kani VS nomicon

This is also the backend for Kani - Amazon's formal verification tool for Rust.

https://github.com/model-checking/kani

Nice read! Rust has pushed, and will continue to push, the limits of practical, bare metal, memory safe languages. And it's interesting to think about what's next, maybe eventually there will be some form of practical theorem proving "for the masses". Lean 4 looks great and has potential, but it's still mostly a language for mathematicians. There has been some research on AI constructed proofs, which could be the best of both worlds because then the type checker can verify that the AI generated code/proof is indeed correct. Tools like Kani are also a step forward in program correctness.

Ease setup in Amazon Linux 2 by @adpaco-aws in #2833

Limit --exclude to workspace packages by @tautschnig in #2808

Here's a summary of what's new in version 0.38.0:

> those applications need the proof for correctness so that more dangerous code---say, what would need `unsafe` in Rust---can be safely added

There are actually already tools built for this very purpose in Rust (see Kani [1] for instance).

Formal verification has a serious scaling problem, so forming programs in such a way that there are a few performance-critical areas that use unsafe routines seems like the best route. I feel like Rust leans into this paradigm with `unsafe` blocks.

[1] - https://github.com/model-checking/kani

Enable concrete playback for failure of UB checks by @zhassan-aws in https://github.com/model-checking/kani/pull/2727

Change default solver to CaDiCaL by @celinval in https://github.com/model-checking/kani/pull/2557 By default, Kani will now run CBMC with CaDiCaL, since this solver has outperformed Minisat in most of our benchmarks. User's should still be able to select Minisat (or a different solver) either by using #[solver] harness attribute, or by passing --solver= command line option.

Add support for sysconf by feliperodri in #2557

it’s even written by the same person that wrote the Nomicon (the guide to the dark arts of unsafe)

If you want to dive deeper you can always have other options but now there are concrete cases, if you want to do low level thing https://doc.rust-lang.org/nomicon/ while if you want multi thread/concurrency stuff https://marabos.nl/atomics/ . There are many many books so you will have to point yourself to what you want

Nonononono. SeqCst is the most error prone memory order: https://github.com/rust-lang/nomicon/issues/166

Hope this helps. For more details, see the Rustonomicon. I referenced the subtyping chapter here extensively.

Nice video! Glad I could help out. This stuff is hard, and I'm still learning a lot about it myself even years later. The Rustonomicon is a great read if you haven't already.

Have you got a moment to read through the good book , after reading through this perhaps try the Rustonomicon.

That is not what UB means. Undefined Behaviour is behaviour that the compiler is allowed to assume will never happen, and which can consequently cause miscompilations due to optimisation passes gone wrong if it does in fact occur in the source code.

It's true that Rust does not have a written specification that clearly delineates what is and isn't UB in a single place. But:

1. UB is impossible in safe code (modulo bugs in unsafe code)

2. There are resources such as the Rustinomicon (https://doc.rust-lang.org/nomicon/) that provide a detailed guide on what is and isn't allowed in unsafe code.

In practice, it's much easier to avoid UB in Rust than it is in C++.

However, this is a wide topic out of scope for a Reddit comment, so maybe just read the Rustonomicon. It explains everything about data handling in Rust.

The ownership model & borrow checker makes rust a bit of an awkward language in which to write complex data structures like trees and graphs. It can be done - since you can always use raw pointers & unsafe code when you absolutely need to to treat rust like C. But the language fights you, and the community can get a bit moralistic about this sort of thing. The rust nomicon is a fantastic resource for learning the limits of the borrow checker, and where and how to use unsafe code correctly. You will need unsafe less than you think you will, but sometimes you will have no choice.