    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 */
    017package org.apache.bcel.verifier;
    018
    019import java.util.ArrayList;
    020import java.util.HashMap;
    021import java.util.List;
    022import java.util.Map;
    023
    024import org.apache.bcel.classfile.JavaClass;
    025import org.apache.bcel.classfile.Utility;
    026import org.apache.bcel.verifier.statics.Pass1Verifier;
    027import org.apache.bcel.verifier.statics.Pass2Verifier;
    028import org.apache.bcel.verifier.statics.Pass3aVerifier;
    029import org.apache.bcel.verifier.structurals.Pass3bVerifier;
    030import org.apache.commons.lang3.ArrayUtils;
    031
    032/**
    033 * A Verifier instance is there to verify a class file according to The Java Virtual Machine Specification, 2nd Edition.
    034 *
    035 * Pass-3b-verification includes pass-3a-verification; pass-3a-verification includes pass-2-verification;
    036 * pass-2-verification includes pass-1-verification.
    037 *
    038 * A Verifier creates PassVerifier instances to perform the actual verification. Verifier instances are usually
    039 * generated by the VerifierFactory.
    040 *
    041 * @see VerifierFactory
    042 * @see PassVerifier
    043 */
    044public class Verifier {
    045
    046    static final Verifier[] EMPTY_ARRAY = {};
    047
    048    /**
    049     * Verifies class files. This is a simple demonstration of how the API of BCEL's class file verifier "JustIce" may be
    050     * used. You should supply command-line arguments which are fully qualified namea of the classes to verify. These class
    051     * files must be somewhere in your CLASSPATH (refer to Sun's documentation for questions about this) or you must have
    052     * put the classes into the BCEL Repository yourself (via 'addClass(JavaClass)').
    053     */
    054    public static void main(final String[] args) {
    055        System.out.println("JustIce by Enver Haase, (C) 2001-2002.\n<http://bcel.sourceforge.net>\n<https://commons.apache.org/bcel>\n");
    056        for (int index = 0; index < args.length; index++) {
    057            try {
    058                if (args[index].endsWith(".class")) {
    059                    final int dotclasspos = args[index].lastIndexOf(".class");
    060                    if (dotclasspos != -1) {
    061                        args[index] = args[index].substring(0, dotclasspos);
    062                    }
    063                }
    064                args[index] = Utility.pathToPackage(args[index]);
    065                System.out.println("Now verifying: " + args[index] + "\n");
    066                verifyType(args[index]);
    067                org.apache.bcel.Repository.clearCache();
    068                System.gc();
    069            } catch (final ClassNotFoundException e) {
    070                e.printStackTrace();
    071            }
    072        }
    073    }
    074
    075    static void verifyType(final String fullyQualifiedClassName) throws ClassNotFoundException {
    076        final Verifier verifier = VerifierFactory.getVerifier(fullyQualifiedClassName);
    077        VerificationResult verificationResult;
    078        verificationResult = verifier.doPass1();
    079        System.out.println("Pass 1:\n" + verificationResult);
    080        verificationResult = verifier.doPass2();
    081        System.out.println("Pass 2:\n" + verificationResult);
    082        if (verificationResult == VerificationResult.VR_OK) {
    083            final JavaClass jc = org.apache.bcel.Repository.lookupClass(fullyQualifiedClassName);
    084            for (int i = 0; i < jc.getMethods().length; i++) {
    085                verificationResult = verifier.doPass3a(i);
    086                System.out.println("Pass 3a, method number " + i + " ['" + jc.getMethods()[i] + "']:\n" + verificationResult);
    087                verificationResult = verifier.doPass3b(i);
    088                System.out.println("Pass 3b, method number " + i + " ['" + jc.getMethods()[i] + "']:\n" + verificationResult);
    089            }
    090        }
    091        System.out.println("Warnings:");
    092        final String[] warnings = verifier.getMessages();
    093        if (warnings.length == 0) {
    094            System.out.println("<none>");
    095        }
    096        for (final String warning : warnings) {
    097            System.out.println(warning);
    098        }
    099        System.out.println("\n");
    100        // avoid swapping.
    101        verifier.flush();
    102    }
    103
    104    /**
    105     * The name of the class this verifier operates on.
