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 if the given InstructionHandle refers to an instruction that is part of this subroutine. This is a 030 * convenience method that saves iteration over the InstructionHandle objects returned by getInstructions(). 031 * 032 * @param inst The InstructionHandle to test. 033 * @return Whether the given InstructionHandle refers to an instruction that is part of this subroutine. 034 * 035 * @see #getInstructions() 036 */ 037 boolean contains(InstructionHandle inst); 038 039 /** 040 * Returns an int[] containing the indices of the local variable slots accessed by this Subroutine (read-accessed, 041 * write-accessed or both); local variables referenced by subroutines of this subroutine are not included. 042 * 043 * @return An int[] containing the indices of the local variable slots. 044 * @see #getRecursivelyAccessedLocalsIndices() 045 */ 046 int[] getAccessedLocalsIndices(); 047 048 /** 049 * Returns all the JsrInstructions that have the first instruction of this subroutine as their target. <B>Must not be 050 * invoked on the 'top-level subroutine'.</B> 051 * 052 * @return The JsrInstructions that have the first instruction of this subroutine as their target. 053 */ 054 InstructionHandle[] getEnteringJsrInstructions(); 055 056 /** 057 * Returns all instructions that together form this subroutine. Note that an instruction is part of exactly one 058 * subroutine (the top-level code is considered to be a special subroutine) - else it is not reachable at all (dead 059 * code). 060 * 061 * @return All instructions that together form this subroutine. 062 */ 063 InstructionHandle[] getInstructions(); 064 065 /** 066 * Returns the one and only RET that leaves the subroutine. Note that JustIce has a pretty rigid notion of a subroutine. 067 * <B>Must not be invoked on the 'top-level subroutine'.</B> 068 * 069 * @return The one and only RET that leaves the subroutine. 070 * 071 * @see Subroutines 072 */ 073 InstructionHandle getLeavingRET(); 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}