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-rw-r--r--clang/lib/Analysis/FormatString.cpp678
1 files changed, 678 insertions, 0 deletions
diff --git a/clang/lib/Analysis/FormatString.cpp b/clang/lib/Analysis/FormatString.cpp
new file mode 100644
index 0000000..ba45865
--- /dev/null
+++ b/clang/lib/Analysis/FormatString.cpp
@@ -0,0 +1,678 @@
+// FormatString.cpp - Common stuff for handling printf/scanf formats -*- C++ -*-
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Shared details for processing format strings of printf and scanf
+// (and friends).
+//
+//===----------------------------------------------------------------------===//
+
+#include "FormatStringParsing.h"
+#include "clang/Basic/LangOptions.h"
+
+using clang::analyze_format_string::ArgTypeResult;
+using clang::analyze_format_string::FormatStringHandler;
+using clang::analyze_format_string::FormatSpecifier;
+using clang::analyze_format_string::LengthModifier;
+using clang::analyze_format_string::OptionalAmount;
+using clang::analyze_format_string::PositionContext;
+using clang::analyze_format_string::ConversionSpecifier;
+using namespace clang;
+
+// Key function to FormatStringHandler.
+FormatStringHandler::~FormatStringHandler() {}
+
+//===----------------------------------------------------------------------===//
+// Functions for parsing format strings components in both printf and
+// scanf format strings.
+//===----------------------------------------------------------------------===//
+
+OptionalAmount
+clang::analyze_format_string::ParseAmount(const char *&Beg, const char *E) {
+ const char *I = Beg;
+ UpdateOnReturn <const char*> UpdateBeg(Beg, I);
+
+ unsigned accumulator = 0;
+ bool hasDigits = false;
+
+ for ( ; I != E; ++I) {
+ char c = *I;
+ if (c >= '0' && c <= '9') {
+ hasDigits = true;
+ accumulator = (accumulator * 10) + (c - '0');
+ continue;
+ }
+
+ if (hasDigits)
+ return OptionalAmount(OptionalAmount::Constant, accumulator, Beg, I - Beg,
+ false);
+
+ break;
+ }
+
+ return OptionalAmount();
+}
+
+OptionalAmount
+clang::analyze_format_string::ParseNonPositionAmount(const char *&Beg,
+ const char *E,
+ unsigned &argIndex) {
+ if (*Beg == '*') {
+ ++Beg;
+ return OptionalAmount(OptionalAmount::Arg, argIndex++, Beg, 0, false);
+ }
+
+ return ParseAmount(Beg, E);
+}
+
+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::ParseFieldWidth(FormatStringHandler &H,
+ FormatSpecifier &CS,
+ const char *Start,
+ const char *&Beg, const char *E,
+ unsigned *argIndex) {
+ // FIXME: Support negative field widths.
+ if (argIndex) {
+ CS.setFieldWidth(ParseNonPositionAmount(Beg, E, *argIndex));
+ }
+ else {
+ const OptionalAmount Amt =
+ ParsePositionAmount(H, Start, Beg, E,
+ analyze_format_string::FieldWidthPos);
+
+ if (Amt.isInvalid())
+ return true;
+ CS.setFieldWidth(Amt);
+ }
+ return false;
+}
+
+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;
+}
+
+bool
+clang::analyze_format_string::ParseLengthModifier(FormatSpecifier &FS,
+ const char *&I,
+ const char *E,
+ const LangOptions &LO,
+ bool IsScanf) {
+ LengthModifier::Kind lmKind = LengthModifier::None;
+ const char *lmPosition = I;
+ switch (*I) {
+ default:
+ return false;
+ case 'h':
+ ++I;
+ lmKind = (I != E && *I == 'h') ? (++I, LengthModifier::AsChar)
+ : LengthModifier::AsShort;
+ break;
+ case 'l':
+ ++I;
+ lmKind = (I != E && *I == 'l') ? (++I, LengthModifier::AsLongLong)
+ : LengthModifier::AsLong;
+ break;
+ case 'j': lmKind = LengthModifier::AsIntMax; ++I; break;
+ case 'z': lmKind = LengthModifier::AsSizeT; ++I; break;
+ case 't': lmKind = LengthModifier::AsPtrDiff; ++I; break;
+ case 'L': lmKind = LengthModifier::AsLongDouble; ++I; break;
+ case 'q': lmKind = LengthModifier::AsQuad; ++I; break;
+ case 'a':
+ if (IsScanf && !LO.C99 && !LO.CPlusPlus0x) {
+ // For scanf in C90, look at the next character to see if this should
+ // be parsed as the GNU extension 'a' length modifier. If not, this
+ // will be parsed as a conversion specifier.
