It's mostly about WXDLLEXPORT, WXDLLIMPEXP, WXDLLIMPEXP_SCI, and WXDLLIMPEXP_PG.
I have no idea what we need them for, anyway (or if at all?). Since we don't do any dynamic loading, I think those should be not needed at all? The linker should figure out a symbol if it's not exported, too... shouldn't it?
Anyway, that's what triggers the "attribute blah blah cannot blah" style error.