RFR: 8372045: AOT assembly phase asserts with old class if AOT class linking is disabled

[Ioi Lam]

On Tue, 18 Nov 2025 07:44:39 GMT, Aleksey Shipilev <shade at openjdk.org> wrote:

>> Old classes should be stored in the AOT cache only if `CDSConfig::is_preserving_verification_constraints() == true`. However, we miss this check in the AOT assembly phase: the `this` class is loaded from the AOT configuration file, which is a special type of AOT cache, so `AOTMetaspace::in_aot_cache(this)` returns true:
>> 
>> 
>> bool InstanceKlass::can_be_verified_at_dumptime() const {
>>   if (AOTMetaspace::in_aot_cache(this)) {
>>     // This is a class that was dumped into the base archive, so we know
>>     // it was verified at dump time.
>>     return true;
>>   }
>> 
>> 
>> The fix is
>> 
>>  ```
>> bool InstanceKlass::can_be_verified_at_dumptime() const {
>>   if (CDSConfig::is_dumping_dynamic_archive() && AOTMetaspace::in_aot_cache(this)) {
>> 
>> 
>> as this check is intended to be used only when dumping the dynamic archive.
>> 
>> This bug was found when running a complex application (specJBB) but I created a simple reproducer (OldClassSupport2.java).
>
> Marked as reviewed by shade (Reviewer).

Thanks @shipilev @mgronlun for the review

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PR Comment: https://git.openjdk.org/jdk/pull/28365#issuecomment-3548946436