Comment by dnautics
8 hours ago
no. let me be clearer; it is possible to intercept zigs ir from the compiler NOW (well, 15.2 proven) and have a third party package do borrow checking from the data that flow through, without changing zig (think "how miri works without changing rust"). this is not currently directly possible without changing the compiler (~ 50 loc), however the core team has indicated that exporting ir, the only change needed, will be a supported feature once the language stabilizes.
How do you get the information to check properly without lifetimes in the signature?
lifetimes are not the only way to check safety. you just need to detect conflicts in the data dependency graph, lifetimes are in some way an overspecification (for safety, there are autoaliasing advantages). i suspect agnostic conflict detection is probably more expensive, too, but 1) borrow checking was not the slow step in rust compilation and 2) maybe you dont have to check for memory safety on every compile. on commit or on ci is probably fine
Gotcha! Well this sounds like a cool project, I look forward to seeing how it turns out.
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I’m incredibly excited for this and have been looking forward to it for a while - I think new moves in IR will solve many issues with have with dynamic analysis of memory safety. The decompilation into other representations like Binary Ninjas IR have been a godsend to actually seeing what the hell Rust and Objective C do on the backend and understand actual cost the compiler makes to create memory fences.