Merge from rustc

33 files changed, 479 insertions, 143 deletions

diff --git a/library/std/src/collections/hash/map.rs b/library/std/src/collections/hash/map.rs
index 56d734ba2fb..d2342d8fd51 100644
--- a/library/std/src/collections/hash/map.rs
+++ b/library/std/src/collections/hash/map.rs
@@ -296,10 +296,7 @@ impl<K, V, S> HashMap<K, V, S> {
     /// ```
     #[inline]
     #[stable(feature = "hashmap_build_hasher", since = "1.7.0")]
-    #[rustc_const_stable(
-        feature = "const_collections_with_hasher",
-        since = "CURRENT_RUSTC_VERSION"
-    )]
+    #[rustc_const_stable(feature = "const_collections_with_hasher", since = "1.85.0")]
     pub const fn with_hasher(hash_builder: S) -> HashMap<K, V, S> {
         HashMap { base: base::HashMap::with_hasher(hash_builder) }
     }
diff --git a/library/std/src/collections/hash/set.rs b/library/std/src/collections/hash/set.rs
index bcf6d6b4ccf..bbb6ca23521 100644
--- a/library/std/src/collections/hash/set.rs
+++ b/library/std/src/collections/hash/set.rs
@@ -388,10 +388,7 @@ impl<T, S> HashSet<T, S> {
     /// ```
     #[inline]
     #[stable(feature = "hashmap_build_hasher", since = "1.7.0")]
-    #[rustc_const_stable(
-        feature = "const_collections_with_hasher",
-        since = "CURRENT_RUSTC_VERSION"
-    )]
+    #[rustc_const_stable(feature = "const_collections_with_hasher", since = "1.85.0")]
     pub const fn with_hasher(hasher: S) -> HashSet<T, S> {
         HashSet { base: base::HashSet::with_hasher(hasher) }
     }
diff --git a/library/std/src/env.rs b/library/std/src/env.rs
index 535236ff89a..11a29cdae62 100644
--- a/library/std/src/env.rs
+++ b/library/std/src/env.rs
@@ -622,7 +622,7 @@ impl Error for JoinPathsError {
 ///
 /// In UWP (Universal Windows Platform) targets this function is unimplemented and always returns `None`.
 ///
-/// Before Rust CURRENT_RUSTC_VERSION, this function used to return the value of the 'HOME' environment variable
+/// Before Rust 1.85.0, this function used to return the value of the 'HOME' environment variable
 /// on Windows, which in Cygwin or Mingw environments could return non-standard paths like `/home/you`
 /// instead of `C:\Users\you`.
 ///
diff --git a/library/std/src/f128.rs b/library/std/src/f128.rs
index e93e915159e..4f37e18a8cd 100644
--- a/library/std/src/f128.rs
+++ b/library/std/src/f128.rs
@@ -227,6 +227,7 @@ impl f128 {
     /// ```
     #[inline]
     #[rustc_allow_incoherent_impl]
+    #[doc(alias = "fmaf128", alias = "fusedMultiplyAdd")]
     #[unstable(feature = "f128", issue = "116909")]
     #[must_use = "method returns a new number and does not mutate the original value"]
     pub fn mul_add(self, a: f128, b: f128) -> f128 {
@@ -384,6 +385,7 @@ impl f128 {
     /// # }
     /// ```
     #[inline]
+    #[doc(alias = "squareRoot")]
     #[rustc_allow_incoherent_impl]
     #[unstable(feature = "f128", issue = "116909")]
     #[must_use = "method returns a new number and does not mutate the original value"]
diff --git a/library/std/src/f16.rs b/library/std/src/f16.rs
index 5b7fcaa28e0..42cd6e3fe2a 100644
--- a/library/std/src/f16.rs
+++ b/library/std/src/f16.rs
@@ -228,6 +228,7 @@ impl f16 {
     #[inline]
     #[rustc_allow_incoherent_impl]
     #[unstable(feature = "f16", issue = "116909")]
+    #[doc(alias = "fmaf16", alias = "fusedMultiplyAdd")]
     #[must_use = "method returns a new number and does not mutate the original value"]
     pub fn mul_add(self, a: f16, b: f16) -> f16 {
         unsafe { intrinsics::fmaf16(self, a, b) }
@@ -384,6 +385,7 @@ impl f16 {
     /// # }
     /// ```
     #[inline]
+    #[doc(alias = "squareRoot")]
     #[rustc_allow_incoherent_impl]
     #[unstable(feature = "f16", issue = "116909")]
     #[must_use = "method returns a new number and does not mutate the original value"]
diff --git a/library/std/src/f32.rs b/library/std/src/f32.rs
index 7cb285bbff5..438d77b1626 100644
--- a/library/std/src/f32.rs
+++ b/library/std/src/f32.rs
@@ -210,6 +210,7 @@ impl f32 {
     /// assert_eq!(one_plus_eps * one_minus_eps + minus_one, 0.0);
     /// ```
     #[rustc_allow_incoherent_impl]
+    #[doc(alias = "fmaf", alias = "fusedMultiplyAdd")]
     #[must_use = "method returns a new number and does not mutate the original value"]
     #[stable(feature = "rust1", since = "1.0.0")]
     #[inline]
@@ -360,6 +361,7 @@ impl f32 {
     /// assert!(negative.sqrt().is_nan());
     /// assert!(negative_zero.sqrt() == negative_zero);
     /// ```
+    #[doc(alias = "squareRoot")]
     #[rustc_allow_incoherent_impl]
     #[must_use = "method returns a new number and does not mutate the original value"]
     #[stable(feature = "rust1", since = "1.0.0")]
diff --git a/library/std/src/f64.rs b/library/std/src/f64.rs
index 47163c272de..9bb4bfbab2a 100644
--- a/library/std/src/f64.rs
+++ b/library/std/src/f64.rs
@@ -210,6 +210,7 @@ impl f64 {
     /// assert_eq!(one_plus_eps * one_minus_eps + minus_one, 0.0);
     /// ```
     #[rustc_allow_incoherent_impl]
+    #[doc(alias = "fma", alias = "fusedMultiplyAdd")]
     #[must_use = "method returns a new number and does not mutate the original value"]
     #[stable(feature = "rust1", since = "1.0.0")]
     #[inline]
@@ -360,6 +361,7 @@ impl f64 {
     /// assert!(negative.sqrt().is_nan());
     /// assert!(negative_zero.sqrt() == negative_zero);
     /// ```
+    #[doc(alias = "squareRoot")]
     #[rustc_allow_incoherent_impl]
     #[must_use = "method returns a new number and does not mutate the original value"]
     #[stable(feature = "rust1", since = "1.0.0")]
diff --git a/library/std/src/ffi/os_str.rs b/library/std/src/ffi/os_str.rs
index fff140f1564..7fb57d41043 100644
--- a/library/std/src/ffi/os_str.rs
+++ b/library/std/src/ffi/os_str.rs
@@ -550,7 +550,7 @@ impl OsString {
         OsStr::from_inner_mut(self.inner.leak())
     }
 
