Move UnwindSafe, RefUnwindSafe, AssertUnwindSafe to core
This commit is contained in:
David Tolnay
parent
76e73b74a6
commit
4e17994b2c
@ -177,6 +177,7 @@ mod boxed {
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pub mod borrow;
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pub mod collections;
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pub mod fmt;
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mod panic;
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pub mod prelude;
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pub mod raw_vec;
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pub mod rc;
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11
library/alloc/src/panic.rs
Normal file
11
library/alloc/src/panic.rs
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@ -0,0 +1,11 @@
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use crate::rc::Rc;
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use crate::sync::Arc;
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use core::panic::{RefUnwindSafe, UnwindSafe};
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// not covered via the Shared impl above b/c the inner contents use
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// Cell/AtomicUsize, but the usage here is unwind safe so we can lift the
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// impl up one level to Arc/Rc itself
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#[stable(feature = "catch_unwind", since = "1.9.0")]
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impl<T: RefUnwindSafe + ?Sized> UnwindSafe for Rc<T> {}
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#[stable(feature = "catch_unwind", since = "1.9.0")]
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impl<T: RefUnwindSafe + ?Sized> UnwindSafe for Arc<T> {}
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@ -4,6 +4,7 @@
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mod location;
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mod panic_info;
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mod unwind_safe;
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use crate::any::Any;
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@ -11,6 +12,8 @@ use crate::any::Any;
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pub use self::location::Location;
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#[stable(feature = "panic_hooks", since = "1.10.0")]
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pub use self::panic_info::PanicInfo;
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#[stable(feature = "catch_unwind", since = "1.9.0")]
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pub use self::unwind_safe::{AssertUnwindSafe, RefUnwindSafe, UnwindSafe};
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#[doc(hidden)]
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#[unstable(feature = "edition_panic", issue = "none", reason = "use panic!() instead")]
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300
library/core/src/panic/unwind_safe.rs
Normal file
300
library/core/src/panic/unwind_safe.rs
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@ -0,0 +1,300 @@
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use crate::cell::UnsafeCell;
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use crate::fmt;
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use crate::future::Future;
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use crate::ops::{Deref, DerefMut};
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use crate::pin::Pin;
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use crate::ptr::{NonNull, Unique};
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use crate::stream::Stream;
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use crate::sync::atomic;
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use crate::task::{Context, Poll};
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/// A marker trait which represents "panic safe" types in Rust.
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///
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/// This trait is implemented by default for many types and behaves similarly in
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/// terms of inference of implementation to the [`Send`] and [`Sync`] traits. The
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/// purpose of this trait is to encode what types are safe to cross a [`catch_unwind`]
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/// boundary with no fear of unwind safety.
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///
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/// ## What is unwind safety?
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///
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/// In Rust a function can "return" early if it either panics or calls a
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/// function which transitively panics. This sort of control flow is not always
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/// anticipated, and has the possibility of causing subtle bugs through a
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/// combination of two critical components:
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///
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/// 1. A data structure is in a temporarily invalid state when the thread
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/// panics.
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/// 2. This broken invariant is then later observed.
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///
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/// Typically in Rust, it is difficult to perform step (2) because catching a
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/// panic involves either spawning a thread (which in turns makes it difficult
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/// to later witness broken invariants) or using the `catch_unwind` function in this
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/// module. Additionally, even if an invariant is witnessed, it typically isn't a
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/// problem in Rust because there are no uninitialized values (like in C or C++).
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///
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/// It is possible, however, for **logical** invariants to be broken in Rust,
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/// which can end up causing behavioral bugs. Another key aspect of unwind safety
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/// in Rust is that, in the absence of `unsafe` code, a panic cannot lead to
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/// memory unsafety.
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///
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/// That was a bit of a whirlwind tour of unwind safety, but for more information
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/// about unwind safety and how it applies to Rust, see an [associated RFC][rfc].
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///
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/// [rfc]: https://github.com/rust-lang/rfcs/blob/master/text/1236-stabilize-catch-panic.md
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///
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/// ## What is `UnwindSafe`?
