97 lines
3.7 KiB
Java
97 lines
3.7 KiB
Java
/*
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* Copyright (c) 2020, Oracle and/or its affiliates. All rights reserved.
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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*
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* This code is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 only, as
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* published by the Free Software Foundation.
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*
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* This code is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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* version 2 for more details (a copy is included in the LICENSE file that
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* accompanied this code).
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*
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* You should have received a copy of the GNU General Public License version
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* 2 along with this work; if not, write to the Free Software Foundation,
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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*
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* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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* or visit www.oracle.com if you need additional information or have any
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* questions.
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*/
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/*
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* @test
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* @bug 8237528
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* @summary Verify there are no unnecessary checkcasts and conditions generated
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* for the pattern matching in instanceof.
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* @enablePreview
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* @modules java.base/jdk.internal.classfile.impl
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* @compile NoUnnecessaryCast.java
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* @run main NoUnnecessaryCast
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*/
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import java.lang.classfile.*;
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import java.lang.classfile.attribute.CodeAttribute;
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import java.lang.classfile.constantpool.ConstantPool;
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import java.io.File;
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import java.io.IOException;
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import java.util.Arrays;
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import java.util.stream.Collectors;
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import java.util.stream.StreamSupport;
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public class NoUnnecessaryCast {
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public static void main(String[] args) throws IOException {
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new NoUnnecessaryCast()
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.checkClassFile(new File(System.getProperty("test.classes", "."),
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NoUnnecessaryCast.class.getName() + ".class"));
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}
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void checkClassFile(File file) throws IOException {
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ClassModel classFile = ClassFile.of().parse(file.toPath());
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MethodModel method = classFile.methods().stream()
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.filter(m -> getName(m).equals("test"))
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.findAny()
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.get();
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String expectedInstructions = """
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ALOAD_1
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INSTANCEOF
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IFEQ
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ALOAD_1
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CHECKCAST
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ASTORE_2
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ALOAD_2
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INVOKEVIRTUAL
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IFEQ
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ICONST_1
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GOTO
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ICONST_0
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IRETURN
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""";
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CodeAttribute code = method.findAttribute(Attributes.code()).orElseThrow();
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String actualInstructions = printCode(code);
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if (!expectedInstructions.equals(actualInstructions)) {
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throw new AssertionError("Unexpected instructions found:\n" +
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actualInstructions);
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}
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}
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String printCode(CodeAttribute code) {
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return code.elementList().stream()
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.filter(e -> e instanceof Instruction)
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.map(ins -> ((Instruction) ins).opcode().name())
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.collect(Collectors.joining("\n", "", "\n"));
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}
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String getName(MethodModel m) {
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return m.methodName().stringValue();
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}
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boolean test(Object o) {
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return o instanceof String s && s.isEmpty();
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}
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}
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