2 // delegate.cs: Delegate Handler
5 // Ravi Pratap (ravi@ximian.com)
6 // Miguel de Icaza (miguel@ximian.com)
7 // Marek Safar (marek.safar@gmail.com)
9 // Dual licensed under the terms of the MIT X11 or GNU GPL
11 // Copyright 2001 Ximian, Inc (http://www.ximian.com)
12 // Copyright 2003-2009 Novell, Inc (http://www.novell.com)
13 // Copyright 2011 Xamarin Inc
19 using IKVM.Reflection;
20 using IKVM.Reflection.Emit;
22 using System.Reflection;
23 using System.Reflection.Emit;
26 namespace Mono.CSharp {
29 // Delegate container implementation
31 public class Delegate : TypeDefinition, IParametersMember
33 FullNamedExpression ReturnType;
34 readonly ParametersCompiled parameters;
36 Constructor Constructor;
38 Method BeginInvokeBuilder;
39 Method EndInvokeBuilder;
41 static readonly string[] attribute_targets = new string [] { "type", "return" };
43 public static readonly string InvokeMethodName = "Invoke";
45 Expression instance_expr;
46 ReturnParameter return_attributes;
48 const Modifiers MethodModifiers = Modifiers.PUBLIC | Modifiers.VIRTUAL;
50 const Modifiers AllowedModifiers =
58 public Delegate (TypeContainer parent, FullNamedExpression type, Modifiers mod_flags, MemberName name, ParametersCompiled param_list,
60 : base (parent, name, attrs, MemberKind.Delegate)
63 this.ReturnType = type;
64 ModFlags = ModifiersExtensions.Check (AllowedModifiers, mod_flags,
65 IsTopLevel ? Modifiers.INTERNAL :
66 Modifiers.PRIVATE, name.Location, Report);
67 parameters = param_list;
68 spec = new TypeSpec (Kind, null, this, null, ModFlags | Modifiers.SEALED);
72 public TypeSpec MemberType {
74 return ReturnType.Type;
78 public AParametersCollection Parameters {
84 public FullNamedExpression TypExpression {
92 public override void Accept (StructuralVisitor visitor)
97 public override void ApplyAttributeBuilder (Attribute a, MethodSpec ctor, byte[] cdata, PredefinedAttributes pa)
99 if (a.Target == AttributeTargets.ReturnValue) {
100 if (return_attributes == null)
101 return_attributes = new ReturnParameter (this, InvokeBuilder.MethodBuilder, Location);
103 return_attributes.ApplyAttributeBuilder (a, ctor, cdata, pa);
107 base.ApplyAttributeBuilder (a, ctor, cdata, pa);
110 public override AttributeTargets AttributeTargets {
112 return AttributeTargets.Delegate;
116 protected override bool DoDefineMembers ()
118 var builtin_types = Compiler.BuiltinTypes;
120 var ctor_parameters = ParametersCompiled.CreateFullyResolved (
122 new Parameter (new TypeExpression (builtin_types.Object, Location), "object", Parameter.Modifier.NONE, null, Location),
123 new Parameter (new TypeExpression (builtin_types.IntPtr, Location), "method", Parameter.Modifier.NONE, null, Location)
126 builtin_types.Object,
131 Constructor = new Constructor (this, Constructor.ConstructorName,
132 Modifiers.PUBLIC, null, ctor_parameters, Location);
133 Constructor.Define ();
136 // Here the various methods like Invoke, BeginInvoke etc are defined
138 // First, call the `out of band' special method for
139 // defining recursively any types we need:
143 if (!p.Resolve (this))
150 // Check accessibility
151 foreach (var partype in p.Types) {
152 if (!IsAccessibleAs (partype)) {
153 Report.SymbolRelatedToPreviousError (partype);
154 Report.Error (59, Location,
155 "Inconsistent accessibility: parameter type `{0}' is less accessible than delegate `{1}'",
156 partype.GetSignatureForError (), GetSignatureForError ());
160 var ret_type = ReturnType.ResolveAsType (this);
161 if (ret_type == null)
165 // We don't have to check any others because they are all
166 // guaranteed to be accessible - they are standard types.
