package edu.umd.cs.findbugs;
import java.util.Set;
import org.apache.bcel.Repository;
import org.apache.bcel.classfile.JavaClass;
import edu.umd.cs.findbugs.ba.AnalysisContext;
import edu.umd.cs.findbugs.ba.ch.Subtypes2;
import edu.umd.cs.findbugs.classfile.ClassDescriptor;
import edu.umd.cs.findbugs.classfile.DescriptorFactory;
import edu.umd.cs.findbugs.internalAnnotations.DottedClassName;
public class DeepSubtypeAnalysis {
static private JavaClass serializable;
static private JavaClass collection;
static private JavaClass comparator;
static private JavaClass map;
static private JavaClass remote;
static private ClassNotFoundException storedException;
private static final boolean DEBUG = SystemProperties.getBoolean("dsa.debug");
static {
try {
serializable = AnalysisContext.lookupSystemClass("java.io.Serializable");
collection = AnalysisContext.lookupSystemClass("java.util.Collection");
map = AnalysisContext.lookupSystemClass("java.util.Map");
comparator = AnalysisContext.lookupSystemClass("java.util.Comparator");
} catch (ClassNotFoundException e) {
storedException = e;
}
try {
remote = AnalysisContext.lookupSystemClass("java.rmi.Remote");
} catch (ClassNotFoundException e) {
if (storedException == null) storedException = e;
}
}
private static boolean containsConcreteClasses(Set<JavaClass> s) {
for (JavaClass c : s)
if (!c.isInterface() && !c.isAbstract())
return true;
return false;
}
public static double isDeepSerializable(@DottedClassName String refSig)
throws ClassNotFoundException {
if (storedException != null)
throw storedException;
if (isPrimitiveComponentClass(refSig)) {
if(DEBUG) {
System.out.println("regSig \"" + refSig + "\" is primitive component class");
}
return 1.0;
}
String refName = getComponentClass(refSig);
if (refName.equals("java.lang.Object"))
return 0.99;
JavaClass refJavaClass = Repository.lookupClass(refName);
return isDeepSerializable(refJavaClass);
}
public static double isDeepRemote(String refSig) {
if (remote == null) return 0.1;
String refName = getComponentClass(refSig);
if (refName.equals("java.lang.Object"))
return 0.99;
JavaClass refJavaClass;
try {
refJavaClass = Repository.lookupClass(refName);
return Analyze.deepInstanceOf(refJavaClass, remote);
} catch (ClassNotFoundException e) {
return 0.99;
}
}
private static boolean isPrimitiveComponentClass(String refSig) {
int c = 0;
while (c < refSig.length() && refSig.charAt(c) == '[') {
c++;
}
// If the string is now empty, then we evidently have
// an invalid type signature. We'll return "true",
// which in turn will cause isDeepSerializable() to return
// 1.0, hopefully avoiding any warnings from being generated
// by whatever detector is calling us.
return c >= refSig.length() || refSig.charAt(c) != 'L';
}
public static String getComponentClass(String refSig) {
while (refSig.charAt(0) == '[')
refSig = refSig.substring(1);
//TODO: This method now returns primitive type signatures, is this ok?
if (refSig.charAt(0) == 'L')
return refSig.substring(1, refSig.length() - 1).replace('/', '.');
return refSig;
}
public static double isDeepSerializable(JavaClass x)
throws ClassNotFoundException {
if (storedException != null)
throw storedException;
if (x.getClassName().equals("java.lang.Object"))
return 0.4;
double result = Analyze.deepInstanceOf(x, serializable);
if (result >= 0.9) {
if(DEBUG) {
System.out.println("High serializable result: " + result);
}
return result;
}
if (x.isFinal()) return result;
ClassDescriptor classDescriptor = DescriptorFactory.createClassDescriptor(x);
Subtypes2 subtypes2 = AnalysisContext.currentAnalysisContext().getSubtypes2();
double confidence = 0.6;
Set<ClassDescriptor> directSubtypes = subtypes2.getDirectSubtypes(classDescriptor);
directSubtypes.remove(classDescriptor);
if (x.isAbstract() || x.isInterface()) {
confidence = 0.8;
result = Math.max(result, 0.4);
} else if (directSubtypes.isEmpty())
confidence = 0.2;
for(ClassDescriptor subtype : directSubtypes) {
JavaClass subJavaClass = Repository.lookupClass(subtype.getDottedClassName());
result = Math.max(result, confidence * isDeepSerializable(subJavaClass));
}
if (result >= 0.9) {
return result;
}
result = Math.max(result, confidence * Analyze.deepInstanceOf(x, collection));
if (result >= 0.9) {
if(DEBUG) {
System.out.println("High collection result: " + result);
}
return result;
}
result = Math.max(result, confidence * Analyze.deepInstanceOf(x, map));
if (result >= 0.9) {
if(DEBUG) {
System.out.println("High map result: " + result);
}
return result;
}
result = Math.max(result, confidence * 0.5*Analyze.deepInstanceOf(x, comparator));
if (result >= 0.9) {
if(DEBUG) {
System.out.println("High comparator result: " + result);
}
return result;
}
if(DEBUG) {
System.out.println("No high results; max: " + result);
}
return result;
}
/**
* Given two JavaClasses, try to estimate the probability that an reference
* of type x is also an instance of type y. Will return 0 only if it is
* impossible and 1 only if it is guaranteed.
*
* @param x
* Known type of object
* @param y
* Type queried about
* @return 0 - 1 value indicating probability
*/
public static double deepInstanceOf(@DottedClassName String x, @DottedClassName String y)
throws ClassNotFoundException {
return Analyze.deepInstanceOf(x, y);
}
/**
* Given two JavaClasses, try to estimate the probability that an reference
* of type x is also an instance of type y. Will return 0 only if it is
* impossible and 1 only if it is guaranteed.
*
* @param x
* Known type of object
* @param y
* Type queried about
* @return 0 - 1 value indicating probability
*/
public static double deepInstanceOf(JavaClass x, JavaClass y)
throws ClassNotFoundException {
return Analyze.deepInstanceOf(x, y);
}
}