[clang-tidy] Simplify suspicious enum usage check

clang-tools-extra/clang-tidy/bugprone/SuspiciousEnumUsageCheck.h

 /// For the user-facing documentation see:
 /// http://clang.llvm.org/extra/clang-tidy/checks/bugprone-suspicious-enum-usage.html
 class SuspiciousEnumUsageCheck : public ClangTidyCheck {
 public:
   SuspiciousEnumUsageCheck(StringRef Name, ClangTidyContext *Context);
   void registerMatchers(ast_matchers::MatchFinder *Finder) override;
   void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
   void storeOptions(ClangTidyOptions::OptionMap &Opts) override;
+  llvm::Optional<TraversalKind> getCheckTraversalKind() const override {
+    return TK_IgnoreUnlessSpelledInSource;
+  }
 
 private:
   void checkSuspiciousBitmaskUsage(const Expr*, const EnumDecl*);
   const bool StrictMode;
 };
 
 } // namespace bugprone
 } // namespace tidy
 } // namespace clang
 
 #endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_BUGPRONE_SUSPICIOUSENUMUSAGECHECK_H

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

: ClangTidyCheck(Name, Context),
       StrictMode(Options.getLocalOrGlobal("StrictMode", false)) {}
 
 void SuspiciousEnumUsageCheck::storeOptions(ClangTidyOptions::OptionMap &Opts) {
   Options.store(Opts, "StrictMode", StrictMode);
 }
 
 void SuspiciousEnumUsageCheck::registerMatchers(MatchFinder *Finder) {
   const auto EnumExpr = [](StringRef RefName, StringRef DeclName) {
-    return expr(ignoringImpCasts(expr().bind(RefName)),
-                ignoringImpCasts(hasType(enumDecl().bind(DeclName))));
+    return expr(hasType(enumDecl().bind(DeclName))).bind(RefName);
   };
 
   Finder->addMatcher(
-      binaryOperator(hasOperatorName("|"), hasLHS(EnumExpr("", "enumDecl")),
-                     hasRHS(expr(EnumExpr("", "otherEnumDecl"),
-                                 ignoringImpCasts(hasType(enumDecl(
-                                     unless(equalsBoundNode("enumDecl"))))))))
+      binaryOperator(
+          hasOperatorName("|"), hasLHS(hasType(enumDecl().bind("enumDecl"))),
+          hasRHS(hasType(enumDecl(unless(equalsBoundNode("enumDecl")))
+                             .bind("otherEnumDecl"))))
           .bind("diffEnumOp"),
       this);
 
   Finder->addMatcher(
       binaryOperator(hasAnyOperatorName("+", "|"),
                      hasLHS(EnumExpr("lhsExpr", "enumDecl")),
-                     hasRHS(expr(EnumExpr("rhsExpr", ""),
-                                 ignoringImpCasts(hasType(
-                                     enumDecl(equalsBoundNode("enumDecl"))))))),
+                     hasRHS(expr(hasType(enumDecl(equalsBoundNode("enumDecl"))))
+                                .bind("rhsExpr"))),
       this);
 
   Finder->addMatcher(
       binaryOperator(
           hasAnyOperatorName("+", "|"),
-          hasOperands(expr(hasType(isInteger()), unless(EnumExpr("", ""))),
+          hasOperands(expr(hasType(isInteger()), unless(hasType(enumDecl()))),
                       EnumExpr("enumExpr", "enumDecl"))),
       this);
 
   Finder->addMatcher(binaryOperator(hasAnyOperatorName("|=", "+="),
                                     hasRHS(EnumExpr("enumExpr", "enumDecl"))),
                      this);
 }