// It would be nice to make this a virtual method on typeSym.
public AggregateType GetAggTypeSym(CType typeSym)
{
Debug.Assert(typeSym != null);
Debug.Assert(typeSym.IsAggregateType() ||
typeSym.IsTypeParameterType() ||
typeSym.IsArrayType() ||
typeSym.IsNullableType());
switch (typeSym.GetTypeKind())
{
case TypeKind.TK_AggregateType:
return(typeSym.AsAggregateType());
case TypeKind.TK_ArrayType:
return(GetReqPredefType(PredefinedType.PT_ARRAY));
case TypeKind.TK_TypeParameterType:
return(typeSym.AsTypeParameterType().GetEffectiveBaseClass());
case TypeKind.TK_NullableType:
return(typeSym.AsNullableType().GetAts(ErrorContext));
}
Debug.Assert(false, "Bad typeSym!");
return(null);
}
public virtual ACCESSERROR CheckAccess2(Symbol symCheck, AggregateType atsCheck, Symbol symWhere, CType typeThru)
{
Debug.Assert(symCheck != null);
Debug.Assert(atsCheck == null || symCheck.parent == atsCheck.getAggregate());
Debug.Assert(typeThru == null ||
typeThru.IsAggregateType() ||
typeThru.IsTypeParameterType() ||
typeThru.IsArrayType() ||
typeThru.IsNullableType() ||
typeThru.IsErrorType());
#if DEBUG
switch (symCheck.getKind())
{
default:
break;
case SYMKIND.SK_MethodSymbol:
case SYMKIND.SK_PropertySymbol:
case SYMKIND.SK_FieldSymbol:
case SYMKIND.SK_EventSymbol:
Debug.Assert(atsCheck != null);
break;
}
#endif // DEBUG
ACCESSERROR error = CheckAccessCore(symCheck, atsCheck, symWhere, typeThru);
if (ACCESSERROR.ACCESSERROR_NOERROR != error)
{
return error;
}
// Check the accessibility of the return CType.
CType CType = symCheck.getType();
if (CType == null)
{
return ACCESSERROR.ACCESSERROR_NOERROR;
}
// For members of AGGSYMs, atsCheck should always be specified!
Debug.Assert(atsCheck != null);
if (atsCheck.getAggregate().IsSource())
{
// We already check the "at least as accessible as" rules.
// Does this always work for generics?
// Could we get a bad CType argument in typeThru?
// Maybe call CheckTypeAccess on typeThru?
return ACCESSERROR.ACCESSERROR_NOERROR;
}
// Substitute on the CType.
if (atsCheck.GetTypeArgsAll().size > 0)
{
CType = SymbolLoader.GetTypeManager().SubstType(CType, atsCheck);
}
return CheckTypeAccess(CType, symWhere) ? ACCESSERROR.ACCESSERROR_NOERROR : ACCESSERROR.ACCESSERROR_NOACCESS;
}
public virtual ACCESSERROR CheckAccess2(Symbol symCheck, AggregateType atsCheck, Symbol symWhere, CType typeThru)
{
Debug.Assert(symCheck != null);
Debug.Assert(atsCheck == null || symCheck.parent == atsCheck.getAggregate());
Debug.Assert(typeThru == null ||
typeThru.IsAggregateType() ||
typeThru.IsTypeParameterType() ||
typeThru.IsArrayType() ||
typeThru.IsNullableType() ||
typeThru.IsErrorType());
#if DEBUG
switch (symCheck.getKind())
{
default:
break;
case SYMKIND.SK_MethodSymbol:
case SYMKIND.SK_PropertySymbol:
case SYMKIND.SK_FieldSymbol:
case SYMKIND.SK_EventSymbol:
Debug.Assert(atsCheck != null);
break;
}
#endif // DEBUG
ACCESSERROR error = CheckAccessCore(symCheck, atsCheck, symWhere, typeThru);
if (ACCESSERROR.ACCESSERROR_NOERROR != error)
{
return(error);
}
// Check the accessibility of the return CType.
CType CType = symCheck.getType();
if (CType == null)
{
return(ACCESSERROR.ACCESSERROR_NOERROR);
}
// For members of AGGSYMs, atsCheck should always be specified!
Debug.Assert(atsCheck != null);
if (atsCheck.getAggregate().IsSource())
{
// We already check the "at least as accessible as" rules.
// Does this always work for generics?
// Could we get a bad CType argument in typeThru?
// Maybe call CheckTypeAccess on typeThru?
return(ACCESSERROR.ACCESSERROR_NOERROR);
}
// Substitute on the CType.
if (atsCheck.GetTypeArgsAll().size > 0)
{
CType = SymbolLoader.GetTypeManager().SubstType(CType, atsCheck);
}
return(CheckTypeAccess(CType, symWhere) ? ACCESSERROR.ACCESSERROR_NOERROR : ACCESSERROR.ACCESSERROR_NOACCESS);
}
public bool HasImplicitBoxingConversion(CType pSource, CType pDest)
{
Debug.Assert(pSource != null);
Debug.Assert(pDest != null);
// Certain type parameter conversions are classified as boxing conversions.
if (pSource.IsTypeParameterType() &&
HasImplicitBoxingTypeParameterConversion(pSource.AsTypeParameterType(), pDest))
{
return(true);
}
// The rest of the boxing conversions only operate when going from a value type
// to a reference type.
if (!pSource.IsValType() || !pDest.IsRefType())
{
return(false);
}
// A boxing conversion exists from a nullable type to a reference type
// if and only if a boxing conversion exists from the underlying type.
if (pSource.IsNullableType())
{
return(HasImplicitBoxingConversion(pSource.AsNullableType().GetUnderlyingType(), pDest));
}
// A boxing conversion exists from any non-nullable value type to object,
// to System.ValueType, and to any interface type implemented by the
// non-nullable value type. Furthermore, an enum type can be converted
// to the type System.Enum.
// We set the base class of the structs to System.ValueType, System.Enum, etc,
// so we can just check here.
if (IsBaseClass(pSource, pDest))
{
return(true);
}
if (HasAnyBaseInterfaceConversion(pSource, pDest))
{
return(true);
}
return(false);
}
private bool IsBaseClass(CType pDerived, CType pBase)
{
Debug.Assert(pDerived != null);
Debug.Assert(pBase != null);
// A base class has got to be a class. The derived type might be a struct.
if (!pBase.isClassType())
{
return(false);
}
if (pDerived.IsNullableType())
{
pDerived = pDerived.AsNullableType().GetAts(ErrorContext);
if (pDerived == null)
{
return(false);
}
}
if (!pDerived.IsAggregateType())
{
return(false);
}
AggregateType atsDer = pDerived.AsAggregateType();
AggregateType atsBase = pBase.AsAggregateType();
AggregateType atsCur = atsDer.GetBaseClass();
while (atsCur != null)
{
if (atsCur == atsBase)
{
return(true);
}
atsCur = atsCur.GetBaseClass();
}
return(false);
}
private bool HasImplicitReferenceConversion(CType pSource, CType pDest)
{
Debug.Assert(pSource != null);
Debug.Assert(pDest != null);
// The implicit reference conversions are:
// * From any reference type to Object.
if (pSource.IsRefType() && pDest.isPredefType(PredefinedType.PT_OBJECT))
{
return(true);
}
// * From any class type S to any class type T provided S is derived from T.
if (pSource.isClassType() && pDest.isClassType() && IsBaseClass(pSource, pDest))
{
return(true);
}
// ORIGINAL RULES:
// // * From any class type S to any interface type T provided S implements T.
// if (pSource.isClassType() && pDest.isInterfaceType() && IsBaseInterface(pSource, pDest))
// {
// return true;
// }
// // * from any interface type S to any interface type T, provided S is derived from T.
// if (pSource.isInterfaceType() && pDest.isInterfaceType() && IsBaseInterface(pSource, pDest))
// {
// return true;
// }
// VARIANCE EXTENSIONS:
// * From any class type S to any interface type T provided S implements an interface
// convertible to T.
// * From any interface type S to any interface type T provided S implements an interface
// convertible to T.
// * From any interface type S to any interface type T provided S is not T and S is
// an interface convertible to T.
if (pSource.isClassType() && pDest.isInterfaceType() && HasAnyBaseInterfaceConversion(pSource, pDest))
{
return(true);
}
if (pSource.isInterfaceType() && pDest.isInterfaceType() && HasAnyBaseInterfaceConversion(pSource, pDest))
{
return(true);
}
if (pSource.isInterfaceType() && pDest.isInterfaceType() && pSource != pDest &&
HasInterfaceConversion(pSource.AsAggregateType(), pDest.AsAggregateType()))
{
return(true);
}
// * From an array type S with an element type SE to an array type T with element type TE
// provided that all of the following are true:
// * S and T differ only in element type. In other words, S and T have the same number of dimensions.
// * Both SE and TE are reference types.
