Java Code Examples for org.apache.bcel.generic.INVOKESTATIC

/**
 * Find the declared exceptions for the method called by given instruction.
 *
 * @param inv
 *            the InvokeInstruction
 * @param cpg
 *            the ConstantPoolGen used by the class the InvokeInstruction
 *            belongs to
 * @return array of ObjectTypes of thrown exceptions, or null if we can't
 *         find the method implementation
 */
public static @CheckForNull ObjectType[] findDeclaredExceptions(InvokeInstruction inv, ConstantPoolGen cpg) {
    XMethod method = findInvocationLeastUpperBound(inv, cpg, inv instanceof INVOKESTATIC ? STATIC_METHOD : INSTANCE_METHOD);

    if (method == null) {
        return null;
    }
    String[] exceptions = method.getThrownExceptions();

    if (exceptions == null) {
        return new ObjectType[0];
    }

    ObjectType[] result = new ObjectType[exceptions.length];
    for (int i = 0; i < exceptions.length; ++i) {
        result[i] = ObjectTypeFactory.getInstance(ClassName.toDottedClassName(exceptions[i]));
    }
    return result;
}
 

/** Checks if the constraints of operands of the said instruction(s) are satisfied. */
@Override
public void visitINVOKESTATIC(final INVOKESTATIC o) {
    try {
    // INVOKESTATIC is a LoadClass; the Class where the referenced method is declared in,
    // is therefore resolved/verified.
    // INVOKESTATIC is an InvokeInstruction, the argument and return types are resolved/verified,
    // too. So are the allowed method names.
    final String classname = o.getClassName(constantPoolGen);
    final JavaClass jc = Repository.lookupClass(classname);
    final Method m = getMethodRecursive(jc, o);
    if (m == null) {
        constraintViolated(o, "Referenced method '"+o.getMethodName(constantPoolGen)+"' with expected signature '"+
            o.getSignature(constantPoolGen) +"' not found in class '"+jc.getClassName()+"'.");
    } else if (! (m.isStatic())) { // implies it's not abstract, verified in pass 2.
        constraintViolated(o, "Referenced method '"+o.getMethodName(constantPoolGen)+"' has ACC_STATIC unset.");
    }

    } catch (final ClassNotFoundException e) {
    // FIXME: maybe not the best way to handle this
    throw new AssertionViolatedException("Missing class: " + e, e);
    }
}
 

/**
 * Is the given instruction a self-call?
 */
private Method isSelfCall(InvokeInstruction inv) {
    ConstantPoolGen cpg = classContext.getConstantPoolGen();
    JavaClass jclass = classContext.getJavaClass();

    String calledClassName = inv.getClassName(cpg);

    // FIXME: is it possible we would see a superclass name here?
    // Not a big deal for now, as we are mostly just interested in calls
    // to private methods, for which we will definitely see the right
    // called class name.
    if (!calledClassName.equals(jclass.getClassName())) {
        return null;
    }

    String calledMethodName = inv.getMethodName(cpg);
    String calledMethodSignature = inv.getSignature(cpg);
    boolean isStaticCall = (inv instanceof INVOKESTATIC);

    // Scan methods for one that matches.
    Method[] methods = jclass.getMethods();
    for (Method method : methods) {
        String methodName = method.getName();
        String signature = method.getSignature();
        boolean isStatic = method.isStatic();

        if (methodName.equals(calledMethodName) && signature.equals(calledMethodSignature) && isStatic == isStaticCall) {
            // This method looks like a match.
            return wantCallsFor(method) ? method : null;
        }
    }

    // Hmm...no matching method found.
    // This is almost certainly because the named method
    // was inherited from a superclass.
    LOG.debug("No method found for {}.{} : {}", calledClassName, calledMethodName, calledMethodSignature);
    return null;
}
 

/**
 * Use this to screen out methods that do not contain invocations.
 */
public boolean prescreen(ClassContext classContext, Method method) {
    BitSet bytecodeSet = classContext.getBytecodeSet(method);
    return bytecodeSet != null
            && (bytecodeSet.get(Const.INVOKEINTERFACE) || bytecodeSet.get(Const.INVOKEVIRTUAL)
                    || bytecodeSet.get(Const.INVOKESPECIAL) || bytecodeSet.get(Const.INVOKESTATIC) || bytecodeSet
                            .get(Const.INVOKENONVIRTUAL));
}
 