-    /// Truncate the the `OsString` to the specified length.
+    /// Truncate the `OsString` to the specified length.
     ///
     /// # Panics
     /// Panics if `len` does not lie on a valid `OsStr` boundary
diff --git a/library/std/src/ffi/os_str/tests.rs b/library/std/src/ffi/os_str/tests.rs
index cbec44c8626..2572b71fd9a 100644
--- a/library/std/src/ffi/os_str/tests.rs
+++ b/library/std/src/ffi/os_str/tests.rs
@@ -295,7 +295,7 @@ fn clone_to_uninit() {
 
     let mut storage = vec![MaybeUninit::<u8>::uninit(); size_of_val::<OsStr>(a)];
     unsafe { a.clone_to_uninit(ptr::from_mut::<[_]>(storage.as_mut_slice()).cast()) };
-    assert_eq!(a.as_encoded_bytes(), unsafe { MaybeUninit::slice_assume_init_ref(&storage) });
+    assert_eq!(a.as_encoded_bytes(), unsafe { storage.assume_init_ref() });
 
     let mut b: Box<OsStr> = OsStr::new("world.exe").into();
     assert_eq!(size_of_val::<OsStr>(a), size_of_val::<OsStr>(&b));
diff --git a/library/std/src/io/buffered/bufreader/buffer.rs b/library/std/src/io/buffered/bufreader/buffer.rs
index 17721090db5..5251cc302cb 100644
--- a/library/std/src/io/buffered/bufreader/buffer.rs
+++ b/library/std/src/io/buffered/bufreader/buffer.rs
@@ -50,7 +50,7 @@ impl Buffer {
     pub fn buffer(&self) -> &[u8] {
         // SAFETY: self.pos and self.cap are valid, and self.cap => self.pos, and
         // that region is initialized because those are all invariants of this type.
-        unsafe { MaybeUninit::slice_assume_init_ref(self.buf.get_unchecked(self.pos..self.filled)) }
+        unsafe { self.buf.get_unchecked(self.pos..self.filled).assume_init_ref() }
     }
 
     #[inline]
diff --git a/library/std/src/io/error.rs b/library/std/src/io/error.rs
index 476c403c21f..38b72336617 100644
--- a/library/std/src/io/error.rs
+++ b/library/std/src/io/error.rs
@@ -339,7 +339,7 @@ pub enum ErrorKind {
     #[stable(feature = "io_error_a_bit_more", since = "1.83.0")]
     NotSeekable,
     /// Filesystem quota or some other kind of quota was exceeded.
-    #[stable(feature = "io_error_quota_exceeded", since = "CURRENT_RUSTC_VERSION")]
+    #[stable(feature = "io_error_quota_exceeded", since = "1.85.0")]
     QuotaExceeded,
     /// File larger than allowed or supported.
     ///
@@ -364,7 +364,7 @@ pub enum ErrorKind {
     #[stable(feature = "io_error_a_bit_more", since = "1.83.0")]
     Deadlock,
     /// Cross-device or cross-filesystem (hard) link or rename.
-    #[stable(feature = "io_error_crosses_devices", since = "CURRENT_RUSTC_VERSION")]
+    #[stable(feature = "io_error_crosses_devices", since = "1.85.0")]
     CrossesDevices,
     /// Too many (hard) links to the same filesystem object.
     ///
diff --git a/library/std/src/io/error/repr_bitpacked.rs b/library/std/src/io/error/repr_bitpacked.rs
index f958a938646..716da37168d 100644
--- a/library/std/src/io/error/repr_bitpacked.rs
+++ b/library/std/src/io/error/repr_bitpacked.rs
@@ -103,7 +103,8 @@
 //! the time.
 
 use core::marker::PhantomData;
-use core::ptr::{self, NonNull};
+use core::num::NonZeroUsize;
+use core::ptr::NonNull;
 
 use super::{Custom, ErrorData, ErrorKind, RawOsError, SimpleMessage};
 
@@ -176,7 +177,7 @@ impl Repr {
         let utagged = ((code as usize) << 32) | TAG_OS;
         // Safety: `TAG_OS` is not zero, so the result of the `|` is not 0.
         let res = Self(
-            unsafe { NonNull::new_unchecked(ptr::without_provenance_mut(utagged)) },
+            NonNull::without_provenance(unsafe { NonZeroUsize::new_unchecked(utagged) }),
             PhantomData,
         );
         // quickly smoke-check we encoded the right thing (This generally will
@@ -193,7 +194,7 @@ impl Repr {
         let utagged = ((kind as usize) << 32) | TAG_SIMPLE;
         // Safety: `TAG_SIMPLE` is not zero, so the result of the `|` is not 0.
         let res = Self(
-            unsafe { NonNull::new_unchecked(ptr::without_provenance_mut(utagged)) },
+            NonNull::without_provenance(unsafe { NonZeroUsize::new_unchecked(utagged) }),
             PhantomData,
         );
         // quickly smoke-check we encoded the right thing (This generally will
diff --git a/library/std/src/lib.rs b/library/std/src/lib.rs
index 2f8f5c5c581..5c12236617c 100644
--- a/library/std/src/lib.rs
+++ b/library/std/src/lib.rs
@@ -342,6 +342,7 @@
 #![feature(lazy_get)]
 #![feature(maybe_uninit_slice)]
 #![feature(maybe_uninit_write_slice)]
+#![feature(nonnull_provenance)]
 #![feature(panic_can_unwind)]
 #![feature(panic_internals)]
 #![feature(pin_coerce_unsized_trait)]
@@ -357,6 +358,7 @@
 #![feature(str_internals)]
 #![feature(strict_provenance_atomic_ptr)]
 #![feature(sync_unsafe_cell)]
+#![feature(temporary_niche_types)]
 #![feature(ub_checks)]
 #![feature(used_with_arg)]
 // tidy-alphabetical-end
diff --git a/library/std/src/os/fd/owned.rs b/library/std/src/os/fd/owned.rs
index abb13b75f50..1e814eca3c1 100644
--- a/library/std/src/os/fd/owned.rs
+++ b/library/std/src/os/fd/owned.rs
@@ -11,6 +11,8 @@ use crate::sys::cvt;
 use crate::sys_common::{AsInner, FromInner, IntoInner};
 use crate::{fmt, fs, io};
 
+type ValidRawFd = core::num::niche_types::NotAllOnes<RawFd>;
+
 /// A borrowed file descriptor.
 ///
 /// This has a lifetime parameter to tie it to the lifetime of something that owns the file
@@ -32,15 +34,10 @@ use crate::{fmt, fs, io};
 /// instead, but this is not supported on all platforms.
 #[derive(Copy, Clone)]
 #[repr(transparent)]
-#[rustc_layout_scalar_valid_range_start(0)]
-// libstd/os/raw/mod.rs assures me that every libstd-supported platform has a
-// 32-bit c_int. Below is -2, in two's complement, but that only works out
-// because c_int is 32 bits.
-#[rustc_layout_scalar_valid_range_end(0xFF_FF_FF_FE)]
 #[rustc_nonnull_optimization_guaranteed]
 #[stable(feature = "io_safety", since = "1.63.0")]
 pub struct BorrowedFd<'fd> {
-    fd: RawFd,
+    fd: ValidRawFd,
     _phantom: PhantomData<&'fd OwnedFd>,
 }
 
