Python 3.15b1 ABI support

.github/workflows/ci.yml

@@ -206,6 +206,24 @@ jobs:
                 python-architecture: "x64",
                 rust-target: "x86_64-unknown-linux-gnu",
               }
+          # Also test Python 3.15 and 3.15t, on ubuntu
+          # (run for all OSes on build-full)
+          - rust: stable
+            python-version: "3.15-dev"
+            platform:
+              {
+                os: "ubuntu-latest",
+                python-architecture: "x64",
+                rust-target: "x86_64-unknown-linux-gnu",
+              }
+          - rust: stable
+            python-version: "3.15t-dev"
+            platform:
+              {
+                os: "ubuntu-latest",
+                python-architecture: "x64",
+                rust-target: "x86_64-unknown-linux-gnu",
+              }
 
   build-full:
     if: ${{ contains(github.event.pull_request.labels.*.name, 'CI-build-full') || github.event_name != 'pull_request' }}

newsfragments/6014.added.md

@@ -0,0 +1,4 @@
+* Added support for Python 3.15.0b1.
+* Added FFI bindings for the PEP 820 PySlot C API.
+* Added bindings for the critical section API in the limited API on Python 3.15
+  and newer.

newsfragments/6014.changed.md

@@ -0,0 +1 @@
+* Updated FFI bindings and module initialization to use PEP 820 PySlot API.

pyo3-build-config/src/lib.rs

@@ -181,6 +181,7 @@ fn print_feature_cfg(minor_version_required: u32, cfg: &str) {
 /// so this function is unstable.
 #[doc(hidden)]
 pub fn print_feature_cfgs() {
+    print_feature_cfg(84, "const_is_null");
     print_feature_cfg(85, "fn_ptr_eq");
     print_feature_cfg(86, "from_bytes_with_nul_error");
 }

pyo3-ffi-check/macro/src/lib.rs

@@ -187,6 +187,13 @@ pub fn for_all_fields(input: proc_macro::TokenStream) -> proc_macro::TokenStream
             // the field name in the C API is `type`, but that's a keyword in Rust
             // so PyO3 picked type_code, bindgen picked type_
             Ident::new("type_", Span::call_site())
+        } else if struct_name == "PySlot" && field_name == "anon1" {
+            // PySlot has two anonymous unions (since they aren't allowed in Rust,
+            // PyO3 invented names for them); bindgen names the first one __bindgen_anon_1
+            Ident::new("__bindgen_anon_1", Span::call_site())
+        } else if struct_name == "PySlot" && field_name == "anon2" {
+            // ...and the second one __bindgen_anon_2
+            Ident::new("__bindgen_anon_2", Span::call_site())
         } else {
             field_ident.clone()
         };
@@ -352,6 +359,15 @@ const MACRO_EXCLUSIONS: &[(&str, &str)] = &[
     ("PySet_CheckExact", "not(PyPy)"),
     ("PySet_GET_SIZE", ""),
     ("PySlice_Check", ""),
+    ("PySlot_DATA", ""),
+    ("PySlot_END", ""),
+    ("PySlot_FUNC", ""),
+    ("PySlot_INT64", ""),
+    ("PySlot_PTR", ""),
+    ("PySlot_PTR_STATIC", ""),
+    ("PySlot_SIZE", ""),
+    ("PySlot_STATIC_DATA", ""),
+    ("PySlot_UINT64", ""),
     ("PyStructSequence_GET_ITEM", ""),
     ("PyStructSequence_SET_ITEM", ""),
     ("PyTZInfo_Check", "not(PyPy)"),

pyo3-ffi/examples/sequential/src/lib.rs

@@ -17,6 +17,6 @@ pub unsafe extern "C" fn PyInit_sequential() -> *mut PyObject {
 #[cfg(Py_3_15)]
 #[allow(non_snake_case, reason = "must be named `PyModExport_<your_module>`")]
 #[no_mangle]
-pub unsafe extern "C" fn PyModExport_sequential() -> *mut PyModuleDef_Slot {
+pub unsafe extern "C" fn PyModExport_sequential() -> *mut PySlot {
     (&raw mut SEQUENTIAL_SLOTS).cast()
 }

