Re: [cocci] Reconsidering selected SmPL code

[Markus Elfring <Markus.Elfring@web.de>]

>> I'm starting to realize I should document my set of "with cocci, how do
>> I ...?" answers somewhere.
> Okay, initial dump is here:
>
> https://github.com/kees/kernel-tools/tree/trunk/coccinelle

I suggest to reconsider published implementation details a bit more.
https://github.com/kees/kernel-tools/blob/0d128055b31a7737eaa23c040e57a0f34a41e6c1/coccinelle/README.md#user-content-use-regular-expressions-to-quickly-match-identifiers


@display_with_regex@
identifier func =~ "^(?:get_random_(?:int|u32)|prandom_u32)$";
@@
*func
 ()


@display_with_disjunction@
@@
(
*get_random_int
|
*get_random_u32
|
*prandom_u32
)
 ()


Would you like to compare software run time characteristics in more detail?


https://github.com/kees/kernel-tools/blob/0d128055b31a7737eaa23c040e57a0f34a41e6c1/coccinelle/README.md#user-content-limit-matches-when-variable-contents-arent-used-again

I propose to take additional SmPL script design options into account.


https://github.com/kees/kernel-tools/blob/0d128055b31a7737eaa23c040e57a0f34a41e6c1/coccinelle/README.md#user-content-match-variables-of-a-given-type

Will further collateral evolution happen according to mentioned metavariable declarations?


https://github.com/kees/kernel-tools/blob/246d5fe3c1abf0a25778acc5d3b8af02511241b0/coccinelle/examples/rand-pass2.cocci#L1

I wonder why the source code search pattern “prandom_bytes(...)@p” was not used for the SmPL rule “hit”.

I imagine that the addition of constraints for metavariables with
the type “binary operator” can help to avoid duplicate code in related SmPL rules.


Regards,
Markus