Auto merge of #130631 - GuillaumeGomez:rollup-jpgy1iv, r=GuillaumeGomez

Rollup of 7 pull requests

Successful merges:

 - #128209 (Remove macOS 10.10 dynamic linker bug workaround)
 - #130526 (Begin experimental support for pin reborrowing)
 - #130611 (Address diagnostics regression for `const_char_encode_utf8`.)
 - #130614 (Add arm64e-apple-tvos target)
 - #130617 (bail if there are too many non-region infer vars in the query response)
 - #130619 (Fix scraped examples height)
 - #130624 (Add `Vec::as_non_null`)

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

compiler/rustc_borrowck/messages.ftl

@@ -207,7 +207,7 @@ borrowck_simd_intrinsic_arg_const =
         *[other] {$arg}th
     } argument of `{$intrinsic}` is required to be a `const` item
 
-borrowck_suggest_create_freash_reborrow =
+borrowck_suggest_create_fresh_reborrow =
     consider reborrowing the `Pin` instead of moving it
 
 borrowck_suggest_iterate_over_slice =

compiler/rustc_borrowck/src/session_diagnostics.rs

@@ -415,7 +415,7 @@ pub(crate) enum CaptureReasonSuggest<'tcx> {
         span: Span,
     },
     #[suggestion(
-        borrowck_suggest_create_freash_reborrow,
+        borrowck_suggest_create_fresh_reborrow,
         applicability = "maybe-incorrect",
         code = ".as_mut()",
         style = "verbose"

compiler/rustc_codegen_llvm/src/consts.rs

@@ -443,58 +443,6 @@ impl<'ll> CodegenCx<'ll, '_> {
 
             if attrs.flags.contains(CodegenFnAttrFlags::THREAD_LOCAL) {
                 llvm::set_thread_local_mode(g, self.tls_model);
-
-                // Do not allow LLVM to change the alignment of a TLS on macOS.
-                //
-                // By default a global's alignment can be freely increased.
-                // This allows LLVM to generate more performant instructions
-                // e.g., using load-aligned into a SIMD register.
-                //
-                // However, on macOS 10.10 or below, the dynamic linker does not
-                // respect any alignment given on the TLS (radar 24221680).
-                // This will violate the alignment assumption, and causing segfault at runtime.
-                //
-                // This bug is very easy to trigger. In `println!` and `panic!`,
-                // the `LOCAL_STDOUT`/`LOCAL_STDERR` handles are stored in a TLS,
-                // which the values would be `mem::replace`d on initialization.
-                // The implementation of `mem::replace` will use SIMD
-                // whenever the size is 32 bytes or higher. LLVM notices SIMD is used
-                // and tries to align `LOCAL_STDOUT`/`LOCAL_STDERR` to a 32-byte boundary,
-                // which macOS's dyld disregarded and causing crashes
-                // (see issues #51794, #51758, #50867, #48866 and #44056).
-                //
-                // To workaround the bug, we trick LLVM into not increasing
-                // the global's alignment by explicitly assigning a section to it
-                // (equivalent to automatically generating a `#[link_section]` attribute).
-                // See the comment in the `GlobalValue::canIncreaseAlignment()` function
-                // of `lib/IR/Globals.cpp` for why this works.
-                //
-                // When the alignment is not increased, the optimized `mem::replace`
-                // will use load-unaligned instructions instead, and thus avoiding the crash.
-                //
-                // We could remove this hack whenever we decide to drop macOS 10.10 support.
-                if self.tcx.sess.target.is_like_osx {
-                    // The `inspect` method is okay here because we checked for provenance, and
-                    // because we are doing this access to inspect the final interpreter state
-                    // (not as part of the interpreter execution).
-                    //
-                    // FIXME: This check requires that the (arbitrary) value of undefined bytes
-                    // happens to be zero. Instead, we should only check the value of defined bytes
-                    // and set all undefined bytes to zero if this allocation is headed for the
-                    // BSS.
-                    let all_bytes_are_zero = alloc.provenance().ptrs().is_empty()
-                        && alloc
-                            .inspect_with_uninit_and_ptr_outside_interpreter(0..alloc.len())
-                            .iter()
-                            .all(|&byte| byte == 0);
-
-                    let sect_name = if all_bytes_are_zero {
-                        c"__DATA,__thread_bss"
-                    } else {
-                        c"__DATA,__thread_data"
-                    };
-                    llvm::LLVMSetSection(g, sect_name.as_ptr());
-                }
             }
 
             // Wasm statics with custom link sections get special treatment as they

compiler/rustc_feature/src/unstable.rs

@@ -558,6 +558,8 @@ declare_features! (
     (unstable, optimize_attribute, "1.34.0", Some(54882)),
     /// Allows specifying nop padding on functions for dynamic patching.
     (unstable, patchable_function_entry, "1.81.0", Some(123115)),
+    /// Experimental features that make `Pin` more ergonomic.
+    (incomplete, pin_ergonomics, "CURRENT_RUSTC_VERSION", Some(130494)),
     /// Allows postfix match `expr.match { ... }`
     (unstable, postfix_match, "1.79.0", Some(121618)),
     /// Allows macro attributes on expressions, statements and non-inline modules.

compiler/rustc_hir_typeck/src/coercion.rs

@@ -214,6 +214,12 @@ impl<'f, 'tcx> Coerce<'f, 'tcx> {
             ty::Dynamic(predicates, region, ty::DynStar) if self.tcx.features().dyn_star => {
                 return self.coerce_dyn_star(a, b, predicates, region);
             }
+            ty::Adt(pin, _)
+                if self.tcx.features().pin_ergonomics
+                    && self.tcx.is_lang_item(pin.did(), hir::LangItem::Pin) =>
+            {
+                return self.coerce_pin(a, b);
+            }
             _ => {}
         }
 
@@ -774,6 +780,62 @@ impl<'f, 'tcx> Coerce<'f, 'tcx> {
         })
     }
 
+    /// Applies reborrowing for `Pin`
+    ///
+    /// We currently only support reborrowing `Pin<&mut T>` as `Pin<&mut T>`. This is accomplished
+    /// by inserting a call to `Pin::as_mut` during MIR building.
+    ///
+    /// In the future we might want to support other reborrowing coercions, such as:
+    /// - `Pin<&mut T>` as `Pin<&T>`
+    /// - `Pin<&T>` as `Pin<&T>`
+    /// - `Pin<Box<T>>` as `Pin<&T>`
+    /// - `Pin<Box<T>>` as `Pin<&mut T>`
+    #[instrument(skip(self), level = "trace")]
+    fn coerce_pin(&self, a: Ty<'tcx>, b: Ty<'tcx>) -> CoerceResult<'tcx> {
+        // We need to make sure the two types are compatible for coercion.
+        // Then we will build a ReborrowPin adjustment and return that as an InferOk.
+
+        // Right now we can only reborrow if this is a `Pin<&mut T>`.
+        let extract_pin_mut = |ty: Ty<'tcx>| {
+            // Get the T out of Pin<T>
+            let (pin, ty) = match ty.kind() {
+                ty::Adt(pin, args) if self.tcx.is_lang_item(pin.did(), hir::LangItem::Pin) => {
+                    (*pin, args[0].expect_ty())
+                }
+                _ => {
+                    debug!("can't reborrow {:?} as pinned", ty);
+                    return Err(TypeError::Mismatch);
+                }
+            };
+            // Make sure the T is something we understand (just `&mut U` for now)
+            match ty.kind() {
+                ty::Ref(region, ty, mutbl) => Ok((pin, *region, *ty, *mutbl)),
+                _ => {
+                    debug!("can't reborrow pin of inner type {:?}", ty);
+                    Err(TypeError::Mismatch)
+                }
+            }
+        };
+
+        let (pin, a_region, a_ty, mut_a) = extract_pin_mut(a)?;
+        let (_, b_region, _b_ty, mut_b) = extract_pin_mut(b)?;
+
+        coerce_mutbls(mut_a, mut_b)?;
+
+        // update a with b's mutability since we'll be coercing mutability
+        let a = Ty::new_adt(
+            self.tcx,
+            pin,
+            self.tcx.mk_args(&[Ty::new_ref(self.tcx, a_region, a_ty, mut_b).into()]),
+        );
+
+        // To complete the reborrow, we need to make sure we can unify the inner types, and if so we
+        // add the adjustments.
+        self.unify_and(a, b, |_inner_ty| {
+            vec![Adjustment { kind: Adjust::ReborrowPin(b_region, mut_b), target: b }]
+        })
+    }
+
     fn coerce_from_safe_fn<F, G>(
         &self,
         a: Ty<'tcx>,

compiler/rustc_hir_typeck/src/expr_use_visitor.rs

@@ -780,6 +780,16 @@ impl<'tcx, Cx: TypeInformationCtxt<'tcx>, D: Delegate<'tcx>> ExprUseVisitor<'tcx
                 adjustment::Adjust::Borrow(ref autoref) => {
                     self.walk_autoref(expr, &place_with_id, autoref);
                 }
+
+                adjustment::Adjust::ReborrowPin(_, mutbl) => {
+                    // Reborrowing a Pin is like a combinations of a deref and a borrow, so we do
+                    // both.
+                    let bk = match mutbl {
+                        ty::Mutability::Not => ty::BorrowKind::ImmBorrow,
+                        ty::Mutability::Mut => ty::BorrowKind::MutBorrow,
+                    };
+                    self.delegate.borrow_mut().borrow(&place_with_id, place_with_id.hir_id, bk);
+                }
             }
             place_with_id = self.cat_expr_adjusted(expr, place_with_id, adjustment)?;
         }
@@ -1284,6 +1294,7 @@ impl<'tcx, Cx: TypeInformationCtxt<'tcx>, D: Delegate<'tcx>> ExprUseVisitor<'tcx
             adjustment::Adjust::NeverToAny
             | adjustment::Adjust::Pointer(_)
             | adjustment::Adjust::Borrow(_)
+            | adjustment::Adjust::ReborrowPin(..)
             | adjustment::Adjust::DynStar => {
                 // Result is an rvalue.
                 Ok(self.cat_rvalue(expr.hir_id, target))

compiler/rustc_middle/src/ty/adjustment.rs

@@ -104,6 +104,9 @@ pub enum Adjust<'tcx> {
 
     /// Cast into a dyn* object.
     DynStar,
+
+    /// Take a pinned reference and reborrow as a `Pin<&mut T>` or `Pin<&T>`.
+    ReborrowPin(ty::Region<'tcx>, hir::Mutability),
 }
 
 /// An overloaded autoderef step, representing a `Deref(Mut)::deref(_mut)`

compiler/rustc_mir_build/src/thir/cx/expr.rs

@@ -74,6 +74,7 @@ impl<'tcx> Cx<'tcx> {
         self.thir.exprs.push(expr)
     }
 
+    #[instrument(level = "trace", skip(self, expr, span))]
     fn apply_adjustment(
         &mut self,
         hir_expr: &'tcx hir::Expr<'tcx>,
@@ -146,6 +147,67 @@ impl<'tcx> Cx<'tcx> {
                 ExprKind::RawBorrow { mutability, arg: self.thir.exprs.push(expr) }
             }
             Adjust::DynStar => ExprKind::Cast { source: self.thir.exprs.push(expr) },
+            Adjust::ReborrowPin(region, mutbl) => {
+                debug!("apply ReborrowPin adjustment");
+                // Rewrite `$expr` as `Pin { __pointer: &(mut)? *($expr).__pointer }`
+
+                // We'll need these types later on
+                let pin_ty_args = match expr.ty.kind() {
+                    ty::Adt(_, args) => args,
+                    _ => bug!("ReborrowPin with non-Pin type"),
+                };
+                let pin_ty = pin_ty_args.iter().next().unwrap().expect_ty();
+                let ptr_target_ty = match pin_ty.kind() {
+                    ty::Ref(_, ty, _) => *ty,
+                    _ => bug!("ReborrowPin with non-Ref type"),
+                };
+
+                // pointer = ($expr).__pointer
+                let pointer_target = ExprKind::Field {
+                    lhs: self.thir.exprs.push(expr),
+                    variant_index: FIRST_VARIANT,
+                    name: FieldIdx::from(0u32),
+                };
+                let arg = Expr { temp_lifetime, ty: pin_ty, span, kind: pointer_target };
+                let arg = self.thir.exprs.push(arg);
+
+                // arg = *pointer
+                let expr = ExprKind::Deref { arg };
+                let arg = self.thir.exprs.push(Expr {
+                    temp_lifetime,
+                    ty: ptr_target_ty,
+                    span,
+                    kind: expr,
+                });
+
+                // expr = &mut target
+                let borrow_kind = match mutbl {
+                    hir::Mutability::Mut => BorrowKind::Mut { kind: mir::MutBorrowKind::Default },
+                    hir::Mutability::Not => BorrowKind::Shared,
+                };
+                let new_pin_target = Ty::new_ref(self.tcx, region, ptr_target_ty, mutbl);
+                let expr = self.thir.exprs.push(Expr {
+                    temp_lifetime,
+                    ty: new_pin_target,
+                    span,
+                    kind: ExprKind::Borrow { borrow_kind, arg },
+                });
+
+                // kind = Pin { __pointer: pointer }
+                let pin_did = self.tcx.require_lang_item(rustc_hir::LangItem::Pin, Some(span));
+                let args = self.tcx.mk_args(&[new_pin_target.into()]);
+                let kind = ExprKind::Adt(Box::new(AdtExpr {
+                    adt_def: self.tcx.adt_def(pin_did),
+                    variant_index: FIRST_VARIANT,
+                    args,
+                    fields: Box::new([FieldExpr { name: FieldIdx::from(0u32), expr }]),
+                    user_ty: None,
+                    base: None,
+                }));
+
+                debug!(?kind);
+                kind
+            }
         };
 
         Expr { temp_lifetime, ty: adjustment.target, span, kind }
@@ -1014,7 +1076,7 @@ impl<'tcx> Cx<'tcx> {
 
         // Reconstruct the output assuming it's a reference with the
         // same region and mutability as the receiver. This holds for
-        // `Deref(Mut)::Deref(_mut)` and `Index(Mut)::index(_mut)`.
+        // `Deref(Mut)::deref(_mut)` and `Index(Mut)::index(_mut)`.
         let ty::Ref(region, _, mutbl) = *self.thir[args[0]].ty.kind() else {
             span_bug!(span, "overloaded_place: receiver is not a reference");
         };

compiler/rustc_next_trait_solver/src/solve/eval_ctxt/canonical.rs

@@ -157,6 +157,17 @@ where
             },
         );
 
+        // HACK: We bail with overflow if the response would have too many non-region
+        // inference variables. This tends to only happen if we encounter a lot of
+        // ambiguous alias types which get replaced with fresh inference variables
+        // during generalization. This prevents a hang in nalgebra.
+        let num_non_region_vars = canonical.variables.iter().filter(|c| !c.is_region()).count();
+        if num_non_region_vars > self.cx().recursion_limit() {
+            return Ok(self.make_ambiguous_response_no_constraints(MaybeCause::Overflow {
+                suggest_increasing_limit: true,
+            }));
+        }
+
         Ok(canonical)
     }
 

compiler/rustc_span/src/symbol.rs

@@ -1453,6 +1453,7 @@ symbols! {
         pic,
         pie,
         pin,
+        pin_ergonomics,
         platform_intrinsics,
         plugin,
         plugin_registrar,

compiler/rustc_target/src/spec/mod.rs

@@ -1714,8 +1714,10 @@ supported_targets! {
     ("x86_64-apple-ios-macabi", x86_64_apple_ios_macabi),
     ("aarch64-apple-ios-macabi", aarch64_apple_ios_macabi),
     ("aarch64-apple-ios-sim", aarch64_apple_ios_sim),
+
     ("aarch64-apple-tvos", aarch64_apple_tvos),
     ("aarch64-apple-tvos-sim", aarch64_apple_tvos_sim),
+    ("arm64e-apple-tvos", arm64e_apple_tvos),
     ("x86_64-apple-tvos", x86_64_apple_tvos),
 
