static bool ParsePrecision(FormatStringHandler &H, PrintfSpecifier &FS,
                           const char *Start, const char *&Beg, const char *E,
                           unsigned *argIndex) {
  if (argIndex) {
    FS.setPrecision(ParseNonPositionAmount(Beg, E, *argIndex));
  } else {
    const OptionalAmount Amt = ParsePositionAmount(H, Start, Beg, E,
                                           analyze_format_string::PrecisionPos);
    if (Amt.isInvalid())
      return true;
    FS.setPrecision(Amt);
  }
  return false;
}
static bool ParseObjCFlags(FormatStringHandler &H, PrintfSpecifier &FS,
                           const char *FlagBeg, const char *E, bool Warn) {
   StringRef Flag(FlagBeg, E - FlagBeg);
   // Currently there is only one flag.
   if (Flag == "tt") {
     FS.setHasObjCTechnicalTerm(FlagBeg);
     return false;
   }
   // Handle either the case of no flag or an invalid flag.
   if (Warn) {
     if (Flag == "")
       H.HandleEmptyObjCModifierFlag(FlagBeg, E  - FlagBeg);
     else
       H.HandleInvalidObjCModifierFlag(FlagBeg, E  - FlagBeg);
   }
   return true;
}
static PrintfSpecifierResult ParsePrintfSpecifier(FormatStringHandler &H,
                                                  const char *&Beg,
                                                  const char *E,
                                                  unsigned &argIndex,
                                                  const LangOptions &LO,
                                                  const TargetInfo &Target,
                                                  bool Warn,
                                                  bool isFreeBSDKPrintf) {

  using namespace clang::analyze_format_string;
  using namespace clang::analyze_printf;

  const char *I = Beg;
  const char *Start = nullptr;
  UpdateOnReturn <const char*> UpdateBeg(Beg, I);

  // Look for a '%' character that indicates the start of a format specifier.
  for ( ; I != E ; ++I) {
    char c = *I;
    if (c == '\0') {
      // Detect spurious null characters, which are likely errors.
      H.HandleNullChar(I);
      return true;
    }
    if (c == '%') {
      Start = I++;  // Record the start of the format specifier.
      break;
    }
  }

  // No format specifier found?
  if (!Start)
    return false;

  if (I == E) {
    // No more characters left?
    if (Warn)
      H.HandleIncompleteSpecifier(Start, E - Start);
    return true;
  }

  PrintfSpecifier FS;
  if (ParseArgPosition(H, FS, Start, I, E))
    return true;

  if (I == E) {
    // No more characters left?
    if (Warn)
      H.HandleIncompleteSpecifier(Start, E - Start);
    return true;
  }

  const char *OSLogVisibilityFlagsStart = nullptr,
             *OSLogVisibilityFlagsEnd = nullptr;
  if (*I == '{') {
    OSLogVisibilityFlagsStart = I++;
    // Find the end of the modifier.
    while (I != E && *I != '}') {
      I++;
    }
    if (I == E) {
      if (Warn)
        H.HandleIncompleteSpecifier(Start, E - Start);
      return true;
    }
    assert(*I == '}');
    OSLogVisibilityFlagsEnd = I++;

    // Just see if 'private' or 'public' is the first word. os_log itself will
    // do any further parsing.
    const char *P = OSLogVisibilityFlagsStart + 1;
    while (P < OSLogVisibilityFlagsEnd && isspace(*P))
      P++;
    const char *WordStart = P;
    while (P < OSLogVisibilityFlagsEnd && (isalnum(*P) || *P == '_'))
      P++;
    const char *WordEnd = P;
    StringRef Word(WordStart, WordEnd - WordStart);
    if (Word == "private") {
      FS.setIsPrivate(WordStart);
    } else if (Word == "public") {
      FS.setIsPublic(WordStart);
    }
  }

