Auto merge of #99267 - Dylan-DPC:rollup-d8l7y1o, r=Dylan-DPC

Rollup of 6 pull requests

Successful merges:

 - #99113 (Simplify [a]rc code a little)
 - #99131 (Add label for generic arg (+ APIT) and RPIT callables in `label_fn_like`)
 - #99237 (removed unused CSS and unused HTML IDs)
 - #99239 (Add myself to the set of people notified when MIR changes.)
 - #99241 (Remove comment referring to constness.rs)
 - #99257 (Add regression test for #89436)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup

compiler/rustc_const_eval/src/interpret/intrinsics.rs

@@ -132,8 +132,6 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
             Some(p) => p,
         };
 
-        // Keep the patterns in this match ordered the same as the list in
-        // `src/librustc_middle/ty/constness.rs`
         match intrinsic_name {
             sym::caller_location => {
                 let span = self.find_closest_untracked_caller_location();

compiler/rustc_middle/src/ty/closure.rs

@@ -128,6 +128,14 @@ impl<'tcx> ClosureKind {
             None
         }
     }
+
+    pub fn to_def_id(&self, tcx: TyCtxt<'_>) -> DefId {
+        match self {
+            ClosureKind::Fn => tcx.lang_items().fn_once_trait().unwrap(),
+            ClosureKind::FnMut => tcx.lang_items().fn_mut_trait().unwrap(),
+            ClosureKind::FnOnce => tcx.lang_items().fn_trait().unwrap(),
+        }
+    }
 }
 
 /// A composite describing a `Place` that is captured by a closure.

compiler/rustc_typeck/src/check/fn_ctxt/checks.rs

@@ -21,15 +21,18 @@ use rustc_hir::def_id::DefId;
 use rustc_hir::{ExprKind, Node, QPath};
 use rustc_index::vec::IndexVec;
 use rustc_infer::infer::error_reporting::{FailureCode, ObligationCauseExt};
+use rustc_infer::infer::type_variable::{TypeVariableOrigin, TypeVariableOriginKind};
 use rustc_infer::infer::InferOk;
 use rustc_infer::infer::TypeTrace;
 use rustc_middle::ty::adjustment::AllowTwoPhase;
 use rustc_middle::ty::visit::TypeVisitable;
-use rustc_middle::ty::{self, IsSuggestable, Ty, TyCtxt};
+use rustc_middle::ty::{self, DefIdTree, IsSuggestable, Ty};
 use rustc_session::Session;
 use rustc_span::symbol::Ident;
 use rustc_span::{self, Span};
-use rustc_trait_selection::traits::{self, ObligationCauseCode, StatementAsExpression};
+use rustc_trait_selection::traits::{
+    self, ObligationCauseCode, SelectionContext, StatementAsExpression,
+};
 
 use std::iter;
 use std::slice;
@@ -89,7 +92,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 args_no_rcvr,
                 false,
                 tuple_arguments,
-                None,
+                method.ok().map(|method| method.def_id),
             );
             return self.tcx.ty_error();
         }
@@ -393,41 +396,6 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         }
 
