rust-lang · bors · Jan 12, 2023 · Jan 11, 2023
diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs
@@ -36,7 +36,7 @@ use rustc_middle::ty::{
     TypeSuperFoldable, TypeVisitable, TypeckResults,
 };
 use rustc_span::symbol::{sym, Ident, Symbol};
-use rustc_span::{BytePos, DesugaringKind, ExpnKind, Span, DUMMY_SP};
+use rustc_span::{BytePos, DesugaringKind, ExpnKind, MacroKind, Span, DUMMY_SP};
 use rustc_target::spec::abi;
 use std::ops::Deref;
 
@@ -2949,7 +2949,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
                         // FIXME: we should do something else so that it works even on crate foreign
                         // auto traits.
                         is_auto_trait = matches!(is_auto, hir::IsAuto::Yes);
-                        err.span_note(ident.span, &msg)
+                        err.span_note(ident.span, &msg);
                     }
                     Some(Node::Item(hir::Item {
                         kind: hir::ItemKind::Impl(hir::Impl { of_trait, self_ty, .. }),
@@ -2960,9 +2960,29 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
                             spans.push(trait_ref.path.span);
                         }
                         spans.push(self_ty.span);
-                        err.span_note(spans, &msg)
+                        let mut spans: MultiSpan = spans.into();
+                        if matches!(
+                            self_ty.span.ctxt().outer_expn_data().kind,
+                            ExpnKind::Macro(MacroKind::Derive, _)
+                        ) || matches!(
+                            of_trait.as_ref().map(|t| t.path.span.ctxt().outer_expn_data().kind),
+                            Some(ExpnKind::Macro(MacroKind::Derive, _))
+                        ) {
+                            spans.push_span_label(
+                                data.span,
+                                "unsatisfied trait bound introduced in this `derive` macro",
+                            );
+                        } else if !data.span.is_dummy() && !data.span.overlaps(self_ty.span) {
+                            spans.push_span_label(
+                                data.span,
+                                "unsatisfied trait bound introduced here",
+                            );
+                        }
+                        err.span_note(spans, &msg);
+                    }
+                    _ => {
+                        err.note(&msg);
                     }
-                    _ => err.note(&msg),
                 };
 
                 if let Some(file) = file {

diff --git a/tests/ui/associated-types/hr-associated-type-bound-2.stderr b/tests/ui/associated-types/hr-associated-type-bound-2.stderr
@@ -10,6 +10,9 @@ note: required for `u32` to implement `for<'b> X<'b>`
    |
 LL | impl X<'_> for u32
    |      ^^^^^     ^^^
+LL | where
+LL |     for<'b> <Self as X<'b>>::U: Clone,
+   |                                 ----- unsatisfied trait bound introduced here
    = note: 128 redundant requirements hidden
    = note: required for `u32` to implement `for<'b> X<'b>`
 

diff --git a/tests/ui/associated-types/impl-wf-cycle-1.stderr b/tests/ui/associated-types/impl-wf-cycle-1.stderr
@@ -9,6 +9,9 @@ note: required for `(T,)` to implement `Grault`
    |
 LL | impl<T: Grault> Grault for (T,)
    |                 ^^^^^^     ^^^^
+...
+LL |     Self::A: Baz,
+   |              --- unsatisfied trait bound introduced here
    = note: 1 redundant requirement hidden
    = note: required for `(T,)` to implement `Grault`
 

diff --git a/tests/ui/associated-types/impl-wf-cycle-2.stderr b/tests/ui/associated-types/impl-wf-cycle-2.stderr
@@ -9,6 +9,9 @@ note: required for `(T,)` to implement `Grault`
    |
 LL | impl<T: Grault> Grault for (T,)
    |                 ^^^^^^     ^^^^
+...
+LL |     Self::A: Copy,
+   |              ---- unsatisfied trait bound introduced here
 
