2 // conversion.cs: various routines for implementing conversions.
5 // Miguel de Icaza (miguel@ximian.com)
6 // Ravi Pratap (ravi@ximian.com)
7 // Marek Safar (marek.safar@gmail.com)
9 // Copyright 2001, 2002, 2003 Ximian, Inc.
10 // Copyright 2003-2008 Novell, Inc.
11 // Copyright 2011 Xamarin Inc (http://www.xamarin.com)
15 using System.Collections.Generic;
18 using IKVM.Reflection.Emit;
20 using System.Reflection.Emit;
23 namespace Mono.CSharp {
26 // A container class for all the conversion operations
31 public enum UserConversionRestriction
36 NullableSourceOnly = 1 << 2
40 // From a one-dimensional array-type S[] to System.Collections.IList<T> and base
41 // interfaces of this interface, provided there is an implicit reference conversion
44 static bool ArrayToIList (ArrayContainer array, TypeSpec list, bool isExplicit)
46 if (array.Rank != 1 || !list.IsArrayGenericInterface)
49 var arg_type = list.TypeArguments[0];
50 if (array.Element == arg_type)
54 // Reject conversion from T[] to IList<U> even if T has U dependency
56 if (arg_type.IsGenericParameter)
60 return ExplicitReferenceConversionExists (array.Element, arg_type);
62 return ImplicitReferenceConversionExists (array.Element, arg_type);
65 static bool IList_To_Array(TypeSpec list, ArrayContainer array)
67 if (array.Rank != 1 || !list.IsArrayGenericInterface)
70 var arg_type = list.TypeArguments[0];
71 if (array.Element == arg_type)
74 return ImplicitReferenceConversionExists (array.Element, arg_type) || ExplicitReferenceConversionExists (array.Element, arg_type);
77 public static Expression ImplicitTypeParameterConversion (Expression expr, TypeParameterSpec expr_type, TypeSpec target_type)
80 // From T to a type parameter U, provided T depends on U
82 if (target_type.IsGenericParameter) {
83 if (expr_type.TypeArguments != null && expr_type.HasDependencyOn (target_type)) {
85 return EmptyExpression.Null;
87 if (expr_type.IsReferenceType && !((TypeParameterSpec) target_type).IsReferenceType)
88 return new BoxedCast (expr, target_type);
90 return new ClassCast (expr, target_type);
97 // LAMESPEC: From T to dynamic type because it's like T to object
99 if (target_type.BuiltinType == BuiltinTypeSpec.Type.Dynamic) {
101 return EmptyExpression.Null;
103 if (expr_type.IsReferenceType)
104 return new ClassCast (expr, target_type);
106 return new BoxedCast (expr, target_type);
110 // From T to its effective base class C
111 // From T to any base class of C (it cannot contain dynamic or be of dynamic type)
112 // From T to any interface implemented by C
114 var base_type = expr_type.GetEffectiveBase ();
115 if (base_type == target_type || TypeSpec.IsBaseClass (base_type, target_type, false) || base_type.ImplementsInterface (target_type, true)) {
117 return EmptyExpression.Null;
119 if (expr_type.IsReferenceType)
120 return new ClassCast (expr, target_type);
122 return new BoxedCast (expr, target_type);
125 if (target_type.IsInterface && expr_type.IsConvertibleToInterface (target_type)) {
127 return EmptyExpression.Null;
129 if (expr_type.IsReferenceType)
130 return new ClassCast (expr, target_type);
132 return new BoxedCast (expr, target_type);
138 static Expression ExplicitTypeParameterConversionFromT (Expression source, TypeSpec source_type, TypeSpec target_type)
140 var target_tp = target_type as TypeParameterSpec;
141 if (target_tp != null) {
143 // From a type parameter U to T, provided T depends on U
145 if (target_tp.TypeArguments != null && target_tp.HasDependencyOn (source_type)) {
146 return source == null ? EmptyExpression.Null : new ClassCast (source, target_type);
151 // From T to any interface-type I provided there is not already an implicit conversion from T to I
153 if (target_type.IsInterface)
154 return source == null ? EmptyExpression.Null : new ClassCast (source, target_type, true);
159 static Expression ExplicitTypeParameterConversionToT (Expression source, TypeSpec source_type, TypeParameterSpec target_type)
162 // From the effective base class C of T to T and from any base class of C to T
164 var effective = target_type.GetEffectiveBase ();
165 if (TypeSpecComparer.IsEqual (effective, source_type) || TypeSpec.IsBaseClass (effective, source_type, false))
166 return source == null ? EmptyExpression.Null : new ClassCast (source, target_type);
171 public static Expression ImplicitReferenceConversion (Expression expr, TypeSpec target_type, bool explicit_cast)
173 TypeSpec expr_type = expr.Type;
175 if (expr_type.Kind == MemberKind.TypeParameter)
176 return ImplicitTypeParameterConversion (expr, (TypeParameterSpec) expr.Type, target_type);
179 // from the null type to any reference-type.
181 NullLiteral nl = expr as NullLiteral;
183 return nl.ConvertImplicitly (target_type);
186 if (ImplicitReferenceConversionExists (expr_type, target_type)) {
188 // Avoid wrapping implicitly convertible reference type
193 return EmptyCast.Create (expr, target_type);
200 // Implicit reference conversions
202 public static bool ImplicitReferenceConversionExists (TypeSpec expr_type, TypeSpec target_type)
204 return ImplicitReferenceConversionExists (expr_type, target_type, true);
207 public static bool ImplicitReferenceConversionExists (TypeSpec expr_type, TypeSpec target_type, bool refOnlyTypeParameter)
209 // It's here only to speed things up
210 if (target_type.IsStruct)
213 switch (expr_type.Kind) {
214 case MemberKind.TypeParameter:
215 return ImplicitTypeParameterConversion (null, (TypeParameterSpec) expr_type, target_type) != null &&
216 (!refOnlyTypeParameter || TypeSpec.IsReferenceType (expr_type));
218 case MemberKind.Class:
220 // From any class-type to dynamic (+object to speed up common path)
222 if (target_type.BuiltinType == BuiltinTypeSpec.Type.Object || target_type.BuiltinType == BuiltinTypeSpec.Type.Dynamic)
225 if (target_type.IsClass) {
227 // Identity conversion, including dynamic erasure
229 if (TypeSpecComparer.IsEqual (expr_type, target_type))
233 // From any class-type S to any class-type T, provided S is derived from T
235 return TypeSpec.IsBaseClass (expr_type, target_type, true);
239 // From any class-type S to any interface-type T, provided S implements T
241 if (target_type.IsInterface)
242 return expr_type.ImplementsInterface (target_type, true);
246 case MemberKind.ArrayType:
248 // Identity array conversion
250 if (expr_type == target_type)
254 // From any array-type to System.Array
256 switch (target_type.BuiltinType) {
257 case BuiltinTypeSpec.Type.Array:
258 case BuiltinTypeSpec.Type.Object:
259 case BuiltinTypeSpec.Type.Dynamic:
263 var expr_type_array = (ArrayContainer) expr_type;
264 var target_type_array = target_type as ArrayContainer;
267 // From an array-type S to an array-type of type T
269 if (target_type_array != null && expr_type_array.Rank == target_type_array.Rank) {
272 // Both SE and TE are reference-types. TE check is defered
273 // to ImplicitReferenceConversionExists
275 TypeSpec expr_element_type = expr_type_array.Element;
276 if (!TypeSpec.IsReferenceType (expr_element_type))
280 // An implicit reference conversion exists from SE to TE
282 return ImplicitReferenceConversionExists (expr_element_type, target_type_array.Element);
286 // From any array-type to the interfaces it implements
288 if (target_type.IsInterface) {
289 if (expr_type.ImplementsInterface (target_type, false))
292 // from an array-type of type T to IList<T>
293 if (ArrayToIList (expr_type_array, target_type, false))
299 case MemberKind.Delegate:
301 // From any delegate-type to System.Delegate (and its base types)
303 switch (target_type.BuiltinType) {
304 case BuiltinTypeSpec.Type.Delegate:
305 case BuiltinTypeSpec.Type.MulticastDelegate:
306 case BuiltinTypeSpec.Type.Object:
307 case BuiltinTypeSpec.Type.Dynamic:
312 // Identity conversion, including dynamic erasure
314 if (TypeSpecComparer.IsEqual (expr_type, target_type))
318 // From any delegate-type to the interfaces it implements
319 // From any reference-type to an delegate type if is variance-convertible
321 return expr_type.ImplementsInterface (target_type, false) || TypeSpecComparer.Variant.IsEqual (expr_type, target_type);
323 case MemberKind.Interface:
325 // Identity conversion, including dynamic erasure
327 if (TypeSpecComparer.IsEqual (expr_type, target_type))
331 // From any interface type S to interface-type T
332 // From any reference-type to an interface if is variance-convertible
334 if (target_type.IsInterface)
335 return TypeSpecComparer.Variant.IsEqual (expr_type, target_type) || expr_type.ImplementsInterface (target_type, true);
337 return target_type.BuiltinType == BuiltinTypeSpec.Type.Object || target_type.BuiltinType == BuiltinTypeSpec.Type.Dynamic;
339 case MemberKind.InternalCompilerType:
341 // from the null literal to any reference-type.
343 if (expr_type == InternalType.NullLiteral) {
344 // Exlude internal compiler types
345 if (target_type.Kind == MemberKind.InternalCompilerType)
346 return target_type.BuiltinType == BuiltinTypeSpec.Type.Dynamic;
348 return TypeSpec.IsReferenceType (target_type) || target_type.Kind == MemberKind.PointerType;
352 // Implicit dynamic conversion
354 if (expr_type.BuiltinType == BuiltinTypeSpec.Type.Dynamic) {
355 switch (target_type.Kind) {
356 case MemberKind.ArrayType:
357 case MemberKind.Class:
358 case MemberKind.Delegate:
359 case MemberKind.Interface:
360 case MemberKind.TypeParameter:
364 // dynamic to __arglist
365 if (target_type == InternalType.Arglist)
377 public static Expression ImplicitBoxingConversion (Expression expr, TypeSpec expr_type, TypeSpec target_type)
379 switch (target_type.BuiltinType) {
381 // From any non-nullable-value-type to the type object and dynamic
383 case BuiltinTypeSpec.Type.Object:
384 case BuiltinTypeSpec.Type.Dynamic:
386 // From any non-nullable-value-type to the type System.ValueType
388 case BuiltinTypeSpec.Type.ValueType:
390 // No ned to check for nullable type as underlying type is always convertible
392 if (!TypeSpec.IsValueType (expr_type))
395 return expr == null ? EmptyExpression.Null : new BoxedCast (expr, target_type);
397 case BuiltinTypeSpec.Type.Enum:
399 // From any enum-type to the type System.Enum.
