[clang-tidy] Reworked enum options handling(again)

[njames93]

Summary

Following on from D77085, I was never happy with the passing a mapping to the option get/store functions. This patch addresses this by using explicit specializations to handle the serializing and deserializing of enum options.

[njames93]

clang-tools-extra/clang-tidy/cppcoreguidelines/ProBoundsConstantArrayIndexCheck.cpp

30

As a side bonus, this originally incorrect code would cast IncludeStyle to an int, then store that value. Now it will store it as the correct enum. Any other enums passed to store will error out if there is no mapping specialization for them, forcing you to either declare the mapping or cast it to an integer type

[njames93]

Update doc comments.

[aaron.ballman]

I like the direction of this, thank you! LGTM with a small suggestion, but you should wait a few days in case one of the other reviewers has comments.

clang-tools-extra/clang-tidy/ClangTidyCheck.h

31–32

Any reason not to do:

static ArrayRef<std::pair<T, StringRef>> getEnumMapping() = delete;

so you get a nice error if you instantiate something without the required definition?

[njames93]

Use = delete for getEnumMapping in template definition.

clang-tools-extra/clang-tidy/ClangTidyCheck.h

31–32

I need to read the c++ standard, never even realised you could delete static functions like that.

[njames93]

• Fix compilation failure on rebase

[thakis]

This breaks chevk-clang-tools in mac: http://45.33.8.238/mac/16292/step_8.txt

Please take a look and revert for now if it takes a while to fix.

[njames93]

In D82188#2118769, @thakis wrote:

This breaks chevk-clang-tools in mac: http://45.33.8.238/mac/16292/step_8.txt

Please take a look and revert for now if it takes a while to fix.

Are you sure that this is the offending patch? I don't touch the diagnostics consumer in this patch and this is essentially NFC.

[thakis]

It's the only change on the blame list, things pass consistently before the change, and fail consistently after it.

[thakis]

I reverted this in 8f73c4432b5fa8510c99a5053c07dc70a610e1fb and check-clang-tools stopped failing.

[njames93]

In D82188#2118885, @thakis wrote:

It's the only change on the blame list, things pass consistently before the change, and fail consistently after it.

Do you happen to have a proper build log for the failing build. That bot doesn't show what happened when building, in fact it says there was no work to do when building which seems to confuse me. My best guess for the fail is infrastructure related.

Edit: http://45.33.8.238/mac/16282/log.txt this is the log I want. It shows the failure and that this is the cause, but I'm still struggling to see what the actual cause is?????

[njames93]

I've relanded this with some sanity checks in 37cc4fa2eaa3d03ca8cd4947eb0d4c60e3c9b45c. If it fails again without those asserts I'll go back to the drawing board

[njames93]

Figuring out mac crash

[njames93]

clang-tools-extra/unittests/clang-tidy/ClangTidyDiagnosticConsumerTest.cpp

31

This assert is failing on the mac builds - http://45.33.8.238/mac/16309/step_8.txt yet I can see no logical reason for it

[njames93]

@thakis Do those bots use gn, could that be the cause of the failures?
From what I can see gn isn't fully supported by llvm and could certainly be the cause of failing builds.
Do we have any build bots on mac that don't use gn but passed the test case?

[thakis]

In D82188#2119393, @njames93 wrote:

@thakis Do those bots use gn, could that be the cause of the failures?

It's possible, but unlikely, given that your change doesn't touch any build files.

…and indeed, I checked out 8f73c4432b5fa8510c99a5053c07dc70a610e1fb^ (the commit before the revert) and ran ninja -j200 check-clang-tools in a cmake build and it repros there too:

-- Build files have been written to: /Users/thakis/src/llvm-build-project
[2185/2306] Linking CXX static library lib/libclangDriver.a
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/libtool: warning same member name (VE.cpp.o) in output file used for input files: tools/clang/lib/Driver/CMakeFiles/obj.clangDriver.dir/ToolChains/VE.cpp.o and: tools/clang/lib/Driver/CMakeFiles/obj.clangDriver.dir/ToolChains/Arch/VE.cpp.o (due to use of basename, truncation, blank padding or duplicate input files)
[2305/2306] Running the Clang extra tools' regression tests
FAIL: Extra Tools Unit Tests :: clang-tidy/./ClangTidyTests/ClangTidyDiagnosticConsumer.SortsErrors (799 of 924)
******************** TEST 'Extra Tools Unit Tests :: clang-tidy/./ClangTidyTests/ClangTidyDiagnosticConsumer.SortsErrors' FAILED ********************
Note: Google Test filter = ClangTidyDiagnosticConsumer.SortsErrors
[==========] Running 1 test from 1 test case.
[----------] Global test environment set-up.
[----------] 1 test from ClangTidyDiagnosticConsumer
[ RUN      ] ClangTidyDiagnosticConsumer.SortsErrors
/Users/thakis/src/llvm-project/clang-tools-extra/unittests/clang-tidy/ClangTidyDiagnosticConsumerTest.cpp:27: Failure
      Expected: 2ul
      Which is: 2
To be equal to: Errors.size()
      Which is: 0
0  ClangTidyTests           0x0000000106468c65 llvm::sys::PrintStackTrace(llvm::raw_ostream&) + 37
1  ClangTidyTests           0x0000000106467b36 llvm::sys::RunSignalHandlers() + 198
2  ClangTidyTests           0x0000000106469246 SignalHandler(int) + 262
3  libsystem_platform.dylib 0x00007fff6b5055fd _sigtramp + 29
4  libsystem_malloc.dylib   0x00007fff6b4c5a3d tiny_malloc_from_free_list + 555
5  ClangTidyTests           0x000000010647186f testing::Test::Run() + 527
6  ClangTidyTests           0x00000001064726e6 testing::TestInfo::Run() + 566
7  ClangTidyTests           0x0000000106472f17 testing::TestCase::Run() + 247
8  ClangTidyTests           0x000000010647b737 testing::internal::UnitTestImpl::RunAllTests() + 1287
9  ClangTidyTests           0x000000010647b1bb testing::UnitTest::Run() + 171
10 ClangTidyTests           0x000000010646a4c9 main + 121
11 libdyld.dylib            0x00007fff6b30ccc9 start + 1

********************
********************
Failed Tests (1):
  Extra Tools Unit Tests :: clang-tidy/./ClangTidyTests/ClangTidyDiagnosticConsumer.SortsErrors


Testing Time: 21.55s
  Unsupported      :   3
  Passed           : 918
  Expectedly Failed:   2
  Failed           :   1

I then did the same again with the change reverted, and everything passes there.

From what I can see gn isn't fully supported by llvm and could certainly be the cause of failing builds.
Do we have any build bots on mac that don't use gn but passed the test case?

It's correct that the gn build isn't supported (not just not fully: not at all) and if this would break things only there, then that wouldn't be a reason for revert. In practice, things very rarely are broken in the GN build only, and the GN bots cycle an order of magnitude faster, so they tend to show problems before the cmake bots do.

In this case, trunk was broken for > 12h, so I'd expect there's lots of evidence of this being broken on cmake bots too. However, the mac bots aren't on buildbot but on http://green.lab.llvm.org/green/ for whatever reason, and I find that page hard to read. http://green.lab.llvm.org/green/job/clang-stage1-RA/ has a bunch of red on the LHS … ah yeah http://green.lab.llvm.org/green/job/clang-stage1-RA/11966/console has " Extra Tools Unit Tests :: clang-tidy/./ClangTidyTests/ClangTidyDiagnosticConsumer.SortsErrors" at the bottom.

So this showed up on the regular mac bots, yes.

