Land #800, update upstream config.sub and config.guess

1 files changed, 1019 insertions, 692 deletions

diff --git a/scripts/config.guess b/scripts/config.guess
index b82ee23..980b020 100644
--- a/scripts/config.guess
+++ b/scripts/config.guess
@@ -1,12 +1,14 @@
 #! /bin/sh
 # Attempt to guess a canonical system name.
-#   Copyright 1992-2015 Free Software Foundation, Inc.
+#   Copyright 1992-2022 Free Software Foundation, Inc.
 
-timestamp='2015-12-14'
+# shellcheck disable=SC2006,SC2268 # see below for rationale
+
+timestamp='2022-09-17'
 
 # 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
-# the Free Software Foundation; either version 3 of the License, or
+# the Free Software Foundation, either version 3 of the License, or
 # (at your option) any later version.
 #
 # This program is distributed in the hope that it will be useful, but
@@ -15,7 +17,7 @@ timestamp='2015-12-14'
 # General Public License for more details.
 #
 # You should have received a copy of the GNU General Public License
-# along with this program; if not, see <http://www.gnu.org/licenses/>.
+# along with this program; if not, see <https://www.gnu.org/licenses/>.
 #
 # As a special exception to the GNU General Public License, if you
 # distribute this file as part of a program that contains a
@@ -27,11 +29,19 @@ timestamp='2015-12-14'
 # Originally written by Per Bothner; maintained since 2000 by Ben Elliston.
 #
 # You can get the latest version of this script from:
-# http://git.savannah.gnu.org/gitweb/?p=config.git;a=blob_plain;f=config.guess;hb=HEAD
+# https://git.savannah.gnu.org/cgit/config.git/plain/config.guess
 #
 # Please send patches to <config-patches@gnu.org>.
 
 
+# The "shellcheck disable" line above the timestamp inhibits complaints
+# about features and limitations of the classic Bourne shell that were
+# superseded or lifted in POSIX.  However, this script identifies a wide
+# variety of pre-POSIX systems that do not have POSIX shells at all, and
+# even some reasonably current systems (Solaris 10 as case-in-point) still
+# have a pre-POSIX /bin/sh.
+
+
 me=`echo "$0" | sed -e 's,.*/,,'`
 
 usage="\
@@ -39,7 +49,7 @@ Usage: $0 [OPTION]
 
 Output the configuration name of the system \`$me' is run on.
 
-Operation modes:
+Options:
   -h, --help         print this help, then exit
   -t, --time-stamp   print date of last modification, then exit
   -v, --version      print version number, then exit
@@ -50,7 +60,7 @@ version="\
 GNU config.guess ($timestamp)
 
 Originally written by Per Bothner.
-Copyright 1992-2015 Free Software Foundation, Inc.
+Copyright 1992-2022 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."
@@ -84,7 +94,8 @@ if test $# != 0; then
   exit 1
 fi
 
-trap 'exit 1' 1 2 15
+# Just in case it came from the environment.
+GUESS=
 
 # CC_FOR_BUILD -- compiler used by this script. Note that the use of a
 # compiler to aid in system detection is discouraged as it requires
@@ -96,66 +107,90 @@ trap 'exit 1' 1 2 15
 
 # Portable tmp directory creation inspired by the Autoconf team.
 
-set_cc_for_build='
-trap "exitcode=\$?; (rm -f \$tmpfiles 2>/dev/null; rmdir \$tmp 2>/dev/null) && exit \$exitcode" 0 ;
-trap "rm -f \$tmpfiles 2>/dev/null; rmdir \$tmp 2>/dev/null; exit 1" 1 2 13 15 ;
-: ${TMPDIR=/tmp} ;
- { tmp=`(umask 077 && mktemp -d "$TMPDIR/cgXXXXXX") 2>/dev/null` && test -n "$tmp" && test -d "$tmp" ; } ||
- { test -n "$RANDOM" && tmp=$TMPDIR/cg$$-$RANDOM && (umask 077 && mkdir $tmp) ; } ||
- { tmp=$TMPDIR/cg-$$ && (umask 077 && mkdir $tmp) && echo "Warning: creating insecure temp directory" >&2 ; } ||
- { echo "$me: cannot create a temporary directory in $TMPDIR" >&2 ; exit 1 ; } ;
-dummy=$tmp/dummy ;
-tmpfiles="$dummy.c $dummy.o $dummy.rel $dummy" ;
-case $CC_FOR_BUILD,$HOST_CC,$CC in
- ,,)    echo "int x;" > $dummy.c ;
-        for c in cc gcc c89 c99 ; do
-          if ($c -c -o $dummy.o $dummy.c) >/dev/null 2>&1 ; then
-             CC_FOR_BUILD="$c"; break ;
-          fi ;
-        done ;
-        if test x"$CC_FOR_BUILD" = x ; then
-          CC_FOR_BUILD=no_compiler_found ;
-        fi
-        ;;
- ,,*)   CC_FOR_BUILD=$CC ;;
- ,*,*)  CC_FOR_BUILD=$HOST_CC ;;
-esac ; set_cc_for_build= ;'
+tmp=
+# shellcheck disable=SC2172
+trap 'test -z "$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
+    : "${TMPDIR=/tmp}"
+    # shellcheck disable=SC2039,SC3028
+    { tmp=`(umask 077 && mktemp -d "$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 $TMPDIR" >&2 ; exit 1 ; }
+    dummy=$tmp/dummy
+    case ${CC_FOR_BUILD-},${HOST_CC-},${CC-} in
+        ,,)    echo "int x;" > "$dummy.c"
+               for driver in cc gcc c89 c99 ; do
+                   if ($driver -c -o "$dummy.o" "$dummy.c") >/dev/null 2>&1 ; then
+                       CC_FOR_BUILD=$driver
+                       break
+                   fi
+               done
+               if test x"$CC_FOR_BUILD" = x ; then
+                   CC_FOR_BUILD=no_compiler_found
+               fi
+               ;;
+        ,,*)   CC_FOR_BUILD=$CC ;;
+        ,*,*)  CC_FOR_BUILD=$HOST_CC ;;
+    esac
+}
 
 # This is needed to find uname on a Pyramid OSx when run in the BSD universe.
 # (ghazi@noc.rutgers.edu 1994-08-24)
-if (test -f /.attbin/uname) >/dev/null 2>&1 ; then
+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_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
 