401 if (expr_type.IsEnum)
402 return expr == null ? EmptyExpression.Null : new BoxedCast (expr, target_type);
408 // From a nullable-type to a reference type, if a boxing conversion exists from
409 // the underlying type to the reference type
411 if (expr_type.IsNullableType) {
412 if (!TypeSpec.IsReferenceType (target_type))
415 var res = ImplicitBoxingConversion (expr, Nullable.NullableInfo.GetUnderlyingType (expr_type), target_type);
417 // "cast" underlying type to target type to emit correct InvalidCastException when
418 // underlying hierarchy changes without recompilation
419 if (res != null && expr != null)
420 res = new UnboxCast (res, target_type);
426 // A value type has a boxing conversion to an interface type I if it has a boxing conversion
427 // to an interface or delegate type I0 and I0 is variance-convertible to I
429 if (target_type.IsInterface && TypeSpec.IsValueType (expr_type) && expr_type.ImplementsInterface (target_type, true)) {
430 return expr == null ? EmptyExpression.Null : new BoxedCast (expr, target_type);
436 public static Expression ImplicitNulableConversion (ResolveContext ec, Expression expr, TypeSpec target_type)
438 TypeSpec expr_type = expr.Type;
441 // From null to any nullable type
443 if (expr_type == InternalType.NullLiteral)
444 return ec == null ? EmptyExpression.Null : Nullable.LiftedNull.Create (target_type, expr.Location);
447 TypeSpec t_el = Nullable.NullableInfo.GetUnderlyingType (target_type);
450 if (expr_type.IsNullableType)
451 expr_type = Nullable.NullableInfo.GetUnderlyingType (expr_type);
454 // Predefined implicit identity or implicit numeric conversion
455 // has to exist between underlying type S and underlying type T
458 // conversion exists only mode
460 if (TypeSpecComparer.IsEqual (expr_type, t_el))
461 return EmptyExpression.Null;
463 if (expr is Constant)
464 return ((Constant) expr).ConvertImplicitly (t_el);
466 return ImplicitNumericConversion (null, expr_type, t_el);
470 if (expr_type != expr.Type)
471 unwrap = Nullable.Unwrap.Create (expr);
475 Expression conv = unwrap;
476 if (!TypeSpecComparer.IsEqual (expr_type, t_el)) {
477 if (conv is Constant)
478 conv = ((Constant)conv).ConvertImplicitly (t_el);
480 conv = ImplicitNumericConversion (conv, expr_type, t_el);
486 if (expr_type != expr.Type)
487 return new Nullable.LiftedConversion (conv, unwrap, target_type).Resolve (ec);
489 return Nullable.Wrap.Create (conv, target_type);
493 /// Implicit Numeric Conversions.
495 /// expr is the expression to convert, returns a new expression of type
496 /// target_type or null if an implicit conversion is not possible.
498 public static Expression ImplicitNumericConversion (Expression expr, TypeSpec target_type)
500 return ImplicitNumericConversion (expr, expr.Type, target_type);
503 public static bool ImplicitNumericConversionExists (TypeSpec expr_type, TypeSpec target_type)
505 return ImplicitNumericConversion (null, expr_type, target_type) != null;
508 static Expression ImplicitNumericConversion (Expression expr, TypeSpec expr_type, TypeSpec target_type)
510 switch (expr_type.BuiltinType) {
511 case BuiltinTypeSpec.Type.SByte:
513 // From sbyte to short, int, long, float, double, decimal
515 switch (target_type.BuiltinType) {
516 case BuiltinTypeSpec.Type.Int:
517 return expr == null ? EmptyExpression.Null : new OpcodeCast (expr, target_type, OpCodes.Conv_I4);
518 case BuiltinTypeSpec.Type.Long:
519 return expr == null ? EmptyExpression.Null : new OpcodeCast (expr, target_type, OpCodes.Conv_I8);
520 case BuiltinTypeSpec.Type.Double:
521 return expr == null ? EmptyExpression.Null : new OpcodeCast (expr, target_type, OpCodes.Conv_R8);
522 case BuiltinTypeSpec.Type.Float:
523 return expr == null ? EmptyExpression.Null : new OpcodeCast (expr, target_type, OpCodes.Conv_R4);
524 case BuiltinTypeSpec.Type.Short:
525 return expr == null ? EmptyExpression.Null : new OpcodeCast (expr, target_type, OpCodes.Conv_I2);
526 case BuiltinTypeSpec.Type.Decimal:
527 return expr == null ? EmptyExpression.Null : new OperatorCast (expr, target_type);
532 case BuiltinTypeSpec.Type.Byte:
534 // From byte to short, ushort, int, uint, long, ulong, float, double, decimal
536 switch (target_type.BuiltinType) {
537 case BuiltinTypeSpec.Type.Int:
538 case BuiltinTypeSpec.Type.UInt:
539 case BuiltinTypeSpec.Type.Short:
540 case BuiltinTypeSpec.Type.UShort:
541 return expr == null ? EmptyExpression.Null : EmptyCast.Create (expr, target_type);
542 case BuiltinTypeSpec.Type.ULong:
543 return expr == null ? EmptyExpression.Null : new OpcodeCast (expr, target_type, OpCodes.Conv_U8);
544 case BuiltinTypeSpec.Type.Long:
545 return expr == null ? EmptyExpression.Null : new OpcodeCast (expr, target_type, OpCodes.Conv_I8);
546 case BuiltinTypeSpec.Type.Float:
547 return expr == null ? EmptyExpression.Null : new OpcodeCast (expr, target_type, OpCodes.Conv_R4);
548 case BuiltinTypeSpec.Type.Double:
549 return expr == null ? EmptyExpression.Null : new OpcodeCast (expr, target_type, OpCodes.Conv_R8);
550 case BuiltinTypeSpec.Type.Decimal:
551 return expr == null ? EmptyExpression.Null : new OperatorCast (expr, target_type);
554 case BuiltinTypeSpec.Type.Short:
556 // From short to int, long, float, double, decimal
558 switch (target_type.BuiltinType) {
559 case BuiltinTypeSpec.Type.Int:
560 return expr == null ? EmptyExpression.Null : EmptyCast.Create (expr, target_type);
561 case BuiltinTypeSpec.Type.Long:
562 return expr == null ? EmptyExpression.Null : new OpcodeCast (expr, target_type, OpCodes.Conv_I8);
563 case BuiltinTypeSpec.Type.Double:
564 return expr == null ? EmptyExpression.Null : new OpcodeCast (expr, target_type, OpCodes.Conv_R8);
565 case BuiltinTypeSpec.Type.Float:
566 return expr == null ? EmptyExpression.Null : new OpcodeCast (expr, target_type, OpCodes.Conv_R4);
567 case BuiltinTypeSpec.Type.Decimal:
568 return expr == null ? EmptyExpression.Null : new OperatorCast (expr, target_type);
571 case BuiltinTypeSpec.Type.UShort:
573 // From ushort to int, uint, long, ulong, float, double, decimal
575 switch (target_type.BuiltinType) {
576 case BuiltinTypeSpec.Type.Int:
577 case BuiltinTypeSpec.Type.UInt:
578 return expr == null ? EmptyExpression.Null : EmptyCast.Create (expr, target_type);
579 case BuiltinTypeSpec.Type.ULong:
580 return expr == null ? EmptyExpression.Null : new OpcodeCast (expr, target_type, OpCodes.Conv_U8);
581 case BuiltinTypeSpec.Type.Long:
582 return expr == null ? EmptyExpression.Null : new OpcodeCast (expr, target_type, OpCodes.Conv_I8);
583 case BuiltinTypeSpec.Type.Double:
584 return expr == null ? EmptyExpression.Null : new OpcodeCast (expr, target_type, OpCodes.Conv_R8);
585 case BuiltinTypeSpec.Type.Float:
586 return expr == null ? EmptyExpression.Null : new OpcodeCast (expr, target_type, OpCodes.Conv_R4);
587 case BuiltinTypeSpec.Type.Decimal:
588 return expr == null ? EmptyExpression.Null : new OperatorCast (expr, target_type);
591 case BuiltinTypeSpec.Type.Int:
593 // From int to long, float, double, decimal
595 switch (target_type.BuiltinType) {
596 case BuiltinTypeSpec.Type.Long:
597 return expr == null ? EmptyExpression.Null : new OpcodeCast (expr, target_type, OpCodes.Conv_I8);
598 case BuiltinTypeSpec.Type.Double:
599 return expr == null ? EmptyExpression.Null : new OpcodeCast (expr, target_type, OpCodes.Conv_R8);
600 case BuiltinTypeSpec.Type.Float:
601 return expr == null ? EmptyExpression.Null : new OpcodeCast (expr, target_type, OpCodes.Conv_R4);
602 case BuiltinTypeSpec.Type.Decimal:
603 return expr == null ? EmptyExpression.Null : new OperatorCast (expr, target_type);
606 case BuiltinTypeSpec.Type.UInt:
608 // From uint to long, ulong, float, double, decimal
610 switch (target_type.BuiltinType) {
611 case BuiltinTypeSpec.Type.Long:
612 return expr == null ? EmptyExpression.Null : new OpcodeCast (expr, target_type, OpCodes.Conv_U8);
613 case BuiltinTypeSpec.Type.ULong:
614 return expr == null ? EmptyExpression.Null : new OpcodeCast (expr, target_type, OpCodes.Conv_U8);
615 case BuiltinTypeSpec.Type.Double:
616 return expr == null ? EmptyExpression.Null : new OpcodeCastDuplex (expr, target_type, OpCodes.Conv_R_Un, OpCodes.Conv_R8);
617 case BuiltinTypeSpec.Type.Float:
618 return expr == null ? EmptyExpression.Null : new OpcodeCastDuplex (expr, target_type, OpCodes.Conv_R_Un, OpCodes.Conv_R4);
619 case BuiltinTypeSpec.Type.Decimal:
620 return expr == null ? EmptyExpression.Null : new OperatorCast (expr, target_type);
623 case BuiltinTypeSpec.Type.Long:
625 // From long to float, double, decimal
627 switch (target_type.BuiltinType) {
628 case BuiltinTypeSpec.Type.Double:
629 return expr == null ? EmptyExpression.Null : new OpcodeCast (expr, target_type, OpCodes.Conv_R8);