@Override
public void visitINVOKESTATIC(INVOKESTATIC obj) {
    if (returnsString(obj)) {
        consumeStack(obj);

        String className = obj.getClassName(getCPG());
        if (Values.DOTTED_JAVA_LANG_STRING.equals(className)) {
            pushValue(dynamicStringTypeInstance);
        } else {
            pushReturnType(obj);
        }
    } else {
        super.visitINVOKESTATIC(obj);
    }
}
 

public MethodDescriptor getInvokedMethod(ConstantPoolGen cpg, InvokeInstruction inv) {
    String invoked = inv.getClassName(cpg);
    String methodName = inv.getMethodName(cpg);
    String methodSig = inv.getSignature(cpg);
    MethodDescriptor invokedMethod =
            DescriptorFactory.instance().getMethodDescriptor(ClassName.toSlashedClassName(invoked), methodName, methodSig,
                    inv instanceof INVOKESTATIC);
    return invokedMethod;
}
 

private boolean prescreen(ClassContext classContext, Method method) {
    BitSet bytecodeSet = classContext.getBytecodeSet(method);
    if (bytecodeSet == null
            // method must acquire a lock
            || (!bytecodeSet.get(Const.MONITORENTER) && !method.isSynchronized())) {
        return false;
    }

    // and contain a static method invocation
    return bytecodeSet.get(Const.INVOKESTATIC);
}
 

private void analyzeMethod(ClassContext classContext, Method method) throws CFGBuilderException, DataflowAnalysisException {
    // System.out.println("Checking " + method);

    CFG cfg = classContext.getCFG(method);
    LockDataflow lockDataflow = classContext.getLockDataflow(method);

    for (Iterator<Location> i = cfg.locationIterator(); i.hasNext();) {
        Location location = i.next();
        Instruction ins = location.getHandle().getInstruction();

        if (!(ins instanceof INVOKESTATIC)) {
            continue;
        }

        if (!isSleep((INVOKESTATIC) ins, classContext.getConstantPoolGen())) {
            continue;
        }

        // System.out.println("Found sleep at " + location.getHandle());

        LockSet lockSet = lockDataflow.getFactAtLocation(location);
        if (lockSet.getNumLockedObjects() > 0) {
            bugAccumulator.accumulateBug(
                    new BugInstance(this, "SWL_SLEEP_WITH_LOCK_HELD", NORMAL_PRIORITY).addClassAndMethod(
                            classContext.getJavaClass(), method), classContext, method, location);
        }
    }
    bugAccumulator.reportAccumulatedBugs();
}
 

private boolean isSleep(INVOKESTATIC ins, ConstantPoolGen cpg) {
    String className = ins.getClassName(cpg);
    if (!"java.lang.Thread".equals(className)) {
        return false;
    }
    String methodName = ins.getMethodName(cpg);
    String signature = ins.getSignature(cpg);

    return "sleep".equals(methodName) && ("(J)V".equals(signature) || "(JI)V".equals(signature));
}
 

@Override
public void visitINVOKESTATIC(INVOKESTATIC ins) {
    // Find calls to System.exit(), since this effectively terminates the
    // basic block.

    String className = ins.getClassName(constPoolGen);
    String methodName = ins.getName(constPoolGen);
    String methodSig = ins.getSignature(constPoolGen);

    if ("java.lang.System".equals(className) && "exit".equals(methodName) && "(I)V".equals(methodSig)) {
        isExit = true;
    }
}
 

public void visitInvokeOnException(Instruction obj) {
    if (!REDUNDANT_LOAD_ELIMINATION || !getFrame().hasAvailableLoads()) {
        return;
    }
    if (obj instanceof INVOKEDYNAMIC) {
        killLoadsOfObjectsPassed((INVOKEDYNAMIC) obj);
        return;
    }
    InvokeInstruction inv = (InvokeInstruction) obj;
    if ((inv instanceof INVOKEINTERFACE || inv instanceof INVOKEVIRTUAL)
            && inv.getMethodName(cpg).toLowerCase().indexOf("lock") >= 0) {
        // Don't know what this method invocation is doing.
        // Kill all loads.
        getFrame().killAllLoads();
        return;
    }
    if (inv instanceof INVOKEVIRTUAL && "cast".equals(inv.getMethodName(cpg)) && "java.lang.Class".equals(inv.getClassName(cpg))) {
        // No-op
        return;
    }
    if (inv instanceof INVOKESTATIC) {
        String methodName = inv.getName(cpg);
        if (("forName".equals(methodName) && "java.lang.Class".equals(inv.getClassName(cpg)) || "class$".equals(methodName))
                && "(Ljava/lang/String;)Ljava/lang/Class;".equals(inv.getSignature(cpg))
                || (Hierarchy.isInnerClassAccess((INVOKESTATIC) inv, cpg) && loadedFieldSet.getField(handle) != null)) {
            return;
        }
    }

    killLoadsOfObjectsPassed(inv);
    if (inv instanceof INVOKESTATIC) {
        getFrame().killAllLoadsOf(null);
    }
}
 