 error: aborting due to previous error
 

diff --git a/tests/ui/associated-types/issue-44153.stderr b/tests/ui/associated-types/issue-44153.stderr
@@ -14,6 +14,8 @@ note: required for `()` to implement `Visit`
    |
 LL | impl<'a> Visit for () where
    |          ^^^^^     ^^
+LL |     (): Array<Element=&'a ()>,
+   |               -------------- unsatisfied trait bound introduced here
 
 error: aborting due to previous error
 

diff --git a/tests/ui/associated-types/issue-65774-1.stderr b/tests/ui/associated-types/issue-65774-1.stderr
@@ -22,7 +22,9 @@ note: required for `&mut T` to implement `MyDisplay`
   --> $DIR/issue-65774-1.rs:5:24
    |
 LL | impl<'a, T: MyDisplay> MyDisplay for &'a mut T { }
-   |                        ^^^^^^^^^     ^^^^^^^^^
+   |             ---------  ^^^^^^^^^     ^^^^^^^^^
+   |             |
+   |             unsatisfied trait bound introduced here
    = note: required for the cast from `&mut T` to the object type `dyn MyDisplay`
 
 error: aborting due to 2 previous errors

diff --git a/tests/ui/associated-types/substs-ppaux.normal.stderr b/tests/ui/associated-types/substs-ppaux.normal.stderr
@@ -81,7 +81,9 @@ note: required for `str` to implement `Foo<'_, '_, u8>`
   --> $DIR/substs-ppaux.rs:11:17
    |
 LL | impl<'a,'b,T,S> Foo<'a, 'b, S> for T {}
-   |                 ^^^^^^^^^^^^^^     ^
+   |            -    ^^^^^^^^^^^^^^     ^
+   |            |
+   |            unsatisfied trait bound introduced here
 
 error: aborting due to 5 previous errors
 

diff --git a/tests/ui/associated-types/substs-ppaux.verbose.stderr b/tests/ui/associated-types/substs-ppaux.verbose.stderr
@@ -81,7 +81,9 @@ note: required for `str` to implement `Foo<'_#0r, '_#1r, u8>`
   --> $DIR/substs-ppaux.rs:11:17
    |
 LL | impl<'a,'b,T,S> Foo<'a, 'b, S> for T {}
-   |                 ^^^^^^^^^^^^^^     ^
+   |            -    ^^^^^^^^^^^^^^     ^
+   |            |
+   |            unsatisfied trait bound introduced here
 
 error: aborting due to 5 previous errors
 

diff --git a/tests/ui/auto-traits/typeck-default-trait-impl-precedence.stderr b/tests/ui/auto-traits/typeck-default-trait-impl-precedence.stderr
@@ -9,7 +9,9 @@ note: required for `&'static u32` to implement `Defaulted`
   --> $DIR/typeck-default-trait-impl-precedence.rs:10:19
    |
 LL | impl<'a,T:Signed> Defaulted for &'a T { }
-   |                   ^^^^^^^^^     ^^^^^
+   |           ------  ^^^^^^^^^     ^^^^^
+   |           |
+   |           unsatisfied trait bound introduced here
 note: required by a bound in `is_defaulted`
   --> $DIR/typeck-default-trait-impl-precedence.rs:12:19
    |

diff --git a/tests/ui/block-result/issue-22645.stderr b/tests/ui/block-result/issue-22645.stderr
@@ -9,7 +9,9 @@ note: required for `Bob` to implement `Add<{integer}>`
   --> $DIR/issue-22645.rs:8:19
    |
 LL | impl<RHS: Scalar> Add <RHS> for Bob {
-   |                   ^^^^^^^^^     ^^^
+   |           ------  ^^^^^^^^^     ^^^
+   |           |
+   |           unsatisfied trait bound introduced here
 
