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 import jdk.nashorn.internal.parser.TokenType; 31 32 /** 33 * IR representation for executing bare expressions. Basically, an expression 34 * node means "this code will be executed" and evaluating it results in 35 * statements being added to the IR 36 */ 37 @Immutable 38 public final class ExpressionStatement extends Statement { 39 private static final long serialVersionUID = 1L; 40 41 /** Expression to execute. */ 42 private final Expression expression; 43 private final TokenType destructuringDecl; 44 45 /** 46 * Constructor 47 * 48 * @param lineNumber line number 49 * @param token token 50 * @param finish finish 51 * @param expression the expression to execute 52 * @param destructuringDecl does this statement represent a destructuring declaration? 53 */ 54 public ExpressionStatement(final int lineNumber, final long token, final int finish, 55 final Expression expression, final TokenType destructuringDecl) { 56 super(lineNumber, token, finish); 57 this.expression = expression; 58 this.destructuringDecl = destructuringDecl; 59 } 60 61 /** 62 * Constructor 63 * 64 * @param lineNumber line number 65 * @param token token 66 * @param finish finish 67 * @param expression the expression to execute 68 */ 69 public ExpressionStatement(final int lineNumber, final long token, final int finish, final Expression expression) { 70 this(lineNumber, token, finish, expression, null); 71 } 72 73 private ExpressionStatement(final ExpressionStatement expressionStatement, final Expression expression) { 74 super(expressionStatement); 75 this.expression = expression; 76 this.destructuringDecl = null; 77 } 78 79 @Override 80 public Node accept(final NodeVisitor<? extends LexicalContext> visitor) { 81 if (visitor.enterExpressionStatement(this)) { 82 return visitor.leaveExpressionStatement(setExpression((Expression)expression.accept(visitor))); 83 } 84 85 return this; 86 } 87 88 @Override 89 public void toString(final StringBuilder sb, final boolean printTypes) { 90 expression.toString(sb, printTypes); 91 } 92 93 /** 94 * Return the expression to be executed 95 * @return the expression 96 */ 97 public Expression getExpression() { 98 return expression; 99 } 100 101 /** 102 * Return declaration type if this expression statement is a destructuring declaration 103 * 104 * @return declaration type (LET, VAR, CONST) if destructuring declaration, null otherwise. 105 */ 106 public TokenType destructuringDeclarationType() { 107 return destructuringDecl; 108 } 109 110 /** 111 * Reset the expression to be executed 112 * @param expression the expression 113 * @return new or same execute node 114 */ 115 public ExpressionStatement setExpression(final Expression expression) { 116 if (this.expression == expression) { 117 return this; 118 } 119 return new ExpressionStatement(this, expression); 120 } 121 }