verify py method args count

guide/src/class/protocols.md

@@ -288,7 +288,7 @@ This trait also has support the augmented arithmetic assignments (`+=`, `-=`,
   * `fn __itruediv__(&'p mut self, other: impl FromPyObject) -> PyResult<()>`
   * `fn __ifloordiv__(&'p mut self, other: impl FromPyObject) -> PyResult<()>`
   * `fn __imod__(&'p mut self, other: impl FromPyObject) -> PyResult<()>`
-  * `fn __ipow__(&'p mut self, other: impl FromPyObject) -> PyResult<()>`
+  * `fn __ipow__(&'p mut self, other: impl FromPyObject, _modulo: impl FromPyObject) -> PyResult<()>`
   * `fn __ilshift__(&'p mut self, other: impl FromPyObject) -> PyResult<()>`
   * `fn __irshift__(&'p mut self, other: impl FromPyObject) -> PyResult<()>`
   * `fn __iand__(&'p mut self, other: impl FromPyObject) -> PyResult<()>`

pyo3-macros-backend/Cargo.toml

@@ -18,6 +18,9 @@ quote = { version = "1", default-features = false }
 proc-macro2 = { version = "1", default-features = false }
 pyo3-build-config = { path = "../pyo3-build-config", version = "0.15.1", features = ["resolve-config"] }
 
+[build-dependencies]
+pyo3-build-config = { path = "../pyo3-build-config", version = "0.15.1", features = ["resolve-config"] }
+
 [dependencies.syn]
 version = "1"
 default-features = false

pyo3-macros-backend/build.rs

@@ -0,0 +1,14 @@
+use pyo3_build_config::pyo3_build_script_impl::{errors::Result, resolve_interpreter_config};
+
+fn configure_pyo3() -> Result<()> {
+    let interpreter_config = resolve_interpreter_config()?;
+    interpreter_config.emit_pyo3_cfgs();
+    Ok(())
+}
+
+fn main() {
+    if let Err(e) = configure_pyo3() {
+        eprintln!("error: {}", e.report());
+        std::process::exit(1)
+    }
+}

pyo3-macros-backend/src/defs.rs

@@ -420,6 +420,12 @@ pub const NUM: Proto = Proto {
         MethodProto::new("__imod__", "PyNumberIModProtocol")
             .args(&["Other"])
             .has_self(),
+        // See https://bugs.python.org/issue36379
+        #[cfg(Py_3_8)]
+        MethodProto::new("__ipow__", "PyNumberIPowProtocol")
+            .args(&["Other", "Modulo"])
+            .has_self(),
+        #[cfg(not(Py_3_8))]
         MethodProto::new("__ipow__", "PyNumberIPowProtocol")
             .args(&["Other"])
             .has_self(),

pyo3-macros-backend/src/pymethod.rs

@@ -532,10 +532,16 @@ const __IMOD__: SlotDef = SlotDef::new("Py_nb_inplace_remainder", "binaryfunc")
     .arguments(&[Ty::Object])
     .extract_error_mode(ExtractErrorMode::NotImplemented)
     .return_self();
+#[cfg(Py_3_8)]
 const __IPOW__: SlotDef = SlotDef::new("Py_nb_inplace_power", "ternaryfunc")
     .arguments(&[Ty::Object, Ty::Object])
     .extract_error_mode(ExtractErrorMode::NotImplemented)
     .return_self();
+#[cfg(not(Py_3_8))]
+const __IPOW__: SlotDef = SlotDef::new("Py_nb_inplace_power", "binaryfunc")
+    .arguments(&[Ty::Object])
+    .extract_error_mode(ExtractErrorMode::NotImplemented)
+    .return_self();
 const __ILSHIFT__: SlotDef = SlotDef::new("Py_nb_inplace_lshift", "binaryfunc")
     .arguments(&[Ty::Object])
     .extract_error_mode(ExtractErrorMode::NotImplemented)
@@ -856,8 +862,11 @@ fn generate_method_body(
 ) -> Result<TokenStream> {
     let self_conversion = spec.tp.self_conversion(Some(cls), extract_error_mode);
     let rust_name = spec.name;
-    let (arg_idents, conversions) =
+    let (arg_idents, arg_count, conversions) =
         extract_proto_arguments(cls, py, &spec.args, arguments, extract_error_mode)?;
+    if arg_count != arguments.len() {
+        bail_spanned!(spec.name.span() => format!("Expected {} arguments, got {}", arguments.len(), arg_count));
+    }
     let call = quote! { _pyo3::callback::convert(#py, #cls::#rust_name(_slf, #(#arg_idents),*)) };
     let body = if let Some(return_mode) = return_mode {
         return_mode.return_call_output(py, call)
@@ -1026,7 +1035,7 @@ fn extract_proto_arguments(
     method_args: &[FnArg],
     proto_args: &[Ty],
     extract_error_mode: ExtractErrorMode,
-) -> Result<(Vec<Ident>, TokenStream)> {
+) -> Result<(Vec<Ident>, usize, TokenStream)> {
     let mut arg_idents = Vec::with_capacity(method_args.len());
     let mut non_python_args = 0;
 