         if !call_appears_satisfied {
-            // Next, let's construct the error
-            let (error_span, full_call_span, ctor_of) = match &call_expr.kind {
-                hir::ExprKind::Call(
-                    hir::Expr {
-                        span,
-                        kind:
-                            hir::ExprKind::Path(hir::QPath::Resolved(
-                                _,
-                                hir::Path { res: Res::Def(DefKind::Ctor(of, _), _), .. },
-                            )),
-                        ..
-                    },
-                    _,
-                ) => (call_span, *span, Some(of)),
-                hir::ExprKind::Call(hir::Expr { span, .. }, _) => (call_span, *span, None),
-                hir::ExprKind::MethodCall(path_segment, _, span) => {
-                    let ident_span = path_segment.ident.span;
-                    let ident_span = if let Some(args) = path_segment.args {
-                        ident_span.with_hi(args.span_ext.hi())
-                    } else {
-                        ident_span
-                    };
-                    (
-                        *span, ident_span, None, // methods are never ctors
-                    )
-                }
-                k => span_bug!(call_span, "checking argument types on a non-call: `{:?}`", k),
-            };
-            let args_span = error_span.trim_start(full_call_span).unwrap_or(error_span);
-            let call_name = match ctor_of {
-                Some(CtorOf::Struct) => "struct",
-                Some(CtorOf::Variant) => "enum variant",
-                None => "function",
-            };
-
             let compatibility_diagonal = IndexVec::from_raw(compatibility_diagonal);
             let provided_args = IndexVec::from_iter(provided_args.iter().take(if c_variadic {
                 minimum_input_count
@@ -451,13 +419,11 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 compatibility_diagonal,
                 formal_and_expected_inputs,
                 provided_args,
-                full_call_span,
-                error_span,
-                args_span,
-                call_name,
                 c_variadic,
                 err_code,
                 fn_def_id,
+                call_span,
+                call_expr,
             );
         }
     }
@@ -467,14 +433,47 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         compatibility_diagonal: IndexVec<ProvidedIdx, Compatibility<'tcx>>,
         formal_and_expected_inputs: IndexVec<ExpectedIdx, (Ty<'tcx>, Ty<'tcx>)>,
         provided_args: IndexVec<ProvidedIdx, &'tcx hir::Expr<'tcx>>,
-        full_call_span: Span,
-        error_span: Span,
-        args_span: Span,
-        call_name: &str,
         c_variadic: bool,
         err_code: &str,
         fn_def_id: Option<DefId>,
+        call_span: Span,
+        call_expr: &hir::Expr<'tcx>,
     ) {
+        // Next, let's construct the error
+        let (error_span, full_call_span, ctor_of) = match &call_expr.kind {
+            hir::ExprKind::Call(
+                hir::Expr {
+                    span,
+                    kind:
+                        hir::ExprKind::Path(hir::QPath::Resolved(
+                            _,
+                            hir::Path { res: Res::Def(DefKind::Ctor(of, _), _), .. },
+                        )),
+                    ..
+                },
+                _,
+            ) => (call_span, *span, Some(of)),
+            hir::ExprKind::Call(hir::Expr { span, .. }, _) => (call_span, *span, None),
+            hir::ExprKind::MethodCall(path_segment, _, span) => {
+                let ident_span = path_segment.ident.span;
+                let ident_span = if let Some(args) = path_segment.args {
+                    ident_span.with_hi(args.span_ext.hi())
+                } else {
+                    ident_span
+                };
+                (
+                    *span, ident_span, None, // methods are never ctors
+                )
+            }
+            k => span_bug!(call_span, "checking argument types on a non-call: `{:?}`", k),
+        };
+        let args_span = error_span.trim_start(full_call_span).unwrap_or(error_span);
+        let call_name = match ctor_of {
+            Some(CtorOf::Struct) => "struct",
+            Some(CtorOf::Variant) => "enum variant",
+            None => "function",
+        };
+
         // Don't print if it has error types or is just plain `_`
         fn has_error_or_infer<'tcx>(tys: impl IntoIterator<Item = Ty<'tcx>>) -> bool {
             tys.into_iter().any(|ty| ty.references_error() || ty.is_ty_var())
@@ -495,6 +494,23 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 (self.resolve_vars_if_possible(ty), expr.span)
             })
             .collect();
+        let callee_expr = match &call_expr.peel_blocks().kind {
+            hir::ExprKind::Call(callee, _) => Some(*callee),
+            hir::ExprKind::MethodCall(_, callee, _) => {
+                if let Some((DefKind::AssocFn, def_id)) =
+                    self.typeck_results.borrow().type_dependent_def(call_expr.hir_id)
+                    && let Some(assoc) = tcx.opt_associated_item(def_id)
+                    && assoc.fn_has_self_parameter
+                {
+                    Some(&callee[0])
+                } else {
+                    None
+                }
+            }
+            _ => None,
+        };
+        let callee_ty = callee_expr
+            .and_then(|callee_expr| self.typeck_results.borrow().expr_ty_adjusted_opt(callee_expr));
 
