com.sun.tools.javac.jvm.LVTRanges Maven / Gradle / Ivy
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/*
* Copyright (c) 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 com.sun.tools.javac.jvm;
import java.util.Map;
import java.util.Map.Entry;
import java.util.WeakHashMap;
import com.sun.tools.javac.code.Symbol.MethodSymbol;
import com.sun.tools.javac.code.Symbol.VarSymbol;
import com.sun.tools.javac.tree.JCTree;
import com.sun.tools.javac.util.Context;
import com.sun.tools.javac.util.List;
/** This class contains a one to many relation between a tree and a set of variables.
* The relation implies that the given tree closes the DA (definite assignment)
* range for the set of variables.
*
* This is NOT part of any supported API.
* If you write code that depends on this, you do so at your own risk.
* This code and its internal interfaces are subject to change or
* deletion without notice.
*/
public class LVTRanges {
/** The context key for the LVT ranges. */
protected static final Context.Key lvtRangesKey = new Context.Key<>();
/** Get the LVTRanges instance for this context. */
public static LVTRanges instance(Context context) {
LVTRanges instance = context.get(lvtRangesKey);
if (instance == null) {
instance = new LVTRanges(context);
}
return instance;
}
private static final long serialVersionUID = 1812267524140424433L;
protected Context context;
protected Map>>
aliveRangeClosingTrees = new WeakHashMap<>();
public LVTRanges(Context context) {
this.context = context;
context.put(lvtRangesKey, this);
}
public List getVars(MethodSymbol method, JCTree tree) {
Map> varMap = aliveRangeClosingTrees.get(method);
return (varMap != null) ? varMap.get(tree) : null;
}
public boolean containsKey(MethodSymbol method, JCTree tree) {
Map> varMap = aliveRangeClosingTrees.get(method);
if (varMap == null) {
return false;
}
return varMap.containsKey(tree);
}
public void setEntry(MethodSymbol method, JCTree tree, List vars) {
Map> varMap = aliveRangeClosingTrees.get(method);
if (varMap != null) {
varMap.put(tree, vars);
} else {
varMap = new WeakHashMap<>();
varMap.put(tree, vars);
aliveRangeClosingTrees.put(method, varMap);
}
}
public List removeEntry(MethodSymbol method, JCTree tree) {
Map> varMap = aliveRangeClosingTrees.get(method);
if (varMap != null) {
List result = varMap.remove(tree);
if (varMap.isEmpty()) {
aliveRangeClosingTrees.remove(method);
}
return result;
}
return null;
}
/* This method should be used for debugging LVT related issues.
*/
@Override
public String toString() {
String result = "";
for (Entry>> mainEntry: aliveRangeClosingTrees.entrySet()) {
result += "Method: \n" + mainEntry.getKey().flatName() + "\n";
int i = 1;
for (Entry> treeEntry: mainEntry.getValue().entrySet()) {
result += " Tree " + i + ": \n" + treeEntry.getKey().toString() + "\n";
result += " Variables closed:\n";
for (VarSymbol var: treeEntry.getValue()) {
result += " " + var.toString();
}
result += "\n";
i++;
}
}
return result;
}
}