/** * 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); } } }