// * An implicit reference conversion exists from SE to TE.
if (pSource.IsArrayType() && pDest.IsArrayType() &&
HasCovariantArrayConversion(pSource.AsArrayType(), pDest.AsArrayType()))
{
return(true);
}
// * From any array type to System.Array or any interface implemented by System.Array.
if (pSource.IsArrayType() && (pDest.isPredefType(PredefinedType.PT_ARRAY) ||
IsBaseInterface(GetReqPredefType(PredefinedType.PT_ARRAY, false), pDest)))
{
return(true);
}
// * From a single-dimensional array type S[] to IList<T> and its base
// interfaces, provided that there is an implicit identity or reference
// conversion from S to T.
if (pSource.IsArrayType() && HasArrayConversionToInterface(pSource.AsArrayType(), pDest))
{
return(true);
}
// * From any delegate type to System.Delegate
//
// SPEC OMISSION:
//
// The spec should actually say
//
// * From any delegate type to System.Delegate
// * From any delegate type to System.MulticastDelegate
// * From any delegate type to any interface implemented by System.MulticastDelegate
if (pSource.isDelegateType() &&
(pDest.isPredefType(PredefinedType.PT_MULTIDEL) ||
pDest.isPredefType(PredefinedType.PT_DELEGATE) ||
IsBaseInterface(GetReqPredefType(PredefinedType.PT_MULTIDEL, false), pDest)))
{
return(true);
}
// VARIANCE EXTENSION:
// * From any delegate type S to a delegate type T provided S is not T and
// S is a delegate convertible to T
if (pSource.isDelegateType() && pDest.isDelegateType() &&
HasDelegateConversion(pSource.AsAggregateType(), pDest.AsAggregateType()))
{
return(true);
}
// * From the null literal to any reference type
// NOTE: We extend the specification here. The C# 3.0 spec does not describe
// a "null type". Rather, it says that the null literal is typeless, and is
// convertible to any reference or nullable type. However, the C# 2.0 and 3.0
// implementations have a "null type" which some expressions other than the
// null literal may have. (For example, (null??null), which is also an
// extension to the specification.)
if (pSource.IsNullType() && pDest.IsRefType())
{
return(true);
}
if (pSource.IsNullType() && pDest.IsNullableType())
{
return(true);
}
// * Implicit conversions involving type parameters that are known to be reference types.
if (pSource.IsTypeParameterType() &&
HasImplicitReferenceTypeParameterConversion(pSource.AsTypeParameterType(), pDest))
{
return(true);
}
return(false);
}
//
// SymbolLoader forwarders (end)
/////////////////////////////////////////////////////////////////////////////////
//
// Utility methods
//
protected ACCESSERROR CheckAccessCore(Symbol symCheck, AggregateType atsCheck, Symbol symWhere, CType typeThru)
{
Debug.Assert(symCheck != null);
Debug.Assert(atsCheck == null || symCheck.parent == atsCheck.getAggregate());
Debug.Assert(typeThru == null ||
typeThru.IsAggregateType() ||
typeThru.IsTypeParameterType() ||
typeThru.IsArrayType() ||
typeThru.IsNullableType() ||
typeThru.IsErrorType());
switch (symCheck.GetAccess())
{
default:
throw Error.InternalCompilerError();
//return ACCESSERROR.ACCESSERROR_NOACCESS;
case ACCESS.ACC_UNKNOWN:
return ACCESSERROR.ACCESSERROR_NOACCESS;
case ACCESS.ACC_PUBLIC:
return ACCESSERROR.ACCESSERROR_NOERROR;
case ACCESS.ACC_PRIVATE:
case ACCESS.ACC_PROTECTED:
if (symWhere == null)
{
return ACCESSERROR.ACCESSERROR_NOACCESS;
}
break;
case ACCESS.ACC_INTERNAL:
case ACCESS.ACC_INTERNALPROTECTED: // Check internal, then protected.
if (symWhere == null)
{
return ACCESSERROR.ACCESSERROR_NOACCESS;
}
if (symWhere.SameAssemOrFriend(symCheck))
{
return ACCESSERROR.ACCESSERROR_NOERROR;
}
if (symCheck.GetAccess() == ACCESS.ACC_INTERNAL)
{
return ACCESSERROR.ACCESSERROR_NOACCESS;
}
break;
}
// Should always have atsCheck for private and protected access check.
// We currently don't need it since access doesn't respect instantiation.
// We just use symWhere.parent.AsAggregateSymbol() instead.
AggregateSymbol aggCheck = symCheck.parent.AsAggregateSymbol();
// Find the inner-most enclosing AggregateSymbol.
AggregateSymbol aggWhere = null;
for (Symbol symT = symWhere; symT != null; symT = symT.parent)
{
if (symT.IsAggregateSymbol())
{
aggWhere = symT.AsAggregateSymbol();
break;
}
if (symT.IsAggregateDeclaration())
{
aggWhere = symT.AsAggregateDeclaration().Agg();
break;
}
}
if (aggWhere == null)
{
return ACCESSERROR.ACCESSERROR_NOACCESS;
}
// First check for private access.
for (AggregateSymbol agg = aggWhere; agg != null; agg = agg.GetOuterAgg())
{
if (agg == aggCheck)
{
return ACCESSERROR.ACCESSERROR_NOERROR;
}
}
if (symCheck.GetAccess() == ACCESS.ACC_PRIVATE)
{
return ACCESSERROR.ACCESSERROR_NOACCESS;
}
// Handle the protected case - which is the only real complicated one.
Debug.Assert(symCheck.GetAccess() == ACCESS.ACC_PROTECTED || symCheck.GetAccess() == ACCESS.ACC_INTERNALPROTECTED);
// Check if symCheck is in aggWhere or a base of aggWhere,
// or in an outer agg of aggWhere or a base of an outer agg of aggWhere.
AggregateType atsThru = null;
if (typeThru != null && !symCheck.isStatic)
{
atsThru = SymbolLoader.GetAggTypeSym(typeThru);
}
// Look for aggCheck among the base classes of aggWhere and outer aggs.
bool found = false;
for (AggregateSymbol agg = aggWhere; agg != null; agg = agg.GetOuterAgg())
{
Debug.Assert(agg != aggCheck); // We checked for this above.
// Look for aggCheck among the base classes of agg.
if (agg.FindBaseAgg(aggCheck))
{
found = true;
// aggCheck is a base class of agg. Check atsThru.
// For non-static protected access to be legal, atsThru must be an instantiation of
// agg or a CType derived from an instantiation of agg. In this case
// all that matters is that agg is in the base AggregateSymbol chain of atsThru. The
// actual AGGTYPESYMs involved don't matter.
if (atsThru == null || atsThru.getAggregate().FindBaseAgg(agg))
{
return ACCESSERROR.ACCESSERROR_NOERROR;
}
}
}
// the CType in which the method is being called has no relationship with the
// CType on which the method is defined surely this is NOACCESS and not NOACCESSTHRU
if (found == false)
return ACCESSERROR.ACCESSERROR_NOACCESS;
return (atsThru == null) ? ACCESSERROR.ACCESSERROR_NOACCESS : ACCESSERROR.ACCESSERROR_NOACCESSTHRU;
}
/*
* BindImplicitConversion
*
* This is a complex routine with complex parameters. Generally, this should
* be called through one of the helper methods that insulates you
* from the complexity of the interface. This routine handles all the logic
* associated with implicit conversions.
*
* exprSrc - the expression being converted. Can be null if only type conversion
* info is being supplied.
* typeSrc - type of the source
* typeDest - type of the destination
* exprDest - returns an expression of the src converted to the dest. If null, we
* only care about whether the conversion can be attempted, not the
* expression tree.
* flags - flags possibly customizing the conversions allowed. E.g., can suppress
* user-defined conversions.
*
* returns true if the conversion can be made, false if not.
*/
public bool Bind()
{
// 13.1 Implicit conversions
//
// The following conversions are classified as implicit conversions:
//
// * Identity conversions
// * Implicit numeric conversions
// * Implicit enumeration conversions
// * Implicit reference conversions
// * Boxing conversions
// * Implicit type parameter conversions
// * Implicit constant expression conversions
// * User-defined implicit conversions
// * Implicit conversions from an anonymous method expression to a compatible delegate type
// * Implicit conversion from a method group to a compatible delegate type
// * Conversions from the null type (11.2.7) to any nullable type
// * Implicit nullable conversions
// * Lifted user-defined implicit conversions
//
// Implicit conversions can occur in a variety of situations, including function member invocations
// (14.4.3), cast expressions (14.6.6), and assignments (14.14).
// Can't convert to or from the error type.
if (typeSrc == null || typeDest == null || typeDest.IsNeverSameType())
{
return(false);
}
Debug.Assert(typeSrc != null && typeDest != null); // types must be supplied.
Debug.Assert(exprSrc == null || typeSrc == exprSrc.type); // type of source should be correct if source supplied
Debug.Assert(!needsExprDest || exprSrc != null); // need source expr to create dest expr
switch (typeDest.GetTypeKind())
{
case TypeKind.TK_ErrorType:
Debug.Assert(typeDest.AsErrorType().HasTypeParent() || typeDest.AsErrorType().HasNSParent());
if (typeSrc != typeDest)
{
return(false);
}
if (needsExprDest)
{
exprDest = exprSrc;
}
return(true);
case TypeKind.TK_NullType:
// Can only convert to the null type if src is null.
if (!typeSrc.IsNullType())
{
return(false);
}
if (needsExprDest)
{
exprDest = exprSrc;
}
return(true);
case TypeKind.TK_MethodGroupType:
VSFAIL("Something is wrong with Type.IsNeverSameType()");
return(false);
case TypeKind.TK_NaturalIntegerType:
case TypeKind.TK_ArgumentListType:
return(typeSrc == typeDest);
case TypeKind.TK_VoidType:
return(false);
default:
break;
}
if (typeSrc.IsErrorType())
{
Debug.Assert(!typeDest.IsErrorType());
return(false);
}
// 13.1.1 Identity conversion
//
// An identity conversion converts from any type to the same type. This conversion exists only
// such that an entity that already has a required type can be said to be convertible to that type.
if (typeSrc == typeDest &&
((flags & CONVERTTYPE.ISEXPLICIT) == 0 || (!typeSrc.isPredefType(PredefinedType.PT_FLOAT) && !typeSrc.isPredefType(PredefinedType.PT_DOUBLE))))
{
if (needsExprDest)
{
exprDest = exprSrc;
}
return(true);
}
if (typeDest.IsNullableType())
{
return(BindNubConversion(typeDest.AsNullableType()));
}
if (typeSrc.IsNullableType())
{
return(bindImplicitConversionFromNullable(typeSrc.AsNullableType()));
}
if ((flags & CONVERTTYPE.ISEXPLICIT) != 0)
{
flags |= CONVERTTYPE.NOUDC;
}
// Get the fundamental types of destination.
FUNDTYPE ftDest = typeDest.fundType();
Debug.Assert(ftDest != FUNDTYPE.FT_NONE || typeDest.IsParameterModifierType());
switch (typeSrc.GetTypeKind())
{
default:
VSFAIL("Bad type symbol kind");
break;
case TypeKind.TK_MethodGroupType:
if (exprSrc.isMEMGRP())
{
EXPRCALL outExpr;
bool retVal = binder.BindGrpConversion(exprSrc.asMEMGRP(), typeDest, needsExprDest, out outExpr, false);
exprDest = outExpr;
return(retVal);
}
return(false);
case TypeKind.TK_VoidType:
case TypeKind.TK_ErrorType:
case TypeKind.TK_ParameterModifierType:
case TypeKind.TK_ArgumentListType:
return(false);
case TypeKind.TK_NullType:
if (bindImplicitConversionFromNull())
{
return(true);
}
// If not, try user defined implicit conversions.
break;
case TypeKind.TK_ArrayType:
if (bindImplicitConversionFromArray())
{
return(true);
}
// If not, try user defined implicit conversions.
break;
case TypeKind.TK_PointerType:
if (bindImplicitConversionFromPointer())
{
return(true);
}
// If not, try user defined implicit conversions.
break;
case TypeKind.TK_TypeParameterType:
if (bindImplicitConversionFromTypeVar(typeSrc.AsTypeParameterType()))
{
return(true);
}
// If not, try user defined implicit conversions.
break;
case TypeKind.TK_AggregateType:
// TypeReference and ArgIterator can't be boxed (or converted to anything else)
if (typeSrc.isSpecialByRefType())
{
return(false);
}
if (bindImplicitConversionFromAgg(typeSrc.AsAggregateType()))
{
return(true);
}
// If not, try user defined implicit conversions.
break;
}
// !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
// RUNTIME BINDER ONLY CHANGE
// !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
//
// Every incoming dynamic operand should be implicitly convertible
// to any type that it is an instance of.
if (exprSrc != null &&
exprSrc.RuntimeObject != null &&
typeDest.AssociatedSystemType.IsInstanceOfType(exprSrc.RuntimeObject) &&
binder.GetSemanticChecker().CheckTypeAccess(typeDest, binder.Context.ContextForMemberLookup()))
{
if (needsExprDest)
{
binder.bindSimpleCast(exprSrc, exprTypeDest, out exprDest, exprSrc.flags & EXPRFLAG.EXF_CANTBENULL);
}
return(true);
}
// !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
// END RUNTIME BINDER ONLY CHANGE
// !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
// 13.1.8 User-defined implicit conversions
//
// A user-defined implicit conversion consists of an optional standard implicit conversion,
// followed by execution of a user-defined implicit conversion operator, followed by another
// optional standard implicit conversion. The exact rules for evaluating user-defined
// conversions are described in 13.4.3.
if (0 == (flags & CONVERTTYPE.NOUDC))
{
return(binder.bindUserDefinedConversion(exprSrc, typeSrc, typeDest, needsExprDest, out exprDest, true));
}
// No conversion was found.
return(false);
}
/***************************************************************************************************
Determines whether there is a wrapping conversion from typeSrc to typeDst
13.7 Conversions involving nullable types
The following terms are used in the subsequent sections:
* The term wrapping denotes the process of packaging a value, of type T, in an instance of type T?.
A value x of type T is wrapped to type T? by evaluating the expression new T?(x).
***************************************************************************************************/
public static bool FWrappingConv(CType typeSrc, CType typeDst)
{
return typeDst.IsNullableType() && typeSrc == typeDst.AsNullableType().GetUnderlyingType();
}
// Check the constraints of any type arguments in the given Type.
public static bool CheckConstraints(CSemanticChecker checker, ErrorHandling errHandling, CType type, CheckConstraintsFlags flags)
{
type = type.GetNakedType(false);
if (type.IsNullableType())
{
CType typeT = type.AsNullableType().GetAts(checker.GetErrorContext());
if (typeT != null)
type = typeT;
else
type = type.GetNakedType(true);
}
if (!type.IsAggregateType())
return true;
AggregateType ats = type.AsAggregateType();
if (ats.GetTypeArgsAll().size == 0)
{
// Common case: there are no type vars, so there are no constraints.
ats.fConstraintsChecked = true;
ats.fConstraintError = false;
return true;
}
if (ats.fConstraintsChecked)
{
// Already checked.
if (!ats.fConstraintError || (flags & CheckConstraintsFlags.NoDupErrors) != 0)
{
// No errors or no need to report errors again.
return !ats.fConstraintError;
}
}
TypeArray typeVars = ats.getAggregate().GetTypeVars();
TypeArray typeArgsThis = ats.GetTypeArgsThis();
TypeArray typeArgsAll = ats.GetTypeArgsAll();
Debug.Assert(typeVars.size == typeArgsThis.size);
if (!ats.fConstraintsChecked)
{
ats.fConstraintsChecked = true;
ats.fConstraintError = false;
}
// Check the outer type first. If CheckConstraintsFlags.Outer is not specified and the
// outer type has already been checked then don't bother checking it.
if (ats.outerType != null && ((flags & CheckConstraintsFlags.Outer) != 0 || !ats.outerType.fConstraintsChecked))
{
CheckConstraints(checker, errHandling, ats.outerType, flags);
ats.fConstraintError |= ats.outerType.fConstraintError;
}
if (typeVars.size > 0)
ats.fConstraintError |= !CheckConstraintsCore(checker, errHandling, ats.getAggregate(), typeVars, typeArgsThis, typeArgsAll, null, (flags & CheckConstraintsFlags.NoErrors));
// Now check type args themselves.
for (int i = 0; i < typeArgsThis.size; i++)
{
CType arg = typeArgsThis.Item(i).GetNakedType(true);
if (arg.IsAggregateType() && !arg.AsAggregateType().fConstraintsChecked)
{
CheckConstraints(checker, errHandling, arg.AsAggregateType(), flags | CheckConstraintsFlags.Outer);
if (arg.AsAggregateType().fConstraintError)
ats.fConstraintError = true;
}
}
return !ats.fConstraintError;
}
/*
Same as CanConvertArg1 but with the indices interchanged!
