Index: clang/include/clang/Tooling/CommonOptionsParser.h
===================================================================
--- clang/include/clang/Tooling/CommonOptionsParser.h
+++ clang/include/clang/Tooling/CommonOptionsParser.h
@@ -63,21 +63,8 @@
 /// }
 /// \endcode
 class CommonOptionsParser {
-public:
-  /// Parses command-line, initializes a compilation database.
-  ///
-  /// This constructor can change argc and argv contents, e.g. consume
-  /// command-line options used for creating FixedCompilationDatabase.
-  ///
-  /// All options not belonging to \p Category become hidden.
-  ///
-  /// This constructor exits program in case of error.
-  CommonOptionsParser(int &argc, const char **argv,
-                      llvm::cl::OptionCategory &Category,
-                      const char *Overview = nullptr)
-      : CommonOptionsParser(argc, argv, Category, llvm::cl::OneOrMore,
-                            Overview) {}
 
+protected:
   /// Parses command-line, initializes a compilation database.
   ///
   /// This constructor can change argc and argv contents, e.g. consume
@@ -86,16 +73,17 @@
   /// All options not belonging to \p Category become hidden.
   ///
   /// It also allows calls to set the required number of positional parameters.
-  CommonOptionsParser(int &argc, const char **argv,
-                      llvm::cl::OptionCategory &Category,
-                      llvm::cl::NumOccurrencesFlag OccurrencesFlag,
-                      const char *Overview = nullptr);
+  CommonOptionsParser(
+      int &argc, const char **argv, llvm::cl::OptionCategory &Category,
+      llvm::cl::NumOccurrencesFlag OccurrencesFlag = llvm::cl::OneOrMore,
+      const char *Overview = nullptr);
 
+public:
   /// A factory method that is similar to the above constructor, except
   /// this returns an error instead exiting the program on error.
   static llvm::Expected<CommonOptionsParser>
   create(int &argc, const char **argv, llvm::cl::OptionCategory &Category,
-         llvm::cl::NumOccurrencesFlag OccurrencesFlag,
+         llvm::cl::NumOccurrencesFlag OccurrencesFlag = llvm::cl::OneOrMore,
          const char *Overview = nullptr);
 
   /// Returns a reference to the loaded compilations database.
Index: clang/lib/Tooling/CommonOptionsParser.cpp
===================================================================
--- clang/lib/Tooling/CommonOptionsParser.cpp
+++ clang/lib/Tooling/CommonOptionsParser.cpp
@@ -115,8 +115,7 @@
   // Stop initializing if command-line option parsing failed.
   if (!cl::ParseCommandLineOptions(argc, argv, Overview, &OS)) {
     OS.flush();
-    return llvm::make_error<llvm::StringError>("[CommonOptionsParser]: " +
-                                                   ErrorMessage,
+    return llvm::make_error<llvm::StringError>(ErrorMessage,
                                                llvm::inconvertibleErrorCode());
   }
 
Index: clang/tools/clang-check/ClangCheck.cpp
===================================================================
--- clang/tools/clang-check/ClangCheck.cpp
+++ clang/tools/clang-check/ClangCheck.cpp
@@ -160,7 +160,13 @@
   llvm::InitializeAllAsmPrinters();
   llvm::InitializeAllAsmParsers();
 
-  CommonOptionsParser OptionsParser(argc, argv, ClangCheckCategory);
+  auto ExpectedParser =
+      CommonOptionsParser::create(argc, argv, ClangCheckCategory);
+  if (!ExpectedParser) {
+    llvm::errs() << ExpectedParser.takeError();
+    return 1;
+  }
+  CommonOptionsParser &OptionsParser = ExpectedParser.get();
   ClangTool Tool(OptionsParser.getCompilations(),
                  OptionsParser.getSourcePathList());
 
Index: clang/tools/clang-extdef-mapping/ClangExtDefMapGen.cpp
===================================================================
--- clang/tools/clang-extdef-mapping/ClangExtDefMapGen.cpp
+++ clang/tools/clang-extdef-mapping/ClangExtDefMapGen.cpp
@@ -119,8 +119,13 @@
   const char *Overview = "\nThis tool collects the USR name and location "
                          "of external definitions in the source files "
                          "(excluding headers).\n";
-  CommonOptionsParser OptionsParser(argc, argv, ClangExtDefMapGenCategory,
-                                    cl::ZeroOrMore, Overview);
+  auto ExpectedParser = CommonOptionsParser::create(
+      argc, argv, ClangExtDefMapGenCategory, cl::ZeroOrMore, Overview);
+  if (!ExpectedParser) {
+    llvm::errs() << ExpectedParser.takeError();
+    return 1;
+  }
+  CommonOptionsParser &OptionsParser = ExpectedParser.get();
 
   ClangTool Tool(OptionsParser.getCompilations(),
                  OptionsParser.getSourcePathList());
Index: clang/tools/clang-refactor/ClangRefactor.cpp
===================================================================
--- clang/tools/clang-refactor/ClangRefactor.cpp
+++ clang/tools/clang-refactor/ClangRefactor.cpp
@@ -612,9 +612,14 @@
 
   ClangRefactorTool RefactorTool;
 
-  CommonOptionsParser Options(
+  auto ExpectedParser = CommonOptionsParser::create(
       argc, argv, cl::GeneralCategory, cl::ZeroOrMore,
       "Clang-based refactoring tool for C, C++ and Objective-C");
+  if (!ExpectedParser) {
+    llvm::errs() << ExpectedParser.takeError();
+    return 1;
+  }
+  CommonOptionsParser &Options = ExpectedParser.get();
 
   if (auto Err = RefactorTool.Init()) {
     llvm::errs() << llvm::toString(std::move(Err)) << "\n";
Index: clang/tools/clang-rename/ClangRename.cpp
===================================================================
--- clang/tools/clang-rename/ClangRename.cpp
+++ clang/tools/clang-rename/ClangRename.cpp
@@ -98,7 +98,13 @@
                            cl::cat(ClangRenameOptions));
 
 int main(int argc, const char **argv) {
-  tooling::CommonOptionsParser OP(argc, argv, ClangRenameOptions);
+  auto ExpectedParser =
+      tooling::CommonOptionsParser::create(argc, argv, ClangRenameOptions);
+  if (!ExpectedParser) {
+    llvm::errs() << ExpectedParser.takeError();
+    return 1;
+  }
+  tooling::CommonOptionsParser &OP = ExpectedParser.get();
 
   if (!Input.empty()) {
     // Populate QualifiedNames and NewNames from a YAML file.