1 // Iostreams base classes -*- C++ -*- 2 3 // Copyright (C) 1997-2021 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 [ios.base.storage] 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 const char* __error = nullptr; 120 if ((unsigned)__ix >= (unsigned)numeric_limits<int>::max()) 121 __error = __N("ios_base::_M_grow_words is not valid"); 122 else if (__ix > _S_local_word_size - 1) 123 { 124 __newsize = __ix + 1; 125 /* We still need to catch bad_alloc even though we use 126 a nothrow new, because the new-expression can throw 127 a bad_array_new_length. */ 128 __try 129 { __words = new (std::nothrow) _Words[__newsize]; } 130 __catch(const std::bad_alloc&) 131 { __words = nullptr; } 132 if (!__words) 133 __error = __N("ios_base::_M_grow_words allocation failed"); 134 else 135 { 136 for (int __i = 0; __i < _M_word_size; __i++) 137 __words[__i] = _M_word[__i]; 138 if (_M_word && _M_word != _M_local_word) 139 { 140 delete [] _M_word; 141 _M_word = 0; 142 } 143 } 144 } 145 if (__error) 146 { 147 _M_streambuf_state |= badbit; 148 if (_M_streambuf_state & _M_exception) 149 __throw_ios_failure(__error); 150 if (__iword) 151 _M_word_zero._M_iword = 0; 152 else 153 _M_word_zero._M_pword = 0; 154 return _M_word_zero; 155 } 156 _M_word = __words; 157 _M_word_size = __newsize; 158 return _M_word[__ix]; 159 } 160 161 void _M_call_callbacks(event __e)162 ios_base::_M_call_callbacks(event __e) throw() 163 { 164 _Callback_list* __p = _M_callbacks; 165 while (__p) 166 { 167 __try 168 { (*__p->_M_fn) (__e, *this, __p->_M_index); } 169 __catch(...) 170 { } 171 __p = __p->_M_next; 172 } 173 } 174 175 void _M_dispose_callbacks(void)176 ios_base::_M_dispose_callbacks(void) throw() 177 { 178 _Callback_list* __p = _M_callbacks; 179 while (__p && __p->_M_remove_reference() == 0) 180 { 181 _Callback_list* __next = __p->_M_next; 182 delete __p; 183 __p = __next; 184 } 185 _M_callbacks = 0; 186 } 187 188 void _M_move(ios_base & __rhs)189 ios_base::_M_move(ios_base& __rhs) noexcept 190 { 191 _M_precision = __rhs._M_precision; 192 _M_width = __rhs._M_width; 193 _M_flags = __rhs._M_flags; 194 _M_exception = __rhs._M_exception; 195 _M_streambuf_state = __rhs._M_streambuf_state; 196 _M_callbacks = std::__exchange(__rhs._M_callbacks, nullptr); 197 if (_M_word != _M_local_word) 198 delete[] _M_word; 199 if (__rhs._M_word == __rhs._M_local_word) 200 { 201 _M_word = _M_local_word; 202 _M_word_size = _S_local_word_size; 203 for (int __i = 0; __i < _S_local_word_size; __i++) 204 _M_word[__i] = std::__exchange(__rhs._M_word[__i], {}); 205 } 206 else 207 { 208 _M_word = std::__exchange(__rhs._M_word, __rhs._M_local_word); 209 _M_word_size 210 = std::__exchange(__rhs._M_word_size, _S_local_word_size); 211 } 212 _M_ios_locale = __rhs._M_ios_locale; 213 } 214 215 void _M_swap(ios_base & __rhs)216 ios_base::_M_swap(ios_base& __rhs) noexcept 217 { 218 std::swap(_M_precision, __rhs._M_precision); 219 std::swap(_M_width, __rhs._M_width); 220 std::swap(_M_flags, __rhs._M_flags); 221 std::swap(_M_exception, __rhs._M_exception); 222 std::swap(_M_streambuf_state, __rhs._M_streambuf_state); 223 std::swap(_M_callbacks, __rhs._M_callbacks); 224 const bool __lhs_local = _M_word == _M_local_word; 225 const bool __rhs_local = __rhs._M_word == __rhs._M_local_word; 226 if (__lhs_local && __rhs_local) 227 std::swap(_M_local_word, __rhs._M_local_word); // array swap 228 else 229 { 230 if (!__lhs_local && !__rhs_local) 231 std::swap(_M_word, __rhs._M_word); 232 else 233 { 234 ios_base* __local; 235 ios_base* __allocated; 236 if (__lhs_local) 237 { 238 __local = this; 239 __allocated = &__rhs; 240 } 241 else 242 { 243 __local = &__rhs; 244 __allocated= this; 245 } 246 for (int __i = 0; __i < _S_local_word_size; __i++) 247 __allocated->_M_local_word[__i] = __local->_M_local_word[__i]; 248 __local->_M_word = __allocated->_M_word; 249 __allocated->_M_word = __allocated->_M_local_word; 250 } 251 std::swap(_M_word_size, __rhs._M_word_size); 252 } 253 std::swap(_M_ios_locale, __rhs._M_ios_locale); 254 } 255 256 _GLIBCXX_END_NAMESPACE_VERSION 257 } // namespace 258