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 HasBaseConversion(CType pSource, CType pDest)
{
// By a "base conversion" we mean:
//
// * an identity conversion
// * an implicit reference conversion
// * an implicit boxing conversion
// * an implicit type parameter conversion
//
// In other words, these are conversions that can be made to a base
// class, base interface or co/contravariant type without any change in
// representation other than boxing. A conversion from, say, int to double,
// is NOT a "base conversion", because representation is changed. A conversion
// from, say, lambda to expression tree is not a "base conversion" because
// do not have a type.
//
// The existence of a base conversion depends solely upon the source and
// destination types, not the source expression.
//
// This notion is not found in the spec but it is useful in the implementation.
if (pSource.IsAggregateType() && pDest.isPredefType(PredefinedType.PT_OBJECT))
{
// If we are going from any aggregate type (class, struct, interface, enum or delegate)
// to object, we immediately return true. This may seem like a mere optimization --
// after all, if we have an aggregate then we have some kind of implicit conversion
// to object.
//
// However, it is not a mere optimization; this introduces a control flow change
// in error reporting scenarios for unresolved type forwarders. If a type forwarder
// cannot be resolved then the resulting type symbol will be an aggregate, but
// we will not be able to classify it into class, struct, etc.
//
// We know that we will have an error in this case; we do not wish to compound
// that error by giving a spurious "you cannot convert this thing to object"
// error, which, after all, will go away when the type forwarding problem is
// fixed.
return(true);
}
if (HasIdentityOrImplicitReferenceConversion(pSource, pDest))
{
return(true);
}
if (HasImplicitBoxingConversion(pSource, pDest))
{
return(true);
}
if (pSource.IsTypeParameterType() &&
HasImplicitTypeParameterBaseConversion(pSource.AsTypeParameterType(), pDest))
{
return(true);
}
return(false);
}
private AggCastResult bindExplicitConversionBetweenAggregates(AggregateType aggTypeDest)
{
// 13.2.3
//
// 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.
Debug.Assert(_typeSrc != null);
Debug.Assert(aggTypeDest != null);
if (!_typeSrc.IsAggregateType())
{
return(AggCastResult.Failure);
}
AggregateSymbol aggSrc = _typeSrc.AsAggregateType().getAggregate();
AggregateSymbol aggDest = aggTypeDest.getAggregate();
if (GetSymbolLoader().HasBaseConversion(aggTypeDest, _typeSrc.AsAggregateType()))
{
if (_needsExprDest)
{
if (aggDest.IsValueType() && aggSrc.getThisType().fundType() == FUNDTYPE.FT_REF)
{
_binder.bindSimpleCast(_exprSrc, _exprTypeDest, out _exprDest, EXPRFLAG.EXF_UNBOX);
}
else
{
_binder.bindSimpleCast(_exprSrc, _exprTypeDest, out _exprDest, EXPRFLAG.EXF_REFCHECK | (_exprSrc?.Flags & EXPRFLAG.EXF_CANTBENULL ?? 0));
}
}
return(AggCastResult.Success);
}
if ((aggSrc.IsClass() && !aggSrc.IsSealed() && aggDest.IsInterface()) ||
(aggSrc.IsInterface() && aggDest.IsClass() && !aggDest.IsSealed()) ||
(aggSrc.IsInterface() && aggDest.IsInterface()) ||
CConversions.HasGenericDelegateExplicitReferenceConversion(GetSymbolLoader(), _typeSrc, aggTypeDest))
{
if (_needsExprDest)
{
_binder.bindSimpleCast(_exprSrc, _exprTypeDest, out _exprDest, EXPRFLAG.EXF_REFCHECK | (_exprSrc?.Flags & EXPRFLAG.EXF_CANTBENULL ?? 0));
}
return(AggCastResult.Success);
}
return(AggCastResult.Failure);
}
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);
}
public static IEnumerable <CType> AllPossibleInterfaces(this CType type)
{
Debug.Assert(type != null);
if (type.IsAggregateType())
{
foreach (CType t in type.AsAggregateType().TypeAndBaseClassInterfaces())
{
yield return(t);
}
}
else if (type.IsTypeParameterType())
{
foreach (CType t in type.AsTypeParameterType().GetEffectiveBaseClass().TypeAndBaseClassInterfaces())
{
yield return(t);
}
foreach (CType t in type.AsTypeParameterType().GetInterfaceBounds().AllConstraintInterfaces())
{
yield return(t);
}
}
}
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);
}
/***************************************************************************************************
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.IsTypeParameterType())
{
return true;
}
if (typeSrc.IsTypeParameterType() && 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.IsAggregateType() && typeDst.IsAggregateType())
{
AggregateSymbol aggSrc = typeSrc.AsAggregateType().getAggregate();
AggregateSymbol aggDest = typeDst.AsAggregateType().getAggregate();
if ((aggSrc.IsClass() && !aggSrc.IsSealed() && aggDest.IsInterface()) ||
(aggSrc.IsInterface() && aggDest.IsClass() && !aggDest.IsSealed()) ||
(aggSrc.IsInterface() && aggDest.IsInterface()))
{
return true;
}
}
// * 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 (typeSrc.IsArrayType() && typeDst.IsArrayType())
{
return typeSrc.AsArrayType().rank == typeDst.AsArrayType().rank && FExpRefConv(loader, typeSrc.AsArrayType().GetElementType(), typeDst.AsArrayType().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 (typeSrc.IsArrayType())
{
if (typeSrc.AsArrayType().rank != 1 ||
!typeDst.isInterfaceType() || typeDst.AsAggregateType().GetTypeArgsAll().Size != 1)
{
return false;
}
AggregateSymbol aggIList = loader.GetOptPredefAgg(PredefinedType.PT_G_ILIST);
AggregateSymbol aggIReadOnlyList = loader.GetOptPredefAgg(PredefinedType.PT_G_IREADONLYLIST);
if ((aggIList == null ||
!loader.IsBaseAggregate(aggIList, typeDst.AsAggregateType().getAggregate())) &&
(aggIReadOnlyList == null ||
!loader.IsBaseAggregate(aggIReadOnlyList, typeDst.AsAggregateType().getAggregate())))
{
return false;
}
return FExpRefConv(loader, typeSrc.AsArrayType().GetElementType(), typeDst.AsAggregateType().GetTypeArgsAll().Item(0));
}
if (typeDst.IsArrayType() && typeSrc.IsAggregateType())
{
// * From System.Array and the interfaces it implements, to any array-type.
if (loader.HasIdentityOrImplicitReferenceConversion(loader.GetReqPredefType(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.
ArrayType arrayDest = typeDst.AsArrayType();
AggregateType aggtypeSrc = typeSrc.AsAggregateType();
if (arrayDest.rank != 1 || !typeSrc.isInterfaceType() ||
aggtypeSrc.GetTypeArgsAll().Size != 1)
{
return false;
}
AggregateSymbol aggIList = loader.GetOptPredefAgg(PredefinedType.PT_G_ILIST);
AggregateSymbol aggIReadOnlyList = loader.GetOptPredefAgg(PredefinedType.PT_G_IREADONLYLIST);
if ((aggIList == null ||
!loader.IsBaseAggregate(aggIList, aggtypeSrc.getAggregate())) &&
(aggIReadOnlyList == null ||
!loader.IsBaseAggregate(aggIReadOnlyList, aggtypeSrc.getAggregate())))
{
return false;
}
CType typeArr = arrayDest.GetElementType();
CType typeLst = aggtypeSrc.GetTypeArgsAll().Item(0);
Debug.Assert(!typeArr.IsNeverSameType());
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, CType typeCls, TypeArray typeArgsMeth)
{
return SubstType(typeSrc, typeCls.IsAggregateType() ? typeCls.AsAggregateType().GetTypeArgsAll() : null, typeArgsMeth);
}
public bool IsBaseInterface(CType pDerived, CType pBase)
{
Debug.Assert(pDerived != null);
Debug.Assert(pBase != null);
if (!pBase.isInterfaceType())
{
return false;
}
if (!pDerived.IsAggregateType())
{
return false;
}
AggregateType atsDer = pDerived.AsAggregateType();
while (atsDer != null)
{
TypeArray ifacesAll = atsDer.GetIfacesAll();
for (int i = 0; i < ifacesAll.Size; i++)
{
if (AreTypesEqualForConversion(ifacesAll.Item(i), pBase))
{
return true;
}
}
atsDer = atsDer.GetBaseClass();
}
return false;
}
/////////////////////////////////////////////////////////////////////////////////
public static MethodOrPropertySymbol FindMostDerivedMethod(
SymbolLoader symbolLoader,
MethodOrPropertySymbol pMethProp,
CType pType)
{
MethodSymbol method;
bool bIsIndexer = false;
if (pMethProp.IsMethodSymbol())
{
method = pMethProp.AsMethodSymbol();
}
else
{
PropertySymbol prop = pMethProp.AsPropertySymbol();
method = prop.methGet != null ? prop.methGet : prop.methSet;
if (method == null)
{
return null;
}
bIsIndexer = prop.isIndexer();
}
if (!method.isVirtual)
{
return method;
}
if (pType == null)
{
// This must be a static call.
return method;
}
// Now get the slot method.
if (method.swtSlot != null && method.swtSlot.Meth() != null)
{
method = method.swtSlot.Meth();
}
if (!pType.IsAggregateType())
{
// Not something that can have overrides anyway.
return method;
}
for (AggregateSymbol pAggregate = pType.AsAggregateType().GetOwningAggregate();
pAggregate != null && pAggregate.GetBaseAgg() != null;
pAggregate = pAggregate.GetBaseAgg())
{
for (MethodOrPropertySymbol meth = symbolLoader.LookupAggMember(method.name, pAggregate, symbmask_t.MASK_MethodSymbol | symbmask_t.MASK_PropertySymbol).AsMethodOrPropertySymbol();
meth != null;
meth = symbolLoader.LookupNextSym(meth, pAggregate, symbmask_t.MASK_MethodSymbol | symbmask_t.MASK_PropertySymbol).AsMethodOrPropertySymbol())
{
if (!meth.isOverride)
{
continue;
}
if (meth.swtSlot.Sym != null && meth.swtSlot.Sym == method)
{
if (bIsIndexer)
{
Debug.Assert(meth.IsMethodSymbol());
return meth.AsMethodSymbol().getProperty();
}
else
{
return meth;
}
}
}
}
// If we get here, it means we can have two cases: one is that we have
// a delegate. This is because the delegate invoke method is virtual and is
// an override, but we wont have the slots set up correctly, and will
// not find the base type in the inheritance hierarchy. The second is that
// we're calling off of the base itself.
Debug.Assert(method.parent.IsAggregateSymbol());
return method;
}
////////////////////////////////////////////////////////////////////////////////
private bool UpperBoundConstructedInference(CType pSource, CType pDest)
{
if (!pSource.IsAggregateType())
{
return false;
}
AggregateType pConstructedSource = pSource.AsAggregateType();
TypeArray pSourceArgs = pConstructedSource.GetTypeArgsAll();
if (pSourceArgs.size == 0)
{
return false;
}
// SPEC: Otherwise, if V is a constructed CType C<V1...Vk> and U is
// SPEC: C<U1...Uk> then an exact inference,
// SPEC: lower bound inference or upper bound inference
// SPEC: is made from each Ui to the corresponding Vi.
if (pDest.IsAggregateType() &&
pConstructedSource.GetOwningAggregate() == pDest.AsAggregateType().GetOwningAggregate())
{
if (pDest.isInterfaceType() || pDest.isDelegateType())
{
UpperBoundTypeArgumentInference(pConstructedSource, pDest.AsAggregateType());
}
else
{
ExactTypeArgumentInference(pConstructedSource, pDest.AsAggregateType());
}
return true;
}
// SPEC: Otherwise, if U is a class CType C<U1...Uk> and V is a class CType which
// SPEC: inherits directly or indirectly from C<V1...Vk> then an exact ...
if (UpperBoundClassInference(pConstructedSource, pDest))
{
return true;
}
// SPEC: Otherwise, if U is an interface CType C<U1...Uk> and V is a class CType
// SPEC: or struct CType and there is a unique set V1...Vk such that V directly
// SPEC: or indirectly implements C<V1...Vk> then an exact ...
// SPEC: ... and U is an interface CType ...
if (UpperBoundInterfaceInference(pConstructedSource, pDest))
{
return true;
}
return false;
}
/***************************************************************************************************
Lookup must be called before anything else can be called.
typeSrc - Must be an AggregateType or TypeParameterType.
obj - the expression through which the member is being accessed. This is used for accessibility
of protected members and for constructing a MEMGRP from the results of the lookup.
