xref: /openbsd-src/gnu/lib/libstdc++/libstdc++/src/ios.cc (revision c2fb321235c8dbfba0909bc43913400e90646ae7)
1 // Iostreams base classes -*- C++ -*-
2 
3 // Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002
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, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
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 <bits/atomicity.h>
40 #include <ext/stdio_filebuf.h>
41 #ifdef _GLIBCPP_HAVE_UNISTD_H
42 #include <unistd.h>
43 #endif
44 
45 namespace __gnu_cxx
46 {
47   // Extern declarations for global objects in src/globals.cc.
48   extern stdio_filebuf<char> buf_cout;
49   extern stdio_filebuf<char> buf_cin;
50   extern stdio_filebuf<char> buf_cerr;
51 
52 #if defined(_GLIBCPP_USE_WCHAR_T) || defined(_GLIBCPP_USE_TYPE_WCHAR_T)
53   extern stdio_filebuf<wchar_t> buf_wcout;
54   extern stdio_filebuf<wchar_t> buf_wcin;
55   extern stdio_filebuf<wchar_t> buf_wcerr;
56 #endif
57 } // namespace __gnu_cxx
58 
59 namespace std
60 {
61   using namespace __gnu_cxx;
62 
63   extern istream cin;
64   extern ostream cout;
65   extern ostream cerr;
66   extern ostream clog;
67 
68 #if defined(_GLIBCPP_USE_WCHAR_T) || defined(_GLIBCPP_USE_TYPE_WCHAR_T)
69   extern wistream wcin;
70   extern wostream wcout;
71   extern wostream wcerr;
72   extern wostream wclog;
73 #endif
74 
75   // Definitions for static const data members of __ios_flags.
76   const __ios_flags::__int_type __ios_flags::_S_boolalpha;
77   const __ios_flags::__int_type __ios_flags::_S_dec;
78   const __ios_flags::__int_type __ios_flags::_S_fixed;
79   const __ios_flags::__int_type __ios_flags::_S_hex;
80   const __ios_flags::__int_type __ios_flags::_S_internal;
81   const __ios_flags::__int_type __ios_flags::_S_left;
82   const __ios_flags::__int_type __ios_flags::_S_oct;
83   const __ios_flags::__int_type __ios_flags::_S_right;
84   const __ios_flags::__int_type __ios_flags::_S_scientific;
85   const __ios_flags::__int_type __ios_flags::_S_showbase;
86   const __ios_flags::__int_type __ios_flags::_S_showpoint;
87   const __ios_flags::__int_type __ios_flags::_S_showpos;
88   const __ios_flags::__int_type __ios_flags::_S_skipws;
89   const __ios_flags::__int_type __ios_flags::_S_unitbuf;
90   const __ios_flags::__int_type __ios_flags::_S_uppercase;
91   const __ios_flags::__int_type __ios_flags::_S_adjustfield;
92   const __ios_flags::__int_type __ios_flags::_S_basefield;
93   const __ios_flags::__int_type __ios_flags::_S_floatfield;
94 
95   const __ios_flags::__int_type __ios_flags::_S_badbit;
96   const __ios_flags::__int_type __ios_flags::_S_eofbit;
97   const __ios_flags::__int_type __ios_flags::_S_failbit;
98 
99   const __ios_flags::__int_type __ios_flags::_S_app;
100   const __ios_flags::__int_type __ios_flags::_S_ate;
101   const __ios_flags::__int_type __ios_flags::_S_bin;
102   const __ios_flags::__int_type __ios_flags::_S_in;
103   const __ios_flags::__int_type __ios_flags::_S_out;
104   const __ios_flags::__int_type __ios_flags::_S_trunc;
105 
106   // Definitions for static const members of ios_base.
