Re: [XEN PATCH 1/2] automation/eclair: add deviation for MISRA C:2012 Rule 17.1

[Jan Beulich <jbeulich@xxxxxxxx>]

On 20.03.2024 09:50, Simone Ballarin wrote:
> MISRA C:2012 Rule 17.1 states:
> The features of `<stdarg.h>' shall not be used
> 
> The Xen community wants to avoid using variadic functions except for
> specific circumstances where it feels appropriate by strict code review.
> 
> Add deviation for functions related to console output (printk and similar).
> 
> Signed-off-by: Simone Ballarin <simone.ballarin@xxxxxxxxxxx>
> ---
>  .../eclair_analysis/ECLAIR/deviations.ecl     | 26 +++++++++++++++++++
>  docs/misra/deviations.rst                     |  5 ++++
>  2 files changed, 31 insertions(+)
> 
> diff --git a/automation/eclair_analysis/ECLAIR/deviations.ecl 
> b/automation/eclair_analysis/ECLAIR/deviations.ecl
> index 9ac3ee4dfd..7c3559a3a0 100644
> --- a/automation/eclair_analysis/ECLAIR/deviations.ecl
> +++ b/automation/eclair_analysis/ECLAIR/deviations.ecl
> @@ -382,6 +382,32 @@ explicit comment indicating the fallthrough intention is 
> present."
>  -config=MC3R1.R16.6,switch_clauses+={deliberate, "default(0)"}
>  -doc_end
>  
> +#
> +# Series 17.
> +#
> +
> +-doc_begin="Functions related to console output are allowed to use the 
> variadic features provided by stdarg.h."
> +-config=MC3R1.R17.1,reports+={deliberate,"any_area(^.*va_list.*$&&context(ancestor_or_self(name(debugtrace_printk)&&kind(function))))"}

This isn't concole output related.

> +-config=MC3R1.R17.1,reports+={deliberate,"any_area(^.*va_list.*$&&context(ancestor_or_self(name(dt_dprintk)&&kind(function))))"}
> +-config=MC3R1.R17.1,reports+={deliberate,"any_area(^.*va_list.*$&&context(ancestor_or_self(name(printk)&&kind(function))))"}
> +-config=MC3R1.R17.1,reports+={deliberate,"any_area(^.*va_list.*$&&context(ancestor_or_self(name(guest_printk)&&kind(function))))"}
> +-config=MC3R1.R17.1,reports+={deliberate,"any_area(^.*va_list.*$&&context(ancestor_or_self(name(panic)&&kind(function))))"}
> +-config=MC3R1.R17.1,reports+={deliberate,"any_area(^.*va_list.*$&&context(ancestor_or_self(name(dprintk)&&kind(function))))"}
> +-config=MC3R1.R17.1,reports+={deliberate,"any_area(^.*va_list.*$&&context(ancestor_or_self(name(gdprintk)&&kind(function))))"}
> +-config=MC3R1.R17.1,reports+={deliberate,"any_area(^.*va_list.*$&&context(ancestor_or_self(name(snprintf)&&kind(function))))"}
> +-config=MC3R1.R17.1,reports+={deliberate,"any_area(^.*va_list.*$&&context(ancestor_or_self(name(scnprintf)&&kind(function))))"}
> +-config=MC3R1.R17.1,reports+={deliberate,"any_area(^.*va_list.*$&&context(ancestor_or_self(name(xasprintf)&&kind(function))))"}

These three and ...

> +-config=MC3R1.R17.1,reports+={deliberate,"any_area(^.*va_list.*$&&context(ancestor_or_self(name(mm_printk)&&kind(function))))"}
> +-config=MC3R1.R17.1,reports+={deliberate,"any_area(^.*va_list.*$&&context(ancestor_or_self(name(dbgp_printk)&&kind(function))))"}
> +-config=MC3R1.R17.1,reports+={deliberate,"any_area(^.*va_list.*$&&context(ancestor_or_self(name(elf_call_log_callback)&&kind(function))))"}
> +-config=MC3R1.R17.1,reports+={deliberate,"any_area(^.*va_list.*$&&context(ancestor_or_self(name(vsnprintf)&&kind(function))))"}
> +-config=MC3R1.R17.1,reports+={deliberate,"any_area(^.*va_list.*$&&context(ancestor_or_self(name(vscnprintf)&&kind(function))))"}
> +-config=MC3R1.R17.1,reports+={deliberate,"any_area(^.*va_list.*$&&context(ancestor_or_self(name(xvasprintf)&&kind(function))))"}

... these three aren't either.

> +-config=MC3R1.R17.1,reports+={deliberate,"any_area(^.*va_list.*$&&context(ancestor_or_self(name(vprintk_common)&&kind(function))))"}
> +-config=MC3R1.R17.1,reports+={deliberate,"any_area(^.*va_list.*$&&context(ancestor_or_self(name(guest_printk)&&kind(function))))"}
> +-config=MC3R1.R17.1,macros+={hide , "^va_(arg|start|copy|end)$"}
> +-doc_end

Further, is there a reason xyzprintk() are all listed individually?
Surely if we'd introduce a new flavor, we'd want that excluded too.

Finally, {,g}dprintk() in neither of their incarnation use any of the
va_* items listed. Why do they need mentioning here?

Jan