It is legal for obj to be an EK_CLASS, in which case it may be used for accessibility, but
will not be used for MEMGRP construction.
symWhere - the symbol from with the name is being accessed (for checking accessibility).
name - the name to look for.
arity - the number of type args specified. Only members that support this arity are found.
Note that when arity is zero, all methods are considered since we do type argument
inferencing.
flags - See MemLookFlags.
TypeVarsAllowed only applies to the most derived type (not base types).
***************************************************************************************************/
public bool Lookup(CSemanticChecker checker, CType typeSrc, EXPR obj, ParentSymbol symWhere, Name name, int arity, MemLookFlags flags)
{
Debug.Assert((flags & ~MemLookFlags.All) == 0);
Debug.Assert(obj == null || obj.type != null);
Debug.Assert(typeSrc.IsAggregateType() || typeSrc.IsTypeParameterType());
Debug.Assert(checker != null);
_prgtype = _rgtypeStart;
// Save the inputs for error handling, etc.
_pSemanticChecker = checker;
_pSymbolLoader = checker.GetSymbolLoader();
_typeSrc = typeSrc;
_obj = (obj != null && !obj.isCLASS()) ? obj : null;
_symWhere = symWhere;
_name = name;
_arity = arity;
_flags = flags;
if ((_flags & MemLookFlags.BaseCall) != 0)
_typeQual = null;
else if ((_flags & MemLookFlags.Ctor) != 0)
_typeQual = _typeSrc;
else if (obj != null)
_typeQual = (CType)obj.type;
else
_typeQual = null;
// Determine what to search.
AggregateType typeCls1 = null;
AggregateType typeIface = null;
TypeArray ifaces = BSYMMGR.EmptyTypeArray();
AggregateType typeCls2 = null;
if (typeSrc.IsTypeParameterType())
{
Debug.Assert((_flags & (MemLookFlags.Ctor | MemLookFlags.NewObj | MemLookFlags.Operator | MemLookFlags.BaseCall | MemLookFlags.TypeVarsAllowed)) == 0);
_flags &= ~MemLookFlags.TypeVarsAllowed;
ifaces = typeSrc.AsTypeParameterType().GetInterfaceBounds();
typeCls1 = typeSrc.AsTypeParameterType().GetEffectiveBaseClass();
if (ifaces.size > 0 && typeCls1.isPredefType(PredefinedType.PT_OBJECT))
typeCls1 = null;
}
else if (!typeSrc.isInterfaceType())
{
typeCls1 = typeSrc.AsAggregateType();
if (typeCls1.IsWindowsRuntimeType())
{
ifaces = typeCls1.GetWinRTCollectionIfacesAll(GetSymbolLoader());
}
}
else
{
Debug.Assert(typeSrc.isInterfaceType());
Debug.Assert((_flags & (MemLookFlags.Ctor | MemLookFlags.NewObj | MemLookFlags.Operator | MemLookFlags.BaseCall)) == 0);
typeIface = typeSrc.AsAggregateType();
ifaces = typeIface.GetIfacesAll();
}
if (typeIface != null || ifaces.size > 0)
typeCls2 = GetSymbolLoader().GetReqPredefType(PredefinedType.PT_OBJECT);
// Search the class first (except possibly object).
if (typeCls1 == null || LookupInClass(typeCls1, ref typeCls2))
{
// Search the interfaces.
if ((typeIface != null || ifaces.size > 0) && LookupInInterfaces(typeIface, ifaces) && typeCls2 != null)
{
// Search object last.
Debug.Assert(typeCls2 != null && typeCls2.isPredefType(PredefinedType.PT_OBJECT));
AggregateType result = null;
LookupInClass(typeCls2, ref result);
}
}
// if we are requested with extension methods
_results = new CMemberLookupResults(GetAllTypes(), _name);
return !FError();
}
//
// 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 bool ExactConstructedInference(CType pSource, CType pDest)
{
// SPEC: Otherwise, if V is a constructed CType C<V1...Vk> and U is a constructed
// SPEC: CType C<U1...Uk> then an exact inference
// SPEC: is made from each Ui to the corresponding Vi.
