    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}