[Buildroot] [PATCH] infra/pkg-kconfig: Be sure to reconfigure the package on foo-reconfigure

[Yann E. MORIN <yann.morin.1998@free.fr>]

Thomas?, All,

On 2016-09-14 19:42 +0200, Thomas De Schampheleire spake thusly:
> On Wed, Sep 14, 2016 at 11:01 AM, Thomas Petazzoni
> <thomas.petazzoni@free-electrons.com> wrote:
> > On Wed, 14 Sep 2016 09:27:25 +0200, Thomas De Schampheleire wrote:
> >
> >> > This can be problematic when using an override-srcdir suring development
> >> > and the content of the veride-srcdir changes (e.g. on a rebase, a merge,
> >> > or during a bisect).
> >> >
> >> > This is because the configuration (kconfig-wise) of the package is not
> >> > done in the _CONFIGURE_CMDS block, but as a separate action that is not
> >> > part of any step [0].
> >> >
> >> > So, be sure to remove the stamp file .stamp_kconfig_fixup_done during
> >> > the foo-clean-for-reconfigure rule, so that the configuration is applied
> >> > again with the new source tree.
> >> >
> >> > We use another rule, foo-clean-kconfig-for-reconfigure, because we do
> >> > not want to override the default foo-clean-for-reconfigure rule, and we
> >> > have no way to add conditional commands to it.
> >> >
> >> > [0] The reasons it was not done are not entirely clear in my head, but
> >> > IIRC that was not working at the time we tried with Thomas DS.
> >>
> >> This period is very blurry for me :-)
> >>
> >> I can't recall having focused on the reconfigure step for the kconfig
> >> infrastructure, I think I was looking primarily at configure, combined
> >> with cleans and various other combinations. So it is very well
> >> possible that this has always been broken until now.
> >
> > Well, the question is not so much about "reconfigure", but about
> > the configure step itself. Why isn't the configure step done inside
> > <pkg>_CONFIGURE_CMDS ? If it had been done inside the
> > <pkg>_CONFIGURE_CMDS, then those "hacks" to make reconfigure work
> > would not be needed.
> >
> > I'm pretty sure that there's a solid reason for not doing the .config
> > preparation inside <pkg>_CONFIGURE_CMDS, but it'd be great to remember
> > why and document it somewhere :)
> 
> I think the answer to this question is simple: one of the goals was to allow:
> 
> 'make clean linux-menuconfig'
> 
> without this step first building all dependencies of linux (which is
> quite a lot).
> If the kconfig configuration would be part of CONFIGURE_CMDS, then
> we'd end up in that situation.

Yes, that was the basis for our thinking at the time.

Yet, maybe we could just move the call to the $(2)_REGEN_DOT_CONFIG
macro into the CONFIGURE_CMDS (or in a pre-configure hook).

I'll try to test that tonight...

Regards,
Yann E. MORIN.

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