/NRefactory/ICSharpCode.NRefactory.CSharp/Parser/mcs/method.cs

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   1//
   2// method.cs: Method based declarations
   3//
   4// Authors: Miguel de Icaza (miguel@gnu.org)
   5//          Martin Baulig (martin@ximian.com)
   6//          Marek Safar (marek.safar@gmail.com)
   7//
   8// Dual licensed under the terms of the MIT X11 or GNU GPL
   9//
  10// Copyright 2001, 2002, 2003 Ximian, Inc (http://www.ximian.com)
  11// Copyright 2004-2008 Novell, Inc
  12// Copyright 2011 Xamarin Inc.
  13//
  14
  15using System;
  16using System.Collections.Generic;
  17using System.Security;
  18using System.Security.Permissions;
  19using System.Text;
  20using System.Linq;
  21using Mono.CompilerServices.SymbolWriter;
  22using System.Runtime.CompilerServices;
  23
  24#if NET_2_1
  25using XmlElement = System.Object;
  26#else
  27using System.Xml;
  28#endif
  29
  30#if STATIC
  31using MetaType = IKVM.Reflection.Type;
  32using SecurityType = System.Collections.Generic.List<IKVM.Reflection.Emit.CustomAttributeBuilder>;
  33using IKVM.Reflection;
  34using IKVM.Reflection.Emit;
  35#else
  36using MetaType = System.Type;
  37using SecurityType = System.Collections.Generic.Dictionary<System.Security.Permissions.SecurityAction, System.Security.PermissionSet>;
  38using System.Reflection;
  39using System.Reflection.Emit;
  40#endif
  41
  42namespace Mono.CSharp {
  43
  44	public abstract class MethodCore : InterfaceMemberBase, IParametersMember
  45	{
  46		protected ParametersCompiled parameters;
  47		protected ToplevelBlock block;
  48		protected MethodSpec spec;
  49
  50		protected MethodCore (TypeDefinition parent, FullNamedExpression type, Modifiers mod, Modifiers allowed_mod,
  51			MemberName name, Attributes attrs, ParametersCompiled parameters)
  52			: base (parent, type, mod, allowed_mod, name, attrs)
  53		{
  54			this.parameters = parameters;
  55		}
  56
  57		public override Variance ExpectedMemberTypeVariance {
  58			get {
  59				return Variance.Covariant;
  60			}
  61		}
  62
  63		//
  64		//  Returns the System.Type array for the parameters of this method
  65		//
  66		public TypeSpec [] ParameterTypes {
  67			get {
  68				return parameters.Types;
  69			}
  70		}
  71
  72		public ParametersCompiled ParameterInfo {
  73			get {
  74				return parameters;
  75			}
  76		}
  77
  78		AParametersCollection IParametersMember.Parameters {
  79			get { return parameters; }
  80		}
  81		
  82		public ToplevelBlock Block {
  83			get {
  84				return block;
  85			}
  86
  87			set {
  88				block = value;
  89			}
  90		}
  91
  92		public CallingConventions CallingConventions {
  93			get {
  94				CallingConventions cc = parameters.CallingConvention;
  95				if (!IsInterface)
  96					if ((ModFlags & Modifiers.STATIC) == 0)
  97						cc |= CallingConventions.HasThis;
  98
  99				// FIXME: How is `ExplicitThis' used in C#?
 100			
 101				return cc;
 102			}
 103		}
 104
 105		protected override bool CheckOverrideAgainstBase (MemberSpec base_member)
 106		{
 107			bool res = base.CheckOverrideAgainstBase (base_member);
 108
 109			//
 110			// Check that the permissions are not being changed
 111			//
 112			if (!CheckAccessModifiers (this, base_member)) {
 113				Error_CannotChangeAccessModifiers (this, base_member);
 114				res = false;
 115			}
 116
 117			return res;
 118		}
 119
 120		protected override bool CheckBase ()
 121		{
 122			// Check whether arguments were correct.
 123			if (!DefineParameters (parameters))
 124				return false;
 125
 126			return base.CheckBase ();
 127		}
 128
 129		//
 130		//   Represents header string for documentation comment.
 131		//
 132		public override string DocCommentHeader 
 133		{
 134			get { return "M:"; }
 135		}
 136
 137		public override void Emit ()
 138		{
 139			if ((ModFlags & Modifiers.COMPILER_GENERATED) == 0) {
 140				parameters.CheckConstraints (this);
 141			}
 142
 143			base.Emit ();
 144		}
 145
 146		public override bool EnableOverloadChecks (MemberCore overload)
 147		{
 148			if (overload is MethodCore) {
 149				caching_flags |= Flags.MethodOverloadsExist;
 150				return true;
 151			}
 152
 153			if (overload is AbstractPropertyEventMethod)
 154				return true;
 155
 156			return base.EnableOverloadChecks (overload);
 157		}
 158
 159		public override string GetSignatureForDocumentation ()
 160		{
 161			string s = base.GetSignatureForDocumentation ();
 162			if (MemberName.Arity > 0)
 163				s += "``" + MemberName.Arity.ToString ();
 164
 165			return s + parameters.GetSignatureForDocumentation ();
 166		}
 167
 168		public MethodSpec Spec {
 169			get { return spec; }
 170		}
 171
 172		protected override bool VerifyClsCompliance ()
 173		{
 174			if (!base.VerifyClsCompliance ())
 175				return false;
 176
 177			if (parameters.HasArglist) {
 178				Report.Warning (3000, 1, Location, "Methods with variable arguments are not CLS-compliant");
 179			}
 180
 181			if (member_type != null && !member_type.IsCLSCompliant ()) {
 182				Report.Warning (3002, 1, Location, "Return type of `{0}' is not CLS-compliant",
 183					GetSignatureForError ());
 184			}
 185
 186			parameters.VerifyClsCompliance (this);
 187			return true;
 188		}
 189	}
 190
 191	public interface IGenericMethodDefinition : IMethodDefinition
 192	{
 193		TypeParameterSpec[] TypeParameters { get; }
 194		int TypeParametersCount { get; }
 195
 196//		MethodInfo MakeGenericMethod (TypeSpec[] targs);
 197	}
 198
 199	public sealed class MethodSpec : MemberSpec, IParametersMember
 200	{
 201		MethodBase inflatedMetaInfo;
 202		AParametersCollection parameters;
 203		TypeSpec returnType;
 204
 205		TypeSpec[] targs;
 206		TypeParameterSpec[] constraints;
 207
 208		public static readonly MethodSpec Excluded = new MethodSpec (MemberKind.Method, InternalType.FakeInternalType, null, null, ParametersCompiled.EmptyReadOnlyParameters, 0);
 209
 210		public MethodSpec (MemberKind kind, TypeSpec declaringType, IMethodDefinition details, TypeSpec returnType,
 211			AParametersCollection parameters, Modifiers modifiers)
 212			: base (kind, declaringType, details, modifiers)
 213		{
 214			this.parameters = parameters;
 215			this.returnType = returnType;
 216		}
 217
 218		#region Properties
 219
 220		public override int Arity {
 221			get {
 222				return IsGeneric ? GenericDefinition.TypeParametersCount : 0;
 223			}
 224		}
 225
 226		public TypeParameterSpec[] Constraints {
 227			get {
 228				if (constraints == null && IsGeneric)
 229					constraints = GenericDefinition.TypeParameters;
 230
 231				return constraints;
 232			}
 233		}
 234
 235		public bool IsConstructor {
 236			get {
 237				return Kind == MemberKind.Constructor;
 238			}
 239		}
 240
 241		public new IMethodDefinition MemberDefinition {
 242			get {
 243				return (IMethodDefinition) definition;
 244			}
 245		}
 246
 247		public IGenericMethodDefinition GenericDefinition {
 248			get {
 249				return (IGenericMethodDefinition) definition;
 250			}
 251		}
 252
 253		public bool IsAsync {
 254			get {
 255				return (Modifiers & Modifiers.ASYNC) != 0;
 256			}
 257		}
 258
 259		public bool IsExtensionMethod {
 260			get {
 261				return IsStatic && parameters.HasExtensionMethodType;
 262			}
 263		}
 264
 265		public bool IsSealed {
 266			get {
 267				return (Modifiers & Modifiers.SEALED) != 0;
 268			}
