[clang-tidy] Fix a crash in fuchsia-multiple-inheritance

[ilya-biryukov]

Summary

See the test case for a repro.

[hokein]

LGTM.

test/clang-tidy/fuchsia-multiple-inheritance-crash.cpp

1

nit: instead of create a new file, we can put this test case in the existing test/clang-tidy/fuchsia-multiple-inheritance.cpp.

[ilya-biryukov]

• Move the test into an existing file

[lebedev.ri]

(Duplicates D49158)

[ilya-biryukov]

Sorry for sending this in instead of waiting for D49158 to land, I hadn't noticed it earlier

clang-tidy/fuchsia/MultipleInheritanceCheck.cpp

AST_MATCHER(CXXRecordDecl, hasBases) {
   return false;
 }
 } // namespace
 
 // Adds a node (by name) to the interface map, if it was not present in the map
 // previously.
 void MultipleInheritanceCheck::addNodeToInterfaceMap(const CXXRecordDecl *Node,
                                                      bool isInterface) {
+  assert(Node->getIdentifier());
   StringRef Name = Node->getIdentifier()->getName();
   InterfaceMap.insert(std::make_pair(Name, isInterface));
 }
 
 // Returns "true" if the boolean "isInterface" has been set to the
 // interface status of the current Node. Return "false" if the
 // interface status for the current node is not yet known.
 bool MultipleInheritanceCheck::getInterfaceStatus(const CXXRecordDecl *Node,
                                                   bool &isInterface) const {
+  assert(Node->getIdentifier());
   StringRef Name = Node->getIdentifier()->getName();
   llvm::StringMapConstIterator<bool> Pair = InterfaceMap.find(Name);
   if (Pair == InterfaceMap.end())
     return false;
   isInterface = Pair->second;
   return true;
 }
 
 bool MultipleInheritanceCheck::isCurrentClassInterface(
     const CXXRecordDecl *Node) const {
   // Interfaces should have no fields.
   if (!Node->field_empty()) return false;
 
   // Interfaces should have exclusively pure methods.
   return llvm::none_of(Node->methods(), [](const CXXMethodDecl *M) {
     return M->isUserProvided() && !M->isPure() && !M->isStatic();
   });
 }
 
 bool MultipleInheritanceCheck::isInterface(const CXXRecordDecl *Node) {
+  if (!Node->getIdentifier())
+    return false;
+
   // Short circuit the lookup if we have analyzed this record before.
   bool PreviousIsInterfaceResult;
   if (getInterfaceStatus(Node, PreviousIsInterfaceResult))
     return PreviousIsInterfaceResult;
 
   // To be an interface, all base classes must be interfaces as well.
   for (const auto &I : Node->bases()) {
     if (I.isVirtual()) continue;

test/clang-tidy/fuchsia-multiple-inheritance-crash.cpp

+// RUN: clang-tidy -checks='fuchsia-multiple-inheritance' %s --
+template <class T>
+struct X : T {
+  X();
+};
+
+int test() {
+  auto foo = []() {};
+  X<decltype(foo)>();
+}