Re: [PATCH] xen:add deviations for MISRA C 2012 Rule R5.2

[Stefano Stabellini <sstabellini@xxxxxxxxxx>]

On Wed, 13 Nov 2024, Jan Beulich wrote:
> On 13.11.2024 11:48, Alessandro Zucchelli wrote:
> > At this link you can see all the violations of Rule 5.2:
> > 
> > https://saas.eclairit.com:3787/fs/var/local/eclair/xen-project.ecdf/xen-project/people/bugseng/xen/ECLAIR_normal/40_characters/X86_64/8143097084/PROJECT.ecd;/by_service/MC3R1.R5.2.html
> 
> Thank you. From a cursory look these all appear to be a result of the 40
> chars limit we put in place (quite arbitrarily). That's not mentioned at
> all ...
> 
> > By deviating the two macros CHECK_NAME_ and DEFINE_COMPAT_HANDLE all the 
> > violations are addressed.
> > 
> > On 2024-11-13 11:31, Jan Beulich wrote:
> >> On 13.11.2024 09:41, Alessandro Zucchelli wrote:
> >>> This addresses violations of MISRA C:2012 Rule 5.2 which states as
> >>> following: Identifiers declared in the same scope and name space shall
> >>> be distinct.
> >>>
> >>> This deviation addresses violations of Rule 5.2 arising from
> >>> identifiers generated through token pasting macros CHECK_NAME_ and
> >>> DEFINE_COMPAT_HANDLE.
> 
> ... in the description.
> 
> Together with the 5.4 patch having the same lack of context, I wonder
> whether we shouldn't simply up that limit.

Yes: if we up to the limit to 64 (another arbitrary number), can be mark
both 5.4 and 5.1 as clean? If so, I think we should do it right away.


> Or else, as suggested there,
> to instead exclude such derived identifiers. After all the derived ones
> will be distinct as long as what they're derived from is distinct.
> 
> Finally - please don't top-post.
> 
> Jan
> 
> >> For each of the two, can you provide an example of where collisions
> >> result? At least for the latter I can't even see how that would
> >> work without the compiler complaining (i.e. the build breaking).