On 06/10/2023 21.08, Warner Losh wrote:
On Fri, Oct 6, 2023, 11:55 AM Thomas Huth <th...@redhat.com
<mailto:th...@redhat.com>> wrote:
On 06/10/2023 18.18, Thomas Huth wrote:
> On 06/10/2023 16.45, Markus Armbruster wrote:
>> Local variables shadowing other local variables or parameters make the
>> code needlessly hard to understand. Bugs love to hide in such code.
>> Evidence: "[PATCH v3 1/7] migration/rdma: Fix save_page method to fail
>> on polling error".
>>
>> Enabling -Wshadow would prevent bugs like this one. But we have to
>> clean up all the offenders first.
>>
>> Quite a few people responded to my calls for help. Thank you so much!
>>
>> I'm collecting patches in my git repo at
>> https://repo.or.cz/qemu/armbru.git
<https://repo.or.cz/qemu/armbru.git> in branch shadow-next. All but the
>> last two are in a pending pull request.
>>
>> My test build is down to seven files with warnings. "[PATCH v2 0/3]
>> hexagon: GETPC() and shadowing fixes" takes care of four, but it needs a
>> rebase.
>>
>> Remaining three:
>>
>> In file included from ../hw/display/virtio-gpu-virgl.c:19:
>> ../hw/display/virtio-gpu-virgl.c: In function
‘virgl_cmd_submit_3d’:
>> /work/armbru/qemu/include/hw/virtio/virtio-gpu.h:228:16: warning:
>> declaration of ‘s’ shadows a previous local [-Wshadow=compatible-local]
>> 228 | size_t
>> s; \
>> | ^
>> ../hw/display/virtio-gpu-virgl.c:215:5: note: in expansion of
macro
>> ‘VIRTIO_GPU_FILL_CMD’
>> 215 | VIRTIO_GPU_FILL_CMD(cs);
>> | ^~~~~~~~~~~~~~~~~~~
>> ../hw/display/virtio-gpu-virgl.c:213:12: note: shadowed
declaration
>> is here
>> 213 | size_t s;
>> | ^
>>
>> In file included from ../contrib/vhost-user-gpu/virgl.h:18,
>> from ../contrib/vhost-user-gpu/virgl.c:17:
>> ../contrib/vhost-user-gpu/virgl.c: In function
‘virgl_cmd_submit_3d’:
>> ../contrib/vhost-user-gpu/vugpu.h:167:16: warning: declaration
of ‘s’
>> shadows a previous local [-Wshadow=compatible-local]
>> 167 | size_t
>> s; \
>> | ^
>> ../contrib/vhost-user-gpu/virgl.c:203:5: note: in expansion of
macro
>> ‘VUGPU_FILL_CMD’
>> 203 | VUGPU_FILL_CMD(cs);
>> | ^~~~~~~~~~~~~~
>> ../contrib/vhost-user-gpu/virgl.c:201:12: note: shadowed
declaration
>> is here
>> 201 | size_t s;
>> | ^
>>
>> ../contrib/vhost-user-gpu/vhost-user-gpu.c: In function
>> ‘vg_resource_flush’:
>> ../contrib/vhost-user-gpu/vhost-user-gpu.c:837:29: warning:
>> declaration of ‘i’ shadows a previous local [-Wshadow=local]
>> 837 | pixman_image_t *i =
>> | ^
>> ../contrib/vhost-user-gpu/vhost-user-gpu.c:757:9: note: shadowed
>> declaration is here
>> 757 | int i;
>> | ^
>>
>> Gerd, Marc-André, or anybody else?
>>
>> More warnings may lurk in code my test build doesn't compile. Need a
>> full CI build with -Wshadow=local to find them. Anybody care to kick
>> one off?
>
> I ran a build here (with -Werror enabled, so that it's easier to see
where
> it breaks):
>
> https://gitlab.com/thuth/qemu/-/pipelines/1028023489
<https://gitlab.com/thuth/qemu/-/pipelines/1028023489>
>
> ... but I didn't see any additional spots in the logs beside the ones
that
> you already listed.
After adding two more patches to fix the above warnings, things look pretty
good:
https://gitlab.com/thuth/qemu/-/pipelines/1028413030
<https://gitlab.com/thuth/qemu/-/pipelines/1028413030>
There are just some warnings left in the BSD code, as Warner already
mentioned in his reply to v2 of your mail:
https://gitlab.com/thuth/qemu/-/jobs/5241420713
<https://gitlab.com/thuth/qemu/-/jobs/5241420713>
I think I have fixes for these. I need to merge what just landed into
bsd-user fork, rebase, test, the apply them to qemu master branch, retest
and send them off...
My illness has hung on longer than I thought so I'm still behind...
Get well soon again! ... and no worries about the -Wshadow=local patches in
the BSD code, there is no hurry - The BSDs are using Clang by default, so
that option won't get enabled by default there anyway yet - I had to switch
to GCC in the CI pipeline to trigger those, and I guess only very few people
will use GCC to compile QEMU on FreeBSD.
Thomas
