Add SpellingNotCalculated to Attribute Enums to suppress UBSan warnings

UBSan downstreams noticed that the assignment of SpellingNotCalculated
to the spellings caused warnings.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@372124 91177308-0d34-0410-b5e6-96231b3b80d8

lib/AST/MicrosoftMangle.cpp

@@ -615,6 +615,8 @@ void MicrosoftCXXNameMangler::mangleMemberDataPointer(const CXXRecordDecl *RD,
   case MSInheritanceAttr::Keyword_multiple_inheritance:    Code = '0'; break;
   case MSInheritanceAttr::Keyword_virtual_inheritance:     Code = 'F'; break;
   case MSInheritanceAttr::Keyword_unspecified_inheritance: Code = 'G'; break;
+  case MSInheritanceAttr::SpellingNotCalculated:
+    llvm_unreachable("not reachable");
   }
 
   Out << '$' << Code;
@@ -646,6 +648,8 @@ MicrosoftCXXNameMangler::mangleMemberFunctionPointer(const CXXRecordDecl *RD,
   case MSInheritanceAttr::Keyword_multiple_inheritance:    Code = 'H'; break;
   case MSInheritanceAttr::Keyword_virtual_inheritance:     Code = 'I'; break;
   case MSInheritanceAttr::Keyword_unspecified_inheritance: Code = 'J'; break;
+  case MSInheritanceAttr::SpellingNotCalculated:
+    llvm_unreachable("not reachable");
   }
 
   // If non-virtual, mangle the name.  If virtual, mangle as a virtual memptr

lib/CodeGen/CGDebugInfo.cpp

@@ -2711,6 +2711,8 @@ llvm::DIType *CGDebugInfo::CreateType(const MemberPointerType *Ty,
         break;
       case MSInheritanceAttr::Keyword_unspecified_inheritance:
         break;
+      case MSInheritanceAttr::SpellingNotCalculated:
+        llvm_unreachable("Spelling not yet calculated");
       }
     }
   }

lib/Sema/SemaType.cpp

@@ -1633,6 +1633,8 @@ static QualType ConvertDeclSpecToType(TypeProcessingState &state) {
     case OpenCLAccessAttr::Keyword_read_only:                                  \
       Result = Context.Id##ROTy;                                               \
       break;                                                                   \
+    case OpenCLAccessAttr::SpellingNotCalculated:                              \
+      llvm_unreachable("Spelling not yet calculated");                         \
     }                                                                          \
     break;
 #include "clang/Basic/OpenCLImageTypes.def"

utils/TableGen/ClangAttrEmitter.cpp

@@ -1596,6 +1596,13 @@ CreateSemanticSpellings(const std::vector<FlattenedSpelling> &Spellings,
   std::string Ret("  enum Spelling {\n");
   std::set<std::string> Uniques;
   unsigned Idx = 0;
+
+  // If we have a need to have this many spellings we likely need to add an
+  // extra bit to the SpellingIndex in AttributeCommonInfo, then increase the
+  // value of SpellingNotCalculated there and here.
+  assert(Spellings.size() < 15 &&
+         "Too many spellings, would step on SpellingNotCalculated in "
+         "AttributeCommonInfo");
   for (auto I = Spellings.begin(), E = Spellings.end(); I != E; ++I, ++Idx) {
     const FlattenedSpelling &S = *I;
     const std::string &Variety = S.variety();
@@ -1629,6 +1636,7 @@ CreateSemanticSpellings(const std::vector<FlattenedSpelling> &Spellings,
     // enumerator.
     Ret += "    " + EnumName + " = " + llvm::utostr(Idx);
   }
+  Ret += ",\n  SpellingNotCalculated = 15\n";
   Ret += "\n  };\n\n";
   return Ret;
 }