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;
}
//////////////////////////////////////////////////////////////////////////////
private 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.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 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);
// Substitute on the CType.
if (atsCheck.GetTypeArgsAll().Count > 0)
{
CType = SymbolLoader.GetTypeManager().SubstType(CType, atsCheck);
}
return(CheckTypeAccess(CType, symWhere) ? ACCESSERROR.ACCESSERROR_NOERROR : ACCESSERROR.ACCESSERROR_NOACCESS);
}
private AggregateType SubstTypeCore(AggregateType type, SubstContext ctx)
{
TypeArray args = type.GetTypeArgsAll();
if (args.Count > 0)
{
TypeArray typeArgs = SubstTypeArray(args, ctx);
if (args != typeArgs)
{
return(GetAggregate(type.getAggregate(), typeArgs));
}
}
return(type);
}
public AggregateType GetBaseClass()
{
#if CSEE
AggregateType atsBase = getAggregate().GetBaseClass();
if (!atsBase || GetTypeArgsAll().size == 0 || atsBase.GetTypeArgsAll().size == 0)
return atsBase;
return getAggregate().GetTypeManager().SubstType(atsBase, GetTypeArgsAll()).AsAggregateType();
#else // !CSEE
if (_baseType == null)
{
_baseType = getAggregate().GetTypeManager().SubstType(getAggregate().GetBaseClass(), GetTypeArgsAll()) as AggregateType;
}
return _baseType;
#endif // !CSEE
}
public AggregateType GetAggregate(AggregateSymbol agg, AggregateType atsOuter, TypeArray typeArgs)
{
Debug.Assert(agg.GetTypeManager() == this);
Debug.Assert(atsOuter == null || atsOuter.getAggregate() == agg.Parent, "");
if (typeArgs == null)
{
typeArgs = BSYMMGR.EmptyTypeArray();
}
Debug.Assert(agg.GetTypeVars().Count == typeArgs.Count);
AggregateType pAggregate = _typeTable.LookupAggregate(agg, atsOuter, typeArgs);
if (pAggregate == null)
{
pAggregate = _typeFactory.CreateAggregateType(
agg,
typeArgs,
atsOuter
);
Debug.Assert(!pAggregate.fConstraintsChecked && !pAggregate.fConstraintError);
pAggregate.SetErrors(false);
_typeTable.InsertAggregate(agg, atsOuter, typeArgs, pAggregate);
}
else
{
Debug.Assert(!pAggregate.HasErrors());
}
Debug.Assert(pAggregate.getAggregate() == agg);
Debug.Assert(pAggregate.GetTypeArgsThis() != null && pAggregate.GetTypeArgsAll() != null);
Debug.Assert(pAggregate.GetTypeArgsThis() == typeArgs);
return(pAggregate);
}
private CType SubstTypeCore(CType type, SubstContext pctx)
{
CType typeSrc;
CType typeDst;
switch (type.GetTypeKind())
{
default:
Debug.Assert(false);
return(type);
case TypeKind.TK_NullType:
case TypeKind.TK_VoidType:
case TypeKind.TK_MethodGroupType:
case TypeKind.TK_ArgumentListType:
return(type);
case TypeKind.TK_ParameterModifierType:
ParameterModifierType mod = (ParameterModifierType)type;
typeDst = SubstTypeCore(typeSrc = mod.GetParameterType(), pctx);
return((typeDst == typeSrc) ? type : GetParameterModifier(typeDst, mod.isOut));
case TypeKind.TK_ArrayType:
var arr = (ArrayType)type;
typeDst = SubstTypeCore(typeSrc = arr.GetElementType(), pctx);
return((typeDst == typeSrc) ? type : GetArray(typeDst, arr.rank, arr.IsSZArray));
case TypeKind.TK_PointerType:
typeDst = SubstTypeCore(typeSrc = ((PointerType)type).GetReferentType(), pctx);
