build.config: Add fragment config awareness

Present fragment config logic is target specific and located in the
scripts/gki folder. The script does not scale well to different targets
which may have different types of variants. Migrate fragment config logic
to build.config files, where the variant stitching can be described in the
relevant build.config.msm.target file. The fragment stitching logic must
also be in kernel/build system in order to respect any Make invocation
arguments (e.g. compiler).

Change-Id: I77454c2b431b3f5c0ce75a17714b43913c03ced4
Signed-off-by: Elliot Berman <eberman@codeaurora.org>

build.config.msm.common

@@ -40,11 +40,86 @@ if [ ! -z $VARIANT ]; then
 fi
 
 ################################################################################
-## menuconfig
+## defconfigs
+
+# Helper function to let build.config files merge config fragments
+# Usage: append_cmd PRE_DEFCONFIG_CMDS 'merge_defconfig_fragment ${DEFCONFIG} ${fragment_config}'
+DEFCONFIG_FRAGMENTS=""
+function merge_defconfig_fragments() {
+	if ( [ -z "${DEFCONFIG_FRAGMENTS}" ] ||
+	   [ "${DEFCONFIG_FRAGMENTS}" = "${DEFCONFIG}" ] ); then
+		echo "No defconfig fragments for ${DEFCONFIG}"
+		return
+	fi
+	KCONFIG_CONFIG=${KERNEL_DIR}/arch/${ARCH}/configs/${DEFCONFIG} \
+		${KERNEL_DIR}/scripts/kconfig/merge_config.sh \
+		-m -r ${DEFCONFIG_FRAGMENTS}
+}
+append_cmd PRE_DEFCONFIG_CMDS "merge_defconfig_fragments"
+
+# Wrapper function around merge_defconfig_fragment to reduce repeated logic
+# Usage: apply_defconfig_fragment ${KERNEL_DIR}/cuttlefish.fragment cuttlefish-gki_defconfig
+function apply_defconfig_fragment() {
+	FRAGMENT_CONFIG=$1
+	if [ -z "${DEFCONFIG_FRAGMENTS}" ]; then
+		DEFCONFIG_FRAGMENTS="${KERNEL_DIR}/arch/${ARCH}/configs/${DEFCONFIG}"
+	fi
+	DEFCONFIG_FRAGMENTS="${DEFCONFIG_FRAGMENTS} $1"
+	DEFCONFIG="${2:-${DEFCONFIG}}"
+}
+
 function menuconfig() {
+	set +x
+	local orig_defconfig=$(mktemp)
+	local orig_config=$(mktemp)
+
+	cp ${OUT_DIR}/.config ${orig_config}
+	(cd ${KERNEL_DIR} && make "${TOOL_ARGS[@]}" O=${OUT_DIR} ${MAKE_ARGS} savedefconfig)
+	mv ${OUT_DIR}/defconfig ${orig_defconfig}
+
 	(cd ${KERNEL_DIR} && make "${TOOL_ARGS[@]}" O=${OUT_DIR} ${MAKE_ARGS} ${1:-menuconfig})
 	(cd ${KERNEL_DIR} && make "${TOOL_ARGS[@]}" O=${OUT_DIR} ${MAKE_ARGS} savedefconfig)
 	mv ${OUT_DIR}/defconfig ${KERNEL_DIR}/arch/${ARCH}/configs/${DEFCONFIG}
+
+	if [ -z "${FRAGMENT_CONFIG}" ]; then
+		rm "${orig_config}" "${orig_defconfig}"
+		exit
+	fi
+
+	local new_defconfig="${KERNEL_DIR}/arch/${ARCH}/configs/${DEFCONFIG}"
+	local new_config="${OUT_DIR}/.config"
+
+	# CONFIGs to be added
+	# 'defconfig' file should have been generated.
+	# Diff this with the 'defconfig_base' from the previous step and extract only the lines that were added
+	# Finally, remove the "+" from the beginning of the lines and append it to the FRAGMENT
+	diff -u ${orig_defconfig} ${new_defconfig} | grep "^+CONFIG_" | sed 's/^.//' >> ${FRAGMENT_CONFIG}
+
+	# CONFIGs to be removed
+	configs_to_remove=`diff -u ${orig_defconfig} ${new_defconfig} | grep "^-CONFIG_" | sed 's/^.//'`
+	for config_del in $configs_to_remove; do
+		sed -i "/$config_del/d" ${FRAGMENT_CONFIG}
+	done
+
+	# CONFIGs that are unset in base defconfig (# CONFIG_X is not set), but enabled in fragments,
+	# the diff is shown as: -# CONFIG_X is not set. Hence, explicitly set them in the config fragments.
+	configs_to_set=`diff -u ${orig_defconfig} ${new_defconfig} | grep "^-# CONFIG_" | awk '{print $2}'`
+	for config_to_set in $configs_to_set; do
+		# The CONFIG could be set as 'm' in the previous steps. Ignore setting them to 'y'
+		if ! grep -q "$config_to_set" ${FRAGMENT_CONFIG}; then
+			echo $config_to_set=y >> ${FRAGMENT_CONFIG}
+		fi
+	done
+
+	# CONFIGs that are set in base defconfig (or lower fragment), but wanted it to be disabled in FRAG_CONFIG
+	diff -u ${orig_config} ${new_config} | grep "^+# CONFIG_" | sed 's/^.//' >> ${FRAGMENT_CONFIG}
+
+	echo
+	echo "Updated ${FRAGMENT_CONFIG}"
+	echo
+
+	rm "${orig_config}" "${orig_defconfig}"
+	exit
 }
 export -f menuconfig
 # Configuration options to build images for MSM targets

