Re: [PATCH for 7.2?] target/i386: Remove compilation errors when -Werror=maybe-uninitialized

[Eric Auger]

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
>