?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
[mcs] Inflate constraints of compiler generated proxy base call methods. Fixes #52294
[mono-project.git] / mcs / mcs / generic.cs
blob8ddef4f36947b630ee655efd11adbe80fa385b5c
1 //
2 // generic.cs: Generics support
3 //
4 // Authors: Martin Baulig (martin@ximian.com)
5 // Miguel de Icaza (miguel@ximian.com)
6 // Marek Safar (marek.safar@gmail.com)
7 //
8 // Dual licensed under the terms of the MIT X11 or GNU GPL
9 //
10 // Copyright 2001, 2002, 2003 Ximian, Inc (http://www.ximian.com)
11 // Copyright 2004-2008 Novell, Inc
12 // Copyright 2011 Xamarin, Inc (http://www.xamarin.com)
13 //
14
15 using System;
16 using System.Collections.Generic;
17 using System.Text;
18 using System.Linq;
19
20 #if STATIC
21 using MetaType = IKVM.Reflection.Type;
22 using IKVM.Reflection;
23 using IKVM.Reflection.Emit;
24 #else
25 using MetaType = System.Type;
26 using System.Reflection;
27 using System.Reflection.Emit;
28 #endif
29
30 namespace Mono.CSharp {
31 public class VarianceDecl
32 {
33 public VarianceDecl (Variance variance, Location loc)
34 {
35 this.Variance = variance;
36 this.Location = loc;
37 }
38
39 public Variance Variance { get; private set; }
40 public Location Location { get; private set; }
41
42 public static Variance CheckTypeVariance (TypeSpec t, Variance expected, IMemberContext member)
43 {
44 var tp = t as TypeParameterSpec;
45 if (tp != null) {
46 var v = tp.Variance;
47 if (expected == Variance.None && v != expected ||
48 expected == Variance.Covariant && v == Variance.Contravariant ||
49 expected == Variance.Contravariant && v == Variance.Covariant) {
50 ((TypeParameter) tp.MemberDefinition).ErrorInvalidVariance (member, expected);
51 }
52
53 return expected;
54 }
55
56 if (t.TypeArguments.Length > 0) {
57 var targs_definition = t.MemberDefinition.TypeParameters;
58 TypeSpec[] targs = TypeManager.GetTypeArguments (t);
59 for (int i = 0; i < targs.Length; ++i) {
60 var v = targs_definition[i].Variance;
61 CheckTypeVariance (targs[i], (Variance) ((int) v * (int) expected), member);
62 }
63
64 return expected;
65 }
66
67 var ac = t as ArrayContainer;
68 if (ac != null)
69 return CheckTypeVariance (ac.Element, expected, member);
70
71 return Variance.None;
72 }
73 }
74
75 public enum Variance
76 {
77 //
78 // Don't add or modify internal values, they are used as -/+ calculation signs
79 //
80 None = 0,
81 Covariant = 1,
82 Contravariant = -1
83 }
84
85 [Flags]
86 public enum SpecialConstraint
87 {
88 None = 0,
89 Constructor = 1 << 2,
90 Class = 1 << 3,
91 Struct = 1 << 4
92 }
93
94 public class SpecialContraintExpr : FullNamedExpression
95 {
96 public SpecialContraintExpr (SpecialConstraint constraint, Location loc)
97 {
98 this.loc = loc;
99 this.Constraint = constraint;
100 }
101
102 public SpecialConstraint Constraint { get; private set; }
103
104 protected override Expression DoResolve (ResolveContext rc)
105 {
106 throw new NotImplementedException ();
107 }
108
109 public override FullNamedExpression ResolveAsTypeOrNamespace (IMemberContext mc, bool allowUnboundTypeArguments)
110 {
111 throw new NotImplementedException ();
112 }
113 }
114
115 //
116 // A set of parsed constraints for a type parameter
117 //
118 public class Constraints
119 {
120 readonly SimpleMemberName tparam;
121 readonly List<FullNamedExpression> constraints;
122 readonly Location loc;
123 bool resolved;
124 bool resolving;
125
126 public Constraints (SimpleMemberName tparam, List<FullNamedExpression> constraints, Location loc)
127 {
128 this.tparam = tparam;
129 this.constraints = constraints;
130 this.loc = loc;
131 }
132
133 #region Properties
134
135 public List<FullNamedExpression> TypeExpressions {
136 get {
137 return constraints;
138 }
139 }
140
141 public Location Location {
142 get {
143 return loc;
144 }
145 }
146
147 public SimpleMemberName TypeParameter {
148 get {
149 return tparam;
150 }
151 }
152
153 #endregion
154
155 public static bool CheckConflictingInheritedConstraint (TypeParameterSpec spec, TypeSpec bb, IMemberContext context, Location loc)
156 {
157 if (spec.HasSpecialClass && bb.IsStruct) {
158 context.Module.Compiler.Report.Error (455, loc,
159 "Type parameter `{0}' inherits conflicting constraints `{1}' and `{2}'",
160 spec.Name, "class", bb.GetSignatureForError ());
161
162 return false;
163 }
164
165 return CheckConflictingInheritedConstraint (spec, spec.BaseType, bb, context, loc);
166 }
167
168 static bool CheckConflictingInheritedConstraint (TypeParameterSpec spec, TypeSpec ba, TypeSpec bb, IMemberContext context, Location loc)
169 {
170 if (ba == bb)
171 return true;
172
173 if (TypeSpec.IsBaseClass (ba, bb, false) || TypeSpec.IsBaseClass (bb, ba, false))
174 return true;
175
176 Error_ConflictingConstraints (context, spec, ba, bb, loc);
177 return false;
178 }
179
180 public static void Error_ConflictingConstraints (IMemberContext context, TypeParameterSpec tp, TypeSpec ba, TypeSpec bb, Location loc)
181 {
182 context.Module.Compiler.Report.Error (455, loc,
183 "Type parameter `{0}' inherits conflicting constraints `{1}' and `{2}'",
184 tp.Name, ba.GetSignatureForError (), bb.GetSignatureForError ());
185 }
186
187 public void CheckGenericConstraints (IMemberContext context, bool obsoleteCheck)
188 {
189 foreach (var c in constraints) {
190 if (c == null)
191 continue;
192
193 var t = c.Type;
194 if (t == null)
195 continue;
196
197 if (obsoleteCheck) {
198 t.CheckObsoleteness (context, c.Location);
199 }
200
201 ConstraintChecker.Check (context, t, c.Location);
202 }
203 }
204
205 //
206 // Resolve the constraints types with only possible early checks, return
207 // value `false' is reserved for recursive failure
208 //
209 public bool Resolve (IMemberContext context, TypeParameter tp)
210 {
211 if (resolved)
212 return true;
213
214 if (resolving)
215 return false;
216
217 resolving = true;
218 var spec = tp.Type;
219 List<TypeParameterSpec> tparam_types = null;
220 bool iface_found = false;
221
222 spec.BaseType = context.Module.Compiler.BuiltinTypes.Object;
223
224 for (int i = 0; i < constraints.Count; ++i) {
225 var constraint = constraints[i];
226
227 if (constraint is SpecialContraintExpr) {
228 spec.SpecialConstraint |= ((SpecialContraintExpr) constraint).Constraint;
229 if (spec.HasSpecialStruct)
230 spec.BaseType = context.Module.Compiler.BuiltinTypes.ValueType;
231
232 // Set to null as it does not have a type
233 constraints[i] = null;
234 continue;
235 }
236
237 var type = constraint.ResolveAsType (context);
238 if (type == null)
239 continue;
240
241 if (type.Arity > 0 && ((InflatedTypeSpec) type).HasDynamicArgument ()) {
242 context.Module.Compiler.Report.Error (1968, constraint.Location,
243 "A constraint cannot be the dynamic type `{0}'", type.GetSignatureForError ());
244 continue;
245 }
246
247 if (!context.CurrentMemberDefinition.IsAccessibleAs (type)) {
248 context.Module.Compiler.Report.SymbolRelatedToPreviousError (type);
249 context.Module.Compiler.Report.Error (703, loc,
250 "Inconsistent accessibility: constraint type `{0}' is less accessible than `{1}'",
251 type.GetSignatureForError (), context.GetSignatureForError ());
252 }
253
254 if (type.IsInterface) {
255 if (!spec.AddInterface (type)) {
256 context.Module.Compiler.Report.Error (405, constraint.Location,
257 "Duplicate constraint `{0}' for type parameter `{1}'", type.GetSignatureForError (), tparam.Value);
258 }
259
260 iface_found = true;
261 continue;
262 }
263
264 var constraint_tp = type as TypeParameterSpec;
265 if (constraint_tp != null) {
266 if (tparam_types == null) {
267 tparam_types = new List<TypeParameterSpec> (2);
268 } else if (tparam_types.Contains (constraint_tp)) {
269 context.Module.Compiler.Report.Error (405, constraint.Location,
270 "Duplicate constraint `{0}' for type parameter `{1}'", type.GetSignatureForError (), tparam.Value);
271 continue;
272 }
273
274 //
275 // Checks whether each generic method parameter constraint type
276 // is valid with respect to T
277 //
278 if (tp.IsMethodTypeParameter) {
279 VarianceDecl.CheckTypeVariance (type, Variance.Contravariant, context);
280 }
281
282 var tp_def = constraint_tp.MemberDefinition as TypeParameter;
283 if (tp_def != null && !tp_def.ResolveConstraints (context)) {
284 context.Module.Compiler.Report.Error (454, constraint.Location,
285 "Circular constraint dependency involving `{0}' and `{1}'",
286 constraint_tp.GetSignatureForError (), tp.GetSignatureForError ());
287 continue;
288 }
289
290 //
291 // Checks whether there are no conflicts between type parameter constraints
292 //
293 // class Foo<T, U>
294 // where T : A
295 // where U : B, T
296 //
297 // A and B are not convertible and only 1 class constraint is allowed
298 //
299 if (constraint_tp.HasTypeConstraint) {
300 if (spec.HasTypeConstraint || spec.HasSpecialStruct) {
301 if (!CheckConflictingInheritedConstraint (spec, constraint_tp.BaseType, context, constraint.Location))
302 continue;
303 } else {
304 for (int ii = 0; ii < tparam_types.Count; ++ii) {
305 if (!tparam_types[ii].HasTypeConstraint)
306 continue;
307
308 if (!CheckConflictingInheritedConstraint (spec, tparam_types[ii].BaseType, constraint_tp.BaseType, context, constraint.Location))
309 break;
310 }
311 }
312 }
313
314 if (constraint_tp.TypeArguments != null) {
315 var eb = constraint_tp.GetEffectiveBase ();
316 if (eb != null && !CheckConflictingInheritedConstraint (spec, eb, spec.BaseType, context, constraint.Location))
317 break;
318 }
319
320 if (constraint_tp.HasSpecialStruct) {
321 context.Module.Compiler.Report.Error (456, constraint.Location,
322 "Type parameter `{0}' has the `struct' constraint, so it cannot be used as a constraint for `{1}'",
323 constraint_tp.GetSignatureForError (), tp.GetSignatureForError ());
324 continue;
325 }
326
327 tparam_types.Add (constraint_tp);
328 continue;
329 }
330
331 if (iface_found || spec.HasTypeConstraint) {
332 context.Module.Compiler.Report.Error (406, constraint.Location,
333 "The class type constraint `{0}' must be listed before any other constraints. Consider moving type constraint to the beginning of the constraint list",
334 type.GetSignatureForError ());
335 }
336
337 if (spec.HasSpecialStruct || spec.HasSpecialClass) {
338 context.Module.Compiler.Report.Error (450, constraint.Location,
339 "`{0}': cannot specify both a constraint class and the `class' or `struct' constraint",
340 type.GetSignatureForError ());
341 }
342
343 switch (type.BuiltinType) {
344 case BuiltinTypeSpec.Type.Array:
345 case BuiltinTypeSpec.Type.Delegate:
346 case BuiltinTypeSpec.Type.MulticastDelegate:
347 case BuiltinTypeSpec.Type.Enum:
348 case BuiltinTypeSpec.Type.ValueType:
349 case BuiltinTypeSpec.Type.Object:
350 context.Module.Compiler.Report.Error (702, constraint.Location,
351 "A constraint cannot be special class `{0}'", type.GetSignatureForError ());
352 continue;
353 case BuiltinTypeSpec.Type.Dynamic:
354 context.Module.Compiler.Report.Error (1967, constraint.Location,
355 "A constraint cannot be the dynamic type");
356 continue;
357 }
358
359 if (type.IsSealed || !type.IsClass) {
360 context.Module.Compiler.Report.Error (701, loc,
361 "`{0}' is not a valid constraint. A constraint must be an interface, a non-sealed class or a type parameter",
362 type.GetSignatureForError ());
363 continue;
364 }
365
366 if (type.IsStatic) {
367 context.Module.Compiler.Report.Error (717, constraint.Location,
368 "`{0}' is not a valid constraint. Static classes cannot be used as constraints",
369 type.GetSignatureForError ());
370 }
371
372 spec.BaseType = type;
373 }
374
375 if (tparam_types != null)
376 spec.TypeArguments = tparam_types.ToArray ();
377
378 resolving = false;
379 resolved = true;
380 return true;
381 }
382
383 public void VerifyClsCompliance (Report report)
384 {
385 foreach (var c in constraints)
386 {
387 if (c == null)
388 continue;
389
390 if (!c.Type.IsCLSCompliant ()) {
391 report.SymbolRelatedToPreviousError (c.Type);
392 report.Warning (3024, 1, loc, "Constraint type `{0}' is not CLS-compliant",
393 c.Type.GetSignatureForError ());
394 }
395 }
396 }
397 }
398
399 //
400 // A type parameter for a generic type or generic method definition
401 //
402 public class TypeParameter : MemberCore, ITypeDefinition
403 {
404 static readonly string[] attribute_target = { "type parameter" };
405
406 Constraints constraints;
407 GenericTypeParameterBuilder builder;
408 readonly TypeParameterSpec spec;
409
410 public TypeParameter (int index, MemberName name, Constraints constraints, Attributes attrs, Variance Variance)
411 : base (null, name, attrs)
412 {
413 this.constraints = constraints;
414 this.spec = new TypeParameterSpec (null, index, this, SpecialConstraint.None, Variance, null);
415 }
416
417 //
418 // Used by parser
419 //
420 public TypeParameter (MemberName name, Attributes attrs, VarianceDecl variance)
421 : base (null, name, attrs)
422 {
423 var var = variance == null ? Variance.None : variance.Variance;
424 this.spec = new TypeParameterSpec (null, -1, this, SpecialConstraint.None, var, null);
425 this.VarianceDecl = variance;
426 }
427
428 public TypeParameter (TypeParameterSpec spec, TypeSpec parentSpec, MemberName name, Attributes attrs)
429 : base (null, name, attrs)
430 {
431 this.spec = new TypeParameterSpec (parentSpec, spec.DeclaredPosition, this, spec.SpecialConstraint, spec.Variance, null) {
432 BaseType = spec.BaseType,
433 InterfacesDefined = spec.InterfacesDefined,
434 TypeArguments = spec.TypeArguments
435 };
436 }
437
438 #region Properties
439
440 public override AttributeTargets AttributeTargets {
441 get {
442 return AttributeTargets.GenericParameter;
443 }
444 }
445
446 public Constraints Constraints {
447 get {
448 return constraints;
449 }
450 set {
451 constraints = value;
452 }
453 }
454
455 public IAssemblyDefinition DeclaringAssembly {
456 get {
457 return Module.DeclaringAssembly;
458 }
459 }
460
461 public override string DocCommentHeader {
462 get {
463 throw new InvalidOperationException (
464 "Unexpected attempt to get doc comment from " + this.GetType ());
465 }
466 }
467
468 bool ITypeDefinition.IsComImport {
469 get {
470 return false;
471 }
472 }
473
474 bool ITypeDefinition.IsPartial {
475 get {
476 return false;
477 }
478 }
479
480 public bool IsMethodTypeParameter {
481 get {
482 return spec.IsMethodOwned;
483 }
484 }
485
486 bool ITypeDefinition.IsTypeForwarder {
487 get {
488 return false;
489 }
490 }
491
492 bool ITypeDefinition.IsCyclicTypeForwarder {
493 get {
494 return false;
495 }
496 }
497
498 public string Name {
499 get {
500 return MemberName.Name;
501 }
502 }
503
504 public string Namespace {
505 get {
506 return null;
507 }
508 }
509
510 public TypeParameterSpec Type {
511 get {
512 return spec;
513 }
514 }
515
516 public int TypeParametersCount {
517 get {
518 return 0;
519 }
520 }
521
522 public TypeParameterSpec[] TypeParameters {
523 get {
524 return null;
525 }
526 }
527
528 public override string[] ValidAttributeTargets {
529 get {
530 return attribute_target;
531 }
532 }
533
534 public Variance Variance {
535 get {
536 return spec.Variance;
537 }
538 }
539
540 public VarianceDecl VarianceDecl { get; private set; }
541
542 #endregion
543
544 //
545 // This is called for each part of a partial generic type definition.
