//== PrintfFormatString.cpp - Analysis of printf format strings --*- C++ -*-==//

//

// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.

// See https://llvm.org/LICENSE.txt for license information.

// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception

//

//===----------------------------------------------------------------------===//

//

// Handling of format string in printf and friends.  The structure of format

// strings for fprintf() are described in C99 7.19.6.1.

//

//===----------------------------------------------------------------------===//

#include "FormatStringParsing.h"

#include "clang/AST/FormatString.h"

#include "clang/AST/OSLog.h"

#include "clang/Basic/TargetInfo.h"

#include "llvm/Support/Regex.h"

using clang::analyze_format_string::ArgType;

using clang::analyze_format_string::FormatStringHandler;

using clang::analyze_format_string::LengthModifier;

using clang::analyze_format_string::OptionalAmount;

using clang::analyze_format_string::ConversionSpecifier;

using clang::analyze_printf::PrintfSpecifier;

using namespace clang;

typedef clang::analyze_format_string::SpecifierResult<PrintfSpecifier>

        PrintfSpecifierResult;

//===----------------------------------------------------------------------===//

// Methods for parsing format strings.

//===----------------------------------------------------------------------===//

using analyze_format_string::ParseNonPositionAmount;

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 ; 
++I609k
) {

    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 = "^[[:space:]]*"

                          "(private|public|sensitive|mask\\.[^[:space:],}]*)"

                          "[[:space:]]*(,|})";

      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.startswith("mask")) {

          StringRef MaskType = MatchedStr.substr(sizeof("mask.") - 1);

          unsigned Size = MaskType.size();

          if (Warn && (Size == 0 || 
Size > 816
))

            H.handleInvalidMaskType(MaskType);

          FS.setMaskType(MaskType);

        } else if (MatchedStr.equals("sensitive"))

          PrivacyFlags = clang::analyze_os_log::OSLogBufferItem::IsSensitive;

        else if (PrivacyFlags !=

                 clang::analyze_os_log::OSLogBufferItem::IsSensitive &&

                 MatchedStr.equals("private"))

          PrivacyFlags = clang::analyze_os_log::OSLogBufferItem::IsPrivate;

        else if (PrivacyFlags == 0 && 
MatchedStr.equals("public")20
)

          PrivacyFlags = clang::analyze_os_log::OSLogBufferItem::IsPublic;

      } else {

        size_t CommaOrBracePos =

            Str.find_if([](char c) { return c == ',' || 
c == '}'272
; });

        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;

    case clang::analyze_os_log::OSLogBufferItem::IsSensitive:

      FS.setIsSensitive(MatchedStr.data());

      break;

    default:

      llvm_unreachable("Unexpected privacy flag value");

    }

  }

  // Look for flags (if any).

  bool hasMore = true;

  for ( ; I != E; 
++I254
) {

    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() ? 
nullptr55
 : &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() ? 
nullptr8
 : &argIndex))

      return true;

    if (I == E) {

      // No more characters left?

      if (Warn)

        H.HandleIncompleteSpecifier(Start, E - Start);

      return true;

    }

  }

  if (ParseVectorModifier(H, FS, I, E, LO))

    return true;

  // Look for the length modifier.

  if (ParseLengthModifier(FS, I, E, LO) && 
I == E6.12k
) {

    // 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 (;; 
++I40
) {

      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':

      // Not handled, but reserved in OpenCL.

      if (!LO.OpenCL)

        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;

      break;

  }

  // 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()30.7k
)

    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);

}

bool clang::analyze_format_string::ParsePrintfString(FormatStringHandler &H,

                                                     const char *I,

                                                     const char *E,

                                                     const LangOptions &LO,

                                                     const TargetInfo &Target,

                                                     bool isFreeBSDKPrintf) {

  unsigned argIndex = 0;

  // Keep looking for a format specifier until we have exhausted the string.

  while (I != E) {

    const PrintfSpecifierResult &FSR = ParsePrintfSpecifier(H, I, E, argIndex,

                                                            LO, Target, true,

                                                            isFreeBSDKPrintf);

    // Did a fail-stop error of any kind occur when parsing the specifier?