/**
 * Determine if given Instruction is a monitor wait.
 *
 * @param ins
 *            the Instruction
 * @param cpg
 *            the ConstantPoolGen for the Instruction
 *
 * @return true if the instruction is a monitor wait, false if not
 */
public static boolean isMonitorWait(Instruction ins, ConstantPoolGen cpg) {
    if (!(ins instanceof InvokeInstruction)) {
        return false;
    }
    if (ins.getOpcode() == Const.INVOKESTATIC) {
        return false;
    }

    InvokeInstruction inv = (InvokeInstruction) ins;
    String methodName = inv.getMethodName(cpg);
    String methodSig = inv.getSignature(cpg);

    return isMonitorWait(methodName, methodSig);
}
 

/**
 * Determine if given Instruction is a monitor wait.
 *
 * @param ins
 *            the Instruction
 * @param cpg
 *            the ConstantPoolGen for the Instruction
 *
 * @return true if the instruction is a monitor wait, false if not
 */
public static boolean isMonitorNotify(Instruction ins, ConstantPoolGen cpg) {
    if (!(ins instanceof InvokeInstruction)) {
        return false;
    }
    if (ins.getOpcode() == Const.INVOKESTATIC) {
        return false;
    }

    InvokeInstruction inv = (InvokeInstruction) ins;
    String methodName = inv.getMethodName(cpg);
    String methodSig = inv.getSignature(cpg);

    return isMonitorNotify(methodName, methodSig);
}
 

/**
 * Get the InnerClassAccess for access method called by given INVOKESTATIC.
 *
 * @param inv
 *            the INVOKESTATIC instruction
 * @param cpg
 *            the ConstantPoolGen for the method
 * @return the InnerClassAccess, or null if the instruction is not an
 *         inner-class access
 */
public static InnerClassAccess getInnerClassAccess(INVOKESTATIC inv, ConstantPoolGen cpg) throws ClassNotFoundException {

    String className = inv.getClassName(cpg);
    String methodName = inv.getName(cpg);
    String methodSig = inv.getSignature(cpg);

    InnerClassAccess access = AnalysisContext.currentAnalysisContext().getInnerClassAccessMap()
            .getInnerClassAccess(className, methodName);
    return (access != null && access.getMethodSignature().equals(methodSig)) ? access : null;
}
 

@Override
public void visitINVOKESTATIC(INVOKESTATIC obj) {
    visitInvoke(obj);
}
 

private void inspectLocation(JavaClass jclass, ConstantPoolGen cpg, Method method, MethodGen methodGen,
        LinkedList<WarningWithProperties> refComparisonList, LinkedList<WarningWithProperties> stringComparisonList,
        RefComparisonTypeFrameModelingVisitor visitor, TypeDataflow typeDataflow, Location location)
        throws DataflowAnalysisException {
    Instruction ins = location.getHandle().getInstruction();
    short opcode = ins.getOpcode();
    if (opcode == Const.IF_ACMPEQ || opcode == Const.IF_ACMPNE) {
        checkRefComparison(location, jclass, method, methodGen, visitor, typeDataflow, stringComparisonList,
                refComparisonList);
    } else if (ins instanceof InvokeInstruction) {
        InvokeInstruction inv = (InvokeInstruction) ins;
        boolean isStatic = inv instanceof INVOKESTATIC;
        @DottedClassName
        String className = inv.getClassName(cpg);
        String methodName = inv.getMethodName(cpg);
        String methodSig = inv.getSignature(cpg);
        if ("assertSame".equals(methodName) && "(Ljava/lang/Object;Ljava/lang/Object;)V".equals(methodSig)) {
            checkRefComparison(location, jclass, method, methodGen, visitor, typeDataflow, stringComparisonList,
                    refComparisonList);
        } else if ("assertFalse".equals(methodName) && "(Z)V".equals(methodSig)) {
            SourceLineAnnotation lastLocation = bugAccumulator.getLastBugLocation();
            InstructionHandle prevHandle = location.getHandle().getPrev();
            if (lastLocation != null && prevHandle != null && lastLocation.getEndBytecode() == prevHandle.getPosition()) {
                bugAccumulator.forgetLastBug();
                if (DEBUG) {
                    System.out.println("Forgetting last bug due to call to " + className + "." + methodName);
                }
            }

