Rollup of 6 pull requests

compiler/rustc_borrowck/src/diagnostics/region_errors.rs

@@ -583,10 +583,12 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
         let err = FnMutError {
             span: *span,
             ty_err: match output_ty.kind() {
-                ty::Closure(_, _) => FnMutReturnTypeErr::ReturnClosure { span: *span },
                 ty::Generator(def, ..) if self.infcx.tcx.generator_is_async(*def) => {
                     FnMutReturnTypeErr::ReturnAsyncBlock { span: *span }
                 }
+                _ if output_ty.contains_closure() => {
+                    FnMutReturnTypeErr::ReturnClosure { span: *span }
+                }
                 _ => FnMutReturnTypeErr::ReturnRef { span: *span },
             },
         };
@@ -997,7 +999,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
     fn suggest_move_on_borrowing_closure(&self, diag: &mut Diagnostic) {
         let map = self.infcx.tcx.hir();
         let body_id = map.body_owned_by(self.mir_def_id());
-        let expr = &map.body(body_id).value;
+        let expr = &map.body(body_id).value.peel_blocks();
         let mut closure_span = None::<rustc_span::Span>;
         match expr.kind {
             hir::ExprKind::MethodCall(.., args, _) => {
@@ -1012,20 +1014,14 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
                     }
                 }
             }
-            hir::ExprKind::Block(blk, _) => {
-                if let Some(expr) = blk.expr {
-                    // only when the block is a closure
-                    if let hir::ExprKind::Closure(hir::Closure {
-                        capture_clause: hir::CaptureBy::Ref,
-                        body,
-                        ..
-                    }) = expr.kind
-                    {
-                        let body = map.body(*body);
-                        if !matches!(body.generator_kind, Some(hir::GeneratorKind::Async(..))) {
-                            closure_span = Some(expr.span.shrink_to_lo());
-                        }
-                    }
+            hir::ExprKind::Closure(hir::Closure {
+                capture_clause: hir::CaptureBy::Ref,
+                body,
+                ..
+            }) => {
+                let body = map.body(*body);
+                if !matches!(body.generator_kind, Some(hir::GeneratorKind::Async(..))) {
+                    closure_span = Some(expr.span.shrink_to_lo());
                 }
             }
             _ => {}

compiler/rustc_middle/src/ty/sty.rs

@@ -2043,6 +2043,28 @@ impl<'tcx> Ty<'tcx> {
         cf.is_break()
     }
 
+    /// Checks whether a type recursively contains any closure
+    ///
+    /// Example: `Option<[[email protected]:4:20]>` returns true
+    pub fn contains_closure(self) -> bool {
+        struct ContainsClosureVisitor;
+
+        impl<'tcx> TypeVisitor<'tcx> for ContainsClosureVisitor {
+            type BreakTy = ();
+
+            fn visit_ty(&mut self, t: Ty<'tcx>) -> ControlFlow<Self::BreakTy> {
+                if let ty::Closure(_, _) = t.kind() {
+                    ControlFlow::Break(())
+                } else {
+                    t.super_visit_with(self)
+                }
+            }
+        }
+
+        let cf = self.visit_with(&mut ContainsClosureVisitor);
+        cf.is_break()
+    }
+
     /// Returns the type and mutability of `*ty`.
     ///
     /// The parameter `explicit` indicates if this is an *explicit* dereference.

compiler/rustc_parse/src/parser/diagnostics.rs

@@ -2405,26 +2405,42 @@ impl<'a> Parser<'a> {
         if !matches!(first_pat.kind, PatKind::Ident(_, _, None) | PatKind::Path(..))
             || !self.look_ahead(1, |token| token.is_ident() && !token.is_reserved_ident())
         {
+            let mut snapshot_type = self.create_snapshot_for_diagnostic();
+            snapshot_type.bump(); // `:`
+            match snapshot_type.parse_ty() {
+                Err(inner_err) => {
+                    inner_err.cancel();
+                }
+                Ok(ty) => {
+                    let Err(mut err) = self.expected_one_of_not_found(&[], &[]) else {
+                        return first_pat;
+                    };
+                    err.span_label(ty.span, "specifying the type of a pattern isn't supported");
+                    self.restore_snapshot(snapshot_type);
+                    let span = first_pat.span.to(ty.span);
+                    first_pat = self.mk_pat(span, PatKind::Wild);
+                    err.emit();
+                }
+            }
             return first_pat;
         }
         // The pattern looks like it might be a path with a `::` -> `:` typo:
         // `match foo { bar:baz => {} }`
-        let span = self.token.span;
+        let colon_span = self.token.span;
         // We only emit "unexpected `:`" error here if we can successfully parse the
         // whole pattern correctly in that case.
-        let snapshot = self.create_snapshot_for_diagnostic();
+        let mut snapshot_pat = self.create_snapshot_for_diagnostic();
+        let mut snapshot_type = self.create_snapshot_for_diagnostic();
 
