C++ FormatStringHandler类代码示例

OptionalAmount
clang::analyze_format_string::ParsePositionAmount(FormatStringHandler &H,
                                                  const char *Start,
                                                  const char *&Beg,
                                                  const char *E,
                                                  PositionContext p) {
  if (*Beg == '*') {
    const char *I = Beg + 1;
    const OptionalAmount &Amt = ParseAmount(I, E);

    if (Amt.getHowSpecified() == OptionalAmount::NotSpecified) {
      H.HandleInvalidPosition(Beg, I - Beg, p);
      return OptionalAmount(false);
    }

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

    assert(Amt.getHowSpecified() == OptionalAmount::Constant);

    if (*I == '$') {
      // Handle positional arguments

      // Special case: '*0$', since this is an easy mistake.
      if (Amt.getConstantAmount() == 0) {
        H.HandleZeroPosition(Beg, I - Beg + 1);
        return OptionalAmount(false);
      }

      const char *Tmp = Beg;
      Beg = ++I;

      return OptionalAmount(OptionalAmount::Arg, Amt.getConstantAmount() - 1,
                            Tmp, 0, true);
    }

    H.HandleInvalidPosition(Beg, I - Beg, p);
    return OptionalAmount(false);
  }

  return ParseAmount(Beg, E);
}

bool
clang::analyze_format_string::ParseArgPosition(FormatStringHandler &H,
                                               FormatSpecifier &FS,
                                               const char *Start,
                                               const char *&Beg,
                                               const char *E) {
  const char *I = Beg;

  const OptionalAmount &Amt = ParseAmount(I, E);

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

  if (Amt.getHowSpecified() == OptionalAmount::Constant && *(I++) == '$') {
    // Warn that positional arguments are non-standard.
    H.HandlePosition(Start, I - Start);

    // Special case: '%0$', since this is an easy mistake.
    if (Amt.getConstantAmount() == 0) {
      H.HandleZeroPosition(Start, I - Start);
      return true;
    }

    FS.setArgIndex(Amt.getConstantAmount() - 1);
    FS.setUsesPositionalArg();
    // Update the caller's pointer if we decided to consume
    // these characters.
    Beg = I;
    return false;
  }

  return false;
}

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;
    }
//.........这里部分代码省略.........

// FIXME: Much of this is copy-paste from ParsePrintfSpecifier.
// We can possibly refactor.
static ScanfSpecifierResult ParseScanfSpecifier(FormatStringHandler &H,
                                                const char *&Beg,
                                                const char *E,
                                                unsigned &argIndex,
                                                const LangOptions &LO) {
  
  using namespace clang::analyze_scanf;
  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;
  }
  
  ScanfSpecifier 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 '*' flag if it is present.
  if (*I == '*') {
    FS.setSuppressAssignment(I);
    if (++I == E) {
      H.HandleIncompleteSpecifier(Start, E - Start);
      return true;
    }
  }
  
  // Look for the field width (if any).  Unlike printf, this is either
  // a fixed integer or isn't present.
  const OptionalAmount &Amt = clang::analyze_format_string::ParseAmount(I, E);
  if (Amt.getHowSpecified() != OptionalAmount::NotSpecified) {
    assert(Amt.getHowSpecified() == OptionalAmount::Constant);
    FS.setFieldWidth(Amt);

    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, /*scanf=*/true) && I == E) {
      // No more characters left?
    H.HandleIncompleteSpecifier(Start, E - Start);
    return true;
  }
  
  // Detect spurious null characters, which are likely errors.
  if (*I == '\0') {
    H.HandleNullChar(I);
    return true;
  }
  
  // Finally, look for the conversion specifier.
  const char *conversionPosition = I++;
  ScanfConversionSpecifier::Kind k = ScanfConversionSpecifier::InvalidSpecifier;
  switch (*conversionPosition) {
    default:
      break;
    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 'd': k = ConversionSpecifier::dArg; break;
    case 'e': k = ConversionSpecifier::eArg; break;
    case 'f': k = ConversionSpecifier::fArg; break;
    case 'g': k = ConversionSpecifier::gArg; break;
//.........这里部分代码省略.........

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;
//.........这里部分代码省略.........

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;
//.........这里部分代码省略.........