Handle more cases

Author: estebank

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();

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

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

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
 

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
 

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
 

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

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
 

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
 

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