Re: [PATCH 2/6] kbuild: rust_is_available: print docs reference

[Finn Behrens]

On 9 Jan 2023, at 21:45, Miguel Ojeda wrote:

> People trying out the Rust support in the kernel may get
> warnings and errors from `scripts/rust_is_available.sh`
> from the `rustavailable` target or the build step.
>
> Some of those users may be following the Quick Start guide,
> but others may not (likely those getting warnings from
> the build step instead of the target).
>
> While the messages are fairly clear on what the problem is,
> it may not be clear how to solve the particular issue,
> especially for those not aware of the documentation.
>
> We could add all sorts of details on the script for each one,
> but it is better to point users to the documentation instead,
> where it is easily readable in different formats. It also
> avoids duplication.
>
> Thus add a reference to the documentation whenever the script
> fails or there is at least a warning.
As I always use my systems rustc/bindgen, I always get the warning, which already clutters the build output a bit. But I see why it is helpful, so not a fan, but this patch is reasonable.
>
> Signed-off-by: Miguel Ojeda <ojeda@xxxxxxxxxx>
Reviewed-by: Finn Behrens <fin@xxxxxxxxxxx>

Regards,
Finn
> ---
> Note that is based on top of patch "kbuild: rust: remove -v
> option of scripts/rust_is_available.sh" applied on v6.2-rc3:
> https://lore.kernel.org/rust-for-linux/20230109061436.3146442-1-masahiroy@xxxxxxxxxx/
>
>  scripts/rust_is_available.sh | 17 +++++++++++++++++
>  1 file changed, 17 insertions(+)
>
> diff --git a/scripts/rust_is_available.sh b/scripts/rust_is_available.sh
> index eaeafebf8572..c907cf881c2c 100755
> --- a/scripts/rust_is_available.sh
> +++ b/scripts/rust_is_available.sh
> @@ -21,6 +21,20 @@ get_canonical_version()
>  	echo $((100000 * $1 + 100 * $2 + $3))
>  }
>
> +# Print a reference to the setup guide in the documentation.
> +print_docs_reference()
> +{
> +	echo >&2 "***"
> +	echo >&2 "*** Please see Documentation/rust/quick-start.rst for details"
> +	echo >&2 "*** on how to setup Rust support."
> +	echo >&2 "***"
> +}
> +
> +# If the script fails for any reason, or if there was any warning, then
> +# print a reference to the documentation on exit.
> +warning=0
> +trap 'if [ $? -ne 0 ] || [ $warning -ne 0 ]; then print_docs_reference; fi' EXIT
> +
>  # Check that the Rust compiler exists.
>  if ! command -v "$RUSTC" >/dev/null; then
>  	echo >&2 "***"
> @@ -62,6 +76,7 @@ if [ "$rust_compiler_cversion" -gt "$rust_compiler_min_cversion" ]; then
>  	echo >&2 "***   Your version:     $rust_compiler_version"
>  	echo >&2 "***   Expected version: $rust_compiler_min_version"
>  	echo >&2 "***"
> +	warning=1
>  fi
>
>  # Check that the Rust bindings generator is suitable.
> @@ -89,6 +104,7 @@ if [ "$rust_bindings_generator_cversion" -gt "$rust_bindings_generator_min_cvers
>  	echo >&2 "***   Your version:     $rust_bindings_generator_version"
>  	echo >&2 "***   Expected version: $rust_bindings_generator_min_version"
>  	echo >&2 "***"
> +	warning=1
>  fi
>
>  # Check that the `libclang` used by the Rust bindings generator is suitable.
> @@ -128,6 +144,7 @@ if [ "$cc_name" = Clang ]; then
>  		echo >&2 "***   libclang version: $bindgen_libclang_version"
>  		echo >&2 "***   Clang version:    $clang_version"
>  		echo >&2 "***"
> +		warning=1
>  	fi
>  fi
>
> -- 
> 2.39.0