path: root/gcc-config

#!/bin/bash
# Copyright 2002-2019 Gentoo Authors
# Distributed under the terms of the GNU General Public License v2

# Format of /etc/env.d/gcc/ contents:
#  config-<TARGET>:	CURRENT=<TARGET>-<VER>
#  <TARGET>-<VER>:	has gcc-specific variables (provided by sys-devel/gcc)

: ${ROOT:=/}
[[ ${ROOT} != */ ]] && ROOT="${ROOT}/"
[[ ${ROOT} != /* ]] && ROOT="${PWD%/}/${ROOT}"
EPREFIX="@GENTOO_EPREFIX@"
[[ ${EPREFIX} == @*@ ]] && EPREFIX=""
EROOT="${ROOT%/}${EPREFIX}/"

cd /

trap ":" INT QUIT TSTP

argv0=${0##*/}
functions_script="${EPREFIX}/lib/gentoo/functions.sh"
source "${functions_script}" || {
	echo "${argv0}: Could not source ${functions_script}!" 1>&2
	exit 1
}
esyslog() { :; }
has() { [[ " ${*:2} " == *" $1 "* ]]; }
die() { eerror "${argv0}: $*"; exit 1; }
umask 022

# *BSD SED does not work as-is, use GNU SED. TODO: find details.
SED=$(type -P gsed)
: ${SED:=$(type -P sed)}

# Further pain: `tac` is not available everywhere #390179
if ! type -P tac >/dev/null ; then
	tac() { ${SED} -e '1!G;h;$!d' "$@" ; }
fi

PV="@PV@"
[[ ${PV} == @*@ ]] && PV="git"
GENTOO_LIBDIR="@GENTOO_LIBDIR@"
[[ ${GENTOO_LIBDIR} == @*@ ]] && GENTOO_LIBDIR="lib"

usage() {
	cat <<-EOF
	Usage: gcc-config [options] [CC Profile]
	Change the current compiler profile, or give info about profiles.

	Options:
	  -C, --nocolor              Disable color output
	  -O, --use-old              Use the old profile if one was selected.
	  -f, --force                Make sure all config files are regenerated.
	  -c, --get-current-profile  Print current used gcc profile.
	  -l, --list-profiles        Print a list of available profiles.
	  -S, --split-profile        Split profiles into their components
	  -E, --print-environ        Print environment that can be used to setup the
	                             current gcc profile, or a specified one.
	  -B, --get-bin-path         Print path where binaries of the given/current
	                             profile are located.
	  -L, --get-lib-path         Print path where libraries of the given/current
	                             profile are located.

	Profile names are of the form:  <CTARGET>-<version>
	For example:                    i686-pc-linux-gnu-3.2.1
	EOF
	exit ${1:-1}
}
[[ $# -lt 1 ]] && usage 1

# Usage: version_sorted_paths <CHOST>
# Returns paths ordered by version from olders to newest.
# We use the following hack: assume the input containst digits only in places of versions
# Normalizer:
#    echo "hello-world-1.2.3.444.56778" | ${SED} -e 's/[0-9]\+/0000&/g' | ${SED} -e 's/0*\([0-9]\{4\}\)/\1/g'
#    hello-world-0001.0002.0003.0444.56778
# That way we can have 9.0 < 10.0 order.
# TODO: explore how portable 'sort -V' is and try using that instead.
version_sorted_paths() {
	local p mangled_v
	for p in "$@"; do
		# TODO: avoid -r
		mangled_v=$(printf "%s" "${p}" |
			${SED} -e 's/[0-9]\+/0000&/g' |
			${SED} -e 's/0*\([0-9]\{4\}\)/\1/g'
		)
		printf "%s %s\n" "${mangled_v}" "${p}"
	done | LANG=C sort | $SED -e 's/^.* //g'
}

# Usage: source_var <var> <file> [default value]
source_var() {
	unset $1
	local val=$(source "$2"; echo "${!1}")
	: ${val:=$3}
	eval $1=\"${val}\"
}
show_var() {
	source_var "$@"
	echo "${!1}"
}

source_profile() {
	# Compatibility with profile files created before 2019-09-05.
	# These profile files were setting PATH variable.
	# Sourcing them without restoring previous PATH value breaks gcc-config.
	local backup_PATH=${PATH}

	source "$1"

	PATH=${backup_PATH}
}

try_real_hard_to_find_CHOST() {
	#
	# First we read make.conf
	#

	local varname=${1:-CHOST}
	local conf=${EROOT}/etc/portage/make.conf
	if [[ ! -e ${conf} && -e ${EROOT}/etc/make.conf ]] ; then
		conf=${EROOT}/etc/make.conf
	fi
	local ret=$(source "${conf}" 2>/dev/null ; echo ${!varname})
	if [[ -z ${ret} ]] ; then
		# newer portage supports spaces between the var and =
		# CHOST     =  "this-is-retarded"
		ret=$(eval $(
			${SED} -n \
				-e 's:[[:space:]]::g' \
				-e "/^${varname}=/p" \
				"${conf}"
			) ; echo ${!varname}
		)
	fi

	if [[ -n ${ret} ]] ; then
		echo ${ret}
		return 0
	fi

	#
	# Then we try /etc/env.d/gcc/config-${CTARGET}
	#
	if [[ -s ${EROOT}/etc/env.d/gcc/config-${CTARGET} ]] ; then
		ret=$(split_gcc_ver $(show_var CURRENT "${EROOT}"/etc/env.d/gcc/config-${CTARGET}))
		echo ${ret% *}
	fi
}

