/**
* Clear deref sets of values if this edge is the non-null branch of an if comparison.
*
* @param fact a datflow fact
* @param edge edge to check
* @return possibly-modified dataflow fact
*/
private @CheckForNull ValueNumber findValueKnownNonnullOnBranch(
UnconditionalValueDerefSet fact, Edge edge) {
IsNullValueFrame invFrame = invDataflow.getResultFact(edge.getSource());
if (!invFrame.isValid()) {
return null;
}
IsNullConditionDecision decision = invFrame.getDecision();
if (decision == null) {
return null;
}
IsNullValue inv = decision.getDecision(edge.getType());
if (inv == null || !inv.isDefinitelyNotNull()) {
return null;
}
ValueNumber value = decision.getValue();
if (DEBUG) {
System.out.println("Value number " + value + " is known nonnull on " + edge);
}
return value;
}
