RFR (XXS): 8029366: ShouldNotReachHere error when creating an array with component type of void

[Christian Thalinger]

For small ones like this I don’t bother creating a webrev.  The patch is archived in the mailing list archive anyway.

Thanks for the review.

On Dec 6, 2013, at 10:41 AM, Vladimir Kozlov <vladimir.kozlov at oracle.com> wrote:

> What happened with webrevs in cr.openjdk?
> 
> Looks fine to me.
> 
> Thanks,
> Vladimir
> 
> On 12/6/13 9:05 AM, Christian Thalinger wrote:
>> https://bugs.openjdk.java.net/browse/JDK-8029366
>> 
>> 8029366: ShouldNotReachHere error when creating an array with component type of void
>> 
>> The code in LoadNode::klass_value_common tries to create a ciArrayKlass of type T_VOID which fails since there is no
>> such thing as a void array.
>> 
>> Primitive classes have null for a klass field. For the non-array case we return null but for the array case we don't and
>> so we hit an assert in ciArrayKlass::make.
>> 
>> The fix is to check for void types in the array case and return TypePtr::NULL_PTR.
>> 
>> diff -r 55dd6e77b399 src/share/vm/opto/memnode.cpp
>> --- a/src/share/vm/opto/memnode.cppFri Nov 22 15:26:37 2013 +0100
>> +++ b/src/share/vm/opto/memnode.cppFri Dec 06 09:04:15 2013 -0800
>> @@ -2071,6 +2071,11 @@ const Type *LoadNode::klass_value_common
>>        if (t != NULL) {
>>          // constant oop => constant klass
>>          if (offset == java_lang_Class::array_klass_offset_in_bytes()) {
>> +          if (t->is_void()) {
>> +            // We cannot create a void array.  Since void is a primitive type return null
>> +            // klass.  Users of this result need to do a null check on the returned klass.
>> +            return TypePtr::NULL_PTR;
>> +          }
>>            return TypeKlassPtr::make(ciArrayKlass::make(t));
>>          }
>>          if (!t->is_klass()) {
>> diff -r 55dd6e77b399 test/compiler/reflection/ArrayNewInstanceOfVoid.java
>> --- /dev/nullThu Jan 01 00:00:00 1970 +0000
>> +++ b/test/compiler/reflection/ArrayNewInstanceOfVoid.javaFri Dec 06 09:04:15 2013 -0800
>> @@ -0,0 +1,44 @@
>> +/*
>> + * Copyright (c) 2013, 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 <http://www.oracle.com> if you need additional information or have any
>> + * questions.
>> + */
>> +
>> +/*
>> + * @test
>> + * @bug 8029366
>> + * @summary ShouldNotReachHere error when creating an array with component type of void
>> + */
>> +
>> +public class ArrayNewInstanceOfVoid {
>> +    public static void main(String[] args) {
>> +        for (int i = 0; i < 100_000; i++) {
>> +            test();
>> +        }
>> +    }
>> +
>> +    private static void test() {
>> +        try {
>> +            java.lang.reflect.Array.newInstance(void.class, 2);
>> +        } catch (IllegalArgumentException e) {
>> +            // expected
>> +        }
>> +    }
>> +}