2 // conversion.cs: various routines for implementing conversions.
5 // Miguel de Icaza (miguel@ximian.com)
6 // Ravi Pratap (ravi@ximian.com)
8 // (C) 2001, 2002, 2003 Ximian, Inc.
11 namespace Mono.CSharp {
13 using System.Collections;
14 using System.Diagnostics;
15 using System.Reflection;
16 using System.Reflection.Emit;
19 // A container class for all the conversion operations
21 public class Convert {
23 // This is used to prettify the code: a null argument is allowed
24 // for ImplicitStandardConversion as long as it is known that
25 // no anonymous method will play a role.
27 // FIXME: renamed from `const' to `static' to allow bootstraping from older
28 // versions of the compiler that could not cope with this construct.
30 public static EmitContext ConstantEC = null;
32 static public void Error_CannotConvertType (Location loc, Type source, Type target)
34 Report.Error (30, loc, "Cannot convert type '" +
35 TypeManager.CSharpName (source) + "' to '" +
36 TypeManager.CSharpName (target) + "'");
39 static Expression TypeParameter_to_Null (Expression expr, Type target_type,
42 if (!TypeParameter_to_Null (target_type)) {
43 Report.Error (403, loc, "Cannot convert null to the type " +
44 "parameter `{0}' becaues it could be a value " +
45 "type. Consider using `default ({0})' instead.",
50 return new NullCast (expr, target_type);
53 static bool TypeParameter_to_Null (Type target_type)
55 GenericConstraints gc = TypeManager.GetTypeParameterConstraints (target_type);
59 if (gc.HasReferenceTypeConstraint)
61 if (gc.HasClassConstraint && !TypeManager.IsValueType (gc.ClassConstraint))
67 static Type TypeParam_EffectiveBaseType (EmitContext ec, GenericConstraints gc)
69 ArrayList list = new ArrayList ();
70 list.Add (gc.EffectiveBaseClass);
71 foreach (Type t in gc.InterfaceConstraints) {
72 if (!t.IsGenericParameter)
75 GenericConstraints new_gc = TypeManager.GetTypeParameterConstraints (t);
77 list.Add (TypeParam_EffectiveBaseType (ec, new_gc));
79 return FindMostEncompassedType (ec, list);
82 static Expression ImplicitTypeParameterConversion (EmitContext ec, Expression expr,
85 Type expr_type = expr.Type;
87 GenericConstraints gc = TypeManager.GetTypeParameterConstraints (expr_type);
90 if (target_type == TypeManager.object_type)
91 return new BoxedCast (expr, target_type);
96 // We're converting from a type parameter which is known to be a reference type.
97 Type base_type = TypeParam_EffectiveBaseType (ec, gc);
99 if (TypeManager.IsSubclassOf (base_type, target_type))
100 return new BoxedCast (expr, target_type);
102 if (target_type.IsInterface) {
103 if (TypeManager.ImplementsInterface (base_type, target_type))
104 return new BoxedCast (expr, target_type);
106 foreach (Type t in gc.InterfaceConstraints) {
107 if (TypeManager.IsSubclassOf (t, target_type))
108 return new BoxedCast (expr, target_type);
112 foreach (Type t in gc.InterfaceConstraints) {
113 if (!t.IsGenericParameter)
115 if (TypeManager.IsSubclassOf (t, target_type))
116 return new BoxedCast (expr, target_type);
122 static EmptyExpression MyEmptyExpr;
123 static public Expression ImplicitReferenceConversion (EmitContext ec, Expression expr, Type target_type)
125 Type expr_type = expr.Type;
127 if (expr_type == null && expr.eclass == ExprClass.MethodGroup){
128 // if we are a method group, emit a warning
133 if (expr_type == TypeManager.void_type)
136 if (expr_type.IsGenericParameter)
137 return ImplicitTypeParameterConversion (ec, expr, target_type);
140 // notice that it is possible to write "ValueType v = 1", the ValueType here
141 // is an abstract class, and not really a value type, so we apply the same rules.
143 if (target_type == TypeManager.object_type) {
145 // A pointer type cannot be converted to object
147 if (expr_type.IsPointer)
150 if (TypeManager.IsValueType (expr_type))
151 return new BoxedCast (expr, target_type);
152 if (expr_type.IsClass || expr_type.IsInterface || expr_type == TypeManager.enum_type){
153 if (expr_type == TypeManager.anonymous_method_type)
155 return new EmptyCast (expr, target_type);
159 } else if (target_type == TypeManager.value_type) {
160 if (TypeManager.IsValueType (expr_type))
161 return new BoxedCast (expr, target_type);
162 if (expr_type == TypeManager.null_type)
163 return new NullCast (expr, target_type);
166 } else if (TypeManager.IsSubclassOf (expr_type, target_type)) {
168 // Special case: enumeration to System.Enum.
169 // System.Enum is not a value type, it is a class, so we need
170 // a boxing conversion
172 if (expr_type.IsEnum || expr_type.IsGenericParameter)
173 return new BoxedCast (expr, target_type);
175 return new EmptyCast (expr, target_type);
178 // This code is kind of mirrored inside ImplicitStandardConversionExists
179 // with the small distinction that we only probe there
181 // Always ensure that the code here and there is in sync
183 // from the null type to any reference-type.
184 if (expr_type == TypeManager.null_type){
185 if (target_type.IsPointer)
186 return new EmptyCast (NullPointer.Null, target_type);
188 if (!target_type.IsValueType)
189 return new NullCast (expr, target_type);
192 // from any class-type S to any interface-type T.
193 if (target_type.IsInterface) {
194 if (target_type != TypeManager.iconvertible_type &&
195 expr_type.IsValueType && (expr is Constant) &&
196 !(expr is IntLiteral || expr is BoolLiteral ||
197 expr is FloatLiteral || expr is DoubleLiteral ||
198 expr is LongLiteral || expr is CharLiteral ||
199 expr is StringLiteral || expr is DecimalLiteral ||
200 expr is UIntLiteral || expr is ULongLiteral)) {
204 if (TypeManager.ImplementsInterface (expr_type, target_type)){
205 if (expr_type.IsGenericParameter || TypeManager.IsValueType (expr_type))
206 return new BoxedCast (expr, target_type);
208 return new EmptyCast (expr, target_type);
212 // from any interface type S to interface-type T.
213 if (expr_type.IsInterface && target_type.IsInterface) {
214 if (TypeManager.ImplementsInterface (expr_type, target_type))
215 return new EmptyCast (expr, target_type);
220 // from an array-type S to an array-type of type T
221 if (expr_type.IsArray && target_type.IsArray) {
222 if (expr_type.GetArrayRank () == target_type.GetArrayRank ()) {
224 Type expr_element_type = TypeManager.GetElementType (expr_type);
226 if (MyEmptyExpr == null)
227 MyEmptyExpr = new EmptyExpression ();
229 MyEmptyExpr.SetType (expr_element_type);
230 Type target_element_type = TypeManager.GetElementType (target_type);
232 if (!expr_element_type.IsValueType && !target_element_type.IsValueType)
233 if (ImplicitStandardConversionExists (ConstantEC, MyEmptyExpr,
234 target_element_type))
235 return new EmptyCast (expr, target_type);
239 // from an array-type to System.Array
240 if (expr_type.IsArray && target_type == TypeManager.array_type)
241 return new EmptyCast (expr, target_type);
243 // from an array-type of type T to IEnumerable<T>
244 if (expr_type.IsArray && TypeManager.IsIEnumerable (expr_type, target_type))
245 return new EmptyCast (expr, target_type);
247 // from any delegate type to System.Delegate
248 if ((expr_type == TypeManager.delegate_type || TypeManager.IsDelegateType (expr_type)) &&
249 target_type == TypeManager.delegate_type)
250 return new EmptyCast (expr, target_type);
252 // from any array-type or delegate type into System.ICloneable.
253 if (expr_type.IsArray ||
254 expr_type == TypeManager.delegate_type || TypeManager.IsDelegateType (expr_type))
255 if (target_type == TypeManager.icloneable_type)
256 return new EmptyCast (expr, target_type);
258 // from a generic type definition to a generic instance.
259 if (TypeManager.IsEqual (expr_type, target_type))
260 return new EmptyCast (expr, target_type);
266 // Tests whether an implicit reference conversion exists between expr_type
269 public static bool ImplicitReferenceConversionExists (EmitContext ec, Expression expr, Type target_type)
271 if (target_type.IsValueType)
274 Type expr_type = expr.Type;
276 if (expr_type.IsGenericParameter)
277 return ImplicitTypeParameterConversion (ec, expr, target_type) != null;
280 // This is the boxed case.
