Hi devs,

while there is the appreciated multiple ABI portage support going on,
a thought on the intentions of the multilib profiles.

Some background:
I do have to support building an older, but still maintained large
application software, that simply does not work when built as 64bit.
As it does not have the need itself for >32bit pointers, and all
the 64bit target platforms do support 32bit binaries too, the plan
to fix the code for 64bits has been cancelled.

I'm using gcc to build the application on all the target unices,
as well as autotools for build management.

As I'm building the toolchain myself too, I configure it with the
32bit host triplet on each platform, usually disabling multilib.

This simply works for ppc-aix, hppa-hpux, ia64-hpux, sparc-solaris,
x86-solaris, even if the underlying OS/kernel is 64bit.
It isn't even necessary to explicitly use --{build,host} at all,
as config.guess tells the 32bit triplet on these platforms.
Additionally, even their default compiler output is 32bit.

But Linux "is not Unix":
Configuring both binutils and gcc needs to be done with:
  $ CC="gcc -m32" /path/to/configure --{build,host}=i686-pc-linux-gnu ...
This works on 64bit RHEL as well as on 64bit SLES (both have 32bit in /lib,
64bit in /lib64, no /lib32), but breaks on amd64+multilib Gentoo Linux.

Problem is that, as x86-linux isn't a multilib target, both ld and gcc
search for 32bit libs&objects in /usr/lib:/lib, as they don't know about
/usr/lib32:/lib32. The error when bootstrapping gcc is:
  /usr/lib/crti.o: file not recognized: File format not recognized

While it is possible to patch binutils[1] and gcc[2] to search in
/usr/lib32:/lib32 even with this otherways non-multilib target,
it doesn't feel like the "right thing" to enable multilib for
just one multilib option.

Isn't the intention of multilib to have a new (64bit) system
be compatible with the corresponding old (32bit) system?

Please comment, thank you!
/haubi/

[1] http://overlays.gentoo.org/proj/alt/changeset/51324
[2] http://overlays.gentoo.org/proj/alt/changeset/51325