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

[Julien Grall <julien@xxxxxxx>]

Hi Jan,

On 21/09/2020 11:17, Jan Beulich wrote:
> On 14.09.2020 12:15, 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".
> >
> > Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
> > ---
> >   xen/arch/arm/Makefile |  4 +++-
> >   xen/arch/x86/Makefile | 18 ++++++++++--------
> >   2 files changed, 13 insertions(+), 9 deletions(-)
> May I ask for an Arm-side ack (or otherwise) here, please?
Acked-by: Julien Grall <jgrall@xxxxxxxxxx>

Cheers,

> Jan
>
> > diff --git a/xen/arch/arm/Makefile b/xen/arch/arm/Makefile
> > index 51173d97127e..296c5e68bbc3 100644
> > --- a/xen/arch/arm/Makefile
> > +++ b/xen/arch/arm/Makefile
> > @@ -95,12 +95,14 @@ prelink_lto.o: $(ALL_OBJS)
> >   
> >   # Link it with all the binary objects
> >   prelink.o: $(patsubst %/built_in.o,%/built_in_bin.o,$(ALL_OBJS)) prelink_lto.o
> > -       $(LD) $(XEN_LDFLAGS) -r -o $@ $^
> > +       $(call if_changed,ld)
> >   else
> >   prelink.o: $(ALL_OBJS) FORCE
> >         $(call if_changed,ld)
> >   endif
> >   
> > +targets += prelink.o
> > +
> >   $(TARGET)-syms: prelink.o xen.lds
> >         $(LD) $(XEN_LDFLAGS) -T xen.lds -N prelink.o \
> >             $(BASEDIR)/common/symbols-dummy.o -o $(@D)/.$(@F).0
> > diff --git a/xen/arch/x86/Makefile b/xen/arch/x86/Makefile
> > index 74152f2a0dad..9b368632fb43 100644
> > --- a/xen/arch/x86/Makefile
> > +++ b/xen/arch/x86/Makefile
> > @@ -136,19 +136,21 @@ prelink_lto.o: $(ALL_OBJS)
> >         $(LD_LTO) -r -o $@ $^
> >   
> >   # Link it with all the binary objects
> > -prelink.o: $(patsubst %/built_in.o,%/built_in_bin.o,$(ALL_OBJS)) prelink_lto.o 
> > $(EFI_OBJS-y)
> > -       $(LD) $(XEN_LDFLAGS) -r -o $@ $^
> > +prelink.o: $(patsubst %/built_in.o,%/built_in_bin.o,$(ALL_OBJS)) prelink_lto.o 
> > $(EFI_OBJS-y) FORCE
> > +       $(call if_changed,ld)
> >   
> > -prelink-efi.o: $(patsubst %/built_in.o,%/built_in_bin.o,$(ALL_OBJS)) prelink_lto.o
> > -       $(LD) $(XEN_LDFLAGS) -r -o $@ $^
> > +prelink-efi.o: $(patsubst %/built_in.o,%/built_in_bin.o,$(ALL_OBJS)) 
> > prelink_lto.o FORCE
> > +       $(call if_changed,ld)
> >   else
> > -prelink.o: $(ALL_OBJS) $(EFI_OBJS-y)
> > -       $(LD) $(XEN_LDFLAGS) -r -o $@ $^
> > +prelink.o: $(ALL_OBJS) $(EFI_OBJS-y) FORCE
> > +       $(call if_changed,ld)
> >   
> > -prelink-efi.o: $(ALL_OBJS)
> > -       $(LD) $(XEN_LDFLAGS) -r -o $@ $^
> > +prelink-efi.o: $(ALL_OBJS) FORCE
> > +       $(call if_changed,ld)
> >   endif
> >   
> > +targets += prelink.o prelink-efi.o
> > +
> >   $(TARGET)-syms: prelink.o xen.lds
> >         $(LD) $(XEN_LDFLAGS) -T xen.lds -N prelink.o $(build_id_linker) \
> >             $(BASEDIR)/common/symbols-dummy.o -o $(@D)/.$(@F).0
--
Julien Grall