package edu.umd.cs.findbugs.detect;
import static org.apache.bcel.Constants.DCMPG;
import static org.apache.bcel.Constants.DCMPL;
import static org.apache.bcel.Constants.FCMPG;
import static org.apache.bcel.Constants.FCMPL;
import static org.apache.bcel.Constants.IAND;
import static org.apache.bcel.Constants.IF_ACMPEQ;
import static org.apache.bcel.Constants.IF_ACMPNE;
import static org.apache.bcel.Constants.IF_ICMPEQ;
import static org.apache.bcel.Constants.IF_ICMPGE;
import static org.apache.bcel.Constants.IF_ICMPGT;
import static org.apache.bcel.Constants.IF_ICMPLE;
import static org.apache.bcel.Constants.IF_ICMPLT;
import static org.apache.bcel.Constants.IF_ICMPNE;
import static org.apache.bcel.Constants.INVOKEINTERFACE;
import static org.apache.bcel.Constants.INVOKEVIRTUAL;
import static org.apache.bcel.Constants.IOR;
import static org.apache.bcel.Constants.ISUB;
import static org.apache.bcel.Constants.IXOR;
import static org.apache.bcel.Constants.LAND;
import static org.apache.bcel.Constants.LCMP;
import static org.apache.bcel.Constants.LOR;
import static org.apache.bcel.Constants.LSUB;
import static org.apache.bcel.Constants.LXOR;
import static org.apache.bcel.Constants.POP;
import java.util.BitSet;
import java.util.Iterator;
import org.apache.bcel.classfile.Method;
import org.apache.bcel.generic.ConstantPoolGen;
import org.apache.bcel.generic.Instruction;
import org.apache.bcel.generic.InvokeInstruction;
import org.apache.bcel.generic.MethodGen;
import edu.umd.cs.findbugs.BugAnnotation;
import edu.umd.cs.findbugs.BugInstance;
import edu.umd.cs.findbugs.BugReporter;
import edu.umd.cs.findbugs.Detector;
import edu.umd.cs.findbugs.FieldAnnotation;
import edu.umd.cs.findbugs.SourceLineAnnotation;
import edu.umd.cs.findbugs.SystemProperties;
import edu.umd.cs.findbugs.ba.CFG;
import edu.umd.cs.findbugs.ba.CFGBuilderException;
import edu.umd.cs.findbugs.ba.ClassContext;
import edu.umd.cs.findbugs.ba.DataflowAnalysisException;
import edu.umd.cs.findbugs.ba.Location;
import edu.umd.cs.findbugs.ba.MethodUnprofitableException;
import edu.umd.cs.findbugs.ba.SignatureParser;
import edu.umd.cs.findbugs.ba.XField;
import edu.umd.cs.findbugs.ba.vna.ValueNumber;
import edu.umd.cs.findbugs.ba.vna.ValueNumberDataflow;
import edu.umd.cs.findbugs.ba.vna.ValueNumberFrame;
import edu.umd.cs.findbugs.ba.vna.ValueNumberSourceInfo;
public class FindSelfComparison2 implements Detector {
private BugReporter bugReporter;
public FindSelfComparison2(BugReporter bugReporter) {
this.bugReporter = bugReporter;
}
public void visitClassContext(ClassContext classContext) {
Method[] methodList = classContext.getJavaClass().getMethods();
for (Method method : methodList) {
if (method.getCode() == null)
continue;
try {
analyzeMethod(classContext, method);
} catch (MethodUnprofitableException mue) {
if (SystemProperties.getBoolean("unprofitable.debug")) // otherwise don't report
bugReporter.logError("skipping unprofitable method in " + getClass().getName());
} catch (CFGBuilderException e) {
bugReporter.logError("Detector " + this.getClass().getName()
+ " caught exception", e);
} catch (DataflowAnalysisException e) {
bugReporter.logError("Detector " + this.getClass().getName()
+ " caught exception", e);
}
}
}
private void analyzeMethod(ClassContext classContext, Method method)
throws CFGBuilderException, DataflowAnalysisException {
CFG cfg = classContext.getCFG(method);
ValueNumberDataflow valueNumberDataflow = classContext
.getValueNumberDataflow(method);
ConstantPoolGen cpg = classContext.getConstantPoolGen();
MethodGen methodGen = classContext.getMethodGen(method);
String sourceFile = classContext.getJavaClass().getSourceFileName();
for (Iterator<Location> i = cfg.locationIterator(); i.hasNext();) {
