Adding upstream version 1.64.0+dfsg1.upstream/1.64.0+dfsg1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

3 files changed, 675 insertions, 0 deletions

diff --git a/library/core/src/panic/location.rs b/library/core/src/panic/location.rs
new file mode 100644
index 000000000..8eefd9ff2
--- /dev/null
+++ b/library/core/src/panic/location.rs
@@ -0,0 +1,197 @@
+use crate::fmt;
+
+/// A struct containing information about the location of a panic.
+///
+/// This structure is created by [`PanicInfo::location()`].
+///
+/// [`PanicInfo::location()`]: crate::panic::PanicInfo::location
+///
+/// # Examples
+///
+/// ```should_panic
+/// use std::panic;
+///
+/// panic::set_hook(Box::new(|panic_info| {
+///     if let Some(location) = panic_info.location() {
+///         println!("panic occurred in file '{}' at line {}", location.file(), location.line());
+///     } else {
+///         println!("panic occurred but can't get location information...");
+///     }
+/// }));
+///
+/// panic!("Normal panic");
+/// ```
+///
+/// # Comparisons
+///
+/// Comparisons for equality and ordering are made in file, line, then column priority.
+/// Files are compared as strings, not `Path`, which could be unexpected.
+/// See [`Location::file`]'s documentation for more discussion.
+#[lang = "panic_location"]
+#[derive(Copy, Clone, Debug, Eq, Hash, Ord, PartialEq, PartialOrd)]
+#[stable(feature = "panic_hooks", since = "1.10.0")]
+pub struct Location<'a> {
+    file: &'a str,
+    line: u32,
+    col: u32,
+}
+
+impl<'a> Location<'a> {
+    /// Returns the source location of the caller of this function. If that function's caller is
+    /// annotated then its call location will be returned, and so on up the stack to the first call
+    /// within a non-tracked function body.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use std::panic::Location;
+    ///
+    /// /// Returns the [`Location`] at which it is called.
+    /// #[track_caller]
+    /// fn get_caller_location() -> &'static Location<'static> {
+    ///     Location::caller()
+    /// }
+    ///
+    /// /// Returns a [`Location`] from within this function's definition.
+    /// fn get_just_one_location() -> &'static Location<'static> {
+    ///     get_caller_location()
+    /// }
+    ///
+    /// let fixed_location = get_just_one_location();
+    /// assert_eq!(fixed_location.file(), file!());
+    /// assert_eq!(fixed_location.line(), 14);
+    /// assert_eq!(fixed_location.column(), 5);
+    ///
+    /// // running the same untracked function in a different location gives us the same result
+    /// let second_fixed_location = get_just_one_location();
+    /// assert_eq!(fixed_location.file(), second_fixed_location.file());
+    /// assert_eq!(fixed_location.line(), second_fixed_location.line());
+    /// assert_eq!(fixed_location.column(), second_fixed_location.column());
+    ///
+    /// let this_location = get_caller_location();
+    /// assert_eq!(this_location.file(), file!());
+    /// assert_eq!(this_location.line(), 28);
+    /// assert_eq!(this_location.column(), 21);
+    ///
+    /// // running the tracked function in a different location produces a different value
+    /// let another_location = get_caller_location();
+    /// assert_eq!(this_location.file(), another_location.file());
+    /// assert_ne!(this_location.line(), another_location.line());
+    /// assert_ne!(this_location.column(), another_location.column());
+    /// ```
+    #[must_use]
+    #[stable(feature = "track_caller", since = "1.46.0")]
+    #[rustc_const_unstable(feature = "const_caller_location", issue = "76156")]
+    #[track_caller]
+    #[inline]
+    pub const fn caller() -> &'static Location<'static> {
+        crate::intrinsics::caller_location()
+    }
+
+    /// Returns the name of the source file from which the panic originated.
+    ///
+    /// # `&str`, not `&Path`
+    ///
+    /// The returned name refers to a source path on the compiling system, but it isn't valid to
+    /// represent this directly as a `&Path`. The compiled code may run on a different system with
+    /// a different `Path` implementation than the system providing the contents and this library
+    /// does not currently have a different "host path" type.
