Re: git: 8bae22bbbe65 - main - fusefs: prefer new/delete over malloc/free

On Fri, Jan 19, 2024 at 10:15:06AM -0800, John Baldwin wrote:
> On 1/19/24 7:38 AM, Alan Somers wrote:
> > On Fri, Jan 19, 2024 at 6:56???AM Alan Somers <asomers@freebsd.org> wrote:
> > > 
> > > On Thu, Jan 18, 2024 at 10:32???PM Enji Cooper <yaneurabeya@gmail.com> wrote:
> > > > 
> > > > 
> > > > > On Jan 17, 2024, at 2:50???PM, Alan Somers <asomers@FreeBSD.org> wrote:
> > > > > 
> > > > > The branch main has been updated by asomers:
> > > > > 
> > > > > URL: https://cgit.FreeBSD.org/src/commit/?id=8bae22bbbe6571da9259e0d43ffa8a56f4b3e171
> > > > > 
> > > > > commit 8bae22bbbe6571da9259e0d43ffa8a56f4b3e171
> > > > > Author:     Alan Somers <asomers@FreeBSD.org>
> > > > > AuthorDate: 2024-01-15 23:49:47 +0000
> > > > > Commit:     Alan Somers <asomers@FreeBSD.org>
> > > > > CommitDate: 2024-01-17 22:49:41 +0000
> > > > > 
> > > > >     fusefs: prefer new/delete over malloc/free
> > > > > 
> > > > >     MFC after:      2 weeks
> > > > >     Reviewed by:    kib
> > > > >     Differential Revision: https://reviews.freebsd.org/D43464
> > > > 
> > > > Why not use smart pointers instead?
> > > > -Enji
> > > 
> > > Only because this stuff all evolved from C code.  Smart pointers would
> > > certainly work.
> > 
> > Actually, TBH it's because I'm not real great with C++.  It's a
> > difficult language, and after 2016 I stopped even trying to improve my
> > C++ skills.  Instead, I've been focusing on Rust.  Even when I wrote
> > these tests in 2019, I strongly considered using Rust instead of C++.
> > In the end, the only thing that forced me to use C++ is because I
> > wanted them to live in the base system, rather than in ports.
> > 
> > I still dream about the day when Rust is allowed in the base system.
> > If it were, then in addition to these tests, I would've converted
> > gstat to Rust (rather than add sysutils/gstat-rs to ports), added the
> > nfs-exporter (instead of putting it in net-mgmt/nfs-exporter), added a
> > ctl-exporter (which is impossible to do in ports, so I had to do that
> > one in C), and converted tools/regression/fsx in place (instead of
> > putting in devel/fsx-rs).  Maybe a couple of other things, too.  Like
> > ztop, or the geom-exporter that I have half-written.  I've also been
> > tempted to rewrite zfsd in Rust.
> > 
> > Alas, I sense that there is little appetite for bringing Rust into contrib.
> 
> Brooks' opinion is that to support Rust in base we probably need to require
> always using an external toolchain as otherwise we would need to keep two
> copies of LLVM in base.

I think the most sensible route is to start bringing in Rust code that
requires an external toolchain.  The first step would probably be to
figure out how to build a helloworld with a RUST_TOOLCHAIN variable set
and no network access.

There are a bunch of bootstrapping and reproducibility issues to
consider, but I think the fixes mostly lie outside the src tree.

-- Brooks