/*
* FindBugs - Find bugs in Java programs
* Copyright (C) 2003,2004 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 org.apache.bcel.classfile.Code;
import org.apache.bcel.classfile.JavaClass;
import org.apache.bcel.classfile.Method;
import edu.umd.cs.findbugs.BugAccumulator;
import edu.umd.cs.findbugs.BugInstance;
import edu.umd.cs.findbugs.BugReporter;
import edu.umd.cs.findbugs.LocalVariableAnnotation;
import edu.umd.cs.findbugs.OpcodeStack;
import edu.umd.cs.findbugs.ba.AnalysisContext;
import edu.umd.cs.findbugs.bcel.OpcodeStackDetector;
public class FindReturnRef extends OpcodeStackDetector {
boolean check = false;
boolean thisOnTOS = false;
boolean fieldOnTOS = false;
boolean publicClass = false;
boolean staticMethod = false;
String nameOnStack;
String classNameOnStack;
String sigOnStack;
int parameterCount;
boolean fieldIsStatic;
private final BugAccumulator bugAccumulator;
// private LocalVariableTable variableNames;
public FindReturnRef(BugReporter bugReporter) {
this.bugAccumulator = new BugAccumulator(bugReporter);
}
@Override
public void visit(JavaClass obj) {
publicClass = obj.isPublic();
super.visit(obj);
}
@Override
public void visitAfter(JavaClass obj) {
bugAccumulator.reportAccumulatedBugs();
}
@Override
public void visit(Method obj) {
check = publicClass && (obj.getAccessFlags() & (ACC_PUBLIC)) != 0;
if (!check) {
return;
}
staticMethod = (obj.getAccessFlags() & (ACC_STATIC)) != 0;
// variableNames = obj.getLocalVariableTable();
parameterCount = getNumberMethodArguments();
if (!staticMethod) {
parameterCount++;
}
thisOnTOS = false;
fieldOnTOS = false;
super.visit(obj);
thisOnTOS = false;
fieldOnTOS = false;
}
@Override
public void visit(Code obj) {
if (check) {
super.visit(obj);
}
}
@Override
public void sawOpcode(int seen) {
if (!check) {
return;
}
if (staticMethod && seen == PUTSTATIC && MutableStaticFields.mutableSignature(getSigConstantOperand())) {
OpcodeStack.Item top = stack.getStackItem(0);
if (isPotentialCapture(top)) {
bugAccumulator.accumulateBug(
new BugInstance(this, "EI_EXPOSE_STATIC_REP2", NORMAL_PRIORITY)
.addClassAndMethod(this)
.addReferencedField(this)
.add(LocalVariableAnnotation.getLocalVariableAnnotation(getMethod(), top.getRegisterNumber(),
getPC(), getPC() - 1)), this);
}
}
if (!staticMethod && seen == PUTFIELD && MutableStaticFields.mutableSignature(getSigConstantOperand())) {
OpcodeStack.Item top = stack.getStackItem(0);
OpcodeStack.Item target = stack.getStackItem(1);
if (isPotentialCapture(top) && target.getRegisterNumber() == 0) {
bugAccumulator.accumulateBug(
new BugInstance(this, "EI_EXPOSE_REP2", NORMAL_PRIORITY)
.addClassAndMethod(this)
.addReferencedField(this)
.add(LocalVariableAnnotation.getLocalVariableAnnotation(getMethod(), top.getRegisterNumber(),
getPC(), getPC() - 1)), this);
}
}
if (seen == ALOAD_0 && !staticMethod) {
thisOnTOS = true;
fieldOnTOS = false;
return;
}
if (thisOnTOS && seen == GETFIELD && getClassConstantOperand().equals(getClassName())
&& !AnalysisContext.currentXFactory().isEmptyArrayField(getXFieldOperand())) {
fieldOnTOS = true;
thisOnTOS = false;
nameOnStack = getNameConstantOperand();
classNameOnStack = getDottedClassConstantOperand();
sigOnStack = getSigConstantOperand();
fieldIsStatic = false;
return;
}
if (seen == GETSTATIC && getClassConstantOperand().equals(getClassName())
&& !AnalysisContext.currentXFactory().isEmptyArrayField(getXFieldOperand())) {
fieldOnTOS = true;
thisOnTOS = false;
nameOnStack = getNameConstantOperand();
classNameOnStack = getDottedClassConstantOperand();
sigOnStack = getSigConstantOperand();
fieldIsStatic = true;
return;
}
thisOnTOS = false;
if (check && fieldOnTOS && seen == ARETURN
/*
* && !sigOnStack.equals("Ljava/lang/String;") &&
* sigOnStack.indexOf("Exception") == -1 && sigOnStack.indexOf("[") >= 0
*/
&& nameOnStack.indexOf("EMPTY") == -1 && MutableStaticFields.mutableSignature(sigOnStack)) {
bugAccumulator.accumulateBug(new BugInstance(this, staticMethod ? "MS_EXPOSE_REP" : "EI_EXPOSE_REP", NORMAL_PRIORITY)
.addClassAndMethod(this).addField(classNameOnStack, nameOnStack, sigOnStack, fieldIsStatic), this);
}
fieldOnTOS = false;
thisOnTOS = false;
}
private boolean isPotentialCapture(OpcodeStack.Item top) {
if (!top.isInitialParameter()) {
return false;
}
if ((getMethod().getAccessFlags() & ACC_VARARGS) == 0) {
return true;
}
if (top.getRegisterNumber() == parameterCount - 1)
{
return false; // var-arg parameter
}
return true;
}
}