build.config.msm.gki

@@ -1,11 +1,6 @@
 ################################################################################
 # Common MSM configuration for building GKI-based kernels
-
-function generate_defconfig() {
-	${KERNEL_DIR}/scripts/gki/generate_defconfig.sh ${DEFCONFIG}
-}
-DEFCONFIG=vendor/${MSM_ARCH}-${VARIANT}_defconfig
-append_cmd PRE_DEFCONFIG_CMDS 'generate_defconfig'
+DEFCONFIG="gki_defconfig"
 
 if [ -z "${GKI_RAMDISK_PREBUILT_BINARY}" ]; then
 	GKI_RAMDISK_PREBUILT_BINARY=prebuilts/boot-artifacts/${ARCH}/gki-ramdisk.cpio
@@ -14,10 +9,3 @@ fi
 if [ "${BOOT_IMAGE_HEADER_VERSION}" -lt "3" ]; then
 	VENDOR_RAMDISK_BINARY="${GKI_RAMDISK_PREBUILT_BINARY} ${VENDOR_RAMDISK_BINARY}"
 fi
-
-################################################################################
-## menuconfig
-function menuconfig() {
-	${KERNEL_DIR}/scripts/gki/fragment_menuconfig.sh ${DEFCONFIG}
-}
-export -f menuconfig

build.config.msm.lahaina

@@ -30,6 +30,7 @@ KMI_WHITELIST=abi_gki_qcom_whitelist
 case "${VARIANT}" in
 gki)
 	. ${KERNEL_DIR}/build.config.msm.gki
+	apply_defconfig_fragment ${KERNEL_DIR}/arch/${ARCH}/configs/vendor/${MSM_ARCH}_GKI.config vendor/${MSM_ARCH}-gki_defconfig
 	;;
 gki-ack)
 	# In gki-only, then using ACK's GKI config directly

build.config.msm.waipio

@@ -28,6 +28,7 @@ KMI_WHITELIST=abi_gki_qcom_whitelist
 case "${VARIANT}" in
 gki)
 	. ${KERNEL_DIR}/build.config.msm.gki
+	apply_defconfig_fragment ${KERNEL_DIR}/arch/${ARCH}/configs/vendor/${MSM_ARCH}_GKI.config vendor/${MSM_ARCH}-gki_defconfig
 	;;
 gki-ack)
 	# In gki-only, then using ACK's GKI config directly