/*
* FindBugs - Find bugs in Java programs
* Copyright (C) 2003-2005, 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;
import java.io.IOException;
import java.util.BitSet;
import java.util.Iterator;
import javax.annotation.CheckForNull;
import org.apache.bcel.classfile.LineNumberTable;
import org.apache.bcel.classfile.LocalVariable;
import org.apache.bcel.classfile.LocalVariableTable;
import org.apache.bcel.classfile.Method;
import org.apache.bcel.generic.IndexedInstruction;
import org.apache.bcel.generic.InstructionHandle;
import edu.umd.cs.findbugs.OpcodeStack.Item;
import edu.umd.cs.findbugs.ba.AnalysisContext;
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.Dataflow;
import edu.umd.cs.findbugs.ba.DataflowAnalysisException;
import edu.umd.cs.findbugs.ba.LiveLocalStoreAnalysis;
import edu.umd.cs.findbugs.ba.Location;
import edu.umd.cs.findbugs.ba.SignatureParser;
import edu.umd.cs.findbugs.util.EditDistance;
import edu.umd.cs.findbugs.visitclass.DismantleBytecode;
import edu.umd.cs.findbugs.visitclass.PreorderVisitor;
import edu.umd.cs.findbugs.xml.XMLAttributeList;
import edu.umd.cs.findbugs.xml.XMLOutput;
/**
* Bug annotation class for local variable names
*
* @author William Pugh
* @see BugAnnotation
*/
public class LocalVariableAnnotation implements BugAnnotation {
private static final long serialVersionUID = 1L;
public static final String DEFAULT_ROLE = "LOCAL_VARIABLE_DEFAULT";
public static final String NAMED_ROLE = "LOCAL_VARIABLE_NAMED";
public static final String UNKNOWN_ROLE = "LOCAL_VARIABLE_UNKNOWN";
public static final String PARAMETER_ROLE = "LOCAL_VARIABLE_PARAMETER";
public static final String PARAMETER_NAMED_ROLE = "LOCAL_VARIABLE_PARAMETER_NAMED";
public static final String PARAMETER_VALUE_SOURCE_ROLE = "LOCAL_VARIABLE_PARAMETER_VALUE_SOURCE";
public static final String PARAMETER_VALUE_SOURCE_NAMED_ROLE = "LOCAL_VARIABLE_PARAMETER_VALUE_SOURCE_NAMED";
public static final String VALUE_DOOMED_ROLE = "LOCAL_VARIABLE_VALUE_DOOMED";
public static final String VALUE_DOOMED_NAMED_ROLE = "LOCAL_VARIABLE_VALUE_DOOMED_NAMED";
public static final String DID_YOU_MEAN_ROLE = "LOCAL_VARIABLE_DID_YOU_MEAN";
public static final String INVOKED_ON_ROLE = "LOCAL_VARIABLE_INVOKED_ON";
public static final String ARGUMENT_ROLE = "LOCAL_VARIABLE_ARGUMENT";
public static final String VALUE_OF_ROLE = "LOCAL_VARIABLE_VALUE_OF";
final private String name;
final int register, pc;
final int line;
private String description;
/**
* Constructor.
*
* @param name
* the name of the local variable
* @param register
* the local variable index
* @param pc
* the bytecode offset of the instruction that mentions this
* local variable
*/
public LocalVariableAnnotation(String name, int register, int pc) {
this.name = name;
this.register = register;
this.pc = pc;
this.line = -1;
this.description = DEFAULT_ROLE;
this.setDescription(name.equals("?") ? "LOCAL_VARIABLE_UNKNOWN" : "LOCAL_VARIABLE_NAMED");
}
/**
* Constructor.
