fix(rustc_typeck): report function argument errors on matching type

Fixes #90101

33 files changed, 250 insertions, 139 deletions

diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs
index 8396e3263f9..5d17693dc08 100644
--- a/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs
+++ b/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs
@@ -1492,6 +1492,9 @@ impl<'a, 'tcx> InferCtxtPrivExt<'tcx> for InferCtxt<'a, 'tcx> {
                     }
                 }
             }
+            ObligationCauseCode::FunctionArgumentObligation { parent_code, .. } => {
+                self.get_parent_trait_ref(&parent_code)
+            }
             _ => None,
         }
     }
diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs
index d602662ba6b..2689e2134fc 100644
--- a/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs
+++ b/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs
@@ -1422,6 +1422,9 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> {
         while let Some(code) = next_code {
             debug!("maybe_note_obligation_cause_for_async_await: code={:?}", code);
             match code {
+                ObligationCauseCode::FunctionArgumentObligation { parent_code, .. } => {
+                    next_code = Some(parent_code.as_ref());
+                }
                 ObligationCauseCode::DerivedObligation(derived_obligation)
                 | ObligationCauseCode::BuiltinDerivedObligation(derived_obligation)
                 | ObligationCauseCode::ImplDerivedObligation(derived_obligation) => {
diff --git a/compiler/rustc_typeck/src/check/fn_ctxt/checks.rs b/compiler/rustc_typeck/src/check/fn_ctxt/checks.rs
index 551522334aa..b3e18dab363 100644
--- a/compiler/rustc_typeck/src/check/fn_ctxt/checks.rs
+++ b/compiler/rustc_typeck/src/check/fn_ctxt/checks.rs
@@ -370,6 +370,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 //    `ExpectHasType(expected_ty)`, or the `formal_ty` otherwise.
                 let coerce_ty = expected.only_has_type(self).unwrap_or(formal_ty);
 
+                final_arg_types.push((i, checked_ty, coerce_ty));
+
                 // Cause selection errors caused by resolving a single argument to point at the
                 // argument and not the call. This is otherwise redundant with the `demand_coerce`
                 // call immediately after, but it lets us customize the span pointed to in the
@@ -377,38 +379,20 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 let _ = self.resolve_vars_with_obligations_and_mutate_fulfillment(
                     coerce_ty,
                     |errors| {
-                        // This is not coming from a macro or a `derive`.
-                        if sp.desugaring_kind().is_none()
-                        && !arg.span.from_expansion()
-                        // Do not change the spans of `async fn`s.
-                        && !matches!(
-                            expr.kind,
-                            hir::ExprKind::Call(
-                                hir::Expr {
-                                    kind: hir::ExprKind::Path(hir::QPath::LangItem(_, _)),
-                                    ..
-                                },
-                                _
-                            )
-                        ) {
-                            for error in errors {
-                                error.obligation.cause.make_mut().span = arg.span;
-                                let code = error.obligation.cause.code.clone();
-                                error.obligation.cause.make_mut().code =
-                                    ObligationCauseCode::FunctionArgumentObligation {
-                                        arg_hir_id: arg.hir_id,
-                                        call_hir_id: expr.hir_id,
-                                        parent_code: Lrc::new(code),
-                                    };
-                            }
-                        }
+                        self.point_at_type_arg_instead_of_call_if_possible(errors, expr);
+                        self.point_at_arg_instead_of_call_if_possible(
+                            errors,
+                            &final_arg_types,
+                            expr,
+                            sp,
+                            args,
+                        );
                     },
                 );
 
                 // We're processing function arguments so we definitely want to use
                 // two-phase borrows.
                 self.demand_coerce(&arg, checked_ty, coerce_ty, None, AllowTwoPhase::Yes);
-                final_arg_types.push((i, checked_ty, coerce_ty));
 
                 // 3. Relate the expected type and the formal one,
                 //    if the expected type was used for the coercion.
@@ -973,45 +957,79 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 continue;
             }
 
