Otherwise, LGTM. ================ Comment at: lib/Basic/DiagnosticIDs.cpp:227 @@ +226,3 @@ +static std::pair<unsigned, bool> +DiagnosticClassCache[diag::DIAG_UPPER_LIMIT] = {}; + ---------------- You need to remove the "= {}" for this to be ok under C++98. http://llvm-reviews.chandlerc.com/D197