Re: FYI: loop in libtool m4 macros

[Ralf Wildenhues]

Hi Stepan,

* Stepan Kasal wrote on Tue, Jun 21, 2005 at 05:38:57PM CEST:
>
>   sorry for the delay, I was offline until today.

No worries.

> 1)
> m4/ltsugar.m4:
> 
> If you want to be compatible with both old and new m4_cdr, you have to
> use:
>   m4_if([$2], [[]], [],
>         [$2], [], [],
>         [lt_join(...
> 
> I apologize for the inconvinience, but I believe this was a good step
> in the long time perspective.

Well, the interface was not published, so I guess Libtool can't complain
too much.  Your change looks much better than my hack.  Thanks.

> 2)
> In the code of lt_combine cited above, I noticed that you use
>       m4_quote(m4_default([$1], [, ])
> 
> Do you know that this removes all spaces after commas and is effectively
> the same as
>       m4_quote(m4_default([$1], [,])
> ?

Oh, this code was written by Gary, and I have shyed away from it as much
as I could, as m4-literate as I am.  But I think I can see your point.

> I suggest that you use the following instead:
> 
>       m4_ifval([$1], [[$1]], [[, ]])
> 
> This way the first argument to lt_join will be $1, defaulting to ", ".

Hmm.  Neither m4_ifval nor m4_default are published interface by
Autoconf.  So are you telling me above is bound to be less prone
to interface changes than, say,

|       m4_quote(m4_default([$1], [[, ]])

?  Would the latter even be m4-correctly quoted (with correctness being
what the Autoconf manual advises)?

> 3)
> m4/ltoptions.m4
> >  m4_define([_LT_SET_OPTIONS],
> > -[AC_FOREACH([_LT_Option], [$1], [...]
> > +[m4_if([$1], [], [],
> > +       [AC_FOREACH([_LT_Option], [$1], [...]
> 
> This change is a workaround for a bug I introduced.
> Please remove the workaround, as the bug is now fixed in the Autoconf CVS.

When was the bug introduced?  If only with the m4_cdr change, then OK.
If before, I might want to leave this in just to be sure.

Thanks for your explanations.  I will commit what end result we can
agree on.

Regards,
Ralf