inefficientmemberaccess.java

A static analysis tool to find bugs in Java programs

/*
 * FindBugs - Find bugs in Java programs
 * Copyright (C) 2005 Dave Brosius <[e-mail]>
 * 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 edu.umd.cs.findbugs.*;
import edu.umd.cs.findbugs.ba.ClassContext;
import org.apache.bcel.classfile.JavaClass;
import org.apache.bcel.generic.Type;

public class InefficientMemberAccess extends BytecodeScanningDetector implements StatelessDetector {

	public static final String ACCESS_PREFIX = "access$";
	private BugReporter bugReporter;
	private String clsName;

	public InefficientMemberAccess(BugReporter bugReporter) {
		this.bugReporter = bugReporter;
	}



	@Override
		 public void visitClassContext(ClassContext classContext) {
		JavaClass cls = classContext.getJavaClass();
		clsName = cls.getClassName();
		if (clsName.indexOf("$") >= 0)
			super.visitClassContext(classContext);
	}

	@Override
		 public void sawOpcode(int seen) {

		if (seen == INVOKESTATIC) {
			String methodName = getNameConstantOperand();
			if (!methodName.startsWith(ACCESS_PREFIX))
				return;
			
			String methodSig = getSigConstantOperand();
			Type[] argTypes = Type.getArgumentTypes(methodSig);
			if ((argTypes.length < 1) || (argTypes.length > 2))
				return;
			String parCls = argTypes[0].getSignature();
			if (parCls.length() < 3) return;
			parCls = parCls.substring(1, parCls.length() - 1);
			if (!parCls.equals(getClassConstantOperand()))
				return;
			if ((argTypes.length == 2) && !argTypes[1].getSignature().equals(Type.getReturnType(methodSig).getSignature()))
				return;

			bugReporter.reportBug(new BugInstance(this, "IMA_INEFFICIENT_MEMBER_ACCESS", LOW_PRIORITY)
				.addClassAndMethod(this)
				.addSourceLine(this));
		}
	}




}