Hi, > On 30 May 2022, at 11:21, George Dunlap <[email protected]> wrote: > > > >> On 30 May 2022, at 10:55, Jan Beulich <[email protected]> wrote: >> >> On 30.05.2022 11:41, Julien Grall wrote: >>> >>> >>> On 30/05/2022 10:33, Jan Beulich wrote: >>>> On 30.05.2022 11:27, Julien Grall wrote: >>>>> Hi, >>>>> >>>>> On 30/05/2022 10:16, Jan Beulich wrote: >>>>>> On 30.05.2022 11:12, Julien Grall wrote: >>>>>>> On 28/05/2022 00:16, Stefano Stabellini wrote: >>>>>>>> """ >>>>>>>> It is possible that in specific circumstances it is best not to follow >>>>>>>> a >>>>>>>> rule because it is not possible or because the alternative leads to >>>>>>>> better code quality. Those cases are called "deviations". They are >>>>>>>> permissible as long as they are documented, either as an in-code >>>>>>>> comment >>>>>>>> or as part of the commit message. Other documentation mechanisms are >>>>>>> >>>>>>> I would drop the "as part of the commit message" because it is a lot >>>>>>> more difficult to associate the deviation with a rationale (the code may >>>>>>> have been moved and you would need to go through the history). >>>>>> >>>>>> But this was added in response to me pointing out that code comments >>>>>> aren't standardized yet as to their format. The alternative, as said >>>>>> before, would be to come up with a scheme first, before starting to >>>>>> mandate playing by certain of the rules (and hence requiring deviations >>>>>> to be documented). >>>>> >>>>> I don't think this is necessary short term. It is easy to rework a >>>>> comment after the fact. It is a lot more difficult to go through the >>>>> history and find the rationale. >>>> >>>> We all know what "short term" may mean - we may remain in this mode of >>>> operation for an extended period of time. It'll potentially be quite a >>>> bit of churn to subsequently adjust all such comments which would >>>> have accumulated, and - for not being standardized - can't easily be >>>> grep-ed for. >>> >>> Well... Scanner will likely point out the issues we deviate from. So you >>> we have an easy way to know where the comments need to be adjusted. >>> >>>> By documenting things in the commit message the state of >>>> the code base doesn't change, and we'll continue to rely on scanners >>>> to locate sets of candidates for adjustment or deviation commentary. >>> >>> The part I am missing how documenting the deviations in the commit >>> message help... Can you clarify it? >> >> I understood Stefano for this to merely be for the purpose of justifying >> the deviation (preempting review comments). > > Right, so at a very minimum, if we say “This is a rule now”, and a submitter > wants a deviation from that rule, then the reviewer needs to know the > justification for the deviation. The commit message is the obvious place for > that.
Agree > > Obviously something *else* we might want is a more convenient way to keep > that rationale for the future, when we start to officially document > deviations. Given that the scanner will point out all the places where > deviations happen, I don’t think an unstructured comment with an informal > summary of the justification would be a problem — it seems like it would be a > lot easier, when we start to officially document deviations, to transform > comments in the existing codebase, than to search through the mailing lists > and/or git commit history to find the rationale (or try to work out unaided > what the intent was). But I don’t have strong opinions on the matter. Maybe agreeing on a simple tag to start that can later be improved (Luca Fancellu on my side will start working on that with the FuSa SIG and Eclair next month). So I would suggest: /** * MISRA_DEV: Rule ID * xxxxx justification * */ Whenever we will have defined the final way, we will replace those entries with the new system. Would that be an agreeable solution ? Regards Bertrand > > -George