282 if (target_type == TypeManager.object_type) {
283 if (expr_type.IsClass || TypeManager.IsValueType (expr_type) ||
284 expr_type.IsInterface || expr_type == TypeManager.enum_type)
285 if (target_type != TypeManager.anonymous_method_type)
289 } else if (TypeManager.IsSubclassOf (expr_type, target_type))
292 // Please remember that all code below actually comes
293 // from ImplicitReferenceConversion so make sure code remains in sync
295 // from any class-type S to any interface-type T.
296 if (target_type.IsInterface) {
297 if (target_type != TypeManager.iconvertible_type &&
298 expr_type.IsValueType && (expr is Constant) &&
299 !(expr is IntLiteral || expr is BoolLiteral ||
300 expr is FloatLiteral || expr is DoubleLiteral ||
301 expr is LongLiteral || expr is CharLiteral ||
302 expr is StringLiteral || expr is DecimalLiteral ||
303 expr is UIntLiteral || expr is ULongLiteral)) {
307 if (TypeManager.ImplementsInterface (expr_type, target_type))
311 // from any interface type S to interface-type T.
312 if (expr_type.IsInterface && target_type.IsInterface)
313 if (TypeManager.ImplementsInterface (expr_type, target_type))
316 // from an array-type S to an array-type of type T
317 if (expr_type.IsArray && target_type.IsArray) {
318 if (expr_type.GetArrayRank () == target_type.GetArrayRank ()) {
320 Type expr_element_type = expr_type.GetElementType ();
322 if (MyEmptyExpr == null)
323 MyEmptyExpr = new EmptyExpression ();
325 MyEmptyExpr.SetType (expr_element_type);
326 Type target_element_type = TypeManager.GetElementType (target_type);
328 if (!expr_element_type.IsValueType && !target_element_type.IsValueType)
329 if (ImplicitStandardConversionExists (ConstantEC, MyEmptyExpr,
330 target_element_type))
335 // from an array-type to System.Array
336 if (expr_type.IsArray && (target_type == TypeManager.array_type))
339 // from an array-type of type T to IEnumerable<T>
340 if (expr_type.IsArray && TypeManager.IsIEnumerable (expr_type, target_type))
343 // from any delegate type to System.Delegate
344 if ((expr_type == TypeManager.delegate_type || TypeManager.IsDelegateType (expr_type)) &&
345 target_type == TypeManager.delegate_type)
346 if (target_type.IsAssignableFrom (expr_type))
349 // from any array-type or delegate type into System.ICloneable.
350 if (expr_type.IsArray ||
351 expr_type == TypeManager.delegate_type || TypeManager.IsDelegateType (expr_type))
352 if (target_type == TypeManager.icloneable_type)
355 // from the null type to any reference-type.
356 if (expr_type == TypeManager.null_type){
357 if (target_type.IsPointer)
360 if (!target_type.IsValueType)
364 // from a generic type definition to a generic instance.
365 if (TypeManager.IsEqual (expr_type, target_type))
372 /// Implicit Numeric Conversions.
374 /// expr is the expression to convert, returns a new expression of type
375 /// target_type or null if an implicit conversion is not possible.
377 static public Expression ImplicitNumericConversion (EmitContext ec, Expression expr,
378 Type target_type, Location loc)
380 Type expr_type = expr.Type;
383 // Attempt to do the implicit constant expression conversions
385 if (expr is Constant){
386 if (expr is IntConstant){
389 e = TryImplicitIntConversion (target_type, (IntConstant) expr);
393 } else if (expr is LongConstant && target_type == TypeManager.uint64_type){
395 // Try the implicit constant expression conversion
396 // from long to ulong, instead of a nice routine,
399 long v = ((LongConstant) expr).Value;
401 return new ULongConstant ((ulong) v, expr.Location);
405 Type real_target_type = target_type;
407 if (expr_type == TypeManager.sbyte_type){
409 // From sbyte to short, int, long, float, double, decimal
411 if (real_target_type == TypeManager.int32_type)
412 return new OpcodeCast (expr, target_type, OpCodes.Conv_I4);
413 if (real_target_type == TypeManager.int64_type)
414 return new OpcodeCast (expr, target_type, OpCodes.Conv_I8);
415 if (real_target_type == TypeManager.double_type)
416 return new OpcodeCast (expr, target_type, OpCodes.Conv_R8);
417 if (real_target_type == TypeManager.float_type)
418 return new OpcodeCast (expr, target_type, OpCodes.Conv_R4);
419 if (real_target_type == TypeManager.short_type)
420 return new OpcodeCast (expr, target_type, OpCodes.Conv_I2);
421 if (real_target_type == TypeManager.decimal_type)
422 return new CastToDecimal (ec, expr);
423 } else if (expr_type == TypeManager.byte_type){
425 // From byte to short, ushort, int, uint, long, ulong, float, double, decimal
427 if ((real_target_type == TypeManager.short_type) ||
428 (real_target_type == TypeManager.ushort_type) ||
429 (real_target_type == TypeManager.int32_type) ||
430 (real_target_type == TypeManager.uint32_type))
431 return new EmptyCast (expr, target_type);
433 if (real_target_type == TypeManager.uint64_type)
434 return new OpcodeCast (expr, target_type, OpCodes.Conv_U8);
435 if (real_target_type == TypeManager.int64_type)
436 return new OpcodeCast (expr, target_type, OpCodes.Conv_I8);
437 if (real_target_type == TypeManager.float_type)
438 return new OpcodeCast (expr, target_type, OpCodes.Conv_R4);
439 if (real_target_type == TypeManager.double_type)
440 return new OpcodeCast (expr, target_type, OpCodes.Conv_R8);
441 if (real_target_type == TypeManager.decimal_type)
442 return new CastToDecimal (ec, expr);
444 } else if (expr_type == TypeManager.short_type){
446 // From short to int, long, float, double, decimal
448 if (real_target_type == TypeManager.int32_type)
449 return new EmptyCast (expr, target_type);
450 if (real_target_type == TypeManager.int64_type)
451 return new OpcodeCast (expr, target_type, OpCodes.Conv_I8);
452 if (real_target_type == TypeManager.double_type)
453 return new OpcodeCast (expr, target_type, OpCodes.Conv_R8);
454 if (real_target_type == TypeManager.float_type)
455 return new OpcodeCast (expr, target_type, OpCodes.Conv_R4);
456 if (real_target_type == TypeManager.decimal_type)
457 return new CastToDecimal (ec, expr);
459 } else if (expr_type == TypeManager.ushort_type){
461 // From ushort to int, uint, long, ulong, float, double, decimal
463 if (real_target_type == TypeManager.uint32_type)
464 return new EmptyCast (expr, target_type);
466 if (real_target_type == TypeManager.uint64_type)
467 return new OpcodeCast (expr, target_type, OpCodes.Conv_U8);
468 if (real_target_type == TypeManager.int32_type)
469 return new OpcodeCast (expr, target_type, OpCodes.Conv_I4);
470 if (real_target_type == TypeManager.int64_type)
471 return new OpcodeCast (expr, target_type, OpCodes.Conv_I8);
472 if (real_target_type == TypeManager.double_type)
473 return new OpcodeCast (expr, target_type, OpCodes.Conv_R8);
474 if (real_target_type == TypeManager.float_type)
475 return new OpcodeCast (expr, target_type, OpCodes.Conv_R4);
476 if (real_target_type == TypeManager.decimal_type)
477 return new CastToDecimal (ec, expr);
478 } else if (expr_type == TypeManager.int32_type){
480 // From int to long, float, double, decimal
482 if (real_target_type == TypeManager.int64_type)
483 return new OpcodeCast (expr, target_type, OpCodes.Conv_I8);
484 if (real_target_type == TypeManager.double_type)
485 return new OpcodeCast (expr, target_type, OpCodes.Conv_R8);
486 if (real_target_type == TypeManager.float_type)
487 return new OpcodeCast (expr, target_type, OpCodes.Conv_R4);
488 if (real_target_type == TypeManager.decimal_type)
489 return new CastToDecimal (ec, expr);
490 } else if (expr_type == TypeManager.uint32_type){
492 // From uint to long, ulong, float, double, decimal
494 if (real_target_type == TypeManager.int64_type)
495 return new OpcodeCast (expr, target_type, OpCodes.Conv_U8);
496 if (real_target_type == TypeManager.uint64_type)
497 return new OpcodeCast (expr, target_type, OpCodes.Conv_U8);
498 if (real_target_type == TypeManager.double_type)
499 return new OpcodeCast (expr, target_type, OpCodes.Conv_R_Un,
501 if (real_target_type == TypeManager.float_type)
502 return new OpcodeCast (expr, target_type, OpCodes.Conv_R_Un,
504 if (real_target_type == TypeManager.decimal_type)
505 return new CastToDecimal (ec, expr);
506 } else if (expr_type == TypeManager.int64_type){
508 // From long/ulong to float, double
510 if (real_target_type == TypeManager.double_type)
511 return new OpcodeCast (expr, target_type, OpCodes.Conv_R8);
512 if (real_target_type == TypeManager.float_type)
513 return new OpcodeCast (expr, target_type, OpCodes.Conv_R4);
514 if (real_target_type == TypeManager.decimal_type)
515 return new CastToDecimal (ec, expr);
516 } else if (expr_type == TypeManager.uint64_type){
518 // From ulong to float, double
520 if (real_target_type == TypeManager.double_type)
521 return new OpcodeCast (expr, target_type, OpCodes.Conv_R_Un,
523 if (real_target_type == TypeManager.float_type)
524 return new OpcodeCast (expr, target_type, OpCodes.Conv_R_Un,
526 if (real_target_type == TypeManager.decimal_type)
527 return new CastToDecimal (ec, expr);
528 } else if (expr_type == TypeManager.char_type){
530 // From char to ushort, int, uint, long, ulong, float, double, decimal
532 if ((real_target_type == TypeManager.ushort_type) ||