        } else {
            boolean equalsMethod = !isStatic && "equals".equals(methodName) && "(Ljava/lang/Object;)Z".equals(methodSig)
                    || isStatic && "assertEquals".equals(methodName)
                            && "(Ljava/lang/Object;Ljava/lang/Object;)V".equals(methodSig)
                    || isStatic && "equal".equals(methodName) && "(Ljava/lang/Object;Ljava/lang/Object;)Z".equals(methodSig)
                            && "com.google.common.base.Objects".equals(className)
                    || isStatic && "equals".equals(methodName) && "(Ljava/lang/Object;Ljava/lang/Object;)Z".equals(methodSig)
                            && "java.util.Objects".equals(className);

            if (equalsMethod) {
                checkEqualsComparison(location, jclass, method, methodGen, cpg, typeDataflow);
            }
        }
    }

}
 

private void checkRefComparison(Location location, JavaClass jclass, Method method, MethodGen methodGen,
        RefComparisonTypeFrameModelingVisitor visitor, TypeDataflow typeDataflow,
        List<WarningWithProperties> stringComparisonList, List<WarningWithProperties> refComparisonList)
        throws DataflowAnalysisException {

    InstructionHandle handle = location.getHandle();

    TypeFrame frame = typeDataflow.getFactAtLocation(location);
    if (frame.getStackDepth() < 2) {
        throw new DataflowAnalysisException("Stack underflow", methodGen, handle);
    }

    int numSlots = frame.getNumSlots();
    Type lhsType = frame.getValue(numSlots - 2);
    Type rhsType = frame.getValue(numSlots - 1);

    if (lhsType instanceof NullType || rhsType instanceof NullType) {
        return;
    }
    if (lhsType instanceof ReferenceType && rhsType instanceof ReferenceType) {
        IncompatibleTypes result = IncompatibleTypes.getPriorityForAssumingCompatible(lhsType, rhsType, true);
        if (result != IncompatibleTypes.SEEMS_OK && result != IncompatibleTypes.UNCHECKED) {
            String sourceFile = jclass.getSourceFileName();

            boolean isAssertSame = handle.getInstruction() instanceof INVOKESTATIC;
            if (isAssertSame) {
                if (testingEnabled) {
                    bugAccumulator.accumulateBug(
                            new BugInstance(this, "TESTING", result.getPriority())
                                    .addClassAndMethod(methodGen, sourceFile)
                                    .addString("Calling assertSame with two distinct objects")
                                    .addFoundAndExpectedType(rhsType, lhsType)
                                    .addSomeSourceForTopTwoStackValues(classContext, method, location),
                            SourceLineAnnotation.fromVisitedInstruction(classContext, methodGen, sourceFile, handle));
                }
            } else {
                bugAccumulator.accumulateBug(
                        new BugInstance(this, "EC_UNRELATED_TYPES_USING_POINTER_EQUALITY", result.getPriority())
                                .addClassAndMethod(methodGen, sourceFile).addFoundAndExpectedType(rhsType, lhsType)
                                .addSomeSourceForTopTwoStackValues(classContext, method, location),
                        SourceLineAnnotation.fromVisitedInstruction(classContext, methodGen, sourceFile, handle));
            }
            return;
        }
        if (lhsType.equals(Type.OBJECT) && rhsType.equals(Type.OBJECT)) {
            return;
        }
        String lhs = SignatureConverter.convert(lhsType.getSignature());
        String rhs = SignatureConverter.convert(rhsType.getSignature());

        if (Values.DOTTED_JAVA_LANG_STRING.equals(lhs) || Values.DOTTED_JAVA_LANG_STRING.equals(rhs)) {
            handleStringComparison(jclass, method, methodGen, visitor, stringComparisonList, location, lhsType, rhsType);
        } else if (suspiciousSet.contains(lhs)) {
            handleSuspiciousRefComparison(jclass, method, methodGen, refComparisonList, location, lhs,
                    (ReferenceType) lhsType, (ReferenceType) rhsType);
        } else if (suspiciousSet.contains(rhs)) {
            handleSuspiciousRefComparison(jclass, method, methodGen, refComparisonList, location, rhs,
                    (ReferenceType) lhsType, (ReferenceType) rhsType);
        }
    }
}
 