 269		}
 270
 271		// When is virtual or abstract
 272		public bool IsVirtual {
 273			get {
 274				return (Modifiers & (Modifiers.VIRTUAL | Modifiers.ABSTRACT | Modifiers.OVERRIDE)) != 0;
 275			}
 276		}
 277
 278		public bool IsReservedMethod {
 279			get {
 280				return Kind == MemberKind.Operator || IsAccessor;
 281			}
 282		}
 283
 284		TypeSpec IInterfaceMemberSpec.MemberType {
 285			get {
 286				return returnType;
 287			}
 288		}
 289
 290		public AParametersCollection Parameters {
 291			get { 
 292				return parameters;
 293			}
 294		}
 295
 296		public TypeSpec ReturnType {
 297			get {
 298				return returnType;
 299			}
 300		}
 301
 302		public TypeSpec[] TypeArguments {
 303			get {
 304				return targs;
 305			}
 306		}
 307
 308		#endregion
 309
 310		public MethodSpec GetGenericMethodDefinition ()
 311		{
 312			if (!IsGeneric && !DeclaringType.IsGeneric)
 313				return this;
 314
 315			return MemberCache.GetMember (declaringType, this);
 316		}
 317
 318		public MethodBase GetMetaInfo ()
 319		{
 320			//
 321			// inflatedMetaInfo is extra field needed for cases where we
 322			// inflate method but another nested type can later inflate
 323			// again (the cache would be build with inflated metaInfo) and
 324			// TypeBuilder can work with method definitions only
 325			//
 326			if (inflatedMetaInfo == null) {
 327				if ((state & StateFlags.PendingMetaInflate) != 0) {
 328					var dt_meta = DeclaringType.GetMetaInfo ();
 329
 330					if (DeclaringType.IsTypeBuilder) {
 331						if (IsConstructor)
 332							inflatedMetaInfo = TypeBuilder.GetConstructor (dt_meta, (ConstructorInfo) MemberDefinition.Metadata);
 333						else
 334							inflatedMetaInfo = TypeBuilder.GetMethod (dt_meta, (MethodInfo) MemberDefinition.Metadata);
 335					} else {
 336#if STATIC
 337						// it should not be reached
 338						throw new NotImplementedException ();
 339#else
 340						inflatedMetaInfo = MethodInfo.GetMethodFromHandle (MemberDefinition.Metadata.MethodHandle, dt_meta.TypeHandle);
 341#endif
 342					}
 343
 344					state &= ~StateFlags.PendingMetaInflate;
 345				} else {
 346					inflatedMetaInfo = MemberDefinition.Metadata;
 347				}
 348			}
 349
 350			if ((state & StateFlags.PendingMakeMethod) != 0) {
 351				var sre_targs = new MetaType[targs.Length];
 352				for (int i = 0; i < sre_targs.Length; ++i)
 353					sre_targs[i] = targs[i].GetMetaInfo ();
 354
 355				inflatedMetaInfo = ((MethodInfo) inflatedMetaInfo).MakeGenericMethod (sre_targs);
 356				state &= ~StateFlags.PendingMakeMethod;
 357			}
 358
 359			return inflatedMetaInfo;
 360		}
 361
 362		public override string GetSignatureForDocumentation ()
 363		{
 364			string name;
 365			switch (Kind) {
 366			case MemberKind.Constructor:
 367				name = "#ctor";
 368				break;
 369			case MemberKind.Method:
 370				if (Arity > 0)
 371					name = Name + "``" + Arity.ToString ();
 372				else
 373					name = Name;
 374
 375				break;
 376			default:
 377				name = Name;
 378				break;
 379			}
 380
 381			name = DeclaringType.GetSignatureForDocumentation () + "." + name + parameters.GetSignatureForDocumentation ();
 382			if (Kind == MemberKind.Operator) {
 383				var op = Operator.GetType (Name).Value;
 384				if (op == Operator.OpType.Explicit || op == Operator.OpType.Implicit) {
 385					name += "~" + ReturnType.GetSignatureForDocumentation ();
 386				}
 387			}
 388
 389			return name;
 390		}
 391
 392		public override string GetSignatureForError ()
 393		{
 394			string name;
 395			if (IsConstructor) {
 396				name = DeclaringType.GetSignatureForError () + "." + DeclaringType.Name;
 397			} else if (Kind == MemberKind.Operator) {
 398				var op = Operator.GetType (Name).Value;
 399				if (op == Operator.OpType.Implicit || op == Operator.OpType.Explicit) {
 400					name = DeclaringType.GetSignatureForError () + "." + Operator.GetName (op) + " operator " + returnType.GetSignatureForError ();
 401				} else {
 402					name = DeclaringType.GetSignatureForError () + ".operator " + Operator.GetName (op);
 403				}
 404			} else if (IsAccessor) {
 405				int split = Name.IndexOf ('_');
 406				name = Name.Substring (split + 1);
 407				var postfix = Name.Substring (0, split);
 408				if (split == 3) {
 409					var pc = parameters.Count;
 410					if (pc > 0 && postfix == "get") {
 411						name = "this" + parameters.GetSignatureForError ("[", "]", pc);
 412					} else if (pc > 1 && postfix == "set") {
 413						name = "this" + parameters.GetSignatureForError ("[", "]", pc - 1);
 414					}
 415				}
 416
 417				return DeclaringType.GetSignatureForError () + "." + name + "." + postfix;
 418			} else {
 419				name = base.GetSignatureForError ();
 420				if (targs != null)
 421					name += "<" + TypeManager.CSharpName (targs) + ">";
 422				else if (IsGeneric)
 423					name += "<" + TypeManager.CSharpName (GenericDefinition.TypeParameters) + ">";
 424			}
 425
 426			return name + parameters.GetSignatureForError ();
 427		}
 428
 429		public override MemberSpec InflateMember (TypeParameterInflator inflator)
 430		{
 431			var ms = (MethodSpec) base.InflateMember (inflator);
 432			ms.inflatedMetaInfo = null;
 433			ms.returnType = inflator.Inflate (returnType);
 434			ms.parameters = parameters.Inflate (inflator);
 435			if (IsGeneric)
 436				ms.constraints = TypeParameterSpec.InflateConstraints (inflator, Constraints);
 437
 438			return ms;
 439		}
 440
 441		public MethodSpec MakeGenericMethod (IMemberContext context, params TypeSpec[] targs)
 442		{
 443			if (targs == null)
 444				throw new ArgumentNullException ();
 445// TODO MemberCache
 446//			if (generic_intances != null && generic_intances.TryGetValue (targs, out ginstance))
 447//				return ginstance;
 448
 449			//if (generic_intances == null)
 450			//    generic_intances = new Dictionary<TypeSpec[], Method> (TypeSpecArrayComparer.Default);
 451
 452			var inflator = new TypeParameterInflator (context, DeclaringType, GenericDefinition.TypeParameters, targs);
 453
 454			var inflated = (MethodSpec) MemberwiseClone ();
 455			inflated.declaringType = inflator.TypeInstance;
 456			inflated.returnType = inflator.Inflate (returnType);
 457			inflated.parameters = parameters.Inflate (inflator);
 458			inflated.targs = targs;
 459			inflated.constraints = TypeParameterSpec.InflateConstraints (inflator, constraints ?? GenericDefinition.TypeParameters);
 460			inflated.state |= StateFlags.PendingMakeMethod;
 461
 462			//			if (inflated.parent == null)
 463			//				inflated.parent = parent;
 464
 465			//generic_intances.Add (targs, inflated);
 466			return inflated;
 467		}
 468
 469		public MethodSpec Mutate (TypeParameterMutator mutator)
 470		{
 471			var targs = TypeArguments;
 472			if (targs != null)
 473				targs = mutator.Mutate (targs);
 474
 475			var decl = DeclaringType;
 476			if (DeclaringType.IsGenericOrParentIsGeneric) {
 477				decl = mutator.Mutate (decl);
 478			}
 479
 480			if (targs == TypeArguments && decl == DeclaringType)
 481				return this;
 482
 483			var ms = (MethodSpec) MemberwiseClone ();
 484			if (decl != DeclaringType) {
 485				ms.inflatedMetaInfo = null;
 486				ms.declaringType = decl;
 487				ms.state |= StateFlags.PendingMetaInflate;
 488			}
 489
 490			if (targs != null) {
 491				ms.targs = targs;
 492				ms.state |= StateFlags.PendingMakeMethod;
 493			}
 494
 495			return ms;
 496		}
 497