+    ///
+    /// The most surprising behavior occurs when "the same" file is reachable via multiple paths in
+    /// the module system (usually using the `#[path = "..."]` attribute or similar), which can
+    /// cause what appears to be identical code to return differing values from this function.
+    ///
+    /// # Cross-compilation
+    ///
+    /// This value is not suitable for passing to `Path::new` or similar constructors when the host
+    /// platform and target platform differ.
+    ///
+    /// # Examples
+    ///
+    /// ```should_panic
+    /// use std::panic;
+    ///
+    /// panic::set_hook(Box::new(|panic_info| {
+    ///     if let Some(location) = panic_info.location() {
+    ///         println!("panic occurred in file '{}'", location.file());
+    ///     } else {
+    ///         println!("panic occurred but can't get location information...");
+    ///     }
+    /// }));
+    ///
+    /// panic!("Normal panic");
+    /// ```
+    #[must_use]
+    #[stable(feature = "panic_hooks", since = "1.10.0")]
+    #[inline]
+    pub fn file(&self) -> &str {
+        self.file
+    }
+
+    /// Returns the line number from which the panic originated.
+    ///
+    /// # Examples
+    ///
+    /// ```should_panic
+    /// use std::panic;
+    ///
+    /// panic::set_hook(Box::new(|panic_info| {
+    ///     if let Some(location) = panic_info.location() {
+    ///         println!("panic occurred at line {}", location.line());
+    ///     } else {
+    ///         println!("panic occurred but can't get location information...");
+    ///     }
+    /// }));
+    ///
+    /// panic!("Normal panic");
+    /// ```
+    #[must_use]
+    #[stable(feature = "panic_hooks", since = "1.10.0")]
+    #[inline]
+    pub fn line(&self) -> u32 {
+        self.line
+    }
+
+    /// Returns the column from which the panic originated.
+    ///
+    /// # Examples
+    ///
+    /// ```should_panic
+    /// use std::panic;
+    ///
+    /// panic::set_hook(Box::new(|panic_info| {
+    ///     if let Some(location) = panic_info.location() {
+    ///         println!("panic occurred at column {}", location.column());
+    ///     } else {
+    ///         println!("panic occurred but can't get location information...");
+    ///     }
+    /// }));
+    ///
+    /// panic!("Normal panic");
+    /// ```
+    #[must_use]
+    #[stable(feature = "panic_col", since = "1.25.0")]
+    #[inline]
+    pub fn column(&self) -> u32 {
+        self.col
+    }
+}
+
+#[unstable(
+    feature = "panic_internals",
+    reason = "internal details of the implementation of the `panic!` and related macros",
+    issue = "none"
+)]
+impl<'a> Location<'a> {
+    #[doc(hidden)]
+    pub const fn internal_constructor(file: &'a str, line: u32, col: u32) -> Self {
+        Location { file, line, col }
+    }
+}
+
+#[stable(feature = "panic_hook_display", since = "1.26.0")]
+impl fmt::Display for Location<'_> {
+    fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(formatter, "{}:{}:{}", self.file, self.line, self.col)
+    }
+}
diff --git a/library/core/src/panic/panic_info.rs b/library/core/src/panic/panic_info.rs
new file mode 100644
index 000000000..1923155eb
--- /dev/null
+++ b/library/core/src/panic/panic_info.rs
@@ -0,0 +1,166 @@
+use crate::any::Any;
+use crate::fmt;
+use crate::panic::Location;
+
+/// A struct providing information about a panic.
+///
+/// `PanicInfo` structure is passed to a panic hook set by the [`set_hook`]
+/// function.
