Beispiel #1
0
// access 2D memory array at given index
Expr *ASTTranslate::accessMem2DAt(DeclRefExpr *LHS, Expr *idx_x, Expr *idx_y) {
  QualType QT = LHS->getType();
  QualType QT2 = QT->getPointeeType()->getAsArrayTypeUnsafe()->getElementType();

  // mark image as being used within the kernel
  Kernel->setUsed(LHS->getNameInfo().getAsString());

  Expr *result = new (Ctx) ArraySubscriptExpr(createImplicitCastExpr(Ctx, QT,
        CK_LValueToRValue, LHS, nullptr, VK_RValue), idx_y,
        QT->getPointeeType(), VK_LValue, OK_Ordinary, SourceLocation());

  result = new (Ctx) ArraySubscriptExpr(createImplicitCastExpr(Ctx,
        Ctx.getPointerType(QT2), CK_ArrayToPointerDecay, result, nullptr,
        VK_RValue), idx_x, QT2, VK_LValue, OK_Ordinary, SourceLocation());

  return result;
}
Beispiel #2
0
SVal StoreManager::evalDynamicCast(SVal Base, QualType DerivedType,
                                   bool &Failed) {
  Failed = false;

  loc::MemRegionVal *BaseRegVal = dyn_cast<loc::MemRegionVal>(&Base);
  if (!BaseRegVal)
    return UnknownVal();
  const MemRegion *BaseRegion = BaseRegVal->stripCasts(/*StripBases=*/false);

  // Assume the derived class is a pointer or a reference to a CXX record.
  DerivedType = DerivedType->getPointeeType();
  assert(!DerivedType.isNull());
  const CXXRecordDecl *DerivedDecl = DerivedType->getAsCXXRecordDecl();
  if (!DerivedDecl && !DerivedType->isVoidType())
    return UnknownVal();

  // Drill down the CXXBaseObject chains, which represent upcasts (casts from
  // derived to base).
  const MemRegion *SR = BaseRegion;
  while (const TypedRegion *TSR = dyn_cast_or_null<TypedRegion>(SR)) {
    QualType BaseType = TSR->getLocationType()->getPointeeType();
    assert(!BaseType.isNull());
    const CXXRecordDecl *SRDecl = BaseType->getAsCXXRecordDecl();
    if (!SRDecl)
      return UnknownVal();

    // If found the derived class, the cast succeeds.
    if (SRDecl == DerivedDecl)
      return loc::MemRegionVal(TSR);

    if (!DerivedType->isVoidType()) {
      // Static upcasts are marked as DerivedToBase casts by Sema, so this will
      // only happen when multiple or virtual inheritance is involved.
      CXXBasePaths Paths(/*FindAmbiguities=*/false, /*RecordPaths=*/true,
                         /*DetectVirtual=*/false);
      if (SRDecl->isDerivedFrom(DerivedDecl, Paths))
        return evalDerivedToBase(loc::MemRegionVal(TSR), Paths.front());
    }

    if (const CXXBaseObjectRegion *R = dyn_cast<CXXBaseObjectRegion>(TSR))
      // Drill down the chain to get the derived classes.
      SR = R->getSuperRegion();
    else {
      // We reached the bottom of the hierarchy.

      // If this is a cast to void*, return the region.
      if (DerivedType->isVoidType())
        return loc::MemRegionVal(TSR);

      // We did not find the derived class. We we must be casting the base to
      // derived, so the cast should fail.
      Failed = true;
      return UnknownVal();
    }
  }
  
  return UnknownVal();
}
Beispiel #3
0
/// \brief Returns true if a type is a pointer-to-const or reference-to-const
/// with no further indirection.
static bool isPointerToConst(QualType Ty) {
  QualType PointeeTy = Ty->getPointeeType();
  if (PointeeTy == QualType())
    return false;
  if (!PointeeTy.isConstQualified())
    return false;
  if (PointeeTy->isAnyPointerType())
    return false;
  return true;
}
Beispiel #4
0
/// \brief Figure out if an expression could be turned into a call.
///
/// Use this when trying to recover from an error where the programmer may have
/// written just the name of a function instead of actually calling it.
///
/// \param E - The expression to examine.
/// \param ZeroArgCallReturnTy - If the expression can be turned into a call
///  with no arguments, this parameter is set to the type returned by such a
///  call; otherwise, it is set to an empty QualType.
/// \param NonTemplateOverloads - If the expression is an overloaded function
///  name, this parameter is populated with the decls of the various overloads.
bool Sema::isExprCallable(const Expr &E, QualType &ZeroArgCallReturnTy,
                          UnresolvedSetImpl &NonTemplateOverloads) {
  ZeroArgCallReturnTy = QualType();
  NonTemplateOverloads.clear();
  if (const OverloadExpr *Overloads = dyn_cast<OverloadExpr>(&E)) {
    for (OverloadExpr::decls_iterator it = Overloads->decls_begin(),
         DeclsEnd = Overloads->decls_end(); it != DeclsEnd; ++it) {
      // Our overload set may include TemplateDecls, which we'll ignore for our
      // present purpose.
      if (const FunctionDecl *OverloadDecl = dyn_cast<FunctionDecl>(*it)) {
        NonTemplateOverloads.addDecl(*it);
        if (OverloadDecl->getMinRequiredArguments() == 0)
          ZeroArgCallReturnTy = OverloadDecl->getResultType();
      }
    }
    return true;
  }

  if (const DeclRefExpr *DeclRef = dyn_cast<DeclRefExpr>(&E)) {
    if (const FunctionDecl *Fun = dyn_cast<FunctionDecl>(DeclRef->getDecl())) {
      if (Fun->getMinRequiredArguments() == 0)
        ZeroArgCallReturnTy = Fun->getResultType();
      return true;
    }
  }

  // We don't have an expression that's convenient to get a FunctionDecl from,
  // but we can at least check if the type is "function of 0 arguments".
  QualType ExprTy = E.getType();
  const FunctionType *FunTy = NULL;
  QualType PointeeTy = ExprTy->getPointeeType();
  if (!PointeeTy.isNull())
    FunTy = PointeeTy->getAs<FunctionType>();
  if (!FunTy)
    FunTy = ExprTy->getAs<FunctionType>();
  if (!FunTy && ExprTy == Context.BoundMemberTy) {
    // Look for the bound-member type.  If it's still overloaded, give up,
    // although we probably should have fallen into the OverloadExpr case above
    // if we actually have an overloaded bound member.
    QualType BoundMemberTy = Expr::findBoundMemberType(&E);
    if (!BoundMemberTy.isNull())
      FunTy = BoundMemberTy->castAs<FunctionType>();
  }

  if (const FunctionProtoType *FPT =
      dyn_cast_or_null<FunctionProtoType>(FunTy)) {
    if (FPT->getNumArgs() == 0)
      ZeroArgCallReturnTy = FunTy->getResultType();
    return true;
  }
  return false;
}
Beispiel #5
0
PathDiagnosticPiece *
UndefOrNullArgVisitor::VisitNode(const ExplodedNode *N,
                                  const ExplodedNode *PrevN,
                                  BugReporterContext &BRC,
                                  BugReport &BR) {

  ProgramStateRef State = N->getState();
  ProgramPoint ProgLoc = N->getLocation();

  // We are only interested in visiting CallEnter nodes.
  Optional<CallEnter> CEnter = ProgLoc.getAs<CallEnter>();
  if (!CEnter)
    return 0;

  // Check if one of the arguments is the region the visitor is tracking.
  CallEventManager &CEMgr = BRC.getStateManager().getCallEventManager();
  CallEventRef<> Call = CEMgr.getCaller(CEnter->getCalleeContext(), State);
  unsigned Idx = 0;
  for (CallEvent::param_iterator I = Call->param_begin(),
                                 E = Call->param_end(); I != E; ++I, ++Idx) {
    const MemRegion *ArgReg = Call->getArgSVal(Idx).getAsRegion();

    // Are we tracking the argument or its subregion?
    if ( !ArgReg || (ArgReg != R && !R->isSubRegionOf(ArgReg->StripCasts())))
      continue;

    // Check the function parameter type.
    const ParmVarDecl *ParamDecl = *I;
    assert(ParamDecl && "Formal parameter has no decl?");
    QualType T = ParamDecl->getType();

    if (!(T->isAnyPointerType() || T->isReferenceType())) {
      // Function can only change the value passed in by address.
      continue;
    }
    
    // If it is a const pointer value, the function does not intend to
    // change the value.
    if (T->getPointeeType().isConstQualified())
      continue;

    // Mark the call site (LocationContext) as interesting if the value of the 
    // argument is undefined or '0'/'NULL'.
    SVal BoundVal = State->getSVal(R);
    if (BoundVal.isUndef() || BoundVal.isZeroConstant()) {
      BR.markInteresting(CEnter->getCalleeContext());
      return 0;
    }
  }
  return 0;
}
Beispiel #6
0
// Check if type is a "Field() *" pointer type, or alternatively a pointer to
// any type in "alt" if provided.
bool CheckAllocationsInFunctionVisitor::IsFieldPointer(
    const QualType& qtype, const char* alt)
{
    if (qtype->isPointerType())
    {
        auto name = qtype->getPointeeType()
            .getDesugaredType(_mainVisitor->getContext()).getAsString();
        return StartsWith(name, "class Memory::WriteBarrierPtr<")
            || StartsWith(name, "typename WriteBarrierFieldTypeTraits<")
            || (alt && strstr(alt, name.c_str()));
    }

    return false;
}
void edmChecker::checkASTDecl(const clang::CXXRecordDecl *RD, clang::ento::AnalysisManager& mgr,
                    clang::ento::BugReporter &BR) const {

	const clang::SourceManager &SM = BR.getSourceManager();
	clang::ento::PathDiagnosticLocation DLoc =clang::ento::PathDiagnosticLocation::createBegin( RD, SM );
	if (  !m_exception.reportClass( DLoc, BR ) ) return;
// Check the class methods (member methods).
	for (clang::CXXRecordDecl::method_iterator
		I = RD->method_begin(), E = RD->method_end(); I != E; ++I)  
	{      
		if ( !llvm::isa<clang::CXXMethodDecl>((*I)) ) continue;
		clang::CXXMethodDecl * MD = llvm::cast<clang::CXXMethodDecl>((*I));
			if ( MD->getNameAsString() == "beginRun" 
				|| MD->getNameAsString() == "endRun" 
				|| MD->getNameAsString() == "beginLuminosityBlock" 
				|| MD->getNameAsString() == "endLuminosityBlock" )
			{
//				llvm::errs()<<MD->getQualifiedNameAsString()<<"\n";	
				for (auto J=RD->bases_begin(), F=RD->bases_end();J != F; ++J)
					{  
					std::string name = J->getType()->castAs<RecordType>()->getDecl()->getQualifiedNameAsString();
//					llvm::errs()<<RD->getQualifiedNameAsString()<<"\n";	
//					llvm::errs() << "inherits from " <<name<<"\n";
					if (name=="edm::EDProducer" || name=="edm::EDFilter")
						{
						llvm::SmallString<100> buf;
						llvm::raw_svector_ostream os(buf);
						os << RD->getQualifiedNameAsString() << " inherits from edm::EDProducer or edm::EDFilter";
						os << "\n";
						llvm::errs()<<os.str();

