From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id 3271C385800B; Wed, 20 Oct 2021 03:20:06 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 3271C385800B From: "unlvsur at live dot com" To: gcc-bugs@gcc.gnu.org Subject: [Bug libstdc++/100017] [11/12 regression] error: 'fenv_t' has not been declared in '::' -- canadian compilation fails Date: Wed, 20 Oct 2021 03:20:06 +0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: libstdc++ X-Bugzilla-Version: 11.0 X-Bugzilla-Keywords: build X-Bugzilla-Severity: normal X-Bugzilla-Who: unlvsur at live dot com X-Bugzilla-Status: NEW X-Bugzilla-Resolution: X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org X-Bugzilla-Target-Milestone: 11.3 X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: 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: Wed, 20 Oct 2021 03:20:07 -0000 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D100017 --- Comment #28 from cqwrteur --- (In reply to Ofer Shinaar from comment #27) > (In reply to cqwrteur from comment #23) > > (In reply to Jonathan Wakely from comment #22) > > > *** Bug 101060 has been marked as a duplicate of this bug. *** > >=20 > > I can confirm Yujie Yang's patch works. Just add -nostdinc++ to configu= re > > and configure.ac in gcc root repository (not in gcc subdirectory nor > > libstdc++-v3 subdirectory) > >=20 > > Yes. So it is very easy to fix. >=20 > and what if I do want to use libstdc++ ? the first soultion allows me that no. it does not affect how libstdc++ builds. It is a bug in the build proce= ss that the GCC will prefer finding headers in the C++ cross compiler. It shou= ld not use C++ standard library headers in your cross compiler. Add -nostdinc++ is adding a toggle at the build process that fixes all sort= s of issues that relate to the build of libstdc++. It won't affect you for using it after the build. There are some other problems of Canadian compilation here, like copying wr= ong DLLs when you build with multilibs. Those are separate issues.=