Ejemplo n.º 1
0
 /** Check that the assignment to a field is correct. */
 protected void checkFieldAssign(
     FlowGraph graph, FieldAssign a, DataFlowItem dfIn, DataFlowItem dfOut)
     throws SemanticException {
   Field f = (Field) a.left();
   FieldInstance fi = f.fieldInstance();
   if (fi.flags().isFinal()) {
     if ((currCBI.currCodeDecl instanceof ConstructorDecl
             || currCBI.currCodeDecl instanceof Initializer)
         && isFieldsTargetAppropriate(f)) {
       // we are in a constructor or initializer block and
       // if the field is static then the target is the class
       // at hand, and if it is not static then the
       // target of the field is this.
       // So a final field in this situation can be
       // assigned to at most once.
       MinMaxInitCount initCount = (MinMaxInitCount) dfOut.initStatus.get(fi);
       if (InitCount.MANY.equals(initCount.getMax())) {
         throw new SemanticException(
             "field \"" + fi.name() + "\" might already have been assigned to", a.position());
       }
     } else {
       // not in a constructor or intializer, or the target is
       // not appropriate. So we cannot assign
       // to a final field at all.
       throw new SemanticException(
           "Cannot assign a value " + "to final field \"" + fi.name() + "\"", a.position());
     }
   }
 }
Ejemplo n.º 2
0
  /** Perform the appropriate flow operations for assignment to a field */
  protected Map flowFieldAssign(
      DataFlowItem inItem, FlowGraph graph, FieldAssign a, Set succEdgeKeys) {
    Field f = (Field) a.left();
    FieldInstance fi = f.fieldInstance();

    if (fi.flags().isFinal() && isFieldsTargetAppropriate(f)) {
      // this field is final and the target for this field is
      // appropriate for what we are interested in.
      Map m = new HashMap(inItem.initStatus);
      MinMaxInitCount initCount = (MinMaxInitCount) m.get(fi);
      // initCount may be null if the field is defined in an
      // outer class.
      if (initCount != null) {
        initCount =
            new MinMaxInitCount(initCount.getMin().increment(), initCount.getMax().increment());
        m.put(fi, initCount);
        return itemToMap(new DataFlowItem(m), succEdgeKeys);
      }
    }
    return null;
  }