+ ++I;
+ if (I != E && (*I == 's' || *I == 'S' || *I == '[')) {
+ lmKind = LengthModifier::AsAllocate;
+ break;
+ }
+ --I;
+ }
+ return false;
+ case 'm':
+ if (IsScanf) {
+ lmKind = LengthModifier::AsMAllocate;
+ ++I;
+ break;
+ }
+ return false;
+ }
+ LengthModifier lm(lmPosition, lmKind);
+ FS.setLengthModifier(lm);
+ return true;
+}
+
+//===----------------------------------------------------------------------===//
+// Methods on ArgTypeResult.
+//===----------------------------------------------------------------------===//
+
+bool ArgTypeResult::matchesType(ASTContext &C, QualType argTy) const {
+ switch (K) {
+ case InvalidTy:
+ llvm_unreachable("ArgTypeResult must be valid");
+
+ case UnknownTy:
+ return true;
+
+ case AnyCharTy: {
+ if (const BuiltinType *BT = argTy->getAs<BuiltinType>())
+ switch (BT->getKind()) {
+ default:
+ break;
+ case BuiltinType::Char_S:
+ case BuiltinType::SChar:
+ case BuiltinType::UChar:
+ case BuiltinType::Char_U:
+ return true;
+ }
+ return false;
+ }
+
+ case SpecificTy: {
+ argTy = C.getCanonicalType(argTy).getUnqualifiedType();
+ if (T == argTy)
+ return true;
+ // Check for "compatible types".
+ if (const BuiltinType *BT = argTy->getAs<BuiltinType>())
+ switch (BT->getKind()) {
+ default:
+ break;
+ case BuiltinType::Char_S:
+ case BuiltinType::SChar:
+ return T == C.UnsignedCharTy;
+ case BuiltinType::Char_U:
+ case BuiltinType::UChar:
+ return T == C.SignedCharTy;
+ case BuiltinType::Short:
+ return T == C.UnsignedShortTy;
+ case BuiltinType::UShort:
+ return T == C.ShortTy;
+ case BuiltinType::Int:
+ return T == C.UnsignedIntTy;
+ case BuiltinType::UInt:
+ return T == C.IntTy;
+ case BuiltinType::Long:
+ return T == C.UnsignedLongTy;
+ case BuiltinType::ULong:
+ return T == C.LongTy;
+ case BuiltinType::LongLong:
+ return T == C.UnsignedLongLongTy;
+ case BuiltinType::ULongLong:
+ return T == C.LongLongTy;
+ }
+ return false;
+ }
+
+ case CStrTy: {
+ const PointerType *PT = argTy->getAs<PointerType>();
+ if (!PT)
+ return false;
+ QualType pointeeTy = PT->getPointeeType();
+ if (const BuiltinType *BT = pointeeTy->getAs<BuiltinType>())
+ switch (BT->getKind()) {
+ case BuiltinType::Void:
+ case BuiltinType::Char_U:
+ case BuiltinType::UChar:
+ case BuiltinType::Char_S:
+ case BuiltinType::SChar:
+ return true;
+ default:
+ break;
+ }
+
+ return false;
+ }
+
+ case WCStrTy: {
+ const PointerType *PT = argTy->getAs<PointerType>();
+ if (!PT)
+ return false;
+ QualType pointeeTy =
+ C.getCanonicalType(PT->getPointeeType()).getUnqualifiedType();
+ return pointeeTy == C.getWCharType();
+ }
+
+ case WIntTy: {
+ // Instead of doing a lookup for the definition of 'wint_t' (which
+ // is defined by the system headers) instead see if wchar_t and
+ // the argument type promote to the same type.