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///
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/// Now that we've got an idea of what unwind safety is in Rust, it's also
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/// important to understand what this trait represents. As mentioned above, one
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/// way to witness broken invariants is through the `catch_unwind` function in this
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/// module as it allows catching a panic and then re-using the environment of
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/// the closure.
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///
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/// Simply put, a type `T` implements `UnwindSafe` if it cannot easily allow
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/// witnessing a broken invariant through the use of `catch_unwind` (catching a
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/// panic). This trait is an auto trait, so it is automatically implemented for
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/// many types, and it is also structurally composed (e.g., a struct is unwind
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/// safe if all of its components are unwind safe).
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///
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/// Note, however, that this is not an unsafe trait, so there is not a succinct
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/// contract that this trait is providing. Instead it is intended as more of a
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/// "speed bump" to alert users of `catch_unwind` that broken invariants may be
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/// witnessed and may need to be accounted for.
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///
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/// ## Who implements `UnwindSafe`?
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///
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/// Types such as `&mut T` and `&RefCell<T>` are examples which are **not**
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/// unwind safe. The general idea is that any mutable state which can be shared
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/// across `catch_unwind` is not unwind safe by default. This is because it is very
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/// easy to witness a broken invariant outside of `catch_unwind` as the data is
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/// simply accessed as usual.
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///
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/// Types like `&Mutex<T>`, however, are unwind safe because they implement
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/// poisoning by default. They still allow witnessing a broken invariant, but
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/// they already provide their own "speed bumps" to do so.
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///
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/// ## When should `UnwindSafe` be used?
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///
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/// It is not intended that most types or functions need to worry about this trait.
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/// It is only used as a bound on the `catch_unwind` function and as mentioned
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/// above, the lack of `unsafe` means it is mostly an advisory. The
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/// [`AssertUnwindSafe`] wrapper struct can be used to force this trait to be
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/// implemented for any closed over variables passed to `catch_unwind`.
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#[stable(feature = "catch_unwind", since = "1.9.0")]
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#[cfg_attr(not(test), rustc_diagnostic_item = "unwind_safe_trait")]
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#[rustc_on_unimplemented(
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message = "the type `{Self}` may not be safely transferred across an unwind boundary",
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label = "`{Self}` may not be safely transferred across an unwind boundary"
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)]
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pub auto trait UnwindSafe {}
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/// A marker trait representing types where a shared reference is considered
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/// unwind safe.
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///
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/// This trait is namely not implemented by [`UnsafeCell`], the root of all
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/// interior mutability.
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///
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/// This is a "helper marker trait" used to provide impl blocks for the
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/// [`UnwindSafe`] trait, for more information see that documentation.
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#[stable(feature = "catch_unwind", since = "1.9.0")]
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#[cfg_attr(not(test), rustc_diagnostic_item = "ref_unwind_safe_trait")]
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#[rustc_on_unimplemented(
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message = "the type `{Self}` may contain interior mutability and a reference may not be safely \
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transferrable across a catch_unwind boundary",
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label = "`{Self}` may contain interior mutability and a reference may not be safely \
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transferrable across a catch_unwind boundary"
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)]
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pub auto trait RefUnwindSafe {}
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/// A simple wrapper around a type to assert that it is unwind safe.
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///
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/// When using [`catch_unwind`] it may be the case that some of the closed over
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/// variables are not unwind safe. For example if `&mut T` is captured the
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/// compiler will generate a warning indicating that it is not unwind safe. It
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/// might not be the case, however, that this is actually a problem due to the
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/// specific usage of [`catch_unwind`] if unwind safety is specifically taken into
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/// account. This wrapper struct is useful for a quick and lightweight
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/// annotation that a variable is indeed unwind safe.
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///
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/// # Examples
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///
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/// One way to use `AssertUnwindSafe` is to assert that the entire closure
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/// itself is unwind safe, bypassing all checks for all variables:
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///
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/// ```
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/// use std::panic::{self, AssertUnwindSafe};
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///
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/// let mut variable = 4;
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///
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/// // This code will not compile because the closure captures `&mut variable`
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/// // which is not considered unwind safe by default.
