update config.guess

ext/config.guess

@@ -1,8 +1,8 @@
 #! /bin/sh
 # Attempt to guess a canonical system name.
-#   Copyright 1992-2019 Free Software Foundation, Inc.
+#   Copyright 1992-2020 Free Software Foundation, Inc.
 
-timestamp='2019-09-10'
+timestamp='2020-04-26'
 
 # 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
@@ -50,7 +50,7 @@ version="\
 GNU config.guess ($timestamp)
 
 Originally written by Per Bothner.
-Copyright 1992-2019 Free Software Foundation, Inc.
+Copyright 1992-2020 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."
@@ -99,6 +99,8 @@ tmp=
 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" ; } ||
@@ -924,7 +926,7 @@ 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 ;;
@@ -1627,6 +1629,12 @@ 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
 and
   https://git.savannah.gnu.org/gitweb/?p=config.git;a=blob_plain;f=config.sub
+EOF
+
+year=`echo $timestamp | sed 's,-.*,,'`
+# shellcheck disable=SC2003
+if test "`expr "\`date +%Y\`" - "$year"`" -lt 3 ; then
+   cat >&2 <<EOF
 
 If $0 has already been updated, send the following data and any
 information you think might be pertinent to config-patches@gnu.org to
@@ -1654,6 +1662,7 @@ UNAME_RELEASE = "$UNAME_RELEASE"
 UNAME_SYSTEM  = "$UNAME_SYSTEM"
 UNAME_VERSION = "$UNAME_VERSION"
 EOF
+fi
 
 exit 1