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.junit.Assert; 26 import org.junit.Test; 27 28 import org.graalvm.compiler.debug.Debug; 29 import org.graalvm.compiler.debug.Debug.Scope; 30 import org.graalvm.compiler.debug.DebugDumpScope; 31 import org.graalvm.compiler.nodes.ParameterNode; 32 import org.graalvm.compiler.nodes.StructuredGraph; 33 import org.graalvm.compiler.nodes.StructuredGraph.AllowAssumptions; 34 import org.graalvm.compiler.nodes.memory.FloatingReadNode; 35 import org.graalvm.compiler.nodes.spi.LoweringTool; 36 import org.graalvm.compiler.phases.common.CanonicalizerPhase; 37 import org.graalvm.compiler.phases.common.FloatingReadPhase; 38 import org.graalvm.compiler.phases.common.LoweringPhase; 39 import org.graalvm.compiler.phases.tiers.PhaseContext; 40 41 /* consider 42 * B b = (B) a; 43 * return b.x10; 44 * 45 * With snippets a typecheck is performed and if it was successful, a PiNode is created. 46 * For the read node, however, there is only a dependency to the PiNode, but not to the 47 * typecheck itself. With special crafting, it's possible to get the scheduler moving the 48 * FloatingReadNode before the typecheck. Assuming the object is of the wrong type (here for 49 * example A), an invalid field read is done. 50 * 51 * In order to avoid this situation, an anchor node is introduced in CheckCastSnippts. 52 */ 53 54 public class ReadAfterCheckCastTest extends GraphScheduleTest { 55 56 public static long foo = 0; 57 58 public static class A { 59 60 public long x1; 61 } 62 63 public static class B extends A { 64 65 public long x10; 66 } 67 68 public static long test1Snippet(A a) { 69 if (foo > 4) { 70 B b = (B) a; 71 b.x10 += 1; 72 return b.x10; 73 } else { 74 B b = (B) a; 75 b.x10 += 1; 76 return b.x10; 77 } 78 } 79 80 @Test 81 public void test1() { 82 test("test1Snippet"); 83 } 84 85 @SuppressWarnings("try") 86 private void test(final String snippet) { 87 try (Scope s = Debug.scope("ReadAfterCheckCastTest", new DebugDumpScope(snippet))) { 88 // check shape of graph, with lots of assumptions. will probably fail if graph 89 // structure changes significantly 90 StructuredGraph graph = parseEager(snippet, AllowAssumptions.YES); 91 PhaseContext context = new PhaseContext(getProviders()); 92 CanonicalizerPhase canonicalizer = new CanonicalizerPhase(); 93 new LoweringPhase(canonicalizer, LoweringTool.StandardLoweringStage.HIGH_TIER).apply(graph, context); 94 new FloatingReadPhase().apply(graph); 95 canonicalizer.apply(graph, context); 96 97 Debug.dump(Debug.BASIC_LOG_LEVEL, graph, "After lowering"); 98 99 for (FloatingReadNode node : graph.getNodes(ParameterNode.TYPE).first().usages().filter(FloatingReadNode.class)) { 100 // Checking that the parameter a is not directly used for the access to field 101 // x10 (because x10 must be guarded by the checkcast). 102 Assert.assertTrue(node.getLocationIdentity().isImmutable()); 103 } 104 } catch (Throwable e) { 105 throw Debug.handle(e); 106 } 107 } 108 }