c-variadic: allow inherent methods to be c-variadic

1 files changed, 40 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..4c468c1907b
--- /dev/null
+++ b/tests/ui/c-variadic/trait-method.rs
@@ -0,0 +1,40 @@
+// For now C-variadic arguments in trait methods are rejected, though we aim to lift this
+// restriction in the future. In particular we need to think about the interaction with
+// `dyn Trait` and the `ReifyShim`s that it may generate for methods.
+#![feature(c_variadic)]
+#![crate_type = "lib"]
+struct S;
+
+impl S {
+    unsafe extern "C" fn associated_function(mut ap: ...) -> i32 {
+        unsafe { ap.arg() }
+    }
+
+    unsafe extern "C" fn method(&self, mut ap: ...) -> i32 {
+        unsafe { ap.arg() }
+    }
+}
+
+trait T {
+    unsafe extern "C" fn trait_associated_function(mut ap: ...) -> i32 {
+        //~^ ERROR: associated functions cannot have a C variable argument list
+        unsafe { ap.arg() }
+    }
+
+    unsafe extern "C" fn trait_method(&self, mut ap: ...) -> i32 {
+        //~^ ERROR: associated functions cannot have a C variable argument list
+        unsafe { ap.arg() }
+    }
+}
+
+impl T for S {}
+
+fn main() {
+    unsafe {
+        assert_eq!(S::associated_function(32), 32);
+        assert_eq!(S.method(32), 32);
+
+        assert_eq!(S::trait_associated_function(32), 32);
+        assert_eq!(S.trait_method(32), 32);
+    }
+}