[cocci] Fixing a parse error for a SmPL position variable constraint

[cocci] Fixing a parse error for a SmPL position variable constraint

[Markus Elfring]

Hello,

I hope that you would like to take another look at a script variant
(like the following) for the semantic patch language also together with
the software combination “Coccinelle 1.1.1-00676-g99513ec1”.


@find@
position p1, p2;
statement s1, s2;
@@
 if@p1 (...)
 {
    ... when any
    s1
    s2
 }
 ... when any
 if@p2 (...)
 {
    ... when any
    s1
    s2
 }

@duplicated_code@
position find.p1, find.p2;
position pos != find.p2;
statement s1, s2;
@@
*if@p1@pos (...)
*{
    ... when any
*   s1
*   s2
*}
 ... when any
*if@p2 (...)
*{
    ... when any
*   s1
*   s2
*}


Temporary test result:
Markus_Elfring@Sonne:…/Projekte/Coccinelle/janitor> spatch --parse-cocci show_same_statements7z.cocci
…
meta: parse error:
  File "show_same_statements7z.cocci", line 21, column 21, charpos = 226
  around = 'p2',
  whole content = position pos != find.p2;


Will more desirable analyses become possible by similar source code search approaches?

Regards,
Markus

Re: [cocci] Fixing a parse error for a SmPL position variable constraint

[Julia Lawall]

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On Tue, 13 Feb 2024, Markus Elfring wrote:

> Hello,
>
> I hope that you would like to take another look at a script variant
> (like the following) for the semantic patch language also together with
> the software combination “Coccinelle 1.1.1-00676-g99513ec1”.
>
>
> @find@
> position p1, p2;
> statement s1, s2;
> @@
>  if@p1 (...)
>  {
>     ... when any
>     s1
>     s2
>  }
>  ... when any
>  if@p2 (...)
>  {
>     ... when any
>     s1
>     s2
>  }
>
> @duplicated_code@
> position find.p1, find.p2;
> position pos != find.p2;

Try switching the above two lines.

julia

> statement s1, s2;
> @@
> *if@p1@pos (...)
> *{
>     ... when any
> *   s1
> *   s2
> *}
>  ... when any
> *if@p2 (...)
> *{
>     ... when any
> *   s1
> *   s2
> *}
>
>
> Temporary test result:
> Markus_Elfring@Sonne:…/Projekte/Coccinelle/janitor> spatch --parse-cocci show_same_statements7z.cocci
> …
> meta: parse error:
>   File "show_same_statements7z.cocci", line 21, column 21, charpos = 226
>   around = 'p2',
>   whole content = position pos != find.p2;
>
>
> Will more desirable analyses become possible by similar source code search approaches?
>
> Regards,
> Markus
>

Re: [cocci] Fixing a parse error for a SmPL position variable constraint

[Markus Elfring]

>> position find.p1, find.p2;
>> position pos != find.p2;
>
> Try switching the above two lines.

Did you try this SmPL code adjustment out already in your test environment?


Markus_Elfring@Sonne:…/Projekte/Coccinelle/janitor> spatch --parse-cocci show_same_statements7w-20240214.cocci
…
Variable find.p2 in duplicated_code cannot be used as both a position and a constraint


How does this error message (from the software combination “Coccinelle 1.1.1-00687-g0df3efff”)
fit to the discussed data processing intention?

Regards,
Markus

Re: [cocci] Fixing a parse error for a SmPL position variable constraint

[Julia Lawall]

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On Wed, 14 Feb 2024, Markus Elfring wrote:

> >> position find.p1, find.p2;
> >> position pos != find.p2;
> >
> > Try switching the above two lines.
>
> Did you try this SmPL code adjustment out already in your test environment?
>
>
> Markus_Elfring@Sonne:…/Projekte/Coccinelle/janitor> spatch --parse-cocci show_same_statements7w-20240214.cocci
> …
> Variable find.p2 in duplicated_code cannot be used as both a position and a constraint

OK, I guess it is not allowed.  Actually, the semantics of positive an
negative uses of a position variable is quite different, so it seems that
it is not allowed to use both at once.

But it should be possible to use two position variables at the original
place.

julia

>
>
> How does this error message (from the software combination “Coccinelle 1.1.1-00687-g0df3efff”)
> fit to the discussed data processing intention?
>
> Regards,
> Markus
>

Re: [cocci] Fixing a parse error for a SmPL position variable constraint

[Markus Elfring]

>> Markus_Elfring@Sonne:…/Projekte/Coccinelle/janitor> spatch --parse-cocci show_same_statements7w-20240214.cocci
>> …
>> Variable find.p2 in duplicated_code cannot be used as both a position and a constraint
>
> OK, I guess it is not allowed.  Actually, the semantics of positive an
> negative uses of a position variable is quite different, so it seems that
> it is not allowed to use both at once.

Do we stumble on a target conflict here?


> But it should be possible to use two position variables at the original place.

Would you like to adjust affected software components accordingly?

Regards,
Markus