Fix crashing on user-defined conversion.

[congliu]

Summary

Fix the assertion failure for the user-defined conversion method. e.g.: operator bool()

[aaron.ballman]

clang-tidy/misc/VirtualNearMissCheck.cpp

175

Why not isa<CXXConversionDecl>(MD) instead?

[congliu]

• Address the comment and clean up the code.

clang-tidy/misc/VirtualNearMissCheck.cpp

175

Thanks!

[aaron.ballman]

LGTM, thank you!

[alexfh]

Thank you for the fix! Committed as r258801.

clang-tidy/misc/VirtualNearMissCheck.cpp

 /// Generate unique ID for given MethodDecl.
 ///
 /// The Id is used as key for 'PossibleMap'.
 /// Typical Id: "Base::func void (void)"
 static std::string generateMethodId(const CXXMethodDecl *MD) {
   return MD->getQualifiedNameAsString() + " " + MD->getType().getAsString();
 }
 
+/// Finds out if the given method is a user-defined conversion.
+/// A user-defined conversion is of the following form:
+///   operator TypeName()
+static bool isUserDefinedConversion(const CXXMethodDecl *MD) {
+  return StringRef(MD->getNameAsString()).find(StringRef("operator ")) !=
+         StringRef::npos;
+}
+
 bool VirtualNearMissCheck::isPossibleToBeOverridden(
     const CXXMethodDecl *BaseMD) {
   std::string Id = generateMethodId(BaseMD);
   auto Iter = PossibleMap.find(Id);
   if (Iter != PossibleMap.end())
     return Iter->second;
 
   bool IsPossible = !BaseMD->isImplicit() && !isa<CXXConstructorDecl>(BaseMD) &&
                     !isa<CXXDestructorDecl>(BaseMD) && BaseMD->isVirtual() &&
-                    !BaseMD->isOverloadedOperator();
+                    !BaseMD->isOverloadedOperator() &&
+                    !isUserDefinedConversion(BaseMD);
   PossibleMap[Id] = IsPossible;
   return IsPossible;
 }
 
 bool VirtualNearMissCheck::isOverriddenByDerivedClass(
     const CXXMethodDecl *BaseMD, const CXXRecordDecl *DerivedRD) {
   auto Key = std::make_pair(generateMethodId(BaseMD),
                             DerivedRD->getQualifiedNameAsString());
void VirtualNearMissCheck::check(const MatchFinder::MatchResult &Result) {
   assert(DerivedMD);
 
   if (DerivedMD->isStatic())
     return;
 
   if (DerivedMD->isOverloadedOperator())
     return;
 
+  if (isUserDefinedConversion(DerivedMD))
+    return;
+
   const ASTContext *Context = Result.Context;
 
   const auto *DerivedRD = DerivedMD->getParent();
 
   for (const auto &BaseSpec : DerivedRD->bases()) {
     if (const auto *BaseRD = BaseSpec.getType()->getAsCXXRecordDecl()) {
       for (const auto *BaseMD : BaseRD->methods()) {
         if (!isPossibleToBeOverridden(BaseMD))

test/clang-tidy/misc-virtual-near-miss.cpp

public:
   // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: method 'Child::creat' has {{.*}} 'Father::create'
 
   virtual Derived &&generat();
   // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: method 'Child::generat' has {{.*}} 'Father::generate'
 
   int decaz(const char str[]);
   // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: method 'Child::decaz' has {{.*}} 'Mother::decay'
 
+  operator bool();
 private:
   void funk();
   // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: method 'Child::funk' has {{.*}} 'Father::func'
 };