1 // Iostreams base classes -*- C++ -*-
2 
3 // Copyright (C) 1997-2018 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 #include <ios>
30 #include <limits>
31 
32 namespace std _GLIBCXX_VISIBILITY(default)
33 {
34 _GLIBCXX_BEGIN_NAMESPACE_VERSION
35 
36   // Definitions for static const members of ios_base.
37   const ios_base::fmtflags ios_base::boolalpha;
38   const ios_base::fmtflags ios_base::dec;
39   const ios_base::fmtflags ios_base::fixed;
40   const ios_base::fmtflags ios_base::hex;
41   const ios_base::fmtflags ios_base::internal;
42   const ios_base::fmtflags ios_base::left;
43   const ios_base::fmtflags ios_base::oct;
44   const ios_base::fmtflags ios_base::right;
45   const ios_base::fmtflags ios_base::scientific;
46   const ios_base::fmtflags ios_base::showbase;
47   const ios_base::fmtflags ios_base::showpoint;
48   const ios_base::fmtflags ios_base::showpos;
49   const ios_base::fmtflags ios_base::skipws;
50   const ios_base::fmtflags ios_base::unitbuf;
51   const ios_base::fmtflags ios_base::uppercase;
52   const ios_base::fmtflags ios_base::adjustfield;
53   const ios_base::fmtflags ios_base::basefield;
54   const ios_base::fmtflags ios_base::floatfield;
55 
56   const ios_base::iostate ios_base::badbit;
57   const ios_base::iostate ios_base::eofbit;
58   const ios_base::iostate ios_base::failbit;
59   const ios_base::iostate ios_base::goodbit;
60 
61   const ios_base::openmode ios_base::app;
62   const ios_base::openmode ios_base::ate;
63   const ios_base::openmode ios_base::binary;
64   const ios_base::openmode ios_base::in;
65   const ios_base::openmode ios_base::out;
66   const ios_base::openmode ios_base::trunc;
67 
68   const ios_base::seekdir ios_base::beg;
69   const ios_base::seekdir ios_base::cur;
70   const ios_base::seekdir ios_base::end;
71 
72   _Atomic_word ios_base::Init::_S_refcount;
73 
74   bool ios_base::Init::_S_synced_with_stdio = true;
75 
ios_base()76   ios_base::ios_base() throw()
77   : _M_precision(), _M_width(), _M_flags(), _M_exception(),
78   _M_streambuf_state(), _M_callbacks(0), _M_word_zero(),
79   _M_word_size(_S_local_word_size), _M_word(_M_local_word), _M_ios_locale()
80   {
81     // Do nothing: basic_ios::init() does it.
82     // NB: _M_callbacks and _M_word must be zero for non-initialized
83     // ios_base to go through ~ios_base gracefully.
84   }
85 
86   // 27.4.2.7  ios_base constructors/destructors
~ios_base()87   ios_base::~ios_base()
88   {
89     _M_call_callbacks(erase_event);
90     _M_dispose_callbacks();
91     if (_M_word != _M_local_word)
92       {
93 	delete [] _M_word;
94 	_M_word = 0;
95       }
96   }
97 
98   // 27.4.2.5  ios_base storage functions
99   int
xalloc()100   ios_base::xalloc() throw()
101   {
102     // Implementation note: Initialize top to zero to ensure that
103     // initialization occurs before main() is started.
104     static _Atomic_word _S_top = 0;
105     return __gnu_cxx::__exchange_and_add_dispatch(&_S_top, 1) + 4;
106   }
107 
108   void
register_callback(event_callback __fn,int __index)109   ios_base::register_callback(event_callback __fn, int __index)
110   { _M_callbacks = new _Callback_list(__fn, __index, _M_callbacks); }
111 
112   // 27.4.2.5  iword/pword storage
113   ios_base::_Words&
_M_grow_words(int __ix,bool __iword)114   ios_base::_M_grow_words(int __ix, bool __iword)
115   {
116     // Precondition: _M_word_size <= __ix
117     int __newsize = _S_local_word_size;
118     _Words* __words = _M_local_word;
119     if (__ix > _S_local_word_size - 1)
120       {
121 	if (__ix < numeric_limits<int>::max())
122 	  {
123 	    __newsize = __ix + 1;
124 	    /* We still need to catch bad_alloc even though we use
125 	       a nothrow new, because the new-expression can throw
126 	       a bad_array_new_length.  */
127 	    __try
128 	      { __words = new (std::nothrow) _Words[__newsize]; }
129 	    __catch(const std::bad_alloc&)
130 	      { __words = nullptr; }
131 	    if (!__words)
132 	      {
133 		_M_streambuf_state |= badbit;
134 		if (_M_streambuf_state & _M_exception)
135 		  __throw_ios_failure(__N("ios_base::_M_grow_words "
136 					  "allocation failed"));
137 		if (__iword)
138 		  _M_word_zero._M_iword = 0;
139 		else
140 		  _M_word_zero._M_pword = 0;
141 		return _M_word_zero;
142 	      }
143 	    for (int __i = 0; __i < _M_word_size; __i++)
144 	      __words[__i] = _M_word[__i];
145 	    if (_M_word && _M_word != _M_local_word)
146 	      {
147 		delete [] _M_word;
148 		_M_word = 0;
149 	      }
150 	  }
151 	else
152 	  {
153 	    _M_streambuf_state |= badbit;
154 	    if (_M_streambuf_state & _M_exception)
155 	      __throw_ios_failure(__N("ios_base::_M_grow_words is not valid"));
156 	    if (__iword)
157 	      _M_word_zero._M_iword = 0;
158 	    else
159 	      _M_word_zero._M_pword = 0;
160 	    return _M_word_zero;
161 	  }
162       }
163     _M_word = __words;
164     _M_word_size = __newsize;
165     return _M_word[__ix];
166   }
167 
168   void
_M_call_callbacks(event __e)169   ios_base::_M_call_callbacks(event __e) throw()
170   {
171     _Callback_list* __p = _M_callbacks;
172     while (__p)
173       {
174 	__try
175 	  { (*__p->_M_fn) (__e, *this, __p->_M_index); }
176 	__catch(...)
