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

[Stefano Stabellini <sstabellini@xxxxxxxxxx>]

On Thu, 21 Mar 2024, Jan Beulich wrote:
> On 21.03.2024 02:50, Stefano Stabellini wrote:
> > On Wed, 20 Mar 2024, Jan Beulich wrote:
> >> 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.*$&&context(ancestor_or_self(name(debugtrace_printk)&&kind(function))))"}
> >>
> >> This isn't concole output related.
> > 
> > Should we say "related to console output or tracing" ?
> > 
> > 
> >>> +-config=MC3R1.R17.1,reports+={deliberate,"any_area(^.*va_list.*$&&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.
> > 
> > Maybe it is better to write it as:
> > 
> > "Functions related printk, logging and tracing are allowed..."
> 
> How about simply saying "printf()-like functions"? In what you suggest,
> sprintf() and friends would still not be covered.

I like it