From 33a1e511b57465d898429740377466894a0b247d Mon Sep 17 00:00:00 2001 From: =?utf8?q?Fran=C3=A7ois=20Dumont?= Date: Thu, 28 Jan 2021 19:00:56 +0100 Subject: [PATCH] libstdc++: Make deque iterator operator- usable with value-init iterators N3644 implies that operator- can be used on value-init iterators. We now return 0 if both iterators are value initialized. If only one is value initialized we keep the UB by returning the result of a normal computation which is a meaningless value. libstdc++-v3/ChangeLog: PR libstdc++/70303 * include/bits/stl_deque.h (std::deque<>::operator-(iterator, iterator)): Return 0 if both iterators are value-initialized. * testsuite/23_containers/deque/70303.cc: New test. * testsuite/23_containers/vector/70303.cc: New test. --- libstdc++-v3/include/bits/stl_deque.h | 18 +++-- .../testsuite/23_containers/deque/70303.cc | 67 +++++++++++++++++++ .../testsuite/23_containers/vector/70303.cc | 67 +++++++++++++++++++ 3 files changed, 146 insertions(+), 6 deletions(-) create mode 100644 libstdc++-v3/testsuite/23_containers/deque/70303.cc create mode 100644 libstdc++-v3/testsuite/23_containers/vector/70303.cc diff --git a/libstdc++-v3/include/bits/stl_deque.h b/libstdc++-v3/include/bits/stl_deque.h index d41c27717a3..04b70b77621 100644 --- a/libstdc++-v3/include/bits/stl_deque.h +++ b/libstdc++-v3/include/bits/stl_deque.h @@ -352,9 +352,12 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER friend difference_type operator-(const _Self& __x, const _Self& __y) _GLIBCXX_NOEXCEPT { - return difference_type(_S_buffer_size()) - * (__x._M_node - __y._M_node - 1) + (__x._M_cur - __x._M_first) - + (__y._M_last - __y._M_cur); + if (__builtin_expect(__x._M_node || __y._M_node, true)) + return difference_type(_S_buffer_size()) + * (__x._M_node - __y._M_node - 1) + (__x._M_cur - __x._M_first) + + (__y._M_last - __y._M_cur); + + return 0; } // _GLIBCXX_RESOLVE_LIB_DEFECTS @@ -366,9 +369,12 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER operator-(const _Self& __x, const _Deque_iterator<_Tp, _RefR, _PtrR>& __y) _GLIBCXX_NOEXCEPT { - return difference_type(_S_buffer_size()) - * (__x._M_node - __y._M_node - 1) + (__x._M_cur - __x._M_first) - + (__y._M_last - __y._M_cur); + if (__builtin_expect(__x._M_node || __y._M_node, true)) + return difference_type(_S_buffer_size()) + * (__x._M_node - __y._M_node - 1) + (__x._M_cur - __x._M_first) + + (__y._M_last - __y._M_cur); + + return 0; } friend _Self diff --git a/libstdc++-v3/testsuite/23_containers/deque/70303.cc b/libstdc++-v3/testsuite/23_containers/deque/70303.cc new file mode 100644 index 00000000000..e0e63694170 --- /dev/null +++ b/libstdc++-v3/testsuite/23_containers/deque/70303.cc @@ -0,0 +1,67 @@ +// Copyright (C) 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. + +// You should have received a copy of the GNU General Public License along +// with this library; see the file COPYING3. If not see +// . + +// { dg-do run } + +#include +#include + +// PR libstdc++/70303 + +void test01() +{ + typedef typename std::deque::iterator It; + It it = It(); + VERIFY(it == it); + VERIFY(!(it != it)); + VERIFY(it - it == 0); + VERIFY(!(it < it)); + VERIFY(!(it > it)); + VERIFY(it <= it); + VERIFY(it >= it); + + typedef typename std::deque::const_iterator CIt; + CIt cit = CIt(); + VERIFY(cit == cit); + VERIFY(!(cit != cit)); + VERIFY(cit - cit == 0); + VERIFY(!(cit < cit)); + VERIFY(!(cit > cit)); + VERIFY(cit <= cit); + VERIFY(cit >= cit); + + VERIFY(it == cit); + VERIFY(!(it != cit)); + VERIFY(cit == it); + VERIFY(!(cit != it)); + VERIFY(it - cit == 0); + VERIFY(cit - it == 0); + VERIFY(!(it < cit)); + VERIFY(!(it > cit)); + VERIFY(it <= cit); + VERIFY(it >= cit); + VERIFY(!(cit < it)); + VERIFY(!(cit > it)); + VERIFY(cit <= it); + VERIFY(cit >= it); +} + +int main() +{ + test01(); + return 0; +} diff --git a/libstdc++-v3/testsuite/23_containers/vector/70303.cc b/libstdc++-v3/testsuite/23_containers/vector/70303.cc new file mode 100644 index 00000000000..af18a0503d8 --- /dev/null +++ b/libstdc++-v3/testsuite/23_containers/vector/70303.cc @@ -0,0 +1,67 @@ +// Copyright (C) 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. + +// You should have received a copy of the GNU General Public License along +// with this library; see the file COPYING3. If not see +// . + +// { dg-do run } + +#include +#include + +// PR libstdc++/70303 + +void test01() +{ + typedef typename std::vector::iterator It; + It it = It(); + VERIFY(it == it); + VERIFY(!(it != it)); + VERIFY(it - it == 0); + VERIFY(!(it < it)); + VERIFY(!(it > it)); + VERIFY(it <= it); + VERIFY(it >= it); + + typedef typename std::vector::const_iterator CIt; + CIt cit = CIt(); + VERIFY(cit == cit); + VERIFY(!(cit != cit)); + VERIFY(cit - cit == 0); + VERIFY(!(cit < cit)); + VERIFY(!(cit > cit)); + VERIFY(cit <= cit); + VERIFY(cit >= cit); + + VERIFY(it == cit); + VERIFY(!(it != cit)); + VERIFY(cit == it); + VERIFY(!(cit != it)); + VERIFY(it - cit == 0); + VERIFY(cit - it == 0); + VERIFY(!(it < cit)); + VERIFY(!(it > cit)); + VERIFY(it <= cit); + VERIFY(it >= cit); + VERIFY(!(cit < it)); + VERIFY(!(cit > it)); + VERIFY(cit <= it); + VERIFY(cit >= it); +} + +int main() +{ + test01(); + return 0; +} -- 2.30.2