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

On Fri, Aug 23, 2013 at 10:39:42AM +0200, Peter Rosin wrote:
> On 2013-08-22 17:48, Alan Modra wrote:
> > 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.
> 
> Sheesh. You are lying about $host, and get to keep all the pieces when

You're jumping to a completely wrong conclusion.  No "lying", avoiding
cross-compilation or any such thing.  Just a bi-arch compiler.  The
same $CC for native powerpc64-linux and a powerpc64-linux to
powerpc-linux cross.

Why don't *you* do some digging to see what this code is about?
Obviously my explanation, which as I said is somewhat of a guess,
missed the mark.

-- 
Alan Modra
Australia Development Lab, IBM