Handle more cases

35 files changed, 134 insertions, 91 deletions

diff --git a/src/librustc/traits/error_reporting.rs b/src/librustc/traits/error_reporting.rs
index b7c7fd4729f..a717fb7f7c0 100644
--- a/src/librustc/traits/error_reporting.rs
+++ b/src/librustc/traits/error_reporting.rs
@@ -969,7 +969,16 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
         trait_ref: &ty::PolyTraitRef<'_>,
         body_id: hir::HirId,
     ) {
-        let node = self.tcx.hir().find(self.tcx.hir().get_parent_item(body_id));
+        let node = self.tcx.hir()
+            .find(self.tcx.hir().get_parent_item(body_id))
+            .or_else(|| self.tcx.hir().find(body_id));
+        debug!(
+            "suggest_restricting_param_bound node={:?} - trait_ref={:?} ty={:?} ({:?})",
+            node,
+            trait_ref,
+            trait_ref.self_ty(),
+            trait_ref.self_ty().kind,
+        );
         if let ty::Param(param_ty) = &trait_ref.self_ty().kind {
             let restrict_msg = "consider further restricting this bound";
             let param_name = param_ty.name.as_str();
diff --git a/src/test/ui/builtin-superkinds/builtin-superkinds-double-superkind.stderr b/src/test/ui/builtin-superkinds/builtin-superkinds-double-superkind.stderr
index 9771436d167..5be6ab05d66 100644
--- a/src/test/ui/builtin-superkinds/builtin-superkinds-double-superkind.stderr
+++ b/src/test/ui/builtin-superkinds/builtin-superkinds-double-superkind.stderr
@@ -2,20 +2,22 @@ error[E0277]: `T` cannot be sent between threads safely
   --> $DIR/builtin-superkinds-double-superkind.rs:6:24
    |
 LL | impl <T: Sync+'static> Foo for (T,) { }
-   |                        ^^^ `T` cannot be sent between threads safely
+   |       --               ^^^ `T` cannot be sent between threads safely
+   |       |
+   |       help: consider further restricting this bound: `T: std::marker::Send +`
    |
    = help: within `(T,)`, the trait `std::marker::Send` is not implemented for `T`
-   = help: consider adding a `where T: std::marker::Send` bound
    = note: required because it appears within the type `(T,)`
 
 error[E0277]: `T` cannot be shared between threads safely
   --> $DIR/builtin-superkinds-double-superkind.rs:9:16
    |
 LL | impl <T: Send> Foo for (T,T) { }
-   |                ^^^ `T` cannot be shared between threads safely
+   |       --       ^^^ `T` cannot be shared between threads safely
+   |       |
+   |       help: consider further restricting this bound: `T: std::marker::Sync +`
    |
    = help: within `(T, T)`, the trait `std::marker::Sync` is not implemented for `T`
-   = help: consider adding a `where T: std::marker::Sync` bound
    = note: required because it appears within the type `(T, T)`
 
 error: aborting due to 2 previous errors
diff --git a/src/test/ui/builtin-superkinds/builtin-superkinds-in-metadata.stderr b/src/test/ui/builtin-superkinds/builtin-superkinds-in-metadata.stderr
index 61c18a24fb0..8cce9bfdf52 100644
--- a/src/test/ui/builtin-superkinds/builtin-superkinds-in-metadata.stderr
+++ b/src/test/ui/builtin-superkinds/builtin-superkinds-in-metadata.stderr
@@ -2,10 +2,11 @@ error[E0277]: `T` cannot be sent between threads safely
   --> $DIR/builtin-superkinds-in-metadata.rs:13:23
    |
 LL | impl <T:Sync+'static> RequiresRequiresShareAndSend for X<T> { }
-   |                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `T` cannot be sent between threads safely
+   |       --              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `T` cannot be sent between threads safely
+   |       |
+   |       help: consider further restricting this bound: `T: std::marker::Send +`
    |
    = help: within `X<T>`, the trait `std::marker::Send` is not implemented for `T`
-   = help: consider adding a `where T: std::marker::Send` bound
    = note: required because it appears within the type `X<T>`
 
 error: aborting due to previous error
diff --git a/src/test/ui/builtin-superkinds/builtin-superkinds-typaram-not-send.stderr b/src/test/ui/builtin-superkinds/builtin-superkinds-typaram-not-send.stderr
index dc5479e5e2d..4381a5b8682 100644
--- a/src/test/ui/builtin-superkinds/builtin-superkinds-typaram-not-send.stderr
+++ b/src/test/ui/builtin-superkinds/builtin-superkinds-typaram-not-send.stderr
@@ -2,10 +2,11 @@ error[E0277]: `T` cannot be sent between threads safely
   --> $DIR/builtin-superkinds-typaram-not-send.rs:5:24
    |
 LL | impl <T: Sync+'static> Foo for T { }
-   |                        ^^^ `T` cannot be sent between threads safely
+   |       --               ^^^ `T` cannot be sent between threads safely
+   |       |
+   |       help: consider further restricting this bound: `T: std::marker::Send +`
    |
    = help: the trait `std::marker::Send` is not implemented for `T`
-   = help: consider adding a `where T: std::marker::Send` bound
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/closures/closure-bounds-cant-promote-superkind-in-struct.stderr b/src/test/ui/closures/closure-bounds-cant-promote-superkind-in-struct.stderr
index 51077b1b292..3c8f637e133 100644
--- a/src/test/ui/closures/closure-bounds-cant-promote-superkind-in-struct.stderr
+++ b/src/test/ui/closures/closure-bounds-cant-promote-superkind-in-struct.stderr
@@ -4,14 +4,16 @@ error[E0277]: `F` cannot be sent between threads safely
 LL |   struct X<F> where F: FnOnce() + 'static + Send {
    |   ---------------------------------------------- required by `X`
 ...
-LL | / fn foo<F>(blk: F) -> X<F> where F: FnOnce() + 'static {
+LL |   fn foo<F>(blk: F) -> X<F> where F: FnOnce() + 'static {
+   |   ^                                                    - help: consider further restricting type parameter `F`: `, F: std::marker::Send`
+   |  _|
+   | |
 LL | |
 LL | |     return X { field: blk };
 LL | | }
    | |_^ `F` cannot be sent between threads safely
    |
    = help: the trait `std::marker::Send` is not implemented for `F`
-   = help: consider adding a `where F: std::marker::Send` bound
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/issues/issue-21837.stderr b/src/test/ui/issues/issue-21837.stderr
index 20d02a90315..50fdf2d6185 100644
--- a/src/test/ui/issues/issue-21837.stderr
+++ b/src/test/ui/issues/issue-21837.stderr
@@ -5,9 +5,9 @@ LL | pub struct Foo<T: Bound>(T);
    | ---------------------------- required by `Foo`
 ...
 LL | impl<T> Trait2 for Foo<T> {}
-   |         ^^^^^^ the trait `Bound` is not implemented for `T`
-   |
-   = help: consider adding a `where T: Bound` bound
+   |      -  ^^^^^^ the trait `Bound` is not implemented for `T`
+   |      |
+   |      help: consider restricting this bound: `T: Bound`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/issues/issue-27060-2.stderr b/src/test/ui/issues/issue-27060-2.stderr
index f7227c34101..553041c5106 100644
--- a/src/test/ui/issues/issue-27060-2.stderr
+++ b/src/test/ui/issues/issue-27060-2.stderr
@@ -1,12 +1,13 @@
 error[E0277]: the size for values of type `T` cannot be known at compilation time
   --> $DIR/issue-27060-2.rs:3:5
    |
+LL | pub struct Bad<T: ?Sized> {
+   |                -- help: consider further restricting this bound: `T: std::marker::Sized +`
 LL |     data: T,
    |     ^^^^^^^ doesn't have a size known at compile-time
    |
    = help: the trait `std::marker::Sized` is not implemented for `T`
    = note: to learn more, visit <https://doc.rust-lang.org/book/ch19-04-advanced-types.html#dynamically-sized-types-and-the-sized-trait>
-   = help: consider adding a `where T: std::marker::Sized` bound
    = note: the last field of a packed struct may only have a dynamically sized type if it does not need drop to be run
 
 error: aborting due to previous error
diff --git a/src/test/ui/issues/issue-43784-associated-type.stderr b/src/test/ui/issues/issue-43784-associated-type.stderr
index fc05d280693..e91e53499ce 100644
--- a/src/test/ui/issues/issue-43784-associated-type.stderr
+++ b/src/test/ui/issues/issue-43784-associated-type.stderr
@@ -2,9 +2,9 @@ error[E0277]: the trait bound `T: std::marker::Copy` is not satisfied
   --> $DIR/issue-43784-associated-type.rs:13:9
    |
 LL | impl<T> Complete for T {
-   |         ^^^^^^^^ the trait `std::marker::Copy` is not implemented for `T`
-   |
-   = help: consider adding a `where T: std::marker::Copy` bound
+   |      -  ^^^^^^^^ the trait `std::marker::Copy` is not implemented for `T`
+   |      |
+   |      help: consider restricting this bound: `T: std::marker::Copy`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/issues/issue-43784-supertrait.stderr b/src/test/ui/issues/issue-43784-supertrait.stderr
index 4c423f2e77f..5ac32041bce 100644
--- a/src/test/ui/issues/issue-43784-supertrait.stderr
+++ b/src/test/ui/issues/issue-43784-supertrait.stderr
@@ -2,9 +2,9 @@ error[E0277]: the trait bound `T: std::marker::Copy` is not satisfied
   --> $DIR/issue-43784-supertrait.rs:8:9
    |
 LL | impl<T> Complete for T {}
-   |         ^^^^^^^^ the trait `std::marker::Copy` is not implemented for `T`
-   |
-   = help: consider adding a `where T: std::marker::Copy` bound
+   |      -  ^^^^^^^^ the trait `std::marker::Copy` is not implemented for `T`
+   |      |
+   |      help: consider restricting this bound: `T: std::marker::Copy`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/specialization/defaultimpl/specialization-wfcheck.stderr b/src/test/ui/specialization/defaultimpl/specialization-wfcheck.stderr
index 45951561e72..5275b7b1ddf 100644
--- a/src/test/ui/specialization/defaultimpl/specialization-wfcheck.stderr
+++ b/src/test/ui/specialization/defaultimpl/specialization-wfcheck.stderr
@@ -2,9 +2,9 @@ error[E0277]: the trait bound `U: std::cmp::Eq` is not satisfied
   --> $DIR/specialization-wfcheck.rs:7:17
    |
 LL | default impl<U> Foo<'static, U> for () {}
-   |                 ^^^^^^^^^^^^^^^ the trait `std::cmp::Eq` is not implemented for `U`
-   |
-   = help: consider adding a `where U: std::cmp::Eq` bound
+   |              -  ^^^^^^^^^^^^^^^ the trait `std::cmp::Eq` is not implemented for `U`
+   |              |
+   |              help: consider restricting this bound: `U: std::cmp::Eq`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/traits/trait-bounds-on-structs-and-enums.stderr b/src/test/ui/traits/trait-bounds-on-structs-and-enums.stderr
index bd76df8071a..96bbd1f3e4f 100644
--- a/src/test/ui/traits/trait-bounds-on-structs-and-enums.stderr
+++ b/src/test/ui/traits/trait-bounds-on-structs-and-enums.stderr
@@ -5,9 +5,9 @@ LL | struct Foo<T:Trait> {
    | ------------------- required by `Foo`
 ...
 LL | impl<T> Foo<T> {
-   |         ^^^^^^ the trait `Trait` is not implemented for `T`
-   |
-   = help: consider adding a `where T: Trait` bound
+   |      -  ^^^^^^ the trait `Trait` is not implemented for `T`
+   |      |
+   |      help: consider restricting this bound: `T: Trait`
 
