xref: /src/build.sh

#! /usr/bin/env sh
#	$NetBSD: build.sh,v 1.255 2012/08/05 04:39:09 matt Exp $
#
# Copyright (c) 2001-2011 The NetBSD Foundation, Inc.
# All rights reserved.
#
# This code is derived from software contributed to The NetBSD Foundation
# by Todd Vierling and Luke Mewburn.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
#    notice, this list of conditions and the following disclaimer in the
#    documentation and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
# ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
# TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
# PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
# BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
# POSSIBILITY OF SUCH DAMAGE.
#
#
# Top level build wrapper, to build or cross-build NetBSD.
#

#
# {{{ Begin shell feature tests.
#
# We try to determine whether or not this script is being run under
# a shell that supports the features that we use.  If not, we try to
# re-exec the script under another shell.  If we can't find another
# suitable shell, then we print a message and exit.
#

errmsg=''		# error message, if not empty
shelltest=false		# if true, exit after testing the shell
re_exec_allowed=true	# if true, we may exec under another shell

# Parse special command line options in $1.  These special options are
# for internal use only, are not documented, and are not valid anywhere
# other than $1.
case "$1" in
"--shelltest")
    shelltest=true
    re_exec_allowed=false
    shift
    ;;
"--no-re-exec")
    re_exec_allowed=false
    shift
    ;;
esac

# Solaris /bin/sh, and other SVR4 shells, do not support "!".
# This is the first feature that we test, because subsequent
# tests use "!".
#
if test -z "$errmsg"; then
    if ( eval '! false' ) >/dev/null 2>&1 ; then
	:
    else
	errmsg='Shell does not support "!".'
    fi
fi

# Does the shell support functions?
#
if test -z "$errmsg"; then
    if ! (
	eval 'somefunction() { : ; }'
	) >/dev/null 2>&1
    then
	errmsg='Shell does not support functions.'
    fi
fi

# Does the shell support the "local" keyword for variables in functions?
#
# Local variables are not required by SUSv3, but some scripts run during
# the NetBSD build use them.
#
# ksh93 fails this test; it uses an incompatible syntax involving the
# keywords 'function' and 'typeset'.
#
if test -z "$errmsg"; then
    if ! (
	eval 'f() { local v=2; }; v=1; f && test x"$v" = x"1"'
	) >/dev/null 2>&1
    then
	errmsg='Shell does not support the "local" keyword in functions.'
    fi
fi

# Does the shell support ${var%suffix}, ${var#prefix}, and their variants?
#
# We don't bother testing for ${var+value}, ${var-value}, or their variants,
# since shells without those are sure to fail other tests too.
#
if test -z "$errmsg"; then
    if ! (
	eval 'var=a/b/c ;
	      test x"${var#*/};${var##*/};${var%/*};${var%%/*}" = \
		   x"b/c;c;a/b;a" ;'
	) >/dev/null 2>&1
    then
	errmsg='Shell does not support "${var%suffix}" or "${var#prefix}".'
    fi
fi

# Does the shell support IFS?
#
# zsh in normal mode (as opposed to "emulate sh" mode) fails this test.
#
if test -z "$errmsg"; then
    if ! (
	eval 'IFS=: ; v=":a b::c" ; set -- $v ; IFS=+ ;
		test x"$#;$1,$2,$3,$4;$*" = x"4;,a b,,c;+a b++c"'
	) >/dev/null 2>&1
    then
	errmsg='Shell does not support IFS word splitting.'
    fi
fi

# Does the shell support ${1+"$@"}?
#
# Some versions of zsh fail this test, even in "emulate sh" mode.
#
if test -z "$errmsg"; then
    if ! (
	eval 'set -- "a a a" "b b b"; set -- ${1+"$@"};
	      test x"$#;$1;$2" = x"2;a a a;b b b";'
	) >/dev/null 2>&1
    then
	errmsg='Shell does not support ${1+"$@"}.'
    fi
fi

# Does the shell support $(...) command substitution?
#
if test -z "$errmsg"; then
    if ! (
	eval 'var=$(echo abc); test x"$var" = x"abc"'
	) >/dev/null 2>&1
    then
	errmsg='Shell does not support "$(...)" command substitution.'
    fi
fi

# Does the shell support $(...) command substitution with
# unbalanced parentheses?
#
# Some shells known to fail this test are:  NetBSD /bin/ksh (as of 2009-12),
# bash-3.1, pdksh-5.2.14, zsh-4.2.7 in "emulate sh" mode.
#
if test -z "$errmsg"; then
    if ! (
	eval 'var=$(case x in x) echo abc;; esac); test x"$var" = x"abc"'
	) >/dev/null 2>&1
    then
	# XXX: This test is ignored because so many shells fail it; instead,
	#      the NetBSD build avoids using the problematic construct.
	: ignore 'Shell does not support "$(...)" with unbalanced ")".'
    fi
fi

# Does the shell support getopts or getopt?
#
if test -z "$errmsg"; then
    if ! (
	eval 'type getopts || type getopt'
	) >/dev/null 2>&1
    then
	errmsg='Shell does not support getopts or getopt.'
    fi
fi

#
# If shelltest is true, exit now, reporting whether or not the shell is good.
#
if $shelltest; then
    if test -n "$errmsg"; then
	echo >&2 "$0: $errmsg"
	exit 1
    else
	exit 0
    fi
fi

#
# If the shell was bad, try to exec a better shell, or report an error.
#
# Loops are broken by passing an extra "--no-re-exec" flag to the new
# instance of this script.
#
if test -n "$errmsg"; then
    if $re_exec_allowed; then
	for othershell in \
	    "${HOST_SH}" /usr/xpg4/bin/sh ksh ksh88 mksh pdksh bash dash
	    # NOTE: some shells known not to work are:
	    # any shell using csh syntax;
	    # Solaris /bin/sh (missing many modern features);
	    # ksh93 (incompatible syntax for local variables);
	    # zsh (many differences, unless run in compatibility mode).
	do
	    test -n "$othershell" || continue
	    if eval 'type "$othershell"' >/dev/null 2>&1 \
		&& "$othershell" "$0" --shelltest >/dev/null 2>&1
	    then
		cat <<EOF
$0: $errmsg
$0: Retrying under $othershell
EOF
		HOST_SH="$othershell"
		export HOST_SH
		exec $othershell "$0" --no-re-exec "$@" # avoid ${1+"$@"}
	    fi
	    # If HOST_SH was set, but failed the test above,
	    # then give up without trying any other shells.
	    test x"${othershell}" = x"${HOST_SH}" && break
	done
    fi

    #
    # If we get here, then the shell is bad, and we either could not
    # find a replacement, or were not allowed to try a replacement.
    #
    cat <<EOF
$0: $errmsg

The NetBSD build system requires a shell that supports modern POSIX
features, as well as the "local" keyword in functions (which is a
widely-implemented but non-standardised feature).

Please re-run this script under a suitable shell.  For example:

	/path/to/suitable/shell $0 ...

The above command will usually enable build.sh to automatically set
HOST_SH=/path/to/suitable/shell, but if that fails, then you may also
need to explicitly set the HOST_SH environment variable, as follows:

	HOST_SH=/path/to/suitable/shell
	export HOST_SH
	\${HOST_SH} $0 ...
EOF
    exit 1
fi

#
# }}} End shell feature tests.
#

progname=${0##*/}
toppid=$$
results=/dev/null
tab='	'
trap "exit 1" 1 2 3 15

bomb()
{
	cat >&2 <<ERRORMESSAGE

ERROR: $@
*** BUILD ABORTED ***
ERRORMESSAGE
	kill ${toppid}		# in case we were invoked from a subshell
	exit 1
}


statusmsg()
{
	${runcmd} echo "===> $@" | tee -a "${results}"
}

statusmsg2()
{
	local msg

	msg="${1}"
	shift
	case "${msg}" in
	????????????????*)	;;
	??????????*)		msg="${msg}      ";;
	?????*)			msg="${msg}           ";;
	*)			msg="${msg}                ";;
	esac
	case "${msg}" in
	?????????????????????*)	;;
	????????????????????)	msg="${msg} ";;
	???????????????????)	msg="${msg}  ";;
	??????????????????)	msg="${msg}   ";;
	?????????????????)	msg="${msg}    ";;
	????????????????)	msg="${msg}     ";;
	esac
	statusmsg "${msg}$*"
}

warning()
{
	statusmsg "Warning: $@"
}

# Find a program in the PATH, and print the result.  If not found,
# print a default.  If $2 is defined (even if it is an empty string),
# then that is the default; otherwise, $1 is used as the default.
find_in_PATH()
{
	local prog="$1"
	local result="${2-"$1"}"
	local oldIFS="${IFS}"
	local dir
	IFS=":"
	for dir in ${PATH}; do
		if [ -x "${dir}/${prog}" ]; then
			result="${dir}/${prog}"
			break
		fi
	done
	IFS="${oldIFS}"
	echo "${result}"
}

# Try to find a working POSIX shell, and set HOST_SH to refer to it.
# Assumes that uname_s, uname_m, and PWD have been set.
set_HOST_SH()
{
	# Even if ${HOST_SH} is already defined, we still do the
	# sanity checks at the end.