 498		public override List<MissingTypeSpecReference> ResolveMissingDependencies (MemberSpec caller)
 499		{
 500			var missing = returnType.ResolveMissingDependencies (this);
 501			foreach (var pt in parameters.Types) {
 502				var m = pt.GetMissingDependencies (this);
 503				if (m == null)
 504					continue;
 505
 506				if (missing == null)
 507					missing = new List<MissingTypeSpecReference> ();
 508
 509				missing.AddRange (m);
 510			}
 511
 512			if (Arity > 0) {
 513				foreach (var tp in GenericDefinition.TypeParameters) {
 514					var m = tp.GetMissingDependencies (this);
 515
 516					if (m == null)
 517						continue;
 518
 519					if (missing == null)
 520						missing = new List<MissingTypeSpecReference> ();
 521
 522					missing.AddRange (m);
 523				}
 524			}
 525
 526			return missing;			
 527		}
 528	}
 529
 530	public abstract class MethodOrOperator : MethodCore, IMethodData, IMethodDefinition
 531	{
 532		ReturnParameter return_attributes;
 533		SecurityType declarative_security;
 534		protected MethodData MethodData;
 535
 536		static readonly string[] attribute_targets = new string [] { "method", "return" };
 537
 538		protected MethodOrOperator (TypeDefinition parent, FullNamedExpression type, Modifiers mod, Modifiers allowed_mod, MemberName name,
 539				Attributes attrs, ParametersCompiled parameters)
 540			: base (parent, type, mod, allowed_mod, name, attrs, parameters)
 541		{
 542		}
 543
 544		public override void ApplyAttributeBuilder (Attribute a, MethodSpec ctor, byte[] cdata, PredefinedAttributes pa)
 545		{
 546			if (a.Target == AttributeTargets.ReturnValue) {
 547				if (return_attributes == null)
 548					return_attributes = new ReturnParameter (this, MethodBuilder, Location);
 549
 550				return_attributes.ApplyAttributeBuilder (a, ctor, cdata, pa);
 551				return;
 552			}
 553
 554			if (a.Type == pa.MethodImpl) {
 555				if ((ModFlags & Modifiers.ASYNC) != 0 && (a.GetMethodImplOptions () & MethodImplOptions.Synchronized) != 0) {
 556					Report.Error (4015, a.Location, "`{0}': Async methods cannot use `MethodImplOptions.Synchronized'",
 557						GetSignatureForError ());
 558				}
 559
 560				is_external_implementation = a.IsInternalCall ();
 561			} else if (a.Type == pa.DllImport) {
 562				const Modifiers extern_static = Modifiers.EXTERN | Modifiers.STATIC;
 563				if ((ModFlags & extern_static) != extern_static) {
 564					Report.Error (601, a.Location, "The DllImport attribute must be specified on a method marked `static' and `extern'");
 565				}
 566
 567				if (MemberName.IsGeneric || Parent.IsGenericOrParentIsGeneric) {
 568					Report.Error (7042, a.Location, 
 569						"The DllImport attribute cannot be applied to a method that is generic or contained in a generic type");
 570				}
 571
 572				is_external_implementation = true;
 573			}
 574
 575			if (a.IsValidSecurityAttribute ()) {
 576				a.ExtractSecurityPermissionSet (ctor, ref declarative_security);
 577				return;
 578			}
 579
 580			if (MethodBuilder != null)
 581				MethodBuilder.SetCustomAttribute ((ConstructorInfo) ctor.GetMetaInfo (), cdata);
 582		}
 583
 584		public override AttributeTargets AttributeTargets {
 585			get {
 586				return AttributeTargets.Method; 
 587			}
 588		}
 589
 590		MethodBase IMethodDefinition.Metadata {
 591			get {
 592				return MethodData.MethodBuilder;
 593			}
 594		}
 595
 596		// TODO: Remove and use MethodData abstraction
 597		public MethodBuilder MethodBuilder {
 598			get {
 599				return MethodData.MethodBuilder;
 600			}
 601		}
 602
 603		protected override bool CheckForDuplications ()
 604		{
 605			return Parent.MemberCache.CheckExistingMembersOverloads (this, parameters);
 606		}
 607
 608		public virtual EmitContext CreateEmitContext (ILGenerator ig, SourceMethodBuilder sourceMethod)
 609		{
 610			return new EmitContext (this, ig, MemberType, sourceMethod);
 611		}
 612
 613		public override bool Define ()
 614		{
 615			if (!base.Define ())
 616				return false;
 617
 618			if (!CheckBase ())
 619				return false;
 620
 621			MemberKind kind;
 622			if (this is Operator)
 623				kind = MemberKind.Operator;
 624			else if (this is Destructor)
 625				kind = MemberKind.Destructor;
 626			else
 627				kind = MemberKind.Method;
 628
 629			string explicit_name;
 630
 631			if (IsPartialDefinition) {
 632				caching_flags &= ~Flags.Excluded_Undetected;
 633				caching_flags |= Flags.Excluded;
 634
 635				// Add to member cache only when a partial method implementation has not been found yet
 636				if ((caching_flags & Flags.PartialDefinitionExists) != 0)
 637					return true;
 638
 639				if (IsExplicitImpl)
 640					return true;
 641
 642				explicit_name = null;
 643			} else {
 644				MethodData = new MethodData (this, ModFlags, flags, this, base_method);
 645
 646				if (!MethodData.Define (Parent.PartialContainer, GetFullName (MemberName)))
 647					return false;
 648
 649				explicit_name = MethodData.MetadataName;
 650			}
 651
 652			spec = new MethodSpec (kind, Parent.Definition, this, ReturnType, parameters, ModFlags);
 653			if (MemberName.Arity > 0)
 654				spec.IsGeneric = true;
 655
 656			Parent.MemberCache.AddMember (this, explicit_name, spec);
 657
 658			return true;
 659		}
 660
 661		protected override void DoMemberTypeIndependentChecks ()
 662		{
 663			base.DoMemberTypeIndependentChecks ();
 664
 665			CheckAbstractAndExtern (block != null);
 666
 667			if ((ModFlags & Modifiers.PARTIAL) != 0) {
 668				for (int i = 0; i < parameters.Count; ++i) {
 669					IParameterData p = parameters.FixedParameters [i];
 670					if ((p.ModFlags & Parameter.Modifier.OUT) != 0) {
 671						Report.Error (752, Location, "`{0}': A partial method parameters cannot use `out' modifier",
 672							GetSignatureForError ());
 673					}
 674
 675					if (p.HasDefaultValue && IsPartialImplementation)
 676						((Parameter) p).Warning_UselessOptionalParameter (Report);
 677				}
 678			}
 679		}
 680
 681		protected override void DoMemberTypeDependentChecks ()
 682		{
 683			base.DoMemberTypeDependentChecks ();
 684
 685			if (MemberType.IsStatic) {
 686				Error_StaticReturnType ();
 687			}
 688		}
 689
 690		public override void Emit ()
 691		{
 692			if ((ModFlags & Modifiers.COMPILER_GENERATED) != 0 && !Parent.IsCompilerGenerated)
 693				Module.PredefinedAttributes.CompilerGenerated.EmitAttribute (MethodBuilder);
 694			if ((ModFlags & Modifiers.DEBUGGER_HIDDEN) != 0)
 695				Module.PredefinedAttributes.DebuggerHidden.EmitAttribute (MethodBuilder);
 696			if ((ModFlags & Modifiers.DEBUGGER_STEP_THROUGH) != 0)
 697				Module.PredefinedAttributes.DebuggerStepThrough.EmitAttribute (MethodBuilder);
 698
 699			if (ReturnType.BuiltinType == BuiltinTypeSpec.Type.Dynamic) {
 700				return_attributes = new ReturnParameter (this, MethodBuilder, Location);
 701				Module.PredefinedAttributes.Dynamic.EmitAttribute (return_attributes.Builder);
 702			} else if (ReturnType.HasDynamicElement) {
 703				return_attributes = new ReturnParameter (this, MethodBuilder, Location);
 704				Module.PredefinedAttributes.Dynamic.EmitAttribute (return_attributes.Builder, ReturnType, Location);
 705			}
 706
 707			if (OptAttributes != null)
 708				OptAttributes.Emit ();
 709
 710			if (declarative_security != null) {
 711				foreach (var de in declarative_security) {
 712#if STATIC
 713					MethodBuilder.__AddDeclarativeSecurity (de);
 714#else
