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[mcs.git] / mcs / class.cs

//
// class.cs: Class and Struct handlers
//
// Authors: Miguel de Icaza (miguel@gnu.org)
//          Martin Baulig (martin@ximian.com)
//          Marek Safar (marek.safar@seznam.cz)
//
// Dual licensed under the terms of the MIT X11 or GNU GPL
//
// Copyright 2001, 2002, 2003 Ximian, Inc (http://www.ximian.com)
// Copyright 2004-2008 Novell, Inc
//

using System;
using System.Collections;
using System.Collections.Specialized;
using System.Reflection;
using System.Reflection.Emit;
using System.Runtime.CompilerServices;
using System.Runtime.InteropServices;
using System.Security;
using System.Security.Permissions;
using System.Text;

#if BOOTSTRAP_WITH_OLDLIB || NET_2_1
using XmlElement = System.Object;
#else
using System.Xml;
#endif

using Mono.CompilerServices.SymbolWriter;

namespace Mono.CSharp {

        public enum Kind {
                Root,
                Struct,
                Class,
                Interface,
                Enum,
                Delegate
        }

        /// <summary>
        ///   This is the base class for structs and classes.  
        /// </summary>
        public abstract class TypeContainer : DeclSpace, IMemberContainer {

                public class MemberCoreArrayList: ArrayList
                {
                        /// <summary>
                        ///   Defines the MemberCore objects that are in this array
                        /// </summary>
                        public virtual void DefineContainerMembers ()
                        {
                                foreach (MemberCore mc in this) {
                                        try {
                                                mc.Define ();
                                        } catch (Exception e) {
                                                throw new InternalErrorException (mc, e);
                                        }
                                }
                        }

                        public virtual void Emit ()
                        {
                                foreach (MemberCore mc in this)
                                        mc.Emit ();
                        }
                }

                public class OperatorArrayList: MemberCoreArrayList
                {
                        TypeContainer container;

                        public OperatorArrayList (TypeContainer container)
                        {
                                this.container = container;
                        }

                        //
                        // Checks that some operators come in pairs:
                        //  == and !=
                        // > and <
                        // >= and <=
                        // true and false
                        //
                        // They are matched based on the return type and the argument types
                        //
                        void CheckPairedOperators ()
                        {
                                bool has_equality_or_inequality = false;
                                Operator[] operators = (Operator[]) ToArray (typeof (Operator));
                                bool [] has_pair = new bool [operators.Length];

                                for (int i = 0; i < Count; ++i) {
                                        if (operators [i] == null)
                                                continue;

                                        Operator o_a = operators [i];
                                        Operator.OpType o_type = o_a.OperatorType;
                                        if (o_type == Operator.OpType.Equality || o_type == Operator.OpType.Inequality)
                                                has_equality_or_inequality = true;

                                        Operator.OpType matching_type = o_a.GetMatchingOperator ();
                                        if (matching_type == Operator.OpType.TOP) {
                                                operators [i] = null;
                                                continue;
                                        }
        
                                        for (int ii = 0; ii < Count; ++ii) {
                                                Operator o_b = operators [ii];
                                                if (o_b == null || o_b.OperatorType != matching_type)
                                                        continue;

                                                if (!TypeManager.IsEqual (o_a.ReturnType, o_b.ReturnType))
                                                        continue;

                                                if (!TypeManager.IsEqual (o_a.ParameterTypes, o_b.ParameterTypes))
                                                        continue;

                                                operators [i] = null;

                                                //
                                                // Used to ignore duplicate user conversions
                                                //
                                                has_pair [ii] = true;
                                        }
                                }

                                for (int i = 0; i < Count; ++i) {
                                        if (operators [i] == null || has_pair [i])
                                                continue;

                                        Operator o = operators [i];
                                        Report.Error (216, o.Location,
                                                "The operator `{0}' requires a matching operator `{1}' to also be defined",
                                                o.GetSignatureForError (), Operator.GetName (o.GetMatchingOperator ()));
                                }

                                if (has_equality_or_inequality && Report.WarningLevel > 2) {
                                        if (container.Methods == null || !container.HasEquals)
                                                Report.Warning (660, 2, container.Location, "`{0}' defines operator == or operator != but does not override Object.Equals(object o)", container.GetSignatureForError ());
 
                                        if (container.Methods == null || !container.HasGetHashCode)
                                                Report.Warning (661, 2, container.Location, "`{0}' defines operator == or operator != but does not override Object.GetHashCode()", container.GetSignatureForError ());
                                }
                        }

                        public override void DefineContainerMembers ()
                        {
                                base.DefineContainerMembers ();
                                CheckPairedOperators ();
                        }
                }

                [Flags]
                enum CachedMethods
                {
                        Equals                          = 1,
                        GetHashCode                     = 1 << 1,
                        HasStaticFieldInitializer       = 1 << 2
                }


                // Whether this is a struct, class or interface
                public readonly Kind Kind;

                // Holds a list of classes and structures
                protected ArrayList types;

                MemberCoreArrayList ordered_explicit_member_list;
                MemberCoreArrayList ordered_member_list;

                // Holds the list of properties
                MemberCoreArrayList properties;

                // Holds the list of delegates
                MemberCoreArrayList delegates;
                
                // Holds the list of constructors
                protected MemberCoreArrayList instance_constructors;

                // Holds the list of fields
                protected MemberCoreArrayList fields;

                // Holds a list of fields that have initializers
                protected ArrayList initialized_fields;

                // Holds a list of static fields that have initializers
                protected ArrayList initialized_static_fields;

                // Holds the list of constants
                protected MemberCoreArrayList constants;

                // Holds the methods.
                MemberCoreArrayList methods;

                // Holds the events
                protected MemberCoreArrayList events;

                // Holds the indexers
                ArrayList indexers;

                // Holds the operators
                MemberCoreArrayList operators;

                // Holds the compiler generated classes
                ArrayList compiler_generated;

                //
                // Pointers to the default constructor and the default static constructor
                //
                protected Constructor default_constructor;
                protected Constructor default_static_constructor;

                //
                // Points to the first non-static field added to the container.
                //
                // This is an arbitrary choice.  We are interested in looking at _some_ non-static field,
                // and the first one's as good as any.
                //
                FieldBase first_nonstatic_field = null;

                //
                // This one is computed after we can distinguish interfaces
                // from classes from the arraylist `type_bases' 
                //
                TypeExpr base_type;
                TypeExpr[] iface_exprs;
                Type GenericType;
                GenericTypeParameterBuilder[] nested_gen_params;

                protected ArrayList type_bases;

                protected bool members_defined;
                bool members_defined_ok;

                // The interfaces we implement.
                protected Type[] ifaces;

                // The base member cache and our member cache
                MemberCache base_cache;
                protected MemberCache member_cache;

                public const string DefaultIndexerName = "Item";

                private bool seen_normal_indexers = false;
                private string indexer_name = DefaultIndexerName;
                protected bool requires_delayed_unmanagedtype_check;

                private CachedMethods cached_method;

                ArrayList partial_parts;

                /// <remarks>
                ///  The pending methods that need to be implemented
                //   (interfaces or abstract methods)
                /// </remarks>
                PendingImplementation pending;

                public TypeContainer (NamespaceEntry ns, DeclSpace parent, MemberName name,
                                      Attributes attrs, Kind kind)
                        : base (ns, parent, name, attrs)
                {
                        if (parent != null && parent.NamespaceEntry != ns)
                                throw new InternalErrorException ("A nested type should be in the same NamespaceEntry as its enclosing class");

                        this.Kind = kind;
                        this.PartialContainer = this;
                }

                public bool AddMember (MemberCore symbol)
                {
                        return AddToContainer (symbol, symbol.MemberName.Basename);
                }

                protected virtual bool AddMemberType (DeclSpace ds)
                {
                        return AddToContainer (ds, ds.Basename);
                }

                protected virtual void RemoveMemberType (DeclSpace ds)
                {
                        RemoveFromContainer (ds.Basename);
                }

                public void AddConstant (Const constant)
                {
                        if (!AddMember (constant))
                                return;

                        if (constants == null)
                                constants = new MemberCoreArrayList ();
                        
                        constants.Add (constant);
                }

                public TypeContainer AddTypeContainer (TypeContainer tc)
                {
                        if (!AddMemberType (tc))
                                return tc;

                        if (types == null)
                                types = new MemberCoreArrayList ();
                        types.Add (tc);

                        return tc;
                }

                public virtual TypeContainer AddPartial (TypeContainer next_part)
                {
                        return AddPartial (next_part, next_part.Basename);
                }

                protected TypeContainer AddPartial (TypeContainer next_part, string name)
                {
                        next_part.ModFlags |= Modifiers.PARTIAL;
                        TypeContainer tc = defined_names [name] as TypeContainer;

                        if (tc == null)
                                return AddTypeContainer (next_part);

                        if ((tc.ModFlags & Modifiers.PARTIAL) == 0) {
                                Report.SymbolRelatedToPreviousError (next_part);
                                Error_MissingPartialModifier (tc);
                        }

                        if (tc.Kind != next_part.Kind) {
                                Report.SymbolRelatedToPreviousError (tc);
                                Report.Error (261, next_part.Location,
                                        "Partial declarations of `{0}' must be all classes, all structs or all interfaces",
                                        next_part.GetSignatureForError ());
                        }

                        if ((tc.ModFlags & Modifiers.Accessibility) != (next_part.ModFlags & Modifiers.Accessibility) &&
                                ((tc.ModFlags & Modifiers.DEFAULT_ACCESS_MODIFER) == 0 &&
                                 (next_part.ModFlags & Modifiers.DEFAULT_ACCESS_MODIFER) == 0)) {
                                Report.SymbolRelatedToPreviousError (tc);
                                Report.Error (262, next_part.Location,
                                        "Partial declarations of `{0}' have conflicting accessibility modifiers",
                                        next_part.GetSignatureForError ());
                        }

                        if (tc.partial_parts == null)
                                tc.partial_parts = new ArrayList (1);

                        if ((next_part.ModFlags & Modifiers.DEFAULT_ACCESS_MODIFER) != 0) {
                                tc.ModFlags |= next_part.ModFlags & ~(Modifiers.DEFAULT_ACCESS_MODIFER | Modifiers.Accessibility);
                        } else if ((tc.ModFlags & Modifiers.DEFAULT_ACCESS_MODIFER) != 0) {
                                tc.ModFlags &= ~(Modifiers.DEFAULT_ACCESS_MODIFER | Modifiers.Accessibility);
                                tc.ModFlags |= next_part.ModFlags;
                        } else {
                                tc.ModFlags |= next_part.ModFlags;
                        }

                        if (next_part.attributes != null) {
                                if (tc.attributes == null)
                                        tc.attributes = next_part.attributes;
                                else
                                        tc.attributes.AddAttributes (next_part.attributes.Attrs);
                        }

                        next_part.PartialContainer = tc;
                        tc.partial_parts.Add (next_part);
                        return tc;
                }

                public virtual void RemoveTypeContainer (TypeContainer next_part)
                {
                        if (types != null)
                                types.Remove (next_part);
                        RemoveMemberType (next_part);
                }
                
                public void AddDelegate (Delegate d)
                {
                        if (!AddMemberType (d))
                                return;

                        if (delegates == null)
                                delegates = new MemberCoreArrayList ();

                        delegates.Add (d);
                }

                private void AddMemberToList (MemberCore mc, ArrayList alist, bool isexplicit)
                {
                        if (ordered_explicit_member_list == null)  {
                                ordered_explicit_member_list = new MemberCoreArrayList ();
                                ordered_member_list = new MemberCoreArrayList ();
                        }

                        if (isexplicit) {
                                if (Kind == Kind.Interface) {
                                        Report.Error (541, mc.Location,
                                                "`{0}': explicit interface declaration can only be declared in a class or struct",
                                                mc.GetSignatureForError ());
                                }

                                ordered_explicit_member_list.Add (mc);
                                alist.Insert (0, mc);
                        } else {
                                ordered_member_list.Add (mc);
                                alist.Add (mc);
                        }

                }
                
                public void AddMethod (MethodOrOperator method)
                {
                        if (!AddToContainer (method, method.MemberName.Basename))
                                return;
                        
                        if (methods == null)
                                methods = new MemberCoreArrayList ();

                        if (method.MemberName.Left != null) 
                                AddMemberToList (method, methods, true);
                        else 
                                AddMemberToList (method, methods, false);
                }

                public void AddConstructor (Constructor c)
                {
                        bool is_static = (c.ModFlags & Modifiers.STATIC) != 0;
                        if (!AddToContainer (c, is_static ?
                                ConstructorBuilder.ConstructorName : ConstructorBuilder.TypeConstructorName))
                                return;
                        
                        if (is_static && c.Parameters.IsEmpty){
                                if (default_static_constructor != null) {
                                    Report.SymbolRelatedToPreviousError (default_static_constructor);
                                        Report.Error (111, c.Location,
                                                "A member `{0}' is already defined. Rename this member or use different parameter types",
                                                c.GetSignatureForError ());
                                    return;
                                }

                                default_static_constructor = c;
                        } else {
                                if (c.Parameters.IsEmpty)
                                        default_constructor = c;
                                
                                if (instance_constructors == null)
                                        instance_constructors = new MemberCoreArrayList ();
                                
                                instance_constructors.Add (c);
                        }
                }

                public bool AddField (FieldBase field)
                {
                        if (!AddMember (field))
                                return false;

                        if (fields == null)
                                fields = new MemberCoreArrayList ();

                        fields.Add (field);

                        if ((field.ModFlags & Modifiers.STATIC) != 0)
                                return true;

                        if (first_nonstatic_field == null) {
                                first_nonstatic_field = field;
                                return true;
                        }

                        if (Kind == Kind.Struct && first_nonstatic_field.Parent != field.Parent) {
                                Report.SymbolRelatedToPreviousError (first_nonstatic_field.Parent);
                                Report.Warning (282, 3, field.Location,
                                        "struct instance field `{0}' found in different declaration from instance field `{1}'",
                                        field.GetSignatureForError (), first_nonstatic_field.GetSignatureForError ());
                        }
                        return true;
                }

                public void AddProperty (Property prop)
                {
                        if (!AddMember (prop) || 
                                !AddMember (prop.Get) || !AddMember (prop.Set))
                                return;

                        if (properties == null)
                                properties = new MemberCoreArrayList ();

                        if (prop.MemberName.Left != null)
                                AddMemberToList (prop, properties, true);
                        else 
                                AddMemberToList (prop, properties, false);
                }

                public void AddEvent (Event e)
                {
                        if (!AddMember (e))
                                return;

                        if (e is EventProperty) {
                                if (!AddMember (e.Add))
                                        return;

                                if (!AddMember (e.Remove))
                                        return;
                        }

                        if (events == null)
                                events = new MemberCoreArrayList ();

                        events.Add (e);
                }

                /// <summary>
                /// Indexer has special handling in constrast to other AddXXX because the name can be driven by IndexerNameAttribute
                /// </summary>
                public void AddIndexer (Indexer i)
                {
                        if (indexers == null)
                                indexers = new ArrayList ();

                        if (i.IsExplicitImpl)
                                AddMemberToList (i, indexers, true);
                        else 
                                AddMemberToList (i, indexers, false);
                }

                public void AddOperator (Operator op)
                {
                        if (!AddMember (op))
                                return;

                        if (operators == null)
                                operators = new OperatorArrayList (this);

                        operators.Add (op);
                }

                public void AddCompilerGeneratedClass (CompilerGeneratedClass c)
                {
                        Report.Debug (64, "ADD COMPILER GENERATED CLASS", this, c);

                        if (compiler_generated == null)
                                compiler_generated = new ArrayList ();

                        compiler_generated.Add (c);
                }

                public override void ApplyAttributeBuilder (Attribute a, CustomAttributeBuilder cb, PredefinedAttributes pa)
                {
                        if (a.Type == pa.DefaultMember) {
                                if (Indexers != null) {
                                        Report.Error (646, a.Location, "Cannot specify the `DefaultMember' attribute on type containing an indexer");
                                        return;
                                }
                        }
                        
                        base.ApplyAttributeBuilder (a, cb, pa);
                } 

                public override AttributeTargets AttributeTargets {
                        get {
                                throw new NotSupportedException ();
                        }
                }

                public ArrayList Types {
                        get {
                                return types;
                        }
                }

                public MemberCoreArrayList Methods {
                        get {
                                return methods;
                        }
                }

                public ArrayList Constants {
                        get {
                                return constants;
                        }
                }

                protected Type BaseType {
                        get {
                                return TypeBuilder.BaseType;
                        }
                }

                public ArrayList Fields {
                        get {
                                return fields;
                        }
                }

                public ArrayList InstanceConstructors {
                        get {
                                return instance_constructors;
                        }
                }

                public ArrayList Properties {
                        get {
                                return properties;
                        }
                }

                public ArrayList Events {
                        get {
                                return events;
                        }
                }
                
                public ArrayList Indexers {
                        get {
                                return indexers;
                        }
                }

                public ArrayList Operators {
                        get {
                                return operators;
                        }
                }

                public ArrayList Delegates {
                        get {
                                return delegates;
                        }
                }
                
                protected override TypeAttributes TypeAttr {
                        get {
                                return Modifiers.TypeAttr (ModFlags, IsTopLevel) | base.TypeAttr;
                        }
                }

                public string IndexerName {
                        get {
                                return indexers == null ? DefaultIndexerName : indexer_name;
                        }
                }

                public bool IsComImport {
                        get {
                                if (OptAttributes == null)
                                        return false;

                                return OptAttributes.Contains (PredefinedAttributes.Get.ComImport);
                        }
                }

                public virtual void RegisterFieldForInitialization (MemberCore field, FieldInitializer expression)
                {
                        if ((field.ModFlags & Modifiers.STATIC) != 0){
                                if (initialized_static_fields == null) {
                                        PartialContainer.HasStaticFieldInitializer = true;
                                        initialized_static_fields = new ArrayList (4);
                                }

                                initialized_static_fields.Add (expression);
                        } else {
                                if (initialized_fields == null)
                                        initialized_fields = new ArrayList (4);

                                initialized_fields.Add (expression);
                        }
                }

                public void ResolveFieldInitializers (EmitContext ec)
                {
                        if (partial_parts != null) {
                                foreach (TypeContainer part in partial_parts) {
                                        part.DoResolveFieldInitializers (ec);
                                }
                        }
                        DoResolveFieldInitializers (ec);
                }

                void DoResolveFieldInitializers (EmitContext ec)
                {
                        if (ec.IsStatic) {
                                if (initialized_static_fields == null)
                                        return;

                                bool has_complex_initializer = !RootContext.Optimize;
                                int i;
                                ExpressionStatement [] init = new ExpressionStatement [initialized_static_fields.Count];
                                for (i = 0; i < initialized_static_fields.Count; ++i) {
                                        FieldInitializer fi = (FieldInitializer) initialized_static_fields [i];
                                        ExpressionStatement s = fi.ResolveStatement (ec);
                                        if (s == null) {
                                                s = EmptyExpressionStatement.Instance;
                                        } else if (fi.IsComplexInitializer) {
                                                has_complex_initializer |= true;
                                        }

                                        init [i] = s;
                                }

                                for (i = 0; i < initialized_static_fields.Count; ++i) {
                                        FieldInitializer fi = (FieldInitializer) initialized_static_fields [i];
                                        //
                                        // Need special check to not optimize code like this
                                        // static int a = b = 5;
                                        // static int b = 0;
                                        //
                                        if (!has_complex_initializer && fi.IsDefaultInitializer)
                                                continue;

                                        ec.CurrentBlock.AddScopeStatement (new StatementExpression (init [i]));
                                }

                                return;
                        }

                        if (initialized_fields == null)
                                return;

                        for (int i = 0; i < initialized_fields.Count; ++i) {
                                FieldInitializer fi = (FieldInitializer) initialized_fields [i];
                                ExpressionStatement s = fi.ResolveStatement (ec);
                                if (s == null)
                                        continue;

                                //
                                // Field is re-initialized to its default value => removed
                                //
                                if (fi.IsDefaultInitializer && RootContext.Optimize)
                                        continue;

                                ec.CurrentBlock.AddScopeStatement (new StatementExpression (s));
                        }
                }

                //
                // Emits the instance field initializers
                //
                public bool EmitFieldInitializers (EmitContext ec)
                {
                        if (partial_parts != null) {
                                foreach (TypeContainer part in partial_parts)
                                        part.EmitFieldInitializers (ec);
                        }

                        ArrayList fields;
                        
                        if (ec.IsStatic){
                                fields = initialized_static_fields;
                        } else {
                                fields = initialized_fields;
                        }

                        if (fields == null)
                                return true;

                        foreach (FieldInitializer f in fields) {
                                f.EmitStatement (ec);
                        }
                        return true;
                }
                
                public override string DocComment {
                        get {
                                return comment;
                        }
                        set {
                                if (value == null)
                                        return;

                                comment += value;
                        }
                }

                public PendingImplementation PendingImplementations {
                        get { return pending; }
                }

                public override bool GetClsCompliantAttributeValue ()
                {
                        if (PartialContainer != this)
                                return PartialContainer.GetClsCompliantAttributeValue ();

                        return base.GetClsCompliantAttributeValue ();
                }

                public virtual void AddBasesForPart (DeclSpace part, ArrayList bases)
                {
                        // FIXME: get rid of partial_parts and store lists of bases of each part here
                        // assumed, not verified: 'part' is in 'partial_parts' 
                        ((TypeContainer) part).type_bases = bases;
                }

                /// <summary>
                ///   This function computes the Base class and also the
                ///   list of interfaces that the class or struct @c implements.
                ///   
                ///   The return value is an array (might be null) of
                ///   interfaces implemented (as Types).
                ///   
                ///   The @base_class argument is set to the base object or null
                ///   if this is `System.Object'. 
                /// </summary>
                protected virtual TypeExpr[] ResolveBaseTypes (out TypeExpr base_class)
                {
                        base_class = null;
                        if (type_bases == null)
                                return null;

                        int count = type_bases.Count;
                        TypeExpr [] ifaces = null;
                        for (int i = 0, j = 0; i < count; i++){
                                FullNamedExpression fne = (FullNamedExpression) type_bases [i];

                                //
                                // Standard ResolveAsTypeTerminal cannot be used in this case because
                                // it does ObsoleteAttribute and constraint checks which require
                                // base type to be set
                                //
                                TypeExpr fne_resolved = fne.ResolveAsBaseTerminal (this, false);
                                if (fne_resolved == null)
                                        continue;

                                if (i == 0 && Kind == Kind.Class && !fne_resolved.Type.IsInterface) {
                                        if (fne_resolved is DynamicTypeExpr)
                                                Report.Error (1965, Location, "Class `{0}' cannot derive from dynamic type",
                                                        GetSignatureForError ());
                                        else
                                                base_class = fne_resolved;
                                        continue;
                                }

                                if (ifaces == null)
                                        ifaces = new TypeExpr [count - i];

                                if (fne_resolved.Type.IsInterface) {
                                        for (int ii = 0; ii < j; ++ii) {
                                                if (TypeManager.IsEqual (fne_resolved.Type, ifaces [ii].Type)) {
                                                        Report.Error (528, Location, "`{0}' is already listed in interface list",
                                                                fne_resolved.GetSignatureForError ());
                                                        break;
                                                }
                                        }

                                        if (Kind == Kind.Interface && !IsAccessibleAs (fne_resolved.Type)) {
                                                Report.Error (61, fne.Location,
                                                        "Inconsistent accessibility: base interface `{0}' is less accessible than interface `{1}'",
                                                        fne_resolved.GetSignatureForError (), GetSignatureForError ());
                                        }
                                } else {
                                        Report.SymbolRelatedToPreviousError (fne_resolved.Type);
                                        if (Kind != Kind.Class) {
                                                Report.Error (527, fne.Location, "Type `{0}' in interface list is not an interface", fne_resolved.GetSignatureForError ());
                                        } else if (base_class != null)
                                                Report.Error (1721, fne.Location, "`{0}': Classes cannot have multiple base classes (`{1}' and `{2}')",
                                                        GetSignatureForError (), base_class.GetSignatureForError (), fne_resolved.GetSignatureForError ());
                                        else {
                                                Report.Error (1722, fne.Location, "`{0}': Base class `{1}' must be specified as first",
                                                        GetSignatureForError (), fne_resolved.GetSignatureForError ());
                                        }
                                }

                                ifaces [j++] = fne_resolved;
                        }

                        return ifaces;
                }

                TypeExpr[] GetNormalPartialBases (ref TypeExpr base_class)
                {
                        ArrayList ifaces = new ArrayList (0);
                        if (iface_exprs != null)
                                ifaces.AddRange (iface_exprs);

                        foreach (TypeContainer part in partial_parts) {
                                TypeExpr new_base_class;
                                TypeExpr[] new_ifaces = part.ResolveBaseTypes (out new_base_class);
                                if (new_base_class != TypeManager.system_object_expr) {
                                        if (base_class == TypeManager.system_object_expr)
                                                base_class = new_base_class;
                                        else {
                                                if (new_base_class != null && !new_base_class.Equals (base_class)) {
                                                        Report.SymbolRelatedToPreviousError (base_class.Location, "");
                                                        Report.Error (263, part.Location,
                                                                "Partial declarations of `{0}' must not specify different base classes",
                                                                part.GetSignatureForError ());

                                                        return null;
                                                }
                                        }
                                }

                                if (new_ifaces == null)
                                        continue;

                                foreach (TypeExpr iface in new_ifaces) {
                                        if (ifaces.Contains (iface))
                                                continue;

                                        ifaces.Add (iface);
                                }
                        }

                        if (ifaces.Count == 0)
                                return null;

                        return (TypeExpr[])ifaces.ToArray (typeof (TypeExpr));
                }

                bool CheckGenericInterfaces (Type[] ifaces)
                {
#if GMCS_SOURCE
                        ArrayList already_checked = new ArrayList ();

                        for (int i = 0; i < ifaces.Length; i++) {
                                Type iface = ifaces [i];
                                foreach (Type t in already_checked) {
                                        if (iface == t)
                                                continue;

                                        Type[] inferred = new Type [CountTypeParameters];
                                        if (!TypeManager.MayBecomeEqualGenericInstances (iface, t, inferred, null))
                                                continue;

                                        Report.Error (695, Location,
                                                "`{0}' cannot implement both `{1}' and `{2}' " +
                                                "because they may unify for some type parameter substitutions",
                                                TypeManager.CSharpName (TypeBuilder), TypeManager.CSharpName (iface),
                                                TypeManager.CSharpName (t));
                                        return false;
                                }

                                already_checked.Add (iface);
                        }
#endif

                        return true;
                }

                bool error = false;
                
                bool CreateTypeBuilder ()
                {
                        try {
                                Type default_parent = null;
                                if (Kind == Kind.Struct)
                                        default_parent = TypeManager.value_type;
                                else if (Kind == Kind.Enum)
                                        default_parent = TypeManager.enum_type;

                                //
                                // Sets .size to 1 for structs with no instance fields
                                //
                                int type_size = Kind == Kind.Struct && first_nonstatic_field == null ? 1 : 0;

                                if (IsTopLevel){
                                        if (TypeManager.NamespaceClash (Name, Location)) {
                                                return false;
                                        }

                                        ModuleBuilder builder = Module.Builder;
                                        TypeBuilder = builder.DefineType (
                                                Name, TypeAttr, default_parent, type_size);
                                } else {
                                        TypeBuilder builder = Parent.TypeBuilder;

                                        TypeBuilder = builder.DefineNestedType (
                                                Basename, TypeAttr, default_parent, type_size);
                                }
                        } catch (ArgumentException) {
                                Report.RuntimeMissingSupport (Location, "static classes");
                                return false;
                        }

                        TypeManager.AddUserType (this);

                        if (IsGeneric) {
                                string[] param_names = new string [TypeParameters.Length];
                                for (int i = 0; i < TypeParameters.Length; i++)
                                        param_names [i] = TypeParameters [i].Name;

#if GMCS_SOURCE
                                GenericTypeParameterBuilder[] gen_params = TypeBuilder.DefineGenericParameters (param_names);

                                int offset = CountTypeParameters - CurrentTypeParameters.Length;
                                if (offset > 0) {
                                        nested_gen_params = new GenericTypeParameterBuilder [offset];
                                        Array.Copy (gen_params, nested_gen_params, offset);
                                }

                                for (int i = offset; i < gen_params.Length; i++)
                                        CurrentTypeParameters [i - offset].Define (gen_params [i]);
#else
                                nested_gen_params = null;
                                throw new NotSupportedException ();
#endif
                        }

                        return true;
                }

                bool DefineBaseTypes ()
                {
                        iface_exprs = ResolveBaseTypes (out base_type);
                        if (partial_parts != null) {
                                iface_exprs = GetNormalPartialBases (ref base_type);
                        }

                        //
                        // GetClassBases calls ResolveBaseTypeExpr() on the various type expressions involved,
                        // which in turn should have called DefineType()s on base types if necessary.
                        //
                        // None of the code below should trigger DefineType()s on classes that we depend on.
                        // Thus, we are eligible to be on the topological sort `type_container_resolve_order'.
                        //
                        // Let's do it as soon as possible, since code below can call DefineType() on classes
                        // that depend on us to be populated before they are.
                        //
                        if (!(this is CompilerGeneratedClass))
                                RootContext.RegisterOrder (this); 

                        if (!CheckRecursiveDefinition (this))
                                return false;

                        if (base_type != null && base_type.Type != null) {
                                TypeBuilder.SetParent (base_type.Type);
                        }

                        // add interfaces that were not added at type creation
                        if (iface_exprs != null) {
                                ifaces = TypeManager.ExpandInterfaces (iface_exprs);
                                if (ifaces == null)
                                        return false;

                                foreach (Type itype in ifaces)
                                        TypeBuilder.AddInterfaceImplementation (itype);

                                if (!CheckGenericInterfaces (ifaces))
                                        return false;

