libstdc++-v3/include/debug/functions.h

   1 // Debugging support implementation -*- C++ -*-
   2
   3 // Copyright (C) 2003-2019 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/functions.h
  26  *  This file is a GNU debug extension to the Standard C++ Library.
  27  */
  28
  29 #ifndef _GLIBCXX_DEBUG_FUNCTIONS_H
  30 #define _GLIBCXX_DEBUG_FUNCTIONS_H 1
  31
  32 #include <bits/move.h>          // for __addressof
  33 #include <bits/stl_function.h>  // for less
  34
  35 #if __cplusplus >= 201103L
  36 # include <bits/stl_iterator.h> // for __miter_base
  37 # include <type_traits>         // for is_lvalue_reference and conditional.
  38 #endif
  39
  40 #include <debug/helper_functions.h>
  41 #include <debug/formatter.h>
  42
  43 namespace __gnu_debug
  44 {
  45   template<typename _Sequence>
  46     struct _Insert_range_from_self_is_safe
  47     { enum { __value = 0 }; };
  48
  49   template<typename _Sequence>
  50     struct _Is_contiguous_sequence : std::__false_type { };
  51
  52   // An arbitrary iterator pointer is not singular.
  53   inline bool
  54   __check_singular_aux(const void*) { return false; }
  55
  56   // We may have an iterator that derives from _Safe_iterator_base but isn't
  57   // a _Safe_iterator.
  58   template<typename _Iterator>
  59     inline bool
  60     __check_singular(const _Iterator& __x)
  61     { return __check_singular_aux(std::__addressof(__x)); }
  62
  63   /** Non-NULL pointers are nonsingular. */
  64   template<typename _Tp>
  65     inline bool
  66     __check_singular(const _Tp* __ptr)
  67     { return __ptr == 0; }
  68
  69   /* Checks that [first, last) is a valid range, and then returns
  70    * __first. This routine is useful when we can't use a separate
  71    * assertion statement because, e.g., we are in a constructor.
  72   */
  73   template<typename _InputIterator>
  74     inline _InputIterator
  75     __check_valid_range(const _InputIterator& __first,
  76                         const _InputIterator& __last,
  77                         const char* __file,
  78                         unsigned int __line,
  79                         const char* __function)
  80     {
  81       __glibcxx_check_valid_range_at(__first, __last,
  82                                      __file, __line, __function);
  83       return __first;
  84     }
  85
  86   /* Handle the case where __other is a pointer to _Sequence::value_type. */
  87   template<typename _Iterator, typename _Sequence, typename _Category>
  88     inline bool
  89     __foreign_iterator_aux4(
  90         const _Safe_iterator<_Iterator, _Sequence, _Category>& __it,
  91         const typename _Sequence::value_type* __other)
  92     {
  93       typedef const typename _Sequence::value_type* _PointerType;
  94       typedef std::less<_PointerType> _Less;
  95 #if __cplusplus >= 201103L
  96       constexpr _Less __l{};
  97 #else
  98       const _Less __l = _Less();
  99 #endif
 100       const _Sequence* __seq = __it._M_get_sequence();
 101       const _PointerType __begin = std::__addressof(*__seq->_M_base().begin());
 102       const _PointerType __end = std::__addressof(*(__seq->_M_base().end()-1));
 103
 104       // Check whether __other points within the contiguous storage.
 105       return __l(__other, __begin) || __l(__end, __other);
 106     }
 107
 108   /* Fallback overload for when we can't tell, assume it is valid. */
 109   template<typename _Iterator, typename _Sequence, typename _Category>
 110     inline bool
 111     __foreign_iterator_aux4(
 112         const _Safe_iterator<_Iterator, _Sequence, _Category>&, ...)