return((typeDst == typeSrc) ? type : GetPointer(typeDst));
case TypeKind.TK_NullableType:
typeDst = SubstTypeCore(typeSrc = ((NullableType)type).GetUnderlyingType(), pctx);
return((typeDst == typeSrc) ? type : GetNullable(typeDst));
case TypeKind.TK_AggregateType:
AggregateType ats = (AggregateType)type;
if (ats.GetTypeArgsAll().Count > 0)
{
TypeArray typeArgs = SubstTypeArray(ats.GetTypeArgsAll(), pctx);
if (ats.GetTypeArgsAll() != typeArgs)
{
return(GetAggregate(ats.getAggregate(), typeArgs));
}
}
return(type);
case TypeKind.TK_ErrorType:
ErrorType err = (ErrorType)type;
if (err.HasParent)
{
Debug.Assert(err.nameText != null && err.typeArgs != null);
TypeArray typeArgs = SubstTypeArray(err.typeArgs, pctx);
if (typeArgs != err.typeArgs)
{
return(GetErrorType(err.nameText, typeArgs));
}
}
return(type);
case TypeKind.TK_TypeParameterType:
{
TypeParameterSymbol tvs = ((TypeParameterType)type).GetTypeParameterSymbol();
int index = tvs.GetIndexInTotalParameters();
if (tvs.IsMethodTypeParameter())
{
if ((pctx.grfst & SubstTypeFlags.DenormMeth) != 0 && tvs.parent != null)
{
return(type);
}
Debug.Assert(tvs.GetIndexInOwnParameters() == tvs.GetIndexInTotalParameters());
if (index < pctx.ctypeMeth)
{
Debug.Assert(pctx.prgtypeMeth != null);
return(pctx.prgtypeMeth[index]);
}
else
{
return((pctx.grfst & SubstTypeFlags.NormMeth) != 0 ? GetStdMethTypeVar(index) : type);
}
}
if ((pctx.grfst & SubstTypeFlags.DenormClass) != 0 && tvs.parent != null)
{
return(type);
}
return(index < pctx.ctypeCls ? pctx.prgtypeCls[index] :
((pctx.grfst & SubstTypeFlags.NormClass) != 0 ? GetStdClsTypeVar(index) : type));
}
}
}
////////////////////////////////////////////////////////////////////////////////
private void ExactTypeArgumentInference(
AggregateType pSource, AggregateType pDest)
{
Debug.Assert(pSource != null);
Debug.Assert(pDest != null);
Debug.Assert(pSource.GetOwningAggregate() == pDest.GetOwningAggregate());
TypeArray pSourceArgs = pSource.GetTypeArgsAll();
TypeArray pDestArgs = pDest.GetTypeArgsAll();
Debug.Assert(pSourceArgs != null);
Debug.Assert(pDestArgs != null);
Debug.Assert(pSourceArgs.size == pDestArgs.size);
for (int arg = 0; arg < pSourceArgs.size; ++arg)
{
ExactInference(pSourceArgs.Item(arg), pDestArgs.Item(arg));
}
}
private static Type CalculateAssociatedSystemTypeForAggregate(AggregateType aggtype)
{
AggregateSymbol agg = aggtype.GetOwningAggregate();
TypeArray typeArgs = aggtype.GetTypeArgsAll();
List<Type> list = new List<Type>();
// Get each type arg.
for (int i = 0; i < typeArgs.size; i++)
{
// Unnamed type parameter types are just placeholders.
if (typeArgs.Item(i).IsTypeParameterType() && typeArgs.Item(i).AsTypeParameterType().GetTypeParameterSymbol().name == null)
{
return null;
}
list.Add(typeArgs.Item(i).AssociatedSystemType);
}
Type[] systemTypeArgs = list.ToArray();
Type uninstantiatedType = agg.AssociatedSystemType;
if (uninstantiatedType.GetTypeInfo().IsGenericType)
{
try
{
return uninstantiatedType.MakeGenericType(systemTypeArgs);
}
catch (ArgumentException)
{
// If the constraints don't work, just return the type without substituting it.