                                TypeManager.RegisterBuilder (TypeBuilder, ifaces);
                        }

                        return true;
                }

                //
                // Defines the type in the appropriate ModuleBuilder or TypeBuilder.
                //
                public TypeBuilder CreateType ()
                {
                        if (TypeBuilder != null)
                                return TypeBuilder;

                        if (error)
                                return null;

                        if (!CreateTypeBuilder ()) {
                                error = true;
                                return null;
                        }

                        if (partial_parts != null) {
                                foreach (TypeContainer part in partial_parts)
                                        part.TypeBuilder = TypeBuilder;
                        }

                        if (Types != null) {
                                foreach (TypeContainer tc in Types) {
                                        if (tc.CreateType () == null) {
                                                error = true;
                                                return null;
                                        }
                                }
                        }

                        return TypeBuilder;
                }

                bool type_defined;

                public override TypeBuilder DefineType ()
                {
                        if (error)
                                return null;
                        if (type_defined)
                                return TypeBuilder;

                        type_defined = true;

                        if (CreateType () == null) {
                                error = true;
                                return null;
                        }

                        if (!DefineBaseTypes ()) {
                                error = true;
                                return null;
                        }

                        if (!DefineNestedTypes ()) {
                                error = true;
                                return null;
                        }

                        return TypeBuilder;
                }

                public override void SetParameterInfo (ArrayList constraints_list)
                {
                        base.SetParameterInfo (constraints_list);

                        if (!is_generic || PartialContainer == this)
                                return;

                        TypeParameter[] tc_names = PartialContainer.TypeParameters;
                        for (int i = 0; i < tc_names.Length; ++i) {
                                if (tc_names [i].Name != type_params [i].Name) {
                                        Report.SymbolRelatedToPreviousError (PartialContainer.Location, "");
                                        Report.Error (264, Location, "Partial declarations of `{0}' must have the same type parameter names in the same order",
                                                GetSignatureForError ());
                                        break;
                                }
                        }
                }

                void UpdateTypeParameterConstraints (TypeContainer part)
                {
                        TypeParameter[] current_params = CurrentTypeParameters;
                        for (int i = 0; i < current_params.Length; i++) {
                                Constraints c = part.CurrentTypeParameters [i].Constraints;
                                if (c == null)
                                        continue;

                                if (current_params [i].UpdateConstraints (part, c))
                                        continue;

                                Report.SymbolRelatedToPreviousError (Location, "");
                                Report.Error (265, part.Location,
                                        "Partial declarations of `{0}' have inconsistent constraints for type parameter `{1}'",
                                        GetSignatureForError (), current_params [i].GetSignatureForError ());
                        }
                }

                public bool ResolveType ()
                {
                        if (!DoResolveType ())
                                return false;

                        if (compiler_generated != null) {
                                foreach (CompilerGeneratedClass c in compiler_generated)
                                        if (!c.ResolveType ())
                                                return false;
                        }

                        return true;
                }

                protected virtual bool DoResolveType ()
                {
                        if (!IsGeneric)
                                return true;

                        if (PartialContainer != this)
                                throw new InternalErrorException ();

                        TypeExpr current_type = null;

                        foreach (TypeParameter type_param in CurrentTypeParameters) {
                                if (!type_param.Resolve (this)) {
                                        error = true;
                                        return false;
                                }
                        }

                        if (partial_parts != null && is_generic) {
                                foreach (TypeContainer part in partial_parts)
                                        UpdateTypeParameterConstraints (part);
                        }

                        for (int i = 0; i < TypeParameters.Length; ++i) {
                                //
                                // FIXME: Same should be done for delegates
                                // TODO: Quite ugly way how to propagate constraints to
                                // nested types
                                //
                                if (nested_gen_params != null && i < nested_gen_params.Length) {
                                        TypeParameters [i].SetConstraints (nested_gen_params [i]);
                                } else {
                                        if (!TypeParameters [i].DefineType (this)) {
                                                error = true;
                                                return false;
                                        }
                                }
                        }

                        // TODO: Very strange, why not simple make generic type from
                        // current type parameters
                        current_type = new GenericTypeExpr (this, Location);
                        current_type = current_type.ResolveAsTypeTerminal (this, false);
                        if (current_type == null) {
                                error = true;
                                return false;
                        }

                        CurrentType = current_type.Type;
                        return true;
                }

                protected virtual bool DefineNestedTypes ()
                {
                        if (Types != null) {
                                foreach (TypeContainer tc in Types)
                                        if (tc.DefineType () == null)
                                                return false;
                        }

                        if (Delegates != null) {
                                foreach (Delegate d in Delegates)
                                        if (d.DefineType () == null)
                                                return false;
                        }

                        return true;
                }

                TypeContainer InTransit;

                protected bool CheckRecursiveDefinition (TypeContainer tc)
                {
                        if (InTransit != null) {
                                Report.SymbolRelatedToPreviousError (this);
                                if (this is Interface)
                                        Report.Error (
                                                529, tc.Location, "Inherited interface `{0}' causes a " +
                                                "cycle in the interface hierarchy of `{1}'",
                                                GetSignatureForError (), tc.GetSignatureForError ());
                                else
                                        Report.Error (
                                                146, tc.Location, "Circular base class dependency " +
                                                "involving `{0}' and `{1}'",
                                                tc.GetSignatureForError (), GetSignatureForError ());
                                return false;
                        }

                        InTransit = tc;

                        if (base_type != null && base_type.Type != null) {
                                Type t = TypeManager.DropGenericTypeArguments (base_type.Type);
                                TypeContainer ptc = TypeManager.LookupTypeContainer (t);
                                if ((ptc != null) && !ptc.CheckRecursiveDefinition (this))
                                        return false;
                        }

                        if (iface_exprs != null) {
                                foreach (TypeExpr iface in iface_exprs) {
                                        Type itype = TypeManager.DropGenericTypeArguments (iface.Type);
                                        TypeContainer ptc = TypeManager.LookupTypeContainer (itype);
                                        if ((ptc != null) && !ptc.CheckRecursiveDefinition (this))
                                                return false;
                                }
                        }

                        if (!IsTopLevel && !Parent.PartialContainer.CheckRecursiveDefinition (this))
                                return false;

                        InTransit = null;
                        return true;
                }

                /// <summary>
                ///   Populates our TypeBuilder with fields and methods
                /// </summary>
                public override bool Define ()
                {
                        if (members_defined)
                                return members_defined_ok;

                        members_defined_ok = DoDefineMembers ();
                        members_defined = true;

                        return members_defined_ok;
                }

                protected virtual bool DoDefineMembers ()
                {
                        if (iface_exprs != null) {
                                foreach (TypeExpr iface in iface_exprs) {
                                        ObsoleteAttribute oa = AttributeTester.GetObsoleteAttribute (iface.Type);
                                        if ((oa != null) && !IsInObsoleteScope)
                                                AttributeTester.Report_ObsoleteMessage (
                                                        oa, iface.GetSignatureForError (), Location);

                                        GenericTypeExpr ct = iface as GenericTypeExpr;
                                        if (ct != null) {
                                                // TODO: passing `this' is wrong, should be base type iface instead
                                                TypeManager.CheckTypeVariance (ct.Type, Variance.Covariant, this);

                                                if (!ct.CheckConstraints (this))
                                                        return false;
                                        }
                                }
                        }

                        if (base_type != null) {
                                ObsoleteAttribute obsolete_attr = AttributeTester.GetObsoleteAttribute (base_type.Type);
                                if (obsolete_attr != null && !IsInObsoleteScope)
                                        AttributeTester.Report_ObsoleteMessage (obsolete_attr, base_type.GetSignatureForError (), Location);

                                GenericTypeExpr ct = base_type as GenericTypeExpr;
                                if ((ct != null) && !ct.CheckConstraints (this))
                                        return false;
                                
                                TypeContainer baseContainer = TypeManager.LookupTypeContainer(base_type.Type);
                                if (baseContainer != null)
                                        baseContainer.Define();                         
                                
                                member_cache = new MemberCache (base_type.Type, this);
                        } else if (Kind == Kind.Interface) {
                                member_cache = new MemberCache (null, this);
                                Type [] ifaces = TypeManager.GetInterfaces (TypeBuilder);
                                for (int i = 0; i < ifaces.Length; ++i)
                                        member_cache.AddInterface (TypeManager.LookupMemberCache (ifaces [i]));
                        } else {
                                member_cache = new MemberCache (null, this);
                        }

                        if (types != null)
                                foreach (TypeContainer tc in types)
                                        member_cache.AddNestedType (tc);

                        if (delegates != null)
                                foreach (Delegate d in delegates)
                                        member_cache.AddNestedType (d);

                        if (partial_parts != null) {
                                foreach (TypeContainer part in partial_parts)
                                        part.member_cache = member_cache;
                        }

                        if (!IsTopLevel) {
                                MemberInfo conflict_symbol = Parent.PartialContainer.FindBaseMemberWithSameName (Basename, false);
                                if (conflict_symbol == null) {
                                        if ((ModFlags & Modifiers.NEW) != 0)
                                                Report.Warning (109, 4, Location, "The member `{0}' does not hide an inherited member. The new keyword is not required", GetSignatureForError ());
                                } else {
                                        if ((ModFlags & Modifiers.NEW) == 0) {
                                                Report.SymbolRelatedToPreviousError (conflict_symbol);
                                                Report.Warning (108, 2, Location, "`{0}' hides inherited member `{1}'. Use the new keyword if hiding was intended",
                                                        GetSignatureForError (), TypeManager.GetFullNameSignature (conflict_symbol));
                                        }
                                }
                        }

                        DefineContainerMembers (constants);
                        DefineContainerMembers (fields);

                        if (Kind == Kind.Struct || Kind == Kind.Class) {
                                pending = PendingImplementation.GetPendingImplementations (this);

                                if (requires_delayed_unmanagedtype_check) {
                                        requires_delayed_unmanagedtype_check = false;
                                        foreach (FieldBase f in fields) {
                                                if (f.MemberType != null && f.MemberType.IsPointer)
                                                        TypeManager.VerifyUnManaged (f.MemberType, f.Location);
                                        }
                                }
                        }
                
                        //
                        // Constructors are not in the defined_names array
                        //
                        DefineContainerMembers (instance_constructors);
                
                        DefineContainerMembers (events);
                        DefineContainerMembers (ordered_explicit_member_list);
                        DefineContainerMembers (ordered_member_list);

                        DefineContainerMembers (operators);
                        DefineContainerMembers (delegates);

                        ComputeIndexerName();
                        CheckEqualsAndGetHashCode();

                        if (CurrentType != null) {
                                GenericType = CurrentType;
                        }

                        //
                        // FIXME: This hack is needed because member cache does not work
                        // with generic types, we rely on runtime to inflate dynamic types.
                        // TODO: This hack requires member cache refactoring to be removed
                        //
                        if (TypeManager.IsGenericType (TypeBuilder))
                                member_cache = new MemberCache (this);

                        return true;
                }

                protected virtual void DefineContainerMembers (MemberCoreArrayList mcal)
                {
                        if (mcal != null)
                                mcal.DefineContainerMembers ();
                }
                
                protected virtual void ComputeIndexerName ()
                {
                        if (indexers == null)
                                return;

                        string class_indexer_name = null;

                        //
                        // If there's both an explicit and an implicit interface implementation, the
                        // explicit one actually implements the interface while the other one is just
                        // a normal indexer.  See bug #37714.
                        //

                        // Invariant maintained by AddIndexer(): All explicit interface indexers precede normal indexers
                        foreach (Indexer i in indexers) {
                                if (i.InterfaceType != null) {
                                        if (seen_normal_indexers)
                                                throw new Exception ("Internal Error: 'Indexers' array not sorted properly.");
                                        continue;
                                }

                                seen_normal_indexers = true;

                                if (class_indexer_name == null) {
                                        class_indexer_name = i.ShortName;
                                        continue;
                                }

                                if (i.ShortName != class_indexer_name)
                                        Report.Error (668, i.Location, "Two indexers have different names; the IndexerName attribute must be used with the same name on every indexer within a type");
                        }

                        if (class_indexer_name != null)
                                indexer_name = class_indexer_name;
                }

                protected virtual void EmitIndexerName ()
                {
                        if (!seen_normal_indexers)
                                return;

                        PredefinedAttribute pa = PredefinedAttributes.Get.DefaultMember;
                        if (pa.Constructor == null &&
                                !pa.ResolveConstructor (Location, TypeManager.string_type))
                                return;

                        CustomAttributeBuilder cb = new CustomAttributeBuilder (pa.Constructor, new string [] { IndexerName });
                        TypeBuilder.SetCustomAttribute (cb);
                }

                protected virtual void CheckEqualsAndGetHashCode ()
                {
                        if (methods == null)
                                return;

                        if (HasEquals && !HasGetHashCode) {
                                Report.Warning (659, 3, this.Location, "`{0}' overrides Object.Equals(object) but does not override Object.GetHashCode()", this.GetSignatureForError ());
                        }
                }

                public MemberInfo FindBaseMemberWithSameName (string name, bool ignore_methods)
                {
                        return BaseCache == null ? null : BaseCache.FindMemberWithSameName (name, ignore_methods, null);
                }

                /// <summary>
                ///   This function is based by a delegate to the FindMembers routine
                /// </summary>
                static bool AlwaysAccept (MemberInfo m, object filterCriteria)
                {
                        return true;
                }

                /// <summary>
                ///   This filter is used by FindMembers, and we just keep
                ///   a global for the filter to `AlwaysAccept'
                /// </summary>
                static MemberFilter accepting_filter;

                
                static TypeContainer ()
                {
                        accepting_filter = new MemberFilter (AlwaysAccept);
                }

                public MethodInfo[] GetMethods ()
                {
                        ArrayList members = new ArrayList ();

                        Define ();

                        if (methods != null) {
                                int len = methods.Count;
                                for (int i = 0; i < len; i++) {
                                        Method m = (Method) methods [i];

                                        members.Add (m.MethodBuilder);
                                }
                        }

                        if (operators != null) {
                                int len = operators.Count;
                                for (int i = 0; i < len; i++) {
                                        Operator o = (Operator) operators [i];

                                        members.Add (o.MethodBuilder);
                                }
                        }

                        if (properties != null) {
                                int len = properties.Count;
                                for (int i = 0; i < len; i++) {
                                        Property p = (Property) properties [i];

                                        if (p.GetBuilder != null)
                                                members.Add (p.GetBuilder);
                                        if (p.SetBuilder != null)
                                                members.Add (p.SetBuilder);
                                }
                        }
                                
                        if (indexers != null) {
                                int len = indexers.Count;
                                for (int i = 0; i < len; i++) {
                                        Indexer ix = (Indexer) indexers [i];

                                        if (ix.GetBuilder != null)
                                                members.Add (ix.GetBuilder);
                                        if (ix.SetBuilder != null)
                                                members.Add (ix.SetBuilder);
                                }
                        }

                        if (events != null) {
                                int len = events.Count;
                                for (int i = 0; i < len; i++) {
                                        Event e = (Event) events [i];

                                        if (e.AddBuilder != null)
                                                members.Add (e.AddBuilder);
                                        if (e.RemoveBuilder != null)
                                                members.Add (e.RemoveBuilder);
                                }
                        }

                        MethodInfo[] retMethods = new MethodInfo [members.Count];
                        members.CopyTo (retMethods, 0);
                        return retMethods;
                }
                
                // Indicated whether container has StructLayout attribute set Explicit
                public bool HasExplicitLayout {
                        get { return (caching_flags & Flags.HasExplicitLayout) != 0; }
                        set { caching_flags |= Flags.HasExplicitLayout; }
                }

                public bool HasStructLayout {
                        get { return (caching_flags & Flags.HasStructLayout) != 0; }
                        set { caching_flags |= Flags.HasStructLayout; }
                }

                //
                // Return the nested type with name @name.  Ensures that the nested type
                // is defined if necessary.  Do _not_ use this when you have a MemberCache handy.
                //
                public Type FindNestedType (string name)
                {
                        if (PartialContainer != this)
                                throw new InternalErrorException ("should not happen");

                        ArrayList [] lists = { types, delegates };

                        for (int j = 0; j < lists.Length; ++j) {
                                ArrayList list = lists [j];
                                if (list == null)
                                        continue;
                                
                                int len = list.Count;
                                for (int i = 0; i < len; ++i) {
                                        DeclSpace ds = (DeclSpace) list [i];
                                        if (ds.Basename == name) {
                                                return ds.DefineType ();
                                        }
                                }
                        }

                        return null;
                }

                private void FindMembers_NestedTypes (int modflags,
                                                      BindingFlags bf, MemberFilter filter, object criteria,
                                                      ref ArrayList members)
                {
                        ArrayList [] lists = { types, delegates };

                        for (int j = 0; j < lists.Length; ++j) {
                                ArrayList list = lists [j];
                                if (list == null)
                                        continue;
                        
                                int len = list.Count;
                                for (int i = 0; i < len; i++) {
                                        DeclSpace ds = (DeclSpace) list [i];
                                        
                                        if ((ds.ModFlags & modflags) == 0)
                                                continue;
                                        
                                        TypeBuilder tb = ds.TypeBuilder;
                                        if (tb == null) {
                                                if (!(criteria is string) || ds.Basename.Equals (criteria))
                                                        tb = ds.DefineType ();
                                        }
                                        
                                        if (tb != null && (filter (tb, criteria) == true)) {
                                                if (members == null)
                                                        members = new ArrayList ();
                                                
                                                members.Add (tb);
                                        }
                                }
                        }
                }
                
                /// <summary>
                ///   This method returns the members of this type just like Type.FindMembers would
                ///   Only, we need to use this for types which are _being_ defined because MS' 
                ///   implementation can't take care of that.
                /// </summary>
                //
                // FIXME: return an empty static array instead of null, that cleans up
                // some code and is consistent with some coding conventions I just found
                // out existed ;-)
                //
                //
                // Notice that in various cases we check if our field is non-null,
                // something that would normally mean that there was a bug elsewhere.
                //
                // The problem happens while we are defining p-invoke methods, as those
                // will trigger a FindMembers, but this happens before things are defined
                //
                // Since the whole process is a no-op, it is fine to check for null here.
                //
                // TODO: This approach will be one day completely removed, it's already
                // used at few places only
                //
                //
                public override MemberList FindMembers (MemberTypes mt, BindingFlags bf,
                                                        MemberFilter filter, object criteria)
                {
                        ArrayList members = null;

                        int modflags = 0;
                        if ((bf & BindingFlags.Public) != 0)
                                modflags |= Modifiers.PUBLIC | Modifiers.PROTECTED |
                                        Modifiers.INTERNAL;
                        if ((bf & BindingFlags.NonPublic) != 0)
                                modflags |= Modifiers.PRIVATE;

                        int static_mask = 0, static_flags = 0;
                        switch (bf & (BindingFlags.Static | BindingFlags.Instance)) {
                        case BindingFlags.Static:
                                static_mask = static_flags = Modifiers.STATIC;
                                break;

                        case BindingFlags.Instance:
                                static_mask = Modifiers.STATIC;
                                static_flags = 0;
                                break;

                        default:
                                static_mask = static_flags = 0;
                                break;
                        }

                        Timer.StartTimer (TimerType.TcFindMembers);

                        if (filter == null)
                                filter = accepting_filter; 

                        if ((mt & MemberTypes.Field) != 0) {
                                if (fields != null) {
                                        int len = fields.Count;
                                        for (int i = 0; i < len; i++) {
                                                FieldBase f = (FieldBase) fields [i];
                                                
                                                if ((f.ModFlags & modflags) == 0)
                                                        continue;
                                                if ((f.ModFlags & static_mask) != static_flags)
                                                        continue;

                                                FieldBuilder fb = f.FieldBuilder;
                                                if (fb != null && filter (fb, criteria) == true) {
                                                        if (members == null)
                                                                members = new ArrayList ();
                                                        
                                                        members.Add (fb);
                                                }
                                        }
                                }

                                if (constants != null) {
                                        int len = constants.Count;
                                        for (int i = 0; i < len; i++) {
                                                Const con = (Const) constants [i];
                                                
                                                if ((con.ModFlags & modflags) == 0)
                                                        continue;
                                                if ((con.ModFlags & static_mask) != static_flags)
                                                        continue;

                                                FieldBuilder fb = con.FieldBuilder;
                                                if (fb == null) {
                                                        if (con.Define ())
                                                                fb = con.FieldBuilder;
                                                }
                                                if (fb != null && filter (fb, criteria) == true) {
                                                        if (members == null)
                                                                members = new ArrayList ();
                                                        
                                                        members.Add (fb);
                                                }
                                        }
                                }
                        }

                        if ((mt & MemberTypes.Method) != 0) {
                                if (methods != null) {
                                        int len = methods.Count;
                                        for (int i = 0; i < len; i++) {
                                                MethodOrOperator m = (MethodOrOperator) methods [i];
                                                
                                                if ((m.ModFlags & modflags) == 0)
                                                        continue;
                                                if ((m.ModFlags & static_mask) != static_flags)
                                                        continue;
                                                
                                                MethodBuilder mb = m.MethodBuilder;

                                                if (mb != null && filter (mb, criteria) == true) {
                                                        if (members == null)
                                                                members = new ArrayList ();
                                                        
                                                        members.Add (mb);
                                                }
                                        }
                                }

                                if (operators != null) {
                                        int len = operators.Count;
                                        for (int i = 0; i < len; i++) {
                                                Operator o = (Operator) operators [i];
                                                
                                                if ((o.ModFlags & modflags) == 0)
                                                        continue;
                                                if ((o.ModFlags & static_mask) != static_flags)
                                                        continue;
                                                
                                                MethodBuilder ob = o.MethodBuilder;
                                                if (ob != null && filter (ob, criteria) == true) {
                                                        if (members == null)
                                                                members = new ArrayList ();
                                                        
                                                        members.Add (ob);
                                                }
                                        }
                                }

                                if (events != null) {
                                        foreach (Event e in events) {
                                                if ((e.ModFlags & modflags) == 0)
                                                        continue;
                                                if ((e.ModFlags & static_mask) != static_flags)
                                                        continue;

                                                MethodBuilder b = e.AddBuilder;
                                                if (b != null && filter (b, criteria)) {
                                                        if (members == null)
                                                                members = new ArrayList (4);

                                                        members.Add (b);
                                                }

                                                b = e.RemoveBuilder;
                                                if (b != null && filter (b, criteria)) {
                                                        if (members == null) 
                                                                members = new ArrayList (4);

                                                        members.Add (b);
                                                }
                                        }
                                }

                                if (properties != null) {
                                        int len = properties.Count;
                                        for (int i = 0; i < len; i++) {
                                                Property p = (Property) properties [i];
                                                
                                                if ((p.ModFlags & modflags) == 0)
                                                        continue;
                                                if ((p.ModFlags & static_mask) != static_flags)
                                                        continue;
                                                
                                                MethodBuilder b;

                                                b = p.GetBuilder;
                                                if (b != null && filter (b, criteria) == true) {
                                                        if (members == null)
                                                                members = new ArrayList ();
                                                        
                                                        members.Add (b);
                                                }

                                                b = p.SetBuilder;
                                                if (b != null && filter (b, criteria) == true) {
                                                        if (members == null)
                                                                members = new ArrayList ();
                                                        
                                                        members.Add (b);
                                                }
                                        }
                                }
                                
                                if (indexers != null) {
                                        int len = indexers.Count;
                                        for (int i = 0; i < len; i++) {
                                                Indexer ix = (Indexer) indexers [i];
                                                
                                                if ((ix.ModFlags & modflags) == 0)
                                                        continue;
                                                if ((ix.ModFlags & static_mask) != static_flags)
                                                        continue;
                                                
                                                MethodBuilder b;

                                                b = ix.GetBuilder;
                                                if (b != null && filter (b, criteria) == true) {
                                                        if (members == null)
                                                                members = new ArrayList ();
                                                        
                                                        members.Add (b);
                                                }

                                                b = ix.SetBuilder;
                                                if (b != null && filter (b, criteria) == true) {
                                                        if (members == null)
                                                                members = new ArrayList ();
                                                        
                                                        members.Add (b);
                                                }
                                        }
                                }
                        }

                        if ((mt & MemberTypes.Event) != 0) {
                                if (events != null) {
                                        int len = events.Count;
                                        for (int i = 0; i < len; i++) {
                                                Event e = (Event) events [i];
                                                
                                                if ((e.ModFlags & modflags) == 0)
                                                        continue;
                                                if ((e.ModFlags & static_mask) != static_flags)
                                                        continue;

                                                MemberInfo eb = e.EventBuilder;
                                                if (eb != null && filter (eb, criteria) == true) {
                                                        if (members == null)
                                                                members = new ArrayList ();
                                                        
                                                        members.Add (e.EventBuilder);
                                                }
                                        }
                                }
                        }
                        
                        if ((mt & MemberTypes.Property) != 0){
                                if (properties != null) {
                                        int len = properties.Count;
                                        for (int i = 0; i < len; i++) {
                                                Property p = (Property) properties [i];
                                                
                                                if ((p.ModFlags & modflags) == 0)
                                                        continue;
                                                if ((p.ModFlags & static_mask) != static_flags)
                                                        continue;

                                                MemberInfo pb = p.PropertyBuilder;
                                                if (pb != null && filter (pb, criteria) == true) {
                                                        if (members == null)
                                                                members = new ArrayList ();
                                                        
                                                        members.Add (p.PropertyBuilder);
                                                }
                                        }
                                }

                                if (indexers != null) {
                                        int len = indexers.Count;
                                        for (int i = 0; i < len; i++) {
                                                Indexer ix = (Indexer) indexers [i];
                                                
                                                if ((ix.ModFlags & modflags) == 0)
                                                        continue;
                                                if ((ix.ModFlags & static_mask) != static_flags)
                                                        continue;

                                                MemberInfo ib = ix.PropertyBuilder;
                                                if (ib != null && filter (ib, criteria) == true) {
                                                        if (members == null)
                                                                members = new ArrayList ();
                                                        
                                                        members.Add (ix.PropertyBuilder);
                                                }
                                        }
                                }
                        }
                        
                        if ((mt & MemberTypes.NestedType) != 0)
                                FindMembers_NestedTypes (modflags, bf, filter, criteria, ref members);

                        if ((mt & MemberTypes.Constructor) != 0){
                                if (((bf & BindingFlags.Instance) != 0) && (instance_constructors != null)){
                                        int len = instance_constructors.Count;
                                        for (int i = 0; i < len; i++) {
                                                Constructor c = (Constructor) instance_constructors [i];
                                                
                                                ConstructorBuilder cb = c.ConstructorBuilder;
                                                if (cb != null && filter (cb, criteria) == true) {
                                                        if (members == null)
                                                                members = new ArrayList ();

                                                        members.Add (cb);
                                                }
                                        }
                                }

                                if (((bf & BindingFlags.Static) != 0) && (default_static_constructor != null)){
                                        ConstructorBuilder cb =
                                                default_static_constructor.ConstructorBuilder;
                                        
                                        if (cb != null && filter (cb, criteria) == true) {
                                                if (members == null)
                                                        members = new ArrayList ();
                                                
                                                members.Add (cb);
                                        }
                                }
                        }

                        //
                        // Lookup members in base if requested.
                        //
                        if ((bf & BindingFlags.DeclaredOnly) == 0) {
                                if (TypeBuilder.BaseType != null) {
                                        MemberList list = FindMembers (TypeBuilder.BaseType, mt, bf, filter, criteria);
                                        if (list.Count > 0) {
                                                if (members == null)
                                                        members = new ArrayList ();
                                        
                                                members.AddRange (list);
                                        }
                                }
                        }

                        Timer.StopTimer (TimerType.TcFindMembers);

                        if (members == null)
                                return MemberList.Empty;
                        else
                                return new MemberList (members);
                }

                public override MemberCache MemberCache {
                        get {
                                return member_cache;
                        }
                }

                public static MemberList FindMembers (Type t, MemberTypes mt, BindingFlags bf,
                                                      MemberFilter filter, object criteria)
                {
                        DeclSpace ds = TypeManager.LookupDeclSpace (t);

                        if (ds != null)
                                return ds.FindMembers (mt, bf, filter, criteria);
                        else
                                return new MemberList (t.FindMembers (mt, bf, filter, criteria));
                }

                /// <summary>
                ///   Emits the values for the constants
                /// </summary>
                public void EmitConstants ()
                {
                        if (constants != null)
                                foreach (Const con in constants)
                                        con.Emit ();
                        return;
                }

                static void CheckMemberUsage (MemberCoreArrayList al, string member_type)
                {
                        if (al == null)
                                return;

                        foreach (MemberCore mc in al) {
                                if ((mc.ModFlags & Modifiers.Accessibility) != Modifiers.PRIVATE)
                                        continue;

                                if (!mc.IsUsed && (mc.caching_flags & Flags.Excluded) == 0) {
                                        Report.Warning (169, 3, mc.Location, "The private {0} `{1}' is never used", member_type, mc.GetSignatureForError ());
                                }
                        }
                }

                public virtual void VerifyMembers ()
                {
                        //
                        // Check for internal or private fields that were never assigned
                        //
                        if (Report.WarningLevel >= 3) {
                                CheckMemberUsage (properties, "property");
                                CheckMemberUsage (methods, "method");
                                CheckMemberUsage (constants, "constant");

                                if (fields != null){
                                        bool is_type_exposed = Kind == Kind.Struct || IsExposedFromAssembly ();
                                        foreach (FieldBase f in fields) {
                                                if ((f.ModFlags & Modifiers.Accessibility) != Modifiers.PRIVATE) {
                                                        if (is_type_exposed)
                                                                continue;