						CXXMethodDecl::param_iterator I = MD->param_begin();
						ParmVarDecl * PVD = *(I);
						QualType PQT = PVD->getType();
						if ( PQT->isReferenceType() ) {
							QualType RQT = PQT->getPointeeType();
							if (RQT.isConstQualified()) continue;
						}
						clang::ento::PathDiagnosticLocation ELoc =clang::ento::PathDiagnosticLocation::createBegin( MD, SM );
						clang::SourceLocation SL = MD->getLocStart();
						BR.EmitBasicReport(MD, "Class Checker : inherits from edm::EDProducer or edm::EDFilter","optional",os.str(),ELoc,SL);
						}
					}
			}
	}
} //end of class
Beispiel #8
0
static RValue PerformReturnAdjustment(CodeGenFunction &CGF,
                                      QualType ResultType, RValue RV,
                                      const ThunkInfo &Thunk) {
  // Emit the return adjustment.
  bool NullCheckValue = !ResultType->isReferenceType();

  llvm::BasicBlock *AdjustNull = nullptr;
  llvm::BasicBlock *AdjustNotNull = nullptr;
  llvm::BasicBlock *AdjustEnd = nullptr;

  llvm::Value *ReturnValue = RV.getScalarVal();

  if (NullCheckValue) {
    AdjustNull = CGF.createBasicBlock("adjust.null");
    AdjustNotNull = CGF.createBasicBlock("adjust.notnull");
    AdjustEnd = CGF.createBasicBlock("adjust.end");

    llvm::Value *IsNull = CGF.Builder.CreateIsNull(ReturnValue);
    CGF.Builder.CreateCondBr(IsNull, AdjustNull, AdjustNotNull);
    CGF.EmitBlock(AdjustNotNull);
  }

  auto ClassDecl = ResultType->getPointeeType()->getAsCXXRecordDecl();
  auto ClassAlign = CGF.CGM.getClassPointerAlignment(ClassDecl);
  ReturnValue = CGF.CGM.getCXXABI().performReturnAdjustment(CGF,
                                            Address(ReturnValue, ClassAlign),
                                            Thunk.Return);

  if (NullCheckValue) {
    CGF.Builder.CreateBr(AdjustEnd);
    CGF.EmitBlock(AdjustNull);
    CGF.Builder.CreateBr(AdjustEnd);
    CGF.EmitBlock(AdjustEnd);

    llvm::PHINode *PHI = CGF.Builder.CreatePHI(ReturnValue->getType(), 2);
    PHI->addIncoming(ReturnValue, AdjustNotNull);
    PHI->addIncoming(llvm::Constant::getNullValue(ReturnValue->getType()),
                     AdjustNull);
    ReturnValue = PHI;
  }

  return RValue::get(ReturnValue);
}
Beispiel #9
0
static bool isCallback(QualType T) {
  // If a parameter is a block or a callback, assume it can modify pointer.
  if (T->isBlockPointerType() ||
      T->isFunctionPointerType() ||
      T->isObjCSelType())
    return true;

  // Check if a callback is passed inside a struct (for both, struct passed by
  // reference and by value). Dig just one level into the struct for now.

  if (T->isAnyPointerType() || T->isReferenceType())
    T = T->getPointeeType();

  if (const RecordType *RT = T->getAsStructureType()) {
    const RecordDecl *RD = RT->getDecl();
    for (const auto *I : RD->fields()) {
      QualType FieldT = I->getType();
      if (FieldT->isBlockPointerType() || FieldT->isFunctionPointerType())
        return true;
    }
  }
  return false;
}
Beispiel #10
0
Optional<SVal> GenericTaintChecker::getPointedToSVal(CheckerContext &C,
                                                     const Expr *Arg) {
  ProgramStateRef State = C.getState();
  SVal AddrVal = C.getSVal(Arg->IgnoreParens());
  if (AddrVal.isUnknownOrUndef())
    return None;

  Optional<Loc> AddrLoc = AddrVal.getAs<Loc>();
  if (!AddrLoc)
    return None;

  QualType ArgTy = Arg->getType().getCanonicalType();
  if (!ArgTy->isPointerType())
    return None;

  QualType ValTy = ArgTy->getPointeeType();

  // Do not dereference void pointers. Treat them as byte pointers instead.
  // FIXME: we might want to consider more than just the first byte.
  if (ValTy->isVoidType())
    ValTy = C.getASTContext().CharTy;

  return State->getSVal(*AddrLoc, ValTy);
}
Beispiel #11
0
SVal StoreManager::attemptDownCast(SVal Base, QualType TargetType,
                                   bool &Failed) {
  Failed = false;

  const MemRegion *MR = Base.getAsRegion();
  if (!MR)
    return UnknownVal();

  // Assume the derived class is a pointer or a reference to a CXX record.
  TargetType = TargetType->getPointeeType();
  assert(!TargetType.isNull());
  const CXXRecordDecl *TargetClass = TargetType->getAsCXXRecordDecl();
  if (!TargetClass && !TargetType->isVoidType())
    return UnknownVal();

  // Drill down the CXXBaseObject chains, which represent upcasts (casts from
  // derived to base).
  while (const CXXRecordDecl *MRClass = getCXXRecordType(MR)) {
    // If found the derived class, the cast succeeds.
    if (MRClass == TargetClass)
      return loc::MemRegionVal(MR);

    // We skip over incomplete types. They must be the result of an earlier
    // reinterpret_cast, as one can only dynamic_cast between types in the same
    // class hierarchy.
    if (!TargetType->isVoidType() && MRClass->hasDefinition()) {
      // Static upcasts are marked as DerivedToBase casts by Sema, so this will
      // only happen when multiple or virtual inheritance is involved.
      CXXBasePaths Paths(/*FindAmbiguities=*/false, /*RecordPaths=*/true,
                         /*DetectVirtual=*/false);
      if (MRClass->isDerivedFrom(TargetClass, Paths))
        return evalDerivedToBase(loc::MemRegionVal(MR), Paths.front());
    }

    if (const auto *BaseR = dyn_cast<CXXBaseObjectRegion>(MR)) {
      // Drill down the chain to get the derived classes.
      MR = BaseR->getSuperRegion();
      continue;
    }

    // If this is a cast to void*, return the region.
    if (TargetType->isVoidType())
      return loc::MemRegionVal(MR);

    // Strange use of reinterpret_cast can give us paths we don't reason
    // about well, by putting in ElementRegions where we'd expect
    // CXXBaseObjectRegions. If it's a valid reinterpret_cast (i.e. if the
    // derived class has a zero offset from the base class), then it's safe
    // to strip the cast; if it's invalid, -Wreinterpret-base-class should
    // catch it. In the interest of performance, the analyzer will silently
    // do the wrong thing in the invalid case (because offsets for subregions
    // will be wrong).
    const MemRegion *Uncasted = MR->StripCasts(/*IncludeBaseCasts=*/false);
    if (Uncasted == MR) {
      // We reached the bottom of the hierarchy and did not find the derived
      // class. We must be casting the base to derived, so the cast should
      // fail.
      break;
    }

    MR = Uncasted;
  }

  // If we're casting a symbolic base pointer to a derived class, use
  // CXXDerivedObjectRegion to represent the cast. If it's a pointer to an
  // unrelated type, it must be a weird reinterpret_cast and we have to
  // be fine with ElementRegion. TODO: Should we instead make
  // Derived{TargetClass, Element{SourceClass, SR}}?
  if (const auto *SR = dyn_cast<SymbolicRegion>(MR)) {
    QualType T = SR->getSymbol()->getType();
    const CXXRecordDecl *SourceClass = T->getPointeeCXXRecordDecl();
    if (TargetClass && SourceClass && TargetClass->isDerivedFrom(SourceClass))
      return loc::MemRegionVal(
          MRMgr.getCXXDerivedObjectRegion(TargetClass, SR));
    return loc::MemRegionVal(GetElementZeroRegion(SR, TargetType));
  }

  // We failed if the region we ended up with has perfect type info.
  Failed = isa<TypedValueRegion>(MR);
  return UnknownVal();
}
/// Checks whether the return types are covariant, according to
/// C++[class.virtual]p7.
///
/// Similar with clang::Sema::CheckOverridingFunctionReturnType.
/// \returns true if the return types of BaseMD and DerivedMD are covariant.
static bool checkOverridingFunctionReturnType(const ASTContext *Context,
                                              const CXXMethodDecl *BaseMD,
                                              const CXXMethodDecl *DerivedMD) {
  QualType BaseReturnTy = BaseMD->getType()
                              ->getAs<FunctionType>()
                              ->getReturnType()
                              .getCanonicalType();
  QualType DerivedReturnTy = DerivedMD->getType()
                                 ->getAs<FunctionType>()
                                 ->getReturnType()
                                 .getCanonicalType();

  if (DerivedReturnTy->isDependentType() || BaseReturnTy->isDependentType())
    return false;

  // Check if return types are identical.
  if (Context->hasSameType(DerivedReturnTy, BaseReturnTy))
    return true;

  /// Check if the return types are covariant.

  // Both types must be pointers or references to classes.
  if (!(BaseReturnTy->isPointerType() && DerivedReturnTy->isPointerType()) &&
      !(BaseReturnTy->isReferenceType() && DerivedReturnTy->isReferenceType()))
    return false;

  /// BTy is the class type in return type of BaseMD. For example,
  ///    B* Base::md()
  /// While BRD is the declaration of B.
  QualType DTy = DerivedReturnTy->getPointeeType().getCanonicalType();
  QualType BTy = BaseReturnTy->getPointeeType().getCanonicalType();

  const CXXRecordDecl *DRD = DTy->getAsCXXRecordDecl();
  const CXXRecordDecl *BRD = BTy->getAsCXXRecordDecl();
  if (DRD == nullptr || BRD == nullptr)
    return false;

  if (!DRD->hasDefinition() || !BRD->hasDefinition())
    return false;

  if (DRD == BRD)
    return true;

  if (!Context->hasSameUnqualifiedType(DTy, BTy)) {
    // Begin checking whether the conversion from D to B is valid.
    CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
                       /*DetectVirtual=*/false);

    // Check whether D is derived from B, and fill in a CXXBasePaths object.
    if (!DRD->isDerivedFrom(BRD, Paths))
      return false;

    // Check ambiguity.
    if (Paths.isAmbiguous(Context->getCanonicalType(BTy).getUnqualifiedType()))
      return false;

    // Check accessibility.
    // FIXME: We currently only support checking if B is accessible base class
    // of D, or D is the same class which DerivedMD is in.
    bool IsItself =
        DRD->getCanonicalDecl() == DerivedMD->getParent()->getCanonicalDecl();
    bool HasPublicAccess = false;
    for (const auto &Path : Paths) {
      if (Path.Access == AS_public)
        HasPublicAccess = true;
    }
    if (!HasPublicAccess && !IsItself)
      return false;
    // End checking conversion from D to B.
  }

  // Both pointers or references should have the same cv-qualification.
  if (DerivedReturnTy.getLocalCVRQualifiers() !=
      BaseReturnTy.getLocalCVRQualifiers())
    return false;

  // The class type D should have the same cv-qualification as or less
  // cv-qualification than the class type B.
  if (DTy.isMoreQualifiedThan(BTy))
    return false;

  return true;
}
Beispiel #13
0
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())) {
    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();

  // 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:
  case BuiltinType::Float128:
    // 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"
#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.CPlusPlus11))
    namedTypeToLengthModifier(QT, LM);

  // If fixing the length modifier was enough, we might be done.
  if (hasValidLengthModifier(Ctx.getTargetInfo())) {
    // 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() && !HasPlusPrefix)
        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))
      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()) {
    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;
}
Beispiel #14
0
bool ScanfSpecifier::fixType(QualType QT, const LangOptions &LangOpt)
{
  if (!QT->isPointerType())
    return false;

  QualType PT = QT->getPointeeType();
  const BuiltinType *BT = PT->getAs<BuiltinType>();
  if (!BT)
    return false;

  // Pointer to a character.
  if (PT->isAnyCharacterType()) {
    CS.setKind(ConversionSpecifier::sArg);
    if (PT->isWideCharType())
      LM.setKind(LengthModifier::AsWideChar);
    else
      LM.setKind(LengthModifier::None);
    return true;
  }

