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

[Bertrand Marquis <Bertrand.Marquis@xxxxxxx>]

Hi Stefano,

> On 30 Aug 2023, at 02:59, Stefano Stabellini <sstabellini@xxxxxxxxxx> wrote:
> 
> From: Stefano Stabellini <stefano.stabellini@xxxxxxx>
> 
> Add 14.3, with a project-wide deviations on if statements.
> Add 14.4, clarifying that implicit conversions of integers, chars and
> pointers to bool are allowed.
> 
> Also take the opportunity to clarify that parameters of function pointer
> types are expected to have names (Rule 8.2).
> 
> Signed-off-by: Stefano Stabellini <stefano.stabellini@xxxxxxx>
> ---
> docs/misra/rules.rst | 20 +++++++++++++++++++-
> 1 file changed, 19 insertions(+), 1 deletion(-)
> 
> diff --git a/docs/misra/rules.rst b/docs/misra/rules.rst
> index db30632b93..6cde4feeae 100644
> --- a/docs/misra/rules.rst
> +++ b/docs/misra/rules.rst
> @@ -234,7 +234,7 @@ maintainers if you want to suggest a change.
>    * - `Rule 8.2 
> <https://gitlab.com/MISRA/MISRA-C/MISRA-C-2012/Example-Suite/-/blob/master/R_08_02.c>`_
>      - Required
>      - Function types shall be in prototype form with named parameters
> -     -
> +     - Function pointer types shall have named parameters too.


I would just modify to Function and Function pointers types shall be ...

> 
>    * - `Rule 8.3 
> <https://gitlab.com/MISRA/MISRA-C/MISRA-C-2012/Example-Suite/-/blob/master/R_08_03.c>`_
>      - Required
> @@ -332,6 +332,24 @@ maintainers if you want to suggest a change.
>      - A loop counter shall not have essentially floating type
>      -
> 
> +   * - `Rule 14.3 
> <https://gitlab.com/MISRA/MISRA-C/MISRA-C-2012/Example-Suite/-/blob/master/R_14_03.c>`_
> +     - Required
> +     - Controlling expressions shall not be invariant
> +     - Due to the extensive usage of IS_ENABLED, sizeof compile-time
> +       checks, and other constructs that are detected as errors by MISRA
> +       C scanners, managing the configuration of a MISRA C scanner for
> +       this rule would be unmanageable. Thus, this rule is adopted with
> +       a project-wide deviation on 'if' statements. The rule only
> +       applies to while, for, do ... while, ?:, and switch statements.

Didn't we also said that we would accept while(0) and while(1) ?
Also i agree with Jan, ? is really the same as if so we should not treat it 
differently.

> +
> +   * - `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.

> +
>    * - `Rule 16.7 
> <https://gitlab.com/MISRA/MISRA-C/MISRA-C-2012/Example-Suite/-/blob/master/R_16_07.c>`_
>      - Required
>      - A switch-expression shall not have essentially Boolean type
> -- 
> 2.25.1
> 

Cheers
Bertrand