533 (real_target_type == TypeManager.int32_type) ||
534 (real_target_type == TypeManager.uint32_type))
535 return new EmptyCast (expr, target_type);
536 if (real_target_type == TypeManager.uint64_type)
537 return new OpcodeCast (expr, target_type, OpCodes.Conv_U8);
538 if (real_target_type == TypeManager.int64_type)
539 return new OpcodeCast (expr, target_type, OpCodes.Conv_I8);
540 if (real_target_type == TypeManager.float_type)
541 return new OpcodeCast (expr, target_type, OpCodes.Conv_R4);
542 if (real_target_type == TypeManager.double_type)
543 return new OpcodeCast (expr, target_type, OpCodes.Conv_R8);
544 if (real_target_type == TypeManager.decimal_type)
545 return new CastToDecimal (ec, expr);
546 } else if (expr_type == TypeManager.float_type){
550 if (real_target_type == TypeManager.double_type)
551 return new OpcodeCast (expr, target_type, OpCodes.Conv_R8);
559 /// Same as ImplicitStandardConversionExists except that it also looks at
560 /// implicit user defined conversions - needed for overload resolution
562 public static bool ImplicitConversionExists (EmitContext ec, Expression expr, Type target_type)
564 if (expr is NullLiteral) {
565 if (target_type.IsGenericParameter)
566 return TypeParameter_to_Null (target_type);
568 if (TypeManager.IsNullableType (target_type))
572 if (ImplicitStandardConversionExists (ec, expr, target_type))
575 Expression dummy = ImplicitUserConversion (ec, expr, target_type, Location.Null);
583 public static bool ImplicitUserConversionExists (EmitContext ec, Type source, Type target)
585 Expression dummy = ImplicitUserConversion (
586 ec, new EmptyExpression (source), target, Location.Null);
587 return dummy != null;
591 /// Determines if a standard implicit conversion exists from
592 /// expr_type to target_type
594 /// ec should point to a real EmitContext if expr.Type is TypeManager.anonymous_method_type.
596 public static bool ImplicitStandardConversionExists (EmitContext ec, Expression expr, Type target_type)
598 Type expr_type = expr.Type;
600 if (expr_type == TypeManager.void_type)
603 //Console.WriteLine ("Expr is {0}", expr);
604 //Console.WriteLine ("{0} -> {1} ?", expr_type, target_type);
605 if (expr_type.Equals (target_type))
609 // First numeric conversions
611 if (expr_type == TypeManager.sbyte_type){
613 // From sbyte to short, int, long, float, double, decimal
615 if ((target_type == TypeManager.int32_type) ||
616 (target_type == TypeManager.int64_type) ||
617 (target_type == TypeManager.double_type) ||
618 (target_type == TypeManager.float_type) ||
619 (target_type == TypeManager.short_type) ||
620 (target_type == TypeManager.decimal_type))
623 } else if (expr_type == TypeManager.byte_type){
625 // From byte to short, ushort, int, uint, long, ulong, float, double, decimal
627 if ((target_type == TypeManager.short_type) ||
628 (target_type == TypeManager.ushort_type) ||
629 (target_type == TypeManager.int32_type) ||
630 (target_type == TypeManager.uint32_type) ||
631 (target_type == TypeManager.uint64_type) ||
632 (target_type == TypeManager.int64_type) ||
633 (target_type == TypeManager.float_type) ||
634 (target_type == TypeManager.double_type) ||
635 (target_type == TypeManager.decimal_type))
638 } else if (expr_type == TypeManager.short_type){
640 // From short to int, long, double, float, decimal
642 if ((target_type == TypeManager.int32_type) ||
643 (target_type == TypeManager.int64_type) ||
644 (target_type == TypeManager.double_type) ||
645 (target_type == TypeManager.float_type) ||
646 (target_type == TypeManager.decimal_type))
649 } else if (expr_type == TypeManager.ushort_type){
651 // From ushort to int, uint, long, ulong, double, float, decimal
653 if ((target_type == TypeManager.uint32_type) ||
654 (target_type == TypeManager.uint64_type) ||
655 (target_type == TypeManager.int32_type) ||
656 (target_type == TypeManager.int64_type) ||
657 (target_type == TypeManager.double_type) ||
658 (target_type == TypeManager.float_type) ||
659 (target_type == TypeManager.decimal_type))
662 } else if (expr_type == TypeManager.int32_type){
664 // From int to long, double, float, decimal
666 if ((target_type == TypeManager.int64_type) ||
667 (target_type == TypeManager.double_type) ||
668 (target_type == TypeManager.float_type) ||
669 (target_type == TypeManager.decimal_type))
672 } else if (expr_type == TypeManager.uint32_type){
674 // From uint to long, ulong, double, float, decimal
676 if ((target_type == TypeManager.int64_type) ||
677 (target_type == TypeManager.uint64_type) ||
678 (target_type == TypeManager.double_type) ||
679 (target_type == TypeManager.float_type) ||
680 (target_type == TypeManager.decimal_type))
683 } else if ((expr_type == TypeManager.uint64_type) ||
684 (expr_type == TypeManager.int64_type)) {
686 // From long/ulong to double, float, decimal
688 if ((target_type == TypeManager.double_type) ||
689 (target_type == TypeManager.float_type) ||
690 (target_type == TypeManager.decimal_type))
693 } else if (expr_type == TypeManager.char_type){
695 // From char to ushort, int, uint, ulong, long, float, double, decimal
697 if ((target_type == TypeManager.ushort_type) ||
698 (target_type == TypeManager.int32_type) ||
699 (target_type == TypeManager.uint32_type) ||
700 (target_type == TypeManager.uint64_type) ||
701 (target_type == TypeManager.int64_type) ||
702 (target_type == TypeManager.float_type) ||
703 (target_type == TypeManager.double_type) ||
704 (target_type == TypeManager.decimal_type))
707 } else if (expr_type == TypeManager.float_type){
711 if (target_type == TypeManager.double_type)
715 if (expr.eclass == ExprClass.MethodGroup){
716 if (TypeManager.IsDelegateType (target_type) && RootContext.Version != LanguageVersion.ISO_1){
717 MethodGroupExpr mg = expr as MethodGroupExpr;
720 // This should not happen frequently, so we can create an object
721 // to test compatibility
723 Expression c = ImplicitDelegateCreation.Create (
724 ec, mg, target_type, true, Location.Null);
730 if (ImplicitReferenceConversionExists (ec, expr, target_type))
734 // Implicit Constant Expression Conversions
736 if (expr is IntConstant){
737 int value = ((IntConstant) expr).Value;
739 if (target_type == TypeManager.sbyte_type){
740 if (value >= SByte.MinValue && value <= SByte.MaxValue)
742 } else if (target_type == TypeManager.byte_type){
743 if (value >= 0 && value <= Byte.MaxValue)
745 } else if (target_type == TypeManager.short_type){
746 if (value >= Int16.MinValue && value <= Int16.MaxValue)
748 } else if (target_type == TypeManager.ushort_type){
749 if (value >= UInt16.MinValue && value <= UInt16.MaxValue)
751 } else if (target_type == TypeManager.uint32_type){
754 } else if (target_type == TypeManager.uint64_type){
756 // we can optimize this case: a positive int32
757 // always fits on a uint64. But we need an opcode
764 if (value == 0 && expr is IntLiteral && TypeManager.IsEnumType (target_type))
768 if (expr is LongConstant && target_type == TypeManager.uint64_type){
770 // Try the implicit constant expression conversion
771 // from long to ulong, instead of a nice routine,
774 long v = ((LongConstant) expr).Value;
779 if ((target_type == TypeManager.enum_type ||
780 target_type.IsSubclassOf (TypeManager.enum_type)) &&
782 IntLiteral i = (IntLiteral) expr;
789 // If `expr_type' implements `target_type' (which is an iface)
790 // see TryImplicitIntConversion
792 if (target_type.IsInterface && target_type.IsAssignableFrom (expr_type))
795 if (target_type == TypeManager.void_ptr_type && expr_type.IsPointer)
798 if (TypeManager.IsNullableType (expr_type) && TypeManager.IsNullableType (target_type))
801 if (expr_type == TypeManager.anonymous_method_type){
802 if (!TypeManager.IsDelegateType (target_type))
805 AnonymousMethod am = (AnonymousMethod) expr;
807 Expression conv = am.Compatible (ec, target_type, true);
816 /// Finds "most encompassed type" according to the spec (13.4.2)
817 /// amongst the methods in the MethodGroupExpr
819 static Type FindMostEncompassedType (EmitContext ec, ArrayList types)
823 if (types.Count == 0)
826 if (types.Count == 1)
827 return (Type) types [0];
829 EmptyExpression expr = EmptyExpression.Grab ();
831 foreach (Type t in types) {
838 if (ImplicitStandardConversionExists (ec, expr, best))
843 foreach (Type t in types) {
846 if (!ImplicitStandardConversionExists (ec, expr, t)) {
852 EmptyExpression.Release (expr);
858 /// Finds "most encompassing type" according to the spec (13.4.2)
859 /// amongst the types in the given set
861 static Type FindMostEncompassingType (EmitContext ec, ArrayList types)
865 if (types.Count == 0)
868 if (types.Count == 1)
869 return (Type) types [0];
871 EmptyExpression expr = EmptyExpression.Grab ();
873 foreach (Type t in types) {
880 if (ImplicitStandardConversionExists (ec, expr, t))
884 foreach (Type t in types) {
888 if (!ImplicitStandardConversionExists (ec, expr, best)) {
894 EmptyExpression.Release (expr);
900 /// Finds the most specific source Sx according to the rules of the spec (13.4.4)
901 /// by making use of FindMostEncomp* methods. Applies the correct rules separately
902 /// for explicit and implicit conversion operators.
904 static public Type FindMostSpecificSource (EmitContext ec, IList list,
905 Expression source, bool apply_explicit_conv_rules,
908 ArrayList src_types_set = new ArrayList ();
911 // If any operator converts from S then Sx = S
913 Type source_type = source.Type;
914 foreach (MethodBase mb in list){
915 ParameterData pd = TypeManager.GetParameterData (mb);
916 Type param_type = pd.ParameterType (0);
918 if (param_type == source_type)
921 src_types_set.Add (param_type);
925 // Explicit Conv rules
927 if (apply_explicit_conv_rules) {
928 ArrayList candidate_set = new ArrayList ();
930 foreach (Type param_type in src_types_set){
931 if (ImplicitStandardConversionExists (ec, source, param_type))
932 candidate_set.Add (param_type);
935 if (candidate_set.Count != 0)
936 return FindMostEncompassedType (ec, candidate_set);
942 if (apply_explicit_conv_rules)
943 return FindMostEncompassingType (ec, src_types_set);
945 return FindMostEncompassedType (ec, src_types_set);
949 /// Finds the most specific target Tx according to section 13.4.4
951 static public Type FindMostSpecificTarget (EmitContext ec, IList list,
952 Type target, bool apply_explicit_conv_rules,
955 ArrayList tgt_types_set = new ArrayList ();
958 // If any operator converts to T then Tx = T
960 foreach (MethodInfo mi in list){
961 Type ret_type = mi.ReturnType;
962 if (ret_type == target)
965 tgt_types_set.Add (ret_type);
969 // Explicit conv rules
971 if (apply_explicit_conv_rules) {
972 ArrayList candidate_set = new ArrayList ();
974 EmptyExpression expr = EmptyExpression.Grab ();
976 foreach (Type ret_type in tgt_types_set){
977 expr.SetType (ret_type);
979 if (ImplicitStandardConversionExists (ec, expr, target))
980 candidate_set.Add (ret_type);
983 EmptyExpression.Release (expr);
985 if (candidate_set.Count != 0)
986 return FindMostEncompassingType (ec, candidate_set);
990 // Okay, final case !
992 if (apply_explicit_conv_rules)
993 return FindMostEncompassedType (ec, tgt_types_set);
995 return FindMostEncompassingType (ec, tgt_types_set);
999 /// User-defined Implicit conversions
1001 static public Expression ImplicitUserConversion (EmitContext ec, Expression source,
1002 Type target, Location loc)
1004 return UserDefinedConversion (ec, source, target, loc, false);
1008 /// User-defined Explicit conversions
1010 static public Expression ExplicitUserConversion (EmitContext ec, Expression source,
1011 Type target, Location loc)
1013 return UserDefinedConversion (ec, source, target, loc, true);
1016 static void AddConversionOperators (EmitContext ec, ArrayList list,
1017 Expression source, Type target_type,
1018 bool look_for_explicit,
1024 Type source_type = source.Type;
1025 EmptyExpression expr = EmptyExpression.Grab ();
1026 foreach (MethodInfo m in mg.Methods) {
1027 ParameterData pd = TypeManager.GetParameterData (m);
1028 Type return_type = m.ReturnType;
1029 Type arg_type = pd.ParameterType (0);
1031 if (source_type != arg_type) {
1032 if (!ImplicitStandardConversionExists (ec, source, arg_type)) {
1033 if (!look_for_explicit)
1035 expr.SetType (arg_type);
1036 if (!ImplicitStandardConversionExists (ec, expr, source_type))
1041 if (target_type != return_type) {
1042 expr.SetType (return_type);
1043 if (!ImplicitStandardConversionExists (ec, expr, target_type)) {
1044 if (!look_for_explicit)
1046 expr.SetType (target_type);
1047 if (!ImplicitStandardConversionExists (ec, expr, return_type))
1055 EmptyExpression.Release (expr);
1059 /// Computes the list of the user-defined conversion
1060 /// operators from source_type to target_type. `look_for_explicit'
1061 /// controls whether we should also include the list of explicit
1064 static IList GetConversionOperators (EmitContext ec,
1065 Expression source, Type target_type,
1066 Location loc, bool look_for_explicit)
1068 ArrayList ret = new ArrayList (4);
1070 Type source_type = source.Type;
1072 if (source_type != TypeManager.decimal_type) {
1073 AddConversionOperators (ec, ret, source, target_type, look_for_explicit,
1074 Expression.MethodLookup (
1075 ec, source_type, "op_Implicit", loc) as MethodGroupExpr);
1076 if (look_for_explicit) {
1077 AddConversionOperators (ec, ret, source, target_type, look_for_explicit,
1078 Expression.MethodLookup (
1079 ec, source_type, "op_Explicit", loc) as MethodGroupExpr);
1083 if (target_type != TypeManager.decimal_type) {
1084 AddConversionOperators (ec, ret, source, target_type, look_for_explicit,
1085 Expression.MethodLookup (
1086 ec, target_type, "op_Implicit", loc) as MethodGroupExpr);
1087 if (look_for_explicit) {
1088 AddConversionOperators (ec, ret, source, target_type, look_for_explicit,
1089 Expression.MethodLookup (
1090 ec, target_type, "op_Explicit", loc) as MethodGroupExpr);
1097 static DoubleHash explicit_conv = new DoubleHash (100);
1098 static DoubleHash implicit_conv = new DoubleHash (100);
1101 /// User-defined conversions
1103 static public Expression UserDefinedConversion (EmitContext ec, Expression source,
1104 Type target, Location loc,
1105 bool look_for_explicit)
1107 Type source_type = source.Type;
1108 MethodInfo method = null;
1109 Type most_specific_source = null;
1110 Type most_specific_target = null;
1112 if (TypeManager.IsNullableType (source_type) && TypeManager.IsNullableType (target))
1113 return new Nullable.LiftedConversion (
1114 source, target, true, look_for_explicit, loc).Resolve (ec);
1117 DoubleHash hash = look_for_explicit ? explicit_conv : implicit_conv;
1119 if (!(source is Constant) && hash.Lookup (source_type, target, out o)) {
1120 method = (MethodInfo) o;
1121 if (method != null) {
1122 ParameterData pd = TypeManager.GetParameterData (method);
1123 most_specific_source = pd.ParameterType (0);
1124 most_specific_target = method.ReturnType;
1127 IList ops = GetConversionOperators (ec, source, target, loc, look_for_explicit);
1128 if (ops == null || ops.Count == 0) {
1133 most_specific_source = FindMostSpecificSource (ec, ops, source, look_for_explicit, loc);
1134 if (most_specific_source == null) {
1139 most_specific_target = FindMostSpecificTarget (ec, ops, target, look_for_explicit, loc);
1140 if (most_specific_target == null) {
1147 foreach (MethodInfo m in ops) {
1148 ParameterData pd = TypeManager.GetParameterData (m);
1150 if (pd.ParameterType (0) == most_specific_source &&
1151 m.ReturnType == most_specific_target) {
1160 if (!(source is Constant))
1161 hash.Insert (source_type, target, method);
1168 // This will do the conversion to the best match that we
1169 // found. Now we need to perform an implict standard conversion
1170 // if the best match was not the type that we were requested
1173 if (look_for_explicit)
1174 source = ExplicitConversionStandard (ec, source, most_specific_source, loc);
1176 source = ImplicitConversionStandard (ec, source, most_specific_source, loc);
1182 e = new UserCast (method, source, loc);
1183 if (e.Type != target){
1184 if (!look_for_explicit)
1185 e = ImplicitConversionStandard (ec, e, target, loc);
1187 e = ExplicitConversionStandard (ec, e, target, loc);
1194 /// Converts implicitly the resolved expression `expr' into the
1195 /// `target_type'. It returns a new expression that can be used
1196 /// in a context that expects a `target_type'.
