As discussed in [RFC] Removing MCJIT and RuntimeDyld I think we should start planning to remove MCJIT and RuntimeDyld from LLVM. As a first step towards this I propose that we add deprecation warnings to MCJIT and RuntimeDyld in LLVM 20. This will provide MCJIT and RuntimeDyld clients advanced warning of the removal, encourage them to migrate to ORC/JITLink, and help them to find and contribute to the removal discussion.
I think this is probably uncontroversial, so I will go ahead and add these warnings in a week or so unless anyone objects?
I’m supportive of adding a deprecation warning to prevent folks from adopting MCJIT and giving existing users a heads up.
Since we know that LLDB will be affected and it will be a non-trivial amount of work to move to ORC, can we do this in such a way that we don’t end up with a bunch of warnings when building LLDB in the meantime?
Absolutely. I expect that it will still be some time before we’re actually in a position to remove MCJIT and we definitely want LLDB to build warning clean in the mean time.