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