Mercurial > hg > truffle
view graal/com.oracle.graal.phases/src/com/oracle/graal/phases/verify/VerifyUsageWithEquals.java @ 9800:2eaac2c3670b
VerifyUsageWithEquals/VerifyPhase: add documentation
author | Bernhard Urban <bernhard.urban@jku.at> |
---|---|
date | Thu, 23 May 2013 12:00:40 +0200 |
parents | 41de6947dbc9 |
children | d1682d1df0a3 |
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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. * * 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.oracle.graal.phases.verify; import com.oracle.graal.api.meta.*; import com.oracle.graal.nodes.*; import com.oracle.graal.nodes.calc.*; import com.oracle.graal.nodes.type.*; import com.oracle.graal.phases.*; /** * For certain types object identity should not be used for object equality check. This phase checks * the correct usage of the given type. Equality checks with == or != (except null checks) results * in an {@link AssertionError}. */ public class VerifyUsageWithEquals extends VerifyPhase { private MetaAccessProvider runtime; private Class<?> klass; public VerifyUsageWithEquals(MetaAccessProvider runtime, Class<?> klass) { this.runtime = runtime; this.klass = klass; } private boolean isAssignableType(ValueNode node) { if (node.stamp() instanceof ObjectStamp) { ResolvedJavaType valueType = runtime.lookupJavaType(klass); ResolvedJavaType nodeType = node.objectStamp().type(); if (nodeType != null && valueType.isAssignableFrom(nodeType)) { return true; } } return false; } private static boolean isNullConstant(ValueNode node) { return node.isConstant() && node.asConstant().isNull(); } private boolean checkUsage(ValueNode x, ValueNode y) { return isAssignableType(x) && !isNullConstant(y); } private static boolean isEqualsMethod(StructuredGraph graph) { Signature signature = graph.method().getSignature(); return graph.method().getName().equals("equals") && signature.getParameterCount(false) == 1 && signature.getParameterKind(0).equals(Kind.Object); } @Override protected boolean verify(StructuredGraph graph) { for (ObjectEqualsNode cn : graph.getNodes().filter(ObjectEqualsNode.class)) { if (!isEqualsMethod(graph)) { // bail out if we compare an object of type klass with == or != (except null checks) assert !(checkUsage(cn.x(), cn.y()) && checkUsage(cn.y(), cn.x())) : "VerifyUsage of " + klass.getName() + ": " + cn.x() + " or " + cn.y() + " in " + graph.method() + " uses object identity. Should use equals() instead."; } } return true; } }