[Buildroot] [PATCHv3 04/20] toolchain: introduce a virtual package

[Thomas Petazzoni <thomas.petazzoni@free-electrons.com>]

Dear Fabio Porcedda,

On Wed, 9 Oct 2013 10:26:56 +0200, Fabio Porcedda wrote:
> Hi Thomas,
> 
> On Tue, Oct 8, 2013 at 8:17 PM, Thomas Petazzoni
> <thomas.petazzoni@free-electrons.com> wrote:
> > [...]
> >  prepare: $(BUILD_DIR)/buildroot-config/auto.conf
> >
> > -toolchain: prepare dirs dependencies $(BASE_TARGETS)
> > -
> > -world: toolchain $(TARGETS_ALL)
> > +world: $(BASE_TARGETS) $(TARGETS_ALL)
> 
> Why do you change that? It seems to me better to use the "toolchain"
> target as dependency instead of $(BASE_TARGETS)
> IMHO  $(BASE_TARGETS) is an implementation detail of the new toolchain
> virtual package so it's better to use inside the new toolchain virtual
> package.

BASE_TARGETS = toolchain, so there are exactly equivalent. I'm not sure
why you say BASE_TARGETS is an implementation detail of the new
toolchain virtual package. BASE_TARGETS now never has any other value
than just "toolchain".

Of course, we might want to get rid of BASE_TARGETS later on, but for
the moment, BASE_TARGETS is still used in other places, like when
building the list of packages for which make source or make
external-deps should be executed:

PACKAGES_SOURCE:=$(patsubst %,%-all-source,$(PACKAGES) $(BASE_TARGETS))
PACKAGES_EXTERNAL_DEPS:=$(patsubst %,%-all-external-deps,$(PACKAGES) $(BASE_TARGETS))

Ultimately, toolchain will no longer need to be part of BASE_TARGETS as
it will be handled just as a normal package dependency (done by your
patches). But I'm trying to do things step by step, progressively.
Therefore, in the end, I believe the world rule will no even contain
"toolchain" and $(TARGETS_ALL) but just $(PACKAGES), but we can't
change the world in one day :-)

Best regards,

Thomas
-- 
Thomas Petazzoni, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com