RFR: 8371155: Type annotations on local variables are classified after the local var initializer has been type checked

[Vicente Romero]

On Thu, 26 Feb 2026 17:51:40 GMT, Jan Lahoda <jlahoda at openjdk.org> wrote:

>> src/jdk.compiler/share/classes/com/sun/tools/javac/code/TypeAnnotations.java line 490:
>> 
>>> 488:                 alternatives.add(res);
>>> 489:                 alternatives.addAll(ut.alternatives_field.tail);
>>> 490:                 return new UnionClassType((ClassType) ut.getLub(), alternatives.toList());
>> 
>> question: so the type of a union type could be different depending on the presence or not of type annotations?
>
> The idea is that the "unified" type would be the same (getting `ut.getLub()` from the original type), but the first alternative would be enhanced with the type annotation, as is done for ordinary `ClassType`.
> 
> There's `type.tsym.type` conversions happening here (the `UnionClassType` will keep `type.tsym`, and `getLub` will do `tsym.type`), but given exceptions cannot be generic, it seems the type after this cascade should be the same as before it(?).

got it, thanks

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PR Review Comment: https://git.openjdk.org/jdk/pull/29817#discussion_r2860811735