168 if (!IsAccessibleAs (ret_type)) {
169 Report.SymbolRelatedToPreviousError (ret_type);
170 Report.Error (58, Location,
171 "Inconsistent accessibility: return type `" +
172 ret_type.GetSignatureForError () + "' is less " +
173 "accessible than delegate `" + GetSignatureForError () + "'");
177 CheckProtectedModifier ();
179 if (Compiler.Settings.StdLib && ret_type.IsSpecialRuntimeType) {
180 Method.Error1599 (Location, ret_type, Report);
184 VarianceDecl.CheckTypeVariance (ret_type, Variance.Covariant, this);
186 var resolved_rt = new TypeExpression (ret_type, Location);
187 InvokeBuilder = new Method (this, resolved_rt, MethodModifiers, new MemberName (InvokeMethodName), p, null);
188 InvokeBuilder.Define ();
191 // Don't emit async method for compiler generated delegates (e.g. dynamic site containers)
193 if (!IsCompilerGenerated) {
194 DefineAsyncMethods (resolved_rt);
200 void DefineAsyncMethods (TypeExpression returnType)
202 var iasync_result = Module.PredefinedTypes.IAsyncResult;
203 var async_callback = Module.PredefinedTypes.AsyncCallback;
206 // It's ok when async types don't exist, the delegate will have Invoke method only
208 if (!iasync_result.Define () || !async_callback.Define ())
214 ParametersCompiled async_parameters;
215 if (Parameters.Count == 0) {
216 async_parameters = ParametersCompiled.EmptyReadOnlyParameters;
218 var compiled = new Parameter[Parameters.Count];
219 for (int i = 0; i < compiled.Length; ++i) {
220 var p = parameters[i];
221 compiled[i] = new Parameter (new TypeExpression (parameters.Types[i], Location),
223 p.ModFlags & Parameter.Modifier.RefOutMask,
224 p.OptAttributes == null ? null : p.OptAttributes.Clone (), Location);
227 async_parameters = new ParametersCompiled (compiled);
230 async_parameters = ParametersCompiled.MergeGenerated (Compiler, async_parameters, false,
232 new Parameter (new TypeExpression (async_callback.TypeSpec, Location), "callback", Parameter.Modifier.NONE, null, Location),
233 new Parameter (new TypeExpression (Compiler.BuiltinTypes.Object, Location), "object", Parameter.Modifier.NONE, null, Location)
236 async_callback.TypeSpec,
237 Compiler.BuiltinTypes.Object
241 BeginInvokeBuilder = new Method (this,
242 new TypeExpression (iasync_result.TypeSpec, Location), MethodModifiers,
243 new MemberName ("BeginInvoke"), async_parameters, null);
244 BeginInvokeBuilder.Define ();
247 // EndInvoke is a bit more interesting, all the parameters labeled as
248 // out or ref have to be duplicated here.
252 // Define parameters, and count out/ref parameters
254 ParametersCompiled end_parameters;
257 foreach (Parameter p in Parameters.FixedParameters) {
258 if ((p.ModFlags & Parameter.Modifier.RefOutMask) != 0)
262 if (out_params > 0) {
263 Parameter[] end_params = new Parameter[out_params];
266 for (int i = 0; i < Parameters.FixedParameters.Length; ++i) {
267 Parameter p = parameters [i];
268 if ((p.ModFlags & Parameter.Modifier.RefOutMask) == 0)
271 end_params [param++] = new Parameter (new TypeExpression (p.Type, Location),
273 p.ModFlags & Parameter.Modifier.RefOutMask,
274 p.OptAttributes == null ? null : p.OptAttributes.Clone (), Location);
277 end_parameters = new ParametersCompiled (end_params);
279 end_parameters = ParametersCompiled.EmptyReadOnlyParameters;
282 end_parameters = ParametersCompiled.MergeGenerated (Compiler, end_parameters, false,
284 new TypeExpression (iasync_result.TypeSpec, Location),
285 "result", Parameter.Modifier.NONE, null, Location),
286 iasync_result.TypeSpec);
289 // Create method, define parameters, register parameters with type system
291 EndInvokeBuilder = new Method (this, returnType, MethodModifiers, new MemberName ("EndInvoke"), end_parameters, null);
292 EndInvokeBuilder.Define ();
295 public override void PrepareEmit ()
297 if ((caching_flags & Flags.CloseTypeCreated) != 0)
300 if (!Parameters.IsEmpty) {
301 parameters.ResolveDefaultValues (this);
304 InvokeBuilder.PrepareEmit ();
305 if (BeginInvokeBuilder != null) {
306 BeginInvokeBuilder.PrepareEmit ();
307 EndInvokeBuilder.PrepareEmit ();
311 public override void Emit ()
315 if (ReturnType.Type != null) {
316 if (ReturnType.Type.BuiltinType == BuiltinTypeSpec.Type.Dynamic) {
317 return_attributes = new ReturnParameter (this, InvokeBuilder.MethodBuilder, Location);
318 Module.PredefinedAttributes.Dynamic.EmitAttribute (return_attributes.Builder);
319 } else if (ReturnType.Type.HasDynamicElement) {
320 return_attributes = new ReturnParameter (this, InvokeBuilder.MethodBuilder, Location);
321 Module.PredefinedAttributes.Dynamic.EmitAttribute (return_attributes.Builder, ReturnType.Type, Location);
324 ConstraintChecker.Check (this, ReturnType.Type, ReturnType.Location);
327 Constructor.ParameterInfo.ApplyAttributes (this, Constructor.ConstructorBuilder);
328 Constructor.ConstructorBuilder.SetImplementationFlags (MethodImplAttributes.Runtime);
330 parameters.CheckConstraints (this);
331 parameters.ApplyAttributes (this, InvokeBuilder.MethodBuilder);
332 InvokeBuilder.MethodBuilder.SetImplementationFlags (MethodImplAttributes.Runtime);
334 if (BeginInvokeBuilder != null) {
335 BeginInvokeBuilder.ParameterInfo.ApplyAttributes (this, BeginInvokeBuilder.MethodBuilder);
336 EndInvokeBuilder.ParameterInfo.ApplyAttributes (this, EndInvokeBuilder.MethodBuilder);
338 BeginInvokeBuilder.MethodBuilder.SetImplementationFlags (MethodImplAttributes.Runtime);
339 EndInvokeBuilder.MethodBuilder.SetImplementationFlags (MethodImplAttributes.Runtime);
343 protected override TypeSpec[] ResolveBaseTypes (out FullNamedExpression base_class)
345 base_type = Compiler.BuiltinTypes.MulticastDelegate;
350 protected override TypeAttributes TypeAttr {
352 return base.TypeAttr | TypeAttributes.Class | TypeAttributes.Sealed;
356 public override string[] ValidAttributeTargets {
358 return attribute_targets;
363 protected override bool VerifyClsCompliance ()
365 if (!base.VerifyClsCompliance ()) {
369 parameters.VerifyClsCompliance (this);
371 if (!InvokeBuilder.MemberType.IsCLSCompliant ()) {
372 Report.Warning (3002, 1, Location, "Return type of `{0}' is not CLS-compliant",
373 GetSignatureForError ());
379 public static MethodSpec GetConstructor (TypeSpec delType)
381 var ctor = MemberCache.FindMember (delType, MemberFilter.Constructor (null), BindingRestriction.DeclaredOnly);
382 return (MethodSpec) ctor;
386 // Returns the "Invoke" from a delegate type
388 public static MethodSpec GetInvokeMethod (TypeSpec delType)
390 var invoke = MemberCache.FindMember (delType,
391 MemberFilter.Method (InvokeMethodName, 0, null, null),
392 BindingRestriction.DeclaredOnly);
394 return (MethodSpec) invoke;
397 public static AParametersCollection GetParameters (TypeSpec delType)
399 var invoke_mb = GetInvokeMethod (delType);
400 return invoke_mb.Parameters;
404 // 15.2 Delegate compatibility
406 public static bool IsTypeCovariant (ResolveContext rc, TypeSpec a, TypeSpec b)
409 // For each value parameter (a parameter with no ref or out modifier), an
410 // identity conversion or implicit reference conversion exists from the
411 // parameter type in D to the corresponding parameter type in M
416 if (rc.Module.Compiler.Settings.Version == LanguageVersion.ISO_1)
419 if (a.IsGenericParameter && b.IsGenericParameter)
422 return Convert.ImplicitReferenceConversionExists (a, b);
