armbian-next: better ccache logs/stats/Docker-support/use in u-boot/kernel

- introduce `SHOW_CCACHE=yes` for detailed ccache statistics and logging
- fix: kernel build is done under "env -i", so pass CCACHE_DIR down to Make if CCACHE_DIR is set...
- split from kernel.sh, show stats also for u-boot targets; show compile time
- add volume definition (under `${SRC}/cache/ccache`); auto-use that in Docker builds via `CCACHE_DIR`
- better logging for `do_with_ccache_statistics()`
- there's some CCACHE_DIR code from before; unify @TODO

lib/functions/compilation/ccache.sh

@@ -0,0 +1,47 @@
+function do_with_ccache_statistics() {
+	display_alert "Clearing ccache statistics" "ccache" "ccache"
+	run_host_command_logged ccache --zero-stats
+
+	if [[ "${SHOW_CCACHE}" == "yes" ]]; then
+		# show value of CCACHE_DIR
+		display_alert "CCACHE_DIR" "${CCACHE_DIR:-"unset"}" "ccache"
+
+		# determine what is the actual ccache_dir in use
+		local ccache_dir_actual
+		ccache_dir_actual="$(ccache --show-config | grep "cache_dir =" | cut -d "=" -f 2 | xargs echo)"
+
+		# calculate the size of that dir, in bytes.
+		local ccache_dir_size_before ccache_dir_size_after ccache_dir_size_before_human
+		ccache_dir_size_before="$(du -sb "${ccache_dir_actual}" | cut -f 1)"
+		ccache_dir_size_before_human="$(numfmt --to=iec-i --suffix=B --format="%.2f" "${ccache_dir_size_before}")"
+
+		# show the human-readable size of that dir, before we start.
+		display_alert "ccache dir size before" "${ccache_dir_size_before_human}" "ccache"
+
+		# Show the ccache configuration
+		display_alert "ccache configuration" "ccache" "ccache"
+		run_host_command_logged ccache --show-config
+	fi
+
+	display_alert "Running ccache'd build..." "ccache" "ccache"
+	"$@"
+
+	if [[ "${SHOW_CCACHE}" == "yes" ]]; then
+		display_alert "Display ccache statistics" "ccache" "ccache"
+		run_host_command_logged ccache --show-stats --verbose
+
+		# calculate the size of that dir, in bytes, after the compilation.
+		ccache_dir_size_after="$(du -sb "${ccache_dir_actual}" | cut -f 1)"
+
+		# calculate the difference, in bytes.
+		local ccache_dir_size_diff
+		ccache_dir_size_diff="$((ccache_dir_size_after - ccache_dir_size_before))"
+
+		# calculate the difference, in human-readable format; numfmt is from coreutils.
+		local ccache_dir_size_diff_human
+		ccache_dir_size_diff_human="$(numfmt --to=iec-i --suffix=B --format="%.2f" "${ccache_dir_size_diff}")"
+
+		# display the difference
+		display_alert "ccache dir size change" "${ccache_dir_size_diff_human}" "ccache"
+	fi
+}

lib/functions/compilation/kernel.sh

@@ -10,7 +10,6 @@ function run_kernel_make_internal() {
 	declare -a -g DISTCC_MAKE_J_PARALLEL=()
 	prepare_distcc_compilation_config
 
-
 	common_make_envs=(
 		"CCACHE_BASEDIR=\"$(pwd)\""     # Base directory for ccache, for cache reuse # @TODO: experiment with this and the source path to maximize hit rate
 		"PATH=\"${toolchain}:${PATH}\"" # Insert the toolchain first into the PATH.
@@ -19,6 +18,11 @@ function run_kernel_make_internal() {
 		"TERM='${TERM}'"                # Pass the terminal type, so that 'make menuconfig' can work.
 	)
 
