add test for issue 114907

Author: lqd

tests/ui/nll/missing-universe-cause-issue-114907.rs

@@ -0,0 +1,40 @@
+// This is a non-regression test for issue #114907 where an ICE happened because of missing
+// `UniverseInfo`s accessed during diagnostics.
+//
+// A couple notes:
+// - the `FnOnce` bounds need an arg that is a reference
+// - a custom `Drop` is needed somewhere in the type that `accept` returns, to create universes
+//   during liveness and dropck outlives computation
+
+// check-fail
+
+trait Role {
+    type Inner;
+}
+
+struct HandshakeCallback<C>(C);
+impl<C: FnOnce(&())> Role for HandshakeCallback<C> {
+    type Inner = ();
+}
+
+struct Handshake<R: Role> {
+    _inner: Option<R::Inner>,
+}
+impl<R: Role> Drop for Handshake<R> {
+    fn drop(&mut self) {}
+}
+
+fn accept<C: FnOnce(&())>(_: C) -> Handshake<HandshakeCallback<C>> {
+    todo!()
+}
+
+fn main() {
+    let callback = |_| {};
+    accept(callback);
+    //~^ ERROR mismatched types
+    //~| ERROR mismatched types
+    //~| ERROR implementation of `FnOnce` is not general enough
+    //~| ERROR implementation of `FnOnce` is not general enough
+    //~| ERROR higher-ranked subtype error
+    //~| ERROR higher-ranked subtype error
+}

tests/ui/nll/missing-universe-cause-issue-114907.stderr

@@ -0,0 +1,79 @@
+error[E0308]: mismatched types
+  --> $DIR/missing-universe-cause-issue-114907.rs:33:5
+   |
+LL |     accept(callback);
+   |     ^^^^^^^^^^^^^^^^ one type is more general than the other
+   |
+   = note: expected trait `for<'a> FnOnce<(&'a (),)>`
+              found trait `FnOnce<(&(),)>`
+note: this closure does not fulfill the lifetime requirements
+  --> $DIR/missing-universe-cause-issue-114907.rs:32:20
+   |
+LL |     let callback = |_| {};
+   |                    ^^^
+note: the lifetime requirement is introduced here
+  --> $DIR/missing-universe-cause-issue-114907.rs:27:14
+   |
+LL | fn accept<C: FnOnce(&())>(_: C) -> Handshake<HandshakeCallback<C>> {
+   |              ^^^^^^^^^^^
+help: consider specifying the type of the closure parameters
+   |
+LL |     let callback = |_: &_| {};
+   |                    ~~~~~~~
+
+error: implementation of `FnOnce` is not general enough
+  --> $DIR/missing-universe-cause-issue-114907.rs:33:5
+   |
+LL |     accept(callback);
+   |     ^^^^^^^^^^^^^^^^ implementation of `FnOnce` is not general enough
+   |
+   = note: closure with signature `fn(&'2 ())` must implement `FnOnce<(&'1 (),)>`, for any lifetime `'1`...
+   = note: ...but it actually implements `FnOnce<(&'2 (),)>`, for some specific lifetime `'2`
+
+error: implementation of `FnOnce` is not general enough
+  --> $DIR/missing-universe-cause-issue-114907.rs:33:5
+   |
+LL |     accept(callback);
+   |     ^^^^^^^^^^^^^^^^ implementation of `FnOnce` is not general enough
+   |
+   = note: closure with signature `fn(&'2 ())` must implement `FnOnce<(&'1 (),)>`, for any lifetime `'1`...
+   = note: ...but it actually implements `FnOnce<(&'2 (),)>`, for some specific lifetime `'2`
+
+error[E0308]: mismatched types
+  --> $DIR/missing-universe-cause-issue-114907.rs:33:5
+   |
+LL |     accept(callback);
+   |     ^^^^^^^^^^^^^^^^ one type is more general than the other
+   |
+   = note: expected trait `for<'a> FnOnce<(&'a (),)>`
+              found trait `FnOnce<(&(),)>`
+note: this closure does not fulfill the lifetime requirements
+  --> $DIR/missing-universe-cause-issue-114907.rs:32:20
+   |
+LL |     let callback = |_| {};
+   |                    ^^^
+note: the lifetime requirement is introduced here
+  --> $DIR/missing-universe-cause-issue-114907.rs:20:21
+   |
+LL | struct Handshake<R: Role> {
+   |                     ^^^^
+help: consider specifying the type of the closure parameters
+   |
+LL |     let callback = |_: &_| {};
+   |                    ~~~~~~~
+
+error: higher-ranked subtype error
+  --> $DIR/missing-universe-cause-issue-114907.rs:33:21
+   |
+LL |     accept(callback);
+   |                     ^
+
+error: higher-ranked subtype error
+  --> $DIR/missing-universe-cause-issue-114907.rs:33:21
+   |
+LL |     accept(callback);
+   |                     ^
+
+error: aborting due to 6 previous errors
+
+For more information about this error, try `rustc --explain E0308`.