#!/bin/bash

# The Qubes OS Project, https://www.qubes-os.org
#
# Copyright (C) 2017 Simon Gaiser <simon@invisiblethingslab.com>
# 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.

set -eu -o pipefail

linux_merge_config="./scripts/kconfig/merge_config.sh"
make_opts=""

if [ -n "${LINUX_UPSTREAM_VERSION:-}" ]; then
    linux_merge_config="../linux-$LINUX_UPSTREAM_VERSION/scripts/kconfig/merge_config.sh"
    make_opts="-C ../linux-$LINUX_UPSTREAM_VERSION O=$PWD"
fi

if [ -z "$linux_merge_config" ]; then
    printf 'Error: Could not find merge_config.sh from the linux source tree!\n'
    exit 1
fi

sed_config_exp='s/^\(# \)\{0,1\}\(CONFIG_[a-zA-Z0-9_]*\)[= ].*/\2/p'

if [ $# -ne 2 ]; then
    printf 'Usage: gen-config base.config local.config\n'
    exit 1
fi

base_config="$1"
local_config="$2"

grep -v '^##' "$local_config" > "$local_config.gen" || [ $? -le 1 ]

$linux_merge_config -m "$base_config" "$local_config.gen"

make $make_opts KCONFIG_ALLCONFIG=.config alldefconfig

rc=0
for cfg in $(sed -n "$sed_config_exp" "$local_config.gen"); do
    requested="$(grep -w "$cfg" "$local_config.gen" || true)"
    actual="$(grep -w "$cfg" .config || true)"
    if [ "$requested" != "$actual" ]; then
        printf 'Local config setting for %s didn'\''t make it into the final config\n' "$cfg"
        rc=1
    fi
done

rm "$local_config.gen"

exit $rc