---

The tree's been broken for over half a day to this. I'd suggest taking breakage supports a bit more serious going forward, instead of replying with "it can't possibly be this patch" and "it must be bot setup weirdness" going forward :)

[njames93]

In D82188#2119980, @thakis wrote:

In this case, trunk was broken for > 12h, so I'd expect there's lots of evidence of this being broken on cmake bots too. However, the mac bots aren't on buildbot but on http://green.lab.llvm.org/green/ for whatever reason, and I find that page hard to read. http://green.lab.llvm.org/green/job/clang-stage1-RA/ has a bunch of red on the LHS … ah yeah http://green.lab.llvm.org/green/job/clang-stage1-RA/11966/console has " Extra Tools Unit Tests :: clang-tidy/./ClangTidyTests/ClangTidyDiagnosticConsumer.SortsErrors" at the bottom.

So this showed up on the regular mac bots, yes.

---

The tree's been broken for over half a day to this. I'd suggest taking breakage supports a bit more serious going forward, instead of replying with "it can't possibly be this patch" and "it must be bot setup weirdness" going forward :)

Thanks for clarifying about the regular mac bots. Is this isolated to just mac bots?

If it is isolated then the logical reason for this failure would be a subtle bug in the host toolchain.
When I landed for a second time, I noticed that the TestCheck in ClangTidyDiagnosticsConsumerTest.cpp gets instantiated, but the registerMatchers function never gets called, this is the root cause for why the test fails.
However you just need to read the the code to see how that situation shouldn't happen.
Without a mac to test on, I wont be able to investigate further(no pre merge mac test bot also makes this significantly harder for me to test), Tried testing on older clang compiler and wasn't able to reproduce any error.

[njames93]

Solved the mac issue

[njames93]

clang-tools-extra/unittests/clang-tidy/ClangTidyOptionsTest.cpp

225

@aaron.ballman @thakis I figured out a way to prevent the test cases failing on mac, still can't figure out the root cause. Would this be acceptable for now?

As far as I can see some subtle linker bug in the default mac os linker isn't happy when this test case is included. This actual test case runs just fine, but the test in ClangTidyDiagnosticsConsumerTest doesn't run properly. It appears to instantiate the context and then instantiate the check, but it never attempts to register it, causing the whole test case to fail.
clang-tidy builds just fine which has many uses of this new enum handling and check-clang-tools also runs without a hitch.

clang-tools-extra/clang-tidy/ClangTidyCheck.h

 #include <vector>
 
 namespace clang {
 
 class CompilerInstance;
 
 namespace tidy {
 
+/// This class should be specialized by any enum type that needs to be converted
+/// to and from an \ref llvm::StringRef.
+template <class T> struct OptionEnumMapping {
+  // Specializations of this struct must implement this function.
+  static ArrayRef<std::pair<T, StringRef>> getEnumMapping() = delete;
+};
+
 template <typename T> class OptionError : public llvm::ErrorInfo<T> {
   std::error_code convertToErrorCode() const override {
     return llvm::inconvertibleErrorCode();
   }
 
 public:
   void log(raw_ostream &OS) const override { OS << this->message(); }
 };
getLocalOrGlobal(StringRef LocalName, T Default) const {
       if (llvm::Expected<T> ValueOr = getLocalOrGlobal<T>(LocalName))
         return *ValueOr;
       else
         logErrToStdErr(ValueOr.takeError());
       return Default;
     }
 
     /// Read a named option from the ``Context`` and parse it as an
-    /// enum type ``T`` using the \p Mapping provided. If \p IgnoreCase is set,
-    /// it will search the mapping ignoring the case.
+    /// enum type ``T``.
     ///
     /// Reads the option with the check-local name \p LocalName from the
     /// ``CheckOptions``. If the corresponding key is not present, returns a
     /// ``MissingOptionError``. If the key can't be parsed as a ``T`` returns a
     /// ``UnparseableEnumOptionError``.
+    ///
+    /// \ref clang::tidy::OptionEnumMapping must be specialized for ``T`` to
+    /// 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, ArrayRef<std::pair<StringRef, T>> Mapping,
-        bool IgnoreCase = false) {
-      if (llvm::Expected<int64_t> ValueOr = getEnumInt(
-              LocalName, typeEraseMapping(Mapping), false, IgnoreCase))
+    get(StringRef LocalName, bool IgnoreCase = false) {
+      if (llvm::Expected<int64_t> ValueOr =
+              getEnumInt(LocalName, typeEraseMapping<T>(), false, IgnoreCase))
         return static_cast<T>(*ValueOr);
       else
         return std::move(ValueOr.takeError());
     }
 
     /// Read a named option from the ``Context`` and parse it as an
-    /// enum type ``T`` using the \p Mapping provided. If \p IgnoreCase is set,
-    /// it will search the mapping ignoring the case.
+    /// enum type ``T``.
     ///
     /// Reads the option with the check-local name \p LocalName from the
     /// ``CheckOptions``. If the corresponding key is not present or it can't be
     /// parsed as a ``T``, returns \p Default.
+    ///
+    /// \ref clang::tidy::OptionEnumMapping must be specialized for ``T`` to
+    /// 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, ArrayRef<std::pair<StringRef, T>> Mapping,
-        T Default, bool IgnoreCase = false) {
-      if (auto ValueOr = get(LocalName, Mapping, IgnoreCase))
+    get(StringRef LocalName, T Default, bool IgnoreCase = false) {
+      if (auto ValueOr = get<T>(LocalName, IgnoreCase))
         return *ValueOr;
       else
         logErrToStdErr(ValueOr.takeError());
       return Default;
     }
 
     /// Read a named option from the ``Context`` and parse it as an
-    /// enum type ``T`` using the \p Mapping provided. If \p IgnoreCase is set,
-    /// it will search the mapping ignoring the case.
+    /// enum type ``T``.
     ///
     /// Reads the option with the check-local name \p LocalName from local or
     /// global ``CheckOptions``. Gets local option first. If local is not
     /// present, falls back to get global option. If global option is not
     /// present either, returns a ``MissingOptionError``. If the key can't be
     /// parsed as a ``T`` returns a ``UnparseableEnumOptionError``.
+    ///
+    /// \ref clang::tidy::OptionEnumMapping must be specialized for ``T`` to
+    /// 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,
-                     ArrayRef<std::pair<StringRef, T>> Mapping,
                      bool IgnoreCase = false) {
-      if (llvm::Expected<int64_t> ValueOr = getEnumInt(
-              LocalName, typeEraseMapping(Mapping), true, IgnoreCase))
+      if (llvm::Expected<int64_t> ValueOr =
+              getEnumInt(LocalName, typeEraseMapping<T>(), true, IgnoreCase))
         return static_cast<T>(*ValueOr);
       else
         return std::move(ValueOr.takeError());
     }
 
     /// Read a named option from the ``Context`` and parse it as an
-    /// enum type ``T`` using the \p Mapping provided. If \p IgnoreCase is set,
-    /// it will search the mapping ignoring the case.
+    /// enum type ``T``.
     ///
     /// Reads the option with the check-local name \p LocalName from local or
     /// global ``CheckOptions``. Gets local option first. If local is not
     /// present, falls back to get global option. If global option is not
     /// present either or it can't be parsed as a ``T``, returns \p Default.
+    ///
+    /// \ref clang::tidy::OptionEnumMapping must be specialized for ``T`` to
+    /// 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,
-                     ArrayRef<std::pair<StringRef, T>> Mapping, T Default,
-                     bool IgnoreCase = false) {
-      if (auto ValueOr = getLocalOrGlobal(LocalName, Mapping, IgnoreCase))
+    getLocalOrGlobal(StringRef LocalName, T Default, bool IgnoreCase = false) {
+      if (auto ValueOr = getLocalOrGlobal<T>(LocalName, IgnoreCase))
         return *ValueOr;
       else
         logErrToStdErr(ValueOr.takeError());
       return Default;
     }
 