-            if let ty::PredicateKind::Trait(predicate) =
-                error.obligation.predicate.kind().skip_binder()
-            {
-                // Collect the argument position for all arguments that could have caused this
-                // `FulfillmentError`.
-                let mut referenced_in = final_arg_types
-                    .iter()
-                    .map(|&(i, checked_ty, _)| (i, checked_ty))
-                    .chain(final_arg_types.iter().map(|&(i, _, coerced_ty)| (i, coerced_ty)))
-                    .flat_map(|(i, ty)| {
-                        let ty = self.resolve_vars_if_possible(ty);
-                        // We walk the argument type because the argument's type could have
-                        // been `Option<T>`, but the `FulfillmentError` references `T`.
-                        if ty.walk(self.tcx).any(|arg| arg == predicate.self_ty().into()) {
-                            Some(i)
-                        } else {
-                            None
-                        }
-                    })
-                    .collect::<Vec<usize>>();
-
-                // Both checked and coerced types could have matched, thus we need to remove
-                // duplicates.
-
-                // We sort primitive type usize here and can use unstable sort
-                referenced_in.sort_unstable();
-                referenced_in.dedup();
-
-                if let (Some(ref_in), None) = (referenced_in.pop(), referenced_in.pop()) {
-                    // We make sure that only *one* argument matches the obligation failure
-                    // and we assign the obligation's span to its expression's.
-                    error.obligation.cause.make_mut().span = args[ref_in].span;
-                    let code = error.obligation.cause.code.clone();
-                    error.obligation.cause.make_mut().code =
-                        ObligationCauseCode::FunctionArgumentObligation {
-                            arg_hir_id: args[ref_in].hir_id,
-                            call_hir_id: expr.hir_id,
-                            parent_code: Lrc::new(code),
-                        };
+            // Peel derived obligation, because it's the type that originally
+            // started this inference chain that matters, not the one we wound
+            // up with at the end.
+            fn unpeel_to_top(
+                mut code: Lrc<ObligationCauseCode<'_>>,
+            ) -> Lrc<ObligationCauseCode<'_>> {
+                let mut result_code = code.clone();
+                loop {
+                    let parent = match &*code {
+                        ObligationCauseCode::BuiltinDerivedObligation(c)
+                        | ObligationCauseCode::ImplDerivedObligation(c)
+                        | ObligationCauseCode::DerivedObligation(c) => c.parent_code.clone(),
+                        _ => break,
+                    };
+                    result_code = std::mem::replace(&mut code, parent);
+                }
+                result_code
+            }
+            let self_: ty::subst::GenericArg<'_> = match &*unpeel_to_top(Lrc::new(error.obligation.cause.code.clone())) {
+                ObligationCauseCode::BuiltinDerivedObligation(code) |
+                ObligationCauseCode::ImplDerivedObligation(code) |
+                ObligationCauseCode::DerivedObligation(code) => {
+                    code.parent_trait_ref.self_ty().skip_binder().into()
+                }
+                _ if let ty::PredicateKind::Trait(predicate) =
+                    error.obligation.predicate.kind().skip_binder() => {
+                        predicate.self_ty().into()
+                    }
+                _ =>  continue,
+            };
+            let self_ = self.resolve_vars_if_possible(self_);
+
+            // Collect the argument position for all arguments that could have caused this
+            // `FulfillmentError`.
+            let mut referenced_in = final_arg_types
+                .iter()
+                .map(|&(i, checked_ty, _)| (i, checked_ty))
+                .chain(final_arg_types.iter().map(|&(i, _, coerced_ty)| (i, coerced_ty)))
+                .flat_map(|(i, ty)| {
+                    let ty = self.resolve_vars_if_possible(ty);
+                    // We walk the argument type because the argument's type could have
+                    // been `Option<T>`, but the `FulfillmentError` references `T`.
+                    if ty.walk(self.tcx).any(|arg| arg == self_) { Some(i) } else { None }
+                })
+                .collect::<Vec<usize>>();
+
+            // Both checked and coerced types could have matched, thus we need to remove
+            // duplicates.
+
+            // We sort primitive type usize here and can use unstable sort
+            referenced_in.sort_unstable();
+            referenced_in.dedup();
+
+            if let (Some(ref_in), None) = (referenced_in.pop(), referenced_in.pop()) {
+                // Do not point at the inside of a macro.
+                // That would often result in poor error messages.
+                if args[ref_in].span.from_expansion() {
+                    return;
+                }
+                // We make sure that only *one* argument matches the obligation failure
+                // and we assign the obligation's span to its expression's.
+                error.obligation.cause.make_mut().span = args[ref_in].span;
+                let code = error.obligation.cause.code.clone();
+                error.obligation.cause.make_mut().code =
+                    ObligationCauseCode::FunctionArgumentObligation {
+                        arg_hir_id: args[ref_in].hir_id,
+                        call_hir_id: expr.hir_id,
+                        parent_code: Lrc::new(code),
+                    };
+            } else if error.obligation.cause.make_mut().span == call_sp {
+                // Make function calls point at the callee, not the whole thing.
+                if let hir::ExprKind::Call(callee, _) = expr.kind {
+                    error.obligation.cause.make_mut().span = callee.span;
                 }
             }
         }
diff --git a/src/test/ui/associated-types/associated-types-path-2.rs b/src/test/ui/associated-types/associated-types-path-2.rs
index 912dedfdceb..c993e1d2720 100644
--- a/src/test/ui/associated-types/associated-types-path-2.rs
+++ b/src/test/ui/associated-types/associated-types-path-2.rs
@@ -28,11 +28,13 @@ pub fn f1_int_uint() {
 pub fn f1_uint_uint() {
     f1(2u32, 4u32);
     //~^ ERROR `u32: Foo` is not satisfied
+    //~| ERROR `u32: Foo` is not satisfied
 }
 
 pub fn f1_uint_int() {
     f1(2u32, 4i32);
     //~^ ERROR `u32: Foo` is not satisfied
+    //~| ERROR `u32: Foo` is not satisfied
 }
 
 pub fn f2_int() {
diff --git a/src/test/ui/associated-types/associated-types-path-2.stderr b/src/test/ui/associated-types/associated-types-path-2.stderr
index 15a5245d54d..b3bb58f7814 100644
--- a/src/test/ui/associated-types/associated-types-path-2.stderr
+++ b/src/test/ui/associated-types/associated-types-path-2.stderr
@@ -10,12 +10,10 @@ LL |     f1(2i32, 4u32);
    |               ~~~
 
 error[E0277]: the trait bound `u32: Foo` is not satisfied
-  --> $DIR/associated-types-path-2.rs:29:14
+  --> $DIR/associated-types-path-2.rs:29:5
    |
 LL |     f1(2u32, 4u32);
-   |     --       ^^^^ the trait `Foo` is not implemented for `u32`
-   |     |
-   |     required by a bound introduced by this call
+   |     ^^ the trait `Foo` is not implemented for `u32`
    |
 note: required by a bound in `f1`
   --> $DIR/associated-types-path-2.rs:13:14
@@ -24,10 +22,16 @@ LL | pub fn f1<T: Foo>(a: T, x: T::A) {}
    |              ^^^ required by this bound in `f1`
 
 error[E0277]: the trait bound `u32: Foo` is not satisfied
-  --> $DIR/associated-types-path-2.rs:34:14
+  --> $DIR/associated-types-path-2.rs:29:14
+   |
+LL |     f1(2u32, 4u32);
+   |              ^^^^ the trait `Foo` is not implemented for `u32`
+
+error[E0277]: the trait bound `u32: Foo` is not satisfied
+  --> $DIR/associated-types-path-2.rs:35:8
    |
 LL |     f1(2u32, 4i32);
-   |     --       ^^^^ the trait `Foo` is not implemented for `u32`
+   |     -- ^^^^ the trait `Foo` is not implemented for `u32`
    |     |
    |     required by a bound introduced by this call
    |
@@ -37,8 +41,14 @@ note: required by a bound in `f1`
 LL | pub fn f1<T: Foo>(a: T, x: T::A) {}
    |              ^^^ required by this bound in `f1`
 