*/
private bool CanConvertArg2(BinOpArgInfo info, CType typeDst, out LiftFlags pgrflt,
out CType ptypeSig1, out CType ptypeSig2)
{
Debug.Assert(!typeDst.IsNullableType());
ptypeSig1 = null;
ptypeSig2 = null;
if (canConvert(info.arg2, typeDst))
pgrflt = LiftFlags.None;
else
{
pgrflt = LiftFlags.None;
if (!GetSymbolLoader().FCanLift())
return false;
typeDst = GetSymbolLoader().GetTypeManager().GetNullable(typeDst);
if (!canConvert(info.arg2, typeDst))
return false;
pgrflt = LiftFlags.Convert2;
}
ptypeSig2 = typeDst;
if (info.type1.IsNullableType())
{
pgrflt = pgrflt | LiftFlags.Lift1;
ptypeSig1 = GetSymbolLoader().GetTypeManager().GetNullable(info.typeRaw1);
}
else
ptypeSig1 = info.typeRaw1;
return true;
}
/////////////////////////////////////////////////////////////////////////////////
private void LiftArgument(EXPR pArgument, CType pParameterType, bool bConvertBeforeLift,
out EXPR ppLiftedArgument, out EXPR ppNonLiftedArgument)
{
EXPR pLiftedArgument = mustConvert(pArgument, pParameterType);
if (pLiftedArgument != pArgument)
{
MarkAsIntermediateConversion(pLiftedArgument);
}
EXPR pNonLiftedArgument = pArgument;
if (pParameterType.IsNullableType())
{
if (pNonLiftedArgument.isNull())
{
pNonLiftedArgument = mustCast(pNonLiftedArgument, pParameterType);
}
pNonLiftedArgument = mustCast(pNonLiftedArgument, pParameterType.AsNullableType().GetUnderlyingType());
if (bConvertBeforeLift)
{
MarkAsIntermediateConversion(pNonLiftedArgument);
}
}
else
{
pNonLiftedArgument = pLiftedArgument;
}
ppLiftedArgument = pLiftedArgument;
ppNonLiftedArgument = pNonLiftedArgument;
}
public bool HasImplicitBoxingConversion(CType pSource, CType pDest)
{
Debug.Assert(pSource != null);
Debug.Assert(pDest != null);
// Certain type parameter conversions are classified as boxing conversions.
if (pSource.IsTypeParameterType() &&
HasImplicitBoxingTypeParameterConversion(pSource.AsTypeParameterType(), pDest))
{
return true;
}
// The rest of the boxing conversions only operate when going from a value type
// to a reference type.
if (!pSource.IsValType() || !pDest.IsRefType())
{
return false;
}
// A boxing conversion exists from a nullable type to a reference type
// if and only if a boxing conversion exists from the underlying type.
if (pSource.IsNullableType())
{
return HasImplicitBoxingConversion(pSource.AsNullableType().GetUnderlyingType(), pDest);
}
// A boxing conversion exists from any non-nullable value type to object,
// to System.ValueType, and to any interface type implemented by the
// non-nullable value type. Furthermore, an enum type can be converted
// to the type System.Enum.
// We set the base class of the structs to System.ValueType, System.Enum, etc,
// so we can just check here.
if (IsBaseClass(pSource, pDest))
{
return true;
}
if (HasAnyBaseInterfaceConversion(pSource, pDest))
{
return true;
}
return false;
}
public bool HasImplicitReferenceConversion(CType pSource, CType pDest)
{
Debug.Assert(pSource != null);
Debug.Assert(pDest != null);
// The implicit reference conversions are:
// * From any reference type to Object.
if (pSource.IsRefType() && pDest.isPredefType(PredefinedType.PT_OBJECT))
{
return true;
}
// * From any class type S to any class type T provided S is derived from T.
if (pSource.isClassType() && pDest.isClassType() && IsBaseClass(pSource, pDest))
{
return true;
}
// ORIGINAL RULES:
// // * From any class type S to any interface type T provided S implements T.
// if (pSource.isClassType() && pDest.isInterfaceType() && IsBaseInterface(pSource, pDest))
// {
// return true;
// }
// // * from any interface type S to any interface type T, provided S is derived from T.
// if (pSource.isInterfaceType() && pDest.isInterfaceType() && IsBaseInterface(pSource, pDest))
// {
// return true;
// }
// VARIANCE EXTENSIONS:
// * From any class type S to any interface type T provided S implements an interface
// convertible to T.
// * From any interface type S to any interface type T provided S implements an interface
// convertible to T.
// * From any interface type S to any interface type T provided S is not T and S is
// an interface convertible to T.
if (pSource.isClassType() && pDest.isInterfaceType() && HasAnyBaseInterfaceConversion(pSource, pDest))
{
return true;
}
if (pSource.isInterfaceType() && pDest.isInterfaceType() && HasAnyBaseInterfaceConversion(pSource, pDest))
{
return true;
}
if (pSource.isInterfaceType() && pDest.isInterfaceType() && pSource != pDest &&
HasInterfaceConversion(pSource.AsAggregateType(), pDest.AsAggregateType()))
{
return true;
}
// * From an array type S with an element type SE to an array type T with element type TE
// provided that all of the following are true:
// * S and T differ only in element type. In other words, S and T have the same number of dimensions.
// * Both SE and TE are reference types.
// * An implicit reference conversion exists from SE to TE.
if (pSource.IsArrayType() && pDest.IsArrayType() &&
HasCovariantArrayConversion(pSource.AsArrayType(), pDest.AsArrayType()))
{
return true;
}
// * From any array type to System.Array or any interface implemented by System.Array.
if (pSource.IsArrayType() && (pDest.isPredefType(PredefinedType.PT_ARRAY) ||
IsBaseInterface(GetReqPredefType(PredefinedType.PT_ARRAY, false), pDest)))
{
return true;
}
// * From a single-dimensional array type S[] to IList<T> and its base
// interfaces, provided that there is an implicit identity or reference
// conversion from S to T.
if (pSource.IsArrayType() && HasArrayConversionToInterface(pSource.AsArrayType(), pDest))
{
return true;
}
// * From any delegate type to System.Delegate
//
// SPEC OMISSION:
//
// The spec should actually say
//
// * From any delegate type to System.Delegate
// * From any delegate type to System.MulticastDelegate
// * From any delegate type to any interface implemented by System.MulticastDelegate
if (pSource.isDelegateType() &&
(pDest.isPredefType(PredefinedType.PT_MULTIDEL) ||
pDest.isPredefType(PredefinedType.PT_DELEGATE) ||
IsBaseInterface(GetReqPredefType(PredefinedType.PT_MULTIDEL, false), pDest)))
{
return true;
}
// VARIANCE EXTENSION:
// * From any delegate type S to a delegate type T provided S is not T and
// S is a delegate convertible to T
if (pSource.isDelegateType() && pDest.isDelegateType() &&
HasDelegateConversion(pSource.AsAggregateType(), pDest.AsAggregateType()))
{
return true;
}
// * From the null literal to any reference type
// NOTE: We extend the specification here. The C# 3.0 spec does not describe
// a "null type". Rather, it says that the null literal is typeless, and is
// convertible to any reference or nullable type. However, the C# 2.0 and 3.0
// implementations have a "null type" which some expressions other than the
// null literal may have. (For example, (null??null), which is also an
// extension to the specification.)
if (pSource.IsNullType() && pDest.IsRefType())
{
return true;
}
if (pSource.IsNullType() && pDest.IsNullableType())
{
return true;
}
// * Implicit conversions involving type parameters that are known to be reference types.
if (pSource.IsTypeParameterType() &&
HasImplicitReferenceTypeParameterConversion(pSource.AsTypeParameterType(), pDest))
{
return true;
}
return false;
}
public bool IsBaseClass(CType pDerived, CType pBase)
{
Debug.Assert(pDerived != null);
Debug.Assert(pBase != null);
// A base class has got to be a class. The derived type might be a struct.
if (!pBase.isClassType())
{
return false;
}
if (pDerived.IsNullableType())
{
pDerived = pDerived.AsNullableType().GetAts(ErrorContext);
if (pDerived == null)
{
return false;
}
}
if (!pDerived.IsAggregateType())
{
return false;
}
AggregateType atsDer = pDerived.AsAggregateType();
AggregateType atsBase = pBase.AsAggregateType();
AggregateType atsCur = atsDer.GetBaseClass();
while (atsCur != null)
{
if (atsCur == atsBase)
{
return true;
}
atsCur = atsCur.GetBaseClass();
}
return false;
}
// It would be nice to make this a virtual method on typeSym.
public AggregateType GetAggTypeSym(CType typeSym)
{
Debug.Assert(typeSym != null);
Debug.Assert(typeSym.IsAggregateType() ||
typeSym.IsTypeParameterType() ||
typeSym.IsArrayType() ||
typeSym.IsNullableType());
switch (typeSym.GetTypeKind())
{
case TypeKind.TK_AggregateType:
return typeSym.AsAggregateType();
case TypeKind.TK_ArrayType:
return GetReqPredefType(PredefinedType.PT_ARRAY);
case TypeKind.TK_TypeParameterType:
return typeSym.AsTypeParameterType().GetEffectiveBaseClass();
case TypeKind.TK_NullableType:
return typeSym.AsNullableType().GetAts(ErrorContext);
}
Debug.Assert(false, "Bad typeSym!");
return null;
}
public bool IsNonNullableValueType()
{
return((_constraints & SpecCons.Val) > 0 || _bHasValBound && !_pDeducedBaseClass.IsNullableType());
}
private static bool CheckSingleConstraint(CSemanticChecker checker, ErrorHandling errHandling, Symbol symErr, TypeParameterType var, CType arg, TypeArray typeArgsCls, TypeArray typeArgsMeth, CheckConstraintsFlags flags)
{
bool fReportErrors = 0 == (flags & CheckConstraintsFlags.NoErrors);
if (arg.IsOpenTypePlaceholderType())
{
return true;
}
if (arg.IsErrorType())
{
// Error should have been reported previously.
