On Fri, Jun 16, 2023 at 9:17 AM Miguel Ojeda <ojeda@xxxxxxxxxx> wrote: > > `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@xxxxxxxxxx> > Link: https://lore.kernel.org/rust-for-linux/CAKwvOdm5JT4wbdQQYuW+RT07rCi6whGBM2iUAyg8A1CmLXG6Nw@xxxxxxxxxxxxxx/ > Reported-by: François Valenduc <francoisvalenduc@xxxxxxxxx> > Closes: https://github.com/Rust-for-Linux/linux/issues/934 > Reported-by: Alexandru Radovici <msg4alex@xxxxxxxxx> > Closes: https://github.com/Rust-for-Linux/linux/pull/921 > Reported-by: Matthew Leach <dev@xxxxxxxxxxxxx> > Closes: https://lore.kernel.org/rust-for-linux/20230507084116.1099067-1-dev@xxxxxxxxxxxxx/ > Fixes: 78521f3399ab ("scripts: add `rust_is_available.sh`") > Signed-off-by: Miguel Ojeda <ojeda@xxxxxxxxxx> > --- Reviewed-by: Masahiro Yamada <masahiroy@xxxxxxxxxx> > scripts/rust_is_available.sh | 22 +++++++++++++++++++++- > 1 file changed, 21 insertions(+), 1 deletion(-) > > diff --git a/scripts/rust_is_available.sh b/scripts/rust_is_available.sh > index 6b8131d5b547..1bdff4472cbe 100755 > --- a/scripts/rust_is_available.sh > +++ b/scripts/rust_is_available.sh > @@ -106,8 +106,28 @@ 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 $0)/rust_is_available_bindgen_libclang.h 2>&1 >/dev/null Nit. To avoid shellcheck warnings, you can quote as follows: "$(dirname "$0")/rust_is_available_bindgen_libclang.h" You can do shellcheck scanning to avoid new warnings. (Of course, 02/11 intentionally unquote $CC, though) > +) || bindgen_libclang_code=$? > +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 \ > -- > 2.41.0 > -- Best Regards Masahiro Yamada