+error[E0277]: the trait bound `u32: Foo` is not satisfied
+  --> $DIR/associated-types-path-2.rs:35:14
+   |
+LL |     f1(2u32, 4i32);
+   |              ^^^^ the trait `Foo` is not implemented for `u32`
+
 error[E0308]: mismatched types
-  --> $DIR/associated-types-path-2.rs:39:18
+  --> $DIR/associated-types-path-2.rs:41:18
    |
 LL |     let _: i32 = f2(2i32);
    |            ---   ^^^^^^^^ expected `i32`, found `u32`
@@ -50,7 +60,7 @@ help: you can convert a `u32` to an `i32` and panic if the converted value doesn
 LL |     let _: i32 = f2(2i32).try_into().unwrap();
    |                          ++++++++++++++++++++
 
-error: aborting due to 4 previous errors
+error: aborting due to 6 previous errors
 
 Some errors have detailed explanations: E0277, E0308.
 For more information about an error, try `rustc --explain E0277`.
diff --git a/src/test/ui/async-await/async-fn-nonsend.stderr b/src/test/ui/async-await/async-fn-nonsend.stderr
index d509ff3598b..baaab7fee67 100644
--- a/src/test/ui/async-await/async-fn-nonsend.stderr
+++ b/src/test/ui/async-await/async-fn-nonsend.stderr
@@ -1,8 +1,8 @@
 error: future cannot be sent between threads safely
-  --> $DIR/async-fn-nonsend.rs:49:5
+  --> $DIR/async-fn-nonsend.rs:49:17
    |
 LL |     assert_send(local_dropped_before_await());
-   |     ^^^^^^^^^^^ future returned by `local_dropped_before_await` is not `Send`
+   |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ future returned by `local_dropped_before_await` is not `Send`
    |
    = help: within `impl Future`, the trait `Send` is not implemented for `Rc<()>`
 note: future is not `Send` as this value is used across an await
@@ -22,10 +22,10 @@ LL | fn assert_send(_: impl Send) {}
    |                        ^^^^ required by this bound in `assert_send`
 
 error: future cannot be sent between threads safely
-  --> $DIR/async-fn-nonsend.rs:51:5
+  --> $DIR/async-fn-nonsend.rs:51:17
    |
 LL |     assert_send(non_send_temporary_in_match());
-   |     ^^^^^^^^^^^ future returned by `non_send_temporary_in_match` is not `Send`
+   |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ future returned by `non_send_temporary_in_match` is not `Send`
    |
    = help: within `impl Future`, the trait `Send` is not implemented for `Rc<()>`
 note: future is not `Send` as this value is used across an await
@@ -45,10 +45,10 @@ LL | fn assert_send(_: impl Send) {}
    |                        ^^^^ required by this bound in `assert_send`
 
