Undef the macros after their use

[Eugene.Zelenko]

I don't see anything wrong with this change, but will be good idea to wait for code owner approval.

include/llvm/MC/MCLinkerOptimizationHint.h

80–81

You could return {}.

[hiraditya]

return {}.

[hiraditya]

ping

[hiraditya]

I'll merge this patch as if there are no further feedbacks.

[hiraditya]

rebase

include/llvm/MC/MCLinkerOptimizationHint.h

return StringSwitch<int>(Name)
     MCLOHCaseNameToId(AdrpLdr)
     MCLOHCaseNameToId(AdrpAddLdr)
     MCLOHCaseNameToId(AdrpLdrGotLdr)
     MCLOHCaseNameToId(AdrpAddStr)
     MCLOHCaseNameToId(AdrpLdrGotStr)
     MCLOHCaseNameToId(AdrpAdd)
     MCLOHCaseNameToId(AdrpLdrGot)
     .Default(-1);
+#undef MCLOHCaseNameToId
 }
 
 static inline StringRef MCLOHIdToName(MCLOHType Kind) {
 #define MCLOHCaseIdToName(Name)      case MCLOH_ ## Name: return StringRef(#Name);
   switch (Kind) {
     MCLOHCaseIdToName(AdrpAdrp);
     MCLOHCaseIdToName(AdrpLdr);
     MCLOHCaseIdToName(AdrpAddLdr);
     MCLOHCaseIdToName(AdrpLdrGotLdr);
     MCLOHCaseIdToName(AdrpAddStr);
     MCLOHCaseIdToName(AdrpLdrGotStr);
     MCLOHCaseIdToName(AdrpAdd);
     MCLOHCaseIdToName(AdrpLdrGot);
   }
-  return StringRef();
+  return {};
+#undef MCLOHCaseIdToName
 }
 
 static inline int MCLOHIdToNbArgs(MCLOHType Kind) {
   switch (Kind) {
     // LOH with two arguments
   case MCLOH_AdrpAdrp:
   case MCLOH_AdrpLdr:
   case MCLOH_AdrpAdd: