| Message ID | 20221207132439.635402-1-eric.auger@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [for,7.2?] target/i386: Remove compilation errors when -Werror=maybe-uninitialized | expand |
On 12/7/22 14:24, Eric Auger wrote: > Initialize r0-3 to avoid compilation errors when > -Werror=maybe-uninitialized is used > > ../target/i386/ops_sse.h: In function ‘helper_vpermdq_ymm’: > ../target/i386/ops_sse.h:2495:13: error: ‘r3’ may be used uninitialized in this function [-Werror=maybe-uninitialized] > 2495 | d->Q(3) = r3; > | ~~~~~~~~^~~~ > ../target/i386/ops_sse.h:2494:13: error: ‘r2’ may be used uninitialized in this function [-Werror=maybe-uninitialized] > 2494 | d->Q(2) = r2; > | ~~~~~~~~^~~~ > ../target/i386/ops_sse.h:2493:13: error: ‘r1’ may be used uninitialized in this function [-Werror=maybe-uninitialized] > 2493 | d->Q(1) = r1; > | ~~~~~~~~^~~~ > ../target/i386/ops_sse.h:2492:13: error: ‘r0’ may be used uninitialized in this function [-Werror=maybe-uninitialized] > 2492 | d->Q(0) = r0; > | ~~~~~~~~^~~~ > > Signed-off-by: Eric Auger <eric.auger@redhat.com> > Fixes: 790684776861 ("target/i386: reimplement 0x0f 0x3a, add AVX") > > --- > > Am I the only one getting this? Or anything wrong in my setup. With Stefan's correct address. Forgive me for the noise. Eric > --- > target/i386/ops_sse.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/target/i386/ops_sse.h b/target/i386/ops_sse.h > index 3cbc36a59d..b77071b8da 100644 > --- a/target/i386/ops_sse.h > +++ b/target/i386/ops_sse.h > @@ -2451,7 +2451,7 @@ void glue(helper_vpgatherqq, SUFFIX)(CPUX86State *env, > #if SHIFT >= 2 > void helper_vpermdq_ymm(Reg *d, Reg *v, Reg *s, uint32_t order) > { > - uint64_t r0, r1, r2, r3; > + uint64_t r0 = 0, r1 = 0, r2 = 0, r3 = 0; > > switch (order & 3) { > case 0:
On Wed, 7 Dec 2022 at 08:31, Eric Auger <eric.auger@redhat.com> wrote: > On 12/7/22 14:24, Eric Auger wrote: > > Initialize r0-3 to avoid compilation errors when > > -Werror=maybe-uninitialized is used > > > > ../target/i386/ops_sse.h: In function ‘helper_vpermdq_ymm’: > > ../target/i386/ops_sse.h:2495:13: error: ‘r3’ may be used uninitialized in this function [-Werror=maybe-uninitialized] > > 2495 | d->Q(3) = r3; > > | ~~~~~~~~^~~~ > > ../target/i386/ops_sse.h:2494:13: error: ‘r2’ may be used uninitialized in this function [-Werror=maybe-uninitialized] > > 2494 | d->Q(2) = r2; > > | ~~~~~~~~^~~~ > > ../target/i386/ops_sse.h:2493:13: error: ‘r1’ may be used uninitialized in this function [-Werror=maybe-uninitialized] > > 2493 | d->Q(1) = r1; > > | ~~~~~~~~^~~~ > > ../target/i386/ops_sse.h:2492:13: error: ‘r0’ may be used uninitialized in this function [-Werror=maybe-uninitialized] > > 2492 | d->Q(0) = r0; > > | ~~~~~~~~^~~~ > > > > Signed-off-by: Eric Auger <eric.auger@redhat.com> > > Fixes: 790684776861 ("target/i386: reimplement 0x0f 0x3a, add AVX") > > > > --- > > > > Am I the only one getting this? Or anything wrong in my setup. > > With Stefan's correct address. Forgive me for the noise. When is -Wmaybe-uninitialized used? QEMU's build system doesn't set it. Unless it's automatically set by meson this must be a manual --extra-cflags= option you set. If you added it manually then let's fix this in 8.0 since it's not tested/supported and very few people will see this issue. Stefan
Hi Stefan, On 12/7/22 15:09, Stefan Hajnoczi wrote: > On Wed, 7 Dec 2022 at 08:31, Eric Auger <eric.auger@redhat.com> wrote: >> On 12/7/22 14:24, Eric Auger wrote: >>> Initialize r0-3 to avoid compilation errors when >>> -Werror=maybe-uninitialized is used >>> >>> ../target/i386/ops_sse.h: In function ‘helper_vpermdq_ymm’: >>> ../target/i386/ops_sse.h:2495:13: error: ‘r3’ may be used uninitialized in this function [-Werror=maybe-uninitialized] >>> 2495 | d->Q(3) = r3; >>> | ~~~~~~~~^~~~ >>> ../target/i386/ops_sse.h:2494:13: error: ‘r2’ may be used uninitialized in this function [-Werror=maybe-uninitialized] >>> 2494 | d->Q(2) = r2; >>> | ~~~~~~~~^~~~ >>> ../target/i386/ops_sse.h:2493:13: error: ‘r1’ may be used uninitialized in this function [-Werror=maybe-uninitialized] >>> 2493 | d->Q(1) = r1; >>> | ~~~~~~~~^~~~ >>> ../target/i386/ops_sse.h:2492:13: error: ‘r0’ may be used uninitialized in this function [-Werror=maybe-uninitialized] >>> 2492 | d->Q(0) = r0; >>> | ~~~~~~~~^~~~ >>> >>> Signed-off-by: Eric Auger <eric.auger@redhat.com> >>> Fixes: 790684776861 ("target/i386: reimplement 0x0f 0x3a, add AVX") >>> >>> --- >>> >>> Am I the only one getting this? Or anything wrong in my setup. >> With Stefan's correct address. Forgive me for the noise. > When is -Wmaybe-uninitialized used? QEMU's build system doesn't set > it. Unless it's automatically set by meson this must be a manual > --extra-cflags= option you set. I am using this configure cmd line: ./configure --prefix=/usr --sysconfdir=/etc --libexecdir=/usr/lib/qemu --target-list=x86_64-softmmu --docdir=/usr/share/doc/qemu --enable-kvm --extra-cflags=-O --enable-trace-backends=log --python=/usr/bin/python3 --extra-cflags=-Wall --extra-cflags=-Wundef --extra-cflags=-Wwrite-strings --extra-cflags=-Wmissing-prototypes --extra-cflags=-fno-strict-aliasing --extra-cflags=-fno-common --extra-cflags=-Werror=type-limits > > If you added it manually then let's fix this in 8.0 since it's not > tested/supported and very few people will see this issue. Thanks Eric > > Stefan >
On Wed, 7 Dec 2022 at 09:34, Eric Auger <eric.auger@redhat.com> wrote: > > Hi Stefan, > > On 12/7/22 15:09, Stefan Hajnoczi wrote: > > On Wed, 7 Dec 2022 at 08:31, Eric Auger <eric.auger@redhat.com> wrote: > >> On 12/7/22 14:24, Eric Auger wrote: > >>> Initialize r0-3 to avoid compilation errors when > >>> -Werror=maybe-uninitialized is used > >>> > >>> ../target/i386/ops_sse.h: In function ‘helper_vpermdq_ymm’: > >>> ../target/i386/ops_sse.h:2495:13: error: ‘r3’ may be used uninitialized in this function [-Werror=maybe-uninitialized] > >>> 2495 | d->Q(3) = r3; > >>> | ~~~~~~~~^~~~ > >>> ../target/i386/ops_sse.h:2494:13: error: ‘r2’ may be used uninitialized in this function [-Werror=maybe-uninitialized] > >>> 2494 | d->Q(2) = r2; > >>> | ~~~~~~~~^~~~ > >>> ../target/i386/ops_sse.h:2493:13: error: ‘r1’ may be used uninitialized in this function [-Werror=maybe-uninitialized] > >>> 2493 | d->Q(1) = r1; > >>> | ~~~~~~~~^~~~ > >>> ../target/i386/ops_sse.h:2492:13: error: ‘r0’ may be used uninitialized in this function [-Werror=maybe-uninitialized] > >>> 2492 | d->Q(0) = r0; > >>> | ~~~~~~~~^~~~ > >>> > >>> Signed-off-by: Eric Auger <eric.auger@redhat.com> > >>> Fixes: 790684776861 ("target/i386: reimplement 0x0f 0x3a, add AVX") > >>> > >>> --- > >>> > >>> Am I the only one getting this? Or anything wrong in my setup. > >> With Stefan's correct address. Forgive me for the noise. > > When is -Wmaybe-uninitialized used? QEMU's build system doesn't set > > it. Unless it's automatically set by meson this must be a manual > > --extra-cflags= option you set. > > I am using this configure cmd line: > > ./configure --prefix=/usr --sysconfdir=/etc --libexecdir=/usr/lib/qemu > --target-list=x86_64-softmmu --docdir=/usr/share/doc/qemu --enable-kvm > --extra-cflags=-O --enable-trace-backends=log --python=/usr/bin/python3 > --extra-cflags=-Wall --extra-cflags=-Wundef > --extra-cflags=-Wwrite-strings --extra-cflags=-Wmissing-prototypes > --extra-cflags=-fno-strict-aliasing --extra-cflags=-fno-common > --extra-cflags=-Werror=type-limits > > > > If you added it manually then let's fix this in 8.0 since it's not > > tested/supported and very few people will see this issue. Did you create the ./configure command-line manually? Do you think other people will hit this? Stefan
Hi Stefan, On 12/7/22 16:55, Stefan Hajnoczi wrote: > On Wed, 7 Dec 2022 at 09:34, Eric Auger <eric.auger@redhat.com> wrote: >> Hi Stefan, >> >> On 12/7/22 15:09, Stefan Hajnoczi wrote: >>> On Wed, 7 Dec 2022 at 08:31, Eric Auger <eric.auger@redhat.com> wrote: >>>> On 12/7/22 14:24, Eric Auger wrote: >>>>> Initialize r0-3 to avoid compilation errors when >>>>> -Werror=maybe-uninitialized is used >>>>> >>>>> ../target/i386/ops_sse.h: In function ‘helper_vpermdq_ymm’: >>>>> ../target/i386/ops_sse.h:2495:13: error: ‘r3’ may be used uninitialized in this function [-Werror=maybe-uninitialized] >>>>> 2495 | d->Q(3) = r3; >>>>> | ~~~~~~~~^~~~ >>>>> ../target/i386/ops_sse.h:2494:13: error: ‘r2’ may be used uninitialized in this function [-Werror=maybe-uninitialized] >>>>> 2494 | d->Q(2) = r2; >>>>> | ~~~~~~~~^~~~ >>>>> ../target/i386/ops_sse.h:2493:13: error: ‘r1’ may be used uninitialized in this function [-Werror=maybe-uninitialized] >>>>> 2493 | d->Q(1) = r1; >>>>> | ~~~~~~~~^~~~ >>>>> ../target/i386/ops_sse.h:2492:13: error: ‘r0’ may be used uninitialized in this function [-Werror=maybe-uninitialized] >>>>> 2492 | d->Q(0) = r0; >>>>> | ~~~~~~~~^~~~ >>>>> >>>>> Signed-off-by: Eric Auger <eric.auger@redhat.com> >>>>> Fixes: 790684776861 ("target/i386: reimplement 0x0f 0x3a, add AVX") >>>>> >>>>> --- >>>>> >>>>> Am I the only one getting this? Or anything wrong in my setup. >>>> With Stefan's correct address. Forgive me for the noise. >>> When is -Wmaybe-uninitialized used? QEMU's build system doesn't set >>> it. Unless it's automatically set by meson this must be a manual >>> --extra-cflags= option you set. >> I am using this configure cmd line: >> >> ./configure --prefix=/usr --sysconfdir=/etc --libexecdir=/usr/lib/qemu >> --target-list=x86_64-softmmu --docdir=/usr/share/doc/qemu --enable-kvm >> --extra-cflags=-O --enable-trace-backends=log --python=/usr/bin/python3 >> --extra-cflags=-Wall --extra-cflags=-Wundef >> --extra-cflags=-Wwrite-strings --extra-cflags=-Wmissing-prototypes >> --extra-cflags=-fno-strict-aliasing --extra-cflags=-fno-common >> --extra-cflags=-Werror=type-limits >>> If you added it manually then let's fix this in 8.0 since it's not >>> tested/supported and very few people will see this issue. > Did you create the ./configure command-line manually? Do you think > other people will hit this? no I did not. I just tried to install a fresh qemu repo and just ran the above configure command. You should be able to reproduce I think. I am actually surprised nobody hit that already. Thanks Eric > > Stefan >