 error: future cannot be sent between threads safely
-  --> $DIR/async-fn-nonsend.rs:53:5
+  --> $DIR/async-fn-nonsend.rs:53:17
    |
 LL |     assert_send(non_sync_with_method_call());
-   |     ^^^^^^^^^^^ future returned by `non_sync_with_method_call` is not `Send`
+   |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ future returned by `non_sync_with_method_call` is not `Send`
    |
    = help: the trait `Send` is not implemented for `dyn std::fmt::Write`
 note: future is not `Send` as this value is used across an await
diff --git a/src/test/ui/async-await/issue-64130-1-sync.stderr b/src/test/ui/async-await/issue-64130-1-sync.stderr
index 69c7ff47456..12e4bfc3d48 100644
--- a/src/test/ui/async-await/issue-64130-1-sync.stderr
+++ b/src/test/ui/async-await/issue-64130-1-sync.stderr
@@ -1,8 +1,8 @@
 error: future cannot be shared between threads safely
-  --> $DIR/issue-64130-1-sync.rs:21:5
+  --> $DIR/issue-64130-1-sync.rs:21:13
    |
 LL |     is_sync(bar());
-   |     ^^^^^^^ future returned by `bar` is not `Sync`
+   |             ^^^^^ future returned by `bar` is not `Sync`
    |
    = help: within `impl Future`, the trait `Sync` is not implemented for `Foo`
 note: future is not `Sync` as this value is used across an await
diff --git a/src/test/ui/async-await/issue-64130-2-send.stderr b/src/test/ui/async-await/issue-64130-2-send.stderr
index 933e9296848..9c94b8da892 100644
--- a/src/test/ui/async-await/issue-64130-2-send.stderr
+++ b/src/test/ui/async-await/issue-64130-2-send.stderr
@@ -1,8 +1,8 @@
 error: future cannot be sent between threads safely
-  --> $DIR/issue-64130-2-send.rs:21:5
+  --> $DIR/issue-64130-2-send.rs:21:13
    |
 LL |     is_send(bar());
-   |     ^^^^^^^ future returned by `bar` is not `Send`
+   |             ^^^^^ future returned by `bar` is not `Send`
    |
    = help: within `impl Future`, the trait `Send` is not implemented for `Foo`
 note: future is not `Send` as this value is used across an await
diff --git a/src/test/ui/async-await/issue-64130-3-other.stderr b/src/test/ui/async-await/issue-64130-3-other.stderr
index ec0fdd4a555..3dd1239e23d 100644
--- a/src/test/ui/async-await/issue-64130-3-other.stderr
+++ b/src/test/ui/async-await/issue-64130-3-other.stderr
@@ -1,11 +1,11 @@
 error[E0277]: the trait bound `Foo: Qux` is not satisfied in `impl Future`
-  --> $DIR/issue-64130-3-other.rs:24:5
+  --> $DIR/issue-64130-3-other.rs:24:12
    |
 LL | async fn bar() {
    |                - within this `impl Future`
 ...
 LL |     is_qux(bar());
-   |     ^^^^^^ within `impl Future`, the trait `Qux` is not implemented for `Foo`
+   |            ^^^^^ within `impl Future`, the trait `Qux` is not implemented for `Foo`
    |
 note: future does not implement `Qux` as this value is used across an await
   --> $DIR/issue-64130-3-other.rs:18:5
diff --git a/src/test/ui/async-await/issue-64130-non-send-future-diags.stderr b/src/test/ui/async-await/issue-64130-non-send-future-diags.stderr
index 472fffa61b7..7125c62dbaf 100644
--- a/src/test/ui/async-await/issue-64130-non-send-future-diags.stderr
+++ b/src/test/ui/async-await/issue-64130-non-send-future-diags.stderr
@@ -1,8 +1,8 @@
 error: future cannot be sent between threads safely
-  --> $DIR/issue-64130-non-send-future-diags.rs:21:5
+  --> $DIR/issue-64130-non-send-future-diags.rs:21:13
    |
 LL |     is_send(foo());
-   |     ^^^^^^^ future returned by `foo` is not `Send`
+   |             ^^^^^ future returned by `foo` is not `Send`
    |
    = help: within `impl Future`, the trait `Send` is not implemented for `MutexGuard<'_, u32>`
 note: future is not `Send` as this value is used across an await
diff --git a/src/test/ui/async-await/issue-71137.stderr b/src/test/ui/async-await/issue-71137.stderr
index 8903c09c17f..ac254346c08 100644
--- a/src/test/ui/async-await/issue-71137.stderr
+++ b/src/test/ui/async-await/issue-71137.stderr
@@ -1,8 +1,8 @@
 error: future cannot be sent between threads safely
-  --> $DIR/issue-71137.rs:20:3
+  --> $DIR/issue-71137.rs:20:14
    |
 LL |   fake_spawn(wrong_mutex());
-   |   ^^^^^^^^^^ future returned by `wrong_mutex` is not `Send`
+   |              ^^^^^^^^^^^^^ future returned by `wrong_mutex` is not `Send`
    |
    = help: within `impl Future`, the trait `Send` is not implemented for `MutexGuard<'_, i32>`
 note: future is not `Send` as this value is used across an await
diff --git a/src/test/ui/async-await/issues/issue-67893.stderr b/src/test/ui/async-await/issues/issue-67893.stderr
index 7321a38c021..ee32a1a9e4f 100644
--- a/src/test/ui/async-await/issues/issue-67893.stderr
+++ b/src/test/ui/async-await/issues/issue-67893.stderr
@@ -1,8 +1,8 @@
 error: generator cannot be sent between threads safely
-  --> $DIR/issue-67893.rs:9:5
+  --> $DIR/issue-67893.rs:9:7
    |
 LL |     g(issue_67893::run())
-   |     ^ generator is not `Send`
+   |       ^^^^^^^^^^^^^^^^^^ generator is not `Send`
    |
    = help: within `impl Future`, the trait `Send` is not implemented for `MutexGuard<'_, ()>`
 note: required by a bound in `g`
diff --git a/src/test/ui/async-await/pin-needed-to-poll-2.stderr b/src/test/ui/async-await/pin-needed-to-poll-2.stderr
index 8c581ff2229..b63ea106d90 100644
--- a/src/test/ui/async-await/pin-needed-to-poll-2.stderr
+++ b/src/test/ui/async-await/pin-needed-to-poll-2.stderr
@@ -1,8 +1,10 @@
 error[E0277]: `PhantomPinned` cannot be unpinned
-  --> $DIR/pin-needed-to-poll-2.rs:43:9
+  --> $DIR/pin-needed-to-poll-2.rs:43:18
    |
 LL |         Pin::new(&mut self.sleep).poll(cx)
-   |         ^^^^^^^^ within `Sleep`, the trait `Unpin` is not implemented for `PhantomPinned`
+   |         -------- ^^^^^^^^^^^^^^^ within `Sleep`, the trait `Unpin` is not implemented for `PhantomPinned`
+   |         |
+   |         required by a bound introduced by this call
    |
    = note: consider using `Box::pin`
 note: required because it appears within the type `Sleep`
diff --git a/src/test/ui/const-generics/generic_const_exprs/issue-85848.stderr b/src/test/ui/const-generics/generic_const_exprs/issue-85848.stderr
index e51db35925e..4202cbae7eb 100644
--- a/src/test/ui/const-generics/generic_const_exprs/issue-85848.stderr
+++ b/src/test/ui/const-generics/generic_const_exprs/issue-85848.stderr
@@ -1,8 +1,10 @@
 error[E0277]: the trait bound `(): _Contains<&C>` is not satisfied
-  --> $DIR/issue-85848.rs:24:5
+  --> $DIR/issue-85848.rs:24:29
    |
 LL |     writes_to_specific_path(&cap);
-   |     ^^^^^^^^^^^^^^^^^^^^^^^ the trait `_Contains<&C>` is not implemented for `()`
+   |     ----------------------- ^^^^ the trait `_Contains<&C>` is not implemented for `()`
+   |     |
+   |     required by a bound introduced by this call
    |
 note: required because of the requirements on the impl of `Contains<(), true>` for `&C`
   --> $DIR/issue-85848.rs:21:12
@@ -21,10 +23,12 @@ LL | fn writes_to_specific_path<C: Delegates<()>>(cap: &C) {}
    |                               ^^^^^^^^^^^^^ required by this bound in `writes_to_specific_path`
 
