/*
* FindBugs - Find Bugs in Java programs
* Copyright (C) 2003-2007 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 edu.umd.cs.findbugs.BugAccumulator;
import edu.umd.cs.findbugs.BugInstance;
import edu.umd.cs.findbugs.BugReporter;
import edu.umd.cs.findbugs.ba.SignatureParser;
import edu.umd.cs.findbugs.bcel.OpcodeStackDetector;
import org.apache.bcel.classfile.Code;
/**
* @author alison
*/
public class BooleanReturnNull extends OpcodeStackDetector {
BugAccumulator bugAccumulator;
public BooleanReturnNull(BugReporter bugReporter) {
this.bugAccumulator = new BugAccumulator(bugReporter);
}
@Override
public void visit(Code code) {
String s = getMethodSig();
SignatureParser sp = new SignatureParser(s);
//Check to see if the method has Boolean return type
boolean interesting = "Ljava/lang/Boolean;".equals(sp.getReturnTypeSignature());
if (interesting) {
super.visit(code); // make callbacks to sawOpcode for all opcodes
bugAccumulator.reportAccumulatedBugs();
}
}
/* (non-Javadoc)
* @see edu.umd.cs.findbugs.bcel.OpcodeStackDetector#sawOpcode(int)
*/
@Override
public void sawOpcode(int seen) {
if (seen == ARETURN && getPrevOpcode(1) == ACONST_NULL)
bugAccumulator.accumulateBug(new BugInstance(this, "NP_BOOLEAN_RETURN_NULL", NORMAL_PRIORITY)
.addClassAndMethod(this), this);
}
}