+#########################################
+## Build optional modules (gtnets)
+##
+
+# Check whether --with-gtnets was given.
+if test "${with_gtnets+set}" = set; then
+ withval=$with_gtnets; gtnets_path="$withval"
+else
+ gtnets_path="NO"
+fi
+
+if test "x$gtnets_path" = "xNO" ; then
+ { echo "$as_me:$LINENO: result: Eventually you will come to GTNetS. $gtnets_path" >&5
+echo "${ECHO_T}Eventually you will come to GTNetS. $gtnets_path" >&6; }
+else
+ { echo "$as_me:$LINENO: result: ***** You have decided to use the experimental GTNetS. We hope you know what you're doing.. ****" >&5
+echo "${ECHO_T}***** You have decided to use the experimental GTNetS. We hope you know what you're doing.. ****" >&6; }
+
+cat >>confdefs.h <<\_ACEOF
+#define USE_GTNETS 1
+_ACEOF
+
+ if ! test -e $gtnets_path ; then
+ { { echo "$as_me:$LINENO: error: Provided path to GTNetS include files ($gtnets_path) do not exist!" >&5
+echo "$as_me: error: Provided path to GTNetS include files ($gtnets_path) do not exist!" >&2;}
+ { (exit 1); exit 1; }; }
+ fi
+ GTNETS_CFLAGS=-I$gtnets_path/include
+
+ GTNETS_LDFLAGS=-L$gtnets_path/lib
+
+fi
+
+
+if test "x$gtnets_path" != xNO; then
+ USE_GTNETS_TRUE=
+ USE_GTNETS_FALSE='#'
+else
+ USE_GTNETS_TRUE='#'
+ USE_GTNETS_FALSE=
+fi
+
+