gh-111178: fix UBSan failures in Objects/complexobject.c

[picnixz]

• Issue: UBSan: Calling a function through pointer to incorrect function type is undefined behavior #111178

[skirpichev]

I appreciate this cleanup, but, perhaps, you should change other type casts too. E.g. in the COMPLEX_BINOP macro.

[picnixz]

I wanted to keep a small diff but I can do that (as you can see, I've opened 20 PRs doing the same mechanical changes...)

[skirpichev]

If you do this mechanically (i.e. with sed), I would guess you should take some extra steps to prevent other changes in same file.

Perhaps, it's better to not introduce a new macro and stick with (PyComplexObject *) casts. Or change everything.

[picnixz]

When Victor and I started fixing #111178, we introduced a macro so that we can (in the future), possibly add type-checks easily. By "mechanical" changes, I manually changed everything (but everytime I repeated the same steps)

[skirpichev]

This structure modified a lot. Maybe it's an opportunity to change it to include only added entries in style:

static PyNumberMethods complex_as_number = {
    .nb_add = complex_add,
    .nb_subtract = complex_sub,
    .nb_multiply = complex_mul,
    .nb_power = complex_pow,
    [...]
};

[picnixz]

I wanted to do that as per #127679 but since Serhiy wanted a discussion first (#127679 (comment)) and since others wanted PEP-7 to be updated, I decided not to do that kind of cosmetic change (I admit that there are other cosmetic changes that I've done but those wouldn't cause conflicts or require a discussion IMO, they're just for consistency)

[skirpichev]

I see no discussion opened so far.

[picnixz]

Oh.. then.. maybe I can do the change? well.. I actually did it for internal structures, but for exported ones, I don't think I did it in any of the other PR. I'll ask on the issue.

[skirpichev]

I can do the change?

Well, discussion is not started so far. That's all:)

[encukou]

No need to expand the PR's scope. Feel free to send a follow-up PR.