[llvm] Use std::nullopt instead of None (NFC)

This patch mechanically replaces None with std::nullopt where the
compiler would warn if None were deprecated.  The intent is to reduce
the amount of manual work required in migrating from Optional to
std::optional.

This is part of an effort to migrate from llvm::Optional to
std::optional:

https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716

1 files changed, 15 insertions, 14 deletions

diff --git a/llvm/lib/Support/YAMLParser.cpp b/llvm/lib/Support/YAMLParser.cpp
index e9619f5..5046074 100644
--- a/llvm/lib/Support/YAMLParser.cpp
+++ b/llvm/lib/Support/YAMLParser.cpp
@@ -259,8 +259,9 @@ public:
   Token getNext();
 
   void printError(SMLoc Loc, SourceMgr::DiagKind Kind, const Twine &Message,
-                  ArrayRef<SMRange> Ranges = None) {
-    SM.PrintMessage(Loc, Kind, Message, Ranges, /* FixIts= */ None, ShowColors);
+                  ArrayRef<SMRange> Ranges = std::nullopt) {
+    SM.PrintMessage(Loc, Kind, Message, Ranges, /* FixIts= */ std::nullopt,
+                    ShowColors);
   }
 
   void setError(const Twine &Message, StringRef::iterator Position) {
@@ -771,7 +772,7 @@ llvm::Optional<bool> yaml::parseBool(StringRef S) {
     case 'N':
       return false;
     default:
-      return None;
+      return std::nullopt;
     }
   case 2:
     switch (S.front()) {
@@ -782,7 +783,7 @@ llvm::Optional<bool> yaml::parseBool(StringRef S) {
     case 'o':
       if (S[1] == 'n') //[Oo]n
         return true;
-      return None;
+      return std::nullopt;
     case 'N':
       if (S[1] == 'O') // NO
         return false;
@@ -790,9 +791,9 @@ llvm::Optional<bool> yaml::parseBool(StringRef S) {
     case 'n':
       if (S[1] == 'o') //[Nn]o
         return false;
-      return None;
+      return std::nullopt;
     default:
-      return None;
+      return std::nullopt;
     }
   case 3:
     switch (S.front()) {
@@ -803,7 +804,7 @@ llvm::Optional<bool> yaml::parseBool(StringRef S) {
     case 'o':
       if (S.drop_front() == "ff") //[Oo]ff
         return false;
-      return None;
+      return std::nullopt;
     case 'Y':
       if (S.drop_front() == "ES") // YES
         return true;
@@ -811,9 +812,9 @@ llvm::Optional<bool> yaml::parseBool(StringRef S) {
     case 'y':
       if (S.drop_front() == "es") //[Yy]es
         return true;
-      return None;
+      return std::nullopt;
     default:
-      return None;
+      return std::nullopt;
     }
   case 4:
     switch (S.front()) {
@@ -824,9 +825,9 @@ llvm::Optional<bool> yaml::parseBool(StringRef S) {
     case 't':
       if (S.drop_front() == "rue") //[Tt]rue
         return true;
-      return None;
+      return std::nullopt;
     default:
-      return None;
+      return std::nullopt;
     }
   case 5:
     switch (S.front()) {
@@ -837,12 +838,12 @@ llvm::Optional<bool> yaml::parseBool(StringRef S) {
     case 'f':
       if (S.drop_front() == "alse") //[Ff]alse
         return false;
-      return None;
+      return std::nullopt;
     default:
-      return None;
+      return std::nullopt;
     }
   default:
-    return None;
+    return std::nullopt;
   }
 }