Re: coccinelle: improve array.cocci

From: Markus Elfring <markus.elfring@web.de>
Date: Nov 21, 2019, 19:44 UTC
Message-ID: <06ff24b6-f154-9ec6-7b22-05b0ea664a36@web.de>
In-Reply-To: <4f55b06b-35f3-da06-ae86-8a4068f78027@web.de>

>> This case distinction can share a few metavariables with the other
>> transformation approach, can't it?
>
> Can it can, but should it?  In my opinion it should not;

I presented a software design in an other direction. Some data processing approaches can benefit from sharing common information.

> separate concerns should get their own rules.

Strict separation triggers corresponding consequences.

> That's easier to manage for developers.

This view can be reasonable.

> I suspect it's also easier for Coccinelle to evaluate, but didn't check.

I find such an assumption questionable.

> I use MAKEFLAGS += -j6, which runs six spatch instances in
> parallel for the coccicheck make target of Git instead.

The program “spatch” supports parallelisation also directly by the parameter “--jobs”. Did you try it out occasionally?

> OK, so --profile allows to analyze in which of its parts Coccinelle
> spends the extra time.

Some information about time distribution will be displayed.

>> I suggest to use a search for (pointer) expressions instead.
>> This approach can trigger other consequences then.
>
> Why don't we need to check the type?

I got the impression that we stumble on a general challenge for generic source code searches. How many efforts would we like to invest in solving type safety issues?

>> Would you eventually work with SmPL script variants in parallel according
>> to different confidence settings?
>
> Me?  No.

Such a view can be fine.

But I am also still trying to improve various implementation details despite of known software limitations.

> If I can't trust automatic transformations then I don't want them.

I need to live with compromises together also with current development tools.

> I can already generate bugs fast enough manually, thank you very much. :)

This is usual.

I hope that specific tools can make our lives occasionally a bit easier.

Regards, Markus