Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
rust: str: allow `str::Formatter` to format into `&mut [u8]`.
Improve `Formatter` so that it can write to an array or slice buffer.
Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>
Link: https://lore.kernel.org/r/20250902-rnull-up-v6-16-v7-2-b5212cc89b98@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
authored by
Andreas Hindborg
and committed by
Jens Axboe
87482d6d
d5d060d6
+17
-6
+17
-6
rust/kernel/str.rs
+17
-6
rust/kernel/str.rs
···
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fmt::{self, Write},
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prelude::*,
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};
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-
use core::ops::{self, Deref, DerefMut, Index};
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use core::{
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marker::PhantomData,
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ops::{self, Deref, DerefMut, Index},
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};
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/// Byte string without UTF-8 validity guarantee.
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#[repr(transparent)]
···
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/// Allows formatting of [`fmt::Arguments`] into a raw buffer.
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///
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/// Fails if callers attempt to write more than will fit in the buffer.
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pub(crate) struct Formatter(RawFormatter);
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pub(crate) struct Formatter<'a>(RawFormatter, PhantomData<&'a mut ()>);
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impl Formatter {
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impl Formatter<'_> {
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/// Creates a new instance of [`Formatter`] with the given buffer.
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///
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/// # Safety
···
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/// for the lifetime of the returned [`Formatter`].
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pub(crate) unsafe fn from_buffer(buf: *mut u8, len: usize) -> Self {
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// SAFETY: The safety requirements of this function satisfy those of the callee.
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Self(unsafe { RawFormatter::from_buffer(buf, len) })
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Self(unsafe { RawFormatter::from_buffer(buf, len) }, PhantomData)
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}
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/// Create a new [`Self`] instance.
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#[expect(dead_code)]
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pub(crate) fn new(buffer: &mut [u8]) -> Self {
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// SAFETY: `buffer` is valid for writes for the entire length for
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// the lifetime of `Self`.
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unsafe { Formatter::from_buffer(buffer.as_mut_ptr(), buffer.len()) }
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}
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}
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impl Deref for Formatter {
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impl Deref for Formatter<'_> {
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type Target = RawFormatter;
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fn deref(&self) -> &Self::Target {
···
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}
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}
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-
impl fmt::Write for Formatter {
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impl fmt::Write for Formatter<'_> {
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fn write_str(&mut self, s: &str) -> fmt::Result {
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self.0.write_str(s)?;
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