                                                        f.SetMemberIsUsed ();
                                                }                               
                                                
                                                if (!f.IsUsed){
                                                        if ((f.caching_flags & Flags.IsAssigned) == 0)
                                                                Report.Warning (169, 3, f.Location, "The private field `{0}' is never used", f.GetSignatureForError ());
                                                        else {
#if NET_2_0
                                                                const int error_code = 414;
#else
                                                                const int error_code = 169;
#endif
                                                                Report.Warning (error_code, 3, f.Location, "The private field `{0}' is assigned but its value is never used",
                                                                        f.GetSignatureForError ());
                                                        }
                                                        continue;
                                                }
                                                
                                                //
                                                // Only report 649 on level 4
                                                //
                                                if (Report.WarningLevel < 4)
                                                        continue;
                                                
                                                if ((f.caching_flags & Flags.IsAssigned) != 0)
                                                        continue;

                                                //
                                                // Don't be pendatic over serializable attributes
                                                //
                                                if (f.OptAttributes != null || PartialContainer.HasStructLayout)
                                                        continue;
                                                
                                                Constant c = New.Constantify (f.MemberType);
                                                Report.Warning (649, 4, f.Location, "Field `{0}' is never assigned to, and will always have its default value `{1}'",
                                                        f.GetSignatureForError (), c == null ? "null" : c.AsString ());
                                        }
                                }
                        }
                }

                // TODO: move to ClassOrStruct
                void EmitConstructors ()
                {
                        if (instance_constructors == null)
                                return;

                        if (TypeBuilder.IsSubclassOf (TypeManager.attribute_type) && RootContext.VerifyClsCompliance && IsClsComplianceRequired ()) {
                                bool has_compliant_args = false;

                                foreach (Constructor c in instance_constructors) {
                                        try {
                                                c.Emit ();
                                        }
                                        catch (Exception e) {
                                                throw new InternalErrorException (c, e);
                                        }

                                        if (has_compliant_args)
                                                continue;

                                        has_compliant_args = c.HasCompliantArgs;
                                }
                                if (!has_compliant_args)
                                        Report.Warning (3015, 1, Location, "`{0}' has no accessible constructors which use only CLS-compliant types", GetSignatureForError ());
                        } else {
                                foreach (Constructor c in instance_constructors) {
                                        try {
                                                c.Emit ();
                                        }
                                        catch (Exception e) {
                                                throw new InternalErrorException (c, e);
                                        }
                                }
                        }
                }

                /// <summary>
                ///   Emits the code, this step is performed after all
                ///   the types, enumerations, constructors
                /// </summary>
                public virtual void EmitType ()
                {
                        if (OptAttributes != null)
                                OptAttributes.Emit ();

                        Emit ();

                        EmitConstructors ();

                        // Can not continue if constants are broken
                        EmitConstants ();
                        if (Report.Errors > 0)
                                return;

                        if (default_static_constructor != null)
                                default_static_constructor.Emit ();
                        
                        if (operators != null)
                                foreach (Operator o in operators)
                                        o.Emit ();

                        if (properties != null)
                                foreach (Property p in properties)
                                        p.Emit ();

                        if (indexers != null) {
                                foreach (Indexer indx in indexers)
                                        indx.Emit ();
                                EmitIndexerName ();
                        }

                        if (events != null){
                                foreach (Event e in Events)
                                        e.Emit ();
                        }

                        if (methods != null) {
                                for (int i = 0; i < methods.Count; ++i)
                                        ((MethodOrOperator) methods [i]).Emit ();
                        }
                        
                        if (fields != null)
                                foreach (FieldBase f in fields)
                                        f.Emit ();

                        if (delegates != null) {
                                foreach (Delegate d in Delegates) {
                                        d.Emit ();
                                }
                        }

                        if (pending != null)
                                pending.VerifyPendingMethods ();

                        if (Report.Errors > 0)
                                return;

                        if (compiler_generated != null) {
                                for (int i = 0; i < compiler_generated.Count; ++i)
                                        ((CompilerGeneratedClass) compiler_generated [i]).EmitType ();
                        }
                }
                
                public override void CloseType ()
                {
                        if ((caching_flags & Flags.CloseTypeCreated) != 0)
                                return;

                        try {
                                caching_flags |= Flags.CloseTypeCreated;
                                TypeBuilder.CreateType ();
                        } catch (TypeLoadException){
                                //
                                // This is fine, the code still created the type
                                //
//                              Report.Warning (-20, "Exception while creating class: " + TypeBuilder.Name);
//                              Console.WriteLine (e.Message);
                        } catch (Exception e) {
                                throw new InternalErrorException (this, e);
                        }
                        
                        if (Types != null){
                                foreach (TypeContainer tc in Types)
                                        if (tc.Kind == Kind.Struct)
                                                tc.CloseType ();

                                foreach (TypeContainer tc in Types)
                                        if (tc.Kind != Kind.Struct)
                                                tc.CloseType ();
                        }

                        if (Delegates != null)
                                foreach (Delegate d in Delegates)
                                        d.CloseType ();

                        if (compiler_generated != null)
                                foreach (CompilerGeneratedClass c in compiler_generated)
                                        c.CloseType ();
                        
                        PartialContainer = null;
                        types = null;
                        properties = null;
                        delegates = null;
                        fields = null;
                        initialized_fields = null;
                        initialized_static_fields = null;
                        constants = null;
                        ordered_explicit_member_list = null;
                        ordered_member_list = null;
                        methods = null;
                        events = null;
                        indexers = null;
                        operators = null;
                        compiler_generated = null;
                        default_constructor = null;
                        default_static_constructor = null;
                        type_bases = null;
                        OptAttributes = null;
                        ifaces = null;
                        base_cache = null;
                        member_cache = null;
                }

                //
                // Performs the validation on a Method's modifiers (properties have
                // the same properties).
                //
                public bool MethodModifiersValid (MemberCore mc)
                {
                        const int vao = (Modifiers.VIRTUAL | Modifiers.ABSTRACT | Modifiers.OVERRIDE);
                        const int va = (Modifiers.VIRTUAL | Modifiers.ABSTRACT);
                        const int nv = (Modifiers.NEW | Modifiers.VIRTUAL);
                        bool ok = true;
                        int flags = mc.ModFlags;
                        
                        //
                        // At most one of static, virtual or override
                        //
                        if ((flags & Modifiers.STATIC) != 0){
                                if ((flags & vao) != 0){
                                        Report.Error (112, mc.Location, "A static member `{0}' cannot be marked as override, virtual or abstract",
                                                mc.GetSignatureForError ());
                                        ok = false;
                                }
                        }

                        if (Kind == Kind.Struct){
                                if ((flags & va) != 0){
                                        Modifiers.Error_InvalidModifier (mc.Location, "virtual or abstract");
                                        ok = false;
                                }
                        }

                        if ((flags & Modifiers.OVERRIDE) != 0 && (flags & nv) != 0){
                                Report.Error (113, mc.Location, "A member `{0}' marked as override cannot be marked as new or virtual",
                                        mc.GetSignatureForError ());
                                ok = false;
                        }

                        //
                        // If the declaration includes the abstract modifier, then the
                        // declaration does not include static, virtual or extern
                        //
                        if ((flags & Modifiers.ABSTRACT) != 0){
                                if ((flags & Modifiers.EXTERN) != 0){
                                        Report.Error (
                                                180, mc.Location, "`{0}' cannot be both extern and abstract", mc.GetSignatureForError ());
                                        ok = false;
                                }

                                if ((flags & Modifiers.SEALED) != 0) {
                                        Report.Error (502, mc.Location, "`{0}' cannot be both abstract and sealed", mc.GetSignatureForError ());
                                        ok = false;
                                }

                                if ((flags & Modifiers.VIRTUAL) != 0){
                                        Report.Error (503, mc.Location, "The abstract method `{0}' cannot be marked virtual", mc.GetSignatureForError ());
                                        ok = false;
                                }

                                if ((ModFlags & Modifiers.ABSTRACT) == 0){
                                        Report.SymbolRelatedToPreviousError (this);
                                        Report.Error (513, mc.Location, "`{0}' is abstract but it is declared in the non-abstract class `{1}'",
                                                mc.GetSignatureForError (), GetSignatureForError ());
                                        ok = false;
                                }
                        }

                        if ((flags & Modifiers.PRIVATE) != 0){
                                if ((flags & vao) != 0){
                                        Report.Error (621, mc.Location, "`{0}': virtual or abstract members cannot be private", mc.GetSignatureForError ());
                                        ok = false;
                                }
                        }

                        if ((flags & Modifiers.SEALED) != 0){
                                if ((flags & Modifiers.OVERRIDE) == 0){
                                        Report.Error (238, mc.Location, "`{0}' cannot be sealed because it is not an override", mc.GetSignatureForError ());
                                        ok = false;
                                }
                        }

                        return ok;
                }

                public Constructor DefaultStaticConstructor {
                        get { return default_static_constructor; }
                }

                protected override bool VerifyClsCompliance ()
                {
                        if (!base.VerifyClsCompliance ())
                                return false;

                        VerifyClsName ();

                        Type base_type = TypeBuilder.BaseType;
                        if (base_type != null && !AttributeTester.IsClsCompliant (base_type)) {
                                Report.Warning (3009, 1, Location, "`{0}': base type `{1}' is not CLS-compliant", GetSignatureForError (), TypeManager.CSharpName (base_type));
                        }
                        return true;
                }


                /// <summary>
                /// Checks whether container name is CLS Compliant
                /// </summary>
                void VerifyClsName ()
                {
                        Hashtable base_members = base_cache == null ? 
                                new Hashtable () :
                                base_cache.GetPublicMembers ();
                        Hashtable this_members = new Hashtable ();

                        foreach (DictionaryEntry entry in defined_names) {
                                MemberCore mc = (MemberCore)entry.Value;
                                if (!mc.IsClsComplianceRequired ())
                                        continue;

                                string name = (string) entry.Key;
                                string basename = name.Substring (name.LastIndexOf ('.') + 1);

                                string lcase = basename.ToLower (System.Globalization.CultureInfo.InvariantCulture);
                                object found = base_members [lcase];
                                if (found == null) {
                                        found = this_members [lcase];
                                        if (found == null) {
                                                this_members.Add (lcase, mc);
                                                continue;
                                        }
                                }

                                if ((mc.ModFlags & Modifiers.OVERRIDE) != 0)
                                        continue;                                       

                                if (found is MemberInfo) {
                                        if (basename == ((MemberInfo) found).Name)
                                                continue;
                                        Report.SymbolRelatedToPreviousError ((MemberInfo) found);
                                } else {
                                        Report.SymbolRelatedToPreviousError ((MemberCore) found);
                                }

                                Report.Warning (3005, 1, mc.Location, "Identifier `{0}' differing only in case is not CLS-compliant", mc.GetSignatureForError ());
                        }
                }


                /// <summary>
                ///   Performs checks for an explicit interface implementation.  First it
                ///   checks whether the `interface_type' is a base inteface implementation.
                ///   Then it checks whether `name' exists in the interface type.
                /// </summary>
                public bool VerifyImplements (InterfaceMemberBase mb)
                {
                        if (ifaces != null) {
                                foreach (Type t in ifaces){
                                        if (TypeManager.IsEqual (t, mb.InterfaceType))
                                                return true;
                                }
                        }
                        
                        Report.SymbolRelatedToPreviousError (mb.InterfaceType);
                        Report.Error (540, mb.Location, "`{0}': containing type does not implement interface `{1}'",
                                mb.GetSignatureForError (), TypeManager.CSharpName (mb.InterfaceType));
                        return false;
                }

                public override Type LookupAnyGeneric (string typeName)
                {
                        if (types != null) {
                                foreach (TypeContainer tc in types) {
                                        if (!tc.IsGeneric)
                                                continue;

                                        int pos = tc.Basename.LastIndexOf ('`');
                                        if (pos == typeName.Length && String.Compare (typeName, 0, tc.Basename, 0, pos) == 0)
                                                return tc.TypeBuilder;
                                }
                        }

                        return base.LookupAnyGeneric (typeName);
                }

                public void Mark_HasEquals ()
                {
                        cached_method |= CachedMethods.Equals;
                }

                public void Mark_HasGetHashCode ()
                {
                        cached_method |= CachedMethods.GetHashCode;
                }

                /// <summary>
                /// Method container contains Equals method
                /// </summary>
                public bool HasEquals {
                        get {
                                return (cached_method & CachedMethods.Equals) != 0;
                        }
                }
 
                /// <summary>
                /// Method container contains GetHashCode method
                /// </summary>
                public bool HasGetHashCode {
                        get {
                                return (cached_method & CachedMethods.GetHashCode) != 0;
                        }
                }

                public bool HasStaticFieldInitializer {
                        get {
                                return (cached_method & CachedMethods.HasStaticFieldInitializer) != 0;
                        }
                        set {
                                if (value)
                                        cached_method |= CachedMethods.HasStaticFieldInitializer;
                                else
                                        cached_method &= ~CachedMethods.HasStaticFieldInitializer;
                        }
                }

                //
                // IMemberContainer
                //

                string IMemberContainer.Name {
                        get {
                                return Name;
                        }
                }

                Type IMemberContainer.Type {
                        get {
                                return TypeBuilder;
                        }
                }

                bool IMemberContainer.IsInterface {
                        get {
                                return Kind == Kind.Interface;
                        }
                }

                MemberList IMemberContainer.GetMembers (MemberTypes mt, BindingFlags bf)
                {
                        BindingFlags new_bf = bf | BindingFlags.DeclaredOnly;

                        if (GenericType != null)
                                return TypeManager.FindMembers (GenericType, mt, new_bf,
                                                                null, null);
                        else
                                return FindMembers (mt, new_bf, null, null);
                }

                //
                // Generates xml doc comments (if any), and if required,
                // handle warning report.
                //
                internal override void GenerateDocComment (DeclSpace ds)
                {
                        DocUtil.GenerateTypeDocComment (this, ds);
                }

                public override string DocCommentHeader {
                        get { return "T:"; }
                }

                public MemberCache BaseCache {
                        get {
                                if (base_cache != null)
                                        return base_cache;
                                if (TypeBuilder.BaseType != null)
                                        base_cache = TypeManager.LookupMemberCache (TypeBuilder.BaseType);
                                if (TypeBuilder.IsInterface)
                                        base_cache = TypeManager.LookupBaseInterfacesCache (TypeBuilder);
                                return base_cache;
                        }
                }
        }

        public abstract class ClassOrStruct : TypeContainer {
                ListDictionary declarative_security;

                public ClassOrStruct (NamespaceEntry ns, DeclSpace parent,
                                      MemberName name, Attributes attrs, Kind kind)
                        : base (ns, parent, name, attrs, kind)
                {
                }

                protected override bool AddToContainer (MemberCore symbol, string name)
                {
                        if (name == MemberName.Name) {
                                if (symbol is TypeParameter) {
                                        Report.Error (694, symbol.Location,
                                                "Type parameter `{0}' has same name as containing type, or method",
                                                symbol.GetSignatureForError ());
                                        return false;
                                }

                                InterfaceMemberBase imb = symbol as InterfaceMemberBase;
                                if (imb == null || !imb.IsExplicitImpl) {
                                        Report.SymbolRelatedToPreviousError (this);
                                        Report.Error (542, symbol.Location, "`{0}': member names cannot be the same as their enclosing type",
                                                symbol.GetSignatureForError ());
                                        return false;
                                }
                        }

                        return base.AddToContainer (symbol, name);
                }

                public override void VerifyMembers ()
                {
                        base.VerifyMembers ();

                        if ((events != null) && Report.WarningLevel >= 3) {
                                foreach (Event e in events){
                                        // Note: The event can be assigned from same class only, so we can report
                                        // this warning for all accessibility modes
                                        if ((e.caching_flags & Flags.IsUsed) == 0)
                                                Report.Warning (67, 3, e.Location, "The event `{0}' is never used", e.GetSignatureForError ());
                                }
                        }
                }

                public override void ApplyAttributeBuilder (Attribute a, CustomAttributeBuilder cb, PredefinedAttributes pa)
                {
                        if (a.IsValidSecurityAttribute ()) {
                                if (declarative_security == null)
                                        declarative_security = new ListDictionary ();

                                a.ExtractSecurityPermissionSet (declarative_security);
                                return;
                        }

                        if (a.Type == pa.StructLayout) {
                                PartialContainer.HasStructLayout = true;

                                if (a.GetLayoutKindValue () == LayoutKind.Explicit)
                                        PartialContainer.HasExplicitLayout = true;
                        }

                        base.ApplyAttributeBuilder (a, cb, pa);
                }

                /// <summary>
                /// Defines the default constructors 
                /// </summary>
                protected void DefineDefaultConstructor (bool is_static)
                {
                        // The default instance constructor is public
                        // If the class is abstract, the default constructor is protected
                        // The default static constructor is private

                        int mods;
                        if (is_static) {
                                mods = Modifiers.STATIC | Modifiers.PRIVATE;
                        } else {
                                mods = ((ModFlags & Modifiers.ABSTRACT) != 0) ? Modifiers.PROTECTED : Modifiers.PUBLIC;
                        }

                        Constructor c = new Constructor (this, MemberName.Name, mods,
                                null, ParametersCompiled.EmptyReadOnlyParameters,
                                new GeneratedBaseInitializer (Location),
                                Location);
                        
                        AddConstructor (c);
                        c.Block = new ToplevelBlock (ParametersCompiled.EmptyReadOnlyParameters, Location);
                }

                public override bool Define ()
                {
                        CheckProtectedModifier ();

                        base.Define ();

                        if (default_static_constructor != null)
                                default_static_constructor.Define ();

                        return true;
                }

                public override void Emit ()
                {
                        if (default_static_constructor == null && PartialContainer.HasStaticFieldInitializer) {
                                DefineDefaultConstructor (true);
                                default_static_constructor.Define ();
                        }

                        base.Emit ();

                        if (declarative_security != null) {
                                foreach (DictionaryEntry de in declarative_security) {
                                        TypeBuilder.AddDeclarativeSecurity ((SecurityAction)de.Key, (PermissionSet)de.Value);
                                }
                        }
                }

                public override ExtensionMethodGroupExpr LookupExtensionMethod (Type extensionType, string name, Location loc)
                {
                        return NamespaceEntry.LookupExtensionMethod (extensionType, this, name, loc);
                }

                protected override TypeAttributes TypeAttr {
                        get {
                                if (default_static_constructor == null)
                                        return base.TypeAttr | TypeAttributes.BeforeFieldInit;

                                return base.TypeAttr;
                        }
                }
        }


        // TODO: should be sealed
        public class Class : ClassOrStruct {
                const int AllowedModifiers =
                        Modifiers.NEW |
                        Modifiers.PUBLIC |
                        Modifiers.PROTECTED |
                        Modifiers.INTERNAL |
                        Modifiers.PRIVATE |
                        Modifiers.ABSTRACT |
                        Modifiers.SEALED |
                        Modifiers.STATIC |
                        Modifiers.UNSAFE;

                public const TypeAttributes StaticClassAttribute = TypeAttributes.Abstract | TypeAttributes.Sealed;

                public Class (NamespaceEntry ns, DeclSpace parent, MemberName name, int mod,
                              Attributes attrs)
                        : base (ns, parent, name, attrs, Kind.Class)
                {
                        int accmods = Parent.Parent == null ? Modifiers.INTERNAL : Modifiers.PRIVATE;
                        this.ModFlags = Modifiers.Check (AllowedModifiers, mod, accmods, Location);

                        if (IsStatic && RootContext.Version == LanguageVersion.ISO_1) {
                                Report.FeatureIsNotAvailable (Location, "static classes");
                        }
                }

                public override void AddBasesForPart (DeclSpace part, ArrayList bases)
                {
                        if (part.Name == "System.Object")
                                Report.Error (537, part.Location,
                                        "The class System.Object cannot have a base class or implement an interface.");
                        base.AddBasesForPart (part, bases);
                }

                public override void ApplyAttributeBuilder (Attribute a, CustomAttributeBuilder cb, PredefinedAttributes pa)
                {
                        if (a.Type == pa.AttributeUsage) {
                                if (!TypeManager.IsAttributeType (BaseType) &&
                                        TypeBuilder.FullName != "System.Attribute") {
                                        Report.Error (641, a.Location, "Attribute `{0}' is only valid on classes derived from System.Attribute", a.GetSignatureForError ());
                                }
                        }

                        if (a.Type == pa.Conditional && !TypeManager.IsAttributeType (BaseType)) {
                                Report.Error (1689, a.Location, "Attribute `System.Diagnostics.ConditionalAttribute' is only valid on methods or attribute classes");
                                return;
                        }

                        if (a.Type == pa.ComImport && !attributes.Contains (pa.Guid)) {
                                a.Error_MissingGuidAttribute ();
                                return;
                        }

                        if (a.Type == pa.Extension) {
                                a.Error_MisusedExtensionAttribute ();
                                return;
                        }

                        if (AttributeTester.IsAttributeExcluded (a.Type, Location))
                                return;

                        base.ApplyAttributeBuilder (a, cb, pa);
                }

                public override AttributeTargets AttributeTargets {
                        get {
                                return AttributeTargets.Class;
                        }
                }

                protected override void DefineContainerMembers (MemberCoreArrayList list)
                {
                        if (list == null)
                                return;

                        if (!IsStatic) {
                                base.DefineContainerMembers (list);
                                return;
                        }

                        foreach (MemberCore m in list) {
                                if (m is Operator) {
                                        Report.Error (715, m.Location, "`{0}': Static classes cannot contain user-defined operators", m.GetSignatureForError ());
                                        continue;
                                }

                                if (m is Destructor) {
                                        Report.Error (711, m.Location, "`{0}': Static classes cannot contain destructor", GetSignatureForError ());
                                        continue;
                                }

                                if (m is Indexer) {
                                        Report.Error (720, m.Location, "`{0}': cannot declare indexers in a static class", m.GetSignatureForError ());
                                        continue;
                                }

                                if ((m.ModFlags & Modifiers.STATIC) != 0 || m is Enum || m is Delegate)
                                        continue;

                                if (m is Constructor) {
                                        Report.Error (710, m.Location, "`{0}': Static classes cannot have instance constructors", GetSignatureForError ());
                                        continue;
                                }

                                Method method = m as Method;
                                if (method != null && method.Parameters.HasExtensionMethodType) {
                                        Report.Error (1105, m.Location, "`{0}': Extension methods must be declared static", m.GetSignatureForError ());
                                        continue;
                                }

                                Report.Error (708, m.Location, "`{0}': cannot declare instance members in a static class", m.GetSignatureForError ());
                        }

                        base.DefineContainerMembers (list);
                }

                public override bool Define ()
                {
                        if ((ModFlags & Modifiers.ABSTRACT) == Modifiers.ABSTRACT && (ModFlags & (Modifiers.SEALED | Modifiers.STATIC)) != 0) {
                                Report.Error (418, Location, "`{0}': an abstract class cannot be sealed or static", GetSignatureForError ());
                        }

                        if ((ModFlags & (Modifiers.SEALED | Modifiers.STATIC)) == (Modifiers.SEALED | Modifiers.STATIC)) {
                                Report.Error (441, Location, "`{0}': a class cannot be both static and sealed", GetSignatureForError ());
                        }

                        return base.Define ();
                }

                protected override bool DoDefineMembers ()
                {
                        if (InstanceConstructors == null && !IsStatic)
                                DefineDefaultConstructor (false);

                        return base.DoDefineMembers ();
                }

                public override void Emit ()
                {
                        base.Emit ();

                        if ((ModFlags & Modifiers.METHOD_EXTENSION) != 0)
                                PredefinedAttributes.Get.Extension.EmitAttribute (TypeBuilder);
                }

                protected override TypeExpr[] ResolveBaseTypes (out TypeExpr base_class)
                {
                        TypeExpr[] ifaces = base.ResolveBaseTypes (out base_class);

                        if (base_class == null) {
                                if (RootContext.StdLib)
                                        base_class = TypeManager.system_object_expr;
                                else if (Name != "System.Object")
                                        base_class = TypeManager.system_object_expr;
                        } else {
                                if (Kind == Kind.Class && base_class is TypeParameterExpr){
                                        Report.Error (
                                                689, base_class.Location,
                                                "Cannot derive from `{0}' because it is a type parameter",
                                                base_class.GetSignatureForError ());
                                        return ifaces;
                                }

                                if (IsGeneric && TypeManager.IsAttributeType (base_class.Type)) {
                                        Report.Error (698, base_class.Location,
                                                "A generic type cannot derive from `{0}' because it is an attribute class",
                                                base_class.GetSignatureForError ());
                                }

                                if (base_class.IsSealed){
                                        Report.SymbolRelatedToPreviousError (base_class.Type);
                                        if (base_class.Type.IsAbstract) {
                                                Report.Error (709, Location, "`{0}': Cannot derive from static class `{1}'",
                                                        GetSignatureForError (), TypeManager.CSharpName (base_class.Type));
                                        } else {
                                                Report.Error (509, Location, "`{0}': cannot derive from sealed type `{1}'",
                                                        GetSignatureForError (), TypeManager.CSharpName (base_class.Type));
                                        }
                                        return ifaces;
                                }

                                if (!base_class.CanInheritFrom ()){
                                        Report.Error (644, Location, "`{0}' cannot derive from special class `{1}'",
                                                GetSignatureForError (), base_class.GetSignatureForError ());
                                        return ifaces;
                                }

                                if (!IsAccessibleAs (base_class.Type)) {
                                        Report.SymbolRelatedToPreviousError (base_class.Type);
                                        Report.Error (60, Location, "Inconsistent accessibility: base class `{0}' is less accessible than class `{1}'", 
                                                TypeManager.CSharpName (base_class.Type), GetSignatureForError ());
                                }
                        }

                        if (PartialContainer.IsStaticClass) {
                                if (base_class.Type != TypeManager.object_type) {
                                        Report.Error (713, Location, "Static class `{0}' cannot derive from type `{1}'. Static classes must derive from object",
                                                GetSignatureForError (), base_class.GetSignatureForError ());
                                        return ifaces;
                                }

                                if (ifaces != null) {
                                        foreach (TypeExpr t in ifaces)
                                                Report.SymbolRelatedToPreviousError (t.Type);
                                        Report.Error (714, Location, "Static class `{0}' cannot implement interfaces", GetSignatureForError ());
                                }
                        }

                        return ifaces;
                }

                /// Search for at least one defined condition in ConditionalAttribute of attribute class
                /// Valid only for attribute classes.
                public bool IsExcluded ()
                {
                        if ((caching_flags & Flags.Excluded_Undetected) == 0)
                                return (caching_flags & Flags.Excluded) != 0;

                        caching_flags &= ~Flags.Excluded_Undetected;

                        if (OptAttributes == null)
                                return false;

                        Attribute[] attrs = OptAttributes.SearchMulti (PredefinedAttributes.Get.Conditional);
                        if (attrs == null)
                                return false;

                        foreach (Attribute a in attrs) {
                                string condition = a.GetConditionalAttributeValue ();
                                if (Location.CompilationUnit.IsConditionalDefined (condition))
                                        return false;
                        }

                        caching_flags |= Flags.Excluded;
                        return true;
                }

                bool IsStatic {
                        get {
                                return (ModFlags & Modifiers.STATIC) != 0;
                        }
                }

                //
                // FIXME: How do we deal with the user specifying a different
                // layout?
                //
                protected override TypeAttributes TypeAttr {
                        get {
                                TypeAttributes ta = base.TypeAttr | TypeAttributes.AutoLayout | TypeAttributes.Class;
                                if (IsStatic)
                                        ta |= StaticClassAttribute;
                                return ta;
                        }
                }
        }

        public sealed class Struct : ClassOrStruct {

                bool is_unmanaged, has_unmanaged_check_done;

                // <summary>
                //   Modifiers allowed in a struct declaration
                // </summary>
                const int AllowedModifiers =
                        Modifiers.NEW       |
                        Modifiers.PUBLIC    |
                        Modifiers.PROTECTED |
                        Modifiers.INTERNAL  |
                        Modifiers.UNSAFE    |
                        Modifiers.PRIVATE;

                public Struct (NamespaceEntry ns, DeclSpace parent, MemberName name,
                               int mod, Attributes attrs)
                        : base (ns, parent, name, attrs, Kind.Struct)
                {
                        int accmods;
                        
                        if (parent.Parent == null)
                                accmods = Modifiers.INTERNAL;
                        else
                                accmods = Modifiers.PRIVATE;
                        
                        this.ModFlags = Modifiers.Check (AllowedModifiers, mod, accmods, Location);

                        this.ModFlags |= Modifiers.SEALED;
                }

                public override void ApplyAttributeBuilder (Attribute a, CustomAttributeBuilder cb, PredefinedAttributes pa)
                {
                        base.ApplyAttributeBuilder (a, cb, pa);

                        //
                        // When struct constains fixed fixed and struct layout has explicitly
                        // set CharSet, its value has to be propagated to compiler generated
                        // fixed field types
                        //
                        if (a.Type == pa.StructLayout && Fields != null && a.HasField ("CharSet")) {
                                for (int i = 0; i < Fields.Count; ++i) {
                                        FixedField ff = Fields [i] as FixedField;
                                        if (ff != null)
                                                ff.SetCharSet (TypeBuilder.Attributes);
                                }
                        }
                }

                public override AttributeTargets AttributeTargets {
                        get {
                                return AttributeTargets.Struct;
                        }
                }

                public override bool IsUnmanagedType ()
                {
                        if (fields == null)
                                return true;

                        if (requires_delayed_unmanagedtype_check)
                                return true;

                        if (has_unmanaged_check_done)
                                return is_unmanaged;

                        has_unmanaged_check_done = true;

                        foreach (FieldBase f in fields) {
                                if ((f.ModFlags & Modifiers.STATIC) != 0)
                                        continue;

                                // It can happen when recursive unmanaged types are defined
                                // struct S { S* s; }
                                Type mt = f.MemberType;
                                if (mt == null) {
                                        has_unmanaged_check_done = false;
                                        requires_delayed_unmanagedtype_check = true;
                                        return true;
                                }

                                // TODO: Remove when pointer types are under mcs control
                                while (mt.IsPointer)
                                        mt = TypeManager.GetElementType (mt);
                                if (TypeManager.IsEqual (mt, TypeBuilder))
                                        continue;

                                if (TypeManager.IsUnmanagedType (mt))
                                        continue;

                                return false;
                        }

                        is_unmanaged = true;
                        return true;
                }

                protected override TypeExpr[] ResolveBaseTypes (out TypeExpr base_class)
                {
                        TypeExpr[] ifaces = base.ResolveBaseTypes (out base_class);
                        //
                        // If we are compiling our runtime,
                        // and we are defining ValueType, then our
                        // base is `System.Object'.
                        //
                        if (base_class == null) {
                                if (!RootContext.StdLib && Name == "System.ValueType")
                                        base_class = TypeManager.system_object_expr;
                                else
                                        base_class = TypeManager.system_valuetype_expr;
                        }

                        return ifaces;
                }

                //
                // FIXME: Allow the user to specify a different set of attributes
                // in some cases (Sealed for example is mandatory for a class,
                // but what SequentialLayout can be changed
                //
                protected override TypeAttributes TypeAttr {
                        get {
                                const TypeAttributes DefaultTypeAttributes =
                                        TypeAttributes.SequentialLayout |
                                        TypeAttributes.Sealed;

                                return base.TypeAttr | DefaultTypeAttributes;
                        }
                }

                public override void RegisterFieldForInitialization (MemberCore field, FieldInitializer expression)
                {
                        if ((field.ModFlags & Modifiers.STATIC) == 0) {
                                Report.Error (573, field.Location, "`{0}': Structs cannot have instance field initializers",
                                        field.GetSignatureForError ());
                                return;
                        }
                        base.RegisterFieldForInitialization (field, expression);
                }

        }

        /// <summary>
        ///   Interfaces
        /// </summary>
        public sealed class Interface : TypeContainer, IMemberContainer {

                /// <summary>
                ///   Modifiers allowed in a class declaration
                /// </summary>
                public const int AllowedModifiers =
                        Modifiers.NEW       |
                        Modifiers.PUBLIC    |
                        Modifiers.PROTECTED |
                        Modifiers.INTERNAL  |
                        Modifiers.UNSAFE    |
                        Modifiers.PRIVATE;

                public Interface (NamespaceEntry ns, DeclSpace parent, MemberName name, int mod,
                                  Attributes attrs)
                        : base (ns, parent, name, attrs, Kind.Interface)
                {
                        int accmods;

                        if (parent.Parent == null)
                                accmods = Modifiers.INTERNAL;
                        else
                                accmods = Modifiers.PRIVATE;

                        this.ModFlags = Modifiers.Check (AllowedModifiers, mod, accmods, name.Location);
                }

                public override void ApplyAttributeBuilder (Attribute a, CustomAttributeBuilder cb, PredefinedAttributes pa)
                {
                        if (a.Type == pa.ComImport && !attributes.Contains (pa.Guid)) {
                                a.Error_MissingGuidAttribute ();
                                return;
                        }

                        base.ApplyAttributeBuilder (a, cb, pa);
                }


                public override AttributeTargets AttributeTargets {
                        get {
                                return AttributeTargets.Interface;
                        }
                }

                protected override TypeAttributes TypeAttr {
                        get {
                                const TypeAttributes DefaultTypeAttributes =
                                        TypeAttributes.AutoLayout |
                                        TypeAttributes.Abstract |
                                        TypeAttributes.Interface;

                                return base.TypeAttr | DefaultTypeAttributes;
                        }
                }

                protected override bool VerifyClsCompliance ()
                {
                        if (!base.VerifyClsCompliance ())
                                return false;

                        if (ifaces != null) {
                                foreach (Type t in ifaces) {
                                        if (AttributeTester.IsClsCompliant (t))
                                                continue;

                                        Report.SymbolRelatedToPreviousError (t);
                                        Report.Warning (3027, 1, Location, "`{0}' is not CLS-compliant because base interface `{1}' is not CLS-compliant",
                                                GetSignatureForError (), TypeManager.CSharpName (t));
                                }
                        }

                        return true;
                }
        }

        // It is used as a base class for all property based members
        // This includes properties, indexers, and events
        public abstract class PropertyBasedMember : InterfaceMemberBase
        {
                public PropertyBasedMember (DeclSpace parent, GenericMethod generic,
                        FullNamedExpression type, int mod, int allowed_mod,
                        MemberName name, Attributes attrs)
                        : base (parent, generic, type, mod, allowed_mod, name, attrs)
                {
                }

                protected override bool VerifyClsCompliance ()
                {
                        if (!base.VerifyClsCompliance ())
                                return false;

                        if (!AttributeTester.IsClsCompliant (MemberType)) {
                                Report.Warning (3003, 1, Location, "Type of `{0}' is not CLS-compliant",
                                        GetSignatureForError ());
                        }
                        return true;
                }

        }


        public abstract class MethodCore : InterfaceMemberBase
        {
                public readonly ParametersCompiled Parameters;
                protected ToplevelBlock block;

                public MethodCore (DeclSpace parent, GenericMethod generic,
                        FullNamedExpression type, int mod, int allowed_mod,
                        MemberName name, Attributes attrs, ParametersCompiled parameters)
                        : base (parent, generic, type, mod, allowed_mod, name, attrs)
                {
                        Parameters = parameters;
                }

                //
                //  Returns the System.Type array for the parameters of this method
                //
                public Type [] ParameterTypes {
                        get {
                                return Parameters.Types;
                        }
                }

                public ParametersCompiled ParameterInfo {
                        get {
                                return Parameters;
                        }
                }
                
                public ToplevelBlock Block {
                        get {
                                return block;
                        }

                        set {
                                block = value;
                        }
                }

                public CallingConventions CallingConventions {
                        get {
                                CallingConventions cc = Parameters.CallingConvention;
                                if (!IsInterface)
                                        if ((ModFlags & Modifiers.STATIC) == 0)
                                                cc |= CallingConventions.HasThis;

                                // FIXME: How is `ExplicitThis' used in C#?
                        
                                return cc;
                        }
                }

                protected override bool CheckBase ()
                {
                        // Check whether arguments were correct.
                        if (!DefineParameters (Parameters))
                                return false;

                        return base.CheckBase ();
                }

                //
                // Returns a string that represents the signature for this 
                // member which should be used in XML documentation.
                //
                public override string GetDocCommentName (DeclSpace ds)
                {
                        return DocUtil.GetMethodDocCommentName (this, Parameters, ds);
                }

                //
                // Raised (and passed an XmlElement that contains the comment)
                // when GenerateDocComment is writing documentation expectedly.
                //
                // FIXME: with a few effort, it could be done with XmlReader,
                // that means removal of DOM use.
                //
                internal override void OnGenerateDocComment (XmlElement el)
                {
                        DocUtil.OnMethodGenerateDocComment (this, el);
                }

                //
                //   Represents header string for documentation comment.
                //
                public override string DocCommentHeader 
                {
                        get { return "M:"; }
                }

                public override bool EnableOverloadChecks (MemberCore overload)
                {
                        if (overload is MethodCore || overload is AbstractPropertyEventMethod) {
                                caching_flags |= Flags.MethodOverloadsExist;
                                return true;
                        }

                        return base.EnableOverloadChecks (overload);
                }

                protected override bool VerifyClsCompliance ()
                {
                        if (!base.VerifyClsCompliance ())
                                return false;

                        if (Parameters.HasArglist) {
                                Report.Warning (3000, 1, Location, "Methods with variable arguments are not CLS-compliant");
                        }

                        if (!AttributeTester.IsClsCompliant (MemberType)) {
                                Report.Warning (3002, 1, Location, "Return type of `{0}' is not CLS-compliant",
                                        GetSignatureForError ());
                        }

                        Parameters.VerifyClsCompliance ();
                        return true;
                }

        }

        public abstract class InterfaceMemberBase : MemberBase {
                //
                // Whether this is an interface member.
                //
                public bool IsInterface;

                //
                // If true, this is an explicit interface implementation
                //
                public bool IsExplicitImpl;

                protected bool is_external_implementation;

                //
                // The interface type we are explicitly implementing
                //
                public Type InterfaceType;

                //
                // The method we're overriding if this is an override method.
                //
                protected MethodInfo base_method;

                readonly int explicit_mod_flags;
                public MethodAttributes flags;

                public InterfaceMemberBase (DeclSpace parent, GenericMethod generic,
                                   FullNamedExpression type, int mod, int allowed_mod,
                                   MemberName name, Attributes attrs)
                        : base (parent, generic, type, mod, allowed_mod, Modifiers.PRIVATE,
                                name, attrs)
                {
                        IsInterface = parent.PartialContainer.Kind == Kind.Interface;
                        IsExplicitImpl = (MemberName.Left != null);
                        explicit_mod_flags = mod;
                }
                
                protected override bool CheckBase ()
                {
                        if (!base.CheckBase ())
                                return false;

                        if ((caching_flags & Flags.MethodOverloadsExist) != 0)
                                CheckForDuplications ();
                        
                        if (IsExplicitImpl)
                                return true;

                        // Is null for System.Object while compiling corlib and base interfaces
                        if (Parent.PartialContainer.BaseCache == null) {
                                if ((ModFlags & Modifiers.NEW) != 0) {
                                        Report.Warning (109, 4, Location, "The member `{0}' does not hide an inherited member. The new keyword is not required", GetSignatureForError ());
                                }
                                return true;
                        }

                        Type base_ret_type = null;
                        base_method = FindOutBaseMethod (ref base_ret_type);

                        // method is override
                        if (base_method != null) {
                                if (!CheckMethodAgainstBase (base_ret_type))
                                        return false;

                                if ((ModFlags & Modifiers.OVERRIDE) != 0) {
                                        ObsoleteAttribute oa = AttributeTester.GetMethodObsoleteAttribute (base_method);
                                        if (oa != null) {
                                                if (OptAttributes == null || !OptAttributes.Contains (PredefinedAttributes.Get.Obsolete)) {
                                                        Report.SymbolRelatedToPreviousError (base_method);
                                                                Report.Warning (672, 1, Location, "Member `{0}' overrides obsolete member `{1}'. Add the Obsolete attribute to `{0}'",
                                                                        GetSignatureForError (), TypeManager.CSharpSignature (base_method));
                                                }
                                        } else {
                                                if (OptAttributes != null && OptAttributes.Contains (PredefinedAttributes.Get.Obsolete)) {
                                                        Report.SymbolRelatedToPreviousError (base_method);
                                                        Report.Warning (809, 1, Location, "Obsolete member `{0}' overrides non-obsolete member `{1}'",
                                                                GetSignatureForError (), TypeManager.CSharpSignature (base_method));
                                                }
                                        }
                                }
                                return true;
                        }

                        MemberInfo conflict_symbol = Parent.PartialContainer.FindBaseMemberWithSameName (Name, !((this is Event) || (this is Property)));
                        if ((ModFlags & Modifiers.OVERRIDE) != 0) {
                                if (conflict_symbol != null) {
                                        Report.SymbolRelatedToPreviousError (conflict_symbol);
                                        if (this is Event)
                                                Report.Error (72, Location, "`{0}': cannot override because `{1}' is not an event", GetSignatureForError (), TypeManager.GetFullNameSignature (conflict_symbol));
                                        else if (this is PropertyBase)
                                                Report.Error (544, Location, "`{0}': cannot override because `{1}' is not a property", GetSignatureForError (), TypeManager.GetFullNameSignature (conflict_symbol));
                                        else
                                                Report.Error (505, Location, "`{0}': cannot override because `{1}' is not a method", GetSignatureForError (), TypeManager.GetFullNameSignature (conflict_symbol));
                                } else {
                                        Report.Error (115, Location, "`{0}' is marked as an override but no suitable {1} found to override",
                                                GetSignatureForError (), SimpleName.GetMemberType (this));
                                }
                                return false;
                        }

                        if (conflict_symbol == null) {
                                if ((ModFlags & Modifiers.NEW) != 0) {
                                        Report.Warning (109, 4, Location, "The member `{0}' does not hide an inherited member. The new keyword is not required", GetSignatureForError ());
                                }
                                return true;
                        }

                        if ((ModFlags & Modifiers.NEW) == 0) {
                                if (this is MethodOrOperator && conflict_symbol.MemberType == MemberTypes.Method)
                                        return true;

                                Report.SymbolRelatedToPreviousError (conflict_symbol);
                                Report.Warning (108, 2, Location, "`{0}' hides inherited member `{1}'. Use the new keyword if hiding was intended",
                                        GetSignatureForError (), TypeManager.GetFullNameSignature (conflict_symbol));
                        }

                        return true;
                }

                protected virtual bool CheckForDuplications ()
                {
                        return Parent.MemberCache.CheckExistingMembersOverloads (
                                this, GetFullName (MemberName), ParametersCompiled.EmptyReadOnlyParameters);
                }

                //
                // Performs various checks on the MethodInfo `mb' regarding the modifier flags
                // that have been defined.
                //
                // `name' is the user visible name for reporting errors (this is used to
                // provide the right name regarding method names and properties)
                //
                bool CheckMethodAgainstBase (Type base_method_type)
                {
                        bool ok = true;

                        if ((ModFlags & Modifiers.OVERRIDE) != 0){
                                if (!(base_method.IsAbstract || base_method.IsVirtual)){
                                        Report.SymbolRelatedToPreviousError (base_method);
                                        Report.Error (506, Location,
                                                "`{0}': cannot override inherited member `{1}' because it is not marked virtual, abstract or override",
                                                 GetSignatureForError (), TypeManager.CSharpSignature (base_method));
                                        ok = false;
                                }
                                
                                // Now we check that the overriden method is not final
                                
                                if (base_method.IsFinal) {
                                        Report.SymbolRelatedToPreviousError (base_method);
                                        Report.Error (239, Location, "`{0}': cannot override inherited member `{1}' because it is sealed",
                                                              GetSignatureForError (), TypeManager.CSharpSignature (base_method));
                                        ok = false;
                                }
                                //
                                // Check that the permissions are not being changed
                                //
                                MethodAttributes thisp = flags & MethodAttributes.MemberAccessMask;
                                MethodAttributes base_classp = base_method.Attributes & MethodAttributes.MemberAccessMask;

                                if (!CheckAccessModifiers (thisp, base_classp, base_method)) {
                                        Error_CannotChangeAccessModifiers (Location, base_method, base_classp, null);
                                        ok = false;
                                }

                                if (!TypeManager.IsEqual (MemberType, TypeManager.TypeToCoreType (base_method_type))) {
                                        Report.SymbolRelatedToPreviousError (base_method);
                                        if (this is PropertyBasedMember) {
                                                Report.Error (1715, Location, "`{0}': type must be `{1}' to match overridden member `{2}'", 
                                                        GetSignatureForError (), TypeManager.CSharpName (base_method_type), TypeManager.CSharpSignature (base_method));
                                        }
                                        else {
                                                Report.Error (508, Location, "`{0}': return type must be `{1}' to match overridden member `{2}'",
                                                        GetSignatureForError (), TypeManager.CSharpName (base_method_type), TypeManager.CSharpSignature (base_method));
                                        }
                                        ok = false;
                                }
                        }

                        if ((ModFlags & Modifiers.NEW) == 0) {
                                if ((ModFlags & Modifiers.OVERRIDE) == 0) {
                                        ModFlags |= Modifiers.NEW;
                                        Report.SymbolRelatedToPreviousError (base_method);
                                        if (!IsInterface && (base_method.IsVirtual || base_method.IsAbstract)) {
                                                Report.Warning (114, 2, Location, "`{0}' hides inherited member `{1}'. To make the current member override that implementation, add the override keyword. Otherwise add the new keyword",
                                                        GetSignatureForError (), TypeManager.CSharpSignature (base_method));
                                        } else {
                                                Report.Warning (108, 2, Location, "`{0}' hides inherited member `{1}'. Use the new keyword if hiding was intended",
                                                        GetSignatureForError (), TypeManager.CSharpSignature (base_method));
                                        }
                                }
                        } else {
                                if (base_method.IsAbstract && !IsInterface) {
                                        Report.SymbolRelatedToPreviousError (base_method);
                                        Report.Error (533, Location, "`{0}' hides inherited abstract member `{1}'",
                                                GetSignatureForError (), TypeManager.CSharpSignature (base_method));
                                        return ok = false;
                                }
                        }

                        return ok;
                }
                
                protected bool CheckAccessModifiers (MethodAttributes thisp, MethodAttributes base_classp, MethodInfo base_method)
                {
                        if ((base_classp & MethodAttributes.FamORAssem) == MethodAttributes.FamORAssem){
                                //
                                // when overriding protected internal, the method can be declared
                                // protected internal only within the same assembly or assembly
                                // which has InternalsVisibleTo
                                //
                                if ((thisp & MethodAttributes.FamORAssem) == MethodAttributes.FamORAssem){
                                        return TypeManager.IsThisOrFriendAssembly (base_method.DeclaringType.Assembly);
                                } else if ((thisp & MethodAttributes.Family) != MethodAttributes.Family) {
                                        //
                                        // if it's not "protected internal", it must be "protected"
                                        //

                                        return false;
                                } else if (Parent.TypeBuilder.Assembly == base_method.DeclaringType.Assembly) {
                                        //
                                        // protected within the same assembly - an error
                                        //
                                        return false;
                                } else if ((thisp & ~(MethodAttributes.Family | MethodAttributes.FamORAssem)) != 
                                           (base_classp & ~(MethodAttributes.Family | MethodAttributes.FamORAssem))) {
                                        //
                                        // protected ok, but other attributes differ - report an error
                                        //
                                        return false;
                                }
                                return true;
                        } else {
                                return (thisp == base_classp);
                        }
                }

                public override bool Define ()
                {
                        if (IsInterface) {
                                ModFlags = Modifiers.PUBLIC | Modifiers.ABSTRACT |
                                        Modifiers.VIRTUAL | (ModFlags & (Modifiers.UNSAFE | Modifiers.NEW));

                                flags = MethodAttributes.Public |
                                        MethodAttributes.Abstract |
                                        MethodAttributes.HideBySig |
                                        MethodAttributes.NewSlot |
                                        MethodAttributes.Virtual;
                        } else {
                                Parent.PartialContainer.MethodModifiersValid (this);

                                flags = Modifiers.MethodAttr (ModFlags);
                        }

                        if (IsExplicitImpl) {
                                TypeExpr iface_texpr = MemberName.Left.GetTypeExpression ().ResolveAsTypeTerminal (this, false);
                                if (iface_texpr == null)
                                        return false;

                                if ((ModFlags & Modifiers.PARTIAL) != 0) {
                                        Report.Error (754, Location, "A partial method `{0}' cannot explicitly implement an interface",
                                                GetSignatureForError ());
                                }

                                InterfaceType = iface_texpr.Type;

                                if (!InterfaceType.IsInterface) {
                                        Report.SymbolRelatedToPreviousError (InterfaceType);
                                        Report.Error (538, Location, "The type `{0}' in explicit interface declaration is not an interface",
                                                TypeManager.CSharpName (InterfaceType));
                                } else {
                                        Parent.PartialContainer.VerifyImplements (this);
                                }

                                Modifiers.Check (Modifiers.AllowedExplicitImplFlags, explicit_mod_flags, 0, Location);
                        }

                        return base.Define ();
                }

                protected bool DefineParameters (ParametersCompiled parameters)
                {
                        IResolveContext rc = GenericMethod == null ? this : (IResolveContext)ds;

                        if (!parameters.Resolve (rc))
                                return false;

                        bool error = false;
                        for (int i = 0; i < parameters.Count; ++i) {
                                Parameter p = parameters [i];

                                if (p.HasDefaultValue && (IsExplicitImpl || this is Operator || (this is Indexer && parameters.Count == 1)))
                                        p.Warning_UselessOptionalParameter ();

                                if (p.CheckAccessibility (this))
                                        continue;

                                Type t = parameters.Types [i];
                                Report.SymbolRelatedToPreviousError (t);
                                if (this is Indexer)
                                        Report.Error (55, Location,
                                                      "Inconsistent accessibility: parameter type `{0}' is less accessible than indexer `{1}'",
                                                      TypeManager.CSharpName (t), GetSignatureForError ());
                                else if (this is Operator)
                                        Report.Error (57, Location,
                                                      "Inconsistent accessibility: parameter type `{0}' is less accessible than operator `{1}'",
                                                      TypeManager.CSharpName (t), GetSignatureForError ());
                                else
                                        Report.Error (51, Location,
                                                "Inconsistent accessibility: parameter type `{0}' is less accessible than method `{1}'",
                                                TypeManager.CSharpName (t), GetSignatureForError ());
                                error = true;
                        }
                        return !error;
                }

                public override void Emit()
                {
                        // for extern static method must be specified either DllImport attribute or MethodImplAttribute.
                        // We are more strict than csc and report this as an error because SRE does not allow emit that
                        if ((ModFlags & Modifiers.EXTERN) != 0 && !is_external_implementation) {
                                if (this is Constructor) {
                                        Report.Error (824, Location,
                                                "Constructor `{0}' is marked `external' but has no external implementation specified", GetSignatureForError ());
                                } else {
                                        Report.Error (626, Location,
                                                "`{0}' is marked as an external but has no DllImport attribute. Consider adding a DllImport attribute to specify the external implementation",
                                                GetSignatureForError ());
                                }
                        }

                        base.Emit ();
                }

                public override bool EnableOverloadChecks (MemberCore overload)
                {
                        //
                        // Two members can differ in their explicit interface
                        // type parameter only
                        //
                        InterfaceMemberBase imb = overload as InterfaceMemberBase;
                        if (imb != null && imb.IsExplicitImpl) {
                                if (IsExplicitImpl) {
                                        caching_flags |= Flags.MethodOverloadsExist;
                                }
                                return true;
                        }

                        return IsExplicitImpl;
                }

                protected void Error_CannotChangeAccessModifiers (Location loc, MemberInfo base_method, MethodAttributes ma, string suffix)
                {
                        Report.SymbolRelatedToPreviousError (base_method);
                        string base_name = TypeManager.GetFullNameSignature (base_method);
                        string this_name = GetSignatureForError ();
                        if (suffix != null) {
                                base_name += suffix;
                                this_name += suffix;
                        }

                        Report.Error (507, loc, "`{0}': cannot change access modifiers when overriding `{1}' inherited member `{2}'",
                                this_name, Modifiers.GetDescription (ma), base_name);
                }

                protected static string Error722 {
                        get {
                                return "`{0}': static types cannot be used as return types";
                        }
                }

                /// <summary>
                /// Gets base method and its return type
                /// </summary>
                protected abstract MethodInfo FindOutBaseMethod (ref Type base_ret_type);

                //
                // The "short" name of this property / indexer / event.  This is the
                // name without the explicit interface.
                //
                public string ShortName 
                {
                        get { return MemberName.Name; }
                        set { SetMemberName (new MemberName (MemberName.Left, value, Location)); }
                }
                
                //
                // Returns full metadata method name
                //
                public string GetFullName (MemberName name)
                {
                        if (!IsExplicitImpl)
                                return name.Name;

                        //
                        // When dealing with explicit members a full interface type
                        // name is added to member name to avoid possible name conflicts
                        //
                        // We use CSharpName which gets us full name with benefit of
                        // replacing predefined names which saves some space and name
                        // is still unique
                        //
                        return TypeManager.CSharpName (InterfaceType) + "." + name.Name;
                }

                protected override bool VerifyClsCompliance ()
                {
                        if (!base.VerifyClsCompliance ()) {
                                if (IsInterface && HasClsCompliantAttribute && Parent.IsClsComplianceRequired ()) {
                                        Report.Warning (3010, 1, Location, "`{0}': CLS-compliant interfaces must have only CLS-compliant members", GetSignatureForError ());
                                }

                                if ((ModFlags & Modifiers.ABSTRACT) != 0 && Parent.TypeBuilder.IsClass && IsExposedFromAssembly () && Parent.IsClsComplianceRequired ()) {
                                        Report.Warning (3011, 1, Location, "`{0}': only CLS-compliant members can be abstract", GetSignatureForError ());
                                }
                                return false;
                        }

                        if (GenericMethod != null)
                                GenericMethod.VerifyClsCompliance ();

                        return true;
                }

                public override bool IsUsed 
                {
                        get { return IsExplicitImpl || base.IsUsed; }
                }

        }

        public abstract class MethodOrOperator : MethodCore, IMethodData
        {
                public MethodBuilder MethodBuilder;
                ReturnParameter return_attributes;
                ListDictionary declarative_security;
                protected MethodData MethodData;

                static string[] attribute_targets = new string [] { "method", "return" };

                protected MethodOrOperator (DeclSpace parent, GenericMethod generic, FullNamedExpression type, int mod,
                                int allowed_mod, MemberName name,
                                Attributes attrs, ParametersCompiled parameters)
                        : base (parent, generic, type, mod, allowed_mod, name,
                                        attrs, parameters)
                {
                }

                public override void ApplyAttributeBuilder (Attribute a, CustomAttributeBuilder cb, PredefinedAttributes pa)
                {
                        if (a.Target == AttributeTargets.ReturnValue) {
                                if (return_attributes == null)
                                        return_attributes = new ReturnParameter (MethodBuilder, Location);

                                return_attributes.ApplyAttributeBuilder (a, cb, pa);
                                return;
                        }

                        if (a.IsInternalMethodImplAttribute) {
                                is_external_implementation = true;
                        }

                        if (a.Type == pa.DllImport) {
                                const int extern_static = Modifiers.EXTERN | Modifiers.STATIC;
                                if ((ModFlags & extern_static) != extern_static) {
                                        Report.Error (601, a.Location, "The DllImport attribute must be specified on a method marked `static' and `extern'");
                                }
                                is_external_implementation = true;
                        }

                        if (a.IsValidSecurityAttribute ()) {
                                if (declarative_security == null)
                                        declarative_security = new ListDictionary ();
                                a.ExtractSecurityPermissionSet (declarative_security);
                                return;
                        }

                        if (MethodBuilder != null)
                                MethodBuilder.SetCustomAttribute (cb);
                }

                public override AttributeTargets AttributeTargets {
                        get {
                                return AttributeTargets.Method; 
                        }
                }

                protected override bool CheckForDuplications ()
                {
                        string name = GetFullName (MemberName);
                        if (MemberName.IsGeneric)
                                name = MemberName.MakeName (name, MemberName.TypeArguments);

                        return Parent.MemberCache.CheckExistingMembersOverloads (this, name, Parameters);
                }

                public virtual EmitContext CreateEmitContext (DeclSpace tc, ILGenerator ig)
                {
                        return new EmitContext (
                                this, tc, this.ds, Location, ig, MemberType, ModFlags, false);
                }

                protected override bool ResolveMemberType ()
                {
#if GMCS_SOURCE
                        if (GenericMethod != null) {
                                MethodBuilder = Parent.TypeBuilder.DefineMethod (GetFullName (MemberName), flags);
                                if (!GenericMethod.Define (this))
                                        return false;
                        }
#endif

                        return base.ResolveMemberType ();
                }

                public override bool Define ()
                {
                        if (!base.Define ())
                                return false;

                        if (!CheckBase ())
                                return false;

                        if (block != null && block.IsIterator && !(Parent is IteratorStorey)) {
                                //
                                // Current method is turned into automatically generated
                                // wrapper which creates an instance of iterator
                                //
                                Iterator.CreateIterator (this, Parent.PartialContainer, ModFlags);
                                ModFlags |= Modifiers.DEBUGGER_HIDDEN;
                        }

                        if (IsPartialDefinition) {
                                caching_flags &= ~Flags.Excluded_Undetected;
                                caching_flags |= Flags.Excluded;
                                // Add to member cache only when a partial method implementation is not there
                                if ((caching_flags & Flags.MethodOverloadsExist) == 0) {
                                        MethodBase mb = new PartialMethodDefinitionInfo (this);
                                        Parent.MemberCache.AddMember (mb, this);
                                        TypeManager.AddMethod (mb, this);
                                }

                                return true;
                        }

                        MethodData = new MethodData (
                                this, ModFlags, flags, this, MethodBuilder, GenericMethod, base_method);

                        if (!MethodData.Define (Parent.PartialContainer, GetFullName (MemberName)))
                                return false;
                                        
                        MethodBuilder = MethodData.MethodBuilder;

                        if (TypeManager.IsGenericMethod (MethodBuilder))
                                Parent.MemberCache.AddGenericMember (MethodBuilder, this);
                        
                        Parent.MemberCache.AddMember (MethodBuilder, this);

                        return true;
                }

                protected override void DoMemberTypeIndependentChecks ()
                {
                        base.DoMemberTypeIndependentChecks ();

                        CheckAbstractAndExtern (block != null);

                        if ((ModFlags & Modifiers.PARTIAL) != 0) {
                                for (int i = 0; i < Parameters.Count; ++i) {
                                        IParameterData p = Parameters.FixedParameters [i];
                                        if (p.ModFlags == Parameter.Modifier.OUT) {
                                                Report.Error (752, Location, "`{0}': A partial method parameters cannot use `out' modifier",
                                                        GetSignatureForError ());
                                        }

                                        if (p.HasDefaultValue && IsPartialImplementation)
                                                ((Parameter) p).Warning_UselessOptionalParameter ();
                                }
                        }
                }

                protected override void DoMemberTypeDependentChecks ()
                {
                        base.DoMemberTypeDependentChecks ();

                        if (!TypeManager.IsGenericParameter (MemberType)) {
                                if (MemberType.IsAbstract && MemberType.IsSealed) {
                                        Report.Error (722, Location, Error722, TypeManager.CSharpName (MemberType));
                                }
                        }
                }

                public override void Emit ()
                {
                        if ((ModFlags & Modifiers.COMPILER_GENERATED) != 0 && !Parent.IsCompilerGenerated)
                                PredefinedAttributes.Get.CompilerGenerated.EmitAttribute (MethodBuilder);
                        if ((ModFlags & Modifiers.DEBUGGER_HIDDEN) != 0)
                                PredefinedAttributes.Get.DebuggerHidden.EmitAttribute (MethodBuilder);

                        if (TypeManager.IsDynamicType (ReturnType)) {
                                return_attributes = new ReturnParameter (MethodBuilder, Location);
                                return_attributes.EmitPredefined (PredefinedAttributes.Get.Dynamic, Location);
                        }

                        if (OptAttributes != null)
                                OptAttributes.Emit ();

                        if (declarative_security != null) {
                                foreach (DictionaryEntry de in declarative_security) {
                                        MethodBuilder.AddDeclarativeSecurity ((SecurityAction)de.Key, (PermissionSet)de.Value);
                                }
                        }

                        if (MethodData != null)
                                MethodData.Emit (Parent);

                        base.Emit ();

                        Block = null;
                        MethodData = null;
                }

                protected void Error_ConditionalAttributeIsNotValid ()
                {
                        Report.Error (577, Location,
                                "Conditional not valid on `{0}' because it is a constructor, destructor, operator or explicit interface implementation",
                                GetSignatureForError ());
                }

                public bool IsPartialDefinition {
                        get {
                                return (ModFlags & Modifiers.PARTIAL) != 0 && Block == null;
                        }
                }

                public bool IsPartialImplementation {
                        get {
                                return (ModFlags & Modifiers.PARTIAL) != 0 && Block != null;
                        }
                }

                public override string[] ValidAttributeTargets {
                        get {
                                return attribute_targets;
                        }
                }

                #region IMethodData Members

                public Type ReturnType {
                        get {
                                return MemberType;
                        }
                }

                public MemberName MethodName {
                        get {
                                return MemberName;
                        }
                }

                /// <summary>
                /// Returns true if method has conditional attribute and the conditions is not defined (method is excluded).
                /// </summary>
                public bool IsExcluded () {
                        if ((caching_flags & Flags.Excluded_Undetected) == 0)
                                return (caching_flags & Flags.Excluded) != 0;

                        caching_flags &= ~Flags.Excluded_Undetected;

                        if (base_method == null) {
                                if (OptAttributes == null)
                                        return false;

                                Attribute[] attrs = OptAttributes.SearchMulti (PredefinedAttributes.Get.Conditional);

                                if (attrs == null)
                                        return false;

                                foreach (Attribute a in attrs) {
                                        string condition = a.GetConditionalAttributeValue ();
                                        if (condition == null)
                                                return false;

                                        if (Location.CompilationUnit.IsConditionalDefined (condition))
                                                return false;
                                }

                                caching_flags |= Flags.Excluded;
                                return true;
                        }

                        IMethodData md = TypeManager.GetMethod (TypeManager.DropGenericMethodArguments (base_method));
                        if (md == null) {
                                if (AttributeTester.IsConditionalMethodExcluded (base_method, Location)) {
                                        caching_flags |= Flags.Excluded;
                                        return true;
                                }
                                return false;
                        }

                        if (md.IsExcluded ()) {
                                caching_flags |= Flags.Excluded;
                                return true;
                        }
                        return false;
                }

                GenericMethod IMethodData.GenericMethod {
                        get {
                                return GenericMethod;
                        }
                }

                public virtual void EmitExtraSymbolInfo (SourceMethod source)
                { }

                #endregion

        }

        public class SourceMethod : IMethodDef
        {
                MethodBase method;
                SourceMethodBuilder builder;

                protected SourceMethod (DeclSpace parent, MethodBase method, ICompileUnit file)
                {
                        this.method = method;
                        
                        builder = SymbolWriter.OpenMethod (file, parent.NamespaceEntry.SymbolFileID, this);
                }

                public string Name {
                        get { return method.Name; }
                }

                public int Token {
                        get {
                                if (method is MethodBuilder)
                                        return ((MethodBuilder) method).GetToken ().Token;
                                else if (method is ConstructorBuilder)
                                        return ((ConstructorBuilder) method).GetToken ().Token;
                                else
                                        throw new NotSupportedException ();
                        }
                }

                public void CloseMethod ()
                {
                        SymbolWriter.CloseMethod ();
                }

                public void SetRealMethodName (string name)
                {
                        if (builder != null)
                                builder.SetRealMethodName (name);
                }

                public static SourceMethod Create (DeclSpace parent, MethodBase method, Block block)
                {
                        if (!SymbolWriter.HasSymbolWriter)
                                return null;
                        if (block == null)
                                return null;

                        Location start_loc = block.StartLocation;
                        if (start_loc.IsNull)
                                return null;

                        ICompileUnit compile_unit = start_loc.CompilationUnit;
                        if (compile_unit == null)
                                return null;

                        return new SourceMethod (parent, method, compile_unit);
                }
        }

        public class Method : MethodOrOperator {

                /// <summary>
                ///   Modifiers allowed in a class declaration
                /// </summary>
                const int AllowedModifiers =
                        Modifiers.NEW |
                        Modifiers.PUBLIC |
                        Modifiers.PROTECTED |
                        Modifiers.INTERNAL |
                        Modifiers.PRIVATE |
                        Modifiers.STATIC |
                        Modifiers.VIRTUAL |
                        Modifiers.SEALED |
                        Modifiers.OVERRIDE |
                        Modifiers.ABSTRACT |
                        Modifiers.UNSAFE |
                        Modifiers.EXTERN;

                const int AllowedInterfaceModifiers =
                        Modifiers.NEW | Modifiers.UNSAFE;

                public Method (DeclSpace parent, GenericMethod generic,
                               FullNamedExpression return_type, int mod,
                               MemberName name, ParametersCompiled parameters, Attributes attrs)
                        : base (parent, generic, return_type, mod,
                                parent.PartialContainer.Kind == Kind.Interface ? AllowedInterfaceModifiers : AllowedModifiers,
                                name, attrs, parameters)
                {
                }

                protected Method (DeclSpace parent, FullNamedExpression return_type, int mod, int amod,
                                        MemberName name, ParametersCompiled parameters, Attributes attrs)
                        : base (parent, null, return_type, mod, amod, name, attrs, parameters)
                {
                }
                
                public override string GetSignatureForError()
                {
                        return base.GetSignatureForError () + Parameters.GetSignatureForError ();
                }

                static void Error_DuplicateEntryPoint (Method b)
                {
                        Report.Error (17, b.Location,
                                "Program `{0}' has more than one entry point defined: `{1}'",
                                CodeGen.FileName, b.GetSignatureForError ());
                }

                bool IsEntryPoint ()
                {
                        if (ReturnType != TypeManager.void_type &&
                                ReturnType != TypeManager.int32_type)
                                return false;

                        if (Parameters.Count == 0)
                                return true;

                        if (Parameters.Count > 1)
                                return false;

                        Type t = Parameters.Types [0];
                        return t.IsArray && t.GetArrayRank () == 1 &&
                                        TypeManager.GetElementType (t) == TypeManager.string_type &&
                                        (Parameters[0].ModFlags & ~Parameter.Modifier.PARAMS) == Parameter.Modifier.NONE;
                }

                public override void ApplyAttributeBuilder (Attribute a, CustomAttributeBuilder cb, PredefinedAttributes pa)
                {
                        if (a.Type == pa.Conditional) {
                                if (IsExplicitImpl) {
                                        Error_ConditionalAttributeIsNotValid ();
                                        return;
                                }

                                if (ReturnType != TypeManager.void_type) {
                                        Report.Error (578, Location, "Conditional not valid on `{0}' because its return type is not void", GetSignatureForError ());
                                        return;
                                }

                                if ((ModFlags & Modifiers.OVERRIDE) != 0) {
                                        Report.Error (243, Location, "Conditional not valid on `{0}' because it is an override method", GetSignatureForError ());
                                        return;
                                }

                                if (IsInterface) {
                                        Report.Error (582, Location, "Conditional not valid on interface members");
                                        return;
                                }

                                if (MethodData.implementing != null) {
                                        Report.SymbolRelatedToPreviousError (MethodData.implementing.DeclaringType);
                                        Report.Error (629, Location, "Conditional member `{0}' cannot implement interface member `{1}'",
                                                GetSignatureForError (), TypeManager.CSharpSignature (MethodData.implementing));
                                        return;
                                }

                                for (int i = 0; i < Parameters.Count; ++i) {
                                        if (Parameters.FixedParameters [i].ModFlags == Parameter.Modifier.OUT) {
                                                Report.Error (685, Location, "Conditional method `{0}' cannot have an out parameter", GetSignatureForError ());
                                                return;
                                        }
                                }
                        }

                        if (a.Type == pa.Extension) {
                                a.Error_MisusedExtensionAttribute ();
                                return;
                        }

                        base.ApplyAttributeBuilder (a, cb, pa);
                }

                protected override bool CheckForDuplications ()
                {
                        if (!base.CheckForDuplications ())
                                return false;

                        ArrayList ar = Parent.PartialContainer.Properties;
                        if (ar != null) {
                                for (int i = 0; i < ar.Count; ++i) {
                                        PropertyBase pb = (PropertyBase) ar [i];
                                        if (pb.AreAccessorsDuplicateImplementation (this))
                                                return false;
                                }
                        }

                        ar = Parent.PartialContainer.Indexers;
                        if (ar != null) {
                                for (int i = 0; i < ar.Count; ++i) {
                                        PropertyBase pb = (PropertyBase) ar [i];
                                        if (pb.AreAccessorsDuplicateImplementation (this))
                                                return false;
                                }
                        }

                        return true;
                }

                protected override bool CheckBase ()
                {
                        if (!base.CheckBase ())
                                return false;

                        if (base_method != null && (ModFlags & Modifiers.OVERRIDE) != 0 && Name == Destructor.MetadataName) {
                                Report.Error (249, Location, "Do not override `{0}'. Use destructor syntax instead",
                                        TypeManager.CSharpSignature (base_method));
                        }

                        return true;
                }

                //
                // Creates the type
                //
                public override bool Define ()
                {
                        if (type_name == TypeManager.system_void_expr && Parameters.IsEmpty && Name == Destructor.MetadataName) {
                                Report.Warning (465, 1, Location, "Introducing `Finalize' method can interfere with destructor invocation. Did you intend to declare a destructor?");
                        }

                        if (!base.Define ())
                                return false;

                        if (RootContext.StdLib && TypeManager.IsSpecialType (ReturnType)) {
                                Error1599 (Location, ReturnType);
                                return false;
                        }

                        if (base_method != null && (ModFlags & Modifiers.NEW) == 0) {
                                if (Parameters.Count == 1 && ParameterTypes [0] == TypeManager.object_type && Name == "Equals")
                                        Parent.PartialContainer.Mark_HasEquals ();
                                else if (Parameters.IsEmpty && Name == "GetHashCode")
                                        Parent.PartialContainer.Mark_HasGetHashCode ();
                        }

                        if ((ModFlags & Modifiers.STATIC) == 0)
                                return true;

                        if (Parameters.HasExtensionMethodType) {
                                if (Parent.PartialContainer.IsStaticClass && !Parent.IsGeneric) {
                                        if (!Parent.IsTopLevel)
                                                Report.Error (1109, Location, "`{0}': Extension methods cannot be defined in a nested class",
                                                        GetSignatureForError ());

                                        PredefinedAttribute pa = PredefinedAttributes.Get.Extension;
                                        if (!pa.IsDefined) {
                                                Report.Error (1110, Location,
                                                        "`{0}': Extension methods cannot be declared without a reference to System.Core.dll assembly. Add the assembly reference or remove `this' modifer from the first parameter",
                                                        GetSignatureForError ());
                                        }

                                        ModFlags |= Modifiers.METHOD_EXTENSION;
                                        Parent.PartialContainer.ModFlags |= Modifiers.METHOD_EXTENSION;
                                        CodeGen.Assembly.HasExtensionMethods = true;
                                } else {
                                        Report.Error (1106, Location, "`{0}': Extension methods must be defined in a non-generic static class",
                                                GetSignatureForError ());
                                }
                        }

                        //
                        // This is used to track the Entry Point,
                        //
                        if (RootContext.NeedsEntryPoint &&
                                Name == "Main" &&
                                (RootContext.MainClass == null ||
                                RootContext.MainClass == Parent.TypeBuilder.FullName)){
                                if (IsEntryPoint ()) {

                                        if (RootContext.EntryPoint == null) {
                                                if (Parent.IsGeneric || MemberName.IsGeneric) {
                                                        Report.Warning (402, 4, Location, "`{0}': an entry point cannot be generic or in a generic type",
                                                                GetSignatureForError ());
                                                } else {
                                                        SetMemberIsUsed ();
                                                        RootContext.EntryPoint = this;
                                                }
                                        } else {
                                                Error_DuplicateEntryPoint (RootContext.EntryPoint);
                                                Error_DuplicateEntryPoint (this);
                                        }
                                } else {
                                        Report.Warning (28, 4, Location, "`{0}' has the wrong signature to be an entry point",
                                                GetSignatureForError ());
                                }
                        }

                        return true;
                }

                //
                // Emits the code
                // 
                public override void Emit ()
                {
                        try {
                                Report.Debug (64, "METHOD EMIT", this, MethodBuilder, Location, Block, MethodData);
                                if (IsPartialDefinition) {
                                        //
                                        // Do attribute checks only when partial implementation does not exist
                                        //
                                        if (MethodBuilder == null)
                                                base.Emit ();

                                        return;
                                }

                                if ((ModFlags & Modifiers.PARTIAL) != 0 && (caching_flags & Flags.PartialDefinitionExists) == 0)
                                        Report.Error (759, Location, "A partial method `{0}' implementation is missing a partial method declaration",
                                                GetSignatureForError ());

                                base.Emit ();
                                
                                if ((ModFlags & Modifiers.METHOD_EXTENSION) != 0)
                                        PredefinedAttributes.Get.Extension.EmitAttribute (MethodBuilder);
                        } catch {
                                Console.WriteLine ("Internal compiler error at {0}: exception caught while emitting {1}",
                                                   Location, MethodBuilder);
                                throw;
                        }
                }

                public override bool EnableOverloadChecks (MemberCore overload)
                {
                        // TODO: It can be deleted when members will be defined in correct order
                        if (overload is Operator)
                                return overload.EnableOverloadChecks (this);

                        if (overload is Indexer)
                                return false;

                        return base.EnableOverloadChecks (overload);
                }

                public static void Error1599 (Location loc, Type t)
                {
                        Report.Error (1599, loc, "Method or delegate cannot return type `{0}'", TypeManager.CSharpName (t));
                }

                protected override MethodInfo FindOutBaseMethod (ref Type base_ret_type)
                {
                        MethodInfo mi = (MethodInfo) Parent.PartialContainer.BaseCache.FindMemberToOverride (
                                Parent.TypeBuilder, Name, Parameters, GenericMethod, false);

                        if (mi == null)
                                return null;

                        if (mi.IsSpecialName)
                                return null;

                        base_ret_type = TypeManager.TypeToCoreType (mi.ReturnType);
                        return mi;
                }

                public void SetPartialDefinition (Method methodDefinition)
                {
                        caching_flags |= Flags.PartialDefinitionExists;
                        methodDefinition.MethodBuilder = MethodBuilder;

                        for (int i = 0; i < methodDefinition.Parameters.Count; ++i ) {
                                Parameters [i].DefaultValue = methodDefinition.Parameters [i].DefaultValue;
                        }

                        if (methodDefinition.attributes == null)
                                return;

                        if (attributes == null) {
                                attributes = methodDefinition.attributes;
                                attributes.AttachTo (this);
                        } else {
                                attributes.Attrs.AddRange (methodDefinition.attributes.Attrs);
                        }
                }

                protected override bool VerifyClsCompliance ()
                {
                        if (!base.VerifyClsCompliance ())
                                return false;

                        if (!Parameters.IsEmpty) {
                                ArrayList al = (ArrayList)Parent.PartialContainer.MemberCache.Members [Name];
                                if (al.Count > 1)
                                        MemberCache.VerifyClsParameterConflict (al, this, MethodBuilder);
                        }

                        return true;
                }
        }

        public abstract class ConstructorInitializer : ExpressionStatement
        {
                Arguments argument_list;
                MethodGroupExpr base_constructor_group;

                public ConstructorInitializer (Arguments argument_list, Location loc)
                {
                        this.argument_list = argument_list;
                        this.loc = loc;
                }

                public Arguments Arguments {
                        get {
                                return argument_list;
                        }
                }

                public override Expression CreateExpressionTree (EmitContext ec)
                {
                        throw new NotSupportedException ("ET");
                }

                public ExpressionStatement Resolve (ConstructorBuilder caller_builder, EmitContext ec)
                {
                        if (argument_list != null) {
                                bool dynamic;
                                argument_list.Resolve (ec, out dynamic);
                                if (dynamic) {
                                        SimpleName ctor = new SimpleName (ConstructorBuilder.ConstructorName, loc);
                                        return new DynamicInvocation (ctor, argument_list, loc).Resolve (ec) as ExpressionStatement;
                                }
                        }

                        if (this is ConstructorBaseInitializer) {
                                if (ec.ContainerType.BaseType == null)
                                        return this;

                                type = ec.ContainerType.BaseType;
                                if (TypeManager.IsStruct (ec.ContainerType)) {
                                        Report.Error (522, loc,
                                                "`{0}': Struct constructors cannot call base constructors", TypeManager.CSharpSignature (caller_builder));
                                        return this;
                                }
                        } else {
                                //
                                // It is legal to have "this" initializers that take no arguments
                                // in structs, they are just no-ops.
                                //
                                // struct D { public D (int a) : this () {}
                                //
                                if (TypeManager.IsStruct (ec.ContainerType) && argument_list == null)
                                        return this;
                                
                                type = ec.ContainerType;
                        }

                        base_constructor_group = MemberLookupFinal (
                                ec, null, type, ConstructorBuilder.ConstructorName, MemberTypes.Constructor,
                                BindingFlags.Public | BindingFlags.Instance | BindingFlags.DeclaredOnly,
                                loc) as MethodGroupExpr;
                        
                        if (base_constructor_group == null)
                                return this;
                        
                        base_constructor_group = base_constructor_group.OverloadResolve (
                                ec, ref argument_list, false, loc);
                        
                        if (base_constructor_group == null)
                                return this;
                        
                        ConstructorInfo base_ctor = (ConstructorInfo)base_constructor_group;
                        
                        if (base_ctor == caller_builder){
                                Report.Error (516, loc, "Constructor `{0}' cannot call itself", TypeManager.CSharpSignature (caller_builder));
                        }
                                                
                        return this;
                }

                public override Expression DoResolve (EmitContext ec)
                {
                        throw new NotSupportedException ();
                }

                public override void Emit (EmitContext ec)
                {
                        // It can be null for static initializers
                        if (base_constructor_group == null)
                                return;
                        
                        ec.Mark (loc);
                        if (!ec.IsStatic)
                                base_constructor_group.InstanceExpression = ec.GetThis (loc);
                        
                        base_constructor_group.EmitCall (ec, argument_list);
                }

                public override void EmitStatement (EmitContext ec)
                {
                        Emit (ec);
                }
        }

        public class ConstructorBaseInitializer : ConstructorInitializer {
                public ConstructorBaseInitializer (Arguments argument_list, Location l) :
                        base (argument_list, l)
                {
                }
        }

        class GeneratedBaseInitializer: ConstructorBaseInitializer {
                public GeneratedBaseInitializer (Location loc):
                        base (null, loc)
                {
                }
        }

        public class ConstructorThisInitializer : ConstructorInitializer {
                public ConstructorThisInitializer (Arguments argument_list, Location l) :
                        base (argument_list, l)
                {
                }
        }
        
        public class Constructor : MethodCore, IMethodData {
                public ConstructorBuilder ConstructorBuilder;
                public ConstructorInitializer Initializer;
                ListDictionary declarative_security;
                bool has_compliant_args;

                // <summary>
                //   Modifiers allowed for a constructor.
                // </summary>
                public const int AllowedModifiers =
                        Modifiers.PUBLIC |
                        Modifiers.PROTECTED |
                        Modifiers.INTERNAL |
                        Modifiers.STATIC |
                        Modifiers.UNSAFE |
                        Modifiers.EXTERN |              
                        Modifiers.PRIVATE;

                static readonly string[] attribute_targets = new string [] { "method" };

                //
                // The spec claims that static is not permitted, but
                // my very own code has static constructors.
                //
                public Constructor (DeclSpace parent, string name, int mod, Attributes attrs, ParametersCompiled args,
                                    ConstructorInitializer init, Location loc)
                        : base (parent, null, null, mod, AllowedModifiers,
                                new MemberName (name, loc), attrs, args)
                {
                        Initializer = init;
                }

                public bool HasCompliantArgs {
                        get { return has_compliant_args; }
                }

                public override AttributeTargets AttributeTargets {
                        get { return AttributeTargets.Constructor; }
                }

                //
                // Returns true if this is a default constructor
                //
                public bool IsDefault ()
                {
                        if ((ModFlags & Modifiers.STATIC) != 0)
                                return Parameters.IsEmpty;
                        
                        return Parameters.IsEmpty &&
                                        (Initializer is ConstructorBaseInitializer) &&
                                        (Initializer.Arguments == null);
                }

                public override void ApplyAttributeBuilder (Attribute a, CustomAttributeBuilder cb, PredefinedAttributes pa)
                {
                        if (a.IsValidSecurityAttribute ()) {
                                if (declarative_security == null) {
                                        declarative_security = new ListDictionary ();
                                }
                                a.ExtractSecurityPermissionSet (declarative_security);
                                return;
                        }

                        if (a.IsInternalMethodImplAttribute) {
                                is_external_implementation = true;
                        }

                        ConstructorBuilder.SetCustomAttribute (cb);
                }

                protected override bool CheckBase ()
                {
                        if ((ModFlags & Modifiers.STATIC) != 0) {
                                if (!Parameters.IsEmpty) {
                                        Report.Error (132, Location, "`{0}': The static constructor must be parameterless",
                                                GetSignatureForError ());
                                        return false;
                                }

                                // the rest can be ignored
                                return true;
                        }

                        // Check whether arguments were correct.
                        if (!DefineParameters (Parameters))
                                return false;

                        if ((caching_flags & Flags.MethodOverloadsExist) != 0)
                                Parent.MemberCache.CheckExistingMembersOverloads (this, ConstructorInfo.ConstructorName,
                                        Parameters);

                        if (Parent.PartialContainer.Kind == Kind.Struct) {
                                if (Parameters.Count == 0) {
                                        Report.Error (568, Location, 
                                                "Structs cannot contain explicit parameterless constructors");
                                        return false;
                                }
                        }

                        CheckProtectedModifier ();
                        
                        return true;
                }
                
                //
                // Creates the ConstructorBuilder
                //
                public override bool Define ()
                {
                        if (ConstructorBuilder != null)
                                return true;

                        MethodAttributes ca = (MethodAttributes.RTSpecialName |
                                               MethodAttributes.SpecialName);
                        
                        if ((ModFlags & Modifiers.STATIC) != 0) {
                                ca |= MethodAttributes.Static | MethodAttributes.Private;
                        } else {
                                ca |= MethodAttributes.HideBySig;

                                if ((ModFlags & Modifiers.PUBLIC) != 0)
                                        ca |= MethodAttributes.Public;
                                else if ((ModFlags & Modifiers.PROTECTED) != 0){
                                        if ((ModFlags & Modifiers.INTERNAL) != 0)
                                                ca |= MethodAttributes.FamORAssem;
                                        else 
                                                ca |= MethodAttributes.Family;
                                } else if ((ModFlags & Modifiers.INTERNAL) != 0)
                                        ca |= MethodAttributes.Assembly;
                                else
                                        ca |= MethodAttributes.Private;
                        }

                        if (!CheckAbstractAndExtern (block != null))
                                return false;
                        
                        // Check if arguments were correct.
                        if (!CheckBase ())
                                return false;

                        ConstructorBuilder = Parent.TypeBuilder.DefineConstructor (
                                ca, CallingConventions,
                                Parameters.GetEmitTypes ());

                        if (Parent.PartialContainer.IsComImport) {
                                if (!IsDefault ()) {
                                        Report.Error (669, Location, "`{0}': A class with the ComImport attribute cannot have a user-defined constructor",
                                                Parent.GetSignatureForError ());
                                }
                                ConstructorBuilder.SetImplementationFlags (MethodImplAttributes.InternalCall);
                        }
                        
                        Parent.MemberCache.AddMember (ConstructorBuilder, this);
                        TypeManager.AddMethod (ConstructorBuilder, this);
                        
                        // It's here only to report an error
                        if (block != null && block.IsIterator) {
                                member_type = TypeManager.void_type;
                                Iterator.CreateIterator (this, Parent.PartialContainer, ModFlags);
                        }

                        return true;
                }

                //
                // Emits the code
                //
                public override void Emit ()
                {
                        if ((ModFlags & Modifiers.DEBUGGER_HIDDEN) != 0)
                                PredefinedAttributes.Get.DebuggerHidden.EmitAttribute (ConstructorBuilder);

                        if (OptAttributes != null)
                                OptAttributes.Emit ();

                        base.Emit ();

                        EmitContext ec = CreateEmitContext (null, null);

                        //
                        // If we use a "this (...)" constructor initializer, then
                        // do not emit field initializers, they are initialized in the other constructor
                        //
                        bool emit_field_initializers = ((ModFlags & Modifiers.STATIC) != 0) ||
                                !(Initializer is ConstructorThisInitializer);

                        if (emit_field_initializers)
                                Parent.PartialContainer.ResolveFieldInitializers (ec);

                        if (block != null) {
                                // If this is a non-static `struct' constructor and doesn't have any
                                // initializer, it must initialize all of the struct's fields.
                                if ((Parent.PartialContainer.Kind == Kind.Struct) &&
                                        ((ModFlags & Modifiers.STATIC) == 0) && (Initializer == null))
                                        block.AddThisVariable (Parent, Location);

                                if (!block.ResolveMeta (ec, Parameters))
                                        block = null;

                                if (block != null && (ModFlags & Modifiers.STATIC) == 0){
                                        if (Parent.PartialContainer.Kind == Kind.Class && Initializer == null)
                                                Initializer = new GeneratedBaseInitializer (Location);

                                        //
                                        // Spec mandates that Initializers will not have `this' access
                                        //
                                        if (Initializer != null) {
                                                ec.IsStatic = true;
                                                ExpressionStatement expr = Initializer.Resolve (ConstructorBuilder, ec);
                                                ec.IsStatic = false;
                                                block.AddScopeStatement (new StatementExpression (expr));
                                        }
                                }
                        }

                        Parameters.ApplyAttributes (ConstructorBuilder);
                        
                        SourceMethod source = null;
                        if (block == null)
                                ec.OmitDebuggingInfo = true;
                        else
                                source = SourceMethod.Create (Parent, ConstructorBuilder, block);

                        bool unreachable = false;
                        if (block != null) {
                                if (!ec.ResolveTopBlock (null, block, Parameters, this, out unreachable))
                                        return;

                                ec.EmitMeta (block);

                                if (Report.Errors > 0)
                                        return;

                                ec.EmitResolvedTopBlock (block, unreachable);
                        }

                        if (source != null)
                                source.CloseMethod ();

                        if (declarative_security != null) {
                                foreach (DictionaryEntry de in declarative_security) {
                                        ConstructorBuilder.AddDeclarativeSecurity ((SecurityAction)de.Key, (PermissionSet)de.Value);
                                }
                        }

                        block = null;
                }

                // Is never override
                protected override MethodInfo FindOutBaseMethod (ref Type base_ret_type)
                {
                        return null;
                }

                public override string GetSignatureForError()
                {
                        return base.GetSignatureForError () + Parameters.GetSignatureForError ();
                }

                public override string[] ValidAttributeTargets {
                        get {
                                return attribute_targets;
                        }
                }

                protected override bool VerifyClsCompliance ()
                {
                        if (!base.VerifyClsCompliance () || !IsExposedFromAssembly ()) {
                                return false;
                        }
                        
                        if (!Parameters.IsEmpty) {
                                ArrayList al = (ArrayList)Parent.MemberCache.Members [ConstructorInfo.ConstructorName];
                                if (al.Count > 2)
                                        MemberCache.VerifyClsParameterConflict (al, this, ConstructorBuilder);
 
                                if (TypeManager.IsSubclassOf (Parent.TypeBuilder, TypeManager.attribute_type)) {
                                        foreach (Type param in Parameters.Types) {
                                                if (param.IsArray) {
                                                        return true;
                                                }
                                        }
                                }
                        }
                        has_compliant_args = true;
                        return true;
                }

                #region IMethodData Members

                public MemberName MethodName {
                        get {
                                return MemberName;
                        }
                }

                public Type ReturnType {
                        get {
                                return MemberType;
                        }
                }

                public EmitContext CreateEmitContext (DeclSpace ds, ILGenerator ig)
                {
                        ILGenerator ig_ = ConstructorBuilder.GetILGenerator ();
                        EmitContext ec = new EmitContext (this, Parent, Location, ig_, TypeManager.void_type, ModFlags, true);
                        ec.CurrentBlock = block;
                        return ec;
                }

                public bool IsExcluded()
                {
                        return false;
                }

                GenericMethod IMethodData.GenericMethod {
                        get {
                                return null;
                        }
                }

                void IMethodData.EmitExtraSymbolInfo (SourceMethod source)
                { }

                #endregion
        }

        /// <summary>
        /// Interface for MethodData class. Holds links to parent members to avoid member duplication.
        /// </summary>
        public interface IMethodData
        {
                CallingConventions CallingConventions { get; }
                Location Location { get; }
                MemberName MethodName { get; }
                Type ReturnType { get; }
                GenericMethod GenericMethod { get; }
                ParametersCompiled ParameterInfo { get; }

                Attributes OptAttributes { get; }
                ToplevelBlock Block { get; set; }

