Re: The Case for Rust (in the base system)

I don’t want to do a what-aboutism, but if all we’re looking for is a good and 
secure system programming language, the alternatives are nicer.

There’s Modula-3, which, unlike Rust, supported FreeBSD as Tier 1, I’m sure the 
compiler is smaller, although hasn’t been updated in a while.

On that thought, Wirth’s passing reminded me of Oberon-2, which does have a 
port on FreeBSD, lang/voc. It can also “attach” to the C functions. Last year I 
integrated libxo, libucl and libjail with Oberon-2/VOC and it all worked fine.
The compile times are also impressive.[1][2]

However, if all we’re looking for is to be fancy and follow the industry, Rust 
doesn’t seem bad overall. The main issue is the toolchain. 2x compile time 
would be awful. Optional targets would be nice, but then people will start 
writing X/Y/Z in Rust, and before you know jail(8) would start requiring a 
large external compiler.

Again, to be clear, I would like to hear the “why” more than the “how”.

1: https://github.com/antranigv/voclibucl
2: https://github.com/antranigv/voclibxo 

Cheers,

—
Antranig Vartanian
https://antranigv.am/
PGP Key ID: 0x2D59F21C

> On 20 Jan 2024, at 8:51 PM, Alan Somers <asomers@freebsd.org> wrote:
> 
> In a recent thread on src-committers, we discussed the costs and
> benefits of including Rust code in the FreeBSD base system.  To
> summarize, the cost is that it would double our build times.  imp
> suggested adding an additional step after buildworld for stuff that
> requires an external toolchain.  That would ease the build time pain.
> The benefit is that some tools would become easier to write, or even
> become possible.  Here is a list of actual and potential Rust projects
> that could benefit from being in-tree.  If anybody else has items to
> add, I suggest moving this into the project wiki:
> 
> Stuff that could only be written in Rust if it were in base
> ===========================================================
> 
> * ctl-exporter (I started this, but discovered that the CTL stats API is
>  unstable, so it can't live in ports.  Instead, I had to do it in C).
>  https://github.com/freebsd/freebsd-src/commit/1a7f22d9c211f504f6c48a86401469181a67ec34
> 
> * fusefs tests.  Absolutely impossible to do in C.  I considered Rust, but went
>  with C++ so they could live in base.  They are too closely coupled to
>  fusefs(5) to live out-of-tree.
>  https://github.com/freebsd/freebsd-src/tree/main/tests/sys/fs/fusefs
> 
> * devd.  Currently C++, but imp suggested a rewrite.
>  https://github.com/freebsd/freebsd-src/tree/main/sbin/devd
> 
> * zfsd.  Currently C++, but I've long pondered a rewrite.  Using Rust would
>  make it more testable.
>  https://github.com/freebsd/freebsd-src/tree/main/cddl/usr.sbin/zfsd
> 
> * nscd.  Currently C, but confusing and with no test coverage.  I've
>  contemplated a rewrite myself, but I don't want to do it in C.
>  https://github.com/freebsd/freebsd-src/tree/main/usr.sbin/nscd
> 
> * The userland portion of the 802.11ac and Lightning stacks.  scottl suggested
>  that these were good candidates for Rust.
> 
> * freebsd-kpi-r14-0 .  https://crates.io/crates/freebsd-kpi-r14-0
> 
> Stuff that can live in ports, but would be nicer in base
> ========================================================
> 
> * gstat-rs https://crates.io/crates/gstat
> 
> * geom-exporter (I've started this, but haven't published it)
> 
> * nfs-exporter https://crates.io/crates/freebsd-nfs-exporter
> 
> * virtiofsd-rs .  Nobody has yet tried to port it to FreeBSD.  But if the
>  connection to bhyve(8) is too intimate, it might be hard to do in ports.
>  https://gitlab.com/virtio-fs/virtiofsd
> 
> * jail-exporter https://crates.io/crates/jail_exporter
> 
> * Various jail managers have been attempted in Rust.  I think these are fine in
>  ports, but others like Goran Mekic have opined that they should be moved to
>  base instead.
> 
> * musikid's pjdfstest rewrite.  I think it would be great to start using this
>  to test the base system's file systems.  If the tests themselves lived in
>  base, they would be easier to sync with file system development.
>  https://github.com/musikid/pjdfstest
> 
> * pf-rs.  I suspect that the API isn't very stable.
>  https://crates.io/crates/pf-rs
> 
> * benchpmc.  The pmc counter names changes between releases.
>  https://crates.io/crates/benchpmc
> 
> FreeBSD-related applications that are just fine in ports
> =========================================================
> 
> * fsx-rs.  Unlike pjdfstest, this only tests datapath APIs.  Those are usually
>  more stable than control path APIs, so I think there's little to be gained by
>  moving this into base. https://crates.io/crates/fsx
> 
> * ztop.  It uses ZFS's kstats sysctl interface, which is pretty stable.
>  https://crates.io/crates/ztop
> 
> * iocage-provision  https://crates.io/crates/iocage-provision
> 
> * rsblk https://crates.io/crates/rsblk
> 
> * xfuse  https://github.com/KhaledEmaraDev/xfuse
> 
> Other FreeBSD-related libraries in Rust
> =======================================
> Just see the list at https://crates.io/keywords/freebsd
>