C++ (Cpp) Sema::PerformObjectMemberConversion Examples

Example #1

File: SemaExprMember.cpp Project: nico/gong

static ExprResult
BuildFieldReferenceExpr(Sema &S, Expr *BaseExpr, bool IsArrow,
                        const CXXScopeSpec &SS, FieldDecl *Field,
                        DeclAccessPair FoundDecl,
                        const DeclarationNameInfo &MemberNameInfo) {
  // x.a is an l-value if 'a' has a reference type. Otherwise:
  // x.a is an l-value/x-value/pr-value if the base is (and note
  //   that *x is always an l-value), except that if the base isn't
  //   an ordinary object then we must have an rvalue.
  ExprValueKind VK = VK_LValue;
  ExprObjectKind OK = OK_Ordinary;
  if (!IsArrow) {
    if (BaseExpr->getObjectKind() == OK_Ordinary)
      VK = BaseExpr->getValueKind();
    else
      VK = VK_RValue;
  }
  if (VK != VK_RValue && Field->isBitField())
    OK = OK_BitField;
  
  // Figure out the type of the member; see C99 6.5.2.3p3, C++ [expr.ref]
  QualType MemberType = Field->getType();
  if (const ReferenceType *Ref = MemberType->getAs<ReferenceType>()) {
    MemberType = Ref->getPointeeType();
    VK = VK_LValue;
  } else {
    QualType BaseType = BaseExpr->getType();
    if (IsArrow) BaseType = BaseType->getAs<PointerType>()->getPointeeType();

    Qualifiers BaseQuals = BaseType.getQualifiers();

    // CVR attributes from the base are picked up by members,
    // except that 'mutable' members don't pick up 'const'.
    if (Field->isMutable()) BaseQuals.removeConst();

    Qualifiers MemberQuals
    = S.Context.getCanonicalType(MemberType).getQualifiers();

    assert(!MemberQuals.hasAddressSpace());


    Qualifiers Combined = BaseQuals + MemberQuals;
    if (Combined != MemberQuals)
      MemberType = S.Context.getQualifiedType(MemberType, Combined);
  }

  S.UnusedPrivateFields.remove(Field);

  ExprResult Base =
  S.PerformObjectMemberConversion(BaseExpr, SS.getScopeRep(),
                                  FoundDecl, Field);
  if (Base.isInvalid())
    return ExprError();
  return S.Owned(BuildMemberExpr(S, S.Context, Base.take(), IsArrow,
                                 Field, FoundDecl, MemberNameInfo,
                                 MemberType, VK, OK));
}