[clang-tidy][NFC] Give structs, classes, and enums internal linkage where applicable (#172947)

Fixing the instances found by `misc-use-internal-linkage` in #172797.

Author: localspook

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

@@ -66,6 +66,8 @@ template <> struct MappingTraits<ClangTidyOptions::StringPair> {
   }
 };
 
+namespace {
+
 struct NOptionMap {
   NOptionMap(IO &) {}
   NOptionMap(IO &, const ClangTidyOptions::OptionMap &OptionMap) {
@@ -83,6 +85,8 @@ struct NOptionMap {
   std::vector<ClangTidyOptions::StringPair> Options;
 };
 
+} // namespace
+
 template <>
 void yamlize(IO &IO, ClangTidyOptions::OptionMap &Val, bool,
              EmptyContext &Ctx) {
@@ -176,11 +180,15 @@ template <> struct MappingTraits<ClangTidyOptions::CustomCheckValue> {
   }
 };
 
+namespace {
+
 struct GlobListVariant {
   std::optional<std::string> AsString;
   std::optional<std::vector<std::string>> AsVector;
 };
 
+} // namespace
+
 template <>
 void yamlize(IO &IO, GlobListVariant &Val, bool, EmptyContext &Ctx) {
   if (!IO.outputting()) {

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

@@ -35,9 +35,13 @@ namespace clang::tidy {
 // NoLintType
 //===----------------------------------------------------------------------===//
 
+namespace {
+
 // The type - one of NOLINT[NEXTLINE/BEGIN/END].
 enum class NoLintType { NoLint, NoLintNextLine, NoLintBegin, NoLintEnd };
 
+} // namespace
+
 // Convert a string like "NOLINTNEXTLINE" to its enum `Type::NoLintNextLine`.
 // Return `std::nullopt` if the string is unrecognized.
 static std::optional<NoLintType> strToNoLintType(StringRef Str) {

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

@@ -32,6 +32,7 @@
 
 namespace clang::tidy {
 namespace abseil {
+namespace {
 
 class AbseilModule : public ClangTidyModule {
 public:
@@ -75,6 +76,8 @@ class AbseilModule : public ClangTidyModule {
   }
 };
 
+} // namespace
+
 // Register the AbseilModule using this statically initialized variable.
 static ClangTidyModuleRegistry::Add<AbseilModule> X("abseil-module",
                                                     "Add Abseil checks.");

clang-tools-extra/clang-tidy/altera/AlteraTidyModule.cpp

@@ -19,6 +19,7 @@ using namespace clang::ast_matchers;
 
 namespace clang::tidy {
 namespace altera {
+namespace {
 
 class AlteraModule : public ClangTidyModule {
 public:
@@ -35,6 +36,7 @@ class AlteraModule : public ClangTidyModule {
   }
 };
 
+} // namespace
 } // namespace altera
 
 // Register the AlteraTidyModule using this statically initialized variable.

clang-tools-extra/clang-tidy/android/AndroidTidyModule.cpp

@@ -29,6 +29,7 @@ using namespace clang::ast_matchers;
 
 namespace clang::tidy {
 namespace android {
+namespace {
 
 /// This module is for Android specific checks.
 class AndroidModule : public ClangTidyModule {
@@ -59,6 +60,8 @@ class AndroidModule : public ClangTidyModule {
   }
 };
 
+} // namespace
+
 // Register the AndroidTidyModule using this statically initialized variable.
 static ClangTidyModuleRegistry::Add<AndroidModule>
     X("android-module", "Adds Android platform checks.");

clang-tools-extra/clang-tidy/boost/BoostTidyModule.cpp

@@ -15,6 +15,7 @@ using namespace clang::ast_matchers;
 
 namespace clang::tidy {
 namespace boost {
+namespace {
 
 class BoostModule : public ClangTidyModule {
 public:
@@ -24,6 +25,8 @@ class BoostModule : public ClangTidyModule {
   }
 };
 
+} // namespace
+
 // Register the BoostModule using this statically initialized variable.
 static ClangTidyModuleRegistry::Add<BoostModule> X("boost-module",
                                                    "Add boost checks.");

clang-tools-extra/clang-tidy/bugprone/BugproneTidyModule.cpp

@@ -115,6 +115,7 @@
 
 namespace clang::tidy {
 namespace bugprone {
+namespace {
 
 class BugproneModule : public ClangTidyModule {
 public:
@@ -319,6 +320,7 @@ class BugproneModule : public ClangTidyModule {
   }
 };
 
