/**
* If this is a putfield or putstatic instruction, check to see if the field is @NonNull, and
* treat it as dereferences.
*
* @param location the Location of the instruction
* @param vnaFrame the ValueNumberFrame at the Location of the instruction
* @param fact the dataflow value to modify
* @throws DataflowAnalysisException
*/
private void checkNonNullPutField(
Location location, ValueNumberFrame vnaFrame, UnconditionalValueDerefSet fact)
throws DataflowAnalysisException {
INullnessAnnotationDatabase database =
AnalysisContext.currentAnalysisContext().getNullnessAnnotationDatabase();
FieldInstruction fieldIns = (FieldInstruction) location.getHandle().getInstruction();
XField field = XFactory.createXField(fieldIns, methodGen.getConstantPool());
char firstChar = field.getSignature().charAt(0);
if (firstChar != 'L' && firstChar != '[') {
return;
}
NullnessAnnotation resolvedAnnotation = database.getResolvedAnnotation(field, true);
if (resolvedAnnotation == NullnessAnnotation.NONNULL) {
IsNullValueFrame invFrame = invDataflow.getFactAtLocation(location);
if (!invFrame.isValid()) {
return;
}
IsNullValue value = invFrame.getTopValue();
if (reportDereference(value)) {
ValueNumber vn = vnaFrame.getTopValue();
fact.addDeref(vn, location);
}
}
}
public static Set<ValueNumber> checkNonNullParams(
Location location,
ValueNumberFrame vnaFrame,
ConstantPoolGen constantPool,
@CheckForNull Method method,
@CheckForNull IsNullValueFrame invFrame)
throws DataflowAnalysisException {
if (invFrame != null && !invFrame.isValid()) {
return Collections.emptySet();
}
INullnessAnnotationDatabase database =
AnalysisContext.currentAnalysisContext().getNullnessAnnotationDatabase();
InvokeInstruction inv = (InvokeInstruction) location.getHandle().getInstruction();
XMethod called = XFactory.createXMethod(inv, constantPool);
SignatureParser sigParser = new SignatureParser(called.getSignature());
int numParams = sigParser.getNumParameters();
Set<ValueNumber> result = new HashSet<ValueNumber>();
Iterator<String> parameterIterator = sigParser.parameterSignatureIterator();
for (int i = 0; i < numParams; i++) {
String parameterSignature = parameterIterator.next();
char firstChar = parameterSignature.charAt(0);
if (firstChar != 'L' && firstChar != '[') {
continue;
}
int offset = sigParser.getSlotsFromTopOfStackForParameter(i);
if (invFrame != null) {
int slot = invFrame.getStackLocation(offset);
if (!reportDereference(invFrame, slot)) {
continue;
}
}
if (database.parameterMustBeNonNull(called, i)) {
int catchSizeNPE =
Util.getSizeOfSurroundingTryBlock(
method, "java/lang/NullPointerException", location.getHandle().getPosition());
int catchSizeNFE =
Util.getSizeOfSurroundingTryBlock(
method, "java/lang/NumberFormatException", location.getHandle().getPosition());
if (catchSizeNPE == Integer.MAX_VALUE
&& (!"java.lang.Integer".equals(called.getClassName())
|| catchSizeNFE == Integer.MAX_VALUE)) {
// Get the corresponding value number
ValueNumber vn = vnaFrame.getArgument(inv, constantPool, i, sigParser);
result.add(vn);
}
}
}
return result;
}
/**
* If this is a method call instruction, check to see if any of the parameters are @NonNull, and
* treat them as dereferences.
*
* @param location the Location of the instruction
* @param vnaFrame the ValueNumberFrame at the Location of the instruction
* @param fact the dataflow value to modify
* @throws DataflowAnalysisException
*/
private void checkNonNullReturnValue(
XMethod thisMethod,
Location location,
ValueNumberFrame vnaFrame,
UnconditionalValueDerefSet fact)
throws DataflowAnalysisException {
INullnessAnnotationDatabase database =
AnalysisContext.currentAnalysisContext().getNullnessAnnotationDatabase();
if (database.getResolvedAnnotation(thisMethod, true) != NullnessAnnotation.NONNULL) {
return;
}
if (reportPotentialDereference(location, invDataflow.getFactAtLocation(location))) {
ValueNumber vn = vnaFrame.getTopValue();
fact.addDeref(vn, location);
}
}