     ("armv7k-apple-watchos", armv7k_apple_watchos),

compiler/rustc_target/src/spec/targets/arm64e_apple_tvos.rs

@@ -0,0 +1,24 @@
+use crate::spec::base::apple::{base, Arch, TargetAbi};
+use crate::spec::{FramePointer, Target, TargetOptions};
+
+pub(crate) fn target() -> Target {
+    let (opts, llvm_target, arch) = base("tvos", Arch::Arm64e, TargetAbi::Normal);
+    Target {
+        llvm_target,
+        metadata: crate::spec::TargetMetadata {
+            description: Some("ARM64e Apple tvOS".into()),
+            tier: Some(3),
+            host_tools: Some(false),
+            std: Some(true),
+        },
+        pointer_width: 64,
+        data_layout: "e-m:o-i64:64-i128:128-n32:64-S128-Fn32".into(),
+        arch,
+        options: TargetOptions {
+            features: "+neon,+fp-armv8,+apple-a12,+v8.3a,+pauth".into(),
+            max_atomic_width: Some(128),
+            frame_pointer: FramePointer::NonLeaf,
+            ..opts
+        },
+    }
+}

library/alloc/src/vec/mod.rs

@@ -1584,7 +1584,8 @@ impl<T, A: Allocator> Vec<T, A> {
     ///
     /// This method guarantees that for the purpose of the aliasing model, this method
     /// does not materialize a reference to the underlying slice, and thus the returned pointer
-    /// will remain valid when mixed with other calls to [`as_ptr`] and [`as_mut_ptr`].
+    /// will remain valid when mixed with other calls to [`as_ptr`], [`as_mut_ptr`],
+    /// and [`as_non_null`].
     /// Note that calling other methods that materialize mutable references to the slice,
     /// or mutable references to specific elements you are planning on accessing through this pointer,
     /// as well as writing to those elements, may still invalidate this pointer.
@@ -1621,6 +1622,7 @@ impl<T, A: Allocator> Vec<T, A> {
     ///
     /// [`as_mut_ptr`]: Vec::as_mut_ptr
     /// [`as_ptr`]: Vec::as_ptr
+    /// [`as_non_null`]: Vec::as_non_null
     #[stable(feature = "vec_as_ptr", since = "1.37.0")]
     #[rustc_never_returns_null_ptr]
     #[inline]
@@ -1640,7 +1642,8 @@ impl<T, A: Allocator> Vec<T, A> {
     ///
     /// This method guarantees that for the purpose of the aliasing model, this method
     /// does not materialize a reference to the underlying slice, and thus the returned pointer
-    /// will remain valid when mixed with other calls to [`as_ptr`] and [`as_mut_ptr`].
+    /// will remain valid when mixed with other calls to [`as_ptr`], [`as_mut_ptr`],
+    /// and [`as_non_null`].
     /// Note that calling other methods that materialize references to the slice,
     /// or references to specific elements you are planning on accessing through this pointer,
     /// may still invalidate this pointer.
@@ -1680,6 +1683,7 @@ impl<T, A: Allocator> Vec<T, A> {
     ///
     /// [`as_mut_ptr`]: Vec::as_mut_ptr
     /// [`as_ptr`]: Vec::as_ptr
+    /// [`as_non_null`]: Vec::as_non_null
     #[stable(feature = "vec_as_ptr", since = "1.37.0")]
     #[rustc_never_returns_null_ptr]
     #[inline]
@@ -1689,6 +1693,69 @@ impl<T, A: Allocator> Vec<T, A> {
         self.buf.ptr()
     }
 
+    /// Returns a `NonNull` pointer to the vector's buffer, or a dangling
+    /// `NonNull` pointer valid for zero sized reads if the vector didn't allocate.
+    ///
+    /// The caller must ensure that the vector outlives the pointer this
+    /// function returns, or else it will end up dangling.
+    /// Modifying the vector may cause its buffer to be reallocated,
+    /// which would also make any pointers to it invalid.
+    ///
+    /// This method guarantees that for the purpose of the aliasing model, this method
+    /// does not materialize a reference to the underlying slice, and thus the returned pointer
+    /// will remain valid when mixed with other calls to [`as_ptr`], [`as_mut_ptr`],
+    /// and [`as_non_null`].
+    /// Note that calling other methods that materialize references to the slice,
+    /// or references to specific elements you are planning on accessing through this pointer,
+    /// may still invalidate this pointer.
+    /// See the second example below for how this guarantee can be used.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(box_vec_non_null)]
+    ///
+    /// // Allocate vector big enough for 4 elements.
+    /// let size = 4;
+    /// let mut x: Vec<i32> = Vec::with_capacity(size);
+    /// let x_ptr = x.as_non_null();
+    ///
+    /// // Initialize elements via raw pointer writes, then set length.
+    /// unsafe {
+    ///     for i in 0..size {
+    ///         x_ptr.add(i).write(i as i32);
+    ///     }
+    ///     x.set_len(size);
+    /// }
+    /// assert_eq!(&*x, &[0, 1, 2, 3]);
+    /// ```
+    ///
+    /// Due to the aliasing guarantee, the following code is legal:
+    ///
+    /// ```rust
+    /// #![feature(box_vec_non_null)]
+    ///
+    /// unsafe {
+    ///     let mut v = vec![0];
+    ///     let ptr1 = v.as_non_null();
+    ///     ptr1.write(1);
+    ///     let ptr2 = v.as_non_null();
+    ///     ptr2.write(2);
+    ///     // Notably, the write to `ptr2` did *not* invalidate `ptr1`:
+    ///     ptr1.write(3);
+    /// }
+    /// ```
+    ///
+    /// [`as_mut_ptr`]: Vec::as_mut_ptr
+    /// [`as_ptr`]: Vec::as_ptr
+    /// [`as_non_null`]: Vec::as_non_null
+    #[unstable(feature = "box_vec_non_null", reason = "new API", issue = "130364")]
+    #[inline]
+    pub fn as_non_null(&mut self) -> NonNull<T> {
+        // SAFETY: A `Vec` always has a non-null pointer.
+        unsafe { NonNull::new_unchecked(self.as_mut_ptr()) }
+    }
+
     /// Returns a reference to the underlying allocator.
     #[unstable(feature = "allocator_api", issue = "32838")]
     #[inline]