546 //
547 // If partial type parameters constraints are not null and we don't
548 // already have constraints they become our constraints. If we already
549 // have constraints, we must check that they're same.
550 //
551 public bool AddPartialConstraints (TypeDefinition part, TypeParameter tp)
552 {
553 if (builder == null)
554 throw new InvalidOperationException ();
555
556 var new_constraints = tp.constraints;
557 if (new_constraints == null)
558 return true;
559
560 // TODO: could create spec only
561 //tp.Define (null, -1, part.Definition);
562 tp.spec.DeclaringType = part.Definition;
563 if (!tp.ResolveConstraints (part))
564 return false;
565
566 if (constraints != null)
567 return spec.HasSameConstraintsDefinition (tp.Type);
568
569 // Copy constraint from resolved part to partial container
570 spec.SpecialConstraint = tp.spec.SpecialConstraint;
571 spec.InterfacesDefined = tp.spec.InterfacesDefined;
572 spec.TypeArguments = tp.spec.TypeArguments;
573 spec.BaseType = tp.spec.BaseType;
574
575 return true;
576 }
577
578 public override void ApplyAttributeBuilder (Attribute a, MethodSpec ctor, byte[] cdata, PredefinedAttributes pa)
579 {
580 builder.SetCustomAttribute ((ConstructorInfo) ctor.GetMetaInfo (), cdata);
581 }
582
583 public void CheckGenericConstraints (bool obsoleteCheck)
584 {
585 if (constraints != null)
586 constraints.CheckGenericConstraints (this, obsoleteCheck);
587 }
588
589 public TypeParameter CreateHoistedCopy (TypeSpec declaringSpec)
590 {
591 return new TypeParameter (spec, declaringSpec, MemberName, null);
592 }
593
594 public override bool Define ()
595 {
596 return true;
597 }
598
599 //
600 // This is the first method which is called during the resolving
601 // process; we're called immediately after creating the type parameters
602 // with SRE (by calling `DefineGenericParameters()' on the TypeBuilder /
603 // MethodBuilder).
604 //
605 public void Create (TypeSpec declaringType, TypeContainer parent)
606 {
607 if (builder != null)
608 throw new InternalErrorException ();
609
610 // Needed to get compiler reference
611 this.Parent = parent;
612 spec.DeclaringType = declaringType;
613 }
614
615 public void Define (GenericTypeParameterBuilder type)
616 {
617 this.builder = type;
618 spec.SetMetaInfo (type);
619 }
620
621 public void Define (TypeParameter tp)
622 {
623 builder = tp.builder;
624 }
625
626 public void EmitConstraints (GenericTypeParameterBuilder builder)
627 {
628 var attr = GenericParameterAttributes.None;
629 if (spec.Variance == Variance.Contravariant)
630 attr |= GenericParameterAttributes.Contravariant;
631 else if (spec.Variance == Variance.Covariant)
632 attr |= GenericParameterAttributes.Covariant;
633
634 if (spec.HasSpecialClass)
635 attr |= GenericParameterAttributes.ReferenceTypeConstraint;
636 else if (spec.HasSpecialStruct)
637 attr |= GenericParameterAttributes.NotNullableValueTypeConstraint | GenericParameterAttributes.DefaultConstructorConstraint;
638
639 if (spec.HasSpecialConstructor)
640 attr |= GenericParameterAttributes.DefaultConstructorConstraint;
641
642 if (spec.BaseType.BuiltinType != BuiltinTypeSpec.Type.Object)
643 builder.SetBaseTypeConstraint (spec.BaseType.GetMetaInfo ());
644
645 if (spec.InterfacesDefined != null)
646 builder.SetInterfaceConstraints (spec.InterfacesDefined.Select (l => l.GetMetaInfo ()).ToArray ());
647
648 if (spec.TypeArguments != null) {
649 var meta_constraints = new List<MetaType> (spec.TypeArguments.Length);
650 foreach (var c in spec.TypeArguments) {
651 //
652 // Inflated type parameters can collide with base type constraint, don't
653 // emit any such type parameter.
654 //
655 if (c.IsClass && spec.BaseType.BuiltinType != BuiltinTypeSpec.Type.Object)
656 continue;
657
658 meta_constraints.Add (c.GetMetaInfo ());
659 }
660
661 builder.SetInterfaceConstraints (meta_constraints.ToArray ());
662 }
663
664 builder.SetGenericParameterAttributes (attr);
665 }
666
667 public override void Emit ()
668 {
669 EmitConstraints (builder);
670
671 if (OptAttributes != null)
672 OptAttributes.Emit ();
673
674 base.Emit ();
675 }
676
677 public void ErrorInvalidVariance (IMemberContext mc, Variance expected)
678 {
679 Report.SymbolRelatedToPreviousError (mc.CurrentMemberDefinition);
680 string input_variance = Variance == Variance.Contravariant ? "contravariant" : "covariant";
681 string gtype_variance;
682 switch (expected) {
683 case Variance.Contravariant: gtype_variance = "contravariantly"; break;
684 case Variance.Covariant: gtype_variance = "covariantly"; break;
685 default: gtype_variance = "invariantly"; break;
686 }
687
688 Delegate d = mc as Delegate;
689 string parameters = d != null ? d.Parameters.GetSignatureForError () : "";
690
691 Report.Error (1961, Location,
692 "The {2} type parameter `{0}' must be {3} valid on `{1}{4}'",
693 GetSignatureForError (), mc.GetSignatureForError (), input_variance, gtype_variance, parameters);
694 }
695
696 public TypeSpec GetAttributeCoClass ()
697 {
698 return null;
699 }
700
701 public string GetAttributeDefaultMember ()
702 {
703 throw new NotSupportedException ();
704 }
705
706 public AttributeUsageAttribute GetAttributeUsage (PredefinedAttribute pa)
707 {
708 throw new NotSupportedException ();
709 }
710
711 public override string GetSignatureForDocumentation ()
712 {
713 throw new NotImplementedException ();
714 }
715
716 public override string GetSignatureForError ()
717 {
718 return MemberName.Name;
719 }
720
721 bool ITypeDefinition.IsInternalAsPublic (IAssemblyDefinition assembly)
722 {
723 return spec.MemberDefinition.DeclaringAssembly == assembly;
724 }
725
726 public void LoadMembers (TypeSpec declaringType, bool onlyTypes, ref MemberCache cache)
727 {
728 throw new NotSupportedException ("Not supported for compiled definition");
729 }
730
731 //
732 // Resolves all type parameter constraints
733 //
734 public bool ResolveConstraints (IMemberContext context)
735 {
736 if (constraints != null)
737 return constraints.Resolve (context, this);
738
739 if (spec.BaseType == null)
740 spec.BaseType = context.Module.Compiler.BuiltinTypes.Object;
741
742 return true;
743 }
744
745 public override bool IsClsComplianceRequired ()
746 {
747 return false;
748 }
749
750 public new void VerifyClsCompliance ()
751 {
752 if (constraints != null)
753 constraints.VerifyClsCompliance (Report);
754 }
755
756 public void WarningParentNameConflict (TypeParameter conflict)
757 {
758 conflict.Report.SymbolRelatedToPreviousError (conflict.Location, null);
759 conflict.Report.Warning (693, 3, Location,
760 "Type parameter `{0}' has the same name as the type parameter from outer type `{1}'",
761 GetSignatureForError (), conflict.CurrentType.GetSignatureForError ());
762 }
763 }
764
765 [System.Diagnostics.DebuggerDisplay ("{DisplayDebugInfo()}")]
766 public class TypeParameterSpec : TypeSpec
767 {
768 public static readonly new TypeParameterSpec[] EmptyTypes = new TypeParameterSpec[0];
769
770 Variance variance;
771 SpecialConstraint spec;
772 int tp_pos;
773 TypeSpec[] targs;
774 TypeSpec[] ifaces_defined;
775 TypeSpec effective_base;
776 MemberCache interface_cache;
777
778 //
779 // Creates type owned type parameter
780 //
781 public TypeParameterSpec (TypeSpec declaringType, int index, ITypeDefinition definition, SpecialConstraint spec, Variance variance, MetaType info)
782 : base (MemberKind.TypeParameter, declaringType, definition, info, Modifiers.PUBLIC)
783 {
784 this.variance = variance;
785 this.spec = spec;
786 state &= ~StateFlags.Obsolete_Undetected;
787 tp_pos = index;
788 }
789
790 //
791 // Creates method owned type parameter
792 //
793 public TypeParameterSpec (int index, ITypeDefinition definition, SpecialConstraint spec, Variance variance, MetaType info)
794 : this (null, index, definition, spec, variance, info)
795 {
796 }
797
798 #region Properties
799
800 public int DeclaredPosition {
801 get {
802 return tp_pos;
803 }
804 set {
805 tp_pos = value;
806 }
807 }
808
809 public bool HasSpecialConstructor {
810 get {
811 return (spec & SpecialConstraint.Constructor) != 0;
812 }
813 }
814
815 public bool HasSpecialClass {
816 get {
817 return (spec & SpecialConstraint.Class) != 0;
818 }
819 }
820
821 public bool HasSpecialStruct {
822 get {
823 return (spec & SpecialConstraint.Struct) != 0;
824 }
825 }
826
827 public bool HasAnyTypeConstraint {
828 get {
829 return (spec & (SpecialConstraint.Class | SpecialConstraint.Struct)) != 0 || ifaces != null || targs != null || HasTypeConstraint;
830 }
831 }
832
833 public bool HasTypeConstraint {
834 get {
835 var bt = BaseType.BuiltinType;
836 return bt != BuiltinTypeSpec.Type.Object && bt != BuiltinTypeSpec.Type.ValueType;
837 }
838 }
839
840 public override IList<TypeSpec> Interfaces {
841 get {
842 if ((state & StateFlags.InterfacesExpanded) == 0) {
843 if (ifaces != null) {
844 if (ifaces_defined == null)
845 ifaces_defined = ifaces.ToArray ();
846
847 for (int i = 0; i < ifaces_defined.Length; ++i ) {
848 var iface_type = ifaces_defined[i];
849 var td = iface_type.MemberDefinition as TypeDefinition;
850 if (td != null)
851 td.DoExpandBaseInterfaces ();
852
853 if (iface_type.Interfaces != null) {
854 for (int ii = 0; ii < iface_type.Interfaces.Count; ++ii) {
855 var ii_iface_type = iface_type.Interfaces [ii];
856 AddInterface (ii_iface_type);
857 }
858 }
859 }
860 } else if (ifaces_defined == null) {
861 ifaces_defined = ifaces == null ? TypeSpec.EmptyTypes : ifaces.ToArray ();
862 }
863
864 //
865 // Include all base type interfaces too, see ImportTypeBase for details
866 //
867 if (BaseType != null) {
868 var td = BaseType.MemberDefinition as TypeDefinition;
869 if (td != null)
870 td.DoExpandBaseInterfaces ();
871
872 if (BaseType.Interfaces != null) {
873 foreach (var iface in BaseType.Interfaces) {
874 AddInterface (iface);
875 }
876 }
877 }
878
879 state |= StateFlags.InterfacesExpanded;
880 }
881
882 return ifaces;
883 }
884 }
885
886 public MemberCache InterfaceCache {
887 get {
888 return interface_cache;
889 }
890 }
891
892 //
893 // Unexpanded interfaces list
894 //
895 public TypeSpec[] InterfacesDefined {
896 get {
897 if (ifaces_defined == null) {
898 ifaces_defined = ifaces == null ? TypeSpec.EmptyTypes : ifaces.ToArray ();
899 }
900
901 return ifaces_defined.Length == 0 ? null : ifaces_defined;
902 }
903 set {
904 ifaces_defined = value;
905 if (value != null && value.Length != 0)
906 ifaces = new List<TypeSpec> (value);
907 }
908 }
909
910 public bool IsConstrained {
911 get {
912 return spec != SpecialConstraint.None || ifaces != null || targs != null || HasTypeConstraint;
913 }
914 }
915
916 //
917 // Returns whether the type parameter is known to be a reference type
918 //
919 public new bool IsReferenceType {
920 get {
921 if ((spec & (SpecialConstraint.Class | SpecialConstraint.Struct)) != 0)
922 return (spec & SpecialConstraint.Class) != 0;
923
924 //
925 // Full check is needed (see IsValueType for details)
926 //
927 if (HasTypeConstraint && TypeSpec.IsReferenceType (BaseType))
928 return true;
929
930 if (targs != null) {
931 foreach (var ta in targs) {
932 //
933 // Secondary special constraints are ignored (I am not sure why)
934 //
935 var tp = ta as TypeParameterSpec;
936 if (tp != null && (tp.spec & (SpecialConstraint.Class | SpecialConstraint.Struct)) != 0)
937 continue;
938
939 if (TypeSpec.IsReferenceType (ta))
940 return true;
941 }
942 }
943
944 return false;
945 }
946 }
947
948 //
949 // Returns whether the type parameter is known to be a value type
950 //
951 public new bool IsValueType {
952 get {
953 //
954 // Even if structs/enums cannot be used directly as constraints
955 // they can apear as constraint type when inheriting base constraint
956 // which has dependant type parameter constraint which has been
957 // inflated using value type
958 //
959 // class A : B<int> { override void Foo<U> () {} }
960 // class B<T> { virtual void Foo<U> () where U : T {} }
961 //
962 if (HasSpecialStruct)
963 return true;
964
965 if (targs != null) {
966 foreach (var ta in targs) {
967 if (TypeSpec.IsValueType (ta))
968 return true;
969 }
970 }
971
972 return false;
973 }
974 }
975
976 public override string Name {
977 get {
978 return definition.Name;
979 }
980 }
981
982 public bool IsMethodOwned {
983 get {
984 return DeclaringType == null;
985 }
986 }
987
988 public SpecialConstraint SpecialConstraint {
989 get {
990 return spec;
991 }
992 set {
993 spec = value;
994 }
995 }
996
997 //
998 // Types used to inflate the generic type
999 //
1000 public new TypeSpec[] TypeArguments {
1001 get {
1002 return targs;
1003 }
1004 set {
1005 targs = value;
1006 }
1007 }
1008
1009 public Variance Variance {
1010 get {
1011 return variance;
1012 }
1013 }
1014
1015 #endregion
1016
1017 public string DisplayDebugInfo ()
1018 {
1019 var s = GetSignatureForError ();
1020 return IsMethodOwned ? s + "!!" : s + "!";
1021 }
1022
1023 //
1024 // Finds effective base class. The effective base class is always a class-type
1025 //
1026 public TypeSpec GetEffectiveBase ()
1027 {
1028 if (HasSpecialStruct)
1029 return BaseType;
1030
1031 //
1032 // If T has a class-type constraint C but no type-parameter constraints, its effective base class is C
1033 //
1034 if (BaseType != null && targs == null) {
1035 //
1036 // If T has a constraint V that is a value-type, use instead the most specific base type of V that is a class-type.
