On Sun, 2 Aug 2020, Markus Elfring wrote:

> >> Will the Coccinelle software itself present a warning like “metavariable __attr__
> >> not used in the - or context code”?
> >
> > No.  It's not a metavariable.
>
> How do you call the following items in the update step “[PATCH 42/43] tests:
> Add test case to match meta attribute”?
> https://lore.kernel.org/cocci/25fb4894-65d3-dc57-dbfd-93d3482d8fee@web.de/
> https://systeme.lip6.fr/pipermail/cocci/2020-July/008036.html
>
> attribute name __attr__;
> attribute a;

attribute a; declares a metavariable that matches attributes.

attribute name __attr__; declares that __attr__ is the name of an
attribute.

These "name" declarations can be used in the parsing of the C code as a
hint that __attr__ should be parsed in a special way.

julia