Allow pymodule functions to take a single Bound<'_, PyModule> arg (#3905)

newsfragments/3905.changed.md

@@ -0,0 +1 @@
+The `#[pymodule]` macro now supports module functions that take a single argument as a `&Bound<'_, PyModule>`.

pyo3-macros-backend/src/module.rs

@@ -201,6 +201,14 @@ pub fn pymodule_function_impl(mut function: syn::ItemFn) -> Result<TokenStream>
     let doc = get_doc(&function.attrs, None);
 
     let initialization = module_initialization(options, ident);
+
+    // Module function called with optional Python<'_> marker as first arg, followed by the module.
+    let mut module_args = Vec::new();
+    if function.sig.inputs.len() == 2 {
+        module_args.push(quote!(module.py()));
+    }
+    module_args.push(quote!(::std::convert::Into::into(BoundRef(module))));
+
     Ok(quote! {
         #function
         #vis mod #ident {
@@ -218,7 +226,7 @@ pub fn pymodule_function_impl(mut function: syn::ItemFn) -> Result<TokenStream>
             use #krate::impl_::pymethods::BoundRef;
 
             fn __pyo3_pymodule(module: &#krate::Bound<'_, #krate::types::PyModule>) -> #krate::PyResult<()> {
-                #ident(module.py(), ::std::convert::Into::into(BoundRef(module)))
+                #ident(#(#module_args),*)
             }
 
             impl #ident::MakeDef {

src/tests/hygiene/pyfunction.rs

@@ -14,3 +14,11 @@ fn invoke_wrap_pyfunction() {
         crate::py_run!(py, func, r#"func(5)"#);
     });
 }
+
+#[test]
+fn invoke_wrap_pyfunction_bound() {
+    crate::Python::with_gil(|py| {
+        let func = crate::wrap_pyfunction_bound!(do_something, py).unwrap();
+        crate::py_run!(py, func, r#"func(5)"#);
+    });
+}

src/tests/hygiene/pymodule.rs

@@ -21,3 +21,18 @@ fn my_module(_py: crate::Python<'_>, m: &crate::types::PyModule) -> crate::PyRes
 
     ::std::result::Result::Ok(())
 }
+
+#[crate::pymodule]
+#[pyo3(crate = "crate")]
+fn my_module_bound(m: &crate::Bound<'_, crate::types::PyModule>) -> crate::PyResult<()> {
+    <crate::Bound<'_, crate::types::PyModule> as crate::types::PyModuleMethods>::add_function(
+        m,
+        crate::wrap_pyfunction_bound!(do_something, m)?,
+    )?;
+    <crate::Bound<'_, crate::types::PyModule> as crate::types::PyModuleMethods>::add_wrapped(
+        m,
+        crate::wrap_pymodule!(foo),
+    )?;
+
+    ::std::result::Result::Ok(())
+}

tests/test_no_imports.rs

@@ -22,6 +22,18 @@ fn basic_module(_py: pyo3::Python<'_>, m: &pyo3::types::PyModule) -> pyo3::PyRes
     Ok(())
 }
 
+#[pyo3::pymodule]
+fn basic_module_bound(m: &pyo3::Bound<'_, pyo3::types::PyModule>) -> pyo3::PyResult<()> {
+    #[pyfn(m)]
+    fn answer() -> usize {
+        42
+    }
+
+    m.add_function(pyo3::wrap_pyfunction_bound!(basic_function, m)?)?;
+
+    Ok(())
+}
+
 #[pyo3::pyclass]
 struct BasicClass {
     #[pyo3(get)]