-        eval $set_cc_for_build
-        cat <<-EOF > $dummy.c
+        set_cc_for_build
+        cat <<-EOF > "$dummy.c"
         #include <features.h>
         #if defined(__UCLIBC__)
         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 $dummy.c 2>/dev/null | grep '^LIBC' | sed 's, ,,g'`
+        cc_set_libc=`$CC_FOR_BUILD -E "$dummy.c" 2>/dev/null | grep '^LIBC' | sed 's, ,,g'`
+        eval "$cc_set_libc"
+
+        # 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*,
@@ -167,29 +202,32 @@ 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 || \
+            /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
+        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 ;;
+            *) machine=$UNAME_MACHINE_ARCH-unknown ;;
         esac
         # The Operating System including object format, if it has switched
-        # to ELF recently, or will in the future.
-        case "${UNAME_MACHINE_ARCH}" in
-            arm*|earm*|i386|m68k|ns32k|sh3*|sparc|vax)
-                eval $set_cc_for_build
+        # to ELF recently (or will in the future) and ABI.
+        case $UNAME_MACHINE_ARCH in
+            earm*)
+                os=netbsdelf
+                ;;
+            arm*|i386|m68k|ns32k|sh3*|sparc|vax)
+                set_cc_for_build
                 if echo __ELF__ | $CC_FOR_BUILD -E - 2>/dev/null \
                         | grep -q __ELF__
                 then
@@ -205,10 +243,10 @@ case "${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
@@ -216,43 +254,68 @@ 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:
         # contains redundant information, the shorter form:
         # CPU_TYPE-MANUFACTURER-OPERATING_SYSTEM is used.
-        echo "${machine}-${os}${release}${abi}"
-        exit ;;
+        GUESS=$machine-${os}${release}${abi-}
+        ;;
     *:Bitrig:*:*)
         UNAME_MACHINE_ARCH=`arch | sed 's/Bitrig.//'`
-        echo ${UNAME_MACHINE_ARCH}-unknown-bitrig${UNAME_RELEASE}
-        exit ;;
+        GUESS=$UNAME_MACHINE_ARCH-unknown-bitrig$UNAME_RELEASE
+        ;;
     *:OpenBSD:*:*)
         UNAME_MACHINE_ARCH=`arch | sed 's/OpenBSD.//'`
-        echo ${UNAME_MACHINE_ARCH}-unknown-openbsd${UNAME_RELEASE}
-        exit ;;
+        GUESS=$UNAME_MACHINE_ARCH-unknown-openbsd$UNAME_RELEASE
+        ;;
+    *:SecBSD:*:*)
+        UNAME_MACHINE_ARCH=`arch | sed 's/SecBSD.//'`
+        GUESS=$UNAME_MACHINE_ARCH-unknown-secbsd$UNAME_RELEASE
+        ;;
+    *:LibertyBSD:*:*)
+        UNAME_MACHINE_ARCH=`arch | sed 's/^.*BSD\.//'`
+        GUESS=$UNAME_MACHINE_ARCH-unknown-libertybsd$UNAME_RELEASE
+        ;;
+    *:MidnightBSD:*:*)
+        GUESS=$UNAME_MACHINE-unknown-midnightbsd$UNAME_RELEASE
+        ;;
     *:ekkoBSD:*:*)
-        echo ${UNAME_MACHINE}-unknown-ekkobsd${UNAME_RELEASE}
-        exit ;;
+        GUESS=$UNAME_MACHINE-unknown-ekkobsd$UNAME_RELEASE
+        ;;
     *:SolidBSD:*:*)
-        echo ${UNAME_MACHINE}-unknown-solidbsd${UNAME_RELEASE}
-        exit ;;
+        GUESS=$UNAME_MACHINE-unknown-solidbsd$UNAME_RELEASE
+        ;;
+    *:OS108:*:*)
+        GUESS=$UNAME_MACHINE-unknown-os108_$UNAME_RELEASE
+        ;;
     macppc:MirBSD:*:*)
-        echo powerpc-unknown-mirbsd${UNAME_RELEASE}
-        exit ;;
+        GUESS=powerpc-unknown-mirbsd$UNAME_RELEASE
+        ;;
     *:MirBSD:*:*)
-        echo ${UNAME_MACHINE}-unknown-mirbsd${UNAME_RELEASE}
-        exit ;;
+        GUESS=$UNAME_MACHINE-unknown-mirbsd$UNAME_RELEASE
+        ;;
     *:Sortix:*:*)
-        echo ${UNAME_MACHINE}-unknown-sortix
-        exit ;;
+        GUESS=$UNAME_MACHINE-unknown-sortix
+        ;;
+    *:Twizzler:*:*)
+        GUESS=$UNAME_MACHINE-unknown-twizzler
+        ;;
+    *:Redox:*:*)
+        GUESS=$UNAME_MACHINE-unknown-redox
+        ;;
+    mips:OSF1:*.*)
+        GUESS=mips-dec-osf1
+        ;;
     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 $3}'`
@@ -266,163 +329,158 @@ case "${UNAME_MACHINE}:${UNAME_SYSTEM}:${UNAME_RELEASE}:${UNAME_VERSION}" in
         # 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
+        case $ALPHA_CPU_TYPE in
             "EV4 (21064)")
-                UNAME_MACHINE="alpha" ;;
+                UNAME_MACHINE=alpha ;;
             "EV4.5 (21064)")
-                UNAME_MACHINE="alpha" ;;
+                UNAME_MACHINE=alpha ;;
             "LCA4 (21066/21068)")
-                UNAME_MACHINE="alpha" ;;
+                UNAME_MACHINE=alpha ;;
             "EV5 (21164)")
-                UNAME_MACHINE="alphaev5" ;;
+                UNAME_MACHINE=alphaev5 ;;
             "EV5.6 (21164A)")
-                UNAME_MACHINE="alphaev56" ;;
+                UNAME_MACHINE=alphaev56 ;;
             "EV5.6 (21164PC)")
-                UNAME_MACHINE="alphapca56" ;;
+                UNAME_MACHINE=alphapca56 ;;
             "EV5.7 (21164PC)")
-                UNAME_MACHINE="alphapca57" ;;
+                UNAME_MACHINE=alphapca57 ;;
             "EV6 (21264)")
-                UNAME_MACHINE="alphaev6" ;;
+                UNAME_MACHINE=alphaev6 ;;
             "EV6.7 (21264A)")
-                UNAME_MACHINE="alphaev67" ;;
+                UNAME_MACHINE=alphaev67 ;;
             "EV6.8CB (21264C)")
-                UNAME_MACHINE="alphaev68" ;;
+                UNAME_MACHINE=alphaev68 ;;
             "EV6.8AL (21264B)")
-                UNAME_MACHINE="alphaev68" ;;
+                UNAME_MACHINE=alphaev68 ;;
             "EV6.8CX (21264D)")
-                UNAME_MACHINE="alphaev68" ;;
+                UNAME_MACHINE=alphaev68 ;;
             "EV6.9A (21264/EV69A)")
-                UNAME_MACHINE="alphaev69" ;;
+                UNAME_MACHINE=alphaev69 ;;
             "EV7 (21364)")
-                UNAME_MACHINE="alphaev7" ;;
+                UNAME_MACHINE=alphaev7 ;;
             "EV7.9 (21364A)")
-                UNAME_MACHINE="alphaev79" ;;
+                UNAME_MACHINE=alphaev79 ;;
         esac
         # A Pn.n version is a patched version.
         # A Vn.n version is a released version.
         # 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 $exitcode ;;
-    Alpha\ *:Windows_NT*:*)
-        # How do we know it's Interix rather than the generic POSIX subsystem?
-        # Should we change UNAME_MACHINE based on the output of uname instead
-        # of the specific Alpha model?
-        echo alpha-pc-interix
-        exit ;;
-    21064:Windows_NT:50:3)
-        echo alpha-dec-winnt3.5
-        exit ;;
+        OSF_REL=`echo "$UNAME_RELEASE" | sed -e 's/^[PVTX]//' | tr ABCDEFGHIJKLMNOPQRSTUVWXYZ abcdefghijklmnopqrstuvwxyz`
+        GUESS=$UNAME_MACHINE-dec-osf$OSF_REL
+        ;;
     Amiga*:UNIX_System_V:4.0:*)
-        echo m68k-unknown-sysv4
-        exit ;;
+        GUESS=m68k-unknown-sysv4
+        ;;
     *:[Aa]miga[Oo][Ss]:*:*)
-        echo ${UNAME_MACHINE}-unknown-amigaos
-        exit ;;
+        GUESS=$UNAME_MACHINE-unknown-amigaos
+        ;;
     *:[Mm]orph[Oo][Ss]:*:*)
-        echo ${UNAME_MACHINE}-unknown-morphos
-        exit ;;
+        GUESS=$UNAME_MACHINE-unknown-morphos
+        ;;
     *:OS/390:*:*)
-        echo i370-ibm-openedition
-        exit ;;
+        GUESS=i370-ibm-openedition
+        ;;
     *:z/VM:*:*)
-        echo s390-ibm-zvmoe
-        exit ;;
+        GUESS=s390-ibm-zvmoe
+        ;;
     *:OS400:*:*)
-        echo powerpc-ibm-os400
-        exit ;;
+        GUESS=powerpc-ibm-os400
+        ;;
     arm:RISC*:1.[012]*:*|arm:riscix:1.[012]*:*)
-        echo arm-acorn-riscix${UNAME_RELEASE}
-        exit ;;
+        GUESS=arm-acorn-riscix$UNAME_RELEASE
+        ;;
     arm*:riscos:*:*|arm*:RISCOS:*:*)
-        echo arm-unknown-riscos
-        exit ;;
+        GUESS=arm-unknown-riscos
+        ;;
     SR2?01:HI-UX/MPP:*:* | SR8000:HI-UX/MPP:*:*)
-        echo hppa1.1-hitachi-hiuxmpp
-        exit ;;
+        GUESS=hppa1.1-hitachi-hiuxmpp
+        ;;
     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
-                echo pyramid-pyramid-sysv3
-        else
-                echo pyramid-pyramid-bsd
-        fi
-        exit ;;
+        case `(/bin/universe) 2>/dev/null` in
+            att) GUESS=pyramid-pyramid-sysv3 ;;
+            *)   GUESS=pyramid-pyramid-bsd   ;;
+        esac
+        ;;
     NILE*:*:*:dcosx)
-        echo pyramid-pyramid-svr4
-        exit ;;
+        GUESS=pyramid-pyramid-svr4
+        ;;
     DRS?6000:unix:4.0:6*)
-        echo sparc-icl-nx6
-        exit ;;
+        GUESS=sparc-icl-nx6
+        ;;
     DRS?6000:UNIX_SV:4.2*:7* | DRS?6000:isis:4.2*:7*)
         case `/usr/bin/uname -p` in
-            sparc) echo sparc-icl-nx7; exit ;;
-        esac ;;
+            sparc) GUESS=sparc-icl-nx7 ;;
+        esac
+        ;;
     s390x:SunOS:*:*)
-        echo ${UNAME_MACHINE}-ibm-solaris2`echo ${UNAME_RELEASE}|sed -e 's/[^.]*//'`
-        exit ;;
+        SUN_REL=`echo "$UNAME_RELEASE" | sed -e 's/[^.]*//'`
+        GUESS=$UNAME_MACHINE-ibm-solaris2$SUN_REL
+        ;;
     sun4H:SunOS:5.*:*)
-        echo sparc-hal-solaris2`echo ${UNAME_RELEASE}|sed -e 's/[^.]*//'`
-        exit ;;
+        SUN_REL=`echo "$UNAME_RELEASE" | sed -e 's/[^.]*//'`
+        GUESS=sparc-hal-solaris2$SUN_REL
+        ;;
     sun4*:SunOS:5.*:* | tadpole*:SunOS:5.*:*)
-        echo sparc-sun-solaris2`echo ${UNAME_RELEASE}|sed -e 's/[^.]*//'`
-        exit ;;
+        SUN_REL=`echo "$UNAME_RELEASE" | sed -e 's/[^.]*//'`
+        GUESS=sparc-sun-solaris2$SUN_REL
+        ;;
     i86pc:AuroraUX:5.*:* | i86xen:AuroraUX:5.*:*)
-        echo i386-pc-auroraux${UNAME_RELEASE}
-        exit ;;
+        GUESS=i386-pc-auroraux$UNAME_RELEASE
+        ;;
     i86pc:SunOS:5.*:* | i86xen:SunOS:5.*:*)
-        eval $set_cc_for_build
-        SUN_ARCH="i386"
+        set_cc_for_build
+        SUN_ARCH=i386
         # If there is a compiler, see if it is configured for 64-bit objects.
         # Note that the Sun cc does not turn __LP64__ into 1 like gcc does.
         # This test works for both compilers.
-        if [ "$CC_FOR_BUILD" != 'no_compiler_found' ]; then
+        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) | \
+                (CCOPTS="" $CC_FOR_BUILD -m64 -E - 2>/dev/null) | \
                 grep IS_64BIT_ARCH >/dev/null
             then
-                SUN_ARCH="x86_64"
+                SUN_ARCH=x86_64
             fi
         fi
-        echo ${SUN_ARCH}-pc-solaris2`echo ${UNAME_RELEASE}|sed -e 's/[^.]*//'`
-        exit ;;
+        SUN_REL=`echo "$UNAME_RELEASE" | sed -e 's/[^.]*//'`
+        GUESS=$SUN_ARCH-pc-solaris2$SUN_REL
+        ;;
     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 ${UNAME_RELEASE}|sed -e 's/[^.]*//'`
-        exit ;;
+        SUN_REL=`echo "$UNAME_RELEASE" | sed -e 's/[^.]*//'`
+        GUESS=sparc-sun-solaris3$SUN_REL
+        ;;
     sun4*:SunOS:*:*)
-        case "`/usr/bin/arch -k`" in
+        case `/usr/bin/arch -k` in
             Series*|S4*)
                 UNAME_RELEASE=`uname -v`
                 ;;
         esac
         # Japanese Language versions have a version number like `4.1.3-JL'.
-        echo sparc-sun-sunos`echo ${UNAME_RELEASE}|sed -e 's/-/_/'`
-        exit ;;
+        SUN_REL=`echo "$UNAME_RELEASE" | sed -e 's/-/_/'`
+        GUESS=sparc-sun-sunos$SUN_REL
+        ;;
     sun3*:SunOS:*:*)
-        echo m68k-sun-sunos${UNAME_RELEASE}
-        exit ;;
+        GUESS=m68k-sun-sunos$UNAME_RELEASE
+        ;;
     sun*:*:4.2BSD:*)
         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
+        test "x$UNAME_RELEASE" = x && UNAME_RELEASE=3
+        case `/bin/arch` in
             sun3)
-                echo m68k-sun-sunos${UNAME_RELEASE}
+                GUESS=m68k-sun-sunos$UNAME_RELEASE
                 ;;
             sun4)
-                echo sparc-sun-sunos${UNAME_RELEASE}
+                GUESS=sparc-sun-sunos$UNAME_RELEASE
                 ;;
         esac
-        exit ;;
+        ;;
     aushp:SunOS:*:*)
-        echo sparc-auspex-sunos${UNAME_RELEASE}
-        exit ;;
+        GUESS=sparc-auspex-sunos$UNAME_RELEASE
+        ;;
     # The situation for MiNT is a little confusing.  The machine name
     # can be virtually everything (everything which is not
     # "atarist" or "atariste" at least should have a processor
@@ -432,44 +490,44 @@ case "${UNAME_MACHINE}:${UNAME_SYSTEM}:${UNAME_RELEASE}:${UNAME_VERSION}" in
     # MiNT.  But MiNT is downward compatible to TOS, so this should
     # be no problem.
     atarist[e]:*MiNT:*:* | atarist[e]:*mint:*:* | atarist[e]:*TOS:*:*)
-        echo m68k-atari-mint${UNAME_RELEASE}
-        exit ;;
+        GUESS=m68k-atari-mint$UNAME_RELEASE
+        ;;
     atari*:*MiNT:*:* | atari*:*mint:*:* | atarist[e]:*TOS:*:*)
-        echo m68k-atari-mint${UNAME_RELEASE}
-        exit ;;
+        GUESS=m68k-atari-mint$UNAME_RELEASE
+        ;;
     *falcon*:*MiNT:*:* | *falcon*:*mint:*:* | *falcon*:*TOS:*:*)
-        echo m68k-atari-mint${UNAME_RELEASE}
-        exit ;;
+        GUESS=m68k-atari-mint$UNAME_RELEASE
+        ;;
     milan*:*MiNT:*:* | milan*:*mint:*:* | *milan*:*TOS:*:*)
-        echo m68k-milan-mint${UNAME_RELEASE}
-        exit ;;
+        GUESS=m68k-milan-mint$UNAME_RELEASE
+        ;;
     hades*:*MiNT:*:* | hades*:*mint:*:* | *hades*:*TOS:*:*)
-        echo m68k-hades-mint${UNAME_RELEASE}
-        exit ;;
+        GUESS=m68k-hades-mint$UNAME_RELEASE
+        ;;
     *:*MiNT:*:* | *:*mint:*:* | *:*TOS:*:*)
-        echo m68k-unknown-mint${UNAME_RELEASE}
-        exit ;;
+        GUESS=m68k-unknown-mint$UNAME_RELEASE
+        ;;
     m68k:machten:*:*)
-        echo m68k-apple-machten${UNAME_RELEASE}
-        exit ;;
+        GUESS=m68k-apple-machten$UNAME_RELEASE
+        ;;
     powerpc:machten:*:*)
-        echo powerpc-apple-machten${UNAME_RELEASE}
-        exit ;;
+        GUESS=powerpc-apple-machten$UNAME_RELEASE
+        ;;
     RISC*:Mach:*:*)
-        echo mips-dec-mach_bsd4.3
-        exit ;;
+        GUESS=mips-dec-mach_bsd4.3
+        ;;
     RISC*:ULTRIX:*:*)
-        echo mips-dec-ultrix${UNAME_RELEASE}
-        exit ;;
+        GUESS=mips-dec-ultrix$UNAME_RELEASE
+        ;;
     VAX*:ULTRIX*:*:*)
-        echo vax-dec-ultrix${UNAME_RELEASE}
-        exit ;;
+        GUESS=vax-dec-ultrix$UNAME_RELEASE
+        ;;
     2020:CLIX:*:* | 2430:CLIX:*:*)
-        echo clipper-intergraph-clix${UNAME_RELEASE}
-        exit ;;
+        GUESS=clipper-intergraph-clix$UNAME_RELEASE
+        ;;
     mips:*:*:UMIPS | mips:*:*:RISCos)
-        eval $set_cc_for_build
-        sed 's/^        //' << EOF >$dummy.c
+        set_cc_for_build
+        sed 's/^        //' << EOF > "$dummy.c"
 #ifdef __cplusplus
 #include <stdio.h>  /* for printf() prototype */
         int main (int argc, char *argv[]) {
@@ -478,95 +536,96 @@ case "${UNAME_MACHINE}:${UNAME_SYSTEM}:${UNAME_RELEASE}:${UNAME_VERSION}" in
 #endif
         #if defined (host_mips) && defined (MIPSEB)
         #if defined (SYSTYPE_SYSV)
-          printf ("mips-mips-riscos%ssysv\n", argv[1]); exit (0);
+          printf ("mips-mips-riscos%ssysv\\n", argv[1]); exit (0);
         #endif
         #if defined (SYSTYPE_SVR4)
-          printf ("mips-mips-riscos%ssvr4\n", argv[1]); exit (0);
+          printf ("mips-mips-riscos%ssvr4\\n", argv[1]); exit (0);
         #endif
         #if defined (SYSTYPE_BSD43) || defined(SYSTYPE_BSD)
-          printf ("mips-mips-riscos%sbsd\n", argv[1]); exit (0);
+          printf ("mips-mips-riscos%sbsd\\n", argv[1]); exit (0);
         #endif
         #endif
           exit (-1);
         }
 EOF
-        $CC_FOR_BUILD -o $dummy $dummy.c &&
-          dummyarg=`echo "${UNAME_RELEASE}" | sed -n 's/\([0-9]*\).*/\1/p'` &&
-          SYSTEM_NAME=`$dummy $dummyarg` &&
+        $CC_FOR_BUILD -o "$dummy" "$dummy.c" &&
+          dummyarg=`echo "$UNAME_RELEASE" | sed -n 's/\([0-9]*\).*/\1/p'` &&
+          SYSTEM_NAME=`"$dummy" "$dummyarg"` &&
             { echo "$SYSTEM_NAME"; exit; }
-        echo mips-mips-riscos${UNAME_RELEASE}
-        exit ;;
+        GUESS=mips-mips-riscos$UNAME_RELEASE
+        ;;
     Motorola:PowerMAX_OS:*:*)
-        echo powerpc-motorola-powermax
-        exit ;;
+        GUESS=powerpc-motorola-powermax
+        ;;
     Motorola:*:4.3:PL8-*)
-        echo powerpc-harris-powermax
-        exit ;;
+        GUESS=powerpc-harris-powermax
+        ;;
     Night_Hawk:*:*:PowerMAX_OS | Synergy:PowerMAX_OS:*:*)
-        echo powerpc-harris-powermax
-        exit ;;
+        GUESS=powerpc-harris-powermax
+        ;;
     Night_Hawk:Power_UNIX:*:*)
-        echo powerpc-harris-powerunix
-        exit ;;
+        GUESS=powerpc-harris-powerunix
+        ;;
     m88k:CX/UX:7*:*)
-        echo m88k-harris-cxux7
-        exit ;;
+        GUESS=m88k-harris-cxux7
+        ;;
     m88k:*:4*:R4*)
-        echo m88k-motorola-sysv4
-        exit ;;
+        GUESS=m88k-motorola-sysv4
+        ;;
     m88k:*:3*:R3*)
-        echo m88k-motorola-sysv3
-        exit ;;
+        GUESS=m88k-motorola-sysv3
+        ;;
     AViiON:dgux:*:*)
         # DG/UX returns AViiON for all architectures
         UNAME_PROCESSOR=`/usr/bin/uname -p`
-        if [ $UNAME_PROCESSOR = mc88100 ] || [ $UNAME_PROCESSOR = mc88110 ]
+        if test "$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}
+                GUESS=m88k-dg-dgux$UNAME_RELEASE
             else
-                echo m88k-dg-dguxbcs${UNAME_RELEASE}
+                GUESS=m88k-dg-dguxbcs$UNAME_RELEASE
             fi
         else
-            echo i586-dg-dgux${UNAME_RELEASE}
+            GUESS=i586-dg-dgux$UNAME_RELEASE
         fi
-        exit ;;
+        ;;
     M88*:DolphinOS:*:*) # DolphinOS (SVR3)
-        echo m88k-dolphin-sysv3
-        exit ;;
+        GUESS=m88k-dolphin-sysv3
+        ;;
     M88*:*:R3*:*)
         # Delta 88k system running SVR3
-        echo m88k-motorola-sysv3
-        exit ;;
+        GUESS=m88k-motorola-sysv3
+        ;;
     XD88*:*:*:*) # Tektronix XD88 system running UTekV (SVR3)
-        echo m88k-tektronix-sysv3
-        exit ;;
+        GUESS=m88k-tektronix-sysv3
+        ;;
     Tek43[0-9][0-9]:UTek:*:*) # Tektronix 4300 system running UTek (BSD)
-        echo m68k-tektronix-bsd
-        exit ;;
+        GUESS=m68k-tektronix-bsd
+        ;;
     *:IRIX*:*:*)
-        echo mips-sgi-irix`echo ${UNAME_RELEASE}|sed -e 's/-/_/g'`
-        exit ;;
+        IRIX_REL=`echo "$UNAME_RELEASE" | sed -e 's/-/_/g'`
+        GUESS=mips-sgi-irix$IRIX_REL
+        ;;
     ????????:AIX?:[12].1:2)   # AIX 2.2.1 or AIX 2.1.1 is RT/PC AIX.
-        echo romp-ibm-aix     # uname -m gives an 8 hex-code CPU id
-        exit ;;               # Note that: echo "'`uname -s`'" gives 'AIX '
+        GUESS=romp-ibm-aix    # uname -m gives an 8 hex-code CPU id
+        ;;                    # Note that: echo "'`uname -s`'" gives 'AIX '
     i*86:AIX:*:*)
-        echo i386-ibm-aix
-        exit ;;
+        GUESS=i386-ibm-aix
+        ;;
     ia64:AIX:*:*)
-        if [ -x /usr/bin/oslevel ] ; then
+        if test -x /usr/bin/oslevel ; then
                 IBM_REV=`/usr/bin/oslevel`
         else
-                IBM_REV=${UNAME_VERSION}.${UNAME_RELEASE}
+                IBM_REV=$UNAME_VERSION.$UNAME_RELEASE
         fi
-        echo ${UNAME_MACHINE}-ibm-aix${IBM_REV}
-        exit ;;
+        GUESS=$UNAME_MACHINE-ibm-aix$IBM_REV
+        ;;
     *:AIX:2:3)
         if grep bos325 /usr/include/stdio.h >/dev/null 2>&1; then
-                eval $set_cc_for_build
-                sed 's/^                //' << EOF >$dummy.c
+                set_cc_for_build
+                sed 's/^                //' << EOF > "$dummy.c"
                 #include <sys/systemcfg.h>
 