     /// 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,
                StringRef Value) const;
 
     /// Stores an option with the check-local name \p LocalName with
     /// ``int64_t`` value \p Value to \p Options.
     void store(ClangTidyOptions::OptionMap &Options, StringRef LocalName,
                int64_t Value) const;
 
     /// Stores an option with the check-local name \p LocalName as the string
-    /// representation of the Enum \p Value using the \p Mapping to \p Options.
+    /// representation of the Enum \p Value to \p Options.
+    ///
+    /// \ref clang::tidy::OptionEnumMapping must be specialized for ``T`` to
+    /// 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,
-          ArrayRef<std::pair<StringRef, T>> Mapping) {
+    store(ClangTidyOptions::OptionMap &Options, StringRef LocalName, T Value) {
+      ArrayRef<std::pair<T, StringRef>> Mapping =
+          OptionEnumMapping<T>::getEnumMapping();
       auto Iter = llvm::find_if(
-          Mapping, [&](const std::pair<StringRef, T> &NameAndEnum) {
-            return NameAndEnum.second == Value;
+          Mapping, [&](const std::pair<T, StringRef> &NameAndEnum) {
+            return NameAndEnum.first == Value;
           });
       assert(Iter != Mapping.end() && "Unknown Case Value");
-      store(Options, LocalName, Iter->first);
+      store(Options, LocalName, Iter->second);
     }
 
   private:
-    using NameAndValue = std::pair<StringRef, int64_t>;
+    using NameAndValue = std::pair<int64_t, StringRef>;
 
     llvm::Expected<int64_t> getEnumInt(StringRef LocalName,
                                        ArrayRef<NameAndValue> Mapping,
                                        bool CheckGlobal, bool IgnoreCase);
 
     template <typename T>
     std::enable_if_t<std::is_enum<T>::value, std::vector<NameAndValue>>
-    typeEraseMapping(ArrayRef<std::pair<StringRef, T>> Mapping) {
+    typeEraseMapping() {
+      ArrayRef<std::pair<T, StringRef>> Mapping =
+          OptionEnumMapping<T>::getEnumMapping();
       std::vector<NameAndValue> Result;
       Result.reserve(Mapping.size());
       for (auto &MappedItem : Mapping) {
-        Result.emplace_back(MappedItem.first,
-                            static_cast<int64_t>(MappedItem.second));
+        Result.emplace_back(static_cast<int64_t>(MappedItem.first),
+                            MappedItem.second);
       }
       return Result;
     }
 
     static void logErrToStdErr(llvm::Error &&Err);
 
     std::string NamePrefix;
     const ClangTidyOptions::OptionMap &CheckOptions;

clang-tools-extra/clang-tidy/ClangTidyCheck.cpp

 
 void ClangTidyCheck::OptionsView::store(ClangTidyOptions::OptionMap &Options,
                                         StringRef LocalName,
                                         int64_t Value) const {
   store(Options, LocalName, llvm::itostr(Value));
 }
 
 llvm::Expected<int64_t> ClangTidyCheck::OptionsView::getEnumInt(
-    StringRef LocalName, ArrayRef<std::pair<StringRef, int64_t>> Mapping,
+    StringRef LocalName, ArrayRef<std::pair<int64_t, StringRef>> Mapping,
     bool CheckGlobal, bool IgnoreCase) {
   auto Iter = CheckOptions.find((NamePrefix + LocalName).str());
   if (CheckGlobal && Iter == CheckOptions.end())
     Iter = CheckOptions.find(LocalName.str());
   if (Iter == CheckOptions.end())
     return llvm::make_error<MissingOptionError>((NamePrefix + LocalName).str());
 
   StringRef Value = Iter->second.Value;
   StringRef Closest;
   unsigned EditDistance = -1;
   for (const auto &NameAndEnum : Mapping) {
     if (IgnoreCase) {
-      if (Value.equals_lower(NameAndEnum.first))
-        return NameAndEnum.second;
-    } else if (Value.equals(NameAndEnum.first)) {
-      return NameAndEnum.second;
-    } else if (Value.equals_lower(NameAndEnum.first)) {
-      Closest = NameAndEnum.first;
+      if (Value.equals_lower(NameAndEnum.second))
+        return NameAndEnum.first;
+    } else if (Value.equals(NameAndEnum.second)) {
+      return NameAndEnum.first;
+    } else if (Value.equals_lower(NameAndEnum.second)) {
+      Closest = NameAndEnum.second;
       EditDistance = 0;
       continue;
     }
-    unsigned Distance = Value.edit_distance(NameAndEnum.first);
+    unsigned Distance = Value.edit_distance(NameAndEnum.second);
     if (Distance < EditDistance) {
       EditDistance = Distance;
-      Closest = NameAndEnum.first;
+      Closest = NameAndEnum.second;
     }
   }
   if (EditDistance < 3)
     return llvm::make_error<UnparseableEnumOptionError>(
         Iter->first, Iter->second.Value, std::string(Closest));
   return llvm::make_error<UnparseableEnumOptionError>(Iter->first,
                                                       Iter->second.Value);
 }

clang-tools-extra/clang-tidy/abseil/StringFindStartswithCheck.cpp

 namespace abseil {
 
 StringFindStartswithCheck::StringFindStartswithCheck(StringRef Name,
                                                      ClangTidyContext *Context)
     : ClangTidyCheck(Name, Context),
       StringLikeClasses(utils::options::parseStringList(
           Options.get("StringLikeClasses", "::std::basic_string"))),
       IncludeStyle(Options.getLocalOrGlobal("IncludeStyle",
-                                            utils::IncludeSorter::getMapping(),
                                             utils::IncludeSorter::IS_LLVM)),
       AbseilStringsMatchHeader(
           Options.get("AbseilStringsMatchHeader", "absl/strings/match.h")) {}
 
 void StringFindStartswithCheck::registerMatchers(MatchFinder *Finder) {
   auto ZeroLiteral = integerLiteral(equals(0));
   auto StringClassMatcher = cxxRecordDecl(hasAnyName(SmallVector<StringRef, 4>(
       StringLikeClasses.begin(), StringLikeClasses.end())));
IncludeInserter = std::make_unique<utils::IncludeInserter>(SM, getLangOpts(),
                                                               IncludeStyle);
   PP->addPPCallbacks(IncludeInserter->CreatePPCallbacks());
 }
 
 void StringFindStartswithCheck::storeOptions(
     ClangTidyOptions::OptionMap &Opts) {
   Options.store(Opts, "StringLikeClasses",
                 utils::options::serializeStringList(StringLikeClasses));
-  Options.store(Opts, "IncludeStyle", IncludeStyle,
-                utils::IncludeSorter::getMapping());
+  Options.store(Opts, "IncludeStyle", IncludeStyle);
   Options.store(Opts, "AbseilStringsMatchHeader", AbseilStringsMatchHeader);
 }
 
 } // namespace abseil
 } // namespace tidy
 } // namespace clang

clang-tools-extra/clang-tidy/cppcoreguidelines/InitVariablesCheck.cpp

 namespace {
 AST_MATCHER(VarDecl, isLocalVarDecl) { return Node.isLocalVarDecl(); }
 } // namespace
 
