/**
* Check that the set of <code>LocalInstance</code>s <code>localsUsed</code>, which is the set of
* locals used in the inner class declared by <code>cb</code> are initialized before the class
* declaration.
*/
protected void checkLocalsUsedByInnerClass(
FlowGraph graph, ClassBody cb, Set localsUsed, DataFlowItem dfIn, DataFlowItem dfOut)
throws SemanticException {
for (Iterator iter = localsUsed.iterator(); iter.hasNext(); ) {
LocalInstance li = (LocalInstance) iter.next();
MinMaxInitCount initCount = (MinMaxInitCount) dfOut.initStatus.get(li);
if (!currCBI.localDeclarations.contains(li)) {
// the local wasn't defined in this scope.
currCBI.outerLocalsUsed.add(li);
} else if (initCount == null || InitCount.ZERO.equals(initCount.getMin())) {
// initCount will in general not be null, as the local variable
// li is declared in the current class; however, if the inner
// class is declared in the initializer of the local variable
// declaration, then initCount could in fact be null, as we
// leave the inner class before we have performed flowLocalDecl
// for the local variable declaration.
throw new SemanticException(
"Local variable \""
+ li.name()
+ "\" must be initialized before the class "
+ "declaration.",
cb.position());
}
}
}
/**
* Check that each static final field is initialized exactly once.
*
* @param cb The ClassBody of the class declaring the fields to check.
* @throws SemanticException
*/
protected void checkStaticFinalFieldsInit(ClassBody cb) throws SemanticException {
// check that all static fields have been initialized exactly once.
for (Iterator iter = currCBI.currClassFinalFieldInitCounts.entrySet().iterator();
iter.hasNext(); ) {
Map.Entry e = (Map.Entry) iter.next();
if (e.getKey() instanceof FieldInstance) {
FieldInstance fi = (FieldInstance) e.getKey();
if (fi.flags().isStatic() && fi.flags().isFinal()) {
MinMaxInitCount initCount = (MinMaxInitCount) e.getValue();
if (InitCount.ZERO.equals(initCount.getMin())) {
throw new SemanticException(
"field \"" + fi.name() + "\" might not have been initialized", cb.position());
}
}
}
}
}
/**
* Check that each non static final field has been initialized exactly once, taking into account
* the fact that constructors may call other constructors.
*
* @param cb The ClassBody of the class declaring the fields to check.
* @throws SemanticException
*/
protected void checkNonStaticFinalFieldsInit(ClassBody cb) throws SemanticException {
// for each non-static final field instance, check that all
// constructors intialize it exactly once, taking into account constructor calls.
for (Iterator iter = currCBI.currClassFinalFieldInitCounts.keySet().iterator();
iter.hasNext(); ) {
FieldInstance fi = (FieldInstance) iter.next();
if (fi.flags().isFinal() && !fi.flags().isStatic()) {
// the field is final and not static
// it must be initialized exactly once.
// navigate up through all of the the constructors
// that this constructor calls.
boolean fieldInitializedBeforeConstructors = false;
MinMaxInitCount ic = (MinMaxInitCount) currCBI.currClassFinalFieldInitCounts.get(fi);
if (ic != null && !InitCount.ZERO.equals(ic.getMin())) {
fieldInitializedBeforeConstructors = true;
}
for (Iterator iter2 = currCBI.allConstructors.iterator(); iter2.hasNext(); ) {
ConstructorDecl cd = (ConstructorDecl) iter2.next();
ConstructorInstance ciStart = cd.constructorInstance();
ConstructorInstance ci = ciStart;
boolean isInitialized = fieldInitializedBeforeConstructors;
while (ci != null) {
Set s = (Set) currCBI.fieldsConstructorInitializes.get(ci);
if (s != null && s.contains(fi)) {
if (isInitialized) {
throw new SemanticException(
"field \"" + fi.name() + "\" might have already been initialized",
cd.position());
}
isInitialized = true;
}
ci = (ConstructorInstance) currCBI.constructorCalls.get(ci);
}
if (!isInitialized) {
throw new SemanticException(
"field \"" + fi.name() + "\" might not have been initialized", ciStart.position());
}
}
}
}
}
/** Check that the local variable <code>l</code> is used correctly. */
protected void checkLocal(FlowGraph graph, Local l, DataFlowItem dfIn, DataFlowItem dfOut)
throws SemanticException {
if (!currCBI.localDeclarations.contains(l.localInstance())) {
// it's a local variable that has not been declared within
// this scope. The only way this can arise is from an
// inner class that is not a member of a class (typically
// a local class, or an anonymous class declared in a method,
// constructor or initializer).
// We need to check that it is a final local, and also
// keep track of it, to ensure that it has been definitely
// assigned at this point.
currCBI.outerLocalsUsed.add(l.localInstance());
} else {
MinMaxInitCount initCount = (MinMaxInitCount) dfIn.initStatus.get(l.localInstance());
if (initCount != null && InitCount.ZERO.equals(initCount.getMin())) {
// the local variable may not have been initialized.
// However, we only want to complain if the local is reachable
if (l.reachable()) {
throw new SemanticException(
"Local variable \"" + l.name() + "\" may not have been initialized", l.position());
}
}
}
}