From b18cb00e5a8a1182ef491b770ea1a3dab081dc5b Mon Sep 17 00:00:00 2001
From: Gary Guo <gary@garyguo.net>
Date: Thu, 10 Nov 2022 17:41:31 +0100
Subject: [PATCH] rust: str: add `c_str!` macro
Add `c_str!`, which is a convenience macro that creates a new `CStr`
from a string literal.
It is designed to be similar to a `str` in usage, and it is usable
in const contexts, for instance:
const X: &CStr = c_str!("Example");
Co-developed-by: Alex Gaynor <alex.gaynor@gmail.com>
Signed-off-by: Alex Gaynor <alex.gaynor@gmail.com>
Signed-off-by: Gary Guo <gary@garyguo.net>
[Reworded, adapted for upstream and applied latest changes]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
rust/kernel/str.rs | 23 +++++++++++++++++++++++
1 file changed, 23 insertions(+)
diff --git a/rust/kernel/str.rs b/rust/kernel/str.rs
index 3ed685cb5a3c..a995db36486f 100644
--- a/rust/kernel/str.rs
+++ b/rust/kernel/str.rs
@@ -321,6 +321,29 @@ fn index(&self, index: Idx) -> &Self::Output {
}
}
+/// Creates a new [`CStr`] from a string literal.
+///
+/// The string literal should not contain any `NUL` bytes.
+///
+/// # Examples
+///
+/// ```
+/// # use kernel::c_str;
+/// # use kernel::str::CStr;
+/// const MY_CSTR: &CStr = c_str!("My awesome CStr!");
+/// ```
+#[macro_export]
+macro_rules! c_str {
+ ($str:expr) => {{
+ const S: &str = concat!($str, "\0");
+ const C: &$crate::str::CStr = match $crate::str::CStr::from_bytes_with_nul(S.as_bytes()) {
+ Ok(v) => v,
+ Err(_) => panic!("string contains interior NUL"),
+ };
+ C
+ }};
+}
+
#[cfg(test)]
mod tests {
use super::*;
--
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