diff --git a/ClangTidyCheck.h b/ClangTidyCheck.h
index 54b7251..9fa0d63 100644
--- a/ClangTidyCheck.h
+++ b/ClangTidyCheck.h
@@ -176,6 +176,15 @@ class ClangTidyCheck : public ast_matchers::MatchFinder::MatchCallback {
   DiagnosticBuilder diag(SourceLocation Loc, StringRef Description,
                          DiagnosticIDs::Level Level = DiagnosticIDs::Warning);
 
+  /// Add a diagnostic with the check's name.
+  DiagnosticBuilder diag(StringRef Description,
+                         DiagnosticIDs::Level Level = DiagnosticIDs::Warning);
+
+  /// Adds a diagnostic to report errors in the check's configuration.
+  DiagnosticBuilder
+  configurationDiag(StringRef Description,
+                    DiagnosticIDs::Level Level = DiagnosticIDs::Warning);
+
   /// Should store all options supported by this check with their
   /// current values or default values for options that haven't been overridden.
   ///
@@ -192,7 +201,8 @@ class ClangTidyCheck : public ast_matchers::MatchFinder::MatchCallback {
   public:
     /// Initializes the instance using \p CheckName + "." as a prefix.
     OptionsView(StringRef CheckName,
-                const ClangTidyOptions::OptionMap &CheckOptions);
+                const ClangTidyOptions::OptionMap &CheckOptions,
+                ClangTidyContext *Context);
 
     /// Read a named option from the ``Context``.
     ///
@@ -268,7 +278,7 @@ class ClangTidyCheck : public ast_matchers::MatchFinder::MatchCallback {
       if (llvm::Expected<T> ValueOr = get<T>(LocalName))
         return *ValueOr;
       else
-        logErrToStdErr(ValueOr.takeError());
+        reportOptionParsingError(ValueOr.takeError());
       return Default;
     }
 
@@ -314,7 +324,7 @@ class ClangTidyCheck : public ast_matchers::MatchFinder::MatchCallback {
       if (llvm::Expected<T> ValueOr = getLocalOrGlobal<T>(LocalName))
         return *ValueOr;
       else
-        logErrToStdErr(ValueOr.takeError());
+        reportOptionParsingError(ValueOr.takeError());
       return Default;
     }
 
@@ -330,7 +340,7 @@ class ClangTidyCheck : public ast_matchers::MatchFinder::MatchCallback {
     /// supply the mapping required to convert between ``T`` and a string.
     template <typename T>
     std::enable_if_t<std::is_enum<T>::value, llvm::Expected<T>>
-    get(StringRef LocalName, bool IgnoreCase = false) {
+    get(StringRef LocalName, bool IgnoreCase = false) const {
       if (llvm::Expected<int64_t> ValueOr =
               getEnumInt(LocalName, typeEraseMapping<T>(), false, IgnoreCase))
         return static_cast<T>(*ValueOr);
@@ -349,11 +359,11 @@ class ClangTidyCheck : public ast_matchers::MatchFinder::MatchCallback {
     /// supply the mapping required to convert between ``T`` and a string.
     template <typename T>
     std::enable_if_t<std::is_enum<T>::value, T>
-    get(StringRef LocalName, T Default, bool IgnoreCase = false) {
+    get(StringRef LocalName, T Default, bool IgnoreCase = false) const {
       if (auto ValueOr = get<T>(LocalName, IgnoreCase))
         return *ValueOr;
       else
-        logErrToStdErr(ValueOr.takeError());
+        reportOptionParsingError(ValueOr.takeError());
       return Default;
     }
 
