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/*
* Copyright (c) 2014, 2024, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
/*
* @test
* @bug 8015499
* @summary javac, Gen is generating extra checkcast instructions in some corner cases
* @modules jdk.compiler/com.sun.tools.javac.util
* @run main DoubleCastTest
*/
import java.util.List;
import java.util.ArrayList;
import java.util.Objects;
import java.lang.classfile.*;
import java.lang.classfile.attribute.CodeAttribute;
import java.lang.classfile.constantpool.ClassEntry;
import java.lang.classfile.instruction.TypeCheckInstruction;
import com.sun.tools.javac.util.Assert;
public class DoubleCastTest {
class C {
Object x;
Object m() { return null; }
void m1(byte[] b) {}
void m2() {
Object o;
Object[] os = null;
m1((byte[])(o = null));
m1((byte[])o);
m1((byte[])(o == null ? o : o));
m1((byte[])m());
m1((byte[])os[0]);
m1((byte[])this.x);
m1((byte[])((byte []) (o = null)));
}
}
public static void main(String... cmdline) throws Exception {
ClassModel cls = ClassFile.of().parse(Objects.requireNonNull(DoubleCastTest.class.getResourceAsStream("DoubleCastTest$C.class")).readAllBytes());
for (MethodModel m: cls.methods())
check(m);
}
static void check(MethodModel m) throws Exception {
boolean last_is_cast = false;
ClassEntry last_ref = null;
CodeAttribute ea = m.findAttribute(Attributes.code()).orElseThrow();
for (int i = 0; i < ea.elementList().size(); ++i) {
CodeElement ce = ea.elementList().get(i);
if (ce instanceof TypeCheckInstruction ins && ins.opcode() == Opcode.CHECKCAST) {
Assert.check
(!(last_is_cast && last_ref == ins.type()),
"Double cast found - Test failed");
last_is_cast = true;
last_ref = ins.type();
} else {
last_is_cast = false;
}
}
}
}
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