contrib/gcc-8.0/libstdc++-v3/include/debug/functions.h

   1 // Debugging support implementation -*- C++ -*-
   2
   3 // Copyright (C) 2003-2018 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 /** @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 #if __cplusplus >= 201103L
  35 # include <type_traits>         // for is_lvalue_reference and conditional.
  36 #endif
  37
  38 #include <debug/helper_functions.h>
  39 #include <debug/formatter.h>
  40
  41 namespace __gnu_debug
  42 {
  43   template<typename _Iterator, typename _Sequence>
  44     class _Safe_iterator;
  45
  46   template<typename _Sequence>
  47     struct _Insert_range_from_self_is_safe
  48     { enum { __value = 0 }; };
  49
  50   template<typename _Sequence>
  51     struct _Is_contiguous_sequence : std::__false_type { };
  52
  53   // An arbitrary iterator pointer is not singular.
  54   inline bool
  55   __check_singular_aux(const void*) { return false; }
  56
  57   // We may have an iterator that derives from _Safe_iterator_base but isn't
  58   // a _Safe_iterator.
  59   template<typename _Iterator>
  60     inline bool
  61     __check_singular(const _Iterator& __x)
  62     { return __check_singular_aux(std::__addressof(__x)); }
  63
  64   /** Non-NULL pointers are nonsingular. */
  65   template<typename _Tp>
  66     inline bool
  67     __check_singular(const _Tp* __ptr)
  68     { return __ptr == 0; }
  69
  70   /** Assume that some arbitrary iterator is dereferenceable, because we
  71       can't prove that it isn't. */
  72   template<typename _Iterator>
  73     inline bool
  74     __check_dereferenceable(const _Iterator&)
  75     { return true; }
  76
  77   /** Non-NULL pointers are dereferenceable. */
  78   template<typename _Tp>
  79     inline bool
  80     __check_dereferenceable(const _Tp* __ptr)
  81     { return __ptr; }
  82
  83   /* Checks that [first, last) is a valid range, and then returns
  84    * __first. This routine is useful when we can't use a separate
  85    * assertion statement because, e.g., we are in a constructor.
  86   */
  87   template<typename _InputIterator>
  88     inline _InputIterator
  89     __check_valid_range(const _InputIterator& __first,
  90                         const _InputIterator& __last
  91                         __attribute__((__unused__)))
  92     {
  93       __glibcxx_check_valid_range(__first, __last);
  94       return __first;
  95     }
  96
  97   /* Handle the case where __other is a pointer to _Sequence::value_type. */
  98   template<typename _Iterator, typename _Sequence>
  99     inline bool
 100     __foreign_iterator_aux4(const _Safe_iterator<_Iterator, _Sequence>& __it,
 101                             const typename _Sequence::value_type* __other)
 102     {
 103       typedef const typename _Sequence::value_type* _PointerType;
 104       typedef std::less<_PointerType> _Less;
 105 #if __cplusplus >= 201103L
 106       constexpr _Less __l{};
 107 #else
 108       const _Less __l = _Less();
 109 #endif
 110       const _Sequence* __seq = __it._M_get_sequence();
 111       const _PointerType __begin = std::__addressof(*__seq->_M_base().begin());
 112       const _PointerType __end = std::__addressof(*(__seq->_M_base().end()-1));
 113
 114       // Check whether __other points within the contiguous storage.
 115       return __l(__other, __begin) || __l(__end, __other);
 116     }
 117
 118   /* Fallback overload for when we can't tell, assume it is valid. */
 119   template<typename _Iterator, typename _Sequence>
 120     inline bool
 121     __foreign_iterator_aux4(const _Safe_iterator<_Iterator, _Sequence>&, ...)
