[TableGen] Fix MSVC warning that occurs in TableGen generated function

This should fix the Windows buildbot failure that happened after r300539.

llvm-svn: 300540

diff --git a/clang/utils/TableGen/ClangAttrEmitter.cpp b/clang/utils/TableGen/ClangAttrEmitter.cpp
index 6dc3911..7aa8bdc 100644 (file)
--- a/clang/utils/TableGen/ClangAttrEmitter.cpp
+++ b/clang/utils/TableGen/ClangAttrEmitter.cpp
@@ -3167,7 +3167,9 @@ emitAttributeMatchRules(PragmaClangAttributeSupport &PragmaAttributeSupport,
     }
     OS << ";\n";
   }
-  OS << "  }\n}\n\n";
+  OS << "  }\n";
+  OS << "  llvm_unreachable(\"Invalid match rule\");\n";
+  OS << "}\n\n";
 }
 
 static void GenerateDefaultLangOptRequirements(raw_ostream &OS) {