Call out the types that are non local on E0117

Author: estebank

src/librustc/traits/coherence.rs

@@ -237,7 +237,7 @@ pub fn trait_ref_is_local_or_fundamental<'tcx>(
 }
 
 pub enum OrphanCheckErr<'tcx> {
-    NoLocalInputType,
+    NonLocalInputType(Vec<Ty<'tcx>>),
     UncoveredTy(Ty<'tcx>),
 }
 
@@ -390,6 +390,7 @@ fn orphan_check_trait_ref<'tcx>(
             }
         }
 
+        let mut non_local_spans = vec![];
         for input_ty in
             trait_ref.input_types().flat_map(|ty| uncover_fundamental_ty(tcx, ty, in_crate))
         {
@@ -401,11 +402,13 @@ fn orphan_check_trait_ref<'tcx>(
                 debug!("orphan_check_trait_ref: uncovered ty: `{:?}`", input_ty);
                 return Err(OrphanCheckErr::UncoveredTy(input_ty))
             }
+            non_local_spans.push(input_ty);
         }
         // If we exit above loop, never found a local type.
         debug!("orphan_check_trait_ref: no local type");
-        Err(OrphanCheckErr::NoLocalInputType)
+        Err(OrphanCheckErr::NonLocalInputType(non_local_spans))
     } else {
+        let mut non_local_spans = vec![];
         // First, create an ordered iterator over all the type
         // parameters to the trait, with the self type appearing
         // first.  Find the first input type that either references a
@@ -438,10 +441,12 @@ fn orphan_check_trait_ref<'tcx>(
                 debug!("orphan_check_trait_ref: uncovered type `{:?}`", param);
                 return Err(OrphanCheckErr::UncoveredTy(param));
             }
+
+            non_local_spans.push(input_ty);
         }
         // If we exit above loop, never found a local type.
         debug!("orphan_check_trait_ref: no local type");
-        Err(OrphanCheckErr::NoLocalInputType)
+        Err(OrphanCheckErr::NonLocalInputType(non_local_spans))
     }
 }
 

src/librustc_typeck/coherence/orphan.rs

@@ -33,16 +33,20 @@ impl ItemLikeVisitor<'v> for OrphanChecker<'tcx> {
             let sp = cm.def_span(item.span);
             match traits::orphan_check(self.tcx, def_id) {
                 Ok(()) => {}
-                Err(traits::OrphanCheckErr::NoLocalInputType) => {
-                    struct_span_err!(self.tcx.sess,
-                                     sp,
-                                     E0117,
-                                     "only traits defined in the current crate can be \
-                                      implemented for arbitrary types")
-                        .span_label(sp, "impl doesn't use types inside crate")
-                        .note("the impl does not reference only types defined in this crate")
-                        .note("define and implement a trait or new type instead")
-                        .emit();
+                Err(traits::OrphanCheckErr::NonLocalInputType(tys)) => {
+                    let mut err = struct_span_err!(
+                        self.tcx.sess,
+                        sp,
+                        E0117,
+                        "only traits defined in the current crate can be implemented for \
+                         arbitrary types"
+                    );
+                    err.span_label(sp, "impl doesn't use types inside crate");
+                    for ty in &tys {
+                        err.note(&format!("`{}` is not defined in the current create", ty));
+                    }
+                    err.note("define and implement a trait or new type instead");
+                    err.emit();
                     return;
                 }
                 Err(traits::OrphanCheckErr::UncoveredTy(param_ty)) => {

src/test/ui/coherence/coherence-cow.re_a.stderr

@@ -4,7 +4,7 @@ error[E0117]: only traits defined in the current crate can be implemented for ar
 LL | impl<T> Remote for Pair<T,Cover<T>> { }
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ impl doesn't use types inside crate
    |
-   = note: the impl does not reference only types defined in this crate
+   = note: `lib::Pair<T, Cover<T>>` is not defined in the current create
    = note: define and implement a trait or new type instead
 
 error: aborting due to previous error

src/test/ui/coherence/coherence-cow.re_b.stderr

@@ -4,7 +4,7 @@ error[E0117]: only traits defined in the current crate can be implemented for ar
 LL | impl<T> Remote for Pair<Cover<T>,T> { }
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ impl doesn't use types inside crate
    |
-   = note: the impl does not reference only types defined in this crate
+   = note: `lib::Pair<Cover<T>, T>` is not defined in the current create
    = note: define and implement a trait or new type instead
 
