1 files changed, 95 insertions, 0 deletions
diff --git a/contrib/tools/python3/Include/cpython/objimpl.h b/contrib/tools/python3/Include/cpython/objimpl.h
new file mode 100644
index 00000000000..5a8cdd57c78
--- /dev/null
+++ b/contrib/tools/python3/Include/cpython/objimpl.h
@@ -0,0 +1,95 @@
+#ifndef Py_CPYTHON_OBJIMPL_H
+#  error "this header file must not be included directly"
+#endif
+
+static inline size_t _PyObject_SIZE(PyTypeObject *type) {
+    return _Py_STATIC_CAST(size_t, type->tp_basicsize);
+}
+
+/* _PyObject_VAR_SIZE returns the number of bytes (as size_t) allocated for a
+   vrbl-size object with nitems items, exclusive of gc overhead (if any).  The
+   value is rounded up to the closest multiple of sizeof(void *), in order to
+   ensure that pointer fields at the end of the object are correctly aligned
+   for the platform (this is of special importance for subclasses of, e.g.,
+   str or int, so that pointers can be stored after the embedded data).
+
+   Note that there's no memory wastage in doing this, as malloc has to
+   return (at worst) pointer-aligned memory anyway.
+*/
+#if ((SIZEOF_VOID_P - 1) & SIZEOF_VOID_P) != 0
+#   error "_PyObject_VAR_SIZE requires SIZEOF_VOID_P be a power of 2"
+#endif
+
+static inline size_t _PyObject_VAR_SIZE(PyTypeObject *type, Py_ssize_t nitems) {
+    size_t size = _Py_STATIC_CAST(size_t, type->tp_basicsize);
+    size += _Py_STATIC_CAST(size_t, nitems) * _Py_STATIC_CAST(size_t, type->tp_itemsize);
+    return _Py_SIZE_ROUND_UP(size, SIZEOF_VOID_P);
+}
+
+
+/* This example code implements an object constructor with a custom
+   allocator, where PyObject_New is inlined, and shows the important
+   distinction between two steps (at least):
+       1) the actual allocation of the object storage;
+       2) the initialization of the Python specific fields
+      in this storage with PyObject_{Init, InitVar}.
+
+   PyObject *
+   YourObject_New(...)
+   {
+       PyObject *op;
+
+       op = (PyObject *) Your_Allocator(_PyObject_SIZE(YourTypeStruct));
+       if (op == NULL) {
+           return PyErr_NoMemory();
+       }
+
+       PyObject_Init(op, &YourTypeStruct);
+
+       op->ob_field = value;
+       ...
+       return op;
+   }
+
+   Note that in C++, the use of the new operator usually implies that
+   the 1st step is performed automatically for you, so in a C++ class
+   constructor you would start directly with PyObject_Init/InitVar. */
+
+
+typedef struct {
+    /* user context passed as the first argument to the 2 functions */
+    void *ctx;
+
+    /* allocate an arena of size bytes */
+    void* (*alloc) (void *ctx, size_t size);
+
+    /* free an arena */
+    void (*free) (void *ctx, void *ptr, size_t size);
+} PyObjectArenaAllocator;
+
+/* Get the arena allocator. */
+PyAPI_FUNC(void) PyObject_GetArenaAllocator(PyObjectArenaAllocator *allocator);
+
+/* Set the arena allocator. */
+PyAPI_FUNC(void) PyObject_SetArenaAllocator(PyObjectArenaAllocator *allocator);
+
+
+/* Test if an object implements the garbage collector protocol */
+PyAPI_FUNC(int) PyObject_IS_GC(PyObject *obj);
+
+
+/* Code built with Py_BUILD_CORE must include pycore_gc.h instead which
+   defines a different _PyGC_FINALIZED() macro. */
+#ifndef Py_BUILD_CORE
+   // Kept for backward compatibility with Python 3.8
+#  define _PyGC_FINALIZED(o) PyObject_GC_IsFinalized(o)
+#endif
+
+
+// Test if a type supports weak references
+PyAPI_FUNC(int) PyType_SUPPORTS_WEAKREFS(PyTypeObject *type);
+
+PyAPI_FUNC(PyObject **) PyObject_GET_WEAKREFS_LISTPTR(PyObject *op);
+
+PyAPI_FUNC(PyObject *) PyUnstable_Object_GC_NewWithExtraData(PyTypeObject *,
+                                                             size_t);