/**
* Compare to see if the argument <code>argType</code> passed to the method matches the type of
* the corresponding parameter. The simplest case is when both are equal.
*
* <p>This is a conservative comparison - returns true if it cannot decide. If the parameter type
* is a type variable (e.g. <code>T</code>) then we don't know enough (yet) to decide if they do
* not match so return true.
*
* @param ignoreBaseType TODO
*/
private IncompatibleTypes compareTypes(
Type expectedType, Type actualType, boolean ignoreBaseType) {
// XXX equality not implemented for GenericObjectType
// if (parmType.equals(argType)) return true;
if (expectedType == actualType) return IncompatibleTypes.SEEMS_OK;
// Compare type signatures instead
String expectedString = GenericUtilities.getString(expectedType);
String actualString = GenericUtilities.getString(actualType);
if (expectedString.equals(actualString)) return IncompatibleTypes.SEEMS_OK;
if (expectedType.equals(Type.OBJECT)) return IncompatibleTypes.SEEMS_OK;
// if either type is java.lang.Object, then automatically true!
// again compare strings...
String objString = GenericUtilities.getString(Type.OBJECT);
if (expectedString.equals(objString)) {
return IncompatibleTypes.SEEMS_OK;
}
// get a category for each type
TypeCategory expectedCat = GenericUtilities.getTypeCategory(expectedType);
TypeCategory argCat = GenericUtilities.getTypeCategory(actualType);
if (actualString.equals(objString) && expectedCat == TypeCategory.TYPE_VARIABLE) {
return IncompatibleTypes.SEEMS_OK;
}
if (ignoreBaseType) {
if (expectedCat == TypeCategory.PARAMETERIZED && argCat == TypeCategory.PARAMETERIZED) {
GenericObjectType parmGeneric = (GenericObjectType) expectedType;
GenericObjectType argGeneric = (GenericObjectType) actualType;
return compareTypeParameters(parmGeneric, argGeneric);
}
return IncompatibleTypes.SEEMS_OK;
}
if (actualType.equals(Type.OBJECT) && expectedCat == TypeCategory.ARRAY_TYPE)
return IncompatibleTypes.ARRAY_AND_OBJECT;
// -~- plain objects are easy
if (expectedCat == TypeCategory.PLAIN_OBJECT_TYPE && argCat == TypeCategory.PLAIN_OBJECT_TYPE)
return IncompatibleTypes.getPriorityForAssumingCompatible(expectedType, actualType, false);
if (expectedCat == TypeCategory.PARAMETERIZED && argCat == TypeCategory.PLAIN_OBJECT_TYPE)
return IncompatibleTypes.getPriorityForAssumingCompatible(
(GenericObjectType) expectedType, actualType);
if (expectedCat == TypeCategory.PLAIN_OBJECT_TYPE && argCat == TypeCategory.PARAMETERIZED)
return IncompatibleTypes.getPriorityForAssumingCompatible(
(GenericObjectType) actualType, expectedType);
// -~- parmType is: "? extends Another Type" OR "? super Another Type"
if (expectedCat == TypeCategory.WILDCARD_EXTENDS || expectedCat == TypeCategory.WILDCARD_SUPER)
return compareTypes(
((GenericObjectType) expectedType).getExtension(), actualType, ignoreBaseType);
// -~- Not handling type variables
if (expectedCat == TypeCategory.TYPE_VARIABLE || argCat == TypeCategory.TYPE_VARIABLE)
return IncompatibleTypes.SEEMS_OK;
// -~- Array Types: compare dimensions, then base type
if (expectedCat == TypeCategory.ARRAY_TYPE && argCat == TypeCategory.ARRAY_TYPE) {
ArrayType parmArray = (ArrayType) expectedType;
ArrayType argArray = (ArrayType) actualType;
if (parmArray.getDimensions() != argArray.getDimensions())
return IncompatibleTypes.ARRAY_AND_NON_ARRAY;
return compareTypes(parmArray.getBasicType(), argArray.getBasicType(), ignoreBaseType);
}
// If one is an Array Type and the other is not, then they
// are incompatible. (We already know neither is java.lang.Object)
if (expectedCat == TypeCategory.ARRAY_TYPE ^ argCat == TypeCategory.ARRAY_TYPE) {
return IncompatibleTypes.ARRAY_AND_NON_ARRAY;
}
// -~- Parameter Types: compare base type then parameters
if (expectedCat == TypeCategory.PARAMETERIZED && argCat == TypeCategory.PARAMETERIZED) {
GenericObjectType parmGeneric = (GenericObjectType) expectedType;
GenericObjectType argGeneric = (GenericObjectType) actualType;
// base types should be related
{
IncompatibleTypes result =
compareTypes(parmGeneric.getObjectType(), argGeneric.getObjectType(), ignoreBaseType);
if (!result.equals(IncompatibleTypes.SEEMS_OK)) return result;
}
return compareTypeParameters(parmGeneric, argGeneric);
// XXX More to come
}
// If one is a Parameter Type and the other is not, then they
// are incompatible. (We already know neither is java.lang.Object)
if (false) {
// not true. Consider class Foo extends ArrayList<String>
if (expectedCat == TypeCategory.PARAMETERIZED ^ argCat == TypeCategory.PARAMETERIZED) {
return IncompatibleTypes.SEEMS_OK; // fix this when we know what
// we are doing here
}
}
// -~- Wildcard e.g. List<*>.contains(...)
