Maja Kądziołka (Mar 02 2023 at 11:43): Maja Kądziołka (Mar 02 2023 at 11:43):Hi! I was considering using cranelift's acyclic egraph code for an independent project of mine. I found the cranelift-egraph crate, then looked at the API exposed and went "hold on, there's no way this is sound", and while getting ready to report a bug, I noticed that the crate got refactored out of existence, and the version on crates.io is just a stale snapshot from a while ago. Not ideal, but not sure what the best thing to do about it would be...
bjorn3 (Mar 02 2023 at 14:22):Cranelift-egraph was merged into cranelift-codegen.
Maja Kądziołka (Mar 02 2023 at 15:01):Yeah, it'd be a good idea to mark the crate as deprecated on crates.io or something
Maja Kądziołka (Mar 02 2023 at 15:04):It seems that BumpArena itself, which was unsound, doesn't exist anymore at all?
Chris Fallin (Mar 02 2023 at 16:21):It doesn't, that's correct. It might still be good to know what issue you found though, in case the code is ever reused for something?
Maja Kądziołka (Mar 02 2023 at 16:31):well there was nothing preventing the use of a BumpVec allocated in one arena with a different arena, leading to reads of uninitialized memory and other fun. I'd probably mark arena_with_capacity as unsafe, making the caller ensure that there's exactly one arena of a given type "in context", whatever that would mean for the application
Chris Fallin (Mar 02 2023 at 16:52):ah, right, we always held that invariant in practice; I agree we should have probably marked that with an unsafe
Last updated: Dec 23 2024 at 12:05 UTC