 715					MethodBuilder.AddDeclarativeSecurity (de.Key, de.Value);
 716#endif
 717				}
 718			}
 719
 720			if (type_expr != null)
 721				ConstraintChecker.Check (this, member_type, type_expr.Location);
 722
 723			base.Emit ();
 724
 725			if (MethodData != null)
 726				MethodData.Emit (Parent);
 727
 728			if (block != null && block.StateMachine is AsyncTaskStorey) {
 729				var psm = Module.PredefinedAttributes.AsyncStateMachine;
 730				psm.EmitAttribute (MethodBuilder, block.StateMachine);
 731			}
 732
 733			if ((ModFlags & Modifiers.PARTIAL) == 0)
 734				Block = null;
 735		}
 736
 737		protected void Error_ConditionalAttributeIsNotValid ()
 738		{
 739			Report.Error (577, Location,
 740				"Conditional not valid on `{0}' because it is a constructor, destructor, operator or explicit interface implementation",
 741				GetSignatureForError ());
 742		}
 743
 744		public bool IsPartialDefinition {
 745			get {
 746				return (ModFlags & Modifiers.PARTIAL) != 0 && Block == null;
 747			}
 748		}
 749
 750		public bool IsPartialImplementation {
 751			get {
 752				return (ModFlags & Modifiers.PARTIAL) != 0 && Block != null;
 753			}
 754		}
 755
 756		public override string[] ValidAttributeTargets {
 757			get {
 758				return attribute_targets;
 759			}
 760		}
 761
 762		#region IMethodData Members
 763
 764		bool IMethodData.IsAccessor {
 765			get {
 766				return false;
 767			}
 768		}
 769
 770		public TypeSpec ReturnType {
 771			get {
 772				return MemberType;
 773			}
 774		}
 775
 776		public MemberName MethodName {
 777			get {
 778				return MemberName;
 779			}
 780		}
 781
 782		/// <summary>
 783		/// Returns true if method has conditional attribute and the conditions is not defined (method is excluded).
 784		/// </summary>
 785		public override string[] ConditionalConditions ()
 786		{
 787			if ((caching_flags & (Flags.Excluded_Undetected | Flags.Excluded)) == 0)
 788				return null;
 789
 790			if ((ModFlags & Modifiers.PARTIAL) != 0 && (caching_flags & Flags.Excluded) != 0)
 791				return new string [0];
 792
 793			caching_flags &= ~Flags.Excluded_Undetected;
 794			string[] conditions;
 795
 796			if (base_method == null) {
 797				if (OptAttributes == null)
 798					return null;
 799
 800				Attribute[] attrs = OptAttributes.SearchMulti (Module.PredefinedAttributes.Conditional);
 801				if (attrs == null)
 802					return null;
 803
 804				conditions = new string[attrs.Length];
 805				for (int i = 0; i < conditions.Length; ++i)
 806					conditions[i] = attrs[i].GetConditionalAttributeValue ();
 807			} else {
 808				conditions = base_method.MemberDefinition.ConditionalConditions();
 809			}
 810
 811			if (conditions != null)
 812				caching_flags |= Flags.Excluded;
 813
 814			return conditions;
 815		}
 816
 817		#endregion
 818
 819		public virtual void PrepareEmit ()
 820		{
 821			var mb = MethodData.DefineMethodBuilder (Parent);
 822
 823			if (CurrentTypeParameters != null) {
 824				string[] gnames = new string[CurrentTypeParameters.Count];
 825				for (int i = 0; i < gnames.Length; ++i) {
 826					gnames[i] = CurrentTypeParameters[i].Name;
 827				}
 828
 829				var gen_params = MethodBuilder.DefineGenericParameters (gnames);
 830
 831				for (int i = 0; i < CurrentTypeParameters.Count; ++i) {
 832					var tp = CurrentTypeParameters[i];
 833
 834					tp.Define (gen_params[i]);
 835				}
 836			}
 837
 838			//
 839			// Generic method has been already defined to resolve method parameters
 840			// correctly when they use type parameters
 841			//
 842			mb.SetParameters (parameters.GetMetaInfo ());
 843			mb.SetReturnType (ReturnType.GetMetaInfo ());
 844		}
 845
 846		public override void WriteDebugSymbol (MonoSymbolFile file)
 847		{
 848			if (MethodData != null && !IsPartialDefinition)
 849				MethodData.WriteDebugSymbol (file);
 850		}
 851	}
 852
 853	public class Method : MethodOrOperator, IGenericMethodDefinition
 854	{
 855		Method partialMethodImplementation;
 856
 857		public Method (TypeDefinition parent, FullNamedExpression return_type, Modifiers mod, MemberName name, ParametersCompiled parameters, Attributes attrs)
 858			: base (parent, return_type, mod,
 859				parent.PartialContainer.Kind == MemberKind.Interface ? AllowedModifiersInterface :
 860				parent.PartialContainer.Kind == MemberKind.Struct ? AllowedModifiersStruct | Modifiers.ASYNC :
 861				AllowedModifiersClass | Modifiers.ASYNC,
 862				name, attrs, parameters)
 863		{
 864		}
 865
 866		protected Method (TypeDefinition parent, FullNamedExpression return_type, Modifiers mod, Modifiers amod,
 867					MemberName name, ParametersCompiled parameters, Attributes attrs)
 868			: base (parent, return_type, mod, amod, name, attrs, parameters)
 869		{
 870		}
 871
 872		#region Properties
 873
 874		public override TypeParameters CurrentTypeParameters {
 875			get {
 876				return MemberName.TypeParameters;
 877			}
 878		}
 879
 880		public TypeParameterSpec[] TypeParameters {
 881			get {
 882				return CurrentTypeParameters.Types;
 883			}
 884		}
 885
 886		public int TypeParametersCount {
 887			get {
 888				return CurrentTypeParameters == null ? 0 : CurrentTypeParameters.Count;
 889			}
 890		}
 891
 892		#endregion
 893
 894		public override void Accept (StructuralVisitor visitor)
 895		{
 896			visitor.Visit (this);
 897		}
 898
 899		public static Method Create (TypeDefinition parent, FullNamedExpression returnType, Modifiers mod,
 900				   MemberName name, ParametersCompiled parameters, Attributes attrs)
 901		{
 902			var m = new Method (parent, returnType, mod, name, parameters, attrs);
 903
 904			if ((mod & Modifiers.PARTIAL) != 0) {
 905				const Modifiers invalid_partial_mod = Modifiers.AccessibilityMask | Modifiers.ABSTRACT | Modifiers.EXTERN |
 906					Modifiers.NEW | Modifiers.OVERRIDE | Modifiers.SEALED | Modifiers.VIRTUAL;
 907
 908				if ((mod & invalid_partial_mod) != 0) {
 909					m.Report.Error (750, m.Location,
 910						"A partial method cannot define access modifier or any of abstract, extern, new, override, sealed, or virtual modifiers");
 911					mod &= ~invalid_partial_mod;
 912				}
 913
 914				if ((parent.ModFlags & Modifiers.PARTIAL) == 0) {
 915					m.Report.Error (751, m.Location, 
 916						"A partial method must be declared within a partial class or partial struct");
 917				}
 918			}
 919
 920			if ((mod & Modifiers.STATIC) == 0 && parameters.HasExtensionMethodType) {
 921				m.Report.Error (1105, m.Location, "`{0}': Extension methods must be declared static",
 922					m.GetSignatureForError ());
 923			}
 924
 925
 926			return m;
 927		}
 928
 929		public override string GetSignatureForError()
 930		{
 931			return base.GetSignatureForError () + parameters.GetSignatureForError ();
 932		}
 933
 934		void Error_DuplicateEntryPoint (Method b)
 935		{
 936			Report.Error (17, b.Location,
 937				"Program `{0}' has more than one entry point defined: `{1}'",
 938				b.Module.Builder.ScopeName, b.GetSignatureForError ());
 939		}
 940
 941		bool IsEntryPoint ()
 942		{
 943			if (ReturnType.Kind != MemberKind.Void && ReturnType.BuiltinType != BuiltinTypeSpec.Type.Int)
 944				return false;
 945
 946			if (parameters.IsEmpty)
 947				return true;
 948
 949			if (parameters.Count > 1)
 950				return false;
 951
 952			var ac = parameters.Types [0] as ArrayContainer;
 953			return ac != null && ac.Rank == 1 && ac.Element.BuiltinType == BuiltinTypeSpec.Type.String &&