 InitVariablesCheck::InitVariablesCheck(StringRef Name,
                                        ClangTidyContext *Context)
     : ClangTidyCheck(Name, Context),
       IncludeStyle(Options.getLocalOrGlobal("IncludeStyle",
-                                            utils::IncludeSorter::getMapping(),
                                             utils::IncludeSorter::IS_LLVM)),
       MathHeader(Options.get("MathHeader", "math.h")) {}
 
 void InitVariablesCheck::storeOptions(ClangTidyOptions::OptionMap &Opts) {
-  Options.store(Opts, "IncludeStyle", IncludeStyle,
-                utils::IncludeSorter::getMapping());
+  Options.store(Opts, "IncludeStyle", IncludeStyle);
   Options.store(Opts, "MathHeader", MathHeader);
 }
 
 void InitVariablesCheck::registerMatchers(MatchFinder *Finder) {
   std::string BadDecl = "badDecl";
   Finder->addMatcher(
       varDecl(unless(hasInitializer(anything())), unless(isInstantiated()),
               isLocalVarDecl(), unless(isStaticLocal()), isDefinition(),

clang-tools-extra/clang-tidy/cppcoreguidelines/ProBoundsConstantArrayIndexCheck.cpp

 namespace clang {
 namespace tidy {
 namespace cppcoreguidelines {
 
 ProBoundsConstantArrayIndexCheck::ProBoundsConstantArrayIndexCheck(
     StringRef Name, ClangTidyContext *Context)
     : ClangTidyCheck(Name, Context), GslHeader(Options.get("GslHeader", "")),
       IncludeStyle(Options.getLocalOrGlobal("IncludeStyle",
-                                            utils::IncludeSorter::getMapping(),
                                             utils::IncludeSorter::IS_LLVM)) {}
 
 void ProBoundsConstantArrayIndexCheck::storeOptions(
     ClangTidyOptions::OptionMap &Opts) {
   Options.store(Opts, "GslHeader", GslHeader);
   Options.store(Opts, "IncludeStyle", IncludeStyle);
 }
 
 void ProBoundsConstantArrayIndexCheck::registerPPCallbacks(
     const SourceManager &SM, Preprocessor *PP, Preprocessor *ModuleExpanderPP) {
   Inserter = std::make_unique<utils::IncludeInserter>(SM, getLangOpts(),
                                                        IncludeStyle);
   PP->addPPCallbacks(Inserter->CreatePPCallbacks());
 }

clang-tools-extra/clang-tidy/modernize/LoopConvertCheck.cpp

 #include <cstring>
 #include <utility>
 
 using namespace clang::ast_matchers;
 using namespace llvm;
 
 namespace clang {
 namespace tidy {
+
+template <> struct OptionEnumMapping<modernize::Confidence::Level> {
+  static llvm::ArrayRef<std::pair<modernize::Confidence::Level, StringRef>>
+  getEnumMapping() {
+    static constexpr std::pair<modernize::Confidence::Level, StringRef>
+        Mapping[] = {{modernize::Confidence::CL_Reasonable, "reasonable"},
+                     {modernize::Confidence::CL_Safe, "safe"},
+                     {modernize::Confidence::CL_Risky, "risky"}};
+    return makeArrayRef(Mapping);
+  }
+};
+
+template <> struct OptionEnumMapping<modernize::VariableNamer::NamingStyle> {
+  static llvm::ArrayRef<
+      std::pair<modernize::VariableNamer::NamingStyle, StringRef>>
+  getEnumMapping() {
+    static constexpr std::pair<modernize::VariableNamer::NamingStyle, StringRef>
+        Mapping[] = {{modernize::VariableNamer::NS_CamelCase, "CamelCase"},
+                     {modernize::VariableNamer::NS_CamelBack, "camelBack"},
+                     {modernize::VariableNamer::NS_LowerCase, "lower_case"},
+                     {modernize::VariableNamer::NS_UpperCase, "UPPER_CASE"}};
+    return makeArrayRef(Mapping);
+  }
+};
+
 namespace modernize {
 
 static const char LoopNameArray[] = "forLoopArray";
 static const char LoopNameIterator[] = "forLoopIterator";
 static const char LoopNamePseudoArray[] = "forLoopPseudoArray";
 static const char ConditionBoundName[] = "conditionBound";
 static const char ConditionVarName[] = "conditionVar";
 static const char IncrementVarName[] = "incrementVar";
 static const char InitVarName[] = "initVar";
 static const char BeginCallName[] = "beginCall";
 static const char EndCallName[] = "endCall";
 static const char ConditionEndVarName[] = "conditionEndVar";
 static const char EndVarName[] = "endVar";
 static const char DerefByValueResultName[] = "derefByValueResult";
 static const char DerefByRefResultName[] = "derefByRefResult";
 
-static ArrayRef<std::pair<StringRef, Confidence::Level>>
-getConfidenceMapping() {
-  static constexpr std::pair<StringRef, Confidence::Level> Mapping[] = {
-      {"reasonable", Confidence::CL_Reasonable},
-      {"safe", Confidence::CL_Safe},
-      {"risky", Confidence::CL_Risky}};
-  return makeArrayRef(Mapping);
-}
-
-static ArrayRef<std::pair<StringRef, VariableNamer::NamingStyle>>
-getStyleMapping() {
-  static constexpr std::pair<StringRef, VariableNamer::NamingStyle> Mapping[] =
-      {{"CamelCase", VariableNamer::NS_CamelCase},
-       {"camelBack", VariableNamer::NS_CamelBack},
-       {"lower_case", VariableNamer::NS_LowerCase},
-       {"UPPER_CASE", VariableNamer::NS_UpperCase}};
-  return makeArrayRef(Mapping);
-}
-
 // shared matchers
 static const TypeMatcher AnyType() { return anything(); }
 
 static const StatementMatcher IntegerComparisonMatcher() {
   return expr(ignoringParenImpCasts(
       declRefExpr(to(varDecl(hasType(isInteger())).bind(ConditionVarName)))));
 }
 

 
 LoopConvertCheck::RangeDescriptor::RangeDescriptor()
     : ContainerNeedsDereference(false), DerefByConstRef(false),
       DerefByValue(false) {}
 
 LoopConvertCheck::LoopConvertCheck(StringRef Name, ClangTidyContext *Context)
     : ClangTidyCheck(Name, Context), TUInfo(new TUTrackingInfo),
       MaxCopySize(Options.get("MaxCopySize", 16ULL)),
-      MinConfidence(Options.get("MinConfidence", getConfidenceMapping(),
-                                Confidence::CL_Reasonable)),
-      NamingStyle(Options.get("NamingStyle", getStyleMapping(),
-                              VariableNamer::NS_CamelCase)) {}
+      MinConfidence(Options.get("MinConfidence", Confidence::CL_Reasonable)),
+      NamingStyle(Options.get("NamingStyle", VariableNamer::NS_CamelCase)) {}
 
 void LoopConvertCheck::storeOptions(ClangTidyOptions::OptionMap &Opts) {
   Options.store(Opts, "MaxCopySize", std::to_string(MaxCopySize));
-  Options.store(Opts, "MinConfidence", MinConfidence, getConfidenceMapping());
-  Options.store(Opts, "NamingStyle", NamingStyle, getStyleMapping());
+  Options.store(Opts, "MinConfidence", MinConfidence);
+  Options.store(Opts, "NamingStyle", NamingStyle);
 }
 
 void LoopConvertCheck::registerMatchers(MatchFinder *Finder) {
   Finder->addMatcher(traverse(ast_type_traits::TK_AsIs, makeArrayLoopMatcher()),
                      this);
   Finder->addMatcher(
       traverse(ast_type_traits::TK_AsIs, makeIteratorLoopMatcher()), this);
   Finder->addMatcher(

clang-tools-extra/clang-tidy/modernize/MakeSmartPtrCheck.cpp

 } // namespace
 
 const char MakeSmartPtrCheck::PointerType[] = "pointerType";
 