 122     { return true; }
 123
 124   /* Handle sequences with contiguous storage */
 125   template<typename _Iterator, typename _Sequence, typename _InputIterator>
 126     inline bool
 127     __foreign_iterator_aux3(const _Safe_iterator<_Iterator, _Sequence>& __it,
 128                             const _InputIterator& __other,
 129                             const _InputIterator& __other_end,
 130                             std::__true_type)
 131     {
 132       if (__other == __other_end)
 133         return true;  // inserting nothing is safe even if not foreign iters
 134       if (__it._M_get_sequence()->begin() == __it._M_get_sequence()->end())
 135         return true;  // can't be self-inserting if self is empty
 136       return __foreign_iterator_aux4(__it, std::__addressof(*__other));
 137     }
 138
 139   /* Handle non-contiguous containers, assume it is valid. */
 140   template<typename _Iterator, typename _Sequence, typename _InputIterator>
 141     inline bool
 142     __foreign_iterator_aux3(const _Safe_iterator<_Iterator, _Sequence>&,
 143                             const _InputIterator&, const _InputIterator&,
 144                             std::__false_type)
 145     { return true; }
 146
 147   /** Handle debug iterators from the same type of container. */
 148   template<typename _Iterator, typename _Sequence, typename _OtherIterator>
 149     inline bool
 150     __foreign_iterator_aux2(const _Safe_iterator<_Iterator, _Sequence>& __it,
 151                 const _Safe_iterator<_OtherIterator, _Sequence>& __other,
 152                 const _Safe_iterator<_OtherIterator, _Sequence>&)
 153     { return __it._M_get_sequence() != __other._M_get_sequence(); }
 154
 155   /** Handle debug iterators from different types of container. */
 156   template<typename _Iterator, typename _Sequence, typename _OtherIterator,
 157            typename _OtherSequence>
 158     inline bool
 159     __foreign_iterator_aux2(const _Safe_iterator<_Iterator, _Sequence>& __it,
 160                 const _Safe_iterator<_OtherIterator, _OtherSequence>&,
 161                 const _Safe_iterator<_OtherIterator, _OtherSequence>&)
 162     { return true; }
 163
 164   /* Handle non-debug iterators. */
 165   template<typename _Iterator, typename _Sequence, typename _InputIterator>
 166     inline bool
 167     __foreign_iterator_aux2(const _Safe_iterator<_Iterator, _Sequence>& __it,
 168                             const _InputIterator& __other,
 169                             const _InputIterator& __other_end)
 170     {
 171 #if __cplusplus < 201103L
 172       typedef _Is_contiguous_sequence<_Sequence> __tag;
 173 #else
 174       using __lvalref = std::is_lvalue_reference<
 175         typename std::iterator_traits<_InputIterator>::reference>;
 176       using __contiguous = _Is_contiguous_sequence<_Sequence>;
 177       using __tag = typename std::conditional<__lvalref::value, __contiguous,
 178                                               std::__false_type>::type;
 179 #endif
 180       return __foreign_iterator_aux3(__it, __other, __other_end, __tag());
 181     }
 182
 183   /* Handle the case where we aren't really inserting a range after all */
 184   template<typename _Iterator, typename _Sequence, typename _Integral>
 185     inline bool
 186     __foreign_iterator_aux(const _Safe_iterator<_Iterator, _Sequence>&,
 187                            _Integral, _Integral,
 188                            std::__true_type)
 189     { return true; }
 190
 191   /* Handle all iterators. */
 192   template<typename _Iterator, typename _Sequence,
 193            typename _InputIterator>
 194     inline bool
 195     __foreign_iterator_aux(const _Safe_iterator<_Iterator, _Sequence>& __it,
 196                            _InputIterator __other, _InputIterator __other_end,
 197                            std::__false_type)
 198     {
 199       return _Insert_range_from_self_is_safe<_Sequence>::__value
 200         || __foreign_iterator_aux2(__it, std::__miter_base(__other),
 201                                    std::__miter_base(__other_end));
 202     }
 203
 204   template<typename _Iterator, typename _Sequence,
 205            typename _InputIterator>
 206     inline bool
 207     __foreign_iterator(const _Safe_iterator<_Iterator, _Sequence>& __it,
 208                        _InputIterator __other, _InputIterator __other_end)
 209     {
 210       typedef typename std::__is_integer<_InputIterator>::__type _Integral;
 211       return __foreign_iterator_aux(__it, __other, __other_end, _Integral());
 212     }
 213
 214   /** Checks that __s is non-NULL or __n == 0, and then returns __s. */
 215   template<typename _CharT, typename _Integer>
 216     inline const _CharT*
 217     __check_string(const _CharT* __s,
 218                    const _Integer& __n __attribute__((__unused__)))
 219     {
 220 #ifdef _GLIBCXX_DEBUG_PEDANTIC
 221       __glibcxx_assert(__s != 0 || __n == 0);
 222 #endif
 223       return __s;
 224     }
 225
 226   /** Checks that __s is non-NULL and then returns __s. */
 227   template<typename _CharT>
 228     inline const _CharT*
 229     __check_string(const _CharT* __s)
 230     {
 231 #ifdef _GLIBCXX_DEBUG_PEDANTIC
 232       __glibcxx_assert(__s != 0);
 233 #endif
 234       return __s;
 235     }
 236
 237   // Can't check if an input iterator sequence is sorted, because we
 238   // can't step through the sequence.
