public bool DependsOn(TypeParameterType pType)
{
Debug.Assert(pType != null);
// * If a type parameter T is used as a constraint for type parameter S
// then S depends on T.
// * If a type parameter S depends on a type parameter T and T depends on
// U then S depends on U.
TypeArray pConstraints = GetBounds();
for (int iConstraint = 0; iConstraint < pConstraints.size; ++iConstraint)
{
CType pConstraint = pConstraints.Item(iConstraint);
if (pConstraint == pType)
{
return true;
}
if (pConstraint.IsTypeParameterType() &&
pConstraint.AsTypeParameterType().DependsOn(pType))
{
return true;
}
}
return false;
}
public TypeArray typeVars; // All the type variables for a generic method, as declarations.
// If there is a type variable in the method which is used in no parameter,
// then inference must fail. Since this is expensive to check, we cache
// the result of the first call.
public bool InferenceMustFail()
{
if (_checkedInfMustFail)
{
return(_inferenceMustFail);
}
Debug.Assert(!_inferenceMustFail);
_checkedInfMustFail = true;
for (int ivar = 0; ivar < typeVars.Size; ivar++)
{
TypeParameterType var = typeVars.ItemAsTypeParameterType(ivar);
// See if type var is used in a parameter.
for (int ipar = 0; ; ipar++)
{
if (ipar >= Params.Size)
{
// This type variable is not in any parameter.
_inferenceMustFail = true;
return(true);
}
if (TypeManager.TypeContainsType(Params.Item(ipar), var))
{
break;
}
}
}
// All type variables are used in a parameter.
return(false);
}
//////////////////////////////////////////////////////////////////////////////
private static bool HasVariantConversion(AggregateType pSource, AggregateType pDest)
{
Debug.Assert(pSource != null);
Debug.Assert(pDest != null);
if (pSource == pDest)
{
return(true);
}
AggregateSymbol pAggSym = pSource.OwningAggregate;
if (pAggSym != pDest.OwningAggregate)
{
return(false);
}
TypeArray pTypeParams = pAggSym.GetTypeVarsAll();
TypeArray pSourceArgs = pSource.TypeArgsAll;
TypeArray pDestArgs = pDest.TypeArgsAll;
Debug.Assert(pTypeParams.Count == pSourceArgs.Count);
Debug.Assert(pTypeParams.Count == pDestArgs.Count);
for (int iParam = 0; iParam < pTypeParams.Count; ++iParam)
{
CType pSourceArg = pSourceArgs[iParam];
CType pDestArg = pDestArgs[iParam];
// If they're identical then this one is automatically good, so skip it.
if (pSourceArg == pDestArg)
{
continue;
}
TypeParameterType pParam = (TypeParameterType)pTypeParams[iParam];
if (pParam.Invariant)
{
return(false);
}
if (pParam.Covariant)
{
if (!HasImplicitReferenceConversion(pSourceArg, pDestArg))
{
return(false);
}
}
if (pParam.Contravariant)
{
if (!HasImplicitReferenceConversion(pDestArg, pSourceArg))
{
return(false);
}
}
}
return(true);
}
public TypeArray GetStdMethTyVarArray(int cTyVars)
{
TypeParameterType[] prgvar = new TypeParameterType[cTyVars];
for (int ivar = 0; ivar < cTyVars; ivar++)
{
prgvar[ivar] = GetStdMethTypeVar(ivar);
}
return(_BSymmgr.AllocParams(cTyVars, (CType[])prgvar));
}
public static bool HasGenericDelegateExplicitReferenceConversion(CType pSource, AggregateType pTarget)
{
if (!(pSource is AggregateType aggSrc) ||
!aggSrc.IsDelegateType ||
!pTarget.IsDelegateType ||
aggSrc.OwningAggregate != pTarget.OwningAggregate ||
SymbolLoader.HasIdentityOrImplicitReferenceConversion(aggSrc, pTarget))
{
return(false);
}
TypeArray pTypeParams = aggSrc.OwningAggregate.GetTypeVarsAll();
TypeArray pSourceArgs = aggSrc.TypeArgsAll;
TypeArray pTargetArgs = pTarget.TypeArgsAll;
Debug.Assert(pTypeParams.Count == pSourceArgs.Count);
Debug.Assert(pTypeParams.Count == pTargetArgs.Count);
for (int iParam = 0; iParam < pTypeParams.Count; ++iParam)
{
CType pSourceArg = pSourceArgs[iParam];
CType pTargetArg = pTargetArgs[iParam];
// If they're identical then this one is automatically good, so skip it.
