Rollup of 11 pull requests

compiler/rustc_error_codes/src/error_codes/E0658.md

@@ -3,10 +3,7 @@ An unstable feature was used.
 Erroneous code example:
 
 ```compile_fail,E0658
-#[repr(u128)] // error: use of unstable library feature 'repr128'
-enum Foo {
-    Bar(u64),
-}
+use std::intrinsics; // error: use of unstable library feature `core_intrinsics`
 ```
 
 If you're using a stable or a beta version of rustc, you won't be able to use
@@ -17,12 +14,9 @@ If you're using a nightly version of rustc, just add the corresponding feature
 to be able to use it:
 
 ```
-#![feature(repr128)]
+#![feature(core_intrinsics)]
 
-#[repr(u128)] // ok!
-enum Foo {
-    Bar(u64),
-}
+use std::intrinsics; // ok!
 ```
 
 [rustup]: https://rust-lang.github.io/rustup/concepts/channels.html

compiler/rustc_feature/src/accepted.rs

@@ -360,6 +360,8 @@ declare_features! (
     (accepted, relaxed_adts, "1.19.0", Some(35626)),
     /// Lessens the requirements for structs to implement `Unsize`.
     (accepted, relaxed_struct_unsize, "1.58.0", Some(81793)),
+    /// Allows the `#[repr(i128)]` attribute for enums.
+    (accepted, repr128, "CURRENT_RUSTC_VERSION", Some(56071)),
     /// Allows `repr(align(16))` struct attribute (RFC 1358).
     (accepted, repr_align, "1.25.0", Some(33626)),
     /// Allows using `#[repr(align(X))]` on enums with equivalent semantics

compiler/rustc_feature/src/unstable.rs

@@ -621,8 +621,6 @@ declare_features! (
     (incomplete, ref_pat_eat_one_layer_2024_structural, "1.81.0", Some(123076)),
     /// Allows using the `#[register_tool]` attribute.
     (unstable, register_tool, "1.41.0", Some(66079)),
-    /// Allows the `#[repr(i128)]` attribute for enums.
-    (incomplete, repr128, "1.16.0", Some(56071)),
     /// Allows `repr(simd)` and importing the various simd intrinsics.
     (unstable, repr_simd, "1.4.0", Some(27731)),
     /// Allows bounding the return type of AFIT/RPITIT.

compiler/rustc_hir_analysis/src/check/check.rs

@@ -18,7 +18,7 @@ use rustc_middle::middle::resolve_bound_vars::ResolvedArg;
 use rustc_middle::middle::stability::EvalResult;
 use rustc_middle::ty::error::TypeErrorToStringExt;
 use rustc_middle::ty::layout::{LayoutError, MAX_SIMD_LANES};
-use rustc_middle::ty::util::{Discr, IntTypeExt};
+use rustc_middle::ty::util::Discr;
 use rustc_middle::ty::{
     AdtDef, BottomUpFolder, GenericArgKind, RegionKind, TypeFoldable, TypeSuperVisitable,
     TypeVisitable, TypeVisitableExt, fold_regions,
@@ -1385,19 +1385,6 @@ fn check_enum(tcx: TyCtxt<'_>, def_id: LocalDefId) {
         );
     }
 
-    let repr_type_ty = def.repr().discr_type().to_ty(tcx);
-    if repr_type_ty == tcx.types.i128 || repr_type_ty == tcx.types.u128 {
-        if !tcx.features().repr128() {
-            feature_err(
-                &tcx.sess,
-                sym::repr128,
-                tcx.def_span(def_id),
-                "repr with 128-bit type is unstable",
-            )
-            .emit();
-        }
-    }
-
     for v in def.variants() {
         if let ty::VariantDiscr::Explicit(discr_def_id) = v.discr {
             tcx.ensure_ok().typeck(discr_def_id.expect_local());

compiler/rustc_middle/src/mir/interpret/allocation.rs

@@ -512,7 +512,7 @@ impl Allocation {
     pub fn adjust_from_tcx<'tcx, Prov: Provenance, Bytes: AllocBytes>(
         &self,
         cx: &impl HasDataLayout,
-        mut alloc_bytes: impl FnMut(&[u8], Align) -> InterpResult<'tcx, Bytes>,
+        alloc_bytes: impl FnOnce(&[u8], Align) -> InterpResult<'tcx, Bytes>,
         mut adjust_ptr: impl FnMut(Pointer<CtfeProvenance>) -> InterpResult<'tcx, Pointer<Prov>>,
     ) -> InterpResult<'tcx, Allocation<Prov, (), Bytes>> {
         // Copy the data.

library/core/src/intrinsics/mod.rs

@@ -2285,12 +2285,6 @@ pub fn round_ties_even_f16(x: f16) -> f16;
 #[rustc_nounwind]
 pub fn round_ties_even_f32(x: f32) -> f32;
 
-/// Provided for compatibility with stdarch. DO NOT USE.
-#[inline(always)]
-pub unsafe fn rintf32(x: f32) -> f32 {
-    round_ties_even_f32(x)
-}
-
 /// Returns the nearest integer to an `f64`. Rounds half-way cases to the number with an even
 /// least significant digit.
 ///
@@ -2300,12 +2294,6 @@ pub unsafe fn rintf32(x: f32) -> f32 {
 #[rustc_nounwind]
 pub fn round_ties_even_f64(x: f64) -> f64;
 
-/// Provided for compatibility with stdarch. DO NOT USE.
-#[inline(always)]
-pub unsafe fn rintf64(x: f64) -> f64 {
-    round_ties_even_f64(x)
-}
-
 /// Returns the nearest integer to an `f128`. Rounds half-way cases to the number with an even
 /// least significant digit.
 ///

library/core/src/marker/variance.rs

@@ -131,6 +131,8 @@ phantom_lifetime! {
     ///
     /// [1]: https://doc.rust-lang.org/stable/reference/subtyping.html#variance
     ///
+    /// Note: If `'a` is otherwise contravariant or invariant, the resulting type is invariant.
+    ///
     /// ## Layout
     ///
     /// For all `'a`, the following are guaranteed:
@@ -146,6 +148,8 @@ phantom_lifetime! {
     ///
     /// [1]: https://doc.rust-lang.org/stable/reference/subtyping.html#variance
     ///
+    /// Note: If `'a` is otherwise covariant or invariant, the resulting type is invariant.
+    ///
     /// ## Layout
     ///
     /// For all `'a`, the following are guaranteed:
@@ -180,6 +184,8 @@ phantom_type! {
     ///
     /// [1]: https://doc.rust-lang.org/stable/reference/subtyping.html#variance
     ///
+    /// Note: If `T` is otherwise contravariant or invariant, the resulting type is invariant.
+    ///
     /// ## Layout
     ///
     /// For all `T`, the following are guaranteed:
@@ -196,6 +202,8 @@ phantom_type! {
     ///
     /// [1]: https://doc.rust-lang.org/stable/reference/subtyping.html#variance
     ///
+    /// Note: If `T` is otherwise covariant or invariant, the resulting type is invariant.
+    ///
     /// ## Layout
     ///
     /// For all `T`, the following are guaranteed: