Auto merge of rust-lang#131288 - matthiaskrgr:rollup-h0t0v2h, r=matthiaskrgr

Rollup of 5 pull requests

Successful merges:

 - rust-lang#130428 (Stabilize `const_slice_split_at_mut` and `const_slice_first_last_chunk`)
 - rust-lang#131094 (std: replace `LazyBox` with `OnceBox`)
 - rust-lang#131256 (move f16/f128 const fn under f16/f128 feature gate)
 - rust-lang#131278 (remove outdated contribution direction)
 - rust-lang#131286 (Miri subtree update)

r? `@ghost`
`@rustbot` modify labels: rollup

Author: bors

library/core/src/lib.rs

@@ -146,7 +146,6 @@
 #![feature(const_size_of_val)]
 #![feature(const_size_of_val_raw)]
 #![feature(const_slice_from_ref)]
-#![feature(const_slice_split_at_mut)]
 #![feature(const_strict_overflow_ops)]
 #![feature(const_swap)]
 #![feature(const_try)]
@@ -158,8 +157,6 @@
 #![feature(coverage_attribute)]
 #![feature(do_not_recommend)]
 #![feature(duration_consts_float)]
-#![feature(f128_const)]
-#![feature(f16_const)]
 #![feature(internal_impls_macro)]
 #![feature(ip)]
 #![feature(is_ascii_octdigit)]

library/core/src/num/f128.rs

@@ -910,7 +910,7 @@ impl f128 {
     /// ```
     #[inline]
     #[unstable(feature = "f128", issue = "116909")]
-    #[rustc_const_unstable(feature = "f128_const", issue = "116909")]
+    #[rustc_const_unstable(feature = "f128", issue = "116909")]
     #[must_use = "this returns the result of the operation, without modifying the original"]
     pub const fn to_bits(self) -> u128 {
         // SAFETY: `u128` is a plain old datatype so we can always transmute to it.
@@ -959,7 +959,7 @@ impl f128 {
     #[inline]
     #[must_use]
     #[unstable(feature = "f128", issue = "116909")]
-    #[rustc_const_unstable(feature = "f128_const", issue = "116909")]
+    #[rustc_const_unstable(feature = "f128", issue = "116909")]
     pub const fn from_bits(v: u128) -> Self {
         // It turns out the safety issues with sNaN were overblown! Hooray!
         // SAFETY: `u128` is a plain old datatype so we can always transmute from it.
@@ -986,7 +986,7 @@ impl f128 {
     /// ```
     #[inline]
     #[unstable(feature = "f128", issue = "116909")]
-    #[rustc_const_unstable(feature = "f128_const", issue = "116909")]
+    #[rustc_const_unstable(feature = "f128", issue = "116909")]
     #[must_use = "this returns the result of the operation, without modifying the original"]
     pub const fn to_be_bytes(self) -> [u8; 16] {
         self.to_bits().to_be_bytes()
@@ -1012,7 +1012,7 @@ impl f128 {
     /// ```
     #[inline]
     #[unstable(feature = "f128", issue = "116909")]
-    #[rustc_const_unstable(feature = "f128_const", issue = "116909")]
+    #[rustc_const_unstable(feature = "f128", issue = "116909")]
     #[must_use = "this returns the result of the operation, without modifying the original"]
     pub const fn to_le_bytes(self) -> [u8; 16] {
         self.to_bits().to_le_bytes()
@@ -1049,7 +1049,7 @@ impl f128 {
     /// ```
     #[inline]
     #[unstable(feature = "f128", issue = "116909")]
-    #[rustc_const_unstable(feature = "f128_const", issue = "116909")]
+    #[rustc_const_unstable(feature = "f128", issue = "116909")]
     #[must_use = "this returns the result of the operation, without modifying the original"]
     pub const fn to_ne_bytes(self) -> [u8; 16] {
         self.to_bits().to_ne_bytes()
@@ -1077,7 +1077,7 @@ impl f128 {
     #[inline]
     #[must_use]
     #[unstable(feature = "f128", issue = "116909")]
-    #[rustc_const_unstable(feature = "f128_const", issue = "116909")]
+    #[rustc_const_unstable(feature = "f128", issue = "116909")]
     pub const fn from_be_bytes(bytes: [u8; 16]) -> Self {
         Self::from_bits(u128::from_be_bytes(bytes))
     }
@@ -1104,7 +1104,7 @@ impl f128 {
     #[inline]
     #[must_use]
     #[unstable(feature = "f128", issue = "116909")]
-    #[rustc_const_unstable(feature = "f128_const", issue = "116909")]
+    #[rustc_const_unstable(feature = "f128", issue = "116909")]
     pub const fn from_le_bytes(bytes: [u8; 16]) -> Self {
         Self::from_bits(u128::from_le_bytes(bytes))
     }
@@ -1141,7 +1141,7 @@ impl f128 {
     #[inline]
     #[must_use]
     #[unstable(feature = "f128", issue = "116909")]
-    #[rustc_const_unstable(feature = "f128_const", issue = "116909")]
+    #[rustc_const_unstable(feature = "f128", issue = "116909")]
     pub const fn from_ne_bytes(bytes: [u8; 16]) -> Self {
         Self::from_bits(u128::from_ne_bytes(bytes))
     }