pyo3-ffi/examples/sequential/src/module.rs

@@ -20,44 +20,33 @@ PyABIInfo_VAR!(ABI_INFO);
 
 const SEQUENTIAL_SLOTS_LEN: usize =
     2 + cfg!(Py_3_12) as usize + cfg!(Py_GIL_DISABLED) as usize + 7 * (cfg!(Py_3_15) as usize);
+#[cfg(Py_3_15)]
+pub static mut SEQUENTIAL_SLOTS: [PySlot; SEQUENTIAL_SLOTS_LEN] = [
+    PySlot_STATIC_DATA(Py_mod_abi, (&raw mut ABI_INFO).cast()),
+    PySlot_STATIC_DATA(Py_mod_name, c"sequential".as_ptr() as *mut c_void),
+    PySlot_STATIC_DATA(
+        Py_mod_doc,
+        c"A library for generating sequential ids, written in Rust.".as_ptr() as *mut c_void,
+    ),
+    PySlot_SIZE(
+        Py_mod_state_size,
+        mem::size_of::<sequential_state>() as Py_ssize_t,
+    ),
+    // safety: all these function pointers are non-null by construction
+    unsafe { PySlot_FUNC(Py_mod_state_traverse, sequential_traverse as *mut c_void) },
+    unsafe { PySlot_FUNC(Py_mod_state_clear, sequential_clear as *mut c_void) },
+    unsafe { PySlot_FUNC(Py_mod_state_free, sequential_free as *mut c_void) },
+    unsafe { PySlot_FUNC(Py_mod_exec, sequential_exec as *mut c_void) },
+    PySlot_DATA(
+        Py_mod_multiple_interpreters,
+        Py_MOD_PER_INTERPRETER_GIL_SUPPORTED,
+    ),
+    #[cfg(Py_GIL_DISABLED)]
+    PySlot_DATA(Py_mod_gil, Py_MOD_GIL_NOT_USED),
+    PySlot_END(),
+];
+#[cfg(not(Py_3_15))]
 pub static mut SEQUENTIAL_SLOTS: [PyModuleDef_Slot; SEQUENTIAL_SLOTS_LEN] = [
-    #[cfg(Py_3_15)]
-    PyModuleDef_Slot {
-        slot: Py_mod_abi,
-        value: (&raw mut ABI_INFO).cast(),
-    },
-    #[cfg(Py_3_15)]
-    PyModuleDef_Slot {
-        slot: Py_mod_name,
-        // safety: Python does not write to this field
-        value: c"sequential".as_ptr() as *mut c_void,
-    },
-    #[cfg(Py_3_15)]
-    PyModuleDef_Slot {
-        slot: Py_mod_doc,
-        // safety: Python does not write to this field
-        value: c"A library for generating sequential ids, written in Rust.".as_ptr() as *mut c_void,
-    },
-    #[cfg(Py_3_15)]
-    PyModuleDef_Slot {
-        slot: Py_mod_state_size,
-        value: mem::size_of::<sequential_state>() as *mut c_void,
-    },
-    #[cfg(Py_3_15)]
-    PyModuleDef_Slot {
-        slot: Py_mod_state_traverse,
-        value: sequential_traverse as *mut c_void,
-    },
-    #[cfg(Py_3_15)]
-    PyModuleDef_Slot {
-        slot: Py_mod_state_clear,
-        value: sequential_clear as *mut c_void,
-    },
-    #[cfg(Py_3_15)]
-    PyModuleDef_Slot {
-        slot: Py_mod_state_free,
-        value: sequential_free as *mut c_void,
-    },
     PyModuleDef_Slot {
         slot: Py_mod_exec,
         value: sequential_exec as *mut c_void,

pyo3-ffi/examples/string-sum/src/lib.rs

@@ -1,7 +1,6 @@
 #[cfg(Py_3_15)]
 use std::ffi::c_void;
 use std::ffi::{c_char, c_long};
-use std::ptr;
 
 use pyo3_ffi::*;
 
