Edit File: safe_local_iterator.h
// Safe iterator implementation -*- C++ -*- // Copyright (C) 2011-2018 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/safe_local_iterator.h * This file is a GNU debug extension to the Standard C++ Library. */ #ifndef _GLIBCXX_DEBUG_SAFE_LOCAL_ITERATOR_H #define _GLIBCXX_DEBUG_SAFE_LOCAL_ITERATOR_H 1 #include <debug/safe_unordered_base.h> namespace __gnu_debug { /** \brief Safe iterator wrapper. * * The class template %_Safe_local_iterator is a wrapper around an * iterator that tracks the iterator's movement among sequences and * checks that operations performed on the "safe" iterator are * legal. In additional to the basic iterator operations (which are * validated, and then passed to the underlying iterator), * %_Safe_local_iterator has member functions for iterator invalidation, * attaching/detaching the iterator from sequences, and querying * the iterator's state. */ template<typename _Iterator, typename _Sequence> class _Safe_local_iterator : private _Iterator , public _Safe_local_iterator_base { typedef _Iterator _Iter_base; typedef _Safe_local_iterator_base _Safe_base; typedef typename _Sequence::const_local_iterator _Const_local_iterator; typedef typename _Sequence::size_type size_type; /// Determine if this is a constant iterator. bool _M_constant() const { return std::__are_same<_Const_local_iterator, _Safe_local_iterator>::__value; } typedef std::iterator_traits<_Iterator> _Traits; struct _Attach_single { }; _Safe_local_iterator(const _Iterator& __i, _Safe_sequence_base* __cont, _Attach_single) noexcept : _Iter_base(__i) { _M_attach_single(__cont); } public: typedef _Iterator iterator_type; typedef typename _Traits::iterator_category iterator_category; typedef typename _Traits::value_type value_type; typedef typename _Traits::difference_type difference_type; typedef typename _Traits::reference reference; typedef typename _Traits::pointer pointer; /// @post the iterator is singular and unattached _Safe_local_iterator() noexcept : _Iter_base() { } /** * @brief Safe iterator construction from an unsafe iterator and * its sequence. * * @pre @p seq is not NULL * @post this is not singular */ _Safe_local_iterator(const _Iterator& __i, const _Safe_sequence_base* __cont) : _Iter_base(__i), _Safe_base(__cont, _M_constant()) { _GLIBCXX_DEBUG_VERIFY(!this->_M_singular(), _M_message(__msg_init_singular) ._M_iterator(*this, "this")); } /** * @brief Copy construction. */ _Safe_local_iterator(const _Safe_local_iterator& __x) noexcept : _Iter_base(__x.base()) { // _GLIBCXX_RESOLVE_LIB_DEFECTS // DR 408. Is vector<reverse_iterator<char*> > forbidden? _GLIBCXX_DEBUG_VERIFY(!__x._M_singular() || __x.base() == _Iterator(), _M_message(__msg_init_copy_singular) ._M_iterator(*this, "this") ._M_iterator(__x, "other")); _M_attach(__x._M_sequence); } /** * @brief Move construction. * @post __x is singular and unattached */ _Safe_local_iterator(_Safe_local_iterator&& __x) noexcept : _Iter_base() { _GLIBCXX_DEBUG_VERIFY(!