+	# If CCACHE_DIR is set, pass it to the kernel build; Pass the ccache dir explicitly, since we'll run under "env -i"
+	if [[ -n "${CCACHE_DIR}" ]]; then
+		common_make_envs+=("CCACHE_DIR='${CCACHE_DIR}'")
+	fi
+
 	# Add the distcc envs, if any.
 	common_make_envs+=("${DISTCC_EXTRA_ENVS[@]}")
 
@@ -35,8 +39,8 @@ function run_kernel_make_internal() {
 
 		"SOURCE_DATE_EPOCH=${kernel_base_revision_ts}"        # https://reproducible-builds.org/docs/source-date-epoch/ and https://www.kernel.org/doc/html/latest/kbuild/reproducible-builds.html
 		"KBUILD_BUILD_TIMESTAMP=${kernel_base_revision_date}" # https://www.kernel.org/doc/html/latest/kbuild/kbuild.html#kbuild-build-timestamp
-		"KBUILD_BUILD_USER=armbian-build"                     # https://www.kernel.org/doc/html/latest/kbuild/kbuild.html#kbuild-build-user-kbuild-build-host
-		"KBUILD_BUILD_HOST=armbian-bm"                        # https://www.kernel.org/doc/html/latest/kbuild/kbuild.html#kbuild-build-user-kbuild-build-host
+		"KBUILD_BUILD_USER=armbian"                           # https://www.kernel.org/doc/html/latest/kbuild/kbuild.html#kbuild-build-user-kbuild-build-host
+		"KBUILD_BUILD_HOST=next"                              # https://www.kernel.org/doc/html/latest/kbuild/kbuild.html#kbuild-build-user-kbuild-build-host
 
 		"KGZIP=pigz" "KBZIP2=pbzip2" # Parallel compression, use explicit parallel compressors https://lore.kernel.org/lkml/20200901151002.988547791@linuxfoundation.org/
 	)
@@ -472,13 +476,3 @@ function kernel_build_and_package() {
 
 	display_alert "Kernel built and packaged in" "$((SECONDS - ts)) seconds - ${version}-${LINUXFAMILY}" "info"
 }
-
-function do_with_ccache_statistics() {
-	display_alert "Clearing ccache statistics" "ccache" "debug"
-	ccache --zero-stats
-
-	"$@"
-
-	display_alert "Display ccache statistics" "ccache" "debug"
-	run_host_command_logged ccache --show-stats
-}

lib/functions/compilation/uboot.sh

@@ -156,16 +156,21 @@ function compile_uboot_target() {
 	cross_compile="CROSS_COMPILE=\"$CCACHE $UBOOT_COMPILER\""
 	[[ -n $UBOOT_TOOLCHAIN2 ]] && cross_compile="ARMBIAN=foe" # empty parameter is not allowed
 
+	local ts=${SECONDS}
+
 	# cflags will be passed both as CFLAGS, KCFLAGS, and both as make params and as env variables.
 	# @TODO make configurable/expandable
 	local uboot_cflags="-fdiagnostics-color=always -Wno-error=maybe-uninitialized -Wno-error=misleading-indentation"
 
 	display_alert "${uboot_prefix}Compiling u-boot" "${version} ${target_make}" "info"
 	export if_error_detail_message="${uboot_prefix}Failed to build u-boot ${version} ${target_make}"
-	run_host_command_logged_long_running "CFLAGS='${uboot_cflags}'" "KCFLAGS='${uboot_cflags}'" \
+	do_with_ccache_statistics run_host_command_logged_long_running \
+		"CFLAGS='${uboot_cflags}'" "KCFLAGS='${uboot_cflags}'" \
 		CCACHE_BASEDIR="$(pwd)" PATH="${toolchain}:${toolchain2}:${PATH}" \
 		unbuffer make "$target_make" "$CTHREADS" "${cross_compile}"
 
+	display_alert "${uboot_prefix}built u-boot target" "${version} in $((SECONDS - ts)) seconds" "info"
+
 	if [[ $(type -t uboot_custom_postprocess) == function ]]; then
 		display_alert "${uboot_prefix}Postprocessing u-boot" "${version} ${target_make}"
 		uboot_custom_postprocess

lib/functions/host/docker.sh

@@ -291,6 +291,9 @@ function docker_cli_prepare_launch() {
 		# Pass env var ARMBIAN_RUNNING_IN_CONTAINER to indicate we're running under Docker. This is also set in the Dockerfile; make sure.
 		"--env" "ARMBIAN_RUNNING_IN_CONTAINER=yes"
 
