jdk8-mips64-public/nashorn: src/jdk/nashorn/internal/ir/LoopNode.java@b1a7da25b547 (annotated)

src/jdk/nashorn/internal/ir/LoopNode.java@b1a7da25b547 (annotated)

src/jdk/nashorn/internal/ir/LoopNode.java

Wed, 27 Apr 2016 01:36:41 +0800

author: aoqi
date: Wed, 27 Apr 2016 01:36:41 +0800
changeset 0: b1a7da25b547
child 952: 6d5471a497fb
permissions: -rw-r--r--

Initial load
http://hg.openjdk.java.net/jdk8u/jdk8u/nashorn/
changeset: 1034:4b9cc65dd24d
tag: jdk8u25-b17

 /*
  * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.  Oracle designates this
  * particular file as subject to the "Classpath" exception as provided
  * by Oracle in the LICENSE file that accompanied this code.
  *
  * This code is distributed in the hope that it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  * version 2 for more details (a copy is included in the LICENSE file that
  * accompanied this code).
  *
  * You should have received a copy of the GNU General Public License version
  * 2 along with this work; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  *
  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  */
 package jdk.nashorn.internal.ir;
 import java.util.Arrays;
 import java.util.List;
 import jdk.nashorn.internal.codegen.Label;
 /**
  * A loop node, for example a while node, do while node or for node
  */
 public abstract class LoopNode extends BreakableStatement {
     /** loop continue label. */
     protected final Label continueLabel;
     /** Loop test node, null if infinite */
     protected final Expression test;
     /** Loop body */
     protected final Block body;
     /** Can control flow escape from loop, e.g. through breaks or continues to outer loops? */
     protected final boolean controlFlowEscapes;
     /**
      * Constructor
      *
      * @param lineNumber         lineNumber
      * @param token              token
      * @param finish             finish
      * @param test               test, or null if infinite loop
      * @param body               loop body
      * @param controlFlowEscapes controlFlowEscapes
      */
     protected LoopNode(final int lineNumber, final long token, final int finish, final Expression test, final Block body, final boolean controlFlowEscapes) {
         super(lineNumber, token, finish, new Label("while_break"));
         this.continueLabel = new Label("while_continue");
         this.test = test;
         this.body = body;
         this.controlFlowEscapes = controlFlowEscapes;
     }
     /**
      * Constructor
      *
      * @param loopNode loop node
      * @param test     new test
      * @param body     new body
      * @param controlFlowEscapes controlFlowEscapes
      */
     protected LoopNode(final LoopNode loopNode, final Expression test, final Block body, final boolean controlFlowEscapes) {
         super(loopNode);
         this.continueLabel = new Label(loopNode.continueLabel);
         this.test = test;
         this.body = body;
         this.controlFlowEscapes = controlFlowEscapes;
     }
     @Override
     public abstract Node ensureUniqueLabels(final LexicalContext lc);
     /**
      * Does the control flow escape from this loop, i.e. through breaks or
      * continues to outer loops?
      * @return true if control flow escapes
      */
     public boolean controlFlowEscapes() {
         return controlFlowEscapes;
     }
     @Override
     public boolean isTerminal() {
         if (!mustEnter()) {
             return false;
         }
         //must enter but control flow may escape - then not terminal
         if (controlFlowEscapes) {
             return false;
         }
         //must enter, but body ends with return - then terminal
         if (body.isTerminal()) {
             return true;
         }
         //no breaks or returns, it is still terminal if we can never exit
         return test == null;
     }
     /**
      * Conservative check: does this loop have to be entered?
      * @return true if body will execute at least once
      */
     public abstract boolean mustEnter();
     /**
      * Get the continue label for this while node, i.e. location to go to on continue
      * @return continue label
      */
     public Label getContinueLabel() {
         return continueLabel;
     }
     @Override
     public List<Label> getLabels() {
         return Arrays.asList(breakLabel, continueLabel);
     }
     @Override
     public boolean isLoop() {
         return true;
     }
     /**
      * Get the body for this for node
      * @return the body
      */
     public abstract Block getBody();
     /**
      * @param lc   lexical context
      * @param body new body
      * @return new for node if changed or existing if not
      */
     public abstract LoopNode setBody(final LexicalContext lc, final Block body);
     /**
      * Get the test for this for node
      * @return the test
      */
     public abstract Expression getTest();
     /**
      * Set the test for this for node
      *
      * @param lc lexical context
      * @param test new test
      * @return same or new node depending on if test was changed
      */
     public abstract LoopNode setTest(final LexicalContext lc, final Expression test);
     /**
      * Set the control flow escapes flag for this node.
      * TODO  - integrate this with Lowering in a better way
      *
      * @param lc lexical context
      * @param controlFlowEscapes control flow escapes value
      * @return new loop node if changed otherwise the same
      */
     public abstract LoopNode setControlFlowEscapes(final LexicalContext lc, final boolean controlFlowEscapes);
 }

Mercurial > jdk8-mips64-public > nashorn / annotate

src/jdk/nashorn/internal/ir/LoopNode.java@b1a7da25b547 (annotated)

src/jdk/nashorn/internal/ir/LoopNode.java