classwriter.java

linux下建立JAVA虚拟机的源码KAFFE

/***
 * ASM: a very small and fast Java bytecode manipulation framework
 * Copyright (c) 2000,2002,2003 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.asm153;

/**
 * A {@link ClassVisitor ClassVisitor} that generates Java class files. More
 * precisely this visitor generates a byte array conforming to the Java class
 * file format. It can be used alone, to generate a Java class "from scratch",
 * or with one or more {@link ClassReader ClassReader} and adapter class
 * visitor to generate a modified class from one or more existing Java classes.
 * 
 * @author Eric Bruneton
 */

public class ClassWriter implements ClassVisitor {

  /**
   * The type of CONSTANT_Class constant pool items.
   */

  final static int CLASS = 7;

  /**
   * The type of CONSTANT_Fieldref constant pool items.
   */

  final static int FIELD = 9;

  /**
   * The type of CONSTANT_Methodref constant pool items.
   */

  final static int METH = 10;

  /**
   * The type of CONSTANT_InterfaceMethodref constant pool items.
   */

  final static int IMETH = 11;

  /**
   * The type of CONSTANT_String constant pool items.
   */

  final static int STR = 8;

  /**
   * The type of CONSTANT_Integer constant pool items.
   */

  final static int INT = 3;

  /**
   * The type of CONSTANT_Float constant pool items.
   */

  final static int FLOAT = 4;

  /**
   * The type of CONSTANT_Long constant pool items.
   */

  final static int LONG = 5;

  /**
   * The type of CONSTANT_Double constant pool items.
   */

  final static int DOUBLE = 6;

  /**
   * The type of CONSTANT_NameAndType constant pool items.
   */

  final static int NAME_TYPE = 12;

  /**
   * The type of CONSTANT_Utf8 constant pool items.
   */

  final static int UTF8 = 1;

  /**
   * Minor and major version numbers of the class to be generated.
   */

  private int version;

  /**
   * Index of the next item to be added in the constant pool.
   */

  private short index;

  /**
   * The constant pool of this class.
   */

  private ByteVector pool;

  /**
   * The constant pool's hash table data.
   */

  private Item[] items;

  /**
   * The threshold of the constant pool's hash table.
   */

  private int threshold;

  /**
   * The access flags of this class.
   */

  private int access;

  /**
   * The constant pool item that contains the internal name of this class.
   */

  private int name;

  /**
   * The constant pool item that contains the internal name of the super class
   * of this class.
   */

  private int superName;

  /**
   * Number of interfaces implemented or extended by this class or interface.
   */

  private int interfaceCount;

  /**
   * The interfaces implemented or extended by this class or interface. More
   * precisely, this array contains the indexes of the constant pool items
   * that contain the internal names of these interfaces.
   */

  private int[] interfaces;

  /**
   * The index of the constant pool item that contains the name of the source
   * file from which this class was compiled.
   */

  private int sourceFile;

  /**
   * Number of fields of this class.
   */

  private int fieldCount;

  /**
   * The fields of this class.
   */

  private ByteVector fields;

  /**
   * <tt>true</tt> if the maximum stack size and number of local variables must
   * be automatically computed.
   */

  private boolean computeMaxs;
  
  /**
   * <tt>true</tt> to test that all attributes are known.
   */
  
  boolean checkAttributes;

  /**
   * The methods of this class. These methods are stored in a linked list of
   * {@link CodeWriter CodeWriter} objects, linked to each other by their {@link
   * CodeWriter#next} field. This field stores the first element of this list.
   */

  CodeWriter firstMethod;

  /**
   * The methods of this class. These methods are stored in a linked list of
   * {@link CodeWriter CodeWriter} objects, linked to each other by their {@link
   * CodeWriter#next} field. This field stores the last element of this list.
   */

  CodeWriter lastMethod;

  /**
   * The number of entries in the InnerClasses attribute.
   */

  private int innerClassesCount;

  /**
   * The InnerClasses attribute.
   */

  private ByteVector innerClasses;

  /**
   * The non standard attributes of the class.
   */

  private Attribute attrs;

  /**
   * A reusable key used to look for items in the hash {@link #items items}.
   */

  Item key;

  /**
   * A reusable key used to look for items in the hash {@link #items items}.
   */

  Item key2;

  /**
   * A reusable key used to look for items in the hash {@link #items items}.
   */

  Item key3;

  /**
   * The type of instructions without any label.
   */

  final static int NOARG_INSN = 0;

  /**
   * The type of instructions with an signed byte label.
   */

  final static int SBYTE_INSN = 1;

  /**
   * The type of instructions with an signed short label.
   */

  final static int SHORT_INSN = 2;

  /**
   * The type of instructions with a local variable index label.
   */

  final static int VAR_INSN = 3;

  /**
   * The type of instructions with an implicit local variable index label.
   */

  final static int IMPLVAR_INSN = 4;

  /**
   * The type of instructions with a type descriptor argument.
   */

  final static int TYPE_INSN = 5;

  /**
   * The type of field and method invocations instructions.
   */

  final static int FIELDORMETH_INSN = 6;

  /**
   * The type of the INVOKEINTERFACE instruction.
   */

  final static int ITFMETH_INSN = 7;

  /**
   * The type of instructions with a 2 bytes bytecode offset label.
   */

  final static int LABEL_INSN = 8;

  /**
   * The type of instructions with a 4 bytes bytecode offset label.
   */

  final static int LABELW_INSN = 9;

  /**
   * The type of the LDC instruction.
   */

  final static int LDC_INSN = 10;

  /**
   * The type of the LDC_W and LDC2_W instructions.
   */

  final static int LDCW_INSN = 11;

  /**
   * The type of the IINC instruction.
   */

  final static int IINC_INSN = 12;

  /**
   * The type of the TABLESWITCH instruction.
   */

  final static int TABL_INSN = 13;

  /**
   * The type of the LOOKUPSWITCH instruction.
   */

  final static int LOOK_INSN = 14;

  /**
   * The type of the MULTIANEWARRAY instruction.
   */

  final static int MANA_INSN = 15;

  /**
   * The type of the WIDE instruction.
   */

  final static int WIDE_INSN = 16;

  /**
   * The instruction types of all JVM opcodes.
   */

  static byte[] TYPE;

  // --------------------------------------------------------------------------
  // Static initializer