library/core/src/char/methods.rs

@@ -1,6 +1,7 @@
 //! impl char {}
 
 use super::*;
+use crate::intrinsics::const_eval_select;
 use crate::slice;
 use crate::str::from_utf8_unchecked_mut;
 use crate::unicode::printable::is_printable;
@@ -1762,6 +1763,15 @@ const fn len_utf8(code: u32) -> usize {
 #[doc(hidden)]
 #[inline]
 pub const fn encode_utf8_raw(code: u32, dst: &mut [u8]) -> &mut [u8] {
+    const fn panic_at_const(_code: u32, _len: usize, _dst_len: usize) {
+        // Note that we cannot format in constant expressions.
+        panic!("encode_utf8: buffer does not have enough bytes to encode code point");
+    }
+    fn panic_at_rt(code: u32, len: usize, dst_len: usize) {
+        panic!(
+            "encode_utf8: need {len} bytes to encode U+{code:04X} but buffer has just {dst_len}",
+        );
+    }
     let len = len_utf8(code);
     match (len, &mut *dst) {
         (1, [a, ..]) => {
@@ -1782,8 +1792,8 @@ pub const fn encode_utf8_raw(code: u32, dst: &mut [u8]) -> &mut [u8] {
             *c = (code >> 6 & 0x3F) as u8 | TAG_CONT;
             *d = (code & 0x3F) as u8 | TAG_CONT;
         }
-        // Note that we cannot format in constant expressions.
+        // FIXME(const-hack): We would prefer to have streamlined panics when formatters become const-friendly.
-        _ => panic!("encode_utf8: buffer does not have enough bytes to encode code point"),
+        _ => const_eval_select((code, len, dst.len()), panic_at_const, panic_at_rt),
     };
     // SAFETY: `<&mut [u8]>::as_mut_ptr` is guaranteed to return a valid pointer and `len` has been tested to be within bounds.
     unsafe { slice::from_raw_parts_mut(dst.as_mut_ptr(), len) }

library/std/src/fs.rs

@@ -2473,16 +2473,15 @@ pub fn remove_dir<P: AsRef<Path>>(path: P) -> io::Result<()> {
 /// # Platform-specific behavior
 ///
 /// This function currently corresponds to `openat`, `fdopendir`, `unlinkat` and `lstat` functions
-/// on Unix (except for macOS before version 10.10 and REDOX) and the `CreateFileW`,
+/// on Unix (except for REDOX) and the `CreateFileW`, `GetFileInformationByHandleEx`,
-/// `GetFileInformationByHandleEx`, `SetFileInformationByHandle`, and `NtCreateFile` functions on
+/// `SetFileInformationByHandle`, and `NtCreateFile` functions on Windows. Note that, this
-/// Windows. Note that, this [may change in the future][changes].
+/// [may change in the future][changes].
 ///
 /// [changes]: io#platform-specific-behavior
 ///
-/// On macOS before version 10.10 and REDOX, as well as when running in Miri for any target, this
+/// On REDOX, as well as when running in Miri for any target, this function is not protected against
-/// function is not protected against time-of-check to time-of-use (TOCTOU) race conditions, and
+/// time-of-check to time-of-use (TOCTOU) race conditions, and should not be used in
-/// should not be used in security-sensitive code on those platforms. All other platforms are
+/// security-sensitive code on those platforms. All other platforms are protected.
-/// protected.
 ///
 /// # Errors
 ///

src/doc/rustc/src/SUMMARY.md

@@ -25,6 +25,7 @@
         - [\*-apple-ios-macabi](platform-support/apple-ios-macabi.md)
         - [arm64e-apple-ios](platform-support/arm64e-apple-ios.md)
     - [\*-apple-tvos](platform-support/apple-tvos.md)
+        - [arm64e-apple-tvos](platform-support/arm64e-apple-tvos.md)
     - [\*-apple-watchos](platform-support/apple-watchos.md)
     - [\*-apple-visionos](platform-support/apple-visionos.md)
     - [aarch64-nintendo-switch-freestanding](platform-support/aarch64-nintendo-switch-freestanding.md)

src/doc/rustc/src/platform-support.md

@@ -245,8 +245,9 @@ host tools.
 
 target | std | host | notes
 -------|:---:|:----:|-------
-[`arm64e-apple-ios`](platform-support/arm64e-apple-ios.md) | ✓ | | ARM64e Apple iOS
 [`arm64e-apple-darwin`](platform-support/arm64e-apple-darwin.md)  | ✓ | ✓ | ARM64e Apple Darwin
+[`arm64e-apple-ios`](platform-support/arm64e-apple-ios.md) | ✓ | | ARM64e Apple iOS
+[`arm64e-apple-tvos`](platform-support/arm64e-apple-tvos.md)  | ✓ | | ARM64e Apple tvOS
 [`aarch64-apple-tvos`](platform-support/apple-tvos.md) | ✓ |  | ARM64 tvOS
 [`aarch64-apple-tvos-sim`](platform-support/apple-tvos.md) | ✓ |  | ARM64 tvOS Simulator
 [`aarch64-apple-watchos`](platform-support/apple-watchos.md) | ✓ |  | ARM64 Apple WatchOS

src/doc/rustc/src/platform-support/arm64e-apple-tvos.md

@@ -0,0 +1,37 @@
+# `arm64e-apple-tvos`
+
+**Tier: 3**
+
+ARM64e tvOS (10.0+)
+
+## Target maintainers
+
+- Artyom Tetyukhin ([@arttet](https://github.com/https://github.com/arttet))
+
+## Requirements
+
+This target is cross-compiled and supports `std`.
+To build this target Xcode 12 or higher on macOS is required.
+
+## Building the target
+
+You can build Rust with support for the targets by adding it to the `target` list in `config.toml`:
+
+```toml
+[build]
+target = [ "arm64e-apple-tvos" ]
+```
+
+## Building Rust programs
+
+Rust does not yet ship pre-compiled artifacts for this target.
+To compile for this target, you will need to build Rust with the target enabled (see [Building the target](#building-the-target) above).
+
+## Testing
+
+The target does support running binaries on tvOS platforms with `arm64e` architecture.
+
+## Cross-compilation toolchains and C code
+
+The targets do support `C` code.
+To build compatible `C` code, you have to use XCode with the same compiler and flags.

