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**** Merged from MCS ****
[mono-project.git] / mcs / mcs / delegate.cs
blobce1ef17f17b7c3bdc9e2bb152f2899110d465378
1 //
2 // delegate.cs: Delegate Handler
3 //
4 // Authors:
5 // Ravi Pratap (ravi@ximian.com)
6 // Miguel de Icaza (miguel@ximian.com)
7 //
8 // Licensed under the terms of the GNU GPL
9 //
10 // (C) 2001 Ximian, Inc (http://www.ximian.com)
11 //
12 //
13
14 using System;
15 using System.Collections;
16 using System.Reflection;
17 using System.Reflection.Emit;
18 using System.Text;
19
20 namespace Mono.CSharp {
21
22 /// <summary>
23 /// Holds Delegates
24 /// </summary>
25 public class Delegate : DeclSpace {
26 public Expression ReturnType;
27 public Parameters Parameters;
28
29 public ConstructorBuilder ConstructorBuilder;
30 public MethodBuilder InvokeBuilder;
31 public MethodBuilder BeginInvokeBuilder;
32 public MethodBuilder EndInvokeBuilder;
33
34 Type [] param_types;
35 Type ret_type;
36
37 static string[] attribute_targets = new string [] { "type", "return" };
38
39 Expression instance_expr;
40 MethodBase delegate_method;
41 ReturnParameter return_attributes;
42
43 const int AllowedModifiers =
44 Modifiers.NEW |
45 Modifiers.PUBLIC |
46 Modifiers.PROTECTED |
47 Modifiers.INTERNAL |
48 Modifiers.UNSAFE |
49 Modifiers.PRIVATE;
50
51 public Delegate (NamespaceEntry ns, TypeContainer parent, Expression type,
52 int mod_flags, MemberName name, Parameters param_list,
53 Attributes attrs, Location l)
54 : base (ns, parent, name, attrs, l)
55
56 {
57 this.ReturnType = type;
58 ModFlags = Modifiers.Check (AllowedModifiers, mod_flags,
59 IsTopLevel ? Modifiers.INTERNAL :
60 Modifiers.PRIVATE, l);
61 Parameters = param_list;
62 }
63
64 public override void ApplyAttributeBuilder(Attribute a, CustomAttributeBuilder cb)
65 {
66 if (a.Target == AttributeTargets.ReturnValue) {
67 if (return_attributes == null)
68 return_attributes = new ReturnParameter (InvokeBuilder, Location);
69
70 return_attributes.ApplyAttributeBuilder (a, cb);
71 return;
72 }
73
74 base.ApplyAttributeBuilder (a, cb);
75 }
76
77 public override TypeBuilder DefineType ()
78 {
79 if (TypeBuilder != null)
80 return TypeBuilder;
81
82 TypeAttributes attr = Modifiers.TypeAttr (ModFlags, IsTopLevel) |
83 TypeAttributes.Class | TypeAttributes.Sealed;
84
85 if (IsTopLevel) {
86 if (TypeManager.NamespaceClash (Name, Location))
87 return null;
88
89 ModuleBuilder builder = CodeGen.Module.Builder;
90
91 TypeBuilder = builder.DefineType (
92 Name, attr, TypeManager.multicast_delegate_type);
93 } else {
94 TypeBuilder builder = Parent.TypeBuilder;
95
96 string name = Name.Substring (1 + Name.LastIndexOf ('.'));
97 TypeBuilder = builder.DefineNestedType (
98 name, attr, TypeManager.multicast_delegate_type);
99 }
100
101 TypeManager.AddDelegateType (Name, TypeBuilder, this);
102
103 return TypeBuilder;
104 }
105
106 public override bool DefineMembers (TypeContainer container)
107 {
108 return true;
109 }
110
111 public override bool Define ()
