Re: How to disable CLANG & co build in buildworld?

In message: <4C1315F9.6000300_at_FreeBSD.org>
            Doug Barton <dougb_at_freebsd.org> writes:
: On 06/11/10 14:18, M. Warner Losh wrote:
: > "This" is building the proper set of tools for the target.  It is easy
: > to do, and only a couple lines of Makefile foo in Makefile.inc1
: > instead of in bsd.own.mk.  It is a fairly natural consequence of the
: > tbemd stuff I have been working on and have started merging.
: >
: > The consequences today are that you build some extra tools that are
: > only needed to build clang when in fact you aren't really going to be
: > building clang.  The "cost" is however long it takes to do this on the
: > platform you are building on.  This can range from a minute or two to
: > tens of minutes depending on the power of your build system.
: 
: Ok, obviously I'm dense because I didn't understand an answer to my
: question anywhere in there. :) So let me try again. Why are we not
: optimizing for the common case, where the world is built on the system
: it's going to run on, which means that WITHOUT_CLANG can easily mean
: exactly that?

Because if we optimize for that case, we break the other cases.
Broken trumps fast, so we always build the clang tools.

The reason it is broke is that the default for clang varies between
architectures, which makes the usual tests for MK_CLANG not work for
the bootstrap tools phase.

Warner