1/*
2 * Copyright (c) 2009, 2012, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 */
23package jdk.vm.ci.meta;
24
25import java.util.Objects;
26
27/**
28 * Represents an exception handler within the bytecodes.
29 */
30public final class ExceptionHandler {
31
32    private final int startBCI;
33    private final int endBCI;
34    private final int handlerBCI;
35    private final int catchTypeCPI;
36    private final JavaType catchType;
37
38    /**
39     * Creates a new exception handler with the specified ranges.
40     *
41     * @param startBCI the start index of the protected range
42     * @param endBCI the end index of the protected range
43     * @param catchBCI the index of the handler
44     * @param catchTypeCPI the index of the throwable class in the constant pool
45     * @param catchType the type caught by this exception handler
46     */
47    public ExceptionHandler(int startBCI, int endBCI, int catchBCI, int catchTypeCPI, JavaType catchType) {
48        this.startBCI = startBCI;
49        this.endBCI = endBCI;
50        this.handlerBCI = catchBCI;
51        this.catchTypeCPI = catchTypeCPI;
52        this.catchType = catchType;
53    }
54
55    /**
56     * Returns the start bytecode index of the protected range of this handler.
57     */
58    public int getStartBCI() {
59        return startBCI;
60    }
61
62    /**
63     * Returns the end bytecode index of the protected range of this handler.
64     */
65    public int getEndBCI() {
66        return endBCI;
67    }
68
69    /**
70     * Returns the bytecode index of the handler block of this handler.
71     */
72    public int getHandlerBCI() {
73        return handlerBCI;
74    }
75
76    /**
77     * Returns the index into the constant pool representing the type of exception caught by this
78     * handler.
79     */
80    public int catchTypeCPI() {
81        return catchTypeCPI;
82    }
83
84    /**
85     * Checks whether this handler catches all exceptions.
86     *
87     * @return {@code true} if this handler catches all exceptions
88     */
89    public boolean isCatchAll() {
90        return catchTypeCPI == 0;
91    }
92
93    /**
94     * Returns the type of exception caught by this exception handler.
95     */
96    public JavaType getCatchType() {
97        return catchType;
98    }
99
100    @Override
101    public boolean equals(Object obj) {
102        if (!(obj instanceof ExceptionHandler)) {
103            return false;
104        }
105        ExceptionHandler that = (ExceptionHandler) obj;
106        if (this.startBCI != that.startBCI || this.endBCI != that.endBCI || this.handlerBCI != that.handlerBCI || this.catchTypeCPI != that.catchTypeCPI) {
107            return false;
108        }
109        return Objects.equals(this.catchType, that.catchType);
110    }
111
112    @Override
113    public String toString() {
114        return "ExceptionHandler<startBCI=" + startBCI + ", endBCI=" + endBCI + ", handlerBCI=" + handlerBCI + ", catchTypeCPI=" + catchTypeCPI + ", catchType=" + catchType + ">";
115    }
116
117    @Override
118    public int hashCode() {
119        return catchTypeCPI ^ endBCI ^ handlerBCI;
120    }
121}
122