kernel/linux.git/scripts/rust_is_available.sh, branch v6.12.80

rust: warn about `bindgen` versions 0.66.0 and 0.66.1

2024-07-10T08:28:52+00:00

`bindgen` versions 0.66.0 and 0.66.1 panic due to C string literals with NUL characters [1]: panicked at .cargo/registry/src/index.crates.io-6f17d22bba15001f/bindgen-0.66.0/codegen/mod.rs:717:71: called `Result::unwrap()` on an `Err` value: FromBytesWithNulError { kind: InteriorNul(4) } Thus, in preparation for supporting several `bindgen` versions, add a version check to warn the user about it. Since some distributions may have patched it (e.g. Debian did [2]), check if that seems to be the case (after the version check matches), in order to avoid printing a warning in that case. We could make it an error, but 1) it is going to fail anyway later in the build, 2) we would disable `RUST`, which is also painful, 3) someone could have patched it in a way that still makes our extra check fail (however unlikely), 4) the interior NUL may go away in the headers (however unlikely). Thus just warn about it so that users know why it is failing. In addition, add a couple tests for the new cases. Link: https://github.com/rust-lang/rust-bindgen/pull/2567 [1] Link: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1069047 [2] Link: https://lore.kernel.org/r/20240709160615.998336-11-ojeda@kernel.org Signed-off-by: Miguel Ojeda

rust: start supporting several `bindgen` versions

2024-07-10T08:28:52+00:00

With both the workaround for `bindgen` 0.69.0 and the warning about 0.66.0 and 0.66.1 in place, start supporting several `bindgen` versions, like it was done for the Rust compiler in a previous patch. All other versions, including the latest 0.69.4, build without errors. The `bindgen` project, like Rust, has also agreed to have the kernel in their CI [1] -- thanks! This should help both projects: `bindgen` will be able to detect early issues like those mentioned above, and the kernel will be very likely build with new releases (at least for the basic configuration being tested). Link: https://github.com/rust-lang/rust-bindgen/pull/2851 [1] Tested-by: Benno Lossin Tested-by: Andreas Hindborg Link: https://lore.kernel.org/r/20240709160615.998336-10-ojeda@kernel.org Signed-off-by: Miguel Ojeda

rust: work around `bindgen` 0.69.0 issue

2024-07-10T08:28:52+00:00

`bindgen` 0.69.0 contains a bug: `--version` does not work without providing a header [1]: error: the following required arguments were not provided:

Usage: bindgen

-- ... Thus, in preparation for supporting several `bindgen` versions, work around the issue by passing a dummy argument. Include a comment so that we can remove the workaround in the future. Link: https://github.com/rust-lang/rust-bindgen/pull/2678 [1] Reviewed-by: Finn Behrens Tested-by: Benno Lossin Tested-by: Andreas Hindborg Link: https://lore.kernel.org/r/20240709160615.998336-9-ojeda@kernel.org Signed-off-by: Miguel Ojeda

rust: start supporting several compiler versions

2024-07-10T08:28:52+00:00

It is time to start supporting several Rust compiler versions and thus establish a minimum Rust version. We may still want to upgrade the minimum sometimes in the beginning since there may be important features coming into the language that improve how we write code (e.g. field projections), which may or may not make sense to support conditionally. We will start with a window of two stable releases, and widen it over time. Thus this patch does not move the current minimum (1.78.0), but instead adds support for the recently released 1.79.0. This should already be enough for kernel developers in distributions that provide recent Rust compiler versions routinely, such as Arch Linux, Debian Unstable (outside the freeze period), Fedora Linux, Gentoo Linux (especially the testing channel), Nix (unstable) and openSUSE Tumbleweed. See the documentation patch about it later in this series. In addition, Rust for Linux is now being built-tested in Rust's pre-merge CI [1]. That is, every change that is attempting to land into the Rust compiler is tested against the kernel, and it is merged only if it passes -- thanks to the Rust project for that! Thus, with the pre-merge CI in place, both projects hope to avoid unintentional changes to Rust that break the kernel. This means that, in general, apart from intentional changes on their side (that we will need to workaround conditionally on our side), the upcoming Rust compiler versions should generally work. For instance, currently, the beta (1.80.0) and nightly (1.81.0) branches work as well. Of course, the Rust for Linux CI job in the Rust toolchain may still need to be temporarily disabled for different reasons, but the intention is to help bring Rust for Linux into stable Rust. Link: https://github.com/rust-lang/rust/pull/125209 [1] Reviewed-by: Finn Behrens Tested-by: Benno Lossin Tested-by: Andreas Hindborg Link: https://lore.kernel.org/r/20240709160615.998336-7-ojeda@kernel.org Signed-off-by: Miguel Ojeda