if (expectedCat == TypeCategory.WILDCARD) // No Way to know
return IncompatibleTypes.SEEMS_OK;
// -~- Non Reference types
// if ( parmCat == TypeCategory.NON_REFERENCE_TYPE ||
// argCat == TypeCategory.NON_REFERENCE_TYPE )
if (expectedType instanceof BasicType || actualType instanceof BasicType) {
// this should not be possible, compiler will complain (pre 1.5)
// or autobox primitive types (1.5 +)
throw new IllegalArgumentException(
"checking for compatibility of " + expectedType + " with " + actualType);
}
return IncompatibleTypes.SEEMS_OK;
}
private void analyzeMethod(ClassContext classContext, Method method)
throws CFGBuilderException, DataflowAnalysisException {
if (isSynthetic(method) || !prescreen(classContext, method)) return;
XMethod xmethod = XFactory.createXMethod(classContext.getJavaClass(), method);
if (xmethod.isSynthetic()) return;
BugAccumulator accumulator = new BugAccumulator(bugReporter);
CFG cfg = classContext.getCFG(method);
TypeDataflow typeDataflow = classContext.getTypeDataflow(method);
ValueNumberDataflow vnDataflow = classContext.getValueNumberDataflow(method);
ConstantPoolGen cpg = classContext.getConstantPoolGen();
MethodGen methodGen = classContext.getMethodGen(method);
if (methodGen == null) return;
String fullMethodName = methodGen.getClassName() + "." + methodGen.getName();
String sourceFile = classContext.getJavaClass().getSourceFileName();
if (DEBUG) {
System.out.println("\n" + fullMethodName);
}
// Process each instruction
for (Iterator<Location> iter = cfg.locationIterator(); iter.hasNext(); ) {
Location location = iter.next();
InstructionHandle handle = location.getHandle();
Instruction ins = handle.getInstruction();
// Only consider invoke instructions
if (!(ins instanceof InvokeInstruction)) continue;
InvokeInstruction inv = (InvokeInstruction) ins;
XMethod invokedMethod = XFactory.createXMethod(inv, cpg);
String invokedMethodName = invokedMethod.getName();
String argSignature = invokedMethod.getSignature();
argSignature = argSignature.substring(0, argSignature.indexOf(')') + 1);
String call = invokedMethodName + argSignature;
SignatureParser sigParser = new SignatureParser(inv.getSignature(cpg));
Collection<Info> collection = callMap.get(call);
if (!callMap.containsKey(call)) continue;
for (Info info : collection) {
Subtypes2 subtypes2 = AnalysisContext.currentAnalysisContext().getSubtypes2();
if (DEBUG)
System.out.println(
"at "
+ handle.getPosition()
+ " Checking call to "
+ info.interfaceForCall
+ " : "
+ invokedMethod);
try {
if (!subtypes2.isSubtype(invokedMethod.getClassDescriptor(), info.interfaceForCall))
continue;
} catch (ClassNotFoundException e) {
if (info.interfaceForCall.getClassName().equals("java/util/Collection")
&& invokedMethod.getClassName().equals("com.google.common.collect.Multiset")) {
assert true;
// we know this is OK without needing to find definition of Multiset
} else {
AnalysisContext.reportMissingClass(e);
continue;
}
}
boolean allMethod;
int typeArgument;
if (info.typeIndex >= 0) {
allMethod = false;
typeArgument = info.typeIndex;
} else {
allMethod = true;
typeArgument = -(1 + info.typeIndex);
}
int pos = info.argumentIndex;
int lhsPos;
if (inv instanceof INVOKESTATIC) lhsPos = sigParser.getSlotsFromTopOfStackForParameter(0);
else lhsPos = sigParser.getTotalArgumentSize();
int stackPos = sigParser.getSlotsFromTopOfStackForParameter(pos);
TypeFrame frame = typeDataflow.getFactAtLocation(location);
if (!frame.isValid()) {
// This basic block is probably dead
continue;
}
