1/*
2 * Copyright (c) 2016, 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 */
23package org.graalvm.compiler.replacements.test;
24
25import org.graalvm.compiler.core.test.GraalCompilerTest;
26import org.graalvm.compiler.nodes.ConstantNode;
27import org.graalvm.compiler.nodes.FixedNode;
28import org.graalvm.compiler.nodes.ReturnNode;
29import org.graalvm.compiler.nodes.StructuredGraph;
30import org.graalvm.compiler.nodes.ValueNode;
31import jdk.vm.ci.meta.JavaConstant;
32import org.junit.Test;
33
34import jdk.vm.ci.meta.ResolvedJavaMethod;
35import static org.hamcrest.CoreMatchers.instanceOf;
36import org.junit.Assert;
37
38/**
39 * Tests constant folding of string equality.
40 */
41public class StringEqualsConstantTest extends GraalCompilerTest {
42
43    private ValueNode asConstant(StructuredGraph graph, String str) {
44        return ConstantNode.forConstant(getSnippetReflection().forObject(str), getMetaAccess(), graph);
45    }
46
47    private void testStringEquals(String s0, String s1) {
48        ResolvedJavaMethod method = getResolvedJavaMethod("stringEquals");
49        StructuredGraph graph = parseForCompile(method);
50
51        graph.getParameter(0).replaceAndDelete(asConstant(graph, s0));
52        graph.getParameter(1).replaceAndDelete(asConstant(graph, s1));
53
54        compile(method, graph);
55
56        FixedNode firstFixed = graph.start().next();
57        Assert.assertThat(firstFixed, instanceOf(ReturnNode.class));
58
59        ReturnNode ret = (ReturnNode) firstFixed;
60        JavaConstant result = ret.result().asJavaConstant();
61        if (result == null) {
62            Assert.fail("result not constant: " + ret.result());
63        } else {
64            int expected = s0.equals(s1) ? 1 : 0;
65            Assert.assertEquals("result", expected, result.asInt());
66        }
67    }
68
69    @Test
70    public void testSameString() {
71        String s = "equal-string";
72        testStringEquals(s, s);
73    }
74
75    @Test
76    public void testEqualString() {
77        String s = "equal-string";
78        testStringEquals(s, new String(s.toCharArray()));
79    }
80
81    @Test
82    public void testDifferentString() {
83        testStringEquals("some-string", "different-string");
84    }
85
86    @Test
87    public void testSameLengthString() {
88        testStringEquals("string-1", "string-2");
89    }
90
91    public static boolean stringEquals(String a, String b) {
92        return a.equals(b);
93    }
94}
95