Re: Two-month patch ping: Re: powerpc*le-linux support

[Alan Modra]

On Thu, Aug 22, 2013 at 09:34:10PM +0700, Gary V. Vaughan wrote:
> > How can it be correct to say "-m elf32lppclinux" (32-bit) when $host is
> > explicitly 64-bit? That seems like utter garbage to me. What am I
> > missing this time?

As far as I understand, this piece of libtool is supplying ld options
when your host compiler defaults to something other than what $host
implies.  Which sounds very strange, but consider that on a
powerpc64-linux host your gcc will usually compile to both 32-bit and
64-bit objects.  Both 32-bit and 64-bit objects will run on the host,
and whether gcc produces 32-bit by default (most common a few years
ago) or 64-bit (most common now), depends on how gcc was configured.

So if $host is powerpc64-linux and $CC is gcc and gcc produces 64-bit
by default, and $LD is powerpc64-linux-ld then no ld options are
needed.  When generating 32-bit libraries on this system, $host is
powerpc-linux, $CC is still gcc, and $LD may be powerpc-linux-ld.
That's a problem because $CC with no options produces 64-bit objects
but $LD with no options is expecting 32-bit.

This is all somewhat of a guess on my part, but I've seen these $LD
and $CC selections.  Most configure scripts seem to prefer
"powerpc64-linux-ld" over plain "ld" when $host is powerpc64-linux,
and similarly "powerpc-linux-ld" for $host of powerpc-linux.

> I don't get it either, and I can't test it.  I trust the ppcle community
> will commence shouting if the patches have done something horrible.

It's broken.  Please apply exactly the tested patch I submitted, or if
powerpc-* and similar in the switch statement is somehow the wrong
style (we've tested for powerpc*-*linux* already!), then make them
powerpc-*linux*.  Not powerpc*-*linux*, which is exactly the same
mistake I made with my first patch..

-- 
Alan Modra
Australia Development Lab, IBM