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.statics;
18
19 import java.util.Arrays;
20
21 import org.apache.bcel.generic.Type;
22 import org.apache.bcel.verifier.exc.AssertionViolatedException;
23 import org.apache.bcel.verifier.exc.LocalVariableInfoInconsistentException;
24
25 /**
26 * A utility class holding the information about the names and the types of the local variables in a given method.
27 */
28 public class LocalVariablesInfo {
29
30 /** The information about the local variables is stored here. */
31 private final LocalVariableInfo[] localVariableInfos;
32
33 /** The constructor. */
34 LocalVariablesInfo(final int maxLocals) {
35 localVariableInfos = new LocalVariableInfo[maxLocals];
36 Arrays.setAll(localVariableInfos, i -> new LocalVariableInfo());
37 }
38
39 /**
40 * Adds information about the local variable in slot 'slot'. Automatically adds information for slot+1 if 't' is
41 * Type.LONG or Type.DOUBLE.
42 *
43 * @param slot Slot number for local variable information
44 * @param name variable name
45 * @param startPc Range in which the variable is valid.
46 * @param length length of ...
47 * @param type variable type
48 * @throws LocalVariableInfoInconsistentException if the new information conflicts with already gathered information.
49 */
50 public void add(final int slot, final String name, final int startPc, final int length, final Type type) throws LocalVariableInfoInconsistentException {
51 // The add operation on LocalVariableInfo may throw the '...Inconsistent...' exception, we don't throw it explicitly
52 // here.
53
54 if (slot < 0 || slot >= localVariableInfos.length) {
55 throw new AssertionViolatedException("Slot number for local variable information out of range.");
56 }
57
58 localVariableInfos[slot].add(name, startPc, length, type);
59 if (type == Type.LONG) {
60 localVariableInfos[slot + 1].add(name, startPc, length, LONG_Upper.theInstance());
61 }
62 if (type == Type.DOUBLE) {
63 localVariableInfos[slot + 1].add(name, startPc, length, DOUBLE_Upper.theInstance());
64 }
65 }
66
67 /**
68 * Returns the LocalVariableInfo for the given slot.
69 *
70 * @param slot Slot to query.
71 * @return The LocalVariableInfo for the given slot.
72 */
73 public LocalVariableInfo getLocalVariableInfo(final int slot) {
74 if (slot < 0 || slot >= localVariableInfos.length) {
75 throw new AssertionViolatedException("Slot number for local variable information out of range.");
76 }
77 return localVariableInfos[slot];
78 }
79 }