Re: [xml] Using libiconv

[xml thewrittenword com]

On Tue, Jul 03, 2001 at 12:06:16PM +0100, Brian Stafford wrote:
> On Mon,  2 July 20:06 xml thewrittenword com wrote:
>
> > I also think the patches address different problems.
> >
> > I believe http://mail.gnome.org/archives/xml/2001-July/msg00002.html
> > is wrong for the following reasons (I have not tried it):
> >   1. Using AC_CHECK_LIB before AC_TRY_FUNC is just wrong. The
> >      fact that the library exists doesn't mean it should be used.
>
> A very sweeping statement.  You are not allowing for the fact that
> libiconv is something of a special case.

I have yet to run across a configure.in where AC_CHECK_LIB before
AC_CHECK_FUNC was correct. AC_CHECK_LIB before AC_CHECK_FUNC makes
assumptions about the system and autoconf is not about making
assumptions.

> >   2. If you have both libiconv in /usr/lib and /usr/local/lib
> >      and you wish the one in /usr/local/lib to win, set
> >      LDFLAGS="-L/usr/local/lib" before running configure.
>
> I know this but this has nothing to do with the point.  You have
> misunderstood the problem.  libiconv *replaces* the iconv.h from glibc.
> The replacement iconv.h redefines the iconv_xxx functions to libiconv_xxx.  
> Since AC_TRY_FUNC finds iconv in glibc but the compiler includes
> the replacement iconv.h linking is guaranteed to fail.  But as you say,
> you haven't tried it so you wouldn't know.

So then wouldn't:
  CPPFLAGS="-I/usr/local/include" LDFLAGS="-L/usr/local/lib" \
  ./configure ...

solve your problem?

> Personally I'd prefer a pragmatic approach to a philosophical one
> on this one.

Then how about we add --with-iconv=DIR which allows you to specify the
parent include/lib directory for iconv? All this would really do is
add DIR/include to $CPPFLAGS and DIR/lib to $LDFLAGS.

BTW, this would mimic how --with-zlib works. Solaris 8/SPARC has libz
in /usr/lib and zlib.h and zconf.h in /usr/include. We have our own
zlib in /opt somewhere. We use --with-zlib=/opt/zlib to use *our* zlib
which completely *replaces* the system zlib. Same situation as your
libiconv problem. Note though that we could just have well have solved
our problem by setting CPPFLAGS/LDFLAGS but I added the
--with-zlib[=DIR] option to help us out. Something similar should be
done for you.

-- 
albert chin (china thewrittenword com)