diff --git a/llvm/lib/Option/OptTable.cpp b/llvm/lib/Option/OptTable.cpp
index d4486c6..7910bea 100644
--- a/llvm/lib/Option/OptTable.cpp
+++ b/llvm/lib/Option/OptTable.cpp
@@ -196,7 +196,7 @@
 
 // Returns true if one of the Prefixes + In.Names matches Option
 static bool optionMatches(const OptTable::Info &In, StringRef Option) {
-  if (In.Prefixes)
+  if (In.Values && In.Prefixes)
     for (size_t I = 0; In.Prefixes[I]; I++)
       if (Option == std::string(In.Prefixes[I]) + In.Name)
         return true;
@@ -209,9 +209,8 @@
 std::vector<std::string>
 OptTable::suggestValueCompletions(StringRef Option, StringRef Arg) const {
   // Search all options and return possible values.
-  for (size_t I = FirstSearchableIndex, E = OptionInfos.size(); I < E; I++) {
-    const Info &In = OptionInfos[I];
-    if (!In.Values || !optionMatches(In, Option))
+  for (const Info &In : OptionInfos.slice(FirstSearchableIndex)) {
+    if (!optionMatches(In, Option))
       continue;
 
     SmallVector<StringRef, 8> Candidates;
@@ -229,8 +228,7 @@
 std::vector<std::string>
 OptTable::findByPrefix(StringRef Cur, unsigned short DisableFlags) const {
   std::vector<std::string> Ret;
-  for (size_t I = FirstSearchableIndex, E = OptionInfos.size(); I < E; I++) {
-    const Info &In = OptionInfos[I];
+  for (const Info &In : OptionInfos.slice(FirstSearchableIndex)) {
     if (!In.Prefixes || (!In.HelpText && !In.GroupID))
       continue;
     if (In.Flags & DisableFlags)
@@ -247,17 +245,6 @@
   return Ret;
 }
 
-bool OptTable::addValues(const char *Option, const char *Values) {
-  for (size_t I = FirstSearchableIndex, E = OptionInfos.size(); I < E; I++) {
-    Info &In = OptionInfos[I];
-    if (optionMatches(In, Option)) {
-      In.Values = Values;
-      return true;
-    }
-  }
-  return false;
-}
-
 Arg *OptTable::ParseOneArg(const ArgList &Args, unsigned &Index,
                            unsigned FlagsToInclude,
                            unsigned FlagsToExclude) const {
@@ -269,8 +256,8 @@
   if (isInput(PrefixesUnion, Str))
     return new Arg(getOption(TheInputOptionID), Str, Index++, Str);
 
-  const Info *Start = OptionInfos.data() + FirstSearchableIndex;
-  const Info *End = OptionInfos.data() + OptionInfos.size();
+  const Info *Start = OptionInfos.begin() + FirstSearchableIndex;
+  const Info *End = OptionInfos.end();
   StringRef Name = StringRef(Str).ltrim(PrefixChars);
 
   // Search for the first next option which could be a prefix.