[PATCH 0/6] Replace `kernel::str::CStr` with `core::ffi::CStr` (cycle 1)

[Alice Ryhl]

On Fri, Jul 4, 2025 at 10:16 PM Tamir Duberstein <tamird at gmail.com> wrote:
>
> This series makes preparations for the replacement of our custom `CStr`
> type with the analogous type available in `core`.
>
> As this is a large migration that touches many subsystems, it will take
> place in several cycles, each of which may see multiple series:
> 1. introduces facades in the kernel crate that downstream
>    code can reference. [this series]
> 2. migrate downstream code to kernel crate facades. (N series, divided
>    by subsystem).
> 3. replace kernel crate facades to allow `Display`ing foreign types
>    (such as `core::ffi::CStr`). Replace `CStr` with `core::ffi::CStr`.
> 4. migrate uses of `c_str!` to C-String literals. Replace references to
>    `kernel::str::CStr` with `kernel::ffi::CStr`. (N series, divided by
>    subsystem).
> 5. rename `c_str!` to discourage use. Remove `CStr` reexport from
>    `kernel/str.rs`.
>
> Signed-off-by: Tamir Duberstein <tamird at gmail.com>
> ---
> Tamir Duberstein (6):
>       rust: kernel: remove `fmt!`, fix clippy::uninlined-format-args
>       rust: kernel: add `fmt` module
>       rust: use `kernel::{fmt,prelude::fmt!}`
>       rust: str: remove unnecessary qualification
>       rust: add `CStr` methods matching `core::ffi::CStr`
>       rust: use `core::ffi::CStr` method names
>
>  drivers/cpufreq/rcpufreq_dt.rs    |  3 +-
>  drivers/gpu/nova-core/firmware.rs |  5 +-
>  rust/kernel/error.rs              |  8 ++--
>  rust/kernel/fmt.rs                |  7 +++
>  rust/kernel/lib.rs                |  1 +
>  rust/kernel/opp.rs                |  2 +-
>  rust/kernel/prelude.rs            |  2 +-
>  rust/kernel/print.rs              |  6 +--
>  rust/kernel/str.rs                | 97 ++++++++++++++++++++++++---------------
>  samples/rust/rust_print_main.rs   |  2 +-
>  10 files changed, 83 insertions(+), 50 deletions(-)
> ---
> base-commit: 769e324b66b0d92d04f315d0c45a0f72737c7494
> change-id: 20250704-core-cstr-prepare-9b9e6a7bd57e
>
> Best regards,
> --
> Tamir Duberstein <tamird at gmail.com>
>

Reviewed-by: Alice Ryhl <aliceryhl at google.com>