@@ -370,8 +380,7 @@ class ClangTidyCheck : public ast_matchers::MatchFinder::MatchCallback {
     /// supply the mapping required to convert between ``T`` and a string.
     template <typename T>
     std::enable_if_t<std::is_enum<T>::value, llvm::Expected<T>>
-    getLocalOrGlobal(StringRef LocalName,
-                     bool IgnoreCase = false) {
+    getLocalOrGlobal(StringRef LocalName, bool IgnoreCase = false) const {
       if (llvm::Expected<int64_t> ValueOr =
               getEnumInt(LocalName, typeEraseMapping<T>(), true, IgnoreCase))
         return static_cast<T>(*ValueOr);
@@ -391,14 +400,40 @@ class ClangTidyCheck : public ast_matchers::MatchFinder::MatchCallback {
     /// supply the mapping required to convert between ``T`` and a string.
     template <typename T>
     std::enable_if_t<std::is_enum<T>::value, T>
-    getLocalOrGlobal(StringRef LocalName, T Default, bool IgnoreCase = false) {
+    getLocalOrGlobal(StringRef LocalName, T Default,
+                     bool IgnoreCase = false) const {
       if (auto ValueOr = getLocalOrGlobal<T>(LocalName, IgnoreCase))
         return *ValueOr;
       else
-        logErrToStdErr(ValueOr.takeError());
+        reportOptionParsingError(ValueOr.takeError());
       return Default;
     }
 
+    /// Returns the value for the option \p LocalName represented as a ``T``.
+    /// If the option is missing returns None, if the option can't be parsed
+    /// as a ``T``, log that to stderr and return None.
+    template <typename T = std::string>
+    llvm::Optional<T> getOptional(StringRef LocalName) const {
+      if (auto ValueOr = get<T>(LocalName))
+        return *ValueOr;
+      else
+        reportOptionParsingError(ValueOr.takeError());
+      return llvm::None;
+    }
+
+    /// Returns the value for the local or global option \p LocalName
+    /// represented as a ``T``.
+    /// If the option is missing returns None, if the
+    /// option can't be parsed as a ``T``, log that to stderr and return None.
+    template <typename T = std::string>
+    llvm::Optional<T> getOptionalLocalOrGlobal(StringRef LocalName) const {
+      if (auto ValueOr = getLocalOrGlobal<T>(LocalName))
+        return *ValueOr;
+      else
+        reportOptionParsingError(ValueOr.takeError());
+      return llvm::None;
+    }
+
     /// Stores an option with the check-local name \p LocalName with
     /// string value \p Value to \p Options.
     void store(ClangTidyOptions::OptionMap &Options, StringRef LocalName,
@@ -420,7 +455,8 @@ class ClangTidyCheck : public ast_matchers::MatchFinder::MatchCallback {
     /// supply the mapping required to convert between ``T`` and a string.
     template <typename T>
     std::enable_if_t<std::is_enum<T>::value>
-    store(ClangTidyOptions::OptionMap &Options, StringRef LocalName, T Value) {
+    store(ClangTidyOptions::OptionMap &Options, StringRef LocalName,
+          T Value) const {
       ArrayRef<std::pair<T, StringRef>> Mapping =
           OptionEnumMapping<T>::getEnumMapping();
       auto Iter = llvm::find_if(
@@ -436,11 +472,11 @@ class ClangTidyCheck : public ast_matchers::MatchFinder::MatchCallback {
 
     llvm::Expected<int64_t> getEnumInt(StringRef LocalName,
                                        ArrayRef<NameAndValue> Mapping,
-                                       bool CheckGlobal, bool IgnoreCase);
+                                       bool CheckGlobal, bool IgnoreCase) const;
 
     template <typename T>
     std::enable_if_t<std::is_enum<T>::value, std::vector<NameAndValue>>
-    typeEraseMapping() {
+    typeEraseMapping() const {
       ArrayRef<std::pair<T, StringRef>> Mapping =
           OptionEnumMapping<T>::getEnumMapping();
       std::vector<NameAndValue> Result;
@@ -455,10 +491,12 @@ class ClangTidyCheck : public ast_matchers::MatchFinder::MatchCallback {
     void storeInt(ClangTidyOptions::OptionMap &Options, StringRef LocalName,
                   int64_t Value) const;
 
-    static void logErrToStdErr(llvm::Error &&Err);
+    /// Emits a diagnostic if \p Err is not a MissingOptionError.
+    void reportOptionParsingError(llvm::Error &&Err) const;
 
     std::string NamePrefix;
     const ClangTidyOptions::OptionMap &CheckOptions;
+    ClangTidyContext *Context;
   };
 
 private:
@@ -523,6 +561,19 @@ void ClangTidyCheck::OptionsView::store<bool>(
     ClangTidyOptions::OptionMap &Options, StringRef LocalName,
     bool Value) const;
 
+/// Returns the value for the option \p LocalName.
+/// If the option is missing returns None.
+template <>
+Optional<std::string> ClangTidyCheck::OptionsView::getOptional<std::string>(
+    StringRef LocalName) const;
+
+/// Returns the value for the local or global option \p LocalName.
+/// If the option is missing returns None.
+template <>
+Optional<std::string>
+ClangTidyCheck::OptionsView::getOptionalLocalOrGlobal<std::string>(
+    StringRef LocalName) const;
+
 } // namespace tidy
 } // namespace clang
 
diff --git a/ClangTidyDiagnosticConsumer.h b/ClangTidyDiagnosticConsumer.h
index eaa7f18..0792931 100644
--- a/ClangTidyDiagnosticConsumer.h
+++ b/ClangTidyDiagnosticConsumer.h
@@ -96,6 +96,14 @@ class ClangTidyContext {
                          StringRef Message,
                          DiagnosticIDs::Level Level = DiagnosticIDs::Warning);
 
+  DiagnosticBuilder diag(StringRef CheckName, StringRef Message,
+                         DiagnosticIDs::Level Level = DiagnosticIDs::Warning);
+
+  /// Report any errors to do with reading the configuration using this method.
+  DiagnosticBuilder
+  configurationDiag(StringRef Message,
+                    DiagnosticIDs::Level Level = DiagnosticIDs::Warning);
+
   /// Sets the \c SourceManager of the used \c DiagnosticsEngine.
   ///
   /// This is called from the \c ClangTidyCheck base class.
diff --git a/ClangTidyForceLinker.h b/ClangTidyForceLinker.h
index 1d6bd2a..2691d90 100644
--- a/ClangTidyForceLinker.h
+++ b/ClangTidyForceLinker.h
@@ -9,7 +9,7 @@
 #ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_CLANGTIDYFORCELINKER_H
 #define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_CLANGTIDYFORCELINKER_H
 
-#include "clang/Config/config.h"
+#include "clang-tidy-config.h"
 #include "llvm/Support/Compiler.h"
 
 namespace clang {
@@ -20,6 +20,11 @@ extern volatile int AbseilModuleAnchorSource;
 static int LLVM_ATTRIBUTE_UNUSED AbseilModuleAnchorDestination =
     AbseilModuleAnchorSource;
 
+// This anchor is used to force the linker to link the AlteraModule.
+extern volatile int AlteraModuleAnchorSource;
+static int LLVM_ATTRIBUTE_UNUSED AlteraModuleAnchorDestination =
+    AlteraModuleAnchorSource;
+
 // This anchor is used to force the linker to link the AndroidModule.
 extern volatile int AndroidModuleAnchorSource;
 static int LLVM_ATTRIBUTE_UNUSED AndroidModuleAnchorDestination =
@@ -40,6 +45,11 @@ extern volatile int CERTModuleAnchorSource;
 static int LLVM_ATTRIBUTE_UNUSED CERTModuleAnchorDestination =
     CERTModuleAnchorSource;
 
+// This anchor is used to force the linker to link the ConcurrencyModule.
+extern volatile int ConcurrencyModuleAnchorSource;
+static int LLVM_ATTRIBUTE_UNUSED ConcurrencyModuleAnchorDestination =
+    ConcurrencyModuleAnchorSource;
+
 // This anchor is used to force the linker to link the CppCoreGuidelinesModule.
 extern volatile int CppCoreGuidelinesModuleAnchorSource;
 static int LLVM_ATTRIBUTE_UNUSED CppCoreGuidelinesModuleAnchorDestination =
@@ -90,7 +100,7 @@ extern volatile int ModernizeModuleAnchorSource;
 static int LLVM_ATTRIBUTE_UNUSED ModernizeModuleAnchorDestination =
     ModernizeModuleAnchorSource;
 
-#if CLANG_ENABLE_STATIC_ANALYZER &&                                            \
+#if CLANG_TIDY_ENABLE_STATIC_ANALYZER &&                                       \
     !defined(CLANG_TIDY_DISABLE_STATIC_ANALYZER_CHECKS)
 // This anchor is used to force the linker to link the MPIModule.
 extern volatile int MPIModuleAnchorSource;
diff --git a/ClangTidyModule.h b/ClangTidyModule.h
index 31cf477..dd21a8d 100644
--- a/ClangTidyModule.h
+++ b/ClangTidyModule.h
@@ -13,9 +13,7 @@
 #include "llvm/ADT/StringMap.h"
 #include "llvm/ADT/StringRef.h"
 #include <functional>
-#include <map>
 #include <memory>
-#include <string>
 
 namespace clang {
 namespace tidy {
@@ -69,7 +67,7 @@ class ClangTidyCheckFactories {
   std::vector<std::unique_ptr<ClangTidyCheck>>
   createChecks(ClangTidyContext *Context);
 