library/core/src/num/f16.rs

@@ -896,7 +896,7 @@ impl f16 {
     /// ```
     #[inline]
     #[unstable(feature = "f16", issue = "116909")]
-    #[rustc_const_unstable(feature = "f16_const", issue = "116909")]
+    #[rustc_const_unstable(feature = "f16", issue = "116909")]
     #[must_use = "this returns the result of the operation, without modifying the original"]
     pub const fn to_bits(self) -> u16 {
         // SAFETY: `u16` is a plain old datatype so we can always transmute to it.
@@ -944,7 +944,7 @@ impl f16 {
     #[inline]
     #[must_use]
     #[unstable(feature = "f16", issue = "116909")]
-    #[rustc_const_unstable(feature = "f16_const", issue = "116909")]
+    #[rustc_const_unstable(feature = "f16", issue = "116909")]
     pub const fn from_bits(v: u16) -> Self {
         // It turns out the safety issues with sNaN were overblown! Hooray!
         // SAFETY: `u16` is a plain old datatype so we can always transmute from it.
@@ -970,7 +970,7 @@ impl f16 {
     /// ```
     #[inline]
     #[unstable(feature = "f16", issue = "116909")]
-    #[rustc_const_unstable(feature = "f16_const", issue = "116909")]
+    #[rustc_const_unstable(feature = "f16", issue = "116909")]
     #[must_use = "this returns the result of the operation, without modifying the original"]
     pub const fn to_be_bytes(self) -> [u8; 2] {
         self.to_bits().to_be_bytes()
@@ -995,7 +995,7 @@ impl f16 {
     /// ```
     #[inline]
     #[unstable(feature = "f16", issue = "116909")]
-    #[rustc_const_unstable(feature = "f16_const", issue = "116909")]
+    #[rustc_const_unstable(feature = "f16", issue = "116909")]
     #[must_use = "this returns the result of the operation, without modifying the original"]
     pub const fn to_le_bytes(self) -> [u8; 2] {
         self.to_bits().to_le_bytes()
@@ -1033,7 +1033,7 @@ impl f16 {
     /// ```
     #[inline]
     #[unstable(feature = "f16", issue = "116909")]
-    #[rustc_const_unstable(feature = "f16_const", issue = "116909")]
+    #[rustc_const_unstable(feature = "f16", issue = "116909")]
     #[must_use = "this returns the result of the operation, without modifying the original"]
     pub const fn to_ne_bytes(self) -> [u8; 2] {
         self.to_bits().to_ne_bytes()
@@ -1057,7 +1057,7 @@ impl f16 {
     #[inline]
     #[must_use]
     #[unstable(feature = "f16", issue = "116909")]
-    #[rustc_const_unstable(feature = "f16_const", issue = "116909")]
+    #[rustc_const_unstable(feature = "f16", issue = "116909")]
     pub const fn from_be_bytes(bytes: [u8; 2]) -> Self {
         Self::from_bits(u16::from_be_bytes(bytes))
     }
@@ -1080,7 +1080,7 @@ impl f16 {
     #[inline]
     #[must_use]
     #[unstable(feature = "f16", issue = "116909")]
-    #[rustc_const_unstable(feature = "f16_const", issue = "116909")]
+    #[rustc_const_unstable(feature = "f16", issue = "116909")]
     pub const fn from_le_bytes(bytes: [u8; 2]) -> Self {
         Self::from_bits(u16::from_le_bytes(bytes))
     }
@@ -1114,7 +1114,7 @@ impl f16 {
     #[inline]
     #[must_use]
     #[unstable(feature = "f16", issue = "116909")]
-    #[rustc_const_unstable(feature = "f16_const", issue = "116909")]
+    #[rustc_const_unstable(feature = "f16", issue = "116909")]
     pub const fn from_ne_bytes(bytes: [u8; 2]) -> Self {
         Self::from_bits(u16::from_ne_bytes(bytes))
     }

