Re: [XEN PATCH v7 21/51] build: set ALL_OBJS to main Makefile; move prelink.o to main Makefile

[Anthony PERARD <anthony.perard@xxxxxxxxxx>]

On Mon, Oct 11, 2021 at 01:31:59PM +0200, Jan Beulich wrote:
> On 24.08.2021 12:50, Anthony PERARD wrote:
> > --- a/xen/Makefile
> > +++ b/xen/Makefile
> > @@ -271,8 +271,21 @@ CFLAGS += -flto
> >  LDFLAGS-$(CONFIG_CC_IS_CLANG) += -plugin LLVMgold.so
> >  endif
> >  
> > +# Note that link order matters!
> > +ALL_OBJS-y                := common/built_in.o
> > +ALL_OBJS-y                += drivers/built_in.o
> > +ALL_OBJS-y                += lib/built_in.o
> > +ALL_OBJS-y                += xsm/built_in.o
> > +ALL_OBJS-y                += arch/$(TARGET_ARCH)/built_in.o
> > +ALL_OBJS-$(CONFIG_CRYPTO) += crypto/built_in.o
> > +
> > +ALL_LIBS-y                := lib/lib.a
> > +
> >  include $(BASEDIR)/arch/$(TARGET_ARCH)/arch.mk
> >  
> > +export ALL_OBJS := $(ALL_OBJS-y)
> > +export ALL_LIBS := $(ALL_LIBS-y)
> > +
> >  # define new variables to avoid the ones defined in Config.mk
> >  export XEN_CFLAGS := $(CFLAGS)
> >  export XEN_AFLAGS := $(AFLAGS)
> > @@ -393,7 +406,7 @@ $(TARGET): FORCE
> >     $(MAKE) -f $(BASEDIR)/Rules.mk -C include
> >     $(MAKE) -f $(BASEDIR)/Rules.mk -C arch/$(TARGET_ARCH) include
> >     $(MAKE) -f $(BASEDIR)/Rules.mk 
> > arch/$(TARGET_ARCH)/include/asm/asm-offsets.h
> > -   $(MAKE) -f $(BASEDIR)/Rules.mk -C arch/$(TARGET_ARCH) $@
> > +   $(MAKE) -f $(BASEDIR)/Rules.mk $@
> 
> This merely results in what was previously invoked from here now getting
> invoked from the very bottom of build.mk. I'm afraid I don't see why this
> is a useful change to make.

Would you rather have this following change?

    @@ -393,7 +406,8 @@ $(TARGET): FORCE
        $(MAKE) -f $(BASEDIR)/Rules.mk -C include
        $(MAKE) -f $(BASEDIR)/Rules.mk -C arch/$(TARGET_ARCH) include
        $(MAKE) -f $(BASEDIR)/Rules.mk 
arch/$(TARGET_ARCH)/include/asm/asm-offsets.h
    +   $(MAKE) -f $(BASEDIR)/Rules.mk prelink.o
        $(MAKE) -f $(BASEDIR)/Rules.mk -C arch/$(TARGET_ARCH) $@

That would probably be fine.

> > --- a/xen/build.mk
> > +++ b/xen/build.mk
> > @@ -56,3 +56,27 @@ arch/$(TARGET_ARCH)/include/asm/asm-offsets.h: 
> > asm-offsets.s
> >       sed -rne "/^[^#].*==>/{s:.*==>(.*)<==.*:\1:; s: [\$$#]: :; p;}"; \
> >       echo ""; \
> >       echo "#endif") <$< >$@
> > +
> > +# head.o is built by descending into arch/arm/$(TARGET_SUBARCH), depends 
> > on the
> > +# part of $(ALL_OBJS) that will eventually recurse into $(TARGET_SUBARCH)/ 
> > and
> > +# build head.o
> > +arch/arm/$(TARGET_SUBARCH)/head.o: arch/arm/built_in.o
> > +arch/arm/$(TARGET_SUBARCH)/head.o: ;
> 
> This previously lived in an Arm-specific file. Moving this here in the
> given, still Arm-specific form is imo a no-go when done alongside all
> the other good changes you're making. Is there a reason this can't go
> into xen/arch/arm/arch.mk?

This is temporary and it is removed in patch
    "build: build everything from the root dir, use obj=$subdir"
but I could move it to "arch/arm/Rules.mk" I think.

Thanks,

-- 
Anthony PERARD