1198 static public Expression ImplicitConversion (EmitContext ec, Expression expr,
1199 Type target_type, Location loc)
1203 if (target_type == null)
1204 throw new Exception ("Target type is null");
1206 e = ImplicitConversionStandard (ec, expr, target_type, loc);
1210 e = ImplicitUserConversion (ec, expr, target_type, loc);
1219 /// Attempts to apply the `Standard Implicit
1220 /// Conversion' rules to the expression `expr' into
1221 /// the `target_type'. It returns a new expression
1222 /// that can be used in a context that expects a
1225 /// This is different from `ImplicitConversion' in that the
1226 /// user defined implicit conversions are excluded.
1228 static public Expression ImplicitConversionStandard (EmitContext ec, Expression expr,
1229 Type target_type, Location loc)
1231 Type expr_type = expr.Type;
1234 if (expr is NullLiteral) {
1235 if (target_type.IsGenericParameter)
1236 return TypeParameter_to_Null (expr, target_type, loc);
1238 if (TypeManager.IsNullableType (target_type))
1239 return new Nullable.NullableLiteral (target_type, loc);
1242 if (TypeManager.IsNullableType (expr_type) && TypeManager.IsNullableType (target_type))
1243 return new Nullable.LiftedConversion (
1244 expr, target_type, false, false, loc).Resolve (ec);
1246 if (expr.eclass == ExprClass.MethodGroup){
1247 if (!TypeManager.IsDelegateType (target_type)){
1252 // Only allow anonymous method conversions on post ISO_1
1254 if (RootContext.Version != LanguageVersion.ISO_1){
1255 MethodGroupExpr mg = expr as MethodGroupExpr;
1257 return ImplicitDelegateCreation.Create (
1258 ec, mg, target_type, false, loc);
1262 if (expr_type.Equals (target_type) && !TypeManager.IsNullType (expr_type))
1265 e = ImplicitNumericConversion (ec, expr, target_type, loc);
1269 e = ImplicitReferenceConversion (ec, expr, target_type);
1273 if ((target_type == TypeManager.enum_type ||
1274 target_type.IsSubclassOf (TypeManager.enum_type)) &&
1275 expr is IntLiteral){
1276 IntLiteral i = (IntLiteral) expr;
1279 return new EnumConstant ((Constant) expr, target_type);
1283 if (expr_type.IsPointer){
1284 if (target_type == TypeManager.void_ptr_type)
1285 return new EmptyCast (expr, target_type);
1288 // yep, comparing pointer types cant be done with
1289 // t1 == t2, we have to compare their element types.
1291 if (target_type.IsPointer){
1292 if (TypeManager.GetElementType(target_type) == TypeManager.GetElementType(expr_type))
1297 if (target_type.IsPointer) {
1298 if (expr_type == TypeManager.null_type)
1299 return new EmptyCast (NullPointer.Null, target_type);
1301 if (expr_type == TypeManager.void_ptr_type)
1302 return new EmptyCast (expr, target_type);
1306 if (expr_type == TypeManager.anonymous_method_type){
1307 if (!TypeManager.IsDelegateType (target_type)){
1308 Report.Error (1660, loc,
1309 "Cannot convert anonymous method block to type `{0}' because it is not a delegate type",
1310 TypeManager.CSharpName (target_type));
1314 AnonymousMethod am = (AnonymousMethod) expr;
1315 int errors = Report.Errors;
1317 Expression conv = am.Compatible (ec, target_type, false);
1322 // We return something instead of null, to avoid
1323 // the duplicate error, since am.Compatible would have
1324 // reported that already
1326 if (errors != Report.Errors)
1327 return new EmptyCast (expr, target_type);
1334 /// Attempts to perform an implicit constant conversion of the IntConstant
1335 /// into a different data type using casts (See Implicit Constant
1336 /// Expression Conversions)
1338 static public Expression TryImplicitIntConversion (Type target_type, IntConstant ic)
1340 int value = ic.Value;
1342 if (target_type == TypeManager.sbyte_type){
1343 if (value >= SByte.MinValue && value <= SByte.MaxValue)
1344 return new SByteConstant ((sbyte) value, ic.Location);
1345 } else if (target_type == TypeManager.byte_type){
1346 if (value >= Byte.MinValue && value <= Byte.MaxValue)
1347 return new ByteConstant ((byte) value, ic.Location);
1348 } else if (target_type == TypeManager.short_type){
1349 if (value >= Int16.MinValue && value <= Int16.MaxValue)
1350 return new ShortConstant ((short) value, ic.Location);
1351 } else if (target_type == TypeManager.ushort_type){
1352 if (value >= UInt16.MinValue && value <= UInt16.MaxValue)
1353 return new UShortConstant ((ushort) value, ic.Location);
1354 } else if (target_type == TypeManager.uint32_type){
1356 return new UIntConstant ((uint) value, ic.Location);
1357 } else if (target_type == TypeManager.uint64_type){
1359 // we can optimize this case: a positive int32
1360 // always fits on a uint64. But we need an opcode
1364 return new ULongConstant ((ulong) value, ic.Location);
1365 } else if (target_type == TypeManager.double_type)
1366 return new DoubleConstant ((double) value, ic.Location);
1367 else if (target_type == TypeManager.float_type)
1368 return new FloatConstant ((float) value, ic.Location);
1370 if (value == 0 && ic is IntLiteral && TypeManager.IsEnumType (target_type)){
1371 Type underlying = TypeManager.EnumToUnderlying (target_type);
1372 Constant e = (Constant) ic;
1375 // Possibly, we need to create a different 0 literal before passing
1378 if (underlying == TypeManager.int64_type)
1379 e = new LongLiteral (0, ic.Location);
1380 else if (underlying == TypeManager.uint64_type)
1381 e = new ULongLiteral (0, ic.Location);
1383 return new EnumConstant (e, target_type);
1387 // If `target_type' is an interface and the type of `ic' implements the interface
1388 // e.g. target_type is IComparable, IConvertible, IFormattable
1390 if (target_type.IsInterface && target_type.IsAssignableFrom (ic.Type))
1391 return new BoxedCast (ic, target_type);
1396 static public void Error_CannotImplicitConversion (Location loc, Type source, Type target)
1398 if (source.FullName == target.FullName){
1399 Report.ExtraInformation (loc,
1401 "The type {0} has two conflicting definitions, one comes from {1} and the other from {2}",
1402 source.Name, source.Assembly.FullName, target.Assembly.FullName));
1406 // TODO: Missing explicit numeric check
1407 //ExplicitNumericConversion
1409 if (ExplicitReferenceConversionExists (source, target)) {
1410 Report.Error (266, loc, "Cannot implicitly convert type `{0}' to `{1}'. An explicit conversion exists (are you missing a cast?)",
1411 TypeManager.CSharpName (source), TypeManager.CSharpName (target));
1415 Report.Error (29, loc, "Cannot implicitly convert type {0} to `{1}'",
1416 source == TypeManager.anonymous_method_type ?
