Re: [cocci] List global variables with SmPL

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

> Here is a suggested solution for all of the problems reported so far:
>
> @r@
> type T;
> identifier i;
> expression E;
> position p : script:python(i) { p[0].current_element == i };
> attribute name __randomize_layout;
> @@
>
> (
> T i(...);
> |
> T i(...,......);
> |
> extern T i;
> |
> T i@p;
> |
> T i@p=E;
> )


I find that this SmPL code needs further clarifications.


The information “… current_element is the name of the function containing the matched position; …”
is provided by the manual for the Coccilib module.

* How can a function name be referenced if data should be determined for
  the global scope?

* Why is a comparison attempted in the scripted constraint at all
  if the passed identifier would refer to a variable name according to the metavariable “i”?


> @script:python@
> i << r.i;
> p << r.p;
> @@
> print (i)
…
> The problem with __randomize_layout is that the Coccinelle parser is not
> recognizing it as an attribute.  You can force that by putting a
> declaration in the semantic patch.
>
> It seems that ... in a function parameter list does not match the ... in C
> for a variable list of arguments.  That ... can be matched explicitly by
> ...... so I have added another case with that.
>
> I als combined all of the patterns into one rule.  By inheriting the
> position varaible p into the python rule at the end, that python rule is
> only executed if p is defined, which makes it select the cases of interest
> and ignore the others.


Will these details trigger any improvements for the software documentation?

Regards,
Markus