Type operandType = frame.getStackValue(stackPos);
if (operandType.equals(TopType.instance())) {
// unreachable
continue;
}
if (operandType.equals(NullType.instance())) {
// ignore
continue;
}
ValueNumberFrame vnFrame = vnDataflow.getFactAtLocation(location);
if (!vnFrame.isValid()) {
AnalysisContext.logError("Invalid value number frame in " + xmethod);
continue;
}
ValueNumber objectVN = vnFrame.getStackValue(lhsPos);
ValueNumber argVN = vnFrame.getStackValue(stackPos);
if (objectVN.equals(argVN)) {
String bugPattern = "DMI_COLLECTIONS_SHOULD_NOT_CONTAIN_THEMSELVES";
int priority = HIGH_PRIORITY;
if (invokedMethodName.equals("removeAll")) {
bugPattern = "DMI_USING_REMOVEALL_TO_CLEAR_COLLECTION";
priority = NORMAL_PRIORITY;
} else if (invokedMethodName.endsWith("All")) {
bugPattern = "DMI_VACUOUS_SELF_COLLECTION_CALL";
priority = NORMAL_PRIORITY;
}
if (invokedMethodName.startsWith("contains")) {
InstructionHandle next = handle.getNext();
if (next != null) {
Instruction nextIns = next.getInstruction();
if (nextIns instanceof InvokeInstruction) {
XMethod nextMethod = XFactory.createXMethod((InvokeInstruction) nextIns, cpg);
if (nextMethod.getName().equals("assertFalse")) continue;
}
}
}
accumulator.accumulateBug(
new BugInstance(this, bugPattern, priority)
.addClassAndMethod(methodGen, sourceFile)
.addCalledMethod(methodGen, (InvokeInstruction) ins)
.addOptionalAnnotation(
ValueNumberSourceInfo.findAnnotationFromValueNumber(
method, location, objectVN, vnFrame, "INVOKED_ON")),
SourceLineAnnotation.fromVisitedInstruction(
classContext, methodGen, sourceFile, handle));
}
// Only consider generic...
Type objectType = frame.getStackValue(lhsPos);
if (!(objectType instanceof GenericObjectType)) continue;
GenericObjectType operand = (GenericObjectType) objectType;
int expectedTypeParameters = 1;
String simpleName = info.interfaceForCall.getSimpleName();
if (simpleName.toLowerCase().endsWith("map") || simpleName.equals("Hashtable"))
expectedTypeParameters = 2;
else if (simpleName.equals("Table")) expectedTypeParameters = 3;
// ... containers
if (!operand.hasParameters()) continue;
if (operand.getNumParameters() != expectedTypeParameters) continue;
ClassDescriptor operandClass = DescriptorFactory.getClassDescriptor(operand);
if (!isGenericCollection(operandClass)) continue;
if (expectedTypeParameters == 2
&& Subtypes2.instanceOf(operandClass, Map.class)
&& !TypeFrameModelingVisitor.isStraightGenericMap(operandClass)) continue;
Type expectedType;
if (allMethod) expectedType = operand;
else expectedType = operand.getParameterAt(typeArgument);
Type actualType = frame.getStackValue(stackPos);
Type equalsType = actualType;
if (allMethod) {
if (!(actualType instanceof GenericObjectType)) {
continue;
}
equalsType = ((GenericObjectType) actualType).getParameterAt(typeArgument);
}
IncompatibleTypes matchResult = compareTypes(expectedType, actualType, allMethod);
boolean parmIsObject = expectedType.getSignature().equals("Ljava/lang/Object;");
boolean selfOperation = !allMethod && operand.equals(actualType) && !parmIsObject;
if (!allMethod && !parmIsObject && actualType instanceof GenericObjectType) {
GenericObjectType p2 = (GenericObjectType) actualType;
List<? extends ReferenceType> parameters = p2.getParameters();
if (parameters != null && parameters.equals(operand.getParameters()))
selfOperation = true;
}
if (!selfOperation
&& (matchResult == IncompatibleTypes.SEEMS_OK
|| matchResult.getPriority() == Priorities.IGNORE_PRIORITY)) continue;
if (invokedMethodName.startsWith("contains") || invokedMethodName.equals("remove")) {