         // A "softer" version of the `demand_compatible`, which checks types without persisting them,
         // and treats error types differently
@@ -631,7 +647,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                             Applicability::MachineApplicable,
                         );
                     };
-                    label_fn_like(tcx, &mut err, fn_def_id);
+                    self.label_fn_like(&mut err, fn_def_id, callee_ty);
                     err.emit();
                     return;
                 }
@@ -721,7 +737,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 format!("arguments to this {} are incorrect", call_name),
             );
             // Call out where the function is defined
-            label_fn_like(tcx, &mut err, fn_def_id);
+            self.label_fn_like(&mut err, fn_def_id, callee_ty);
             err.emit();
             return;
         }
@@ -1003,7 +1019,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         }
 
         // Call out where the function is defined
-        label_fn_like(tcx, &mut err, fn_def_id);
+        self.label_fn_like(&mut err, fn_def_id, callee_ty);
 
         // And add a suggestion block for all of the parameters
         let suggestion_text = match suggestion_text {
@@ -1795,47 +1811,126 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             }
         }
     }
-}
 
-fn label_fn_like<'tcx>(
-    tcx: TyCtxt<'tcx>,
-    err: &mut rustc_errors::DiagnosticBuilder<'tcx, rustc_errors::ErrorGuaranteed>,
-    def_id: Option<DefId>,
-) {
-    let Some(def_id) = def_id else {
-        return;
-    };
+    fn label_fn_like(
+        &self,
+        err: &mut rustc_errors::DiagnosticBuilder<'tcx, rustc_errors::ErrorGuaranteed>,
+        callable_def_id: Option<DefId>,
+        callee_ty: Option<Ty<'tcx>>,
+    ) {
+        let Some(mut def_id) = callable_def_id else {
+            return;
+        };
 
-    if let Some(def_span) = tcx.def_ident_span(def_id) {
-        let mut spans: MultiSpan = def_span.into();
-
-        let params = tcx
-            .hir()
-            .get_if_local(def_id)
-            .and_then(|node| node.body_id())
-            .into_iter()
-            .flat_map(|id| tcx.hir().body(id).params);
-
-        for param in params {
-            spans.push_span_label(param.span, "");
+        if let Some(assoc_item) = self.tcx.opt_associated_item(def_id)
+            // Possibly points at either impl or trait item, so try to get it
+            // to point to trait item, then get the parent.
+            // This parent might be an impl in the case of an inherent function,
+            // but the next check will fail.
+            && let maybe_trait_item_def_id = assoc_item.trait_item_def_id.unwrap_or(def_id)
+            && let maybe_trait_def_id = self.tcx.parent(maybe_trait_item_def_id)
+            // Just an easy way to check "trait_def_id == Fn/FnMut/FnOnce"
+            && let Some(call_kind) = ty::ClosureKind::from_def_id(self.tcx, maybe_trait_def_id)
+            && let Some(callee_ty) = callee_ty
+        {
+            let callee_ty = callee_ty.peel_refs();
+            match *callee_ty.kind() {
+                ty::Param(param) => {
+                    let param =
+                        self.tcx.generics_of(self.body_id.owner).type_param(&param, self.tcx);
+                    if param.kind.is_synthetic() {
+                        // if it's `impl Fn() -> ..` then just fall down to the def-id based logic
+                        def_id = param.def_id;
+                    } else {
+                        // Otherwise, find the predicate that makes this generic callable,
+                        // and point at that.
+                        let instantiated = self
+                            .tcx
+                            .explicit_predicates_of(self.body_id.owner)
+                            .instantiate_identity(self.tcx);
+                        // FIXME(compiler-errors): This could be problematic if something has two
+                        // fn-like predicates with different args, but callable types really never
+                        // do that, so it's OK.
+                        for (predicate, span) in
+                            std::iter::zip(instantiated.predicates, instantiated.spans)
+                        {
+                            if let ty::PredicateKind::Trait(pred) = predicate.kind().skip_binder()
+                                && pred.self_ty().peel_refs() == callee_ty
+                                && ty::ClosureKind::from_def_id(self.tcx, pred.def_id()).is_some()
+                            {
+                                err.span_note(span, "callable defined here");
+                                return;
+                            }
+                        }
+                    }
+                }
+                ty::Opaque(new_def_id, _)
+                | ty::Closure(new_def_id, _)
+                | ty::FnDef(new_def_id, _) => {
+                    def_id = new_def_id;
+                }
+                _ => {
+                    // Look for a user-provided impl of a `Fn` trait, and point to it.
+                    let new_def_id = self.probe(|_| {
+                        let trait_ref = ty::TraitRef::new(
+                            call_kind.to_def_id(self.tcx),
+                            self.tcx.mk_substs([
+                                ty::GenericArg::from(callee_ty),
+                                self.next_ty_var(TypeVariableOrigin {
+                                    kind: TypeVariableOriginKind::MiscVariable,
+                                    span: rustc_span::DUMMY_SP,
+                                })
+                                .into(),
+                            ].into_iter()),
+                        );
+                        let obligation = traits::Obligation::new(
+                            traits::ObligationCause::dummy(),
+                            self.param_env,
+                            ty::Binder::dummy(ty::TraitPredicate {
+                                trait_ref,
+                                constness: ty::BoundConstness::NotConst,
+                                polarity: ty::ImplPolarity::Positive,
+                            }),
+                        );
+                        match SelectionContext::new(&self).select(&obligation) {
+                            Ok(Some(traits::ImplSource::UserDefined(impl_source))) => {
+                                Some(impl_source.impl_def_id)
+                            }
+                            _ => None
+                        }
+                    });
+                    if let Some(new_def_id) = new_def_id {
+                        def_id = new_def_id;
+                    } else {
+                        return;
+                    }
+                }
+            }
         }
 