  // Look for flags (if any).
  bool hasMore = true;
  for ( ; I != E; ++I) {
    switch (*I) {
      default: hasMore = false; break;
      case '\'':
        // FIXME: POSIX specific.  Always accept?
        FS.setHasThousandsGrouping(I);
        break;
      case '-': FS.setIsLeftJustified(I); break;
      case '+': FS.setHasPlusPrefix(I); break;
      case ' ': FS.setHasSpacePrefix(I); break;
      case '#': FS.setHasAlternativeForm(I); break;
      case '0': FS.setHasLeadingZeros(I); break;
    }
    if (!hasMore)
      break;
  }

  if (I == E) {
    // No more characters left?
    if (Warn)
      H.HandleIncompleteSpecifier(Start, E - Start);
    return true;
  }

  // Look for the field width (if any).
  if (ParseFieldWidth(H, FS, Start, I, E,
                      FS.usesPositionalArg() ? nullptr : &argIndex))
    return true;

  if (I == E) {
    // No more characters left?
    if (Warn)
      H.HandleIncompleteSpecifier(Start, E - Start);
    return true;
  }

  // Look for the precision (if any).
  if (*I == '.') {
    ++I;
    if (I == E) {
      if (Warn)
        H.HandleIncompleteSpecifier(Start, E - Start);
      return true;
    }

    if (ParsePrecision(H, FS, Start, I, E,
                       FS.usesPositionalArg() ? nullptr : &argIndex))
      return true;

    if (I == E) {
      // No more characters left?
      if (Warn)
        H.HandleIncompleteSpecifier(Start, E - Start);
      return true;
    }
  }

  // Look for the length modifier.
  if (ParseLengthModifier(FS, I, E, LO) && I == E) {
    // No more characters left?
    if (Warn)
      H.HandleIncompleteSpecifier(Start, E - Start);
    return true;
  }

  // Look for the Objective-C modifier flags, if any.
  // We parse these here, even if they don't apply to
  // the conversion specifier, and then emit an error
  // later if the conversion specifier isn't '@'.  This
  // enables better recovery, and we don't know if
  // these flags are applicable until later.
  const char *ObjCModifierFlagsStart = nullptr,
             *ObjCModifierFlagsEnd = nullptr;
  if (*I == '[') {
    ObjCModifierFlagsStart = I;
    ++I;
    auto flagStart = I;
    for (;; ++I) {
      ObjCModifierFlagsEnd = I;
      if (I == E) {
        if (Warn)
          H.HandleIncompleteSpecifier(Start, E - Start);
        return true;
      }
      // Did we find the closing ']'?
      if (*I == ']') {
        if (ParseObjCFlags(H, FS, flagStart, I, Warn))
          return true;
        ++I;
        break;
      }
      // There are no separators defined yet for multiple
      // Objective-C modifier flags.  When those are
      // defined, this is the place to check.
    }
  }

  if (*I == '\0') {
    // Detect spurious null characters, which are likely errors.
    H.HandleNullChar(I);
    return true;
  }

