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)
18 using IKVM.Reflection;
19 using IKVM.Reflection.Emit;
21 using System.Reflection;
22 using System.Reflection.Emit;
25 namespace Mono.CSharp {
28 // Delegate container implementation
30 public class Delegate : TypeContainer, IParametersMember
32 FullNamedExpression ReturnType;
33 readonly ParametersCompiled parameters;
35 Constructor Constructor;
37 Method BeginInvokeBuilder;
38 Method EndInvokeBuilder;
40 static readonly string[] attribute_targets = new string [] { "type", "return" };
42 public static readonly string InvokeMethodName = "Invoke";
44 Expression instance_expr;
45 ReturnParameter return_attributes;
47 const Modifiers MethodModifiers = Modifiers.PUBLIC | Modifiers.VIRTUAL;
49 const Modifiers AllowedModifiers =
57 public Delegate (NamespaceEntry ns, DeclSpace parent, FullNamedExpression type,
58 Modifiers mod_flags, MemberName name, ParametersCompiled param_list,
60 : base (ns, 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 {
85 public override void Accept (StructuralVisitor visitor)
90 public override void ApplyAttributeBuilder (Attribute a, MethodSpec ctor, byte[] cdata, PredefinedAttributes pa)
92 if (a.Target == AttributeTargets.ReturnValue) {
93 if (return_attributes == null)
94 return_attributes = new ReturnParameter (this, InvokeBuilder.MethodBuilder, Location);
96 return_attributes.ApplyAttributeBuilder (a, ctor, cdata, pa);
100 base.ApplyAttributeBuilder (a, ctor, cdata, pa);
103 public override AttributeTargets AttributeTargets {
105 return AttributeTargets.Delegate;
109 protected override bool DoDefineMembers ()
111 var buildin_types = Compiler.BuildinTypes;
113 var ctor_parameters = ParametersCompiled.CreateFullyResolved (
115 new Parameter (new TypeExpression (buildin_types.Object, Location), "object", Parameter.Modifier.NONE, null, Location),
116 new Parameter (new TypeExpression (buildin_types.IntPtr, Location), "method", Parameter.Modifier.NONE, null, Location)
119 buildin_types.Object,
124 Constructor = new Constructor (this, Constructor.ConstructorName,
125 Modifiers.PUBLIC, null, ctor_parameters, null, Location);
126 Constructor.Define ();
129 // Here the various methods like Invoke, BeginInvoke etc are defined
131 // First, call the `out of band' special method for
132 // defining recursively any types we need:
136 if (!p.Resolve (this))
143 // Check accessibility
144 foreach (var partype in p.Types) {
145 if (!IsAccessibleAs (partype)) {
146 Report.SymbolRelatedToPreviousError (partype);
147 Report.Error (59, Location,
148 "Inconsistent accessibility: parameter type `{0}' is less accessible than delegate `{1}'",
149 TypeManager.CSharpName (partype), GetSignatureForError ());
153 ReturnType = ReturnType.ResolveAsTypeTerminal (this, false);
154 if (ReturnType == null)
157 var ret_type = ReturnType.Type;
160 // We don't have to check any others because they are all
161 // guaranteed to be accessible - they are standard types.
163 if (!IsAccessibleAs (ret_type)) {
164 Report.SymbolRelatedToPreviousError (ret_type);
165 Report.Error (58, Location,
166 "Inconsistent accessibility: return type `" +
167 TypeManager.CSharpName (ret_type) + "' is less " +
168 "accessible than delegate `" + GetSignatureForError () + "'");
172 CheckProtectedModifier ();
174 if (Compiler.Settings.StdLib && ret_type.IsSpecialRuntimeType) {
175 Method.Error1599 (Location, ret_type, Report);
179 TypeManager.CheckTypeVariance (ret_type, Variance.Covariant, this);
181 InvokeBuilder = new Method (this, null, ReturnType, MethodModifiers, new MemberName (InvokeMethodName), p, null);
182 InvokeBuilder.Define ();
185 // Don't emit async method for compiler generated delegates (e.g. dynamic site containers)
187 if (!IsCompilerGenerated) {
188 DefineAsyncMethods (Parameters.CallingConvention);
194 void DefineAsyncMethods (CallingConventions cc)
196 var iasync_result = Module.PredefinedTypes.IAsyncResult;
197 var async_callback = Module.PredefinedTypes.AsyncCallback;
200 // It's ok when async types don't exist, the delegate will have Invoke method only
202 if (!iasync_result.Define () || !async_callback.Define ())
208 ParametersCompiled async_parameters;
209 if (Parameters.Count == 0) {
210 async_parameters = ParametersCompiled.EmptyReadOnlyParameters;
212 var compiled = new Parameter[Parameters.Count];
213 for (int i = 0; i < compiled.Length; ++i) {
214 var p = parameters[i];
215 compiled[i] = new Parameter (new TypeExpression (parameters.Types[i], Location),
217 p.ModFlags & (Parameter.Modifier.REF | Parameter.Modifier.OUT),
218 p.OptAttributes == null ? null : p.OptAttributes.Clone (), Location);
221 async_parameters = new ParametersCompiled (compiled);
224 async_parameters = ParametersCompiled.MergeGenerated (Compiler, async_parameters, false,
226 new Parameter (new TypeExpression (async_callback.TypeSpec, Location), "callback", Parameter.Modifier.NONE, null, Location),
227 new Parameter (new TypeExpression (Compiler.BuildinTypes.Object, Location), "object", Parameter.Modifier.NONE, null, Location)
230 async_callback.TypeSpec,
231 Compiler.BuildinTypes.Object
235 BeginInvokeBuilder = new Method (this, null,
236 new TypeExpression (iasync_result.TypeSpec, Location), MethodModifiers,
237 new MemberName ("BeginInvoke"), async_parameters, null);
238 BeginInvokeBuilder.Define ();
241 // EndInvoke is a bit more interesting, all the parameters labeled as
242 // out or ref have to be duplicated here.