+ QualType PromoWChar =
+ C.getWCharType()->isPromotableIntegerType()
+ ? C.getPromotedIntegerType(C.getWCharType()) : C.getWCharType();
+ QualType PromoArg =
+ argTy->isPromotableIntegerType()
+ ? C.getPromotedIntegerType(argTy) : argTy;
+
+ PromoWChar = C.getCanonicalType(PromoWChar).getUnqualifiedType();
+ PromoArg = C.getCanonicalType(PromoArg).getUnqualifiedType();
+
+ return PromoWChar == PromoArg;
+ }
+
+ case CPointerTy:
+ return argTy->isPointerType() || argTy->isObjCObjectPointerType() ||
+ argTy->isBlockPointerType() || argTy->isNullPtrType();
+
+ case ObjCPointerTy: {
+ if (argTy->getAs<ObjCObjectPointerType>() ||
+ argTy->getAs<BlockPointerType>())
+ return true;
+
+ // Handle implicit toll-free bridging.
+ if (const PointerType *PT = argTy->getAs<PointerType>()) {
+ // Things such as CFTypeRef are really just opaque pointers
+ // to C structs representing CF types that can often be bridged
+ // to Objective-C objects. Since the compiler doesn't know which
+ // structs can be toll-free bridged, we just accept them all.
+ QualType pointee = PT->getPointeeType();
+ if (pointee->getAsStructureType() || pointee->isVoidType())
+ return true;
+ }
+ return false;
+ }
+ }
+
+ llvm_unreachable("Invalid ArgTypeResult Kind!");
+}
+
+QualType ArgTypeResult::getRepresentativeType(ASTContext &C) const {
+ switch (K) {
+ case InvalidTy:
+ llvm_unreachable("No representative type for Invalid ArgTypeResult");
+ case UnknownTy:
+ return QualType();
+ case AnyCharTy:
+ return C.CharTy;
+ case SpecificTy:
+ return T;
+ case CStrTy:
+ return C.getPointerType(C.CharTy);
+ case WCStrTy:
+ return C.getPointerType(C.getWCharType());
+ case ObjCPointerTy:
+ return C.ObjCBuiltinIdTy;
+ case CPointerTy:
+ return C.VoidPtrTy;
+ case WIntTy: {
+ QualType WC = C.getWCharType();
+ return WC->isPromotableIntegerType() ? C.getPromotedIntegerType(WC) : WC;
+ }
+ }
+
+ llvm_unreachable("Invalid ArgTypeResult Kind!");
+}
+
+std::string ArgTypeResult::getRepresentativeTypeName(ASTContext &C) const {
+ std::string S = getRepresentativeType(C).getAsString();
+ if (Name && S != Name)
+ return std::string("'") + Name + "' (aka '" + S + "')";
+ return std::string("'") + S + "'";
+}
+
+
+//===----------------------------------------------------------------------===//
+// Methods on OptionalAmount.
+//===----------------------------------------------------------------------===//
+
+ArgTypeResult
+analyze_format_string::OptionalAmount::getArgType(ASTContext &Ctx) const {
+ return Ctx.IntTy;
+}
+
+//===----------------------------------------------------------------------===//
+// Methods on LengthModifier.
