Re: [PATCH v3] misra: add deviations of MISRA C Rule 5.5

[Nicola Vetrini <nicola.vetrini@xxxxxxxxxxx>]

On 2025-07-31 09:15, Jan Beulich wrote:
> On 30.07.2025 23:39, Dmytro Prokopchuk1 wrote:
> > MISRA C Rule 5.5 states that: "Identifiers shall
> > be distinct from macro names".
> >
> > Update ECLAIR configuration to deviate clashes:
> > specify the macros that should be ignored.
> > Update deviations.rst and rules.rst accordingly.
> >
> > Signed-off-by: Dmytro Prokopchuk <dmytro_prokopchuk1@xxxxxxxx>
> Nit (along the lines of my comments on the other patch): Make better 
> use of line
> capacity here.
>
> > --- a/automation/eclair_analysis/ECLAIR/deviations.ecl
> > +++ b/automation/eclair_analysis/ECLAIR/deviations.ecl
> > @@ -117,6 +117,16 @@ it defines would (in the common case) be already 
> > defined. Peer reviewed by the c
> >  -config=MC3A2.R5.5,reports+={deliberate, 
> > "any_area(decl(kind(function))||any_loc(macro(name(memcpy||memset||memmove))))&&any_area(any_loc(file(^xen/common/libelf/libelf-private\\.h$)))"}
> >  -doc_end
> >
> > +-doc_begin="Clashes between bitops function and macro names are 
> > deliberate.
> > +These macros are needed for input validation and error handling."
> > +-config=MC3A2.R5.5,ignored_macros+="name(__test_and_set_bit||__test_and_clear_bit||__test_and_change_bit||test_bit||set_bit||clear_bit||change_bit||test_and_set_bit||test_and_clear_bit||test_and_change_bit)"
> > +-doc_end
> I have no idea whether regular expressions could be used here. If so, 
> shortening
> this at least some may be desirable.
It's possible, without using name(_):  e.g., 
ignored_macros+="^(__)?test_and_(set|clear|change)?_bit$
> > +-doc_begin="Clashes between grant table functions and macros names 
> > are deliberate.
> > +These macros address differences in argument count during 
> > compile-time, effectively discarding unused parameters to avoid 
> > warnings or errors related to them."
> > +-config=MC3A2.R5.5,ignored_macros+="name(update_gnttab_par||parse_gnttab_limit)"
> > +-doc_end
> No restriction to common/grant_table.c?
>
> > --- a/docs/misra/deviations.rst
> > +++ b/docs/misra/deviations.rst
> > @@ -142,6 +142,28 @@ Deviations related to MISRA C:2012 Rules:
> >         memmove.
> >       - Tagged as `deliberate` for ECLAIR.
> >
> > +   * - R5.5
> > +     - Clashes between bitops ('__test_and_set_bit', 
> > '__test_and_clear_bit',
> > +       '__test_and_change_bit', 'test_bit', 'set_bit', 'clear_bit', 
> > 'change_bit',
> > +       'test_and_set_bit', 'test_and_clear_bit', 
> > 'test_and_change_bit')
> > +       functions and macros names are deliberate and are needed for 
> > input
> Nit: "macro names"
>
> > +       validation and error handling, ensures that the size of the 
> > object being
> s/ensures/to ensure/ ?
>
> > +       pointed to by 'addr' meets the minimum requirements for the 
> > bit operation,
> 'addr' is pretty meaningless here.
>
> > +       preventing unsafe operations on improperly sized data types 
> > that could
> > +       lead to undefined behavior or memory corruption.
> > +       The macros encapsulate this conditional logic into a single, 
> > reusable form;
> > +       which simplifies the code, avoids redundant function call.
> What's "redundant" referring to here?
>
> > +       Also this bitops API was inherited from Linux and should be 
> > kept for familiarity.
> At least this line is clearly beyond 80 chars.
>
> Jan
--
Nicola Vetrini, B.Sc.
Software Engineer
BUGSENG (https://bugseng.com)
LinkedIn: https://www.linkedin.com/in/nicola-vetrini-a42471253