 954					(parameters[0].ModFlags & Parameter.Modifier.RefOutMask) == 0;
 955		}
 956
 957		public override FullNamedExpression LookupNamespaceOrType (string name, int arity, LookupMode mode, Location loc)
 958		{
 959			if (arity == 0) {
 960				var tp = CurrentTypeParameters;
 961				if (tp != null) {
 962					TypeParameter t = tp.Find (name);
 963					if (t != null)
 964						return new TypeParameterExpr (t, loc);
 965				}
 966			}
 967
 968			return base.LookupNamespaceOrType (name, arity, mode, loc);
 969		}
 970
 971		public override void ApplyAttributeBuilder (Attribute a, MethodSpec ctor, byte[] cdata, PredefinedAttributes pa)
 972		{
 973			if (a.Type == pa.Conditional) {
 974				if (IsExplicitImpl) {
 975					Error_ConditionalAttributeIsNotValid ();
 976					return;
 977				}
 978
 979				if ((ModFlags & Modifiers.OVERRIDE) != 0) {
 980					Report.Error (243, Location, "Conditional not valid on `{0}' because it is an override method", GetSignatureForError ());
 981					return;
 982				}
 983
 984				if (ReturnType.Kind != MemberKind.Void) {
 985					Report.Error (578, Location, "Conditional not valid on `{0}' because its return type is not void", GetSignatureForError ());
 986					return;
 987				}
 988
 989				if (IsInterface) {
 990					Report.Error (582, Location, "Conditional not valid on interface members");
 991					return;
 992				}
 993
 994				if (MethodData.implementing != null) {
 995					Report.SymbolRelatedToPreviousError (MethodData.implementing.DeclaringType);
 996					Report.Error (629, Location, "Conditional member `{0}' cannot implement interface member `{1}'",
 997						GetSignatureForError (), TypeManager.CSharpSignature (MethodData.implementing));
 998					return;
 999				}
1000
1001				for (int i = 0; i < parameters.Count; ++i) {
1002					if ((parameters.FixedParameters [i].ModFlags & Parameter.Modifier.OUT) != 0) {
1003						Report.Error (685, Location, "Conditional method `{0}' cannot have an out parameter", GetSignatureForError ());
1004						return;
1005					}
1006				}
1007			}
1008
1009			if (a.Type == pa.Extension) {
1010				a.Error_MisusedExtensionAttribute ();
1011				return;
1012			}
1013
1014			base.ApplyAttributeBuilder (a, ctor, cdata, pa);
1015		}
1016
1017		void CreateTypeParameters ()
1018		{
1019			var tparams = MemberName.TypeParameters;
1020			var parent_tparams = Parent.TypeParametersAll;
1021
1022			for (int i = 0; i < MemberName.Arity; i++) {
1023				string type_argument_name = tparams[i].MemberName.Name;
1024
1025				if (block == null) {
1026					int idx = parameters.GetParameterIndexByName (type_argument_name);
1027					if (idx >= 0) {
1028						var b = block;
1029						if (b == null)
1030							b = new ToplevelBlock (Compiler, Location);
1031
1032						b.Error_AlreadyDeclaredTypeParameter (type_argument_name, parameters[i].Location);
1033					}
1034				} else {
1035					INamedBlockVariable variable = null;
1036					block.GetLocalName (type_argument_name, block, ref variable);
1037					if (variable != null)
1038						variable.Block.Error_AlreadyDeclaredTypeParameter (type_argument_name, variable.Location);
1039				}
1040
1041				if (parent_tparams != null) {
1042					var tp = parent_tparams.Find (type_argument_name);
1043					if (tp != null) {
1044						tparams[i].WarningParentNameConflict (tp);
1045					}
1046				}
1047			}
1048
1049			tparams.Create (null, 0, Parent);
1050		}
1051
1052		protected virtual void DefineTypeParameters ()
1053		{
1054			var tparams = CurrentTypeParameters;
1055
1056			TypeParameterSpec[] base_tparams = null;
1057			TypeParameterSpec[] base_decl_tparams = TypeParameterSpec.EmptyTypes;
1058			TypeSpec[] base_targs = TypeSpec.EmptyTypes;
1059			if (((ModFlags & Modifiers.OVERRIDE) != 0 || IsExplicitImpl)) {
1060				MethodSpec base_override = base_method ?? MethodData.implementing;
1061
1062				if (base_override != null) {
1063					base_tparams = base_override.GenericDefinition.TypeParameters;
1064
1065					if (base_override.DeclaringType.IsGeneric) {
1066						base_decl_tparams = base_override.DeclaringType.MemberDefinition.TypeParameters;
1067
1068						if (base_method != null) {
1069							var base_type_parent = CurrentType;
1070							while (base_type_parent.BaseType != base_override.DeclaringType) {
1071								base_type_parent = base_type_parent.BaseType;
1072							}
1073
1074							base_targs = base_type_parent.BaseType.TypeArguments;
1075						} else {
1076							foreach (var iface in Parent.CurrentType.Interfaces) {
1077								if (iface == base_override.DeclaringType) {
1078									base_targs = iface.TypeArguments;
1079									break;
1080								}
1081							}
1082						}
1083					}
1084
1085					if (base_override.IsGeneric) {
1086						ObsoleteAttribute oa;
1087						foreach (var base_tp in base_tparams) {
1088							oa = base_tp.BaseType.GetAttributeObsolete ();
1089							if (oa != null) {
1090								AttributeTester.Report_ObsoleteMessage (oa, base_tp.BaseType.GetSignatureForError (), Location, Report);
1091							}
1092
1093							if (base_tp.InterfacesDefined != null) {
1094								foreach (var iface in base_tp.InterfacesDefined) {
1095									oa = iface.GetAttributeObsolete ();
1096									if (oa != null) {
1097										AttributeTester.Report_ObsoleteMessage (oa, iface.GetSignatureForError (), Location, Report);
1098									}
1099								}
1100							}
1101						}
1102
1103						if (base_decl_tparams.Length != 0) {
1104							base_decl_tparams = base_decl_tparams.Concat (base_tparams).ToArray ();
1105							base_targs = base_targs.Concat (tparams.Types).ToArray ();
1106						} else {
1107							base_decl_tparams = base_tparams;
1108							base_targs = tparams.Types;
1109						}
1110					}
1111				}
1112			}
1113
1114			for (int i = 0; i < tparams.Count; ++i) {
1115				var tp = tparams [i];
1116
1117				if (base_tparams == null) {
1118					tp.ResolveConstraints (this);
1119					continue;
1120				}
1121
1122				//
1123				// Copy base constraints for override/explicit methods
1124				//
1125				var base_tparam = base_tparams [i];
1126				var local_tparam = tp.Type;
1127				local_tparam.SpecialConstraint = base_tparam.SpecialConstraint;
1128
1129				var inflator = new TypeParameterInflator (this, CurrentType, base_decl_tparams, base_targs);
1130				base_tparam.InflateConstraints (inflator, local_tparam);
1131
1132				//
1133				// Check all type argument constraints for possible collision or unification
1134				// introduced by inflating inherited constraints in this context
1135				//
1136				// Conflict example:
1137				//
1138				// class A<T> { virtual void Foo<U> () where U : class, T {} }
1139				// class B : A<int> { override void Foo<U> {} }
1140				//
1141				var local_tparam_targs = local_tparam.TypeArguments;
1142				if (local_tparam_targs != null) {
1143					for (int ii = 0; ii < local_tparam_targs.Length; ++ii) {
1144						var ta = local_tparam_targs [ii];
1145						if (!ta.IsClass && !ta.IsStruct)
1146							continue;
1147
1148						TypeSpec[] unique_tparams = null;
1149						for (int iii = ii + 1; iii < local_tparam_targs.Length; ++iii) {
1150							//
1151							// Remove any identical or unified constraint types
1152							//
1153							var tparam_checked = local_tparam_targs [iii];
1154							if (TypeSpecComparer.IsEqual (ta, tparam_checked) || TypeSpec.IsBaseClass (ta, tparam_checked, false)) {
