#!/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.

proc clean_up {
	rm -f $TMP_FILE
	exit
}
trap clean_up HUP INT TERM

proc usage {
	echo "Usage: $0 [OPTIONS] [CONFIG [...]]"
	echo "  -h    display this help text"
	echo "  -m    only merge the fragments, do not execute the make command"
	echo "  -n    use allnoconfig instead of alldefconfig"
	echo "  -r    list redundant entries when merging fragments"
	echo "  -O    dir to put generated output files.  Consider setting \$KCONFIG_CONFIG instead."
}

setglobal RUNMAKE = 'true'
setglobal ALLTARGET = 'alldefconfig'
setglobal WARNREDUN = 'false'
setglobal OUTPUT = '.'

while true {
	match $1 {
	with "-n"
		setglobal ALLTARGET = 'allnoconfig'
		shift
		continue
		
	with "-m"
		setglobal RUNMAKE = 'false'
		shift
		continue
		
	with "-h"
		usage
		exit
		
	with "-r"
		setglobal WARNREDUN = 'true'
		shift
		continue
		
	with "-O"
		if test -d $2{
			setglobal OUTPUT = $[echo $2 | sed 's/\/*$//]
		} else {
			echo "output directory $2 does not exist" !1 > !2
			exit 1
		}
		shift 2
		continue
		
	with *
		break
		
	}
}

if test "$Argc" -lt 1  {
	usage
	exit
}

if test -z $KCONFIG_CONFIG {
	if test $OUTPUT != . {
		setglobal KCONFIG_CONFIG = $[readlink -m -- "$OUTPUT/.config]
	} else {
		setglobal KCONFIG_CONFIG = '.config'
	}
}

setglobal INITFILE = $1
shift;

if test ! -r $INITFILE {
	echo "The base file '$INITFILE' does not exist.  Exit." > !2
	exit 1
}

setglobal MERGE_LIST = $ifsjoin(Argv)
setglobal SED_CONFIG_EXP = '"s/^\(# \)\{0,1\}\(CONFIG_[a-zA-Z0-9_]*\)[= ].*/\2/p'"
setglobal TMP_FILE = $[mktemp ./.tmp.config.XXXXXXXXXX]

echo "Using $INITFILE as base"
cat $INITFILE > $TMP_FILE

# Merge files, printing warnings on overridden values
for MERGE_FILE in [$MERGE_LIST]  {
	echo "Merging $MERGE_FILE"
	if test ! -r $MERGE_FILE {
		echo "The merge file '$MERGE_FILE' does not exist.  Exit." > !2
		exit 1
	}
	setglobal CFG_LIST = $[sed -n $SED_CONFIG_EXP $MERGE_FILE]

	for CFG in [$CFG_LIST]  {
		grep -q -w $CFG $TMP_FILE || continue
		setglobal PREV_VAL = $[grep -w $CFG $TMP_FILE]
		setglobal NEW_VAL = $[grep -w $CFG $MERGE_FILE]
		if test "x$PREV_VAL" != "x$NEW_VAL"  {
			echo Value of $CFG is redefined by fragment $MERGE_FILE:
			echo Previous  value: $PREV_VAL
			echo New value:       $NEW_VAL
			echo
		} elif test $WARNREDUN = "true" {
			echo Value of $CFG is redundant by fragment $MERGE_FILE:
		}
		sed -i "/$CFG[ =]/d" $TMP_FILE
	}
	cat $MERGE_FILE >> $TMP_FILE
}

if test $RUNMAKE = "false" {
	cp -T -- $TMP_FILE $KCONFIG_CONFIG
	echo "#"
	echo "# merged configuration written to $KCONFIG_CONFIG (needs make)"
	echo "#"
	clean_up
	exit
}

# If we have an output dir, setup the O= argument, otherwise leave
# it blank, since O=. will create an unnecessary ./source softlink
setglobal OUTPUT_ARG = ''""
if test $OUTPUT != "."  {
	setglobal OUTPUT_ARG = ""O=$OUTPUT""
}


# Use the merged file as the starting point for:
# alldefconfig: Fills in any missing symbols with Kconfig default
# allnoconfig: Fills in any missing symbols with # CONFIG_* is not set
make KCONFIG_ALLCONFIG=$TMP_FILE $OUTPUT_ARG $ALLTARGET


# Check all specified config values took (might have missed-dependency issues)
for CFG in [$[sed -n $SED_CONFIG_EXP $TMP_FILE]] {

	setglobal REQUESTED_VAL = $[grep -w -e $CFG $TMP_FILE]
	setglobal ACTUAL_VAL = $[grep -w -e $CFG $KCONFIG_CONFIG]
	if test "x$REQUESTED_VAL" != "x$ACTUAL_VAL"  {
		echo "Value requested for $CFG not in final .config"
		echo "Requested value:  $REQUESTED_VAL"
		echo "Actual value:     $ACTUAL_VAL"
		echo ""
	}
}

clean_up