Fil-C for programmers

Posted Oct 28, 2025 17:54 UTC (Tue) by tialaramex (subscriber, #21167)
Parent article: Fil-C: A memory-safe C implementation

I'm interested in adoption of Fil-C by C and C++ programmers because for some years my assumption has been that most remaining C programmers in particular want DWIM and so they won't be any happier in Fil-C than in say (safe) Rust since these languages both lack the unconstrained Undefined Behaviour where DWIM thrives, if you write nonsense in Fil-C your program doesn't work and it's your fault which presumably was not what you meant. So widespread enthusiasm for Fil-C from C programmers would indicate that I was completely wrong, which would be a pleasant surprise.

For users in a bunch of cases this is a no brainer, Daroc gave their shell as an example but I'm sure most of us run many programs every day where raw perf just isn't a big deal. I am interested in programmers rather than users because I think that influences whether Fil-C is just an interesting project for our moment or it becomes a "successor" to C in a way that Zig, Odin etc. never could.

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Fil-C for programmers

Posted Oct 28, 2025 18:15 UTC (Tue) by rahulsundaram (subscriber, #21946) [Link] (1 responses)

> I am interested in programmers rather than users because I think that influences whether Fil-C is just an interesting project for our moment or it becomes a "successor" to C in a way that Zig, Odin etc. never could.

My expectation is that there isn't going to be a single successor to C. For some group of people, that was C++ a long time back. For others it is going to Rust or Zig or something else. For the final group they are going to keep coding in C forever and it will more of a generational change eventually.

Fil-C for programmers

Posted Oct 28, 2025 18:32 UTC (Tue) by daroc (editor, #160859) [Link]

I think the point of Fil-C, as a C implementation, is precisely to support the people and projects that are just going to keep using C — in a way that still lets users avoid memory safety issues if they so choose.

Fil-C for programmers

Posted Oct 28, 2025 18:34 UTC (Tue) by rweikusat2 (subscriber, #117920) [Link] (4 responses)

If this is just another C implementation, it's distribution packagers who would need to adopt it and possibly other people who routinely compile but not necessarily write code.

Fil-C for programmers

Posted Oct 29, 2025 1:35 UTC (Wed) by rahulsundaram (subscriber, #21946) [Link] (3 responses)

Fair point. Reducing friction to adoption could work if the performance impact is universally close enough.

Fil-C for programmers

Posted Oct 29, 2025 11:45 UTC (Wed) by k3ninho (subscriber, #50375) [Link] (1 responses)

Adding a runtime to Debian, say like how kFreeBSD was added, would be an interesting avenue for running some things inside a memory-safe environment while finding and fixing memory-type UB for packages people want to run in Val-C.

K3n.

Fil-C for programmers

Posted Oct 30, 2025 22:23 UTC (Thu) by k3ninho (subscriber, #50375) [Link]

Via the discussion of this lwn.net piece at lobste.rs [1], it turns out [2] that djb had already got in with this.

1: https://lobste.rs/s/mg0aur/fil_c_memory_safe_c_implementa...
2: https://cr.yp.to/2025/fil-c.html

K3n.

Fil-C for programmers

Posted Oct 29, 2025 12:18 UTC (Wed) by Baughn (subscriber, #124425) [Link]

It also might eliminate the reasoning some programmers use, that they “have to stick to C because it’s the fastest option”.

Well, now it’s not the fastest option. And no, you don’t get to tell me not to compile everything with FilC. We just need to make that the standard.