|
public CreateConstant ( |
||
| pType | ||
| return | Microsoft.CSharp.RuntimeBinder.Semantics.EXPRCONSTANT | |
private bool bindImplicitConversionToEnum(AggregateType aggTypeSrc)
{
// The spec states:
// *****************
// 13.1.3 Implicit enumeration conversions
//
// An implicit enumeration conversion permits the decimal-integer-literal 0 to be converted to any
// enum-type.
// *****************
// However, we actually allow any constant zero, not just the integer literal zero, to be converted
// to enum. The reason for this is for backwards compatibility with a premature optimization
// that used to be in the binding layer. We would optimize away expressions such as 0 | blah to be
// just 0, but not erase the "is literal" bit. This meant that expression such as 0 | 0 | E.X
// would succeed rather than correctly producing an error pointing out that 0 | 0 is not a literal
// zero and therefore does not convert to any enum.
//
// We have removed the premature optimization but want old code to continue to compile. Rather than
// try to emulate the somewhat complex behaviour of the previous optimizer, it is easier to simply
// say that any compile time constant zero is convertible to any enum. This means unfortunately
// expressions such as (7-7) * 12 are convertible to enum, but frankly, that's better than having
// some terribly complex rule about what constitutes a legal zero and what doesn't.
// Note: Don't use GetConst here since the conversion only applies to bona-fide compile time constants.
if (
aggTypeSrc.OwningAggregate.GetPredefType() != PredefinedType.PT_BOOL &&
_exprSrc != null &&
_exprSrc.IsZero() &&
_exprSrc.Type.IsNumericType &&
/*(exprSrc.flags & EXF_LITERALCONST) &&*/
0 == (_flags & CONVERTTYPE.STANDARD))
{
// NOTE: This allows conversions from uint, long, ulong, float, double, and hexadecimal int
// NOTE: This is for backwards compatibility with Everett
// This is another place where we lose Expr fidelity. We shouldn't fold this
// into a constant here - we should move this to a later pass.
if (_needsExprDest)
{
_exprDest = ExprFactory.CreateConstant(_typeDest, ConstVal.GetDefaultValue(_typeDest.ConstValKind));
}
return(true);
}
return(false);
}
/////////////////////////////////////////////////////////////////////////////////
private static EXPR GenerateOptionalArgument(
SymbolLoader symbolLoader,
ExprFactory exprFactory,
MethodOrPropertySymbol methprop,
CType type,
int index)
{
CType pParamType = type;
CType pRawParamType = type.IsNullableType() ? type.AsNullableType().GetUnderlyingType() : type;
EXPR optionalArgument = null;
if (methprop.HasDefaultParameterValue(index))
{
CType pConstValType = methprop.GetDefaultParameterValueConstValType(index);
CONSTVAL cv = methprop.GetDefaultParameterValue(index);
if (pConstValType.isPredefType(PredefinedType.PT_DATETIME) &&
(pRawParamType.isPredefType(PredefinedType.PT_DATETIME) || pRawParamType.isPredefType(PredefinedType.PT_OBJECT) || pRawParamType.isPredefType(PredefinedType.PT_VALUE)))
{
// This is the specific case where we want to create a DateTime
// but the constval that stores it is a long.
AggregateType dateTimeType = symbolLoader.GetReqPredefType(PredefinedType.PT_DATETIME);
optionalArgument = exprFactory.CreateConstant(dateTimeType, new CONSTVAL(DateTime.FromBinary(cv.longVal)));
}
else if (pConstValType.isSimpleOrEnumOrString())
{
// In this case, the constval is a simple type (all the numerics, including
// decimal), or an enum or a string. This covers all the substantial values,
// and everything else that can be encoded is just null or default(something).
// For enum parameters, we create a constant of the enum type. For everything
// else, we create the appropriate constant.
if (pRawParamType.isEnumType() && pConstValType == pRawParamType.underlyingType())
{
optionalArgument = exprFactory.CreateConstant(pRawParamType, cv);
}
else
{
optionalArgument = exprFactory.CreateConstant(pConstValType, cv);
}
}
else if ((pParamType.IsRefType() || pParamType.IsNullableType()) && cv.IsNullRef())
{
// We have an "= null" default value with a reference type or a nullable type.
optionalArgument = exprFactory.CreateNull();
}
else
{
// We have a default value that is encoded as a nullref, and that nullref is
// interpreted as default(something). For instance, the pParamType could be
// a type parameter type or a non-simple value type.
optionalArgument = exprFactory.CreateZeroInit(pParamType);
}
}
else
{
// There was no default parameter specified, so generally use default(T),
// except for some cases when the parameter type in metatdata is object.
if (pParamType.isPredefType(PredefinedType.PT_OBJECT))
{
if (methprop.MarshalAsObject(index))
{
// For [opt] parameters of type object, if we have marshal(iunknown),
// marshal(idispatch), or marshal(interface), then we emit a null.
optionalArgument = exprFactory.CreateNull();
}
else
{
// Otherwise, we generate Type.Missing
AggregateSymbol agg = symbolLoader.GetOptPredefAgg(PredefinedType.PT_MISSING);
Name name = symbolLoader.GetNameManager().GetPredefinedName(PredefinedName.PN_CAP_VALUE);
FieldSymbol field = symbolLoader.LookupAggMember(name, agg, symbmask_t.MASK_FieldSymbol).AsFieldSymbol();
FieldWithType fwt = new FieldWithType(field, agg.getThisType());
EXPRFIELD exprField = exprFactory.CreateField(0, agg.getThisType(), null, 0, fwt, null);
if (agg.getThisType() != type)
{
optionalArgument = exprFactory.CreateCast(0, type, exprField);
}
else
{
optionalArgument = exprField;
}
}
}
else
{
// Every type aside from object that doesn't have a default value gets
// its default value.
optionalArgument = exprFactory.CreateZeroInit(pParamType);
}
}
Debug.Assert(optionalArgument != null);
optionalArgument.IsOptionalArgument = true;
return optionalArgument;
}
