Statement.java revision 1068:34ef988d5959 
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
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24 */
25
26package jdk.nashorn.internal.ir;
27
28/**
29 * Statement is something that becomes code and can be stepped past. A block is
30 * made up of statements. The only node subclass that needs to keep token and
31 * location information is the Statement
32 */
33public abstract class Statement extends Node implements Terminal {
34    private static final long serialVersionUID = 1L;
35
36    private final int lineNumber;
37
38    /**
39     * Constructor
40     *
41     * @param lineNumber line number
42     * @param token      token
43     * @param finish     finish
44     */
45    public Statement(final int lineNumber, final long token, final int finish) {
46        super(token, finish);
47        this.lineNumber = lineNumber;
48    }
49
50    /**
51     * Constructor
52     *
53     * @param lineNumber line number
54     * @param token      token
55     * @param start      start
56     * @param finish     finish
57     */
58    protected Statement(final int lineNumber, final long token, final int start, final int finish) {
59        super(token, start, finish);
60        this.lineNumber = lineNumber;
61    }
62
63    /**
64     * Copy constructor
65     *
66     * @param node source node
67     */
68    protected Statement(final Statement node) {
69        super(node);
70        this.lineNumber = node.lineNumber;
71    }
72
73    /**
74     * Return the line number
75     * @return line number
76     */
77    public int getLineNumber() {
78        return lineNumber;
79    }
80
81    /**
82     * Is this a terminal statement, i.e. does it end control flow like a throw or return?
83     *
84     * @return true if this node statement is terminal
85     */
86    @Override
87    public boolean isTerminal() {
88        return false;
89    }
90
91    /**
92     * Check if this statement repositions control flow with goto like
93     * semantics, for example {@link BreakNode} or a {@link ForNode} with no test
94     * @return true if statement has goto semantics
95     */
96    public boolean hasGoto() {
97        return false;
98    }
99
100    /**
101     * Check if this statement has terminal flags, i.e. ends or breaks control flow
102     *
103     * @return true if has terminal flags
104     */
105    public final boolean hasTerminalFlags() {
106        return isTerminal() || hasGoto();
107    }
108}
109
110