+///
+/// [`set_hook`]: ../../std/panic/fn.set_hook.html
+///
+/// # Examples
+///
+/// ```should_panic
+/// use std::panic;
+///
+/// panic::set_hook(Box::new(|panic_info| {
+///     if let Some(s) = panic_info.payload().downcast_ref::<&str>() {
+///         println!("panic occurred: {s:?}");
+///     } else {
+///         println!("panic occurred");
+///     }
+/// }));
+///
+/// panic!("Normal panic");
+/// ```
+#[lang = "panic_info"]
+#[stable(feature = "panic_hooks", since = "1.10.0")]
+#[derive(Debug)]
+pub struct PanicInfo<'a> {
+    payload: &'a (dyn Any + Send),
+    message: Option<&'a fmt::Arguments<'a>>,
+    location: &'a Location<'a>,
+    can_unwind: bool,
+}
+
+impl<'a> PanicInfo<'a> {
+    #[unstable(
+        feature = "panic_internals",
+        reason = "internal details of the implementation of the `panic!` and related macros",
+        issue = "none"
+    )]
+    #[doc(hidden)]
+    #[inline]
+    pub fn internal_constructor(
+        message: Option<&'a fmt::Arguments<'a>>,
+        location: &'a Location<'a>,
+        can_unwind: bool,
+    ) -> Self {
+        struct NoPayload;
+        PanicInfo { location, message, payload: &NoPayload, can_unwind }
+    }
+
+    #[unstable(
+        feature = "panic_internals",
+        reason = "internal details of the implementation of the `panic!` and related macros",
+        issue = "none"
+    )]
+    #[doc(hidden)]
+    #[inline]
+    pub fn set_payload(&mut self, info: &'a (dyn Any + Send)) {
+        self.payload = info;
+    }
+
+    /// Returns the payload associated with the panic.
+    ///
+    /// This will commonly, but not always, be a `&'static str` or [`String`].
+    ///
+    /// [`String`]: ../../std/string/struct.String.html
+    ///
+    /// # Examples
+    ///
+    /// ```should_panic
+    /// use std::panic;
+    ///
+    /// panic::set_hook(Box::new(|panic_info| {
+    ///     if let Some(s) = panic_info.payload().downcast_ref::<&str>() {
+    ///         println!("panic occurred: {s:?}");
+    ///     } else {
+    ///         println!("panic occurred");
+    ///     }
+    /// }));
+    ///
+    /// panic!("Normal panic");
+    /// ```
+    #[must_use]
+    #[stable(feature = "panic_hooks", since = "1.10.0")]
+    pub fn payload(&self) -> &(dyn Any + Send) {
+        self.payload
+    }
+
+    /// If the `panic!` macro from the `core` crate (not from `std`)
+    /// was used with a formatting string and some additional arguments,
+    /// returns that message ready to be used for example with [`fmt::write`]
+    #[must_use]
+    #[unstable(feature = "panic_info_message", issue = "66745")]
+    pub fn message(&self) -> Option<&fmt::Arguments<'_>> {
+        self.message
+    }
+
+    /// Returns information about the location from which the panic originated,
+    /// if available.
+    ///
+    /// This method will currently always return [`Some`], but this may change
+    /// in future versions.
+    ///
+    /// # Examples
+    ///
+    /// ```should_panic
+    /// use std::panic;
+    ///
+    /// panic::set_hook(Box::new(|panic_info| {
+    ///     if let Some(location) = panic_info.location() {
+    ///         println!("panic occurred in file '{}' at line {}",
+    ///             location.file(),
+    ///             location.line(),
+    ///         );
+    ///     } else {
+    ///         println!("panic occurred but can't get location information...");
+    ///     }
+    /// }));
+    ///
+    /// panic!("Normal panic");
+    /// ```
+    #[must_use]
+    #[stable(feature = "panic_hooks", since = "1.10.0")]
+    pub fn location(&self) -> Option<&Location<'_>> {
+        // NOTE: If this is changed to sometimes return None,
+        // deal with that case in std::panicking::default_hook and core::panicking::panic_fmt.
+        Some(&self.location)
+    }
+
+    /// Returns whether the panic handler is allowed to unwind the stack from
+    /// the point where the panic occurred.
+    ///
+    /// This is true for most kinds of panics with the exception of panics
+    /// caused by trying to unwind out of a `Drop` implementation or a function
+    /// whose ABI does not support unwinding.
+    ///
+    /// It is safe for a panic handler to unwind even when this function returns
+    /// true, however this will simply cause the panic handler to be called
+    /// again.