get_chost() {
	# If it's set in the env, trust the setting.  If it's wrong,
	# then that's the caller's problem.
	[[ -n ${CHOST} ]] && return 0

	export CHOST

	# make sure portage isnt broken
	if python -V &>/dev/null ; then
		CHOST=$(portageq envvar CHOST 2>/dev/null)
	else
		ewarn "Python seems to be broken, attempting to locate CHOST ourselves ..."
		CHOST=$(try_real_hard_to_find_CHOST)
	fi

	if [[ -z ${CHOST} ]] ; then
		eerror "${argv0}: Could not get portage CHOST!"
		eerror "${argv0}: You should verify that CHOST is set in one of these places:"
		eerror "${argv0}:  - ${EROOT}/etc/portage/make.conf"
		eerror "${argv0}:  - active environment"
		exit 1
	fi
}

is_cross_compiler() {
	[[ ${CC_COMP/${CHOST}} == ${CC_COMP} ]]
}

is_same_mountpoint() {
	local file1=$1 file2=$2

	if type -P findmnt > /dev/null ; then
		local file1_mountpoint=$(findmnt -n -o TARGET -T "${file1}")
		local file2_mountpoint=$(findmnt -n -o TARGET -T "${file2}")

		[[ ${file1_mountpoint} == ${file2_mountpoint} ]]
		return
	else
		local file1_check_file file2_check_file result
		if [[ -d ${file1} ]] ; then
			file1_check_file=${file1}/.gcc.config.mountpoint_check_file1.$$
		else
			file1_check_file=${file1%/*}/.gcc.config.mountpoint_check_file1.$$
		fi
		if [[ -d ${file2} ]] ; then
			file2_check_file=${file2}/.gcc.config.mountpoint_check_file2.$$
		else
			file2_check_file=${file2%/*}/.gcc.config.mountpoint_check_file2.$$
		fi

		rm -f "${file1_check_file}" "${file2_check_file}"
		touch "${file1_check_file}"
		ln "${file1_check_file}" "${file2_check_file}" 2> /dev/null
		result=$?
		rm -f "${file1_check_file}" "${file2_check_file}"
		return ${result}
	fi
}

# Usage: atomic_ln <source file> <destination dir> <destination file name>
atomic_ln() {
	local src=$1 dst=$2 dstfile=$3 tmp
	tmp="${dst}/.gcc.config.${dstfile}"
	# `ln` will expand into unlink();symlink(); which
	# is not atomic for a small amount of time, but
	# `mv` is a single rename() call
	ln -sf "${src}" "${tmp}"
	mv "${tmp}" "${dst}/${dstfile}"
}

uniq_wrapper_list() {
	local ver=$1; shift
	# We want to normalize away existing target prefix.
	set -- "${@#${CTARGET}-*}"
	# And we want to filter out any version suffixed progs.
	set -- "${@//*-${ver}}"
	# Finally, filter out dupes.
	printf '%s\n' "$@" | sort -u
}

update_wrappers() {
	# Update the wrappers for this profile.  We need to clean out
	# the old wrappers if the functionality no longer exists (like
	# re-emerging gcc with diff USE flags) and install new wrappers
	# for new functionality (like a version bump).
	local x CTARGET=$1

	# Facts on gcc's private binary dir contents:
	#
	# Native directory looks like:
	#     /usr/x86_64-pc-linux-gnu/gcc-bin/11.0.0
	#   Contents looks like:
	#   - 'foo' ('gcc', 'c++', 'gcc-ar', 'lto-dump')
	#   - 'foo-${v}' (go-11, gofmt-11)
	#   - ${CTARGET}-foo ('${CTARGET}-gcc', ...)
	#
	#   Not each 'foo' has it's ${CTARGET}-foo match.
	#   Examples are:
	#   - lto-dump, gcov-dump, gcov-tool (no ${CTARGET}-lto-dump equvalent)
	#   - go-${MAJOR}, gofmt-${MAJOR} (no ${CTARGET}-go-${MAJOR} equivalent)
	#   - ${CTARGET}-gcc-11.0.0 (no gcc-11.0.0 equivalent)
	#   TODO: is it a gcc or toolchain.eclass bug?
	#
	# Cross directory looks like:
	#     /usr/x86_64-pc-linux-gnu/ia64-unknown-linux-gnu/gcc-bin/10.1.0
	#   Contents look like:
	#   - ${CTARGET}-foo ('${CTARGET}-gcc', ...)
	#
	#   Every tool is prefixed.

	# Use the old dir to see what we wrapped up previously.
	local old_wrappers=( $(
		[[ -n ${OLD_GCC_PATH} ]] || exit 1
		uniq_wrapper_list "${OLD_CC_COMP_VERSION}" $(
			cd "${ROOT}${OLD_GCC_PATH}" 2>/dev/null || exit 1
			echo *
		)
	) )

	# See what new stuff we need to wrap up.
	local new_wrappers=( $(
		uniq_wrapper_list "${CC_COMP_VERSION}" $(
			cd "${ROOT}${GCC_PATH}" || exit 1
			echo *
		)
	) )
	[[ -z ${new_wrappers} ]] && return 1

	# First delete the wrappers that the old one provided but the
	# new ones do not.
	for x in "${old_wrappers[@]}" ; do
		has "${x}" "${new_wrappers[@]}" && continue
		rm -f "${EROOT}usr/bin/${x}" "${EROOT}usr/bin/${CTARGET}-${x}"
	done

