From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 1984) id 8CF703A14805; Fri, 17 Jul 2020 15:17:15 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 8CF703A14805 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1594999035; bh=FgF4viKdzfSP+l6aA758Ilswcn7uJ/K8te8O+dA+iwU=; h=From:To:Subject:Date:From; b=LH/ubx6fzOk1tkjry6LnPZtIXgLPu3VFFZjZc7q9egW+g55AuCYMp7Bbp3UhNzLGM R6k7k7mO/3zOeKYlhsP/on0hwJba5Rusa79nXYyOWh/WajpEHLGW6CywF9p+nKRu2y N1D2C3oHmzbADjJb3vXiV9SsOrJwZOaPVXDkdi78= Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit From: Tamar Christina To: gcc-cvs@gcc.gnu.org, libstdc++-cvs@gcc.gnu.org Subject: [gcc(refs/vendors/ARM/heads/arm-perf-staging)] libstdc++: Fix common_iterator::operator-> [PR95322] X-Act-Checkin: gcc X-Git-Author: Patrick Palka X-Git-Refname: refs/vendors/ARM/heads/arm-perf-staging X-Git-Oldrev: 50cd4503e59f29e379d0515c48e67d0658ee4562 X-Git-Newrev: fc78e991c35a5ee14efafb4e5566a9570fa31dd4 Message-Id: <20200717151715.8CF703A14805@sourceware.org> Date: Fri, 17 Jul 2020 15:17:15 +0000 (GMT) X-BeenThere: libstdc++-cvs@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libstdc++-cvs mailing list List-Unsubscribe: , List-Archive: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 17 Jul 2020 15:17:15 -0000 https://gcc.gnu.org/g:fc78e991c35a5ee14efafb4e5566a9570fa31dd4 commit fc78e991c35a5ee14efafb4e5566a9570fa31dd4 Author: Patrick Palka Date: Tue May 26 16:17:34 2020 -0400 libstdc++: Fix common_iterator::operator-> [PR95322] This patch fixes the definition of common_iterator::operator-> when the underlying iterator's operator* returns a non-reference. The first problem is that the class __detail::_Common_iter_proxy is used unqualified. Fixing that revealed another problem: the class's template friend declaration of common_iterator doesn't match up with the definition of common_iterator, because the friend declaration isn't constrained. If we try to make the friend declaration match up by adding constraints, we run into frontend bug PR93467. So we currently can't correctly express this friend relation between __detail::_Common_iter_proxy and common_iterator. As a workaround to this frontend bug, this patch moves the definition of _Common_iter_proxy into the class template of common_iterator so that we could instead express the friend relation via the injected-class-name. (This bug was found when attempting to use views::common to work around the compile failure with the testcase in PR95322.) libstdc++-v3/ChangeLog: PR libstdc++/95322 * include/bits/stl_iterator.h (__detail::_Common_iter_proxy): Remove and instead define it ... (common_iterator::_Proxy): ... here. (common_iterator::operator->): Use it. * testsuite/24_iterators/common_iterator/2.cc: New test. * testsuite/std/ranges/adaptors/95322.cc: New test. (cherry picked from commit 3bf5e7657b752cc2352778e8c20ac9cdddca4f93) Diff: --- libstdc++-v3/include/bits/stl_iterator.h | 34 ++++++------ .../testsuite/24_iterators/common_iterator/2.cc | 63 ++++++++++++++++++++++ .../testsuite/std/ranges/adaptors/95322.cc | 50 +++++++++++++++++ 3 files changed, 129 insertions(+), 18 deletions(-) diff --git a/libstdc++-v3/include/bits/stl_iterator.h b/libstdc++-v3/include/bits/stl_iterator.h index fdb1121f823..19b1d53f781 100644 --- a/libstdc++-v3/include/bits/stl_iterator.h +++ b/libstdc++-v3/include/bits/stl_iterator.h @@ -1568,23 +1568,6 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION namespace __detail { - template - class _Common_iter_proxy - { - iter_value_t<_It> _M_keep; - - _Common_iter_proxy(iter_reference_t<_It>&& __x) - : _M_keep(std::move(__x)) { } - - template - friend class common_iterator; - - public: - const iter_value_t<_It>* - operator->() const - { return std::__addressof(_M_keep); } - }; - template concept __common_iter_has_arrow = indirectly_readable && (requires(const _It& __it) { __it.operator->(); } @@ -1613,6 +1596,21 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION _S_noexcept() { return _S_noexcept1<_It, _It2>() && _S_noexcept1<_Sent, _Sent2>(); } + class _Proxy + { + iter_value_t<_It> _M_keep; + + _Proxy(iter_reference_t<_It>&& __x) + : _M_keep(std::move(__x)) { } + + friend class common_iterator; + + public: + const iter_value_t<_It>* + operator->() const + { return std::__addressof(_M_keep); } + }; + public: constexpr common_iterator() @@ -1769,7 +1767,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION return std::__addressof(__tmp); } else - return _Common_iter_proxy(*_M_it); + return _Proxy{*_M_it}; } common_iterator& diff --git a/libstdc++-v3/testsuite/24_iterators/common_iterator/2.cc b/libstdc++-v3/testsuite/24_iterators/common_iterator/2.cc new file mode 100644 index 00000000000..270e8eaa91c --- /dev/null +++ b/libstdc++-v3/testsuite/24_iterators/common_iterator/2.cc @@ -0,0 +1,63 @@ +// Copyright (C) 2020 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-options "-std=gnu++2a" } +// { dg-do run { target c++2a } } + +#include +#include + +struct value { int n; }; + +struct sentinel { int limit; }; + +struct iterator +{ + using iterator_category = std::input_iterator_tag; + using value_type = value; + using difference_type = std::ptrdiff_t; + using reference = value; + + value operator*() const { return value{counter}; } + + iterator& operator++() { ++counter; return *this; } + + iterator operator++(int) { auto i = *this; ++counter; return i; } + + bool operator==(sentinel s) const { return counter == s.limit; } + + int counter = 0; +}; + +void +test01() +{ + iterator i; + sentinel s{2}; + std::common_iterator begin = i, end = s; + VERIFY( begin->n == 0 ); + ++begin; + VERIFY( begin->n == 1 ); + ++begin; + VERIFY( begin == end ); +} + +int +main() +{ + test01(); +} diff --git a/libstdc++-v3/testsuite/std/ranges/adaptors/95322.cc b/libstdc++-v3/testsuite/std/ranges/adaptors/95322.cc new file mode 100644 index 00000000000..44619d6719a --- /dev/null +++ b/libstdc++-v3/testsuite/std/ranges/adaptors/95322.cc @@ -0,0 +1,50 @@ +// Copyright (C) 2020 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-options "-std=gnu++2a" } +// { dg-do run { target c++2a } } + +#include +#include +#include + +namespace ranges = std::ranges; +namespace views = std::views; + +void +test01() +{ + std::list container{1, 2, 3, 4, 5}; + auto v = (container + | views::take(3) + | views::transform(std::negate{}) + | views::common); + auto i = ranges::cbegin(v); + VERIFY( *i == -1 ); + ++i; + VERIFY( *i == -2 ); + ++i; + VERIFY( *i == -3 ); + ++i; + VERIFY( i == ranges::end(v) ); +} + +int +main() +{ + test01(); +}