Re: [PATCH v2 05/11] kbuild: rust_is_available: add check for `bindgen` invocation

[Martin Rodriguez Reboredo]

On 6/15/23 21:16, Miguel Ojeda 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: Martin Rodriguez Reboredo <yakoyoku@xxxxxxxxx>