Rollup of 8 pull requests

compiler/rustc_mir_build/src/thir/pattern/check_match.rs

@@ -1130,7 +1130,7 @@ fn collect_non_exhaustive_tys<'tcx>(
         non_exhaustive_tys.insert(pat.ty().inner());
     }
     if let Constructor::IntRange(range) = pat.ctor() {
-        if cx.is_range_beyond_boundaries(range, pat.ty()) {
+        if cx.is_range_beyond_boundaries(range, *pat.ty()) {
             // The range denotes the values before `isize::MIN` or the values after `usize::MAX`/`isize::MAX`.
             non_exhaustive_tys.insert(pat.ty().inner());
         }

compiler/rustc_monomorphize/src/partitioning.rs

@@ -182,7 +182,7 @@ where
     }
 
     // Ensure CGUs are sorted by name, so that we get deterministic results.
-    if !codegen_units.is_sorted_by(|a, b| Some(a.name().as_str().cmp(b.name().as_str()))) {
+    if !codegen_units.is_sorted_by(|a, b| a.name().as_str() <= b.name().as_str()) {
         let mut names = String::new();
         for cgu in codegen_units.iter() {
             names += &format!("- {}\n", cgu.name());
@@ -317,7 +317,7 @@ fn merge_codegen_units<'tcx>(
     assert!(cx.tcx.sess.codegen_units().as_usize() >= 1);
 
     // A sorted order here ensures merging is deterministic.
-    assert!(codegen_units.is_sorted_by(|a, b| Some(a.name().as_str().cmp(b.name().as_str()))));
+    assert!(codegen_units.is_sorted_by(|a, b| a.name().as_str() <= b.name().as_str()));
 
     // This map keeps track of what got merged into what.
     let mut cgu_contents: FxHashMap<Symbol, Vec<Symbol>> =

compiler/rustc_pattern_analysis/src/lib.rs

@@ -82,7 +82,7 @@ impl<'a, T: ?Sized> Captures<'a> for T {}
 /// Most of the crate is parameterized on a type that implements this trait.
 pub trait TypeCx: Sized + fmt::Debug {
     /// The type of a pattern.
-    type Ty: Copy + Clone + fmt::Debug; // FIXME: remove Copy
+    type Ty: Clone + fmt::Debug;
     /// Errors that can abort analysis.
     type Error: fmt::Debug;
     /// The index of an enum variant.
@@ -97,16 +97,16 @@ pub trait TypeCx: Sized + fmt::Debug {
     fn is_exhaustive_patterns_feature_on(&self) -> bool;
 
     /// The number of fields for this constructor.
-    fn ctor_arity(&self, ctor: &Constructor<Self>, ty: Self::Ty) -> usize;
+    fn ctor_arity(&self, ctor: &Constructor<Self>, ty: &Self::Ty) -> usize;
 
     /// The types of the fields for this constructor. The result must have a length of
     /// `ctor_arity()`.
-    fn ctor_sub_tys(&self, ctor: &Constructor<Self>, ty: Self::Ty) -> &[Self::Ty];
+    fn ctor_sub_tys(&self, ctor: &Constructor<Self>, ty: &Self::Ty) -> &[Self::Ty];
 
     /// The set of all the constructors for `ty`.
     ///
     /// This must follow the invariants of `ConstructorSet`
-    fn ctors_for_ty(&self, ty: Self::Ty) -> Result<ConstructorSet<Self>, Self::Error>;
+    fn ctors_for_ty(&self, ty: &Self::Ty) -> Result<ConstructorSet<Self>, Self::Error>;
 
     /// Best-effort `Debug` implementation.
     fn debug_pat(f: &mut fmt::Formatter<'_>, pat: &DeconstructedPat<'_, Self>) -> fmt::Result;

compiler/rustc_pattern_analysis/src/lints.rs

@@ -46,7 +46,7 @@ impl<'p, 'tcx> PatternColumn<'p, 'tcx> {
     }
 
     fn head_ty(&self) -> Option<RevealedTy<'tcx>> {
-        self.patterns.first().map(|pat| pat.ty())
+        self.patterns.first().map(|pat| *pat.ty())
     }
 