if (!pSource.IsAggregateType() || !pDest.IsAggregateType())
{
return false;
}
AggregateType pConstructedSource = pSource.AsAggregateType();
AggregateType pConstructedDest = pDest.AsAggregateType();
if (pConstructedSource.GetOwningAggregate() != pConstructedDest.GetOwningAggregate())
{
return false;
}
ExactTypeArgumentInference(pConstructedSource, pConstructedDest);
return true;
}
/***************************************************************************************************
* 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.IsTypeParameterType())
{
return(true);
}
if (typeSrc.IsTypeParameterType() && 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.IsAggregateType() && typeDst.IsAggregateType())
{
AggregateSymbol aggSrc = typeSrc.AsAggregateType().getAggregate();
AggregateSymbol aggDest = typeDst.AsAggregateType().getAggregate();
if ((aggSrc.IsClass() && !aggSrc.IsSealed() && aggDest.IsInterface()) ||
(aggSrc.IsInterface() && aggDest.IsClass() && !aggDest.IsSealed()) ||
(aggSrc.IsInterface() && aggDest.IsInterface()))
{
return(true);
}
}
// * 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 (typeSrc.IsArrayType() && typeDst.IsArrayType())
{
return(typeSrc.AsArrayType().rank == typeDst.AsArrayType().rank&& FExpRefConv(loader, typeSrc.AsArrayType().GetElementType(), typeDst.AsArrayType().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 (typeSrc.IsArrayType())
{
if (typeSrc.AsArrayType().rank != 1 ||
!typeDst.isInterfaceType() || typeDst.AsAggregateType().GetTypeArgsAll().Size != 1)
{
return(false);
}
AggregateSymbol aggIList = loader.GetOptPredefAgg(PredefinedType.PT_G_ILIST);
AggregateSymbol aggIReadOnlyList = loader.GetOptPredefAgg(PredefinedType.PT_G_IREADONLYLIST);
if ((aggIList == null ||
!loader.IsBaseAggregate(aggIList, typeDst.AsAggregateType().getAggregate())) &&
(aggIReadOnlyList == null ||
!loader.IsBaseAggregate(aggIReadOnlyList, typeDst.AsAggregateType().getAggregate())))
{
return(false);
}
return(FExpRefConv(loader, typeSrc.AsArrayType().GetElementType(), typeDst.AsAggregateType().GetTypeArgsAll().Item(0)));
}
if (typeDst.IsArrayType() && typeSrc.IsAggregateType())
{
// * From System.Array and the interfaces it implements, to any array-type.
if (loader.HasIdentityOrImplicitReferenceConversion(loader.GetReqPredefType(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.
ArrayType arrayDest = typeDst.AsArrayType();
AggregateType aggtypeSrc = typeSrc.AsAggregateType();
if (arrayDest.rank != 1 || !typeSrc.isInterfaceType() ||
aggtypeSrc.GetTypeArgsAll().Size != 1)
{
return(false);
}
AggregateSymbol aggIList = loader.GetOptPredefAgg(PredefinedType.PT_G_ILIST);
AggregateSymbol aggIReadOnlyList = loader.GetOptPredefAgg(PredefinedType.PT_G_IREADONLYLIST);
if ((aggIList == null ||
!loader.IsBaseAggregate(aggIList, aggtypeSrc.getAggregate())) &&
(aggIReadOnlyList == null ||
!loader.IsBaseAggregate(aggIReadOnlyList, aggtypeSrc.getAggregate())))
{
return(false);
}
CType typeArr = arrayDest.GetElementType();
CType typeLst = aggtypeSrc.GetTypeArgsAll().Item(0);
Debug.Assert(!typeArr.IsNeverSameType());
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);
}
////////////////////////////////////////////////////////////////////////////////
// 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();
}
}
public bool HasBaseConversion(CType pSource, CType pDest)
{
// By a "base conversion" we mean:
//
// * an identity conversion
// * an implicit reference conversion
// * an implicit boxing conversion
// * an implicit type parameter conversion
//
// In other words, these are conversions that can be made to a base
// class, base interface or co/contravariant type without any change in
// representation other than boxing. A conversion from, say, int to double,
// is NOT a "base conversion", because representation is changed. A conversion
// from, say, lambda to expression tree is not a "base conversion" because
// do not have a type.
//
// The existence of a base conversion depends solely upon the source and
// destination types, not the source expression.
//
// This notion is not found in the spec but it is useful in the implementation.
if (pSource.IsAggregateType() && pDest.isPredefType(PredefinedType.PT_OBJECT))
{
// If we are going from any aggregate type (class, struct, interface, enum or delegate)
// to object, we immediately return true. This may seem like a mere optimization --
// after all, if we have an aggregate then we have some kind of implicit conversion
// to object.