// If we have an error type, then we're in some fault tolerance. Let it through.
if (pSourceArg == pTargetArg)
{
continue;
}
TypeParameterType pParam = (TypeParameterType)pTypeParams[iParam];
if (pParam.Invariant)
{
return(false);
}
if (pParam.Covariant)
{
if (!FExpRefConv(pSourceArg, pTargetArg))
{
return(false);
}
}
else if (pParam.Contravariant)
{
if (!pSourceArg.IsReferenceType || !pTargetArg.IsReferenceType)
{
return(false);
}
}
}
return(true);
}
//////////////////////////////////////////////////////////////////////////////
bool HasVariantConversion(AggregateType pSource, AggregateType pDest)
{
Debug.Assert(pSource != null);
Debug.Assert(pDest != null);
if (pSource == pDest)
{
return(true);
}
AggregateSymbol pAggSym = pSource.getAggregate();
if (pAggSym != pDest.getAggregate())
{
return(false);
}
TypeArray pTypeParams = pAggSym.GetTypeVarsAll();
TypeArray pSourceArgs = pSource.GetTypeArgsAll();
TypeArray pDestArgs = pDest.GetTypeArgsAll();
Debug.Assert(pTypeParams.size == pSourceArgs.size);
Debug.Assert(pTypeParams.size == pDestArgs.size);
for (int iParam = 0; iParam < pTypeParams.size; ++iParam)
{
CType pSourceArg = pSourceArgs.Item(iParam);
CType pDestArg = pDestArgs.Item(iParam);
// If they're identical then this one is automatically good, so skip it.
if (pSourceArg == pDestArg)
{
continue;
}
TypeParameterType pParam = pTypeParams.Item(iParam).AsTypeParameterType();
if (pParam.Invariant)
{
return(false);
}
if (pParam.Covariant)
{
if (!HasImplicitReferenceConversion(pSourceArg, pDestArg))
{
return(false);
}
}
if (pParam.Contravariant)
{
if (!HasImplicitReferenceConversion(pDestArg, pSourceArg))
{
return(false);
}
}
}
return(true);
}
// TypeParameter
public TypeParameterType CreateTypeParameter(TypeParameterSymbol pSymbol)
{
TypeParameterType type = new TypeParameterType();
type.SetTypeParameterSymbol(pSymbol);
type.SetName(pSymbol.name);
Debug.Assert(pSymbol.GetTypeParameterType() == null);
pSymbol.SetTypeParameterType(type);
type.SetTypeKind(TypeKind.TK_TypeParameterType);
return(type);
}
private static IEnumerable <AggregateType> AllPossibleInterfaces(TypeParameterType type)
{
foreach (AggregateType t in type.GetEffectiveBaseClass().TypeAndBaseClassInterfaces())
{
yield return(t);
}
foreach (AggregateType t in type.GetInterfaceBounds().AllConstraintInterfaces())
{
yield return(t);
}
}
private static Type CalculateAssociatedSystemType(CType src)
{
Type result = null;
switch (src.GetTypeKind())
{
case TypeKind.TK_ArrayType:
ArrayType a = (ArrayType)src;
Type elementType = a.GetElementType().AssociatedSystemType;
result = a.IsSZArray ? elementType.MakeArrayType() : elementType.MakeArrayType(a.rank);
break;
case TypeKind.TK_NullableType:
NullableType n = (NullableType)src;
Type underlyingType = n.GetUnderlyingType().AssociatedSystemType;
result = typeof(Nullable <>).MakeGenericType(underlyingType);
break;
case TypeKind.TK_PointerType:
PointerType p = (PointerType)src;
Type referentType = p.GetReferentType().AssociatedSystemType;
result = referentType.MakePointerType();
break;
case TypeKind.TK_ParameterModifierType:
ParameterModifierType r = (ParameterModifierType)src;
Type parameterType = r.GetParameterType().AssociatedSystemType;
result = parameterType.MakeByRefType();
break;
case TypeKind.TK_AggregateType:
result = CalculateAssociatedSystemTypeForAggregate((AggregateType)src);
break;
case TypeKind.TK_TypeParameterType:
TypeParameterType t = (TypeParameterType)src;
if (t.IsMethodTypeParameter())
{
MethodInfo meth = ((MethodSymbol)t.GetOwningSymbol()).AssociatedMemberInfo as MethodInfo;
result = meth.GetGenericArguments()[t.GetIndexInOwnParameters()];
}
else
{
Type parentType = ((AggregateSymbol)t.GetOwningSymbol()).AssociatedSystemType;
result = parentType.GetGenericArguments()[t.GetIndexInOwnParameters()];
}
break;
}
Debug.Assert(result != null || src.GetTypeKind() == TypeKind.TK_AggregateType);
return(result);
}
// TypeParameter
public TypeParameterType CreateTypeParameter(TypeParameterSymbol pSymbol)
{
TypeParameterType type = new TypeParameterType();
type.SetTypeParameterSymbol(pSymbol);
type.SetUnresolved(pSymbol.parent != null && pSymbol.parent.IsAggregateSymbol() && pSymbol.parent.AsAggregateSymbol().IsUnresolved());
type.SetName(pSymbol.name);
Debug.Assert(pSymbol.GetTypeParameterType() == null);
pSymbol.SetTypeParameterType(type);
type.SetTypeKind(TypeKind.TK_TypeParameterType);
return(type);
}
/***************************************************************************************************
*
* There exists an explicit conversion ...
