2 files changed, 21 insertions, 15 deletions
diff --git a/lib/Sema/SemaDeclCXX.cpp b/lib/Sema/SemaDeclCXX.cpp
index cc0aadeec2..1da1884752 100644
--- a/lib/Sema/SemaDeclCXX.cpp
+++ b/lib/Sema/SemaDeclCXX.cpp
@@ -1311,29 +1311,25 @@ void Sema::ActOnBaseSpecifiers(Decl *ClassDecl, CXXBaseSpecifier **Bases,
                        (CXXBaseSpecifier**)(Bases), NumBases);
 }
 
-static CXXRecordDecl *GetClassForType(QualType T) {
-  if (const RecordType *RT = T->getAs<RecordType>())
-    return cast<CXXRecordDecl>(RT->getDecl());
-  else if (const InjectedClassNameType *ICT = T->getAs<InjectedClassNameType>())
-    return ICT->getDecl();
-  else
-    return 0;
-}
-
 /// \brief Determine whether the type \p Derived is a C++ class that is
 /// derived from the type \p Base.
 bool Sema::IsDerivedFrom(QualType Derived, QualType Base) {
   if (!getLangOpts().CPlusPlus)
     return false;
   
-  CXXRecordDecl *DerivedRD = GetClassForType(Derived);
+  CXXRecordDecl *DerivedRD = Derived->getAsCXXRecordDecl();
   if (!DerivedRD)
     return false;
   
-  CXXRecordDecl *BaseRD = GetClassForType(Base);
+  CXXRecordDecl *BaseRD = Base->getAsCXXRecordDecl();
   if (!BaseRD)
     return false;
-  
+
+  // If either the base or the derived type is invalid, don't try to
+  // check whether one is derived from the other.
+  if (BaseRD->isInvalidDecl() || DerivedRD->isInvalidDecl())
+    return false;
+
   // FIXME: instantiate DerivedRD if necessary.  We need a PoI for this.
   return DerivedRD->hasDefinition() && DerivedRD->isDerivedFrom(BaseRD);
 }
@@ -1344,11 +1340,11 @@ bool Sema::IsDerivedFrom(QualType Derived, QualType Base, CXXBasePaths &Paths) {
   if (!getLangOpts().CPlusPlus)
     return false;
   
-  CXXRecordDecl *DerivedRD = GetClassForType(Derived);
+  CXXRecordDecl *DerivedRD = Derived->getAsCXXRecordDecl();
   if (!DerivedRD)
     return false;
   
-  CXXRecordDecl *BaseRD = GetClassForType(Base);
+  CXXRecordDecl *BaseRD = Base->getAsCXXRecordDecl();
   if (!BaseRD)
     return false;
   
diff --git a/lib/Sema/SemaOverload.cpp b/lib/Sema/SemaOverload.cpp
index 3ed0465794..5d931cfcaf 100644
--- a/lib/Sema/SemaOverload.cpp
+++ b/lib/Sema/SemaOverload.cpp
@@ -3937,6 +3937,15 @@ CompareDerivedToBaseConversions(Sema &S,
   return ImplicitConversionSequence::Indistinguishable;
 }
 
+/// \brief Determine whether the given type is valid, e.g., it is not an invalid
+/// C++ class.
+static bool isTypeValid(QualType T) {
+  if (CXXRecordDecl *Record = T->getAsCXXRecordDecl())
+    return !Record->isInvalidDecl();
+
+  return true;
+}
+
 /// CompareReferenceRelationship - Compare the two types T1 and T2 to
 /// determine whether they are reference-related,
 /// reference-compatible, reference-compatible with added
@@ -3970,7 +3979,8 @@ Sema::CompareReferenceRelationship(SourceLocation Loc,
   if (UnqualT1 == UnqualT2) {
     // Nothing to do.
   } else if (!RequireCompleteType(Loc, OrigT2, 0) &&
-           IsDerivedFrom(UnqualT2, UnqualT1))
+             isTypeValid(UnqualT1) && isTypeValid(UnqualT2) &&
+             IsDerivedFrom(UnqualT2, UnqualT1))
     DerivedToBase = true;
   else if (UnqualT1->isObjCObjectOrInterfaceType() &&
            UnqualT2->isObjCObjectOrInterfaceType() &&