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

[Jan Beulich <jbeulich@xxxxxxxx>]

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.

Jan