[Buildroot] [PATCH v2 0/2] core/pkg-kconfig: Fix .config generation

[Buildroot] [PATCH v2 0/2] core/pkg-kconfig: Fix .config generation

[Romain Izard]

To use an existing file as .config for a project, it needs to be
validated with 'make oldconfig'. If the file does not match all the
configuration entries of the project, the user will be prompted to
select the values for the new entries.

Historically, 'yes "" | make oldconfig' was used to silently select the
default values for new entries. But this does not work well with the
Linux kernel, as it will not select the correct option when configuring
tristate choice entries.

The Linux kernel has added a 'oldnoconfig' target, since renamed
'olddefconfig', that will work correctly, but this target does not exist
in all projects that rely on the kconfig workflow.

Update buildroot to use 'oldnoconfig' when available, and fallback to
the default method otherwise.

Romain Izard (2):
  core/pkg-kconfig: fix .config rule for silent mode
  core/pkg-kconfig: Use oldnoconfig when possible

 package/pkg-kconfig.mk | 26 ++++++++++++++++++--------
 1 file changed, 18 insertions(+), 8 deletions(-)

-- 
2.5.0

[Buildroot] [PATCH v2 1/2] core/pkg-kconfig: fix .config rule for silent mode

[Romain Izard]

Ensure that each command line in the .config rule is prefixed by $$(Q)

Signed-off-by: Romain Izard <romain.izard.pro@gmail.com>
---
Changelog:
v2: New patch

 package/pkg-kconfig.mk | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/package/pkg-kconfig.mk b/package/pkg-kconfig.mk
index 90f3f9f..94ec3cc 100644
--- a/package/pkg-kconfig.mk
+++ b/package/pkg-kconfig.mk
@@ -63,11 +63,11 @@ $$($(2)_KCONFIG_FILE) $$($(2)_KCONFIG_FRAGMENT_FILES): | $(1)-patch
 # 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) $$($(2)_KCONFIG_FRAGMENT_FILES)
-	$$(if $$($(2)_KCONFIG_DEFCONFIG), \
+	$$(Q)$$(if $$($(2)_KCONFIG_DEFCONFIG), \
 		$$($(2)_MAKE_ENV) $$(MAKE) -C $$($(2)_DIR) \
 			$$($(2)_KCONFIG_OPTS) $$($(2)_KCONFIG_DEFCONFIG), \
 		cp $$($(2)_KCONFIG_FILE) $$(@))
-	support/kconfig/merge_config.sh -m -O $$(@D) \
+	$$(Q)support/kconfig/merge_config.sh -m -O $$(@D) \
 		$$(@) $$($(2)_KCONFIG_FRAGMENT_FILES)
 	$$(Q)yes "" | $$($(2)_MAKE_ENV) $$(MAKE) -C $$($(2)_DIR) \
 		$$($(2)_KCONFIG_OPTS) oldconfig
-- 
2.5.0

[Buildroot] [PATCH v2 2/2] core/pkg-kconfig: Use oldnoconfig when possible

[Romain Izard]

Using 'yes "" | make oldconfig' to regenerate a .config file from an
existing defconfig does not work reliably in all cases. Specifically, it
does not work well with tristate choice entries.

The correct way to do it is to use 'make olddefconfig', but this target
is not supported in projects that use an old version of kconfig. As
most projects do not use tristate entries, there is no need for them to
upgrade.

'oldnoconfig' is an alias for 'olddefconfig', but it also is the only
name for this target between Linux versions 2.6.36 and 3.6.

Try to use 'oldnoconfig' by default, using 'oldconfig' as a fallback

Signed-off-by: Romain Izard <romain.izard.pro@gmail.com>
---
Changelog:
v1: new patch
v2: Use oldnoconfig instead of olddefconfig
    Fix silent mode
    Change the pattern in both places where it is used
    Use a macro to avoid redundancy

 package/pkg-kconfig.mk | 22 ++++++++++++++++------
 1 file changed, 16 insertions(+), 6 deletions(-)

diff --git a/package/pkg-kconfig.mk b/package/pkg-kconfig.mk
index 94ec3cc..08c3e9f 100644
--- a/package/pkg-kconfig.mk
+++ b/package/pkg-kconfig.mk
@@ -57,11 +57,23 @@ $$($(2)_KCONFIG_FILE) $$($(2)_KCONFIG_FRAGMENT_FILES): | $(1)-patch
 		fi; \
 	done
 
