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