  // Finally, look for the conversion specifier.
  const char *conversionPosition = I++;
  ConversionSpecifier::Kind k = ConversionSpecifier::InvalidSpecifier;
  switch (*conversionPosition) {
    default:
      break;
    // C99: 7.19.6.1 (section 8).
    case '%': k = ConversionSpecifier::PercentArg;   break;
    case 'A': k = ConversionSpecifier::AArg; break;
    case 'E': k = ConversionSpecifier::EArg; break;
    case 'F': k = ConversionSpecifier::FArg; break;
    case 'G': k = ConversionSpecifier::GArg; break;
    case 'X': k = ConversionSpecifier::XArg; break;
    case 'a': k = ConversionSpecifier::aArg; break;
    case 'c': k = ConversionSpecifier::cArg; break;
    case 'd': k = ConversionSpecifier::dArg; break;
    case 'e': k = ConversionSpecifier::eArg; break;
    case 'f': k = ConversionSpecifier::fArg; break;
    case 'g': k = ConversionSpecifier::gArg; break;
    case 'i': k = ConversionSpecifier::iArg; break;
    case 'n': k = ConversionSpecifier::nArg; break;
    case 'o': k = ConversionSpecifier::oArg; break;
    case 'p': k = ConversionSpecifier::pArg; break;
    case 's': k = ConversionSpecifier::sArg; break;
    case 'u': k = ConversionSpecifier::uArg; break;
    case 'x': k = ConversionSpecifier::xArg; break;
    // POSIX specific.
    case 'C': k = ConversionSpecifier::CArg; break;
    case 'S': k = ConversionSpecifier::SArg; break;
    // Apple extension for os_log
    case 'P':
      k = ConversionSpecifier::PArg;
      break;
    // Objective-C.
    case '@': k = ConversionSpecifier::ObjCObjArg; break;
    // Glibc specific.
    case 'm': k = ConversionSpecifier::PrintErrno; break;
    // FreeBSD kernel specific.
    case 'b':
      if (isFreeBSDKPrintf)
        k = ConversionSpecifier::FreeBSDbArg; // int followed by char *
      break;
    case 'r':
      if (isFreeBSDKPrintf)
        k = ConversionSpecifier::FreeBSDrArg; // int
      break;
    case 'y':
      if (isFreeBSDKPrintf)
        k = ConversionSpecifier::FreeBSDyArg; // int
      break;
    // Apple-specific.
    case 'D':
      if (isFreeBSDKPrintf)
        k = ConversionSpecifier::FreeBSDDArg; // void * followed by char *
      else if (Target.getTriple().isOSDarwin())
        k = ConversionSpecifier::DArg;
      break;
    case 'O':
      if (Target.getTriple().isOSDarwin())
        k = ConversionSpecifier::OArg;
      break;
    case 'U':
      if (Target.getTriple().isOSDarwin())
        k = ConversionSpecifier::UArg;
      break;
    // MS specific.
    case 'Z':
      if (Target.getTriple().isOSMSVCRT())
        k = ConversionSpecifier::ZArg;
  }
  
  // Check to see if we used the Objective-C modifier flags with
  // a conversion specifier other than '@'.
  if (k != ConversionSpecifier::ObjCObjArg &&
      k != ConversionSpecifier::InvalidSpecifier &&
      ObjCModifierFlagsStart) {
    H.HandleObjCFlagsWithNonObjCConversion(ObjCModifierFlagsStart,
                                           ObjCModifierFlagsEnd + 1,
                                           conversionPosition);
    return true;
  }

  PrintfConversionSpecifier CS(conversionPosition, k);
  FS.setConversionSpecifier(CS);
  if (CS.consumesDataArgument() && !FS.usesPositionalArg())
    FS.setArgIndex(argIndex++);
  // FreeBSD kernel specific.
  if (k == ConversionSpecifier::FreeBSDbArg ||
      k == ConversionSpecifier::FreeBSDDArg)
    argIndex++;

  if (k == ConversionSpecifier::InvalidSpecifier) {
    unsigned Len = I - Start;
    if (ParseUTF8InvalidSpecifier(Start, E, Len)) {
      CS.setEndScanList(Start + Len);
      FS.setConversionSpecifier(CS);
    }
    // Assume the conversion takes one argument.
    return !H.HandleInvalidPrintfConversionSpecifier(FS, Start, Len);
  }
  return PrintfSpecifierResult(Start, FS);
}
static PrintfSpecifierResult ParsePrintfSpecifier(FormatStringHandler &H,
                                                  const char *&Beg,
                                                  const char *E,
                                                  unsigned &argIndex,
                                                  const LangOptions &LO,
                                                  const TargetInfo &Target) {

  using namespace clang::analyze_format_string;
  using namespace clang::analyze_printf;

  const char *I = Beg;
  const char *Start = 0;
  UpdateOnReturn <const char*> UpdateBeg(Beg, I);

  // Look for a '%' character that indicates the start of a format specifier.
  for ( ; I != E ; ++I) {
    char c = *I;
    if (c == '\0') {
      // Detect spurious null characters, which are likely errors.
      H.HandleNullChar(I);
      return true;
    }
    if (c == '%') {
      Start = I++;  // Record the start of the format specifier.
      break;
    }
  }

