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)
16 using System.Reflection;
17 using System.Reflection.Emit;
18 using System.Collections.Generic;
20 namespace Mono.CSharp {
23 // Delegate container implementation
25 public class Delegate : TypeContainer
27 FullNamedExpression ReturnType;
28 public readonly ParametersCompiled Parameters;
30 Constructor Constructor;
32 Method BeginInvokeBuilder;
33 Method EndInvokeBuilder;
35 static readonly string[] attribute_targets = new string [] { "type", "return" };
37 public static readonly string InvokeMethodName = "Invoke";
39 Expression instance_expr;
40 ReturnParameter return_attributes;
42 const Modifiers MethodModifiers = Modifiers.PUBLIC | Modifiers.VIRTUAL;
44 const Modifiers AllowedModifiers =
52 public Delegate (NamespaceEntry ns, DeclSpace parent, FullNamedExpression type,
53 Modifiers mod_flags, MemberName name, ParametersCompiled param_list,
55 : base (ns, parent, name, attrs, MemberKind.Delegate)
58 this.ReturnType = type;
59 ModFlags = ModifiersExtensions.Check (AllowedModifiers, mod_flags,
60 IsTopLevel ? Modifiers.INTERNAL :
61 Modifiers.PRIVATE, name.Location, Report);
62 Parameters = param_list;
63 spec = new TypeSpec (Kind, null, this, null, ModFlags | Modifiers.SEALED);
66 public override void ApplyAttributeBuilder (Attribute a, MethodSpec ctor, byte[] cdata, PredefinedAttributes pa)
68 if (a.Target == AttributeTargets.ReturnValue) {
69 if (return_attributes == null)
70 return_attributes = new ReturnParameter (this, InvokeBuilder.MethodBuilder, Location);
72 return_attributes.ApplyAttributeBuilder (a, ctor, cdata, pa);
76 base.ApplyAttributeBuilder (a, ctor, cdata, pa);
79 public override AttributeTargets AttributeTargets {
81 return AttributeTargets.Delegate;
85 protected override bool DoDefineMembers ()
87 var ctor_parameters = ParametersCompiled.CreateFullyResolved (
89 new Parameter (new TypeExpression (TypeManager.object_type, Location), "object", Parameter.Modifier.NONE, null, Location),
90 new Parameter (new TypeExpression (TypeManager.intptr_type, Location), "method", Parameter.Modifier.NONE, null, Location)
93 TypeManager.object_type,
94 TypeManager.intptr_type
98 Constructor = new Constructor (this, System.Reflection.ConstructorInfo.ConstructorName,
99 Modifiers.PUBLIC, null, ctor_parameters, null, Location);
100 Constructor.Define ();
103 // Here the various methods like Invoke, BeginInvoke etc are defined
105 // First, call the `out of band' special method for
106 // defining recursively any types we need:
110 if (!p.Resolve (this))
117 // Check accessibility
118 foreach (var partype in p.Types) {
119 if (!IsAccessibleAs (partype)) {
120 Report.SymbolRelatedToPreviousError (partype);
121 Report.Error (59, Location,
122 "Inconsistent accessibility: parameter type `{0}' is less accessible than delegate `{1}'",
123 TypeManager.CSharpName (partype), GetSignatureForError ());
127 ReturnType = ReturnType.ResolveAsTypeTerminal (this, false);
128 if (ReturnType == null)
131 var ret_type = ReturnType.Type;
134 // We don't have to check any others because they are all
135 // guaranteed to be accessible - they are standard types.
