prusti-dev VS rustig

> The overall goal would be to figure out classical error conditions like nill pointers deference.

> If I can figure out if a pointer will be nil in some execution branch, there is no reason why a computer cannot do the same.

Note, this is called flow-sensitive typing (also called type narrowing) and I think that typescript does it.

https://en.wikipedia.org/wiki/Flow-sensitive_typing

> I personally would see this as an human race level upgrades. Imagine feeding your code to a CI that spit back something like: "you will have a panic at line 156 when your input is > 4"

A model checker can do that!

See this

https://model-checking.github.io/kani/tutorial-kinds-of-fail...

Other techniques are also possible

https://github.com/viperproject/prusti-dev#quick-example

(Here I could link a lot of things, I just selected two Rust projects to illustrate)

This works better if you are able to provide contracts in your API that says which guarantees you provide. Alternatively, asserts are useful too.

You might be interested in the Prusti project, which statically checks for absence of reachable panics, overflows etc. It also allows user-defined specifications such as pre and post-conditions, loop body invariants, termination checking and so on.

https://github.com/viperproject/prusti-dev

This is called refinement types and prusti might be the project you saw.

But there's also a lot of exciting work around formal verification like Prusti.

prusti

Efforts: seL4, Project Everest, the Prossimo project of the ISRG, Let's Encrypt, and Prusti for the Rust language

Wow that sounds really cool! I'm not an expert but does that mean that one day you could implement dependend types or refinement types in Rust as a crate ? I currently only know of tools like: Flux Creusot Kani Prusti

There is also rustig though it seems quite dead.

There’s the rustig tool (https://github.com/Technolution/rustig) that looks for code paths leading to the panic handler. Not sure if it still works though.

That's fair. I think I may just be a bit sore that Rustig was allowed to bit-rot and findpanics hasn't seen a commit since 2020.

There's Rustig which does it for panics, though it seems unmaintained and uses inspection of the final binary rather than source code/AST inspection.

You might be interested in this: https://github.com/Technolution/rustig

> Doesnt Rust have implicit panics on indexing out of bounds?

It does yes. A fair number of other constructs can panic as well.

> I wonder if any codebases lint those away.

Clippy has a lint for indexing so probably.

For the general case, it's almost impossible unless you're working on very low-level software (embedded, probably kernel-rust eventually) e.g. `std` assumes allocations can't fail, so any allocation will show up as a panic path.

https://github.com/Technolution/rustig can actually uncover panic paths, but because of the above the results are quite noisy, and while it's possible to uncover bugs thanks to rustig it requires pretty ridiculous amounts of filtering.

This comment is strongly confused.

> [1] https://github.com/Technolution/rustig

That's a binary analysis tool. It is only approximate, and does not claim to be an accurate analysis like unsafe-checking and typechecking are:

https://github.com/Technolution/rustig#limitations

> All paths leading to panic! from one of those functions (whether actually used or not) will be reported.

It also only works on x86_64 binaries.

Panics are an ugly leftover from the bad old days before Rust had nice monad-like syntax for Result error-handling (the "?" syntax). It's time for panic to sunset.