Index: head/Makefile
===================================================================
--- head/Makefile	(revision 301887)
+++ head/Makefile	(revision 301888)
@@ -1,573 +1,580 @@
 #
 # $FreeBSD$
 #
 # The user-driven targets are:
 #
 # universe            - *Really* build *everything* (buildworld and
 #                       all kernels on all architectures).
 # tinderbox           - Same as universe, but presents a list of failed build
 #                       targets and exits with an error if there were any.
 # buildworld          - Rebuild *everything*, including glue to help do
 #                       upgrades.
 # installworld        - Install everything built by "buildworld".
 # world               - buildworld + installworld, no kernel.
 # buildkernel         - Rebuild the kernel and the kernel-modules.
 # installkernel       - Install the kernel and the kernel-modules.
 # installkernel.debug
 # reinstallkernel     - Reinstall the kernel and the kernel-modules.
 # reinstallkernel.debug
 # kernel              - buildkernel + installkernel.
 # kernel-toolchain    - Builds the subset of world necessary to build a kernel
 # kernel-toolchains   - Build kernel-toolchain for all universe targets.
 # doxygen             - Build API documentation of the kernel, needs doxygen.
 # update              - Convenient way to update your source tree(s).
 # checkworld          - Run test suite on installed world.
 # check-old           - List obsolete directories/files/libraries.
 # check-old-dirs      - List obsolete directories.
 # check-old-files     - List obsolete files.
 # check-old-libs      - List obsolete libraries.
 # delete-old          - Delete obsolete directories/files.
 # delete-old-dirs     - Delete obsolete directories.
 # delete-old-files    - Delete obsolete files.
 # delete-old-libs     - Delete obsolete libraries.
 # targets             - Print a list of supported TARGET/TARGET_ARCH pairs
 #                       for world and kernel targets.
 # toolchains          - Build a toolchain for all world and kernel targets.
 # xdev                - xdev-build + xdev-install for the architecture
 #                       specified with XDEV and XDEV_ARCH.
 # xdev-build          - Build cross-development tools.
 # xdev-install        - Install cross-development tools.
 # xdev-links          - Create traditional links in /usr/bin for cc, etc
 # native-xtools       - Create host binaries that produce target objects
 #                       for use in qemu user-mode jails.
 # 
 # "quick" way to test all kernel builds:
 # 	_jflag=`sysctl -n hw.ncpu`
 # 	_jflag=$(($_jflag * 2))
 # 	[ $_jflag -gt 12 ] && _jflag=12
 # 	make universe -DMAKE_JUST_KERNELS JFLAG=-j${_jflag}
 #
 # This makefile is simple by design. The FreeBSD make automatically reads
 # the /usr/share/mk/sys.mk unless the -m argument is specified on the
 # command line. By keeping this makefile simple, it doesn't matter too
 # much how different the installed mk files are from those in the source
 # tree. This makefile executes a child make process, forcing it to use
 # the mk files from the source tree which are supposed to DTRT.
 #
 # Most of the user-driven targets (as listed above) are implemented in
 # Makefile.inc1.  The exceptions are universe, tinderbox and targets.
 #
 # If you want to build your system from source be sure that /usr/obj has
 # at least 6GB of diskspace available.  A complete 'universe' build requires
 # about 100GB of space.
 #
 # For individuals wanting to build from the sources currently on their
 # system, the simple instructions are:
 #
 # 1.  `cd /usr/src'  (or to the directory containing your source tree).
 # 2.  Define `HISTORICAL_MAKE_WORLD' variable (see README).
 # 3.  `make world'
 #
 # For individuals wanting to upgrade their sources (even if only a
 # delta of a few days):
 #
 #  1.  `cd /usr/src'       (or to the directory containing your source tree).
 #  2.  `make buildworld'
 #  3.  `make buildkernel KERNCONF=YOUR_KERNEL_HERE'     (default is GENERIC).
 #  4.  `make installkernel KERNCONF=YOUR_KERNEL_HERE'   (default is GENERIC).
 #       [steps 3. & 4. can be combined by using the "kernel" target]
 #  5.  `reboot'        (in single user mode: boot -s from the loader prompt).
 #  6.  `mergemaster -p'
 #  7.  `make installworld'
 #  8.  `mergemaster'		(you may wish to use -i, along with -U or -F).
 #  9.  `make delete-old'
 # 10.  `reboot'
 # 11.  `make delete-old-libs' (in case no 3rd party program uses them anymore)
 #
 # See src/UPDATING `COMMON ITEMS' for more complete information.
 #
 # If TARGET=machine (e.g. powerpc, sparc64, ...) is specified you can
 # cross build world for other machine types using the buildworld target,
 # and once the world is built you can cross build a kernel using the
 # buildkernel target.
 #
 # Define the user-driven targets. These are listed here in alphabetical
 # order, but that's not important.
 #
 # Targets that begin with underscore are internal targets intended for
 # developer convenience only.  They are intentionally not documented and
 # completely subject to change without notice.
 #
 # For more information, see the build(7) manual page.
 #
 
 # This is included so CC is set to ccache for -V, and COMPILER_TYPE/VERSION
 # can be cached for sub-makes.
 .if ${MAKE_VERSION} >= 20140620
 .include <bsd.compiler.mk>
 .endif
 
 # Note: we use this awkward construct to be compatible with FreeBSD's
 # old make used in 10.0 and 9.2 and earlier.
 .if defined(MK_DIRDEPS_BUILD) && ${MK_DIRDEPS_BUILD} == "yes" && !make(showconfig)
 # targets/Makefile plays the role of top-level
 .include "targets/Makefile"
 .else
 
 TGTS=	all all-man buildenv buildenvvars buildkernel buildworld \
 	check check-old check-old-dirs check-old-files check-old-libs \
 	checkdpadd checkworld clean cleandepend cleandir cleanworld \
 	delete-old delete-old-dirs delete-old-files delete-old-libs \
 	depend distribute distributekernel distributekernel.debug \
 	distributeworld distrib-dirs distribution doxygen \
 	everything hier hierarchy install installcheck installkernel \
 	installkernel.debug packagekernel packageworld \
 	reinstallkernel reinstallkernel.debug \
 	installworld kernel-toolchain libraries lint maninstall \
 	obj objlink rerelease showconfig tags toolchain update \
 	_worldtmp _legacy _bootstrap-tools _cleanobj _obj \
 	_build-tools _cross-tools _includes _libraries \
 	build32 distribute32 install32 buildsoft distributesoft installsoft \
 	builddtb xdev xdev-build xdev-install \
 	xdev-links native-xtools stageworld stagekernel stage-packages \
 	create-world-packages create-kernel-packages create-packages \
 	packages installconfig real-packages sign-packages package-pkg
 
 # XXX: r156740: This can't work since bsd.subdir.mk is not included ever.
 # It will only work for SUBDIR_TARGETS in make.conf.
 TGTS+=	${SUBDIR_TARGETS}
 
 BITGTS=	files includes
 BITGTS:=${BITGTS} ${BITGTS:S/^/build/} ${BITGTS:S/^/install/}
 TGTS+=	${BITGTS}
 
 # Only some targets are allowed to use meta mode.  Others get it
 # disabled.  In some cases, such as 'install', meta mode can be dangerous
 # as a cookie may be used to prevent redundant installations (such as
 # for WORLDTMP staging).  For DESTDIR=/ we always want to install though.
 # For other cases, such as delete-old-libs, meta mode may break
 # the interactive tty prompt.  The safest route is to just whitelist
 # the ones that benefit from it.
 META_TGT_WHITELIST+= \
 	_* build32 buildfiles buildincludes buildkernel buildsoft \
 	buildworld everything kernel-toolchains kernels libraries \
 	native-xtools tinderbox toolchain toolchains universe worlds \
 	xdev xdev-build
 
 .ORDER: buildworld installworld
 .ORDER: buildworld distributeworld
 .ORDER: buildworld buildkernel
 .ORDER: installworld distribution
 .ORDER: installworld installkernel
 .ORDER: buildkernel installkernel
 .ORDER: buildkernel installkernel.debug
 .ORDER: buildkernel reinstallkernel
 .ORDER: buildkernel reinstallkernel.debug
 
 PATH=	/sbin:/bin:/usr/sbin:/usr/bin
 MAKEOBJDIRPREFIX?=	/usr/obj
 _MAKEOBJDIRPREFIX!= /usr/bin/env -i PATH=${PATH} MK_AUTO_OBJ=no ${MAKE} \
     ${.MAKEFLAGS:MMAKEOBJDIRPREFIX=*} __MAKE_CONF=${__MAKE_CONF} \
     -f /dev/null -V MAKEOBJDIRPREFIX dummy
 .if !empty(_MAKEOBJDIRPREFIX)
 .error MAKEOBJDIRPREFIX can only be set in environment, not as a global\
 	(in make.conf(5)) or command-line variable.
 .endif
 
 # We often need to use the tree's version of make to build it.
 # Choices add to complexity though.
 # We cannot blindly use a make which may not be the one we want
 # so be exlicit - until all choice is removed.
 WANT_MAKE=	bmake
 .if !empty(.MAKE.MODE:Mmeta)
 # 20160604 - support missing-meta,missing-filemon and performance improvements
 WANT_MAKE_VERSION= 20160604
 .else
 # 20160220 - support .dinclude for FAST_DEPEND.
 WANT_MAKE_VERSION= 20160220
 .endif
 MYMAKE=		${MAKEOBJDIRPREFIX}${.CURDIR}/make.${MACHINE}/${WANT_MAKE}
 .if defined(.PARSEDIR)
 HAVE_MAKE=	bmake
 .else
 HAVE_MAKE=	fmake
 .endif
 .if ${HAVE_MAKE} != ${WANT_MAKE} || \
     (defined(WANT_MAKE_VERSION) && ${MAKE_VERSION} < ${WANT_MAKE_VERSION})
 NEED_MAKE_UPGRADE= t
 .endif
 .if exists(${MYMAKE})
 SUB_MAKE:= ${MYMAKE} -m ${.CURDIR}/share/mk
 .elif defined(NEED_MAKE_UPGRADE)
 # It may not exist yet but we may cause it to.
 # In the case of fmake, upgrade_checks may cause a newer version to be built.
 SUB_MAKE= `test -x ${MYMAKE} && echo ${MYMAKE} || echo ${MAKE}` \
 	-m ${.CURDIR}/share/mk
 .else
 SUB_MAKE= ${MAKE} -m ${.CURDIR}/share/mk
 .endif
 
 _MAKE=	PATH=${PATH} ${SUB_MAKE} -f Makefile.inc1 TARGET=${_TARGET} TARGET_ARCH=${_TARGET_ARCH}
 
 # Only allow meta mode for the whitelisted targets.  See META_TGT_WHITELIST
 # above.
 .for _tgt in ${META_TGT_WHITELIST}
 .if make(${_tgt})
 _CAN_USE_META_MODE?= yes
 .endif
 .endfor
 .if !defined(_CAN_USE_META_MODE)
 _MAKE+=	MK_META_MODE=no
 .unexport META_MODE
+.elif ${MK_META_MODE} == "yes"
+.if !exists(/dev/filemon) && !defined(NO_FILEMON) && !make(showconfig)
+# Require filemon be loaded to provide a working incremental build
+.error ${.newline}ERROR: The filemon module (/dev/filemon) is not loaded. \
+    ${.newline}ERROR: WITH_META_MODE is enabled but requires filemon for an incremental build. \
+    ${.newline}ERROR: 'kldload filemon' or pass -DNO_FILEMON to suppress this error.
+.endif	# !exists(/dev/filemon) && !defined(NO_FILEMON)
 .endif	# !defined(_CAN_USE_META_MODE)
 
 # Guess machine architecture from machine type, and vice versa.
 .if !defined(TARGET_ARCH) && defined(TARGET)
 _TARGET_ARCH=	${TARGET:S/pc98/i386/:S/arm64/aarch64/}
 .elif !defined(TARGET) && defined(TARGET_ARCH) && \
     ${TARGET_ARCH} != ${MACHINE_ARCH}
 _TARGET=		${TARGET_ARCH:C/mips(n32|64)?(el)?/mips/:C/arm(v6)?(eb)?/arm/:C/aarch64/arm64/:C/powerpc64/powerpc/:C/riscv64/riscv/}
 .endif
 .if defined(TARGET) && !defined(_TARGET)
 _TARGET=${TARGET}
 .endif
 .if defined(TARGET_ARCH) && !defined(_TARGET_ARCH)
 _TARGET_ARCH=${TARGET_ARCH}
 .endif
 # for historical compatibility for xdev targets
 .if defined(XDEV)
 _TARGET=	${XDEV}
 .endif
 .if defined(XDEV_ARCH)
 _TARGET_ARCH=	${XDEV_ARCH}
 .endif
 # Otherwise, default to current machine type and architecture.
 _TARGET?=	${MACHINE}
 _TARGET_ARCH?=	${MACHINE_ARCH}
 