src/librustdoc/html/static/css/rustdoc.css

@@ -801,6 +801,9 @@ both the code example and the line numbers, so we need to remove the radius in t
 	 * and we include additional 10px for padding. */
 	max-height: calc(1.5em * 5 + 10px);
 }
+.more-scraped-examples .scraped-example:not(.expanded) .example-wrap {
+	max-height: calc(1.5em * 10 + 10px);
+}
 
 .rustdoc:not(.src) .scraped-example:not(.expanded) .src-line-numbers,
 .rustdoc:not(.src) .scraped-example:not(.expanded) .src-line-numbers > pre,
@@ -828,10 +831,14 @@ both the code example and the line numbers, so we need to remove the radius in t
 	-webkit-user-select: none;
 	user-select: none;
 	padding: 14px 8px;
+	padding-right: 2px;
 	color: var(--src-line-numbers-span-color);
 }
 
-.rustdoc .scraped-example .src-line-numbers {
+.rustdoc .scraped-example .example-wrap .src-line-numbers {
+	padding: 0;
+}
+.rustdoc .src-line-numbers pre {
 	padding: 14px 0;
 }
 .src-line-numbers a, .src-line-numbers span {
@@ -890,7 +897,7 @@ both the code example and the line numbers, so we need to remove the radius in t
 }
 
 .docblock code, .docblock-short code,
-pre, .rustdoc.src .example-wrap {
+pre, .rustdoc.src .example-wrap, .example-wrap .src-line-numbers {
 	background-color: var(--code-block-background-color);
 }
 

src/tools/build-manifest/src/main.rs

@@ -51,9 +51,7 @@ static HOSTS: &[&str] = &[
 
 static TARGETS: &[&str] = &[
     "aarch64-apple-darwin",
-    "arm64e-apple-darwin",
     "aarch64-apple-ios",
-    "arm64e-apple-ios",
     "aarch64-apple-ios-macabi",
     "aarch64-apple-ios-sim",
     "aarch64-unknown-fuchsia",
@@ -68,6 +66,9 @@ static TARGETS: &[&str] = &[
     "aarch64-unknown-none-softfloat",
     "aarch64-unknown-redox",
     "aarch64-unknown-uefi",
+    "arm64e-apple-darwin",
+    "arm64e-apple-ios",
+    "arm64e-apple-tvos",
     "arm-linux-androideabi",
     "arm-unknown-linux-gnueabi",
     "arm-unknown-linux-gnueabihf",

tests/assembly/targets/targets-macho.rs

@@ -18,6 +18,9 @@
 //@ revisions: aarch64_apple_tvos_sim
 //@ [aarch64_apple_tvos_sim] compile-flags: --target aarch64-apple-tvos-sim
 //@ [aarch64_apple_tvos_sim] needs-llvm-components: aarch64
+//@ revisions: arm64e_apple_tvos
+//@ [arm64e_apple_tvos] compile-flags: --target arm64e-apple-tvos
+//@ [arm64e_apple_tvos] needs-llvm-components: aarch64
 //@ revisions: aarch64_apple_watchos
 //@ [aarch64_apple_watchos] compile-flags: --target aarch64-apple-watchos
 //@ [aarch64_apple_watchos] needs-llvm-components: aarch64

tests/codegen/issues/issue-44056-macos-tls-align.rs

@@ -1,27 +0,0 @@
-//
-//@ only-apple
-//@ compile-flags: -O
-
-#![crate_type = "rlib"]
-#![feature(thread_local)]
-
-// local_unnamed_addr does not appear when std is built with debug assertions.
-// CHECK: @STATIC_VAR_1 = thread_local {{(local_unnamed_addr )?}}global <{ [32 x i8] }> zeroinitializer, section "__DATA,__thread_bss", align 4
-#[no_mangle]
-#[thread_local]
-static mut STATIC_VAR_1: [u32; 8] = [0; 8];
-
-// CHECK: @STATIC_VAR_2 = thread_local {{(local_unnamed_addr )?}}global <{ [32 x i8] }> <{{[^>]*}}>, section "__DATA,__thread_data", align 4
-#[no_mangle]
-#[thread_local]
-static mut STATIC_VAR_2: [u32; 8] = [4; 8];
-
-#[no_mangle]
-pub unsafe fn f(x: &mut [u32; 8]) {
-    std::mem::swap(x, &mut STATIC_VAR_1)
-}
-
-#[no_mangle]
-pub unsafe fn g(x: &mut [u32; 8]) {
-    std::mem::swap(x, &mut STATIC_VAR_2)
-}

