[Buildroot] [PATCH] infra/pkg-virtual: validate only one provider provides an implementation

[Thomas Petazzoni]

Dear Yann E. MORIN,

On Tue, 13 May 2014 23:47:50 +0200, Yann E. MORIN wrote:

> +# Providers shall call this function with all the FEATURES they provide
> +# 	$(eval $(call virt-provides,FEATURE[ FEATURE ...]))
> +# where FEATURE has a corresponding BR2_PACKAGE_HAS_FEATURE
> +define virt-provides
> +$(foreach p,$(1),\
> +ifneq ($$(BR2_PACKAGE_PROVIDES_$(p)),$(pkgname))$(sep)\
> +$$(error $(pkgname is trying to override $$(BR2_PACKAGE_PROVIDES_$(p)) to provide $(p)))$(sep)\
> +endif$(sep))
> +endef
>  
>  ################################################################################
>  # inner-virtual-package -- defines the dependency rules of the virtual
> diff --git a/package/rpi-userland/rpi-userland.mk b/package/rpi-userland/rpi-userland.mk
> index f6e4443..86125f2 100644
> --- a/package/rpi-userland/rpi-userland.mk
> +++ b/package/rpi-userland/rpi-userland.mk
> @@ -16,4 +16,7 @@ define RPI_USERLAND_POST_TARGET_CLEANUP
>  endef
>  RPI_USERLAND_POST_INSTALL_TARGET_HOOKS += RPI_USERLAND_POST_TARGET_CLEANUP
>  
> +# rpi-userland is a provider for those features:
> +$(eval $(call virt-provides,LIBEGL LIBGLES OPENVG OPENMAX))
> +
>  $(eval $(cmake-package))

Just thinking out loud: isn't it possible to instead check if
<pkg>_DEPENDENCIES for each virtual package contains only one word?

Thomas
-- 
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com