From 4e17994b2ca5da45f219ad09cad591fc7d31dd59 Mon Sep 17 00:00:00 2001 From: David Tolnay Date: Wed, 28 Apr 2021 08:39:23 -0700 Subject: [PATCH] Move UnwindSafe, RefUnwindSafe, AssertUnwindSafe to core --- library/alloc/src/lib.rs | 1 + library/alloc/src/panic.rs | 11 + library/core/src/panic.rs | 3 + library/core/src/panic/unwind_safe.rs | 300 ++++++++++++++++++++++++ library/std/src/panic.rs | 313 +------------------------- 5 files changed, 319 insertions(+), 309 deletions(-) create mode 100644 library/alloc/src/panic.rs create mode 100644 library/core/src/panic/unwind_safe.rs diff --git a/library/alloc/src/lib.rs b/library/alloc/src/lib.rs index d2ececaa9759f..12a5868db7417 100644 --- a/library/alloc/src/lib.rs +++ b/library/alloc/src/lib.rs @@ -177,6 +177,7 @@ mod boxed { pub mod borrow; pub mod collections; pub mod fmt; +mod panic; pub mod prelude; pub mod raw_vec; pub mod rc; diff --git a/library/alloc/src/panic.rs b/library/alloc/src/panic.rs new file mode 100644 index 0000000000000..666d4fa45aae2 --- /dev/null +++ b/library/alloc/src/panic.rs @@ -0,0 +1,11 @@ +use crate::rc::Rc; +use crate::sync::Arc; +use core::panic::{RefUnwindSafe, UnwindSafe}; + +// not covered via the Shared impl above b/c the inner contents use +// Cell/AtomicUsize, but the usage here is unwind safe so we can lift the +// impl up one level to Arc/Rc itself +#[stable(feature = "catch_unwind", since = "1.9.0")] +impl UnwindSafe for Rc {} +#[stable(feature = "catch_unwind", since = "1.9.0")] +impl UnwindSafe for Arc {} diff --git a/library/core/src/panic.rs b/library/core/src/panic.rs index 87325eabed31e..463bec37265d5 100644 --- a/library/core/src/panic.rs +++ b/library/core/src/panic.rs @@ -4,6 +4,7 @@ mod location; mod panic_info; +mod unwind_safe; use crate::any::Any; @@ -11,6 +12,8 @@ use crate::any::Any; pub use self::location::Location; #[stable(feature = "panic_hooks", since = "1.10.0")] pub use self::panic_info::PanicInfo; +#[stable(feature = "catch_unwind", since = "1.9.0")] +pub use self::unwind_safe::{AssertUnwindSafe, RefUnwindSafe, UnwindSafe}; #[doc(hidden)] #[unstable(feature = "edition_panic", issue = "none", reason = "use panic!() instead")] diff --git a/library/core/src/panic/unwind_safe.rs b/library/core/src/panic/unwind_safe.rs new file mode 100644 index 0000000000000..c889dd81846f9 --- /dev/null +++ b/library/core/src/panic/unwind_safe.rs @@ -0,0 +1,300 @@ +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::stream::Stream; +use crate::sync::atomic; +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. +/// +/// ## 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` 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`, 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. +/// +/// # 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(#[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 !UnwindSafe for &mut T {} +#[stable(feature = "catch_unwind", since = "1.9.0")] +impl UnwindSafe for &T {} +#[stable(feature = "catch_unwind", since = "1.9.0")] +impl UnwindSafe for *const T {} +#[stable(feature = "catch_unwind", since = "1.9.0")] +impl UnwindSafe for *mut T {} +#[unstable(feature = "ptr_internals", issue = "none")] +impl UnwindSafe for Unique {} +#[stable(feature = "nonnull", since = "1.25.0")] +impl UnwindSafe for NonNull {} +#[stable(feature = "catch_unwind", since = "1.9.0")] +impl UnwindSafe for AssertUnwindSafe {} + +// 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 !RefUnwindSafe for UnsafeCell {} +#[stable(feature = "catch_unwind", since = "1.9.0")] +impl RefUnwindSafe for AssertUnwindSafe {} + +#[cfg(target_has_atomic_load_store = "ptr")] +#[stable(feature = "unwind_safe_atomic_refs", since = "1.14.0")] +impl RefUnwindSafe for atomic::AtomicIsize {} +#[cfg(target_has_atomic_load_store = "8")] +#[stable(feature = "integer_atomics_stable", since = "1.34.0")] +impl RefUnwindSafe for atomic::AtomicI8 {} +#[cfg(target_has_atomic_load_store = "16")] +#[stable(feature = "integer_atomics_stable", since = "1.34.0")] +impl RefUnwindSafe for atomic::AtomicI16 {} +#[cfg(target_has_atomic_load_store = "32")] +#[stable(feature = "integer_atomics_stable", since = "1.34.0")] +impl RefUnwindSafe for atomic::AtomicI32 {} +#[cfg(target_has_atomic_load_store = "64")] +#[stable(feature = "integer_atomics_stable", since = "1.34.0")] +impl RefUnwindSafe for atomic::AtomicI64 {} +#[cfg(target_has_atomic_load_store = "128")] +#[unstable(feature = "integer_atomics", issue = "32976")] +impl RefUnwindSafe for atomic::AtomicI128 {} + +#[cfg(target_has_atomic_load_store = "ptr")] +#[stable(feature = "unwind_safe_atomic_refs", since = "1.14.0")] +impl RefUnwindSafe for atomic::AtomicUsize {} +#[cfg(target_has_atomic_load_store = "8")] +#[stable(feature = "integer_atomics_stable", since = "1.34.0")] +impl RefUnwindSafe for atomic::AtomicU8 {} +#[cfg(target_has_atomic_load_store = "16")] +#[stable(feature = "integer_atomics_stable", since = "1.34.0")] +impl RefUnwindSafe for atomic::AtomicU16 {} +#[cfg(target_has_atomic_load_store = "32")] +#[stable(feature = "integer_atomics_stable", since = "1.34.0")] +impl RefUnwindSafe for atomic::AtomicU32 {} +#[cfg(target_has_atomic_load_store = "64")] +#[stable(feature = "integer_atomics_stable", since = "1.34.0")] +impl RefUnwindSafe for atomic::AtomicU64 {} +#[cfg(target_has_atomic_load_store = "128")] +#[unstable(feature = "integer_atomics", issue = "32976")] +impl RefUnwindSafe for atomic::AtomicU128 {} + +#[cfg(target_has_atomic_load_store = "8")] +#[stable(feature = "unwind_safe_atomic_refs", since = "1.14.0")] +impl RefUnwindSafe for atomic::AtomicBool {} + +#[cfg(target_has_atomic_load_store = "ptr")] +#[stable(feature = "unwind_safe_atomic_refs", since = "1.14.0")] +impl RefUnwindSafe for atomic::AtomicPtr {} + +#[stable(feature = "catch_unwind", since = "1.9.0")] +impl Deref for AssertUnwindSafe { + type Target = T; + + fn deref(&self) -> &T { + &self.0 + } +} + +#[stable(feature = "catch_unwind", since = "1.9.0")] +impl DerefMut for AssertUnwindSafe { + fn deref_mut(&mut self) -> &mut T { + &mut self.0 + } +} + +#[stable(feature = "catch_unwind", since = "1.9.0")] +impl R> FnOnce<()> for AssertUnwindSafe { + type Output = R; + + extern "rust-call" fn call_once(self, _args: ()) -> R { + (self.0)() + } +} + +#[stable(feature = "std_debug", since = "1.16.0")] +impl fmt::Debug for AssertUnwindSafe { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.debug_tuple("AssertUnwindSafe").field(&self.0).finish() + } +} + +#[stable(feature = "futures_api", since = "1.36.0")] +impl Future for AssertUnwindSafe { + type Output = F::Output; + + fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll { + let pinned_field = unsafe { Pin::map_unchecked_mut(self, |x| &mut x.0) }; + F::poll(pinned_field, cx) + } +} + +#[unstable(feature = "async_stream", issue = "79024")] +impl Stream for AssertUnwindSafe { + type Item = S::Item; + + fn poll_next(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll> { + unsafe { self.map_unchecked_mut(|x| &mut