112 {
113 MethodAttributes mattr;
114 int i;
115 EmitContext ec = new EmitContext (this, this, Location, null,
116 null, ModFlags, false);
117
118 // FIXME: POSSIBLY make this static, as it is always constant
119 //
120 Type [] const_arg_types = new Type [2];
121 const_arg_types [0] = TypeManager.object_type;
122 const_arg_types [1] = TypeManager.intptr_type;
123
124 mattr = MethodAttributes.RTSpecialName | MethodAttributes.SpecialName |
125 MethodAttributes.HideBySig | MethodAttributes.Public;
126
127 ConstructorBuilder = TypeBuilder.DefineConstructor (mattr,
128 CallingConventions.Standard,
129 const_arg_types);
130
131 ConstructorBuilder.DefineParameter (1, ParameterAttributes.None, "object");
132 ConstructorBuilder.DefineParameter (2, ParameterAttributes.None, "method");
133 //
134 // HACK because System.Reflection.Emit is lame
135 //
136 //
137 // FIXME: POSSIBLY make these static, as they are always the same
138 Parameter [] fixed_pars = new Parameter [2];
139 fixed_pars [0] = new Parameter (TypeManager.system_object_expr, "object",
140 Parameter.Modifier.NONE, null);
141 fixed_pars [1] = new Parameter (TypeManager.system_intptr_expr, "method",
142 Parameter.Modifier.NONE, null);
143 Parameters const_parameters = new Parameters (fixed_pars, null, Location);
144
145 TypeManager.RegisterMethod (
146 ConstructorBuilder,
147 new InternalParameters (const_arg_types, const_parameters),
148 const_arg_types);
149
150
151 ConstructorBuilder.SetImplementationFlags (MethodImplAttributes.Runtime);
152
153 //
154 // Here the various methods like Invoke, BeginInvoke etc are defined
155 //
156 // First, call the `out of band' special method for
157 // defining recursively any types we need:
158
159 if (!Parameters.ComputeAndDefineParameterTypes (ec))
160 return false;
161
162 param_types = Parameters.GetParameterInfo (ec);
163 if (param_types == null)
164 return false;
165
166 //
167 // Invoke method
168 //
169
170 // Check accessibility
171 foreach (Type partype in param_types){
172 if (!Parent.AsAccessible (partype, ModFlags)) {
173 Report.Error (59, Location,
174 "Inconsistent accessibility: parameter type `" +
175 TypeManager.CSharpName (partype) + "` is less " +
176 "accessible than delegate `" + Name + "'");
177 return false;
178 }
179 if (partype.IsPointer && !UnsafeOK (Parent))
180 return false;
181 }
182
183 ReturnType = ReturnType.ResolveAsTypeTerminal (ec, false);
184 if (ReturnType == null)
185 return false;
186
187 ret_type = ReturnType.Type;
188 if (ret_type == null)
189 return false;
190
191 if (!Parent.AsAccessible (ret_type, ModFlags)) {
192 Report.Error (58, Location,
193 "Inconsistent accessibility: return type `" +
194 TypeManager.CSharpName (ret_type) + "` is less " +
195 "accessible than delegate `" + Name + "'");
196 return false;
197 }
198
199 if (ret_type.IsPointer && !UnsafeOK (Parent))
200 return false;
201
202 //
203 // We don't have to check any others because they are all
204 // guaranteed to be accessible - they are standard types.