*
* @param name
* the name of the local variable
* @param register
* the local variable index
* @param pc
* the bytecode offset of the instruction that mentions this
* local variable
*/
public LocalVariableAnnotation(String name, int register, int pc, int line) {
this.name = name;
this.register = register;
this.pc = pc;
this.line = line;
this.description = DEFAULT_ROLE;
this.setDescription(name.equals("?") ? "LOCAL_VARIABLE_UNKNOWN" : "LOCAL_VARIABLE_NAMED");
}
public static LocalVariableAnnotation getLocalVariableAnnotation(Method method, Location location, IndexedInstruction ins) {
int local = ins.getIndex();
InstructionHandle handle = location.getHandle();
int position1 = handle.getNext().getPosition();
int position2 = handle.getPosition();
return getLocalVariableAnnotation(method, local, position1, position2);
}
public static LocalVariableAnnotation getLocalVariableAnnotation(Method method, int local, int position1, int position2) {
LocalVariableTable localVariableTable = method.getLocalVariableTable();
String localName = "?";
if (localVariableTable != null) {
LocalVariable lv1 = localVariableTable.getLocalVariable(local, position1);
if (lv1 == null) {
lv1 = localVariableTable.getLocalVariable(local, position2);
position1 = position2;
}
if (lv1 != null) {
localName = lv1.getName();
} else {
for (LocalVariable lv : localVariableTable.getLocalVariableTable()) {
if (lv.getIndex() == local) {
if (!localName.equals("?") && !localName.equals(lv.getName())) {
// not a single consistent name
localName = "?";
break;
}
localName = lv.getName();
}
}
}
}
LineNumberTable lineNumbers = method.getLineNumberTable();
if (lineNumbers == null) {
return new LocalVariableAnnotation(localName, local, position1);
}
int line = lineNumbers.getSourceLine(position1);
return new LocalVariableAnnotation(localName, local, position1, line);
}
/**
* Get a local variable annotation describing a parameter.
*
* @param method
* a Method
* @param local
* the local variable containing the parameter
* @return LocalVariableAnnotation describing the parameter
*/
public static LocalVariableAnnotation getParameterLocalVariableAnnotation(Method method, int local) {
LocalVariableAnnotation lva = getLocalVariableAnnotation(method, local, 0, 0);
if (lva.isNamed()) {
lva.setDescription(LocalVariableAnnotation.PARAMETER_NAMED_ROLE);
} else {
lva.setDescription(LocalVariableAnnotation.PARAMETER_ROLE);
}
return lva;
}
@Override
public Object clone() {
try {
return super.clone();
} catch (CloneNotSupportedException e) {
throw new AssertionError(e);
}
}
@Override
public void accept(BugAnnotationVisitor visitor) {
visitor.visitLocalVariableAnnotation(this);
}
@Override
public String format(String key, ClassAnnotation primaryClass) {
// System.out.println("format: " + key + " reg: " + register + " name: "
// + value);
if (key.equals("hash")) {
if (register < 0) {
return "??";
}
return name;
}
if (register < 0) {
return "?";
}
if (key.equals("register")) {
return String.valueOf(register);
} else if (key.equals("pc")) {
return String.valueOf(pc);
} else if (key.equals("name") || key.equals("givenClass")) {
return name;
} else if (!name.equals("?")) {
return name;
}
return "$L" + register;
}
@Override
public void setDescription(String description) {
this.description = description.intern();
}
@Override
public String getDescription() {
return description;
}
@Override
public int hashCode() {
return name.hashCode();
}
@Override
public boolean equals(Object o) {
if (!(o instanceof LocalVariableAnnotation)) {
return false;
}
return name.equals(((LocalVariableAnnotation) o).name);
}
@Override
public int compareTo(BugAnnotation o) {
if (!(o instanceof LocalVariableAnnotation)) {
// Comparable with any type
// of BugAnnotation
return this.getClass().getName().compareTo(o.getClass().getName());
}
return name.compareTo(((LocalVariableAnnotation) o).name);
}
@Override
public String toString() {
String pattern = I18N.instance().getAnnotationDescription(description);
FindBugsMessageFormat format = new FindBugsMessageFormat(pattern);
return format.format(new BugAnnotation[] { this }, null);
}
/*
* ----------------------------------------------------------------------
* XML Conversion support
* ----------------------------------------------------------------------
*/
private static final String ELEMENT_NAME = "LocalVariable";