* From a generic delegate type S to generic delegate type T, provided all of the follow are true:
* o Both types are constructed generic types of the same generic delegate type, D<X1,... Xk>.That is,
* S is D<S1,... Sk> and T is D<T1,... Tk>.
* o S is not compatible with or identical to T.
* o If type parameter Xi is declared to be invariant then Si must be identical to Ti.
* o If type parameter Xi is declared to be covariant ("out") then Si must be convertible
* to Ti via an identify conversion, implicit reference conversion, or explicit reference conversion.
* o If type parameter Xi is declared to be contravariant ("in") then either Si must be identical to Ti,
* or Si and Ti must both be reference types.
***************************************************************************************************/
public static bool HasGenericDelegateExplicitReferenceConversion(SymbolLoader loader, CType pSource, CType pTarget)
{
if (!pSource.isDelegateType() ||
!pTarget.isDelegateType() ||
pSource.getAggregate() != pTarget.getAggregate() ||
loader.HasIdentityOrImplicitReferenceConversion(pSource, pTarget))
{
return(false);
}
TypeArray pTypeParams = pSource.getAggregate().GetTypeVarsAll();
TypeArray pSourceArgs = pSource.AsAggregateType().GetTypeArgsAll();
TypeArray pTargetArgs = pTarget.AsAggregateType().GetTypeArgsAll();
Debug.Assert(pTypeParams.size == pSourceArgs.size);
Debug.Assert(pTypeParams.size == pTargetArgs.size);
for (int iParam = 0; iParam < pTypeParams.size; ++iParam)
{
CType pSourceArg = pSourceArgs.Item(iParam);
CType pTargetArg = pTargetArgs.Item(iParam);
// If they're identical then this one is automatically good, so skip it.
// If we have an error type, then we're in some fault tolerance. Let it through.
if (pSourceArg == pTargetArg || pTargetArg.IsErrorType() || pSourceArg.IsErrorType())
{
continue;
}
TypeParameterType pParam = pTypeParams.Item(iParam).AsTypeParameterType();
if (pParam.Invariant)
{
return(false);
}
if (pParam.Covariant)
{
if (!FExpRefConv(loader, pSourceArg, pTargetArg))
{
return(false);
}
}
else if (pParam.Contravariant)
{
if (!pSourceArg.IsRefType() || !pTargetArg.IsRefType())
{
return(false);
}
}
}
return(true);
}
public static bool ParametersContainTyVar(TypeArray @params, TypeParameterType typeFind)
{
Debug.Assert(@params != null);
Debug.Assert(typeFind != null);
for (int p = 0; p < @params.Count; p++)
{
CType sym = @params[p];
if (TypeContainsType(sym, typeFind))
{
return(true);
}
}
return(false);
}
public TypeParameterType GetTypeParameter(TypeParameterSymbol pSymbol)
{
// These guys should be singletons for each.
TypeParameterType pTypeParameter = _typeTable.LookupTypeParameter(pSymbol);
if (pTypeParameter == null)
{
pTypeParameter = _typeFactory.CreateTypeParameter(pSymbol);
_typeTable.InsertTypeParameter(pSymbol, pTypeParameter);
}
return(pTypeParameter);
}
private bool HasImplicitReferenceTypeParameterConversion(
TypeParameterType pSource, CType pDest)
{
Debug.Assert(pSource != null);
Debug.Assert(pDest != null);
if (!pSource.IsRefType())
{
// Not a reference conversion.
return(false);
}
// The following implicit conversions exist for a given type parameter T:
//
// * From T to its effective base class C.
AggregateType pEBC = pSource.GetEffectiveBaseClass();
if (pDest == pEBC)
{
return(true);
}
// * From T to any base class of C.
if (IsBaseClass(pEBC, pDest))
{
return(true);
}
// * From T to any interface implemented by C.
if (IsBaseInterface(pEBC, pDest))
{
return(true);
}
// * From T to any interface type I in T's effective interface set, and
// from T to any base interface of I.
