1 // Debugging support implementation -*- C++ -*-
2 
3 // Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011
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 3, 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 // Under Section 7 of GPL version 3, you are granted additional
18 // permissions described in the GCC Runtime Library Exception, version
19 // 3.1, as published by the Free Software Foundation.
20 
21 // You should have received a copy of the GNU General Public License and
22 // a copy of the GCC Runtime Library Exception along with this program;
23 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
24 // <http://www.gnu.org/licenses/>.
25 
26 /** @file debug/functions.h
27  *  This file is a GNU debug extension to the Standard C++ Library.
28  */
29 
30 #ifndef _GLIBCXX_DEBUG_FUNCTIONS_H
31 #define _GLIBCXX_DEBUG_FUNCTIONS_H 1
32 
33 #include <bits/c++config.h>
34 #include <bits/stl_iterator_base_types.h> // for iterator_traits, categories
35 #include <bits/cpp_type_traits.h>         // for __is_integer
36 #include <debug/formatter.h>
37 
38 namespace __gnu_debug
39 {
40   template<typename _Iterator, typename _Sequence>
41     class _Safe_iterator;
42 
43   // An arbitrary iterator pointer is not singular.
44   inline bool
45   __check_singular_aux(const void*) { return false; }
46 
47   // We may have an iterator that derives from _Safe_iterator_base but isn't
48   // a _Safe_iterator.
49   template<typename _Iterator>
50     inline bool
51     __check_singular(_Iterator& __x)
52     { return __check_singular_aux(&__x); }
53 
54   /** Non-NULL pointers are nonsingular. */
55   template<typename _Tp>
56     inline bool
57     __check_singular(const _Tp* __ptr)
58     { return __ptr == 0; }
59 
60   /** Safe iterators know if they are singular. */
61   template<typename _Iterator, typename _Sequence>
62     inline bool
63     __check_singular(const _Safe_iterator<_Iterator, _Sequence>& __x)
64     { return __x._M_singular(); }
65 
66   /** Assume that some arbitrary iterator is dereferenceable, because we
67       can't prove that it isn't. */
68   template<typename _Iterator>
69     inline bool
70     __check_dereferenceable(_Iterator&)
71     { return true; }
72 
73   /** Non-NULL pointers are dereferenceable. */
74   template<typename _Tp>
75     inline bool
76     __check_dereferenceable(const _Tp* __ptr)
77     { return __ptr; }
78 
79   /** Safe iterators know if they are singular. */
80   template<typename _Iterator, typename _Sequence>
81     inline bool
82     __check_dereferenceable(const _Safe_iterator<_Iterator, _Sequence>& __x)
83     { return __x._M_dereferenceable(); }
84 
85   /** If the distance between two random access iterators is
86    *  nonnegative, assume the range is valid.
87   */
88   template<typename _RandomAccessIterator>
89     inline bool
90     __valid_range_aux2(const _RandomAccessIterator& __first,
91 		       const _RandomAccessIterator& __last,
92 		       std::random_access_iterator_tag)
93     { return __last - __first >= 0; }
94 
95   /** Can't test for a valid range with input iterators, because
96    *  iteration may be destructive. So we just assume that the range
97    *  is valid.
98   */
99   template<typename _InputIterator>
100     inline bool
101     __valid_range_aux2(const _InputIterator&, const _InputIterator&,
102 		       std::input_iterator_tag)
103     { return true; }
104 
105   /** We say that integral types for a valid range, and defer to other
106    *  routines to realize what to do with integral types instead of
107    *  iterators.
108   */
109   template<typename _Integral>
110     inline bool
111     __valid_range_aux(const _Integral&, const _Integral&, std::__true_type)
112     { return true; }
113 
114   /** We have iterators, so figure out what kind of iterators that are
115    *  to see if we can check the range ahead of time.
116   */
117   template<typename _InputIterator>
118     inline bool
119     __valid_range_aux(const _InputIterator& __first,
120 		      const _InputIterator& __last, std::__false_type)
121   {
122     typedef typename std::iterator_traits<_InputIterator>::iterator_category
123       _Category;
124     return __valid_range_aux2(__first, __last, _Category());
125   }
126 
127   /** Don't know what these iterators are, or if they are even
128    *  iterators (we may get an integral type for InputIterator), so
129    *  see if they are integral and pass them on to the next phase
130    *  otherwise.
