1 files changed, 73 insertions, 0 deletions
diff --git a/tests/ui/c-variadic/trait-method.rs b/tests/ui/c-variadic/trait-method.rs
new file mode 100644
index 00000000000..97da0706a3a
--- /dev/null
+++ b/tests/ui/c-variadic/trait-method.rs
@@ -0,0 +1,73 @@
+//@ run-pass
+#![feature(c_variadic)]
+
+#[repr(transparent)]
+struct Struct(i32);
+
+impl Struct {
+    unsafe extern "C" fn associated_function(mut ap: ...) -> i32 {
+        unsafe { ap.arg() }
+    }
+
+    unsafe extern "C" fn method(&self, mut ap: ...) -> i32 {
+        self.0 + unsafe { ap.arg::<i32>() }
+    }
+}
+
+trait Trait: Sized {
+    fn get(&self) -> i32;
+
+    unsafe extern "C" fn trait_associated_function(mut ap: ...) -> i32 {
+        unsafe { ap.arg() }
+    }
+
+    unsafe extern "C" fn trait_method_owned(self, mut ap: ...) -> i32 {
+        self.get() + unsafe { ap.arg::<i32>() }
+    }
+
+    unsafe extern "C" fn trait_method_ref(&self, mut ap: ...) -> i32 {
+        self.get() + unsafe { ap.arg::<i32>() }
+    }
+
+    unsafe extern "C" fn trait_method_mut(&mut self, mut ap: ...) -> i32 {
+        self.get() + unsafe { ap.arg::<i32>() }
+    }
+
+    unsafe extern "C" fn trait_fat_pointer(self: Box<Self>, mut ap: ...) -> i32 {
+        self.get() + unsafe { ap.arg::<i32>() }
+    }
+}
+
+impl Trait for Struct {
+    fn get(&self) -> i32 {
+        self.0
+    }
+}
+
+fn main() {
+    unsafe {
+        assert_eq!(Struct::associated_function(32), 32);
+        assert_eq!(Struct(100).method(32), 132);
+
+        assert_eq!(Struct::trait_associated_function(32), 32);
+        assert_eq!(Struct(100).trait_method_owned(32), 132);
+        assert_eq!(Struct(100).trait_method_ref(32), 132);
+        assert_eq!(Struct(100).trait_method_mut(32), 132);
+        assert_eq!(Struct::trait_fat_pointer(Box::new(Struct(100)), 32), 132);
+
+        assert_eq!(<Struct as Trait>::trait_associated_function(32), 32);
+        assert_eq!(Trait::trait_method_owned(Struct(100), 32), 132);
+        assert_eq!(Trait::trait_method_ref(&Struct(100), 32), 132);
+        assert_eq!(Trait::trait_method_mut(&mut Struct(100), 32), 132);
+        assert_eq!(Trait::trait_fat_pointer(Box::new(Struct(100)), 32), 132);
+
+        type Associated = unsafe extern "C" fn(...) -> i32;
+        type Method<T> = unsafe extern "C" fn(T, ...) -> i32;
+
+        assert_eq!((Struct::trait_associated_function as Associated)(32), 32);
+        assert_eq!((Struct::trait_method_owned as Method<_>)(Struct(100), 32), 132);
+        assert_eq!((Struct::trait_method_ref as Method<_>)(&Struct(100), 32), 132);
+        assert_eq!((Struct::trait_method_mut as Method<_>)(&mut Struct(100), 32), 132);
+        assert_eq!((Struct::trait_fat_pointer as Method<_>)(Box::new(Struct(100)), 32), 132);
+    }
+}