Completely get rid of PyClass and PyInstance.

(classobject.[ch] aren't empty yet because they also define PyMethod.)
This breaks lots of stuff, notably cPickle. But it's a step in the right
direction. I'll clean it up later.
(Also a few unrelated changes, e.g. T_NONE to define a "struct member"
that is always None, and simplification of __hash__ -- these are unfinished.)

Author: gvanrossum

Include/Python.h

@@ -7,14 +7,6 @@
 #include "patchlevel.h"
 #include "pyconfig.h"
 
-/* Cyclic gc is always enabled, starting with release 2.3a1.  Supply the
- * old symbol for the benefit of extension modules written before then
- * that may be conditionalizing on it.  The core doesn't use it anymore.
- */
-#ifndef WITH_CYCLE_GC
-#define WITH_CYCLE_GC 1
-#endif
-
 #include <limits.h>
 
 #ifndef UCHAR_MAX

Include/classobject.h

@@ -1,5 +1,4 @@
-
-/* Class object interface */
+/* Former class object interface -- now only (un)bound methods are here  */
 
 /* Revealing some structures (not for general use) */
 
@@ -9,24 +8,6 @@
 extern "C" {
 #endif
 
-typedef struct {
-    PyObject_HEAD
-    PyObject	*cl_bases;	/* A tuple of class objects */
-    PyObject	*cl_dict;	/* A dictionary */
-    PyObject	*cl_name;	/* A string */
-    /* The following three are functions or NULL */
-    PyObject	*cl_getattr;
-    PyObject	*cl_setattr;
-    PyObject	*cl_delattr;
-} PyClassObject;
-
-typedef struct {
-    PyObject_HEAD
-    PyClassObject *in_class;	/* The class object */
-    PyObject	  *in_dict;	/* A dictionary */
-    PyObject	  *in_weakreflist; /* List of weak references */
-} PyInstanceObject;
-
 typedef struct {
     PyObject_HEAD
     PyObject *im_func;   /* The callable object implementing the method */
@@ -35,34 +16,16 @@ typedef struct {
     PyObject *im_weakreflist; /* List of weak references */
 } PyMethodObject;
 
-PyAPI_DATA(PyTypeObject) PyClass_Type, PyInstance_Type, PyMethod_Type;
+PyAPI_DATA(PyTypeObject) PyMethod_Type;
 
-#define PyClass_Check(op) ((op)->ob_type == &PyClass_Type)
-#define PyInstance_Check(op) ((op)->ob_type == &PyInstance_Type)
 #define PyMethod_Check(op) ((op)->ob_type == &PyMethod_Type)
 
-PyAPI_FUNC(PyObject *) PyClass_New(PyObject *, PyObject *, PyObject *);
-PyAPI_FUNC(PyObject *) PyInstance_New(PyObject *, PyObject *,
-                                            PyObject *);
-PyAPI_FUNC(PyObject *) PyInstance_NewRaw(PyObject *, PyObject *);
 PyAPI_FUNC(PyObject *) PyMethod_New(PyObject *, PyObject *, PyObject *);
 
 PyAPI_FUNC(PyObject *) PyMethod_Function(PyObject *);
 PyAPI_FUNC(PyObject *) PyMethod_Self(PyObject *);
 PyAPI_FUNC(PyObject *) PyMethod_Class(PyObject *);
 
-/* Look up attribute with name (a string) on instance object pinst, using
- * only the instance and base class dicts.  If a descriptor is found in
- * a class dict, the descriptor is returned without calling it.
- * Returns NULL if nothing found, else a borrowed reference to the
- * value associated with name in the dict in which name was found.
- * The point of this routine is that it never calls arbitrary Python
- * code, so is always "safe":  all it does is dict lookups.  The function
- * can't fail, never sets an exception, and NULL is not an error (it just
- * means "not found").
- */
-PyAPI_FUNC(PyObject *) _PyInstance_Lookup(PyObject *pinst, PyObject *name);
-
 /* Macros for direct access to these values. Type checks are *not*
    done, so use with care. */
 #define PyMethod_GET_FUNCTION(meth) \
@@ -72,9 +35,6 @@ PyAPI_FUNC(PyObject *) _PyInstance_Lookup(PyObject *pinst, PyObject *name);
 #define PyMethod_GET_CLASS(meth) \
 	(((PyMethodObject *)meth) -> im_class)
 