                EmitContext CreateEmitContext (DeclSpace ds, ILGenerator ig);
                ObsoleteAttribute GetObsoleteAttribute ();
                string GetSignatureForError ();
                bool IsExcluded ();
                bool IsClsComplianceRequired ();
                void SetMemberIsUsed ();
                void EmitExtraSymbolInfo (SourceMethod source);
        }

        //
        // Encapsulates most of the Method's state
        //
        public class MethodData {
                static FieldInfo methodbuilder_attrs_field;
                public readonly IMethodData method;

                public readonly GenericMethod GenericMethod;

                //
                // Are we implementing an interface ?
                //
                public MethodInfo implementing;

                //
                // Protected data.
                //
                protected InterfaceMemberBase member;
                protected int modifiers;
                protected MethodAttributes flags;
                protected Type declaring_type;
                protected MethodInfo parent_method;

                MethodBuilder builder = null;
                public MethodBuilder MethodBuilder {
                        get {
                                return builder;
                        }
                }

                public Type DeclaringType {
                        get {
                                return declaring_type;
                        }
                }

                public MethodData (InterfaceMemberBase member,
                                   int modifiers, MethodAttributes flags, IMethodData method)
                {
                        this.member = member;
                        this.modifiers = modifiers;
                        this.flags = flags;

                        this.method = method;
                }

                public MethodData (InterfaceMemberBase member, 
                                   int modifiers, MethodAttributes flags, 
                                   IMethodData method, MethodBuilder builder,
                                   GenericMethod generic, MethodInfo parent_method)
                        : this (member, modifiers, flags, method)
                {
                        this.builder = builder;
                        this.GenericMethod = generic;
                        this.parent_method = parent_method;
                }

                public bool Define (DeclSpace parent, string method_full_name)
                {
                        string name = method.MethodName.Basename;

                        TypeContainer container = parent.PartialContainer;

                        PendingImplementation pending = container.PendingImplementations;
                        if (pending != null){
                                implementing = pending.IsInterfaceMethod (name, member.InterfaceType, this);

                                if (member.InterfaceType != null){
                                        if (implementing == null){
                                                if (member is PropertyBase) {
                                                        Report.Error (550, method.Location, "`{0}' is an accessor not found in interface member `{1}{2}'",
                                                                      method.GetSignatureForError (), TypeManager.CSharpName (member.InterfaceType),
                                                                      member.GetSignatureForError ().Substring (member.GetSignatureForError ().LastIndexOf ('.')));

                                                } else {
                                                        Report.Error (539, method.Location,
                                                                      "`{0}.{1}' in explicit interface declaration is not a member of interface",
                                                                      TypeManager.CSharpName (member.InterfaceType), member.ShortName);
                                                }
                                                return false;
                                        }
                                        if (implementing.IsSpecialName && !(method is AbstractPropertyEventMethod)) {
                                                Report.SymbolRelatedToPreviousError (implementing);
                                                Report.Error (683, method.Location, "`{0}' explicit method implementation cannot implement `{1}' because it is an accessor",
                                                        member.GetSignatureForError (), TypeManager.CSharpSignature (implementing));
                                                return false;
                                        }
                                } else {
                                        if (implementing != null) {
                                                AbstractPropertyEventMethod prop_method = method as AbstractPropertyEventMethod;
                                                if (prop_method == null) {
                                                        if (TypeManager.IsSpecialMethod (implementing)) {
                                                                Report.SymbolRelatedToPreviousError (implementing);
                                                                Report.Error (470, method.Location, "Method `{0}' cannot implement interface accessor `{1}.{2}'",
                                                                        method.GetSignatureForError (), TypeManager.CSharpSignature (implementing),
                                                                        implementing.Name.StartsWith ("get_") ? "get" : "set");
                                                        }
                                                } else if (implementing.DeclaringType.IsInterface) {
                                                        if (!implementing.IsSpecialName) {
                                                                Report.SymbolRelatedToPreviousError (implementing);
                                                                Report.Error (686, method.Location, "Accessor `{0}' cannot implement interface member `{1}' for type `{2}'. Use an explicit interface implementation",
                                                                        method.GetSignatureForError (), TypeManager.CSharpSignature (implementing), container.GetSignatureForError ());
                                                                return false;
                                                        }
                                                        PropertyBase.PropertyMethod pm = prop_method as PropertyBase.PropertyMethod;
                                                        if (pm != null && pm.HasCustomAccessModifier && (pm.ModFlags & Modifiers.PUBLIC) == 0) {
                                                                Report.SymbolRelatedToPreviousError (implementing);
                                                                Report.Error (277, method.Location, "Accessor `{0}' must be declared public to implement interface member `{1}'",
                                                                        method.GetSignatureForError (), TypeManager.CSharpSignature (implementing, true));
                                                                return false;
                                                        }
                                                }
                                        }
                                }
                        }

                        //
                        // For implicit implementations, make sure we are public, for
                        // explicit implementations, make sure we are private.
                        //
                        if (implementing != null){
                                //
                                // Setting null inside this block will trigger a more
                                // verbose error reporting for missing interface implementations
                                //
                                // The "candidate" function has been flagged already
                                // but it wont get cleared
                                //
                                if (member.IsExplicitImpl){
                                        if (method.ParameterInfo.HasParams && !TypeManager.GetParameterData (implementing).HasParams) {
                                                Report.SymbolRelatedToPreviousError (implementing);
                                                Report.Error (466, method.Location, "`{0}': the explicit interface implementation cannot introduce the params modifier",
                                                        method.GetSignatureForError ());
                                                return false;
                                        }
                                } else {
                                        if (implementing.DeclaringType.IsInterface) {
                                                //
                                                // If this is an interface method implementation,
                                                // check for public accessibility
                                                //
                                                if ((flags & MethodAttributes.MemberAccessMask) != MethodAttributes.Public)
                                                {
                                                        implementing = null;
                                                }
                                        } else if ((flags & MethodAttributes.MemberAccessMask) == MethodAttributes.Private){
                                                // We may never be private.
                                                implementing = null;

                                        } else if ((modifiers & Modifiers.OVERRIDE) == 0){
                                                //
                                                // We may be protected if we're overriding something.
                                                //
                                                implementing = null;
                                        }
                                }
                                        
                                //
                                // Static is not allowed
                                //
                                if ((modifiers & Modifiers.STATIC) != 0){
                                        implementing = null;
                                }
                        }
                        
                        //
                        // If implementing is still valid, set flags
                        //
                        if (implementing != null){
                                //
                                // When implementing interface methods, set NewSlot
                                // unless, we are overwriting a method.
                                //
                                if (implementing.DeclaringType.IsInterface){
                                        if ((modifiers & Modifiers.OVERRIDE) == 0)
                                                flags |= MethodAttributes.NewSlot;
                                }
                                flags |=
                                        MethodAttributes.Virtual |
                                        MethodAttributes.HideBySig;

                                // Set Final unless we're virtual, abstract or already overriding a method.
                                if ((modifiers & (Modifiers.VIRTUAL | Modifiers.ABSTRACT | Modifiers.OVERRIDE)) == 0)
                                        flags |= MethodAttributes.Final;
                        }

                        DefineMethodBuilder (container, method_full_name, method.ParameterInfo);

                        if (builder == null)
                                return false;

                        if (container.CurrentType != null)
                                declaring_type = container.CurrentType;
                        else
                                declaring_type = container.TypeBuilder;

                        if (implementing != null && member.IsExplicitImpl) {
                                        container.TypeBuilder.DefineMethodOverride (builder, implementing);
                        }

                        TypeManager.AddMethod (builder, method);

                        if (GenericMethod != null) {
                                bool is_override = member.IsExplicitImpl |
                                        ((modifiers & Modifiers.OVERRIDE) != 0);

                                if (implementing != null)
                                        parent_method = implementing;

                                EmitContext ec = method.CreateEmitContext (container, null);
                                if (!GenericMethod.DefineType (ec, builder, parent_method, is_override))
                                        return false;
                        }

                        return true;
                }


                /// <summary>
                /// Create the MethodBuilder for the method 
                /// </summary>
                void DefineMethodBuilder (TypeContainer container, string method_name, ParametersCompiled param)
                {
                        if (builder == null) {
                                builder = container.TypeBuilder.DefineMethod (
                                        method_name, flags, method.CallingConventions,
                                        TypeManager.TypeToReflectionType (method.ReturnType),
                                        param.GetEmitTypes ());
                                return;
                        }

#if GMCS_SOURCE
                        //
                        // Generic method has been already defined to resolve method parameters
                        // correctly when they use type parameters
                        //
                        builder.SetParameters (param.GetEmitTypes ());
                        builder.SetReturnType (method.ReturnType);
#endif
                        if (builder.Attributes != flags) {
                                try {
                                        if (methodbuilder_attrs_field == null)
                                                methodbuilder_attrs_field = typeof (MethodBuilder).GetField ("attrs", BindingFlags.NonPublic | BindingFlags.Instance);
                                        methodbuilder_attrs_field.SetValue (builder, flags);
                                } catch {
                                        Report.RuntimeMissingSupport (method.Location, "Generic method MethodAttributes");
                                }
                        }
                }

                //
                // Emits the code
                // 
                public void Emit (DeclSpace parent)
                {
                        ToplevelBlock block = method.Block;

                        EmitContext ec;
                        if (block != null)
                                ec = method.CreateEmitContext (parent, builder.GetILGenerator ());
                        else
                                ec = method.CreateEmitContext (parent, null);

                        method.ParameterInfo.ApplyAttributes (MethodBuilder);

                        if (GenericMethod != null)
                                GenericMethod.EmitAttributes ();

                        //
                        // clear the pending implementation flag
                        //
                        if (implementing != null)
                                parent.PartialContainer.PendingImplementations.ImplementMethod (method.MethodName.Basename,
                                        member.InterfaceType, this, member.IsExplicitImpl);

                        SourceMethod source = SourceMethod.Create (parent, MethodBuilder, method.Block);

                        ec.EmitTopBlock (method, block);

                        if (source != null) {
                                method.EmitExtraSymbolInfo (source);
                                source.CloseMethod ();
                        }
                }
        }

        public class Destructor : MethodOrOperator
        {
                const int AllowedModifiers =
                        Modifiers.UNSAFE |
                        Modifiers.EXTERN;

                static readonly string[] attribute_targets = new string [] { "method" };

                public static readonly string MetadataName = "Finalize";

                public Destructor (DeclSpace parent, int mod, ParametersCompiled parameters, Attributes attrs, Location l)
                        : base (parent, null, TypeManager.system_void_expr, mod, AllowedModifiers,
                                new MemberName (MetadataName, l), attrs, parameters)
                {
                        ModFlags &= ~Modifiers.PRIVATE;
                        ModFlags |= Modifiers.PROTECTED;
                }

                public override void ApplyAttributeBuilder (Attribute a, CustomAttributeBuilder cb, PredefinedAttributes pa)
                {
                        if (a.Type == pa.Conditional) {
                                Error_ConditionalAttributeIsNotValid ();
                                return;
                        }

                        base.ApplyAttributeBuilder (a, cb, pa);
                }

                protected override bool CheckBase ()
                {
                        flags |= MethodAttributes.Virtual;

                        if (!base.CheckBase ())
                                return false;

                        if (Parent.PartialContainer.BaseCache == null)
                                return true;

                        Type base_type = Parent.PartialContainer.BaseCache.Container.Type;
                        if (base_type != null && Block != null) {
                                MethodGroupExpr method_expr = Expression.MethodLookup (Parent.TypeBuilder, base_type, MetadataName, Location);
                                if (method_expr == null)
                                        throw new NotImplementedException ();

                                method_expr.IsBase = true;
                                method_expr.InstanceExpression = new CompilerGeneratedThis (Parent.TypeBuilder, Location);

                                ToplevelBlock new_block = new ToplevelBlock (Block.StartLocation);
                                new_block.EndLocation = Block.EndLocation;

                                Block finaly_block = new ExplicitBlock (new_block, Location, Location);
                                Block try_block = new Block (new_block, block);

                                //
                                // 0-size arguments to avoid CS0250 error
                                // TODO: Should use AddScopeStatement or something else which emits correct
                                // debugger scope
                                //
                                finaly_block.AddStatement (new StatementExpression (new Invocation (method_expr, new Arguments (0))));
                                new_block.AddStatement (new TryFinally (try_block, finaly_block, Location));

                                block = new_block;
                        }

                        return true;
                }

                public override string GetSignatureForError ()
                {
                        return Parent.GetSignatureForError () + ".~" + Parent.MemberName.Name + "()";
                }

                protected override MethodInfo FindOutBaseMethod (ref Type base_ret_type)
                {
                        return null;
                }

                public override string[] ValidAttributeTargets {
                        get {
                                return attribute_targets;
                        }
                }
        }
        
        public abstract class MemberBase : MemberCore
        {
                protected FullNamedExpression type_name;
                protected Type member_type;

                public readonly DeclSpace ds;
                public readonly GenericMethod GenericMethod;

                protected MemberBase (DeclSpace parent, GenericMethod generic,
                                      FullNamedExpression type, int mod, int allowed_mod, int def_mod,
                                      MemberName name, Attributes attrs)
                        : base (parent, name, attrs)
                {
                        this.ds = generic != null ? generic : (DeclSpace) parent;
                        this.type_name = type;
                        ModFlags = Modifiers.Check (allowed_mod, mod, def_mod, Location);
                        GenericMethod = generic;
                        if (GenericMethod != null)
                                GenericMethod.ModFlags = ModFlags;
                }

                //
                // Main member define entry
                //
                public override bool Define ()
                {
                        DoMemberTypeIndependentChecks ();

                        //
                        // Returns false only when type resolution failed
                        //
                        if (!ResolveMemberType ())
                                return false;

                        DoMemberTypeDependentChecks ();
                        return true;
                }

                //
                // Any type_name independent checks
                //
                protected virtual void DoMemberTypeIndependentChecks ()
                {
                        if ((Parent.ModFlags & Modifiers.SEALED) != 0 &&
                                (ModFlags & (Modifiers.VIRTUAL | Modifiers.ABSTRACT)) != 0) {
                                Report.Error (549, Location, "New virtual member `{0}' is declared in a sealed class `{1}'",
                                        GetSignatureForError (), Parent.GetSignatureForError ());
                        }
                }

                //
                // Any type_name dependent checks
                //
                protected virtual void DoMemberTypeDependentChecks ()
                {
                        // verify accessibility
                        if (!IsAccessibleAs (MemberType)) {
                                Report.SymbolRelatedToPreviousError (MemberType);
                                if (this is Property)
                                        Report.Error (53, Location,
                                                      "Inconsistent accessibility: property type `" +
                                                      TypeManager.CSharpName (MemberType) + "' is less " +
                                                      "accessible than property `" + GetSignatureForError () + "'");
                                else if (this is Indexer)
                                        Report.Error (54, Location,
                                                      "Inconsistent accessibility: indexer return type `" +
                                                      TypeManager.CSharpName (MemberType) + "' is less " +
                                                      "accessible than indexer `" + GetSignatureForError () + "'");
                                else if (this is MethodCore) {
                                        if (this is Operator)
                                                Report.Error (56, Location,
                                                              "Inconsistent accessibility: return type `" +
                                                              TypeManager.CSharpName (MemberType) + "' is less " +
                                                              "accessible than operator `" + GetSignatureForError () + "'");
                                        else
                                                Report.Error (50, Location,
                                                              "Inconsistent accessibility: return type `" +
                                                              TypeManager.CSharpName (MemberType) + "' is less " +
                                                              "accessible than method `" + GetSignatureForError () + "'");
                                } else {
                                        Report.Error (52, Location,
                                                      "Inconsistent accessibility: field type `" +
                                                      TypeManager.CSharpName (MemberType) + "' is less " +
                                                      "accessible than field `" + GetSignatureForError () + "'");
                                }
                        }

                        Variance variance = this is Event ? Variance.Contravariant : Variance.Covariant;
                        TypeManager.CheckTypeVariance (MemberType, variance, this);
                }

                protected bool IsTypePermitted ()
                {
                        if (TypeManager.IsSpecialType (MemberType)) {
                                Report.Error (610, Location, "Field or property cannot be of type `{0}'", TypeManager.CSharpName (MemberType));
                                return false;
                        }
                        return true;
                }

                protected virtual bool CheckBase ()
                {
                        CheckProtectedModifier ();

                        return true;
                }

                public Type MemberType {
                        get { return member_type; }
                }

                protected virtual bool ResolveMemberType ()
                {
                        if (member_type != null)
                                throw new InternalErrorException ("Multi-resolve");

                        IResolveContext rc = GenericMethod == null ? this : (IResolveContext) ds;
                        TypeExpr te = type_name.ResolveAsTypeTerminal (rc, false);
                        if (te == null)
                                return false;
                        
                        //
                        // Replace original type name, error reporting can use fully resolved name
                        //
                        type_name = te;

                        member_type = te.Type;
                        return true;
                }
        }

        //
        // Abstract class for all fields
        //
        abstract public class FieldBase : MemberBase {
                public FieldBuilder FieldBuilder;
                public Status status;
                protected Expression initializer;

                [Flags]
                public enum Status : byte {
                        HAS_OFFSET = 4          // Used by FieldMember.
                }

                static readonly string[] attribute_targets = new string [] { "field" };

                protected FieldBase (DeclSpace parent, FullNamedExpression type, int mod,
                                     int allowed_mod, MemberName name, Attributes attrs)
                        : base (parent, null, type, mod, allowed_mod | Modifiers.ABSTRACT, Modifiers.PRIVATE,
                                name, attrs)
                {
                        if ((mod & Modifiers.ABSTRACT) != 0)
                                Report.Error (681, Location, "The modifier 'abstract' is not valid on fields. Try using a property instead");
                }

                public override AttributeTargets AttributeTargets {
                        get {
                                return AttributeTargets.Field;
                        }
                }

                public override void ApplyAttributeBuilder (Attribute a, CustomAttributeBuilder cb, PredefinedAttributes pa)
                {
                        if (a.Type == pa.FieldOffset) {
                                status |= Status.HAS_OFFSET;

                                if (!Parent.PartialContainer.HasExplicitLayout) {
                                        Report.Error (636, Location, "The FieldOffset attribute can only be placed on members of types marked with the StructLayout(LayoutKind.Explicit)");
                                        return;
                                }

                                if ((ModFlags & Modifiers.STATIC) != 0 || this is Const) {
                                        Report.Error (637, Location, "The FieldOffset attribute is not allowed on static or const fields");
                                        return;
                                }
                        }

#if NET_2_0
                        if (a.Type == pa.FixedBuffer) {
                                Report.Error (1716, Location, "Do not use 'System.Runtime.CompilerServices.FixedBuffer' attribute. Use the 'fixed' field modifier instead");
                                return;
                        }
#endif

#if !NET_2_0
                        if (a.Type == pa.MarshalAs) {
                                UnmanagedMarshal marshal = a.GetMarshal (this);
                                if (marshal != null) {
                                        FieldBuilder.SetMarshal (marshal);
                                }
                                return;
                        }
#endif
                        if ((a.HasSecurityAttribute)) {
                                a.Error_InvalidSecurityParent ();
                                return;
                        }

                        FieldBuilder.SetCustomAttribute (cb);
                }

                protected override bool CheckBase ()
                {
                        if (!base.CheckBase ())
                                return false;
 
                        MemberInfo conflict_symbol = Parent.PartialContainer.FindBaseMemberWithSameName (Name, false);
                        if (conflict_symbol == null) {
                                if ((ModFlags & Modifiers.NEW) != 0) {
                                        Report.Warning (109, 4, Location, "The member `{0}' does not hide an inherited member. The new keyword is not required", GetSignatureForError ());
                                }
                                return true;
                        }
 
                        if ((ModFlags & (Modifiers.NEW | Modifiers.OVERRIDE | Modifiers.BACKING_FIELD)) == 0) {
                                Report.SymbolRelatedToPreviousError (conflict_symbol);
                                Report.Warning (108, 2, Location, "`{0}' hides inherited member `{1}'. Use the new keyword if hiding was intended",
                                        GetSignatureForError (), TypeManager.GetFullNameSignature (conflict_symbol));
                        }
 
                        return true;
                }

                protected override void DoMemberTypeDependentChecks ()
                {
                        base.DoMemberTypeDependentChecks ();

                        if (TypeManager.IsGenericParameter (MemberType))
                                return;

                        if (MemberType.IsSealed && MemberType.IsAbstract) {
                                Error_VariableOfStaticClass (Location, GetSignatureForError (), MemberType);
                        }

                        CheckBase ();
                        IsTypePermitted ();
                }

                //
                //   Represents header string for documentation comment.
                //
                public override string DocCommentHeader {
                        get { return "F:"; }
                }

                public override void Emit ()
                {
                        if (TypeManager.IsDynamicType (member_type))
                                PredefinedAttributes.Get.Dynamic.EmitAttribute (FieldBuilder);

                        if ((ModFlags & Modifiers.COMPILER_GENERATED) != 0 && !Parent.IsCompilerGenerated)
                                PredefinedAttributes.Get.CompilerGenerated.EmitAttribute (FieldBuilder);

                        if (OptAttributes != null) {
                                OptAttributes.Emit ();
                        }

                        if (((status & Status.HAS_OFFSET) == 0) && (ModFlags & (Modifiers.STATIC | Modifiers.BACKING_FIELD)) == 0 && Parent.PartialContainer.HasExplicitLayout) {
                                Report.Error (625, Location, "`{0}': Instance field types marked with StructLayout(LayoutKind.Explicit) must have a FieldOffset attribute", GetSignatureForError ());
                        }

                        base.Emit ();
                }

                public static void Error_VariableOfStaticClass (Location loc, string variable_name, Type static_class)
                {
                        Report.SymbolRelatedToPreviousError (static_class);
                        Report.Error (723, loc, "`{0}': cannot declare variables of static types",
                                variable_name);
                }

                public Expression Initializer {
                        set {
                                if (value != null) {
                                        this.initializer = value;
                                }
                        }
                }

                protected virtual bool IsFieldClsCompliant {
                        get {
                                if (FieldBuilder == null)
                                        return true;

                                return AttributeTester.IsClsCompliant (FieldBuilder.FieldType);
                        }
                }

                public override string[] ValidAttributeTargets 
                {
                        get {
                                return attribute_targets;
                        }
                }

                protected override bool VerifyClsCompliance ()
                {
                        if (!base.VerifyClsCompliance ())
                                return false;

                        if (!IsFieldClsCompliant) {
                                Report.Warning (3003, 1, Location, "Type of `{0}' is not CLS-compliant",
                                        GetSignatureForError ());
                        }
                        return true;
                }

                public void SetAssigned ()
                {
                        caching_flags |= Flags.IsAssigned;
                }
        }

        interface IFixedBuffer
        {
                FieldInfo Element { get; }
                Type ElementType { get; }
        }

        public class FixedFieldExternal: IFixedBuffer
        {
                FieldInfo element_field;

                public FixedFieldExternal (FieldInfo fi)
                {
                        element_field = fi.FieldType.GetField (FixedField.FixedElementName);
                }

                #region IFixedField Members

                public FieldInfo Element {
                        get {
                                return element_field;
                        }
                }

                public Type ElementType {
                        get {
                                return element_field.FieldType;
                        }
                }

                #endregion
        }

        /// <summary>
        /// Fixed buffer implementation
        /// </summary>
        public class FixedField : FieldBase, IFixedBuffer
        {
                public const string FixedElementName = "FixedElementField";
                static int GlobalCounter = 0;
                static object[] ctor_args = new object[] { (short)LayoutKind.Sequential };
                static FieldInfo[] fi;

                TypeBuilder fixed_buffer_type;
                FieldBuilder element;
                Expression size_expr;

                const int AllowedModifiers =
                        Modifiers.NEW |
                        Modifiers.PUBLIC |
                        Modifiers.PROTECTED |
                        Modifiers.INTERNAL |
                        Modifiers.PRIVATE;

                public FixedField (DeclSpace parent, FullNamedExpression type, int mod, string name,
                        Expression size_expr, Attributes attrs, Location loc):
                        base (parent, type, mod, AllowedModifiers, new MemberName (name, loc), attrs)
                {
                        if (RootContext.Version < LanguageVersion.ISO_2)
                                Report.FeatureIsNotAvailable (loc, "fixed size buffers");

                        this.size_expr = size_expr;
                }

                public override bool Define()
                {
                        if (!base.Define ())
                                return false;

                        if (!TypeManager.IsPrimitiveType (MemberType)) {
                                Report.Error (1663, Location, "`{0}': Fixed size buffers type must be one of the following: bool, byte, short, int, long, char, sbyte, ushort, uint, ulong, float or double",
                                        GetSignatureForError ());
                        }                       
                        
                        // Create nested fixed buffer container
                        string name = String.Format ("<{0}>__FixedBuffer{1}", Name, GlobalCounter++);
                        fixed_buffer_type = Parent.TypeBuilder.DefineNestedType (name, Parent.Module.DefaultCharSetType |
                                TypeAttributes.NestedPublic | TypeAttributes.Sealed | TypeAttributes.BeforeFieldInit, TypeManager.value_type);
                        
                        element = fixed_buffer_type.DefineField (FixedElementName, MemberType, FieldAttributes.Public);
                        RootContext.RegisterCompilerGeneratedType (fixed_buffer_type);
                        
                        FieldBuilder = Parent.TypeBuilder.DefineField (Name, fixed_buffer_type, Modifiers.FieldAttr (ModFlags));
                        Parent.MemberCache.AddMember (FieldBuilder, this);
                        TypeManager.RegisterFieldBase (FieldBuilder, this);

                        return true;
                }

                protected override void DoMemberTypeIndependentChecks ()
                {
                        base.DoMemberTypeIndependentChecks ();

                        if (!Parent.IsInUnsafeScope)
                                Expression.UnsafeError (Location);

                        if (Parent.PartialContainer.Kind != Kind.Struct) {
                                Report.Error (1642, Location, "`{0}': Fixed size buffer fields may only be members of structs",
                                        GetSignatureForError ());
                        }
                }

                public override void Emit()
                {
                        EmitContext ec = new EmitContext (this, Parent, Location, null, TypeManager.void_type, ModFlags);
                        Constant c = size_expr.ResolveAsConstant (ec, this);
                        if (c == null)
                                return;
                        
                        IntConstant buffer_size_const = c.ImplicitConversionRequired (ec, TypeManager.int32_type, Location) as IntConstant;
                        if (buffer_size_const == null)
                                return;

                        int buffer_size = buffer_size_const.Value;

                        if (buffer_size <= 0) {
                                Report.Error (1665, Location, "`{0}': Fixed size buffers must have a length greater than zero", GetSignatureForError ());
                                return;
                        }

                        int type_size = Expression.GetTypeSize (MemberType);

                        if (buffer_size > int.MaxValue / type_size) {
                                Report.Error (1664, Location, "Fixed size buffer `{0}' of length `{1}' and type `{2}' exceeded 2^31 limit",
                                        GetSignatureForError (), buffer_size.ToString (), TypeManager.CSharpName (MemberType));
                                return;
                        }

                        buffer_size *= type_size;
                        EmitFieldSize (buffer_size);

                        PredefinedAttributes.Get.UnsafeValueType.EmitAttribute (fixed_buffer_type);

                        base.Emit ();
                }

                void EmitFieldSize (int buffer_size)
                {
                        CustomAttributeBuilder cab;
                        PredefinedAttribute pa;

                        pa = PredefinedAttributes.Get.StructLayout;
                        if (pa.Constructor == null &&
                                !pa.ResolveConstructor (Location, TypeManager.short_type))
                                        return;

                        // TODO: It's not cleared
                        if (fi == null)
                                fi = new FieldInfo[] { pa.Type.GetField ("Size") };

                        object[] fi_val = new object[] { buffer_size };
                        cab = new CustomAttributeBuilder (pa.Constructor,
                                ctor_args, fi, fi_val);
                        fixed_buffer_type.SetCustomAttribute (cab);
                        
                        //
                        // Don't emit FixedBufferAttribute attribute for private types
                        //
                        if ((ModFlags & Modifiers.PRIVATE) != 0)
                                return;

                        pa = PredefinedAttributes.Get.FixedBuffer;
                        if (pa.Constructor == null &&
                                !pa.ResolveConstructor (Location, TypeManager.type_type, TypeManager.int32_type))
                                return;

                        cab = new CustomAttributeBuilder (pa.Constructor, new object[] { MemberType, buffer_size });
                        FieldBuilder.SetCustomAttribute (cab);
                }

                protected override bool IsFieldClsCompliant {
                        get {
                                return false;
                        }
                }

                public void SetCharSet (TypeAttributes ta)
                {
                        TypeAttributes cta = fixed_buffer_type.Attributes;
                        if ((cta & TypeAttributes.UnicodeClass) != (ta & TypeAttributes.UnicodeClass))
                                SetTypeBuilderCharSet ((cta & ~TypeAttributes.AutoClass) | TypeAttributes.UnicodeClass);
                        else if ((cta & TypeAttributes.AutoClass) != (ta & TypeAttributes.AutoClass))
                                SetTypeBuilderCharSet ((cta & ~TypeAttributes.UnicodeClass) | TypeAttributes.AutoClass);
                        else if (cta == 0 && ta != 0)
                                SetTypeBuilderCharSet (cta & ~(TypeAttributes.UnicodeClass | TypeAttributes.AutoClass));
                }

                void SetTypeBuilderCharSet (TypeAttributes ta)
                {
                        MethodInfo mi = typeof (TypeBuilder).GetMethod ("SetCharSet", BindingFlags.Instance | BindingFlags.NonPublic);
                        if (mi == null) {
                                Report.RuntimeMissingSupport (Location, "TypeBuilder::SetCharSet");
                        } else {
                                mi.Invoke (fixed_buffer_type, new object [] { ta });
                        }
                }

                #region IFixedField Members

                public FieldInfo Element {
                        get {
                                return element;
                        }
                }

                public Type ElementType {
                        get {
                                return MemberType;
                        }
                }