137 if (!IsAccessibleAs (ret_type)) {
138 Report.SymbolRelatedToPreviousError (ret_type);
139 Report.Error (58, Location,
140 "Inconsistent accessibility: return type `" +
141 TypeManager.CSharpName (ret_type) + "' is less " +
142 "accessible than delegate `" + GetSignatureForError () + "'");
146 CheckProtectedModifier ();
148 if (RootContext.StdLib && TypeManager.IsSpecialType (ret_type)) {
149 Method.Error1599 (Location, ret_type, Report);
153 TypeManager.CheckTypeVariance (ret_type, Variance.Covariant, this);
155 InvokeBuilder = new Method (this, null, ReturnType, MethodModifiers, new MemberName (InvokeMethodName), p, null);
156 InvokeBuilder.Define ();
159 // Don't emit async method for compiler generated delegates (e.g. dynamic site containers)
161 if (TypeManager.iasyncresult_type != null && TypeManager.asynccallback_type != null && !IsCompilerGenerated) {
162 DefineAsyncMethods (Parameters.CallingConvention);
168 void DefineAsyncMethods (CallingConventions cc)
173 ParametersCompiled async_parameters;
174 if (Parameters.Count == 0) {
175 async_parameters = ParametersCompiled.EmptyReadOnlyParameters;
177 var compiled = new Parameter[Parameters.Count];
178 for (int i = 0; i < compiled.Length; ++i)
179 compiled[i] = new Parameter (new TypeExpression (Parameters.Types[i], Location),
180 Parameters.FixedParameters[i].Name,
181 Parameters.FixedParameters[i].ModFlags & (Parameter.Modifier.REF | Parameter.Modifier.OUT),
184 async_parameters = new ParametersCompiled (compiled);
187 async_parameters = ParametersCompiled.MergeGenerated (Compiler, async_parameters, false,
189 new Parameter (new TypeExpression (TypeManager.asynccallback_type, Location), "callback", Parameter.Modifier.NONE, null, Location),
190 new Parameter (new TypeExpression (TypeManager.object_type, Location), "object", Parameter.Modifier.NONE, null, Location)
193 TypeManager.asynccallback_type,
194 TypeManager.object_type
198 BeginInvokeBuilder = new Method (this, null,
199 new TypeExpression (TypeManager.iasyncresult_type, Location), MethodModifiers,
200 new MemberName ("BeginInvoke"), async_parameters, null);
201 BeginInvokeBuilder.Define ();
204 // EndInvoke is a bit more interesting, all the parameters labeled as
205 // out or ref have to be duplicated here.
209 // Define parameters, and count out/ref parameters
211 ParametersCompiled end_parameters;
214 foreach (Parameter p in Parameters.FixedParameters) {
215 if ((p.ModFlags & Parameter.Modifier.ISBYREF) != 0)
219 if (out_params > 0) {
220 var end_param_types = new TypeSpec [out_params];
221 Parameter[] end_params = new Parameter[out_params];
224 for (int i = 0; i < Parameters.FixedParameters.Length; ++i) {
225 Parameter p = Parameters [i];
226 if ((p.ModFlags & Parameter.Modifier.ISBYREF) == 0)
229 end_param_types[param] = Parameters.Types[i];
230 end_params[param] = p;
233 end_parameters = ParametersCompiled.CreateFullyResolved (end_params, end_param_types);
235 end_parameters = ParametersCompiled.EmptyReadOnlyParameters;
238 end_parameters = ParametersCompiled.MergeGenerated (Compiler, end_parameters, false,
240 new TypeExpression (TypeManager.iasyncresult_type, Location),
241 "result", Parameter.Modifier.NONE, null, Location),
242 TypeManager.iasyncresult_type);
245 // Create method, define parameters, register parameters with type system
247 EndInvokeBuilder = new Method (this, null, ReturnType, MethodModifiers, new MemberName ("EndInvoke"), end_parameters, null);