@@ -36,29 +35,26 @@ PyABIInfo_VAR!(ABI_INFO);
 
 const SLOTS_LEN: usize =
     1 + cfg!(Py_3_12) as usize + cfg!(Py_GIL_DISABLED) as usize + 4 * (cfg!(Py_3_15) as usize);
+#[cfg(Py_3_15)]
+static mut SLOTS: [PySlot; SLOTS_LEN] = [
+    PySlot_STATIC_DATA(Py_mod_abi, (&raw mut ABI_INFO).cast()),
+    // safety: Python does not write to these static fields
+    PySlot_STATIC_DATA(Py_mod_name, c"string_sum".as_ptr() as *mut c_void),
+    PySlot_STATIC_DATA(
+        Py_mod_doc,
+        c"A Python module written in Rust.".as_ptr() as *mut c_void,
+    ),
+    PySlot_STATIC_DATA(Py_mod_methods, (&raw mut METHODS).cast()),
+    PySlot_DATA(
+        Py_mod_multiple_interpreters,
+        Py_MOD_PER_INTERPRETER_GIL_SUPPORTED,
+    ),
+    #[cfg(Py_GIL_DISABLED)]
+    PySlot_DATA(Py_mod_gil, Py_MOD_GIL_NOT_USED),
+    PySlot_END(),
+];
+#[cfg(not(Py_3_15))]
 static mut SLOTS: [PyModuleDef_Slot; SLOTS_LEN] = [
-    #[cfg(Py_3_15)]
-    PyModuleDef_Slot {
-        slot: Py_mod_abi,
-        value: (&raw mut ABI_INFO).cast(),
-    },
-    #[cfg(Py_3_15)]
-    PyModuleDef_Slot {
-        slot: Py_mod_name,
-        // safety: Python does not write to this field
-        value: c"string_sum".as_ptr() as *mut c_void,
-    },
-    #[cfg(Py_3_15)]
-    PyModuleDef_Slot {
-        slot: Py_mod_doc,
-        // safety: Python does not write to this field
-        value: c"A Python module written in Rust.".as_ptr() as *mut c_void,
-    },
-    #[cfg(Py_3_15)]
-    PyModuleDef_Slot {
-        slot: Py_mod_methods,
-        value: (&raw mut METHODS).cast(),
-    },
     #[cfg(Py_3_12)]
     PyModuleDef_Slot {
         slot: Py_mod_multiple_interpreters,
@@ -71,7 +67,7 @@ static mut SLOTS: [PyModuleDef_Slot; SLOTS_LEN] = [
     },
     PyModuleDef_Slot {
         slot: 0,
-        value: ptr::null_mut(),
+        value: std::ptr::null_mut(),
     },
 ];
 

pyo3-ffi/src/cpython/critical_section.rs

@@ -1,38 +1,11 @@
-#[cfg(any(Py_3_14, Py_GIL_DISABLED))]
 use crate::PyMutex;
-use crate::PyObject;
-
-#[repr(C)]
-#[cfg(Py_GIL_DISABLED)]
-pub struct PyCriticalSection {
-    _cs_prev: usize,
-    _cs_mutex: *mut PyMutex,
-}
-
-#[repr(C)]
-#[cfg(Py_GIL_DISABLED)]
-pub struct PyCriticalSection2 {
-    _cs_base: PyCriticalSection,
-    _cs_mutex2: *mut PyMutex,
-}
-
-#[cfg(not(Py_GIL_DISABLED))]
-opaque_struct!(pub PyCriticalSection);
-
-#[cfg(not(Py_GIL_DISABLED))]
-opaque_struct!(pub PyCriticalSection2);
+use crate::{PyCriticalSection, PyCriticalSection2};
 
 extern_libpython! {
-    pub fn PyCriticalSection_Begin(c: *mut PyCriticalSection, op: *mut PyObject);
-    #[cfg(Py_3_14)]
     pub fn PyCriticalSection_BeginMutex(c: *mut PyCriticalSection, m: *mut PyMutex);
-    pub fn PyCriticalSection_End(c: *mut PyCriticalSection);
-    pub fn PyCriticalSection2_Begin(c: *mut PyCriticalSection2, a: *mut PyObject, b: *mut PyObject);
-    #[cfg(Py_3_14)]
     pub fn PyCriticalSection2_BeginMutex(
         c: *mut PyCriticalSection2,
         m1: *mut PyMutex,
         m2: *mut PyMutex,
     );
-    pub fn PyCriticalSection2_End(c: *mut PyCriticalSection2);
 }