+    #[must_use]
+    #[unstable(feature = "panic_can_unwind", issue = "92988")]
+    pub fn can_unwind(&self) -> bool {
+        self.can_unwind
+    }
+}
+
+#[stable(feature = "panic_hook_display", since = "1.26.0")]
+impl fmt::Display for PanicInfo<'_> {
+    fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
+        formatter.write_str("panicked at ")?;
+        if let Some(message) = self.message {
+            write!(formatter, "'{}', ", message)?
+        } else if let Some(payload) = self.payload.downcast_ref::<&'static str>() {
+            write!(formatter, "'{}', ", payload)?
+        }
+        // NOTE: we cannot use downcast_ref::<String>() here
+        // since String is not available in libcore!
+        // The payload is a String when `std::panic!` is called with multiple arguments,
+        // but in that case the message is also available.
+
+        self.location.fmt(formatter)
+    }
+}
diff --git a/library/core/src/panic/unwind_safe.rs b/library/core/src/panic/unwind_safe.rs
new file mode 100644
index 000000000..9a6153f12
--- /dev/null
+++ b/library/core/src/panic/unwind_safe.rs
@@ -0,0 +1,312 @@
+use crate::async_iter::AsyncIterator;
+use crate::cell::UnsafeCell;
+use crate::fmt;
+use crate::future::Future;
+use crate::ops::{Deref, DerefMut};
+use crate::pin::Pin;
+use crate::ptr::{NonNull, Unique};
+use crate::task::{Context, Poll};
+
+/// A marker trait which represents "panic safe" types in Rust.
+///
+/// This trait is implemented by default for many types and behaves similarly in
+/// terms of inference of implementation to the [`Send`] and [`Sync`] traits. The
+/// purpose of this trait is to encode what types are safe to cross a [`catch_unwind`]
+/// boundary with no fear of unwind safety.
+///
+/// [`catch_unwind`]: ../../std/panic/fn.catch_unwind.html
+///
+/// ## What is unwind safety?
+///
+/// In Rust a function can "return" early if it either panics or calls a
+/// function which transitively panics. This sort of control flow is not always
+/// anticipated, and has the possibility of causing subtle bugs through a
+/// combination of two critical components:
+///
+/// 1. A data structure is in a temporarily invalid state when the thread
+///    panics.
+/// 2. This broken invariant is then later observed.
+///
+/// Typically in Rust, it is difficult to perform step (2) because catching a
+/// panic involves either spawning a thread (which in turns makes it difficult
+/// to later witness broken invariants) or using the `catch_unwind` function in this
+/// module. Additionally, even if an invariant is witnessed, it typically isn't a
+/// problem in Rust because there are no uninitialized values (like in C or C++).
+///
+/// It is possible, however, for **logical** invariants to be broken in Rust,
+/// which can end up causing behavioral bugs. Another key aspect of unwind safety
+/// in Rust is that, in the absence of `unsafe` code, a panic cannot lead to
+/// memory unsafety.
+///
+/// That was a bit of a whirlwind tour of unwind safety, but for more information
+/// about unwind safety and how it applies to Rust, see an [associated RFC][rfc].
+///
+/// [rfc]: https://github.com/rust-lang/rfcs/blob/master/text/1236-stabilize-catch-panic.md
+///
+/// ## What is `UnwindSafe`?
+///
+/// Now that we've got an idea of what unwind safety is in Rust, it's also
+/// important to understand what this trait represents. As mentioned above, one
+/// way to witness broken invariants is through the `catch_unwind` function in this
+/// module as it allows catching a panic and then re-using the environment of
+/// the closure.
+///
+/// Simply put, a type `T` implements `UnwindSafe` if it cannot easily allow
+/// witnessing a broken invariant through the use of `catch_unwind` (catching a
+/// panic). This trait is an auto trait, so it is automatically implemented for
+/// many types, and it is also structurally composed (e.g., a struct is unwind
+/// safe if all of its components are unwind safe).