246 // Define parameters, and count out/ref parameters
248 ParametersCompiled end_parameters;
251 foreach (Parameter p in Parameters.FixedParameters) {
252 if ((p.ModFlags & Parameter.Modifier.ISBYREF) != 0)
256 if (out_params > 0) {
257 Parameter[] end_params = new Parameter[out_params];
260 for (int i = 0; i < Parameters.FixedParameters.Length; ++i) {
261 Parameter p = parameters [i];
262 if ((p.ModFlags & Parameter.Modifier.ISBYREF) == 0)
265 end_params [param++] = new Parameter (new TypeExpression (p.Type, Location),
267 p.ModFlags & (Parameter.Modifier.REF | Parameter.Modifier.OUT),
268 p.OptAttributes == null ? null : p.OptAttributes.Clone (), Location);
271 end_parameters = new ParametersCompiled (end_params);
273 end_parameters = ParametersCompiled.EmptyReadOnlyParameters;
276 end_parameters = ParametersCompiled.MergeGenerated (Compiler, end_parameters, false,
278 new TypeExpression (iasync_result.TypeSpec, Location),
279 "result", Parameter.Modifier.NONE, null, Location),
280 iasync_result.TypeSpec);
283 // Create method, define parameters, register parameters with type system
285 EndInvokeBuilder = new Method (this, null, ReturnType, MethodModifiers, new MemberName ("EndInvoke"), end_parameters, null);
286 EndInvokeBuilder.Define ();
289 public override void DefineConstants ()
291 if (!Parameters.IsEmpty) {
292 parameters.ResolveDefaultValues (this);
296 public override void EmitType ()
298 if (ReturnType.Type != null) {
299 if (ReturnType.Type.BuildinType == BuildinTypeSpec.Type.Dynamic) {
300 return_attributes = new ReturnParameter (this, InvokeBuilder.MethodBuilder, Location);
301 Module.PredefinedAttributes.Dynamic.EmitAttribute (return_attributes.Builder);
302 } else if (ReturnType.Type.HasDynamicElement) {
303 return_attributes = new ReturnParameter (this, InvokeBuilder.MethodBuilder, Location);
304 Module.PredefinedAttributes.Dynamic.EmitAttribute (return_attributes.Builder, ReturnType.Type, Location);
308 Constructor.ParameterInfo.ApplyAttributes (this, Constructor.ConstructorBuilder);
309 Constructor.ConstructorBuilder.SetImplementationFlags (MethodImplAttributes.Runtime);
311 parameters.ApplyAttributes (this, InvokeBuilder.MethodBuilder);
312 InvokeBuilder.MethodBuilder.SetImplementationFlags (MethodImplAttributes.Runtime);
314 if (BeginInvokeBuilder != null) {
315 BeginInvokeBuilder.ParameterInfo.ApplyAttributes (this, BeginInvokeBuilder.MethodBuilder);
316 EndInvokeBuilder.ParameterInfo.ApplyAttributes (this, EndInvokeBuilder.MethodBuilder);
318 BeginInvokeBuilder.MethodBuilder.SetImplementationFlags (MethodImplAttributes.Runtime);
319 EndInvokeBuilder.MethodBuilder.SetImplementationFlags (MethodImplAttributes.Runtime);
322 if (OptAttributes != null) {
323 OptAttributes.Emit ();
329 protected override TypeExpr[] ResolveBaseTypes (out TypeExpr base_class)
331 base_type = Compiler.BuildinTypes.MulticastDelegate;
336 protected override TypeAttributes TypeAttr {
338 return ModifiersExtensions.TypeAttr (ModFlags, IsTopLevel) |
339 TypeAttributes.Class | TypeAttributes.Sealed |
344 public override string[] ValidAttributeTargets {
346 return attribute_targets;
351 protected override bool VerifyClsCompliance ()
353 if (!base.VerifyClsCompliance ()) {
357 parameters.VerifyClsCompliance (this);
359 if (!ReturnType.Type.IsCLSCompliant ()) {
360 Report.Warning (3002, 1, Location, "Return type of `{0}' is not CLS-compliant",
361 GetSignatureForError ());
367 public static MethodSpec GetConstructor (TypeSpec delType)
369 var ctor = MemberCache.FindMember (delType, MemberFilter.Constructor (null), BindingRestriction.DeclaredOnly);
370 return (MethodSpec) ctor;
374 // Returns the "Invoke" from a delegate type
376 public static MethodSpec GetInvokeMethod (TypeSpec delType)
