[Buildroot] [PATCH 02/16 v3] core: commonalise the bundled and br2-external %_defconfig rules

[Romain Naour <romain.naour@gmail.com>]

Hi Yann, All,

Le 17/07/2016 ? 12:34, Yann E. MORIN a ?crit :
> The code for both cases is exactly the same, and only differs in the
> location where defconfig files are looked for.
> 
> We use an intermediate macro to generate the corresponding rules,
> because directly generating the rules is ugly and needs lots of escaping
> and double-dollar-ing for the $(eval ...) and $(foreach ...) calls to
> play nicely together.
> 
> Furthermore, that will be tremendously useful when we support multiple
> br2-external trees.

This patch is similar to the one sent by Sam Bobroff [1]. I reviewed it during
the summer camp but it was not applied since it was in a series we rejected.

Reviewed-by: Romain Naour <romain.naour@gmail.com>

Best regards,
Romain

[1] http://lists.busybox.net/pipermail/buildroot/2016-June/165382.html

> 
> Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
> Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
> Cc: Peter Korsgaard <jacmet@uclibc.org>
> Cc: Thomas De Schampheleire <patrickdepinguin@gmail.com>
> Cc: Arnout Vandecappelle <arnout@mind.be>
> 
> ---
> Changes v2 -> v3:
>   - use lower-case macro  (Arnout)
>   - move comment in the generated rule  (Arnout)
> ---
>  Makefile | 15 +++++++--------
>  1 file changed, 7 insertions(+), 8 deletions(-)
> 
> diff --git a/Makefile b/Makefile
> index af2d982..7c0dcb1 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -847,14 +847,13 @@ olddefconfig: $(BUILD_DIR)/buildroot-config/conf outputmakefile
>  defconfig: $(BUILD_DIR)/buildroot-config/conf outputmakefile
>  	@$(COMMON_CONFIG_ENV) $< --defconfig$(if $(DEFCONFIG),=$(DEFCONFIG)) $(CONFIG_CONFIG_IN)
>  
> -# Override the BR2_DEFCONFIG from COMMON_CONFIG_ENV with the new defconfig
> -%_defconfig: $(BUILD_DIR)/buildroot-config/conf $(TOPDIR)/configs/%_defconfig outputmakefile
> -	@$(COMMON_CONFIG_ENV) BR2_DEFCONFIG=$(TOPDIR)/configs/$@ \
> -		$< --defconfig=$(TOPDIR)/configs/$@ $(CONFIG_CONFIG_IN)
> -
> -%_defconfig: $(BUILD_DIR)/buildroot-config/conf $(BR2_EXTERNAL)/configs/%_defconfig outputmakefile
> -	@$(COMMON_CONFIG_ENV) BR2_DEFCONFIG=$(BR2_EXTERNAL)/configs/$@ \
> -		$< --defconfig=$(BR2_EXTERNAL)/configs/$@ $(CONFIG_CONFIG_IN)
> +define percent_defconfig
> +%_defconfig: $(BUILD_DIR)/buildroot-config/conf $(1)/configs/%_defconfig outputmakefile
> +	# Override the BR2_DEFCONFIG from COMMON_CONFIG_ENV with the new defconfig
> +	@$$(COMMON_CONFIG_ENV) BR2_DEFCONFIG=$(1)/configs/$$@ \
> +		$$< --defconfig=$(1)/configs/$$@ $$(CONFIG_CONFIG_IN)
> +endef
> +$(eval $(foreach d,$(TOPDIR) $(BR2_EXTERNAL),$(call percent_defconfig,$(d))$(sep)))
>  
>  savedefconfig: $(BUILD_DIR)/buildroot-config/conf outputmakefile
>  	@$(COMMON_CONFIG_ENV) $< \
>