 113     { return true; }
 114
 115   /* Handle sequences with contiguous storage */
 116   template<typename _Iterator, typename _Sequence, typename _Category,
 117            typename _InputIterator>
 118     inline bool
 119     __foreign_iterator_aux3(
 120         const _Safe_iterator<_Iterator, _Sequence, _Category>& __it,
 121         const _InputIterator& __other, const _InputIterator& __other_end,
 122         std::__true_type)
 123     {
 124       if (__other == __other_end)
 125         return true;  // inserting nothing is safe even if not foreign iters
 126       if (__it._M_get_sequence()->empty())
 127         return true;  // can't be self-inserting if self is empty
 128       return __foreign_iterator_aux4(__it, std::__addressof(*__other));
 129     }
 130
 131   /* Handle non-contiguous containers, assume it is valid. */
 132   template<typename _Iterator, typename _Sequence, typename _Category,
 133            typename _InputIterator>
 134     inline bool
 135     __foreign_iterator_aux3(
 136         const _Safe_iterator<_Iterator, _Sequence, _Category>&,
 137         const _InputIterator&, const _InputIterator&,
 138         std::__false_type)
 139     { return true; }
 140
 141   /** Handle debug iterators from the same type of container. */
 142   template<typename _Iterator, typename _Sequence, typename _Category,
 143            typename _OtherIterator>
 144     inline bool
 145     __foreign_iterator_aux2(
 146         const _Safe_iterator<_Iterator, _Sequence, _Category>& __it,
 147         const _Safe_iterator<_OtherIterator, _Sequence, _Category>& __other,
 148         const _Safe_iterator<_OtherIterator, _Sequence, _Category>&)
 149     { return __it._M_get_sequence() != __other._M_get_sequence(); }
 150
 151   /** Handle debug iterators from different types of container. */
 152   template<typename _Iterator, typename _Sequence, typename _Category,
 153            typename _OtherIterator, typename _OtherSequence,
 154            typename _OtherCategory>
 155     inline bool
 156     __foreign_iterator_aux2(
 157         const _Safe_iterator<_Iterator, _Sequence, _Category>&,
 158         const _Safe_iterator<_OtherIterator, _OtherSequence,
 159                              _OtherCategory>&,
 160         const _Safe_iterator<_OtherIterator, _OtherSequence,
 161                              _OtherCategory>&)
 162     { return true; }
 163
 164   /* Handle non-debug iterators. */
 165   template<typename _Iterator, typename _Sequence, typename _Category,
 166            typename _InputIterator>
 167     inline bool
 168     __foreign_iterator_aux2(
 169         const _Safe_iterator<_Iterator, _Sequence, _Category>& __it,
 170         const _InputIterator& __other,
 171         const _InputIterator& __other_end)
 172     {
 173 #if __cplusplus < 201103L
 174       typedef _Is_contiguous_sequence<_Sequence> __tag;
 175 #else
 176       using __lvalref = std::is_lvalue_reference<
 177         typename std::iterator_traits<_InputIterator>::reference>;
 178       using __contiguous = _Is_contiguous_sequence<_Sequence>;
 179       using __tag = typename std::conditional<__lvalref::value, __contiguous,
 180                                               std::__false_type>::type;
 181 #endif
 182       return __foreign_iterator_aux3(__it, __other, __other_end, __tag());
 183     }
 184
 185   /* Handle the case where we aren't really inserting a range after all */
 186   template<typename _Iterator, typename _Sequence, typename _Category,
 187            typename _Integral>
 188     inline bool
 189     __foreign_iterator_aux(
 190         const _Safe_iterator<_Iterator, _Sequence, _Category>&,
 191         _Integral, _Integral, std::__true_type)
 192     { return true; }
 193
 194   /* Handle all iterators. */
 195   template<typename _Iterator, typename _Sequence, typename _Category,
 196            typename _InputIterator>
 197     inline bool
 198     __foreign_iterator_aux(
 199         const _Safe_iterator<_Iterator, _Sequence, _Category>& __it,
 200         _InputIterator __other, _InputIterator __other_end,
 201         std::__false_type)
 202     {
 203       return _Insert_range_from_self_is_safe<_Sequence>::__value
 204         || __foreign_iterator_aux2(__it, std::__miter_base(__other),
 205                                    std::__miter_base(__other_end));
 206     }
 207
 208   template<typename _Iterator, typename _Sequence, typename _Category,
 209            typename _InputIterator>
 210     inline bool
 211     __foreign_iterator(
 212         const _Safe_iterator<_Iterator, _Sequence, _Category>& __it,
 213         _InputIterator __other, _InputIterator __other_end)
 214     {
 215       typedef typename std::__is_integer<_InputIterator>::__type _Integral;
 216       return __foreign_iterator_aux(__it, __other, __other_end, _Integral());
 217     }
 218
 219   // Can't check if an input iterator sequence is sorted, because we
 220   // can't step through the sequence.
