aoqi@0: /*
aoqi@0:  * Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.
aoqi@0:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
aoqi@0:  *
aoqi@0:  * This code is free software; you can redistribute it and/or modify it
aoqi@0:  * under the terms of the GNU General Public License version 2 only, as
aoqi@0:  * published by the Free Software Foundation.  Oracle designates this
aoqi@0:  * particular file as subject to the "Classpath" exception as provided
aoqi@0:  * by Oracle in the LICENSE file that accompanied this code.
aoqi@0:  *
aoqi@0:  * This code is distributed in the hope that it will be useful, but WITHOUT
aoqi@0:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
aoqi@0:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
aoqi@0:  * version 2 for more details (a copy is included in the LICENSE file that
aoqi@0:  * accompanied this code).
aoqi@0:  *
aoqi@0:  * You should have received a copy of the GNU General Public License version
aoqi@0:  * 2 along with this work; if not, write to the Free Software Foundation,
aoqi@0:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
aoqi@0:  *
aoqi@0:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
aoqi@0:  * or visit www.oracle.com if you need additional information or have any
aoqi@0:  * questions.
aoqi@0:  */
aoqi@0: 
aoqi@0: package com.sun.tools.javac.jvm;
aoqi@0: 
aoqi@0: import java.util.Map;
aoqi@0: import java.util.Map.Entry;
aoqi@0: import java.util.WeakHashMap;
aoqi@0: 
aoqi@0: import com.sun.tools.javac.code.Symbol.MethodSymbol;
aoqi@0: import com.sun.tools.javac.code.Symbol.VarSymbol;
aoqi@0: import com.sun.tools.javac.tree.JCTree;
aoqi@0: import com.sun.tools.javac.util.Context;
aoqi@0: import com.sun.tools.javac.util.List;
aoqi@0: 
aoqi@0: /** This class contains a one to many relation between a tree and a set of variables.
aoqi@0:  *  The relation implies that the given tree closes the DA (definite assignment)
aoqi@0:  *  range for the set of variables.
aoqi@0:  *
aoqi@0:  *  <p><b>This is NOT part of any supported API.
aoqi@0:  *  If you write code that depends on this, you do so at your own risk.
aoqi@0:  *  This code and its internal interfaces are subject to change or
aoqi@0:  *  deletion without notice.</b>
aoqi@0:  */
aoqi@0: public class LVTRanges {
aoqi@0:     /** The context key for the LVT ranges. */
aoqi@0:     protected static final Context.Key<LVTRanges> lvtRangesKey = new Context.Key<>();
aoqi@0: 
aoqi@0:     /** Get the LVTRanges instance for this context. */
aoqi@0:     public static LVTRanges instance(Context context) {
aoqi@0:         LVTRanges instance = context.get(lvtRangesKey);
aoqi@0:         if (instance == null) {
aoqi@0:             instance = new LVTRanges(context);
aoqi@0:         }
aoqi@0:         return instance;
aoqi@0:     }
aoqi@0: 
aoqi@0:     private static final long serialVersionUID = 1812267524140424433L;
aoqi@0: 
aoqi@0:     protected Context context;
aoqi@0: 
aoqi@0:     protected Map<MethodSymbol, Map<JCTree, List<VarSymbol>>>
aoqi@0:             aliveRangeClosingTrees = new WeakHashMap<>();
aoqi@0: 
aoqi@0:     public LVTRanges(Context context) {
aoqi@0:         this.context = context;
aoqi@0:         context.put(lvtRangesKey, this);
aoqi@0:     }
aoqi@0: 
aoqi@0:     public List<VarSymbol> getVars(MethodSymbol method, JCTree tree) {
aoqi@0:         Map<JCTree, List<VarSymbol>> varMap = aliveRangeClosingTrees.get(method);
aoqi@0:         return (varMap != null) ? varMap.get(tree) : null;
aoqi@0:     }
aoqi@0: 
aoqi@0:     public boolean containsKey(MethodSymbol method, JCTree tree) {
aoqi@0:         Map<JCTree, List<VarSymbol>> varMap = aliveRangeClosingTrees.get(method);
aoqi@0:         if (varMap == null) {
aoqi@0:             return false;
aoqi@0:         }
aoqi@0:         return varMap.containsKey(tree);
aoqi@0:     }
aoqi@0: 
aoqi@0:     public void setEntry(MethodSymbol method, JCTree tree, List<VarSymbol> vars) {
aoqi@0:         Map<JCTree, List<VarSymbol>> varMap = aliveRangeClosingTrees.get(method);
aoqi@0:         if (varMap != null) {
aoqi@0:             varMap.put(tree, vars);
aoqi@0:         } else {
aoqi@0:             varMap = new WeakHashMap<>();
aoqi@0:             varMap.put(tree, vars);
aoqi@0:             aliveRangeClosingTrees.put(method, varMap);
aoqi@0:         }
aoqi@0:     }
aoqi@0: 
aoqi@0:     public List<VarSymbol> removeEntry(MethodSymbol method, JCTree tree) {
aoqi@0:         Map<JCTree, List<VarSymbol>> varMap = aliveRangeClosingTrees.get(method);
aoqi@0:         if (varMap != null) {
aoqi@0:             List<VarSymbol> result = varMap.remove(tree);
aoqi@0:             if (varMap.isEmpty()) {
aoqi@0:                 aliveRangeClosingTrees.remove(method);
aoqi@0:             }
aoqi@0:             return result;
aoqi@0:         }
aoqi@0:         return null;
aoqi@0:     }
aoqi@0: 
aoqi@0:     /* This method should be used for debugging LVT related issues.
aoqi@0:      */
aoqi@0:     @Override
aoqi@0:     public String toString() {
aoqi@0:         String result = "";
aoqi@0:         for (Entry<MethodSymbol, Map<JCTree, List<VarSymbol>>> mainEntry: aliveRangeClosingTrees.entrySet()) {
aoqi@0:             result += "Method: \n" + mainEntry.getKey().flatName() + "\n";
aoqi@0:             int i = 1;
aoqi@0:             for (Entry<JCTree, List<VarSymbol>> treeEntry: mainEntry.getValue().entrySet()) {
aoqi@0:                 result += "    Tree " + i + ": \n" + treeEntry.getKey().toString() + "\n";
aoqi@0:                 result += "        Variables closed:\n";
aoqi@0:                 for (VarSymbol var: treeEntry.getValue()) {
aoqi@0:                     result += "            " + var.toString();
aoqi@0:                 }
aoqi@0:                 result += "\n";
aoqi@0:                 i++;
aoqi@0:             }
aoqi@0:         }
aoqi@0:         return result;
aoqi@0:     }
aoqi@0: 
aoqi@0: }