/** 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());
}
}
}
/** 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());
}
}