-        let def_kind = tcx.def_kind(def_id);
-        err.span_note(spans, &format!("{} defined here", def_kind.descr(def_id)));
-    } else {
-        match tcx.hir().get_if_local(def_id) {
-            Some(hir::Node::Expr(hir::Expr {
-                kind: hir::ExprKind::Closure(hir::Closure { fn_decl_span, .. }),
-                ..
-            })) => {
-                let spans: MultiSpan = (*fn_decl_span).into();
+        if let Some(def_span) = self.tcx.def_ident_span(def_id) && !def_span.is_dummy() {
+            let mut spans: MultiSpan = def_span.into();
 
-                // Note: We don't point to param spans here because they overlap
-                // with the closure span itself
+            let params = self
+                .tcx
+                .hir()
+                .get_if_local(def_id)
+                .and_then(|node| node.body_id())
+                .into_iter()
+                .flat_map(|id| self.tcx.hir().body(id).params);
 
-                err.span_note(spans, "closure defined here");
+            for param in params {
+                spans.push_span_label(param.span, "");
             }
-            _ => {}
+
+            let def_kind = self.tcx.def_kind(def_id);
+            err.span_note(spans, &format!("{} defined here", def_kind.descr(def_id)));
+        } else {
+            let def_kind = self.tcx.def_kind(def_id);
+            err.span_note(
+                self.tcx.def_span(def_id),
+                &format!("{} defined here", def_kind.descr(def_id)),
+            );
         }
     }
 }

library/alloc/src/lib.rs

@@ -124,6 +124,7 @@
 #![cfg_attr(test, feature(new_uninit))]
 #![feature(nonnull_slice_from_raw_parts)]
 #![feature(pattern)]
+#![feature(pointer_byte_offsets)]
 #![feature(ptr_internals)]
 #![feature(ptr_metadata)]
 #![feature(ptr_sub_ptr)]

library/alloc/src/rc.rs

@@ -907,8 +907,7 @@ impl<T: ?Sized> Rc<T> {
         let offset = unsafe { data_offset(ptr) };
 
