xref: /freebsd-12.1/contrib/libstdc++/src/ios.cc (revision 9dbbb282)
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 
42 namespace __gnu_cxx
43 {
44   // Extern declarations for global objects in src/globals.cc.
45   extern stdio_filebuf<char> buf_cout;
46   extern stdio_filebuf<char> buf_cin;
47   extern stdio_filebuf<char> buf_cerr;
48 
49 #ifdef _GLIBCPP_USE_WCHAR_T
50   extern stdio_filebuf<wchar_t> buf_wcout;
51   extern stdio_filebuf<wchar_t> buf_wcin;
52   extern stdio_filebuf<wchar_t> buf_wcerr;
53 #endif
54 } // namespace __gnu_cxx
55 
56 namespace std
57 {
58   using namespace __gnu_cxx;
59 
60   extern istream cin;
61   extern ostream cout;
62   extern ostream cerr;
63   extern ostream clog;
64 
65 #ifdef _GLIBCPP_USE_WCHAR_T
66   extern wistream wcin;
67   extern wostream wcout;
68   extern wostream wcerr;
69   extern wostream wclog;
70 #endif
71 
72   // Definitions for static const data members of __ios_flags.
73   const __ios_flags::__int_type __ios_flags::_S_boolalpha;
74   const __ios_flags::__int_type __ios_flags::_S_dec;
75   const __ios_flags::__int_type __ios_flags::_S_fixed;
76   const __ios_flags::__int_type __ios_flags::_S_hex;
77   const __ios_flags::__int_type __ios_flags::_S_internal;
78   const __ios_flags::__int_type __ios_flags::_S_left;
79   const __ios_flags::__int_type __ios_flags::_S_oct;
80   const __ios_flags::__int_type __ios_flags::_S_right;
81   const __ios_flags::__int_type __ios_flags::_S_scientific;
82   const __ios_flags::__int_type __ios_flags::_S_showbase;
83   const __ios_flags::__int_type __ios_flags::_S_showpoint;
84   const __ios_flags::__int_type __ios_flags::_S_showpos;
85   const __ios_flags::__int_type __ios_flags::_S_skipws;
86   const __ios_flags::__int_type __ios_flags::_S_unitbuf;
87   const __ios_flags::__int_type __ios_flags::_S_uppercase;
88   const __ios_flags::__int_type __ios_flags::_S_adjustfield;
89   const __ios_flags::__int_type __ios_flags::_S_basefield;
90   const __ios_flags::__int_type __ios_flags::_S_floatfield;
91 
92   const __ios_flags::__int_type __ios_flags::_S_badbit;
93   const __ios_flags::__int_type __ios_flags::_S_eofbit;
94   const __ios_flags::__int_type __ios_flags::_S_failbit;
95 
96   const __ios_flags::__int_type __ios_flags::_S_app;
97   const __ios_flags::__int_type __ios_flags::_S_ate;
98   const __ios_flags::__int_type __ios_flags::_S_bin;
99   const __ios_flags::__int_type __ios_flags::_S_in;
100   const __ios_flags::__int_type __ios_flags::_S_out;
101   const __ios_flags::__int_type __ios_flags::_S_trunc;
102 
103   // Definitions for static const members of ios_base.