248 EndInvokeBuilder.Define ();
251 public override void DefineConstants ()
253 if (!Parameters.IsEmpty) {
254 Parameters.ResolveDefaultValues (this);
258 public override void EmitType ()
260 if (ReturnType.Type == InternalType.Dynamic) {
261 return_attributes = new ReturnParameter (this, InvokeBuilder.MethodBuilder, Location);
262 Compiler.PredefinedAttributes.Dynamic.EmitAttribute (return_attributes.Builder);
264 var trans_flags = TypeManager.HasDynamicTypeUsed (ReturnType.Type);
265 if (trans_flags != null) {
266 var pa = Compiler.PredefinedAttributes.DynamicTransform;
267 if (pa.Constructor != null || pa.ResolveConstructor (Location, ArrayContainer.MakeType (TypeManager.bool_type))) {
268 return_attributes = new ReturnParameter (this, InvokeBuilder.MethodBuilder, Location);
269 return_attributes.Builder.SetCustomAttribute (
270 new CustomAttributeBuilder (pa.Constructor, new object [] { trans_flags }));
275 Parameters.ApplyAttributes (this, InvokeBuilder.MethodBuilder);
277 Constructor.ConstructorBuilder.SetImplementationFlags (MethodImplAttributes.Runtime);
278 InvokeBuilder.MethodBuilder.SetImplementationFlags (MethodImplAttributes.Runtime);
280 if (BeginInvokeBuilder != null) {
281 BeginInvokeBuilder.ParameterInfo.ApplyAttributes (this, BeginInvokeBuilder.MethodBuilder);
283 BeginInvokeBuilder.MethodBuilder.SetImplementationFlags (MethodImplAttributes.Runtime);
284 EndInvokeBuilder.MethodBuilder.SetImplementationFlags (MethodImplAttributes.Runtime);
287 if (OptAttributes != null) {
288 OptAttributes.Emit ();
294 protected override TypeExpr[] ResolveBaseTypes (out TypeExpr base_class)
296 base_type = TypeManager.multicast_delegate_type;
301 protected override TypeAttributes TypeAttr {
303 return ModifiersExtensions.TypeAttr (ModFlags, IsTopLevel) |
304 TypeAttributes.Class | TypeAttributes.Sealed |
309 public override string[] ValidAttributeTargets {
311 return attribute_targets;
316 protected override bool VerifyClsCompliance ()
318 if (!base.VerifyClsCompliance ()) {
322 Parameters.VerifyClsCompliance (this);
324 if (!ReturnType.Type.IsCLSCompliant ()) {
325 Report.Warning (3002, 1, Location, "Return type of `{0}' is not CLS-compliant",
326 GetSignatureForError ());
332 public static MethodSpec GetConstructor (CompilerContext ctx, TypeSpec container_type, TypeSpec delType)
334 var ctor = MemberCache.FindMember (delType, MemberFilter.Constructor (null), BindingRestriction.DeclaredOnly);
335 return (MethodSpec) ctor;
339 // Returns the "Invoke" from a delegate type
341 public static MethodSpec GetInvokeMethod (CompilerContext ctx, TypeSpec delType)
343 var invoke = MemberCache.FindMember (delType,
344 MemberFilter.Method (InvokeMethodName, 0, null, null),
345 BindingRestriction.DeclaredOnly);
347 return (MethodSpec) invoke;
350 public static AParametersCollection GetParameters (CompilerContext ctx, TypeSpec delType)
352 var invoke_mb = GetInvokeMethod (ctx, delType);
353 return invoke_mb.Parameters;
357 // 15.2 Delegate compatibility
359 public static bool IsTypeCovariant (Expression a, TypeSpec b)
362 // For each value parameter (a parameter with no ref or out modifier), an
363 // identity conversion or implicit reference conversion exists from the
364 // parameter type in D to the corresponding parameter type in M
369 if (RootContext.Version == LanguageVersion.ISO_1)
372 return Convert.ImplicitReferenceConversionExists (a, b);
375 public static string FullDelegateDesc (MethodSpec invoke_method)
