C++ QualType::getUnqualifiedType方法代码示例

static bool pointedUnqualifiedTypesAreEqual(QualType T1, QualType T2) {
  while ((T1->isPointerType() && T2->isPointerType()) ||
         (T1->isReferenceType() && T2->isReferenceType())) {
    T1 = T1->getPointeeType();
    T2 = T2->getPointeeType();
  }
  return T1.getUnqualifiedType() == T2.getUnqualifiedType();
}

bool pointedTypesAreEqual(QualType SourceType, QualType DestType) {
  SourceType = SourceType.getNonReferenceType();
  DestType = DestType.getNonReferenceType();
  while (SourceType->isPointerType() && DestType->isPointerType()) {
    SourceType = SourceType->getPointeeType();
    DestType = DestType->getPointeeType();
  }
  return SourceType.getUnqualifiedType() == DestType.getUnqualifiedType();
}

CXType cxtype::MakeCXType(QualType T, CXTranslationUnit TU) {
  CXTypeKind TK = CXType_Invalid;

  if (TU && !T.isNull()) {
    // Handle attributed types as the original type
    if (auto *ATT = T->getAs<AttributedType>()) {
      return MakeCXType(ATT->getModifiedType(), TU);
    }

    ASTContext &Ctx = cxtu::getASTUnit(TU)->getASTContext();
    if (Ctx.getLangOpts().ObjC1) {
      QualType UnqualT = T.getUnqualifiedType();
      if (Ctx.isObjCIdType(UnqualT))
        TK = CXType_ObjCId;
      else if (Ctx.isObjCClassType(UnqualT))
        TK = CXType_ObjCClass;
      else if (Ctx.isObjCSelType(UnqualT))
        TK = CXType_ObjCSel;
    }

    /* Handle decayed types as the original type */
    if (const DecayedType *DT = T->getAs<DecayedType>()) {
      return MakeCXType(DT->getOriginalType(), TU);
    }
  }
  if (TK == CXType_Invalid)
    TK = GetTypeKind(T);

  CXType CT = { TK, { TK == CXType_Invalid ? nullptr
                                           : T.getAsOpaquePtr(), TU } };
  return CT;
}

void CXXRecordDecl::addedAssignmentOperator(ASTContext &Context,
                                            CXXMethodDecl *OpDecl) {
  // We're interested specifically in copy assignment operators.
  // Unlike addedConstructor, this method is not called for implicit
  // declarations.
  const FunctionProtoType *FnType = OpDecl->getType()->getAsFunctionProtoType();
  assert(FnType && "Overloaded operator has no proto function type.");
  assert(FnType->getNumArgs() == 1 && !FnType->isVariadic());
  QualType ArgType = FnType->getArgType(0);
  if (const LValueReferenceType *Ref = ArgType->getAsLValueReferenceType())
    ArgType = Ref->getPointeeType();

  ArgType = ArgType.getUnqualifiedType();
  QualType ClassType = Context.getCanonicalType(Context.getTypeDeclType(
    const_cast<CXXRecordDecl*>(this)));

  if (ClassType != Context.getCanonicalType(ArgType))
    return;

  // This is a copy assignment operator.
  // Suppress the implicit declaration of a copy constructor.
  UserDeclaredCopyAssignment = true;

  // C++ [class]p4:
  //   A POD-struct is an aggregate class that [...] has no user-defined copy
  //   assignment operator [...].
  PlainOldData = false;
}

bool 
CXXConstructorDecl::isCopyConstructor(ASTContext &Context, 
                                      unsigned &TypeQuals) const {
  // C++ [class.copy]p2:
  //   A non-template constructor for class X is a copy constructor
  //   if its first parameter is of type X&, const X&, volatile X& or
  //   const volatile X&, and either there are no other parameters
  //   or else all other parameters have default arguments (8.3.6).
  if ((getNumParams() < 1) ||
      (getNumParams() > 1 && getParamDecl(1)->getDefaultArg() == 0))
    return false;

  const ParmVarDecl *Param = getParamDecl(0);

  // Do we have a reference type? Rvalue references don't count.
  const LValueReferenceType *ParamRefType =
    Param->getType()->getAsLValueReferenceType();
  if (!ParamRefType)
    return false;

  // Is it a reference to our class type?
  QualType PointeeType 
    = Context.getCanonicalType(ParamRefType->getPointeeType());
  QualType ClassTy 
    = Context.getTagDeclType(const_cast<CXXRecordDecl*>(getParent()));
  if (PointeeType.getUnqualifiedType() != ClassTy)
    return false;

