/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 */
package org.apache.bcel.verifier;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.apache.bcel.classfile.JavaClass;
import org.apache.bcel.verifier.statics.Pass1Verifier;
import org.apache.bcel.verifier.statics.Pass2Verifier;
import org.apache.bcel.verifier.statics.Pass3aVerifier;
import org.apache.bcel.verifier.structurals.Pass3bVerifier;

A Verifier instance is there to verify a class file according to The Java Virtual
Machine Specification, 2nd Edition.
Pass-3b-verification includes pass-3a-verification;
pass-3a-verification includes pass-2-verification;
pass-2-verification includes pass-1-verification.
A Verifier creates PassVerifier instances to perform the actual verification.
Verifier instances are usually generated by the VerifierFactory.
See Also:
VerifierFactory
PassVerifier/**
 * A Verifier instance is there to verify a class file according to The Java Virtual
 * Machine Specification, 2nd Edition.
 *
 * Pass-3b-verification includes pass-3a-verification;
 * pass-3a-verification includes pass-2-verification;
 * pass-2-verification includes pass-1-verification.
 *
 * A Verifier creates PassVerifier instances to perform the actual verification.
 * Verifier instances are usually generated by the VerifierFactory.
 *
 * @see VerifierFactory
 * @see PassVerifier
 */
public class Verifier {

    
The name of the class this verifier operates on.
/**
     * The name of the class this verifier operates on.
     */
    private final String classname;
    
A Pass1Verifier for this Verifier instance. /** A Pass1Verifier for this Verifier instance. */
    private Pass1Verifier p1v;
    
A Pass2Verifier for this Verifier instance. /** A Pass2Verifier for this Verifier instance. */
    private Pass2Verifier p2v;
    
The Pass3aVerifiers for this Verifier instance. Key: Interned string specifying the method number. /** The Pass3aVerifiers for this Verifier instance. Key: Interned string specifying the method number. */
    private final Map<String, Pass3aVerifier> p3avs = new HashMap<>();
    
The Pass3bVerifiers for this Verifier instance. Key: Interned string specifying the method number. /** The Pass3bVerifiers for this Verifier instance. Key: Interned string specifying the method number. */
    private final Map<String, Pass3bVerifier> p3bvs = new HashMap<>();


    
Returns the VerificationResult for the given pass. /** Returns the VerificationResult for the given pass. */
    public VerificationResult doPass1() {
        if (p1v == null) {
            p1v = new Pass1Verifier(this);
        }
        return p1v.verify();
    }


    
Returns the VerificationResult for the given pass. /** Returns the VerificationResult for the given pass. */
    public VerificationResult doPass2() {
        if (p2v == null) {
            p2v = new Pass2Verifier(this);
        }
        return p2v.verify();
    }


    
Returns the VerificationResult for the given pass. /** Returns the VerificationResult for the given pass. */
    public VerificationResult doPass3a( final int method_no ) {
        final String key = Integer.toString(method_no);
        Pass3aVerifier p3av;
        p3av = p3avs.get(key);
        if (p3avs.get(key) == null) {
            p3av = new Pass3aVerifier(this, method_no);
            p3avs.put(key, p3av);
        }
        return p3av.verify();
    }


    
Returns the VerificationResult for the given pass. /** Returns the VerificationResult for the given pass. */
    public VerificationResult doPass3b( final int method_no ) {
        final String key = Integer.toString(method_no);
        Pass3bVerifier p3bv;
        p3bv = p3bvs.get(key);
        if (p3bvs.get(key) == null) {
            p3bv = new Pass3bVerifier(this, method_no);
            p3bvs.put(key, p3bv);
        }
        return p3bv.verify();
    }


    
Instantiation is done by the VerifierFactory.
See Also:
VerifierFactory/**
     * Instantiation is done by the VerifierFactory.
     *
     * @see VerifierFactory
     */
    Verifier(final String fully_qualified_classname) {
        classname = fully_qualified_classname;
        flush();
    }


    
Returns the name of the class this verifier operates on.
This is particularly interesting when this verifier was created
recursively by another Verifier and you got a reference to this
Verifier by the getVerifiers() method of the VerifierFactory.
See Also:
VerifierFactory/**
     * Returns the name of the class this verifier operates on.
     * This is particularly interesting when this verifier was created
     * recursively by another Verifier and you got a reference to this
     * Verifier by the getVerifiers() method of the VerifierFactory.
     * @see VerifierFactory
     */
    public final String getClassName() {
        return classname;
    }