  // No format specifier found?
  if (!Start)
    return false;

  if (I == E) {
    // No more characters left?
    H.HandleIncompleteSpecifier(Start, E - Start);
    return true;
  }

  PrintfSpecifier FS;
  if (ParseArgPosition(H, FS, Start, I, E))
    return true;

  if (I == E) {
    // No more characters left?
    H.HandleIncompleteSpecifier(Start, E - Start);
    return true;
  }

  // Look for flags (if any).
  bool hasMore = true;
  for ( ; I != E; ++I) {
    switch (*I) {
      default: hasMore = false; break;
      case '\'':
        // FIXME: POSIX specific.  Always accept?
        FS.setHasThousandsGrouping(I);
        break;
      case '-': FS.setIsLeftJustified(I); break;
      case '+': FS.setHasPlusPrefix(I); break;
      case ' ': FS.setHasSpacePrefix(I); break;
      case '#': FS.setHasAlternativeForm(I); break;
      case '0': FS.setHasLeadingZeros(I); break;
    }
    if (!hasMore)
      break;
  }

  if (I == E) {
    // No more characters left?
    H.HandleIncompleteSpecifier(Start, E - Start);
    return true;
  }

  // Look for the field width (if any).
  if (ParseFieldWidth(H, FS, Start, I, E,
                      FS.usesPositionalArg() ? 0 : &argIndex))
    return true;

  if (I == E) {
    // No more characters left?
    H.HandleIncompleteSpecifier(Start, E - Start);
    return true;
  }

  // Look for the precision (if any).
  if (*I == '.') {
    ++I;
    if (I == E) {
      H.HandleIncompleteSpecifier(Start, E - Start);
      return true;
    }

    if (ParsePrecision(H, FS, Start, I, E,
                       FS.usesPositionalArg() ? 0 : &argIndex))
      return true;

    if (I == E) {
      // No more characters left?
      H.HandleIncompleteSpecifier(Start, E - Start);
      return true;
    }
  }

  // Look for the length modifier.
  if (ParseLengthModifier(FS, I, E, LO) && I == E) {
    // No more characters left?
    H.HandleIncompleteSpecifier(Start, E - Start);
    return true;
  }

  if (*I == '\0') {
    // Detect spurious null characters, which are likely errors.
    H.HandleNullChar(I);
    return true;
  }

  // Finally, look for the conversion specifier.
  const char *conversionPosition = I++;
  ConversionSpecifier::Kind k = ConversionSpecifier::InvalidSpecifier;
  switch (*conversionPosition) {
    default:
      break;
    // C99: 7.19.6.1 (section 8).
    case '%': k = ConversionSpecifier::PercentArg;   break;
    case 'A': k = ConversionSpecifier::AArg; break;
    case 'E': k = ConversionSpecifier::EArg; break;
    case 'F': k = ConversionSpecifier::FArg; break;
    case 'G': k = ConversionSpecifier::GArg; break;
    case 'X': k = ConversionSpecifier::XArg; break;
    case 'a': k = ConversionSpecifier::aArg; break;
    case 'c': k = ConversionSpecifier::cArg; break;
    case 'd': k = ConversionSpecifier::dArg; break;
    case 'e': k = ConversionSpecifier::eArg; break;
    case 'f': k = ConversionSpecifier::fArg; break;
    case 'g': k = ConversionSpecifier::gArg; break;
    case 'i': k = ConversionSpecifier::iArg; break;
    case 'n': k = ConversionSpecifier::nArg; break;
    case 'o': k = ConversionSpecifier::oArg; break;
    case 'p': k = ConversionSpecifier::pArg; break;
    case 's': k = ConversionSpecifier::sArg; break;
    case 'u': k = ConversionSpecifier::uArg; break;
    case 'x': k = ConversionSpecifier::xArg; break;
    // POSIX specific.
    case 'C': k = ConversionSpecifier::CArg; break;
    case 'S': k = ConversionSpecifier::SArg; break;
    // Objective-C.
    case '@': k = ConversionSpecifier::ObjCObjArg; break;
    // Glibc specific.
    case 'm': k = ConversionSpecifier::PrintErrno; break;
    // Apple-specific
    case 'D':
      if (Target.getTriple().isOSDarwin())
        k = ConversionSpecifier::DArg;
      break;
    case 'O':
      if (Target.getTriple().isOSDarwin())
        k = ConversionSpecifier::OArg;
      break;
    case 'U':
      if (Target.getTriple().isOSDarwin())
        k = ConversionSpecifier::UArg;
      break;
  }
  PrintfConversionSpecifier CS(conversionPosition, k);
  FS.setConversionSpecifier(CS);
  if (CS.consumesDataArgument() && !FS.usesPositionalArg())
    FS.setArgIndex(argIndex++);

