/*
 * FindBugs - Find bugs in Java programs
 * Copyright (C) 2005 Dave Brosius <dbrosius@users.sourceforge.net>
 * Copyright (C) 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.JavaClass;
import org.apache.bcel.generic.Type;

import edu.umd.cs.findbugs.BugInstance;
import edu.umd.cs.findbugs.BugReporter;
import edu.umd.cs.findbugs.BytecodeScanningDetector;
import edu.umd.cs.findbugs.OpcodeStack;
import edu.umd.cs.findbugs.StatelessDetector;
import edu.umd.cs.findbugs.ba.ClassContext;
import edu.umd.cs.findbugs.visitclass.Constants2;

public class InefficientMemberAccess extends BytecodeScanningDetector implements Constants2, StatelessDetector {
	
	public static final String ACCESS_PREFIX = "access$";
	private BugReporter bugReporter;
	private String clsName;
	
	public InefficientMemberAccess(BugReporter bugReporter) {
		this.bugReporter = bugReporter;
	}

	public Object clone() throws CloneNotSupportedException {
		return super.clone();
	}
	
	public void visitClassContext(ClassContext classContext) {
		JavaClass cls = classContext.getJavaClass();
		clsName = cls.getClassName();
		if (clsName.indexOf("$") >= 0)
			super.visitClassContext(classContext);
	}
	
	public void visit(Code obj) {
		super.visit(obj);
	}
	
	public void sawOpcode(int seen) {
		int varSlot;
		if (seen == INVOKESTATIC) {
			String methodName = getNameConstantOperand();
			if (!methodName.startsWith(ACCESS_PREFIX))
				return;
			try {
				varSlot = Integer.valueOf(methodName.substring(ACCESS_PREFIX.length()));
			}
			catch (NumberFormatException nfe) {
				return;
			}
			String methodSig = getSigConstantOperand();
			Type[] argTypes = Type.getArgumentTypes(methodSig);
			if (argTypes.length != 2)
				return;
			String parCls = argTypes[0].getSignature();
			parCls = parCls.substring(1, parCls.length() - 1);
			if (!parCls.equals(getClassConstantOperand()))
				return;
			if (!argTypes[1].getSignature().equals(Type.getReturnType(methodSig).getSignature()))
				return;
			
			bugReporter.reportBug(new BugInstance(this, "IMA_INEFFICIENT_MEMBER_ACCESS", LOW_PRIORITY)
				.addClassAndMethod(this)
				.addSourceLine(this));
		}
	}
	
	
	

}

@@ -2583,16 +2583,52 @@
 ture();%0A
+%09%09%09if (parCls.length() %3C 3) return;%0A
 %09%09%09parCl

patch for out of bounds error