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- Hacker News
- I suspect that there is a body of C programmers out here that use C on a regular basis that aren’t posting who know that using C safely is 99% just using Valgrind and some specific GCC or llvm flags and you’re done.
They don’t reply to these threads to share that knowledge because these threads devolve into cesspools about how you should just use Rust despite the language not meeting specific requirements authors have that you have to do additional work and maintenance for in “safe” languages that you get for free in C because you don’t have to emulate it.
by bellowsgulch - > I suspect that there is a body of C programmers out here that use C on a regular basis that aren’t posting who know that using C safely is 99% just using Valgrind and some specific GCC or llvm flags and you’re done.
Absolutely right! I sincerely hope they share their knowledge here and elsewhere.
> They don’t reply to these threads to share that knowledge because these threads devolve into cesspools
HN is often rage-inducing when it comes to comments on C/C++/Fortran/Cobol/etc. older languages and systems. There are many critical and industrial-strength systems developed by the previous generation of engineers/programmers which today's noobs/cargo-cultists cannot even hope to imagine much less understand.
As an example, people talk about all the great features provided by Erlang but forget that its BEAM VM where most of the "magic" resides is actually written in C! Imagine how much expertise lies buried in its implementation!
by rramadass
I wish that were the case, but it's not. Dynamic analyzers are fantastic and everyone should be using them constantly, but they don't solve the problem of UB. They tell you whether your code, as translated by a specific compiler using a specific set of flags today has detectable problems. There are still gaps, and what's true today might not be true even for the same source code built tomorrow, or given different inputs. Asserting my safety-critical code does X or Y is important to me, and neither C nor C++ have standard tooling that fully addresses that need.using C safely is 99% just using Valgrind and some specific GCC or llvm flags and you’re doneOther languages are much farther along than this. You can in theory take a pile of Rust and isolate exactly the points where undefined behavior might occur, or eliminate them entirely in Ada/Spark.
- > I suspect that there is a body of C programmers out here that use C on a regular basis that aren’t posting who know that using C safely is 99% just using Valgrind and some specific GCC or llvm flags and you’re done.
C* (the submitted language) is not just about determining memory correctness and related program features like what Valgrind will do for you (or help with). It's about proving correctness of programs more generally, so any C programmer not looking at it because they know about Valgrind are choosing to skip something interesting for a very poor reason.
by Jtsummers - This is a competitor of ATS3.by fithisux
- Interesting, didn't know of this. Some resources;
The ATS Programming Language - https://www.cs.bu.edu/~hwxi/atslangweb/
ATS3-Xanadu - https://github.com/githwxi/ATS-Xanadu
From https://en.wikipedia.org/wiki/ATS_(programming_language)
As of 2024, ATS/Xanadu (ATS3) is being developed actively in ATS2, with the hope of reducing the learning needed by two main improvements:
- Adding an extra layer to ATS2 to support ML-like algebraic type-checking
- Type-based metaprogramming using algebraic types only
With these improvements, Xi hopes for ATS to become much more accessible and easier to learn. The main goal of ATS3 is to transform ATS from a language mainly used for research, into one strong enough for large-scale industrial software development.
by rramadass - I think formal verification is a super interesting field, but this is a non-starter for me because I do not have a backwards E on my keyboardby slowcache
- There already is a C* : https://en.wikipedia.org/wiki/C*by jensgk
- Does it matter? Is the global namespace permanently depleted because of an obscure language that nobody has used in 30 years?
- That C* uses .cs, but nobody is complaining about C# using that extension
That C* was released in 1993
Who actually cares about the name collision?
by dymk - Found another one:
https://www.cs.columbia.edu/~sedwards/classes/2021/4115-fall...
https://github.com/kkysen/cstar
And to sibling comments: I care. Non-mainstream languages are talking points. I don't want to get 15 minutes into a "you should have effects like Koka" argument and then find out the other person is talking about a different Koka.
by mrkeen - I like the concept of separation logic as much as the next guy, but I don't think this is it. Just look at the examples, with loop invariants alone being longer than the whole example. It's not only a problem with ergonomics, but it leaves a lot of space for specification bugs.
And I suspect that cross section of people writing C code you want to verify with formal verification folks is not particularly big.
by IsTom - > And I suspect that cross section of people writing C code you want to verify with formal verification folks is not particularly big.