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///
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/// // panic::catch_unwind(|| {
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/// // variable += 3;
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/// // });
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///
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/// // This, however, will compile due to the `AssertUnwindSafe` wrapper
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/// let result = panic::catch_unwind(AssertUnwindSafe(|| {
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/// variable += 3;
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/// }));
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/// // ...
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/// ```
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///
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/// Wrapping the entire closure amounts to a blanket assertion that all captured
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/// variables are unwind safe. This has the downside that if new captures are
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/// added in the future, they will also be considered unwind safe. Therefore,
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/// you may prefer to just wrap individual captures, as shown below. This is
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/// more annotation, but it ensures that if a new capture is added which is not
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/// unwind safe, you will get a compilation error at that time, which will
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/// allow you to consider whether that new capture in fact represent a bug or
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/// not.
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///
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/// ```
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/// use std::panic::{self, AssertUnwindSafe};
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///
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/// let mut variable = 4;
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/// let other_capture = 3;
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///
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/// let result = {
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/// let mut wrapper = AssertUnwindSafe(&mut variable);
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/// panic::catch_unwind(move || {
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/// **wrapper += other_capture;
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/// })
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/// };
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/// // ...
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/// ```
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#[stable(feature = "catch_unwind", since = "1.9.0")]
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pub struct AssertUnwindSafe<T>(#[stable(feature = "catch_unwind", since = "1.9.0")] pub T);
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// Implementations of the `UnwindSafe` trait:
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//
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// * By default everything is unwind safe
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// * pointers T contains mutability of some form are not unwind safe
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// * Unique, an owning pointer, lifts an implementation
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// * Types like Mutex/RwLock which are explicitly poisoned are unwind safe
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// * Our custom AssertUnwindSafe wrapper is indeed unwind safe
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#[stable(feature = "catch_unwind", since = "1.9.0")]
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impl<T: ?Sized> !UnwindSafe for &mut T {}
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#[stable(feature = "catch_unwind", since = "1.9.0")]
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impl<T: RefUnwindSafe + ?Sized> UnwindSafe for &T {}
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#[stable(feature = "catch_unwind", since = "1.9.0")]
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impl<T: RefUnwindSafe + ?Sized> UnwindSafe for *const T {}
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#[stable(feature = "catch_unwind", since = "1.9.0")]
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impl<T: RefUnwindSafe + ?Sized> UnwindSafe for *mut T {}
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#[unstable(feature = "ptr_internals", issue = "none")]
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impl<T: UnwindSafe + ?Sized> UnwindSafe for Unique<T> {}
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#[stable(feature = "nonnull", since = "1.25.0")]
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impl<T: RefUnwindSafe + ?Sized> UnwindSafe for NonNull<T> {}
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#[stable(feature = "catch_unwind", since = "1.9.0")]
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impl<T> UnwindSafe for AssertUnwindSafe<T> {}
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// Pretty simple implementations for the `RefUnwindSafe` marker trait,
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// basically just saying that `UnsafeCell` is the
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// only thing which doesn't implement it (which then transitively applies to
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// everything else).
