Re: [PATCH v2 03/11] docs: rust: add paragraph about finding a suitable `libclang`

[Nathan Chancellor <nathan@kernel.org>]

On Fri, Jun 16, 2023 at 02:16:23AM +0200, Miguel Ojeda wrote:
> Sometimes users need to tweak the finding process of `libclang`
> for `bindgen` via the `clang-sys`-provided environment variables.
> 
> Thus add a paragraph to the setting up guide, including a reference
> to `clang-sys`'s relevant documentation.
> 
> Link: https://lore.kernel.org/rust-for-linux/CAKwvOdm5JT4wbdQQYuW+RT07rCi6whGBM2iUAyg8A1CmLXG6Nw@mail.gmail.com/
> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
> Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Reviewed-by: Nathan Chancellor <nathan@kernel.org>

> ---
>  Documentation/rust/quick-start.rst | 17 +++++++++++++++++
>  1 file changed, 17 insertions(+)
> 
> diff --git a/Documentation/rust/quick-start.rst b/Documentation/rust/quick-start.rst
> index 13b7744b1e27..a635be69e062 100644
> --- a/Documentation/rust/quick-start.rst
> +++ b/Documentation/rust/quick-start.rst
> @@ -100,6 +100,23 @@ Install it via (note that this will download and build the tool from source)::
>  
>  	cargo install --locked --version $(scripts/min-tool-version.sh bindgen) bindgen
>  
> +``bindgen`` needs to find a suitable ``libclang`` in order to work. If it is
> +not found (or a different ``libclang`` than the one found should be used),
> +the process can be tweaked using the environment variables understood by
> +``clang-sys`` (the Rust bindings crate that ``bindgen`` uses to access
> +``libclang``):
> +
> +* ``LLVM_CONFIG_PATH`` can be pointed to an ``llvm-config`` executable.
> +
> +* Or ``LIBCLANG_PATH`` can be pointed to a ``libclang`` shared library
> +  or to the directory containing it.
> +
> +* Or ``CLANG_PATH`` can be pointed to a ``clang`` executable.
> +
> +For details, please see ``clang-sys``'s documentation at:
> +
> +	https://github.com/KyleMayes/clang-sys#environment-variables
> +
>  
>  Requirements: Developing
>  ------------------------
> -- 
> 2.41.0
>