/*
* 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 org.apache.bcel.classfile.Code;
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;
// 2: astore_1
// 3: monitorenter
// 4: aload_0
// 5: invokevirtual #13; //Method java/lang/Object.notify:()V
// 8: aload_1
// 9: monitorexit
public class FindNakedNotify extends BytecodeScanningDetector implements StatelessDetector {
int stage = 0;
private final BugReporter bugReporter;
boolean synchronizedMethod;
private int notifyPC;
public FindNakedNotify(BugReporter bugReporter) {
this.bugReporter = bugReporter;
}
@Override
public void visit(Method obj) {
int flags = obj.getAccessFlags();
synchronizedMethod = (flags & ACC_SYNCHRONIZED) != 0;
}
@Override
public void visit(Code obj) {
stage = synchronizedMethod ? 1 : 0;
super.visit(obj);
if (synchronizedMethod && stage == 4) {
bugReporter.reportBug(new BugInstance(this, "NN_NAKED_NOTIFY", NORMAL_PRIORITY).addClassAndMethod(this)
.addSourceLine(this, notifyPC));
}
}
@Override
public void sawOpcode(int seen) {
switch (stage) {
case 0:
if (seen == MONITORENTER) {
stage = 1;
}
break;
case 1:
stage = 2;
break;
case 2:
if (seen == INVOKEVIRTUAL
&& (getNameConstantOperand().equals("notify") || getNameConstantOperand().equals("notifyAll"))
&& getSigConstantOperand().equals("()V")) {
stage = 3;
notifyPC = getPC();
} else {
stage = 0;
}
break;
case 3:
stage = 4;
break;
case 4:
if (seen == MONITOREXIT) {
bugReporter.reportBug(new BugInstance(this, "NN_NAKED_NOTIFY", NORMAL_PRIORITY).addClassAndMethod(this)
.addSourceLine(this, notifyPC));
stage = 5;
} else {
stage = 0;
}
break;
case 5:
break;
default:
assert false;
}
}
}