Rollup of 9 pull requests

compiler/rustc_codegen_ssa/src/mir/rvalue.rs

@@ -630,7 +630,17 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                 OperandRef { val: OperandValue::Immediate(static_), layout }
             }
             mir::Rvalue::Use(ref operand) => self.codegen_operand(bx, operand),
-            mir::Rvalue::Repeat(..) => bug!("{rvalue:?} in codegen_rvalue_operand"),
+            mir::Rvalue::Repeat(ref elem, len_const) => {
+                // All arrays have `BackendRepr::Memory`, so only the ZST cases
+                // end up here. Anything else forces the destination local to be
+                // `Memory`, and thus ends up handled in `codegen_rvalue` instead.
+                let operand = self.codegen_operand(bx, elem);
+                let array_ty = Ty::new_array_with_const_len(bx.tcx(), operand.layout.ty, len_const);
+                let array_ty = self.monomorphize(array_ty);
+                let array_layout = bx.layout_of(array_ty);
+                assert!(array_layout.is_zst());
+                OperandRef { val: OperandValue::ZeroSized, layout: array_layout }
+            }
             mir::Rvalue::Aggregate(ref kind, ref fields) => {
                 let (variant_index, active_field_index) = match **kind {
                     mir::AggregateKind::Adt(_, variant_index, _, _, active_field_index) => {
@@ -1000,12 +1010,10 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
             mir::Rvalue::NullaryOp(..) |
             mir::Rvalue::ThreadLocalRef(_) |
             mir::Rvalue::Use(..) |
+            mir::Rvalue::Repeat(..) | // (*)
             mir::Rvalue::Aggregate(..) | // (*)
             mir::Rvalue::WrapUnsafeBinder(..) => // (*)
                 true,
-            // Arrays are always aggregates, so it's not worth checking anything here.
-            // (If it's really `[(); N]` or `[T; 0]` and we use the place path, fine.)
-            mir::Rvalue::Repeat(..) => false,
         }
 
         // (*) this is only true if the type is suitable

compiler/rustc_codegen_ssa/src/target_features.rs

@@ -149,14 +149,14 @@ fn parse_rust_feature_flag<'a>(
         if let Some(base_feature) = feature.strip_prefix('+') {
             // Skip features that are not target features, but rustc features.
             if RUSTC_SPECIFIC_FEATURES.contains(&base_feature) {
-                return;
+                continue;
             }
 
             callback(base_feature, sess.target.implied_target_features(base_feature), true)
         } else if let Some(base_feature) = feature.strip_prefix('-') {
             // Skip features that are not target features, but rustc features.
             if RUSTC_SPECIFIC_FEATURES.contains(&base_feature) {
-                return;
+                continue;
             }
 
             // If `f1` implies `f2`, then `!f2` implies `!f1` -- this is standard logical

compiler/rustc_mir_transform/src/validate.rs

@@ -119,14 +119,16 @@ impl<'a, 'tcx> CfgChecker<'a, 'tcx> {
     #[track_caller]
     fn fail(&self, location: Location, msg: impl AsRef<str>) {
         // We might see broken MIR when other errors have already occurred.
-        assert!(
-            self.tcx.dcx().has_errors().is_some(),
-            "broken MIR in {:?} ({}) at {:?}:\n{}",
-            self.body.source.instance,
-            self.when,
-            location,
-            msg.as_ref(),
-        );
+        if self.tcx.dcx().has_errors().is_none() {
+            span_bug!(
+                self.body.source_info(location).span,
+                "broken MIR in {:?} ({}) at {:?}:\n{}",
+                self.body.source.instance,
+                self.when,
+                location,
+                msg.as_ref(),
+            );
+        }
     }
 
     fn check_edge(&mut self, location: Location, bb: BasicBlock, edge_kind: EdgeKind) {

library/core/src/async_iter/async_iter.rs

@@ -28,15 +28,15 @@ pub trait AsyncIterator {
     /// async iterator state:
     ///
     /// - `Poll::Pending` means that this async iterator's next value is not ready
-    /// yet. Implementations will ensure that the current task will be notified
-    /// when the next value may be ready.
+    ///   yet. Implementations will ensure that the current task will be notified
+    ///   when the next value may be ready.
     ///
     /// - `Poll::Ready(Some(val))` means that the async iterator has successfully
-    /// produced a value, `val`, and may produce further values on subsequent
-    /// `poll_next` calls.
+    ///   produced a value, `val`, and may produce further values on subsequent
+    ///   `poll_next` calls.
     ///
     /// - `Poll::Ready(None)` means that the async iterator has terminated, and
-    /// `poll_next` should not be invoked again.
+    ///   `poll_next` should not be invoked again.
     ///
     /// # Panics
     ///

library/core/src/cmp.rs

@@ -1482,13 +1482,14 @@ pub trait PartialOrd<Rhs: PointeeSized = Self>: PartialEq<Rhs> + PointeeSized {
     }
 }
 
-fn default_chaining_impl<T: PointeeSized, U: PointeeSized>(
+fn default_chaining_impl<T, U>(
     lhs: &T,
     rhs: &U,
     p: impl FnOnce(Ordering) -> bool,
 ) -> ControlFlow<bool>
 where
-    T: PartialOrd<U>,
+    T: PartialOrd<U> + PointeeSized,
+    U: PointeeSized,
 {
     // It's important that this only call `partial_cmp` once, not call `eq` then
     // one of the relational operators.  We don't want to `bcmp`-then-`memcp` a

library/core/src/fmt/mod.rs

@@ -854,7 +854,6 @@ impl Display for Arguments<'_> {
 /// }";
 /// assert_eq!(format!("The origin is: {origin:#?}"), expected);
 /// ```
-
 #[stable(feature = "rust1", since = "1.0.0")]
 #[rustc_on_unimplemented(
     on(

library/core/src/iter/traits/collect.rs

@@ -436,7 +436,6 @@ pub trait Extend<A> {
     /// **For implementors:** For a collection to unsafely rely on this method's safety precondition (that is,
     /// invoke UB if they are violated), it must implement `extend_reserve` correctly. In other words,
     /// callers may assume that if they `extend_reserve`ed enough space they can call this method.
-
     // This method is for internal usage only. It is only on the trait because of specialization's limitations.
     #[unstable(feature = "extend_one_unchecked", issue = "none")]
     #[doc(hidden)]

library/core/src/iter/traits/iterator.rs

@@ -3414,10 +3414,10 @@ pub trait Iterator {
     /// ```
     #[stable(feature = "iter_copied", since = "1.36.0")]
     #[rustc_diagnostic_item = "iter_copied"]
-    fn copied<'a, T: 'a>(self) -> Copied<Self>
+    fn copied<'a, T>(self) -> Copied<Self>
     where
+        T: Copy + 'a,
         Self: Sized + Iterator<Item = &'a T>,
-        T: Copy,
     {
         Copied::new(self)
     }
@@ -3462,10 +3462,10 @@ pub trait Iterator {
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
     #[rustc_diagnostic_item = "iter_cloned"]
-    fn cloned<'a, T: 'a>(self) -> Cloned<Self>
+    fn cloned<'a, T>(self) -> Cloned<Self>
     where
+        T: Clone + 'a,
         Self: Sized + Iterator<Item = &'a T>,
-        T: Clone,
     {
         Cloned::new(self)
     }

library/core/src/lib.rs

@@ -39,9 +39,9 @@
 //!   return. You should mark your implementation using `#[panic_handler]`.
 //!
 //! * `rust_eh_personality` - is used by the failure mechanisms of the
-//!    compiler. This is often mapped to GCC's personality function, but crates
-//!    which do not trigger a panic can be assured that this function is never
-//!    called. The `lang` attribute is called `eh_personality`.
+//!   compiler. This is often mapped to GCC's personality function, but crates
+//!   which do not trigger a panic can be assured that this function is never
+//!   called. The `lang` attribute is called `eh_personality`.
 
 #![stable(feature = "core", since = "1.6.0")]
 #![doc(

library/core/src/mem/mod.rs

@@ -36,7 +36,7 @@ pub use crate::intrinsics::transmute;
 /// * If you want to leak memory, see [`Box::leak`].
 /// * If you want to obtain a raw pointer to the memory, see [`Box::into_raw`].
 /// * If you want to dispose of a value properly, running its destructor, see
-/// [`mem::drop`].
+///   [`mem::drop`].
 ///
 /// # Safety
 ///

library/core/src/net/ip_addr.rs

@@ -787,7 +787,6 @@ impl Ipv4Addr {
     /// [IANA IPv4 Special-Purpose Address Registry]: https://www.iana.org/assignments/iana-ipv4-special-registry/iana-ipv4-special-registry.xhtml
     /// [unspecified address]: Ipv4Addr::UNSPECIFIED
     /// [broadcast address]: Ipv4Addr::BROADCAST
-
     ///
     /// # Examples
     ///

library/core/src/num/int_log10.rs

@@ -1,5 +1,5 @@
-/// These functions compute the integer logarithm of their type, assuming
-/// that someone has already checked that the value is strictly positive.
+//! These functions compute the integer logarithm of their type, assuming
+//! that someone has already checked that the value is strictly positive.
 
 // 0 < val <= u8::MAX
 #[inline]

library/core/src/num/uint_macros.rs

@@ -556,7 +556,7 @@ macro_rules! uint_impl {
         pub const fn strict_add(self, rhs: Self) -> Self {
             let (a, b) = self.overflowing_add(rhs);
             if b { overflow_panic::add() } else { a }
-         }
+        }
 
         /// Unchecked integer addition. Computes `self + rhs`, assuming overflow
         /// cannot occur.
@@ -653,7 +653,7 @@ macro_rules! uint_impl {
         pub const fn strict_add_signed(self, rhs: $SignedT) -> Self {
             let (a, b) = self.overflowing_add_signed(rhs);
             if b { overflow_panic::add() } else { a }
-         }
+        }
 
         /// Checked integer subtraction. Computes `self - rhs`, returning
         /// `None` if overflow occurred.
@@ -713,7 +713,7 @@ macro_rules! uint_impl {
         pub const fn strict_sub(self, rhs: Self) -> Self {
             let (a, b) = self.overflowing_sub(rhs);
             if b { overflow_panic::sub() } else { a }
-         }
+        }
 
         /// Unchecked integer subtraction. Computes `self - rhs`, assuming overflow
         /// cannot occur.
@@ -805,6 +805,43 @@ macro_rules! uint_impl {
             }
         }
 
+        /// Strict subtraction with a signed integer. Computes `self - rhs`,
+        /// panicking if overflow occurred.
+        ///
+        /// # Panics
+        ///
+        /// ## Overflow behavior
+        ///
+        /// This function will always panic on overflow, regardless of whether overflow checks are enabled.
+        ///
+        /// # Examples
+        ///
+        /// ```
+        /// #![feature(strict_overflow_ops)]
+        #[doc = concat!("assert_eq!(3", stringify!($SelfT), ".strict_sub_signed(2), 1);")]
+        /// ```
+        ///
+        /// The following panic because of overflow:
+        ///
+        /// ```should_panic
+        /// #![feature(strict_overflow_ops)]
+        #[doc = concat!("let _ = 1", stringify!($SelfT), ".strict_sub_signed(2);")]
+        /// ```
+        ///
+        /// ```should_panic
+        /// #![feature(strict_overflow_ops)]
+        #[doc = concat!("let _ = (", stringify!($SelfT), "::MAX).strict_sub_signed(-1);")]
+        /// ```
+        #[unstable(feature = "strict_overflow_ops", issue = "118260")]
+        #[must_use = "this returns the result of the operation, \
+                      without modifying the original"]
+        #[inline]
+        #[track_caller]
+        pub const fn strict_sub_signed(self, rhs: $SignedT) -> Self {
+            let (a, b) = self.overflowing_sub_signed(rhs);
+            if b { overflow_panic::sub() } else { a }
+        }
+
         #[doc = concat!(
             "Checked integer subtraction. Computes `self - rhs` and checks if the result fits into an [`",
             stringify!($SignedT), "`], returning `None` if overflow occurred."
@@ -913,7 +950,7 @@ macro_rules! uint_impl {
         pub const fn strict_mul(self, rhs: Self) -> Self {
             let (a, b) = self.overflowing_mul(rhs);
             if b { overflow_panic::mul() } else { a }
-         }
+        }
 