377 return TypeManager.GetFullNameSignature (invoke_method).Replace (".Invoke", "");
380 public Expression InstanceExpression {
382 return instance_expr;
385 instance_expr = value;
391 // Base class for `NewDelegate' and `ImplicitDelegateCreation'
393 public abstract class DelegateCreation : Expression, OverloadResolver.IErrorHandler
395 protected MethodSpec constructor_method;
396 protected MethodGroupExpr method_group;
398 public static Arguments CreateDelegateMethodArguments (AParametersCollection pd, TypeSpec[] types, Location loc)
400 Arguments delegate_arguments = new Arguments (pd.Count);
401 for (int i = 0; i < pd.Count; ++i) {
402 Argument.AType atype_modifier;
403 switch (pd.FixedParameters [i].ModFlags) {
404 case Parameter.Modifier.REF:
405 atype_modifier = Argument.AType.Ref;
407 case Parameter.Modifier.OUT:
408 atype_modifier = Argument.AType.Out;
415 delegate_arguments.Add (new Argument (new TypeExpression (types [i], loc), atype_modifier));
418 return delegate_arguments;
421 public override Expression CreateExpressionTree (ResolveContext ec)
423 MemberAccess ma = new MemberAccess (new MemberAccess (new QualifiedAliasMember ("global", "System", loc), "Delegate", loc), "CreateDelegate", loc);
425 Arguments args = new Arguments (3);
426 args.Add (new Argument (new TypeOf (new TypeExpression (type, loc), loc)));
427 args.Add (new Argument (new NullLiteral (loc)));
428 args.Add (new Argument (method_group.CreateExpressionTree (ec)));
429 Expression e = new Invocation (ma, args).Resolve (ec);
433 e = Convert.ExplicitConversion (ec, e, type, loc);
437 return e.CreateExpressionTree (ec);
440 protected override Expression DoResolve (ResolveContext ec)
442 constructor_method = Delegate.GetConstructor (ec.Compiler, ec.CurrentType, type);
444 var invoke_method = Delegate.GetInvokeMethod (ec.Compiler, type);
446 Arguments arguments = CreateDelegateMethodArguments (invoke_method.Parameters, invoke_method.Parameters.Types, loc);
447 method_group = method_group.OverloadResolve (ec, ref arguments, this, OverloadResolver.Restrictions.CovariantDelegate);
448 if (method_group == null)
451 var delegate_method = method_group.BestCandidate;
453 if (TypeManager.IsNullableType (delegate_method.DeclaringType)) {
454 ec.Report.Error (1728, loc, "Cannot create delegate from method `{0}' because it is a member of System.Nullable<T> type",
455 delegate_method.GetSignatureForError ());
459 Invocation.IsSpecialMethodInvocation (ec, delegate_method, loc);
461 ExtensionMethodGroupExpr emg = method_group as ExtensionMethodGroupExpr;
463 method_group.InstanceExpression = emg.ExtensionExpression;
464 TypeSpec e_type = emg.ExtensionExpression.Type;
465 if (TypeManager.IsValueType (e_type)) {
466 ec.Report.Error (1113, loc, "Extension method `{0}' of value type `{1}' cannot be used to create delegates",
467 delegate_method.GetSignatureForError (), TypeManager.CSharpName (e_type));
471 TypeSpec rt = delegate_method.ReturnType;
472 Expression ret_expr = new TypeExpression (rt, loc);
473 if (!Delegate.IsTypeCovariant (ret_expr, invoke_method.ReturnType)) {
474 Error_ConversionFailed (ec, delegate_method, ret_expr);
477 if (delegate_method.IsConditionallyExcluded (loc)) {
478 ec.Report.SymbolRelatedToPreviousError (delegate_method);
479 MethodOrOperator m = delegate_method.MemberDefinition as MethodOrOperator;
480 if (m != null && m.IsPartialDefinition) {
481 ec.Report.Error (762, loc, "Cannot create delegate from partial method declaration `{0}'",
482 delegate_method.GetSignatureForError ());
484 ec.Report.Error (1618, loc, "Cannot create delegate with `{0}' because it has a Conditional attribute",
485 TypeManager.CSharpSignature (delegate_method));
489 var expr = method_group.InstanceExpression;
490 if (expr != null && (expr.Type.IsGenericParameter || !TypeManager.IsReferenceType (expr.Type)))
491 method_group.InstanceExpression = new BoxedCast (expr, TypeManager.object_type);
493 eclass = ExprClass.Value;
497 public override void Emit (EmitContext ec)
499 if (method_group.InstanceExpression == null)
500 ec.Emit (OpCodes.Ldnull);
502 method_group.InstanceExpression.Emit (ec);
504 var delegate_method = method_group.BestCandidate;
506 // Any delegate must be sealed
507 if (!delegate_method.DeclaringType.IsDelegate && delegate_method.IsVirtual && !method_group.IsBase) {
508 ec.Emit (OpCodes.Dup);
509 ec.Emit (OpCodes.Ldvirtftn, delegate_method);
511 ec.Emit (OpCodes.Ldftn, delegate_method);
514 ec.Emit (OpCodes.Newobj, constructor_method);
517 void Error_ConversionFailed (ResolveContext ec, MethodSpec method, Expression return_type)
519 var invoke_method = Delegate.GetInvokeMethod (ec.Compiler, type);
520 string member_name = method_group.InstanceExpression != null ?
521 Delegate.FullDelegateDesc (method) :
522 TypeManager.GetFullNameSignature (method);
524 ec.Report.SymbolRelatedToPreviousError (type);
525 ec.Report.SymbolRelatedToPreviousError (method);
526 if (RootContext.Version == LanguageVersion.ISO_1) {
527 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",
528 TypeManager.CSharpName (method.ReturnType), member_name,
529 TypeManager.CSharpName (invoke_method.ReturnType), Delegate.FullDelegateDesc (invoke_method));
533 if (return_type == null) {
534 ec.Report.Error (123, loc, "A method or delegate `{0}' parameters do not match delegate `{1}' parameters",
535 member_name, Delegate.FullDelegateDesc (invoke_method));
539 ec.Report.Error (407, loc, "A method or delegate `{0} {1}' return type does not match delegate `{2} {3}' return type",
540 return_type.GetSignatureForError (), member_name,
541 TypeManager.CSharpName (invoke_method.ReturnType), Delegate.FullDelegateDesc (invoke_method));
544 public static bool ImplicitStandardConversionExists (ResolveContext ec, MethodGroupExpr mg, TypeSpec target_type)
546 if (target_type == TypeManager.delegate_type || target_type == TypeManager.multicast_delegate_type)
549 var invoke = Delegate.GetInvokeMethod (ec.Compiler, target_type);
551 Arguments arguments = CreateDelegateMethodArguments (invoke.Parameters, invoke.Parameters.Types, mg.Location);
552 return mg.OverloadResolve (ec, ref arguments, null, OverloadResolver.Restrictions.CovariantDelegate | OverloadResolver.Restrictions.ProbingOnly) != null;
555 #region IErrorHandler Members
557 bool OverloadResolver.IErrorHandler.AmbiguousCandidates (ResolveContext ec, MemberSpec best, MemberSpec ambiguous)
562 bool OverloadResolver.IErrorHandler.ArgumentMismatch (ResolveContext rc, MemberSpec best, Argument arg, int index)
564 Error_ConversionFailed (rc, best as MethodSpec, null);
568 bool OverloadResolver.IErrorHandler.NoArgumentMatch (ResolveContext rc, MemberSpec best)
570 Error_ConversionFailed (rc, best as MethodSpec, null);
574 bool OverloadResolver.IErrorHandler.TypeInferenceFailed (ResolveContext rc, MemberSpec best)
583 // Created from the conversion code
585 public class ImplicitDelegateCreation : DelegateCreation
