This project is no longer under active development, it was last successfully built and tested with zig version 0.12.0-dev.1468+e9a6197a8 The zig project is taking an alternate approach to archiving that is more tightly integrated with the linker in order to support incremental compilation of zig source when generating static libraries.
This repo contains an in-progress attempt to write an archiver in zig in order to solve this issue.
So the project did/has reached a state where it works as a drop-in replacement for llvm ar when used as an archiver when building redis on MacOS/Linux. Sometimes zig updates cause regressions which need to fixed.
CI has been setup for this.
The next steps are to expand the testing suite (leveraging the testing harness that zld uses) to confirm zig ar can work as an llvm ar replacement under a wider set of circumstances (culminating in being used with the self-hosted compiler).
The current basic test-suite just compares the output of zig ar with llvm ar and validates the the results are byte-for-byte identical, however this isn't really ideal and probably stricter than what is needed.
If you would like to contribute please do let me know! Progress on this project has be non-linear and I have busy periods, but if you ping an issue or DM me on Discord (I'm on the zig server, I will always aim to be responsive.
The thing that make this tricky is that the "ar" format used as a basis for the archives that linkers use hasn't been standardised, meaning that depending hon the platform being targeted - the format can vary in subtly different ways.
Three main variants to focus on (for now):
- BSD (32 & 64 Bit) (the latter used on Darwin)
- System V (or GNU) (32 & 64 BIT)
- Windows
The goal is to make something that is a drop-in replacement for llvm-ar
The documentation for llvm-ar can be found here:
The Wikipedia article on the format here:
https://en.wikipedia.org/wiki/Ar_(Unix)
A lot of the important operations supported by llvm-ar aren't actually documented in the program itself. However, as it is compatible with other ar implementations a reference man page for one of those can be found here: