Auto merge of rust-lang#129563 - matthiaskrgr:rollup-t6bai2d, r=matthiaskrgr

Rollup of 7 pull requests

Successful merges:

 - rust-lang#129091 (add Box::as_ptr and Box::as_mut_ptr methods)
 - rust-lang#129134 (bootstrap: improve error recovery flags to curl)
 - rust-lang#129416 (library: Move unstable API of new_uninit to new features)
 - rust-lang#129459 (handle stage0 `cargo` and `rustc` separately)
 - rust-lang#129487 (repr_transparent_external_private_fields: special-case some std types)
 - rust-lang#129511 (Update minifier to 0.3.1)
 - rust-lang#129523 (Make `rustc_type_ir` build on stable)

r? `@ghost`
`@rustbot` modify labels: rollup

Author: bors

Diff for: alloc/src/boxed.rs

@@ -293,6 +293,7 @@ impl<T> Box<T> {
     ///
     /// ```
     /// #![feature(new_uninit)]
+    /// #![feature(new_zeroed_alloc)]
     ///
     /// let zero = Box::<u32>::new_zeroed();
     /// let zero = unsafe { zero.assume_init() };
@@ -303,7 +304,7 @@ impl<T> Box<T> {
     /// [zeroed]: mem::MaybeUninit::zeroed
     #[cfg(not(no_global_oom_handling))]
     #[inline]
-    #[unstable(feature = "new_uninit", issue = "63291")]
+    #[unstable(feature = "new_zeroed_alloc", issue = "129396")]
     #[must_use]
     pub fn new_zeroed() -> Box<mem::MaybeUninit<T>> {
         Self::new_zeroed_in(Global)
@@ -684,6 +685,7 @@ impl<T> Box<[T]> {
     /// # Examples
     ///
     /// ```
+    /// #![feature(new_zeroed_alloc)]
     /// #![feature(new_uninit)]
     ///
     /// let values = Box::<[u32]>::new_zeroed_slice(3);
@@ -694,7 +696,7 @@ impl<T> Box<[T]> {
     ///
     /// [zeroed]: mem::MaybeUninit::zeroed
     #[cfg(not(no_global_oom_handling))]
-    #[unstable(feature = "new_uninit", issue = "63291")]
+    #[unstable(feature = "new_zeroed_alloc", issue = "129396")]
     #[must_use]
     pub fn new_zeroed_slice(len: usize) -> Box<[mem::MaybeUninit<T>]> {
         unsafe { RawVec::with_capacity_zeroed(len).into_box(len) }
@@ -955,6 +957,7 @@ impl<T, A: Allocator> Box<mem::MaybeUninit<T>, A> {
     /// # Examples
     ///
     /// ```
+    /// #![feature(box_uninit_write)]
     /// #![feature(new_uninit)]
     ///
     /// let big_box = Box::<[usize; 1024]>::new_uninit();
@@ -972,7 +975,7 @@ impl<T, A: Allocator> Box<mem::MaybeUninit<T>, A> {
     ///     assert_eq!(*x, i);
     /// }
     /// ```
-    #[unstable(feature = "new_uninit", issue = "63291")]
+    #[unstable(feature = "box_uninit_write", issue = "129397")]
     #[inline]
     pub fn write(mut boxed: Self, value: T) -> Box<T, A> {
         unsafe {
@@ -1254,6 +1257,95 @@ impl<T: ?Sized, A: Allocator> Box<T, A> {
         unsafe { (Unique::from(&mut *ptr), alloc) }
     }
 
+    /// Returns a raw mutable pointer to the `Box`'s contents.
+    ///
+    /// The caller must ensure that the `Box` outlives the pointer this
+    /// function returns, or else it will end up dangling.
+    ///
+    /// This method guarantees that for the purpose of the aliasing model, this method
+    /// does not materialize a reference to the underlying memory, and thus the returned pointer
+    /// will remain valid when mixed with other calls to [`as_ptr`] and [`as_mut_ptr`].
+    /// Note that calling other methods that materialize references to the memory
+    /// may still invalidate this pointer.
+    /// See the example below for how this guarantee can be used.
+    ///
+    /// # Examples
+    ///
+    /// Due to the aliasing guarantee, the following code is legal:
+    ///
+    /// ```rust
+    /// #![feature(box_as_ptr)]
+    ///
+    /// unsafe {
+    ///     let mut b = Box::new(0);
+    ///     let ptr1 = Box::as_mut_ptr(&mut b);
+    ///     ptr1.write(1);
+    ///     let ptr2 = Box::as_mut_ptr(&mut b);
+    ///     ptr2.write(2);
+    ///     // Notably, the write to `ptr2` did *not* invalidate `ptr1`:
+    ///     ptr1.write(3);
+    /// }
+    /// ```
+    ///
+    /// [`as_mut_ptr`]: Self::as_mut_ptr
+    /// [`as_ptr`]: Self::as_ptr
+    #[unstable(feature = "box_as_ptr", issue = "129090")]
+    #[rustc_never_returns_null_ptr]
+    #[inline]
+    pub fn as_mut_ptr(b: &mut Self) -> *mut T {
+        // This is a primitive deref, not going through `DerefMut`, and therefore not materializing
+        // any references.
+        ptr::addr_of_mut!(**b)
+    }
+
+    /// Returns a raw pointer to the `Box`'s contents.
+    ///
+    /// The caller must ensure that the `Box` outlives the pointer this
+    /// function returns, or else it will end up dangling.
+    ///
+    /// The caller must also ensure that the memory the pointer (non-transitively) points to
+    /// is never written to (except inside an `UnsafeCell`) using this pointer or any pointer
+    /// derived from it. If you need to mutate the contents of the `Box`, use [`as_mut_ptr`].
+    ///
+    /// This method guarantees that for the purpose of the aliasing model, this method
+    /// does not materialize a reference to the underlying memory, and thus the returned pointer
+    /// will remain valid when mixed with other calls to [`as_ptr`] and [`as_mut_ptr`].
+    /// Note that calling other methods that materialize mutable references to the memory,
+    /// as well as writing to this memory, may still invalidate this pointer.
+    /// See the example below for how this guarantee can be used.
+    ///
+    /// # Examples
+    ///
+    /// Due to the aliasing guarantee, the following code is legal:
+    ///
+    /// ```rust
+    /// #![feature(box_as_ptr)]
+    ///
+    /// unsafe {
+    ///     let mut v = Box::new(0);
+    ///     let ptr1 = Box::as_ptr(&v);
+    ///     let ptr2 = Box::as_mut_ptr(&mut v);
+    ///     let _val = ptr2.read();
+    ///     // No write to this memory has happened yet, so `ptr1` is still valid.
+    ///     let _val = ptr1.read();
+    ///     // However, once we do a write...
+    ///     ptr2.write(1);
+    ///     // ... `ptr1` is no longer valid.
+    ///     // This would be UB: let _val = ptr1.read();
+    /// }
+    /// ```
+    ///
+    /// [`as_mut_ptr`]: Self::as_mut_ptr
+    /// [`as_ptr`]: Self::as_ptr
+    #[unstable(feature = "box_as_ptr", issue = "129090")]
+    #[rustc_never_returns_null_ptr]
+    #[inline]
+    pub fn as_ptr(b: &Self) -> *const T {
+        // This is a primitive deref, not going through `DerefMut`, and therefore not materializing
+        // any references.
+        ptr::addr_of!(**b)
+    }
+
     /// Returns a reference to the underlying allocator.
     ///
     /// Note: this is an associated function, which means that you have

