asymmetry for userdata vs attributes with ShadingSystemImpl::getattribute

[etheory]

Problem

In https://github.com/AcademySoftwareFoundation/OpenShadingLanguage/blob/bd7fd4cf8cd4b0b75c52715737b64b204bc585bf/src/liboslexec/shadingsys.cpp#L1927 we have:

• num_userdata
• userdata_names
• userdata_types
• userdata_offsets
• userdata_derivs

but only:

• num_attributes_needed
• attributes_needed
• attribute_scopes
• unknown_attributes_needed

which is missing a types, offsets and derivs for attributes.

This issue is to log the need for parity across these.

The mis-matching names are already a little bit confusing, so some kind of homogenization would also make sense.

Expected behavior:

I expect userdata and attributes to provide the same abilities for query during llvm compilation.

Actual behavior:

I don't have parity for userdata and attribute queries.

Steps to Reproduce

NA

Versions

• OSL branch/version: ALL
• OS: ALL
• C++ compiler: ALL
• LLVM version: ALL
• OIIO version: ALL

NOTE

I know this should be a PR, which I'll try and get to, but for the moment, I figured an issue would make sense.

Thanks!