    // If so, don't do any more processing.

    if (FSR.shouldStop())

      return true;

    // Did we exhaust the string or encounter an error that

    // we can recover from?

    if (!FSR.hasValue())

      continue;

    // We have a format specifier.  Pass it to the callback.

    if (!H.HandlePrintfSpecifier(FSR.getValue(), FSR.getStart(),

                                 I - FSR.getStart()))

      return true;

  }

  assert(I == E && "Format string not exhausted");

  return false;

}

bool clang::analyze_format_string::ParseFormatStringHasSArg(const char *I,

                                                            const char *E,

                                                            const LangOptions &LO,

                                                            const TargetInfo &Target) {

  unsigned argIndex = 0;

  // Keep looking for a %s format specifier until we have exhausted the string.

  FormatStringHandler H;

  while (I != E) {

    const PrintfSpecifierResult &FSR = ParsePrintfSpecifier(H, I, E, argIndex,

                                                            LO, Target, false,

                                                            false);

    // Did a fail-stop error of any kind occur when parsing the specifier?

    // If so, don't do any more processing.

    if (FSR.shouldStop())

      return false;

    // Did we exhaust the string or encounter an error that

    // we can recover from?

    if (!FSR.hasValue())

      continue;

    const analyze_printf::PrintfSpecifier &FS = FSR.getValue();

    // Return true if this a %s format specifier.

    if (FS.getConversionSpecifier().getKind() == ConversionSpecifier::Kind::sArg)

      return true;

  }

  return false;

}

bool clang::analyze_format_string::parseFormatStringHasFormattingSpecifiers(

    const char *Begin, const char *End, const LangOptions &LO,

    const TargetInfo &Target) {

  unsigned ArgIndex = 0;

  // Keep looking for a formatting specifier until we have exhausted the string.

  FormatStringHandler H;

  while (Begin != End) {

    const PrintfSpecifierResult &FSR =

        ParsePrintfSpecifier(H, Begin, End, ArgIndex, LO, Target, false, false);

    if (FSR.shouldStop())

      break;

    if (FSR.hasValue())

      return true;

  }

  return false;

}

//===----------------------------------------------------------------------===//

// Methods on PrintfSpecifier.

//===----------------------------------------------------------------------===//

ArgType PrintfSpecifier::getScalarArgType(ASTContext &Ctx,

                                          bool IsObjCLiteral) const {

  if (CS.getKind() == ConversionSpecifier::cArg)

    switch (LM.getKind()) {

      case LengthModifier::None:

        return Ctx.IntTy;

      case LengthModifier::AsLong:

      case LengthModifier::AsWide:

        return ArgType(ArgType::WIntTy, "wint_t");

      case LengthModifier::AsShort:

        if (Ctx.getTargetInfo().getTriple().isOSMSVCRT())

          return Ctx.IntTy;

        LLVM_FALLTHROUGH;

      default:

        return ArgType::Invalid();

    }

  if (CS.isIntArg())

    switch (LM.getKind()) {

      case LengthModifier::AsLongDouble:

        // GNU extension.

        return Ctx.LongLongTy;

      case LengthModifier::None:

      case LengthModifier::AsShortLong:

        return Ctx.IntTy;

      case LengthModifier::AsInt32:

        return ArgType(Ctx.IntTy, "__int32");

      case LengthModifier::AsChar:

        return ArgType::AnyCharTy;

      case LengthModifier::AsShort: return Ctx.ShortTy;

      case LengthModifier::AsLong: return Ctx.LongTy;

      case LengthModifier::AsLongLong:

      case LengthModifier::AsQuad:

        return Ctx.LongLongTy;

      case LengthModifier::AsInt64:

        return ArgType(Ctx.LongLongTy, "__int64");

      case LengthModifier::AsIntMax:

        return ArgType(Ctx.getIntMaxType(), "intmax_t");

      case LengthModifier::AsSizeT:

        return ArgType::makeSizeT(ArgType(Ctx.getSignedSizeType(), "ssize_t"));

      case LengthModifier::AsInt3264:

        return Ctx.getTargetInfo().getTriple().isArch64Bit()

                   ? ArgType(Ctx.LongLongTy, "__int64")

                   : ArgType(Ctx.IntTy, "__int32");

      case LengthModifier::AsPtrDiff:

        return ArgType::makePtrdiffT(

            ArgType(Ctx.getPointerDiffType(), "ptrdiff_t"));

      case LengthModifier::AsAllocate:

      case LengthModifier::AsMAllocate:

      case LengthModifier::AsWide:

        return ArgType::Invalid();

    }

  if (CS.isUIntArg())

    switch (LM.getKind()) {

      case LengthModifier::AsLongDouble:

        // GNU extension.