         /// Unchecked integer multiplication. Computes `self * rhs`, assuming overflow
         /// cannot occur.

library/core/src/primitive_docs.rs

@@ -1363,7 +1363,6 @@ mod prim_f16 {}
 /// x = a + b + c + d; // As written
 /// x = (a + c) + (b + d); // Reordered to shorten critical path and enable vectorization
 /// ```
-
 #[stable(feature = "rust1", since = "1.0.0")]
 mod prim_f32 {}
 

library/core/src/ptr/docs/as_uninit_slice.md

@@ -10,24 +10,24 @@ When calling this method, you have to ensure that *either* the pointer is null *
 all of the following is true:
 
 * The pointer must be [valid] for reads for `ptr.len() * size_of::<T>()` many bytes,
-and it must be properly aligned. This means in particular:
+  and it must be properly aligned. This means in particular:
 
 * The entire memory range of this slice must be contained within a single [allocation]!
-Slices can never span across multiple allocations.
+  Slices can never span across multiple allocations.
 
 * The pointer must be aligned even for zero-length slices. One
-reason for this is that enum layout optimizations may rely on references
-(including slices of any length) being aligned and non-null to distinguish
-them from other data. You can obtain a pointer that is usable as `data`
-for zero-length slices using [`NonNull::dangling()`].
+  reason for this is that enum layout optimizations may rely on references
+  (including slices of any length) being aligned and non-null to distinguish
+  them from other data. You can obtain a pointer that is usable as `data`
+  for zero-length slices using [`NonNull::dangling()`].
 
 * The total size `ptr.len() * size_of::<T>()` of the slice must be no larger than `isize::MAX`.
-See the safety documentation of [`pointer::offset`].
+  See the safety documentation of [`pointer::offset`].
 
 * You must enforce Rust's aliasing rules, since the returned lifetime `'a` is
-arbitrarily chosen and does not necessarily reflect the actual lifetime of the data.
-In particular, while this reference exists, the memory the pointer points to must
-not get mutated (except inside `UnsafeCell`).
+  arbitrarily chosen and does not necessarily reflect the actual lifetime of the data.
+  In particular, while this reference exists, the memory the pointer points to must
+  not get mutated (except inside `UnsafeCell`).
 
 This applies even if the result of this method is unused!
 

library/core/src/str/mod.rs

@@ -2651,7 +2651,6 @@ impl str {
     /// you're trying to parse into.
     ///
     /// `parse` can parse into any type that implements the [`FromStr`] trait.
-
     ///
     /// # Errors
     ///

src/bootstrap/src/core/build_steps/check.rs

@@ -355,7 +355,7 @@ impl Step for CodegenBackend {
         cargo
             .arg("--manifest-path")
             .arg(builder.src.join(format!("compiler/rustc_codegen_{backend}/Cargo.toml")));
-        rustc_cargo_env(builder, &mut cargo, target, build_compiler.stage);
+        rustc_cargo_env(builder, &mut cargo, target);
 
         let _guard = builder.msg_check(format!("rustc_codegen_{backend}"), target, None);