Exemple #1
0
/// TryStaticMemberPointerUpcast - Tests whether a conversion according to
/// C++ 5.2.9p9 is valid:
///
///   An rvalue of type "pointer to member of D of type cv1 T" can be
///   converted to an rvalue of type "pointer to member of B of type cv2 T",
///   where B is a base class of D [...].
///
TryCastResult
TryStaticMemberPointerUpcast(Sema &Self, QualType SrcType, QualType DestType,
                             bool CStyle, const SourceRange &OpRange,
                             unsigned &msg)
{
  const MemberPointerType *DestMemPtr = DestType->getAs<MemberPointerType>();
  if (!DestMemPtr)
    return TC_NotApplicable;
  const MemberPointerType *SrcMemPtr = SrcType->getAs<MemberPointerType>();
  if (!SrcMemPtr) {
    msg = diag::err_bad_static_cast_member_pointer_nonmp;
    return TC_NotApplicable;
  }

  // T == T, modulo cv
  if (Self.Context.getCanonicalType(
        SrcMemPtr->getPointeeType().getUnqualifiedType()) !=
      Self.Context.getCanonicalType(DestMemPtr->getPointeeType().
                                    getUnqualifiedType()))
    return TC_NotApplicable;

  // B base of D
  QualType SrcClass(SrcMemPtr->getClass(), 0);
  QualType DestClass(DestMemPtr->getClass(), 0);
  BasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/!CStyle,
                  /*DetectVirtual=*/true);
  if (!Self.IsDerivedFrom(SrcClass, DestClass, Paths)) {
    return TC_NotApplicable;
  }

  // B is a base of D. But is it an allowed base? If not, it's a hard error.
  if (Paths.isAmbiguous(DestClass)) {
    Paths.clear();
    Paths.setRecordingPaths(true);
    bool StillOkay = Self.IsDerivedFrom(SrcClass, DestClass, Paths);
    assert(StillOkay);
    StillOkay = StillOkay;
    std::string PathDisplayStr = Self.getAmbiguousPathsDisplayString(Paths);
    Self.Diag(OpRange.getBegin(), diag::err_ambiguous_memptr_conv)
      << 1 << SrcClass << DestClass << PathDisplayStr << OpRange;
    msg = 0;
    return TC_Failed;
  }

  if (const RecordType *VBase = Paths.getDetectedVirtual()) {
    Self.Diag(OpRange.getBegin(), diag::err_memptr_conv_via_virtual)
      << SrcClass << DestClass << QualType(VBase, 0) << OpRange;
    msg = 0;
    return TC_Failed;
  }

  if (!CStyle && Self.CheckBaseClassAccess(DestType, SrcType,
                          diag::err_downcast_from_inaccessible_base, Paths,
                          OpRange.getBegin(), DeclarationName())) {
    msg = 0;
    return TC_Failed;
  }

  return TC_Success;
}
/// TryStaticMemberPointerUpcast - Tests whether a conversion according to
/// C++ 5.2.9p9 is valid:
///
///   An rvalue of type "pointer to member of D of type cv1 T" can be
///   converted to an rvalue of type "pointer to member of B of type cv2 T",
///   where B is a base class of D [...].
///
TryStaticCastResult
TryStaticMemberPointerUpcast(Sema &Self, QualType SrcType, QualType DestType,
                             const SourceRange &OpRange)
{
  const MemberPointerType *SrcMemPtr = SrcType->getAsMemberPointerType();
  if (!SrcMemPtr)
    return TSC_NotApplicable;
  const MemberPointerType *DestMemPtr = DestType->getAsMemberPointerType();
  if (!DestMemPtr)
    return TSC_NotApplicable;

  // T == T, modulo cv
  if (Self.Context.getCanonicalType(
        SrcMemPtr->getPointeeType().getUnqualifiedType()) !=
      Self.Context.getCanonicalType(DestMemPtr->getPointeeType().
                                    getUnqualifiedType()))
    return TSC_NotApplicable;

  // B base of D
  QualType SrcClass(SrcMemPtr->getClass(), 0);
  QualType DestClass(DestMemPtr->getClass(), 0);
  BasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/false,
                  /*DetectVirtual=*/true);
  if (!Self.IsDerivedFrom(SrcClass, DestClass, Paths)) {
    return TSC_NotApplicable;
  }

  // B is a base of D. But is it an allowed base? If not, it's a hard error.
  if (Paths.isAmbiguous(DestClass)) {
    Paths.clear();
    Paths.setRecordingPaths(true);
    bool StillOkay = Self.IsDerivedFrom(SrcClass, DestClass, Paths);
    assert(StillOkay);
    StillOkay = StillOkay;
    std::string PathDisplayStr = Self.getAmbiguousPathsDisplayString(Paths);
    Self.Diag(OpRange.getBegin(), diag::err_ambiguous_memptr_conv)
      << 1 << SrcClass << DestClass << PathDisplayStr << OpRange;
    return TSC_Failed;
  }

  if (const RecordType *VBase = Paths.getDetectedVirtual()) {
    Self.Diag(OpRange.getBegin(), diag::err_memptr_conv_via_virtual)
      << SrcClass << DestClass << QualType(VBase, 0) << OpRange;
    return TSC_Failed;
  }

  // FIXME: Test accessibility.

  return TSC_Success;
}