//
// However, it is not a mere optimization; this introduces a control flow change
// in error reporting scenarios for unresolved type forwarders. If a type forwarder
// cannot be resolved then the resulting type symbol will be an aggregate, but
// we will not be able to classify it into class, struct, etc.
//
// We know that we will have an error in this case; we do not wish to compound
// that error by giving a spurious "you cannot convert this thing to object"
// error, which, after all, will go away when the type forwarding problem is
// fixed.
return true;
}
if (HasIdentityOrImplicitReferenceConversion(pSource, pDest))
{
return true;
}
if (HasImplicitBoxingConversion(pSource, pDest))
{
return true;
}
if (pSource.IsTypeParameterType() &&
HasImplicitTypeParameterBaseConversion(pSource.AsTypeParameterType(), pDest))
{
return true;
}
return false;
}
private bool HasAnyBaseInterfaceConversion(CType pDerived, CType pBase)
{
if (!pBase.isInterfaceType())
{
return false;
}
if (!pDerived.IsAggregateType())
{
return false;
}
AggregateType atsDer = pDerived.AsAggregateType();
while (atsDer != null)
{
TypeArray ifacesAll = atsDer.GetIfacesAll();
for (int i = 0; i < ifacesAll.size; i++)
{
if (HasInterfaceConversion(ifacesAll.Item(i).AsAggregateType(), pBase.AsAggregateType()))
{
return true;
}
}
atsDer = atsDer.GetBaseClass();
}
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;
}
public bool SubstEqualTypes(CType typeDst, CType typeSrc, CType typeCls, TypeArray typeArgsMeth)
{
return SubstEqualTypes(typeDst, typeSrc, typeCls.IsAggregateType() ? typeCls.AsAggregateType().GetTypeArgsAll() : null, typeArgsMeth, SubstTypeFlags.NormNone);
}
// 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);
}
// !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
// 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;
}
protected void ErrAppendParentType(CType pType, SubstContext pctx)
{
if (pType.IsErrorType())
{
if (pType.AsErrorType().HasTypeParent())
{
ErrAppendType(pType.AsErrorType().GetTypeParent(), null);
ErrAppendChar('.');
}
else
{
ErrAppendParentCore(pType.AsErrorType().GetNSParent(), pctx);
}
}
else if (pType.IsAggregateType())
{
ErrAppendParentCore(pType.AsAggregateType().GetOwningAggregate(), pctx);
}
else if (pType.GetBaseOrParameterOrElementType() != null)
{
ErrAppendType(pType.GetBaseOrParameterOrElementType(), null);
ErrAppendChar('.');
}
}
////////////////////////////////////////////////////////////////////////////////
/*
bool LowerBoundNullableInference(CType pSource, CType pDest)
{
// SPEC ISSUE: As noted above, the spec does not clearly call out how
// SPEC ISSUE: to do CType inference to a nullable target. I propose the
// SPEC ISSUE: following:
// SPEC ISSUE:
// SPEC ISSUE: Otherwise, if V is nullable CType V1? and U is a
// SPEC ISSUE: non-nullable struct CType then an exact inference is made from U to V1.
if (!pDest.IsNullableType() || !pSource.isStructType() || pSource.IsNullableType())
{
return false;
}
ExactInference(pSource, pDest.AsNullableType().GetUnderlyingType());
return true;
}
* */
////////////////////////////////////////////////////////////////////////////////
private bool LowerBoundConstructedInference(CType pSource, CType pDest)
{
if (!pDest.IsAggregateType())
{
return false;
}
AggregateType pConstructedDest = pDest.AsAggregateType();
TypeArray pDestArgs = pConstructedDest.GetTypeArgsAll();
if (pDestArgs.size == 0)
{
return false;
}
// SPEC: Otherwise, if V is a constructed class or struct CType C<V1...Vk>
// SPEC: and U is C<U1...Uk> then an exact inference
// SPEC: is made from each Ui to the corresponding Vi.
