/**
* Check that the conditions of initialization are not broken.
*
* <p>To summarize the conditions: - Local variables must be initialized before use, (i.e. min
* count > 0) - Final local variables (including Formals) cannot be assigned to more than once
* (i.e. max count <= 1) - Final non-static fields whose target is this cannot be assigned to more
* than once - Final static fields whose target is the current class cannot be assigned to more
* than once
*
* <p>This method is also responsible for maintaining state between the dataflows over
* Initializers, by copying back the appropriate MinMaxInitCounts to the map
* currClassFinalFieldInitCounts.
*/
public void check(FlowGraph graph, Term n, Item inItem, Map outItems) throws SemanticException {
DataFlowItem dfIn = (DataFlowItem) inItem;
if (dfIn == null) {
// There is no input data flow item. This can happen if we are
// checking an unreachable term, and so no Items have flowed
// through the term. For example, in the code fragment:
// a: do { break a; } while (++i < 10);
// the expression "++i < 10" is unreachable, but the as there is
// no unreachable statement, the Java Language Spec permits it.
// Set inItem to a default Item
dfIn = createInitDFI();
}
DataFlowItem dfOut = null;
if (outItems != null && !outItems.isEmpty()) {
// due to the flow equations, all DataFlowItems in the outItems map
// are the same, so just take the first one.
dfOut = (DataFlowItem) outItems.values().iterator().next();
}
if (n instanceof Local) {
checkLocal(graph, (Local) n, dfIn, dfOut);
} else if (n instanceof LocalAssign) {
checkLocalAssign(graph, (LocalAssign) n, dfIn, dfOut);
} else if (n instanceof FieldAssign) {
checkFieldAssign(graph, (FieldAssign) n, dfIn, dfOut);
} else if (n instanceof ClassBody) {
// we need to check that the locals used inside this class body
// have all been defined at this point.
Set localsUsed = (Set) currCBI.localsUsedInClassBodies.get(n);
if (localsUsed != null) {
checkLocalsUsedByInnerClass(graph, (ClassBody) n, localsUsed, dfIn, dfOut);
}
}
if (n == graph.finishNode()) {
if (currCBI.currCodeDecl instanceof Initializer) {
finishInitializer(graph, (Initializer) currCBI.currCodeDecl, dfIn, dfOut);
}
if (currCBI.currCodeDecl instanceof ConstructorDecl) {
finishConstructorDecl(graph, (ConstructorDecl) currCBI.currCodeDecl, dfIn, dfOut);
}
}
}