1417 "anonymous method" : "`" + TypeManager.CSharpName (source) + "'",
1418 TypeManager.CSharpName (target));
1422 /// Attempts to implicitly convert `source' into `target_type', using
1423 /// ImplicitConversion. If there is no implicit conversion, then
1424 /// an error is signaled
1426 static public Expression ImplicitConversionRequired (EmitContext ec, Expression source,
1427 Type target_type, Location loc)
1431 int errors = Report.Errors;
1432 e = ImplicitConversion (ec, source, target_type, loc);
1433 if (Report.Errors > errors)
1438 if (source is DoubleLiteral) {
1439 if (target_type == TypeManager.float_type) {
1440 Error_664 (loc, "float", "f");
1443 if (target_type == TypeManager.decimal_type) {
1444 Error_664 (loc, "decimal", "m");
1449 source.Error_ValueCannotBeConverted (loc, target_type);
1453 static void Error_664 (Location loc, string type, string suffix) {
1454 Report.Error (664, loc,
1455 "Literal of type double cannot be implicitly converted to type `{0}'. Add suffix `{1}' to create a literal of this type",
1460 /// Performs the explicit numeric conversions
1462 static Expression ExplicitNumericConversion (EmitContext ec, Expression expr, Type target_type, Location loc)
1464 Type expr_type = expr.Type;
1467 // If we have an enumeration, extract the underlying type,
1468 // use this during the comparison, but wrap around the original
1471 Type real_target_type = target_type;
1473 if (TypeManager.IsEnumType (real_target_type))
1474 real_target_type = TypeManager.EnumToUnderlying (real_target_type);
1476 if (ImplicitStandardConversionExists (ec, expr, real_target_type)){
1477 Expression ce = ImplicitConversionStandard (ec, expr, real_target_type, loc);
1479 if (real_target_type != target_type)
1480 return new EmptyCast (ce, target_type);
1484 if (expr_type == TypeManager.sbyte_type){
1486 // From sbyte to byte, ushort, uint, ulong, char
1488 if (real_target_type == TypeManager.byte_type)
1489 return new ConvCast (ec, expr, target_type, ConvCast.Mode.I1_U1);
1490 if (real_target_type == TypeManager.ushort_type)
1491 return new ConvCast (ec, expr, target_type, ConvCast.Mode.I1_U2);
1492 if (real_target_type == TypeManager.uint32_type)
1493 return new ConvCast (ec, expr, target_type, ConvCast.Mode.I1_U4);
1494 if (real_target_type == TypeManager.uint64_type)
1495 return new ConvCast (ec, expr, target_type, ConvCast.Mode.I1_U8);
1496 if (real_target_type == TypeManager.char_type)
1497 return new ConvCast (ec, expr, target_type, ConvCast.Mode.I1_CH);
1498 } else if (expr_type == TypeManager.byte_type){
1500 // From byte to sbyte and char
1502 if (real_target_type == TypeManager.sbyte_type)
1503 return new ConvCast (ec, expr, target_type, ConvCast.Mode.U1_I1);
1504 if (real_target_type == TypeManager.char_type)
1505 return new ConvCast (ec, expr, target_type, ConvCast.Mode.U1_CH);
1506 } else if (expr_type == TypeManager.short_type){
1508 // From short to sbyte, byte, ushort, uint, ulong, char
1510 if (real_target_type == TypeManager.sbyte_type)
1511 return new ConvCast (ec, expr, target_type, ConvCast.Mode.I2_I1);
1512 if (real_target_type == TypeManager.byte_type)
1513 return new ConvCast (ec, expr, target_type, ConvCast.Mode.I2_U1);
1514 if (real_target_type == TypeManager.ushort_type)
1515 return new ConvCast (ec, expr, target_type, ConvCast.Mode.I2_U2);
1516 if (real_target_type == TypeManager.uint32_type)
1517 return new ConvCast (ec, expr, target_type, ConvCast.Mode.I2_U4);
1518 if (real_target_type == TypeManager.uint64_type)
1519 return new ConvCast (ec, expr, target_type, ConvCast.Mode.I2_U8);
1520 if (real_target_type == TypeManager.char_type)
1521 return new ConvCast (ec, expr, target_type, ConvCast.Mode.I2_CH);
1522 } else if (expr_type == TypeManager.ushort_type){
1524 // From ushort to sbyte, byte, short, char
1526 if (real_target_type == TypeManager.sbyte_type)
1527 return new ConvCast (ec, expr, target_type, ConvCast.Mode.U2_I1);
1528 if (real_target_type == TypeManager.byte_type)
1529 return new ConvCast (ec, expr, target_type, ConvCast.Mode.U2_U1);
1530 if (real_target_type == TypeManager.short_type)
1531 return new ConvCast (ec, expr, target_type, ConvCast.Mode.U2_I2);
1532 if (real_target_type == TypeManager.char_type)
1533 return new ConvCast (ec, expr, target_type, ConvCast.Mode.U2_CH);
1534 } else if (expr_type == TypeManager.int32_type){
1536 // From int to sbyte, byte, short, ushort, uint, ulong, char
1538 if (real_target_type == TypeManager.sbyte_type)
1539 return new ConvCast (ec, expr, target_type, ConvCast.Mode.I4_I1);
1540 if (real_target_type == TypeManager.byte_type)
1541 return new ConvCast (ec, expr, target_type, ConvCast.Mode.I4_U1);
1542 if (real_target_type == TypeManager.short_type)
1543 return new ConvCast (ec, expr, target_type, ConvCast.Mode.I4_I2);
1544 if (real_target_type == TypeManager.ushort_type)
1545 return new ConvCast (ec, expr, target_type, ConvCast.Mode.I4_U2);
1546 if (real_target_type == TypeManager.uint32_type)
1547 return new ConvCast (ec, expr, target_type, ConvCast.Mode.I4_U4);
1548 if (real_target_type == TypeManager.uint64_type)
1549 return new ConvCast (ec, expr, target_type, ConvCast.Mode.I4_U8);
1550 if (real_target_type == TypeManager.char_type)
1551 return new ConvCast (ec, expr, target_type, ConvCast.Mode.I4_CH);
1552 } else if (expr_type == TypeManager.uint32_type){
1554 // From uint to sbyte, byte, short, ushort, int, char
1556 if (real_target_type == TypeManager.sbyte_type)
1557 return new ConvCast (ec, expr, target_type, ConvCast.Mode.U4_I1);
1558 if (real_target_type == TypeManager.byte_type)
1559 return new ConvCast (ec, expr, target_type, ConvCast.Mode.U4_U1);
1560 if (real_target_type == TypeManager.short_type)
1561 return new ConvCast (ec, expr, target_type, ConvCast.Mode.U4_I2);
1562 if (real_target_type == TypeManager.ushort_type)
1563 return new ConvCast (ec, expr, target_type, ConvCast.Mode.U4_U2);
1564 if (real_target_type == TypeManager.int32_type)
1565 return new ConvCast (ec, expr, target_type, ConvCast.Mode.U4_I4);
1566 if (real_target_type == TypeManager.char_type)
1567 return new ConvCast (ec, expr, target_type, ConvCast.Mode.U4_CH);
1568 } else if (expr_type == TypeManager.int64_type){
1570 // From long to sbyte, byte, short, ushort, int, uint, ulong, char
1572 if (real_target_type == TypeManager.sbyte_type)
1573 return new ConvCast (ec, expr, target_type, ConvCast.Mode.I8_I1);
1574 if (real_target_type == TypeManager.byte_type)
1575 return new ConvCast (ec, expr, target_type, ConvCast.Mode.I8_U1);
1576 if (real_target_type == TypeManager.short_type)
1577 return new ConvCast (ec, expr, target_type, ConvCast.Mode.I8_I2);
1578 if (real_target_type == TypeManager.ushort_type)
1579 return new ConvCast (ec, expr, target_type, ConvCast.Mode.I8_U2);
1580 if (real_target_type == TypeManager.int32_type)
1581 return new ConvCast (ec, expr, target_type, ConvCast.Mode.I8_I4);
1582 if (real_target_type == TypeManager.uint32_type)
1583 return new ConvCast (ec, expr, target_type, ConvCast.Mode.I8_U4);
1584 if (real_target_type == TypeManager.uint64_type)
1585 return new ConvCast (ec, expr, target_type, ConvCast.Mode.I8_U8);