// SPEC: Otherwise, if V is a constructed interface or delegate CType C<V1...Vk>
// SPEC: and U is C<U1...Uk> then an exact inference,
// SPEC: lower bound inference or upper bound inference
// SPEC: is made from each Ui to the corresponding Vi.
if (pSource.IsAggregateType() &&
pSource.AsAggregateType().GetOwningAggregate() == pConstructedDest.GetOwningAggregate())
{
if (pSource.isInterfaceType() || pSource.isDelegateType())
{
LowerBoundTypeArgumentInference(pSource.AsAggregateType(), pConstructedDest);
}
else
{
ExactTypeArgumentInference(pSource.AsAggregateType(), pConstructedDest);
}
return true;
}
// SPEC: Otherwise, if V is a class CType C<V1...Vk> and U is a class CType which
// SPEC: inherits directly or indirectly from C<U1...Uk> then an exact ...
// SPEC: ... and U is a CType parameter with effective base class ...
// SPEC: ... and U is a CType parameter with an effective base class which inherits ...
if (LowerBoundClassInference(pSource, pConstructedDest))
{
return true;
}
// SPEC: Otherwise, if V is an interface CType C<V1...Vk> and U is a class CType
// SPEC: or struct CType and there is a unique set U1...Uk such that U directly
// SPEC: or indirectly implements C<U1...Uk> then an exact ...
// SPEC: ... and U is an interface CType ...
// SPEC: ... and U is a CType parameter ...
if (LowerBoundInterfaceInference(pSource, pConstructedDest))
{
return true;
}
return false;
}
////////////////////////////////////////////////////////////////////////////////
// Determine whether the arg type satisfies the typeBnd constraint. Note that
// typeBnd could be just about any type (since we added naked type parameter
// constraints).
private static bool SatisfiesBound(CSemanticChecker checker, CType arg, CType typeBnd)
{
if (typeBnd == arg)
return true;
switch (typeBnd.GetTypeKind())
{
default:
Debug.Assert(false, "Unexpected type.");
return false;
case TypeKind.TK_VoidType:
case TypeKind.TK_PointerType:
case TypeKind.TK_ErrorType:
return false;
case TypeKind.TK_ArrayType:
case TypeKind.TK_TypeParameterType:
break;
case TypeKind.TK_NullableType:
typeBnd = typeBnd.AsNullableType().GetAts(checker.GetErrorContext());
if (null == typeBnd)
return true;
break;
case TypeKind.TK_AggregateType:
break;
}
Debug.Assert(typeBnd.IsAggregateType() || typeBnd.IsTypeParameterType() || typeBnd.IsArrayType());
switch (arg.GetTypeKind())
{
default:
return false;
case TypeKind.TK_ErrorType:
case TypeKind.TK_PointerType:
return false;
case TypeKind.TK_NullableType:
arg = arg.AsNullableType().GetAts(checker.GetErrorContext());
if (null == arg)
return true;
// Fall through.
goto case TypeKind.TK_TypeParameterType;
case TypeKind.TK_TypeParameterType:
case TypeKind.TK_ArrayType:
case TypeKind.TK_AggregateType:
return checker.GetSymbolLoader().HasBaseConversion(arg, typeBnd);
}
}
//
// 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;
}
private bool DoesTypeArgumentsContainErrorSym(CType var)
{
if (!var.IsAggregateType())
{
return false;
}
TypeArray typeVars = var.AsAggregateType().GetTypeArgsAll();
for (int i = 0; i < typeVars.size; i++)
{
CType type = typeVars.Item(i);
if (type.IsErrorType())
{
return true;
}
else if (type.IsAggregateType())
{
// If we have an agg type sym, check if its type args have errors.
if (DoesTypeArgumentsContainErrorSym(type))
{
return true;
}
}
}
return false;
}
public virtual bool CheckTypeAccess(CType type, Symbol symWhere)
{
Debug.Assert(type != null);
// Array, Ptr, Nub, etc don't matter.
type = type.GetNakedType(true);
if (!type.IsAggregateType())
{
Debug.Assert(type.IsVoidType() || type.IsErrorType() || type.IsTypeParameterType());
return true;
}
for (AggregateType ats = type.AsAggregateType(); ats != null; ats = ats.outerType)
{
if (ACCESSERROR.ACCESSERROR_NOERROR != CheckAccessCore(ats.GetOwningAggregate(), ats.outerType, symWhere, null))
{
return false;
}
}
TypeArray typeArgs = type.AsAggregateType().GetTypeArgsAll();
for (int i = 0; i < typeArgs.size; i++)
{
if (!CheckTypeAccess(typeArgs.Item(i), symWhere))
return false;
}
return true;
}
// 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;
}
/***************************************************************************************************
* Lookup must be called before anything else can be called.