+} // namespace
 } // namespace bugprone
 
 // Register the BugproneTidyModule using this statically initialized variable.

clang-tools-extra/clang-tidy/bugprone/EasilySwappableParametersCheck.cpp

@@ -106,6 +106,8 @@ static bool prefixSuffixCoverUnderThreshold(std::size_t Threshold,
 
 namespace model {
 
+namespace {
+
 /// The language features involved in allowing the mix between two parameters.
 enum class MixFlags : unsigned char {
   Invalid = 0, ///< Sentinel bit pattern. DO NOT USE!
@@ -129,6 +131,9 @@ enum class MixFlags : unsigned char {
 
   LLVM_MARK_AS_BITMASK_ENUM(/* LargestValue =*/ImplicitConversion)
 };
+
+} // namespace
+
 LLVM_ENABLE_BITMASK_ENUMS_IN_NAMESPACE();
 
 /// Returns whether the SearchedFlag is turned on in the Data.
@@ -179,6 +184,8 @@ static inline std::string formatMixFlags(MixFlags F) {
 
 #endif // NDEBUG
 
+namespace {
+
 /// The results of the steps of an Implicit Conversion Sequence is saved in
 /// an instance of this record.
 ///
@@ -565,6 +572,8 @@ enum class ImplicitConversionModellingMode : unsigned char {
   OneWaySingleStandardOnly
 };
 
+} // namespace
+
 static MixData
 isLRefEquallyBindingToType(const TheCheck &Check,
                            const LValueReferenceType *LRef, QualType Ty,
@@ -1594,6 +1603,8 @@ static bool lazyMapOfSetsIntersectionExists(const MapTy &Map, const ElemTy &E1,
   });
 }
 
+namespace {
+
 /// Implements the heuristic that marks two parameters related if there is
 /// a usage for both in the same strict expression subtree. A strict
 /// expression subtree is a tree which only includes Expr nodes, i.e. no
@@ -1755,6 +1766,8 @@ class Returned {
   }
 };
 
+} // namespace
+
 } // namespace relatedness_heuristic
 
 /// Helper class that is used to detect if two parameters of the same function
@@ -1950,7 +1963,7 @@ static inline bool needsToPrintTypeInDiagnostic(const model::Mix &M) {
 /// Returns whether a particular Mix between the two parameters should have
 /// implicit conversions elaborated.
 static inline bool needsToElaborateImplicitConversion(const model::Mix &M) {
-  return hasFlag(M.flags(), model::MixFlags::ImplicitConversion);
+  return model::hasFlag(M.flags(), model::MixFlags::ImplicitConversion);
 }
 
 namespace {

clang-tools-extra/clang-tidy/bugprone/NotNullTerminatedResultCheck.cpp

@@ -32,11 +32,11 @@ constexpr StringRef LengthExprName = "LengthExpr";
 constexpr StringRef WrongLengthExprName = "WrongLength";
 constexpr StringRef UnknownLengthName = "UnknownLength";
 
+namespace {
 enum class LengthHandleKind { Increase, Decrease };
+} // namespace
 
-namespace {
 static Preprocessor *PP;
-} // namespace
 
 // Returns the expression of destination's capacity which is part of a
 // 'VariableArrayType', 'ConstantArrayTypeLoc' or an argument of a 'malloc()'

clang-tools-extra/clang-tidy/bugprone/StringIntegerAssignmentCheck.cpp

@@ -40,6 +40,8 @@ void StringIntegerAssignmentCheck::registerMatchers(MatchFinder *Finder) {
       this);
 }
 
+namespace {
+
 class CharExpressionDetector {
 public:
   CharExpressionDetector(QualType CharType, const ASTContext &Ctx)
@@ -124,6 +126,8 @@ class CharExpressionDetector {
   const ASTContext &Ctx;
 };
 
+} // namespace
+
 void StringIntegerAssignmentCheck::check(
     const MatchFinder::MatchResult &Result) {
   const auto *Argument = Result.Nodes.getNodeAs<Expr>("expr");