bpo-39542: Simplify _Py_NewReference() (GH-18332)

* Remove _Py_INC_REFTOTAL and _Py_DEC_REFTOTAL macros: modify
  directly _Py_RefTotal.
* _Py_ForgetReference() is no longer defined if the Py_TRACE_REFS
  macro is not defined.
* Remove _Py_NewReference() implementation from object.c:
  unify the two implementations in object.h inline function.
* Fix Py_TRACE_REFS build: _Py_INC_TPALLOCS() macro has been removed.

1 files changed, 15 insertions, 27 deletions

diff --git a/Include/object.h b/Include/object.h
index e1cc47a..175a208 100644
--- a/Include/object.h
+++ b/Include/object.h
@@ -379,25 +379,11 @@ decision that's up to the implementer of each new type so if you want,
 you can count such references to the type object.)
 */
 
-/* First define a pile of simple helper macros, one set per special
- * build symbol.  These either expand to the obvious things, or to
- * nothing at all when the special mode isn't in effect.  The main
- * macros can later be defined just once then, yet expand to different
- * things depending on which special build options are and aren't in effect.
- * Trust me <wink>:  while painful, this is 20x easier to understand than,
- * e.g, defining _Py_NewReference five different times in a maze of nested
- * #ifdefs (we used to do that -- it was impenetrable).
- */
 #ifdef Py_REF_DEBUG
 PyAPI_DATA(Py_ssize_t) _Py_RefTotal;
 PyAPI_FUNC(void) _Py_NegativeRefcount(const char *filename, int lineno,
                                       PyObject *op);
 PyAPI_FUNC(Py_ssize_t) _Py_GetRefTotal(void);
-#define _Py_INC_REFTOTAL        _Py_RefTotal++
-#define _Py_DEC_REFTOTAL        _Py_RefTotal--
-#else
-#define _Py_INC_REFTOTAL
-#define _Py_DEC_REFTOTAL
 #endif /* Py_REF_DEBUG */
 
 /* Update the Python traceback of an object. This function must be called
@@ -406,33 +392,33 @@ PyAPI_FUNC(int) _PyTraceMalloc_NewReference(PyObject *op);
 
 #ifdef Py_TRACE_REFS
 /* Py_TRACE_REFS is such major surgery that we call external routines. */
-PyAPI_FUNC(void) _Py_NewReference(PyObject *);
 PyAPI_FUNC(void) _Py_ForgetReference(PyObject *);
 PyAPI_FUNC(void) _Py_AddToAllObjects(PyObject *, int force);
-#else
-/* Without Py_TRACE_REFS, there's little enough to do that we expand code
-   inline. */
+#endif
+
+
 static inline void _Py_NewReference(PyObject *op)
 {
     if (_Py_tracemalloc_config.tracing) {
         _PyTraceMalloc_NewReference(op);
     }
-    _Py_INC_REFTOTAL;
+#ifdef Py_REF_DEBUG
+    _Py_RefTotal++;
+#endif
     Py_REFCNT(op) = 1;
+#ifdef Py_TRACE_REFS
+    _Py_AddToAllObjects(op, 1);
+#endif
 }
 
-static inline void _Py_ForgetReference(PyObject *Py_UNUSED(op))
-{
-    /* nothing to do */
-}
-#endif /* !Py_TRACE_REFS */
-
 
 PyAPI_FUNC(void) _Py_Dealloc(PyObject *);
 
 static inline void _Py_INCREF(PyObject *op)
 {
-    _Py_INC_REFTOTAL;
+#ifdef Py_REF_DEBUG
+    _Py_RefTotal++;
+#endif
     op->ob_refcnt++;
 }
 
@@ -444,7 +430,9 @@ static inline void _Py_DECREF(
 #endif
     PyObject *op)
 {
-    _Py_DEC_REFTOTAL;
+#ifdef Py_REF_DEBUG
+    _Py_RefTotal--;
+#endif
     if (--op->ob_refcnt != 0) {
 #ifdef Py_REF_DEBUG
         if (op->ob_refcnt < 0) {