/*
* FindBugs - Find bugs in Java programs
* Copyright (C) 2004,2005 University of Maryland
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
package edu.umd.cs.findbugs.detect;
import java.util.BitSet;
import java.util.Iterator;
import org.apache.bcel.Constants;
import org.apache.bcel.classfile.JavaClass;
import org.apache.bcel.classfile.Method;
import org.apache.bcel.generic.ConstantPoolGen;
import org.apache.bcel.generic.INVOKEVIRTUAL;
import org.apache.bcel.generic.Instruction;
import org.apache.bcel.generic.InstructionHandle;
import org.apache.bcel.generic.ObjectType;
import org.apache.bcel.generic.ReferenceType;
import org.apache.bcel.generic.Type;
import edu.umd.cs.findbugs.BugInstance;
import edu.umd.cs.findbugs.BugReporter;
import edu.umd.cs.findbugs.Detector;
import edu.umd.cs.findbugs.Lookup;
import edu.umd.cs.findbugs.MethodAnnotation;
import edu.umd.cs.findbugs.StatelessDetector;
import edu.umd.cs.findbugs.TypeAnnotation;
import edu.umd.cs.findbugs.ba.AnalysisContext;
import edu.umd.cs.findbugs.ba.CFG;
import edu.umd.cs.findbugs.ba.CFGBuilderException;
import edu.umd.cs.findbugs.ba.ClassContext;
import edu.umd.cs.findbugs.ba.Hierarchy;
import edu.umd.cs.findbugs.ba.Location;
import edu.umd.cs.findbugs.ba.ObjectTypeFactory;
import edu.umd.cs.findbugs.ba.XClass;
import edu.umd.cs.findbugs.ba.XMethod;
import edu.umd.cs.findbugs.ba.type.TypeDataflow;
import edu.umd.cs.findbugs.ba.type.TypeFrame;
import edu.umd.cs.findbugs.classfile.CheckedAnalysisException;
import edu.umd.cs.findbugs.classfile.ClassDescriptor;
import edu.umd.cs.findbugs.classfile.DescriptorFactory;
/**
* Find places where ordinary (balanced) synchronization is performed on JSR166
* Lock objects. Suggested by Doug Lea.
*
* @author David Hovemeyer
*/
public final class FindJSR166LockMonitorenter implements Detector, StatelessDetector {
/**
*
*/
private static final String UTIL_CONCURRRENT_SIG_PREFIX = "Ljava/util/concurrent/";
private final BugReporter bugReporter;
private static final ObjectType LOCK_TYPE = ObjectTypeFactory.getInstance("java.util.concurrent.locks.Lock");
public FindJSR166LockMonitorenter(BugReporter bugReporter) {
this.bugReporter = bugReporter;
}
@Override
public Object clone() {
try {
return super.clone();
} catch (CloneNotSupportedException e) {
throw new AssertionError(e);
}
}
@Override
public void visitClassContext(ClassContext classContext) {
JavaClass jclass = classContext.getJavaClass();
if (jclass.getClassName().startsWith("java.util.concurrent.")) {
return;
}
Method[] methodList = jclass.getMethods();
for (Method method : methodList) {
if (method.getCode() == null) {
continue;
}
// We can ignore methods that don't contain a monitorenter
BitSet bytecodeSet = classContext.getBytecodeSet(method);
if (bytecodeSet == null) {
continue;
}
if (false && !bytecodeSet.get(Constants.MONITORENTER)) {
continue;
}
analyzeMethod(classContext, method);
}
}
private void analyzeMethod(ClassContext classContext, Method method) {
ConstantPoolGen cpg = classContext.getConstantPoolGen();
CFG cfg;
try {
cfg = classContext.getCFG(method);
} catch (CFGBuilderException e1) {
AnalysisContext.logError("Coult not get CFG", e1);
return;
}
TypeDataflow typeDataflow;
try {
typeDataflow = classContext.getTypeDataflow(method);
} catch (CheckedAnalysisException e1) {
AnalysisContext.logError("Coult not get Type dataflow", e1);
return;
}
for (Iterator<Location> i = cfg.locationIterator(); i.hasNext();) {
Location location = i.next();
InstructionHandle handle = location.getHandle();
Instruction ins = handle.getInstruction();
if (ins.getOpcode() == Constants.INVOKEVIRTUAL) {
INVOKEVIRTUAL iv = (INVOKEVIRTUAL) ins;
String methodName = iv.getMethodName(cpg);
String methodSig = iv.getSignature(cpg);
if (methodName.equals("wait")
&& (methodSig.equals("()V") || methodSig.equals("(J)V") || methodSig.equals("(JI)V"))
|| (methodName.equals("notify") || methodName.equals("notifyAll")) && methodSig.equals("()V")) {
try {
TypeFrame frame = typeDataflow.getFactAtLocation(location);
if (!frame.isValid()) {
continue;
}
Type type = frame.getInstance(ins, cpg);
if (!(type instanceof ReferenceType)) {
// Something is deeply wrong if a non-reference type
// is used for a method invocation. But, that's
// really a
// verification problem.
