Index: clang-tidy/tool/ClangTidyMain.cpp
===================================================================
--- clang-tidy/tool/ClangTidyMain.cpp
+++ clang-tidy/tool/ClangTidyMain.cpp
@@ -262,17 +262,20 @@
 }
 
 static int clangTidyMain(int argc, const char **argv) {
-  CommonOptionsParser OptionsParser(argc, argv, ClangTidyCategory);
+  CommonOptionsParser OptionsParser(argc, argv, ClangTidyCategory, cl::ZeroOrMore);
 
   auto OptionsProvider = createOptionsProvider();
   if (!OptionsProvider)
     return 1;
 
-  std::string FileName = OptionsParser.getSourcePathList().front();
+  std::string FileName ("dummy.cpp");
+  auto pathlist = OptionsParser.getSourcePathList();
+  if (!pathlist.empty()) {
+    FileName = OptionsParser.getSourcePathList().front();
+  }
   ClangTidyOptions EffectiveOptions = OptionsProvider->getOptions(FileName);
   std::vector<std::string> EnabledChecks = getCheckNames(EffectiveOptions);
 
-  // FIXME: Allow using --list-checks without positional arguments.
   if (ListChecks) {
     llvm::outs() << "Enabled checks:";
     for (auto CheckName : EnabledChecks)