 239   template<typename _InputIterator>
 240     inline bool
 241     __check_sorted_aux(const _InputIterator&, const _InputIterator&,
 242                        std::input_iterator_tag)
 243     { return true; }
 244
 245   // Can verify if a forward iterator sequence is in fact sorted using
 246   // std::__is_sorted
 247   template<typename _ForwardIterator>
 248     inline bool
 249     __check_sorted_aux(_ForwardIterator __first, _ForwardIterator __last,
 250                        std::forward_iterator_tag)
 251     {
 252       if (__first == __last)
 253         return true;
 254
 255       _ForwardIterator __next = __first;
 256       for (++__next; __next != __last; __first = __next, (void)++__next)
 257         if (*__next < *__first)
 258           return false;
 259
 260       return true;
 261     }
 262
 263   // Can't check if an input iterator sequence is sorted, because we can't step
 264   // through the sequence.
 265   template<typename _InputIterator, typename _Predicate>
 266     inline bool
 267     __check_sorted_aux(const _InputIterator&, const _InputIterator&,
 268                        _Predicate, std::input_iterator_tag)
 269     { return true; }
 270
 271   // Can verify if a forward iterator sequence is in fact sorted using
 272   // std::__is_sorted
 273   template<typename _ForwardIterator, typename _Predicate>
 274     inline bool
 275     __check_sorted_aux(_ForwardIterator __first, _ForwardIterator __last,
 276                        _Predicate __pred, std::forward_iterator_tag)
 277     {
 278       if (__first == __last)
 279         return true;
 280
 281       _ForwardIterator __next = __first;
 282       for (++__next; __next != __last; __first = __next, (void)++__next)
 283         if (__pred(*__next, *__first))
 284           return false;
 285
 286       return true;
 287     }
 288
 289   // Determine if a sequence is sorted.
 290   template<typename _InputIterator>
 291     inline bool
 292     __check_sorted(const _InputIterator& __first, const _InputIterator& __last)
 293     {
 294       // Verify that the < operator for elements in the sequence is a
 295       // StrictWeakOrdering by checking that it is irreflexive.
 296       __glibcxx_assert(__first == __last || !(*__first < *__first));
 297
 298       return __check_sorted_aux(__first, __last,
 299                                 std::__iterator_category(__first));
 300     }
 301
 302   template<typename _InputIterator, typename _Predicate>
 303     inline bool
 304     __check_sorted(const _InputIterator& __first, const _InputIterator& __last,
 305                    _Predicate __pred)
 306     {
 307       // Verify that the predicate is StrictWeakOrdering by checking that it
 308       // is irreflexive.
 309       __glibcxx_assert(__first == __last || !__pred(*__first, *__first));
 310
 311       return __check_sorted_aux(__first, __last, __pred,
 312                                 std::__iterator_category(__first));
 313     }
 314
 315   template<typename _InputIterator>
 316     inline bool
 317     __check_sorted_set_aux(const _InputIterator& __first,
 318                            const _InputIterator& __last,
 319                            std::__true_type)
 320     { return __check_sorted(__first, __last); }
 321
 322   template<typename _InputIterator>
 323     inline bool
 324     __check_sorted_set_aux(const _InputIterator&,
 325                            const _InputIterator&,
 326                            std::__false_type)
 327     { return true; }
 328
 329   template<typename _InputIterator, typename _Predicate>
 330     inline bool
 331     __check_sorted_set_aux(const _InputIterator& __first,
 332                            const _InputIterator& __last,
 333                            _Predicate __pred, std::__true_type)
 334     { return __check_sorted(__first, __last, __pred); }
 335
 336   template<typename _InputIterator, typename _Predicate>
 337     inline bool
 338     __check_sorted_set_aux(const _InputIterator&,
 339                            const _InputIterator&, _Predicate,
 340                            std::__false_type)
 341     { return true; }
 342
 343   // ... special variant used in std::merge, std::includes, std::set_*.