630 case BuiltinTypeSpec.Type.Float:
631 return expr == null ? EmptyExpression.Null : new OpcodeCast (expr, target_type, OpCodes.Conv_R4);
632 case BuiltinTypeSpec.Type.Decimal:
633 return expr == null ? EmptyExpression.Null : new OperatorCast (expr, target_type);
636 case BuiltinTypeSpec.Type.ULong:
638 // From ulong to float, double, decimal
640 switch (target_type.BuiltinType) {
641 case BuiltinTypeSpec.Type.Double:
642 return expr == null ? EmptyExpression.Null : new OpcodeCastDuplex (expr, target_type, OpCodes.Conv_R_Un, OpCodes.Conv_R8);
643 case BuiltinTypeSpec.Type.Float:
644 return expr == null ? EmptyExpression.Null : new OpcodeCastDuplex (expr, target_type, OpCodes.Conv_R_Un, OpCodes.Conv_R4);
645 case BuiltinTypeSpec.Type.Decimal:
646 return expr == null ? EmptyExpression.Null : new OperatorCast (expr, target_type);
649 case BuiltinTypeSpec.Type.Char:
651 // From char to ushort, int, uint, long, ulong, float, double, decimal
653 switch (target_type.BuiltinType) {
654 case BuiltinTypeSpec.Type.UShort:
655 case BuiltinTypeSpec.Type.Int:
656 case BuiltinTypeSpec.Type.UInt:
657 return expr == null ? EmptyExpression.Null : EmptyCast.Create (expr, target_type);
658 case BuiltinTypeSpec.Type.ULong:
659 return expr == null ? EmptyExpression.Null : new OpcodeCast (expr, target_type, OpCodes.Conv_U8);
660 case BuiltinTypeSpec.Type.Long:
661 return expr == null ? EmptyExpression.Null : new OpcodeCast (expr, target_type, OpCodes.Conv_I8);
662 case BuiltinTypeSpec.Type.Float:
663 return expr == null ? EmptyExpression.Null : new OpcodeCast (expr, target_type, OpCodes.Conv_R4);
664 case BuiltinTypeSpec.Type.Double:
665 return expr == null ? EmptyExpression.Null : new OpcodeCast (expr, target_type, OpCodes.Conv_R8);
666 case BuiltinTypeSpec.Type.Decimal:
667 return expr == null ? EmptyExpression.Null : new OperatorCast (expr, target_type);
670 case BuiltinTypeSpec.Type.Float:
674 if (target_type.BuiltinType == BuiltinTypeSpec.Type.Double)
675 return expr == null ? EmptyExpression.Null : new OpcodeCast (expr, target_type, OpCodes.Conv_R8);
682 static Expression ImplicitTupleLiteralConversion (ResolveContext rc, Expression source, TypeSpec targetType, Location loc)
684 var targetTypeArgument = targetType.TypeArguments;
685 if (source.Type.Arity != targetTypeArgument.Length)
688 var namedTarget = targetType as NamedTupleSpec;
689 var tupleLiteral = source as TupleLiteral;
692 if (tupleLiteral == null && !ExpressionAnalyzer.IsInexpensiveLoad (source)) {
693 var expr_variable = LocalVariable.CreateCompilerGenerated (source.Type, rc.CurrentBlock, loc);
694 source = new CompilerAssign (expr_variable.CreateReferenceExpression (rc, loc), source, loc);
695 instance = expr_variable.CreateReferenceExpression (rc, loc);
700 var converted = new List<Expression> (targetType.Arity);
701 for (int i = 0; i < targetType.Arity; ++i) {
702 Expression elementSrc;
703 if (tupleLiteral != null) {
704 elementSrc = tupleLiteral.Elements [i].Expr;
706 if (namedTarget != null) {
707 var elementSrcName = tupleLiteral.Elements [i].Name;
708 if (elementSrcName != null && elementSrcName != namedTarget.Elements [i]) {
709 rc.Report.Warning (8123, 1, loc,
710 "The tuple element name `{0}' is ignored because a different name or no name is specified by the target type `{1}'",
711 elementSrcName, namedTarget.GetSignatureForErrorWithNames ());
715 elementSrc = new MemberAccess (instance, NamedTupleSpec.GetElementPropertyName (i)).Resolve (rc);
718 var res = ImplicitConversionStandard (rc, elementSrc, targetTypeArgument [i], loc);
725 return new TupleLiteralConversion (source, targetType, converted, loc);
728 static bool ImplicitTupleLiteralConversionExists (Expression source, TypeSpec targetType)
730 if (source.Type.Arity != targetType.Arity)
733 var srcTypeArgument = source.Type.TypeArguments;
734 var targetTypeArgument = targetType.TypeArguments;
736 var tupleLiteralElements = (source as TupleLiteral)?.Elements;
738 for (int i = 0; i < targetType.Arity; ++i) {
739 if (tupleLiteralElements != null) {
740 if (!ImplicitStandardConversionExists (tupleLiteralElements[i].Expr, targetTypeArgument [i])) {
744 if (!ImplicitStandardConversionExists (new EmptyExpression (srcTypeArgument [i]), targetTypeArgument [i])) {
755 // Full version of implicit conversion
757 public static bool ImplicitConversionExists (ResolveContext ec, Expression expr, TypeSpec target_type)
759 if (ImplicitStandardConversionExists (ec, expr, target_type))
762 if (expr.Type == InternalType.AnonymousMethod) {
763 if (!target_type.IsDelegate && !target_type.IsExpressionTreeType)
766 AnonymousMethodExpression ame = (AnonymousMethodExpression) expr;
767 return ame.ImplicitStandardConversionExists (ec, target_type);
770 // Conversion from __arglist to System.ArgIterator
771 if (expr.Type == InternalType.Arglist)
772 return target_type == ec.Module.PredefinedTypes.ArgIterator.TypeSpec;
774 return UserDefinedConversion (ec, expr, target_type,
775 UserConversionRestriction.ImplicitOnly | UserConversionRestriction.ProbingOnly, Location.Null) != null;
778 public static bool ImplicitStandardConversionExists (ResolveContext rc, Expression expr, TypeSpec target_type)
780 if (expr.eclass == ExprClass.MethodGroup) {
781 if (target_type.IsDelegate && rc.Module.Compiler.Settings.Version != LanguageVersion.ISO_1) {
782 MethodGroupExpr mg = expr as MethodGroupExpr;
784 return DelegateCreation.ImplicitStandardConversionExists (rc, mg, target_type);
790 var interpolated_string = expr as InterpolatedString;
791 if (interpolated_string != null) {
792 if (target_type == rc.Module.PredefinedTypes.IFormattable.TypeSpec || target_type == rc.Module.PredefinedTypes.FormattableString.TypeSpec)
796 return ImplicitStandardConversionExists (expr, target_type);
800 // Implicit standard conversion (only core conversions are used here)
802 public static bool ImplicitStandardConversionExists (Expression expr, TypeSpec target_type)
805 // Identity conversions
806 // Implicit numeric conversions
807 // Implicit nullable conversions
808 // Implicit reference conversions
809 // Boxing conversions
810 // Implicit constant expression conversions
811 // Implicit conversions involving type parameters
814 TypeSpec expr_type = expr.Type;
816 if (expr_type == target_type)
819 if (expr_type == InternalType.ThrowExpr)
820 return target_type.Kind != MemberKind.InternalCompilerType;
822 if (target_type.IsNullableType)
823 return ImplicitNulableConversion (null, expr, target_type) != null;
825 if (ImplicitNumericConversion (null, expr_type, target_type) != null)
828 if (ImplicitReferenceConversionExists (expr_type, target_type, false))
831 if (ImplicitBoxingConversion (null, expr_type, target_type) != null)
834 if (expr_type.IsTupleType && target_type.IsTupleType)
835 return ImplicitTupleLiteralConversionExists (expr, target_type);
838 // Implicit Constant Expression Conversions
840 if (expr is IntConstant){
841 int value = ((IntConstant) expr).Value;
842 switch (target_type.BuiltinType) {
843 case BuiltinTypeSpec.Type.SByte:
844 if (value >= SByte.MinValue && value <= SByte.MaxValue)
847 case BuiltinTypeSpec.Type.Byte:
848 if (value >= 0 && value <= Byte.MaxValue)
851 case BuiltinTypeSpec.Type.Short:
852 if (value >= Int16.MinValue && value <= Int16.MaxValue)
855 case BuiltinTypeSpec.Type.UShort:
856 if (value >= UInt16.MinValue && value <= UInt16.MaxValue)
859 case BuiltinTypeSpec.Type.UInt:
863 case BuiltinTypeSpec.Type.ULong:
865 // we can optimize this case: a positive int32
866 // always fits on a uint64. But we need an opcode
876 if (expr is LongConstant && target_type.BuiltinType == BuiltinTypeSpec.Type.ULong){
878 // Try the implicit constant expression conversion
879 // from long to ulong, instead of a nice routine,
882 long v = ((LongConstant) expr).Value;
887 if (expr is IntegralConstant && target_type.IsEnum) {
888 var i = (IntegralConstant) expr;
890 // LAMESPEC: csc allows any constant like 0 values to be converted, including const float f = 0.0
892 // An implicit enumeration conversion permits the decimal-integer-literal 0
893 // to be converted to any enum-type and to any nullable-type whose underlying
894 // type is an enum-type
896 return i.IsZeroInteger;
900 // Implicit dynamic conversion for remaining value types. It should probably
903 if (expr_type.BuiltinType == BuiltinTypeSpec.Type.Dynamic) {
904 switch (target_type.Kind) {
905 case MemberKind.Struct:
906 case MemberKind.Enum:
914 // In an unsafe context implicit conversions is extended to include
916 // From any pointer-type to the type void*
917 // From the null literal to any pointer-type.