On 7/12/22 15:33, Eric Auger wrote: > On 12/7/22 15:09, Stefan Hajnoczi wrote: >> On Wed, 7 Dec 2022 at 08:31, Eric Auger <eric.auger@redhat.com> wrote: >>> On 12/7/22 14:24, Eric Auger wrote: >>>> Initialize r0-3 to avoid compilation errors when >>>> -Werror=maybe-uninitialized is used >>>> >>>> ../target/i386/ops_sse.h: In function ‘helper_vpermdq_ymm’: >>>> ../target/i386/ops_sse.h:2495:13: error: ‘r3’ may be used uninitialized in this function [-Werror=maybe-uninitialized] >>>> 2495 | d->Q(3) = r3; >>>> | ~~~~~~~~^~~~ >>>> ../target/i386/ops_sse.h:2494:13: error: ‘r2’ may be used uninitialized in this function [-Werror=maybe-uninitialized] >>>> 2494 | d->Q(2) = r2; >>>> | ~~~~~~~~^~~~ >>>> ../target/i386/ops_sse.h:2493:13: error: ‘r1’ may be used uninitialized in this function [-Werror=maybe-uninitialized] >>>> 2493 | d->Q(1) = r1; >>>> | ~~~~~~~~^~~~ >>>> ../target/i386/ops_sse.h:2492:13: error: ‘r0’ may be used uninitialized in this function [-Werror=maybe-uninitialized] >>>> 2492 | d->Q(0) = r0; >>>> | ~~~~~~~~^~~~ >>>> >>>> Signed-off-by: Eric Auger <eric.auger@redhat.com> >>>> Fixes: 790684776861 ("target/i386: reimplement 0x0f 0x3a, add AVX") >>>> >>>> --- >>>> >>>> Am I the only one getting this? Or anything wrong in my setup. >>> With Stefan's correct address. Forgive me for the noise. >> When is -Wmaybe-uninitialized used? QEMU's build system doesn't set >> it. Unless it's automatically set by meson this must be a manual >> --extra-cflags= option you set. > > I am using this configure cmd line: > > ./configure --prefix=/usr --sysconfdir=/etc --libexecdir=/usr/lib/qemu > --target-list=x86_64-softmmu --docdir=/usr/share/doc/qemu --enable-kvm > --extra-cflags=-O --enable-trace-backends=log --python=/usr/bin/python3 > --extra-cflags=-Wall --extra-cflags=-Wundef > --extra-cflags=-Wwrite-strings --extra-cflags=-Wmissing-prototypes > --extra-cflags=-fno-strict-aliasing --extra-cflags=-fno-common > --extra-cflags=-Werror=type-limits >> >> If you added it manually then let's fix this in 8.0 since it's not >> tested/supported and very few people will see this issue. Please include the relevant meson output in the commit description, i.e.: C compiler for the host machine: clang (clang 14.0.0 "Apple clang version 14.0.0 (clang-1400.0.29.202)") C linker for the host machine: clang ld64 820.1 Compilation host CPU : aarch64 host endianness : little C compiler : clang Host C compiler : clang C++ compiler : c++ Objective-C compiler : clang CFLAGS : -ggdb -Werror=incompatible-function-pointer-types -O2 -g CXXFLAGS : -ggdb -Werror=incompatible-function-pointer-types -O2 -g OBJCFLAGS : -ggdb -Werror=incompatible-function-pointer-types -ggdb -O2 -g LDFLAGS : -ggdb -Werror=incompatible-function-pointer-types QEMU_CFLAGS : ... QEMU_CXXFLAGS : ... QEMU_OBJCFLAGS : ... QEMU_LDFLAGS : -fstack-protector-strong Thanks, Phil.
On 12/7/22 17:55, Philippe Mathieu-Daudé wrote: > On 7/12/22 15:33, Eric Auger wrote: >> On 12/7/22 15:09, Stefan Hajnoczi wrote: >>> On Wed, 7 Dec 2022 at 08:31, Eric Auger <eric.auger@redhat.com> wrote: >>>> On 12/7/22 14:24, Eric Auger wrote: >>>>> Initialize r0-3 to avoid compilation errors when >>>>> -Werror=maybe-uninitialized is used >>>>> >>>>> ../target/i386/ops_sse.h: In function ‘helper_vpermdq_ymm’: >>>>> ../target/i386/ops_sse.h:2495:13: error: ‘r3’ may be used >>>>> uninitialized in this function [-Werror=maybe-uninitialized] >>>>> 2495 | d->Q(3) = r3; >>>>> | ~~~~~~~~^~~~ >>>>> ../target/i386/ops_sse.h:2494:13: error: ‘r2’ may be used >>>>> uninitialized in this function [-Werror=maybe-uninitialized] >>>>> 2494 | d->Q(2) = r2; >>>>> | ~~~~~~~~^~~~ >>>>> ../target/i386/ops_sse.h:2493:13: error: ‘r1’ may be used >>>>> uninitialized in this function [-Werror=maybe-uninitialized] >>>>> 2493 | d->Q(1) = r1; >>>>> | ~~~~~~~~^~~~ >>>>> ../target/i386/ops_sse.h:2492:13: error: ‘r0’ may be used >>>>> uninitialized in this function [-Werror=maybe-uninitialized] >>>>> 2492 | d->Q(0) = r0; >>>>> | ~~~~~~~~^~~~ >>>>> >>>>> Signed-off-by: Eric Auger <eric.auger@redhat.com> >>>>> Fixes: 790684776861 ("target/i386: reimplement 0x0f 0x3a, add AVX") >>>>> >>>>> --- >>>>> >>>>> Am I the only one getting this? Or anything wrong in my setup. >>>> With Stefan's correct address. Forgive me for the noise. >>> When is -Wmaybe-uninitialized used? QEMU's build system doesn't set >>> it. Unless it's automatically set by meson this must be a manual >>> --extra-cflags= option you set. >> >> I am using this configure cmd line: >> >> ./configure --prefix=/usr --sysconfdir=/etc --libexecdir=/usr/lib/qemu >> --target-list=x86_64-softmmu --docdir=/usr/share/doc/qemu --enable-kvm >> --extra-cflags=-O --enable-trace-backends=log --python=/usr/bin/python3 >> --extra-cflags=-Wall --extra-cflags=-Wundef >> --extra-cflags=-Wwrite-strings --extra-cflags=-Wmissing-prototypes >> --extra-cflags=-fno-strict-aliasing --extra-cflags=-fno-common >> --extra-cflags=-Werror=type-limits >>> >>> If you added it manually then let's fix this in 8.0 since it's not >>> tested/supported and very few people will see this issue. > Please include the relevant meson output in the commit description, i.e.: > > C compiler for the host machine: clang (clang 14.0.0 "Apple clang > version 14.0.0 (clang-1400.0.29.202)") > C linker for the host machine: clang ld64 820.1 > > Compilation > host CPU : aarch64 > host endianness : little > C compiler : clang > Host C compiler : clang > C++ compiler : c++ > Objective-C compiler : clang > CFLAGS : -ggdb > -Werror=incompatible-function-pointer-types -O2 -g > CXXFLAGS : -ggdb > -Werror=incompatible-function-pointer-types -O2 -g > OBJCFLAGS : -ggdb > -Werror=incompatible-function-pointer-types -ggdb -O2 -g > LDFLAGS : -ggdb > -Werror=incompatible-function-pointer-types > QEMU_CFLAGS : ... > QEMU_CXXFLAGS : ... > QEMU_OBJCFLAGS : ... > QEMU_LDFLAGS : -fstack-protector-strong Here is the data: C compiler for the host machine: cc -m64 -mcx16 (gcc 11.3.1 "cc (GCC) 11.3.1 20220421 (Red Hat 11.3.1-2)") C linker for the host machine: cc -m64 -mcx16 ld.bfd 2.35.2-24 Compilation host CPU : x86_64 host endianness : little C compiler : cc -m64 -mcx16 Host C compiler : cc -m64 -mcx16 C++ compiler : c++ -m64 -mcx16 CFLAGS : -O -Wall -Wundef -Wwrite-strings -Wmissing-prototypes -fno-strict-aliasing -fno-common -Werror=type-limits -O2 -g CXXFLAGS : -O -Wall -Wundef -Wwrite-strings -Wmissing-prototypes -fno-strict-aliasing -fno-common -Werror=type-limits -O2 -g LDFLAGS : -O -Wall -Wundef -Wwrite-strings -Wmissing-prototypes -fno-strict-aliasing -fno-common -Werror=type-limits QEMU_CFLAGS : -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2 -D_GNU_SOURCE -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -Wstrict-prototypes -Wredundant-decls -Wundef -Wwrite-strings -Wmissing-prototypes -fno-strict-aliasing -fno-common -fwrapv -Wold-style-declaration -Wold-style-definition -Wtype-limits -Wformat-security -Wformat-y2k -Winit-self -Wignored-qualifiers -Wempty-body -Wnested-externs -Wendif-labels -Wexpansion-to-defined -Wimplicit-fallthrough=2 -Wno-missing-include-dirs -Wno-shift-negative-value -Wno-psabi -fstack-protector-strong QEMU_CXXFLAGS : -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2 -D_GNU_SOURCE -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -Wundef -Wwrite-strings -fno-strict-aliasing -fno-common -fwrapv -Wtype-limits -Wformat-security -Wformat-y2k -Winit-self -Wignored-qualifiers -Wempty-body -Wendif-labels -Wexpansion-to-defined -Wimplicit-fallthrough=2 -Wno-missing-include-dirs -Wno-shift-negative-value -Wno-psabi -fstack-protector-strong QEMU_OBJCFLAGS : QEMU_LDFLAGS : -fstack-protector-strong -Wl,-z,relro -Wl,-z,now Eric > > Thanks, > > Phil. >
On 12/7/22 10:08, Eric Auger wrote: > On 12/7/22 16:55, Stefan Hajnoczi wrote: >>> I am using this configure cmd line: >>> >>> ./configure --prefix=/usr --sysconfdir=/etc --libexecdir=/usr/lib/qemu >>> --target-list=x86_64-softmmu --docdir=/usr/share/doc/qemu --enable-kvm >>> --extra-cflags=-O --enable-trace-backends=log --python=/usr/bin/python3 >>> --extra-cflags=-Wall --extra-cflags=-Wundef >>> --extra-cflags=-Wwrite-strings --extra-cflags=-Wmissing-prototypes >>> --extra-cflags=-fno-strict-aliasing --extra-cflags=-fno-common >>> --extra-cflags=-Werror=type-limits >>>> If you added it manually then let's fix this in 8.0 since it's not >>>> tested/supported and very few people will see this issue. >> Did you create the ./configure command-line manually? Do you think >> other people will hit this? > no I did not. I just tried to install a fresh qemu repo and just ran the > above configure command. Stefan's question is where did you get this configure command? If it came from an rpm script or suchlike, we might take more notice than if this is just you adding --extra-cflags for your own testing. > I am actually surprised nobody hit that already. Adding -Wall is not standard, nor all the other -W that you are adding. I think you should not be surprised that you run into problems. While you can make a case for auditing the code base and adding these to the default set of warning flags, that's a job for the next development cycle. r~
