--- /dev/null
+include "llvm/Option/OptParser.td"
+
+// lib.exe accepts options starting with either a dash or a slash.
+
+// Flag that takes no arguments.
+class F<string name> : Flag<["/", "-", "-?"], name>;
+
+// Flag that takes one argument after ":".
+class P<string name, string help> :
+ Joined<["/", "-", "-?"], name#":">, HelpText<help>;
+
+def out : P<"out", "Path to file to write output">;
+
+//==============================================================================
+// The flags below do nothing. They are defined only for lib.exe compatibility.
+//==============================================================================
+def nologo : F<"nologo">;