 error[E0308]: mismatched types
   --> $DIR/issue-22645.rs:15:3

diff --git a/tests/ui/const-generics/generic_const_exprs/issue-85848.stderr b/tests/ui/const-generics/generic_const_exprs/issue-85848.stderr
@@ -11,12 +11,12 @@ note: required for `&C` to implement `Contains<(), true>`
   --> $DIR/issue-85848.rs:21:12
    |
 LL | impl<T, U> Contains<T, { contains::<T, U>() }> for U where T: _Contains<U> {}
-   |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^     ^
+   |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^     ^          ------------ unsatisfied trait bound introduced here
 note: required for `&C` to implement `Delegates<()>`
   --> $DIR/issue-85848.rs:12:12
    |
 LL | impl<T, U> Delegates<U> for T where T: Contains<U, true> {}
-   |            ^^^^^^^^^^^^     ^
+   |            ^^^^^^^^^^^^     ^          ----------------- unsatisfied trait bound introduced here
 note: required by a bound in `writes_to_specific_path`
   --> $DIR/issue-85848.rs:30:31
    |
@@ -36,12 +36,14 @@ note: required for `&C` to implement `Contains<(), true>`
   --> $DIR/issue-85848.rs:21:12
    |
 LL | impl<T, U> Contains<T, { contains::<T, U>() }> for U where T: _Contains<U> {}
-   |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^     ^
+   |            ^^^^^^^^^^^^----------------------^     ^
+   |                        |
+   |                        unsatisfied trait bound introduced here
 note: required for `&C` to implement `Delegates<()>`
   --> $DIR/issue-85848.rs:12:12
    |
 LL | impl<T, U> Delegates<U> for T where T: Contains<U, true> {}
-   |            ^^^^^^^^^^^^     ^
+   |            ^^^^^^^^^^^^     ^          ----------------- unsatisfied trait bound introduced here
 note: required by a bound in `writes_to_specific_path`
   --> $DIR/issue-85848.rs:30:31
    |

diff --git a/tests/ui/consts/const-blocks/trait-error.stderr b/tests/ui/consts/const-blocks/trait-error.stderr
@@ -8,7 +8,7 @@ note: required for `Foo<String>` to implement `Copy`
   --> $DIR/trait-error.rs:1:10
    |
 LL | #[derive(Copy, Clone)]
-   |          ^^^^
+   |          ^^^^ unsatisfied trait bound introduced in this `derive` macro
    = note: the `Copy` trait is required because this value will be copied for each element of the array
    = help: consider creating a new `const` item and initializing it with the result of the function call to be used in the repeat position, like `const VAL: Type = const_fn();` and `let x = [VAL; 42];`
    = help: create an inline `const` block, see RFC #2920 <https://github.com/rust-lang/rfcs/pull/2920> for more information

diff --git a/tests/ui/derives/deriving-copyclone.stderr b/tests/ui/derives/deriving-copyclone.stderr
@@ -10,7 +10,7 @@ note: required for `B<C>` to implement `Copy`
   --> $DIR/deriving-copyclone.rs:9:10
    |
 LL | #[derive(Copy, Clone)]
-   |          ^^^^
+   |          ^^^^ unsatisfied trait bound introduced in this `derive` macro
 note: required by a bound in `is_copy`
   --> $DIR/deriving-copyclone.rs:18:15
    |
@@ -34,7 +34,7 @@ note: required for `B<C>` to implement `Clone`
   --> $DIR/deriving-copyclone.rs:9:16
    |
 LL | #[derive(Copy, Clone)]
-   |                ^^^^^
+   |                ^^^^^ unsatisfied trait bound introduced in this `derive` macro
 note: required by a bound in `is_clone`
   --> $DIR/deriving-copyclone.rs:19:16
    |
@@ -58,7 +58,7 @@ note: required for `B<D>` to implement `Copy`
   --> $DIR/deriving-copyclone.rs:9:10
    |
 LL | #[derive(Copy, Clone)]
-   |          ^^^^
+   |          ^^^^ unsatisfied trait bound introduced in this `derive` macro
 note: required by a bound in `is_copy`
   --> $DIR/deriving-copyclone.rs:18:15
    |

