diff --git a/llvm/lib/Support/CommandLine.cpp b/llvm/lib/Support/CommandLine.cpp
--- a/llvm/lib/Support/CommandLine.cpp
+++ b/llvm/lib/Support/CommandLine.cpp
@@ -2542,3 +2542,37 @@
   llvm::cl::ParseCommandLineOptions(argc, argv, StringRef(Overview),
                                     &llvm::nulls());
 }
+
+// All Debug.h functionality is a no-op in NDEBUG mode.
+#ifndef NDEBUG
+
+namespace llvm {
+extern ManagedStatic<std::vector<std::string>> CurrentDebugType;
+}
+
+extern unsigned DebugBufferSize;
+
+// -debug - Command line option to enable the DEBUG statements in the passes.
+// This flag may only be enabled in debug builds.
+static cl::opt<bool, true> Debug("debug", cl::desc("Enable debug output"),
+                                 cl::Hidden, cl::location(DebugFlag));
+
+// -debug-buffer-size - Buffer the last N characters of debug output
+// until program termination.
+static cl::opt<unsigned, true>
+    DebugBufferSizeOpt("debug-buffer-size",
+                       cl::desc("Buffer the last N characters of debug output "
+                                "until program termination. "
+                                "[default 0 -- immediate print-out]"),
+                       cl::Hidden,
+                       cl::location(DebugBufferSize));
+
+static cl::list<std::string, ManagedStatic<std::vector<std::string>>>
+    DebugOnly("debug-only",
+              cl::desc("Enable a specific type of debug output (comma "
+                       "separated list of types)"),
+              cl::Hidden, cl::ZeroOrMore, cl::value_desc("debug string"),
+              cl::location(CurrentDebugType), cl::CommaSeparated,
+              cl::callback([](const std::string &) { DebugFlag = true; }));
+
+#endif
diff --git a/llvm/lib/Support/Debug.cpp b/llvm/lib/Support/Debug.cpp
--- a/llvm/lib/Support/Debug.cpp
+++ b/llvm/lib/Support/Debug.cpp
@@ -42,7 +42,7 @@
 /// Exported boolean set by the -debug option.
 bool DebugFlag = false;
 
-static ManagedStatic<std::vector<std::string>> CurrentDebugType;
+ManagedStatic<std::vector<std::string>> CurrentDebugType;
 
 /// Return true if the specified string is the debug type
 /// specified on the command line, or if none was specified on the command line
@@ -79,29 +79,7 @@
 // All Debug.h functionality is a no-op in NDEBUG mode.
 #ifndef NDEBUG
 
-// -debug - Command line option to enable the DEBUG statements in the passes.
-// This flag may only be enabled in debug builds.
-static cl::opt<bool, true>
-Debug("debug", cl::desc("Enable debug output"), cl::Hidden,
-      cl::location(DebugFlag));
-
-// -debug-buffer-size - Buffer the last N characters of debug output
-//until program termination.
-static cl::opt<unsigned>
-DebugBufferSize("debug-buffer-size",
-                cl::desc("Buffer the last N characters of debug output "
-                         "until program termination. "
-                         "[default 0 -- immediate print-out]"),
-                cl::Hidden,
-                cl::init(0));
-
-static cl::list<std::string, ManagedStatic<std::vector<std::string>>>
-    DebugOnly("debug-only",
-              cl::desc("Enable a specific type of debug output (comma "
-                       "separated list of types)"),
-              cl::Hidden, cl::ZeroOrMore, cl::value_desc("debug string"),
-              cl::location(CurrentDebugType), cl::CommaSeparated,
-              cl::callback([](const std::string &) { DebugFlag = true; }));
+unsigned DebugBufferSize = 0;
 
 // Signal handlers - dump debug output on termination.
 static void debug_user_sig_handler(void *Cookie) {