+///
+/// Note, however, that this is not an unsafe trait, so there is not a succinct
+/// contract that this trait is providing. Instead it is intended as more of a
+/// "speed bump" to alert users of `catch_unwind` that broken invariants may be
+/// witnessed and may need to be accounted for.
+///
+/// ## Who implements `UnwindSafe`?
+///
+/// Types such as `&mut T` and `&RefCell<T>` are examples which are **not**
+/// unwind safe. The general idea is that any mutable state which can be shared
+/// across `catch_unwind` is not unwind safe by default. This is because it is very
+/// easy to witness a broken invariant outside of `catch_unwind` as the data is
+/// simply accessed as usual.
+///
+/// Types like `&Mutex<T>`, however, are unwind safe because they implement
+/// poisoning by default. They still allow witnessing a broken invariant, but
+/// they already provide their own "speed bumps" to do so.
+///
+/// ## When should `UnwindSafe` be used?
+///
+/// It is not intended that most types or functions need to worry about this trait.
+/// It is only used as a bound on the `catch_unwind` function and as mentioned
+/// above, the lack of `unsafe` means it is mostly an advisory. The
+/// [`AssertUnwindSafe`] wrapper struct can be used to force this trait to be
+/// implemented for any closed over variables passed to `catch_unwind`.
+#[stable(feature = "catch_unwind", since = "1.9.0")]
+#[cfg_attr(not(test), rustc_diagnostic_item = "unwind_safe_trait")]
+#[rustc_on_unimplemented(
+    message = "the type `{Self}` may not be safely transferred across an unwind boundary",
+    label = "`{Self}` may not be safely transferred across an unwind boundary"
+)]
+pub auto trait UnwindSafe {}
+
+/// A marker trait representing types where a shared reference is considered
+/// unwind safe.
+///
+/// This trait is namely not implemented by [`UnsafeCell`], the root of all
+/// interior mutability.
+///
+/// This is a "helper marker trait" used to provide impl blocks for the
+/// [`UnwindSafe`] trait, for more information see that documentation.
+#[stable(feature = "catch_unwind", since = "1.9.0")]
+#[cfg_attr(not(test), rustc_diagnostic_item = "ref_unwind_safe_trait")]
+#[rustc_on_unimplemented(
+    message = "the type `{Self}` may contain interior mutability and a reference may not be safely \
+               transferrable across a catch_unwind boundary",
+    label = "`{Self}` may contain interior mutability and a reference may not be safely \
+             transferrable across a catch_unwind boundary"
+)]
+pub auto trait RefUnwindSafe {}
+
+/// A simple wrapper around a type to assert that it is unwind safe.
+///
+/// When using [`catch_unwind`] it may be the case that some of the closed over
+/// variables are not unwind safe. For example if `&mut T` is captured the
+/// compiler will generate a warning indicating that it is not unwind safe. It
+/// might not be the case, however, that this is actually a problem due to the
+/// specific usage of [`catch_unwind`] if unwind safety is specifically taken into
+/// account. This wrapper struct is useful for a quick and lightweight
+/// annotation that a variable is indeed unwind safe.
+///
+/// [`catch_unwind`]: ../../std/panic/fn.catch_unwind.html
+///
+/// # Examples
+///
+/// One way to use `AssertUnwindSafe` is to assert that the entire closure
+/// itself is unwind safe, bypassing all checks for all variables:
+///
+/// ```
+/// use std::panic::{self, AssertUnwindSafe};
+///
+/// let mut variable = 4;
+///
+/// // This code will not compile because the closure captures `&mut variable`
+/// // which is not considered unwind safe by default.
+///
+/// // panic::catch_unwind(|| {
+/// //     variable += 3;
+/// // });
+///
+/// // This, however, will compile due to the `AssertUnwindSafe` wrapper
+/// let result = panic::catch_unwind(AssertUnwindSafe(|| {
+///     variable += 3;
+/// }));
+/// // ...
+/// ```
+///
+/// Wrapping the entire closure amounts to a blanket assertion that all captured
+/// variables are unwind safe. This has the downside that if new captures are
+/// added in the future, they will also be considered unwind safe. Therefore,
+/// you may prefer to just wrap individual captures, as shown below. This is
+/// more annotation, but it ensures that if a new capture is added which is not
+/// unwind safe, you will get a compilation error at that time, which will
+/// allow you to consider whether that new capture in fact represent a bug or
+/// not.
