kbuild: script to check for undefined Kconfig symbols

#!/bin/sh

# Find Kconfig variables used in source code but never defined in Kconfig

# Copyright (C) 2007, Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>

# Tested with dash.

paths="$@"

[ -z "$paths" ] && paths=.

# Doing this once at the beginning saves a lot of time, on a cache-hot tree.

Kconfigs="`find . -name 'Kconfig' -o -name 'Kconfig*[^~]'`"

echo -e "File list \tundefined symbol used"

find $paths -name '*.[chS]' -o -name 'Makefile' -o -name 'Makefile*[^~]'| while read i

do

	# Output the bare Kconfig variable and the filename; the _MODULE part at

	# the end is not removed here (would need perl an not-hungry regexp for that).

	sed -ne 's!^.*\<\(UML_\)\?CONFIG_\([0-9A-Z_]\+\).*!\2 '$i'!p' < $i

done | \

# Smart "sort|uniq" implemented in awk and tuned to collect the names of all

# files which use a given symbol

awk '{map[$1, count[$1]++] = $2; }

END {

	for (combIdx in map) {

		split(combIdx, separate, SUBSEP);

		# The value may have been removed.

		if (! ( (separate[1], separate[2]) in map ) )

			continue;

		symb=separate[1];

		printf "%s ", symb;

		#Use gawk extension to delete the names vector

		delete names;

		#Portably delete the names vector

		#split("", names);

		for (i=0; i < count[symb]; i++) {

			names[map[symb, i]] = 1;

			# Unfortunately, we may still encounter symb, i in the

			# outside iteration.

			delete map[symb, i];

		}

		i=0;

		for (name in names) {

			if (i > 0)

				printf ", %s", name;

			else

				printf "%s", name;

			i++;

		}

		printf "\n";

	}

}' |

while read symb files; do

	# Remove the _MODULE suffix when checking the variable name. This should

	# be done only on tristate symbols, actually, but Kconfig parsing is

	# beyond the purpose of this script.

	symb_bare=`echo $symb | sed -e 's/_MODULE//'`

	if ! grep -q "\<$symb_bare\>" $Kconfigs; then

		echo -e "$files: \t$symb"

	fi

done|sort