+# vswitch E-R diagram
+#
+# There are two complications here. First, if "python" or "dot" is not
+# available, then we have to just use the existing diagram. Second, different
+# "dot" versions produce slightly different output for the same input, but we
+# don't want to gratuitously change vswitch.pic if someone tweaks the schema in
+# some minor way that doesn't affect the table structure. To avoid that we
+# store a checksum of vswitch.gv in vswitch.pic and only regenerate vswitch.pic
+# if vswitch.gv actually changes.
+$(srcdir)/vswitchd/vswitch.gv: ovsdb/ovsdb-dot.in vswitchd/vswitch.ovsschema
+if HAVE_PYTHON
+ $(OVSDB_DOT) $(srcdir)/vswitchd/vswitch.ovsschema > $@
+else
+ touch $@
+endif
+$(srcdir)/vswitchd/vswitch.pic: $(srcdir)/vswitchd/vswitch.gv ovsdb/dot2pic
+if HAVE_DOT
+ sum=`cksum < $(srcdir)/vswitchd/vswitch.gv`; \
+ if grep "$$sum" $@ >/dev/null 2>&1; then \
+ echo "vswitch.gv unchanged, not regenerating vswitch.pic"; \
+ touch $@; \
+ else \
+ echo "regenerating vswitch.pic"; \
+ (echo ".\\\" Generated from vswitch.gv with cksum \"$$sum\""; \
+ dot -T plain < $(srcdir)/vswitchd/vswitch.gv \
+ | $(srcdir)/ovsdb/dot2pic) > $@; \
+ fi
+else
+ touch $@
+endif
+EXTRA_DIST += vswitchd/vswitch.gv vswitchd/vswitch.pic
+