lib/Lex/PPMacroExpansion.cpp

1047   StringRef Feature = II->getName();
1050   if (Feature.startswith("__") && Feature.endswith("__") && Feature.size() >= 4)
1051     Feature = Feature.substr(2, Feature.size() - 4);
1053   return llvm::StringSwitch<bool>(Feature)
1640         StringRef Feature = FeatureII->getName();
1641         Value = llvm::StringSwitch<bool>(Feature)