eclass/multilib: Sync with gentoo

It's from gentoo commit f64708850264e93cb54c8857d6eb459a4faf274e.

sdk_container/src/third_party/portage-stable/eclass/multilib.eclass

@@ -1,14 +1,20 @@
-# Copyright 1999-2015 Gentoo Foundation
+# Copyright 1999-2021 Gentoo Authors
 # Distributed under the terms of the GNU General Public License v2
 
 # @ECLASS: multilib.eclass
 # @MAINTAINER:
-# amd64@gentoo.org
 # toolchain@gentoo.org
+# @SUPPORTED_EAPIS: 5 6 7 8
 # @BLURB: This eclass is for all functions pertaining to handling multilib configurations.
 # @DESCRIPTION:
 # This eclass is for all functions pertaining to handling multilib configurations.
 
+case ${EAPI:-0} in
+	# EAPI=0 is still used by crossdev, bug #797367
+	0|5|6|7|8) ;;
+	*) die "${ECLASS}: EAPI ${EAPI:-0} not supported" ;;
+esac
+
 if [[ -z ${_MULTILIB_ECLASS} ]]; then
 _MULTILIB_ECLASS=1
 
@@ -48,7 +54,7 @@ has_multilib_profile() {
 #   fall back on old behavior.  Any profile that has these set should also
 #   depend on a newer version of portage (not yet released) which uses these
 #   over CONF_LIBDIR in econf, dolib, etc...
-if has "${EAPI:-0}" 0 1 2 3 4 5; then
+if [[ ${EAPI} == [05] ]] ; then
 	get_libdir() {
 		local CONF_LIBDIR
 		if [ -n  "${CONF_LIBDIR_OVERRIDE}" ] ; then
@@ -294,11 +300,22 @@ get_modname() {
 }
 
 # This is for the toolchain to setup profile variables when pulling in
-# a crosscompiler (and thus they aren't set in the profile)
+# a crosscompiler (and thus they aren't set in the profile).
 multilib_env() {
 	local CTARGET=${1:-${CTARGET}}
 	local cpu=${CTARGET%%*-}
 
+	if [[ ${CTARGET} = *-musl* ]]; then
+		# musl has no multilib support and can run only in 'lib':
+		# - https://bugs.gentoo.org/675954
+		# - https://gcc.gnu.org/PR90077
+		# - https://github.com/gentoo/musl/issues/245
+		: ${MULTILIB_ABIS=default}
+		: ${DEFAULT_ABI=default}
+		export MULTILIB_ABIS DEFAULT_ABI
+		return
+	fi
+
 	case ${cpu} in
 		aarch64*)
 			# Not possible to do multilib with aarch64 and a single toolchain.
@@ -386,19 +403,43 @@ multilib_env() {
 			: ${DEFAULT_ABI=ppc64}
 		;;
 		riscv64*)
-			export CFLAGS_lp64d=${CFLAGS_lp64d--mabi=lp64d}
+			export CFLAGS_lp64d=${CFLAGS_lp64d--mabi=lp64d -march=rv64imafdc}
 			export CHOST_lp64d=${CTARGET}
 			export CTARGET_lp64d=${CTARGET}
-			export LIBDIR_lp64d="lib64/lp64d"
+			export LIBDIR_lp64d=${LIBDIR_lp64d-lib64/lp64d}
 
-			export CFLAGS_lp64=${CFLAGS_lp64--mabi=lp64}
+			export CFLAGS_lp64=${CFLAGS_lp64--mabi=lp64 -march=rv64imac}
 			export CHOST_lp64=${CTARGET}
 			export CTARGET_lp64=${CTARGET}
-			export LIBDIR_lp64="lib64/lp64"
+			export LIBDIR_lp64=${LIBDIR_lp64-lib64/lp64}
 
-			: ${MULTILIB_ABIS=lp64d lp64}
+			export CFLAGS_ilp32d=${CFLAGS_ilp32d--mabi=ilp32d -march=rv32imafdc}
+			export CHOST_ilp32d=${CTARGET/riscv64/riscv32}
+			export CTARGET_ilp32d=${CTARGET/riscv64/riscv32}
+			export LIBDIR_ilp32d=${LIBDIR_ilp32d-lib32/ilp32d}
+
+			export CFLAGS_ilp32=${CFLAGS_ilp32--mabi=ilp32 -march=rv32imac}
+			export CHOST_ilp32=${CTARGET/riscv64/riscv32}
+			export CTARGET_ilp32=${CTARGET/riscv64/riscv32}
+			export LIBDIR_ilp32=${LIBDIR_ilp32-lib32/ilp32}
+
+			: ${MULTILIB_ABIS=lp64d lp64 ilp32d ilp32}
 			: ${DEFAULT_ABI=lp64d}
 		;;
+		riscv32*)
+			export CFLAGS_ilp32d=${CFLAGS_ilp32d--mabi=ilp32d}
+			export CHOST_ilp32d=${CTARGET}
+			export CTARGET_ilp32d=${CTARGET}
+			export LIBDIR_ilp32d=${LIBDIR_ilp32d-lib32/ilp32d}
+
+			export CFLAGS_ilp32=${CFLAGS_ilp32--mabi=ilp32 -march=rv32imac}
+			export CHOST_ilp32=${CTARGET}
+			export CTARGET_ilp32=${CTARGET}
+			export LIBDIR_ilp32=${LIBDIR_ilp32-lib32/ilp32}
+
+			: ${MULTILIB_ABIS=ilp32d ilp32}
+			: ${DEFAULT_ABI=ilp32d}
+		;;
 		s390x*)
 			export CFLAGS_s390=${CFLAGS_s390--m31} # the 31 is not a typo
 			export CHOST_s390=${CTARGET/s390x/s390}
@@ -445,9 +486,32 @@ multilib_toolchain_setup() {
 