	# For all toolchains, we want to create the fully qualified
	# `tuple-foo`.  Only native ones do we want the simple `foo`
	# and only for USE_NATIVE_LINKS=yes mode.
	local all_wrappers=( ${new_wrappers[@]/#/${CTARGET}-} )
	if ! is_cross_compiler ; then
		all_wrappers+=( "${new_wrappers[@]}" )
		if [[ ${USE_CC_WRAPPERS} == "yes" ]]; then
			# There are a few fun extra progs which we have to handle #412319
			all_wrappers+=( cc:gcc f77:g77 )
		fi
	fi

	# Then install wrappers for anything new to this profile.
	local ref
	for x in "${all_wrappers[@]}" ; do
		# We want to figure out the 'reference file' for each
		# wrapper (the binary we're 'wrapping') so that we can
		# sync mtimes together.  This makes things like ccache
		# happy.  See Bug #70548 for more info.
		#
		# x=cc:gcc -> ref=/path/to/gcc
		ref="${ROOT}${GCC_PATH}/${x#*:}"
		# x=cc:gcc -> x=cc
		x=${x%:*}

		if [[ ! -x ${ref} ]] ; then
			if is_cross_compiler ; then
				ewarn "insanity with ${x} and ${ref}"
			else
				# For native targets, the ref might not be
				# fully qualified, so use the short name.
				ref="${ROOT}${GCC_PATH}/${x#${CTARGET}-}"
			fi
		fi

		# Now do the actual linking to the target binary
		if [[ ${x#${CTARGET}-} == ${x} && ${USE_NATIVE_LINKS} != yes ]]; then
			# Delete stale native symlink.
			rm -f "${EROOT}usr/bin/${x}"
		elif [[ -x ${ref} ]] ; then
			atomic_ln "${ref#${ROOT}}" "${EROOT}usr/bin" "${x}"
		else
			# Make sure we have no stale wrappers
			rm -f "${EROOT}usr/bin/${x}"
		fi
	done
	# legacy cruft, make sure we dont leave it laying around #143205
	rm -f "${EROOT}usr/bin/${CTARGET}-cc" "${EROOT}usr/bin"/{${CTARGET}-,}g{cc,++}{32,64}

	# handle the canonical cpp wrapper
	if ! is_cross_compiler ; then
		if [[ ${USE_NATIVE_LINKS} == yes ]]; then
			atomic_ln "${EPREFIX%/}/usr/bin/${CTARGET}-cpp" "${EROOT}lib" "cpp"
		else
			rm -f "${EROOT}lib/cpp"
		fi
	fi

	# handle c89 and c99 wrappers
	if ! is_cross_compiler ; then
		if [[ ${USE_NATIVE_LINKS} == yes ]]; then
			# In June 2020 gcc-config taken over file handling from toolchain.eclass.
			cp -fpP "${EROOT}"usr/share/gcc-config/c89 "${EROOT}"usr/bin/c89
			cp -fpP "${EROOT}"usr/share/gcc-config/c99 "${EROOT}"usr/bin/c99
		else
			rm -f "${EROOT}"usr/bin/c89
			rm -f "${EROOT}"usr/bin/c99
		fi
	fi
}

mv_if_diff() {
	if cmp -s "$1" "$2" ; then
		rm -f "$1"
		return 0
	else
		mv -f "$1" "$2"
		return 1
	fi
}

handle_split_usr() {
	# We need to make sure that libgcc_s.so / libunwind.so make it into /lib.
	# On many systems (x86/amd64/etc...), this will probably never matter,
	# but on other systems (arm/mips/etc...), this is quite critical.
	# http://bugs.gentoo.org/60190
	#
	# Note: libunwind.so.7 is a DT_NEEDED dependency only on ia64 systems
	# where libunwind.so.7 is provided by gcc itself, see:
	#    https://bugs.gentoo.org/667020
	#    https://bugs.gentoo.org/693252
	#
	# The funky move magic is required for proper updating of in-use files.

	# Gentoo Prefix systems don't "boot", so no need to handle split-/usr
	[[ -n ${EPREFIX} ]] && return 0

	# We use the same ordering logic as mentioned in the MY_LDPATH setup.
	# We get the libs from the latest version available.
	local LDPATH
	eval $(grep -h '^LDPATH=' $(version_sorted_paths "${GCC_ENV_D}"/${CHOST}-*) | tail -1)
	LDPATH=${LDPATH%%:*}

	# If GCC directory is not in separate mountpoint than /lib,
	# then do not bother with copying libraries to /lib.
	if is_same_mountpoint "${EROOT}/lib" "${ROOT}/${LDPATH}" ; then
		local lib old_libs=0 saved_nullglob=$(shopt -p nullglob)
		shopt -s nullglob
		for lib in "${EROOT}"/lib*/libgcc_s{.so*,*dylib} "${EROOT}"/lib*/libunwind.so.7* ; do
			# If we previously had stuff in /, make sure ldconfig gets re-run.
			einfo "Removing '${lib}'"
			rm -f "${lib}"
			old_libs=1
		done
		${saved_nullglob}
		return ${old_libs}
	fi

	# Only bother with this stuff for the native ABI.  We assume the user
	# doesn't have critical binaries for non-native ABIs which is fair.
	local gcclib
	local libdir="${EROOT}${GENTOO_LIBDIR}"
	mkdir -p "${libdir}"/.gcc.config.new || return 0 # !?!?!
	for gcclib in gcc_s unwind ; do
		# This assumes that we always have the .so symlink,
		# but for now, that should be safe ...
		for gcclib in "${ROOT}${LDPATH}"/lib${gcclib}.so.* ; do
			[[ -e ${gcclib} ]] || continue
			einfo "Backing up '${gcclib}' to '${libdir}"
			cp -pP "${gcclib}" "${libdir}"/.gcc.config.new/
			# no need to sanity `rm` this as the `mv` should take care
			# of it.  we also need this step to be completely atomic
			# for systems that have even `mv` linked against libgcc_s.so.
			# http://bugs.gentoo.org/150257
			mv -f "${libdir}"/.gcc.config.new/* "${libdir}"/
		done
	done
	rmdir "${libdir}"/.gcc.config.new

	return 0
}

prefix_copy_gcc_libs() {
	# no business here if not Prefix
	[[ -z ${EPREFIX} ]] && return 0

