Re: [cocci] match arbitrary argument position

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

>>> looking at the following code snippet:
>>>
>>> test.c:
>> …
>>>      func3(argc, argv);
>>>
>>>      func3(argv);
>>
>> Would you like to handle function overloading here?
> I'm not exactly sure I understand what you mean here.


I suggest to take another look at the implementation detail that it was specified
to call a function with different number of expressions.


> Finally I would like to archive something like this:


You would probably like to achieve special source code transformations
instead of archiving items.



> In the end I want to, for example, turn it into:
>
> void func(void) {
>
>     int x = 0;
>     // 'x' was used as first argument to interesting_func
>     int y = 0;
>     // 'y' was used as first argument to interesting_func
>
>     func1(x, 0);
>     func2(0, y);
> }
>
> void func1(int arg1, int arg2) {
>     interesting_func(arg1);
> }
>
> void func2(int arg1, int arg2) {
>     interesting_func(arg2);
> }


Will any filters (or related SmPL constraints) be relevant for such function names?


> Basically I want to flag create the matching from 'x'/'y' to the argument to interesting_func.


How do you think about further possibilities to choose which function argument
should be passed as an expression for corresponding computations?


> I was imagining if I could match the parameter list of any function calling 'interesting_func'
> then I can also create a matching from x to that function call and do the rest of the correlation
> in python somehow.


I propose to reconsider also the need for extra scripting according to
the discussed use case.



> However I'm still failing to detect if any argument (arg1 or arg2 in this case) is used as
> any argument in 'interesting_func'.


Multiple SmPL rules can be applied on demand for desirable data processing results.


> I hope this makes more sense?


It can be challenging to express special imaginations by the means of
the semantic patch language.



> hopefully the example above makes it a bit more clear.


It seems so.

Regards,
Markus