        return Ctx.UnsignedLongLongTy;

      case LengthModifier::None:

      case LengthModifier::AsShortLong:

        return Ctx.UnsignedIntTy;

      case LengthModifier::AsInt32:

        return ArgType(Ctx.UnsignedIntTy, "unsigned __int32");

      case LengthModifier::AsChar: return Ctx.UnsignedCharTy;

      case LengthModifier::AsShort: return Ctx.UnsignedShortTy;

      case LengthModifier::AsLong: return Ctx.UnsignedLongTy;

      case LengthModifier::AsLongLong:

      case LengthModifier::AsQuad:

        return Ctx.UnsignedLongLongTy;

      case LengthModifier::AsInt64:

        return ArgType(Ctx.UnsignedLongLongTy, "unsigned __int64");

      case LengthModifier::AsIntMax:

        return ArgType(Ctx.getUIntMaxType(), "uintmax_t");

      case LengthModifier::AsSizeT:

        return ArgType::makeSizeT(ArgType(Ctx.getSizeType(), "size_t"));

      case LengthModifier::AsInt3264:

        return Ctx.getTargetInfo().getTriple().isArch64Bit()

                   ? ArgType(Ctx.UnsignedLongLongTy, "unsigned __int64")

                   : ArgType(Ctx.UnsignedIntTy, "unsigned __int32");

      case LengthModifier::AsPtrDiff:

        return ArgType::makePtrdiffT(

            ArgType(Ctx.getUnsignedPointerDiffType(), "unsigned ptrdiff_t"));

      case LengthModifier::AsAllocate:

      case LengthModifier::AsMAllocate:

      case LengthModifier::AsWide:

        return ArgType::Invalid();

    }

  if (CS.isDoubleArg()) {

    if (!VectorNumElts.isInvalid()) {

      switch (LM.getKind()) {

      case LengthModifier::AsShort:

        return Ctx.HalfTy;

      case LengthModifier::AsShortLong:

        return Ctx.FloatTy;

      case LengthModifier::AsLong:

      default:

        return Ctx.DoubleTy;

      }

    }

    if (LM.getKind() == LengthModifier::AsLongDouble)

      return Ctx.LongDoubleTy;

    return Ctx.DoubleTy;

  }

  if (CS.getKind() == ConversionSpecifier::nArg) {

    switch (LM.getKind()) {

      case LengthModifier::None:

        return ArgType::PtrTo(Ctx.IntTy);

      case LengthModifier::AsChar:

        return ArgType::PtrTo(Ctx.SignedCharTy);

      case LengthModifier::AsShort:

        return ArgType::PtrTo(Ctx.ShortTy);

      case LengthModifier::AsLong:

        return ArgType::PtrTo(Ctx.LongTy);

      case LengthModifier::AsLongLong:

      case LengthModifier::AsQuad:

        return ArgType::PtrTo(Ctx.LongLongTy);

      case LengthModifier::AsIntMax:

        return ArgType::PtrTo(ArgType(Ctx.getIntMaxType(), "intmax_t"));

      case LengthModifier::AsSizeT:

        return ArgType::PtrTo(ArgType(Ctx.getSignedSizeType(), "ssize_t"));

      case LengthModifier::AsPtrDiff:

        return ArgType::PtrTo(ArgType(Ctx.getPointerDiffType(), "ptrdiff_t"));

      case LengthModifier::AsLongDouble:

        return ArgType(); // FIXME: Is this a known extension?

      case LengthModifier::AsAllocate:

      case LengthModifier::AsMAllocate:

      case LengthModifier::AsInt32:

      case LengthModifier::AsInt3264:

      case LengthModifier::AsInt64:

      case LengthModifier::AsWide:

        return ArgType::Invalid();

      case LengthModifier::AsShortLong:

        llvm_unreachable("only used for OpenCL which doesn not handle nArg");

    }

  }

  switch (CS.getKind()) {

    case ConversionSpecifier::sArg:

      if (LM.getKind() == LengthModifier::AsWideChar) {

        if (IsObjCLiteral)

          return ArgType(Ctx.getPointerType(Ctx.UnsignedShortTy.withConst()),

                         "const unichar *");

        return ArgType(ArgType::WCStrTy, "wchar_t *");