                 main()
@@ -577,77 +636,77 @@ 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 "$SYSTEM_NAME"
+                        GUESS=$SYSTEM_NAME
                 else
-                        echo rs6000-ibm-aix3.2.5
+                        GUESS=rs6000-ibm-aix3.2.5
                 fi
         elif grep bos324 /usr/include/stdio.h >/dev/null 2>&1; then
-                echo rs6000-ibm-aix3.2.4
+                GUESS=rs6000-ibm-aix3.2.4
         else
-                echo rs6000-ibm-aix3.2
+                GUESS=rs6000-ibm-aix3.2
         fi
-        exit ;;
+        ;;
     *:AIX:*:[4567])
         IBM_CPU_ID=`/usr/sbin/lsdev -C -c processor -S available | sed 1q | awk '{ print $1 }'`
-        if /usr/sbin/lsattr -El ${IBM_CPU_ID} | grep ' POWER' >/dev/null 2>&1; then
+        if /usr/sbin/lsattr -El "$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 |
+        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}
+                IBM_REV=$UNAME_VERSION.$UNAME_RELEASE
         fi
-        echo ${IBM_ARCH}-ibm-aix${IBM_REV}
-        exit ;;
+        GUESS=$IBM_ARCH-ibm-aix$IBM_REV
+        ;;
     *:AIX:*:*)
-        echo rs6000-ibm-aix
-        exit ;;
-    ibmrt:4.4BSD:*|romp-ibm:BSD:*)
-        echo romp-ibm-bsd4.4
-        exit ;;
+        GUESS=rs6000-ibm-aix
+        ;;
+    ibmrt:4.4BSD:*|romp-ibm:4.4BSD:*)
+        GUESS=romp-ibm-bsd4.4
+        ;;
     ibmrt:*BSD:*|romp-ibm:BSD:*)            # covers RT/PC BSD and
-        echo romp-ibm-bsd${UNAME_RELEASE}   # 4.3 with uname added to
-        exit ;;                             # report: romp-ibm BSD 4.3
+        GUESS=romp-ibm-bsd$UNAME_RELEASE    # 4.3 with uname added to
+        ;;                                  # report: romp-ibm BSD 4.3
     *:BOSX:*:*)
-        echo rs6000-bull-bosx
-        exit ;;
+        GUESS=rs6000-bull-bosx
+        ;;
     DPX/2?00:B.O.S.:*:*)
-        echo m68k-bull-sysv3
-        exit ;;
+        GUESS=m68k-bull-sysv3
+        ;;
     9000/[34]??:4.3bsd:1.*:*)
-        echo m68k-hp-bsd
-        exit ;;
+        GUESS=m68k-hp-bsd
+        ;;
     hp300:4.4BSD:*:* | 9000/[34]??:4.3bsd:2.*:*)
-        echo m68k-hp-bsd4.4
-        exit ;;
+        GUESS=m68k-hp-bsd4.4
+        ;;
     9000/[34678]??:HP-UX:*:*)
-        HPUX_REV=`echo ${UNAME_RELEASE}|sed -e 's/[^.]*.[0B]*//'`
-        case "${UNAME_MACHINE}" in
-            9000/31? )            HP_ARCH=m68000 ;;
-            9000/[34]?? )         HP_ARCH=m68k ;;
+        HPUX_REV=`echo "$UNAME_RELEASE" | sed -e 's/[^.]*.[0B]*//'`
+        case $UNAME_MACHINE in
+            9000/31?)            HP_ARCH=m68000 ;;
+            9000/[34]??)         HP_ARCH=m68k ;;
             9000/[678][0-9][0-9])
-                if [ -x /usr/bin/getconf ]; then
+                if test -x /usr/bin/getconf; then
                     sc_cpu_version=`/usr/bin/getconf SC_CPU_VERSION 2>/dev/null`
                     sc_kernel_bits=`/usr/bin/getconf SC_KERNEL_BITS 2>/dev/null`
-                    case "${sc_cpu_version}" in
-                      523) HP_ARCH="hppa1.0" ;; # CPU_PA_RISC1_0
-                      528) HP_ARCH="hppa1.1" ;; # CPU_PA_RISC1_1
+                    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
-                          32) HP_ARCH="hppa2.0n" ;;
-                          64) HP_ARCH="hppa2.0w" ;;
-                          '') HP_ARCH="hppa2.0" ;;   # HP-UX 10.20
+                        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
-                    eval $set_cc_for_build
-                    sed 's/^            //' << EOF >$dummy.c
+                if test "$HP_ARCH" = ""; then
+                    set_cc_for_build
+                    sed 's/^            //' << EOF > "$dummy.c"
 
                 #define _HPUX_SOURCE
                 #include <stdlib.h>
@@ -680,13 +739,13 @@ 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
-            eval $set_cc_for_build
+            set_cc_for_build
 
             # hppa2.0w-hp-hpux* has a 64-bit kernel and a compiler generating
             # 32-bit code.  hppa64-hp-hpux* has the same kernel and a compiler
@@ -697,23 +756,23 @@ EOF
             # $ CC_FOR_BUILD="cc +DA2.0w" ./config.guess
             # => hppa64-hp-hpux11.23
 
-            if echo __LP64__ | (CCOPTS= $CC_FOR_BUILD -E - 2>/dev/null) |
+            if echo __LP64__ | (CCOPTS="" $CC_FOR_BUILD -E - 2>/dev/null) |
                 grep -q __LP64__
             then
-                HP_ARCH="hppa2.0w"
+                HP_ARCH=hppa2.0w
             else
-                HP_ARCH="hppa64"
+                HP_ARCH=hppa64
             fi
         fi
-        echo ${HP_ARCH}-hp-hpux${HPUX_REV}
-        exit ;;
+        GUESS=$HP_ARCH-hp-hpux$HPUX_REV
+        ;;
     ia64:HP-UX:*:*)
-        HPUX_REV=`echo ${UNAME_RELEASE}|sed -e 's/[^.]*.[0B]*//'`
-        echo ia64-hp-hpux${HPUX_REV}
-        exit ;;
+        HPUX_REV=`echo "$UNAME_RELEASE" | sed -e 's/[^.]*.[0B]*//'`
+        GUESS=ia64-hp-hpux$HPUX_REV
+        ;;
     3050*:HI-UX:*:*)
-        eval $set_cc_for_build
-        sed 's/^        //' << EOF >$dummy.c
+        set_cc_for_build
+        sed 's/^        //' << EOF > "$dummy.c"
         #include <unistd.h>
         int
         main ()
@@ -738,38 +797,38 @@ 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 ;;
-    9000/7??:4.3bsd:*:* | 9000/8?[79]:4.3bsd:*:* )
-        echo hppa1.1-hp-bsd
-        exit ;;
+        GUESS=unknown-hitachi-hiuxwe2
+        ;;
+    9000/7??:4.3bsd:*:* | 9000/8?[79]:4.3bsd:*:*)
+        GUESS=hppa1.1-hp-bsd
+        ;;
     9000/8??:4.3bsd:*:*)
-        echo hppa1.0-hp-bsd
-        exit ;;
+        GUESS=hppa1.0-hp-bsd
+        ;;
     *9??*:MPE/iX:*:* | *3000*:MPE/iX:*:*)
-        echo hppa1.0-hp-mpeix
-        exit ;;
-    hp7??:OSF1:*:* | hp8?[79]:OSF1:*:* )
-        echo hppa1.1-hp-osf
-        exit ;;
+        GUESS=hppa1.0-hp-mpeix
+        ;;
+    hp7??:OSF1:*:* | hp8?[79]:OSF1:*:*)
+        GUESS=hppa1.1-hp-osf
+        ;;
     hp8??:OSF1:*:*)
-        echo hppa1.0-hp-osf
-        exit ;;
+        GUESS=hppa1.0-hp-osf
+        ;;
     i*86:OSF1:*:*)
-        if [ -x /usr/sbin/sysversion ] ; then
-            echo ${UNAME_MACHINE}-unknown-osf1mk
+        if test -x /usr/sbin/sysversion ; then
+            GUESS=$UNAME_MACHINE-unknown-osf1mk
         else
-            echo ${UNAME_MACHINE}-unknown-osf1
+            GUESS=$UNAME_MACHINE-unknown-osf1
         fi
-        exit ;;
+        ;;
     parisc*:Lites*:*:*)
-        echo hppa1.1-hp-lites
-        exit ;;
+        GUESS=hppa1.1-hp-lites
+        ;;
     C1*:ConvexOS:*:* | convex:ConvexOS:C1*:*)
-        echo c1-convex-bsd
-        exit ;;
+        GUESS=c1-convex-bsd
+        ;;
     C2*:ConvexOS:*:* | convex:ConvexOS:C2*:*)
         if getsysinfo -f scalar_acc
         then echo c32-convex-bsd
@@ -777,139 +836,154 @@ EOF
         fi
         exit ;;
     C34*:ConvexOS:*:* | convex:ConvexOS:C34*:*)
-        echo c34-convex-bsd
-        exit ;;
+        GUESS=c34-convex-bsd
+        ;;
     C38*:ConvexOS:*:* | convex:ConvexOS:C38*:*)
-        echo c38-convex-bsd
-        exit ;;
+        GUESS=c38-convex-bsd
+        ;;
     C4*:ConvexOS:*:* | convex:ConvexOS:C4*:*)
-        echo c4-convex-bsd
-        exit ;;
+        GUESS=c4-convex-bsd
+        ;;
     CRAY*Y-MP:*:*:*)
-        echo ymp-cray-unicos${UNAME_RELEASE} | sed -e 's/\.[^.]*$/.X/'
-        exit ;;
+        CRAY_REL=`echo "$UNAME_RELEASE" | sed -e 's/\.[^.]*$/.X/'`
+        GUESS=ymp-cray-unicos$CRAY_REL
+        ;;
     CRAY*[A-Z]90:*:*:*)
-        echo ${UNAME_MACHINE}-cray-unicos${UNAME_RELEASE} \
+        echo "$UNAME_MACHINE"-cray-unicos"$UNAME_RELEASE" \
         | sed -e 's/CRAY.*\([A-Z]90\)/\1/' \
               -e y/ABCDEFGHIJKLMNOPQRSTUVWXYZ/abcdefghijklmnopqrstuvwxyz/ \
               -e 's/\.[^.]*$/.X/'
         exit ;;
     CRAY*TS:*:*:*)
-        echo t90-cray-unicos${UNAME_RELEASE} | sed -e 's/\.[^.]*$/.X/'
-        exit ;;
+        CRAY_REL=`echo "$UNAME_RELEASE" | sed -e 's/\.[^.]*$/.X/'`
+        GUESS=t90-cray-unicos$CRAY_REL
+        ;;
     CRAY*T3E:*:*:*)
-        echo alphaev5-cray-unicosmk${UNAME_RELEASE} | sed -e 's/\.[^.]*$/.X/'
-        exit ;;
+        CRAY_REL=`echo "$UNAME_RELEASE" | sed -e 's/\.[^.]*$/.X/'`
+        GUESS=alphaev5-cray-unicosmk$CRAY_REL
+        ;;
     CRAY*SV1:*:*:*)
-        echo sv1-cray-unicos${UNAME_RELEASE} | sed -e 's/\.[^.]*$/.X/'
-        exit ;;
+        CRAY_REL=`echo "$UNAME_RELEASE" | sed -e 's/\.[^.]*$/.X/'`
+        GUESS=sv1-cray-unicos$CRAY_REL
+        ;;
     *:UNICOS/mp:*:*)
-        echo craynv-cray-unicosmp${UNAME_RELEASE} | sed -e 's/\.[^.]*$/.X/'
-        exit ;;
+        CRAY_REL=`echo "$UNAME_RELEASE" | sed -e 's/\.[^.]*$/.X/'`
+        GUESS=craynv-cray-unicosmp$CRAY_REL
+        ;;
     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 ${UNAME_RELEASE} | sed -e 's/ /_/'`
-        echo "${FUJITSU_PROC}-fujitsu-${FUJITSU_SYS}${FUJITSU_REL}"
-        exit ;;
+        FUJITSU_PROC=`uname -m | tr ABCDEFGHIJKLMNOPQRSTUVWXYZ abcdefghijklmnopqrstuvwxyz`
+        FUJITSU_SYS=`uname -p | tr ABCDEFGHIJKLMNOPQRSTUVWXYZ abcdefghijklmnopqrstuvwxyz | sed -e 's/\///'`
+        FUJITSU_REL=`echo "$UNAME_RELEASE" | sed -e 's/ /_/'`
+        GUESS=${FUJITSU_PROC}-fujitsu-${FUJITSU_SYS}${FUJITSU_REL}
+        ;;
     5000:UNIX_System_V:4.*:*)
-        FUJITSU_SYS=`uname -p | tr 'ABCDEFGHIJKLMNOPQRSTUVWXYZ' 'abcdefghijklmnopqrstuvwxyz' | sed -e 's/\///'`
-        FUJITSU_REL=`echo ${UNAME_RELEASE} | tr 'ABCDEFGHIJKLMNOPQRSTUVWXYZ' 'abcdefghijklmnopqrstuvwxyz' | sed -e 's/ /_/'`
-        echo "sparc-fujitsu-${FUJITSU_SYS}${FUJITSU_REL}"
-        exit ;;
+        FUJITSU_SYS=`uname -p | tr ABCDEFGHIJKLMNOPQRSTUVWXYZ abcdefghijklmnopqrstuvwxyz | sed -e 's/\///'`
+        FUJITSU_REL=`echo "$UNAME_RELEASE" | tr ABCDEFGHIJKLMNOPQRSTUVWXYZ abcdefghijklmnopqrstuvwxyz | sed -e 's/ /_/'`
+        GUESS=sparc-fujitsu-${FUJITSU_SYS}${FUJITSU_REL}
+        ;;
     i*86:BSD/386:*:* | i*86:BSD/OS:*:* | *:Ascend\ Embedded/OS:*:*)
-        echo ${UNAME_MACHINE}-pc-bsdi${UNAME_RELEASE}
-        exit ;;
+        GUESS=$UNAME_MACHINE-pc-bsdi$UNAME_RELEASE
+        ;;
     sparc*:BSD/OS:*:*)
-        echo sparc-unknown-bsdi${UNAME_RELEASE}
-        exit ;;
+        GUESS=sparc-unknown-bsdi$UNAME_RELEASE
+        ;;
     *:BSD/OS:*:*)
-        echo ${UNAME_MACHINE}-unknown-bsdi${UNAME_RELEASE}
-        exit ;;
+        GUESS=$UNAME_MACHINE-unknown-bsdi$UNAME_RELEASE
+        ;;
+    arm:FreeBSD:*:*)
+        UNAME_PROCESSOR=`uname -p`
+        set_cc_for_build
+        if echo __ARM_PCS_VFP | $CC_FOR_BUILD -E - 2>/dev/null \
+            | grep -q __ARM_PCS_VFP
+        then
+            FREEBSD_REL=`echo "$UNAME_RELEASE" | sed -e 's/[-(].*//'`
+            GUESS=$UNAME_PROCESSOR-unknown-freebsd$FREEBSD_REL-gnueabi
+        else
+            FREEBSD_REL=`echo "$UNAME_RELEASE" | sed -e 's/[-(].*//'`
+            GUESS=$UNAME_PROCESSOR-unknown-freebsd$FREEBSD_REL-gnueabihf
+        fi
+        ;;
     *:FreeBSD:*:*)
         UNAME_PROCESSOR=`/usr/bin/uname -p`
-        case ${UNAME_PROCESSOR} in
+        case $UNAME_PROCESSOR in
             amd64)
-                echo x86_64-unknown-freebsd`echo ${UNAME_RELEASE}|sed -e 's/[-(].*//'` ;;
-            *)
-                echo ${UNAME_PROCESSOR}-unknown-freebsd`echo ${UNAME_RELEASE}|sed -e 's/[-(].*//'` ;;
+                UNAME_PROCESSOR=x86_64 ;;
+            i386)
+                UNAME_PROCESSOR=i586 ;;
         esac
-        exit ;;
+        FREEBSD_REL=`echo "$UNAME_RELEASE" | sed -e 's/[-(].*//'`
+        GUESS=$UNAME_PROCESSOR-unknown-freebsd$FREEBSD_REL
+        ;;
     i*:CYGWIN*:*)
-        echo ${UNAME_MACHINE}-pc-cygwin
-        exit ;;
+        GUESS=$UNAME_MACHINE-pc-cygwin
+        ;;
     *:MINGW64*:*)
-        echo ${UNAME_MACHINE}-pc-mingw64
-        exit ;;
+        GUESS=$UNAME_MACHINE-pc-mingw64
+        ;;
     *:MINGW*:*)
-        echo ${UNAME_MACHINE}-pc-mingw32
-        exit ;;
+        GUESS=$UNAME_MACHINE-pc-mingw32
+        ;;
     *:MSYS*:*)
-        echo ${UNAME_MACHINE}-pc-msys
-        exit ;;
-    i*:windows32*:*)
-        # uname -m includes "-pc" on this system.
-        echo ${UNAME_MACHINE}-mingw32
-        exit ;;
+        GUESS=$UNAME_MACHINE-pc-msys
+        ;;
     i*:PW*:*)
-        echo ${UNAME_MACHINE}-pc-pw32
-        exit ;;
+        GUESS=$UNAME_MACHINE-pc-pw32
+        ;;
+    *:SerenityOS:*:*)
+        GUESS=$UNAME_MACHINE-pc-serenity
+        ;;
     *:Interix*:*)
-        case ${UNAME_MACHINE} in
+        case $UNAME_MACHINE in
             x86)
-                echo i586-pc-interix${UNAME_RELEASE}
-                exit ;;
+                GUESS=i586-pc-interix$UNAME_RELEASE
+                ;;
             authenticamd | genuineintel | EM64T)
-                echo x86_64-unknown-interix${UNAME_RELEASE}
-                exit ;;
+                GUESS=x86_64-unknown-interix$UNAME_RELEASE
+                ;;
             IA64)
