MAINT: Fix METH_NOARGS function signatures

[hoodmane]

This is a continuation of @joemarshall's work #19058.

I think there should be a bunch of more issues around METH_NOARGS usage that would be nice to fix up as well.
@seberg in #19058 (comment)

This fixes all of the incorrect METH_NOARGS signatures that I managed to track down.
We need this for pyodide/pyodide#1677.

[seberg]

Thanks! Would you be up to making it throughout NPY_UNUSED(args)? Since I think it is a bit more clear what this is. One (or two) of them are also a bit long lines, we try to stay under 80 characters.

But changes look good, just thought a bit more uniform naming will be easier to understand.

[hoodmane]

I don't understand the failing doctests.

[hoodmane]

Also, if you want me to clean the history I am happy to rebase and squash all the commits.

[seberg]

We can just squash-merge, curious what is "closure"? (I think I just come form a different angle, I thought "args", because most python functions get args or arg passed in, but here it is always NULL.)

No need to squash, if you don't we will probably just squash-merge.

[hoodmane]

I think args is sort of the right name for the extra argument of the METH_NOARGS functions. But the argument really doesn't mean anything: it just gets filled in with NULL here:
https://github.com/python/cpython/blob/fc4474e45eecbea8e88095f28c98c5d56438d841/Objects/methodobject.c#L489
I am not really sure why they put that in, it just seems to cause trouble.

The void * argument to getters and setters I think should best be called void *closure.

See here: https://docs.python.org/3/c-api/structures.html?highlight=getset#c.PyGetSetDef

void *closure -- optional function pointer, providing additional data for getter and setter

In the CPython source, sometimes the extra noargs arguments are called args (13 times) but much more often they are called ignored (780 times).

The last argument to getters and setters is variously called closure, context, or ignored in CPython source.

This is more than you wanted to know I'm sure =)

[seberg]

I am not really sure why they put that in, it just seems to cause trouble.

Well, could be to save some branching. Or just historical, maybe METH_NORARG was added later for convenience...

This is more than you wanted to know I'm sure =)

Hehehe, thanks :). I was just confused why closure has any meaning in this context (but it is also a term I am simply not really used to).

Anyway, thanks! Let me put this in, before I find something else to nitpick about ;).

[seberg]

Marking as backport candidate, since it is harmless and you mentioned you need it for pyodine, so presumably it would be nice to have a released version with it in.

[hoodmane]

Thanks!

[charris]

The circleci failures are legitimate.

[charris]

But I don't see exactly how the CircleCI failure is related to this.

[seberg]

Hmmm, and only on this PR! Very strange...

[charris]

Also in the backport.

[hoodmane]

After the most recent commit, these tests are passing on main again. At a glance it is very unclear why the most recent commit would have any effect on these tests either.