Re: [Qemu-devel] [PATCH v6 2/8] rule.mak: allow per object cflags and libs

[Fam Zheng]

On Thu, 09/12 08:34, Paolo Bonzini wrote:
> Il 12/09/2013 04:52, Fam Zheng ha scritto:
> >>> > >  define unnest-dir
> >>> > >  $(foreach var,$(nested-vars),$(call push-var,$(var),$1/))
> >>> > >  $(eval obj-parent-$1 := $(obj))
> >>> > >  $(eval obj := $(if $(obj),$(obj)/$1,$1))
> >>> > >  $(eval include $(SRC_PATH)/$1/Makefile.objs)
> >>> > > +$(foreach v,$(nested-vars),$(call fix-obj-vars,$v,$(if 
> >>> > > $(obj),$(obj)/)))
> >>> > >  $(eval obj := $(obj-parent-$1))
> >>> > >  $(eval obj-parent-$1 := )
> >>> > >  $(foreach var,$(nested-vars),$(call pop-var,$(var),$1/))
> >>> > > 
> >> > 
> >> > I'm not sure this will work for targets in the toplevel directory when
> >> > obj-base is not empty.  This can be fixed later though, as part of a
> >> > general revamping of obj-base.  Please add a FIXME comment.
> >> > 
> > I'm not sure about the problem, can you give an example, so I can be 
> > specific
> > in the comment?
> 
> Can you try using vl.o-cflags instead of a per-target QEMU_CFLAGS?  I
> think it won't work, because the toplevel Makefile.objs is included
> directly and not through unnest-dir.
> 
I think this case works. Only in subdir %-cflags relies on unnest-vars to
prefix them, toplevel objects don't need this:

In toplevel Makefile.objs,

    vl.o-cflags = -DTEST_CFLAGS_FOR_VL_O

Then,

    rm vl.o ; make vl.o V=1 | grep TEST_CFLAGS_FOR_VL_O
    cc <hidden options>  -DTEST_CFLAGS_FOR_VL_O -c -o vl.o vl.c

Fam