TypeArray pInterfaces = pSource.GetInterfaceBounds();
for (int i = 0; i < pInterfaces.Count; ++i)
{
if (pInterfaces[i] == pDest)
{
return(true);
}
}
// * From T to a type parameter U, provided T depends on U.
if (pDest.IsTypeParameterType() && pSource.DependsOn(pDest.AsTypeParameterType()))
{
return(true);
}
return(false);
}
private bool HasImplicitBoxingTypeParameterConversion(
TypeParameterType pSource, CType pDest)
{
Debug.Assert(pSource != null);
Debug.Assert(pDest != null);
if (pSource.IsRefType())
{
// Not a boxing conversion; both source and destination are references.
return(false);
}
// The following implicit conversions exist for a given type parameter T:
//
// * From T to its effective base class C.
AggregateType pEBC = pSource.GetEffectiveBaseClass();
if (pDest == pEBC)
{
return(true);
}
// * From T to any base class of C.
if (IsBaseClass(pEBC, pDest))
{
return(true);
}
// * From T to any interface implemented by C.
if (IsBaseInterface(pEBC, pDest))
{
return(true);
}
// * From T to any interface type I in T's effective interface set, and
// from T to any base interface of I.
TypeArray pInterfaces = pSource.GetInterfaceBounds();
for (int i = 0; i < pInterfaces.Count; ++i)
{
if (pInterfaces[i] == pDest)
{
return(true);
}
}
// * The conversion from T to a type parameter U, provided T depends on U, is not
// classified as a boxing conversion because it is not guaranteed to box.
// (If both T and U are value types then it is an identity conversion.)
return(false);
}
private bool HasImplicitTypeParameterBaseConversion(
TypeParameterType pSource, CType pDest)
{
Debug.Assert(pSource != null);
Debug.Assert(pDest != null);
if (HasImplicitReferenceTypeParameterConversion(pSource, pDest))
{
return(true);
}
if (HasImplicitBoxingTypeParameterConversion(pSource, pDest))
{
return(true);
}
return(pDest is TypeParameterType typeParamDest && pSource.DependsOn(typeParamDest));
}
////////////////////////////////////////////////////////////////////////////////
// Check whether typeArgs satisfies the constraints of typeVars. The
// typeArgsCls and typeArgsMeth are used for substitution on the bounds. The
// tree and symErr are used for error reporting.
private static bool CheckConstraintsCore(CSemanticChecker checker, ErrorHandling errHandling, Symbol symErr, TypeArray typeVars, TypeArray typeArgs, TypeArray typeArgsCls, TypeArray typeArgsMeth, CheckConstraintsFlags flags)
{
Debug.Assert(typeVars.Count == typeArgs.Count);
Debug.Assert(typeVars.Count > 0);
Debug.Assert(flags == CheckConstraintsFlags.None || flags == CheckConstraintsFlags.NoErrors);
bool fError = false;
for (int i = 0; i < typeVars.Count; i++)
{
// Empty bounds should be set to object.
TypeParameterType var = (TypeParameterType)typeVars[i];
CType arg = typeArgs[i];
bool fOK = CheckSingleConstraint(checker, errHandling, symErr, var, arg, typeArgsCls, typeArgsMeth, flags);
fError |= !fOK;
}
return(!fError);
}
////////////////////////////////////////////////////////////////////////////////
// Check whether typeArgs satisfies the constraints of typeVars. The
// typeArgsCls and typeArgsMeth are used for substitution on the bounds. The
// tree and symErr are used for error reporting.
private static bool CheckConstraintsCore(Symbol symErr, TypeArray typeVars, TypeArray typeArgs, TypeArray typeArgsCls, TypeArray typeArgsMeth, CheckConstraintsFlags flags)
{
Debug.Assert(typeVars.Count == typeArgs.Count);
Debug.Assert(typeVars.Count > 0);
Debug.Assert(flags == CheckConstraintsFlags.None || flags == CheckConstraintsFlags.NoErrors);
for (int i = 0; i < typeVars.Count; i++)
{
// Empty bounds should be set to object.
TypeParameterType var = (TypeParameterType)typeVars[i];
CType arg = typeArgs[i];
if (!CheckSingleConstraint(symErr, var, arg, typeArgsCls, typeArgsMeth, flags))
{
return(false);
}
}
return(true);
}
// TypeParameter
public TypeParameterType CreateTypeParameter(TypeParameterSymbol pSymbol)
{
TypeParameterType type = new TypeParameterType();
type.SetTypeParameterSymbol(pSymbol);
type.SetUnresolved(pSymbol.parent != null && pSymbol.parent.IsAggregateSymbol() && pSymbol.parent.AsAggregateSymbol().IsUnresolved());
type.SetName(pSymbol.name);
#if CSEE
type.typeRes = type;
if (!type.IsUnresolved())
{
type.tsRes = ktsImportMax;
}
#endif // CSEE
Debug.Assert(pSymbol.GetTypeParameterType() == null);
pSymbol.SetTypeParameterType(type);
type.SetTypeKind(TypeKind.TK_TypeParameterType);
return type;
}
// TypeParameter
public TypeParameterType CreateTypeParameter(TypeParameterSymbol pSymbol)
{
TypeParameterType type = new TypeParameterType();
type.SetTypeParameterSymbol(pSymbol);
type.SetUnresolved(pSymbol.parent != null && pSymbol.parent.IsAggregateSymbol() && pSymbol.parent.AsAggregateSymbol().IsUnresolved());
type.SetName(pSymbol.name);
#if CSEE
type.typeRes = type;
if (!type.IsUnresolved())
{
type.tsRes = ktsImportMax;
}
#endif // CSEE
Debug.Assert(pSymbol.GetTypeParameterType() == null);
pSymbol.SetTypeParameterType(type);
type.SetTypeKind(TypeKind.TK_TypeParameterType);
return(type);
}
////////////////////////////////////////////////////////////////////////////////
// Get the standard type variable (eg, !0, !1, or !!0, !!1).