         // Create error for "unexpected `:`".
         match self.expected_one_of_not_found(&[], &[]) {
             Err(mut err) => {
-                self.bump(); // Skip the `:`.
-                match self.parse_pat_no_top_alt(expected) {
+                // Skip the `:`.
+                snapshot_pat.bump();
+                snapshot_type.bump();
+                match snapshot_pat.parse_pat_no_top_alt(expected) {
                     Err(inner_err) => {
-                        // Carry on as if we had not done anything, callers will emit a
-                        // reasonable error.
                         inner_err.cancel();
-                        err.cancel();
-                        self.restore_snapshot(snapshot);
                     }
                     Ok(mut pat) => {
                         // We've parsed the rest of the pattern.
@@ -2488,22 +2504,33 @@ impl<'a> Parser<'a> {
                             _ => {}
                         }
                         if show_sugg {
-                            err.span_suggestion(
-                                span,
+                            err.span_suggestion_verbose(
+                                colon_span.until(self.look_ahead(1, |t| t.span)),
                                 "maybe write a path separator here",
                                 "::",
                                 Applicability::MaybeIncorrect,
                             );
                         } else {
                             first_pat = self.mk_pat(new_span, PatKind::Wild);
                         }
-                        err.emit();
+                        self.restore_snapshot(snapshot_pat);
                     }
                 }
+                match snapshot_type.parse_ty() {
+                    Err(inner_err) => {
+                        inner_err.cancel();
+                    }
+                    Ok(ty) => {
+                        err.span_label(ty.span, "specifying the type of a pattern isn't supported");
+                        self.restore_snapshot(snapshot_type);
+                        let new_span = first_pat.span.to(ty.span);
+                        first_pat = self.mk_pat(new_span, PatKind::Wild);
+                    }
+                }
+                err.emit();
             }
             _ => {
                 // Carry on as if we had not done anything. This should be unreachable.
-                self.restore_snapshot(snapshot);
             }
         };
         first_pat

compiler/rustc_parse_format/src/lib.rs

@@ -273,7 +273,13 @@ impl<'a> Iterator for Parser<'a> {
                                 );
                             }
                         } else {
-                            self.suggest_positional_arg_instead_of_captured_arg(arg);
+                            if let Some(&(_, maybe)) = self.cur.peek() {
+                                if maybe == '?' {
+                                    self.suggest_format();
+                                } else {
+                                    self.suggest_positional_arg_instead_of_captured_arg(arg);
+                                }
+                            }
                         }
                         Some(NextArgument(Box::new(arg)))
                     }
@@ -832,6 +838,27 @@ impl<'a> Parser<'a> {
         if found { Some(cur) } else { None }
     }
 
+    fn suggest_format(&mut self) {
+        if let (Some(pos), Some(_)) = (self.consume_pos('?'), self.consume_pos(':')) {
+            let word = self.word();
+            let _end = self.current_pos();
+            let pos = self.to_span_index(pos);
+            self.errors.insert(
+                0,
+                ParseError {
+                    description: "expected format parameter to occur after `:`".to_owned(),
+                    note: Some(
+                        format!("`?` comes after `:`, try `{}:{}` instead", word, "?").to_owned(),
+                    ),
+                    label: "expected `?` to occur after `:`".to_owned(),
+                    span: pos.to(pos),
+                    secondary_label: None,
+                    should_be_replaced_with_positional_argument: false,
+                },
+            );
+        }
+    }
+
     fn suggest_positional_arg_instead_of_captured_arg(&mut self, arg: Argument<'a>) {
         if let Some(end) = self.consume_pos('.') {
             let byte_pos = self.to_span_index(end);

library/core/benches/char/methods.rs

@@ -1,26 +1,26 @@
-use test::Bencher;
+use test::{black_box, Bencher};
 
 const CHARS: [char; 9] = ['0', 'x', '2', '5', 'A', 'f', '7', '8', '9'];
 const RADIX: [u32; 5] = [2, 8, 10, 16, 32];
 
