Re: [Xen-devel] [RFC v2] xen/arm: build: add missed dependency for head.S

[Wei Chen <wei.chen@xxxxxxxxxx>]

On 7 June 2016 at 21:18, Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx> wrote:
> On Tue, Jun 07, 2016 at 12:34:43PM +0800, Wei Chen wrote:
>> In current Xen build rules, the build system will only check the
>> dependencies in current folder and obj-y generated dependencies
>> in other folder.
>>
>> But Makefile may add some objects to ALL_OBJS. These objects may
>> be not in the same folder as Makefile. Use arch/arm/Makefile as
>> an example:
>>     ALL_OBJS := $(TARGET_SUBARCH)/head.o
>>
>> The head.o is not in the same folder as Makefile and is not listed
>> in obj-y. So, when we update the header files that had been included
>> in head.S. The build system would not check the dependency of head.S.
>> The head.S would not be re-compiled.
>>
>> In this patch, we will get objects added by Makefile and add their
>> dependencies to check list.
>>
>> Signed-off-by: Wei Chen <Wei.Chen@xxxxxxxxxx>
>> ---
>> v1 -> v2:
>> - Use a generic method instead of changing Makefiles
>> ---
>>  xen/Rules.mk | 11 ++++++++++-
>>  1 file changed, 10 insertions(+), 1 deletion(-)
>>
>> diff --git a/xen/Rules.mk b/xen/Rules.mk
>> index 961d533..fb3087c 100644
>> --- a/xen/Rules.mk
>> +++ b/xen/Rules.mk
>> @@ -95,12 +95,21 @@ include $(BASEDIR)/arch/$(TARGET_ARCH)/Rules.mk
>>  include Makefile
>>
>>  DEPS = .*.d
>> +
>> +# In obj-y and ALL_OBJS, there may have some objects are not in the
>
> You are missing a verb here.
>
> I think you mean to say 'there may be some objects which are not in the'
Thank you! it's my mistake.

>> +# same folder as Makefile, so we have to use gendep to generate
>> +# dependencies for them.
>> +DEP_OBJS = $(obj-y)
>> +
>> +# Extract objects from ALL_OBJS added by Makefile.
>> +DEP_OBJS += $(filter-out %built_in.o,$(ALL_OBJS))
>> +
>>  define gendep
>>      ifneq ($(1),$(subst /,:,$(1)))
>>          DEPS += $(dir $(1)).$(notdir $(1)).d
>>      endif
>>  endef
>> -$(foreach o,$(filter-out %/,$(obj-y)),$(eval $(call gendep,$(o))))
>> +$(foreach o,$(filter-out %/,$(DEP_OBJS)),$(eval $(call gendep,$(o))))
>>
>>  # Ensure each subdirectory has exactly one trailing slash.
>>  subdir-n := $(patsubst %,%/,$(patsubst %/,%,$(subdir-n) $(subdir-)))
>> --
>> 2.7.4
>>
>>
>> _______________________________________________
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>> Xen-devel@xxxxxxxxxxxxx
>> http://lists.xen.org/xen-devel

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