+///
+/// ```
+/// use std::panic::{self, AssertUnwindSafe};
+///
+/// let mut variable = 4;
+/// let other_capture = 3;
+///
+/// let result = {
+///     let mut wrapper = AssertUnwindSafe(&mut variable);
+///     panic::catch_unwind(move || {
+///         **wrapper += other_capture;
+///     })
+/// };
+/// // ...
+/// ```
+#[stable(feature = "catch_unwind", since = "1.9.0")]
+pub struct AssertUnwindSafe<T>(#[stable(feature = "catch_unwind", since = "1.9.0")] pub T);
+
+// Implementations of the `UnwindSafe` trait:
+//
+// * By default everything is unwind safe
+// * pointers T contains mutability of some form are not unwind safe
+// * Unique, an owning pointer, lifts an implementation
+// * Types like Mutex/RwLock which are explicitly poisoned are unwind safe
+// * Our custom AssertUnwindSafe wrapper is indeed unwind safe
+
+#[stable(feature = "catch_unwind", since = "1.9.0")]
+impl<T: ?Sized> !UnwindSafe for &mut T {}
+#[stable(feature = "catch_unwind", since = "1.9.0")]
+impl<T: RefUnwindSafe + ?Sized> UnwindSafe for &T {}
+#[stable(feature = "catch_unwind", since = "1.9.0")]
+impl<T: RefUnwindSafe + ?Sized> UnwindSafe for *const T {}
+#[stable(feature = "catch_unwind", since = "1.9.0")]
+impl<T: RefUnwindSafe + ?Sized> UnwindSafe for *mut T {}
+#[unstable(feature = "ptr_internals", issue = "none")]
+impl<T: UnwindSafe + ?Sized> UnwindSafe for Unique<T> {}
+#[stable(feature = "nonnull", since = "1.25.0")]
+impl<T: RefUnwindSafe + ?Sized> UnwindSafe for NonNull<T> {}
+#[stable(feature = "catch_unwind", since = "1.9.0")]
+impl<T> UnwindSafe for AssertUnwindSafe<T> {}
+
+// Pretty simple implementations for the `RefUnwindSafe` marker trait,
+// basically just saying that `UnsafeCell` is the
+// only thing which doesn't implement it (which then transitively applies to
+// everything else).
+#[stable(feature = "catch_unwind", since = "1.9.0")]
+impl<T: ?Sized> !RefUnwindSafe for UnsafeCell<T> {}
+#[stable(feature = "catch_unwind", since = "1.9.0")]
+impl<T> RefUnwindSafe for AssertUnwindSafe<T> {}
+
+#[cfg(target_has_atomic_load_store = "ptr")]
+#[stable(feature = "unwind_safe_atomic_refs", since = "1.14.0")]
+impl RefUnwindSafe for crate::sync::atomic::AtomicIsize {}
+#[cfg(target_has_atomic_load_store = "8")]
+#[stable(feature = "integer_atomics_stable", since = "1.34.0")]
+impl RefUnwindSafe for crate::sync::atomic::AtomicI8 {}
+#[cfg(target_has_atomic_load_store = "16")]
+#[stable(feature = "integer_atomics_stable", since = "1.34.0")]
+impl RefUnwindSafe for crate::sync::atomic::AtomicI16 {}
+#[cfg(target_has_atomic_load_store = "32")]
+#[stable(feature = "integer_atomics_stable", since = "1.34.0")]
+impl RefUnwindSafe for crate::sync::atomic::AtomicI32 {}
+#[cfg(target_has_atomic_load_store = "64")]
+#[stable(feature = "integer_atomics_stable", since = "1.34.0")]
+impl RefUnwindSafe for crate::sync::atomic::AtomicI64 {}
+#[cfg(target_has_atomic_load_store = "128")]
+#[unstable(feature = "integer_atomics", issue = "99069")]
+impl RefUnwindSafe for crate::sync::atomic::AtomicI128 {}
+
+#[cfg(target_has_atomic_load_store = "ptr")]
+#[stable(feature = "unwind_safe_atomic_refs", since = "1.14.0")]
