checkclassadapter.java

asm的源码包 并且包含英文的文档

/***
 * ASM: a very small and fast Java bytecode manipulation framework
 * Copyright (c) 2000-2005 INRIA, France Telecom
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the copyright holders nor the names of its
 *    contributors may be used to endorse or promote products derived from
 *    this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 * THE POSSIBILITY OF SUCH DAMAGE.
 */
package org.objectweb.asm.util;

import java.io.FileInputStream;
import java.io.PrintWriter;
import java.util.List;

import org.objectweb.asm.AnnotationVisitor;
import org.objectweb.asm.FieldVisitor;
import org.objectweb.asm.ClassAdapter;
import org.objectweb.asm.ClassReader;
import org.objectweb.asm.ClassVisitor;
import org.objectweb.asm.MethodVisitor;
import org.objectweb.asm.Opcodes;
import org.objectweb.asm.Attribute;
import org.objectweb.asm.Type;
import org.objectweb.asm.tree.MethodNode;
import org.objectweb.asm.tree.ClassNode;
import org.objectweb.asm.tree.TryCatchBlockNode;
import org.objectweb.asm.tree.analysis.Analyzer;
import org.objectweb.asm.tree.analysis.SimpleVerifier;
import org.objectweb.asm.tree.analysis.Frame;

/**
 * A {@link ClassAdapter} that checks that its methods are properly used. More
 * precisely this class adapter checks each method call individually, based
 * <i>only</i> on its arguments, but does <i>not</i> check the <i>sequence</i>
 * of method calls. For example, the invalid sequence
 * <tt>visitField(ACC_PUBLIC, "i", "I", null)</tt> <tt>visitField(ACC_PUBLIC,
 * "i", "D", null)</tt>
 * will <i>not</i> be detected by this class adapter.
 * 
 * @author Eric Bruneton
 */
public class CheckClassAdapter extends ClassAdapter {

    /**
     * <tt>true</tt> if the visit method has been called.
     */
    private boolean start;

    /**
     * <tt>true</tt> if the visitSource method has been called.
     */
    private boolean source;

    /**
     * <tt>true</tt> if the visitOuterClass method has been called.
     */
    private boolean outer;

    /**
     * <tt>true</tt> if the visitEnd method has been called.
     */
    private boolean end;

    /**
     * Checks a given class. <p> Usage: CheckClassAdapter &lt;fully qualified
     * class name or class file name&gt;
     * 
     * @param args the command line arguments.
     * 
     * @throws Exception if the class cannot be found, or if an IO exception
     *         occurs.
     */
    public static void main(final String[] args) throws Exception {
        if (args.length != 1) {
            System.err.println("Verifies the given class.");
            System.err.println("Usage: CheckClassAdapter "
                    + "<fully qualified class name or class file name>");
            return;
        }
        ClassReader cr;
        if (args[0].endsWith(".class")) {
            cr = new ClassReader(new FileInputStream(args[0]));
        } else {
            cr = new ClassReader(args[0]);
        }

        verify(cr, false, new PrintWriter(System.err));
    }

    /**
     * Checks a given class
     * 
     * @param cr a <code>ClassReader</code> that contains bytecode for the
     *        analysis.
     * @param dump true if bytecode should be printed out not only when errors
     *        are found.
     * @param pw write where results going to be printed
     */
    public static void verify(
        final ClassReader cr,
        final boolean dump,
        final PrintWriter pw)
    {
        ClassNode cn = new ClassNode();
        cr.accept(new CheckClassAdapter(cn), ClassReader.SKIP_DEBUG);

        List methods = cn.methods;
        for (int i = 0; i < methods.size(); ++i) {
            MethodNode method = (MethodNode) methods.get(i);
            Analyzer a = new Analyzer(new SimpleVerifier(Type.getObjectType(cn.name),
                    Type.getObjectType(cn.superName),
                    false));
            try {
                a.analyze(cn.name, method);
                if (!dump) {
                    continue;
                }
            } catch (Exception e) {
                e.printStackTrace();
            }
            Frame[] frames = a.getFrames();

            TraceMethodVisitor mv = new TraceMethodVisitor();

            pw.println(method.name + method.desc);
            for (int j = 0; j < method.instructions.size(); ++j) {
                method.instructions.get(j).accept(mv);

                StringBuffer s = new StringBuffer();
                Frame f = frames[j];
                if (f == null) {
                    s.append('?');
                } else {
                    for (int k = 0; k < f.getLocals(); ++k) {
                        s.append(getShortName(f.getLocal(k).toString()))
                                .append(' ');
                    }
                    s.append(" : ");
                    for (int k = 0; k < f.getStackSize(); ++k) {
                        s.append(getShortName(f.getStack(k).toString()))
                                .append(' ');
                    }
                }
                while (s.length() < method.maxStack + method.maxLocals + 1) {
                    s.append(' ');
                }
                pw.print(Integer.toString(j + 100000).substring(1));
                pw.print(" " + s + " : " + mv.buf); // mv.text.get(j));
            }
            for (int j = 0; j < method.tryCatchBlocks.size(); ++j) {
                ((TryCatchBlockNode) method.tryCatchBlocks.get(j)).accept(mv);
                pw.print(" " + mv.buf);
            }
            pw.println();
        }
    }

    private static String getShortName(final String name) {
        int n = name.lastIndexOf('/');
        int k = name.length();
        if (name.charAt(k - 1) == ';') {
            k--;
        }
        return n == -1 ? name : name.substring(n + 1, k);
    }

    /**
     * Constructs a new {@link CheckClassAdapter}.
     * 
     * @param cv the class visitor to which this adapter must delegate calls.
     */
    public CheckClassAdapter(final ClassVisitor cv) {
        super(cv);
    }

    // ------------------------------------------------------------------------
    // Implementation of the ClassVisitor interface
    // ------------------------------------------------------------------------

    public void visit(
        final int version,
        final int access,
        final String name,
        final String signature,
        final String superName,
        final String[] interfaces)
    {
        if (start) {
            throw new IllegalStateException("visit must be called only once");
        } else {