+//===----------------------------------------------------------------------===//
+
+const char *
+analyze_format_string::LengthModifier::toString() const {
+ switch (kind) {
+ case AsChar:
+ return "hh";
+ case AsShort:
+ return "h";
+ case AsLong: // or AsWideChar
+ return "l";
+ case AsLongLong:
+ return "ll";
+ case AsQuad:
+ return "q";
+ case AsIntMax:
+ return "j";
+ case AsSizeT:
+ return "z";
+ case AsPtrDiff:
+ return "t";
+ case AsLongDouble:
+ return "L";
+ case AsAllocate:
+ return "a";
+ case AsMAllocate:
+ return "m";
+ case None:
+ return "";
+ }
+ return NULL;
+}
+
+//===----------------------------------------------------------------------===//
+// Methods on ConversionSpecifier.
+//===----------------------------------------------------------------------===//
+
+const char *ConversionSpecifier::toString() const {
+ switch (kind) {
+ case dArg: return "d";
+ case iArg: return "i";
+ case oArg: return "o";
+ case uArg: return "u";
+ case xArg: return "x";
+ case XArg: return "X";
+ case fArg: return "f";
+ case FArg: return "F";
+ case eArg: return "e";
+ case EArg: return "E";
+ case gArg: return "g";
+ case GArg: return "G";
+ case aArg: return "a";
+ case AArg: return "A";
+ case cArg: return "c";
+ case sArg: return "s";
+ case pArg: return "p";
+ case nArg: return "n";
+ case PercentArg: return "%";
+ case ScanListArg: return "[";
+ case InvalidSpecifier: return NULL;
+
+ // MacOS X unicode extensions.
+ case CArg: return "C";
+ case SArg: return "S";
+
+ // Objective-C specific specifiers.
+ case ObjCObjArg: return "@";
+
+ // GlibC specific specifiers.
+ case PrintErrno: return "m";
+ }
+ return NULL;
+}
+
+//===----------------------------------------------------------------------===//
+// Methods on OptionalAmount.
+//===----------------------------------------------------------------------===//
+
+void OptionalAmount::toString(raw_ostream &os) const {
+ switch (hs) {
+ case Invalid:
+ case NotSpecified:
+ return;
+ case Arg:
+ if (UsesDotPrefix)
+ os << ".";
+ if (usesPositionalArg())
+ os << "*" << getPositionalArgIndex() << "$";
+ else
+ os << "*";
+ break;
+ case Constant:
+ if (UsesDotPrefix)
+ os << ".";
+ os << amt;
+ break;
+ }
+}
+
+bool FormatSpecifier::hasValidLengthModifier() const {
+ switch (LM.getKind()) {
+ case LengthModifier::None:
+ return true;
+
+ // Handle most integer flags
+ case LengthModifier::AsChar:
+ case LengthModifier::AsShort:
+ case LengthModifier::AsLongLong:
+ case LengthModifier::AsQuad:
+ case LengthModifier::AsIntMax:
+ case LengthModifier::AsSizeT:
+ case LengthModifier::AsPtrDiff:
+ switch (CS.getKind()) {
+ case ConversionSpecifier::dArg:
+ case ConversionSpecifier::iArg:
+ case ConversionSpecifier::oArg:
+ case ConversionSpecifier::uArg:
+ case ConversionSpecifier::xArg:
+ case ConversionSpecifier::XArg:
+ case ConversionSpecifier::nArg:
+ return true;
+ default:
+ return false;
+ }
+
+ // Handle 'l' flag
+ case LengthModifier::AsLong:
+ 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::fArg:
+ case ConversionSpecifier::FArg:
+ case ConversionSpecifier::eArg:
+ case ConversionSpecifier::EArg:
+ case ConversionSpecifier::gArg:
+ case ConversionSpecifier::GArg:
+ case ConversionSpecifier::nArg:
+ case ConversionSpecifier::cArg:
+ case ConversionSpecifier::sArg:
+ case ConversionSpecifier::ScanListArg:
+ return true;
+ default:
+ return false;
+ }
+
+ case LengthModifier::AsLongDouble:
+ switch (CS.getKind()) {
+ case ConversionSpecifier::aArg:
+ case ConversionSpecifier::AArg:
+ case ConversionSpecifier::fArg:
+ case ConversionSpecifier::FArg:
+ case ConversionSpecifier::eArg:
+ case ConversionSpecifier::EArg:
+ case ConversionSpecifier::gArg:
+ case ConversionSpecifier::GArg:
+ return true;
+ // GNU extension.
