public static bool isZero(this Expr expr)
{
return((expr.isCONSTANT_OK()) && (expr.asCONSTANT().IsZero));
}
private bool bindImplicitConversionBetweenSimpleTypes(AggregateType aggTypeSrc)
{
AggregateSymbol aggSrc = aggTypeSrc.getAggregate();
Debug.Assert(aggSrc.getThisType().isSimpleType());
Debug.Assert(_typeDest.isSimpleType());
Debug.Assert(aggSrc.IsPredefined() && _typeDest.isPredefined());
PredefinedType ptSrc = aggSrc.GetPredefType();
PredefinedType ptDest = _typeDest.getPredefType();
ConvKind convertKind;
bool fConstShrinkCast = false;
Debug.Assert((int)ptSrc < NUM_SIMPLE_TYPES && (int)ptDest < NUM_SIMPLE_TYPES);
// 13.1.7 Implicit constant expression conversions
//
// An implicit constant expression conversion permits the following conversions:
// * A constant-expression (14.16) of type int can be converted to type sbyte, byte, short,
// ushort, uint, or ulong, provided the value of the constant-expression is within the range
// of the destination type.
// * A constant-expression of type long can be converted to type ulong, provided the value of
// the constant-expression is not negative.
// Note: Don't use GetConst here since the conversion only applies to bona-fide compile time constants.
if (_exprSrc != null && _exprSrc.isCONSTANT_OK() &&
((ptSrc == PredefinedType.PT_INT && ptDest != PredefinedType.PT_BOOL && ptDest != PredefinedType.PT_CHAR) ||
(ptSrc == PredefinedType.PT_LONG && ptDest == PredefinedType.PT_ULONG)) &&
isConstantInRange(_exprSrc.asCONSTANT(), _typeDest))
{
// Special case (CLR 6.1.6): if integral constant is in range, the conversion is a legal implicit conversion.
convertKind = ConvKind.Implicit;
fConstShrinkCast = _needsExprDest && (GetConvKind(ptSrc, ptDest) != ConvKind.Implicit);
}
else if (ptSrc == ptDest)
{
// Special case: precision limiting casts to float or double
Debug.Assert(ptSrc == PredefinedType.PT_FLOAT || ptSrc == PredefinedType.PT_DOUBLE);
Debug.Assert(0 != (_flags & CONVERTTYPE.ISEXPLICIT));
convertKind = ConvKind.Implicit;
}
else
{
convertKind = GetConvKind(ptSrc, ptDest);
Debug.Assert(convertKind != ConvKind.Identity);
// identity conversion should have been handled at first.
}
if (convertKind != ConvKind.Implicit)
{
return(false);
}
// An implicit conversion exists. Do the conversion.
if (_exprSrc.GetConst() != null)
{
// Fold the constant cast if possible.
ConstCastResult result = _binder.bindConstantCast(_exprSrc, _exprTypeDest, _needsExprDest, out _exprDest, false);
if (result == ConstCastResult.Success)
{
return(true); // else, don't fold and use a regular cast, below.
}
}
if (isUserDefinedConversion(ptSrc, ptDest))
{
if (!_needsExprDest)
{
return(true);
}
// According the language, this is a standard conversion, but it is implemented
// through a user-defined conversion. Because it's a standard conversion, we don't
// test the NOUDC flag here.
return(_binder.bindUserDefinedConversion(_exprSrc, aggTypeSrc, _typeDest, _needsExprDest, out _exprDest, true));
}
if (_needsExprDest)
{
_binder.bindSimpleCast(_exprSrc, _exprTypeDest, out _exprDest);
}
return(true);
}
public static bool isNull(this Expr expr)
{
return(expr.isCONSTANT_OK() && (expr.Type.fundType() == FUNDTYPE.FT_REF) && expr.asCONSTANT().Val.IsNullRef);
}