107   const ios_base::fmtflags ios_base::boolalpha;
108   const ios_base::fmtflags ios_base::dec;
109   const ios_base::fmtflags ios_base::fixed;
110   const ios_base::fmtflags ios_base::hex;
111   const ios_base::fmtflags ios_base::internal;
112   const ios_base::fmtflags ios_base::left;
113   const ios_base::fmtflags ios_base::oct;
114   const ios_base::fmtflags ios_base::right;
115   const ios_base::fmtflags ios_base::scientific;
116   const ios_base::fmtflags ios_base::showbase;
117   const ios_base::fmtflags ios_base::showpoint;
118   const ios_base::fmtflags ios_base::showpos;
119   const ios_base::fmtflags ios_base::skipws;
120   const ios_base::fmtflags ios_base::unitbuf;
121   const ios_base::fmtflags ios_base::uppercase;
122   const ios_base::fmtflags ios_base::adjustfield;
123   const ios_base::fmtflags ios_base::basefield;
124   const ios_base::fmtflags ios_base::floatfield;
125 
126   const ios_base::iostate ios_base::badbit;
127   const ios_base::iostate ios_base::eofbit;
128   const ios_base::iostate ios_base::failbit;
129   const ios_base::iostate ios_base::goodbit;
130 
131   const ios_base::openmode ios_base::app;
132   const ios_base::openmode ios_base::ate;
133   const ios_base::openmode ios_base::binary;
134   const ios_base::openmode ios_base::in;
135   const ios_base::openmode ios_base::out;
136   const ios_base::openmode ios_base::trunc;
137 
138   const ios_base::seekdir ios_base::beg;
139   const ios_base::seekdir ios_base::cur;
140   const ios_base::seekdir ios_base::end;
141 
142   const int ios_base::_S_local_word_size;
143   int ios_base::Init::_S_ios_base_init = 0;
144   bool ios_base::Init::_S_synced_with_stdio = true;
145 
failure(const string & __str)146   ios_base::failure::failure(const string& __str) throw()
147   {
148     strncpy(_M_name, __str.c_str(), _M_bufsize);
149     _M_name[_M_bufsize - 1] = '\0';
150   }
151 
~failure()152   ios_base::failure::~failure() throw()
153   { }
154 
155   const char*
what() const156   ios_base::failure::what() const throw()
157   { return _M_name; }
158 
159   void
_S_ios_create(bool __sync)160   ios_base::Init::_S_ios_create(bool __sync)
161   {
162     size_t __out_size = __sync ? 0 : static_cast<size_t>(BUFSIZ);
163 #ifdef _GLIBCPP_HAVE_ISATTY
164     size_t __in_size =
165       (__sync || isatty (0)) ? 1 : static_cast<size_t>(BUFSIZ);
166 #else
167     size_t __in_size = 1;
168 #endif
169 
170     // NB: The file globals.cc creates the four standard files
171     // with NULL buffers. At this point, we swap out the dummy NULL
172     // [io]stream objects and buffers with the real deal.
173     new (&buf_cout) stdio_filebuf<char>(stdout, ios_base::out, __out_size);
174     new (&buf_cin) stdio_filebuf<char>(stdin, ios_base::in, __in_size);
175     new (&buf_cerr) stdio_filebuf<char>(stderr, ios_base::out, __out_size);
176 
177     new (&cout) ostream(&buf_cout);
178     new (&cin) istream(&buf_cin);
179     new (&cerr) ostream(&buf_cerr);
180     new (&clog) ostream(&buf_cerr);
181     cout.init(&buf_cout);
182     cin.init(&buf_cin);
183     cerr.init(&buf_cerr);
184     clog.init(&buf_cerr);
185     cin.tie(&cout);
186     cerr.flags(ios_base::unitbuf);
187 
188 #if defined(_GLIBCPP_USE_WCHAR_T) || defined(_GLIBCPP_USE_TYPE_WCHAR_T)
189     new (&buf_wcout) stdio_filebuf<wchar_t>(stdout, ios_base::out, __out_size);
190     new (&buf_wcin) stdio_filebuf<wchar_t>(stdin, ios_base::in, __in_size);
191     new (&buf_wcerr) stdio_filebuf<wchar_t>(stderr, ios_base::out, __out_size);
192     new (&wcout) wostream(&buf_wcout);
193     new (&wcin) wistream(&buf_wcin);
194     new (&wcerr) wostream(&buf_wcerr);
195     new (&wclog) wostream(&buf_wcerr);
196     wcout.init(&buf_wcout);
197     wcin.init(&buf_wcin);
198     wcerr.init(&buf_wcerr);
199     wclog.init(&buf_wcerr);
200     wcin.tie(&wcout);
201     wcerr.flags(ios_base::unitbuf);
202 #endif
203   }
204 
205   void
_S_ios_destroy()206   ios_base::Init::_S_ios_destroy()
207   {
208     // Explicitly call dtors to free any memory that is dynamically
209     // allocated by filebuf ctor or member functions, but don't
210     // deallocate all memory by calling operator delete.
211     buf_cout.~stdio_filebuf();
212     buf_cin.~stdio_filebuf();
213     buf_cerr.~stdio_filebuf();
214 
215 #if defined(_GLIBCPP_USE_WCHAR_T) || defined(_GLIBCPP_USE_TYPE_WCHAR_T)
216     buf_wcout.~stdio_filebuf();
217     buf_wcin.~stdio_filebuf();
218     buf_wcerr.~stdio_filebuf();
219 #endif
220   }
221 
Init()222   ios_base::Init::Init()
223   {
224     if (_S_ios_base_init == 0)
225       {
226 	// Standard streams default to synced with "C" operations.
227 	ios_base::Init::_S_synced_with_stdio = true;
228 	_S_ios_create(ios_base::Init::_S_synced_with_stdio);
229       }
230     ++_S_ios_base_init;
231   }
232 
~Init()233   ios_base::Init::~Init()
234   {
235     if (--_S_ios_base_init == 0)
236       _S_ios_destroy();
237   }
238 
239   // 27.4.2.5  ios_base storage functions
240   int
xalloc()241   ios_base::xalloc() throw()
242   {
243     // Implementation note: Initialize top to zero to ensure that
244     // initialization occurs before main() is started.
