private int regionToDot(Region r, StringBuilder str, Map<Region, Integer> cache) {
if (cache.containsKey(r)) { // use same region again
return cache.get(r);
} else {
Triple<Region, Region, Region> triple = delegate.getIfThenElse(r);
// create node with label
String predName = regionMap.inverse().get(triple.getFirst());
nodeCounter += 1; // one more node is created
int predNum = nodeCounter;
str.append(predNum).append(" [label=\"").append(predName).append("\"];\n");
// create arrow for true branch
Region trueBranch = triple.getSecond();
int trueTarget = regionToDot(trueBranch, str, cache);
str.append(predNum).append(" -> ").append(trueTarget).append(" [style=filled];\n");
// create arrow for false branch
Region falseBranch = triple.getThird();
int falseTarget = regionToDot(falseBranch, str, cache);
str.append(predNum).append(" -> ").append(falseTarget).append(" [style=dotted];\n");
cache.put(r, predNum);
return predNum;
}
}
private void dumpRegion(Region r, Appendable out) throws IOException {
if (regionMap.containsValue(r)) {
out.append(regionMap.inverse().get(r));
} else if (r.isFalse()) {
out.append("FALSE");
} else if (r.isTrue()) {
out.append("TRUE");
} else {
Triple<Region, Region, Region> triple = delegate.getIfThenElse(r);
String predName = regionMap.inverse().get(triple.getFirst());
Region trueBranch = triple.getSecond();
Region falseBranch = triple.getThird();
if (trueBranch.isFalse()) {
assert !falseBranch.isFalse();
// only falseBranch is present
out.append("!").append(predName).append(" & ");
dumpRegion(falseBranch, out);
} else if (falseBranch.isFalse()) {
// only trueBranch is present
out.append(predName).append(" & ");
dumpRegion(trueBranch, out);
} else {
// both branches present
out.append("((").append(predName).append(" & ");
dumpRegion(trueBranch, out);
out.append(") | (").append("!").append(predName).append(" & ");
dumpRegion(falseBranch, out);
out.append("))");
}
}
}
@Override
public Object getHashCodeForState(AbstractState pElementKey, Precision pPrecisionKey) {
PredicateAbstractState element = (PredicateAbstractState) pElementKey;
PredicatePrecision precision = (PredicatePrecision) pPrecisionKey;
/*
Normally a getHashCodeForState is just the pair of state and precision.
For PredicateAnalysis, we need to refine the RelevantPredicatesComputer (in some cases),
thus the reduce-operator changes and we should clear the cache completely after such a refinement.
Instead of doing this, we use the RelevantPredicatesComputer as (third) part of the cache-key,
such that after refining the RelevantPredicatesComputer, each new access results in a cache-miss.
The benefit is that we keep existing ARGs for statistics or other usage.
The drawback is the memory-usage through some cached states,
that will never be visited again, because the reduce-operator has changed.
*/
// TODO is Object-equality for RelevantPredicatesComputer enough or should we implement
// RelevantPredicatesComputer.equals()?
return Triple.of(
element.getAbstractionFormula().asRegion(), precision, cpa.getRelevantPredicatesComputer());
}