-                echo ia64-unknown-interix${UNAME_RELEASE}
-                exit ;;
+                GUESS=ia64-unknown-interix$UNAME_RELEASE
+                ;;
         esac ;;
-    [345]86:Windows_95:* | [345]86:Windows_98:* | [345]86:Windows_NT:*)
-        echo i${UNAME_MACHINE}-pc-mks
-        exit ;;
-    8664:Windows_NT:*)
-        echo x86_64-pc-mks
-        exit ;;
-    i*:Windows_NT*:* | Pentium*:Windows_NT*:*)
-        # How do we know it's Interix rather than the generic POSIX subsystem?
-        # It also conflicts with pre-2.0 versions of AT&T UWIN. Should we
-        # UNAME_MACHINE based on the output of uname instead of i386?
-        echo i586-pc-interix
-        exit ;;
     i*:UWIN*:*)
-        echo ${UNAME_MACHINE}-pc-uwin
-        exit ;;
+        GUESS=$UNAME_MACHINE-pc-uwin
+        ;;
     amd64:CYGWIN*:*:* | x86_64:CYGWIN*:*:*)
-        echo x86_64-unknown-cygwin
-        exit ;;
-    p*:CYGWIN*:*)
-        echo powerpcle-unknown-cygwin
-        exit ;;
+        GUESS=x86_64-pc-cygwin
+        ;;
     prep*:SunOS:5.*:*)
-        echo powerpcle-unknown-solaris2`echo ${UNAME_RELEASE}|sed -e 's/[^.]*//'`
-        exit ;;
+        SUN_REL=`echo "$UNAME_RELEASE" | sed -e 's/[^.]*//'`
+        GUESS=powerpcle-unknown-solaris2$SUN_REL
+        ;;
     *:GNU:*:*)
         # the GNU system
-        echo `echo ${UNAME_MACHINE}|sed -e 's,[-/].*$,,'`-unknown-${LIBC}`echo ${UNAME_RELEASE}|sed -e 's,/.*$,,'`
-        exit ;;
+        GNU_ARCH=`echo "$UNAME_MACHINE" | sed -e 's,[-/].*$,,'`
+        GNU_REL=`echo "$UNAME_RELEASE" | sed -e 's,/.*$,,'`
+        GUESS=$GNU_ARCH-unknown-$LIBC$GNU_REL
+        ;;
     *:GNU/*:*:*)
         # other systems with GNU libc and userland
-        echo ${UNAME_MACHINE}-unknown-`echo ${UNAME_SYSTEM} | sed 's,^[^/]*/,,' | tr '[A-Z]' '[a-z]'``echo ${UNAME_RELEASE}|sed -e 's/[-(].*//'`-${LIBC}
-        exit ;;
-    i*86:Minix:*:*)
-        echo ${UNAME_MACHINE}-pc-minix
-        exit ;;
+        GNU_SYS=`echo "$UNAME_SYSTEM" | sed 's,^[^/]*/,,' | tr "[:upper:]" "[:lower:]"`
+        GNU_REL=`echo "$UNAME_RELEASE" | sed -e 's/[-(].*//'`
+        GUESS=$UNAME_MACHINE-unknown-$GNU_SYS$GNU_REL-$LIBC
+        ;;
+    x86_64:[Mm]anagarm:*:*|i?86:[Mm]anagarm:*:*)
+        GUESS="$UNAME_MACHINE-pc-managarm-mlibc"
+        ;;
+    *:[Mm]anagarm:*:*)
+        GUESS="$UNAME_MACHINE-unknown-managarm-mlibc"
+        ;;
+    *:Minix:*:*)
+        GUESS=$UNAME_MACHINE-unknown-minix
+        ;;
     aarch64:Linux:*:*)
-        echo ${UNAME_MACHINE}-unknown-linux-${LIBC}
-        exit ;;
+        GUESS=$UNAME_MACHINE-unknown-linux-$LIBC
+        ;;
     aarch64_be:Linux:*:*)
         UNAME_MACHINE=aarch64_be
-        echo ${UNAME_MACHINE}-unknown-linux-${LIBC}
-        exit ;;
+        GUESS=$UNAME_MACHINE-unknown-linux-$LIBC
+        ;;
     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 ;;
@@ -919,178 +993,237 @@ EOF
           EV68*) UNAME_MACHINE=alphaev68 ;;
         esac
         objdump --private-headers /bin/sh | grep -q ld.so.1
-        if test "$?" = 0 ; then LIBC="gnulibc1" ; fi
-        echo ${UNAME_MACHINE}-unknown-linux-${LIBC}
-        exit ;;
-    arc:Linux:*:* | arceb:Linux:*:*)
-        echo ${UNAME_MACHINE}-unknown-linux-${LIBC}
-        exit ;;
+        if test "$?" = 0 ; then LIBC=gnulibc1 ; fi
+        GUESS=$UNAME_MACHINE-unknown-linux-$LIBC
+        ;;
+    arc:Linux:*:* | arceb:Linux:*:* | arc32:Linux:*:* | arc64:Linux:*:*)
+        GUESS=$UNAME_MACHINE-unknown-linux-$LIBC
+        ;;
     arm*:Linux:*:*)
-        eval $set_cc_for_build
+        set_cc_for_build
         if echo __ARM_EABI__ | $CC_FOR_BUILD -E - 2>/dev/null \
             | grep -q __ARM_EABI__
         then
-            echo ${UNAME_MACHINE}-unknown-linux-${LIBC}
+            GUESS=$UNAME_MACHINE-unknown-linux-$LIBC
         else
             if echo __ARM_PCS_VFP | $CC_FOR_BUILD -E - 2>/dev/null \
                 | grep -q __ARM_PCS_VFP
             then
-                echo ${UNAME_MACHINE}-unknown-linux-${LIBC}eabi
+                GUESS=$UNAME_MACHINE-unknown-linux-${LIBC}eabi
             else
-                echo ${UNAME_MACHINE}-unknown-linux-${LIBC}eabihf
+                GUESS=$UNAME_MACHINE-unknown-linux-${LIBC}eabihf
             fi
         fi
-        exit ;;
+        ;;
     avr32*:Linux:*:*)
-        echo ${UNAME_MACHINE}-unknown-linux-${LIBC}
-        exit ;;
+        GUESS=$UNAME_MACHINE-unknown-linux-$LIBC
+        ;;
     cris:Linux:*:*)
-        echo ${UNAME_MACHINE}-axis-linux-${LIBC}
-        exit ;;
+        GUESS=$UNAME_MACHINE-axis-linux-$LIBC
+        ;;
     crisv32:Linux:*:*)
-        echo ${UNAME_MACHINE}-axis-linux-${LIBC}
-        exit ;;
+        GUESS=$UNAME_MACHINE-axis-linux-$LIBC
+        ;;
     e2k:Linux:*:*)
-        echo ${UNAME_MACHINE}-unknown-linux-${LIBC}
-        exit ;;
+        GUESS=$UNAME_MACHINE-unknown-linux-$LIBC
+        ;;
     frv:Linux:*:*)
-        echo ${UNAME_MACHINE}-unknown-linux-${LIBC}
-        exit ;;
+        GUESS=$UNAME_MACHINE-unknown-linux-$LIBC
+        ;;
     hexagon:Linux:*:*)
-        echo ${UNAME_MACHINE}-unknown-linux-${LIBC}
-        exit ;;
+        GUESS=$UNAME_MACHINE-unknown-linux-$LIBC
+        ;;
     i*86:Linux:*:*)
-        echo ${UNAME_MACHINE}-pc-linux-${LIBC}
-        exit ;;
+        GUESS=$UNAME_MACHINE-pc-linux-$LIBC
+        ;;
     ia64:Linux:*:*)
-        echo ${UNAME_MACHINE}-unknown-linux-${LIBC}
-        exit ;;
+        GUESS=$UNAME_MACHINE-unknown-linux-$LIBC
+        ;;
     k1om:Linux:*:*)
-        echo ${UNAME_MACHINE}-unknown-linux-${LIBC}
-        exit ;;
+        GUESS=$UNAME_MACHINE-unknown-linux-$LIBC
+        ;;
+    loongarch32:Linux:*:* | loongarch64:Linux:*:*)
+        GUESS=$UNAME_MACHINE-unknown-linux-$LIBC
+        ;;
     m32r*:Linux:*:*)
-        echo ${UNAME_MACHINE}-unknown-linux-${LIBC}
-        exit ;;
+        GUESS=$UNAME_MACHINE-unknown-linux-$LIBC
+        ;;
     m68*:Linux:*:*)
-        echo ${UNAME_MACHINE}-unknown-linux-${LIBC}
-        exit ;;
+        GUESS=$UNAME_MACHINE-unknown-linux-$LIBC
+        ;;
     mips:Linux:*:* | mips64:Linux:*:*)
-        eval $set_cc_for_build
-        sed 's/^        //' << EOF >$dummy.c
+        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; }
+        cc_set_vars=`$CC_FOR_BUILD -E "$dummy.c" 2>/dev/null | grep '^CPU\|^MIPS_ENDIAN\|^LIBCABI'`
+        eval "$cc_set_vars"
+        test "x$CPU" != x && { echo "$CPU${MIPS_ENDIAN}-unknown-linux-$LIBCABI"; exit; }
+        ;;
+    mips64el:Linux:*:*)
+        GUESS=$UNAME_MACHINE-unknown-linux-$LIBC
         ;;
     openrisc*:Linux:*:*)
-        echo or1k-unknown-linux-${LIBC}
-        exit ;;
+        GUESS=or1k-unknown-linux-$LIBC
+        ;;
     or32:Linux:*:* | or1k*:Linux:*:*)
-        echo ${UNAME_MACHINE}-unknown-linux-${LIBC}
-        exit ;;
+        GUESS=$UNAME_MACHINE-unknown-linux-$LIBC
+        ;;
     padre:Linux:*:*)
-        echo sparc-unknown-linux-${LIBC}
-        exit ;;
+        GUESS=sparc-unknown-linux-$LIBC
+        ;;
     parisc64:Linux:*:* | hppa64:Linux:*:*)
-        echo hppa64-unknown-linux-${LIBC}
-        exit ;;
+        GUESS=hppa64-unknown-linux-$LIBC
+        ;;
     parisc:Linux:*:* | hppa:Linux:*:*)
         # Look for CPU level
         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-${LIBC} ;;
+          PA7*) GUESS=hppa1.1-unknown-linux-$LIBC ;;
+          PA8*) GUESS=hppa2.0-unknown-linux-$LIBC ;;
+          *)    GUESS=hppa-unknown-linux-$LIBC ;;
         esac
-        exit ;;
+        ;;
     ppc64:Linux:*:*)
-        echo powerpc64-unknown-linux-${LIBC}
-        exit ;;
+        GUESS=powerpc64-unknown-linux-$LIBC
+        ;;
     ppc:Linux:*:*)
-        echo powerpc-unknown-linux-${LIBC}
-        exit ;;
+        GUESS=powerpc-unknown-linux-$LIBC
+        ;;
     ppc64le:Linux:*:*)
-        echo powerpc64le-unknown-linux-${LIBC}
-        exit ;;
+        GUESS=powerpc64le-unknown-linux-$LIBC
+        ;;
     ppcle:Linux:*:*)
-        echo powerpcle-unknown-linux-${LIBC}
-        exit ;;
+        GUESS=powerpcle-unknown-linux-$LIBC
+        ;;
+    riscv32:Linux:*:* | riscv32be:Linux:*:* | riscv64:Linux:*:* | riscv64be:Linux:*:*)
+        GUESS=$UNAME_MACHINE-unknown-linux-$LIBC
+        ;;
     s390:Linux:*:* | s390x:Linux:*:*)
-        echo ${UNAME_MACHINE}-ibm-linux-${LIBC}
-        exit ;;
+        GUESS=$UNAME_MACHINE-ibm-linux-$LIBC
+        ;;
     sh64*:Linux:*:*)
-        echo ${UNAME_MACHINE}-unknown-linux-${LIBC}
-        exit ;;
+        GUESS=$UNAME_MACHINE-unknown-linux-$LIBC
+        ;;
     sh*:Linux:*:*)
-        echo ${UNAME_MACHINE}-unknown-linux-${LIBC}
-        exit ;;
+        GUESS=$UNAME_MACHINE-unknown-linux-$LIBC
+        ;;
     sparc:Linux:*:* | sparc64:Linux:*:*)
-        echo ${UNAME_MACHINE}-unknown-linux-${LIBC}
-        exit ;;
+        GUESS=$UNAME_MACHINE-unknown-linux-$LIBC
+        ;;
     tile*:Linux:*:*)
-        echo ${UNAME_MACHINE}-unknown-linux-${LIBC}
-        exit ;;
+        GUESS=$UNAME_MACHINE-unknown-linux-$LIBC
+        ;;
     vax:Linux:*:*)
-        echo ${UNAME_MACHINE}-dec-linux-${LIBC}
-        exit ;;
+        GUESS=$UNAME_MACHINE-dec-linux-$LIBC
+        ;;
     x86_64:Linux:*:*)