         // Reverse the offset to find the original RcBox.
-        let rc_ptr =
-            unsafe { (ptr as *mut u8).offset(-offset).with_metadata_of(ptr as *mut RcBox<T>) };
+        let rc_ptr = unsafe { ptr.byte_sub(offset) as *mut RcBox<T> };
 
         unsafe { Self::from_ptr(rc_ptr) }
     }
@@ -2331,7 +2330,7 @@ impl<T: ?Sized> Weak<T> {
             let offset = unsafe { data_offset(ptr) };
             // Thus, we reverse the offset to get the whole RcBox.
             // SAFETY: the pointer originated from a Weak, so this offset is safe.
-            unsafe { (ptr as *mut u8).offset(-offset).with_metadata_of(ptr as *mut RcBox<T>) }
+            unsafe { ptr.byte_sub(offset) as *mut RcBox<T> }
         };
 
         // SAFETY: we now have recovered the original Weak pointer, so can create the Weak.
@@ -2684,7 +2683,7 @@ impl<T: ?Sized> Unpin for Rc<T> {}
 ///
 /// The pointer must point to (and have valid metadata for) a previously
 /// valid instance of T, but the T is allowed to be dropped.
-unsafe fn data_offset<T: ?Sized>(ptr: *const T) -> isize {
+unsafe fn data_offset<T: ?Sized>(ptr: *const T) -> usize {
     // Align the unsized value to the end of the RcBox.
     // Because RcBox is repr(C), it will always be the last field in memory.
     // SAFETY: since the only unsized types possible are slices, trait objects,
@@ -2695,7 +2694,7 @@ unsafe fn data_offset<T: ?Sized>(ptr: *const T) -> isize {
 }
 
 #[inline]
-fn data_offset_align(align: usize) -> isize {
+fn data_offset_align(align: usize) -> usize {
     let layout = Layout::new::<RcBox<()>>();
-    (layout.size() + layout.padding_needed_for(align)) as isize
+    layout.size() + layout.padding_needed_for(align)
 }

library/alloc/src/sync.rs

@@ -908,8 +908,7 @@ impl<T: ?Sized> Arc<T> {
             let offset = data_offset(ptr);
 
             // Reverse the offset to find the original ArcInner.
-            let arc_ptr =
-                (ptr as *mut u8).offset(-offset).with_metadata_of(ptr as *mut ArcInner<T>);
+            let arc_ptr = ptr.byte_sub(offset) as *mut ArcInner<T>;
 
             Self::from_ptr(arc_ptr)
         }
@@ -1942,7 +1941,7 @@ impl<T: ?Sized> Weak<T> {
             let offset = unsafe { data_offset(ptr) };
             // Thus, we reverse the offset to get the whole RcBox.
             // SAFETY: the pointer originated from a Weak, so this offset is safe.
-            unsafe { (ptr as *mut u8).offset(-offset).with_metadata_of(ptr as *mut ArcInner<T>) }
+            unsafe { ptr.byte_sub(offset) as *mut ArcInner<T> }
         };
 
         // SAFETY: we now have recovered the original Weak pointer, so can create the Weak.
@@ -2749,7 +2748,7 @@ impl<T: ?Sized> Unpin for Arc<T> {}
 ///
 /// The pointer must point to (and have valid metadata for) a previously
 /// valid instance of T, but the T is allowed to be dropped.
-unsafe fn data_offset<T: ?Sized>(ptr: *const T) -> isize {
+unsafe fn data_offset<T: ?Sized>(ptr: *const T) -> usize {
     // Align the unsized value to the end of the ArcInner.
     // Because RcBox is repr(C), it will always be the last field in memory.
     // SAFETY: since the only unsized types possible are slices, trait objects,
@@ -2760,7 +2759,7 @@ unsafe fn data_offset<T: ?Sized>(ptr: *const T) -> isize {
 }
 
