From 93dc3be19450447a3a7090bd1dfb9f3daac3e8d2 Mon Sep 17 00:00:00 2001 From: Miguel Ojeda Date: Mon, 2 Sep 2024 18:55:33 +0200 Subject: [PATCH] docs: rust: include other expressions in conditional compilation section Expand the conditional compilation section to explain how to support other expressions, such as testing whether `RUSTC_VERSION` is at least a given version, which requires a numerical comparison that Rust's `cfg` predicates do not support (yet?). Reviewed-by: Nicolas Schier Tested-by: Alice Ryhl Acked-by: Masahiro Yamada Link: https://lore.kernel.org/r/20240902165535.1101978-7-ojeda@kernel.org Signed-off-by: Miguel Ojeda --- Documentation/rust/general-information.rst | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/Documentation/rust/general-information.rst b/Documentation/rust/general-information.rst index 2d76e09da121..6146b49b6a98 100644 --- a/Documentation/rust/general-information.rst +++ b/Documentation/rust/general-information.rst @@ -151,3 +151,11 @@ configuration: #[cfg(CONFIG_X="y")] // Enabled as a built-in (`y`) #[cfg(CONFIG_X="m")] // Enabled as a module (`m`) #[cfg(not(CONFIG_X))] // Disabled + +For other predicates that Rust's ``cfg`` does not support, e.g. expressions with +numerical comparisons, one may define a new Kconfig symbol: + +.. code-block:: kconfig + + config RUSTC_VERSION_MIN_107900 + def_bool y if RUSTC_VERSION >= 107900