1037 //
1038 // LAMESPEC: Is System.ValueType always the most specific base type in this case?
1039 //
1040 // Note: This can never happen in an explicitly given constraint, but may occur when the constraints of a generic method
1041 // are implicitly inherited by an overriding method declaration or an explicit implementation of an interface method.
1042 //
1043 return BaseType.IsStruct ? BaseType.BaseType : BaseType;
1044 }
1045
1046 if (effective_base != null)
1047 return effective_base;
1048
1049 var types = new TypeSpec [HasTypeConstraint ? targs.Length + 1 : targs.Length];
1050
1051 for (int i = 0; i < targs.Length; ++i) {
1052 var t = targs [i];
1053
1054 // Same issue as above, inherited constraints can be of struct type
1055 if (t.IsStruct) {
1056 types [i] = t.BaseType;
1057 continue;
1058 }
1059
1060 var tps = t as TypeParameterSpec;
1061 types [i] = tps != null ? tps.GetEffectiveBase () : t;
1062 }
1063
1064 if (HasTypeConstraint)
1065 types [types.Length - 1] = BaseType;
1066
1067 return effective_base = Convert.FindMostEncompassedType (types);
1068 }
1069
1070 public override string GetSignatureForDocumentation (bool explicitName)
1071 {
1072 if (explicitName)
1073 return Name;
1074
1075 var prefix = IsMethodOwned ? "``" : "`";
1076 return prefix + DeclaredPosition;
1077 }
1078
1079 public override string GetSignatureForError ()
1080 {
1081 return Name;
1082 }
1083
1084 //
1085 // Constraints have to match by definition but not position, used by
1086 // partial classes or methods
1087 //
1088 public bool HasSameConstraintsDefinition (TypeParameterSpec other)
1089 {
1090 if (spec != other.spec)
1091 return false;
1092
1093 if (BaseType != other.BaseType)
1094 return false;
1095
1096 if (!TypeSpecComparer.Override.IsSame (InterfacesDefined, other.InterfacesDefined))
1097 return false;
1098
1099 if (!TypeSpecComparer.Override.IsSame (targs, other.targs))
1100 return false;
1101
1102 return true;
1103 }
1104
1105 //
1106 // Constraints have to match by using same set of types, used by
1107 // implicit interface implementation
1108 //
1109 public bool HasSameConstraintsImplementation (TypeParameterSpec other)
1110 {
1111 if (spec != other.spec)
1112 return false;
1113
1114 //
1115 // It can be same base type or inflated type parameter
1116 //
1117 // interface I<T> { void Foo<U> where U : T; }
1118 // class A : I<int> { void Foo<X> where X : int {} }
1119 //
1120 bool found;
1121 if (!TypeSpecComparer.Override.IsEqual (BaseType, other.BaseType)) {
1122 found = false;
1123 if (other.targs != null) {
1124 foreach (var otarg in other.targs) {
1125 if (TypeSpecComparer.Override.IsEqual (BaseType, otarg)) {
1126 found = true;
1127 break;
1128 }
1129 }
1130 } else if (targs != null) {
1131 foreach (var targ in targs) {
1132 if (TypeSpecComparer.Override.IsEqual (targ, other.BaseType)) {
1133 found = true;
1134 break;
1135 }
1136 }
1137 }
1138
1139 if (!found)
1140 return false;
1141 }
1142
1143 // Check interfaces implementation -> definition
1144 if (InterfacesDefined != null) {
1145 //
1146 // Iterate over inflated interfaces
1147 //
1148 foreach (var iface in InterfacesDefined) {
1149 found = false;
1150 if (other.InterfacesDefined != null) {
1151 foreach (var oiface in other.Interfaces) {
1152 if (TypeSpecComparer.Override.IsEqual (iface, oiface)) {
1153 found = true;
1154 break;
1155 }
1156 }
1157 }
1158
1159 if (found)
1160 continue;
1161
1162 if (other.targs != null) {
1163 foreach (var otarg in other.targs) {
1164 if (TypeSpecComparer.Override.IsEqual (iface, otarg)) {
1165 found = true;
1166 break;
1167 }
1168 }
1169 }
1170
1171 if (!found)
1172 return false;
1173 }
1174 }
1175
1176 // Check interfaces implementation <- definition
1177 if (other.InterfacesDefined != null) {
1178 //
1179 // Iterate over inflated interfaces
1180 //
1181 foreach (var oiface in other.InterfacesDefined) {
1182 found = false;
1183
1184 if (InterfacesDefined != null) {
1185 foreach (var iface in Interfaces) {
1186 if (TypeSpecComparer.Override.IsEqual (iface, oiface)) {
1187 found = true;
1188 break;
1189 }
1190 }
1191 } else if (targs != null) {
1192 foreach (var targ in targs) {
1193 if (TypeSpecComparer.Override.IsEqual (targ, oiface)) {
1194 found = true;
1195 break;
1196 }
1197 }
1198 }
1199
1200 if (!found)
1201 return false;
1202 }
1203 }
1204
1205 // Check type parameters implementation -> definition
1206 if (targs != null) {
1207 foreach (var targ in targs) {
1208 found = false;
1209
1210 if (other.targs != null) {
1211 foreach (var otarg in other.targs) {
1212 if (TypeSpecComparer.Override.IsEqual (targ, otarg)) {
1213 found = true;
1214 break;
1215 }
1216 }
1217 }
1218
1219 if (other.InterfacesDefined != null && !found) {
1220 foreach (var iface in other.Interfaces) {
1221 if (TypeSpecComparer.Override.IsEqual (iface, targ)) {
1222 found = true;
1223 break;
1224 }
1225 }
1226 }
1227
1228 if (!found)
1229 found = TypeSpecComparer.Override.IsEqual (targ, other.BaseType);
1230
1231 if (!found)
1232 return false;
1233 }
1234 }
1235
1236 // Check type parameters implementation <- definition
1237 if (other.targs != null) {
1238 foreach (var otarg in other.targs) {
1239 // Ignore inflated type arguments, were checked above
1240 if (!otarg.IsGenericParameter)
1241 continue;
1242
1243 if (targs == null)
1244 return false;
1245
1246 found = false;
1247 foreach (var targ in targs) {
1248 if (TypeSpecComparer.Override.IsEqual (targ, otarg)) {
1249 found = true;
1250 break;
1251 }
1252 }
1253
1254 if (!found)
1255 return false;
1256 }
1257 }
1258
1259 return true;
1260 }
1261
1262 public static TypeParameterSpec[] InflateConstraints (TypeParameterInflator inflator, TypeParameterSpec[] tparams)
1263 {
1264 return InflateConstraints (tparams, l => l, inflator);
1265 }
1266
1267 public static TypeParameterSpec[] InflateConstraints<T> (TypeParameterSpec[] tparams, Func<T, TypeParameterInflator> inflatorFactory, T arg)
1268 {
1269 TypeParameterSpec[] constraints = null;
1270 TypeParameterInflator? inflator = null;
1271
1272 for (int i = 0; i < tparams.Length; ++i) {
1273 var tp = tparams[i];
1274 if (tp.HasTypeConstraint || tp.InterfacesDefined != null || tp.TypeArguments != null) {
1275 if (constraints == null) {
1276 constraints = new TypeParameterSpec[tparams.Length];
1277 Array.Copy (tparams, constraints, constraints.Length);
1278 }
1279
1280 //
1281 // Using a factory to avoid possibly expensive inflator build up
1282 //
1283 if (inflator == null)
1284 inflator = inflatorFactory (arg);
1285
1286 constraints[i] = (TypeParameterSpec) constraints[i].InflateMember (inflator.Value);
1287 }
1288 }
1289
1290 if (constraints == null)
1291 constraints = tparams;
1292
1293 return constraints;
1294 }
1295
1296 public void InflateConstraints (TypeParameterInflator inflator, TypeParameterSpec tps)
1297 {
1298 tps.BaseType = inflator.Inflate (BaseType);
1299
1300 var defined = InterfacesDefined;
1301 if (defined != null) {
1302 tps.ifaces_defined = new TypeSpec[defined.Length];
1303 for (int i = 0; i < defined.Length; ++i)
1304 tps.ifaces_defined [i] = inflator.Inflate (defined[i]);
1305 } else if (ifaces_defined == TypeSpec.EmptyTypes) {
1306 tps.ifaces_defined = TypeSpec.EmptyTypes;
1307 }
1308
1309 var ifaces = Interfaces;
1310 if (ifaces != null) {
1311 tps.ifaces = new List<TypeSpec> (ifaces.Count);
1312 for (int i = 0; i < ifaces.Count; ++i)
1313 tps.ifaces.Add (inflator.Inflate (ifaces[i]));
1314 tps.state |= StateFlags.InterfacesExpanded;
1315 }
1316
1317 if (targs != null) {
1318 tps.targs = new TypeSpec[targs.Length];
1319 for (int i = 0; i < targs.Length; ++i)
1320 tps.targs[i] = inflator.Inflate (targs[i]);
1321 }
1322 }
1323
1324 public override MemberSpec InflateMember (TypeParameterInflator inflator)
1325 {
1326 var tps = (TypeParameterSpec) MemberwiseClone ();
1327 #if DEBUG
1328 tps.ID += 1000000;
1329 #endif
1330
1331 InflateConstraints (inflator, tps);
1332 return tps;
1333 }
1334
1335 //
1336 // Populates type parameter members using type parameter constraints
1337 // The trick here is to be called late enough but not too late to
1338 // populate member cache with all members from other types
1339 //
1340 protected override void InitializeMemberCache (bool onlyTypes)
1341 {
1342 cache = new MemberCache ();
1343
1344 if (targs != null) {
1345 foreach (var ta in targs) {
1346 var tps = ta as TypeParameterSpec;
1347 var b_type = tps == null ? ta : tps.GetEffectiveBase ();
1348
1349 //
1350 // Find the most specific type when base type was inflated from base constraints
1351 //
1352 if (b_type != null && !b_type.IsStructOrEnum && TypeSpec.IsBaseClass (b_type, BaseType, false))
1353 BaseType = b_type;
1354 }
1355 }
1356
1357 //
1358 // For a type parameter the membercache is the union of the sets of members of the types
1359 // specified as a primary constraint or secondary constraint
1360 //
1361 bool has_user_base_type = false;
1362 if (BaseType.BuiltinType != BuiltinTypeSpec.Type.Object && BaseType.BuiltinType != BuiltinTypeSpec.Type.ValueType) {
1363 cache.AddBaseType (BaseType);
1364 has_user_base_type = true;
1365 }
1366
1367 if (InterfacesDefined != null) {
1368 var icache = cache;
1369 if (has_user_base_type) {
1370 //
1371 // type-parameter lookup rules are more complicated that other types lookup rules.
1372 // Effective base class and its base types member have priority over interface
1373 // constraints which means we cannot lookup interface members before class members
1374 // hence we setup secondary cache for such cases.
1375 //
1376 interface_cache = new MemberCache ();
1377 icache = interface_cache;
1378 }
1379
1380 foreach (var iface_type in InterfacesDefined) {
1381 icache.AddInterface (iface_type);
1382 }
1383 }
1384
1385 //
1386 // Import interfaces after base type to match behavior from ordinary classes
1387 //
1388 if (targs != null) {
1389 foreach (var ta in targs) {
1390 var tps = ta as TypeParameterSpec;
1391 var ifaces = tps == null ? ta.Interfaces : tps.InterfacesDefined;
1392
1393 if (ifaces != null) {
1394 var icache = cache;
1395 if (has_user_base_type) {
1396 interface_cache = new MemberCache ();
1397 icache = interface_cache;
1398 }
1399
1400 foreach (var iface_type in ifaces) {
1401 icache.AddInterface (iface_type);
1402 }
1403 }
1404 }
1405 }
1406 }
1407
1408 public bool IsConvertibleToInterface (TypeSpec iface)
1409 {
1410 if (Interfaces != null) {
1411 foreach (var t in Interfaces) {
1412 if (t == iface)
1413 return true;
1414 }
1415 }
1416
1417 if (TypeArguments != null) {
1418 foreach (var t in TypeArguments) {
1419 var tps = t as TypeParameterSpec;
1420 if (tps != null) {
1421 if (tps.IsConvertibleToInterface (iface))
1422 return true;
1423
1424 continue;
1425 }
1426
1427 if (t.ImplementsInterface (iface, false))
1428 return true;
1429 }
1430 }
1431
1432 return false;
1433 }
1434
1435 public static bool HasAnyTypeParameterTypeConstrained (IGenericMethodDefinition md)
1436 {
1437 var tps = md.TypeParameters;
1438 for (int i = 0; i < md.TypeParametersCount; ++i) {
1439 if (tps[i].HasAnyTypeConstraint) {
1440 return true;
1441 }
1442 }
1443
1444 return false;
1445 }
1446
1447 public static bool HasAnyTypeParameterConstrained (IGenericMethodDefinition md)
1448 {
1449 var tps = md.TypeParameters;
1450 for (int i = 0; i < md.TypeParametersCount; ++i) {
1451 if (tps[i].IsConstrained) {
1452 return true;
1453 }
1454 }
1455
1456 return false;
1457 }
1458
1459 public bool HasDependencyOn (TypeSpec type)
1460 {
1461 if (TypeArguments != null) {
1462 foreach (var targ in TypeArguments) {
1463 if (TypeSpecComparer.Override.IsEqual (targ, type))
1464 return true;
1465
1466 var tps = targ as TypeParameterSpec;
1467 if (tps != null && tps.HasDependencyOn (type))
1468 return true;
1469 }
1470 }
1471
1472 return false;
1473 }
1474
1475 public override TypeSpec Mutate (TypeParameterMutator mutator)
1476 {
1477 return mutator.Mutate (this);
1478 }
1479 }
1480
1481 public struct TypeParameterInflator
1482 {
1483 readonly TypeSpec type;
1484 readonly TypeParameterSpec[] tparams;
1485 readonly TypeSpec[] targs;
1486 readonly IModuleContext context;
1487
1488 public TypeParameterInflator (TypeParameterInflator nested, TypeSpec type)
1489 : this (nested.context, type, nested.tparams, nested.targs)
1490 {
1491 }
1492
1493 public TypeParameterInflator (IModuleContext context, TypeSpec type, TypeParameterSpec[] tparams, TypeSpec[] targs)
1494 {
1495 if (tparams.Length != targs.Length)
1496 throw new ArgumentException ("Invalid arguments");
1497
1498 this.context = context;
1499 this.tparams = tparams;
1500 this.targs = targs;
1501 this.type = type;
1502 }
1503
1504 #region Properties
1505
1506 public IModuleContext Context {
1507 get {
1508 return context;
1509 }
1510 }
1511
1512 public TypeSpec TypeInstance {
1513 get {
1514 return type;
1515 }
1516 }
1517
1518 //
1519 // Type parameters to inflate
1520 //
1521 public TypeParameterSpec[] TypeParameters {
1522 get {
1523 return tparams;
1524 }
1525 }
1526
1527 #endregion
1528
1529 public TypeSpec Inflate (TypeSpec type)
1530 {
1531 var tp = type as TypeParameterSpec;
1532 if (tp != null)
1533 return Inflate (tp);
1534
1535 var ec = type as ElementTypeSpec;
1536 if (ec != null) {
1537 var et = Inflate (ec.Element);
1538 if (et != ec.Element) {
1539 var ac = ec as ArrayContainer;
1540 if (ac != null)
1541 return ArrayContainer.MakeType (context.Module, et, ac.Rank);
1542
1543 if (ec is PointerContainer)
1544 return PointerContainer.MakeType (context.Module, et);
1545
1546 throw new NotImplementedException ();
1547 }
1548
1549 return ec;
1550 }
1551
1552 if (type.Kind == MemberKind.MissingType)
1553 return type;
1554
1555 //
1556 // When inflating a nested type, inflate its parent first
1557 // in case it's using same type parameters (was inflated within the type)
1558 //
1559 TypeSpec[] targs;
1560 int i = 0;
1561 if (type.IsNested) {
1562 var parent = Inflate (type.DeclaringType);
1563
1564 //
1565 // Keep the inflated type arguments
1566 //
1567 targs = type.TypeArguments;
1568
1569 //
1570 // When inflating imported nested type used inside same declaring type, we get TypeSpec
1571 // because the import cache helps us to catch it. However, that means we have to look at
1572 // type definition to get type argument (they are in fact type parameter in this case)
1573 //
1574 if (targs.Length == 0 && type.Arity > 0)
1575 targs = type.MemberDefinition.TypeParameters;
1576
1577 //
1578 // Parent was inflated, find the same type on inflated type
1579 // to use same cache for nested types on same generic parent
1580 //
1581 type = MemberCache.FindNestedType (parent, type.Name, type.Arity, false);
1582
1583 //
1584 // Handle the tricky case where parent shares local type arguments
1585 // which means inflating inflated type
1586 //
1587 // class Test<T> {
1588 // public static Nested<T> Foo () { return null; }
1589 //
1590 // public class Nested<U> {}
1591 // }
1592 //
1593 // return type of Test<string>.Foo() has to be Test<string>.Nested<string>
1594 //
1595 if (targs.Length > 0) {
1596 var inflated_targs = new TypeSpec[targs.Length];
1597 for (; i < targs.Length; ++i)
1598 inflated_targs[i] = Inflate (targs[i]);
1599
1600 type = type.MakeGenericType (context, inflated_targs);
1601 }
1602
1603 return type;
1604 }
1605
1606 // Nothing to do for non-generic type
1607 if (type.Arity == 0)
1608 return type;
1609
1610 targs = new TypeSpec[type.Arity];
1611
1612 //
1613 // Inflating using outside type arguments, var v = new Foo<int> (), class Foo<T> {}
1614 //
1615 if (type is InflatedTypeSpec) {
1616 for (; i < targs.Length; ++i)
1617 targs[i] = Inflate (type.TypeArguments[i]);
1618
1619 type = type.GetDefinition ();
1620 } else {
1621 //
1622 // Inflating parent using inside type arguments, class Foo<T> { ITest<T> foo; }
1623 //
1624 var args = type.MemberDefinition.TypeParameters;
1625 foreach (var ds_tp in args)
1626 targs[i++] = Inflate (ds_tp);
1627 }
1628
1629 return type.MakeGenericType (context, targs);
1630 }
1631
1632 public TypeSpec Inflate (TypeParameterSpec tp)
1633 {
1634 for (int i = 0; i < tparams.Length; ++i)
1635 if (tparams [i] == tp)
1636 return targs[i];
1637
1638 // This can happen when inflating nested types
1639 // without type arguments specified
1640 return tp;
1641 }
1642 }
1643
1644 //
1645 // Before emitting any code we have to change all MVAR references to VAR
1646 // when the method is of generic type and has hoisted variables
1647 //
1648 public class TypeParameterMutator
1649 {
1650 readonly TypeParameters mvar;
1651 readonly TypeParameters var;
1652 readonly TypeParameterSpec[] src;
1653 Dictionary<TypeSpec, TypeSpec> mutated_typespec;
1654
1655 public TypeParameterMutator (TypeParameters mvar, TypeParameters var)
1656 {
1657 if (mvar.Count != var.Count)
1658 throw new ArgumentException ();
1659
1660 this.mvar = mvar;
1661 this.var = var;
1662 }
1663
1664 public TypeParameterMutator (TypeParameterSpec[] srcVar, TypeParameters destVar)
1665 {
1666 if (srcVar.Length != destVar.Count)
1667 throw new ArgumentException ();
1668
1669 this.src = srcVar;
1670 this.var = destVar;
1671 }
1672
1673 #region Properties
1674
1675 public TypeParameters MethodTypeParameters {
1676 get {
1677 return mvar;
1678 }
1679 }
1680
1681 #endregion
1682
1683 public static TypeSpec GetMemberDeclaringType (TypeSpec type)
1684 {
1685 if (type is InflatedTypeSpec) {
1686 if (type.DeclaringType == null)
1687 return type.GetDefinition ();
1688
1689 var parent = GetMemberDeclaringType (type.DeclaringType);
1690 type = MemberCache.GetMember<TypeSpec> (parent, type);
1691 }
1692
1693 return type;
1694 }
1695
1696 public TypeSpec Mutate (TypeSpec ts)
1697 {
1698 TypeSpec value;
1699 if (mutated_typespec != null && mutated_typespec.TryGetValue (ts, out value))
1700 return value;
1701
1702 value = ts.Mutate (this);
1703 if (mutated_typespec == null)
1704 mutated_typespec = new Dictionary<TypeSpec, TypeSpec> ();
1705
1706 mutated_typespec.Add (ts, value);
1707 return value;
1708 }
1709
1710 public TypeParameterSpec Mutate (TypeParameterSpec tp)
1711 {
1712 if (mvar != null) {
1713 for (int i = 0; i < mvar.Count; ++i) {
1714 if (mvar[i].Type == tp)
1715 return var[i].Type;
1716 }
1717 } else {
1718 for (int i = 0; i < src.Length; ++i) {
1719 if (src[i] == tp)
1720 return var[i].Type;
1721 }
1722 }
1723
1724 return tp;
1725 }
1726
1727 public TypeSpec[] Mutate (TypeSpec[] targs)
1728 {
1729 TypeSpec[] mutated = new TypeSpec[targs.Length];
1730 bool changed = false;
1731 for (int i = 0; i < targs.Length; ++i) {
1732 mutated[i] = Mutate (targs[i]);
1733 changed |= targs[i] != mutated[i];
1734 }
1735
1736 return changed ? mutated : targs;
1737 }
1738 }
1739
1740 /// <summary>
1741 /// A TypeExpr which already resolved to a type parameter.
1742 /// </summary>
1743 public class TypeParameterExpr : TypeExpression
1744 {
1745 public TypeParameterExpr (TypeParameter type_parameter, Location loc)
1746 : base (type_parameter.Type, loc)
1747 {
1748 this.eclass = ExprClass.TypeParameter;
1749 }
1750 }
1751
1752 public class InflatedTypeSpec : TypeSpec
1753 {
1754 TypeSpec[] targs;
1755 TypeParameterSpec[] constraints;
1756 readonly TypeSpec open_type;
1757 readonly IModuleContext context;
1758
1759 public InflatedTypeSpec (IModuleContext context, TypeSpec openType, TypeSpec declaringType, TypeSpec[] targs)
1760 : base (openType.Kind, declaringType, openType.MemberDefinition, null, openType.Modifiers)
1761 {
1762 if (targs == null)
1763 throw new ArgumentNullException ("targs");
1764
1765 this.state &= ~SharedStateFlags;
1766 this.state |= (openType.state & SharedStateFlags);
1767
1768 this.context = context;
1769 this.open_type = openType;
1770 this.targs = targs;
1771
1772 foreach (var arg in targs) {
1773 if (arg.HasDynamicElement || arg.BuiltinType == BuiltinTypeSpec.Type.Dynamic) {
1774 state |= StateFlags.HasDynamicElement;
1775 break;
1776 }
1777 }
1778
1779 if (open_type.Kind == MemberKind.MissingType)
1780 MemberCache = MemberCache.Empty;
1781
1782 if ((open_type.Modifiers & Modifiers.COMPILER_GENERATED) != 0)
1783 state |= StateFlags.ConstraintsChecked;
1784 }
1785
1786 #region Properties
1787
1788 public override TypeSpec BaseType {
1789 get {
1790 if (cache == null || (state & StateFlags.PendingBaseTypeInflate) != 0)
1791 InitializeMemberCache (true);
1792
1793 return base.BaseType;
1794 }
1795 }
1796
1797 //
1798 // Inflated type parameters with constraints array, mapping with type arguments is based on index
1799 //
1800 public TypeParameterSpec[] Constraints {
1801 get {
1802 if (constraints == null) {
1803 constraints = TypeParameterSpec.InflateConstraints (MemberDefinition.TypeParameters, l => l.CreateLocalInflator (context), this);
1804 }
1805
1806 return constraints;
1807 }
1808 }
1809
1810 //
1811 // Used to cache expensive constraints validation on constructed types
1812 //
1813 public bool HasConstraintsChecked {
1814 get {
1815 return (state & StateFlags.ConstraintsChecked) != 0;
1816 }
1817 set {
1818 state = value ? state | StateFlags.ConstraintsChecked : state & ~StateFlags.ConstraintsChecked;
1819 }
1820 }
1821
1822 public override IList<TypeSpec> Interfaces {
1823 get {
1824 if (cache == null)
1825 InitializeMemberCache (true);
1826
1827 return base.Interfaces;
1828 }
1829 }
1830
1831 public override bool IsExpressionTreeType {
1832 get {
1833 return (open_type.state & StateFlags.InflatedExpressionType) != 0;
1834 }
1835 }
1836
1837 public override bool IsArrayGenericInterface {
1838 get {
1839 return (open_type.state & StateFlags.GenericIterateInterface) != 0;
1840 }
1841 }
1842
1843 public override bool IsGenericTask {
1844 get {
1845 return (open_type.state & StateFlags.GenericTask) != 0;
1846 }
1847 }
1848
1849 public override bool IsNullableType {
1850 get {
1851 return (open_type.state & StateFlags.InflatedNullableType) != 0;
1852 }
1853 }
1854
1855 //
1856 // Types used to inflate the generic type
1857 //
1858 public override TypeSpec[] TypeArguments {
1859 get {
1860 return targs;
1861 }
1862 }
1863
1864 #endregion
1865
1866 public override bool AddInterface (TypeSpec iface)
1867 {
1868 var inflator = CreateLocalInflator (context);
1869 iface = inflator.Inflate (iface);
1870 if (iface == null)
1871 return false;
1872
1873 return base.AddInterface (iface);
1874 }
1875
1876 public static bool ContainsTypeParameter (TypeSpec type)
1877 {
1878 if (type.Kind == MemberKind.TypeParameter)
1879 return true;
1880
1881 var element_container = type as ElementTypeSpec;
1882 if (element_container != null)
1883 return ContainsTypeParameter (element_container.Element);
1884
1885 foreach (var t in type.TypeArguments) {
1886 if (ContainsTypeParameter (t)) {
1887 return true;
1888 }
1889 }
1890
1891 return false;
1892 }
1893
1894 public TypeParameterInflator CreateLocalInflator (IModuleContext context)
1895 {
1896 TypeParameterSpec[] tparams_full;
1897 TypeSpec[] targs_full = targs;
1898 if (IsNested) {
1899 //
1900 // Special case is needed when we are inflating an open type (nested type definition)
1901 // on inflated parent. Consider following case
1902 //
1903 // Foo<T>.Bar<U> => Foo<string>.Bar<U>
1904 //
1905 // Any later inflation of Foo<string>.Bar<U> has to also inflate T if used inside Bar<U>
1906 //
1907 List<TypeSpec> merged_targs = null;
1908 List<TypeParameterSpec> merged_tparams = null;
1909
1910 var type = DeclaringType;
1911
1912 do {
1913 if (type.TypeArguments.Length > 0) {
1914 if (merged_targs == null) {
1915 merged_targs = new List<TypeSpec> ();
1916 merged_tparams = new List<TypeParameterSpec> ();
1917 if (targs.Length > 0) {
1918 merged_targs.AddRange (targs);
1919 merged_tparams.AddRange (open_type.MemberDefinition.TypeParameters);
1920 }
1921 }
1922 merged_tparams.AddRange (type.MemberDefinition.TypeParameters);
1923 merged_targs.AddRange (type.TypeArguments);
1924 }
1925 type = type.DeclaringType;
1926 } while (type != null);
1927
1928 if (merged_targs != null) {
1929 // Type arguments are not in the right order but it should not matter in this case
1930 targs_full = merged_targs.ToArray ();
1931 tparams_full = merged_tparams.ToArray ();
1932 } else if (targs.Length == 0) {
1933 tparams_full = TypeParameterSpec.EmptyTypes;
1934 } else {
1935 tparams_full = open_type.MemberDefinition.TypeParameters;
1936 }
1937 } else if (targs.Length == 0) {
1938 tparams_full = TypeParameterSpec.EmptyTypes;
1939 } else {
1940 tparams_full = open_type.MemberDefinition.TypeParameters;
1941 }
1942
1943 return new TypeParameterInflator (context, this, tparams_full, targs_full);
1944 }
1945
1946 MetaType CreateMetaInfo ()
1947 {
1948 //
1949 // Converts nested type arguments into right order
1950 // Foo<string, bool>.Bar<int> => string, bool, int
1951 //
1952 var all = new List<MetaType> ();
1953 TypeSpec type = this;
1954 TypeSpec definition = type;
1955 do {
1956 if (type.GetDefinition().IsGeneric) {
1957 all.InsertRange (0,
1958 type.TypeArguments != TypeSpec.EmptyTypes ?
