Re: LLVM-libc FreeBSD Port

Schrodinger ZHU Yifan <[email protected]> Mon, 11 May 2026 02:16:22 +0000

Newsgroups	gmane.os.freebsd.devel.hackers
Message-ID	<OHangJFWasw6SxcKEPMX4jcEzrJj4h_mm9y9DymONZ2qt2QnYT7BSG6SY84cnEQOTcldl6oAdtn40Ingw7sYXb9cGviO31tc4K9G1RLA11w=@zhuyi.fan>

The existing PR was really just a PoC. 

As for syscall stubs, it depends on the recommended method from the Oses. I can
try to come up with a libsys version if that is the suggested way to do it.

On Linux, we also have a separated syscall_wrapper module; but that is more like
a header library.

Yifan



Schrodinger ZHU Yifan, Ph.D. Student
Computer Science Department, University of Rochester

Personal Email: [email protected]
Work Email: [email protected]
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-------- Original Message --------
On Sunday, 05/10/26 at 21:35 Minsoo Choo <[email protected]> wrote:

> On Sunday, May 10th, 2026 at 3:37 PM, Schrodinger ZHU Yifan <[email protected]>
> wrote:
> 
> > Hi all,
> > 
> > I am one of the maintainers of LLVM libc, mainly responsible for its
> > threading support, and I currently daily drive FreeBSD.
> > 
> > LLVM libc is a from-scratch implementation of the C standard library
> > developed as part of the LLVM project. It is designed to be modular, so
> > individual components can be used independently; multiplatform, targeting
> > Linux, GPUs, bare-metal embedded systems, UEFI, macOS, Windows, and more;
> > and written in modern C++ with a focus on correctness, performance, and
> > safety. See also https://libc.llvm.org/ .
> > 
> > We recently had a casual discussion on our Discord about bringing up FreeBSD
> > support. This would be an interesting step toward broadening LLVM libc’s
> > perspective from Linux-only to more general *nix portability, which should
> > also help improve its overall structure. The initial bring-up was fairly
> > straightforward (the PR is a bit outdated but can be fixed without much
> > effort): https://github.com/llvm/llvm-project/pull/124459. This already
> > delivers LLVM libc’s correctly rounded math and mathvec support to FreeBSD.
> > 
> > However, moving toward completeness will require more work. We would also
> > need CI pipelines and stable maintainers before FreeBSD could be added to
> > the list of supported platforms.
> > 
> > Personally, I think bringing a modular libc design with modern features that
> > continue to evolve rapidly would also be a plus for the FreeBSD community,
> > especially given FreeBSD’s close relationship with LLVM. If anyone is
> > interested, please feel free to ping me at i [at] zhuyi [dot] fan.
> > 
> > By the way, the Discord link on your website appears to be broken.
> > 
> > Best,
> > Yifan
> > 
> > 
> > Schrodinger ZHU Yifan, Ph.D. Student
> > Computer Science Department, University of Rochester
> > 
> > Personal Email: [email protected]
> > Work Email: [email protected]
> > Github: SchrodingerZhu
> 
> Hi Schrodinger,
> 
> Glad to hear that you are working on this project. I'm working on LLDB for
> FreeBSD, so feel free to reach me out if you have any questions on FreeBSD.
> 
> So I want to clarify here: LLVM's libc has its own header and implementation,
> so it is possible to compile FreeBSD libc on other OSes, right? This also
> means llvm's libc doesn't use our libsys library but has its own syscall
> assemblies, which I see from your GitHub PR.
> 
> --
> Minsoo Choo

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