[jdk17] RFR: 8269285: Crash/miscompile in CallGenerator::for_method_handle_inline after JDK-8191998 [v2]

[Aleksey Shipilev]

On Wed, 30 Jun 2021 10:30:53 GMT, Vladimir Ivanov <vlivanov at openjdk.org> wrote:

>> Aleksey Shipilev has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   Just filter signature interfaces
>
> src/hotspot/share/opto/callGenerator.cpp line 1165:
> 
>> 1163:         for (int i = 0, j = 0; i < signature->count(); i++) {
>> 1164:           ciType* t = signature->type_at(i);
>> 1165:           if (t->is_klass()) {
> 
> What I suggested is to extend the guard with `!t->as_klass()->is_interface()` check.

I am not convinced it is safe. At least it does not look safe for JDK 17. The "must" in the comment block above makes me wary about skipping the casting for interfaces...


        // In lambda forms we erase signature types to avoid resolving issues
        // involving class loaders.  When we optimize a method handle invoke
        // to a direct call we must cast the receiver and arguments to its
        // actual types.

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PR: https://git.openjdk.java.net/jdk17/pull/169