diff options
Diffstat (limited to 'gdb/common')
| -rw-r--r-- | gdb/common/filtered-iterator.h | 87 | ||||
| -rw-r--r-- | gdb/common/safe-iterator.h | 93 |
2 files changed, 180 insertions, 0 deletions
diff --git a/gdb/common/filtered-iterator.h b/gdb/common/filtered-iterator.h new file mode 100644 index 0000000..fe1c20b --- /dev/null +++ b/gdb/common/filtered-iterator.h @@ -0,0 +1,87 @@ +/* A forward filtered iterator for GDB, the GNU debugger. + Copyright (C) 2018 Free Software Foundation, Inc. + + This file is part of GDB. + + This program 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 of the License, or + (at your option) any later version. + + This program 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. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. */ + +#ifndef FILTERED_ITERATOR_H +#define FILTERED_ITERATOR_H + +/* A filtered iterator. This wraps BaseIterator and automatically + skips elements that FilterFunc filters out. Requires that + default-constructing a BaseIterator creates a valid one-past-end + iterator. */ + +template<typename BaseIterator, typename FilterFunc> +class filtered_iterator +{ +public: + typedef filtered_iterator self_type; + typedef typename BaseIterator::value_type value_type; + typedef typename BaseIterator::reference reference; + typedef typename BaseIterator::pointer pointer; + typedef typename BaseIterator::iterator_category iterator_category; + typedef typename BaseIterator::difference_type difference_type; + + /* Construct by forwarding all arguments to the underlying + iterator. */ + template<typename... Args> + explicit filtered_iterator (Args &&...args) + : m_it (std::forward<Args> (args)...) + { skip_filtered (); } + + /* Create a one-past-end iterator. */ + filtered_iterator () = default; + + /* Need these as the variadic constructor would be a better match + otherwise. */ + filtered_iterator (filtered_iterator &) = default; + filtered_iterator (const filtered_iterator &) = default; + filtered_iterator (filtered_iterator &&) = default; + filtered_iterator (const filtered_iterator &&other) + : filtered_iterator (static_cast<const filtered_iterator &> (other)) + {} + + value_type operator* () const { return *m_it; } + + self_type &operator++ () + { + ++m_it; + skip_filtered (); + return *this; + } + + bool operator== (const self_type &other) const + { return *m_it == *other.m_it; } + + bool operator!= (const self_type &other) const + { return *m_it != *other.m_it; } + +private: + + void skip_filtered () + { + for (; m_it != m_end; ++m_it) + if (m_filter (*m_it)) + break; + } + +private: + FilterFunc m_filter {}; + BaseIterator m_it {}; + BaseIterator m_end {}; +}; + +#endif /* FILTERED_ITERATOR_H */ diff --git a/gdb/common/safe-iterator.h b/gdb/common/safe-iterator.h new file mode 100644 index 0000000..4210766 --- /dev/null +++ b/gdb/common/safe-iterator.h @@ -0,0 +1,93 @@ +/* A safe iterator for GDB, the GNU debugger. + Copyright (C) 2018 Free Software Foundation, Inc. + + This file is part of GDB. + + This program 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 of the License, or + (at your option) any later version. + + This program 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. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. */ + +#ifndef SAFE_ITERATOR_H +#define SAFE_ITERATOR_H + +/* A forward iterator that wraps Iterator, such that when iterating + with iterator IT, it is possible to delete *IT without invalidating + IT. Suitably wrapped in a range type and used with range-for, this + allow convenient patterns like this: + + // range_safe() returns a range type whose begin()/end() methods + // return safe iterators. + for (foo *f : range_safe ()) + { + if (f->should_delete ()) + { + // The ++it operation implicitly done by the range-for is + // still OK after this. + delete f; + } + } +*/ + +template<typename Iterator> +class basic_safe_iterator +{ +public: + typedef basic_safe_iterator self_type; + typedef typename Iterator::value_type value_type; + typedef typename Iterator::reference reference; + typedef typename Iterator::pointer pointer; + typedef typename Iterator::iterator_category iterator_category; + typedef typename Iterator::difference_type difference_type; + + /* Construct by forwarding all arguments to the underlying + iterator. */ + template<typename... Args> + explicit basic_safe_iterator (Args &&...args) + : m_it (std::forward<Args> (args)...), + m_next (m_it) + { + if (m_it != m_end) + ++m_next; + } + + /* Create a one-past-end iterator. */ + basic_safe_iterator () + {} + + value_type operator* () const { return *m_it; } + + self_type &operator++ () + { + m_it = m_next; + if (m_it != m_end) + ++m_next; + return *this; + } + + bool operator== (const self_type &other) const + { return m_it == other.m_it; } + + bool operator!= (const self_type &other) const + { return m_it != other.m_it; } + +private: + /* The current element. */ + Iterator m_it {}; + + /* The next element. Always one element ahead of M_IT. */ + Iterator m_next {}; + + /* A one-past-end iterator. */ + Iterator m_end {}; +}; + +#endif /* SAFE_ITERATOR_H */ |