1 files changed, 27 insertions, 0 deletions
diff --git a/test/rubygems/test_gem_ext_cargo_builder/custom_name/ext/custom_name_lib/src/lib.rs b/test/rubygems/test_gem_ext_cargo_builder/custom_name/ext/custom_name_lib/src/lib.rs
new file mode 100644
index 0000000000..28ba3be564
--- /dev/null
+++ b/test/rubygems/test_gem_ext_cargo_builder/custom_name/ext/custom_name_lib/src/lib.rs
@@ -0,0 +1,27 @@
+extern crate rb_sys;
+
+use rb_sys::{rb_define_module, rb_define_module_function, rb_utf8_str_new, VALUE};
+use std::ffi::CString;
+
+#[no_mangle]
+unsafe extern "C" fn say_hello(_klass: VALUE) -> VALUE {
+    let cstr = CString::new("Hello world!").unwrap();
+
+    rb_utf8_str_new(cstr.as_ptr(), 12)
+}
+
+#[allow(non_snake_case)]
+#[no_mangle]
+pub extern "C" fn Init_custom_name_ext() {
+    let name = CString::new("CustomName").unwrap();
+    let function_name = CString::new("say_hello").unwrap();
+    // bindgen does not properly detect the arity of the ruby callback function, so we have to transmute
+    let callback = unsafe {
+        std::mem::transmute::<unsafe extern "C" fn(VALUE) -> VALUE, unsafe extern "C" fn() -> VALUE>(
+            say_hello,
+        )
+    };
+    let klass = unsafe { rb_define_module(name.as_ptr()) };
+
+    unsafe { rb_define_module_function(klass, function_name.as_ptr(), Some(callback), 0) }
+}