Hi Ryan, is there a use case where people call getEnumConstants() and access a fixed index of array element?
This is so far the only use case I can think of that would be negatively impacted by the lack of constant folding for this method. In addition, I do not recommend adding more @Stable - we should consider better representations like LazyConstant. Regards ________________________________ From: core-libs-dev <[email protected]> on behalf of Ryan Hallock <[email protected]> Sent: Thursday, February 12, 2026 3:45 PM To: [email protected] <[email protected]> Subject: Add @Stable to Class#enumConstants. Hello, I am new to OpenJDK development and I want to propose changes to Class#enumConstants from Class#getEnumConstants()/Class#getSharedEnumConstants(). Currently consider the following example: ```java enum E { A, B, C } E[] values = E.values(); E[] constants = E.class.getEnumConstants(); assert Arrays.equals(values, constants); ``` These methods provide an equal array of values, but they are treated differently. This is because the _constants_ stored by Class#enumConstants are non final and declared volatile. So C2 can't trust this call. Consider if I only wanted to access the value from an offset from these arrays. ```java E value = values[0]; E constant = constants[0]; assert value == constant; ``` _constant_ would never be folded but _value_ would be. So I propose the addition of @Stable annotation added to Class#enumConstants so _constant_ can be folded by C2. This is not a trivial change as it requires changing the data race to abide by @Stable. Could I be sponsored for this change (JBS issue as well)? A future proposal would be adding @Stable to Class#enumConstantDirectory, though that can be a seperate enhancement as that might require changing of the data structure to allow folding. Let me know if it should be combined as the Stable annotation itself would be implemented in a similar way for both. Thanks, Ryan Hallock
