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
26package jdk.nashorn.internal.ir;
27
28import jdk.nashorn.internal.ir.annotations.Immutable;
29import jdk.nashorn.internal.ir.visitor.NodeVisitor;
30
31/**
32 * IR representation for a labeled statement. It implements JoinPredecessor to hold conversions that need to be effected
33 * when the block exits normally, but is also targeted by a break statement that might bring different local variable
34 * types to the join at the break point.
35 */
36@Immutable
37public final class LabelNode extends LexicalContextStatement implements JoinPredecessor {
38    private static final long serialVersionUID = 1L;
39
40    /** Label ident. */
41    private final String labelName;
42
43    /** Statements. */
44    private final Block body;
45
46    private final LocalVariableConversion localVariableConversion;
47
48    /**
49     * Constructor
50     *
51     * @param lineNumber line number
52     * @param token      token
53     * @param finish     finish
54     * @param labelName  label name
55     * @param body       body of label node
56     */
57    public LabelNode(final int lineNumber, final long token, final int finish, final String labelName, final Block body) {
58        super(lineNumber, token, finish);
59
60        this.labelName = labelName;
61        this.body  = body;
62        this.localVariableConversion = null;
63    }
64
65    private LabelNode(final LabelNode labelNode, final String labelName, final Block body, final LocalVariableConversion localVariableConversion) {
66        super(labelNode);
67        this.labelName = labelName;
68        this.body = body;
69        this.localVariableConversion = localVariableConversion;
70    }
71
72    @Override
73    public boolean isTerminal() {
74        return body.isTerminal();
75    }
76
77    @Override
78    public Node accept(final LexicalContext lc, final NodeVisitor<? extends LexicalContext> visitor) {
79        if (visitor.enterLabelNode(this)) {
80            return visitor.leaveLabelNode(setBody(lc, (Block)body.accept(visitor)));
81        }
82
83        return this;
84    }
85
86    @Override
87    public void toString(final StringBuilder sb, final boolean printType) {
88        sb.append(labelName).append(':');
89    }
90
91    /**
92     * Get the body of the node
93     * @return the body
94     */
95    public Block getBody() {
96        return body;
97    }
98
99    /**
100     * Reset the body of the node
101     * @param lc lexical context
102     * @param body new body
103     * @return new for node if changed or existing if not
104     */
105    public LabelNode setBody(final LexicalContext lc, final Block body) {
106        if (this.body == body) {
107            return this;
108        }
109        return Node.replaceInLexicalContext(lc, this, new LabelNode(this, labelName, body, localVariableConversion));
110    }
111
112    /**
113     * Get the label name
114     * @return the label
115     */
116    public String getLabelName() {
117        return labelName;
118    }
119
120    @Override
121    public LocalVariableConversion getLocalVariableConversion() {
122        return localVariableConversion;
123    }
124
125    @Override
126    public LabelNode setLocalVariableConversion(final LexicalContext lc, final LocalVariableConversion localVariableConversion) {
127        if(this.localVariableConversion == localVariableConversion) {
128            return this;
129        }
130        return Node.replaceInLexicalContext(lc, this, new LabelNode(this, labelName, body, localVariableConversion));
131    }
132}
133