return false;
}
if (checker.CheckBogus(arg))
{
if (fReportErrors)
{
errHandling.ErrorRef(ErrorCode.ERR_BogusType, arg);
}
return false;
}
if (arg.IsPointerType() || arg.isSpecialByRefType())
{
if (fReportErrors)
{
errHandling.Error(ErrorCode.ERR_BadTypeArgument, arg);
}
return false;
}
if (arg.isStaticClass())
{
if (fReportErrors)
{
checker.ReportStaticClassError(null, arg, ErrorCode.ERR_GenericArgIsStaticClass);
}
return false;
}
bool fError = false;
if (var.HasRefConstraint() && !arg.IsRefType())
{
if (fReportErrors)
{
errHandling.ErrorRef(ErrorCode.ERR_RefConstraintNotSatisfied, symErr, new ErrArgNoRef(var), arg);
}
fError = true;
}
TypeArray bnds = checker.GetSymbolLoader().GetTypeManager().SubstTypeArray(var.GetBounds(), typeArgsCls, typeArgsMeth);
int itypeMin = 0;
if (var.HasValConstraint())
{
// If we have a type variable that is constrained to a value type, then we
// want to check if its a nullable type, so that we can report the
// constraint error below. In order to do this however, we need to check
// that either the type arg is not a value type, or it is a nullable type.
//
// To check whether or not its a nullable type, we need to get the resolved
// bound from the type argument and check against that.
bool bIsValueType = arg.IsValType();
bool bIsNullable = arg.IsNullableType();
if (bIsValueType && arg.IsTypeParameterType())
{
TypeArray pArgBnds = arg.AsTypeParameterType().GetBounds();
if (pArgBnds.size > 0)
{
bIsNullable = pArgBnds.Item(0).IsNullableType();
}
}
if (!bIsValueType || bIsNullable)
{
if (fReportErrors)
{
errHandling.ErrorRef(ErrorCode.ERR_ValConstraintNotSatisfied, symErr, new ErrArgNoRef(var), arg);
}
fError = true;
}
// Since FValCon() is set it is redundant to check System.ValueType as well.
if (bnds.size != 0 && bnds.Item(0).isPredefType(PredefinedType.PT_VALUE))
{
itypeMin = 1;
}
}
for (int j = itypeMin; j < bnds.size; j++)
{
CType typeBnd = bnds.Item(j);
if (!SatisfiesBound(checker, arg, typeBnd))
{
if (fReportErrors)
{
// The bound isn't satisfied because of a constaint type. Explain to the user why not.
// There are 4 main cases, based on the type of the supplied type argument:
// - reference type, or type parameter known to be a reference type
// - nullable type, from which there is a boxing conversion to the constraint type(see below for details)
// - type varaiable
// - value type
// These cases are broken out because: a) The sets of conversions which can be used
// for constraint satisfaction is different based on the type argument supplied,
// and b) Nullable is one funky type, and user's can use all the help they can get
// when using it.
ErrorCode error;
if (arg.IsRefType())
{
// A reference type can only satisfy bounds to types
// to which they have an implicit reference conversion
error = ErrorCode.ERR_GenericConstraintNotSatisfiedRefType;
}
else if (arg.IsNullableType() && checker.GetSymbolLoader().HasBaseConversion(arg.AsNullableType().GetUnderlyingType(), typeBnd)) // This is inlining FBoxingConv
{
// nullable types do not satisfy bounds to every type that they are boxable to
// They only satisfy bounds of object and ValueType
if (typeBnd.isPredefType(PredefinedType.PT_ENUM) || arg.AsNullableType().GetUnderlyingType() == typeBnd)
{
// Nullable types don't satisfy bounds of EnumType, or the underlying type of the enum
// even though the conversion from Nullable to these types is a boxing conversion
// This is a rare case, because these bounds can never be directly stated ...
// These bounds can only occur when one type paramter is constrained to a second type parameter
// and the second type parameter is instantiated with Enum or the underlying type of the first type
// parameter
error = ErrorCode.ERR_GenericConstraintNotSatisfiedNullableEnum;
}
else
{
// Nullable types don't satisfy the bounds of any interface type
// even when there is a boxing conversion from the Nullable type to
// the interface type. This will be a relatively common scenario
// so we cal it out separately from the previous case.
Debug.Assert(typeBnd.isInterfaceType());
error = ErrorCode.ERR_GenericConstraintNotSatisfiedNullableInterface;
}
}
else if (arg.IsTypeParameterType())
{
// Type variables can satisfy bounds through boxing and type variable conversions
Debug.Assert(!arg.IsRefType());
error = ErrorCode.ERR_GenericConstraintNotSatisfiedTyVar;
}
else
{
// Value types can only satisfy bounds through boxing conversions.
// Note that the exceptional case of Nullable types and boxing is handled above.
error = ErrorCode.ERR_GenericConstraintNotSatisfiedValType;
}
errHandling.Error(error, new ErrArgRef(symErr), new ErrArg(typeBnd, ErrArgFlags.Unique), var, new ErrArgRef(arg, ErrArgFlags.Unique));
}
fError = true;
}
}
// Check the newable constraint.
if (!var.HasNewConstraint() || arg.IsValType())
{
return !fError;
}
if (arg.isClassType())
{
AggregateSymbol agg = arg.AsAggregateType().getAggregate();
// Due to late binding nature of IDE created symbols, the AggregateSymbol might not
// have all the information necessary yet, if it is not fully bound.
// by calling LookupAggMember, it will ensure that we will update all the
// information necessary at least for the given method.
checker.GetSymbolLoader().LookupAggMember(checker.GetNameManager().GetPredefName(PredefinedName.PN_CTOR), agg, symbmask_t.MASK_ALL);
if (agg.HasPubNoArgCtor() && !agg.IsAbstract())
{
return !fError;
}
}
else if (arg.IsTypeParameterType() && arg.AsTypeParameterType().HasNewConstraint())
{
return !fError;
}
if (fReportErrors)
{
errHandling.ErrorRef(ErrorCode.ERR_NewConstraintNotSatisfied, symErr, new ErrArgNoRef(var), arg);
}
return false;
}
/***************************************************************************************************
* Determines whether there is a wrapping conversion from typeSrc to typeDst
*
* 13.7 Conversions involving nullable types
*
* The following terms are used in the subsequent sections:
* The term wrapping denotes the process of packaging a value, of type T, in an instance of type T?.
* A value x of type T is wrapped to type T? by evaluating the expression new T?(x).
***************************************************************************************************/
public static bool FWrappingConv(CType typeSrc, CType typeDst)
{
return(typeDst.IsNullableType() && typeSrc == typeDst.AsNullableType().GetUnderlyingType());
}
/////////////////////////////////////////////////////////////////////////////////
private static EXPR GenerateOptionalArgument(
SymbolLoader symbolLoader,
ExprFactory exprFactory,
MethodOrPropertySymbol methprop,
CType type,
int index)
{
CType pParamType = type;
CType pRawParamType = type.IsNullableType() ? type.AsNullableType().GetUnderlyingType() : type;
EXPR optionalArgument = null;
if (methprop.HasDefaultParameterValue(index))
{
CType pConstValType = methprop.GetDefaultParameterValueConstValType(index);
CONSTVAL cv = methprop.GetDefaultParameterValue(index);
if (pConstValType.isPredefType(PredefinedType.PT_DATETIME) &&
(pRawParamType.isPredefType(PredefinedType.PT_DATETIME) || pRawParamType.isPredefType(PredefinedType.PT_OBJECT) || pRawParamType.isPredefType(PredefinedType.PT_VALUE)))
{
// This is the specific case where we want to create a DateTime
// but the constval that stores it is a long.
AggregateType dateTimeType = symbolLoader.GetReqPredefType(PredefinedType.PT_DATETIME);
optionalArgument = exprFactory.CreateConstant(dateTimeType, new CONSTVAL(DateTime.FromBinary(cv.longVal)));
}
else if (pConstValType.isSimpleOrEnumOrString())
{
// In this case, the constval is a simple type (all the numerics, including
// decimal), or an enum or a string. This covers all the substantial values,
// and everything else that can be encoded is just null or default(something).
