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Stabilize feature cstr_from_bytes_until_nul #107429

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Feb 9, 2023
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1 change: 0 additions & 1 deletion library/alloc/src/lib.rs
Original file line number Diff line number Diff line change
@@ -116,7 +116,6 @@
#![feature(const_eval_select)]
#![feature(const_pin)]
#![feature(const_waker)]
#![feature(cstr_from_bytes_until_nul)]
#![feature(dispatch_from_dyn)]
#![feature(error_generic_member_access)]
#![feature(error_in_core)]
2 changes: 1 addition & 1 deletion library/core/src/error.rs
Original file line number Diff line number Diff line change
@@ -505,7 +505,7 @@ impl Error for crate::ffi::FromBytesWithNulError {
}
}

#[unstable(feature = "cstr_from_bytes_until_nul", issue = "95027")]
#[stable(feature = "cstr_from_bytes_until_nul", since = "CURRENT_RUSTC_VERSION")]
impl Error for crate::ffi::FromBytesUntilNulError {}

#[unstable(feature = "get_many_mut", issue = "104642")]
11 changes: 5 additions & 6 deletions library/core/src/ffi/c_str.rs
Original file line number Diff line number Diff line change
@@ -150,10 +150,10 @@ impl FromBytesWithNulError {
/// This error is created by the [`CStr::from_bytes_until_nul`] method.
///
#[derive(Clone, PartialEq, Eq, Debug)]
#[unstable(feature = "cstr_from_bytes_until_nul", issue = "95027")]
#[stable(feature = "cstr_from_bytes_until_nul", since = "CURRENT_RUSTC_VERSION")]
pub struct FromBytesUntilNulError(());

#[unstable(feature = "cstr_from_bytes_until_nul", issue = "95027")]
#[stable(feature = "cstr_from_bytes_until_nul", since = "CURRENT_RUSTC_VERSION")]
impl fmt::Display for FromBytesUntilNulError {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(f, "data provided does not contain a nul")
@@ -306,8 +306,6 @@ impl CStr {
///
/// # Examples
/// ```
/// #![feature(cstr_from_bytes_until_nul)]
///
/// use std::ffi::CStr;
///
/// let mut buffer = [0u8; 16];
@@ -322,8 +320,9 @@ impl CStr {
/// assert_eq!(c_str.to_str().unwrap(), "AAAAAAAA");
/// ```
///
#[unstable(feature = "cstr_from_bytes_until_nul", issue = "95027")]
#[rustc_const_unstable(feature = "cstr_from_bytes_until_nul", issue = "95027")]
#[rustc_allow_const_fn_unstable(const_slice_index)]
#[stable(feature = "cstr_from_bytes_until_nul", since = "CURRENT_RUSTC_VERSION")]
#[rustc_const_stable(feature = "cstr_from_bytes_until_nul", since = "CURRENT_RUSTC_VERSION")]
pub const fn from_bytes_until_nul(bytes: &[u8]) -> Result<&CStr, FromBytesUntilNulError> {
let nul_pos = memchr::memchr(0, bytes);
match nul_pos {
15 changes: 12 additions & 3 deletions library/core/src/slice/memchr.rs
Original file line number Diff line number Diff line change
@@ -16,25 +16,29 @@ const USIZE_BYTES: usize = mem::size_of::<usize>();
/// bytes where the borrow propagated all the way to the most significant
/// bit."
#[inline]
#[rustc_const_stable(feature = "const_memchr", since = "1.65.0")]
const fn contains_zero_byte(x: usize) -> bool {
x.wrapping_sub(LO_USIZE) & !x & HI_USIZE != 0
}

#[cfg(target_pointer_width = "16")]
#[inline]
#[cfg(target_pointer_width = "16")]
#[rustc_const_stable(feature = "const_memchr", since = "1.65.0")]
const fn repeat_byte(b: u8) -> usize {
(b as usize) << 8 | b as usize
}

#[cfg(not(target_pointer_width = "16"))]
#[inline]
#[cfg(not(target_pointer_width = "16"))]
#[rustc_const_stable(feature = "const_memchr", since = "1.65.0")]
const fn repeat_byte(b: u8) -> usize {
(b as usize) * (usize::MAX / 255)
}

/// Returns the first index matching the byte `x` in `text`.
#[must_use]
#[inline]
#[must_use]
#[rustc_const_stable(feature = "const_memchr", since = "1.65.0")]
pub const fn memchr(x: u8, text: &[u8]) -> Option<usize> {
// Fast path for small slices.
if text.len() < 2 * USIZE_BYTES {
@@ -45,6 +49,7 @@ pub const fn memchr(x: u8, text: &[u8]) -> Option<usize> {
}

#[inline]
#[rustc_const_stable(feature = "const_memchr", since = "1.65.0")]
const fn memchr_naive(x: u8, text: &[u8]) -> Option<usize> {
let mut i = 0;

@@ -60,6 +65,10 @@ const fn memchr_naive(x: u8, text: &[u8]) -> Option<usize> {
None
}

#[rustc_allow_const_fn_unstable(const_cmp)]
#[rustc_allow_const_fn_unstable(const_slice_index)]
#[rustc_allow_const_fn_unstable(const_align_offset)]
#[rustc_const_stable(feature = "const_memchr", since = "1.65.0")]
const fn memchr_aligned(x: u8, text: &[u8]) -> Option<usize> {
// Scan for a single byte value by reading two `usize` words at a time.
//
1 change: 0 additions & 1 deletion library/std/src/lib.rs
Original file line number Diff line number Diff line change
@@ -278,7 +278,6 @@
#![feature(char_error_internals)]
#![feature(char_internals)]
#![feature(core_intrinsics)]
#![feature(cstr_from_bytes_until_nul)]
#![feature(cstr_internals)]
#![feature(duration_constants)]
#![feature(error_generic_member_access)]
1 change: 0 additions & 1 deletion src/tools/miri/tests/pass-dep/shims/pthreads.rs
Original file line number Diff line number Diff line change
@@ -1,5 +1,4 @@
//@ignore-target-windows: No libc on Windows
#![feature(cstr_from_bytes_until_nul)]
use std::ffi::{CStr, CString};
use std::thread;