code: /*
   * 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.
   */
  /*
   * $Id$
   */
  
  package org.apache.xalan.xsltc.compiler.util;
  
  import org.apache.bcel.generic.Instruction;
  
  /**
   * <p>This pseudo-instruction marks the beginning of a region of byte code that
   * can be copied into a new method, termed an "outlineable" chunk.  The size of
   * the Java stack must be the same at the start of the region as it is at the
   * end of the region, any value on the stack at the start of the region must not
   * be consumed by an instruction in the region of code, the region must not
   * contain a return instruction, no branch instruction in the region is
   * permitted to have a target that is outside the region, and no branch
   * instruction outside the region is permitted to have a target that is inside
   * the region.</p>
   * <p>The end of the region is marked by an {@link OutlineableChunkEnd}
   * pseudo-instruction.</p>
   * <p>Such a region of code may contain other outlineable regions.</p>
   */
  class OutlineableChunkStart extends MarkerInstruction {
      /**
       * A constant instance of {@link OutlineableChunkStart}.  As it has no fields,
       * there should be no need to create an instance of this class. 
       */
      public static final Instruction OUTLINEABLECHUNKSTART =
                                                  new OutlineableChunkStart();
  
      /**
       * Private default constructor.  As it has no fields,
       * there should be no need to create an instance of this class.  See
       * {@link OutlineableChunkStart#OUTLINEABLECHUNKSTART}.
       */
      private OutlineableChunkStart() {
      }
  
      /**
       * Get the name of this instruction.  Used for debugging.
       * @return the instruction name
       */
      public String getName() {
          return OutlineableChunkStart.class.getName();
      }
  
      /**
       * Get the name of this instruction.  Used for debugging.
       * @return the instruction name
       */
      public String toString() {
          return getName();
      }
  
      /**
       * Get the name of this instruction.  Used for debugging.
       * @return the instruction name
       */
      public String toString(boolean verbose) {
          return getName();
      }
  }
  