gcc/libstdc++-v3/include/debug/stl_iterator.h
François Dumont cc79682046 libstdc++: [_GLIBCXX_DEBUG] Fix management of __dp_sign_max_size [PR 99402]
__dp_sign precision indicates that we found out what iterator comes first or
last in the range. __dp_sign_max_size is the same plus it gives the information
of the max size of the range that is to say the max_size value such that
distance(lhs, rhs) < max_size.
Thanks to this additional information we are able to tell when a copy of n elements
to that range will fail even if we do not know exactly how large it is.

This patch makes sure that we are properly using this information.

libstdc++-v3/ChangeLog:

	PR libstdc++/99402
	* include/debug/helper_functions.h (__can_advance(_InputIterator,
	const std::pair<_Diff, _Distance_precision>&, int)): New.
	(__can_advance(const _Safe_iterator<>&,
	const std::pair<_Diff, _Distance_precision>&, int)): New.
	* include/debug/macros.h (__glibcxx_check_can_increment_dist): New,
	use latter.
	(__glibcxx_check_can_increment_range): Adapt to use latter.
	(__glibcxx_check_can_decrement_range): Likewise.
	* include/debug/safe_iterator.h
	(_Safe_iterator<>::_M_can_advance(const std::pair<_Diff, _Distance_precision>&,
	int)): New.
	(__can_advance(const _Safe_iterator<>&,
	const std::pair<_Diff, _Distance_precision>&, int)): New.
	* include/debug/safe_iterator.tcc
	(_Safe_iterator<>::_M_can_advance(const std::pair<_Diff, _Distance_precision>&,
	int)): New.
	(_Safe_iterator<>::_M_valid_range(const _Safe_iterator<>&,
	std::pair<difference_type, _Distance_precision>&, bool)): Adapt for
	__dp_sign_max_size.
	(__copy_move_a): Adapt to use __glibcxx_check_can_increment_dist.
	(__copy_move_backward_a): Likewise.
	(__equal_aux): Likewise.
	* include/debug/stl_iterator.h (__can_advance(const std::reverse_iterator<>&,
	const std::pair<_Diff, _Distance_precision>&, int)): New.
	(__can_advance(const std::move_iterator<>&,
	const std::pair<_Diff, _Distance_precision>&, int)): New.
	* testsuite/25_algorithms/copy/debug/99402.cc: New test.
2021-04-09 21:46:35 +02:00

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// Debugging support implementation -*- C++ -*-
// Copyright (C) 2015-2021 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library. This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 3, or (at your option)
// any later version.
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// Under Section 7 of GPL version 3, you are granted additional
// permissions described in the GCC Runtime Library Exception, version
// 3.1, as published by the Free Software Foundation.
// You should have received a copy of the GNU General Public License and
// a copy of the GCC Runtime Library Exception along with this program;
// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
// <http://www.gnu.org/licenses/>.
/** @file debug/stl_iterator.h
* This file is a GNU debug extension to the Standard C++ Library.
*/
#ifndef _GLIBCXX_DEBUG_STL_ITERATOR_H
#define _GLIBCXX_DEBUG_STL_ITERATOR_H 1
#include <debug/helper_functions.h>
namespace __gnu_debug
{
// Help Debug mode to see through reverse_iterator.
template<typename _Iterator>
inline bool
__valid_range(const std::reverse_iterator<_Iterator>& __first,
const std::reverse_iterator<_Iterator>& __last,
typename _Distance_traits<_Iterator>::__type& __dist)
{ return __valid_range(__last.base(), __first.base(), __dist); }
template<typename _Iterator>
inline typename _Distance_traits<_Iterator>::__type
__get_distance(const std::reverse_iterator<_Iterator>& __first,
const std::reverse_iterator<_Iterator>& __last)
{ return __get_distance(__last.base(), __first.base()); }
template<typename _Iterator, typename _Size>
inline bool
__can_advance(const std::reverse_iterator<_Iterator>& __it, _Size __n)
{ return __can_advance(__it.base(), -__n); }
template<typename _Iterator, typename _Diff>
inline bool
__can_advance(const std::reverse_iterator<_Iterator>& __it,
const std::pair<_Diff, _Distance_precision>& __dist,
int __way)
{ return __can_advance(__it.base(), __dist, -__way); }
template<typename _Iterator, typename _Sequence>
inline std::reverse_iterator<_Iterator>
__base(const std::reverse_iterator<_Safe_iterator<
_Iterator, _Sequence, std::random_access_iterator_tag> >& __it)
{ return std::reverse_iterator<_Iterator>(__it.base().base()); }
#if __cplusplus < 201103L
template<typename _Iterator>
struct _Unsafe_type<std::reverse_iterator<_Iterator> >
{
typedef typename _Unsafe_type<_Iterator>::_Type _UnsafeType;
typedef std::reverse_iterator<_UnsafeType> _Type;
};
template<typename _Iterator>
inline std::reverse_iterator<typename _Unsafe_type<_Iterator>::_Type>
__unsafe(const std::reverse_iterator<_Iterator>& __it)
{
typedef typename _Unsafe_type<_Iterator>::_Type _UnsafeType;
return std::reverse_iterator<_UnsafeType>(__unsafe(__it.base()));
}
#else
template<typename _Iterator>
inline auto
__unsafe(const std::reverse_iterator<_Iterator>& __it)
-> decltype(std::__make_reverse_iterator(__unsafe(__it.base())))
{ return std::__make_reverse_iterator(__unsafe(__it.base())); }
#endif
#if __cplusplus >= 201103L
// Help Debug mode to see through move_iterator.
template<typename _Iterator>
inline bool
__valid_range(const std::move_iterator<_Iterator>& __first,
const std::move_iterator<_Iterator>& __last,
typename _Distance_traits<_Iterator>::__type& __dist)
{ return __valid_range(__first.base(), __last.base(), __dist); }
template<typename _Iterator>
inline typename _Distance_traits<_Iterator>::__type
__get_distance(const std::move_iterator<_Iterator>& __first,
const std::move_iterator<_Iterator>& __last)
{ return __get_distance(__first.base(), __last.base()); }
template<typename _Iterator, typename _Size>
inline bool
__can_advance(const std::move_iterator<_Iterator>& __it, _Size __n)
{ return __can_advance(__it.base(), __n); }
template<typename _Iterator, typename _Diff>
inline bool
__can_advance(const std::move_iterator<_Iterator>& __it,
const std::pair<_Diff, _Distance_precision>& __dist,
int __way)
{ return __can_advance(__it.base(), __dist, __way); }
template<typename _Iterator>
inline auto
__unsafe(const std::move_iterator<_Iterator>& __it)
-> decltype(std::make_move_iterator(__unsafe(__it.base())))
{ return std::make_move_iterator(__unsafe(__it.base())); }
template<typename _Iterator>
inline auto
__base(const std::move_iterator<_Iterator>& __it)
-> decltype(std::make_move_iterator(__base(__it.base())))
{ return std::make_move_iterator(__base(__it.base())); }
#endif
}
#endif