@@ -56,15 +53,10 @@ pub struct BorrowedFd<'fd> {
 ///
 /// You can use [`AsFd::as_fd`] to obtain a [`BorrowedFd`].
 #[repr(transparent)]
-#[rustc_layout_scalar_valid_range_start(0)]
-// libstd/os/raw/mod.rs assures me that every libstd-supported platform has a
-// 32-bit c_int. Below is -2, in two's complement, but that only works out
-// because c_int is 32 bits.
-#[rustc_layout_scalar_valid_range_end(0xFF_FF_FF_FE)]
 #[rustc_nonnull_optimization_guaranteed]
 #[stable(feature = "io_safety", since = "1.63.0")]
 pub struct OwnedFd {
-    fd: RawFd,
+    fd: ValidRawFd,
 }
 
 impl BorrowedFd<'_> {
@@ -80,7 +72,8 @@ impl BorrowedFd<'_> {
     pub const unsafe fn borrow_raw(fd: RawFd) -> Self {
         assert!(fd != u32::MAX as RawFd);
         // SAFETY: we just asserted that the value is in the valid range and isn't `-1` (the only value bigger than `0xFF_FF_FF_FE` unsigned)
-        unsafe { Self { fd, _phantom: PhantomData } }
+        let fd = unsafe { ValidRawFd::new_unchecked(fd) };
+        Self { fd, _phantom: PhantomData }
     }
 }
 
@@ -130,7 +123,7 @@ impl BorrowedFd<'_> {
 impl AsRawFd for BorrowedFd<'_> {
     #[inline]
     fn as_raw_fd(&self) -> RawFd {
-        self.fd
+        self.fd.as_inner()
     }
 }
 
@@ -138,7 +131,7 @@ impl AsRawFd for BorrowedFd<'_> {
 impl AsRawFd for OwnedFd {
     #[inline]
     fn as_raw_fd(&self) -> RawFd {
-        self.fd
+        self.fd.as_inner()
     }
 }
 
@@ -146,7 +139,7 @@ impl AsRawFd for OwnedFd {
 impl IntoRawFd for OwnedFd {
     #[inline]
     fn into_raw_fd(self) -> RawFd {
-        ManuallyDrop::new(self).fd
+        ManuallyDrop::new(self).fd.as_inner()
     }
 }
 
@@ -164,7 +157,8 @@ impl FromRawFd for OwnedFd {
     unsafe fn from_raw_fd(fd: RawFd) -> Self {
         assert_ne!(fd, u32::MAX as RawFd);
         // SAFETY: we just asserted that the value is in the valid range and isn't `-1` (the only value bigger than `0xFF_FF_FF_FE` unsigned)
-        unsafe { Self { fd } }
+        let fd = unsafe { ValidRawFd::new_unchecked(fd) };
+        Self { fd }
     }
 }
 
@@ -187,12 +181,12 @@ impl Drop for OwnedFd {
             #[cfg(not(target_os = "hermit"))]
             {
                 #[cfg(unix)]
-                crate::sys::fs::debug_assert_fd_is_open(self.fd);
+                crate::sys::fs::debug_assert_fd_is_open(self.fd.as_inner());
 
-                let _ = libc::close(self.fd);
+                let _ = libc::close(self.fd.as_inner());
             }
             #[cfg(target_os = "hermit")]
-            let _ = hermit_abi::close(self.fd);
+            let _ = hermit_abi::close(self.fd.as_inner());
         }
     }
 }
diff --git a/library/std/src/os/solid/io.rs b/library/std/src/os/solid/io.rs
index 2d18f339615..b8601b533fe 100644
--- a/library/std/src/os/solid/io.rs
+++ b/library/std/src/os/solid/io.rs
@@ -54,6 +54,9 @@ use crate::{fmt, net, sys};
 /// Raw file descriptors.
 pub type RawFd = i32;
 
+// The max of this is -2, in two's complement. -1 is `SOLID_NET_INVALID_FD`.
+type ValidRawFd = core::num::niche_types::NotAllOnes<RawFd>;
+
 /// A borrowed SOLID Sockets file descriptor.
 ///
 /// This has a lifetime parameter to tie it to the lifetime of something that
@@ -69,12 +72,9 @@ pub type RawFd = i32;
 /// socket, which is then borrowed under the same lifetime.
 #[derive(Copy, Clone)]
 #[repr(transparent)]
-#[rustc_layout_scalar_valid_range_start(0)]
-// This is -2, in two's complement. -1 is `SOLID_NET_INVALID_FD`.
-#[rustc_layout_scalar_valid_range_end(0xFF_FF_FF_FE)]
 #[rustc_nonnull_optimization_guaranteed]
 pub struct BorrowedFd<'socket> {
-    fd: RawFd,
+    fd: ValidRawFd,
     _phantom: PhantomData<&'socket OwnedFd>,
 }
 
@@ -87,12 +87,9 @@ pub struct BorrowedFd<'socket> {
 /// an argument, it is not captured or consumed, and it never has the value
 /// `SOLID_NET_INVALID_FD`.
 #[repr(transparent)]
-#[rustc_layout_scalar_valid_range_start(0)]
-// This is -2, in two's complement. -1 is `SOLID_NET_INVALID_FD`.
-#[rustc_layout_scalar_valid_range_end(0xFF_FF_FF_FE)]
 #[rustc_nonnull_optimization_guaranteed]
 pub struct OwnedFd {
-    fd: RawFd,
+    fd: ValidRawFd,
 }
 
 impl BorrowedFd<'_> {
@@ -108,7 +105,8 @@ impl BorrowedFd<'_> {
         assert!(fd != -1 as RawFd);
         // SAFETY: we just asserted that the value is in the valid range and
         // isn't `-1` (the only value bigger than `0xFF_FF_FF_FE` unsigned)
-        unsafe { Self { fd, _phantom: PhantomData } }
+        let fd = unsafe { ValidRawFd::new_unchecked(fd) };
+        Self { fd, _phantom: PhantomData }
     }
 }
 
@@ -132,21 +130,21 @@ impl BorrowedFd<'_> {
 impl AsRawFd for BorrowedFd<'_> {
     #[inline]
     fn as_raw_fd(&self) -> RawFd {
-        self.fd
+        self.fd.as_inner()
     }
 }
 
 impl AsRawFd for OwnedFd {
     #[inline]
     fn as_raw_fd(&self) -> RawFd {
-        self.fd
+        self.fd.as_inner()
     }
 }
 
 impl IntoRawFd for OwnedFd {
     #[inline]
     fn into_raw_fd(self) -> RawFd {
-        ManuallyDrop::new(self).fd
+        ManuallyDrop::new(self).fd.as_inner()
     }
 }
 
@@ -162,14 +160,15 @@ impl FromRawFd for OwnedFd {
         assert_ne!(fd, -1 as RawFd);
         // SAFETY: we just asserted that the value is in the valid range and
         // isn't `-1` (the only value bigger than `0xFF_FF_FF_FE` unsigned)
-        unsafe { Self { fd } }
+        let fd = unsafe { ValidRawFd::new_unchecked(fd) };
+        Self { fd }
     }
 }
 
 impl Drop for OwnedFd {
     #[inline]
     fn drop(&mut self) {
-        unsafe { sys::net::netc::close(self.fd) };
+        unsafe { sys::net::netc::close(self.fd.as_inner()) };
     }
 }
 
diff --git a/library/std/src/os/windows/io/socket.rs b/library/std/src/os/windows/io/socket.rs
index c6d7bad9440..6e13a8b502a 100644
--- a/library/std/src/os/windows/io/socket.rs
+++ b/library/std/src/os/windows/io/socket.rs
@@ -9,6 +9,9 @@ use crate::mem::{self, ManuallyDrop};
 use crate::sys::cvt;
 use crate::{fmt, io, sys};
 