 MakeSmartPtrCheck::MakeSmartPtrCheck(StringRef Name, ClangTidyContext *Context,
                                      StringRef MakeSmartPtrFunctionName)
     : ClangTidyCheck(Name, Context),
       IncludeStyle(Options.getLocalOrGlobal("IncludeStyle",
-                                            utils::IncludeSorter::getMapping(),
                                             utils::IncludeSorter::IS_LLVM)),
       MakeSmartPtrFunctionHeader(
           Options.get("MakeSmartPtrFunctionHeader", StdMemoryHeader)),
       MakeSmartPtrFunctionName(
           Options.get("MakeSmartPtrFunction", MakeSmartPtrFunctionName)),
       IgnoreMacros(Options.getLocalOrGlobal("IgnoreMacros", true)) {}
 
 void MakeSmartPtrCheck::storeOptions(ClangTidyOptions::OptionMap &Opts) {
-  Options.store(Opts, "IncludeStyle", IncludeStyle,
-                utils::IncludeSorter::getMapping());
+  Options.store(Opts, "IncludeStyle", IncludeStyle);
   Options.store(Opts, "MakeSmartPtrFunctionHeader", MakeSmartPtrFunctionHeader);
   Options.store(Opts, "MakeSmartPtrFunction", MakeSmartPtrFunctionName);
   Options.store(Opts, "IgnoreMacros", IgnoreMacros);
 }
 
 bool MakeSmartPtrCheck::isLanguageVersionSupported(
     const LangOptions &LangOpts) const {
   return LangOpts.CPlusPlus11;

clang-tools-extra/clang-tidy/modernize/PassByValueCheck.cpp

collectParamDecls(const CXXConstructorDecl *Ctor,
   for (const FunctionDecl *Redecl : Ctor->redecls())
     Results.push_back(Redecl->getParamDecl(ParamIdx));
   return Results;
 }
 
 PassByValueCheck::PassByValueCheck(StringRef Name, ClangTidyContext *Context)
     : ClangTidyCheck(Name, Context),
       IncludeStyle(Options.getLocalOrGlobal("IncludeStyle",
-                                            utils::IncludeSorter::getMapping(),
                                             utils::IncludeSorter::IS_LLVM)),
       ValuesOnly(Options.get("ValuesOnly", false)) {}
 
 void PassByValueCheck::storeOptions(ClangTidyOptions::OptionMap &Opts) {
-  Options.store(Opts, "IncludeStyle", IncludeStyle,
-                utils::IncludeSorter::getMapping());
+  Options.store(Opts, "IncludeStyle", IncludeStyle);
   Options.store(Opts, "ValuesOnly", ValuesOnly);
 }
 
 void PassByValueCheck::registerMatchers(MatchFinder *Finder) {
   Finder->addMatcher(
       traverse(
           ast_type_traits::TK_AsIs,
           cxxConstructorDecl(

clang-tools-extra/clang-tidy/modernize/ReplaceAutoPtrCheck.cpp

 }
 
 } // namespace
 
 ReplaceAutoPtrCheck::ReplaceAutoPtrCheck(StringRef Name,
                                          ClangTidyContext *Context)
     : ClangTidyCheck(Name, Context),
       IncludeStyle(Options.getLocalOrGlobal("IncludeStyle",
-                                            utils::IncludeSorter::getMapping(),
                                             utils::IncludeSorter::IS_LLVM)) {}
 
 void ReplaceAutoPtrCheck::storeOptions(ClangTidyOptions::OptionMap &Opts) {
-  Options.store(Opts, "IncludeStyle", IncludeStyle,
-                utils::IncludeSorter::getMapping());
+  Options.store(Opts, "IncludeStyle", IncludeStyle);
 }
 
 void ReplaceAutoPtrCheck::registerMatchers(MatchFinder *Finder) {
   auto AutoPtrDecl = recordDecl(hasName("auto_ptr"), isFromStdNamespace());
   auto AutoPtrType = qualType(hasDeclaration(AutoPtrDecl));
 
   //   std::auto_ptr<int> a;
   //        ^~~~~~~~~~~~~

clang-tools-extra/clang-tidy/modernize/ReplaceRandomShuffleCheck.cpp

 namespace clang {
 namespace tidy {
 namespace modernize {
 
 ReplaceRandomShuffleCheck::ReplaceRandomShuffleCheck(StringRef Name,
                                                      ClangTidyContext *Context)
     : ClangTidyCheck(Name, Context),
       IncludeStyle(Options.getLocalOrGlobal("IncludeStyle",
-                                            utils::IncludeSorter::getMapping(),
                                             utils::IncludeSorter::IS_LLVM)) {}
 
 void ReplaceRandomShuffleCheck::registerMatchers(MatchFinder *Finder) {
   const auto Begin = hasArgument(0, expr());
   const auto End = hasArgument(1, expr());
   const auto RandomFunc = hasArgument(2, expr().bind("randomFunc"));
   Finder->addMatcher(
       traverse(
void ReplaceRandomShuffleCheck::registerPPCallbacks(
     const SourceManager &SM, Preprocessor *PP, Preprocessor *ModuleExpanderPP) {
   IncludeInserter = std::make_unique<utils::IncludeInserter>(SM, getLangOpts(),
                                                               IncludeStyle);
   PP->addPPCallbacks(IncludeInserter->CreatePPCallbacks());
 }
 
 void ReplaceRandomShuffleCheck::storeOptions(
     ClangTidyOptions::OptionMap &Opts) {
-  Options.store(Opts, "IncludeStyle", IncludeStyle,
-                utils::IncludeSorter::getMapping());
+  Options.store(Opts, "IncludeStyle", IncludeStyle);
 }
 
 void ReplaceRandomShuffleCheck::check(const MatchFinder::MatchResult &Result) {
   const auto *MatchedDecl = Result.Nodes.getNodeAs<DeclRefExpr>("name");
   const auto *MatchedArgumentThree = Result.Nodes.getNodeAs<Expr>("randomFunc");
   const auto *MatchedCallExpr = Result.Nodes.getNodeAs<CallExpr>("match");
 
   if (MatchedCallExpr->getBeginLoc().isMacroID())

clang-tools-extra/clang-tidy/performance/MoveConstructorInitCheck.cpp

 namespace clang {
 namespace tidy {
 namespace performance {
 
 MoveConstructorInitCheck::MoveConstructorInitCheck(StringRef Name,
                                                    ClangTidyContext *Context)
     : ClangTidyCheck(Name, Context),
       IncludeStyle(Options.getLocalOrGlobal("IncludeStyle",
-                                            utils::IncludeSorter::getMapping(),
                                             utils::IncludeSorter::IS_LLVM)) {}
 
 void MoveConstructorInitCheck::registerMatchers(MatchFinder *Finder) {
   Finder->addMatcher(
       traverse(ast_type_traits::TK_AsIs,
                cxxConstructorDecl(
                    unless(isImplicit()), isMoveConstructor(),
                    hasAnyConstructorInitializer(

 void MoveConstructorInitCheck::registerPPCallbacks(
     const SourceManager &SM, Preprocessor *PP, Preprocessor *ModuleExpanderPP) {
   Inserter = std::make_unique<utils::IncludeInserter>(SM, getLangOpts(),
                                                        IncludeStyle);
   PP->addPPCallbacks(Inserter->CreatePPCallbacks());
 }
 
 void MoveConstructorInitCheck::storeOptions(ClangTidyOptions::OptionMap &Opts) {
-  Options.store(Opts, "IncludeStyle", IncludeStyle,
-                utils::IncludeSorter::getMapping());
+  Options.store(Opts, "IncludeStyle", IncludeStyle);
 }
 