  // We have a copy constructor.
  TypeQuals = PointeeType.getCVRQualifiers();
  return true;
}

static bool rewriteToObjCProperty(const ObjCMethodDecl *Getter,
                                  const ObjCMethodDecl *Setter,
                                  const NSAPI &NS, edit::Commit &commit) {
  ASTContext &Context = NS.getASTContext();
  std::string PropertyString = "@property";
  const ParmVarDecl *argDecl = *Setter->param_begin();
  QualType ArgType = Context.getCanonicalType(argDecl->getType());
  Qualifiers::ObjCLifetime propertyLifetime = ArgType.getObjCLifetime();
  
  if (ArgType->isObjCRetainableType() &&
      propertyLifetime == Qualifiers::OCL_Strong) {
    if (const ObjCObjectPointerType *ObjPtrTy =
        ArgType->getAs<ObjCObjectPointerType>()) {
      ObjCInterfaceDecl *IDecl = ObjPtrTy->getObjectType()->getInterface();
      if (IDecl &&
          IDecl->lookupNestedProtocol(&Context.Idents.get("NSCopying")))
        PropertyString += "(copy)";
    }
  }
  else if (propertyLifetime == Qualifiers::OCL_Weak)
    // TODO. More precise determination of 'weak' attribute requires
    // looking into setter's implementation for backing weak ivar.
    PropertyString += "(weak)";
  else
    PropertyString += "(unsafe_unretained)";
  
  // strip off any ARC lifetime qualifier.
  QualType CanResultTy = Context.getCanonicalType(Getter->getResultType());
  if (CanResultTy.getQualifiers().hasObjCLifetime()) {
    Qualifiers Qs = CanResultTy.getQualifiers();
    Qs.removeObjCLifetime();
    CanResultTy = Context.getQualifiedType(CanResultTy.getUnqualifiedType(), Qs);
  }
  PropertyString += " ";
  PropertyString += CanResultTy.getAsString(Context.getPrintingPolicy());
  PropertyString += " ";
  PropertyString += Getter->getNameAsString();
  commit.replace(CharSourceRange::getCharRange(Getter->getLocStart(),
                                               Getter->getDeclaratorEndLoc()),
                 PropertyString);
  SourceLocation EndLoc = Setter->getDeclaratorEndLoc();
  // Get location past ';'
  EndLoc = EndLoc.getLocWithOffset(1);
  commit.remove(CharSourceRange::getCharRange(Setter->getLocStart(), EndLoc));
  return true;
}

CXXConstructorDecl *
CXXRecordDecl::getDefaultConstructor(ASTContext &Context) {
  QualType ClassType = Context.getTypeDeclType(this);
  DeclarationName ConstructorName
    = Context.DeclarationNames.getCXXConstructorName(
                      Context.getCanonicalType(ClassType.getUnqualifiedType()));

  DeclContext::lookup_const_iterator Con, ConEnd;
  for (llvm::tie(Con, ConEnd) = lookup(ConstructorName);
       Con != ConEnd; ++Con) {
    // FIXME: In C++0x, a constructor template can be a default constructor.
    if (isa<FunctionTemplateDecl>(*Con))
      continue;

    CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(*Con);
    if (Constructor->isDefaultConstructor())
      return Constructor;
  }
  return 0;
}

void CXXRecordDecl::addedAssignmentOperator(ASTContext &Context,
                                            CXXMethodDecl *OpDecl) {
  // We're interested specifically in copy assignment operators.
  const FunctionProtoType *FnType = OpDecl->getType()->getAs<FunctionProtoType>();
  assert(FnType && "Overloaded operator has no proto function type.");
  assert(FnType->getNumArgs() == 1 && !FnType->isVariadic());
  
  // Copy assignment operators must be non-templates.
  if (OpDecl->getPrimaryTemplate() || OpDecl->getDescribedFunctionTemplate())
    return;
  
  QualType ArgType = FnType->getArgType(0);
  if (const LValueReferenceType *Ref = ArgType->getAs<LValueReferenceType>())
    ArgType = Ref->getPointeeType();

  ArgType = ArgType.getUnqualifiedType();
  QualType ClassType = Context.getCanonicalType(Context.getTypeDeclType(
    const_cast<CXXRecordDecl*>(this)));

  if (!Context.hasSameUnqualifiedType(ClassType, ArgType))
    return;

  // This is a copy assignment operator.
  // Note on the decl that it is a copy assignment operator.
  OpDecl->setCopyAssignment(true);

  // Suppress the implicit declaration of a copy constructor.
  data().UserDeclaredCopyAssignment = true;
  data().DeclaredCopyAssignment = true;
  
