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

> On Jan 19, 2024, at 10:15, John Baldwin <jhb@freebsd.org> 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.

Based on my recent adventures with this, I concur. Our version of LLVM in base is not compatible with the copy rust needs, so rust would always need to be bootstrapped with world.

It would need to be a full toolchain as well to build all of the rust targets. Using llvm built for a single target would only function as the initial bootstrap toolchain.

Finally, the bootstrap compiler (via rustup) has tight requirements around versioning and is precompiled for the host. It turns into a nightmare if new syscall support is added or if compat support is required to run the binary…

We’d be better off importing golang instead of rust.

HTH,
-Enji