Re: [XEN PATCH] automation/eclair_analysis: fully deviate MISRA C Rules 21.9 and 21.10

[Stefano Stabellini <sstabellini@xxxxxxxxxx>]

On Wed, 15 May 2024, Nicola Vetrini wrote:
> These rules are concerned with the use of facilities provided by the
> C Standard Library (qsort, bsearch for rule 21.9, and those provided
> by <time.h> for rule 21.10).
> 
> Xen provides in its source code its own implementation of some of these
> functions and macros, therefore a justification is provided for allowing
> uses of these functions in the project.
> 
> The rules are also marked as clean as a consequence.
> 
> Signed-off-by: Nicola Vetrini <nicola.vetrini@xxxxxxxxxxx>

Reviewed-by: Stefano Stabellini <sstabellini@xxxxxxxxxx>


> ---
>  .../eclair_analysis/ECLAIR/deviations.ecl      | 14 ++++++++++++++
>  .../eclair_analysis/ECLAIR/monitored.ecl       |  2 ++
>  automation/eclair_analysis/ECLAIR/tagging.ecl  |  2 +-
>  docs/misra/deviations.rst                      | 18 ++++++++++++++++++
>  4 files changed, 35 insertions(+), 1 deletion(-)
> 
> diff --git a/automation/eclair_analysis/ECLAIR/deviations.ecl 
> b/automation/eclair_analysis/ECLAIR/deviations.ecl
> index 5eb7368a7322..1478c64a5af1 100644
> --- a/automation/eclair_analysis/ECLAIR/deviations.ecl
> +++ b/automation/eclair_analysis/ECLAIR/deviations.ecl
> @@ -477,6 +477,20 @@ leads to a violation of the Rule are deviated."
>  -config=MC3R1.R20.12,macros+={deliberate, 
> "name(GENERATE_CASE)&&loc(file(deliberate_generate_case))"}
>  -doc_end
>  
> +#
> +# Series 21.
> +#
> +
> +-doc_begin="Xen does not use the functions provided by the Standard Library, 
> but
> +implements a set of functions that share the same names as their Standard 
> Library equivalent.
> +The implementation of these functions is available in source form, so the 
> undefined, unspecified
> +or implementation-defined behaviors contemplated by the C Standard do not 
> apply.
> +If some undefined or unspecified behavior does arise in the implementation, 
> it
> +falls under the jurisdiction of other MISRA rules."
> +-config=MC3R1.R21.9,reports+={deliberate, "any()"}
> +-config=MC3R1.R21.10,reports+={deliberate, "any()"}
> +-doc_end
> +
>  #
>  # General
>  #
> diff --git a/automation/eclair_analysis/ECLAIR/monitored.ecl 
> b/automation/eclair_analysis/ECLAIR/monitored.ecl
> index 69308ea51c01..9da709dc889c 100644
> --- a/automation/eclair_analysis/ECLAIR/monitored.ecl
> +++ b/automation/eclair_analysis/ECLAIR/monitored.ecl
> @@ -36,12 +36,14 @@
>  -enable=MC3R1.R20.4
>  -enable=MC3R1.R20.9
>  -enable=MC3R1.R2.1
> +-enable=MC3R1.R21.10
>  -enable=MC3R1.R21.13
>  -enable=MC3R1.R21.17
>  -enable=MC3R1.R21.18
>  -enable=MC3R1.R21.19
>  -enable=MC3R1.R21.20
>  -enable=MC3R1.R21.21
> +-enable=MC3R1.R21.9
>  -enable=MC3R1.R2.2
>  -enable=MC3R1.R22.2
>  -enable=MC3R1.R22.4
> diff --git a/automation/eclair_analysis/ECLAIR/tagging.ecl 
> b/automation/eclair_analysis/ECLAIR/tagging.ecl
> index a14bda5033df..acea15f486a1 100644
> --- a/automation/eclair_analysis/ECLAIR/tagging.ecl
> +++ b/automation/eclair_analysis/ECLAIR/tagging.ecl
> @@ -19,7 +19,7 @@
>  
>  -doc_begin="Clean guidelines: new violations for these guidelines are not 
> accepted."
>  
> --service_selector={clean_guidelines_common, 
> "MC3R1.D1.1||MC3R1.D2.1||MC3R1.D4.1||MC3R1.D4.11||MC3R1.D4.14||MC3R1.R11.7||MC3R1.R11.9||MC3R1.R12.5||MC3R1.R1.1||MC3R1.R1.3||MC3R1.R1.4||MC3R1.R14.1||MC3R1.R16.7||MC3R1.R17.1||MC3R1.R17.3||MC3R1.R17.4||MC3R1.R17.5||MC3R1.R17.6||MC3R1.R20.13||MC3R1.R20.14||MC3R1.R20.4||MC3R1.R20.9||MC3R1.R21.13||MC3R1.R21.19||MC3R1.R21.21||MC3R1.R2.2||MC3R1.R22.2||MC3R1.R22.4||MC3R1.R22.5||MC3R1.R22.6||MC3R1.R2.6||MC3R1.R3.1||MC3R1.R3.2||MC3R1.R4.1||MC3R1.R4.2||MC3R1.R5.1||MC3R1.R5.2||MC3R1.R5.4||MC3R1.R5.6||MC3R1.R6.1||MC3R1.R6.2||MC3R1.R7.1||MC3R1.R7.2||MC3R1.R7.4||MC3R1.R8.1||MC3R1.R8.10||MC3R1.R8.12||MC3R1.R8.14||MC3R1.R8.2||MC3R1.R8.5||MC3R1.R8.6||MC3R1.R8.8||MC3R1.R9.2||MC3R1.R9.3||MC3R1.R9.4||MC3R1.R9.5"
> +-service_selector={clean_guidelines_common, 
> "MC3R1.D1.1||MC3R1.D2.1||MC3R1.D4.1||MC3R1.D4.11||MC3R1.D4.14||MC3R1.R11.7||MC3R1.R11.9||MC3R1.R12.5||MC3R1.R1.1||MC3R1.R1.3||MC3R1.R1.4||MC3R1.R14.1||MC3R1.R16.7||MC3R1.R17.1||MC3R1.R17.3||MC3R1.R17.4||MC3R1.R17.5||MC3R1.R17.6||MC3R1.R20.13||MC3R1.R20.14||MC3R1.R20.4||MC3R1.R20.9||MC3R1.R21.10||MC3R1.R21.13||MC3R1.R21.19||MC3R1.R21.21||MC3R1.R21.9||MC3R1.R2.2||MC3R1.R22.2||MC3R1.R22.4||MC3R1.R22.5||MC3R1.R22.6||MC3R1.R2.6||MC3R1.R3.1||MC3R1.R3.2||MC3R1.R4.1||MC3R1.R4.2||MC3R1.R5.1||MC3R1.R5.2||MC3R1.R5.4||MC3R1.R5.6||MC3R1.R6.1||MC3R1.R6.2||MC3R1.R7.1||MC3R1.R7.2||MC3R1.R7.4||MC3R1.R8.1||MC3R1.R8.10||MC3R1.R8.12||MC3R1.R8.14||MC3R1.R8.2||MC3R1.R8.5||MC3R1.R8.6||MC3R1.R8.8||MC3R1.R9.2||MC3R1.R9.3||MC3R1.R9.4||MC3R1.R9.5"
>  }
>  
>  -setq=target,getenv("XEN_TARGET_ARCH")
> diff --git a/docs/misra/deviations.rst b/docs/misra/deviations.rst
> index 161134771c77..b5450c38f66c 100644
> --- a/docs/misra/deviations.rst
> +++ b/docs/misra/deviations.rst
> @@ -411,6 +411,24 @@ Deviations related to MISRA C:2012 Rules:
>         construct is deviated only in Translation Units that present a 
> violation
>         of the Rule due to uses of this macro.
>       - Tagged as `deliberate` for ECLAIR.
> +     
> +   * - R21.9
> +     - Xen does not use the `bsearch` and `qsort` functions provided by the C
> +       Standard Library, but provides in source form its own implementation,
> +       therefore any unspecified or undefined behavior associated to the
> +       functions provided by the Standard Library does not apply. Any such
> +       behavior that may exist in such functions is therefore under the
> +       jurisdiction of other MISRA C rules.
> +     - Project-wide deviation, tagged as `deliberate` for ECLAIR.
> +
> +   * - R21.10
> +     - Xen does not use the facilities provided by the `\<time.h\>` provided 
> by the C
> +       Standard Library, but provides in source form its own implementation,
> +       therefore any unspecified, undefined or implementation-defined 
> behavior
> +       associated to the functions provided by the Standard Library does not
> +       apply. Any such behavior that may exist in such functions is therefore
> +       under the jurisdiction of other MISRA C rules.
> +     - Project-wide deviation, tagged as `deliberate` for ECLAIR.
>  
>  Other deviations:
>  -----------------
> -- 
> 2.34.1
>