1959 type.TypeArguments.Select (l => l.GetMetaInfo ()) :
1960 type.MemberDefinition.TypeParameters.Select (l => l.GetMetaInfo ()));
1961 }
1962
1963 definition = definition.GetDefinition ();
1964 type = type.DeclaringType;
1965 } while (type != null);
1966
1967 return definition.GetMetaInfo ().MakeGenericType (all.ToArray ());
1968 }
1969
1970 public override void CheckObsoleteness (IMemberContext mc, Location loc)
1971 {
1972 base.CheckObsoleteness (mc, loc);
1973
1974 foreach (var ta in TypeArguments)
1975 ta.CheckObsoleteness (mc, loc);
1976 }
1977
1978 public override ObsoleteAttribute GetAttributeObsolete ()
1979 {
1980 return open_type.GetAttributeObsolete ();
1981 }
1982
1983 protected override bool IsNotCLSCompliant (out bool attrValue)
1984 {
1985 if (base.IsNotCLSCompliant (out attrValue))
1986 return true;
1987
1988 foreach (var ta in TypeArguments) {
1989 if (ta.MemberDefinition.CLSAttributeValue == false)
1990 return true;
1991 }
1992
1993 return false;
1994 }
1995
1996 public override TypeSpec GetDefinition ()
1997 {
1998 return open_type;
1999 }
2000
2001 public override MetaType GetMetaInfo ()
2002 {
2003 if (info == null)
2004 info = CreateMetaInfo ();
2005
2006 return info;
2007 }
2008
2009 public override string GetSignatureForError ()
2010 {
2011 if (IsNullableType)
2012 return targs[0].GetSignatureForError () + "?";
2013
2014 return base.GetSignatureForError ();
2015 }
2016
2017 protected override string GetTypeNameSignature ()
2018 {
2019 if (targs.Length == 0 || MemberDefinition is AnonymousTypeClass)
2020 return null;
2021
2022 return "<" + TypeManager.CSharpName (targs) + ">";
2023 }
2024
2025 public bool HasDynamicArgument ()
2026 {
2027 for (int i = 0; i < targs.Length; ++i) {
2028 var item = targs[i];
2029
2030 if (item.BuiltinType == BuiltinTypeSpec.Type.Dynamic)
2031 return true;
2032
2033 if (item is InflatedTypeSpec) {
2034 if (((InflatedTypeSpec) item).HasDynamicArgument ())
2035 return true;
2036
2037 continue;
2038 }
2039
2040 if (item.IsArray) {
2041 while (item.IsArray) {
2042 item = ((ArrayContainer) item).Element;
2043 }
2044
2045 if (item.BuiltinType == BuiltinTypeSpec.Type.Dynamic)
2046 return true;
2047 }
2048 }
2049
2050 return false;
2051 }
2052
2053 protected override void InitializeMemberCache (bool onlyTypes)
2054 {
2055 if (cache == null) {
2056 var open_cache = onlyTypes ? open_type.MemberCacheTypes : open_type.MemberCache;
2057
2058 // Surprisingly, calling MemberCache on open type could meantime create cache on this type
2059 // for imported type parameter constraints referencing nested type of this declaration
2060 if (cache == null)
2061 cache = new MemberCache (open_cache);
2062 }
2063
2064 var inflator = CreateLocalInflator (context);
2065
2066 //
2067 // Two stage inflate due to possible nested types recursive
2068 // references
2069 //
2070 // class A<T> {
2071 // B b;
2072 // class B {
2073 // T Value;
2074 // }
2075 // }
2076 //
2077 // When resolving type of `b' members of `B' cannot be
2078 // inflated because are not yet available in membercache
2079 //
2080 if ((state & StateFlags.PendingMemberCacheMembers) == 0) {
2081 open_type.MemberCacheTypes.InflateTypes (cache, inflator);
2082
2083 //
2084 // Inflate any implemented interfaces
2085 //
2086 if (open_type.Interfaces != null) {
2087 ifaces = new List<TypeSpec> (open_type.Interfaces.Count);
2088 foreach (var iface in open_type.Interfaces) {
2089 var iface_inflated = inflator.Inflate (iface);
2090 if (iface_inflated == null)
2091 continue;
2092
2093 base.AddInterface (iface_inflated);
2094 }
2095 }
2096
2097 //
2098 // Handles the tricky case of recursive nested base generic type
2099 //
2100 // class A<T> : Base<A<T>.Nested> {
2101 // class Nested {}
2102 // }
2103 //
2104 // When inflating A<T>. base type is not yet known, secondary
2105 // inflation is required (not common case) once base scope
2106 // is known
2107 //
2108 if (open_type.BaseType == null) {
2109 if (IsClass)
2110 state |= StateFlags.PendingBaseTypeInflate;
2111 } else {
2112 BaseType = inflator.Inflate (open_type.BaseType);
2113 }
2114 } else if ((state & StateFlags.PendingBaseTypeInflate) != 0) {
2115 //
2116 // It can happen when resolving base type without being defined
2117 // which is not allowed to happen and will always lead to an error
2118 //
2119 // class B { class N {} }
2120 // class A<T> : A<B.N> {}
2121 //
2122 if (open_type.BaseType == null)
2123 return;
2124
2125 BaseType = inflator.Inflate (open_type.BaseType);
2126 state &= ~StateFlags.PendingBaseTypeInflate;
2127 }
2128
2129 if (onlyTypes) {
2130 state |= StateFlags.PendingMemberCacheMembers;
2131 return;
2132 }
2133
2134 var tc = open_type.MemberDefinition as TypeDefinition;
2135 if (tc != null && !tc.HasMembersDefined) {
2136 //
2137 // Inflating MemberCache with undefined members
2138 //
2139 return;
2140 }
2141
2142 if ((state & StateFlags.PendingBaseTypeInflate) != 0) {
2143 BaseType = inflator.Inflate (open_type.BaseType);
2144 state &= ~StateFlags.PendingBaseTypeInflate;
2145 }
2146
2147 state &= ~StateFlags.PendingMemberCacheMembers;
2148 open_type.MemberCache.InflateMembers (cache, open_type, inflator);
2149 }
2150
2151 public override TypeSpec Mutate (TypeParameterMutator mutator)
2152 {
2153 var targs = TypeArguments;
2154 if (targs != null)
2155 targs = mutator.Mutate (targs);
2156
2157 var decl = DeclaringType;
2158 if (IsNested && DeclaringType.IsGenericOrParentIsGeneric)
2159 decl = mutator.Mutate (decl);
2160
2161 if (targs == TypeArguments && decl == DeclaringType)
2162 return this;
2163
2164 var mutated = (InflatedTypeSpec) MemberwiseClone ();
2165 #if DEBUG
2166 mutated.ID += 1000000;
2167 #endif
2168
2169 if (decl != DeclaringType) {
2170 // Gets back MethodInfo in case of metaInfo was inflated
2171 //mutated.info = MemberCache.GetMember<TypeSpec> (DeclaringType.GetDefinition (), this).info;
2172
2173 mutated.declaringType = decl;
2174 mutated.state |= StateFlags.PendingMetaInflate;
2175 }
2176
2177 if (targs != null) {
2178 mutated.targs = targs;
2179 mutated.info = null;
2180 }
2181
2182 return mutated;
2183 }
2184 }
2185
2186
2187 //
2188 // Tracks the type arguments when instantiating a generic type. It's used
2189 // by both type arguments and type parameters
2190 //
2191 public class TypeArguments
2192 {
2193 List<FullNamedExpression> args;
2194 TypeSpec[] atypes;
2195
2196 public TypeArguments (params FullNamedExpression[] types)
2197 {
2198 this.args = new List<FullNamedExpression> (types);
2199 }
2200
2201 public void Add (FullNamedExpression type)
2202 {
2203 args.Add (type);
2204 }
2205
2206 /// <summary>
2207 /// We may only be used after Resolve() is called and return the fully
2208 /// resolved types.
2209 /// </summary>
2210 // TODO: Not needed, just return type from resolve
2211 public TypeSpec[] Arguments {
2212 get {
2213 return atypes;
2214 }
2215 set {
2216 atypes = value;
2217 }
2218 }
2219
2220 public int Count {
2221 get {
2222 return args.Count;
2223 }
2224 }
2225
2226 public virtual bool IsEmpty {
2227 get {
2228 return false;
2229 }
2230 }
2231
2232 public List<FullNamedExpression> TypeExpressions {
2233 get {
2234 return this.args;
2235 }
2236 }
2237
2238 public string GetSignatureForError()
2239 {
2240 StringBuilder sb = new StringBuilder ();
2241 for (int i = 0; i < Count; ++i) {
2242 var expr = args[i];
2243 if (expr != null)
2244 sb.Append (expr.GetSignatureForError ());
2245
2246 if (i + 1 < Count)
2247 sb.Append (',');
2248 }
2249
2250 return sb.ToString ();
2251 }
2252
2253 /// <summary>
2254 /// Resolve the type arguments.
2255 /// </summary>
2256 public virtual bool Resolve (IMemberContext ec, bool allowUnbound)
2257 {
2258 if (atypes != null)
2259 return true;
2260
2261 int count = args.Count;
2262 bool ok = true;
2263
2264 atypes = new TypeSpec [count];
2265
2266 var errors = ec.Module.Compiler.Report.Errors;
2267
2268 for (int i = 0; i < count; i++){
2269 var te = args[i].ResolveAsType (ec);
2270 if (te == null) {
2271 ok = false;
2272 continue;
2273 }
2274
2275 atypes[i] = te;
2276
2277 if (te.IsStatic) {
2278 ec.Module.Compiler.Report.Error (718, args[i].Location, "`{0}': static classes cannot be used as generic arguments",
2279 te.GetSignatureForError ());
2280 ok = false;
2281 }
2282
2283 if (te.IsPointer || te.IsSpecialRuntimeType) {
2284 ec.Module.Compiler.Report.Error (306, args[i].Location,
2285 "The type `{0}' may not be used as a type argument",
2286 te.GetSignatureForError ());
2287 ok = false;
2288 }
2289 }
2290
2291 if (!ok || errors != ec.Module.Compiler.Report.Errors)
2292 atypes = null;
2293
2294 return ok;
2295 }
2296
2297 public TypeArguments Clone ()
2298 {
2299 TypeArguments copy = new TypeArguments ();
2300 foreach (var ta in args)
2301 copy.args.Add (ta);
2302
2303 return copy;
2304 }
2305 }
2306
2307 public class UnboundTypeArguments : TypeArguments
2308 {
2309 Location loc;
2310
2311 public UnboundTypeArguments (int arity, Location loc)
2312 : base (new FullNamedExpression[arity])
2313 {
2314 this.loc = loc;
2315 }
2316
2317 public override bool IsEmpty {
2318 get {
2319 return true;
2320 }
2321 }
2322
2323 public override bool Resolve (IMemberContext mc, bool allowUnbound)
2324 {
2325 if (!allowUnbound) {
2326 mc.Module.Compiler.Report.Error (7003, loc, "Unbound generic name is not valid in this context");
2327 }
2328
2329 // Nothing to be resolved
2330 return true;
2331 }
2332 }
2333
2334 public class TypeParameters
2335 {
2336 List<TypeParameter> names;
2337 TypeParameterSpec[] types;
2338
2339 public TypeParameters ()
2340 {
2341 names = new List<TypeParameter> ();
2342 }
2343
2344 public TypeParameters (int count)
2345 {
2346 names = new List<TypeParameter> (count);
2347 }
2348
2349 #region Properties
2350
2351 public int Count {
2352 get {
2353 return names.Count;
2354 }
2355 }
2356
2357 public TypeParameterSpec[] Types {
2358 get {
2359 return types;
2360 }
2361 }
2362
2363 #endregion
2364
2365 public void Add (TypeParameter tparam)
2366 {
2367 names.Add (tparam);
2368 }
2369
2370 public void Add (TypeParameters tparams)
2371 {
2372 names.AddRange (tparams.names);
2373 }
2374
2375 public void Create (TypeSpec declaringType, int parentOffset, TypeContainer parent)
2376 {
2377 types = new TypeParameterSpec[Count];
2378 for (int i = 0; i < types.Length; ++i) {
2379 var tp = names[i];
2380
2381 tp.Create (declaringType, parent);
2382 types[i] = tp.Type;
2383 types[i].DeclaredPosition = i + parentOffset;
2384
2385 if (tp.Variance != Variance.None && !(declaringType != null && (declaringType.Kind == MemberKind.Interface || declaringType.Kind == MemberKind.Delegate))) {
2386 parent.Compiler.Report.Error (1960, tp.Location, "Variant type parameters can only be used with interfaces and delegates");
2387 }
2388 }
2389 }
2390
2391 public void Define (GenericTypeParameterBuilder[] builders)
2392 {
2393 for (int i = 0; i < types.Length; ++i) {
2394 var tp = names[i];
2395 tp.Define (builders [types [i].DeclaredPosition]);
2396 }
2397 }
2398
2399 public TypeParameter this[int index] {
2400 get {
2401 return names [index];
2402 }
2403 set {
2404 names[index] = value;
2405 }
2406 }
2407
2408 public TypeParameter Find (string name)
2409 {
2410 foreach (var tp in names) {
2411 if (tp.Name == name)
2412 return tp;
2413 }
2414
2415 return null;
2416 }
2417
2418 public string[] GetAllNames ()
2419 {
2420 return names.Select (l => l.Name).ToArray ();
2421 }
2422
2423 public string GetSignatureForError ()
2424 {
2425 StringBuilder sb = new StringBuilder ();
2426 for (int i = 0; i < Count; ++i) {
2427 if (i > 0)
2428 sb.Append (',');
2429
2430 var name = names[i];
2431 if (name != null)
2432 sb.Append (name.GetSignatureForError ());
2433 }
2434
2435 return sb.ToString ();
2436 }
2437
2438
2439 public void CheckPartialConstraints (Method part)
2440 {
2441 var partTypeParameters = part.CurrentTypeParameters;
2442
2443 for (int i = 0; i < Count; i++) {
2444 var tp_a = names[i];
2445 var tp_b = partTypeParameters [i];
2446 if (tp_a.Constraints == null) {
2447 if (tp_b.Constraints == null)
2448 continue;
2449 } else if (tp_b.Constraints != null && tp_a.Type.HasSameConstraintsDefinition (tp_b.Type)) {
2450 continue;
2451 }
2452
2453 part.Compiler.Report.SymbolRelatedToPreviousError (this[i].CurrentMemberDefinition.Location, "");
2454 part.Compiler.Report.Error (761, part.Location,
2455 "Partial method declarations of `{0}' have inconsistent constraints for type parameter `{1}'",
2456 part.GetSignatureForError (), partTypeParameters[i].GetSignatureForError ());
2457 }
2458 }
2459
2460 public void UpdateConstraints (TypeDefinition part)
2461 {
2462 var partTypeParameters = part.MemberName.TypeParameters;
2463
2464 for (int i = 0; i < Count; i++) {
2465 var tp = names [i];
2466 if (tp.AddPartialConstraints (part, partTypeParameters [i]))
2467 continue;
2468
2469 part.Compiler.Report.SymbolRelatedToPreviousError (this[i].CurrentMemberDefinition);
2470 part.Compiler.Report.Error (265, part.Location,
2471 "Partial declarations of `{0}' have inconsistent constraints for type parameter `{1}'",
2472 part.GetSignatureForError (), tp.GetSignatureForError ());
2473 }
2474 }
2475
2476 public void VerifyClsCompliance ()
2477 {
2478 foreach (var tp in names) {
2479 tp.VerifyClsCompliance ();
2480 }
2481 }
2482 }
2483
2484 //
2485 // A type expression of generic type with type arguments
2486 //
2487 class GenericTypeExpr : TypeExpr
2488 {
2489 TypeArguments args;
2490 TypeSpec open_type;
2491
2492 /// <summary>
2493 /// Instantiate the generic type `t' with the type arguments `args'.
