Re: [PATCH v4 04/10] cross-compilation: Introduce variable switch

[Jan Kiszka <jan.kiszka@web.de>]

On 2018-07-25 10:25, [ext] Henning Schild wrote:
> The way i understand the whole thing is that there are two meanings of
> ISAR_CROSS_COMPILE. On the image-level it enables the feature for
> every package. Some packages, the ones that do not support it, disable
> it for their build.
> 
> Would it be a good idea to come up with a different name for the two?
> 
> image:
>   ISAR_CROSS_COMPILE_IMAGE
> package:
>   ISAR_CROSS_COMPILE_RECIPE ?= ISAR_CROSS_COMPILE_IMAGE
> 

ISAR_CROSS_COMPILE has no direct relationship with images. It is a 
Variable that controls per package-generating recipe if cross 
compilation should be used.

You can set it globally, via local.conf, multiconfig settings or per 
target etc. Then those recipes who know that they are not compatible 
(unfulfilled build deps, build issues) should opt-out by overwriting the 
variable in the recipe file.

The problem comes from combinations: If recipe has a build-dependency on 
another recipe, generally only both can opt-out. But as we cannot 
foresee the combinations the user will choose when defining a target 
(which includes images), that user need to resolve any potential 
problems - e.g. by bbappend'ing ISAR_CROSS_COMPILE=0 to a recipe that 
services as build-dependency to a cross-incompatible recipe.

Jan