 #
 # Make sure we have an up-to-date make(1). Only world and buildworld
 # should do this as those are the initial targets used for upgrades.
 # The user can define ALWAYS_CHECK_MAKE to have this check performed
 # for all targets.
 #
 .if defined(ALWAYS_CHECK_MAKE) || !defined(.PARSEDIR)
 ${TGTS}: upgrade_checks
 .else
 buildworld: upgrade_checks
 .endif
 
 #
 # Handle the user-driven targets, using the source relative mk files.
 #
 
 tinderbox toolchains kernel-toolchains: .MAKE
 ${TGTS}: .PHONY .MAKE
 	${_+_}@cd ${.CURDIR}; ${_MAKE} ${.TARGET}
 
 # The historic default "all" target creates files which may cause stale
 # or (in the cross build case) unlinkable results. Fail with an error
 # when no target is given. The users can explicitly specify "all"
 # if they want the historic behavior.
 .MAIN:	_guard
 
 _guard: .PHONY
 	@echo
 	@echo "Explicit target required.  Likely \"${SUBDIR_OVERRIDE:Dall:Ubuildworld}\" is wanted.  See build(7)."
 	@echo
 	@false
 
 STARTTIME!= LC_ALL=C date
 CHECK_TIME!= find ${.CURDIR}/sys/sys/param.h -mtime -0s ; echo
 .if !empty(CHECK_TIME)
 .error check your date/time: ${STARTTIME}
 .endif
 
 .if defined(HISTORICAL_MAKE_WORLD) || defined(DESTDIR)
 #
 # world
 #
 # Attempt to rebuild and reinstall everything. This target is not to be
 # used for upgrading an existing FreeBSD system, because the kernel is
 # not included. One can argue that this target doesn't build everything
 # then.
 #
 world: upgrade_checks .PHONY
 	@echo "--------------------------------------------------------------"
 	@echo ">>> make world started on ${STARTTIME}"
 	@echo "--------------------------------------------------------------"
 .if target(pre-world)
 	@echo
 	@echo "--------------------------------------------------------------"
 	@echo ">>> Making 'pre-world' target"
 	@echo "--------------------------------------------------------------"
 	${_+_}@cd ${.CURDIR}; ${_MAKE} pre-world
 .endif
 	${_+_}@cd ${.CURDIR}; ${_MAKE} buildworld
 	${_+_}@cd ${.CURDIR}; ${_MAKE} -B installworld
 .if target(post-world)
 	@echo
 	@echo "--------------------------------------------------------------"
 	@echo ">>> Making 'post-world' target"
 	@echo "--------------------------------------------------------------"
 	${_+_}@cd ${.CURDIR}; ${_MAKE} post-world
 .endif
 	@echo
 	@echo "--------------------------------------------------------------"
 	@echo ">>> make world completed on `LC_ALL=C date`"
 	@echo "                   (started ${STARTTIME})"
 	@echo "--------------------------------------------------------------"
 .else
 world: .PHONY
 	@echo "WARNING: make world will overwrite your existing FreeBSD"
 	@echo "installation without also building and installing a new"
 	@echo "kernel.  This can be dangerous.  Please read the handbook,"
 	@echo "'Rebuilding world', for how to upgrade your system."
 	@echo "Define DESTDIR to where you want to install FreeBSD,"
 	@echo "including /, to override this warning and proceed as usual."
 	@echo ""
 	@echo "Bailing out now..."
 	@false
 .endif
 
 #
 # kernel
 #
 # Short hand for `make buildkernel installkernel'
 #
 kernel: buildkernel installkernel .PHONY
 
 #
 # Perform a few tests to determine if the installed tools are adequate
 # for building the world.
 #
 upgrade_checks: .PHONY
 .if defined(NEED_MAKE_UPGRADE)
 	@${_+_}(cd ${.CURDIR} && ${MAKE} ${WANT_MAKE:S,^f,,})
 .endif
 
 #
 # Upgrade make(1) to the current version using the installed
 # headers, libraries and tools.  Also, allow the location of
 # the system bsdmake-like utility to be overridden.
 #
 MMAKEENV=	MAKEOBJDIRPREFIX=${MYMAKE:H} \
 		DESTDIR= \
 		INSTALL="sh ${.CURDIR}/tools/install.sh"
 MMAKE=		${MMAKEENV} ${MAKE} \
 		MAN= -DNO_SHARED \
 		-DNO_CPU_CFLAGS -DNO_WERROR \
 		-DNO_SUBDIR \
 		DESTDIR= PROGNAME=${MYMAKE:T}
 
 bmake: .PHONY
 	@echo
 	@echo "--------------------------------------------------------------"
 	@echo ">>> Building an up-to-date ${.TARGET}(1)"
 	@echo "--------------------------------------------------------------"
 	${_+_}@cd ${.CURDIR}/usr.bin/${.TARGET}; \
 		${MMAKE} obj; \
 		${MMAKE} depend; \
 		${MMAKE} all; \
 		${MMAKE} install DESTDIR=${MYMAKE:H} BINDIR=
 
 regress: .PHONY
 	@echo "'make regress' has been renamed 'make check'" | /usr/bin/fmt
 	@false
 
 tinderbox toolchains kernel-toolchains kernels worlds: upgrade_checks
 
 tinderbox: .PHONY
 	@cd ${.CURDIR}; ${SUB_MAKE} DOING_TINDERBOX=YES universe
 
 toolchains: .PHONY
 	@cd ${.CURDIR}; ${SUB_MAKE} UNIVERSE_TARGET=toolchain universe
 
 kernel-toolchains: .PHONY
 	@cd ${.CURDIR}; ${SUB_MAKE} UNIVERSE_TARGET=kernel-toolchain universe
 