*
* typeSrc - Must be an AggregateType or TypeParameterType.
* obj - the expression through which the member is being accessed. This is used for accessibility
* of protected members and for constructing a MEMGRP from the results of the lookup.
* It is legal for obj to be an EK_CLASS, in which case it may be used for accessibility, but
* will not be used for MEMGRP construction.
* symWhere - the symbol from with the name is being accessed (for checking accessibility).
* name - the name to look for.
* arity - the number of type args specified. Only members that support this arity are found.
* Note that when arity is zero, all methods are considered since we do type argument
* inferencing.
*
* flags - See MemLookFlags.
* TypeVarsAllowed only applies to the most derived type (not base types).
***************************************************************************************************/
public bool Lookup(CSemanticChecker checker, CType typeSrc, EXPR obj, ParentSymbol symWhere, Name name, int arity, MemLookFlags flags)
{
Debug.Assert((flags & ~MemLookFlags.All) == 0);
Debug.Assert(obj == null || obj.type != null);
Debug.Assert(typeSrc.IsAggregateType() || typeSrc.IsTypeParameterType());
Debug.Assert(checker != null);
_prgtype = _rgtypeStart;
// Save the inputs for error handling, etc.
_pSemanticChecker = checker;
_pSymbolLoader = checker.GetSymbolLoader();
_typeSrc = typeSrc;
_obj = (obj != null && !obj.isCLASS()) ? obj : null;
_symWhere = symWhere;
_name = name;
_arity = arity;
_flags = flags;
if ((_flags & MemLookFlags.BaseCall) != 0)
{
_typeQual = null;
}
else if ((_flags & MemLookFlags.Ctor) != 0)
{
_typeQual = _typeSrc;
}
else if (obj != null)
{
_typeQual = (CType)obj.type;
}
else
{
_typeQual = null;
}
// Determine what to search.
AggregateType typeCls1 = null;
AggregateType typeIface = null;
TypeArray ifaces = BSYMMGR.EmptyTypeArray();
AggregateType typeCls2 = null;
if (typeSrc.IsTypeParameterType())
{
Debug.Assert((_flags & (MemLookFlags.Ctor | MemLookFlags.NewObj | MemLookFlags.Operator | MemLookFlags.BaseCall | MemLookFlags.TypeVarsAllowed)) == 0);
_flags &= ~MemLookFlags.TypeVarsAllowed;
ifaces = typeSrc.AsTypeParameterType().GetInterfaceBounds();
typeCls1 = typeSrc.AsTypeParameterType().GetEffectiveBaseClass();
if (ifaces.size > 0 && typeCls1.isPredefType(PredefinedType.PT_OBJECT))
{
typeCls1 = null;
}
}
else if (!typeSrc.isInterfaceType())
{
typeCls1 = typeSrc.AsAggregateType();
if (typeCls1.IsWindowsRuntimeType())
{
ifaces = typeCls1.GetWinRTCollectionIfacesAll(GetSymbolLoader());
}
}
else
{
Debug.Assert(typeSrc.isInterfaceType());
Debug.Assert((_flags & (MemLookFlags.Ctor | MemLookFlags.NewObj | MemLookFlags.Operator | MemLookFlags.BaseCall)) == 0);
typeIface = typeSrc.AsAggregateType();
ifaces = typeIface.GetIfacesAll();
}
if (typeIface != null || ifaces.size > 0)
{
typeCls2 = GetSymbolLoader().GetReqPredefType(PredefinedType.PT_OBJECT);
}
// Search the class first (except possibly object).
if (typeCls1 == null || LookupInClass(typeCls1, ref typeCls2))
{
// Search the interfaces.
if ((typeIface != null || ifaces.size > 0) && LookupInInterfaces(typeIface, ifaces) && typeCls2 != null)
{
// Search object last.
Debug.Assert(typeCls2 != null && typeCls2.isPredefType(PredefinedType.PT_OBJECT));
AggregateType result = null;
LookupInClass(typeCls2, ref result);
}
}
// if we are requested with extension methods
_results = new CMemberLookupResults(GetAllTypes(), _name);
return(!FError());
}
// 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;
}
