14 files changed, 244 insertions, 0 deletions
diff --git a/src/test/ui/error-codes/e0119/auxiliary/complex_impl_support.rs b/src/test/ui/error-codes/e0119/auxiliary/complex_impl_support.rs
new file mode 100644
index 000000000..ad5bb107f
--- /dev/null
+++ b/src/test/ui/error-codes/e0119/auxiliary/complex_impl_support.rs
@@ -0,0 +1,22 @@
+use std::marker::PhantomData;
+
+pub trait External {}
+
+pub struct M<'a, 'b, 'c, T, U, V> {
+    a: PhantomData<&'a ()>,
+    b: PhantomData<&'b ()>,
+    c: PhantomData<&'c ()>,
+    d: PhantomData<T>,
+    e: PhantomData<U>,
+    f: PhantomData<V>,
+}
+
+impl<'a, 'b, 'c, T, U, V, W> External for (T, M<'a, 'b, 'c, Box<U>, V, W>)
+where
+    'b: 'a,
+    T: 'a,
+    U: (FnOnce(T) -> V) + 'static,
+    V: Iterator<Item=T> + Clone,
+    W: std::ops::Add,
+    W::Output: Copy,
+{}
diff --git a/src/test/ui/error-codes/e0119/auxiliary/issue-23563-a.rs b/src/test/ui/error-codes/e0119/auxiliary/issue-23563-a.rs
new file mode 100644
index 000000000..141f36369
--- /dev/null
+++ b/src/test/ui/error-codes/e0119/auxiliary/issue-23563-a.rs
@@ -0,0 +1,25 @@
+// Ref: https://github.com/rust-lang/rust/issues/23563#issuecomment-260751672
+
+pub trait LolTo<T> {
+    fn convert_to(&self) -> T;
+}
+
+pub trait LolInto<T>: Sized {
+    fn convert_into(self) -> T;
+}
+
+pub trait LolFrom<T> {
+    fn from(_: T) -> Self;
+}
+
+impl<'a, T: ?Sized, U> LolInto<U> for &'a T where T: LolTo<U> {
+    fn convert_into(self) -> U {
+        self.convert_to()
+    }
+}
+
+impl<T, U> LolFrom<T> for U where T: LolInto<U> {
+    fn from(t: T) -> U {
+        t.convert_into()
+    }
+}
diff --git a/src/test/ui/error-codes/e0119/complex-impl.rs b/src/test/ui/error-codes/e0119/complex-impl.rs
new file mode 100644
index 000000000..9149e4ce5
--- /dev/null
+++ b/src/test/ui/error-codes/e0119/complex-impl.rs
@@ -0,0 +1,11 @@
+// aux-build:complex_impl_support.rs
+
+extern crate complex_impl_support;
+
+use complex_impl_support::{External, M};
+
+struct Q;
+
+impl<R> External for (Q, R) {} //~ ERROR only traits defined
+
+fn main() {}
diff --git a/src/test/ui/error-codes/e0119/complex-impl.stderr b/src/test/ui/error-codes/e0119/complex-impl.stderr
new file mode 100644
index 000000000..654073eec
--- /dev/null
+++ b/src/test/ui/error-codes/e0119/complex-impl.stderr
@@ -0,0 +1,14 @@
+error[E0117]: only traits defined in the current crate can be implemented for arbitrary types
+  --> $DIR/complex-impl.rs:9:1
+   |
+LL | impl<R> External for (Q, R) {}
+   | ^^^^^^^^^^^^^^^^^^^^^------
+   | |                    |
+   | |                    this is not defined in the current crate because tuples are always foreign
+   | impl doesn't use only types from inside the current crate
+   |
+   = note: define and implement a trait or new type instead
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0117`.
diff --git a/src/test/ui/error-codes/e0119/conflict-with-std.rs b/src/test/ui/error-codes/e0119/conflict-with-std.rs
new file mode 100644
index 000000000..c9db2bab1
--- /dev/null
+++ b/src/test/ui/error-codes/e0119/conflict-with-std.rs
@@ -0,0 +1,26 @@
+use std::marker::PhantomData;
+use std::convert::{TryFrom, AsRef};
+
+struct Q;
+impl AsRef<Q> for Box<Q> { //~ ERROR conflicting implementations
+    fn as_ref(&self) -> &Q {
+        &**self
+    }
+}
+
+struct S;
+impl From<S> for S { //~ ERROR conflicting implementations
+    fn from(s: S) -> S {
+        s
+    }
+}
+
+struct X;
+impl TryFrom<X> for X { //~ ERROR conflicting implementations
+    type Error = ();
+    fn try_from(u: X) -> Result<X, ()> {
+        Ok(u)
+    }
+}
+
+fn main() {}
diff --git a/src/test/ui/error-codes/e0119/conflict-with-std.stderr b/src/test/ui/error-codes/e0119/conflict-with-std.stderr
new file mode 100644
index 000000000..3ff96a6a4
--- /dev/null
+++ b/src/test/ui/error-codes/e0119/conflict-with-std.stderr
@@ -0,0 +1,32 @@
+error[E0119]: conflicting implementations of trait `std::convert::AsRef<Q>` for type `std::boxed::Box<Q>`
+  --> $DIR/conflict-with-std.rs:5:1
+   |
+LL | impl AsRef<Q> for Box<Q> {
+   | ^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: conflicting implementation in crate `alloc`:
+           - impl<T, A> AsRef<T> for Box<T, A>
+             where A: Allocator, T: ?Sized;
+
+error[E0119]: conflicting implementations of trait `std::convert::From<S>` for type `S`
+  --> $DIR/conflict-with-std.rs:12:1
+   |
+LL | impl From<S> for S {
+   | ^^^^^^^^^^^^^^^^^^
+   |
+   = note: conflicting implementation in crate `core`:
+           - impl<T> From<T> for T;
+
+error[E0119]: conflicting implementations of trait `std::convert::TryFrom<X>` for type `X`
+  --> $DIR/conflict-with-std.rs:19:1
+   |
+LL | impl TryFrom<X> for X {
+   | ^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: conflicting implementation in crate `core`:
+           - impl<T, U> TryFrom<U> for T
+             where U: Into<T>;
+
+error: aborting due to 3 previous errors
+
+For more information about this error, try `rustc --explain E0119`.
diff --git a/src/test/ui/error-codes/e0119/issue-23563.rs b/src/test/ui/error-codes/e0119/issue-23563.rs
new file mode 100644
index 000000000..f578560c5
--- /dev/null
+++ b/src/test/ui/error-codes/e0119/issue-23563.rs
@@ -0,0 +1,29 @@
+// aux-build:issue-23563-a.rs
+
+// Ref: https://github.com/rust-lang/rust/issues/23563#issuecomment-260751672
+
+extern crate issue_23563_a as a;
+
+use a::LolFrom;
+use a::LolInto;
+use a::LolTo;
+
+struct LocalType<T>(Option<T>);
+
+impl<'a, T> LolFrom<&'a [T]> for LocalType<T> { //~ ERROR conflicting implementations of trait
+    fn from(_: &'a [T]) -> LocalType<T> { LocalType(None) }
+}
+
+impl<T> LolInto<LocalType<T>> for LocalType<T> {
+    fn convert_into(self) -> LocalType<T> {
+        self
+    }
+}
+
+impl LolTo<LocalType<u8>> for [u8] {
+    fn convert_to(&self) -> LocalType<u8> {
+        LocalType(None)
+    }
+}
+
+fn main() {}
diff --git a/src/test/ui/error-codes/e0119/issue-23563.stderr b/src/test/ui/error-codes/e0119/issue-23563.stderr
new file mode 100644
index 000000000..f149cef58
--- /dev/null
+++ b/src/test/ui/error-codes/e0119/issue-23563.stderr
@@ -0,0 +1,13 @@
+error[E0119]: conflicting implementations of trait `a::LolFrom<&[_]>` for type `LocalType<_>`
+  --> $DIR/issue-23563.rs:13:1
+   |
+LL | impl<'a, T> LolFrom<&'a [T]> for LocalType<T> {
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: conflicting implementation in crate `issue_23563_a`:
+           - impl<T, U> LolFrom<T> for U
+             where T: LolInto<U>;
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0119`.
diff --git a/src/test/ui/error-codes/e0119/issue-27403.rs b/src/test/ui/error-codes/e0119/issue-27403.rs
new file mode 100644
index 000000000..b03a564ff
--- /dev/null
+++ b/src/test/ui/error-codes/e0119/issue-27403.rs
@@ -0,0 +1,11 @@
+pub struct GenX<S> {
+    inner: S,
+}
+
+impl<S> Into<S> for GenX<S> { //~ ERROR conflicting implementations
+    fn into(self) -> S {
+        self.inner
+    }
+}
+
+fn main() {}
diff --git a/src/test/ui/error-codes/e0119/issue-27403.stderr b/src/test/ui/error-codes/e0119/issue-27403.stderr
new file mode 100644
index 000000000..c11a50487
--- /dev/null
+++ b/src/test/ui/error-codes/e0119/issue-27403.stderr
@@ -0,0 +1,13 @@
+error[E0119]: conflicting implementations of trait `std::convert::Into<_>` for type `GenX<_>`
+  --> $DIR/issue-27403.rs:5:1
+   |
+LL | impl<S> Into<S> for GenX<S> {
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: conflicting implementation in crate `core`:
+           - impl<T, U> Into<U> for T
+             where U: From<T>;
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0119`.
diff --git a/src/test/ui/error-codes/e0119/issue-28981.rs b/src/test/ui/error-codes/e0119/issue-28981.rs
new file mode 100644
index 000000000..5fb7e9a99
--- /dev/null
+++ b/src/test/ui/error-codes/e0119/issue-28981.rs
@@ -0,0 +1,7 @@
+use std::ops::Deref;
+
+struct Foo;
+
+impl<Foo> Deref for Foo { } //~ ERROR must be used
+
+fn main() {}
diff --git a/src/test/ui/error-codes/e0119/issue-28981.stderr b/src/test/ui/error-codes/e0119/issue-28981.stderr
new file mode 100644
index 000000000..97b570bc7
--- /dev/null
+++ b/src/test/ui/error-codes/e0119/issue-28981.stderr
@@ -0,0 +1,12 @@
+error[E0210]: type parameter `Foo` must be used as the type parameter for some local type (e.g., `MyStruct<Foo>`)
+  --> $DIR/issue-28981.rs:5:6
+   |
+LL | impl<Foo> Deref for Foo { }
+   |      ^^^ type parameter `Foo` must be used as the type parameter for some local type
+   |
+   = note: implementing a foreign trait is only possible if at least one of the types for which it is implemented is local
+   = note: only traits defined in the current crate can be implemented for a type parameter
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0210`.
diff --git a/src/test/ui/error-codes/e0119/so-37347311.rs b/src/test/ui/error-codes/e0119/so-37347311.rs
new file mode 100644
index 000000000..d5f624bc4
--- /dev/null
+++ b/src/test/ui/error-codes/e0119/so-37347311.rs
@@ -0,0 +1,17 @@
+// Ref: https://stackoverflow.com/q/37347311
+
+trait Storage {
+    type Error;
+}
+
+enum MyError<S: Storage> {
+    StorageProblem(S::Error),
+}
+
+impl<S: Storage> From<S::Error> for MyError<S> { //~ ERROR conflicting implementations
+    fn from(error: S::Error) -> MyError<S> {
+        MyError::StorageProblem(error)
+    }
+}
+
+fn main() {}
diff --git a/src/test/ui/error-codes/e0119/so-37347311.stderr b/src/test/ui/error-codes/e0119/so-37347311.stderr
new file mode 100644
index 000000000..f1c2b0d29
--- /dev/null
+++ b/src/test/ui/error-codes/e0119/so-37347311.stderr
@@ -0,0 +1,12 @@
+error[E0119]: conflicting implementations of trait `std::convert::From<MyError<_>>` for type `MyError<_>`
+  --> $DIR/so-37347311.rs:11:1
+   |
+LL | impl<S: Storage> From<S::Error> for MyError<S> {
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: conflicting implementation in crate `core`:
+           - impl<T> From<T> for T;
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0119`.