	# Solaris has /usr/xpg4/bin/sh.
	#
	[ -z "${HOST_SH}" ] && [ x"${uname_s}" = x"SunOS" ] && \
		[ -x /usr/xpg4/bin/sh ] && HOST_SH="/usr/xpg4/bin/sh"

	# Try to get the name of the shell that's running this script,
	# by parsing the output from "ps".  We assume that, if the host
	# system's ps command supports -o comm at all, it will do so
	# in the usual way: a one-line header followed by a one-line
	# result, possibly including trailing white space.  And if the
	# host system's ps command doesn't support -o comm, we assume
	# that we'll get an error message on stderr and nothing on
	# stdout.  (We don't try to use ps -o 'comm=' to suppress the
	# header line, because that is less widely supported.)
	#
	# If we get the wrong result here, the user can override it by
	# specifying HOST_SH in the environment.
	#
	[ -z "${HOST_SH}" ] && HOST_SH="$(
		(ps -p $$ -o comm | sed -ne "2s/[ ${tab}]*\$//p") 2>/dev/null )"

	# If nothing above worked, use "sh".  We will later find the
	# first directory in the PATH that has a "sh" program.
	#
	[ -z "${HOST_SH}" ] && HOST_SH="sh"

	# If the result so far is not an absolute path, try to prepend
	# PWD or search the PATH.
	#
	case "${HOST_SH}" in
	/*)	:
		;;
	*/*)	HOST_SH="${PWD}/${HOST_SH}"
		;;
	*)	HOST_SH="$(find_in_PATH "${HOST_SH}")"
		;;
	esac

	# If we don't have an absolute path by now, bomb.
	#
	case "${HOST_SH}" in
	/*)	:
		;;
	*)	bomb "HOST_SH=\"${HOST_SH}\" is not an absolute path."
		;;
	esac

	# If HOST_SH is not executable, bomb.
	#
	[ -x "${HOST_SH}" ] ||
	    bomb "HOST_SH=\"${HOST_SH}\" is not executable."

	# If HOST_SH fails tests, bomb.
	# ("$0" may be a path that is no longer valid, because we have
	# performed "cd $(dirname $0)", so don't use $0 here.)
	#
	"${HOST_SH}" build.sh --shelltest ||
	    bomb "HOST_SH=\"${HOST_SH}\" failed functionality tests."
}

# initdefaults --
# Set defaults before parsing command line options.
#
initdefaults()
{
	makeenv=
	makewrapper=
	makewrappermachine=
	runcmd=
	operations=
	removedirs=

	[ -d usr.bin/make ] || cd "$(dirname $0)"
	[ -d usr.bin/make ] ||
	    bomb "build.sh must be run from the top source level"
	[ -f share/mk/bsd.own.mk ] ||
	    bomb "src/share/mk is missing; please re-fetch the source tree"

	# Set various environment variables to known defaults,
	# to minimize (cross-)build problems observed "in the field".
	#
	# LC_ALL=C must be set before we try to parse the output from
	# any command.  Other variables are set (or unset) here, before
	# we parse command line arguments.
	#
	# These variables can be overridden via "-V var=value" if
	# you know what you are doing.
	#
	unsetmakeenv INFODIR
	unsetmakeenv LESSCHARSET
	unsetmakeenv MAKEFLAGS
	setmakeenv LC_ALL C

	# Find information about the build platform.  This should be
	# kept in sync with _HOST_OSNAME, _HOST_OSREL, and _HOST_ARCH
	# variables in share/mk/bsd.sys.mk.
	#
	# Note that "uname -p" is not part of POSIX, but we want uname_p
	# to be set to the host MACHINE_ARCH, if possible.  On systems
	# where "uname -p" fails, prints "unknown", or prints a string
	# that does not look like an identifier, fall back to using the
	# output from "uname -m" instead.
	#
	uname_s=$(uname -s 2>/dev/null)
	uname_r=$(uname -r 2>/dev/null)
	uname_m=$(uname -m 2>/dev/null)
	uname_p=$(uname -p 2>/dev/null || echo "unknown")
	case "${uname_p}" in
	''|unknown|*[^-_A-Za-z0-9]*) uname_p="${uname_m}" ;;
	esac

	id_u=$(id -u 2>/dev/null || /usr/xpg4/bin/id -u 2>/dev/null)

	# If $PWD is a valid name of the current directory, POSIX mandates
	# that pwd return it by default which causes problems in the
	# presence of symlinks.  Unsetting PWD is simpler than changing
	# every occurrence of pwd to use -P.
	#
	# XXX Except that doesn't work on Solaris. Or many Linuces.
	#
	unset PWD
	TOP=$(/bin/pwd -P 2>/dev/null || /bin/pwd 2>/dev/null)

	# The user can set HOST_SH in the environment, or we try to
	# guess an appropriate value.  Then we set several other
	# variables from HOST_SH.
	#
	set_HOST_SH
	setmakeenv HOST_SH "${HOST_SH}"
	setmakeenv BSHELL "${HOST_SH}"
	setmakeenv CONFIG_SHELL "${HOST_SH}"

	# Set defaults.
	#
	toolprefix=nb

	# Some systems have a small ARG_MAX.  -X prevents make(1) from
	# exporting variables in the environment redundantly.
	#
	case "${uname_s}" in
	Darwin | FreeBSD | CYGWIN*)
		MAKEFLAGS="-X ${MAKEFLAGS}"
		;;
	esac

	# do_{operation}=true if given operation is requested.
	#
	do_expertmode=false
	do_rebuildmake=false
	do_removedirs=false
	do_tools=false
	do_cleandir=false
	do_obj=false
	do_build=false
	do_distribution=false
	do_release=false
	do_kernel=false
	do_releasekernel=false
	do_modules=false
	do_installmodules=false
	do_install=false
	do_sets=false
	do_sourcesets=false
	do_syspkgs=false
	do_iso_image=false
	do_iso_image_source=false
	do_live_image=false
	do_install_image=false
	do_params=false
	do_rump=false

	# done_{operation}=true if given operation has been done.
	#
	done_rebuildmake=false

	# Create scratch directory
	#
	tmpdir="${TMPDIR-/tmp}/nbbuild$$"
	mkdir "${tmpdir}" || bomb "Cannot mkdir: ${tmpdir}"
	trap "cd /; rm -r -f \"${tmpdir}\"" 0
	results="${tmpdir}/build.sh.results"

	# Set source directories
	#
	setmakeenv NETBSDSRCDIR "${TOP}"

	# Make sure KERNOBJDIR is an absolute path if defined
	#
	case "${KERNOBJDIR}" in
	''|/*)	;;
	*)	KERNOBJDIR="${TOP}/${KERNOBJDIR}"
		setmakeenv KERNOBJDIR "${KERNOBJDIR}"
		;;
	esac

	# Find the version of NetBSD
	#
	DISTRIBVER="$(${HOST_SH} ${TOP}/sys/conf/osrelease.sh)"

	# Set the BUILDSEED to NetBSD-"N"
	#
	setmakeenv BUILDSEED "NetBSD-$(${HOST_SH} ${TOP}/sys/conf/osrelease.sh -m)"

	# Set MKARZERO to "yes"
	#
	setmakeenv MKARZERO "yes"

}

getarch()
{
	# Translate some MACHINE name aliases (known only to build.sh)
	# into proper MACHINE and MACHINE_ARCH names.  Save the alias
	# name in makewrappermachine.
	#
	case "${MACHINE}" in

	evbearm-e[bl])
		makewrappermachine=${MACHINE}
		# MACHINE_ARCH is "arm" or "armeb", not "armel"
		MACHINE_ARCH=earm${MACHINE##*-}
		MACHINE_ARCH=${MACHINE_ARCH%el}
		MACHINE=evbarm
		;;

	evbarm-e[bl])
		makewrappermachine=${MACHINE}
		# MACHINE_ARCH is "arm" or "armeb", not "armel"
		MACHINE_ARCH=arm${MACHINE##*-}
		MACHINE_ARCH=${MACHINE_ARCH%el}
		MACHINE=${MACHINE%-e[bl]}
		;;

	evbmips-e[bl]|sbmips-e[bl])
		makewrappermachine=${MACHINE}
		MACHINE_ARCH=mips${MACHINE##*-}
		MACHINE=${MACHINE%-e[bl]}
		;;

