C++ ASTContext::getTypeSizeInChars方法代码示例

static void fillInlineAsmTypeInfo(const ASTContext &Context, QualType T,
                                  llvm::InlineAsmIdentifierInfo &Info) {
  // Compute the type size (and array length if applicable?).
  Info.Type = Info.Size = Context.getTypeSizeInChars(T).getQuantity();
  if (T->isArrayType()) {
    const ArrayType *ATy = Context.getAsArrayType(T);
    Info.Type = Context.getTypeSizeInChars(ATy->getElementType()).getQuantity();
    Info.Length = Info.Size / Info.Type;
  }
}

/// Check if we are casting to a struct with a flexible array at the end.
/// \code
/// struct foo {
///   size_t len;
///   struct bar data[];
/// };
/// \endcode
/// or
/// \code
/// struct foo {
///   size_t len;
///   struct bar data[0];
/// }
/// \endcode
/// In these cases it is also valid to allocate size of struct foo + a multiple
/// of struct bar.
static bool evenFlexibleArraySize(ASTContext &Ctx, CharUnits RegionSize,
                                  CharUnits TypeSize, QualType ToPointeeTy) {
  const RecordType *RT = ToPointeeTy->getAs<RecordType>();
  if (!RT)
    return false;

  const RecordDecl *RD = RT->getDecl();
  RecordDecl::field_iterator Iter(RD->field_begin());
  RecordDecl::field_iterator End(RD->field_end());
  const FieldDecl *Last = 0;
  for (; Iter != End; ++Iter)
    Last = *Iter;
  assert(Last && "empty structs should already be handled");

  const Type *ElemType = Last->getType()->getArrayElementTypeNoTypeQual();
  CharUnits FlexSize;
  if (const ConstantArrayType *ArrayTy =
        Ctx.getAsConstantArrayType(Last->getType())) {
    FlexSize = Ctx.getTypeSizeInChars(ElemType);
    if (ArrayTy->getSize() == 1 && TypeSize > FlexSize)
      TypeSize -= FlexSize;
    else if (ArrayTy->getSize() != 0)
      return false;
  } else if (RD->hasFlexibleArrayMember()) {
    FlexSize = Ctx.getTypeSizeInChars(ElemType);
  } else {
    return false;
  }

  if (FlexSize.isZero())
    return false;

  CharUnits Left = RegionSize - TypeSize;
  if (Left.isNegative())
    return false;

  if (Left % FlexSize == 0)
    return true;

  return false;
}

void APValue::printPretty(raw_ostream &Out, ASTContext &Ctx, QualType Ty) const{
  switch (getKind()) {
  case APValue::Uninitialized:
    Out << "<uninitialized>";
    return;
  case APValue::Int:
    if (Ty->isBooleanType())
      Out << (getInt().getBoolValue() ? "true" : "false");
    else
      Out << getInt();
    return;
  case APValue::Float:
    Out << GetApproxValue(getFloat());
    return;
  case APValue::Vector: {
    Out << '{';
    QualType ElemTy = Ty->getAs<VectorType>()->getElementType();
    getVectorElt(0).printPretty(Out, Ctx, ElemTy);
    for (unsigned i = 1; i != getVectorLength(); ++i) {
      Out << ", ";
      getVectorElt(i).printPretty(Out, Ctx, ElemTy);
    }
    Out << '}';
    return;
  }
  case APValue::ComplexInt:
    Out << getComplexIntReal() << "+" << getComplexIntImag() << "i";
    return;
  case APValue::ComplexFloat:
    Out << GetApproxValue(getComplexFloatReal()) << "+"
        << GetApproxValue(getComplexFloatImag()) << "i";
    return;
  case APValue::LValue: {
    LValueBase Base = getLValueBase();
    if (!Base) {
      Out << "0";
      return;
    }

    bool IsReference = Ty->isReferenceType();
    QualType InnerTy
      = IsReference ? Ty.getNonReferenceType() : Ty->getPointeeType();
    if (InnerTy.isNull())
      InnerTy = Ty;

    if (!hasLValuePath()) {
      // No lvalue path: just print the offset.
      CharUnits O = getLValueOffset();
      CharUnits S = Ctx.getTypeSizeInChars(InnerTy);
      if (!O.isZero()) {
        if (IsReference)
          Out << "*(";
        if (O % S) {
          Out << "(char*)";
          S = CharUnits::One();
        }
        Out << '&';
      } else if (!IsReference)
        Out << '&';

      if (const ValueDecl *VD = Base.dyn_cast<const ValueDecl*>())
        Out << *VD;
      else {
        assert(Base.get<const Expr *>() != nullptr &&
               "Expecting non-null Expr");
        Base.get<const Expr*>()->printPretty(Out, nullptr,
                                             Ctx.getPrintingPolicy());
      }

      if (!O.isZero()) {
        Out << " + " << (O / S);
        if (IsReference)
          Out << ')';
      }
      return;
    }

    // We have an lvalue path. Print it out nicely.
    if (!IsReference)
      Out << '&';
    else if (isLValueOnePastTheEnd())
      Out << "*(&";

    QualType ElemTy;
    if (const ValueDecl *VD = Base.dyn_cast<const ValueDecl*>()) {
      Out << *VD;
      ElemTy = VD->getType();
    } else {
      const Expr *E = Base.get<const Expr*>();
      assert(E != nullptr && "Expecting non-null Expr");
      E->printPretty(Out, nullptr, Ctx.getPrintingPolicy());
      ElemTy = E->getType();
    }

    ArrayRef<LValuePathEntry> Path = getLValuePath();
    const CXXRecordDecl *CastToBase = nullptr;
    for (unsigned I = 0, N = Path.size(); I != N; ++I) {
      if (ElemTy->getAs<RecordType>()) {
        // The lvalue refers to a class type, so the next path entry is a base
        // or member.
//.........这里部分代码省略.........