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#[stable(feature = "catch_unwind", since = "1.9.0")]
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impl<T: ?Sized> !RefUnwindSafe for UnsafeCell<T> {}
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#[stable(feature = "catch_unwind", since = "1.9.0")]
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impl<T> RefUnwindSafe for AssertUnwindSafe<T> {}
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#[cfg(target_has_atomic_load_store = "ptr")]
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#[stable(feature = "unwind_safe_atomic_refs", since = "1.14.0")]
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impl RefUnwindSafe for atomic::AtomicIsize {}
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#[cfg(target_has_atomic_load_store = "8")]
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#[stable(feature = "integer_atomics_stable", since = "1.34.0")]
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impl RefUnwindSafe for atomic::AtomicI8 {}
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#[cfg(target_has_atomic_load_store = "16")]
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#[stable(feature = "integer_atomics_stable", since = "1.34.0")]
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impl RefUnwindSafe for atomic::AtomicI16 {}
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#[cfg(target_has_atomic_load_store = "32")]
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#[stable(feature = "integer_atomics_stable", since = "1.34.0")]
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impl RefUnwindSafe for atomic::AtomicI32 {}
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#[cfg(target_has_atomic_load_store = "64")]
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#[stable(feature = "integer_atomics_stable", since = "1.34.0")]
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impl RefUnwindSafe for atomic::AtomicI64 {}
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#[cfg(target_has_atomic_load_store = "128")]
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#[unstable(feature = "integer_atomics", issue = "32976")]
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impl RefUnwindSafe for atomic::AtomicI128 {}
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#[cfg(target_has_atomic_load_store = "ptr")]
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#[stable(feature = "unwind_safe_atomic_refs", since = "1.14.0")]
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impl RefUnwindSafe for atomic::AtomicUsize {}
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#[cfg(target_has_atomic_load_store = "8")]
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#[stable(feature = "integer_atomics_stable", since = "1.34.0")]
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impl RefUnwindSafe for atomic::AtomicU8 {}
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#[cfg(target_has_atomic_load_store = "16")]
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#[stable(feature = "integer_atomics_stable", since = "1.34.0")]
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impl RefUnwindSafe for atomic::AtomicU16 {}
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#[cfg(target_has_atomic_load_store = "32")]
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#[stable(feature = "integer_atomics_stable", since = "1.34.0")]
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impl RefUnwindSafe for atomic::AtomicU32 {}
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#[cfg(target_has_atomic_load_store = "64")]
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#[stable(feature = "integer_atomics_stable", since = "1.34.0")]
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impl RefUnwindSafe for atomic::AtomicU64 {}
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#[cfg(target_has_atomic_load_store = "128")]
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#[unstable(feature = "integer_atomics", issue = "32976")]
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impl RefUnwindSafe for atomic::AtomicU128 {}
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#[cfg(target_has_atomic_load_store = "8")]
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#[stable(feature = "unwind_safe_atomic_refs", since = "1.14.0")]
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impl RefUnwindSafe for atomic::AtomicBool {}
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#[cfg(target_has_atomic_load_store = "ptr")]
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#[stable(feature = "unwind_safe_atomic_refs", since = "1.14.0")]
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impl<T> RefUnwindSafe for atomic::AtomicPtr<T> {}
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#[stable(feature = "catch_unwind", since = "1.9.0")]
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impl<T> Deref for AssertUnwindSafe<T> {
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type Target = T;
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fn deref(&self) -> &T {
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&self.0
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}
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}
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#[stable(feature = "catch_unwind", since = "1.9.0")]
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impl<T> DerefMut for AssertUnwindSafe<T> {
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fn deref_mut(&mut self) -> &mut T {
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&mut self.0
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}
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}
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#[stable(feature = "catch_unwind", since = "1.9.0")]
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impl<R, F: FnOnce() -> R> FnOnce<()> for AssertUnwindSafe<F> {
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type Output = R;
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extern "rust-call" fn call_once(self, _args: ()) -> R {
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(self.0)()
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}
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}
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#[stable(feature = "std_debug", since = "1.16.0")]
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impl<T: fmt::Debug> fmt::Debug for AssertUnwindSafe<T> {
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fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
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f.debug_tuple("AssertUnwindSafe").field(&self.0).finish()
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}
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}
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#[stable(feature = "futures_api", since = "1.36.0")]
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impl<F: Future> Future for AssertUnwindSafe<F> {
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type Output = F::Output;
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fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
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let pinned_field = unsafe { Pin::map_unchecked_mut(self, |x| &mut x.0) };
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F::poll(pinned_field, cx)
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}
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}
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#[unstable(feature = "async_stream", issue = "79024")]
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impl<S: Stream> Stream for AssertUnwindSafe<S> {
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type Item = S::Item;
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fn poll_next(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<S::Item>> {
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unsafe { self.map_unchecked_mut(|x| &mut x.0) }.poll_next(cx)
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}
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fn size_hint(&self) -> (usize, Option<usize>) {
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self.0.size_hint()
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}
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}
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@ -3,19 +3,9 @@
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#![stable(feature = "std_panic", since = "1.9.0")]
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use crate::any::Any;
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use crate::cell::UnsafeCell;
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use crate::collections;
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use crate::fmt;
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use crate::future::Future;
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use crate::ops::{Deref, DerefMut};
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use crate::panicking;
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use crate::pin::Pin;
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use crate::ptr::{NonNull, Unique};
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use crate::rc::Rc;
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use crate::stream::Stream;
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use crate::sync::atomic;
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use crate::sync::{Arc, Mutex, RwLock};
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use crate::task::{Context, Poll};
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use crate::sync::{Mutex, RwLock};
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use crate::thread::Result;
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#[doc(hidden)]
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@ -45,6 +35,9 @@ pub use crate::panicking::{set_hook, take_hook};
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#[stable(feature = "panic_hooks", since = "1.10.0")]
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pub use core::panic::{Location, PanicInfo};
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#[stable(feature = "catch_unwind", since = "1.9.0")]
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pub use core::panic::{AssertUnwindSafe, RefUnwindSafe, UnwindSafe};
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/// Panic the current thread with the given message as the panic payload.
