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diff --git a/community/gsoc/project_ideas/rust.mdwn b/community/gsoc/project_ideas/rust.mdwn new file mode 100644 index 00000000..f6be8132 --- /dev/null +++ b/community/gsoc/project_ideas/rust.mdwn @@ -0,0 +1,214 @@ +[[!meta copyright="Copyright © 2023 Free Software Foundation, Inc."]] + +[[!meta license="""[[!toggle id="license" text="GFDL 1.2+"]][[!toggleable +id="license" text="Permission is granted to copy, distribute and/or modify this +document under the terms of the GNU Free Documentation License, Version 1.2 or +any later version published by the Free Software Foundation; with no Invariant +Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license +is included in the section entitled [[GNU Free Documentation +License|/fdl]]."]]"""]] + +[[!meta title="Porting Rust"]] + +[[!template id=highlight text="""/!\ Obsolete /!\ + +--- + +Vedant Tewari has been working on this as a Google Summer of Code 2023 project."""]] + +The goal of this project is to make the [Rust +language](https://www.rust-lang.org/) available on GNU/Hurd. + +Presumably less work will be needed on the language's frontend itself, but +rather on the supporting libraries. + + +The Rust language is being used more and more widely, and notably in +rather fundamental libraries such as librsvg or python-cryptography. It +is thus more and more pressing for GNU/Hurd to have a compiler for Rust. + +The Rust compiler itself is quite portable, but its runtime library, libstd, +needs to be ported to the GNU/Hurd system. This essentially consists in telling +Rust how the standard C library functions can be called, i.e. the C ABI. + +There as an [initial attempt against rustc 1.30](https://people.debian.org/~sthibault/hurd-i386/rustc-1.30-patch) that was enough to get rustc +to crossbuild, but it was missing most of what libstd needs. It is most probably +very outdated nowadays, but that gives an idea. + +An example of the main part of the libstd port can be seen for the [VxWorks +port](https://github.com/rust-lang/libc/blob/master/src/vxworks/mod.rs) + +The bulk of such a file can be mostly generated from the libc C +headers thanks to the bindgen tool, it then needs to be cleaned up and +integrated into the Rust build infrastructure, some preliminary work had +already been investigated in that part. + +A good level of C programming will be welcome to understand the +questions of ABI and the libc C functions being bound. + +Knowing the Rust language is not required: it can be learnt along the +way, this can be a good occasion. + +Possible mentors: [[Samuel Thibault (youpi)|samuelthibault]] samuel.thibault@gnu.org + +For somebody who has already a very good level of C programming and good Rust +programming skills, this can probably be a 175-hour project. Otherwise it will +be a good occasion to learn, and can then be a 350-hour project. + +It is expected to be of medium difficulty: a fair part of the port is about +mimicing other ports. Deciding how to mimic can be discussed with the community +anyway. The other part is about expressing the C ABI. This requires to properly +understand what that means, but once that is understood, it should be relatively +straightforward to implement. + +You can contact the bug-hurd@gnu.org mailing list to discuss about this project. + +Bonding exercise: Building the Debian rustc package on Debian GNU/Linux. +Building some Debian package (not rustc) on Debian GNU/Hurd. +Have a look at the [initial attempt against rustc 1.30](https://people.debian.org/~sthibault/hurd-i386/rustc-1.30-patch) to get an idea how it looks like, how the ABI gets expressed in Rust. +Then one builds the cross-compiler with + + DEB_BUILD_OPTIONS=parallel=8 dpkg-buildpackage -B -ahurd-i386 -Ppkg.rustc.dlstage0,nocheck -nc + +[Rust language](https://www.rust-lang.org/) + +[How to build and run Rust](https://rustc-dev-guide.rust-lang.org/building/how-to-build-and-run.html) + + +--- + +One can check out the result with: + + git clone https://github.com/sthibaul/getrandom.git + git clone https://github.com/sthibaul/nix.git -b r0.26-hack + git clone https://github.com/sthibaul/rust_libloading.git -b v0.7-hack + git clone https://github.com/sthibaul/rust_libloading.git -b hack rust_libloading-0.8.0 + git clone https://github.com/sthibaul/socket2.git -b v0.4.x + git clone https://github.com/Vtewari2311/libc.git -b libc-hurd-latest-hack + git clone https://github.com/Vtewari2311/rust.git -b mod-hurd-latest-hack + +(yes, rust imposes checking out libloading several times...) + +--- + +To build from GNU/Hurd, you will need existing `rustc`/`cargo`/`rustfmt`, you +can e.g. fetch the tarball +[from Samuel](https://people.debian.org/~sthibault/hurd-i386/rust-hurd.tar.xz). +Then you can add the following