示例#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());
     }
   }
 }
示例#2
0
  /** Check that the assignment to a local variable is correct. */
  protected void checkLocalAssign(
      FlowGraph graph, LocalAssign a, DataFlowItem dfIn, DataFlowItem dfOut)
      throws SemanticException {
    LocalInstance li = ((Local) a.left()).localInstance();
    if (!currCBI.localDeclarations.contains(li)) {
      throw new SemanticException(
          "Final local variable \"" + li.name() + "\" cannot be assigned to in an inner class.",
          a.position());
    }

    MinMaxInitCount initCount = (MinMaxInitCount) dfOut.initStatus.get(li);

    if (li.flags().isFinal() && InitCount.MANY.equals(initCount.getMax())) {
      throw new SemanticException(
          "variable \"" + li.name() + "\" might already have been assigned to", a.position());
    }
  }