 error[E0277]: the trait bound `isize: Trait` is not satisfied
   --> $DIR/trait-bounds-on-structs-and-enums.rs:19:5
@@ -33,10 +33,10 @@ error[E0277]: the trait bound `U: Trait` is not satisfied
 LL | struct Foo<T:Trait> {
    | ------------------- required by `Foo`
 ...
+LL | struct Badness<U> {
+   |                - help: consider restricting this bound: `U: Trait`
 LL |     b: Foo<U>,
    |     ^^^^^^^^^ the trait `Trait` is not implemented for `U`
-   |
-   = help: consider adding a `where U: Trait` bound
 
 error[E0277]: the trait bound `V: Trait` is not satisfied
   --> $DIR/trait-bounds-on-structs-and-enums.rs:31:21
@@ -44,10 +44,10 @@ error[E0277]: the trait bound `V: Trait` is not satisfied
 LL | enum Bar<T:Trait> {
    | ----------------- required by `Bar`
 ...
+LL | enum MoreBadness<V> {
+   |                  - help: consider restricting this bound: `V: Trait`
 LL |     EvenMoreBadness(Bar<V>),
    |                     ^^^^^^ the trait `Trait` is not implemented for `V`
-   |
-   = help: consider adding a `where V: Trait` bound
 
 error[E0277]: the trait bound `i32: Trait` is not satisfied
   --> $DIR/trait-bounds-on-structs-and-enums.rs:35:5
diff --git a/src/test/ui/type/type-check-defaults.stderr b/src/test/ui/type/type-check-defaults.stderr
index 742a709958f..6802bc38b89 100644
--- a/src/test/ui/type/type-check-defaults.stderr
+++ b/src/test/ui/type/type-check-defaults.stderr
@@ -52,9 +52,10 @@ error[E0277]: the trait bound `T: std::marker::Copy` is not satisfied
 LL | trait Super<T: Copy> { }
    | -------------------- required by `Super`
 LL | trait Base<T = String>: Super<T> { }
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `std::marker::Copy` is not implemented for `T`
-   |
-   = help: consider adding a `where T: std::marker::Copy` bound
+   | ^^^^^^^^^^^-^^^^^^^^^^^^^^^^^^^^^^^^
+   | |          |
+   | |          help: consider restricting this bound: `T: std::marker::Copy`
+   | the trait `std::marker::Copy` is not implemented for `T`
 
 error[E0277]: cannot add `u8` to `i32`
   --> $DIR/type-check-defaults.rs:24:66
diff --git a/src/test/ui/union/union-sized-field.stderr b/src/test/ui/union/union-sized-field.stderr
index 89140030683..c9fec1d21d1 100644
--- a/src/test/ui/union/union-sized-field.stderr
+++ b/src/test/ui/union/union-sized-field.stderr
@@ -1,34 +1,37 @@
 error[E0277]: the size for values of type `T` cannot be known at compilation time
   --> $DIR/union-sized-field.rs:4:5
    |
+LL | union Foo<T: ?Sized> {
+   |           -- help: consider further restricting this bound: `T: std::marker::Sized +`
 LL |     value: T,
    |     ^^^^^^^^ doesn't have a size known at compile-time
    |
    = help: the trait `std::marker::Sized` is not implemented for `T`
    = note: to learn more, visit <https://doc.rust-lang.org/book/ch19-04-advanced-types.html#dynamically-sized-types-and-the-sized-trait>
-   = help: consider adding a `where T: std::marker::Sized` bound
    = note: no field of a union may have a dynamically sized type
 
 error[E0277]: the size for values of type `T` cannot be known at compilation time
   --> $DIR/union-sized-field.rs:9:5
    |
+LL | struct Foo2<T: ?Sized> {
+   |             -- help: consider further restricting this bound: `T: std::marker::Sized +`
 LL |     value: T,
    |     ^^^^^^^^ doesn't have a size known at compile-time
    |
    = help: the trait `std::marker::Sized` is not implemented for `T`
    = note: to learn more, visit <https://doc.rust-lang.org/book/ch19-04-advanced-types.html#dynamically-sized-types-and-the-sized-trait>
-   = help: consider adding a `where T: std::marker::Sized` bound
    = note: only the last field of a struct may have a dynamically sized type
 
 error[E0277]: the size for values of type `T` cannot be known at compilation time
   --> $DIR/union-sized-field.rs:15:11
    |
+LL | enum Foo3<T: ?Sized> {
+   |           -- help: consider further restricting this bound: `T: std::marker::Sized +`
 LL |     Value(T),
    |           ^ doesn't have a size known at compile-time
    |
    = help: the trait `std::marker::Sized` is not implemented for `T`
    = note: to learn more, visit <https://doc.rust-lang.org/book/ch19-04-advanced-types.html#dynamically-sized-types-and-the-sized-trait>
-   = help: consider adding a `where T: std::marker::Sized` bound
    = note: no field of an enum variant may have a dynamically sized type
 
 error: aborting due to 3 previous errors
diff --git a/src/test/ui/unsized/unsized-enum2.stderr b/src/test/ui/unsized/unsized-enum2.stderr
index cdd5747d86b..e85b6d662f9 100644
--- a/src/test/ui/unsized/unsized-enum2.stderr
+++ b/src/test/ui/unsized/unsized-enum2.stderr
@@ -1,45 +1,53 @@
 error[E0277]: the size for values of type `W` cannot be known at compilation time
   --> $DIR/unsized-enum2.rs:23:8
    |
+LL | enum E<W: ?Sized, X: ?Sized, Y: ?Sized, Z: ?Sized> {
+   |        -- help: consider further restricting this bound: `W: std::marker::Sized +`
+LL |     // parameter
 LL |     VA(W),
    |        ^ doesn't have a size known at compile-time
    |
    = help: the trait `std::marker::Sized` is not implemented for `W`
    = note: to learn more, visit <https://doc.rust-lang.org/book/ch19-04-advanced-types.html#dynamically-sized-types-and-the-sized-trait>
-   = help: consider adding a `where W: std::marker::Sized` bound
    = note: no field of an enum variant may have a dynamically sized type
 
 error[E0277]: the size for values of type `X` cannot be known at compilation time
   --> $DIR/unsized-enum2.rs:25:8
    |
+LL | enum E<W: ?Sized, X: ?Sized, Y: ?Sized, Z: ?Sized> {
+   |                   -- help: consider further restricting this bound: `X: std::marker::Sized +`
+...
 LL |     VB{x: X},
    |        ^^^^ doesn't have a size known at compile-time
    |
    = help: the trait `std::marker::Sized` is not implemented for `X`
    = note: to learn more, visit <https://doc.rust-lang.org/book/ch19-04-advanced-types.html#dynamically-sized-types-and-the-sized-trait>
-   = help: consider adding a `where X: std::marker::Sized` bound
    = note: no field of an enum variant may have a dynamically sized type
 
 error[E0277]: the size for values of type `Y` cannot be known at compilation time
   --> $DIR/unsized-enum2.rs:27:15
    |
+LL | enum E<W: ?Sized, X: ?Sized, Y: ?Sized, Z: ?Sized> {
+   |                              -- help: consider further restricting this bound: `Y: std::marker::Sized +`
+...
 LL |     VC(isize, Y),
    |               ^ doesn't have a size known at compile-time
    |
    = help: the trait `std::marker::Sized` is not implemented for `Y`
    = note: to learn more, visit <https://doc.rust-lang.org/book/ch19-04-advanced-types.html#dynamically-sized-types-and-the-sized-trait>
-   = help: consider adding a `where Y: std::marker::Sized` bound
    = note: no field of an enum variant may have a dynamically sized type
 
 error[E0277]: the size for values of type `Z` cannot be known at compilation time
   --> $DIR/unsized-enum2.rs:29:18
    |
+LL | enum E<W: ?Sized, X: ?Sized, Y: ?Sized, Z: ?Sized> {
+   |                                         -- help: consider further restricting this bound: `Z: std::marker::Sized +`
+...
 LL |     VD{u: isize, x: Z},
    |                  ^^^^ doesn't have a size known at compile-time
    |
    = help: the trait `std::marker::Sized` is not implemented for `Z`
    = note: to learn more, visit <https://doc.rust-lang.org/book/ch19-04-advanced-types.html#dynamically-sized-types-and-the-sized-trait>
-   = help: consider adding a `where Z: std::marker::Sized` bound
    = note: no field of an enum variant may have a dynamically sized type
 
 error[E0277]: the size for values of type `[u8]` cannot be known at compilation time
diff --git a/src/test/ui/unsized/unsized-inherent-impl-self-type.stderr b/src/test/ui/unsized/unsized-inherent-impl-self-type.stderr
index 1a726bb089f..280b8fd43ca 100644
--- a/src/test/ui/unsized/unsized-inherent-impl-self-type.stderr
+++ b/src/test/ui/unsized/unsized-inherent-impl-self-type.stderr
@@ -5,11 +5,12 @@ LL | struct S5<Y>(Y);
    | ---------------- required by `S5`
 LL | 
 LL | impl<X: ?Sized> S5<X> {
-   |                 ^^^^^ doesn't have a size known at compile-time
+   |      --         ^^^^^ doesn't have a size known at compile-time
+   |      |
+   |      help: consider further restricting this bound: `X: std::marker::Sized +`
    |
    = help: the trait `std::marker::Sized` is not implemented for `X`
    = note: to learn more, visit <https://doc.rust-lang.org/book/ch19-04-advanced-types.html#dynamically-sized-types-and-the-sized-trait>
-   = help: consider adding a `where X: std::marker::Sized` bound
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/unsized/unsized-trait-impl-self-type.stderr b/src/test/ui/unsized/unsized-trait-impl-self-type.stderr
index f399f8ded10..ba1550439c0 100644
--- a/src/test/ui/unsized/unsized-trait-impl-self-type.stderr
+++ b/src/test/ui/unsized/unsized-trait-impl-self-type.stderr
@@ -5,11 +5,12 @@ LL | struct S5<Y>(Y);
    | ---------------- required by `S5`
 LL | 
 LL | impl<X: ?Sized> T3<X> for S5<X> {
-   |                 ^^^^^ doesn't have a size known at compile-time
+   |      --         ^^^^^ doesn't have a size known at compile-time
+   |      |
+   |      help: consider further restricting this bound: `X: std::marker::Sized +`
    |
    = help: the trait `std::marker::Sized` is not implemented for `X`
    = note: to learn more, visit <https://doc.rust-lang.org/book/ch19-04-advanced-types.html#dynamically-sized-types-and-the-sized-trait>
-   = help: consider adding a `where X: std::marker::Sized` bound
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/unsized/unsized-trait-impl-trait-arg.stderr b/src/test/ui/unsized/unsized-trait-impl-trait-arg.stderr
index ee0d5ccccfe..41371d63f9e 100644
--- a/src/test/ui/unsized/unsized-trait-impl-trait-arg.stderr
+++ b/src/test/ui/unsized/unsized-trait-impl-trait-arg.stderr
@@ -2,11 +2,12 @@ error[E0277]: the size for values of type `X` cannot be known at compilation tim
   --> $DIR/unsized-trait-impl-trait-arg.rs:8:17
    |
 LL | impl<X: ?Sized> T2<X> for S4<X> {
-   |                 ^^^^^ doesn't have a size known at compile-time
+   |      --         ^^^^^ doesn't have a size known at compile-time
+   |      |
+   |      help: consider further restricting this bound: `X: std::marker::Sized +`
    |
    = help: the trait `std::marker::Sized` is not implemented for `X`
    = note: to learn more, visit <https://doc.rust-lang.org/book/ch19-04-advanced-types.html#dynamically-sized-types-and-the-sized-trait>
-   = help: consider adding a `where X: std::marker::Sized` bound
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/unsized5.stderr b/src/test/ui/unsized5.stderr
index 6dce9a04606..bfd3f4aa691 100644
--- a/src/test/ui/unsized5.stderr
+++ b/src/test/ui/unsized5.stderr
@@ -1,23 +1,26 @@
 error[E0277]: the size for values of type `X` cannot be known at compilation time
   --> $DIR/unsized5.rs:4:5
    |
+LL | struct S1<X: ?Sized> {
+   |           -- help: consider further restricting this bound: `X: std::marker::Sized +`
 LL |     f1: X,
    |     ^^^^^ doesn't have a size known at compile-time
    |
    = help: the trait `std::marker::Sized` is not implemented for `X`
    = note: to learn more, visit <https://doc.rust-lang.org/book/ch19-04-advanced-types.html#dynamically-sized-types-and-the-sized-trait>
-   = help: consider adding a `where X: std::marker::Sized` bound
    = note: only the last field of a struct may have a dynamically sized type
 
 error[E0277]: the size for values of type `X` cannot be known at compilation time
   --> $DIR/unsized5.rs:10:5
    |
+LL | struct S2<X: ?Sized> {
+   |           -- help: consider further restricting this bound: `X: std::marker::Sized +`
+LL |     f: isize,
 LL |     g: X,
    |     ^^^^ doesn't have a size known at compile-time
    |
    = help: the trait `std::marker::Sized` is not implemented for `X`
    = note: to learn more, visit <https://doc.rust-lang.org/book/ch19-04-advanced-types.html#dynamically-sized-types-and-the-sized-trait>
-   = help: consider adding a `where X: std::marker::Sized` bound
    = note: only the last field of a struct may have a dynamically sized type
 
 error[E0277]: the size for values of type `str` cannot be known at compilation time
@@ -43,23 +46,25 @@ LL |     f: [u8],
 error[E0277]: the size for values of type `X` cannot be known at compilation time
   --> $DIR/unsized5.rs:25:8
    |
+LL | enum E<X: ?Sized> {
+   |        -- help: consider further restricting this bound: `X: std::marker::Sized +`
 LL |     V1(X, isize),
    |        ^ doesn't have a size known at compile-time
    |
    = help: the trait `std::marker::Sized` is not implemented for `X`
    = note: to learn more, visit <https://doc.rust-lang.org/book/ch19-04-advanced-types.html#dynamically-sized-types-and-the-sized-trait>
-   = help: consider adding a `where X: std::marker::Sized` bound
    = note: no field of an enum variant may have a dynamically sized type
 
 error[E0277]: the size for values of type `X` cannot be known at compilation time
   --> $DIR/unsized5.rs:29:8
    |
+LL | enum F<X: ?Sized> {
+   |        -- help: consider further restricting this bound: `X: std::marker::Sized +`
 LL |     V2{f1: X, f: isize},
    |        ^^^^^ doesn't have a size known at compile-time
    |
    = help: the trait `std::marker::Sized` is not implemented for `X`
    = note: to learn more, visit <https://doc.rust-lang.org/book/ch19-04-advanced-types.html#dynamically-sized-types-and-the-sized-trait>
-   = help: consider adding a `where X: std::marker::Sized` bound
    = note: no field of an enum variant may have a dynamically sized type
 
 error: aborting due to 6 previous errors
diff --git a/src/test/ui/unsized7.stderr b/src/test/ui/unsized7.stderr
index bb83b181184..c77503a6f87 100644
--- a/src/test/ui/unsized7.stderr
+++ b/src/test/ui/unsized7.stderr
@@ -2,11 +2,12 @@ error[E0277]: the size for values of type `X` cannot be known at compilation tim
   --> $DIR/unsized7.rs:12:21
    |
 LL | impl<X: ?Sized + T> T1<X> for S3<X> {
-   |                     ^^^^^ doesn't have a size known at compile-time
+   |      --             ^^^^^ doesn't have a size known at compile-time
+   |      |
+   |      help: consider further restricting this bound: `X: std::marker::Sized +`
    |
    = help: the trait `std::marker::Sized` is not implemented for `X`
    = note: to learn more, visit <https://doc.rust-lang.org/book/ch19-04-advanced-types.html#dynamically-sized-types-and-the-sized-trait>
-   = help: consider adding a `where X: std::marker::Sized` bound
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/wf/wf-enum-bound.stderr b/src/test/ui/wf/wf-enum-bound.stderr
index d5632f4a9c2..eaacd6b6881 100644
--- a/src/test/ui/wf/wf-enum-bound.stderr
+++ b/src/test/ui/wf/wf-enum-bound.stderr
@@ -6,12 +6,11 @@ LL |   trait ExtraCopy<T:Copy> { }
 LL | 
 LL | / enum SomeEnum<T,U>
 LL | |     where T: ExtraCopy<U>
+   | |                          - help: consider further restricting type parameter `U`: `, U: std::marker::Copy`
 LL | | {
 LL | |     SomeVariant(T,U)
 LL | | }
    | |_^ the trait `std::marker::Copy` is not implemented for `U`
-   |
-   = help: consider adding a `where U: std::marker::Copy` bound
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/wf/wf-enum-fields-struct-variant.stderr b/src/test/ui/wf/wf-enum-fields-struct-variant.stderr
index 51ee23fc5aa..52882c460d2 100644
--- a/src/test/ui/wf/wf-enum-fields-struct-variant.stderr
+++ b/src/test/ui/wf/wf-enum-fields-struct-variant.stderr
@@ -4,10 +4,11 @@ error[E0277]: the trait bound `A: std::marker::Copy` is not satisfied
 LL | struct IsCopy<T:Copy> {
    | --------------------- required by `IsCopy`
 ...
+LL | enum AnotherEnum<A> {
+   |                  - help: consider restricting this bound: `A: std::marker::Copy`
+LL |     AnotherVariant {
 LL |         f: IsCopy<A>
    |         ^^^^^^^^^^^^ the trait `std::marker::Copy` is not implemented for `A`
-   |
-   = help: consider adding a `where A: std::marker::Copy` bound
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/wf/wf-enum-fields.stderr b/src/test/ui/wf/wf-enum-fields.stderr
index 5f4e7c66f54..0fea35d68ea 100644
--- a/src/test/ui/wf/wf-enum-fields.stderr
+++ b/src/test/ui/wf/wf-enum-fields.stderr
@@ -4,10 +4,10 @@ error[E0277]: the trait bound `A: std::marker::Copy` is not satisfied
 LL | struct IsCopy<T:Copy> {
    | --------------------- required by `IsCopy`
 ...
+LL | enum SomeEnum<A> {
+   |               - help: consider restricting this bound: `A: std::marker::Copy`
 LL |     SomeVariant(IsCopy<A>)
    |                 ^^^^^^^^^ the trait `std::marker::Copy` is not implemented for `A`
-   |
-   = help: consider adding a `where A: std::marker::Copy` bound
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/wf/wf-fn-where-clause.stderr b/src/test/ui/wf/wf-fn-where-clause.stderr
index 4bc2e370f29..9b8b04a7b86 100644
--- a/src/test/ui/wf/wf-fn-where-clause.stderr
+++ b/src/test/ui/wf/wf-fn-where-clause.stderr
@@ -4,12 +4,13 @@ error[E0277]: the trait bound `U: std::marker::Copy` is not satisfied
 LL |   trait ExtraCopy<T:Copy> { }
    |   ----------------------- required by `ExtraCopy`
 LL | 
-LL | / fn foo<T,U>() where T: ExtraCopy<U>
+LL |   fn foo<T,U>() where T: ExtraCopy<U>
+   |   ^                                  - help: consider further restricting type parameter `U`: `, U: std::marker::Copy`
+   |  _|
+   | |
 LL | | {
 LL | | }
    | |_^ the trait `std::marker::Copy` is not implemented for `U`
-   |
-   = help: consider adding a `where U: std::marker::Copy` bound
 
