[Buildroot] [PATCH] package/Makefile.in: export O= to post-build/image scripts for out-of-tree builds

[Arnout Vandecappelle]

On 17-07-17 23:32, Peter Korsgaard wrote:
>>>>>> "Arnout" == Arnout Vandecappelle <arnout at mind.be> writes:
> 
>  > On 14-07-17 15:04, Peter Korsgaard wrote:
>  >> Sometimes it can be interesting to call back into buildroot from a
>  >> post-build/image script (E.G. make printvars or similar). For this to work
>  >> correctly with out-of-tree builds we need to pass O= to make, but this is
>  >> currently not available in the environment of post-build/image scripts.
>  >> 
>  >> In concept, O could be derrived from BUILD_DIR (E.G. by stripping /build),
>  >> but directly exporting O is cleaner.
>  >> 
>  >> O= cannot be exported globally as it interferes with various build systems,
>  >> so instead add it to EXTRA_ENV.
> 
>  >  I'm too late with this comment, but why is BASE_DIR not sufficient? It is
>  > already exported, and it is set to:
> 
>  > BASE_DIR := $(CANONICAL_O)
> 
> Yes, that can also work - Even though it is less obvious that you should
> run make O=${BASE_DIR} inside the post build/image scripts, instead of
> make O=$O

 OK, but having both exported seems a bit silly...


>  >  O has the problem that it's too risky to lead to conflicts IMO.
> 
> Even for post build/image scripts? What use cases do you have in mind
> where there could be conflicts?

 True, in EXTRA_ENV the risk is minimal - especially since Kbuild and
derivatives (like Buildroot) ignore an O passed through the environment.

 Regards,
 Arnout


-- 
Arnout Vandecappelle                          arnout at mind be
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