kbuild: rust_is_available: check that output looks as expected

2023-08-09T23:18:34+00:00

The script already checks for `$RUSTC` and `$BINDGEN` existing and exiting without failure. However, one may still pass an unexpected binary that does not output what the later parsing expects. The script still successfully reports a failure as expected, but the error is confusing. For instance: $ RUSTC=true BINDGEN=bindgen CC=clang scripts/rust_is_available.sh scripts/rust_is_available.sh: 19: arithmetic expression: expecting primary: "100000 * + 100 * + " *** *** Please see Documentation/rust/quick-start.rst for details *** on how to set up the Rust support. *** Thus add an explicit check and a proper message for unexpected output from the called command. Similarly, do so for the `libclang` version parsing, too. Link: https://lore.kernel.org/rust-for-linux/CAK7LNAQYk6s11MASRHW6oxtkqF00EJVqhHOP=5rynWt-QDUsXw@mail.gmail.com/ Reviewed-by: Nathan Chancellor Reviewed-by: Martin Rodriguez Reboredo Link: https://lore.kernel.org/r/20230616001631.463536-11-ojeda@kernel.org Signed-off-by: Miguel Ojeda

kbuild: rust_is_available: handle failures calling `$RUSTC`/`$BINDGEN`

2023-08-09T23:18:34+00:00

The script already checks if `$RUSTC` and `$BINDGEN` exists via `command`, but the environment variables may point to a non-executable file, or the programs may fail for some other reason. While the script successfully exits with a failure as it should, the error given can be quite confusing depending on the shell and the behavior of its `command`. For instance, with `dash`: $ RUSTC=./mm BINDGEN=bindgen CC=clang scripts/rust_is_available.sh scripts/rust_is_available.sh: 19: arithmetic expression: expecting primary: "100000 * + 100 * + " Thus detect failure exit codes when calling `$RUSTC` and `$BINDGEN` and print a better message, in a similar way to what we do when extracting the `libclang` version found by `bindgen`. Link: https://lore.kernel.org/rust-for-linux/CAK7LNAQYk6s11MASRHW6oxtkqF00EJVqhHOP=5rynWt-QDUsXw@mail.gmail.com/ Reviewed-by: Nathan Chancellor Reviewed-by: Martin Rodriguez Reboredo Link: https://lore.kernel.org/r/20230616001631.463536-10-ojeda@kernel.org Signed-off-by: Miguel Ojeda

kbuild: rust_is_available: normalize version matching

2023-08-09T23:18:34+00:00

In order to match the version string, `sed` is used in a couple cases, and `grep` and `head` in a couple others. Make the script more consistent and easier to understand by using the same method, `sed`, for all of them. This makes the version matching also a bit more strict for the changed cases, since the strings `rustc ` and `bindgen ` will now be required, which should be fine since `rustc` complains if one attempts to call it with another program name, and `bindgen` uses a hardcoded string. In addition, clarify why one of the existing `sed` commands does not provide an address like the others. Reviewed-by: Nathan Chancellor Reviewed-by: Masahiro Yamada Reviewed-by: Martin Rodriguez Reboredo Link: https://lore.kernel.org/r/20230616001631.463536-9-ojeda@kernel.org Signed-off-by: Miguel Ojeda

kbuild: rust_is_available: fix confusion when a version appears in the path

2023-08-09T23:18:22+00:00

`bindgen`'s output for `libclang`'s version check contains paths, which in turn may contain strings that look like version numbers [1][2]: .../6.1.0-dev/.../rust_is_available_bindgen_libclang.h:2:9: warning: clang version 11.1.0 [-W#pragma-messages], err: false which the script will pick up as the version instead of the latter. It is also the case that versions may appear after the actual version (e.g. distribution's version text), which was the reason behind `head` [3]: .../rust-is-available-bindgen-libclang.h:2:9: warning: clang version 13.0.0 (Fedora 13.0.0-3.fc35) [-W#pragma-messages], err: false Thus instead ask for a match after the `clang version` string. Reported-by: Jordan Isaacs Closes: https://github.com/Rust-for-Linux/linux/issues/942 [1] Reported-by: "Ethan D. Twardy" Closes: https://lore.kernel.org/rust-for-linux/20230528131802.6390-2-ethan.twardy@gmail.com/ [2] Reported-by: Tiago Lam Closes: https://github.com/Rust-for-Linux/linux/pull/789 [3] Fixes: 78521f3399ab ("scripts: add `rust_is_available.sh`") Reviewed-by: Martin Rodriguez Reboredo Reviewed-by: Ethan Twardy Tested-by: Ethan Twardy Reviewed-by: Nathan Chancellor Link: https://lore.kernel.org/r/20230616001631.463536-8-ojeda@kernel.org Signed-off-by: Miguel Ojeda

kbuild: rust_is_available: check that environment variables are set

2023-08-09T17:33:31+00:00

Sometimes [1] users may attempt to setup the Rust support by checking what Kbuild does and they end up finding out about `scripts/rust_is_available.sh`. Inevitably, they run the script directly, but unless they setup the required variables, the result of the script is not meaningful. We could add some defaults to the variables, but that could be confusing for those that may override the defaults (compared to their kernel builds), and `$CC` would not be a simple default in any case. Therefore, instead, explicitly check whether the expected variables are set (`$RUSTC`, `$BINDGEN` and `$CC`). If not, print an explanation about the fact that the script is meant to be called from Kbuild, since that is the most likely cause for the variables not being set. Link: https://lore.kernel.org/oe-kbuild-all/Y6r4mXz5NS0+HVXo@zn.tnic/ [1] Reviewed-by: Martin Rodriguez Reboredo Reviewed-by: Nathan Chancellor Link: https://lore.kernel.org/r/20230616001631.463536-7-ojeda@kernel.org Signed-off-by: Miguel Ojeda

kbuild: rust_is_available: add check for `bindgen` invocation

2023-08-09T17:33:31+00:00

`scripts/rust_is_available.sh` calls `bindgen` with a special header in order to check whether the `libclang` version in use is suitable. However, the invocation itself may fail if, for instance, `bindgen` cannot locate `libclang`. This is fine for Kconfig (since the script will still fail and therefore disable Rust as it should), but it is pretty confusing for users of the `rustavailable` target given the error will be unrelated: ./scripts/rust_is_available.sh: 21: arithmetic expression: expecting primary: "100000 * + 100 * + " make: *** [Makefile:1816: rustavailable] Error 2 Instead, run the `bindgen` invocation independently in a previous step, saving its output and return code. If it fails, then show the user a proper error message. Otherwise, continue as usual with the saved output. Since the previous patch we show a reference to the docs, and the docs now explain how `bindgen` looks for `libclang`, thus the error message can leverage the documentation, avoiding duplication here (and making users aware of the setup guide in the documentation). Reported-by: Nick Desaulniers Link: https://lore.kernel.org/rust-for-linux/CAKwvOdm5JT4wbdQQYuW+RT07rCi6whGBM2iUAyg8A1CmLXG6Nw@mail.gmail.com/ Reported-by: François Valenduc Closes: https://github.com/Rust-for-Linux/linux/issues/934 Reported-by: Alexandru Radovici Closes: https://github.com/Rust-for-Linux/linux/pull/921 Reported-by: Matthew Leach Closes: https://lore.kernel.org/rust-for-linux/20230507084116.1099067-1-dev@mattleach.net/ Fixes: 78521f3399ab ("scripts: add `rust_is_available.sh`") Reviewed-by: Martin Rodriguez Reboredo Reviewed-by: Masahiro Yamada Reviewed-by: Nathan Chancellor Link: https://lore.kernel.org/r/20230616001631.463536-6-ojeda@kernel.org Signed-off-by: Miguel Ojeda