1155								unique_tparams = new TypeSpec[local_tparam_targs.Length - 1];
1156								Array.Copy (local_tparam_targs, 0, unique_tparams, 0, iii);
1157								Array.Copy (local_tparam_targs, iii + 1, unique_tparams, iii, local_tparam_targs.Length - iii - 1);
1158							} else if (!TypeSpec.IsBaseClass (tparam_checked, ta, false)) {
1159								Constraints.Error_ConflictingConstraints (this, local_tparam, ta, tparam_checked, Location);
1160							}
1161						}
1162
1163						if (unique_tparams != null) {
1164							local_tparam_targs = unique_tparams;
1165							local_tparam.TypeArguments = local_tparam_targs;
1166							continue;
1167						}
1168
1169						Constraints.CheckConflictingInheritedConstraint (local_tparam, ta, this, Location);
1170					}
1171				}
1172			}
1173
1174			if (base_tparams == null && MethodData != null && MethodData.implementing != null) {
1175				CheckImplementingMethodConstraints (Parent, spec, MethodData.implementing);
1176			}
1177		}
1178
1179		public static bool CheckImplementingMethodConstraints (TypeContainer container, MethodSpec method, MethodSpec baseMethod)
1180		{
1181			var tparams = method.Constraints;
1182			var base_tparams = baseMethod.Constraints;
1183			for (int i = 0; i < tparams.Length; ++i) {
1184				if (!tparams[i].HasSameConstraintsImplementation (base_tparams[i])) {
1185					container.Compiler.Report.SymbolRelatedToPreviousError (method);
1186					container.Compiler.Report.SymbolRelatedToPreviousError (baseMethod);
1187
1188					// Using container location because the interface can be implemented
1189					// by base class
1190					var tp = (tparams [i].MemberDefinition as MemberCore) ?? container;
1191					container.Compiler.Report.Error (425, tp.Location,
1192						"The constraints for type parameter `{0}' of method `{1}' must match the constraints for type parameter `{2}' of interface method `{3}'. Consider using an explicit interface implementation instead",
1193						tparams[i].GetSignatureForError (), method.GetSignatureForError (),
1194						base_tparams[i].GetSignatureForError (), baseMethod.GetSignatureForError ());
1195 
1196					return false;
1197				}
1198			}
1199
1200			return true;
1201		}
1202
1203		//
1204		// Creates the type
1205		//
1206		public override bool Define ()
1207		{
1208			if (!base.Define ())
1209				return false;
1210
1211			if (member_type.Kind == MemberKind.Void && parameters.IsEmpty && MemberName.Arity == 0 && MemberName.Name == Destructor.MetadataName) {
1212				Report.Warning (465, 1, Location,
1213					"Introducing `Finalize' method can interfere with destructor invocation. Did you intend to declare a destructor?");
1214			}
1215
1216			if (Compiler.Settings.StdLib && ReturnType.IsSpecialRuntimeType) {
1217				Error1599 (Location, ReturnType, Report);
1218				return false;
1219			}
1220
1221			if (CurrentTypeParameters == null) {
1222				if (base_method != null && !IsExplicitImpl) {
1223					if (parameters.Count == 1 && ParameterTypes[0].BuiltinType == BuiltinTypeSpec.Type.Object && MemberName.Name == "Equals")
1224						Parent.PartialContainer.Mark_HasEquals ();
1225					else if (parameters.IsEmpty && MemberName.Name == "GetHashCode")
1226						Parent.PartialContainer.Mark_HasGetHashCode ();
1227				}
1228					
1229			} else {
1230				DefineTypeParameters ();
1231			}
1232
1233			if (block != null) {
1234				if (block.IsIterator) {
1235					//
1236					// Current method is turned into automatically generated
1237					// wrapper which creates an instance of iterator
1238					//
1239					Iterator.CreateIterator (this, Parent.PartialContainer, ModFlags);
1240					ModFlags |= Modifiers.DEBUGGER_HIDDEN;
1241				}
1242
1243				if ((ModFlags & Modifiers.ASYNC) != 0) {
1244					if (ReturnType.Kind != MemberKind.Void &&
1245						ReturnType != Module.PredefinedTypes.Task.TypeSpec &&
1246						!ReturnType.IsGenericTask) {
1247						Report.Error (1983, Location, "The return type of an async method must be void, Task, or Task<T>");
1248					}
1249
1250					block = (ToplevelBlock) block.ConvertToAsyncTask (this, Parent.PartialContainer, parameters, ReturnType, null, Location);
1251					ModFlags |= Modifiers.DEBUGGER_STEP_THROUGH;
1252				}
1253
1254				if (Compiler.Settings.WriteMetadataOnly)
1255					block = null;
1256			}
1257
1258			if ((ModFlags & Modifiers.STATIC) == 0)
1259				return true;
1260
1261			if (parameters.HasExtensionMethodType) {
1262				if (Parent.PartialContainer.IsStatic && !Parent.IsGenericOrParentIsGeneric) {
1263					if (!Parent.IsTopLevel)
1264						Report.Error (1109, Location, "`{0}': Extension methods cannot be defined in a nested class",
1265							GetSignatureForError ());
1266
1267					PredefinedAttribute pa = Module.PredefinedAttributes.Extension;
1268					if (!pa.IsDefined) {
1269						Report.Error (1110, Location,
1270							"`{0}': Extension methods require `System.Runtime.CompilerServices.ExtensionAttribute' type to be available. Are you missing an assembly reference?",
1271							GetSignatureForError ());
1272					}
1273
1274					ModFlags |= Modifiers.METHOD_EXTENSION;
1275					Parent.PartialContainer.ModFlags |= Modifiers.METHOD_EXTENSION;
1276					Spec.DeclaringType.SetExtensionMethodContainer ();
1277					Parent.Module.HasExtensionMethod = true;
1278				} else {
1279					Report.Error (1106, Location, "`{0}': Extension methods must be defined in a non-generic static class",
1280						GetSignatureForError ());
1281				}
1282			}
1283
1284			//
1285			// This is used to track the Entry Point,
1286			//
1287			var settings = Compiler.Settings;
1288			if (settings.NeedsEntryPoint && MemberName.Name == "Main" && !IsPartialDefinition && (settings.MainClass == null || settings.MainClass == Parent.TypeBuilder.FullName)) {
1289				if (IsEntryPoint ()) {
1290					if (Parent.DeclaringAssembly.EntryPoint == null) {
1291						if (Parent.IsGenericOrParentIsGeneric || MemberName.IsGeneric) {
1292							Report.Warning (402, 4, Location, "`{0}': an entry point cannot be generic or in a generic type",
1293								GetSignatureForError ());
1294						} else if ((ModFlags & Modifiers.ASYNC) != 0) {
1295							Report.Error (4009, Location, "`{0}': an entry point cannot be async method",
1296								GetSignatureForError ());
1297						} else {
1298							SetIsUsed ();
1299							Parent.DeclaringAssembly.EntryPoint = this;
1300						}
1301					} else {
1302						Error_DuplicateEntryPoint (Parent.DeclaringAssembly.EntryPoint);
1303						Error_DuplicateEntryPoint (this);
1304					}
1305				} else {
1306					Report.Warning (28, 4, Location, "`{0}' has the wrong signature to be an entry point",
1307						GetSignatureForError ());
1308				}
1309			}
1310
1311			return true;
1312		}
1313
1314		public override void PrepareEmit ()
1315		{
1316			if (IsPartialDefinition) {
1317				//
1318				// Use partial method implementation builder for partial method declaration attributes
1319				//
1320				if (partialMethodImplementation != null) {
1321					MethodData = partialMethodImplementation.MethodData;
1322				}
1323
1324				return;
1325			}
1326
1327			base.PrepareEmit ();
1328		}
1329
1330		//
1331		// Emits the code
1332		// 
1333		public override void Emit ()
1334		{
1335			try {
1336				if (IsPartialDefinition) {
1337					if (partialMethodImplementation != null && CurrentTypeParameters != null) {
1338						CurrentTypeParameters.CheckPartialConstraints (partialMethodImplementation);
1339