-        echo ${UNAME_MACHINE}-pc-linux-${LIBC}
-        exit ;;
+        set_cc_for_build
+        CPU=$UNAME_MACHINE
+        LIBCABI=$LIBC
+        if test "$CC_FOR_BUILD" != no_compiler_found; then
+            ABI=64
+            sed 's/^        //' << EOF > "$dummy.c"
+            #ifdef __i386__
+            ABI=x86
+            #else
+            #ifdef __ILP32__
+            ABI=x32
+            #endif
+            #endif
+EOF
+            cc_set_abi=`$CC_FOR_BUILD -E "$dummy.c" 2>/dev/null | grep '^ABI' | sed 's, ,,g'`
+            eval "$cc_set_abi"
+            case $ABI in
+                x86) CPU=i686 ;;
+                x32) LIBCABI=${LIBC}x32 ;;
+            esac
+        fi
+        GUESS=$CPU-pc-linux-$LIBCABI
+        ;;
     xtensa*:Linux:*:*)
-        echo ${UNAME_MACHINE}-unknown-linux-${LIBC}
-        exit ;;
+        GUESS=$UNAME_MACHINE-unknown-linux-$LIBC
+        ;;
     i*86:DYNIX/ptx:4*:*)
         # ptx 4.0 does uname -s correctly, with DYNIX/ptx in there.
         # earlier versions are messed up and put the nodename in both
         # sysname and nodename.
-        echo i386-sequent-sysv4
-        exit ;;
+        GUESS=i386-sequent-sysv4
+        ;;
     i*86:UNIX_SV:4.2MP:2.*)
         # Unixware is an offshoot of SVR4, but it has its own version
         # number series starting with 2...
         # I am not positive that other SVR4 systems won't match this,
         # I just have to hope.  -- rms.
         # Use sysv4.2uw... so that sysv4* matches it.
-        echo ${UNAME_MACHINE}-pc-sysv4.2uw${UNAME_VERSION}
-        exit ;;
+        GUESS=$UNAME_MACHINE-pc-sysv4.2uw$UNAME_VERSION
+        ;;
     i*86:OS/2:*:*)
         # If we were able to find `uname', then EMX Unix compatibility
         # is probably installed.
-        echo ${UNAME_MACHINE}-pc-os2-emx
-        exit ;;
+        GUESS=$UNAME_MACHINE-pc-os2-emx
+        ;;
     i*86:XTS-300:*:STOP)
-        echo ${UNAME_MACHINE}-unknown-stop
-        exit ;;
+        GUESS=$UNAME_MACHINE-unknown-stop
+        ;;
     i*86:atheos:*:*)
-        echo ${UNAME_MACHINE}-unknown-atheos
-        exit ;;
+        GUESS=$UNAME_MACHINE-unknown-atheos
+        ;;
     i*86:syllable:*:*)
-        echo ${UNAME_MACHINE}-pc-syllable
-        exit ;;
+        GUESS=$UNAME_MACHINE-pc-syllable
+        ;;
     i*86:LynxOS:2.*:* | i*86:LynxOS:3.[01]*:* | i*86:LynxOS:4.[02]*:*)
-        echo i386-unknown-lynxos${UNAME_RELEASE}
-        exit ;;
+        GUESS=i386-unknown-lynxos$UNAME_RELEASE
+        ;;
     i*86:*DOS:*:*)
-        echo ${UNAME_MACHINE}-pc-msdosdjgpp
-        exit ;;
-    i*86:*:4.*:* | i*86:SYSTEM_V:4.*:*)
-        UNAME_REL=`echo ${UNAME_RELEASE} | sed 's/\/MP$//'`
+        GUESS=$UNAME_MACHINE-pc-msdosdjgpp
+        ;;
+    i*86:*:4.*:*)
+        UNAME_REL=`echo "$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}
+                GUESS=$UNAME_MACHINE-univel-sysv$UNAME_REL
         else
-                echo ${UNAME_MACHINE}-pc-sysv${UNAME_REL}
+                GUESS=$UNAME_MACHINE-pc-sysv$UNAME_REL
         fi
-        exit ;;
+        ;;
     i*86:*:5:[678]*)
         # UnixWare 7.x, OpenUNIX and OpenServer 6.
         case `/bin/uname -X | grep "^Machine"` in
@@ -1098,12 +1231,12 @@ EOF
             *Pentium)        UNAME_MACHINE=i586 ;;
             *Pent*|*Celeron) UNAME_MACHINE=i686 ;;
         esac
-        echo ${UNAME_MACHINE}-unknown-sysv${UNAME_RELEASE}${UNAME_SYSTEM}${UNAME_VERSION}
-        exit ;;
+        GUESS=$UNAME_MACHINE-unknown-sysv${UNAME_RELEASE}${UNAME_SYSTEM}${UNAME_VERSION}
+        ;;
     i*86:*:3.2:*)
         if test -f /usr/options/cb.name; then
                 UNAME_REL=`sed -n 's/.*Version //p' </usr/options/cb.name`
-                echo ${UNAME_MACHINE}-pc-isc$UNAME_REL
+                GUESS=$UNAME_MACHINE-pc-isc$UNAME_REL
         elif /bin/uname -X 2>/dev/null >/dev/null ; then
                 UNAME_REL=`(/bin/uname -X|grep Release|sed -e 's/.*= //')`
                 (/bin/uname -X|grep i80486 >/dev/null) && UNAME_MACHINE=i486
@@ -1113,11 +1246,11 @@ EOF
                         && UNAME_MACHINE=i686
                 (/bin/uname -X|grep '^Machine.*Pentium Pro' >/dev/null) \
                         && UNAME_MACHINE=i686
-                echo ${UNAME_MACHINE}-pc-sco$UNAME_REL
+                GUESS=$UNAME_MACHINE-pc-sco$UNAME_REL
         else
-                echo ${UNAME_MACHINE}-pc-sysv32
+                GUESS=$UNAME_MACHINE-pc-sysv32
         fi
-        exit ;;
+        ;;
     pc:*:*:*)
         # Left here for compatibility:
         # uname -m prints for DJGPP always 'pc', but it prints nothing about
@@ -1125,31 +1258,31 @@ EOF
         # Note: whatever this is, it MUST be the same as what config.sub
         # prints for the "djgpp" host, or else GDB configure will decide that
         # this is a cross-build.
-        echo i586-pc-msdosdjgpp
-        exit ;;
+        GUESS=i586-pc-msdosdjgpp
+        ;;
     Intel:Mach:3*:*)
-        echo i386-pc-mach3
-        exit ;;
+        GUESS=i386-pc-mach3
+        ;;
     paragon:*:*:*)
-        echo i860-intel-osf1
-        exit ;;
+        GUESS=i860-intel-osf1
+        ;;
     i860:*:4.*:*) # i860-SVR4
         if grep Stardent /usr/include/sys/uadmin.h >/dev/null 2>&1 ; then
-          echo i860-stardent-sysv${UNAME_RELEASE} # Stardent Vistra i860-SVR4
+          GUESS=i860-stardent-sysv$UNAME_RELEASE    # Stardent Vistra i860-SVR4
         else # Add other i860-SVR4 vendors below as they are discovered.
-          echo i860-unknown-sysv${UNAME_RELEASE}  # Unknown i860-SVR4
+          GUESS=i860-unknown-sysv$UNAME_RELEASE     # Unknown i860-SVR4
         fi
-        exit ;;
+        ;;
     mini*:CTIX:SYS*5:*)
         # "miniframe"
-        echo m68010-convergent-sysv
-        exit ;;
+        GUESS=m68010-convergent-sysv
+        ;;
     mc68k:UNIX:SYSTEM5:3.51m)
-        echo m68k-convergent-sysv
-        exit ;;
+        GUESS=m68k-convergent-sysv
+        ;;
     M680?0:D-NIX:5.3:*)
-        echo m68k-diab-dnix
-        exit ;;
+        GUESS=m68k-diab-dnix
+        ;;
     M68*:*:R3V[5678]*:*)
         test -r /sysV68 && { echo 'm68k-motorola-sysv'; exit; } ;;
     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)
@@ -1157,9 +1290,9 @@ EOF
         test -r /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${OS_REL}; exit; }
+          && { echo i486-ncr-sysv4.3"$OS_REL"; exit; }
         /bin/uname -p 2>/dev/null | /bin/grep entium >/dev/null \
-          && { echo i586-ncr-sysv4.3${OS_REL}; exit; } ;;
+          && { echo i586-ncr-sysv4.3"$OS_REL"; exit; } ;;
     3[34]??:*:4.0:* | 3[34]??,*:*:4.0:*)
         /bin/uname -p 2>/dev/null | grep 86 >/dev/null \
           && { echo i486-ncr-sysv4; exit; } ;;
@@ -1168,251 +1301,444 @@ EOF
         test -r /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${OS_REL}; exit; }
+            && { echo i486-ncr-sysv4.3"$OS_REL"; exit; }
         /bin/uname -p 2>/dev/null | /bin/grep entium >/dev/null \
-            && { echo i586-ncr-sysv4.3${OS_REL}; exit; }
+            && { echo i586-ncr-sysv4.3"$OS_REL"; exit; }
         /bin/uname -p 2>/dev/null | /bin/grep pteron >/dev/null \
-            && { echo i586-ncr-sysv4.3${OS_REL}; exit; } ;;
+            && { echo i586-ncr-sysv4.3"$OS_REL"; exit; } ;;
     m68*:LynxOS:2.*:* | m68*:LynxOS:3.0*:*)
-        echo m68k-unknown-lynxos${UNAME_RELEASE}
-        exit ;;
+        GUESS=m68k-unknown-lynxos$UNAME_RELEASE
+        ;;
     mc68030:UNIX_System_V:4.*:*)
-        echo m68k-atari-sysv4
-        exit ;;
+        GUESS=m68k-atari-sysv4
+        ;;
     TSUNAMI:LynxOS:2.*:*)
-        echo sparc-unknown-lynxos${UNAME_RELEASE}
-        exit ;;
+        GUESS=sparc-unknown-lynxos$UNAME_RELEASE
+        ;;
     rs6000:LynxOS:2.*:*)
-        echo rs6000-unknown-lynxos${UNAME_RELEASE}
-        exit ;;
+        GUESS=rs6000-unknown-lynxos$UNAME_RELEASE
+        ;;
     PowerPC:LynxOS:2.*:* | PowerPC:LynxOS:3.[01]*:* | PowerPC:LynxOS:4.[02]*:*)
-        echo powerpc-unknown-lynxos${UNAME_RELEASE}
-        exit ;;
+        GUESS=powerpc-unknown-lynxos$UNAME_RELEASE
+        ;;
     SM[BE]S:UNIX_SV:*:*)
-        echo mips-dde-sysv${UNAME_RELEASE}
-        exit ;;
+        GUESS=mips-dde-sysv$UNAME_RELEASE
+        ;;
     RM*:ReliantUNIX-*:*:*)
-        echo mips-sni-sysv4
-        exit ;;
+        GUESS=mips-sni-sysv4
+        ;;
     RM*:SINIX-*:*:*)
-        echo mips-sni-sysv4
-        exit ;;
+        GUESS=mips-sni-sysv4
+        ;;
     *:SINIX-*:*:*)
         if uname -p 2>/dev/null >/dev/null ; then
                 UNAME_MACHINE=`(uname -p) 2>/dev/null`
-                echo ${UNAME_MACHINE}-sni-sysv4
+                GUESS=$UNAME_MACHINE-sni-sysv4
         else
-                echo ns32k-sni-sysv
+                GUESS=ns32k-sni-sysv
         fi
-        exit ;;
+        ;;
     PENTIUM:*:4.0*:*)   # Unisys `ClearPath HMP IX 4000' SVR4/MP effort
                         # says <Richard.M.Bartel@ccMail.Census.GOV>
-        echo i586-unisys-sysv4
-        exit ;;
+        GUESS=i586-unisys-sysv4
+        ;;
     *:UNIX_System_V:4*:FTX*)
         # From Gerald Hewes <hewes@openmarket.com>.
         # How about differentiating between stratus architectures? -djm
