1 /*
2 * Copyright (c) 2010, 2013, 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. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package jdk.nashorn.internal.ir;
27
28 import java.util.Arrays;
29 import java.util.List;
30
31 import jdk.nashorn.internal.codegen.Label;
32 import jdk.nashorn.internal.ir.annotations.Immutable;
33
34 /**
35 * This class represents a node from which control flow can execute
36 * a {@code break} statement
37 */
38 @Immutable
39 public abstract class BreakableNode extends LexicalContextNode {
40
41 /** break label. */
42 protected final Label breakLabel;
43
44 /**
45 * Constructor
46 *
47 * @param lineNumber line number
48 * @param token token
49 * @param finish finish
50 * @param breakLabel break label
51 */
52 protected BreakableNode(final int lineNumber, final long token, final int finish, final Label breakLabel) {
53 super(lineNumber, token, finish);
54 this.breakLabel = breakLabel;
55 }
56
57 /**
58 * Copy constructor
59 *
60 * @param breakableNode source node
61 */
62 protected BreakableNode(final BreakableNode breakableNode) {
63 super(breakableNode);
64 this.breakLabel = new Label(breakableNode.getBreakLabel());
65 }
66
67 @Override
68 public abstract Node ensureUniqueLabels(final LexicalContext lc);
69
70 /**
71 * Check whether this can be broken out from without using a label,
72 * e.g. everything but Blocks, basically
73 * @return true if breakable without label
74 */
75 protected boolean isBreakableWithoutLabel() {
76 return true;
77 }
78
79 /**
80 * Return the break label, i.e. the location to go to on break.
81 * @return the break label
82 */
83 public Label getBreakLabel() {
84 return breakLabel;
85 }
86
87 /**
88 * Return the labels associated with this node. Breakable nodes that
89 * aren't LoopNodes only have a break label - the location immediately
90 * afterwards the node in code
91 * @return list of labels representing locations around this node
92 */
93 public List<Label> getLabels() {
94 return Arrays.asList(breakLabel);
95 }
96
97 }
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