gh-111178: fix UBSan failures in `Modules/posixmodule.c` by picnixz · Pull Request #129788 · python/cpython

There was a redundant cast that I missed. I also renamed some parameters that I incorrectly renamed (using Py_UNUSED(ignored) is useless, it doesn't tell you at first glance whether it's a NOARGS or a ONEARG/VARARGS method while Py_UNUSED(dummy), Py_UNUSED(arg) and Py_UNUSED(args) would tell you more).

using Py_UNUSED(ignored) is useless, it doesn't tell you at first glance whether it's a NOARGS or a ONEARG/VARARGS method while Py_UNUSED(dummy), Py_UNUSED(arg) and Py_UNUSED(args) would tell you more

FWIW, I'm skeptical here -- I don't think we can make it reliably tell you more. But, if it doesn't matter, why not use your suggestions.

don't think we can make it reliably tell you more

The thing is that I saw one usage of void *ignored although it should have been PyObject *unused (#130446), however this was hidden behind a #ifdef MS_WINDOWS and removing the PyCFunction cast introduced a compilation error that I didn't see. For me "ignored" or "unused" means that we can possibly use the argument later. However "dummy" really means for me "it's just a placeholder, we'll never use it later" (I'm only using dummy for NOARGS method, not for VARARGS that actually ignore their args value).

The semantic change I usually do is unused to closure because the closure parameter is generally really for getter/setter and not for methods.