[crac] RFR: 8376959: [CRaC] Turn simengine into shared library [v8]

[Timofei Pushkin]

On Fri, 6 Feb 2026 14:58:25 GMT, Radim Vansa <rvansa at openjdk.org> wrote:

>> src/java.base/share/native/libcrcommon/crcommon.hpp line 74:
>> 
>>> 72:   void *image_constraints;
>>> 73:   void *image_score;
>>> 74: };
>> 
>> Since we want to use the C layer a more conventional way seems to be to move this definition to `crcommon.cpp` (it can even become a normal class with a constructor/destructor) and use composition instead of inheritance (engine classes would be `struct crlib_conf`s themselves, `bool init_conf(conf_t* conf, ...)` would become `conf_t* create_conf(...)`). These fields are not used directly anywhere except `crcommon.cpp` anyway.
>> 
>> Otherwise the fields can at least become their actual types to remove the casts in `crcommon.cpp`.
>
> I want to keep the full extension definition in crcommon and with that I won't avoid either inheritance, or globally set function: in crcommon I need to be able to translate `crlib_conf_t` into `conf_t`. Which way would you prefer?

Ah, I see, extension methods require `crlib_conf_t`. Ok, let's keep the inheritance.

Field types can be improved anyway though:

class ImageConstraints;
class ImageScore;

struct crlib_conf {
  ImageConstraints* image_constraints;
  ImageScore* image_score;
};

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PR Review Comment: https://git.openjdk.org/crac/pull/289#discussion_r2781241183