Writing a C Compiler, in Zig (2025)

fuhsnn•about 5 hours ago

Looking at the repo, the author seemed a little fed up [1] with the nature of lower level language and quitted.

[1] https://github.com/asibahi/paella/blob/main/writeup/c19.md#u...

dwroberts•about 5 hours ago

Feels like maybe something lost in translation with their explanation - they say they were fed up of data structures etc. but they returned to Rust? I’m assuming there’s something a bit more nuanced about what they got tired of with Zig

ecshafer•about 4 hours ago

I think Rust is "higher level" than C or Zig in the sense that there are most abstractions than C or Zig. Its not Javascript, but it is possible to program Rust without worrying too much about low level concerns.

flossly•about 5 hours ago

I thought Zig has a C compiler built in? Or is it just the Zig build system that's able to compile C, but uses an external compiler for that?

Still a proper programmer-flex to build another one.

spiffyk•about 5 hours ago

Zig actually bundles LLVM's Clang, which it uses to compile C with the `zig cc` command. But the long term goal seems to not be so tightly coupled to LLVM, so I'm expecting that to move elsewhere. They still do some clever stuff around compiler-rt, allowing it to be better at cross-compilation than raw Clang, but the bulk of it is mostly just Clang.

There is also another C compiler written in Zig, Aro[1], which seems to be much more complete than TFA. Zig started using that as a library for its TranslateC functionality (for translating C headers into Zig, not whole programs) in 0.16.

[1]: https://github.com/Vexu/arocc

scatbot•about 6 hours ago

Cool project. Feels like writing a C compiler in Zig aligns nicely with the old "maintain it in Zig" idea that was part of Zig's early value proposition. Is that still considered a relevant goal today?

Longer term it also makes me wonder whether something like this could eventually reduce reliance on Clang/LLVM for the C frontend in zig's toolchain.

spiffyk•about 5 hours ago

There is actually another C compiler written in Zig, Aro[1], which Zig started using since 0.16 for its TranslateC module.

[1]: https://github.com/Vexu/arocc

Writing a C Compiler, in Zig (2025)

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