[RFC,2/3] Makefile: add handling of software stacks

Software stacks are a new way to express a bundle of configuration
options that should be used togheter.
A software stack is orthogonal to a classic buildroot config: a software
stack indeed could be shared beetween multiple configs.

A software stack could be used with standard buildroot tools, like:

make qt5-fb_stack

The fragment called qt5-fb_stack is merged inside current .config and
everithing is checked to produce a valid configurationqt5-fb_stack is
merged inside current .config and everithing is checked to produce a
valid configuration.

Signed-off-by: Angelo Compagnucci <angelo.compagnucci@gmail.com>
---
 Makefile | 40 ++++++++++++++++++++++++++++++++++++++--
 1 file changed, 38 insertions(+), 2 deletions(-)

On 10-10-17 22:43, Angelo Compagnucci wrote:
> Software stacks are a new way to express a bundle of configuration
> options that should be used togheter.

 together

> A software stack is orthogonal to a classic buildroot config: a software
> stack indeed could be shared beetween multiple configs.

 between

> 
> A software stack could be used with standard buildroot tools, like:
> 
> make qt5-fb_stack
> 
> The fragment called qt5-fb_stack is merged inside current .config and
> everithing is checked to produce a valid configurationqt5-fb_stack is

 everything                                       missing space

> merged inside current .config and everithing is checked to produce a

 everything

> valid configuration.
> 
> Signed-off-by: Angelo Compagnucci <angelo.compagnucci@gmail.com>
> ---
>  Makefile | 40 ++++++++++++++++++++++++++++++++++++++--
>  1 file changed, 38 insertions(+), 2 deletions(-)
> 
> diff --git a/Makefile b/Makefile
> index 02f7cda..27283b8 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -128,7 +128,7 @@ export BR2_VERSION_FULL := $(BR2_VERSION)$(shell $(TOPDIR)/support/scripts/setlo
>  
>  # List of targets and target patterns for which .config doesn't need to be read in
>  noconfig_targets := menuconfig nconfig gconfig xconfig config oldconfig randconfig \
> -	defconfig %_defconfig allyesconfig allnoconfig alldefconfig silentoldconfig release \
> +	defconfig %_defconfig %_stack allyesconfig allnoconfig alldefconfig silentoldconfig release \
>  	randpackageconfig allyespackageconfig allnopackageconfig \
>  	print-version olddefconfig distclean manual manual-%
>  
> @@ -146,7 +146,7 @@ nobuild_targets := source %-source source-check \
>  	clean distclean help show-targets graph-depends \
>  	%-graph-depends %-show-depends %-show-version \
>  	graph-build graph-size list-defconfigs \
> -	savedefconfig printvars
> +	list-stacks savedefconfig printvars
>  ifeq ($(MAKECMDGOALS),)
>  BR_BUILDING = y
>  else ifneq ($(filter-out $(nobuild_targets),$(MAKECMDGOALS)),)
> @@ -919,6 +919,12 @@ define percent_defconfig
>  endef
>  $(eval $(foreach d,$(call reverse,$(TOPDIR) $(BR2_EXTERNAL_DIRS)),$(call percent_defconfig,$(d))$(sep)))
>  
> +define percent_stack
> +%_stack: $(1)/stacks/%_stack
> +	$(TOPDIR)/support/kconfig/merge_config.sh -b -O $(BASE_DIR) $(BR2_CONFIG) $(1)/stacks/$$@
> +endef
> +$(eval $(foreach d,$(call reverse,$(TOPDIR) $(BR2_EXTERNAL_DIRS)),$(call percent_stack,$(d))$(sep)))

 This could be refactored more, by adding two arguments to percent_defconfig
(configs and _defconfig for defconfig, and stacks and _stack for stacks). The
macro should then obviously be renamed.

> +
>  savedefconfig: $(BUILD_DIR)/buildroot-config/conf prepare-kconfig
>  	@$(COMMON_CONFIG_ENV) $< \
>  		--savedefconfig=$(if $(DEFCONFIG),$(DEFCONFIG),$(CONFIG_DIR)/defconfig) \
> @@ -1039,6 +1045,7 @@ help:
>  	@echo '  graph-depends          - generate graph of the dependency tree'
>  	@echo '  graph-size             - generate stats of the filesystem size'
>  	@echo '  list-defconfigs        - list all defconfigs (pre-configured minimal systems)'
> +	@echo '  list-stacks            - list all stacks (pre-configured group of packages)'
>  	@echo
>  	@echo 'Miscellaneous:'
>  	@echo '  source                 - download all sources needed for offline-build'
> @@ -1075,6 +1082,26 @@ define list-defconfigs
>  	$${first} || printf "\n"
>  endef
>  
> +# List the stacks files
> +# $(1): base directory
> +# $(2): br2-external name, empty for bundled
> +define list-stacks
> +	@first=true; \
> +	for stack in $(1)/stacks/*_stack; do \
> +		[ -f "$${stack}" ] || continue; \
> +		if $${first}; then \
> +			if [ "$(2)" ]; then \
> +				printf 'External stacks in "$(call qstrip,$(2))":\n'; \
> +			else \
> +				printf "Built-in stacks:\n"; \
> +			fi; \
> +			first=false; \
> +		fi; \
> +		printf "  %-35s - %s\n" ""$${stack##*/}"" "$$(head -n1 $${stack} | sed 's/^##*//' )"; \
> +	done; \
> +	$${first} || printf "\n"
> +endef

 Same here, can be refactored with list-defconfigs by adding extra arguments.

> +
>  # We iterate over BR2_EXTERNAL_NAMES rather than BR2_EXTERNAL_DIRS,
>  # because we want to display the name of the br2-external tree.
>  .PHONY: list-defconfigs
> @@ -1084,6 +1111,15 @@ list-defconfigs:
>  		$(call list-defconfigs,$(BR2_EXTERNAL_$(name)_PATH),\
>  			$(BR2_EXTERNAL_$(name)_DESC))$(sep))
>  
> +# We iterate over BR2_EXTERNAL_NAMES rather than BR2_EXTERNAL_DIRS,
> +# because we want to display the name of the br2-external tree.
> +.PHONY: list-stacks
> +list-stacks:
> +	$(call list-stacks,$(TOPDIR))
> +	$(foreach name,$(BR2_EXTERNAL_NAMES),\
> +		$(call list-stacks,$(BR2_EXTERNAL_$(name)_PATH),\
> +			$(BR2_EXTERNAL_$(name)_DESC))$(sep))

 This could also be factored into a new macro.

 Regards,
 Arnout

> +
>  release: OUT = buildroot-$(BR2_VERSION)
>  
>  # Create release tarballs. We need to fiddle a bit to add the generated
>

On 10-10-17 22:43, Angelo Compagnucci wrote:
> +define percent_stack
> +%_stack: $(1)/stacks/%_stack
> +	$(TOPDIR)/support/kconfig/merge_config.sh -b -O $(BASE_DIR) $(BR2_CONFIG) $(1)/stacks/$$@
> +endef
> +$(eval $(foreach d,$(call reverse,$(TOPDIR) $(BR2_EXTERNAL_DIRS)),$(call percent_stack,$(d))$(sep)))

 I forgot to mention: there's a future problem here. When we finally enable
top-level parallel build, the different stacks are going to overwrite each other
when you call it as "make stack1 stack2 stack3".

 Regards,
 Arnout