//
// iv is the index.
// pbsm is the containing symbol manager
// fMeth designates whether this is a method type var or class type var
//
// The standard class type variables are useful during emit, but not for type
// comparison when binding. The standard method type variables are useful during
// binding for signature comparison.
public TypeParameterType GetTypeVarSym(int iv, TypeManager pTypeManager, bool fMeth)
{
Debug.Assert(iv >= 0);
TypeParameterType tpt = null;
if (iv >= this.prgptvs.Count)
{
TypeParameterSymbol pTypeParameter = new TypeParameterSymbol();
pTypeParameter.SetIsMethodTypeParameter(fMeth);
pTypeParameter.SetIndexInOwnParameters(iv);
pTypeParameter.SetIndexInTotalParameters(iv);
pTypeParameter.SetAccess(ACCESS.ACC_PRIVATE);
tpt = pTypeManager.GetTypeParameter(pTypeParameter);
this.prgptvs.Add(tpt);
}
else
{
tpt = this.prgptvs[iv];
}
Debug.Assert(tpt != null);
return(tpt);
}
private static Type CalculateAssociatedSystemType(CType src)
{
Type result = null;
switch (src.GetTypeKind())
{
case TypeKind.TK_ArrayType:
ArrayType a = src.AsArrayType();
Type elementType = a.GetElementType().AssociatedSystemType;
if (a.rank == 1)
{
result = elementType.MakeArrayType();
}
else
{
result = elementType.MakeArrayType(a.rank);
}
break;
case TypeKind.TK_NullableType:
NullableType n = src.AsNullableType();
Type underlyingType = n.GetUnderlyingType().AssociatedSystemType;
result = typeof(Nullable <>).MakeGenericType(underlyingType);
break;
case TypeKind.TK_PointerType:
PointerType p = src.AsPointerType();
Type referentType = p.GetReferentType().AssociatedSystemType;
result = referentType.MakePointerType();
break;
case TypeKind.TK_ParameterModifierType:
ParameterModifierType r = src.AsParameterModifierType();
Type parameterType = r.GetParameterType().AssociatedSystemType;
result = parameterType.MakeByRefType();
break;
case TypeKind.TK_AggregateType:
result = CalculateAssociatedSystemTypeForAggregate(src.AsAggregateType());
break;
case TypeKind.TK_TypeParameterType:
TypeParameterType t = src.AsTypeParameterType();
Type parentType = null;
if (t.IsMethodTypeParameter())
{
MethodInfo meth = t.GetOwningSymbol().AsMethodSymbol().AssociatedMemberInfo as MethodInfo;
result = meth.GetGenericArguments()[t.GetIndexInOwnParameters()];
}
else
{
parentType = t.GetOwningSymbol().AsAggregateSymbol().AssociatedSystemType;
result = parentType.GetTypeInfo().GenericTypeParameters[t.GetIndexInOwnParameters()];
}
break;
case TypeKind.TK_ArgumentListType:
case TypeKind.TK_BoundLambdaType:
case TypeKind.TK_ErrorType:
case TypeKind.TK_MethodGroupType:
case TypeKind.TK_NaturalIntegerType:
case TypeKind.TK_NullType:
case TypeKind.TK_OpenTypePlaceholderType:
case TypeKind.TK_UnboundLambdaType:
case TypeKind.TK_VoidType:
default:
break;
}
Debug.Assert(result != null || src.GetTypeKind() == TypeKind.TK_AggregateType);
return(result);
}
public void InsertTypeParameter(
TypeParameterSymbol pTypeParameterSymbol,
TypeParameterType pTypeParameter)
{
_pTypeParameterTable.Add(pTypeParameterSymbol, pTypeParameter);
}
public TypeArray GetStdMethTyVarArray(int cTyVars)
{
TypeParameterType[] prgvar = new TypeParameterType[cTyVars];
for (int ivar = 0; ivar < cTyVars; ivar++)
{
prgvar[ivar] = GetStdMethTypeVar(ivar);
}
return _BSymmgr.AllocParams(cTyVars, (CType[])prgvar);
}
////////////////////////////////////////////////////////////////////////////////
//
// Output types
//
private bool DoesOutputTypeContain(EXPR pSource, CType pDest,
TypeParameterType pParam)
{
// SPEC: If E is a method group or an anonymous function and T is a delegate
// SPEC: CType or expression tree CType then the return CType of T is an output CType
// SPEC: of E with CType T.
