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

[Jacob Keller <jacob.e.keller@intel.com>]

On 3/7/2025 12:53 PM, Jacob Keller wrote:
> 
> 
> On 3/7/2025 2:47 AM, Markus Elfring wrote:
>>> 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
>> + )
>>   , ...
>>  );
>>
> 
For what its worth, I was finally able to get things working pretty much
the same as before with the following semantic patches:

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


and

> @disable drop_cast@
> void * void_ptr;
> type T;
> @@
> -(T *)void_ptr
> +void_ptr

These seem to properly apply with both 1.2.0 and 1.3.0, and mostly
handle the white spacing properly. There were exactly 2 places where I
ended up having to re-arrange the original code slightly having to do
with constructions like:

type ptr =
   (type)value

where the original version would have replaced the entire line and
cleaned things up to fit. These were easy enough to fix up on my end.

As a bonus, this caught several missed typecasts of function arguments,
as well as some assignments that the original hadn't caught for some reason.

I think this change should be acceptable on our end and we don't need to
worry about fixes to spatch. Again, I re-tested both 1.3.0 and 1.2.0 and
get the same behavior now.

Appreciate the suggestions and especially the work you guys do on this tool!

Thanks,
Jake