1 // Iostreams base classes -*- C++ -*-
2 
3 // Copyright (C) 1997-2016 Free Software Foundation, Inc.
4 //
5 // This file is part of the GNU ISO C++ Library.  This library is free
6 // software; you can redistribute it and/or modify it under the
7 // terms of the GNU General Public License as published by the
8 // Free Software Foundation; either version 3, or (at your option)
9 // any later version.
10 
11 // This library is distributed in the hope that it will be useful,
12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14 // GNU General Public License for more details.
15 
16 // Under Section 7 of GPL version 3, you are granted additional
17 // permissions described in the GCC Runtime Library Exception, version
18 // 3.1, as published by the Free Software Foundation.
19 
20 // You should have received a copy of the GNU General Public License and
21 // a copy of the GCC Runtime Library Exception along with this program;
22 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
23 // <http://www.gnu.org/licenses/>.
24 
25 //
26 // ISO C++ 14882: 27.4  Iostreams base classes
27 //
28 
29 // Determines the version of ios_base::failure thrown by __throw_ios_failure.
30 // If !_GLIBCXX_USE_DUAL_ABI this will get undefined automatically.
31 #define _GLIBCXX_USE_CXX11_ABI 0
32 
33 #include <ios>
34 #include <limits>
35 #include <bits/functexcept.h>
36 
37 #ifdef _GLIBCXX_USE_NLS
38 # include <libintl.h>
39 # define _(msgid)   gettext (msgid)
40 #else
41 # define _(msgid)   (msgid)
42 #endif
43 
44 namespace std _GLIBCXX_VISIBILITY(default)
45 {
46 _GLIBCXX_BEGIN_NAMESPACE_VERSION
47 
48   void
__throw_ios_failure(const char * __s)49   __throw_ios_failure(const char* __s __attribute__((unused)))
50   { _GLIBCXX_THROW_OR_ABORT(ios_base::failure(_(__s))); }
51 
52   // Definitions for static const members of ios_base.
53   const ios_base::fmtflags ios_base::boolalpha;
54   const ios_base::fmtflags ios_base::dec;
55   const ios_base::fmtflags ios_base::fixed;
56   const ios_base::fmtflags ios_base::hex;
57   const ios_base::fmtflags ios_base::internal;
58   const ios_base::fmtflags ios_base::left;
59   const ios_base::fmtflags ios_base::oct;
60   const ios_base::fmtflags ios_base::right;
61   const ios_base::fmtflags ios_base::scientific;
62   const ios_base::fmtflags ios_base::showbase;
63   const ios_base::fmtflags ios_base::showpoint;
64   const ios_base::fmtflags ios_base::showpos;
65   const ios_base::fmtflags ios_base::skipws;
66   const ios_base::fmtflags ios_base::unitbuf;
67   const ios_base::fmtflags ios_base::uppercase;
68   const ios_base::fmtflags ios_base::adjustfield;
69   const ios_base::fmtflags ios_base::basefield;
70   const ios_base::fmtflags ios_base::floatfield;
71 
72   const ios_base::iostate ios_base::badbit;
73   const ios_base::iostate ios_base::eofbit;
74   const ios_base::iostate ios_base::failbit;
75   const ios_base::iostate ios_base::goodbit;
76 
77   const ios_base::openmode ios_base::app;
78   const ios_base::openmode ios_base::ate;
79   const ios_base::openmode ios_base::binary;
80   const ios_base::openmode ios_base::in;
81   const ios_base::openmode ios_base::out;
82   const ios_base::openmode ios_base::trunc;
83 
84   const ios_base::seekdir ios_base::beg;
85   const ios_base::seekdir ios_base::cur;
86   const ios_base::seekdir ios_base::end;
87 
88   _Atomic_word ios_base::Init::_S_refcount;
89 
90   bool ios_base::Init::_S_synced_with_stdio = true;
91 
ios_base()92   ios_base::ios_base() throw()
93   : _M_precision(), _M_width(), _M_flags(), _M_exception(),
94   _M_streambuf_state(), _M_callbacks(0), _M_word_zero(),
95   _M_word_size(_S_local_word_size), _M_word(_M_local_word), _M_ios_locale()
96   {
97     // Do nothing: basic_ios::init() does it.
98     // NB: _M_callbacks and _M_word must be zero for non-initialized
99     // ios_base to go through ~ios_base gracefully.
100   }
101 
102   // 27.4.2.7  ios_base constructors/destructors
~ios_base()103   ios_base::~ios_base()
104   {
105     _M_call_callbacks(erase_event);
106     _M_dispose_callbacks();
107     if (_M_word != _M_local_word)
108       {
109 	delete [] _M_word;
110 	_M_word = 0;
111       }
112   }
113 
114   // 27.4.2.5  ios_base storage functions
115   int
xalloc()116   ios_base::xalloc() throw()
117   {
118     // Implementation note: Initialize top to zero to ensure that
119     // initialization occurs before main() is started.
