scripts: config.guess: update to 2021-05-24

This script hasn't seen an update in multiple years, update it to the
latest version provided upstream. Both `config.guess` and `config.sub`
are copied from upstream[1] and not modified.

The full changelog is available within the upstream repository[1].

[1]: https://git.savannah.gnu.org/git/config.git

Signed-off-by: Paul Spooren <mail@aparcar.org>

2 files changed, 788 insertions, 498 deletions

diff --git a/scripts/config.guess b/scripts/config.guess
index 18f8edc0ff..dc0a6b2997 100755
--- a/scripts/config.guess
+++ b/scripts/config.guess
@@ -1,8 +1,8 @@
 #! /bin/sh
 # Attempt to guess a canonical system name.
-#   Copyright 1992-2018 Free Software Foundation, Inc.
+#   Copyright 1992-2021 Free Software Foundation, Inc.
 
-timestamp='2018-08-29'
+timestamp='2021-05-24'
 
 # This file is free software; you can redistribute it and/or modify it
 # under the terms of the GNU General Public License as published by
@@ -27,12 +27,12 @@ timestamp='2018-08-29'
 # Originally written by Per Bothner; maintained since 2000 by Ben Elliston.
 #
 # You can get the latest version of this script from:
-# https://git.savannah.gnu.org/gitweb/?p=config.git;a=blob_plain;f=config.guess
+# https://git.savannah.gnu.org/cgit/config.git/plain/config.guess
 #
 # Please send patches to <config-patches@gnu.org>.
 
 
-me=`echo "$0" | sed -e 's,.*/,,'`
+me=$(echo "$0" | sed -e 's,.*/,,')
 
 usage="\
 Usage: $0 [OPTION]
@@ -50,7 +50,7 @@ version="\
 GNU config.guess ($timestamp)
 
 Originally written by Per Bothner.
-Copyright 1992-2018 Free Software Foundation, Inc.
+Copyright 1992-2021 Free Software Foundation, Inc.
 
 This is free software; see the source for copying conditions.  There is NO
 warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE."
@@ -96,13 +96,14 @@ fi
 
 tmp=
 # shellcheck disable=SC2172
-trap 'test -z "$tmp" || rm -fr "$tmp"' 1 2 13 15
-trap 'exitcode=$?; test -z "$tmp" || rm -fr "$tmp"; exit $exitcode' 0
+trap 'test -z "$tmp" || rm -fr "$tmp"' 0 1 2 13 15
 
 set_cc_for_build() {
+    # prevent multiple calls if $tmp is already set
+    test "$tmp" && return 0
     : "${TMPDIR=/tmp}"
     # shellcheck disable=SC2039
-    { tmp=`(umask 077 && mktemp -d "$TMPDIR/cgXXXXXX") 2>/dev/null` && test -n "$tmp" && test -d "$tmp" ; } ||
+    { tmp=$( (umask 077 && mktemp -d "$TMPDIR/cgXXXXXX") 2>/dev/null) && test -n "$tmp" && test -d "$tmp" ; } ||
 	{ test -n "$RANDOM" && tmp=$TMPDIR/cg$$-$RANDOM && (umask 077 && mkdir "$tmp" 2>/dev/null) ; } ||
 	{ tmp=$TMPDIR/cg-$$ && (umask 077 && mkdir "$tmp" 2>/dev/null) && echo "Warning: creating insecure temp directory" >&2 ; } ||
 	{ echo "$me: cannot create a temporary directory in $TMPDIR" >&2 ; exit 1 ; }
@@ -130,16 +131,14 @@ if test -f /.attbin/uname ; then
 	PATH=$PATH:/.attbin ; export PATH
 fi
 
-UNAME_MACHINE=`(uname -m) 2>/dev/null` || UNAME_MACHINE=unknown
-UNAME_RELEASE=`(uname -r) 2>/dev/null` || UNAME_RELEASE=unknown
-UNAME_SYSTEM=`(uname -s) 2>/dev/null`  || UNAME_SYSTEM=unknown
-UNAME_VERSION=`(uname -v) 2>/dev/null` || UNAME_VERSION=unknown
+UNAME_MACHINE=$( (uname -m) 2>/dev/null) || UNAME_MACHINE=unknown
+UNAME_RELEASE=$( (uname -r) 2>/dev/null) || UNAME_RELEASE=unknown
+UNAME_SYSTEM=$( (uname -s) 2>/dev/null) || UNAME_SYSTEM=unknown
+UNAME_VERSION=$( (uname -v) 2>/dev/null) || UNAME_VERSION=unknown
 
-case "$UNAME_SYSTEM" in
+case $UNAME_SYSTEM in
 Linux|GNU|GNU/*)
-	# If the system lacks a compiler, then just pick glibc.
-	# We could probably try harder.
-	LIBC=gnu
+	LIBC=unknown
 
 	set_cc_for_build
 	cat <<-EOF > "$dummy.c"
@@ -148,24 +147,36 @@ Linux|GNU|GNU/*)
 	LIBC=uclibc
 	#elif defined(__dietlibc__)
 	LIBC=dietlibc
-	#else
+	#elif defined(__GLIBC__)
 	LIBC=gnu
+	#else
+	#include <stdarg.h>
+	/* First heuristic to detect musl libc.  */
+	#ifdef __DEFINED_va_list
+	LIBC=musl
+	#endif
 	#endif
 	EOF
-	eval "`$CC_FOR_BUILD -E "$dummy.c" 2>/dev/null | grep '^LIBC' | sed 's, ,,g'`"
+	eval "$($CC_FOR_BUILD -E "$dummy.c" 2>/dev/null | grep '^LIBC' | sed 's, ,,g')"
 
-	# If ldd exists, use it to detect musl libc.
-	if command -v ldd >/dev/null && \
-		ldd --version 2>&1 | grep -q ^musl
-	then
-	    LIBC=musl
+	# Second heuristic to detect musl libc.
+	if [ "$LIBC" = unknown ] &&
+	   command -v ldd >/dev/null &&
+	   ldd --version 2>&1 | grep -q ^musl; then
+		LIBC=musl
+	fi
+
+	# If the system lacks a compiler, then just pick glibc.
+	# We could probably try harder.
+	if [ "$LIBC" = unknown ]; then
+		LIBC=gnu
 	fi
 	;;
 esac
 
