Index: include/clang/Basic/DiagnosticDriverKinds.td
===================================================================
--- include/clang/Basic/DiagnosticDriverKinds.td
+++ include/clang/Basic/DiagnosticDriverKinds.td
@@ -230,6 +230,8 @@
   "The last /TC or /TP option takes precedence over earlier instances">;
 def note_drv_address_sanitizer_debug_runtime : Note<
   "AddressSanitizer doesn't support linking with debug runtime libraries yet">;
+def note_drv_supported_values : Note<"supported values are:">;
+def note_drv_supported_value_with_description : Note<" %0 - %1">;
 
 def err_analyzer_config_no_value : Error<
   "analyzer-config option '%0' has a key but no value">;
Index: lib/Frontend/CompilerInvocation.cpp
===================================================================
--- lib/Frontend/CompilerInvocation.cpp
+++ lib/Frontend/CompilerInvocation.cpp
@@ -1694,10 +1694,21 @@
       .Case(alias, LangStandard::lang_##id)
 #include "clang/Frontend/LangStandards.def"
       .Default(LangStandard::lang_unspecified);
-    if (LangStd == LangStandard::lang_unspecified)
+    if (LangStd == LangStandard::lang_unspecified) {
       Diags.Report(diag::err_drv_invalid_value)
         << A->getAsString(Args) << A->getValue();
-    else {
+      // Report all supported standards with description.
+      Diags.Report(diag::note_drv_supported_values);
+      for (unsigned KindValue = 0;
+          KindValue != LangStandard::lang_unspecified;
+          ++KindValue)
+      {
+        const LangStandard &Std = LangStandard::getLangStandardForKind(
+          static_cast<LangStandard::Kind>(KindValue));
+        Diags.Report(diag::note_drv_supported_value_with_description)
+          << Std.getName() << Std.getDescription();
+      }
+    } else {
       // Valid standard, check to make sure language and standard are
       // compatible.
       const LangStandard &Std = LangStandard::getLangStandardForKind(LangStd);