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

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.

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D82188

Author: njames93

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

@@ -158,7 +158,7 @@ void ClangTidyCheck::OptionsView::store(ClangTidyOptions::OptionMap &Options,
 }
 
 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())
@@ -171,19 +171,19 @@ llvm::Expected<int64_t> ClangTidyCheck::OptionsView::getEnumInt(
   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)

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

@@ -27,6 +27,13 @@ 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();
@@ -313,77 +320,80 @@ class ClangTidyCheck : public ast_matchers::MatchFinder::MatchCallback {
     }
 
     /// 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());
@@ -401,34 +411,40 @@ class ClangTidyCheck : public ast_matchers::MatchFinder::MatchCallback {
                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;
     }

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

@@ -27,7 +27,6 @@ StringFindStartswithCheck::StringFindStartswithCheck(StringRef Name,
       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")) {}
@@ -122,8 +121,7 @@ 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);
 }
 

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

@@ -25,13 +25,11 @@ 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);
 }
 

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

@@ -22,7 +22,6 @@ 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(

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

@@ -28,6 +28,31 @@ 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";
@@ -44,25 +69,6 @@ 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(); }
 
@@ -477,15 +483,13 @@ LoopConvertCheck::RangeDescriptor::RangeDescriptor()
 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) {

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

@@ -45,7 +45,6 @@ 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)),
@@ -54,8 +53,7 @@ MakeSmartPtrCheck::MakeSmartPtrCheck(StringRef Name, ClangTidyContext *Context,
       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);

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

@@ -121,13 +121,11 @@ collectParamDecls(const CXXConstructorDecl *Ctor,
 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);
 }
 

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

@@ -75,12 +75,10 @@ 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) {

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

@@ -24,7 +24,6 @@ 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) {
@@ -52,8 +51,7 @@ void ReplaceRandomShuffleCheck::registerPPCallbacks(
 
 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) {