+ case ConversionSpecifier::dArg:
+ case ConversionSpecifier::iArg:
+ case ConversionSpecifier::oArg:
+ case ConversionSpecifier::uArg:
+ case ConversionSpecifier::xArg:
+ case ConversionSpecifier::XArg:
+ return true;
+ default:
+ return false;
+ }
+
+ case LengthModifier::AsAllocate:
+ switch (CS.getKind()) {
+ case ConversionSpecifier::sArg:
+ case ConversionSpecifier::SArg:
+ case ConversionSpecifier::ScanListArg:
+ return true;
+ default:
+ return false;
+ }
+
+ case LengthModifier::AsMAllocate:
+ switch (CS.getKind()) {
+ case ConversionSpecifier::cArg:
+ case ConversionSpecifier::CArg:
+ case ConversionSpecifier::sArg:
+ case ConversionSpecifier::SArg:
+ case ConversionSpecifier::ScanListArg:
+ return true;
+ default:
+ return false;
+ }
+ }
+ llvm_unreachable("Invalid LengthModifier Kind!");
+}
+
+bool FormatSpecifier::hasStandardLengthModifier() const {
+ switch (LM.getKind()) {
+ case LengthModifier::None:
+ case LengthModifier::AsChar:
+ case LengthModifier::AsShort:
+ case LengthModifier::AsLong:
+ case LengthModifier::AsLongLong:
+ case LengthModifier::AsIntMax:
+ case LengthModifier::AsSizeT:
+ case LengthModifier::AsPtrDiff:
+ case LengthModifier::AsLongDouble:
+ return true;
+ case LengthModifier::AsAllocate:
+ case LengthModifier::AsMAllocate:
+ case LengthModifier::AsQuad:
+ return false;
+ }
+ llvm_unreachable("Invalid LengthModifier Kind!");
+}
+
+bool FormatSpecifier::hasStandardConversionSpecifier(const LangOptions &LangOpt) const {
+ switch (CS.getKind()) {
+ case ConversionSpecifier::cArg:
+ case ConversionSpecifier::dArg:
+ case ConversionSpecifier::iArg:
+ case ConversionSpecifier::oArg:
+ case ConversionSpecifier::uArg:
+ case ConversionSpecifier::xArg:
+ case ConversionSpecifier::XArg:
+ 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::sArg:
+ case ConversionSpecifier::pArg:
+ case ConversionSpecifier::nArg:
+ case ConversionSpecifier::ObjCObjArg:
+ case ConversionSpecifier::ScanListArg:
+ case ConversionSpecifier::PercentArg:
+ return true;
+ case ConversionSpecifier::CArg:
+ case ConversionSpecifier::SArg:
+ return LangOpt.ObjC1 || LangOpt.ObjC2;
+ case ConversionSpecifier::InvalidSpecifier:
+ case ConversionSpecifier::PrintErrno:
+ return false;
+ }
+ llvm_unreachable("Invalid ConversionSpecifier Kind!");
+}
+
+bool FormatSpecifier::hasStandardLengthConversionCombination() const {
+ if (LM.getKind() == LengthModifier::AsLongDouble) {
+ switch(CS.getKind()) {
+ case ConversionSpecifier::dArg:
+ case ConversionSpecifier::iArg:
+ case ConversionSpecifier::oArg:
+ case ConversionSpecifier::uArg:
+ case ConversionSpecifier::xArg:
+ case ConversionSpecifier::XArg:
+ return false;
+ default:
+ return true;
+ }
+ }
+ return true;
+}
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