[cfe-dev] Expansion of macro in VC++ preprocessor emulation

[Edward Diener via cfe-dev]

How can I show how clang is expanding a macro in the VC++ preprocessor 
emulation mode ?

Normally with a macro error clang shows, or has the ability to show, the 
macro expansion which leads to the error. But I am not seeing this when 
clang on Windows is targeting VC++ and trying to emulate the way that 
the non-standard VC++ preprocessor works.