  if (k == ConversionSpecifier::InvalidSpecifier) {
    // Assume the conversion takes one argument.
    return !H.HandleInvalidPrintfConversionSpecifier(FS, Start, I - Start);
  }
  return PrintfSpecifierResult(Start, FS);
}
static PrintfSpecifierResult ParsePrintfSpecifier(FormatStringHandler &H,
                                                  const char *&Beg,
                                                  const char *E,
                                                  unsigned &argIndex,
                                                  const LangOptions &LO,
                                                  const TargetInfo &Target,
                                                  bool Warn,
                                                  bool isFreeBSDKPrintf) {

  using namespace clang::analyze_format_string;
  using namespace clang::analyze_printf;

  const char *I = Beg;
  const char *Start = nullptr;
  UpdateOnReturn <const char*> UpdateBeg(Beg, I);

  // Look for a '%' character that indicates the start of a format specifier.
  for ( ; I != E ; ++I) {
    char c = *I;
    if (c == '\0') {
      // Detect spurious null characters, which are likely errors.
      H.HandleNullChar(I);
      return true;
    }
    if (c == '%') {
      Start = I++;  // Record the start of the format specifier.
      break;
    }
  }

  // No format specifier found?
  if (!Start)
    return false;

  if (I == E) {
    // No more characters left?
    if (Warn)
      H.HandleIncompleteSpecifier(Start, E - Start);
    return true;
  }

  PrintfSpecifier FS;
  if (ParseArgPosition(H, FS, Start, I, E))
    return true;

  if (I == E) {
    // No more characters left?
    if (Warn)
      H.HandleIncompleteSpecifier(Start, E - Start);
    return true;
  }

  if (*I == '{') {
    ++I;
    unsigned char PrivacyFlags = 0;
    StringRef MatchedStr;

    do {
      StringRef Str(I, E - I);
      std::string Match = "^[\t\n\v\f\r ]*(private|public)[\t\n\v\f\r ]*(,|})";
      llvm::Regex R(Match);
      SmallVector<StringRef, 2> Matches;

      if (R.match(Str, &Matches)) {
        MatchedStr = Matches[1];
        I += Matches[0].size();

        // Set the privacy flag if the privacy annotation in the
        // comma-delimited segment is at least as strict as the privacy
        // annotations in previous comma-delimited segments.
        if (MatchedStr.equals("private"))
          PrivacyFlags = clang::analyze_os_log::OSLogBufferItem::IsPrivate;
        else if (PrivacyFlags == 0 && MatchedStr.equals("public"))
          PrivacyFlags = clang::analyze_os_log::OSLogBufferItem::IsPublic;
      } else {
        size_t CommaOrBracePos =
            Str.find_if([](char c) { return c == ',' || c == '}'; });

        if (CommaOrBracePos == StringRef::npos) {
          // Neither a comma nor the closing brace was found.
          if (Warn)
            H.HandleIncompleteSpecifier(Start, E - Start);
          return true;
        }