  // C++ [class.copy]p11:
  //   A copy assignment operator is trivial if it is implicitly declared.
  // FIXME: C++0x: don't do this for "= default" copy operators.
  data().HasTrivialCopyAssignment = false;

  // C++ [class]p4:
  //   A POD-struct is an aggregate class that [...] has no user-defined copy
  //   assignment operator [...].
  data().PlainOldData = false;
}

/// PerformImplicitConversion - Perform an implicit conversion of the
/// expression From to the type ToType by following the standard
/// conversion sequence SCS. Returns true if there was an error, false
/// otherwise. The expression From is replaced with the converted
/// expression. Flavor is the context in which we're performing this
/// conversion, for use in error messages.
bool 
Sema::PerformImplicitConversion(Expr *&From, QualType ToType,
                                const StandardConversionSequence& SCS,
                                const char *Flavor) {
  // Overall FIXME: we are recomputing too many types here and doing
  // far too much extra work. What this means is that we need to keep
  // track of more information that is computed when we try the
  // implicit conversion initially, so that we don't need to recompute
  // anything here.
  QualType FromType = From->getType();

  if (SCS.CopyConstructor) {
    // FIXME: Create a temporary object by calling the copy
    // constructor.
    ImpCastExprToType(From, ToType.getNonReferenceType(), 
                      ToType->isLValueReferenceType());
    return false;
  }

  // Perform the first implicit conversion.
  switch (SCS.First) {
  case ICK_Identity:
  case ICK_Lvalue_To_Rvalue:
    // Nothing to do.
    break;

  case ICK_Array_To_Pointer:
    FromType = Context.getArrayDecayedType(FromType);
    ImpCastExprToType(From, FromType);
    break;

  case ICK_Function_To_Pointer:
    if (Context.getCanonicalType(FromType) == Context.OverloadTy) {
      FunctionDecl *Fn = ResolveAddressOfOverloadedFunction(From, ToType, true);
      if (!Fn)
        return true;

      if (DiagnoseUseOfDecl(Fn, From->getSourceRange().getBegin()))
        return true;

      FixOverloadedFunctionReference(From, Fn);
      FromType = From->getType();
    }
    FromType = Context.getPointerType(FromType);
    ImpCastExprToType(From, FromType);
    break;

  default:
    assert(false && "Improper first standard conversion");
    break;
  }

  // Perform the second implicit conversion
  switch (SCS.Second) {
  case ICK_Identity:
    // Nothing to do.
    break;

  case ICK_Integral_Promotion:
  case ICK_Floating_Promotion:
  case ICK_Complex_Promotion:
  case ICK_Integral_Conversion:
  case ICK_Floating_Conversion:
  case ICK_Complex_Conversion:
  case ICK_Floating_Integral:
  case ICK_Complex_Real:
  case ICK_Compatible_Conversion:
      // FIXME: Go deeper to get the unqualified type!
    FromType = ToType.getUnqualifiedType();
    ImpCastExprToType(From, FromType);
    break;

  case ICK_Pointer_Conversion:
    if (SCS.IncompatibleObjC) {
      // Diagnose incompatible Objective-C conversions
      Diag(From->getSourceRange().getBegin(), 
           diag::ext_typecheck_convert_incompatible_pointer)
        << From->getType() << ToType << Flavor
        << From->getSourceRange();
    }

    if (CheckPointerConversion(From, ToType))
      return true;
    ImpCastExprToType(From, ToType);
    break;

  case ICK_Pointer_Member:
    if (CheckMemberPointerConversion(From, ToType))
      return true;
    ImpCastExprToType(From, ToType);
    break;

  case ICK_Boolean_Conversion:
    FromType = Context.BoolTy;
//.........这里部分代码省略.........

/// TryConstCast - See if a const_cast from source to destination is allowed,
/// and perform it if it is.
static TryCastResult TryConstCast(Sema &Self, Expr *SrcExpr, QualType DestType,
                                  bool CStyle, unsigned &msg) {
  DestType = Self.Context.getCanonicalType(DestType);
  QualType SrcType = SrcExpr->getType();
  if (const LValueReferenceType *DestTypeTmp =
        DestType->getAs<LValueReferenceType>()) {
    if (SrcExpr->isLvalue(Self.Context) != Expr::LV_Valid) {
      // Cannot const_cast non-lvalue to lvalue reference type. But if this
      // is C-style, static_cast might find a way, so we simply suggest a
      // message and tell the parent to keep searching.
      msg = diag::err_bad_cxx_cast_rvalue;
      return TC_NotApplicable;
    }