Location location = i.next();
Instruction ins = location.getHandle().getInstruction();
switch(ins.getOpcode()) {
case INVOKEVIRTUAL:
case INVOKEINTERFACE:
InvokeInstruction iins = (InvokeInstruction) ins;
String invoking = iins.getName(cpg);
if (invoking.equals("equals") || invoking.equals("compareTo")) {
if (methodGen.getName().toLowerCase().indexOf("test") >= 0)
break;
if (methodGen.getClassName().toLowerCase().indexOf("test") >= 0)
break;
if (classContext.getJavaClass().getSuperclassName().toLowerCase().indexOf("test") >= 0)
break;
if (location.getHandle().getNext().getInstruction().getOpcode() == POP)
break;
String sig = iins.getSignature(cpg);
SignatureParser parser = new SignatureParser(sig);
if (parser.getNumParameters() == 1
&& (invoking.equals("equals") && sig.endsWith(";)Z") || invoking.equals("compareTo")
&& sig.endsWith(";)I")))
checkForSelfOperation(classContext, location, valueNumberDataflow, "COMPARISON", method, methodGen,
sourceFile);
}
break;
case LOR:
case LAND:
case LXOR:
case LSUB:
case IOR:
case IAND:
case IXOR:
case ISUB:
checkForSelfOperation(classContext, location, valueNumberDataflow, "COMPUTATION", method, methodGen, sourceFile);
break;
case FCMPG:
case DCMPG:
case DCMPL:
case FCMPL:
break;
case LCMP:
case IF_ACMPEQ:
case IF_ACMPNE:
case IF_ICMPNE:
case IF_ICMPEQ:
case IF_ICMPGT:
case IF_ICMPLE:
case IF_ICMPLT:
case IF_ICMPGE:
checkForSelfOperation(classContext, location, valueNumberDataflow, "COMPARISON", method, methodGen, sourceFile);
}
}
}
/**
* @param classContext TODO
* @param location
* @param method TODO
* @param methodGen TODO
* @param sourceFile TODO
* @param string
* @throws DataflowAnalysisException
*/
private void checkForSelfOperation(ClassContext classContext, Location location, ValueNumberDataflow valueNumberDataflow, String op, Method method, MethodGen methodGen, String sourceFile) throws DataflowAnalysisException {
ValueNumberFrame frame = valueNumberDataflow.getFactAtLocation(location);
if (!frame.isValid()) return;
Instruction ins = location.getHandle().getInstruction();
int opcode = ins.getOpcode();
int offset = 1;
if (opcode == LCMP || opcode == LXOR || opcode == LAND || opcode == LOR || opcode == LSUB)
offset = 2;
ValueNumber v0 = frame.getStackValue(0);
ValueNumber v1 = frame.getStackValue(offset);
if (!v1.equals(v0)) return;
if (v0.hasFlag(ValueNumber.CONSTANT_CLASS_OBJECT) || v0.hasFlag(ValueNumber.CONSTANT_VALUE)) return;
int priority = HIGH_PRIORITY;
if (opcode == ISUB || opcode == LSUB || opcode == INVOKEINTERFACE || opcode == INVOKEVIRTUAL)
priority = NORMAL_PRIORITY;
XField field = ValueNumberSourceInfo.findXFieldFromValueNumber(method, location, v0, frame);
BugAnnotation annotation;
String prefix;
if (field != null) {
if (field.isVolatile()) return;
if (true) return; // don't report these; too many false positives
annotation = FieldAnnotation.fromXField(field);
prefix = "SA_FIELD_SELF_";
} else {
annotation = ValueNumberSourceInfo.findLocalAnnotationFromValueNumber(method, location, v0, frame);
prefix = "SA_LOCAL_SELF_" ;
if (opcode == ISUB) return; // only report this if simple detector reports it
}
if (annotation == null) return;
SourceLineAnnotation sourceLine = SourceLineAnnotation.fromVisitedInstruction(classContext, methodGen, sourceFile, location.getHandle());
int line = sourceLine.getStartLine();
BitSet occursMultipleTimes = ClassContext.linesMentionedMultipleTimes(method);
if (line > 0 && occursMultipleTimes.get(line)) return;
BugInstance bug = new BugInstance(this, prefix + op, priority).addClassAndMethod(methodGen, sourceFile)
.add(annotation).addSourceLine(classContext, methodGen, sourceFile, location.getHandle());
bugReporter.reportBug(bug);
}
public void report() {
}
}