      }

      if (LM.getKind() == LengthModifier::AsWide)

        return ArgType(ArgType::WCStrTy, "wchar_t *");

      return ArgType::CStrTy;

    case ConversionSpecifier::SArg:

      if (IsObjCLiteral)

        return ArgType(Ctx.getPointerType(Ctx.UnsignedShortTy.withConst()),

                       "const unichar *");

      if (Ctx.getTargetInfo().getTriple().isOSMSVCRT() &&

          LM.getKind() == LengthModifier::AsShort)

        return ArgType::CStrTy;

      return ArgType(ArgType::WCStrTy, "wchar_t *");

    case ConversionSpecifier::CArg:

      if (IsObjCLiteral)

        return ArgType(Ctx.UnsignedShortTy, "unichar");

      if (Ctx.getTargetInfo().getTriple().isOSMSVCRT() &&

          LM.getKind() == LengthModifier::AsShort)

        return Ctx.IntTy;

      return ArgType(Ctx.WideCharTy, "wchar_t");

    case ConversionSpecifier::pArg:

    case ConversionSpecifier::PArg:

      return ArgType::CPointerTy;

    case ConversionSpecifier::ObjCObjArg:

      return ArgType::ObjCPointerTy;

    default:

      break;

  }

  // FIXME: Handle other cases.

  return ArgType();

}

ArgType PrintfSpecifier::getArgType(ASTContext &Ctx,

                                    bool IsObjCLiteral) const {

  const PrintfConversionSpecifier &CS = getConversionSpecifier();

  if (!CS.consumesDataArgument())

    return ArgType::Invalid();

  ArgType ScalarTy = getScalarArgType(Ctx, IsObjCLiteral);

  if (!ScalarTy.isValid() || 
VectorNumElts.isInvalid()25.9k
)

    return ScalarTy;

  return ScalarTy.makeVectorType(Ctx, VectorNumElts.getConstantAmount());

}

bool PrintfSpecifier::fixType(QualType QT, const LangOptions &LangOpt,

                              ASTContext &Ctx, bool IsObjCLiteral) {

  // %n is different from other conversion specifiers; don't try to fix it.

  if (CS.getKind() == ConversionSpecifier::nArg)

    return false;

  // Handle Objective-C objects first. Note that while the '%@' specifier will

  // not warn for structure pointer or void pointer arguments (because that's

  // how CoreFoundation objects are implemented), we only show a fixit for '%@'

  // if we know it's an object (block, id, class, or __attribute__((NSObject))).

  if (QT->isObjCRetainableType()) {

    if (!IsObjCLiteral)

      return false;

    CS.setKind(ConversionSpecifier::ObjCObjArg);

    // Disable irrelevant flags

    HasThousandsGrouping = false;

    HasPlusPrefix = false;

    HasSpacePrefix = false;

    HasAlternativeForm = false;

    HasLeadingZeroes = false;

    Precision.setHowSpecified(OptionalAmount::NotSpecified);

    LM.setKind(LengthModifier::None);

    return true;

  }

  // Handle strings next (char *, wchar_t *)

  if (QT->isPointerType() && 
(QT->getPointeeType()->isAnyCharacterType())3.63k
) {

    CS.setKind(ConversionSpecifier::sArg);

    // Disable irrelevant flags

    HasAlternativeForm = 0;

    HasLeadingZeroes = 0;

    // Set the long length modifier for wide characters

    if (QT->getPointeeType()->isWideCharType())

      LM.setKind(LengthModifier::AsWideChar);

    else

      LM.setKind(LengthModifier::None);

    return true;

  }

  // If it's an enum, get its underlying type.

  if (const EnumType *ETy = QT->getAs<EnumType>())

    QT = ETy->getDecl()->getIntegerType();

  const BuiltinType *BT = QT->getAs<BuiltinType>();

  if (!BT) {

    const VectorType *VT = QT->getAs<VectorType>();

    if (VT) {

      QT = VT->getElementType();

      BT = QT->getAs<BuiltinType>();

      VectorNumElts = OptionalAmount(VT->getNumElements());

    }

  }

  // We can only work with builtin types.

  if (!BT)

    return false;

  // Set length modifier

  switch (BT->getKind()) {

  case BuiltinType::Bool:

  case BuiltinType::WChar_U:

  case BuiltinType::WChar_S:

  case BuiltinType::Char8: // FIXME: Treat like 'char'?