     /// Do constructor splitting on the constructors of the column.
@@ -101,7 +101,7 @@ fn collect_nonexhaustive_missing_variants<'a, 'p, 'tcx>(
     let Some(ty) = column.head_ty() else {
         return Ok(Vec::new());
     };
-    let pcx = &PlaceCtxt::new_dummy(cx, ty);
+    let pcx = &PlaceCtxt::new_dummy(cx, &ty);
 
     let set = column.analyze_ctors(pcx)?;
     if set.present.is_empty() {

compiler/rustc_pattern_analysis/src/pat.rs

@@ -54,8 +54,8 @@ impl<'p, Cx: TypeCx> DeconstructedPat<'p, Cx> {
     pub fn ctor(&self) -> &Constructor<Cx> {
         &self.ctor
     }
-    pub fn ty(&self) -> Cx::Ty {
-        self.ty
+    pub fn ty(&self) -> &Cx::Ty {
+        &self.ty
     }
     /// Returns the extra data stored in a pattern. Returns `None` if the pattern is a wildcard that
     /// does not correspond to a user-supplied pattern.
@@ -242,15 +242,15 @@ impl<Cx: TypeCx> WitnessPat<Cx> {
     /// `Some(_)`.
     pub(crate) fn wild_from_ctor(pcx: &PlaceCtxt<'_, Cx>, ctor: Constructor<Cx>) -> Self {
         let field_tys = pcx.ctor_sub_tys(&ctor);
-        let fields = field_tys.iter().map(|ty| Self::wildcard(*ty)).collect();
-        Self::new(ctor, fields, pcx.ty)
+        let fields = field_tys.iter().cloned().map(|ty| Self::wildcard(ty)).collect();
+        Self::new(ctor, fields, pcx.ty.clone())
     }
 
     pub fn ctor(&self) -> &Constructor<Cx> {
         &self.ctor
     }
-    pub fn ty(&self) -> Cx::Ty {
-        self.ty
+    pub fn ty(&self) -> &Cx::Ty {
+        &self.ty
     }
 
     pub fn iter_fields(&self) -> impl Iterator<Item = &WitnessPat<Cx>> {

compiler/rustc_pattern_analysis/src/rustc.rs

@@ -766,7 +766,7 @@ impl<'p, 'tcx> RustcMatchCheckCtxt<'p, 'tcx> {
         let mut subpatterns = pat.iter_fields().map(|p| Box::new(cx.hoist_witness_pat(p)));
         let kind = match pat.ctor() {
             Bool(b) => PatKind::Constant { value: mir::Const::from_bool(cx.tcx, *b) },
-            IntRange(range) => return self.hoist_pat_range(range, pat.ty()),
+            IntRange(range) => return self.hoist_pat_range(range, *pat.ty()),
             Struct | Variant(_) | UnionField => match pat.ty().kind() {
                 ty::Tuple(..) => PatKind::Leaf {
                     subpatterns: subpatterns
@@ -785,7 +785,7 @@ impl<'p, 'tcx> RustcMatchCheckCtxt<'p, 'tcx> {
                         RustcMatchCheckCtxt::variant_index_for_adt(&pat.ctor(), *adt_def);
                     let variant = &adt_def.variant(variant_index);
                     let subpatterns = cx
-                        .list_variant_nonhidden_fields(pat.ty(), variant)
+                        .list_variant_nonhidden_fields(*pat.ty(), variant)
                         .zip(subpatterns)
                         .map(|((field, _ty), pattern)| FieldPat { field, pattern })
                         .collect();
@@ -796,7 +796,7 @@ impl<'p, 'tcx> RustcMatchCheckCtxt<'p, 'tcx> {
                         PatKind::Leaf { subpatterns }
                     }
                 }
-                _ => bug!("unexpected ctor for type {:?} {:?}", pat.ctor(), pat.ty()),
+                _ => bug!("unexpected ctor for type {:?} {:?}", pat.ctor(), *pat.ty()),
             },
             // Note: given the expansion of `&str` patterns done in `expand_pattern`, we should
             // be careful to reconstruct the correct constant pattern here. However a string
@@ -961,21 +961,21 @@ impl<'p, 'tcx> TypeCx for RustcMatchCheckCtxt<'p, 'tcx> {
         self.tcx.features().exhaustive_patterns
     }
 
-    fn ctor_arity(&self, ctor: &crate::constructor::Constructor<Self>, ty: Self::Ty) -> usize {
-        self.ctor_arity(ctor, ty)
+    fn ctor_arity(&self, ctor: &crate::constructor::Constructor<Self>, ty: &Self::Ty) -> usize {
+        self.ctor_arity(ctor, *ty)
     }
     fn ctor_sub_tys(
         &self,
         ctor: &crate::constructor::Constructor<Self>,
-        ty: Self::Ty,
+        ty: &Self::Ty,
     ) -> &[Self::Ty] {
-        self.ctor_sub_tys(ctor, ty)
+        self.ctor_sub_tys(ctor, *ty)
     }
     fn ctors_for_ty(
         &self,
-        ty: Self::Ty,
+        ty: &Self::Ty,
     ) -> Result<crate::constructor::ConstructorSet<Self>, Self::Error> {
-        self.ctors_for_ty(ty)
+        self.ctors_for_ty(*ty)
     }
 
     fn debug_pat(
@@ -994,7 +994,7 @@ impl<'p, 'tcx> TypeCx for RustcMatchCheckCtxt<'p, 'tcx> {
         overlaps_on: IntRange,
         overlaps_with: &[&crate::pat::DeconstructedPat<'_, Self>],
     ) {
-        let overlap_as_pat = self.hoist_pat_range(&overlaps_on, pat.ty());
+        let overlap_as_pat = self.hoist_pat_range(&overlaps_on, *pat.ty());
         let overlaps: Vec<_> = overlaps_with
             .iter()
             .map(|pat| pat.data().unwrap().span)

compiler/rustc_pattern_analysis/src/usefulness.rs

@@ -736,13 +736,14 @@ pub(crate) struct PlaceCtxt<'a, Cx: TypeCx> {
     #[derivative(Debug = "ignore")]
     pub(crate) mcx: MatchCtxt<'a, Cx>,
     /// Type of the place under investigation.
-    pub(crate) ty: Cx::Ty,
+    #[derivative(Clone(clone_with = "Clone::clone"))] // See rust-derivative#90
+    pub(crate) ty: &'a Cx::Ty,
 }
 
 impl<'a, Cx: TypeCx> PlaceCtxt<'a, Cx> {
     /// A `PlaceCtxt` when code other than `is_useful` needs one.
     #[cfg_attr(not(feature = "rustc"), allow(dead_code))]
-    pub(crate) fn new_dummy(mcx: MatchCtxt<'a, Cx>, ty: Cx::Ty) -> Self {
+    pub(crate) fn new_dummy(mcx: MatchCtxt<'a, Cx>, ty: &'a Cx::Ty) -> Self {
         PlaceCtxt { mcx, ty }
     }
 
@@ -1023,8 +1024,8 @@ impl<'p, Cx: TypeCx> Matrix<'p, Cx> {
         matrix
     }
 
-    fn head_ty(&self) -> Option<Cx::Ty> {
-        self.place_ty.first().copied()
+    fn head_ty(&self) -> Option<&Cx::Ty> {
+        self.place_ty.first()
     }
     fn column_count(&self) -> usize {
         self.place_ty.len()
@@ -1058,7 +1059,7 @@ impl<'p, Cx: TypeCx> Matrix<'p, Cx> {
         let ctor_sub_tys = pcx.ctor_sub_tys(ctor);
         let arity = ctor_sub_tys.len();
         let specialized_place_ty =
-            ctor_sub_tys.iter().chain(self.place_ty[1..].iter()).copied().collect();
+            ctor_sub_tys.iter().chain(self.place_ty[1..].iter()).cloned().collect();
         let ctor_sub_validity = self.place_validity[0].specialize(ctor);
         let specialized_place_validity = std::iter::repeat(ctor_sub_validity)
             .take(arity)
@@ -1214,7 +1215,7 @@ impl<Cx: TypeCx> WitnessStack<Cx> {
         let len = self.0.len();
         let arity = ctor.arity(pcx);
         let fields = self.0.drain((len - arity)..).rev().collect();
-        let pat = WitnessPat::new(ctor.clone(), fields, pcx.ty);
+        let pat = WitnessPat::new(ctor.clone(), fields, pcx.ty.clone());
         self.0.push(pat);
     }
 }
@@ -1410,7 +1411,7 @@ fn compute_exhaustiveness_and_usefulness<'a, 'p, Cx: TypeCx>(
         return Ok(WitnessMatrix::empty());
     }
 
-    let Some(ty) = matrix.head_ty() else {
+    let Some(ty) = matrix.head_ty().cloned() else {
         // The base case: there are no columns in the matrix. We are morally pattern-matching on ().
         // A row is useful iff it has no (unguarded) rows above it.
         let mut useful = true; // Whether the next row is useful.
@@ -1431,7 +1432,7 @@ fn compute_exhaustiveness_and_usefulness<'a, 'p, Cx: TypeCx>(
     };
 
     debug!("ty: {ty:?}");
-    let pcx = &PlaceCtxt { mcx, ty };
+    let pcx = &PlaceCtxt { mcx, ty: &ty };
     let ctors_for_ty = pcx.ctors_for_ty()?;
 
     // Whether the place/column we are inspecting is known to contain valid data.

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

@@ -4033,42 +4033,42 @@ pub trait Iterator {
         Self: Sized,
         Self::Item: PartialOrd,
     {
-        self.is_sorted_by(PartialOrd::partial_cmp)
+        self.is_sorted_by(|a, b| a <= b)
     }
 
     /// Checks if the elements of this iterator are sorted using the given comparator function.
     ///
     /// Instead of using `PartialOrd::partial_cmp`, this function uses the given `compare`
-    /// function to determine the ordering of two elements. Apart from that, it's equivalent to
-    /// [`is_sorted`]; see its documentation for more information.
+    /// function to determine whether two elements are to be considered in sorted order.
     ///
     /// # Examples
     ///
     /// ```
     /// #![feature(is_sorted)]
     ///
-    /// assert!([1, 2, 2, 9].iter().is_sorted_by(|a, b| a.partial_cmp(b)));
-    /// assert!(![1, 3, 2, 4].iter().is_sorted_by(|a, b| a.partial_cmp(b)));
-    /// assert!([0].iter().is_sorted_by(|a, b| a.partial_cmp(b)));
-    /// assert!(std::iter::empty::<i32>().is_sorted_by(|a, b| a.partial_cmp(b)));
-    /// assert!(![0.0, 1.0, f32::NAN].iter().is_sorted_by(|a, b| a.partial_cmp(b)));
-    /// ```
+    /// assert!([1, 2, 2, 9].iter().is_sorted_by(|a, b| a <= b));
+    /// assert!(![1, 2, 2, 9].iter().is_sorted_by(|a, b| a < b));
     ///
-    /// [`is_sorted`]: Iterator::is_sorted
+    /// assert!([0].iter().is_sorted_by(|a, b| true));
+    /// assert!([0].iter().is_sorted_by(|a, b| false));
+    ///
+    /// assert!(std::iter::empty::<i32>().is_sorted_by(|a, b| false));
+    /// assert!(std::iter::empty::<i32>().is_sorted_by(|a, b| true));
+    /// ```
     #[unstable(feature = "is_sorted", reason = "new API", issue = "53485")]
     #[rustc_do_not_const_check]
     fn is_sorted_by<F>(mut self, compare: F) -> bool
     where
         Self: Sized,
-        F: FnMut(&Self::Item, &Self::Item) -> Option<Ordering>,
+        F: FnMut(&Self::Item, &Self::Item) -> bool,
     {
         #[inline]
         fn check<'a, T>(
             last: &'a mut T,
-            mut compare: impl FnMut(&T, &T) -> Option<Ordering> + 'a,
+            mut compare: impl FnMut(&T, &T) -> bool + 'a,
         ) -> impl FnMut(T) -> bool + 'a {
             move |curr| {
-                if let Some(Ordering::Greater) | None = compare(&last, &curr) {
+                if !compare(&last, &curr) {
                     return false;
                 }
                 *last = curr;

library/core/src/lib.rs

@@ -161,6 +161,7 @@
 #![feature(const_slice_ptr_len)]
 #![feature(const_slice_split_at_mut)]
 #![feature(const_str_from_utf8_unchecked_mut)]
+#![feature(const_strict_overflow_ops)]
 #![feature(const_swap)]
 #![feature(const_try)]
 #![feature(const_type_id)]

library/core/src/net/ip_addr.rs

@@ -1785,6 +1785,31 @@ impl Ipv6Addr {
         (self.segments()[0] & 0xff00) == 0xff00
     }
 
+    /// Returns [`true`] if the address is an IPv4-mapped address (`::ffff:0:0/96`).
+    ///
+    /// IPv4-mapped addresses can be converted to their canonical IPv4 address with
+    /// [`to_ipv4_mapped`](Ipv6Addr::to_ipv4_mapped).
+    ///
+    /// # Examples
+    /// ```
+    /// #![feature(ip)]
+    ///
+    /// use std::net::{Ipv4Addr, Ipv6Addr};
+    ///
+    /// let ipv4_mapped = Ipv4Addr::new(192, 0, 2, 255).to_ipv6_mapped();
+    /// assert_eq!(ipv4_mapped.is_ipv4_mapped(), true);
+    /// assert_eq!(Ipv6Addr::new(0, 0, 0, 0, 0, 0xffff, 0xc000, 0x2ff).is_ipv4_mapped(), true);
+    ///
+    /// assert_eq!(Ipv6Addr::new(0x2001, 0xdb8, 0, 0, 0, 0, 0, 0).is_ipv4_mapped(), false);
+    /// ```
+    #[rustc_const_unstable(feature = "const_ipv6", issue = "76205")]
+    #[unstable(feature = "ip", issue = "27709")]
+    #[must_use]
+    #[inline]
+    pub const fn is_ipv4_mapped(&self) -> bool {
+        matches!(self.segments(), [0, 0, 0, 0, 0, 0xffff, _, _])
+    }
+
     /// Converts this address to an [`IPv4` address] if it's an [IPv4-mapped] address,
     /// as defined in [IETF RFC 4291 section 2.5.5.2], otherwise returns [`None`].
     ///