245     static _Atomic_word _S_top = 0;
246     return __exchange_and_add(&_S_top, 1) + 4;
247   }
248 
249   // 27.4.2.5  iword/pword storage
250   ios_base::_Words&
_M_grow_words(int ix)251   ios_base::_M_grow_words(int ix)
252   {
253     // Precondition: _M_word_size <= ix
254     int newsize = _S_local_word_size;
255     _Words* words = _M_local_word;
256     if (ix > _S_local_word_size - 1)
257       {
258 	if (ix < numeric_limits<int>::max())
259 	  {
260 	    newsize = ix + 1;
261 	    try
262 	      { words = new _Words[newsize]; }
263 	    catch (...)
264 	      {
265 		_M_streambuf_state |= badbit;
266 		if (_M_streambuf_state & _M_exception)
267 		  __throw_ios_failure("ios_base::_M_grow_words failure");
268 		return _M_word_zero;
269 	      }
270 	    for (int i = 0; i < _M_word_size; i++)
271 	      words[i] = _M_word[i];
272 	    if (_M_word && _M_word != _M_local_word)
273 	      {
274 		delete [] _M_word;
275 		_M_word = 0;
276 	      }
277 	  }
278 	else
279 	  {
280 	    _M_streambuf_state |= badbit;
281 	    if (_M_streambuf_state & _M_exception)
282 	      __throw_ios_failure("ios_base::_M_grow_words failure");
283 	    return _M_word_zero;
284 	  }
285       }
286     _M_word = words;
287     _M_word_size = newsize;
288     return _M_word[ix];
289   }
290 
291   // Called only by basic_ios<>::init.
292   void
_M_init()293   ios_base::_M_init()
294   {
295     // NB: May be called more than once
296     _M_precision = 6;
297     _M_width = 0;
298     _M_flags = skipws | dec;
299     _M_ios_locale = locale();
300   }
301 
302   // 27.4.2.3  ios_base locale functions
303   locale
imbue(const locale & __loc)304   ios_base::imbue(const locale& __loc)
305   {
306     locale __old = _M_ios_locale;
307     _M_ios_locale = __loc;
308     _M_call_callbacks(imbue_event);
309     return __old;
310   }
311 
ios_base()312   ios_base::ios_base() : _M_callbacks(0), _M_word_size(_S_local_word_size),
313 			 _M_word(_M_local_word)
314   {
315     // Do nothing: basic_ios::init() does it.
316     // NB: _M_callbacks and _M_word must be zero for non-initialized
317     // ios_base to go through ~ios_base gracefully.
318   }
319 
320   // 27.4.2.7  ios_base constructors/destructors
~ios_base()321   ios_base::~ios_base()
322   {
323     _M_call_callbacks(erase_event);
324     _M_dispose_callbacks();
325     if (_M_word != _M_local_word)
326       {
327 	delete [] _M_word;
328 	_M_word = 0;
329       }
330   }
331 
332   void
register_callback(event_callback __fn,int __index)333   ios_base::register_callback(event_callback __fn, int __index)
334   { _M_callbacks = new _Callback_list(__fn, __index, _M_callbacks); }
335 
336   void
_M_call_callbacks(event __e)337   ios_base::_M_call_callbacks(event __e) throw()
338   {
339     _Callback_list* __p = _M_callbacks;
340     while (__p)
341       {
342 	try
343 	  { (*__p->_M_fn) (__e, *this, __p->_M_index); }
344 	catch (...)
345 	  { }
346 	__p = __p->_M_next;
347       }
348   }
349 
350   void
_M_dispose_callbacks(void)351   ios_base::_M_dispose_callbacks(void)
352   {
353     _Callback_list* __p = _M_callbacks;
354     while (__p && __p->_M_remove_reference() == 0)
355       {
356 	_Callback_list* __next = __p->_M_next;
357 	delete __p;
358 	__p = __next;
359       }
360     _M_callbacks = 0;
361   }
362 
363   bool
sync_with_stdio(bool __sync)364   ios_base::sync_with_stdio(bool __sync)
365   {
366 #ifdef _GLIBCPP_RESOLVE_LIB_DEFECTS
367     // 49.  Underspecification of ios_base::sync_with_stdio
368     bool __ret = ios_base::Init::_S_synced_with_stdio;
369 #endif
370 
371     // Turn off sync with C FILE* for cin, cout, cerr, clog iff
372     // currently synchronized.
373     if (!__sync && __ret)
374       {
375 	ios_base::Init::_S_synced_with_stdio = false;
376 	ios_base::Init::_S_ios_destroy();
377 	ios_base::Init::_S_ios_create(ios_base::Init::_S_synced_with_stdio);
378       }
379     return __ret;
380   }
381 }  // namespace std
382