On Fri, 3 Nov 2023 16:26:49 GMT, Jan Lahoda <[email protected]> wrote:
> For code like:
>
> enum E {A {}, B {} }
> Object o = E.A;
> switch (o) {
> case E.A -> System.err.println(o);
> default -> System.err.println("default");
> }
>
>
> The result is `default`, not `A`, due to incorrect classes being compared.
> Thanks for @liach for noting the solution here:
> https://github.com/openjdk/jdk/pull/16489#discussion_r1381411165
Marked as reviewed by liach (Author).
src/java.base/share/classes/java/lang/runtime/SwitchBootstraps.java line 399:
> 397: Class<?> clazz =
> label.constantType().resolveConstantDesc(lookup);
> 398:
> 399: if (!(value instanceof Enum<?> enumValue) ||
Minor comment: If we are more concerned about performance when the enum is in a
mix-and-match with other types (say primitives etc.), we can move the
`instanceof` test before the `constantType().resolveConstantDesc()` to avoid a
Class lookup.
-------------
PR Review: https://git.openjdk.org/jdk/pull/16499#pullrequestreview-1713656471
PR Review Comment: https://git.openjdk.org/jdk/pull/16499#discussion_r1382291935