+// The max here is -2, in two's complement. -1 is `INVALID_SOCKET`.
+type ValidRawSocket = core::num::niche_types::NotAllOnes<RawSocket>;
+
 /// A borrowed socket.
 ///
 /// This has a lifetime parameter to tie it to the lifetime of something that
@@ -24,17 +27,10 @@ use crate::{fmt, io, sys};
 /// socket, which is then borrowed under the same lifetime.
 #[derive(Copy, Clone)]
 #[repr(transparent)]
-#[rustc_layout_scalar_valid_range_start(0)]
-// This is -2, in two's complement. -1 is `INVALID_SOCKET`.
-#[cfg_attr(target_pointer_width = "32", rustc_layout_scalar_valid_range_end(0xFF_FF_FF_FE))]
-#[cfg_attr(
-    target_pointer_width = "64",
-    rustc_layout_scalar_valid_range_end(0xFF_FF_FF_FF_FF_FF_FF_FE)
-)]
 #[rustc_nonnull_optimization_guaranteed]
 #[stable(feature = "io_safety", since = "1.63.0")]
 pub struct BorrowedSocket<'socket> {
-    socket: RawSocket,
+    socket: ValidRawSocket,
     _phantom: PhantomData<&'socket OwnedSocket>,
 }
 
@@ -47,17 +43,10 @@ pub struct BorrowedSocket<'socket> {
 /// argument or returned as an owned value, and it never has the value
 /// `INVALID_SOCKET`.
 #[repr(transparent)]
-#[rustc_layout_scalar_valid_range_start(0)]
-// This is -2, in two's complement. -1 is `INVALID_SOCKET`.
-#[cfg_attr(target_pointer_width = "32", rustc_layout_scalar_valid_range_end(0xFF_FF_FF_FE))]
-#[cfg_attr(
-    target_pointer_width = "64",
-    rustc_layout_scalar_valid_range_end(0xFF_FF_FF_FF_FF_FF_FF_FE)
-)]
 #[rustc_nonnull_optimization_guaranteed]
 #[stable(feature = "io_safety", since = "1.63.0")]
 pub struct OwnedSocket {
-    socket: RawSocket,
+    socket: ValidRawSocket,
 }
 
 impl BorrowedSocket<'_> {
@@ -73,7 +62,8 @@ impl BorrowedSocket<'_> {
     #[stable(feature = "io_safety", since = "1.63.0")]
     pub const unsafe fn borrow_raw(socket: RawSocket) -> Self {
         assert!(socket != sys::c::INVALID_SOCKET as RawSocket);
-        unsafe { Self { socket, _phantom: PhantomData } }
+        let socket = unsafe { ValidRawSocket::new_unchecked(socket) };
+        Self { socket, _phantom: PhantomData }
     }
 }
 
@@ -172,7 +162,7 @@ fn last_error() -> io::Error {
 impl AsRawSocket for BorrowedSocket<'_> {
     #[inline]
     fn as_raw_socket(&self) -> RawSocket {
-        self.socket
+        self.socket.as_inner()
     }
 }
 
@@ -180,7 +170,7 @@ impl AsRawSocket for BorrowedSocket<'_> {
 impl AsRawSocket for OwnedSocket {
     #[inline]
     fn as_raw_socket(&self) -> RawSocket {
-        self.socket
+        self.socket.as_inner()
     }
 }
 
@@ -188,7 +178,7 @@ impl AsRawSocket for OwnedSocket {
 impl IntoRawSocket for OwnedSocket {
     #[inline]
     fn into_raw_socket(self) -> RawSocket {
-        ManuallyDrop::new(self).socket
+        ManuallyDrop::new(self).socket.as_inner()
     }
 }
 
@@ -196,10 +186,9 @@ impl IntoRawSocket for OwnedSocket {
 impl FromRawSocket for OwnedSocket {
     #[inline]
     unsafe fn from_raw_socket(socket: RawSocket) -> Self {
-        unsafe {
-            debug_assert_ne!(socket, sys::c::INVALID_SOCKET as RawSocket);
-            Self { socket }
-        }
+        debug_assert_ne!(socket, sys::c::INVALID_SOCKET as RawSocket);
+        let socket = unsafe { ValidRawSocket::new_unchecked(socket) };
+        Self { socket }
     }
 }
 
@@ -208,7 +197,7 @@ impl Drop for OwnedSocket {
     #[inline]
     fn drop(&mut self) {
         unsafe {
-            let _ = sys::c::closesocket(self.socket as sys::c::SOCKET);
+            let _ = sys::c::closesocket(self.socket.as_inner() as sys::c::SOCKET);
         }
     }
 }
diff --git a/library/std/src/path/tests.rs b/library/std/src/path/tests.rs
index ff3f7151bb8..3f96ac4672a 100644
--- a/library/std/src/path/tests.rs
+++ b/library/std/src/path/tests.rs
@@ -2069,9 +2069,7 @@ fn clone_to_uninit() {
 
     let mut storage = vec![MaybeUninit::<u8>::uninit(); size_of_val::<Path>(a)];
     unsafe { a.clone_to_uninit(ptr::from_mut::<[_]>(storage.as_mut_slice()).cast()) };
-    assert_eq!(a.as_os_str().as_encoded_bytes(), unsafe {
-        MaybeUninit::slice_assume_init_ref(&storage)
-    });
+    assert_eq!(a.as_os_str().as_encoded_bytes(), unsafe { storage.assume_init_ref() });
 
     let mut b: Box<Path> = Path::new("world.exe").into();
     assert_eq!(size_of_val::<Path>(a), size_of_val::<Path>(&b));
diff --git a/library/std/src/pipe.rs b/library/std/src/pipe.rs
index 06f3fd9fdff..913c22588a7 100644
--- a/library/std/src/pipe.rs
+++ b/library/std/src/pipe.rs
@@ -97,7 +97,7 @@ impl PipeReader {
     /// let mut jobs = vec![];
     /// let (reader, mut writer) = std::pipe::pipe()?;
     ///
-    /// // Write NUM_SLOT characters the the pipe.
+    /// // Write NUM_SLOT characters the pipe.
     /// writer.write_all(&[b'|'; NUM_SLOT as usize])?;
     ///
     /// // Spawn several processes that read a character from the pipe, do some work, then
diff --git a/library/std/src/prelude/common.rs b/library/std/src/prelude/common.rs
index 22a364074c5..0f2d8334fca 100644
--- a/library/std/src/prelude/common.rs
+++ b/library/std/src/prelude/common.rs
@@ -12,8 +12,7 @@ pub use crate::marker::{Send, Sized, Sync, Unpin};
 #[stable(feature = "rust1", since = "1.0.0")]
 #[doc(no_inline)]
 pub use crate::ops::{Drop, Fn, FnMut, FnOnce};
-#[cfg_attr(bootstrap, unstable(feature = "async_closure", issue = "62290"))]
-#[cfg_attr(not(bootstrap), stable(feature = "async_closure", since = "CURRENT_RUSTC_VERSION"))]
+#[stable(feature = "async_closure", since = "1.85.0")]
 #[doc(no_inline)]
 pub use crate::ops::{AsyncFn, AsyncFnMut, AsyncFnOnce};
 
