Re: [PATCH] kconfig: Add merge_config.sh script

[Michal Marek <mmarek@suse.cz>]

On 21.9.2011 07:22, John Stultz wrote:
> After noticing almost every distro has their own method of managing
> config fragments, I went looking at some best practices, and wanted
> to try to consolidate some of the different approaches so this fairly
> simple infrastructure can be shared (and new distros/build systems
> don't have to implement yet another config fragment merge script).
> 
> This script is most influenced by the Windriver tools used in
> the Yocto Project, reusing some portions found there.
> 
> This script merges multiple config fragments, warning on any
> overrided values. It then sets any unspecified values to their
> default, then finally checks to make sure no specified value was
> dropped due to unsatisfied dependencies.
> 
> I'm sure I'm sure this implementation won't work for everyone, and
> I expect it will need to evolve to adapt for various use cases.
> But I think its a reasonable starting point.
> 
> v2: Reworked to use alldefconfig instead of the proposed
> olddefconfig as suggested by Sam Ravnborg.
> 
> Thanks to Darren Hart for early review and feedback!
> 
> Please let me know if you have any comments or thoughts!
> 
> CC: Sam Ravnborg <sam@ravnborg.org>
> CC: gthelen@google.com
> CC: tartler@cs.fau.de
> CC: Dmitry Fink <Dmitry.Fink@palm.com>
> CC: Darren Hart <dvhart@linux.intel.com>
> CC: Eric B Munson <ebmunson@us.ibm.com>
> CC: Bruce Ashfield <Bruce.Ashfield@windriver.com>
> CC: Michal Marek <mmarek@suse.cz>
> CC: linux-kbuild@vger.kernel.org
> Signed-off-by: John Stultz <john.stultz@linaro.org>
> ---
>  scripts/kconfig/merge_config.sh |   71 +++++++++++++++++++++++++++++++++++++++
>  1 files changed, 71 insertions(+), 0 deletions(-)
>  create mode 100755 scripts/kconfig/merge_config.sh
> 
> diff --git a/scripts/kconfig/merge_config.sh b/scripts/kconfig/merge_config.sh
> new file mode 100755
> index 0000000..fda0139
> --- /dev/null
> +++ b/scripts/kconfig/merge_config.sh
> @@ -0,0 +1,71 @@
> +#!/bin/sh
> +#  merge_config.sh - Takes a list of config fragment values, and merges
> +#  them one by one. Provides warnings on overridden values, and specified
> +#  values that did not make it to the resulting .config file (due to missed
> +#  dependencies or config symbol removal).
> +#
> +#  Portions reused from kconf_check and generate_cfg:
> +#  http://git.yoctoproject.org/cgit/cgit.cgi/yocto-kernel-tools/tree/tools/kconf_check
> +#  http://git.yoctoproject.org/cgit/cgit.cgi/yocto-kernel-tools/tree/tools/generate_cfg
> +#
> +#  Copyright (c) 2009-2010 Wind River Systems, Inc.
> +#  Copyright 2011 Linaro
> +#
> +#  This program is free software; you can redistribute it and/or modify
> +#  it under the terms of the GNU General Public License version 2 as
> +#  published by the Free Software Foundation.
> +#
> +#  This program is distributed in the hope that it will be useful,
> +#  but WITHOUT ANY WARRANTY; without even the implied warranty of
> +#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
> +#  See the GNU General Public License for more details.
> +
> +MERGE_LIST=$*
> +
> +
> +TMP_FILE=$(mktemp ./.tmp.config.XXXXXXXXXX)
> +
> +# Merge files, printing warnings on overrided values
> +for MERGE_FILE in $MERGE_LIST ; do
> +	echo "Merging $MERGE_FILE"
> +	CFG_LIST=`cat $MERGE_FILE | \
> +	  sed 's/^\(# \)\{0,1\}\(CONFIG_[a-zA-Z0-9_]*\)[= ].*/\2/'`
> +	for CFG in $CFG_LIST ; do
> +		grep -q -w $CFG $TMP_FILE
> +		if [ $? == 0 ] ; then
> +			PREV_VAL=`grep -w $CFG $TMP_FILE`
> +			NEW_VAL=`grep -w $CFG $MERGE_FILE`
> +			if [ "x$PREV_VAL" != "x$NEW_VAL" ] ; then
> +			echo Value of $CFG is redefined by fragment $MERGE_FILE:
> +			echo Previous  value: `grep -w $CFG $TMP_FILE`
> +			echo New value:       `grep -w $CFG $MERGE_FILE`

kconfig already warns when a symbol appears multiple times in .config.
If really wanted, a verbose mode that show the  previous and new value
could be added as well.


> +			echo
> +			fi
> +			sed -i "/$CFG[ =]/d" $TMP_FILE
> +		fi
> +	done
> +	cat $MERGE_FILE >> $TMP_FILE
> +done
> +
> +
> +# Use the merged file as the starting point for alldefconfig
> +# (Fills in any missing symbols with Kconfig default)
> +make KCONFIG_ALLCONFIG=$TMP_FILE alldefconfig
> +
> +# Check all specified config values took (might have missed-dependency issues)
> +cat $TMP_FILE | while read line; do
> +	CFG=`echo $line | \
> +		sed 's/^\(# \)\{0,1\}\(CONFIG_[a-zA-Z0-9_]*\)[= ].*/\2/'`
> +
> +	REQUESTED_VAL=`grep -w -e "$CFG" $TMP_FILE`
> +	ACTUAL_VAL=`grep -w -e "$CFG" .config`
> +	if [ "x$REQUESTED_VAL" != "x$ACTUAL_VAL" ] ; then
> +		echo "Value requested for $CFG not in final .config"
> +		echo "Requested value:  $REQUESTED_VAL"
> +		echo "Actual value:     $ACTUAL_VAL"
> +		echo ""

This requested vs. actual diff would be nice to have in kconfig I think.
The the merge script could be reduced to a simple cat(1) invocation.

Michal