425 public static string FullDelegateDesc (MethodSpec invoke_method)
427 return TypeManager.GetFullNameSignature (invoke_method).Replace (".Invoke", "");
430 public Expression InstanceExpression {
432 return instance_expr;
435 instance_expr = value;
441 // Base class for `NewDelegate' and `ImplicitDelegateCreation'
443 public abstract class DelegateCreation : Expression, OverloadResolver.IErrorHandler
445 bool conditional_access_receiver;
446 protected MethodSpec constructor_method;
447 protected MethodGroupExpr method_group;
449 public bool AllowSpecialMethodsInvocation { get; set; }
451 public override bool ContainsEmitWithAwait ()
453 var instance = method_group.InstanceExpression;
454 return instance != null && instance.ContainsEmitWithAwait ();
457 public static Arguments CreateDelegateMethodArguments (ResolveContext rc, AParametersCollection pd, TypeSpec[] types, Location loc)
459 Arguments delegate_arguments = new Arguments (pd.Count);
460 for (int i = 0; i < pd.Count; ++i) {
461 Argument.AType atype_modifier;
462 switch (pd.FixedParameters [i].ModFlags & Parameter.Modifier.RefOutMask) {
463 case Parameter.Modifier.REF:
464 atype_modifier = Argument.AType.Ref;
466 case Parameter.Modifier.OUT:
467 atype_modifier = Argument.AType.Out;
474 var ptype = types[i];
475 if (ptype.BuiltinType == BuiltinTypeSpec.Type.Dynamic)
476 ptype = rc.BuiltinTypes.Object;
478 delegate_arguments.Add (new Argument (new TypeExpression (ptype, loc), atype_modifier));
481 return delegate_arguments;
484 public override Expression CreateExpressionTree (ResolveContext ec)
486 MemberAccess ma = new MemberAccess (new MemberAccess (new QualifiedAliasMember ("global", "System", loc), "Delegate", loc), "CreateDelegate", loc);
488 Arguments args = new Arguments (3);
489 args.Add (new Argument (new TypeOf (type, loc)));
491 if (method_group.InstanceExpression == null)
492 args.Add (new Argument (new NullLiteral (loc)));
494 args.Add (new Argument (method_group.InstanceExpression));
496 args.Add (new Argument (method_group.CreateExpressionTree (ec)));
497 Expression e = new Invocation (ma, args).Resolve (ec);
501 e = Convert.ExplicitConversion (ec, e, type, loc);
505 return e.CreateExpressionTree (ec);
508 protected override Expression DoResolve (ResolveContext ec)
510 constructor_method = Delegate.GetConstructor (type);
512 var invoke_method = Delegate.GetInvokeMethod (type);
514 if (!ec.HasSet (ResolveContext.Options.ConditionalAccessReceiver)) {
515 if (method_group.HasConditionalAccess ()) {
516 conditional_access_receiver = true;
517 ec.Set (ResolveContext.Options.ConditionalAccessReceiver);
521 Arguments arguments = CreateDelegateMethodArguments (ec, invoke_method.Parameters, invoke_method.Parameters.Types, loc);
522 method_group = method_group.OverloadResolve (ec, ref arguments, this, OverloadResolver.Restrictions.CovariantDelegate);
524 if (conditional_access_receiver)
525 ec.With (ResolveContext.Options.ConditionalAccessReceiver, false);
527 if (method_group == null)
530 var delegate_method = method_group.BestCandidate;
532 if (delegate_method.DeclaringType.IsNullableType) {
533 ec.Report.Error (1728, loc, "Cannot create delegate from method `{0}' because it is a member of System.Nullable<T> type",
534 delegate_method.GetSignatureForError ());
538 if (!AllowSpecialMethodsInvocation)
539 Invocation.IsSpecialMethodInvocation (ec, delegate_method, loc);
541 ExtensionMethodGroupExpr emg = method_group as ExtensionMethodGroupExpr;
543 method_group.InstanceExpression = emg.ExtensionExpression;
544 TypeSpec e_type = emg.ExtensionExpression.Type;
545 if (TypeSpec.IsValueType (e_type)) {
