kani VS gdbstub

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

now integrate gdbstub to support debugging code inside the emulator :)

Shameless plug, but have you considered integrating gdbstub rather than rolling your own debugger? I know a couple folks out there have successfully integrated it into their PS1 emulators with great success.

I've worked really hard to keep gdbstub panic free in its minimal configuration, going so far as to write some informal scripts that parse rustc's asm output to scan for the presence of panicking code paths.

crates.io | docs | repo

As a totally shameless plug, I'm the maintainer of gdbstub, a bare-metal, no_std, no_alloc, and size-optimized implementation of the GDB Remote Serial Protocol. One of the major changes slated for the upcoming release 0.6 is support for a new state-machine based API, which makes it possible to drive gdbstub directly via bare metal interrupt handlers (i.e: send/recv data over UART, handling breakpoints via the undefined instruction trap interrupt, etc...).

Continue working on a new API in gdbstub that'll make it easier to use directly from an interrupt handler when debugging code in a no_std, bare-metal OS environment.

I ran into almost this exact same problem while working on gdbstub, whereby I an API that allowed users to mix/match protocol features however they wanted, while also preventing users from accidentally implementing mutually-exclusive features. Moreover, I wanted to have a "zero cost" way to enable/disable API features without relying on cargo features. The solution I came up with is something I've been calling "Inlineable Dyn Extension Traits", or IDETs.

For a concrete example of how smart the Rust compiler is, I have a small writeup + test-repo that benchmarks a technique I came up with while working on gdbstub that [ab]uses the compiler's devirtualization and inlining optimizations to create runtime feature flags that are entirely compiled out if hard-coded to false at runtime.