	# To emulate properly what ld.so.conf magic does for non-prefix,
	# we have to copy the libs of all installed (native) GCC's and
	# make sure we do the current one as last, such that the
	# pointers for the unversioned libs point to the currently
	# selected version.  This is only necessary for platforms that use
	# shared libs, and only record the object name (not the full path).
	case ${CHOST} in
		*-mint*)
			# static only, nothing to do here
			return 0
			;;
		*-darwin*)
			# Mach-O records all references with full path, hence each
			# object has links to the GCC-specific version of the lib.
			return 0
			;;
	esac

	# dstlibgcc location is added to RPATH by the binutils wrapper
	local dstlibgcc=${EROOT}/usr/${CHOST}/lib/gcc

	# Prepare empty directories first
	local temporary=.gcc.config.new
	rm -rf   "${dstlibgcc}"/${temporary} || return 1
	mkdir -p "${dstlibgcc}"/${temporary} || return 1

	local LIBSUFFIX
	case ${CHOST} in
		*-aix*)
			LIBSUFFIX="a"
			AIXLIBS=

			do_single_runtime() {
				local sourcedir=$1; shift
				local libname=$1; shift
				local targetdir=$1; shift
				local finaldir=$1; shift

				aixdll \
					--merge-runtime \
					--finish=false \
					--target="${targetdir}"/lib${libname}.${LIBSUFFIX} \
					"${sourcedir}"/lib${libname}.${LIBSUFFIX} \
					|| return 1
				[[ ${AIXLIBS} == *":${targetdir}/lib${libname}.${LIBSUFFIX}:"* ]] \
					|| AIXLIBS="${AIXLIBS}:${targetdir}/lib${libname}.${LIBSUFFIX}:"
			}

			finish_runtime_dir() {
				local sourcedir=$1; shift
				local targetdir=$1; shift
				local cleanup=$1; shift

				local f save_IFS
				save_IFS=$IFS; IFS=:
				for f in ${AIXLIBS}; do
					IFS=$save_IFS
					[[ -n ${f} ]] || continue
					aixdll \
						--finish-merge \
						--keepdir=false \
						"${f}" \
						|| return 1
				done
				IFS=$save_IFS
				unset AIXLIBS

				finish_runtime_dir_elf \
					"${sourcedir}" \
					"${targetdir}" \
					${cleanup} \
					|| return 1
			}
			;;
		hppa64*-hpux*)
			LIBSUFFIX="sl"
			do_single_runtime() {
				do_single_runtime_elf "$@"
			}
			finish_runtime_dir() {
				finish_runtime_dir_elf "$@"
			}
			;;
		hppa*-hpux*)
			LIBSUFFIX="sl"
			do_single_runtime() {
				local sourcedir=$1; shift
				local libname=$1; shift
				local targetdir=$1; shift
				local finaldir=$1; shift

				# when using some simple shell script wrappers (again :)),
				# there may be no libs around!
				if [[ -n $(ls "${sourcedir}"/lib${libname}.*${LIBSUFFIX}* 2>/dev/null) ]]; then
					cp -fpP "${sourcedir}"/lib${libname}.*${LIBSUFFIX}* "${targetdir}" || return 1
					# gcc creates "libgcc_s.4" with symlink "libgcc_s.sl -> libgcc_s.4", and
					# we patch it to also set the 'internal name' (=soname) (gcc-PR40913).
					if [[ ${libname} == 'gcc_s' ]]; then
						if [[ -n $(ls "${sourcedir}"/lib${libname}.[0-9] 2>/dev/null) ]]; then
							cp -fpP "${sourcedir}"/lib${libname}.[0-9] "${targetdir}" || return 1
						fi
					fi
					# we do not need the unversioned lib, as linking
					# is done against the used gcc's private copy.
					rm -f "${targetdir}"/lib${libname}.${LIBSUFFIX} || return 1
				fi
			}
			finish_runtime_dir() {
				finish_runtime_dir_elf "$@"
			}
			;;
		*)
			LIBSUFFIX="so"
			do_single_runtime() {
				do_single_runtime_elf "$@"
			}
			finish_runtime_dir() {
				finish_runtime_dir_elf "$@"
			}
			;;
	esac

	do_single_runtime_elf() {
		local sourcedir=$1; shift
		local libname=$1; shift
		local targetdir=$1; shift
		local finaldir=$1; shift

		# when using some simple shell script wrappers (again :)),
		# there may be no libs around!
		if [[ -n $(ls "${sourcedir}"/lib${libname}.*${LIBSUFFIX}* 2>/dev/null) ]]; then
			cp -fpP "${sourcedir}"/lib${libname}.*${LIBSUFFIX}* "${targetdir}" || return 1
			# we do not need the unversioned lib, as linking
			# is done against the used gcc's private copy.
			rm -f "${targetdir}"/lib${libname}.${LIBSUFFIX} || return 1
		fi
	}

	finish_runtime_dir_elf() {
		local sourcedir=$1; shift
		local targetdir=$1; shift
		local cleanup=$1; shift

		if [[ ${cleanup} == clean ]]; then
			for f in "${targetdir}"/*; do
				[[ ${f} == ${sourcedir} ]] && continue
				[[ -e "${sourcedir}/${f##*/}" ]] && continue
				rm -f "${f}"
			done
		fi