 } // namespace performance
 } // namespace tidy
 } // namespace clang

clang-tools-extra/clang-tidy/performance/TypePromotionInMathFnCheck.cpp

AST_MATCHER_P(Type, isBuiltinType, BuiltinType::Kind, Kind) {
   return false;
 }
 } // anonymous namespace
 
 TypePromotionInMathFnCheck::TypePromotionInMathFnCheck(
     StringRef Name, ClangTidyContext *Context)
     : ClangTidyCheck(Name, Context),
       IncludeStyle(Options.getLocalOrGlobal("IncludeStyle",
-                                            utils::IncludeSorter::getMapping(),
                                             utils::IncludeSorter::IS_LLVM)) {}
 
 void TypePromotionInMathFnCheck::registerPPCallbacks(
     const SourceManager &SM, Preprocessor *PP, Preprocessor *ModuleExpanderPP) {
   IncludeInserter = std::make_unique<utils::IncludeInserter>(SM, getLangOpts(),
                                                               IncludeStyle);
   PP->addPPCallbacks(IncludeInserter->CreatePPCallbacks());
 }
 
 void TypePromotionInMathFnCheck::storeOptions(
     ClangTidyOptions::OptionMap &Opts) {
-  Options.store(Opts, "IncludeStyle", IncludeStyle,
-                utils::IncludeSorter::getMapping());
+  Options.store(Opts, "IncludeStyle", IncludeStyle);
 }
 
 void TypePromotionInMathFnCheck::registerMatchers(MatchFinder *Finder) {
   constexpr BuiltinType::Kind IntTy = BuiltinType::Int;
   constexpr BuiltinType::Kind LongTy = BuiltinType::Long;
   constexpr BuiltinType::Kind FloatTy = BuiltinType::Float;
   constexpr BuiltinType::Kind DoubleTy = BuiltinType::Double;
   constexpr BuiltinType::Kind LongDoubleTy = BuiltinType::LongDouble;

clang-tools-extra/clang-tidy/performance/UnnecessaryValueParamCheck.cpp

 }
 
 } // namespace
 
 UnnecessaryValueParamCheck::UnnecessaryValueParamCheck(
     StringRef Name, ClangTidyContext *Context)
     : ClangTidyCheck(Name, Context),
       IncludeStyle(Options.getLocalOrGlobal("IncludeStyle",
-                                            utils::IncludeSorter::getMapping(),
                                             utils::IncludeSorter::IS_LLVM)),
       AllowedTypes(
           utils::options::parseStringList(Options.get("AllowedTypes", ""))) {}
 
 void UnnecessaryValueParamCheck::registerMatchers(MatchFinder *Finder) {
   const auto ExpensiveValueParamDecl = parmVarDecl(
       hasType(qualType(
           hasCanonicalType(matchers::isExpensiveToCopy()),
void UnnecessaryValueParamCheck::registerPPCallbacks(
     const SourceManager &SM, Preprocessor *PP, Preprocessor *ModuleExpanderPP) {
   Inserter = std::make_unique<utils::IncludeInserter>(SM, getLangOpts(),
                                                       IncludeStyle);
   PP->addPPCallbacks(Inserter->CreatePPCallbacks());
 }
 
 void UnnecessaryValueParamCheck::storeOptions(
     ClangTidyOptions::OptionMap &Opts) {
-  Options.store(Opts, "IncludeStyle", IncludeStyle,
-                utils::IncludeSorter::getMapping());
+  Options.store(Opts, "IncludeStyle", IncludeStyle);
   Options.store(Opts, "AllowedTypes",
                 utils::options::serializeStringList(AllowedTypes));
 }
 
 void UnnecessaryValueParamCheck::onEndOfTranslationUnit() {
   MutationAnalyzers.clear();
 }
 

clang-tools-extra/clang-tidy/readability/IdentifierNamingCheck.h

DiagInfo GetDiagInfo(const NamingCheckId &ID,
                        const NamingCheckFailure &Failure) const override;
 
   std::vector<llvm::Optional<NamingStyle>> NamingStyles;
   const bool IgnoreFailedSplit;
   const bool IgnoreMainLikeFunctions;
 };
 
 } // namespace readability
+template <>
+struct OptionEnumMapping<readability::IdentifierNamingCheck::CaseType> {
+  static llvm::ArrayRef<
+      std::pair<readability::IdentifierNamingCheck::CaseType, StringRef>>
+  getEnumMapping();
+};
 } // namespace tidy
 } // namespace clang
 
 #endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_READABILITY_IDENTIFIERNAMINGCHECK_H

clang-tools-extra/clang-tidy/readability/IdentifierNamingCheck.cpp

 #define DEBUG_TYPE "clang-tidy"
 
 // FixItHint
 
 using namespace clang::ast_matchers;
 
 namespace clang {
 namespace tidy {
+
+llvm::ArrayRef<
+    std::pair<readability::IdentifierNamingCheck::CaseType, StringRef>>
+OptionEnumMapping<
+    readability::IdentifierNamingCheck::CaseType>::getEnumMapping() {
+  static constexpr std::pair<readability::IdentifierNamingCheck::CaseType,
+                             StringRef>
+      Mapping[] = {
+          {readability::IdentifierNamingCheck::CT_AnyCase, "aNy_CasE"},
+          {readability::IdentifierNamingCheck::CT_LowerCase, "lower_case"},
+          {readability::IdentifierNamingCheck::CT_UpperCase, "UPPER_CASE"},
+          {readability::IdentifierNamingCheck::CT_CamelBack, "camelBack"},
+          {readability::IdentifierNamingCheck::CT_CamelCase, "CamelCase"},
+          {readability::IdentifierNamingCheck::CT_CamelSnakeCase,
+           "Camel_Snake_Case"},
+          {readability::IdentifierNamingCheck::CT_CamelSnakeBack,
+           "camel_Snake_Back"}};
+  return llvm::makeArrayRef(Mapping);
+}
+
 namespace readability {
 
 // clang-format off
 #define NAMING_KEYS(m) \
     m(Namespace) \
     m(InlineNamespace) \
     m(EnumConstant) \
     m(ConstexprVariable) \

 #define STRINGIZE(v) #v,
   NAMING_KEYS(STRINGIZE)
 #undef STRINGIZE
 };
 
 #undef NAMING_KEYS
 // clang-format on
 
-static constexpr std::pair<StringRef, IdentifierNamingCheck::CaseType>
-    Mapping[] = {
-        {"aNy_CasE", IdentifierNamingCheck::CT_AnyCase},
-        {"lower_case", IdentifierNamingCheck::CT_LowerCase},
-        {"UPPER_CASE", IdentifierNamingCheck::CT_UpperCase},
-        {"camelBack", IdentifierNamingCheck::CT_CamelBack},
-        {"CamelCase", IdentifierNamingCheck::CT_CamelCase},
-        {"Camel_Snake_Case", IdentifierNamingCheck::CT_CamelSnakeCase},
-        {"camel_Snake_Back", IdentifierNamingCheck::CT_CamelSnakeBack}};
-
 IdentifierNamingCheck::IdentifierNamingCheck(StringRef Name,
                                              ClangTidyContext *Context)
     : RenamerClangTidyCheck(Name, Context),
       IgnoreFailedSplit(Options.get("IgnoreFailedSplit", false)),
       IgnoreMainLikeFunctions(Options.get("IgnoreMainLikeFunctions", false)) {
 
   for (auto const &Name : StyleNames) {
     auto CaseOptional = [&]() -> llvm::Optional<CaseType> {
-      auto ValueOr = Options.get((Name + "Case").str(), makeArrayRef(Mapping));
+      auto ValueOr = Options.get<CaseType>((Name + "Case").str());
       if (ValueOr)
         return *ValueOr;
       llvm::logAllUnhandledErrors(
           llvm::handleErrors(ValueOr.takeError(),
                              [](const MissingOptionError &) -> llvm::Error {
                                return llvm::Error::success();
                              }),
           llvm::errs(), "warning: ");