/**
 * Determine whether or not the the given method is a getter method. I.e.,
 * if it just returns the value of an instance field.
 *
 * @param classContext
 *            the ClassContext for the class containing the method
 * @param method
 *            the method
 */
public static boolean isGetterMethod(ClassContext classContext, Method method) {
    MethodGen methodGen = classContext.getMethodGen(method);
    if (methodGen == null) {
        return false;
    }
    InstructionList il = methodGen.getInstructionList();
    // System.out.println("Checking getter method: " + method.getName());
    if (il.getLength() > 60) {
        return false;
    }

    int count = 0;
    for (InstructionHandle ih : il) {
        switch (ih.getInstruction().getOpcode()) {
        case Const.GETFIELD:
            count++;
            if (count > 1) {
                return false;
            }
            break;
        case Const.PUTFIELD:
        case Const.BALOAD:
        case Const.CALOAD:
        case Const.DALOAD:
        case Const.FALOAD:
        case Const.IALOAD:
        case Const.LALOAD:
        case Const.SALOAD:
        case Const.AALOAD:
        case Const.BASTORE:
        case Const.CASTORE:
        case Const.DASTORE:
        case Const.FASTORE:
        case Const.IASTORE:
        case Const.LASTORE:
        case Const.SASTORE:
        case Const.AASTORE:
        case Const.PUTSTATIC:
            return false;
        case Const.INVOKESTATIC:
        case Const.INVOKEVIRTUAL:
        case Const.INVOKEINTERFACE:
        case Const.INVOKESPECIAL:
        case Const.GETSTATIC:
            // no-op

        }
    }
    // System.out.println("Found getter method: " + method.getName());
    return true;
}
 

public MethodDescriptor(InvokeInstruction iins, ConstantPoolGen cpg) {
    super(ClassName.toSlashedClassName(iins.getClassName(cpg)), iins.getMethodName(cpg), iins.getSignature(cpg), iins instanceof INVOKESTATIC);
}
 

@Override
public void visitINVOKESTATIC(INVOKESTATIC inv) {
    handleInvoke(inv);
}
 

public static @CheckForNull JavaClassAndMethod findInvocationLeastUpperBound(InvokeInstruction inv, ConstantPoolGen cpg,
        JavaClassAndMethodChooser methodChooser) throws ClassNotFoundException {

    if (DEBUG_METHOD_LOOKUP) {
        System.out.println("Find prototype method for " + SignatureConverter.convertMethodSignature(inv, cpg));
    }

    short opcode = inv.getOpcode();

    if (opcode == Const.INVOKESTATIC) {
        if (methodChooser == INSTANCE_METHOD) {
            return null;
        }
    } else {
        if (methodChooser == STATIC_METHOD) {
            return null;
        }
    }

    // Find the method
    if (opcode == Const.INVOKESPECIAL) {
        // Non-virtual dispatch
        return findExactMethod(inv, cpg, methodChooser);
    }
    if (opcode == Const.INVOKEDYNAMIC) {
        return null;
    }
    String className = inv.getClassName(cpg);
    String methodName = inv.getName(cpg);
    String methodSig = inv.getSignature(cpg);
    if (DEBUG_METHOD_LOOKUP) {
        System.out.println("[Class name is " + className + "]");
        System.out.println("[Method name is " + methodName + "]");
        System.out.println("[Method signature is " + methodSig + "]");
    }

    if (className.startsWith(Values.SIG_ARRAY_PREFIX)) {
        // Java 1.5 allows array classes to appear as the class name
        className = Values.DOTTED_JAVA_LANG_OBJECT;
    }

    JavaClass jClass = Repository.lookupClass(className);
    return findInvocationLeastUpperBound(jClass, methodName, methodSig, methodChooser,
            opcode == Const.INVOKEINTERFACE);
}
 