return uninstantiatedType;
}
}
return uninstantiatedType;
}
public TypeArray SubstTypeArray(TypeArray taSrc, AggregateType atsCls, TypeArray typeArgsMeth)
{
return(SubstTypeArray(taSrc, atsCls?.GetTypeArgsAll(), typeArgsMeth));
}
public static bool TypeContainsTyVars(CType type, TypeArray typeVars)
{
LRecurse: // Label used for "tail" recursion.
switch (type.GetTypeKind())
{
default:
Debug.Assert(false, "Bad Symbol kind in TypeContainsTyVars");
return(false);
case TypeKind.TK_NullType:
case TypeKind.TK_VoidType:
case TypeKind.TK_MethodGroupType:
return(false);
case TypeKind.TK_ArrayType:
case TypeKind.TK_NullableType:
case TypeKind.TK_ParameterModifierType:
case TypeKind.TK_PointerType:
type = type.GetBaseOrParameterOrElementType();
goto LRecurse;
case TypeKind.TK_AggregateType:
{ // BLOCK
AggregateType ats = (AggregateType)type;
for (int i = 0; i < ats.GetTypeArgsAll().Count; i++)
{
if (TypeContainsTyVars(ats.GetTypeArgsAll()[i], typeVars))
{
return(true);
}
}
}
return(false);
case TypeKind.TK_ErrorType:
ErrorType err = (ErrorType)type;
if (err.HasParent)
{
Debug.Assert(err.nameText != null && err.typeArgs != null);
for (int i = 0; i < err.typeArgs.Count; i++)
{
if (TypeContainsTyVars(err.typeArgs[i], typeVars))
{
return(true);
}
}
}
return(false);
case TypeKind.TK_TypeParameterType:
if (typeVars != null && typeVars.Count > 0)
{
int ivar = ((TypeParameterType)type).GetIndexInTotalParameters();
return(ivar < typeVars.Count && type == typeVars[ivar]);
}
return(true);
}
}
//////////////////////////////////////////////////////////////////////////////
private 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;
}
// 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);
}
private bool IsDelegateType(CType pSrcType, AggregateType pAggType)
{
CType pInstantiatedType = GetSymbolLoader().GetTypeManager().SubstType(pSrcType, pAggType, pAggType.GetTypeArgsAll());
return pInstantiatedType.isDelegateType();
}
public SubstContext(AggregateType type, TypeArray typeArgsMeth, SubstTypeFlags grfst)
{
Init(type != null ? type.GetTypeArgsAll() : null, typeArgsMeth, grfst);
}
private bool SubstEqualTypesCore(CType typeDst, CType typeSrc, SubstContext pctx)
{
LRecurse: // Label used for "tail" recursion.
if (typeDst == typeSrc || typeDst.Equals(typeSrc))
{
return(true);
}
switch (typeSrc.GetTypeKind())
{
default:
Debug.Assert(false, "Bad Symbol kind in SubstEqualTypesCore");
return(false);
case TypeKind.TK_NullType:
case TypeKind.TK_VoidType:
// There should only be a single instance of these.