177 	  { }
178 	__p = __p->_M_next;
179       }
180   }
181 
182   void
_M_dispose_callbacks(void)183   ios_base::_M_dispose_callbacks(void) throw()
184   {
185     _Callback_list* __p = _M_callbacks;
186     while (__p && __p->_M_remove_reference() == 0)
187       {
188 	_Callback_list* __next = __p->_M_next;
189 	delete __p;
190 	__p = __next;
191       }
192     _M_callbacks = 0;
193   }
194 
195   void
_M_move(ios_base & __rhs)196   ios_base::_M_move(ios_base& __rhs) noexcept
197   {
198     _M_precision = __rhs._M_precision;
199     _M_width = __rhs._M_width;
200     _M_flags = __rhs._M_flags;
201     _M_exception = __rhs._M_exception;
202     _M_streambuf_state = __rhs._M_streambuf_state;
203     _M_callbacks = std::__exchange(__rhs._M_callbacks, nullptr);
204     if (_M_word != _M_local_word)
205        delete[] _M_word;
206     if (__rhs._M_word == __rhs._M_local_word)
207      {
208        _M_word = _M_local_word;
209        _M_word_size = _S_local_word_size;
210        for (int __i = 0; __i < _S_local_word_size; __i++)
211 	 _M_word[__i] = std::__exchange(__rhs._M_word[__i], {});
212      }
213     else
214      {
215        _M_word = std::__exchange(__rhs._M_word, __rhs._M_local_word);
216        _M_word_size
217 	 = std::__exchange(__rhs._M_word_size, _S_local_word_size);
218      }
219     _M_ios_locale = __rhs._M_ios_locale;
220   }
221 
222   void
_M_swap(ios_base & __rhs)223   ios_base::_M_swap(ios_base& __rhs) noexcept
224   {
225     std::swap(_M_precision, __rhs._M_precision);
226     std::swap(_M_width, __rhs._M_width);
227     std::swap(_M_flags, __rhs._M_flags);
228     std::swap(_M_exception, __rhs._M_exception);
229     std::swap(_M_streambuf_state, __rhs._M_streambuf_state);
230     std::swap(_M_callbacks, __rhs._M_callbacks);
231     const bool __lhs_local = _M_word == _M_local_word;
232     const bool __rhs_local = __rhs._M_word == __rhs._M_local_word;
233     if (__lhs_local && __rhs_local)
234      std::swap(_M_local_word, __rhs._M_local_word); // array swap
235     else
236      {
237        if (!__lhs_local && !__rhs_local)
238 	 std::swap(_M_word, __rhs._M_word);
239        else
240 	 {
241 	   ios_base* __local;
242 	   ios_base* __allocated;
243 	   if (__lhs_local)
244 	     {
245 	       __local = this;
246 	       __allocated = &__rhs;
247 	     }
248 	   else
249 	     {
250 	       __local = &__rhs;
251 	       __allocated= this;
252 	     }
253 	   for (int __i = 0; __i < _S_local_word_size; __i++)
254 	     __allocated->_M_local_word[__i] = __local->_M_local_word[__i];
255 	   __local->_M_word = __allocated->_M_word;
256 	   __allocated->_M_word = __allocated->_M_local_word;
257 	 }
258        std::swap(_M_word_size, __rhs._M_word_size);
259      }
260     std::swap(_M_ios_locale, __rhs._M_ios_locale);
261   }
262 
263 _GLIBCXX_END_NAMESPACE_VERSION
264 } // namespace
265