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 jdk.nashorn.internal.ir.annotations.Immutable;
29 import jdk.nashorn.internal.ir.visitor.NodeVisitor;
30
31 /**
32 * IR representation for a WHILE statement. This is the superclass of all
33 * loop nodes
34 */
35 @Immutable
36 public final class WhileNode extends LoopNode {
37 private static final long serialVersionUID = 1L;
38
39
40 /** is this a do while node ? */
41 private final boolean isDoWhile;
42
43 /**
44 * Constructor
45 *
46 * @param lineNumber line number
47 * @param token token
48 * @param finish finish
49 * @param isDoWhile is this a do while loop?
50 * @param test test expression
51 * @param body body of the while loop
52 */
53 public WhileNode(final int lineNumber, final long token, final int finish, final boolean isDoWhile, final JoinPredecessorExpression test, final Block body) {
54 super(lineNumber, token, finish, body, test, false);
55 this.isDoWhile = isDoWhile;
56 }
57
58 /**
59 * Internal copy constructor
60 *
61 * @param whileNode while node
62 * @param test Test expression
63 * @param body body of the while loop
64 * @param controlFlowEscapes control flow escapes?
65 * @param conversion local variable conversion info
66 */
67 private WhileNode(final WhileNode whileNode, final JoinPredecessorExpression test, final Block body, final boolean controlFlowEscapes, final LocalVariableConversion conversion) {
68 super(whileNode, test, body, controlFlowEscapes, conversion);
69 this.isDoWhile = whileNode.isDoWhile;
70 }
71
72 @Override
73 public Node ensureUniqueLabels(final LexicalContext lc) {
74 return Node.replaceInLexicalContext(lc, this, new WhileNode(this, test, body, controlFlowEscapes, conversion));
75 }
76
77 @Override
78 public boolean hasGoto() {
79 return test == null;
80 }
81
82 @Override
83 public Node accept(final LexicalContext lc, final NodeVisitor<? extends LexicalContext> visitor) {
84 if (visitor.enterWhileNode(this)) {
85 if (isDoWhile()) {
86 return visitor.leaveWhileNode(
87 setBody(lc, (Block)body.accept(visitor)).
88 setTest(lc, (JoinPredecessorExpression)test.accept(visitor)));
89 }
90 return visitor.leaveWhileNode(
91 setTest(lc, (JoinPredecessorExpression)test.accept(visitor)).
92 setBody(lc, (Block)body.accept(visitor)));
93 }
94 return this;
95 }
96
97 @Override
98 public WhileNode setTest(final LexicalContext lc, final JoinPredecessorExpression test) {
99 if (this.test == test) {
100 return this;
101 }
102 return Node.replaceInLexicalContext(lc, this, new WhileNode(this, test, body, controlFlowEscapes, conversion));
103 }
104
105 @Override
106 public Block getBody() {
107 return body;
108 }
109
110 @Override
111 public WhileNode setBody(final LexicalContext lc, final Block body) {
112 if (this.body == body) {
113 return this;
114 }
115 return Node.replaceInLexicalContext(lc, this, new WhileNode(this, test, body, controlFlowEscapes, conversion));
116 }
117
118 @Override
119 public WhileNode setControlFlowEscapes(final LexicalContext lc, final boolean controlFlowEscapes) {
120 if (this.controlFlowEscapes == controlFlowEscapes) {
121 return this;
122 }
123 return Node.replaceInLexicalContext(lc, this, new WhileNode(this, test, body, controlFlowEscapes, conversion));
124 }
125
126 @Override
127 JoinPredecessor setLocalVariableConversionChanged(final LexicalContext lc, final LocalVariableConversion conversion) {
128 return Node.replaceInLexicalContext(lc, this, new WhileNode(this, test, body, controlFlowEscapes, conversion));
129 }
130
131 /**
132 * Check if this is a do while loop or a normal while loop
133 * @return true if do while
134 */
135 public boolean isDoWhile() {
136 return isDoWhile;
137 }
138
139 @Override
140 public void toString(final StringBuilder sb, final boolean printType) {
141 sb.append("while (");
142 test.toString(sb, printType);
143 sb.append(')');
144 }
145
146 @Override
147 public boolean mustEnter() {
148 if (isDoWhile()) {
149 return true;
150 }
151 return test == null;
152 }
153
154 @Override
155 public boolean hasPerIterationScope() {
156 return false;
157 }
158 }