[Buildroot] [PATCH 07/11] support/scripts/pkg-stats: store dependencies of package

[Thomas Petazzoni <thomas.petazzoni@bootlin.com>]

On Fri, 3 Jan 2020 17:39:13 +0100
Heiko Thiery <heiko.thiery@gmail.com> wrote:

> Thought it is a good idea because I saw that on the
> https://layers.openembedded.org/layerindex/recipe/45257/. They also
> show the dependencies with a note that this can differ dependent on
> the real used configuration. But if you think it is too confusing I
> can drop that.

Don't get me wrong, it would be nice to have the dependencies of
packages, but it is simply not possible.

Consider a package like this:

FOO_DEPENDENCIES = bar baz

ifeq ($(BR2_PACKAGE_LIBPNG),y)
FOO_DEPENDENCIES += libpng
endif

If you run "make VARS=FOO_DEPENDENCIES printvars" with no Buildroot
configuration defined, or with a Buildroot configuration defined that
has the libpng package disabled, it will return:

FOO_DEPENDENCIES=bar baz

If however, you run the same command with a Buildroot configuration
defined that has the libpng package enabled, it will return:

FOO_DEPENDENCIES=bar baz libpng

So as you can see, there is nothing like "the list of all dependencies
of a package" that you can get with printvars. Lots of dependencies are
optional. Some are even conflicting, like a package can depend on A
*or* B, but not both. Etc.

This is why I think it is not a good idea to show those dependencies,
because they simply cannot be correct "in general": they can only be
correct within the context of a particular Buildroot configuration.

Best regards,

Thomas
-- 
Thomas Petazzoni, CTO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com