Merge branch 'master' of ssh://bitbucket.org/czan/honours

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;
+}