[Fb-contrib-commit] fb-contrib/src/com/mebigfatguy/fbcontrib/detect ParallelLists.java,NONE,1.1

[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-serv13034/src/com/mebigfatguy/fbcontrib/detect

Added Files:
	ParallelLists.java 
Log Message:
Initial Checkin: PL detector

--- NEW FILE: ParallelLists.java ---
package com.mebigfatguy.fbcontrib.detect;

import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;

import org.apache.bcel.classfile.Code;
import org.apache.bcel.classfile.Field;
import org.apache.bcel.classfile.JavaClass;

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

public class ParallelLists extends BytecodeScanningDetector implements StatelessDetector
{
	private BugReporter bugReporter;
	private OpcodeStack stack = new OpcodeStack();
	private Set<String> listFields = new HashSet<String>();
	private Map<Integer, String> indexToFieldMap = new HashMap<Integer, String>();
	
	public ParallelLists(BugReporter bugReporter) {
		this.bugReporter = bugReporter;
	}
	
	public Object clone() throws CloneNotSupportedException {
		return super.clone();
	}
	
	public void visitClassContext(ClassContext classContext) {
		JavaClass cls = classContext.getJavaClass();

		listFields.clear();
		Field[] flds = cls.getFields();
		for (Field f : flds) {
			String sig = f.getSignature();
			if (sig.charAt(0) == 'L') {
				sig = sig.substring(1, sig.length() - 1);
				if (sig.startsWith("java/util/") && sig.endsWith("List")) {
					listFields.add(f.getName());
				}
			} else if (sig.charAt(0) == '[')
				listFields.add(f.getName());
		}
		
		if (listFields.size() > 0)
			super.visitClassContext(classContext);
	}
	
	public void visitCode(Code obj) {
		stack.resetForMethodEntry(this);
		indexToFieldMap.clear();
		super.visitCode(obj);
	}
	
	public void sawOpcode(int seen) {
		try {
			if (seen == INVOKEINTERFACE) {
				String className = getClassConstantOperand();
				String methodName = getNameConstantOperand();
				String methodSig = getSigConstantOperand();
				
				if ("java/util/List".equals(className) 
				&&  "get".equals(methodName)
				&&  "(I)Ljava/lang/Object;".equals(methodSig)) {
					if (stack.getStackDepth() > 2) {
						OpcodeStack.Item index = stack.getStackItem(0);
						OpcodeStack.Item list =stack.getStackItem(1);
						
						int indexReg = index.getRegisterNumber();
						FieldAnnotation fa = list.getField();
						
						if ((indexReg >= 0) && (fa != null)) {
							if (listFields.contains(fa.getFieldName())) {
								String f = indexToFieldMap.get(new Integer(indexReg));
								if (f != null) {
									bugReporter.reportBug( new BugInstance( this, "PL_PARALLEL_LISTS", NORMAL_PRIORITY)
										.addClass(this)
										.addMethod(this)
										.addSourceLine(this, getPC()));
								}
								listFields.remove(fa.getFieldName());
								indexToFieldMap.clear();
							}
							else
								indexToFieldMap.put(new Integer(indexReg), fa.getFieldName());
						}
					}
				}
			} else if ((seen >= IFEQ) && (seen <= RETURN)) {
				indexToFieldMap.clear();
			}
		} finally {
			stack.sawOpcode(this, seen);
		}
	}
}