 kernels: .PHONY
 	@cd ${.CURDIR}; ${SUB_MAKE} UNIVERSE_TARGET=buildkernel universe
 
 worlds: .PHONY
 	@cd ${.CURDIR}; ${SUB_MAKE} UNIVERSE_TARGET=buildworld universe
 
 #
 # universe
 #
 # Attempt to rebuild *everything* for all supported architectures,
 # with a reasonable chance of success, regardless of how old your
 # existing system is.
 #
 .if make(universe) || make(universe_kernels) || make(tinderbox) || make(targets)
 TARGETS?=amd64 arm arm64 i386 mips pc98 powerpc sparc64
 _UNIVERSE_TARGETS=	${TARGETS}
 TARGET_ARCHES_arm?=	arm armeb armv6
 TARGET_ARCHES_arm64?=	aarch64
 TARGET_ARCHES_mips?=	mipsel mips mips64el mips64 mipsn32
 TARGET_ARCHES_powerpc?=	powerpc powerpc64
 TARGET_ARCHES_pc98?=	i386
 .for target in ${TARGETS}
 TARGET_ARCHES_${target}?= ${target}
 .endfor
 
 # XXX Add arm64 to universe only if we have an external binutils installed.
 # It does not build with the in-tree linker.
 .if !exists(/usr/local/aarch64-freebsd/bin/ld) && empty(${TARGETS})
 _UNIVERSE_TARGETS:= ${_UNIVERSE_TARGETS:Narm64}
 universe: universe_arm64_skip .PHONY
 universe_epilogue: universe_arm64_skip .PHONY
 universe_arm64_skip: universe_prologue .PHONY
 	@echo ">> arm64 skipped - install aarch64-binutils port or package to build"
 .endif
 
 .if defined(UNIVERSE_TARGET)
 MAKE_JUST_WORLDS=	YES
 .else
 UNIVERSE_TARGET?=	buildworld
 .endif
 KERNSRCDIR?=		${.CURDIR}/sys
 
 targets:	.PHONY
 	@echo "Supported TARGET/TARGET_ARCH pairs for world and kernel targets"
 .for target in ${TARGETS}
 .for target_arch in ${TARGET_ARCHES_${target}}
 	@echo "    ${target}/${target_arch}"
 .endfor
 .endfor
 
 .if defined(DOING_TINDERBOX)
 FAILFILE=${.CURDIR}/_.tinderbox.failed
 MAKEFAIL=tee -a ${FAILFILE}
 .else
 MAKEFAIL=cat
 .endif
 
 universe_prologue:  upgrade_checks
 universe: universe_prologue
 universe_prologue: .PHONY
 	@echo "--------------------------------------------------------------"
 	@echo ">>> make universe started on ${STARTTIME}"
 	@echo "--------------------------------------------------------------"
 .if defined(DOING_TINDERBOX)
 	@rm -f ${FAILFILE}
 .endif
 .for target in ${_UNIVERSE_TARGETS}
 universe: universe_${target}
 universe_epilogue: universe_${target}
 universe_${target}: universe_${target}_prologue .PHONY
 universe_${target}_prologue: universe_prologue .PHONY
 	@echo ">> ${target} started on `LC_ALL=C date`"
 universe_${target}_worlds: .PHONY
 
 .if !defined(MAKE_JUST_KERNELS)
 universe_${target}_done: universe_${target}_worlds .PHONY
 .for target_arch in ${TARGET_ARCHES_${target}}
 universe_${target}_worlds: universe_${target}_${target_arch} .PHONY
 universe_${target}_${target_arch}: universe_${target}_prologue .MAKE .PHONY
 	@echo ">> ${target}.${target_arch} ${UNIVERSE_TARGET} started on `LC_ALL=C date`"
 	@(cd ${.CURDIR} && env __MAKE_CONF=/dev/null \
 	    ${SUB_MAKE} ${JFLAG} ${UNIVERSE_TARGET} \
 	    TARGET=${target} \
 	    TARGET_ARCH=${target_arch} \
 	    > _.${target}.${target_arch}.${UNIVERSE_TARGET} 2>&1 || \
 	    (echo "${target}.${target_arch} ${UNIVERSE_TARGET} failed," \
 	    "check _.${target}.${target_arch}.${UNIVERSE_TARGET} for details" | \
 	    ${MAKEFAIL}))
 	@echo ">> ${target}.${target_arch} ${UNIVERSE_TARGET} completed on `LC_ALL=C date`"
 .endfor
 .endif # !MAKE_JUST_KERNELS
 
 .if !defined(MAKE_JUST_WORLDS)
 universe_${target}_done: universe_${target}_kernels .PHONY
 universe_${target}_kernels: universe_${target}_worlds .PHONY
 universe_${target}_kernels: universe_${target}_prologue .MAKE .PHONY
 .if exists(${KERNSRCDIR}/${target}/conf/NOTES)
 	@(cd ${KERNSRCDIR}/${target}/conf && env __MAKE_CONF=/dev/null \
 	    ${SUB_MAKE} LINT > ${.CURDIR}/_.${target}.makeLINT 2>&1 || \
 	    (echo "${target} 'make LINT' failed," \
 	    "check _.${target}.makeLINT for details"| ${MAKEFAIL}))
 .endif
 	@cd ${.CURDIR}; ${SUB_MAKE} ${.MAKEFLAGS} TARGET=${target} \
 	    universe_kernels
 .endif # !MAKE_JUST_WORLDS
 
