Documentation/features: Add script that refreshes the arch support status files in place

#

# Small script that refreshes the kernel feature support status in place.

#

for F_FILE in Documentation/features/*/*/arch-support.txt; do

	F=$(grep "^#         Kconfig:" "$F_FILE" | cut -c26-)

	#

	# Each feature F is identified by a pair (O, K), where 'O' can

	# be either the empty string (for 'nop') or "not" (the logical

	# negation operator '!'); other operators are not supported.

	#

	O=""

	K=$F

	if [[ "$F" == !* ]]; then

		O="not"

		K=$(echo $F | sed -e 's/^!//g')

	fi

	#

	# F := (O, K) is 'valid' iff there is a Kconfig file (for some

	# arch) which contains K.

	#

	# Notice that this definition entails an 'asymmetry' between

	# the case 'O = ""' and the case 'O = "not"'. E.g., F may be

	# _invalid_ if:

	#

	# [case 'O = ""']

	#   1) no arch provides support for F,

	#   2) K does not exist (e.g., it was renamed/mis-typed);

	#

	# [case 'O = "not"']

	#   3) all archs provide support for F,

	#   4) as in (2).

	#

	# The rationale for adopting this definition (and, thus, for

	# keeping the asymmetry) is:

	#

	#       We want to be able to 'detect' (2) (or (4)).

	#

	# (1) and (3) may further warn the developers about the fact

	# that K can be removed.

	#

	F_VALID="false"

	for ARCH_DIR in arch/*/; do

		K_FILES=$(find $ARCH_DIR -name "Kconfig*")

		K_GREP=$(grep "$K" $K_FILES)

		if [ ! -z "$K_GREP" ]; then

			F_VALID="true"

			break

		fi

	done

	if [ "$F_VALID" = "false" ]; then

		printf "WARNING: '%s' is not a valid Kconfig\n" "$F"

	fi

	T_FILE="$F_FILE.tmp"

	grep "^#" $F_FILE > $T_FILE

	echo "    -----------------------" >> $T_FILE

	echo "    |         arch |status|" >> $T_FILE

	echo "    -----------------------" >> $T_FILE

	for ARCH_DIR in arch/*/; do

		ARCH=$(echo $ARCH_DIR | sed -e 's/arch//g' | sed -e 's/\///g')

		K_FILES=$(find $ARCH_DIR -name "Kconfig*")

		K_GREP=$(grep "$K" $K_FILES)

		#

		# Arch support status values for (O, K) are updated according

		# to the following rules.

		#

		#   - ("", K) is 'supported by a given arch', if there is a

		#     Kconfig file for that arch which contains K;

		#

		#   - ("not", K) is 'supported by a given arch', if there is

		#     no Kconfig file for that arch which contains K;

		#

		#   - otherwise: preserve the previous status value (if any),

		#                default to 'not yet supported'.

		#

		# Notice that, according these rules, invalid features may be

		# updated/modified.

		#

		if [ "$O" = "" ] && [ ! -z "$K_GREP" ]; then

			printf "    |%12s: |  ok  |\n" "$ARCH" >> $T_FILE

		elif [ "$O" = "not" ] && [ -z "$K_GREP" ]; then

			printf "    |%12s: |  ok  |\n" "$ARCH" >> $T_FILE

		else

			S=$(grep -v "^#" "$F_FILE" | grep " $ARCH:")

			if [ ! -z "$S" ]; then

				echo "$S" >> $T_FILE

			else

				printf "    |%12s: | TODO |\n" "$ARCH" \

					>> $T_FILE

			fi

		fi

	done

	echo "    -----------------------" >> $T_FILE

	mv $T_FILE $F_FILE

done