Diff for: alloc/src/rc.rs

@@ -539,6 +539,7 @@ impl<T> Rc<T> {
     /// # Examples
     ///
     /// ```
+    /// #![feature(new_zeroed_alloc)]
     /// #![feature(new_uninit)]
     ///
     /// use std::rc::Rc;
@@ -551,7 +552,7 @@ impl<T> Rc<T> {
     ///
     /// [zeroed]: mem::MaybeUninit::zeroed
     #[cfg(not(no_global_oom_handling))]
-    #[unstable(feature = "new_uninit", issue = "63291")]
+    #[unstable(feature = "new_zeroed_alloc", issue = "129396")]
     #[must_use]
     pub fn new_zeroed() -> Rc<mem::MaybeUninit<T>> {
         unsafe {
@@ -1000,6 +1001,7 @@ impl<T> Rc<[T]> {
     ///
     /// ```
     /// #![feature(new_uninit)]
+    /// #![feature(new_zeroed_alloc)]
     ///
     /// use std::rc::Rc;
     ///
@@ -1011,7 +1013,7 @@ impl<T> Rc<[T]> {
     ///
     /// [zeroed]: mem::MaybeUninit::zeroed
     #[cfg(not(no_global_oom_handling))]
-    #[unstable(feature = "new_uninit", issue = "63291")]
+    #[unstable(feature = "new_zeroed_alloc", issue = "129396")]
     #[must_use]
     pub fn new_zeroed_slice(len: usize) -> Rc<[mem::MaybeUninit<T>]> {
         unsafe {

Diff for: alloc/src/sync.rs

@@ -542,6 +542,7 @@ impl<T> Arc<T> {
     /// # Examples
     ///
     /// ```
+    /// #![feature(new_zeroed_alloc)]
     /// #![feature(new_uninit)]
     ///
     /// use std::sync::Arc;
@@ -555,7 +556,7 @@ impl<T> Arc<T> {
     /// [zeroed]: mem::MaybeUninit::zeroed
     #[cfg(not(no_global_oom_handling))]
     #[inline]
-    #[unstable(feature = "new_uninit", issue = "63291")]
+    #[unstable(feature = "new_zeroed_alloc", issue = "129396")]
     #[must_use]
     pub fn new_zeroed() -> Arc<mem::MaybeUninit<T>> {
         unsafe {
@@ -1134,6 +1135,7 @@ impl<T> Arc<[T]> {
     /// # Examples
     ///
     /// ```
+    /// #![feature(new_zeroed_alloc)]
     /// #![feature(new_uninit)]
     ///
     /// use std::sync::Arc;
@@ -1147,7 +1149,7 @@ impl<T> Arc<[T]> {
     /// [zeroed]: mem::MaybeUninit::zeroed
     #[cfg(not(no_global_oom_handling))]
     #[inline]
-    #[unstable(feature = "new_uninit", issue = "63291")]
+    #[unstable(feature = "new_zeroed_alloc", issue = "129396")]
     #[must_use]
     pub fn new_zeroed_slice(len: usize) -> Arc<[mem::MaybeUninit<T>]> {
         unsafe {
@@ -1191,7 +1193,7 @@ impl<T, A: Allocator> Arc<[T], A> {
     /// assert_eq!(*values, [1, 2, 3])
     /// ```
     #[cfg(not(no_global_oom_handling))]
-    #[unstable(feature = "new_uninit", issue = "63291")]
+    #[unstable(feature = "allocator_api", issue = "32838")]
     #[inline]
     pub fn new_uninit_slice_in(len: usize, alloc: A) -> Arc<[mem::MaybeUninit<T>], A> {
         unsafe { Arc::from_ptr_in(Arc::allocate_for_slice_in(len, &alloc), alloc) }
@@ -1220,7 +1222,7 @@ impl<T, A: Allocator> Arc<[T], A> {
     ///
     /// [zeroed]: mem::MaybeUninit::zeroed
     #[cfg(not(no_global_oom_handling))]
-    #[unstable(feature = "new_uninit", issue = "63291")]
+    #[unstable(feature = "allocator_api", issue = "32838")]
     #[inline]
     pub fn new_zeroed_slice_in(len: usize, alloc: A) -> Arc<[mem::MaybeUninit<T>], A> {
         unsafe {

