import python
import semmle.python.dataflow.new.DataFlow
private import semmle.python.dataflow.new.internal.DataFlowPrivate as DataFlowPrivate

/**
 * A configuration to find all "maximal" flows.
 * To be used on small programs.
 */
module MaximalFlowsConfig implements DataFlow::ConfigSig {
  predicate isSource(DataFlow::Node node) {
    node instanceof DataFlow::ParameterNode
    or
    node instanceof DataFlow::LocalSourceNode
  }

  predicate isSink(DataFlow::Node node) {
    node instanceof DataFlowPrivate::ReturnNode
    or
    not DataFlowPrivate::LocalFlow::localFlowStep(node, _)
  }
}

module MaximalFlowsFlow = DataFlow::Global<MaximalFlowsConfig>;