Hi, On 12/7/22 19:23, Richard Henderson wrote: > On 12/7/22 10:08, Eric Auger wrote: >> On 12/7/22 16:55, Stefan Hajnoczi wrote: >>>> I am using this configure cmd line: >>>> >>>> ./configure --prefix=/usr --sysconfdir=/etc --libexecdir=/usr/lib/qemu >>>> --target-list=x86_64-softmmu --docdir=/usr/share/doc/qemu --enable-kvm >>>> --extra-cflags=-O --enable-trace-backends=log >>>> --python=/usr/bin/python3 >>>> --extra-cflags=-Wall --extra-cflags=-Wundef >>>> --extra-cflags=-Wwrite-strings --extra-cflags=-Wmissing-prototypes >>>> --extra-cflags=-fno-strict-aliasing --extra-cflags=-fno-common >>>> --extra-cflags=-Werror=type-limits >>>>> If you added it manually then let's fix this in 8.0 since it's not >>>>> tested/supported and very few people will see this issue. >>> Did you create the ./configure command-line manually? Do you think >>> other people will hit this? >> no I did not. I just tried to install a fresh qemu repo and just ran the >> above configure command. > > Stefan's question is where did you get this configure command? this is the native unmodified configure from https://git.qemu.org/git/qemu.git/. > > If it came from an rpm script or suchlike, we might take more notice > than if this is just you adding --extra-cflags for your own testing. > > >> I am actually surprised nobody hit that already. > > Adding -Wall is not standard, nor all the other -W that you are > adding. I think you should not be surprised that you run into problems. OK that's a useful indication. I used to have this configure cmd line for a while and have not paid much attention to it until now, I acknowledge. This was useful to catch compilation errors at some point I guess. > > While you can make a case for auditing the code base and adding these > to the default set of warning flags, that's a job for the next > development cycle. Let me clarify, I am not insisting for that fix to land in 7.2 all the more so it is pretty late. I just wanted to report the compilation issue and since I use the std qemu pieces with a pretty standard tool chain I thought somebody else would be likely to hit the same problem. Thanks Eric > > > r~ >
Am 07.12.22 um 19:22 schrieb Eric Auger: > > On 12/7/22 17:55, Philippe Mathieu-Daudé wrote: >> On 7/12/22 15:33, Eric Auger wrote: >>> On 12/7/22 15:09, Stefan Hajnoczi wrote: >>>> On Wed, 7 Dec 2022 at 08:31, Eric Auger <eric.auger@redhat.com> wrote: >>>>> On 12/7/22 14:24, Eric Auger wrote: >>>>>> Initialize r0-3 to avoid compilation errors when >>>>>> -Werror=maybe-uninitialized is used >>>>>> >>>>>> ../target/i386/ops_sse.h: In function ‘helper_vpermdq_ymm’: >>>>>> ../target/i386/ops_sse.h:2495:13: error: ‘r3’ may be used >>>>>> uninitialized in this function [-Werror=maybe-uninitialized] >>>>>> 2495 | d->Q(3) = r3; >>>>>> | ~~~~~~~~^~~~ >>>>>> ../target/i386/ops_sse.h:2494:13: error: ‘r2’ may be used >>>>>> uninitialized in this function [-Werror=maybe-uninitialized] >>>>>> 2494 | d->Q(2) = r2; >>>>>> | ~~~~~~~~^~~~ >>>>>> ../target/i386/ops_sse.h:2493:13: error: ‘r1’ may be used >>>>>> uninitialized in this function [-Werror=maybe-uninitialized] >>>>>> 2493 | d->Q(1) = r1; >>>>>> | ~~~~~~~~^~~~ >>>>>> ../target/i386/ops_sse.h:2492:13: error: ‘r0’ may be used >>>>>> uninitialized in this function [-Werror=maybe-uninitialized] >>>>>> 2492 | d->Q(0) = r0; >>>>>> | ~~~~~~~~^~~~ >>>>>> >>>>>> Signed-off-by: Eric Auger <eric.auger@redhat.com> >>>>>> Fixes: 790684776861 ("target/i386: reimplement 0x0f 0x3a, add AVX") >>>>>> >>>>>> --- >>>>>> >>>>>> Am I the only one getting this? Or anything wrong in my setup. Hi Eric, no, you are not the only one. I regularly build with higher warning levels, for example with -Weverything on macOS, and get a much longer list which includes the mentioned warnings (see below). The warnings for ops_sse.h are false positives, so I think no fix is needed for 7.2. The compiler is not clever enough to see that the switch statements handle all possible cases. It should be sufficient to replace `case 3` by `default` to help the compiler and fix the warning. Your fix might produce new compiler warnings because setting the variables to 0 has no effect. Cheers Stefan ../block/mirror.c:1024:13: warning: variable 'iostatus' may be uninitialized when used here [-Wconditional-uninitialized] ../block/mirror.c:1498:20: warning: variable 'bounce_buf' may be uninitialized when used here [-Wconditional-uninitialized] ../block/nbd.c:1208:24: warning: variable 'request_ret' may be uninitialized when used here [-Wconditional-uninitialized] ../block/nbd.c:1266:24: warning: variable 'request_ret' may be uninitialized when used here [-Wconditional-uninitialized] ../block/nbd.c:1424:20: warning: variable 'request_ret' may be uninitialized when used here [-Wconditional-uninitialized] ../block/qcow2-snapshot.c:423:51: warning: variable 'snapshots_size' may be uninitialized when used here [-Wconditional-uninitialized] ../block/qcow2.c:3236:23: warning: variable 'cur_bytes' may be uninitialized when used here [-Wconditional-uninitialized] ../block/ssh.c:306:52: warning: variable 'server_hash_len' may be uninitialized when used here [-Wconditional-uninitialized] ../block/ssh.c:313:45: warning: variable 'pubkey_type' may be uninitialized when used here [-Wconditional-uninitialized] ../contrib/elf2dmp/main.c:138:17: warning: variable 'kwn' may be uninitialized when used here [-Wconditional-uninitialized] ../contrib/elf2dmp/main.c:138:22: warning: variable 'kwa' may be uninitialized when used here [-Wconditional-uninitialized] ../contrib/elf2dmp/main.c:138:27: warning: variable 'KdpDataBlockEncoded' may be uninitialized when used here [-Wconditional-uninitialized] ../crypto/block-luks.c:844:29: warning: variable 'splitkeylen' may be uninitialized when used here [-Wconditional-uninitialized] ../disas/m68k.c:1513:47: warning: variable 'flval' may be uninitialized when used here [-Wconditional-uninitialized] ../dump/win_dump.c:105:18: warning: variable 'ptr64' may be uninitialized when used here [-Wconditional-uninitialized] ../dump/win_dump.c:105:26: warning: variable 'ptr32' may be uninitialized when used here [-Wconditional-uninitialized] ../gdbstub/gdbstub.c:1191:39: warning: variable 'pid' may be uninitialized when used here [-Wconditional-uninitialized] ../gdbstub/gdbstub.c:1209:36: warning: variable 'tid' may be uninitialized when used here [-Wconditional-uninitialized] ../hw/9pfs/9p.c:1911:13: warning: variable 'fidst' may be uninitialized when used here [-Wconditional-uninitialized] ../hw/block/block.c:110:33: warning: variable 'bs' may be uninitialized when used here [-Wconditional-uninitialized] ../hw/core/generic-loader.c:160:23: warning: variable 'entry' may be uninitialized when used here [-Wconditional-uninitialized] ../hw/i386/intel_iommu.c:323:12: warning: variable 'entry' may be uninitialized when used here [-Wconditional-uninitialized] ../hw/ide/ahci.c:968:60: warning: variable 'tbl_entry_size' may be uninitialized when used here [-Wconditional-uninitialized] ../hw/microblaze/boot.c:107:42: warning: variable 'fdt_size' may be uninitialized when used here [-Wconditional-uninitialized] ../hw/net/rtl8139.c:1801:20: warning: variable 'buf2' may be uninitialized when used here [-Wconditional-uninitialized] ../hw/nios2/boot.c:118:44: warning: variable 'fdt_size' may be uninitialized when used here [-Wconditional-uninitialized] ../hw/nvram/fw_cfg.c:1254:40: warning: variable 'data' may be uninitialized when used here [-Wconditional-uninitialized] ../hw/ppc/mac_oldworld.c:148:26: warning: variable 'bios_addr' may be uninitialized when used here [-Wconditional-uninitialized] ../hw/ppc/spapr.c:274:55: warning: variable 'pa_size' may be uninitialized when used here [-Wconditional-uninitialized] ../hw/riscv/microchip_pfsoc.c:609:54: warning: variable 'firmware_load_addr' may be uninitialized when used here [-Wconditional-uninitialized] ../hw/s390x/css.c:553:9: warning: variable 'ret' may be uninitialized when used here [-Wconditional-uninitialized] ../hw/s390x/ipl.c:410:17: warning: variable 'devtype' may be uninitialized when used here [-Wconditional-uninitialized] ../hw/s390x/s390-pci-inst.c:156:39: warning: variable 'res_code' may be uninitialized when used here [-Wconditional-uninitialized] ../hw/sd/sdhci.c:844:17: warning: variable 'res' may be uninitialized when used here [-Wconditional-uninitialized] ../hw/sparc64/sun4u_iommu.c:159:66: warning: variable 'offset' may be uninitialized when used here [-Wconditional-uninitialized] ../hw/xtensa/mx_pic.c:260:27: warning: variable 'oldv' may be uninitialized when used here [-Wconditional-uninitialized] ../hw/xtensa/mx_pic.c:260:33: warning: variable 'newv' may be uninitialized when used here [-Wconditional-uninitialized] ../migration/block.c:989:17: warning: variable 'ret' may be uninitialized when used here [-Wconditional-uninitialized] ../migration/migration.c:2847:17: warning: variable 'file' may be uninitialized when used here [-Wconditional-uninitialized] ../migration/ram.c:2088:24: warning: variable 'dirty' may be uninitialized when used here [-Wconditional-uninitialized] ../migration/savevm.c:721:30: warning: variable 'se' may be uninitialized when used here [-Wconditional-uninitialized] ../monitor/misc.c:1908:20: warning: variable 'snapshots' may be uninitialized when used here [-Wconditional-uninitialized] ../nbd/client-connection.c:419:9: warning: variable 'wait_co' may be uninitialized when used here [-Wconditional-uninitialized] ../net/socket.c:389:24: warning: variable 'saddr' may be uninitialized when used here [-Wconditional-uninitialized] ../net/tap-bsd.c:70:9: warning: variable 'fd' may be uninitialized when used here [-Wconditional-uninitialized] ../plugins/loader.c:406:17: warning: variable 'ctx' may be uninitialized when used here [-Wconditional-uninitialized] ../qemu-nbd.c:1175:22: warning: variable 'client_thread' may be uninitialized when used here [-Wconditional-uninitialized] ../softmmu/vl.c:1006:13: warning: variable 'opts' may be uninitialized when used here [-Wconditional-uninitialized] ../target/arm/helper.c:3299:17: warning: variable 'target_el' may be uninitialized when used here [-Wconditional-uninitialized] ../target/arm/m_helper.c:1727:37: warning: variable 'xpsr' may be uninitialized when used here [-Wconditional-uninitialized] ../target/arm/m_helper.c:1814:36: warning: variable 'shi' may be uninitialized when used here [-Wconditional-uninitialized] ../target/arm/m_helper.c:1814:48: warning: variable 'slo' may be uninitialized when used here [-Wconditional-uninitialized] ../target/arm/m_helper.c:1820:40: warning: variable 'fpscr' may be uninitialized when used here [-Wconditional-uninitialized] ../target/arm/translate-a64.c:10572:51: warning: variable 'rmode' may be uninitialized when used here [-Wconditional-uninitialized] ../target/arm/translate-a64.c:13225:51: warning: variable 'rmode' may be uninitialized when used here [-Wconditional-uninitialized] ../target/arm/translate-a64.c:8519:34: warning: variable 'tcg_src_hi' may be uninitialized when used here [-Wconditional-uninitialized] ../target/arm/translate.c:1590:50: warning: variable 'tmp' may be uninitialized when used here [-Wconditional-uninitialized] ../target/cris/mmu.c:201:33: warning: variable 'lo' may be uninitialized when used here [-Wconditional-uninitialized] ../target/i386/ops_sse.h:2492:15: warning: variable 'r0' may be uninitialized when used here [-Wconditional-uninitialized] ../target/i386/ops_sse.h:2493:15: warning: variable 'r1' may be uninitialized when used here [-Wconditional-uninitialized] ../target/i386/ops_sse.h:2494:15: warning: variable 'r2' may be uninitialized when used here [-Wconditional-uninitialized] ../target/i386/ops_sse.h:2495:15: warning: variable 'r3' may be uninitialized when used here [-Wconditional-uninitialized] ../target/m68k/softfloat.c:825:44: warning: variable 'm1' may be uninitialized when used here [-Wconditional-uninitialized] ../target/ppc/int_helper.c:1251:10: warning: variable 'result' may be uninitialized when used here [-Wconditional-uninitialized] ../target/ppc/int_helper.c:1269:10: warning: variable 'result' may be uninitialized when used here [-Wconditional-uninitialized] ../target/ppc/int_helper.c:1493:10: warning: variable 'result' may be uninitialized when used here [-Wconditional-uninitialized] ../target/ppc/int_helper.c:1516:1: warning: variable 'result' may be uninitialized when used here [-Wconditional-uninitialized] ../target/ppc/int_helper.c:1517:1: warning: variable 'result' may be uninitialized when used here [-Wconditional-uninitialized] ../target/ppc/int_helper.c:1518:1: warning: variable 'result' may be uninitialized when used here [-Wconditional-uninitialized] ../target/ppc/int_helper.c:1519:1: warning: variable 'result' may be uninitialized when used here [-Wconditional-uninitialized] ../target/ppc/int_helper.c:1520:1: warning: variable 'result' may be uninitialized when used here [-Wconditional-uninitialized] ../target/ppc/int_helper.c:1521:1: warning: variable 'result' may be uninitialized when used here [-Wconditional-uninitialized] ../target/ppc/int_helper.c:1522:1: warning: variable 'result' may be uninitialized when used here [-Wconditional-uninitialized] ../target/ppc/int_helper.c:1523:1: warning: variable 'result' may be uninitialized when used here [-Wconditional-uninitialized] ../target/ppc/int_helper.c:1524:1: warning: variable 'result' may be uninitialized when used here [-Wconditional-uninitialized] ../target/ppc/int_helper.c:1525:1: warning: variable 'result' may be uninitialized when used here [-Wconditional-uninitialized] ../target/ppc/int_helper.c:1526:1: warning: variable 'result' may be uninitialized when used here [-Wconditional-uninitialized] ../target/ppc/int_helper.c:1527:1: warning: variable 'result' may be uninitialized when used here [-Wconditional-uninitialized] ../target/ppc/int_helper.c:1680:10: warning: variable 'result' may be uninitialized when used here [-Wconditional-uninitialized] ../target/ppc/int_helper.c:1954:10: warning: variable 'result' may be uninitialized when used here [-Wconditional-uninitialized] ../target/ppc/int_helper.c:2039:1: warning: variable 'result' may be uninitialized when used here [-Wconditional-uninitialized] ../target/ppc/int_helper.c:2040:1: warning: variable 'result' may be uninitialized when used here [-Wconditional-uninitialized] ../target/ppc/int_helper.c:2061:1: warning: variable 'result' may be uninitialized when used here [-Wconditional-uninitialized] ../target/ppc/int_helper.c:2062:1: warning: variable 'result' may be uninitialized when used here [-Wconditional-uninitialized] ../target/ppc/int_helper.c:2063:1: warning: variable 'result' may be uninitialized when used here [-Wconditional-uninitialized] ../target/ppc/int_helper.c:2064:1: warning: variable 'result' may be uninitialized when used here [-Wconditional-uninitialized] ../target/ppc/int_helper.c:2065:1: warning: variable 'result' may be uninitialized when used here [-Wconditional-uninitialized] ../target/ppc/int_helper.c:2066:1: warning: variable 'result' may be uninitialized when used here [-Wconditional-uninitialized] ../target/ppc/int_helper.c:2945:10: warning: variable 'result' may be uninitialized when used here [-Wconditional-uninitialized] ../target/ppc/int_helper.c:2956:10: warning: variable 'result' may be uninitialized when used here [-Wconditional-uninitialized] ../target/ppc/int_helper.c:2987:10: warning: variable 'result' may be uninitialized when used here [-Wconditional-uninitialized] ../target/ppc/int_helper.c:3063:10: warning: variable 'result' may be uninitialized when used here [-Wconditional-uninitialized] ../target/ppc/int_helper.c:967:1: warning: variable 'result' may be uninitialized when used here [-Wconditional-uninitialized] ../target/ppc/int_helper.c:968:1: warning: variable 'result' may be uninitialized when used here [-Wconditional-uninitialized] ../target/ppc/int_helper.c:969:1: warning: variable 'result' may be uninitialized when used here [-Wconditional-uninitialized] ../target/ppc/mmu-radix64.c:548:20: warning: variable 'pte' may be uninitialized when used here [-Wconditional-uninitialized] ../target/s390x/ioinst.c:364:52: warning: variable 'irb_len' may be uninitialized when used here [-Wconditional-uninitialized] ../target/s390x/tcg/mem_helper.c:2978:12: warning: variable 'cc' may be uninitialized when used here [-Wconditional-uninitialized] ../target/s390x/tcg/vec_fpu_helper.c:1023:26: warning: variable 'vxc' may be uninitialized when used here [-Wconditional-uninitialized] ../target/s390x/tcg/vec_fpu_helper.c:132:26: warning: variable 'vxc' may be uninitialized when used here [-Wconditional-uninitialized] ../target/s390x/tcg/vec_fpu_helper.c:156:26: warning: variable 'vxc' may be uninitialized when used here [-Wconditional-uninitialized] ../target/s390x/tcg/vec_fpu_helper.c:278:26: warning: variable 'vxc' may be uninitialized when used here [-Wconditional-uninitialized] ../target/s390x/tcg/vec_fpu_helper.c:301:26: warning: variable 'vxc' may be uninitialized when used here [-Wconditional-uninitialized] ../target/s390x/tcg/vec_fpu_helper.c:439:26: warning: variable 'vxc' may be uninitialized when used here [-Wconditional-uninitialized] ../target/s390x/tcg/vec_fpu_helper.c:471:26: warning: variable 'vxc' may be uninitialized when used here [-Wconditional-uninitialized] ../target/s390x/tcg/vec_fpu_helper.c:551:26: warning: variable 'vxc' may be uninitialized when used here [-Wconditional-uninitialized] ../target/s390x/tcg/vec_fpu_helper.c:592:26: warning: variable 'vxc' may be uninitialized when used here [-Wconditional-uninitialized] ../target/s390x/tcg/vec_fpu_helper.c:635:26: warning: variable 'vxc' may be uninitialized when used here [-Wconditional-uninitialized] ../target/s390x/tcg/vec_fpu_helper.c:659:26: warning: variable 'vxc' may be uninitialized when used here [-Wconditional-uninitialized] ../target/s390x/tcg/vec_fpu_helper.c:961:26: warning: variable 'vxc' may be uninitialized when used here [-Wconditional-uninitialized] ../target/s390x/tcg/vec_helper.c:189:25: warning: variable 'tmp' may be uninitialized when used here [-Wconditional-uninitialized] ../target/s390x/tcg/vec_helper.c:89:1: warning: variable 'tmp' may be uninitialized when used here [-Wconditional-uninitialized] ../target/s390x/tcg/vec_helper.c:90:1: warning: variable 'tmp' may be uninitialized when used here [-Wconditional-uninitialized] ../target/s390x/tcg/vec_helper.c:91:1: warning: variable 'tmp' may be uninitialized when used here [-Wconditional-uninitialized] ../target/s390x/tcg/vec_int_helper.c:556:25: warning: variable 'tmp' may be uninitialized when used here [-Wconditional-uninitialized] ../target/s390x/tcg/vec_int_helper.c:606:25: warning: variable 'tmp' may be uninitialized when used here [-Wconditional-uninitialized] ../target/xtensa/translate.c:1074:51: warning: variable 'resource' may be uninitialized when used here [-Wconditional-uninitialized] ../target/xtensa/translate.c:1092:35: warning: variable 'temp' may be uninitialized when used here [-Wconditional-uninitialized] ../target/xtensa/translate.c:936:72: warning: variable 'rf' may be uninitialized when used here [-Wconditional-uninitialized] ../target/xtensa/xtensa-semi.c:297:17: warning: variable 'rc' may be uninitialized when used here [-Wconditional-uninitialized] ../tests/fp/berkeley-softfloat-3/source/s_shiftRightJam256M.c:117:10: warning: variable 'ptr' may be uninitialized when used here [-Wconditional-uninitialized] ../tests/fp/berkeley-testfloat-3/source/slowfloat.c:1015:13: warning: variable 'uiZ' may be uninitialized when used here [-Wconditional-uninitialized] ../tests/fp/berkeley-testfloat-3/source/slowfloat.c:742:13: warning: variable 'uiZ' may be uninitialized when used here [-Wconditional-uninitialized] ../tests/fp/berkeley-testfloat-3/source/slowfloat.c:878:13: warning: variable 'uiZ' may be uninitialized when used here [-Wconditional-uninitialized] ../tests/qtest/boot-sector.c:169:21: warning: variable 'signature' may be uninitialized when used here [-Wconditional-uninitialized] ../tests/qtest/prom-env-test.c:43:21: warning: variable 'signature' may be uninitialized when used here [-Wconditional-uninitialized] ../tests/unit/test-bdrv-drain.c:1022:21: warning: variable 'ret' may be uninitialized when used here [-Wconditional-uninitialized] ../tests/unit/test-block-iothread.c:772:14: warning: variable 'job' may be uninitialized when used here [-Wconditional-uninitialized] ../ui/vnc-enc-tight.c:416:1: warning: variable 'ci' may be uninitialized when used here [-Wconditional-uninitialized] ../ui/vnc-enc-tight.c:417:1: warning: variable 'ci' may be uninitialized when used here [-Wconditional-uninitialized] ../ui/vnc-enc-tight.c:418:1: warning: variable 'ci' may be uninitialized when used here [-Wconditional-uninitialized] ../util/iov.c:469:52: warning: variable 'mid_head' may be uninitialized when used here [-Wconditional-uninitialized] ../util/iov.c:471:36: warning: variable 'mid_tail' may be uninitialized when used here [-Wconditional-uninitialized] ../util/qemu-timer.c:198:12: warning: variable 'expire_time' may be uninitialized when used here [-Wconditional-uninitialized] ../util/qemu-timer.c:236:13: warning: variable 'expire_time' may be uninitialized when used here [-Wconditional-uninitialized] ../util/qemu-timer.c:476:9: warning: variable 'rearm' may be uninitialized when used here [-Wconditional-uninitialized]
On Wed, 7 Dec 2022 at 14:11, Stefan Weil <sw@weilnetz.de> wrote: > > Am 07.12.22 um 19:22 schrieb Eric Auger: > > > > On 12/7/22 17:55, Philippe Mathieu-Daudé wrote: > >> On 7/12/22 15:33, Eric Auger wrote: > >>> On 12/7/22 15:09, Stefan Hajnoczi wrote: > >>>> On Wed, 7 Dec 2022 at 08:31, Eric Auger <eric.auger@redhat.com> wrote: > >>>>> On 12/7/22 14:24, Eric Auger wrote: > >>>>>> Initialize r0-3 to avoid compilation errors when > >>>>>> -Werror=maybe-uninitialized is used > >>>>>> > >>>>>> ../target/i386/ops_sse.h: In function ‘helper_vpermdq_ymm’: > >>>>>> ../target/i386/ops_sse.h:2495:13: error: ‘r3’ may be used > >>>>>> uninitialized in this function [-Werror=maybe-uninitialized] > >>>>>> 2495 | d->Q(3) = r3; > >>>>>> | ~~~~~~~~^~~~ > >>>>>> ../target/i386/ops_sse.h:2494:13: error: ‘r2’ may be used > >>>>>> uninitialized in this function [-Werror=maybe-uninitialized] > >>>>>> 2494 | d->Q(2) = r2; > >>>>>> | ~~~~~~~~^~~~ > >>>>>> ../target/i386/ops_sse.h:2493:13: error: ‘r1’ may be used > >>>>>> uninitialized in this function [-Werror=maybe-uninitialized] > >>>>>> 2493 | d->Q(1) = r1; > >>>>>> | ~~~~~~~~^~~~ > >>>>>> ../target/i386/ops_sse.h:2492:13: error: ‘r0’ may be used > >>>>>> uninitialized in this function [-Werror=maybe-uninitialized] > >>>>>> 2492 | d->Q(0) = r0; > >>>>>> | ~~~~~~~~^~~~ > >>>>>> > >>>>>> Signed-off-by: Eric Auger <eric.auger@redhat.com> > >>>>>> Fixes: 790684776861 ("target/i386: reimplement 0x0f 0x3a, add AVX") > >>>>>> > >>>>>> --- > >>>>>> > >>>>>> Am I the only one getting this? Or anything wrong in my setup. > > Hi Eric, > > no, you are not the only one. I regularly build with higher warning > levels, for example with -Weverything on macOS, and get a much longer > list which includes the mentioned warnings (see below). > > The warnings for ops_sse.h are false positives, so I think no fix is > needed for 7.2. The compiler is not clever enough to see that the switch > statements handle all possible cases. It should be sufficient to replace > `case 3` by `default` to help the compiler and fix the warning. Your fix > might produce new compiler warnings because setting the variables to 0 > has no effect. Eric: do you want to try the switch "default" approach for 8.0? Thanks, Stefan
Am 07.12.22 um 20:11 schrieb Stefan Weil: >>>>>> On 12/7/22 14:24, Eric Auger wrote: >>>>>>> Initialize r0-3 to avoid compilation errors when >>>>>>> -Werror=maybe-uninitialized is used >>>>>>> >>>>>>> ../target/i386/ops_sse.h: In function ‘helper_vpermdq_ymm’: >>>>>>> ../target/i386/ops_sse.h:2495:13: error: ‘r3’ may be used >>>>>>> uninitialized in this function [-Werror=maybe-uninitialized] >>>>>>> 2495 | d->Q(3) = r3; >>>>>>> | ~~~~~~~~^~~~ >>>>>>> ../target/i386/ops_sse.h:2494:13: error: ‘r2’ may be used >>>>>>> uninitialized in this function [-Werror=maybe-uninitialized] >>>>>>> 2494 | d->Q(2) = r2; >>>>>>> | ~~~~~~~~^~~~ >>>>>>> ../target/i386/ops_sse.h:2493:13: error: ‘r1’ may be used >>>>>>> uninitialized in this function [-Werror=maybe-uninitialized] >>>>>>> 2493 | d->Q(1) = r1; >>>>>>> | ~~~~~~~~^~~~ >>>>>>> ../target/i386/ops_sse.h:2492:13: error: ‘r0’ may be used >>>>>>> uninitialized in this function [-Werror=maybe-uninitialized] >>>>>>> 2492 | d->Q(0) = r0; >>>>>>> | ~~~~~~~~^~~~ >>>>>>> >>>>>>> Signed-off-by: Eric Auger <eric.auger@redhat.com> >>>>>>> Fixes: 790684776861 ("target/i386: reimplement 0x0f 0x3a, add AVX") >>>>>>> >>>>>>> --- >>>>>>> >>>>>>> Am I the only one getting this? Or anything wrong in my setup. > > Hi Eric, > > no, you are not the only one. I regularly build with higher warning > levels, for example with -Weverything on macOS, and get a much longer > list which includes the mentioned warnings (see below). The latest QEMU code produces 6780505 compiler warnings and a build log file with 2.7 GB (!) with compiler option `-Weverything` on macOS. Many warnings occur more than once, but there remain 193313 unique warnings for the QEMU code (see https://qemu.weilnetz.de/test/warnings-20221207.txt). Here is a list of all kinds of warnings sorted by frequency: 1 -Wkeyword-macro 1 -Wundeclared-selector 1 -Wunreachable-code-loop-increment 1 -Wunused-but-set-parameter 2 -Wgnu-union-cast 2 -Woverlength-strings 3 -Walloca 5 -Wflexible-array-extensions 5 -Wstrict-selector-match 5 -Wstring-conversion 5 -Wtautological-value-range-compare 6 -Wcstring-format-directive 8 -Wstatic-in-inline 13 -Wobjc-messaging-id 13 -Wvla 14 -Wobjc-interface-ivars 16 -Wimplicit-float-conversion 17 -Wformat-nonliteral 24 -Wredundant-parens 39 -Wfloat-equal 44 -Wc++-compat 47 -Wzero-length-array 53 -Wdouble-promotion 53 -Wvariadic-macros 65 -Wpacked 74 -Wcomma 82 -Wunreachable-code-return 90 -Wformat-pedantic 90 -Wmissing-noreturn 94 -Wgnu-flexible-array-initializer 120 -Wcovered-switch-default 132 -Wdirect-ivar-access 136 -Wconditional-uninitialized 144 -Wgnu-designator 147 -Wdisabled-macro-expansion 150 -Wgnu-conditional-omitted-operand 161 -Wunreachable-code-break 184 -Wcompound-token-split-by-space 228 -Wfloat-conversion 248 -Wunreachable-code 348 -Wgnu-binary-literal 443 -Wshadow 534 -Wmissing-variable-declarations 563 -Wshift-sign-overflow 613 -Wembedded-directive 620 -Wgnu-zero-variadic-macro-arguments 742 -Wswitch-enum 843 -Wdocumentation 897 -Wgnu-case-range 1292 -Wassign-enum 1621 -Wgnu-empty-struct 1700 -Wextra-semi 1779 -Wpointer-arith 1847 -Wbad-function-cast 2176 -Wdocumentation-unknown-command 2221 -Wmissing-field-initializers 3101 -Wsign-compare 3238 -Wunused-macros 3559 -Wcast-align 4528 -Wcast-qual 7066 -Wgnu-statement-expression 7651 -Wnull-pointer-subtraction 7995 -Wimplicit-int-conversion 8854 -Wpadded 9737 -Wshorten-64-to-32 10596 -Wgnu-empty-initializer 13274 -Wlanguage-extension-token 13899 -Wunused-parameter 15642 -Wused-but-marked-unused 18669 -Wpedantic 44737 -Wsign-conversion