x.0) }.poll_next(cx) + } + + fn size_hint(&self) -> (usize, Option) { + self.0.size_hint() + } +} diff --git a/library/std/src/panic.rs b/library/std/src/panic.rs index 9c597e17bb509..c1c039584979d 100644 --- a/library/std/src/panic.rs +++ b/library/std/src/panic.rs @@ -3,19 +3,9 @@ #![stable(feature = "std_panic", since = "1.9.0")] use crate::any::Any; -use crate::cell::UnsafeCell; use crate::collections; -use crate::fmt; -use crate::future::Future; -use crate::ops::{Deref, DerefMut}; use crate::panicking; -use crate::pin::Pin; -use crate::ptr::{NonNull, Unique}; -use crate::rc::Rc; -use crate::stream::Stream; -use crate::sync::atomic; -use crate::sync::{Arc, Mutex, RwLock}; -use crate::task::{Context, Poll}; +use crate::sync::{Mutex, RwLock}; use crate::thread::Result; #[doc(hidden)] @@ -45,6 +35,9 @@ pub use crate::panicking::{set_hook, take_hook}; #[stable(feature = "panic_hooks", since = "1.10.0")] pub use core::panic::{Location, PanicInfo}; +#[stable(feature = "catch_unwind", since = "1.9.0")] +pub use core::panic::{AssertUnwindSafe, RefUnwindSafe, UnwindSafe}; + /// Panic the current thread with the given message as the panic payload. /// /// The message can be of any (`Any + Send`) type, not just strings. @@ -60,259 +53,16 @@ pub fn panic_any(msg: M) -> ! { crate::panicking::begin_panic(msg); } -/// 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. -/// -/// ## 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` 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`, 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. -/// -/// # 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(#[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 !UnwindSafe for &mut T {} -#[stable(feature = "catch_unwind", since = "1.9.0")] -impl UnwindSafe for &T {} -#[stable(feature = "catch_unwind", since = "1.9.0")] -impl UnwindSafe for *const T {} -#[stable(feature = "catch_unwind", since = "1.9.0")] -impl UnwindSafe for *mut T {} -#[unstable(feature = "ptr_internals", issue = "none")] -impl UnwindSafe for Unique {} -#[stable(feature = "nonnull", since = "1.25.0")] -impl UnwindSafe for NonNull {} #[stable(feature = "catch_unwind", since = "1.9.0")] impl UnwindSafe for Mutex {} #[stable(feature = "catch_unwind", since = "1.9.0")] impl UnwindSafe for RwLock {} -#[stable(feature = "catch_unwind", since = "1.9.0")] -impl UnwindSafe for AssertUnwindSafe {} - -// not covered via the Shared impl above b/c the inner contents use -// Cell/AtomicUsize, but the usage here is unwind safe so we can lift the -// impl up one level to Arc/Rc itself -#[stable(feature = "catch_unwind", since = "1.9.0")] -impl UnwindSafe for Rc {} -#[stable(feature = "catch_unwind", since = "1.9.0")] -impl UnwindSafe for Arc {} - -// 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 !RefUnwindSafe for UnsafeCell {} -#[stable(feature = "catch_unwind", since = "1.9.0")] -impl RefUnwindSafe for AssertUnwindSafe {} #[stable(feature = "unwind_safe_lock_refs", since = "1.12.0")] impl RefUnwindSafe for Mutex {} #[stable(feature = "unwind_safe_lock_refs", since = "1.12.0")] impl RefUnwindSafe for RwLock {} -#[cfg(target_has_atomic_load_store = "ptr")] -#[stable(feature = "unwind_safe_atomic_refs", since = "1.14.0")] -impl RefUnwindSafe for atomic::AtomicIsize {} -#[cfg(target_has_atomic_load_store = "8")] -#[stable(feature = "integer_atomics_stable", since = "1.34.0")] -impl RefUnwindSafe for atomic::AtomicI8 {} -#[cfg(target_has_atomic_load_store = "16")] -#[stable(feature = "integer_atomics_stable", since = "1.34.0")] -impl RefUnwindSafe for atomic::AtomicI16 {} -#[cfg(target_has_atomic_load_store = "32")] -#[stable(feature = "integer_atomics_stable", since = "1.34.0")] -impl RefUnwindSafe for atomic::AtomicI32 {} -#[cfg(target_has_atomic_load_store = "64")] -#[stable(feature = "integer_atomics_stable", since = "1.34.0")] -impl RefUnwindSafe for atomic::AtomicI64 {} -#[cfg(target_has_atomic_load_store = "128")] -#[unstable(feature = "integer_atomics", issue = "32976")] -impl RefUnwindSafe for atomic::AtomicI128 {} - -#[cfg(target_has_atomic_load_store = "ptr")] -#[stable(feature = "unwind_safe_atomic_refs", since = "1.14.0")] -impl RefUnwindSafe for atomic::AtomicUsize {} -#[cfg(target_has_atomic_load_store = "8")] -#[stable(feature = "integer_atomics_stable", since = "1.34.0")] -impl RefUnwindSafe for atomic::AtomicU8 {} -#[cfg(target_has_atomic_load_store = "16")] -#[stable(feature = "integer_atomics_stable", since = "1.34.0")] -impl RefUnwindSafe for atomic::AtomicU16 {} -#[cfg(target_has_atomic_load_store = "32")] -#[stable(feature = "integer_atomics_stable", since = "1.34.0")] -impl RefUnwindSafe for atomic::AtomicU32 {} -#[cfg(target_has_atomic_load_store = "64")] -#[stable(feature = "integer_atomics_stable", since = "1.34.0")] -impl RefUnwindSafe for atomic::AtomicU64 {} -#[cfg(target_has_atomic_load_store = "128")] -#[unstable(feature = "integer_atomics", issue = "32976")] -impl RefUnwindSafe for atomic::AtomicU128 {} - -#[cfg(target_has_atomic_load_store = "8")] -#[stable(feature = "unwind_safe_atomic_refs", since = "1.14.0")] -impl RefUnwindSafe for atomic::AtomicBool {} - -#[cfg(target_has_atomic_load_store = "ptr")] -#[stable(feature = "unwind_safe_atomic_refs", since = "1.14.0")] -impl RefUnwindSafe for atomic::AtomicPtr {} - // https://github.com/rust-lang/rust/issues/62301 #[stable(feature = "hashbrown", since = "1.36.0")] impl UnwindSafe for collections::HashMap @@ -323,61 +73,6 @@ where { } -#[stable(feature = "catch_unwind", since = "1.9.0")] -impl Deref for AssertUnwindSafe { - type Target = T; - - fn deref(&self) -> &T { - &self.0 - } -} - -#[stable(feature = "catch_unwind", since = "1.9.0")] -impl DerefMut for AssertUnwindSafe { - fn deref_mut(&mut self) -> &mut T { - &mut self.0 - } -} - -#[stable(feature = "catch_unwind", since = "1.9.0")] -impl R> FnOnce<()> for AssertUnwindSafe { - type Output = R; - - extern "rust-call" fn call_once(self, _args: ()) -> R { - (self.0)() - } -} - -#[stable(feature = "std_debug", since = "1.16.0")] -impl fmt::Debug for AssertUnwindSafe { - fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { - f.debug_tuple("AssertUnwindSafe").field(&self.0).finish() - } -} - -#[stable(feature = "futures_api", since = "1.36.0")] -impl Future for AssertUnwindSafe { - type Output = F::Output; - - fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll { - let pinned_field = unsafe { Pin::map_unchecked_mut(self, |x| &mut x.0) }; - F::poll(pinned_field, cx) - } -} - -#[unstable(feature = "async_stream", issue = "79024")] -impl Stream for AssertUnwindSafe { - type Item = S::Item; - - fn poll_next(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll> { - unsafe { self.map_unchecked_mut(|x| &mut x.0) }.poll_next(cx) - } - - fn size_hint(&self) -> (usize, Option) { - self.0.size_hint() - } -} - /// Invokes a closure, capturing the cause of an unwinding panic if one occurs. /// /// This function will return `Ok` with the closure's result if the closure