 #[bench]
 fn bench_to_digit_radix_2(b: &mut Bencher) {
-    b.iter(|| CHARS.iter().cycle().take(10_000).map(|c| c.to_digit(2)).min())
+    b.iter(|| CHARS.iter().cycle().take(10_000).map(|c| black_box(c).to_digit(2)).min())
 }
 
 #[bench]
 fn bench_to_digit_radix_10(b: &mut Bencher) {
-    b.iter(|| CHARS.iter().cycle().take(10_000).map(|c| c.to_digit(10)).min())
+    b.iter(|| CHARS.iter().cycle().take(10_000).map(|c| black_box(c).to_digit(10)).min())
 }
 
 #[bench]
 fn bench_to_digit_radix_16(b: &mut Bencher) {
-    b.iter(|| CHARS.iter().cycle().take(10_000).map(|c| c.to_digit(16)).min())
+    b.iter(|| CHARS.iter().cycle().take(10_000).map(|c| black_box(c).to_digit(16)).min())
 }
 
 #[bench]
 fn bench_to_digit_radix_36(b: &mut Bencher) {
-    b.iter(|| CHARS.iter().cycle().take(10_000).map(|c| c.to_digit(36)).min())
+    b.iter(|| CHARS.iter().cycle().take(10_000).map(|c| black_box(c).to_digit(36)).min())
 }
 
 #[bench]
@@ -31,47 +31,59 @@ fn bench_to_digit_radix_var(b: &mut Bencher) {
             .cycle()
             .zip(RADIX.iter().cycle())
             .take(10_000)
-            .map(|(c, radix)| c.to_digit(*radix))
+            .map(|(c, radix)| black_box(c).to_digit(*radix))
             .min()
     })
 }
 
 #[bench]
 fn bench_to_ascii_uppercase(b: &mut Bencher) {
-    b.iter(|| CHARS.iter().cycle().take(10_000).map(|c| c.to_ascii_uppercase()).min())
+    b.iter(|| CHARS.iter().cycle().take(10_000).map(|c| black_box(c).to_ascii_uppercase()).min())
 }
 
 #[bench]
 fn bench_to_ascii_lowercase(b: &mut Bencher) {
-    b.iter(|| CHARS.iter().cycle().take(10_000).map(|c| c.to_ascii_lowercase()).min())
+    b.iter(|| CHARS.iter().cycle().take(10_000).map(|c| black_box(c).to_ascii_lowercase()).min())
 }
 
 #[bench]
 fn bench_ascii_mix_to_uppercase(b: &mut Bencher) {
-    b.iter(|| (0..=255).cycle().take(10_000).map(|b| char::from(b).to_uppercase()).count())
+    b.iter(|| {
+        (0..=255).cycle().take(10_000).map(|b| black_box(char::from(b)).to_uppercase()).count()
+    })
 }
 
 #[bench]
 fn bench_ascii_mix_to_lowercase(b: &mut Bencher) {
-    b.iter(|| (0..=255).cycle().take(10_000).map(|b| char::from(b).to_lowercase()).count())
+    b.iter(|| {
+        (0..=255).cycle().take(10_000).map(|b| black_box(char::from(b)).to_lowercase()).count()
+    })
 }
 
 #[bench]
 fn bench_ascii_char_to_uppercase(b: &mut Bencher) {
-    b.iter(|| (0..=127).cycle().take(10_000).map(|b| char::from(b).to_uppercase()).count())
+    b.iter(|| {
+        (0..=127).cycle().take(10_000).map(|b| black_box(char::from(b)).to_uppercase()).count()
+    })
 }
 
 #[bench]
 fn bench_ascii_char_to_lowercase(b: &mut Bencher) {
-    b.iter(|| (0..=127).cycle().take(10_000).map(|b| char::from(b).to_lowercase()).count())
+    b.iter(|| {
+        (0..=127).cycle().take(10_000).map(|b| black_box(char::from(b)).to_lowercase()).count()
+    })
 }
 
