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

   1 // Debugging support implementation -*- C++ -*-
   2
   3 // Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008
   4 // Free Software Foundation, Inc.
   5 //
   6 // This file is part of the GNU ISO C++ Library.  This library is free
   7 // software; you can redistribute it and/or modify it under the
   8 // terms of the GNU General Public License as published by the
   9 // Free Software Foundation; either version 2, or (at your option)
  10 // any later version.
  11
  12 // This library is distributed in the hope that it will be useful,
  13 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 // GNU General Public License for more details.
  16
  17 // You should have received a copy of the GNU General Public License along
  18 // with this library; see the file COPYING.  If not, write to the Free
  19 // Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
  20 // USA.
  21
  22 // As a special exception, you may use this file as part of a free software
  23 // library without restriction.  Specifically, if other files instantiate
  24 // templates or use macros or inline functions from this file, or you compile
  25 // this file and link it with other files to produce an executable, this
  26 // file does not by itself cause the resulting executable to be covered by
  27 // the GNU General Public License.  This exception does not however
  28 // invalidate any other reasons why the executable file might be covered by
  29 // the GNU General Public License.
  30
  31 /** @file debug/functions.h
  32  *  This file is a GNU debug extension to the Standard C++ Library.
  33  */
  34
  35 #ifndef _GLIBCXX_DEBUG_FUNCTIONS_H
  36 #define _GLIBCXX_DEBUG_FUNCTIONS_H 1
  37
  38 #include <bits/c++config.h>
  39 #include <cstddef>                       // for ptrdiff_t
  40 #include <bits/stl_iterator_base_types.h> // for iterator_traits, categories
  41 #include <bits/cpp_type_traits.h>         // for __is_integer
  42
  43 namespace __gnu_debug
  44 {
  45   template<typename _Iterator, typename _Sequence>
  46     class _Safe_iterator;
  47
  48   // An arbitrary iterator pointer is not singular.
  49   inline bool
  50   __check_singular_aux(const void*) { return false; }
  51
  52   // We may have an iterator that derives from _Safe_iterator_base but isn't
  53   // a _Safe_iterator.
  54   template<typename _Iterator>
  55     inline bool
  56     __check_singular(_Iterator& __x)
  57     { return __check_singular_aux(&__x); }
  58
  59   /** Non-NULL pointers are nonsingular. */
  60   template<typename _Tp>
  61     inline bool
  62     __check_singular(const _Tp* __ptr)
  63     { return __ptr == 0; }
  64
  65   /** Safe iterators know if they are singular. */
  66   template<typename _Iterator, typename _Sequence>
  67     inline bool
  68     __check_singular(const _Safe_iterator<_Iterator, _Sequence>& __x)
  69     { return __x._M_singular(); }
  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(_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   /** Safe iterators know if they are singular. */
  85   template<typename _Iterator, typename _Sequence>
  86     inline bool
  87     __check_dereferenceable(const _Safe_iterator<_Iterator, _Sequence>& __x)
  88     { return __x._M_dereferenceable(); }
  89
  90   /** If the distance between two random access iterators is
  91    *  nonnegative, assume the range is valid.
  92   */
  93   template<typename _RandomAccessIterator>
  94     inline bool
  95     __valid_range_aux2(const _RandomAccessIterator& __first,
  96                        const _RandomAccessIterator& __last,
  97                        std::random_access_iterator_tag)
  98     { return __last - __first >= 0; }
  99
 100   /** Can't test for a valid range with input iterators, because
 101    *  iteration may be destructive. So we just assume that the range
 102    *  is valid.
 103   */
 104   template<typename _InputIterator>
 105     inline bool
 106     __valid_range_aux2(const _InputIterator&, const _InputIterator&,
 107                        std::input_iterator_tag)
 108     { return true; }
 109
 110   /** We say that integral types for a valid range, and defer to other
 111    *  routines to realize what to do with integral types instead of
 112    *  iterators.
 113   */
 114   template<typename _Integral>
 115     inline bool
 116     __valid_range_aux(const _Integral&, const _Integral&, std::__true_type)
 117     { return true; }
 118
 119   /** We have iterators, so figure out what kind of iterators that are
 120    *  to see if we can check the range ahead of time.
 121   */
 122   template<typename _InputIterator>
 123     inline bool
 124     __valid_range_aux(const _InputIterator& __first,
 125                       const _InputIterator& __last, std::__false_type)
 126   {
 127     typedef typename std::iterator_traits<_InputIterator>::iterator_category
 128       _Category;
 129     return __valid_range_aux2(__first, __last, _Category());
 130   }
 131
 132   /** Don't know what these iterators are, or if they are even
 133    *  iterators (we may get an integral type for InputIterator), so
 134    *  see if they are integral and pass them on to the next phase
 135    *  otherwise.
