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Diffstat (limited to 'contrib/llvm/tools/clang/lib/Analysis/PrintfFormatString.cpp')
| -rw-r--r-- | contrib/llvm/tools/clang/lib/Analysis/PrintfFormatString.cpp | 679 |
1 files changed, 679 insertions, 0 deletions
diff --git a/contrib/llvm/tools/clang/lib/Analysis/PrintfFormatString.cpp b/contrib/llvm/tools/clang/lib/Analysis/PrintfFormatString.cpp new file mode 100644 index 0000000..4b2a19e --- /dev/null +++ b/contrib/llvm/tools/clang/lib/Analysis/PrintfFormatString.cpp @@ -0,0 +1,679 @@ +//== PrintfFormatString.cpp - Analysis of printf format strings --*- C++ -*-==// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// Handling of format string in printf and friends. The structure of format +// strings for fprintf() are described in C99 7.19.6.1. +// +//===----------------------------------------------------------------------===// + +#include "clang/Analysis/Analyses/FormatString.h" +#include "FormatStringParsing.h" + +using clang::analyze_format_string::ArgTypeResult; +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 PrintfSpecifierResult ParsePrintfSpecifier(FormatStringHandler &H, + const char *&Beg, + const char *E, + unsigned &argIndex, + const LangOptions &LO) { + + 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; + // FreeBSD format extensions + case 'b': if (LO.FormatExtensions) k = ConversionSpecifier::bArg; break; /* check for int and then char * */ + case 'r': if (LO.FormatExtensions) k = ConversionSpecifier::rArg; break; + case 'y': if (LO.FormatExtensions) k = ConversionSpecifier::iArg; break; + case 'D': if (LO.FormatExtensions) k = ConversionSpecifier::DArg; break; /* check for u_char * pointer and a char * string */ + } + PrintfConversionSpecifier CS(conversionPosition, k); + FS.setConversionSpecifier(CS); + if (CS.consumesDataArgument() && !FS.usesPositionalArg()) + FS.setArgIndex(argIndex++); + // FreeBSD extension + if (k == ConversionSpecifier::bArg || k == ConversionSpecifier::DArg) + argIndex++; + + if (k == ConversionSpecifier::InvalidSpecifier) { + // Assume the conversion takes one argument. + return !H.HandleInvalidPrintfConversionSpecifier(FS, Start, I - Start); + } + return PrintfSpecifierResult(Start, FS); +} + +bool clang::analyze_format_string::ParsePrintfString(FormatStringHandler &H, + const char *I, + const char *E, + const LangOptions &LO) { + + 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); + // 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; +} + +//===----------------------------------------------------------------------===// +// Methods on PrintfSpecifier. +//===----------------------------------------------------------------------===// + +ArgTypeResult PrintfSpecifier::getArgType(ASTContext &Ctx, + bool IsObjCLiteral) const { + const PrintfConversionSpecifier &CS = getConversionSpecifier(); + + if (!CS.consumesDataArgument()) + return ArgTypeResult::Invalid(); + + if (CS.getKind() == ConversionSpecifier::cArg) + switch (LM.getKind()) { + case LengthModifier::None: return Ctx.IntTy; + case LengthModifier::AsLong: + return ArgTypeResult(ArgTypeResult::WIntTy, "wint_t"); + default: + return ArgTypeResult::Invalid(); + } + + if (CS.isIntArg()) + switch (LM.getKind()) { + case LengthModifier::AsLongDouble: + // GNU extension. + return Ctx.LongLongTy; + case LengthModifier::None: return Ctx.IntTy; + case LengthModifier::AsChar: return ArgTypeResult::AnyCharTy; + case LengthModifier::AsShort: return Ctx.ShortTy; + case LengthModifier::AsLong: return Ctx.LongTy; + case LengthModifier::AsLongLong: + case LengthModifier::AsQuad: + return Ctx.LongLongTy; + case LengthModifier::AsIntMax: + return ArgTypeResult(Ctx.getIntMaxType(), "intmax_t"); + case LengthModifier::AsSizeT: + // FIXME: How to get the corresponding signed version of size_t? + return ArgTypeResult(); + case LengthModifier::AsPtrDiff: + return ArgTypeResult(Ctx.getPointerDiffType(), "ptrdiff_t"); + case LengthModifier::AsAllocate: + case LengthModifier::AsMAllocate: + return ArgTypeResult::Invalid(); + } + + if (CS.isUIntArg()) + switch (LM.getKind()) { + case LengthModifier::AsLongDouble: + // GNU extension. + return Ctx.UnsignedLongLongTy; + case LengthModifier::None: return Ctx.UnsignedIntTy; + 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::AsIntMax: + return ArgTypeResult(Ctx.getUIntMaxType(), "uintmax_t"); + case LengthModifier::AsSizeT: + return ArgTypeResult(Ctx.getSizeType(), "size_t"); + case LengthModifier::AsPtrDiff: + // FIXME: How to get the corresponding unsigned + // version of ptrdiff_t? + return ArgTypeResult(); + case LengthModifier::AsAllocate: + case LengthModifier::AsMAllocate: + return ArgTypeResult::Invalid(); + } + + if (CS.isDoubleArg()) { + if (LM.getKind() == LengthModifier::AsLongDouble) + return Ctx.LongDoubleTy; + return Ctx.DoubleTy; + } + + switch (CS.getKind()) { + case ConversionSpecifier::sArg: + if (LM.getKind() == LengthModifier::AsWideChar) { + if (IsObjCLiteral) + return Ctx.getPointerType(Ctx.UnsignedShortTy.withConst()); + return