Rollup of 8 pull requests

.gitignore

@@ -20,6 +20,8 @@ Session.vim
 .vscode
 .project
 .vim/
+.helix/
+.zed/
 .favorites.json
 .settings/
 .vs/

compiler/rustc_hir_analysis/src/check/compare_impl_item.rs

@@ -1117,7 +1117,7 @@ fn check_region_bounds_on_impl_item<'tcx>(
             .dcx()
             .create_err(LifetimesOrBoundsMismatchOnTrait {
                 span,
-                item_kind: assoc_item_kind_str(&impl_m),
+                item_kind: impl_m.descr(),
                 ident: impl_m.ident(tcx),
                 generics_span,
                 bounds_span,
@@ -1294,7 +1294,7 @@ fn compare_number_of_generics<'tcx>(
         ("const", trait_own_counts.consts, impl_own_counts.consts),
     ];
 
-    let item_kind = assoc_item_kind_str(&impl_);
+    let item_kind = impl_.descr();
 
     let mut err_occurred = None;
     for (kind, trait_count, impl_count) in matchings {
@@ -1676,7 +1676,7 @@ fn compare_generic_param_kinds<'tcx>(
                 param_impl_span,
                 E0053,
                 "{} `{}` has an incompatible generic parameter for trait `{}`",
-                assoc_item_kind_str(&impl_item),
+                impl_item.descr(),
                 trait_item.name,
                 &tcx.def_path_str(tcx.parent(trait_item.def_id))
             );
@@ -2249,14 +2249,6 @@ fn param_env_with_gat_bounds<'tcx>(
     ty::ParamEnv::new(tcx.mk_clauses(&predicates), Reveal::UserFacing)
 }
 
-fn assoc_item_kind_str(impl_item: &ty::AssocItem) -> &'static str {
-    match impl_item.kind {
-        ty::AssocKind::Const => "const",
-        ty::AssocKind::Fn => "method",
-        ty::AssocKind::Type => "type",
-    }
-}
-
 /// Manually check here that `async fn foo()` wasn't matched against `fn foo()`,
 /// and extract a better error if so.
 fn try_report_async_mismatch<'tcx>(

compiler/rustc_lint/src/builtin.rs

@@ -1924,14 +1924,13 @@ declare_lint_pass!(ExplicitOutlivesRequirements => [EXPLICIT_OUTLIVES_REQUIREMEN
 impl ExplicitOutlivesRequirements {
     fn lifetimes_outliving_lifetime<'tcx>(
         tcx: TyCtxt<'tcx>,
-        inferred_outlives: &'tcx [(ty::Clause<'tcx>, Span)],
+        inferred_outlives: impl Iterator<Item = &'tcx (ty::Clause<'tcx>, Span)>,
         item: DefId,
         lifetime: DefId,
     ) -> Vec<ty::Region<'tcx>> {
         let item_generics = tcx.generics_of(item);
 
         inferred_outlives
-            .iter()
             .filter_map(|(clause, _)| match clause.kind().skip_binder() {
                 ty::ClauseKind::RegionOutlives(ty::OutlivesPredicate(a, b)) => match *a {
                     ty::ReEarlyParam(ebr)
@@ -1947,11 +1946,10 @@ impl ExplicitOutlivesRequirements {
     }
 
     fn lifetimes_outliving_type<'tcx>(
-        inferred_outlives: &'tcx [(ty::Clause<'tcx>, Span)],
+        inferred_outlives: impl Iterator<Item = &'tcx (ty::Clause<'tcx>, Span)>,
         index: u32,
     ) -> Vec<ty::Region<'tcx>> {
         inferred_outlives
-            .iter()
             .filter_map(|(clause, _)| match clause.kind().skip_binder() {
                 ty::ClauseKind::TypeOutlives(ty::OutlivesPredicate(a, b)) => {
                     a.is_param(index).then_some(b)
@@ -2094,7 +2092,11 @@ impl<'tcx> LateLintPass<'tcx> for ExplicitOutlivesRequirements {
                                 (
                                     Self::lifetimes_outliving_lifetime(
                                         cx.tcx,
-                                        inferred_outlives,
+                                        // don't warn if the inferred span actually came from the predicate we're looking at
+                                        // this happens if the type is recursively defined
+                                        inferred_outlives
+                                            .iter()
+                                            .filter(|(_, span)| !predicate.span.contains(*span)),
                                         item.owner_id.to_def_id(),
                                         region_def_id,
                                     ),
@@ -2116,7 +2118,14 @@ impl<'tcx> LateLintPass<'tcx> for ExplicitOutlivesRequirements {
                                     };
                                     let index = ty_generics.param_def_id_to_index[&def_id];
                                     (
-                                        Self::lifetimes_outliving_type(inferred_outlives, index),
+                                        Self::lifetimes_outliving_type(
+                                            // don't warn if the inferred span actually came from the predicate we're looking at
+                                            // this happens if the type is recursively defined
+                                            inferred_outlives.iter().filter(|(_, span)| {
+                                                !predicate.span.contains(*span)
+                                            }),
+                                            index,
+                                        ),
                                         &predicate.bounds,
                                         predicate.span,
                                         predicate.origin == PredicateOrigin::WhereClause,