diff --git a/tests/ui/error-codes/E0275.stderr b/tests/ui/error-codes/E0275.stderr
@@ -9,7 +9,7 @@ note: required for `Bar<Bar<Bar<Bar<Bar<Bar<Bar<Bar<Bar<Bar<Bar<Bar<Bar<Bar<Bar<
   --> $DIR/E0275.rs:6:9
    |
 LL | impl<T> Foo for T where Bar<T>: Foo {}
-   |         ^^^     ^
+   |         ^^^     ^               --- unsatisfied trait bound introduced here
    = note: the full type name has been written to '$TEST_BUILD_DIR/error-codes/E0275/E0275.long-type-hash.txt'
    = note: 127 redundant requirements hidden
    = note: required for `Bar<T>` to implement `Foo`

diff --git a/tests/ui/generic-associated-types/impl_bounds.stderr b/tests/ui/generic-associated-types/impl_bounds.stderr
@@ -31,7 +31,7 @@ note: required for `Fooy<T>` to implement `Copy`
   --> $DIR/impl_bounds.rs:10:10
    |
 LL | #[derive(Copy, Clone)]
-   |          ^^^^
+   |          ^^^^ unsatisfied trait bound introduced in this `derive` macro
 note: the requirement `Fooy<T>: Copy` appears on the `impl`'s associated type `C` but not on the corresponding trait's associated type
   --> $DIR/impl_bounds.rs:6:10
    |
@@ -56,7 +56,7 @@ note: required for `Fooy<T>` to implement `Copy`
   --> $DIR/impl_bounds.rs:10:10
    |
 LL | #[derive(Copy, Clone)]
-   |          ^^^^
+   |          ^^^^ unsatisfied trait bound introduced in this `derive` macro
 note: the requirement `Fooy<T>: Copy` appears on the `impl`'s method `d` but not on the corresponding trait's method
   --> $DIR/impl_bounds.rs:7:8
    |

diff --git a/tests/ui/generic-associated-types/issue-101020.stderr b/tests/ui/generic-associated-types/issue-101020.stderr
@@ -8,7 +8,7 @@ note: required for `&'a mut ()` to implement `for<'a> FuncInput<'a, &'a mut ()>`
   --> $DIR/issue-101020.rs:27:20
    |
 LL | impl<'a, T, F: 'a> FuncInput<'a, F> for T where F: Foo<T> {}
-   |                    ^^^^^^^^^^^^^^^^     ^
+   |                    ^^^^^^^^^^^^^^^^     ^          ------ unsatisfied trait bound introduced here
 note: required by a bound in `LendingIterator::consume`
   --> $DIR/issue-101020.rs:9:33
    |

diff --git a/tests/ui/higher-rank-trait-bounds/issue-62203-hrtb-ice.stderr b/tests/ui/higher-rank-trait-bounds/issue-62203-hrtb-ice.stderr
@@ -49,6 +49,9 @@ note: required for `L<[closure@$DIR/issue-62203-hrtb-ice.rs:42:16: 42:19]>` to i
    |
 LL | impl<'a, A, T> T0<'a, A> for L<T>
    |                ^^^^^^^^^     ^^^^
+LL | where
+LL |     T: FnMut(A) -> Unit3,
+   |                    ----- unsatisfied trait bound introduced here
 note: required by a bound in `T1::m`
   --> $DIR/issue-62203-hrtb-ice.rs:27:12
    |

