fb-contrib-commit

[Dave B. <dbr...@us...>]

Update of /cvsroot/fb-contrib/fb-contrib/src/com/mebigfatguy/fbcontrib/detect
In directory sc8-pr-cvs1.sourceforge.net:/tmp/cvs-serv3152/src/com/mebigfatguy/fbcontrib/detect

Added Files:
	CopiedOverriddenMethod.java 
Log Message:
initial check in - new COM detector

--- NEW FILE: CopiedOverriddenMethod.java ---
/*
 * fb-contrib - Auxilliary detectors for Java programs
 * Copyright (C) 2005 Dave Brosius
 * 
 * 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 com.mebigfatguy.fbcontrib.detect;

import java.util.Arrays;
import java.util.HashMap;
import java.util.Map;

import org.apache.bcel.classfile.Code;
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.Detector;
import edu.umd.cs.findbugs.SourceLineAnnotation;
import edu.umd.cs.findbugs.StatelessDetector;
import edu.umd.cs.findbugs.ba.ClassContext;
import edu.umd.cs.findbugs.visitclass.DismantleBytecode;

public class CopiedOverriddenMethod extends DismantleBytecode implements Detector, StatelessDetector
{
	private BugReporter bugReporter;
	private Map<String, Code> superclassCode = new HashMap<String, Code>();
	private ClassContext classContext;
	private String curMethodInfo;
	
    /**
     * constructs a COM detector given the reporter to report bugs on

     * @param bugReporter the sync of bug reports
     */
	public CopiedOverriddenMethod(BugReporter bugReporter) {
		this.bugReporter = bugReporter;
	}
	
	/**
	 * clone this detector so that it can be a StatelessDetector
	 * 
	 * @return a clone of this object
	 */
	@Override
	public Object clone() throws CloneNotSupportedException {
		return super.clone();
	}	
	
	/**
	 * overrides the visitor to accept classes derived from non java.lang.Object classes.
	 * 
	 * @param classContext the context object of the currently parsed class
	 */
	public void visitClassContext(ClassContext classContext) {
		try {
			JavaClass cls = classContext.getJavaClass();
			String superName = cls.getSuperclassName();
			if (!"java.lang.Object".equals(superName)) {
				this.classContext = classContext;
				superclassCode.clear();
				JavaClass superCls = cls.getSuperClass();
				Method[] methods = superCls.getMethods();
				for (Method m : methods) {
					String methodName = m.getName();
					if ((m.isPublic() ||  m.isProtected())
					&&  (!"<init>".equals(methodName) && !"<clinit>".equals(methodName))) {
						String methodInfo = methodName + ":" + m.getSignature();
						superclassCode.put(methodInfo, m.getCode());
					}
				}
				cls.accept(this);
				superclassCode.clear();
			}
		} catch (ClassNotFoundException cnfe) {
			bugReporter.reportMissingClass(cnfe);
		}
	}
	
	/**
	 * overrides the visitor to get the methodInfo
	 * 
	 * @param obj the method object for the currently parsed method
	 */
	public void visitMethod(Method obj) {
		curMethodInfo = obj.getName() + ":" + obj.getSignature();
	}
	
	/**
	 * overrides the visitor to find code blocks of methods that are the same as its parents
	 * 
	 * @param obj the code object of the currently parsed method
	 */
	public void visitCode(Code obj) {
		Method m = getMethod();
		if (!m.isPublic() && !m.isProtected())
			return;
		
		Code superCode = superclassCode.get(curMethodInfo);
		if (superCode != null) {
			if (Arrays.equals(obj.getCode(), superCode.getCode())) {
				bugReporter.reportBug(new BugInstance(this, "COM_COPIED_OVERRIDDEN_METHOD", NORMAL_PRIORITY)
					.addClass(this)
					.addMethod(this)
					.addSourceLine(classContext, this, getPC()));
			}
		}
	}
	
	/**
	 * implements the detector with an empty implementation
	 */
	public void report() {
	}
}