Re: [PATCH 1/9] build: use if_changed more consistently (and correctly) for prelink*.o

[Roger Pau Monné <roger.pau@xxxxxxxxxx>]

On Mon, Sep 14, 2020 at 12:15:39PM +0200, Jan Beulich wrote:
> Switch to $(call if_changed,ld) where possible; presumably not doing so
> in e321576f4047 ("xen/build: start using if_changed") right away was an
> oversight, as it did for Arm in (just) one case. It failed to add
> prelink.o to $(targets), though, causing - judging from the observed
> behavior on x86 - undue rebuilds of the final binary (because of
> prelink.o getting rebuild for $(cmd_prelink.o) being empty, in turn
> because of .prelink.o.cmd not getting read) during "make install-xen".

I'm not sure I follow why prelink.o needs to be added to targets, does
this offer some kind of protection against rebuilds when doing make
install?

The switch to if_changed LGTM.

Thanks, Roger.