diff --git a/tests/ui/higher-rank-trait-bounds/normalize-under-binder/issue-89118.stderr b/tests/ui/higher-rank-trait-bounds/normalize-under-binder/issue-89118.stderr
@@ -8,7 +8,9 @@ note: required for `Ctx<()>` to implement `for<'a> BufferUdpStateContext<&'a ()>
   --> $DIR/issue-89118.rs:5:23
    |
 LL | impl<B: BufferMut, C> BufferUdpStateContext<B> for C {}
-   |                       ^^^^^^^^^^^^^^^^^^^^^^^^     ^
+   |         ---------     ^^^^^^^^^^^^^^^^^^^^^^^^     ^
+   |         |
+   |         unsatisfied trait bound introduced here
 note: required by a bound in `StackContext`
   --> $DIR/issue-89118.rs:9:14
    |
@@ -28,7 +30,9 @@ note: required for `Ctx<()>` to implement `for<'a> BufferUdpStateContext<&'a ()>
   --> $DIR/issue-89118.rs:5:23
    |
 LL | impl<B: BufferMut, C> BufferUdpStateContext<B> for C {}
-   |                       ^^^^^^^^^^^^^^^^^^^^^^^^     ^
+   |         ---------     ^^^^^^^^^^^^^^^^^^^^^^^^     ^
+   |         |
+   |         unsatisfied trait bound introduced here
 note: required by a bound in `EthernetWorker`
   --> $DIR/issue-89118.rs:28:14
    |
@@ -48,7 +52,9 @@ note: required for `Ctx<()>` to implement `for<'a> BufferUdpStateContext<&'a ()>
   --> $DIR/issue-89118.rs:5:23
    |
 LL | impl<B: BufferMut, C> BufferUdpStateContext<B> for C {}
-   |                       ^^^^^^^^^^^^^^^^^^^^^^^^     ^
+   |         ---------     ^^^^^^^^^^^^^^^^^^^^^^^^     ^
+   |         |
+   |         unsatisfied trait bound introduced here
 note: required by a bound in `StackContext`
   --> $DIR/issue-89118.rs:9:14
    |

diff --git a/tests/ui/impl-trait/nested-return-type2-tait2.stderr b/tests/ui/impl-trait/nested-return-type2-tait2.stderr
@@ -9,7 +9,9 @@ note: required for `[closure@$DIR/nested-return-type2-tait2.rs:27:5: 27:7]` to i
   --> $DIR/nested-return-type2-tait2.rs:14:31
    |
 LL | impl<R: Duh, F: FnMut() -> R> Trait for F {
-   |                               ^^^^^     ^
+   |         ---                   ^^^^^     ^
+   |         |
+   |         unsatisfied trait bound introduced here
 
 error: aborting due to previous error
 

diff --git a/tests/ui/impl-trait/nested-return-type2-tait3.stderr b/tests/ui/impl-trait/nested-return-type2-tait3.stderr
@@ -9,7 +9,9 @@ note: required for `[closure@$DIR/nested-return-type2-tait3.rs:26:5: 26:7]` to i
   --> $DIR/nested-return-type2-tait3.rs:14:31
    |
 LL | impl<R: Duh, F: FnMut() -> R> Trait for F {
-   |                               ^^^^^     ^
+   |         ---                   ^^^^^     ^
+   |         |
+   |         unsatisfied trait bound introduced here
 
 error: aborting due to previous error
 

diff --git a/tests/ui/impl-trait/projection-mismatch-in-impl-where-clause.stderr b/tests/ui/impl-trait/projection-mismatch-in-impl-where-clause.stderr
@@ -13,7 +13,7 @@ note: required for `()` to implement `Test`
   --> $DIR/projection-mismatch-in-impl-where-clause.rs:11:9
    |
 LL | impl<T> Test for T where T: Super<Assoc = ()> {}
-   |         ^^^^     ^
+   |         ^^^^     ^                ---------- unsatisfied trait bound introduced here
 
 error: aborting due to previous error
 

diff --git a/tests/ui/inference/issue-80816.rs b/tests/ui/inference/issue-80816.rs
@@ -30,6 +30,7 @@ pub trait Access<T> {
 }
 impl<T, A: Access<T>, P: Deref<Target = A>> Access<T> for P {
     //~^ NOTE: required for `Arc<ArcSwapAny<Arc<usize>>>` to implement `Access<_>`
+    //~| NOTE unsatisfied trait bound introduced here
     type Guard = A::Guard;
 }
 impl<T> Access<T> for ArcSwapAny<T> {

