Although not specifically mentioned in the documentation, MSVC accepts __uuidof(…) and declspec(uuid("…")) attributes on enumeration types in addition to structs/classes. This is meaningful, as such types *do* have associated UUIDs in ActiveX typelibs, and such attributes are included by default in the wrappers generated by their #import construct, so they are not particularly unusual.
clang currently rejects the declspec with a –Wignored-attributes warning, and errors on uuidof() with “cannot call operator uuidof on a type with no GUID” (because it rejected the uuid attribute, and therefore finds no value). This is causing problems for us while trying to use clang-tidy on a codebase that makes heavy use of ActiveX.
I believe I have found the relevant places to add this functionality, this patch adds this case to clang’s implementation of these MS extensions.
patch is against r285994 (or actually the git mirror 80464680ce).
Both include an update to test/Parser/MicrosoftExtensions.cpp to exercise the new functionality.
This is my first time contributing to LLVM, so if I’ve missed anything else needed to prepare this for review just let me know!