I didn't find "Rust support" in "General setup"

[tivrfoa]

Hi!

I'm following: https://github.com/Rust-for-Linux/linux/blob/rust/Documentation/rust/quick-start.rst

make LLVM=1 rustavailable
***
*** Rust compiler 'rustc' is too new. This may or may not work.
***   Your version:     1.61.0
***   Expected version: 1.59.0
***
***
*** Rust bindings generator 'bindgen' is too new. This may or may not work.
***   Your version:     0.59.2
***   Expected version: 0.56.0
***
Rust is available!

Then I run make menuconfig and I didn't find Rust there.

[ojeda]

Could you please search (/) for RUST inside menuconfig and post what it reports in the Depends on line?

Note that CONFIG_RUST depends on CONFIG_RUST_IS_AVAILABLE, but also other bits (that will be reduced over time as much as possible).

In addition, the menuconfig etc. should be done with LLVM=1 too if you intend to compile with LLVM.

Finally, if it is the first time you are trying it, please use the expected versions of the toolchain!

[tivrfoa]

 Symbol: RUST [=n]
  │ Type  : bool
  │ Defined at init/Kconfig:2056
  │   Prompt: Rust support
  │   Depends on: RUST_IS_AVAILABLE [=y] && (ARM64 || CPU_32v6 || CPU_32v6K || PPC64 && CPU_LITTLE_ENDIAN || X86_64 [=y] || RISCV) && !MODVERSIONS [=y] && !GCC_PLUGIN_RANDSTRUCT [=n]
  │   Location:
  │     Main menu
  │ (1)   -> General setup
  │ Selects: CONSTRUCTORS [=n]

Running with LLVM=1 (make LLMV=1 menuconfig) I got:

scripts/Kconfig.include:40: linker 'ld.lld' not found
make[1]: *** [scripts/kconfig/Makefile:48: menuconfig] Error 1
make: *** [Makefile:667: menuconfig] Error 2

I'm searching how to solve this now =)

[ojeda]

So this is the culprit:

!MODVERSIONS [=y]

If you disable MODVERSIONS, you should see the Rust support entry, since all the other dependencies are met.

[ojeda]

As for the linker not found error, you will need to install LLD if you want to use LLVM=1. Please see Documentation/kbuild/llvm.rst.

[tivrfoa]

As for the linker not found error, you will need to install LLD if you want to use LLVM=1. Please see Documentation/kbuild/llvm.rst.

Running with make LD=/usr/bin/ld.lld-11 LLVM=1 menuconfig it worked!

Now I'll try to compile it.
Thank you very much!

[ojeda]

I am glad it helped! :)

[tivrfoa]

Finally, if it is the first time you are trying it, please use the expected versions of the toolchain!

Yes, I think I'll need to do that:

***
*** Rust compiler 'rustc' is too new. This may or may not work.
***   Your version:     1.61.0
***   Expected version: 1.59.0
***
***
*** Rust bindings generator 'bindgen' is too new. This may or may not work.
***   Your version:     0.59.2
***   Expected version: 0.56.0
***
  RUSTC L rust/core.o
  BINDGEN rust/bindings_generated.rs
  BINDGEN rust/bindings_helpers_generated.rs
error[E0501]: cannot borrow `self.iter` as mutable because previous closure requires unique access
   --> /home/lesco/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core/src/iter/adapters/mod.rs:182:9
    |
182 | /         self.iter
183 | |             .try_fold(init, |acc, x| match Try::branch(x) {
    | |              --------       -------- closure construction occurs here
    | |              |
    | |              first borrow later used by call
184 | |                 ControlFlow::Continue(x) => ControlFlow::from_try(f(acc, x)),
185 | |                 ControlFlow::Break(r) => {
186 | |                     *self.residual = Some(r);
    | |                     -------------- first borrow occurs due to use of `self` in closure
187 | |                     ControlFlow::Break(try { acc })
188 | |                 }
189 | |             })
    | |______________^ second borrow occurs here

error[E0500]: closure requires unique access to `self` but it is already borrowed
   --> /home/lesco/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core/src/iter/adapters/mod.rs:183:29
    |
182 | /         self.iter
183 | |             .try_fold(init, |acc, x| match Try::branch(x) {
    | |              --------       ^^^^^^^^ closure construction occurs here
    | |              |
    | |              first borrow later used by call
184 | |                 ControlFlow::Continue(x) => ControlFlow::from_try(f(acc, x)),
185 | |                 ControlFlow::Break(r) => {
186 | |                     *self.residual = Some(r);
    | |                     -------------- second borrow occurs due to use of `self` in closure
187 | |                     ControlFlow::Break(try { acc })
188 | |                 }
189 | |             })
    | |______________- borrow occurs here

error: aborting due to 2 previous errors

Some errors have detailed explanations: E0500, E0501.
For more information about an error, try `rustc --explain E0500`.
make[1]: *** [rust/Makefile:368: rust/core.o] Error 1
make: *** [Makefile:1267: prepare] Error 2

[bjorn3]

Libcore should now be compiled with the 2021 edition. It is currently built for the 2018 edition:

linux/rust/Makefile

Line 366 in 6e0fac6

$(objtree)/rust/core.o: private rustc_target_flags = $(core-cfgs) --edition=2018

[tivrfoa]

Libcore should now be compiled with the 2021 edition. It is currently built for the 2018 edition:

linux/rust/Makefile

Line 366 in 6e0fac6

$(objtree)/rust/core.o: private rustc_target_flags = $(core-cfgs) --edition=2018

I changed to 2021 and got lots of errors.
rust 1.61.0
bindgen 0.59.2

I'll try with the correct versions.
rust-errors-2021.txt

[ojeda]

Libcore should now be compiled with the 2021 edition. It is currently built for the 2018 edition:

Not in 1.59.0, which is the current supported version (of course, you are right that soon we will need to change that bit):

https://github.com/rust-lang/rust/blob/9d1b2106e23b1abd32fce1f17267604a5102f57a/library/core/Cargo.toml#L9

@tivrfoa: the issue is that you are trying to compile with a too-new version, as the script reports. It is possible to fix, but it is not supported (and we do not really want to try to support several Rust versions at the moment). That is why you should use the proper version, unless you want to fix things on your side (which usually involves more changes than just an edition, e.g. alloc changes, possibly removed features, etc.).

[tivrfoa]

It worked with the correct versions: rustc (1.59.0), bindgen (0.56.0) and edition 2018.

make didn't finish yet, but it passed the Rust phase.

Can someone share a minimum '.config' to compile with Rust, please? =)

[ojeda]

Please take a look in the .github/workflows/ folder. For general questions and help, please open a thread in Zulip.