 error: aborting due to previous error

src/test/ui/coherence/coherence-cow.re_c.stderr

@@ -4,7 +4,7 @@ error[E0117]: only traits defined in the current crate can be implemented for ar
 LL | impl<T,U> Remote for Pair<Cover<T>,U> { }
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ impl doesn't use types inside crate
    |
-   = note: the impl does not reference only types defined in this crate
+   = note: `lib::Pair<Cover<T>, U>` is not defined in the current create
    = note: define and implement a trait or new type instead
 
 error: aborting due to previous error

src/test/ui/coherence/coherence-fundamental-trait-objects.old.stderr

@@ -4,7 +4,7 @@ error[E0117]: only traits defined in the current crate can be implemented for ar
 LL | impl Misc for dyn Fundamental<Local> {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ impl doesn't use types inside crate
    |
-   = note: the impl does not reference only types defined in this crate
+   = note: `(dyn coherence_fundamental_trait_lib::Fundamental<Local> + 'static)` is not defined in the current create
    = note: define and implement a trait or new type instead
 
 error: aborting due to previous error

src/test/ui/coherence/coherence-fundamental-trait-objects.re.stderr

@@ -4,7 +4,7 @@ error[E0117]: only traits defined in the current crate can be implemented for ar
 LL | impl Misc for dyn Fundamental<Local> {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ impl doesn't use types inside crate
    |
-   = note: the impl does not reference only types defined in this crate
+   = note: `(dyn coherence_fundamental_trait_lib::Fundamental<Local> + 'static)` is not defined in the current create
    = note: define and implement a trait or new type instead
 
 error: aborting due to previous error

src/test/ui/coherence/coherence-impl-trait-for-marker-trait-negative.stderr

@@ -16,7 +16,7 @@ error[E0117]: only traits defined in the current crate can be implemented for ar
 LL | impl !Send for dyn Marker2 {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^ impl doesn't use types inside crate
    |
-   = note: the impl does not reference only types defined in this crate
+   = note: `(dyn Marker2 + 'static)` is not defined in the current create
    = note: define and implement a trait or new type instead
 
 error[E0321]: cross-crate traits with a default impl, like `std::marker::Send`, can only be implemented for a struct/enum type, not `(dyn Object + 'static)`

src/test/ui/coherence/coherence-impl-trait-for-marker-trait-positive.stderr

@@ -16,7 +16,7 @@ error[E0117]: only traits defined in the current crate can be implemented for ar
 LL | unsafe impl Send for dyn Marker2 {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ impl doesn't use types inside crate
    |
-   = note: the impl does not reference only types defined in this crate
+   = note: `(dyn Marker2 + 'static)` is not defined in the current create
    = note: define and implement a trait or new type instead
 
 error[E0321]: cross-crate traits with a default impl, like `std::marker::Send`, can only be implemented for a struct/enum type, not `(dyn Object + 'static)`

src/test/ui/coherence/coherence-impls-copy.old.stderr

@@ -51,7 +51,7 @@ error[E0117]: only traits defined in the current crate can be implemented for ar
 LL | impl Copy for i32 {}
    | ^^^^^^^^^^^^^^^^^ impl doesn't use types inside crate
    |
-   = note: the impl does not reference only types defined in this crate
+   = note: `i32` is not defined in the current create
    = note: define and implement a trait or new type instead
 
 error[E0117]: only traits defined in the current crate can be implemented for arbitrary types
@@ -60,7 +60,7 @@ error[E0117]: only traits defined in the current crate can be implemented for ar
 LL | impl Copy for (MyType, MyType) {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ impl doesn't use types inside crate
    |
-   = note: the impl does not reference only types defined in this crate
+   = note: `(MyType, MyType)` is not defined in the current create
    = note: define and implement a trait or new type instead
 
 error[E0117]: only traits defined in the current crate can be implemented for arbitrary types
@@ -69,7 +69,7 @@ error[E0117]: only traits defined in the current crate can be implemented for ar
 LL | impl Copy for [MyType] {}
    | ^^^^^^^^^^^^^^^^^^^^^^ impl doesn't use types inside crate
    |
-   = note: the impl does not reference only types defined in this crate
+   = note: `[MyType]` is not defined in the current create
    = note: define and implement a trait or new type instead
 
 error[E0117]: only traits defined in the current crate can be implemented for arbitrary types
@@ -78,7 +78,7 @@ error[E0117]: only traits defined in the current crate can be implemented for ar
 LL | impl Copy for &'static [NotSync] {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ impl doesn't use types inside crate
    |
-   = note: the impl does not reference only types defined in this crate
+   = note: `&'static [NotSync]` is not defined in the current create
    = note: define and implement a trait or new type instead
 
 error: aborting due to 10 previous errors