From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by sourceware.org (Postfix) with ESMTPS id 945553858416 for ; Fri, 4 Feb 2022 23:57:35 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 945553858416 Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-324-8sc8UBQ2NiGqsrOuuYIxTw-1; Fri, 04 Feb 2022 18:57:34 -0500 X-MC-Unique: 8sc8UBQ2NiGqsrOuuYIxTw-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 36FC9100C662; Fri, 4 Feb 2022 23:57:33 +0000 (UTC) Received: from localhost (unknown [10.33.37.88]) by smtp.corp.redhat.com (Postfix) with ESMTP id DCC5188FE; Fri, 4 Feb 2022 23:57:32 +0000 (UTC) From: Jonathan Wakely To: libstdc++@gcc.gnu.org, gcc-patches@gcc.gnu.org Subject: [committed] libstdc++: Allow Clang to use before C++23 Date: Fri, 4 Feb 2022 23:57:32 +0000 Message-Id: <20220204235732.2711119-1-jwakely@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset="US-ASCII" X-Spam-Status: No, score=-13.3 required=5.0 tests=BAYES_00, DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, GIT_PATCH_0, KAM_NUMSUBJECT, RCVD_IN_DNSWL_LOW, SPF_HELO_NONE, SPF_NONE, TXREP, T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on server2.sourceware.org X-BeenThere: libstdc++@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libstdc++ mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 04 Feb 2022 23:57:36 -0000 Tested powerpc64le-linux (and smoke tested with clang), pushed to trunk. There is code that only expects to be compiled with clang++ and uses its , which works because Clang supports the _Atomic specifier in C++. The addition of to libstdc++ broke this code, as now it finds the C++ header instead, which is empty for any standard mode before C++23. This change allows that code to keep working as before, by forwarding to clang's . libstdc++-v3/ChangeLog: * include/c_compatibility/stdatomic.h [__clang__]: Use #include_next . --- libstdc++-v3/include/c_compatibility/stdatomic.h | 2 ++ 1 file changed, 2 insertions(+) diff --git a/libstdc++-v3/include/c_compatibility/stdatomic.h b/libstdc++-v3/include/c_compatibility/stdatomic.h index 852574bd87c..95c72615b4e 100644 --- a/libstdc++-v3/include/c_compatibility/stdatomic.h +++ b/libstdc++-v3/include/c_compatibility/stdatomic.h @@ -120,5 +120,7 @@ using std::atomic_flag_clear_explicit; using std::atomic_thread_fence; using std::atomic_signal_fence; +#elif defined __clang__ +# include_next #endif // C++23 #endif // _GLIBCXX_STDATOMIC_H -- 2.34.1