VerifyDiagnosticConsumer and ModuleMapParser

[Vassil Vassilev]

Hi guys,
   I am working on http://llvm.org/bugs/show_bug.cgi?id=20507 Now the 
diagnostic gets issued for:
     Clang :: Modules/declare-use1.cpp
     Clang :: Modules/declare-use2.cpp
     Clang :: Modules/declare-use3.cpp
     Clang :: Modules/strict-decluse.cpp

It says smth like: Modules/Inputs/declare-use/module.map:30:10: note: 
Header file 'unavailable.h' not present in module 'XF'

I'd like to add an expected diag to the modulemap file. Eg:
module XF {
   ...
   header "unavailable.h" // expected-note {{...}}
   ...
}

Is that the right way to go?

If yes, VerifyDiagnosticConsumer requires some callbacks (such as 
HandleComment) which come from the Preprocessor. In the ModuleMapParser 
we use raw lexing (without PP at all) and I was wondering what would be 
the right way to go, in order to make the -verify flag work inside the 
module maps. One solution that I see is to pass the comment handlers 
from the PP to the ModuleMapParser, however IMO this would break the 
encapsulation. Do you have better ideas?

Many thanks,
Vassil