		# move symlinks first:
		# because of file ordering, the real files may be
		# moved before the symlinks, causing the symlinks
		# going broken.
		for f in "${sourcedir}"/*; do
			[[ -e ${f} && -L ${f} ]] || continue
			# use backups: hpux cannot overwrite sharedlibs in use: "Text file busy"
			rm -f "${targetdir}"/${f##*/}*'~' >/dev/null 2>&1
			mv -f --backup=numbered --suffix='~' "${f}" "${targetdir}"/${f##*/} || return 1
			rm -f "${targetdir}"/${f##*/}*'~' >/dev/null 2>&1
		done

		for f in "${sourcedir}"/*; do
			[[ -f "${f}" ]] || continue
			# use backups: hpux cannot overwrite sharedlibs in use: "Text file busy"
			rm -f "${targetdir}"/${f##*/}*'~' >/dev/null 2>&1
			mv -f --backup=numbered --suffix='~' "${f}" "${targetdir}"/${f##*/} || return 1
			rm -f "${targetdir}"/${f##*/}*'~' >/dev/null 2>&1
		done
		rmdir "${sourcedir}"
	}

	# We don't rely on iteration order here.
	local GCC_PROFILES=$(LC_ALL="C" ls ${GCC_ENV_D}/${CHOST}-*)

	local targetdirs= GCC_PATH= LDPATH=
	for x in ${GCC_PROFILES} ; do
		unset GCC_PATH LDPATH
		eval $(
			source_profile "${x}"
			echo "GCC_PATH='${GCC_PATH}'"
			echo "LDPATH='${LDPATH%%:*}'"
		)

		pushd "${ROOT%/}${LDPATH}" > /dev/null || return 1

		local donelibs= lib= gcclib=
		for lib in lib*.${LIBSUFFIX}; do
			gcclib=${lib#lib}
			gcclib=${gcclib%.${LIBSUFFIX}}
			gcclib=${gcclib%%.[0-9]*} # we need the unversioned libname.
			[[ ${donelibs} != *" ${gcclib} "* ]] || continue
			donelibs="${donelibs} ${gcclib} "

			[[ ${targetdirs} == *":${dstlibgcc},clean:"* ]] ||
				targetdirs="${targetdirs}:${dstlibgcc},clean:"

			do_single_runtime \
				"${ROOT%/}${LDPATH}" \
				${gcclib} \
				"${dstlibgcc}"/${temporary} \
				"${dstlibgcc}" \
				|| return 1
		done

		popd > /dev/null
	done

	local clean= targetdir=
	local save_IFS=$IFS
	IFS=:
	for targetdir in ${targetdirs}; do
		IFS=${save_IFS}
		[[ -n ${targetdir} ]] || continue

		# eventually cleanup old files
		clean=${targetdir##*,}

		targetdir=${targetdir%,*}

		finish_runtime_dir \
			"${targetdir}"/${temporary} \
			"${targetdir}" \
			${clean} \
			|| return 1
	done
	IFS=${save_IFS}
}

switch_profile() {
	local OLD_CC_COMP OLD_CC_COMP_VERSION OLD_GCC_PATH OLD_GCC_VER
	local GCC_PATH

	# Make sure we have write access to the dirs.  Do not require `root`
	# so that we work with prefix/cross/etc... setups that run as user.
	[[ ! -w ${EROOT} ]] && die "need write access to ${EROOT}"

	if is_cross_compiler ; then
		ebegin "Switching cross-compiler to ${CC_COMP}"
	else
		ebegin "Switching native-compiler to ${CC_COMP}"
	fi

	# Setup things properly again for this profile
	unset GCC_SPECS LDPATH MULTIOSDIRS
	source_profile "${GCC_ENV_D}/${CC_COMP}"
	# Support older configs that did not setup MULTIOSDIRS for us.
	: ${MULTIOSDIRS:=../${GENTOO_LIBDIR}}

	# Ignore active profile errors here since we're switching away
	OLD_CC_COMP=$(get_current_profile 2>/dev/null)
	if [[ -f ${GCC_ENV_D}/${OLD_CC_COMP} ]] ; then
		OLD_GCC_PATH=$(show_var GCC_PATH "${GCC_ENV_D}/${OLD_CC_COMP}")
		OLD_GCC_VER=$(show_var GCC_VER "${GCC_ENV_D}/${OLD_CC_COMP}")
	fi
	OLD_CC_COMP_VERSION=${OLD_GCC_VER:-$(chop_gcc_ver_spec ${OLD_CC_COMP})}

	# GCC_SPECS have long been stable, and people messing with
	# them know better than to install bad paths, so don't bother
	# with sanity checks anymore.

	echo "CURRENT=${CC_COMP}" > "${GCC_ENV_D}/config-${CTARGET}"

	# Give native configs slight distinction from cross-compilers
	# by giving it higher priority.
	local envd envd_num envd_changed=0
	is_cross_compiler && envd_num="05" || envd_num="04"
	envd="${ENV_D}/${envd_num}gcc-${CTARGET}"
	cat <<-EOF > "${envd}.tmp"
		# Autogenerated by 'gcc-config'.
	EOF
	if ! is_cross_compiler ; then
		# Only write GCC_SPECS for the native compiler. #420097
		# Otherwise, the env.d of cross-compilers come after the
		# native one and overrides the native setting.  Further,
		# we don't support GCC_SPECS with cross-compilers, so
		# writing out that settings doesn't make much sense.
		printf 'GCC_SPECS="%s"\n' "${GCC_SPECS}" >> "${envd}.tmp"