378 var invoke = MemberCache.FindMember (delType,
379 MemberFilter.Method (InvokeMethodName, 0, null, null),
380 BindingRestriction.DeclaredOnly);
382 return (MethodSpec) invoke;
385 public static AParametersCollection GetParameters (TypeSpec delType)
387 var invoke_mb = GetInvokeMethod (delType);
388 return invoke_mb.Parameters;
392 // 15.2 Delegate compatibility
394 public static bool IsTypeCovariant (ResolveContext rc, TypeSpec a, TypeSpec b)
397 // For each value parameter (a parameter with no ref or out modifier), an
398 // identity conversion or implicit reference conversion exists from the
399 // parameter type in D to the corresponding parameter type in M
404 if (rc.Module.Compiler.Settings.Version == LanguageVersion.ISO_1)
407 return Convert.ImplicitReferenceConversionExists (a, b);
410 public static string FullDelegateDesc (MethodSpec invoke_method)
412 return TypeManager.GetFullNameSignature (invoke_method).Replace (".Invoke", "");
415 public Expression InstanceExpression {
417 return instance_expr;
420 instance_expr = value;
426 // Base class for `NewDelegate' and `ImplicitDelegateCreation'
428 public abstract class DelegateCreation : Expression, OverloadResolver.IErrorHandler
430 protected MethodSpec constructor_method;
431 protected MethodGroupExpr method_group;
433 public static Arguments CreateDelegateMethodArguments (AParametersCollection pd, TypeSpec[] types, Location loc)
435 Arguments delegate_arguments = new Arguments (pd.Count);
436 for (int i = 0; i < pd.Count; ++i) {
437 Argument.AType atype_modifier;
438 switch (pd.FixedParameters [i].ModFlags) {
439 case Parameter.Modifier.REF:
440 atype_modifier = Argument.AType.Ref;
442 case Parameter.Modifier.OUT:
443 atype_modifier = Argument.AType.Out;
450 delegate_arguments.Add (new Argument (new TypeExpression (types [i], loc), atype_modifier));
453 return delegate_arguments;
456 public override Expression CreateExpressionTree (ResolveContext ec)
458 MemberAccess ma = new MemberAccess (new MemberAccess (new QualifiedAliasMember ("global", "System", loc), "Delegate", loc), "CreateDelegate", loc);
460 Arguments args = new Arguments (3);
461 args.Add (new Argument (new TypeOf (new TypeExpression (type, loc), loc)));
463 if (method_group.InstanceExpression == null)
464 args.Add (new Argument (new NullLiteral (loc)));
466 args.Add (new Argument (method_group.InstanceExpression));
468 args.Add (new Argument (method_group.CreateExpressionTree (ec)));
469 Expression e = new Invocation (ma, args).Resolve (ec);
473 e = Convert.ExplicitConversion (ec, e, type, loc);
477 return e.CreateExpressionTree (ec);
480 protected override Expression DoResolve (ResolveContext ec)
482 constructor_method = Delegate.GetConstructor (type);
484 var invoke_method = Delegate.GetInvokeMethod (type);
486 Arguments arguments = CreateDelegateMethodArguments (invoke_method.Parameters, invoke_method.Parameters.Types, loc);
487 method_group = method_group.OverloadResolve (ec, ref arguments, this, OverloadResolver.Restrictions.CovariantDelegate);
488 if (method_group == null)
491 var delegate_method = method_group.BestCandidate;
493 if (delegate_method.DeclaringType.IsNullableType) {
494 ec.Report.Error (1728, loc, "Cannot create delegate from method `{0}' because it is a member of System.Nullable<T> type",
495 delegate_method.GetSignatureForError ());
499 Invocation.IsSpecialMethodInvocation (ec, delegate_method, loc);
501 ExtensionMethodGroupExpr emg = method_group as ExtensionMethodGroupExpr;
503 method_group.InstanceExpression = emg.ExtensionExpression;
504 TypeSpec e_type = emg.ExtensionExpression.Type;
505 if (TypeManager.IsValueType (e_type)) {
506 ec.Report.Error (1113, loc, "Extension method `{0}' of value type `{1}' cannot be used to create delegates",