        I += CommaOrBracePos + 1;
      }
      // Continue until the closing brace is found.
    } while (*(I - 1) == ',');

    // Set the privacy flag.
    switch (PrivacyFlags) {
    case 0:
      break;
    case clang::analyze_os_log::OSLogBufferItem::IsPrivate:
      FS.setIsPrivate(MatchedStr.data());
      break;
    case clang::analyze_os_log::OSLogBufferItem::IsPublic:
      FS.setIsPublic(MatchedStr.data());
      break;
    default:
      llvm_unreachable("Unexpected privacy flag value");
    }
  }

  // Look for flags (if any).
  bool hasMore = true;
  for ( ; I != E; ++I) {
    switch (*I) {
      default: hasMore = false; break;
      case '\'':
        // FIXME: POSIX specific.  Always accept?
        FS.setHasThousandsGrouping(I);
        break;
      case '-': FS.setIsLeftJustified(I); break;
      case '+': FS.setHasPlusPrefix(I); break;
      case ' ': FS.setHasSpacePrefix(I); break;
      case '#': FS.setHasAlternativeForm(I); break;
      case '0': FS.setHasLeadingZeros(I); break;
    }
    if (!hasMore)
      break;
  }

  if (I == E) {
    // No more characters left?
    if (Warn)
      H.HandleIncompleteSpecifier(Start, E - Start);
    return true;
  }

  // Look for the field width (if any).
  if (ParseFieldWidth(H, FS, Start, I, E,
                      FS.usesPositionalArg() ? nullptr : &argIndex))
    return true;

  if (I == E) {
    // No more characters left?
    if (Warn)
      H.HandleIncompleteSpecifier(Start, E - Start);
    return true;
  }

  // Look for the precision (if any).
  if (*I == '.') {
    ++I;
    if (I == E) {
      if (Warn)
        H.HandleIncompleteSpecifier(Start, E - Start);
      return true;
    }

    if (ParsePrecision(H, FS, Start, I, E,
                       FS.usesPositionalArg() ? nullptr : &argIndex))
      return true;

    if (I == E) {
      // No more characters left?
      if (Warn)
        H.HandleIncompleteSpecifier(Start, E - Start);
      return true;
    }
  }

  // Look for the length modifier.
  if (ParseLengthModifier(FS, I, E, LO) && I == E) {
    // No more characters left?
    if (Warn)
      H.HandleIncompleteSpecifier(Start, E - Start);
    return true;
  }

  // Look for the Objective-C modifier flags, if any.
  // We parse these here, even if they don't apply to
  // the conversion specifier, and then emit an error
  // later if the conversion specifier isn't '@'.  This
  // enables better recovery, and we don't know if
  // these flags are applicable until later.
  const char *ObjCModifierFlagsStart = nullptr,
             *ObjCModifierFlagsEnd = nullptr;
  if (*I == '[') {
    ObjCModifierFlagsStart = I;
    ++I;
    auto flagStart = I;
    for (;; ++I) {
      ObjCModifierFlagsEnd = I;
      if (I == E) {
        if (Warn)
          H.HandleIncompleteSpecifier(Start, E - Start);
        return true;
      }
      // Did we find the closing ']'?
      if (*I == ']') {
        if (ParseObjCFlags(H, FS, flagStart, I, Warn))
          return true;
        ++I;
        break;
      }
      // There are no separators defined yet for multiple
      // Objective-C modifier flags.  When those are
      // defined, this is the place to check.
    }
  }

  if (*I == '\0') {
    // Detect spurious null characters, which are likely errors.
    H.HandleNullChar(I);
    return true;
  }