205 //
206
207 CallingConventions cc = Parameters.GetCallingConvention ();
208
209 mattr = MethodAttributes.Public | MethodAttributes.HideBySig | MethodAttributes.Virtual;
210
211 InvokeBuilder = TypeBuilder.DefineMethod ("Invoke",
212 mattr,
213 cc,
214 ret_type,
215 param_types);
216
217 //
218 // Define parameters, and count out/ref parameters
219 //
220 int out_params = 0;
221 i = 0;
222 if (Parameters.FixedParameters != null){
223 int top = Parameters.FixedParameters.Length;
224 Parameter p;
225
226 for (; i < top; i++) {
227 p = Parameters.FixedParameters [i];
228 p.DefineParameter (ec, InvokeBuilder, null, i + 1, Location);
229
230 if ((p.ModFlags & Parameter.Modifier.ISBYREF) != 0)
231 out_params++;
232 }
233 }
234 if (Parameters.ArrayParameter != null){
235 Parameter p = Parameters.ArrayParameter;
236 p.DefineParameter (ec, InvokeBuilder, null, i + 1, Location);
237 }
238
239 InvokeBuilder.SetImplementationFlags (MethodImplAttributes.Runtime);
240
241 TypeManager.RegisterMethod (InvokeBuilder,
242 new InternalParameters (param_types, Parameters),
243 param_types);
244
245 //
246 // BeginInvoke
247 //
248 int params_num = param_types.Length;
249 Type [] async_param_types = new Type [params_num + 2];
250
251 param_types.CopyTo (async_param_types, 0);
252
253 async_param_types [params_num] = TypeManager.asynccallback_type;
254 async_param_types [params_num + 1] = TypeManager.object_type;
255
256 mattr = MethodAttributes.Public | MethodAttributes.HideBySig |
257 MethodAttributes.Virtual | MethodAttributes.NewSlot;
258
259 BeginInvokeBuilder = TypeBuilder.DefineMethod ("BeginInvoke",
260 mattr,
261 cc,
262 TypeManager.iasyncresult_type,
263 async_param_types);
264
265 i = 0;
266 if (Parameters.FixedParameters != null){
267 int top = Parameters.FixedParameters.Length;
268 Parameter p;
269
270 for (i = 0 ; i < top; i++) {
271 p = Parameters.FixedParameters [i];
272
273 p.DefineParameter (ec, BeginInvokeBuilder, null, i + 1, Location);
274 }
275 }
276 if (Parameters.ArrayParameter != null){
277 Parameter p = Parameters.ArrayParameter;
278 p.DefineParameter (ec, BeginInvokeBuilder, null, i + 1, Location);
279
280 i++;
281 }
282
283 BeginInvokeBuilder.DefineParameter (i + 1, ParameterAttributes.None, "callback");
284 BeginInvokeBuilder.DefineParameter (i + 2, ParameterAttributes.None, "object");
285
286 BeginInvokeBuilder.SetImplementationFlags (MethodImplAttributes.Runtime);
287
288 Parameter [] async_params = new Parameter [params_num + 2];
289 int n = 0;
290 if (Parameters.FixedParameters != null){
291 Parameters.FixedParameters.CopyTo (async_params, 0);
292 n = Parameters.FixedParameters.Length;
293 }
294 if (Parameters.ArrayParameter != null)
295 async_params [n] = Parameters.ArrayParameter;
296
297 async_params [params_num] = new Parameter (
298 TypeManager.system_asynccallback_expr, "callback",
299 Parameter.Modifier.NONE, null);
300 async_params [params_num + 1] = new Parameter (
301 TypeManager.system_object_expr, "object",
302 Parameter.Modifier.NONE, null);
303
304 Parameters async_parameters = new Parameters (async_params, null, Location);
305 async_parameters.ComputeAndDefineParameterTypes (ec);
306
307 TypeManager.RegisterMethod (BeginInvokeBuilder,
308 new InternalParameters (async_param_types, async_parameters),
309 async_param_types);
310
311 //
312 // EndInvoke is a bit more interesting, all the parameters labeled as
313 // out or ref have to be duplicated here.
314 //
315
316 Type [] end_param_types = new Type [out_params + 1];
317 Parameter [] end_params = new Parameter [out_params + 1];
318 int param = 0;
319 if (out_params > 0){
320 int top = Parameters.FixedParameters.Length;
321 for (i = 0; i < top; i++){
322 Parameter p = Parameters.FixedParameters [i];
323 if ((p.ModFlags & Parameter.Modifier.ISBYREF) == 0)
324 continue;
325
326 end_param_types [param] = param_types [i];
327 end_params [param] = p;
328 param++;
329 }
330 }
331 end_param_types [out_params] = TypeManager.iasyncresult_type;
332 end_params [out_params] = new Parameter (TypeManager.system_iasyncresult_expr, "result", Parameter.Modifier.NONE, null);
333
334 //
335 // Create method, define parameters, register parameters with type system
336 //
337 EndInvokeBuilder = TypeBuilder.DefineMethod ("EndInvoke", mattr, cc, ret_type, end_param_types);
338 EndInvokeBuilder.SetImplementationFlags (MethodImplAttributes.Runtime);
339
340 //
341 // EndInvoke: Label the parameters
342 //
343 EndInvokeBuilder.DefineParameter (out_params + 1, ParameterAttributes.None, "result");
344 for (i = 0; i < end_params.Length-1; i++){
345 EndInvokeBuilder.DefineParameter (i + 1, end_params [i].Attributes, end_params [i].Name);
346 }
347
348 Parameters end_parameters = new Parameters (end_params, null, Location);
349 end_parameters.ComputeAndDefineParameterTypes (ec);
350
351 TypeManager.RegisterMethod (
352 EndInvokeBuilder,
353 new InternalParameters (end_param_types, end_parameters),
354 end_param_types);
355
356 return true;
357 }
358
359 public override void Emit ()
360 {
361 if (OptAttributes != null) {
362 EmitContext ec = new EmitContext (
363 Parent, this, Location, null, null, ModFlags, false);
364 Parameters.LabelParameters (ec, InvokeBuilder, Location);
365 OptAttributes.Emit (ec, this);
366 }
367
368 base.Emit ();
369 }
370
371 public override string[] ValidAttributeTargets {
372 get {
373 return attribute_targets;
374 }
375 }
376
377 //TODO: duplicate
378 protected override bool VerifyClsCompliance (DeclSpace ds)
379 {
380 if (!base.VerifyClsCompliance (ds)) {
381 return false;
382 }
383
384 AttributeTester.AreParametersCompliant (Parameters.FixedParameters, Location);
385
386 if (!AttributeTester.IsClsCompliant (ReturnType.Type)) {
387 Report.Error (3002, Location, "Return type of '{0}' is not CLS-compliant", GetSignatureForError ());
388 }
389 return true;
390 }
391
392 //
393 // Returns the MethodBase for "Invoke" from a delegate type, this is used
394 // to extract the signature of a delegate.
395 //
396 public static MethodInfo GetInvokeMethod (EmitContext ec, Type delegate_type, Location loc)
397 {
398 Expression ml = Expression.MemberLookup (
399 ec, delegate_type, "Invoke", loc);
400
401 if (!(ml is MethodGroupExpr)) {
402 Report.Error (-100, loc, "Internal error: could not find Invoke method!");
403 return null;
404 }
405
406 return (MethodInfo) (((MethodGroupExpr) ml).Methods [0]);
407 }
408
409 /// <summary>
410 /// Verifies whether the method in question is compatible with the delegate
411 /// Returns the method itself if okay and null if not.
412 /// </summary>
413 public static MethodBase VerifyMethod (EmitContext ec, Type delegate_type, MethodBase mb,
414 Location loc)
415 {
416 ParameterData pd = Invocation.GetParameterData (mb);
417
418 int pd_count = pd.Count;
419
420 MethodBase invoke_mb = GetInvokeMethod (ec, delegate_type, loc);
421 if (invoke_mb == null)
422 return null;
423
424 ParameterData invoke_pd = Invocation.GetParameterData (invoke_mb);
425
426 if (invoke_pd.Count != pd_count)
427 return null;
428
429 for (int i = pd_count; i > 0; ) {
430 i--;
431
432 if (invoke_pd.ParameterType (i) == pd.ParameterType (i) &&
433 invoke_pd.ParameterModifier (i) == pd.ParameterModifier (i))
434 continue;
435 else {
436 return null;
437 }
438 }
439
440 if (((MethodInfo) invoke_mb).ReturnType == ((MethodInfo) mb).ReturnType)
441 return mb;
442 else
443 return null;
444 }
445
446 // <summary>
447 // Verifies whether the invocation arguments are compatible with the
448 // delegate's target method
449 // </summary>
450 public static bool VerifyApplicability (EmitContext ec, Type delegate_type,
451 ArrayList args, Location loc)
452 {
453 int arg_count;
454
455 if (args == null)
456 arg_count = 0;
457 else
458 arg_count = args.Count;
459
460 Expression ml = Expression.MemberLookup (
461 ec, delegate_type, "Invoke", loc);
462
463 if (!(ml is MethodGroupExpr)) {
464 Report.Error (-100, loc, "Internal error: could not find Invoke method!" + delegate_type);
465 return false;
466 }
467
468 MethodBase mb = ((MethodGroupExpr) ml).Methods [0];
469 ParameterData pd = Invocation.GetParameterData (mb);
470
471 int pd_count = pd.Count;
472
473 bool params_method = (pd_count != 0) &&
474 (pd.ParameterModifier (pd_count - 1) == Parameter.Modifier.PARAMS);
475
476 if (!params_method && pd_count != arg_count) {
477 Report.Error (1593, loc,
478 "Delegate '{0}' does not take {1} arguments",
479 delegate_type.ToString (), arg_count);
480 return false;
481 }
482
483 //
484 // Consider the case:
485 // delegate void FOO(param object[] args);
486 // FOO f = new FOO(...);
487 // f(new object[] {1, 2, 3});
488 //
489 // This should be treated like f(1,2,3). This is done by ignoring the
490 // 'param' modifier for that invocation. If that fails, then the
491 // 'param' modifier is considered.