	evbmips64-e[bl]|sbmips64-e[bl])
		makewrappermachine=${MACHINE}
		MACHINE_ARCH=mips64${MACHINE##*-}
		MACHINE=${MACHINE%64-e[bl]}
		;;

	evbsh3-e[bl])
		makewrappermachine=${MACHINE}
		MACHINE_ARCH=sh3${MACHINE##*-}
		MACHINE=${MACHINE%-e[bl]}
		;;

	esac

	# Translate a MACHINE into a default MACHINE_ARCH.
	#
	case "${MACHINE}" in

	acorn26|acorn32|cats|hpcarm|iyonix|netwinder|shark|zaurus)
		MACHINE_ARCH=arm
		;;

	evbarm)		# unspecified MACHINE_ARCH gets LE
		MACHINE_ARCH=${MACHINE_ARCH:=arm}
		;;

	hp700)
		MACHINE_ARCH=hppa
		;;

	sun2)
		MACHINE_ARCH=m68000
		;;

	amiga|atari|cesfic|hp300|luna68k|mac68k|mvme68k|news68k|next68k|sun3|x68k)
		MACHINE_ARCH=m68k
		;;

	evbmips|sbmips)		# no default MACHINE_ARCH
		;;

	sgimips64)
		makewrappermachine=${MACHINE}
		MACHINE=${MACHINE%64}
		MACHINE_ARCH=mips64eb
		;;

	ews4800mips|mipsco|newsmips|sgimips|emips)
		MACHINE_ARCH=mipseb
		;;

	algor64|arc64|cobalt64|pmax64)
		makewrappermachine=${MACHINE}
		MACHINE=${MACHINE%64}
		MACHINE_ARCH=mips64el
		;;

	algor|arc|cobalt|hpcmips|pmax)
		MACHINE_ARCH=mipsel
		;;

	evbppc64|macppc64|ofppc64)
		makewrappermachine=${MACHINE}
		MACHINE=${MACHINE%64}
		MACHINE_ARCH=powerpc64
		;;

	amigappc|bebox|evbppc|ibmnws|macppc|mvmeppc|ofppc|prep|rs6000|sandpoint)
		MACHINE_ARCH=powerpc
		;;

	evbsh3)			# no default MACHINE_ARCH
		;;

	mmeye)
		MACHINE_ARCH=sh3eb
		;;

	dreamcast|hpcsh|landisk)
		MACHINE_ARCH=sh3el
		;;

	amd64)
		MACHINE_ARCH=x86_64
		;;

	alpha|i386|sparc|sparc64|vax|ia64)
		MACHINE_ARCH=${MACHINE}
		;;

	*)
		bomb "Unknown target MACHINE: ${MACHINE}"
		;;

	esac
}

validatearch()
{
	# Ensure that the MACHINE_ARCH exists (and is supported by build.sh).
	#
	case "${MACHINE_ARCH}" in

	alpha|arm|armeb|earm|earmeb|hppa|i386|m68000|m68k|mipse[bl]|mips64e[bl]|powerpc|powerpc64|sh3e[bl]|sparc|sparc64|vax|x86_64|ia64)
		;;

	"")
		bomb "No MACHINE_ARCH provided"
		;;

	*)
		bomb "Unknown target MACHINE_ARCH: ${MACHINE_ARCH}"
		;;

	esac

	# Determine valid MACHINE_ARCHs for MACHINE
	#
	case "${MACHINE}" in

	evbarm)
		arches="arm armeb earm earmeb"
		;;

	cats|iyonix|netwinder|shark|zaurus)
		arches="arm earm"
		;;

	algor|arc|cobalt|pmax)
		arches="mipsel mips64el"
		;;

	evbmips|sbmips)
		arches="mipseb mipsel mips64eb mips64el"
		;;

	sgimips)
		arches="mipseb mips64eb"
		;;

	evbsh3)
		arches="sh3eb sh3el"
		;;

	macppc|evbppc|ofppc)
		arches="powerpc powerpc64"
		;;
	*)
		oma="${MACHINE_ARCH}"
		getarch
		arches="${MACHINE_ARCH}"
		MACHINE_ARCH="${oma}"
		;;

	esac

	# Ensure that MACHINE_ARCH supports MACHINE
	#
	archok=false
	for a in ${arches}; do
		if [ "${a}" = "${MACHINE_ARCH}" ]; then
			archok=true
			break
		fi
	done
	${archok} ||
	    bomb "MACHINE_ARCH '${MACHINE_ARCH}' does not support MACHINE '${MACHINE}'"
}

# nobomb_getmakevar --
# Given the name of a make variable in $1, print make's idea of the
# value of that variable, or return 1 if there's an error.
#
nobomb_getmakevar()
{
	[ -x "${make}" ] || return 1
	"${make}" -m ${TOP}/share/mk -s -B -f- _x_ <<EOF || return 1
_x_:
	echo \${$1}
.include <bsd.prog.mk>
.include <bsd.kernobj.mk>
EOF
}

# bomb_getmakevar --
# Given the name of a make variable in $1, print make's idea of the
# value of that variable, or bomb if there's an error.
#
bomb_getmakevar()
{
	[ -x "${make}" ] || bomb "bomb_getmakevar $1: ${make} is not executable"
	nobomb_getmakevar "$1" || bomb "bomb_getmakevar $1: ${make} failed"
}

# getmakevar --
# Given the name of a make variable in $1, print make's idea of the
# value of that variable, or print a literal '$' followed by the
# variable name if ${make} is not executable.  This is intended for use in
# messages that need to be readable even if $make hasn't been built,
# such as when build.sh is run with the "-n" option.
#
getmakevar()
{
	if [ -x "${make}" ]; then
		bomb_getmakevar "$1"
	else
		echo "\$$1"
	fi
}

setmakeenv()
{
	eval "$1='$2'; export $1"
	makeenv="${makeenv} $1"
}

unsetmakeenv()
{
	eval "unset $1"
	makeenv="${makeenv} $1"
}

# Given a variable name in $1, modify the variable in place as follows:
# For each space-separated word in the variable, call resolvepath.
resolvepaths()
{
	local var="$1"
	local val
	eval val=\"\${${var}}\"
	local newval=''
	local word
	for word in ${val}; do
		resolvepath word
		newval="${newval}${newval:+ }${word}"
	done
	eval ${var}=\"\${newval}\"
}

# Given a variable name in $1, modify the variable in place as follows:
# Convert possibly-relative path to absolute path by prepending
# ${TOP} if necessary.  Also delete trailing "/", if any.
resolvepath()
{
	local var="$1"
	local val
	eval val=\"\${${var}}\"
	case "${val}" in
	/)
		;;
	/*)
		val="${val%/}"
		;;
	*)
		val="${TOP}/${val%/}"
		;;
	esac
	eval ${var}=\"\${val}\"
}

usage()
{
	if [ -n "$*" ]; then
		echo ""
		echo "${progname}: $*"
	fi
	cat <<_usage_

Usage: ${progname} [-EhnorUuxy] [-a arch] [-B buildid] [-C cdextras]
                [-D dest] [-j njob] [-M obj] [-m mach] [-N noisy]
                [-O obj] [-R release] [-S seed] [-T tools]
                [-V var=[value]] [-w wrapper] [-X x11src] [-Y extsrcsrc]
                [-Z var]
                operation [...]

 Build operations (all imply "obj" and "tools"):
    build               Run "make build".
    distribution        Run "make distribution" (includes DESTDIR/etc/ files).
    release             Run "make release" (includes kernels & distrib media).

 Other operations:
    help                Show this message and exit.
    makewrapper         Create ${toolprefix}make-\${MACHINE} wrapper and ${toolprefix}make.
                        Always performed.
    cleandir            Run "make cleandir".  [Default unless -u is used]
    obj                 Run "make obj".  [Default unless -o is used]
    tools               Build and install tools.
    install=idir        Run "make installworld" to \`idir' to install all sets
                        except \`etc'.  Useful after "distribution" or "release"
    kernel=conf         Build kernel with config file \`conf'
    releasekernel=conf  Install kernel built by kernel=conf to RELEASEDIR.
    installmodules=idir Run "make installmodules" to \`idir' to install all
                        kernel modules.
    modules             Build kernel modules.
    rumptest            Do a linktest for rump (for developers).
    sets                Create binary sets in
                        RELEASEDIR/RELEASEMACHINEDIR/binary/sets.
                        DESTDIR should be populated beforehand.
    sourcesets          Create source sets in RELEASEDIR/source/sets.
    syspkgs             Create syspkgs in
                        RELEASEDIR/RELEASEMACHINEDIR/binary/syspkgs.
    iso-image           Create CD-ROM image in RELEASEDIR/iso.
    iso-image-source    Create CD-ROM image with source in RELEASEDIR/iso.
    live-image          Create bootable live image in
                        RELEASEDIR/RELEASEMACHINEDIR/installation/liveimage.
    install-image       Create bootable installation image in
                        RELEASEDIR/RELEASEMACHINEDIR/installation/installimage.
    params              Display various make(1) parameters.

