Rollup of 6 pull requests

compiler/rustc_ast_passes/src/feature_gate.rs

@@ -8,7 +8,7 @@ use rustc_feature::{Features, GateIssue};
 use rustc_session::parse::{feature_err, feature_err_issue};
 use rustc_session::Session;
 use rustc_span::source_map::Spanned;
-use rustc_span::symbol::{sym, Symbol};
+use rustc_span::symbol::sym;
 use rustc_span::Span;
 
 use tracing::debug;
@@ -328,17 +328,6 @@ impl<'a> Visitor<'a> for PostExpansionVisitor<'a> {
         }
     }
 
-    fn visit_name(&mut self, sp: Span, name: Symbol) {
-        if !name.as_str().is_ascii() {
-            gate_feature_post!(
-                &self,
-                non_ascii_idents,
-                self.sess.parse_sess.source_map().guess_head_span(sp),
-                "non-ascii idents are not fully supported"
-            );
-        }
-    }
-
     fn visit_item(&mut self, i: &'a ast::Item) {
         match i.kind {
             ast::ItemKind::ForeignMod(ref foreign_module) => {

compiler/rustc_error_codes/src/error_codes/E0554.md

@@ -4,8 +4,8 @@ beta compilers will not comply.
 Erroneous code example:
 
 ```ignore (depends on release channel)
-#![feature(non_ascii_idents)] // error: `#![feature]` may not be used on the
-                              //        stable release channel
+#![feature(lang_items)] // error: `#![feature]` may not be used on the
+                        //        stable release channel
 ```
 
 If you need the feature, make sure to use a nightly release of the compiler

compiler/rustc_error_codes/src/error_codes/E0754.md

@@ -3,7 +3,6 @@ A non-ASCII identifier was used in an invalid context.
 Erroneous code examples:
 
 ```compile_fail,E0754
-# #![feature(non_ascii_idents)]
 
 mod řųśť; // error!
 
@@ -17,8 +16,6 @@ Non-ASCII can be used as module names if it is inlined or if a `#[path]`
 attribute is specified. For example:
 
 ```
-# #![feature(non_ascii_idents)]
-
 mod řųśť { // ok!
     const IS_GREAT: bool = true;
 }

compiler/rustc_feature/src/accepted.rs

@@ -279,6 +279,8 @@ declare_features! (
     (accepted, unsafe_block_in_unsafe_fn, "1.52.0", Some(71668), None),
     /// Allows the use of or-patterns (e.g., `0 | 1`).
     (accepted, or_patterns, "1.53.0", Some(54883), None),
+    /// Allows defining identifiers beyond ASCII.
+    (accepted, non_ascii_idents, "1.53.0", Some(55467), None),
 
     // -------------------------------------------------------------------------
     // feature-group-end: accepted features

compiler/rustc_feature/src/active.rs

@@ -255,9 +255,6 @@ declare_features! (
     // feature-group-start: actual feature gates
     // -------------------------------------------------------------------------
 
-    /// Allows defining identifiers beyond ASCII.
-    (active, non_ascii_idents, "1.0.0", Some(55467), None),
-
     /// Allows using `#[plugin_registrar]` on functions.
     (active, plugin_registrar, "1.0.0", Some(29597), None),
 

