gh-128863: Deprecate private C API functions (#128864)

Deprecate private C API functions:

* _PyBytes_Join()
* _PyDict_GetItemStringWithError()
* _PyDict_Pop()
* _PyThreadState_UncheckedGet()
* _PyUnicode_AsString()
* _Py_HashPointer()
* _Py_fopen_obj()

Replace _Py_HashPointer() with Py_HashPointer().

Remove references to deprecated functions.

Include/cpython/bytesobject.h

@@ -34,5 +34,9 @@ static inline Py_ssize_t PyBytes_GET_SIZE(PyObject *op) {
 
 PyAPI_FUNC(PyObject*) PyBytes_Join(PyObject *sep, PyObject *iterable);
 
-// Alias kept for backward compatibility
-#define _PyBytes_Join PyBytes_Join
+// Deprecated alias kept for backward compatibility
+Py_DEPRECATED(3.14) static inline PyObject*
+_PyBytes_Join(PyObject *sep, PyObject *iterable)
+{
+    return PyBytes_Join(sep, iterable);
+}

Include/cpython/dictobject.h

@@ -68,7 +68,12 @@ PyAPI_FUNC(PyObject *) _PyDict_NewPresized(Py_ssize_t minused);
 
 PyAPI_FUNC(int) PyDict_Pop(PyObject *dict, PyObject *key, PyObject **result);
 PyAPI_FUNC(int) PyDict_PopString(PyObject *dict, const char *key, PyObject **result);
-PyAPI_FUNC(PyObject *) _PyDict_Pop(PyObject *dict, PyObject *key, PyObject *default_value);
+
+// Use PyDict_Pop() instead
+Py_DEPRECATED(3.14) PyAPI_FUNC(PyObject *) _PyDict_Pop(
+    PyObject *dict,
+    PyObject *key,
+    PyObject *default_value);
 
 /* Dictionary watchers */
 

Include/cpython/fileutils.h

@@ -6,9 +6,11 @@ PyAPI_FUNC(FILE*) Py_fopen(
     PyObject *path,
     const char *mode);
 
-// Deprecated alias to Py_fopen() kept for backward compatibility
-Py_DEPRECATED(3.14) PyAPI_FUNC(FILE*) _Py_fopen_obj(
-    PyObject *path,
-    const char *mode);
+// Deprecated alias kept for backward compatibility
+Py_DEPRECATED(3.14) static inline FILE*
+_Py_fopen_obj(PyObject *path, const char *mode)
+{
+    return Py_fopen(path, mode);
+}
 
 PyAPI_FUNC(int) Py_fclose(FILE *file);

Include/cpython/pyhash.h

@@ -29,9 +29,6 @@
 /* Helpers for hash functions */
 PyAPI_FUNC(Py_hash_t) _Py_HashDouble(PyObject *, double);
 
-// Kept for backward compatibility
-#define _Py_HashPointer Py_HashPointer
-
 
 /* hash function definition */
 typedef struct {
@@ -44,6 +41,14 @@ typedef struct {
 PyAPI_FUNC(PyHash_FuncDef*) PyHash_GetFuncDef(void);
 
 PyAPI_FUNC(Py_hash_t) Py_HashPointer(const void *ptr);
+
+// Deprecated alias kept for backward compatibility
+Py_DEPRECATED(3.14) static inline Py_hash_t
+_Py_HashPointer(const void *ptr)
+{
+    return Py_HashPointer(ptr);
+}
+
 PyAPI_FUNC(Py_hash_t) PyObject_GenericHash(PyObject *);
 
 PyAPI_FUNC(Py_hash_t) Py_HashBuffer(const void *ptr, Py_ssize_t len);

Include/cpython/pystate.h

@@ -239,8 +239,12 @@ struct _ts {
  * if it is NULL. */
 PyAPI_FUNC(PyThreadState *) PyThreadState_GetUnchecked(void);
 
-// Alias kept for backward compatibility
-#define _PyThreadState_UncheckedGet PyThreadState_GetUnchecked
+// Deprecated alias kept for backward compatibility
+Py_DEPRECATED(3.14) static inline PyThreadState*
+_PyThreadState_UncheckedGet(void)
+{
+    return PyThreadState_GetUnchecked();
+}
 
 
 // Disable tracing and profiling.

Include/cpython/unicodeobject.h

@@ -630,8 +630,12 @@ _PyUnicodeWriter_Dealloc(_PyUnicodeWriter *writer);
 
 PyAPI_FUNC(const char *) PyUnicode_AsUTF8(PyObject *unicode);
 
-// Alias kept for backward compatibility
-#define _PyUnicode_AsString PyUnicode_AsUTF8
+// Deprecated alias kept for backward compatibility
+Py_DEPRECATED(3.14) static inline const char*
+_PyUnicode_AsString(PyObject *unicode)
+{
+    return PyUnicode_AsUTF8(unicode);
+}
 
 
 /* === Characters Type APIs =============================================== */