Re: [Qemu-devel] [PATCH 3/9] pc: rebuild ACPI hex files if included *.dsl are touched

["Michael S. Tsirkin" <mst@redhat.com>]

On Sat, Dec 28, 2013 at 11:30:46PM +0100, Igor Mammedov wrote:
> Signed-off-by: Igor Mammedov <imammedo@redhat.com>
> ---
>  hw/i386/Makefile.objs | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/hw/i386/Makefile.objs b/hw/i386/Makefile.objs
> index 09ac433..edf5256 100644
> --- a/hw/i386/Makefile.objs
> +++ b/hw/i386/Makefile.objs
> @@ -16,7 +16,12 @@ iasl-option=$(shell if test -z "`$(1) $(2) 2>&1 > /dev/null`" \
>  
>  ifdef IASL
>  #IASL Present. Generate hex files from .dsl
> -hw/i386/%.hex: $(SRC_PATH)/hw/i386/%.dsl $(SRC_PATH)/scripts/acpi_extract_preprocess.py $(SRC_PATH)/scripts/acpi_extract.py
> +DSL_DEPS = $(SRC_PATH)/hw/i386/%.dsl \
> +	$(SRC_PATH)/scripts/acpi_extract_preprocess.py \
> +	$(SRC_PATH)/scripts/acpi_extract.py \
> +	$(SRC_PATH)/hw/i386/acpi-dsdt-*.dsl
> +
> +hw/i386/%.hex: $(DSL_DEPS)
>  	$(call quiet-command, cpp -P $< -o $*.dsl.i.orig, "  CPP $(TARGET_DIR)$*.dsl.i.orig")
>  	$(call quiet-command, $(PYTHON) $(SRC_PATH)/scripts/acpi_extract_preprocess.py $*.dsl.i.orig > $*.dsl.i, "  ACPI_PREPROCESS $(TARGET_DIR)$*.dsl.i")
>  	$(call quiet-command, $(IASL) $(call iasl-option,$(IASL),-Pn,) -vs -l -tc -p $* $*.dsl.i $(if $(V), , > /dev/null) 2>&1 ,"  IASL $(TARGET_DIR)$*.dsl.i")

It's generally nasty to have rules that generate files already in
the source tree. In partuclar people expect make clean to get
back the original tree.
How about only doing this when some variable is defined?

> -- 
> 1.8.4.2