From: Gary Guo <gary@garyguo.net>
To: Miguel Ojeda <ojeda@kernel.org>
Cc: "Wedson Almeida Filho" <wedsonaf@gmail.com>,
"Alex Gaynor" <alex.gaynor@gmail.com>,
"Boqun Feng" <boqun.feng@gmail.com>,
"Björn Roy Baron" <bjorn3_gh@protonmail.com>,
rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org,
patches@lists.linux.dev
Subject: Re: [PATCH v1 19/28] rust: str: add `c_str!` macro
Date: Mon, 14 Nov 2022 14:39:28 +0000 [thread overview]
Message-ID: <20221114143928.4dde6589@GaryWorkstation> (raw)
In-Reply-To: <20221110164152.26136-20-ojeda@kernel.org>
On Thu, 10 Nov 2022 17:41:31 +0100
Miguel Ojeda <ojeda@kernel.org> wrote:
> From: Gary Guo <gary@garyguo.net>
>
> 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 | 32 ++++++++++++++++++++++++++++++++
> 1 file changed, 32 insertions(+)
>
> diff --git a/rust/kernel/str.rs b/rust/kernel/str.rs
> index 3ed685cb5a3c..3fb73b888dce 100644
> --- a/rust/kernel/str.rs
> +++ b/rust/kernel/str.rs
> @@ -128,6 +128,18 @@ impl CStr {
> Ok(unsafe { Self::from_bytes_with_nul_unchecked(bytes) })
> }
>
> + /// Creates a [`CStr`] from a `[u8]`, panic if input is not valid.
> + ///
> + /// This function is only meant to be used by `c_str!` macro, so
> + /// crates using `c_str!` macro don't have to enable `const_panic` feature.
I wrote this code when `const_panic` was not yet stable. Now we have
stable const panic this function could be removed.
> + #[doc(hidden)]
> + pub const fn from_bytes_with_nul_unwrap(bytes: &[u8]) -> &Self {
> + match Self::from_bytes_with_nul(bytes) {
> + Ok(v) => v,
> + Err(_) => panic!("string contains interior NUL"),
> + }
> + }
> +
> /// Creates a [`CStr`] from a `[u8]` without performing any additional
> /// checks.
> ///
> @@ -321,6 +333,26 @@ where
> }
> }
>
> +/// 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 = $crate::str::CStr::from_bytes_with_nul_unwrap(S.as_bytes());
> + C
> + }};
> +}
+#[macro_export]
+macro_rules! c_str {
+ ($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::*;
next prev parent reply other threads:[~2022-11-14 14:40 UTC|newest]
Thread overview: 68+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-10 16:41 [PATCH v1 00/28] Rust core additions Miguel Ojeda
2022-11-10 16:41 ` [PATCH v1 01/28] rust: prelude: split re-exports into groups Miguel Ojeda
2022-11-10 18:05 ` Boqun Feng
2022-11-14 14:40 ` Wei Liu
2022-11-10 16:41 ` [PATCH v1 02/28] rust: print: add more `pr_*!` levels Miguel Ojeda
2022-11-10 18:12 ` Boqun Feng
2022-11-14 14:40 ` Wei Liu
2022-11-14 15:01 ` Sergio González Collado
2022-11-10 16:41 ` [PATCH v1 03/28] rust: print: add `pr_cont!` macro Miguel Ojeda
2022-11-14 14:40 ` Wei Liu
2022-11-14 15:04 ` Sergio González Collado
2022-11-10 16:41 ` [PATCH v1 04/28] rust: samples: add `rust_print` example Miguel Ojeda
2022-11-11 9:40 ` Finn Behrens
2022-11-11 17:31 ` Miguel Ojeda
2022-11-14 14:41 ` Wei Liu
2022-11-21 22:51 ` Sergio González Collado
2022-11-10 16:41 ` [PATCH v1 05/28] rust: macros: add `concat_idents!` proc macro Miguel Ojeda