 error: unconstrained generic constant
-  --> $DIR/issue-85848.rs:24:5
+  --> $DIR/issue-85848.rs:24:29
    |
 LL |     writes_to_specific_path(&cap);
-   |     ^^^^^^^^^^^^^^^^^^^^^^^
+   |     ----------------------- ^^^^
+   |     |
+   |     required by a bound introduced by this call
    |
    = help: try adding a `where` bound using this expression: `where [(); { contains::<T, U>() }]:`
 note: required because of the requirements on the impl of `Contains<(), true>` for `&C`
diff --git a/src/test/ui/hrtb/issue-62203-hrtb-ice.rs b/src/test/ui/hrtb/issue-62203-hrtb-ice.rs
index 454d7e5e9cd..80f099ce3c8 100644
--- a/src/test/ui/hrtb/issue-62203-hrtb-ice.rs
+++ b/src/test/ui/hrtb/issue-62203-hrtb-ice.rs
@@ -37,8 +37,8 @@ trait Ty<'a> {
 fn main() {
     let v = Unit2.m(
         //~^ ERROR type mismatch
-        //~| ERROR type mismatch
         L {
+        //~^ ERROR type mismatch
             f : |x| { drop(x); Unit4 }
         });
 }
diff --git a/src/test/ui/hrtb/issue-62203-hrtb-ice.stderr b/src/test/ui/hrtb/issue-62203-hrtb-ice.stderr
index 97f53bc70e4..4c5c59c2209 100644
--- a/src/test/ui/hrtb/issue-62203-hrtb-ice.stderr
+++ b/src/test/ui/hrtb/issue-62203-hrtb-ice.stderr
@@ -10,10 +10,16 @@ LL |     let v = Unit2.m(
    = note: for more information, visit https://doc.rust-lang.org/book/ch19-03-advanced-traits.html
 
 error[E0271]: type mismatch resolving `for<'r> <[closure@$DIR/issue-62203-hrtb-ice.rs:42:17: 42:39] as FnOnce<((&'r u8,),)>>::Output == Unit3`
-  --> $DIR/issue-62203-hrtb-ice.rs:38:19
+  --> $DIR/issue-62203-hrtb-ice.rs:40:9
    |
-LL |     let v = Unit2.m(
-   |                   ^ expected struct `Unit4`, found struct `Unit3`
+LL |       let v = Unit2.m(
+   |                     - required by a bound introduced by this call
+LL |
+LL | /         L {
+LL | |
+LL | |             f : |x| { drop(x); Unit4 }
+LL | |         });
+   | |_________^ expected struct `Unit4`, found struct `Unit3`
    |
 note: required because of the requirements on the impl of `for<'r> T0<'r, (&'r u8,)>` for `L<[closure@$DIR/issue-62203-hrtb-ice.rs:42:17: 42:39]>`
   --> $DIR/issue-62203-hrtb-ice.rs:17:16
diff --git a/src/test/ui/impl-trait/auto-trait-leak2.stderr b/src/test/ui/impl-trait/auto-trait-leak2.stderr
index 5a8e5036014..8c53b4105bb 100644
--- a/src/test/ui/impl-trait/auto-trait-leak2.stderr
+++ b/src/test/ui/impl-trait/auto-trait-leak2.stderr
@@ -1,11 +1,13 @@
 error[E0277]: `Rc<Cell<i32>>` cannot be sent between threads safely
-  --> $DIR/auto-trait-leak2.rs:13:5
+  --> $DIR/auto-trait-leak2.rs:13:10
    |
 LL | fn before() -> impl Fn(i32) {
    |                ------------ within this `impl Fn<(i32,)>`
 ...
 LL |     send(before());
-   |     ^^^^ `Rc<Cell<i32>>` cannot be sent between threads safely
+   |     ---- ^^^^^^^^ `Rc<Cell<i32>>` cannot be sent between threads safely
+   |     |
+   |     required by a bound introduced by this call
    |
    = help: within `impl Fn<(i32,)>`, the trait `Send` is not implemented for `Rc<Cell<i32>>`
    = note: required because it appears within the type `[closure@$DIR/auto-trait-leak2.rs:7:5: 7:22]`
@@ -17,10 +19,12 @@ LL | fn send<T: Send>(_: T) {}
    |            ^^^^ required by this bound in `send`
 
 error[E0277]: `Rc<Cell<i32>>` cannot be sent between threads safely
-  --> $DIR/auto-trait-leak2.rs:16:5
+  --> $DIR/auto-trait-leak2.rs:16:10
    |
 LL |     send(after());
-   |     ^^^^ `Rc<Cell<i32>>` cannot be sent between threads safely
+   |     ---- ^^^^^^^ `Rc<Cell<i32>>` cannot be sent between threads safely
+   |     |
+   |     required by a bound introduced by this call
 ...
 LL | fn after() -> impl Fn(i32) {
    |               ------------ within this `impl Fn<(i32,)>`
diff --git a/src/test/ui/intrinsics/const-eval-select-bad.rs b/src/test/ui/intrinsics/const-eval-select-bad.rs
index 8fbdc0c39c6..a3171187e69 100644
--- a/src/test/ui/intrinsics/const-eval-select-bad.rs
+++ b/src/test/ui/intrinsics/const-eval-select-bad.rs
@@ -7,6 +7,7 @@ const fn not_fn_items() {
     //~^ ERROR expected a `FnOnce<()>` closure
     const_eval_select((), 42, 0xDEADBEEF);
     //~^ ERROR expected a `FnOnce<()>` closure
+    //~| ERROR expected a `FnOnce<()>` closure
 }
 
 const fn foo(n: i32) -> i32 {
diff --git a/src/test/ui/intrinsics/const-eval-select-bad.stderr b/src/test/ui/intrinsics/const-eval-select-bad.stderr
index 78647e92138..5e1ab584d80 100644
--- a/src/test/ui/intrinsics/const-eval-select-bad.stderr
+++ b/src/test/ui/intrinsics/const-eval-select-bad.stderr
@@ -1,8 +1,8 @@
 error[E0277]: expected a `FnOnce<()>` closure, found `[closure@$DIR/const-eval-select-bad.rs:6:27: 6:32]`
-  --> $DIR/const-eval-select-bad.rs:6:34
+  --> $DIR/const-eval-select-bad.rs:6:27
    |
 LL |     const_eval_select((), || {}, || {});
-   |     -----------------            ^^^^^ expected an `FnOnce<()>` closure, found `[closure@$DIR/const-eval-select-bad.rs:6:27: 6:32]`
+   |     -----------------     ^^^^^ expected an `FnOnce<()>` closure, found `[closure@$DIR/const-eval-select-bad.rs:6:27: 6:32]`
    |     |
    |     required by a bound introduced by this call
    |
@@ -15,10 +15,10 @@ LL |     F: ~const FnOnce<ARG, Output = RET>,
    |        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `const_eval_select`
 
 error[E0277]: expected a `FnOnce<()>` closure, found `{integer}`
-  --> $DIR/const-eval-select-bad.rs:8:31
+  --> $DIR/const-eval-select-bad.rs:8:27
    |
 LL |     const_eval_select((), 42, 0xDEADBEEF);
-   |     -----------------         ^^^^^^^^^^ expected an `FnOnce<()>` closure, found `{integer}`
+   |     -----------------     ^^ expected an `FnOnce<()>` closure, found `{integer}`
    |     |
    |     required by a bound introduced by this call
    |
@@ -30,8 +30,24 @@ note: required by a bound in `const_eval_select`
 LL |     F: ~const FnOnce<ARG, Output = RET>,
    |        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `const_eval_select`
 
