libstdc++
safe_iterator.tcc
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1 // Debugging iterator implementation (out of line) -*- C++ -*-
2 
3 // Copyright (C) 2003-2020 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 /** @file debug/safe_iterator.tcc
26  * This file is a GNU debug extension to the Standard C++ Library.
27  */
28 
29 #ifndef _GLIBCXX_DEBUG_SAFE_ITERATOR_TCC
30 #define _GLIBCXX_DEBUG_SAFE_ITERATOR_TCC 1
31 
32 #include <bits/stl_algobase.h>
33 
34 namespace __gnu_debug
35 {
36  template<typename _Iterator, typename _Sequence, typename _Category>
37  typename _Distance_traits<_Iterator>::__type
38  _Safe_iterator<_Iterator, _Sequence, _Category>::
39  _M_get_distance_from_begin() const
40  {
41  typedef _Sequence_traits<_Sequence> _SeqTraits;
42 
43  // No need to consider before_begin as this function is only used in
44  // _M_can_advance which won't be used for forward_list iterators.
45  if (_M_is_begin())
46  return std::make_pair(0, __dp_exact);
47 
48  if (_M_is_end())
49  return _SeqTraits::_S_size(*_M_get_sequence());
50 
51  typename _Distance_traits<_Iterator>::__type __res
52  = __get_distance(_M_get_sequence()->_M_base().begin(), base());
53 
54  if (__res.second == __dp_equality)
55  return std::make_pair(1, __dp_sign);
56 
57  return __res;
58  }
59 
60  template<typename _Iterator, typename _Sequence, typename _Category>
61  typename _Distance_traits<_Iterator>::__type
62  _Safe_iterator<_Iterator, _Sequence, _Category>::
63  _M_get_distance_to_end() const
64  {
65  typedef _Sequence_traits<_Sequence> _SeqTraits;
66 
67  // No need to consider before_begin as this function is only used in
68  // _M_can_advance which won't be used for forward_list iterators.
69  if (_M_is_begin())
70  return _SeqTraits::_S_size(*_M_get_sequence());
71 
72  if (_M_is_end())
73  return std::make_pair(0, __dp_exact);
74 
75  typename _Distance_traits<_Iterator>::__type __res
76  = __get_distance(base(), _M_get_sequence()->_M_base().end());
77 
78  if (__res.second == __dp_equality)
79  return std::make_pair(1, __dp_sign);
80 
81  return __res;
82  }
83 
84  template<typename _Iterator, typename _Sequence, typename _Category>
85  bool
86  _Safe_iterator<_Iterator, _Sequence, _Category>::
87  _M_can_advance(difference_type __n, bool __strict) const
88  {
89  if (this->_M_singular())
90  return false;
91 
92  if (__n == 0)
93  return true;
94 
95  std::pair<difference_type, _Distance_precision> __dist = __n < 0
96  ? _M_get_distance_from_begin()
97  : _M_get_distance_to_end();
98 
99  if (__n < 0)
100  __n = -__n;
101 
102  return __dist.second > __dp_sign
103  ? __dist.first >= __n
104  : !__strict && __dist.first > 0;
105  }
106 
107  template<typename _Iterator, typename _Sequence, typename _Category>
108  template<typename _Diff>
109  bool
110  _Safe_iterator<_Iterator, _Sequence, _Category>::
111  _M_can_advance(const std::pair<_Diff, _Distance_precision>& __dist,
112  int __way) const
113  {
114  return __dist.second == __dp_exact
115  ? _M_can_advance(__way * __dist.first)
116  : _M_can_advance(__way * (__dist.first == 0
117  ? 0
118  : __dist.first < 0 ? -1 : 1));
119  }
120 
121  template<typename _Iterator, typename _Sequence, typename _Category>
122  typename _Distance_traits<_Iterator>::__type
123  _Safe_iterator<_Iterator, _Sequence, _Category>::