__x._M_singular() || __x.base() == _Iterator(), _M_message(__msg_init_copy_singular) ._M_iterator(*this, "this") ._M_iterator(__x, "other")); auto __cont = __x._M_sequence; __x._M_detach(); std::swap(base(), __x.base()); _M_attach(__cont); } /** * @brief Converting constructor from a mutable iterator to a * constant iterator. */ template<typename _MutableIterator> _Safe_local_iterator( const _Safe_local_iterator<_MutableIterator, typename __gnu_cxx::__enable_if<std::__are_same< _MutableIterator, typename _Sequence::local_iterator::iterator_type>::__value, _Sequence>::__type>& __x) : _Iter_base(__x.base()) { // _GLIBCXX_RESOLVE_LIB_DEFECTS // DR 408. Is vector<reverse_iterator<char*> > forbidden? _GLIBCXX_DEBUG_VERIFY(!__x._M_singular() || __x.base() == _Iterator(), _M_message(__msg_init_const_singular) ._M_iterator(*this, "this") ._M_iterator(__x, "other")); _M_attach(__x._M_sequence); } /** * @brief Copy assignment. */ _Safe_local_iterator& operator=(const _Safe_local_iterator& __x) { // _GLIBCXX_RESOLVE_LIB_DEFECTS // DR 408. Is vector<reverse_iterator<char*> > forbidden? _GLIBCXX_DEBUG_VERIFY(!__x._M_singular() || __x.base() == _Iterator(), _M_message(__msg_copy_singular) ._M_iterator(*this, "this") ._M_iterator(__x, "other")); if (this->_M_sequence && this->_M_sequence == __x._M_sequence) { __gnu_cxx::__scoped_lock __l(this->_M_get_mutex()); base() = __x.base(); _M_version = __x._M_sequence->_M_version; } else { _M_detach(); base() = __x.base(); _M_attach(__x._M_sequence); } return *this; } /** * @brief Move assignment. * @post __x is singular and unattached */ _Safe_local_iterator& operator=(_Safe_local_iterator&& __x) noexcept { _GLIBCXX_DEBUG_VERIFY(this != &__x, _M_message(__msg_self_move_assign) ._M_iterator(*this, "this")); _GLIBCXX_DEBUG_VERIFY(!__x._M_singular() || __x.base() == _Iterator(), _M_message(__msg_copy_singular) ._M_iterator(*this, "this") ._M_iterator(__x, "other")); if (this->_M_sequence && this->_M_sequence == __x._M_sequence) { __gnu_cxx::__scoped_lock __l(this->_M_get_mutex()); base() = __x.base(); _M_version = __x._M_sequence->_M_version; } else { _M_detach(); base() = __x.base(); _M_attach(__x._M_sequence); } __x._M_detach(); __x.base() = _Iterator(); return *this; } /** * @brief Iterator dereference. * @pre iterator is dereferenceable */ reference operator*() const { _GLIBCXX_DEBUG_VERIFY(this->_M_dereferenceable(), _M_message(__msg_bad_deref) ._M_iterator(*this, "this")); return *base(); } /** * @brief Iterator dereference. * @pre iterator is dereferenceable */ pointer operator->() const { _GLIBCXX_DEBUG_VERIFY(this->_M_dereferenceable(), _M_message(__msg_bad_deref) ._M_iterator(*this, "this")); return base().operator->(); } // ------ Input iterator requirements ------ /** * @brief Iterator preincrement * @pre iterator is incrementable */ _Safe_local_iterator& operator++() { _GLIBCXX_DEBUG_VERIFY(this->_M_incrementable(), _M_message(__msg_bad_inc) ._M_iterator(*this, "this")); __gnu_cxx::__scoped_lock __l(this->_M_get_mutex()); ++base(); return *this; } /** * @brief Iterator postincrement * @pre iterator is incrementable */ _Safe_local_iterator operator++(int) { _GLIBCXX_DEBUG_VERIFY(this->_M_incrementable(), _M_message(__msg_bad_inc) ._M_iterator(*this, "this")); __gnu_cxx::__scoped_lock __l(this->_M_get_mutex()); return _Safe_local_iterator(base()++, this->_M_sequence, _Attach_single()); } // ------ Utilities ------ /** * @brief Return the underlying iterator */ _Iterator& base() noexcept { return *this; } const _Iterator& base() const