Debug.Assert(typeDst.GetTypeKind() != typeSrc.GetTypeKind());
return(false);
case TypeKind.TK_ArrayType:
ArrayType arrSrc = (ArrayType)typeSrc;
if (!(typeDst is ArrayType arrDst) || arrDst.rank != arrSrc.rank || arrDst.IsSZArray != arrSrc.IsSZArray)
{
return(false);
}
goto LCheckBases;
case TypeKind.TK_ParameterModifierType:
if (!(typeDst is ParameterModifierType modDest) ||
((pctx.grfst & SubstTypeFlags.NoRefOutDifference) == 0 &&
modDest.isOut != ((ParameterModifierType)typeSrc).isOut))
{
return(false);
}
goto LCheckBases;
case TypeKind.TK_PointerType:
case TypeKind.TK_NullableType:
if (typeDst.GetTypeKind() != typeSrc.GetTypeKind())
{
return(false);
}
LCheckBases:
typeSrc = typeSrc.GetBaseOrParameterOrElementType();
typeDst = typeDst.GetBaseOrParameterOrElementType();
goto LRecurse;
case TypeKind.TK_AggregateType:
if (!(typeDst is AggregateType atsDst))
{
return(false);
}
{ // BLOCK
AggregateType atsSrc = (AggregateType)typeSrc;
if (atsSrc.getAggregate() != atsDst.getAggregate())
{
return(false);
}
Debug.Assert(atsSrc.GetTypeArgsAll().Count == atsDst.GetTypeArgsAll().Count);
// All the args must unify.
for (int i = 0; i < atsSrc.GetTypeArgsAll().Count; i++)
{
if (!SubstEqualTypesCore(atsDst.GetTypeArgsAll()[i], atsSrc.GetTypeArgsAll()[i], pctx))
{
return(false);
}
}
}
return(true);
case TypeKind.TK_ErrorType:
ErrorType errSrc = (ErrorType)typeSrc;
if (!(typeDst is ErrorType errDst) || !errSrc.HasParent || !errDst.HasParent)
{
return(false);
}
{
Debug.Assert(errSrc.nameText != null && errSrc.typeArgs != null);
Debug.Assert(errDst.nameText != null && errDst.typeArgs != null);
if (errSrc.nameText != errDst.nameText || errSrc.typeArgs.Count != errDst.typeArgs.Count ||
errSrc.HasParent != errDst.HasParent)
{
return(false);
}
// All the args must unify.
for (int i = 0; i < errSrc.typeArgs.Count; i++)
{
if (!SubstEqualTypesCore(errDst.typeArgs[i], errSrc.typeArgs[i], pctx))
{
return(false);
}
}
}
return(true);
case TypeKind.TK_TypeParameterType:
{ // BLOCK
TypeParameterSymbol tvs = ((TypeParameterType)typeSrc).GetTypeParameterSymbol();
int index = tvs.GetIndexInTotalParameters();
if (tvs.IsMethodTypeParameter())
{
if ((pctx.grfst & SubstTypeFlags.DenormMeth) != 0 && tvs.parent != null)
{
// typeDst == typeSrc was handled above.
Debug.Assert(typeDst != typeSrc);
return(false);
}
Debug.Assert(tvs.GetIndexInOwnParameters() == tvs.GetIndexInTotalParameters());
Debug.Assert(pctx.prgtypeMeth == null || tvs.GetIndexInTotalParameters() < pctx.ctypeMeth);
if (index < pctx.ctypeMeth && pctx.prgtypeMeth != null)
{
return(typeDst == pctx.prgtypeMeth[index]);
}
if ((pctx.grfst & SubstTypeFlags.NormMeth) != 0)
{
return(typeDst == GetStdMethTypeVar(index));
}
}
else
{
if ((pctx.grfst & SubstTypeFlags.DenormClass) != 0 && tvs.parent != null)
{
// typeDst == typeSrc was handled above.
Debug.Assert(typeDst != typeSrc);
return(false);
}
Debug.Assert(pctx.prgtypeCls == null || tvs.GetIndexInTotalParameters() < pctx.ctypeCls);
if (index < pctx.ctypeCls)
{
return(typeDst == pctx.prgtypeCls[index]);
}
if ((pctx.grfst & SubstTypeFlags.NormClass) != 0)
{
return(typeDst == GetStdClsTypeVar(index));
}
}
}
return(false);
}
}
public static bool TypeContainsType(CType type, CType typeFind)
{
LRecurse: // Label used for "tail" recursion.
if (type == typeFind || type.Equals(typeFind))
{
return(true);
}
switch (type.GetTypeKind())
{
default:
Debug.Assert(false, "Bad Symbol kind in TypeContainsType");
return(false);
case TypeKind.TK_NullType:
case TypeKind.TK_VoidType:
// There should only be a single instance of these.