124  _M_get_distance_to(const _Safe_iterator& __rhs) const
125  {
126  typedef typename _Distance_traits<_Iterator>::__type _Dist;
127  typedef _Sequence_traits<_Sequence> _SeqTraits;
128 
129  _Dist __base_dist = __get_distance(this->base(), __rhs.base());
130  if (__base_dist.second == __dp_exact)
131  return __base_dist;
132 
133  _Dist __seq_dist = _SeqTraits::_S_size(*this->_M_get_sequence());
134  if (this->_M_is_before_begin())
135  {
136  if (__rhs._M_is_begin())
137  return std::make_pair(1, __dp_exact);
138 
139  return __seq_dist.second == __dp_exact
140  ? std::make_pair(__seq_dist.first + 1, __dp_exact)
141  : __seq_dist;
142  }
143 
144  if (this->_M_is_begin())
145  {
146  if (__rhs._M_is_before_begin())
147  return std::make_pair(-1, __dp_exact);
148 
149  if (__rhs._M_is_end())
150  return __seq_dist;
151 
152  return std::make_pair(__seq_dist.first,
153  __seq_dist.second == __dp_exact
154  ? __dp_sign_max_size : __seq_dist.second);
155  }
156 
157  if (this->_M_is_end())
158  {
159  if (__rhs._M_is_before_begin())
160  return __seq_dist.second == __dp_exact
161  ? std::make_pair(-__seq_dist.first - 1, __dp_exact)
162  : std::make_pair(-__seq_dist.first, __dp_sign);
163 
164  if (__rhs._M_is_begin())
165  return std::make_pair(-__seq_dist.first, __seq_dist.second);
166 
167  return std::make_pair(-__seq_dist.first,
168  __seq_dist.second == __dp_exact
169  ? __dp_sign_max_size : __seq_dist.second);
170  }
171 
172  if (__rhs._M_is_before_begin())
173  return __seq_dist.second == __dp_exact
174  ? std::make_pair(__seq_dist.first - 1, __dp_exact)
175  : std::make_pair(-__seq_dist.first, __dp_sign);
176 
177  if (__rhs._M_is_begin())
178  return std::make_pair(-__seq_dist.first,
179  __seq_dist.second == __dp_exact
180  ? __dp_sign_max_size : __seq_dist.second);
181 
182  if (__rhs._M_is_end())
183  return std::make_pair(__seq_dist.first,
184  __seq_dist.second == __dp_exact
185  ? __dp_sign_max_size : __seq_dist.second);
186 
187  return std::make_pair(1, __dp_equality);
188  }
189 
190  template<typename _Iterator, typename _Sequence, typename _Category>
191  bool
192  _Safe_iterator<_Iterator, _Sequence, _Category>::
193  _M_valid_range(const _Safe_iterator& __rhs,
194  std::pair<difference_type, _Distance_precision>& __dist,
195  bool __check_dereferenceable) const
196  {
197  if (!_M_can_compare(__rhs))
198  return false;
199 
200  /* Determine iterators order */
201  __dist = _M_get_distance_to(__rhs);
202  if (__dist.second != __dp_equality)
203  {
204  // If range is not empty first iterator must be dereferenceable.
205  return __dist.first == 0
206  || (__dist.first > 0
207  && (!__check_dereferenceable || _M_dereferenceable()));
208  }
209 
210  // Assume that this is a valid range; we can't check anything else.
211  return true;
212  }
213 
214  template<typename _Iterator, typename _Sequence>
215  bool
216  _Safe_iterator<_Iterator, _Sequence, std::random_access_iterator_tag>::
217  _M_valid_range(const _Safe_iterator& __rhs,
218  std::pair<difference_type,
219  _Distance_precision>& __dist) const
220  {
221  if (!this->_M_can_compare(__rhs))
222  return false;
223 
224  /* Determine iterators order */
225  __dist = std::make_pair(__rhs.base() - this->base(), __dp_exact);
226 
227  // If range is not empty first iterator must be dereferenceable.
