[Python-Dev] Why is type_modified() in typeobject.c not a public function?

[Stefan Behnel]

Hi,

Guido van Rossum wrote:
> On Tue, May 27, 2008 at 9:47 AM, Stefan Behnel <stefan_ml at behnel.de> wrote:
>> Could this function get a public interface? I do not think Cython is the only
>> case where C code wants to modify a type after its creation, and copying the
>> code over seems like a hack to me.
>>
> I'm fine with giving it a public interface. Please submit a patch with
> docs included.

Straight forward patch is attached (against 3.0a5). Works for me in Cython. I
thought about a name like "Taint(t)" or "ClearTypeCache(t)", but then went
with the coward solution of calling the function PyType_Modified() as it was
(almost) named internally.

BTW, I noticed that the code in typeobject.c uses "DECREF before set" two
times, like this:

		method_cache[h].version = type->tp_version_tag;
		method_cache[h].value = res;  /* borrowed */
		Py_INCREF(name);
		Py_DECREF(method_cache[h].name);
		method_cache[h].name = name;

During the call to Py_DECREF, the cache content is incorrect, so can't this
run into the same problem that Py_CLEAR() aims to solve? I attached a patch
for that, too, just in case.

Stefan


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