  case BuiltinType::Char16:

  case BuiltinType::Char32:

  case BuiltinType::UInt128:

  case BuiltinType::Int128:

  case BuiltinType::Half:

  case BuiltinType::BFloat16:

  case BuiltinType::Float16:

  case BuiltinType::Float128:

  case BuiltinType::ShortAccum:

  case BuiltinType::Accum:

  case BuiltinType::LongAccum:

  case BuiltinType::UShortAccum:

  case BuiltinType::UAccum:

  case BuiltinType::ULongAccum:

  case BuiltinType::ShortFract:

  case BuiltinType::Fract:

  case BuiltinType::LongFract:

  case BuiltinType::UShortFract:

  case BuiltinType::UFract:

  case BuiltinType::ULongFract:

  case BuiltinType::SatShortAccum:

  case BuiltinType::SatAccum:

  case BuiltinType::SatLongAccum:

  case BuiltinType::SatUShortAccum:

  case BuiltinType::SatUAccum:

  case BuiltinType::SatULongAccum:

  case BuiltinType::SatShortFract:

  case BuiltinType::SatFract:

  case BuiltinType::SatLongFract:

  case BuiltinType::SatUShortFract:

  case BuiltinType::SatUFract:

  case BuiltinType::SatULongFract:

    // Various types which are non-trivial to correct.

    return false;

#define IMAGE_TYPE(ImgType, Id, SingletonId, Access, Suffix) \

  case BuiltinType::Id:

#include 
"clang/Basic/OpenCLImageTypes.def"35

#define EXT_OPAQUE_TYPE(ExtType, Id, Ext) \

  case BuiltinType::Id:

#include 
"clang/Basic/OpenCLExtensionTypes.def"4

#define SVE_TYPE(Name, Id, SingletonId) \

  case BuiltinType::Id:

#include 
"clang/Basic/AArch64SVEACLETypes.def"4

#define SIGNED_TYPE(Id, SingletonId)

#define UNSIGNED_TYPE(Id, SingletonId)

#define FLOATING_TYPE(Id, SingletonId)

#define BUILTIN_TYPE(Id, SingletonId) \

  case BuiltinType::Id:

#include "clang/AST/BuiltinTypes.def"

    // Misc other stuff which doesn't make sense here.

    return false;

  case BuiltinType::UInt:

  case BuiltinType::Int:

  case BuiltinType::Float:

    LM.setKind(VectorNumElts.isInvalid() ?

               LengthModifier::None : 
LengthModifier::AsShortLong45
);

    break;

  case BuiltinType::Double:

    LM.setKind(VectorNumElts.isInvalid() ?

               LengthModifier::None : 
LengthModifier::AsLong1
);

    break;

  case BuiltinType::Char_U:

  case BuiltinType::UChar:

  case BuiltinType::Char_S:

  case BuiltinType::SChar:

    LM.setKind(LengthModifier::AsChar);

    break;

  case BuiltinType::Short:

  case BuiltinType::UShort:

    LM.setKind(LengthModifier::AsShort);

    break;

  case BuiltinType::Long:

  case BuiltinType::ULong:

    LM.setKind(LengthModifier::AsLong);

    break;

  case BuiltinType::LongLong:

  case BuiltinType::ULongLong:

    LM.setKind(LengthModifier::AsLongLong);

    break;

  case BuiltinType::LongDouble:

    LM.setKind(LengthModifier::AsLongDouble);

    break;

  }

  // Handle size_t, ptrdiff_t, etc. that have dedicated length modifiers in C99.

  if (isa<TypedefType>(QT) && 
(47
LangOpt.C9947
 || 
LangOpt.CPlusPlus1116
))

    namedTypeToLengthModifier(QT, LM);

  // If fixing the length modifier was enough, we might be done.

  if (hasValidLengthModifier(Ctx.getTargetInfo(), LangOpt)) {

    // If we're going to offer a fix anyway, make sure the sign matches.

    switch (CS.getKind()) {

    case ConversionSpecifier::uArg:

    case ConversionSpecifier::UArg:

      if (QT->isSignedIntegerType())

        CS.setKind(clang::analyze_format_string::ConversionSpecifier::dArg);

      break;

    case ConversionSpecifier::dArg:

    case ConversionSpecifier::DArg:

    case ConversionSpecifier::iArg:

      if (QT->isUnsignedIntegerType() && 
!HasPlusPrefix24
)

        CS.setKind(clang::analyze_format_string::ConversionSpecifier::uArg);

      break;

    default:

      // Other specifiers do not have signed/unsigned variants.

      break;

    }

    const analyze_printf::ArgType &ATR = getArgType(Ctx, IsObjCLiteral);

    if (ATR.isValid() && 
ATR.matchesType(Ctx, QT)542
)

      return true;

  }

  // Set conversion specifier and disable any flags which do not apply to it.

