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

[Jan Beulich <jbeulich@xxxxxxxx>]

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.

> +-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