@Override
public void writeXML(XMLOutput xmlOutput) throws IOException {
writeXML(xmlOutput, false, false);
}
@Override
public void writeXML(XMLOutput xmlOutput, boolean addMessages, boolean isPrimary) throws IOException {
XMLAttributeList attributeList = new XMLAttributeList().addAttribute("name", name)
.addAttribute("register", String.valueOf(register)).addAttribute("pc", String.valueOf(pc));
String role = getDescription();
if (!role.equals(DEFAULT_ROLE)) {
attributeList.addAttribute("role", role);
}
BugAnnotationUtil.writeXML(xmlOutput, ELEMENT_NAME, this, attributeList, addMessages);
}
public boolean isNamed() {
return register >= 0 && !name.equals("?");
}
/**
* @return name of local variable
*/
public String getName() {
return name;
}
public int getPC() {
return pc;
}
public int getRegister() {
return register;
}
@Override
public boolean isSignificant() {
return !name.equals("?");
}
public static @CheckForNull
LocalVariableAnnotation getLocalVariableAnnotation(Method method, Item item, int pc) {
int reg = item.getRegisterNumber();
if (reg < 0) {
return null;
}
return getLocalVariableAnnotation(method, reg, pc, item.getPC());
}
public static @CheckForNull
LocalVariableAnnotation getLocalVariableAnnotation(DismantleBytecode visitor, Item item) {
int reg = item.getRegisterNumber();
if (reg < 0) {
return null;
}
return getLocalVariableAnnotation(visitor.getMethod(), reg, visitor.getPC(), item.getPC());
}
public static @CheckForNull
LocalVariableAnnotation findMatchingIgnoredParameter(ClassContext classContext, Method method, String name, String signature) {
try {
Dataflow<BitSet, LiveLocalStoreAnalysis> llsaDataflow = classContext.getLiveLocalStoreDataflow(method);
CFG cfg;
cfg = classContext.getCFG(method);
LocalVariableAnnotation match = null;
int lowestCost = Integer.MAX_VALUE;
BitSet liveStoreSetAtEntry = llsaDataflow.getAnalysis().getResultFact(cfg.getEntry());
int localsThatAreParameters = PreorderVisitor.getNumberArguments(method.getSignature());
int startIndex = 0;
if (!method.isStatic()) {
startIndex = 1;
}
SignatureParser parser = new SignatureParser(method.getSignature());
Iterator<String> signatureIterator = parser.parameterSignatureIterator();
for (int i = startIndex; i < localsThatAreParameters + startIndex; i++) {
String sig = signatureIterator.next();
if (!liveStoreSetAtEntry.get(i) && signature.equals(sig)) {
// parameter isn't live and signatures match
LocalVariableAnnotation potentialMatch = LocalVariableAnnotation.getLocalVariableAnnotation(method, i, 0, 0);
potentialMatch.setDescription(DID_YOU_MEAN_ROLE);
if (!potentialMatch.isNamed()) {
return potentialMatch;
}
int distance = EditDistance.editDistance(name, potentialMatch.getName());
if (distance < lowestCost) {
match = potentialMatch;
match.setDescription(DID_YOU_MEAN_ROLE);
lowestCost = distance;
} else if (distance == lowestCost) {
// not unique best match
match = null;
}
}
}
return match;
} catch (DataflowAnalysisException e) {
AnalysisContext.logError("", e);
} catch (CFGBuilderException e) {
AnalysisContext.logError("", e);
}
return null;
}
public static @CheckForNull
LocalVariableAnnotation findUniqueBestMatchingParameter(ClassContext classContext, Method method, String name,
String signature) {
LocalVariableAnnotation match = null;
int localsThatAreParameters = PreorderVisitor.getNumberArguments(method.getSignature());
int startIndex = 0;
if (!method.isStatic()) {
startIndex = 1;
}
SignatureParser parser = new SignatureParser(method.getSignature());
Iterator<String> signatureIterator = parser.parameterSignatureIterator();
int lowestCost = Integer.MAX_VALUE;
for (int i = startIndex; i < localsThatAreParameters + startIndex; i++) {
String sig = signatureIterator.next();
if (signature.equals(sig)) {
LocalVariableAnnotation potentialMatch = LocalVariableAnnotation.getLocalVariableAnnotation(method, i, 0, 0);
if (!potentialMatch.isNamed()) {
continue;
}
int distance = EditDistance.editDistance(name, potentialMatch.getName());
if (distance < lowestCost) {
match = potentialMatch;
match.setDescription(DID_YOU_MEAN_ROLE);
lowestCost = distance;
} else if (distance == lowestCost) {
// not unique best match
match = null;
}
// signatures match
}
}
if (lowestCost < 5) {
return match;
}
return null;
}
@Override
public String toString(ClassAnnotation primaryClass) {
return toString();
}
}