228  return __dist.first == 0
229  || (__dist.first > 0 && this->_M_dereferenceable());
230  }
231 } // namespace __gnu_debug
232 
233 namespace std _GLIBCXX_VISIBILITY(default)
234 {
235 _GLIBCXX_BEGIN_NAMESPACE_VERSION
236 
237  template<bool _IsMove,
238  typename _Ite, typename _Seq, typename _Cat, typename _OI>
239  _OI
240  __copy_move_a(
241  const ::__gnu_debug::_Safe_iterator<_Ite, _Seq, _Cat>& __first,
242  const ::__gnu_debug::_Safe_iterator<_Ite, _Seq, _Cat>& __last,
243  _OI __result)
244  {
245  typename ::__gnu_debug::_Distance_traits<_Ite>::__type __dist;
246  __glibcxx_check_valid_range2(__first, __last, __dist);
247  __glibcxx_check_can_increment_dist(__result, __dist, 1);
248 
249  if (__dist.second > ::__gnu_debug::__dp_equality)
250  return std::__copy_move_a<_IsMove>(__first.base(), __last.base(),
251  __result);
252 
253  return std::__copy_move_a1<_IsMove>(__first, __last, __result);
254  }
255 
256  template<bool _IsMove,
257  typename _II, typename _Ite, typename _Seq, typename _Cat>
258  __gnu_debug::_Safe_iterator<_Ite, _Seq, _Cat>
259  __copy_move_a(_II __first, _II __last,
260  const ::__gnu_debug::_Safe_iterator<_Ite, _Seq, _Cat>& __result)
261  {
262  typename ::__gnu_debug::_Distance_traits<_II>::__type __dist;
263  __glibcxx_check_valid_range2(__first, __last, __dist);
264  __glibcxx_check_can_increment_dist(__result, __dist, 1);
265 
266  if (__dist.second > ::__gnu_debug::__dp_sign
267  && __result._M_can_advance(__dist.first, true))
268  return ::__gnu_debug::_Safe_iterator<_Ite, _Seq, _Cat>(
269  std::__copy_move_a<_IsMove>(__first, __last, __result.base()),
270  __result._M_sequence);
271 
272  return std::__copy_move_a1<_IsMove>(__first, __last, __result);
273  }
274 
275  template<bool _IsMove,
276  typename _IIte, typename _ISeq, typename _ICat,
277  typename _OIte, typename _OSeq, typename _OCat>
278  ::__gnu_debug::_Safe_iterator<_OIte, _OSeq, _OCat>
279  __copy_move_a(
280  const ::__gnu_debug::_Safe_iterator<_IIte, _ISeq, _ICat>& __first,
281  const ::__gnu_debug::_Safe_iterator<_IIte, _ISeq, _ICat>& __last,
282  const ::__gnu_debug::_Safe_iterator<_OIte, _OSeq, _OCat>& __result)
283  {
284  typename ::__gnu_debug::_Distance_traits<_IIte>::__type __dist;
285  __glibcxx_check_valid_range2(__first, __last, __dist);
286  __glibcxx_check_can_increment_dist(__result, __dist, 1);
287 
288  if (__dist.second > ::__gnu_debug::__dp_equality)
289  {
290  if (__dist.second > ::__gnu_debug::__dp_sign
291  && __result._M_can_advance(__dist.first, true))
292  return ::__gnu_debug::_Safe_iterator<_OIte, _OSeq, _OCat>(
293  std::__copy_move_a<_IsMove>(__first.base(), __last.base(),
294  __result.base()),
295  __result._M_sequence);
296 
297  return std::__copy_move_a<_IsMove>(__first.base(), __last.base(),
298  __result);
299  }
300 
301  return std::__copy_move_a1<_IsMove>(__first, __last, __result);
302  }
303 
304  template<bool _IsMove,
305  typename _Ite, typename _Seq, typename _Cat, typename _OI>
306  _OI
307  __copy_move_backward_a(
308  const ::__gnu_debug::_Safe_iterator<_Ite, _Seq, _Cat>& __first,
309  const ::__gnu_debug::_Safe_iterator<_Ite, _Seq, _Cat>& __last,
310  _OI __result)
311  {
312  typename ::__gnu_debug::_Distance_traits<_Ite>::__type __dist;
313  __glibcxx_check_valid_range2(__first, __last, __dist);
314  __glibcxx_check_can_increment_dist(__result, __dist, -1);
315 
316  if (__dist.second > ::__gnu_debug::__dp_equality)