    106     */
    107    private final String className;
    108
    109    /** A Pass1Verifier for this Verifier instance. */
    110    private Pass1Verifier p1v;
    111
    112    /** A Pass2Verifier for this Verifier instance. */
    113    private Pass2Verifier p2v;
    114
    115    /** The Pass3aVerifiers for this Verifier instance. Key: Interned string specifying the method number. */
    116    private final Map<String, Pass3aVerifier> p3avs = new HashMap<>();
    117
    118    /** The Pass3bVerifiers for this Verifier instance. Key: Interned string specifying the method number. */
    119    private final Map<String, Pass3bVerifier> p3bvs = new HashMap<>();
    120
    121    /**
    122     * Instantiation is done by the VerifierFactory.
    123     *
    124     * @see VerifierFactory
    125     */
    126    Verifier(final String fullyQualifiedClassName) {
    127        className = fullyQualifiedClassName;
    128    }
    129
    130    /** Returns the VerificationResult for the given pass. */
    131    public VerificationResult doPass1() {
    132        if (p1v == null) {
    133            p1v = new Pass1Verifier(this);
    134        }
    135        return p1v.verify();
    136    }
    137
    138    /** Returns the VerificationResult for the given pass. */
    139    public VerificationResult doPass2() {
    140        if (p2v == null) {
    141            p2v = new Pass2Verifier(this);
    142        }
    143        return p2v.verify();
    144    }
    145
    146    /**
    147     * Returns the VerificationResult for the given pass.
    148     *
    149     * @param methodNo The method to verify
    150     * @return the VerificationResult
    151     */
    152    public VerificationResult doPass3a(final int methodNo) {
    153        return p3avs.computeIfAbsent(Integer.toString(methodNo), k -> new Pass3aVerifier(this, methodNo)).verify();
    154    }
    155
    156    /**
    157     * Returns the VerificationResult for the given pass.
    158     *
    159     * @param methodNo The method to verify
    160     * @return the VerificationResult
    161     */
    162    public VerificationResult doPass3b(final int methodNo) {
    163        return p3bvs.computeIfAbsent(Integer.toString(methodNo), k -> new Pass3bVerifier(this, methodNo)).verify();
    164    }
    165
    166    /**
    167     * Forget everything known about the class file; that means, really start a new verification of a possibly different
    168     * class file from BCEL's repository.
    169     */
    170    public void flush() {
    171        p1v = null;
    172        p2v = null;
    173        p3avs.clear();
    174        p3bvs.clear();
    175    }
    176
    177    /**
    178     * Returns the name of the class this verifier operates on. This is particularly interesting when this verifier was
    179     * created recursively by another Verifier and you got a reference to this Verifier by the getVerifiers() method of the
    180     * VerifierFactory.
    181     *
    182     * @see VerifierFactory
    183     */
    184    public final String getClassName() {
    185        return className;
    186    }
    187
    188    /**
    189     * This returns all the (warning) messages collected during verification. A prefix shows from which verifying pass a
    190     * message originates.
    191     */
    192    public String[] getMessages() throws ClassNotFoundException {
    193        final List<String> messages = new ArrayList<>();
    194        if (p1v != null) {
    195            p1v.getMessagesList().forEach(element -> messages.add("Pass 1: " + element));
    196        }
    197        if (p2v != null) {
    198            p2v.getMessagesList().forEach(element -> messages.add("Pass 2: " + element));
    199        }
    200        for (final Pass3aVerifier pv : p3avs.values()) {
    201            final int meth = pv.getMethodNo();
    202            for (final String element : pv.getMessages()) {
    203                messages.add("Pass 3a, method " + meth + " ('" + org.apache.bcel.Repository.lookupClass(className).getMethods()[meth] + "'): " + element);
    204            }
    205        }
    206        for (final Pass3bVerifier pv : p3bvs.values()) {
    207            final int meth = pv.getMethodNo();
    208            for (final String element : pv.getMessages()) {
    209                messages.add("Pass 3b, method " + meth + " ('" + org.apache.bcel.Repository.lookupClass(className).getMethods()[meth] + "'): " + element);
    210            }
    211        }
    212
    213        return messages.toArray(ArrayUtils.EMPTY_STRING_ARRAY);
    214    }
    215}