pDest = pDest.GetDelegateTypeOfPossibleExpression();
if (!pDest.isDelegateType())
{
return false;
}
if (!pSource.isUNBOUNDLAMBDA() && !pSource.isMEMGRP())
{
return false;
}
CType pDelegateReturn = pDest.AsAggregateType().GetDelegateReturnType(GetSymbolLoader());
if (pDelegateReturn == null)
{
return false;
}
return TypeManager.TypeContainsType(pDelegateReturn, pParam);
}
////////////////////////////////////////////////////////////////////////////////
private void AddExactBound(TypeParameterType pParam, CType pBound)
{
Debug.Assert(IsUnfixed(pParam));
int iParam = pParam.GetIndexInTotalParameters();
if (!_pExactBounds[iParam].Contains(pBound))
{
_pExactBounds[iParam].Add(pBound);
}
}
private static bool CheckSingleConstraint(Symbol symErr, TypeParameterType var, CType arg, TypeArray typeArgsCls, TypeArray typeArgsMeth, CheckConstraintsFlags flags)
{
Debug.Assert(!(arg is PointerType));
Debug.Assert(!arg.IsStaticClass);
bool fReportErrors = 0 == (flags & CheckConstraintsFlags.NoErrors);
if (var.HasRefConstraint && !arg.IsReferenceType)
{
if (fReportErrors)
{
throw ErrorHandling.Error(ErrorCode.ERR_RefConstraintNotSatisfied, symErr, new ErrArgNoRef(var), arg);
}
return(false);
}
TypeArray bnds = TypeManager.SubstTypeArray(var.Bounds, 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.
if (!arg.IsNonNullableValueType)
{
if (fReportErrors)
{
throw ErrorHandling.Error(ErrorCode.ERR_ValConstraintNotSatisfied, symErr, new ErrArgNoRef(var), arg);
}
return(false);
}
// 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(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.IsReferenceType)
{
// A reference type can only satisfy bounds to types
// to which they have an implicit reference conversion
error = ErrorCode.ERR_GenericConstraintNotSatisfiedRefType;
}
else if (arg is NullableType nubArg && SymbolLoader.HasBaseConversion(nubArg.UnderlyingType, 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) || nubArg.UnderlyingType == 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
{
// 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;
}
throw ErrorHandling.Error(error, new ErrArg(symErr), new ErrArg(typeBnd, ErrArgFlags.Unique), var, new ErrArg(arg, ErrArgFlags.Unique));
}
return(false);
}
}
private bool HasImplicitTypeParameterBaseConversion(
TypeParameterType pSource, CType pDest)
{
Debug.Assert(pSource != null);
Debug.Assert(pDest != null);
if (HasImplicitReferenceTypeParameterConversion(pSource, pDest))
{
return true;
}
if (HasImplicitBoxingTypeParameterConversion(pSource, pDest))
{
return true;
}
if (pDest.IsTypeParameterType() && pSource.DependsOn(pDest.AsTypeParameterType()))
{
return true;
}
return false;
}
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);
}
public static bool ParametersContainTyVar(TypeArray @params, TypeParameterType typeFind)
{
Debug.Assert(@params != null);
Debug.Assert(typeFind != null);
for (int p = 0; p < @params.size; p++)
{
CType sym = @params[p];
if (TypeContainsType(sym, typeFind))
{
return true;
}
}
return false;
}
private bool bindImplicitConversionFromTypeVar(TypeParameterType tyVarSrc)
{
// 13.1.4
//
// For a type-parameter T that is known to be a reference type (25.7), the following implicit
// reference conversions exist:
//
// * From T to its effective base class C, from T to any base class of C, and from T to any
// interface implemented by C.
// * From T to an interface-type I in T's effective interface set and from T to any base
// interface of I.
// * From T to a type parameter U provided that T depends on U (25.7). [Note: Since T is known
// to be a reference type, within the scope of T, the run-time type of U will always be a
// reference type, even if U is not known to be a reference type at compile-time.]
// * From the null type (11.2.7) to T.
//
// 13.1.5
//
// For a type-parameter T that is not known to be a reference type (25.7), the following conversions
// involving T are considered to be boxing conversions at compile-time. At run-time, if T is a value
// type, the conversion is executed as a boxing conversion. At run-time, if T is a reference type,
// the conversion is executed as an implicit reference conversion or identity conversion.
