Re: [PATCH] build: tweak variable exporting for make 3.82

[Jan Beulich <jbeulich@xxxxxxxx>]

On 26.06.2020 17:32, Bertrand Marquis wrote:
> Hi Jan,
> 
>> On 26 Jun 2020, at 16:02, Jan Beulich <jbeulich@xxxxxxxx> wrote:
>>
>> While I've been running into an issue here only because of an additional
>> local change I'm carrying, to be able to override just the compiler in
>> $(XEN_ROOT)/.config (rather than the whole tool chain), in
>> config/StdGNU.mk:
>>
>> ifeq ($(filter-out default undefined,$(origin CC)),)
>>
>> I'd like to propose to nevertheless correct the underlying issue:
>> Exporting an unset variable changes its origin from "undefined" to
>> "file". This comes into effect because of our adding of -rR to
>> MAKEFLAGS, which make 3.82 wrongly applies also upon re-invoking itself
>> after having updated auto.conf{,.cmd}.
>>
>> Move the export statement past $(XEN_ROOT)/config/$(XEN_OS).mk inclusion
>> such that the variables already have their designated values at that
>> point, while retaining their initial origin up to the point they get
>> defined.
> 
> If I understand correctly you actually need this to be after 
> include $(XEN_ROOT)/Config.mk
> 
> Which actually includes the .config and the StdGNU.mk
> Maybe you could say this as $(XEN_ROOT)/config/$(XEN_OS).mk is not
> actually included directly in the Makefile itself ?

I thought it would be obvious enough, but since you ask, I've added
half a sentence.

> I tested the patch and it works on arm and x86 on my side.
> 
>>
>> Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
> Tested-by: Bertrand Marquis <bertrand.marquis@xxxxxxx>

Thanks much.

Jan