Re: [PATCH v2] misra: add deviation of Rule 2.1 for BUG() macro

[Jan Beulich <jbeulich@xxxxxxxx>]

On 16.09.2025 21:35, Dmytro Prokopchuk1 wrote:
> 
> 
> On 9/16/25 17:27, Jan Beulich wrote:
>> On 16.09.2025 14:45, Dmytro Prokopchuk1 wrote:
>>> --- a/docs/misra/deviations.rst
>>> +++ b/docs/misra/deviations.rst
>>> @@ -98,6 +98,23 @@ Deviations related to MISRA C:2012 Rules:
>>>          even when debug-only assertions like `ASSERT_UNREACHABLE()` are 
>>> removed.
>>>        - ECLAIR has been configured to ignore those statements.
>>>   
>>> +   * - R2.1
>>> +     - In the specific build configuration (when the config CONFIG_ACPI is 
>>> not
>>> +       defined) the 'BUG()' macro is intentionally used in the 
>>> 'prepare_acpi()'
>>> +       function in the header file 
>>> 'xen/arch/arm/include/asm/domain_build.h'
>>> +       defined as 'static inline' to trigger a runtime error if 
>>> ACPI-related
>>> +       features are used incorrectly.
>>> +     - Tagged as `deliberate` for ECLAIR.
>>
>> I response to me outlining a deviation-less alternative you tried it out
>> and said it works. Then why is the deviation still being put in place?
> 
> Yes, that's true.
> I started with that prepare_acpi() function and I tried to move it into 
> xen/include/xen/acpi.h header file under appropriate #ifdef:
> https://gitlab.com/xen-project/people/dimaprkp4k/xen/-/commit/d15cf91de92f1f8ec67911c51a13e7f095c1bcdd

But an important part of my proposal was to have no #ifdef around
the declaration, iirc. With that, no violation should result.
Whether (or why) moving would be required I don't know.

Jan