On Thu, May 27, 2010 at 09:36:42AM +0200, Alan Barrett wrote:
> On Thu, 27 May 2010, David A. Holland wrote:
> > -cleandir distclean: cleanlibdir
> > +cleandir distclean: .WAIT cleanlibdir
>
> I would have expected .WAIT to be a no-op in this context. How does
> "do nothing, wait until you have finished doing nothing, then make
> cleanlibdir" differ from "make cleanlibdir" ?
Because that's not the only RHS for cleandir. If you have
foo: bar
foo: .WAIT baz
it's the same as
foo: bar .WAIT
foo: baz
or
foo: bar .WAIT baz
It is fragile because it depends on the ordering of declarations and
includes, but it does work.
For example, try this makefile with -j8, with and without the .WAIT:
all: a b c
all: .WAIT d e f g h
a b c d e f g h:
@echo '>> $@'
@sleep 1
@echo ' $@ >>'
--
David A. Holland
dholl...@netbsd.org