-  typedef std::map<std::string, CheckFactory> FactoryMap;
+  typedef llvm::StringMap<CheckFactory> FactoryMap;
   FactoryMap::const_iterator begin() const { return Factories.begin(); }
   FactoryMap::const_iterator end() const { return Factories.end(); }
   bool empty() const { return Factories.empty(); }
diff --git a/ClangTidyOptions.h b/ClangTidyOptions.h
index 0f3c1d4..d8a4a14 100644
--- a/ClangTidyOptions.h
+++ b/ClangTidyOptions.h
@@ -14,9 +14,9 @@
 #include "llvm/ADT/StringMap.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/Support/ErrorOr.h"
+#include "llvm/Support/MemoryBufferRef.h"
 #include "llvm/Support/VirtualFileSystem.h"
 #include <functional>
-#include <map>
 #include <string>
 #include <system_error>
 #include <utility>
@@ -56,11 +56,15 @@ struct ClangTidyOptions {
   /// of each registered \c ClangTidyModule.
   static ClangTidyOptions getDefaults();
 
+  /// Overwrites all fields in here by the fields of \p Other that have a value.
+  /// \p Order specifies precedence of \p Other option.
+  ClangTidyOptions &mergeWith(const ClangTidyOptions &Other, unsigned Order);
+
   /// Creates a new \c ClangTidyOptions instance combined from all fields
   /// of this instance overridden by the fields of \p Other that have a value.
   /// \p Order specifies precedence of \p Other option.
-  ClangTidyOptions mergeWith(const ClangTidyOptions &Other,
-                             unsigned Order) const;
+  LLVM_NODISCARD ClangTidyOptions merge(const ClangTidyOptions &Other,
+                                        unsigned Order) const;
 
   /// Checks filter.
   llvm::Optional<std::string> Checks;
@@ -108,7 +112,7 @@ struct ClangTidyOptions {
     unsigned Priority;
   };
   typedef std::pair<std::string, std::string> StringPair;
-  typedef std::map<std::string, ClangTidyValue> OptionMap;
+  typedef llvm::StringMap<ClangTidyValue> OptionMap;
 
   /// Key-value mapping used to store check-specific options.
   OptionMap CheckOptions;
@@ -170,9 +174,10 @@ class ClangTidyOptionsProvider {
 /// returns the same options for all files.
 class DefaultOptionsProvider : public ClangTidyOptionsProvider {
 public:
-  DefaultOptionsProvider(const ClangTidyGlobalOptions &GlobalOptions,
-                         const ClangTidyOptions &Options)
-      : GlobalOptions(GlobalOptions), DefaultOptions(Options) {}
+  DefaultOptionsProvider(ClangTidyGlobalOptions GlobalOptions,
+                         ClangTidyOptions Options)
+      : GlobalOptions(std::move(GlobalOptions)),
+        DefaultOptions(std::move(Options)) {}
   const ClangTidyGlobalOptions &getGlobalOptions() override {
     return GlobalOptions;
   }
@@ -184,11 +189,11 @@ class DefaultOptionsProvider : public ClangTidyOptionsProvider {
 };
 
 class FileOptionsBaseProvider : public DefaultOptionsProvider {
-public:
+protected:
   // A pair of configuration file base name and a function parsing
   // configuration from text in the corresponding format.
   typedef std::pair<std::string, std::function<llvm::ErrorOr<ClangTidyOptions>(
-                                     llvm::StringRef)>>
+                                     llvm::MemoryBufferRef)>>
       ConfigFileHandler;
 
   /// Configuration file handlers listed in the order of priority.
@@ -210,16 +215,15 @@ class FileOptionsBaseProvider : public DefaultOptionsProvider {
   /// take precedence over ".clang-tidy" if both reside in the same directory.
   typedef std::vector<ConfigFileHandler> ConfigFileHandlers;
 