    // C++ 5.2.11p4: An lvalue of type T1 can be [cast] to an lvalue of type T2
    //   [...] if a pointer to T1 can be [cast] to the type pointer to T2.
    DestType = Self.Context.getPointerType(DestTypeTmp->getPointeeType());
    SrcType = Self.Context.getPointerType(SrcType);
  }

  // C++ 5.2.11p5: For a const_cast involving pointers to data members [...]
  //   the rules for const_cast are the same as those used for pointers.

  if (!DestType->isPointerType() && !DestType->isMemberPointerType()) {
    // Cannot cast to non-pointer, non-reference type. Note that, if DestType
    // was a reference type, we converted it to a pointer above.
    // The status of rvalue references isn't entirely clear, but it looks like
    // conversion to them is simply invalid.
    // C++ 5.2.11p3: For two pointer types [...]
    if (!CStyle)
      msg = diag::err_bad_const_cast_dest;
    return TC_NotApplicable;
  }
  if (DestType->isFunctionPointerType() ||
      DestType->isMemberFunctionPointerType()) {
    // Cannot cast direct function pointers.
    // C++ 5.2.11p2: [...] where T is any object type or the void type [...]
    // T is the ultimate pointee of source and target type.
    if (!CStyle)
      msg = diag::err_bad_const_cast_dest;
    return TC_NotApplicable;
  }
  SrcType = Self.Context.getCanonicalType(SrcType);

  // Unwrap the pointers. Ignore qualifiers. Terminate early if the types are
  // completely equal.
  // FIXME: const_cast should probably not be able to convert between pointers
  // to different address spaces.
  // C++ 5.2.11p3 describes the core semantics of const_cast. All cv specifiers
  // in multi-level pointers may change, but the level count must be the same,
  // as must be the final pointee type.
  while (SrcType != DestType &&
         Self.UnwrapSimilarPointerTypes(SrcType, DestType)) {
    SrcType = SrcType.getUnqualifiedType();
    DestType = DestType.getUnqualifiedType();
  }

  // Since we're dealing in canonical types, the remainder must be the same.
  if (SrcType != DestType)
    return TC_NotApplicable;

  return TC_Success;
}

void CodeGenFunction::ExitCXXTryStmt(const CXXTryStmt &S,
                                     CXXTryStmtInfo TryInfo) {
  // Pointer to the personality function
  llvm::Constant *Personality =
    CGM.CreateRuntimeFunction(llvm::FunctionType::get(llvm::Type::getInt32Ty
                                                      (VMContext),
                                                      true),
                              "__gxx_personality_v0");
  Personality = llvm::ConstantExpr::getBitCast(Personality, PtrToInt8Ty);
  llvm::Value *llvm_eh_exception =
    CGM.getIntrinsic(llvm::Intrinsic::eh_exception);
  llvm::Value *llvm_eh_selector =
    CGM.getIntrinsic(llvm::Intrinsic::eh_selector);

  llvm::BasicBlock *PrevLandingPad = TryInfo.SavedLandingPad;
  llvm::BasicBlock *TryHandler = TryInfo.HandlerBlock;
  llvm::BasicBlock *FinallyBlock = TryInfo.FinallyBlock;
  llvm::BasicBlock *FinallyRethrow = createBasicBlock("finally.throw");
  llvm::BasicBlock *FinallyEnd = createBasicBlock("finally.end");

  // Jump to end if there is no exception
  EmitBranchThroughCleanup(FinallyEnd);

  llvm::BasicBlock *TerminateHandler = getTerminateHandler();

  // Emit the handlers
  EmitBlock(TryHandler);

  const llvm::IntegerType *Int8Ty;
  const llvm::PointerType *PtrToInt8Ty;
  Int8Ty = llvm::Type::getInt8Ty(VMContext);
  // C string type.  Used in lots of places.
  PtrToInt8Ty = llvm::PointerType::getUnqual(Int8Ty);
  llvm::Constant *Null = llvm::ConstantPointerNull::get(PtrToInt8Ty);
  llvm::SmallVector<llvm::Value*, 8> SelectorArgs;
  llvm::Value *llvm_eh_typeid_for =
    CGM.getIntrinsic(llvm::Intrinsic::eh_typeid_for);
  // Exception object
  llvm::Value *Exc = Builder.CreateCall(llvm_eh_exception, "exc");
  llvm::Value *RethrowPtr = CreateTempAlloca(Exc->getType(), "_rethrow");