 Options:
    -a arch        Set MACHINE_ARCH to arch.  [Default: deduced from MACHINE]
    -B buildid     Set BUILDID to buildid.
    -C cdextras    Append cdextras to CDEXTRA variable for inclusion on CD-ROM.
    -D dest        Set DESTDIR to dest.  [Default: destdir.MACHINE]
    -E             Set "expert" mode; disables various safety checks.
                   Should not be used without expert knowledge of the build system.
    -h             Print this help message.
    -j njob        Run up to njob jobs in parallel; see make(1) -j.
    -M obj         Set obj root directory to obj; sets MAKEOBJDIRPREFIX.
                   Unsets MAKEOBJDIR.
    -m mach        Set MACHINE to mach; not required if NetBSD native.
    -N noisy       Set the noisyness (MAKEVERBOSE) level of the build:
                       0   Minimal output ("quiet")
                       1   Describe what is occurring
                       2   Describe what is occurring and echo the actual command
                       3   Ignore the effect of the "@" prefix in make commands
                       4   Trace shell commands using the shell's -x flag
                   [Default: 2]
    -n             Show commands that would be executed, but do not execute them.
    -O obj         Set obj root directory to obj; sets a MAKEOBJDIR pattern.
                   Unsets MAKEOBJDIRPREFIX.
    -o             Set MKOBJDIRS=no; do not create objdirs at start of build.
    -R release     Set RELEASEDIR to release.  [Default: releasedir]
    -r             Remove contents of TOOLDIR and DESTDIR before building.
    -S seed        Set BUILDSEED to seed.  [Default: NetBSD-majorversion]
    -T tools       Set TOOLDIR to tools.  If unset, and TOOLDIR is not set in
                   the environment, ${toolprefix}make will be (re)built
                   unconditionally.
    -U             Set MKUNPRIVED=yes; build without requiring root privileges,
                   install from an UNPRIVED build with proper file permissions.
    -u             Set MKUPDATE=yes; do not run "make cleandir" first.
                   Without this, everything is rebuilt, including the tools.
    -V var=[value] Set variable \`var' to \`value'.
    -w wrapper     Create ${toolprefix}make script as wrapper.
                   [Default: \${TOOLDIR}/bin/${toolprefix}make-\${MACHINE}]
    -X x11src      Set X11SRCDIR to x11src.  [Default: /usr/xsrc]
    -x             Set MKX11=yes; build X11 from X11SRCDIR
    -Y extsrcsrc   Set EXTSRCSRCDIR to extsrcsrc.  [Default: /usr/extsrc]
    -y             Set MKEXTSRC=yes; build extsrc from EXTSRCSRCDIR
    -Z var         Unset ("zap") variable \`var'.

_usage_
	exit 1
}

parseoptions()
{
	opts='a:B:C:D:Ehj:M:m:N:nO:oR:rS:T:UuV:w:X:xY:yZ:'
	opt_a=no

	if type getopts >/dev/null 2>&1; then
		# Use POSIX getopts.
		#
		getoptcmd='getopts ${opts} opt && opt=-${opt}'
		optargcmd=':'
		optremcmd='shift $((${OPTIND} -1))'
	else
		type getopt >/dev/null 2>&1 ||
		    bomb "Shell does not support getopts or getopt"

		# Use old-style getopt(1) (doesn't handle whitespace in args).
		#
		args="$(getopt ${opts} $*)"
		[ $? = 0 ] || usage
		set -- ${args}

		getoptcmd='[ $# -gt 0 ] && opt="$1" && shift'
		optargcmd='OPTARG="$1"; shift'
		optremcmd=':'
	fi

	# Parse command line options.
	#
	while eval ${getoptcmd}; do
		case ${opt} in

		-a)
			eval ${optargcmd}
			MACHINE_ARCH=${OPTARG}
			opt_a=yes
			;;

		-B)
			eval ${optargcmd}
			BUILDID=${OPTARG}
			;;

		-C)
			eval ${optargcmd}; resolvepaths OPTARG
			CDEXTRA="${CDEXTRA}${CDEXTRA:+ }${OPTARG}"
			;;

		-D)
			eval ${optargcmd}; resolvepath OPTARG
			setmakeenv DESTDIR "${OPTARG}"
			;;

		-E)
			do_expertmode=true
			;;

		-j)
			eval ${optargcmd}
			parallel="-j ${OPTARG}"
			;;

		-M)
			eval ${optargcmd}; resolvepath OPTARG
			case "${OPTARG}" in
			\$*)	usage "-M argument must not begin with '\$'"
				;;
			*\$*)	# can use resolvepath, but can't set TOP_objdir
				resolvepath OPTARG
				;;
			*)	resolvepath OPTARG
				TOP_objdir="${OPTARG}${TOP}"
				;;
			esac
			unsetmakeenv MAKEOBJDIR
			setmakeenv MAKEOBJDIRPREFIX "${OPTARG}"
			;;

			# -m overrides MACHINE_ARCH unless "-a" is specified
		-m)
			eval ${optargcmd}
			MACHINE="${OPTARG}"
			[ "${opt_a}" != "yes" ] && getarch
			;;

		-N)
			eval ${optargcmd}
			case "${OPTARG}" in
			0|1|2|3|4)
				setmakeenv MAKEVERBOSE "${OPTARG}"
				;;
			*)
				usage "'${OPTARG}' is not a valid value for -N"
				;;
			esac
			;;

		-n)
			runcmd=echo
			;;

		-O)
			eval ${optargcmd}
			case "${OPTARG}" in
			*\$*)	usage "-O argument must not contain '\$'"
				;;
			*)	resolvepath OPTARG
				TOP_objdir="${OPTARG}"
				;;
			esac
			unsetmakeenv MAKEOBJDIRPREFIX
			setmakeenv MAKEOBJDIR "\${.CURDIR:C,^$TOP,$OPTARG,}"
			;;

		-o)
			MKOBJDIRS=no
			;;

		-R)
			eval ${optargcmd}; resolvepath OPTARG
			setmakeenv RELEASEDIR "${OPTARG}"
			;;

		-r)
			do_removedirs=true
			do_rebuildmake=true
			;;

		-S)
			eval ${optargcmd}
			setmakeenv BUILDSEED "${OPTARG}"
			;;

		-T)
			eval ${optargcmd}; resolvepath OPTARG
			TOOLDIR="${OPTARG}"
			export TOOLDIR
			;;

		-U)
			setmakeenv MKUNPRIVED yes
			;;

		-u)
			setmakeenv MKUPDATE yes
			;;

		-V)
			eval ${optargcmd}
			case "${OPTARG}" in
		    # XXX: consider restricting which variables can be changed?
			[a-zA-Z_][a-zA-Z_0-9]*=*)
				setmakeenv "${OPTARG%%=*}" "${OPTARG#*=}"
				;;
			*)
				usage "-V argument must be of the form 'var=[value]'"
				;;
			esac
			;;

		-w)
			eval ${optargcmd}; resolvepath OPTARG
			makewrapper="${OPTARG}"
			;;

		-X)
			eval ${optargcmd}; resolvepath OPTARG
			setmakeenv X11SRCDIR "${OPTARG}"
			;;

		-x)
			setmakeenv MKX11 yes
			;;

		-Y)
			eval ${optargcmd}; resolvepath OPTARG
			setmakeenv EXTSRCSRCDIR "${OPTARG}"
			;;

		-y)
			setmakeenv MKEXTSRC yes
			;;

		-Z)
			eval ${optargcmd}
		    # XXX: consider restricting which variables can be unset?
			unsetmakeenv "${OPTARG}"
			;;

		--)
			break
			;;

		-'?'|-h)
			usage
			;;

		esac
	done

	# Validate operations.
	#
	eval ${optremcmd}
	while [ $# -gt 0 ]; do
		op=$1; shift
		operations="${operations} ${op}"

		case "${op}" in

		help)
			usage
			;;

		makewrapper|cleandir|obj|tools|build|distribution|release|sets|sourcesets|syspkgs|params)
			;;

		iso-image)
			op=iso_image	# used as part of a variable name
			;;

		iso-image-source)
			op=iso_image_source   # used as part of a variable name
			;;

		live-image)
			op=live_image	# used as part of a variable name
			;;

		install-image)
			op=install_image # used as part of a variable name
			;;

		kernel=*|releasekernel=*)
			arg=${op#*=}
			op=${op%%=*}
			[ -n "${arg}" ] ||
			    bomb "Must supply a kernel name with \`${op}=...'"
			;;

		modules)
			op=modules
			;;

		install=*|installmodules=*)
			arg=${op#*=}
			op=${op%%=*}
			[ -n "${arg}" ] ||
			    bomb "Must supply a directory with \`install=...'"
			;;

		rump|rumptest)
			op=${op}
			;;

		*)
			usage "Unknown operation \`${op}'"
			;;

		esac
		eval do_${op}=true
	done
	[ -n "${operations}" ] || usage "Missing operation to perform."

