Partial autoconf transition thoughts

[Alexandre Oliva]

On Jun 10, 2003, "Maciej W. Rozycki" <macro@ds2.pg.gda.pl> wrote:

>  Well, if I specify --host, I mean I want to use a different alias than
> the one that is expanded by config.sub.

--host has absolutely nothing to do with config.sub.  --host defaults
to --build, that defaults to the output of config.guess.  If you want
to override --build, just do it, and it will be propagated to host as
well.  If you mean to specify different --build and --hosts, that's a
cross.  If you specify --build and --host and they're identical,
that's a native for now, but it'll eventually be a cross because
there's no point in specifying --host if you don't want a cross.

> The change is not purely internal
> to the compilation process -- there are examples, binutils and gcc
> inclusive, where this alias gets propagated to file names, e.g. as a
> prefix to executables or as a name of the tooldir.

That's --target, something entirely different.

>  I'd like to see this capability preserved, not necessarily exactly the
> way it's being done now.  One possibility for host_alias and also
> target_alias is to default to build_alias and host_alias instead of host
> and target, respectively, as it happens now. 

Huh?  Where is it that host_alias defaults to build or build_alias?
In autoconf, it defaults to neither.  If --host is not specified,
host_alias remains blank, not the same as build_alias, not the same as
nonopt, not the same as the output of config.guess.  Nathan was kind
enough to write macros that do exactly what you want, AFAICT, setting
{build,host,target}_noncanonical, which is what we'd now use for what
we used to use {build,host,target}_alias, whose meaning is slightly
different in autoconf 2.5x.  I.e., it does what you already.

-- 
Alexandre Oliva   Enjoy Guarana', see http://www.ic.unicamp.br/~oliva/
Red Hat GCC Developer                 aoliva@{redhat.com, gcc.gnu.org}
CS PhD student at IC-Unicamp        oliva@{lsd.ic.unicamp.br, gnu.org}
Free Software Evangelist                Professional serial bug killer