-        echo hppa1.1-stratus-sysv4
-        exit ;;
+        GUESS=hppa1.1-stratus-sysv4
+        ;;
     *:*:*:FTX*)
         # From seanf@swdc.stratus.com.
-        echo i860-stratus-sysv4
-        exit ;;
+        GUESS=i860-stratus-sysv4
+        ;;
     i*86:VOS:*:*)
         # From Paul.Green@stratus.com.
-        echo ${UNAME_MACHINE}-stratus-vos
-        exit ;;
+        GUESS=$UNAME_MACHINE-stratus-vos
+        ;;
     *:VOS:*:*)
         # From Paul.Green@stratus.com.
-        echo hppa1.1-stratus-vos
-        exit ;;
+        GUESS=hppa1.1-stratus-vos
+        ;;
     mc68*:A/UX:*:*)
-        echo m68k-apple-aux${UNAME_RELEASE}
-        exit ;;
+        GUESS=m68k-apple-aux$UNAME_RELEASE
+        ;;
     news*:NEWS-OS:6*:*)
-        echo mips-sony-newsos6
-        exit ;;
+        GUESS=mips-sony-newsos6
+        ;;
     R[34]000:*System_V*:*:* | R4000:UNIX_SYSV:*:* | R*000:UNIX_SV:*:*)
-        if [ -d /usr/nec ]; then
-                echo mips-nec-sysv${UNAME_RELEASE}
+        if test -d /usr/nec; then
+                GUESS=mips-nec-sysv$UNAME_RELEASE
         else
-                echo mips-unknown-sysv${UNAME_RELEASE}
+                GUESS=mips-unknown-sysv$UNAME_RELEASE
         fi
-        exit ;;
+        ;;
     BeBox:BeOS:*:*)     # BeOS running on hardware made by Be, PPC only.
-        echo powerpc-be-beos
-        exit ;;
+        GUESS=powerpc-be-beos
+        ;;
     BeMac:BeOS:*:*)     # BeOS running on Mac or Mac clone, PPC only.
-        echo powerpc-apple-beos
-        exit ;;
+        GUESS=powerpc-apple-beos
+        ;;
     BePC:BeOS:*:*)      # BeOS running on Intel PC compatible.
-        echo i586-pc-beos
-        exit ;;
+        GUESS=i586-pc-beos
+        ;;
     BePC:Haiku:*:*)     # Haiku running on Intel PC compatible.
-        echo i586-pc-haiku
-        exit ;;
-    x86_64:Haiku:*:*)
-        echo x86_64-unknown-haiku
-        exit ;;
+        GUESS=i586-pc-haiku
+        ;;
+    ppc:Haiku:*:*)      # Haiku running on Apple PowerPC
+        GUESS=powerpc-apple-haiku
+        ;;
+    *:Haiku:*:*)        # Haiku modern gcc (not bound by BeOS compat)
+        GUESS=$UNAME_MACHINE-unknown-haiku
+        ;;
     SX-4:SUPER-UX:*:*)
-        echo sx4-nec-superux${UNAME_RELEASE}
-        exit ;;
+        GUESS=sx4-nec-superux$UNAME_RELEASE
+        ;;
     SX-5:SUPER-UX:*:*)
-        echo sx5-nec-superux${UNAME_RELEASE}
-        exit ;;
+        GUESS=sx5-nec-superux$UNAME_RELEASE
+        ;;
     SX-6:SUPER-UX:*:*)
-        echo sx6-nec-superux${UNAME_RELEASE}
-        exit ;;
+        GUESS=sx6-nec-superux$UNAME_RELEASE
+        ;;
     SX-7:SUPER-UX:*:*)
-        echo sx7-nec-superux${UNAME_RELEASE}
-        exit ;;
+        GUESS=sx7-nec-superux$UNAME_RELEASE
+        ;;
     SX-8:SUPER-UX:*:*)
-        echo sx8-nec-superux${UNAME_RELEASE}
-        exit ;;
+        GUESS=sx8-nec-superux$UNAME_RELEASE
+        ;;
     SX-8R:SUPER-UX:*:*)
-        echo sx8r-nec-superux${UNAME_RELEASE}
-        exit ;;
+        GUESS=sx8r-nec-superux$UNAME_RELEASE
+        ;;
+    SX-ACE:SUPER-UX:*:*)
+        GUESS=sxace-nec-superux$UNAME_RELEASE
+        ;;
     Power*:Rhapsody:*:*)
-        echo powerpc-apple-rhapsody${UNAME_RELEASE}
-        exit ;;
+        GUESS=powerpc-apple-rhapsody$UNAME_RELEASE
+        ;;
     *:Rhapsody:*:*)
-        echo ${UNAME_MACHINE}-apple-rhapsody${UNAME_RELEASE}
-        exit ;;
+        GUESS=$UNAME_MACHINE-apple-rhapsody$UNAME_RELEASE
+        ;;
+    arm64:Darwin:*:*)
+        GUESS=aarch64-apple-darwin$UNAME_RELEASE
+        ;;
     *:Darwin:*:*)
-        UNAME_PROCESSOR=`uname -p` || UNAME_PROCESSOR=unknown
-        eval $set_cc_for_build
-        if test "$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 $UNAME_PROCESSOR in
-                        i386) UNAME_PROCESSOR=x86_64 ;;
-                        powerpc) UNAME_PROCESSOR=powerpc64 ;;
-                    esac
-                fi
+        if test "$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 ;;
+        GUESS=$UNAME_PROCESSOR-apple-darwin$UNAME_RELEASE
+        ;;
     *:procnto*:*:* | *:QNX:[0123456789]*:*)
         UNAME_PROCESSOR=`uname -p`
-        if test "$UNAME_PROCESSOR" = "x86"; then
+        if test "$UNAME_PROCESSOR" = x86; then
                 UNAME_PROCESSOR=i386
                 UNAME_MACHINE=pc
         fi
-        echo ${UNAME_PROCESSOR}-${UNAME_MACHINE}-nto-qnx${UNAME_RELEASE}
-        exit ;;
+        GUESS=$UNAME_PROCESSOR-$UNAME_MACHINE-nto-qnx$UNAME_RELEASE
+        ;;
     *:QNX:*:4*)
-        echo i386-pc-qnx
-        exit ;;
-    NEO-?:NONSTOP_KERNEL:*:*)
-        echo neo-tandem-nsk${UNAME_RELEASE}
-        exit ;;
+        GUESS=i386-pc-qnx
+        ;;
+    NEO-*:NONSTOP_KERNEL:*:*)
+        GUESS=neo-tandem-nsk$UNAME_RELEASE
+        ;;
     NSE-*:NONSTOP_KERNEL:*:*)
-        echo nse-tandem-nsk${UNAME_RELEASE}
-        exit ;;
-    NSR-?:NONSTOP_KERNEL:*:*)
-        echo nsr-tandem-nsk${UNAME_RELEASE}
-        exit ;;
+        GUESS=nse-tandem-nsk$UNAME_RELEASE
+        ;;
+    NSR-*:NONSTOP_KERNEL:*:*)
+        GUESS=nsr-tandem-nsk$UNAME_RELEASE
+        ;;
+    NSV-*:NONSTOP_KERNEL:*:*)
+        GUESS=nsv-tandem-nsk$UNAME_RELEASE
+        ;;
+    NSX-*:NONSTOP_KERNEL:*:*)
+        GUESS=nsx-tandem-nsk$UNAME_RELEASE
+        ;;
     *:NonStop-UX:*:*)
-        echo mips-compaq-nonstopux
-        exit ;;
+        GUESS=mips-compaq-nonstopux
+        ;;
     BS2000:POSIX*:*:*)
-        echo bs2000-siemens-sysv
-        exit ;;
+        GUESS=bs2000-siemens-sysv
+        ;;
     DS/*:UNIX_System_V:*:*)
-        echo ${UNAME_MACHINE}-${UNAME_SYSTEM}-${UNAME_RELEASE}
-        exit ;;
+        GUESS=$UNAME_MACHINE-$UNAME_SYSTEM-$UNAME_RELEASE
+        ;;
     *:Plan9:*:*)
         # "uname -m" is not consistent, so use $cputype instead. 386
         # is converted to i386 for consistency with other x86
         # operating systems.
-        if test "$cputype" = "386"; then
+        if test "${cputype-}" = 386; then
             UNAME_MACHINE=i386
-        else
-            UNAME_MACHINE="$cputype"
+        elif test "x${cputype-}" != x; then
+            UNAME_MACHINE=$cputype
         fi
-        echo ${UNAME_MACHINE}-unknown-plan9
-        exit ;;
+        GUESS=$UNAME_MACHINE-unknown-plan9
+        ;;
     *:TOPS-10:*:*)
-        echo pdp10-unknown-tops10
-        exit ;;
+        GUESS=pdp10-unknown-tops10
+        ;;
     *:TENEX:*:*)
-        echo pdp10-unknown-tenex
-        exit ;;
+        GUESS=pdp10-unknown-tenex
+        ;;
     KS10:TOPS-20:*:* | KL10:TOPS-20:*:* | TYPE4:TOPS-20:*:*)
-        echo pdp10-dec-tops20
-        exit ;;
+        GUESS=pdp10-dec-tops20
+        ;;
     XKL-1:TOPS-20:*:* | TYPE5:TOPS-20:*:*)
-        echo pdp10-xkl-tops20
-        exit ;;
+        GUESS=pdp10-xkl-tops20
+        ;;
     *:TOPS-20:*:*)
-        echo pdp10-unknown-tops20
-        exit ;;
+        GUESS=pdp10-unknown-tops20
+        ;;
     *:ITS:*:*)
-        echo pdp10-unknown-its
-        exit ;;
+        GUESS=pdp10-unknown-its
+        ;;
     SEI:*:*:SEIUX)
-        echo mips-sei-seiux${UNAME_RELEASE}
-        exit ;;
+        GUESS=mips-sei-seiux$UNAME_RELEASE
+        ;;
     *:DragonFly:*:*)
-        echo ${UNAME_MACHINE}-unknown-dragonfly`echo ${UNAME_RELEASE}|sed -e 's/[-(].*//'`
-        exit ;;
+        DRAGONFLY_REL=`echo "$UNAME_RELEASE" | sed -e 's/[-(].*//'`
+        GUESS=$UNAME_MACHINE-unknown-dragonfly$DRAGONFLY_REL
+        ;;
     *:*VMS:*:*)
         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 ;;
+        case $UNAME_MACHINE in
+            A*) GUESS=alpha-dec-vms ;;
+            I*) GUESS=ia64-dec-vms ;;
+            V*) GUESS=vax-dec-vms ;;
         esac ;;
     *:XENIX:*:SysV)
-        echo i386-pc-xenix
-        exit ;;
+        GUESS=i386-pc-xenix
+        ;;
     i*86:skyos:*:*)
-        echo ${UNAME_MACHINE}-pc-skyos`echo ${UNAME_RELEASE}` | sed -e 's/ .*$//'
-        exit ;;
+        SKYOS_REL=`echo "$UNAME_RELEASE" | sed -e 's/ .*$//'`
+        GUESS=$UNAME_MACHINE-pc-skyos$SKYOS_REL
+        ;;
     i*86:rdos:*:*)
-        echo ${UNAME_MACHINE}-pc-rdos
-        exit ;;
-    i*86:AROS:*:*)
-        echo ${UNAME_MACHINE}-pc-aros
-        exit ;;
+        GUESS=$UNAME_MACHINE-pc-rdos
+        ;;
+    i*86:Fiwix:*:*)
+        GUESS=$UNAME_MACHINE-pc-fiwix
+        ;;
+    *:AROS:*:*)
+        GUESS=$UNAME_MACHINE-unknown-aros
+        ;;
     x86_64:VMkernel:*:*)
-        echo ${UNAME_MACHINE}-unknown-esx
-        exit ;;
+        GUESS=$UNAME_MACHINE-unknown-esx
+        ;;
     amd64:Isilon\ OneFS:*:*)
-        echo x86_64-unknown-onefs
-        exit ;;
+        GUESS=x86_64-unknown-onefs
+        ;;
+    *:Unleashed:*:*)
+        GUESS=$UNAME_MACHINE-unknown-unleashed$UNAME_RELEASE
+        ;;
+esac
+
+# Do we have a guess based on uname results?
+if test "x$GUESS" != x; then
+    echo "$GUESS"
+    exit
+fi
+
+# 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
+    mips:Linux | mips64:Linux)
+        # If we got here on MIPS GNU/Linux, output extra information.
+        cat >&2 <<EOF
+
+NOTE: MIPS GNU/Linux systems require a C compiler to fully recognize
+the system type. Please install a C compiler and try again.
+EOF
+        ;;
 esac
 
