Commit 93dc3be1 authored by Miguel Ojeda's avatar Miguel Ojeda
Browse files

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: default avatarNicolas Schier <nicolas@fjasle.eu>
Tested-by: default avatarAlice Ryhl <aliceryhl@google.com>
Acked-by: default avatarMasahiro Yamada <masahiroy@kernel.org>
Link: https://lore.kernel.org/r/20240902165535.1101978-7-ojeda@kernel.org


Signed-off-by: default avatarMiguel Ojeda <ojeda@kernel.org>
parent aeb0e24a

Documentation/rust/general-information.rst

+8 −0
Original line number Diff line number Diff line
@@ -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