Hi Stefan, On 12/7/22 20:59, Stefan Hajnoczi wrote: > On Wed, 7 Dec 2022 at 14:11, Stefan Weil <sw@weilnetz.de> wrote: >> Am 07.12.22 um 19:22 schrieb Eric Auger: >>> On 12/7/22 17:55, Philippe Mathieu-Daudé wrote: >>>> On 7/12/22 15:33, Eric Auger wrote: >>>>> On 12/7/22 15:09, Stefan Hajnoczi wrote: >>>>>> On Wed, 7 Dec 2022 at 08:31, Eric Auger <eric.auger@redhat.com> wrote: >>>>>>> On 12/7/22 14:24, Eric Auger wrote: >>>>>>>> Initialize r0-3 to avoid compilation errors when >>>>>>>> -Werror=maybe-uninitialized is used >>>>>>>> >>>>>>>> ../target/i386/ops_sse.h: In function ‘helper_vpermdq_ymm’: >>>>>>>> ../target/i386/ops_sse.h:2495:13: error: ‘r3’ may be used >>>>>>>> uninitialized in this function [-Werror=maybe-uninitialized] >>>>>>>> 2495 | d->Q(3) = r3; >>>>>>>> | ~~~~~~~~^~~~ >>>>>>>> ../target/i386/ops_sse.h:2494:13: error: ‘r2’ may be used >>>>>>>> uninitialized in this function [-Werror=maybe-uninitialized] >>>>>>>> 2494 | d->Q(2) = r2; >>>>>>>> | ~~~~~~~~^~~~ >>>>>>>> ../target/i386/ops_sse.h:2493:13: error: ‘r1’ may be used >>>>>>>> uninitialized in this function [-Werror=maybe-uninitialized] >>>>>>>> 2493 | d->Q(1) = r1; >>>>>>>> | ~~~~~~~~^~~~ >>>>>>>> ../target/i386/ops_sse.h:2492:13: error: ‘r0’ may be used >>>>>>>> uninitialized in this function [-Werror=maybe-uninitialized] >>>>>>>> 2492 | d->Q(0) = r0; >>>>>>>> | ~~~~~~~~^~~~ >>>>>>>> >>>>>>>> Signed-off-by: Eric Auger <eric.auger@redhat.com> >>>>>>>> Fixes: 790684776861 ("target/i386: reimplement 0x0f 0x3a, add AVX") >>>>>>>> >>>>>>>> --- >>>>>>>> >>>>>>>> Am I the only one getting this? Or anything wrong in my setup. >> Hi Eric, >> >> no, you are not the only one. I regularly build with higher warning >> levels, for example with -Weverything on macOS, and get a much longer >> list which includes the mentioned warnings (see below). >> >> The warnings for ops_sse.h are false positives, so I think no fix is >> needed for 7.2. The compiler is not clever enough to see that the switch >> statements handle all possible cases. It should be sufficient to replace >> `case 3` by `default` to help the compiler and fix the warning. Your fix >> might produce new compiler warnings because setting the variables to 0 >> has no effect. > Eric: do you want to try the switch "default" approach for 8.0? Yes sure! Eric > > Thanks, > Stefan >
Hi Stefan, On 12/7/22 20:11, Stefan Weil via wrote: > Am 07.12.22 um 19:22 schrieb Eric Auger: >> >> On 12/7/22 17:55, Philippe Mathieu-Daudé wrote: >>> On 7/12/22 15:33, Eric Auger wrote: >>>> On 12/7/22 15:09, Stefan Hajnoczi wrote: >>>>> On Wed, 7 Dec 2022 at 08:31, Eric Auger <eric.auger@redhat.com> >>>>> wrote: >>>>>> On 12/7/22 14:24, Eric Auger wrote: >>>>>>> Initialize r0-3 to avoid compilation errors when >>>>>>> -Werror=maybe-uninitialized is used >>>>>>> >>>>>>> ../target/i386/ops_sse.h: In function ‘helper_vpermdq_ymm’: >>>>>>> ../target/i386/ops_sse.h:2495:13: error: ‘r3’ may be used >>>>>>> uninitialized in this function [-Werror=maybe-uninitialized] >>>>>>> 2495 | d->Q(3) = r3; >>>>>>> | ~~~~~~~~^~~~ >>>>>>> ../target/i386/ops_sse.h:2494:13: error: ‘r2’ may be used >>>>>>> uninitialized in this function [-Werror=maybe-uninitialized] >>>>>>> 2494 | d->Q(2) = r2; >>>>>>> | ~~~~~~~~^~~~ >>>>>>> ../target/i386/ops_sse.h:2493:13: error: ‘r1’ may be used >>>>>>> uninitialized in this function [-Werror=maybe-uninitialized] >>>>>>> 2493 | d->Q(1) = r1; >>>>>>> | ~~~~~~~~^~~~ >>>>>>> ../target/i386/ops_sse.h:2492:13: error: ‘r0’ may be used >>>>>>> uninitialized in this function [-Werror=maybe-uninitialized] >>>>>>> 2492 | d->Q(0) = r0; >>>>>>> | ~~~~~~~~^~~~ >>>>>>> >>>>>>> Signed-off-by: Eric Auger <eric.auger@redhat.com> >>>>>>> Fixes: 790684776861 ("target/i386: reimplement 0x0f 0x3a, add AVX") >>>>>>> >>>>>>> --- >>>>>>> >>>>>>> Am I the only one getting this? Or anything wrong in my setup. > > Hi Eric, > > no, you are not the only one. I regularly build with higher warning > levels, for example with -Weverything on macOS, and get a much longer > list which includes the mentioned warnings (see below). thanks! Interesting to see the exhaustive list below and your stats sorted by warning category. > > The warnings for ops_sse.h are false positives, so I think no fix is > needed for 7.2. The compiler is not clever enough to see that the > switch statements handle all possible cases. It should be sufficient > to replace `case 3` by `default` to help the compiler and fix the > warning. Your fix might produce new compiler warnings because setting > the variables to 0 has no effect. OK. I will respin according to your suggestion for 8.0. Eric > > Cheers > Stefan > > ../block/mirror.c:1024:13: warning: variable 'iostatus' may be > uninitialized when used here [-Wconditional-uninitialized] > ../block/mirror.c:1498:20: warning: variable 'bounce_buf' may be > uninitialized when used here [-Wconditional-uninitialized] > ../block/nbd.c:1208:24: warning: variable 'request_ret' may be > uninitialized when used here [-Wconditional-uninitialized] > ../block/nbd.c:1266:24: warning: variable 'request_ret' may be > uninitialized when used here [-Wconditional-uninitialized] > ../block/nbd.c:1424:20: warning: variable 'request_ret' may be > uninitialized when used here [-Wconditional-uninitialized] > ../block/qcow2-snapshot.c:423:51: warning: variable 'snapshots_size' > may be uninitialized when used here [-Wconditional-uninitialized] > ../block/qcow2.c:3236:23: warning: variable 'cur_bytes' may be > uninitialized when used here [-Wconditional-uninitialized] > ../block/ssh.c:306:52: warning: variable 'server_hash_len' may be > uninitialized when used here [-Wconditional-uninitialized] > ../block/ssh.c:313:45: warning: variable 'pubkey_type' may be > uninitialized when used here [-Wconditional-uninitialized] > ../contrib/elf2dmp/main.c:138:17: warning: variable 'kwn' may be > uninitialized when used here [-Wconditional-uninitialized] > ../contrib/elf2dmp/main.c:138:22: warning: variable 'kwa' may be > uninitialized when used here [-Wconditional-uninitialized] > ../contrib/elf2dmp/main.c:138:27: warning: variable > 'KdpDataBlockEncoded' may be uninitialized when used here > [-Wconditional-uninitialized] > ../crypto/block-luks.c:844:29: warning: variable 'splitkeylen' may be > uninitialized when used here [-Wconditional-uninitialized] > ../disas/m68k.c:1513:47: warning: variable 'flval' may be > uninitialized when used here [-Wconditional-uninitialized] > ../dump/win_dump.c:105:18: warning: variable 'ptr64' may be > uninitialized when used here [-Wconditional-uninitialized] > ../dump/win_dump.c:105:26: warning: variable 'ptr32' may be > uninitialized when used here [-Wconditional-uninitialized] > ../gdbstub/gdbstub.c:1191:39: warning: variable 'pid' may be > uninitialized when used here [-Wconditional-uninitialized] > ../gdbstub/gdbstub.c:1209:36: warning: variable 'tid' may be > uninitialized when used here [-Wconditional-uninitialized] > ../hw/9pfs/9p.c:1911:13: warning: variable 'fidst' may be > uninitialized when used here [-Wconditional-uninitialized] > ../hw/block/block.c:110:33: warning: variable 'bs' may be > uninitialized when used here [-Wconditional-uninitialized] > ../hw/core/generic-loader.c:160:23: warning: variable 'entry' may be > uninitialized when used here [-Wconditional-uninitialized] > ../hw/i386/intel_iommu.c:323:12: warning: variable 'entry' may be > uninitialized when used here [-Wconditional-uninitialized] > ../hw/ide/ahci.c:968:60: warning: variable 'tbl_entry_size' may be > uninitialized when used here [-Wconditional-uninitialized] > ../hw/microblaze/boot.c:107:42: warning: variable 'fdt_size' may be > uninitialized when used here [-Wconditional-uninitialized] > ../hw/net/rtl8139.c:1801:20: warning: variable 'buf2' may be > uninitialized when used here [-Wconditional-uninitialized] > ../hw/nios2/boot.c:118:44: warning: variable 'fdt_size' may be > uninitialized when used here [-Wconditional-uninitialized] > ../hw/nvram/fw_cfg.c:1254:40: warning: variable 'data' may be > uninitialized when used here [-Wconditional-uninitialized] > ../hw/ppc/mac_oldworld.c:148:26: warning: variable 'bios_addr' may be > uninitialized when used here [-Wconditional-uninitialized] > ../hw/ppc/spapr.c:274:55: warning: variable 'pa_size' may be > uninitialized when used here [-Wconditional-uninitialized] > ../hw/riscv/microchip_pfsoc.c:609:54: warning: variable > 'firmware_load_addr' may be uninitialized when used here > [-Wconditional-uninitialized] > ../hw/s390x/css.c:553:9: warning: variable 'ret' may be uninitialized > when used here [-Wconditional-uninitialized] > ../hw/s390x/ipl.c:410:17: warning: variable 'devtype' may be > uninitialized when used here [-Wconditional-uninitialized] > ../hw/s390x/s390-pci-inst.c:156:39: warning: variable 'res_code' may > be uninitialized when used here [-Wconditional-uninitialized] > ../hw/sd/sdhci.c:844:17: warning: variable 'res' may be uninitialized > when used here [-Wconditional-uninitialized] > ../hw/sparc64/sun4u_iommu.c:159:66: warning: variable 'offset' may be > uninitialized when used here [-Wconditional-uninitialized] > ../hw/xtensa/mx_pic.c:260:27: warning: variable 'oldv' may be > uninitialized when used here [-Wconditional-uninitialized] > ../hw/xtensa/mx_pic.c:260:33: warning: variable 'newv' may be > uninitialized when used here [-Wconditional-uninitialized] > ../migration/block.c:989:17: warning: variable 'ret' may be > uninitialized when used here [-Wconditional-uninitialized] > ../migration/migration.c:2847:17: warning: variable 'file' may be > uninitialized when used here [-Wconditional-uninitialized] > ../migration/ram.c:2088:24: warning: variable 'dirty' may be > uninitialized when used here [-Wconditional-uninitialized] > ../migration/savevm.c:721:30: warning: variable 'se' may be > uninitialized when used here [-Wconditional-uninitialized] > ../monitor/misc.c:1908:20: warning: variable 'snapshots' may be > uninitialized when used here [-Wconditional-uninitialized] > ../nbd/client-connection.c:419:9: warning: variable 'wait_co' may be > uninitialized when used here [-Wconditional-uninitialized] > ../net/socket.c:389:24: warning: variable 'saddr' may be uninitialized > when used here [-Wconditional-uninitialized] > ../net/tap-bsd.c:70:9: warning: variable 'fd' may be uninitialized > when used here [-Wconditional-uninitialized] > ../plugins/loader.c:406:17: warning: variable 'ctx' may be > uninitialized when used here [-Wconditional-uninitialized] > ../qemu-nbd.c:1175:22: warning: variable 'client_thread' may be > uninitialized when used here [-Wconditional-uninitialized] > ../softmmu/vl.c:1006:13: warning: variable 'opts' may be uninitialized > when used here [-Wconditional-uninitialized] > ../target/arm/helper.c:3299:17: warning: variable 'target_el' may be > uninitialized when used here [-Wconditional-uninitialized] > ../target/arm/m_helper.c:1727:37: warning: variable 'xpsr' may be > uninitialized when used here [-Wconditional-uninitialized] > ../target/arm/m_helper.c:1814:36: warning: variable 'shi' may be > uninitialized when used here [-Wconditional-uninitialized] > ../target/arm/m_helper.c:1814:48: warning: variable 'slo' may be > uninitialized when used here [-Wconditional-uninitialized] > ../target/arm/m_helper.c:1820:40: warning: variable 'fpscr' may be > uninitialized when used here [-Wconditional-uninitialized] > ../target/arm/translate-a64.c:10572:51: warning: variable 'rmode' may > be uninitialized when used here [-Wconditional-uninitialized] > ../target/arm/translate-a64.c:13225:51: warning: variable 'rmode' may > be uninitialized when used here [-Wconditional-uninitialized] > ../target/arm/translate-a64.c:8519:34: warning: variable 'tcg_src_hi' > may be uninitialized when used here [-Wconditional-uninitialized] > ../target/arm/translate.c:1590:50: warning: variable 'tmp' may be > uninitialized when used here [-Wconditional-uninitialized] > ../target/cris/mmu.c:201:33: warning: variable 'lo' may be > uninitialized when used here [-Wconditional-uninitialized] > ../target/i386/ops_sse.h:2492:15: warning: variable 'r0' may be > uninitialized when used here [-Wconditional-uninitialized] > ../target/i386/ops_sse.h:2493:15: warning: variable 'r1' may be > uninitialized when used here [-Wconditional-uninitialized] > ../target/i386/ops_sse.h:2494:15: warning: variable 'r2' may be > uninitialized when used here [-Wconditional-uninitialized] > ../target/i386/ops_sse.h:2495:15: warning: variable 'r3' may be > uninitialized when used here [-Wconditional-uninitialized] > ../target/m68k/softfloat.c:825:44: warning: variable 'm1' may be > uninitialized when used here [-Wconditional-uninitialized] > ../target/ppc/int_helper.c:1251:10: warning: variable 'result' may be > uninitialized when used here [-Wconditional-uninitialized] > ../target/ppc/int_helper.c:1269:10: warning: variable 'result' may be > uninitialized when used here [-Wconditional-uninitialized] > ../target/ppc/int_helper.c:1493:10: warning: variable 'result' may be > uninitialized when used here [-Wconditional-uninitialized] > ../target/ppc/int_helper.c:1516:1: warning: variable 'result' may be > uninitialized when used here [-Wconditional-uninitialized] > ../target/ppc/int_helper.c:1517:1: warning: variable 'result' may be > uninitialized when used here [-Wconditional-uninitialized] > ../target/ppc/int_helper.c:1518:1: warning: variable 'result' may be > uninitialized when used here [-Wconditional-uninitialized] > ../target/ppc/int_helper.c:1519:1: warning: variable 'result' may be > uninitialized when used here [-Wconditional-uninitialized] > ../target/ppc/int_helper.c:1520:1: warning: variable 'result' may be > uninitialized when used here [-Wconditional-uninitialized] > ../target/ppc/int_helper.c:1521:1: warning: variable 'result' may be > uninitialized when used here [-Wconditional-uninitialized] > ../target/ppc/int_helper.c:1522:1: warning: variable 'result' may be > uninitialized when used here [-Wconditional-uninitialized] > ../target/ppc/int_helper.c:1523:1: warning: variable 'result' may be > uninitialized when used here [-Wconditional-uninitialized] > ../target/ppc/int_helper.c:1524:1: warning: variable 'result' may be > uninitialized when used here [-Wconditional-uninitialized] > ../target/ppc/int_helper.c:1525:1: warning: variable 'result' may be > uninitialized when used here [-Wconditional-uninitialized] > ../target/ppc/int_helper.c:1526:1: warning: variable 'result' may be > uninitialized when used here [-Wconditional-uninitialized] > ../target/ppc/int_helper.c:1527:1: warning: variable 'result' may be > uninitialized when used here [-Wconditional-uninitialized] > ../target/ppc/int_helper.c:1680:10: warning: variable 'result' may be > uninitialized when used here [-Wconditional-uninitialized] > ../target/ppc/int_helper.c:1954:10: warning: variable 'result' may be > uninitialized when used here [-Wconditional-uninitialized] > ../target/ppc/int_helper.c:2039:1: warning: variable 'result' may be > uninitialized when used here [-Wconditional-uninitialized] > ../target/ppc/int_helper.c:2040:1: warning: variable 'result' may be > uninitialized when used here [-Wconditional-uninitialized] > ../target/ppc/int_helper.c:2061:1: warning: variable 'result' may be > uninitialized when used here [-Wconditional-uninitialized] > ../target/ppc/int_helper.c:2062:1: warning: variable 'result' may be > uninitialized when used here [-Wconditional-uninitialized] > ../target/ppc/int_helper.c:2063:1: warning: variable 'result' may be > uninitialized when used here [-Wconditional-uninitialized] > ../target/ppc/int_helper.c:2064:1: warning: variable 'result' may be > uninitialized when used here [-Wconditional-uninitialized] > ../target/ppc/int_helper.c:2065:1: warning: variable 'result' may be > uninitialized when used here [-Wconditional-uninitialized] > ../target/ppc/int_helper.c:2066:1: warning: variable 'result' may be > uninitialized when used here [-Wconditional-uninitialized] > ../target/ppc/int_helper.c:2945:10: warning: variable 'result' may be > uninitialized when used here [-Wconditional-uninitialized] > ../target/ppc/int_helper.c:2956:10: warning: variable 'result' may be > uninitialized when used here [-Wconditional-uninitialized] > ../target/ppc/int_helper.c:2987:10: warning: variable 'result' may be > uninitialized when used here [-Wconditional-uninitialized] > ../target/ppc/int_helper.c:3063:10: warning: variable 'result' may be > uninitialized when used here [-Wconditional-uninitialized] > ../target/ppc/int_helper.c:967:1: warning: variable 'result' may be > uninitialized when used here [-Wconditional-uninitialized] > ../target/ppc/int_helper.c:968:1: warning: variable 'result' may be > uninitialized when used here [-Wconditional-uninitialized] > ../target/ppc/int_helper.c:969:1: warning: variable 'result' may be > uninitialized when used here [-Wconditional-uninitialized] > ../target/ppc/mmu-radix64.c:548:20: warning: variable 'pte' may be > uninitialized when used here [-Wconditional-uninitialized] > ../target/s390x/ioinst.c:364:52: warning: variable 'irb_len' may be > uninitialized when used here [-Wconditional-uninitialized] > ../target/s390x/tcg/mem_helper.c:2978:12: warning: variable 'cc' may > be uninitialized when used here [-Wconditional-uninitialized] > ../target/s390x/tcg/vec_fpu_helper.c:1023:26: warning: variable 'vxc' > may be uninitialized when used here [-Wconditional-uninitialized] > ../target/s390x/tcg/vec_fpu_helper.c:132:26: warning: variable 'vxc' > may be uninitialized when used here [-Wconditional-uninitialized] > ../target/s390x/tcg/vec_fpu_helper.c:156:26: warning: variable 'vxc' > may be uninitialized when used here [-Wconditional-uninitialized] > ../target/s390x/tcg/vec_fpu_helper.c:278:26: warning: variable 'vxc' > may be uninitialized when used here [-Wconditional-uninitialized] > ../target/s390x/tcg/vec_fpu_helper.c:301:26: warning: variable 'vxc' > may be uninitialized when used here [-Wconditional-uninitialized] > ../target/s390x/tcg/vec_fpu_helper.c:439:26: warning: variable 'vxc' > may be uninitialized when used here [-Wconditional-uninitialized] > ../target/s390x/tcg/vec_fpu_helper.c:471:26: warning: variable 'vxc' > may be uninitialized when used here [-Wconditional-uninitialized] > ../target/s390x/tcg/vec_fpu_helper.c:551:26: warning: variable 'vxc' > may be uninitialized when used here [-Wconditional-uninitialized] > ../target/s390x/tcg/vec_fpu_helper.c:592:26: warning: variable 'vxc' > may be uninitialized when used here [-Wconditional-uninitialized] > ../target/s390x/tcg/vec_fpu_helper.c:635:26: warning: variable 'vxc' > may be uninitialized when used here [-Wconditional-uninitialized] > ../target/s390x/tcg/vec_fpu_helper.c:659:26: warning: variable 'vxc' > may be uninitialized when used here [-Wconditional-uninitialized] > ../target/s390x/tcg/vec_fpu_helper.c:961:26: warning: variable 'vxc' > may be uninitialized when used here [-Wconditional-uninitialized] > ../target/s390x/tcg/vec_helper.c:189:25: warning: variable 'tmp' may > be uninitialized when used here [-Wconditional-uninitialized] > ../target/s390x/tcg/vec_helper.c:89:1: warning: variable 'tmp' may be > uninitialized when used here [-Wconditional-uninitialized] > ../target/s390x/tcg/vec_helper.c:90:1: warning: variable 'tmp' may be > uninitialized when used here [-Wconditional-uninitialized] > ../target/s390x/tcg/vec_helper.c:91:1: warning: variable 'tmp' may be > uninitialized when used here [-Wconditional-uninitialized] > ../target/s390x/tcg/vec_int_helper.c:556:25: warning: variable 'tmp' > may be uninitialized when used here [-Wconditional-uninitialized] > ../target/s390x/tcg/vec_int_helper.c:606:25: warning: variable 'tmp' > may be uninitialized when used here [-Wconditional-uninitialized] > ../target/xtensa/translate.c:1074:51: warning: variable 'resource' may > be uninitialized when used here [-Wconditional-uninitialized] > ../target/xtensa/translate.c:1092:35: warning: variable 'temp' may be > uninitialized when used here [-Wconditional-uninitialized] > ../target/xtensa/translate.c:936:72: warning: variable 'rf' may be > uninitialized when used here [-Wconditional-uninitialized] > ../target/xtensa/xtensa-semi.c:297:17: warning: variable 'rc' may be > uninitialized when used here [-Wconditional-uninitialized] > ../tests/fp/berkeley-softfloat-3/source/s_shiftRightJam256M.c:117:10: > warning: variable 'ptr' may be uninitialized when used here > [-Wconditional-uninitialized] > ../tests/fp/berkeley-testfloat-3/source/slowfloat.c:1015:13: warning: > variable 'uiZ' may be uninitialized when used here > [-Wconditional-uninitialized] > ../tests/fp/berkeley-testfloat-3/source/slowfloat.c:742:13: warning: > variable 'uiZ' may be uninitialized when used here > [-Wconditional-uninitialized] > ../tests/fp/berkeley-testfloat-3/source/slowfloat.c:878:13: warning: > variable 'uiZ' may be uninitialized when used here > [-Wconditional-uninitialized] > ../tests/qtest/boot-sector.c:169:21: warning: variable 'signature' may > be uninitialized when used here [-Wconditional-uninitialized] > ../tests/qtest/prom-env-test.c:43:21: warning: variable 'signature' > may be uninitialized when used here [-Wconditional-uninitialized] > ../tests/unit/test-bdrv-drain.c:1022:21: warning: variable 'ret' may > be uninitialized when used here [-Wconditional-uninitialized] > ../tests/unit/test-block-iothread.c:772:14: warning: variable 'job' > may be uninitialized when used here [-Wconditional-uninitialized] > ../ui/vnc-enc-tight.c:416:1: warning: variable 'ci' may be > uninitialized when used here [-Wconditional-uninitialized] > ../ui/vnc-enc-tight.c:417:1: warning: variable 'ci' may be > uninitialized when used here [-Wconditional-uninitialized] > ../ui/vnc-enc-tight.c:418:1: warning: variable 'ci' may be > uninitialized when used here [-Wconditional-uninitialized] > ../util/iov.c:469:52: warning: variable 'mid_head' may be > uninitialized when used here [-Wconditional-uninitialized] > ../util/iov.c:471:36: warning: variable 'mid_tail' may be > uninitialized when used here [-Wconditional-uninitialized] > ../util/qemu-timer.c:198:12: warning: variable 'expire_time' may be > uninitialized when used here [-Wconditional-uninitialized] > ../util/qemu-timer.c:236:13: warning: variable 'expire_time' may be > uninitialized when used here [-Wconditional-uninitialized] > ../util/qemu-timer.c:476:9: warning: variable 'rearm' may be > uninitialized when used here [-Wconditional-uninitialized] >
On Wed, 7 Dec 2022 at 18:44, Eric Auger <eric.auger@redhat.com> wrote: > On 12/7/22 19:23, Richard Henderson wrote: > > Adding -Wall is not standard, nor all the other -W that you are > > adding. I think you should not be surprised that you run into problems. > OK that's a useful indication. I used to have this configure cmd line > for a while and have not paid much attention to it until now, I > acknowledge. This was useful to catch compilation errors at some point I > guess. > > > > While you can make a case for auditing the code base and adding these > > to the default set of warning flags, that's a job for the next > > development cycle. > > Let me clarify, I am not insisting for that fix to land in 7.2 all the > more so it is pretty late. I just wanted to report the compilation issue > and since I use the std qemu pieces with a pretty standard tool chain I > thought somebody else would be likely to hit the same problem. As Richard says, we don't expect people to randomly add extra warning flags, and anybody who does should expect to see extra warnings (and that they need to --disable-werror if they don't want those extra warnings to turn into errors). We specifically disable some warnings, there are some not-on-by-default warnings that we know we have work to do if we want to eliminate them (eg -Wvla) and there's probably a few where we conceptually disagree with a warning flag or don't find it useful for QEMU (like -Wgnu-statement-expression -- we deliberately use GNU statement expressions so warning about them isn't useful to us). Sorting through which of the currently non-enabled warning flags are worth trying to fix existing warnings and enable by default is a pretty big task (not dissimilar to sorting through Coverity issue reports -- maybe some of the things you fix are real bugs but there's a lot of false-positives to wade through to get there). maybe-uninitialized warnings are particularly awkward because whether you get them depends a lot on the version of the compiler and how smart its data analysis is. thanks -- PMM
Hi Peter, On 12/7/22 21:28, Peter Maydell wrote: > On Wed, 7 Dec 2022 at 18:44, Eric Auger <eric.auger@redhat.com> wrote: >> On 12/7/22 19:23, Richard Henderson wrote: >>> Adding -Wall is not standard, nor all the other -W that you are >>> adding. I think you should not be surprised that you run into problems. >> OK that's a useful indication. I used to have this configure cmd line >> for a while and have not paid much attention to it until now, I >> acknowledge. This was useful to catch compilation errors at some point I >> guess. >>> While you can make a case for auditing the code base and adding these >>> to the default set of warning flags, that's a job for the next >>> development cycle. >> Let me clarify, I am not insisting for that fix to land in 7.2 all the >> more so it is pretty late. I just wanted to report the compilation issue >> and since I use the std qemu pieces with a pretty standard tool chain I >> thought somebody else would be likely to hit the same problem. > As Richard says, we don't expect people to randomly add extra > warning flags, and anybody who does should expect to see extra > warnings (and that they need to --disable-werror if they don't want > those extra warnings to turn into errors). > > We specifically disable some warnings, there are some not-on-by-default > warnings that we know we have work to do if we want to eliminate them > (eg -Wvla) and there's probably a few where we conceptually disagree > with a warning flag or don't find it useful for QEMU (like > -Wgnu-statement-expression -- we deliberately use GNU statement > expressions so warning about them isn't useful to us). > > Sorting through which of the currently non-enabled warning flags > are worth trying to fix existing warnings and enable by default > is a pretty big task (not dissimilar to sorting through Coverity > issue reports -- maybe some of the things you fix are real bugs > but there's a lot of false-positives to wade through to get there). > > maybe-uninitialized warnings are particularly awkward because whether > you get them depends a lot on the version of the compiler and how > smart its data analysis is. OK. I don't exactly remember how I came to this configure cmd line. Maybe in the old times bots were complaining about such kind of warnings or some of the extra warning flags were used downstream. I simply thought we had a stricter policy with regards to those and I have been using this configure command for a long time, without trouble, until recently, hence that belief. Thanks Eric > > thanks > -- PMM >
diff --git a/target/i386/ops_sse.h b/target/i386/ops_sse.h index 3cbc36a59d..b77071b8da 100644 --- a/target/i386/ops_sse.h +++ b/target/i386/ops_sse.h @@ -2451,7 +2451,7 @@ void glue(helper_vpgatherqq, SUFFIX)(CPUX86State *env, #if SHIFT >= 2 void helper_vpermdq_ymm(Reg *d, Reg *v, Reg *s, uint32_t order) { - uint64_t r0, r1, r2, r3; + uint64_t r0 = 0, r1 = 0, r2 = 0, r3 = 0; switch (order & 3) { case 0:
Initialize r0-3 to avoid compilation errors when -Werror=maybe-uninitialized is used ../target/i386/ops_sse.h: In function ‘helper_vpermdq_ymm’: ../target/i386/ops_sse.h:2495:13: error: ‘r3’ may be used uninitialized in this function [-Werror=maybe-uninitialized] 2495 | d->Q(3) = r3; | ~~~~~~~~^~~~ ../target/i386/ops_sse.h:2494:13: error: ‘r2’ may be used uninitialized in this function [-Werror=maybe-uninitialized] 2494 | d->Q(2) = r2; | ~~~~~~~~^~~~ ../target/i386/ops_sse.h:2493:13: error: ‘r1’ may be used uninitialized in this function [-Werror=maybe-uninitialized] 2493 | d->Q(1) = r1; | ~~~~~~~~^~~~ ../target/i386/ops_sse.h:2492:13: error: ‘r0’ may be used uninitialized in this function [-Werror=maybe-uninitialized] 2492 | d->Q(0) = r0; | ~~~~~~~~^~~~ Signed-off-by: Eric Auger <eric.auger@redhat.com> Fixes: 790684776861 ("target/i386: reimplement 0x0f 0x3a, add AVX") --- Am I the only one getting this? Or anything wrong in my setup. --- target/i386/ops_sse.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)