317  return std::__copy_move_backward_a<_IsMove>(
318  __first.base(), __last.base(), __result);
319 
320  return std::__copy_move_backward_a1<_IsMove>(__first, __last, __result);
321  }
322 
323  template<bool _IsMove,
324  typename _II, typename _Ite, typename _Seq, typename _Cat>
325  __gnu_debug::_Safe_iterator<_Ite, _Seq, _Cat>
326  __copy_move_backward_a(_II __first, _II __last,
327  const ::__gnu_debug::_Safe_iterator<_Ite, _Seq, _Cat>& __result)
328  {
329  typename ::__gnu_debug::_Distance_traits<_II>::__type __dist;
330  __glibcxx_check_valid_range2(__first, __last, __dist);
331  __glibcxx_check_can_increment_dist(__result, __dist, -1);
332 
333  if (__dist.second > ::__gnu_debug::__dp_sign
334  && __result._M_can_advance(-__dist.first, true))
335  return ::__gnu_debug::_Safe_iterator<_Ite, _Seq, _Cat>(
336  std::__copy_move_backward_a<_IsMove>(__first, __last,
337  __result.base()),
338  __result._M_sequence);
339 
340  return std::__copy_move_backward_a1<_IsMove>(__first, __last, __result);
341  }
342 
343  template<bool _IsMove,
344  typename _IIte, typename _ISeq, typename _ICat,
345  typename _OIte, typename _OSeq, typename _OCat>
346  ::__gnu_debug::_Safe_iterator<_OIte, _OSeq, _OCat>
347  __copy_move_backward_a(
348  const ::__gnu_debug::_Safe_iterator<_IIte, _ISeq, _ICat>& __first,
349  const ::__gnu_debug::_Safe_iterator<_IIte, _ISeq, _ICat>& __last,
350  const ::__gnu_debug::_Safe_iterator<_OIte, _OSeq, _OCat>& __result)
351  {
352  typename ::__gnu_debug::_Distance_traits<_IIte>::__type __dist;
353  __glibcxx_check_valid_range2(__first, __last, __dist);
354  __glibcxx_check_can_increment_dist(__result, __dist, -1);
355 
356  if (__dist.second > ::__gnu_debug::__dp_equality)
357  {
358  if (__dist.second > ::__gnu_debug::__dp_sign
359  && __result._M_can_advance(-__dist.first, true))
360  return ::__gnu_debug::_Safe_iterator<_OIte, _OSeq, _OCat>(
361  std::__copy_move_backward_a<_IsMove>(__first.base(), __last.base(),
362  __result.base()),
363  __result._M_sequence);
364 
365  return std::__copy_move_backward_a<_IsMove>(
366  __first.base(), __last.base(), __result);
367  }
368 
369  return std::__copy_move_backward_a1<_IsMove>(__first, __last, __result);
370  }
371 
372  template<typename _Ite, typename _Seq, typename _Cat, typename _Tp>
373  void
374  __fill_a(const ::__gnu_debug::_Safe_iterator<_Ite, _Seq, _Cat>& __first,
375  const ::__gnu_debug::_Safe_iterator<_Ite, _Seq, _Cat>& __last,
376  const _Tp& __value)
377  {
378  typename ::__gnu_debug::_Distance_traits<_Ite>::__type __dist;
379  __glibcxx_check_valid_range2(__first, __last, __dist);
380 
381  if (__dist.second > ::__gnu_debug::__dp_equality)
382  std::__fill_a(__first.base(), __last.base(), __value);
383 
384  std::__fill_a1(__first, __last, __value);
385  }
386 
387  template<typename _Ite, typename _Seq, typename _Cat, typename _Size,
388  typename _Tp>
389  ::__gnu_debug::_Safe_iterator<_Ite, _Seq, _Cat>
390  __fill_n_a(const ::__gnu_debug::_Safe_iterator<_Ite, _Seq, _Cat>& __first,
391  _Size __n, const _Tp& __value,
392  std::input_iterator_tag)
393  {
394 #if __cplusplus >= 201103L
395  static_assert(is_integral<_Size>{}, "fill_n must pass integral size");
396 #endif
397 
398  if (__n <= 0)
399  return __first;
400 
401  __glibcxx_check_can_increment(__first, __n);
402  if (__first._M_can_advance(__n, true))
403  return ::__gnu_debug::_Safe_iterator<_Ite, _Seq, _Cat>(
404  std::__fill_n_a(__first.base(), __n, __value, _Cat()),