diff --git a/library/std/src/prelude/mod.rs b/library/std/src/prelude/mod.rs
index 64349987fcf..4ec328208f0 100644
--- a/library/std/src/prelude/mod.rs
+++ b/library/std/src/prelude/mod.rs
@@ -169,12 +169,12 @@ pub mod rust_2021 {
 /// The 2024 version of the prelude of The Rust Standard Library.
 ///
 /// See the [module-level documentation](self) for more.
-#[stable(feature = "prelude_2024", since = "CURRENT_RUSTC_VERSION")]
+#[stable(feature = "prelude_2024", since = "1.85.0")]
 pub mod rust_2024 {
     #[stable(feature = "rust1", since = "1.0.0")]
     pub use super::common::*;
 
-    #[stable(feature = "prelude_2024", since = "CURRENT_RUSTC_VERSION")]
+    #[stable(feature = "prelude_2024", since = "1.85.0")]
     #[doc(no_inline)]
     pub use core::prelude::rust_2024::*;
 }
diff --git a/library/std/src/process.rs b/library/std/src/process.rs
index 929d2b57afe..e0dd2e14817 100644
--- a/library/std/src/process.rs
+++ b/library/std/src/process.rs
@@ -868,13 +868,17 @@ impl Command {
     ///
     /// # Examples
     ///
+    /// Prevent any inherited `GIT_DIR` variable from changing the target of the `git` command,
+    /// while allowing all other variables, like `GIT_AUTHOR_NAME`.
+    ///
     /// ```no_run
     /// use std::process::Command;
     ///
-    /// Command::new("ls")
-    ///     .env_remove("PATH")
-    ///     .spawn()
-    ///     .expect("ls command failed to start");
+    /// Command::new("git")
+    ///     .arg("commit")
+    ///     .env_remove("GIT_DIR")
+    ///     .spawn()?;
+    /// # std::io::Result::Ok(())
     /// ```
     #[stable(feature = "process", since = "1.0.0")]
     pub fn env_remove<K: AsRef<OsStr>>(&mut self, key: K) -> &mut Command {
@@ -896,13 +900,17 @@ impl Command {
     ///
     /// # Examples
     ///
+    /// The behavior of `sort` is affected by `LANG` and `LC_*` environment variables.
+    /// Clearing the environment makes `sort`'s behavior independent of the parent processes' language.
+    ///
     /// ```no_run
     /// use std::process::Command;
     ///
-    /// Command::new("ls")
+    /// Command::new("sort")
+    ///     .arg("file.txt")
     ///     .env_clear()
-    ///     .spawn()
-    ///     .expect("ls command failed to start");
+    ///     .spawn()?;
+    /// # std::io::Result::Ok(())
     /// ```
     #[stable(feature = "process", since = "1.0.0")]
     pub fn env_clear(&mut self) -> &mut Command {
@@ -1283,13 +1291,13 @@ impl fmt::Debug for Output {
     fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
         let stdout_utf8 = str::from_utf8(&self.stdout);
         let stdout_debug: &dyn fmt::Debug = match stdout_utf8 {
-            Ok(ref str) => str,
+            Ok(ref s) => s,
             Err(_) => &self.stdout,
         };
 
         let stderr_utf8 = str::from_utf8(&self.stderr);
         let stderr_debug: &dyn fmt::Debug = match stderr_utf8 {
-            Ok(ref str) => str,
+            Ok(ref s) => s,
             Err(_) => &self.stderr,
         };
 
diff --git a/library/std/src/sync/poison/mutex.rs b/library/std/src/sync/poison/mutex.rs
index e28c2090afe..01ef71a187f 100644
--- a/library/std/src/sync/poison/mutex.rs
+++ b/library/std/src/sync/poison/mutex.rs
@@ -534,7 +534,7 @@ impl<T: ?Sized> Mutex<T> {
     /// # Errors
     ///
     /// If another user of this mutex panicked while holding the mutex, then
-    /// this call will return an error containing the the underlying data
+    /// this call will return an error containing the underlying data
     /// instead.
     ///
     /// # Examples
diff --git a/library/std/src/sys/pal/solid/fs.rs b/library/std/src/sys/pal/solid/fs.rs
index 04dd10ad806..fa2e470d6b6 100644
--- a/library/std/src/sys/pal/solid/fs.rs
+++ b/library/std/src/sys/pal/solid/fs.rs
@@ -12,15 +12,12 @@ use crate::sys::unsupported;
 pub use crate::sys_common::fs::exists;
 use crate::sys_common::ignore_notfound;
 
+type CIntNotMinusOne = core::num::niche_types::NotAllOnes<c_int>;
+
 /// A file descriptor.
 #[derive(Clone, Copy)]
-#[rustc_layout_scalar_valid_range_start(0)]
-// libstd/os/raw/mod.rs assures me that every libstd-supported platform has a
-// 32-bit c_int. Below is -2, in two's complement, but that only works out
-// because c_int is 32 bits.
-#[rustc_layout_scalar_valid_range_end(0xFF_FF_FF_FE)]
 struct FileDesc {
-    fd: c_int,
+    fd: CIntNotMinusOne,
 }
 
 impl FileDesc {
@@ -29,12 +26,13 @@ impl FileDesc {
         assert_ne!(fd, -1i32);
         // Safety: we just asserted that the value is in the valid range and
         // isn't `-1` (the only value bigger than `0xFF_FF_FF_FE` unsigned)
-        unsafe { FileDesc { fd } }
+        let fd = unsafe { CIntNotMinusOne::new_unchecked(fd) };
+        FileDesc { fd }
     }
 
     #[inline]
     fn raw(&self) -> c_int {
-        self.fd
+        self.fd.as_inner()
     }
 }
 
