RFR: 8355536: Create version constants to model preview language and vm features [v2]

[Chen Liang]

On Sun, 4 May 2025 18:46:02 GMT, Luca Kellermann <duke at openjdk.org> wrote:

>> Chen Liang has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains four commits:
>> 
>>  - Don't need to update latestSupported later
>>    
>>  - Merge branch 'pr/25015' of https://github.com/openjdk/jdk into feature/preview-cffv
>>  - Add advanced testing for different latestSupported
>>    
>>  - 8355536: Create version constants to model preview language and vm features
>
> src/java.base/share/classes/java/lang/reflect/ClassFileFormatVersion.java line 413:
> 
>> 411:      * ensure the program is compatible with future Java SE releases.
>> 412:      * <p>
>> 413:      * This is a reflective preview API to allows tools running in Java runtime
> 
> Suggestion:
> 
>      * This is a reflective preview API that allows tools running in Java runtime

Don't know why you recommend this, but this aims to explain why this API is reflective preview API instead of an essential preview API (that does not have `reflective = true`). Particular tools wish to perform this specific check, like `javap`; otherwise, I would have marked this as non-reflective, and tools must resort to a third-party knowledge pool to parse preview features related to the current release.

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PR Review Comment: https://git.openjdk.org/jdk/pull/25017#discussion_r2072704486