 #[bench]
 fn bench_non_ascii_char_to_uppercase(b: &mut Bencher) {
-    b.iter(|| (128..=255).cycle().take(10_000).map(|b| char::from(b).to_uppercase()).count())
+    b.iter(|| {
+        (128..=255).cycle().take(10_000).map(|b| black_box(char::from(b)).to_uppercase()).count()
+    })
 }
 
 #[bench]
 fn bench_non_ascii_char_to_lowercase(b: &mut Bencher) {
-    b.iter(|| (128..=255).cycle().take(10_000).map(|b| char::from(b).to_lowercase()).count())
+    b.iter(|| {
+        (128..=255).cycle().take(10_000).map(|b| black_box(char::from(b)).to_lowercase()).count()
+    })
 }

library/core/benches/num/flt2dec/strategy/dragon.rs

@@ -1,14 +1,14 @@
 use super::super::*;
 use core::num::flt2dec::strategy::dragon::*;
 use std::mem::MaybeUninit;
-use test::Bencher;
+use test::{black_box, Bencher};
 
 #[bench]
 fn bench_small_shortest(b: &mut Bencher) {
     let decoded = decode_finite(3.141592f64);
     let mut buf = [MaybeUninit::new(0); MAX_SIG_DIGITS];
     b.iter(|| {
-        format_shortest(&decoded, &mut buf);
+        format_shortest(black_box(&decoded), &mut buf);
     });
 }
 
@@ -17,7 +17,7 @@ fn bench_big_shortest(b: &mut Bencher) {
     let decoded = decode_finite(f64::MAX);
     let mut buf = [MaybeUninit::new(0); MAX_SIG_DIGITS];
     b.iter(|| {
-        format_shortest(&decoded, &mut buf);
+        format_shortest(black_box(&decoded), &mut buf);
     });
 }
 
@@ -26,7 +26,7 @@ fn bench_small_exact_3(b: &mut Bencher) {
     let decoded = decode_finite(3.141592f64);
     let mut buf = [MaybeUninit::new(0); 3];
     b.iter(|| {
-        format_exact(&decoded, &mut buf, i16::MIN);
+        format_exact(black_box(&decoded), &mut buf, i16::MIN);
     });
 }
 
@@ -35,7 +35,7 @@ fn bench_big_exact_3(b: &mut Bencher) {
     let decoded = decode_finite(f64::MAX);
     let mut buf = [MaybeUninit::new(0); 3];
     b.iter(|| {
-        format_exact(&decoded, &mut buf, i16::MIN);
+        format_exact(black_box(&decoded), &mut buf, i16::MIN);
     });
 }
 
@@ -44,7 +44,7 @@ fn bench_small_exact_12(b: &mut Bencher) {
     let decoded = decode_finite(3.141592f64);
     let mut buf = [MaybeUninit::new(0); 12];
     b.iter(|| {
-        format_exact(&decoded, &mut buf, i16::MIN);
+        format_exact(black_box(&decoded), &mut buf, i16::MIN);
     });
 }
 
@@ -53,7 +53,7 @@ fn bench_big_exact_12(b: &mut Bencher) {
     let decoded = decode_finite(f64::MAX);
     let mut buf = [MaybeUninit::new(0); 12];
     b.iter(|| {
-        format_exact(&decoded, &mut buf, i16::MIN);
+        format_exact(black_box(&decoded), &mut buf, i16::MIN);
     });
 }
 
@@ -62,7 +62,7 @@ fn bench_small_exact_inf(b: &mut Bencher) {
     let decoded = decode_finite(3.141592f64);
     let mut buf = [MaybeUninit::new(0); 1024];
     b.iter(|| {
-        format_exact(&decoded, &mut buf, i16::MIN);
+        format_exact(black_box(&decoded), &mut buf, i16::MIN);
     });
 }
 
@@ -71,6 +71,6 @@ fn bench_big_exact_inf(b: &mut Bencher) {
     let decoded = decode_finite(f64::MAX);
     let mut buf = [MaybeUninit::new(0); 1024];
     b.iter(|| {
-        format_exact(&decoded, &mut buf, i16::MIN);
+        format_exact(black_box(&decoded), &mut buf, i16::MIN);
     });
 }