diff --git a/library/std/src/sys/pal/uefi/fs.rs b/library/std/src/sys/pal/uefi/fs.rs
new file mode 100644
index 00000000000..9585ec24f68
--- /dev/null
+++ b/library/std/src/sys/pal/uefi/fs.rs
@@ -0,0 +1,344 @@
+use crate::ffi::OsString;
+use crate::fmt;
+use crate::hash::{Hash, Hasher};
+use crate::io::{self, BorrowedCursor, IoSlice, IoSliceMut, SeekFrom};
+use crate::path::{Path, PathBuf};
+use crate::sys::time::SystemTime;
+use crate::sys::unsupported;
+
+pub struct File(!);
+
+pub struct FileAttr(!);
+
+pub struct ReadDir(!);
+
+pub struct DirEntry(!);
+
+#[derive(Clone, Debug)]
+pub struct OpenOptions {}
+
+#[derive(Copy, Clone, Debug, Default)]
+pub struct FileTimes {}
+
+pub struct FilePermissions(!);
+
+pub struct FileType(!);
+
+#[derive(Debug)]
+pub struct DirBuilder {}
+
+impl FileAttr {
+    pub fn size(&self) -> u64 {
+        self.0
+    }
+
+    pub fn perm(&self) -> FilePermissions {
+        self.0
+    }
+
+    pub fn file_type(&self) -> FileType {
+        self.0
+    }
+
+    pub fn modified(&self) -> io::Result<SystemTime> {
+        self.0
+    }
+
+    pub fn accessed(&self) -> io::Result<SystemTime> {
+        self.0
+    }
+
+    pub fn created(&self) -> io::Result<SystemTime> {
+        self.0
+    }
+}
+
+impl Clone for FileAttr {
+    fn clone(&self) -> FileAttr {
+        self.0
+    }
+}
+
+impl FilePermissions {
+    pub fn readonly(&self) -> bool {
+        self.0
+    }
+
+    pub fn set_readonly(&mut self, _readonly: bool) {
+        self.0
+    }
+}
+
+impl Clone for FilePermissions {
+    fn clone(&self) -> FilePermissions {
+        self.0
+    }
+}
+
+impl PartialEq for FilePermissions {
+    fn eq(&self, _other: &FilePermissions) -> bool {
+        self.0
+    }
+}
+
+impl Eq for FilePermissions {}
+
+impl fmt::Debug for FilePermissions {
+    fn fmt(&self, _f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        self.0
+    }
+}
+
+impl FileTimes {
+    pub fn set_accessed(&mut self, _t: SystemTime) {}
+    pub fn set_modified(&mut self, _t: SystemTime) {}
+}
+
+impl FileType {
+    pub fn is_dir(&self) -> bool {
+        self.0
+    }
+
+    pub fn is_file(&self) -> bool {
+        self.0
+    }
+
+    pub fn is_symlink(&self) -> bool {
+        self.0
+    }
+}
+
+impl Clone for FileType {
+    fn clone(&self) -> FileType {
+        self.0
+    }
+}
+
+impl Copy for FileType {}
+
+impl PartialEq for FileType {
+    fn eq(&self, _other: &FileType) -> bool {
+        self.0
+    }
+}
+
+impl Eq for FileType {}
+
+impl Hash for FileType {
+    fn hash<H: Hasher>(&self, _h: &mut H) {
+        self.0
+    }
+}
+
+impl fmt::Debug for FileType {
+    fn fmt(&self, _f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        self.0
+    }
+}
+
+impl fmt::Debug for ReadDir {
+    fn fmt(&self, _f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        self.0
+    }
+}
+
+impl Iterator for ReadDir {
+    type Item = io::Result<DirEntry>;
+
+    fn next(&mut self) -> Option<io::Result<DirEntry>> {
+        self.0
+    }
+}
+
+impl DirEntry {
+    pub fn path(&self) -> PathBuf {
+        self.0
+    }
+
+    pub fn file_name(&self) -> OsString {
+        self.0
+    }
+
+    pub fn metadata(&self) -> io::Result<FileAttr> {
+        self.0
+    }
+
+    pub fn file_type(&self) -> io::Result<FileType> {
+        self.0
+    }
+}
+
+impl OpenOptions {
+    pub fn new() -> OpenOptions {
+        OpenOptions {}
+    }
+
+    pub fn read(&mut self, _read: bool) {}
+    pub fn write(&mut self, _write: bool) {}
+    pub fn append(&mut self, _append: bool) {}
+    pub fn truncate(&mut self, _truncate: bool) {}
+    pub fn create(&mut self, _create: bool) {}
+    pub fn create_new(&mut self, _create_new: bool) {}
+}
+
+impl File {
+    pub fn open(_path: &Path, _opts: &OpenOptions) -> io::Result<File> {
+        unsupported()
+    }
+
+    pub fn file_attr(&self) -> io::Result<FileAttr> {
+        self.0
+    }
+
+    pub fn fsync(&self) -> io::Result<()> {
+        self.0
+    }
+
+    pub fn datasync(&self) -> io::Result<()> {
+        self.0
+    }
+
+    pub fn lock(&self) -> io::Result<()> {
+        self.0
+    }
+
+    pub fn lock_shared(&self) -> io::Result<()> {
+        self.0
+    }
+
+    pub fn try_lock(&self) -> io::Result<bool> {
+        self.0
+    }
+
+    pub fn try_lock_shared(&self) -> io::Result<bool> {
+        self.0
+    }
+
+    pub fn unlock(&self) -> io::Result<()> {
+        self.0
+    }
+
+    pub fn truncate(&self, _size: u64) -> io::Result<()> {
+        self.0
+    }
+
+    pub fn read(&self, _buf: &mut [u8]) -> io::Result<usize> {
+        self.0
+    }
+
+    pub fn read_vectored(&self, _bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
+        self.0
+    }
+
+    pub fn is_read_vectored(&self) -> bool {
+        self.0
+    }
+
+    pub fn read_buf(&self, _cursor: BorrowedCursor<'_>) -> io::Result<()> {
+        self.0
+    }
+
+    pub fn write(&self, _buf: &[u8]) -> io::Result<usize> {
+        self.0
+    }
+
+    pub fn write_vectored(&self, _bufs: &[IoSlice<'_>]) -> io::Result<usize> {
+        self.0
+    }
+
+    pub fn is_write_vectored(&self) -> bool {
+        self.0
+    }
+
+    pub fn flush(&self) -> io::Result<()> {
+        self.0
+    }
+
+    pub fn seek(&self, _pos: SeekFrom) -> io::Result<u64> {
+        self.0
+    }
+
+    pub fn duplicate(&self) -> io::Result<File> {
+        self.0
+    }
+
+    pub fn set_permissions(&self, _perm: FilePermissions) -> io::Result<()> {
+        self.0
+    }
+
+    pub fn set_times(&self, _times: FileTimes) -> io::Result<()> {
+        self.0
+    }
+}
+
+impl DirBuilder {
+    pub fn new() -> DirBuilder {
+        DirBuilder {}
+    }
+
+    pub fn mkdir(&self, _p: &Path) -> io::Result<()> {
+        unsupported()
+    }
+}
+
+impl fmt::Debug for File {
+    fn fmt(&self, _f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        self.0
+    }
+}
+
+pub fn readdir(_p: &Path) -> io::Result<ReadDir> {
+    unsupported()
+}
+
+pub fn unlink(_p: &Path) -> io::Result<()> {
+    unsupported()
+}
+
+pub fn rename(_old: &Path, _new: &Path) -> io::Result<()> {
+    unsupported()
+}
+
+pub fn set_perm(_p: &Path, perm: FilePermissions) -> io::Result<()> {
+    match perm.0 {}
+}
+
+pub fn rmdir(_p: &Path) -> io::Result<()> {
+    unsupported()
+}
+
+pub fn remove_dir_all(_path: &Path) -> io::Result<()> {
+    unsupported()
+}
+
+pub fn exists(_path: &Path) -> io::Result<bool> {
+    unsupported()
+}
+
+pub fn readlink(_p: &Path) -> io::Result<PathBuf> {
+    unsupported()
+}
+
+pub fn symlink(_original: &Path, _link: &Path) -> io::Result<()> {
+    unsupported()
+}
+
+pub fn link(_src: &Path, _dst: &Path) -> io::Result<()> {
+    unsupported()
+}
+
+pub fn stat(_p: &Path) -> io::Result<FileAttr> {
+    unsupported()
+}
+
+pub fn lstat(_p: &Path) -> io::Result<FileAttr> {
+    unsupported()
+}
+
+pub fn canonicalize(_p: &Path) -> io::Result<PathBuf> {
+    unsupported()
+}
+
+pub fn copy(_from: &Path, _to: &Path) -> io::Result<u64> {
+    unsupported()
+}
diff --git a/library/std/src/sys/pal/uefi/mod.rs b/library/std/src/sys/pal/uefi/mod.rs
index f29c91f3bfe..111bed7a7eb 100644
--- a/library/std/src/sys/pal/uefi/mod.rs
+++ b/library/std/src/sys/pal/uefi/mod.rs
@@ -15,7 +15,6 @@
 
 pub mod args;
 pub mod env;
-#[path = "../unsupported/fs.rs"]
 pub mod fs;
 pub mod helpers;
 #[path = "../unsupported/io.rs"]
diff --git a/library/std/src/sys/pal/unix/thread.rs b/library/std/src/sys/pal/unix/thread.rs
index e360ba0f6d7..f657f82e6e3 100644
--- a/library/std/src/sys/pal/unix/thread.rs
+++ b/library/std/src/sys/pal/unix/thread.rs
@@ -130,25 +130,27 @@ impl Thread {
         }
     }
 
-    #[cfg(target_os = "linux")]
+    #[cfg(any(target_os = "linux", target_os = "freebsd", target_os = "dragonfly"))]
     pub fn set_name(name: &CStr) {
-        const TASK_COMM_LEN: usize = 16;
-
         unsafe {
-            // Available since glibc 2.12, musl 1.1.16, and uClibc 1.0.20.
-            let name = truncate_cstr::<{ TASK_COMM_LEN }>(name);
+            cfg_if::cfg_if! {
+                if #[cfg(target_os = "linux")] {
+                    // Linux limits the allowed length of the name.
+                    const TASK_COMM_LEN: usize = 16;
+                    let name = truncate_cstr::<{ TASK_COMM_LEN }>(name);
+                } else {
+                    // FreeBSD and DragonFly BSD do not enforce length limits.
+                }
+            };
+            // Available since glibc 2.12, musl 1.1.16, and uClibc 1.0.20 for Linux,
+            // FreeBSD 12.2 and 13.0, and DragonFly BSD 6.0.
             let res = libc::pthread_setname_np(libc::pthread_self(), name.as_ptr());
             // We have no good way of propagating errors here, but in debug-builds let's check that this actually worked.
             debug_assert_eq!(res, 0);
         }
     }
 
-    #[cfg(any(
-        target_os = "freebsd",
-        target_os = "dragonfly",
-        target_os = "openbsd",
-        target_os = "nuttx"
-    ))]
+    #[cfg(any(target_os = "openbsd", target_os = "nuttx"))]
     pub fn set_name(name: &CStr) {
         unsafe {
             libc::pthread_set_name_np(libc::pthread_self(), name.as_ptr());
diff --git a/library/std/src/sys/pal/unix/time.rs b/library/std/src/sys/pal/unix/time.rs
index 343864d0b3f..e224980e95f 100644
--- a/library/std/src/sys/pal/unix/time.rs
+++ b/library/std/src/sys/pal/unix/time.rs
@@ -1,3 +1,5 @@
+use core::num::niche_types::Nanoseconds;
+
 use crate::time::Duration;
 use crate::{fmt, io};
 
@@ -16,12 +18,6 @@ pub(in crate::sys) const TIMESPEC_MAX_CAPPED: libc::timespec = libc::timespec {
 };
 
 #[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
-#[repr(transparent)]
-#[rustc_layout_scalar_valid_range_start(0)]
-#[rustc_layout_scalar_valid_range_end(999_999_999)]
-struct Nanoseconds(u32);
-
-#[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
 pub struct SystemTime {
     pub(crate) t: Timespec,
 }
@@ -59,14 +55,14 @@ impl fmt::Debug for SystemTime {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         f.debug_struct("SystemTime")
             .field("tv_sec", &self.t.tv_sec)
-            .field("tv_nsec", &self.t.tv_nsec.0)
+            .field("tv_nsec", &self.t.tv_nsec)
             .finish()
     }
 }
 
 impl Timespec {
     const unsafe fn new_unchecked(tv_sec: i64, tv_nsec: i64) -> Timespec {
-        Timespec { tv_sec, tv_nsec: unsafe { Nanoseconds(tv_nsec as u32) } }
+        Timespec { tv_sec, tv_nsec: unsafe { Nanoseconds::new_unchecked(tv_nsec as u32) } }
     }
 
     pub const fn zero() -> Timespec {
@@ -147,12 +143,15 @@ impl Timespec {
             //
             // Ideally this code could be rearranged such that it more
             // directly expresses the lower-cost behavior we want from it.
-            let (secs, nsec) = if self.tv_nsec.0 >= other.tv_nsec.0 {
-                ((self.tv_sec - other.tv_sec) as u64, self.tv_nsec.0 - other.tv_nsec.0)
+            let (secs, nsec) = if self.tv_nsec.as_inner() >= other.tv_nsec.as_inner() {
+                (
+                    (self.tv_sec - other.tv_sec) as u64,
+                    self.tv_nsec.as_inner() - other.tv_nsec.as_inner(),
+                )
             } else {
                 (
                     (self.tv_sec - other.tv_sec - 1) as u64,
-                    self.tv_nsec.0 + (NSEC_PER_SEC as u32) - other.tv_nsec.0,
+                    self.tv_nsec.as_inner() + (NSEC_PER_SEC as u32) - other.tv_nsec.as_inner(),
                 )
             };
 
@@ -170,7 +169,7 @@ impl Timespec {
 
         // Nano calculations can't overflow because nanos are <1B which fit
         // in a u32.
-        let mut nsec = other.subsec_nanos() + self.tv_nsec.0;
+        let mut nsec = other.subsec_nanos() + self.tv_nsec.as_inner();
         if nsec >= NSEC_PER_SEC as u32 {
             nsec -= NSEC_PER_SEC as u32;
             secs = secs.checked_add(1)?;
@@ -182,7 +181,7 @@ impl Timespec {
         let mut secs = self.tv_sec.checked_sub_unsigned(other.as_secs())?;
 
         // Similar to above, nanos can't overflow.
-        let mut nsec = self.tv_nsec.0 as i32 - other.subsec_nanos() as i32;
+        let mut nsec = self.tv_nsec.as_inner() as i32 - other.subsec_nanos() as i32;
         if nsec < 0 {
             nsec += NSEC_PER_SEC as i32;
             secs = secs.checked_sub(1)?;
@@ -194,7 +193,7 @@ impl Timespec {
     pub fn to_timespec(&self) -> Option<libc::timespec> {
         Some(libc::timespec {
             tv_sec: self.tv_sec.try_into().ok()?,
-            tv_nsec: self.tv_nsec.0.try_into().ok()?,
+            tv_nsec: self.tv_nsec.as_inner().try_into().ok()?,
         })
     }
 
