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

   1 // Debugging support implementation -*- C++ -*-
   2
   3 // Copyright (C) 2003-2015 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
  36                                                 // conditional.
  37 #endif
  38
  39 #include <debug/helper_functions.h>
  40 #include <debug/formatter.h>
  41
  42 namespace __gnu_debug
  43 {
  44   template<typename _Iterator, typename _Sequence>
  45     class _Safe_iterator;
  46
  47   template<typename _Sequence>
  48     struct _Insert_range_from_self_is_safe
  49     { enum { __value = 0 }; };
  50
  51   template<typename _Sequence>
  52     struct _Is_contiguous_sequence : std::__false_type { };
  53
  54   // An arbitrary iterator pointer is not singular.
  55   inline bool
  56   __check_singular_aux(const void*) { return false; }
  57
  58   // We may have an iterator that derives from _Safe_iterator_base but isn't
  59   // a _Safe_iterator.
  60   template<typename _Iterator>
  61     inline bool
  62     __check_singular(const _Iterator& __x)
  63     { return __check_singular_aux(std::__addressof(__x)); }
  64
  65   /** Non-NULL pointers are nonsingular. */
  66   template<typename _Tp>
  67     inline bool
  68     __check_singular(const _Tp* __ptr)
  69     { return __ptr == 0; }
  70
  71   /** Assume that some arbitrary iterator is dereferenceable, because we
  72       can't prove that it isn't. */
  73   template<typename _Iterator>
  74     inline bool
  75     __check_dereferenceable(const _Iterator&)
  76     { return true; }
  77
  78   /** Non-NULL pointers are dereferenceable. */
  79   template<typename _Tp>
  80     inline bool
  81     __check_dereferenceable(const _Tp* __ptr)
  82     { return __ptr; }
  83
  84   /* Checks that [first, last) is a valid range, and then returns
  85    * __first. This routine is useful when we can't use a separate
  86    * assertion statement because, e.g., we are in a constructor.
  87   */
  88   template<typename _InputIterator>
  89     inline _InputIterator
  90     __check_valid_range(const _InputIterator& __first,
  91                         const _InputIterator& __last
  92                         __attribute__((__unused__)))
  93     {
  94       __glibcxx_check_valid_range(__first, __last);
  95       return __first;
  96     }
  97
  98   /* Handle the case where __other is a pointer to _Sequence::value_type. */
  99   template<typename _Iterator, typename _Sequence>
 100     inline bool
 101     __foreign_iterator_aux4(const _Safe_iterator<_Iterator, _Sequence>& __it,
 102                             const typename _Sequence::value_type* __other)
 103     {
 104       typedef const typename _Sequence::value_type* _PointerType;
 105       typedef std::less<_PointerType> _Less;
 106 #if __cplusplus >= 201103L
 107       constexpr _Less __l{};
 108 #else
 109       const _Less __l = _Less();
 110 #endif
 111       const _Sequence* __seq = __it._M_get_sequence();
 112       const _PointerType __begin = std::__addressof(*__seq->_M_base().begin());
 113       const _PointerType __end = std::__addressof(*(__seq->_M_base().end()-1));
 114
 115       // Check whether __other points within the contiguous storage.
 116       return __l(__other, __begin) || __l(__end, __other);
 117     }
 118
 119   /* Fallback overload for when we can't tell, assume it is valid. */
 120   template<typename _Iterator, typename _Sequence>
 121     inline bool
 122     __foreign_iterator_aux4(const _Safe_iterator<_Iterator, _Sequence>&, ...)
