eglibc and fun with config.sub

[Joseph S. Myers]

On Mon, 19 Sep 2011, David Gilbert wrote:

>    1) Add armv6/v7 to config.sub

Which makes sense anyway (in upstream config.git) as of use to anyone who 
might wish to use such target triplets, in any project using autoconf.

> A bit of digging however led me to find that neither gcc or binutils
> seem to use the version in the triplet
> to determine anything, and the discussion on the linaro-toolchain list
> that started this thread have come to the
> conclusion that people would actually prefer to always ignore the
> triplet (like binutils and gcc) and just
> autodetect from gcc ifdef's.

Logically I prefer autodetection over depending too much on triplets (you 
should still set the various configure variables from the autodetection in 
the way I described).  For some reason the autodetection I set up for 
Power e500 in EGLIBC has however proved rather fragile in practice - lots 
of people have had difficulty getting it working.

As I noted there are several different approaches possible; some are more 
frequent than others and autodetection isn't that frequent in (E)GLIBC at 
present.

-- 
Joseph S. Myers
joseph at codesourcery.com