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 java.util.List;
  29 import jdk.nashorn.internal.ir.visitor.NodeVisitor;
  30 
  31 /**
  32  * Represents a block used as a statement.
  33  */
  34 public class BlockStatement extends Statement {
  35     private static final long serialVersionUID = 1L;
  36 
  37     /** Block to execute. */
  38     private final Block block;
  39     /** is this a synthetic block? */
  40     private boolean synthetic;
  41 
  42     /**
  43      * Constructor
  44      *
  45      * @param block the block to execute
  46      */
  47     public BlockStatement(final Block block) {
  48         this(block.getFirstStatementLineNumber(), block, true);
  49     }
  50 
  51     /**
  52      * Constructor
  53      *
  54      * @param lineNumber line number
  55      * @param block the block to execute
  56      */
  57     public BlockStatement(final int lineNumber, final Block block, final boolean synthetic) {
  58         super(lineNumber, block.getToken(), block.getFinish());
  59         this.block = block;
  60         this.synthetic = synthetic;
  61     }
  62 
  63     private BlockStatement(final BlockStatement blockStatement, final Block block, final boolean synthetic) {
  64         super(blockStatement);
  65         this.block = block;
  66         this.synthetic = synthetic;
  67     }
  68 
  69     /**
  70      * Use this method to create a block statement meant to replace a single statement.
  71      * @param stmt the statement to replace
  72      * @param newStmts the statements for the new block statement
  73      * @return a block statement with the new statements. It will have the line number, token, and finish of the
  74      * original statement.
  75      */
  76     public static BlockStatement createReplacement(final Statement stmt, final List<Statement> newStmts) {
  77         return createReplacement(stmt, stmt.getFinish(), newStmts);
  78     }
  79 
  80     /**
  81      * Use this method to create a block statement meant to replace a single statement.
  82      * @param stmt the statement to replace
  83      * @param finish the new finish for the block
  84      * @param newStmts the statements for the new block statement
  85      * @return a block statement with the new statements. It will have the line number, and token of the
  86      * original statement.
  87      */
  88     public static BlockStatement createReplacement(final Statement stmt, final int finish, final List<Statement> newStmts) {
  89         return new BlockStatement(stmt.getLineNumber(), new Block(stmt.getToken(), finish, newStmts), true);
  90     }
  91 
  92     @Override
  93     public boolean isTerminal() {
  94         return block.isTerminal();
  95     }
  96 
  97     public boolean isSynthetic() {
  98         return synthetic;
  99     }
 100 
 101     @Override
 102     public Node accept(final NodeVisitor<? extends LexicalContext> visitor) {
 103         if (visitor.enterBlockStatement(this)) {
 104             return visitor.leaveBlockStatement(setBlock((Block)block.accept(visitor)));
 105         }
 106 
 107         return this;
 108     }
 109 
 110     @Override
 111     public void toString(final StringBuilder sb, final boolean printType) {
 112         block.toString(sb, printType);
 113     }
 114 
 115     /**
 116      * Return the block to be executed
 117      * @return the block
 118      */
 119     public Block getBlock() {
 120         return block;
 121     }
 122 
 123     /**
 124      * Reset the block to be executed
 125      * @param block the block
 126      * @return new or same execute node
 127      */
 128     public BlockStatement setBlock(final Block block) {
 129         if (this.block == block) {
 130             return this;
 131         }
 132         return new BlockStatement(this, block, synthetic);
 133     }
 134 }