492 //
493 // One issue is that 'VerifyArgumentsCompat' modifies the elements of
494 // the 'args' array. However, the modifications appear idempotent.
495 // Normal 'Invocation's also have the same behaviour, implicitly.
496 //
497
498 bool ans = false;
499 if (arg_count == pd_count)
500 ans = Invocation.VerifyArgumentsCompat (
501 ec, args, arg_count, mb, false,
502 delegate_type, false, loc);
503 if (!ans && params_method)
504 ans = Invocation.VerifyArgumentsCompat (
505 ec, args, arg_count, mb, true,
506 delegate_type, false, loc);
507 return ans;
508 }
509
510 /// <summary>
511 /// Verifies whether the delegate in question is compatible with this one in
512 /// order to determine if instantiation from the same is possible.
513 /// </summary>
514 public static bool VerifyDelegate (EmitContext ec, Type delegate_type, Type probe_type, Location loc)
515 {
516 Expression ml = Expression.MemberLookup (
517 ec, delegate_type, "Invoke", loc);
518
519 if (!(ml is MethodGroupExpr)) {
520 Report.Error (-100, loc, "Internal error: could not find Invoke method!");
521 return false;
522 }
523
524 MethodBase mb = ((MethodGroupExpr) ml).Methods [0];
525 ParameterData pd = Invocation.GetParameterData (mb);
526
527 Expression probe_ml = Expression.MemberLookup (
528 ec, delegate_type, "Invoke", loc);
529
530 if (!(probe_ml is MethodGroupExpr)) {
531 Report.Error (-100, loc, "Internal error: could not find Invoke method!");
532 return false;
533 }
534
535 MethodBase probe_mb = ((MethodGroupExpr) probe_ml).Methods [0];
536 ParameterData probe_pd = Invocation.GetParameterData (probe_mb);
537
538 if (((MethodInfo) mb).ReturnType != ((MethodInfo) probe_mb).ReturnType)
539 return false;
540
541 if (pd.Count != probe_pd.Count)
542 return false;
543
544 for (int i = pd.Count; i > 0; ) {
545 i--;
546
547 if (pd.ParameterType (i) != probe_pd.ParameterType (i) ||
548 pd.ParameterModifier (i) != probe_pd.ParameterModifier (i))
549 return false;
550 }
551
552 return true;
553 }
554
555 public static string FullDelegateDesc (Type del_type, MethodBase mb, ParameterData pd)
556 {
557 StringBuilder sb = new StringBuilder (TypeManager.CSharpName (((MethodInfo) mb).ReturnType));
558
559 sb.Append (" " + del_type.ToString ());
560 sb.Append (" (");
561
562 int length = pd.Count;
563
564 for (int i = length; i > 0; ) {
565 i--;
566
567 sb.Append (pd.ParameterDesc (length - i - 1));
568 if (i != 0)
569 sb.Append (", ");
570 }
571
572 sb.Append (")");
573 return sb.ToString ();
574
575 }
576
577 // Hack around System.Reflection as found everywhere else
578 public override MemberList FindMembers (MemberTypes mt, BindingFlags bf,
579 MemberFilter filter, object criteria)
580 {
581 ArrayList members = new ArrayList ();
582
583 if ((mt & MemberTypes.Method) != 0) {
584 if (ConstructorBuilder != null)
585 if (filter (ConstructorBuilder, criteria))
586 members.Add (ConstructorBuilder);
587
588 if (InvokeBuilder != null)
589 if (filter (InvokeBuilder, criteria))
590 members.Add (InvokeBuilder);
591
592 if (BeginInvokeBuilder != null)
593 if (filter (BeginInvokeBuilder, criteria))
594 members.Add (BeginInvokeBuilder);
595
596 if (EndInvokeBuilder != null)
597 if (filter (EndInvokeBuilder, criteria))
598 members.Add (EndInvokeBuilder);
599 }
600
601 return new MemberList (members);
602 }
603
604 public override MemberCache MemberCache {
605 get {
606 return null;
607 }
608 }
609
610 public Expression InstanceExpression {
611 get {
612 return instance_expr;
613 }
614 set {
615 instance_expr = value;
616 }
617 }
618
619 public MethodBase TargetMethod {
620 get {
621 return delegate_method;
622 }
623 set {
624 delegate_method = value;
625 }
626 }
627
628 public Type TargetReturnType {
629 get {
630 return ret_type;
631 }
632 }
633
634 public Type [] ParameterTypes {
635 get {
636 return param_types;
637 }
638 }
639
640 public override AttributeTargets AttributeTargets {
641 get {
642 return AttributeTargets.Delegate;
643 }
644 }
645
646 protected override void VerifyObsoleteAttribute()
647 {
648 CheckUsageOfObsoleteAttribute (ret_type);
649
650 foreach (Type type in param_types) {
651 CheckUsageOfObsoleteAttribute (type);
652 }
653 }
654 }
655
656 //
657 // Base class for `NewDelegate' and `ImplicitDelegateCreation'
658 //
659 public abstract class DelegateCreation : Expression {
660 protected MethodBase constructor_method;
661 protected MethodBase delegate_method;
662 protected MethodGroupExpr method_group;
663 protected Expression delegate_instance_expression;
664
665 public DelegateCreation () {}
666
667 public static void Error_NoMatchingMethodForDelegate (EmitContext ec, MethodGroupExpr mg, Type type, Location loc)
668 {
669 string method_desc;
670
671 if (mg.Methods.Length > 1)
672 method_desc = mg.Methods [0].Name;
673 else
674 method_desc = Invocation.FullMethodDesc (mg.Methods [0]);
675
676 Expression invoke_method = Expression.MemberLookup (
677 ec, type, "Invoke", MemberTypes.Method,
678 Expression.AllBindingFlags, loc);
679 MethodBase method = ((MethodGroupExpr) invoke_method).Methods [0];
680 ParameterData param = Invocation.GetParameterData (method);
681 string delegate_desc = Delegate.FullDelegateDesc (type, method, param);
682
683 Report.Error (123, loc, "Method '" + method_desc + "' does not " +
684 "match delegate '" + delegate_desc + "'");
685 }
686
687 public override void Emit (EmitContext ec)
688 {
689 if (delegate_instance_expression == null || delegate_method.IsStatic)
690 ec.ig.Emit (OpCodes.Ldnull);
691 else
692 delegate_instance_expression.Emit (ec);
693
694 if (delegate_method.IsVirtual && !method_group.IsBase) {
695 ec.ig.Emit (OpCodes.Dup);
696 ec.ig.Emit (OpCodes.Ldvirtftn, (MethodInfo) delegate_method);
697 } else
698 ec.ig.Emit (OpCodes.Ldftn, (MethodInfo) delegate_method);
699 ec.ig.Emit (OpCodes.Newobj, (ConstructorInfo) constructor_method);
700 }
701
702 protected bool ResolveConstructorMethod (EmitContext ec)
703 {
704 Expression ml = Expression.MemberLookup (
705 ec, type, ".ctor", loc);
706
707 if (!(ml is MethodGroupExpr)) {
708 Report.Error (-100, loc, "Internal error: Could not find delegate constructor!");
709 return false;
710 }
711
712 constructor_method = ((MethodGroupExpr) ml).Methods [0];
713 return true;
714 }
715
716 protected Expression ResolveMethodGroupExpr (EmitContext ec, MethodGroupExpr mg)
717 {
718 foreach (MethodInfo mi in mg.Methods){
719 delegate_method = Delegate.VerifyMethod (ec, type, mi, loc);
720
721 if (delegate_method != null)
722 break;
723 }
724
725 if (delegate_method == null) {
726 Error_NoMatchingMethodForDelegate (ec, mg, type, loc);
727 return null;
728 }
729
