gh-102304: Fix Py_INCREF() stable ABI in debug mode

When Python is built in debug mode (if the Py_REF_DEBUG macro is
defined), the Py_INCREF() and Py_DECREF() function are now always
implemented as opaque functions to avoid leaking implementation
details like the "_Py_RefTotal" variable.

* Remove _Py_IncRefTotal_DO_NOT_USE_THIS() and
  _Py_DecRefTotal_DO_NOT_USE_THIS() from the stable ABI.
* Remove _Py_NegativeRefcount() from limited C API.
* Fix script name in Lib/test/test_stable_abi_ctypes.py

Author: vstinner

Include/object.h

@@ -585,20 +585,14 @@ decision that's up to the implementer of each new type so if you want,
 you can count such references to the type object.)
 */
 
-#ifdef Py_REF_DEBUG
-#  if defined(Py_LIMITED_API) && Py_LIMITED_API+0 < 0x030A0000
-extern Py_ssize_t _Py_RefTotal;
-#    define _Py_INC_REFTOTAL() _Py_RefTotal++
-#    define _Py_DEC_REFTOTAL() _Py_RefTotal--
-#  elif !defined(Py_LIMITED_API) || Py_LIMITED_API+0 >= 0x030C0000
+#if defined(Py_REF_DEBUG) && !defined(Py_LIMITED_API)
+PyAPI_FUNC(void) _Py_NegativeRefcount(const char *filename, int lineno,
+                                      PyObject *op);
 PyAPI_FUNC(void) _Py_IncRefTotal_DO_NOT_USE_THIS(void);
 PyAPI_FUNC(void) _Py_DecRefTotal_DO_NOT_USE_THIS(void);
 #    define _Py_INC_REFTOTAL() _Py_IncRefTotal_DO_NOT_USE_THIS()
 #    define _Py_DEC_REFTOTAL() _Py_DecRefTotal_DO_NOT_USE_THIS()
-#  endif
-PyAPI_FUNC(void) _Py_NegativeRefcount(const char *filename, int lineno,
-                                      PyObject *op);
-#endif /* Py_REF_DEBUG */
+#endif  // Py_REF_DEBUG && !Py_LIMITED_API
 
 PyAPI_FUNC(void) _Py_Dealloc(PyObject *);
 
@@ -616,8 +610,8 @@ PyAPI_FUNC(void) _Py_DecRef(PyObject *);
 
 static inline Py_ALWAYS_INLINE void Py_INCREF(PyObject *op)
 {
-#if defined(Py_REF_DEBUG) && defined(Py_LIMITED_API) && Py_LIMITED_API+0 >= 0x030A0000
-    // Stable ABI for Python 3.10 built in debug mode.
+#if defined(Py_REF_DEBUG) && defined(Py_LIMITED_API)
+    // Stable ABI for Python built in debug mode
     _Py_IncRef(op);
 #else
     // Non-limited C API and limited C API for Python 3.9 and older access
@@ -647,8 +641,8 @@ static inline Py_ALWAYS_INLINE void Py_INCREF(PyObject *op)
 #  define Py_INCREF(op) Py_INCREF(_PyObject_CAST(op))
 #endif
 
-#if defined(Py_REF_DEBUG) && defined(Py_LIMITED_API) && Py_LIMITED_API+0 >= 0x030A0000
-// Stable ABI for limited C API version 3.10 of Python debug build
+#if defined(Py_REF_DEBUG) && defined(Py_LIMITED_API)
+// Stable ABI for Python built in debug mode
 static inline void Py_DECREF(PyObject *op) {
     _Py_DecRef(op);
 }

Lib/test/test_stable_abi_ctypes.py

@@ -2729,6 +2729,10 @@ patchcheck: all
 
 .PHONY: check-limited-abi
 check-limited-abi: all
+	# Regenerate 3 files using using Tools/build/stable_abi.py:
+	# - Lib/test/test_stable_abi_ctypes.py
+	# - Modules/_testcapi_feature_macros.inc
+	# - PC/python3dll.c
 	$(RUNSHARED) ./$(BUILDPYTHON) $(srcdir)/Tools/build/stable_abi.py --all $(srcdir)/Misc/stable_abi.toml
 
 .PHONY: update-config

Makefile.pre.in

@@ -2409,12 +2409,3 @@
     added = '3.12'
 [const.Py_TPFLAGS_ITEMS_AT_END]
     added = '3.12'
-
-[function._Py_IncRefTotal_DO_NOT_USE_THIS]
-    added = '3.12'
-    ifdef = 'Py_REF_DEBUG'
-    abi_only = true
-[function._Py_DecRefTotal_DO_NOT_USE_THIS]
-    added = '3.12'
-    ifdef = 'Py_REF_DEBUG'
-    abi_only = true

Misc/stable_abi.toml

@@ -1,4 +1,4 @@
-// Generated by Tools/scripts/stable_abi.py
+// Generated by Tools/build/stable_abi.py
 
 // Add an entry in dict `result` for each Stable ABI feature macro.
 

Modules/_testcapi_feature_macros.inc

@@ -267,8 +267,8 @@ def gen_doc_annotations(manifest, args, outfile):
 def gen_ctypes_test(manifest, args, outfile):
     """Generate/check the ctypes-based test for exported symbols"""
     write = partial(print, file=outfile)
-    write(textwrap.dedent('''
-        # Generated by Tools/scripts/stable_abi.py
+    write(textwrap.dedent(f'''\
+        # Generated by {SCRIPT_NAME}
 
         """Test that all symbols of the Stable ABI are accessible using ctypes
         """
@@ -341,7 +341,7 @@ def test_windows_feature_macros(self):
 def gen_testcapi_feature_macros(manifest, args, outfile):
     """Generate/check the stable ABI list for documentation annotations"""
     write = partial(print, file=outfile)
-    write('// Generated by Tools/scripts/stable_abi.py')
+    write(f'// Generated by {SCRIPT_NAME}')
     write()
     write('// Add an entry in dict `result` for each Stable ABI feature macro.')
     write()