library/core/src/slice/mod.rs

@@ -356,7 +356,8 @@ impl<T> [T] {
     /// ```
     #[inline]
     #[stable(feature = "slice_first_last_chunk", since = "1.77.0")]
-    #[rustc_const_unstable(feature = "const_slice_first_last_chunk", issue = "111774")]
+    #[rustc_const_stable(feature = "const_slice_first_last_chunk", since = "CURRENT_RUSTC_VERSION")]
+    #[cfg_attr(bootstrap, rustc_allow_const_fn_unstable(const_mut_refs))]
     pub const fn first_chunk_mut<const N: usize>(&mut self) -> Option<&mut [T; N]> {
         if self.len() < N {
             None
@@ -421,7 +422,8 @@ impl<T> [T] {
     /// ```
     #[inline]
     #[stable(feature = "slice_first_last_chunk", since = "1.77.0")]
-    #[rustc_const_unstable(feature = "const_slice_first_last_chunk", issue = "111774")]
+    #[rustc_const_stable(feature = "const_slice_first_last_chunk", since = "CURRENT_RUSTC_VERSION")]
+    #[cfg_attr(bootstrap, rustc_allow_const_fn_unstable(const_mut_refs))]
     pub const fn split_first_chunk_mut<const N: usize>(
         &mut self,
     ) -> Option<(&mut [T; N], &mut [T])> {
@@ -491,7 +493,8 @@ impl<T> [T] {
     /// ```
     #[inline]
     #[stable(feature = "slice_first_last_chunk", since = "1.77.0")]
-    #[rustc_const_unstable(feature = "const_slice_first_last_chunk", issue = "111774")]
+    #[rustc_const_stable(feature = "const_slice_first_last_chunk", since = "CURRENT_RUSTC_VERSION")]
+    #[cfg_attr(bootstrap, rustc_allow_const_fn_unstable(const_mut_refs))]
     pub const fn split_last_chunk_mut<const N: usize>(
         &mut self,
     ) -> Option<(&mut [T], &mut [T; N])> {
@@ -560,7 +563,8 @@ impl<T> [T] {
     /// ```
     #[inline]
     #[stable(feature = "slice_first_last_chunk", since = "1.77.0")]
-    #[rustc_const_unstable(feature = "const_slice_first_last_chunk", issue = "111774")]
+    #[rustc_const_stable(feature = "const_slice_first_last_chunk", since = "CURRENT_RUSTC_VERSION")]
+    #[cfg_attr(bootstrap, rustc_allow_const_fn_unstable(const_mut_refs))]
     pub const fn last_chunk_mut<const N: usize>(&mut self) -> Option<&mut [T; N]> {
         if self.len() < N {
             None
@@ -1903,7 +1907,8 @@ impl<T> [T] {
     #[inline]
     #[track_caller]
     #[must_use]
-    #[rustc_const_unstable(feature = "const_slice_split_at_mut", issue = "101804")]
+    #[rustc_const_stable(feature = "const_slice_split_at_mut", since = "CURRENT_RUSTC_VERSION")]
+    #[cfg_attr(bootstrap, rustc_allow_const_fn_unstable(const_mut_refs))]
     pub const fn split_at_mut(&mut self, mid: usize) -> (&mut [T], &mut [T]) {
         match self.split_at_mut_checked(mid) {
             Some(pair) => pair,
@@ -2005,7 +2010,8 @@ impl<T> [T] {
     /// assert_eq!(v, [1, 2, 3, 4, 5, 6]);
     /// ```
     #[stable(feature = "slice_split_at_unchecked", since = "1.79.0")]
-    #[rustc_const_unstable(feature = "const_slice_split_at_mut", issue = "101804")]
+    #[rustc_const_stable(feature = "const_slice_split_at_mut", since = "CURRENT_RUSTC_VERSION")]
+    #[cfg_attr(bootstrap, rustc_allow_const_fn_unstable(const_mut_refs))]
     #[inline]
     #[must_use]
     pub const unsafe fn split_at_mut_unchecked(&mut self, mid: usize) -> (&mut [T], &mut [T]) {
@@ -2105,7 +2111,8 @@ impl<T> [T] {
     /// assert_eq!(None, v.split_at_mut_checked(7));
     /// ```
     #[stable(feature = "split_at_checked", since = "1.80.0")]
-    #[rustc_const_unstable(feature = "const_slice_split_at_mut", issue = "101804")]
+    #[rustc_const_stable(feature = "const_slice_split_at_mut", since = "CURRENT_RUSTC_VERSION")]
+    #[cfg_attr(bootstrap, rustc_allow_const_fn_unstable(const_mut_refs))]
     #[inline]
     #[must_use]
     pub const fn split_at_mut_checked(&mut self, mid: usize) -> Option<(&mut [T], &mut [T])> {

library/std/src/sys/sync/condvar/mod.rs

@@ -12,7 +12,10 @@ cfg_if::cfg_if! {
     ))] {
         mod futex;
         pub use futex::Condvar;
-    } else if #[cfg(target_family = "unix")] {
+    } else if #[cfg(any(
+        target_family = "unix",
+        target_os = "teeos",
+    ))] {
         mod pthread;
         pub use pthread::Condvar;
     } else if #[cfg(all(target_os = "windows", target_vendor = "win7"))] {
@@ -24,9 +27,6 @@ cfg_if::cfg_if! {
     } else if #[cfg(target_os = "solid_asp3")] {
         mod itron;
         pub use itron::Condvar;
-    } else if #[cfg(target_os = "teeos")] {
-        mod teeos;
-        pub use teeos::Condvar;
     } else if #[cfg(target_os = "xous")] {
         mod xous;
         pub use xous::Condvar;

library/std/src/sys/sync/condvar/pthread.rs

@@ -2,31 +2,25 @@ use crate::cell::UnsafeCell;
 use crate::ptr;
 use crate::sync::atomic::AtomicPtr;
 use crate::sync::atomic::Ordering::Relaxed;
-use crate::sys::sync::{Mutex, mutex};
+use crate::sys::sync::{Mutex, OnceBox};
 #[cfg(not(target_os = "nto"))]
 use crate::sys::time::TIMESPEC_MAX;
 #[cfg(target_os = "nto")]
 use crate::sys::time::TIMESPEC_MAX_CAPPED;
-use crate::sys_common::lazy_box::{LazyBox, LazyInit};
 use crate::time::Duration;
 
 struct AllocatedCondvar(UnsafeCell<libc::pthread_cond_t>);
 
 pub struct Condvar {
-    inner: LazyBox<AllocatedCondvar>,
+    inner: OnceBox<AllocatedCondvar>,
     mutex: AtomicPtr<libc::pthread_mutex_t>,
 }
 
-#[inline]
-fn raw(c: &Condvar) -> *mut libc::pthread_cond_t {
-    c.inner.0.get()
-}
-
 unsafe impl Send for AllocatedCondvar {}
 unsafe impl Sync for AllocatedCondvar {}
 