  // Let typedefs to char fall through to int, as %c is silly for uint8_t.

  if (!isa<TypedefType>(QT) && 
QT->isCharType()342
) {

    CS.setKind(ConversionSpecifier::cArg);

    LM.setKind(LengthModifier::None);

    Precision.setHowSpecified(OptionalAmount::NotSpecified);

    HasAlternativeForm = 0;

    HasLeadingZeroes = 0;

    HasPlusPrefix = 0;

  }

  // Test for Floating type first as LongDouble can pass isUnsignedIntegerType

  else if (QT->isRealFloatingType()) {

    CS.setKind(ConversionSpecifier::fArg);

  }

  else if (QT->isSignedIntegerType()) {

    CS.setKind(ConversionSpecifier::dArg);

    HasAlternativeForm = 0;

  }

  else if (QT->isUnsignedIntegerType()) {

    CS.setKind(ConversionSpecifier::uArg);

    HasAlternativeForm = 0;

    HasPlusPrefix = 0;

  } else {

    llvm_unreachable("Unexpected type");

  }

  return true;

}

void PrintfSpecifier::toString(raw_ostream &os) const {

  // Whilst some features have no defined order, we are using the order

  // appearing in the C99 standard (ISO/IEC 9899:1999 (E) 7.19.6.1)

  os << "%";

  // Positional args

  if (usesPositionalArg()) {

    os << getPositionalArgIndex() << "$";

  }

  // Conversion flags

  if (IsLeftJustified)    
os << "-"0
;

  if (HasPlusPrefix)      
os << "+"3
;

  if (HasSpacePrefix)     
os << " "0
;

  if (HasAlternativeForm) 
os << "#"0
;

  if (HasLeadingZeroes)   
os << "0"1
;

  // Minimum field width

  FieldWidth.toString(os);

  // Precision

  Precision.toString(os);

  // Vector modifier

  if (!VectorNumElts.isInvalid())

    os << 'v' << VectorNumElts.getConstantAmount();

  // Length modifier

  os << LM.toString();

  // Conversion specifier

  os << CS.toString();

}

bool PrintfSpecifier::hasValidPlusPrefix() const {

  if (!HasPlusPrefix)

    return true;

  // The plus prefix only makes sense for signed conversions

  switch (CS.getKind()) {

  case ConversionSpecifier::dArg:

  case ConversionSpecifier::DArg:

  case ConversionSpecifier::iArg:

  case ConversionSpecifier::fArg:

  case ConversionSpecifier::FArg:

  case ConversionSpecifier::eArg:

  case ConversionSpecifier::EArg:

  case ConversionSpecifier::gArg:

  case ConversionSpecifier::GArg:

  case ConversionSpecifier::aArg:

  case ConversionSpecifier::AArg:

  case ConversionSpecifier::FreeBSDrArg:

  case ConversionSpecifier::FreeBSDyArg:

    return true;

  default:

    return false;

  }

}

bool PrintfSpecifier::hasValidAlternativeForm() const {

  if (!HasAlternativeForm)

    return true;

  // Alternate form flag only valid with the oxXaAeEfFgG conversions

  switch (CS.getKind()) {

  case ConversionSpecifier::oArg:

  case ConversionSpecifier::OArg:

  case ConversionSpecifier::xArg:

  case ConversionSpecifier::XArg:

  case ConversionSpecifier::aArg:

  case ConversionSpecifier::AArg:

  case ConversionSpecifier::eArg:

  case ConversionSpecifier::EArg:

  case ConversionSpecifier::fArg:

  case ConversionSpecifier::FArg:

  case ConversionSpecifier::gArg:

  case ConversionSpecifier::GArg:

  case ConversionSpecifier::FreeBSDrArg:

  case ConversionSpecifier::FreeBSDyArg:

    return true;

  default:

    return false;

  }

}

bool PrintfSpecifier::hasValidLeadingZeros() const {

  if (!HasLeadingZeroes)

    return true;

  // Leading zeroes flag only valid with the diouxXaAeEfFgG conversions

  switch (CS.getKind()) {

  case ConversionSpecifier::dArg:

  case ConversionSpecifier::DArg:

  case ConversionSpecifier::iArg:

  case ConversionSpecifier::oArg:

  case ConversionSpecifier::OArg:

  case ConversionSpecifier::uArg:

  case ConversionSpecifier::UArg:

  case ConversionSpecifier::xArg:

  case ConversionSpecifier::XArg:

  case ConversionSpecifier::aArg:

  case ConversionSpecifier::AArg: