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src/share/classes/com/sun/tools/javac/jvm/LVTRanges.java@9ca8d8713094 (annotated)

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

Thu, 12 Oct 2017 19:50:01 +0800

author

aoqi

date

Thu, 12 Oct 2017 19:50:01 +0800

changeset 2702

9ca8d8713094

parent 0

959103a6100f

permissions

-rw-r--r--

merge

aoqi@0	1	/*
aoqi@0	2	* Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.
aoqi@0	3	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
aoqi@0	4	*
aoqi@0	5	* This code is free software; you can redistribute it and/or modify it
aoqi@0	6	* under the terms of the GNU General Public License version 2 only, as
aoqi@0	7	* published by the Free Software Foundation. Oracle designates this
aoqi@0	8	* particular file as subject to the "Classpath" exception as provided
aoqi@0	9	* by Oracle in the LICENSE file that accompanied this code.
aoqi@0	10	*
aoqi@0	11	* This code is distributed in the hope that it will be useful, but WITHOUT
aoqi@0	12	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
aoqi@0	13	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
aoqi@0	14	* version 2 for more details (a copy is included in the LICENSE file that
aoqi@0	15	* accompanied this code).
aoqi@0	16	*
aoqi@0	17	* You should have received a copy of the GNU General Public License version
aoqi@0	18	* 2 along with this work; if not, write to the Free Software Foundation,
aoqi@0	19	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
aoqi@0	20	*
aoqi@0	21	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
aoqi@0	22	* or visit www.oracle.com if you need additional information or have any
aoqi@0	23	* questions.
aoqi@0	24	*/
aoqi@0	25
aoqi@0	26	package com.sun.tools.javac.jvm;
aoqi@0	27
aoqi@0	28	import java.util.Map;
aoqi@0	29	import java.util.Map.Entry;
aoqi@0	30	import java.util.WeakHashMap;
aoqi@0	31
aoqi@0	32	import com.sun.tools.javac.code.Symbol.MethodSymbol;
aoqi@0	33	import com.sun.tools.javac.code.Symbol.VarSymbol;
aoqi@0	34	import com.sun.tools.javac.tree.JCTree;
aoqi@0	35	import com.sun.tools.javac.util.Context;
aoqi@0	36	import com.sun.tools.javac.util.List;
aoqi@0	37
aoqi@0	38	/** This class contains a one to many relation between a tree and a set of variables.
aoqi@0	39	* The relation implies that the given tree closes the DA (definite assignment)
aoqi@0	40	* range for the set of variables.
aoqi@0	41	*
aoqi@0	42	* <p><b>This is NOT part of any supported API.
aoqi@0	43	* If you write code that depends on this, you do so at your own risk.
aoqi@0	44	* This code and its internal interfaces are subject to change or
aoqi@0	45	* deletion without notice.</b>
aoqi@0	46	*/
aoqi@0	47	public class LVTRanges {
aoqi@0	48	/** The context key for the LVT ranges. */
aoqi@0	49	protected static final Context.Key<LVTRanges> lvtRangesKey = new Context.Key<>();
aoqi@0	50
aoqi@0	51	/** Get the LVTRanges instance for this context. */
aoqi@0	52	public static LVTRanges instance(Context context) {
aoqi@0	53	LVTRanges instance = context.get(lvtRangesKey);
aoqi@0	54	if (instance == null) {
aoqi@0	55	instance = new LVTRanges(context);
aoqi@0	56	}
aoqi@0	57	return instance;
aoqi@0	58	}
aoqi@0	59
aoqi@0	60	private static final long serialVersionUID = 1812267524140424433L;
aoqi@0	61
aoqi@0	62	protected Context context;
aoqi@0	63
aoqi@0	64	protected Map<MethodSymbol, Map<JCTree, List<VarSymbol>>>
aoqi@0	65	aliveRangeClosingTrees = new WeakHashMap<>();
aoqi@0	66
aoqi@0	67	public LVTRanges(Context context) {
aoqi@0	68	this.context = context;
aoqi@0	69	context.put(lvtRangesKey, this);
aoqi@0	70	}
aoqi@0	71
aoqi@0	72	public List<VarSymbol> getVars(MethodSymbol method, JCTree tree) {
aoqi@0	73	Map<JCTree, List<VarSymbol>> varMap = aliveRangeClosingTrees.get(method);
aoqi@0	74	return (varMap != null) ? varMap.get(tree) : null;
aoqi@0	75	}
aoqi@0	76
aoqi@0	77	public boolean containsKey(MethodSymbol method, JCTree tree) {
aoqi@0	78	Map<JCTree, List<VarSymbol>> varMap = aliveRangeClosingTrees.get(method);
aoqi@0	79	if (varMap == null) {
aoqi@0	80	return false;
aoqi@0	81	}
aoqi@0	82	return varMap.containsKey(tree);
aoqi@0	83	}
aoqi@0	84
aoqi@0	85	public void setEntry(MethodSymbol method, JCTree tree, List<VarSymbol> vars) {
aoqi@0	86	Map<JCTree, List<VarSymbol>> varMap = aliveRangeClosingTrees.get(method);
aoqi@0	87	if (varMap != null) {
aoqi@0	88	varMap.put(tree, vars);
aoqi@0	89	} else {
aoqi@0	90	varMap = new WeakHashMap<>();
aoqi@0	91	varMap.put(tree, vars);
aoqi@0	92	aliveRangeClosingTrees.put(method, varMap);
aoqi@0	93	}
aoqi@0	94	}
aoqi@0	95
aoqi@0	96	public List<VarSymbol> removeEntry(MethodSymbol method, JCTree tree) {
aoqi@0	97	Map<JCTree, List<VarSymbol>> varMap = aliveRangeClosingTrees.get(method);
aoqi@0	98	if (varMap != null) {
aoqi@0	99	List<VarSymbol> result = varMap.remove(tree);
aoqi@0	100	if (varMap.isEmpty()) {
aoqi@0	101	aliveRangeClosingTrees.remove(method);
aoqi@0	102	}
aoqi@0	103	return result;
aoqi@0	104	}
aoqi@0	105	return null;
aoqi@0	106	}
aoqi@0	107
aoqi@0	108	/* This method should be used for debugging LVT related issues.
aoqi@0	109	*/
aoqi@0	110	@Override
aoqi@0	111	public String toString() {
aoqi@0	112	String result = "";
aoqi@0	113	for (Entry<MethodSymbol, Map<JCTree, List<VarSymbol>>> mainEntry: aliveRangeClosingTrees.entrySet()) {
aoqi@0	114	result += "Method: \n" + mainEntry.getKey().flatName() + "\n";
aoqi@0	115	int i = 1;
aoqi@0	116	for (Entry<JCTree, List<VarSymbol>> treeEntry: mainEntry.getValue().entrySet()) {
aoqi@0	117	result += " Tree " + i + ": \n" + treeEntry.getKey().toString() + "\n";
aoqi@0	118	result += " Variables closed:\n";
aoqi@0	119	for (VarSymbol var: treeEntry.getValue()) {
aoqi@0	120	result += " " + var.toString();
aoqi@0	121	}
aoqi@0	122	result += "\n";
aoqi@0	123	i++;
aoqi@0	124	}
aoqi@0	125	}
aoqi@0	126	return result;
aoqi@0	127	}
aoqi@0	128
aoqi@0	129	}