Auto merge of #55982 - alexcrichton:panic-extern-abort, r=zackmdavis
rustc: Switch `extern` functions to abort by default on panic
This was intended to land way back in 1.24, but it was backed out due to
breakage which has long since been fixed. An unstable `#[unwind]`
attribute can be used to tweak the behavior here, but this is currently
simply switching rustc's internal default to abort-by-default if an
`extern` function panics, making our codegen sound primarily (as
currently you can produce UB with safe code)
Closes #52652
diff --git a/src/libcore/marker.rs b/src/libcore/marker.rs
index 0d43f92..d3d1612 100644
--- a/src/libcore/marker.rs
+++ b/src/libcore/marker.rs
@@ -640,15 +640,15 @@
#[unstable(feature = "pin", issue = "49150")]
pub auto trait Unpin {}
-/// A type which does not implement `Unpin`.
+/// A marker type which does not implement `Unpin`.
///
-/// If a type contains a `Pinned`, it will not implement `Unpin` by default.
+/// If a type contains a `PhantomPinned`, it will not implement `Unpin` by default.
#[unstable(feature = "pin", issue = "49150")]
#[derive(Debug, Copy, Clone, Eq, PartialEq, Ord, PartialOrd, Hash)]
-pub struct Pinned;
+pub struct PhantomPinned;
#[unstable(feature = "pin", issue = "49150")]
-impl !Unpin for Pinned {}
+impl !Unpin for PhantomPinned {}
#[unstable(feature = "pin", issue = "49150")]
impl<'a, T: ?Sized + 'a> Unpin for &'a T {}
diff --git a/src/libcore/pin.rs b/src/libcore/pin.rs
index aa51555..0ad6e8c 100644
--- a/src/libcore/pin.rs
+++ b/src/libcore/pin.rs
@@ -7,23 +7,33 @@
//! since moving an object with pointers to itself will invalidate them,
//! which could cause undefined behavior.
//!
-//! In order to prevent objects from moving, they must be pinned
-//! by wrapping a pointer to the data in the [`Pin`] type. A pointer wrapped
-//! in a `Pin` is otherwise equivalent to its normal version, e.g., `Pin<Box<T>>`
-//! and `Box<T>` work the same way except that the first is pinning the value
-//! of `T` in place.
+//! By default, all types in Rust are movable. Rust allows passing all types by-value,
+//! and common smart-pointer types such as `Box`, `Rc`, and `&mut` allow replacing and
+//! moving the values they contain. In order to prevent objects from moving, they must
+//! be pinned by wrapping a pointer to the data in the [`Pin`] type.
+//! Doing this prohibits moving the value behind the pointer.
+//! For example, `Pin<Box<T>>` functions much like a regular `Box<T>`,
+//! but doesn't allow moving `T`. The pointer value itself (the `Box`) can still be moved,
+//! but the value behind it cannot.
//!
-//! First of all, these are pointer types because pinned data mustn't be passed around by value
-//! (that would change its location in memory).
-//! Secondly, since data can be moved out of `&mut` and `Box` with functions such as [`swap`],
-//! which causes their contents to swap places in memory,
-//! we need dedicated types that prohibit such operations.
+//! Since data can be moved out of `&mut` and `Box` with functions such as [`swap`],
+//! changing the location of the underlying data, [`Pin`] prohibits accessing the
+//! underlying pointer type (the `&mut` or `Box`) directly, and provides its own set of
+//! APIs for accessing and using the value. [`Pin`] also guarantees that no other
+//! functions will move the pointed-to value. This allows for the creation of
+//! self-references and other special behaviors that are only possible for unmovable
+//! values.
//!
-//! However, these restrictions are usually not necessary,
-//! so most types implement the [`Unpin`] auto-trait,
-//! which indicates that the type can be moved out safely.
-//! Doing so removes the limitations of pinning types,
-//! making them the same as their non-pinning counterparts.
+//! However, these restrictions are usually not necessary. Many types are always freely
+//! movable. These types implement the [`Unpin`] auto-trait, which nullifies the affect
+//! of [`Pin`]. For `T: Unpin`, `Pin<Box<T>>` and `Box<T>` function identically, as do
+//! `Pin<&mut T>` and `&mut T`.
+//!
+//! Note that pinning and `Unpin` only affect the pointed-to type. For example, whether
+//! or not `Box<T>` is `Unpin` has no affect on the behavior of `Pin<Box<T>>`. Similarly,
+//! `Pin<Box<T>>` and `Pin<&mut T>` are always `Unpin` themselves, even though the
+//! `T` underneath them isn't, because the pointers in `Pin<Box<_>>` and `Pin<&mut _>`
+//! are always freely movable, even if the data they point to isn't.
//!
//! [`Pin`]: struct.Pin.html
//! [`Unpin`]: trait.Unpin.html
@@ -36,7 +46,7 @@
//! #![feature(pin)]
//!
//! use std::pin::Pin;
-//! use std::marker::Pinned;
+//! use std::marker::PhantomPinned;
//! use std::ptr::NonNull;
//!
//! // This is a self-referential struct since the slice field points to the data field.
@@ -47,7 +57,7 @@
//! struct Unmovable {
//! data: String,
//! slice: NonNull<String>,
-//! _pin: Pinned,
+//! _pin: PhantomPinned,
//! }
//!
//! impl Unmovable {
@@ -60,7 +70,7 @@
//! // we only create the pointer once the data is in place
//! // otherwise it will have already moved before we even started
//! slice: NonNull::dangling(),
-//! _pin: Pinned,
+//! _pin: PhantomPinned,
//! };
//! let mut boxed = Box::pinned(res);
//!
diff --git a/src/tools/build-manifest/src/main.rs b/src/tools/build-manifest/src/main.rs
index 896b380..695ca74 100644
--- a/src/tools/build-manifest/src/main.rs
+++ b/src/tools/build-manifest/src/main.rs
@@ -623,6 +623,7 @@
let mut cmd = Command::new("gpg");
cmd.arg("--no-tty")
.arg("--yes")
+ .arg("--batch")
.arg("--passphrase-fd").arg("0")
.arg("--personal-digest-preferences").arg("SHA512")
.arg("--armor")