 # Note: order is significant - the case branches are not exclusive.
 
-case "$UNAME_MACHINE:$UNAME_SYSTEM:$UNAME_RELEASE:$UNAME_VERSION" in
+case $UNAME_MACHINE:$UNAME_SYSTEM:$UNAME_RELEASE:$UNAME_VERSION in
     *:NetBSD:*:*)
 	# NetBSD (nbsd) targets should (where applicable) match one or
 	# more of the tuples: *-*-netbsdelf*, *-*-netbsdaout*,
@@ -177,27 +188,27 @@ case "$UNAME_MACHINE:$UNAME_SYSTEM:$UNAME_RELEASE:$UNAME_VERSION" in
 	#
 	# Note: NetBSD doesn't particularly care about the vendor
 	# portion of the name.  We always set it to "unknown".
-	sysctl="sysctl -n hw.machine_arch"
-	UNAME_MACHINE_ARCH=`(uname -p 2>/dev/null || \
-	    "/sbin/$sysctl" 2>/dev/null || \
-	    "/usr/sbin/$sysctl" 2>/dev/null || \
-	    echo unknown)`
-	case "$UNAME_MACHINE_ARCH" in
+	UNAME_MACHINE_ARCH=$( (uname -p 2>/dev/null || \
+	    /sbin/sysctl -n hw.machine_arch 2>/dev/null || \
+	    /usr/sbin/sysctl -n hw.machine_arch 2>/dev/null || \
+	    echo unknown))
+	case $UNAME_MACHINE_ARCH in
+	    aarch64eb) machine=aarch64_be-unknown ;;
 	    armeb) machine=armeb-unknown ;;
 	    arm*) machine=arm-unknown ;;
 	    sh3el) machine=shl-unknown ;;
 	    sh3eb) machine=sh-unknown ;;
 	    sh5el) machine=sh5le-unknown ;;
 	    earmv*)
-		arch=`echo "$UNAME_MACHINE_ARCH" | sed -e 's,^e\(armv[0-9]\).*$,\1,'`
-		endian=`echo "$UNAME_MACHINE_ARCH" | sed -ne 's,^.*\(eb\)$,\1,p'`
+		arch=$(echo "$UNAME_MACHINE_ARCH" | sed -e 's,^e\(armv[0-9]\).*$,\1,')
+		endian=$(echo "$UNAME_MACHINE_ARCH" | sed -ne 's,^.*\(eb\)$,\1,p')
 		machine="${arch}${endian}"-unknown
 		;;
 	    *) machine="$UNAME_MACHINE_ARCH"-unknown ;;
 	esac
 	# The Operating System including object format, if it has switched
 	# to ELF recently (or will in the future) and ABI.
-	case "$UNAME_MACHINE_ARCH" in
+	case $UNAME_MACHINE_ARCH in
 	    earm*)
 		os=netbsdelf
 		;;
@@ -218,10 +229,10 @@ case "$UNAME_MACHINE:$UNAME_SYSTEM:$UNAME_RELEASE:$UNAME_VERSION" in
 		;;
 	esac
 	# Determine ABI tags.
-	case "$UNAME_MACHINE_ARCH" in
+	case $UNAME_MACHINE_ARCH in
 	    earm*)
 		expr='s/^earmv[0-9]/-eabi/;s/eb$//'
-		abi=`echo "$UNAME_MACHINE_ARCH" | sed -e "$expr"`
+		abi=$(echo "$UNAME_MACHINE_ARCH" | sed -e "$expr")
 		;;
 	esac
 	# The OS release
@@ -229,12 +240,12 @@ case "$UNAME_MACHINE:$UNAME_SYSTEM:$UNAME_RELEASE:$UNAME_VERSION" in
 	# thus, need a distinct triplet. However, they do not need
 	# kernel version information, so it can be replaced with a
 	# suitable tag, in the style of linux-gnu.
-	case "$UNAME_VERSION" in
+	case $UNAME_VERSION in
 	    Debian*)
 		release='-gnu'
 		;;
 	    *)
-		release=`echo "$UNAME_RELEASE" | sed -e 's/[-_].*//' | cut -d. -f1,2`
+		release=$(echo "$UNAME_RELEASE" | sed -e 's/[-_].*//' | cut -d. -f1,2)
 		;;
 	esac
 	# Since CPU_TYPE-MANUFACTURER-KERNEL-OPERATING_SYSTEM:
@@ -243,15 +254,19 @@ case "$UNAME_MACHINE:$UNAME_SYSTEM:$UNAME_RELEASE:$UNAME_VERSION" in
 	echo "$machine-${os}${release}${abi-}"
 	exit ;;
     *:Bitrig:*:*)
-	UNAME_MACHINE_ARCH=`arch | sed 's/Bitrig.//'`
+	UNAME_MACHINE_ARCH=$(arch | sed 's/Bitrig.//')
 	echo "$UNAME_MACHINE_ARCH"-unknown-bitrig"$UNAME_RELEASE"
 	exit ;;
     *:OpenBSD:*:*)
-	UNAME_MACHINE_ARCH=`arch | sed 's/OpenBSD.//'`
+	UNAME_MACHINE_ARCH=$(arch | sed 's/OpenBSD.//')
 	echo "$UNAME_MACHINE_ARCH"-unknown-openbsd"$UNAME_RELEASE"
 	exit ;;
+    *:SecBSD:*:*)
+	UNAME_MACHINE_ARCH=$(arch | sed 's/SecBSD.//')
+	echo "$UNAME_MACHINE_ARCH"-unknown-secbsd"$UNAME_RELEASE"
+	exit ;;
     *:LibertyBSD:*:*)
-	UNAME_MACHINE_ARCH=`arch | sed 's/^.*BSD\.//'`
+	UNAME_MACHINE_ARCH=$(arch | sed 's/^.*BSD\.//')
 	echo "$UNAME_MACHINE_ARCH"-unknown-libertybsd"$UNAME_RELEASE"
 	exit ;;
     *:MidnightBSD:*:*)
@@ -263,6 +278,9 @@ case "$UNAME_MACHINE:$UNAME_SYSTEM:$UNAME_RELEASE:$UNAME_VERSION" in
     *:SolidBSD:*:*)
 	echo "$UNAME_MACHINE"-unknown-solidbsd"$UNAME_RELEASE"
 	exit ;;
+    *:OS108:*:*)
+	echo "$UNAME_MACHINE"-unknown-os108_"$UNAME_RELEASE"
+	exit ;;
     macppc:MirBSD:*:*)
 	echo powerpc-unknown-mirbsd"$UNAME_RELEASE"
 	exit ;;
@@ -272,27 +290,32 @@ case "$UNAME_MACHINE:$UNAME_SYSTEM:$UNAME_RELEASE:$UNAME_VERSION" in
     *:Sortix:*:*)
 	echo "$UNAME_MACHINE"-unknown-sortix
 	exit ;;
+    *:Twizzler:*:*)
+	echo "$UNAME_MACHINE"-unknown-twizzler
+	exit ;;
     *:Redox:*:*)
 	echo "$UNAME_MACHINE"-unknown-redox
 	exit ;;
     mips:OSF1:*.*)
-        echo mips-dec-osf1
-        exit ;;
+	echo mips-dec-osf1
+	exit ;;
     alpha:OSF1:*:*)
+	# Reset EXIT trap before exiting to avoid spurious non-zero exit code.
+	trap '' 0
 	case $UNAME_RELEASE in
 	*4.0)
-		UNAME_RELEASE=`/usr/sbin/sizer -v | awk '{print $3}'`
+		UNAME_RELEASE=$(/usr/sbin/sizer -v | awk '{print $3}')
 		;;
 	*5.*)
-		UNAME_RELEASE=`/usr/sbin/sizer -v | awk '{print $4}'`
+		UNAME_RELEASE=$(/usr/sbin/sizer -v | awk '{print $4}')
 		;;
 	esac
 	# According to Compaq, /usr/sbin/psrinfo has been available on
 	# OSF/1 and Tru64 systems produced since 1995.  I hope that
 	# covers most systems running today.  This code pipes the CPU
 	# types through head -n 1, so we only detect the type of CPU 0.
-	ALPHA_CPU_TYPE=`/usr/sbin/psrinfo -v | sed -n -e 's/^  The alpha \(.*\) processor.*$/\1/p' | head -n 1`
-	case "$ALPHA_CPU_TYPE" in
+	ALPHA_CPU_TYPE=$(/usr/sbin/psrinfo -v | sed -n -e 's/^  The alpha \(.*\) processor.*$/\1/p' | head -n 1)
+	case $ALPHA_CPU_TYPE in
 	    "EV4 (21064)")
 		UNAME_MACHINE=alpha ;;
 	    "EV4.5 (21064)")
@@ -329,11 +352,8 @@ case "$UNAME_MACHINE:$UNAME_SYSTEM:$UNAME_RELEASE:$UNAME_VERSION" in
 	# A Tn.n version is a released field test version.
 	# A Xn.n version is an unreleased experimental baselevel.
 	# 1.2 uses "1.2" for uname -r.
-	echo "$UNAME_MACHINE"-dec-osf"`echo "$UNAME_RELEASE" | sed -e 's/^[PVTX]//' | tr ABCDEFGHIJKLMNOPQRSTUVWXYZ abcdefghijklmnopqrstuvwxyz`"
-	# Reset EXIT trap before exiting to avoid spurious non-zero exit code.
-	exitcode=$?
-	trap '' 0
-	exit $exitcode ;;
+	echo "$UNAME_MACHINE"-dec-osf"$(echo "$UNAME_RELEASE" | sed -e 's/^[PVTX]//' | tr ABCDEFGHIJKLMNOPQRSTUVWXYZ abcdefghijklmnopqrstuvwxyz)"
+	exit ;;
     Amiga*:UNIX_System_V:4.0:*)
 	echo m68k-unknown-sysv4
 	exit ;;
@@ -363,7 +383,7 @@ case "$UNAME_MACHINE:$UNAME_SYSTEM:$UNAME_RELEASE:$UNAME_VERSION" in
 	exit ;;
     Pyramid*:OSx*:*:* | MIS*:OSx*:*:* | MIS*:SMP_DC-OSx*:*:*)
 	# akee@wpdis03.wpafb.af.mil (Earle F. Ake) contributed MIS and NILE.
-	if test "`(/bin/universe) 2>/dev/null`" = att ; then
+	if test "$( (/bin/universe) 2>/dev/null)" = att ; then
 		echo pyramid-pyramid-sysv3
 	else
 		echo pyramid-pyramid-bsd
@@ -376,54 +396,59 @@ case "$UNAME_MACHINE:$UNAME_SYSTEM:$UNAME_RELEASE:$UNAME_VERSION" in
 	echo sparc-icl-nx6
 	exit ;;
     DRS?6000:UNIX_SV:4.2*:7* | DRS?6000:isis:4.2*:7*)
-	case `/usr/bin/uname -p` in
+	case $(/usr/bin/uname -p) in
 	    sparc) echo sparc-icl-nx7; exit ;;
 	esac ;;
     s390x:SunOS:*:*)
-	echo "$UNAME_MACHINE"-ibm-solaris2"`echo "$UNAME_RELEASE" | sed -e 's/[^.]*//'`"
+	echo "$UNAME_MACHINE"-ibm-solaris2"$(echo "$UNAME_RELEASE" | sed -e 's/[^.]*//')"
 	exit ;;
     sun4H:SunOS:5.*:*)
-	echo sparc-hal-solaris2"`echo "$UNAME_RELEASE"|sed -e 's/[^.]*//'`"
+	echo sparc-hal-solaris2"$(echo "$UNAME_RELEASE"|sed -e 's/[^.]*//')"
 	exit ;;
     sun4*:SunOS:5.*:* | tadpole*:SunOS:5.*:*)
-	echo sparc-sun-solaris2"`echo "$UNAME_RELEASE" | sed -e 's/[^.]*//'`"
+	echo sparc-sun-solaris2"$(echo "$UNAME_RELEASE" | sed -e 's/[^.]*//')"
 	exit ;;
     i86pc:AuroraUX:5.*:* | i86xen:AuroraUX:5.*:*)
 	echo i386-pc-auroraux"$UNAME_RELEASE"
 	exit ;;
     i86pc:SunOS:5.*:* | i86xen:SunOS:5.*:*)
-	UNAME_REL="`echo "$UNAME_RELEASE" | sed -e 's/[^.]*//'`"
-	case `isainfo -b` in
-	    32)
-		echo i386-pc-solaris2"$UNAME_REL"
-		;;
-	    64)
-		echo x86_64-pc-solaris2"$UNAME_REL"
-		;;
-	esac
+	set_cc_for_build
+	SUN_ARCH=i386
+	# If there is a compiler, see if it is configured for 64-bit objects.
+	# Note that the Sun cc does not turn __LP64__ into 1 like gcc does.
+	# This test works for both compilers.
+	if test "$CC_FOR_BUILD" != no_compiler_found; then
+	    if (echo '#ifdef __amd64'; echo IS_64BIT_ARCH; echo '#endif') | \
+		(CCOPTS="" $CC_FOR_BUILD -E - 2>/dev/null) | \
+		grep IS_64BIT_ARCH >/dev/null
+	    then
+		SUN_ARCH=x86_64
+	    fi
+	fi
+	echo "$SUN_ARCH"-pc-solaris2"$(echo "$UNAME_RELEASE"|sed -e 's/[^.]*//')"
 	exit ;;
     sun4*:SunOS:6*:*)
 	# According to config.sub, this is the proper way to canonicalize
 	# SunOS6.  Hard to guess exactly what SunOS6 will be like, but
 	# it's likely to be more like Solaris than SunOS4.
-	echo sparc-sun-solaris3"`echo "$UNAME_RELEASE"|sed -e 's/[^.]*//'`"
+	echo sparc-sun-solaris3"$(echo "$UNAME_RELEASE"|sed -e 's/[^.]*//')"
 	exit ;;
     sun4*:SunOS:*:*)
-	case "`/usr/bin/arch -k`" in
+	case $(/usr/bin/arch -k) in
 	    Series*|S4*)
-		UNAME_RELEASE=`uname -v`
+		UNAME_RELEASE=$(uname -v)
 		;;
 	esac
 	# Japanese Language versions have a version number like `4.1.3-JL'.
-	echo sparc-sun-sunos"`echo "$UNAME_RELEASE"|sed -e 's/-/_/'`"
+	echo sparc-sun-sunos"$(echo "$UNAME_RELEASE"|sed -e 's/-/_/')"
 	exit ;;
     sun3*:SunOS:*:*)
 	echo m68k-sun-sunos"$UNAME_RELEASE"
 	exit ;;
     sun*:*:4.2BSD:*)
-	UNAME_RELEASE=`(sed 1q /etc/motd | awk '{print substr($5,1,3)}') 2>/dev/null`
+	UNAME_RELEASE=$( (sed 1q /etc/motd | awk '{print substr($5,1,3)}') 2>/dev/null)
 	test "x$UNAME_RELEASE" = x && UNAME_RELEASE=3
-	case "`/bin/arch`" in
+	case $(/bin/arch) in
 	    sun3)
 		echo m68k-sun-sunos"$UNAME_RELEASE"
 		;;
@@ -503,8 +528,8 @@ case "$UNAME_MACHINE:$UNAME_SYSTEM:$UNAME_RELEASE:$UNAME_VERSION" in
 	}
 EOF
 	$CC_FOR_BUILD -o "$dummy" "$dummy.c" &&
-	  dummyarg=`echo "$UNAME_RELEASE" | sed -n 's/\([0-9]*\).*/\1/p'` &&
-	  SYSTEM_NAME=`"$dummy" "$dummyarg"` &&
+	  dummyarg=$(echo "$UNAME_RELEASE" | sed -n 's/\([0-9]*\).*/\1/p') &&
+	  SYSTEM_NAME=$("$dummy" "$dummyarg") &&
 	    { echo "$SYSTEM_NAME"; exit; }
 	echo mips-mips-riscos"$UNAME_RELEASE"
 	exit ;;
@@ -531,11 +556,11 @@ EOF
 	exit ;;
     AViiON:dgux:*:*)
 	# DG/UX returns AViiON for all architectures
-	UNAME_PROCESSOR=`/usr/bin/uname -p`
-	if [ "$UNAME_PROCESSOR" = mc88100 ] || [ "$UNAME_PROCESSOR" = mc88110 ]
+	UNAME_PROCESSOR=$(/usr/bin/uname -p)
+	if test "$UNAME_PROCESSOR" = mc88100 || test "$UNAME_PROCESSOR" = mc88110
 	then
-	    if [ "$TARGET_BINARY_INTERFACE"x = m88kdguxelfx ] || \
-	       [ "$TARGET_BINARY_INTERFACE"x = x ]
+	    if test "$TARGET_BINARY_INTERFACE"x = m88kdguxelfx || \
+	       test "$TARGET_BINARY_INTERFACE"x = x
 	    then
 		echo m88k-dg-dgux"$UNAME_RELEASE"
 	    else
@@ -559,17 +584,17 @@ EOF
 	echo m68k-tektronix-bsd
 	exit ;;
     *:IRIX*:*:*)
-	echo mips-sgi-irix"`echo "$UNAME_RELEASE"|sed -e 's/-/_/g'`"
+	echo mips-sgi-irix"$(echo "$UNAME_RELEASE"|sed -e 's/-/_/g')"
 	exit ;;
     ????????:AIX?:[12].1:2)   # AIX 2.2.1 or AIX 2.1.1 is RT/PC AIX.
 	echo romp-ibm-aix     # uname -m gives an 8 hex-code CPU id
-	exit ;;               # Note that: echo "'`uname -s`'" gives 'AIX '
+	exit ;;               # Note that: echo "'$(uname -s)'" gives 'AIX '
     i*86:AIX:*:*)
 	echo i386-ibm-aix
 	exit ;;
     ia64:AIX:*:*)
-	if [ -x /usr/bin/oslevel ] ; then
-		IBM_REV=`/usr/bin/oslevel`
+	if test -x /usr/bin/oslevel ; then
+		IBM_REV=$(/usr/bin/oslevel)
 	else
 		IBM_REV="$UNAME_VERSION.$UNAME_RELEASE"
 	fi
@@ -589,7 +614,7 @@ EOF
 			exit(0);
 			}
 EOF
-		if $CC_FOR_BUILD -o "$dummy" "$dummy.c" && SYSTEM_NAME=`"$dummy"`
+		if $CC_FOR_BUILD -o "$dummy" "$dummy.c" && SYSTEM_NAME=$("$dummy")
 		then
 			echo "$SYSTEM_NAME"
 		else
@@ -602,15 +627,15 @@ EOF
 	fi
 	exit ;;
     *:AIX:*:[4567])
-	IBM_CPU_ID=`/usr/sbin/lsdev -C -c processor -S available | sed 1q | awk '{ print $1 }'`
+	IBM_CPU_ID=$(/usr/sbin/lsdev -C -c processor -S available | sed 1q | awk '{ print $1 }')
 	if /usr/sbin/lsattr -El "$IBM_CPU_ID" | grep ' POWER' >/dev/null 2>&1; then
 		IBM_ARCH=rs6000
 	else
 		IBM_ARCH=powerpc
 	fi
-	if [ -x /usr/bin/lslpp ] ; then
-		IBM_REV=`/usr/bin/lslpp -Lqc bos.rte.libc |
-			   awk -F: '{ print $3 }' | sed s/[0-9]*$/0/`
+	if test -x /usr/bin/lslpp ; then
+		IBM_REV=$(/usr/bin/lslpp -Lqc bos.rte.libc |
+			   awk -F: '{ print $3 }' | sed s/[0-9]*$/0/)
 	else
 		IBM_REV="$UNAME_VERSION.$UNAME_RELEASE"
 	fi
@@ -638,26 +663,26 @@ EOF
 	echo m68k-hp-bsd4.4
 	exit ;;
     9000/[34678]??:HP-UX:*:*)
-	HPUX_REV=`echo "$UNAME_RELEASE"|sed -e 's/[^.]*.[0B]*//'`
-	case "$UNAME_MACHINE" in
+	HPUX_REV=$(echo "$UNAME_RELEASE"|sed -e 's/[^.]*.[0B]*//')
+	case $UNAME_MACHINE in
 	    9000/31?)            HP_ARCH=m68000 ;;
 	    9000/[34]??)         HP_ARCH=m68k ;;
 	    9000/[678][0-9][0-9])
-		if [ -x /usr/bin/getconf ]; then
-		    sc_cpu_version=`/usr/bin/getconf SC_CPU_VERSION 2>/dev/null`
-		    sc_kernel_bits=`/usr/bin/getconf SC_KERNEL_BITS 2>/dev/null`
-		    case "$sc_cpu_version" in
+		if test -x /usr/bin/getconf; then
+		    sc_cpu_version=$(/usr/bin/getconf SC_CPU_VERSION 2>/dev/null)
+		    sc_kernel_bits=$(/usr/bin/getconf SC_KERNEL_BITS 2>/dev/null)
+		    case $sc_cpu_version in
 		      523) HP_ARCH=hppa1.0 ;; # CPU_PA_RISC1_0
 		      528) HP_ARCH=hppa1.1 ;; # CPU_PA_RISC1_1
 		      532)                      # CPU_PA_RISC2_0
-			case "$sc_kernel_bits" in
+			case $sc_kernel_bits in
 			  32) HP_ARCH=hppa2.0n ;;
 			  64) HP_ARCH=hppa2.0w ;;
 			  '') HP_ARCH=hppa2.0 ;;   # HP-UX 10.20
 			esac ;;
 		    esac
 		fi
-		if [ "$HP_ARCH" = "" ]; then
+		if test "$HP_ARCH" = ""; then
 		    set_cc_for_build
 		    sed 's/^		//' << EOF > "$dummy.c"
 
