/*
* fb-contrib - Auxiliary detectors for Java programs
* Copyright (C) 2005-2017 Dave Brosius
*
* 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 com.mebigfatguy.fbcontrib.detect;
import java.util.Locale;
import org.apache.bcel.Repository;
import org.apache.bcel.classfile.Field;
import org.apache.bcel.classfile.JavaClass;
import org.apache.bcel.classfile.LocalVariable;
import org.apache.bcel.classfile.LocalVariableTable;
import org.apache.bcel.classfile.Method;
import com.mebigfatguy.fbcontrib.utils.BugType;
import com.mebigfatguy.fbcontrib.utils.SignatureUtils;
import com.mebigfatguy.fbcontrib.utils.Values;
import edu.umd.cs.findbugs.BugInstance;
import edu.umd.cs.findbugs.BugReporter;
import edu.umd.cs.findbugs.Detector;
import edu.umd.cs.findbugs.ba.ClassContext;
import edu.umd.cs.findbugs.visitclass.PreorderVisitor;
/**
* looks for fields and local variables that have Map, Set, List in their names but the variable is a collection of a different basic type.
*/
public class CollectionNamingConfusion extends PreorderVisitor implements Detector {
private JavaClass mapInterface;
private JavaClass setInterface;
private JavaClass listInterface;
private JavaClass queueInterface;
private BugReporter bugReporter;
private ClassContext classContext;
/**
* constructs a CNC detector given the reporter to report bugs on
*
* @param bugReporter
* the sync of bug reports
*/
public CollectionNamingConfusion(BugReporter bugReporter) {
this.bugReporter = bugReporter;
try {
mapInterface = Repository.lookupClass(Values.SLASHED_JAVA_UTIL_MAP);
setInterface = Repository.lookupClass(Values.SLASHED_JAVA_UTIL_SET);
listInterface = Repository.lookupClass(Values.SLASHED_JAVA_UTIL_LIST);
queueInterface = Repository.lookupClass(Values.SLASHED_JAVA_UTIL_QUEUE);
} catch (ClassNotFoundException cnfe) {
bugReporter.reportMissingClass(cnfe);
mapInterface = null;
setInterface = null;
listInterface = null;
queueInterface = null;
}
}
/**
* overrides the visitor to make sure that the static initializer was able to load the map class
*
* @param classContext
* the currently parsed class
*/
@Override
public void visitClassContext(ClassContext classContext) {
if (mapInterface != null) {
this.classContext = classContext;
classContext.getJavaClass().accept(this);
}
}
/**
* overrides the visitor to look for fields where the name has 'Map', 'Set', 'List' in it but the type of that field isn't that.
*
* @param obj
* the currently parsed field
*/
@Override
public void visitField(Field obj) {
if (checkConfusedName(obj.getName(), obj.getSignature())) {
bugReporter.reportBug(new BugInstance(this, BugType.CNC_COLLECTION_NAMING_CONFUSION.name(), NORMAL_PRIORITY).addClass(this).addField(this)
.addString(obj.getName()));
}
}
/**
* overrides the visitor to look for local variables where the name has 'Map', 'Set', 'List' in it but the type of that field isn't that. note that this
* only is useful if compiled with debug labels.
*
* @param obj
* the currently parsed method
*/
@Override
public void visitMethod(Method obj) {
LocalVariableTable lvt = obj.getLocalVariableTable();
if (lvt != null) {
LocalVariable[] lvs = lvt.getLocalVariableTable();
for (LocalVariable lv : lvs) {
if (checkConfusedName(lv.getName(), lv.getSignature())) {
bugReporter.reportBug(new BugInstance(this, BugType.CNC_COLLECTION_NAMING_CONFUSION.name(), NORMAL_PRIORITY).addClass(this)
.addString(lv.getName()).addSourceLine(this.classContext, this, lv.getStartPC()));
}
}
}
}
/**
* looks for a name that mentions a collection type but the wrong type for the variable
*
* @param methodOrVariableName
* the method or variable name
* @param signature
* the variable signature
* @return whether the name doesn't match the type
*/
@edu.umd.cs.findbugs.annotations.SuppressFBWarnings(value = "EXS_EXCEPTION_SOFTENING_RETURN_FALSE", justification = "No other simple way to determine whether class exists")
private boolean checkConfusedName(String methodOrVariableName, String signature) {
try {
String name = methodOrVariableName.toLowerCase(Locale.ENGLISH);
if ((name.endsWith("map") || (name.endsWith("set") && !name.endsWith("toset")) || name.endsWith("list") || name.endsWith("queue"))
&& signature.startsWith("Ljava/util/")) {
String clsName = SignatureUtils.stripSignature(signature);
JavaClass cls = Repository.lookupClass(clsName);
if ((cls.implementationOf(mapInterface) && !name.endsWith("map")) || (cls.implementationOf(setInterface) && !name.endsWith("set"))
|| (cls.implementationOf(listInterface) && !name.endsWith("list"))
|| (cls.implementationOf(queueInterface) && !name.endsWith("queue"))) {
return true;
}
}
} catch (ClassNotFoundException cnfe) {
bugReporter.reportMissingClass(cnfe);
}
return false;
}
/**
* implements the visitor by does nothing
*/
@Override
public void report() {
// not used, implements the interface
}
}