001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 *  Unless required by applicable law or agreed to in writing, software
012 *  distributed under the License is distributed on an "AS IS" BASIS,
013 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 *  See the License for the specific language governing permissions and
015 *  limitations under the License.
016 *
017 */
018package org.apache.bcel.verifier;
019
020import org.apache.bcel.Repository;
021import org.apache.bcel.classfile.JavaClass;
022
023/**
024 * This class has a main method implementing a demonstration program
025 * of how to use the VerifierFactoryObserver. It transitively verifies
026 * all class files encountered; this may take up a lot of time and,
027 * more notably, memory.
028 *
029 */
030public class TransitiveHull implements VerifierFactoryObserver {
031
032    /** Used for indentation. */
033    private int indent = 0;
034
035
036    /** Not publicly instantiable. */
037    private TransitiveHull() {
038    }
039
040
041    /* Implementing VerifierFactoryObserver. */
042    @Override
043    public void update( final String classname ) {
044        System.gc(); // avoid swapping if possible.
045        for (int i = 0; i < indent; i++) {
046            System.out.print(" ");
047        }
048        System.out.println(classname);
049        indent += 1;
050        final Verifier v = VerifierFactory.getVerifier(classname);
051        VerificationResult vr;
052        vr = v.doPass1();
053        if (vr != VerificationResult.VR_OK) {
054            System.out.println("Pass 1:\n" + vr);
055        }
056        vr = v.doPass2();
057        if (vr != VerificationResult.VR_OK) {
058            System.out.println("Pass 2:\n" + vr);
059        }
060        if (vr == VerificationResult.VR_OK) {
061            try {
062                final JavaClass jc = Repository.lookupClass(v.getClassName());
063                for (int i = 0; i < jc.getMethods().length; i++) {
064                    vr = v.doPass3a(i);
065                    if (vr != VerificationResult.VR_OK) {
066                        System.out.println(v.getClassName() + ", Pass 3a, method " + i + " ['"
067                                + jc.getMethods()[i] + "']:\n" + vr);
068                    }
069                    vr = v.doPass3b(i);
070                    if (vr != VerificationResult.VR_OK) {
071                        System.out.println(v.getClassName() + ", Pass 3b, method " + i + " ['"
072                                + jc.getMethods()[i] + "']:\n" + vr);
073                    }
074                }
075            } catch (final ClassNotFoundException e) {
076                System.err.println("Could not find class " + v.getClassName() + " in Repository");
077            }
078        }
079        indent -= 1;
080    }
081
082
083    /**
084     * This method implements a demonstration program
085     * of how to use the VerifierFactoryObserver. It transitively verifies
086     * all class files encountered; this may take up a lot of time and,
087     * more notably, memory.
088     */
089    public static void main( final String[] args ) {
090        if (args.length != 1) {
091            System.out.println("Need exactly one argument: The root class to verify.");
092            System.exit(1);
093        }
094        final int dotclasspos = args[0].lastIndexOf(".class");
095        if (dotclasspos != -1) {
096            args[0] = args[0].substring(0, dotclasspos);
097        }
098        args[0] = args[0].replace('/', '.');
099        final TransitiveHull th = new TransitiveHull();
100        VerifierFactory.attach(th);
101        VerifierFactory.getVerifier(args[0]); // the observer is called back and does the actual trick.
102        VerifierFactory.detach(th);
103    }
104}