kbuild: rust_is_available: add check for `bindgen` invocation

[ Upstream commit 52cae7f28e ]

`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 <ndesaulniers@google.com>
Link: https://lore.kernel.org/rust-for-linux/CAKwvOdm5JT4wbdQQYuW+RT07rCi6whGBM2iUAyg8A1CmLXG6Nw@mail.gmail.com/
Reported-by: François Valenduc <francoisvalenduc@gmail.com>
Closes: https://github.com/Rust-for-Linux/linux/issues/934
Reported-by: Alexandru Radovici <msg4alex@gmail.com>
Closes: https://github.com/Rust-for-Linux/linux/pull/921
Reported-by: Matthew Leach <dev@mattleach.net>
Closes: https://lore.kernel.org/rust-for-linux/20230507084116.1099067-1-dev@mattleach.net/
Fixes: 78521f3399 ("scripts: add `rust_is_available.sh`")
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Reviewed-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/r/20230616001631.463536-6-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Miguel Ojeda 2023-06-16 02:16:25 +02:00 committed by Greg Kroah-Hartman
parent bb15fb4e49
commit 4f8c55ae5d
1 changed files with 21 additions and 1 deletions

View File

@ -90,8 +90,28 @@ if [ "$rust_bindings_generator_cversion" -gt "$rust_bindings_generator_min_cvers
fi
# Check that the `libclang` used by the Rust bindings generator is suitable.
#
# In order to do that, first invoke `bindgen` to get the `libclang` version
# found by `bindgen`. This step may already fail if, for instance, `libclang`
# is not found, thus inform the user in such a case.
bindgen_libclang_output=$( \
LC_ALL=C "$BINDGEN" $(dirname $0)/rust_is_available_bindgen_libclang.h 2>&1 >/dev/null
) || bindgen_libclang_code=$?
if [ -n "$bindgen_libclang_code" ]; then
echo >&2 "***"
echo >&2 "*** Running '$BINDGEN' to check the libclang version (used by the Rust"
echo >&2 "*** bindings generator) failed with code $bindgen_libclang_code. This may be caused by"
echo >&2 "*** a failure to locate libclang. See output and docs below for details:"
echo >&2 "***"
echo >&2 "$bindgen_libclang_output"
echo >&2 "***"
exit 1
fi
# `bindgen` returned successfully, thus use the output to check that the version
# of the `libclang` found by the Rust bindings generator is suitable.
bindgen_libclang_version=$( \
LC_ALL=C "$BINDGEN" $(dirname $0)/rust_is_available_bindgen_libclang.h 2>&1 >/dev/null \
echo "$bindgen_libclang_output" \
| grep -F 'clang version ' \
| grep -oE '[0-9]+\.[0-9]+\.[0-9]+' \
| head -n 1 \