2494 /// Use this constructor if you already know the fully resolved
2495 /// generic type.
2496 /// </summary>
2497 public GenericTypeExpr (TypeSpec open_type, TypeArguments args, Location l)
2498 {
2499 this.open_type = open_type;
2500 loc = l;
2501 this.args = args;
2502 }
2503
2504 public override string GetSignatureForError ()
2505 {
2506 return type.GetSignatureForError ();
2507 }
2508
2509 public override TypeSpec ResolveAsType (IMemberContext mc, bool allowUnboundTypeArguments = false)
2510 {
2511 if (eclass != ExprClass.Unresolved)
2512 return type;
2513
2514 if (!args.Resolve (mc, allowUnboundTypeArguments))
2515 return null;
2516
2517 TypeSpec[] atypes = args.Arguments;
2518 if (atypes == null)
2519 return null;
2520
2521 //
2522 // Now bind the parameters
2523 //
2524 var inflated = open_type.MakeGenericType (mc, atypes);
2525 type = inflated;
2526 eclass = ExprClass.Type;
2527
2528 //
2529 // The constraints can be checked only when full type hierarchy is known
2530 //
2531 if (!inflated.HasConstraintsChecked && mc.Module.HasTypesFullyDefined) {
2532 var constraints = inflated.Constraints;
2533 if (constraints != null) {
2534 var cc = new ConstraintChecker (mc);
2535 if (cc.CheckAll (open_type, atypes, constraints, loc)) {
2536 inflated.HasConstraintsChecked = true;
2537 }
2538 }
2539 }
2540
2541 return type;
2542 }
2543
2544 public override bool Equals (object obj)
2545 {
2546 GenericTypeExpr cobj = obj as GenericTypeExpr;
2547 if (cobj == null)
2548 return false;
2549
2550 if ((type == null) || (cobj.type == null))
2551 return false;
2552
2553 return type == cobj.type;
2554 }
2555
2556 public override int GetHashCode ()
2557 {
2558 return base.GetHashCode ();
2559 }
2560 }
2561
2562 //
2563 // Generic type with unbound type arguments, used for typeof (G<,,>)
2564 //
2565 class GenericOpenTypeExpr : TypeExpression
2566 {
2567 public GenericOpenTypeExpr (TypeSpec type, /*UnboundTypeArguments args,*/ Location loc)
2568 : base (type.GetDefinition (), loc)
2569 {
2570 }
2571 }
2572
2573 struct ConstraintChecker
2574 {
2575 IMemberContext mc;
2576 bool recursive_checks;
2577
2578 public ConstraintChecker (IMemberContext ctx)
2579 {
2580 this.mc = ctx;
2581 recursive_checks = false;
2582 }
2583
2584 //
2585 // Checks the constraints of open generic type against type
2586 // arguments. This version is used for types which could not be
2587 // checked immediatelly during construction because the type
2588 // hierarchy was not yet fully setup (before Emit phase)
2589 //
2590 public static bool Check (IMemberContext mc, TypeSpec type, Location loc)
2591 {
2592 //
2593 // Check declaring type first if there is any
2594 //
2595 if (type.DeclaringType != null && !Check (mc, type.DeclaringType, loc))
2596 return false;
2597
2598 while (type is ElementTypeSpec)
2599 type = ((ElementTypeSpec) type).Element;
2600
2601 if (type.Arity == 0)
2602 return true;
2603
2604 var gtype = type as InflatedTypeSpec;
2605 if (gtype == null)
2606 return true;
2607
2608 var constraints = gtype.Constraints;
2609 if (constraints == null)
2610 return true;
2611
2612 if (gtype.HasConstraintsChecked)
2613 return true;
2614
2615 var cc = new ConstraintChecker (mc);
2616 cc.recursive_checks = true;
2617
2618 if (cc.CheckAll (gtype.GetDefinition (), type.TypeArguments, constraints, loc)) {
2619 gtype.HasConstraintsChecked = true;
2620 return true;
2621 }
2622
2623 return false;
2624 }
2625
2626 //
2627 // Checks all type arguments againts type parameters constraints
2628 // NOTE: It can run in probing mode when `this.mc' is null
2629 //
2630 public bool CheckAll (MemberSpec context, TypeSpec[] targs, TypeParameterSpec[] tparams, Location loc)
2631 {
2632 if (targs == null)
2633 return true;
2634
2635 for (int i = 0; i < tparams.Length; i++) {
2636 var targ = targs[i];
2637 if (!CheckConstraint (context, targ, tparams [i], loc))
2638 return false;
2639
2640 if (!recursive_checks)
2641 continue;
2642
2643 if (!Check (mc, targ, loc))
2644 return false;
2645 }
2646
2647 return true;
2648 }
2649
2650 bool CheckConstraint (MemberSpec context, TypeSpec atype, TypeParameterSpec tparam, Location loc)
2651 {
2652 //
2653 // First, check the `class' and `struct' constraints.
2654 //
2655 if (tparam.HasSpecialClass && !TypeSpec.IsReferenceType (atype)) {
2656 if (mc != null) {
2657 mc.Module.Compiler.Report.Error (452, loc,
2658 "The type `{0}' must be a reference type in order to use it as type parameter `{1}' in the generic type or method `{2}'",
2659 atype.GetSignatureForError (), tparam.GetSignatureForError (), context.GetSignatureForError ());
2660 }
2661
2662 return false;
2663 }
2664
2665 if (tparam.HasSpecialStruct && (!TypeSpec.IsValueType (atype) || atype.IsNullableType)) {
2666 if (mc != null) {
2667 mc.Module.Compiler.Report.Error (453, loc,
2668 "The type `{0}' must be a non-nullable value type in order to use it as type parameter `{1}' in the generic type or method `{2}'",
2669 atype.GetSignatureForError (), tparam.GetSignatureForError (), context.GetSignatureForError ());
2670 }
2671
2672 return false;
2673 }
2674
2675 bool ok = true;
2676
2677 //
2678 // Check the class constraint
2679 //
2680 if (tparam.HasTypeConstraint) {
2681 if (!CheckConversion (mc, context, atype, tparam, tparam.BaseType, loc)) {
2682 if (mc == null)
2683 return false;
2684
2685 ok = false;
2686 }
2687 }
2688
2689 //
2690 // Check the interfaces constraints
2691 //
2692 if (tparam.InterfacesDefined != null) {
2693 foreach (TypeSpec iface in tparam.InterfacesDefined) {
2694 if (!CheckConversion (mc, context, atype, tparam, iface, loc)) {
2695 if (mc == null)
2696 return false;
2697
2698 ok = false;
2699 break;
2700 }
2701 }
2702 }
2703
2704 //
2705 // Check the type parameter constraint
2706 //
2707 if (tparam.TypeArguments != null) {
2708 foreach (var ta in tparam.TypeArguments) {
2709 if (!CheckConversion (mc, context, atype, tparam, ta, loc)) {
2710 if (mc == null)
2711 return false;
2712
2713 ok = false;
2714 break;
2715 }
2716 }
2717 }
2718
2719 //
2720 // Finally, check the constructor constraint.
2721 //
2722 if (!tparam.HasSpecialConstructor)
2723 return ok;
2724
2725 if (!HasDefaultConstructor (atype)) {
2726 if (mc != null) {
2727 mc.Module.Compiler.Report.SymbolRelatedToPreviousError (atype);
2728 mc.Module.Compiler.Report.Error (310, loc,
2729 "The type `{0}' must have a public parameterless constructor in order to use it as parameter `{1}' in the generic type or method `{2}'",
2730 atype.GetSignatureForError (), tparam.GetSignatureForError (), context.GetSignatureForError ());
2731 }
2732 return false;
2733 }
2734
2735 return ok;
2736 }
2737
2738 static bool HasDynamicTypeArgument (TypeSpec[] targs)
2739 {
2740 for (int i = 0; i < targs.Length; ++i) {
2741 var targ = targs [i];
2742 if (targ.BuiltinType == BuiltinTypeSpec.Type.Dynamic)
2743 return true;
2744
2745 if (HasDynamicTypeArgument (targ.TypeArguments))
2746 return true;
2747 }
2748
2749 return false;
2750 }
2751
2752 bool CheckConversion (IMemberContext mc, MemberSpec context, TypeSpec atype, TypeParameterSpec tparam, TypeSpec ttype, Location loc)
2753 {
2754 if (atype == ttype)
2755 return true;
2756
2757 if (atype.IsGenericParameter) {
2758 var tps = (TypeParameterSpec) atype;
2759 if (tps.HasDependencyOn (ttype))
2760 return true;
2761
2762 if (Convert.ImplicitTypeParameterConversion (null, tps, ttype) != null)
2763 return true;
2764
2765 } else if (TypeSpec.IsValueType (atype)) {
2766 if (atype.IsNullableType) {
2767 //
2768 // LAMESPEC: Only identity or base type ValueType or Object satisfy nullable type
2769 //
2770 if (TypeSpec.IsBaseClass (atype, ttype, false))
2771 return true;
2772 } else {
2773 if (Convert.ImplicitBoxingConversion (null, atype, ttype) != null)
2774 return true;
2775 }
2776 } else {
2777 if (Convert.ImplicitReferenceConversionExists (atype, ttype) || Convert.ImplicitBoxingConversion (null, atype, ttype) != null)
2778 return true;
2779 }
2780
2781 if (mc != null) {
2782 mc.Module.Compiler.Report.SymbolRelatedToPreviousError (tparam);
2783 if (atype.IsGenericParameter) {
2784 mc.Module.Compiler.Report.Error (314, loc,
2785 "The type `{0}' cannot be used as type parameter `{1}' in the generic type or method `{2}'. There is no boxing or type parameter conversion from `{0}' to `{3}'",
2786 atype.GetSignatureForError (), tparam.GetSignatureForError (), context.GetSignatureForError (), ttype.GetSignatureForError ());
2787 } else if (TypeSpec.IsValueType (atype)) {
2788 if (atype.IsNullableType) {
2789 if (ttype.IsInterface) {
2790 mc.Module.Compiler.Report.Error (313, loc,
2791 "The type `{0}' cannot be used as type parameter `{1}' in the generic type or method `{2}'. The nullable type `{0}' never satisfies interface constraint `{3}'",
2792 atype.GetSignatureForError (), tparam.GetSignatureForError (), context.GetSignatureForError (), ttype.GetSignatureForError ());
2793 } else {
2794 mc.Module.Compiler.Report.Error (312, loc,
2795 "The type `{0}' cannot be used as type parameter `{1}' in the generic type or method `{2}'. The nullable type `{0}' does not satisfy constraint `{3}'",
2796 atype.GetSignatureForError (), tparam.GetSignatureForError (), context.GetSignatureForError (), ttype.GetSignatureForError ());
2797 }
2798 } else {
2799 mc.Module.Compiler.Report.Error (315, loc,
2800 "The type `{0}' cannot be used as type parameter `{1}' in the generic type or method `{2}'. There is no boxing conversion from `{0}' to `{3}'",
2801 atype.GetSignatureForError (), tparam.GetSignatureForError (), context.GetSignatureForError (), ttype.GetSignatureForError ());
2802 }
2803 } else {
2804 mc.Module.Compiler.Report.Error (311, loc,
2805 "The type `{0}' cannot be used as type parameter `{1}' in the generic type or method `{2}'. There is no implicit reference conversion from `{0}' to `{3}'",
2806 atype.GetSignatureForError (), tparam.GetSignatureForError (), context.GetSignatureForError (), ttype.GetSignatureForError ());
2807 }
2808 }
2809
2810 return false;
2811 }
2812
2813 static bool HasDefaultConstructor (TypeSpec atype)
2814 {
2815 var tp = atype as TypeParameterSpec;
2816 if (tp != null) {
2817 return tp.HasSpecialConstructor || tp.HasSpecialStruct;
2818 }
2819
2820 if (atype.IsStruct || atype.IsEnum)
2821 return true;
2822
2823 if (atype.IsAbstract)
2824 return false;
2825
2826 var tdef = atype.GetDefinition ();
2827
2828 var found = MemberCache.FindMember (tdef,
2829 MemberFilter.Constructor (ParametersCompiled.EmptyReadOnlyParameters),
2830 BindingRestriction.DeclaredOnly | BindingRestriction.InstanceOnly);
2831
2832 return found != null && (found.Modifiers & Modifiers.PUBLIC) != 0;
2833 }
2834 }
2835
2836 //
2837 // Implements C# type inference
2838 //
2839 class TypeInference
2840 {
2841 //
2842 // Tracks successful rate of type inference
2843 //
2844 int score;
2845 readonly Arguments arguments;
2846 readonly int arg_count;
2847
2848 public TypeInference (Arguments arguments)
2849 {
2850 this.arguments = arguments;
2851 if (arguments != null)
2852 arg_count = arguments.Count;
2853 }
2854
2855 public int InferenceScore {
2856 get {
2857 return score;
2858 }
2859 }
2860
2861 public TypeSpec[] InferMethodArguments (ResolveContext ec, MethodSpec method)
2862 {
2863 var method_generic_args = method.GenericDefinition.TypeParameters;
2864 TypeInferenceContext context = new TypeInferenceContext (method_generic_args);
2865 if (!context.UnfixedVariableExists)
2866 return TypeSpec.EmptyTypes;
2867
2868 AParametersCollection pd = method.Parameters;
2869 if (!InferInPhases (ec, context, pd))
2870 return null;
2871
2872 return context.InferredTypeArguments;
2873 }
2874
2875 //
2876 // Implements method type arguments inference
2877 //
2878 bool InferInPhases (ResolveContext ec, TypeInferenceContext tic, AParametersCollection methodParameters)
2879 {
2880 int params_arguments_start;
2881 if (methodParameters.HasParams) {
2882 params_arguments_start = methodParameters.Count - 1;
2883 } else {
2884 params_arguments_start = arg_count;
2885 }
2886
