Re: The Case for Rust (in the base system)
- In reply to: Tomoaki AOKI : "Re: The Case for Rust (in the base system)"
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Date: Sun, 21 Jan 2024 07:38:56 UTC
On Sun, 21 Jan 2024 14:10:24 +0900 Tomoaki AOKI <junchoon@dec.sakura.ne.jp> wrote: > On Sat, 20 Jan 2024 21:14:59 -0700 > Alan Somers <asomers@freebsd.org> wrote: > > > On Sat, Jan 20, 2024, 8:44 PM Warner Losh <imp@bsdimp.com> wrote: > > > > > > > > > > > On Sat, Jan 20, 2024, 7:20 PM Alan Somers <asomers@freebsd.org> > > > wrote: > > >> On Sat, Jan 20, 2024 at 7:06 PM Tomoaki AOKI > > >> <junchoon@dec.sakura.ne.jp> wrote: > > >> > > > >> > On Sat, 20 Jan 2024 15:31:23 -0700 > > >> > Warner Losh <imp@bsdimp.com> wrote: > > >> > > > >> > > On Sat, Jan 20, 2024 at 11:45 AM Aleksandr Fedorov < > > >> wigneddoom@yandex.ru> > > >> > > wrote: > > >> > > > > >> > > > What about external dependencies? > > >> > > > > > >> > > > > > >> https://github.com/Axcient/freebsd-nfs-exporter/blob/master/Cargo.toml#L19 > > >> > > >> > > > > > >> https://github.com/asomers/gstat-rs/blob/master/gstat/src/main.rs#L20 > > >> > > >> > > > > > >> > > > Is there any plan for which crates we should take into the > > >> > > > base > > >> system? > > >> > > > > > >> > > > We have had C++ in base for many years, but I don’t see > > >> > > > any good > > >> libraries > > >> > > > for CLI, logging, JSON, etc. > > >> > > > > > >> > > > > > >> > > > > > >> https://doc.rust-lang.org/rustc/platform-support.html#tier-1-with-host-tools > > >> > > >> > > > > > >> > > > Where is the support for Freebsd as a primary platform? > > >> > > > ARM, RISC-V, Power? Should we rewrite devd? > > >> > > > > > >> > > > I think we need to start by providing official > > >> > > > repositories (e.g git.FreeBSD.org/rust.git or > > >> > > > git.FreeBSD.org/go.git) for different languages that > > >> > > > include stable bindings to the system > > >> API: > > >> > > > - sysctl > > >> > > > - libgeom > > >> > > > - libifconfig > > >> > > > - netgraph > > >> > > > - jail > > >> > > > - etc. > > >> > > > > > >> > > > So that it’s not just some anonymous on crates.io that > > >> > > > represents > > >> these > > >> > > > bindings, but our community. > > >> > > > Officially, with support for a stable ABI for releases, > > >> > > > security > > >> patches, > > >> > > > etc. > > >> > > > > > >> > > > After this, it will be possible to think about which > > >> > > > components to > > >> include > > >> > > > in the base system. > > >> > > > > > >> > > > I would be glad to see a more modern language than C in > > >> > > > the > > >> database, but > > >> > > > I’m afraid that it will be like with C++, > > >> > > > that we will get a couple of daemons and utilities and > > >> > > > that’s all. > > >> > > > > >> > > These are all good questions that need good answers, though > > >> necessarily to > > >> > > get started. > > >> > > > > >> > > But the other question that occured to me after my last > > >> > > posting was > > >> "What > > >> > > about build integration?" > > >> > > How much of the rust automation do we take in vs how much do > > >> > > we drive > > >> from > > >> > > a future bsd.rust.mk. > > >> > > I can sketch out bsd.rust.mk (to pick an arbitrary name, > > >> > > we'd likely > > >> need > > >> > > one for what we traditionally > > >> > > think of as libraries (which may or may not map 1:1 onto > > >> > > crates: we > > >> could > > >> > > have c callable libraries > > >> > > written in rust in the future, for example) and one for > > >> > > binaries. Initially, though, if