@@ -692,11 +717,11 @@ EOF
 		    exit (0);
 		}
 EOF
-		    (CCOPTS="" $CC_FOR_BUILD -o "$dummy" "$dummy.c" 2>/dev/null) && HP_ARCH=`"$dummy"`
+		    (CCOPTS="" $CC_FOR_BUILD -o "$dummy" "$dummy.c" 2>/dev/null) && HP_ARCH=$("$dummy")
 		    test -z "$HP_ARCH" && HP_ARCH=hppa
 		fi ;;
 	esac
-	if [ "$HP_ARCH" = hppa2.0w ]
+	if test "$HP_ARCH" = hppa2.0w
 	then
 	    set_cc_for_build
 
@@ -720,7 +745,7 @@ EOF
 	echo "$HP_ARCH"-hp-hpux"$HPUX_REV"
 	exit ;;
     ia64:HP-UX:*:*)
-	HPUX_REV=`echo "$UNAME_RELEASE"|sed -e 's/[^.]*.[0B]*//'`
+	HPUX_REV=$(echo "$UNAME_RELEASE"|sed -e 's/[^.]*.[0B]*//')
 	echo ia64-hp-hpux"$HPUX_REV"
 	exit ;;
     3050*:HI-UX:*:*)
@@ -750,7 +775,7 @@ EOF
 	  exit (0);
 	}
 EOF
-	$CC_FOR_BUILD -o "$dummy" "$dummy.c" && SYSTEM_NAME=`"$dummy"` &&
+	$CC_FOR_BUILD -o "$dummy" "$dummy.c" && SYSTEM_NAME=$("$dummy") &&
 		{ echo "$SYSTEM_NAME"; exit; }
 	echo unknown-hitachi-hiuxwe2
 	exit ;;
@@ -770,7 +795,7 @@ EOF
 	echo hppa1.0-hp-osf
 	exit ;;
     i*86:OSF1:*:*)
-	if [ -x /usr/sbin/sysversion ] ; then
+	if test -x /usr/sbin/sysversion ; then
 	    echo "$UNAME_MACHINE"-unknown-osf1mk
 	else
 	    echo "$UNAME_MACHINE"-unknown-osf1
@@ -819,14 +844,14 @@ EOF
 	echo craynv-cray-unicosmp"$UNAME_RELEASE" | sed -e 's/\.[^.]*$/.X/'
 	exit ;;
     F30[01]:UNIX_System_V:*:* | F700:UNIX_System_V:*:*)
-	FUJITSU_PROC=`uname -m | tr ABCDEFGHIJKLMNOPQRSTUVWXYZ abcdefghijklmnopqrstuvwxyz`
-	FUJITSU_SYS=`uname -p | tr ABCDEFGHIJKLMNOPQRSTUVWXYZ abcdefghijklmnopqrstuvwxyz | sed -e 's/\///'`
-	FUJITSU_REL=`echo "$UNAME_RELEASE" | sed -e 's/ /_/'`
+	FUJITSU_PROC=$(uname -m | tr ABCDEFGHIJKLMNOPQRSTUVWXYZ abcdefghijklmnopqrstuvwxyz)
+	FUJITSU_SYS=$(uname -p | tr ABCDEFGHIJKLMNOPQRSTUVWXYZ abcdefghijklmnopqrstuvwxyz | sed -e 's/\///')
+	FUJITSU_REL=$(echo "$UNAME_RELEASE" | sed -e 's/ /_/')
 	echo "${FUJITSU_PROC}-fujitsu-${FUJITSU_SYS}${FUJITSU_REL}"
 	exit ;;
     5000:UNIX_System_V:4.*:*)
-	FUJITSU_SYS=`uname -p | tr ABCDEFGHIJKLMNOPQRSTUVWXYZ abcdefghijklmnopqrstuvwxyz | sed -e 's/\///'`
-	FUJITSU_REL=`echo "$UNAME_RELEASE" | tr ABCDEFGHIJKLMNOPQRSTUVWXYZ abcdefghijklmnopqrstuvwxyz | sed -e 's/ /_/'`
+	FUJITSU_SYS=$(uname -p | tr ABCDEFGHIJKLMNOPQRSTUVWXYZ abcdefghijklmnopqrstuvwxyz | sed -e 's/\///')
+	FUJITSU_REL=$(echo "$UNAME_RELEASE" | tr ABCDEFGHIJKLMNOPQRSTUVWXYZ abcdefghijklmnopqrstuvwxyz | sed -e 's/ /_/')
 	echo "sparc-fujitsu-${FUJITSU_SYS}${FUJITSU_REL}"
 	exit ;;
     i*86:BSD/386:*:* | i*86:BSD/OS:*:* | *:Ascend\ Embedded/OS:*:*)
@@ -839,25 +864,25 @@ EOF
 	echo "$UNAME_MACHINE"-unknown-bsdi"$UNAME_RELEASE"
 	exit ;;
     arm:FreeBSD:*:*)
-	UNAME_PROCESSOR=`uname -p`
+	UNAME_PROCESSOR=$(uname -p)
 	set_cc_for_build
 	if echo __ARM_PCS_VFP | $CC_FOR_BUILD -E - 2>/dev/null \
 	    | grep -q __ARM_PCS_VFP
 	then
-	    echo "${UNAME_PROCESSOR}"-unknown-freebsd"`echo ${UNAME_RELEASE}|sed -e 's/[-(].*//'`"-gnueabi
+	    echo "${UNAME_PROCESSOR}"-unknown-freebsd"$(echo ${UNAME_RELEASE}|sed -e 's/[-(].*//')"-gnueabi
 	else
-	    echo "${UNAME_PROCESSOR}"-unknown-freebsd"`echo ${UNAME_RELEASE}|sed -e 's/[-(].*//'`"-gnueabihf
+	    echo "${UNAME_PROCESSOR}"-unknown-freebsd"$(echo ${UNAME_RELEASE}|sed -e 's/[-(].*//')"-gnueabihf
 	fi
 	exit ;;
     *:FreeBSD:*:*)
-	UNAME_PROCESSOR=`/usr/bin/uname -p`
-	case "$UNAME_PROCESSOR" in
+	UNAME_PROCESSOR=$(/usr/bin/uname -p)
+	case $UNAME_PROCESSOR in
 	    amd64)
 		UNAME_PROCESSOR=x86_64 ;;
 	    i386)
 		UNAME_PROCESSOR=i586 ;;
 	esac
-	echo "$UNAME_PROCESSOR"-unknown-freebsd"`echo "$UNAME_RELEASE"|sed -e 's/[-(].*//'`"
+	echo "$UNAME_PROCESSOR"-unknown-freebsd"$(echo "$UNAME_RELEASE"|sed -e 's/[-(].*//')"
 	exit ;;
     i*:CYGWIN*:*)
 	echo "$UNAME_MACHINE"-pc-cygwin
@@ -875,7 +900,7 @@ EOF
 	echo "$UNAME_MACHINE"-pc-pw32
 	exit ;;
     *:Interix*:*)
-	case "$UNAME_MACHINE" in
+	case $UNAME_MACHINE in
 	    x86)
 		echo i586-pc-interix"$UNAME_RELEASE"
 		exit ;;
@@ -893,15 +918,15 @@ EOF
 	echo x86_64-pc-cygwin
 	exit ;;
     prep*:SunOS:5.*:*)
-	echo powerpcle-unknown-solaris2"`echo "$UNAME_RELEASE"|sed -e 's/[^.]*//'`"
+	echo powerpcle-unknown-solaris2"$(echo "$UNAME_RELEASE"|sed -e 's/[^.]*//')"
 	exit ;;
     *:GNU:*:*)
 	# the GNU system
-	echo "`echo "$UNAME_MACHINE"|sed -e 's,[-/].*$,,'`-unknown-$LIBC`echo "$UNAME_RELEASE"|sed -e 's,/.*$,,'`"
+	echo "$(echo "$UNAME_MACHINE"|sed -e 's,[-/].*$,,')-unknown-$LIBC$(echo "$UNAME_RELEASE"|sed -e 's,/.*$,,')"
 	exit ;;
     *:GNU/*:*:*)
 	# other systems with GNU libc and userland
-	echo "$UNAME_MACHINE-unknown-`echo "$UNAME_SYSTEM" | sed 's,^[^/]*/,,' | tr "[:upper:]" "[:lower:]"``echo "$UNAME_RELEASE"|sed -e 's/[-(].*//'`-$LIBC"
+	echo "$UNAME_MACHINE-unknown-$(echo "$UNAME_SYSTEM" | sed 's,^[^/]*/,,' | tr "[:upper:]" "[:lower:]")$(echo "$UNAME_RELEASE"|sed -e 's/[-(].*//')-$LIBC"
 	exit ;;
     *:Minix:*:*)
 	echo "$UNAME_MACHINE"-unknown-minix
@@ -914,7 +939,7 @@ EOF
 	echo "$UNAME_MACHINE"-unknown-linux-"$LIBC"
 	exit ;;
     alpha:Linux:*:*)
-	case `sed -n '/^cpu model/s/^.*: \(.*\)/\1/p' < /proc/cpuinfo` in
+	case $(sed -n '/^cpu model/s/^.*: \(.*\)/\1/p' /proc/cpuinfo 2>/dev/null) in
 	  EV5)   UNAME_MACHINE=alphaev5 ;;
 	  EV56)  UNAME_MACHINE=alphaev56 ;;
 	  PCA56) UNAME_MACHINE=alphapca56 ;;
@@ -927,7 +952,7 @@ EOF
 	if test "$?" = 0 ; then LIBC=gnulibc1 ; fi
 	echo "$UNAME_MACHINE"-unknown-linux-"$LIBC"
 	exit ;;
-    arc:Linux:*:* | arceb:Linux:*:*)
+    arc:Linux:*:* | arceb:Linux:*:* | arc64:Linux:*:*)
 	echo "$UNAME_MACHINE"-unknown-linux-"$LIBC"
 	exit ;;
     arm*:Linux:*:*)
@@ -973,6 +998,9 @@ EOF
     k1om:Linux:*:*)
 	echo "$UNAME_MACHINE"-unknown-linux-"$LIBC"
 	exit ;;
+    loongarch32:Linux:*:* | loongarch64:Linux:*:* | loongarchx32:Linux:*:*)
+	echo "$UNAME_MACHINE"-unknown-linux-"$LIBC"
+	exit ;;
     m32r*:Linux:*:*)
 	echo "$UNAME_MACHINE"-unknown-linux-"$LIBC"
 	exit ;;
@@ -981,22 +1009,50 @@ EOF
 	exit ;;
     mips:Linux:*:* | mips64:Linux:*:*)
 	set_cc_for_build
+	IS_GLIBC=0
+	test x"${LIBC}" = xgnu && IS_GLIBC=1
 	sed 's/^	//' << EOF > "$dummy.c"
 	#undef CPU
-	#undef ${UNAME_MACHINE}
-	#undef ${UNAME_MACHINE}el
+	#undef mips
+	#undef mipsel
+	#undef mips64
+	#undef mips64el
+	#if ${IS_GLIBC} && defined(_ABI64)
+	LIBCABI=gnuabi64
+	#else
+	#if ${IS_GLIBC} && defined(_ABIN32)
+	LIBCABI=gnuabin32
+	#else
+	LIBCABI=${LIBC}
+	#endif
+	#endif
+
+	#if ${IS_GLIBC} && defined(__mips64) && defined(__mips_isa_rev) && __mips_isa_rev>=6
+	CPU=mipsisa64r6
+	#else
+	#if ${IS_GLIBC} && !defined(__mips64) && defined(__mips_isa_rev) && __mips_isa_rev>=6
+	CPU=mipsisa32r6
+	#else
+	#if defined(__mips64)
+	CPU=mips64
+	#else
+	CPU=mips
+	#endif
+	#endif
+	#endif
+
 	#if defined(__MIPSEL__) || defined(__MIPSEL) || defined(_MIPSEL) || defined(MIPSEL)
-	CPU=${UNAME_MACHINE}el
+	MIPS_ENDIAN=el
 	#else
 	#if defined(__MIPSEB__) || defined(__MIPSEB) || defined(_MIPSEB) || defined(MIPSEB)
-	CPU=${UNAME_MACHINE}
+	MIPS_ENDIAN=
 	#else
-	CPU=
+	MIPS_ENDIAN=
 	#endif
 	#endif
 EOF
-	eval "`$CC_FOR_BUILD -E "$dummy.c" 2>/dev/null | grep '^CPU'`"
-	test "x$CPU" != x && { echo "$CPU-unknown-linux-$LIBC"; exit; }
+	eval "$($CC_FOR_BUILD -E "$dummy.c" 2>/dev/null | grep '^CPU\|^MIPS_ENDIAN\|^LIBCABI')"
+	test "x$CPU" != x && { echo "$CPU${MIPS_ENDIAN}-unknown-linux-$LIBCABI"; exit; }
 	;;
     mips64el:Linux:*:*)
 	echo "$UNAME_MACHINE"-unknown-linux-"$LIBC"
@@ -1015,7 +1071,7 @@ EOF
 	exit ;;
     parisc:Linux:*:* | hppa:Linux:*:*)
 	# Look for CPU level
-	case `grep '^cpu[^a-z]*:' /proc/cpuinfo 2>/dev/null | cut -d' ' -f2` in
+	case $(grep '^cpu[^a-z]*:' /proc/cpuinfo 2>/dev/null | cut -d' ' -f2) in
 	  PA7*) echo hppa1.1-unknown-linux-"$LIBC" ;;
 	  PA8*) echo hppa2.0-unknown-linux-"$LIBC" ;;
 	  *)    echo hppa-unknown-linux-"$LIBC" ;;
@@ -1033,7 +1089,7 @@ EOF
     ppcle:Linux:*:*)
 	echo powerpcle-unknown-linux-"$LIBC"
 	exit ;;
-    riscv32:Linux:*:* | riscv64:Linux:*:*)
+    riscv32:Linux:*:* | riscv32be:Linux:*:* | riscv64:Linux:*:* | riscv64be:Linux:*:*)
 	echo "$UNAME_MACHINE"-unknown-linux-"$LIBC"
 	exit ;;
     s390:Linux:*:* | s390x:Linux:*:*)
