Re: [PATCH] docs/misra: add R13.2 and R18.2 to rules.rst

[Stefano Stabellini <sstabellini@xxxxxxxxxx>]

On Thu, 1 Aug 2024, Bertrand Marquis wrote:
> Hi Stefano,
> 
> > On 1 Aug 2024, at 01:50, Stefano Stabellini <sstabellini@xxxxxxxxxx> wrote:
> > 
> > On Wed, 31 Jul 2024, Jan Beulich wrote:
> >> On 31.07.2024 01:30, Stefano Stabellini wrote:
> >>> --- a/docs/misra/rules.rst
> >>> +++ b/docs/misra/rules.rst
> >>> @@ -462,6 +462,15 @@ maintainers if you want to suggest a change.
> >>>      - Initializer lists shall not contain persistent side effects
> >>>      -
> >>> 
> >>> +   * - `Rule 13.2 
> >>> <https://gitlab.com/MISRA/MISRA-C/MISRA-C-2012/Example-Suite/-/blob/master/R_13_02.c>`_
> >>> +     - Required
> >>> +     - The value of an expression and its persistent side-effects shall
> >>> +       be the same under all permitted evaluation orders
> >>> +     - Be aware that the static analysis tool Eclair might report
> >>> +       several findings for Rule 13.2 of type "caution". These are
> >>> +       instances where Eclair is unable to verify that the code is valid
> >>> +       in regard to Rule 13.2. Caution reports are not violations.
> >> 
> >> Which doesn't make clear what our take is towards new code people may
> >> submit.
> > 
> > Good point, see my comment below
> > 
> > 
> >>> @@ -583,6 +592,15 @@ maintainers if you want to suggest a change.
> >>>        submitting new patches please try to decrease the number of
> >>>        violations when possible.
> >>> 
> >>> +   * - `Rule 18.2 
> >>> <https://gitlab.com/MISRA/MISRA-C/MISRA-C-2012/Example-Suite/-/blob/master/R_18_02.c>`_
> >>> +     - Required
> >>> +     - Subtraction between pointers shall only be applied to pointers
> >>> +       that address elements of the same array
> >>> +     - Be aware that the static analysis tool Eclair might report
> >>> +       several findings for Rule 18.2 of type "caution". These are
> >>> +       instances where Eclair is unable to verify that the code is valid
> >>> +       in regard to Rule 18.2. Caution reports are not violations.
> >> 
> >> And while the same wording is used here, I think it is pretty clear for
> >> this that we'd reject changes where bad subtractions are used. IOW even
> >> more so important to clarify the (possibly different) positions on what
> >> is going to be added into the code base.
> > 
> > In both of these cases, we would reject code that doesn't follow R13.2
> > and R18.2. I'll change it to the following:
> > 
> > 
> > Be aware that the static analysis tool Eclair might report several
> > findings for Rule 18.2 of type "caution". These are instances where
> > Eclair is unable to verify that the code is valid in regard to Rule
> > 18.2. Caution reports are not violations. Regardless, new code is
> > expected to follow this rule.
> 
> I think that in both cases it is wrong to state that "cautions reported are
> not violations" where those are cases where the tool is not sure so they
> might be or not violations.
> So I would change the sentence to "cautions might not be violations. The
> rule should be followed in any case in new code submitted".

I am happy with your wording, I'll make the change