Re: [XEN PATCH v9 24/30] build: grab common EFI source files in arch specific dir

[Jan Beulich <jbeulich@xxxxxxxx>]

On 03.03.2022 16:41, Anthony PERARD wrote:
> On Thu, Mar 03, 2022 at 11:37:08AM +0100, Jan Beulich wrote:
>> On 25.01.2022 12:00, Anthony PERARD wrote:
>>> --- a/xen/arch/x86/Makefile
>>> +++ b/xen/arch/x86/Makefile
>>> @@ -77,8 +77,9 @@ obj-$(CONFIG_COMPAT) += x86_64/platform_hypercall.o
>>>  obj-y += sysctl.o
>>>  endif
>>>  
>>> -# Allows "clean" to descend into boot/
>>> +# Allows "clean" to descend
>>>  subdir- += boot
>>> +subdir- += efi
>>
>> No similar addition is needed for Arm?
> 
> No, because Arm already have "obj-$(CONFIG_ARM_64) += efi/", which has
> the same effect on clean.
> 
> Make clean doesn't use ${ALL_OBJS} to find out which directory to clean, so
> adding "subdir-" is needed at the moment.

Oh, I see.

>>> --- /dev/null
>>> +++ b/xen/common/efi/efi-common.mk
>>> @@ -0,0 +1,15 @@
>>> +EFIOBJ-y := boot.init.o pe.init.o ebmalloc.o runtime.o
>>> +EFIOBJ-$(CONFIG_COMPAT) += compat.o
>>> +
>>> +CFLAGS-y += -fshort-wchar
>>> +CFLAGS-y += -iquote $(srctree)/common/efi
>>> +
>>> +# Part of the command line transforms $(obj) in to a relative reverted 
>>> path.
>>> +# e.g.: It transforms "dir/foo/bar" into successively
>>> +#       "dir foo bar", ".. .. ..", "../../.."
>>> +$(obj)/%.c: $(srctree)/common/efi/%.c FORCE
>>> +   $(Q)ln -nfs $(subst $(space),/,$(patsubst %,..,$(subst /, 
>>> ,$(obj))))/common/efi/$(<F) $@
>>
>> What is the "reverted" about in the comment? Also (nit) I think you want
>> s/in to/into/.
> 
> I've tried to described in the single word that the result is a relative
> path that goes in the opposite direction to the original relative path.
> Instead of going down, it goes up the hierarchy of directories.
> Maybe "reversed" would be better? Do you have other suggestion?

I'd simply omit the word. In case you're fine with that, I'd be happy
to adjust while committing.

Jan