507 delegate_method.GetSignatureForError (), TypeManager.CSharpName (e_type));
511 TypeSpec rt = delegate_method.ReturnType;
512 if (!Delegate.IsTypeCovariant (ec, rt, invoke_method.ReturnType)) {
513 Expression ret_expr = new TypeExpression (rt, loc);
514 Error_ConversionFailed (ec, delegate_method, ret_expr);
517 if (delegate_method.IsConditionallyExcluded (ec.Module.Compiler, loc)) {
518 ec.Report.SymbolRelatedToPreviousError (delegate_method);
519 MethodOrOperator m = delegate_method.MemberDefinition as MethodOrOperator;
520 if (m != null && m.IsPartialDefinition) {
521 ec.Report.Error (762, loc, "Cannot create delegate from partial method declaration `{0}'",
522 delegate_method.GetSignatureForError ());
524 ec.Report.Error (1618, loc, "Cannot create delegate with `{0}' because it has a Conditional attribute",
525 TypeManager.CSharpSignature (delegate_method));
529 var expr = method_group.InstanceExpression;
530 if (expr != null && (expr.Type.IsGenericParameter || !TypeManager.IsReferenceType (expr.Type)))
531 method_group.InstanceExpression = new BoxedCast (expr, ec.BuildinTypes.Object);
533 eclass = ExprClass.Value;
537 public override void Emit (EmitContext ec)
539 if (method_group.InstanceExpression == null)
540 ec.Emit (OpCodes.Ldnull);
542 method_group.InstanceExpression.Emit (ec);
544 var delegate_method = method_group.BestCandidate;
546 // Any delegate must be sealed
547 if (!delegate_method.DeclaringType.IsDelegate && delegate_method.IsVirtual && !method_group.IsBase) {
548 ec.Emit (OpCodes.Dup);
549 ec.Emit (OpCodes.Ldvirtftn, delegate_method);
551 ec.Emit (OpCodes.Ldftn, delegate_method);
554 ec.Emit (OpCodes.Newobj, constructor_method);
557 void Error_ConversionFailed (ResolveContext ec, MethodSpec method, Expression return_type)
559 var invoke_method = Delegate.GetInvokeMethod (type);
560 string member_name = method_group.InstanceExpression != null ?
561 Delegate.FullDelegateDesc (method) :
562 TypeManager.GetFullNameSignature (method);
564 ec.Report.SymbolRelatedToPreviousError (type);
565 ec.Report.SymbolRelatedToPreviousError (method);
566 if (ec.Module.Compiler.Settings.Version == LanguageVersion.ISO_1) {
567 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",
568 TypeManager.CSharpName (method.ReturnType), member_name,
569 TypeManager.CSharpName (invoke_method.ReturnType), Delegate.FullDelegateDesc (invoke_method));
573 if (return_type == null) {
574 ec.Report.Error (123, loc, "A method or delegate `{0}' parameters do not match delegate `{1}' parameters",
575 member_name, Delegate.FullDelegateDesc (invoke_method));
579 ec.Report.Error (407, loc, "A method or delegate `{0} {1}' return type does not match delegate `{2} {3}' return type",
580 return_type.GetSignatureForError (), member_name,
581 TypeManager.CSharpName (invoke_method.ReturnType), Delegate.FullDelegateDesc (invoke_method));
584 public static bool ImplicitStandardConversionExists (ResolveContext ec, MethodGroupExpr mg, TypeSpec target_type)
586 // if (target_type == TypeManager.delegate_type || target_type == TypeManager.multicast_delegate_type)
589 var invoke = Delegate.GetInvokeMethod (target_type);
591 Arguments arguments = CreateDelegateMethodArguments (invoke.Parameters, invoke.Parameters.Types, mg.Location);
592 return mg.OverloadResolve (ec, ref arguments, null, OverloadResolver.Restrictions.CovariantDelegate | OverloadResolver.Restrictions.ProbingOnly) != null;
595 #region IErrorHandler Members
597 bool OverloadResolver.IErrorHandler.AmbiguousCandidates (ResolveContext ec, MemberSpec best, MemberSpec ambiguous)
602 bool OverloadResolver.IErrorHandler.ArgumentMismatch (ResolveContext rc, MemberSpec best, Argument arg, int index)