730 //
731 // Check safe/unsafe of the delegate
732 //
733 if (!ec.InUnsafe){
734 ParameterData param = Invocation.GetParameterData (delegate_method);
735 int count = param.Count;
736
737 for (int i = 0; i < count; i++){
738 if (param.ParameterType (i).IsPointer){
739 Expression.UnsafeError (loc);
740 return null;
741 }
742 }
743 }
744
745 //TODO: implement caching when performance will be low
746 IMethodData md = TypeManager.GetMethod (delegate_method);
747 if (md == null) {
748 if (System.Attribute.GetCustomAttribute (delegate_method, TypeManager.conditional_attribute_type) != null) {
749 Report.Error (1618, loc, "Cannot create delegate with '{0}' because it has a Conditional attribute", TypeManager.CSharpSignature (delegate_method));
750 }
751 } else {
752 if (md.OptAttributes != null && md.OptAttributes.Search (TypeManager.conditional_attribute_type, ec) != null) {
753 Report.Error (1618, loc, "Cannot create delegate with '{0}' because it has a Conditional attribute", TypeManager.CSharpSignature (delegate_method));
754 }
755 }
756
757 if (mg.InstanceExpression != null)
758 delegate_instance_expression = mg.InstanceExpression.Resolve (ec);
759 else if (ec.IsStatic) {
760 if (!delegate_method.IsStatic) {
761 Report.Error (120, loc,
762 "An object reference is required for the non-static method " +
763 delegate_method.Name);
764 return null;
765 }
766 delegate_instance_expression = null;
767 } else
768 delegate_instance_expression = ec.GetThis (loc);
769
770 if (delegate_instance_expression != null && delegate_instance_expression.Type.IsValueType)
771 delegate_instance_expression = new BoxedCast (mg.InstanceExpression);
772
773 method_group = mg;
774 eclass = ExprClass.Value;
775 return this;
776 }
777 }
778
779 //
780 // Created from the conversion code
781 //
782 public class ImplicitDelegateCreation : DelegateCreation {
783
784 ImplicitDelegateCreation (Type t, Location l)
785 {
786 type = t;
787 loc = l;
788 }
789
790 public override Expression DoResolve (EmitContext ec)
791 {
792 return this;
793 }
794
795 static public Expression Create (EmitContext ec, MethodGroupExpr mge, Type target_type, Location loc)
796 {
797 ImplicitDelegateCreation d = new ImplicitDelegateCreation (target_type, loc);
798 if (d.ResolveConstructorMethod (ec))
799 return d.ResolveMethodGroupExpr (ec, mge);
800 else
801 return null;
802 }
803 }
804
805 //
806 // A delegate-creation-expression, invoked from the `New' class
807 //
808 public class NewDelegate : DelegateCreation {
809 public ArrayList Arguments;
810
811 //
812 // This constructor is invoked from the `New' expression
813 //
814 public NewDelegate (Type type, ArrayList Arguments, Location loc)
815 {
816 this.type = type;
817 this.Arguments = Arguments;
818 this.loc = loc;
819 }
820
821 public override Expression DoResolve (EmitContext ec)
822 {
823 if (Arguments == null || Arguments.Count != 1) {
824 Report.Error (149, loc,
825 "Method name expected");
826 return null;
827 }
828
829 if (!ResolveConstructorMethod (ec))
830 return null;
831
832 Argument a = (Argument) Arguments [0];
833
834 if (!a.ResolveMethodGroup (ec, loc))
835 return null;
836
837 Expression e = a.Expr;
838
839 MethodGroupExpr mg = e as MethodGroupExpr;
840 if (mg != null)
841 return ResolveMethodGroupExpr (ec, mg);
842
843 Type e_type = e.Type;