131   */
132   template<typename _InputIterator>
133     inline bool
134     __valid_range(const _InputIterator& __first, const _InputIterator& __last)
135     {
136       typedef typename std::__is_integer<_InputIterator>::__type _Integral;
137       return __valid_range_aux(__first, __last, _Integral());
138     }
139 
140   /** Safe iterators know how to check if they form a valid range. */
141   template<typename _Iterator, typename _Sequence>
142     inline bool
143     __valid_range(const _Safe_iterator<_Iterator, _Sequence>& __first,
144 		  const _Safe_iterator<_Iterator, _Sequence>& __last)
145     { return __first._M_valid_range(__last); }
146 
147   /** Safe local iterators know how to check if they form a valid range. */
148   template<typename _Iterator, typename _Sequence>
149     inline bool
150     __valid_range(const _Safe_local_iterator<_Iterator, _Sequence>& __first,
151 		  const _Safe_local_iterator<_Iterator, _Sequence>& __last)
152     { return __first._M_valid_range(__last); }
153 
154   /* Checks that [first, last) is a valid range, and then returns
155    * __first. This routine is useful when we can't use a separate
156    * assertion statement because, e.g., we are in a constructor.
157   */
158   template<typename _InputIterator>
159     inline _InputIterator
160     __check_valid_range(const _InputIterator& __first,
161 			const _InputIterator& __last
162 			__attribute__((__unused__)))
163     {
164       __glibcxx_check_valid_range(__first, __last);
165       return __first;
166     }
167 
168   /** Checks that __s is non-NULL or __n == 0, and then returns __s. */
169   template<typename _CharT, typename _Integer>
170     inline const _CharT*
171     __check_string(const _CharT* __s,
172 		   const _Integer& __n __attribute__((__unused__)))
173     {
174 #ifdef _GLIBCXX_DEBUG_PEDANTIC
175       __glibcxx_assert(__s != 0 || __n == 0);
176 #endif
177       return __s;
178     }
179 
180   /** Checks that __s is non-NULL and then returns __s. */
181   template<typename _CharT>
182     inline const _CharT*
183     __check_string(const _CharT* __s)
184     {
185 #ifdef _GLIBCXX_DEBUG_PEDANTIC
186       __glibcxx_assert(__s != 0);
187 #endif
188       return __s;
189     }
190 
191   // Can't check if an input iterator sequence is sorted, because we
192   // can't step through the sequence.
193   template<typename _InputIterator>
194     inline bool
195     __check_sorted_aux(const _InputIterator&, const _InputIterator&,
196                        std::input_iterator_tag)
197     { return true; }
198 
199   // Can verify if a forward iterator sequence is in fact sorted using
200   // std::__is_sorted
201   template<typename _ForwardIterator>
202     inline bool
203     __check_sorted_aux(_ForwardIterator __first, _ForwardIterator __last,
204                        std::forward_iterator_tag)
205     {
206       if (__first == __last)
207         return true;
208 
209       _ForwardIterator __next = __first;
210       for (++__next; __next != __last; __first = __next, ++__next)
211         if (*__next < *__first)
212           return false;
213 
214       return true;
215     }
216 
217   // Can't check if an input iterator sequence is sorted, because we can't step
218   // through the sequence.
219   template<typename _InputIterator, typename _Predicate>
220     inline bool
221     __check_sorted_aux(const _InputIterator&, const _InputIterator&,
222                        _Predicate, std::input_iterator_tag)
223     { return true; }
224 
225   // Can verify if a forward iterator sequence is in fact sorted using
226   // std::__is_sorted
227   template<typename _ForwardIterator, typename _Predicate>
228     inline bool
229     __check_sorted_aux(_ForwardIterator __first, _ForwardIterator __last,
230                        _Predicate __pred, std::forward_iterator_tag)
231     {
232       if (__first == __last)
233         return true;
234 
235       _ForwardIterator __next = __first;
236       for (++__next; __next != __last; __first = __next, ++__next)
237         if (__pred(*__next, *__first))
238           return false;
239 
240       return true;
241     }
242 
243   // Determine if a sequence is sorted.
244   template<typename _InputIterator>
245     inline bool
246     __check_sorted(const _InputIterator& __first, const _InputIterator& __last)
247     {
248       typedef typename std::iterator_traits<_InputIterator>::iterator_category
249         _Category;
250 
251       // Verify that the < operator for elements in the sequence is a
252       // StrictWeakOrdering by checking that it is irreflexive.
253       __glibcxx_assert(__first == __last || !(*__first < *__first));
254 
255       return __check_sorted_aux(__first, __last, _Category());
256     }
257 
258   template<typename _InputIterator, typename _Predicate>
259     inline bool
260     __check_sorted(const _InputIterator& __first, const _InputIterator& __last,
261                    _Predicate __pred)
262     {
263       typedef typename std::iterator_traits<_InputIterator>::iterator_category
264         _Category;
265 
266       // Verify that the predicate is StrictWeakOrdering by checking that it
267       // is irreflexive.