  // Figure out the length modifier.
  switch (BT->getKind()) {
    // no modifier
    case BuiltinType::UInt:
    case BuiltinType::Int:
    case BuiltinType::Float:
      LM.setKind(LengthModifier::None);
      break;

    // hh
    case BuiltinType::Char_U:
    case BuiltinType::UChar:
    case BuiltinType::Char_S:
    case BuiltinType::SChar:
      LM.setKind(LengthModifier::AsChar);
      break;

    // h
    case BuiltinType::Short:
    case BuiltinType::UShort:
      LM.setKind(LengthModifier::AsShort);
      break;

    // l
    case BuiltinType::Long:
    case BuiltinType::ULong:
    case BuiltinType::Double:
      LM.setKind(LengthModifier::AsLong);
      break;

    // ll
    case BuiltinType::LongLong:
    case BuiltinType::ULongLong:
      LM.setKind(LengthModifier::AsLongLong);
      break;

    // L
    case BuiltinType::LongDouble:
      LM.setKind(LengthModifier::AsLongDouble);
      break;

    // Don't know.
    default:
      return false;
  }

  // Handle size_t, ptrdiff_t, etc. that have dedicated length modifiers in C99.
  if (isa<TypedefType>(PT) && (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);
    }
  }

  // Figure out the conversion specifier.
  if (PT->isRealFloatingType())
    CS.setKind(ConversionSpecifier::fArg);
  else if (PT->isSignedIntegerType())
    CS.setKind(ConversionSpecifier::dArg);
  else if (PT->isUnsignedIntegerType()) {
    // Preserve the original formatting, e.g. 'X', 'o'.
    if (!CS.isUIntArg()) {
      CS.setKind(ConversionSpecifier::uArg);
    }
  } else
    llvm_unreachable("Unexpected type");

  return true;
}
Beispiel #15
0
RValue CodeGenFunction::EmitAtomicExpr(AtomicExpr *E, llvm::Value *Dest) {
  QualType AtomicTy = E->getPtr()->getType()->getPointeeType();
  QualType MemTy = AtomicTy;
  if (const AtomicType *AT = AtomicTy->getAs<AtomicType>())
    MemTy = AT->getValueType();
  CharUnits sizeChars = getContext().getTypeSizeInChars(AtomicTy);
  uint64_t Size = sizeChars.getQuantity();
  CharUnits alignChars = getContext().getTypeAlignInChars(AtomicTy);
  unsigned Align = alignChars.getQuantity();
  unsigned MaxInlineWidthInBits =
    getTarget().getMaxAtomicInlineWidth();
  bool UseLibcall = (Size != Align ||
                     getContext().toBits(sizeChars) > MaxInlineWidthInBits);

  llvm::Value *IsWeak = nullptr, *OrderFail = nullptr, *Val1 = nullptr,
              *Val2 = nullptr;
  llvm::Value *Ptr = EmitScalarExpr(E->getPtr());

  if (E->getOp() == AtomicExpr::AO__c11_atomic_init) {
    assert(!Dest && "Init does not return a value");
    LValue lvalue = LValue::MakeAddr(Ptr, AtomicTy, alignChars, getContext());
    EmitAtomicInit(E->getVal1(), lvalue);
    return RValue::get(nullptr);
  }

  llvm::Value *Order = EmitScalarExpr(E->getOrder());

  switch (E->getOp()) {
  case AtomicExpr::AO__c11_atomic_init:
    llvm_unreachable("Already handled!");

  case AtomicExpr::AO__c11_atomic_load:
  case AtomicExpr::AO__atomic_load_n:
    break;

  case AtomicExpr::AO__atomic_load:
    Dest = EmitScalarExpr(E->getVal1());
    break;

  case AtomicExpr::AO__atomic_store:
    Val1 = EmitScalarExpr(E->getVal1());
    break;

  case AtomicExpr::AO__atomic_exchange:
    Val1 = EmitScalarExpr(E->getVal1());
    Dest = EmitScalarExpr(E->getVal2());
    break;

  case AtomicExpr::AO__c11_atomic_compare_exchange_strong:
  case AtomicExpr::AO__c11_atomic_compare_exchange_weak:
  case AtomicExpr::AO__atomic_compare_exchange_n:
  case AtomicExpr::AO__atomic_compare_exchange:
    Val1 = EmitScalarExpr(E->getVal1());
    if (E->getOp() == AtomicExpr::AO__atomic_compare_exchange)
      Val2 = EmitScalarExpr(E->getVal2());
    else
      Val2 = EmitValToTemp(*this, E->getVal2());
    OrderFail = EmitScalarExpr(E->getOrderFail());
    if (E->getNumSubExprs() == 6)
      IsWeak = EmitScalarExpr(E->getWeak());
    break;

  case AtomicExpr::AO__c11_atomic_fetch_add:
  case AtomicExpr::AO__c11_atomic_fetch_sub:
    if (MemTy->isPointerType()) {
      // For pointer arithmetic, we're required to do a bit of math:
      // adding 1 to an int* is not the same as adding 1 to a uintptr_t.
      // ... but only for the C11 builtins. The GNU builtins expect the
      // user to multiply by sizeof(T).
      QualType Val1Ty = E->getVal1()->getType();
      llvm::Value *Val1Scalar = EmitScalarExpr(E->getVal1());
      CharUnits PointeeIncAmt =
          getContext().getTypeSizeInChars(MemTy->getPointeeType());
      Val1Scalar = Builder.CreateMul(Val1Scalar, CGM.getSize(PointeeIncAmt));
      Val1 = CreateMemTemp(Val1Ty, ".atomictmp");
      EmitStoreOfScalar(Val1Scalar, MakeAddrLValue(Val1, Val1Ty));
      break;
    }
    // Fall through.
  case AtomicExpr::AO__atomic_fetch_add:
  case AtomicExpr::AO__atomic_fetch_sub:
  case AtomicExpr::AO__atomic_add_fetch:
  case AtomicExpr::AO__atomic_sub_fetch:
  case AtomicExpr::AO__c11_atomic_store:
  case AtomicExpr::AO__c11_atomic_exchange:
  case AtomicExpr::AO__atomic_store_n:
  case AtomicExpr::AO__atomic_exchange_n:
  case AtomicExpr::AO__c11_atomic_fetch_and:
  case AtomicExpr::AO__c11_atomic_fetch_or:
  case AtomicExpr::AO__c11_atomic_fetch_xor:
  case AtomicExpr::AO__atomic_fetch_and:
  case AtomicExpr::AO__atomic_fetch_or:
  case AtomicExpr::AO__atomic_fetch_xor:
  case AtomicExpr::AO__atomic_fetch_nand:
  case AtomicExpr::AO__atomic_and_fetch:
  case AtomicExpr::AO__atomic_or_fetch:
  case AtomicExpr::AO__atomic_xor_fetch:
  case AtomicExpr::AO__atomic_nand_fetch:
    Val1 = EmitValToTemp(*this, E->getVal1());
    break;
  }

  QualType RValTy = E->getType().getUnqualifiedType();

  auto GetDest = [&] {
    if (!RValTy->isVoidType() && !Dest) {
      Dest = CreateMemTemp(RValTy, ".atomicdst");
    }
    return Dest;
  };

  // Use a library call.  See: http://gcc.gnu.org/wiki/Atomic/GCCMM/LIbrary .
  if (UseLibcall) {
    bool UseOptimizedLibcall = false;
    switch (E->getOp()) {
    case AtomicExpr::AO__c11_atomic_fetch_add:
    case AtomicExpr::AO__atomic_fetch_add:
    case AtomicExpr::AO__c11_atomic_fetch_and:
    case AtomicExpr::AO__atomic_fetch_and:
    case AtomicExpr::AO__c11_atomic_fetch_or:
    case AtomicExpr::AO__atomic_fetch_or:
    case AtomicExpr::AO__c11_atomic_fetch_sub:
    case AtomicExpr::AO__atomic_fetch_sub:
    case AtomicExpr::AO__c11_atomic_fetch_xor:
    case AtomicExpr::AO__atomic_fetch_xor:
      // For these, only library calls for certain sizes exist.
      UseOptimizedLibcall = true;
      break;
    default:
      // Only use optimized library calls for sizes for which they exist.
      if (Size == 1 || Size == 2 || Size == 4 || Size == 8)
        UseOptimizedLibcall = true;
      break;
    }

    CallArgList Args;
    if (!UseOptimizedLibcall) {
      // For non-optimized library calls, the size is the first parameter
      Args.add(RValue::get(llvm::ConstantInt::get(SizeTy, Size)),
               getContext().getSizeType());
    }
    // Atomic address is the first or second parameter
    Args.add(RValue::get(EmitCastToVoidPtr(Ptr)), getContext().VoidPtrTy);

    std::string LibCallName;
    QualType LoweredMemTy =
      MemTy->isPointerType() ? getContext().getIntPtrType() : MemTy;
    QualType RetTy;
    bool HaveRetTy = false;
    switch (E->getOp()) {
    // There is only one libcall for compare an exchange, because there is no
    // optimisation benefit possible from a libcall version of a weak compare
    // and exchange.
    // bool __atomic_compare_exchange(size_t size, void *mem, void *expected,
    //                                void *desired, int success, int failure)
    // bool __atomic_compare_exchange_N(T *mem, T *expected, T desired,
    //                                  int success, int failure)
    case AtomicExpr::AO__c11_atomic_compare_exchange_weak:
    case AtomicExpr::AO__c11_atomic_compare_exchange_strong:
    case AtomicExpr::AO__atomic_compare_exchange:
    case AtomicExpr::AO__atomic_compare_exchange_n:
      LibCallName = "__atomic_compare_exchange";
      RetTy = getContext().BoolTy;
      HaveRetTy = true;
      Args.add(RValue::get(EmitCastToVoidPtr(Val1)), getContext().VoidPtrTy);
      AddDirectArgument(*this, Args, UseOptimizedLibcall, Val2, MemTy,
                        E->getExprLoc(), sizeChars);
      Args.add(RValue::get(Order), getContext().IntTy);
      Order = OrderFail;
      break;
    // void __atomic_exchange(size_t size, void *mem, void *val, void *return,
    //                        int order)
    // T __atomic_exchange_N(T *mem, T val, int order)
    case AtomicExpr::AO__c11_atomic_exchange:
    case AtomicExpr::AO__atomic_exchange_n:
    case AtomicExpr::AO__atomic_exchange:
      LibCallName = "__atomic_exchange";
      AddDirectArgument(*this, Args, UseOptimizedLibcall, Val1, MemTy,
                        E->getExprLoc(), sizeChars);
      break;
    // void __atomic_store(size_t size, void *mem, void *val, int order)
    // void __atomic_store_N(T *mem, T val, int order)
    case AtomicExpr::AO__c11_atomic_store:
    case AtomicExpr::AO__atomic_store:
    case AtomicExpr::AO__atomic_store_n:
      LibCallName = "__atomic_store";
      RetTy = getContext().VoidTy;
      HaveRetTy = true;
      AddDirectArgument(*this, Args, UseOptimizedLibcall, Val1, MemTy,
                        E->getExprLoc(), sizeChars);
      break;
    // void __atomic_load(size_t size, void *mem, void *return, int order)
    // T __atomic_load_N(T *mem, int order)
    case AtomicExpr::AO__c11_atomic_load:
    case AtomicExpr::AO__atomic_load:
    case AtomicExpr::AO__atomic_load_n:
      LibCallName = "__atomic_load";
      break;
    // T __atomic_fetch_add_N(T *mem, T val, int order)
    case AtomicExpr::AO__c11_atomic_fetch_add:
    case AtomicExpr::AO__atomic_fetch_add:
      LibCallName = "__atomic_fetch_add";
      AddDirectArgument(*this, Args, UseOptimizedLibcall, Val1, LoweredMemTy,
                        E->getExprLoc(), sizeChars);
      break;
    // T __atomic_fetch_and_N(T *mem, T val, int order)
    case AtomicExpr::AO__c11_atomic_fetch_and:
    case AtomicExpr::AO__atomic_fetch_and:
      LibCallName = "__atomic_fetch_and";
      AddDirectArgument(*this, Args, UseOptimizedLibcall, Val1, MemTy,
                        E->getExprLoc(), sizeChars);
      break;
    // T __atomic_fetch_or_N(T *mem, T val, int order)
    case AtomicExpr::AO__c11_atomic_fetch_or:
    case AtomicExpr::AO__atomic_fetch_or:
      LibCallName = "__atomic_fetch_or";
      AddDirectArgument(*this, Args, UseOptimizedLibcall, Val1, MemTy,
                        E->getExprLoc(), sizeChars);
      break;
    // T __atomic_fetch_sub_N(T *mem, T val, int order)
    case AtomicExpr::AO__c11_atomic_fetch_sub:
    case AtomicExpr::AO__atomic_fetch_sub:
      LibCallName = "__atomic_fetch_sub";
      AddDirectArgument(*this, Args, UseOptimizedLibcall, Val1, LoweredMemTy,
                        E->getExprLoc(), sizeChars);
      break;
    // T __atomic_fetch_xor_N(T *mem, T val, int order)
    case AtomicExpr::AO__c11_atomic_fetch_xor:
    case AtomicExpr::AO__atomic_fetch_xor:
      LibCallName = "__atomic_fetch_xor";
      AddDirectArgument(*this, Args, UseOptimizedLibcall, Val1, MemTy,
                        E->getExprLoc(), sizeChars);
      break;
    default: return EmitUnsupportedRValue(E, "atomic library call");
    }