 # Tell the user the worlds and kernels have completed
 universe_${target}: universe_${target}_done
 universe_${target}_done:
 	@echo ">> ${target} completed on `LC_ALL=C date`"
 .endfor
 universe_kernels: universe_kernconfs .PHONY
 .if !defined(TARGET)
 TARGET!=	uname -m
 .endif
 .if defined(MAKE_ALL_KERNELS)
 _THINNER=cat
 .else
 _THINNER=xargs grep -L "^.NO_UNIVERSE" || true
 .endif
 KERNCONFS!=	cd ${KERNSRCDIR}/${TARGET}/conf && \
 		find [[:upper:][:digit:]]*[[:upper:][:digit:]] \
 		-type f -maxdepth 0 \
 		! -name DEFAULTS ! -name NOTES | \
 		${_THINNER}
 universe_kernconfs: .PHONY
 .for kernel in ${KERNCONFS}
 TARGET_ARCH_${kernel}!=	cd ${KERNSRCDIR}/${TARGET}/conf && \
 	config -m ${KERNSRCDIR}/${TARGET}/conf/${kernel} 2> /dev/null | \
 	grep -v WARNING: | cut -f 2
 .if empty(TARGET_ARCH_${kernel})
 .error "Target architecture for ${TARGET}/conf/${kernel} unknown.  config(8) likely too old."
 .endif
 universe_kernconfs: universe_kernconf_${TARGET}_${kernel}
 universe_kernconf_${TARGET}_${kernel}: .MAKE
 	@(cd ${.CURDIR} && env __MAKE_CONF=/dev/null \
 	    ${SUB_MAKE} ${JFLAG} buildkernel \
 	    TARGET=${TARGET} \
 	    TARGET_ARCH=${TARGET_ARCH_${kernel}} \
 	    KERNCONF=${kernel} \
 	    > _.${TARGET}.${kernel} 2>&1 || \
 	    (echo "${TARGET} ${kernel} kernel failed," \
 	    "check _.${TARGET}.${kernel} for details"| ${MAKEFAIL}))
 .endfor
 universe: universe_epilogue
 universe_epilogue: .PHONY
 	@echo "--------------------------------------------------------------"
 	@echo ">>> make universe completed on `LC_ALL=C date`"
 	@echo "                      (started ${STARTTIME})"
 	@echo "--------------------------------------------------------------"
 .if defined(DOING_TINDERBOX)
 	@if [ -e ${FAILFILE} ] ; then \
 		echo "Tinderbox failed:" ;\
 		cat ${FAILFILE} ;\
 		exit 1 ;\
 	fi
 .endif
 .endif
 
 buildLINT: .PHONY
 	${MAKE} -C ${.CURDIR}/sys/${_TARGET}/conf LINT
 
 .if defined(.PARSEDIR)
 # This makefile does not run in meta mode
 .MAKE.MODE= normal
 # Normally the things we run from here don't either.
 # Using -DWITH_META_MODE
 # we can buildworld with meta files created which are useful 
 # for debugging, but without any of the rest of a meta mode build.
 MK_DIRDEPS_BUILD= no
 MK_STAGING= no
 # tell meta.autodep.mk to not even think about updating anything.
 UPDATE_DEPENDFILE= NO
 .if !make(showconfig)
 .export MK_DIRDEPS_BUILD MK_STAGING UPDATE_DEPENDFILE
 .endif
 
 .if make(universe)
 # we do not want a failure of one branch abort all.
 MAKE_JOB_ERROR_TOKEN= no
 .export MAKE_JOB_ERROR_TOKEN
 .endif
 .endif # bmake
 
 .endif				# DIRDEPS_BUILD
Index: head/share/mk/bsd.init.mk
===================================================================
--- head/share/mk/bsd.init.mk	(revision 301887)
+++ head/share/mk/bsd.init.mk	(revision 301888)
@@ -1,31 +1,41 @@
 # $FreeBSD$
 
 # The include file <bsd.init.mk> includes <bsd.opts.mk>,
 # ../Makefile.inc and <bsd.own.mk>; this is used at the
 # top of all <bsd.*.mk> files that actually "build something".
 # bsd.opts.mk is included early so Makefile.inc can use the
 # MK_FOO variables.
 
 .if !target(__<bsd.init.mk>__)
 __<bsd.init.mk>__:
 .include <bsd.opts.mk>
 .-include "local.init.mk"
 .if exists(${.CURDIR}/../Makefile.inc)
 .include "${.CURDIR}/../Makefile.inc"
 .endif
 .include <bsd.own.mk>
 .MAIN: all
 beforebuild: .PHONY .NOTMAIN
 .if !defined(_SKIP_BUILD)
 all: beforebuild .WAIT
 .endif
 
 .if ${.MAKE.LEVEL:U1} == 0 && ${BUILD_AT_LEVEL0:Uyes:tl} == "no" && !make(clean*)
 # this tells lib.mk and prog.mk to not actually build anything
 _SKIP_BUILD = not building at level 0
 .endif
 .if ${.MAKE.LEVEL} > 0 && !empty(_SKIP_BUILD)
 .warning ${_SKIP_BUILD}
 .endif
 
+.if ${MK_META_MODE} == "yes"
+.if !exists(/dev/filemon) && \
+    ${UPDATE_DEPENDFILE:Uyes:tl} != "no" && !defined(NO_FILEMON) && \
+    !make(showconfig)
+.warning The filemon module (/dev/filemon) is not loaded.
+.warning META_MODE is less useful for incremental builds without filemon.
+.warning 'kldload filemon' or pass -DNO_FILEMON to suppress this warning.
+.endif
+.endif	# ${MK_META_MODE} == "yes"
+
 .endif	# !target(__<bsd.init.mk>__)
Index: head/share/mk/sys.mk
===================================================================
--- head/share/mk/sys.mk	(revision 301887)
+++ head/share/mk/sys.mk	(revision 301888)
@@ -1,470 +1,466 @@
 #	from: @(#)sys.mk	8.2 (Berkeley) 3/21/94
 # $FreeBSD$
 
 unix		?=	We run FreeBSD, not UNIX.
 .FreeBSD	?=	true
 
 .if !defined(%POSIX)
 #
 # MACHINE_CPUARCH defines a collection of MACHINE_ARCH.  Machines with
 # the same MACHINE_ARCH can run each other's binaries, so it necessarily
 # has word size and endian swizzled in.  However, support files for
 # these machines often are shared amongst all combinations of size
 # and/or endian.  This is called MACHINE_CPU in NetBSD, but that's used
 # for something different in FreeBSD.
 #
 MACHINE_CPUARCH=${MACHINE_ARCH:C/mips(n32|64)?(el)?/mips/:C/arm(v6)?(eb|hf)?/arm/:C/powerpc64/powerpc/:C/riscv64/riscv/}
 .endif
 
 
 # Some options we need now
 __DEFAULT_NO_OPTIONS= \
 	DIRDEPS_BUILD \
 	DIRDEPS_CACHE
 
 __DEFAULT_DEPENDENT_OPTIONS= \
 	AUTO_OBJ/DIRDEPS_BUILD \
 	META_MODE/DIRDEPS_BUILD \
 	STAGING/DIRDEPS_BUILD \
 	SYSROOT/DIRDEPS_BUILD
 
