OptTable.cpp

static bool optionMatches(const OptTable::Info &In, std::string C) {
  if (!In.ArgValues || !In.Prefixes)
    return true;
  
  for (size_t I = 0; In.Prefixes[I]; I++)
    if (C == std::string(In.Prefixes[I]) + In.Name)
      return false;
  return true;
} 
    
// This function is for flag value completion.
// Eg. When l,=,-stdlib was passed to this function, it will return appropiriate
// values for stdlib, which starts with l. 
std::vector<std::string> OptTable::suggestValueCompletions(
    const SmallVectorImpl<StringRef> &Command) const {
  if (Command.size() <= 1)
    return {};

  std::vector<std::string> Result;
  int eq = 0;

  std::string C;
  if (Command[0] == "=") {
    C = std::string(Command[1]) + "=";
    eq = 1;
  } else {
    // values are parsed like l,=,-stdlib by bash. We have to concat = to
    // -stdlib because they are separated.
    C = (Command[1] == "=") ? std::string(Command[2]) + "="
                                        : std::string(Command[1]);
  } 
    
  for (const Info &In : OptionInfos.slice(FirstSearchableIndex)) {
    if (optionMatches(In, C))
      continue;
    
    SmallVector<StringRef, 8> Values;
    StringRef(In.ArgValues).split(Values, ",", -1, false);
    for (StringRef Val : Values) {
      if (eq)
        Result.push_back(Val);
      else if (Val.startswith(Command[0]))
        Result.push_back(Val);
    }
  } 
  return Result;
}