[OE-core] [PATCH] alsa-lib: Allow empty alsa-lib package for SDK

[Tanu Kaskinen]

On Thu, 2018-08-02 at 16:22 -0500, Joshua Watt wrote:
> Without ALLOW_EMPTY, the empty alsa-lib package (which gets culled)
> makes it fairly difficult to create an image that has libasound, then
> create an SDK from that image that has the proper development files.
> 
> If there is no alsa-lib package, the only way to get libasound on a
> target image is to do:
> 
>  IMAGE_INSTALL += "libasound"
> 
> This however causes a problem because all of the development files that
> would be desired in the SDK are located in alsa-lib-dev, which won't be
> included (because alsa-lib wasn't included). Without ALLOW_EMPTY_${PN},
> it is not possible to do:
> 
>  IMAGE_INSTALL += "alsa-lib"
> 
> because the package is empty and gets culled. Adding the ALLOW_EMPTY and
> then making alsa-lib RDEPEND on libasound solves this problem and allows
> alsa-lib to be installed on the target and have the correct development
> files in the SDK
> 
> Signed-off-by: Joshua Watt <JPEWhacker at gmail.com>
> ---
>  meta/recipes-multimedia/alsa/alsa-lib_1.1.6.bb | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/meta/recipes-multimedia/alsa/alsa-lib_1.1.6.bb b/meta/recipes-multimedia/alsa/alsa-lib_1.1.6.bb
> index 6364e9eafaa..581655c5349 100644
> --- a/meta/recipes-multimedia/alsa/alsa-lib_1.1.6.bb
> +++ b/meta/recipes-multimedia/alsa/alsa-lib_1.1.6.bb
> @@ -24,6 +24,13 @@ FILES_libasound = "${libdir}/libasound.so.*"
>  FILES_alsa-server = "${bindir}/*"
>  FILES_alsa-conf = "${datadir}/alsa/"
>  
> +# Create an alsa-lib package even though it is empty and make it RDEPEND on
> +# libasound for target builds. This makes it possible to sanely create a image
> +# that has libasound and then generate an SDK from that image that has
> +# alsa-lib-dev
> +ALLOW_EMPTY_${PN} = "1"
> +RDEPENDS_${PN}_class-target = "libasound"
> +
>  RDEPENDS_libasound = "alsa-conf"
>  
>  # alsa-lib gets automatically added to alsa-lib-dev dependencies, but the

Looks fine to me, although renaming alsa-lib-dev to libasound-dev would
seem like a sensible option too.

-- 
Tanu

https://www.patreon.com/tanuk
https://liberapay.com/tanuk