[Python-checkins] python/dist/src/Objects typeobject.c,2.126.4.35,2.126.4.36

[tim_one@users.sourceforge.net]

Update of /cvsroot/python/python/dist/src/Objects
In directory sc8-pr-cvs1:/tmp/cvs-serv23341/Objects

Modified Files:
      Tag: release22-maint
	typeobject.c 
Log Message:
PyType_Ready():  Complain if the type is a base type, and gc'able, and
tp_free is NULL or PyObject_Del at the end.  Because it's a base type
it must call tp_free in its dealloc function, and because it's gc'able
it must not call PyObject_Del.

inherit_slots():  Don't inherit tp_free unless the type and its base
agree about whether they're gc'able.  If the type is gc'able and the
base is not, and the base uses the default PyObject_Del for its
tp_free, give the type PyObject_GC_Del for its tp_free (the appropriate
default for a gc'able type).

cPickle.c:  The Pickler and Unpickler types claim to be base classes
and gc'able, but their dealloc functions didn't call tp_free.
Repaired that.  Also call PyType_Ready() on these typeobjects, so
that the correct (PyObject_GC_Del) default memory-freeing function
gets plugged into these types' tp_free slots.


Index: typeobject.c
===================================================================
RCS file: /cvsroot/python/python/dist/src/Objects/typeobject.c,v
retrieving revision 2.126.4.35
retrieving revision 2.126.4.36
diff -C2 -d -r2.126.4.35 -r2.126.4.36
*** typeobject.c	20 May 2003 02:42:04 -0000	2.126.4.35
--- typeobject.c	21 May 2003 20:43:10 -0000	2.126.4.36
***************
*** 2093,2098 ****
  		COPYSLOT(tp_init);
  		COPYSLOT(tp_alloc);
- 		COPYSLOT(tp_free);
  		COPYSLOT(tp_is_gc);
  	}
  }
--- 2093,2115 ----
  		COPYSLOT(tp_init);
  		COPYSLOT(tp_alloc);
  		COPYSLOT(tp_is_gc);
+ 		if ((type->tp_flags & Py_TPFLAGS_HAVE_GC) ==
+ 		    (base->tp_flags & Py_TPFLAGS_HAVE_GC)) {
+ 			/* They agree about gc. */
+ 			COPYSLOT(tp_free);
+ 		}
+ 		else if ((type->tp_flags & Py_TPFLAGS_HAVE_GC) &&
+ 			 type->tp_free == NULL &&
+ 			 base->tp_free == _PyObject_Del) {
+ 			/* A bit of magic to plug in the correct default
+ 			 * tp_free function when a derived class adds gc,
+ 			 * didn't define tp_free, and the base uses the
+ 			 * default non-gc tp_free.
+ 			 */
+ 			type->tp_free = _PyObject_GC_Del;
+ 		}
+ 		/* else they didn't agree about gc, and there isn't something
+ 		 * obvious to be done -- the type is on its own.
+ 		 */
  	}
  }
***************
*** 2190,2193 ****
--- 2207,2223 ----
  	}
  
+ 	/* Sanity check for tp_free. */
+ 	if (PyType_IS_GC(type) && (type->tp_flags & Py_TPFLAGS_BASETYPE) &&
+ 	    (type->tp_free == NULL || type->tp_free == _PyObject_Del)) {
+ 	    	/* This base class needs to call tp_free, but doesn't have
+ 	    	 * one, or its tp_free is for non-gc'ed objects.
+ 	    	 */
+ 		PyErr_Format(PyExc_TypeError, "type '%.100s' participates in "
+ 			     "gc and is a base type but has inappropriate "
+ 			     "tp_free slot",
+ 			     type->tp_name);
+ 		goto error;
+ 	}
+ 
  	/* if the type dictionary doesn't contain a __doc__, set it from
  	   the tp_doc slot.
***************
*** 2749,2753 ****
  	return Py_None;
  }
!   
  static PyObject *
  wrap_descr_delete(PyObject *self, PyObject *args, void *wrapped)
--- 2779,2783 ----
  	return Py_None;
  }
! 
  static PyObject *
  wrap_descr_delete(PyObject *self, PyObject *args, void *wrapped)