/**
 * Resolve possible method call targets. This works for both static and
 * instance method calls.
 *
 * @param invokeInstruction
 *            the InvokeInstruction
 * @param typeFrame
 *            the TypeFrame containing the types of stack values
 * @param cpg
 *            the ConstantPoolGen
 * @return Set of methods which might be called
 * @throws DataflowAnalysisException
 * @throws ClassNotFoundException
 */
public static Set<JavaClassAndMethod> resolveMethodCallTargets(InvokeInstruction invokeInstruction, TypeFrame typeFrame,
        ConstantPoolGen cpg) throws DataflowAnalysisException, ClassNotFoundException {

    short opcode = invokeInstruction.getOpcode();

    if (opcode == Const.INVOKESTATIC) {
        HashSet<JavaClassAndMethod> result = new HashSet<>();
        JavaClassAndMethod targetMethod = findInvocationLeastUpperBound(invokeInstruction, cpg, CONCRETE_METHOD);
        if (targetMethod != null) {
            result.add(targetMethod);
        }
        return result;
    }

    if (!typeFrame.isValid()) {
        return new HashSet<>();
    }

    Type receiverType;
    boolean receiverTypeIsExact;

    if (opcode == Const.INVOKESPECIAL) {
        // invokespecial instructions are dispatched to EXACTLY
        // the class specified by the instruction
        receiverType = ObjectTypeFactory.getInstance(invokeInstruction.getClassName(cpg));
        receiverTypeIsExact = false; // Doesn't actually matter
    } else if (opcode == Const.INVOKEDYNAMIC) {
        // XXX handle INVOKEDYNAMIC
        return new HashSet<>();
    } else {
        // For invokevirtual and invokeinterface instructions, we have
        // virtual dispatch. By taking the receiver type (which may be a
        // subtype of the class specified by the instruction),
        // we may get a more precise set of call targets.
        int instanceStackLocation = typeFrame.getInstanceStackLocation(invokeInstruction, cpg);
        receiverType = typeFrame.getStackValue(instanceStackLocation);
        if (!(receiverType instanceof ReferenceType)) {
            return new HashSet<>();
        }
        receiverTypeIsExact = typeFrame.isExact(instanceStackLocation);
    }
    if (DEBUG_METHOD_LOOKUP) {
        System.out.println("[receiver type is " + receiverType + ", " + (receiverTypeIsExact ? "exact]" : " not exact]"));
    }

    return resolveMethodCallTargets((ReferenceType) receiverType, invokeInstruction, cpg, receiverTypeIsExact);
}
 

/**
 * Resolve possible instance method call targets.
 *
 * @param receiverType
 *            type of the receiver object
 * @param invokeInstruction
 *            the InvokeInstruction
 * @param cpg
 *            the ConstantPoolGen
 * @param receiverTypeIsExact
 *            if true, the receiver type is known exactly, which should
 *            allow a precise result
 * @return Set of methods which might be called
 * @throws ClassNotFoundException
 */
public static Set<JavaClassAndMethod> resolveMethodCallTargets(ReferenceType receiverType,
        InvokeInstruction invokeInstruction, ConstantPoolGen cpg, boolean receiverTypeIsExact) throws ClassNotFoundException {
    HashSet<JavaClassAndMethod> result = new HashSet<>();

    if (invokeInstruction.getOpcode() == Const.INVOKESTATIC) {
        throw new IllegalArgumentException();
    }

    String methodName = invokeInstruction.getName(cpg);
    String methodSig = invokeInstruction.getSignature(cpg);

    // Array method calls aren't virtual.
    // They should just resolve to Object methods.
    if (receiverType instanceof ArrayType) {
        JavaClass javaLangObject = AnalysisContext.currentAnalysisContext().lookupClass(Values.DOTTED_JAVA_LANG_OBJECT);
        JavaClassAndMethod classAndMethod = findMethod(javaLangObject, methodName, methodSig, INSTANCE_METHOD);
        if (classAndMethod != null) {
            result.add(classAndMethod);
        }
        return result;
    }

    if (receiverType instanceof NullType) {
        return Collections.<JavaClassAndMethod>emptySet();
    }
    AnalysisContext analysisContext = AnalysisContext.currentAnalysisContext();

    // Get the receiver class.
    String receiverClassName = ((ObjectType) receiverType).getClassName();
    JavaClass receiverClass = analysisContext.lookupClass(receiverClassName);
    ClassDescriptor receiverDesc = DescriptorFactory.createClassDescriptorFromDottedClassName(receiverClassName);

