From f3b44929856283c43742f86692349c27bb701034 Mon Sep 17 00:00:00 2001
From: Oliver Schneider <github35764891676564198441@oli-obk.de>
Date: Tue, 17 Jul 2018 15:11:00 +0200
Subject: [PATCH] Add some tests around associated types

---
 .../ui/existential_types/bound_reduction.rs   | 30 +++++++++++++++++++
 .../ui/existential_types/bound_reduction2.rs  | 28 +++++++++++++++++
 .../existential_types/bound_reduction2.stderr | 16 ++++++++++
 .../no_revealing_outside_defining_module.rs   |  2 +-
 .../ui/existential_types/not_well_formed.rs   | 28 +++++++++++++++++
 .../existential_types/not_well_formed.stderr  |  9 ++++++
 6 files changed, 112 insertions(+), 1 deletion(-)
 create mode 100644 src/test/ui/existential_types/bound_reduction.rs
 create mode 100644 src/test/ui/existential_types/bound_reduction2.rs
 create mode 100644 src/test/ui/existential_types/bound_reduction2.stderr
 create mode 100644 src/test/ui/existential_types/not_well_formed.rs
 create mode 100644 src/test/ui/existential_types/not_well_formed.stderr

diff --git a/src/test/ui/existential_types/bound_reduction.rs b/src/test/ui/existential_types/bound_reduction.rs
new file mode 100644
index 000000000000..2e42c92ab30a
--- /dev/null
+++ b/src/test/ui/existential_types/bound_reduction.rs
@@ -0,0 +1,30 @@
+// Copyright 2018 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// compile-pass
+
+#![allow(warnings)]
+
+#![feature(existential_type)]
+
+fn main() {
+}
+
+existential type Foo<V>: std::fmt::Debug;
+
+trait Trait<U> {}
+
+fn foo_desugared<T: Trait<[u32; {
+    #[no_mangle]
+    static FOO: usize = 42;
+    3
+}]>>(_: T) -> Foo<T> {
+    (42, std::marker::PhantomData::<T>)
+}
diff --git a/src/test/ui/existential_types/bound_reduction2.rs b/src/test/ui/existential_types/bound_reduction2.rs
new file mode 100644
index 000000000000..d098a4ef4c8e
--- /dev/null
+++ b/src/test/ui/existential_types/bound_reduction2.rs
@@ -0,0 +1,28 @@
+// Copyright 2018 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![feature(existential_type)]
+
+fn main() {
+}
+
+trait TraitWithAssoc {
+    type Assoc;
+}
+
+existential type Foo<V>: Trait<V>;
+
+trait Trait<U> {}
+
+impl<W> Trait<W> for () {}
+
+fn foo_desugared<T: TraitWithAssoc>(_: T) -> Foo<T::Assoc> { //~ ERROR non-defining
+    ()
+}
diff --git a/src/test/ui/existential_types/bound_reduction2.stderr b/src/test/ui/existential_types/bound_reduction2.stderr
new file mode 100644
index 000000000000..33b8b71bffb1
--- /dev/null
+++ b/src/test/ui/existential_types/bound_reduction2.stderr
@@ -0,0 +1,16 @@
+error: non-defining existential type use in defining scope
+  --> $DIR/bound_reduction2.rs:26:1
+   |
+LL | / fn foo_desugared<T: TraitWithAssoc>(_: T) -> Foo<T::Assoc> { //~ ERROR non-defining
+LL | |     ()
+LL | | }
+   | |_^
+   |
+note: used non-generic type <T as TraitWithAssoc>::Assoc for generic parameter
+  --> $DIR/bound_reduction2.rs:20:22
+   |
+LL | existential type Foo<V>: Trait<V>;
+   |                      ^
+
+error: aborting due to previous error
+
diff --git a/src/test/ui/existential_types/no_revealing_outside_defining_module.rs b/src/test/ui/existential_types/no_revealing_outside_defining_module.rs
index 41c17c357bc8..f646891b3b4f 100644
--- a/src/test/ui/existential_types/no_revealing_outside_defining_module.rs
+++ b/src/test/ui/existential_types/no_revealing_outside_defining_module.rs
@@ -32,4 +32,4 @@ fn bomp() -> boo::Boo {
 
 fn bomp_loop() -> boo::Boo {
     loop {}
-}
\ No newline at end of file
+}
diff --git a/src/test/ui/existential_types/not_well_formed.rs b/src/test/ui/existential_types/not_well_formed.rs
new file mode 100644
index 000000000000..b3d38aee8c53
--- /dev/null
+++ b/src/test/ui/existential_types/not_well_formed.rs
@@ -0,0 +1,28 @@
+// Copyright 2018 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![feature(existential_type)]
+
+fn main() {
+}
+
+trait TraitWithAssoc {
+    type Assoc;
+}
+
+existential type Foo<V>: Trait<V::Assoc>; //~ associated type `Assoc` not found for `V`
+
+trait Trait<U> {}
+
+impl<W> Trait<W> for () {}
+
+fn foo_desugared<T: TraitWithAssoc>(_: T) -> Foo<T> {
+    ()
+}
diff --git a/src/test/ui/existential_types/not_well_formed.stderr b/src/test/ui/existential_types/not_well_formed.stderr
new file mode 100644
index 000000000000..6b7d1be98a77
--- /dev/null
+++ b/src/test/ui/existential_types/not_well_formed.stderr
@@ -0,0 +1,9 @@
+error[E0220]: associated type `Assoc` not found for `V`
+  --> $DIR/not_well_formed.rs:20:32
+   |
+LL | existential type Foo<V>: Trait<V::Assoc>; //~ associated type `Assoc` not found for `V`
+   |                                ^^^^^^^^ associated type `Assoc` not found
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0220`.