tests/rustdoc-gui/docblock-code-block-line-number.goml

@@ -39,7 +39,10 @@ define-function: (
             {
                 "color": |color|,
                 "margin": "0px",
-                "padding": "14px 8px",
+                "padding-top": "14px",
+                "padding-bottom": "14px",
+                "padding-left": "8px",
+                "padding-right": "2px",
                 "text-align": "right",
                 // There should not be a radius on the right of the line numbers.
                 "border-top-left-radius": "6px",
@@ -141,3 +144,61 @@ assert-css: (
     },
     ALL,
 )
+
+// Checking line numbers on scraped code examples.
+go-to: "file://" + |DOC_PATH| + "/scrape_examples/fn.test_many.html"
+
+define-function: (
+    "check-padding",
+    [path, padding_bottom],
+    block {
+        assert-css: (|path| + " .src-line-numbers", {
+            "padding-top": "0px",
+            "padding-bottom": "0px",
+            "padding-left": "0px",
+            "padding-right": "0px",
+        })
+        assert-css: (|path| + " .src-line-numbers > pre", {
+            "padding-top": "14px",
+            "padding-bottom": |padding_bottom|,
+            "padding-left": "0px",
+            "padding-right": "0px",
+        })
+        assert-css: (|path| + " .src-line-numbers > pre > span", {
+            "padding-top": "0px",
+            "padding-bottom": "0px",
+            "padding-left": "8px",
+            "padding-right": "8px",
+        })
+    },
+)
+
+call-function: ("check-padding", {
+    "path": ".scraped-example .example-wrap",
+    "padding_bottom": "0px",
+})
+
+move-cursor-to: ".scraped-example .example-wrap .rust"
+wait-for: ".scraped-example .example-wrap .button-holder .expand"
+click: ".scraped-example .example-wrap .button-holder .expand"
+wait-for: ".scraped-example.expanded"
+
+call-function: ("check-padding", {
+    "path": ".scraped-example.expanded .example-wrap",
+    "padding_bottom": "14px",
+})
+
+// Now checking the line numbers in the source code page.
+click: ".src"
+assert-css: (".src-line-numbers", {
+    "padding-top": "20px",
+    "padding-bottom": "20px",
+    "padding-left": "4px",
+    "padding-right": "0px",
+})
+assert-css: (".src-line-numbers > a", {
+    "padding-top": "0px",
+    "padding-bottom": "0px",
+    "padding-left": "8px",
+    "padding-right": "8px",
+})

tests/rustdoc-gui/scrape-examples-layout.goml

@@ -37,6 +37,7 @@ assert-property: (
 
 // The "title" should be located at the right bottom corner of the code example.
 store-position: (".scraped-example .example-wrap", {"x": x, "y": y})
+assert-size: (".scraped-example .example-wrap", {"height": 130})
 store-size: (".scraped-example .example-wrap", {"width": width, "height": height})
 store-size: (".scraped-example .scraped-example-title", {
     "width": title_width,
@@ -47,6 +48,13 @@ assert-position: (".scraped-example .scraped-example-title", {
     "y": |y| + |height| - |title_height| - 8,
 })
 
+store-size: (".more-scraped-examples .scraped-example .example-wrap", {"height": more_height})
+assert: |more_height| > |height|
+assert-size: (".more-scraped-examples .scraped-example .example-wrap", {
+    "height": 250,
+    "width": |width|,
+})
+
 // Check that the expand button works and also that line number aligns with code.
 move-cursor-to: ".scraped-example .rust"
 click: ".scraped-example .button-holder .expand"

tests/ui/async-await/pin-reborrow-arg.rs

@@ -0,0 +1,36 @@
+//@ check-pass
+
+#![feature(pin_ergonomics)]
+#![allow(dead_code, incomplete_features)]
+
+use std::pin::Pin;
+
+struct Foo;
+
+impl Foo {
+    fn baz(self: Pin<&mut Self>) {
+    }
+}
+
+fn foo(_: Pin<&mut Foo>) {
+}
+
+fn foo_const(_: Pin<&Foo>) {
+}
+
+fn bar(x: Pin<&mut Foo>) {
+    foo(x);
+    foo(x); // for this to work we need to automatically reborrow,
+            // as if the user had written `foo(x.as_mut())`.
+
+    Foo::baz(x);
+    Foo::baz(x);
+
+    foo_const(x); // make sure we can reborrow &mut as &.
+
+    let x: Pin<&Foo> = Pin::new(&Foo);
+
+    foo_const(x); // make sure reborrowing from & to & works.
+}
+
+fn main() {}

tests/ui/async-await/pin-reborrow-const-as-mut.rs

@@ -0,0 +1,18 @@
+#![feature(pin_ergonomics)]
+#![allow(dead_code, incomplete_features)]
+
+// make sure we can't accidentally reborrow Pin<&T> as Pin<&mut T>
+
+use std::pin::Pin;
+
+struct Foo;
+
+fn foo(_: Pin<&mut Foo>) {
+}
+
+fn bar(x: Pin<&Foo>) {
+    foo(x); //~ ERROR mismatched types
+            //| ERROR types differ in mutability
+}
+
+fn main() {}

tests/ui/async-await/pin-reborrow-const-as-mut.stderr

@@ -0,0 +1,19 @@
+error[E0308]: mismatched types
+  --> $DIR/pin-reborrow-const-as-mut.rs:14:9
+   |
+LL |     foo(x);
+   |     --- ^ types differ in mutability
+   |     |
+   |     arguments to this function are incorrect
+   |
+   = note: expected struct `Pin<&mut Foo>`
+              found struct `Pin<&Foo>`
+note: function defined here
+  --> $DIR/pin-reborrow-const-as-mut.rs:10:4
+   |
+LL | fn foo(_: Pin<&mut Foo>) {
+   |    ^^^ ----------------
+
+error: aborting due to 1 previous error
+
+For more information about this error, try `rustc --explain E0308`.