2887 TypeSpec [] ptypes = methodParameters.Types;
2888
2889 //
2890 // The first inference phase
2891 //
2892 TypeSpec method_parameter = null;
2893 for (int i = 0; i < arg_count; i++) {
2894 Argument a = arguments [i];
2895 if (a == null)
2896 continue;
2897
2898 if (i < params_arguments_start) {
2899 method_parameter = methodParameters.Types [i];
2900 } else if (i == params_arguments_start) {
2901 if (arg_count == params_arguments_start + 1 && TypeManager.HasElementType (a.Type))
2902 method_parameter = methodParameters.Types [params_arguments_start];
2903 else
2904 method_parameter = TypeManager.GetElementType (methodParameters.Types [params_arguments_start]);
2905
2906 ptypes = (TypeSpec[]) ptypes.Clone ();
2907 ptypes [i] = method_parameter;
2908 }
2909
2910 //
2911 // When a lambda expression, an anonymous method
2912 // is used an explicit argument type inference takes a place
2913 //
2914 AnonymousMethodExpression am = a.Expr as AnonymousMethodExpression;
2915 if (am != null) {
2916 if (am.ExplicitTypeInference (tic, method_parameter))
2917 ++score;
2918 continue;
2919 }
2920
2921 if (a.IsByRef) {
2922 score += tic.ExactInference (a.Type, method_parameter);
2923 continue;
2924 }
2925
2926 if (a.Expr.Type == InternalType.NullLiteral)
2927 continue;
2928
2929 if (TypeSpec.IsValueType (method_parameter)) {
2930 score += tic.LowerBoundInference (a.Type, method_parameter);
2931 continue;
2932 }
2933
2934 //
2935 // Otherwise an output type inference is made
2936 //
2937 score += tic.OutputTypeInference (ec, a.Expr, method_parameter);
2938 }
2939
2940 //
2941 // Part of the second phase but because it happens only once
2942 // we don't need to call it in cycle
2943 //
2944 bool fixed_any = false;
2945 if (!tic.FixIndependentTypeArguments (ec, ptypes, ref fixed_any))
2946 return false;
2947
2948 return DoSecondPhase (ec, tic, ptypes, !fixed_any);
2949 }
2950
2951 bool DoSecondPhase (ResolveContext ec, TypeInferenceContext tic, TypeSpec[] methodParameters, bool fixDependent)
2952 {
2953 bool fixed_any = false;
2954 if (fixDependent && !tic.FixDependentTypes (ec, ref fixed_any))
2955 return false;
2956
2957 // If no further unfixed type variables exist, type inference succeeds
2958 if (!tic.UnfixedVariableExists)
2959 return true;
2960
2961 if (!fixed_any && fixDependent)
2962 return false;
2963
2964 // For all arguments where the corresponding argument output types
2965 // contain unfixed type variables but the input types do not,
2966 // an output type inference is made
2967 for (int i = 0; i < arg_count; i++) {
2968
2969 // Align params arguments
2970 TypeSpec t_i = methodParameters [i >= methodParameters.Length ? methodParameters.Length - 1: i];
2971
2972 if (!t_i.IsDelegate) {
2973 if (!t_i.IsExpressionTreeType)
2974 continue;
2975
2976 t_i = TypeManager.GetTypeArguments (t_i) [0];
2977 }
2978
2979 var mi = Delegate.GetInvokeMethod (t_i);
2980 TypeSpec rtype = mi.ReturnType;
2981
2982 if (tic.IsReturnTypeNonDependent (mi, rtype)) {
2983 // It can be null for default arguments
2984 if (arguments[i] == null)
2985 continue;
2986
2987 score += tic.OutputTypeInference (ec, arguments[i].Expr, t_i);
2988 }
2989 }
2990
2991
2992 return DoSecondPhase (ec, tic, methodParameters, true);
2993 }
2994 }
2995
2996 public class TypeInferenceContext
2997 {
2998 protected enum BoundKind
2999 {
3000 Exact = 0,
3001 Lower = 1,
3002 Upper = 2
3003 }
3004
3005 struct BoundInfo : IEquatable<BoundInfo>
3006 {
3007 public readonly TypeSpec Type;
3008 public readonly BoundKind Kind;
3009
3010 public BoundInfo (TypeSpec type, BoundKind kind)
3011 {
3012 this.Type = type;
3013 this.Kind = kind;
3014 }
3015
3016 public override int GetHashCode ()
3017 {
3018 return Type.GetHashCode ();
3019 }
3020
3021 public Expression GetTypeExpression ()
3022 {
3023 return new TypeExpression (Type, Location.Null);
3024 }
3025
3026 #region IEquatable<BoundInfo> Members
3027
3028 public bool Equals (BoundInfo other)
3029 {
3030 return Type == other.Type && Kind == other.Kind;
3031 }
3032
3033 #endregion
3034 }
3035
3036 readonly TypeSpec[] tp_args;
3037 readonly TypeSpec[] fixed_types;
3038 readonly List<BoundInfo>[] bounds;
3039
3040 // TODO MemberCache: Could it be TypeParameterSpec[] ??
3041 public TypeInferenceContext (TypeSpec[] typeArguments)
3042 {
3043 if (typeArguments.Length == 0)
3044 throw new ArgumentException ("Empty generic arguments");
3045
3046 fixed_types = new TypeSpec [typeArguments.Length];
3047 for (int i = 0; i < typeArguments.Length; ++i) {
3048 if (typeArguments [i].IsGenericParameter) {
3049 if (bounds == null) {
3050 bounds = new List<BoundInfo> [typeArguments.Length];
3051 tp_args = new TypeSpec [typeArguments.Length];
3052 }
3053 tp_args [i] = typeArguments [i];
3054 } else {
3055 fixed_types [i] = typeArguments [i];
3056 }
3057 }
3058 }
3059
3060 //
3061 // Used together with AddCommonTypeBound fo implement
3062 // 7.4.2.13 Finding the best common type of a set of expressions
3063 //
3064 public TypeInferenceContext ()
3065 {
3066 fixed_types = new TypeSpec [1];
3067 tp_args = new TypeSpec [1];
3068 tp_args[0] = InternalType.Arglist; // it can be any internal type
3069 bounds = new List<BoundInfo> [1];
3070 }
3071
3072 public TypeSpec[] InferredTypeArguments {
3073 get {
3074 return fixed_types;
3075 }
3076 }
3077
3078 public void AddCommonTypeBound (TypeSpec type)
3079 {
3080 AddToBounds (new BoundInfo (type, BoundKind.Lower), 0, false);
3081 }
3082
3083 public void AddCommonTypeBoundAsync (TypeSpec type)
3084 {
3085 AddToBounds (new BoundInfo (type, BoundKind.Lower), 0, true);
3086 }
3087
3088 void AddToBounds (BoundInfo bound, int index, bool voidAllowed)
3089 {
3090 //
3091 // Some types cannot be used as type arguments
3092 //
3093 if ((bound.Type.Kind == MemberKind.Void && !voidAllowed) || bound.Type.IsPointer || bound.Type.IsSpecialRuntimeType ||
3094 bound.Type == InternalType.MethodGroup || bound.Type == InternalType.AnonymousMethod || bound.Type == InternalType.VarOutType)
3095 return;
3096
3097 var a = bounds [index];
3098 if (a == null) {
3099 a = new List<BoundInfo> (2);
3100 a.Add (bound);
3101 bounds [index] = a;
3102 return;
3103 }
3104
3105 if (a.Contains (bound))
3106 return;
3107
3108 a.Add (bound);
3109 }
3110
3111 bool AllTypesAreFixed (TypeSpec[] types)
3112 {
3113 foreach (TypeSpec t in types) {
3114 if (t.IsGenericParameter) {
3115 if (!IsFixed (t))
3116 return false;
3117 continue;
3118 }
3119
3120 if (t.IsGeneric && !AllTypesAreFixed (t.TypeArguments))
3121 return false;
3122 }
3123
3124 return true;
3125 }
3126
3127 //
3128 // 26.3.3.8 Exact Inference
3129 //
3130 public int ExactInference (TypeSpec u, TypeSpec v)
3131 {
3132 // If V is an array type
3133 if (v.IsArray) {
3134 if (!u.IsArray)
3135 return 0;
3136
3137 var ac_u = (ArrayContainer) u;
3138 var ac_v = (ArrayContainer) v;
3139 if (ac_u.Rank != ac_v.Rank)
3140 return 0;
3141
3142 return ExactInference (ac_u.Element, ac_v.Element);
3143 }
3144
3145 //
3146 // If V is constructed type and U is constructed type or dynamic
3147 //
3148 if (TypeManager.IsGenericType (v)) {
3149 if (u.BuiltinType == BuiltinTypeSpec.Type.Dynamic) {
3150
3151 var ga_v = v.TypeArguments;
3152
3153 int score = 0;
3154 for (int i = 0; i < ga_v.Length; ++i)
3155 score += ExactInference (u, ga_v [i]);
3156
3157 return System.Math.Min (1, score);
3158
3159 } else {
3160 if (!TypeManager.IsGenericType (u) || v.MemberDefinition != u.MemberDefinition)
3161 return 0;
3162
3163 var ga_u = u.TypeArguments;
3164 var ga_v = v.TypeArguments;
3165
3166 if (u.TypeArguments.Length != v.TypeArguments.Length)
3167 return 0;
3168
3169 int score = 0;
3170 for (int i = 0; i < ga_v.Length; ++i)
3171 score += ExactInference (ga_u [i], ga_v [i]);
3172
3173 return System.Math.Min (1, score);
3174 }
3175 }
3176
3177 // If V is one of the unfixed type arguments
3178 int pos = IsUnfixed (v);
3179 if (pos == -1)
3180 return 0;
3181
3182 AddToBounds (new BoundInfo (u, BoundKind.Exact), pos, false);
3183 return 1;
3184 }
3185
3186 public bool FixAllTypes (ResolveContext ec)
3187 {
3188 for (int i = 0; i < tp_args.Length; ++i) {
3189 if (!FixType (ec, i))
3190 return false;
3191 }
3192 return true;
3193 }
3194
3195 //
3196 // All unfixed type variables Xi are fixed for which all of the following hold:
3197 // a, There is at least one type variable Xj that depends on Xi
3198 // b, Xi has a non-empty set of bounds
3199 //
3200 public bool FixDependentTypes (ResolveContext ec, ref bool fixed_any)
3201 {
3202 for (int i = 0; i < tp_args.Length; ++i) {
3203 if (fixed_types[i] != null)
3204 continue;
3205
3206 if (bounds[i] == null)
3207 continue;
3208
3209 if (!FixType (ec, i))
3210 return false;
3211
3212 fixed_any = true;
3213 }
3214
3215 return true;
3216 }
3217
3218 //
3219 // All unfixed type variables Xi which depend on no Xj are fixed
3220 //
3221 public bool FixIndependentTypeArguments (ResolveContext ec, TypeSpec[] methodParameters, ref bool fixed_any)
3222 {
3223 var types_to_fix = new List<TypeSpec> (tp_args);
3224 for (int i = 0; i < methodParameters.Length; ++i) {
3225 TypeSpec t = methodParameters[i];
3226
3227 if (!t.IsDelegate) {
3228 if (!t.IsExpressionTreeType)
3229 continue;
3230
3231 t = TypeManager.GetTypeArguments (t) [0];
3232 }
3233
3234 if (t.IsGenericParameter)
3235 continue;
3236
3237 var invoke = Delegate.GetInvokeMethod (t);
3238 TypeSpec rtype = invoke.ReturnType;
3239 while (rtype.IsArray)
3240 rtype = ((ArrayContainer) rtype).Element;
3241
3242 if (!rtype.IsGenericParameter && !TypeManager.IsGenericType (rtype))
3243 continue;
3244
3245 // Remove dependent types, they cannot be fixed yet
3246 RemoveDependentTypes (types_to_fix, rtype);
3247 }
3248
3249 foreach (TypeSpec t in types_to_fix) {
3250 if (t == null)
3251 continue;
3252
3253 int idx = IsUnfixed (t);
3254 if (idx >= 0 && !FixType (ec, idx)) {
3255 return false;
3256 }
3257 }
3258
3259 fixed_any = types_to_fix.Count > 0;
3260 return true;
3261 }
3262
3263 //
3264 // 26.3.3.10 Fixing
3265 //
3266 public bool FixType (ResolveContext ec, int i)
3267 {
3268 // It's already fixed
3269 if (fixed_types[i] != null)
3270 throw new InternalErrorException ("Type argument has been already fixed");
3271
3272 var candidates = bounds [i];
3273 if (candidates == null)
3274 return false;
3275
3276 if (candidates.Count == 1) {
3277 TypeSpec t = candidates[0].Type;
3278 if (t == InternalType.NullLiteral)
3279 return false;
3280
3281 fixed_types [i] = t;
3282 return true;
3283 }
3284
3285 //
3286 // The set of candidate types Uj starts out as the set of
3287 // all types in the set of bounds for Xi
3288 //
3289 var applicable = new bool [candidates.Count];
3290 for (int ci = 0; ci < applicable.Length; ++ci)
3291 applicable [ci] = true;
3292
3293 for (int ci = 0; ci < applicable.Length; ++ci) {
3294 var bound = candidates [ci];
3295 int cii = 0;
3296
3297 switch (bound.Kind) {
3298 case BoundKind.Exact:
3299 for (; cii != applicable.Length; ++cii) {
3300 if (ci == cii)
3301 continue;
3302
3303 if (!applicable[cii])
3304 continue;
3305
3306 //
3307 // For each exact bound U of Xi all types Uj which are not identical
3308 // to U are removed from the candidate set
3309 //
3310 if (candidates [cii].Type != bound.Type)
3311 applicable[cii] = false;
3312 }
3313
3314 break;
3315 case BoundKind.Lower:
3316 for (; cii != applicable.Length; ++cii) {
3317 if (ci == cii)
3318 continue;
3319
3320 if (!applicable[cii])
3321 continue;
3322
3323 //
3324 // For each lower bound U of Xi all types Uj to which there is not an implicit conversion
3325 // from U are removed from the candidate set
3326 //
3327 if (!Convert.ImplicitConversionExists (ec, bound.GetTypeExpression (), candidates [cii].Type)) {
3328 applicable[cii] = false;
3329 }
3330 }
3331
3332 break;
3333
3334 case BoundKind.Upper:
3335 for (; cii != applicable.Length; ++cii) {
3336 if (ci == cii)
3337 continue;
3338
3339 if (!applicable[cii])
3340 continue;
3341
3342 //
3343 // For each upper bound U of Xi all types Uj from which there is not an implicit conversion
