diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td
index 803203cc50be..779f43ea1f10 100644
--- a/clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -2190,7 +2190,7 @@ def err_attribute_invalid_on_stmt : Error<
   "%0 attribute cannot be applied to a statement">;
 def warn_declspec_attribute_ignored : Warning<
   "attribute %0 is ignored, place it after "
-  "\"%select{class|struct|union|interface|enum}1\" to apply attribute to "
+  "\"%select{class|struct|interface|union|enum}1\" to apply attribute to "
   "type declaration">, InGroup<IgnoredAttributes>;
 def warn_attribute_precede_definition : Warning<
   "attribute declaration must precede definition">,
diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index df8e38ff6681..f750638ea1e1 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -3577,6 +3577,23 @@ void Sema::setTagNameForLinkagePurposes(TagDecl *TagFromDeclSpec,
   TagFromDeclSpec->setTypedefNameForAnonDecl(NewTD);
 }
 
+static unsigned GetDiagnosticTypeSpecifierID(DeclSpec::TST T) {
+  switch (T) {
+  case DeclSpec::TST_class:
+    return 0;
+  case DeclSpec::TST_struct:
+    return 1;
+  case DeclSpec::TST_interface:
+    return 2;
+  case DeclSpec::TST_union:
+    return 3;
+  case DeclSpec::TST_enum:
+    return 4;
+  default:
+    llvm_unreachable("unexpected type specifier");
+  }
+}
+
 /// ParsedFreeStandingDeclSpec - This method is invoked when a declspec with
 /// no declarator (e.g. "struct foo;") is parsed. It also accepts template
 /// parameters to cope with template friend declarations.
@@ -3626,10 +3643,7 @@ Decl *Sema::ParsedFreeStandingDeclSpec(Scope *S, AccessSpecifier AS,
     // and definitions of functions and variables.
     if (Tag)
       Diag(DS.getConstexprSpecLoc(), diag::err_constexpr_tag)
-        << (DS.getTypeSpecType() == DeclSpec::TST_class ? 0 :
-            DS.getTypeSpecType() == DeclSpec::TST_struct ? 1 :
-            DS.getTypeSpecType() == DeclSpec::TST_interface ? 2 :
-            DS.getTypeSpecType() == DeclSpec::TST_union ? 3 : 4);
+          << GetDiagnosticTypeSpecifierID(DS.getTypeSpecType());
     else
       Diag(DS.getConstexprSpecLoc(), diag::err_constexpr_no_declarators);
     // Don't emit warnings after this error.
@@ -3656,11 +3670,7 @@ Decl *Sema::ParsedFreeStandingDeclSpec(Scope *S, AccessSpecifier AS,
     // or an explicit specialization.
     // Per C++ [dcl.enum]p1, an opaque-enum-declaration can't either.
     Diag(SS.getBeginLoc(), diag::err_standalone_class_nested_name_specifier)
-      << (DS.getTypeSpecType() == DeclSpec::TST_class ? 0 :
-          DS.getTypeSpecType() == DeclSpec::TST_struct ? 1 :
-          DS.getTypeSpecType() == DeclSpec::TST_interface ? 2 :
-          DS.getTypeSpecType() == DeclSpec::TST_union ? 3 : 4)
-      << SS.getRange();
+        << GetDiagnosticTypeSpecifierID(DS.getTypeSpecType()) << SS.getRange();
     return nullptr;
   }
 
@@ -3809,14 +3819,9 @@ Decl *Sema::ParsedFreeStandingDeclSpec(Scope *S, AccessSpecifier AS,
         TypeSpecType == DeclSpec::TST_union ||
         TypeSpecType == DeclSpec::TST_enum) {
       for (AttributeList* attrs = DS.getAttributes().getList(); attrs;
-           attrs = attrs->getNext()) {
+           attrs = attrs->getNext())
         Diag(attrs->getLoc(), diag::warn_declspec_attribute_ignored)
-        << attrs->getName()
-        << (TypeSpecType == DeclSpec::TST_class ? 0 :
-            TypeSpecType == DeclSpec::TST_struct ? 1 :
-            TypeSpecType == DeclSpec::TST_union ? 2 :
-            TypeSpecType == DeclSpec::TST_interface ? 3 : 4);
-      }
+            << attrs->getName() << GetDiagnosticTypeSpecifierID(TypeSpecType);
     }
   }