001/* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 * 017 */ 018package org.apache.bcel.verifier.structurals; 019 020import org.apache.bcel.generic.InstructionHandle; 021 022/** 023 * This interface defines properties of JVM bytecode subroutines. Note that it is 'abused' to maintain the top-level 024 * code in a consistent fashion, too. 025 */ 026public interface Subroutine { 027 028 /** 029 * Returns all the JsrInstructions that have the first instruction of this subroutine as their target. <B>Must not 030 * be invoked on the 'top-level subroutine'.</B> 031 * 032 * @return The JsrInstructions that have the first instruction of this subroutine as their target. 033 */ 034 InstructionHandle[] getEnteringJsrInstructions(); 035 036 /** 037 * Returns the one and only RET that leaves the subroutine. Note that JustIce has a pretty rigid notion of a 038 * subroutine. <B>Must not be invoked on the 'top-level subroutine'.</B> 039 * 040 * @return The one and only RET that leaves the subroutine. 041 * 042 * @see Subroutines 043 */ 044 InstructionHandle getLeavingRET(); 045 046 /** 047 * Returns all instructions that together form this subroutine. Note that an instruction is part of exactly one 048 * subroutine (the top-level code is considered to be a special subroutine) - else it is not reachable at all (dead 049 * code). 050 * 051 * @return All instructions that together form this subroutine. 052 */ 053 InstructionHandle[] getInstructions(); 054 055 /** 056 * Returns if the given InstructionHandle refers to an instruction that is part of this subroutine. This is a 057 * convenience method that saves iteration over the InstructionHandle objects returned by getInstructions(). 058 * 059 * @param inst The InstructionHandle to test. 060 * @return Whether the given InstructionHandle refers to an instruction that is part of this subroutine. 061 * 062 * @see #getInstructions() 063 */ 064 boolean contains(InstructionHandle inst); 065 066 /** 067 * Returns an int[] containing the indices of the local variable slots accessed by this Subroutine (read-accessed, 068 * write-accessed or both); local variables referenced by subroutines of this subroutine are not included. 069 * 070 * @return An int[] containing the indices of the local variable slots. 071 * @see #getRecursivelyAccessedLocalsIndices() 072 */ 073 int[] getAccessedLocalsIndices(); 074 075 /** 076 * Returns an int[] containing the indices of the local variable slots accessed by this Subroutine (read-accessed, 077 * write-accessed or both); local variables referenced by subroutines of this subroutine are included. 078 * 079 * @return An int[] containing the indices of the local variable slots. 080 * @see #getAccessedLocalsIndices() 081 */ 082 int[] getRecursivelyAccessedLocalsIndices(); 083 084 /** 085 * Returns the subroutines that are directly called from this subroutine. 086 * 087 * @return The subroutines that are directly called from this subroutine. 088 */ 089 Subroutine[] subSubs(); 090}