Flexible constructors and switch pattern incompatibility

[Archie Cobbs]

There is an issue with flexible constructors and certain
synthetically-generated try/catch code, for example, when using switch
patterns (where a try/catch for MatchException is sprinkled in).

Please see https://bugs.openjdk.org/browse/JDK-8332106 for an example.

As I understand it, this is due to the same verifier 'uninitializedThis'
restriction that prevents bytecode rewriters from building a synthetic
try/catch around super() calls, even if the catch clause always rethrows.

I may have this muddled, but I believe this restriction disallows an
'uninitializedThis' in a catch clause stack map even if the
'uninitializedThis' is never actually touched. In which case a seemingly
obvious fix for this is to relax the restriction, but that's a JVMS change.

Are there other options?

Thanks,
-Archie

-- 
Archie L. Cobbs
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