Re: [XEN PATCH 5/5] xen: fix MISRA regressions on rule 20.9 and 20.12

[Andrew Cooper <andrew.cooper3@xxxxxxxxxx>]

On 01/06/2024 1:58 pm, Nicola Vetrini wrote:
> On 2024-06-01 14:47, Andrew Cooper wrote:
>> On 01/06/2024 11:16 am, Nicola Vetrini wrote:
>>> ea59e7d780d9 ("xen/bitops: Cleanup and new infrastructure ahead of
>>> rearrangements")
>>> introduced new violations on previously clean rules 20.9 and 20.12.
>>>
>>> The first is introduced because CONFIG_CC_IS_CLANG in
>>> xen/self-tests.h is not
>>> defined in the configuration under analysis. Using "defined()"
>>> instead avoids
>>> relying on the preprocessor's behaviour upon encountering an
>>> undedfined identifier
>>> and addresses the violation.
>>>
>>> The violation of Rule 20.12 is due to "val" being used both as an
>>> ordinary argument
>>> in macro RUNTIME_CHECK, and as a stringification operator.
>>>
>>> No functional change.
>>>
>>> Fixes: ea59e7d780d9 ("xen/bitops: Cleanup and new infrastructure
>>> ahead of rearrangements")
>>> Signed-off-by: Nicola Vetrini <nicola.vetrini@xxxxxxxxxxx>
>>
>> Thankyou for this patch.  I'd seen that I'd broken something.  (Entirely
>> my fault - I've done a lot of testing in Gitlab for the series, but
>> never manually ran the Eclair jobs.  I'll try to remember better next
>> time.)
>>
>> One question though. 
>> https://gitlab.com/xen-project/xen/-/jobs/6994213979 says:
>>
>> Failure: 1 regressions found for clean guidelines
>>   service MC3R1.R20.9: (required) All identifiers used in the
>> controlling expression of `#if' or `#elif' preprocessing directives
>> shall be #define'd before evaluation:
>>    violation: 1
>>
>> While there is a report for 20.12, it's not clean yet (so the first
>> sentence wants adjusting), and RUNTIME_CHECK doesn't show up newly in
>> it.
>>
>> So, while I agree that RUNTIME_CHECK() should be included in the 20.12
>> exclusions, why is current Gitlab Run not reporting it?
>>
>> ~Andrew
>
> While Rule 20.12 wasn't clean on x86, but it was on arm, so in the
> arm64 run it is reported as such
>
> https://gitlab.com/xen-project/xen/-/jobs/6994213980
>
> with the other patches in the series the rule should be clean on both
> architectures, so this imbalance should disappear rather shortly.
>

Thanks - I'd just found the ARM report and was replying - I'll rebase
onto this thread.

I still don't understand why the violation doesn't show up on the x86
build.  Specifically, why it's missing from here:
https://saas.eclairit.com:3787/fs/var/local/eclair/xen-project.ecdf/xen-project/xen/ECLAIR_normal/staging/X86_64/6994213979/prev/PROJECT.ecd;/by_service/MC3R1.R20.12.html

>From the ARM report, one is xen/lib/generic-ffsl.c:61 and checking with
the x86 build log, we are building generic-ffsl.c too (which is expected.)

~Andrew