120     static _Atomic_word _S_top = 0;
121     return __gnu_cxx::__exchange_and_add_dispatch(&_S_top, 1) + 4;
122   }
123 
124   void
register_callback(event_callback __fn,int __index)125   ios_base::register_callback(event_callback __fn, int __index)
126   { _M_callbacks = new _Callback_list(__fn, __index, _M_callbacks); }
127 
128   // 27.4.2.5  iword/pword storage
129   ios_base::_Words&
_M_grow_words(int __ix,bool __iword)130   ios_base::_M_grow_words(int __ix, bool __iword)
131   {
132     // Precondition: _M_word_size <= __ix
133     int __newsize = _S_local_word_size;
134     _Words* __words = _M_local_word;
135     if (__ix > _S_local_word_size - 1)
136       {
137 	if (__ix < numeric_limits<int>::max())
138 	  {
139 	    __newsize = __ix + 1;
140 	    /* We still need to catch bad_alloc even though we use
141 	       a nothrow new, because the new-expression can throw
142 	       a bad_array_new_length.  */
143 	    __try
144 	      { __words = new (std::nothrow) _Words[__newsize]; }
145 	    __catch(const std::bad_alloc&)
146 	      { __words = nullptr; }
147 	    if (!__words)
148 	      {
149 		_M_streambuf_state |= badbit;
150 		if (_M_streambuf_state & _M_exception)
151 		  __throw_ios_failure(__N("ios_base::_M_grow_words "
152 					  "allocation failed"));
153 		if (__iword)
154 		  _M_word_zero._M_iword = 0;
155 		else
156 		  _M_word_zero._M_pword = 0;
157 		return _M_word_zero;
158 	      }
159 	    for (int __i = 0; __i < _M_word_size; __i++)
160 	      __words[__i] = _M_word[__i];
161 	    if (_M_word && _M_word != _M_local_word)
162 	      {
163 		delete [] _M_word;
164 		_M_word = 0;
165 	      }
166 	  }
167 	else
168 	  {
169 	    _M_streambuf_state |= badbit;
170 	    if (_M_streambuf_state & _M_exception)
171 	      __throw_ios_failure(__N("ios_base::_M_grow_words is not valid"));
172 	    if (__iword)
173 	      _M_word_zero._M_iword = 0;
174 	    else
175 	      _M_word_zero._M_pword = 0;
176 	    return _M_word_zero;
177 	  }
178       }
179     _M_word = __words;
180     _M_word_size = __newsize;
181     return _M_word[__ix];
182   }
183 
184   void
_M_call_callbacks(event __e)185   ios_base::_M_call_callbacks(event __e) throw()
186   {
187     _Callback_list* __p = _M_callbacks;
188     while (__p)
189       {
190 	__try
191 	  { (*__p->_M_fn) (__e, *this, __p->_M_index); }
192 	__catch(...)
193 	  { }
194 	__p = __p->_M_next;
195       }
196   }
197 
198   void
_M_dispose_callbacks(void)199   ios_base::_M_dispose_callbacks(void) throw()
200   {
201     _Callback_list* __p = _M_callbacks;
202     while (__p && __p->_M_remove_reference() == 0)
203       {
204 	_Callback_list* __next = __p->_M_next;
205 	delete __p;
206 	__p = __next;
207       }
208     _M_callbacks = 0;
209   }
210 
211   void
_M_move(ios_base & __rhs)212   ios_base::_M_move(ios_base& __rhs) noexcept
213   {
214     _M_precision = __rhs._M_precision;
215     _M_width = __rhs._M_width;
216     _M_flags = __rhs._M_flags;
217     _M_exception = __rhs._M_exception;
218     _M_streambuf_state = __rhs._M_streambuf_state;
219     _M_callbacks = std::__exchange(__rhs._M_callbacks, nullptr);
220     if (_M_word != _M_local_word)
221        delete[] _M_word;
222     if (__rhs._M_word == __rhs._M_local_word)
223      {
224        _M_word = _M_local_word;
225        _M_word_size = _S_local_word_size;
226        for (int __i = 0; __i < _S_local_word_size; __i++)
227 	 _M_word[__i] = std::__exchange(__rhs._M_word[__i], {});
228      }
229     else
230      {
231        _M_word = std::__exchange(__rhs._M_word, __rhs._M_local_word);
232        _M_word_size
233 	 = std::__exchange(__rhs._M_word_size, _S_local_word_size);
234      }
235     _M_ios_locale = __rhs._M_ios_locale;
236   }
237 
238   void
_M_swap(ios_base & __rhs)239   ios_base::_M_swap(ios_base& __rhs) noexcept
240   {
241     std::swap(_M_precision, __rhs._M_precision);
242     std::swap(_M_width, __rhs._M_width);
243     std::swap(_M_flags, __rhs._M_flags);
244     std::swap(_M_exception, __rhs._M_exception);
245     std::swap(_M_streambuf_state, __rhs._M_streambuf_state);
246     std::swap(_M_callbacks, __rhs._M_callbacks);
247     const bool __lhs_local = _M_word == _M_local_word;
248     const bool __rhs_local = __rhs._M_word == __rhs._M_local_word;
249     if (__lhs_local && __rhs_local)
250      std::swap(_M_local_word, __rhs._M_local_word); // array swap
251     else
252      {
253        if (!__lhs_local && !__rhs_local)
254 	 std::swap(_M_word, __rhs._M_word);
255        else
256 	 {
257 	   ios_base* __local;
258 	   ios_base* __allocated;
259 	   if (__lhs_local)
260 	     {
261 	       __local = this;
262 	       __allocated = &__rhs;
263 	     }
264 	   else
265 	     {
266 	       __local = &__rhs;
267 	       __allocated= this;
268 	     }
269 	   for (int __i = 0; __i < _S_local_word_size; __i++)
270 	     __allocated->_M_local_word[__i] = __local->_M_local_word[__i];
271 	   __local->_M_word = __allocated->_M_word;
272 	   __allocated->_M_word = __allocated->_M_local_word;
273 	 }
274        std::swap(_M_word_size, __rhs._M_word_size);
275      }
276     std::swap(_M_ios_locale, __rhs._M_ios_locale);
277   }
278 
279 _GLIBCXX_END_NAMESPACE_VERSION
280 } // namespace
281