Re: [XEN PATCH 4/5] automation/eclair_analysis: address remaining violations of MISRA C Rule 20.12

[Nicola Vetrini <nicola.vetrini@bugseng.com>]

On 2024-06-03 20:52, Jan Beulich wrote:
> On 03.06.2024 09:13, Nicola Vetrini wrote:
>> On 2024-06-03 07:58, Jan Beulich wrote:
>>> On 01.06.2024 12:16, Nicola Vetrini wrote:
>>>> --- a/automation/eclair_analysis/ECLAIR/deviations.ecl
>>>> +++ b/automation/eclair_analysis/ECLAIR/deviations.ecl
>>>> @@ -483,6 +483,12 @@ 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
>>>> 
>>>> +-doc_begin="The macro DEFINE is defined and used in excluded files
>>>> asm-offsets.c.
>>>> +This may still cause violations if entities outside these files are
>>>> referred to
>>>> +in the expansion."
>>>> +-config=MC3R1.R20.12,macros+={deliberate,
>>>> "name(DEFINE)&&loc(file(asm_offsets))"}
>>>> +-doc_end
>>> 
>>> Can you give an example of such a reference? Nothing _in_ 
>>> asm-offsets.c
>>> should be referenced, I'd think. Only stuff in asm-offsets.h as
>>> _generated
>>> from_ asm-offsets.c will, of course, be.
>>> 
>> 
>> Perhaps I could have expressed that more clearly. What I meant is that
>> there are some arguments to DEFINE that are not part of asm-offsets.c,
>> therefore they end up in the violation report, but are not actually
>> relevant, because the macro DEFINE is actually what we want to 
>> exclude.
>> 
>> See for instance at the link below VCPU_TRAP_{NMI,MCE}, which are
>> defined in asm/domain.h and used as arguments to DEFINE inside
>> asm-offsets.c.
>> 
>> https://saas.eclairit.com:3787/fs/var/local/eclair/XEN.ecdf/ECLAIR_normal/staging/X86_64-BUGSENG/676/PROJECT.ecd;/by_service/MC3R1.R20.12.html
> 
> I'm afraid I still don't understand: The file being supposed to be
> excluded from scanning, why does it even show up in that report?
> 
> Jan

The report is made up of several source code locations. Three of them 
are within asm-offsets.c, which is excluded from compliance but still 
analyzed, but one references a macro definition in another file (e.g., 
VCPU_TRAP_NMI from asm/domain.h). So in this case the exclusion of 
asm-offsets.c is not enough for the report not to be shown.

The configuration is telling the tool that the macro DEFINE from 
asm-offsets is meant to be deviated, which is what is needed in this 
case.

-- 
Nicola Vetrini, BSc
Software Engineer, BUGSENG srl (https://bugseng.com)