Debug.Assert(typeFind.GetTypeKind() != type.GetTypeKind());
return(false);
case TypeKind.TK_ArrayType:
case TypeKind.TK_NullableType:
case TypeKind.TK_ParameterModifierType:
case TypeKind.TK_PointerType:
type = type.GetBaseOrParameterOrElementType();
goto LRecurse;
case TypeKind.TK_AggregateType:
{ // BLOCK
AggregateType ats = (AggregateType)type;
for (int i = 0; i < ats.GetTypeArgsAll().Count; i++)
{
if (TypeContainsType(ats.GetTypeArgsAll()[i], typeFind))
{
return(true);
}
}
}
return(false);
case TypeKind.TK_ErrorType:
ErrorType err = (ErrorType)type;
if (err.HasParent)
{
Debug.Assert(err.nameText != null && err.typeArgs != null);
for (int i = 0; i < err.typeArgs.Count; i++)
{
if (TypeContainsType(err.typeArgs[i], typeFind))
{
return(true);
}
}
}
return(false);
case TypeKind.TK_TypeParameterType:
return(false);
}
}
/***************************************************************************************************
* Determine whether there is an explicit or implicit reference conversion (or identity conversion)
* from typeSrc to typeDst. This is when:
*
* 13.2.3 Explicit reference conversions
*
* The explicit reference conversions are:
* From object to any reference-type.
* From any class-type S to any class-type T, provided S is a base class of T.
* From any class-type S to any interface-type T, provided S is not sealed and provided S does not implement T.
* From any interface-type S to any class-type T, provided T is not sealed or provided T implements S.
* From any interface-type S to any interface-type T, provided S is not derived from T.
* From an array-type S with an element type SE to an array-type T with an element type TE, provided all of the following are true:
* o S and T differ only in element type. (In other words, S and T have the same number of dimensions.)
* o An explicit reference conversion exists from SE to TE.
* From System.Array and the interfaces it implements, to any array-type.
* From System.Delegate and the interfaces it implements, to any delegate-type.
* From a one-dimensional array-type S[] to System.Collections.Generic.IList<T>, System.Collections.Generic.IReadOnlyList<T> and their base interfaces, provided there is an explicit reference conversion from S to T.
* 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.
* From System.Collections.Generic.IList<T>, System.Collections.Generic.IReadOnlyList<T> and their base interfaces to a one-dimensional array-type S[], provided there is an implicit or explicit reference conversion from S[] to System.Collections.Generic.IList<T> or System.Collections.Generic.IReadOnlyList<T>. This is precisely when either S and T are the same type or there is an implicit or explicit reference conversion from S to T.
*
* For a type-parameter T that is known to be a reference type (§25.7), the following explicit reference conversions exist:
* From the effective base class C of T to T and from any base class of C to T.
* From any interface-type to T.
* From T to any interface-type I provided there isn’t already an implicit reference conversion from T to I.
* From a type-parameter U to T 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. end note]
*
* Both src and dst are reference types and there is a builtin explicit conversion from
* src to dst.
* Or src is a reference type and dst is a base type of src (in which case the conversion is
* implicit as well).
* Or dst is a reference type and src is a base type of dst.
*
* The latter two cases can happen with type variables even though the other type variable is not
* a reference type.
***************************************************************************************************/
public static bool FExpRefConv(SymbolLoader loader, CType typeSrc, CType typeDst)
{
Debug.Assert(typeSrc != null);
Debug.Assert(typeDst != null);
if (typeSrc.IsRefType() && typeDst.IsRefType())
{
// is there an implicit reference conversion in either direction?
