Re: [PATCH] docs/misra: add 14.3 and 14.4

[Stefano Stabellini <sstabellini@xxxxxxxxxx>]

On Wed, 30 Aug 2023, Bertrand Marquis wrote:
> > On 30 Aug 2023, at 09:58, Jan Beulich <jbeulich@xxxxxxxx> wrote:
> > 
> > On 30.08.2023 09:54, Bertrand Marquis wrote:
> >>> On 30 Aug 2023, at 02:59, Stefano Stabellini <sstabellini@xxxxxxxxxx> 
> >>> wrote:
> >>> +   * - `Rule 14.4 
> >>> <https://gitlab.com/MISRA/MISRA-C/MISRA-C-2012/Example-Suite/-/blob/master/R_14_04.c>`_
> >>> +     - Required
> >>> +     - The controlling expression of an if statement and the controlling
> >>> +       expression of an iteration-statement shall have essentially
> >>> +       Boolean type
> >>> +     - Implicit conversions of integers, pointers, and chars to boolean
> >>> +       are allowed
> >> 
> >> I am a bit wondering here what is remaining after this deviation.
> > 
> > Hmm, good point - floating point (and alike) types, which we don't use 
> > anyway.
> 
> So we accept the rule but we deviate all cases that would apply.
> I do not think we should do that.

In the past we have been accepting rules that don't apply to Xen because
it is not much that they don't apply. It is that we have no violations
and we don't think there is any risk of getting violations in the
future.

But theoretically they apply, and for example if we end up with floating
points in Xen at some point in the future we would want rules affecting
floating points to apply, hence we accepted rules about floating points.

This rule is a bit different though: we deviate most of the rule and the
remaining part is small. In addition, we have no violations and we don't
think there is any risk of getting violations in the future for what's
left of the rule.

So I don't know if it is worth adding the rule or not. I think we should
ask Roberto next time. For now, I remove it from this patch.