fix unintentional unsafe_code trigger

pyo3-macros-backend/src/pymethod.rs

@@ -766,7 +766,14 @@ pub fn impl_py_getter_def(
 
             // TODO: on MSRV 1.77+, we can use `::std::mem::offset_of!` here, and it should
             // make it possible for the `MaybeRuntimePyMethodDef` to be a `Static` variant.
-            let method_def = quote_spanned! {ty.span()=>
+            let generator = quote_spanned! { ty.span() =>
+                #pyo3_path::impl_::pyclass::MaybeRuntimePyMethodDef::Runtime(
+                    || GENERATOR.generate(#python_name, #doc)
+                )
+            };
+            // This is separate so that the unsafe below does not inherit the span and thus does not
+            // trigger the `unsafe_code` lint
+            let method_def = quote! {
                 #cfg_attrs
                 {
                     #[allow(unused_imports)]  // might not be used if all probes are positve
@@ -790,9 +797,7 @@ pub fn impl_py_getter_def(
                         { #pyo3_path::impl_::pyclass::IsIntoPyObjectRef::<#ty>::VALUE },
                         { #pyo3_path::impl_::pyclass::IsIntoPyObject::<#ty>::VALUE },
                     > = unsafe { #pyo3_path::impl_::pyclass::PyClassGetterGenerator::new() };
-                    #pyo3_path::impl_::pyclass::MaybeRuntimePyMethodDef::Runtime(
-                        || GENERATOR.generate(#python_name, #doc)
-                    )
+                    #generator
                 }
             };
 

tests/test_compile_error.rs

@@ -54,6 +54,8 @@ fn test_compile_errors() {
     #[cfg(any(not(Py_LIMITED_API), Py_3_10))] // to avoid PyFunctionArgument for &str
     t.compile_fail("tests/ui/invalid_cancel_handle.rs");
     t.pass("tests/ui/pymodule_missing_docs.rs");
+    #[cfg(not(Py_LIMITED_API))]
+    t.pass("tests/ui/forbid_unsafe.rs");
     #[cfg(all(Py_LIMITED_API, not(feature = "experimental-async")))]
     // output changes with async feature
     t.compile_fail("tests/ui/abi3_inheritance.rs");

tests/ui/forbid_unsafe.rs

@@ -0,0 +1,30 @@
+#![forbid(unsafe_code)]
+
+use pyo3::*;
+
+#[allow(unexpected_cfgs)]
+#[path = "../../src/tests/hygiene/mod.rs"]
+mod hygiene;
+
+mod gh_4394 {
+    use pyo3::prelude::*;
+
+    #[derive(Eq, Ord, PartialEq, PartialOrd, Clone)]
+    #[pyclass(get_all)]
+    pub struct VersionSpecifier {
+        pub(crate) operator: Operator,
+        pub(crate) version: Version,
+    }
+
+    #[derive(Eq, Ord, PartialEq, PartialOrd, Debug, Hash, Clone, Copy)]
+    #[pyo3::pyclass(eq, eq_int)]
+    pub enum Operator {
+        Equal,
+    }
+
+    #[derive(Clone, Eq, PartialEq, PartialOrd, Ord)]
+    #[pyclass]
+    pub struct Version;
+}
+
+fn main() {}