844
845 if (!TypeManager.IsDelegateType (e_type)) {
846 e.Error_UnexpectedKind ("method", loc);
847 return null;
848 }
849
850 method_group = Expression.MemberLookup (
851 ec, type, "Invoke", MemberTypes.Method,
852 Expression.AllBindingFlags, loc) as MethodGroupExpr;
853
854 if (method_group == null) {
855 Report.Error (-200, loc, "Internal error ! Could not find Invoke method!");
856 return null;
857 }
858
859 // This is what MS' compiler reports. We could always choose
860 // to be more verbose and actually give delegate-level specifics
861 if (!Delegate.VerifyDelegate (ec, type, e_type, loc)) {
862 Report.Error (29, loc, "Cannot implicitly convert type '" + e_type + "' " +
863 "to type '" + type + "'");
864 return null;
865 }
866
867 delegate_instance_expression = e;
868 delegate_method = method_group.Methods [0];
869
870 eclass = ExprClass.Value;
871 return this;
872 }
873 }
874
875 public class DelegateInvocation : ExpressionStatement {
876
877 public Expression InstanceExpr;
878 public ArrayList Arguments;
879
880 MethodBase method;
881
882 public DelegateInvocation (Expression instance_expr, ArrayList args, Location loc)
883 {
884 this.InstanceExpr = instance_expr;
885 this.Arguments = args;
886 this.loc = loc;
887 }
888
889 public override Expression DoResolve (EmitContext ec)
890 {
891 if (InstanceExpr is EventExpr) {
892
893 EventInfo ei = ((EventExpr) InstanceExpr).EventInfo;
894
895 Expression ml = MemberLookup (
896 ec, ec.ContainerType, ei.Name,
897 MemberTypes.Event, AllBindingFlags | BindingFlags.DeclaredOnly, loc);
898
899 if (ml == null) {
900 //
901 // If this is the case, then the Event does not belong
902 // to this Type and so, according to the spec
903 // cannot be accessed directly
904 //
905 // Note that target will not appear as an EventExpr
906 // in the case it is being referenced within the same type container;
907 // it will appear as a FieldExpr in that case.
908 //
909
910 Assign.error70 (ei, loc);
911 return null;
912 }
913 }
914
915
916 Type del_type = InstanceExpr.Type;
917 if (del_type == null)
918 return null;
919
920 if (Arguments != null){
921 foreach (Argument a in Arguments){
922 if (!a.Resolve (ec, loc))
923 return null;
924 }
925 }
926
927 if (!Delegate.VerifyApplicability (ec, del_type, Arguments, loc))
928 return null;
929
930 Expression lookup = Expression.MemberLookup (ec, del_type, "Invoke", loc);
931 if (!(lookup is MethodGroupExpr)) {
932 Report.Error (-100, loc, "Internal error: could not find Invoke method!");
933 return null;
934 }
935
936 method = ((MethodGroupExpr) lookup).Methods [0];
937 type = ((MethodInfo) method).ReturnType;
938 eclass = ExprClass.Value;
939
940 return this;
941 }
942
943 public override void Emit (EmitContext ec)
944 {
945 //
946 // Invocation on delegates call the virtual Invoke member
947 // so we are always `instance' calls
948 //
949 Invocation.EmitCall (ec, false, false, InstanceExpr, method, Arguments, loc);
950 }
951
952 public override void EmitStatement (EmitContext ec)
953 {
954 Emit (ec);
955 //
956 // Pop the return value if there is one
957 //
958 if (method is MethodInfo){
959 if (((MethodInfo) method).ReturnType != TypeManager.void_type)
960 ec.ig.Emit (OpCodes.Pop);
961 }
962 }
963
964 }
965 }
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