+error[E0277]: expected a `FnOnce<()>` closure, found `{integer}`
+  --> $DIR/const-eval-select-bad.rs:8:31
+   |
+LL |     const_eval_select((), 42, 0xDEADBEEF);
+   |     -----------------         ^^^^^^^^^^ expected an `FnOnce<()>` closure, found `{integer}`
+   |     |
+   |     required by a bound introduced by this call
+   |
+   = help: the trait `FnOnce<()>` is not implemented for `{integer}`
+   = note: wrap the `{integer}` in a closure with no arguments: `|| { /* code */ }`
+note: required by a bound in `const_eval_select`
+  --> $SRC_DIR/core/src/intrinsics.rs:LL:COL
+   |
+LL |     G: FnOnce<ARG, Output = RET> + ~const Drop,
+   |        ^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `const_eval_select`
+
 error[E0271]: type mismatch resolving `<fn(i32) -> bool {bar} as FnOnce<(i32,)>>::Output == i32`
-  --> $DIR/const-eval-select-bad.rs:27:5
+  --> $DIR/const-eval-select-bad.rs:28:5
    |
 LL |     const_eval_select((1,), foo, bar);
    |     ^^^^^^^^^^^^^^^^^ expected `i32`, found `bool`
@@ -43,13 +59,13 @@ LL |     G: FnOnce<ARG, Output = RET> + ~const Drop,
    |                    ^^^^^^^^^^^^ required by this bound in `const_eval_select`
 
 error[E0631]: type mismatch in function arguments
-  --> $DIR/const-eval-select-bad.rs:32:37
+  --> $DIR/const-eval-select-bad.rs:33:32
    |
 LL | const fn foo(n: i32) -> i32 {
    | --------------------------- found signature of `fn(i32) -> _`
 ...
 LL |     const_eval_select((true,), foo, baz);
-   |     -----------------               ^^^ expected signature of `fn(bool) -> _`
+   |     -----------------          ^^^ expected signature of `fn(bool) -> _`
    |     |
    |     required by a bound introduced by this call
    |
@@ -59,7 +75,7 @@ note: required by a bound in `const_eval_select`
 LL |     F: ~const FnOnce<ARG, Output = RET>,
    |        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `const_eval_select`
 
-error: aborting due to 4 previous errors
+error: aborting due to 5 previous errors
 
 Some errors have detailed explanations: E0271, E0277, E0631.
 For more information about an error, try `rustc --explain E0271`.
diff --git a/src/test/ui/issues/issue-40827.stderr b/src/test/ui/issues/issue-40827.stderr
index 3b2d232e61f..11c23e5b659 100644
--- a/src/test/ui/issues/issue-40827.stderr
+++ b/src/test/ui/issues/issue-40827.stderr
@@ -1,8 +1,10 @@
 error[E0277]: `Rc<Foo>` cannot be shared between threads safely
-  --> $DIR/issue-40827.rs:14:5
+  --> $DIR/issue-40827.rs:14:7
    |
 LL |     f(Foo(Arc::new(Bar::B(None))));
-   |     ^ `Rc<Foo>` cannot be shared between threads safely
+   |     - ^^^^^^^^^^^^^^^^^^^^^^^^^^^ `Rc<Foo>` cannot be shared between threads safely
+   |     |
+   |     required by a bound introduced by this call
    |
    = help: within `Bar`, the trait `Sync` is not implemented for `Rc<Foo>`
 note: required because it appears within the type `Bar`
@@ -23,10 +25,12 @@ LL | fn f<T: Send>(_: T) {}
    |         ^^^^ required by this bound in `f`
 