//
// * From T to its effective base class C, from T to any base class of C, and from T to any
// interface implemented by C. [Note: C will be one of the types System.Object, System.ValueType,
// or System.Enum (otherwise T would be known to be a reference type and 13.1.4 would apply
// instead of this clause).]
// * From T to an interface-type I in T's effective interface set and from T to any base
// interface of I.
//
// 13.1.6 Implicit type parameter conversions
//
// This clause details implicit conversions involving type parameters that are not classified as
// implicit reference conversions or implicit boxing conversions.
//
// For a type-parameter T that is not known to be a reference type, there is an implicit conversion
// from T to a type parameter U provided T depends on U. At run-time, if T is a value type and U is
// a reference type, the conversion is executed as a boxing conversion. At run-time, if both T and U
// are value types, then T and U are necessarily the same type and no conversion is performed. At
// run-time, if T is a reference type, then U is necessarily also a reference type and the conversion
// is executed as an implicit reference conversion or identity conversion (25.7).
CType typeTmp = tyVarSrc.GetEffectiveBaseClass();
TypeArray bnds = tyVarSrc.GetBounds();
int itype = -1;
for (; ;)
{
if (binder.canConvert(typeTmp, typeDest, flags | CONVERTTYPE.NOUDC))
{
if (!needsExprDest)
{
return(true);
}
if (typeDest.IsTypeParameterType())
{
// For a type var destination we need to cast to object then to the other type var.
EXPR exprT;
EXPRCLASS exprObj = GetExprFactory().MakeClass(binder.GetReqPDT(PredefinedType.PT_OBJECT));
binder.bindSimpleCast(exprSrc, exprObj, out exprT, EXPRFLAG.EXF_FORCE_BOX);
binder.bindSimpleCast(exprT, exprTypeDest, out exprDest, EXPRFLAG.EXF_FORCE_UNBOX);
}
else
{
binder.bindSimpleCast(exprSrc, exprTypeDest, out exprDest, EXPRFLAG.EXF_FORCE_BOX);
}
return(true);
}
do
{
if (++itype >= bnds.Size)
{
return(false);
}
typeTmp = bnds.Item(itype);
}while (!typeTmp.isInterfaceType() && !typeTmp.IsTypeParameterType());
}
}
public void SetTypeParameterType(TypeParameterType pType)
{
_pTypeParameterType = pType;
}
public void SetTypeParameterType(TypeParameterType pType)
{
_pTypeParameterType = pType;
}
////////////////////////////////////////////////////////////////////////////////
private bool IsUnfixed(TypeParameterType pParam)
{
Debug.Assert(pParam != null);
Debug.Assert(pParam.IsMethodTypeParameter());
int iParam = pParam.GetIndexInTotalParameters();
Debug.Assert(_pMethodTypeParameters.ItemAsTypeParameterType(iParam) == pParam);
return IsUnfixed(iParam);
}
private bool HasImplicitReferenceTypeParameterConversion(
TypeParameterType pSource, CType pDest)
{
Debug.Assert(pSource != null);
Debug.Assert(pDest != null);
if (!pSource.IsRefType())
{
// Not a reference conversion.
return false;
}
// The following implicit conversions exist for a given type parameter T:
//
// * From T to its effective base class C.
AggregateType pEBC = pSource.GetEffectiveBaseClass();
if (pDest == pEBC)
{
return true;
}
// * From T to any base class of C.
if (IsBaseClass(pEBC, pDest))
{
return true;
}
// * From T to any interface implemented by C.
if (IsBaseInterface(pEBC, pDest))
{
return true;
}
// * From T to any interface type I in T's effective interface set, and
// from T to any base interface of I.
TypeArray pInterfaces = pSource.GetInterfaceBounds();
for (int i = 0; i < pInterfaces.Size; ++i)
{
if (pInterfaces.Item(i) == pDest)
{
return true;
}
}
// * From T to a type parameter U, provided T depends on U.
if (pDest.IsTypeParameterType() && pSource.DependsOn(pDest.AsTypeParameterType()))
{
return true;
}
return false;
}
////////////////////////////////////////////////////////////////////////////////
//
// Input types
//
private bool DoesInputTypeContain(EXPR pSource, CType pDest,
TypeParameterType pParam)
{
// SPEC: If E is a method group or an anonymous function and T is a delegate
// SPEC: CType or expression tree CType then all the parameter types of T are
// SPEC: input types of E with CType T.
pDest = pDest.GetDelegateTypeOfPossibleExpression();
if (!pDest.isDelegateType())
{
return false; // No input types.
}
if (!pSource.isUNBOUNDLAMBDA() && !pSource.isMEMGRP())
{
return false; // No input types.
