On 25/02/2026 12:35 pm, Nicola Vetrini wrote: > On 2026-02-25 13:14, Andrew Cooper wrote: >> On 23/02/2026 7:26 am, Roberto Bagnara wrote: >>> >>> Note that in recent versions of MISRA C that rule is no longer >>> mandatory. More generally, note also that, IMHO, switching to >>> a more modern version of MISRA C would simplify compliance. >> >> Ok. Making things simpler for compliance sounds like a good thing. >> What would this entail? >> >> Presumably we've got to adapt to all changes in this newer revision of >> MISRA C. >> >> ~Andrew > > Most likely new violations on new non-clean guidelines, generally > rules for features that were standardized in C11/C18 and were > previously widely available extensions (e.g. _Noreturn, _Alignof, > threads, ...),
We use noreturn a lot, and alignof() a little. No threading at all (well - not as C understands it). > alongside some minor changes in existing ones, such as the > classification change mentioned by Roberto. The exact impact depends > on the target MISRA revision, however. Making an experiment should be > only a matter of s/MC3A2/MC4/ (or whichever MISRA revision is chosen: > MC4 in ECLAIR refers to the latest published MISRA revision, that is, > MISRA C:2025. Perhaps also a few regressions (as in newly introduced > violations) on clean ones, but I do not expect the results to be > radically different. > > Side note here: are the efforts to make Xen compile with > -stc=c11/gnu11 still ongoing? I say this because any MISRA revision > other than the one currently used by Xen by default is based on C11, > as it introduces guidelines for C11/C18 features. Not that this would > matter a whole lot for Xen, but it is something to consider in the > broader picture. > Funny you should ask. I had a paragraph about it in my reply but dropped it, thinking it was getting off track. https://gitlab.com/xen-project/xen/-/issues/201 I've just updated it to note that we did start using auto, by way of the __auto_type language extension. >From the Xen side, switching to gnu11 is a one-line change. However "ongoing" is really just me in my copious free time, and I'm not able to do the ECLAIR/MISRA config side of the work. It sounds to me like we want a dedicated work item switch to gnu11 and some newer MISRA revision, but I will have to defer to you on how large a task this is. I suppose we should start with an experiment to see what shows up in the *-amd target builds, and go from there? ~Andrew