+		# Change the ccache directory to the named volume or bind created.
+		"--env" "CCACHE_DIR=${DOCKER_ARMBIAN_TARGET_PATH}/cache/ccache"
+
 		# @TODO: if user on terminal, pass the TERM down to the container.
 		"--env" "TERM=${TERM}"
 		# @TODO: pass down the CI-related env vars.

lib/functions/host/mountpoints.sh

@@ -9,6 +9,7 @@ function prepare_armbian_mountpoints_description_dict() {
 		"cache/aptcache"
 		"cache/rootfs" "cache/initrd"
 		"cache/sources" "cache/sources/linux-kernel"
+		"cache/ccache"
 	)
 
 	declare -A -g ARMBIAN_MOUNTPOINTS_DESC_DICT=(
@@ -25,6 +26,7 @@ function prepare_armbian_mountpoints_description_dict() {
 		["cache/initrd"]="docker_kind_linux=bind docker_kind_darwin=namedvolume"               # initrd.img cache, can be bind-mounted or a volume. On Darwin it's too slow to bind-mount, so it's a volume by default. On Linux, it's a bind-mount by default.
 		["cache/sources"]="docker_kind_linux=bind docker_kind_darwin=namedvolume"              # operating directory. many things are cloned in here, and some are even built inside. needs to be local to the container, so it's a volume by default. On Linux, it's a bind-mount by default.
 		["cache/sources/linux-kernel"]="docker_kind_linux=bind docker_kind_darwin=namedvolume" # working tree for kernel builds. huge. contains both sources and the built object files. needs to be local to the container, so it's a volume by default. On Linux, it's a bind-mount by default.
+		["cache/ccache"]="docker_kind_linux=bind docker_kind_darwin=namedvolume"               # ccache object store. limited to 5gb by default. needs to be local to the container, so it's a volume by default. On Linux, it's a bind-mount by default.
 	)
 }
 

lib/functions/logging/logging.sh

@@ -227,6 +227,14 @@ function display_alert() {
 			inline_logs_color="${tool_color}" # either gray or normal, a bit subdued.
 			;;
 
+		ccache)
+			if [[ "${SHOW_CCACHE}" != "yes" ]]; then # ccache-related debugging messages, very very verbose
+				skip_screen=1
+			fi
+			level_indicator="🙈"
+			inline_logs_color="\e[1;34m" # blue; 36 would be cyan
+			;;
+
 		aggregation)
 			if [[ "${SHOW_AGGREGATION}" != "yes" ]]; then # aggregation (PACKAGE LISTS), very very verbose
 				skip_screen=1

lib/library-functions.sh

@@ -136,6 +136,15 @@ set -o errexit  ## set -e : exit the script if any statement returns a non-true
 # shellcheck source=lib/functions/compilation/atf.sh
 source "${SRC}"/lib/functions/compilation/atf.sh
 
+# no errors tolerated. invoked before each sourced file to make sure.
+#set -o pipefail  # trace ERR through pipes - will be enabled "soon"
+#set -o nounset   ## set -u : exit the script if you try to use an uninitialised variable - one day will be enabled
+set -o errtrace # trace ERR through - enabled
+set -o errexit  ## set -e : exit the script if any statement returns a non-true return value - enabled
+### lib/functions/compilation/ccache.sh
+# shellcheck source=lib/functions/compilation/ccache.sh
+source "${SRC}"/lib/functions/compilation/ccache.sh
+
 # no errors tolerated. invoked before each sourced file to make sure.
 #set -o pipefail  # trace ERR through pipes - will be enabled "soon"
 #set -o nounset   ## set -u : exit the script if you try to use an uninitialised variable - one day will be enabled