C++ QualType::getAsRecordType方法代码示例

/// FindAllocationFunctions - Finds the overloads of operator new and delete
/// that are appropriate for the allocation.
bool Sema::FindAllocationFunctions(SourceLocation StartLoc, SourceRange Range,
                                   bool UseGlobal, QualType AllocType,
                                   bool IsArray, Expr **PlaceArgs,
                                   unsigned NumPlaceArgs,
                                   FunctionDecl *&OperatorNew,
                                   FunctionDecl *&OperatorDelete)
{
  // --- Choosing an allocation function ---
  // C++ 5.3.4p8 - 14 & 18
  // 1) If UseGlobal is true, only look in the global scope. Else, also look
  //   in the scope of the allocated class.
  // 2) If an array size is given, look for operator new[], else look for
  //   operator new.
  // 3) The first argument is always size_t. Append the arguments from the
  //   placement form.
  // FIXME: Also find the appropriate delete operator.

  llvm::SmallVector<Expr*, 8> AllocArgs(1 + NumPlaceArgs);
  // We don't care about the actual value of this argument.
  // FIXME: Should the Sema create the expression and embed it in the syntax
  // tree? Or should the consumer just recalculate the value?
  AllocArgs[0] = new (Context) IntegerLiteral(llvm::APInt::getNullValue(
                                        Context.Target.getPointerWidth(0)),
                                    Context.getSizeType(),
                                    SourceLocation());
  std::copy(PlaceArgs, PlaceArgs + NumPlaceArgs, AllocArgs.begin() + 1);

  DeclarationName NewName = Context.DeclarationNames.getCXXOperatorName(
                                        IsArray ? OO_Array_New : OO_New);
  if (AllocType->isRecordType() && !UseGlobal) {
    CXXRecordDecl *Record 
      = cast<CXXRecordDecl>(AllocType->getAsRecordType()->getDecl());
    // FIXME: We fail to find inherited overloads.
    if (FindAllocationOverload(StartLoc, Range, NewName, &AllocArgs[0],
                          AllocArgs.size(), Record, /*AllowMissing=*/true,
                          OperatorNew))
      return true;
  }
  if (!OperatorNew) {
    // Didn't find a member overload. Look for a global one.
    DeclareGlobalNewDelete();
    DeclContext *TUDecl = Context.getTranslationUnitDecl();
    if (FindAllocationOverload(StartLoc, Range, NewName, &AllocArgs[0],
                          AllocArgs.size(), TUDecl, /*AllowMissing=*/false,
                          OperatorNew))
      return true;
  }

  // FIXME: This is leaked on error. But so much is currently in Sema that it's
  // easier to clean it in one go.
  AllocArgs[0]->Destroy(Context);
  return false;
}

/// ActOnCXXConditionDeclarationExpr - Parsed a condition declaration of a
/// C++ if/switch/while/for statement.
/// e.g: "if (int x = f()) {...}"
Action::OwningExprResult
Sema::ActOnCXXConditionDeclarationExpr(Scope *S, SourceLocation StartLoc,
                                       Declarator &D,
                                       SourceLocation EqualLoc,
                                       ExprArg AssignExprVal) {
  assert(AssignExprVal.get() && "Null assignment expression");

  // C++ 6.4p2:
  // The declarator shall not specify a function or an array.
  // The type-specifier-seq shall not contain typedef and shall not declare a
  // new class or enumeration.

  assert(D.getDeclSpec().getStorageClassSpec() != DeclSpec::SCS_typedef &&
         "Parser allowed 'typedef' as storage class of condition decl.");

  QualType Ty = GetTypeForDeclarator(D, S);
  
  if (Ty->isFunctionType()) { // The declarator shall not specify a function...
    // We exit without creating a CXXConditionDeclExpr because a FunctionDecl
    // would be created and CXXConditionDeclExpr wants a VarDecl.
    return ExprError(Diag(StartLoc, diag::err_invalid_use_of_function_type)
      << SourceRange(StartLoc, EqualLoc));
  } else if (Ty->isArrayType()) { // ...or an array.
    Diag(StartLoc, diag::err_invalid_use_of_array_type)
      << SourceRange(StartLoc, EqualLoc);
  } else if (const RecordType *RT = Ty->getAsRecordType()) {
    RecordDecl *RD = RT->getDecl();
    // The type-specifier-seq shall not declare a new class...
    if (RD->isDefinition() &&
        (RD->getIdentifier() == 0 || S->isDeclScope(DeclPtrTy::make(RD))))
      Diag(RD->getLocation(), diag::err_type_defined_in_condition);
  } else if (const EnumType *ET = Ty->getAsEnumType()) {
    EnumDecl *ED = ET->getDecl();
    // ...or enumeration.
    if (ED->isDefinition() &&
        (ED->getIdentifier() == 0 || S->isDeclScope(DeclPtrTy::make(ED))))
      Diag(ED->getLocation(), diag::err_type_defined_in_condition);
  }

  DeclPtrTy Dcl = ActOnDeclarator(S, D, DeclPtrTy());
  if (!Dcl)
    return ExprError();
  AddInitializerToDecl(Dcl, move(AssignExprVal));

  // Mark this variable as one that is declared within a conditional.
  // We know that the decl had to be a VarDecl because that is the only type of
  // decl that can be assigned and the grammar requires an '='.
  VarDecl *VD = cast<VarDecl>(Dcl.getAs<Decl>());
  VD->setDeclaredInCondition(true);
  return Owned(new (Context) CXXConditionDeclExpr(StartLoc, EqualLoc, VD));
}