to `rust/config.toml` + + [build] + rustc = "/path/to/your/rust-hurd/usr/local/bin/rustc" + rustfmt = "/path/to/your/rust-hurd/usr/local/bin/rustfmt" + cargo = "/path/to/your/rust-hurd/usr/local/bin/cargo" + +And then run from `rust/` + + ./x build + DESTDIR=/where/you/want ./x install + DESTDIR=/where/you/want ./x install cargo rustfmt + +Expect about 20GB disk usage and several hours duration. You also need quite +some ram, 4GB may be needed. + +One can run the basic testsuites with + + ./x test tests/ui + ./x test library/core + ./x test library/std + +One [can run tests remotely](https://rustc-dev-guide.rust-lang.org/tests/running.html#running-tests-on-a-remote-machine), +to test with crossbuilding: + + ./x build src/tools/remote-test-server --target i686-unknown-hurd-gnu + +One can run it on the target: + + ./remote-test-server -v --bind 0.0.0.0:12345 + +and run the testsuite with + + export TEST_DEVICE_ADDR="1.2.3.4:12345" + ./x test tests/ui --target i686-unknown-hurd-gnu + +Currently these tests are known to fail: + +tests/ui: + + [ui] tests/ui/abi/homogenous-floats-target-feature-mixup.rs + [ui] tests/ui/associated-consts/issue-93775.rs + [ui] tests/ui/env-funky-keys.rs + [ui] tests/ui/issues/issue-74564-if-expr-stack-overflow.rs + [ui] tests/ui/macros/macros-nonfatal-errors.rs + [ui] tests/ui/modules/path-no-file-name.rs + [ui] tests/ui/parser/mod_file_with_path_attr.rs + [ui] tests/ui/process/no-stdio.rs#mir + [ui] tests/ui/process/no-stdio.rs#thir + [ui] tests/ui/process/println-with-broken-pipe.rs + [ui] tests/ui/sse2.rs + [ui] tests/ui/traits/object/print_vtable_sizes.rs + +notably because we have not enabled SSE2 by default, and we have errno values that are different from Linux etc., + +library/std: + + net::tcp::tests::double_bind + net::tcp::tests::test_read_timeout + net::tcp::tests::test_read_with_timeout + net::tcp::tests::timeouts + net::udp::tests::test_read_timeout + net::udp::tests::test_read_with_timeout + net::udp::tests::timeouts + os::unix::net::tests::basic + os::unix::net::tests::test_read_timeout + os::unix::net::tests::test_read_with_timeout + os::unix::net::tests::test_unix_datagram_connect_to_recv_addr + +because pfinet currently lets double-bind on IPv6 addresses, doesn't currently support `SO_SNDTIMEO` / `SO_RCVTIMEO`, and pflocal doesn't support getpeername. + +--- + +To cross-build (e.g. from Linux), you need to set up a cross build toolchain +; a simple way is to use the `build-many-glibcs.py` script as described on +[[hurd/glibc]]. Note that to produce something that can be run even on current +latest Debian, you should be using the `2.37/master` branch. You also need to +comment the `#define ED` from `sysdeps/mach/hurd/bits/errno.h`. + +You also need to unpack a Hurd build of openssl ; a simple way is to take the +debian packages from debian-ports: +[libssl3](http://deb.debian.org/debian-ports/pool-hurd-i386/main/o/openssl/libssl3_3.0.10-1_hurd-i386.deb) +and +[libssl-dev](http://deb.debian.org/debian-ports/pool-hurd-i386/main/o/openssl/libssl-dev_3.0.10-1_hurd-i386.deb) +and unpack them with: + + dpkg-deb -x libssl3_3.0.10-1_hurd-i386.deb /where/you/want + dpkg-deb -x libssl-dev_3.0.10-1_hurd-i386.deb /where/you/want + mv /where/you/want/usr/include/i386-gnu/openssl/* /where/you/want/usr/include/openssl/ + mv /where/you/want/usr/lib/i386-gnu/* /where/you/want/usr/lib/ + +Then you can add the following to `rust/config.toml` + + [llvm] + download-ci-llvm = false + + [target.i686-unknown-hurd-gnu] + cc = "/path/to/your/build-glibc/install/compilers/i686-gnu/bin/i686-glibc-gnu-gcc" + cxx = "/path/to/your/build-glibc/install/compilers/i686-gnu/bin/i686-glibc-gnu-g++" + linker = "/path/to/your/build-glibc/install/compilers/i686-gnu/bin/i686-glibc-gnu-gcc" + +And then run from `rust/` + + export I686_UNKNOWN_HURD_GNU_OPENSSL_DIR=/where/you/want/usr + ./x build --stage 0 compiler library + ./x build --host i686-unknown-hurd-gnu --target i686-unknown-hurd-gnu compiler library cargo rustfmt + DESTDIR=/where/you/want ./x install --host i686-unknown-hurd-gnu --target i686-unknown-hurd-gnu + DESTDIR=/where/you/want ./x install --host i686-unknown-hurd-gnu --target i686-unknown-hurd-gnu cargo rustfmt + +Expect about 25GB disk usage and several hours duration. You also need quite +some ram, 4GB may be needed. Take care if you have many cores and threads, the +parallel build of llvm can be quite demanding, you may want to reduce the number +of available processors (e.g. disabling SMT by prefixing your commands with +`hwloc-bind --no-smt all -- `), so you have more memory per core. + +Note that you will have a usable cross-compiler in +`rust/build/x86_64-unknown-linux-gnu/stage1/bin/rustc` and a native Hurd compiler in +`rust/build/i686-unknown-hurd-gnu/stage2/bin/rustc` |