+impl RefUnwindSafe for crate::sync::atomic::AtomicUsize {}
+#[cfg(target_has_atomic_load_store = "8")]
+#[stable(feature = "integer_atomics_stable", since = "1.34.0")]
+impl RefUnwindSafe for crate::sync::atomic::AtomicU8 {}
+#[cfg(target_has_atomic_load_store = "16")]
+#[stable(feature = "integer_atomics_stable", since = "1.34.0")]
+impl RefUnwindSafe for crate::sync::atomic::AtomicU16 {}
+#[cfg(target_has_atomic_load_store = "32")]
+#[stable(feature = "integer_atomics_stable", since = "1.34.0")]
+impl RefUnwindSafe for crate::sync::atomic::AtomicU32 {}
+#[cfg(target_has_atomic_load_store = "64")]
+#[stable(feature = "integer_atomics_stable", since = "1.34.0")]
+impl RefUnwindSafe for crate::sync::atomic::AtomicU64 {}
+#[cfg(target_has_atomic_load_store = "128")]
+#[unstable(feature = "integer_atomics", issue = "99069")]
+impl RefUnwindSafe for crate::sync::atomic::AtomicU128 {}
+
+#[cfg(target_has_atomic_load_store = "8")]
+#[stable(feature = "unwind_safe_atomic_refs", since = "1.14.0")]
+impl RefUnwindSafe for crate::sync::atomic::AtomicBool {}
+
+#[cfg(target_has_atomic_load_store = "ptr")]
+#[stable(feature = "unwind_safe_atomic_refs", since = "1.14.0")]
+impl<T> RefUnwindSafe for crate::sync::atomic::AtomicPtr<T> {}
+
+#[stable(feature = "catch_unwind", since = "1.9.0")]
+impl<T> Deref for AssertUnwindSafe<T> {
+    type Target = T;
+
+    fn deref(&self) -> &T {
+        &self.0
+    }
+}
+
+#[stable(feature = "catch_unwind", since = "1.9.0")]
+impl<T> DerefMut for AssertUnwindSafe<T> {
+    fn deref_mut(&mut self) -> &mut T {
+        &mut self.0
+    }
+}
+
+#[stable(feature = "catch_unwind", since = "1.9.0")]
+impl<R, F: FnOnce() -> R> FnOnce<()> for AssertUnwindSafe<F> {
+    type Output = R;
+
+    extern "rust-call" fn call_once(self, _args: ()) -> R {
+        (self.0)()
+    }
+}
+
+#[stable(feature = "std_debug", since = "1.16.0")]
+impl<T: fmt::Debug> fmt::Debug for AssertUnwindSafe<T> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_tuple("AssertUnwindSafe").field(&self.0).finish()
+    }
+}
+
+#[stable(feature = "assertunwindsafe_default", since = "1.62.0")]
+impl<T: Default> Default for AssertUnwindSafe<T> {
+    fn default() -> Self {
+        Self(Default::default())
+    }
+}
+
+#[stable(feature = "futures_api", since = "1.36.0")]
+impl<F: Future> Future for AssertUnwindSafe<F> {
+    type Output = F::Output;
+
+    fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
+        // SAFETY: pin projection. AssertUnwindSafe follows structural pinning.
+        let pinned_field = unsafe { Pin::map_unchecked_mut(self, |x| &mut x.0) };
+        F::poll(pinned_field, cx)
+    }
+}
+
+#[unstable(feature = "async_iterator", issue = "79024")]
+impl<S: AsyncIterator> AsyncIterator for AssertUnwindSafe<S> {
+    type Item = S::Item;
+
+    fn poll_next(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<S::Item>> {
+        // SAFETY: pin projection. AssertUnwindSafe follows structural pinning.
+        unsafe { self.map_unchecked_mut(|x| &mut x.0) }.poll_next(cx)
+    }
+
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.0.size_hint()
+    }
+}