Add support for PyFrozenDict

[MatthieuDartiailh]

No description provided.

[MatthieuDartiailh]

I am a bit at a loss when it comes to the ffi checks. Pointers welcome

[alex]

AFAIK the header that contains this in CPython is Include/internal/pycore_dict.h, so you'd need to include that path.

(Not opining on any part of this patch.)

[MatthieuDartiailh]

Thanks I will try that.

[MatthieuDartiailh]

So the ffi-check situtation is a bit more complex since accessing the core headers requires Py_BUILD_CORE define. Is this something pyo3 maintainers would be willing to accept ?

[Icxolu]

I'm also not an expert on the FFI layer, but here are some comment from my side.

(I haven't looked at the wrapping code, as we first need to get the FFI bindings correct.)

[Icxolu]

This is not defined in cpython/dictobject.h, so we should not add it here. I also don't see that we need this for anything, so I would suggest to just drop it entirely for now, which also removes the need to include internal headers in the ffi check.

[Icxolu]

This and all the following are defined in cpython/dictobject.h, so they need to be moved to cpython/dictobject.rs here as well.

[davidhewitt]

So the ffi-check situtation is a bit more complex since accessing the core headers requires Py_BUILD_CORE define. Is this something pyo3 maintainers would be willing to accept ?

We should not be using any symbols from Include/internal.