1586 if (real_target_type == TypeManager.char_type)
1587 return new ConvCast (ec, expr, target_type, ConvCast.Mode.I8_CH);
1588 } else if (expr_type == TypeManager.uint64_type){
1590 // From ulong to sbyte, byte, short, ushort, int, uint, long, char
1592 if (real_target_type == TypeManager.sbyte_type)
1593 return new ConvCast (ec, expr, target_type, ConvCast.Mode.U8_I1);
1594 if (real_target_type == TypeManager.byte_type)
1595 return new ConvCast (ec, expr, target_type, ConvCast.Mode.U8_U1);
1596 if (real_target_type == TypeManager.short_type)
1597 return new ConvCast (ec, expr, target_type, ConvCast.Mode.U8_I2);
1598 if (real_target_type == TypeManager.ushort_type)
1599 return new ConvCast (ec, expr, target_type, ConvCast.Mode.U8_U2);
1600 if (real_target_type == TypeManager.int32_type)
1601 return new ConvCast (ec, expr, target_type, ConvCast.Mode.U8_I4);
1602 if (real_target_type == TypeManager.uint32_type)
1603 return new ConvCast (ec, expr, target_type, ConvCast.Mode.U8_U4);
1604 if (real_target_type == TypeManager.int64_type)
1605 return new ConvCast (ec, expr, target_type, ConvCast.Mode.U8_I8);
1606 if (real_target_type == TypeManager.char_type)
1607 return new ConvCast (ec, expr, target_type, ConvCast.Mode.U8_CH);
1608 } else if (expr_type == TypeManager.char_type){
1610 // From char to sbyte, byte, short
1612 if (real_target_type == TypeManager.sbyte_type)
1613 return new ConvCast (ec, expr, target_type, ConvCast.Mode.CH_I1);
1614 if (real_target_type == TypeManager.byte_type)
1615 return new ConvCast (ec, expr, target_type, ConvCast.Mode.CH_U1);
1616 if (real_target_type == TypeManager.short_type)
1617 return new ConvCast (ec, expr, target_type, ConvCast.Mode.CH_I2);
1618 } else if (expr_type == TypeManager.float_type){
1620 // From float to sbyte, byte, short,
1621 // ushort, int, uint, long, ulong, char
1624 if (real_target_type == TypeManager.sbyte_type)
1625 return new ConvCast (ec, expr, target_type, ConvCast.Mode.R4_I1);
1626 if (real_target_type == TypeManager.byte_type)
1627 return new ConvCast (ec, expr, target_type, ConvCast.Mode.R4_U1);
1628 if (real_target_type == TypeManager.short_type)
1629 return new ConvCast (ec, expr, target_type, ConvCast.Mode.R4_I2);
1630 if (real_target_type == TypeManager.ushort_type)
1631 return new ConvCast (ec, expr, target_type, ConvCast.Mode.R4_U2);
1632 if (real_target_type == TypeManager.int32_type)
1633 return new ConvCast (ec, expr, target_type, ConvCast.Mode.R4_I4);
1634 if (real_target_type == TypeManager.uint32_type)
1635 return new ConvCast (ec, expr, target_type, ConvCast.Mode.R4_U4);
1636 if (real_target_type == TypeManager.int64_type)
1637 return new ConvCast (ec, expr, target_type, ConvCast.Mode.R4_I8);
1638 if (real_target_type == TypeManager.uint64_type)
1639 return new ConvCast (ec, expr, target_type, ConvCast.Mode.R4_U8);
1640 if (real_target_type == TypeManager.char_type)
1641 return new ConvCast (ec, expr, target_type, ConvCast.Mode.R4_CH);
1642 if (real_target_type == TypeManager.decimal_type)
1643 return new CastToDecimal (ec, expr, true);
1644 } else if (expr_type == TypeManager.double_type){
1646 // From double to sbyte, byte, short,
1647 // ushort, int, uint, long, ulong,
1648 // char, float or decimal
1650 if (real_target_type == TypeManager.sbyte_type)
1651 return new ConvCast (ec, expr, target_type, ConvCast.Mode.R8_I1);
1652 if (real_target_type == TypeManager.byte_type)
1653 return new ConvCast (ec, expr, target_type, ConvCast.Mode.R8_U1);
1654 if (real_target_type == TypeManager.short_type)
1655 return new ConvCast (ec, expr, target_type, ConvCast.Mode.R8_I2);
1656 if (real_target_type == TypeManager.ushort_type)
1657 return new ConvCast (ec, expr, target_type, ConvCast.Mode.R8_U2);
1658 if (real_target_type == TypeManager.int32_type)
1659 return new ConvCast (ec, expr, target_type, ConvCast.Mode.R8_I4);
1660 if (real_target_type == TypeManager.uint32_type)
1661 return new ConvCast (ec, expr, target_type, ConvCast.Mode.R8_U4);
1662 if (real_target_type == TypeManager.int64_type)
1663 return new ConvCast (ec, expr, target_type, ConvCast.Mode.R8_I8);
1664 if (real_target_type == TypeManager.uint64_type)
1665 return new ConvCast (ec, expr, target_type, ConvCast.Mode.R8_U8);
1666 if (real_target_type == TypeManager.char_type)
1667 return new ConvCast (ec, expr, target_type, ConvCast.Mode.R8_CH);
1668 if (real_target_type == TypeManager.float_type)
1669 return new ConvCast (ec, expr, target_type, ConvCast.Mode.R8_R4);
1670 if (real_target_type == TypeManager.decimal_type)
1671 return new CastToDecimal (ec, expr, true);
1672 } else if (expr_type == TypeManager.decimal_type) {
1674 // From decimal to sbyte, byte, short, ushort, int, uint,
1675 // long, ulong, char, double or float
1677 if (real_target_type == TypeManager.sbyte_type ||
1678 real_target_type == TypeManager.byte_type ||
1679 real_target_type == TypeManager.short_type ||
1680 real_target_type == TypeManager.ushort_type ||
1681 real_target_type == TypeManager.int32_type ||
1682 real_target_type == TypeManager.uint32_type ||
1683 real_target_type == TypeManager.int64_type ||
1684 real_target_type == TypeManager.uint64_type ||
1685 real_target_type == TypeManager.char_type ||
1686 real_target_type == TypeManager.double_type ||
1687 real_target_type == TypeManager.float_type)
1688 return new CastFromDecimal (ec, expr, target_type);
1694 /// Returns whether an explicit reference conversion can be performed
1695 /// from source_type to target_type
1697 public static bool ExplicitReferenceConversionExists (Type source_type, Type target_type)
1699 bool target_is_type_param = target_type.IsGenericParameter;
1700 bool target_is_value_type = target_type.IsValueType;
1702 if (source_type == target_type)
1706 // From generic parameter to any type
1708 if (source_type.IsGenericParameter)
1712 // From object to a generic parameter
1714 if (source_type == TypeManager.object_type && target_is_type_param)
1718 // From object to any reference type
1720 if (source_type == TypeManager.object_type && !target_is_value_type)
1724 // From any class S to any class-type T, provided S is a base class of T
1726 if (TypeManager.IsSubclassOf (target_type, source_type))
1730 // From any interface type S to any interface T provided S is not derived from T
1732 if (source_type.IsInterface && target_type.IsInterface){
1733 if (!TypeManager.IsSubclassOf (target_type, source_type))
1738 // From any class type S to any interface T, provided S is not sealed
1739 // and provided S does not implement T.
1741 if (target_type.IsInterface && !source_type.IsSealed &&
1742 !TypeManager.ImplementsInterface (source_type, target_type))
1746 // From any interface-type S to to any class type T, provided T is not
1747 // sealed, or provided T implements S.
1749 if (source_type.IsInterface &&
1750 (!target_type.IsSealed || TypeManager.ImplementsInterface (target_type, source_type)))
1754 // From an array type S with an element type Se to an array type T with an
1755 // element type Te provided all the following are true:
1756 // * S and T differe only in element type, in other words, S and T
1757 // have the same number of dimensions.
