From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 2181) id 31CAC3890420; Thu, 17 Dec 2020 14:03:42 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 31CAC3890420 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="utf-8" From: Jonathan Wakely To: gcc-cvs@gcc.gnu.org, libstdc++-cvs@gcc.gnu.org Subject: [gcc r11-6229] libstdc++: Fix -Wunused warning X-Act-Checkin: gcc X-Git-Author: Jonathan Wakely X-Git-Refname: refs/heads/master X-Git-Oldrev: 8dc63f13f03facc49b777195c9068432477b5dcd X-Git-Newrev: 9f9dbc8e09cf48406aa24b6c78735f1a7912cc4e Message-Id: <20201217140342.31CAC3890420@sourceware.org> Date: Thu, 17 Dec 2020 14:03:42 +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: Thu, 17 Dec 2020 14:03:42 -0000 https://gcc.gnu.org/g:9f9dbc8e09cf48406aa24b6c78735f1a7912cc4e commit r11-6229-g9f9dbc8e09cf48406aa24b6c78735f1a7912cc4e Author: Jonathan Wakely Date: Thu Dec 17 13:16:02 2020 +0000 libstdc++: Fix -Wunused warning As noted in PR 66146 comment 35, there is a new warning in the new std::call_once implementation. libstdc++-v3/ChangeLog: * src/c++11/mutex.cc (std::once_flag::_M_finish): Add maybe_unused attribute to variable used in assertion. Diff: --- libstdc++-v3/src/c++11/mutex.cc | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/libstdc++-v3/src/c++11/mutex.cc b/libstdc++-v3/src/c++11/mutex.cc index 4d42bed8ecc..93a5eae391d 100644 --- a/libstdc++-v3/src/c++11/mutex.cc +++ b/libstdc++-v3/src/c++11/mutex.cc @@ -74,7 +74,8 @@ std::once_flag::_M_finish(bool returning) noexcept } else { - int prev = __atomic_exchange_n(&_M_once, newval, __ATOMIC_RELEASE); + int prev [[maybe_unused]] + = __atomic_exchange_n(&_M_once, newval, __ATOMIC_RELEASE); __glibcxx_assert(prev & _Bits::_Active); // Wake any other threads waiting for this execution to finish. constexpr int futex_wake = 129; // FUTEX_WAKE_PRIVATE