-PyAPI_FUNC(int) PyClass_IsSubclass(PyObject *, PyObject *);
-
-
 #ifdef __cplusplus
 }
 #endif

Include/methodobject.h

@@ -63,7 +63,7 @@ PyAPI_FUNC(PyObject *) PyCFunction_NewEx(PyMethodDef *, PyObject *,
 #define METH_CLASS    0x0010
 #define METH_STATIC   0x0020
 
-/* METH_COEXIST allows a method to be entered eventhough a slot has
+/* METH_COEXIST allows a method to be entered even though a slot has
    already filled the entry.  When defined, the flag allows a separate
    method, "__contains__" for example, to coexist with a defined 
    slot like sq_contains. */

Include/object.h

@@ -147,7 +147,7 @@ typedef int (*visitproc)(PyObject *, void *);
 typedef int (*traverseproc)(PyObject *, visitproc, void *);
 
 typedef struct {
-	/* Number implementations should check *both*
+	/* Number implementations must check *both*
 	   arguments for proper type and implement the necessary conversions
 	   in the slot functions themselves. */
 
@@ -173,7 +173,7 @@ typedef struct {
 	unaryfunc nb_float;
 	unaryfunc nb_oct;
 	unaryfunc nb_hex;
-	/* Added in release 2.0 */
+
 	binaryfunc nb_inplace_add;
 	binaryfunc nb_inplace_subtract;
 	binaryfunc nb_inplace_multiply;
@@ -185,13 +185,11 @@ typedef struct {
 	binaryfunc nb_inplace_xor;
 	binaryfunc nb_inplace_or;
 
-	/* Added in release 2.2 */
 	binaryfunc nb_floor_divide;
 	binaryfunc nb_true_divide;
 	binaryfunc nb_inplace_floor_divide;
 	binaryfunc nb_inplace_true_divide;
 
-	/* Added in release 2.5 */
 	lenfunc nb_index;
 } PyNumberMethods;
 
@@ -204,7 +202,7 @@ typedef struct {
 	ssizeobjargproc sq_ass_item;
 	ssizessizeobjargproc sq_ass_slice;
 	objobjproc sq_contains;
-	/* Added in release 2.0 */
+
 	binaryfunc sq_inplace_concat;
 	ssizeargfunc sq_inplace_repeat;
 } PySequenceMethods;
@@ -292,7 +290,6 @@ typedef struct _typeobject {
 	/* weak reference enabler */
 	Py_ssize_t tp_weaklistoffset;
 
-	/* Added in release 2.2 */
 	/* Iterators */
 	getiterfunc tp_iter;
 	iternextfunc tp_iternext;

Include/structmember.h

@@ -67,9 +67,11 @@ typedef struct PyMemberDef {
 				   converting to None. */
 #ifdef HAVE_LONG_LONG
 #define T_LONGLONG      17  
-#define T_ULONGLONG      18
+#define T_ULONGLONG     18
 #endif /* HAVE_LONG_LONG */
 
+#define T_NONE          19      /* Value is always None */
+
 /* Flags */
 #define READONLY	1
 #define RO		READONLY		/* Shorthand */

Modules/_sre.c

@@ -3363,19 +3363,19 @@ static PyMethodDef _functions[] = {
     {NULL, NULL}
 };
 
-#if PY_VERSION_HEX < 0x02030000
-DL_EXPORT(void) init_sre(void)
-#else
 PyMODINIT_FUNC init_sre(void)
-#endif
 {
     PyObject* m;
     PyObject* d;
     PyObject* x;
 
-    /* Patch object types */
-    Pattern_Type.ob_type = Match_Type.ob_type =
-        Scanner_Type.ob_type = &PyType_Type;
+    /* Initialize object types */
+    if (PyType_Ready(&Pattern_Type) < 0)
+        return;
+    if (PyType_Ready(&Match_Type) < 0)
+        return;
+    if (PyType_Ready(&Scanner_Type) < 0)
+        return;
 
     m = Py_InitModule("_" SRE_MODULE, _functions);
     if (m == NULL)

Modules/arraymodule.c

@@ -2112,7 +2112,8 @@ initarray(void)
 {
 	PyObject *m;
 
-	Arraytype.ob_type = &PyType_Type;
+	if (PyType_Ready(&Arraytype) < 0)
+            return;
 	PyArrayIter_Type.ob_type = &PyType_Type;
 	m = Py_InitModule3("array", a_methods, module_doc);
 	if (m == NULL)