Diff for: alloc/src/vec/mod.rs

@@ -1334,7 +1334,7 @@ impl<T, A: Allocator> Vec<T, A> {
         self.buf.ptr()
     }
 
-    /// Returns an unsafe mutable pointer to the vector's buffer, or a dangling
+    /// Returns a raw mutable pointer to the vector's buffer, or a dangling
     /// raw pointer valid for zero sized reads if the vector didn't allocate.
     ///
     /// The caller must ensure that the vector outlives the pointer this
@@ -1350,7 +1350,6 @@ impl<T, A: Allocator> Vec<T, A> {
     /// may still invalidate this pointer.
     /// See the second example below for how this guarantee can be used.
     ///
-    ///
     /// # Examples
     ///
     /// ```

Diff for: core/src/cell.rs

@@ -306,6 +306,7 @@ pub use once::OnceCell;
 /// See the [module-level documentation](self) for more.
 #[stable(feature = "rust1", since = "1.0.0")]
 #[repr(transparent)]
+#[cfg_attr(not(bootstrap), rustc_pub_transparent)]
 pub struct Cell<T: ?Sized> {
     value: UnsafeCell<T>,
 }
@@ -2055,6 +2056,7 @@ impl<T: ?Sized + fmt::Display> fmt::Display for RefMut<'_, T> {
 #[lang = "unsafe_cell"]
 #[stable(feature = "rust1", since = "1.0.0")]
 #[repr(transparent)]
+#[cfg_attr(not(bootstrap), rustc_pub_transparent)]
 pub struct UnsafeCell<T: ?Sized> {
     value: T,
 }
@@ -2297,6 +2299,7 @@ impl<T> UnsafeCell<*mut T> {
 /// See [`UnsafeCell`] for details.
 #[unstable(feature = "sync_unsafe_cell", issue = "95439")]
 #[repr(transparent)]
+#[cfg_attr(not(bootstrap), rustc_pub_transparent)]
 pub struct SyncUnsafeCell<T: ?Sized> {
     value: UnsafeCell<T>,
 }

Diff for: core/src/mem/manually_drop.rs

@@ -47,6 +47,7 @@ use crate::ptr;
 #[lang = "manually_drop"]
 #[derive(Copy, Clone, Debug, Default, PartialEq, Eq, PartialOrd, Ord, Hash)]
 #[repr(transparent)]
+#[cfg_attr(not(bootstrap), rustc_pub_transparent)]
 pub struct ManuallyDrop<T: ?Sized> {
     value: T,
 }

Diff for: core/src/mem/maybe_uninit.rs

@@ -237,6 +237,7 @@ use crate::{fmt, intrinsics, ptr, slice};
 #[lang = "maybe_uninit"]
 #[derive(Copy)]
 #[repr(transparent)]
+#[cfg_attr(not(bootstrap), rustc_pub_transparent)]
 pub union MaybeUninit<T> {
     uninit: (),
     value: ManuallyDrop<T>,

Diff for: core/src/pin.rs

@@ -1084,6 +1084,7 @@ use crate::{cmp, fmt};
 #[lang = "pin"]
 #[fundamental]
 #[repr(transparent)]
+#[cfg_attr(not(bootstrap), rustc_pub_transparent)]
 #[derive(Copy, Clone)]
 pub struct Pin<Ptr> {
     // FIXME(#93176): this field is made `#[unstable] #[doc(hidden)] pub` to:

Diff for: std/src/lib.rs

@@ -363,6 +363,7 @@
 #![feature(get_mut_unchecked)]
 #![feature(map_try_insert)]
 #![feature(new_uninit)]
+#![feature(new_zeroed_alloc)]
 #![feature(slice_concat_trait)]
 #![feature(thin_box)]
 #![feature(try_reserve_kind)]