 cat >&2 <<EOF
-$0: unable to guess system type
 
-This script, last modified $timestamp, has failed to recognize
-the operating system you are using. It is advised that you
-download the most up to date version of the config scripts from
+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:
 
-  http://git.savannah.gnu.org/gitweb/?p=config.git;a=blob_plain;f=config.guess;hb=HEAD
+  https://git.savannah.gnu.org/cgit/config.git/plain/config.guess
 and
-  http://git.savannah.gnu.org/gitweb/?p=config.git;a=blob_plain;f=config.sub;hb=HEAD
+  https://git.savannah.gnu.org/cgit/config.git/plain/config.sub
+EOF
 
-If the version you run ($0) is already up to date, please
-send the following data and any information you think might be
-pertinent to <config-patches@gnu.org> in order to provide the needed
-information to handle your system.
+our_year=`echo $timestamp | sed 's,-.*,,'`
+thisyear=`date +%Y`
+# shellcheck disable=SC2003
+script_age=`expr "$thisyear" - "$our_year"`
+if test "$script_age" -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
+provide the necessary information to handle your system.
 
 config.guess timestamp = $timestamp
 
@@ -1431,16 +1757,17 @@ hostinfo               = `(hostinfo) 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 = ${UNAME_VERSION}
+UNAME_MACHINE = "$UNAME_MACHINE"
+UNAME_RELEASE = "$UNAME_RELEASE"
+UNAME_SYSTEM  = "$UNAME_SYSTEM"
+UNAME_VERSION = "$UNAME_VERSION"
 EOF
+fi
 
 exit 1
 
 # Local variables:
-# eval: (add-hook 'write-file-hooks 'time-stamp)
+# eval: (add-hook 'before-save-hook 'time-stamp)
 # time-stamp-start: "timestamp='"
 # time-stamp-format: "%:y-%02m-%02d"
 # time-stamp-end: "'"