	# Set up MACHINE*.  On a NetBSD host, these are allowed to be unset.
	#
	if [ -z "${MACHINE}" ]; then
		[ "${uname_s}" = "NetBSD" ] ||
		    bomb "MACHINE must be set, or -m must be used, for cross builds."
		MACHINE=${uname_m}
	fi
	[ -n "${MACHINE_ARCH}" ] || getarch
	validatearch

	# Set up default make(1) environment.
	#
	makeenv="${makeenv} TOOLDIR MACHINE MACHINE_ARCH MAKEFLAGS"
	[ -z "${BUILDID}" ] || makeenv="${makeenv} BUILDID"
	MAKEFLAGS="-de -m ${TOP}/share/mk ${MAKEFLAGS}"
	MAKEFLAGS="${MAKEFLAGS} MKOBJDIRS=${MKOBJDIRS-yes}"
	export MAKEFLAGS MACHINE MACHINE_ARCH
}

# sanitycheck --
# Sanity check after parsing command line options, before rebuildmake.
#
sanitycheck()
{
	# If the PATH contains any non-absolute components (including,
	# but not limited to, "." or ""), then complain.  As an exception,
	# allow "" or "." as the last component of the PATH.  This is fatal
	# if expert mode is not in effect.
	#
	local path="${PATH}"
	path="${path%:}"	# delete trailing ":"
	path="${path%:.}"	# delete trailing ":."
	case ":${path}:/" in
	*:[!/]*)
		if ${do_expertmode}; then
			warning "PATH contains non-absolute components"
		else
			bomb "PATH environment variable must not" \
			     "contain non-absolute components"
		fi
		;;
	esac
}

# print_tooldir_make --
# Try to find and print a path to an existing
# ${TOOLDIR}/bin/${toolprefix}make, for use by rebuildmake() before a
# new version of ${toolprefix}make has been built.
#
# * If TOOLDIR was set in the environment or on the command line, use
#   that value.
# * Otherwise try to guess what TOOLDIR would be if not overridden by
#   /etc/mk.conf, and check whether the resulting directory contains
#   a copy of ${toolprefix}make (this should work for everybody who
#   doesn't override TOOLDIR via /etc/mk.conf);
# * Failing that, search for ${toolprefix}make, nbmake, bmake, or make,
#   in the PATH (this might accidentally find a version of make that
#   does not understand the syntax used by NetBSD make, and that will
#   lead to failure in the next step);
# * If a copy of make was found above, try to use it with
#   nobomb_getmakevar to find the correct value for TOOLDIR, and believe the
#   result only if it's a directory that already exists;
# * If a value of TOOLDIR was found above, and if
#   ${TOOLDIR}/bin/${toolprefix}make exists, print that value.
#
print_tooldir_make()
{
	local possible_TOP_OBJ
	local possible_TOOLDIR
	local possible_make
	local tooldir_make

	if [ -n "${TOOLDIR}" ]; then
		echo "${TOOLDIR}/bin/${toolprefix}make"
		return 0
	fi

	# Set host_ostype to something like "NetBSD-4.5.6-i386".  This
	# is intended to match the HOST_OSTYPE variable in <bsd.own.mk>.
	#
	local host_ostype="${uname_s}-$(
		echo "${uname_r}" | sed -e 's/([^)]*)//g' -e 's/ /_/g'
		)-$(
		echo "${uname_p}" | sed -e 's/([^)]*)//g' -e 's/ /_/g'
		)"

	# Look in a few potential locations for
	# ${possible_TOOLDIR}/bin/${toolprefix}make.
	# If we find it, then set possible_make.
	#
	# In the usual case (without interference from environment
	# variables or /etc/mk.conf), <bsd.own.mk> should set TOOLDIR to
	# "${_SRC_TOP_OBJ_}/tooldir.${host_ostype}".
	#
	# In practice it's difficult to figure out the correct value
	# for _SRC_TOP_OBJ_.  In the easiest case, when the -M or -O
	# options were passed to build.sh, then ${TOP_objdir} will be
	# the correct value.  We also try a few other possibilities, but
	# we do not replicate all the logic of <bsd.obj.mk>.
	#
	for possible_TOP_OBJ in \
		"${TOP_objdir}" \
		"${MAKEOBJDIRPREFIX:+${MAKEOBJDIRPREFIX}${TOP}}" \
		"${TOP}" \
		"${TOP}/obj" \
		"${TOP}/obj.${MACHINE}"
	do
		[ -n "${possible_TOP_OBJ}" ] || continue
		possible_TOOLDIR="${possible_TOP_OBJ}/tooldir.${host_ostype}"
		possible_make="${possible_TOOLDIR}/bin/${toolprefix}make"
		if [ -x "${possible_make}" ]; then
			break
		else
			unset possible_make
		fi
	done

	# If the above didn't work, search the PATH for a suitable
	# ${toolprefix}make, nbmake, bmake, or make.
	#
	: ${possible_make:=$(find_in_PATH ${toolprefix}make '')}
	: ${possible_make:=$(find_in_PATH nbmake '')}
	: ${possible_make:=$(find_in_PATH bmake '')}
	: ${possible_make:=$(find_in_PATH make '')}

	# At this point, we don't care whether possible_make is in the
	# correct TOOLDIR or not; we simply want it to be usable by
	# getmakevar to help us find the correct TOOLDIR.
	#
	# Use ${possible_make} with nobomb_getmakevar to try to find
	# the value of TOOLDIR.  Believe the result only if it's
	# a directory that already exists and contains bin/${toolprefix}make.
	#
	if [ -x "${possible_make}" ]; then
		possible_TOOLDIR="$(
			make="${possible_make}" \
			nobomb_getmakevar TOOLDIR 2>/dev/null
			)"
		if [ $? = 0 ] && [ -n "${possible_TOOLDIR}" ] \
		    && [ -d "${possible_TOOLDIR}" ];
		then
			tooldir_make="${possible_TOOLDIR}/bin/${toolprefix}make"
			if [ -x "${tooldir_make}" ]; then
				echo "${tooldir_make}"
				return 0
			fi
		fi
	fi
	return 1
}

# rebuildmake --
# Rebuild nbmake in a temporary directory if necessary.  Sets $make
# to a path to the nbmake executable.  Sets done_rebuildmake=true
# if nbmake was rebuilt.
#
# There is a cyclic dependency between building nbmake and choosing
# TOOLDIR: TOOLDIR may be affected by settings in /etc/mk.conf, so we
# would like to use getmakevar to get the value of TOOLDIR; but we can't
# use getmakevar before we have an up to date version of nbmake; we
# might already have an up to date version of nbmake in TOOLDIR, but we
# don't yet know where TOOLDIR is.
#
# The default value of TOOLDIR also depends on the location of the top
# level object directory, so $(getmakevar TOOLDIR) invoked before or
# after making the top level object directory may produce different
# results.
#
# Strictly speaking, we should do the following:
#
#    1. build a new version of nbmake in a temporary directory;
#    2. use the temporary nbmake to create the top level obj directory;
#    3. use $(getmakevar TOOLDIR) with the temporary nbmake to
#       get the corect value of TOOLDIR;
#    4. move the temporary nbmake to ${TOOLDIR}/bin/nbmake.
#
# However, people don't like building nbmake unnecessarily if their
# TOOLDIR has not changed since an earlier build.  We try to avoid
# rebuilding a temporary version of nbmake by taking some shortcuts to
# guess a value for TOOLDIR, looking for an existing version of nbmake
# in that TOOLDIR, and checking whether that nbmake is newer than the
# sources used to build it.
#
rebuildmake()
{
	make="$(print_tooldir_make)"
	if [ -n "${make}" ] && [ -x "${make}" ]; then
		for f in usr.bin/make/*.[ch] usr.bin/make/lst.lib/*.[ch]; do
			if [ "${f}" -nt "${make}" ]; then
				statusmsg "${make} outdated" \
					"(older than ${f}), needs building."
				do_rebuildmake=true
				break
			fi
		done
	else
		statusmsg "No \$TOOLDIR/bin/${toolprefix}make, needs building."
		do_rebuildmake=true
	fi

