Don't consider records with a NULL identifier as a name for typo correction.

Because in C++, "anonymous" doesn't mean "nameless" for records. In
other words, RecordDecl::isAnonymousStructOrUnion only returns true if
the record lacks a name *and* is not used as the type in an object's
declaration.

llvm-svn: 200868

clang/lib/Sema/SemaLookup.cpp

@@ -4216,7 +4216,7 @@ TypoCorrection Sema::CorrectTypo(const DeclarationNameInfo &TypoName,
       if (CXXRecordDecl *CD = (*TI)->getAsCXXRecordDecl()) {
         CD = CD->getCanonicalDecl();
         if (!CD->isDependentType() && !CD->isAnonymousStructOrUnion() &&
-            !CD->isUnion() &&
+            !CD->isUnion() && CD->getIdentifier() &&
             (CD->isBeingDefined() || CD->isCompleteDefinition()))
           Namespaces.AddNameSpecifier(CD);
       }

clang/test/SemaCXX/typo-correction-pt2.cpp

@@ -199,3 +199,11 @@ template <>
 PR18213::WrapperInfo ::PR18213::Wrappable<int>::kWrapperInfo = { 0 };  // expected-error {{no member named 'PR18213' in 'PR18213::WrapperInfo'; did you mean simply 'PR18213'?}} \
                                                                        // expected-error {{C++ requires a type specifier for all declarations}}
 }
+
+namespace PR18651 {
+struct {
+  int x;
+} a, b;
+
+int y = x;  // expected-error-re {{use of undeclared identifier 'x'{{$}}}}
+}