Re: Compiler checks in AM_PROG_LIBTOOL

[Ralf Wildenhues]

Hello Fredrik,

* Fredrik Tolf wrote on Thu, Mar 08, 2007 at 03:52:27PM CET:
> On Mon, 2007-03-05 at 10:04 +0100, Ralf Wildenhues wrote:
> > As a workaround (that AFAICS
> > won't break things in the future) you can put
> >   m4_defun([_LT_AC_LANG_CXX_CONFIG])
> >   m4_defun([_LT_AC_LANG_F77_CONFIG])
> > 
> > in you configure.ac before AC_PROG_LIBTOOL (for which AM_PROG_LIBTOOL is
> > an older name).
> 
> I don't know much about how libtool works, but if the compiler checks
> are so unnecessary that I can just forcibly remove them like that, why
> were they put in libtool to begin with? Is it some kind of historical
> leftover? Not that it matters practically -- I'm just curious.

Well, the idea is that the checks for C++ should be used only if you use
C++.  CVS Libtool finds out by itself whether you use AC_PROG_CXX and
only then enables the tests for C++.  Similar with Fortran 77 and
AC_PROG_F77.  Libtool 1.5.x isn't smart enough to see that you're not
using C++ or Fortran 77.  It's simply a bug in 1.5.x.

Those compiler checks are only unnecessary if you do not use those
languages in your package.  If you use C++ or Fortran 77 then you can
not use the above.

Cheers,
Ralf