SplitReturn.java revision 1304:4da1c371efcb 
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
26package jdk.nashorn.internal.ir;
27
28import jdk.nashorn.internal.ir.visitor.NodeVisitor;
29
30/**
31 * Synthetic AST node that represents return from a split fragment of a split function for control flow reasons (break
32 * or continue into a target outside the current fragment). It has no JavaScript source representation and only occurs
33 * in synthetic functions created by the split-into-functions transformation. It is different from a return node in
34 * that the return value is irrelevant, and doesn't affect the function's return type calculation.
35 */
36public final class SplitReturn extends Statement {
37    private static final long serialVersionUID = 1L;
38
39    /** The sole instance of this AST node. */
40    public static final SplitReturn INSTANCE = new SplitReturn();
41
42    private SplitReturn() {
43        super(NO_LINE_NUMBER, NO_TOKEN, NO_FINISH);
44    }
45
46    @Override
47    public boolean isTerminal() {
48        return true;
49    }
50
51    @Override
52    public Node accept(final NodeVisitor<? extends LexicalContext> visitor) {
53        return visitor.enterSplitReturn(this) ? visitor.leaveSplitReturn(this) : this;
54    }
55
56    @Override
57    public void toString(final StringBuilder sb, final boolean printType) {
58        sb.append(":splitreturn;");
59    }
60
61    private Object readResolve() {
62        return INSTANCE;
63    }
64}
65