	# Build bootstrap ${toolprefix}make if needed.
	if ${do_rebuildmake}; then
		statusmsg "Bootstrapping ${toolprefix}make"
		${runcmd} cd "${tmpdir}"
		${runcmd} env CC="${HOST_CC-cc}" CPPFLAGS="${HOST_CPPFLAGS}" \
			CFLAGS="${HOST_CFLAGS--O}" LDFLAGS="${HOST_LDFLAGS}" \
			${HOST_SH} "${TOP}/tools/make/configure" ||
		    bomb "Configure of ${toolprefix}make failed"
		${runcmd} ${HOST_SH} buildmake.sh ||
		    bomb "Build of ${toolprefix}make failed"
		make="${tmpdir}/${toolprefix}make"
		${runcmd} cd "${TOP}"
		${runcmd} rm -f usr.bin/make/*.o usr.bin/make/lst.lib/*.o
		done_rebuildmake=true
	fi
}

# validatemakeparams --
# Perform some late sanity checks, after rebuildmake,
# but before createmakewrapper or any real work.
#
# Also create the top-level obj directory.
#
validatemakeparams()
{
	if [ "${runcmd}" = "echo" ]; then
		TOOLCHAIN_MISSING=no
		EXTERNAL_TOOLCHAIN=""
	else
		TOOLCHAIN_MISSING=$(bomb_getmakevar TOOLCHAIN_MISSING)
		EXTERNAL_TOOLCHAIN=$(bomb_getmakevar EXTERNAL_TOOLCHAIN)
	fi
	if [ "${TOOLCHAIN_MISSING}" = "yes" ] && \
	   [ -z "${EXTERNAL_TOOLCHAIN}" ]; then
		${runcmd} echo "ERROR: build.sh (in-tree cross-toolchain) is not yet available for"
		${runcmd} echo "	MACHINE:      ${MACHINE}"
		${runcmd} echo "	MACHINE_ARCH: ${MACHINE_ARCH}"
		${runcmd} echo ""
		${runcmd} echo "All builds for this platform should be done via a traditional make"
		${runcmd} echo "If you wish to use an external cross-toolchain, set"
		${runcmd} echo "	EXTERNAL_TOOLCHAIN=<path to toolchain root>"
		${runcmd} echo "in either the environment or mk.conf and rerun"
		${runcmd} echo "	${progname} $*"
		exit 1
	fi

	# Normalise MKOBJDIRS, MKUNPRIVED, and MKUPDATE
	# These may be set as build.sh options or in "mk.conf".
	# Don't export them as they're only used for tests in build.sh.
	#
	MKOBJDIRS=$(getmakevar MKOBJDIRS)
	MKUNPRIVED=$(getmakevar MKUNPRIVED)
	MKUPDATE=$(getmakevar MKUPDATE)

	if [ "${MKOBJDIRS}" != "no" ]; then
		# Create the top-level object directory.
		#
		# "make obj NOSUBDIR=" can handle most cases, but it
		# can't handle the case where MAKEOBJDIRPREFIX is set
		# while the corresponding directory does not exist
		# (rules in <bsd.obj.mk> would abort the build).  We
		# therefore have to handle the MAKEOBJDIRPREFIX case
		# without invoking "make obj".  The MAKEOBJDIR case
		# could be handled either way, but we choose to handle
		# it similarly to MAKEOBJDIRPREFIX.
		#
		if [ -n "${TOP_obj}" ]; then
			# It must have been set by the "-M" or "-O"
			# command line options, so there's no need to
			# use getmakevar
			:
		elif [ -n "$MAKEOBJDIRPREFIX" ]; then
			TOP_obj="$(getmakevar MAKEOBJDIRPREFIX)${TOP}"
		elif [ -n "$MAKEOBJDIR" ]; then
			TOP_obj="$(getmakevar MAKEOBJDIR)"
		fi
		if [ -n "$TOP_obj" ]; then
			${runcmd} mkdir -p "${TOP_obj}" ||
			    bomb "Can't create top level object directory" \
					"${TOP_obj}"
		else
			${runcmd} "${make}" -m ${TOP}/share/mk obj NOSUBDIR= ||
			    bomb "Can't create top level object directory" \
					"using make obj"
		fi

		# make obj in tools to ensure that the objdir for "tools"
		# is available.
		#
		${runcmd} cd tools
		${runcmd} "${make}" -m ${TOP}/share/mk obj NOSUBDIR= ||
		    bomb "Failed to make obj in tools"
		${runcmd} cd "${TOP}"
	fi

	# Find TOOLDIR, DESTDIR, and RELEASEDIR, according to getmakevar,
	# and bomb if they have changed from the values we had from the
	# command line or environment.
	#
	# This must be done after creating the top-level object directory.
	#
	for var in TOOLDIR DESTDIR RELEASEDIR
	do
		eval oldval=\"\$${var}\"
		newval="$(getmakevar $var)"
		if ! $do_expertmode; then
			: ${_SRC_TOP_OBJ_:=$(getmakevar _SRC_TOP_OBJ_)}
			case "$var" in
			DESTDIR)
				: ${newval:=${_SRC_TOP_OBJ_}/destdir.${MACHINE}}
				makeenv="${makeenv} DESTDIR"
				;;
			RELEASEDIR)
				: ${newval:=${_SRC_TOP_OBJ_}/releasedir}
				makeenv="${makeenv} RELEASEDIR"
				;;
			esac
		fi
		if [ -n "$oldval" ] && [ "$oldval" != "$newval" ]; then
			bomb "Value of ${var} has changed" \
				"(was \"${oldval}\", now \"${newval}\")"
		fi
		eval ${var}=\"\${newval}\"
		eval export ${var}
		statusmsg2 "${var} path:" "${newval}"
	done

	# RELEASEMACHINEDIR is just a subdir name, e.g. "i386".
	RELEASEMACHINEDIR=$(getmakevar RELEASEMACHINEDIR)

	# Check validity of TOOLDIR and DESTDIR.
	#
	if [ -z "${TOOLDIR}" ] || [ "${TOOLDIR}" = "/" ]; then
		bomb "TOOLDIR '${TOOLDIR}' invalid"
	fi
	removedirs="${TOOLDIR}"

	if [ -z "${DESTDIR}" ] || [ "${DESTDIR}" = "/" ]; then
		if ${do_build} || ${do_distribution} || ${do_release}; then
			if ! ${do_build} || \
			   [ "${uname_s}" != "NetBSD" ] || \
			   [ "${uname_m}" != "${MACHINE}" ]; then
				bomb "DESTDIR must != / for cross builds, or ${progname} 'distribution' or 'release'."
			fi
			if ! ${do_expertmode}; then
				bomb "DESTDIR must != / for non -E (expert) builds"
			fi
			statusmsg "WARNING: Building to /, in expert mode."
			statusmsg "         This may cause your system to break!  Reasons include:"
			statusmsg "            - your kernel is not up to date"
			statusmsg "            - the libraries or toolchain have changed"
			statusmsg "         YOU HAVE BEEN WARNED!"
		fi
	else
		removedirs="${removedirs} ${DESTDIR}"
	fi
	if ${do_build} || ${do_distribution} || ${do_release}; then
		if ! ${do_expertmode} && \
		    [ "$id_u" -ne 0 ] && \
		    [ "${MKUNPRIVED}" = "no" ] ; then
			bomb "-U or -E must be set for build as an unprivileged user."
		fi
	fi
	if ${do_releasekernel} && [ -z "${RELEASEDIR}" ]; then
		bomb "Must set RELEASEDIR with \`releasekernel=...'"
	fi

	# Install as non-root is a bad idea.
	#
	if ${do_install} && [ "$id_u" -ne 0 ] ; then
		if ${do_expertmode}; then
			warning "Will install as an unprivileged user."
		else
			bomb "-E must be set for install as an unprivileged user."
		fi
	fi

	# If a previous build.sh run used -U (and therefore created a
	# METALOG file), then most subsequent build.sh runs must also
	# use -U.  If DESTDIR is about to be removed, then don't perform
	# this check.
	#
	case "${do_removedirs} ${removedirs} " in
	true*" ${DESTDIR} "*)
		# DESTDIR is about to be removed
		;;
	*)
		if ( ${do_build} || ${do_distribution} || ${do_release} || \
		    ${do_install} ) && \
		    [ -e "${DESTDIR}/METALOG" ] && \
		    [ "${MKUNPRIVED}" = "no" ] ; then
			if $do_expertmode; then
				warning "A previous build.sh run specified -U."
			else
				bomb "A previous build.sh run specified -U; you must specify it again now."
			fi
		fi
		;;
	esac

	# live-image and install-image targets require binary sets
	# (actually DESTDIR/etc/mtree/set.* files) built with MKUNPRIVED.
	# If release operation is specified with live-image or install-image,
	# the release op should be performed with -U for later image ops.
	#
	if ${do_release} && ( ${do_live_image} || ${do_install_image} ) && \
	    [ "${MKUNPRIVED}" = "no" ] ; then
		bomb "-U must be specified on building release to create images later."
	fi
}


createmakewrapper()
{
	# Remove the target directories.
	#
	if ${do_removedirs}; then
		for f in ${removedirs}; do
			statusmsg "Removing ${f}"
			${runcmd} rm -r -f "${f}"
		done
	fi

	# Recreate $TOOLDIR.
	#
	${runcmd} mkdir -p "${TOOLDIR}/bin" ||
	    bomb "mkdir of '${TOOLDIR}/bin' failed"

	# If we did not previously rebuild ${toolprefix}make, then
	# check whether $make is still valid and the same as the output
	# from print_tooldir_make.  If not, then rebuild make now.  A
	# possible reason for this being necessary is that the actual
	# value of TOOLDIR might be different from the value guessed
	# before the top level obj dir was created.
	#
	if ! ${done_rebuildmake} && \
	    ( [ ! -x "$make" ] || [ "$make" != "$(print_tooldir_make)" ] )
	then
		rebuildmake
	fi

	# Install ${toolprefix}make if it was built.
	#
	if ${done_rebuildmake}; then
		${runcmd} rm -f "${TOOLDIR}/bin/${toolprefix}make"
		${runcmd} cp "${make}" "${TOOLDIR}/bin/${toolprefix}make" ||
		    bomb "Failed to install \$TOOLDIR/bin/${toolprefix}make"
		make="${TOOLDIR}/bin/${toolprefix}make"
		statusmsg "Created ${make}"
	fi

	# Build a ${toolprefix}make wrapper script, usable by hand as
	# well as by build.sh.
	#
	if [ -z "${makewrapper}" ]; then
		makewrapper="${TOOLDIR}/bin/${toolprefix}make-${makewrappermachine:-${MACHINE}}"
		[ -z "${BUILDID}" ] || makewrapper="${makewrapper}-${BUILDID}"
	fi

	${runcmd} rm -f "${makewrapper}"
	if [ "${runcmd}" = "echo" ]; then
		echo 'cat <<EOF >'${makewrapper}
		makewrapout=
	else
		makewrapout=">>\${makewrapper}"
	fi

	case "${KSH_VERSION:-${SH_VERSION}}" in
	*PD\ KSH*|*MIRBSD\ KSH*)
		set +o braceexpand
		;;
	esac

	eval cat <<EOF ${makewrapout}
#! ${HOST_SH}
# Set proper variables to allow easy "make" building of a NetBSD subtree.
# Generated from:  \$NetBSD: build.sh,v 1.255 2012/08/05 04:39:09 matt Exp $
# with these arguments: ${_args}
#

EOF
	{
		for f in ${makeenv}; do
			if eval "[ -z \"\${$f}\" -a \"\${${f}-X}\" = \"X\" ]"; then
				eval echo "unset ${f}"
			else
				eval echo "${f}=\'\$$(echo ${f})\'\;\ export\ ${f}"
			fi
		done

		eval cat <<EOF
MAKEWRAPPERMACHINE=${makewrappermachine:-${MACHINE}}; export MAKEWRAPPERMACHINE
USETOOLS=yes; export USETOOLS
EOF
	} | eval sort -u "${makewrapout}"
	eval cat <<EOF "${makewrapout}"

exec "\${TOOLDIR}/bin/${toolprefix}make" \${1+"\$@"}
EOF
	[ "${runcmd}" = "echo" ] && echo EOF
	${runcmd} chmod +x "${makewrapper}"
	statusmsg2 "Updated makewrapper:" "${makewrapper}"
}

make_in_dir()
{
	dir="$1"
	op="$2"
	${runcmd} cd "${dir}" ||
	    bomb "Failed to cd to \"${dir}\""
	${runcmd} "${makewrapper}" ${parallel} ${op} ||
	    bomb "Failed to make ${op} in \"${dir}\""
	${runcmd} cd "${TOP}" ||
	    bomb "Failed to cd back to \"${TOP}\""
}

buildtools()
{
	if [ "${MKOBJDIRS}" != "no" ]; then
		${runcmd} "${makewrapper}" ${parallel} obj-tools ||
		    bomb "Failed to make obj-tools"
	fi
	if [ "${MKUPDATE}" = "no" ]; then
		make_in_dir tools cleandir
	fi
	make_in_dir tools dependall
	make_in_dir tools install
	statusmsg "Tools built to ${TOOLDIR}"
}

getkernelconf()
{
	kernelconf="$1"
	if [ "${MKOBJDIRS}" != "no" ]; then
		# The correct value of KERNOBJDIR might
		# depend on a prior "make obj" in
		# ${KERNSRCDIR}/${KERNARCHDIR}/compile.
		#
		KERNSRCDIR="$(getmakevar KERNSRCDIR)"
		KERNARCHDIR="$(getmakevar KERNARCHDIR)"
		make_in_dir "${KERNSRCDIR}/${KERNARCHDIR}/compile" obj
	fi
	KERNCONFDIR="$(getmakevar KERNCONFDIR)"
	KERNOBJDIR="$(getmakevar KERNOBJDIR)"
	case "${kernelconf}" in
	*/*)
		kernelconfpath="${kernelconf}"
		kernelconfname="${kernelconf##*/}"
		;;
	*)
		kernelconfpath="${KERNCONFDIR}/${kernelconf}"
		kernelconfname="${kernelconf}"
		;;
	esac
	kernelbuildpath="${KERNOBJDIR}/${kernelconfname}"
}

buildkernel()
{
	if ! ${do_tools} && ! ${buildkernelwarned:-false}; then
		# Building tools every time we build a kernel is clearly
		# unnecessary.  We could try to figure out whether rebuilding
		# the tools is necessary this time, but it doesn't seem worth
		# the trouble.  Instead, we say it's the user's responsibility
		# to rebuild the tools if necessary.
		#
		statusmsg "Building kernel without building new tools"
		buildkernelwarned=true
	fi
	getkernelconf $1
	statusmsg2 "Building kernel:" "${kernelconf}"
	statusmsg2 "Build directory:" "${kernelbuildpath}"
	${runcmd} mkdir -p "${kernelbuildpath}" ||
	    bomb "Cannot mkdir: ${kernelbuildpath}"
	if [ "${MKUPDATE}" = "no" ]; then
		make_in_dir "${kernelbuildpath}" cleandir
	fi
	[ -x "${TOOLDIR}/bin/${toolprefix}config" ] \
	|| bomb "${TOOLDIR}/bin/${toolprefix}config does not exist. You need to \"$0 tools\" first."
	${runcmd} "${TOOLDIR}/bin/${toolprefix}config" -b "${kernelbuildpath}" \
		-s "${TOP}/sys" "${kernelconfpath}" ||
	    bomb "${toolprefix}config failed for ${kernelconf}"
	make_in_dir "${kernelbuildpath}" depend
	make_in_dir "${kernelbuildpath}" all

	if [ "${runcmd}" != "echo" ]; then
		statusmsg "Kernels built from ${kernelconf}:"
		kernlist=$(awk '$1 == "config" { print $2 }' ${kernelconfpath})
		for kern in ${kernlist:-netbsd}; do
			[ -f "${kernelbuildpath}/${kern}" ] && \
			    echo "  ${kernelbuildpath}/${kern}"
		done | tee -a "${results}"
	fi
}

releasekernel()
{
	getkernelconf $1
	kernelreldir="${RELEASEDIR}/${RELEASEMACHINEDIR}/binary/kernel"
	${runcmd} mkdir -p "${kernelreldir}"
	kernlist=$(awk '$1 == "config" { print $2 }' ${kernelconfpath})
	for kern in ${kernlist:-netbsd}; do
		builtkern="${kernelbuildpath}/${kern}"
		[ -f "${builtkern}" ] || continue
		releasekern="${kernelreldir}/${kern}-${kernelconfname}.gz"
		statusmsg2 "Kernel copy:" "${releasekern}"
		if [ "${runcmd}" = "echo" ]; then
			echo "gzip -c -9 < ${builtkern} > ${releasekern}"
		else
			gzip -c -9 < "${builtkern}" > "${releasekern}"
		fi
	done
}

buildmodules()
{
	setmakeenv MKBINUTILS no
	if ! ${do_tools} && ! ${buildmoduleswarned:-false}; then
		# Building tools every time we build modules is clearly
		# unnecessary as well as a kernel.
		#
		statusmsg "Building modules without building new tools"
		buildmoduleswarned=true
	fi

	statusmsg "Building kernel modules for NetBSD/${MACHINE} ${DISTRIBVER}"
	if [ "${MKOBJDIRS}" != "no" ]; then
		make_in_dir sys/modules obj ||
		    bomb "Failed to make obj in sys/modules"
	fi
	if [ "${MKUPDATE}" = "no" ]; then
		make_in_dir sys/modules cleandir
	fi
	${runcmd} "${makewrapper}" ${parallel} do-sys-modules ||
	    bomb "Failed to make do-sys-modules"

	statusmsg "Successful build of kernel modules for NetBSD/${MACHINE} ${DISTRIBVER}"
}

installmodules()
{
	dir="$1"
	${runcmd} "${makewrapper}" INSTALLMODULESDIR="${dir}" installmodules ||
	    bomb "Failed to make installmodules to ${dir}"
	statusmsg "Successful installmodules to ${dir}"
}

installworld()
{
	dir="$1"
	${runcmd} "${makewrapper}" INSTALLWORLDDIR="${dir}" installworld ||
	    bomb "Failed to make installworld to ${dir}"
	statusmsg "Successful installworld to ${dir}"
}

# Run rump build&link tests.
#
# To make this feasible for running without having to install includes and
# libraries into destdir (i.e. quick), we only run ld.  This is possible
# since the rump kernel is a closed namespace apart from calls to rumpuser.
# Therefore, if ld complains only about rumpuser symbols, rump kernel
# linking was successful.
#
# We test that rump links with a number of component configurations.
# These attempt to mimic what is encountered in the full build.
# See list below.  The list should probably be either autogenerated
# or managed elsewhere; keep it here until a better idea arises.
#
# Above all, note that THIS IS NOT A SUBSTITUTE FOR A FULL BUILD.
#

RUMP_LIBSETS='
	-lrump,
	-lrumpvfs -lrump,
	-lrumpvfs -lrumpdev -lrump,
	-lrumpnet -lrump,
	-lrumpkern_tty -lrumpvfs -lrump,
	-lrumpfs_tmpfs -lrumpvfs -lrump,
	-lrumpfs_ffs -lrumpfs_msdos -lrumpvfs -lrumpdev_disk -lrumpdev -lrump,
	-lrumpnet_virtif -lrumpnet_netinet -lrumpnet_net -lrumpnet -lrump,
	-lrumpnet_sockin -lrumpfs_smbfs -lrumpdev_netsmb
	    -lrumpkern_crypto -lrumpdev -lrumpnet -lrumpvfs -lrump,
	-lrumpnet_sockin -lrumpfs_nfs -lrumpnet -lrumpvfs -lrump,
	-lrumpdev_cgd -lrumpdev_raidframe -lrumpdev_disk -lrumpdev_rnd
	    -lrumpdev_dm -lrumpdev -lrumpvfs -lrumpkern_crypto -lrump'
dorump()
{
	local doclean=""
	local doobjs=""

	# we cannot link libs without building csu, and that leads to lossage
	[ "${1}" != "rumptest" ] && bomb 'build.sh rump not yet functional. ' \
	    'did you mean "rumptest"?'

	# create obj and distrib dirs
	if [ "${MKOBJDIRS}" != "no" ]; then
		make_in_dir "${NETBSDSRCDIR}/etc/mtree" obj
		make_in_dir "${NETBSDSRCDIR}/sys/rump" obj
	fi
	${runcmd} "${makewrapper}" ${parallel} do-distrib-dirs \
	    || bomb 'could not create distrib-dirs'

	[ "${MKUPDATE}" = "no" ] && doclean="cleandir"
	targlist="${doclean} ${doobjs} dependall install"
	# optimize: for test we build only static libs (3x test speedup)
	if [ "${1}" = "rumptest" ] ; then
		setmakeenv NOPIC 1
		setmakeenv NOPROFILE 1
	fi
	for cmd in ${targlist} ; do
		make_in_dir "${NETBSDSRCDIR}/sys/rump" ${cmd}
	done

	# if we just wanted to build & install rump, we're done
	[ "${1}" != "rumptest" ] && return

	${runcmd} cd "${NETBSDSRCDIR}/sys/rump/librump/rumpkern" \
	    || bomb "cd to rumpkern failed"
	md_quirks=`${runcmd} "${makewrapper}" -V '${_SYMQUIRK}'`
	# one little, two little, three little backslashes ...
	md_quirks="$(echo ${md_quirks} | sed 's,\\,\\\\,g'";s/'//g" )"
	${runcmd} cd "${TOP}" || bomb "cd to ${TOP} failed"
	tool_ld=`${runcmd} "${makewrapper}" -V '${LD}'`

	local oIFS="${IFS}"
	IFS=","
	for set in ${RUMP_LIBSETS} ; do
		IFS="${oIFS}"
		${runcmd} ${tool_ld} -nostdlib -L${DESTDIR}/usr/lib	\
		    -static --whole-archive ${set} 2>&1 -o /tmp/rumptest.$$ | \
		      awk -v quirks="${md_quirks}" '
			/undefined reference/ &&
			    !/more undefined references.*follow/{
				if (match($NF,
				    "`(rumpuser_|__" quirks ")") == 0)
					fails[NR] = $0
			}
			/cannot find -l/{fails[NR] = $0}
			/cannot open output file/{fails[NR] = $0}
			END{
				for (x in fails)
					print fails[x]
				exit x!=0
			}'
		[ $? -ne 0 ] && bomb "Testlink of rump failed: ${set}"
	done
	statusmsg "Rump build&link tests successful"
}

main()
{
	initdefaults
	_args=$@
	parseoptions "$@"

	sanitycheck

	build_start=$(date)
	statusmsg2 "${progname} command:" "$0 $*"
	statusmsg2 "${progname} started:" "${build_start}"
	statusmsg2 "NetBSD version:"   "${DISTRIBVER}"
	statusmsg2 "MACHINE:"          "${MACHINE}"
	statusmsg2 "MACHINE_ARCH:"     "${MACHINE_ARCH}"
	statusmsg2 "Build platform:"   "${uname_s} ${uname_r} ${uname_m}"
	statusmsg2 "HOST_SH:"          "${HOST_SH}"

	rebuildmake
	validatemakeparams
	createmakewrapper

	# Perform the operations.
	#
	for op in ${operations}; do
		case "${op}" in

		makewrapper)
			# no-op
			;;

		tools)
			buildtools
			;;

		sets)
			statusmsg "Building sets from pre-populated ${DESTDIR}"
			${runcmd} "${makewrapper}" ${parallel} ${op} ||
			    bomb "Failed to make ${op}"
			setdir=${RELEASEDIR}/${RELEASEMACHINEDIR}/binary/sets
			statusmsg "Built sets to ${setdir}"
			;;

		cleandir|obj|build|distribution|release|sourcesets|syspkgs|params)
			${runcmd} "${makewrapper}" ${parallel} ${op} ||
			    bomb "Failed to make ${op}"
			statusmsg "Successful make ${op}"
			;;

		iso-image|iso-image-source)
			${runcmd} "${makewrapper}" ${parallel} \
			    CDEXTRA="$CDEXTRA" ${op} ||
			    bomb "Failed to make ${op}"
			statusmsg "Successful make ${op}"
			;;

		live-image|install-image)
			# install-image and live-image require mtree spec files
			# built with UNPRIVED.  Assume UNPRIVED build has been
			# performed if METALOG file is created in DESTDIR.
			if [ ! -e "${DESTDIR}/METALOG" ] ; then
				bomb "The release binaries must have been built with -U to create images."
			fi
			${runcmd} "${makewrapper}" ${parallel} ${op} ||
			    bomb "Failed to make ${op}"
			statusmsg "Successful make ${op}"
			;;
		kernel=*)
			arg=${op#*=}
			buildkernel "${arg}"
			;;

		releasekernel=*)
			arg=${op#*=}
			releasekernel "${arg}"
			;;

		modules)
			buildmodules
			;;

		installmodules=*)
			arg=${op#*=}
			if [ "${arg}" = "/" ] && \
			    (	[ "${uname_s}" != "NetBSD" ] || \
				[ "${uname_m}" != "${MACHINE}" ] ); then
				bomb "'${op}' must != / for cross builds."
			fi
			installmodules "${arg}"
			;;

		install=*)
			arg=${op#*=}
			if [ "${arg}" = "/" ] && \
			    (	[ "${uname_s}" != "NetBSD" ] || \
				[ "${uname_m}" != "${MACHINE}" ] ); then
				bomb "'${op}' must != / for cross builds."
			fi
			installworld "${arg}"
			;;

		rump|rumptest)
			dorump "${op}"
			;;

		*)
			bomb "Unknown operation \`${op}'"
			;;

		esac
	done

	statusmsg2 "${progname} ended:" "$(date)"
	if [ -s "${results}" ]; then
		echo "===> Summary of results:"
		sed -e 's/^===>//;s/^/	/' "${results}"
		echo "===> ."
	fi
}

main "$@"