1758 // * Both Se and Te are reference types
1759 // * An explicit referenc conversions exist from Se to Te
1761 if (source_type.IsArray && target_type.IsArray) {
1762 if (source_type.GetArrayRank () == target_type.GetArrayRank ()) {
1764 Type source_element_type = TypeManager.GetElementType (source_type);
1765 Type target_element_type = TypeManager.GetElementType (target_type);
1767 if (source_element_type.IsGenericParameter ||
1768 (!source_element_type.IsValueType && !target_element_type.IsValueType))
1769 if (ExplicitReferenceConversionExists (source_element_type,
1770 target_element_type))
1776 // From System.Array to any array-type
1777 if (source_type == TypeManager.array_type &&
1778 target_type.IsArray){
1783 // From System delegate to any delegate-type
1785 if (source_type == TypeManager.delegate_type &&
1786 TypeManager.IsDelegateType (target_type))
1790 // From ICloneable to Array or Delegate types
1792 if (source_type == TypeManager.icloneable_type &&
1793 (target_type == TypeManager.array_type ||
1794 target_type == TypeManager.delegate_type))
1801 /// Implements Explicit Reference conversions
1803 static Expression ExplicitReferenceConversion (Expression source, Type target_type)
1805 Type source_type = source.Type;
1806 bool target_is_type_param = target_type.IsGenericParameter;
1807 bool target_is_value_type = target_type.IsValueType;
1810 // From object to a generic parameter
1812 if (source_type == TypeManager.object_type && target_is_type_param)
1813 return new UnboxCast (source, target_type);
1816 // From object to any reference type
1818 if (source_type == TypeManager.object_type && !target_is_value_type)
1819 return new ClassCast (source, target_type);
1822 // Unboxing conversion.
1824 if (((source_type == TypeManager.enum_type &&
1825 !(source is EmptyCast)) ||
1826 source_type == TypeManager.value_type) && target_is_value_type)
1827 return new UnboxCast (source, target_type);
1830 // From any class S to any class-type T, provided S is a base class of T
1832 if (TypeManager.IsSubclassOf (target_type, source_type))
1833 return new ClassCast (source, target_type);
1836 // From any interface type S to any interface T provided S is not derived from T
1838 if (source_type.IsInterface && target_type.IsInterface){
1839 if (TypeManager.ImplementsInterface (source_type, target_type))
1842 return new ClassCast (source, target_type);
1846 // From any class type S to any interface T, provides S is not sealed
1847 // and provided S does not implement T.
1849 if (target_type.IsInterface && !source_type.IsSealed) {
1850 if (TypeManager.ImplementsInterface (source_type, target_type))
1853 return new ClassCast (source, target_type);
1858 // From any interface-type S to to any class type T, provided T is not
1859 // sealed, or provided T implements S.
1861 if (source_type.IsInterface) {
1862 if (!target_type.IsSealed || TypeManager.ImplementsInterface (target_type, source_type)) {
1863 if (target_type.IsClass)
1864 return new ClassCast (source, target_type);
1866 return new UnboxCast (source, target_type);
1872 // From an array type S with an element type Se to an array type T with an
1873 // element type Te provided all the following are true:
1874 // * S and T differe only in element type, in other words, S and T
1875 // have the same number of dimensions.
1876 // * Both Se and Te are reference types
1877 // * An explicit referenc conversions exist from Se to Te
1879 if (source_type.IsArray && target_type.IsArray) {
1880 if (source_type.GetArrayRank () == target_type.GetArrayRank ()) {
1882 Type source_element_type = TypeManager.GetElementType (source_type);
1883 Type target_element_type = TypeManager.GetElementType (target_type);
1885 if (!source_element_type.IsValueType && !target_element_type.IsValueType)
1886 if (ExplicitReferenceConversionExists (source_element_type,
1887 target_element_type))
1888 return new ClassCast (source, target_type);
1893 // From System.Array to any array-type
1894 if (source_type == TypeManager.array_type &&
1895 target_type.IsArray) {
1896 return new ClassCast (source, target_type);
1900 // From System delegate to any delegate-type
1902 if (source_type == TypeManager.delegate_type &&
1903 TypeManager.IsDelegateType (target_type))
1904 return new ClassCast (source, target_type);
1907 // From ICloneable to Array or Delegate types
1909 if (source_type == TypeManager.icloneable_type &&
1910 (target_type == TypeManager.array_type ||
1911 target_type == TypeManager.delegate_type))
1912 return new ClassCast (source, target_type);
1918 /// Performs an explicit conversion of the expression `expr' whose
1919 /// type is expr.Type to `target_type'.
1921 static public Expression ExplicitConversion (EmitContext ec, Expression expr,
1922 Type target_type, Location loc)
1924 Type expr_type = expr.Type;
1925 Type original_expr_type = expr_type;
1927 Expression ne = ImplicitConversionStandard (ec, expr, target_type, loc);
1932 if (expr_type.IsSubclassOf (TypeManager.enum_type)){
1933 if ((expr_type == TypeManager.enum_type) && target_type.IsValueType &&
1934 target_type.IsSubclassOf (TypeManager.enum_type))
1935 return new UnboxCast (expr, target_type);
1938 // Notice that we have kept the expr_type unmodified, which is only
1940 if (expr is EnumConstant)
1941 expr = ((EnumConstant) expr).Child;
1943 expr = new EmptyCast (expr, TypeManager.EnumToUnderlying (expr_type));
1944 expr_type = expr.Type;
1947 if (TypeManager.IsNullableType (expr.Type) && TypeManager.IsNullableType (target_type))
1948 return new Nullable.LiftedConversion (
1949 expr, target_type, false, true, loc).Resolve (ec);
1951 ne = ExplicitNumericConversion (ec, expr, target_type, loc);
1956 // Unboxing conversion.
1958 if (expr_type == TypeManager.object_type && target_type.IsValueType)
1959 return new UnboxCast (expr, target_type);
1962 // Skip the ExplicitReferenceConversion because we can not convert
1963 // from Null to a ValueType, and ExplicitReference wont check against
1964 // null literal explicitly
1966 if (expr_type != TypeManager.null_type){
1967 ne = ExplicitReferenceConversion (expr, target_type);
1973 if (target_type.IsPointer){
1974 if (expr_type.IsPointer)
1975 return new EmptyCast (expr, target_type);
1977 if (expr_type == TypeManager.sbyte_type ||
1978 expr_type == TypeManager.short_type ||
1979 expr_type == TypeManager.int32_type ||
1980 expr_type == TypeManager.int64_type)
1981 return new OpcodeCast (expr, target_type, OpCodes.Conv_I);
1983 if (expr_type == TypeManager.ushort_type ||
1984 expr_type == TypeManager.uint32_type ||
1985 expr_type == TypeManager.uint64_type ||
1986 expr_type == TypeManager.byte_type)
1987 return new OpcodeCast (expr, target_type, OpCodes.Conv_U);
1989 if (expr_type.IsPointer){
1990 Expression e = null;
1992 if (target_type == TypeManager.sbyte_type)
1993 e = new OpcodeCast (expr, target_type, OpCodes.Conv_I1);
1994 else if (target_type == TypeManager.byte_type)
1995 e = new OpcodeCast (expr, target_type, OpCodes.Conv_U1);
1996 else if (target_type == TypeManager.short_type)
1997 e = new OpcodeCast (expr, target_type, OpCodes.Conv_I2);
1998 else if (target_type == TypeManager.ushort_type)
1999 e = new OpcodeCast (expr, target_type, OpCodes.Conv_U2);
2000 else if (target_type == TypeManager.int32_type)
2001 e = new OpcodeCast (expr, target_type, OpCodes.Conv_I4);
2002 else if (target_type == TypeManager.uint32_type)
2003 e = new OpcodeCast (expr, target_type, OpCodes.Conv_U4);
2004 else if (target_type == TypeManager.uint64_type)
2005 e = new OpcodeCast (expr, target_type, OpCodes.Conv_U8);
2006 else if (target_type == TypeManager.int64_type){
2007 e = new OpcodeCast (expr, target_type, OpCodes.Conv_I8);
2013 ci = ImplicitConversionStandard (ec, e, target_type, loc);
2018 ce = ExplicitNumericConversion (ec, e, target_type, loc);
2022 // We should always be able to go from an uint32
2023 // implicitly or explicitly to the other integral
2026 throw new Exception ("Internal compiler error");
2031 ne = ExplicitUserConversion (ec, expr, target_type, loc);
2035 if (expr is Constant)
2036 expr.Error_ValueCannotBeConverted (loc, target_type);
2038 Error_CannotConvertType (loc, original_expr_type, target_type);
2043 /// Same as ExplicitConversion, only it doesn't include user defined conversions
2045 static public Expression ExplicitConversionStandard (EmitContext ec, Expression expr,
2046 Type target_type, Location l)
2048 int errors = Report.Errors;
2049 Expression ne = ImplicitConversionStandard (ec, expr, target_type, l);
2050 if (Report.Errors > errors)
2056 if (TypeManager.IsNullableType (expr.Type) && TypeManager.IsNullableType (target_type))
2057 return new Nullable.LiftedConversion (
2058 expr, target_type, false, true, l).Resolve (ec);
2060 ne = ExplicitNumericConversion (ec, expr, target_type, l);
2064 ne = ExplicitReferenceConversion (expr, target_type);
2068 Error_CannotConvertType (l, expr.Type, target_type);