                #endregion
        }

        //
        // The Field class is used to represents class/struct fields during parsing.
        //
        public class Field : FieldBase {
                // <summary>
                //   Modifiers allowed in a class declaration
                // </summary>
                const int AllowedModifiers =
                        Modifiers.NEW |
                        Modifiers.PUBLIC |
                        Modifiers.PROTECTED |
                        Modifiers.INTERNAL |
                        Modifiers.PRIVATE |
                        Modifiers.STATIC |
                        Modifiers.VOLATILE |
                        Modifiers.UNSAFE |
                        Modifiers.READONLY;

                public Field (DeclSpace parent, FullNamedExpression type, int mod, MemberName name,
                              Attributes attrs)
                        : base (parent, type, mod, AllowedModifiers, name, attrs)
                {
                }

                bool CanBeVolatile ()
                {
                        if (TypeManager.IsReferenceType (MemberType))
                                return true;

                        if (MemberType == TypeManager.bool_type || MemberType == TypeManager.char_type ||
                                MemberType == TypeManager.sbyte_type || MemberType == TypeManager.byte_type ||
                                MemberType == TypeManager.short_type || MemberType == TypeManager.ushort_type ||
                                MemberType == TypeManager.int32_type || MemberType == TypeManager.uint32_type ||
                                MemberType == TypeManager.float_type ||
                                MemberType == TypeManager.intptr_type || MemberType == TypeManager.uintptr_type)
                                return true;

                        if (TypeManager.IsEnumType (MemberType))
                                return true;

                        return false;
                }

                bool CheckStructLayout (Type type, bool isStatic)
                {
                        if (TypeManager.IsBuiltinType (type))
                                return true;

                        if (isStatic) {
                                if (!TypeManager.IsValueType (type) || TypeManager.IsEqual (type, Parent.TypeBuilder))
                                        return true;
                        }

                        if (!TypeManager.IsEqual (TypeManager.DropGenericTypeArguments (type), Parent.TypeBuilder)) {
                                if (!TypeManager.IsGenericType (type))
                                        return true;

                                foreach (Type t in TypeManager.GetTypeArguments (type)) {
                                        if (!CheckStructLayout (t, false))
                                                return false;
                                }
                                return true;
                        }
                        
                        Report.Error (523, Location,
                                "Struct member `{0}' of type `{1}' causes a cycle in the struct layout",
                                GetSignatureForError (), TypeManager.CSharpName (MemberType));
                        return false;
                }

                public override bool Define ()
                {
                        if (!base.Define ())
                                return false;

                        try {
#if GMCS_SOURCE
                                Type[] required_modifier = null;
                                if ((ModFlags & Modifiers.VOLATILE) != 0) {
                                        if (TypeManager.isvolatile_type == null)
                                                TypeManager.isvolatile_type = TypeManager.CoreLookupType (
                                                        "System.Runtime.CompilerServices", "IsVolatile", Kind.Class, true);

                                        if (TypeManager.isvolatile_type != null)
                                                required_modifier = new Type [] { TypeManager.isvolatile_type };
                                }

                                FieldBuilder = Parent.TypeBuilder.DefineField (
                                        Name, MemberType, required_modifier, null, Modifiers.FieldAttr (ModFlags));
#else
                                FieldBuilder = Parent.TypeBuilder.DefineField (
                                        Name, MemberType, Modifiers.FieldAttr (ModFlags));
#endif
                                // Don't cache inaccessible fields
                                if ((ModFlags & Modifiers.BACKING_FIELD) == 0) {
                                        Parent.MemberCache.AddMember (FieldBuilder, this);
                                }

                                TypeManager.RegisterFieldBase (FieldBuilder, this);
                        }
                        catch (ArgumentException) {
                                Report.RuntimeMissingSupport (Location, "`void' or `void*' field type");
                                return false;
                        }

                        if (initializer != null) {
                                ((TypeContainer) Parent).RegisterFieldForInitialization (this,
                                        new FieldInitializer (FieldBuilder, initializer, this));
                        } else {
                                if (Parent.PartialContainer.Kind == Kind.Struct)
                                        CheckStructLayout (member_type, (ModFlags & Modifiers.STATIC) != 0);
                        }

                        return true;
                }

                protected override void DoMemberTypeDependentChecks ()
                {
                        base.DoMemberTypeDependentChecks ();

                        if ((ModFlags & Modifiers.VOLATILE) != 0) {
                                if (!CanBeVolatile ()) {
                                        Report.Error (677, Location, "`{0}': A volatile field cannot be of the type `{1}'",
                                                GetSignatureForError (), TypeManager.CSharpName (MemberType));
                                }

                                if ((ModFlags & Modifiers.READONLY) != 0) {
                                        Report.Error (678, Location, "`{0}': A field cannot be both volatile and readonly",
                                                GetSignatureForError ());
                                }
                        }
                }

                protected override bool VerifyClsCompliance ()
                {
                        if (!base.VerifyClsCompliance ())
                                return false;

                        if ((ModFlags & Modifiers.VOLATILE) != 0) {
                                Report.Warning (3026, 1, Location, "CLS-compliant field `{0}' cannot be volatile", GetSignatureForError ());
                        }

                        return true;
                }
        }

        //
        // `set' and `get' accessors are represented with an Accessor.
        // 
        public class Accessor {
                //
                // Null if the accessor is empty, or a Block if not
                //
                public const int AllowedModifiers = 
                        Modifiers.PUBLIC |
                        Modifiers.PROTECTED |
                        Modifiers.INTERNAL |
                        Modifiers.PRIVATE;
                
                public ToplevelBlock Block;
                public Attributes Attributes;
                public Location Location;
                public int ModFlags;
                public ParametersCompiled Parameters;
                
                public Accessor (ToplevelBlock b, int mod, Attributes attrs, ParametersCompiled p, Location loc)
                {
                        Block = b;
                        Attributes = attrs;
                        Location = loc;
                        Parameters = p;
                        ModFlags = Modifiers.Check (AllowedModifiers, mod, 0, loc);
                }
        }

        // Ooouh Martin, templates are missing here.
        // When it will be possible move here a lot of child code and template method type.
        public abstract class AbstractPropertyEventMethod : MemberCore, IMethodData {
                protected MethodData method_data;
                protected ToplevelBlock block;
                protected ListDictionary declarative_security;

                // The accessor are created even if they are not wanted.
                // But we need them because their names are reserved.
                // Field says whether accessor will be emited or not
                public readonly bool IsDummy;

                protected readonly string prefix;

                ReturnParameter return_attributes;

                public AbstractPropertyEventMethod (PropertyBasedMember member, string prefix)
                        : base (member.Parent, SetupName (prefix, member, member.Location), null)
                {
                        this.prefix = prefix;
                        IsDummy = true;
                }

                public AbstractPropertyEventMethod (InterfaceMemberBase member, Accessor accessor,
                                                    string prefix)
                        : base (member.Parent, SetupName (prefix, member, accessor.Location),
                                accessor.Attributes)
                {
                        this.prefix = prefix;
                        this.block = accessor.Block;
                }

                static MemberName SetupName (string prefix, InterfaceMemberBase member, Location loc)
                {
                        return new MemberName (member.MemberName.Left, prefix + member.ShortName, loc);
                }

                public void UpdateName (InterfaceMemberBase member)
                {
                        SetMemberName (SetupName (prefix, member, Location));
                }

                #region IMethodData Members

                public ToplevelBlock Block {
                        get {
                                return block;
                        }

                        set {
                                block = value;
                        }
                }

                public CallingConventions CallingConventions {
                        get {
                                return CallingConventions.Standard;
                        }
                }

                public bool IsExcluded ()
                {
                        return false;
                }

                GenericMethod IMethodData.GenericMethod {
                        get {
                                return null;
                        }
                }

                public MemberName MethodName {
                        get {
                                return MemberName;
                        }
                }

                public Type[] ParameterTypes { 
                        get {
                                return ParameterInfo.Types;
                        }
                }

                public abstract ParametersCompiled ParameterInfo { get ; }
                public abstract Type ReturnType { get; }
                public abstract EmitContext CreateEmitContext (DeclSpace ds, ILGenerator ig);

                #endregion

                public override void ApplyAttributeBuilder (Attribute a, CustomAttributeBuilder cb, PredefinedAttributes pa)
                {
                        if (a.Type == pa.CLSCompliant || a.Type == pa.Obsolete || a.Type == pa.Conditional) {
                                Report.Error (1667, a.Location,
                                        "Attribute `{0}' is not valid on property or event accessors. It is valid on `{1}' declarations only",
                                        TypeManager.CSharpName (a.Type), a.GetValidTargets ());
                                return;
                        }

                        if (a.IsValidSecurityAttribute ()) {
                                if (declarative_security == null)
                                        declarative_security = new ListDictionary ();
                                a.ExtractSecurityPermissionSet (declarative_security);
                                return;
                        }

                        if (a.Target == AttributeTargets.Method) {
                                method_data.MethodBuilder.SetCustomAttribute (cb);
                                return;
                        }

                        if (a.Target == AttributeTargets.ReturnValue) {
                                if (return_attributes == null)
                                        return_attributes = new ReturnParameter (method_data.MethodBuilder, Location);

                                return_attributes.ApplyAttributeBuilder (a, cb, pa);
                                return;
                        }

                        ApplyToExtraTarget (a, cb, pa);
                }

                protected virtual void ApplyToExtraTarget (Attribute a, CustomAttributeBuilder cb, PredefinedAttributes pa)
                {
                        throw new NotSupportedException ("You forgot to define special attribute target handling");
                }

                // It is not supported for the accessors
                public sealed override bool Define()
                {
                        throw new NotSupportedException ();
                }

                public virtual void Emit (DeclSpace parent)
                {
                        method_data.Emit (parent);

                        if ((ModFlags & Modifiers.COMPILER_GENERATED) != 0 && !Parent.IsCompilerGenerated)
                                PredefinedAttributes.Get.CompilerGenerated.EmitAttribute (method_data.MethodBuilder);
                        if (((ModFlags & Modifiers.DEBUGGER_HIDDEN) != 0))
                                PredefinedAttributes.Get.DebuggerHidden.EmitAttribute (method_data.MethodBuilder);

                        if (TypeManager.IsDynamicType (ReturnType)) {
                                return_attributes = new ReturnParameter (method_data.MethodBuilder, Location);
                                return_attributes.EmitPredefined (PredefinedAttributes.Get.Dynamic, Location);
                        }

                        if (OptAttributes != null)
                                OptAttributes.Emit ();

                        if (declarative_security != null) {
                                foreach (DictionaryEntry de in declarative_security) {
                                        method_data.MethodBuilder.AddDeclarativeSecurity ((SecurityAction)de.Key, (PermissionSet)de.Value);
                                }
                        }

                        block = null;
                }

                public override bool EnableOverloadChecks (MemberCore overload)
                {
                        // This can only happen with indexers and it will
                        // be catched as indexer difference
                        if (overload is AbstractPropertyEventMethod)
                                return true;

                        if (overload is MethodCore) {
                                caching_flags |= Flags.MethodOverloadsExist;
                                return true;
                        }
                        return false;
                }

                public override bool IsClsComplianceRequired()
                {
                        return false;
                }

                public bool IsDuplicateImplementation (MethodCore method)
                {
                        if (!MemberName.Equals (method.MemberName))
                                return false;

                        Type[] param_types = method.ParameterTypes;

                        if (param_types == null || param_types.Length != ParameterTypes.Length)
                                return false;

                        for (int i = 0; i < param_types.Length; i++)
                                if (param_types [i] != ParameterTypes [i])
                                        return false;

                        Report.SymbolRelatedToPreviousError (method);
                        Report.Error (82, Location, "A member `{0}' is already reserved",
                                method.GetSignatureForError ());
                        return true;
                }

                public override bool IsUsed
                {
                        get {
                                if (IsDummy)
                                        return false;

                                return base.IsUsed;
                        }
                }

                //
                //   Represents header string for documentation comment.
                //
                public override string DocCommentHeader {
                        get { throw new InvalidOperationException ("Unexpected attempt to get doc comment from " + this.GetType () + "."); }
                }

                void IMethodData.EmitExtraSymbolInfo (SourceMethod source)
                { }
        }

        //
        // Properties and Indexers both generate PropertyBuilders, we use this to share 
        // their common bits.
        //
        abstract public class PropertyBase : PropertyBasedMember {

                public class GetMethod : PropertyMethod
                {
                        static string[] attribute_targets = new string [] { "method", "return" };

                        public GetMethod (PropertyBase method):
                                base (method, "get_")
                        {
                        }

                        public GetMethod (PropertyBase method, Accessor accessor):
                                base (method, accessor, "get_")
                        {
                        }

                        public override MethodBuilder Define (DeclSpace parent)
                        {
                                base.Define (parent);

                                if (IsDummy)
                                        return null;
                                
                                method_data = new MethodData (method, ModFlags, flags, this);

                                if (!method_data.Define (parent, method.GetFullName (MemberName)))
                                        return null;

                                return method_data.MethodBuilder;
                        }

                        public override Type ReturnType {
                                get {
                                        return method.MemberType;
                                }
                        }

                        public override ParametersCompiled ParameterInfo {
                                get {
                                        return ParametersCompiled.EmptyReadOnlyParameters;
                                }
                        }

                        public override string[] ValidAttributeTargets {
                                get {
                                        return attribute_targets;
                                }
                        }
                }

                public class SetMethod : PropertyMethod {

                        static string[] attribute_targets = new string [] { "method", "param", "return" };
                        ImplicitParameter param_attr;
                        protected ParametersCompiled parameters;

                        public SetMethod (PropertyBase method) :
                                base (method, "set_")
                        {
                                parameters = new ParametersCompiled (
                                        new Parameter (method.type_name, "value", Parameter.Modifier.NONE, null, Location));
                        }

                        public SetMethod (PropertyBase method, Accessor accessor):
                                base (method, accessor, "set_")
                        {
                                this.parameters = accessor.Parameters;
                        }

                        protected override void ApplyToExtraTarget (Attribute a, CustomAttributeBuilder cb, PredefinedAttributes pa)
                        {
                                if (a.Target == AttributeTargets.Parameter) {
                                        if (param_attr == null)
                                                param_attr = new ImplicitParameter (method_data.MethodBuilder);

                                        param_attr.ApplyAttributeBuilder (a, cb, pa);
                                        return;
                                }

                                base.ApplyAttributeBuilder (a, cb, pa);
                        }

                        public override ParametersCompiled ParameterInfo {
                            get {
                                return parameters;
                            }
                        }

                        public override MethodBuilder Define (DeclSpace parent)
                        {
                                parameters.Resolve (ResolveContext);
                                
                                base.Define (parent);

                                if (IsDummy)
                                        return null;

                                method_data = new MethodData (method, ModFlags, flags, this);

                                if (!method_data.Define (parent, method.GetFullName (MemberName)))
                                        return null;

                                return method_data.MethodBuilder;
                        }

                        public override Type ReturnType {
                                get {
                                        return TypeManager.void_type;
                                }
                        }

                        public override string[] ValidAttributeTargets {
                                get {
                                        return attribute_targets;
                                }
                        }
                }

                static string[] attribute_targets = new string [] { "property" };

                public abstract class PropertyMethod : AbstractPropertyEventMethod
                {
                        protected readonly PropertyBase method;
                        protected MethodAttributes flags;

                        public PropertyMethod (PropertyBase method, string prefix)
                                : base (method, prefix)
                        {
                                this.method = method;
                                this.ModFlags = method.ModFlags & (Modifiers.STATIC | Modifiers.UNSAFE);                                
                        }

                        public PropertyMethod (PropertyBase method, Accessor accessor,
                                               string prefix)
                                : base (method, accessor, prefix)
                        {
                                this.method = method;
                                this.ModFlags = accessor.ModFlags | (method.ModFlags & (Modifiers.STATIC | Modifiers.UNSAFE));

                                if (accessor.ModFlags != 0 && RootContext.Version == LanguageVersion.ISO_1) {
                                        Report.FeatureIsNotAvailable (Location, "access modifiers on properties");
                                }
                        }

                        public override void ApplyAttributeBuilder (Attribute a, CustomAttributeBuilder cb, PredefinedAttributes pa)
                        {
                                if (a.IsInternalMethodImplAttribute) {
                                        method.is_external_implementation = true;
                                }

                                base.ApplyAttributeBuilder (a, cb, pa);
                        }

                        public override AttributeTargets AttributeTargets {
                                get {
                                        return AttributeTargets.Method;
                                }
                        }

                        public override bool IsClsComplianceRequired ()
                        {
                                return method.IsClsComplianceRequired ();
                        }

                        public virtual MethodBuilder Define (DeclSpace parent)
                        {
                                CheckForDuplications ();

                                if (IsDummy) {
                                        if (method.InterfaceType != null && parent.PartialContainer.PendingImplementations != null) {
                                                MethodInfo mi = parent.PartialContainer.PendingImplementations.IsInterfaceMethod (
                                                        MethodName.Name, method.InterfaceType, new MethodData (method, ModFlags, flags, this));
                                                if (mi != null) {
                                                        Report.SymbolRelatedToPreviousError (mi);
                                                        Report.Error (551, Location, "Explicit interface implementation `{0}' is missing accessor `{1}'",
                                                                method.GetSignatureForError (), TypeManager.CSharpSignature (mi, true));
                                                }
                                        }
                                        return null;
                                }

                                TypeContainer container = parent.PartialContainer;

                                //
                                // Check for custom access modifier
                                //
                                if ((ModFlags & Modifiers.Accessibility) == 0) {
                                        ModFlags |= method.ModFlags;
                                        flags = method.flags;
                                } else {
                                        if (container.Kind == Kind.Interface)
                                                Report.Error (275, Location, "`{0}': accessibility modifiers may not be used on accessors in an interface",
                                                        GetSignatureForError ());

                                        if ((method.ModFlags & Modifiers.ABSTRACT) != 0 && (ModFlags & Modifiers.PRIVATE) != 0) {
                                                Report.Error (442, Location, "`{0}': abstract properties cannot have private accessors", GetSignatureForError ());
                                        }

                                        CheckModifiers (ModFlags);
                                        ModFlags |= (method.ModFlags & (~Modifiers.Accessibility));
                                        ModFlags |= Modifiers.PROPERTY_CUSTOM;
                                        flags = Modifiers.MethodAttr (ModFlags);
                                        flags |= (method.flags & (~MethodAttributes.MemberAccessMask));
                                }

                                CheckAbstractAndExtern (block != null);

                                if (block != null && block.IsIterator)
                                        Iterator.CreateIterator (this, Parent.PartialContainer, ModFlags);

                                return null;
                        }

                        public bool HasCustomAccessModifier {
                                get {
                                        return (ModFlags & Modifiers.PROPERTY_CUSTOM) != 0;
                                }
                        }

                        public PropertyBase Property {
                                get {
                                        return method;
                                }
                        }

                        public override EmitContext CreateEmitContext (DeclSpace ds, ILGenerator ig)
                        {
                                return new EmitContext (this,
                                        ds, method.ds, method.Location, ig, ReturnType,
                                        method.ModFlags, false);
                        }

                        public override ObsoleteAttribute GetObsoleteAttribute ()
                        {
                                return method.GetObsoleteAttribute ();
                        }

                        public override string GetSignatureForError()
                        {
                                return method.GetSignatureForError () + '.' + prefix.Substring (0, 3);
                        }
                        
                        void CheckModifiers (int modflags)
                        {
                                modflags &= Modifiers.Accessibility;
                                int flags = 0;
                                int mflags = method.ModFlags & Modifiers.Accessibility;

                                if ((mflags & Modifiers.PUBLIC) != 0) {
                                        flags |= Modifiers.PROTECTED | Modifiers.INTERNAL | Modifiers.PRIVATE;
                                }
                                else if ((mflags & Modifiers.PROTECTED) != 0) {
                                        if ((mflags & Modifiers.INTERNAL) != 0)
                                                flags |= Modifiers.PROTECTED | Modifiers.INTERNAL;

                                        flags |= Modifiers.PRIVATE;
                                }
                                else if ((mflags & Modifiers.INTERNAL) != 0)
                                        flags |= Modifiers.PRIVATE;

                                if ((mflags == modflags) || (modflags & (~flags)) != 0) {
                                        Report.Error (273, Location,
                                                "The accessibility modifier of the `{0}' accessor must be more restrictive than the modifier of the property or indexer `{1}'",
                                                GetSignatureForError (), method.GetSignatureForError ());
                                }
                        }

                        protected bool CheckForDuplications ()
                        {
                                if ((caching_flags & Flags.MethodOverloadsExist) == 0)
                                        return true;

                                return Parent.MemberCache.CheckExistingMembersOverloads (this, Name, ParameterInfo);
                        }
                }

                public PropertyMethod Get, Set;
                public PropertyBuilder PropertyBuilder;
                public MethodBuilder GetBuilder, SetBuilder;

                protected bool define_set_first = false;

                public PropertyBase (DeclSpace parent, FullNamedExpression type, int mod_flags,
                                     int allowed_mod, MemberName name,
                                     Attributes attrs, bool define_set_first)
                        : base (parent, null, type, mod_flags, allowed_mod, name, attrs)
                {
                         this.define_set_first = define_set_first;
                }

                public override void ApplyAttributeBuilder (Attribute a, CustomAttributeBuilder cb, PredefinedAttributes pa)
                {
                        if (a.HasSecurityAttribute) {
                                a.Error_InvalidSecurityParent ();
                                return;
                        }

                        PropertyBuilder.SetCustomAttribute (cb);
                }

                public override AttributeTargets AttributeTargets {
                        get {
                                return AttributeTargets.Property;
                        }
                }

                protected override void DoMemberTypeDependentChecks ()
                {
                        base.DoMemberTypeDependentChecks ();

                        IsTypePermitted ();
#if MS_COMPATIBLE
                        if (MemberType.IsGenericParameter)
                                return;
#endif

                        if ((MemberType.Attributes & Class.StaticClassAttribute) == Class.StaticClassAttribute) {
                                Report.Error (722, Location, Error722, TypeManager.CSharpName (MemberType));
                        }
                }

                protected override void DoMemberTypeIndependentChecks ()
                {
                        base.DoMemberTypeIndependentChecks ();

                        //
                        // Accessors modifiers check
                        //
                        if ((Get.ModFlags & Modifiers.Accessibility) != 0 &&
                                (Set.ModFlags & Modifiers.Accessibility) != 0) {
                                Report.Error (274, Location, "`{0}': Cannot specify accessibility modifiers for both accessors of the property or indexer",
                                                GetSignatureForError ());
                        }

                        if ((ModFlags & Modifiers.OVERRIDE) == 0 && 
                                (Get.IsDummy && (Set.ModFlags & Modifiers.Accessibility) != 0) ||
                                (Set.IsDummy && (Get.ModFlags & Modifiers.Accessibility) != 0)) {
                                Report.Error (276, Location, 
                                              "`{0}': accessibility modifiers on accessors may only be used if the property or indexer has both a get and a set accessor",
                                              GetSignatureForError ());
                        }
                }

                bool DefineGet ()
                {
                        GetBuilder = Get.Define (Parent);
                        return (Get.IsDummy) ? true : GetBuilder != null;
                }

                bool DefineSet (bool define)
                {
                        if (!define)
                                return true;

                        SetBuilder = Set.Define (Parent);
                        return (Set.IsDummy) ? true : SetBuilder != null;
                }

                protected bool DefineAccessors ()
                {
                        return DefineSet (define_set_first) &&
                                DefineGet () &&
                                DefineSet (!define_set_first);
                }

                protected abstract PropertyInfo ResolveBaseProperty ();

                // TODO: rename to Resolve......
                protected override MethodInfo FindOutBaseMethod (ref Type base_ret_type)
                {
                        PropertyInfo base_property = ResolveBaseProperty ();
                        if (base_property == null)
                                return null;

                        base_ret_type = base_property.PropertyType;
                        MethodInfo get_accessor = base_property.GetGetMethod (true);
                        MethodInfo set_accessor = base_property.GetSetMethod (true);
                        MethodAttributes get_accessor_access = 0, set_accessor_access = 0;

                        //
                        // Check base property accessors conflict
                        //
                        if ((ModFlags & (Modifiers.OVERRIDE | Modifiers.NEW)) == Modifiers.OVERRIDE) {
                                if (get_accessor == null) {
                                        if (Get != null && !Get.IsDummy) {
                                                Report.SymbolRelatedToPreviousError (base_property);
                                                Report.Error (545, Location,
                                                        "`{0}.get': cannot override because `{1}' does not have an overridable get accessor",
                                                        GetSignatureForError (), TypeManager.GetFullNameSignature (base_property));
                                        }
                                } else {
                                        get_accessor_access = get_accessor.Attributes & MethodAttributes.MemberAccessMask;

                                        if (!Get.IsDummy && !CheckAccessModifiers (
                                                Modifiers.MethodAttr (Get.ModFlags) & MethodAttributes.MemberAccessMask, get_accessor_access, get_accessor))
                                                Error_CannotChangeAccessModifiers (Get.Location, get_accessor, get_accessor_access, ".get");
                                }

                                if (set_accessor == null) {
                                        if (Set != null && !Set.IsDummy) {
                                                Report.SymbolRelatedToPreviousError (base_property);
                                                Report.Error (546, Location,
                                                        "`{0}.set': cannot override because `{1}' does not have an overridable set accessor",
                                                        GetSignatureForError (), TypeManager.GetFullNameSignature (base_property));
                                        }
                                } else {
                                        set_accessor_access = set_accessor.Attributes & MethodAttributes.MemberAccessMask;

                                        if (!Set.IsDummy && !CheckAccessModifiers (
                                                Modifiers.MethodAttr (Set.ModFlags) & MethodAttributes.MemberAccessMask, set_accessor_access, set_accessor))
                                                Error_CannotChangeAccessModifiers (Set.Location, set_accessor, set_accessor_access, ".set");
                                }
                        }

                        // When one accessor does not exist and property hides base one
                        // we need to propagate this upwards
                        if (set_accessor == null)
                                set_accessor = get_accessor;

                        //
                        // Get the less restrictive access
                        //
                        return get_accessor_access > set_accessor_access ? get_accessor : set_accessor;
                }

                public override void Emit ()
                {
                        //
                        // The PropertyBuilder can be null for explicit implementations, in that
                        // case, we do not actually emit the ".property", so there is nowhere to
                        // put the attribute
                        //
                        if (PropertyBuilder != null) {
                                if (OptAttributes != null)
                                        OptAttributes.Emit ();

                                if (TypeManager.IsDynamicType (member_type))
                                        PredefinedAttributes.Get.Dynamic.EmitAttribute (PropertyBuilder);
                        }

                        if (!Get.IsDummy)
                                Get.Emit (Parent);

                        if (!Set.IsDummy)
                                Set.Emit (Parent);

                        base.Emit ();
                }

                /// <summary>
                /// Tests whether accessors are not in collision with some method (CS0111)
                /// </summary>
                public bool AreAccessorsDuplicateImplementation (MethodCore mc)
                {
                        return Get.IsDuplicateImplementation (mc) || Set.IsDuplicateImplementation (mc);
                }

                public override bool IsUsed
                {
                        get {
                                if (IsExplicitImpl)
                                        return true;

                                return Get.IsUsed | Set.IsUsed;
                        }
                }

                protected override void SetMemberName (MemberName new_name)
                {
                        base.SetMemberName (new_name);

                        Get.UpdateName (this);
                        Set.UpdateName (this);
                }

                public override string[] ValidAttributeTargets {
                        get {
                                return attribute_targets;
                        }
                }

                //
                //   Represents header string for documentation comment.
                //
                public override string DocCommentHeader {
                        get { return "P:"; }
                }
        }
                        
        public class Property : PropertyBase
        {
                public sealed class BackingField : Field
                {
                        readonly Property property;

                        public BackingField (Property p)
                                : base (p.Parent, p.type_name,
                                Modifiers.BACKING_FIELD | Modifiers.COMPILER_GENERATED | Modifiers.PRIVATE | (p.ModFlags & (Modifiers.STATIC | Modifiers.UNSAFE)),
                                new MemberName ("<" + p.GetFullName (p.MemberName) + ">k__BackingField", p.Location), null)
                        {
                                this.property = p;
                        }

                        public override string GetSignatureForError ()
                        {
                                return property.GetSignatureForError ();
                        }
                }

                const int AllowedModifiers =
                        Modifiers.NEW |
                        Modifiers.PUBLIC |
                        Modifiers.PROTECTED |
                        Modifiers.INTERNAL |
                        Modifiers.PRIVATE |
                        Modifiers.STATIC |
                        Modifiers.SEALED |
                        Modifiers.OVERRIDE |
                        Modifiers.ABSTRACT |
                        Modifiers.UNSAFE |
                        Modifiers.EXTERN |
                        Modifiers.VIRTUAL;

                const int AllowedInterfaceModifiers =
                        Modifiers.NEW;

                public Property (DeclSpace parent, FullNamedExpression type, int mod,
                                 MemberName name, Attributes attrs, Accessor get_block,
                                 Accessor set_block, bool define_set_first)
                        : this (parent, type, mod, name, attrs, get_block, set_block,
                                define_set_first, null)
                {
                }
                
                public Property (DeclSpace parent, FullNamedExpression type, int mod,
                                 MemberName name, Attributes attrs, Accessor get_block,
                                 Accessor set_block, bool define_set_first, Block current_block)
                        : base (parent, type, mod,
                                parent.PartialContainer.Kind == Kind.Interface ? AllowedInterfaceModifiers : AllowedModifiers,
                                name, attrs, define_set_first)
                {
                        if (get_block == null)
                                Get = new GetMethod (this);
                        else
                                Get = new GetMethod (this, get_block);

                        if (set_block == null)
                                Set = new SetMethod (this);
                        else
                                Set = new SetMethod (this, set_block);

                        if (!IsInterface && (mod & (Modifiers.ABSTRACT | Modifiers.EXTERN)) == 0 &&
                                get_block != null && get_block.Block == null &&
                                set_block != null && set_block.Block == null) {
                                if (RootContext.Version <= LanguageVersion.ISO_2)
                                        Report.FeatureIsNotAvailable (Location, "automatically implemented properties");

                                Get.ModFlags |= Modifiers.COMPILER_GENERATED;
                                Set.ModFlags |= Modifiers.COMPILER_GENERATED;
                        }
                }

                void CreateAutomaticProperty ()
                {
                        // Create backing field
                        Field field = new BackingField (this);
                        if (!field.Define ())
                                return;

                        Parent.PartialContainer.AddField (field);

                        FieldExpr fe = new FieldExpr (field.FieldBuilder, Location);
                        if ((field.ModFlags & Modifiers.STATIC) == 0)
                                fe.InstanceExpression = new CompilerGeneratedThis (fe.Type, Location);

                        // Create get block
                        Get.Block = new ToplevelBlock (ParametersCompiled.EmptyReadOnlyParameters, Location);
                        Return r = new Return (fe, Location);
                        Get.Block.AddStatement (r);

                        // Create set block
                        Set.Block = new ToplevelBlock (Set.ParameterInfo, Location);
                        Assign a = new SimpleAssign (fe, new SimpleName ("value", Location));
                        Set.Block.AddStatement (new StatementExpression (a));
                }

                public override bool Define ()
                {
                        if (!base.Define ())
                                return false;

                        flags |= MethodAttributes.HideBySig | MethodAttributes.SpecialName;

                        if ((Get.ModFlags & Modifiers.COMPILER_GENERATED) != 0)
                                CreateAutomaticProperty ();

                        if (!DefineAccessors ())
                                return false;

                        if (!CheckBase ())
                                return false;

                        // FIXME - PropertyAttributes.HasDefault ?