we go with the > > >> > > 'make rust tests possible' then we'd likely need the > > >> > > appropriate > > >> packages > > >> > > installed for whatever > > >> > > dependencies we'd have in the tests. This would give us a > > >> > > taste for > > >> what > > >> > > we'd need to do for > > >> > > base, I'd think. Once we had that notion, I can easily see > > >> > > there > > >> needing to > > >> > > be some sort of > > >> > > rust bindings for ATF/kyua as one of the first libraries / > > >> > > crates that would test that aspect of > > >> > > the build system. That all would be up to the people writing > > >> > > the > > >> tests in > > >> > > rust, I'd imagine. > > >> > > > > >> > > While I could jot out the basics of this integration (so one > > >> > > could > > >> just add > > >> > > the rust > > >> > > tools to a subdir or subdirs, include the bsd.rust.mk or > > >> > > whatever > > >> and then > > >> > > it would build > > >> > > if rust is enabled, and would emit a warning it was skipped > > >> > > because > > >> rust > > >> > > was disabled). > > >> > > We'd find out if this is workable or not and iterate from > > >> > > there. But > > >> that > > >> > > would also require > > >> > > active participation from the rust advocates to make it a > > >> > > reality: I > > >> can > > >> > > put together the > > >> > > build infrastructure for the disabled case, but likely can't > > >> > > on my > > >> own do > > >> > > the rust enabled > > >> > > case. I'd be happy to work with someone to do that, but I'm > > >> > > not going > > >> to be > > >> > > able to do > > >> > > that myself: my need for rust is slight, my knowledge of > > >> > > rust is > > >> weak, etc. > > >> > > Working with > > >> > > someone (or ideally several someones), though it could > > >> > > become > > >> reality. So > > >> > > please contact > > >> > > me if you'd like to work on this. > > >> > > > > >> > > Warner > > >> > > > >> > One way to go could be moving programs rewritten with rust to > > >> > ports. There are some programs (not in rust, though) moved to > > >> > ports, like rcs. > > >> > > >> I've already done this with a few, though I didn't delete the C > > >> versions from base. > > >> usr.bin/gstat => sysutils/gstat-rs > > >> tools/regression/fsx => devel/fsx > > >> > > > > > > So > > > % size `which gstat-rs` `which gstat` > > > text data bss dec hex filename > > > 2094442 176472 568 2271482 0x22a8fa > > > /usr/local/sbin/gstat-rs 19350 1180 41 20571 > > > 0x505b /usr/sbin/gstat % file `which gstat-rs` `which gstat` > > > /usr/local/sbin/gstat-rs: ELF 64-bit LSB pie executable, ARM > > > aarch64, version 1 (FreeBSD), dynamically linked, interpreter > > > /libexec/ld-elf.so.1, FreeBSD-style, stripped > > > /usr/sbin/gstat: ELF 64-bit LSB pie executable, ARM > > > aarch64, version 1 (FreeBSD), dynamically linked, interpreter > > > /libexec/ld-elf.so.1, for FreeBSD 15.0 (1500008), FreeBSD-style, > > > stripped 8:36pm brazos:[3826]> ldd `which gstat-rs` `which gstat` > > > /usr/local/sbin/gstat-rs: > > > libgeom.so.5 => /lib/libgeom.so.5 (0x60fd38647000) > > > libthr.so.3 => /lib/libthr.so.3 (0x60fd38b57000) > > > libgcc_s.so.1 => /lib/libgcc_s.so.1 (0x60fd39af1000) > > > libc.so.7 => /lib/libc.so.7 (0x60fd3be6f000) > > > libbsdxml.so.4 => /lib/libbsdxml.so.4 (0x60fd3a009000) > > > libsbuf.so.6 => /lib/libsbuf.so.6 (0x60fd3a55e000) > > > /usr/sbin/gstat: > > > libdevstat.so.7 => /lib/libdevstat.so.7 (0x448867cd000) > > > libgeom.so.5 => /lib/libgeom.so.5 (0x4488710b000) > > > libedit.so.8 => /lib/libedit.so.8 (0x44887f8d000) > > > libtinfow.so.9 => /lib/libtinfow.so.9 (0x44888aab000) > > > libncursesw.so.9 => /lib/libncursesw.so.9 (0x44889c60000) > > > libc.so.7 => /lib/libc.so.7 (0x4488aaf4000) > > > libkvm.so.7 => /lib/libkvm.so.7 (0x44888f77000) > > > libbsdxml.so.4 => /lib/libbsdxml.so.4 (0x4488ba02000) > > > libsbuf.so.6 => /lib/libsbuf.so.6 (0x4488c68d000) > > > libelf.so.2 => /lib/libelf.so.2 (0x4488ca45000) > > > > > > So that looks scary, like rust is 100x larger binaries... But at > > > runtime it's about the same: > > > USER PID %CPU %MEM VSZ RSS TT STAT STARTED TIME > > > COMMAND imp 14735 0.0 0.0 14140 4828 0 S+ 20:38 > > > 0:00.04 gstat imp 14766 1.3 0.0 15772 6256 0 S+ 20:39 > > > 0:00.02 gstat-rs > > > > > > So the runtime size is at least in the same ballpark (still > > > larger, but not crazy larger). More CPU too, > > > but that's just a polling artifact I think (other times gstat had > > > some, and gstat-rs didn't). > > > > > > Why is the rust binary so much larger? Are the rust runtime and > > > dependencies statically linked? > > > > > > > Yes, that's a large part of it. Rust libraries are usually > > statically linked (though they don't have to be). For example, in > > the output above, notice that gstat-rs does not link to ncurses. > > That's because the equivalent library is statically linked in > > instead. Also, rust programs by default include goodies like stack > > unwinding on panic, which takes extra code too. But that can be > > turned off if you really want to save space. -Alan > > Because of these, I feel rust fits best for commercial DOS apps, not > Unix-based OS'es. In DOS era, AFAIK, most programs installed required > libraries at the same directory which its executable is installed, > regarless exactly same libraries are installed in other directory by > other softwares. This looks very similar as current rust default, > except that libraries are statically linked in rust. > > But rust seems to have (non-default) option to create shared libraries > by --crate-type=dylib and --crate-type=cdylib options [1]. > > Charlie Li pointed me this page before [2]. > > Without this kind of options, linking rust codes with C/C++ codes > would be nonsense. (Whichever should have this kind of options, but > rust ABI seems to be too unstalbe [changing rapidly] to implement it > in C/C++ side.) > > I'd not yet dug in deep enough to conclude or write rust code myself, > so just a thought for now, but I currently think we would better wait > for rust ABI to be stabilized. Until then, rust codes in ports may > increase and maintainers good at rust would increase, too. > It would greatly help to investigate how to introduce rust codes in > base. > > [1] https://doc.rust-lang.org/reference/linkage.html > > [2] > https://lists.freebsd.org/archives/freebsd-ports/2023-September/004546.html > I honestly don't expect many new or current languages to get their own dedicated FFI/ABIs in the future. Especially, if they don't want a full language specific runtime involved. Enforcing a requirement of must export to the C ABI for any libraries going into the base system is very reasonable. On the other side of things restricting the dependency list to packaged stuff is also a good idea. Cargo already includes an option for enforcing the use of a local mirror as its package source.[1] Fedora uses this to guarantee they can build any rust code they package repeatably.[2] [1] https://doc.rust-lang.org/cargo/reference/source-replacement.html [2] https://docs.fedoraproject.org/en-US/packaging-guidelines/Rust/