}
TypeArray pDelegateParameters =
pDest.AsAggregateType().GetDelegateParameters(GetSymbolLoader());
if (pDelegateParameters == null)
{
return false;
}
return TypeManager.ParametersContainTyVar(pDelegateParameters, pParam);
}
private bool bindImplicitConversionFromTypeVar(TypeParameterType tyVarSrc)
{
// 13.1.4
//
// For a type-parameter T that is known to be a reference type (25.7), the following implicit
// reference conversions exist:
//
// * From T to its effective base class C, from T to any base class of C, and from T to any
// interface implemented by C.
// * From T to an interface-type I in T's effective interface set and from T to any base
// interface of I.
// * From T to a type parameter U provided that T depends on U (25.7). [Note: Since T is known
// to be a reference type, within the scope of T, the run-time type of U will always be a
// reference type, even if U is not known to be a reference type at compile-time.]
// * From the null type (11.2.7) to T.
//
// 13.1.5
//
// For a type-parameter T that is not known to be a reference type (25.7), the following conversions
// involving T are considered to be boxing conversions at compile-time. At run-time, if T is a value
// type, the conversion is executed as a boxing conversion. At run-time, if T is a reference type,
// the conversion is executed as an implicit reference conversion or identity conversion.
//
// * From T to its effective base class C, from T to any base class of C, and from T to any
// interface implemented by C. [Note: C will be one of the types System.Object, System.ValueType,
// or System.Enum (otherwise T would be known to be a reference type and 13.1.4 would apply
// instead of this clause).]
// * From T to an interface-type I in T's effective interface set and from T to any base
// interface of I.
//
// 13.1.6 Implicit type parameter conversions
//
// This clause details implicit conversions involving type parameters that are not classified as
// implicit reference conversions or implicit boxing conversions.
//
// For a type-parameter T that is not known to be a reference type, there is an implicit conversion
// from T to a type parameter U provided T depends on U. At run-time, if T is a value type and U is
// a reference type, the conversion is executed as a boxing conversion. At run-time, if both T and U
// are value types, then T and U are necessarily the same type and no conversion is performed. At
// run-time, if T is a reference type, then U is necessarily also a reference type and the conversion
// is executed as an implicit reference conversion or identity conversion (25.7).
CType typeTmp = tyVarSrc.GetEffectiveBaseClass();
TypeArray bnds = tyVarSrc.GetBounds();
int itype = -1;
for (; ;)
{
if (_binder.canConvert(typeTmp, _typeDest, _flags | CONVERTTYPE.NOUDC))
{
if (!_needsExprDest)
{
return true;
}
if (_typeDest.IsTypeParameterType())
{
// For a type var destination we need to cast to object then to the other type var.
EXPR exprT;
EXPRCLASS exprObj = GetExprFactory().MakeClass(_binder.GetReqPDT(PredefinedType.PT_OBJECT));
_binder.bindSimpleCast(_exprSrc, exprObj, out exprT, EXPRFLAG.EXF_FORCE_BOX);
_binder.bindSimpleCast(exprT, _exprTypeDest, out _exprDest, EXPRFLAG.EXF_FORCE_UNBOX);
}
else
{
_binder.bindSimpleCast(_exprSrc, _exprTypeDest, out _exprDest, EXPRFLAG.EXF_FORCE_BOX);
}
return true;
}
do
{
if (++itype >= bnds.Size)
{
return false;
}
typeTmp = bnds.Item(itype);
}
while (!typeTmp.isInterfaceType() && !typeTmp.IsTypeParameterType());
}
}
private bool HasImplicitBoxingTypeParameterConversion(
TypeParameterType pSource, CType pDest)
{
Debug.Assert(pSource != null);
Debug.Assert(pDest != null);
if (pSource.IsRefType())
{
// Not a boxing conversion; both source and destination are references.
return false;
}
// The following implicit conversions exist for a given type parameter T:
//
// * From T to its effective base class C.
AggregateType pEBC = pSource.GetEffectiveBaseClass();
if (pDest == pEBC)
{
return true;
}
// * From T to any base class of C.
if (IsBaseClass(pEBC, pDest))
{
return true;
}
// * From T to any interface implemented by C.
if (IsBaseInterface(pEBC, pDest))
{
return true;
}
// * From T to any interface type I in T's effective interface set, and
// from T to any base interface of I.
TypeArray pInterfaces = pSource.GetInterfaceBounds();
for (int i = 0; i < pInterfaces.Size; ++i)
{
if (pInterfaces.Item(i) == pDest)
{
return true;
}
}
// * The conversion from T to a type parameter U, provided T depends on U, is not
// classified as a boxing conversion because it is not guaranteed to box.
// (If both T and U are value types then it is an identity conversion.)
return false;
}
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;
}