[Buildroot] [PATCH v2 1/5] kconfig-package: add support for config fragments

[Arnout Vandecappelle <arnout@mind.be>]

On 28/04/15 16:34, Floris Bos wrote:
> Adds functionality to the kconfig infrastructure to merge additional
> configuration fragment files to the main configuration file of
> kconfig packages, using support/kconfig/merge_config.sh
> 
> Typical use-case is when you want your configuration to be
> kept in sync with an upstream (def)config file, but do require
> some minor local modifications.
> 
> Disables -update-config and -update-defconfig targets when
> fragment files are set.
> 
> Signed-off-by: Floris Bos <bos@je-eigen-domein.nl>

 Some trivial feedback below, with that:
  Acked-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
Tested-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
 Build test of linux-configure after applying patch 2, verified that the config
options in the fragment end up in the configuration, checked that
linux-update-{def,}config errors out with fragment and works without fragments,

 When the fragment file doesn't exist, you get:

make: *** No rule to make target 'test_fragment', needed by
'/home/arnout/src/buildroot/output/build/linux-3.15.10/.config'.  Stop.

which is good enough for me.

> 
> ---
> v2:
> 
> - use shell commands to print error message when
> update-(def)config target is used while fragment files are set.
> 
> - document changes to kconfig infrastructure.
> ---
>  docs/manual/adding-packages-kconfig.txt | 11 +++++++++++
>  package/pkg-kconfig.mk                  | 14 ++++++++++----
>  2 files changed, 21 insertions(+), 4 deletions(-)
> 
> diff --git a/docs/manual/adding-packages-kconfig.txt b/docs/manual/adding-packages-kconfig.txt
> index e87d393..dc9ea11 100644
> --- a/docs/manual/adding-packages-kconfig.txt
> +++ b/docs/manual/adding-packages-kconfig.txt
> @@ -36,6 +36,12 @@ This snippet creates the following make targets:
>  
>  * +foo-update-config+, which copies the configuration back to the source
>    configuration file.
> +  It is not possible to use this target when fragment files are set.

 There is not reason to start a new line - in the generated manual, the line
split will vanish anyway.

> +
> +* +foo-update-defconfig+, which copies the configuration back to the source
> +  configuration file. The configuration file will only list the
> +  options that differ from the default values.

 Word wrapping is a bit weird here.

> +  It is not possible to use this target when fragment files are set.
>  
>  and ensures that the source configuration file is copied to the build
>  directory at the right moment.
> @@ -46,6 +52,11 @@ be set to suit the needs of the package under consideration:
>  * +FOO_KCONFIG_EDITORS+: a space-separated list of kconfig editors to
>    support, for example 'menuconfig xconfig'. By default, 'menuconfig'.
>  
> +* +FOO_KCONFIG_FRAGMENT_FILES+: a space-separated list of configuration
> +  fragment files that are merged to the main configuration file.
> +  Fragment files are typically used when there is a desire to stay in sync
> +  with an upstream (def)config file, with some minor modifications.
> +
>  * +FOO_KCONFIG_OPTS+: extra options to pass when calling the kconfig
>    editors. This may need to include '$(FOO_MAKE_OPTS)', for example. By
>    default, empty.
> diff --git a/package/pkg-kconfig.mk b/package/pkg-kconfig.mk
> index 8361064..21fbfdb 100644
> --- a/package/pkg-kconfig.mk
> +++ b/package/pkg-kconfig.mk
> @@ -35,18 +35,20 @@ $(call inner-generic-package,$(1),$(2),$(3),$(4))
>  $(2)_KCONFIG_EDITORS ?= menuconfig
>  $(2)_KCONFIG_OPTS ?=
>  $(2)_KCONFIG_FIXUP_CMDS ?=
> +$(2)_KCONFIG_FRAGMENT_FILES ?=
>  
>  # The config file could be in-tree, so before depending on it the package should
>  # be extracted (and patched) first
>  $$($(2)_KCONFIG_FILE): | $(1)-patch
>  
> -# The .config file is obtained by copying it from the specified source
> -# configuration file, after the package has been patched.
> +# The specified source configuration file and any additional configuration file
> +# fragments are merged together to .config, after the package has been patched.
>  # Since the file could be a defconfig file it needs to be expanded to a
>  # full .config first. We use 'make oldconfig' because this can be safely
>  # done even when the package does not support defconfigs.
> -$$($(2)_DIR)/.config: $$($(2)_KCONFIG_FILE)
> -	$$(INSTALL) -m 0644 $$($(2)_KCONFIG_FILE) $$($(2)_DIR)/.config
> +$$($(2)_DIR)/.config: $$($(2)_KCONFIG_FILE) $$($(2)_KCONFIG_FRAGMENT_FILES)
> +	support/kconfig/merge_config.sh -m -O $$(@D) \
> +		$$($(2)_KCONFIG_FILE) $$($(2)_KCONFIG_FRAGMENT_FILES)
>  	@yes "" | $$($(2)_MAKE_ENV) $$(MAKE) -C $$($(2)_DIR) \
>  		$$($(2)_KCONFIG_OPTS) oldconfig
>  
> @@ -87,6 +89,8 @@ $(1)-savedefconfig: $$($(2)_DIR)/.stamp_kconfig_fixup_done
>  # Even though we could use 'cp --preserve-timestamps' here, the separate
>  # cp and 'touch --reference' is used for symmetry with $(1)-update-defconfig.
>  $(1)-update-config: $$($(2)_DIR)/.stamp_kconfig_fixup_done
> +	$$(if $$($(2)_KCONFIG_FRAGMENT_FILES), \
> +		echo "Unable to perform $(1)-update-config when fragment files are set"; exit 1)

 There should be an @ in front of this, otherwise you see the error twice.

>  	cp -f $$($(2)_DIR)/.config $$($(2)_KCONFIG_FILE)
>  	touch --reference $$($(2)_DIR)/.config $$($(2)_KCONFIG_FILE)
>  
> @@ -95,6 +99,8 @@ $(1)-update-config: $$($(2)_DIR)/.stamp_kconfig_fixup_done
>  # $(1)-update-config, the reference for 'touch' is _not_ the file from which
>  # we copy.
>  $(1)-update-defconfig: $(1)-savedefconfig
> +	$$(if $$($(2)_KCONFIG_FRAGMENT_FILES), \
> +		echo "Unable to perform $(1)-update-defconfig when fragment files are set"; exit 1)

 And here.


 Regards,
 Arnout

>  	cp -f $$($(2)_DIR)/defconfig $$($(2)_KCONFIG_FILE)
>  	touch --reference $$($(2)_DIR)/.config $$($(2)_KCONFIG_FILE)
>  
> 


-- 
Arnout Vandecappelle                          arnout at mind be
Senior Embedded Software Architect            +32-16-286500
Essensium/Mind                                http://www.mind.be
G.Geenslaan 9, 3001 Leuven, Belgium           BE 872 984 063 RPR Leuven
LinkedIn profile: http://www.linkedin.com/in/arnoutvandecappelle
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