-impl LazyInit for AllocatedCondvar {
-    fn init() -> Box<Self> {
+impl AllocatedCondvar {
+    fn new() -> Box<Self> {
         let condvar = Box::new(AllocatedCondvar(UnsafeCell::new(libc::PTHREAD_COND_INITIALIZER)));
 
         cfg_if::cfg_if! {
@@ -37,7 +31,7 @@ impl LazyInit for AllocatedCondvar {
                 target_vendor = "apple",
             ))] {
                 // `pthread_condattr_setclock` is unfortunately not supported on these platforms.
-            } else if #[cfg(any(target_os = "espidf", target_os = "horizon"))] {
+            } else if #[cfg(any(target_os = "espidf", target_os = "horizon", target_os = "teeos"))] {
                 // NOTE: ESP-IDF's PTHREAD_COND_INITIALIZER support is not released yet
                 // So on that platform, init() should always be called
                 // Moreover, that platform does not have pthread_condattr_setclock support,
@@ -82,7 +76,11 @@ impl Drop for AllocatedCondvar {
 
 impl Condvar {
     pub const fn new() -> Condvar {
-        Condvar { inner: LazyBox::new(), mutex: AtomicPtr::new(ptr::null_mut()) }
+        Condvar { inner: OnceBox::new(), mutex: AtomicPtr::new(ptr::null_mut()) }
+    }
+
+    fn get(&self) -> *mut libc::pthread_cond_t {
+        self.inner.get_or_init(AllocatedCondvar::new).0.get()
     }
 
     #[inline]
@@ -98,21 +96,21 @@ impl Condvar {
 
     #[inline]
     pub fn notify_one(&self) {
-        let r = unsafe { libc::pthread_cond_signal(raw(self)) };
+        let r = unsafe { libc::pthread_cond_signal(self.get()) };
         debug_assert_eq!(r, 0);
     }
 
     #[inline]
     pub fn notify_all(&self) {
-        let r = unsafe { libc::pthread_cond_broadcast(raw(self)) };
+        let r = unsafe { libc::pthread_cond_broadcast(self.get()) };
         debug_assert_eq!(r, 0);
     }
 
     #[inline]
     pub unsafe fn wait(&self, mutex: &Mutex) {
-        let mutex = mutex::raw(mutex);
+        let mutex = mutex.get_assert_locked();
         self.verify(mutex);
-        let r = libc::pthread_cond_wait(raw(self), mutex);
+        let r = libc::pthread_cond_wait(self.get(), mutex);
         debug_assert_eq!(r, 0);
     }
 
@@ -129,7 +127,7 @@ impl Condvar {
     pub unsafe fn wait_timeout(&self, mutex: &Mutex, dur: Duration) -> bool {
         use crate::sys::time::Timespec;
 
-        let mutex = mutex::raw(mutex);
+        let mutex = mutex.get_assert_locked();
         self.verify(mutex);
 
         #[cfg(not(target_os = "nto"))]
@@ -144,7 +142,7 @@ impl Condvar {
             .and_then(|t| t.to_timespec_capped())
             .unwrap_or(TIMESPEC_MAX_CAPPED);
 
-        let r = libc::pthread_cond_timedwait(raw(self), mutex, &timeout);
+        let r = libc::pthread_cond_timedwait(self.get(), mutex, &timeout);
         assert!(r == libc::ETIMEDOUT || r == 0);
         r == 0
     }
@@ -162,7 +160,7 @@ impl Condvar {
         use crate::sys::time::SystemTime;
         use crate::time::Instant;
 
-        let mutex = mutex::raw(mutex);
+        let mutex = mutex.get_assert_locked();
         self.verify(mutex);
 
         // OSX implementation of `pthread_cond_timedwait` is buggy
@@ -188,7 +186,7 @@ impl Condvar {
             .and_then(|t| t.to_timespec())
             .unwrap_or(TIMESPEC_MAX);
 
-        let r = libc::pthread_cond_timedwait(raw(self), mutex, &timeout);
+        let r = libc::pthread_cond_timedwait(self.get(), mutex, &timeout);
         debug_assert!(r == libc::ETIMEDOUT || r == 0);
 
         // ETIMEDOUT is not a totally reliable method of determining timeout due