-  FileOptionsBaseProvider(
-      const ClangTidyGlobalOptions &GlobalOptions,
-      const ClangTidyOptions &DefaultOptions,
-      const ClangTidyOptions &OverrideOptions,
-      llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem> FS = nullptr);
+  FileOptionsBaseProvider(ClangTidyGlobalOptions GlobalOptions,
+                          ClangTidyOptions DefaultOptions,
+                          ClangTidyOptions OverrideOptions,
+                          llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem> FS);
 
-  FileOptionsBaseProvider(const ClangTidyGlobalOptions &GlobalOptions,
-                          const ClangTidyOptions &DefaultOptions,
-                          const ClangTidyOptions &OverrideOptions,
-                          const ConfigFileHandlers &ConfigHandlers);
+  FileOptionsBaseProvider(ClangTidyGlobalOptions GlobalOptions,
+                          ClangTidyOptions DefaultOptions,
+                          ClangTidyOptions OverrideOptions,
+                          ConfigFileHandlers ConfigHandlers);
 
 protected:
   void addRawFileOptions(llvm::StringRef AbsolutePath,
@@ -240,10 +244,8 @@ class FileOptionsBaseProvider : public DefaultOptionsProvider {
 class ConfigOptionsProvider : public FileOptionsBaseProvider {
 public:
   ConfigOptionsProvider(
-      const ClangTidyGlobalOptions &GlobalOptions,
-      const ClangTidyOptions &DefaultOptions,
-      const ClangTidyOptions &ConfigOptions,
-      const ClangTidyOptions &OverrideOptions,
+      ClangTidyGlobalOptions GlobalOptions, ClangTidyOptions DefaultOptions,
+      ClangTidyOptions ConfigOptions, ClangTidyOptions OverrideOptions,
       llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem> FS = nullptr);
   std::vector<OptionsSource> getRawOptions(llvm::StringRef FileName) override;
 
@@ -272,9 +274,8 @@ class FileOptionsProvider : public FileOptionsBaseProvider {
   /// If any of the \param OverrideOptions fields are set, they will override
   /// whatever options are read from the configuration file.
   FileOptionsProvider(
-      const ClangTidyGlobalOptions &GlobalOptions,
-      const ClangTidyOptions &DefaultOptions,
-      const ClangTidyOptions &OverrideOptions,
+      ClangTidyGlobalOptions GlobalOptions, ClangTidyOptions DefaultOptions,
+      ClangTidyOptions OverrideOptions,
       llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem> FS = nullptr);
 
   /// Initializes the \c FileOptionsProvider instance with a custom set
@@ -294,10 +295,10 @@ class FileOptionsProvider : public FileOptionsBaseProvider {
   /// that can parse configuration from this file type. The configuration files
   /// in each directory are searched for in the order of appearance in
   /// \p ConfigHandlers.
-  FileOptionsProvider(const ClangTidyGlobalOptions &GlobalOptions,
-                      const ClangTidyOptions &DefaultOptions,
-                      const ClangTidyOptions &OverrideOptions,
-                      const ConfigFileHandlers &ConfigHandlers);
+  FileOptionsProvider(ClangTidyGlobalOptions GlobalOptions,
+                      ClangTidyOptions DefaultOptions,
+                      ClangTidyOptions OverrideOptions,
+                      ConfigFileHandlers ConfigHandlers);
 
   std::vector<OptionsSource> getRawOptions(llvm::StringRef FileName) override;
 };
@@ -308,7 +309,13 @@ std::error_code parseLineFilter(llvm::StringRef LineFilter,
 
 /// Parses configuration from JSON and returns \c ClangTidyOptions or an
 /// error.
-llvm::ErrorOr<ClangTidyOptions> parseConfiguration(llvm::StringRef Config);
+llvm::ErrorOr<ClangTidyOptions>
+parseConfiguration(llvm::MemoryBufferRef Config);
+
+using DiagCallback = llvm::function_ref<void(const llvm::SMDiagnostic &)>;
+
+llvm::ErrorOr<ClangTidyOptions>
+parseConfigurationWithDiags(llvm::MemoryBufferRef Config, DiagCallback Handler);
 
