Build Rust for Linux in PR CI

src/ci/docker/host-x86_64/rfl/Dockerfile

@@ -13,14 +13,16 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
   python3 \
   git \
   cmake \
-  sudo \
   gdb \
   flex \
   bison \
   bc \
-  llvm-17-tools \
+  llvm-17 \
   llvm-17-dev \
-  clang \
+  llvm-17-tools \
+  clang-17 \
+  lld-17 \
+  libelf-dev \
   libedit-dev \
   libssl-dev \
   pkg-config \
@@ -31,6 +33,9 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
 COPY scripts/sccache.sh /scripts/
 RUN sh /scripts/sccache.sh
 
+# RfL needs access to llvm-ar
+ENV PATH="${PATH}:/usr/lib/llvm-17/bin"
+
 # We are disabling CI LLVM since this builder is intentionally using a host
 # LLVM, rather than the typical src/llvm-project LLVM.
 ENV NO_DOWNLOAD_CI_LLVM 1

src/ci/docker/scripts/rfl-build.sh

@@ -2,30 +2,33 @@
 
 set -euo pipefail
 
-LINUX_VERSION=v6.9
+LINUX_VERSION=master
 
-# Build rustc
-../x.py --stage 1 build library/std
-BUILT_RUSTC=$(realpath ./build/x86_64-unknown-linux-gnu/stage1/bin/rustc)
+# Build rustc and rustdoc
+../x.py --stage 1 build library rustdoc
 
-# Install rustup so that we have cargo for installing bindgen
+# Install rustup so that we can use the built toolchain easily
 curl --proto '=https' --tlsv1.2 -sSf -o rustup.sh https://sh.rustup.rs
 sh rustup.sh -y --default-toolchain stable --profile minimal
 
 source /cargo/env
 
+rustup toolchain link local ./build/x86_64-unknown-linux-gnu/stage1
+rustup default local
+
 mkdir -p rfl
 cd rfl
 
 # Download Linux
 git clone --depth 1 --branch ${LINUX_VERSION} \
     https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
 
-# Install bindgen
+# Install bindgen. It needs to be compiled with the same version
+# as will be used for the RfL build.
 cargo install --locked \
     --version $(linux/scripts/min-tool-version.sh bindgen) bindgen-cli
 
-# Configure Linux
+# Configure Rust for Linux
 cat <<EOF > linux/kernel/configs/rfl-for-rust-ci.config
 # CONFIG_RETHUNK is not set
 # CONFIG_X86_KERNEL_IBT is not set
@@ -47,12 +50,12 @@ CONFIG_KUNIT=y
 CONFIG_RUST_KERNEL_DOCTESTS=y
 EOF
 
-make -C linux LLVM=1 RUSTC=${BUILT_RUSTC} -j$(($(nproc) + 1)) \
+make -C linux LLVM=1 -j$(($(nproc) + 1)) \
     rustavailable \
     defconfig \
     rfl-for-rust-ci.config
 
-make -C linux LLVM=1 RUSTC=${BUILT_RUSTC} -j$(($(nproc) + 1)) \
+make -C linux LLVM=1 -j$(($(nproc) + 1)) \
     samples/rust/rust_minimal.o \
     samples/rust/rust_print.o \
     drivers/net/phy/ax88796b_rust.o