 #[inline]
-fn data_offset_align(align: usize) -> isize {
+fn data_offset_align(align: usize) -> usize {
     let layout = Layout::new::<ArcInner<()>>();
-    (layout.size() + layout.padding_needed_for(align)) as isize
+    layout.size() + layout.padding_needed_for(align)
 }

src/librustdoc/html/markdown.rs

@@ -1442,7 +1442,6 @@ static DEFAULT_ID_MAP: Lazy<FxHashMap<Cow<'static, str>, usize>> = Lazy::new(||
 fn init_id_map() -> FxHashMap<Cow<'static, str>, usize> {
     let mut map = FxHashMap::default();
     // This is the list of IDs used in Javascript.
-    map.insert("help".into(), 1);
     map.insert("settings".into(), 1);
     map.insert("not-displayed".into(), 1);
     map.insert("alternative-display".into(), 1);
@@ -1455,7 +1454,6 @@ fn init_id_map() -> FxHashMap<Cow<'static, str>, usize> {
     map.insert("help-button".into(), 1);
     map.insert("main-content".into(), 1);
     map.insert("crate-search".into(), 1);
-    map.insert("render-detail".into(), 1);
     map.insert("toggle-all-docs".into(), 1);
     map.insert("all-types".into(), 1);
     map.insert("default-settings".into(), 1);

src/librustdoc/html/static/css/rustdoc.css

@@ -1733,13 +1733,12 @@ details.rustdoc-toggle[open] > summary.hideme > span {
 	display: none;
 }
 
-details.undocumented[open] > summary::before,
 details.rustdoc-toggle[open] > summary::before,
 details.rustdoc-toggle[open] > summary.hideme::before {
 	background-image: /* AUTOREPLACE: */url("toggle-minus.svg");
 }
 
-details.undocumented > summary::before, details.rustdoc-toggle > summary::before {
+details.rustdoc-toggle > summary::before {
 	background-image: /* AUTOREPLACE: */url("toggle-plus.svg");
 }
 

src/librustdoc/html/static/css/themes/ayu.css

@@ -174,13 +174,11 @@ body.source .example-wrap pre.rust a {
 }
 
 details.rustdoc-toggle > summary.hideme > span,
-details.rustdoc-toggle > summary::before,
-details.undocumented > summary::before {
+details.rustdoc-toggle > summary::before {
 	color: #999;
 }
 
-details.rustdoc-toggle > summary::before,
-details.undocumented > summary::before {
+details.rustdoc-toggle > summary::before {
 	filter: invert(100%);
 }
 
@@ -218,17 +216,6 @@ details.undocumented > summary::before {
 	background: none;
 }
 
-#help > div {
-	background: #14191f;
-	box-shadow: 0px 6px 20px 0px black;
-	border: none;
-	border-radius: 4px;
-}
-
-#help span.bottom, #help span.top {
-	border-color: #5c6773;
-}
-
 .rightside,
 .out-of-band {
 	color: grey;

src/librustdoc/html/static/css/themes/dark.css

@@ -148,13 +148,11 @@ body.source .example-wrap pre.rust a {
 }
 
 details.rustdoc-toggle > summary.hideme > span,
-details.rustdoc-toggle > summary::before,
-details.undocumented > summary::before {
+details.rustdoc-toggle > summary::before {
 	color: #999;
 }
 
-details.rustdoc-toggle > summary::before,
-details.undocumented > summary::before {
+details.rustdoc-toggle > summary::before {
 	filter: invert(100%);
 }
 
@@ -179,20 +177,6 @@ details.undocumented > summary::before {
 .stab.portability { background: #F3DFFF; border-color: #b07bdb; color: #2f2f2f; }
 .stab.portability > code { background: none; }
 
-#help > div {
-	background: #4d4d4d;
-	border-color: #bfbfbf;
-}
-
-#help span.bottom, #help span.top {
-	border-color: #bfbfbf;
-}
-
-#help dt {
-	border-color: #bfbfbf;
-	background: rgba(0,0,0,0);
-}
-
 .rightside,
 .out-of-band {
 	color: grey;

src/librustdoc/html/static/css/themes/light.css

@@ -140,8 +140,7 @@ body.source .example-wrap pre.rust a {
 }
 
 details.rustdoc-toggle > summary.hideme > span,
-details.rustdoc-toggle > summary::before,
-details.undocumented > summary::before {
+details.rustdoc-toggle > summary::before {
 	color: #999;
 }
 