// this handles the bulk of the cases ...
if (loader.HasIdentityOrImplicitReferenceConversion(typeSrc, typeDst) ||
loader.HasIdentityOrImplicitReferenceConversion(typeDst, typeSrc))
{
return(true);
}
// For a type-parameter T that is known to be a reference type (§25.7), the following explicit reference conversions exist:
// • From any interface-type to T.
// • From T to any interface-type I provided there isn’t already an implicit reference conversion from T to I.
if (typeSrc.isInterfaceType() && typeDst is TypeParameterType)
{
return(true);
}
if (typeSrc is TypeParameterType && typeDst.isInterfaceType())
{
return(true);
}
// * From any class-type S to any interface-type T, provided S is not sealed
// * From any interface-type S to any class-type T, provided T is not sealed
// * From any interface-type S to any interface-type T, provided S is not derived from T.
if (typeSrc is AggregateType atSrc && typeDst is AggregateType atDst)
{
AggregateSymbol aggSrc = atSrc.getAggregate();
AggregateSymbol aggDest = atDst.getAggregate();
if ((aggSrc.IsClass() && !aggSrc.IsSealed() && aggDest.IsInterface()) ||
(aggSrc.IsInterface() && aggDest.IsClass() && !aggDest.IsSealed()) ||
(aggSrc.IsInterface() && aggDest.IsInterface()))
{
return(true);
}
}
if (typeSrc is ArrayType arrSrc)
{
// * From an array-type S with an element type SE to an array-type T with an element type TE, provided all of the following are true:
// o S and T differ only in element type. (In other words, S and T have the same number of dimensions.)
// o An explicit reference conversion exists from SE to TE.
if (typeDst is ArrayType arrDst)
{
return(arrSrc.rank == arrDst.rank &&
arrSrc.IsSZArray == arrDst.IsSZArray &&
FExpRefConv(loader, arrSrc.GetElementType(), arrDst.GetElementType()));
}
// * From a one-dimensional array-type S[] to System.Collections.Generic.IList<T>, System.Collections.Generic.IReadOnlyList<T>
// and their base interfaces, provided there is an explicit reference conversion from S to T.
if (!arrSrc.IsSZArray ||
!typeDst.isInterfaceType())
{
return(false);
}
AggregateType aggDst = (AggregateType)typeDst;
TypeArray typeArgsAll = aggDst.GetTypeArgsAll();
if (typeArgsAll.Count != 1)
{
return(false);
}
AggregateSymbol aggIList = loader.GetPredefAgg(PredefinedType.PT_G_ILIST);
AggregateSymbol aggIReadOnlyList = loader.GetPredefAgg(PredefinedType.PT_G_IREADONLYLIST);
if ((aggIList == null ||
!SymbolLoader.IsBaseAggregate(aggIList, aggDst.getAggregate())) &&
(aggIReadOnlyList == null ||
!SymbolLoader.IsBaseAggregate(aggIReadOnlyList, aggDst.getAggregate())))
{
return(false);
}
return(FExpRefConv(loader, arrSrc.GetElementType(), typeArgsAll[0]));
}
if (typeDst is ArrayType arrayDest && typeSrc is AggregateType aggtypeSrc)
{
// * From System.Array and the interfaces it implements, to any array-type.
if (loader.HasIdentityOrImplicitReferenceConversion(loader.GetPredefindType(PredefinedType.PT_ARRAY), typeSrc))
{
return(true);
}
// * From System.Collections.Generic.IList<T>, System.Collections.Generic.IReadOnlyList<T> and their base interfaces to a
// one-dimensional array-type S[], provided there is an implicit or explicit reference conversion from S[] to
// System.Collections.Generic.IList<T> or System.Collections.Generic.IReadOnlyList<T>. This is precisely when either S and T
// are the same type or there is an implicit or explicit reference conversion from S to T.
if (!arrayDest.IsSZArray || !typeSrc.isInterfaceType() ||
aggtypeSrc.GetTypeArgsAll().Count != 1)
{
return(false);
}
AggregateSymbol aggIList = loader.GetPredefAgg(PredefinedType.PT_G_ILIST);
AggregateSymbol aggIReadOnlyList = loader.GetPredefAgg(PredefinedType.PT_G_IREADONLYLIST);
if ((aggIList == null ||
!SymbolLoader.IsBaseAggregate(aggIList, aggtypeSrc.getAggregate())) &&
(aggIReadOnlyList == null ||
!SymbolLoader.IsBaseAggregate(aggIReadOnlyList, aggtypeSrc.getAggregate())))
{
return(false);
}
CType typeArr = arrayDest.GetElementType();
CType typeLst = aggtypeSrc.GetTypeArgsAll()[0];
Debug.Assert(!(typeArr is MethodGroupType));
return(typeArr == typeLst || FExpRefConv(loader, typeArr, typeLst));
}
if (HasGenericDelegateExplicitReferenceConversion(loader, typeSrc, typeDst))
{
return(true);
}
}
else if (typeSrc.IsRefType())
{
// conversion of T . U, where T : class, U
// .. these constraints implies where U : class
return(loader.HasIdentityOrImplicitReferenceConversion(typeSrc, typeDst));
}
else if (typeDst.IsRefType())
{
// conversion of T . U, where U : class, T
// .. these constraints implies where T : class
return(loader.HasIdentityOrImplicitReferenceConversion(typeDst, typeSrc));
}
return(false);
}
public CType SubstType(CType typeSrc, AggregateType atsCls, TypeArray typeArgsMeth)
{
return(SubstType(typeSrc, atsCls?.GetTypeArgsAll(), typeArgsMeth));
}
public CType SubstType(CType typeSrc, AggregateType atsCls, TypeArray typeArgsMeth)
{
return SubstType(typeSrc, atsCls != null ? atsCls.GetTypeArgsAll() : null, typeArgsMeth);
}
public SubstContext(AggregateType type, TypeArray typeArgsMeth, SubstTypeFlags grfst)
{
Init(type != null ? type.GetTypeArgsAll() : null, typeArgsMeth, grfst);
}
public TypeArray SubstTypeArray(TypeArray taSrc, AggregateType atsCls, TypeArray typeArgsMeth)
{
return SubstTypeArray(taSrc, atsCls != null ? atsCls.GetTypeArgsAll() : null, typeArgsMeth);
}
private SubstContext(AggregateType type, TypeArray typeArgsMeth, SubstTypeFlags grfst)
{
Init(type?.GetTypeArgsAll(), typeArgsMeth, grfst);
}
public NullableType GetNubFromNullable(AggregateType ats)
{
Debug.Assert(ats.isPredefType(PredefinedType.PT_G_OPTIONAL));
return GetNullable(ats.GetTypeArgsAll().Item(0));
}
////////////////////////////////////////////////////////////////////////////////
private void UpperBoundTypeArgumentInference(
AggregateType pSource, AggregateType pDest)
{
// SPEC: The choice of inference for the i-th CType argument is made
// SPEC: based on the declaration of the i-th CType parameter of C, as
// SPEC: follows:
// SPEC: if Ui is known to be of reference CType and the i-th CType parameter
// SPEC: was declared as covariant then an upper-bound inference is made.
// SPEC: if Ui is known to be of reference CType and the i-th CType parameter
// SPEC: was declared as contravariant then a lower-bound inference is made.
// SPEC: otherwise, an exact inference is made.
