make buildworld: build changes only?

[Conrad J. Sabatier]

On 03-Jul-2004 Geert Hendrickx wrote:
>> make -DNOCLEAN buildworld
>> 
>> See /usr/src/Makefile.inc1 for all the various switches that are
>> available.  You may want to set some of them permanently in
>> /etc/make.conf.
>> 
>> Just do be aware that doing this can lead to trouble sometimes.
> 
> Ok, I think this is what I was looking for.  But what's the
> difference
> between these: ?  
> 
>#       -DNOCLEANDIR run ${MAKE} clean, instead of ${MAKE} cleandir
>#       -DNOCLEAN do not clean at all

Well, as the comment says, -DNOCLEAN does no cleaning at all before
starting the build.

The comments in /usr/share/mk/bsd.obj.mk (which is indirectly called
from Makefile.inc1):

#   clean:
#       remove ${CLEANFILES}; remove ${CLEANDIRS} and all contents.
#
#   cleandir:
#       remove the build directory (and all its contents) created by obj
#
#   obj:
#       create build directory.
#

So "make clean" first cleans any object files out of the object
directories and then removes them (why, I don't know).

"make cleandir" simply blasts away the entire object directory.

-- 
Conrad J. Sabatier <conrads at cox.net> -- "In Unix veritas"