Re: Problem with LIBS generated by a macro

[Ralf Wildenhues]

Hello Sergio,

* Sergio Belkin wrote on Sat, Oct 30, 2010 at 11:55:17PM CEST:
> I've autoconfiscated a project that link against libresolv and
> libtpthread, and optionally against ssl, mysqlclient and pq. I am
> working on Fedora 13 (i686).
> 
> I've found a macro AX_EXT_HAVE_LIB
> (http://www.gnu.org/software/autoconf-archive/ax_ext_have_lib.html)
> that "is identical to AC_SEARCH_LIBS with the exception that will add
> -L<directory> when looking, and use a different variable for each
> directory. " It seems great for me!
> 
> The problem is that at the end only take the last library found, in my
> case "pq".
> 
> It seems that macro override the earlier value of "LIBS" variable.

This looks like a bug in the AX_EXT_HAVE_LIB macro to me, as it is
documented to only add to LIBS but not remove existing entries.

>  I've examined the configure script but it's a bit tricky, you may
> read a snippet about the macro on http://pastebin.com/vHKYp0UR
> 
> I've tried modifying macro, replacing the final LIBS="$new_libs" por
> LIBS="$new_libs $LIBS" which you may read  on
> http://pastebin.com/DNCCfgnU
> 
> But now LIBS ends as: '-lpq -lmysqlclient -lssl -lpthread -lresolv
> -lssl -lpthread -lresolv '
> 
> It seems harmless but it's too ugly, isn't it?

Not necessarily.

I suggest you report this to the autoconf-archive-maintainers list,
or their bug tracker, so that the macro can be fixed.

Cheers,
Ralf