InstructionHandle next = handle.getNext();
if (next != null) {
Instruction nextIns = next.getInstruction();
if (nextIns instanceof InvokeInstruction) {
XMethod nextMethod = XFactory.createXMethod((InvokeInstruction) nextIns, cpg);
if (nextMethod.getName().equals("assertFalse")) continue;
}
}
} else if (invokedMethodName.equals("get") || invokedMethodName.equals("remove")) {
InstructionHandle next = handle.getNext();
if (next != null) {
Instruction nextIns = next.getInstruction();
if (nextIns instanceof InvokeInstruction) {
XMethod nextMethod = XFactory.createXMethod((InvokeInstruction) nextIns, cpg);
if (nextMethod.getName().equals("assertNull")) continue;
}
}
}
boolean noisy = false;
if (invokedMethodName.equals("get")) {
UnconditionalValueDerefDataflow unconditionalValueDerefDataflow =
classContext.getUnconditionalValueDerefDataflow(method);
UnconditionalValueDerefSet unconditionalDeref =
unconditionalValueDerefDataflow.getFactAtLocation(location);
ValueNumberFrame vnAfter = vnDataflow.getFactAfterLocation(location);
ValueNumber top = vnAfter.getTopValue();
noisy =
unconditionalDeref.getValueNumbersThatAreUnconditionallyDereferenced().contains(top);
}
// Prepare bug report
SourceLineAnnotation sourceLineAnnotation =
SourceLineAnnotation.fromVisitedInstruction(
classContext, methodGen, sourceFile, handle);
// Report a bug that mentions each of the failed arguments in
// matches
if (expectedType instanceof GenericObjectType)
expectedType = ((GenericObjectType) expectedType).getUpperBound();
int priority = matchResult.getPriority();
if (!operandClass.getClassName().startsWith("java/util")
&& priority == Priorities.HIGH_PRIORITY)
priority = Math.max(priority, Priorities.NORMAL_PRIORITY);
if (TestCaseDetector.likelyTestCase(xmethod))
priority = Math.max(priority, Priorities.NORMAL_PRIORITY);
else if (selfOperation) priority = Priorities.HIGH_PRIORITY;
ClassDescriptor expectedClassDescriptor =
DescriptorFactory.createClassOrObjectDescriptorFromSignature(
expectedType.getSignature());
ClassDescriptor actualClassDescriptor =
DescriptorFactory.createClassOrObjectDescriptorFromSignature(equalsType.getSignature());
ClassSummary classSummary = AnalysisContext.currentAnalysisContext().getClassSummary();
Set<XMethod> targets = null;
try {
targets =
Hierarchy2.resolveVirtualMethodCallTargets(
actualClassDescriptor, "equals", "(Ljava/lang/Object;)Z", false, false);
boolean allOk = targets.size() > 0;
for (XMethod m2 : targets)
if (!classSummary.mightBeEqualTo(m2.getClassDescriptor(), expectedClassDescriptor))
allOk = false;
if (allOk) priority += 2;
} catch (ClassNotFoundException e) {
AnalysisContext.reportMissingClass(e);
}
String bugPattern = "GC_UNRELATED_TYPES";
BugInstance bug =
new BugInstance(this, bugPattern, priority)
.addClassAndMethod(methodGen, sourceFile)
.addFoundAndExpectedType(actualType, expectedType)
.addCalledMethod(methodGen, (InvokeInstruction) ins)
.addOptionalAnnotation(
ValueNumberSourceInfo.findAnnotationFromValueNumber(
method, location, objectVN, vnFrame, "INVOKED_ON"))
.addOptionalAnnotation(
ValueNumberSourceInfo.findAnnotationFromValueNumber(
method, location, argVN, vnFrame, "ARGUMENT"))
.addEqualsMethodUsed(targets);
if (noisy) {
WarningPropertySet<WarningProperty> propertySet =
new WarningPropertySet<WarningProperty>();
propertySet.addProperty(GeneralWarningProperty.NOISY_BUG);
propertySet.decorateBugInstance(bug);
}
accumulator.accumulateBug(bug, sourceLineAnnotation);
}
}
accumulator.reportAccumulatedBugs();
}
