout_sync;
100  fake_wstdiobuf buf_wcin_sync;
101  fake_wstdiobuf buf_wcerr_sync;
102
103  typedef char fake_wfilebuf[sizeof(stdio_filebuf<wchar_t>)]
104  __attribute__ ((aligned(__alignof__(stdio_filebuf<wchar_t>))));
105  fake_wfilebuf buf_wcout;
106  fake_wfilebuf buf_wcin;
107  fake_wfilebuf buf_wcerr;
108#endif
109
110  // Globals for once-only runtime initialization of mutex objects.  This
111  // allows static initialization of these objects on systems that need a
112  // function call to initialize a mutex.  For example, see stl_threads.h.
113#ifdef __GTHREAD_MUTEX_INIT
114#elif defined(__GTHREAD_MUTEX_INIT_FUNCTION)
115  __gthread_once_t _GLIBCXX_once = __GTHREAD_ONCE_INIT;
116  __gthread_mutex_t _GLIBCXX_mutex;
117  __gthread_mutex_t *_GLIBCXX_mutex_address;
118
119  // Once-only initializer function for _GLIBCXX_mutex.
120  void
121  _GLIBCXX_mutex_init ()
122  { __GTHREAD_MUTEX_INIT_FUNCTION (&_GLIBCXX_mutex); }
123
124  // Once-only initializer function for _GLIBCXX_mutex_address.
125  void
126  _GLIBCXX_mutex_address_init ()
127  { __GTHREAD_MUTEX_INIT_FUNCTION (_GLIBCXX_mutex_address); }
128#endif
129} // namespace __gnu_internal
130