		# Regardless of the profile selected, keep the runtime lookup
		# paths stable.  Otherwise, all the apps that were built with
		# a new compiler will start trying to use older versions of
		# the libs, and life gets sad.  We work off the assumption
		# that every shared library gcc ships is ABI compatible (as
		# is the point of SONAMEs).  We don't have to worry about
		# static libraries here as gcc itself will take care of
		# linking against its own internal paths first. #297685
		local MY_LDPATH
		MY_LDPATH=$(${SED} -n \
			-e '/^LDPATH=/{s|LDPATH=||;s|"||g;s|:|\n|g;p}' \
			$(version_sorted_paths "${GCC_ENV_D}"/${CHOST}-* | tac)
		)

		# Pass all by default
		awk '!/^(STDCXX_INCDIR|LDPATH|CC|CXX|CTARGET|GCCBITS|GCC_SPECS|GCC_PATH|MULTIOSDIRS)=/ {print $0}' \
			"${GCC_ENV_D}/${CC_COMP}" >> "${envd}.tmp"
		if [[ -d ${EROOT}/etc/ld.so.conf.d ]] ; then
			echo "${MY_LDPATH}" > "${EROOT}"/etc/ld.so.conf.d/05gcc-${CTARGET}.conf
		else
			echo "LDPATH=\"${MY_LDPATH}\"" >> "${envd}.tmp"
		fi

		# Punt old files; maybe globs too much, but oh well
		# 'NATIVE' and '.NATIVE' were used by gcc-wrapper before Aug 2018
		# and are not used as wrapper is removed.
		# '.NATIVE' was created before Sept 2019.
		# We clean up both for now. Should be safe to remove in 2021.
		rm -f \
			"${GCC_ENV_D}/NATIVE" "${GCC_ENV_D}/.NATIVE" \
			"${ENV_D}/05gcc" "${ENV_D}/05gcc-${CTARGET}" \
			"${ENV_D}/05gcc-${CTARGET}"-* "${GCC_ENV_D}/config-${CTARGET}"-*

		# Relocate random crap
		local x libdir pkgconfdir
		local mver=${CC_COMP_VERSION:0:3}
		for libdir in ${MULTIOSDIRS//:/ } ; do
			pkgconfdir="${EROOT}/usr/lib/${libdir}/pkgconfig"
			for x in "" "-${mver}" ; do
				x="${pkgconfdir}/libgcj${x}.pc"
				if [[ -e ${pkgconfdir}/libgcj-${CC_COMP_VERSION}.pc ]] ; then
					ln -sf libgcj-${CC_COMP_VERSION}.pc "${x}"
				else
					# Maybe we selected a version that lacks gcj support.
					rm -f "${x}"
				fi
			done
			# Clean out anything left over from older versions. #430932
			find "${pkgconfdir}"/libgcj*.pc -xtype l -delete 2>/dev/null
		done

		prefix_copy_gcc_libs
		handle_split_usr
		: $(( envd_changed += $? ))

		mv_if_diff "${envd}.tmp" "${envd}"
		: $(( envd_changed += $? ))
	else
		# cross-case
		# env.d file is empty since Aug 2018 and is cleaned up by
		# gcc-config since Sept 2019. Should be safe to remove in 2021.
		rm -f "${envd}.tmp" "${envd}"
	fi

	update_wrappers ${CTARGET}

	# Update LTO plugin for GCC.  Supported as of binutils 2.25.
	local BFD_PLUGINS_DIR
	local LIBLTO_PLUGIN
	LIBLTO_PLUGIN="${EROOT}usr/libexec/gcc/${CTARGET}/${CC_COMP_VERSION}/liblto_plugin.so"
	if is_cross_compiler; then
		BFD_PLUGINS_DIR="${EROOT}usr/${CHOST}/${CTARGET}/binutils-bin/lib/bfd-plugins"
	else
		BFD_PLUGINS_DIR="${EROOT}usr/${CHOST}/binutils-bin/lib/bfd-plugins"
	fi
	mkdir -p "${BFD_PLUGINS_DIR}"
	ln -sf "${LIBLTO_PLUGIN}" "${BFD_PLUGINS_DIR}"

	if [[ ${ROOT} == "/" ]] && \
	   [[ ${FORCE} == "yes" || ${envd_changed} -gt 0 ]]
	then
		# in case python is broken ...
		if ! env-update ; then
			echo ""
			ewarn "env-update failed to work properly; making sure ld.so.conf paths"
			ewarn "are setup properly.  Please rerun gcc-config with the -f option."
			echo ""
			if [[ -z ${EPREFIX} ]] ; then
				if [[ ! -d /etc/ld.so.conf.d ]] ; then
					show_var LDPATH "${ROOT}"/etc/env.d/05gcc-${CTARGET} \
						| ${SED} -e 's|:|\n|g' >> /etc/ld.so.conf
				fi
				ldconfig
			fi
		fi
	else
		envd_changed=0
	fi

	eend 0

	# This is needed mainly for MANPATH and INFOPATH updates.
	if [[ ${envd_changed} -ne 0 ]] ; then
		echo
		ewarn "If you intend to use the gcc from the new profile in an already"
		ewarn "running shell, please remember to do:"
		echo
		ewarn "  . ${EPREFIX}/etc/profile"
		echo
	fi

