[crac] RFR: 8375044: [CRaC] Structured engine options info [v6]

[Radim Vansa]

On Thu, 22 Jan 2026 07:11:37 GMT, Timofei Pushkin <tpushkin at openjdk.org> wrote:

>> Radim Vansa has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   Fix long line
>
> src/java.base/share/native/libcrexec/crexec.cpp line 187:
> 
>> 185:   OPT(image_location, const char *, nullptr, CRLIB_OPTION_FLAG_CHECKPOINT | CRLIB_OPTION_FLAG_RESTORE, "path", "no default", \
>> 186:     "path to a directory with checkpoint/restore files.") \
>> 187:   OPT(exec_location, const char *, nullptr, CRLIB_OPTION_FLAG_CHECKPOINT | CRLIB_OPTION_FLAG_RESTORE, "path", "no default", \
> 
> Nitpick: by using `"no default"` we don't follow our own recommendation from the API to "use empty string" when there's no default. I'm not sure which version is better.
> 
> I suggested making this nullable to have uniformity across engines (it would be up to the JVM to choose how to present this), but maybe it's indeed better to leave this up to engine devs.

The doc does not say that it should be an empty string when there's no default, only in cases where you'd put `NULL` :) The reason I've stayed with `no default` in here is the presentation: the engine does not parse the declared 'default' value, and when this is printed with `help` it would look better. Although wait a sec, we're not printing this anymore...

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PR Review Comment: https://git.openjdk.org/crac/pull/286#discussion_r2715968411