Re: [PATCH for-xen-4.5 v4 02/18] x86/boot: fix reloc.S build dependencies

[Andrew Cooper <andrew.cooper3@citrix.com>]

On 17/10/14 15:11, Daniel Kiper wrote:
> reloc.S is not rebuild if header included
> in reloc.c is updated. Fix this issue.
>
> Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>
> ---
>  xen/arch/x86/boot/Makefile   |    6 +++++-
>  xen/arch/x86/boot/build32.mk |    3 ++-
>  2 files changed, 7 insertions(+), 2 deletions(-)
>
> diff --git a/xen/arch/x86/boot/Makefile b/xen/arch/x86/boot/Makefile
> index 13f4a66..3cab36a 100644
> --- a/xen/arch/x86/boot/Makefile
> +++ b/xen/arch/x86/boot/Makefile
> @@ -1,8 +1,12 @@
>  obj-bin-y += head.o
>  
> +RELOC_DEPS = $(BASEDIR)/include/asm-x86/config.h $(BASEDIR)/include/xen/multiboot.h

What is wrong with the normal gcc method of using "-MMD -MF" ?  It would
avoid duplicating the list of includes in the Makefile.

~Andrew

> +
> +export RELOC_DEPS
> +
>  head.o: reloc.S
>  
>  %.S: %.c
>  	$(MAKE) -f build32.mk $@
>  
> -reloc.S: head.S
> +reloc.S: $(RELOC_DEPS)
> diff --git a/xen/arch/x86/boot/build32.mk b/xen/arch/x86/boot/build32.mk
> index a36f620..809f296 100644
> --- a/xen/arch/x86/boot/build32.mk
> +++ b/xen/arch/x86/boot/build32.mk
> @@ -30,5 +30,6 @@ CFLAGS := $(filter-out -flto,$(CFLAGS))
>  			esac; \
>  		done
>  
> -reloc.o: $(BASEDIR)/include/asm-x86/config.h
> +reloc.o: $(RELOC_DEPS)
> +
>  .PRECIOUS: %.bin %.lnk