2022-11-11 9:25 ` Finn Behrens
2022-11-14 14:26 ` Gary Guo
2022-11-14 14:39 ` Björn Roy Baron
2022-11-14 17:22 ` Miguel Ojeda
2022-11-10 16:41 ` [PATCH v1 06/28] rust: macros: add `#[vtable]` " Miguel Ojeda
2022-11-14 15:06 ` Sergio González Collado
2022-11-10 16:41 ` [PATCH v1 07/28] rust: macros: take string literals in `module!` Miguel Ojeda
2022-11-14 14:47 ` Wei Liu
2022-11-14 16:46 ` Miguel Ojeda
2022-11-14 17:25 ` Wei Liu
2022-11-10 16:41 ` [PATCH v1 08/28] rust: error: declare errors using macro Miguel Ojeda
2022-11-14 14:28 ` Gary Guo
2022-11-10 16:41 ` [PATCH v1 09/28] rust: error: add codes from `errno-base.h` Miguel Ojeda
2022-11-14 14:29 ` Gary Guo
2022-11-10 16:41 ` [PATCH v1 10/28] rust: error: add `From` implementations for `Error` Miguel Ojeda
2022-11-11 9:50 ` Finn Behrens
2022-11-10 16:41 ` [PATCH v1 11/28] rust: prelude: add `error::code::*` constant items Miguel Ojeda
2022-11-14 14:32 ` Gary Guo
2022-11-10 16:41 ` [PATCH v1 12/28] rust: alloc: add `RawVec::try_with_capacity_in()` constructor Miguel Ojeda
2022-11-14 14:34 ` Gary Guo
2022-11-10 16:41 ` [PATCH v1 13/28] rust: alloc: add `Vec::try_with_capacity{,_in}()` constructors Miguel Ojeda
2022-11-14 14:35 ` Gary Guo
2022-11-10 16:41 ` [PATCH v1 14/28] rust: str: add `BStr` type Miguel Ojeda
2022-11-10 16:41 ` [PATCH v1 15/28] rust: str: add `b_str!` macro Miguel Ojeda
2022-11-10 16:41 ` [PATCH v1 16/28] rust: str: add `CStr` type Miguel Ojeda
2022-11-10 16:41 ` [PATCH v1 17/28] rust: str: implement several traits for `CStr` Miguel Ojeda
2022-11-10 16:41 ` [PATCH v1 18/28] rust: str: add `CStr` unit tests Miguel Ojeda
2022-11-10 16:41 ` [PATCH v1 19/28] rust: str: add `c_str!` macro Miguel Ojeda
2022-11-14 14:39 ` Gary Guo [this message]
2022-11-14 18:28 ` Miguel Ojeda
2022-11-10 16:41 ` [PATCH v1 20/28] rust: str: add `Formatter` type Miguel Ojeda
2022-11-14 14:42 ` Gary Guo
2022-11-10 16:41 ` [PATCH v1 21/28] rust: str: add `CString` type Miguel Ojeda
2022-11-14 14:53 ` Gary Guo
2022-11-10 16:41 ` [PATCH v1 22/28] rust: str: add `fmt!` macro Miguel Ojeda
2022-11-14 14:58 ` Gary Guo
2022-11-10 16:41 ` [PATCH v1 23/28] rust: std_vendor: add `dbg!` macro based on `std`'s one Miguel Ojeda
2022-11-10 18:01 ` Boqun Feng
2022-11-10 19:14 ` Miguel Ojeda
2022-11-10 19:16 ` Boqun Feng
2022-11-10 19:20 ` Miguel Ojeda
2022-11-10 16:41 ` [PATCH v1 24/28] rust: static_assert: add `static_assert!` macro Miguel Ojeda
2022-11-10 16:41 ` [PATCH v1 25/28] rust: add `build_error` crate Miguel Ojeda
2022-11-14 14:30 ` Wei Liu
2022-11-14 18:22 ` Miguel Ojeda
2022-11-14 21:06 ` Wei Liu
2022-11-10 16:41 ` [PATCH v1 26/28] rust: build_assert: add `build_{error,assert}!` macros Miguel Ojeda
2022-11-10 16:41 ` [PATCH v1 27/28] rust: types: add `Either` type Miguel Ojeda
2022-11-14 14:32 ` Wei Liu
2022-11-10 16:41 ` [PATCH v1 28/28] rust: types: add `Opaque` type Miguel Ojeda
2022-11-14 15:03 ` Gary Guo
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