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gcc/libstdc++-v3/include/debug/safe_local_iterator.h

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// Safe iterator implementation -*- C++ -*-
// Copyright (C) 2011-2017 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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