 344   template<typename _InputIterator1, typename _InputIterator2>
 345     inline bool
 346     __check_sorted_set(const _InputIterator1& __first,
 347                        const _InputIterator1& __last,
 348                        const _InputIterator2&)
 349     {
 350       typedef typename std::iterator_traits<_InputIterator1>::value_type
 351         _ValueType1;
 352       typedef typename std::iterator_traits<_InputIterator2>::value_type
 353         _ValueType2;
 354
 355       typedef typename std::__are_same<_ValueType1, _ValueType2>::__type
 356         _SameType;
 357       return __check_sorted_set_aux(__first, __last, _SameType());
 358     }
 359
 360   template<typename _InputIterator1, typename _InputIterator2,
 361            typename _Predicate>
 362     inline bool
 363     __check_sorted_set(const _InputIterator1& __first,
 364                        const _InputIterator1& __last,
 365                        const _InputIterator2&, _Predicate __pred)
 366     {
 367       typedef typename std::iterator_traits<_InputIterator1>::value_type
 368         _ValueType1;
 369       typedef typename std::iterator_traits<_InputIterator2>::value_type
 370         _ValueType2;
 371
 372       typedef typename std::__are_same<_ValueType1, _ValueType2>::__type
 373         _SameType;
 374       return __check_sorted_set_aux(__first, __last, __pred, _SameType());
 375    }
 376
 377   // _GLIBCXX_RESOLVE_LIB_DEFECTS
 378   // 270. Binary search requirements overly strict
 379   // Determine if a sequence is partitioned w.r.t. this element.
 380   template<typename _ForwardIterator, typename _Tp>
 381     inline bool
 382     __check_partitioned_lower(_ForwardIterator __first,
 383                               _ForwardIterator __last, const _Tp& __value)
 384     {
 385       while (__first != __last && *__first < __value)
 386         ++__first;
 387       if (__first != __last)
 388         {
 389           ++__first;
 390           while (__first != __last && !(*__first < __value))
 391             ++__first;
 392         }
 393       return __first == __last;
 394     }
 395
 396   template<typename _ForwardIterator, typename _Tp>
 397     inline bool
 398     __check_partitioned_upper(_ForwardIterator __first,
 399                               _ForwardIterator __last, const _Tp& __value)
 400     {
 401       while (__first != __last && !(__value < *__first))
 402         ++__first;
 403       if (__first != __last)
 404         {
 405           ++__first;
 406           while (__first != __last && __value < *__first)
 407             ++__first;
 408         }
 409       return __first == __last;
 410     }
 411
 412   // Determine if a sequence is partitioned w.r.t. this element.
 413   template<typename _ForwardIterator, typename _Tp, typename _Pred>
 414     inline bool
 415     __check_partitioned_lower(_ForwardIterator __first,
 416                               _ForwardIterator __last, const _Tp& __value,
 417                               _Pred __pred)
 418     {
 419       while (__first != __last && bool(__pred(*__first, __value)))
 420         ++__first;
 421       if (__first != __last)
 422         {
 423           ++__first;
 424           while (__first != __last && !bool(__pred(*__first, __value)))
 425             ++__first;
 426         }
 427       return __first == __last;
 428     }
 429
 430   template<typename _ForwardIterator, typename _Tp, typename _Pred>
 431     inline bool
 432     __check_partitioned_upper(_ForwardIterator __first,
 433                               _ForwardIterator __last, const _Tp& __value,
 434                               _Pred __pred)
 435     {
 436       while (__first != __last && !bool(__pred(__value, *__first)))
 437         ++__first;
 438       if (__first != __last)
 439         {
 440           ++__first;
 441           while (__first != __last && bool(__pred(__value, *__first)))
 442             ++__first;
 443         }
 444       return __first == __last;
 445     }
 446
 447 #if __cplusplus >= 201103L
 448   struct _Irreflexive_checker
 449   {
 450     template<typename _It>
 451       static typename std::iterator_traits<_It>::reference
 452       __deref();
 453
 454     template<typename _It,
 455              typename = decltype(__deref<_It>() < __deref<_It>())>
 456       static bool
 457       _S_is_valid(_It __it)
 458       { return !(*__it < *__it); }
 459
 460     // Fallback method if operator doesn't exist.
 461     template<typename... _Args>
 462       static bool
 463       _S_is_valid(_Args...)
 464       { return true; }
 465
 466     template<typename _It, typename _Pred, typename
 467         = decltype(std::declval<_Pred>()(__deref<_It>(), __deref<_It>()))>
 468       static bool
 469       _S_is_valid_pred(_It __it, _Pred __pred)
 470       { return !__pred(*__it, *__it); }
 471
 472     // Fallback method if predicate can't be invoked.
 473     template<typename... _Args>
 474       static bool
 475       _S_is_valid_pred(_Args...)
 476       { return true; }
 477   };
 478
 479   template<typename _Iterator>
 480     inline bool
 481     __is_irreflexive(_Iterator __it)
 482     { return _Irreflexive_checker::_S_is_valid(__it); }
 483
 484   template<typename _Iterator, typename _Pred>
 485     inline bool
 486     __is_irreflexive_pred(_Iterator __it, _Pred __pred)
 487     { return _Irreflexive_checker::_S_is_valid_pred(__it, __pred); }
 488 #endif
 489
 490 } // namespace __gnu_debug
 491
 492 #endif