Fix compile error when trying to use static slot methods, fixes: #3039

newsfragments/3055.fixed.md

@@ -0,0 +1 @@
+compile error in generated code for a `#[staticmethod]` occupying a slot

pyo3-macros-backend/src/pymethod.rs

@@ -1195,9 +1195,10 @@ fn generate_method_body(
     return_mode: Option<&ReturnMode>,
 ) -> Result<TokenStream> {
     let self_conversion = spec.tp.self_conversion(Some(cls), extract_error_mode);
+    let self_arg = spec.tp.self_arg();
     let rust_name = spec.name;
     let args = extract_proto_arguments(py, spec, arguments, extract_error_mode)?;
-    let call = quote! { _pyo3::callback::convert(#py, #cls::#rust_name(_slf, #(#args),*)) };
+    let call = quote! { _pyo3::callback::convert(#py, #cls::#rust_name(#self_arg #(#args),*)) };
     let body = if let Some(return_mode) = return_mode {
         return_mode.return_call_output(py, call)
     } else {

tests/test_static_slots.rs

@@ -0,0 +1,71 @@
+#![cfg(feature = "macros")]
+
+use pyo3::exceptions::PyIndexError;
+use pyo3::prelude::*;
+use pyo3::types::IntoPyDict;
+
+use pyo3::py_run;
+
+mod common;
+
+#[pyclass]
+struct Count5();
+
+#[pymethods]
+impl Count5 {
+    #[new]
+    fn new() -> Self {
+        Self()
+    }
+
+    #[staticmethod]
+    fn __len__() -> usize {
+        5
+    }
+
+    #[staticmethod]
+    fn __getitem__(idx: isize) -> PyResult<f64> {
+        if idx < 0 {
+            Err(PyIndexError::new_err("Count5 cannot count backwards"))
+        } else if idx > 4 {
+            Err(PyIndexError::new_err("Count5 cannot count higher than 5"))
+        } else {
+            Ok(idx as f64 + 1.0)
+        }
+    }
+}
+
+/// Return a dict with `s = Count5()`.
+fn test_dict(py: Python<'_>) -> &pyo3::types::PyDict {
+    let d = [("Count5", py.get_type::<Count5>())].into_py_dict(py);
+    // Though we can construct `s` in Rust, let's test `__new__` works.
+    py_run!(py, *d, "s = Count5()");
+    d
+}
+
+#[test]
+fn test_len() {
+    Python::with_gil(|py| {
+        let d = test_dict(py);
+
+        py_assert!(py, *d, "len(s) == 5");
+    });
+}
+
+#[test]
+fn test_getitem() {
+    Python::with_gil(|py| {
+        let d = test_dict(py);
+
+        py_assert!(py, *d, "s[4] == 5.0");
+    });
+}
+
+#[test]
+fn test_list() {
+    Python::with_gil(|py| {
+        let d = test_dict(py);
+
+        py_assert!(py, *d, "list(s) == [1.0, 2.0, 3.0, 4.0, 5.0]");
+    });
+}