Re: [PATCH v5 11/14] autoconf: xen: move standard variables to a generic place

[Ian Campbell <Ian.Campbell@citrix.com>]

On Wed, 2014-05-21 at 09:11 +0100, Jan Beulich wrote:
> >>> On 21.05.14 at 10:03, <mcgrof@suse.com> wrote:
> > On Wed, May 21, 2014 at 12:32 AM, Jan Beulich <JBeulich@suse.com> wrote:
> >>>>> On 20.05.14 at 19:54, <mcgrof@suse.com> wrote:
> >>> On Tue, May 20, 2014 at 07:37:53AM -0600, Jan Beulich wrote:
> >>>> >>> On 20.05.14 at 14:31, <mcgrof@do-not-panic.com> wrote:
> >>>> > --- a/config/StdGNU.mk
> >>>> > +++ b/config/StdGNU.mk
> >>>> > @@ -1,3 +1,17 @@
> >>>> > +# These are standard defaults which you can use to avoid having
> >>>> > +# to run ./configure -- you can use this to compile the hypervisor
> >>>> > +# and the mini os:
> >>>> > +#
> >>>> > +# make xen
> >>>> > +# sudo make -C xen install
> >>>> > +#
> >>>> > +# make -C extras/mini-os
> >>>> > +include $(XEN_ROOT)/config/defaults.mk
> >>>> > +
> >>>> > +# This comes from running configure and will override
> >>>> > +# the defaults.
> >>>> > +-include $(XEN_ROOT)/config/Toplevel.mk
> >>>>
> >>>> So what is the result of running one of the above make invocations
> >>>> without having run ./configure, then running ./configure before
> >>>> running the same make invocation (for an incremental update)
> >>>> again?
> >>>
> >>> In my last v4 you pointed out two targets which you wished to
> >>> ensure would not require running configure, both of those targets:
> >>>
> >>> make xen -j $(getconf _NPROCESSORS_ONLN)
> >>> make -C extras/mini-os -j $(getconf _NPROCESSORS_ONLN)
> >>>
> >>> I have ensured this in this series and the above change indeed
> >>> is what you were looking for.
> >>
> >> I understand that; what I was asking however was what the effect
> >> of the named sequence of operations would be, i.e. whether that
> >> then perhaps would unexpectedly change things between the
> >> original and the incremental make runs. Obviously an incremental
> >> make should change _only_ things where the contributing sources
> >> changed, but nothing resulting merely from the intermediate
> >> ./configure run.
> > 
> > Nothing I've introduced here should hamper the typical compile as what
> > you described you want. Let me know if you find issues though. We're
> > human.
> 
> Did you try it? I would expect the PREFIX change (from /usr to
> /usr/local) alone would already alter things.

Do either the xen or extras/mini-os subtrees depend on PREFIX at all?

At most I would expoect xen to depend on BOOT_DIR which I don't think is
overridable with configure?

I haven't looked at this patch in detail yet but I'm not sure why
Toplevel.mk is getting included in the StdGNU.mk rather than including
it from FOO.mk only for those components which depend on configure
having been run.

Ian.