Include a span in more expected...found notes

In most places, we use a span when emitting `expected...found` errors.
However, there were a couple of places where we didn't use any span,
resulting in hard-to-interpret error messages.

This commit attaches the relevant span to these notes, and additionally
switches over to using `note_expected_found` instead of manually
formatting the message

src/librustc/infer/error_reporting/mod.rs

@@ -1809,12 +1809,17 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
                             sub_region,
                             "...",
                         );
-                        err.note(&format!(
-                            "...so that the {}:\nexpected {}\n   found {}",
-                            sup_trace.cause.as_requirement_str(),
-                            sup_expected.content(),
-                            sup_found.content()
+                        err.span_note(sup_trace.cause.span, &format!(
+                            "...so that the {}",
+                            sup_trace.cause.as_requirement_str()
                         ));
+
+                        err.note_expected_found(
+                            &"",
+                            sup_expected,
+                            &"",
+                            sup_found
+                        );
                         err.emit();
                         return;
                     }

src/librustc/infer/error_reporting/note.rs

@@ -13,12 +13,20 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
         match *origin {
             infer::Subtype(ref trace) => {
                 if let Some((expected, found)) = self.values_str(&trace.values) {
-                    let expected = expected.content();
-                    let found = found.content();
-                    err.note(&format!("...so that the {}:\nexpected {}\n   found {}",
-                                      trace.cause.as_requirement_str(),
-                                      expected,
-                                      found));
+                    err.span_note(
+                        trace.cause.span,
+                        &format!(
+                            "...so that the {}",
+                            trace.cause.as_requirement_str()
+                        )
+                    );
+
+                    err.note_expected_found(
+                        &"",
+                        expected,
+                        &"",
+                        found
+                    );
                 } else {
                     // FIXME: this really should be handled at some earlier stage. Our
                     // handling of region checking when type errors are present is

src/test/ui/associated-types/cache/project-fn-ret-invariant.transmute.stderr

@@ -9,13 +9,21 @@ note: first, the lifetime cannot outlive the lifetime `'a` as defined on the fun
    |
 LL | fn baz<'a,'b>(x: Type<'a>) -> Type<'static> {
    |        ^^
-   = note: ...so that the expression is assignable:
-           expected Type<'_>
-              found Type<'a>
+note: ...so that the expression is assignable
+  --> $DIR/project-fn-ret-invariant.rs:48:13
+   |
+LL |    bar(foo, x)
+   |             ^
+   = note: expected  `Type<'_>`
+              found  `Type<'a>`
    = note: but, the lifetime must be valid for the static lifetime...
-   = note: ...so that the expression is assignable:
-           expected Type<'static>
-              found Type<'_>
+note: ...so that the expression is assignable
+  --> $DIR/project-fn-ret-invariant.rs:48:4
+   |
+LL |    bar(foo, x)
+   |    ^^^^^^^^^^^
+   = note: expected  `Type<'static>`
+              found  `Type<'_>`
 
 error: aborting due to previous error
 

src/test/ui/c-variadic/variadic-ffi-4.stderr

@@ -49,9 +49,13 @@ note: first, the lifetime cannot outlive the anonymous lifetime #2 defined on th
    |
 LL |     let _ = ap.with_copy(|ap| { ap });
    |                          ^^^^^^^^^^^
-   = note: ...so that the expression is assignable:
-           expected core::ffi::VaList<'_, '_>
-              found core::ffi::VaList<'_, '_>
+note: ...so that the expression is assignable
+  --> $DIR/variadic-ffi-4.rs:16:33
+   |
+LL |     let _ = ap.with_copy(|ap| { ap });
+   |                                 ^^
+   = note: expected  `core::ffi::VaList<'_, '_>`
+              found  `core::ffi::VaList<'_, '_>`
 note: but, the lifetime must be valid for the method call at 16:13...
   --> $DIR/variadic-ffi-4.rs:16:13
    |