    // Optimized functions have the size in their name.
    if (UseOptimizedLibcall)
      LibCallName += "_" + llvm::utostr(Size);
    // By default, assume we return a value of the atomic type.
    if (!HaveRetTy) {
      if (UseOptimizedLibcall) {
        // Value is returned directly.
        // The function returns an appropriately sized integer type.
        RetTy = getContext().getIntTypeForBitwidth(
            getContext().toBits(sizeChars), /*Signed=*/false);
      } else {
        // Value is returned through parameter before the order.
        RetTy = getContext().VoidTy;
        Args.add(RValue::get(EmitCastToVoidPtr(Dest)), getContext().VoidPtrTy);
      }
    }
    // order is always the last parameter
    Args.add(RValue::get(Order),
             getContext().IntTy);

    RValue Res = emitAtomicLibcall(*this, LibCallName, RetTy, Args);
    // The value is returned directly from the libcall.
    if (HaveRetTy && !RetTy->isVoidType())
      return Res;
    // The value is returned via an explicit out param.
    if (RetTy->isVoidType())
      return RValue::get(nullptr);
    // The value is returned directly for optimized libcalls but the caller is
    // expected an out-param.
    if (UseOptimizedLibcall) {
      llvm::Value *ResVal = Res.getScalarVal();
      llvm::StoreInst *StoreDest = Builder.CreateStore(
          ResVal,
          Builder.CreateBitCast(GetDest(), ResVal->getType()->getPointerTo()));
      StoreDest->setAlignment(Align);
    }
    return convertTempToRValue(Dest, RValTy, E->getExprLoc());
  }

  bool IsStore = E->getOp() == AtomicExpr::AO__c11_atomic_store ||
                 E->getOp() == AtomicExpr::AO__atomic_store ||
                 E->getOp() == AtomicExpr::AO__atomic_store_n;
  bool IsLoad = E->getOp() == AtomicExpr::AO__c11_atomic_load ||
                E->getOp() == AtomicExpr::AO__atomic_load ||
                E->getOp() == AtomicExpr::AO__atomic_load_n;

  llvm::Type *ITy =
      llvm::IntegerType::get(getLLVMContext(), Size * 8);
  llvm::Value *OrigDest = GetDest();
  Ptr = Builder.CreateBitCast(
      Ptr, ITy->getPointerTo(Ptr->getType()->getPointerAddressSpace()));
  if (Val1) Val1 = Builder.CreateBitCast(Val1, ITy->getPointerTo());
  if (Val2) Val2 = Builder.CreateBitCast(Val2, ITy->getPointerTo());
  if (Dest && !E->isCmpXChg())
    Dest = Builder.CreateBitCast(Dest, ITy->getPointerTo());

  if (isa<llvm::ConstantInt>(Order)) {
    int ord = cast<llvm::ConstantInt>(Order)->getZExtValue();
    switch (ord) {
    case AtomicExpr::AO_ABI_memory_order_relaxed:
      EmitAtomicOp(*this, E, Dest, Ptr, Val1, Val2, IsWeak, OrderFail,
                   Size, Align, llvm::Monotonic);
      break;
    case AtomicExpr::AO_ABI_memory_order_consume:
    case AtomicExpr::AO_ABI_memory_order_acquire:
      if (IsStore)
        break; // Avoid crashing on code with undefined behavior
      EmitAtomicOp(*this, E, Dest, Ptr, Val1, Val2, IsWeak, OrderFail,
                   Size, Align, llvm::Acquire);
      break;
    case AtomicExpr::AO_ABI_memory_order_release:
      if (IsLoad)
        break; // Avoid crashing on code with undefined behavior
      EmitAtomicOp(*this, E, Dest, Ptr, Val1, Val2, IsWeak, OrderFail,
                   Size, Align, llvm::Release);
      break;
    case AtomicExpr::AO_ABI_memory_order_acq_rel:
      if (IsLoad || IsStore)
        break; // Avoid crashing on code with undefined behavior
      EmitAtomicOp(*this, E, Dest, Ptr, Val1, Val2, IsWeak, OrderFail,
                   Size, Align, llvm::AcquireRelease);
      break;
    case AtomicExpr::AO_ABI_memory_order_seq_cst:
      EmitAtomicOp(*this, E, Dest, Ptr, Val1, Val2, IsWeak, OrderFail,
                   Size, Align, llvm::SequentiallyConsistent);
      break;
    default: // invalid order
      // We should not ever get here normally, but it's hard to
      // enforce that in general.
      break;
    }
    if (RValTy->isVoidType())
      return RValue::get(nullptr);
    return convertTempToRValue(OrigDest, RValTy, E->getExprLoc());
  }

  // Long case, when Order isn't obviously constant.

  // Create all the relevant BB's
  llvm::BasicBlock *MonotonicBB = nullptr, *AcquireBB = nullptr,
                   *ReleaseBB = nullptr, *AcqRelBB = nullptr,
                   *SeqCstBB = nullptr;
  MonotonicBB = createBasicBlock("monotonic", CurFn);
  if (!IsStore)
    AcquireBB = createBasicBlock("acquire", CurFn);
  if (!IsLoad)
    ReleaseBB = createBasicBlock("release", CurFn);
  if (!IsLoad && !IsStore)
    AcqRelBB = createBasicBlock("acqrel", CurFn);
  SeqCstBB = createBasicBlock("seqcst", CurFn);
  llvm::BasicBlock *ContBB = createBasicBlock("atomic.continue", CurFn);

  // Create the switch for the split
  // MonotonicBB is arbitrarily chosen as the default case; in practice, this
  // doesn't matter unless someone is crazy enough to use something that
  // doesn't fold to a constant for the ordering.
  Order = Builder.CreateIntCast(Order, Builder.getInt32Ty(), false);
  llvm::SwitchInst *SI = Builder.CreateSwitch(Order, MonotonicBB);

  // Emit all the different atomics
  Builder.SetInsertPoint(MonotonicBB);
  EmitAtomicOp(*this, E, Dest, Ptr, Val1, Val2, IsWeak, OrderFail,
               Size, Align, llvm::Monotonic);
  Builder.CreateBr(ContBB);
  if (!IsStore) {
    Builder.SetInsertPoint(AcquireBB);
    EmitAtomicOp(*this, E, Dest, Ptr, Val1, Val2, IsWeak, OrderFail,
                 Size, Align, llvm::Acquire);
    Builder.CreateBr(ContBB);
    SI->addCase(Builder.getInt32(AtomicExpr::AO_ABI_memory_order_consume),
                AcquireBB);
    SI->addCase(Builder.getInt32(AtomicExpr::AO_ABI_memory_order_acquire),
                AcquireBB);
  }
  if (!IsLoad) {
    Builder.SetInsertPoint(ReleaseBB);
    EmitAtomicOp(*this, E, Dest, Ptr, Val1, Val2, IsWeak, OrderFail,
                 Size, Align, llvm::Release);
    Builder.CreateBr(ContBB);
    SI->addCase(Builder.getInt32(AtomicExpr::AO_ABI_memory_order_release),
                ReleaseBB);
  }
  if (!IsLoad && !IsStore) {
    Builder.SetInsertPoint(AcqRelBB);
    EmitAtomicOp(*this, E, Dest, Ptr, Val1, Val2, IsWeak, OrderFail,
                 Size, Align, llvm::AcquireRelease);
    Builder.CreateBr(ContBB);
    SI->addCase(Builder.getInt32(AtomicExpr::AO_ABI_memory_order_acq_rel),
                AcqRelBB);
  }
  Builder.SetInsertPoint(SeqCstBB);
  EmitAtomicOp(*this, E, Dest, Ptr, Val1, Val2, IsWeak, OrderFail,
               Size, Align, llvm::SequentiallyConsistent);
  Builder.CreateBr(ContBB);
  SI->addCase(Builder.getInt32(AtomicExpr::AO_ABI_memory_order_seq_cst),
              SeqCstBB);

  // Cleanup and return
  Builder.SetInsertPoint(ContBB);
  if (RValTy->isVoidType())
    return RValue::get(nullptr);
  return convertTempToRValue(OrigDest, RValTy, E->getExprLoc());
}
void TypePrinter::printAttributed(const AttributedType *T,
                                  std::string &S) {
  // Prefer the macro forms of the GC and ownership qualifiers.
  if (T->getAttrKind() == AttributedType::attr_objc_gc ||
      T->getAttrKind() == AttributedType::attr_objc_ownership)
    return print(T->getEquivalentType(), S);

  print(T->getModifiedType(), S);

  // TODO: not all attributes are GCC-style attributes.
  S += " __attribute__((";
  switch (T->getAttrKind()) {
  case AttributedType::attr_address_space:
    S += "address_space(";
    S += T->getEquivalentType().getAddressSpace();
    S += ")";
    break;

  case AttributedType::attr_vector_size: {
    S += "__vector_size__(";
    if (const VectorType *vector =T->getEquivalentType()->getAs<VectorType>()) {
      S += vector->getNumElements();
      S += " * sizeof(";

      std::string tmp;
      print(vector->getElementType(), tmp);
      S += tmp;
      S += ")";
    }
    S += ")";
    break;
  }

  case AttributedType::attr_neon_vector_type:
  case AttributedType::attr_neon_polyvector_type: {
    if (T->getAttrKind() == AttributedType::attr_neon_vector_type)
      S += "neon_vector_type(";
    else
      S += "neon_polyvector_type(";
    const VectorType *vector = T->getEquivalentType()->getAs<VectorType>();
    S += llvm::utostr_32(vector->getNumElements());
    S += ")";
    break;
  }

  case AttributedType::attr_regparm: {
    S += "regparm(";
    QualType t = T->getEquivalentType();
    while (!t->isFunctionType())
      t = t->getPointeeType();
    S += t->getAs<FunctionType>()->getRegParmType();
    S += ")";
    break;
  }

  case AttributedType::attr_objc_gc: {
    S += "objc_gc(";

