No - the enum constant value is known to clang, see `const llvm::APSInt& clang::EnumConstantDecl::getInitVal() const`. You can get the value as a Long64_t through the APSInt as documented here: http://llvm.org/doxygen/classllvm_1_1APSInt.html  / http://llvm.org/doxygen/classllvm_1_1APInt.html - see e.g. `APSInt::isSigned()` and `APInt::getSExtValue () const` or `APInt::getZExtValue () const`