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 /**
  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  */
  33 public 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