@@ -203,7 +202,7 @@ impl Timespec {
     #[cfg(target_os = "nto")]
     pub(in crate::sys) fn to_timespec_capped(&self) -> Option<libc::timespec> {
         // Check if timeout in nanoseconds would fit into an u64
-        if (self.tv_nsec.0 as u64)
+        if (self.tv_nsec.as_inner() as u64)
             .checked_add((self.tv_sec as u64).checked_mul(NSEC_PER_SEC)?)
             .is_none()
         {
@@ -219,7 +218,7 @@ impl Timespec {
         not(target_arch = "riscv32")
     ))]
     pub fn to_timespec64(&self) -> __timespec64 {
-        __timespec64::new(self.tv_sec, self.tv_nsec.0 as _)
+        __timespec64::new(self.tv_sec, self.tv_nsec.as_inner() as _)
     }
 }
 
@@ -293,7 +292,7 @@ impl fmt::Debug for Instant {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         f.debug_struct("Instant")
             .field("tv_sec", &self.t.tv_sec)
-            .field("tv_nsec", &self.t.tv_nsec.0)
+            .field("tv_nsec", &self.t.tv_nsec)
             .finish()
     }
 }
diff --git a/library/std/src/sys/pal/windows/mod.rs b/library/std/src/sys/pal/windows/mod.rs
index 88e6def7a75..4282dbb5493 100644
--- a/library/std/src/sys/pal/windows/mod.rs
+++ b/library/std/src/sys/pal/windows/mod.rs
@@ -272,7 +272,7 @@ where
                 unreachable!();
             } else {
                 // Safety: First `k` values are initialized.
-                let slice: &[u16] = MaybeUninit::slice_assume_init_ref(&buf[..k]);
+                let slice: &[u16] = buf[..k].assume_init_ref();
                 return Ok(f2(slice));
             }
         }
diff --git a/library/std/src/sys/pal/windows/process.rs b/library/std/src/sys/pal/windows/process.rs
index 2ca20a21dfe..9332c9b49ff 100644
--- a/library/std/src/sys/pal/windows/process.rs
+++ b/library/std/src/sys/pal/windows/process.rs
@@ -142,11 +142,11 @@ impl AsRef<OsStr> for EnvKey {
     }
 }
 
-pub(crate) fn ensure_no_nuls<T: AsRef<OsStr>>(str: T) -> io::Result<T> {
-    if str.as_ref().encode_wide().any(|b| b == 0) {
+pub(crate) fn ensure_no_nuls<T: AsRef<OsStr>>(s: T) -> io::Result<T> {
+    if s.as_ref().encode_wide().any(|b| b == 0) {
         Err(io::const_error!(ErrorKind::InvalidInput, "nul byte found in provided data"))
     } else {
-        Ok(str)
+        Ok(s)
     }
 }
 
diff --git a/library/std/src/sys/pal/windows/stdio.rs b/library/std/src/sys/pal/windows/stdio.rs
index 1b735e7f0cb..fd3f559ba19 100644
--- a/library/std/src/sys/pal/windows/stdio.rs
+++ b/library/std/src/sys/pal/windows/stdio.rs
@@ -207,7 +207,7 @@ fn write_valid_utf8_to_console(handle: c::HANDLE, utf8: &str) -> io::Result<usiz
         assert!(result != 0, "Unexpected error in MultiByteToWideChar");
 
         // Safety: MultiByteToWideChar initializes `result` values.
-        MaybeUninit::slice_assume_init_ref(&utf16[..result as usize])
+        utf16[..result as usize].assume_init_ref()
     };
 
     let mut written = write_u16s(handle, utf16)?;
@@ -283,7 +283,7 @@ impl io::Read for Stdin {
             let read = read_u16s_fixup_surrogates(handle, &mut utf16_buf, 1, &mut self.surrogate)?;
             // Read bytes, using the (now-empty) self.incomplete_utf8 as extra space.
             let read_bytes = utf16_to_utf8(
-                unsafe { MaybeUninit::slice_assume_init_ref(&utf16_buf[..read]) },
+                unsafe { utf16_buf[..read].assume_init_ref() },
                 &mut self.incomplete_utf8.bytes,
             )?;
 
@@ -303,7 +303,7 @@ impl io::Read for Stdin {
                 read_u16s_fixup_surrogates(handle, &mut utf16_buf, amount, &mut self.surrogate)?;
             // Safety `read_u16s_fixup_surrogates` returns the number of items
             // initialized.
-            let utf16s = unsafe { MaybeUninit::slice_assume_init_ref(&utf16_buf[..read]) };
+            let utf16s = unsafe { utf16_buf[..read].assume_init_ref() };
             match utf16_to_utf8(utf16s, buf) {
                 Ok(value) => return Ok(bytes_copied + value),
                 Err(e) => return Err(e),
diff --git a/library/std/src/sys/sync/condvar/no_threads.rs b/library/std/src/sys/sync/condvar/no_threads.rs
index 88ce39305e1..18d97d4b17a 100644
--- a/library/std/src/sys/sync/condvar/no_threads.rs
+++ b/library/std/src/sys/sync/condvar/no_threads.rs
@@ -1,4 +1,5 @@
 use crate::sys::sync::Mutex;
+use crate::thread::sleep;
 use crate::time::Duration;
 
 pub struct Condvar {}
@@ -19,7 +20,8 @@ impl Condvar {
         panic!("condvar wait not supported")
     }
 
-    pub unsafe fn wait_timeout(&self, _mutex: &Mutex, _dur: Duration) -> bool {
-        panic!("condvar wait not supported");
+    pub unsafe fn wait_timeout(&self, _mutex: &Mutex, dur: Duration) -> bool {
+        sleep(dur);
+        false
     }
 }
diff --git a/library/std/src/sys_common/wtf8.rs b/library/std/src/sys_common/wtf8.rs
index 666942bb8a1..6c60d901ee9 100644
--- a/library/std/src/sys_common/wtf8.rs
+++ b/library/std/src/sys_common/wtf8.rs
@@ -204,8 +204,8 @@ impl Wtf8Buf {
     ///
     /// Since WTF-8 is a superset of UTF-8, this always succeeds.
     #[inline]
-    pub fn from_str(str: &str) -> Wtf8Buf {
-        Wtf8Buf { bytes: <[_]>::to_vec(str.as_bytes()), is_known_utf8: true }
+    pub fn from_str(s: &str) -> Wtf8Buf {
+        Wtf8Buf { bytes: <[_]>::to_vec(s.as_bytes()), is_known_utf8: true }
     }
 
     pub fn clear(&mut self) {
diff --git a/library/std/src/thread/mod.rs b/library/std/src/thread/mod.rs
index 85ee369ca2b..b6ee00a253a 100644
--- a/library/std/src/thread/mod.rs
+++ b/library/std/src/thread/mod.rs
@@ -502,7 +502,7 @@ impl Builder {
 
         let id = ThreadId::new();
         let my_thread = match name {
-            Some(name) => Thread::new(id, name.into()),
+            Some(name) => Thread::new(id, name),
             None => Thread::new_unnamed(id),
         };