919 // LAMESPEC: The specification claims this conversion is allowed in implicit conversion but
920 // in reality implicit standard conversion uses it
922 if (target_type.IsPointer && expr.Type.IsPointer && ((PointerContainer) target_type).Element.Kind == MemberKind.Void)
926 // Struct identity conversion, including dynamic erasure
928 if (expr_type.IsStruct && TypeSpecComparer.IsEqual (expr_type, target_type))
935 /// Finds "most encompassed type" according to the spec (13.4.2)
936 /// amongst the methods in the MethodGroupExpr
938 public static TypeSpec FindMostEncompassedType (IList<TypeSpec> types)
940 TypeSpec best = null;
941 EmptyExpression expr;
943 foreach (TypeSpec t in types) {
949 expr = new EmptyExpression (t);
950 if (ImplicitStandardConversionExists (expr, best))
954 expr = new EmptyExpression (best);
955 foreach (TypeSpec t in types) {
958 if (!ImplicitStandardConversionExists (expr, t)) {
968 // Finds the most encompassing type (type into which all other
969 // types can convert to) amongst the types in the given set
971 static TypeSpec FindMostEncompassingType (IList<TypeSpec> types)
973 if (types.Count == 0)
976 if (types.Count == 1)
979 TypeSpec best = null;
980 for (int i = 0; i < types.Count; ++i) {
982 for (; ii < types.Count; ++ii) {
986 var expr = new EmptyExpression (types[ii]);
987 if (!ImplicitStandardConversionExists (expr, types [i])) {
1001 // Indicates multiple best types
1002 return InternalType.FakeInternalType;
1009 // Finds the most specific source Sx according to the rules of the spec (13.4.4)
1010 // by making use of FindMostEncomp* methods. Applies the correct rules separately
1011 // for explicit and implicit conversion operators.
1013 static TypeSpec FindMostSpecificSource (ResolveContext rc, List<MethodSpec> list, TypeSpec sourceType, Expression source, bool apply_explicit_conv_rules)
1015 TypeSpec[] src_types_set = null;
1018 // Try exact match first, if any operator converts from S then Sx = S
1020 for (int i = 0; i < list.Count; ++i) {
1021 TypeSpec param_type = list [i].Parameters.Types [0];
1023 if (param_type == sourceType)
1026 if (src_types_set == null)
1027 src_types_set = new TypeSpec [list.Count];
1029 src_types_set [i] = param_type;
1033 // Explicit Conv rules
1035 if (apply_explicit_conv_rules) {
1036 var candidate_set = new List<TypeSpec> ();
1038 foreach (TypeSpec param_type in src_types_set){
1039 if (ImplicitStandardConversionExists (rc, source, param_type))
1040 candidate_set.Add (param_type);
1043 if (candidate_set.Count != 0) {
1044 if (source.eclass == ExprClass.MethodGroup)
1045 return InternalType.FakeInternalType;
1047 return FindMostEncompassedType (candidate_set);
1054 if (apply_explicit_conv_rules)
1055 return FindMostEncompassingType (src_types_set);
1057 return FindMostEncompassedType (src_types_set);
1061 /// Finds the most specific target Tx according to section 13.4.4
1063 static public TypeSpec FindMostSpecificTarget (IList<MethodSpec> list,
1064 TypeSpec target, bool apply_explicit_conv_rules)
1066 List<TypeSpec> tgt_types_set = null;
1069 // If any operator converts to T then Tx = T
1071 foreach (var mi in list){
1072 TypeSpec ret_type = mi.ReturnType;
1073 if (ret_type == target)
1076 if (tgt_types_set == null) {
1077 tgt_types_set = new List<TypeSpec> (list.Count);
1078 } else if (tgt_types_set.Contains (ret_type)) {
1082 tgt_types_set.Add (ret_type);
1086 // Explicit conv rules
1088 if (apply_explicit_conv_rules) {
1089 var candidate_set = new List<TypeSpec> ();
1091 foreach (TypeSpec ret_type in tgt_types_set) {
1092 var expr = new EmptyExpression (ret_type);
1094 if (ImplicitStandardConversionExists (expr, target))
1095 candidate_set.Add (ret_type);
1098 if (candidate_set.Count != 0)
1099 return FindMostEncompassingType (candidate_set);
1103 // Okay, final case !
1105 if (apply_explicit_conv_rules)
1106 return FindMostEncompassedType (tgt_types_set);
1108 return FindMostEncompassingType (tgt_types_set);
1112 /// User-defined Implicit conversions
1114 static public Expression ImplicitUserConversion (ResolveContext ec, Expression source, TypeSpec target, Location loc)
1116 return UserDefinedConversion (ec, source, target, UserConversionRestriction.ImplicitOnly, loc);
1120 /// User-defined Explicit conversions
1122 static Expression ExplicitUserConversion (ResolveContext ec, Expression source, TypeSpec target, Location loc)
1124 return UserDefinedConversion (ec, source, target, 0, loc);
1127 static void FindApplicableUserDefinedConversionOperators (ResolveContext rc, IList<MemberSpec> operators, Expression source, TypeSpec target, UserConversionRestriction restr, ref List<MethodSpec> candidates)
1129 if (source.Type.IsInterface) {
1130 // Neither A nor B are interface-types
1134 // For a conversion operator to be applicable, it must be possible
1135 // to perform a standard conversion from the source type to
1136 // the operand type of the operator, and it must be possible
1137 // to perform a standard conversion from the result type of
1138 // the operator to the target type.
1140 Expression texpr = null;
1142 foreach (MethodSpec op in operators) {
1144 // Can be null because MemberCache.GetUserOperator does not resize the array
1148 var t = op.Parameters.Types[0];
1149 if (source.Type != t && !ImplicitStandardConversionExists (rc, source, t)) {
1150 if ((restr & UserConversionRestriction.ImplicitOnly) != 0)
1153 if (!ImplicitStandardConversionExists (new EmptyExpression (t), source.Type))
1157 if ((restr & UserConversionRestriction.NullableSourceOnly) != 0 && !t.IsNullableType)
1166 if (t.IsNullableType)
1167 t = Nullable.NullableInfo.GetUnderlyingType (t);
1169 if (!ImplicitStandardConversionExists (new EmptyExpression (t), target)) {
1170 if ((restr & UserConversionRestriction.ImplicitOnly) != 0)
1174 texpr = new EmptyExpression (target);
1176 if (!ImplicitStandardConversionExists (texpr, t))
1181 if (candidates == null)
1182 candidates = new List<MethodSpec> ();
1184 candidates.Add (op);
1189 // User-defined conversions
1191 public static Expression UserDefinedConversion (ResolveContext rc, Expression source, TypeSpec target, UserConversionRestriction restr, Location loc)
1193 List<MethodSpec> candidates = null;
1196 // If S or T are nullable types, source_type and target_type are their underlying types
1197 // otherwise source_type and target_type are equal to S and T respectively.
1199 TypeSpec source_type = source.Type;
1200 TypeSpec target_type = target;
1201 Expression source_type_expr;
1202 bool nullable_source = false;
1203 var implicitOnly = (restr & UserConversionRestriction.ImplicitOnly) != 0;
1205 if (source_type.IsNullableType) {
1206 // No unwrapping conversion S? -> T for non-reference types
1207 if (implicitOnly && !TypeSpec.IsReferenceType (target_type) && !target_type.IsNullableType) {
1208 source_type_expr = source;
1210 source_type_expr = Nullable.Unwrap.CreateUnwrapped (source);
1211 source_type = source_type_expr.Type;
1212 nullable_source = true;
1215 source_type_expr = source;
1218 if (target_type.IsNullableType)
1219 target_type = Nullable.NullableInfo.GetUnderlyingType (target_type);
1221 // Only these containers can contain a user defined implicit or explicit operators
1222 const MemberKind user_conversion_kinds = MemberKind.Class | MemberKind.Struct | MemberKind.TypeParameter;
1224 if ((source_type.Kind & user_conversion_kinds) != 0 && source_type.BuiltinType != BuiltinTypeSpec.Type.Decimal) {
1225 bool declared_only = source_type.IsStruct;
1227 var operators = MemberCache.GetUserOperator (source_type, Operator.OpType.Implicit, declared_only);
1228 if (operators != null) {
1229 FindApplicableUserDefinedConversionOperators (rc, operators, source_type_expr, target_type, restr, ref candidates);
1232 if (!implicitOnly) {
1233 operators = MemberCache.GetUserOperator (source_type, Operator.OpType.Explicit, declared_only);
1234 if (operators != null) {
1235 FindApplicableUserDefinedConversionOperators (rc, operators, source_type_expr, target_type, restr, ref candidates);
1240 if ((target.Kind & user_conversion_kinds) != 0 && target_type.BuiltinType != BuiltinTypeSpec.Type.Decimal) {
1241 bool declared_only = target.IsStruct || implicitOnly;
1243 var operators = MemberCache.GetUserOperator (target_type, Operator.OpType.Implicit, declared_only);
1244 if (operators != null) {
1245 FindApplicableUserDefinedConversionOperators (rc, operators, source_type_expr, target_type, restr, ref candidates);
1248 if (!implicitOnly) {
1249 operators = MemberCache.GetUserOperator (target_type, Operator.OpType.Explicit, declared_only);
1250 if (operators != null) {
1251 FindApplicableUserDefinedConversionOperators (rc, operators, source_type_expr, target_type, restr, ref candidates);
1256 if (candidates == null)
1260 // Find the most specific conversion operator
1262 MethodSpec most_specific_operator;
1264 if (candidates.Count == 1) {
1265 most_specific_operator = candidates[0];
1266 s_x = most_specific_operator.Parameters.Types[0];
1267 t_x = most_specific_operator.ReturnType;
1270 // Pass original source type to find the best match against input type and
1271 // not the unwrapped expression
1273 s_x = FindMostSpecificSource (rc, candidates, source.Type, source_type_expr, !implicitOnly);
1277 t_x = FindMostSpecificTarget (candidates, target, !implicitOnly);
1281 most_specific_operator = null;
1282 for (int i = 0; i < candidates.Count; ++i) {
1283 if (candidates[i].ReturnType == t_x && candidates[i].Parameters.Types[0] == s_x) {
1284 most_specific_operator = candidates[i];
1289 if (most_specific_operator == null) {
1291 // Unless running in probing more
1293 if ((restr & UserConversionRestriction.ProbingOnly) == 0) {
1294 MethodSpec ambig_arg = candidates [0];
1295 most_specific_operator = candidates [1];
1297 foreach (var candidate in candidates) {
1298 if (candidate.ReturnType == t_x)
1299 most_specific_operator = candidate;
1300 else if (candidate.Parameters.Types[0] == s_x)
1301 ambig_arg = candidate;
1304 rc.Report.Error (457, loc,
1305 "Ambiguous user defined operators `{0}' and `{1}' when converting from `{2}' to `{3}'",
1306 ambig_arg.GetSignatureForError (), most_specific_operator.GetSignatureForError (),
1307 source.Type.GetSignatureForError (), target.GetSignatureForError ());
1310 return ErrorExpression.Instance;
1315 // Convert input type when it's different to best operator argument
1317 if (s_x != source_type) {
1318 var c = source as Constant;
1320 source = c.Reduce (rc, s_x);
1326 source = implicitOnly ?