 221   template<typename _InputIterator>
 222     inline bool
 223     __check_sorted_aux(const _InputIterator&, const _InputIterator&,
 224                        std::input_iterator_tag)
 225     { return true; }
 226
 227   // Can verify if a forward iterator sequence is in fact sorted using
 228   // std::__is_sorted
 229   template<typename _ForwardIterator>
 230     inline bool
 231     __check_sorted_aux(_ForwardIterator __first, _ForwardIterator __last,
 232                        std::forward_iterator_tag)
 233     {
 234       if (__first == __last)
 235         return true;
 236
 237       _ForwardIterator __next = __first;
 238       for (++__next; __next != __last; __first = __next, (void)++__next)
 239         if (*__next < *__first)
 240           return false;
 241
 242       return true;
 243     }
 244
 245   // Can't check if an input iterator sequence is sorted, because we can't step
 246   // through the sequence.
 247   template<typename _InputIterator, typename _Predicate>
 248     inline bool
 249     __check_sorted_aux(const _InputIterator&, const _InputIterator&,
 250                        _Predicate, std::input_iterator_tag)
 251     { return true; }
 252
 253   // Can verify if a forward iterator sequence is in fact sorted using
 254   // std::__is_sorted
 255   template<typename _ForwardIterator, typename _Predicate>
 256     inline bool
 257     __check_sorted_aux(_ForwardIterator __first, _ForwardIterator __last,
 258                        _Predicate __pred, std::forward_iterator_tag)
 259     {
 260       if (__first == __last)
 261         return true;
 262
 263       _ForwardIterator __next = __first;
 264       for (++__next; __next != __last; __first = __next, (void)++__next)
 265         if (__pred(*__next, *__first))
 266           return false;
 267
 268       return true;
 269     }
 270
 271   // Determine if a sequence is sorted.
 272   template<typename _InputIterator>
 273     inline bool
 274     __check_sorted(const _InputIterator& __first, const _InputIterator& __last)
 275     {
 276       // Verify that the < operator for elements in the sequence is a
 277       // StrictWeakOrdering by checking that it is irreflexive.
 278       __glibcxx_assert(__first == __last || !(*__first < *__first));
 279
 280       return __check_sorted_aux(__first, __last,
 281                                 std::__iterator_category(__first));
 282     }
 283
 284   template<typename _InputIterator, typename _Predicate>
 285     inline bool
 286     __check_sorted(const _InputIterator& __first, const _InputIterator& __last,
 287                    _Predicate __pred)
 288     {
 289       // Verify that the predicate is StrictWeakOrdering by checking that it
 290       // is irreflexive.
 291       __glibcxx_assert(__first == __last || !__pred(*__first, *__first));
 292
 293       return __check_sorted_aux(__first, __last, __pred,
 294                                 std::__iterator_category(__first));
 295     }
 296
 297   template<typename _InputIterator>
 298     inline bool
 299     __check_sorted_set_aux(const _InputIterator& __first,
 300                            const _InputIterator& __last,
 301                            std::__true_type)
 302     { return __check_sorted(__first, __last); }
 303
 304   template<typename _InputIterator>
 305     inline bool
 306     __check_sorted_set_aux(const _InputIterator&,
 307                            const _InputIterator&,
 308                            std::__false_type)
 309     { return true; }
 310
 311   template<typename _InputIterator, typename _Predicate>
 312     inline bool
 313     __check_sorted_set_aux(const _InputIterator& __first,
 314                            const _InputIterator& __last,
 315                            _Predicate __pred, std::__true_type)
 316     { return __check_sorted(__first, __last, __pred); }
 317
 318   template<typename _InputIterator, typename _Predicate>
 319     inline bool
 320     __check_sorted_set_aux(const _InputIterator&,
 321                            const _InputIterator&, _Predicate,
 322                            std::__false_type)
 323     { return true; }
 324
 325   // ... special variant used in std::merge, std::includes, std::set_*.
 326   template<typename _InputIterator1, typename _InputIterator2>
 327     inline bool
 328     __check_sorted_set(const _InputIterator1& __first,
 329                        const _InputIterator1& __last,
 330                        const _InputIterator2&)
 331     {
 332       typedef typename std::iterator_traits<_InputIterator1>::value_type
 333         _ValueType1;
 334       typedef typename std::iterator_traits<_InputIterator2>::value_type
 335         _ValueType2;
 336
 337       typedef typename std::__are_same<_ValueType1, _ValueType2>::__type
 338         _SameType;
 339       return __check_sorted_set_aux(__first, __last, _SameType());
 340     }
 341
 342   template<typename _InputIterator1, typename _InputIterator2,
 343            typename _Predicate>
 344     inline bool
 345     __check_sorted_set(const _InputIterator1& __first,
 346                        const _InputIterator1& __last,
 347                        const _InputIterator2&, _Predicate __pred)
 348     {
 349       typedef typename std::iterator_traits<_InputIterator1>::value_type
 350         _ValueType1;
 351       typedef typename std::iterator_traits<_InputIterator2>::value_type
 352         _ValueType2;
 353
 354       typedef typename std::__are_same<_ValueType1, _ValueType2>::__type
 355         _SameType;
 356       return __check_sorted_set_aux(__first, __last, __pred, _SameType());
 357    }
 358
 359   // _GLIBCXX_RESOLVE_LIB_DEFECTS
 360   // 270. Binary search requirements overly strict
 361   // Determine if a sequence is partitioned w.r.t. this element.