src/test/ui/impl-header-lifetime-elision/dyn-trait.stderr

@@ -9,13 +9,21 @@ note: first, the lifetime cannot outlive the lifetime `'a` as defined on the fun
    |
 LL | fn with_dyn_debug_static<'a>(x: Box<dyn Debug + 'a>) {
    |                          ^^
-   = note: ...so that the expression is assignable:
-           expected std::boxed::Box<dyn std::fmt::Debug>
-              found std::boxed::Box<(dyn std::fmt::Debug + 'a)>
+note: ...so that the expression is assignable
+  --> $DIR/dyn-trait.rs:20:16
+   |
+LL |     static_val(x);
+   |                ^
+   = note: expected  `std::boxed::Box<dyn std::fmt::Debug>`
+              found  `std::boxed::Box<(dyn std::fmt::Debug + 'a)>`
    = note: but, the lifetime must be valid for the static lifetime...
-   = note: ...so that the types are compatible:
-           expected StaticTrait
-              found StaticTrait
+note: ...so that the types are compatible
+  --> $DIR/dyn-trait.rs:20:5
+   |
+LL |     static_val(x);
+   |     ^^^^^^^^^^
+   = note: expected  `StaticTrait`
+              found  `StaticTrait`
 
 error: aborting due to previous error
 

src/test/ui/issues/issue-16683.stderr

@@ -21,9 +21,13 @@ note: but, the lifetime must be valid for the lifetime `'a` as defined on the tr
    |
 LL | trait T<'a> {
    |         ^^
-   = note: ...so that the types are compatible:
-           expected &'a Self
-              found &Self
+note: ...so that the types are compatible
+  --> $DIR/issue-16683.rs:4:14
+   |
+LL |         self.a();
+   |              ^
+   = note: expected  `&'a Self`
+              found  `&Self`
 
 error: aborting due to previous error
 

src/test/ui/issues/issue-17758.stderr

@@ -22,9 +22,13 @@ note: but, the lifetime must be valid for the lifetime `'a` as defined on the tr
    |
 LL | trait Foo<'a> {
    |           ^^
-   = note: ...so that the types are compatible:
-           expected &'a Self
-              found &Self
+note: ...so that the types are compatible
+  --> $DIR/issue-17758.rs:7:14
+   |
+LL |         self.foo();
+   |              ^^^
+   = note: expected  `&'a Self`
+              found  `&Self`
 
 error: aborting due to previous error
 

src/test/ui/issues/issue-20831-debruijn.stderr

@@ -88,9 +88,19 @@ note: ...but the lifetime must also be valid for the lifetime `'a` as defined on
    |
 LL | impl<'a> Publisher<'a> for MyStruct<'a> {
    |      ^^
-   = note: ...so that the types are compatible:
-           expected Publisher<'_>
-              found Publisher<'_>
+note: ...so that the types are compatible
+  --> $DIR/issue-20831-debruijn.rs:28:5
+   |
+LL | /     fn subscribe(&mut self, t : Box<dyn Subscriber<Input=<Self as Publisher>::Output> + 'a>) {
+LL | |         // Not obvious, but there is an implicit lifetime here -------^
+LL | |
+LL | |
+...  |
+LL | |         self.sub = t;
+LL | |     }
+   | |_____^
+   = note: expected  `Publisher<'_>`
+              found  `Publisher<'_>`
 
 error: aborting due to 3 previous errors
 

src/test/ui/issues/issue-52213.stderr

@@ -9,9 +9,13 @@ note: first, the lifetime cannot outlive the lifetime `'a` as defined on the fun
    |
 LL | fn transmute_lifetime<'a, 'b, T>(t: &'a (T,)) -> &'b T {
    |                       ^^
-   = note: ...so that the types are compatible:
-           expected (&&(T,),)
-              found (&&'a (T,),)
+note: ...so that the types are compatible
+  --> $DIR/issue-52213.rs:2:11
+   |
+LL |     match (&t,) {
+   |           ^^^^^
+   = note: expected  `(&&(T,),)`
+              found  `(&&'a (T,),)`
 note: but, the lifetime must be valid for the lifetime `'b` as defined on the function body at 1:27...
   --> $DIR/issue-52213.rs:1:27
    |

src/test/ui/issues/issue-55796.stderr

@@ -15,9 +15,13 @@ note: ...so that the type `std::iter::Map<<Self as Graph<'a>>::EdgesIter, [closu
 LL |         Box::new(self.out_edges(u).map(|e| e.target()))
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    = note: but, the lifetime must be valid for the static lifetime...
-   = note: ...so that the expression is assignable:
-           expected std::boxed::Box<(dyn std::iter::Iterator<Item = <Self as Graph<'a>>::Node> + 'static)>
-              found std::boxed::Box<dyn std::iter::Iterator<Item = <Self as Graph<'a>>::Node>>
+note: ...so that the expression is assignable
+  --> $DIR/issue-55796.rs:16:9
+   |
+LL |         Box::new(self.out_edges(u).map(|e| e.target()))
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   = note: expected  `std::boxed::Box<(dyn std::iter::Iterator<Item = <Self as Graph<'a>>::Node> + 'static)>`
+              found  `std::boxed::Box<dyn std::iter::Iterator<Item = <Self as Graph<'a>>::Node>>`
 
 error[E0495]: cannot infer an appropriate lifetime due to conflicting requirements
   --> $DIR/issue-55796.rs:21:9
@@ -36,9 +40,13 @@ note: ...so that the type `std::iter::Map<<Self as Graph<'a>>::EdgesIter, [closu
 LL |         Box::new(self.in_edges(u).map(|e| e.target()))
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    = note: but, the lifetime must be valid for the static lifetime...
-   = note: ...so that the expression is assignable:
-           expected std::boxed::Box<(dyn std::iter::Iterator<Item = <Self as Graph<'a>>::Node> + 'static)>
-              found std::boxed::Box<dyn std::iter::Iterator<Item = <Self as Graph<'a>>::Node>>
+note: ...so that the expression is assignable
+  --> $DIR/issue-55796.rs:21:9
+   |
+LL |         Box::new(self.in_edges(u).map(|e| e.target()))
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   = note: expected  `std::boxed::Box<(dyn std::iter::Iterator<Item = <Self as Graph<'a>>::Node> + 'static)>`
+              found  `std::boxed::Box<dyn std::iter::Iterator<Item = <Self as Graph<'a>>::Node>>`
 
 error: aborting due to 2 previous errors
 

src/test/ui/nll/issue-55394.stderr

@@ -21,9 +21,13 @@ note: but, the lifetime must be valid for the lifetime `'_` as defined on the im
    |
 LL | impl Foo<'_> {
    |          ^^
-   = note: ...so that the expression is assignable:
-           expected Foo<'_>
-              found Foo<'_>
+note: ...so that the expression is assignable
+  --> $DIR/issue-55394.rs:9:9
+   |
+LL |         Foo { bar }
+   |         ^^^^^^^^^^^
+   = note: expected  `Foo<'_>`
+              found  `Foo<'_>`
 
 error: aborting due to previous error
 

src/test/ui/nll/normalization-bounds-error.stderr

@@ -14,9 +14,13 @@ note: ...but the lifetime must also be valid for the lifetime `'a` as defined on
    |
 LL | fn visit_seq<'d, 'a: 'd>() -> <&'a () as Visitor<'d>>::Value {}
    |                  ^^
-   = note: ...so that the types are compatible:
-           expected Visitor<'d>
-              found Visitor<'_>
+note: ...so that the types are compatible
+  --> $DIR/normalization-bounds-error.rs:12:1
+   |
+LL | fn visit_seq<'d, 'a: 'd>() -> <&'a () as Visitor<'d>>::Value {}
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   = note: expected  `Visitor<'d>`
+              found  `Visitor<'_>`
 
 error: aborting due to previous error
 

src/test/ui/nll/type-alias-free-regions.stderr

@@ -11,17 +11,25 @@ LL | /     fn from_box(b: Box<B>) -> Self {
 LL | |         C { f: b }
 LL | |     }
    | |_____^
-   = note: ...so that the expression is assignable:
-           expected std::boxed::Box<std::boxed::Box<&isize>>
-              found std::boxed::Box<std::boxed::Box<&isize>>
+note: ...so that the expression is assignable
+  --> $DIR/type-alias-free-regions.rs:17:16
+   |
+LL |         C { f: b }
+   |                ^
+   = note: expected  `std::boxed::Box<std::boxed::Box<&isize>>`
+              found  `std::boxed::Box<std::boxed::Box<&isize>>`
 note: but, the lifetime must be valid for the lifetime `'a` as defined on the impl at 15:6...
   --> $DIR/type-alias-free-regions.rs:15:6
    |
 LL | impl<'a> FromBox<'a> for C<'a> {
    |      ^^
-   = note: ...so that the expression is assignable:
-           expected C<'a>
-              found C<'_>
+note: ...so that the expression is assignable
+  --> $DIR/type-alias-free-regions.rs:17:9
+   |
+LL |         C { f: b }
+   |         ^^^^^^^^^^
+   = note: expected  `C<'a>`
+              found  `C<'_>`
 
 error[E0495]: cannot infer an appropriate lifetime due to conflicting requirements
   --> $DIR/type-alias-free-regions.rs:27:16
@@ -36,17 +44,25 @@ LL | /     fn from_tuple(b: (B,)) -> Self {
 LL | |         C { f: Box::new(b.0) }
 LL | |     }
    | |_____^
-   = note: ...so that the expression is assignable:
-           expected std::boxed::Box<&isize>
-              found std::boxed::Box<&isize>
+note: ...so that the expression is assignable
+  --> $DIR/type-alias-free-regions.rs:27:25
+   |
+LL |         C { f: Box::new(b.0) }
+   |                         ^^^
+   = note: expected  `std::boxed::Box<&isize>`
+              found  `std::boxed::Box<&isize>`
 note: but, the lifetime must be valid for the lifetime `'a` as defined on the impl at 25:6...
   --> $DIR/type-alias-free-regions.rs:25:6
    |
 LL | impl<'a> FromTuple<'a> for C<'a> {
    |      ^^
-   = note: ...so that the expression is assignable:
-           expected C<'a>
-              found C<'_>
+note: ...so that the expression is assignable
+  --> $DIR/type-alias-free-regions.rs:27:9
+   |
+LL |         C { f: Box::new(b.0) }
+   |         ^^^^^^^^^^^^^^^^^^^^^^
+   = note: expected  `C<'a>`
+              found  `C<'_>`
 
 error: aborting due to 2 previous errors
 

src/test/ui/nll/user-annotations/constant-in-expr-inherent-1.stderr

@@ -9,9 +9,13 @@ note: first, the lifetime cannot outlive the lifetime `'a` as defined on the fun
    |
 LL | fn foo<'a>(_: &'a u32) -> &'static u32 {
    |        ^^
-   = note: ...so that the types are compatible:
-           expected Foo<'_>
-              found Foo<'a>
+note: ...so that the types are compatible
+  --> $DIR/constant-in-expr-inherent-1.rs:8:5
+   |
+LL |     <Foo<'a>>::C
+   |     ^^^^^^^^^^^^
+   = note: expected  `Foo<'_>`
+              found  `Foo<'a>`
    = note: but, the lifetime must be valid for the static lifetime...
 note: ...so that reference does not outlive borrowed content
   --> $DIR/constant-in-expr-inherent-1.rs:8:5

src/test/ui/nll/user-annotations/constant-in-expr-trait-item-3.stderr

@@ -9,9 +9,13 @@ note: first, the lifetime cannot outlive the lifetime `'a` as defined on the fun
    |
 LL | fn foo<'a, T: Foo<'a>>() -> &'static u32 {
    |        ^^
-   = note: ...so that the types are compatible:
-           expected Foo<'_>
-              found Foo<'a>
+note: ...so that the types are compatible
+  --> $DIR/constant-in-expr-trait-item-3.rs:10:5
+   |
+LL |     T::C
+   |     ^^^^
+   = note: expected  `Foo<'_>`
+              found  `Foo<'a>`
    = note: but, the lifetime must be valid for the static lifetime...
 note: ...so that reference does not outlive borrowed content
   --> $DIR/constant-in-expr-trait-item-3.rs:10:5

src/test/ui/object-lifetime/object-lifetime-default-elision.stderr

@@ -19,9 +19,13 @@ note: but, the lifetime must be valid for the lifetime `'b` as defined on the fu
    |
 LL | fn load3<'a,'b>(ss: &'a dyn SomeTrait) -> &'b dyn SomeTrait {
    |             ^^
-   = note: ...so that the expression is assignable:
-           expected &'b (dyn SomeTrait + 'b)
-              found &dyn SomeTrait
+note: ...so that the expression is assignable
+  --> $DIR/object-lifetime-default-elision.rs:71:5
+   |
+LL |     ss
+   |     ^^
+   = note: expected  `&'b (dyn SomeTrait + 'b)`
+              found  `&dyn SomeTrait`
 
 error[E0495]: cannot infer an appropriate lifetime due to conflicting requirements
   --> $DIR/object-lifetime-default-elision.rs:71:5
@@ -44,9 +48,13 @@ note: but, the lifetime must be valid for the lifetime `'b` as defined on the fu
    |
 LL | fn load3<'a,'b>(ss: &'a dyn SomeTrait) -> &'b dyn SomeTrait {
    |             ^^
-   = note: ...so that the expression is assignable:
-           expected &'b (dyn SomeTrait + 'b)
-              found &dyn SomeTrait
+note: ...so that the expression is assignable
+  --> $DIR/object-lifetime-default-elision.rs:71:5
+   |
+LL |     ss
+   |     ^^
+   = note: expected  `&'b (dyn SomeTrait + 'b)`
+              found  `&dyn SomeTrait`
 
 error: aborting due to 2 previous errors