 error[E0277]: `Rc<Foo>` cannot be sent between threads safely
-  --> $DIR/issue-40827.rs:14:5
+  --> $DIR/issue-40827.rs:14:7
    |
 LL |     f(Foo(Arc::new(Bar::B(None))));
-   |     ^ `Rc<Foo>` cannot be sent between threads safely
+   |     - ^^^^^^^^^^^^^^^^^^^^^^^^^^^ `Rc<Foo>` cannot be sent between threads safely
+   |     |
+   |     required by a bound introduced by this call
    |
    = help: within `Bar`, the trait `Send` is not implemented for `Rc<Foo>`
 note: required because it appears within the type `Bar`
diff --git a/src/test/ui/mut/mutable-enum-indirect.stderr b/src/test/ui/mut/mutable-enum-indirect.stderr
index 8ec478cd63f..9e1f4e1fe4e 100644
--- a/src/test/ui/mut/mutable-enum-indirect.stderr
+++ b/src/test/ui/mut/mutable-enum-indirect.stderr
@@ -1,8 +1,10 @@
 error[E0277]: `NoSync` cannot be shared between threads safely
-  --> $DIR/mutable-enum-indirect.rs:17:5
+  --> $DIR/mutable-enum-indirect.rs:17:9
    |
 LL |     bar(&x);
-   |     ^^^ `NoSync` cannot be shared between threads safely
+   |     --- ^^ `NoSync` cannot be shared between threads safely
+   |     |
+   |     required by a bound introduced by this call
    |
    = help: within `&Foo`, the trait `Sync` is not implemented for `NoSync`
 note: required because it appears within the type `Foo`
diff --git a/src/test/ui/no_send-enum.stderr b/src/test/ui/no_send-enum.stderr
index 814f3473828..b5a14b551dc 100644
--- a/src/test/ui/no_send-enum.stderr
+++ b/src/test/ui/no_send-enum.stderr
@@ -1,8 +1,10 @@
 error[E0277]: `NoSend` cannot be sent between threads safely
-  --> $DIR/no_send-enum.rs:16:5
+  --> $DIR/no_send-enum.rs:16:9
    |
 LL |     bar(x);
-   |     ^^^ `NoSend` cannot be sent between threads safely
+   |     --- ^ `NoSend` cannot be sent between threads safely
+   |     |
+   |     required by a bound introduced by this call
    |
    = help: within `Foo`, the trait `Send` is not implemented for `NoSend`
 note: required because it appears within the type `Foo`
diff --git a/src/test/ui/no_share-enum.stderr b/src/test/ui/no_share-enum.stderr
index ad837863be9..5b453e0da3b 100644
--- a/src/test/ui/no_share-enum.stderr
+++ b/src/test/ui/no_share-enum.stderr
@@ -1,8 +1,10 @@
 error[E0277]: `NoSync` cannot be shared between threads safely
-  --> $DIR/no_share-enum.rs:14:5
+  --> $DIR/no_share-enum.rs:14:9
    |
 LL |     bar(x);
-   |     ^^^ `NoSync` cannot be shared between threads safely
+   |     --- ^ `NoSync` cannot be shared between threads safely
+   |     |
+   |     required by a bound introduced by this call
    |
    = help: within `Foo`, the trait `Sync` is not implemented for `NoSync`
 note: required because it appears within the type `Foo`
diff --git a/src/test/ui/rfc-2632-const-trait-impl/const-drop-fail.precise.stderr b/src/test/ui/rfc-2632-const-trait-impl/const-drop-fail.precise.stderr
index 34cd1d2b107..efe46d7e81d 100644
--- a/src/test/ui/rfc-2632-const-trait-impl/const-drop-fail.precise.stderr
+++ b/src/test/ui/rfc-2632-const-trait-impl/const-drop-fail.precise.stderr
@@ -51,9 +51,6 @@ LL | struct ConstDropImplWithBounds<T: ~const A>(PhantomData<T>);
 error[E0277]: the trait bound `NonTrivialDrop: A` is not satisfied
   --> $DIR/const-drop-fail.rs:49:5
    |
-LL |         const _: () = check($exp);
-   |                       ----- required by a bound introduced by this call
-...
 LL |     ConstDropImplWithBounds::<NonTrivialDrop>(PhantomData),
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `A` is not implemented for `NonTrivialDrop`
    |
diff --git a/src/test/ui/rfc-2632-const-trait-impl/const-drop-fail.stock.stderr b/src/test/ui/rfc-2632-const-trait-impl/const-drop-fail.stock.stderr
index 34cd1d2b107..efe46d7e81d 100644
--- a/src/test/ui/rfc-2632-const-trait-impl/const-drop-fail.stock.stderr
+++ b/src/test/ui/rfc-2632-const-trait-impl/const-drop-fail.stock.stderr
@@ -51,9 +51,6 @@ LL | struct ConstDropImplWithBounds<T: ~const A>(PhantomData<T>);
 error[E0277]: the trait bound `NonTrivialDrop: A` is not satisfied
   --> $DIR/const-drop-fail.rs:49:5
    |
-LL |         const _: () = check($exp);
-   |                       ----- required by a bound introduced by this call
-...
 LL |     ConstDropImplWithBounds::<NonTrivialDrop>(PhantomData),
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `A` is not implemented for `NonTrivialDrop`
    |
diff --git a/src/test/ui/suggestions/into-str.stderr b/src/test/ui/suggestions/into-str.stderr
index 263d509075a..0d9ecc32e08 100644
--- a/src/test/ui/suggestions/into-str.stderr
+++ b/src/test/ui/suggestions/into-str.stderr
@@ -1,8 +1,10 @@
 error[E0277]: the trait bound `&str: From<String>` is not satisfied
-  --> $DIR/into-str.rs:4:5
+  --> $DIR/into-str.rs:4:9
    |
 LL |     foo(String::new());
-   |     ^^^ the trait `From<String>` is not implemented for `&str`
+   |     --- ^^^^^^^^^^^^^ the trait `From<String>` is not implemented for `&str`
+   |     |
+   |     required by a bound introduced by this call
    |
    = note: to coerce a `String` into a `&str`, use `&*` as a prefix
    = note: required because of the requirements on the impl of `Into<&str>` for `String`
diff --git a/src/test/ui/traits/issue-71136.stderr b/src/test/ui/traits/issue-71136.stderr
index 23b78d023b6..d1e8affd065 100644
--- a/src/test/ui/traits/issue-71136.stderr
+++ b/src/test/ui/traits/issue-71136.stderr
@@ -5,7 +5,7 @@ LL | #[derive(Clone)]
    |          ----- in this derive macro expansion
 LL | struct FooHolster {
 LL |     the_foos: Vec<Foo>,
-   |     ^^^^^^^^^^^^^^^^^^ expected an implementor of trait `Clone`
+   |     ^^^^^^^^^^^^^^^^^^ the trait `Clone` is not implemented for `Foo`
    |
    = note: required because of the requirements on the impl of `Clone` for `Vec<Foo>`
 note: required by `clone`
diff --git a/src/test/ui/traits/negative-impls/negated-auto-traits-error.stderr b/src/test/ui/traits/negative-impls/negated-auto-traits-error.stderr
index 8059a8ca71e..1cf73fcdebd 100644
--- a/src/test/ui/traits/negative-impls/negated-auto-traits-error.stderr
+++ b/src/test/ui/traits/negative-impls/negated-auto-traits-error.stderr
@@ -49,7 +49,7 @@ LL |     is_send((8, TestType));
    |     |
    |     required by a bound introduced by this call
    |
-   = help: the trait `Send` is not implemented for `dummy1c::TestType`
+   = help: within `({integer}, dummy1c::TestType)`, the trait `Send` is not implemented for `dummy1c::TestType`
    = note: required because it appears within the type `({integer}, dummy1c::TestType)`
 note: required by a bound in `is_send`
   --> $DIR/negated-auto-traits-error.rs:16:15
@@ -86,7 +86,7 @@ LL |     is_send(Box::new(Outer2(TestType)));
    |     |
    |     required by a bound introduced by this call
    |
-   = help: the trait `Send` is not implemented for `dummy3::TestType`
+   = help: within `Outer2<dummy3::TestType>`, the trait `Send` is not implemented for `dummy3::TestType`
 note: required because it appears within the type `Outer2<dummy3::TestType>`
   --> $DIR/negated-auto-traits-error.rs:12:8
    |
diff --git a/src/test/ui/type-alias-impl-trait/auto-trait-leakage2.stderr b/src/test/ui/type-alias-impl-trait/auto-trait-leakage2.stderr
index d60be4b1ccf..4a49d6e4ab8 100644
--- a/src/test/ui/type-alias-impl-trait/auto-trait-leakage2.stderr
+++ b/src/test/ui/type-alias-impl-trait/auto-trait-leakage2.stderr
@@ -1,11 +1,13 @@
 error[E0277]: `Rc<u32>` cannot be sent between threads safely
-  --> $DIR/auto-trait-leakage2.rs:17:5
+  --> $DIR/auto-trait-leakage2.rs:17:13
    |
 LL |     type Foo = impl std::fmt::Debug;
    |                -------------------- within this `impl Debug`
 ...
 LL |     is_send(m::foo());
-   |     ^^^^^^^ `Rc<u32>` cannot be sent between threads safely
+   |     ------- ^^^^^^^^ `Rc<u32>` cannot be sent between threads safely
+   |     |
+   |     required by a bound introduced by this call
    |
    = help: within `impl Debug`, the trait `Send` is not implemented for `Rc<u32>`
    = note: required because it appears within the type `impl Debug`
diff --git a/src/test/ui/typeck/issue-90101.rs b/src/test/ui/typeck/issue-90101.rs
new file mode 100644
index 00000000000..1954ee6f1e7
--- /dev/null
+++ b/src/test/ui/typeck/issue-90101.rs
@@ -0,0 +1,8 @@
+use std::path::{Path, PathBuf};
+
+fn func(path: impl Into<PathBuf>, code: impl Into<String>) {}
+
+fn main() {
+    func(Path::new("hello").to_path_buf().to_string_lossy(), "world")
+    //~^ ERROR [E0277]
+}
diff --git a/src/test/ui/typeck/issue-90101.stderr b/src/test/ui/typeck/issue-90101.stderr
new file mode 100644
index 00000000000..998b636887f
--- /dev/null
+++ b/src/test/ui/typeck/issue-90101.stderr
@@ -0,0 +1,24 @@
+error[E0277]: the trait bound `PathBuf: From<Cow<'_, str>>` is not satisfied
+  --> $DIR/issue-90101.rs:6:10
+   |
+LL |     func(Path::new("hello").to_path_buf().to_string_lossy(), "world")
+   |     ---- ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `From<Cow<'_, str>>` is not implemented for `PathBuf`
+   |     |
+   |     required by a bound introduced by this call
+   |
+   = help: the following implementations were found:
+             <PathBuf as From<&T>>
+             <PathBuf as From<Box<Path>>>
+             <PathBuf as From<Cow<'a, Path>>>
+             <PathBuf as From<OsString>>
+             <PathBuf as From<String>>
+   = note: required because of the requirements on the impl of `Into<PathBuf>` for `Cow<'_, str>`
+note: required by a bound in `func`
+  --> $DIR/issue-90101.rs:3:20
+   |
+LL | fn func(path: impl Into<PathBuf>, code: impl Into<String>) {}
+   |                    ^^^^^^^^^^^^^ required by this bound in `func`
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0277`.
diff --git a/src/test/ui/typeck/typeck-unsafe-always-share.stderr b/src/test/ui/typeck/typeck-unsafe-always-share.stderr
index 4b5804253b2..154e504996b 100644
--- a/src/test/ui/typeck/typeck-unsafe-always-share.stderr
+++ b/src/test/ui/typeck/typeck-unsafe-always-share.stderr
@@ -29,10 +29,12 @@ LL | fn test<T: Sync>(s: T) {}
    |            ^^^^ required by this bound in `test`
 
