[Buildroot] [PATCH 1/3] Makefile: use absolute paths to BR2_EXTERNAL

[Arnout Vandecappelle <arnout@mind.be>]

On 02/02/14 11:23, Yann E. MORIN wrote:
> Arnoud, All,
>
> On 2014-01-27 18:26 +0100, Arnout Vandecappelle spake thusly:
>> On 22/01/14 21:59, Yann E. MORIN wrote:
>>> +  _BR2_EXTERNAL = $(shell cd $(BR2_EXTERNAL) >/dev/null 2>&1 && pwd)
>>> +  ifeq ($(_BR2_EXTERNAL),)
>>> +    ifeq ($(patsubst /%,/,$(BR2_EXTERNAL)),/)
>>> +      $(error BR2_EXTERNAL='$(BR2_EXTERNAL)' does not exist)
>>> +    else
>>> +      $(error BR2_EXTERNAL='$(BR2_EXTERNAL)' does not exist, relatively to $(TOPDIR))
>>
>>   I don't think the limited explanation "relatively to $(TOPDIR)" warrants
>> the additional complexity of patsubsting stuff.
>
> Well, we want to tell the user why w edid not find his BR2_EXTERNAL.
> And since it can be tricky to understand that a relative path is not
> found, we do want to highlight that fact in the error message.

  For me it would be sufficient to make it "relative to the buildroot 
directory" for both the absolute and relative case.

>
>>> +    endif
>>> +  endif
>>> +  BR2_EXTERNAL := $(_BR2_EXTERNAL)
>>
>>   AFAICS there is no need to have a separate _BR2_EXTERNAL, since we'll
>> anyway error out if it is empty.
>
> I used an intermediate, since I want to display the user-supplied path
> in the error message, not the one we found (or did not find).
>
>>   So, I'd propose:
>>
>> override BR2_EXTERNAL := $(shell cd $(BR2_EXTERNAL) >/dev/null 2>&1 && pwd)
>> ifeq ($(BR2_EXTERNAL),)
>> 	$(error BR2_EXTERNAL directory '$(BR2_EXTERNAL)' does not exist)
>> endif
>
> Uh? In this case $(BR2_EXTERNAL) would be empty in the error message, no?

  Silly me, of course!

  Regards,
  Arnout

-- 
Arnout Vandecappelle                          arnout at mind be
Senior Embedded Software Architect            +32-16-286500
Essensium/Mind                                http://www.mind.be
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