1340						var otp = partialMethodImplementation.CurrentTypeParameters;
1341						for (int i = 0; i < CurrentTypeParameters.Count; ++i) {
1342							var tp = CurrentTypeParameters [i];
1343							tp.Define (otp[i]);
1344						}
1345					}
1346
1347					return;
1348				}
1349				
1350				if ((ModFlags & Modifiers.PARTIAL) != 0 && (caching_flags & Flags.PartialDefinitionExists) == 0) {
1351					Report.Error (759, Location, "A partial method `{0}' implementation is missing a partial method declaration",
1352						GetSignatureForError ());
1353				}
1354
1355				if (CurrentTypeParameters != null) {
1356					for (int i = 0; i < CurrentTypeParameters.Count; ++i) {
1357						var tp = CurrentTypeParameters [i];
1358
1359						tp.CheckGenericConstraints (false);
1360						tp.Emit ();
1361					}
1362				}
1363
1364				if ((ModFlags & Modifiers.METHOD_EXTENSION) != 0)
1365					Module.PredefinedAttributes.Extension.EmitAttribute (MethodBuilder);
1366
1367				base.Emit ();
1368			} catch (Exception e) {
1369				throw new InternalErrorException (this, e);
1370			}
1371		}
1372
1373		public override bool EnableOverloadChecks (MemberCore overload)
1374		{
1375			if (overload is Indexer)
1376				return false;
1377
1378			return base.EnableOverloadChecks (overload);
1379		}
1380
1381		public static void Error1599 (Location loc, TypeSpec t, Report Report)
1382		{
1383			Report.Error (1599, loc, "Method or delegate cannot return type `{0}'", t.GetSignatureForError ());
1384		}
1385
1386		protected override bool ResolveMemberType ()
1387		{
1388			if (CurrentTypeParameters != null) {
1389				CreateTypeParameters ();
1390			}
1391
1392			return base.ResolveMemberType ();
1393		}
1394
1395		public void SetPartialDefinition (Method methodDefinition)
1396		{
1397			caching_flags |= Flags.PartialDefinitionExists;
1398			methodDefinition.partialMethodImplementation = this;
1399
1400			// Ensure we are always using method declaration parameters
1401			for (int i = 0; i < methodDefinition.parameters.Count; ++i ) {
1402				var md_p = methodDefinition.parameters [i];
1403				var p = parameters [i];
1404				p.Name = md_p.Name;
1405				p.DefaultValue = md_p.DefaultValue;
1406				if (md_p.OptAttributes != null) {
1407					if (p.OptAttributes == null) {
1408						p.OptAttributes = md_p.OptAttributes;
1409					} else {
1410						p.OptAttributes.Attrs.AddRange (md_p.OptAttributes.Attrs);
1411					}
1412				}
1413			}
1414
1415			if (methodDefinition.attributes != null) {
1416				if (attributes == null) {
1417					attributes = methodDefinition.attributes;
1418				} else {
1419					attributes.Attrs.AddRange (methodDefinition.attributes.Attrs);
1420				}
1421			}
1422
1423			if (CurrentTypeParameters != null) {
1424				for (int i = 0; i < CurrentTypeParameters.Count; ++i) {
1425					var tp_other = methodDefinition.CurrentTypeParameters [i];
1426					if (tp_other.OptAttributes == null)
1427						continue;
1428
1429					var tp = CurrentTypeParameters [i];
1430					if (tp.OptAttributes == null) {
1431						tp.OptAttributes = tp_other.OptAttributes;
1432					} else {
1433						tp.OptAttributes.Attrs.AddRange (tp.OptAttributes.Attrs);
1434					}
1435				}
1436			}
1437		}
1438	}
1439
1440	public abstract class ConstructorInitializer : ExpressionStatement
1441	{
1442		Arguments argument_list;
1443		MethodSpec base_ctor;
1444
1445		protected ConstructorInitializer (Arguments argument_list, Location loc)
1446		{
1447			this.argument_list = argument_list;
1448			this.loc = loc;
1449		}
1450
1451		public Arguments Arguments {
1452			get {
1453				return argument_list;
1454			}
1455		}
1456
1457		public override bool ContainsEmitWithAwait ()
1458		{
1459			throw new NotSupportedException ();
1460		}
1461
1462		public override Expression CreateExpressionTree (ResolveContext ec)
1463		{
1464			throw new NotSupportedException ("ET");
1465		}
1466
1467		protected override Expression DoResolve (ResolveContext ec)
1468		{
1469			eclass = ExprClass.Value;
1470
1471			// FIXME: Hack
1472			var caller_builder = (Constructor) ec.MemberContext;
1473
1474			//
1475			// Spec mandates that constructor initializer will not have `this' access
1476			//
1477			using (ec.Set (ResolveContext.Options.BaseInitializer)) {
1478				if (argument_list != null) {
1479					bool dynamic;
1480					argument_list.Resolve (ec, out dynamic);
1481
1482					if (dynamic) {
1483						ec.Report.Error (1975, loc,
1484							"The constructor call cannot be dynamically dispatched within constructor initializer");
1485
1486						return null;
1487					}
1488				}
1489
1490				type = ec.CurrentType;
1491				if (this is ConstructorBaseInitializer) {
1492					if (ec.CurrentType.BaseType == null)
1493						return this;
1494
1495					type = ec.CurrentType.BaseType;
1496					if (ec.CurrentType.IsStruct) {
1497						ec.Report.Error (522, loc,
1498							"`{0}': Struct constructors cannot call base constructors", caller_builder.GetSignatureForError ());
1499						return this;
1500					}
1501				} else {
1502					//
1503					// It is legal to have "this" initializers that take no arguments
1504					// in structs
1505					//
1506					// struct D { public D (int a) : this () {}
1507					//
1508					if (ec.CurrentType.IsStruct && argument_list == null)
1509						return this;
1510				}
1511
1512				base_ctor = ConstructorLookup (ec, type, ref argument_list, loc);
1513			}
1514	
1515			if (base_ctor != null && base_ctor.MemberDefinition == caller_builder.Spec.MemberDefinition) {
1516				ec.Report.Error (516, loc, "Constructor `{0}' cannot call itself",
1517					caller_builder.GetSignatureForError ());
1518			}
1519
1520			return this;
1521		}
1522
1523		public override void Emit (EmitContext ec)
1524		{
1525			//
1526			// It can be null for struct initializers or System.Object
1527			//
1528			if (base_ctor == null) {
1529				if (type == ec.BuiltinTypes.Object)
1530					return;
1531
1532				ec.Emit (OpCodes.Ldarg_0);
1533				ec.Emit (OpCodes.Initobj, type);
1534				return;
1535			}
1536			
1537			var call = new CallEmitter ();
1538			call.InstanceExpression = new CompilerGeneratedThis (type, loc); 
1539			call.EmitPredefined (ec, base_ctor, argument_list, false);
1540		}
1541
1542		public override void EmitStatement (EmitContext ec)
1543		{
1544			Emit (ec);
1545		}
1546
1547		public override void FlowAnalysis (FlowAnalysisContext fc)
1548		{
1549			if (argument_list != null)
1550				argument_list.FlowAnalysis (fc);
1551		}
1552	}
1553
1554	public class ConstructorBaseInitializer : ConstructorInitializer {
1555		public ConstructorBaseInitializer (Arguments argument_list, Location l) :
1556			base (argument_list, l)
1557		{
1558		}
1559	}
1560
1561	class GeneratedBaseInitializer: ConstructorBaseInitializer {
1562		public GeneratedBaseInitializer (Location loc, Arguments arguments)
1563			: base (arguments, loc)
1564		{
1565		}
1566	}
1567
1568	public class ConstructorThisInitializer : ConstructorInitializer {
1569		public ConstructorThisInitializer (Arguments argument_list, Location l) :
1570			base (argument_list, l)
1571		{
1572		}
1573	}
1574	
1575	public class Constructor : MethodCore, IMethodData, IMethodDefinition
1576	{
1577		public ConstructorBuilder ConstructorBuilder;
1578		public ConstructorInitializer Initializer;
1579		SecurityType declarative_security;
1580		bool has_compliant_args;
1581		SourceMethodBuilder debug_builder;
1582
1583		// <summary>
1584		//   Modifiers allowed for a constructor.