 123     { return true; }
 124
 125   /* Handle sequences with contiguous storage */
 126   template<typename _Iterator, typename _Sequence, typename _InputIterator>
 127     inline bool
 128     __foreign_iterator_aux3(const _Safe_iterator<_Iterator, _Sequence>& __it,
 129                             const _InputIterator& __other,
 130                             const _InputIterator& __other_end,
 131                             std::__true_type)
 132     {
 133       if (__other == __other_end)
 134         return true;  // inserting nothing is safe even if not foreign iters
 135       if (__it._M_get_sequence()->begin() == __it._M_get_sequence()->end())
 136         return true;  // can't be self-inserting if self is empty
 137       return __foreign_iterator_aux4(__it, std::__addressof(*__other));
 138     }
 139
 140   /* Handle non-contiguous containers, assume it is valid. */
 141   template<typename _Iterator, typename _Sequence, typename _InputIterator>
 142     inline bool
 143     __foreign_iterator_aux3(const _Safe_iterator<_Iterator, _Sequence>&,
 144                             const _InputIterator&, const _InputIterator&,
 145                             std::__false_type)
 146     { return true; }
 147
 148   /** Handle debug iterators from the same type of container. */
 149   template<typename _Iterator, typename _Sequence, typename _OtherIterator>
 150     inline bool
 151     __foreign_iterator_aux2(const _Safe_iterator<_Iterator, _Sequence>& __it,
 152                 const _Safe_iterator<_OtherIterator, _Sequence>& __other,
 153                 const _Safe_iterator<_OtherIterator, _Sequence>&)
 154     { return __it._M_get_sequence() != __other._M_get_sequence(); }
 155
 156   /** Handle debug iterators from different types of container. */
 157   template<typename _Iterator, typename _Sequence, typename _OtherIterator,
 158            typename _OtherSequence>
 159     inline bool
 160     __foreign_iterator_aux2(const _Safe_iterator<_Iterator, _Sequence>& __it,
 161                 const _Safe_iterator<_OtherIterator, _OtherSequence>&,
 162                 const _Safe_iterator<_OtherIterator, _OtherSequence>&)
 163     { return true; }
 164
 165   /* Handle non-debug iterators. */
 166   template<typename _Iterator, typename _Sequence, typename _InputIterator>
 167     inline bool
 168     __foreign_iterator_aux2(const _Safe_iterator<_Iterator, _Sequence>& __it,
 169                             const _InputIterator& __other,
 170                             const _InputIterator& __other_end)
 171     {
 172 #if __cplusplus < 201103L
 173       typedef _Is_contiguous_sequence<_Sequence> __tag;
 174 #else
 175       using __lvalref = std::is_lvalue_reference<
 176         typename std::iterator_traits<_InputIterator>::reference>;
 177       using __contiguous = _Is_contiguous_sequence<_Sequence>;
 178       using __tag = typename std::conditional<__lvalref::value, __contiguous,
 179                                               std::__false_type>::type;
 180 #endif
 181       return __foreign_iterator_aux3(__it, __other, __other_end, __tag());
 182     }
 183
 184   /* Handle the case where we aren't really inserting a range after all */
 185   template<typename _Iterator, typename _Sequence, typename _Integral>
 186     inline bool
 187     __foreign_iterator_aux(const _Safe_iterator<_Iterator, _Sequence>&,
 188                            _Integral, _Integral,
 189                            std::__true_type)
 190     { return true; }
 191
 192   /* Handle all iterators. */
 193   template<typename _Iterator, typename _Sequence,
 194            typename _InputIterator>
 195     inline bool
 196     __foreign_iterator_aux(const _Safe_iterator<_Iterator, _Sequence>& __it,
 197                            _InputIterator __other, _InputIterator __other_end,
 198                            std::__false_type)
 199     {
 200       return _Insert_range_from_self_is_safe<_Sequence>::__value
 201         || __foreign_iterator_aux2(__it, std::__miter_base(__other),
 202                                    std::__miter_base(__other_end));
 203     }
 204
 205   template<typename _Iterator, typename _Sequence,
 206            typename _InputIterator>
 207     inline bool
 208     __foreign_iterator(const _Safe_iterator<_Iterator, _Sequence>& __it,
 209                        _InputIterator __other, _InputIterator __other_end)
 210     {
 211       typedef typename std::__is_integer<_InputIterator>::__type _Integral;
 212       return __foreign_iterator_aux(__it, __other, __other_end, _Integral());
 213     }
 214
 215   /** Checks that __s is non-NULL or __n == 0, and then returns __s. */
 216   template<typename _CharT, typename _Integer>
 217     inline const _CharT*
 218     __check_string(const _CharT* __s,
 219                    const _Integer& __n __attribute__((__unused__)))
 220     {
 221 #ifdef _GLIBCXX_DEBUG_PEDANTIC
 222       __glibcxx_assert(__s != 0 || __n == 0);
 223 #endif
 224       return __s;
 225     }
 226
 227   /** Checks that __s is non-NULL and then returns __s. */
 228   template<typename _CharT>
 229     inline const _CharT*
 230     __check_string(const _CharT* __s)
 231     {
 232 #ifdef _GLIBCXX_DEBUG_PEDANTIC
 233       __glibcxx_assert(__s != 0);
 234 #endif
 235       return __s;
 236     }
 237
 238   // Can't check if an input iterator sequence is sorted, because we
 239   // can't step through the sequence.
 240   template<typename _InputIterator>
 241     inline bool
 242     __check_sorted_aux(const _InputIterator&, const _InputIterator&,
 243                        std::input_iterator_tag)
 244     { return true; }
 245
 246   // Can verify if a forward iterator sequence is in fact sorted using
 247   // std::__is_sorted
 248   template<typename _ForwardIterator>
 249     inline bool
 250     __check_sorted_aux(_ForwardIterator __first, _ForwardIterator __last,
 251                        std::forward_iterator_tag)
 252     {
 253       if (__first == __last)
 254         return true;
 255
 256       _ForwardIterator __next = __first;
 257       for (++__next; __next != __last; __first = __next, (void)++__next)
 258         if (*__next < *__first)
 259           return false;
 260
 261       return true;
 262     }
 263
 264   // Can't check if an input iterator sequence is sorted, because we can't step
 265   // through the sequence.
 266   template<typename _InputIterator, typename _Predicate>
 267     inline bool
 268     __check_sorted_aux(const _InputIterator&, const _InputIterator&,
 269                        _Predicate, std::input_iterator_tag)
 270     { return true; }
 271
 272   // Can verify if a forward iterator sequence is in fact sorted using
 273   // std::__is_sorted
 274   template<typename _ForwardIterator, typename _Predicate>
 275     inline bool
 276     __check_sorted_aux(_ForwardIterator __first, _ForwardIterator __last,
 277                        _Predicate __pred, std::forward_iterator_tag)
 278     {
 279       if (__first == __last)
 280         return true;
 281
 282       _ForwardIterator __next = __first;
 283       for (++__next; __next != __last; __first = __next, (void)++__next)
 284         if (__pred(*__next, *__first))
 285           return false;
 286
 287       return true;
 288     }
 289
 290   // Determine if a sequence is sorted.
 291   template<typename _InputIterator>
 292     inline bool
 293     __check_sorted(const _InputIterator& __first, const _InputIterator& __last)
 294     {
 295       // Verify that the < operator for elements in the sequence is a
 296       // StrictWeakOrdering by checking that it is irreflexive.
 297       __glibcxx_assert(__first == __last || !(*__first < *__first));
 298
 299       return __check_sorted_aux(__first, __last,
 300                                 std::__iterator_category(__first));
 301     }
 302
 303   template<typename _InputIterator, typename _Predicate>
 304     inline bool
 305     __check_sorted(const _InputIterator& __first, const _InputIterator& __last,
 306                    _Predicate __pred)
 307     {
 308       // Verify that the predicate is StrictWeakOrdering by checking that it
 309       // is irreflexive.
 310       __glibcxx_assert(__first == __last || !__pred(*__first, *__first));
 311
 312       return __check_sorted_aux(__first, __last, __pred,
 313                                 std::__iterator_category(__first));
 314     }
 315
 316   template<typename _InputIterator>
 317     inline bool
 318     __check_sorted_set_aux(const _InputIterator& __first,
 319                            const _InputIterator& __last,
 320                            std::__true_type)
 321     { return __check_sorted(__first, __last); }
 322
 323   template<typename _InputIterator>
 324     inline bool
 325     __check_sorted_set_aux(const _InputIterator&,
 326                            const _InputIterator&,
 327                            std::__false_type)
 328     { return true; }
 329
 330   template<typename _InputIterator, typename _Predicate>
 331     inline bool
 332     __check_sorted_set_aux(const _InputIterator& __first,
 333                            const _InputIterator& __last,
 334                            _Predicate __pred, std::__true_type)
 335     { return __check_sorted(__first, __last, __pred); }
 336
 337   template<typename _InputIterator, typename _Predicate>
 338     inline bool
 339     __check_sorted_set_aux(const _InputIterator&,
 340                            const _InputIterator&, _Predicate,
 341                            std::__false_type)
 342     { return true; }
 343
 344   // ... special variant used in std::merge, std::includes, std::set_*.
 345   template<typename _InputIterator1, typename _InputIterator2>
 346     inline bool
 347     __check_sorted_set(const _InputIterator1& __first,
 348                        const _InputIterator1& __last,
 349                        const _InputIterator2&)
 350     {
 351       typedef typename std::iterator_traits<_InputIterator1>::value_type
 352         _ValueType1;
 353       typedef typename std::iterator_traits<_InputIterator2>::value_type
 354         _ValueType2;
 355
 356       typedef typename std::__are_same<_ValueType1, _ValueType2>::__type
 357         _SameType;
 358       return __check_sorted_set_aux(__first, __last, _SameType());
 359     }
 360
 361   template<typename _InputIterator1, typename _InputIterator2,
 362            typename _Predicate>
 363     inline bool
 364     __check_sorted_set(const _InputIterator1& __first,
 365                        const _InputIterator1& __last,
 366                        const _InputIterator2&, _Predicate __pred)
 367     {
 368       typedef typename std::iterator_traits<_InputIterator1>::value_type
 369         _ValueType1;
 370       typedef typename std::iterator_traits<_InputIterator2>::value_type
 371         _ValueType2;
 372
 373       typedef typename std::__are_same<_ValueType1, _ValueType2>::__type
 374         _SameType;
 375       return __check_sorted_set_aux(__first, __last, __pred, _SameType());
 376    }
 377
 378   // _GLIBCXX_RESOLVE_LIB_DEFECTS
 379   // 270. Binary search requirements overly strict
 380   // Determine if a sequence is partitioned w.r.t. this element.
 381   template<typename _ForwardIterator, typename _Tp>
 382     inline bool
 383     __check_partitioned_lower(_ForwardIterator __first,
 384                               _ForwardIterator __last, const _Tp& __value)
 385     {
 386       while (__first != __last && *__first < __value)
 387         ++__first;
 388       if (__first != __last)
 389         {
 390           ++__first;
 391           while (__first != __last && !(*__first < __value))
 392             ++__first;
 393         }
 394       return __first == __last;
 395     }
 396
 397   template<typename _ForwardIterator, typename _Tp>
 398     inline bool
 399     __check_partitioned_upper(_ForwardIterator __first,
 400                               _ForwardIterator __last, const _Tp& __value)
 401     {
 402       while (__first != __last && !(__value < *__first))
 403         ++__first;
 404       if (__first != __last)
 405         {
 406           ++__first;
 407           while (__first != __last && __value < *__first)
 408             ++__first;
 409         }
 410       return __first == __last;
 411     }
 412
 413   // Determine if a sequence is partitioned w.r.t. this element.
 414   template<typename _ForwardIterator, typename _Tp, typename _Pred>
 415     inline bool
 416     __check_partitioned_lower(_ForwardIterator __first,
 417                               _ForwardIterator __last, const _Tp& __value,
 418                               _Pred __pred)
 419     {
 420       while (__first != __last && bool(__pred(*__first, __value)))
 421         ++__first;
 422       if (__first != __last)
 423         {
 424           ++__first;
 425           while (__first != __last && !bool(__pred(*__first, __value)))
 426             ++__first;
 427         }
 428       return __first == __last;
 429     }
 430
 431   template<typename _ForwardIterator, typename _Tp, typename _Pred>
 432     inline bool
 433     __check_partitioned_upper(_ForwardIterator __first,
 434                               _ForwardIterator __last, const _Tp& __value,
 435                               _Pred __pred)
 436     {
 437       while (__first != __last && !bool(__pred(__value, *__first)))
 438         ++__first;
 439       if (__first != __last)
 440         {
 441           ++__first;
 442           while (__first != __last && bool(__pred(__value, *__first)))
 443             ++__first;
 444         }
 445       return __first == __last;
 446     }
 447
 448 #if __cplusplus >= 201103L
 449   struct _Irreflexive_checker
 450   {
 451     template<typename _It>
 452       static typename std::iterator_traits<_It>::reference
 453       __deref();
 454
 455     template<typename _It,
 456              typename = decltype(__deref<_It>() < __deref<_It>())>
 457       static bool
 458       _S_is_valid(_It __it)
 459       { return !(*__it < *__it); }
 460
 461     // Fallback method if operator doesn't exist.
 462     template<typename... _Args>
 463       static bool
 464       _S_is_valid(_Args...)
 465       { return true; }
 466
 467     template<typename _It, typename _Pred, typename
 468         = decltype(std::declval<_Pred>()(__deref<_It>(), __deref<_It>()))>
 469       static bool
 470       _S_is_valid_pred(_It __it, _Pred __pred)
 471       { return !__pred(*__it, *__it); }
 472
 473     // Fallback method if predicate can't be invoked.
 474     template<typename... _Args>
 475       static bool
 476       _S_is_valid_pred(_Args...)
 477       { return true; }
 478   };
 479
 480   template<typename _Iterator>
 481     inline bool
 482     __is_irreflexive(_Iterator __it)
 483     { return _Irreflexive_checker::_S_is_valid(__it); }
 484
 485   template<typename _Iterator, typename _Pred>
 486     inline bool
 487     __is_irreflexive_pred(_Iterator __it, _Pred __pred)
 488     { return _Irreflexive_checker::_S_is_valid_pred(__it, __pred); }
 489 #endif
 490
 491 } // namespace __gnu_debug
 492
 493 #endif