// For enum parameters, we create a constant of the enum type. For everything
// else, we create the appropriate constant.
if (pRawParamType.isEnumType() && pConstValType == pRawParamType.underlyingType())
{
optionalArgument = exprFactory.CreateConstant(pRawParamType, cv);
}
else
{
optionalArgument = exprFactory.CreateConstant(pConstValType, cv);
}
}
else if ((pParamType.IsRefType() || pParamType.IsNullableType()) && cv.IsNullRef())
{
// We have an "= null" default value with a reference type or a nullable type.
optionalArgument = exprFactory.CreateNull();
}
else
{
// We have a default value that is encoded as a nullref, and that nullref is
// interpreted as default(something). For instance, the pParamType could be
// a type parameter type or a non-simple value type.
optionalArgument = exprFactory.CreateZeroInit(pParamType);
}
}
else
{
// There was no default parameter specified, so generally use default(T),
// except for some cases when the parameter type in metatdata is object.
if (pParamType.isPredefType(PredefinedType.PT_OBJECT))
{
if (methprop.MarshalAsObject(index))
{
// For [opt] parameters of type object, if we have marshal(iunknown),
// marshal(idispatch), or marshal(interface), then we emit a null.
optionalArgument = exprFactory.CreateNull();
}
else
{
// Otherwise, we generate Type.Missing
AggregateSymbol agg = symbolLoader.GetOptPredefAgg(PredefinedType.PT_MISSING);
Name name = symbolLoader.GetNameManager().GetPredefinedName(PredefinedName.PN_CAP_VALUE);
FieldSymbol field = symbolLoader.LookupAggMember(name, agg, symbmask_t.MASK_FieldSymbol).AsFieldSymbol();
FieldWithType fwt = new FieldWithType(field, agg.getThisType());
EXPRFIELD exprField = exprFactory.CreateField(0, agg.getThisType(), null, 0, fwt, null);
if (agg.getThisType() != type)
{
optionalArgument = exprFactory.CreateCast(0, type, exprField);
}
else
{
optionalArgument = exprField;
}
}
}
else
{
// Every type aside from object that doesn't have a default value gets
// its default value.
optionalArgument = exprFactory.CreateZeroInit(pParamType);
}
}
Debug.Assert(optionalArgument != null);
optionalArgument.IsOptionalArgument = true;
return optionalArgument;
}
////////////////////////////////////////////////////////////////////////////////
// For a base call we need to remap from the virtual to the specific override
// to invoke. This is also used to map a virtual on pObject (like ToString) to
// the specific override when the pObject is a simple type (int, bool, char,
// etc). In these cases it is safe to assume that any override won't later be
// removed.... We start searching from "typeObj" up the superclass hierarchy
// until we find a method with an exact signature match.
public static void RemapToOverride(SymbolLoader symbolLoader, SymWithType pswt, CType typeObj)
{
// For a property/indexer we remap the accessors, not the property/indexer.
// Since every event has both accessors we remap the event instead of the accessors.
Debug.Assert(pswt && (pswt.Sym.IsMethodSymbol() || pswt.Sym.IsEventSymbol() || pswt.Sym.IsMethodOrPropertySymbol()));
Debug.Assert(typeObj != null);
// Don't remap static or interface methods.
if (typeObj.IsNullableType())
{
typeObj = typeObj.AsNullableType().GetAts(symbolLoader.GetErrorContext());
if (typeObj == null)
{
VSFAIL("Why did GetAts return null?");
return;
}
}
// Don't remap non-virtual members
if (!typeObj.IsAggregateType() || typeObj.isInterfaceType() || !pswt.Sym.IsVirtual())
{
return;
}
symbmask_t mask = pswt.Sym.mask();
AggregateType atsObj = typeObj.AsAggregateType();
// Search for an override version of the method.
while (atsObj != null && atsObj.getAggregate() != pswt.Sym.parent)
{
for (Symbol symT = symbolLoader.LookupAggMember(pswt.Sym.name, atsObj.getAggregate(), mask);
symT != null;
symT = symbolLoader.LookupNextSym(symT, atsObj.getAggregate(), mask))
{
if (symT.IsOverride() && (symT.SymBaseVirtual() == pswt.Sym || symT.SymBaseVirtual() == pswt.Sym.SymBaseVirtual()))
{
pswt.Set(symT, atsObj);
return;
}
}
atsObj = atsObj.GetBaseClass();
}
}
// !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
// RUNTIME BINDER ONLY CHANGE
// !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
internal bool GetBestAccessibleType(CSemanticChecker semanticChecker, BindingContext bindingContext, CType typeSrc, out CType typeDst)
{
// This method implements the "best accessible type" algorithm for determining the type
// of untyped arguments in the runtime binder. It is also used in method type inference
// to fix type arguments to types that are accessible.
// The new type is returned in an out parameter. The result will be true (and the out param
// non-null) only when the algorithm could find a suitable accessible type.
Debug.Assert(semanticChecker != null);
Debug.Assert(bindingContext != null);
Debug.Assert(typeSrc != null);
typeDst = null;
if (semanticChecker.CheckTypeAccess(typeSrc, bindingContext.ContextForMemberLookup()))
{
// If we already have an accessible type, then use it. This is the terminal point of the recursion.
typeDst = typeSrc;
return true;
}
// These guys have no accessibility concerns.
Debug.Assert(!typeSrc.IsVoidType() && !typeSrc.IsErrorType() && !typeSrc.IsTypeParameterType());
if (typeSrc.IsParameterModifierType() || typeSrc.IsPointerType())
{
// We cannot vary these.
return false;
}
CType intermediateType;
if ((typeSrc.isInterfaceType() || typeSrc.isDelegateType()) && TryVarianceAdjustmentToGetAccessibleType(semanticChecker, bindingContext, typeSrc.AsAggregateType(), out intermediateType))
{
// If we have an interface or delegate type, then it can potentially be varied by its type arguments
// to produce an accessible type, and if that's the case, then return that.
// Example: IEnumerable<PrivateConcreteFoo> --> IEnumerable<PublicAbstractFoo>
typeDst = intermediateType;
Debug.Assert(semanticChecker.CheckTypeAccess(typeDst, bindingContext.ContextForMemberLookup()));
return true;
}
if (typeSrc.IsArrayType() && TryArrayVarianceAdjustmentToGetAccessibleType(semanticChecker, bindingContext, typeSrc.AsArrayType(), out intermediateType))
{
// Similarly to the interface and delegate case, arrays are covariant in their element type and
// so we can potentially produce an array type that is accessible.
// Example: PrivateConcreteFoo[] --> PublicAbstractFoo[]
typeDst = intermediateType;
Debug.Assert(semanticChecker.CheckTypeAccess(typeDst, bindingContext.ContextForMemberLookup()));
return true;
}
if (typeSrc.IsNullableType())
{
// We have an inaccessible nullable type, which means that the best we can do is System.ValueType.
typeDst = this.GetOptPredefAgg(PredefinedType.PT_VALUE).getThisType();
Debug.Assert(semanticChecker.CheckTypeAccess(typeDst, bindingContext.ContextForMemberLookup()));
return true;
}
if (typeSrc.IsArrayType())
{
// We have an inaccessible array type for which we could not earlier find a better array type
// with a covariant conversion, so the best we can do is System.Array.
typeDst = this.GetReqPredefAgg(PredefinedType.PT_ARRAY).getThisType();
Debug.Assert(semanticChecker.CheckTypeAccess(typeDst, bindingContext.ContextForMemberLookup()));
return true;
}
Debug.Assert(typeSrc.IsAggregateType());
if (typeSrc.IsAggregateType())
{
// We have an AggregateType, so recurse on its base class.
AggregateType aggType = typeSrc.AsAggregateType();
AggregateType baseType = aggType.GetBaseClass();
if (baseType == null)
{
// This happens with interfaces, for instance. But in that case, the
// conversion to object does exist, is an implicit reference conversion,
// and so we will use it.
baseType = this.GetReqPredefAgg(PredefinedType.PT_OBJECT).getThisType();
}
return GetBestAccessibleType(semanticChecker, bindingContext, baseType, out typeDst);
}
return false;
}
/*
* BindExplicitConversion
*
* This is a complex routine with complex parameter. Generally, this should
* be called through one of the helper methods that insulates you
* from the complexity of the interface. This routine handles all the logic
* associated with explicit conversions.
*
* Note that this function calls BindImplicitConversion first, so the main
* logic is only concerned with conversions that can be made explicitly, but
* not implicitly.
*/
public bool Bind()
{
// To test for a standard conversion, call canConvert(exprSrc, typeDest, STANDARDANDCONVERTTYPE.NOUDC) and
// canConvert(typeDest, typeSrc, STANDARDANDCONVERTTYPE.NOUDC).
