/*
* 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.Method;
import edu.umd.cs.findbugs.BugAccumulator;
import edu.umd.cs.findbugs.BugInstance;
import edu.umd.cs.findbugs.BugReporter;
import edu.umd.cs.findbugs.BytecodeScanningDetector;
import edu.umd.cs.findbugs.Lookup;
import edu.umd.cs.findbugs.StatelessDetector;
import edu.umd.cs.findbugs.SystemProperties;
public class FindFinalizeInvocations extends BytecodeScanningDetector implements StatelessDetector {
private static final boolean DEBUG = SystemProperties.getBoolean("ffi.debug");
private final BugReporter bugReporter;
private final BugAccumulator bugAccumulator;
public FindFinalizeInvocations(BugReporter bugReporter) {
this.bugReporter = bugReporter;
this.bugAccumulator = new BugAccumulator(bugReporter);
}
boolean sawSuperFinalize;
@Override
public void visit(Method obj) {
if (DEBUG) {
System.out.println("FFI: visiting " + getFullyQualifiedMethodName());
}
if (getMethodName().equals("finalize") && getMethodSig().equals("()V") && (obj.getAccessFlags() & (ACC_PUBLIC)) != 0) {
bugReporter
.reportBug(new BugInstance(this, "FI_PUBLIC_SHOULD_BE_PROTECTED", NORMAL_PRIORITY).addClassAndMethod(this));
}
}
@Override
public void visit(Code obj) {
sawSuperFinalize = false;
super.visit(obj);
bugAccumulator.reportAccumulatedBugs();
if (!getMethodName().equals("finalize") || !getMethodSig().equals("()V")) {
return;
}
String overridesFinalizeIn = Lookup.findSuperImplementor(getDottedClassName(), "finalize", "()V", bugReporter);
boolean superHasNoFinalizer = overridesFinalizeIn.equals("java.lang.Object");
// System.out.println("superclass: " + superclassName);
if (obj.getCode().length == 1) {
if (superHasNoFinalizer) {
if (!getMethod().isFinal()) {
bugReporter.reportBug(new BugInstance(this, "FI_EMPTY", NORMAL_PRIORITY).addClassAndMethod(this));
}
} else {
bugReporter.reportBug(new BugInstance(this, "FI_NULLIFY_SUPER", NORMAL_PRIORITY).addClassAndMethod(this)
.addClass(overridesFinalizeIn));
}
} else if (obj.getCode().length == 5 && sawSuperFinalize) {
bugReporter.reportBug(new BugInstance(this, "FI_USELESS", NORMAL_PRIORITY).addClassAndMethod(this));
} else if (!sawSuperFinalize && !superHasNoFinalizer) {
bugReporter.reportBug(new BugInstance(this, "FI_MISSING_SUPER_CALL", NORMAL_PRIORITY).addClassAndMethod(this)
.addClass(overridesFinalizeIn));
}
}
@Override
public void sawOpcode(int seen) {
if (seen == INVOKEVIRTUAL && getNameConstantOperand().equals("finalize") && getSigConstantOperand().equals("()V")) {
bugAccumulator.accumulateBug(
new BugInstance(this, "FI_EXPLICIT_INVOCATION", getMethodName().equals("finalize")
&& getMethodSig().equals("()V") ? HIGH_PRIORITY : NORMAL_PRIORITY).addClassAndMethod(this)
.addCalledMethod(this), this);
}
if (seen == INVOKESPECIAL && getNameConstantOperand().equals("finalize")) {
sawSuperFinalize = true;
}
}
}