/*
* FindBugs - Find bugs in Java programs
* Copyright (C) 2004-2006 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.detect;
import java.util.HashSet;
import org.apache.bcel.Constants;
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.OpcodeStack;
import edu.umd.cs.findbugs.Priorities;
import edu.umd.cs.findbugs.ba.AnalysisContext;
import edu.umd.cs.findbugs.ba.NullnessAnnotation;
import edu.umd.cs.findbugs.ba.XFactory;
import edu.umd.cs.findbugs.ba.XField;
import edu.umd.cs.findbugs.bcel.OpcodeStackDetector;
public class InitializeNonnullFieldsInConstructor extends OpcodeStackDetector {
final BugReporter bugReporter;
final HashSet<XField> initializedFields = new HashSet<XField>();
final HashSet<XField> nonnullFields = new HashSet<XField>();
final HashSet<XField> nonnullStaticFields = new HashSet<XField>();
public InitializeNonnullFieldsInConstructor(BugReporter bugReporter) {
this.bugReporter = bugReporter;
}
@Override
public void setupVisitorForClass(JavaClass obj) {
super.setupVisitorForClass(obj);
nonnullFields.clear();
}
@Override
public void visitAfter(JavaClass obj) {
super.visitAfter(obj);
nonnullFields.clear();
nonnullStaticFields.clear();
}
@Override
public void visit(Field obj) {
super.visit(obj);
XField f = XFactory.createXField(this);
if (checkForInitialization(f) && !f.isSynthetic()) {
if (f.isStatic()) {
nonnullStaticFields.add(f);
} else {
nonnullFields.add(f);
}
}
}
public boolean checkForInitialization(XField f) {
if (!f.isReferenceType() || f.isFinal()) {
return false;
}
NullnessAnnotation annotation = AnalysisContext.currentAnalysisContext().getNullnessAnnotationDatabase()
.getResolvedAnnotation(f, false);
boolean isNonnull = annotation == NullnessAnnotation.NONNULL;
return isNonnull;
}
@Override
public void visit(Code code) {
boolean interesting = getMethodName().equals("<init>") || getMethodName().equals("<clinit>");
if (!interesting) {
return;
}
secondaryConstructor = false;
HashSet<XField> needToInitialize = getMethod().isStatic() ? nonnullStaticFields : nonnullFields;
if (needToInitialize.isEmpty()) {
return;
}
// initialize any variables we want to initialize for the method
super.visit(code); // make callbacks to sawOpcode for all opcodes
if (!secondaryConstructor && !initializedFields.containsAll(needToInitialize)) {
int priority = Priorities.NORMAL_PRIORITY;
if (needToInitialize.size() - initializedFields.size() == 1 && needToInitialize.size() > 1) {
priority = Priorities.HIGH_PRIORITY;
}
for (XField f : needToInitialize) {
if (initializedFields.contains(f)) {
continue;
}
BugInstance b = new BugInstance(this, "NP_NONNULL_FIELD_NOT_INITIALIZED_IN_CONSTRUCTOR", priority)
.addClassAndMethod(this).addField(f);
bugReporter.reportBug(b);
}
}
initializedFields.clear();
}
boolean secondaryConstructor;
@Override
public void sawOpcode(int seen) {
if (secondaryConstructor) {
return;
}
switch (seen) {
case Constants.INVOKESPECIAL:
if (!getMethod().isStatic() && getNameConstantOperand().equals("<init>") && isSelfOperation()) {
OpcodeStack.Item invokedOn = stack.getItemMethodInvokedOn(this);
if (invokedOn.isInitialParameter() && invokedOn.getRegisterNumber() == 0) {
secondaryConstructor = true;
}
break;
}
break;
case Constants.PUTFIELD:
if (getMethod().isStatic()) {
return;
}
OpcodeStack.Item left = stack.getStackItem(1);
if (left.isInitialParameter() && left.getRegisterNumber() == 0 && isSelfOperation()) {
XField f = getXFieldOperand();
if (f == null) {
break;
}
if (checkForInitialization(f)) {
initializedFields.add(f);
}
}
break;
case Constants.PUTSTATIC:
if (!getMethod().isStatic()) {
break;
}
if (isSelfOperation()) {
XField f = getXFieldOperand();
if (f == null) {
break;
}
if (checkForInitialization(f)) {
initializedFields.add(f);
}
}
break;
default:
break;
}
}
public boolean isSelfOperation() {
return getClassConstantOperand().equals(getClassName());
}
}