compiler/rustc_lint/src/non_ascii_idents.rs

@@ -10,7 +10,6 @@ declare_lint! {
     ///
     /// ```rust,compile_fail
     /// # #![allow(unused)]
-    /// #![feature(non_ascii_idents)]
     /// #![deny(non_ascii_idents)]
     /// fn main() {
     ///     let föö = 1;
@@ -21,14 +20,11 @@ declare_lint! {
     ///
     /// ### Explanation
     ///
-    /// Currently on stable Rust, identifiers must contain ASCII characters.
-    /// The [`non_ascii_idents`] nightly-only feature allows identifiers to
-    /// contain non-ASCII characters. This lint allows projects that wish to
-    /// retain the limit of only using ASCII characters to switch this lint to
-    /// "forbid" (for example to ease collaboration or for security reasons).
+    /// This lint allows projects that wish to retain the limit of only using
+    /// ASCII characters to switch this lint to "forbid" (for example to ease
+    /// collaboration or for security reasons).
     /// See [RFC 2457] for more details.
     ///
-    /// [`non_ascii_idents`]: https://doc.rust-lang.org/nightly/unstable-book/language-features/non-ascii-idents.html
     /// [RFC 2457]: https://github.com/rust-lang/rfcs/blob/master/text/2457-non-ascii-idents.md
     pub NON_ASCII_IDENTS,
     Allow,
@@ -44,18 +40,15 @@ declare_lint! {
     ///
     /// ```rust
     /// # #![allow(unused)]
-    /// #![feature(non_ascii_idents)]
     /// const µ: f64 = 0.000001;
     /// ```
     ///
     /// {{produces}}
     ///
     /// ### Explanation
     ///
-    /// With the [`non_ascii_idents`] nightly-only feature enabled,
-    /// identifiers are allowed to use non-ASCII characters. This lint warns
-    /// about using characters which are not commonly used, and may cause
-    /// visual confusion.
+    /// This lint warns about using characters which are not commonly used, and may
+    /// cause visual confusion.
     ///
     /// This lint is triggered by identifiers that contain a codepoint that is
     /// not part of the set of "Allowed" codepoints as described by [Unicode®
@@ -66,7 +59,6 @@ declare_lint! {
     /// that if you "forbid" this lint that existing code may fail in the
     /// future.
     ///
-    /// [`non_ascii_idents`]: https://doc.rust-lang.org/nightly/unstable-book/language-features/non-ascii-idents.html
     /// [TR39Allowed]: https://www.unicode.org/reports/tr39/#General_Security_Profile
     pub UNCOMMON_CODEPOINTS,
     Warn,
@@ -81,8 +73,6 @@ declare_lint! {
     /// ### Example
     ///
     /// ```rust
-    /// #![feature(non_ascii_idents)]
-    ///
     /// // Latin Capital Letter E With Caron
     /// pub const Ě: i32 = 1;
     /// // Latin Capital Letter E With Breve
@@ -93,10 +83,8 @@ declare_lint! {
     ///
     /// ### Explanation
     ///
-    /// With the [`non_ascii_idents`] nightly-only feature enabled,
-    /// identifiers are allowed to use non-ASCII characters. This lint warns
-    /// when different identifiers may appear visually similar, which can
-    /// cause confusion.
+    /// This lint warns when different identifiers may appear visually similar,
+    /// which can cause confusion.
     ///
     /// The confusable detection algorithm is based on [Unicode® Technical
     /// Standard #39 Unicode Security Mechanisms Section 4 Confusable
@@ -110,7 +98,6 @@ declare_lint! {
     /// Beware that if you "forbid" this lint that existing code may fail in
     /// the future.
     ///
-    /// [`non_ascii_idents`]: https://doc.rust-lang.org/nightly/unstable-book/language-features/non-ascii-idents.html
     /// [TR39Confusable]: https://www.unicode.org/reports/tr39/#Confusable_Detection
     pub CONFUSABLE_IDENTS,
     Warn,
@@ -127,8 +114,6 @@ declare_lint! {
     /// ### Example
     ///
     /// ```rust
-    /// #![feature(non_ascii_idents)]
-    ///
     /// // The Japanese katakana character エ can be confused with the Han character 工.
     /// const エ: &'static str = "アイウ";
     /// ```
@@ -137,10 +122,8 @@ declare_lint! {
     ///
     /// ### Explanation
     ///
-    /// With the [`non_ascii_idents`] nightly-only feature enabled,
-    /// identifiers are allowed to use non-ASCII characters. This lint warns
-    /// when characters between different scripts may appear visually similar,
-    /// which can cause confusion.
+    /// This lint warns when characters between different scripts may appear
+    /// visually similar, which can cause confusion.
     ///
     /// If the crate contains other identifiers in the same script that have
     /// non-confusable characters, then this lint will *not* be issued. For
@@ -152,8 +135,6 @@ declare_lint! {
     /// Note that the set of confusable characters may change over time.
     /// Beware that if you "forbid" this lint that existing code may fail in
     /// the future.
-    ///
-    /// [`non_ascii_idents`]: https://doc.rust-lang.org/nightly/unstable-book/language-features/non-ascii-idents.html
     pub MIXED_SCRIPT_CONFUSABLES,
     Warn,
     "detects Unicode scripts whose mixed script confusables codepoints are solely used",

compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs

@@ -503,14 +503,14 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> {
                             let unit_obligation =
                                 obligation.with(predicate.without_const().to_predicate(tcx));
                             if self.predicate_may_hold(&unit_obligation) {
+                                err.note("this trait is implemented for `()`.");
                                 err.note(
-                                    "the trait is implemented for `()`. \
-                                     Possibly this error has been caused by changes to \
-                                     Rust's type-inference algorithm (see issue #48950 \
-                                     <https://github.com/rust-lang/rust/issues/48950> \
-                                     for more information). Consider whether you meant to use \
-                                     the type `()` here instead.",
+                                    "this error might have been caused by changes to \
+                                    Rust's type-inference algorithm (see issue #48950 \
+                                    <https://github.com/rust-lang/rust/issues/48950> \
+                                    for more information).",
                                 );
+                                err.help("did you intend to use the type `()` here instead?");
                             }
                         }
 

compiler/rustc_typeck/src/check/gather_locals.rs

@@ -6,20 +6,19 @@ use rustc_infer::infer::type_variable::{TypeVariableOrigin, TypeVariableOriginKi
 use rustc_middle::ty::Ty;
 use rustc_span::{sym, Span};
 use rustc_trait_selection::traits;
-use std::mem;
 
 pub(super) struct GatherLocalsVisitor<'a, 'tcx> {
     fcx: &'a FnCtxt<'a, 'tcx>,
     parent_id: hir::HirId,
     // parameters are special cases of patterns, but we want to handle them as
     // *distinct* cases. so track when we are hitting a pattern *within* an fn
     // parameter.
-    outermost_fn_param_pat: bool,
+    outermost_fn_param_pat: Option<Span>,
 }
 
 impl<'a, 'tcx> GatherLocalsVisitor<'a, 'tcx> {
     pub(super) fn new(fcx: &'a FnCtxt<'a, 'tcx>, parent_id: hir::HirId) -> Self {
-        Self { fcx, parent_id, outermost_fn_param_pat: false }
+        Self { fcx, parent_id, outermost_fn_param_pat: None }
     }
 
     fn assign(&mut self, span: Span, nid: hir::HirId, ty_opt: Option<LocalTy<'tcx>>) -> Ty<'tcx> {
@@ -92,7 +91,7 @@ impl<'a, 'tcx> Visitor<'tcx> for GatherLocalsVisitor<'a, 'tcx> {
     }
 
     fn visit_param(&mut self, param: &'tcx hir::Param<'tcx>) {
-        let old_outermost_fn_param_pat = mem::replace(&mut self.outermost_fn_param_pat, true);
+        let old_outermost_fn_param_pat = self.outermost_fn_param_pat.replace(param.ty_span);
         intravisit::walk_param(self, param);
         self.outermost_fn_param_pat = old_outermost_fn_param_pat;
     }
@@ -102,12 +101,12 @@ impl<'a, 'tcx> Visitor<'tcx> for GatherLocalsVisitor<'a, 'tcx> {
         if let PatKind::Binding(_, _, ident, _) = p.kind {
             let var_ty = self.assign(p.span, p.hir_id, None);
 
-            if self.outermost_fn_param_pat {
+            if let Some(ty_span) = self.outermost_fn_param_pat {
                 if !self.fcx.tcx.features().unsized_fn_params {
                     self.fcx.require_type_is_sized(
                         var_ty,
                         p.span,
-                        traits::SizedArgumentType(Some(p.span)),
+                        traits::SizedArgumentType(Some(ty_span)),
                     );
                 }
             } else {
@@ -123,7 +122,7 @@ impl<'a, 'tcx> Visitor<'tcx> for GatherLocalsVisitor<'a, 'tcx> {
                 var_ty
             );
         }
-        let old_outermost_fn_param_pat = mem::replace(&mut self.outermost_fn_param_pat, false);
+        let old_outermost_fn_param_pat = self.outermost_fn_param_pat.take();
         intravisit::walk_pat(self, p);
         self.outermost_fn_param_pat = old_outermost_fn_param_pat;
     }

library/alloc/src/vec/mod.rs

@@ -2041,7 +2041,7 @@ impl<T, A: Allocator> Vec<T, A> {
 
     /// Safety: changing returned .2 (&mut usize) is considered the same as calling `.set_len(_)`.
     ///
-    /// This method is used to have unique access to all vec parts at once in `extend_from_within`.
+    /// This method provides unique access to all vec parts at once in `extend_from_within`.
     unsafe fn split_at_spare_mut_with_len(
         &mut self,
     ) -> (&mut [T], &mut [MaybeUninit<T>], &mut usize) {
@@ -2279,7 +2279,7 @@ impl<T: Clone, A: Allocator> ExtendFromWithinSpec for Vec<T, A> {
         iter::zip(to_clone, spare)
             .map(|(src, dst)| dst.write(src.clone()))
             // Note:
-            // - Element was just initialized with `MaybeUninit::write`, so it's ok to increace len
+            // - Element was just initialized with `MaybeUninit::write`, so it's ok to increase len
             // - len is increased after each element to prevent leaks (see issue #82533)
             .for_each(|_| *len += 1);
     }