From bc3fb5245a248070b76e535be4f342e2be12a9b5 Mon Sep 17 00:00:00 2001
From: LegionMammal978 <mattlloydhouse@gmail.com>
Date: Tue, 16 Jan 2024 14:58:42 -0500
Subject: [PATCH] Rename `pointer` field on `Pin`
The internal, unstable field of `Pin` can conflict with fields from the
inner type accessed via the `Deref` impl. Rename it from `pointer` to
`__pointer`, to make it less likely to conflict with anything else.
---
.../src/fn_ctxt/suggestions.rs | 2 +-
library/core/src/pin.rs | 46 +++++++++++--------
src/etc/natvis/libcore.natvis | 4 +-
...ine_coroutine.main.Inline.panic-abort.diff | 2 +-
...ne_coroutine.main.Inline.panic-unwind.diff | 2 +-
.../feature-gate-unsafe_pin_internals.rs | 2 +-
tests/ui/pin-macro/cant_access_internals.rs | 2 +-
.../ui/pin-macro/cant_access_internals.stderr | 4 +-
8 files changed, 35 insertions(+), 29 deletions(-)
diff --git a/compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs b/compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs
index 81b7de7f634..83c544a9605 100644
--- a/compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs
+++ b/compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs
@@ -2038,7 +2038,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
let field_is_local = sole_field.did.is_local();
let field_is_accessible =
sole_field.vis.is_accessible_from(expr.hir_id.owner.def_id, self.tcx)
- // Skip suggestions for unstable public fields (for example `Pin::pointer`)
+ // Skip suggestions for unstable public fields (for example `Pin::__pointer`)
&& matches!(self.tcx.eval_stability(sole_field.did, None, expr.span, None), EvalResult::Allow | EvalResult::Unmarked);
if !field_is_local && !field_is_accessible {
diff --git a/library/core/src/pin.rs b/library/core/src/pin.rs
index bb6c81a486a..a0227d9130b 100644
--- a/library/core/src/pin.rs
+++ b/library/core/src/pin.rs
@@ -1092,14 +1092,20 @@ pub struct Pin<Ptr> {
// - deter downstream users from accessing it (which would be unsound!),
// - let the `pin!` macro access it (such a macro requires using struct
// literal syntax in order to benefit from lifetime extension).
- // Long-term, `unsafe` fields or macro hygiene are expected to offer more robust alternatives.
+ //
+ // However, if the `Deref` impl exposes a field with the same name as this
+ // field, then the two will collide, resulting in a confusing error when the
+ // user attempts to access the field through a `Pin<Ptr>`. Therefore, the
+ // name `__pointer` is designed to be unlikely to collide with any other
+ // field. Long-term, macro hygiene is expected to offer a more robust
+ // alternative, alongside `unsafe` fields.
#[unstable(feature = "unsafe_pin_internals", issue = "none")]
#[doc(hidden)]
- pub pointer: Ptr,
+ pub __pointer: Ptr,
}
// The following implementations aren't derived in order to avoid soundness
-// issues. `&self.pointer` should not be accessible to untrusted trait
+// issues. `&self.__pointer` should not be accessible to untrusted trait
// implementations.
//
// See <https://internals.rust-lang.org/t/unsoundness-in-pin/11311/73> for more details.
@@ -1212,7 +1218,7 @@ impl<Ptr: Deref<Target: Unpin>> Pin<Ptr> {
#[rustc_const_unstable(feature = "const_pin", issue = "76654")]
#[stable(feature = "pin_into_inner", since = "1.39.0")]
pub const fn into_inner(pin: Pin<Ptr>) -> Ptr {
- pin.pointer
+ pin.__pointer
}
}
@@ -1349,7 +1355,7 @@ impl<Ptr: Deref> Pin<Ptr> {
#[rustc_const_unstable(feature = "const_pin", issue = "76654")]
#[stable(feature = "pin", since = "1.33.0")]
pub const unsafe fn new_unchecked(pointer: Ptr) -> Pin<Ptr> {
- Pin { pointer }
+ Pin { __pointer: pointer }
}
/// Gets a shared reference to the pinned value this [`Pin`] points to.
@@ -1363,7 +1369,7 @@ impl<Ptr: Deref> Pin<Ptr> {
#[inline(always)]
pub fn as_ref(&self) -> Pin<&Ptr::Target> {
// SAFETY: see documentation on this function
- unsafe { Pin::new_unchecked(&*self.pointer) }
+ unsafe { Pin::new_unchecked(&*self.__pointer) }
}
/// Unwraps this `Pin<Ptr>`, returning the underlying `Ptr`.
@@ -1388,7 +1394,7 @@ impl<Ptr: Deref> Pin<Ptr> {
#[rustc_const_unstable(feature = "const_pin", issue = "76654")]
#[stable(feature = "pin_into_inner", since = "1.39.0")]
pub const unsafe fn into_inner_unchecked(pin: Pin<Ptr>) -> Ptr {
- pin.pointer
+ pin.__pointer
}
}
@@ -1426,7 +1432,7 @@ impl<Ptr: DerefMut> Pin<Ptr> {
#[inline(always)]
pub fn as_mut(&mut self) -> Pin<&mut Ptr::Target> {
// SAFETY: see documentation on this function
- unsafe { Pin::new_unchecked(&mut *self.pointer) }
+ unsafe { Pin::new_unchecked(&mut *self.__pointer) }
}
/// Assigns a new value to the memory location pointed to by the `Pin<Ptr>`.
@@ -1455,7 +1461,7 @@ impl<Ptr: DerefMut> Pin<Ptr> {
where
Ptr::Target: Sized,
{
- *(self.pointer) = value;
+ *(self.__pointer) = value;
}
}
@@ -1481,7 +1487,7 @@ impl<'a, T: ?Sized> Pin<&'a T> {
U: ?Sized,
F: FnOnce(&T) -> &U,
{
- let pointer = &*self.pointer;
+ let pointer = &*self.__pointer;
let new_pointer = func(pointer);
// SAFETY: the safety contract for `new_unchecked` must be
@@ -1511,7 +1517,7 @@ impl<'a, T: ?Sized> Pin<&'a T> {
#[rustc_const_unstable(feature = "const_pin", issue = "76654")]
#[stable(feature = "pin", since = "1.33.0")]
pub const fn get_ref(self) -> &'a T {
- self.pointer
+ self.__pointer
}
}
@@ -1522,7 +1528,7 @@ impl<'a, T: ?Sized> Pin<&'a mut T> {
#[rustc_const_unstable(feature = "const_pin", issue = "76654")]
#[stable(feature = "pin", since = "1.33.0")]
pub const fn into_ref(self) -> Pin<&'a T> {
- Pin { pointer: self.pointer }
+ Pin { __pointer: self.__pointer }
}
/// Gets a mutable reference to the data inside of this `Pin`.
@@ -1542,7 +1548,7 @@ impl<'a, T: ?Sized> Pin<&'a mut T> {
where
T: Unpin,
{
- self.pointer
+ self.__pointer
}
/// Gets a mutable reference to the data inside of this `Pin`.
@@ -1560,7 +1566,7 @@ impl<'a, T: ?Sized> Pin<&'a mut T> {
#[stable(feature = "pin", since = "1.33.0")]
#[rustc_const_unstable(feature = "const_pin", issue = "76654")]
pub const unsafe fn get_unchecked_mut(self) -> &'a mut T {
- self.pointer
+ self.__pointer
}
/// Construct a new pin by mapping the interior value.
@@ -1684,21 +1690,21 @@ impl<Ptr: Receiver> Receiver for Pin<Ptr> {}
#[stable(feature = "pin", since = "1.33.0")]
impl<Ptr: fmt::Debug> fmt::Debug for Pin<Ptr> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
- fmt::Debug::fmt(&self.pointer, f)
+ fmt::Debug::fmt(&self.__pointer, f)
}
}
#[stable(feature = "pin", since = "1.33.0")]
impl<Ptr: fmt::Display> fmt::Display for Pin<Ptr> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
- fmt::Display::fmt(&self.pointer, f)
+ fmt::Display::fmt(&self.__pointer, f)
}
}
#[stable(feature = "pin", since = "1.33.0")]
impl<Ptr: fmt::Pointer> fmt::Pointer for Pin<Ptr> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
- fmt::Pointer::fmt(&self.pointer, f)
+ fmt::Pointer::fmt(&self.__pointer, f)
}
}
@@ -1941,16 +1947,16 @@ pub macro pin($value:expr $(,)?) {
// instead, dropped _at the end of the enscoping block_.
// For instance,
// ```rust
- // let p = Pin { pointer: &mut <temporary> };
+ // let p = Pin { __pointer: &mut <temporary> };
// ```
// becomes:
// ```rust
// let mut anon = <temporary>;
- // let p = Pin { pointer: &mut anon };
+ // let p = Pin { __pointer: &mut anon };
// ```
// which is *exactly* what we want.
//
// See https://doc.rust-lang.org/1.58.1/reference/destructors.html#temporary-lifetime-extension
// for more info.
- $crate::pin::Pin::<&mut _> { pointer: &mut { $value } }
+ $crate::pin::Pin::<&mut _> { __pointer: &mut { $value } }
}
diff --git a/src/etc/natvis/libcore.natvis b/src/etc/natvis/libcore.natvis
index 624d8cc5cc5..f8569ef2594 100644
--- a/src/etc/natvis/libcore.natvis
+++ b/src/etc/natvis/libcore.natvis
@@ -99,9 +99,9 @@
</Type>
<Type Name="core::pin::Pin<*>">
- <DisplayString>Pin({(void*)pointer}: {pointer})</DisplayString>
+ <DisplayString>Pin({(void*)__pointer}: {__pointer})</DisplayString>
<Expand>
- <ExpandedItem>pointer</ExpandedItem>
+ <ExpandedItem>__pointer</ExpandedItem>
</Expand>
</Type>
diff --git a/tests/mir-opt/inline/inline_coroutine.main.Inline.panic-abort.diff b/tests/mir-opt/inline/inline_coroutine.main.Inline.panic-abort.diff
index 8e53427e7e0..a38b8246bde 100644
--- a/tests/mir-opt/inline/inline_coroutine.main.Inline.panic-abort.diff
+++ b/tests/mir-opt/inline/inline_coroutine.main.Inline.panic-abort.diff
@@ -36,7 +36,7 @@
- _4 = g() -> [return: bb1, unwind unreachable];
+ _4 = {coroutine@$DIR/inline_coroutine.rs:19:5: 19:8 (#0)};
+ _3 = &mut _4;
-+ _2 = Pin::<&mut {coroutine@$DIR/inline_coroutine.rs:19:5: 19:8}> { pointer: _3 };
++ _2 = Pin::<&mut {coroutine@$DIR/inline_coroutine.rs:19:5: 19:8}> { __pointer: _3 };
+ StorageDead(_3);
+ StorageLive(_5);
+ _5 = const false;
diff --git a/tests/mir-opt/inline/inline_coroutine.main.Inline.panic-unwind.diff b/tests/mir-opt/inline/inline_coroutine.main.Inline.panic-unwind.diff
index b06db41af9d..dc6628ab44c 100644
--- a/tests/mir-opt/inline/inline_coroutine.main.Inline.panic-unwind.diff
+++ b/tests/mir-opt/inline/inline_coroutine.main.Inline.panic-unwind.diff
@@ -36,7 +36,7 @@
- _4 = g() -> [return: bb1, unwind continue];
+ _4 = {coroutine@$DIR/inline_coroutine.rs:19:5: 19:8 (#0)};
+ _3 = &mut _4;
-+ _2 = Pin::<&mut {coroutine@$DIR/inline_coroutine.rs:19:5: 19:8}> { pointer: _3 };
++ _2 = Pin::<&mut {coroutine@$DIR/inline_coroutine.rs:19:5: 19:8}> { __pointer: _3 };
+ StorageDead(_3);
+ StorageLive(_5);
+ _5 = const false;
diff --git a/tests/ui/feature-gates/feature-gate-unsafe_pin_internals.rs b/tests/ui/feature-gates/feature-gate-unsafe_pin_internals.rs
index 134ea25b75a..594a2672d43 100644
--- a/tests/ui/feature-gates/feature-gate-unsafe_pin_internals.rs
+++ b/tests/ui/feature-gates/feature-gate-unsafe_pin_internals.rs
@@ -7,7 +7,7 @@ use core::{marker::PhantomPinned, pin::Pin};
/// The `unsafe_pin_internals` is indeed unsound.
fn non_unsafe_pin_new_unchecked<T>(pointer: &mut T) -> Pin<&mut T> {
- Pin { pointer }
+ Pin { __pointer: pointer }
}
fn main() {
diff --git a/tests/ui/pin-macro/cant_access_internals.rs b/tests/ui/pin-macro/cant_access_internals.rs
index 5826a18b571..4aeb6a643d9 100644
--- a/tests/ui/pin-macro/cant_access_internals.rs
+++ b/tests/ui/pin-macro/cant_access_internals.rs
@@ -8,5 +8,5 @@ use core::{
fn main() {
let mut phantom_pinned = pin!(PhantomPinned);
- mem::take(phantom_pinned.pointer); //~ ERROR use of unstable library feature 'unsafe_pin_internals'
+ mem::take(phantom_pinned.__pointer); //~ ERROR use of unstable library feature 'unsafe_pin_internals'
}
diff --git a/tests/ui/pin-macro/cant_access_internals.stderr b/tests/ui/pin-macro/cant_access_internals.stderr
index 2737b84f599..444314a9d8b 100644
--- a/tests/ui/pin-macro/cant_access_internals.stderr
+++ b/tests/ui/pin-macro/cant_access_internals.stderr
@@ -1,8 +1,8 @@
error[E0658]: use of unstable library feature 'unsafe_pin_internals'
--> $DIR/cant_access_internals.rs:11:15
|
-LL | mem::take(phantom_pinned.pointer);
- | ^^^^^^^^^^^^^^^^^^^^^^
+LL | mem::take(phantom_pinned.__pointer);
+ | ^^^^^^^^^^^^^^^^^^^^^^^^
|
= help: add `#![feature(unsafe_pin_internals)]` to the crate attributes to enable
= note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date