268       __glibcxx_assert(__first == __last || !__pred(*__first, *__first));
269 
270       return __check_sorted_aux(__first, __last, __pred, _Category());
271     }
272 
273   template<typename _InputIterator>
274     inline bool
275     __check_sorted_set_aux(const _InputIterator& __first,
276 			   const _InputIterator& __last,
277 			   std::__true_type)
278     { return __check_sorted(__first, __last); }
279 
280   template<typename _InputIterator>
281     inline bool
282     __check_sorted_set_aux(const _InputIterator&,
283 			   const _InputIterator&,
284 			   std::__false_type)
285     { return true; }
286 
287   template<typename _InputIterator, typename _Predicate>
288     inline bool
289     __check_sorted_set_aux(const _InputIterator& __first,
290 			   const _InputIterator& __last,
291 			   _Predicate __pred, std::__true_type)
292     { return __check_sorted(__first, __last, __pred); }
293 
294   template<typename _InputIterator, typename _Predicate>
295     inline bool
296     __check_sorted_set_aux(const _InputIterator&,
297 			   const _InputIterator&, _Predicate,
298 			   std::__false_type)
299     { return true; }
300 
301   // ... special variant used in std::merge, std::includes, std::set_*.
302   template<typename _InputIterator1, typename _InputIterator2>
303     inline bool
304     __check_sorted_set(const _InputIterator1& __first,
305 		       const _InputIterator1& __last,
306 		       const _InputIterator2&)
307     {
308       typedef typename std::iterator_traits<_InputIterator1>::value_type
309 	_ValueType1;
310       typedef typename std::iterator_traits<_InputIterator2>::value_type
311 	_ValueType2;
312 
313       typedef typename std::__are_same<_ValueType1, _ValueType2>::__type
314 	_SameType;
315       return __check_sorted_set_aux(__first, __last, _SameType());
316     }
317 
318   template<typename _InputIterator1, typename _InputIterator2,
319 	   typename _Predicate>
320     inline bool
321     __check_sorted_set(const _InputIterator1& __first,
322 		       const _InputIterator1& __last,
323 		       const _InputIterator2&, _Predicate __pred)
324     {
325       typedef typename std::iterator_traits<_InputIterator1>::value_type
326 	_ValueType1;
327       typedef typename std::iterator_traits<_InputIterator2>::value_type
328 	_ValueType2;
329 
330       typedef typename std::__are_same<_ValueType1, _ValueType2>::__type
331 	_SameType;
332       return __check_sorted_set_aux(__first, __last, __pred, _SameType());
333    }
334 
335   // _GLIBCXX_RESOLVE_LIB_DEFECTS
336   // 270. Binary search requirements overly strict
337   // Determine if a sequence is partitioned w.r.t. this element.
338   template<typename _ForwardIterator, typename _Tp>
339     inline bool
340     __check_partitioned_lower(_ForwardIterator __first,
341 			      _ForwardIterator __last, const _Tp& __value)
342     {
343       while (__first != __last && *__first < __value)
344 	++__first;
345       while (__first != __last && !(*__first < __value))
346 	++__first;
347       return __first == __last;
348     }
349 
350   template<typename _ForwardIterator, typename _Tp>
351     inline bool
352     __check_partitioned_upper(_ForwardIterator __first,
353 			      _ForwardIterator __last, const _Tp& __value)
354     {
355       while (__first != __last && !(__value < *__first))
356 	++__first;
357       while (__first != __last && __value < *__first)
358 	++__first;
359       return __first == __last;
360     }
361 
362   // Determine if a sequence is partitioned w.r.t. this element.
363   template<typename _ForwardIterator, typename _Tp, typename _Pred>
364     inline bool
365     __check_partitioned_lower(_ForwardIterator __first,
366 			      _ForwardIterator __last, const _Tp& __value,
367 			      _Pred __pred)
368     {
369       while (__first != __last && bool(__pred(*__first, __value)))
370 	++__first;
371       while (__first != __last && !bool(__pred(*__first, __value)))
372 	++__first;
373       return __first == __last;
374     }
375 
376   template<typename _ForwardIterator, typename _Tp, typename _Pred>
377     inline bool
378     __check_partitioned_upper(_ForwardIterator __first,
379 			      _ForwardIterator __last, const _Tp& __value,
380 			      _Pred __pred)
381     {
382       while (__first != __last && !bool(__pred(__value, *__first)))
383 	++__first;
384       while (__first != __last && bool(__pred(__value, *__first)))
385 	++__first;
386       return __first == __last;
387     }
388 } // namespace __gnu_debug
389 
390 #endif
391