/*
* FindBugs - Find bugs in Java programs
* Copyright (C) 2003-2005 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.HashSet;
import java.util.Set;
import org.apache.bcel.classfile.Field;
import org.apache.bcel.classfile.JavaClass;
import org.apache.bcel.classfile.Method;
import edu.umd.cs.findbugs.BugInstance;
import edu.umd.cs.findbugs.BugReporter;
import edu.umd.cs.findbugs.BytecodeScanningDetector;
import edu.umd.cs.findbugs.StatelessDetector;
public class MutableLock extends BytecodeScanningDetector implements StatelessDetector {
Set<String> setFields = new HashSet<String>();
Set<String> finalFields = new HashSet<String>();
boolean thisOnTOS = false;
private final BugReporter bugReporter;
public MutableLock(BugReporter bugReporter) {
this.bugReporter = bugReporter;
}
@Override
public void visit(JavaClass obj) {
finalFields.clear();
super.visit(obj);
}
@Override
public void visit(Field obj) {
super.visit(obj);
if (obj.isFinal()) {
finalFields.add(obj.getName());
}
}
@Override
public void visit(Method obj) {
super.visit(obj);
setFields.clear();
thisOnTOS = false;
}
@Override
public void sawOpcode(int seen) {
switch (seen) {
case ALOAD_0:
thisOnTOS = true;
return;
case MONITOREXIT:
setFields.clear();
break;
case PUTFIELD:
if (getClassConstantOperand().equals(getClassName())) {
setFields.add(getNameConstantOperand());
}
break;
case GETFIELD:
if (thisOnTOS && getClassConstantOperand().equals(getClassName()) && setFields.contains(getNameConstantOperand())
&& asUnsignedByte(codeBytes[getPC() + 3]) == DUP && asUnsignedByte(codeBytes[getPC() + 5]) == MONITORENTER
&& !finalFields.contains(getNameConstantOperand())) {
bugReporter.reportBug(new BugInstance(this, "ML_SYNC_ON_UPDATED_FIELD", NORMAL_PRIORITY).addClassAndMethod(this)
.addReferencedField(this).addSourceLine(this, getPC() + 5));
}
break;
default:
break;
}
thisOnTOS = false;
}
}