pyo3-ffi/src/cpython/mod.rs

@@ -7,7 +7,7 @@ pub(crate) mod ceval;
 pub(crate) mod code;
 pub(crate) mod compile;
 pub(crate) mod complexobject;
-#[cfg(Py_3_13)]
+#[cfg(all(Py_3_14, Py_GIL_DISABLED))]
 pub(crate) mod critical_section;
 pub(crate) mod descrobject;
 pub(crate) mod dictobject;
@@ -56,8 +56,8 @@ pub use self::ceval::*;
 pub use self::code::*;
 pub use self::compile::*;
 pub use self::complexobject::*;
-#[cfg(Py_3_13)]
-pub use self::critical_section::*;
+#[cfg(all(Py_3_14, Py_GIL_DISABLED))]
+pub use self::critical_section::{PyCriticalSection2_BeginMutex, PyCriticalSection_BeginMutex};
 pub use self::descrobject::*;
 pub use self::dictobject::*;
 pub use self::floatobject::*;

pyo3-ffi/src/cpython/object.rs

@@ -6,6 +6,7 @@ use std::mem;
 // skipped private _Py_NewReference
 // skipped private _Py_NewReferenceNoTotal
 // skipped private _Py_ResurrectReference
+// skipped private _Py_ForgetReference
 
 // skipped private _Py_GetGlobalRefTotal
 // skipped private _Py_GetRefTotal
@@ -277,6 +278,8 @@ pub struct PyTypeObject {
     pub tp_next: *mut PyTypeObject,
     #[cfg(Py_3_13)]
     pub tp_versions_used: u16,
+    #[cfg(Py_3_15)]
+    pub _tp_iteritem: Option<object::_Py_iteritemfunc>,
 }
 
 #[cfg(Py_3_11)]

pyo3-ffi/src/critical_section.rs

@@ -0,0 +1,34 @@
+#[cfg(any(all(Py_GIL_DISABLED, Py_3_13, not(Py_LIMITED_API)), Py_3_15,))]
+use crate::PyMutex;
+#[cfg(any(all(Py_GIL_DISABLED, Py_3_13), Py_3_15))]
+use crate::PyObject;
+
+#[cfg(all(Py_LIMITED_API, Py_3_13, not(Py_3_15)))]
+opaque_struct!(pub PyMutex);
+
+#[cfg(any(all(Py_GIL_DISABLED, Py_3_13, not(Py_LIMITED_API)), Py_3_15,))]
+#[repr(C)]
+pub struct PyCriticalSection {
+    _cs_prev: usize,
+    _cs_mutex: *mut PyMutex,
+}
+
+#[cfg(any(all(Py_GIL_DISABLED, Py_3_13, not(Py_LIMITED_API)), Py_3_15,))]
+#[repr(C)]
+pub struct PyCriticalSection2 {
+    _cs_base: PyCriticalSection,
+    _cs_mutex2: *mut PyMutex,
+}
+
+#[cfg(all(not(Py_GIL_DISABLED), Py_3_13, not(Py_3_15), not(Py_LIMITED_API)))]
+opaque_struct!(pub PyCriticalSection);
+#[cfg(all(not(Py_GIL_DISABLED), Py_3_13, not(Py_3_15), not(Py_LIMITED_API)))]
+opaque_struct!(pub PyCriticalSection2);
+
+#[cfg(any(all(Py_GIL_DISABLED, Py_3_13), Py_3_15))]
+extern_libpython! {
+    pub fn PyCriticalSection_Begin(c: *mut PyCriticalSection, op: *mut PyObject);
+    pub fn PyCriticalSection_End(c: *mut PyCriticalSection);
+    pub fn PyCriticalSection2_Begin(c: *mut PyCriticalSection2, a: *mut PyObject, b: *mut PyObject);
+    pub fn PyCriticalSection2_End(c: *mut PyCriticalSection2);
+}