1327 ImplicitConversionStandard (rc, source_type_expr, s_x, loc) :
1328 ExplicitConversionStandard (rc, source_type_expr, s_x, loc);
1331 source = source_type_expr;
1334 source = new UserCast (most_specific_operator, source, loc).Resolve (rc);
1337 // Convert result type when it's different to best operator return type
1339 if (t_x != target_type) {
1341 // User operator is of T?
1343 if (t_x.IsNullableType && (target.IsNullableType || !implicitOnly)) {
1345 // User operator return type does not match target type we need
1346 // yet another conversion. This should happen for promoted numeric
1349 if (t_x != target) {
1350 var unwrap = Nullable.Unwrap.CreateUnwrapped (source);
1352 source = implicitOnly ?
1353 ImplicitConversionStandard (rc, unwrap, target_type, loc) :
1354 ExplicitConversionStandard (rc, unwrap, target_type, loc);
1359 if (target.IsNullableType)
1360 source = new Nullable.LiftedConversion (source, unwrap, target).Resolve (rc);
1363 source = implicitOnly ?
1364 ImplicitConversionStandard (rc, source, target_type, loc) :
1365 ExplicitConversionStandard (rc, source, target_type, loc);
1374 // Source expression is of nullable type and underlying conversion returns
1375 // only non-nullable type we need to lift it manually
1377 if (nullable_source && !s_x.IsNullableType)
1378 return new Nullable.LiftedConversion (source, source_type_expr, target).Resolve (rc);
1381 // Target is of nullable type but source type is not, wrap the result expression
1383 if (target.IsNullableType && !t_x.IsNullableType)
1384 source = Nullable.Wrap.Create (source, target);
1390 /// Converts implicitly the resolved expression `expr' into the
1391 /// `target_type'. It returns a new expression that can be used
1392 /// in a context that expects a `target_type'.
1394 static public Expression ImplicitConversion (ResolveContext ec, Expression expr,
1395 TypeSpec target_type, Location loc)
1399 if (target_type == null)
1400 throw new Exception ("Target type is null");
1402 e = ImplicitConversionStandard (ec, expr, target_type, loc);
1406 e = ImplicitUserConversion (ec, expr, target_type, loc);
1415 /// Attempts to apply the `Standard Implicit
1416 /// Conversion' rules to the expression `expr' into
1417 /// the `target_type'. It returns a new expression
1418 /// that can be used in a context that expects a
1421 /// This is different from `ImplicitConversion' in that the
1422 /// user defined implicit conversions are excluded.
1424 static public Expression ImplicitConversionStandard (ResolveContext ec, Expression expr,
1425 TypeSpec target_type, Location loc)
1427 return ImplicitConversionStandard (ec, expr, target_type, loc, false);
1430 static Expression ImplicitConversionStandard (ResolveContext ec, Expression expr, TypeSpec target_type, Location loc, bool explicit_cast)
1432 if (expr.eclass == ExprClass.MethodGroup){
1433 if (!target_type.IsDelegate){
1438 // Only allow anonymous method conversions on post ISO_1
1440 if (ec.Module.Compiler.Settings.Version != LanguageVersion.ISO_1){
1441 MethodGroupExpr mg = expr as MethodGroupExpr;
1443 return new ImplicitDelegateCreation (target_type, mg, loc).Resolve (ec);
1447 TypeSpec expr_type = expr.Type;
1450 if (expr_type == target_type) {
1451 if (expr_type != InternalType.NullLiteral && expr_type != InternalType.AnonymousMethod && expr_type != InternalType.ThrowExpr)
1456 if (expr_type.BuiltinType == BuiltinTypeSpec.Type.Dynamic) {
1457 switch (target_type.Kind) {
1458 case MemberKind.ArrayType:
1459 case MemberKind.Class:
1460 if (target_type.BuiltinType == BuiltinTypeSpec.Type.Object)
1461 return EmptyCast.Create (expr, target_type);
1463 goto case MemberKind.Struct;
1464 case MemberKind.Struct:
1465 case MemberKind.Delegate:
1466 case MemberKind.Enum:
1467 case MemberKind.Interface:
1468 case MemberKind.TypeParameter:
1469 Arguments args = new Arguments (1);
1470 args.Add (new Argument (expr));
1471 return new DynamicConversion (target_type, explicit_cast ? CSharpBinderFlags.ConvertExplicit : 0, args, loc).Resolve (ec);
1477 if (expr_type == InternalType.ThrowExpr) {
1478 return target_type.Kind == MemberKind.InternalCompilerType ? null : EmptyCast.Create (expr, target_type);
1481 if (target_type.IsNullableType)
1482 return ImplicitNulableConversion (ec, expr, target_type);
1485 // Attempt to do the implicit constant expression conversions
1487 Constant c = expr as Constant;
1490 c = c.ConvertImplicitly (target_type);
1492 throw new InternalErrorException ("Conversion error", loc);
1498 if (expr_type.IsTupleType) {
1499 if (target_type.IsTupleType)
1500 return ImplicitTupleLiteralConversion (ec, expr, target_type, loc);
1502 if (expr is TupleLiteral && TupleLiteral.ContainsNoTypeElement (expr_type))
1506 e = ImplicitNumericConversion (expr, expr_type, target_type);
1510 e = ImplicitReferenceConversion (expr, target_type, explicit_cast);
1514 e = ImplicitBoxingConversion (expr, expr_type, target_type);
1518 if (expr is IntegralConstant && target_type.IsEnum){
1519 var i = (IntegralConstant) expr;
1521 // LAMESPEC: csc allows any constant like 0 values to be converted, including const float f = 0.0
1523 // An implicit enumeration conversion permits the decimal-integer-literal 0
1524 // to be converted to any enum-type and to any nullable-type whose underlying
1525 // type is an enum-type
1527 if (i.IsZeroInteger) {
1528 // Recreate 0 literal to remove any collected conversions
1529 return new EnumConstant (new IntLiteral (ec.BuiltinTypes, 0, i.Location), target_type);
1533 var target_pc = target_type as PointerContainer;
1534 if (target_pc != null) {
1535 if (expr_type.IsPointer) {
1537 // Pointer types are same when they have same element types
1539 if (expr_type == target_pc)
1542 if (target_pc.Element.Kind == MemberKind.Void)
1543 return EmptyCast.Create (expr, target_type);
1548 if (expr_type == InternalType.NullLiteral)
1549 return new NullPointer (target_type, loc);
1552 if (expr_type == InternalType.AnonymousMethod){
1553 AnonymousMethodExpression ame = (AnonymousMethodExpression) expr;
1554 Expression am = ame.Compatible (ec, target_type);
1556 return am.Resolve (ec);
1558 // Avoid CS1503 after CS1661
1559 return ErrorExpression.Instance;
1562 if (expr_type == InternalType.Arglist && target_type == ec.Module.PredefinedTypes.ArgIterator.TypeSpec)
1566 // dynamic erasure conversion on value types
1568 if (expr_type.IsStruct && TypeSpecComparer.IsEqual (expr_type, target_type))
1569 return expr_type == target_type ? expr : EmptyCast.Create (expr, target_type);
1571 var interpolated_string = expr as InterpolatedString;
1572 if (interpolated_string != null) {
1573 if (target_type == ec.Module.PredefinedTypes.IFormattable.TypeSpec || target_type == ec.Module.PredefinedTypes.FormattableString.TypeSpec)
1574 return interpolated_string.ConvertTo (ec, target_type);
1581 /// Attempts to implicitly convert `source' into `target_type', using
1582 /// ImplicitConversion. If there is no implicit conversion, then
1583 /// an error is signaled
1585 public static Expression ImplicitConversionRequired (ResolveContext ec, Expression source,
1586 TypeSpec target_type, Location loc)
1588 Expression e = ImplicitConversion (ec, source, target_type, loc);
1592 if (target_type != InternalType.ErrorType)
1593 source.Error_ValueCannotBeConverted (ec, target_type, false);
1599 /// Performs the explicit numeric conversions
1601 /// There are a few conversions that are not part of the C# standard,
1602 /// they were interim hacks in the C# compiler that were supposed to
1603 /// become explicit operators in the UIntPtr class and IntPtr class,
1604 /// but for historical reasons it did not happen, so the C# compiler
1605 /// ended up with these special hacks.
1607 /// See bug 59800 for details.