1585		// </summary>
1586		public const Modifiers AllowedModifiers =
1587			Modifiers.PUBLIC |
1588			Modifiers.PROTECTED |
1589			Modifiers.INTERNAL |
1590			Modifiers.STATIC |
1591			Modifiers.UNSAFE |
1592			Modifiers.EXTERN |		
1593			Modifiers.PRIVATE;
1594
1595		static readonly string[] attribute_targets = new string [] { "method" };
1596
1597		public static readonly string ConstructorName = ".ctor";
1598		public static readonly string TypeConstructorName = ".cctor";
1599
1600		public Constructor (TypeDefinition parent, string name, Modifiers mod, Attributes attrs, ParametersCompiled args, Location loc)
1601			: base (parent, null, mod, AllowedModifiers, new MemberName (name, loc), attrs, args)
1602		{
1603		}
1604
1605		public bool HasCompliantArgs {
1606			get {
1607				return has_compliant_args;
1608			}
1609		}
1610
1611		public override AttributeTargets AttributeTargets {
1612			get {
1613				return AttributeTargets.Constructor;
1614			}
1615		}
1616
1617		bool IMethodData.IsAccessor {
1618		    get {
1619		        return false;
1620		    }
1621		}
1622
1623		public bool IsPrimaryConstructor { get; set; }
1624		
1625		MethodBase IMethodDefinition.Metadata {
1626			get {
1627				return ConstructorBuilder;
1628			}
1629		}
1630
1631		//
1632		// Returns true if this is a default constructor
1633		//
1634		public bool IsDefault ()
1635		{
1636			if ((ModFlags & Modifiers.STATIC) != 0)
1637				return parameters.IsEmpty;
1638
1639			return parameters.IsEmpty &&
1640					(Initializer is ConstructorBaseInitializer) &&
1641					(Initializer.Arguments == null);
1642		}
1643
1644		public override void Accept (StructuralVisitor visitor)
1645		{
1646			visitor.Visit (this);
1647		}
1648
1649		public override void ApplyAttributeBuilder (Attribute a, MethodSpec ctor, byte[] cdata, PredefinedAttributes pa)
1650		{
1651			if (a.IsValidSecurityAttribute ()) {
1652				a.ExtractSecurityPermissionSet (ctor, ref declarative_security);
1653				return;
1654			}
1655
1656			if (a.Type == pa.MethodImpl) {
1657				is_external_implementation = a.IsInternalCall ();
1658			}
1659
1660			ConstructorBuilder.SetCustomAttribute ((ConstructorInfo) ctor.GetMetaInfo (), cdata);
1661		}
1662
1663		protected override bool CheckBase ()
1664		{
1665			if ((ModFlags & Modifiers.STATIC) != 0) {
1666				if (!parameters.IsEmpty) {
1667					Report.Error (132, Location, "`{0}': The static constructor must be parameterless",
1668						GetSignatureForError ());
1669					return false;
1670				}
1671
1672				if ((caching_flags & Flags.MethodOverloadsExist) != 0)
1673					Parent.MemberCache.CheckExistingMembersOverloads (this, parameters);
1674
1675				// the rest can be ignored
1676				return true;
1677			}
1678
1679			// Check whether arguments were correct.
1680			if (!DefineParameters (parameters))
1681				return false;
1682
1683			if ((caching_flags & Flags.MethodOverloadsExist) != 0)
1684				Parent.MemberCache.CheckExistingMembersOverloads (this, parameters);
1685
1686			if (Parent.PartialContainer.Kind == MemberKind.Struct && parameters.IsEmpty) {
1687				Report.Error (568, Location, 
1688					"Structs cannot contain explicit parameterless constructors");
1689				return false;
1690			}
1691
1692			CheckProtectedModifier ();
1693			
1694			return true;
1695		}
1696		
1697		//
1698		// Creates the ConstructorBuilder
1699		//
1700		public override bool Define ()
1701		{
1702			if (ConstructorBuilder != null)
1703				return true;
1704
1705			if (!CheckAbstractAndExtern (block != null))
1706				return false;
1707			
1708			// Check if arguments were correct.
1709			if (!CheckBase ())
1710				return false;
1711
1712			if (Parent.PrimaryConstructorParameters != null && !IsPrimaryConstructor && !IsStatic) {
1713				if (Parent.Kind == MemberKind.Struct && Initializer is ConstructorThisInitializer && Initializer.Arguments == null) {
1714					Report.Error (8043, Location, "`{0}': Structs with primary constructor cannot specify default constructor initializer",
1715						GetSignatureForError ());
1716				} else if (Initializer == null || Initializer is ConstructorBaseInitializer) {
1717					Report.Error (8037, Location, "`{0}': Instance constructor of type with primary constructor must specify `this' constructor initializer",
1718						GetSignatureForError ());
1719				}
1720			}
1721
1722			var ca = ModifiersExtensions.MethodAttr (ModFlags) | MethodAttributes.RTSpecialName | MethodAttributes.SpecialName;
1723
1724			ConstructorBuilder = Parent.TypeBuilder.DefineConstructor (
1725				ca, CallingConventions,
1726				parameters.GetMetaInfo ());
1727
1728			spec = new MethodSpec (MemberKind.Constructor, Parent.Definition, this, Compiler.BuiltinTypes.Void, parameters, ModFlags);
1729			
1730			Parent.MemberCache.AddMember (spec);
1731			
1732			if (block != null) {
1733				// It's here only to report an error
1734				if (block.IsIterator) {
1735					member_type = Compiler.BuiltinTypes.Void;
1736					Iterator.CreateIterator (this, Parent.PartialContainer, ModFlags);
1737				}
1738
1739				if (Compiler.Settings.WriteMetadataOnly)
1740					block = null;
1741			}
1742
1743			return true;
1744		}
1745
1746		//
1747		// Emits the code
1748		//
1749		public o…