ArgTypeResult(ArgTypeResult::WCStrTy, "wchar_t *"); + } + return ArgTypeResult::CStrTy; + case ConversionSpecifier::SArg: + if (IsObjCLiteral) + return Ctx.getPointerType(Ctx.UnsignedShortTy.withConst()); + return ArgTypeResult(ArgTypeResult::WCStrTy, "wchar_t *"); + case ConversionSpecifier::CArg: + if (IsObjCLiteral) + return Ctx.UnsignedShortTy; + return ArgTypeResult(Ctx.WCharTy, "wchar_t"); + case ConversionSpecifier::pArg: + return ArgTypeResult::CPointerTy; + case ConversionSpecifier::ObjCObjArg: + return ArgTypeResult::ObjCPointerTy; + default: + break; + } + + // FIXME: Handle other cases. + return ArgTypeResult(); +} + +bool PrintfSpecifier::fixType(QualType QT, const LangOptions &LangOpt, + ASTContext &Ctx, bool IsObjCLiteral) { + // Handle strings first (char *, wchar_t *) + if (QT->isPointerType() && (QT->getPointeeType()->isAnyCharacterType())) { + 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; + } + + // We can only work with builtin types. + const BuiltinType *BT = QT->getAs<BuiltinType>(); + if (!BT) + return false; + + // Set length modifier + switch (BT->getKind()) { + case BuiltinType::Bool: + case BuiltinType::WChar_U: + case BuiltinType::WChar_S: + case BuiltinType::Char16: + case BuiltinType::Char32: + case BuiltinType::UInt128: + case BuiltinType::Int128: + case BuiltinType::Half: + // Various types which are non-trivial to correct. + return false; + +#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: + case BuiltinType::Double: + LM.setKind(LengthModifier::None); + 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) && (LangOpt.C99 || LangOpt.CPlusPlus0x)) { + const IdentifierInfo *Identifier = QT.getBaseTypeIdentifier(); + if (Identifier->getName() == "size_t") { + LM.setKind(LengthModifier::AsSizeT); + } else if (Identifier->getName() == "ssize_t") { + // Not C99, but common in Unix. + LM.setKind(LengthModifier::AsSizeT); + } else if (Identifier->getName() == "intmax_t") { + LM.setKind(LengthModifier::AsIntMax); + } else if (Identifier->getName() == "uintmax_t") { + LM.setKind(LengthModifier::AsIntMax); + } else if (Identifier->getName() == "ptrdiff_t") { + LM.setKind(LengthModifier::AsPtrDiff); + } + } + + // If fixing the length modifier was enough, we are done. + const analyze_printf::ArgTypeResult &ATR = getArgType(Ctx, IsObjCLiteral); + if (hasValidLengthModifier() && ATR.isValid() && ATR.matchesType(Ctx, QT)) + 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->isAnyCharacterType()) { + 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 << "-"; + if (HasPlusPrefix) os << "+"; + if (HasSpacePrefix) os << " "; + if (HasAlternativeForm) os << "#"; + if (HasLeadingZeroes) os << "0"; + + // Minimum field width + FieldWidth.toString(os); + // Precision + Precision.toString(os); + // 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::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::rArg: + 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::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::rArg: + 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::iArg: + case ConversionSpecifier::oArg: + case ConversionSpecifier::uArg: + 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: + return true; + + default: + return false; + } +} + +bool PrintfSpecifier::hasValidSpacePrefix() const { + if (!HasSpacePrefix) + return true; + + // The space prefix only makes sense for signed conversions + switch (CS.getKind()) { + 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: + return true; + + default: + return false; + } +} + +bool PrintfSpecifier::hasValidLeftJustified() const { + if (!IsLeftJustified) + return true; + + // The left justified flag is valid for all conversions except n + switch (CS.getKind()) { + case ConversionSpecifier::nArg: + return false; + + default: + return true; + } +} + +bool PrintfSpecifier::hasValidThousandsGroupingPrefix() const { + if (!HasThousandsGrouping) + return true; + + switch (CS.getKind()) { + case ConversionSpecifier::dArg: + case ConversionSpecifier::iArg: + case ConversionSpecifier::uArg: + case ConversionSpecifier::fArg: + case ConversionSpecifier::FArg: + case ConversionSpecifier::gArg: + case ConversionSpecifier::GArg: + return true; + default: + return false; + } +} + +bool PrintfSpecifier::hasValidPrecision() const { + if (Precision.getHowSpecified() == OptionalAmount::NotSpecified) + return true; + + // Precision is only valid with the diouxXaAeEfFgGs conversions + switch (CS.getKind()) { + case ConversionSpecifier::dArg: + case ConversionSpecifier::iArg: + case ConversionSpecifier::oArg: + case ConversionSpecifier::uArg: + 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::sArg: + return true; + + default: + return false; + } +} +bool PrintfSpecifier::hasValidFieldWidth() const { + if (FieldWidth.getHowSpecified() == OptionalAmount::NotSpecified) + return true; + + // The field width is valid for all conversions except n + switch (CS.getKind()) { + case ConversionSpecifier::nArg: + return false; + + default: + return true; + } +} |
