Re: Multilib configure failing

[Phil Edwards <phil at codesourcery dot com>]

On Thu, Dec 18, 2003 at 10:04:12PM +0100, Ulrich Weigand wrote:
> For autoconf-2.57 generated configure scripts, however, the
> variable ${ac_configure_args} already contains the settings
> for CC etc. in use with the *master* (non-multilib) build.
> The presence of those arguments now causes configure to
> completely ignore the environment variables CC etc. set up
> by config-ml.in; in effect, the multilib configure runs
> using exactly the same CC settings as the master configure.

Yes.  I discovered this here

    http://gcc.gnu.org/ml/gcc/2003-07/msg01859.html

and did an evil hack for libstdc++ here

    http://gcc.gnu.org/ml/gcc/2003-07/msg01903.html

and extended it here

    http://gcc.gnu.org/ml/libstdc++/2003-08/msg00133.html


> (Even more subtly, libf2c has a 2.13 configure script, so
> it should work.  It doesn't, however, because all the 
> various libraries for the same multilib flags share a
> single config.cache.  This is initialized by the first
> library to be configured, which happens to be the 2.57
> autoconf'ed libiberty.  This writes an incorrent CC
> setting to config.cache which gets then reused by all
> subsequent target libraries.)

The real solution is moving multilibs to the top level.

I have successfully experimented with disabling the shared cache (by forcing
a local cache) for similar reasons:

    http://gcc.gnu.org/ml/libstdc++/2003-08/msg00221.html

Not really a solution for you, but it does let you see what settings get saved
where.

-- 
Debugging is twice as hard as writing the code in the first place.
Therefore, if you write the code as cleverly as possible, you are,
by definition, not smart enough to debug it.
    - Brian W. Kernighan