Index: llvm/trunk/include/llvm/Option/OptTable.h
===================================================================
--- llvm/trunk/include/llvm/Option/OptTable.h
+++ llvm/trunk/include/llvm/Option/OptTable.h
@@ -191,12 +191,16 @@
   /// \param FlagsToInclude - If non-zero, only include options with any
   ///                         of these flags set.
   /// \param FlagsToExclude - Exclude options with any of these flags set.
-  void PrintHelp(raw_ostream &OS, const char *Name,
-                 const char *Title, unsigned FlagsToInclude,
-                 unsigned FlagsToExclude) const;
+  /// \param ShowAllAliases - If true, display all options including aliases
+  ///                         that don't have help texts. By default, we display
+  ///                         only options that are not hidden and have help
+  ///                         texts.
+  void PrintHelp(raw_ostream &OS, const char *Name, const char *Title,
+                 unsigned FlagsToInclude, unsigned FlagsToExclude,
+                 bool ShowAllAliases) const;
 
-  void PrintHelp(raw_ostream &OS, const char *Name,
-                  const char *Title, bool ShowHidden = false) const;
+  void PrintHelp(raw_ostream &OS, const char *Name, const char *Title,
+                 bool ShowHidden = false, bool ShowAllAliases = false) const;
 };
 
 } // end namespace opt
Index: llvm/trunk/lib/Option/OptTable.cpp
===================================================================
--- llvm/trunk/lib/Option/OptTable.cpp
+++ llvm/trunk/lib/Option/OptTable.cpp
@@ -444,15 +444,14 @@
 }
 
 void OptTable::PrintHelp(raw_ostream &OS, const char *Name, const char *Title,
-                         bool ShowHidden) const {
+                         bool ShowHidden, bool ShowAllAliases) const {
   PrintHelp(OS, Name, Title, /*Include*/ 0, /*Exclude*/
-            (ShowHidden ? 0 : HelpHidden));
+            (ShowHidden ? 0 : HelpHidden), ShowAllAliases);
 }
 
-
 void OptTable::PrintHelp(raw_ostream &OS, const char *Name, const char *Title,
-                         unsigned FlagsToInclude,
-                         unsigned FlagsToExclude) const {
+                         unsigned FlagsToInclude, unsigned FlagsToExclude,
+                         bool ShowAllAliases) const {
   OS << "OVERVIEW: " << Title << "\n";
   OS << '\n';
   OS << "USAGE: " << Name << " [options] <inputs>\n";
@@ -476,10 +475,19 @@
     if (Flags & FlagsToExclude)
       continue;
 
-    if (const char *Text = getOptionHelpText(Id)) {
+    // If an alias doesn't have a help text, show a help text for the aliased
+    // option instead.
+    const char *HelpText = getOptionHelpText(Id);
+    if (!HelpText && ShowAllAliases) {
+      const Option Alias = getOption(Id).getAlias();
+      if (Alias.isValid())
+        HelpText = getOptionHelpText(Alias.getID());
+    }
+
+    if (HelpText) {
       const char *HelpGroup = getOptionHelpGroup(*this, Id);
       const std::string &OptName = getOptionHelpName(*this, Id);
-      GroupedOptionHelp[HelpGroup].push_back({OptName, Text});
+      GroupedOptionHelp[HelpGroup].push_back({OptName, HelpText});
     }
   }