 error[E0277]: the size for values of type `(dyn std::marker::Copy + 'static)` cannot be known at compilation time
   --> $DIR/wf-fn-where-clause.rs:12:1
diff --git a/src/test/ui/wf/wf-in-fn-arg.stderr b/src/test/ui/wf/wf-in-fn-arg.stderr
index e7432f81987..3798ba1ec6e 100644
--- a/src/test/ui/wf/wf-in-fn-arg.stderr
+++ b/src/test/ui/wf/wf-in-fn-arg.stderr
@@ -4,12 +4,13 @@ error[E0277]: the trait bound `T: std::marker::Copy` is not satisfied
 LL |   struct MustBeCopy<T:Copy> {
    |   ------------------------- required by `MustBeCopy`
 ...
-LL | / fn bar<T>(_: &MustBeCopy<T>)
+LL |   fn bar<T>(_: &MustBeCopy<T>)
+   |   ^      - help: consider restricting this bound: `T: std::marker::Copy`
+   |  _|
+   | |
 LL | | {
 LL | | }
    | |_^ the trait `std::marker::Copy` is not implemented for `T`
-   |
-   = help: consider adding a `where T: std::marker::Copy` bound
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/wf/wf-in-fn-ret.stderr b/src/test/ui/wf/wf-in-fn-ret.stderr
index 005ffe84502..2e46ce49000 100644
--- a/src/test/ui/wf/wf-in-fn-ret.stderr
+++ b/src/test/ui/wf/wf-in-fn-ret.stderr
@@ -4,12 +4,13 @@ error[E0277]: the trait bound `T: std::marker::Copy` is not satisfied
 LL |   struct MustBeCopy<T:Copy> {
    |   ------------------------- required by `MustBeCopy`
 ...
-LL | / fn bar<T>() -> MustBeCopy<T>
+LL |   fn bar<T>() -> MustBeCopy<T>
+   |   ^      - help: consider restricting this bound: `T: std::marker::Copy`
+   |  _|
+   | |
 LL | | {
 LL | | }
    | |_^ the trait `std::marker::Copy` is not implemented for `T`
-   |
-   = help: consider adding a `where T: std::marker::Copy` bound
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/wf/wf-in-fn-type-arg.stderr b/src/test/ui/wf/wf-in-fn-type-arg.stderr
index b4cd9210402..db4fb9f97f5 100644
--- a/src/test/ui/wf/wf-in-fn-type-arg.stderr
+++ b/src/test/ui/wf/wf-in-fn-type-arg.stderr
@@ -4,10 +4,11 @@ error[E0277]: the trait bound `T: std::marker::Copy` is not satisfied
 LL | struct MustBeCopy<T:Copy> {
    | ------------------------- required by `MustBeCopy`
 ...
+LL | struct Bar<T> {
+   |            - help: consider restricting this bound: `T: std::marker::Copy`
+LL |     // needs T: Copy
 LL |     x: fn(MustBeCopy<T>)
    |     ^^^^^^^^^^^^^^^^^^^^ the trait `std::marker::Copy` is not implemented for `T`
-   |
-   = help: consider adding a `where T: std::marker::Copy` bound
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/wf/wf-in-fn-type-ret.stderr b/src/test/ui/wf/wf-in-fn-type-ret.stderr
index 988fbed8e91..09f8aa2a201 100644
--- a/src/test/ui/wf/wf-in-fn-type-ret.stderr
+++ b/src/test/ui/wf/wf-in-fn-type-ret.stderr
@@ -4,10 +4,11 @@ error[E0277]: the trait bound `T: std::marker::Copy` is not satisfied
 LL | struct MustBeCopy<T:Copy> {
    | ------------------------- required by `MustBeCopy`
 ...
+LL | struct Foo<T> {
+   |            - help: consider restricting this bound: `T: std::marker::Copy`
+LL |     // needs T: 'static
 LL |     x: fn() -> MustBeCopy<T>
    |     ^^^^^^^^^^^^^^^^^^^^^^^^ the trait `std::marker::Copy` is not implemented for `T`
-   |
-   = help: consider adding a `where T: std::marker::Copy` bound
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/wf/wf-in-fn-where-clause.stderr b/src/test/ui/wf/wf-in-fn-where-clause.stderr
index 0af38ddcffe..979802dec49 100644
--- a/src/test/ui/wf/wf-in-fn-where-clause.stderr
+++ b/src/test/ui/wf/wf-in-fn-where-clause.stderr
@@ -6,11 +6,10 @@ LL |   trait MustBeCopy<T:Copy> {
 ...
 LL | / fn bar<T,U>()
 LL | |     where T: MustBeCopy<U>
+   | |                           - help: consider further restricting type parameter `U`: `, U: std::marker::Copy`
 LL | | {
 LL | | }
    | |_^ the trait `std::marker::Copy` is not implemented for `U`
-   |
-   = help: consider adding a `where U: std::marker::Copy` bound
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/wf/wf-in-obj-type-trait.stderr b/src/test/ui/wf/wf-in-obj-type-trait.stderr
index 0f4b4e417ca..2711820d82c 100644
--- a/src/test/ui/wf/wf-in-obj-type-trait.stderr
+++ b/src/test/ui/wf/wf-in-obj-type-trait.stderr
@@ -4,10 +4,11 @@ error[E0277]: the trait bound `T: std::marker::Copy` is not satisfied
 LL | struct MustBeCopy<T:Copy> {
    | ------------------------- required by `MustBeCopy`
 ...
+LL | struct Bar<T> {
+   |            - help: consider restricting this bound: `T: std::marker::Copy`
+LL |     // needs T: Copy
 LL |     x: dyn Object<MustBeCopy<T>>
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `std::marker::Copy` is not implemented for `T`
-   |
-   = help: consider adding a `where T: std::marker::Copy` bound
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/wf/wf-inherent-impl-where-clause.stderr b/src/test/ui/wf/wf-inherent-impl-where-clause.stderr
index 4c389b3ef3e..35b90933813 100644
--- a/src/test/ui/wf/wf-inherent-impl-where-clause.stderr
+++ b/src/test/ui/wf/wf-inherent-impl-where-clause.stderr
@@ -4,12 +4,13 @@ error[E0277]: the trait bound `U: std::marker::Copy` is not satisfied
 LL |   trait ExtraCopy<T:Copy> { }
    |   ----------------------- required by `ExtraCopy`
 ...
-LL | / impl<T,U> Foo<T,U> where T: ExtraCopy<U>
+LL |   impl<T,U> Foo<T,U> where T: ExtraCopy<U>
+   |   ^                                       - help: consider further restricting type parameter `U`: `, U: std::marker::Copy`
+   |  _|
+   | |
 LL | | {
 LL | | }
    | |_^ the trait `std::marker::Copy` is not implemented for `U`
-   |
-   = help: consider adding a `where U: std::marker::Copy` bound
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/wf/wf-struct-bound.stderr b/src/test/ui/wf/wf-struct-bound.stderr
index 2028a0baa17..21559773492 100644
--- a/src/test/ui/wf/wf-struct-bound.stderr
+++ b/src/test/ui/wf/wf-struct-bound.stderr
@@ -6,12 +6,11 @@ LL |   trait ExtraCopy<T:Copy> { }
 LL | 
 LL | / struct SomeStruct<T,U>
 LL | |     where T: ExtraCopy<U>
+   | |                          - help: consider further restricting type parameter `U`: `, U: std::marker::Copy`
 LL | | {
 LL | |     data: (T,U)
 LL | | }
    | |_^ the trait `std::marker::Copy` is not implemented for `U`
-   |
-   = help: consider adding a `where U: std::marker::Copy` bound
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/wf/wf-struct-field.stderr b/src/test/ui/wf/wf-struct-field.stderr
index d2bff253678..6ac4f1e2da8 100644
--- a/src/test/ui/wf/wf-struct-field.stderr
+++ b/src/test/ui/wf/wf-struct-field.stderr
@@ -4,10 +4,10 @@ error[E0277]: the trait bound `A: std::marker::Copy` is not satisfied
 LL | struct IsCopy<T:Copy> {
    | --------------------- required by `IsCopy`
 ...
+LL | struct SomeStruct<A> {
+   |                   - help: consider restricting this bound: `A: std::marker::Copy`
 LL |     data: IsCopy<A>
    |     ^^^^^^^^^^^^^^^ the trait `std::marker::Copy` is not implemented for `A`
-   |
-   = help: consider adding a `where A: std::marker::Copy` bound
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/wf/wf-trait-associated-type-bound.stderr b/src/test/ui/wf/wf-trait-associated-type-bound.stderr
index d5b2b5762a4..af0433fd22f 100644
--- a/src/test/ui/wf/wf-trait-associated-type-bound.stderr
+++ b/src/test/ui/wf/wf-trait-associated-type-bound.stderr
@@ -4,12 +4,13 @@ error[E0277]: the trait bound `T: std::marker::Copy` is not satisfied
 LL |   trait ExtraCopy<T:Copy> { }
    |   ----------------------- required by `ExtraCopy`
 LL | 
-LL | / trait SomeTrait<T> {
+LL |   trait SomeTrait<T> {
+   |   ^               - help: consider restricting this bound: `T: std::marker::Copy`
+   |  _|
+   | |
 LL | |     type Type1: ExtraCopy<T>;
 LL | | }
    | |_^ the trait `std::marker::Copy` is not implemented for `T`
-   |
-   = help: consider adding a `where T: std::marker::Copy` bound
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/wf/wf-trait-bound.stderr b/src/test/ui/wf/wf-trait-bound.stderr
index 85f12b2de54..13e2f8f5901 100644
--- a/src/test/ui/wf/wf-trait-bound.stderr
+++ b/src/test/ui/wf/wf-trait-bound.stderr
@@ -6,11 +6,10 @@ LL |   trait ExtraCopy<T:Copy> { }
 LL | 
 LL | / trait SomeTrait<T,U>
 LL | |     where T: ExtraCopy<U>
+   | |                          - help: consider further restricting type parameter `U`: `, U: std::marker::Copy`
 LL | | {
 LL | | }
    | |_^ the trait `std::marker::Copy` is not implemented for `U`
-   |
-   = help: consider adding a `where U: std::marker::Copy` bound
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/wf/wf-trait-superbound.stderr b/src/test/ui/wf/wf-trait-superbound.stderr
index 377ca640536..a61b8dd3a38 100644
--- a/src/test/ui/wf/wf-trait-superbound.stderr
+++ b/src/test/ui/wf/wf-trait-superbound.stderr
@@ -4,11 +4,12 @@ error[E0277]: the trait bound `T: std::marker::Copy` is not satisfied
 LL |   trait ExtraCopy<T:Copy> { }
    |   ----------------------- required by `ExtraCopy`
 LL | 
-LL | / trait SomeTrait<T>: ExtraCopy<T> {
+LL |   trait SomeTrait<T>: ExtraCopy<T> {
+   |   ^               - help: consider restricting this bound: `T: std::marker::Copy`
+   |  _|
+   | |
 LL | | }
    | |_^ the trait `std::marker::Copy` is not implemented for `T`
-   |
-   = help: consider adding a `where T: std::marker::Copy` bound
 
 error: aborting due to previous error