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