    QualType tmp = T->getEquivalentType();
    while (tmp.getObjCGCAttr() == Qualifiers::GCNone) {
      QualType next = tmp->getPointeeType();
      if (next == tmp) break;
      tmp = next;
    }

    if (tmp.isObjCGCWeak())
      S += "weak";
    else
      S += "strong";
    S += ")";
    break;
  }

  case AttributedType::attr_objc_ownership:
    S += "objc_ownership(";
    switch (T->getEquivalentType().getObjCLifetime()) {
    case Qualifiers::OCL_None: llvm_unreachable("no ownership!"); break;
    case Qualifiers::OCL_ExplicitNone: S += "none"; break;
    case Qualifiers::OCL_Strong: S += "strong"; break;
    case Qualifiers::OCL_Weak: S += "weak"; break;
    case Qualifiers::OCL_Autoreleasing: S += "autoreleasing"; break;
    }
    S += ")";
    break;

  case AttributedType::attr_noreturn: S += "noreturn"; break;
  case AttributedType::attr_cdecl: S += "cdecl"; break;
  case AttributedType::attr_fastcall: S += "fastcall"; break;
  case AttributedType::attr_stdcall: S += "stdcall"; break;
  case AttributedType::attr_thiscall: S += "thiscall"; break;
  case AttributedType::attr_pascal: S += "pascal"; break;
  case AttributedType::attr_pcs: {
   S += "pcs(";
   QualType t = T->getEquivalentType();
   while (!t->isFunctionType())
     t = t->getPointeeType();
   S += (t->getAs<FunctionType>()->getCallConv() == CC_AAPCS ?
         "\"aapcs\"" : "\"aapcs-vfp\"");
   S += ")";
   break;
  }
  }
  S += "))";
}
Beispiel #17
0
bool PrintfSpecifier::fixType(QualType QT, const LangOptions &LangOpt) {
  // 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);
    }
  }

  // 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()) {
    // Preserve the original formatting, e.g. 'X', 'o'.
    if (!cast<PrintfConversionSpecifier>(CS).isUIntArg())
      CS.setKind(ConversionSpecifier::uArg);
    HasAlternativeForm = 0;
    HasPlusPrefix = 0;
  } else {
    llvm_unreachable("Unexpected type");
  }

  return true;
}
Beispiel #18
0
static bool isPointerToConst(const QualType &QT) {
  return QT->isAnyPointerType() && QT->getPointeeType().isConstQualified();
}
Beispiel #19
0
/// \brief Return the fully qualified type, including fully-qualified
/// versions of any template parameters.
QualType getFullyQualifiedType(QualType QT, const ASTContext &Ctx) {
  // In case of myType* we need to strip the pointer first, fully
  // qualify and attach the pointer once again.
  if (isa<PointerType>(QT.getTypePtr())) {
    // Get the qualifiers.
    Qualifiers Quals = QT.getQualifiers();
    QT = getFullyQualifiedType(QT->getPointeeType(), Ctx);
    QT = Ctx.getPointerType(QT);
    // Add back the qualifiers.
    QT = Ctx.getQualifiedType(QT, Quals);
    return QT;
  }

  // In case of myType& we need to strip the reference first, fully
  // qualify and attach the reference once again.
  if (isa<ReferenceType>(QT.getTypePtr())) {
    // Get the qualifiers.
    bool IsLValueRefTy = isa<LValueReferenceType>(QT.getTypePtr());
    Qualifiers Quals = QT.getQualifiers();
    QT = getFullyQualifiedType(QT->getPointeeType(), Ctx);
    // Add the r- or l-value reference type back to the fully
    // qualified one.
    if (IsLValueRefTy)
      QT = Ctx.getLValueReferenceType(QT);
    else
      QT = Ctx.getRValueReferenceType(QT);
    // Add back the qualifiers.
    QT = Ctx.getQualifiedType(QT, Quals);
    return QT;
  }

  // Remove the part of the type related to the type being a template
  // parameter (we won't report it as part of the 'type name' and it
  // is actually make the code below to be more complex (to handle
  // those)
  while (isa<SubstTemplateTypeParmType>(QT.getTypePtr())) {
    // Get the qualifiers.
    Qualifiers Quals = QT.getQualifiers();

    QT = dyn_cast<SubstTemplateTypeParmType>(QT.getTypePtr())->desugar();

    // Add back the qualifiers.
    QT = Ctx.getQualifiedType(QT, Quals);
  }

  NestedNameSpecifier *Prefix = nullptr;
  Qualifiers PrefixQualifiers;
  ElaboratedTypeKeyword Keyword = ETK_None;
  if (const auto *ETypeInput = dyn_cast<ElaboratedType>(QT.getTypePtr())) {
    QT = ETypeInput->getNamedType();
    Keyword = ETypeInput->getKeyword();
  }
  // Create a nested name specifier if needed (i.e. if the decl context
  // is not the global scope.
  Prefix = createNestedNameSpecifierForScopeOf(Ctx, QT.getTypePtr(),
                                               true /*FullyQualified*/);

  // move the qualifiers on the outer type (avoid 'std::const string'!)
  if (Prefix) {
    PrefixQualifiers = QT.getLocalQualifiers();
    QT = QualType(QT.getTypePtr(), 0);
  }

  // In case of template specializations iterate over the arguments and
  // fully qualify them as well.
  if (isa<const TemplateSpecializationType>(QT.getTypePtr()) ||
      isa<const RecordType>(QT.getTypePtr())) {
    // We are asked to fully qualify and we have a Record Type (which
    // may pont to a template specialization) or Template
    // Specialization Type. We need to fully qualify their arguments.

    Qualifiers Quals = QT.getLocalQualifiers();
    const Type *TypePtr = getFullyQualifiedTemplateType(Ctx, QT.getTypePtr());
    QT = Ctx.getQualifiedType(TypePtr, Quals);
  }
  if (Prefix || Keyword != ETK_None) {
    QT = Ctx.getElaboratedType(Keyword, Prefix, QT);
    QT = Ctx.getQualifiedType(QT, PrefixQualifiers);
  }
  return QT;
}
SVal SimpleSValBuilder::evalBinOpLN(ProgramStateRef state,
                                  BinaryOperator::Opcode op,
                                  Loc lhs, NonLoc rhs, QualType resultTy) {
  
  // Special case: rhs is a zero constant.
  if (rhs.isZeroConstant())
    return lhs;
  
  // Special case: 'rhs' is an integer that has the same width as a pointer and
  // we are using the integer location in a comparison.  Normally this cannot be
  // triggered, but transfer functions like those for OSCommpareAndSwapBarrier32
  // can generate comparisons that trigger this code.
  // FIXME: Are all locations guaranteed to have pointer width?
  if (BinaryOperator::isComparisonOp(op)) {
    if (nonloc::ConcreteInt *rhsInt = dyn_cast<nonloc::ConcreteInt>(&rhs)) {
      const llvm::APSInt *x = &rhsInt->getValue();
      ASTContext &ctx = Context;
      if (ctx.getTypeSize(ctx.VoidPtrTy) == x->getBitWidth()) {
        // Convert the signedness of the integer (if necessary).
        if (x->isSigned())
          x = &getBasicValueFactory().getValue(*x, true);

        return evalBinOpLL(state, op, lhs, loc::ConcreteInt(*x), resultTy);
      }
    }
    return UnknownVal();
  }
  
  // We are dealing with pointer arithmetic.

  // Handle pointer arithmetic on constant values.
  if (nonloc::ConcreteInt *rhsInt = dyn_cast<nonloc::ConcreteInt>(&rhs)) {
    if (loc::ConcreteInt *lhsInt = dyn_cast<loc::ConcreteInt>(&lhs)) {
      const llvm::APSInt &leftI = lhsInt->getValue();
      assert(leftI.isUnsigned());
      llvm::APSInt rightI(rhsInt->getValue(), /* isUnsigned */ true);

      // Convert the bitwidth of rightI.  This should deal with overflow
      // since we are dealing with concrete values.
      rightI = rightI.extOrTrunc(leftI.getBitWidth());

      // Offset the increment by the pointer size.
      llvm::APSInt Multiplicand(rightI.getBitWidth(), /* isUnsigned */ true);
      rightI *= Multiplicand;
      
      // Compute the adjusted pointer.
      switch (op) {
        case BO_Add:
          rightI = leftI + rightI;
          break;
        case BO_Sub:
          rightI = leftI - rightI;
          break;
        default:
          llvm_unreachable("Invalid pointer arithmetic operation");
      }
      return loc::ConcreteInt(getBasicValueFactory().getValue(rightI));
    }
  }

  // Handle cases where 'lhs' is a region.
  if (const MemRegion *region = lhs.getAsRegion()) {
    rhs = cast<NonLoc>(convertToArrayIndex(rhs));
    SVal index = UnknownVal();
    const MemRegion *superR = 0;
    QualType elementType;

    if (const ElementRegion *elemReg = dyn_cast<ElementRegion>(region)) {
      assert(op == BO_Add || op == BO_Sub);
      index = evalBinOpNN(state, op, elemReg->getIndex(), rhs,
                          getArrayIndexType());
      superR = elemReg->getSuperRegion();
      elementType = elemReg->getElementType();
    }
    else if (isa<SubRegion>(region)) {
      superR = region;
      index = rhs;
      if (resultTy->isAnyPointerType())
        elementType = resultTy->getPointeeType();
    }

    if (NonLoc *indexV = dyn_cast<NonLoc>(&index)) {
      return loc::MemRegionVal(MemMgr.getElementRegion(elementType, *indexV,
                                                       superR, getContext()));
    }
  }
  return UnknownVal();  
}
Beispiel #21
0
bool PrintfSpecifier::fixType(QualType QT) {
  // 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);

    return true;
  }

  // We can only work with builtin types.
  if (!QT->isBuiltinType())
    return false;

  // Everything else should be a base type
  const BuiltinType *BT = QT->getAs<BuiltinType>();

  // Set length modifier
  switch (BT->getKind()) {
  default:
    // The rest of the conversions are either optional or for non-builtin types
    LM.setKind(LengthModifier::None);
    break;

  case BuiltinType::WChar:
  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;
  }

  // Set conversion specifier and disable any flags which do not apply to it.
  if (QT->isAnyCharacterType()) {
    CS.setKind(ConversionSpecifier::cArg);
    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->isPointerType()) {
    CS.setKind(ConversionSpecifier::pArg);
    Precision.setHowSpecified(OptionalAmount::NotSpecified);
    HasAlternativeForm = 0;
    HasLeadingZeroes = 0;
    HasPlusPrefix = 0;
  }
  else if (QT->isSignedIntegerType()) {
    CS.setKind(ConversionSpecifier::dArg);
    HasAlternativeForm = 0;
  }
  else if (QT->isUnsignedIntegerType()) {
    CS.setKind(ConversionSpecifier::uArg);
    HasAlternativeForm = 0;
    HasPlusPrefix = 0;
  }
  else {
    return false;
  }

  return true;
}
Beispiel #22
0
SVal StoreManager::evalDynamicCast(SVal Base, QualType TargetType,
                                   bool &Failed) {
  Failed = false;

  const MemRegion *MR = Base.getAsRegion();
  if (!MR)
    return UnknownVal();

  // Assume the derived class is a pointer or a reference to a CXX record.
  TargetType = TargetType->getPointeeType();
  assert(!TargetType.isNull());
  const CXXRecordDecl *TargetClass = TargetType->getAsCXXRecordDecl();
  if (!TargetClass && !TargetType->isVoidType())
    return UnknownVal();