Debug.Assert(pSource != null);
Debug.Assert(pDest != null);
Debug.Assert(pSource.GetOwningAggregate() == pDest.GetOwningAggregate());
TypeArray pTypeParams = pSource.GetOwningAggregate().GetTypeVarsAll();
TypeArray pSourceArgs = pSource.GetTypeArgsAll();
TypeArray pDestArgs = pDest.GetTypeArgsAll();
Debug.Assert(pTypeParams != null);
Debug.Assert(pSourceArgs != null);
Debug.Assert(pDestArgs != null);
Debug.Assert(pTypeParams.size == pSourceArgs.size);
Debug.Assert(pTypeParams.size == pDestArgs.size);
for (int arg = 0; arg < pSourceArgs.size; ++arg)
{
TypeParameterType pTypeParam = pTypeParams.ItemAsTypeParameterType(arg);
CType pSourceArg = pSourceArgs.Item(arg);
CType pDestArg = pDestArgs.Item(arg);
if (pSourceArg.IsRefType() && pTypeParam.Covariant)
{
UpperBoundInference(pSourceArg, pDestArg);
}
else if (pSourceArg.IsRefType() && pTypeParam.Contravariant)
{
LowerBoundInference(pSourceArgs.Item(arg), pDestArgs.Item(arg));
}
else
{
ExactInference(pSourceArgs.Item(arg), pDestArgs.Item(arg));
}
}
}
public AggregateType GetAggregate(AggregateSymbol agg, AggregateType atsOuter, TypeArray typeArgs)
{
Debug.Assert(agg.GetTypeManager() == this);
Debug.Assert(atsOuter == null || atsOuter.getAggregate() == agg.Parent, "");
if (typeArgs == null)
{
typeArgs = BSYMMGR.EmptyTypeArray();
}
Debug.Assert(agg.GetTypeVars().Count == typeArgs.Count);
Name name = _BSymmgr.GetNameFromPtrs(typeArgs, atsOuter);
Debug.Assert(name != null);
AggregateType pAggregate = _typeTable.LookupAggregate(name, agg);
if (pAggregate == null)
{
pAggregate = _typeFactory.CreateAggregateType(
name,
agg,
typeArgs,
atsOuter
);
Debug.Assert(!pAggregate.fConstraintsChecked && !pAggregate.fConstraintError);
pAggregate.SetErrors(false);
_typeTable.InsertAggregate(name, agg, pAggregate);
// If we have a generic type definition, then we need to set the
// base class to be our current base type, and use that to calculate
// our agg type and its base, then set it to be the generic version of the
// base type. This is because:
//
// Suppose we have Foo<T> : IFoo<T>
//
// Initially, the BaseType will be IFoo<Foo.T>, which gives us the substitution
// that we want to use for our agg type's base type. However, in the Symbol chain,
// we want the base type to be IFoo<IFoo.T>. Thats why we need to do this little trick.
//
// If we don't have a generic type definition, then we just need to set our base
// class. This is so that if we have a base type that's generic, we'll be
// getting the correctly instantiated base type.
var baseType = pAggregate.AssociatedSystemType?.BaseType;
if (baseType != null)
{
// Store the old base class.
AggregateType oldBaseType = agg.GetBaseClass();
agg.SetBaseClass(_symbolTable.GetCTypeFromType(baseType) as AggregateType);
pAggregate.GetBaseClass(); // Get the base type for the new agg type we're making.
agg.SetBaseClass(oldBaseType);
}
}
else
{
Debug.Assert(!pAggregate.HasErrors());
}
Debug.Assert(pAggregate.getAggregate() == agg);
Debug.Assert(pAggregate.GetTypeArgsThis() != null && pAggregate.GetTypeArgsAll() != null);
Debug.Assert(pAggregate.GetTypeArgsThis() == typeArgs);
return(pAggregate);
}
private bool IsDelegateType(CType pSrcType, AggregateType pAggType)
{
CType pInstantiatedType = GetSymbolLoader().GetTypeManager().SubstType(pSrcType, pAggType, pAggType.GetTypeArgsAll());
return(pInstantiatedType.isDelegateType());
}
public NullableType GetNubFromNullable(AggregateType ats)
{
Debug.Assert(ats.isPredefType(PredefinedType.PT_G_OPTIONAL));
return(GetNullable(ats.GetTypeArgsAll()[0]));
}