@@ -1045,9 +1054,8 @@ fn extract_proto_arguments(
             arg_idents.push(ident);
         }
     }
-
     let conversions = quote!(#(#args_conversions)*);
-    Ok((arg_idents, conversions))
+    Ok((arg_idents, non_python_args, conversions))
 }
 
 struct StaticIdent(&'static str);

src/class/number.rs

@@ -221,6 +221,14 @@ pub trait PyNumberProtocol<'p>: PyClass {
     {
         unimplemented!()
     }
+    #[cfg(Py_3_8)]
+    fn __ipow__(&'p mut self, other: Self::Other, modulo: Option<Self::Modulo>) -> Self::Result
+    where
+        Self: PyNumberIPowProtocol<'p>,
+    {
+        unimplemented!()
+    }
+    #[cfg(not(Py_3_8))]
     fn __ipow__(&'p mut self, other: Self::Other) -> Self::Result
     where
         Self: PyNumberIPowProtocol<'p>,
@@ -504,6 +512,8 @@ pub trait PyNumberIDivmodProtocol<'p>: PyNumberProtocol<'p> {
 pub trait PyNumberIPowProtocol<'p>: PyNumberProtocol<'p> {
     type Other: FromPyObject<'p>;
     type Result: IntoPyCallbackOutput<()>;
+    #[cfg(Py_3_8)]
+    type Modulo: FromPyObject<'p>;
 }
 
 #[allow(clippy::upper_case_acronyms)]
@@ -714,11 +724,13 @@ py_binary_self_func!(isub, PyNumberISubProtocol, T::__isub__);
 py_binary_self_func!(imul, PyNumberIMulProtocol, T::__imul__);
 py_binary_self_func!(imod, PyNumberIModProtocol, T::__imod__);
 
+// See https://bugs.python.org/issue36379
 #[doc(hidden)]
+#[cfg(Py_3_8)]
 pub unsafe extern "C" fn ipow<T>(
     slf: *mut ffi::PyObject,
     other: *mut ffi::PyObject,
-    _modulo: *mut ffi::PyObject,
+    modulo: *mut ffi::PyObject,
 ) -> *mut ffi::PyObject
 where
     T: for<'p> PyNumberIPowProtocol<'p>,
@@ -728,7 +740,35 @@ where
     crate::callback_body!(py, {
         let slf_cell = py.from_borrowed_ptr::<crate::PyCell<T>>(slf);
         let other = py.from_borrowed_ptr::<crate::PyAny>(other);
-        call_operator_mut!(py, slf_cell, __ipow__, other).convert(py)?;
+        let modulo = py.from_borrowed_ptr::<crate::PyAny>(modulo);
+        slf_cell
+            .try_borrow_mut()?
+            .__ipow__(
+                extract_or_return_not_implemented!(other),
+                extract_or_return_not_implemented!(modulo),
+            )
+            .convert(py)?;
+        ffi::Py_INCREF(slf);
+        Ok::<_, PyErr>(slf)
+    })
+}
+
+#[doc(hidden)]
+#[cfg(not(Py_3_8))]
+pub unsafe extern "C" fn ipow<T>(
+    slf: *mut ffi::PyObject,
+    other: *mut ffi::PyObject,
+) -> *mut ffi::PyObject
+where
+    T: for<'p> PyNumberIPowProtocol<'p>,
+{
+    crate::callback_body!(py, {
+        let slf_cell = py.from_borrowed_ptr::<crate::PyCell<T>>(slf);
+        let other = py.from_borrowed_ptr::<crate::PyAny>(other);
+        slf_cell
+            .try_borrow_mut()?
+            .__ipow__(extract_or_return_not_implemented!(other))
+            .convert(py)?;
         ffi::Py_INCREF(slf);
         Ok::<_, PyErr>(slf)
     })