    
Forget everything known about the class file; that means, really
start a new verification of a possibly different class file from
BCEL's repository.
/**
     * Forget everything known about the class file; that means, really
     * start a new verification of a possibly different class file from
     * BCEL's repository.
     *
     */
    public void flush() {
        p1v = null;
        p2v = null;
        p3avs.clear();
        p3bvs.clear();
    }


    
This returns all the (warning) messages collected during verification.
A prefix shows from which verifying pass a message originates.
/**
     * This returns all the (warning) messages collected during verification.
     * A prefix shows from which verifying pass a message originates.
     */
    public String[] getMessages() throws ClassNotFoundException {
        final List<String> messages = new ArrayList<>();
        if (p1v != null) {
            final String[] p1m = p1v.getMessages();
            for (final String element : p1m) {
                messages.add("Pass 1: " + element);
            }
        }
        if (p2v != null) {
            final String[] p2m = p2v.getMessages();
            for (final String element : p2m) {
                messages.add("Pass 2: " + element);
            }
        }
        for (final Pass3aVerifier pv : p3avs.values()) {
            final String[] p3am = pv.getMessages();
            final int meth = pv.getMethodNo();
            for (final String element : p3am) {
                messages.add("Pass 3a, method " + meth + " ('"
                        + org.apache.bcel.Repository.lookupClass(classname).getMethods()[meth]
                        + "'): " + element);
            }
        }
        for (final Pass3bVerifier pv : p3bvs.values()) {
            final String[] p3bm = pv.getMessages();
            final int meth = pv.getMethodNo();
            for (final String element : p3bm) {
                messages.add("Pass 3b, method " + meth + " ('"
                        + org.apache.bcel.Repository.lookupClass(classname).getMethods()[meth]
                        + "'): " + element);
            }
        }

        return messages.toArray(new String[messages.size()]);
    }


    
Verifies class files.
This is a simple demonstration of how the API of BCEL's
class file verifier "JustIce" may be used.
You should supply command-line arguments which are
fully qualified namea of the classes to verify. These class files
must be somewhere in your CLASSPATH (refer to Sun's
documentation for questions about this) or you must have put the classes
into the BCEL Repository yourself (via 'addClass(JavaClass)').
/**
     * Verifies class files.
     * This is a simple demonstration of how the API of BCEL's
     * class file verifier "JustIce" may be used.
     * You should supply command-line arguments which are
     * fully qualified namea of the classes to verify. These class files
     * must be somewhere in your CLASSPATH (refer to Sun's
     * documentation for questions about this) or you must have put the classes
     * into the BCEL Repository yourself (via 'addClass(JavaClass)').
     */
    public static void main( final String[] args ) {
        System.out
                .println("JustIce by Enver Haase, (C) 2001-2002.\n<http://bcel.sourceforge.net>\n<https://commons.apache.org/bcel>\n");
        for (int index = 0; index < args.length; index++) {
            try {
                if (args[index].endsWith(".class")) {
                    final int dotclasspos = args[index].lastIndexOf(".class");
                    if (dotclasspos != -1) {
                        args[index] = args[index].substring(0, dotclasspos);
                    }
                }
                args[index] = args[index].replace('/', '.');
                System.out.println("Now verifying: " + args[index] + "\n");
                verifyType(args[index]);
                org.apache.bcel.Repository.clearCache();
                System.gc();
            } catch (final ClassNotFoundException e) {
                e.printStackTrace();
            }
        }
    }


    static void verifyType(final String fullyQualifiedClassName) throws ClassNotFoundException {
        final Verifier verifier = VerifierFactory.getVerifier(fullyQualifiedClassName);
        VerificationResult verificationResult;
        verificationResult = verifier.doPass1();
        System.out.println("Pass 1:\n" + verificationResult);
        verificationResult = verifier.doPass2();
        System.out.println("Pass 2:\n" + verificationResult);
        if (verificationResult == VerificationResult.VR_OK) {
            final JavaClass jc = org.apache.bcel.Repository.lookupClass(fullyQualifiedClassName);
            for (int i = 0; i < jc.getMethods().length; i++) {
                verificationResult = verifier.doPass3a(i);
                System.out.println("Pass 3a, method number " + i + " ['"
                        + jc.getMethods()[i] + "']:\n" + verificationResult);
                verificationResult = verifier.doPass3b(i);
                System.out.println("Pass 3b, method number " + i + " ['"
                        + jc.getMethods()[i] + "']:\n" + verificationResult);
            }
        }
        System.out.println("Warnings:");
        final String[] warnings = verifier.getMessages();
        if (warnings.length == 0) {
            System.out.println("<none>");
        }
        for (final String warning : warnings) {
            System.out.println(warning);
        }
        System.out.println("\n");
        // avoid swapping.
        verifier.flush();
    }
}