@@ -1055,7 +1111,17 @@ EOF
 	echo "$UNAME_MACHINE"-dec-linux-"$LIBC"
 	exit ;;
     x86_64:Linux:*:*)
-	echo "$UNAME_MACHINE"-pc-linux-"$LIBC"
+	set_cc_for_build
+	LIBCABI=$LIBC
+	if test "$CC_FOR_BUILD" != no_compiler_found; then
+	    if (echo '#ifdef __ILP32__'; echo IS_X32; echo '#endif') | \
+		(CCOPTS="" $CC_FOR_BUILD -E - 2>/dev/null) | \
+		grep IS_X32 >/dev/null
+	    then
+		LIBCABI="$LIBC"x32
+	    fi
+	fi
+	echo "$UNAME_MACHINE"-pc-linux-"$LIBCABI"
 	exit ;;
     xtensa*:Linux:*:*)
 	echo "$UNAME_MACHINE"-unknown-linux-"$LIBC"
@@ -1095,7 +1161,7 @@ EOF
 	echo "$UNAME_MACHINE"-pc-msdosdjgpp
 	exit ;;
     i*86:*:4.*:*)
-	UNAME_REL=`echo "$UNAME_RELEASE" | sed 's/\/MP$//'`
+	UNAME_REL=$(echo "$UNAME_RELEASE" | sed 's/\/MP$//')
 	if grep Novell /usr/include/link.h >/dev/null 2>/dev/null; then
 		echo "$UNAME_MACHINE"-univel-sysv"$UNAME_REL"
 	else
@@ -1104,19 +1170,19 @@ EOF
 	exit ;;
     i*86:*:5:[678]*)
 	# UnixWare 7.x, OpenUNIX and OpenServer 6.
-	case `/bin/uname -X | grep "^Machine"` in
+	case $(/bin/uname -X | grep "^Machine") in
 	    *486*)	     UNAME_MACHINE=i486 ;;
 	    *Pentium)	     UNAME_MACHINE=i586 ;;
 	    *Pent*|*Celeron) UNAME_MACHINE=i686 ;;
 	esac
-	echo "$UNAME_MACHINE-unknown-sysv${UNAME_RELEASE}${UNAME_SYSTEM}{$UNAME_VERSION}"
+	echo "$UNAME_MACHINE-unknown-sysv${UNAME_RELEASE}${UNAME_SYSTEM}${UNAME_VERSION}"
 	exit ;;
     i*86:*:3.2:*)
 	if test -f /usr/options/cb.name; then
-		UNAME_REL=`sed -n 's/.*Version //p' </usr/options/cb.name`
+		UNAME_REL=$(sed -n 's/.*Version //p' </usr/options/cb.name)
 		echo "$UNAME_MACHINE"-pc-isc"$UNAME_REL"
 	elif /bin/uname -X 2>/dev/null >/dev/null ; then
-		UNAME_REL=`(/bin/uname -X|grep Release|sed -e 's/.*= //')`
+		UNAME_REL=$( (/bin/uname -X|grep Release|sed -e 's/.*= //'))
 		(/bin/uname -X|grep i80486 >/dev/null) && UNAME_MACHINE=i486
 		(/bin/uname -X|grep '^Machine.*Pentium' >/dev/null) \
 			&& UNAME_MACHINE=i586
@@ -1166,7 +1232,7 @@ EOF
     3[345]??:*:4.0:3.0 | 3[34]??A:*:4.0:3.0 | 3[34]??,*:*:4.0:3.0 | 3[34]??/*:*:4.0:3.0 | 4400:*:4.0:3.0 | 4850:*:4.0:3.0 | SKA40:*:4.0:3.0 | SDS2:*:4.0:3.0 | SHG2:*:4.0:3.0 | S7501*:*:4.0:3.0)
 	OS_REL=''
 	test -r /etc/.relid \
-	&& OS_REL=.`sed -n 's/[^ ]* [^ ]* \([0-9][0-9]\).*/\1/p' < /etc/.relid`
+	&& OS_REL=.$(sed -n 's/[^ ]* [^ ]* \([0-9][0-9]\).*/\1/p' < /etc/.relid)
 	/bin/uname -p 2>/dev/null | grep 86 >/dev/null \
 	  && { echo i486-ncr-sysv4.3"$OS_REL"; exit; }
 	/bin/uname -p 2>/dev/null | /bin/grep entium >/dev/null \
@@ -1177,7 +1243,7 @@ EOF
     NCR*:*:4.2:* | MPRAS*:*:4.2:*)
 	OS_REL='.3'
 	test -r /etc/.relid \
-	    && OS_REL=.`sed -n 's/[^ ]* [^ ]* \([0-9][0-9]\).*/\1/p' < /etc/.relid`
+	    && OS_REL=.$(sed -n 's/[^ ]* [^ ]* \([0-9][0-9]\).*/\1/p' < /etc/.relid)
 	/bin/uname -p 2>/dev/null | grep 86 >/dev/null \
 	    && { echo i486-ncr-sysv4.3"$OS_REL"; exit; }
 	/bin/uname -p 2>/dev/null | /bin/grep entium >/dev/null \
@@ -1210,7 +1276,7 @@ EOF
 	exit ;;
     *:SINIX-*:*:*)
 	if uname -p 2>/dev/null >/dev/null ; then
-		UNAME_MACHINE=`(uname -p) 2>/dev/null`
+		UNAME_MACHINE=$( (uname -p) 2>/dev/null)
 		echo "$UNAME_MACHINE"-sni-sysv4
 	else
 		echo ns32k-sni-sysv
@@ -1244,7 +1310,7 @@ EOF
 	echo mips-sony-newsos6
 	exit ;;
     R[34]000:*System_V*:*:* | R4000:UNIX_SYSV:*:* | R*000:UNIX_SV:*:*)
-	if [ -d /usr/nec ]; then
+	if test -d /usr/nec; then
 		echo mips-nec-sysv"$UNAME_RELEASE"
 	else
 		echo mips-unknown-sysv"$UNAME_RELEASE"
@@ -1292,44 +1358,48 @@ EOF
     *:Rhapsody:*:*)
 	echo "$UNAME_MACHINE"-apple-rhapsody"$UNAME_RELEASE"
 	exit ;;
+    arm64:Darwin:*:*)
+	echo aarch64-apple-darwin"$UNAME_RELEASE"
+	exit ;;
     *:Darwin:*:*)
-	UNAME_PROCESSOR=`uname -p` || UNAME_PROCESSOR=unknown
-	set_cc_for_build
-	if test "$UNAME_PROCESSOR" = unknown ; then
-	    UNAME_PROCESSOR=powerpc
+	UNAME_PROCESSOR=$(uname -p)
+	case $UNAME_PROCESSOR in
+	    unknown) UNAME_PROCESSOR=powerpc ;;
+	esac
+	if command -v xcode-select > /dev/null 2> /dev/null && \
+		! xcode-select --print-path > /dev/null 2> /dev/null ; then
+	    # Avoid executing cc if there is no toolchain installed as
+	    # cc will be a stub that puts up a graphical alert
+	    # prompting the user to install developer tools.
+	    CC_FOR_BUILD=no_compiler_found
+	else
+	    set_cc_for_build
 	fi
-	if test "`echo "$UNAME_RELEASE" | sed -e 's/\..*//'`" -le 10 ; then
-	    if [ "$CC_FOR_BUILD" != no_compiler_found ]; then
-		if (echo '#ifdef __LP64__'; echo IS_64BIT_ARCH; echo '#endif') | \
-		       (CCOPTS="" $CC_FOR_BUILD -E - 2>/dev/null) | \
-		       grep IS_64BIT_ARCH >/dev/null
-		then
-		    case $UNAME_PROCESSOR in
-			i386) UNAME_PROCESSOR=x86_64 ;;
-			powerpc) UNAME_PROCESSOR=powerpc64 ;;
-		    esac
-		fi
-		# On 10.4-10.6 one might compile for PowerPC via gcc -arch ppc
-		if (echo '#ifdef __POWERPC__'; echo IS_PPC; echo '#endif') | \
-		       (CCOPTS="" $CC_FOR_BUILD -E - 2>/dev/null) | \
-		       grep IS_PPC >/dev/null
-		then
-		    UNAME_PROCESSOR=powerpc
-		fi
+	if test "$CC_FOR_BUILD" != no_compiler_found; then
+	    if (echo '#ifdef __LP64__'; echo IS_64BIT_ARCH; echo '#endif') | \
+		   (CCOPTS="" $CC_FOR_BUILD -E - 2>/dev/null) | \
+		   grep IS_64BIT_ARCH >/dev/null
+	    then
+		case $UNAME_PROCESSOR in
+		    i386) UNAME_PROCESSOR=x86_64 ;;
+		    powerpc) UNAME_PROCESSOR=powerpc64 ;;
+		esac
+	    fi
+	    # On 10.4-10.6 one might compile for PowerPC via gcc -arch ppc
+	    if (echo '#ifdef __POWERPC__'; echo IS_PPC; echo '#endif') | \
+		   (CCOPTS="" $CC_FOR_BUILD -E - 2>/dev/null) | \
+		   grep IS_PPC >/dev/null
+	    then
+		UNAME_PROCESSOR=powerpc
 	    fi
 	elif test "$UNAME_PROCESSOR" = i386 ; then
-	    # Avoid executing cc on OS X 10.9, as it ships with a stub
-	    # that puts up a graphical alert prompting to install
-	    # developer tools.  Any system running Mac OS X 10.7 or
-	    # later (Darwin 11 and later) is required to have a 64-bit
-	    # processor. This is not true of the ARM version of Darwin
-	    # that Apple uses in portable devices.
-	    UNAME_PROCESSOR=x86_64
+	    # uname -m returns i386 or x86_64
+	    UNAME_PROCESSOR=$UNAME_MACHINE
 	fi
 	echo "$UNAME_PROCESSOR"-apple-darwin"$UNAME_RELEASE"
 	exit ;;
     *:procnto*:*:* | *:QNX:[0123456789]*:*)
-	UNAME_PROCESSOR=`uname -p`
+	UNAME_PROCESSOR=$(uname -p)
 	if test "$UNAME_PROCESSOR" = x86; then
 		UNAME_PROCESSOR=i386
 		UNAME_MACHINE=pc
@@ -1367,10 +1437,9 @@ EOF
 	# "uname -m" is not consistent, so use $cputype instead. 386
 	# is converted to i386 for consistency with other x86
 	# operating systems.
-	# shellcheck disable=SC2154
-	if test "$cputype" = 386; then
+	if test "${cputype-}" = 386; then
 	    UNAME_MACHINE=i386
-	else
+	elif test "x${cputype-}" != x; then
 	    UNAME_MACHINE="$cputype"
 	fi
 	echo "$UNAME_MACHINE"-unknown-plan9
@@ -1397,11 +1466,11 @@ EOF
 	echo mips-sei-seiux"$UNAME_RELEASE"
 	exit ;;
     *:DragonFly:*:*)
-	echo "$UNAME_MACHINE"-unknown-dragonfly"`echo "$UNAME_RELEASE"|sed -e 's/[-(].*//'`"
+	echo "$UNAME_MACHINE"-unknown-dragonfly"$(echo "$UNAME_RELEASE"|sed -e 's/[-(].*//')"
 	exit ;;
     *:*VMS:*:*)
-	UNAME_MACHINE=`(uname -p) 2>/dev/null`
-	case "$UNAME_MACHINE" in
+	UNAME_MACHINE=$( (uname -p) 2>/dev/null)
+	case $UNAME_MACHINE in
 	    A*) echo alpha-dec-vms ; exit ;;
 	    I*) echo ia64-dec-vms ; exit ;;
 	    V*) echo vax-dec-vms ; exit ;;
@@ -1410,13 +1479,13 @@ EOF
 	echo i386-pc-xenix
 	exit ;;
     i*86:skyos:*:*)
-	echo "$UNAME_MACHINE"-pc-skyos"`echo "$UNAME_RELEASE" | sed -e 's/ .*$//'`"
+	echo "$UNAME_MACHINE"-pc-skyos"$(echo "$UNAME_RELEASE" | sed -e 's/ .*$//')"
 	exit ;;
     i*86:rdos:*:*)
 	echo "$UNAME_MACHINE"-pc-rdos
 	exit ;;
-    i*86:AROS:*:*)
-	echo "$UNAME_MACHINE"-pc-aros
+    *:AROS:*:*)
+	echo "$UNAME_MACHINE"-unknown-aros
 	exit ;;
     x86_64:VMkernel:*:*)
 	echo "$UNAME_MACHINE"-unknown-esx
@@ -1424,11 +1493,151 @@ EOF
     amd64:Isilon\ OneFS:*:*)
 	echo x86_64-unknown-onefs
 	exit ;;
+    *:Unleashed:*:*)
+	echo "$UNAME_MACHINE"-unknown-unleashed"$UNAME_RELEASE"
+	exit ;;
 esac
 
