/*
* FindBugs - Find bugs in Java programs
* 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.props;
import java.util.BitSet;
import java.util.Iterator;
import org.apache.bcel.Constants;
import org.apache.bcel.classfile.Method;
import org.apache.bcel.generic.Instruction;
import org.apache.bcel.generic.ReferenceType;
import org.apache.bcel.generic.Type;
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.ca.Call;
import edu.umd.cs.findbugs.ba.ca.CallList;
import edu.umd.cs.findbugs.ba.ca.CallListDataflow;
import edu.umd.cs.findbugs.ba.type.TypeDataflow;
import edu.umd.cs.findbugs.ba.type.TypeFrame;
/**
* Utility methods for creating general warning properties.
*
* @author David Hovemeyer
*/
public abstract class WarningPropertyUtil {
/** Set of instructions which operate on a receiver object. */
private static final BitSet receiverObjectInstructionSet= new BitSet();
static {
receiverObjectInstructionSet.set(Constants.INVOKEINTERFACE);
receiverObjectInstructionSet.set(Constants.INVOKEVIRTUAL);
receiverObjectInstructionSet.set(Constants.INVOKESPECIAL);
receiverObjectInstructionSet.set(Constants.GETFIELD);
receiverObjectInstructionSet.set(Constants.PUTFIELD);
receiverObjectInstructionSet.set(Constants.CHECKCAST);
receiverObjectInstructionSet.set(Constants.INSTANCEOF);
}
/**
* Get a Location matching the given PC value.
* Because of JSR subroutines, there may be multiple
* Locations referring to the given instruction. This method simply
* returns one of them arbitrarily.
*
* @param classContext the ClassContext containing the method
* @param method the method
* @param pc a PC value of an instruction in the method
* @return a Location corresponding to the PC value, or null
* if no such Location can be found
* @throws CFGBuilderException
*/
private static Location pcToLocation(
ClassContext classContext,
Method method,
int pc) throws CFGBuilderException {
CFG cfg = classContext.getCFG(method);
for (Iterator<Location> i = cfg.locationIterator(); i.hasNext();) {
Location location = i.next();
if (location.getHandle().getPosition() == pc)
return location;
}
return null;
}
/**
* Add a RECEIVER_OBJECT_TYPE warning property for a particular
* location in a method to given warning property set.
*
* @param propertySet the property set
* @param classContext ClassContext of the class containing the method
* @param method the method
* @param location Location within the method
*/
private static void addReceiverObjectType(
WarningPropertySet<WarningProperty> propertySet,
ClassContext classContext,
Method method,
Location location) {
try {
Instruction ins = location.getHandle().getInstruction();
if (!receiverObjectInstructionSet.get(ins.getOpcode()))
return;
TypeDataflow typeDataflow = classContext.getTypeDataflow(method);
TypeFrame frame = typeDataflow.getFactAtLocation(location);
if (frame.isValid()) {
Type type = frame.getInstance(ins, classContext.getConstantPoolGen());
if (type instanceof ReferenceType) {
propertySet.setProperty(GeneralWarningProperty.RECEIVER_OBJECT_TYPE, type.toString());
}
}
} catch (DataflowAnalysisException e) {
// Ignore
} catch (CFGBuilderException e) {
// Ignore
}
}
/**
* Add CALLED_METHOD_<i>n</i> warning properties based on methods
* which have been called and returned normally at given Location.
*
* @param propertySet the WarningPropertySet
* @param classContext the ClassContext
* @param method the Method
* @param location the Location
*/
private static void addRecentlyCalledMethods(
WarningPropertySet<WarningProperty> propertySet,
ClassContext classContext,
Method method,
Location location) {
try {
CallListDataflow dataflow = classContext.getCallListDataflow(method);
CallList callList = dataflow.getFactAtLocation(location);
if (!callList.isValid())
return;
int count = 0;
for (Iterator<Call> i = callList.callIterator(); count < 4 && i.hasNext(); ++count) {
Call call = i.next();
WarningProperty prop = null;
switch (count) {
case 0:
prop = GeneralWarningProperty.CALLED_METHOD_1; break;
case 1:
prop = GeneralWarningProperty.CALLED_METHOD_2; break;
case 2:
prop = GeneralWarningProperty.CALLED_METHOD_3; break;
case 3:
prop = GeneralWarningProperty.CALLED_METHOD_4; break;
}
// XXX: encode class name? signature? break down as words?
propertySet.setProperty(prop, call.getMethodName());
}
} catch (CFGBuilderException e) {
// Ignore
} catch (DataflowAnalysisException e) {
// Ignore
}
}
/**
* Add all relevant general warning properties to the given property set
* for the given Location.
*
* @param propertySet the WarningPropertySet
* @param classContext the ClassContext
* @param method the Method
* @param location the Location
*/
public static void addPropertiesForDataMining(
WarningPropertySet<WarningProperty> propertySet,
ClassContext classContext,
Method method,
Location location) {
addReceiverObjectType(propertySet, classContext, method, location);
addRecentlyCalledMethods(propertySet, classContext, method, location);
}
/**
* Add all relevant general warning properties to the given property set
* for the given Location.
*
* @param propertySet the WarningPropertySet
* @param classContext the ClassContext
* @param method the Method
* @param pc the bytecode offset of an instruction to get properties for
*/
public static void addPropertiesForLocation(
WarningPropertySet<WarningProperty> propertySet,
ClassContext classContext,
Method method,
int pc) {
try {
Location location = pcToLocation(classContext, method, pc);
if (location != null) {
addPropertiesForDataMining(propertySet, classContext, method, location);
}
} catch (CFGBuilderException e) {
// Ignore
}
}
}