kconfig: add merge_config.sh script

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 overridden
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 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.

Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Greg Thelen <gthelen@google.com>
Cc: Reinhard Tartler <Reinhard.Tartler@informatik.uni-erlangen.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>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Michal Marek <mmarek@suse.cz>
merge_config.sh: use signal names compatible with dash and bash

The SIGHUP SIGINT and SIGTERM names caused failures when running
merge_config.sh with the dash shell.  Dropping the "SIG" component makes
the script work in both bash and dash.

Signed-off-by: Darren Hart <dvhart@linux.intel.com>
Acked-by: John Stultz <john.stultz@linaro.org>
Cc: Michal Marek <mmarek@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Michal Marek <mmarek@suse.cz>
merge_config.sh: whitespace cleanup

Fix whitespace usage in the clean_up routine.

Signed-off-by: Darren Hart <dvhart@linux.intel.com>
Acked-by: John Stultz <john.stultz@linaro.org>
Cc: Michal Marek <mmarek@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Michal Marek <mmarek@suse.cz>
merge_config.sh: fix bug in final check

Arnaud Lacombe pointed out the final checking that the requested configs
were included in the final .config was broken.

The example was that if you had a fragment that disabled
CONFIG_DECOMPRESS_GZIP applied to a normal defconfig, there would be no
final warning that CONFIG_DECOMPRESS_GZIP was acutally set in the final
.config.

This bug was introduced by me in v3 of the original patch, and the
following patch reverts the invalid change.

Signed-off-by: John Stultz <john.stultz@linaro.org>
Reported-by: Arnaud Lacombe <lacombar@gmail.com>
Cc: Darren Hart <dvhart@linux.intel.com>
Cc: Michal Marek <mmarek@suse.cz>
Cc: Arnaud Lacombe <lacombar@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Michal Marek <mmarek@suse.cz>
merge_config.sh: Use the first file as the initial config

Take the first config fragment and use it verbatim as the initial config
set.  This avoids running the verification loop for the first file, as
nothing has actually been merged at this point.  This significantly
increases performance for large config fragments.

Signed-off-by: Josh Boyer <jwboyer@redhat.com>
Acked-by: John Stultz <john.stultz@linaro.org>
Acked-by: Darren Hart <dvhart@linux.intel.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>
merge_config.sh: Set execute bit

Somehow the merge_config.sh script didn't get its execute bit
set when it was merged. Fix this.

Signed-off-by: John Stultz <john.stultz@linaro.org>
Acked-by: Darren Hart <dvhart@linux.intel.com>
Acked-by: Bruce Ashfield <bruce.ashfield@windriver.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>
merge_config.sh: Add option to display redundant configs

Provide a -r option to display when fragments contain redundant
options. This is really useful when breaking apart a config into
fragments, as well as cleaning up older fragments.

Signed-off-by: John Stultz <john.stultz@linaro.org>
Acked-by: Darren Hart <dvhart@linux.intel.com>
Acked-by: Bruce Ashfield <bruce.ashfield@windriver.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>
merge_config.sh: Add option to specify output dir

Provide a -O option to specify dir to put generated .config
Then merge_config.sh does not need to be copied to target dir,
for easy re-usage in other script

Signed-off-by: Zhangfei Gao <zhangfei.gao@linaro.org>
Tested-by: Jon Medhurst (Tixy) <tixy@linaro.org>
Acked-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Michal Marek <mmarek@suse.cz>
merge_config.sh: Avoid creating unnessary source softlinks

Viresh noticed when using merge_config.sh that a source softlink
was being created even when he didn't specify the -O option.

The problem arises due to the previous commit 409f117e2d6b
which added the -O option. Basically if -O is not specified,
we still pass '-O=.' to the make command, which then generates
a source softlink to ./

This patch adds an extra check so if there is no -O specified
to merge_config.sh, we don't pass one on to make.

Cc: Zhangfei Gao <zhangfei.gao@linaro.org>
Cc: Bruce Ashfield <bruce.ashfield@windriver.com>
Acked-by: Darren Hart <dvhart@linux.intel.com>
Reported-and-tested-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Michal Marek <mmarek@suse.cz>
ANDROID: ARM: tegra: paz00: Update android defconfig

* Clean hacking options

Signed-off-by: zombah <zombah@gmail.com>