1609 /// The conversion are:
1619 public static Expression ExplicitNumericConversion (ResolveContext rc, Expression expr, TypeSpec target_type)
1621 // Not all predefined explicit numeric conversion are
1622 // defined here, for some of them (mostly IntPtr/UIntPtr) we
1623 // defer to user-operator handling which is now perfect but
1626 // LAMESPEC: Undocumented IntPtr/UIntPtr conversions
1627 // IntPtr -> uint uses int
1628 // UIntPtr -> long uses ulong
1631 switch (expr.Type.BuiltinType) {
1632 case BuiltinTypeSpec.Type.SByte:
1634 // From sbyte to byte, ushort, uint, ulong, char, uintptr
1636 switch (target_type.BuiltinType) {
1637 case BuiltinTypeSpec.Type.Byte:
1638 return new ConvCast (expr, target_type, ConvCast.Mode.I1_U1);
1639 case BuiltinTypeSpec.Type.UShort:
1640 return new ConvCast (expr, target_type, ConvCast.Mode.I1_U2);
1641 case BuiltinTypeSpec.Type.UInt:
1642 return new ConvCast (expr, target_type, ConvCast.Mode.I1_U4);
1643 case BuiltinTypeSpec.Type.ULong:
1644 return new ConvCast (expr, target_type, ConvCast.Mode.I1_U8);
1645 case BuiltinTypeSpec.Type.Char:
1646 return new ConvCast (expr, target_type, ConvCast.Mode.I1_CH);
1648 // One of the built-in conversions that belonged in the class library
1649 case BuiltinTypeSpec.Type.UIntPtr:
1650 return new OperatorCast (new ConvCast (expr, rc.BuiltinTypes.ULong, ConvCast.Mode.I1_U8), target_type, target_type, true);
1653 case BuiltinTypeSpec.Type.Byte:
1655 // From byte to sbyte and char
1657 switch (target_type.BuiltinType) {
1658 case BuiltinTypeSpec.Type.SByte:
1659 return new ConvCast (expr, target_type, ConvCast.Mode.U1_I1);
1660 case BuiltinTypeSpec.Type.Char:
1661 return new ConvCast (expr, target_type, ConvCast.Mode.U1_CH);
1664 case BuiltinTypeSpec.Type.Short:
1666 // From short to sbyte, byte, ushort, uint, ulong, char, uintptr
1668 switch (target_type.BuiltinType) {
1669 case BuiltinTypeSpec.Type.SByte:
1670 return new ConvCast (expr, target_type, ConvCast.Mode.I2_I1);
1671 case BuiltinTypeSpec.Type.Byte:
1672 return new ConvCast (expr, target_type, ConvCast.Mode.I2_U1);
1673 case BuiltinTypeSpec.Type.UShort:
1674 return new ConvCast (expr, target_type, ConvCast.Mode.I2_U2);
1675 case BuiltinTypeSpec.Type.UInt:
1676 return new ConvCast (expr, target_type, ConvCast.Mode.I2_U4);
1677 case BuiltinTypeSpec.Type.ULong:
1678 return new ConvCast (expr, target_type, ConvCast.Mode.I2_U8);
1679 case BuiltinTypeSpec.Type.Char:
1680 return new ConvCast (expr, target_type, ConvCast.Mode.I2_CH);
1682 // One of the built-in conversions that belonged in the class library
1683 case BuiltinTypeSpec.Type.UIntPtr:
1684 return new OperatorCast (new ConvCast (expr, rc.BuiltinTypes.ULong, ConvCast.Mode.I2_U8), target_type, target_type, true);
1687 case BuiltinTypeSpec.Type.UShort:
1689 // From ushort to sbyte, byte, short, char
1691 switch (target_type.BuiltinType) {
1692 case BuiltinTypeSpec.Type.SByte:
1693 return new ConvCast (expr, target_type, ConvCast.Mode.U2_I1);
1694 case BuiltinTypeSpec.Type.Byte:
1695 return new ConvCast (expr, target_type, ConvCast.Mode.U2_U1);
1696 case BuiltinTypeSpec.Type.Short:
1697 return new ConvCast (expr, target_type, ConvCast.Mode.U2_I2);
1698 case BuiltinTypeSpec.Type.Char:
1699 return new ConvCast (expr, target_type, ConvCast.Mode.U2_CH);
1702 case BuiltinTypeSpec.Type.Int:
1704 // From int to sbyte, byte, short, ushort, uint, ulong, char, uintptr
1706 switch (target_type.BuiltinType) {
1707 case BuiltinTypeSpec.Type.SByte:
1708 return new ConvCast (expr, target_type, ConvCast.Mode.I4_I1);
1709 case BuiltinTypeSpec.Type.Byte:
1710 return new ConvCast (expr, target_type, ConvCast.Mode.I4_U1);
1711 case BuiltinTypeSpec.Type.Short:
1712 return new ConvCast (expr, target_type, ConvCast.Mode.I4_I2);
1713 case BuiltinTypeSpec.Type.UShort:
1714 return new ConvCast (expr, target_type, ConvCast.Mode.I4_U2);
1715 case BuiltinTypeSpec.Type.UInt:
1716 return new ConvCast (expr, target_type, ConvCast.Mode.I4_U4);
1717 case BuiltinTypeSpec.Type.ULong:
1718 return new ConvCast (expr, target_type, ConvCast.Mode.I4_U8);
1719 case BuiltinTypeSpec.Type.Char:
1720 return new ConvCast (expr, target_type, ConvCast.Mode.I4_CH);
1722 // One of the built-in conversions that belonged in the class library
1723 case BuiltinTypeSpec.Type.UIntPtr:
1724 return new OperatorCast (new ConvCast (expr, rc.BuiltinTypes.ULong, ConvCast.Mode.I2_U8), target_type, target_type, true);
1727 case BuiltinTypeSpec.Type.UInt:
1729 // From uint to sbyte, byte, short, ushort, int, char
1731 switch (target_type.BuiltinType) {
1732 case BuiltinTypeSpec.Type.SByte:
1733 return new ConvCast (expr, target_type, ConvCast.Mode.U4_I1);
1734 case BuiltinTypeSpec.Type.Byte:
1735 return new ConvCast (expr, target_type, ConvCast.Mode.U4_U1);
1736 case BuiltinTypeSpec.Type.Short:
1737 return new ConvCast (expr, target_type, ConvCast.Mode.U4_I2);
1738 case BuiltinTypeSpec.Type.UShort:
1739 return new ConvCast (expr, target_type, ConvCast.Mode.U4_U2);
1740 case BuiltinTypeSpec.Type.Int:
1741 return new ConvCast (expr, target_type, ConvCast.Mode.U4_I4);
1742 case BuiltinTypeSpec.Type.Char:
1743 return new ConvCast (expr, target_type, ConvCast.Mode.U4_CH);
1746 case BuiltinTypeSpec.Type.Long:
1748 // From long to sbyte, byte, short, ushort, int, uint, ulong, char
1750 switch (target_type.BuiltinType) {
1751 case BuiltinTypeSpec.Type.SByte:
1752 return new ConvCast (expr, target_type, ConvCast.Mode.I8_I1);
1753 case BuiltinTypeSpec.Type.Byte:
1754 return new ConvCast (expr, target_type, ConvCast.Mode.I8_U1);
1755 case BuiltinTypeSpec.Type.Short:
1756 return new ConvCast (expr, target_type, ConvCast.Mode.I8_I2);
1757 case BuiltinTypeSpec.Type.UShort:
1758 return new ConvCast (expr, target_type, ConvCast.Mode.I8_U2);
1759 case BuiltinTypeSpec.Type.Int:
1760 return new ConvCast (expr, target_type, ConvCast.Mode.I8_I4);
1761 case BuiltinTypeSpec.Type.UInt:
1762 return new ConvCast (expr, target_type, ConvCast.Mode.I8_U4);
1763 case BuiltinTypeSpec.Type.ULong:
1764 return new ConvCast (expr, target_type, ConvCast.Mode.I8_U8);
1765 case BuiltinTypeSpec.Type.Char:
1766 return new ConvCast (expr, target_type, ConvCast.Mode.I8_CH);
1769 case BuiltinTypeSpec.Type.ULong:
1771 // From ulong to sbyte, byte, short, ushort, int, uint, long, char
1773 switch (target_type.BuiltinType) {
1774 case BuiltinTypeSpec.Type.SByte:
1775 return new ConvCast (expr, target_type, ConvCast.Mode.U8_I1);
1776 case BuiltinTypeSpec.Type.Byte:
1777 return new ConvCast (expr, target_type, ConvCast.Mode.U8_U1);
1778 case BuiltinTypeSpec.Type.Short:
1779 return new ConvCast (expr, target_type, ConvCast.Mode.U8_I2);
1780 case BuiltinTypeSpec.Type.UShort:
1781 return new ConvCast (expr, target_type, ConvCast.Mode.U8_U2);
1782 case BuiltinTypeSpec.Type.Int:
1783 return new ConvCast (expr, target_type, ConvCast.Mode.U8_I4);
1784 case BuiltinTypeSpec.Type.UInt:
1785 return new ConvCast (expr, target_type, ConvCast.Mode.U8_U4);
1786 case BuiltinTypeSpec.Type.Long:
1787 return new ConvCast (expr, target_type, ConvCast.Mode.U8_I8);
1788 case BuiltinTypeSpec.Type.Char:
1789 return new ConvCast (expr, target_type, ConvCast.Mode.U8_CH);
1791 // One of the built-in conversions that belonged in the class library
1792 case BuiltinTypeSpec.Type.IntPtr:
1793 return new OperatorCast (EmptyCast.Create (expr, rc.BuiltinTypes.Long), target_type, true);
1796 case BuiltinTypeSpec.Type.Char:
1798 // From char to sbyte, byte, short
1800 switch (target_type.BuiltinType) {
1801 case BuiltinTypeSpec.Type.SByte:
1802 return new ConvCast (expr, target_type, ConvCast.Mode.CH_I1);
1803 case BuiltinTypeSpec.Type.Byte:
1804 return new ConvCast (expr, target_type, ConvCast.Mode.CH_U1);
1805 case BuiltinTypeSpec.Type.Short:
1806 return new ConvCast (expr, target_type, ConvCast.Mode.CH_I2);
1809 case BuiltinTypeSpec.Type.Float:
1811 // From float to sbyte, byte, short,
1812 // ushort, int, uint, long, ulong, char
1815 switch (target_type.BuiltinType) {
1816 case BuiltinTypeSpec.Type.SByte:
1817 return new ConvCast (expr, target_type, ConvCast.Mode.R4_I1);
1818 case BuiltinTypeSpec.Type.Byte:
1819 return new ConvCast (expr, target_type, ConvCast.Mode.R4_U1);
1820 case BuiltinTypeSpec.Type.Short:
1821 return new ConvCast (expr, target_type, ConvCast.Mode.R4_I2);
1822 case BuiltinTypeSpec.Type.UShort:
1823 return new ConvCast (expr, target_type, ConvCast.Mode.R4_U2);
1824 case BuiltinTypeSpec.Type.Int:
1825 return new ConvCast (expr, target_type, ConvCast.Mode.R4_I4);
1826 case BuiltinTypeSpec.Type.UInt:
1827 return new ConvCast (expr, target_type, ConvCast.Mode.R4_U4);
1828 case BuiltinTypeSpec.Type.Long:
1829 return new ConvCast (expr, target_type, ConvCast.Mode.R4_I8);
1830 case BuiltinTypeSpec.Type.ULong:
1831 return new ConvCast (expr, target_type, ConvCast.Mode.R4_U8);
1832 case BuiltinTypeSpec.Type.Char:
1833 return new ConvCast (expr, target_type, ConvCast.Mode.R4_CH);
1834 case BuiltinTypeSpec.Type.Decimal:
1835 return new OperatorCast (expr, target_type, true);
1838 case BuiltinTypeSpec.Type.Double:
1840 // From double to sbyte, byte, short,
1841 // ushort, int, uint, long, ulong,
1842 // char, float or decimal
1844 switch (target_type.BuiltinType) {
1845 case BuiltinTypeSpec.Type.SByte:
1846 return new ConvCast (expr, target_type, ConvCast.Mode.R8_I1);
1847 case BuiltinTypeSpec.Type.Byte:
1848 return new ConvCast (expr, target_type, ConvCast.Mode.R8_U1);
1849 case BuiltinTypeSpec.Type.Short:
1850 return new ConvCast (expr, target_type, ConvCast.Mode.R8_I2);
1851 case BuiltinTypeSpec.Type.UShort:
1852 return new ConvCast (expr, target_type, ConvCast.Mode.R8_U2);
1853 case BuiltinTypeSpec.Type.Int:
1854 return new ConvCast (expr, target_type, ConvCast.Mode.R8_I4);
1855 case BuiltinTypeSpec.Type.UInt:
1856 return new ConvCast (expr, target_type, ConvCast.Mode.R8_U4);
1857 case BuiltinTypeSpec.Type.Long:
1858 return new ConvCast (expr, target_type, ConvCast.Mode.R8_I8);
1859 case BuiltinTypeSpec.Type.ULong:
1860 return new ConvCast (expr, target_type, ConvCast.Mode.R8_U8);
1861 case BuiltinTypeSpec.Type.Char:
1862 return new ConvCast (expr, target_type, ConvCast.Mode.R8_CH);
1863 case BuiltinTypeSpec.Type.Float:
1864 return new ConvCast (expr, target_type, ConvCast.Mode.R8_R4);
1865 case BuiltinTypeSpec.Type.Decimal:
1866 return new OperatorCast (expr, target_type, true);
1869 case BuiltinTypeSpec.Type.UIntPtr:
1871 // Various built-in conversions that belonged in the class library
1873 // from uintptr to sbyte, short, int32
1875 switch (target_type.BuiltinType) {
1876 case BuiltinTypeSpec.Type.SByte:
1877 return new ConvCast (new OperatorCast (expr, expr.Type, rc.BuiltinTypes.UInt, true), target_type, ConvCast.Mode.U4_I1);
1878 case BuiltinTypeSpec.Type.Short:
1879 return new ConvCast (new OperatorCast (expr, expr.Type, rc.BuiltinTypes.UInt, true), target_type, ConvCast.Mode.U4_I2);
1880 case BuiltinTypeSpec.Type.Int:
1881 return EmptyCast.Create (new OperatorCast (expr, expr.Type, rc.BuiltinTypes.UInt, true), target_type);
1882 case BuiltinTypeSpec.Type.UInt:
1883 return new OperatorCast (expr, expr.Type, target_type, true);
1884 case BuiltinTypeSpec.Type.Long:
1885 return EmptyCast.Create (new OperatorCast (expr, expr.Type, rc.BuiltinTypes.ULong, true), target_type);
1888 case BuiltinTypeSpec.Type.IntPtr:
1889 if (target_type.BuiltinType == BuiltinTypeSpec.Type.UInt)
1890 return EmptyCast.Create (new OperatorCast (expr, expr.Type, rc.BuiltinTypes.Int, true), target_type);
1891 if (target_type.BuiltinType == BuiltinTypeSpec.Type.ULong)
1892 return EmptyCast.Create (new OperatorCast (expr, expr.Type, rc.BuiltinTypes.Long, true), target_type);
1895 case BuiltinTypeSpec.Type.Decimal:
1896 // From decimal to sbyte, byte, short,
1897 // ushort, int, uint, long, ulong, char,
1899 switch (target_type.BuiltinType) {
1900 case BuiltinTypeSpec.Type.SByte:
1901 case BuiltinTypeSpec.Type.Byte:
1902 case BuiltinTypeSpec.Type.Short:
1903 case BuiltinTypeSpec.Type.UShort:
1904 case BuiltinTypeSpec.Type.Int:
1905 case BuiltinTypeSpec.Type.UInt:
1906 case BuiltinTypeSpec.Type.Long:
1907 case BuiltinTypeSpec.Type.ULong:
1908 case BuiltinTypeSpec.Type.Char:
1909 case BuiltinTypeSpec.Type.Float:
1910 case BuiltinTypeSpec.Type.Double:
1911 return new OperatorCast (expr, expr.Type, target_type, true);
1921 /// Returns whether an explicit reference conversion can be performed
1922 /// from source_type to target_type
1924 public static bool ExplicitReferenceConversionExists (TypeSpec source_type, TypeSpec target_type)
1926 Expression e = ExplicitReferenceConversion (null, source_type, target_type);
1930 if (e == EmptyExpression.Null)
1933 throw new InternalErrorException ("Invalid probing conversion result");
1937 /// Implements Explicit Reference conversions
1939 static Expression ExplicitReferenceConversion (Expression source, TypeSpec source_type, TypeSpec target_type)
1942 // From object to a generic parameter
1944 if (source_type.BuiltinType == BuiltinTypeSpec.Type.Object && TypeManager.IsGenericParameter (target_type))
1945 return source == null ? EmptyExpression.Null : new UnboxCast (source, target_type);
1948 // Explicit type parameter conversion from T
1950 if (source_type.Kind == MemberKind.TypeParameter)
1951 return ExplicitTypeParameterConversionFromT (source, source_type, target_type);
1953 bool target_is_value_type = target_type.Kind == MemberKind.Struct || target_type.Kind == MemberKind.Enum;
1956 // Unboxing conversion from System.ValueType to any non-nullable-value-type
1958 if (source_type.BuiltinType == BuiltinTypeSpec.Type.ValueType && target_is_value_type)
1959 return source == null ? EmptyExpression.Null : new UnboxCast (source, target_type);
1962 // From object or dynamic to any reference type or value type (unboxing)
1964 if (source_type.BuiltinType == BuiltinTypeSpec.Type.Object || source_type.BuiltinType == BuiltinTypeSpec.Type.Dynamic) {
1965 if (target_type.IsPointer)
1969 source == null ? EmptyExpression.Null :
1970 target_is_value_type ? new UnboxCast (source, target_type) :
1971 source is Constant ? (Expression) new EmptyConstantCast ((Constant) source, target_type) :
1972 new ClassCast (source, target_type);
1976 // From any class S to any class-type T, provided S is a base class of T
1978 if (source_type.Kind == MemberKind.Class && TypeSpec.IsBaseClass (target_type, source_type, true))
1979 return source == null ? EmptyExpression.Null : new ClassCast (source, target_type);
1982 // From any interface-type S to to any class type T, provided T is not
1983 // sealed, or provided T implements S.
1985 // This also covers Explicit conversions involving type parameters
1986 // section From any interface type to T
1988 if (source_type.Kind == MemberKind.Interface) {
1989 if (!target_type.IsSealed || target_type.ImplementsInterface (source_type, true)) {
1991 return EmptyExpression.Null;
1994 // Unboxing conversion from any interface-type to any non-nullable-value-type that
1995 // implements the interface-type
1997 return target_is_value_type ? new UnboxCast (source, target_type) : (Expression) new ClassCast (source, target_type);
2001 // From System.Collections.Generic.IList<T> and its base interfaces to a one-dimensional
2002 // array type S[], provided there is an implicit or explicit reference conversion from S to T.
2004 var target_array = target_type as ArrayContainer;
2005 if (target_array != null && IList_To_Array (source_type, target_array))
2006 return source == null ? EmptyExpression.Null : new ClassCast (source, target_type);
2011 var source_array = source_type as ArrayContainer;
2012 if (source_array != null) {
2013 var target_array = target_type as ArrayContainer;
2014 if (target_array != null) {
2016 // From System.Array to any array-type
2018 if (source_type.BuiltinType == BuiltinTypeSpec.Type.Array)
2019 return source == null ? EmptyExpression.Null : new ClassCast (source, target_type);
2022 // From an array type S with an element type Se to an array type T with an
2023 // element type Te provided all the following are true:
2024 // * S and T differe only in element type, in other words, S and T
2025 // have the same number of dimensions.
2026 // * Both Se and Te are reference types
2027 // * An explicit reference conversions exist from Se to Te
2029 if (source_array.Rank == target_array.Rank) {
2031 source_type = source_array.Element;
2032 var target_element = target_array.Element;
2035 // LAMESPEC: Type parameters are special cased somehow but
2036 // only when both source and target elements are type parameters
2038 if ((source_type.Kind & target_element.Kind & MemberKind.TypeParameter) == MemberKind.TypeParameter) {
2040 // Conversion is allowed unless source element type has struct constrain
2042 if (TypeSpec.IsValueType (source_type))
2045 if (!TypeSpec.IsReferenceType (source_type))
2049 if (!TypeSpec.IsReferenceType (target_element))
2052 if (ExplicitReferenceConversionExists (source_type, target_element))
2053 return source == null ? EmptyExpression.Null : new ClassCast (source, target_type);
2060 // From a single-dimensional array type S[] to System.Collections.Generic.IList<T> and its base interfaces,
2061 // provided that there is an explicit reference conversion from S to T
2063 if (ArrayToIList (source_array, target_type, true))
2064 return source == null ? EmptyExpression.Null : new ClassCast (source, target_type);
2070 // From any class type S to any interface T, provides S is not sealed
2071 // and provided S does not implement T.
