Push correct enclosing class while deferring a method

[ilevkivskyi]

Fixes #4069

This pushes the correct enclosing class while deferring a method instead of just the top class.

A related comment: the name active_class is a bit misleading, it returns None from within methods, I think it would be more consistent if active_class behave the same way as self.type in semantic analysis, but it is too late to change this, it is already used in several other places with this semantics.

[elazarg]

I think I am to blame for the name active_class, and I agree it's not the best. But the intention is that active is active scope, and inside a method there is no active class scope. I don't think it's the same as "the current type".

Can't the issue be resolved by freezing the entire scope, as suggested by the TODO?

Anyway, if you are leaving the method active_class(), and assigning enclosing_scope() to a variable, I think it can't be called active_class; it will be confusing.

[ilevkivskyi]

Can't the issue be resolved by freezing the entire scope, as suggested by the TODO?

It is unnecessary, and will only make solution more complex.

Anyway, if you are leaving the method active_class(), and assigning enclosing_scope() to a variable, I think it can't be called active_class; it will be confusing.

OK, I renamed this variable, I keep however the named tuple attribute name, active_typeinfo, it makes sense, since the enclosing class for a method becomes the active class when the deferred node rechecking starts.

[JukkaL]

Can you fix the merge conflict?

[ilevkivskyi]

@JukkaL

Can you fix the merge conflict?

Fixed.

[JukkaL]

This generates unexpected errors when run against an internal Dropbox codebase. Here is a simplified example:

class A:
    def f(self) -> None:
        def g(x: int) -> int:  # Self argument missing for a non-static method 
                               # (or an invalid type for self)
            return y

y = int()

[ilevkivskyi]

This generates unexpected errors when run against an internal Dropbox codebase. Here is a simplified example: ...

Indeed, since the active_typeinfo is only used by bind_self and friends, we should only push the immediate enclosing class. Will push a fix in a second.

[ilevkivskyi]

@JukkaL Fixed.

[JukkaL]

LGTM, thanks for the PR!