in lib/LLVMSupport/Support/Triple.cpp [173:215]
StringRef Triple::getOSTypeName(OSType Kind) {
switch (Kind) {
case UnknownOS: return "unknown";
case Ananas: return "ananas";
case CloudABI: return "cloudabi";
case Darwin: return "darwin";
case DragonFly: return "dragonfly";
case FreeBSD: return "freebsd";
case Fuchsia: return "fuchsia";
case IOS: return "ios";
case KFreeBSD: return "kfreebsd";
case Linux: return "linux";
case Lv2: return "lv2";
case MacOSX: return "macosx";
case NetBSD: return "netbsd";
case OpenBSD: return "openbsd";
case Solaris: return "solaris";
case Win32: return "windows";
case Haiku: return "haiku";
case Minix: return "minix";
case RTEMS: return "rtems";
case NaCl: return "nacl";
case CNK: return "cnk";
case AIX: return "aix";
case CUDA: return "cuda";
case NVCL: return "nvcl";
case AMDHSA: return "amdhsa";
case PS4: return "ps4";
case ELFIAMCU: return "elfiamcu";
case TvOS: return "tvos";
case WatchOS: return "watchos";
case Mesa3D: return "mesa3d";
case Contiki: return "contiki";
case AMDPAL: return "amdpal";
case HermitCore: return "hermit";
case Hurd: return "hurd";
case WASI: return "wasi";
case Emscripten: return "emscripten";
}
llvm_unreachable("Invalid OSType");
}