Re: [gentoo-dev] emake question

[Aron Griffis]

Hi Daniel,

Daniel Robbins wrote:	[Fri Aug 17 2001, 03:40:22PM EDT]
> On Fri, Aug 17, 2001 at 03:09:25PM -0400, Aron Griffis wrote:
> > Hello,
> >
> > I'm looking at emake, trying to understand what is being accomplished.
> > It seems useless to me, though I'll be quite happy if told that I'm
> > wrong.
> >
> > (1) It claims to "auto-parallel make without the annoying syntax".  But
> >     it does nothing to parallelize the make process that I can see.
> >
> > (2) It uses env, which does nothing in this case.
> >
> > (3) It uses a variable MAKEOPTS to pass options along to sub-makes.
> >     Isn't that redundant to GNU make's built in MAKEFLAGS (which are set
> >     and passed to sub-makes automatically)?
>
> By default, MAKEOPTS is defined at "-j 2", so emake does auto parallelize
> makes.  The reason for emake is that some packages build in parallel, and
> some don't.  Those that do build in parallel should use emake in order to
> build faster, and those that don't should have a little "doesn't work with
> emake" comment and just use plan make instead.

Sorry if I'm being obstinate, but it still doesn't seem useful to me.
The passing of MAKEOPTS to the sub-makes doesn't do anything, since GNU
make passes its flags to the sub-makes via MAKEFLAGS.  This includes
parallelization via -j.

That reduces emake to essentially running "make -j2" instead of "make".
Seems like that part could be left up to the ebuild authors.

Exhibit A:

    # A completely useless Makefile
    all:
	    # Start a sub-make that does a lot of nothing
	    $(MAKE) asdf{0,1,2,3,4,5}{0,1,2,3,4,5,6,7,8,9}
    asdf%:
	    @echo $@ -$(MAKEFLAGS)

Run exhibit A with "make -j" or "make -j10" or whatever a few times and
note that the sub-make is running in parallel...  :-)

Thanks,
Aron (who likes abstractions but fights them when they just muddy the water)