    // Figure out the upper bound for the method.
    // This is what will be called if this is not a virtual call site.
    JavaClassAndMethod upperBound = findMethod(receiverClass, methodName, methodSig, CONCRETE_METHOD);
    if (upperBound == null) {
        upperBound = findInvocationLeastUpperBound(receiverClass, methodName, methodSig, CONCRETE_METHOD, false);
    }
    if (upperBound != null) {
        if (DEBUG_METHOD_LOOKUP) {
            System.out.println("Adding upper bound: "
                    + SignatureConverter.convertMethodSignature(upperBound.getJavaClass(), upperBound.getMethod()));
        }
        result.add(upperBound);
    }

    // Is this a virtual call site?
    boolean virtualCall = (invokeInstruction.getOpcode() == Const.INVOKEVIRTUAL || invokeInstruction.getOpcode() == Const.INVOKEINTERFACE)
            && (upperBound == null || !upperBound.getJavaClass().isFinal() && !upperBound.getMethod().isFinal())
            && !receiverTypeIsExact;

    if (virtualCall) {
        if (!Values.DOTTED_JAVA_LANG_OBJECT.equals(receiverClassName)) {

            // This is a true virtual call: assume that any concrete
            // subtype method may be called.
            Set<ClassDescriptor> subTypeSet = analysisContext.getSubtypes2().getSubtypes(receiverDesc);
            for (ClassDescriptor subtype : subTypeSet) {
                XMethod concreteSubtypeMethod = findMethod(subtype, methodName, methodSig, false);
                if (concreteSubtypeMethod != null && (concreteSubtypeMethod.getAccessFlags() & Const.ACC_ABSTRACT) == 0) {
                    result.add(new JavaClassAndMethod(concreteSubtypeMethod));
                }
            }
            if (false && subTypeSet.size() > 500) {
                new RuntimeException(receiverClassName + " has " + subTypeSet.size() + " subclasses, " + result.size()
                        + " of which implement " + methodName + methodSig + " " + invokeInstruction)
                                .printStackTrace(System.out);
            }

        }
    }
    return result;
}
 

public static @CheckForNull XMethod findInvocationLeastUpperBound(InvokeInstruction inv, ConstantPoolGen cpg,
        JavaClassAndMethodChooser methodChooser) {

    if (DEBUG_METHOD_LOOKUP) {
        System.out.println("Find prototype method for " + SignatureConverter.convertMethodSignature(inv, cpg));
    }

    short opcode = inv.getOpcode();

    if (opcode == Const.INVOKESTATIC) {
        if (methodChooser == INSTANCE_METHOD) {
            return null;
        }
    } else {
        if (methodChooser == STATIC_METHOD) {
            return null;
        }
    }

    // Find the method
    if (opcode == Const.INVOKESPECIAL) {
        // Non-virtual dispatch
        return findExactMethod(inv, cpg, methodChooser);
    } else {
        String className = inv.getClassName(cpg);
        String methodName = inv.getName(cpg);
        String methodSig = inv.getSignature(cpg);
        if (DEBUG_METHOD_LOOKUP) {
            System.out.println("[Class name is " + className + "]");
            System.out.println("[Method name is " + methodName + "]");
            System.out.println("[Method signature is " + methodSig + "]");
        }

        if (className.startsWith(Values.SIG_ARRAY_PREFIX)) {
            // Java 1.5 allows array classes to appear as the class name
            className = Values.DOTTED_JAVA_LANG_OBJECT;
        }

        try {
            return thisOrNothing(
                    findInvocationLeastUpperBound(getXClassFromDottedClassName(className), methodName, methodSig,
                            opcode == Const.INVOKESTATIC, opcode == Const.INVOKEINTERFACE), methodChooser);
        } catch (CheckedAnalysisException e) {
            return null;
        }

    }
}
 

/**
 * Resolve possible method call targets. This works for both static and
 * instance method calls.
 *
 * @param invokeInstruction
 *            the InvokeInstruction
 * @param typeFrame
 *            the TypeFrame containing the types of stack values
 * @param cpg
 *            the ConstantPoolGen
 * @return Set of methods which might be called
 * @throws DataflowAnalysisException
 * @throws ClassNotFoundException
 */
public static @Nonnull Set<XMethod> resolveMethodCallTargets(InvokeInstruction invokeInstruction, TypeFrame typeFrame, ConstantPoolGen cpg)
        throws DataflowAnalysisException, ClassNotFoundException {

    short opcode = invokeInstruction.getOpcode();

    if (opcode == Const.INVOKESTATIC) {
        return Util.emptyOrNonnullSingleton(findInvocationLeastUpperBound(invokeInstruction, cpg, STATIC_METHOD));
    }

    if (!typeFrame.isValid()) {
        return Collections.<XMethod>emptySet();
    }

    // XXX handle INVOKEDYNAMIC
    if (opcode == Const.INVOKEDYNAMIC) {
        return Collections.<XMethod>emptySet();
    }

    Type receiverType;
    boolean receiverTypeIsExact;

    if (opcode == Const.INVOKESPECIAL) {
        // invokespecial instructions are dispatched to EXACTLY
        // the class specified by the instruction
        receiverType = ObjectTypeFactory.getInstance(invokeInstruction.getClassName(cpg));
        receiverTypeIsExact = false; // Doesn't actually matter
    } else {
        // For invokevirtual and invokeinterface instructions, we have
        // virtual dispatch. By taking the receiver type (which may be a
        // subtype of the class specified by the instruction),
        // we may get a more precise set of call targets.
        int instanceStackLocation = typeFrame.getInstanceStackLocation(invokeInstruction, cpg);
        receiverType = typeFrame.getStackValue(instanceStackLocation);
        if (!(receiverType instanceof ReferenceType)) {
            return Collections.<XMethod>emptySet();
        }
        receiverTypeIsExact = typeFrame.isExact(instanceStackLocation);
    }
    if (DEBUG_METHOD_LOOKUP) {
        System.out.println("[receiver type is " + receiverType + ", " + (receiverTypeIsExact ? "exact]" : " not exact]"));
    }

    return resolveMethodCallTargets((ReferenceType) receiverType, invokeInstruction, cpg, receiverTypeIsExact);
}
 

@Override
public void visitINVOKESTATIC(INVOKESTATIC obj) {
    handleInvoke(obj);
}
 

/** @see org.apache.bcel.generic.Visitor */
public void visitINVOKESTATIC(INVOKESTATIC aINVOKESTATIC)
{
    addInvokeReference(
        new InvokeReference(aINVOKESTATIC, mCurrentPoolGen));
}
 

/** @see org.apache.bcel.generic.Visitor */
public void visitINVOKESTATIC(INVOKESTATIC aINVOKESTATIC)
{
    addInvokeReference(
        new InvokeReference(aINVOKESTATIC, mCurrentPoolGen));
}
 

/**
   * Fifth pass, produce Java byte code.
   */
  @Override
  public void byte_code(final InstructionList il, final MethodGen method, final ConstantPoolGen cp) {
    final String     fname = name.getName();
//    Function   f     = function;
    //ASTIdent   fun   = f.getName();
//    ASTIdent[] args  = f.getArgs();
    final String     class_name = method.getClassName();

    if(fname.equals("READ")) {
        il.append(new INVOKESTATIC(cp.addMethodref(class_name,
                                                 "_readInt",
                                                 "()I")));
    } else if(fname.equals("WRITE")) {
      exprs[0].byte_code(il, method, cp);
      ASTFunDecl.pop();
      il.append(new INVOKESTATIC(cp.addMethodref(class_name,
                                                 "_writeInt",
                                                 "(I)I")));
    }
    else { // Normal function
      final int size    = exprs.length;
      Type[] argv = null;

      if(exprs != null) {
        argv = new Type[size];

        for(int i=0; i < size; i++) {
          argv[i] = Type.INT;
          exprs[i].byte_code(il, method, cp);
        }

        //ASTFunDecl.push(size);
      }

      ASTFunDecl.pop(size);

      // Function call
      il.append(new INVOKESTATIC(cp.addMethodref(class_name,
                                                 fname,
                                                 Type.getMethodSignature(Type.INT,
                                                                         argv))));
    }

    ASTFunDecl.push();
  }
 

/**
 * Get the inner class access object for given invokestatic instruction.
 * Returns null if the called method is not an inner class access.
 *
 * @param inv
 *            the invokestatic instruction
 * @param cpg
 *            the ConstantPoolGen for the method
 * @return the InnerClassAccess, or null if the call is not an inner class
 *         access
 */
public InnerClassAccess getInnerClassAccess(INVOKESTATIC inv, ConstantPoolGen cpg) throws ClassNotFoundException {
    String methodName = inv.getMethodName(cpg);
    if (methodName.startsWith("access$")) {
        String className = inv.getClassName(cpg);

        return getInnerClassAccess(className, methodName);
    }
    return null;
}