compiler/rustc_middle/src/hir/map/mod.rs

@@ -1165,17 +1165,23 @@ fn hir_id_to_string(map: Map<'_>, id: HirId) -> String {
         }
         Node::ImplItem(ii) => {
             let kind = match ii.kind {
-                ImplItemKind::Const(..) => "assoc const",
-                ImplItemKind::Fn(..) => "method",
-                ImplItemKind::Type(_) => "assoc type",
+                ImplItemKind::Const(..) => "associated constant",
+                ImplItemKind::Fn(fn_sig, _) => match fn_sig.decl.implicit_self {
+                    ImplicitSelfKind::None => "associated function",
+                    _ => "method",
+                },
+                ImplItemKind::Type(_) => "associated type",
             };
             format!("{id} ({kind} `{}` in {})", ii.ident, path_str(ii.owner_id.def_id))
         }
         Node::TraitItem(ti) => {
             let kind = match ti.kind {
-                TraitItemKind::Const(..) => "assoc constant",
-                TraitItemKind::Fn(..) => "trait method",
-                TraitItemKind::Type(..) => "assoc type",
+                TraitItemKind::Const(..) => "associated constant",
+                TraitItemKind::Fn(fn_sig, _) => match fn_sig.decl.implicit_self {
+                    ImplicitSelfKind::None => "associated function",
+                    _ => "trait method",
+                },
+                TraitItemKind::Type(..) => "associated type",
             };
 
             format!("{id} ({kind} `{}` in {})", ti.ident, path_str(ti.owner_id.def_id))

compiler/rustc_middle/src/ty/assoc.rs

@@ -98,6 +98,15 @@ impl AssocItem {
         }
     }
 
+    pub fn descr(&self) -> &'static str {
+        match self.kind {
+            ty::AssocKind::Const => "const",
+            ty::AssocKind::Fn if self.fn_has_self_parameter => "method",
+            ty::AssocKind::Fn => "associated function",
+            ty::AssocKind::Type => "type",
+        }
+    }
+
     pub fn is_impl_trait_in_trait(&self) -> bool {
         self.opt_rpitit_info.is_some()
     }

library/alloc/src/slice.rs

@@ -178,15 +178,25 @@ impl<T> [T] {
     /// This sort is stable (i.e., does not reorder equal elements) and *O*(*n* \* log(*n*))
     /// worst-case.
     ///
-    /// If `T: Ord` does not implement a total order the resulting order is unspecified. All
-    /// original elements will remain in the slice and any possible modifications via interior
-    /// mutability are observed in the input. Same is true if `T: Ord` panics.
+    /// If the implementation of [`Ord`] for `T` does not implement a [total order] the resulting
+    /// order of elements in the slice is unspecified. All original elements will remain in the
+    /// slice and any possible modifications via interior mutability are observed in the input. Same
+    /// is true if the implementation of [`Ord`] for `T` panics.
     ///
     /// When applicable, unstable sorting is preferred because it is generally faster than stable
     /// sorting and it doesn't allocate auxiliary memory. See
     /// [`sort_unstable`](slice::sort_unstable). The exception are partially sorted slices, which
     /// may be better served with `slice::sort`.
     ///
+    /// Sorting types that only implement [`PartialOrd`] such as [`f32`] and [`f64`] require
+    /// additional precautions. For example, `f32::NAN != f32::NAN`, which doesn't fulfill the
+    /// reflexivity requirement of [`Ord`]. By using an alternative comparison function with
+    /// `slice::sort_by` such as [`f32::total_cmp`] or [`f64::total_cmp`] that defines a [total
+    /// order] users can sort slices containing floating-point values. Alternatively, if all values
+    /// in the slice are guaranteed to be in a subset for which [`PartialOrd::partial_cmp`] forms a
+    /// [total order], it's possible to sort the slice with `sort_by(|a, b|
+    /// a.partial_cmp(b).unwrap())`.
+    ///
     /// # Current implementation
     ///
     /// The current implementation is based on [driftsort] by Orson Peters and Lukas Bergdoll, which
@@ -198,18 +208,21 @@ impl<T> [T] {
     /// handled without allocation, medium sized slices allocate `self.len()` and beyond that it
     /// clamps at `self.len() / 2`.
     ///
-    /// If `T: Ord` does not implement a total order, the implementation may panic.
+    /// # Panics
+    ///
+    /// May panic if the implementation of [`Ord`] for `T` does not implement a [total order].
     ///
     /// # Examples
     ///
     /// ```
-    /// let mut v = [-5, 4, 1, -3, 2];
+    /// let mut v = [4, -5, 1, -3, 2];
     ///
     /// v.sort();
-    /// assert!(v == [-5, -3, 1, 2, 4]);
+    /// assert_eq!(v, [-5, -3, 1, 2, 4]);
     /// ```
     ///
     /// [driftsort]: https://github.com/Voultapher/driftsort
+    /// [total order]: https://en.wikipedia.org/wiki/Total_order
     #[cfg(not(no_global_oom_handling))]
     #[rustc_allow_incoherent_impl]
     #[stable(feature = "rust1", since = "1.0.0")]
@@ -221,30 +234,19 @@ impl<T> [T] {
         stable_sort(self, T::lt);
     }
 