 __ENV_ONLY_OPTIONS:= \
 	${__DEFAULT_NO_OPTIONS} \
 	${__DEFAULT_YES_OPTIONS} \
 	${__DEFAULT_DEPENDENT_OPTIONS:H}
 
 # early include for customization
 # see local.sys.mk below
 # Not included when building in fmake compatibility mode (still needed
 # for older system support)
 .if defined(.PARSEDIR)
 .sinclude <local.sys.env.mk>
 
 .include <bsd.mkopt.mk>
 
 # Disable MK_META_MODE with make -B
 .if ${MK_META_MODE} == "yes" && defined(.MAKEFLAGS) && ${.MAKEFLAGS:M-B}
 MK_META_MODE=	no
 .endif
 
 .if ${MK_DIRDEPS_BUILD} == "yes"
 .sinclude <meta.sys.mk>
 .elif ${MK_META_MODE} == "yes"
 # verbose will show .MAKE.META.PREFIX for each target.
 META_MODE+=	meta verbose
 .if !defined(NO_META_MISSING)
 META_MODE+=	missing-meta=yes
 .endif
 # silent will hide command output if a .meta file is created.
 .if !defined(NO_SILENT)
 META_MODE+=	silent=yes
 .endif
 .if !exists(/dev/filemon)
-.if ${UPDATE_DEPENDFILE:Uyes:tl} != "no" && !defined(NO_FILEMON) && \
-    !make(showconfig)
-.error ${.newline}ERROR: The filemon module (/dev/filemon) is not loaded.
-.endif
 META_MODE+= nofilemon
 .endif
 # Require filemon data with bmake
 .if empty(META_MODE:Mnofilemon)
 META_MODE+= missing-filemon=yes
 .endif
 .endif
 META_MODE?= normal
 .export META_MODE
 .MAKE.MODE?= ${META_MODE}
 .if !empty(.MAKE.MODE:Mmeta) && !defined(NO_META_IGNORE_HOST)
 # Ignore host file changes that will otherwise cause
 # buildworld -> installworld -> buildworld to rebuild everything.
 # Since the build is self-reliant and bootstraps everything it needs,
 # this should not be a real problem for incremental builds.
 # Note that these are prefix matching, so /lib matches /libexec.
 .MAKE.META.IGNORE_PATHS+= \
 	${__MAKE_SHELL} \
 	/bin \
 	/lib \
 	/rescue \
 	/sbin \
 	/usr/bin \
 	/usr/include \
 	/usr/lib \
 	/usr/sbin \
 	/usr/share \
 
 .endif
 
 
 .if ${MK_AUTO_OBJ} == "yes"
 # This needs to be done early - before .PATH is computed
 # Don't do this for 'make showconfig' as it enables all options where meta mode
 # is not expected.
 .if !make(showconfig)
 .sinclude <auto.obj.mk>
 .endif
 .endif
 .else # bmake
 .include <bsd.mkopt.mk>
 .endif
 
 # If the special target .POSIX appears (without prerequisites or
 # commands) before the first noncomment line in the makefile, make shall
 # process the makefile as specified by the Posix 1003.2 specification.
 # make(1) sets the special macro %POSIX in this case (to the actual
 # value "1003.2", for what it's worth).
 #
 # The rules below use this macro to distinguish between Posix-compliant
 # and default behaviour.
 #
 # This functionality is currently broken, since make(1) processes sys.mk
 # before reading any other files, and consequently has no opportunity to
 # set the %POSIX macro before we read this point.
 
 .if defined(%POSIX)
 .SUFFIXES:	.o .c .y .l .a .sh .f
 .else
 .SUFFIXES:	.out .a .ln .o .c .cc .cpp .cxx .C .m .F .f .e .r .y .l .S .asm .s .cl .p .h .sh
 .endif
 
 AR		?=	ar
 .if defined(%POSIX)
 ARFLAGS		?=	-rv
 .else
 ARFLAGS		?=	-crD
 .endif
 RANLIB		?=	ranlib
 .if !defined(%POSIX)
 RANLIBFLAGS	?=	-D
 .endif
 
 AS		?=	as
 AFLAGS		?=
 ACFLAGS		?=
 
 .if defined(%POSIX)
 CC		?=	c89
 CFLAGS		?=	-O
 .else
 CC		?=	cc
 .if ${MACHINE_CPUARCH} == "arm" || ${MACHINE_CPUARCH} == "mips"
 CFLAGS		?=	-O -pipe
 .else
 CFLAGS		?=	-O2 -pipe
 .endif
 .if defined(NO_STRICT_ALIASING)
 CFLAGS		+=	-fno-strict-aliasing
 .endif
 .endif
 PO_CFLAGS	?=	${CFLAGS}
 
 # cp(1) is used to copy source files to ${.OBJDIR}, make sure it can handle
 # read-only files as non-root by passing -f.
 CP		?=	cp -f
 
 CPP		?=	cpp
 
 # C Type Format data is required for DTrace
 CTFFLAGS	?=	-L VERSION
 
 CTFCONVERT	?=	ctfconvert
 CTFMERGE	?=	ctfmerge
 
 .if defined(CFLAGS) && (${CFLAGS:M-g} != "")
 CTFFLAGS	+=	-g
 .endif
 
 CXX		?=	c++
 CXXFLAGS	?=	${CFLAGS:N-std=*:N-Wnested-externs:N-W*-prototypes:N-Wno-pointer-sign:N-Wold-style-definition}
 PO_CXXFLAGS	?=	${CXXFLAGS}
 
 DTRACE		?=	dtrace
 DTRACEFLAGS	?=	-C -x nolibs
 
 .if empty(.MAKEFLAGS:M-s)
 ECHO		?=	echo
 ECHODIR		?=	echo
 .else
 ECHO		?=	true
 .if ${.MAKEFLAGS:M-s} == "-s"
 ECHODIR		?=	echo
 .else
 ECHODIR		?=	true
 .endif
 .endif
 
 .if ${.MAKEFLAGS:M-N}
 # bmake -N is supposed to skip executing anything but it does not skip
 # exeucting '+' commands.  The '+' feature is used where .MAKE
 # is not safe for the entire target.  -N is intended to skip building sub-makes
 # so it executing '+' commands is not right.  Work around the bug by not
 # setting '+' when -N is used.
 _+_		?=
 .else
 _+_		?=	+
 .endif
 
 .if defined(%POSIX)
 FC		?=	fort77
 FFLAGS		?=	-O 1
 .else
 FC		?=	f77
 FFLAGS		?=	-O
 .endif
 EFLAGS		?=
 
 INSTALL		?=	install
 
 LEX		?=	lex
 LFLAGS		?=
 
 LD		?=	ld
 LDFLAGS		?=				# LDFLAGS is for CC, 
 _LDFLAGS	=	${LDFLAGS:S/-Wl,//g}	# strip -Wl, for LD
 
 LINT		?=	lint
 LINTFLAGS	?=	-cghapbx
 LINTKERNFLAGS	?=	${LINTFLAGS}
 LINTOBJFLAGS	?=	-cghapbxu -i
 LINTOBJKERNFLAGS?=	${LINTOBJFLAGS}
 LINTLIBFLAGS	?=	-cghapbxu -C ${LIB}
 
 MAKE		?=	make
 
 .if !defined(%POSIX)
 NM		?=	nm
 NMFLAGS		?=
 
 OBJC		?=	cc
 OBJCFLAGS	?=	${OBJCINCLUDES} ${CFLAGS} -Wno-import
 
 OBJCOPY		?=	objcopy
 
 OBJDUMP		?=	objdump
 
 PC		?=	pc
 PFLAGS		?=
 
 RC		?=	f77
 RFLAGS		?=
 .endif
 
 SHELL		?=	sh
 
 .if !defined(%POSIX)
 SIZE		?=	size
 .endif
 
 YACC		?=	yacc
 .if defined(%POSIX)
 YFLAGS		?=
 .else
 YFLAGS		?=	-d
 .endif
 
 .if defined(%POSIX)
 
 # Posix 1003.2 mandated rules
 #
 # Quoted directly from the Posix 1003.2 draft, only the macros
 # $@, $< and $* have been replaced by ${.TARGET}, ${.IMPSRC}, and
 # ${.PREFIX}, resp.
 
 # SINGLE SUFFIX RULES
 .c:
 	${CC} ${CFLAGS} ${LDFLAGS} -o ${.TARGET} ${.IMPSRC}
 
 .f:
 	${FC} ${FFLAGS} ${LDFLAGS} -o ${.TARGET} ${.IMPSRC}
 
 .sh:
 	cp -f ${.IMPSRC} ${.TARGET}
 	chmod a+x ${.TARGET}
 
 # DOUBLE SUFFIX RULES
 
 .c.o:
 	${CC} ${CFLAGS} -c ${.IMPSRC}
 
 .f.o:
 	${FC} ${FFLAGS} -c ${.IMPSRC}
 
 .y.o:
 	${YACC} ${YFLAGS} ${.IMPSRC}
 	${CC} ${CFLAGS} -c y.tab.c
 	rm -f y.tab.c
 	mv y.tab.o ${.TARGET}
 
 .l.o:
 	${LEX} ${LFLAGS} ${.IMPSRC}
 	${CC} ${CFLAGS} -c lex.yy.c
 	rm -f lex.yy.c
 	mv lex.yy.o ${.TARGET}
 
 .y.c:
 	${YACC} ${YFLAGS} ${.IMPSRC}
 	mv y.tab.c ${.TARGET}
 
 .l.c:
 	${LEX} ${LFLAGS} ${.IMPSRC}
 	mv lex.yy.c ${.TARGET}
 
 .c.a:
 	${CC} ${CFLAGS} -c ${.IMPSRC}
 	${AR} ${ARFLAGS} ${.TARGET} ${.PREFIX}.o
 	rm -f ${.PREFIX}.o
 
 .f.a:
 	${FC} ${FFLAGS} -c ${.IMPSRC}
 	${AR} ${ARFLAGS} ${.TARGET} ${.PREFIX}.o
 	rm -f ${.PREFIX}.o
 
 .else
 
 # non-Posix rule set
 
 .sh:
 	cp -f ${.IMPSRC} ${.TARGET}
 	chmod a+x ${.TARGET}
 
 .c.ln:
 	${LINT} ${LINTOBJFLAGS} ${CFLAGS:M-[DIU]*} ${.IMPSRC} || \
 	    touch ${.TARGET}
 
 .cc.ln .C.ln .cpp.ln .cxx.ln:
 	${LINT} ${LINTOBJFLAGS} ${CXXFLAGS:M-[DIU]*} ${.IMPSRC} || \
 	    touch ${.TARGET}
 
 .c:
 	${CC} ${CFLAGS} ${LDFLAGS} ${.IMPSRC} ${LDLIBS} -o ${.TARGET}
 	${CTFCONVERT_CMD}
 
 .c.o:
 	${CC} ${CFLAGS} -c ${.IMPSRC} -o ${.TARGET}
 	${CTFCONVERT_CMD}
 
 .cc .cpp .cxx .C:
 	${CXX} ${CXXFLAGS} ${LDFLAGS} ${.IMPSRC} ${LDLIBS} -o ${.TARGET}
 
 .cc.o .cpp.o .cxx.o .C.o:
 	${CXX} ${CXXFLAGS} -c ${.IMPSRC} -o ${.TARGET}
 
 .m.o:
 	${OBJC} ${OBJCFLAGS} -c ${.IMPSRC} -o ${.TARGET}
 	${CTFCONVERT_CMD}
 
 .p.o:
 	${PC} ${PFLAGS} -c ${.IMPSRC} -o ${.TARGET}
 	${CTFCONVERT_CMD}
 
 .e .r .F .f:
 	${FC} ${RFLAGS} ${EFLAGS} ${FFLAGS} ${LDFLAGS} ${.IMPSRC} ${LDLIBS} \
 	    -o ${.TARGET}
 
 .e.o .r.o .F.o .f.o:
 	${FC} ${RFLAGS} ${EFLAGS} ${FFLAGS} -c ${.IMPSRC} -o ${.TARGET}
 
 .S.o:
 	${CC:N${CCACHE_BIN}} ${CFLAGS} ${ACFLAGS} -c ${.IMPSRC} -o ${.TARGET}
 	${CTFCONVERT_CMD}
 
 .asm.o:
 	${CC:N${CCACHE_BIN}} -x assembler-with-cpp ${CFLAGS} ${ACFLAGS} -c ${.IMPSRC} \
 	    -o ${.TARGET}
 	${CTFCONVERT_CMD}
 
