Re:Systems Programming with Zig (Book)
by kobebrookskC3 on Sunday October 05, 2025 @11:38AM
(#45482362)
> there are products that offer memory-safety proofs for C
what does the c checked by this tool look like? for an example like https://play.rust-lang.org/?version=stable&mode=debug&editio... , does the tool accept the assignment with f and reject the assignment with g?
That particular code is shaped by Rust's specific scoping an lifetime rules, but generally - yes (provided you offer annotations for things the tool can't infer). Some changes to the code may be needed to make things easier, but it's still a lot cheaper than a rewrite in a different language.
Re:Systems Programming with Zig (Book)
by kobebrookskC3 on Sunday October 05, 2025 @10:33PM
(#45487114)
in this example, aren't the scoping rules for c pretty much the same?
what do the annotations for the tool look like? is the analysis local, in that it doesn't look into the bodies of other functions? if it is, surely you would have to have lifetimes and be generic over them.
how much c code satisfies the tool? if there's hardly any c satisfying the tool, there might actually be a larger ecosystem of rust code to use.
So the annotations for such tools are pre/post conditions for certain properties (say, pointer validity, ownership). Like types, function annotations can sometimes be inferred, or they may need to be explicit. Once that information is known about a function, there's no need for the tool to look inside it again when analysing callers.
If you want to get a sense of what that may look like, see https://www.frama-c.com (which is a community project, so maybe not as smooth and polished like more professional tools).
Re:Systems Programming with Zig (Book)
by KsassPeuk on Tuesday October 07, 2025 @03:09AM
(#45500201)
Well, Frama-C is maintained thanks to public funding (Europe/France) and industrial users who use it for actual certification of systems. For example, Thales (Common Criteria EAL7), Airbus (DO-178C), EDF (ISO 60880). I don't know what you mean by professional tool if this is not professional ;)
That's not true, though. If memory safety is the only thing that you need and C doesn't have, there are products that offer memory-safety proofs for C (e.g. https://www.trust-in-soft.com). You do need to add some lifetime annotations and may want to change your code here and there, but it's overall much cheaper than a rewrite in a new language. I believe such solutions are more popular, too; few companies - even and especially those that care primarily about correctness - are crazy enough to justify a rewrite of an existing product just for memory safety.
> Paying that cost and not eking out the maximum safety benefit that's practical... Seems a bit dodgy to me.
The cost is not the same, though (and if you only consider rewrites, as I said, there are better options). It sounds like you're saying that any cost is worth any added safety. I don't think that's true, but if it were, then something like ATS is probably what you're after (it isn't, though, because it's practically nobody's choice). Anything short of that is some compromise between cost and safety. Rust's compromise is just different from Zig's. They're both significantly safer than C and a far way off from ATS. Everyone seems to agree that the sweet spot is somewhere on that spectrum - not C, not ATS - but there's no agreement on where.