noexcept { return *this; } /** * @brief Return the bucket */ size_type bucket() const { return base()._M_get_bucket(); } /** * @brief Conversion to underlying non-debug iterator to allow * better interaction with non-debug containers. */ operator _Iterator() const { return *this; } /** Attach iterator to the given sequence. */ void _M_attach(_Safe_sequence_base* __seq) { _Safe_base::_M_attach(__seq, _M_constant()); } /** Likewise, but not thread-safe. */ void _M_attach_single(_Safe_sequence_base* __seq) { _Safe_base::_M_attach_single(__seq, _M_constant()); } /// Is the iterator dereferenceable? bool _M_dereferenceable() const { return !this->_M_singular() && !_M_is_end(); } /// Is the iterator incrementable? bool _M_incrementable() const { return !this->_M_singular() && !_M_is_end(); } // Is the iterator range [*this, __rhs) valid? bool _M_valid_range(const _Safe_local_iterator& __rhs, std::pair<difference_type, _Distance_precision>& __dist_info) const; // The sequence this iterator references. typename __gnu_cxx::__conditional_type<std::__are_same<_Const_local_iterator, _Safe_local_iterator>::__value, const _Sequence*, _Sequence*>::__type _M_get_sequence() const { return static_cast<_Sequence*>(_M_sequence); } /// Is this iterator equal to the sequence's begin(bucket) iterator? bool _M_is_begin() const { return base() == _M_get_sequence()->_M_base().begin(bucket()); } /// Is this iterator equal to the sequence's end(bucket) iterator? bool _M_is_end() const { return base() == _M_get_sequence()->_M_base().end(bucket()); } /// Is this iterator part of the same bucket as the other one? template<typename _Other> bool _M_in_same_bucket(const _Safe_local_iterator<_Other, _Sequence>& __other) const { return bucket() == __other.bucket(); } }; template<typename _IteratorL, typename _IteratorR, typename _Sequence> inline bool operator==(const _Safe_local_iterator<_IteratorL, _Sequence>& __lhs, const _Safe_local_iterator<_IteratorR, _Sequence>& __rhs) { _GLIBCXX_DEBUG_VERIFY(!__lhs._M_singular() && !__rhs._M_singular(), _M_message(__msg_iter_compare_bad) ._M_iterator(__lhs, "lhs") ._M_iterator(__rhs, "rhs")); _GLIBCXX_DEBUG_VERIFY(__lhs._M_can_compare(__rhs), _M_message(__msg_compare_different) ._M_iterator(__lhs, "lhs") ._M_iterator(__rhs, "rhs")); _GLIBCXX_DEBUG_VERIFY(__lhs._M_in_same_bucket(__rhs), _M_message(__msg_local_iter_compare_bad) ._M_iterator(__lhs, "lhs") ._M_iterator(__rhs, "rhs")); return __lhs.base() == __rhs.base(); } template<typename _Iterator, typename _Sequence> inline bool operator==(const _Safe_local_iterator<_Iterator, _Sequence>& __lhs, const _Safe_local_iterator<_Iterator, _Sequence>& __rhs) { _GLIBCXX_DEBUG_VERIFY(!__lhs._M_singular() && !__rhs._M_singular(), _M_message(__msg_iter_compare_bad) ._M_iterator(__lhs, "lhs") ._M_iterator(__rhs, "rhs")); _GLIBCXX_DEBUG_VERIFY(__lhs._M_can_compare(__rhs), _M_message(__msg_compare_different) ._M_iterator(__lhs, "lhs") ._M_iterator(__rhs, "rhs")); _GLIBCXX_DEBUG_VERIFY(__lhs._M_in_same_bucket(__rhs), _M_message(__msg_local_iter_compare_bad) ._M_iterator(__lhs, "lhs") ._M_iterator(__rhs, "rhs")); return __lhs.base() == __rhs.base(); } template<typename _IteratorL, typename _IteratorR, typename _Sequence> inline bool operator!