Perhaps not, but C is still used in a lot of critical systems. Things like this for proving properties of some core of your program can be very helpful.
by Jtsummers - Names for C successor languages are pretty well exhausted by this point, so I sympathize, but I strongly associate the name C* with a decade-old rant about C compilers’ aggressive exploitation of undefined behavior: https://www.complang.tuwien.ac.at/kps2015/proceedings/KPS_20... . (In calling it a rant I don’t mean that it’s altogether unpersuasive. Its style is just a bit spicier than I am used to seeing typeset in Computer Modern.)by gdwatson
- > We claim that C achieves real-time program verification, i.e., the user can carry out verification as they program the implementation code incrementally. It achieves this goal by orchestrating the symbolic-execution engine and the LCF-style proof kernel together, creating a proof-supporting runtime that runs proof-code blocks and symbolic execution of program segments in an interleaving manner
That's why such thing is mostly useless. C is used in places where performance is important and nobody want to sacrifice performance for such proofing. Even more, if such proofing is too slow, it's better to use something like Fil-C.
by Panzerschrek - The authors cite this, but just to mention it: this sounds like F*, another proof-oriented language. (https://fstar-lang.org/)
F* is in the ML family of languages, so it looks pretty different from C*.
by Taikonerd - I really think that verification aware languages are going to become a necessity
Wrote a bit about this recently
https://gavinray97.github.io/blog/design-by-contract-and-eff...
by gavinray - I've been looking at model checkers and program proof assistants on and off since FDR and Isabelle/HOL and the like, and there were similar tools going back another decade before that. If you're verifying part of an ASIC or a crypto protocol or something similar they're fine (if extraordinarily painful to use), but for anything else they've been bypassed by AI. I'm not saying that as an AI fan but because by the time you get your PhD and then spend another five years learning how to use the tool and mark up the code and hope you got the markup right and after another six months of what feels like trying to make a string go in a certain direction by pushing it and the tool finally finds a nonexploitable buffer overflow in a function that's never called you realise you could have done the same thing with $2 in AI tokens. It's the program verification technology of the future, and always will be, while "claude, find places where this code does things it shouldn't" is right now and doesn't require a PhD to use.
- The problem I've been having is the LLM's are super dodgy, not even ten minutes ago the 'solution' to a proof failing was to disable that check in the static analysis harness so the tests pass since their first try (with a counter example and lemma from the literature in hand) didn't fix the issue.
Maybe it's an issue because it controls both sides of the fence and can change things willy-nilly when it thinks I'm just watching the youtubes but I haven't been able to find a another way to do this so, here we are...
by UncleEntity - I totally agree. I have this nagging feeling that LLMs push things like this past the breaking point. Effects and contracts are _obviously_ useful to humans as well, we've just gotten by without them for a long time. But when you have intelligence on demand, context building is a huge bottleneck, and local reasoning becomes way more useful from an efficiency perspective.
I'd love to see some actual experiments with LLMs in this area. There are a fair number of languages with effect implementations at this point.
by amw-zero - The first thing people need to study is the "Correct by Construction" approach to programming as espoused by Edsger Dijkstra. Only then will the mathematical concepts used in verification aware languages start making sense and one can better understand what and how to use it.
One of the best books to learn this from is The Correctness-by-Construction Approach to Programming by Derrick Kourie and Bruce Watson - https://link.springer.com/book/10.1007/978-3-642-27919-5
The book actually uses Dijkstra's GCL language and wp-calculus along with Carroll Morgan's Refinement Calculus to demonstrate step-wise derivation of programs from specifications using a lot of examples.
by rramadass - The "C*" language website - https://cstarlang.org/en/intro.html
See in particular, usage benefits with LLMs (last para of https://cstarlang.org/en/intro.html) and how to use it with LLMs (https://cstarlang.org/en/tutorial/cstar-mcp.html).
Note that the paper/language are from 2025 and so pretty recent.
by rramadass - I've been on this horse for a while now. I've settled on learning Ada/SPARK. Ada 2022 will start feeding a new SPARK 2014 update. Yes, they are both verbose, if you don't like that sort of thing, and don't like Pascal-like syntax. Believe me, I like APL/J/k/uiua/BQN and Forth and ASM. I am usually syntax agnostic as long as the PL and the ecosystem (more important than most think), meet your needs. I tried Rust back in 2018, and then again in 2023, but found it very complex and Ok, not a fan of the syntax. I would have preferred more ML or Haskell-like syntax. Zig seemed nice, but different use case, and too new. After all, Ada/SPARK have been on huge, high-assurance, high-safety applications for decades. Rust is getting some of their love, and vice versa. AdaCore had created a verified Rust compiler, but with a real world product (Blacktail hoist) in the works, we need a toolset and guarantees and ease of auditing and acceptance to achieve high safety and standards certifications. Think aerospace, defense, railway, and automotive. I started programming in 1977, so there's always a place in my heart for ASM/C. I played with F#, F*, and LOW from MS, and they are good, but they and Rust simply don't have the real world legacy of Ada/SPARK. I have been using Shen to write some formally verified models of less safety-critical areas of our software and I find it refreshing, however, my day job is to stay focused on Ada/SPARK until Rust matures more with a formally verifed proven toolset. There are certainly efforts and crates available in that direction, so hopefully others will bring it to where it needs to be. Lean is another one I have been playing with for some of the more overall logic proof of the system we are building.by eggy
- I think in 2026 complaining about verbosity is a moot point, when folks are programming writing book sized Markdown files for AI tools.
Heck, even complaining about COBOL programming feels like a joke now.
Kudos on you Ada adventures.
by pjmlp