tests/ui/async-await/pin-reborrow-once.rs

@@ -0,0 +1,13 @@
+#![feature(pin_ergonomics)]
+#![allow(dead_code, incomplete_features)]
+
+// Make sure with pin reborrowing that we can only get one mutable reborrow of a pinned reference.
+
+use std::pin::{pin, Pin};
+
+fn twice(_: Pin<&mut i32>, _: Pin<&mut i32>) {}
+
+fn main() {
+    let x = pin!(42);
+    twice(x, x); //~ ERROR cannot borrow
+}

tests/ui/async-await/pin-reborrow-once.stderr

@@ -0,0 +1,12 @@
+error[E0499]: cannot borrow `*x.__pointer` as mutable more than once at a time
+  --> $DIR/pin-reborrow-once.rs:12:14
+   |
+LL |     twice(x, x);
+   |     ----- -  ^ second mutable borrow occurs here
+   |     |     |
+   |     |     first mutable borrow occurs here
+   |     first borrow later used by call
+
+error: aborting due to 1 previous error
+
+For more information about this error, try `rustc --explain E0499`.

tests/ui/async-await/pin-reborrow-self.rs

@@ -0,0 +1,24 @@
+//@ check-pass
+//@ignore-test
+
+// Currently ignored due to self reborrowing not being implemented for Pin
+
+#![feature(pin_ergonomics)]
+#![allow(incomplete_features)]
+
+use std::pin::Pin;
+
+struct Foo;
+
+impl Foo {
+    fn foo(self: Pin<&mut Self>) {
+    }
+}
+
+fn bar(x: Pin<&mut Foo>) {
+    x.foo();
+    x.foo(); // for this to work we need to automatically reborrow,
+             // as if the user had written `x.as_mut().foo()`.
+}
+
+fn main() {}

tests/ui/async-await/pin-reborrow-shorter.rs

@@ -0,0 +1,14 @@
+//@check-pass
+
+#![feature(pin_ergonomics)]
+#![allow(dead_code, incomplete_features)]
+
+use std::pin::Pin;
+
+fn shorter<'b, T: 'b>(_: Pin<&'b mut T>) {}
+
+fn test<'a: 'b, 'b, T: 'a>(x: Pin<&'a mut T>) {
+    shorter::<'b>(x);
+}
+
+fn main() {}

tests/ui/feature-gates/feature-gate-pin_ergonomics.rs

@@ -0,0 +1,15 @@
+#![allow(dead_code, incomplete_features)]
+
+use std::pin::Pin;
+
+struct Foo;
+
+fn foo(_: Pin<&mut Foo>) {
+}
+
+fn bar(mut x: Pin<&mut Foo>) {
+    foo(x);
+    foo(x); //~ ERROR use of moved value: `x`
+}
+
+fn main() {}

tests/ui/feature-gates/feature-gate-pin_ergonomics.stderr

@@ -0,0 +1,21 @@
+error[E0382]: use of moved value: `x`
+  --> $DIR/feature-gate-pin_ergonomics.rs:12:9
+   |
+LL | fn bar(mut x: Pin<&mut Foo>) {
+   |        ----- move occurs because `x` has type `Pin<&mut Foo>`, which does not implement the `Copy` trait
+LL |     foo(x);
+   |         - value moved here
+LL |     foo(x);
+   |         ^ value used here after move
+   |
+note: consider changing this parameter type in function `foo` to borrow instead if owning the value isn't necessary
+  --> $DIR/feature-gate-pin_ergonomics.rs:7:11
+   |
+LL | fn foo(_: Pin<&mut Foo>) {
+   |    ---    ^^^^^^^^^^^^^ this parameter takes ownership of the value
+   |    |
+   |    in this function
+
+error: aborting due to 1 previous error
+
+For more information about this error, try `rustc --explain E0382`.

tests/ui/traits/coherence-alias-hang.rs

@@ -1,4 +1,6 @@
 //@ check-pass
+//@ revisions: current next
+//[next]@ compile-flags: -Znext-solver
 
 // Regression test for nalgebra hang <https://github.com/rust-lang/rust/issues/130056>.
 

tests/ui/traits/next-solver/cycles/coinduction/fixpoint-exponential-growth.stderr

@@ -4,6 +4,7 @@ error[E0275]: overflow evaluating the requirement `W<_>: Trait`
 LL |     impls::<W<_>>();
    |             ^^^^
    |
+   = help: consider increasing the recursion limit by adding a `#![recursion_limit = "256"]` attribute to your crate (`fixpoint_exponential_growth`)
 note: required by a bound in `impls`
   --> $DIR/fixpoint-exponential-growth.rs:30:13
    |

tests/ui/traits/next-solver/overflow/recursion-limit-zero-issue-115351.rs

@@ -1,6 +1,7 @@
+//~ ERROR overflow evaluating the requirement `Self: Trait`
+//~^ ERROR overflow evaluating the requirement `Self well-formed`
 // This is a non-regression test for issue #115351, where a recursion limit of 0 caused an ICE.
 //@ compile-flags: -Znext-solver --crate-type=lib
-//@ check-pass
 
 #![recursion_limit = "0"]
 trait Trait {}

tests/ui/traits/next-solver/overflow/recursion-limit-zero-issue-115351.stderr

@@ -0,0 +1,11 @@
+error[E0275]: overflow evaluating the requirement `Self: Trait`
+   |
+   = help: consider increasing the recursion limit by adding a `#![recursion_limit = "2"]` attribute to your crate (`recursion_limit_zero_issue_115351`)
+
+error[E0275]: overflow evaluating the requirement `Self well-formed`
+   |
+   = help: consider increasing the recursion limit by adding a `#![recursion_limit = "2"]` attribute to your crate (`recursion_limit_zero_issue_115351`)
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0275`.