private AggCastResult bindExplicitConversionToEnum(AggregateType aggTypeDest)
{
Debug.Assert(_typeSrc != null);
Debug.Assert(aggTypeDest != null);
AggregateSymbol aggDest = aggTypeDest.getAggregate();
if (!aggDest.IsEnum())
{
return(AggCastResult.Failure);
}
if (_typeSrc.isPredefType(PredefinedType.PT_DECIMAL))
{
return(bindExplicitConversionFromDecimalToEnum(aggTypeDest));
}
if (_typeSrc.isNumericType() || (_typeSrc.isPredefined() && _typeSrc.getPredefType() == PredefinedType.PT_CHAR))
{
// Transform constant to constant.
if (_exprSrc.GetConst() != null)
{
ConstCastResult result = _binder.bindConstantCast(_exprSrc, _exprTypeDest, _needsExprDest, out _exprDest, true);
if (result == ConstCastResult.Success)
{
return(AggCastResult.Success);
}
if (result == ConstCastResult.CheckFailure)
{
return(AggCastResult.Abort);
}
}
if (_needsExprDest)
{
_binder.bindSimpleCast(_exprSrc, _exprTypeDest, out _exprDest);
}
return(AggCastResult.Success);
}
else if (_typeSrc.isPredefined() &&
(_typeSrc.isPredefType(PredefinedType.PT_OBJECT) || _typeSrc.isPredefType(PredefinedType.PT_VALUE) || _typeSrc.isPredefType(PredefinedType.PT_ENUM)))
{
if (_needsExprDest)
{
_binder.bindSimpleCast(_exprSrc, _exprTypeDest, out _exprDest, EXPRFLAG.EXF_UNBOX);
}
return(AggCastResult.Success);
}
return(AggCastResult.Failure);
}
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 is ExprConstant constant && _exprSrc.IsOK &&
((ptSrc == PredefinedType.PT_INT && ptDest != PredefinedType.PT_BOOL && ptDest != PredefinedType.PT_CHAR) ||
(ptSrc == PredefinedType.PT_LONG && ptDest == PredefinedType.PT_ULONG)) &&
isConstantInRange(constant, _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);
}
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);
}
private BetterType WhichConversionIsBetter(CType argType, CType p1, CType p2)
{
Debug.Assert(argType != null);
Debug.Assert(p1 != null);
Debug.Assert(p2 != null);
// 7.4.2.3 Better Conversion From Expression
//
// Given an implicit conversion C1 that converts from an expression E to a type T1
// and an implicit conversion C2 that converts from an expression E to a type T2, the
// better conversion of the two conversions is determined as follows:
//* if T1 and T2 are the same type, neither conversion is better.
//* If E has a type S and the conversion from S to T1 is better than the conversion from
// S to T2 then C1 is the better conversion.
//* If E has a type S and the conversion from S to T2 is better than the conversion from
// S to T1 then C2 is the better conversion.
//* If E is a lambda expression or anonymous method for which an inferred return type X
// exists and T1 is a delegate type and T2 is a delegate type and T1 and T2 have identical
// parameter lists:
// * If T1 is a delegate of return type Y1 and T2 is a delegate of return type Y2 and the
// conversion from X to Y1 is better than the conversion from X to Y2, then C1 is the
// better return type.
// * If T1 is a delegate of return type Y1 and T2 is a delegate of return type Y2 and the
// conversion from X to Y2 is better than the conversion from X to Y1, then C2 is the
// better return type.
if (p1 == p2)
{
return(BetterType.Same);
}
// 7.4.2.4 Better conversion from type
//
// Given a conversion C1 that converts from a type S to a type T1 and a conversion C2
// that converts from a type S to a type T2, the better conversion of the two conversions
// is determined as follows:
//* If T1 and T2 are the same type, neither conversion is better
//* If S is T1, C1 is the better conversion.
//* If S is T2, C2 is the better conversion.
//* If an implicit conversion from T1 to T2 exists and no implicit conversion from T2 to
// T1 exists, C1 is the better conversion.
//* If an implicit conversion from T2 to T1 exists and no implicit conversion from T1 to
// T2 exists, C2 is the better conversion.
//
// [Otherwise, see table above for better integral type conversions.]
if (argType == p1)
{
return(BetterType.Left);
}
if (argType == p2)
{
return(BetterType.Right);
}
bool a2b = canConvert(p1, p2);
bool b2a = canConvert(p2, p1);
if (a2b != b2a)
{
return(a2b ? BetterType.Left : BetterType.Right);
}
if (p1.isPredefined() && p2.isPredefined())
{
PredefinedType pt1 = p1.getPredefType();
if (pt1 <= PredefinedType.PT_OBJECT)
{
PredefinedType pt2 = p2.getPredefType();
if (pt2 <= PredefinedType.PT_OBJECT)
{
return((BetterType)s_betterConversionTable[(int)pt1][(int)pt2]);
}
}
}
return(BetterType.Neither);
}
private BetterType WhichConversionIsBetter(CType argType,
CType p1, CType p2)
{
// 7.4.2.4 Better conversion from type
//
// Given a conversion C1 that converts from a type S to a type T1 and a conversion C2
// that converts from a type S to a type T2, the better conversion of the two conversions
// is determined as follows:
//* If T1 and T2 are the same type, neither conversion is better
//* If S is T1, C1 is the better conversion.
//* If S is T2, C2 is the better conversion.
//* If an implicit conversion from T1 to T2 exists and no implicit conversion from T2 to
// T1 exists, C1 is the better conversion.
//* If an implicit conversion from T2 to T1 exists and no implicit conversion from T1 to
// T2 exists, C2 is the better conversion.
//
// [Otherwise, see table above for better integral type conversions.]
if (p1 == p2)
{
return(BetterType.Same);
}
if (argType == p1)
{
return(BetterType.Left);
}
if (argType == p2)
{
return(BetterType.Right);
}
bool a2b = canConvert(p1, p2);
bool b2a = canConvert(p2, p1);
if (a2b && !b2a)
{
return(BetterType.Left);
}
if (b2a && !a2b)
{
return(BetterType.Right);
}
Debug.Assert(b2a == a2b);
if (p1.isPredefined() && p2.isPredefined() &&
p1.getPredefType() <= PredefinedType.PT_OBJECT && p2.getPredefType() <= PredefinedType.PT_OBJECT)
{
int c = s_betterConversionTable[(int)p1.getPredefType()][(int)p2.getPredefType()];
if (c == 1)
{
return(BetterType.Left);
}
else if (c == 2)
{
return(BetterType.Right);
}
}
return(BetterType.Neither);
}
public BetterType WhichConversionIsBetter(CType argType,
CType p1, CType p2)
{
// 7.4.2.4 Better conversion from type
//
// Given a conversion C1 that converts from a type S to a type T1 and a conversion C2
// that converts from a type S to a type T2, the better conversion of the two conversions
// is determined as follows:
//* If T1 and T2 are the same type, neither conversion is better
//* If S is T1, C1 is the better conversion.
//* If S is T2, C2 is the better conversion.
//* If an implicit conversion from T1 to T2 exists and no implicit conversion from T2 to
// T1 exists, C1 is the better conversion.
//* If an implicit conversion from T2 to T1 exists and no implicit conversion from T1 to
// T2 exists, C2 is the better conversion.
//
// [Otherwise, see table above for better integral type conversions.]
if (p1 == p2)
{
return BetterType.Same;
}
if (argType == p1)
{
return BetterType.Left;
}
if (argType == p2)
{
return BetterType.Right;
}
bool a2b = canConvert(p1, p2);
bool b2a = canConvert(p2, p1);
if (a2b && !b2a)
{
return BetterType.Left;
}
if (b2a && !a2b)
{
return BetterType.Right;
}
Debug.Assert(b2a == a2b);
if (p1.isPredefined() && p2.isPredefined() &&
p1.getPredefType() <= PredefinedType.PT_OBJECT && p2.getPredefType() <= PredefinedType.PT_OBJECT)
{
int c = s_betterConversionTable[(int)p1.getPredefType()][(int)p2.getPredefType()];
if (c == 1)
{
return BetterType.Left;
}
else if (c == 2)
{
return BetterType.Right;
}
}
return BetterType.Neither;
}