587 ImplicitDelegateCreation (TypeSpec t, MethodGroupExpr mg, Location l)
590 this.method_group = mg;
594 static public Expression Create (ResolveContext ec, MethodGroupExpr mge,
595 TypeSpec target_type, Location loc)
597 ImplicitDelegateCreation d = new ImplicitDelegateCreation (target_type, mge, loc);
598 return d.DoResolve (ec);
603 // A delegate-creation-expression, invoked from the `New' class
605 public class NewDelegate : DelegateCreation
607 public Arguments Arguments;
610 // This constructor is invoked from the `New' expression
612 public NewDelegate (TypeSpec type, Arguments Arguments, Location loc)
615 this.Arguments = Arguments;
619 protected override Expression DoResolve (ResolveContext ec)
621 if (Arguments == null || Arguments.Count != 1) {
622 ec.Report.Error (149, loc, "Method name expected");
626 Argument a = Arguments [0];
627 if (!a.ResolveMethodGroup (ec))
630 Expression e = a.Expr;
632 AnonymousMethodExpression ame = e as AnonymousMethodExpression;
633 if (ame != null && RootContext.Version != LanguageVersion.ISO_1) {
634 e = ame.Compatible (ec, type);
638 return e.Resolve (ec);
641 method_group = e as MethodGroupExpr;
642 if (method_group == null) {
643 if (e.Type == InternalType.Dynamic) {
644 e = Convert.ImplicitConversionRequired (ec, e, type, loc);
645 } else if (!e.Type.IsDelegate) {
646 e.Error_UnexpectedKind (ec, ResolveFlags.MethodGroup | ResolveFlags.Type, loc);
651 // An argument is not a method but another delegate
653 method_group = new MethodGroupExpr (Delegate.GetInvokeMethod (ec.Compiler, e.Type), e.Type, loc);
654 method_group.InstanceExpression = e;
657 return base.DoResolve (ec);
662 // Invocation converted to delegate Invoke call
664 class DelegateInvocation : ExpressionStatement
666 readonly Expression InstanceExpr;
670 public DelegateInvocation (Expression instance_expr, Arguments args, Location loc)
672 this.InstanceExpr = instance_expr;
673 this.arguments = args;
677 public override Expression CreateExpressionTree (ResolveContext ec)
679 Arguments args = Arguments.CreateForExpressionTree (ec, this.arguments,
680 InstanceExpr.CreateExpressionTree (ec));
682 return CreateExpressionFactoryCall (ec, "Invoke", args);
685 protected override Expression DoResolve (ResolveContext ec)
687 if (InstanceExpr is EventExpr) {
688 ((EventExpr) InstanceExpr).Error_CannotAssign (ec);
692 TypeSpec del_type = InstanceExpr.Type;
693 if (del_type == null)
697 // Do only core overload resolution the rest of the checks has been
698 // done on primary expression
700 method = Delegate.GetInvokeMethod (ec.Compiler, del_type);
701 var res = new OverloadResolver (new MemberSpec[] { method }, OverloadResolver.Restrictions.DelegateInvoke, loc);
702 var valid = res.ResolveMember<MethodSpec> (ec, ref arguments);
703 if (valid == null && !res.BestCandidateIsDynamic)
706 type = method.ReturnType;
707 eclass = ExprClass.Value;
711 public override void Emit (EmitContext ec)
714 // Invocation on delegates call the virtual Invoke member
715 // so we are always `instance' calls
717 Invocation.EmitCall (ec, InstanceExpr, method, arguments, loc);
720 public override void EmitStatement (EmitContext ec)
724 // Pop the return value if there is one
726 if (type != TypeManager.void_type)
727 ec.Emit (OpCodes.Pop);
730 public override System.Linq.Expressions.Expression MakeExpression (BuilderContext ctx)
732 return Invocation.MakeExpression (ctx, InstanceExpr, method, arguments);