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///
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/// The message can be of any (`Any + Send`) type, not just strings.
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@ -60,259 +53,16 @@ pub fn panic_any<M: 'static + Any + Send>(msg: M) -> ! {
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crate::panicking::begin_panic(msg);
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}
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/// A marker trait which represents "panic safe" types in Rust.
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///
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/// This trait is implemented by default for many types and behaves similarly in
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/// terms of inference of implementation to the [`Send`] and [`Sync`] traits. The
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/// purpose of this trait is to encode what types are safe to cross a [`catch_unwind`]
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/// boundary with no fear of unwind safety.
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///
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/// ## What is unwind safety?
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///
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/// In Rust a function can "return" early if it either panics or calls a
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/// function which transitively panics. This sort of control flow is not always
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/// anticipated, and has the possibility of causing subtle bugs through a
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/// combination of two critical components:
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///
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/// 1. A data structure is in a temporarily invalid state when the thread
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/// panics.
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/// 2. This broken invariant is then later observed.
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///
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/// Typically in Rust, it is difficult to perform step (2) because catching a
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/// 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.
|
||||
///
|
||||
/// # 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: ?Sized> UnwindSafe for Mutex<T> {}
|
||||
#[stable(feature = "catch_unwind", since = "1.9.0")]
|
||||
impl<T: ?Sized> UnwindSafe for RwLock<T> {}
|
||||
#[stable(feature = "catch_unwind", since = "1.9.0")]
|
||||
impl<T> UnwindSafe for AssertUnwindSafe<T> {}
|
||||
|
||||
// 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<T: RefUnwindSafe + ?Sized> UnwindSafe for Rc<T> {}
|
||||
#[stable(feature = "catch_unwind", since = "1.9.0")]
|
||||
impl<T: RefUnwindSafe + ?Sized> UnwindSafe for Arc<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> {}
|
||||
|
||||
#[stable(feature = "unwind_safe_lock_refs", since = "1.12.0")]
|
||||
impl<T: ?Sized> RefUnwindSafe for Mutex<T> {}
|
||||
#[stable(feature = "unwind_safe_lock_refs", since = "1.12.0")]
|
||||
impl<T: ?Sized> RefUnwindSafe for RwLock<T> {}
|
||||
|
||||
#[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<T> RefUnwindSafe for atomic::AtomicPtr<T> {}
|
||||
|
||||
// https://github.com/rust-lang/rust/issues/62301
|
||||
#[stable(feature = "hashbrown", since = "1.36.0")]
|
||||
impl<K, V, S> UnwindSafe for collections::HashMap<K, V, S>
|
||||
@ -323,61 +73,6 @@ where
|
||||
{
|
||||
}
|
||||
|
||||
#[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 = "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> {
|
||||
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<S: Stream> Stream for AssertUnwindSafe<S> {
|
||||
type Item = S::Item;
|
||||
|
||||
fn poll_next(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<S::Item>> {
|
||||
unsafe { self.map_unchecked_mut(|x| &mut x.0) }.poll_next(cx)
|
||||
}
|
||||
|
||||
fn size_hint(&self) -> (usize, Option<usize>) {
|
||||
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
|
||||
|
||||
Loading…
x
Reference in New Issue
Block a user