 IdentifierNamingCheck::~IdentifierNamingCheck() = default;
 
 void IdentifierNamingCheck::storeOptions(ClangTidyOptions::OptionMap &Opts) {
   RenamerClangTidyCheck::storeOptions(Opts);
   for (size_t i = 0; i < SK_Count; ++i) {
     if (NamingStyles[i]) {
       if (NamingStyles[i]->Case) {
         Options.store(Opts, (StyleNames[i] + "Case").str(),
-                      *NamingStyles[i]->Case, llvm::makeArrayRef(Mapping));
+                      *NamingStyles[i]->Case);
       }
       Options.store(Opts, (StyleNames[i] + "Prefix").str(),
                     NamingStyles[i]->Prefix);
       Options.store(Opts, (StyleNames[i] + "Suffix").str(),
                     NamingStyles[i]->Suffix);
     }
   }
 

clang-tools-extra/clang-tidy/utils/IncludeSorter.h

 /// inclusions in a given source file being processed and generate the necessary
 /// commands to sort the inclusions according to the precedence encoded in
 /// ``IncludeKinds``.
 class IncludeSorter {
 public:
   /// Supported include styles.
   enum IncludeStyle { IS_LLVM = 0, IS_Google = 1 };
 
-  static ArrayRef<std::pair<StringRef, IncludeStyle>> getMapping();
-
   /// The classifications of inclusions, in the order they should be sorted.
   enum IncludeKinds {
     IK_MainTUInclude = 0,    ///< e.g. ``#include "foo.h"`` when editing foo.cc
     IK_CSystemInclude = 1,   ///< e.g. ``#include <stdio.h>``
     IK_CXXSystemInclude = 2, ///< e.g. ``#include <vector>``
     IK_NonSystemInclude = 3, ///< e.g. ``#include "bar.h"``
     IK_InvalidInclude = 4    ///< total number of valid ``IncludeKind``s
   };
private:
   SourceRangeVector SourceLocations;
   /// Mapping from file name to #include locations.
   llvm::StringMap<SourceRangeVector> IncludeLocations;
   /// Includes sorted into buckets.
   SmallVector<std::string, 1> IncludeBucket[IK_InvalidInclude];
 };
 
 } // namespace utils
+
+template <> struct OptionEnumMapping<utils::IncludeSorter::IncludeStyle> {
+  static ArrayRef<std::pair<utils::IncludeSorter::IncludeStyle, StringRef>>
+  getEnumMapping();
+};
 } // namespace tidy
 } // namespace clang
 #endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_INCLUDESORTER_H

clang-tools-extra/clang-tidy/utils/IncludeSorter.cpp

Optional<FixItHint> IncludeSorter::CreateIncludeInsertion(StringRef FileName,
   // Create a block before.
   const std::string &FirstInclude = IncludeBucket[NonEmptyKind][0];
   SourceRange FirstIncludeLocation = IncludeLocations[FirstInclude].back();
   IncludeStmt.append("\n");
   return FixItHint::CreateInsertion(FirstIncludeLocation.getBegin(),
                                     IncludeStmt);
 }
 
-llvm::ArrayRef<std::pair<StringRef, IncludeSorter::IncludeStyle>>
-IncludeSorter::getMapping() {
-  static constexpr std::pair<StringRef, IncludeSorter::IncludeStyle> Mapping[] =
-      {{"llvm", IS_LLVM}, {"google", IS_Google}};
+} // namespace utils
+
+llvm::ArrayRef<std::pair<utils::IncludeSorter::IncludeStyle, StringRef>>
+OptionEnumMapping<utils::IncludeSorter::IncludeStyle>::getEnumMapping() {
+  static constexpr std::pair<utils::IncludeSorter::IncludeStyle, StringRef>
+      Mapping[] = {{utils::IncludeSorter::IS_LLVM, "llvm"},
+                   {utils::IncludeSorter::IS_Google, "google"}};
   return makeArrayRef(Mapping);
 }
-
-} // namespace utils
 } // namespace tidy
 } // namespace clang

clang-tools-extra/clang-tidy/utils/TransformerClangTidyCheck.cpp

 // `ClangTidyCheck` instance was properly initialized.
 TransformerClangTidyCheck::TransformerClangTidyCheck(
     std::function<Optional<RewriteRule>(const LangOptions &,
                                         const OptionsView &)>
         MakeRule,
     StringRef Name, ClangTidyContext *Context)
     : ClangTidyCheck(Name, Context), Rule(MakeRule(getLangOpts(), Options)),
       IncludeStyle(Options.getLocalOrGlobal("IncludeStyle",
-                                            IncludeSorter::getMapping(),
                                             IncludeSorter::IS_LLVM)) {
   if (Rule)
     assert(llvm::all_of(Rule->Cases, hasExplanation) &&
            "clang-tidy checks must have an explanation by default;"
            " explicitly provide an empty explanation if none is desired");
 }
 
 TransformerClangTidyCheck::TransformerClangTidyCheck(RewriteRule R,
                                                      StringRef Name,
                                                      ClangTidyContext *Context)
     : ClangTidyCheck(Name, Context), Rule(std::move(R)),
       IncludeStyle(Options.getLocalOrGlobal("IncludeStyle",
-                                            IncludeSorter::getMapping(),
                                             IncludeSorter::IS_LLVM)) {
   assert(llvm::all_of(Rule->Cases, hasExplanation) &&
          "clang-tidy checks must have an explanation by default;"
          " explicitly provide an empty explanation if none is desired");
 }
 
 void TransformerClangTidyCheck::registerPPCallbacks(
     const SourceManager &SM, Preprocessor *PP, Preprocessor *ModuleExpanderPP) {
for (const auto &I : Case.AddedIncludes) {
     Diag << Inserter->CreateIncludeInsertion(
         Result.SourceManager->getMainFileID(), I.first,
         /*IsAngled=*/I.second == transformer::IncludeFormat::Angled);
   }
 }
 
 void TransformerClangTidyCheck::storeOptions(
     ClangTidyOptions::OptionMap &Opts) {
-  Options.store(Opts, "IncludeStyle", IncludeStyle,
-                IncludeSorter::getMapping());
+  Options.store(Opts, "IncludeStyle", IncludeStyle);
 }
 
 } // namespace utils
 } // namespace tidy
 } // namespace clang

clang-tools-extra/unittests/clang-tidy/ClangTidyDiagnosticConsumerTest.cpp

 #include "ClangTidy.h"
 #include "ClangTidyTest.h"
 #include "gtest/gtest.h"
 
+using namespace clang::ast_matchers;
+
 namespace clang {
 namespace tidy {
 namespace test {
 
 class TestCheck : public ClangTidyCheck {
 public:
   TestCheck(StringRef Name, ClangTidyContext *Context)
       : ClangTidyCheck(Name, Context) {}
-  void registerMatchers(ast_matchers::MatchFinder *Finder) override {
-    Finder->addMatcher(ast_matchers::varDecl().bind("var"), this);
+  void registerMatchers(MatchFinder *Finder) override {
+    Finder->addMatcher(varDecl().bind("var"), this);
+    DidRegister = true;
   }
-  void check(const ast_matchers::MatchFinder::MatchResult &Result) override {
+  void check(const MatchFinder::MatchResult &Result) override {
     const auto *Var = Result.Nodes.getNodeAs<VarDecl>("var");
+
+    assert(Var && "Node isn't bound");
+    DidFire = true;
+
     // Add diagnostics in the wrong order.
     diag(Var->getLocation(), "variable");
     diag(Var->getTypeSpecStartLoc(), "type specifier");
   }
+
+  ~TestCheck() {
+    assert(DidRegister && "Check never registered");
+    assert(DidFire && "Check never fired");
+  }
+
+private:
+  bool DidRegister = false;
+  bool DidFire = false;
 };
 
