Re: [cocci] behavior change in semantic patches since c36b51ffc889 …

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

> I also noticed a behavior change in another patch:
>
>> @@
>> expression hw, ptr;
>> @@
>> (
>> - ice_free(hw, ptr);
>> + devm_kfree(ice_hw_to_dev(hw),ptr);
>> )
>
> This patch updates some code that used an internal wrapper function to
> use the appropriate kernel function directly.

Would you like to experiment with another transformation approach?


@replacement@
expression hw;
@@
-ice_free
+devm_kfree
 (
+ ice_hw_to_dev(
  hw
+ )
  , ...
 );


> When the function is inside a block like this, it is transformed to
> include braces. This often violates our style guide as braces around
> single line if or other scopes are not desired.

I became also curious how the support can be improved for source code
analyses and transformations according to compound statements.


> I ran a git bisect to determine when these changes broke, and both
> changes appear to occur due to the following change:

Would you like to share any commands and related background information?


> I was using spatch --parse-cocci and saw some warnings about the patch
> file, and refactored it to:
>
> @disable drop_cast@
> void * void_ptr;
> type T;
> T * typed_ptr;
> @@
>  typed_ptr =
> -(T *)
>  void_ptr

I find it interesting that you tried also an SmPL script variant out
with a better change precision.


> This fixed so that the patch does find all the typecasts, but has often
> left us with undesirable white spacing, …

Will development interests grow for topics like the following?

* Advanced data processing for whitespace characters
  2016-01-12
  https://github.com/coccinelle/coccinelle/issues/58

* Fix indentation algorithm for Linux coding style
  2016-08-29
  https://github.com/coccinelle/coccinelle/issues/75

* Fix usage of white-space characters at two places for Linux coding style
  2016-08-29
  https://github.com/coccinelle/coccinelle/issues/76

* Preserve selected whitespace characters (for Linux coding style)
  2025-02-28
  https://github.com/coccinelle/coccinelle/issues/392


Regards,
Markus