From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 32179 invoked by alias); 14 Dec 2011 00:57:12 -0000 Received: (qmail 32171 invoked by uid 22791); 14 Dec 2011 00:57:12 -0000 X-SWARE-Spam-Status: No, hits=-2.8 required=5.0 tests=ALL_TRUSTED,AWL,BAYES_00,TW_CX X-Spam-Check-By: sourceware.org Received: from localhost (HELO gcc.gnu.org) (127.0.0.1) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Wed, 14 Dec 2011 00:56:59 +0000 From: "matt at use dot net" To: gcc-bugs@gcc.gnu.org Subject: [Bug middle-end/51544] New: uninitialized variable false positive prevents bootstrap at -O3 Date: Wed, 14 Dec 2011 00:58:00 -0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: new X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: middle-end X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: matt at use dot net X-Bugzilla-Status: UNCONFIRMED X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org X-Bugzilla-Target-Milestone: --- X-Bugzilla-Changed-Fields: Message-ID: X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/ Auto-Submitted: auto-generated Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Mailing-List: contact gcc-bugs-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-bugs-owner@gcc.gnu.org X-SW-Source: 2011-12/txt/msg01446.txt.bz2 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D51544 Bug #: 51544 Summary: uninitialized variable false positive prevents bootstrap at -O3 Classification: Unclassified Product: gcc Version: 4.7.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: middle-end AssignedTo: unassigned@gcc.gnu.org ReportedBy: matt@use.net I checked by hand, and this looks like a false positive to me. It doesn't c= ome up without -O[3,fast]. NOTE: I have hand-modified my build/bootstrap-lto.mk to use -Ofast. It's possible that using the bootstrap-O3 build-config will reproduce it as well. $ ~/src/gcc-trunk/configure --enable-bootstrap --prefix=3D/home/matt --enable-clocale=3Dgnu --with-system-zlib --with-demangler-in-ld --enable-l= to --with-fpmath=3Dsse --enable-languages=3Dc,c++,lto --with-build-config=3Dbootstrap-lto --enable-build-with-cxx --disable-libmu= dflap --with-cpu=3Dcore2 --with-tune=3Dcore2 --disable-libssp $ make -j7 profiledbootstrap /home/matt/src/gcc-trunk/gcc/cp/parser.c: In function =E2=80=98bool cp_parser_ctor_initializer_opt_and_function_body(cp_parser*)=E2=80=99: /home/matt/src/gcc-trunk/gcc/cp/parser.c:17533:43: error: =E2=80=98list=E2= =80=99 may be used uninitialized in this function [-Werror=3Dmaybe-uninitialized]