add Py_HashBuffer to pyo3-ffi (PyO3#5086)

* add `Py_HashBuffer` to `pyo3-ffi`

* Add `Py_HashBuffer` binding when 3.14+

* Move to `cpython/pyhash.rs`

* Update changelog

* Enable`Py_HashBuffer` compat on 3.14 abi3

Author: bschoenmaeckers

newsfragments/5086.added.md

@@ -0,0 +1,3 @@
+- add `Py_HashBuffer` to `pyo3-ffi`
+- add `Py_HashPointer` to `pyo3-ffi`
+- add `PyObject_GenericHash` to `pyo3-ffi`

pyo3-ffi/src/compat/mod.rs

@@ -52,8 +52,10 @@ macro_rules! compat_function {
 
 mod py_3_10;
 mod py_3_13;
+mod py_3_14;
 mod py_3_9;
 
 pub use self::py_3_10::*;
 pub use self::py_3_13::*;
+pub use self::py_3_14::*;
 pub use self::py_3_9::*;

pyo3-ffi/src/compat/py_3_14.rs

@@ -0,0 +1,26 @@
+compat_function!(
+    originally_defined_for(all(Py_3_14, not(Py_LIMITED_API)));
+
+    #[inline]
+    pub unsafe fn Py_HashBuffer(
+        ptr: *const std::ffi::c_void,
+        len: crate::Py_ssize_t,
+    ) -> crate::Py_hash_t {
+        #[cfg(not(any(Py_LIMITED_API, PyPy)))]
+        {
+            crate::_Py_HashBytes(ptr, len)
+        }
+
+        #[cfg(any(Py_LIMITED_API, PyPy))]
+        {
+            let bytes = crate::PyBytes_FromStringAndSize(ptr as *const std::os::raw::c_char, len);
+            if bytes.is_null() {
+                -1
+            } else {
+                let result = crate::PyObject_Hash(bytes);
+                crate::Py_DECREF(bytes);
+                result
+            }
+        }
+    }
+);

pyo3-ffi/src/cpython/mod.rs

@@ -38,6 +38,7 @@ pub(crate) mod pythonrun;
 // skipped sysmodule.h
 pub(crate) mod floatobject;
 pub(crate) mod pyframe;
+pub(crate) mod pyhash;
 pub(crate) mod tupleobject;
 pub(crate) mod unicodeobject;
 pub(crate) mod weakrefobject;
@@ -73,6 +74,7 @@ pub use self::pydebug::*;
 pub use self::pyerrors::*;
 #[cfg(all(Py_3_11, not(PyPy)))]
 pub use self::pyframe::*;
+pub use self::pyhash::*;
 #[cfg(all(Py_3_8, not(PyPy)))]
 pub use self::pylifecycle::*;
 pub use self::pymem::*;

pyo3-ffi/src/cpython/pyhash.rs

@@ -0,0 +1,30 @@
+#[cfg(Py_3_13)]
+use crate::PyObject;
+use crate::{Py_hash_t, Py_ssize_t};
+use std::os::raw::{c_char, c_int, c_void};
+
+#[repr(C)]
+#[derive(Copy, Clone)]
+pub struct PyHash_FuncDef {
+    pub hash: Option<extern "C" fn(arg1: *const c_void, arg2: Py_ssize_t) -> Py_hash_t>,
+    pub name: *const c_char,
+    pub hash_bits: c_int,
+    pub seed_bits: c_int,
+}
+
+impl Default for PyHash_FuncDef {
+    #[inline]
+    fn default() -> Self {
+        unsafe { std::mem::zeroed() }
+    }
+}
+
+extern "C" {
+    pub fn PyHash_GetFuncDef() -> *mut PyHash_FuncDef;
+    #[cfg(Py_3_13)]
+    pub fn Py_HashPointer(ptr: *const c_void) -> Py_hash_t;
+    #[cfg(Py_3_13)]
+    pub fn PyObject_GenericHash(obj: *mut PyObject) -> Py_hash_t;
+    #[cfg(Py_3_14)]
+    pub fn Py_HashBuffer(ptr: *const c_void, len: Py_ssize_t) -> Py_hash_t;
+}

pyo3-ffi/src/pyhash.rs

@@ -1,7 +1,5 @@
 #[cfg(not(any(Py_LIMITED_API, PyPy)))]
 use crate::pyport::{Py_hash_t, Py_ssize_t};
-#[cfg(not(any(Py_LIMITED_API, PyPy, GraalPy)))]
-use std::os::raw::c_char;
 #[cfg(not(any(Py_LIMITED_API, PyPy)))]
 use std::os::raw::c_void;
 
@@ -22,29 +20,6 @@ pub const _PyHASH_MULTIPLIER: c_ulong = 1000003;
 
 // skipped non-limited _Py_HashSecret_t
 
-#[cfg(not(any(Py_LIMITED_API, PyPy, GraalPy)))]
-#[repr(C)]
-#[derive(Copy, Clone)]
-pub struct PyHash_FuncDef {
-    pub hash: Option<extern "C" fn(arg1: *const c_void, arg2: Py_ssize_t) -> Py_hash_t>,
-    pub name: *const c_char,
-    pub hash_bits: c_int,
-    pub seed_bits: c_int,
-}
-
-#[cfg(not(any(Py_LIMITED_API, PyPy, GraalPy)))]
-impl Default for PyHash_FuncDef {
-    #[inline]
-    fn default() -> Self {
-        unsafe { std::mem::zeroed() }
-    }
-}
-
-extern "C" {
-    #[cfg(not(any(Py_LIMITED_API, PyPy, GraalPy)))]
-    pub fn PyHash_GetFuncDef() -> *mut PyHash_FuncDef;
-}
-
 // skipped Py_HASH_CUTOFF
 
 pub const Py_HASH_EXTERNAL: c_int = 0;