From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id 56E183857405; Thu, 12 May 2022 16:49:36 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 56E183857405 From: "unlvsur at live dot com" To: gcc-bugs@gcc.gnu.org Subject: [Bug c++/105584] New: libcxx needs using_if_exist attribute Date: Thu, 12 May 2022 16:49:36 +0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: new X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: c++ X-Bugzilla-Version: 13.0 X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: unlvsur at live dot com X-Bugzilla-Status: UNCONFIRMED X-Bugzilla-Resolution: X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org X-Bugzilla-Target-Milestone: --- X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: bug_id short_desc product version bug_status bug_severity priority component assigned_to reporter target_milestone Message-ID: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-BeenThere: gcc-bugs@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc-bugs mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 12 May 2022 16:49:36 -0000 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D105584 Bug ID: 105584 Summary: libcxx needs using_if_exist attribute Product: gcc Version: 13.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ Assignee: unassigned at gcc dot gnu.org Reporter: unlvsur at live dot com Target Milestone: --- https://github.com/llvm/llvm-project/blob/14e83ada16b3944a4431617ed4ce7088f= 7f7cd9a/libcxx/include/__config#L772 #if __has_attribute(using_if_exists) # define _LIBCPP_USING_IF_EXISTS __attribute__((using_if_exists)) #else # define _LIBCPP_USING_IF_EXISTS #endif libcxx recently switches a lot of C usings with the new using_if_exists attribute in clang, but GCC does not support it, causing compilation to fai= l if these global definitions do not exist. /home/cqwrteur/toolchains/native/x86_64-w64-mingw32/x86_64-w64-mingw32/incl= ude/c++/v1/cstdlib:139:9: error: 'aligned_alloc' has not been declared in '::' 139 | using ::aligned_alloc _LIBCPP_USING_IF_EXISTS; | ^~~~~~~~~~~~~ /home/cqwrteur/toolchains/native/x86_64-w64-mingw32/x86_64-w64-mingw32/incl= ude/c++/v1/ctime:75:9: error: 'timespec_get' has not been declared in '::' 75 | using ::timespec_get _LIBCPP_USING_IF_EXISTS; | ^~~~~~~~~~~~ I think GCC should add this attribute to support libcxx correctly.=