1 files changed, 35 insertions, 0 deletions
diff --git a/third_party/rust/uniffi_macros/src/object.rs b/third_party/rust/uniffi_macros/src/object.rs
new file mode 100644
index 0000000000..2f4988530c
--- /dev/null
+++ b/third_party/rust/uniffi_macros/src/object.rs
@@ -0,0 +1,35 @@
+use proc_macro2::{Ident, Span, TokenStream};
+use quote::quote;
+use syn::DeriveInput;
+use uniffi_meta::ObjectMetadata;
+
+use crate::util::{assert_type_eq, create_metadata_static_var};
+
+pub fn expand_object(input: DeriveInput, module_path: Vec<String>) -> TokenStream {
+    let ident = &input.ident;
+    let name = ident.to_string();
+    let metadata = ObjectMetadata { module_path, name };
+    let free_fn_ident = Ident::new(&metadata.free_ffi_symbol_name(), Span::call_site());
+    let meta_static_var = create_metadata_static_var(ident, metadata.into());
+    let type_assertion = assert_type_eq(ident, quote! { crate::uniffi_types::#ident });
+
+    quote! {
+        #[doc(hidden)]
+        #[no_mangle]
+        pub extern "C" fn #free_fn_ident(
+            ptr: *const ::std::ffi::c_void,
+            call_status: &mut ::uniffi::RustCallStatus
+        ) {
+            uniffi::call_with_output(call_status, || {
+                assert!(!ptr.is_null());
+                let ptr = ptr.cast::<#ident>();
+                unsafe {
+                    ::std::sync::Arc::decrement_strong_count(ptr);
+                }
+            });
+        }
+
+        #meta_static_var
+        #type_assertion
+    }
+}