Re: [PATCH v7] rust: use host dylib naming convention

[Andreas Hindborg <a.hindborg@kernel.org>]

"Tamir Duberstein" <tamird@gmail.com> writes:

> Because the `macros` crate exposes procedural macros, it must be
> compiled as a dynamic library (so it can be loaded by the compiler at
> compile-time).
>
> Before this change the resulting artifact was always named
> `libmacros.so`, which works on hosts where this matches the naming
> convention for dynamic libraries. However the proper name on macOS would
> be `libmacros.dylib`.
>
> This turns out to matter even when the dependency is passed with a path
> (`--extern macros=path/to/libmacros.so` rather than `--extern macros`)
> because rustc uses the file name to infer the type of the library (see
> link). This is because there's no way to specify both the path to and
> the type of the external library via CLI flags. The compiler could
> speculatively parse the file to determine its type, but it does not do
> so today.
>
> This means that libraries that match neither rustc's naming convention
> for static libraries nor the platform's naming convention for dynamic
> libraries are *rejected*.
>
> The only solution I've found is to follow the host platform's naming
> convention. This patch does that by querying the compiler to determine
> the appropriate name for the artifact. This allows the kernel to build
> with CONFIG_RUST=y on macOS.
>
> Link: https://github.com/rust-lang/rust/blob/d829780/compiler/rustc_metadata/src/locator.rs#L728-L752
> Tested-by: Daniel Gomez <da.gomez@samsung.com>
> Co-developed-by: Fiona Behrens <me@kloenk.dev>
> Signed-off-by: Fiona Behrens <me@kloenk.dev>
> Signed-off-by: Tamir Duberstein <tamird@gmail.com>

I don't have a mac to test on, but this does not break anything for me
when building with rust enabled on linux.


Tested-by: Andreas Hindborg <a.hindborg@kernel.org>


Best regards,
Andreas Hindborg