/**
* The confluence operator is essentially the union of all of the inItems. However, if two or more
* of the initCount maps from the inItems each have a MinMaxInitCounts entry for the same
* VarInstance, the conflict must be resolved, by using the minimum of all mins and the maximum of
* all maxs.
*/
public Item confluence(List inItems, Term node, FlowGraph graph) {
// Resolve any conflicts pairwise.
Iterator iter = inItems.iterator();
Map m = null;
while (iter.hasNext()) {
Item itm = (Item) iter.next();
if (itm == BOTTOM) continue;
if (m == null) {
m = new HashMap(((DataFlowItem) itm).initStatus);
} else {
Map n = ((DataFlowItem) itm).initStatus;
for (Iterator iter2 = n.entrySet().iterator(); iter2.hasNext(); ) {
Map.Entry entry = (Map.Entry) iter2.next();
VarInstance v = (VarInstance) entry.getKey();
MinMaxInitCount initCount1 = (MinMaxInitCount) m.get(v);
MinMaxInitCount initCount2 = (MinMaxInitCount) entry.getValue();
m.put(v, MinMaxInitCount.join(initCount1, initCount2));
}
}
}
if (m == null) return BOTTOM;
return new DataFlowItem(m);
}
/**
* Check that each static final field is initialized exactly once.
*
* @param cb The ClassBody of the class declaring the fields to check.
* @throws SemanticException
*/
protected void checkStaticFinalFieldsInit(ClassBody cb) throws SemanticException {
// check that all static fields have been initialized exactly once.
for (Iterator iter = currCBI.currClassFinalFieldInitCounts.entrySet().iterator();
iter.hasNext(); ) {
Map.Entry e = (Map.Entry) iter.next();
if (e.getKey() instanceof FieldInstance) {
FieldInstance fi = (FieldInstance) e.getKey();
if (fi.flags().isStatic() && fi.flags().isFinal()) {
MinMaxInitCount initCount = (MinMaxInitCount) e.getValue();
if (InitCount.ZERO.equals(initCount.getMin())) {
throw new SemanticException(
"field \"" + fi.name() + "\" might not have been initialized", cb.position());
}
}
}
}
}
/** Perform necessary actions upon seeing the Initializer <code>initializer</code>. */
protected void finishInitializer(
FlowGraph graph, Initializer initializer, DataFlowItem dfIn, DataFlowItem dfOut) {
// We are finishing the checking of an intializer.
// We need to copy back the init counts of any fields back into
// currClassFinalFieldInitCounts, so that the counts are
// correct for the next initializer or constructor.
Iterator iter = dfOut.initStatus.entrySet().iterator();
while (iter.hasNext()) {
Map.Entry e = (Map.Entry) iter.next();
if (e.getKey() instanceof FieldInstance) {
FieldInstance fi = (FieldInstance) e.getKey();
if (fi.flags().isFinal()) {
// we don't need to join the init counts, as all
// dataflows will go through all of the
// initializers
currCBI.currClassFinalFieldInitCounts.put(fi, e.getValue());
}
}
}
}