 /// Serializes configuration to a YAML-encoded string.
 std::string configurationAsText(const ClangTidyOptions &Options);
diff --git a/GlobList.h b/GlobList.h
index 4edb03b..fe68a34 100644
--- a/GlobList.h
+++ b/GlobList.h
@@ -10,9 +10,9 @@
 #define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_GLOBLIST_H
 
 #include "clang/Basic/LLVM.h"
+#include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/Support/Regex.h"
-#include <vector>
 
 namespace clang {
 namespace tidy {
@@ -33,15 +33,15 @@ class GlobList {
 
   /// Returns \c true if the pattern matches \p S. The result is the last
   /// matching glob's Positive flag.
-  bool contains(StringRef S);
+  bool contains(StringRef S) const;
 
 private:
 
   struct GlobListItem {
     bool IsPositive;
-    mutable llvm::Regex Regex;
+    llvm::Regex Regex;
   };
-  std::vector<GlobListItem> Items;
+  SmallVector<GlobListItem, 0> Items;
 };
 
 } // end namespace tidy
diff --git a/README.md b/README.md
index fb8e067..358de1e 100644
--- a/README.md
+++ b/README.md
@@ -15,4 +15,4 @@ It offers:
 
 In the build directory of AliceO2 (containing the CMake compilations database in form of `compile_command.json`), run
 
-    run_O2CodeChecker.py -clang-tidy-binary `which O2codecheck` -checks=-*,alice*
+    run_O2CodeChecker.py -clang-tidy-binary `which O2codecheck` -checks=*,alice*
diff --git a/clang-tidy-config.h b/clang-tidy-config.h
new file mode 100644
index 0000000..c3847d4
--- /dev/null
+++ b/clang-tidy-config.h
@@ -0,0 +1,10 @@
+/* This generated file is for internal use. Do not include it from headers. */
+
+#ifdef CLANG_TIDY_CONFIG_H
+#error clang-tidy-config.h can only be included once
+#else
+#define CLANG_TIDY_CONFIG_H
+
+#define CLANG_TIDY_ENABLE_STATIC_ANALYZER 1
+
+#endif
diff --git a/tool/CMakeLists.txt b/tool/CMakeLists.txt
index 8371e0a..4d00fa4 100644
--- a/tool/CMakeLists.txt
+++ b/tool/CMakeLists.txt
@@ -21,11 +21,13 @@ target_link_libraries(O2codecheck
   clangTidyReportingModule
 
   # include checkers available from main clang-tidy
+  clangTidyAlteraModule
   clangTidyAndroidModule
   clangTidyAbseilModule
   clangTidyBoostModule
   clangTidyBugproneModule
   clangTidyCERTModule
+  clangTidyConcurrencyModule
   clangTidyCppCoreGuidelinesModule
   clangTidyDarwinModule
   clangTidyFuchsiaModule
diff --git a/tool/ClangTidyMain.cpp b/tool/ClangTidyMain.cpp
index 70d9bef..176d5e8 100644
--- a/tool/ClangTidyMain.cpp
+++ b/tool/ClangTidyMain.cpp
@@ -14,6 +14,7 @@
 ///
 //===----------------------------------------------------------------------===//
 
+#include "ClangTidyMain.h"
 #include "../ClangTidy.h"
 #include "../ClangTidyForceLinker.h"
 #include "../GlobList.h"
@@ -167,6 +168,16 @@ each source file in its parent directories.
 )"),
                                    cl::init(""), cl::cat(ClangTidyCategory));
 
+static cl::opt<std::string> ConfigFile("config-file", cl::desc(R"(
+Specify the path of .clang-tidy or custom config file:
+ e.g. --config-file=/some/path/myTidyConfigFile
+This option internally works exactly the same way as
+ --config option after reading specified config file.
+Use either --config-file or --config, not both.
+)"),
+                                       cl::init(""),
+                                       cl::cat(ClangTidyCategory));
+
 static cl::opt<bool> DumpConfig("dump-config", cl::desc(R"(
 Dumps configuration in the YAML format to
 stdout. This option can be used along with a
@@ -301,21 +312,45 @@ static std::unique_ptr<ClangTidyOptionsProvider> createOptionsProvider(
   if (UseColor.getNumOccurrences() > 0)
     OverrideOptions.UseColor = UseColor;
 