 362   template<typename _ForwardIterator, typename _Tp>
 363     inline bool
 364     __check_partitioned_lower(_ForwardIterator __first,
 365                               _ForwardIterator __last, const _Tp& __value)
 366     {
 367       while (__first != __last && *__first < __value)
 368         ++__first;
 369       if (__first != __last)
 370         {
 371           ++__first;
 372           while (__first != __last && !(*__first < __value))
 373             ++__first;
 374         }
 375       return __first == __last;
 376     }
 377
 378   template<typename _ForwardIterator, typename _Tp>
 379     inline bool
 380     __check_partitioned_upper(_ForwardIterator __first,
 381                               _ForwardIterator __last, const _Tp& __value)
 382     {
 383       while (__first != __last && !(__value < *__first))
 384         ++__first;
 385       if (__first != __last)
 386         {
 387           ++__first;
 388           while (__first != __last && __value < *__first)
 389             ++__first;
 390         }
 391       return __first == __last;
 392     }
 393
 394   // Determine if a sequence is partitioned w.r.t. this element.
 395   template<typename _ForwardIterator, typename _Tp, typename _Pred>
 396     inline bool
 397     __check_partitioned_lower(_ForwardIterator __first,
 398                               _ForwardIterator __last, const _Tp& __value,
 399                               _Pred __pred)
 400     {
 401       while (__first != __last && bool(__pred(*__first, __value)))
 402         ++__first;
 403       if (__first != __last)
 404         {
 405           ++__first;
 406           while (__first != __last && !bool(__pred(*__first, __value)))
 407             ++__first;
 408         }
 409       return __first == __last;
 410     }
 411
 412   template<typename _ForwardIterator, typename _Tp, typename _Pred>
 413     inline bool
 414     __check_partitioned_upper(_ForwardIterator __first,
 415                               _ForwardIterator __last, const _Tp& __value,
 416                               _Pred __pred)
 417     {
 418       while (__first != __last && !bool(__pred(__value, *__first)))
 419         ++__first;
 420       if (__first != __last)
 421         {
 422           ++__first;
 423           while (__first != __last && bool(__pred(__value, *__first)))
 424             ++__first;
 425         }
 426       return __first == __last;
 427     }
 428
 429 #if __cplusplus >= 201103L
 430   struct _Irreflexive_checker
 431   {
 432     template<typename _It>
 433       static typename std::iterator_traits<_It>::reference
 434       __deref();
 435
 436     template<typename _It,
 437              typename = decltype(__deref<_It>() < __deref<_It>())>
 438       static bool
 439       _S_is_valid(_It __it)
 440       { return !(*__it < *__it); }
 441
 442     // Fallback method if operator doesn't exist.
 443     template<typename... _Args>
 444       static bool
 445       _S_is_valid(_Args...)
 446       { return true; }
 447
 448     template<typename _It, typename _Pred, typename
 449         = decltype(std::declval<_Pred>()(__deref<_It>(), __deref<_It>()))>
 450       static bool
 451       _S_is_valid_pred(_It __it, _Pred __pred)
 452       { return !__pred(*__it, *__it); }
 453
 454     // Fallback method if predicate can't be invoked.
 455     template<typename... _Args>
 456       static bool
 457       _S_is_valid_pred(_Args...)
 458       { return true; }
 459   };
 460
 461   template<typename _Iterator>
 462     inline bool
 463     __is_irreflexive(_Iterator __it)
 464     { return _Irreflexive_checker::_S_is_valid(__it); }
 465
 466   template<typename _Iterator, typename _Pred>
 467     inline bool
 468     __is_irreflexive_pred(_Iterator __it, _Pred __pred)
 469     { return _Irreflexive_checker::_S_is_valid_pred(__it, __pred); }
 470 #endif
 471
 472 } // namespace __gnu_debug
 473
 474 #endif