[NFC] Replace strlen with StringRef::size

[1lyasm]

Summary

Replace multiple strlen calls with a StringRef constructor and a StringRef::size call.
Rename ArgSize to SpellingSize, and add ArgStringSize.

[1lyasm]

Renamed ArgSize to SpellingSize, because both ArgSize and ArgStringSize would be confusing

[1lyasm]

I do not have commit access, can you commit this for me?
(Ilyas Mustafazade <[e-mail]>)

[vitalybuka]

llvm/lib/Option/Option.cpp

208

@hans do you know what this TODO is about, https://reviews.llvm.org/D1387
If this is about performance, we still have strlen in StringRef

[vitalybuka]

I've spitted the patch in 2

[vitalybuka]

submitted

[1lyasm]

Thank you.

[hans]

llvm/lib/Option/Option.cpp

208

I just copied it from the other flag classes. The FIXMEs were added in https://github.com/llvm/llvm-project/commit/458b6982d471992337639382cdac1bb30311b4c0

I'm guessing the author figured the sizes should already be known (I think the ArgList is storing StringRefs maybe?) and the strlen shouldn't really be needed.

I think that's a minor detail, but one day it would be nice to modernize the whole options framework and use less char pointers.

llvm/lib/Option/Option.cpp

if (Group.isValid())
     return Group.matches(Opt);
   return false;
 }
 
 std::unique_ptr<Arg> Option::acceptInternal(const ArgList &Args,
                                             StringRef Spelling,
                                             unsigned &Index) const {
   const size_t SpellingSize = Spelling.size();
+  const size_t ArgStringSize = StringRef(Args.getArgString(Index)).size();
   switch (getKind()) {
   case FlagClass: {
-    if (SpellingSize != strlen(Args.getArgString(Index)))
+    if (SpellingSize != ArgStringSize)
       return nullptr;
     return std::make_unique<Arg>(*this, Spelling, Index++);
   }
   case JoinedClass: {
     const char *Value = Args.getArgString(Index) + SpellingSize;
     return std::make_unique<Arg>(*this, Spelling, Index++, Value);
   }
   case CommaJoinedClass: {
for (;; ++Str) {
       }
     }
     A->setOwnsValues(true);
 
     return A;
   }
   case SeparateClass:
     // Matches iff this is an exact match.
-    // FIXME: Avoid strlen.
-    if (SpellingSize != strlen(Args.getArgString(Index)))
+    if (SpellingSize != ArgStringSize)
       return nullptr;
 
     Index += 2;
     if (Index > Args.getNumInputArgStrings() ||
         Args.getArgString(Index - 1) == nullptr)
       return nullptr;
 
     return std::make_unique<Arg>(*this, Spelling, Index - 2,
                                  Args.getArgString(Index - 1));
   case MultiArgClass: {
     // Matches iff this is an exact match.
-    // FIXME: Avoid strlen.
-    if (SpellingSize != strlen(Args.getArgString(Index)))
+    if (SpellingSize != ArgStringSize)
       return nullptr;
 
     Index += 1 + getNumArgs();
     if (Index > Args.getNumInputArgStrings())
       return nullptr;
 
     auto A = std::make_unique<Arg>(*this, Spelling, Index - 1 - getNumArgs(),
                                    Args.getArgString(Index - getNumArgs()));
     for (unsigned i = 1; i != getNumArgs(); ++i)
       A->getValues().push_back(Args.getArgString(Index - getNumArgs() + i));
     return A;
   }
   case JoinedOrSeparateClass: {
     // If this is not an exact match, it is a joined arg.
-    // FIXME: Avoid strlen.
-    if (SpellingSize != strlen(Args.getArgString(Index))) {
+    if (SpellingSize != ArgStringSize) {
       const char *Value = Args.getArgString(Index) + SpellingSize;
       return std::make_unique<Arg>(*this, Spelling, Index++, Value);
     }
 
     // Otherwise it must be separate.
     Index += 2;
     if (Index > Args.getNumInputArgStrings() ||
         Args.getArgString(Index - 1) == nullptr)
if (Index > Args.getNumInputArgStrings() ||
         Args.getArgString(Index - 1) == nullptr)
       return nullptr;
 
     return std::make_unique<Arg>(*this, Spelling, Index - 2,
                                  Args.getArgString(Index - 2) + SpellingSize,
                                  Args.getArgString(Index - 1));
   case RemainingArgsClass: {
     // Matches iff this is an exact match.
-    // FIXME: Avoid strlen.
-    if (SpellingSize != strlen(Args.getArgString(Index)))
+    if (SpellingSize != ArgStringSize)
       return nullptr;
     auto A = std::make_unique<Arg>(*this, Spelling, Index++);
     while (Index < Args.getNumInputArgStrings() &&
            Args.getArgString(Index) != nullptr)
       A->getValues().push_back(Args.getArgString(Index++));
     return A;
   }
   case RemainingArgsJoinedClass: {
     auto A = std::make_unique<Arg>(*this, Spelling, Index);
-    if (SpellingSize != strlen(Args.getArgString(Index))) {
+    if (SpellingSize != ArgStringSize) {
       // An inexact match means there is a joined arg.
       A->getValues().push_back(Args.getArgString(Index) + SpellingSize);
     }
     Index++;
     while (Index < Args.getNumInputArgStrings() &&
            Args.getArgString(Index) != nullptr)
       A->getValues().push_back(Args.getArgString(Index++));
     return A;