+# No uname command or uname output not recognized.
+set_cc_for_build
+cat > "$dummy.c" <<EOF
+#ifdef _SEQUENT_
+#include <sys/types.h>
+#include <sys/utsname.h>
+#endif
+#if defined(ultrix) || defined(_ultrix) || defined(__ultrix) || defined(__ultrix__)
+#if defined (vax) || defined (__vax) || defined (__vax__) || defined(mips) || defined(__mips) || defined(__mips__) || defined(MIPS) || defined(__MIPS__)
+#include <signal.h>
+#if defined(_SIZE_T_) || defined(SIGLOST)
+#include <sys/utsname.h>
+#endif
+#endif
+#endif
+main ()
+{
+#if defined (sony)
+#if defined (MIPSEB)
+  /* BFD wants "bsd" instead of "newsos".  Perhaps BFD should be changed,
+     I don't know....  */
+  printf ("mips-sony-bsd\n"); exit (0);
+#else
+#include <sys/param.h>
+  printf ("m68k-sony-newsos%s\n",
+#ifdef NEWSOS4
+  "4"
+#else
+  ""
+#endif
+  ); exit (0);
+#endif
+#endif
+
+#if defined (NeXT)
+#if !defined (__ARCHITECTURE__)
+#define __ARCHITECTURE__ "m68k"
+#endif
+  int version;
+  version=$( (hostinfo | sed -n 's/.*NeXT Mach \([0-9]*\).*/\1/p') 2>/dev/null);
+  if (version < 4)
+    printf ("%s-next-nextstep%d\n", __ARCHITECTURE__, version);
+  else
+    printf ("%s-next-openstep%d\n", __ARCHITECTURE__, version);
+  exit (0);
+#endif
+
+#if defined (MULTIMAX) || defined (n16)
+#if defined (UMAXV)
+  printf ("ns32k-encore-sysv\n"); exit (0);
+#else
+#if defined (CMU)
+  printf ("ns32k-encore-mach\n"); exit (0);
+#else
+  printf ("ns32k-encore-bsd\n"); exit (0);
+#endif
+#endif
+#endif
+
+#if defined (__386BSD__)
+  printf ("i386-pc-bsd\n"); exit (0);
+#endif
+
+#if defined (sequent)
+#if defined (i386)
+  printf ("i386-sequent-dynix\n"); exit (0);
+#endif
+#if defined (ns32000)
+  printf ("ns32k-sequent-dynix\n"); exit (0);
+#endif
+#endif
+
+#if defined (_SEQUENT_)
+  struct utsname un;
+
+  uname(&un);
+  if (strncmp(un.version, "V2", 2) == 0) {
+    printf ("i386-sequent-ptx2\n"); exit (0);
+  }
+  if (strncmp(un.version, "V1", 2) == 0) { /* XXX is V1 correct? */
+    printf ("i386-sequent-ptx1\n"); exit (0);
+  }
+  printf ("i386-sequent-ptx\n"); exit (0);
+#endif
+
+#if defined (vax)
+#if !defined (ultrix)
+#include <sys/param.h>
+#if defined (BSD)
+#if BSD == 43
+  printf ("vax-dec-bsd4.3\n"); exit (0);
+#else
+#if BSD == 199006
+  printf ("vax-dec-bsd4.3reno\n"); exit (0);
+#else
+  printf ("vax-dec-bsd\n"); exit (0);
+#endif
+#endif
+#else
+  printf ("vax-dec-bsd\n"); exit (0);
+#endif
+#else
+#if defined(_SIZE_T_) || defined(SIGLOST)
+  struct utsname un;
+  uname (&un);
+  printf ("vax-dec-ultrix%s\n", un.release); exit (0);
+#else
+  printf ("vax-dec-ultrix\n"); exit (0);
+#endif
+#endif
+#endif
+#if defined(ultrix) || defined(_ultrix) || defined(__ultrix) || defined(__ultrix__)
+#if defined(mips) || defined(__mips) || defined(__mips__) || defined(MIPS) || defined(__MIPS__)
+#if defined(_SIZE_T_) || defined(SIGLOST)
+  struct utsname *un;
+  uname (&un);
+  printf ("mips-dec-ultrix%s\n", un.release); exit (0);
+#else
+  printf ("mips-dec-ultrix\n"); exit (0);
+#endif
+#endif
+#endif
+
+#if defined (alliant) && defined (i860)
+  printf ("i860-alliant-bsd\n"); exit (0);
+#endif
+
+  exit (1);
+}
+EOF
+
+$CC_FOR_BUILD -o "$dummy" "$dummy.c" 2>/dev/null && SYSTEM_NAME=$($dummy) &&
+	{ echo "$SYSTEM_NAME"; exit; }
+
+# Apollos put the system type in the environment.
+test -d /usr/apollo && { echo "$ISP-apollo-$SYSTYPE"; exit; }
+
 echo "$0: unable to guess system type" >&2
 
-case "$UNAME_MACHINE:$UNAME_SYSTEM" in
+case $UNAME_MACHINE:$UNAME_SYSTEM in
     mips:Linux | mips64:Linux)
 	# If we got here on MIPS GNU/Linux, output extra information.
 	cat >&2 <<EOF
@@ -1445,9 +1654,15 @@ This script (version $timestamp), has failed to recognize the
 operating system you are using. If your script is old, overwrite *all*
 copies of config.guess and config.sub with the latest versions from:
 
-  https://git.savannah.gnu.org/gitweb/?p=config.git;a=blob_plain;f=config.guess
+  https://git.savannah.gnu.org/cgit/config.git/plain/config.guess
 and
-  https://git.savannah.gnu.org/gitweb/?p=config.git;a=blob_plain;f=config.sub
+  https://git.savannah.gnu.org/cgit/config.git/plain/config.sub
+EOF
+
+year=$(echo $timestamp | sed 's,-.*,,')
+# shellcheck disable=SC2003
+if test "$(expr "$(date +%Y)" - "$year")" -lt 3 ; then
+   cat >&2 <<EOF
 
 If $0 has already been updated, send the following data and any
 information you think might be pertinent to config-patches@gnu.org to
@@ -1455,26 +1670,27 @@ provide the necessary information to handle your system.
 
 config.guess timestamp = $timestamp
 
-uname -m = `(uname -m) 2>/dev/null || echo unknown`
-uname -r = `(uname -r) 2>/dev/null || echo unknown`
-uname -s = `(uname -s) 2>/dev/null || echo unknown`
-uname -v = `(uname -v) 2>/dev/null || echo unknown`
+uname -m = $( (uname -m) 2>/dev/null || echo unknown)
+uname -r = $( (uname -r) 2>/dev/null || echo unknown)
+uname -s = $( (uname -s) 2>/dev/null || echo unknown)
+uname -v = $( (uname -v) 2>/dev/null || echo unknown)
 
-/usr/bin/uname -p = `(/usr/bin/uname -p) 2>/dev/null`
-/bin/uname -X     = `(/bin/uname -X) 2>/dev/null`
+/usr/bin/uname -p = $( (/usr/bin/uname -p) 2>/dev/null)
+/bin/uname -X     = $( (/bin/uname -X) 2>/dev/null)
 
-hostinfo               = `(hostinfo) 2>/dev/null`
-/bin/universe          = `(/bin/universe) 2>/dev/null`
-/usr/bin/arch -k       = `(/usr/bin/arch -k) 2>/dev/null`
-/bin/arch              = `(/bin/arch) 2>/dev/null`
-/usr/bin/oslevel       = `(/usr/bin/oslevel) 2>/dev/null`
-/usr/convex/getsysinfo = `(/usr/convex/getsysinfo) 2>/dev/null`
+hostinfo               = $( (hostinfo) 2>/dev/null)
+/bin/universe          = $( (/bin/universe) 2>/dev/null)
+/usr/bin/arch -k       = $( (/usr/bin/arch -k) 2>/dev/null)
+/bin/arch              = $( (/bin/arch) 2>/dev/null)
+/usr/bin/oslevel       = $( (/usr/bin/oslevel) 2>/dev/null)
+/usr/convex/getsysinfo = $( (/usr/convex/getsysinfo) 2>/dev/null)
 
 UNAME_MACHINE = "$UNAME_MACHINE"
 UNAME_RELEASE = "$UNAME_RELEASE"
 UNAME_SYSTEM  = "$UNAME_SYSTEM"
 UNAME_VERSION = "$UNAME_VERSION"
 EOF
+fi
 
 exit 1
 
diff --git a/scripts/config.sub b/scripts/config.sub
index f208558ec2..7384e9198b 100755
--- a/scripts/config.sub
+++ b/scripts/config.sub
@@ -1,8 +1,8 @@
 #! /bin/sh
 # Configuration validation subroutine script.
-#   Copyright 1992-2018 Free Software Foundation, Inc.
+#   Copyright 1992-2021 Free Software Foundation, Inc.
 
-timestamp='2018-08-29'
+timestamp='2021-04-30'
 
 # This file is free software; you can redistribute it and/or modify it
 # under the terms of the GNU General Public License as published by
@@ -33,7 +33,7 @@ timestamp='2018-08-29'
 # Otherwise, we print the canonical config type on stdout and succeed.
 
 # You can get the latest version of this script from:
-# https://git.savannah.gnu.org/gitweb/?p=config.git;a=blob_plain;f=config.sub
+# https://git.savannah.gnu.org/cgit/config.git/plain/config.sub
 
 # This file is supposed to be the same for all GNU packages
 # and recognize all the CPU types, system types and aliases
@@ -50,7 +50,7 @@ timestamp='2018-08-29'
 #	CPU_TYPE-MANUFACTURER-KERNEL-OPERATING_SYSTEM
 # It is wrong to echo any other type of specification.
 
-me=`echo "$0" | sed -e 's,.*/,,'`
+me=$(echo "$0" | sed -e 's,.*/,,')
 
 usage="\
 Usage: $0 [OPTION] CPU-MFR-OPSYS or ALIAS
@@ -67,7 +67,7 @@ Report bugs and patches to <config-patches@gnu.org>."
 version="\
 GNU config.sub ($timestamp)
 
-Copyright 1992-2018 Free Software Foundation, Inc.
+Copyright 1992-2021 Free Software Foundation, Inc.
 
 This is free software; see the source for copying conditions.  There is NO
 warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE."
@@ -111,7 +111,8 @@ case $# in
 esac
 
 # Split fields of configuration type
-IFS="-" read -r field1 field2 field3 field4 <<EOF
+# shellcheck disable=SC2162
+IFS="-" read field1 field2 field3 field4 <<EOF
 $1
 EOF
 
@@ -123,28 +124,27 @@ case $1 in
 		;;
 	*-*-*-*)
 		basic_machine=$field1-$field2
-		os=$field3-$field4
+		basic_os=$field3-$field4
 		;;
 	*-*-*)
 		# Ambiguous whether COMPANY is present, or skipped and KERNEL-OS is two
 		# parts
 		maybe_os=$field2-$field3
 		case $maybe_os in
-			nto-qnx* | linux-gnu* | linux-android* | linux-dietlibc \
-			| linux-newlib* | linux-musl* | linux-uclibc* | uclinux-uclibc* \
+			nto-qnx* | linux-* | uclinux-uclibc* \
 			| uclinux-gnu* | kfreebsd*-gnu* | knetbsd*-gnu* | netbsd*-gnu* \
 			| netbsd*-eabi* | kopensolaris*-gnu* | cloudabi*-eabi* \
 			| storm-chaos* | os2-emx* | rtmk-nova*)
 				basic_machine=$field1
-				os=$maybe_os
+				basic_os=$maybe_os
 				;;
 			android-linux)
 				basic_machine=$field1-unknown
-				os=linux-android
+				basic_os=linux-android
 				;;
 			*)
 				basic_machine=$field1-$field2
-				os=$field3
+				basic_os=$field3
 				;;
 		esac
 		;;
@@ -153,7 +153,7 @@ case $1 in
 		case $field1-$field2 in
 			decstation-3100)
 				basic_machine=mips-dec
-				os=
+				basic_os=
 				;;
 			*-*)
 				# Second component is usually, but not always the OS
@@ -161,7 +161,7 @@ case $1 in
 					# Prevent following clause from handling this valid os
 					sun*os*)
 						basic_machine=$field1
-						os=$field2
+						basic_os=$field2
 						;;
 					# Manufacturers
 					dec* | mips* | sequent* | encore* | pc533* | sgi* | sony* \
@@ -174,11 +174,11 @@ case $1 in
 					| microblaze* | sim | cisco \
 					| oki | wec | wrs | winbond)
 						basic_machine=$field1-$field2
-						os=
+						basic_os=
 						;;
 					*)
 						basic_machine=$field1
-						os=$field2
+						basic_os=$field2
 						;;
 				esac
 			;;
@@ -190,450 +190,451 @@ case $1 in
 		case $field1 in
 			386bsd)
 				basic_machine=i386-pc
-				os=bsd
+				basic_os=bsd
 				;;
 			a29khif)
 				basic_machine=a29k-amd
-				os=udi
+				basic_os=udi
 				;;
 			adobe68k)
 				basic_machine=m68010-adobe
-				os=scout
+				basic_os=scout
 				;;
 			alliant)
 				basic_machine=fx80-alliant
-				os=
+				basic_os=
 				;;
 			altos | altos3068)
 				basic_machine=m68k-altos
-				os=
+				basic_os=
 				;;
 			am29k)
 				basic_machine=a29k-none
-				os=bsd
+				basic_os=bsd
 				;;
 			amdahl)
 				basic_machine=580-amdahl
-				os=sysv
+				basic_os=sysv
 				;;
 			amiga)
 				basic_machine=m68k-unknown
-				os=
+				basic_os=
 				;;
 			amigaos | amigados)
 				basic_machine=m68k-unknown
-				os=amigaos
+				basic_os=amigaos
 				;;
 			amigaunix | amix)
 				basic_machine=m68k-unknown
-				os=sysv4
+				basic_os=sysv4
 				;;
 			apollo68)
 				basic_machine=m68k-apollo
-				os=sysv
+				basic_os=sysv
 				;;
 			apollo68bsd)
 				basic_machine=m68k-apollo
-				os=bsd
+				basic_os=bsd
 				;;
 			aros)
 				basic_machine=i386-pc
-				os=aros
+				basic_os=aros
 				;;
 			aux)
 				basic_machine=m68k-apple
-				os=aux
+				basic_os=aux
 				;;
 			balance)
 				basic_machine=ns32k-sequent
-				os=dynix
+				basic_os=dynix
 				;;
 			blackfin)
 				basic_machine=bfin-unknown
-				os=linux
+				basic_os=linux
 				;;
 			cegcc)
 				basic_machine=arm-unknown
-				os=cegcc
+				basic_os=cegcc
 				;;
 			convex-c1)
 				basic_machine=c1-convex
-				os=bsd
+				basic_os=bsd
 				;;
 			convex-c2)
 				basic_machine=c2-convex
-				os=bsd
+				basic_os=bsd
 				;;
 			convex-c32)
 				basic_machine=c32-convex
-				os=bsd
+				basic_os=bsd
 				;;
 			convex-c34)
 				basic_machine=c34-convex
-				os=bsd
+				basic_os=bsd
 				;;
 			convex-c38)
 				basic_machine=c38-convex
-				os=bsd
+				basic_os=bsd
 				;;
 			cray)
 				basic_machine=j90-cray
-				os=unicos
+				basic_os=unicos
 				;;
 			crds | unos)
 				basic_machine=m68k-crds
-				os=
+				basic_os=
 				;;
 			da30)
 				basic_machine=m68k-da30
-				os=
+				basic_os=
 				;;
 			decstation | pmax | pmin | dec3100 | decstatn)
 				basic_machine=mips-dec
-				os=
+				basic_os=
 				;;
 			delta88)
 				basic_machine=m88k-motorola
-				os=sysv3
+				basic_os=sysv3
 				;;
 			dicos)
 				basic_machine=i686-pc
-				os=dicos
+				basic_os=dicos
 				;;
 			djgpp)
 				basic_machine=i586-pc
-				os=msdosdjgpp
+				basic_os=msdosdjgpp
 				;;
 			ebmon29k)
 				basic_machine=a29k-amd
-				os=ebmon
+				basic_os=ebmon
 				;;
 			es1800 | OSE68k | ose68k | ose | OSE)
 				basic_machine=m68k-ericsson
-				os=ose
+				basic_os=ose
 				;;
 			gmicro)
 				basic_machine=tron-gmicro
-				os=sysv
+				basic_os=sysv
 				;;
 			go32)
 				basic_machine=i386-pc
-				os=go32
+				basic_os=go32
 				;;
 			h8300hms)
 				basic_machine=h8300-hitachi
-				os=hms
+				basic_os=hms
 				;;
 			h8300xray)
 				basic_machine=h8300-hitachi
-				os=xray
+				basic_os=xray
 				;;
 			h8500hms)
 				basic_machine=h8500-hitachi
-				os=hms
+				basic_os=hms
 				;;
 			harris)
 				basic_machine=m88k-harris
-				os=sysv3
+				basic_os=sysv3
 				;;
-			hp300)
+			hp300 | hp300hpux)
 				basic_machine=m68k-hp
+				basic_os=hpux
 				;;
 			hp300bsd)
 				basic_machine=m68k-hp
-				os=bsd
-				;;
-			hp300hpux)
-				basic_machine=m68k-hp
-				os=hpux
+				basic_os=bsd
 				;;
 			hppaosf)
 				basic_machine=hppa1.1-hp
-				os=osf
+				basic_os=osf
 				;;
 			hppro)
 				basic_machine=hppa1.1-hp
-				os=proelf
+				basic_os=proelf
 				;;
 			i386mach)
 				basic_machine=i386-mach
-				os=mach
-				;;
-			vsta)
-				basic_machine=i386-pc
-				os=vsta
+				basic_os=mach
 				;;
 			isi68 | isi)
 				basic_machine=m68k-isi
-				os=sysv
+				basic_os=sysv
 				;;
 			m68knommu)
 				basic_machine=m68k-unknown
-				os=linux
+				basic_os=linux
 				;;
 			magnum | m3230)
 				basic_machine=mips-mips
-				os=sysv
+				basic_os=sysv
 				;;
 			merlin)
 				basic_machine=ns32k-utek
-				os=sysv
+				basic_os=sysv
 				;;
 			mingw64)
 				basic_machine=x86_64-pc
-				os=mingw64
+				basic_os=mingw64
 				;;
 			mingw32)
 				basic_machine=i686-pc
-				os=mingw32
+				basic_os=mingw32
 				;;
 			mingw32ce)
 				basic_machine=arm-unknown
-				os=mingw32ce
+				basic_os=mingw32ce
 				;;
 			monitor)
 				basic_machine=m68k-rom68k
-				os=coff
+				basic_os=coff
 				;;
 			morphos)
 				basic_machine=powerpc-unknown
-				os=morphos
+				basic_os=morphos
 				;;
 			moxiebox)
 				basic_machine=moxie-unknown
-				os=moxiebox
+				basic_os=moxiebox
 				;;
 			msdos)
 				basic_machine=i386-pc
-				os=msdos
+				basic_os=msdos
 				;;
 			msys)
 				basic_machine=i686-pc
-				os=msys
+				basic_os=msys
 				;;
 			mvs)
 				basic_machine=i370-ibm
-				os=mvs
+				basic_os=mvs
 				;;
 			nacl)
 				basic_machine=le32-unknown
-				os=nacl
+				basic_os=nacl
 				;;
 			ncr3000)
 				basic_machine=i486-ncr
-				os=sysv4
+				basic_os=sysv4
 				;;
 			netbsd386)
 				basic_machine=i386-pc
-				os=netbsd
+				basic_os=netbsd
 				;;
 			netwinder)
 				basic_machine=armv4l-rebel
-				os=linux
+				basic_os=linux
 				;;
 			news | news700 | news800 | news900)
 				basic_machine=m68k-sony
-				os=newsos
+				basic_os=newsos
 				;;
 			news1000)
 				basic_machine=m68030-sony
-				os=newsos
+				basic_os=newsos
 				;;
 			necv70)
 				basic_machine=v70-nec
-				os=sysv
+				basic_os=sysv
 				;;
 			nh3000)
 				basic_machine=m68k-harris
-				os=cxux
+				basic_os=cxux
 				;;
 			nh[45]000)
 				basic_machine=m88k-harris
-				os=cxux
+				basic_os=cxux
 				;;
 			nindy960)
 				basic_machine=i960-intel
-				os=nindy
+				basic_os=nindy
 				;;
 			mon960)
 				basic_machine=i960-intel
-				os=mon960
+				basic_os=mon960
 				;;
 			nonstopux)
 				basic_machine=mips-compaq
-				os=nonstopux
+				basic_os=nonstopux
 				;;
 			os400)
 				basic_machine=powerpc-ibm
-				os=os400
+				basic_os=os400
 				;;
 			OSE68000 | ose68000)
 				basic_machine=m68000-ericsson
-				os=ose
+				basic_os=ose
 				;;
 			os68k)
 				basic_machine=m68k-none
-				os=os68k
+				basic_os=os68k
 				;;
 			paragon)
 				basic_machine=i860-intel
-				os=osf
+				basic_os=osf
 				;;
 			parisc)
 				basic_machine=hppa-unknown
-				os=linux
+				basic_os=linux
+				;;
+			psp)
+				basic_machine=mipsallegrexel-sony
+				basic_os=psp
 				;;
 			pw32)
 				basic_machine=i586-unknown
-				os=pw32
+				basic_os=pw32
 				;;
 			rdos | rdos64)
 				basic_machine=x86_64-pc
-				os=rdos
+				basic_os=rdos
 				;;
 			rdos32)
 				basic_machine=i386-pc
-				os=rdos
+				basic_os=rdos
 				;;
 			rom68k)
 				basic_machine=m68k-rom68k
-				os=coff
+				basic_os=coff
 				;;
 			sa29200)
 				basic_machine=a29k-amd
-				os=udi
+				basic_os=udi
 				;;
 			sei)
 				basic_machine=mips-sei
-				os=seiux
+				basic_os=seiux
 				;;
 			sequent)
 				basic_machine=i386-sequent
-				os=
+				basic_os=
 				;;
 			sps7)
 				basic_machine=m68k-bull
-				os=sysv2
+				basic_os=sysv2
 				;;
 			st2000)
 				basic_machine=m68k-tandem
-				os=
+				basic_os=
 				;;
 			stratus)
 				basic_machine=i860-stratus
-				os=sysv4
+				basic_os=sysv4
 				;;
 			sun2)
 				basic_machine=m68000-sun
-				os=
+				basic_os=
 				;;
 			sun2os3)
 				basic_machine=m68000-sun
-				os=sunos3
+				basic_os=sunos3
 				;;
 			sun2os4)
 				basic_machine=m68000-sun
-				os=sunos4
+				basic_os=sunos4
 				;;
 			sun3)
 				basic_machine=m68k-sun
-				os=
+				basic_os=
 				;;
 			sun3os3)
 				basic_machine=m68k-sun
-				os=sunos3
+				basic_os=sunos3
 				;;
 			sun3os4)
 				basic_machine=m68k-sun
-				os=sunos4
+				basic_os=sunos4
 				;;
 			sun4)
 				basic_machine=sparc-sun
-				os=
+				basic_os=
 				;;
 			sun4os3)
 				basic_machine=sparc-sun
-				os=sunos3
+				basic_os=sunos3
 				;;
 			sun4os4)
 				basic_machine=sparc-sun
-				os=sunos4
+				basic_os=sunos4
 				;;
 			sun4sol2)
 				basic_machine=sparc-sun
-				os=solaris2
+				basic_os=solaris2
 				;;
 			sun386 | sun386i | roadrunner)
 				basic_machine=i386-sun
-				os=
+				basic_os=
 				;;
 			sv1)
 				basic_machine=sv1-cray
-				os=unicos
+				basic_os=unicos
 				;;
 			symmetry)
 				basic_machine=i386-sequent
-				os=dynix
+				basic_os=dynix
 				;;
 			t3e)
 				basic_machine=alphaev5-cray
-				os=unicos
+				basic_os=unicos
 				;;
 			t90)
 				basic_machine=t90-cray
-				os=unicos
+				basic_os=unicos
 				;;
 			toad1)
 				basic_machine=pdp10-xkl
-				os=tops20
+				basic_os=tops20
 				;;
 			tpf)
 				basic_machine=s390x-ibm
-				os=tpf
+				basic_os=tpf
 				;;
 			udi29k)
 				basic_machine=a29k-amd
-				os=udi
+				basic_os=udi
 				;;
 			ultra3)
 				basic_machine=a29k-nyu
-				os=sym1
+				basic_os=sym1
 				;;
 			v810 | necv810)
 				basic_machine=v810-nec
-				os=none
+				basic_os=none
 				;;
 			vaxv)
 				basic_machine=vax-dec
-				os=sysv
+				basic_os=sysv
 				;;
 			vms)
 				basic_machine=vax-dec
-				os=vms
+				basic_os=vms
+				;;
+			vsta)
+				basic_machine=i386-pc
+				basic_os=vsta
 				;;
 			vxworks960)
 				basic_machine=i960-wrs
-				os=vxworks
+				basic_os=vxworks
 				;;
 			vxworks68)
 				basic_machine=m68k-wrs
-				os=vxworks
+				basic_os=vxworks
 				;;
 			vxworks29k)
 				basic_machine=a29k-wrs
-				os=vxworks
+				basic_os=vxworks
 				;;
 			xbox)
 				basic_machine=i686-pc
-				os=mingw32
+				basic_os=mingw32
 				;;
 			ymp)
 				basic_machine=ymp-cray
-				os=unicos
+				basic_os=unicos
 				;;
 			*)
 				basic_machine=$1
-				os=
+				basic_os=
 				;;
 		esac
 		;;
@@ -685,17 +686,17 @@ case $basic_machine in
 	bluegene*)
 		cpu=powerpc
 		vendor=ibm
-		os=cnk
+		basic_os=cnk
 		;;
 	decsystem10* | dec10*)
 		cpu=pdp10
 		vendor=dec
-		os=tops10
+		basic_os=tops10
 		;;
 	decsystem20* | dec20*)
 		cpu=pdp10
 		vendor=dec
-		os=tops20
+		basic_os=tops20
 		;;
 	delta | 3300 | motorola-3300 | motorola-delta \
 	      | 3300-motorola | delta-motorola)
@@ -705,7 +706,7 @@ case $basic_machine in
 	dpx2*)
 		cpu=m68k
 		vendor=bull
-		os=sysv3
+		basic_os=sysv3
 		;;
 	encore | umax | mmax)
 		cpu=ns32k
@@ -714,7 +715,7 @@ case $basic_machine in
 	elxsi)
 		cpu=elxsi
 		vendor=elxsi
-		os=${os:-bsd}
+		basic_os=${basic_os:-bsd}
 		;;
 	fx2800)
 		cpu=i860
@@ -727,7 +728,7 @@ case $basic_machine in
 	h3050r* | hiux*)
 		cpu=hppa1.1
 		vendor=hitachi
-		os=hiuxwe2
+		basic_os=hiuxwe2
 		;;
 	hp3k9[0-9][0-9] | hp9[0-9][0-9])
 		cpu=hppa1.0
@@ -768,38 +769,38 @@ case $basic_machine in
 		vendor=hp
 		;;
 	i*86v32)
-		cpu=`echo "$1" | sed -e 's/86.*/86/'`
+		cpu=$(echo "$1" | sed -e 's/86.*/86/')
 		vendor=pc
-		os=sysv32
+		basic_os=sysv32
 		;;
 	i*86v4*)
-		cpu=`echo "$1" | sed -e 's/86.*/86/'`
+		cpu=$(echo "$1" | sed -e 's/86.*/86/')
 		vendor=pc
-		os=sysv4
+		basic_os=sysv4
 		;;
 	i*86v)
-		cpu=`echo "$1" | sed -e 's/86.*/86/'`
+		cpu=$(echo "$1" | sed -e 's/86.*/86/')
 		vendor=pc
-		os=sysv
+		basic_os=sysv
 		;;
 	i*86sol2)
-		cpu=`echo "$1" | sed -e 's/86.*/86/'`
+		cpu=$(echo "$1" | sed -e 's/86.*/86/')
 		vendor=pc
-		os=solaris2
+		basic_os=solaris2
 		;;
 	j90 | j90-cray)
 		cpu=j90
 		vendor=cray
-		os=${os:-unicos}
+		basic_os=${basic_os:-unicos}
 		;;
 	iris | iris4d)
 		cpu=mips
 		vendor=sgi
-		case $os in
+		case $basic_os in
 		    irix*)
 			;;
 		    *)
-			os=irix4
+			basic_os=irix4
 			;;
 		esac
 		;;
@@ -810,24 +811,26 @@ case $basic_machine in
 	*mint | mint[0-9]* | *MiNT | *MiNT[0-9]*)
 		cpu=m68k
 		vendor=atari
-		os=mint
+		basic_os=mint
 		;;
 	news-3600 | risc-news)
 		cpu=mips
 		vendor=sony
-		os=newsos
+		basic_os=newsos
 		;;
 	next | m*-next)
 		cpu=m68k
 		vendor=next
-		case $os in
-		    nextstep* )
+		case $basic_os in
+		    openstep*)
+		        ;;
+		    nextstep*)
 			;;
 		    ns2*)
-		      os=nextstep2
+		      basic_os=nextstep2
 			;;
 		    *)
-		      os=nextstep3
+		      basic_os=nextstep3
 			;;
 		esac
 		;;
@@ -838,12 +841,12 @@ case $basic_machine in
 	op50n-* | op60c-*)
 		cpu=hppa1.1
 		vendor=oki
-		os=proelf
+		basic_os=proelf
 		;;
 	pa-hitachi)
 		cpu=hppa1.1
 		vendor=hitachi
-		os=hiuxwe2
+		basic_os=hiuxwe2
 		;;
 	pbd)
 		cpu=sparc
@@ -880,12 +883,12 @@ case $basic_machine in
 	sde)
 		cpu=mipsisa32
 		vendor=sde
-		os=${os:-elf}
+		basic_os=${basic_os:-elf}
 		;;
 	simso-wrs)
 		cpu=sparclite
 		vendor=wrs
-		os=vxworks
+		basic_os=vxworks
 		;;
 	tower | tower-32)
 		cpu=m68k
@@ -902,7 +905,7 @@ case $basic_machine in
 	w89k-*)
 		cpu=hppa1.1
 		vendor=winbond
-		os=proelf
+		basic_os=proelf
 		;;
 	none)
 		cpu=none
@@ -914,11 +917,12 @@ case $basic_machine in
 		;;
 	leon-*|leon[3-9]-*)
 		cpu=sparc
-		vendor=`echo "$basic_machine" | sed 's/-.*//'`
+		vendor=$(echo "$basic_machine" | sed 's/-.*//')
 		;;
 