@@ -161,15 +160,6 @@ details.undocumented > summary::before {
 .stab.portability { background: #F3DFFF; border-color: #b07bdb; }
 .stab.portability > code { background: none; }
 
-#help > div {
-	background: #e9e9e9;
-	border-color: #bfbfbf;
-}
-
-#help span.bottom, #help span.top {
-	border-color: #bfbfbf;
-}
-
 .rightside,
 .out-of-band {
 	color: grey;

src/test/ui/argument-suggestions/exotic-calls.rs

@@ -0,0 +1,26 @@
+fn foo<T: Fn()>(t: T) {
+    t(1i32);
+    //~^ ERROR this function takes 0 arguments but 1 argument was supplied
+}
+
+fn bar(t: impl Fn()) {
+    t(1i32);
+    //~^ ERROR this function takes 0 arguments but 1 argument was supplied
+}
+
+fn baz() -> impl Fn() {
+    || {}
+}
+
+fn baz2() {
+    baz()(1i32)
+    //~^ ERROR this function takes 0 arguments but 1 argument was supplied
+}
+
+fn qux() {
+    let x = || {};
+    x(1i32);
+    //~^ ERROR this function takes 0 arguments but 1 argument was supplied
+}
+
+fn main() {}

src/test/ui/argument-suggestions/exotic-calls.stderr

@@ -0,0 +1,67 @@
+error[E0057]: this function takes 0 arguments but 1 argument was supplied
+  --> $DIR/exotic-calls.rs:2:5
+   |
+LL |     t(1i32);
+   |     ^ ---- argument of type `i32` unexpected
+   |
+note: callable defined here
+  --> $DIR/exotic-calls.rs:1:11
+   |
+LL | fn foo<T: Fn()>(t: T) {
+   |           ^^^^
+help: remove the extra argument
+   |
+LL |     t();
+   |     ~~~
+
+error[E0057]: this function takes 0 arguments but 1 argument was supplied
+  --> $DIR/exotic-calls.rs:7:5
+   |
+LL |     t(1i32);
+   |     ^ ---- argument of type `i32` unexpected
+   |
+note: type parameter defined here
+  --> $DIR/exotic-calls.rs:6:11
+   |
+LL | fn bar(t: impl Fn()) {
+   |           ^^^^^^^^^
+help: remove the extra argument
+   |
+LL |     t();
+   |     ~~~
+
+error[E0057]: this function takes 0 arguments but 1 argument was supplied
+  --> $DIR/exotic-calls.rs:16:5
+   |
+LL |     baz()(1i32)
+   |     ^^^^^ ---- argument of type `i32` unexpected
+   |
+note: opaque type defined here
+  --> $DIR/exotic-calls.rs:11:13
+   |
+LL | fn baz() -> impl Fn() {
+   |             ^^^^^^^^^
+help: remove the extra argument
+   |
+LL |     baz()()
+   |
+
+error[E0057]: this function takes 0 arguments but 1 argument was supplied
+  --> $DIR/exotic-calls.rs:22:5
+   |
+LL |     x(1i32);
+   |     ^ ---- argument of type `i32` unexpected
+   |
+note: closure defined here
+  --> $DIR/exotic-calls.rs:21:13
+   |
+LL |     let x = || {};
+   |             ^^
+help: remove the extra argument
+   |
+LL |     x();
+   |     ~~~
+
+error: aborting due to 4 previous errors
+
+For more information about this error, try `rustc --explain E0057`.