104   const ios_base::fmtflags ios_base::boolalpha;
105   const ios_base::fmtflags ios_base::dec;
106   const ios_base::fmtflags ios_base::fixed;
107   const ios_base::fmtflags ios_base::hex;
108   const ios_base::fmtflags ios_base::internal;
109   const ios_base::fmtflags ios_base::left;
110   const ios_base::fmtflags ios_base::oct;
111   const ios_base::fmtflags ios_base::right;
112   const ios_base::fmtflags ios_base::scientific;
113   const ios_base::fmtflags ios_base::showbase;
114   const ios_base::fmtflags ios_base::showpoint;
115   const ios_base::fmtflags ios_base::showpos;
116   const ios_base::fmtflags ios_base::skipws;
117   const ios_base::fmtflags ios_base::unitbuf;
118   const ios_base::fmtflags ios_base::uppercase;
119   const ios_base::fmtflags ios_base::adjustfield;
120   const ios_base::fmtflags ios_base::basefield;
121   const ios_base::fmtflags ios_base::floatfield;
122 
123   const ios_base::iostate ios_base::badbit;
124   const ios_base::iostate ios_base::eofbit;
125   const ios_base::iostate ios_base::failbit;
126   const ios_base::iostate ios_base::goodbit;
127 
128   const ios_base::openmode ios_base::app;
129   const ios_base::openmode ios_base::ate;
130   const ios_base::openmode ios_base::binary;
131   const ios_base::openmode ios_base::in;
132   const ios_base::openmode ios_base::out;
133   const ios_base::openmode ios_base::trunc;
134 
135   const ios_base::seekdir ios_base::beg;
136   const ios_base::seekdir ios_base::cur;
137   const ios_base::seekdir ios_base::end;
138 
139   const int ios_base::_S_local_word_size;
140   int ios_base::Init::_S_ios_base_init = 0;
141   bool ios_base::Init::_S_synced_with_stdio = true;
142 
143   ios_base::failure::failure(const string& __str) throw()
144   {
145     strncpy(_M_name, __str.c_str(), _M_bufsize);
146     _M_name[_M_bufsize - 1] = '\0';
147   }
148 
149   ios_base::failure::~failure() throw()
150   { }
151 
152   const char*
153   ios_base::failure::what() const throw()
154   { return _M_name; }
155 
156   void
157   ios_base::Init::_S_ios_create(bool __sync)
158   {
159     int __out_size = __sync ? 0 : static_cast<int>(BUFSIZ);
160     int __in_size = __sync ? 1 : static_cast<int>(BUFSIZ);
161 
162     // NB: The file globals.cc creates the four standard files
163     // with NULL buffers. At this point, we swap out the dummy NULL
164     // [io]stream objects and buffers with the real deal.
165     new (&buf_cout) stdio_filebuf<char>(stdout, ios_base::out, __out_size);
166     new (&buf_cin) stdio_filebuf<char>(stdin, ios_base::in, __in_size);
167     new (&buf_cerr) stdio_filebuf<char>(stderr, ios_base::out, __out_size);
168     new (&cout) ostream(&buf_cout);
169     new (&cin) istream(&buf_cin);
170     new (&cerr) ostream(&buf_cerr);
171     new (&clog) ostream(&buf_cerr);
172     cin.tie(&cout);
173     cerr.flags(ios_base::unitbuf);
174 
175 #ifdef _GLIBCPP_USE_WCHAR_T
176     new (&buf_wcout) stdio_filebuf<wchar_t>(stdout, ios_base::out, __out_size);
177     new (&buf_wcin) stdio_filebuf<wchar_t>(stdin, ios_base::in, __in_size);
178     new (&buf_wcerr) stdio_filebuf<wchar_t>(stderr, ios_base::out, __out_size);
179     new (&wcout) wostream(&buf_wcout);
180     new (&wcin) wistream(&buf_wcin);
181     new (&wcerr) wostream(&buf_wcerr);
182     new (&wclog) wostream(&buf_wcerr);
183     wcin.tie(&wcout);
184     wcerr.flags(ios_base::unitbuf);
185 #endif
186   }
187 
188   void
189   ios_base::Init::_S_ios_destroy()
190   {
191     // Explicitly call dtors to free any memory that is dynamically
192     // allocated by filebuf ctor or member functions, but don't
193     // deallocate all memory by calling operator delete.
194     buf_cout.~stdio_filebuf();
195     buf_cin.~stdio_filebuf();
196     buf_cerr.~stdio_filebuf();
197 
198 #ifdef _GLIBCPP_USE_WCHAR_T
199     buf_wcout.~stdio_filebuf();
200     buf_wcin.~stdio_filebuf();
201     buf_wcerr.~stdio_filebuf();
202 #endif
203   }
204 
205   ios_base::Init::Init()
206   {
207     if (_S_ios_base_init == 0)
208       {
209 	// Standard streams default to synced with "C" operations.
210 	ios_base::Init::_S_synced_with_stdio = true;
211 	_S_ios_create(ios_base::Init::_S_synced_with_stdio);
212       }
213     ++_S_ios_base_init;
214   }
215 
216   ios_base::Init::~Init()
217   {
218     if (--_S_ios_base_init == 0)
219       _S_ios_destroy();
220   }
221 
222   // 27.4.2.5  ios_base storage functions
223   int
224   ios_base::xalloc() throw()
225   {
226     // Implementation note: Initialize top to zero to ensure that
227     // initialization occurs before main() is started.
228     static _Atomic_word _S_top = 0;
229     return __exchange_and_add(&_S_top, 1) + 4;
230   }
231 
232   // 27.4.2.5  iword/pword storage
233   ios_base::_Words&
234   ios_base::_M_grow_words(int ix)
235   {
236     // Precondition: _M_word_size <= ix
237     int newsize = _S_local_word_size;
238     _Words* words = _M_local_word;
239     if (ix > _S_local_word_size - 1)
240       {
241 	if (ix < numeric_limits<int>::max())
242 	  {
243 	    newsize = ix + 1;
244 	    try
245 	      { words = new _Words[newsize]; }
246 	    catch (...)
247 	      {
248 		delete [] _M_word;
249 		_M_word = 0;
250 		_M_streambuf_state |= badbit;
251 		if (_M_streambuf_state & _M_exception)
252 		  __throw_ios_failure("ios_base::_M_grow_words failure");
253 		return _M_word_zero;
254 	      }
255 	    for (int i = 0; i < _M_word_size; i++)
256 	      words[i] = _M_word[i];
257 	    if (_M_word && _M_word != _M_local_word)
258 	      {
259 		delete [] _M_word;
260 		_M_word = 0;
261 	      }
262 	  }
263 	else
264 	  {
265 	    _M_streambuf_state |= badbit;
266 	    return _M_word_zero;
267 	  }
268       }
269     _M_word = words;
270     _M_word_size = newsize;
271     return _M_word[ix];
272   }
273 
274   // Called only by basic_ios<>::init.
275   void
276   ios_base::_M_init()
277   {
278     // NB: May be called more than once
279     _M_precision = 6;
280     _M_width = 0;
281     _M_flags = skipws | dec;
282     _M_callbacks = 0;
283     _M_word_size = 0;
284     _M_ios_locale = locale();
285   }
286 
287   // 27.4.2.3  ios_base locale functions
288   locale
289   ios_base::imbue(const locale& __loc)
290   {
291     locale __old = _M_ios_locale;
292     _M_ios_locale = __loc;
293     _M_call_callbacks(imbue_event);
294     return __old;
295   }
296 
297   ios_base::ios_base() : _M_callbacks(0), _M_word(0)
298   {
299     // Do nothing: basic_ios::init() does it.
300     // NB: _M_callbacks and _M_word must be zero for non-initialized
301     // ios_base to go through ~ios_base gracefully.
302   }
303 
304   // 27.4.2.7  ios_base constructors/destructors
305   ios_base::~ios_base()
306   {
307     _M_call_callbacks(erase_event);
308     _M_dispose_callbacks();
309     if (_M_word && _M_word != _M_local_word)
310       {
311 	delete [] _M_word;
312 	_M_word = 0;
313       }
314   }
315 
316   void
317   ios_base::register_callback(event_callback __fn, int __index)
318   { _M_callbacks = new _Callback_list(__fn, __index, _M_callbacks); }
319 
320   void
321   ios_base::_M_call_callbacks(event __e) throw()
322   {
323     _Callback_list* __p = _M_callbacks;
324     while (__p)
325       {
326 	try
327 	  { (*__p->_M_fn) (__e, *this, __p->_M_index); }
328 	catch (...)
329 	  { }
330 	__p = __p->_M_next;
331       }
332   }
333 
334   void
335   ios_base::_M_dispose_callbacks(void)
336   {
337     _Callback_list* __p = _M_callbacks;
338     while (__p && __p->_M_remove_reference() == 0)
339       {
340 	_Callback_list* __next = __p->_M_next;
341 	delete __p;
342 	__p = __next;
343       }
344     _M_callbacks = 0;
345   }
346 
347   bool
348   ios_base::sync_with_stdio(bool __sync)
349   {
350 #ifdef _GLIBCPP_RESOLVE_LIB_DEFECTS
351     // 49.  Underspecification of ios_base::sync_with_stdio
352     bool __ret = ios_base::Init::_S_synced_with_stdio;
353 #endif
354 
355     // Turn off sync with C FILE* for cin, cout, cerr, clog iff
356     // currently synchronized.
357     if (!__sync && __ret)
358       {
359 	ios_base::Init::_S_synced_with_stdio = false;
360 	ios_base::Init::_S_ios_destroy();
361 	ios_base::Init::_S_ios_create(ios_base::Init::_S_synced_with_stdio);
362       }
363     return __ret;
364   }
365 }  // namespace std
366