 	*-*)
-		IFS="-" read -r cpu vendor <<EOF
+		# shellcheck disable=SC2162
+		IFS="-" read cpu vendor <<EOF
 $basic_machine
 EOF
 		;;
@@ -954,11 +958,11 @@ case $cpu-$vendor in
 	# some cases the only manufacturer, in others, it is the most popular.
 	craynv-unknown)
 		vendor=cray
-		os=${os:-unicosmp}
+		basic_os=${basic_os:-unicosmp}
 		;;
 	c90-unknown | c90-cray)
 		vendor=cray
-		os=${os:-unicos}
+		basic_os=${Basic_os:-unicos}
 		;;
 	fx80-unknown)
 		vendor=alliant
@@ -1002,7 +1006,7 @@ case $cpu-$vendor in
 	dpx20-unknown | dpx20-bull)
 		cpu=rs6000
 		vendor=bull
-		os=${os:-bosx}
+		basic_os=${basic_os:-bosx}
 		;;
 
 	# Here we normalize CPU types irrespective of the vendor
@@ -1011,7 +1015,7 @@ case $cpu-$vendor in
 		;;
 	blackfin-*)
 		cpu=bfin
-		os=linux
+		basic_os=linux
 		;;
 	c54x-*)
 		cpu=tic54x
@@ -1024,7 +1028,7 @@ case $cpu-$vendor in
 		;;
 	e500v[12]-*)
 		cpu=powerpc
-		os=$os"spe"
+		basic_os=${basic_os}"spe"
 		;;
 	mips3*-*)
 		cpu=mips64
@@ -1034,7 +1038,7 @@ case $cpu-$vendor in
 		;;
 	m68knommu-*)
 		cpu=m68k
-		os=linux
+		basic_os=linux
 		;;
 	m9s12z-* | m68hcs12z-* | hcs12z-* | s12z-*)
 		cpu=s12z
@@ -1044,7 +1048,7 @@ case $cpu-$vendor in
 		;;
 	parisc-*)
 		cpu=hppa
-		os=linux
+		basic_os=linux
 		;;
 	pentium-* | p5-* | k5-* | k6-* | nexgen-* | viac3-*)
 		cpu=i586
@@ -1080,7 +1084,7 @@ case $cpu-$vendor in
 		cpu=mipsisa64sb1el
 		;;
 	sh5e[lb]-*)
-		cpu=`echo "$cpu" | sed 's/^\(sh.\)e\(.\)$/\1\2e/'`
+		cpu=$(echo "$cpu" | sed 's/^\(sh.\)e\(.\)$/\1\2e/')
 		;;
 	spur-*)
 		cpu=spur
@@ -1098,13 +1102,16 @@ case $cpu-$vendor in
 		cpu=x86_64
 		;;
 	xscale-* | xscalee[bl]-*)
-		cpu=`echo "$cpu" | sed 's/^xscale/arm/'`
+		cpu=$(echo "$cpu" | sed 's/^xscale/arm/')
+		;;
+	arm64-*)
+		cpu=aarch64
 		;;
 
 	# Recognize the canonical CPU Types that limit and/or modify the
 	# company names they are paired with.
 	cr16-*)
-		os=${os:-elf}
+		basic_os=${basic_os:-elf}
 		;;
 	crisv32-* | etraxfs*-*)
 		cpu=crisv32
@@ -1115,7 +1122,7 @@ case $cpu-$vendor in
 		vendor=axis
 		;;
 	crx-*)
-		os=${os:-elf}
+		basic_os=${basic_os:-elf}
 		;;
 	neo-tandem)
 		cpu=neo
@@ -1137,16 +1144,12 @@ case $cpu-$vendor in
 		cpu=nsx
 		vendor=tandem
 		;;
-	s390-*)
-		cpu=s390
-		vendor=ibm
-		;;
-	s390x-*)
-		cpu=s390x
-		vendor=ibm
+	mipsallegrexel-sony)
+		cpu=mipsallegrexel
+		vendor=sony
 		;;
 	tile*-*)
-		os=${os:-linux-gnu}
+		basic_os=${basic_os:-linux-gnu}
 		;;
 
 	*)
@@ -1161,13 +1164,14 @@ case $cpu-$vendor in
 			| alpha64 | alpha64ev[4-8] | alpha64ev56 | alpha64ev6[78] \
 			| alphapca5[67] | alpha64pca5[67] \
 			| am33_2.0 \
-			| arc | arceb \
-			| arm  | arm[lb]e | arme[lb] | armv* \
+			| amdgcn \
+			| arc | arceb | arc64 \
+			| arm | arm[lb]e | arme[lb] | armv* \
 			| avr | avr32 \
 			| asmjs \
 			| ba \
 			| be32 | be64 \
-			| bfin | bs2000 \
+			| bfin | bpf | bs2000 \
 			| c[123]* | c30 | [cjt]90 | c4x \
 			| c8051 | clipper | craynv | csky | cydra \
 			| d10v | d30v | dlx | dsp16xx \
@@ -1181,14 +1185,15 @@ case $cpu-$vendor in
 			| k1om \
 			| le32 | le64 \
 			| lm32 \
+			| loongarch32 | loongarch64 | loongarchx32 \
 			| m32c | m32r | m32rle \
-			| m5200 | m68000 | m680[012346]0 | m68360 | m683?2 | m68k | v70 | w65 \
-			| m6811 | m68hc11 | m6812 | m68hc12 | m68hcs12x | nvptx | picochip \
+			| m5200 | m68000 | m680[012346]0 | m68360 | m683?2 | m68k \
+			| m6811 | m68hc11 | m6812 | m68hc12 | m68hcs12x \
 			| m88110 | m88k | maxq | mb | mcore | mep | metag \
 			| microblaze | microblazeel \
 			| mips | mipsbe | mipseb | mipsel | mipsle \
 			| mips16 \
-			| mips64 | mips64el \
+			| mips64 | mips64eb | mips64el \
 			| mips64octeon | mips64octeonel \
 			| mips64orion | mips64orionel \
 			| mips64r5900 | mips64r5900el \
@@ -1199,9 +1204,13 @@ case $cpu-$vendor in
 			| mips64vr5900 | mips64vr5900el \
 			| mipsisa32 | mipsisa32el \
 			| mipsisa32r2 | mipsisa32r2el \
+			| mipsisa32r3 | mipsisa32r3el \
+			| mipsisa32r5 | mipsisa32r5el \
 			| mipsisa32r6 | mipsisa32r6el \
 			| mipsisa64 | mipsisa64el \
 			| mipsisa64r2 | mipsisa64r2el \
+			| mipsisa64r3 | mipsisa64r3el \
+			| mipsisa64r5 | mipsisa64r5el \
 			| mipsisa64r6 | mipsisa64r6el \
 			| mipsisa64sb1 | mipsisa64sb1el \
 			| mipsisa64sr71k | mipsisa64sr71kel \
@@ -1215,32 +1224,37 @@ case $cpu-$vendor in
 			| nds32 | nds32le | nds32be \
 			| nfp \
 			| nios | nios2 | nios2eb | nios2el \
-			| none | np1 | ns16k | ns32k \
+			| none | np1 | ns16k | ns32k | nvptx \
 			| open8 \
 			| or1k* \
 			| or32 \
 			| orion \
+			| picochip \
 			| pdp10 | pdp11 | pj | pjl | pn | power \
 			| powerpc | powerpc64 | powerpc64le | powerpcle | powerpcspe \
 			| pru \
 			| pyramid \
-			| riscv | riscv32 | riscv64 \
+			| riscv | riscv32 | riscv32be | riscv64 | riscv64be \
 			| rl78 | romp | rs6000 | rx \
+			| s390 | s390x \
 			| score \
-			| sh | sh[1234] | sh[24]a | sh[24]ae[lb] | sh[23]e | she[lb] | sh[lb]e \
+			| sh | shl \
+			| sh[1234] | sh[24]a | sh[24]ae[lb] | sh[23]e | she[lb] | sh[lb]e \
 			| sh[1234]e[lb] |  sh[12345][lb]e | sh[23]ele | sh64 | sh64le \
 			| sparc | sparc64 | sparc64b | sparc64v | sparc86x | sparclet \
 			| sparclite \
 			| sparcv8 | sparcv9 | sparcv9b | sparcv9v | sv1 | sx* \
 			| spu \
 			| tahoe \
+			| thumbv7* \
 			| tic30 | tic4x | tic54x | tic55x | tic6x | tic80 \
 			| tron \
 			| ubicom32 \
-			| v850 | v850e | v850e1 | v850es | v850e2 | v850e2v3 \
+			| v70 | v850 | v850e | v850e1 | v850es | v850e2 | v850e2v3 \
 			| vax \
 			| visium \
-			| wasm32 \
+			| w65 \
+			| wasm32 | wasm64 \
 			| we32k \
 			| x86 | x86_64 | xc16x | xgate | xps100 \
 			| xstormy16 | xtensa* \
@@ -1270,8 +1284,47 @@ esac
 
