4 files changed, 53 insertions, 0 deletions
diff --git a/src/test/ui/type-alias-impl-trait/auxiliary/collect_hidden_types.rs b/src/test/ui/type-alias-impl-trait/auxiliary/collect_hidden_types.rs
new file mode 100644
index 000000000..75d20a6fe
--- /dev/null
+++ b/src/test/ui/type-alias-impl-trait/auxiliary/collect_hidden_types.rs
@@ -0,0 +1,21 @@
+#![feature(type_alias_impl_trait)]
+
+// edition:2018
+
+use std::future::Future;
+
+pub trait Service<Request> {
+    type Future: Future<Output = ()>;
+    fn call(&mut self, req: Request) -> Self::Future;
+}
+
+// NOTE: the pub(crate) here is critical
+pub(crate) fn new() -> () {}
+
+pub struct A;
+impl Service<()> for A {
+    type Future = impl Future<Output = ()>;
+    fn call(&mut self, _: ()) -> Self::Future {
+        async { new() }
+    }
+}
diff --git a/src/test/ui/type-alias-impl-trait/auxiliary/cross_crate_ice.rs b/src/test/ui/type-alias-impl-trait/auxiliary/cross_crate_ice.rs
new file mode 100644
index 000000000..e7bca2231
--- /dev/null
+++ b/src/test/ui/type-alias-impl-trait/auxiliary/cross_crate_ice.rs
@@ -0,0 +1,10 @@
+// Crate that exports an opaque `impl Trait` type. Used for testing cross-crate.
+
+#![crate_type = "rlib"]
+#![feature(type_alias_impl_trait)]
+
+pub type Foo = impl std::fmt::Debug;
+
+pub fn foo() -> Foo {
+    5
+}
diff --git a/src/test/ui/type-alias-impl-trait/auxiliary/cross_crate_ice2.rs b/src/test/ui/type-alias-impl-trait/auxiliary/cross_crate_ice2.rs
new file mode 100644
index 000000000..119f7df1f
--- /dev/null
+++ b/src/test/ui/type-alias-impl-trait/auxiliary/cross_crate_ice2.rs
@@ -0,0 +1,20 @@
+// Crate that exports an opaque `impl Trait` type. Used for testing cross-crate.
+
+#![crate_type = "rlib"]
+#![feature(type_alias_impl_trait)]
+
+pub trait View {
+    type Tmp: Iterator<Item = u32>;
+
+    fn test(&self) -> Self::Tmp;
+}
+
+pub struct X;
+
+impl View for X {
+    type Tmp = impl Iterator<Item = u32>;
+
+    fn test(&self) -> Self::Tmp {
+        vec![1, 2, 3].into_iter()
+    }
+}
diff --git a/src/test/ui/type-alias-impl-trait/auxiliary/foreign-crate.rs b/src/test/ui/type-alias-impl-trait/auxiliary/foreign-crate.rs
new file mode 100644
index 000000000..52802dd8f
--- /dev/null
+++ b/src/test/ui/type-alias-impl-trait/auxiliary/foreign-crate.rs
@@ -0,0 +1,2 @@
+pub trait ForeignTrait {}
+pub struct ForeignType<T>(pub T);