make non_snake_case lint allow extern no-mangle functions

Resolves #31924.

1 files changed, 18 insertions, 0 deletions

diff --git a/src/test/compile-fail/issue-31924-non-snake-ffi.rs b/src/test/compile-fail/issue-31924-non-snake-ffi.rs
new file mode 100644
index 00000000000..d9ce1159c0e
--- /dev/null
+++ b/src/test/compile-fail/issue-31924-non-snake-ffi.rs
@@ -0,0 +1,18 @@
+// Copyright 2017 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(rustc_attrs)]
+#![deny(non_snake_case)]
+
+#[no_mangle]
+pub extern "C" fn SparklingGenerationForeignFunctionInterface() {}
+
+#[rustc_error]
+fn main() {} //~ ERROR compilation successful