Re: AC_CHECK_LIB(m, main, LIBM="-lm") broken with C++ [PATCH]

On Wed, 5 Feb 2003, Robert Boehne wrote:

> How about this patch?

The patch looks great to me.

Bob

> The math library is not actually used by anything but the
> test suite in Libtool, so as long as the C standard and
> common practice put "cos" in -lm it's all good.
>
> ChangeLog entry:
>
> 2003-02-05  Robert Boehne  <rboehne@xxxxxxx>
>
>       * libtool.m4 (AC_CHECK_LIBM): Search for a real symbol in
>       the math library rather than 'main', it causes problems for
>       C++ compilers with certain Auto* tools.
>       (AC_LIBLTDL_INSTALLABLE): ditto.
>
> Index: libtool.m4
> ===================================================================
> RCS file: /cvsroot/libtool/libtool/libtool.m4,v
> retrieving revision 1.297
> diff -u -r1.297 libtool.m4
> --- libtool.m4        5 Feb 2003 07:03:55 -0000       1.297
> +++ libtool.m4        6 Feb 2003 02:50:39 -0000
> @@ -2246,10 +2246,10 @@
>    ;;
>  *-ncr-sysv4.3*)
>    AC_CHECK_LIB(mw, _mwvalidcheckl, LIBM="-lmw")
> -  AC_CHECK_LIB(m, main, LIBM="$LIBM -lm")
> +  AC_CHECK_LIB(m, cos, LIBM="$LIBM -lm")
>    ;;
>  *)
> -  AC_CHECK_LIB(m, main, LIBM="-lm")
> +  AC_CHECK_LIB(m, cos, LIBM="-lm")
>    ;;
>  esac
>  ])# AC_CHECK_LIBM
> @@ -2294,7 +2294,7 @@
>  # In the future, this macro may have to be called after
> AC_PROG_LIBTOOL.
>  AC_DEFUN([AC_LIBLTDL_INSTALLABLE],
>  [AC_BEFORE([$0],[AC_LIBTOOL_SETUP])dnl
> -  AC_CHECK_LIB(ltdl, main,
> +  AC_CHECK_LIB(ltdl, lt_dlinit,
>    [test x"$enable_ltdl_install" != xyes && enable_ltdl_install=no],
>    [if test x"$enable_ltdl_install" = xno; then
>       AC_MSG_WARN([libltdl not installed, but installation disabled])
>
>
> Albert Chin wrote:
> >
> > On Wed, Feb 05, 2003 at 03:00:39PM -0600, Bob Friesenhahn wrote:
> > > I posted a detailed message to bugs-libtool@xxxxxxx and
> > > bugs-autoconf@xxxxxxx but there has been no response at all so I will
> > > post again.
> > >
> > > CVS libtool.m4 contains lines like
> > >
> > >   AC_CHECK_LIB(m, main, LIBM="-lm")
> > >
> > >     and
> > >
> > >   AC_CHECK_LIB(ltdl, main, ... blah
> >
> > Gross!
> >
> > > What is the best path forward?
> >
> > Replace main with a *real* function in one of the libraries.
> >
> > --
> > albert chin (china@xxxxxxxxxxxxxxxxxx)
> >
> > _______________________________________________
> > Libtool mailing list
> > Libtool@xxxxxxx
> > http://mail.gnu.org/mailman/listinfo/libtool
>
>
> _______________________________________________
> Libtool-patches mailing list
> Libtool-patches@xxxxxxx
> http://mail.gnu.org/mailman/listinfo/libtool-patches
>

======================================
Bob Friesenhahn
bfriesen@xxxxxxxxxxxxxxxxxxx
http://www.simplesystems.org/users/bfriesen