1 /*
   2  * Copyright (c) 2019, 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 
  24 
  25 package org.graalvm.compiler.hotspot.test;
  26 
  27 import org.graalvm.compiler.core.test.GraalCompilerTest;
  28 import org.graalvm.compiler.nodes.ConstantNode;
  29 import org.graalvm.compiler.nodes.FixedNode;
  30 import org.graalvm.compiler.nodes.ReturnNode;
  31 import org.graalvm.compiler.nodes.StructuredGraph;
  32 import org.junit.Test;
  33 
  34 import jdk.vm.ci.hotspot.HotSpotObjectConstant;
  35 import jdk.vm.ci.meta.Constant;
  36 import jdk.vm.ci.meta.ResolvedJavaMethod;
  37 import static org.hamcrest.CoreMatchers.instanceOf;
  38 import org.junit.Assert;
  39 
  40 /**
  41  * Tests constant folding of {@link String#intern()}.
  42  */
  43 public class StringInternConstantTest extends GraalCompilerTest {
  44 
  45     private static final String A_CONSTANT_STRING = "a constant string";
  46 
  47     @Test
  48     public void test1() {
  49         ResolvedJavaMethod method = getResolvedJavaMethod("constantIntern");
  50         StructuredGraph graph = parseForCompile(method);
  51 
  52         FixedNode firstFixed = graph.start().next();
  53         Assert.assertThat(firstFixed, instanceOf(ReturnNode.class));
  54 
  55         ReturnNode ret = (ReturnNode) firstFixed;
  56         if (ret.result() instanceof ConstantNode) {
  57             String expected = A_CONSTANT_STRING.intern();
  58             Constant constant = ((ConstantNode) ret.result()).getValue();
  59             if (constant instanceof HotSpotObjectConstant) {
  60                 String returnedString = ((HotSpotObjectConstant) constant).asObject(String.class);
  61                 Assert.assertSame("result", expected, returnedString);
  62             } else {
  63                 Assert.fail("expected HotSpotObjectConstant, got: " + constant.getClass());
  64             }
  65         } else {
  66             Assert.fail("result not constant: " + ret.result());
  67         }
  68     }
  69 
  70     public static String constantIntern() {
  71         return A_CONSTANT_STRING.intern();
  72     }
  73 }