+# The correct way to regenerate a .config file is to use 'make olddefconfig'.
+# For historical reasons, the target name is 'oldnoconfig' between Linux kernel
+# versions 2.6.36 and 3.6, and remains as an alias in later versions.
+# In older versions, and in some other projects that use kconfig, the target is
+# not supported at all, and we use 'yes "" | make oldconfig' as a fallback
+# only, as this can fail in complex cases.
+define $(2)_REGEN_DOT_CONFIG
+	$$(Q)$$($2_MAKE_ENV) $$(MAKE) -C $$($(2)_DIR) \
+		$$($(2)_KCONFIG_OPTS) oldnoconfig || \
+		(yes "" | $$($(2)_MAKE_ENV) $$(MAKE) -C $$($(2)_DIR) \
+			$$($(2)_KCONFIG_OPTS) oldconfig)
+endef
+
 # The specified source configuration file and any additional configuration file
 # fragments are merged together to .config, after the package has been patched.
 # Since the file could be a defconfig file it needs to be expanded to a
-# full .config first. We use 'make oldconfig' because this can be safely
-# done even when the package does not support defconfigs.
+# full .config first.
 $$($(2)_DIR)/.config: $$($(2)_KCONFIG_FILE) $$($(2)_KCONFIG_FRAGMENT_FILES)
 	$$(Q)$$(if $$($(2)_KCONFIG_DEFCONFIG), \
 		$$($(2)_MAKE_ENV) $$(MAKE) -C $$($(2)_DIR) \
@@ -69,8 +81,7 @@ $$($(2)_DIR)/.config: $$($(2)_KCONFIG_FILE) $$($(2)_KCONFIG_FRAGMENT_FILES)
 		cp $$($(2)_KCONFIG_FILE) $$(@))
 	$$(Q)support/kconfig/merge_config.sh -m -O $$(@D) \
 		$$(@) $$($(2)_KCONFIG_FRAGMENT_FILES)
-	$$(Q)yes "" | $$($(2)_MAKE_ENV) $$(MAKE) -C $$($(2)_DIR) \
-		$$($(2)_KCONFIG_OPTS) oldconfig
+	$$(call $(2)_REGEN_DOT_CONFIG)
 
 # If _KCONFIG_FILE or _KCONFIG_FRAGMENT_FILES exists, this dependency is
 # already implied, but if we only have a _KCONFIG_DEFCONFIG we have to add
@@ -81,8 +92,7 @@ $$($(2)_DIR)/.config: | $(1)-patch
 # The exact rules are specified by the package .mk file.
 define $(2)_FIXUP_DOT_CONFIG
 	$$($(2)_KCONFIG_FIXUP_CMDS)
-	$$(Q)yes "" | $$($(2)_MAKE_ENV) $$(MAKE) -C $$($(2)_DIR) \
-		$$($(2)_KCONFIG_OPTS) oldconfig
+	$$(call $(2)_REGEN_DOT_CONFIG)
 	$$(Q)touch $$($(2)_DIR)/.stamp_kconfig_fixup_done
 endef
 
-- 
2.5.0

[Buildroot] [PATCH v2 1/2] core/pkg-kconfig: fix .config rule for silent mode

[Thomas Petazzoni]

Hello,

On Tue, 29 Mar 2016 12:11:41 +0200, Romain Izard wrote:
> Ensure that each command line in the .config rule is prefixed by $$(Q)
> 
> Signed-off-by: Romain Izard <romain.izard.pro@gmail.com>
> ---
> Changelog:
> v2: New patch

Applied to master, thanks.

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

[Buildroot] [PATCH v2 2/2] core/pkg-kconfig: Use oldnoconfig when possible

[Arnout Vandecappelle]