-    /// Sorts the slice with a comparator function, preserving initial order of equal elements.
+    /// Sorts the slice with a comparison function, preserving initial order of equal elements.
     ///
     /// This sort is stable (i.e., does not reorder equal elements) and *O*(*n* \* log(*n*))
     /// worst-case.
     ///
-    /// The comparator function should define a total ordering for the elements in the slice. If the
-    /// ordering is not total, the order of the elements is unspecified.
-    ///
-    /// If the comparator function does not implement a total order the resulting order is
-    /// unspecified. All original elements will remain in the slice and any possible modifications
-    /// via interior mutability are observed in the input. Same is true if the comparator function
-    /// panics. A total order (for all `a`, `b` and `c`):
+    /// If the comparison function `compare` does not implement a [total order] the resulting order
+    /// of elements in the slice is unspecified. All original elements will remain in the slice and
+    /// any possible modifications via interior mutability are observed in the input. Same is true
+    /// if `compare` panics.
     ///
-    /// * total and antisymmetric: exactly one of `a < b`, `a == b` or `a > b` is true, and
-    /// * transitive, `a < b` and `b < c` implies `a < c`. The same must hold for both `==` and `>`.
-    ///
-    /// For example, while [`f64`] doesn't implement [`Ord`] because `NaN != NaN`, we can use
-    /// `partial_cmp` as our sort function when we know the slice doesn't contain a `NaN`.
-    ///
-    /// ```
-    /// let mut floats = [5f64, 4.0, 1.0, 3.0, 2.0];
-    /// floats.sort_unstable_by(|a, b| a.partial_cmp(b).unwrap());
-    /// assert_eq!(floats, [1.0, 2.0, 3.0, 4.0, 5.0]);
-    /// ```
+    /// For example `|a, b| (a - b).cmp(a)` is a comparison function that is neither transitive nor
+    /// reflexive nor total, `a < b < c < a` with `a = 1, b = 2, c = 3`. For more information and
+    /// examples see the [`Ord`] documentation.
     ///
     /// # Current implementation
     ///
@@ -257,21 +259,24 @@ impl<T> [T] {
     /// handled without allocation, medium sized slices allocate `self.len()` and beyond that it
     /// clamps at `self.len() / 2`.
     ///
-    /// If `T: Ord` does not implement a total order, the implementation may panic.
+    /// # Panics
+    ///
+    /// May panic if `compare` does not implement a [total order].
     ///
     /// # Examples
     ///
     /// ```
-    /// let mut v = [5, 4, 1, 3, 2];
+    /// let mut v = [4, -5, 1, -3, 2];
     /// v.sort_by(|a, b| a.cmp(b));
-    /// assert!(v == [1, 2, 3, 4, 5]);
+    /// assert_eq!(v, [-5, -3, 1, 2, 4]);
     ///
     /// // reverse sorting
     /// v.sort_by(|a, b| b.cmp(a));
-    /// assert!(v == [5, 4, 3, 2, 1]);
+    /// assert_eq!(v, [4, 2, 1, -3, -5]);
     /// ```
     ///
     /// [driftsort]: https://github.com/Voultapher/driftsort
+    /// [total order]: https://en.wikipedia.org/wiki/Total_order
     #[cfg(not(no_global_oom_handling))]
     #[rustc_allow_incoherent_impl]
     #[stable(feature = "rust1", since = "1.0.0")]
@@ -288,9 +293,10 @@ impl<T> [T] {
     /// This sort is stable (i.e., does not reorder equal elements) and *O*(*m* \* *n* \* log(*n*))
     /// worst-case, where the key function is *O*(*m*).
     ///
-    /// If `K: Ord` does not implement a total order the resulting order is unspecified.
-    /// All original elements will remain in the slice and any possible modifications via interior
-    /// mutability are observed in the input. Same is true if `K: Ord` panics.
+    /// If the implementation of [`Ord`] for `K` does not implement a [total order] the resulting
+    /// order of elements in the slice is unspecified. All original elements will remain in the
+    /// slice and any possible modifications via interior mutability are observed in the input. Same
+    /// is true if the implementation of [`Ord`] for `K` panics.
     ///
     /// # Current implementation
     ///
@@ -303,18 +309,21 @@ impl<T> [T] {
     /// handled without allocation, medium sized slices allocate `self.len()` and beyond that it
     /// clamps at `self.len() / 2`.
     ///
-    /// If `K: Ord` does not implement a total order, the implementation may panic.
+    /// # Panics
+    ///
+    /// May panic if the implementation of [`Ord`] for `K` does not implement a [total order].
     ///
     /// # Examples
     ///
     /// ```
-    /// let mut v = [-5i32, 4, 1, -3, 2];
+    /// let mut v = [4i32, -5, 1, -3, 2];
     ///
     /// v.sort_by_key(|k| k.abs());
-    /// assert!(v == [1, 2, -3, 4, -5]);
+    /// assert_eq!(v, [1, 2, -3, 4, -5]);
     /// ```
     ///
     /// [driftsort]: https://github.com/Voultapher/driftsort
+    /// [total order]: https://en.wikipedia.org/wiki/Total_order
     #[cfg(not(no_global_oom_handling))]
     #[rustc_allow_incoherent_impl]
     #[stable(feature = "slice_sort_by_key", since = "1.7.0")]
@@ -336,9 +345,10 @@ impl<T> [T] {
     /// storage to remember the results of key evaluation. The order of calls to the key function is
     /// unspecified and may change in future versions of the standard library.
     ///
-    /// If `K: Ord` does not implement a total order the resulting order is unspecified.
-    /// All original elements will remain in the slice and any possible modifications via interior
-    /// mutability are observed in the input. Same is true if `K: Ord` panics.
+    /// If the implementation of [`Ord`] for `K` does not implement a [total order] the resulting
+    /// order of elements in the slice is unspecified. All original elements will remain in the
+    /// slice and any possible modifications via interior mutability are observed in the input. Same
+    /// is true if the implementation of [`Ord`] for `K` panics.
     ///
     /// For simple key functions (e.g., functions that are property accesses or basic operations),
     /// [`sort_by_key`](slice::sort_by_key) is likely to be faster.
@@ -355,16 +365,22 @@ impl<T> [T] {
     /// In the worst case, the algorithm allocates temporary storage in a `Vec<(K, usize)>` the
     /// length of the slice.
     ///
+    /// # Panics
+    ///
+    /// May panic if the implementation of [`Ord`] for `K` does not implement a [total order].
+    ///
     /// # Examples
     ///
     /// ```
-    /// let mut v = [-5i32, 4, 32, -3, 2];
+    /// let mut v = [4i32, -5, 1, -3, 2, 10];
     ///
+    /// // Strings are sorted by lexicographical order.
     /// v.sort_by_cached_key(|k| k.to_string());
-    /// assert!(v == [-3, -5, 2, 32, 4]);
+    /// assert_eq!(v, [-3, -5, 1, 10, 2, 4]);
     /// ```
     ///
     /// [ipnsort]: https://github.com/Voultapher/sort-research-rs/tree/main/ipnsort
+    /// [total order]: https://en.wikipedia.org/wiki/Total_order
     #[cfg(not(no_global_oom_handling))]
     #[rustc_allow_incoherent_impl]
     #[stable(feature = "slice_sort_by_cached_key", since = "1.34.0")]