fix FFI definition of PyDictObject on PyPy

newsfragments/5653.changed.md

@@ -0,0 +1 @@
+Disable subclassing `PyDict` on GraalPy (unsupported for now).

newsfragments/5653.fixed.md

@@ -0,0 +1 @@
+Fix FFI definition of `PyDictObject` on PyPy.

pyo3-ffi/src/cpython/dictobject.rs

@@ -7,7 +7,7 @@ opaque_struct!(pub PyDictKeysObject);
 #[cfg(Py_3_11)]
 opaque_struct!(pub PyDictValues);
 
-#[cfg(not(GraalPy))]
+#[cfg(not(any(GraalPy, PyPy)))]
 #[repr(C)]
 #[derive(Debug)]
 pub struct PyDictObject {
@@ -28,6 +28,14 @@ pub struct PyDictObject {
     pub ma_values: *mut PyDictValues,
 }
 
+#[cfg(PyPy)]
+#[repr(C)]
+#[derive(Debug)]
+pub struct PyDictObject {
+    pub ob_base: PyObject,
+    _tmpkeys: *mut PyObject,
+}
+
 extern "C" {
     // skipped _PyDict_GetItem_KnownHash
     // skipped _PyDict_GetItemIdWithError

pyo3-ffi/src/cpython/mod.rs

@@ -9,7 +9,6 @@ pub(crate) mod complexobject;
 #[cfg(Py_3_13)]
 pub(crate) mod critical_section;
 pub(crate) mod descrobject;
-#[cfg(not(PyPy))]
 pub(crate) mod dictobject;
 // skipped fileobject.h
 // skipped fileutils.h
@@ -53,7 +52,6 @@ pub use self::complexobject::*;
 #[cfg(Py_3_13)]
 pub use self::critical_section::*;
 pub use self::descrobject::*;
-#[cfg(not(PyPy))]
 pub use self::dictobject::*;
 pub use self::floatobject::*;
 pub use self::frameobject::*;

pyo3-ffi/src/dictobject.rs

@@ -116,6 +116,6 @@ extern "C" {
     pub static mut PyDictRevIterItem_Type: PyTypeObject;
 }
 
-#[cfg(any(PyPy, GraalPy, Py_LIMITED_API))]
+#[cfg(any(GraalPy, Py_LIMITED_API))]
 // TODO: remove (see https://github.com/PyO3/pyo3/pull/1341#issuecomment-751515985)
 opaque_struct!(pub PyDictObject);

src/types/dict.rs

@@ -16,6 +16,7 @@ use crate::{ffi, BoundObject, IntoPyObject, IntoPyObjectExt, Python};
 #[repr(transparent)]
 pub struct PyDict(PyAny);
 
+#[cfg(not(GraalPy))]
 pyobject_subclassable_native_type!(PyDict, crate::ffi::PyDictObject);
 
 pyobject_native_type!(