doc/script/gen_state_diagram: only run if called as a script

Signed-off-by: Kefu Chai <kchai@redhat.com>

diff --git a/doc/scripts/gen_state_diagram.py b/doc/scripts/gen_state_diagram.py
index 868eaa287d3b41183db9f38f07b76bfb71079c9f..2054bfb1f09d5400437ce0b576dae47542d58eee 100755 (executable)
--- a/doc/scripts/gen_state_diagram.py
+++ b/doc/scripts/gen_state_diagram.py
@@ -235,7 +235,8 @@ class StateMachineRenderer(object):
             yield("%s -> %s %s;" % (fro, to, append(appendix)))
 
 
-INPUT_GENERATOR = do_filter(line for line in sys.stdin)
-RENDERER = StateMachineRenderer()
-RENDERER.read_input(INPUT_GENERATOR)
-RENDERER.emit_dot()
+if __name__ == '__main__':
+    INPUT_GENERATOR = do_filter(line for line in sys.stdin)
+    RENDERER = StateMachineRenderer()
+    RENDERER.read_input(INPUT_GENERATOR)
+    RENDERER.emit_dot()