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    1   /*
    2    * Copyright  2000-2004 The Apache Software Foundation
    3    *
    4    *  Licensed under the Apache License, Version 2.0 (the "License");
    5    *  you may not use this file except in compliance with the License.
    6    *  You may obtain a copy of the License at
    7    *
    8    *      http://www.apache.org/licenses/LICENSE-2.0
    9    *
    10   *  Unless required by applicable law or agreed to in writing, software
    11   *  distributed under the License is distributed on an "AS IS" BASIS,
    12   *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13   *  See the License for the specific language governing permissions and
    14   *  limitations under the License.
    15   *
    16   */
    17  package org.apache.bcel.verifier.structurals;
    18
    19
    20  import org.apache.bcel.generic.InstructionHandle;
    21
    22  /***
    23   * This interface defines properties of JVM bytecode subroutines.
    24   * Note that it is 'abused' to maintain the top-level code in a
    25   * consistent fashion, too.
    26   *
    27   * @version $Id: Subroutine.java 371539 2006-01-23 14:08:00Z tcurdt $
    28   * @author Enver Haase
    29   */
    30  public interface Subroutine{
    31  	/***
    32  	 * Returns all the JsrInstructions that have the
    33  	 * first instruction of this subroutine as their target.
    34  	 * <B>Must not be invoked on the 'top-level subroutine'.</B>
    35  	 */
    36  	public InstructionHandle[] getEnteringJsrInstructions();
    37
    38  	/***
    39  	 * Returns the one and only RET that leaves the subroutine.
    40  	 * Note that JustIce has a pretty rigid notion of a subroutine.
    41  	 * <B>Must not be invoked on the 'top-level subroutine'.</B>
    42  	 *
    43  	 * @see org.apache.bcel.verifier.structurals.Subroutines
    44  	 */
    45  	public InstructionHandle getLeavingRET();
    46
    47  	/***
    48  	 * Returns all instructions that together form this subroutine.
    49  	 * Note that an instruction is part of exactly one subroutine
    50  	 * (the top-level code is considered to be a special subroutine) -
    51  	 * else it is not reachable at all (dead code).
    52  	 */
    53  	public InstructionHandle[] getInstructions();
    54
    55  	/***
    56  	 * Returns if the given InstructionHandle refers to an instruction
    57  	 * that is part of this subroutine. This is a convenience method
    58  	 * that saves iteration over the InstructionHandle objects returned
    59  	 * by getInstructions().
    60  	 *
    61  	 * @see #getInstructions()
    62  	 */
    63  	public boolean contains(InstructionHandle inst);
    64
    65  	/***
    66  	 * Returns an int[] containing the indices of the local variable slots
    67  	 * accessed by this Subroutine (read-accessed, write-accessed or both);
    68  	 * local variables referenced by subroutines of this subroutine are
    69  	 * not included.
    70  	 *
    71  	 * @see #getRecursivelyAccessedLocalsIndices()
    72  	 */
    73  	public int[] getAccessedLocalsIndices();
    74
    75  	/***
    76  	 * Returns an int[] containing the indices of the local variable slots
    77  	 * accessed by this Subroutine (read-accessed, write-accessed or both);
    78  	 * local variables referenced by subroutines of this subroutine are
    79  	 * included.
    80  	 *
    81  	 * @see #getAccessedLocalsIndices()
    82  	 */
    83  	public int[] getRecursivelyAccessedLocalsIndices();
    84
    85  	/***
    86  	 * Returns the subroutines that are directly called from this subroutine.
    87  	 */
    88  	public Subroutine[] subSubs();
    89  }