static std::vector<VersionPrinterTy> *ExtraVersionPrinters = nullptr;
+#if defined(__GNUC__)
+// GCC and GCC-compatible compilers define __OPTIMIZE__ when optimizations are
+// enabled.
+# if defined(__OPTIMIZE__)
+# define LLVM_IS_DEBUG_BUILD 0
+# else
+# define LLVM_IS_DEBUG_BUILD 1
+# endif
+#elif defined(_MSC_VER)
+// MSVC doesn't have a predefined macro indicating if optimizations are enabled.
+// Use _DEBUG instead. This macro actually corresponds to the choice between
+// debug and release CRTs, but it is a reasonable proxy.
+# if defined(_DEBUG)
+# define LLVM_IS_DEBUG_BUILD 1
+# else
+# define LLVM_IS_DEBUG_BUILD 0
+# endif
+#else
+// Otherwise, for an unknown compiler, assume this is an optimized build.
+# define LLVM_IS_DEBUG_BUILD 0
+#endif
+
namespace {
class VersionPrinter {
public:
OS << " " << LLVM_VERSION_INFO;
#endif
OS << "\n ";
-#ifndef __OPTIMIZE__
+#if LLVM_IS_DEBUG_BUILD
OS << "DEBUG build";
#else
OS << "Optimized build";