[PATCH v1 08/28] rust: error: declare errors using macro

[Miguel Ojeda <ojeda@kernel.org>]

From: Finn Behrens <me@kloenk.dev>

Add a macro to declare errors, which simplifies the work needed to
add each one, avoids repetition of the code and makes it easier to
change the way they are declared.

Signed-off-by: Finn Behrens <me@kloenk.dev>
[Reworded, adapted for upstream and applied latest changes]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 rust/kernel/error.rs | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/rust/kernel/error.rs b/rust/kernel/error.rs
index 466b2a8fe569..b843f3445483 100644
--- a/rust/kernel/error.rs
+++ b/rust/kernel/error.rs
@@ -8,8 +8,16 @@ use alloc::collections::TryReserveError;
 
 /// Contains the C-compatible error codes.
 pub mod code {
-    /// Out of memory.
-    pub const ENOMEM: super::Error = super::Error(-(crate::bindings::ENOMEM as i32));
+    macro_rules! declare_err {
+        ($err:tt $(,)? $($doc:expr),+) => {
+            $(
+            #[doc = $doc]
+            )*
+            pub const $err: super::Error = super::Error(-(crate::bindings::$err as i32));
+        };
+    }
+
+    declare_err!(ENOMEM, "Out of memory.");
 }
 
 /// Generic integer kernel error.
-- 
2.38.1