2073 if (target_type.IsInterface && !source_type.IsSealed && !source_type.ImplementsInterface (target_type, true)) {
2074 return source == null ? EmptyExpression.Null : new ClassCast (source, target_type);
2078 // From System delegate to any delegate-type
2080 if (source_type.BuiltinType == BuiltinTypeSpec.Type.Delegate && target_type.IsDelegate)
2081 return source == null ? EmptyExpression.Null : new ClassCast (source, target_type);
2084 // From variant generic delegate to same variant generic delegate type
2086 if (source_type.IsDelegate && target_type.IsDelegate && source_type.MemberDefinition == target_type.MemberDefinition) {
2087 var tparams = source_type.MemberDefinition.TypeParameters;
2088 var targs_src = source_type.TypeArguments;
2089 var targs_dst = target_type.TypeArguments;
2091 for (i = 0; i < tparams.Length; ++i) {
2093 // If TP is invariant, types have to be identical
2095 if (TypeSpecComparer.IsEqual (targs_src[i], targs_dst[i]))
2098 if (tparams[i].Variance == Variance.Covariant) {
2100 //If TP is covariant, an implicit or explicit identity or reference conversion is required
2102 if (ImplicitReferenceConversionExists (targs_src[i], targs_dst[i]))
2105 if (ExplicitReferenceConversionExists (targs_src[i], targs_dst[i]))
2108 } else if (tparams[i].Variance == Variance.Contravariant) {
2110 //If TP is contravariant, both are either identical or reference types
2112 if (TypeSpec.IsReferenceType (targs_src[i]) && TypeSpec.IsReferenceType (targs_dst[i]))
2119 if (i == tparams.Length)
2120 return source == null ? EmptyExpression.Null : new ClassCast (source, target_type);
2123 var tps = target_type as TypeParameterSpec;
2125 return ExplicitTypeParameterConversionToT (source, source_type, tps);
2131 /// Performs an explicit conversion of the expression `expr' whose
2132 /// type is expr.Type to `target_type'.
2134 static public Expression ExplicitConversionCore (ResolveContext ec, Expression expr,
2135 TypeSpec target_type, Location loc)
2137 TypeSpec expr_type = expr.Type;
2139 // Explicit conversion includes implicit conversion and it used for enum underlying types too
2140 Expression ne = ImplicitConversionStandard (ec, expr, target_type, loc, true);
2144 if (expr_type.IsEnum) {
2145 TypeSpec real_target = target_type.IsEnum ? EnumSpec.GetUnderlyingType (target_type) : target_type;
2146 Expression underlying = EmptyCast.Create (expr, EnumSpec.GetUnderlyingType (expr_type));
2147 if (underlying.Type == real_target)
2151 ne = ImplicitNumericConversion (underlying, real_target);
2154 ne = ExplicitNumericConversion (ec, underlying, real_target);
2157 // LAMESPEC: IntPtr and UIntPtr conversion to any Enum is allowed
2159 if (ne == null && (real_target.BuiltinType == BuiltinTypeSpec.Type.IntPtr || real_target.BuiltinType == BuiltinTypeSpec.Type.UIntPtr))
2160 ne = ExplicitUserConversion (ec, underlying, real_target, loc);
2162 return ne != null ? EmptyCast.Create (ne, target_type) : null;
2165 if (target_type.IsEnum) {
2167 // System.Enum can be unboxed to any enum-type
2169 if (expr_type.BuiltinType == BuiltinTypeSpec.Type.Enum)
2170 return new UnboxCast (expr, target_type);
2172 TypeSpec real_target = target_type.IsEnum ? EnumSpec.GetUnderlyingType (target_type) : target_type;
2174 if (expr_type == real_target)
2175 return EmptyCast.Create (expr, target_type);
2177 Constant c = expr as Constant;
2179 c = c.TryReduce (ec, real_target);
2183 ne = ImplicitNumericConversion (expr, real_target);
2185 return EmptyCast.Create (ne, target_type);
2187 ne = ExplicitNumericConversion (ec, expr, real_target);
2189 return EmptyCast.Create (ne, target_type);
2192 // LAMESPEC: IntPtr and UIntPtr conversion to any Enum is allowed
2194 if (expr_type.BuiltinType == BuiltinTypeSpec.Type.IntPtr || expr_type.BuiltinType == BuiltinTypeSpec.Type.UIntPtr) {
2195 ne = ExplicitUserConversion (ec, expr, real_target, loc);
2197 return ExplicitConversionCore (ec, ne, target_type, loc);
2201 ne = ExplicitNumericConversion (ec, expr, target_type);
2207 // Skip the ExplicitReferenceConversion because we can not convert
2208 // from Null to a ValueType, and ExplicitReference wont check against
2209 // null literal explicitly
2211 if (expr_type != InternalType.NullLiteral) {
2212 ne = ExplicitReferenceConversion (expr, expr_type, target_type);
2218 ne = ExplicitUnsafe (expr, target_type);
2226 public static Expression ExplicitUnsafe (Expression expr, TypeSpec target_type)
2228 TypeSpec expr_type = expr.Type;
2230 if (target_type.IsPointer){
2231 if (expr_type.IsPointer)
2232 return EmptyCast.Create (expr, target_type);
2234 switch (expr_type.BuiltinType) {
2235 case BuiltinTypeSpec.Type.SByte:
2236 case BuiltinTypeSpec.Type.Short:
2237 case BuiltinTypeSpec.Type.Int:
2238 return new OpcodeCast (expr, target_type, OpCodes.Conv_I);
2240 case BuiltinTypeSpec.Type.UShort:
2241 case BuiltinTypeSpec.Type.UInt:
2242 case BuiltinTypeSpec.Type.Byte:
2243 return new OpcodeCast (expr, target_type, OpCodes.Conv_U);
2245 case BuiltinTypeSpec.Type.Long:
2246 return new ConvCast (expr, target_type, ConvCast.Mode.I8_I);
2248 case BuiltinTypeSpec.Type.ULong:
2249 return new ConvCast (expr, target_type, ConvCast.Mode.U8_I);
2253 if (expr_type.IsPointer){
2254 switch (target_type.BuiltinType) {
2255 case BuiltinTypeSpec.Type.SByte:
2256 return new OpcodeCast (expr, target_type, OpCodes.Conv_I1);
2257 case BuiltinTypeSpec.Type.Byte:
2258 return new OpcodeCast (expr, target_type, OpCodes.Conv_U1);
2259 case BuiltinTypeSpec.Type.Short:
2260 return new OpcodeCast (expr, target_type, OpCodes.Conv_I2);
2261 case BuiltinTypeSpec.Type.UShort:
2262 return new OpcodeCast (expr, target_type, OpCodes.Conv_U2);
2263 case BuiltinTypeSpec.Type.Int:
2264 return new OpcodeCast (expr, target_type, OpCodes.Conv_I4);
2265 case BuiltinTypeSpec.Type.UInt:
2266 return new OpcodeCast (expr, target_type, OpCodes.Conv_U4);
2267 case BuiltinTypeSpec.Type.Long:
2268 return new ConvCast (expr, target_type, ConvCast.Mode.I_I8);
2269 case BuiltinTypeSpec.Type.ULong:
2270 return new OpcodeCast (expr, target_type, OpCodes.Conv_U8);
2277 /// Same as ExplicitConversion, only it doesn't include user defined conversions
2279 static public Expression ExplicitConversionStandard (ResolveContext ec, Expression expr,
2280 TypeSpec target_type, Location l)
2282 int errors = ec.Report.Errors;
2283 Expression ne = ImplicitConversionStandard (ec, expr, target_type, l);
2284 if (ec.Report.Errors > errors)
2290 ne = ExplicitNumericConversion (ec, expr, target_type);
2294 ne = ExplicitReferenceConversion (expr, expr.Type, target_type);
2298 if (ec.IsUnsafe && expr.Type.IsPointer && target_type.IsPointer && ((PointerContainer)expr.Type).Element.Kind == MemberKind.Void)
2299 return EmptyCast.Create (expr, target_type);
2301 expr.Error_ValueCannotBeConverted (ec, target_type, true);
2306 /// Performs an explicit conversion of the expression `expr' whose
2307 /// type is expr.Type to `target_type'.
2309 static public Expression ExplicitConversion (ResolveContext ec, Expression expr,
2310 TypeSpec target_type, Location loc)
2312 Expression e = ExplicitConversionCore (ec, expr, target_type, loc);
2315 // Don't eliminate explicit precission casts
2318 if (target_type.BuiltinType == BuiltinTypeSpec.Type.Float)
2319 return new OpcodeCast (expr, target_type, OpCodes.Conv_R4);
2321 if (target_type.BuiltinType == BuiltinTypeSpec.Type.Double)
2322 return new OpcodeCast (expr, target_type, OpCodes.Conv_R8);
2328 TypeSpec expr_type = expr.Type;
2329 if (target_type.IsNullableType) {
2332 if (expr_type.IsNullableType) {
2333 target = Nullable.NullableInfo.GetUnderlyingType (target_type);
2334 Expression unwrap = Nullable.Unwrap.Create (expr);
2335 e = ExplicitConversion (ec, unwrap, target, expr.Location);
2339 return new Nullable.LiftedConversion (e, unwrap, target_type).Resolve (ec);
2341 if (expr_type.BuiltinType == BuiltinTypeSpec.Type.Object) {
2342 return new UnboxCast (expr, target_type);
2345 target = TypeManager.GetTypeArguments (target_type) [0];
2346 e = ExplicitConversionCore (ec, expr, target, loc);
2348 return TypeSpec.IsReferenceType (expr.Type) ? new UnboxCast (expr, target_type) : Nullable.Wrap.Create (e, target_type);
2349 } else if (expr_type.IsNullableType) {
2350 e = ImplicitBoxingConversion (expr, Nullable.NullableInfo.GetUnderlyingType (expr_type), target_type);
2354 e = Nullable.Unwrap.Create (expr, false);
2355 e = ExplicitConversionCore (ec, e, target_type, loc);
2357 return EmptyCast.Create (e, target_type);
2360 e = ExplicitUserConversion (ec, expr, target_type, loc);
2365 expr.Error_ValueCannotBeConverted (ec, target_type, true);