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
42namespace __gnu_internal _GLIBCXX_VISIBILITY(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
204