diff --git a/tests/ui/inference/issue-80816.stderr b/tests/ui/inference/issue-80816.stderr
@@ -1,11 +1,11 @@
 error[E0283]: type annotations needed
-  --> $DIR/issue-80816.rs:49:38
+  --> $DIR/issue-80816.rs:50:38
    |
 LL |     let guard: Guard<Arc<usize>> = s.load();
    |                                      ^^^^
    |
 note: multiple `impl`s satisfying `ArcSwapAny<Arc<usize>>: Access<_>` found
-  --> $DIR/issue-80816.rs:35:1
+  --> $DIR/issue-80816.rs:36:1
    |
 LL | impl<T> Access<T> for ArcSwapAny<T> {
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -16,7 +16,9 @@ note: required for `Arc<ArcSwapAny<Arc<usize>>>` to implement `Access<_>`
   --> $DIR/issue-80816.rs:31:45
    |
 LL | impl<T, A: Access<T>, P: Deref<Target = A>> Access<T> for P {
-   |                                             ^^^^^^^^^     ^
+   |            ---------                        ^^^^^^^^^     ^
+   |            |
+   |            unsatisfied trait bound introduced here
 help: try using a fully qualified path to specify the expected types
    |
 LL |     let guard: Guard<Arc<usize>> = <Arc<ArcSwapAny<Arc<usize>>> as Access<T>>::load(&s);

diff --git a/tests/ui/issues/issue-20413.stderr b/tests/ui/issues/issue-20413.stderr
@@ -18,7 +18,7 @@ note: required for `NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoDa
   --> $DIR/issue-20413.rs:9:9
    |
 LL | impl<T> Foo for T where NoData<T>: Foo {
-   |         ^^^     ^
+   |         ^^^     ^                  --- unsatisfied trait bound introduced here
    = note: the full type name has been written to '$TEST_BUILD_DIR/issues/issue-20413/issue-20413.long-type-hash.txt'
    = note: 127 redundant requirements hidden
    = note: required for `NoData<T>` to implement `Foo`
@@ -34,13 +34,13 @@ note: required for `AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNo
   --> $DIR/issue-20413.rs:28:9
    |
 LL | impl<T> Bar for T where EvenLessData<T>: Baz {
-   |         ^^^     ^
+   |         ^^^     ^                        --- unsatisfied trait bound introduced here
    = note: the full type name has been written to '$TEST_BUILD_DIR/issues/issue-20413/issue-20413.long-type-hash.txt'
 note: required for `EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<...>>>>>>>` to implement `Baz`
   --> $DIR/issue-20413.rs:35:9
    |
 LL | impl<T> Baz for T where AlmostNoData<T>: Bar {
-   |         ^^^     ^
+   |         ^^^     ^                        --- unsatisfied trait bound introduced here
    = note: the full type name has been written to '$TEST_BUILD_DIR/issues/issue-20413/issue-20413.long-type-hash.txt'
    = note: 126 redundant requirements hidden
    = note: required for `EvenLessData<T>` to implement `Baz`
@@ -56,13 +56,13 @@ note: required for `EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLess
   --> $DIR/issue-20413.rs:35:9
    |
 LL | impl<T> Baz for T where AlmostNoData<T>: Bar {
-   |         ^^^     ^
+   |         ^^^     ^                        --- unsatisfied trait bound introduced here
    = note: the full type name has been written to '$TEST_BUILD_DIR/issues/issue-20413/issue-20413.long-type-hash.txt'
 note: required for `AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<...>>>>>>>` to implement `Bar`
   --> $DIR/issue-20413.rs:28:9
    |
 LL | impl<T> Bar for T where EvenLessData<T>: Baz {
-   |         ^^^     ^
+   |         ^^^     ^                        --- unsatisfied trait bound introduced here
    = note: the full type name has been written to '$TEST_BUILD_DIR/issues/issue-20413/issue-20413.long-type-hash.txt'
    = note: 126 redundant requirements hidden
    = note: required for `AlmostNoData<T>` to implement `Bar`