/// ActOnCXXTypeConstructExpr - Parse construction of a specified type.
/// Can be interpreted either as function-style casting ("int(x)")
/// or class type construction ("ClassType(x,y,z)")
/// or creation of a value-initialized type ("int()").
Action::OwningExprResult
Sema::ActOnCXXTypeConstructExpr(SourceRange TypeRange, TypeTy *TypeRep,
                                SourceLocation LParenLoc,
                                MultiExprArg exprs,
                                SourceLocation *CommaLocs,
                                SourceLocation RParenLoc) {
  assert(TypeRep && "Missing type!");
  QualType Ty = QualType::getFromOpaquePtr(TypeRep);
  unsigned NumExprs = exprs.size();
  Expr **Exprs = (Expr**)exprs.get();
  SourceLocation TyBeginLoc = TypeRange.getBegin();
  SourceRange FullRange = SourceRange(TyBeginLoc, RParenLoc);

  if (Ty->isDependentType() ||
      CallExpr::hasAnyTypeDependentArguments(Exprs, NumExprs)) {
    exprs.release();
    return Owned(new (Context) CXXTemporaryObjectExpr(0, Ty, TyBeginLoc,
                                                      Exprs, NumExprs,
                                                      RParenLoc));
  }


  // C++ [expr.type.conv]p1:
  // If the expression list is a single expression, the type conversion
  // expression is equivalent (in definedness, and if defined in meaning) to the
  // corresponding cast expression.
  //
  if (NumExprs == 1) {
    if (CheckCastTypes(TypeRange, Ty, Exprs[0]))
      return ExprError();
    exprs.release();
    return Owned(new (Context) CXXFunctionalCastExpr(Ty.getNonReferenceType(),
                                                     Ty, TyBeginLoc, Exprs[0],
                                                     RParenLoc));
  }

  if (const RecordType *RT = Ty->getAsRecordType()) {
    CXXRecordDecl *Record = cast<CXXRecordDecl>(RT->getDecl());

    if (NumExprs > 1 || Record->hasUserDeclaredConstructor()) {
      CXXConstructorDecl *Constructor
        = PerformInitializationByConstructor(Ty, Exprs, NumExprs,
                                             TypeRange.getBegin(),
                                             SourceRange(TypeRange.getBegin(),
                                                         RParenLoc),
                                             DeclarationName(),
                                             IK_Direct);

      if (!Constructor)
        return ExprError();

      exprs.release();
      return Owned(new (Context) CXXTemporaryObjectExpr(Constructor, Ty,
                                                        TyBeginLoc,  Exprs,
                                                        NumExprs, RParenLoc));
    }

    // Fall through to value-initialize an object of class type that
    // doesn't have a user-declared default constructor.
  }

  // C++ [expr.type.conv]p1:
  // If the expression list specifies more than a single value, the type shall
  // be a class with a suitably declared constructor.
  //
  if (NumExprs > 1)
    return ExprError(Diag(CommaLocs[0],
                          diag::err_builtin_func_cast_more_than_one_arg)
      << FullRange);

  assert(NumExprs == 0 && "Expected 0 expressions");

  // C++ [expr.type.conv]p2:
  // The expression T(), where T is a simple-type-specifier for a non-array
  // complete object type or the (possibly cv-qualified) void type, creates an
  // rvalue of the specified type, which is value-initialized.
  //
  if (Ty->isArrayType())
    return ExprError(Diag(TyBeginLoc,
                          diag::err_value_init_for_array_type) << FullRange);
  if (!Ty->isDependentType() && !Ty->isVoidType() &&
      RequireCompleteType(TyBeginLoc, Ty,
                          diag::err_invalid_incomplete_type_use, FullRange))
    return ExprError();

  if (RequireNonAbstractType(TyBeginLoc, Ty,
                             diag::err_allocation_of_abstract_type))
    return ExprError();
  
  exprs.release();
  return Owned(new (Context) CXXZeroInitValueExpr(Ty, TyBeginLoc, RParenLoc));
}

std::string DeclarationName::getAsString() const {
  switch (getNameKind()) {
  case Identifier:
    if (const IdentifierInfo *II = getAsIdentifierInfo())
      return II->getName();
    return "";

  case ObjCZeroArgSelector:
  case ObjCOneArgSelector:
  case ObjCMultiArgSelector:
    return getObjCSelector().getAsString();

  case CXXConstructorName: {
    QualType ClassType = getCXXNameType();
    if (const RecordType *ClassRec = ClassType->getAsRecordType())
      return ClassRec->getDecl()->getNameAsString();
    return ClassType.getAsString();
  }

  case CXXDestructorName: {
    std::string Result = "~";
    QualType Type = getCXXNameType();
    if (const RecordType *Rec = Type->getAsRecordType())
      Result += Rec->getDecl()->getNameAsString();
    else
      Result += Type.getAsString();
    return Result;
  }

  case CXXOperatorName: {
    static const char *OperatorNames[NUM_OVERLOADED_OPERATORS] = {
      0,
#define OVERLOADED_OPERATOR(Name,Spelling,Token,Unary,Binary,MemberOnly) \
      Spelling,
#include "clang/Basic/OperatorKinds.def"
    };
    const char *OpName = OperatorNames[getCXXOverloadedOperator()];
    assert(OpName && "not an overloaded operator");
      
    std::string Result = "operator";
    if (OpName[0] >= 'a' && OpName[0] <= 'z')
      Result += ' ';
    Result += OpName;
    return Result;
  }

  case CXXConversionFunctionName: {
    std::string Result = "operator ";
    QualType Type = getCXXNameType();
    if (const RecordType *Rec = Type->getAsRecordType())
      Result += Rec->getDecl()->getNameAsString();
    else
      Result += Type.getAsString();
    return Result;
  }
  case CXXUsingDirective:
    return "<using-directive>";
  }

  assert(false && "Unexpected declaration name kind");
  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.........