continue;
}
ClassDescriptor classDescriptor = DescriptorFactory.createClassDescriptorFromSignature(type
.getSignature());
if (classDescriptor.equals(classContext.getClassDescriptor())) {
continue;
}
if (!classDescriptor.getClassName().startsWith("java/util/concurrent")) {
continue;
}
XClass c = Lookup.getXClass(classDescriptor);
XMethod m;
int priority = NORMAL_PRIORITY;
if (methodName.equals("wait")) {
m = c.findMethod("await", "()V", false);
priority = HIGH_PRIORITY;
} else if (methodName.equals("notify")) {
m = c.findMethod("signal", "()V", false);
if (m == null) {
m = c.findMethod("countDown", "()V", false);
}
} else if (methodName.equals("notifyAll")) {
m = c.findMethod("signalAll", "()V", false);
if (m == null) {
m = c.findMethod("countDown", "()V", false);
}
} else {
throw new IllegalStateException("Unexpected methodName: " + methodName);
}
if (m != null && m.isPublic() && c.isPublic()) {
bugReporter.reportBug(new BugInstance(this, "JML_JSR166_CALLING_WAIT_RATHER_THAN_AWAIT", priority)
.addClassAndMethod(classContext.getJavaClass(), method).addCalledMethod(cpg, iv).addMethod(m)
.describe(MethodAnnotation.METHOD_ALTERNATIVE_TARGET).addType(classDescriptor)
.describe(TypeAnnotation.FOUND_ROLE).addSourceLine(classContext, method, location));
}
} catch (CheckedAnalysisException e) {
AnalysisContext.logError("Coult not get Type dataflow", e);
continue;
}
}
}
if (ins.getOpcode() != Constants.MONITORENTER) {
continue;
}
Type type;
try {
TypeFrame frame = typeDataflow.getFactAtLocation(location);
if (!frame.isValid()) {
continue;
}
type = frame.getInstance(ins, cpg);
} catch (CheckedAnalysisException e) {
AnalysisContext.logError("Coult not get Type dataflow", e);
continue;
}
if (!(type instanceof ReferenceType)) {
// Something is deeply wrong if a non-reference type
// is used for a monitorenter. But, that's really a
// verification problem.
continue;
}
boolean isSubtype = false;
try {
isSubtype = Hierarchy.isSubtype((ReferenceType) type, LOCK_TYPE);
} catch (ClassNotFoundException e) {
bugReporter.reportMissingClass(e);
}
String sig = type.getSignature();
boolean isUtilConcurrentSig = sig.startsWith(UTIL_CONCURRRENT_SIG_PREFIX);
if (isSubtype) {
bugReporter.reportBug(new BugInstance(this, "JLM_JSR166_LOCK_MONITORENTER", isUtilConcurrentSig ? HIGH_PRIORITY
: NORMAL_PRIORITY).addClassAndMethod(classContext.getJavaClass(), method).addType(sig)
.addSourceForTopStackValue(classContext, method, location).addSourceLine(classContext, method, location));
} else if (isUtilConcurrentSig) {
int priority = "Ljava/util/concurrent/CopyOnWriteArrayList;".equals(sig) ? HIGH_PRIORITY : NORMAL_PRIORITY;
bugReporter.reportBug(new BugInstance(this, "JLM_JSR166_UTILCONCURRENT_MONITORENTER", priority)
.addClassAndMethod(classContext.getJavaClass(), method).addType(sig)
.addSourceForTopStackValue(classContext, method, location).addSourceLine(classContext, method, location));
}
}
}
@Override
public void report() {
}
}