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.
}
// REVIEW: I don't think this can ever be hit. If exprSrc is a constant then
// it's either a floating point number (which always succeeds), it's a numeric implicit
// conversion (which always succeeds), or it's a constant numeric conversion (which
// has already been checked by isConstantInRange, so should always succeed)
}
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);
}
public static bool isZero(this EXPR expr)
{
return((expr.isCONSTANT_OK()) && (expr.asCONSTANT().IsZero));
}
/////////////////////////////////////////////////////////////////////////////////
private object GetObject(EXPR pExpr)
{
if (pExpr.isCAST())
{
return GetObject(pExpr.asCAST().GetArgument());
}
else if (pExpr.isTYPEOF())
{
return pExpr.asTYPEOF().SourceType.type.AssociatedSystemType;
}
else if (pExpr.isMETHODINFO())
{
return GetMethodInfoFromExpr(pExpr.asMETHODINFO());
}
else if (pExpr.isCONSTANT())
{
CONSTVAL val = pExpr.asCONSTANT().Val;
CType underlyingType = pExpr.type;
object objval;
if (pExpr.type.IsNullType())
{
return null;
}
if (pExpr.type.isEnumType())
{
underlyingType = underlyingType.getAggregate().GetUnderlyingType();
}
switch (underlyingType.AssociatedSystemType.GetTypeCode())
{
case TypeCode.Boolean:
objval = val.boolVal;
break;
case TypeCode.SByte:
objval = val.sbyteVal;
break;
case TypeCode.Byte:
objval = val.byteVal;
break;
case TypeCode.Int16:
objval = val.shortVal;
break;
case TypeCode.UInt16:
objval = val.ushortVal;
break;
case TypeCode.Int32:
objval = val.iVal;
break;
case TypeCode.UInt32:
objval = val.uiVal;
break;
case TypeCode.Int64:
objval = val.longVal;
break;
case TypeCode.UInt64:
objval = val.ulongVal;
break;
case TypeCode.Single:
objval = val.floatVal;
break;
case TypeCode.Double:
objval = val.doubleVal;
break;
case TypeCode.Decimal:
objval = val.decVal;
break;
case TypeCode.Char:
objval = val.cVal;
break;
case TypeCode.String:
objval = val.strVal;
break;
default:
objval = val.objectVal;
break;
}
if (pExpr.type.isEnumType())
{
objval = Enum.ToObject(pExpr.type.AssociatedSystemType, objval);
}
return objval;
}
else if (pExpr.isZEROINIT())
{
if (pExpr.asZEROINIT().OptionalArgument != null)
{
return GetObject(pExpr.asZEROINIT().OptionalArgument);
}
return System.Activator.CreateInstance(pExpr.type.AssociatedSystemType);
}
Debug.Assert(false, "Invalid EXPR in GetObject");
throw Error.InternalCompilerError();
}