1 /*
   2  * Copyright (c) 2014, 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.Ignore;
  29 import jdk.nashorn.internal.ir.visitor.NodeVisitor;
  30 
  31 /**
  32  * Synthetic AST node that represents return from a split fragment of a split function for control flow reasons (break
  33  * or continue into a target outside the current fragment). It has no JavaScript source representation and only occurs
  34  * in synthetic functions created by the split-into-functions transformation. It is different from a return node in
  35  * that the return value is irrelevant, and doesn't affect the function's return type calculation.
  36  */
  37 public final class SplitReturn extends Statement {
  38     private static final long serialVersionUID = 1L;
  39 
  40     /** The sole instance of this AST node. */
  41     @Ignore
  42     public static final SplitReturn INSTANCE = new SplitReturn();
  43 
  44     private SplitReturn() {
  45         super(NO_LINE_NUMBER, NO_TOKEN, NO_FINISH);
  46     }
  47 
  48     @Override
  49     public boolean isTerminal() {
  50         return true;
  51     }
  52 
  53     @Override
  54     public Node accept(final NodeVisitor<? extends LexicalContext> visitor) {
  55         return visitor.enterSplitReturn(this) ? visitor.leaveSplitReturn(this) : this;
  56     }
  57 
  58     @Override
  59     public void toString(final StringBuilder sb, final boolean printType) {
  60         sb.append(":splitreturn;");
  61     }
  62 
  63     private Object readResolve() {
  64         return INSTANCE;
  65     }
  66 }