src/share/classes/com/sun/tools/javac/jvm/LVTRanges.java

Thu, 25 Sep 2014 17:09:23 -0700

author
vromero
date
Thu, 25 Sep 2014 17:09:23 -0700
changeset 2572
31d2a837676f
parent 0
959103a6100f
permissions
-rw-r--r--

8058708: java.lang.AssertionError compiling source code
Reviewed-by: jjg

     1 /*
     2  * Copyright (c) 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  */
    26 package com.sun.tools.javac.jvm;
    28 import java.util.Map;
    29 import java.util.Map.Entry;
    30 import java.util.WeakHashMap;
    32 import com.sun.tools.javac.code.Symbol.MethodSymbol;
    33 import com.sun.tools.javac.code.Symbol.VarSymbol;
    34 import com.sun.tools.javac.tree.JCTree;
    35 import com.sun.tools.javac.util.Context;
    36 import com.sun.tools.javac.util.List;
    38 /** This class contains a one to many relation between a tree and a set of variables.
    39  *  The relation implies that the given tree closes the DA (definite assignment)
    40  *  range for the set of variables.
    41  *
    42  *  <p><b>This is NOT part of any supported API.
    43  *  If you write code that depends on this, you do so at your own risk.
    44  *  This code and its internal interfaces are subject to change or
    45  *  deletion without notice.</b>
    46  */
    47 public class LVTRanges {
    48     /** The context key for the LVT ranges. */
    49     protected static final Context.Key<LVTRanges> lvtRangesKey = new Context.Key<>();
    51     /** Get the LVTRanges instance for this context. */
    52     public static LVTRanges instance(Context context) {
    53         LVTRanges instance = context.get(lvtRangesKey);
    54         if (instance == null) {
    55             instance = new LVTRanges(context);
    56         }
    57         return instance;
    58     }
    60     private static final long serialVersionUID = 1812267524140424433L;
    62     protected Context context;
    64     protected Map<MethodSymbol, Map<JCTree, List<VarSymbol>>>
    65             aliveRangeClosingTrees = new WeakHashMap<>();
    67     public LVTRanges(Context context) {
    68         this.context = context;
    69         context.put(lvtRangesKey, this);
    70     }
    72     public List<VarSymbol> getVars(MethodSymbol method, JCTree tree) {
    73         Map<JCTree, List<VarSymbol>> varMap = aliveRangeClosingTrees.get(method);
    74         return (varMap != null) ? varMap.get(tree) : null;
    75     }
    77     public boolean containsKey(MethodSymbol method, JCTree tree) {
    78         Map<JCTree, List<VarSymbol>> varMap = aliveRangeClosingTrees.get(method);
    79         if (varMap == null) {
    80             return false;
    81         }
    82         return varMap.containsKey(tree);
    83     }
    85     public void setEntry(MethodSymbol method, JCTree tree, List<VarSymbol> vars) {
    86         Map<JCTree, List<VarSymbol>> varMap = aliveRangeClosingTrees.get(method);
    87         if (varMap != null) {
    88             varMap.put(tree, vars);
    89         } else {
    90             varMap = new WeakHashMap<>();
    91             varMap.put(tree, vars);
    92             aliveRangeClosingTrees.put(method, varMap);
    93         }
    94     }
    96     public List<VarSymbol> removeEntry(MethodSymbol method, JCTree tree) {
    97         Map<JCTree, List<VarSymbol>> varMap = aliveRangeClosingTrees.get(method);
    98         if (varMap != null) {
    99             List<VarSymbol> result = varMap.remove(tree);
   100             if (varMap.isEmpty()) {
   101                 aliveRangeClosingTrees.remove(method);
   102             }
   103             return result;
   104         }
   105         return null;
   106     }
   108     /* This method should be used for debugging LVT related issues.
   109      */
   110     @Override
   111     public String toString() {
   112         String result = "";
   113         for (Entry<MethodSymbol, Map<JCTree, List<VarSymbol>>> mainEntry: aliveRangeClosingTrees.entrySet()) {
   114             result += "Method: \n" + mainEntry.getKey().flatName() + "\n";
   115             int i = 1;
   116             for (Entry<JCTree, List<VarSymbol>> treeEntry: mainEntry.getValue().entrySet()) {
   117                 result += "    Tree " + i + ": \n" + treeEntry.getKey().toString() + "\n";
   118                 result += "        Variables closed:\n";
   119                 for (VarSymbol var: treeEntry.getValue()) {
   120                     result += "            " + var.toString();
   121                 }
   122                 result += "\n";
   123                 i++;
   124             }
   125         }
   126         return result;
   127     }
   129 }

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