Re: [XEN PATCH v4 15/18] xen/build: use if_changed to build guest_%.o

[Anthony PERARD <anthony.perard@xxxxxxxxxx>]

On Wed, Apr 08, 2020 at 03:02:21PM +0200, Jan Beulich wrote:
> On 31.03.2020 12:30, Anthony PERARD wrote:
> > Use if_changed for building all guest_%.o objects, and make use of
> > command that already exist.
> > 
> > This patch make a change to the way guest_%.o files are built, and now
> > run the same commands that enforce unique symbols. But with patch
> > "xen,symbols: rework file symbols selection", ./symbols should still
> > select the file symbols directive intended to be used for guest_%.o
> > objects.
> 
> I'm having trouble making the connection between the change to the
> symbols tool and the adjustments made here:

The change to symbol tool is to allow this change.

> > --- a/xen/arch/x86/mm/Makefile
> > +++ b/xen/arch/x86/mm/Makefile
> > @@ -11,11 +11,13 @@ obj-y += p2m.o p2m-pt.o
> >  obj-$(CONFIG_HVM) += p2m-ept.o p2m-pod.o
> >  obj-y += paging.o
> >  
> > -guest_walk_%.o: guest_walk.c Makefile
> > -   $(CC) $(c_flags) -DGUEST_PAGING_LEVELS=$* -c $< -o $@
> 
> The original rules didn't do anything special to arrange for the
> resulting kallsyms names; these arrangements instead live at the
> top of the respective source files, in the form of asm()-s.

They still are. I try to consolidate the number of location which have
command that build a target. Those guest_%.o object aren't special
enough to deserve to be built in a different way than every other
object. They do need a different make rule, but they can use the same
command.

Thanks,

-- 
Anthony PERARD