Re: %destructor feedback

[Paul Eggert]

Akim Demaille <address@hidden> writes:

> Do we agree that:
>
> - we desire a warning about typed $n not used in the actions.

Yes, that sounds reasonable.  My assumption is that a missing action
continues to be treated as { $$ = $1; }, so for missing actions Bison
would warn about typed $2, $3, etc., not used but would not warn about
typed $1 not used.

>   A
>   simple macro that ignores its argument suffice to avoid the
>   complaints.

YYUSED should do the trick, no?  So all we need to do is document it?

> - we desire that in all the skeletons no $n is ever freed from an
>   "active" rule, even if we leave it using YYACCEPT, YYERROR, or
>   YYABORT.

Yes, that sounds right.

These two patches are still pending in this area.

http://lists.gnu.org/archive/html/bison-patches/2005-12/msg00048.html
http://lists.gnu.org/archive/html/bison-patches/2005-12/msg00049.html

The former is more important.  I'd like Paul H.'s opinion on it, but
if he's busy I guess we can check it in and then revert it if problems
turn up.  I will try to look at the latter in the next couple of days.

Are there other issues in this area?