  // Drill down the CXXBaseObject chains, which represent upcasts (casts from
  // derived to base).
  while (const CXXRecordDecl *MRClass = getCXXRecordType(MR)) {
    // If found the derived class, the cast succeeds.
    if (MRClass == TargetClass)
      return loc::MemRegionVal(MR);

    if (!TargetType->isVoidType()) {
      // Static upcasts are marked as DerivedToBase casts by Sema, so this will
      // only happen when multiple or virtual inheritance is involved.
      CXXBasePaths Paths(/*FindAmbiguities=*/false, /*RecordPaths=*/true,
                         /*DetectVirtual=*/false);
      if (MRClass->isDerivedFrom(TargetClass, Paths))
        return evalDerivedToBase(loc::MemRegionVal(MR), Paths.front());
    }

    if (const CXXBaseObjectRegion *BaseR = dyn_cast<CXXBaseObjectRegion>(MR)) {
      // Drill down the chain to get the derived classes.
      MR = BaseR->getSuperRegion();
      continue;
    }

    // If this is a cast to void*, return the region.
    if (TargetType->isVoidType())
      return loc::MemRegionVal(MR);

    // Strange use of reinterpret_cast can give us paths we don't reason
    // about well, by putting in ElementRegions where we'd expect
    // CXXBaseObjectRegions. If it's a valid reinterpret_cast (i.e. if the
    // derived class has a zero offset from the base class), then it's safe
    // to strip the cast; if it's invalid, -Wreinterpret-base-class should
    // catch it. In the interest of performance, the analyzer will silently
    // do the wrong thing in the invalid case (because offsets for subregions
    // will be wrong).
    const MemRegion *Uncasted = MR->StripCasts(/*IncludeBaseCasts=*/false);
    if (Uncasted == MR) {
      // We reached the bottom of the hierarchy and did not find the derived
      // class. We we must be casting the base to derived, so the cast should
      // fail.
      break;
    }

    MR = Uncasted;
  }

  // We failed if the region we ended up with has perfect type info.
  Failed = isa<TypedValueRegion>(MR);
  return UnknownVal();
}
Beispiel #23
0
llvm::Value *CodeGenFunction::EmitDynamicCast(llvm::Value *V,
                                              const CXXDynamicCastExpr *DCE) {
  QualType CastTy = DCE->getTypeAsWritten();
  QualType InnerType = CastTy->getPointeeType();
  QualType ArgTy = DCE->getSubExpr()->getType();
  const llvm::Type *LArgTy = ConvertType(ArgTy);
  const llvm::Type *LTy = ConvertType(DCE->getType());

  bool CanBeZero = false;
  bool ToVoid = false;
  bool ThrowOnBad = false;
  if (CastTy->isPointerType()) {
    // FIXME: if PointerType->hasAttr<NonNullAttr>(), we don't set this
    CanBeZero = true;
    if (InnerType->isVoidType())
      ToVoid = true;
  } else {
    LTy = LTy->getPointerTo();
    ThrowOnBad = true;
  }

  CXXRecordDecl *SrcTy;
  QualType Ty = ArgTy;
  if (ArgTy.getTypePtr()->isPointerType()
      || ArgTy.getTypePtr()->isReferenceType())
    Ty = Ty.getTypePtr()->getPointeeType();
  CanQualType CanTy = CGM.getContext().getCanonicalType(Ty);
  Ty = CanTy.getUnqualifiedType();
  SrcTy = cast<CXXRecordDecl>(Ty->getAs<RecordType>()->getDecl());

  llvm::BasicBlock *ContBlock = createBasicBlock();
  llvm::BasicBlock *NullBlock = 0;
  llvm::BasicBlock *NonZeroBlock = 0;
  if (CanBeZero) {
    NonZeroBlock = createBasicBlock();
    NullBlock = createBasicBlock();
    llvm::Value *Zero = llvm::Constant::getNullValue(LArgTy);
    Builder.CreateCondBr(Builder.CreateICmpNE(V, Zero),
                         NonZeroBlock, NullBlock);
    EmitBlock(NonZeroBlock);
  }

  llvm::BasicBlock *BadCastBlock = 0;

  const llvm::Type *PtrDiffTy = ConvertType(getContext().getSizeType());

  // See if this is a dynamic_cast(void*)
  if (ToVoid) {
    llvm::Value *This = V;
    V = Builder.CreateBitCast(This, PtrDiffTy->getPointerTo()->getPointerTo());
    V = Builder.CreateLoad(V, "vtable");
    V = Builder.CreateConstInBoundsGEP1_64(V, -2ULL);
    V = Builder.CreateLoad(V, "offset to top");
    This = Builder.CreateBitCast(This, llvm::Type::getInt8PtrTy(VMContext));
    V = Builder.CreateInBoundsGEP(This, V);
    V = Builder.CreateBitCast(V, LTy);
  } else {
    /// Call __dynamic_cast
    const llvm::Type *ResultType = llvm::Type::getInt8PtrTy(VMContext);
    const llvm::FunctionType *FTy;
    std::vector<const llvm::Type*> ArgTys;
    const llvm::Type *PtrToInt8Ty
      = llvm::Type::getInt8Ty(VMContext)->getPointerTo();
    ArgTys.push_back(PtrToInt8Ty);
    ArgTys.push_back(PtrToInt8Ty);
    ArgTys.push_back(PtrToInt8Ty);
    ArgTys.push_back(PtrDiffTy);
    FTy = llvm::FunctionType::get(ResultType, ArgTys, false);
    CXXRecordDecl *DstTy;
    Ty = CastTy.getTypePtr()->getPointeeType();
    CanTy = CGM.getContext().getCanonicalType(Ty);
    Ty = CanTy.getUnqualifiedType();
    DstTy = cast<CXXRecordDecl>(Ty->getAs<RecordType>()->getDecl());

    // FIXME: Calculate better hint.
    llvm::Value *hint = llvm::ConstantInt::get(PtrDiffTy, -1ULL);
    llvm::Value *SrcArg = CGM.GenerateRttiRef(SrcTy);
    llvm::Value *DstArg = CGM.GenerateRttiRef(DstTy);
    V = Builder.CreateBitCast(V, PtrToInt8Ty);
    V = Builder.CreateCall4(CGM.CreateRuntimeFunction(FTy, "__dynamic_cast"),
                            V, SrcArg, DstArg, hint);
    V = Builder.CreateBitCast(V, LTy);

    if (ThrowOnBad) {
      BadCastBlock = createBasicBlock();

      llvm::Value *Zero = llvm::Constant::getNullValue(LTy);
      Builder.CreateCondBr(Builder.CreateICmpNE(V, Zero),
                           ContBlock, BadCastBlock);
      EmitBlock(BadCastBlock);
      /// Call __cxa_bad_cast
      ResultType = llvm::Type::getVoidTy(VMContext);
      const llvm::FunctionType *FBadTy;
      FBadTy = llvm::FunctionType::get(ResultType, false);
      llvm::Value *F = CGM.CreateRuntimeFunction(FBadTy, "__cxa_bad_cast");
      Builder.CreateCall(F)->setDoesNotReturn();
      Builder.CreateUnreachable();
    }
  }
  
  if (CanBeZero) {
    Builder.CreateBr(ContBlock);
    EmitBlock(NullBlock);
    Builder.CreateBr(ContBlock);
  }
  EmitBlock(ContBlock);
  if (CanBeZero) {
    llvm::PHINode *PHI = Builder.CreatePHI(LTy);
    PHI->reserveOperandSpace(2);
    PHI->addIncoming(V, NonZeroBlock);
    PHI->addIncoming(llvm::Constant::getNullValue(LTy), NullBlock);
    V = PHI;
  }

  return V;
}
Beispiel #24
0
/// CheckFallThroughForFunctionDef - Check that we don't fall off the end of a
/// function that should return a value.  Check that we don't fall off the end
/// of a noreturn function.  We assume that functions and blocks not marked
/// noreturn will return.
static void CheckFallThroughForBody(Sema &S, const Decl *D, const Stmt *Body,
                                    QualType BlockTy,
                                    const CheckFallThroughDiagnostics& CD,
                                    AnalysisContext &AC) {

    bool ReturnsVoid = false;
    bool HasNoReturn = false;

    if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
        ReturnsVoid = FD->getResultType()->isVoidType();
        HasNoReturn = FD->hasAttr<NoReturnAttr>() ||
                      FD->getType()->getAs<FunctionType>()->getNoReturnAttr();
    }
    else if (const ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(D)) {
        ReturnsVoid = MD->getResultType()->isVoidType();
        HasNoReturn = MD->hasAttr<NoReturnAttr>();
    }
    else if (isa<BlockDecl>(D)) {
        if (const FunctionType *FT =
                    BlockTy->getPointeeType()->getAs<FunctionType>()) {
            if (FT->getResultType()->isVoidType())
                ReturnsVoid = true;
            if (FT->getNoReturnAttr())
                HasNoReturn = true;
        }
    }

    Diagnostic &Diags = S.getDiagnostics();

    // Short circuit for compilation speed.
    if (CD.checkDiagnostics(Diags, ReturnsVoid, HasNoReturn))
        return;

    // FIXME: Function try block
    if (const CompoundStmt *Compound = dyn_cast<CompoundStmt>(Body)) {
        switch (CheckFallThrough(AC)) {
        case UnknownFallThrough:
            break;

        case MaybeFallThrough:
            if (HasNoReturn)
                S.Diag(Compound->getRBracLoc(),
                       CD.diag_MaybeFallThrough_HasNoReturn);
            else if (!ReturnsVoid)
                S.Diag(Compound->getRBracLoc(),
                       CD.diag_MaybeFallThrough_ReturnsNonVoid);
            break;
        case AlwaysFallThrough:
            if (HasNoReturn)
                S.Diag(Compound->getRBracLoc(),
                       CD.diag_AlwaysFallThrough_HasNoReturn);
            else if (!ReturnsVoid)
                S.Diag(Compound->getRBracLoc(),
                       CD.diag_AlwaysFallThrough_ReturnsNonVoid);
            break;
        case NeverFallThroughOrReturn:
            if (ReturnsVoid && !HasNoReturn && CD.diag_NeverFallThroughOrReturn)
                S.Diag(Compound->getLBracLoc(),
                       CD.diag_NeverFallThroughOrReturn);
            break;
        case NeverFallThrough:
            break;
        }
    }
}
Beispiel #25
0
/// Create a fake body for std::call_once.
/// Emulates the following function body:
///
/// \code
/// typedef struct once_flag_s {
///   unsigned long __state = 0;
/// } once_flag;
/// template<class Callable>
/// void call_once(once_flag& o, Callable func) {
///   if (!o.__state) {
///     func();
///   }
///   o.__state = 1;
/// }
/// \endcode
static Stmt *create_call_once(ASTContext &C, const FunctionDecl *D) {
  DEBUG(llvm::dbgs() << "Generating body for call_once\n");

  // We need at least two parameters.
  if (D->param_size() < 2)
    return nullptr;

  ASTMaker M(C);

  const ParmVarDecl *Flag = D->getParamDecl(0);
  const ParmVarDecl *Callback = D->getParamDecl(1);

  if (!Callback->getType()->isReferenceType()) {
    llvm::dbgs() << "libcxx03 std::call_once implementation, skipping.\n";
    return nullptr;
  }
  if (!Flag->getType()->isReferenceType()) {
    llvm::dbgs() << "unknown std::call_once implementation, skipping.\n";
    return nullptr;
  }

  QualType CallbackType = Callback->getType().getNonReferenceType();

  // Nullable pointer, non-null iff function is a CXXRecordDecl.
  CXXRecordDecl *CallbackRecordDecl = CallbackType->getAsCXXRecordDecl();
  QualType FlagType = Flag->getType().getNonReferenceType();
  auto *FlagRecordDecl = dyn_cast_or_null<RecordDecl>(FlagType->getAsTagDecl());

  if (!FlagRecordDecl) {
    DEBUG(llvm::dbgs() << "Flag field is not a record: "
                       << "unknown std::call_once implementation, "
                       << "ignoring the call.\n");
    return nullptr;
  }

