Should "make -DNOCLEAN buildworld" always rebuild clang?

[Dimitry Andric]

On May 30, 2013, at 23:19, Dimitry Andric <dim at freebsd.org> wrote:
> On May 30, 2013, at 22:49, David Wolfskill <david at catwhisker.org> wrote:
>> As some of you may be aware, I track stable/9 daily.  (A recent history
>> of "uname -vp" outputs for stable/9 on my laptop may be seen at
>> <http://www.catwhisker.org/~david/FreeBSD/history/laptop_i386_9.txt>.)
>> 
>> And lest this message is misinterpreted: I am not complaining.  In
>> particular, I am not complaining about clang: I switched to using clang
>> for the system-build compiler shortly after BSDCan 2012, and I've never
>> looked back.  I'm very happy to have an alternative to gcc.
>> 
>> Yesterday, I had built r251096M; this morning, I updated to r251113M
>> and rebuilt with "touch /sys/conf/newvers.sh && make -j4 -DNOCLEAN
>> buildworld".  (Copy of typescript file available at
>> <http://www.catwhisker.org/~david/FreeBSD/stable_9/bw.txt>.)
>> 
>> As shown in the typescript, the sole change showed up as:
>> 
>> Script started on Thu May 30 04:22:12 2013
>> svn update /usr/src
>> Updating '/usr/src':
>> U    /usr/src/usr.sbin/newsyslog/newsyslog.c
>> Updated to revision 251129.
>> 
>> Script done on Thu May 30 04:22:18 2013
>> 
>> 
>> which would seem to have had minimal effect on the toolchain.
>> 
>> Yet the vast bulk of the above-cited typescript appears to be showing
>> the toolchain being rebuilt.  Is this intended?
> 
> It is not really intended, but an unfortunate side effect of
> <http://svnweb.freebsd.org/changeset/base/250217>.  When you touch
> sys/conf/newvers.sh, it causes include/Makefile to generate a new
> osreldate.h, so everything depending on that header will be rebuilt.

Gah, never mind that...  I failed to notice you are building stable/9,
sorry.  In that case, I don't know exactly what is going on.  Obviously,
osreldate.h is being updated too, but I would not expect so much stuff
to be rebuilt because of it.

-Dimitry