1 files changed, 30 insertions, 0 deletions
diff --git a/tests/ui/phantom-auto-trait.rs b/tests/ui/phantom-auto-trait.rs
new file mode 100644
index 000000000..0172ca335
--- /dev/null
+++ b/tests/ui/phantom-auto-trait.rs
@@ -0,0 +1,30 @@
+// Ensure that auto trait checks `T` when it encounters a `PhantomData<T>` field, instead of
+// checking the `PhantomData<T>` type itself (which almost always implements an auto trait).
+
+#![feature(auto_traits)]
+
+use std::marker::{PhantomData};
+
+unsafe auto trait Zen {}
+
+unsafe impl<'a, T: 'a> Zen for &'a T where T: Sync {}
+
+struct Guard<'a, T: 'a> {
+    _marker: PhantomData<&'a T>,
+}
+
+struct Nested<T>(T);
+
+fn is_zen<T: Zen>(_: T) {}
+
+fn not_sync<T>(x: Guard<T>) {
+    is_zen(x)
+    //~^ ERROR `T` cannot be shared between threads safely [E0277]
+}
+
+fn nested_not_sync<T>(x: Nested<Guard<T>>) {
+    is_zen(x)
+    //~^ ERROR `T` cannot be shared between threads safely [E0277]
+}
+
+fn main() {}