Re: [cocci] Working with parameter/expression lists by SmPL

[Jakob Koschel <jkl820.git@gmail.com>]

Hey,

> On 17. Aug 2022, at 21:48, Markus Elfring <Markus.Elfring@web.de> wrote:
> 
>>> I just tried:
>>> 
>>> @main4@
>>> parameter list Ps;
>>> @@
>>> 
>>> int func1(Ps) {
>>> ...
>>> }
>>> 
>>> @main5@
>>> expression list main4.Ps;
>>> identifier func;
>>> @@
>>> 
>>>  func(Es);
>>> + // add comment
>>> 
>>> but that throws:
>>> 
>>> meta: semantic error: incompatible inheritance declaration Ps
>>>  File "test.cocci", line 45, column 24, charpos = 539
>>>  around = ';',
>>>  whole content = expression list main4.Ps;
>> OK, there is a specific context in which this works, but it is only for
>> generating semantic patch rules.
> 
> 
> I would appreciate further explanations for such information.

I've finally managed to get it working. Always when I struggle with coccinelle
and get it working in the end it looks completely obvious. 

Thanks a lot of for all the help Markus & Julia!

Let me show what I was trying to archive and how I solved it:

    @r1@
    parameter list [n] ps;
    type t;
    identifier i,f;
    position p;
    @@

    f(ps, t i, ...) {
    ... when any
    interesting_func@p(..., i, ...)
    ... when any
    }

    @r2@
    identifier r1.f;
    expression list [r1.n] es;
    expression e, e1;
    position p;
    @@

    e = e1
    + // here the argument to interesting_func was assigned
    ... when any
    f(es, e, ...)@p;


I'm running it with this sample code:


    int interesting_func(int argc, char *str) {

    }

    int main(int argc, char *argv[]) {
      int x = 0;

      func1(x, "asdf");
    }

    int func1(int number, char *str) {
      int y = 0;
      char *x = "x";

      interesting_func(number, str);

      interesting_func(number, x);

      interesting_func(y, str);

      interesting_func(y, x);

      return 0;
    }

with the desired result:

diff =
--- test1.c
+++ /tmp/cocci-output-test1.c
@@ -6,7 +6,8 @@ int interesting_func(int argc, char *str
 }

 int main(int argc, char *argv[]) {
-  int x = 0;
+  int x = 0
+    // test;

   func1(x, "asdf");
 }

Thanks,
Jakob

> 
> Regards,
> Markus
> 
>