alvinalexander.com | career | drupal | java | mac | mysql | perl | scala | uml | unix  

Java example source code file (InvokeInstruction.java)

This example Java source code file (InvokeInstruction.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

constant, exceptionthrower, fieldormethod, invokeinstruction, stackconsumer, stackproducer, string, stringtokenizer, type, typedinstruction, util

The InvokeInstruction.java Java example source code

/*
 * reserved comment block
 * DO NOT REMOVE OR ALTER!
 */
package com.sun.org.apache.bcel.internal.generic;

/* ====================================================================
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 2001 The Apache Software Foundation.  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. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Apache" and "Apache Software Foundation" and
 *    "Apache BCEL" must not be used to endorse or promote products
 *    derived from this software without prior written permission. For
 *    written permission, please contact apache@apache.org.
 *
 * 5. Products derived from this software may not be called "Apache",
 *    "Apache BCEL", nor may "Apache" appear in their name, without
 *    prior written permission of the Apache Software Foundation.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED 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 APACHE SOFTWARE FOUNDATION OR
 * ITS 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.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */
import com.sun.org.apache.bcel.internal.Constants;
import com.sun.org.apache.bcel.internal.classfile.*;
import java.util.StringTokenizer;

/**
 * Super class for the INVOKExxx family of instructions.
 *
 * @author  <A HREF="mailto:markus.dahm@berlin.de">M. Dahm
 */
public abstract class InvokeInstruction extends FieldOrMethod
  implements ExceptionThrower, TypedInstruction, StackConsumer, StackProducer {
  /**
   * Empty constructor needed for the Class.newInstance() statement in
   * Instruction.readInstruction(). Not to be used otherwise.
   */
  InvokeInstruction() {}

  /**
   * @param index to constant pool
   */
  protected InvokeInstruction(short opcode, int index) {
    super(opcode, index);
  }

  /**
   * @return mnemonic for instruction with symbolic references resolved
   */
  public String toString(ConstantPool cp) {
    Constant        c   = cp.getConstant(index);
    StringTokenizer tok = new StringTokenizer(cp.constantToString(c));

    return Constants.OPCODE_NAMES[opcode] + " " +
      tok.nextToken().replace('.', '/') + tok.nextToken();
  }

  /**
   * Also works for instructions whose stack effect depends on the
   * constant pool entry they reference.
   * @return Number of words consumed from stack by this instruction
   */
  public int consumeStack(ConstantPoolGen cpg) {
      String signature = getSignature(cpg);
      Type[] args      = Type.getArgumentTypes(signature);
      int    sum;

      if(opcode == Constants.INVOKESTATIC)
        sum = 0;
      else
        sum = 1;  // this reference

      int n = args.length;
      for (int i = 0; i < n; i++)
        sum += args[i].getSize();

      return sum;
   }

  /**
   * Also works for instructions whose stack effect depends on the
   * constant pool entry they reference.
   * @return Number of words produced onto stack by this instruction
   */
  public int produceStack(ConstantPoolGen cpg) {
    return getReturnType(cpg).getSize();
  }

  /** @return return type of referenced method.
   */
  public Type getType(ConstantPoolGen cpg) {
    return getReturnType(cpg);
  }

  /** @return name of referenced method.
   */
  public String getMethodName(ConstantPoolGen cpg) {
    return getName(cpg);
  }

  /** @return return type of referenced method.
   */
  public Type getReturnType(ConstantPoolGen cpg) {
    return Type.getReturnType(getSignature(cpg));
  }

  /** @return argument types of referenced method.
   */
  public Type[] getArgumentTypes(ConstantPoolGen cpg) {
    return Type.getArgumentTypes(getSignature(cpg));
  }
}

Other Java examples (source code examples)

Here is a short list of links related to this Java InvokeInstruction.java source code file:

... this post is sponsored by my books ...

#1 New Release!

FP Best Seller

 

new blog posts

 

Copyright 1998-2021 Alvin Alexander, alvinalexander.com
All Rights Reserved.

A percentage of advertising revenue from
pages under the /java/jwarehouse URI on this website is
paid back to open source projects.