  SelectorArgs.push_back(Exc);
  SelectorArgs.push_back(Personality);

  bool HasCatchAll = false;
  for (unsigned i = 0; i<S.getNumHandlers(); ++i) {
    const CXXCatchStmt *C = S.getHandler(i);
    VarDecl *CatchParam = C->getExceptionDecl();
    if (CatchParam) {
      // C++ [except.handle]p3 indicates that top-level cv-qualifiers
      // are ignored.
      QualType CaughtType = C->getCaughtType().getNonReferenceType();
      llvm::Value *EHTypeInfo
        = CGM.GetAddrOfRTTIDescriptor(CaughtType.getUnqualifiedType());
      SelectorArgs.push_back(EHTypeInfo);
    } else {
      // null indicates catch all
      SelectorArgs.push_back(Null);
      HasCatchAll = true;
    }
  }

  // We use a cleanup unless there was already a catch all.
  if (!HasCatchAll) {
    SelectorArgs.push_back(Null);
  }

  // Find which handler was matched.
  llvm::Value *Selector
    = Builder.CreateCall(llvm_eh_selector, SelectorArgs.begin(),
                         SelectorArgs.end(), "selector");
  for (unsigned i = 0; i<S.getNumHandlers(); ++i) {
    const CXXCatchStmt *C = S.getHandler(i);
    VarDecl *CatchParam = C->getExceptionDecl();
    Stmt *CatchBody = C->getHandlerBlock();

    llvm::BasicBlock *Next = 0;

    if (SelectorArgs[i+2] != Null) {
      llvm::BasicBlock *Match = createBasicBlock("match");
      Next = createBasicBlock("catch.next");
      const llvm::Type *Int8PtrTy = llvm::Type::getInt8PtrTy(getLLVMContext());
      llvm::Value *Id
        = Builder.CreateCall(llvm_eh_typeid_for,
                             Builder.CreateBitCast(SelectorArgs[i+2],
                                                   Int8PtrTy));
      Builder.CreateCondBr(Builder.CreateICmpEQ(Selector, Id),
                           Match, Next);
      EmitBlock(Match);
    }

    llvm::BasicBlock *MatchEnd = createBasicBlock("match.end");
    llvm::BasicBlock *MatchHandler = createBasicBlock("match.handler");

    PushCleanupBlock(MatchEnd);
    setInvokeDest(MatchHandler);

    llvm::Value *ExcObject = Builder.CreateCall(getBeginCatchFn(*this), Exc);

    {
//.........这里部分代码省略.........

 void ICEVisitor::VisitImplicitCastExpr(ImplicitCastExpr *CE) {
   const NamedDecl *ACD = dyn_cast<NamedDecl>(AC->getDecl());
   VisitChildren(CE);
   const Expr *SE = CE->getSubExprAsWritten();
   std::string sename = SE->getType().getAsString();
   const clang::Expr *E = CE->getSubExpr();
   if (!(sename == "EventNumber_t"))
     return;
   QualType OTy = BR.getContext().getCanonicalType(E->getType());
   QualType TTy = BR.getContext().getCanonicalType(CE->getType());
   QualType ToTy = TTy.getUnqualifiedType();
   QualType OrigTy = OTy.getUnqualifiedType();
   if (!(ToTy->isIntegerType() || ToTy->isFloatingType()))
     return;
   if (ToTy->isBooleanType())
     return;
   CharUnits size_otype = BR.getContext().getTypeSizeInChars(OrigTy);
   CharUnits size_ttype = BR.getContext().getTypeSizeInChars(ToTy);
   std::string oname = OrigTy.getAsString();
   std::string tname = ToTy.getAsString();
   if (ToTy->isFloatingType()) {
     llvm::SmallString<100> buf;
     llvm::raw_svector_ostream os(buf);
     os << "Cast-to type, " << tname << ". Cast-from type, " << oname << " . " << support::getQualifiedName(*(ACD));
     clang::ento::PathDiagnosticLocation CELoc =
         clang::ento::PathDiagnosticLocation::createBegin(CE, BR.getSourceManager(), AC);
     BR.EmitBasicReport(ACD,
                        CheckName(),
                        "implicit cast of int type to float type",
                        "CMS code rules",
                        os.str(),
                        CELoc,
                        CE->getSourceRange());
   }
   if ((size_otype > size_ttype)) {
     llvm::SmallString<100> buf;
     llvm::raw_svector_ostream os(buf);
     os << "Cast-to type, " << tname << ". Cast-from type, " << oname << ". Cast may result in truncation. "
        << support::getQualifiedName(*(ACD));
     clang::ento::PathDiagnosticLocation CELoc =
         clang::ento::PathDiagnosticLocation::createBegin(CE, BR.getSourceManager(), AC);
     BR.EmitBasicReport(ACD,
                        CheckName(),
                        "implicit cast of int type to smaller int type could truncate",
                        "CMS code rules",
                        os.str(),
                        CELoc,
                        CE->getSourceRange());
   }
   if (ToTy->hasSignedIntegerRepresentation() && OrigTy->hasUnsignedIntegerRepresentation() ||
       ToTy->hasUnsignedIntegerRepresentation() && OrigTy->hasSignedIntegerRepresentation()) {
     llvm::SmallString<100> buf;
     llvm::raw_svector_ostream os(buf);
     os << "Cast-to type, " << tname << ". Cast-from type, " << oname << ". Changes int sign type. "
        << support::getQualifiedName(*(ACD));
     clang::ento::PathDiagnosticLocation CELoc =
         clang::ento::PathDiagnosticLocation::createBegin(CE, BR.getSourceManager(), AC);
     BR.EmitBasicReport(ACD,
                        CheckName(),
                        "implicit cast changes int sign type",
                        "CMS code rules",
                        os.str(),
                        CELoc,
                        CE->getSourceRange());
   }
   return;
 }