546 ec.Report.Error (1113, loc, "Extension method `{0}' of value type `{1}' cannot be used to create delegates",
547 delegate_method.GetSignatureForError (), e_type.GetSignatureForError ());
551 TypeSpec rt = method_group.BestCandidateReturnType;
552 if (rt.BuiltinType == BuiltinTypeSpec.Type.Dynamic)
553 rt = ec.BuiltinTypes.Object;
555 if (!Delegate.IsTypeCovariant (ec, rt, invoke_method.ReturnType)) {
556 Expression ret_expr = new TypeExpression (delegate_method.ReturnType, loc);
557 Error_ConversionFailed (ec, delegate_method, ret_expr);
560 if (method_group.IsConditionallyExcluded) {
561 ec.Report.SymbolRelatedToPreviousError (delegate_method);
562 MethodOrOperator m = delegate_method.MemberDefinition as MethodOrOperator;
563 if (m != null && m.IsPartialDefinition) {
564 ec.Report.Error (762, loc, "Cannot create delegate from partial method declaration `{0}'",
565 delegate_method.GetSignatureForError ());
567 ec.Report.Error (1618, loc, "Cannot create delegate with `{0}' because it has a Conditional attribute",
568 TypeManager.CSharpSignature (delegate_method));
572 var expr = method_group.InstanceExpression;
573 if (expr != null && (expr.Type.IsGenericParameter || !TypeSpec.IsReferenceType (expr.Type)))
574 method_group.InstanceExpression = new BoxedCast (expr, ec.BuiltinTypes.Object);
576 eclass = ExprClass.Value;
580 public override void Emit (EmitContext ec)
582 if (conditional_access_receiver)
583 ec.ConditionalAccess = new ConditionalAccessContext (type, ec.DefineLabel ());
585 if (method_group.InstanceExpression == null) {
588 var ie = new InstanceEmitter (method_group.InstanceExpression, false);
589 ie.Emit (ec, method_group.ConditionalAccess);
592 var delegate_method = method_group.BestCandidate;
594 // Any delegate must be sealed
595 if (!delegate_method.DeclaringType.IsDelegate && delegate_method.IsVirtual && !method_group.IsBase) {
596 ec.Emit (OpCodes.Dup);
597 ec.Emit (OpCodes.Ldvirtftn, delegate_method);
599 ec.Emit (OpCodes.Ldftn, delegate_method);
602 ec.Emit (OpCodes.Newobj, constructor_method);
604 if (conditional_access_receiver)
605 ec.CloseConditionalAccess (null);
608 public override void FlowAnalysis (FlowAnalysisContext fc)
610 base.FlowAnalysis (fc);
611 method_group.FlowAnalysis (fc);
613 if (conditional_access_receiver)
614 fc.ConditionalAccessEnd ();
617 void Error_ConversionFailed (ResolveContext ec, MethodSpec method, Expression return_type)
619 var invoke_method = Delegate.GetInvokeMethod (type);
620 string member_name = method_group.InstanceExpression != null ?
621 Delegate.FullDelegateDesc (method) :
622 TypeManager.GetFullNameSignature (method);
624 ec.Report.SymbolRelatedToPreviousError (type);
625 ec.Report.SymbolRelatedToPreviousError (method);
626 if (ec.Module.Compiler.Settings.Version == LanguageVersion.ISO_1) {
627 ec.Report.Error (410, loc, "A method or delegate `{0} {1}' parameters and return type must be same as delegate `{2} {3}' parameters and return type",
628 method.ReturnType.GetSignatureForError (), member_name,
629 invoke_method.ReturnType.GetSignatureForError (), Delegate.FullDelegateDesc (invoke_method));
633 if (return_type == null) {
634 ec.Report.Error (123, loc, "A method or delegate `{0}' parameters do not match delegate `{1}' parameters",
635 member_name, Delegate.FullDelegateDesc (invoke_method));
639 ec.Report.Error (407, loc, "A method or delegate `{0} {1}' return type does not match delegate `{2} {3}' return type",
640 return_type.GetSignatureForError (), member_name,
641 invoke_method.ReturnType.GetSignatureForError (), Delegate.FullDelegateDesc (invoke_method));
644 public static bool ImplicitStandardConversionExists (ResolveContext ec, MethodGroupExpr mg, TypeSpec target_type)
646 // if (target_type == TypeManager.delegate_type || target_type == TypeManager.multicast_delegate_type)
649 var invoke = Delegate.GetInvokeMethod (target_type);
651 Arguments arguments = CreateDelegateMethodArguments (ec, invoke.Parameters, invoke.Parameters.Types, mg.Location);
652 mg = mg.OverloadResolve (ec, ref arguments, null, OverloadResolver.Restrictions.CovariantDelegate | OverloadResolver.Restrictions.ProbingOnly);
653 return mg != null && Delegate.IsTypeCovariant (ec, mg.BestCandidateReturnType, invoke.ReturnType);
656 #region IErrorHandler Members
658 bool OverloadResolver.IErrorHandler.AmbiguousCandidates (ResolveContext ec, MemberSpec best, MemberSpec ambiguous)
663 bool OverloadResolver.IErrorHandler.ArgumentMismatch (ResolveContext rc, MemberSpec best, Argument arg, int index)
665 Error_ConversionFailed (rc, best as MethodSpec, null);
669 bool OverloadResolver.IErrorHandler.NoArgumentMatch (ResolveContext rc, MemberSpec best)
671 Error_ConversionFailed (rc, best as MethodSpec, null);
675 bool OverloadResolver.IErrorHandler.TypeInferenceFailed (ResolveContext rc, MemberSpec best)
684 // Created from the conversion code
686 public class ImplicitDelegateCreation : DelegateCreation
690 public ImplicitDelegateCreation (TypeSpec delegateType, MethodGroupExpr mg, Location loc)
693 this.method_group = mg;
698 // Returns true when type is MVAR or has MVAR reference
700 public static bool ContainsMethodTypeParameter (TypeSpec type)
702 var tps = type as TypeParameterSpec;
704 return tps.IsMethodOwned;
706 var ec = type as ElementTypeSpec;
708 return ContainsMethodTypeParameter (ec.Element);
710 foreach (var t in type.TypeArguments) {
711 if (ContainsMethodTypeParameter (t)) {
717 return ContainsMethodTypeParameter (type.DeclaringType);
724 if (ContainsMethodTypeParameter (type))
727 var best = method_group.BestCandidate;
728 if (ContainsMethodTypeParameter (best.DeclaringType))
731 if (best.TypeArguments != null) {
732 foreach (var ta in best.TypeArguments) {
733 if (ContainsMethodTypeParameter (ta))
741 protected override Expression DoResolve (ResolveContext ec)
743 var expr = base.DoResolve (ec);
745 return ErrorExpression.Instance;
747 if (ec.IsInProbingMode)
751 // Cache any static delegate creation
753 if (method_group.InstanceExpression != null)
757 // Cannot easily cache types with MVAR
763 // Create type level cache for a delegate instance
765 var parent = ec.CurrentMemberDefinition.Parent.PartialContainer;
766 int id = parent.MethodGroupsCounter++;
768 mg_cache = new Field (parent, new TypeExpression (type, loc),
769 Modifiers.STATIC | Modifiers.PRIVATE | Modifiers.COMPILER_GENERATED,
770 new MemberName (CompilerGeneratedContainer.MakeName (null, "f", "mg$cache", id), loc), null);
772 parent.AddField (mg_cache);
777 public override void Emit (EmitContext ec)
779 Label l_initialized = ec.DefineLabel ();
781 if (mg_cache != null) {
782 ec.Emit (OpCodes.Ldsfld, mg_cache.Spec);
783 ec.Emit (OpCodes.Brtrue_S, l_initialized);
788 if (mg_cache != null) {
789 ec.Emit (OpCodes.Stsfld, mg_cache.Spec);
790 ec.MarkLabel (l_initialized);
791 ec.Emit (OpCodes.Ldsfld, mg_cache.Spec);
797 // A delegate-creation-expression, invoked from the `New' class
799 public class NewDelegate : DelegateCreation
801 public Arguments Arguments;
804 // This constructor is invoked from the `New' expression
806 public NewDelegate (TypeSpec type, Arguments Arguments, Location loc)
809 this.Arguments = Arguments;
813 protected override Expression DoResolve (ResolveContext ec)
815 if (Arguments == null || Arguments.Count != 1) {
816 ec.Report.Error (149, loc, "Method name expected");
820 Argument a = Arguments [0];
821 if (!a.ResolveMethodGroup (ec))
824 Expression e = a.Expr;
826 AnonymousMethodExpression ame = e as AnonymousMethodExpression;
827 if (ame != null && ec.Module.Compiler.Settings.Version != LanguageVersion.ISO_1) {
828 e = ame.Compatible (ec, type);
832 return e.Resolve (ec);
835 method_group = e as MethodGroupExpr;
836 if (method_group == null) {
837 if (e.Type.BuiltinType == BuiltinTypeSpec.Type.Dynamic) {
838 e = Convert.ImplicitConversionRequired (ec, e, type, loc);
839 } else if (!e.Type.IsDelegate) {
840 e.Error_UnexpectedKind (ec, ResolveFlags.MethodGroup | ResolveFlags.Type, loc);
845 // An argument is not a method but another delegate
847 method_group = new MethodGroupExpr (Delegate.GetInvokeMethod (e.Type), e.Type, loc);
848 method_group.InstanceExpression = e;
851 return base.DoResolve (ec);
856 // Invocation converted to delegate Invoke call
858 class DelegateInvocation : ExpressionStatement
860 readonly Expression InstanceExpr;
861 readonly bool conditionalAccessReceiver;
865 public DelegateInvocation (Expression instance_expr, Arguments args, bool conditionalAccessReceiver, Location loc)
867 this.InstanceExpr = instance_expr;
868 this.arguments = args;
869 this.conditionalAccessReceiver = conditionalAccessReceiver;
873 public override bool ContainsEmitWithAwait ()
875 return InstanceExpr.ContainsEmitWithAwait () || (arguments != null && arguments.ContainsEmitWithAwait ());
878 public override Expression CreateExpressionTree (ResolveContext ec)
880 Arguments args = Arguments.CreateForExpressionTree (ec, this.arguments,
881 InstanceExpr.CreateExpressionTree (ec));
883 return CreateExpressionFactoryCall (ec, "Invoke", args);
886 public override void FlowAnalysis (FlowAnalysisContext fc)
888 InstanceExpr.FlowAnalysis (fc);
889 if (arguments != null)
890 arguments.FlowAnalysis (fc);
893 protected override Expression DoResolve (ResolveContext ec)
895 TypeSpec del_type = InstanceExpr.Type;
896 if (del_type == null)
900 // Do only core overload resolution the rest of the checks has been
901 // done on primary expression
903 method = Delegate.GetInvokeMethod (del_type);
904 var res = new OverloadResolver (new MemberSpec[] { method }, OverloadResolver.Restrictions.DelegateInvoke, loc);
905 var valid = res.ResolveMember<MethodSpec> (ec, ref arguments);
906 if (valid == null && !res.BestCandidateIsDynamic)
909 type = method.ReturnType;
910 if (conditionalAccessReceiver)
911 type = LiftMemberType (ec, type);
913 eclass = ExprClass.Value;
917 public override void Emit (EmitContext ec)
919 if (conditionalAccessReceiver) {
920 ec.ConditionalAccess = new ConditionalAccessContext (type, ec.DefineLabel ());
924 // Invocation on delegates call the virtual Invoke member
925 // so we are always `instance' calls
927 var call = new CallEmitter ();
928 call.InstanceExpression = InstanceExpr;
929 call.Emit (ec, method, arguments, loc);
931 if (conditionalAccessReceiver)
932 ec.CloseConditionalAccess (type.IsNullableType && type != method.ReturnType ? type : null);
935 public override void EmitStatement (EmitContext ec)
937 if (conditionalAccessReceiver) {
938 ec.ConditionalAccess = new ConditionalAccessContext (type, ec.DefineLabel ()) {
943 var call = new CallEmitter ();
944 call.InstanceExpression = InstanceExpr;
945 call.EmitStatement (ec, method, arguments, loc);
947 if (conditionalAccessReceiver)
948 ec.CloseConditionalAccess (null);
951 public override System.Linq.Expressions.Expression MakeExpression (BuilderContext ctx)
953 return Invocation.MakeExpression (ctx, InstanceExpr, method, arguments);