=(const _Safe_local_iterator<_IteratorL, _Sequence>& __lhs, const _Safe_local_iterator<_IteratorR, _Sequence>& __rhs) { _GLIBCXX_DEBUG_VERIFY(! __lhs._M_singular() && ! __rhs._M_singular(), _M_message(__msg_iter_compare_bad) ._M_iterator(__lhs, "lhs") ._M_iterator(__rhs, "rhs")); _GLIBCXX_DEBUG_VERIFY(__lhs._M_can_compare(__rhs), _M_message(__msg_compare_different) ._M_iterator(__lhs, "lhs") ._M_iterator(__rhs, "rhs")); _GLIBCXX_DEBUG_VERIFY(__lhs._M_in_same_bucket(__rhs), _M_message(__msg_local_iter_compare_bad) ._M_iterator(__lhs, "lhs") ._M_iterator(__rhs, "rhs")); return __lhs.base() != __rhs.base(); } template<typename _Iterator, typename _Sequence> inline bool operator!=(const _Safe_local_iterator<_Iterator, _Sequence>& __lhs, const _Safe_local_iterator<_Iterator, _Sequence>& __rhs) { _GLIBCXX_DEBUG_VERIFY(!__lhs._M_singular() && !__rhs._M_singular(), _M_message(__msg_iter_compare_bad) ._M_iterator(__lhs, "lhs") ._M_iterator(__rhs, "rhs")); _GLIBCXX_DEBUG_VERIFY(__lhs._M_can_compare(__rhs), _M_message(__msg_compare_different) ._M_iterator(__lhs, "lhs") ._M_iterator(__rhs, "rhs")); _GLIBCXX_DEBUG_VERIFY(__lhs._M_in_same_bucket(__rhs), _M_message(__msg_local_iter_compare_bad) ._M_iterator(__lhs, "lhs") ._M_iterator(__rhs, "rhs")); return __lhs.base() != __rhs.base(); } /** Safe local iterators know if they are dereferenceable. */ template<typename _Iterator, typename _Sequence> inline bool __check_dereferenceable(const _Safe_local_iterator<_Iterator, _Sequence>& __x) { return __x._M_dereferenceable(); } /** Safe local iterators know how to check if they form a valid range. */ template<typename _Iterator, typename _Sequence> inline bool __valid_range(const _Safe_local_iterator<_Iterator, _Sequence>& __first, const _Safe_local_iterator<_Iterator, _Sequence>& __last, typename _Distance_traits<_Iterator>::__type& __dist_info) { return __first._M_valid_range(__last, __dist_info); } /** Safe local iterators need a special method to get distance between each other. */ template<typename _Iterator, typename _Sequence> inline std::pair<typename std::iterator_traits<_Iterator>::difference_type, _Distance_precision> __get_distance(const _Safe_local_iterator<_Iterator, _Sequence>& __first, const _Safe_local_iterator<_Iterator, _Sequence>& __last, std::input_iterator_tag) { if (__first.base() == __last.base()) return { 0, __dp_exact }; if (__first._M_is_begin()) { if (__last._M_is_end()) return { __first._M_get_sequence()->bucket_size(__first.bucket()), __dp_exact }; return { 1, __dp_sign }; } if (__first._M_is_end()) { if (__last._M_is_begin()) return { -__first._M_get_sequence()->bucket_size(__first.bucket()), __dp_exact }; return { -1, __dp_sign }; } if (__last._M_is_begin()) return { -1, __dp_sign }; if (__last._M_is_end()) return { 1, __dp_sign }; return { 1, __dp_equality }; } #if __cplusplus < 201103L template<typename _Iterator, typename _Sequence> struct _Unsafe_type<_Safe_local_iterator<_Iterator, _Sequence> > { typedef _Iterator _Type; }; #endif template<typename _Iterator, typename _Sequence> inline _Iterator __unsafe(const _Safe_local_iterator<_Iterator, _Sequence>& __it) { return __it.base(); } } // namespace __gnu_debug #include <debug/safe_local_iterator.tcc> #endif
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