405  __first._M_sequence);
406 
407  return std::__fill_n_a1(__first, __n, __value);
408  }
409 
410  template<typename _II1, typename _Seq1, typename _Cat1, typename _II2>
411  bool
412  __equal_aux(
413  const ::__gnu_debug::_Safe_iterator<_II1, _Seq1, _Cat1>& __first1,
414  const ::__gnu_debug::_Safe_iterator<_II1, _Seq1, _Cat1>& __last1,
415  _II2 __first2)
416  {
417  typename ::__gnu_debug::_Distance_traits<_II1>::__type __dist;
418  __glibcxx_check_valid_range2(__first1, __last1, __dist);
419  __glibcxx_check_can_increment_dist(__first2, __dist, 1);
420 
421  if (__dist.second > ::__gnu_debug::__dp_equality)
422  return std::__equal_aux(__first1.base(), __last1.base(), __first2);
423 
424  return std::__equal_aux1(__first1, __last1, __first2);
425  }
426 
427  template<typename _II1, typename _II2, typename _Seq2, typename _Cat2>
428  bool
429  __equal_aux(_II1 __first1, _II1 __last1,
430  const ::__gnu_debug::_Safe_iterator<_II2, _Seq2, _Cat2>& __first2)
431  {
432  typename ::__gnu_debug::_Distance_traits<_II1>::__type __dist;
433  __glibcxx_check_valid_range2(__first1, __last1, __dist);
434  __glibcxx_check_can_increment_dist(__first2, __dist, 1);
435 
436  if (__dist.second > ::__gnu_debug::__dp_sign
437  && __first2._M_can_advance(__dist.first, true))
438  return std::__equal_aux(__first1, __last1, __first2.base());
439 
440  return std::__equal_aux1(__first1, __last1, __first2);
441  }
442 
443  template<typename _II1, typename _Seq1, typename _Cat1,
444  typename _II2, typename _Seq2, typename _Cat2>
445  bool
446  __equal_aux(
447  const ::__gnu_debug::_Safe_iterator<_II1, _Seq1, _Cat1>& __first1,
448  const ::__gnu_debug::_Safe_iterator<_II1, _Seq1, _Cat1>& __last1,
449  const ::__gnu_debug::_Safe_iterator<_II2, _Seq2, _Cat2>& __first2)
450  {
451  typename ::__gnu_debug::_Distance_traits<_II1>::__type __dist;
452  __glibcxx_check_valid_range2(__first1, __last1, __dist);
453  __glibcxx_check_can_increment_dist(__first2, __dist, 1);
454 
455  if (__dist.second > ::__gnu_debug::__dp_equality)
456  {
457  if (__dist.second > ::__gnu_debug::__dp_sign &&
458  __first2._M_can_advance(__dist.first, true))
459  return std::__equal_aux(__first1.base(), __last1.base(),
460  __first2.base());
461  return std::__equal_aux(__first1.base(), __last1.base(), __first2);
462  }
463 
464  return __equal_aux1(__first1, __last1, __first2);
465  }
466 
467 _GLIBCXX_END_NAMESPACE_VERSION
468 } // namespace std
469 
470 #endif
std::end
_Tp * end(valarray< _Tp > &__va) noexcept
Return an iterator pointing to one past the last element of the valarray.
Definition: valarray:1234
std::begin
_Tp * begin(valarray< _Tp > &__va) noexcept
Return an iterator pointing to the first element of the valarray.
Definition: valarray:1214
std
ISO C++ entities toplevel namespace is std.
__gnu_debug
GNU debug classes for public use.
__gnu_debug::__get_distance
constexpr _Distance_traits< _Iterator >::__type __get_distance(_Iterator __lhs, _Iterator __rhs, std::random_access_iterator_tag)
Definition: helper_functions.h:94
std::input_iterator_tag
Marking input iterators.
Definition: stl_iterator_base_types.h:93
std::pair
Struct holding two objects of arbitrary type.
Definition: stl_pair.h:213
std::pair::first
_T1 first
The first member.
Definition: stl_pair.h:217
std::pair::second
_T2 second
The second member.
Definition: stl_pair.h:218
__gnu_debug::_Safe_iterator
Safe iterator wrapper.
Definition: safe_iterator.h:115