	return 0
}

get_current_profile() {
	local conf="${GCC_ENV_D}/config-${CTARGET}"
	if [[ ! -f ${conf} ]] ; then
		eerror "${argv0}: No gcc profile is active!"
		return 1
	fi

	source_var CURRENT "${conf}"

	if [[ -z ${CURRENT} ]] ; then
		eerror "${argv0}: No gcc profile is active!"
		return 1
	elif [[ ! -f ${GCC_ENV_D}/${CURRENT} ]] ; then
		eerror "${argv0}: Active gcc profile is invalid!"
		return 1
	fi

	echo "${CURRENT}"

	return 0
}

list_profiles() {
	local i=0
	local filter=

	if [[ ${ROOT} != "/" ]] ; then
		echo "Using gcc-config info in ${ROOT}"
	fi

	if [[ ! -f ${GCC_ENV_D}/config-${CTARGET} ]] ; then
		# get_current_profile already warns
		#eerror "${argv0}: No gcc profile is active; please select one!"
		filter=${CTARGET}
	fi

	source_var CURRENT "${GCC_ENV_D}"/config-${CTARGET}
	CURRENT_NATIVE=${CURRENT}
	local target=
	for x in $(version_sorted_paths "${GCC_ENV_D}"/*) ; do
		[[ -f ${x} ]] || continue
		[[ ${x} == */config* ]] && continue

		source_var CTARGET "${x}"
		# Older native profiles would not set CTARGET.
		if [[ -z ${CTARGET} ]] ; then
			if [[ ${x} == */${CHOST}-* ]] ; then
				CTARGET=${CHOST}
			else
				ewarn "broken config file: ${x}"
			fi
		fi

		((++i))

		[[ -n ${filter} ]] && [[ ${filter} != ${CTARGET} ]] && continue

		if [[ ${target} != ${CTARGET} ]] ; then
			[[ ${i} -gt 1 ]] && echo
			target=${CTARGET}
			CTARGET=""
		fi

		x=${x##*/}
		if [[ ${x} == ${CURRENT_NATIVE} ]] ; then
			x="${x} ${GOOD}*${NORMAL}"
		elif [[ -e ${GCC_ENV_D}/config-${target} ]] ; then
			source_profile "${GCC_ENV_D}/config-${target}"
			[[ ${x} == ${CURRENT} ]] && x="${x} ${HILITE}*${NORMAL}"
		fi
		echo " [${i}] ${x}"
	done
}

print_environ() {
	local ENV_CMD SET_ELEMENT
	case ${SHELL} in
		*/csh|*/tcsh)
			ENV_CMD="setenv"
			SET_ELEMENT=" "
			;;
		*)
			ENV_CMD="export"
			SET_ELEMENT="="
			;;
	esac

	local var
	for var in GCC_SPECS GCC_PATH ; do
		local ${var}
		source_var ${var} "${GCC_ENV_D}/${CC_COMP}"
	done

	(
	[[ -n ${GCC_PATH} ]] && PATH=${GCC_PATH}:${PATH}
	for var in PATH GCC_SPECS ; do
		echo "${ENV_CMD} ${var}${SET_ELEMENT}\"${!var}\""
	done
	)
}

get_bin_path() { show_var GCC_PATH "${GCC_ENV_D}/${CC_COMP}" ; }
get_lib_path() { show_var LDPATH "${GCC_ENV_D}/${CC_COMP}" ; }

split_gcc_ver() {
	# Split up the gcc profile into components:
	# TARGET-VER[-specs] -> TARGET VER [specs]
	# arm-linux-3.3.6 -> arm-linux 3.3.6
	# x86_64-linux-4.0.1-pre1234 -> x86_64-linux 4.0.1-pre1234
	# sh-linux-3.4.4-hardened -> sh-linux 3.4.4 hardened
	#
	# So below we will start at the end and run a small state machine ...
	# specs [3]
	#    accept everything
	# specs -> version transition [3->2]
	#    when we find a version component
	# version [2]
	#    accept only version components (see the regex)
	# version -> target transition [2->1]
	#    when we hit a non version component
	# target [1]
	#    accept everything we have left
	#
	echo "$@" | awk -F- '
	function pushit(onme, pushee) {
		return (onme == "" ? pushee : pushee"-"onme);
	}
	{
		state=3
		targ=""
		ver=""
		spec=""
		for (i=NF; i > 0; --i) {
			if (state >= 2) {
				if ($i ~ /^(alpha|beta|pre|rc|p)?[[:digit:].]+$/) {
					ver=pushit(ver, $i)
					state=2
				} else if (state == 3)
					spec=pushit(spec, $i)
				else
					state=1
			}
			if (state == 1)
				targ = pushit(targ, $i)
		}

		if (targ == "") {
			if (ver == "") {
				ver=spec
				spec=""
			}
			targ=ver
			ver=""
		}
		print targ " " ver (spec != "" ? " " spec : "")
	}'
}
chop_gcc_ver_spec() {
	local splitTED=$(split_gcc_ver "$@") # target ver spec
	splitTED=${splitTED#* }              # ver spec
	echo ${splitTED/ /-}                 # ver-spec
}

set_doit() {
	[[ -n ${DOIT} ]] && die "too many actions selected!"
	DOIT=$1
}
DOIT=""
FORCE="no"

CC_COMP=
ENV_D="${EROOT}etc/env.d"
GCC_ENV_D="${ENV_D}/gcc"
USE_NATIVE_LINKS="@USE_NATIVE_LINKS@"
USE_CC_WRAPPERS="@USE_CC_WRAPPERS@"

for x in "$@" ; do
	case "${x}" in
		# Only use specified compiler if one is not already selected.
		-O|--use-old)
			: ${CTARGET:=$(try_real_hard_to_find_CHOST)}
			if get_current_profile &>/dev/null ; then
				CC_COMP=$(get_current_profile)
			else
				die "No profile selected, unable to utilize --use-old"
			fi
			;;
		-f|--force)
			FORCE="yes"
			;;
		-c|--get-current-profile)
			set_doit get_current_profile
			;;
		-l|--list-profiles)
			set_doit list_profiles
			;;
		-S|--split-profile)
			if [[ ( $1 != "-S" && $1 != "--split-profile" ) || $# -eq 1 ]] ; then
				usage 1
			fi
			shift # push -S out
			for x in "$@" ; do
				split_gcc_ver ${x}
			done
			exit 0
			;;
		-E|--print-environ)
			set_doit print_environ
			;;
		-B|--get-bin-path)
			set_doit get_bin_path
			;;
		-L|--get-lib-path)
			set_doit get_lib_path
			;;
		-x|--debug)
			set -x
			;;
		-C|--nocolor)
			# nothing to do; functions.sh parsed this for us
			;;
		-h|--help)
			usage 0
			;;
		-V|--version)
			echo "${argv0}: @PV@"
			exit 0
			;;
		--enable-native-links)  USE_NATIVE_LINKS="yes" ;;
		--disable-native-links) USE_NATIVE_LINKS="no" ;;
		--enable-cc-wrappers)  USE_CC_WRAPPERS="yes" ;;
		--disable-cc-wrappers) USE_CC_WRAPPERS="no" ;;
		-*)
			die "Invalid switch!  Run ${argv0} without parameters for help."
			;;
		*)
			if [[ -n ${CC_COMP} ]] ; then
				die "Too many arguments!  Run ${argv0} without parameters for help."
			fi

			if [[ -z $(echo ${x} | tr -d '[:digit:]') ]] ; then
				# User gave us a # representing the profile
				i=1
				for y in $(version_sorted_paths "${GCC_ENV_D}"/*) ; do
					[[ -f ${y} ]] || continue
					[[ ${y} == */config* ]] && continue

					if [[ -f ${y} ]] && [[ ${x} == ${i} ]] ; then
						CC_COMP=${y##*/}
						break
					fi
					((++i))
				done
				if [[ -z ${CC_COMP} ]] ; then
					die "Could not locate profile #$x !"
				fi
			else
				# User gave us a full HOST-gccver
				x=${x##*/}
				if [[ ${DOIT} == "get_current_profile" && -z $(ls "${GCC_ENV_D}"/${x}-* 2>/dev/null) ]] || \
				   [[ ${DOIT} != "get_current_profile" && ! -f ${GCC_ENV_D}/${x} ]]
				then
					# Maybe they just gave us a gccver ...
					get_chost
					if [[ -f ${GCC_ENV_D}/${CHOST}-${x} ]] ; then
						x=${CHOST}-${x}
					else
						die "Could not locate '$x' in '${GCC_ENV_D}/' !"
					fi
				fi
				CC_COMP=${x}
			fi
			;;
	esac
done

[[ -z ${DOIT}${CC_COMP} ]] && usage 1
: ${DOIT:="switch_profile"}

get_chost
[[ ${DOIT} == "get_current_profile" ]] \
	&& : ${CTARGET:=${CC_COMP:-${CHOST}}} \
	|| : ${CTARGET:=${CHOST}}

if [[ -z ${CC_COMP} ]] ; then
	CC_COMP=$(get_current_profile)
	if [[ $? -ne 0 ]] ; then
		echo "${CC_COMP}"
		list_profiles
		exit 1
	fi
fi

if [[ ${DOIT} != "get_current_profile" ]] ; then
	GCC_LIB=$(
		get_lib_path | \
			${SED} -e "s|${EPREFIX:-/}/*|/|g" | \
			awk -F/ '{ print "/"$2"/"$3"/"$4"/" }'
	)

	# For people who insist on using funky version strings ("4.6.x"
	# rather than "4.6.2"), allow them to manually specify it.
	source_var GCC_VER "${GCC_ENV_D}/${CC_COMP}"

	CC_COMP_VERSION=${GCC_VER:-$(chop_gcc_ver_spec ${CC_COMP})}
	CC_COMP_TARGET=$(show_var CTARGET "${GCC_ENV_D}/${CC_COMP}")
	if [[ -z ${CC_COMP_TARGET} ]] ; then
		# Native configs don't have CTARGET in there.
		CC_COMP_TARGET=${CC_COMP%-${CC_COMP_VERSION}*}
	fi

	if [[ ! -d ${EROOT}/${GCC_LIB}/${CC_COMP_TARGET}/${CC_COMP_VERSION} ]] ; then
		CC_COMP_VERSION=${CC_COMP_VERSION%-*}
	fi

	if [[ ! -f ${GCC_ENV_D}/${CC_COMP} ]] ; then
		eerror "${argv0}: Profile '${GCC_ENV_D}/${CC_COMP}' does not exist" 1>&2
		#exit 1
	fi

	if [[ ! -d ${EROOT}/${GCC_LIB}/${CC_COMP_TARGET}/${CC_COMP_VERSION} ]] ; then
		eerror "${argv0}: Did not find compiler at '${EROOT}/${GCC_LIB}/${CC_COMP_TARGET}/${CC_COMP_VERSION}'" 1>&2
		#exit 1
	fi
fi

${DOIT}

# vim:ts=4