  // Finally, look for the conversion specifier.
  const char *conversionPosition = I++;
  ConversionSpecifier::Kind k = ConversionSpecifier::InvalidSpecifier;
  switch (*conversionPosition) {
    default:
      break;
    // C99: 7.19.6.1 (section 8).
    case '%': k = ConversionSpecifier::PercentArg;   break;
    case 'A': k = ConversionSpecifier::AArg; break;
    case 'E': k = ConversionSpecifier::EArg; break;
    case 'F': k = ConversionSpecifier::FArg; break;
    case 'G': k = ConversionSpecifier::GArg; break;
    case 'X': k = ConversionSpecifier::XArg; break;
    case 'a': k = ConversionSpecifier::aArg; break;
    case 'c': k = ConversionSpecifier::cArg; break;
    case 'd': k = ConversionSpecifier::dArg; break;
    case 'e': k = ConversionSpecifier::eArg; break;
    case 'f': k = ConversionSpecifier::fArg; break;
    case 'g': k = ConversionSpecifier::gArg; break;
    case 'i': k = ConversionSpecifier::iArg; break;
    case 'n': k = ConversionSpecifier::nArg; break;
    case 'o': k = ConversionSpecifier::oArg; break;
    case 'p': k = ConversionSpecifier::pArg; break;
    case 's': k = ConversionSpecifier::sArg; break;
    case 'u': k = ConversionSpecifier::uArg; break;
    case 'x': k = ConversionSpecifier::xArg; break;
    // POSIX specific.
    case 'C': k = ConversionSpecifier::CArg; break;
    case 'S': k = ConversionSpecifier::SArg; break;
    // Apple extension for os_log
    case 'P':
      k = ConversionSpecifier::PArg;
      break;
    // Objective-C.
    case '@': k = ConversionSpecifier::ObjCObjArg; break;
    // Glibc specific.
    case 'm': k = ConversionSpecifier::PrintErrno; break;
    // FreeBSD kernel specific.
    case 'b':
      if (isFreeBSDKPrintf)
        k = ConversionSpecifier::FreeBSDbArg; // int followed by char *
      break;
    case 'r':
      if (isFreeBSDKPrintf)
        k = ConversionSpecifier::FreeBSDrArg; // int
      break;
    case 'y':
      if (isFreeBSDKPrintf)
        k = ConversionSpecifier::FreeBSDyArg; // int
      break;
    // Apple-specific.
    case 'D':
      if (isFreeBSDKPrintf)
        k = ConversionSpecifier::FreeBSDDArg; // void * followed by char *
      else if (Target.getTriple().isOSDarwin())
        k = ConversionSpecifier::DArg;
      break;
    case 'O':
      if (Target.getTriple().isOSDarwin())
        k = ConversionSpecifier::OArg;
      break;
    case 'U':
      if (Target.getTriple().isOSDarwin())
        k = ConversionSpecifier::UArg;
      break;
    // MS specific.
    case 'Z':
      if (Target.getTriple().isOSMSVCRT())
        k = ConversionSpecifier::ZArg;
  }
  
  // Check to see if we used the Objective-C modifier flags with
  // a conversion specifier other than '@'.
  if (k != ConversionSpecifier::ObjCObjArg &&
      k != ConversionSpecifier::InvalidSpecifier &&
      ObjCModifierFlagsStart) {
    H.HandleObjCFlagsWithNonObjCConversion(ObjCModifierFlagsStart,
                                           ObjCModifierFlagsEnd + 1,
                                           conversionPosition);
    return true;
  }

  PrintfConversionSpecifier CS(conversionPosition, k);
  FS.setConversionSpecifier(CS);
  if (CS.consumesDataArgument() && !FS.usesPositionalArg())
    FS.setArgIndex(argIndex++);
  // FreeBSD kernel specific.
  if (k == ConversionSpecifier::FreeBSDbArg ||
      k == ConversionSpecifier::FreeBSDDArg)
    argIndex++;

  if (k == ConversionSpecifier::InvalidSpecifier) {
    unsigned Len = I - Start;
    if (ParseUTF8InvalidSpecifier(Start, E, Len)) {
      CS.setEndScanList(Start + Len);
      FS.setConversionSpecifier(CS);
    }
    // Assume the conversion takes one argument.
    return !H.HandleInvalidPrintfConversionSpecifier(FS, Start, Len);
  }
  return PrintfSpecifierResult(Start, FS);
}