Debug.Assert((_flags & CONVERTTYPE.STANDARD) == 0);
// 13.2 Explicit conversions
//
// The following conversions are classified as explicit conversions:
//
// * All implicit conversions
// * Explicit numeric conversions
// * Explicit enumeration conversions
// * Explicit reference conversions
// * Explicit interface conversions
// * Unboxing conversions
// * Explicit type parameter conversions
// * User-defined explicit conversions
// * Explicit nullable conversions
// * Lifted user-defined explicit conversions
//
// Explicit conversions can occur in cast expressions (14.6.6).
//
// The explicit conversions that are not implicit conversions are conversions that cannot be
// proven always to succeed, conversions that are known possibly to lose information, and
// conversions across domains of types sufficiently different to merit explicit notation.
// The set of explicit conversions includes all implicit conversions.
// Don't try user-defined conversions now because we'll try them again later.
if (_binder.BindImplicitConversion(_exprSrc, _typeSrc, _exprTypeDest, _pDestinationTypeForLambdaErrorReporting, _needsExprDest, out _exprDest, _flags | CONVERTTYPE.ISEXPLICIT))
{
return(true);
}
if (_typeSrc == null || _typeDest == null || _typeSrc.IsErrorType() ||
_typeDest.IsErrorType() || _typeDest.IsNeverSameType())
{
return(false);
}
if (_typeDest.IsNullableType())
{
// This is handled completely by BindImplicitConversion.
return(false);
}
if (_typeSrc.IsNullableType())
{
return(bindExplicitConversionFromNub());
}
if (bindExplicitConversionFromArrayToIList())
{
return(true);
}
// if we were casting an integral constant to another constant type,
// then, if the constant were in range, then the above call would have succeeded.
// But it failed, and so we know that the constant is not in range
switch (_typeDest.GetTypeKind())
{
default:
VSFAIL("Bad type kind");
return(false);
case TypeKind.TK_VoidType:
return(false); // Can't convert to a method group or anon method.
case TypeKind.TK_NullType:
return(false); // Can never convert TO the null type.
case TypeKind.TK_TypeParameterType:
if (bindExplicitConversionToTypeVar())
{
return(true);
}
break;
case TypeKind.TK_ArrayType:
if (bindExplicitConversionToArray(_typeDest.AsArrayType()))
{
return(true);
}
break;
case TypeKind.TK_PointerType:
if (bindExplicitConversionToPointer())
{
return(true);
}
break;
case TypeKind.TK_AggregateType:
{
AggCastResult result = bindExplicitConversionToAggregate(_typeDest.AsAggregateType());
if (result == AggCastResult.Success)
{
return(true);
}
if (result == AggCastResult.Abort)
{
return(false);
}
break;
}
}
// No built-in conversion was found. Maybe a user-defined conversion?
if (0 == (_flags & CONVERTTYPE.NOUDC))
{
return(_binder.bindUserDefinedConversion(_exprSrc, _typeSrc, _typeDest, _needsExprDest, out _exprDest, false));
}
return(false);
}
////////////////////////////////////////////////////////////////////////////////
private bool ExactNullableInference(CType pSource, CType pDest)
{
// SPEC: Otherwise, if U is the CType U1? and V is the CType V1?
// SPEC: then an exact inference is made from U to V.
if (!pSource.IsNullableType() || !pDest.IsNullableType())
{
return false;
}
ExactInference(pSource.AsNullableType().GetUnderlyingType(),
pDest.AsNullableType().GetUnderlyingType());
return true;
}
protected bool IsNullableValueType(CType pType)
{
if (pType.IsNullableType())
{
CType pStrippedType = pType.StripNubs();
return pStrippedType.IsAggregateType() && pStrippedType.AsAggregateType().getAggregate().IsValueType();
}
return false;
}
// Check the constraints of any type arguments in the given Type.
public static bool CheckConstraints(CSemanticChecker checker, ErrorHandling errHandling, CType type, CheckConstraintsFlags flags)
{
type = type.GetNakedType(false);
if (type.IsNullableType())
{
CType typeT = type.AsNullableType().GetAts(checker.GetErrorContext());
if (typeT != null)
{
type = typeT;
}
else
{
type = type.GetNakedType(true);
}
}
if (!type.IsAggregateType())
{
return(true);
}
AggregateType ats = type.AsAggregateType();
if (ats.GetTypeArgsAll().Count == 0)
{
// Common case: there are no type vars, so there are no constraints.
ats.fConstraintsChecked = true;
ats.fConstraintError = false;
return(true);
}
if (ats.fConstraintsChecked)
{
// Already checked.
if (!ats.fConstraintError || (flags & CheckConstraintsFlags.NoDupErrors) != 0)
{
// No errors or no need to report errors again.
return(!ats.fConstraintError);
}
}
TypeArray typeVars = ats.getAggregate().GetTypeVars();
TypeArray typeArgsThis = ats.GetTypeArgsThis();
TypeArray typeArgsAll = ats.GetTypeArgsAll();
Debug.Assert(typeVars.Count == typeArgsThis.Count);
if (!ats.fConstraintsChecked)
{
ats.fConstraintsChecked = true;
ats.fConstraintError = false;
}
// Check the outer type first. If CheckConstraintsFlags.Outer is not specified and the
// outer type has already been checked then don't bother checking it.
if (ats.outerType != null && ((flags & CheckConstraintsFlags.Outer) != 0 || !ats.outerType.fConstraintsChecked))
{
CheckConstraints(checker, errHandling, ats.outerType, flags);
ats.fConstraintError |= ats.outerType.fConstraintError;
}
if (typeVars.Count > 0)
{
ats.fConstraintError |= !CheckConstraintsCore(checker, errHandling, ats.getAggregate(), typeVars, typeArgsThis, typeArgsAll, null, (flags & CheckConstraintsFlags.NoErrors));
}
// Now check type args themselves.
for (int i = 0; i < typeArgsThis.Count; i++)
{
CType arg = typeArgsThis[i].GetNakedType(true);
if (arg.IsAggregateType() && !arg.AsAggregateType().fConstraintsChecked)
{
CheckConstraints(checker, errHandling, arg.AsAggregateType(), flags | CheckConstraintsFlags.Outer);
if (arg.AsAggregateType().fConstraintError)
{
ats.fConstraintError = true;
}
}
}
return(!ats.fConstraintError);
}
//
// SymbolLoader forwarders (end)
/////////////////////////////////////////////////////////////////////////////////
//
// Utility methods
//
protected ACCESSERROR CheckAccessCore(Symbol symCheck, AggregateType atsCheck, Symbol symWhere, CType typeThru)
{
Debug.Assert(symCheck != null);
Debug.Assert(atsCheck == null || symCheck.parent == atsCheck.getAggregate());
Debug.Assert(typeThru == null ||
typeThru.IsAggregateType() ||
typeThru.IsTypeParameterType() ||
typeThru.IsArrayType() ||
typeThru.IsNullableType() ||
typeThru.IsErrorType());
switch (symCheck.GetAccess())
{
default:
throw Error.InternalCompilerError();
//return ACCESSERROR.ACCESSERROR_NOACCESS;
case ACCESS.ACC_UNKNOWN:
return(ACCESSERROR.ACCESSERROR_NOACCESS);
case ACCESS.ACC_PUBLIC:
return(ACCESSERROR.ACCESSERROR_NOERROR);
case ACCESS.ACC_PRIVATE:
case ACCESS.ACC_PROTECTED:
if (symWhere == null)
{
return(ACCESSERROR.ACCESSERROR_NOACCESS);
}
break;
case ACCESS.ACC_INTERNAL:
case ACCESS.ACC_INTERNALPROTECTED: // Check internal, then protected.
if (symWhere == null)
{
return(ACCESSERROR.ACCESSERROR_NOACCESS);
}
if (symWhere.SameAssemOrFriend(symCheck))
{
return(ACCESSERROR.ACCESSERROR_NOERROR);
}
if (symCheck.GetAccess() == ACCESS.ACC_INTERNAL)
{
return(ACCESSERROR.ACCESSERROR_NOACCESS);
}
break;
}
// Should always have atsCheck for private and protected access check.
// We currently don't need it since access doesn't respect instantiation.
// We just use symWhere.parent.AsAggregateSymbol() instead.
AggregateSymbol aggCheck = symCheck.parent.AsAggregateSymbol();
// Find the inner-most enclosing AggregateSymbol.
AggregateSymbol aggWhere = null;
for (Symbol symT = symWhere; symT != null; symT = symT.parent)
{
if (symT.IsAggregateSymbol())
{
aggWhere = symT.AsAggregateSymbol();
break;
}
if (symT.IsAggregateDeclaration())
{
aggWhere = symT.AsAggregateDeclaration().Agg();
break;
}
}
if (aggWhere == null)
{
return(ACCESSERROR.ACCESSERROR_NOACCESS);
}
// First check for private access.
for (AggregateSymbol agg = aggWhere; agg != null; agg = agg.GetOuterAgg())
{
if (agg == aggCheck)
{
return(ACCESSERROR.ACCESSERROR_NOERROR);
}
}
if (symCheck.GetAccess() == ACCESS.ACC_PRIVATE)
{
return(ACCESSERROR.ACCESSERROR_NOACCESS);
}
// Handle the protected case - which is the only real complicated one.