 error[E0277]: `UnsafeCell<NoSync>` cannot be shared between threads safely
-  --> $DIR/typeck-unsafe-always-share.rs:27:5
+  --> $DIR/typeck-unsafe-always-share.rs:27:10
    |
 LL |     test(ms);
-   |     ^^^^ `UnsafeCell<NoSync>` cannot be shared between threads safely
+   |     ---- ^^ `UnsafeCell<NoSync>` cannot be shared between threads safely
+   |     |
+   |     required by a bound introduced by this call
    |
    = help: within `MySync<NoSync>`, the trait `Sync` is not implemented for `UnsafeCell<NoSync>`
 note: required because it appears within the type `MySync<NoSync>`
diff --git a/src/test/ui/unsized-locals/unsized-exprs.stderr b/src/test/ui/unsized-locals/unsized-exprs.stderr
index 6686e55130f..6960255d987 100644
--- a/src/test/ui/unsized-locals/unsized-exprs.stderr
+++ b/src/test/ui/unsized-locals/unsized-exprs.stderr
@@ -16,7 +16,7 @@ LL |     udrop::<A<[u8]>>(A { 0: *foo() });
    |     |
    |     required by a bound introduced by this call
    |
-   = help: the trait `Sized` is not implemented for `[u8]`
+   = help: within `A<[u8]>`, the trait `Sized` is not implemented for `[u8]`
 note: required because it appears within the type `A<[u8]>`
   --> $DIR/unsized-exprs.rs:3:8
    |