 TEST(ClangTidyDiagnosticConsumer, SortsErrors) {
   std::vector<ClangTidyError> Errors;
   runCheckOnCode<TestCheck>("int a;", &Errors);
-  EXPECT_EQ(2ul, Errors.size());
+  EXPECT_EQ(2u, Errors.size());
   EXPECT_EQ("type specifier", Errors[0].Message.Message);
   EXPECT_EQ("variable", Errors[1].Message.Message);
 }
 
 } // namespace test
 } // namespace tidy
 } // namespace clang

clang-tools-extra/unittests/clang-tidy/ClangTidyOptionsTest.cpp

 #include "ClangTidyOptions.h"
 #include "ClangTidyCheck.h"
 #include "ClangTidyDiagnosticConsumer.h"
 #include "llvm/ADT/StringExtras.h"
 #include "gtest/gtest.h"
 
 namespace clang {
 namespace tidy {
+
+enum class Colours { Red, Orange, Yellow, Green, Blue, Indigo, Violet };
+
+template <> struct OptionEnumMapping<Colours> {
+  static llvm::ArrayRef<std::pair<Colours, StringRef>> getEnumMapping() {
+    static constexpr std::pair<Colours, StringRef> Mapping[] = {
+        {Colours::Red, "Red"},       {Colours::Orange, "Orange"},
+        {Colours::Yellow, "Yellow"}, {Colours::Green, "Green"},
+        {Colours::Blue, "Blue"},     {Colours::Indigo, "Indigo"},
+        {Colours::Violet, "Violet"}};
+    return makeArrayRef(Mapping);
+  }
+};
+
 namespace test {
 
 TEST(ParseLineFilter, EmptyFilter) {
   ClangTidyGlobalOptions Options;
   EXPECT_FALSE(parseLineFilter("", Options));
   EXPECT_TRUE(Options.LineFilter.empty());
   EXPECT_FALSE(parseLineFilter("[]", Options));
   EXPECT_TRUE(Options.LineFilter.empty());
CHECK_ERROR_INT(TestCheck.getIntLocal<bool>("BoolUnparseable"),
                   "'test.BoolUnparseable'; expected a bool");
   CHECK_ERROR_INT(TestCheck.getIntLocal<bool>("BoolCaseMismatch"),
                   "invalid configuration value 'True' for option "
                   "'test.BoolCaseMismatch'; expected a bool");
 
 #undef CHECK_ERROR_INT
 }
 
 TEST(ValidConfiguration, ValidEnumOptions) {
-
-  enum class Colours { Red, Orange, Yellow, Green, Blue, Indigo, Violet };
-  static constexpr std::pair<StringRef, Colours> Mapping[] = {
-      {"Red", Colours::Red},       {"Orange", Colours::Orange},
-      {"Yellow", Colours::Yellow}, {"Green", Colours::Green},
-      {"Blue", Colours::Blue},     {"Indigo", Colours::Indigo},
-      {"Violet", Colours::Violet}};
-  static const auto Map = makeArrayRef(Mapping);
-
   ClangTidyOptions Options;
   auto &CheckOptions = Options.CheckOptions;
 
   CheckOptions["test.Valid"] = "Red";
   CheckOptions["test.Invalid"] = "Scarlet";
   CheckOptions["test.ValidWrongCase"] = "rED";
   CheckOptions["test.NearMiss"] = "Oragne";
   CheckOptions["GlobalValid"] = "Violet";
   CheckOptions["GlobalInvalid"] = "Purple";
   CheckOptions["GlobalValidWrongCase"] = "vIOLET";
   CheckOptions["GlobalNearMiss"] = "Yelow";
 
   ClangTidyContext Context(std::make_unique<DefaultOptionsProvider>(
       ClangTidyGlobalOptions(), Options));
   TestCheck TestCheck(&Context);
 
 #define CHECK_ERROR_ENUM(Name, Expected)                                       \
   CHECK_ERROR(Name, UnparseableEnumOptionError, Expected)
 
-  CHECK_VAL(TestCheck.getLocal("Valid", Map), Colours::Red);
-  CHECK_VAL(TestCheck.getGlobal("GlobalValid", Map), Colours::Violet);
-  CHECK_VAL(TestCheck.getLocal("ValidWrongCase", Map, /*IgnoreCase*/ true),
-            Colours::Red);
+  CHECK_VAL(TestCheck.getIntLocal<Colours>("Valid"), Colours::Red);
+  CHECK_VAL(TestCheck.getIntGlobal<Colours>("GlobalValid"), Colours::Violet);
   CHECK_VAL(
-      TestCheck.getGlobal("GlobalValidWrongCase", Map, /*IgnoreCase*/ true),
+      TestCheck.getIntLocal<Colours>("ValidWrongCase", /*IgnoreCase*/ true),
+      Colours::Red);
+  CHECK_VAL(TestCheck.getIntGlobal<Colours>("GlobalValidWrongCase",
+                                            /*IgnoreCase*/ true),
             Colours::Violet);
-  CHECK_ERROR_ENUM(TestCheck.getLocal("Invalid", Map),
+  CHECK_ERROR_ENUM(TestCheck.getIntLocal<Colours>("Invalid"),
                    "invalid configuration value "
                    "'Scarlet' for option 'test.Invalid'");
-  CHECK_ERROR_ENUM(TestCheck.getLocal("ValidWrongCase", Map),
+  CHECK_ERROR_ENUM(TestCheck.getIntLocal<Colours>("ValidWrongCase"),
                    "invalid configuration value 'rED' for option "
                    "'test.ValidWrongCase'; did you mean 'Red'?");
-  CHECK_ERROR_ENUM(TestCheck.getLocal("NearMiss", Map),
+  CHECK_ERROR_ENUM(TestCheck.getIntLocal<Colours>("NearMiss"),
                    "invalid configuration value 'Oragne' for option "
                    "'test.NearMiss'; did you mean 'Orange'?");
-  CHECK_ERROR_ENUM(TestCheck.getGlobal("GlobalInvalid", Map),
+  CHECK_ERROR_ENUM(TestCheck.getIntGlobal<Colours>("GlobalInvalid"),
                    "invalid configuration value "
                    "'Purple' for option 'GlobalInvalid'");
-  CHECK_ERROR_ENUM(TestCheck.getGlobal("GlobalValidWrongCase", Map),
+  CHECK_ERROR_ENUM(TestCheck.getIntGlobal<Colours>("GlobalValidWrongCase"),
                    "invalid configuration value 'vIOLET' for option "
                    "'GlobalValidWrongCase'; did you mean 'Violet'?");
-  CHECK_ERROR_ENUM(TestCheck.getGlobal("GlobalNearMiss", Map),
+  CHECK_ERROR_ENUM(TestCheck.getIntGlobal<Colours>("GlobalNearMiss"),
                    "invalid configuration value 'Yelow' for option "
                    "'GlobalNearMiss'; did you mean 'Yellow'?");
 
 #undef CHECK_ERROR_ENUM
 }
 
 #undef CHECK_VAL
 #undef CHECK_ERROR
 
 } // namespace test
 } // namespace tidy
 } // namespace clang