checkclassadapter.java

jboss规则引擎

/***
 * 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.drools.asm.util;

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

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

/**
 * 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,
                              boolean dump,
                              final PrintWriter pw) {
        final ClassNode cn = new ClassNode();
        cr.accept( new CheckClassAdapter( cn ),
                   true );

        final List methods = cn.methods;
        for ( int i = 0; i < methods.size(); ++i ) {
            final MethodNode method = (MethodNode) methods.get( i );
            if ( method.instructions.size() > 0 ) {
                final Analyzer a = new Analyzer( new SimpleVerifier( Type.getType( "L" + cn.name + ";" ),
                                                                     Type.getType( "L" + cn.superName + ";" ),
                                                                     (cn.access & Opcodes.ACC_INTERFACE) != 0 ) );
                try {
                    a.analyze( cn.name,
                               method );
                    if ( !dump ) {
                        continue;
                    }
                } catch ( final Exception e ) {
                    e.printStackTrace();
                }
                final Frame[] frames = a.getFrames();

                final TraceMethodVisitor mv = new TraceMethodVisitor();

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

                    final StringBuffer s = new StringBuffer();
                    final 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) {
        final 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 ( this.start ) {
            throw new IllegalStateException( "visit must be called only once" );
        } else {
            this.start = true;