patch 9.0.2036: if_python: rework python3.12 build dependency

Problem:  if_python: rework python3.12 build dependency
          (after 9.0.1996)
Solution: use PyTuple_Size instead of inlining the Py_SIZE
          into the Vim code base

Use a simpler fix for Python 3.12 build issues

Python 3.12 introduced link dependencies to their `Py_SIZE()` inline
function, which #13290 fixed by copying the inline function to Vim's
Python binding code. This works but it's fragile, as a future update may
change the implementation of `Py_SIZE` and there is no way for us to
know.

The reason we need `Py_SIZE` to begin with is that we use
`PyTuple_GET_SIZE()` which calls that. Just fix it by mapping that to
(confusingly similarly named) `PyTuple_Size()`, which we already do in
the stable ABI implementation. There's a minor performance cost in that
it's not inlined and it does error checking but that's fine as we only
call this function rarely (in an error handler).

related: #13290
closes: #13359

Signed-off-by: Christian Brabandt <[email protected]>
Co-authored-by: Yee Cheng Chin <[email protected]>

Author: ychin

src/if_python3.c

@@ -299,9 +299,6 @@ static HINSTANCE hinstPy3 = 0; // Instance of python.dll
 # define PyNumber_Check (*py3_PyNumber_Check)
 # define PyNumber_Long (*py3_PyNumber_Long)
 # define PyBool_Type (*py3_PyBool_Type)
-# if PY_VERSION_HEX >= 0x030c00b0
-#  define PyLong_Type (*py3_PyLong_Type)
-# endif
 # define PyErr_NewException py3_PyErr_NewException
 # ifdef Py_DEBUG
 #  define _Py_NegativeRefcount py3__Py_NegativeRefcount
@@ -501,9 +498,6 @@ static PyTypeObject* py3_PyStdPrinter_Type;
 static PyTypeObject* py3_PySlice_Type;
 static PyTypeObject* py3_PyFloat_Type;
 static PyTypeObject* py3_PyBool_Type;
-# if PY_VERSION_HEX >= 0x030c00b0
-static PyTypeObject* py3_PyLong_Type;
-# endif
 static int (*py3_PyNumber_Check)(PyObject *);
 static PyObject* (*py3_PyNumber_Long)(PyObject *);
 static PyObject* (*py3_PyErr_NewException)(char *name, PyObject *base, PyObject *dict);
@@ -701,9 +695,6 @@ static struct
     {"PySlice_Type", (PYTHON_PROC*)&py3_PySlice_Type},
     {"PyFloat_Type", (PYTHON_PROC*)&py3_PyFloat_Type},
     {"PyBool_Type", (PYTHON_PROC*)&py3_PyBool_Type},
-# if PY_VERSION_HEX >= 0x030c00b0
-    {"PyLong_Type", (PYTHON_PROC*)&py3_PyLong_Type},
-# endif
     {"PyNumber_Check", (PYTHON_PROC*)&py3_PyNumber_Check},
     {"PyNumber_Long", (PYTHON_PROC*)&py3_PyNumber_Long},
     {"PyErr_NewException", (PYTHON_PROC*)&py3_PyErr_NewException},
@@ -795,39 +786,14 @@ py3__PyObject_TypeCheck(PyObject *ob, PyTypeObject *type)
 # endif
 
 # if !defined(USE_LIMITED_API) && PY_VERSION_HEX >= 0x030c00b0
-// Py_SIZE() uses PyLong_Type and PyBool_Type starting from Python 3.12.
-// We need to define our own Py_SIZE() to replace Py{Bool,Long}_Type with
-// py3_Py{Bool,Long}_Type.
-// We also need to redefine PyTuple_GET_SIZE() and PyList_GET_SIZE(), because
-// they use Py_SIZE().
-    static inline Py_ssize_t
-py3_Py_SIZE(PyObject *ob)
-{
-    assert(ob->ob_type != &PyLong_Type);
-    assert(ob->ob_type != &PyBool_Type);
-    PyVarObject *var_ob = _PyVarObject_CAST(ob);
-    return var_ob->ob_size;
-}
-#  undef Py_SIZE
-#  define Py_SIZE(ob) py3_Py_SIZE(_PyObject_CAST(ob))
-
-    static inline Py_ssize_t
-py3_PyTuple_GET_SIZE(PyObject *op)
-{
-    PyTupleObject *tuple = _PyTuple_CAST(op);
-    return Py_SIZE(tuple);
-}
+// PyTuple_GET_SIZE/PyList_GET_SIZE are inlined functions that use Py_SIZE(),
+// which started to introduce linkage dependency from Python 3.12. When we
+// build Python in dynamic mode, we don't link against it in build time, and
+// this would fail to build. Just use the non-inlined version instead.
 #  undef PyTuple_GET_SIZE
-#  define PyTuple_GET_SIZE(op) py3_PyTuple_GET_SIZE(_PyObject_CAST(op))
-
-    static inline
-Py_ssize_t py3_PyList_GET_SIZE(PyObject *op)
-{
-    PyListObject *list = _PyList_CAST(op);
-    return Py_SIZE(list);
-}
+#  define PyTuple_GET_SIZE(o) PyTuple_Size(o)
 #  undef PyList_GET_SIZE
-#  define PyList_GET_SIZE(op) py3_PyList_GET_SIZE(_PyObject_CAST(op))
+#  define PyList_GET_SIZE(o) PyList_Size(o)
 # endif
 
 # ifdef MSWIN

src/version.c

@@ -704,6 +704,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    2036,
 /**/
     2035,
 /**/