Re: [PATCH 0/6] api.value.type support

[Stefano Lattarini]

Hi Akim.

On 02/25/2013 11:51 AM, Akim Demaille wrote:
> Hi Joel!
> 
> Thanks a lot for your answer!  
> 
> (Hi Stefano, again, some rants against -y :)
> 
> [MEGA-SNIP]
>
> Automake's use of -y is really troublesome.
>
Actually, that comes from the autoconf-provided AC_PROG_YACC (which,
as documented in the Autoconf manual, sets output variable YACC to
'bison -y' if bison is found ...

> Actually, it is
> rather Autoconf which is a PITA here, that's it that decides
> to define 'YACC=bison -y'.
>
... but I see you already knew that :-) I think this should brought up to
the autoconf list, to decide if, when and how the '-y' could be dropped;
Automake-based package will then automatically benefit from the Autoconf
improvement (if it is eventually deemed to be an improvement, and not
just a possible source for backward-incompatibilities).

The real question for Automake is: how would such a change interact with
the 'ylwrap' script, which expects 'y.tab.h' and 'y.tab.c' as the names of
the output files?  Hmm....

> Also, currently we have a (hidden) option which is a
> synonym of --yacc:
> 
>   { "fixed-output-files", no_argument,  0,   'y' },
>   { "yacc",               no_argument,  0,   'y' },
> 
> It should rather just change the output file names to be y.tab.c
> and so forth, but not set -Wyacc.  And Autoconf should use it.
>
I like this proposal, mostly because it wouldn't require any change
in Automake ;-)

As an aside, how long has that hidden option been present in Bison?
If the answer is not "practically since forever", the new Autoconf
could will also have to check that the available bison program
actually supports it ...

> Meanwhile there is one way out: have people pass -Wno-yacc to their
> flags.
> 
> [SNIP]

Regards,
  Stefano