Use more targeted spans for orphan rule errors

rust-lang · bors · Oct 29, 2019 · Oct 24, 2019 · Oct 25, 2019 · Oct 25, 2019
commit 9b4f811b7f646ebb7273fa3cf8f9d092a44058b5
diff --git a/src/librustc/traits/coherence.rs b/src/librustc/traits/coherence.rs
@@ -237,7 +237,7 @@ pub fn trait_ref_is_local_or_fundamental<'tcx>(
 }
 
 pub enum OrphanCheckErr<'tcx> {
-    NonLocalInputType(Vec<Ty<'tcx>>),
+    NonLocalInputType(Vec<(Ty<'tcx>, usize)>),
     UncoveredTy(Ty<'tcx>),
 }
 
@@ -391,8 +391,10 @@ 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))
+        for (i, input_ty) in trait_ref
+            .input_types()
+            .flat_map(|ty| uncover_fundamental_ty(tcx, ty, in_crate))
+            .enumerate()
         {
             debug!("orphan_check_trait_ref: check ty `{:?}`", input_ty);
             if ty_is_local(tcx, input_ty, in_crate) {
@@ -402,7 +404,7 @@ 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);
+            non_local_spans.push((input_ty, i));
         }
         // If we exit above loop, never found a local type.
         debug!("orphan_check_trait_ref: no local type");
@@ -413,7 +415,7 @@ fn orphan_check_trait_ref<'tcx>(
         // parameters to the trait, with the self type appearing
         // first.  Find the first input type that either references a
         // type parameter OR some local type.
-        for input_ty in trait_ref.input_types() {
+        for (i, input_ty) in trait_ref.input_types().enumerate() {
             if ty_is_local(tcx, input_ty, in_crate) {
                 debug!("orphan_check_trait_ref: ty_is_local `{:?}`", input_ty);
 
@@ -442,7 +444,7 @@ fn orphan_check_trait_ref<'tcx>(
                 return Err(OrphanCheckErr::UncoveredTy(param));
             }
 
-            non_local_spans.push(input_ty);
+            non_local_spans.push((input_ty, i));
         }
         // If we exit above loop, never found a local type.
         debug!("orphan_check_trait_ref: no local type");

diff --git a/src/librustc_typeck/coherence/orphan.rs b/src/librustc_typeck/coherence/orphan.rs
@@ -24,7 +24,7 @@ impl ItemLikeVisitor<'v> for OrphanChecker<'tcx> {
     fn visit_item(&mut self, item: &hir::Item) {
         let def_id = self.tcx.hir().local_def_id(item.hir_id);
         // "Trait" impl
-        if let hir::ItemKind::Impl(.., Some(_), _, _) = item.kind {
+        if let hir::ItemKind::Impl(.., generics, Some(_), impl_ty, _) = &item.kind {
             debug!("coherence2::orphan check: trait impl {}",
                    self.tcx.hir().node_to_string(item.hir_id));
             let trait_ref = self.tcx.impl_trait_ref(def_id).unwrap();
@@ -41,28 +41,43 @@ impl ItemLikeVisitor<'v> for OrphanChecker<'tcx> {
                         "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.span_label(sp, "impl doesn't use only types from inside the current crate");
+                    for (ty, i) in &tys {
+                        let msg = format!("`{}` is not defined in the current crate", ty);
+                        if *i == 0 {
+                            err.span_label(impl_ty.span, &msg);
+                        } else {
+                            err.note(&msg);
+                        }
                     }
                     err.note("define and implement a trait or new type instead");
                     err.emit();
                     return;
                 }
                 Err(traits::OrphanCheckErr::UncoveredTy(param_ty)) => {
-                    struct_span_err!(self.tcx.sess,
-                                     sp,
-                                     E0210,
-                                     "type parameter `{}` must be used as the type parameter \
-                                      for some local type (e.g., `MyStruct<{}>`)",
-                                     param_ty,
-                                     param_ty)
-                        .span_label(sp,
-                                    format!("type parameter `{}` must be used as the type \
-                                             parameter for some local type", param_ty))
-                        .note("only traits defined in the current crate can be implemented \
-                               for a type parameter")
-                        .emit();
+                    let mut sp = sp;
+                    for param in &generics.params {
+                        if param.name.ident().to_string() == param_ty.to_string() {
+                            sp = param.span;
+                        }
+                    }
+                    let mut err = struct_span_err!(
+                        self.tcx.sess,
+                        sp,
+                        E0210,
+                        "type parameter `{}` must be used as the type parameter for some local \
+                         type (e.g., `MyStruct<{}>`)",
+                        param_ty,
+                        param_ty
+                    );
+                    err.span_label(sp, format!(
+                        "type parameter `{}` must be used as the type parameter for some local \
+                         type",
+                        param_ty,
+                    ));
+                    err.note("only traits defined in the current crate can be implemented for a \
+                              type parameter");
+                    err.emit();
                     return;
                 }
             }

diff --git a/src/test/ui/coherence/coherence-all-remote.old.stderr b/src/test/ui/coherence/coherence-all-remote.old.stderr
@@ -1,8 +1,8 @@
 error[E0210]: type parameter `T` must be used as the type parameter for some local type (e.g., `MyStruct<T>`)
-  --> $DIR/coherence-all-remote.rs:9:1
+  --> $DIR/coherence-all-remote.rs:9:6
    |
 LL | impl<T> Remote1<T> for isize { }
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type parameter `T` must be used as the type parameter for some local type
+   |      ^ type parameter `T` must be used as the type parameter for some local type
    |
    = note: only traits defined in the current crate can be implemented for a type parameter
 

diff --git a/src/test/ui/coherence/coherence-all-remote.re.stderr b/src/test/ui/coherence/coherence-all-remote.re.stderr
@@ -1,8 +1,8 @@
 error[E0210]: type parameter `T` must be used as the type parameter for some local type (e.g., `MyStruct<T>`)
-  --> $DIR/coherence-all-remote.rs:9:1
+  --> $DIR/coherence-all-remote.rs:9:6
    |
 LL | impl<T> Remote1<T> for isize { }
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type parameter `T` must be used as the type parameter for some local type
+   |      ^ type parameter `T` must be used as the type parameter for some local type
    |
    = note: only traits defined in the current crate can be implemented for a type parameter
 

diff --git a/src/test/ui/coherence/coherence-bigint-param.old.stderr b/src/test/ui/coherence/coherence-bigint-param.old.stderr
@@ -1,8 +1,8 @@
 error[E0210]: type parameter `T` must be used as the type parameter for some local type (e.g., `MyStruct<T>`)
-  --> $DIR/coherence-bigint-param.rs:11:1
+  --> $DIR/coherence-bigint-param.rs:11:6
    |
 LL | impl<T> Remote1<BigInt> for T { }
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type parameter `T` must be used as the type parameter for some local type
+   |      ^ type parameter `T` must be used as the type parameter for some local type
    |
    = note: only traits defined in the current crate can be implemented for a type parameter
 

diff --git a/src/test/ui/coherence/coherence-bigint-param.re.stderr b/src/test/ui/coherence/coherence-bigint-param.re.stderr
@@ -1,8 +1,8 @@
 error[E0210]: type parameter `T` must be used as the type parameter for some local type (e.g., `MyStruct<T>`)
-  --> $DIR/coherence-bigint-param.rs:11:1
+  --> $DIR/coherence-bigint-param.rs:11:6
    |
 LL | impl<T> Remote1<BigInt> for T { }
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type parameter `T` must be used as the type parameter for some local type
+   |      ^ type parameter `T` must be used as the type parameter for some local type
    |
    = note: only traits defined in the current crate can be implemented for a type parameter
 

diff --git a/src/test/ui/coherence/coherence-cow.a.stderr b/src/test/ui/coherence/coherence-cow.a.stderr
@@ -1,8 +1,8 @@
 error[E0210]: type parameter `T` must be used as the type parameter for some local type (e.g., `MyStruct<T>`)
-  --> $DIR/coherence-cow.rs:18:1
+  --> $DIR/coherence-cow.rs:18:6
    |
 LL | impl<T> Remote for Pair<T,Cover<T>> { }
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type parameter `T` must be used as the type parameter for some local type
+   |      ^ type parameter `T` must be used as the type parameter for some local type
    |
    = note: only traits defined in the current crate can be implemented for a type parameter
 

diff --git a/src/test/ui/coherence/coherence-cow.b.stderr b/src/test/ui/coherence/coherence-cow.b.stderr
@@ -1,8 +1,8 @@
 error[E0210]: type parameter `T` must be used as the type parameter for some local type (e.g., `MyStruct<T>`)
-  --> $DIR/coherence-cow.rs:23:1
+  --> $DIR/coherence-cow.rs:23:6
    |
 LL | impl<T> Remote for Pair<Cover<T>,T> { }
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type parameter `T` must be used as the type parameter for some local type
+   |      ^ type parameter `T` must be used as the type parameter for some local type
    |
    = note: only traits defined in the current crate can be implemented for a type parameter
 

diff --git a/src/test/ui/coherence/coherence-cow.c.stderr b/src/test/ui/coherence/coherence-cow.c.stderr
@@ -1,8 +1,8 @@
 error[E0210]: type parameter `T` must be used as the type parameter for some local type (e.g., `MyStruct<T>`)
-  --> $DIR/coherence-cow.rs:28:1
+  --> $DIR/coherence-cow.rs:28:6
    |
 LL | impl<T,U> Remote for Pair<Cover<T>,U> { }
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type parameter `T` must be used as the type parameter for some local type
+   |      ^ type parameter `T` must be used as the type parameter for some local type
    |
    = note: only traits defined in the current crate can be implemented for a type parameter
 

diff --git a/src/test/ui/coherence/coherence-cow.re_a.stderr b/src/test/ui/coherence/coherence-cow.re_a.stderr
@@ -2,9 +2,11 @@ error[E0117]: only traits defined in the current crate can be implemented for ar
   --> $DIR/coherence-cow.rs:18:1
    |
 LL | impl<T> Remote for Pair<T,Cover<T>> { }
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ impl doesn't use types inside crate
+   | ^^^^^^^^^^^^^^^^^^^----------------
+   | |                  |
+   | |                  `lib::Pair<T, Cover<T>>` is not defined in the current crate
+   | impl doesn't use only types from inside the current 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

diff --git a/src/test/ui/coherence/coherence-cow.re_b.stderr b/src/test/ui/coherence/coherence-cow.re_b.stderr
@@ -2,9 +2,11 @@ error[E0117]: only traits defined in the current crate can be implemented for ar
   --> $DIR/coherence-cow.rs:23:1
    |
 LL | impl<T> Remote for Pair<Cover<T>,T> { }
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ impl doesn't use types inside crate
+   | ^^^^^^^^^^^^^^^^^^^----------------
+   | |                  |
+   | |                  `lib::Pair<Cover<T>, T>` is not defined in the current crate
+   | impl doesn't use only types from inside the current 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

diff --git a/src/test/ui/coherence/coherence-cow.re_c.stderr b/src/test/ui/coherence/coherence-cow.re_c.stderr
@@ -2,9 +2,11 @@ error[E0117]: only traits defined in the current crate can be implemented for ar
   --> $DIR/coherence-cow.rs:28:1
    |
 LL | impl<T,U> Remote for Pair<Cover<T>,U> { }
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ impl doesn't use types inside crate
+   | ^^^^^^^^^^^^^^^^^^^^^----------------
+   | |                    |
+   | |                    `lib::Pair<Cover<T>, U>` is not defined in the current crate
+   | impl doesn't use only types from inside the current 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

diff --git a/src/test/ui/coherence/coherence-cross-crate-conflict.old.stderr b/src/test/ui/coherence/coherence-cross-crate-conflict.old.stderr
@@ -8,10 +8,10 @@ LL | impl<A> Foo for A {
            - impl trait_impl_conflict::Foo for isize;
 
 error[E0210]: type parameter `A` must be used as the type parameter for some local type (e.g., `MyStruct<A>`)
-  --> $DIR/coherence-cross-crate-conflict.rs:12:1
+  --> $DIR/coherence-cross-crate-conflict.rs:12:6
    |
 LL | impl<A> Foo for A {
-   | ^^^^^^^^^^^^^^^^^ type parameter `A` must be used as the type parameter for some local type
+   |      ^ type parameter `A` must be used as the type parameter for some local type
    |
    = note: only traits defined in the current crate can be implemented for a type parameter
 

diff --git a/src/test/ui/coherence/coherence-cross-crate-conflict.re.stderr b/src/test/ui/coherence/coherence-cross-crate-conflict.re.stderr
@@ -8,10 +8,10 @@ LL | impl<A> Foo for A {
            - impl trait_impl_conflict::Foo for isize;
 
 error[E0210]: type parameter `A` must be used as the type parameter for some local type (e.g., `MyStruct<A>`)
-  --> $DIR/coherence-cross-crate-conflict.rs:12:1
+  --> $DIR/coherence-cross-crate-conflict.rs:12:6
    |
 LL | impl<A> Foo for A {
-   | ^^^^^^^^^^^^^^^^^ type parameter `A` must be used as the type parameter for some local type
+   |      ^ type parameter `A` must be used as the type parameter for some local type
    |
    = note: only traits defined in the current crate can be implemented for a type parameter
 

diff --git a/src/test/ui/coherence/coherence-fundamental-trait-objects.old.stderr b/src/test/ui/coherence/coherence-fundamental-trait-objects.old.stderr
@@ -2,9 +2,11 @@ error[E0117]: only traits defined in the current crate can be implemented for ar
   --> $DIR/coherence-fundamental-trait-objects.rs:15:1
    |
 LL | impl Misc for dyn Fundamental<Local> {}
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ impl doesn't use types inside crate
+   | ^^^^^^^^^^^^^^----------------------
+   | |             |
+   | |             `(dyn coherence_fundamental_trait_lib::Fundamental<Local> + 'static)` is not defined in the current crate
+   | impl doesn't use only types from inside the current 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

diff --git a/src/test/ui/coherence/coherence-fundamental-trait-objects.re.stderr b/src/test/ui/coherence/coherence-fundamental-trait-objects.re.stderr
@@ -2,9 +2,11 @@ error[E0117]: only traits defined in the current crate can be implemented for ar
   --> $DIR/coherence-fundamental-trait-objects.rs:15:1
    |
 LL | impl Misc for dyn Fundamental<Local> {}
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ impl doesn't use types inside crate
+   | ^^^^^^^^^^^^^^----------------------
+   | |             |
+   | |             `(dyn coherence_fundamental_trait_lib::Fundamental<Local> + 'static)` is not defined in the current crate
+   | impl doesn't use only types from inside the current 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

diff --git a/src/test/ui/coherence/coherence-impl-trait-for-marker-trait-negative.stderr b/src/test/ui/coherence/coherence-impl-trait-for-marker-trait-negative.stderr
@@ -14,9 +14,11 @@ error[E0117]: only traits defined in the current crate can be implemented for ar
   --> $DIR/coherence-impl-trait-for-marker-trait-negative.rs:22:1
    |
 LL | impl !Send for dyn Marker2 {}
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^ impl doesn't use types inside crate
+   | ^^^^^^^^^^^^^^^-----------
+   | |              |
+   | |              `(dyn Marker2 + 'static)` is not defined in the current crate
+   | impl doesn't use only types from inside the current 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)`

diff --git a/src/test/ui/coherence/coherence-impl-trait-for-marker-trait-positive.stderr b/src/test/ui/coherence/coherence-impl-trait-for-marker-trait-positive.stderr
@@ -14,9 +14,11 @@ error[E0117]: only traits defined in the current crate can be implemented for ar
   --> $DIR/coherence-impl-trait-for-marker-trait-positive.rs:22:1
    |
 LL | unsafe impl Send for dyn Marker2 {}
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ impl doesn't use types inside crate
+   | ^^^^^^^^^^^^^^^^^^^^^-----------
+   | |                    |
+   | |                    `(dyn Marker2 + 'static)` is not defined in the current crate
+   | impl doesn't use only types from inside the current 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)`

diff --git a/src/test/ui/coherence/coherence-impls-copy.old.stderr b/src/test/ui/coherence/coherence-impls-copy.old.stderr
@@ -49,36 +49,44 @@ error[E0117]: only traits defined in the current crate can be implemented for ar
   --> $DIR/coherence-impls-copy.rs:8:1
    |
 LL | impl Copy for i32 {}
-   | ^^^^^^^^^^^^^^^^^ impl doesn't use types inside crate
+   | ^^^^^^^^^^^^^^---
+   | |             |
+   | |             `i32` is not defined in the current crate
+   | impl doesn't use only types from inside the current 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
   --> $DIR/coherence-impls-copy.rs:32:1
    |
 LL | impl Copy for (MyType, MyType) {}
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ impl doesn't use types inside crate
+   | ^^^^^^^^^^^^^^----------------
+   | |             |
+   | |             `(MyType, MyType)` is not defined in the current crate
+   | impl doesn't use only types from inside the current 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
   --> $DIR/coherence-impls-copy.rs:40:1
    |
 LL | impl Copy for [MyType] {}
-   | ^^^^^^^^^^^^^^^^^^^^^^ impl doesn't use types inside crate
+   | ^^^^^^^^^^^^^^--------
+   | |             |
+   | |             `[MyType]` is not defined in the current crate
+   | impl doesn't use only types from inside the current 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
   --> $DIR/coherence-impls-copy.rs:45:1
    |
 LL | impl Copy for &'static [NotSync] {}
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ impl doesn't use types inside crate
+   | ^^^^^^^^^^^^^^------------------
+   | |             |
+   | |             `&'static [NotSync]` is not defined in the current crate
+   | impl doesn't use only types from inside the current 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