/// CheckDynamicCast - Check that a dynamic_cast\<DestType\>(SrcExpr) is valid.
/// Refer to C++ 5.2.7 for details. Dynamic casts are used mostly for runtime-
/// checked downcasts in class hierarchies.
void
CheckDynamicCast(Sema &Self, Expr *&SrcExpr, QualType DestType,
                 const SourceRange &OpRange,
                 const SourceRange &DestRange)
{
  QualType OrigDestType = DestType, OrigSrcType = SrcExpr->getType();
  DestType = Self.Context.getCanonicalType(DestType);

  // C++ 5.2.7p1: T shall be a pointer or reference to a complete class type,
  //   or "pointer to cv void".

  QualType DestPointee;
  const PointerType *DestPointer = DestType->getAsPointerType();
  const ReferenceType *DestReference = DestType->getAsReferenceType();
  if (DestPointer) {
    DestPointee = DestPointer->getPointeeType();
  } else if (DestReference) {
    DestPointee = DestReference->getPointeeType();
  } else {
    Self.Diag(OpRange.getBegin(), diag::err_bad_dynamic_cast_not_ref_or_ptr)
      << OrigDestType << DestRange;
    return;
  }

  const RecordType *DestRecord = DestPointee->getAsRecordType();
  if (DestPointee->isVoidType()) {
    assert(DestPointer && "Reference to void is not possible");
  } else if (DestRecord) {
    if (Self.RequireCompleteType(OpRange.getBegin(), DestPointee, 
                                    diag::err_bad_dynamic_cast_incomplete,
                                    DestRange))
      return;
  } else {
    Self.Diag(OpRange.getBegin(), diag::err_bad_dynamic_cast_not_class)
      << DestPointee.getUnqualifiedType() << DestRange;
    return;
  }

  // C++0x 5.2.7p2: If T is a pointer type, v shall be an rvalue of a pointer to
  //   complete class type, [...]. If T is an lvalue reference type, v shall be
  //   an lvalue of a complete class type, [...]. If T is an rvalue reference
  //   type, v shall be an expression having a complete effective class type,
  //   [...]

  QualType SrcType = Self.Context.getCanonicalType(OrigSrcType);
  QualType SrcPointee;
  if (DestPointer) {
    if (const PointerType *SrcPointer = SrcType->getAsPointerType()) {
      SrcPointee = SrcPointer->getPointeeType();
    } else {
      Self.Diag(OpRange.getBegin(), diag::err_bad_dynamic_cast_not_ptr)
        << OrigSrcType << SrcExpr->getSourceRange();
      return;
    }
  } else if (DestReference->isLValueReferenceType()) {
    if (SrcExpr->isLvalue(Self.Context) != Expr::LV_Valid) {
      Self.Diag(OpRange.getBegin(), diag::err_bad_cxx_cast_rvalue)
        << "dynamic_cast" << OrigDestType << OpRange;
    }
    SrcPointee = SrcType;
  } else {
    SrcPointee = SrcType;
  }

  const RecordType *SrcRecord = SrcPointee->getAsRecordType();
  if (SrcRecord) {
    if (Self.RequireCompleteType(OpRange.getBegin(), SrcPointee,
                                    diag::err_bad_dynamic_cast_incomplete,
                                    SrcExpr->getSourceRange()))
      return;
  } else {
    Self.Diag(OpRange.getBegin(), diag::err_bad_dynamic_cast_not_class)
      << SrcPointee.getUnqualifiedType() << SrcExpr->getSourceRange();
    return;
  }

  assert((DestPointer || DestReference) &&
    "Bad destination non-ptr/ref slipped through.");
  assert((DestRecord || DestPointee->isVoidType()) &&
    "Bad destination pointee slipped through.");
  assert(SrcRecord && "Bad source pointee slipped through.");

  // C++ 5.2.7p1: The dynamic_cast operator shall not cast away constness.
  if (!DestPointee.isAtLeastAsQualifiedAs(SrcPointee)) {
    Self.Diag(OpRange.getBegin(), diag::err_bad_cxx_cast_const_away)
      << "dynamic_cast" << OrigDestType << OrigSrcType << OpRange;
    return;
  }

  // C++ 5.2.7p3: If the type of v is the same as the required result type,
  //   [except for cv].
  if (DestRecord == SrcRecord) {
    return;
  }

  // C++ 5.2.7p5
  // Upcasts are resolved statically.
//.........这里部分代码省略.........

/// TryStaticDowncast - Common functionality of TryStaticReferenceDowncast and
/// TryStaticPointerDowncast. Tests whether a static downcast from SrcType to
/// DestType, both of which must be canonical, is possible and allowed.
TryStaticCastResult
TryStaticDowncast(Sema &Self, QualType SrcType, QualType DestType,
                  const SourceRange &OpRange, QualType OrigSrcType,
                  QualType OrigDestType)
{
  // Downcast can only happen in class hierarchies, so we need classes.
  if (!DestType->isRecordType() || !SrcType->isRecordType()) {
    return TSC_NotApplicable;
  }

  BasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/false,
                  /*DetectVirtual=*/true);
  if (!Self.IsDerivedFrom(DestType, SrcType, Paths)) {
    return TSC_NotApplicable;
  }

  // Target type does derive from source type. Now we're serious. If an error
  // appears now, it's not ignored.
  // This may not be entirely in line with the standard. Take for example:
  // struct A {};
  // struct B : virtual A {
  //   B(A&);
  // };
  // 
  // void f()
  // {
  //   (void)static_cast<const B&>(*((A*)0));
  // }
  // As far as the standard is concerned, p5 does not apply (A is virtual), so
  // p2 should be used instead - "const B& t(*((A*)0));" is perfectly valid.
  // However, both GCC and Comeau reject this example, and accepting it would
  // mean more complex code if we're to preserve the nice error message.
  // FIXME: Being 100% compliant here would be nice to have.

  // Must preserve cv, as always.
  if (!DestType.isAtLeastAsQualifiedAs(SrcType)) {
    Self.Diag(OpRange.getBegin(), diag::err_bad_cxx_cast_const_away)
      << "static_cast" << OrigDestType << OrigSrcType << OpRange;
    return TSC_Failed;
  }

  if (Paths.isAmbiguous(SrcType.getUnqualifiedType())) {
    // This code is analoguous to that in CheckDerivedToBaseConversion, except
    // that it builds the paths in reverse order.
    // To sum up: record all paths to the base and build a nice string from
    // them. Use it to spice up the error message.
    Paths.clear();
    Paths.setRecordingPaths(true);
    Self.IsDerivedFrom(DestType, SrcType, Paths);
    std::string PathDisplayStr;
    std::set<unsigned> DisplayedPaths;
    for (BasePaths::paths_iterator Path = Paths.begin();
         Path != Paths.end(); ++Path) {
      if (DisplayedPaths.insert(Path->back().SubobjectNumber).second) {
        // We haven't displayed a path to this particular base
        // class subobject yet.
        PathDisplayStr += "\n    ";
        for (BasePath::const_reverse_iterator Element = Path->rbegin();
             Element != Path->rend(); ++Element)
          PathDisplayStr += Element->Base->getType().getAsString() + " -> ";
        PathDisplayStr += DestType.getAsString();
      }
    }

    Self.Diag(OpRange.getBegin(), diag::err_ambiguous_base_to_derived_cast)
      << SrcType.getUnqualifiedType() << DestType.getUnqualifiedType()
      << PathDisplayStr << OpRange;
    return TSC_Failed;
  }

  if (Paths.getDetectedVirtual() != 0) {
    QualType VirtualBase(Paths.getDetectedVirtual(), 0);
    Self.Diag(OpRange.getBegin(), diag::err_static_downcast_via_virtual)
      << OrigSrcType << OrigDestType << VirtualBase << OpRange;
    return TSC_Failed;
  }

  // FIXME: Test accessibility.

  return TSC_Success;
}

/// CheckConstCast - Check that a const_cast\<DestType\>(SrcExpr) is valid.
/// Refer to C++ 5.2.11 for details. const_cast is typically used in code
/// like this:
/// const char *str = "literal";
/// legacy_function(const_cast\<char*\>(str));
void
CheckConstCast(Sema &Self, Expr *&SrcExpr, QualType DestType,
               const SourceRange &OpRange, const SourceRange &DestRange)
{
  QualType OrigDestType = DestType, OrigSrcType = SrcExpr->getType();

  DestType = Self.Context.getCanonicalType(DestType);
  QualType SrcType = SrcExpr->getType();
  if (const LValueReferenceType *DestTypeTmp =
        DestType->getAsLValueReferenceType()) {
    if (SrcExpr->isLvalue(Self.Context) != Expr::LV_Valid) {
      // Cannot cast non-lvalue to lvalue reference type.
      Self.Diag(OpRange.getBegin(), diag::err_bad_cxx_cast_rvalue)
        << "const_cast" << OrigDestType << SrcExpr->getSourceRange();
      return;
    }

    // C++ 5.2.11p4: An lvalue of type T1 can be [cast] to an lvalue of type T2
    //   [...] if a pointer to T1 can be [cast] to the type pointer to T2.
    DestType = Self.Context.getPointerType(DestTypeTmp->getPointeeType());
    SrcType = Self.Context.getPointerType(SrcType);
  } else {
    // C++ 5.2.11p1: Otherwise, the result is an rvalue and the
    //   lvalue-to-rvalue, array-to-pointer, and function-to-pointer standard
    //   conversions are performed on the expression.
    Self.DefaultFunctionArrayConversion(SrcExpr);
    SrcType = SrcExpr->getType();
  }

  // C++ 5.2.11p5: For a const_cast involving pointers to data members [...]
  //   the rules for const_cast are the same as those used for pointers.

  if (!DestType->isPointerType() && !DestType->isMemberPointerType()) {
    // Cannot cast to non-pointer, non-reference type. Note that, if DestType
    // was a reference type, we converted it to a pointer above.
    // The status of rvalue references isn't entirely clear, but it looks like
    // conversion to them is simply invalid.
    // C++ 5.2.11p3: For two pointer types [...]
    Self.Diag(OpRange.getBegin(), diag::err_bad_const_cast_dest)
      << OrigDestType << DestRange;
    return;
  }
  if (DestType->isFunctionPointerType() ||
      DestType->isMemberFunctionPointerType()) {
    // Cannot cast direct function pointers.
    // C++ 5.2.11p2: [...] where T is any object type or the void type [...]
    // T is the ultimate pointee of source and target type.
    Self.Diag(OpRange.getBegin(), diag::err_bad_const_cast_dest)
      << OrigDestType << DestRange;
    return;
  }
  SrcType = Self.Context.getCanonicalType(SrcType);

  // Unwrap the pointers. Ignore qualifiers. Terminate early if the types are
  // completely equal.
  // FIXME: const_cast should probably not be able to convert between pointers
  // to different address spaces.
  // C++ 5.2.11p3 describes the core semantics of const_cast. All cv specifiers
  // in multi-level pointers may change, but the level count must be the same,
  // as must be the final pointee type.
  while (SrcType != DestType &&
         Self.UnwrapSimilarPointerTypes(SrcType, DestType)) {
    SrcType = SrcType.getUnqualifiedType();
    DestType = DestType.getUnqualifiedType();
  }

  // Doug Gregor said to disallow this until users complain.
#if 0
  // If we end up with constant arrays of equal size, unwrap those too. A cast
  // from const int [N] to int (&)[N] is invalid by my reading of the
  // standard, but g++ accepts it even with -ansi -pedantic.
  // No more than one level, though, so don't embed this in the unwrap loop
  // above.
  const ConstantArrayType *SrcTypeArr, *DestTypeArr;
  if ((SrcTypeArr = Self.Context.getAsConstantArrayType(SrcType)) &&
     (DestTypeArr = Self.Context.getAsConstantArrayType(DestType)))
  {
    if (SrcTypeArr->getSize() != DestTypeArr->getSize()) {
      // Different array sizes.
      Self.Diag(OpRange.getBegin(), diag::err_bad_cxx_cast_generic)
        << "const_cast" << OrigDestType << OrigSrcType << OpRange;
      return;
    }
    SrcType = SrcTypeArr->getElementType().getUnqualifiedType();
    DestType = DestTypeArr->getElementType().getUnqualifiedType();
  }
#endif

  // Since we're dealing in canonical types, the remainder must be the same.
  if (SrcType != DestType) {
    // Cast between unrelated types.
    Self.Diag(OpRange.getBegin(), diag::err_bad_cxx_cast_generic)
      << "const_cast" << OrigDestType << OrigSrcType << OpRange;
    return;
  }
//.........这里部分代码省略.........