 136   */
 137   template<typename _InputIterator>
 138     inline bool
 139     __valid_range(const _InputIterator& __first, const _InputIterator& __last)
 140     {
 141       typedef typename std::__is_integer<_InputIterator>::__type _Integral;
 142       return __valid_range_aux(__first, __last, _Integral());
 143     }
 144
 145   /** Safe iterators know how to check if they form a valid range. */
 146   template<typename _Iterator, typename _Sequence>
 147     inline bool
 148     __valid_range(const _Safe_iterator<_Iterator, _Sequence>& __first,
 149                   const _Safe_iterator<_Iterator, _Sequence>& __last)
 150     { return __first._M_valid_range(__last); }
 151
 152   /* Checks that [first, last) is a valid range, and then returns
 153    * __first. This routine is useful when we can't use a separate
 154    * assertion statement because, e.g., we are in a constructor.
 155   */
 156   template<typename _InputIterator>
 157     inline _InputIterator
 158     __check_valid_range(const _InputIterator& __first,
 159                         const _InputIterator& __last
 160                         __attribute__((__unused__)))
 161     {
 162       _GLIBCXX_DEBUG_ASSERT(__valid_range(__first, __last));
 163       return __first;
 164     }
 165
 166   /** Checks that __s is non-NULL or __n == 0, and then returns __s. */
 167   template<typename _CharT, typename _Integer>
 168     inline const _CharT*
 169     __check_string(const _CharT* __s,
 170                    const _Integer& __n __attribute__((__unused__)))
 171     {
 172 #ifdef _GLIBCXX_DEBUG_PEDANTIC
 173       _GLIBCXX_DEBUG_ASSERT(__s != 0 || __n == 0);
 174 #endif
 175       return __s;
 176     }
 177
 178   /** Checks that __s is non-NULL and then returns __s. */
 179   template<typename _CharT>
 180     inline const _CharT*
 181     __check_string(const _CharT* __s)
 182     {
 183 #ifdef _GLIBCXX_DEBUG_PEDANTIC
 184       _GLIBCXX_DEBUG_ASSERT(__s != 0);
 185 #endif
 186       return __s;
 187     }
 188
 189   // Can't check if an input iterator sequence is sorted, because we
 190   // can't step through the sequence.
 191   template<typename _InputIterator>
 192     inline bool
 193     __check_sorted_aux(const _InputIterator&, const _InputIterator&,
 194                        std::input_iterator_tag)
 195     { return true; }
 196
 197   // Can verify if a forward iterator sequence is in fact sorted using
 198   // std::__is_sorted
 199   template<typename _ForwardIterator>
 200     inline bool
 201     __check_sorted_aux(_ForwardIterator __first, _ForwardIterator __last,
 202                        std::forward_iterator_tag)
 203     {
 204       if (__first == __last)
 205         return true;
 206
 207       _ForwardIterator __next = __first;
 208       for (++__next; __next != __last; __first = __next, ++__next)
 209         if (*__next < *__first)
 210           return false;
 211
 212       return true;
 213     }
 214
 215   // Can't check if an input iterator sequence is sorted, because we can't step
 216   // through the sequence.
 217   template<typename _InputIterator, typename _Predicate>
 218     inline bool
 219     __check_sorted_aux(const _InputIterator&, const _InputIterator&,
 220                        _Predicate, std::input_iterator_tag)
 221     { return true; }
 222
 223   // Can verify if a forward iterator sequence is in fact sorted using
 224   // std::__is_sorted
 225   template<typename _ForwardIterator, typename _Predicate>
 226     inline bool
 227     __check_sorted_aux(_ForwardIterator __first, _ForwardIterator __last,
 228                        _Predicate __pred, std::forward_iterator_tag)
 229     {
 230       if (__first == __last)
 231         return true;
 232
 233       _ForwardIterator __next = __first;
 234       for (++__next; __next != __last; __first = __next, ++__next)
 235         if (__pred(*__next, *__first))
 236           return false;
 237
 238       return true;
 239     }
 240
 241   // Determine if a sequence is sorted.
 242   template<typename _InputIterator>
 243     inline bool
 244     __check_sorted(const _InputIterator& __first, const _InputIterator& __last)
 245     {
 246       typedef typename std::iterator_traits<_InputIterator>::iterator_category
 247         _Category;
 248
 249       // Verify that the < operator for elements in the sequence is a
 250       // StrictWeakOrdering by checking that it is irreflexive.
 251       _GLIBCXX_DEBUG_ASSERT(__first == __last || !(*__first < *__first));
 252
 253       return __check_sorted_aux(__first, __last, _Category());
 254     }
 255
 256   template<typename _InputIterator, typename _Predicate>
 257     inline bool
 258     __check_sorted(const _InputIterator& __first, const _InputIterator& __last,
 259                    _Predicate __pred)
 260     {
 261       typedef typename std::iterator_traits<_InputIterator>::iterator_category
 262         _Category;
 263
 264       // Verify that the predicate is StrictWeakOrdering by checking that it
 265       // is irreflexive.
 266       _GLIBCXX_DEBUG_ASSERT(__first == __last || !__pred(*__first, *__first));
 267
 268       return __check_sorted_aux(__first, __last, __pred, _Category());
 269     }
 270
 271   template<typename _InputIterator1, typename _InputIterator2>
 272     inline bool
 273     __check_sorted_set_aux(const _InputIterator1& __first,
 274                            const _InputIterator1& __last,
 275                            const _InputIterator2&, std::__true_type)
 276     { return __check_sorted(__first, __last); }
 277
 278   template<typename _InputIterator1, typename _InputIterator2>
 279     inline bool
 280     __check_sorted_set_aux(const _InputIterator1&,
 281                            const _InputIterator1&,
 282                            const _InputIterator2&, std::__false_type)
 283     { return true; }
 284
 285   template<typename _InputIterator1, typename _InputIterator2,
 286            typename _Predicate>
 287     inline bool
 288     __check_sorted_set_aux(const _InputIterator1& __first,
 289                            const _InputIterator1& __last,
 290                            const _InputIterator2&, _Predicate __pred,
 291                            std::__true_type)
 292     { return __check_sorted(__first, __last, __pred); }
 293
 294   template<typename _InputIterator1, typename _InputIterator2,
 295            typename _Predicate>
 296     inline bool
 297     __check_sorted_set_aux(const _InputIterator1&,
 298                            const _InputIterator1&,
 299                            const _InputIterator2&, _Predicate,
 300                            std::__false_type)
 301     { return true; }
 302
 303   // ... special variant used in std::merge, std::includes, std::set_*.
 304   template<typename _InputIterator1, typename _InputIterator2>
 305     inline bool
 306     __check_sorted_set(const _InputIterator1& __first,
 307                        const _InputIterator1& __last,
 308                        const _InputIterator2&)
 309     {
 310       typedef typename std::iterator_traits<_InputIterator1>::value_type
 311         _ValueType1;
 312       typedef typename std::iterator_traits<_InputIterator2>::value_type
 313         _ValueType2;
 314
 315       typedef typename std::__are_same<_ValueType1, _ValueType2>::__type
 316         _SameType;
 317       return __check_sorted_set_aux(__first, __last, _SameType());
 318     }
 319
 320   template<typename _InputIterator1, typename _InputIterator2,
 321            typename _Predicate>
 322     inline bool
 323     __check_sorted_set(const _InputIterator1& __first,
 324                        const _InputIterator1& __last,
 325                        const _InputIterator2&, _Predicate __pred)
 326     {
 327       typedef typename std::iterator_traits<_InputIterator1>::value_type
 328         _ValueType1;
 329       typedef typename std::iterator_traits<_InputIterator2>::value_type
 330         _ValueType2;
 331
 332       typedef typename std::__are_same<_ValueType1, _ValueType2>::__type
 333         _SameType;
 334       return __check_sorted_set_aux(__first, __last, __pred, _SameType());
 335    }
 336
 337   // _GLIBCXX_RESOLVE_LIB_DEFECTS
 338   // 270. Binary search requirements overly strict
 339   // Determine if a sequence is partitioned w.r.t. this element.
 340   template<typename _ForwardIterator, typename _Tp>
 341     inline bool
 342     __check_partitioned_lower(_ForwardIterator __first,
 343                               _ForwardIterator __last, const _Tp& __value)
 344     {
 345       while (__first != __last && *__first < __value)
 346         ++__first;
 347       while (__first != __last && !(*__first < __value))
 348         ++__first;
 349       return __first == __last;
 350     }
 351
 352   template<typename _ForwardIterator, typename _Tp>
 353     inline bool
 354     __check_partitioned_upper(_ForwardIterator __first,
 355                               _ForwardIterator __last, const _Tp& __value)
 356     {
 357       while (__first != __last && !(__value < *__first))
 358         ++__first;
 359       while (__first != __last && __value < *__first)
 360         ++__first;
 361       return __first == __last;
 362     }
 363
 364   // Determine if a sequence is partitioned w.r.t. this element.
 365   template<typename _ForwardIterator, typename _Tp, typename _Pred>
 366     inline bool
 367     __check_partitioned_lower(_ForwardIterator __first,
 368                               _ForwardIterator __last, const _Tp& __value,
 369                               _Pred __pred)
 370     {
 371       while (__first != __last && bool(__pred(*__first, __value)))
 372         ++__first;
 373       while (__first != __last && !bool(__pred(*__first, __value)))
 374         ++__first;
 375       return __first == __last;
 376     }
 377
 378   template<typename _ForwardIterator, typename _Tp, typename _Pred>
 379     inline bool
 380     __check_partitioned_upper(_ForwardIterator __first,
 381                               _ForwardIterator __last, const _Tp& __value,
 382                               _Pred __pred)
 383     {
 384       while (__first != __last && !bool(__pred(__value, *__first)))
 385         ++__first;
 386       while (__first != __last && bool(__pred(__value, *__first)))
 387         ++__first;
 388       return __first == __last;
 389     }
 390 } // namespace __gnu_debug
 391
 392 #endif