 # Decode manufacturer-specific aliases for certain operating systems.
 
-if [ x$os != x ]
+if test x$basic_os != x
 then
+
+# First recognize some ad-hoc caes, or perhaps split kernel-os, or else just
+# set os.
+case $basic_os in
+	gnu/linux*)
+		kernel=linux
+		os=$(echo $basic_os | sed -e 's|gnu/linux|gnu|')
+		;;
+	os2-emx)
+		kernel=os2
+		os=$(echo $basic_os | sed -e 's|os2-emx|emx|')
+		;;
+	nto-qnx*)
+		kernel=nto
+		os=$(echo $basic_os | sed -e 's|nto-qnx|qnx|')
+		;;
+	*-*)
+		# shellcheck disable=SC2162
+		IFS="-" read kernel os <<EOF
+$basic_os
+EOF
+		;;
+	# Default OS when just kernel was specified
+	nto*)
+		kernel=nto
+		os=$(echo $basic_os | sed -e 's|nto|qnx|')
+		;;
+	linux*)
+		kernel=linux
+		os=$(echo $basic_os | sed -e 's|linux|gnu|')
+		;;
+	*)
+		kernel=
+		os=$basic_os
+		;;
+esac
+
+# Now, normalize the OS (knowing we just have one component, it's not a kernel,
+# etc.)
 case $os in
 	# First match some system type aliases that might get confused
 	# with valid system types.
@@ -1283,7 +1336,7 @@ case $os in
 		os=cnk
 		;;
 	solaris1 | solaris1.*)
-		os=`echo $os | sed -e 's|solaris1|sunos4|'`
+		os=$(echo $os | sed -e 's|solaris1|sunos4|')
 		;;
 	solaris)
 		os=solaris2
@@ -1291,9 +1344,6 @@ case $os in
 	unixware*)
 		os=sysv4.2uw
 		;;
-	gnu/linux*)
-		os=`echo $os | sed -e 's|gnu/linux|linux-gnu|'`
-		;;
 	# es1800 is here to avoid being matched by es* (a different OS)
 	es1800*)
 		os=ose
@@ -1315,12 +1365,9 @@ case $os in
 		os=sco3.2v4
 		;;
 	sco3.2.[4-9]*)
-		os=`echo $os | sed -e 's/sco3.2./sco3.2v/'`
-		;;
-	sco3.2v[4-9]* | sco5v6*)
-		# Don't forget version if it is 3.2v4 or newer.
+		os=$(echo $os | sed -e 's/sco3.2./sco3.2v/')
 		;;
-	scout)
+	sco*v* | scout)
 		# Don't match below
 		;;
 	sco*)
@@ -1329,78 +1376,26 @@ case $os in
 	psos*)
 		os=psos
 		;;
-	# Now accept the basic system types.
-	# The portable systems comes first.
-	# Each alternative MUST end in a * to match a version number.
-	# sysv* is not here because it comes later, after sysvr4.
-	gnu* | bsd* | mach* | minix* | genix* | ultrix* | irix* \
-	     | *vms* | esix* | aix* | cnk* | sunos | sunos[34]*\
-	     | hpux* | unos* | osf* | luna* | dgux* | auroraux* | solaris* \
-	     | sym* | kopensolaris* | plan9* \
-	     | amigaos* | amigados* | msdos* | newsos* | unicos* | aof* \
-	     | aos* | aros* | cloudabi* | sortix* \
-	     | nindy* | vxsim* | vxworks* | ebmon* | hms* | mvs* \
-	     | clix* | riscos* | uniplus* | iris* | isc* | rtu* | xenix* \
-	     | knetbsd* | mirbsd* | netbsd* \
-	     | bitrig* | openbsd* | solidbsd* | libertybsd* \
-	     | ekkobsd* | kfreebsd* | freebsd* | riscix* | lynxos* \
-	     | bosx* | nextstep* | cxux* | aout* | elf* | oabi* \
-	     | ptx* | coff* | ecoff* | winnt* | domain* | vsta* \
-	     | udi* | eabi* | lites* | ieee* | go32* | aux* | hcos* \
-	     | chorusrdb* | cegcc* | glidix* \
-	     | cygwin* | msys* | pe* | moss* | proelf* | rtems* \
-	     | midipix* | mingw32* | mingw64* | linux-gnu* | linux-android* \
-	     | linux-newlib* | linux-musl* | linux-uclibc* \
-	     | uxpv* | beos* | mpeix* | udk* | moxiebox* \
-	     | interix* | uwin* | mks* | rhapsody* | darwin* \
-	     | openstep* | oskit* | conix* | pw32* | nonstopux* \
-	     | storm-chaos* | tops10* | tenex* | tops20* | its* \
-	     | os2* | vos* | palmos* | uclinux* | nucleus* \
-	     | morphos* | superux* | rtmk* | windiss* \
-	     | powermax* | dnix* | nx6 | nx7 | sei* | dragonfly* \
-	     | skyos* | haiku* | rdos* | toppers* | drops* | es* \
-	     | onefs* | tirtos* | phoenix* | fuchsia* | redox* | bme* \
-	     | midnightbsd*)
-	# Remember, each alternative MUST END IN *, to match a version number.
-		;;
 	qnx*)
-		case $cpu in
-		    x86 | i*86)
-			;;
-		    *)
-			os=nto-$os
-			;;
-		esac
+		os=qnx
 		;;
 	hiux*)
 		os=hiuxwe2
 		;;
-	nto-qnx*)
-		;;
-	nto*)
-		os=`echo $os | sed -e 's|nto|nto-qnx|'`
-		;;
-	sim | xray | os68k* | v88r* \
-	    | windows* | osx | abug | netware* | os9* \
-	    | macos* | mpw* | magic* | mmixware* | mon960* | lnews*)
-		;;
-	linux-dietlibc)
-		os=linux-dietlibc
-		;;
-	linux*)
-		os=`echo $os | sed -e 's|linux|linux-gnu|'`
-		;;
 	lynx*178)
 		os=lynxos178
 		;;
 	lynx*5)
 		os=lynxos5
 		;;
+	lynxos*)
+		# don't get caught up in next wildcard
+		;;
 	lynx*)
 		os=lynxos
 		;;
-	mac*)
-		os=`echo "$os" | sed -e 's|mac|macos|'`
+	mac[0-9]*)
+		os=$(echo "$os" | sed -e 's|mac|macos|')
 		;;
 	opened*)
 		os=openedition
@@ -1409,10 +1404,10 @@ case $os in
 		os=os400
 		;;
 	sunos5*)
-		os=`echo "$os" | sed -e 's|sunos5|solaris2|'`
+		os=$(echo "$os" | sed -e 's|sunos5|solaris2|')
 		;;
 	sunos6*)
-		os=`echo "$os" | sed -e 's|sunos6|solaris3|'`
+		os=$(echo "$os" | sed -e 's|sunos6|solaris3|')
 		;;
 	wince*)
 		os=wince
@@ -1444,12 +1439,9 @@ case $os in
 	ns2)
 		os=nextstep2
 		;;
-	nsk*)
-		os=nsk
-		;;
 	# Preserve the version number of sinix5.
 	sinix5.*)
-		os=`echo $os | sed -e 's|sinix|sysv|'`
+		os=$(echo $os | sed -e 's|sinix|sysv|')
 		;;
 	sinix*)
 		os=sysv4
@@ -1472,18 +1464,12 @@ case $os in
 	sysvr4)
 		os=sysv4
 		;;
-	# This must come after sysvr4.
-	sysv*)
-		;;
 	ose*)
 		os=ose
 		;;
 	*mint | mint[0-9]* | *MiNT | MiNT[0-9]*)
 		os=mint
 		;;
-	zvmoe)
-		os=zvmoe
-		;;
 	dicos*)
 		os=dicos
 		;;
@@ -1500,19 +1486,11 @@ case $os in
 			;;
 		esac
 		;;
-	nacl*)
-		;;
-	ios)
-		;;
-	none)
-		;;
-	*-eabi)
-		;;
 	*)
-		echo Invalid configuration \`"$1"\': system \`"$os"\' not recognized 1>&2
-		exit 1
+		# No normalization, but not necessarily accepted, that comes below.
 		;;
 esac
+
 else
 
 # Here we handle the default operating systems that come with various machines.
@@ -1525,6 +1503,7 @@ else
 # will signal an error saying that MANUFACTURER isn't an operating
 # system, and we'll never get to this point.
 
+kernel=
 case $cpu-$vendor in
 	score-*)
 		os=elf
@@ -1536,7 +1515,8 @@ case $cpu-$vendor in
 		os=riscix1.2
 		;;
 	arm*-rebel)
-		os=linux
+		kernel=linux
+		os=gnu
 		;;
 	arm*-semi)
 		os=aout
@@ -1702,84 +1682,178 @@ case $cpu-$vendor in
 		os=none
 		;;
 esac
+
 fi
 
+# Now, validate our (potentially fixed-up) OS.
+case $os in
+	# Sometimes we do "kernel-libc", so those need to count as OSes.
+	musl* | newlib* | uclibc*)
+		;;
+	# Likewise for "kernel-abi"
+	eabi* | gnueabi*)
+		;;
+	# VxWorks passes extra cpu info in the 4th filed.
+	simlinux | simwindows | spe)
+		;;
+	# Now accept the basic system types.
+	# The portable systems comes first.
+	# Each alternative MUST end in a * to match a version number.
+	gnu* | android* | bsd* | mach* | minix* | genix* | ultrix* | irix* \
+	     | *vms* | esix* | aix* | cnk* | sunos | sunos[34]* \
+	     | hpux* | unos* | osf* | luna* | dgux* | auroraux* | solaris* \
+	     | sym* |  plan9* | psp* | sim* | xray* | os68k* | v88r* \
+	     | hiux* | abug | nacl* | netware* | windows* \
+	     | os9* | macos* | osx* | ios* \
+	     | mpw* | magic* | mmixware* | mon960* | lnews* \
+	     | amigaos* | amigados* | msdos* | newsos* | unicos* | aof* \
+	     | aos* | aros* | cloudabi* | sortix* | twizzler* \
+	     | nindy* | vxsim* | vxworks* | ebmon* | hms* | mvs* \
+	     | clix* | riscos* | uniplus* | iris* | isc* | rtu* | xenix* \
+	     | mirbsd* | netbsd* | dicos* | openedition* | ose* \
+	     | bitrig* | openbsd* | secbsd* | solidbsd* | libertybsd* | os108* \
+	     | ekkobsd* | freebsd* | riscix* | lynxos* | os400* \
+	     | bosx* | nextstep* | cxux* | aout* | elf* | oabi* \
+	     | ptx* | coff* | ecoff* | winnt* | domain* | vsta* \
+	     | udi* | lites* | ieee* | go32* | aux* | hcos* \
+	     | chorusrdb* | cegcc* | glidix* | serenity* \
+	     | cygwin* | msys* | pe* | moss* | proelf* | rtems* \
+	     | midipix* | mingw32* | mingw64* | mint* \
+	     | uxpv* | beos* | mpeix* | udk* | moxiebox* \
+	     | interix* | uwin* | mks* | rhapsody* | darwin* \
+	     | openstep* | oskit* | conix* | pw32* | nonstopux* \
+	     | storm-chaos* | tops10* | tenex* | tops20* | its* \
+	     | os2* | vos* | palmos* | uclinux* | nucleus* | morphos* \
+	     | scout* | superux* | sysv* | rtmk* | tpf* | windiss* \
+	     | powermax* | dnix* | nx6 | nx7 | sei* | dragonfly* \
+	     | skyos* | haiku* | rdos* | toppers* | drops* | es* \
+	     | onefs* | tirtos* | phoenix* | fuchsia* | redox* | bme* \
+	     | midnightbsd* | amdhsa* | unleashed* | emscripten* | wasi* \
+	     | nsk* | powerunix* | genode* | zvmoe* | qnx* | emx*)
+		;;
+	# This one is extra strict with allowed versions
+	sco3.2v2 | sco3.2v[4-9]* | sco5v6*)
+		# Don't forget version if it is 3.2v4 or newer.
+		;;
+	none)
+		;;
+	*)
+		echo Invalid configuration \`"$1"\': OS \`"$os"\' not recognized 1>&2
+		exit 1
+		;;
+esac
+
+# As a final step for OS-related things, validate the OS-kernel combination
+# (given a valid OS), if there is a kernel.
+case $kernel-$os in
+	linux-gnu* | linux-dietlibc* | linux-android* | linux-newlib* | linux-musl* | linux-uclibc* )
+		;;
+	uclinux-uclibc* )
+		;;
+	-dietlibc* | -newlib* | -musl* | -uclibc* )
+		# These are just libc implementations, not actual OSes, and thus
+		# require a kernel.
+		echo "Invalid configuration \`$1': libc \`$os' needs explicit kernel." 1>&2
+		exit 1
+		;;
+	kfreebsd*-gnu* | kopensolaris*-gnu*)
+		;;
+	vxworks-simlinux | vxworks-simwindows | vxworks-spe)
+		;;
+	nto-qnx*)
+		;;
+	os2-emx)
+		;;
+	*-eabi* | *-gnueabi*)
+		;;
+	-*)
+		# Blank kernel with real OS is always fine.
+		;;
+	*-*)
+		echo "Invalid configuration \`$1': Kernel \`$kernel' not known to work with OS \`$os'." 1>&2
+		exit 1
+		;;
+esac
+
 # Here we handle the case where we know the os, and the CPU type, but not the
 # manufacturer.  We pick the logical manufacturer.
 case $vendor in
 	unknown)
-		case $os in
-			riscix*)
+		case $cpu-$os in
+			*-riscix*)
 				vendor=acorn
 				;;
-			sunos*)
+			*-sunos*)
 				vendor=sun
 				;;
-			cnk*|-aix*)
+			*-cnk* | *-aix*)
 				vendor=ibm
 				;;
-			beos*)
+			*-beos*)
 				vendor=be
 				;;
-			hpux*)
+			*-hpux*)
 				vendor=hp
 				;;
-			mpeix*)
+			*-mpeix*)
 				vendor=hp
 				;;
-			hiux*)
+			*-hiux*)
 				vendor=hitachi
 				;;
-			unos*)
+			*-unos*)
 				vendor=crds
 				;;
-			dgux*)
+			*-dgux*)
 				vendor=dg
 				;;
-			luna*)
+			*-luna*)
 				vendor=omron
 				;;
-			genix*)
+			*-genix*)
 				vendor=ns
 				;;
-			clix*)
+			*-clix*)
 				vendor=intergraph
 				;;
-			mvs* | opened*)
+			*-mvs* | *-opened*)
+				vendor=ibm
+				;;
+			*-os400*)
 				vendor=ibm
 				;;
-			os400*)
+			s390-* | s390x-*)
 				vendor=ibm
 				;;
-			ptx*)
+			*-ptx*)
 				vendor=sequent
 				;;
-			tpf*)
+			*-tpf*)
 				vendor=ibm
 				;;
-			vxsim* | vxworks* | windiss*)
+			*-vxsim* | *-vxworks* | *-windiss*)
 				vendor=wrs
 				;;
-			aux*)
+			*-aux*)
 				vendor=apple
 				;;
-			hms*)
+			*-hms*)
 				vendor=hitachi
 				;;
-			mpw* | macos*)
+			*-mpw* | *-macos*)
 				vendor=apple
 				;;
-			*mint | mint[0-9]* | *MiNT | MiNT[0-9]*)
+			*-*mint | *-mint[0-9]* | *-*MiNT | *-MiNT[0-9]*)
 				vendor=atari
 				;;
-			vos*)
+			*-vos*)
 				vendor=stratus
 				;;
 		esac
 		;;
 esac
 
-echo "$cpu-$vendor-$os"
+echo "$cpu-$vendor-${kernel:+$kernel-}$os"
 exit
 
 # Local variables: