fix compile error for #[classmethod]/#[staticmethod] on magic methods

newsfragments/4654.fixed.md

@@ -0,0 +1 @@
+fix compile error for `#[classmethod]`/`#[staticmethod]` on magic methods

pyo3-macros-backend/src/method.rs

@@ -263,25 +263,25 @@ impl FnType {
             }
             FnType::FnClass(span) | FnType::FnNewClass(span) => {
                 let py = syn::Ident::new("py", Span::call_site());
-                let slf: Ident = syn::Ident::new("_slf_ref", Span::call_site());
+                let slf: Ident = syn::Ident::new("_slf", Span::call_site());
                 let pyo3_path = pyo3_path.to_tokens_spanned(*span);
                 let ret = quote_spanned! { *span =>
                     #[allow(clippy::useless_conversion)]
                     ::std::convert::Into::into(
-                        #pyo3_path::impl_::pymethods::BoundRef::ref_from_ptr(#py, &*(#slf as *const _ as *const *mut _))
+                        #pyo3_path::impl_::pymethods::BoundRef::ref_from_ptr(#py, &*(&#slf as *const _ as *const *mut _))
                             .downcast_unchecked::<#pyo3_path::types::PyType>()
                     ),
                 };
                 Some(ret)
             }
             FnType::FnModule(span) => {
                 let py = syn::Ident::new("py", Span::call_site());
-                let slf: Ident = syn::Ident::new("_slf_ref", Span::call_site());
+                let slf: Ident = syn::Ident::new("_slf", Span::call_site());
                 let pyo3_path = pyo3_path.to_tokens_spanned(*span);
                 let ret = quote_spanned! { *span =>
                     #[allow(clippy::useless_conversion)]
                     ::std::convert::Into::into(
-                        #pyo3_path::impl_::pymethods::BoundRef::ref_from_ptr(#py, &*(#slf as *const _ as *const *mut _))
+                        #pyo3_path::impl_::pymethods::BoundRef::ref_from_ptr(#py, &*(&#slf as *const _ as *const *mut _))
                             .downcast_unchecked::<#pyo3_path::types::PyModule>()
                     ),
                 };
@@ -766,7 +766,6 @@ impl<'a> FnSpec<'a> {
                         _slf: *mut #pyo3_path::ffi::PyObject,
                     ) -> #pyo3_path::PyResult<*mut #pyo3_path::ffi::PyObject> {
                         #deprecation
-                        let _slf_ref = &_slf;
                         let function = #rust_name; // Shadow the function name to avoid #3017
                         #init_holders
                         let result = #call;
@@ -789,7 +788,6 @@ impl<'a> FnSpec<'a> {
                         _kwnames: *mut #pyo3_path::ffi::PyObject
                     ) -> #pyo3_path::PyResult<*mut #pyo3_path::ffi::PyObject> {
                         #deprecation
-                        let _slf_ref = &_slf;
                         let function = #rust_name; // Shadow the function name to avoid #3017
                         #arg_convert
                         #init_holders
@@ -812,7 +810,6 @@ impl<'a> FnSpec<'a> {
                         _kwargs: *mut #pyo3_path::ffi::PyObject
                     ) -> #pyo3_path::PyResult<*mut #pyo3_path::ffi::PyObject> {
                         #deprecation
-                        let _slf_ref = &_slf;
                         let function = #rust_name; // Shadow the function name to avoid #3017
                         #arg_convert
                         #init_holders
@@ -838,7 +835,6 @@ impl<'a> FnSpec<'a> {
                     ) -> #pyo3_path::PyResult<*mut #pyo3_path::ffi::PyObject> {
                         use #pyo3_path::impl_::callback::IntoPyCallbackOutput;
                         #deprecation
-                        let _slf_ref = &_slf;
                         let function = #rust_name; // Shadow the function name to avoid #3017
                         #arg_convert
                         #init_holders

src/tests/hygiene/pymethods.rs

@@ -439,4 +439,14 @@ impl Clear {
 struct Dummy2;
 
 #[crate::pymethods(crate = "crate")]
-impl Dummy2 {}
+impl Dummy2 {
+    #[classmethod]
+    fn __len__(cls: &crate::Bound<'_, crate::types::PyType>) -> crate::PyResult<usize> {
+        ::std::result::Result::Ok(0)
+    }
+
+    #[staticmethod]
+    fn __repr__() -> &'static str {
+        "Dummy"
+    }
+}