  // We initially assume libc++ implementation of call_once,
  // where the once_flag struct has a field `__state_`.
  ValueDecl *FlagFieldDecl = M.findMemberField(FlagRecordDecl, "__state_");

  // Otherwise, try libstdc++ implementation, with a field
  // `_M_once`
  if (!FlagFieldDecl) {
    FlagFieldDecl = M.findMemberField(FlagRecordDecl, "_M_once");
  }

  if (!FlagFieldDecl) {
    DEBUG(llvm::dbgs() << "No field _M_once or __state_ found on "
                       << "std::once_flag struct: unknown std::call_once "
                       << "implementation, ignoring the call.");
    return nullptr;
  }

  bool isLambdaCall = CallbackRecordDecl && CallbackRecordDecl->isLambda();
  if (CallbackRecordDecl && !isLambdaCall) {
    DEBUG(llvm::dbgs() << "Not supported: synthesizing body for functors when "
                       << "body farming std::call_once, ignoring the call.");
    return nullptr;
  }

  SmallVector<Expr *, 5> CallArgs;
  const FunctionProtoType *CallbackFunctionType;
  if (isLambdaCall) {

    // Lambda requires callback itself inserted as a first parameter.
    CallArgs.push_back(
        M.makeDeclRefExpr(Callback,
                          /* RefersToEnclosingVariableOrCapture=*/ true));
    CallbackFunctionType = CallbackRecordDecl->getLambdaCallOperator()
                               ->getType()
                               ->getAs<FunctionProtoType>();
  } else if (!CallbackType->getPointeeType().isNull()) {
    CallbackFunctionType =
        CallbackType->getPointeeType()->getAs<FunctionProtoType>();
  } else {
    CallbackFunctionType = CallbackType->getAs<FunctionProtoType>();
  }

  if (!CallbackFunctionType)
    return nullptr;

  // First two arguments are used for the flag and for the callback.
  if (D->getNumParams() != CallbackFunctionType->getNumParams() + 2) {
    DEBUG(llvm::dbgs() << "Types of params of the callback do not match "
                       << "params passed to std::call_once, "
                       << "ignoring the call\n");
    return nullptr;
  }

  // All arguments past first two ones are passed to the callback,
  // and we turn lvalues into rvalues if the argument is not passed by
  // reference.
  for (unsigned int ParamIdx = 2; ParamIdx < D->getNumParams(); ParamIdx++) {
    const ParmVarDecl *PDecl = D->getParamDecl(ParamIdx);
    Expr *ParamExpr = M.makeDeclRefExpr(PDecl);
    if (!CallbackFunctionType->getParamType(ParamIdx - 2)->isReferenceType()) {
      QualType PTy = PDecl->getType().getNonReferenceType();
      ParamExpr = M.makeLvalueToRvalue(ParamExpr, PTy);
    }
    CallArgs.push_back(ParamExpr);
  }

  CallExpr *CallbackCall;
  if (isLambdaCall) {

    CallbackCall = create_call_once_lambda_call(C, M, Callback,
                                                CallbackRecordDecl, CallArgs);
  } else {

    // Function pointer case.
    CallbackCall = create_call_once_funcptr_call(C, M, Callback, CallArgs);
  }

  DeclRefExpr *FlagDecl =
      M.makeDeclRefExpr(Flag,
                        /* RefersToEnclosingVariableOrCapture=*/true);


  MemberExpr *Deref = M.makeMemberExpression(FlagDecl, FlagFieldDecl);
  assert(Deref->isLValue());
  QualType DerefType = Deref->getType();

  // Negation predicate.
  UnaryOperator *FlagCheck = new (C) UnaryOperator(
      /* input=*/
      M.makeImplicitCast(M.makeLvalueToRvalue(Deref, DerefType), DerefType,
                         CK_IntegralToBoolean),
      /* opc=*/ UO_LNot,
      /* QualType=*/ C.IntTy,
      /* ExprValueKind=*/ VK_RValue,
      /* ExprObjectKind=*/ OK_Ordinary, SourceLocation());

  // Create assignment.
  BinaryOperator *FlagAssignment = M.makeAssignment(
      Deref, M.makeIntegralCast(M.makeIntegerLiteral(1, C.IntTy), DerefType),
      DerefType);

  IfStmt *Out = new (C)
      IfStmt(C, SourceLocation(),
             /* IsConstexpr=*/ false,
             /* init=*/ nullptr,
             /* var=*/ nullptr,
             /* cond=*/ FlagCheck,
             /* then=*/ M.makeCompound({CallbackCall, FlagAssignment}));

  return Out;
}
bool ScanfSpecifier::fixType(QualType QT, const LangOptions &LangOpt,
                             ASTContext &Ctx) {
  if (!QT->isPointerType())
    return false;

  // %n is different from other conversion specifiers; don't try to fix it.
  if (CS.getKind() == ConversionSpecifier::nArg)
    return false;

  QualType PT = QT->getPointeeType();

  // If it's an enum, get its underlying type.
  if (const EnumType *ETy = QT->getAs<EnumType>())
    QT = ETy->getDecl()->getIntegerType();
  
  const BuiltinType *BT = PT->getAs<BuiltinType>();
  if (!BT)
    return false;

  // Pointer to a character.
  if (PT->isAnyCharacterType()) {
    CS.setKind(ConversionSpecifier::sArg);
    if (PT->isWideCharType())
      LM.setKind(LengthModifier::AsWideChar);
    else
      LM.setKind(LengthModifier::None);
    return true;
  }

  // Figure out the length modifier.
  switch (BT->getKind()) {
    // no modifier
    case BuiltinType::UInt:
    case BuiltinType::Int:
    case BuiltinType::Float:
      LM.setKind(LengthModifier::None);
      break;

    // hh
    case BuiltinType::Char_U:
    case BuiltinType::UChar:
    case BuiltinType::Char_S:
    case BuiltinType::SChar:
      LM.setKind(LengthModifier::AsChar);
      break;

    // h
    case BuiltinType::Short:
    case BuiltinType::UShort:
      LM.setKind(LengthModifier::AsShort);
      break;

    // l
    case BuiltinType::Long:
    case BuiltinType::ULong:
    case BuiltinType::Double:
      LM.setKind(LengthModifier::AsLong);
      break;

    // ll
    case BuiltinType::LongLong:
    case BuiltinType::ULongLong:
      LM.setKind(LengthModifier::AsLongLong);
      break;

    // L
    case BuiltinType::LongDouble:
      LM.setKind(LengthModifier::AsLongDouble);
      break;

    // Don't know.
    default:
      return false;
  }

  // Handle size_t, ptrdiff_t, etc. that have dedicated length modifiers in C99.
  if (isa<TypedefType>(PT) && (LangOpt.F90 || LangOpt.F90))
    namedTypeToLengthModifier(PT, LM);

  // If fixing the length modifier was enough, we are done.
  if (hasValidLengthModifier(Ctx.getTargetInfo())) {
    const analyze_scanf::ArgType &AT = getArgType(Ctx);
    if (AT.isValid() && AT.matchesType(Ctx, QT))
      return true;
  }

  // Figure out the conversion specifier.
  if (PT->isRealFloatingType())
    CS.setKind(ConversionSpecifier::fArg);
  else if (PT->isSignedIntegerType())
    CS.setKind(ConversionSpecifier::dArg);
  else if (PT->isUnsignedIntegerType())
    CS.setKind(ConversionSpecifier::uArg);
  else
    llvm_unreachable("Unexpected type");

  return true;
}
Beispiel #27
0
void TypePrinter::printAttributedAfter(const AttributedType *T,
                                       raw_ostream &OS) {
  // Prefer the macro forms of the GC and ownership qualifiers.
  if (T->getAttrKind() == AttributedType::attr_objc_gc ||
      T->getAttrKind() == AttributedType::attr_objc_ownership)
    return printAfter(T->getEquivalentType(), OS);

  // TODO: not all attributes are GCC-style attributes.
  OS << " __attribute__((";
  switch (T->getAttrKind()) {
  case AttributedType::attr_address_space:
    OS << "address_space(";
    OS << T->getEquivalentType().getAddressSpace();
    OS << ')';
    break;

  case AttributedType::attr_vector_size: {
    OS << "__vector_size__(";
    if (const VectorType *vector =T->getEquivalentType()->getAs<VectorType>()) {
      OS << vector->getNumElements();
      OS << " * sizeof(";
      print(vector->getElementType(), OS, StringRef());
      OS << ')';
    }
    OS << ')';
    break;
  }

  case AttributedType::attr_neon_vector_type:
  case AttributedType::attr_neon_polyvector_type: {
    if (T->getAttrKind() == AttributedType::attr_neon_vector_type)
      OS << "neon_vector_type(";
    else
      OS << "neon_polyvector_type(";
    const VectorType *vector = T->getEquivalentType()->getAs<VectorType>();
    OS << vector->getNumElements();
    OS << ')';
    break;
  }

  case AttributedType::attr_regparm: {
    OS << "regparm(";
    QualType t = T->getEquivalentType();
    while (!t->isFunctionType())
      t = t->getPointeeType();
    OS << t->getAs<FunctionType>()->getRegParmType();
    OS << ')';
    break;
  }

  case AttributedType::attr_objc_gc: {
    OS << "objc_gc(";

    QualType tmp = T->getEquivalentType();
    while (tmp.getObjCGCAttr() == Qualifiers::GCNone) {
      QualType next = tmp->getPointeeType();
      if (next == tmp) break;
      tmp = next;
    }

    if (tmp.isObjCGCWeak())
      OS << "weak";
    else
      OS << "strong";
    OS << ')';
    break;
  }

  case AttributedType::attr_objc_ownership:
    OS << "objc_ownership(";
    switch (T->getEquivalentType().getObjCLifetime()) {
    case Qualifiers::OCL_None: llvm_unreachable("no ownership!");
    case Qualifiers::OCL_ExplicitNone: OS << "none"; break;
    case Qualifiers::OCL_Strong: OS << "strong"; break;
    case Qualifiers::OCL_Weak: OS << "weak"; break;
    case Qualifiers::OCL_Autoreleasing: OS << "autoreleasing"; break;
    }
    OS << ')';
    break;

  case AttributedType::attr_noreturn: OS << "noreturn"; break;
  case AttributedType::attr_cdecl: OS << "cdecl"; break;
  case AttributedType::attr_fastcall: OS << "fastcall"; break;
  case AttributedType::attr_stdcall: OS << "stdcall"; break;
  case AttributedType::attr_thiscall: OS << "thiscall"; break;
  case AttributedType::attr_pascal: OS << "pascal"; break;
  case AttributedType::attr_pcs: {
    OS << "pcs(";
   QualType t = T->getEquivalentType();
   while (!t->isFunctionType())
     t = t->getPointeeType();
   OS << (t->getAs<FunctionType>()->getCallConv() == CC_AAPCS ?
         "\"aapcs\"" : "\"aapcs-vfp\"");
   OS << ')';
   break;
  }
  case AttributedType::attr_pnaclcall: OS << "pnaclcall"; break;
  case AttributedType::attr_inteloclbicc: OS << "inteloclbicc"; break;
  }
  OS << "))";
}
Beispiel #28
0
SVal SimpleSValBuilder::evalBinOpLN(ProgramStateRef state,
                                  BinaryOperator::Opcode op,
                                  Loc lhs, NonLoc rhs, QualType resultTy) {
  if (op >= BO_PtrMemD && op <= BO_PtrMemI) {
    if (auto PTMSV = rhs.getAs<nonloc::PointerToMember>()) {
      if (PTMSV->isNullMemberPointer())
        return UndefinedVal();
      if (const FieldDecl *FD = PTMSV->getDeclAs<FieldDecl>()) {
        SVal Result = lhs;

        for (const auto &I : *PTMSV)
          Result = StateMgr.getStoreManager().evalDerivedToBase(
              Result, I->getType(),I->isVirtual());
        return state->getLValue(FD, Result);
      }
    }

    return rhs;
  }

  assert(!BinaryOperator::isComparisonOp(op) &&
         "arguments to comparison ops must be of the same type");

  // Special case: rhs is a zero constant.
  if (rhs.isZeroConstant())
    return lhs;

  // We are dealing with pointer arithmetic.