Debug.Assert(symCheck.GetAccess() == ACCESS.ACC_PROTECTED || symCheck.GetAccess() == ACCESS.ACC_INTERNALPROTECTED);
// Check if symCheck is in aggWhere or a base of aggWhere,
// or in an outer agg of aggWhere or a base of an outer agg of aggWhere.
AggregateType atsThru = null;
if (typeThru != null && !symCheck.isStatic)
{
atsThru = SymbolLoader.GetAggTypeSym(typeThru);
}
// Look for aggCheck among the base classes of aggWhere and outer aggs.
bool found = false;
for (AggregateSymbol agg = aggWhere; agg != null; agg = agg.GetOuterAgg())
{
Debug.Assert(agg != aggCheck); // We checked for this above.
// Look for aggCheck among the base classes of agg.
if (agg.FindBaseAgg(aggCheck))
{
found = true;
// aggCheck is a base class of agg. Check atsThru.
// For non-static protected access to be legal, atsThru must be an instantiation of
// agg or a CType derived from an instantiation of agg. In this case
// all that matters is that agg is in the base AggregateSymbol chain of atsThru. The
// actual AGGTYPESYMs involved don't matter.
if (atsThru == null || atsThru.getAggregate().FindBaseAgg(agg))
{
return(ACCESSERROR.ACCESSERROR_NOERROR);
}
}
}
// the CType in whice the method is being called has no relationship with the
// CType on which the method is defined surely this is NOACCESS and not NOACCESSTHRU
if (found == false)
{
return(ACCESSERROR.ACCESSERROR_NOACCESS);
}
return((atsThru == null) ? ACCESSERROR.ACCESSERROR_NOACCESS : ACCESSERROR.ACCESSERROR_NOACCESSTHRU);
}
private static bool isEnumToDecimalConversion(CType argtype, CType desttype)
{
CType strippedArgType = argtype.IsNullableType() ? argtype.StripNubs() : argtype;
CType strippedDestType = desttype.IsNullableType() ? desttype.StripNubs() : desttype;
return strippedArgType.isEnumType() && strippedDestType.isPredefType(PredefinedType.PT_DECIMAL);
}
private static bool CheckSingleConstraint(CSemanticChecker checker, ErrorHandling errHandling, Symbol symErr, TypeParameterType var, CType arg, TypeArray typeArgsCls, TypeArray typeArgsMeth, CheckConstraintsFlags flags)
{
bool fReportErrors = 0 == (flags & CheckConstraintsFlags.NoErrors);
if (arg.IsOpenTypePlaceholderType())
{
return(true);
}
if (arg.IsErrorType())
{
// Error should have been reported previously.
return(false);
}
if (checker.CheckBogus(arg))
{
if (fReportErrors)
{
errHandling.ErrorRef(ErrorCode.ERR_BogusType, arg);
}
return(false);
}
if (arg.IsPointerType() || arg.isSpecialByRefType())
{
if (fReportErrors)
{
errHandling.Error(ErrorCode.ERR_BadTypeArgument, arg);
}
return(false);
}
if (arg.isStaticClass())
{
if (fReportErrors)
{
checker.ReportStaticClassError(null, arg, ErrorCode.ERR_GenericArgIsStaticClass);
}
return(false);
}
bool fError = false;
if (var.HasRefConstraint() && !arg.IsRefType())
{
if (fReportErrors)
{
errHandling.ErrorRef(ErrorCode.ERR_RefConstraintNotSatisfied, symErr, new ErrArgNoRef(var), arg);
}
fError = true;
}
TypeArray bnds = checker.GetSymbolLoader().GetTypeManager().SubstTypeArray(var.GetBounds(), typeArgsCls, typeArgsMeth);
int itypeMin = 0;
if (var.HasValConstraint())
{
// If we have a type variable that is constrained to a value type, then we
// want to check if its a nullable type, so that we can report the
// constraint error below. In order to do this however, we need to check
// that either the type arg is not a value type, or it is a nullable type.
//
// To check whether or not its a nullable type, we need to get the resolved
// bound from the type argument and check against that.
bool bIsValueType = arg.IsValType();
bool bIsNullable = arg.IsNullableType();
if (bIsValueType && arg.IsTypeParameterType())
{
TypeArray pArgBnds = arg.AsTypeParameterType().GetBounds();
if (pArgBnds.Count > 0)
{
bIsNullable = pArgBnds[0].IsNullableType();
}
}
if (!bIsValueType || bIsNullable)
{
if (fReportErrors)
{
errHandling.ErrorRef(ErrorCode.ERR_ValConstraintNotSatisfied, symErr, new ErrArgNoRef(var), arg);
}
fError = true;
}
// Since FValCon() is set it is redundant to check System.ValueType as well.
if (bnds.Count != 0 && bnds[0].isPredefType(PredefinedType.PT_VALUE))
{
itypeMin = 1;
}
}
for (int j = itypeMin; j < bnds.Count; j++)
{
CType typeBnd = bnds[j];
if (!SatisfiesBound(checker, arg, typeBnd))
{
if (fReportErrors)
{
// The bound isn't satisfied because of a constraint type. Explain to the user why not.
// There are 4 main cases, based on the type of the supplied type argument:
// - reference type, or type parameter known to be a reference type
// - nullable type, from which there is a boxing conversion to the constraint type(see below for details)
// - type variable
// - value type
// These cases are broken out because: a) The sets of conversions which can be used
// for constraint satisfaction is different based on the type argument supplied,
// and b) Nullable is one funky type, and user's can use all the help they can get
// when using it.
ErrorCode error;
if (arg.IsRefType())
{
// A reference type can only satisfy bounds to types
// to which they have an implicit reference conversion
error = ErrorCode.ERR_GenericConstraintNotSatisfiedRefType;
}
else if (arg.IsNullableType() && checker.GetSymbolLoader().HasBaseConversion(arg.AsNullableType().GetUnderlyingType(), typeBnd)) // This is inlining FBoxingConv
{
// nullable types do not satisfy bounds to every type that they are boxable to
// They only satisfy bounds of object and ValueType
if (typeBnd.isPredefType(PredefinedType.PT_ENUM) || arg.AsNullableType().GetUnderlyingType() == typeBnd)
{
// Nullable types don't satisfy bounds of EnumType, or the underlying type of the enum
// even though the conversion from Nullable to these types is a boxing conversion
// This is a rare case, because these bounds can never be directly stated ...
// These bounds can only occur when one type paramter is constrained to a second type parameter
// and the second type parameter is instantiated with Enum or the underlying type of the first type
// parameter
error = ErrorCode.ERR_GenericConstraintNotSatisfiedNullableEnum;
}
else
{
// Nullable types don't satisfy the bounds of any interface type
// even when there is a boxing conversion from the Nullable type to
// the interface type. This will be a relatively common scenario
// so we cal it out separately from the previous case.
Debug.Assert(typeBnd.isInterfaceType());
error = ErrorCode.ERR_GenericConstraintNotSatisfiedNullableInterface;
}
}
else if (arg.IsTypeParameterType())
{
// Type variables can satisfy bounds through boxing and type variable conversions
Debug.Assert(!arg.IsRefType());
error = ErrorCode.ERR_GenericConstraintNotSatisfiedTyVar;
}
else
{
// Value types can only satisfy bounds through boxing conversions.
// Note that the exceptional case of Nullable types and boxing is handled above.
error = ErrorCode.ERR_GenericConstraintNotSatisfiedValType;
}
errHandling.Error(error, new ErrArgRef(symErr), new ErrArg(typeBnd, ErrArgFlags.Unique), var, new ErrArgRef(arg, ErrArgFlags.Unique));
}
fError = true;
}
}
// Check the newable constraint.
if (!var.HasNewConstraint() || arg.IsValType())
{
return(!fError);
}
if (arg.isClassType())
{
AggregateSymbol agg = arg.AsAggregateType().getAggregate();
// Due to late binding nature of IDE created symbols, the AggregateSymbol might not
// have all the information necessary yet, if it is not fully bound.
// by calling LookupAggMember, it will ensure that we will update all the
// information necessary at least for the given method.
checker.GetSymbolLoader().LookupAggMember(checker.GetNameManager().GetPredefName(PredefinedName.PN_CTOR), agg, symbmask_t.MASK_ALL);
if (agg.HasPubNoArgCtor() && !agg.IsAbstract())
{
return(!fError);
}
}
else if (arg.IsTypeParameterType() && arg.AsTypeParameterType().HasNewConstraint())
{
return(!fError);
}
if (fReportErrors)
{
errHandling.ErrorRef(ErrorCode.ERR_NewConstraintNotSatisfied, symErr, new ErrArgNoRef(var), arg);
}
return(false);
}