On 03/29/16 12:11, Romain Izard wrote:
> Using 'yes "" | make oldconfig' to regenerate a .config file from an
> existing defconfig does not work reliably in all cases. Specifically, it
> does not work well with tristate choice entries.
>
> The correct way to do it is to use 'make olddefconfig', but this target
> is not supported in projects that use an old version of kconfig. As
> most projects do not use tristate entries, there is no need for them to
> upgrade.
>
> 'oldnoconfig' is an alias for 'olddefconfig', but it also is the only
> name for this target between Linux versions 2.6.36 and 3.6.
>
> Try to use 'oldnoconfig' by default, using 'oldconfig' as a fallback
>
> Signed-off-by: Romain Izard <romain.izard.pro@gmail.com>
> ---
> Changelog:
> v1: new patch
> v2: Use oldnoconfig instead of olddefconfig
>      Fix silent mode
>      Change the pattern in both places where it is used
>      Use a macro to avoid redundancy
>
>   package/pkg-kconfig.mk | 22 ++++++++++++++++------
>   1 file changed, 16 insertions(+), 6 deletions(-)
>
> diff --git a/package/pkg-kconfig.mk b/package/pkg-kconfig.mk
> index 94ec3cc..08c3e9f 100644
> --- a/package/pkg-kconfig.mk
> +++ b/package/pkg-kconfig.mk
> @@ -57,11 +57,23 @@ $$($(2)_KCONFIG_FILE) $$($(2)_KCONFIG_FRAGMENT_FILES): | $(1)-patch
>   		fi; \
>   	done
>
> +# The correct way to regenerate a .config file is to use 'make olddefconfig'.
> +# For historical reasons, the target name is 'oldnoconfig' between Linux kernel
> +# versions 2.6.36 and 3.6, and remains as an alias in later versions.
> +# In older versions, and in some other projects that use kconfig, the target is
> +# not supported at all, and we use 'yes "" | make oldconfig' as a fallback
> +# only, as this can fail in complex cases.
> +define $(2)_REGEN_DOT_CONFIG
> +	$$(Q)$$($2_MAKE_ENV) $$(MAKE) -C $$($(2)_DIR) \
> +		$$($(2)_KCONFIG_OPTS) oldnoconfig || \

  $$($2_MAKE_ENV) $$(MAKE) -C $$($(2)_DIR) $$($(2)_KCONFIG_OPTS) is used so 
often that it would be worth putting it in a separate variable. But that's a 
separate patch.

> +		(yes "" | $$($(2)_MAKE_ENV) $$(MAKE) -C $$($(2)_DIR) \
> +			$$($(2)_KCONFIG_OPTS) oldconfig)
> +endef
> +
>   # 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.
> +# full .config first.
>   $$($(2)_DIR)/.config: $$($(2)_KCONFIG_FILE) $$($(2)_KCONFIG_FRAGMENT_FILES)
>   	$$(Q)$$(if $$($(2)_KCONFIG_DEFCONFIG), \
>   		$$($(2)_MAKE_ENV) $$(MAKE) -C $$($(2)_DIR) \
> @@ -69,8 +81,7 @@ $$($(2)_DIR)/.config: $$($(2)_KCONFIG_FILE) $$($(2)_KCONFIG_FRAGMENT_FILES)
>   		cp $$($(2)_KCONFIG_FILE) $$(@))
>   	$$(Q)support/kconfig/merge_config.sh -m -O $$(@D) \
>   		$$(@) $$($(2)_KCONFIG_FRAGMENT_FILES)
> -	$$(Q)yes "" | $$($(2)_MAKE_ENV) $$(MAKE) -C $$($(2)_DIR) \
> -		$$($(2)_KCONFIG_OPTS) oldconfig
> +	$$(call $(2)_REGEN_DOT_CONFIG)

  call is not needed here because there are no arguments. Just use 
$$($(2)_REGEN_DOT_CONFIG).

  Otherwise looks good to me, so after removing the call (below as well) you can 
add my Reviewed-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>

  Regards,
  Arnout

>
>   # If _KCONFIG_FILE or _KCONFIG_FRAGMENT_FILES exists, this dependency is
>   # already implied, but if we only have a _KCONFIG_DEFCONFIG we have to add
> @@ -81,8 +92,7 @@ $$($(2)_DIR)/.config: | $(1)-patch
>   # The exact rules are specified by the package .mk file.
>   define $(2)_FIXUP_DOT_CONFIG
>   	$$($(2)_KCONFIG_FIXUP_CMDS)
> -	$$(Q)yes "" | $$($(2)_MAKE_ENV) $$(MAKE) -C $$($(2)_DIR) \
> -		$$($(2)_KCONFIG_OPTS) oldconfig
> +	$$(call $(2)_REGEN_DOT_CONFIG)
>   	$$(Q)touch $$($(2)_DIR)/.stamp_kconfig_fixup_done
>   endef
>
>


-- 
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
GPG fingerprint:  7493 020B C7E3 8618 8DEC 222C 82EB F404 F9AC 0DDF