3344 // to U are removed from the candidate set
3345 //
3346 if (!Convert.ImplicitConversionExists (ec, candidates[cii].GetTypeExpression (), bound.Type))
3347 applicable[cii] = false;
3348 }
3349
3350 break;
3351 }
3352 }
3353
3354 TypeSpec best_candidate = null;
3355 for (int ci = 0; ci < applicable.Length; ++ci) {
3356 if (!applicable[ci])
3357 continue;
3358
3359 var bound = candidates [ci];
3360 if (bound.Type == best_candidate)
3361 continue;
3362
3363 int cii = 0;
3364 for (; cii < applicable.Length; ++cii) {
3365 if (ci == cii)
3366 continue;
3367
3368 if (!applicable[cii])
3369 continue;
3370
3371 if (!Convert.ImplicitConversionExists (ec, candidates[cii].GetTypeExpression (), bound.Type))
3372 break;
3373 }
3374
3375 if (cii != applicable.Length)
3376 continue;
3377
3378 //
3379 // We already have the best candidate, break if it's different (non-unique)
3380 //
3381 // Dynamic is never ambiguous as we prefer dynamic over other best candidate types
3382 //
3383 if (best_candidate != null) {
3384
3385 if (best_candidate.BuiltinType == BuiltinTypeSpec.Type.Dynamic)
3386 continue;
3387
3388 if (bound.Type.BuiltinType != BuiltinTypeSpec.Type.Dynamic && best_candidate != bound.Type)
3389 return false;
3390 }
3391
3392 best_candidate = bound.Type;
3393 }
3394
3395 if (best_candidate == null)
3396 return false;
3397
3398 fixed_types[i] = best_candidate;
3399 return true;
3400 }
3401
3402 public bool HasBounds (int pos)
3403 {
3404 return bounds[pos] != null;
3405 }
3406
3407 //
3408 // Uses inferred or partially infered types to inflate delegate type argument. Returns
3409 // null when type parameter has not been fixed
3410 //
3411 public TypeSpec InflateGenericArgument (IModuleContext context, TypeSpec parameter)
3412 {
3413 var tp = parameter as TypeParameterSpec;
3414 if (tp != null) {
3415 //
3416 // Type inference works on generic arguments (MVAR) only
3417 //
3418 if (!tp.IsMethodOwned)
3419 return parameter;
3420
3421 //
3422 // Ensure the type parameter belongs to same container
3423 //
3424 if (tp.DeclaredPosition < tp_args.Length && tp_args[tp.DeclaredPosition] == parameter)
3425 return fixed_types[tp.DeclaredPosition] ?? parameter;
3426
3427 return parameter;
3428 }
3429
3430 var gt = parameter as InflatedTypeSpec;
3431 if (gt != null) {
3432 var inflated_targs = new TypeSpec [gt.TypeArguments.Length];
3433 for (int ii = 0; ii < inflated_targs.Length; ++ii) {
3434 var inflated = InflateGenericArgument (context, gt.TypeArguments [ii]);
3435 if (inflated == null)
3436 return null;
3437
3438 inflated_targs[ii] = inflated;
3439 }
3440
3441 return gt.GetDefinition ().MakeGenericType (context, inflated_targs);
3442 }
3443
3444 var ac = parameter as ArrayContainer;
3445 if (ac != null) {
3446 var inflated = InflateGenericArgument (context, ac.Element);
3447 if (inflated != ac.Element)
3448 return ArrayContainer.MakeType (context.Module, inflated);
3449 }
3450
3451 return parameter;
3452 }
3453
3454 //
3455 // Tests whether all delegate input arguments are fixed and generic output type
3456 // requires output type inference
3457 //
3458 public bool IsReturnTypeNonDependent (MethodSpec invoke, TypeSpec returnType)
3459 {
3460 AParametersCollection d_parameters = invoke.Parameters;
3461
3462 if (d_parameters.IsEmpty)
3463 return true;
3464
3465 while (returnType.IsArray)
3466 returnType = ((ArrayContainer) returnType).Element;
3467
3468 if (returnType.IsGenericParameter) {
3469 if (IsFixed (returnType))
3470 return false;
3471 } else if (TypeManager.IsGenericType (returnType)) {
3472 TypeSpec[] g_args = TypeManager.GetTypeArguments (returnType);
3473
3474 // At least one unfixed return type has to exist
3475 if (AllTypesAreFixed (g_args))
3476 return false;
3477 } else {
3478 return false;
3479 }
3480
3481 // All generic input arguments have to be fixed
3482 return AllTypesAreFixed (d_parameters.Types);
3483 }
3484
3485 bool IsFixed (TypeSpec type)
3486 {
3487 return IsUnfixed (type) == -1;
3488 }
3489
3490 int IsUnfixed (TypeSpec type)
3491 {
3492 if (!type.IsGenericParameter)
3493 return -1;
3494
3495 for (int i = 0; i < tp_args.Length; ++i) {
3496 if (tp_args[i] == type) {
3497 if (fixed_types[i] != null)
3498 break;
3499
3500 return i;
3501 }
3502 }
3503
3504 return -1;
3505 }
3506
3507 //
3508 // 26.3.3.9 Lower-bound Inference
3509 //
3510 public int LowerBoundInference (TypeSpec u, TypeSpec v)
3511 {
3512 return LowerBoundInference (u, v, false);
3513 }
3514
3515 //
3516 // Lower-bound (false) or Upper-bound (true) inference based on inversed argument
3517 //
3518 int LowerBoundInference (TypeSpec u, TypeSpec v, bool inversed)
3519 {
3520 // If V is one of the unfixed type arguments
3521 int pos = IsUnfixed (v);
3522 if (pos != -1) {
3523 AddToBounds (new BoundInfo (u, inversed ? BoundKind.Upper : BoundKind.Lower), pos, false);
3524 return 1;
3525 }
3526
3527 // If U is an array type
3528 var u_ac = u as ArrayContainer;
3529 if (u_ac != null) {
3530 var v_ac = v as ArrayContainer;
3531 if (v_ac != null) {
3532 if (u_ac.Rank != v_ac.Rank)
3533 return 0;
3534
3535 if (TypeSpec.IsValueType (u_ac.Element))
3536 return ExactInference (u_ac.Element, v_ac.Element);
3537
3538 return LowerBoundInference (u_ac.Element, v_ac.Element, inversed);
3539 }
3540
3541 if (u_ac.Rank != 1 || !v.IsArrayGenericInterface)
3542 return 0;
3543
3544 var v_i = TypeManager.GetTypeArguments (v) [0];
3545 if (TypeSpec.IsValueType (u_ac.Element))
3546 return ExactInference (u_ac.Element, v_i);
3547
3548 return LowerBoundInference (u_ac.Element, v_i);
3549 }
3550
3551 if (v.IsGenericOrParentIsGeneric) {
3552 //
3553 // if V is a constructed type C<V1..Vk> and there is a unique type C<U1..Uk>
3554 // such that U is identical to, inherits from (directly or indirectly),
3555 // or implements (directly or indirectly) C<U1..Uk>
3556 //
3557 var u_candidates = new List<TypeSpec> ();
3558 var open_v = v.MemberDefinition;
3559
3560 for (TypeSpec t = u; t != null; t = t.BaseType) {
3561 if (open_v == t.MemberDefinition)
3562 u_candidates.Add (t);
3563
3564 //
3565 // Using this trick for dynamic type inference, the spec says the type arguments are "unknown" but
3566 // that would complicate the process a lot, instead I treat them as dynamic
3567 //
3568 if (t.BuiltinType == BuiltinTypeSpec.Type.Dynamic)
3569 u_candidates.Add (t);
3570 }
3571
3572 if (u.Interfaces != null) {
3573 foreach (var iface in u.Interfaces) {
3574 if (open_v == iface.MemberDefinition)
3575 u_candidates.Add (iface);
3576 }
3577 }
3578
3579 TypeSpec[] unique_candidate_targs = null;
3580 var ga_v = TypeSpec.GetAllTypeArguments (v);
3581 foreach (TypeSpec u_candidate in u_candidates) {
3582 //
3583 // The unique set of types U1..Uk means that if we have an interface I<T>,
3584 // class U : I<int>, I<long> then no type inference is made when inferring
3585 // type I<T> by applying type U because T could be int or long
3586 //
3587 if (unique_candidate_targs != null) {
3588 TypeSpec[] second_unique_candidate_targs = TypeSpec.GetAllTypeArguments (u_candidate);
3589 if (TypeSpecComparer.Equals (unique_candidate_targs, second_unique_candidate_targs)) {
3590 unique_candidate_targs = second_unique_candidate_targs;
3591 continue;
3592 }
3593
3594 //
3595 // Break when candidate arguments are ambiguous
3596 //
3597 return 0;
3598 }
3599
3600 //
3601 // A candidate is dynamic type expression, to simplify things use dynamic
3602 // for all type parameter of this type. For methods like this one
3603 //
3604 // void M<T, U> (IList<T>, IList<U[]>)
3605 //
3606 // dynamic becomes both T and U when the arguments are of dynamic type
3607 //
3608 if (u_candidate.BuiltinType == BuiltinTypeSpec.Type.Dynamic) {
3609 unique_candidate_targs = new TypeSpec[ga_v.Length];
3610 for (int i = 0; i < unique_candidate_targs.Length; ++i)
3611 unique_candidate_targs[i] = u_candidate;
3612 } else {
3613 unique_candidate_targs = TypeSpec.GetAllTypeArguments (u_candidate);
3614 }
3615 }
3616
3617 if (unique_candidate_targs != null) {
3618 int score = 0;
3619 int tp_index = -1;
3620 TypeParameterSpec[] tps = null;
3621
3622 for (int i = 0; i < unique_candidate_targs.Length; ++i) {
3623 if (tp_index < 0) {
3624 while (v.Arity == 0)
3625 v = v.DeclaringType;
3626
3627 tps = v.MemberDefinition.TypeParameters;
3628 tp_index = tps.Length - 1;
3629 }
3630
3631 Variance variance = tps [tp_index--].Variance;
3632
3633 TypeSpec u_i = unique_candidate_targs [i];
3634 if (variance == Variance.None || TypeSpec.IsValueType (u_i)) {
3635 if (ExactInference (u_i, ga_v [i]) == 0)
3636 ++score;
3637 } else {
3638 bool upper_bound = (variance == Variance.Contravariant && !inversed) ||
3639 (variance == Variance.Covariant && inversed);
3640
3641 if (LowerBoundInference (u_i, ga_v [i], upper_bound) == 0)
3642 ++score;
3643 }
3644 }
3645
3646 return score;
3647 }
3648 }
3649
3650 return 0;
3651 }
3652
3653 //
3654 // 26.3.3.6 Output Type Inference
3655 //
3656 public int OutputTypeInference (ResolveContext ec, Expression e, TypeSpec t)
3657 {
3658 // If e is a lambda or anonymous method with inferred return type
3659 AnonymousMethodExpression ame = e as AnonymousMethodExpression;
3660 if (ame != null) {
3661 TypeSpec rt = ame.InferReturnType (ec, this, t);
3662 var invoke = Delegate.GetInvokeMethod (t);
3663
3664 if (rt == null) {
3665 AParametersCollection pd = invoke.Parameters;
3666 return ame.Parameters.Count == pd.Count ? 1 : 0;
3667 }
3668
3669 TypeSpec rtype = invoke.ReturnType;
3670 return LowerBoundInference (rt, rtype) + 1;
3671 }
3672
3673 //
3674 // if E is a method group and T is a delegate type or expression tree type
3675 // return type Tb with parameter types T1..Tk and return type Tb, and overload
3676 // resolution of E with the types T1..Tk yields a single method with return type U,
3677 // then a lower-bound inference is made from U for Tb.
3678 //
3679 if (e is MethodGroupExpr) {
3680 if (!t.IsDelegate) {
3681 if (!t.IsExpressionTreeType)
3682 return 0;
3683
3684 t = TypeManager.GetTypeArguments (t)[0];
3685 }
3686
3687 var invoke = Delegate.GetInvokeMethod (t);
3688 TypeSpec rtype = invoke.ReturnType;
3689
3690 if (!IsReturnTypeNonDependent (invoke, rtype))
3691 return 0;
3692
3693 // LAMESPEC: Standard does not specify that all methodgroup arguments
3694 // has to be fixed but it does not specify how to do recursive type inference
3695 // either. We choose the simple option and infer return type only
3696 // if all delegate generic arguments are fixed.
3697 TypeSpec[] param_types = new TypeSpec [invoke.Parameters.Count];
3698 for (int i = 0; i < param_types.Length; ++i) {
3699 var inflated = InflateGenericArgument (ec, invoke.Parameters.Types[i]);
3700 if (inflated == null)
3701 return 0;
3702
3703 param_types[i] = inflated;
3704 }
3705
3706 MethodGroupExpr mg = (MethodGroupExpr) e;
3707 Arguments args = DelegateCreation.CreateDelegateMethodArguments (ec, invoke.Parameters, param_types, e.Location);
3708 mg = mg.OverloadResolve (ec, ref args, null, OverloadResolver.Restrictions.CovariantDelegate | OverloadResolver.Restrictions.ProbingOnly);
3709 if (mg == null)
3710 return 0;
3711
3712 return LowerBoundInference (mg.BestCandidateReturnType, rtype) + 1;
3713 }
3714
3715 //
3716 // if e is an expression with type U, then
3717 // a lower-bound inference is made from U for T
3718 //
3719 return LowerBoundInference (e.Type, t) * 2;
3720 }
3721
3722 void RemoveDependentTypes (List<TypeSpec> types, TypeSpec returnType)
3723 {
3724 int idx = IsUnfixed (returnType);
3725 if (idx >= 0) {
3726 types [idx] = null;
3727 return;
3728 }
3729
3730 if (TypeManager.IsGenericType (returnType)) {
3731 foreach (TypeSpec t in TypeManager.GetTypeArguments (returnType)) {
3732 RemoveDependentTypes (types, t);
3733 }
3734 }
3735 }
3736
3737 public bool UnfixedVariableExists {
3738 get {
3739 foreach (TypeSpec ut in fixed_types) {
3740 if (ut == null)
3741 return true;
3742 }
3743
3744 return false;
3745 }
3746 }
3747 }
3748 }
Mirror of the official Mono project git repository