604 Error_ConversionFailed (rc, best as MethodSpec, null);
608 bool OverloadResolver.IErrorHandler.NoArgumentMatch (ResolveContext rc, MemberSpec best)
610 Error_ConversionFailed (rc, best as MethodSpec, null);
614 bool OverloadResolver.IErrorHandler.TypeInferenceFailed (ResolveContext rc, MemberSpec best)
623 // Created from the conversion code
625 public class ImplicitDelegateCreation : DelegateCreation
627 ImplicitDelegateCreation (TypeSpec t, MethodGroupExpr mg, Location l)
630 this.method_group = mg;
634 static public Expression Create (ResolveContext ec, MethodGroupExpr mge,
635 TypeSpec target_type, Location loc)
637 ImplicitDelegateCreation d = new ImplicitDelegateCreation (target_type, mge, loc);
638 return d.DoResolve (ec);
643 // A delegate-creation-expression, invoked from the `New' class
645 public class NewDelegate : DelegateCreation
647 public Arguments Arguments;
650 // This constructor is invoked from the `New' expression
652 public NewDelegate (TypeSpec type, Arguments Arguments, Location loc)
655 this.Arguments = Arguments;
659 protected override Expression DoResolve (ResolveContext ec)
661 if (Arguments == null || Arguments.Count != 1) {
662 ec.Report.Error (149, loc, "Method name expected");
666 Argument a = Arguments [0];
667 if (!a.ResolveMethodGroup (ec))
670 Expression e = a.Expr;
672 AnonymousMethodExpression ame = e as AnonymousMethodExpression;
673 if (ame != null && ec.Module.Compiler.Settings.Version != LanguageVersion.ISO_1) {
674 e = ame.Compatible (ec, type);
678 return e.Resolve (ec);
681 method_group = e as MethodGroupExpr;
682 if (method_group == null) {
683 if (e.Type.BuildinType == BuildinTypeSpec.Type.Dynamic) {
684 e = Convert.ImplicitConversionRequired (ec, e, type, loc);
685 } else if (!e.Type.IsDelegate) {
686 e.Error_UnexpectedKind (ec, ResolveFlags.MethodGroup | ResolveFlags.Type, loc);
691 // An argument is not a method but another delegate
693 method_group = new MethodGroupExpr (Delegate.GetInvokeMethod (e.Type), e.Type, loc);
694 method_group.InstanceExpression = e;
697 return base.DoResolve (ec);
702 // Invocation converted to delegate Invoke call
704 class DelegateInvocation : ExpressionStatement
706 readonly Expression InstanceExpr;
710 public DelegateInvocation (Expression instance_expr, Arguments args, Location loc)
712 this.InstanceExpr = instance_expr;
713 this.arguments = args;
717 public override Expression CreateExpressionTree (ResolveContext ec)
719 Arguments args = Arguments.CreateForExpressionTree (ec, this.arguments,
720 InstanceExpr.CreateExpressionTree (ec));
722 return CreateExpressionFactoryCall (ec, "Invoke", args);
725 protected override Expression DoResolve (ResolveContext ec)
727 TypeSpec del_type = InstanceExpr.Type;
728 if (del_type == null)
732 // Do only core overload resolution the rest of the checks has been
733 // done on primary expression
735 method = Delegate.GetInvokeMethod (del_type);
736 var res = new OverloadResolver (new MemberSpec[] { method }, OverloadResolver.Restrictions.DelegateInvoke, loc);
737 var valid = res.ResolveMember<MethodSpec> (ec, ref arguments);
738 if (valid == null && !res.BestCandidateIsDynamic)
741 type = method.ReturnType;
742 eclass = ExprClass.Value;
746 public override void Emit (EmitContext ec)
749 // Invocation on delegates call the virtual Invoke member
750 // so we are always `instance' calls
752 Invocation.EmitCall (ec, InstanceExpr, method, arguments, loc);
755 public override void EmitStatement (EmitContext ec)
759 // Pop the return value if there is one
761 if (type.Kind != MemberKind.Void)
762 ec.Emit (OpCodes.Pop);
765 public override System.Linq.Expressions.Expression MakeExpression (BuilderContext ctx)
767 return Invocation.MakeExpression (ctx, InstanceExpr, method, arguments);