 .s.o:
 	${AS} ${AFLAGS} -o ${.TARGET} ${.IMPSRC}
 	${CTFCONVERT_CMD}
 
 # XXX not -j safe
 .y.o:
 	${YACC} ${YFLAGS} ${.IMPSRC}
 	${CC} ${CFLAGS} -c y.tab.c -o ${.TARGET}
 	rm -f y.tab.c
 	${CTFCONVERT_CMD}
 
 .l.o:
 	${LEX} -t ${LFLAGS} ${.IMPSRC} > ${.PREFIX}.tmp.c
 	${CC} ${CFLAGS} -c ${.PREFIX}.tmp.c -o ${.TARGET}
 	rm -f ${.PREFIX}.tmp.c
 	${CTFCONVERT_CMD}
 
 # XXX not -j safe
 .y.c:
 	${YACC} ${YFLAGS} ${.IMPSRC}
 	mv y.tab.c ${.TARGET}
 
 .l.c:
 	${LEX} -t ${LFLAGS} ${.IMPSRC} > ${.TARGET}
 
 .s.out .c.out .o.out:
 	${CC} ${CFLAGS} ${LDFLAGS} ${.IMPSRC} ${LDLIBS} -o ${.TARGET}
 	${CTFCONVERT_CMD}
 
 .f.out .F.out .r.out .e.out:
 	${FC} ${EFLAGS} ${RFLAGS} ${FFLAGS} ${LDFLAGS} ${.IMPSRC} \
 	    ${LDLIBS} -o ${.TARGET}
 	rm -f ${.PREFIX}.o
 	${CTFCONVERT_CMD}
 
 # XXX not -j safe
 .y.out:
 	${YACC} ${YFLAGS} ${.IMPSRC}
 	${CC} ${CFLAGS} ${LDFLAGS} y.tab.c ${LDLIBS} -ly -o ${.TARGET}
 	rm -f y.tab.c
 	${CTFCONVERT_CMD}
 
 .l.out:
 	${LEX} -t ${LFLAGS} ${.IMPSRC} > ${.PREFIX}.tmp.c
 	${CC} ${CFLAGS} ${LDFLAGS} ${.PREFIX}.tmp.c ${LDLIBS} -ll -o ${.TARGET}
 	rm -f ${.PREFIX}.tmp.c
 	${CTFCONVERT_CMD}
 
 # Pull in global settings.
 __MAKE_CONF?=/etc/make.conf
 .if exists(${__MAKE_CONF})
 .include "${__MAKE_CONF}"
 .endif
 
 # late include for customization
 .sinclude <local.sys.mk>
 
 .if defined(__MAKE_SHELL) && !empty(__MAKE_SHELL)
 SHELL=	${__MAKE_SHELL}
 .SHELL: path=${__MAKE_SHELL}
 .endif
 
 # Tell bmake to expand -V VAR by default
 .MAKE.EXPAND_VARIABLES= yes
 
 # Tell bmake the makefile preference
 .MAKE.MAKEFILE_PREFERENCE= BSDmakefile makefile Makefile
 
 # Tell bmake to always pass job tokens, regardless of target depending on
 # .MAKE or looking like ${MAKE}/${.MAKE}/$(MAKE)/$(.MAKE)/make.
 .MAKE.ALWAYS_PASS_JOB_QUEUE= yes
 
 # By default bmake does *not* use set -e
 # when running target scripts, this is a problem for many makefiles here.
 # So define a shell that will do what FreeBSD expects.
 .ifndef WITHOUT_SHELL_ERRCTL
 __MAKE_SHELL?=/bin/sh
 .SHELL: name=sh \
 	quiet="set -" echo="set -v" filter="set -" \
 	hasErrCtl=yes check="set -e" ignore="set +e" \
 	echoFlag=v errFlag=e \
 	path=${__MAKE_SHELL}
 .endif
 
 # Hack for ports compatibility. Historically, ports makefiles have
 # assumed they can examine MACHINE_CPU without including anything
 # because this was automatically included in sys.mk. For /usr/src,
 # this file has moved to being included from bsd.opts.mk. Until all
 # the ports files are modernized, and a reasonable transition
 # period has passed, include it while we're in a ports tree here
 # to preserve historic behavior.
 .if exists(${.CURDIR}/../../Mk/bsd.port.mk)
 .include <bsd.cpu.mk>
 .endif
 
 .endif # ! Posix
Index: head/tools/build/options/WITH_META_MODE
===================================================================
--- head/tools/build/options/WITH_META_MODE	(revision 301887)
+++ head/tools/build/options/WITH_META_MODE	(revision 301888)
@@ -1,47 +1,51 @@
 .\" $FreeBSD$
 Creates
 .Xr make 1
 meta files when building, which can provide a reliable incremental build when
 using
 .Xr filemon 4 .
 The meta file is created in the OBJDIR as
 .Pa target.meta .
 These meta files track the command ran, its output, and the current directory.
-When the
+The
 .Xr filemon 4
-module is loaded, any files used by the commands executed will be tracked as
+module is required unless
+.Va NO_FILEMON
+is defined.
+When the module is loaded, any files used by the commands executed will be
+tracked as
 dependencies for the target in its meta file.
 The target will be considered out-of-date and rebuilt if any of the following
 are true compared to the last build:
 .Bl -bullet -compact
 .It
 The command to execute changes.
 .It
 The current working directory changes.
 .It
 The target's meta file is missing.
 .It
 The target's meta file is missing filemon data when filemon is loaded
 and a previous run did not have it loaded.
 .It
 [requires
 .Xr filemon 4 ]
 Files read, executed or linked to are newer than the target.
 .It
 [requires
 .Xr filemon 4 ]
 Files read, written, executed or linked are missing.
 .El
 The meta files can also be useful for debugging.
 .Pp
 The build will hide commands ran unless
 .Va NO_SILENT
 is defined.
 .Pp
 The build operates as it normally would otherwise.
 This option originally invoked a different build system but that was renamed
 to
 .Va WITH_DIRDEPS_BUILD .
 .Pp
 Currently this also enforces
 .Va WITHOUT_SYSTEM_COMPILER .