-  if (!Config.empty()) {
-    if (llvm::ErrorOr<ClangTidyOptions> ParsedConfig =
-            parseConfiguration(Config)) {
+  auto LoadConfig =
+      [&](StringRef Configuration,
+          StringRef Source) -> std::unique_ptr<ClangTidyOptionsProvider> {
+    llvm::ErrorOr<ClangTidyOptions> ParsedConfig =
+        parseConfiguration(MemoryBufferRef(Configuration, Source));
+    if (ParsedConfig)
       return std::make_unique<ConfigOptionsProvider>(
-          GlobalOptions,
-          ClangTidyOptions::getDefaults().mergeWith(DefaultOptions, 0),
-          *ParsedConfig, OverrideOptions, std::move(FS));
-    } else {
-      llvm::errs() << "Error: invalid configuration specified.\n"
-                   << ParsedConfig.getError().message() << "\n";
+          std::move(GlobalOptions),
+          ClangTidyOptions::getDefaults().merge(DefaultOptions, 0),
+          std::move(*ParsedConfig), std::move(OverrideOptions), std::move(FS));
+    llvm::errs() << "Error: invalid configuration specified.\n"
+                 << ParsedConfig.getError().message() << "\n";
+    return nullptr;
+  };
+
+  if (ConfigFile.getNumOccurrences() > 0) {
+    if (Config.getNumOccurrences() > 0) {
+      llvm::errs() << "Error: --config-file and --config are "
+                      "mutually exclusive. Specify only one.\n";
       return nullptr;
     }
+
+    llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> Text =
+        llvm::MemoryBuffer::getFile(ConfigFile);
+    if (std::error_code EC = Text.getError()) {
+      llvm::errs() << "Error: can't read config-file '" << ConfigFile
+                   << "': " << EC.message() << "\n";
+      return nullptr;
+    }
+
+    return LoadConfig((*Text)->getBuffer(), ConfigFile);
   }
-  return std::make_unique<FileOptionsProvider>(GlobalOptions, DefaultOptions,
-                                                OverrideOptions, std::move(FS));
+
+  if (Config.getNumOccurrences() > 0)
+    return LoadConfig(Config, "<command-line-config>");
+
+  return std::make_unique<FileOptionsProvider>(
+      std::move(GlobalOptions), std::move(DefaultOptions),
+      std::move(OverrideOptions), std::move(FS));
 }
 
 llvm::IntrusiveRefCntPtr<vfs::FileSystem>
@@ -358,7 +393,7 @@ int clangTidyMain(int argc, const char **argv) {
         getVfsFromFile(VfsOverlay, BaseFS);
     if (!VfsFromFile)
       return 1;
-    BaseFS->pushOverlay(VfsFromFile);
+    BaseFS->pushOverlay(std::move(VfsFromFile));
   }
 
   auto OwningOptionsProvider = createOptionsProvider(BaseFS);
@@ -422,9 +457,8 @@ int clangTidyMain(int argc, const char **argv) {
   if (DumpConfig) {
     EffectiveOptions.CheckOptions =
         getCheckOptions(EffectiveOptions, AllowEnablingAnalyzerAlphaCheckers);
-    llvm::outs() << configurationAsText(
-                        ClangTidyOptions::getDefaults().mergeWith(
-                            EffectiveOptions, 0))
+    llvm::outs() << configurationAsText(ClangTidyOptions::getDefaults().merge(
+                        EffectiveOptions, 0))
                  << "\n";
     return 0;
   }
diff --git a/tool/ClangTidyMain.h b/tool/ClangTidyMain.h
new file mode 100644
index 0000000..f87f84b
--- /dev/null
+++ b/tool/ClangTidyMain.h
@@ -0,0 +1,23 @@
+//===--- tools/extra/clang-tidy/ClangTidyMain.h - Clang tidy tool -------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+///
+///  \file This file declares the main function for the clang-tidy tool.
+///
+///  This tool uses the Clang Tooling infrastructure, see
+///    http://clang.llvm.org/docs/HowToSetupToolingForLLVM.html
+///  for details on setting it up with LLVM source tree.
+///
+//===----------------------------------------------------------------------===//
+
+namespace clang {
+namespace tidy {
+
+int clangTidyMain(int argc, const char **argv);
+
+} // namespace tidy
+} // namespace clang