bpo-39542: Make PyObject_INIT() opaque in limited C API (GH-18363)

In the limited C API, PyObject_INIT() and PyObject_INIT_VAR() are now
defined as aliases to PyObject_Init() and PyObject_InitVar() to make
their implementation opaque. It avoids to leak implementation details
in the limited C API.

Exclude the following functions from the limited C API, move them
from object.h to cpython/object.h:

* _Py_NewReference()
* _Py_ForgetReference()
* _PyTraceMalloc_NewReference()
* _Py_GetRefTotal()

1 files changed, 8 insertions, 4 deletions

diff --git a/Objects/object.c b/Objects/object.c
index 1884819b98..43b838adff 100644
--- a/Objects/object.c
+++ b/Objects/object.c
@@ -139,9 +139,11 @@ Py_DecRef(PyObject *o)
 PyObject *
 PyObject_Init(PyObject *op, PyTypeObject *tp)
 {
-    if (op == NULL)
+    /* Any changes should be reflected in PyObject_INIT() macro */
+    if (op == NULL) {
         return PyErr_NoMemory();
-    /* Any changes should be reflected in PyObject_INIT (objimpl.h) */
+    }
+
     Py_TYPE(op) = tp;
     if (PyType_GetFlags(tp) & Py_TPFLAGS_HEAPTYPE) {
         Py_INCREF(tp);
@@ -153,9 +155,11 @@ PyObject_Init(PyObject *op, PyTypeObject *tp)
 PyVarObject *
 PyObject_InitVar(PyVarObject *op, PyTypeObject *tp, Py_ssize_t size)
 {
-    if (op == NULL)
+    /* Any changes should be reflected in PyObject_INIT_VAR() macro */
+    if (op == NULL) {
         return (PyVarObject *) PyErr_NoMemory();
-    /* Any changes should be reflected in PyObject_INIT_VAR */
+    }
+
     Py_SIZE(op) = size;
     PyObject_Init((PyObject *)op, tp);
     return op;