From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([209.51.188.92]:48099) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gyYfw-0000HD-9O for qemu-devel@nongnu.org; Tue, 26 Feb 2019 04:05:21 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gyYfr-0000HY-Pz for qemu-devel@nongnu.org; Tue, 26 Feb 2019 04:05:17 -0500 Received: from mx1.redhat.com ([209.132.183.28]:35290) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gyYfp-0000Dx-QD for qemu-devel@nongnu.org; Tue, 26 Feb 2019 04:05:14 -0500 References: <201902230335.59138.randrianasulu@gmail.com> <201902252029.28990.randrianasulu@gmail.com> <6de6b2df-380a-75dd-b3e9-4197ca4db866@redhat.com> <201902261158.09086.randrianasulu@gmail.com> From: Thomas Huth Message-ID: Date: Tue, 26 Feb 2019 10:05:02 +0100 MIME-Version: 1.0 In-Reply-To: <201902261158.09086.randrianasulu@gmail.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] Build error with git commit 8eb29f1bf5a974dc4c11d2d1f5e7c7f7a62be116 on x86_64 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Andrew Randrianasulu , qemu-devel@nongnu.org On 26/02/2019 09.58, Andrew Randrianasulu wrote: > =D0=92 =D1=81=D0=BE=D0=BE=D0=B1=D1=89=D0=B5=D0=BD=D0=B8=D0=B8 =D0=BE=D1= =82 Tuesday 26 February 2019 11:54:12 =D0=B2=D1=8B =D0=BD=D0=B0=D0=BF=D0=B8= =D1=81=D0=B0=D0=BB=D0=B8: >> On 25/02/2019 18.29, Andrew Randrianasulu wrote: >>> =D0=92 =D1=81=D0=BE=D0=BE=D0=B1=D1=89=D0=B5=D0=BD=D0=B8=D0=B8 =D0=BE=D1= =82 Monday 25 February 2019 19:19:01 Philippe Mathieu-Daudc3a9 >>> >>> =D0=BD=D0=B0=D0=BF=D0=B8=D1=81=D0=B0=D0=BB(=D0=B0): >>>> Hi Andrew, >>>> >>>> On 2/23/19 1:35 AM, Andrew Randrianasulu wrote: >>>>> Hello! >>>>> >>>>> I just pulled latest git >>>> >>>> [...] >>>> >>>>> and default build with simple ./configure on slackware 14.2 x86-64 = box >>>>> failed like this: >>>>> >>>>> root@slax:~/src/qemu# LANG=3DC make -j 5 >>>>> CHK version_gen.h >>>>> CC qobject/block-qdict.o >>>>> CC util/thread-pool.o >>>>> CC util/main-loop.o >>>>> CC util/qemu-timer.o >>>>> CC util/iohandler.o >>>>> CC util/aio-posix.o >>>>> qobject/block-qdict.c: In function 'qdict_array_split': >>>>> qobject/block-qdict.c:259:9: error: 'subqdict' may be used >>>>> uninitialized in this function [-Werror=3Dmaybe-uninitialized] >>>>> qlist_append_obj(*dst, subqobj ?: QOBJECT(subqdict)); >>>>> ^ >>>> >>>> That's odd, I can not reproduce with a simple ./configure: >>>> >>>> $ cat /etc/slackware-version >>>> Slackware 14.2 >>>> >>>> $ gcc --version >>>> gcc (GCC) 5.5.0 >>> >>> Well, then may be this is false positive, right now another qemu inst= ance >>> is busy inside same chroot, will try patch posted in earlier mail (af= ter >>> removing CFLAG I added for compiling qemu at all after this error). >>> >>> Thanks for trying to reproduce. >> >> Just to be sure: You don't compile with -O3 or -O1 or -O0 in the CFLAG= S >> here, do you? >=20 > This time it was -O3, but I got some corruption in ppc64le guest's X, = so I plan=20 > to revert this -O3 back to default .... Ok, then that's the problem here: GCC often produces some additional "may be unused" warnings with -O3, and we normally only guarantee that QEMU compiles without warnings when using the standard -O2 optimization level. So if you want to compile with -O3, you also have to specify --disable-werror (or add -Wno-error=3Dmaybe-unitialized to the CFLAGS). But unless you have really an urgent need for O3, I'd rather recommend to compile with the well-tested O2 optimization level instead. Thomas