RFR: 8369021: A crash in ConstantPool::klass_at_impl

[David Holmes]

On Thu, 2 Oct 2025 18:19:20 GMT, Jan Kratochvil <jkratochvil at openjdk.org> wrote:

>> src/hotspot/share/prims/jvm.cpp line 1335:
>> 
>>> 1333: 
>>> 1334:   bool inner_is_member = false;
>>> 1335:   Klass* outer_klass = k->compute_enclosing_class(&inner_is_member, CHECK_NULL);
>> 
>> Why not put this change in compute_enclosing_class() instead?
>
> Various other similar methods such as:
> - JVM_GetClassDeclaredFields
> - JVM_GetClassDeclaredMethods
> - JVM_GetClassDeclaredConstructors
> 
> already contain the same code fragment:
> 
>   // Ensure class is linked
>   k->link_class(CHECK_NULL);
> 
> so without some deep thoughts I have added it also to this method where it was missing and causing a crash:
> - JVM_GetDeclaringClass
> 
> Without any real world proof it looked to me the similar pattern is also in:
> - JVM_GetSimpleBinaryName
> 
> I can move it to `InstanceKlass::compute_enclosing_class` although first I would like to find a reproducer = test case.

Various reflection methods have to work on a linked class, but that doesn't mean they all have to. I'm not convinced the true problem has been identified here yet.

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PR Review Comment: https://git.openjdk.org/jdk/pull/27595#discussion_r2401619726