src/test/ui/higher-rank-trait-bounds/normalize-under-binder/issue-89436.rs

@@ -0,0 +1,44 @@
+// check-pass
+
+#![allow(unused)]
+
+trait MiniYokeable<'a> {
+    type Output;
+}
+
+struct MiniYoke<Y: for<'a> MiniYokeable<'a>> {
+    pub yokeable: Y,
+}
+
+fn map_project_broken<Y, P>(
+    source: MiniYoke<Y>,
+    f: impl for<'a> FnOnce(
+        <Y as MiniYokeable<'a>>::Output,
+        core::marker::PhantomData<&'a ()>,
+    ) -> <P as MiniYokeable<'a>>::Output,
+) -> MiniYoke<P>
+where
+    Y: for<'a> MiniYokeable<'a>,
+    P: for<'a> MiniYokeable<'a>
+{
+    unimplemented!()
+}
+
+struct Bar<'a> {
+    string_1: &'a str,
+    string_2: &'a str,
+}
+
+impl<'a> MiniYokeable<'a> for Bar<'static> {
+    type Output = Bar<'a>;
+}
+
+impl<'a> MiniYokeable<'a> for &'static str {
+    type Output = &'a str;
+}
+
+fn demo_broken(bar: MiniYoke<Bar<'static>>) -> MiniYoke<&'static str> {
+    map_project_broken(bar, |bar, _| bar.string_1)
+}
+
+fn main() {}

src/test/ui/issues/issue-16939.stderr

@@ -4,11 +4,11 @@ error[E0057]: this function takes 0 arguments but 1 argument was supplied
 LL |     |t| f(t);
    |         ^ - argument unexpected
    |
-note: associated function defined here
-  --> $SRC_DIR/core/src/ops/function.rs:LL:COL
+note: callable defined here
+  --> $DIR/issue-16939.rs:4:12
    |
-LL |     extern "rust-call" fn call(&self, args: Args) -> Self::Output;
-   |                           ^^^^
+LL | fn _foo<F: Fn()> (f: F) {
+   |            ^^^^
 help: remove the extra argument
    |
 LL |     |t| f();

src/test/ui/mismatched_types/overloaded-calls-bad.stderr

@@ -6,11 +6,11 @@ LL |     let ans = s("what");
    |               |
    |               arguments to this function are incorrect
    |
-note: associated function defined here
-  --> $SRC_DIR/core/src/ops/function.rs:LL:COL
+note: implementation defined here
+  --> $DIR/overloaded-calls-bad.rs:10:1
    |
-LL |     extern "rust-call" fn call_mut(&mut self, args: Args) -> Self::Output;
-   |                           ^^^^^^^^
+LL | impl FnMut<(isize,)> for S {
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error[E0057]: this function takes 1 argument but 0 arguments were supplied
   --> $DIR/overloaded-calls-bad.rs:29:15
@@ -18,11 +18,11 @@ error[E0057]: this function takes 1 argument but 0 arguments were supplied
 LL |     let ans = s();
    |               ^-- an argument of type `isize` is missing
    |
-note: associated function defined here
-  --> $SRC_DIR/core/src/ops/function.rs:LL:COL
+note: implementation defined here
+  --> $DIR/overloaded-calls-bad.rs:10:1
    |
-LL |     extern "rust-call" fn call_mut(&mut self, args: Args) -> Self::Output;
-   |                           ^^^^^^^^
+LL | impl FnMut<(isize,)> for S {
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^
 help: provide the argument
    |
 LL |     let ans = s(/* isize */);
@@ -36,11 +36,11 @@ LL |     let ans = s("burma", "shave");
    |                 |
    |                 expected `isize`, found `&str`
    |
-note: associated function defined here
-  --> $SRC_DIR/core/src/ops/function.rs:LL:COL
+note: implementation defined here
+  --> $DIR/overloaded-calls-bad.rs:10:1
    |
-LL |     extern "rust-call" fn call_mut(&mut self, args: Args) -> Self::Output;
-   |                           ^^^^^^^^
+LL | impl FnMut<(isize,)> for S {
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^
 help: remove the extra argument
    |
 LL |     let ans = s(/* isize */);

triagebot.toml

@@ -340,4 +340,4 @@ cc = ["@rust-lang/rustfmt"]
 
 [mentions."compiler/rustc_middle/src/mir/syntax.rs"]
 message = "This PR changes MIR"
-cc = ["@oli-obk", "@RalfJung", "@JakobDegen", "@davidtwco", "@celinval"]
+cc = ["@oli-obk", "@RalfJung", "@JakobDegen", "@davidtwco", "@celinval", "@vakaras"]