Sure. Basically, I had verified that the necessary header llvm/ADT/StringMap.h is present in my llvm path and the file does have StringMap symbol defined inside llvm namespace. Hence, I feel the issue is perhaps, the header file path is not correctly setup. When I look at the CC commands, I see -isystem <llvm/include/path> - is this sufficient ? I was expecting it should have been - -I<llvm/include/path> ?
(btw, I am using llvm 9.0)