  // Handle pointer arithmetic on constant values.
  if (Optional<nonloc::ConcreteInt> rhsInt = rhs.getAs<nonloc::ConcreteInt>()) {
    if (Optional<loc::ConcreteInt> lhsInt = lhs.getAs<loc::ConcreteInt>()) {
      const llvm::APSInt &leftI = lhsInt->getValue();
      assert(leftI.isUnsigned());
      llvm::APSInt rightI(rhsInt->getValue(), /* isUnsigned */ true);

      // Convert the bitwidth of rightI.  This should deal with overflow
      // since we are dealing with concrete values.
      rightI = rightI.extOrTrunc(leftI.getBitWidth());

      // Offset the increment by the pointer size.
      llvm::APSInt Multiplicand(rightI.getBitWidth(), /* isUnsigned */ true);
      rightI *= Multiplicand;

      // Compute the adjusted pointer.
      switch (op) {
        case BO_Add:
          rightI = leftI + rightI;
          break;
        case BO_Sub:
          rightI = leftI - rightI;
          break;
        default:
          llvm_unreachable("Invalid pointer arithmetic operation");
      }
      return loc::ConcreteInt(getBasicValueFactory().getValue(rightI));
    }
  }

  // Handle cases where 'lhs' is a region.
  if (const MemRegion *region = lhs.getAsRegion()) {
    rhs = convertToArrayIndex(rhs).castAs<NonLoc>();
    SVal index = UnknownVal();
    const MemRegion *superR = nullptr;
    // We need to know the type of the pointer in order to add an integer to it.
    // Depending on the type, different amount of bytes is added.
    QualType elementType;

    if (const ElementRegion *elemReg = dyn_cast<ElementRegion>(region)) {
      assert(op == BO_Add || op == BO_Sub);
      index = evalBinOpNN(state, op, elemReg->getIndex(), rhs,
                          getArrayIndexType());
      superR = elemReg->getSuperRegion();
      elementType = elemReg->getElementType();
    }
    else if (isa<SubRegion>(region)) {
      assert(op == BO_Add || op == BO_Sub);
      index = (op == BO_Add) ? rhs : evalMinus(rhs);
      superR = region;
      // TODO: Is this actually reliable? Maybe improving our MemRegion
      // hierarchy to provide typed regions for all non-void pointers would be
      // better. For instance, we cannot extend this towards LocAsInteger
      // operations, where result type of the expression is integer.
      if (resultTy->isAnyPointerType())
        elementType = resultTy->getPointeeType();
    }

    if (Optional<NonLoc> indexV = index.getAs<NonLoc>()) {
      return loc::MemRegionVal(MemMgr.getElementRegion(elementType, *indexV,
                                                       superR, getContext()));
    }
  }
  return UnknownVal();
}
Beispiel #29
0
/// \brief Figure out if an expression could be turned into a call.
///
/// Use this when trying to recover from an error where the programmer may have
/// written just the name of a function instead of actually calling it.
///
/// \param E - The expression to examine.
/// \param ZeroArgCallReturnTy - If the expression can be turned into a call
///  with no arguments, this parameter is set to the type returned by such a
///  call; otherwise, it is set to an empty QualType.
/// \param OverloadSet - If the expression is an overloaded function
///  name, this parameter is populated with the decls of the various overloads.
bool Sema::isExprCallable(const Expr &E, QualType &ZeroArgCallReturnTy,
                          UnresolvedSetImpl &OverloadSet) {
  ZeroArgCallReturnTy = QualType();
  OverloadSet.clear();

  if (E.getType() == Context.OverloadTy) {
    OverloadExpr::FindResult FR = OverloadExpr::find(const_cast<Expr*>(&E));
    const OverloadExpr *Overloads = FR.Expression;

    for (OverloadExpr::decls_iterator it = Overloads->decls_begin(),
         DeclsEnd = Overloads->decls_end(); it != DeclsEnd; ++it) {
      OverloadSet.addDecl(*it);

      // Check whether the function is a non-template which takes no
      // arguments.
      if (const FunctionDecl *OverloadDecl
            = dyn_cast<FunctionDecl>((*it)->getUnderlyingDecl())) {
        if (OverloadDecl->getMinRequiredArguments() == 0)
          ZeroArgCallReturnTy = OverloadDecl->getResultType();
      }
    }

    // Ignore overloads that are pointer-to-member constants.
    if (FR.HasFormOfMemberPointer)
      return false;

    return true;
  }

  if (const DeclRefExpr *DeclRef = dyn_cast<DeclRefExpr>(E.IgnoreParens())) {
    if (const FunctionDecl *Fun = dyn_cast<FunctionDecl>(DeclRef->getDecl())) {
      if (Fun->getMinRequiredArguments() == 0)
        ZeroArgCallReturnTy = Fun->getResultType();
      return true;
    }
  }

  // We don't have an expression that's convenient to get a FunctionDecl from,
  // but we can at least check if the type is "function of 0 arguments".
  QualType ExprTy = E.getType();
  const FunctionType *FunTy = NULL;
  QualType PointeeTy = ExprTy->getPointeeType();
  if (!PointeeTy.isNull())
    FunTy = PointeeTy->getAs<FunctionType>();
  if (!FunTy)
    FunTy = ExprTy->getAs<FunctionType>();
  if (!FunTy && ExprTy == Context.BoundMemberTy) {
    // Look for the bound-member type.  If it's still overloaded, give up,
    // although we probably should have fallen into the OverloadExpr case above
    // if we actually have an overloaded bound member.
    QualType BoundMemberTy = Expr::findBoundMemberType(&E);
    if (!BoundMemberTy.isNull())
      FunTy = BoundMemberTy->castAs<FunctionType>();
  }

  if (const FunctionProtoType *FPT =
      dyn_cast_or_null<FunctionProtoType>(FunTy)) {
    if (FPT->getNumArgs() == 0)
      ZeroArgCallReturnTy = FunTy->getResultType();
    return true;
  }
  return false;
}
/// \brief The LoopFixer callback, which determines if loops discovered by the
/// matchers are convertible, printing information about the loops if so.
void LoopFixer::run(const MatchFinder::MatchResult &Result) {
  const BoundNodes &Nodes = Result.Nodes;
  Confidence ConfidenceLevel(RL_Safe);
  ASTContext *Context = Result.Context;
  const ForStmt *TheLoop = Nodes.getStmtAs<ForStmt>(LoopName);

  if (!Owner.isFileModifiable(Context->getSourceManager(),TheLoop->getForLoc()))
    return;

  // Check that we have exactly one index variable and at most one end variable.
  const VarDecl *LoopVar = Nodes.getDeclAs<VarDecl>(IncrementVarName);
  const VarDecl *CondVar = Nodes.getDeclAs<VarDecl>(ConditionVarName);
  const VarDecl *InitVar = Nodes.getDeclAs<VarDecl>(InitVarName);
  if (!areSameVariable(LoopVar, CondVar) || !areSameVariable(LoopVar, InitVar))
    return;
  const VarDecl *EndVar = Nodes.getDeclAs<VarDecl>(EndVarName);
  const VarDecl *ConditionEndVar =
      Nodes.getDeclAs<VarDecl>(ConditionEndVarName);
  if (EndVar && !areSameVariable(EndVar, ConditionEndVar))
    return;

  // If the end comparison isn't a variable, we can try to work with the
  // expression the loop variable is being tested against instead.
  const CXXMemberCallExpr *EndCall =
      Nodes.getStmtAs<CXXMemberCallExpr>(EndCallName);
  const Expr *BoundExpr = Nodes.getStmtAs<Expr>(ConditionBoundName);
  // If the loop calls end()/size() after each iteration, lower our confidence
  // level.
  if (FixerKind != LFK_Array && !EndVar)
    ConfidenceLevel.lowerTo(RL_Reasonable);

  const Expr *ContainerExpr = nullptr;
  bool DerefByValue = false;
  bool DerefByConstRef = false;
  bool ContainerNeedsDereference = false;
  // FIXME: Try to put most of this logic inside a matcher. Currently, matchers
  // don't allow the right-recursive checks in digThroughConstructors.
  if (FixerKind == LFK_Iterator) {
    ContainerExpr = findContainer(Context, LoopVar->getInit(),
                                  EndVar ? EndVar->getInit() : EndCall,
                                  &ContainerNeedsDereference);

    QualType InitVarType = InitVar->getType();
    QualType CanonicalInitVarType = InitVarType.getCanonicalType();

    const CXXMemberCallExpr *BeginCall =
        Nodes.getNodeAs<CXXMemberCallExpr>(BeginCallName);
    assert(BeginCall && "Bad Callback. No begin call expression.");
    QualType CanonicalBeginType =
        BeginCall->getMethodDecl()->getReturnType().getCanonicalType();

    if (CanonicalBeginType->isPointerType() &&
        CanonicalInitVarType->isPointerType()) {
      QualType BeginPointeeType = CanonicalBeginType->getPointeeType();
      QualType InitPointeeType = CanonicalInitVarType->getPointeeType();
      // If the initializer and the variable are both pointers check if the
      // un-qualified pointee types match otherwise we don't use auto.
      if (!Context->hasSameUnqualifiedType(InitPointeeType, BeginPointeeType))
        return;
    } else {
      // Check for qualified types to avoid conversions from non-const to const
      // iterator types.
      if (!Context->hasSameType(CanonicalInitVarType, CanonicalBeginType))
        return;
    }

    DerefByValue = Nodes.getNodeAs<QualType>(DerefByValueResultName) != nullptr;
    if (!DerefByValue) {
      if (const QualType *DerefType =
              Nodes.getNodeAs<QualType>(DerefByRefResultName)) {
        // A node will only be bound with DerefByRefResultName if we're dealing
        // with a user-defined iterator type. Test the const qualification of
        // the reference type.
        DerefByConstRef = (*DerefType)->getAs<ReferenceType>()->getPointeeType()
            .isConstQualified();
      } else {
        // By nature of the matcher this case is triggered only for built-in
        // iterator types (i.e. pointers).
        assert(isa<PointerType>(CanonicalInitVarType) &&
               "Non-class iterator type is not a pointer type");
        QualType InitPointeeType = CanonicalInitVarType->getPointeeType();
        QualType BeginPointeeType = CanonicalBeginType->getPointeeType();
        // If the initializer and variable have both the same type just use auto
        // otherwise we test for const qualification of the pointed-at type.
        if (!Context->hasSameType(InitPointeeType, BeginPointeeType))
          DerefByConstRef = InitPointeeType.isConstQualified();
      }
    } else {
      // If the dereference operator returns by value then test for the
      // canonical const qualification of the init variable type.
      DerefByConstRef = CanonicalInitVarType.isConstQualified();
    }
  } else if (FixerKind == LFK_PseudoArray) {
    if (!EndCall)
      return;
    ContainerExpr = EndCall->getImplicitObjectArgument();
    const MemberExpr *Member = dyn_cast<MemberExpr>(EndCall->getCallee());
    if (!Member)
      return;
    ContainerNeedsDereference = Member->isArrow();
  }
  // We must know the container or an array length bound.
  if (!ContainerExpr && !BoundExpr)
    return;

  findAndVerifyUsages(Context, LoopVar, EndVar, ContainerExpr, BoundExpr,
                      ContainerNeedsDereference, DerefByValue, DerefByConstRef,
                      TheLoop, ConfidenceLevel);
}