Auto merge of #125209 - Kobzol:rfl-ci, r=Mark-Simulacrum

Add Rust for Linux `auto` CI job

This PR adds an `auto` CI job that checks if Rust for Linux (RfL) still compiles with the latest version of the compiler and the standard library. If not, we should ideally ping the RfL ping group.

try-job: rfl

3 files changed, 113 insertions, 0 deletions

diff --git a/src/ci/docker/host-x86_64/rfl/Dockerfile b/src/ci/docker/host-x86_64/rfl/Dockerfile
new file mode 100644
index 00000000000..97298519cf2
--- /dev/null
+++ b/src/ci/docker/host-x86_64/rfl/Dockerfile
@@ -0,0 +1,40 @@
+FROM ubuntu:22.04
+
+ARG DEBIAN_FRONTEND=noninteractive
+
+# libclang1 is required for libclang.so, required by bindgen
+# clang, llvm and lld is required by RfL to compile host code
+RUN apt-get update && apt-get install -y --no-install-recommends \
+  g++ \
+  make \
+  ninja-build \
+  file \
+  curl \
+  ca-certificates \
+  python3 \
+  git \
+  cmake \
+  flex \
+  bison \
+  bc \
+  clang-15 \
+  libclang1-15 \
+  llvm-15 \
+  lld-15 \
+  libelf-dev \
+  libedit-dev \
+  libssl-dev \
+  pkg-config \
+  zlib1g-dev \
+  && rm -rf /var/lib/apt/lists/*
+
+COPY scripts/sccache.sh /scripts/
+RUN sh /scripts/sccache.sh
+
+# RfL needs access to cland, lld and llvm tools
+ENV PATH="${PATH}:/usr/lib/llvm-15/bin"
+
+ENV RUST_CONFIGURE_ARGS --build=x86_64-unknown-linux-gnu
+
+COPY /scripts/rfl-build.sh /tmp/rfl-build.sh
+ENV SCRIPT bash /tmp/rfl-build.sh
diff --git a/src/ci/docker/scripts/rfl-build.sh b/src/ci/docker/scripts/rfl-build.sh
new file mode 100755
index 00000000000..da7b029ca73
--- /dev/null
+++ b/src/ci/docker/scripts/rfl-build.sh
@@ -0,0 +1,68 @@
+#!/bin/bash
+
+set -euo pipefail
+
+LINUX_VERSION=c13320499ba0efd93174ef6462ae8a7a2933f6e7
+
+# Build rustc, rustdoc and cargo
+../x.py build --stage 1 library rustdoc
+../x.py build --stage 0 cargo
+
+# Install rustup so that we can use the built toolchain easily, and also
+# install bindgen in an easy way.
+curl --proto '=https' --tlsv1.2 -sSf -o rustup.sh https://sh.rustup.rs
+sh rustup.sh -y --default-toolchain none
+
+source /cargo/env
+
+BUILD_DIR=$(realpath ./build)
+rustup toolchain link local "${BUILD_DIR}"/x86_64-unknown-linux-gnu/stage1
+rustup default local
+
+mkdir -p rfl
+cd rfl
+
+# Remove existing directory to make local builds easier
+rm -rf linux || true
+
+# Download Linux at a specific commit
+mkdir -p linux
+git -C linux init
+git -C linux remote add origin https://github.com/torvalds/linux.git
+git -C linux fetch --depth 1 origin ${LINUX_VERSION}
+git -C linux checkout FETCH_HEAD
+
+# Install bindgen
+"${BUILD_DIR}"/x86_64-unknown-linux-gnu/stage0/bin/cargo install \
+  --version $(linux/scripts/min-tool-version.sh bindgen) \
+  bindgen-cli
+
+# Configure Rust for Linux
+cat <<EOF > linux/kernel/configs/rfl-for-rust-ci.config
+# CONFIG_WERROR is not set
+
+CONFIG_RUST=y
+
+CONFIG_SAMPLES=y
+CONFIG_SAMPLES_RUST=y
+
+CONFIG_SAMPLE_RUST_MINIMAL=m
+CONFIG_SAMPLE_RUST_PRINT=y
+
+CONFIG_RUST_PHYLIB_ABSTRACTIONS=y
+CONFIG_AX88796B_PHY=y
+CONFIG_AX88796B_RUST_PHY=y
+
+CONFIG_KUNIT=y
+CONFIG_RUST_KERNEL_DOCTESTS=y
+EOF
+
+make -C linux LLVM=1 -j$(($(nproc) + 1)) \
+    rustavailable \
+    defconfig \
+    rfl-for-rust-ci.config
+
+make -C linux LLVM=1 -j$(($(nproc) + 1)) \
+    samples/rust/rust_minimal.o \
+    samples/rust/rust_print.o \
+    drivers/net/phy/ax88796b_rust.o
diff --git a/src/ci/github-actions/jobs.yml b/src/ci/github-actions/jobs.yml
index 48c39d2c33e..62836acc2d9 100644
--- a/src/ci/github-actions/jobs.yml
+++ b/src/ci/github-actions/jobs.yml
@@ -465,3 +465,8 @@ auto:
       RUST_CONFIGURE_ARGS: --build=x86_64-pc-windows-msvc --enable-extended --enable-profiler
       SCRIPT: python x.py dist bootstrap --include-default-paths
     <<: *job-windows-8c
+
+  # Tests integration with Rust for Linux.
+  # Builds stage 1 compiler and tries to compile a few RfL examples with it.
+  - image: rfl
+    <<: *job-linux-8c