1 /* 2 * Copyright (c) 2013, 2015, 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. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 */ 23 package org.graalvm.compiler.core.test; 24 25 import org.graalvm.compiler.debug.DebugContext; 26 import org.graalvm.compiler.debug.DebugDumpScope; 27 import org.graalvm.compiler.nodes.ParameterNode; 28 import org.graalvm.compiler.nodes.StructuredGraph; 29 import org.graalvm.compiler.nodes.StructuredGraph.AllowAssumptions; 30 import org.graalvm.compiler.nodes.memory.FloatingReadNode; 31 import org.graalvm.compiler.nodes.spi.LoweringTool; 32 import org.graalvm.compiler.phases.common.CanonicalizerPhase; 33 import org.graalvm.compiler.phases.common.FloatingReadPhase; 34 import org.graalvm.compiler.phases.common.LoweringPhase; 35 import org.graalvm.compiler.phases.tiers.PhaseContext; 36 import org.junit.Assert; 37 import org.junit.Test; 38 39 /* consider 40 * B b = (B) a; 41 * return b.x10; 42 * 43 * With snippets a typecheck is performed and if it was successful, a PiNode is created. 44 * For the read node, however, there is only a dependency to the PiNode, but not to the 45 * typecheck itself. With special crafting, it's possible to get the scheduler moving the 46 * FloatingReadNode before the typecheck. Assuming the object is of the wrong type (here for 47 * example A), an invalid field read is done. 48 * 49 * In order to avoid this situation, an anchor node is introduced in CheckCastSnippts. 50 */ 51 52 public class ReadAfterCheckCastTest extends GraphScheduleTest { 53 54 public static long foo = 0; 55 56 public static class A { 57 58 public long x1; 59 } 60 61 public static class B extends A { 62 63 public long x10; 64 } 65 66 public static long test1Snippet(A a) { 67 if (foo > 4) { 68 B b = (B) a; 69 b.x10 += 1; 70 return b.x10; 71 } else { 72 B b = (B) a; 73 b.x10 += 1; 74 return b.x10; 75 } 76 } 77 78 @Test 79 public void test1() { 80 test("test1Snippet"); 81 } 82 83 @SuppressWarnings("try") 84 private void test(final String snippet) { 85 DebugContext debug = getDebugContext(); 86 try (DebugContext.Scope s = debug.scope("ReadAfterCheckCastTest", new DebugDumpScope(snippet))) { 87 // check shape of graph, with lots of assumptions. will probably fail if graph 88 // structure changes significantly 89 StructuredGraph graph = parseEager(snippet, AllowAssumptions.YES); 90 PhaseContext context = new PhaseContext(getProviders()); 91 CanonicalizerPhase canonicalizer = new CanonicalizerPhase(); 92 new LoweringPhase(canonicalizer, LoweringTool.StandardLoweringStage.HIGH_TIER).apply(graph, context); 93 new FloatingReadPhase().apply(graph); 94 canonicalizer.apply(graph, context); 95 96 debug.dump(DebugContext.BASIC_LEVEL, graph, "After lowering"); 97 98 for (FloatingReadNode node : graph.getNodes(ParameterNode.TYPE).first().usages().filter(FloatingReadNode.class)) { 99 // Checking that the parameter a is not directly used for the access to field 100 // x10 (because x10 must be guarded by the checkcast). 101 Assert.assertTrue(node.getLocationIdentity().isImmutable()); 102 } 103 } catch (Throwable e) { 104 throw debug.handle(e); 105 } 106 } 107 }