1 files changed, 82 insertions, 0 deletions
diff --git a/BuildTools/bin/find_m4.sh b/BuildTools/bin/find_m4.sh
new file mode 100755
index 0000000..632e86f
--- /dev/null
+++ b/BuildTools/bin/find_m4.sh
@@ -0,0 +1,82 @@
+#!/bin/sh
+
+# Copyright (c) 1998 Sendmail, Inc.  All rights reserved.
+#
+# By using this file, you agree to the terms and conditions set
+# forth in the LICENSE file which can be found at the top level of
+# the sendmail distribution.
+#
+#
+#       @(#)find_m4.sh	8.4 (Berkeley) 5/19/1998
+#
+
+# Try to find a working M4 program.
+# If $M4 is already set, we use it, otherwise we prefer GNU m4.
+
+EX_UNAVAILABLE=69
+
+test="ifdef(\`pushdef', \`',
+\`errprint(\`You need a newer version of M4, at least as new as System V or GNU')
+include(NoSuchFile)')
+define(\`BadNumber', \`10')
+ifdef(\`BadNumber', \`', \`errprint(\`This version of m4 is broken')')"
+
+if [ "$M4" ]
+then
+	err=`(echo "$test" | $M4) 2>&1 >/dev/null`
+	code=$?
+else
+	firstfound=
+	ifs="$IFS"; IFS="${IFS}:"
+	for m4 in gm4 gnum4 pdm4 m4
+	do
+		for dir in $PATH /usr/5bin /usr/ccs/bin
+		do
+			[ -z "$dir" ] && dir=.
+			if [ -f $dir/$m4 ]
+			then
+				err=`(echo "$test" | $dir/$m4) 2>&1 >/dev/null`
+				ret=$?
+				if [ $ret -eq 0 -a "X$err" = "X" ]
+				then
+					M4=$dir/$m4
+					code=0
+					break
+				else
+					case "$firstfound:$err" in
+					  :*version\ of*)
+						firstfound=$dir/$m4
+						firsterr="$err"
+						firstcode=$ret
+						;;
+					esac
+				fi
+			fi
+		done
+		[ "$M4" ] && break
+	done
+	IFS="$ifs"
+	if [ ! "$M4" ]
+	then
+		if [ "$firstfound" ]
+		then
+			M4=$firstfound
+			err="$firsterr"
+			code=$firstcode
+		else
+			echo "ERROR: Can not locate an M4 program" >&2
+			exit $EX_UNAVAILABLE
+		fi
+	fi
+fi
+if [ $code -ne 0 ]
+then
+	echo "ERROR: Using M4=$M4: $err" | grep -v NoSuchFile >&2
+	exit $EX_UNAVAILABLE
+elif [ "X$err" != "X" ]
+then
+	echo "WARNING: $err" >&2
+fi
+echo $M4
+exit 0
+