 	export ABI=$1
 
+	local save_restore_variables=(
+		CBUILD
+		CHOST
+		AR
+		CC
+		CXX
+		F77
+		FC
+		LD
+		NM
+		OBJCOPY
+		OBJDUMP
+		PKG_CONFIG
+		RANLIB
+		READELF
+		STRINGS
+		STRIP
+		PKG_CONFIG_LIBDIR
+		PKG_CONFIG_PATH
+		PKG_CONFIG_SYSTEM_INCLUDE_PATH
+		PKG_CONFIG_SYSTEM_LIBRARY_PATH
+	)
+
 	# First restore any saved state we have laying around.
 	if [[ ${_DEFAULT_ABI_SAVED} == "true" ]] ; then
-		for v in CHOST CBUILD AS CC CXX F77 FC LD PKG_CONFIG_{LIBDIR,PATH} ; do
+		for v in "${save_restore_variables[@]}" ; do
 			vv="_abi_saved_${v}"
 			[[ ${!vv+set} == "set" ]] && export ${v}="${!vv}" || unset ${v}
 			unset ${vv}
@@ -455,11 +519,9 @@ multilib_toolchain_setup() {
 		unset _DEFAULT_ABI_SAVED
 	fi
 
-	# We want to avoid the behind-the-back magic of gcc-config as it
-	# screws up ccache and distcc.  See #196243 for more info.
 	if [[ ${ABI} != ${DEFAULT_ABI} ]] ; then
-		# Back that multilib-ass up so we can restore it later
+		# Backup multilib state so we can restore it later
-		for v in CHOST CBUILD AS CC CXX F77 FC LD PKG_CONFIG_{LIBDIR,PATH} ; do
+		for v in "${save_restore_variables[@]}" ; do
 			vv="_abi_saved_${v}"
 			[[ ${!v+set} == "set" ]] && export ${vv}="${!v}" || unset ${vv}
 		done
@@ -472,15 +534,30 @@ multilib_toolchain_setup() {
 
 		# Set the CHOST native first so that we pick up the native
 		# toolchain and not a cross-compiler by accident #202811.
+		#
+		# Make sure ${save_restore_variables[@]} list matches below.
 		export CHOST=$(get_abi_CHOST ${DEFAULT_ABI})
+
+		export AR="$(tc-getAR)" # Avoid 'ar', use '${CHOST}-ar'
 		export CC="$(tc-getCC) $(get_abi_CFLAGS)"
 		export CXX="$(tc-getCXX) $(get_abi_CFLAGS)"
 		export F77="$(tc-getF77) $(get_abi_CFLAGS)"
 		export FC="$(tc-getFC) $(get_abi_CFLAGS)"
 		export LD="$(tc-getLD) $(get_abi_LDFLAGS)"
+		export NM="$(tc-getNM)" # Avoid 'nm', use '${CHOST}-nm'
+		export OBJCOPY="$(tc-getOBJCOPY)" # Avoid 'objcopy', use '${CHOST}-objcopy'
+		export OBJDUMP="$(tc-getOBJDUMP)" # Avoid 'objdump', use '${CHOST}-objdump'
+		export PKG_CONFIG="$(tc-getPKG_CONFIG)"
+		export RANLIB="$(tc-getRANLIB)" # Avoid 'ranlib', use '${CHOST}-ranlib'
+		export READELF="$(tc-getREADELF)" # Avoid 'readelf', use '${CHOST}-readelf'
+		export STRINGS="$(tc-getSTRINGS)" # Avoid 'strings', use '${CHOST}-strings'
+		export STRIP="$(tc-getSTRIP)" # Avoid 'strip', use '${CHOST}-strip'
+
 		export CHOST=$(get_abi_CHOST $1)
 		export PKG_CONFIG_LIBDIR=${EPREFIX}/usr/$(get_libdir)/pkgconfig
 		export PKG_CONFIG_PATH=${EPREFIX}/usr/share/pkgconfig
+		export PKG_CONFIG_SYSTEM_INCLUDE_PATH=${EPREFIX}/usr/include
+		export PKG_CONFIG_SYSTEM_LIBRARY_PATH=${EPREFIX}/$(get_libdir):${EPREFIX}/usr/$(get_libdir)
 	fi
 }