                        PropertyBuilder = Parent.TypeBuilder.DefineProperty (
                                GetFullName (MemberName), PropertyAttributes.None, MemberType, null);

                        if (!Get.IsDummy) {
                                PropertyBuilder.SetGetMethod (GetBuilder);
                                Parent.MemberCache.AddMember (GetBuilder, Get);
                        }

                        if (!Set.IsDummy) {
                                PropertyBuilder.SetSetMethod (SetBuilder);
                                Parent.MemberCache.AddMember (SetBuilder, Set);
                        }
                        
                        TypeManager.RegisterProperty (PropertyBuilder, this);
                        Parent.MemberCache.AddMember (PropertyBuilder, this);
                        return true;
                }

                public override void Emit ()
                {
                        if (((Set.ModFlags | Get.ModFlags) & (Modifiers.STATIC | Modifiers.COMPILER_GENERATED)) == Modifiers.COMPILER_GENERATED && Parent.PartialContainer.HasExplicitLayout) {
                                Report.Error (842, Location,
                                        "Automatically implemented property `{0}' cannot be used inside a type with an explicit StructLayout attribute",
                                        GetSignatureForError ());
                        }

                        base.Emit ();
                }

                protected override PropertyInfo ResolveBaseProperty ()
                {
                        return Parent.PartialContainer.BaseCache.FindMemberToOverride (
                                Parent.TypeBuilder, Name, ParametersCompiled.EmptyReadOnlyParameters, null, true) as PropertyInfo;
                }
        }

        /// </summary>
        ///  Gigantic workaround  for lameness in SRE follows :
        ///  This class derives from EventInfo and attempts to basically
        ///  wrap around the EventBuilder so that FindMembers can quickly
        ///  return this in it search for members
        /// </summary>
        public class MyEventBuilder : EventInfo {
                
                //
                // We use this to "point" to our Builder which is
                // not really a MemberInfo
                //
                EventBuilder MyBuilder;
                
                //
                // We "catch" and wrap these methods
                //
                MethodInfo raise, remove, add;

                EventAttributes attributes;
                Type declaring_type, reflected_type, event_type;
                string name;

                Event my_event;

                public MyEventBuilder (Event ev, TypeBuilder type_builder, string name, EventAttributes event_attr, Type event_type)
                {
                        MyBuilder = type_builder.DefineEvent (name, event_attr, event_type);

                        // And now store the values in our own fields.
                        
                        declaring_type = type_builder;

                        reflected_type = type_builder;
                        
                        attributes = event_attr;
                        this.name = name;
                        my_event = ev;
                        this.event_type = event_type;
                }
                
                //
                // Methods that you have to override.  Note that you only need 
                // to "implement" the variants that take the argument (those are
                // the "abstract" methods, the others (GetAddMethod()) are 
                // regular.
                //
                public override MethodInfo GetAddMethod (bool nonPublic)
                {
                        return add;
                }
                
                public override MethodInfo GetRemoveMethod (bool nonPublic)
                {
                        return remove;
                }
                
                public override MethodInfo GetRaiseMethod (bool nonPublic)
                {
                        return raise;
                }
                
                //
                // These methods make "MyEventInfo" look like a Builder
                //
                public void SetRaiseMethod (MethodBuilder raiseMethod)
                {
                        raise = raiseMethod;
                        MyBuilder.SetRaiseMethod (raiseMethod);
                }

                public void SetRemoveOnMethod (MethodBuilder removeMethod)
                {
                        remove = removeMethod;
                        MyBuilder.SetRemoveOnMethod (removeMethod);
                }

                public void SetAddOnMethod (MethodBuilder addMethod)
                {
                        add = addMethod;
                        MyBuilder.SetAddOnMethod (addMethod);
                }

                public void SetCustomAttribute (CustomAttributeBuilder cb)
                {
                        MyBuilder.SetCustomAttribute (cb);
                }
                
                public override object [] GetCustomAttributes (bool inherit)
                {
                        // FIXME : There's nothing which can be seemingly done here because
                        // we have no way of getting at the custom attribute objects of the
                        // EventBuilder !
                        return null;
                }

                public override object [] GetCustomAttributes (Type t, bool inherit)
                {
                        // FIXME : Same here !
                        return null;
                }

                public override bool IsDefined (Type t, bool b)
                {
                        return true;
                }

                public override EventAttributes Attributes {
                        get {
                                return attributes;
                        }
                }

                public override string Name {
                        get {
                                return name;
                        }
                }

                public override Type DeclaringType {
                        get {
                                return declaring_type;
                        }
                }

                public override Type ReflectedType {
                        get {
                                return reflected_type;
                        }
                }

                public Type EventType {
                        get {
                                return event_type;
                        }
                }
                
                public void SetUsed ()
                {
                        if (my_event != null) {
//                              my_event.SetAssigned ();
                                my_event.SetMemberIsUsed ();
                        }
                }
        }
        
        /// <summary>
        /// For case when event is declared like property (with add and remove accessors).
        /// </summary>
        public class EventProperty: Event {
                abstract class AEventPropertyAccessor : AEventAccessor
                {
                        protected AEventPropertyAccessor (Event method, Accessor accessor, string prefix):
                                base (method, accessor, prefix)
                        {
                        }

                        public override MethodBuilder Define (DeclSpace ds)
                        {
                                CheckAbstractAndExtern (block != null);
                                return base.Define (ds);
                        }
                        
                        public override string GetSignatureForError ()
                        {
                                return method.GetSignatureForError () + "." + prefix.Substring (0, prefix.Length - 1);
                        }
                }

                sealed class AddDelegateMethod: AEventPropertyAccessor
                {
                        public AddDelegateMethod (Event method, Accessor accessor):
                                base (method, accessor, AddPrefix)
                        {
                        }
                }

                sealed class RemoveDelegateMethod: AEventPropertyAccessor
                {
                        public RemoveDelegateMethod (Event method, Accessor accessor):
                                base (method, accessor, RemovePrefix)
                        {
                        }
                }


                static readonly string[] attribute_targets = new string [] { "event" }; // "property" target was disabled for 2.0 version

                public EventProperty (DeclSpace parent, FullNamedExpression type, int mod_flags,
                                      MemberName name,
                                      Attributes attrs, Accessor add, Accessor remove)
                        : base (parent, type, mod_flags, name, attrs)
                {
                        Add = new AddDelegateMethod (this, add);
                        Remove = new RemoveDelegateMethod (this, remove);
                }

                public override bool Define()
                {
                        if (!base.Define ())
                                return false;

                        SetMemberIsUsed ();
                        return true;
                }

                public override string[] ValidAttributeTargets {
                        get {
                                return attribute_targets;
                        }
                }
        }

        /// <summary>
        /// Event is declared like field.
        /// </summary>
        public class EventField : Event {
                abstract class EventFieldAccessor : AEventAccessor
                {
                        protected EventFieldAccessor (Event method, string prefix)
                                : base (method, prefix)
                        {
                        }

                        public override void Emit (DeclSpace parent)
                        {
                                if ((method.ModFlags & (Modifiers.ABSTRACT | Modifiers.EXTERN)) == 0) {
                                        if (parent is Class) {
                                                MethodBuilder mb = method_data.MethodBuilder;
                                                mb.SetImplementationFlags (mb.GetMethodImplementationFlags () | MethodImplAttributes.Synchronized);
                                        }

                                        // TODO: because we cannot use generics yet
                                        FieldInfo field_info = ((EventField) method).BackingField.FieldBuilder;
                                        FieldExpr f_expr = new FieldExpr (field_info, Location);
                                        if ((method.ModFlags & Modifiers.STATIC) == 0)
                                                f_expr.InstanceExpression = new CompilerGeneratedThis (field_info.FieldType, Location);

                                        block = new ToplevelBlock (ParameterInfo, Location);
                                        block.AddStatement (new StatementExpression (
                                                new CompoundAssign (Operation,
                                                        f_expr,
                                                        block.GetParameterReference (ParameterInfo[0].Name, Location))));
                                }

                                base.Emit (parent);
                        }

                        protected abstract Binary.Operator Operation { get; }
                }

                sealed class AddDelegateMethod: EventFieldAccessor
                {
                        public AddDelegateMethod (Event method):
                                base (method, AddPrefix)
                        {
                        }

                        protected override Binary.Operator Operation {
                                get { return Binary.Operator.Addition; }
                        }
                }

                sealed class RemoveDelegateMethod: EventFieldAccessor
                {
                        public RemoveDelegateMethod (Event method):
                                base (method, RemovePrefix)
                        {
                        }

                        protected override Binary.Operator Operation {
                                get { return Binary.Operator.Subtraction; }
                        }
                }


                static readonly string[] attribute_targets = new string [] { "event", "field", "method" };
                static readonly string[] attribute_targets_interface = new string[] { "event", "method" };

                public Field BackingField;
                public Expression Initializer;

                public EventField (DeclSpace parent, FullNamedExpression type, int mod_flags, MemberName name, Attributes attrs)
                        : base (parent, type, mod_flags, name, attrs)
                {
                        Add = new AddDelegateMethod (this);
                        Remove = new RemoveDelegateMethod (this);
                }

                public override void ApplyAttributeBuilder (Attribute a, CustomAttributeBuilder cb, PredefinedAttributes pa)
                {
                        if (a.Target == AttributeTargets.Field) {
                                BackingField.ApplyAttributeBuilder (a, cb, pa);
                                return;
                        }

                        if (a.Target == AttributeTargets.Method) {
                                int errors = Report.Errors;
                                Add.ApplyAttributeBuilder (a, cb, pa);
                                if (errors == Report.Errors)
                                        Remove.ApplyAttributeBuilder (a, cb, pa);
                                return;
                        }

                        base.ApplyAttributeBuilder (a, cb, pa);
                }

                public override bool Define()
                {
                        if (!base.Define ())
                                return false;

                        if (Initializer != null && (ModFlags & Modifiers.ABSTRACT) != 0) {
                                Report.Error (74, Location, "`{0}': abstract event cannot have an initializer",
                                        GetSignatureForError ());
                        }

                        if (!HasBackingField) {
                                SetMemberIsUsed ();
                                return true;
                        }

                        // FIXME: We are unable to detect whether generic event is used because
                        // we are using FieldExpr instead of EventExpr for event access in that
                        // case.  When this issue will be fixed this hack can be removed.
                        if (TypeManager.IsGenericType (MemberType))
                                SetMemberIsUsed ();

                        if (Add.IsInterfaceImplementation)
                                SetMemberIsUsed ();

                        TypeManager.RegisterEventField (EventBuilder, this);

                        BackingField = new Field (Parent,
                                new TypeExpression (MemberType, Location),
                                Modifiers.BACKING_FIELD | Modifiers.COMPILER_GENERATED | Modifiers.PRIVATE | (ModFlags & (Modifiers.STATIC | Modifiers.UNSAFE)),
                                MemberName, null);

                        Parent.PartialContainer.AddField (BackingField);
                        BackingField.Initializer = Initializer;
                        BackingField.ModFlags &= ~Modifiers.COMPILER_GENERATED;

                        // Call define because we passed fields definition
                        return BackingField.Define ();
                }

                bool HasBackingField {
                        get {
                                return !IsInterface && (ModFlags & Modifiers.ABSTRACT) == 0;
                        }
                }

                public override string[] ValidAttributeTargets 
                {
                        get {
                                return HasBackingField ? attribute_targets : attribute_targets_interface;
                        }
                }
        }

        public abstract class Event : PropertyBasedMember {
                public abstract class AEventAccessor : AbstractPropertyEventMethod
                {
                        protected readonly Event method;
                        ImplicitParameter param_attr;

                        static readonly string[] attribute_targets = new string [] { "method", "param", "return" };

                        public const string AddPrefix = "add_";
                        public const string RemovePrefix = "remove_";

                        protected AEventAccessor (Event method, string prefix)
                                : base (method, prefix)
                        {
                                this.method = method;
                                this.ModFlags = method.ModFlags;
                        }

                        protected AEventAccessor (Event method, Accessor accessor, string prefix)
                                : base (method, accessor, prefix)
                        {
                                this.method = method;
                                this.ModFlags = method.ModFlags;
                        }

                        public bool IsInterfaceImplementation {
                                get { return method_data.implementing != null; }
                        }

                        public override void ApplyAttributeBuilder (Attribute a, CustomAttributeBuilder cb, PredefinedAttributes pa)
                        {
                                if (a.IsInternalMethodImplAttribute) {
                                        method.is_external_implementation = true;
                                }

                                base.ApplyAttributeBuilder (a, cb, pa);
                        }

                        protected override void ApplyToExtraTarget (Attribute a, CustomAttributeBuilder cb, PredefinedAttributes pa)
                        {
                                if (a.Target == AttributeTargets.Parameter) {
                                        if (param_attr == null)
                                                param_attr = new ImplicitParameter (method_data.MethodBuilder);

                                        param_attr.ApplyAttributeBuilder (a, cb, pa);
                                        return;
                                }

                                base.ApplyAttributeBuilder (a, cb, pa);
                        }

                        public override AttributeTargets AttributeTargets {
                                get {
                                        return AttributeTargets.Method;
                                }
                        }

                        public override bool IsClsComplianceRequired ()
                        {
                                return method.IsClsComplianceRequired ();
                        }

                        public virtual MethodBuilder Define (DeclSpace parent)
                        {
                                method_data = new MethodData (method, method.ModFlags,
                                        method.flags | MethodAttributes.HideBySig | MethodAttributes.SpecialName, this);

                                if (!method_data.Define (parent, method.GetFullName (MemberName)))
                                        return null;

                                MethodBuilder mb = method_data.MethodBuilder;
                                ParameterInfo.ApplyAttributes (mb);
                                return mb;
                        }

                        public override Type ReturnType {
                                get {
                                        return TypeManager.void_type;
                                }
                        }

                        public override EmitContext CreateEmitContext (DeclSpace ds, ILGenerator ig)
                        {
                                return new EmitContext (
                                        this, method.Parent, Location, ig, ReturnType,
                                        method.ModFlags, false);
                        }

                        public override ObsoleteAttribute GetObsoleteAttribute ()
                        {
                                return method.GetObsoleteAttribute ();
                        }

                        public override string[] ValidAttributeTargets {
                                get {
                                        return attribute_targets;
                                }
                        }

                        public override ParametersCompiled ParameterInfo {
                                get {
                                        return method.parameters;
                                }
                        }
                }


                const int AllowedModifiers =
                        Modifiers.NEW |
                        Modifiers.PUBLIC |
                        Modifiers.PROTECTED |
                        Modifiers.INTERNAL |
                        Modifiers.PRIVATE |
                        Modifiers.STATIC |
                        Modifiers.VIRTUAL |
                        Modifiers.SEALED |
                        Modifiers.OVERRIDE |
                        Modifiers.UNSAFE |
                        Modifiers.ABSTRACT |
                        Modifiers.EXTERN;

                const int AllowedInterfaceModifiers =
                        Modifiers.NEW;

                public AEventAccessor Add, Remove;
                public MyEventBuilder     EventBuilder;
                public MethodBuilder AddBuilder, RemoveBuilder;

                ParametersCompiled parameters;

                protected Event (DeclSpace parent, FullNamedExpression type, int mod_flags, MemberName name, Attributes attrs)
                        : base (parent, null, type, mod_flags,
                                parent.PartialContainer.Kind == Kind.Interface ? AllowedInterfaceModifiers : AllowedModifiers,
                                name, attrs)
                {
                }

                public override void ApplyAttributeBuilder (Attribute a, CustomAttributeBuilder cb, PredefinedAttributes pa)
                {
                        if ((a.HasSecurityAttribute)) {
                                a.Error_InvalidSecurityParent ();
                                return;
                        }
                        
                        EventBuilder.SetCustomAttribute (cb);
                }

                public bool AreAccessorsDuplicateImplementation (MethodCore mc)
                {
                        return Add.IsDuplicateImplementation (mc) || Remove.IsDuplicateImplementation (mc);
                }

                public override AttributeTargets AttributeTargets {
                        get {
                                return AttributeTargets.Event;
                        }
                }

                public override bool Define ()
                {
                        if (!base.Define ())
                                return false;

                        if (!TypeManager.IsDelegateType (MemberType)) {
                                Report.Error (66, Location, "`{0}': event must be of a delegate type", GetSignatureForError ());
                        }

                        parameters = ParametersCompiled.CreateFullyResolved (
                                new Parameter (null, "value", Parameter.Modifier.NONE, null, Location), MemberType);

                        if (!CheckBase ())
                                return false;

                        if (TypeManager.delegate_combine_delegate_delegate == null) {
                                TypeManager.delegate_combine_delegate_delegate = TypeManager.GetPredefinedMethod (
                                        TypeManager.delegate_type, "Combine", Location,
                                        TypeManager.delegate_type, TypeManager.delegate_type);
                        }
                        if (TypeManager.delegate_remove_delegate_delegate == null) {
                                TypeManager.delegate_remove_delegate_delegate = TypeManager.GetPredefinedMethod (
                                        TypeManager.delegate_type, "Remove", Location,
                                        TypeManager.delegate_type, TypeManager.delegate_type);
                        }

                        //
                        // Now define the accessors
                        //

                        AddBuilder = Add.Define (Parent);
                        if (AddBuilder == null)
                                return false;

                        RemoveBuilder = Remove.Define (Parent);
                        if (RemoveBuilder == null)
                                return false;

                        EventBuilder = new MyEventBuilder (this, Parent.TypeBuilder, Name, EventAttributes.None, MemberType);                                           
                        EventBuilder.SetAddOnMethod (AddBuilder);
                        EventBuilder.SetRemoveOnMethod (RemoveBuilder);

                        Parent.MemberCache.AddMember (EventBuilder, this);
                        Parent.MemberCache.AddMember (AddBuilder, Add);
                        Parent.MemberCache.AddMember (RemoveBuilder, Remove);
                        
                        return true;
                }

                public override void Emit ()
                {
                        if (OptAttributes != null) {
                                OptAttributes.Emit ();
                        }

                        Add.Emit (Parent);
                        Remove.Emit (Parent);

                        base.Emit ();
                }

                protected override MethodInfo FindOutBaseMethod (ref Type base_ret_type)
                {
                        MethodInfo mi = (MethodInfo) Parent.PartialContainer.BaseCache.FindBaseEvent (
                                Parent.TypeBuilder, Name);

                        if (mi == null)
                                return null;

                        AParametersCollection pd = TypeManager.GetParameterData (mi);
                        base_ret_type = pd.Types [0];
                        return mi;
                }

                //
                //   Represents header string for documentation comment.
                //
                public override string DocCommentHeader {
                        get { return "E:"; }
                }
        }

 
        public class Indexer : PropertyBase
        {
                public class GetIndexerMethod : GetMethod
                {
                        ParametersCompiled parameters;

                        public GetIndexerMethod (Indexer method):
                                base (method)
                        {
                                this.parameters = method.parameters;
                        }

                        public GetIndexerMethod (PropertyBase method, Accessor accessor):
                                base (method, accessor)
                        {
                                parameters = accessor.Parameters;
                        }

                        public override MethodBuilder Define (DeclSpace parent)
                        {
                                parameters.Resolve (ResolveContext);
                                return base.Define (parent);
                        }
                        
                        public override bool EnableOverloadChecks (MemberCore overload)
                        {
                                if (base.EnableOverloadChecks (overload)) {
                                        overload.caching_flags |= Flags.MethodOverloadsExist;
                                        return true;
                                }

                                return false;
                        }                       

                        public override ParametersCompiled ParameterInfo {
                                get {
                                        return parameters;
                                }
                        }
                }

                public class SetIndexerMethod: SetMethod
                {
                        public SetIndexerMethod (Indexer method):
                                base (method)
                        {
                                parameters = ParametersCompiled.MergeGenerated (method.parameters, false, parameters [0], null);
                        }

                        public SetIndexerMethod (PropertyBase method, Accessor accessor):
                                base (method, accessor)
                        {
                                parameters = method.Get.IsDummy ? accessor.Parameters : accessor.Parameters.Clone ();                   
                        }

                        public override bool EnableOverloadChecks (MemberCore overload)
                        {
                                if (base.EnableOverloadChecks (overload)) {
                                        overload.caching_flags |= Flags.MethodOverloadsExist;
                                        return true;
                                }

                                return false;
                        }
                }

                const int AllowedModifiers =
                        Modifiers.NEW |
                        Modifiers.PUBLIC |
                        Modifiers.PROTECTED |
                        Modifiers.INTERNAL |
                        Modifiers.PRIVATE |
                        Modifiers.VIRTUAL |
                        Modifiers.SEALED |
                        Modifiers.OVERRIDE |
                        Modifiers.UNSAFE |
                        Modifiers.EXTERN |
                        Modifiers.ABSTRACT;

                const int AllowedInterfaceModifiers =
                        Modifiers.NEW;

                public readonly ParametersCompiled parameters;

                public Indexer (DeclSpace parent, FullNamedExpression type, MemberName name, int mod,
                                ParametersCompiled parameters, Attributes attrs,
                                Accessor get_block, Accessor set_block, bool define_set_first)
                        : base (parent, type, mod,
                                parent.PartialContainer.Kind == Kind.Interface ? AllowedInterfaceModifiers : AllowedModifiers,
                                name, attrs, define_set_first)
                {
                        this.parameters = parameters;

                        if (get_block == null)
                                Get = new GetIndexerMethod (this);
                        else
                                Get = new GetIndexerMethod (this, get_block);

                        if (set_block == null)
                                Set = new SetIndexerMethod (this);
                        else
                                Set = new SetIndexerMethod (this, set_block);
                }

                protected override bool CheckForDuplications ()
                {
                        return Parent.MemberCache.CheckExistingMembersOverloads (this, GetFullName (MemberName), parameters);
                }
                
                public override bool Define ()
                {
                        if (!base.Define ())
                                return false;

                        if (!DefineParameters (parameters))
                                return false;

                        if (OptAttributes != null) {
                                Attribute indexer_attr = OptAttributes.Search (PredefinedAttributes.Get.IndexerName);
                                if (indexer_attr != null) {
                                        // Remove the attribute from the list because it is not emitted
                                        OptAttributes.Attrs.Remove (indexer_attr);

                                        string name = indexer_attr.GetIndexerAttributeValue ();
                                        if (name == null)
                                                return false;

                                        ShortName = name;

                                        if (IsExplicitImpl) {
                                                Report.Error (415, indexer_attr.Location,
                                                              "The `IndexerName' attribute is valid only on an " +
                                                              "indexer that is not an explicit interface member declaration");
                                                return false;
                                        }

                                        if ((ModFlags & Modifiers.OVERRIDE) != 0) {
                                                Report.Error (609, indexer_attr.Location,
                                                              "Cannot set the `IndexerName' attribute on an indexer marked override");
                                                return false;
                                        }
                                }
                        }

                        if (InterfaceType != null) {
                                string base_IndexerName = TypeManager.IndexerPropertyName (InterfaceType);
                                if (base_IndexerName != Name)
                                        ShortName = base_IndexerName;
                        }

                        if (!Parent.PartialContainer.AddMember (this) ||
                                !Parent.PartialContainer.AddMember (Get) || !Parent.PartialContainer.AddMember (Set))
                                return false;

                        flags |= MethodAttributes.HideBySig | MethodAttributes.SpecialName;
                        
                        if (!DefineAccessors ())
                                return false;

                        if (!CheckBase ())
                                return false;

                        //
                        // Now name the parameters
                        //
                        PropertyBuilder = Parent.TypeBuilder.DefineProperty (
                                GetFullName (MemberName), PropertyAttributes.None, MemberType, parameters.GetEmitTypes ());

                        if (!Get.IsDummy) {
                                PropertyBuilder.SetGetMethod (GetBuilder);
                                Parent.MemberCache.AddMember (GetBuilder, Get);
                        }

                        if (!Set.IsDummy) {
                                PropertyBuilder.SetSetMethod (SetBuilder);
                                Parent.MemberCache.AddMember (SetBuilder, Set);
                        }
                                
                        TypeManager.RegisterIndexer (PropertyBuilder, parameters);
                        Parent.MemberCache.AddMember (PropertyBuilder, this);
                        return true;
                }

                public override bool EnableOverloadChecks (MemberCore overload)
                {
                        if (overload is Indexer) {
                                caching_flags |= Flags.MethodOverloadsExist;
                                return true;
                        }

                        return base.EnableOverloadChecks (overload);
                }

                public override string GetDocCommentName (DeclSpace ds)
                {
                        return DocUtil.GetMethodDocCommentName (this, parameters, ds);
                }

                public override string GetSignatureForError ()
                {
                        StringBuilder sb = new StringBuilder (Parent.GetSignatureForError ());
                        if (MemberName.Left != null) {
                                sb.Append ('.');
                                sb.Append (MemberName.Left.GetSignatureForError ());
                        }

                        sb.Append (".this");
                        sb.Append (parameters.GetSignatureForError ().Replace ('(', '[').Replace (')', ']'));
                        return sb.ToString ();
                }

                protected override PropertyInfo ResolveBaseProperty ()
                {
                        return Parent.PartialContainer.BaseCache.FindMemberToOverride (
                                Parent.TypeBuilder, Name, parameters, null, true) as PropertyInfo;
                }

                protected override bool VerifyClsCompliance ()
                {
                        if (!base.VerifyClsCompliance ())
                                return false;

                        parameters.VerifyClsCompliance ();
                        return true;
                }
        }

        public class Operator : MethodOrOperator {

                const int AllowedModifiers =
                        Modifiers.PUBLIC |
                        Modifiers.UNSAFE |
                        Modifiers.EXTERN |
                        Modifiers.STATIC;

                public enum OpType : byte {

                        // Unary operators
                        LogicalNot,
                        OnesComplement,
                        Increment,
                        Decrement,
                        True,
                        False,

                        // Unary and Binary operators
                        Addition,
                        Subtraction,

                        UnaryPlus,
                        UnaryNegation,
                        
                        // Binary operators
                        Multiply,
                        Division,
                        Modulus,
                        BitwiseAnd,
                        BitwiseOr,
                        ExclusiveOr,
                        LeftShift,
                        RightShift,
                        Equality,
                        Inequality,
                        GreaterThan,
                        LessThan,
                        GreaterThanOrEqual,
                        LessThanOrEqual,

                        // Implicit and Explicit
                        Implicit,
                        Explicit,

                        // Just because of enum
                        TOP
                };

                public readonly OpType OperatorType;

                static readonly string [] [] names;

                static Operator ()
                {
                        names = new string[(int)OpType.TOP][];
                        names [(int) OpType.LogicalNot] = new string [] { "!", "op_LogicalNot" };
                        names [(int) OpType.OnesComplement] = new string [] { "~", "op_OnesComplement" };
                        names [(int) OpType.Increment] = new string [] { "++", "op_Increment" };
                        names [(int) OpType.Decrement] = new string [] { "--", "op_Decrement" };
                        names [(int) OpType.True] = new string [] { "true", "op_True" };
                        names [(int) OpType.False] = new string [] { "false", "op_False" };
                        names [(int) OpType.Addition] = new string [] { "+", "op_Addition" };
                        names [(int) OpType.Subtraction] = new string [] { "-", "op_Subtraction" };
                        names [(int) OpType.UnaryPlus] = new string [] { "+", "op_UnaryPlus" };
                        names [(int) OpType.UnaryNegation] = new string [] { "-", "op_UnaryNegation" };
                        names [(int) OpType.Multiply] = new string [] { "*", "op_Multiply" };
                        names [(int) OpType.Division] = new string [] { "/", "op_Division" };
                        names [(int) OpType.Modulus] = new string [] { "%", "op_Modulus" };
                        names [(int) OpType.BitwiseAnd] = new string [] { "&", "op_BitwiseAnd" };
                        names [(int) OpType.BitwiseOr] = new string [] { "|", "op_BitwiseOr" };
                        names [(int) OpType.ExclusiveOr] = new string [] { "^", "op_ExclusiveOr" };
                        names [(int) OpType.LeftShift] = new string [] { "<<", "op_LeftShift" };
                        names [(int) OpType.RightShift] = new string [] { ">>", "op_RightShift" };
                        names [(int) OpType.Equality] = new string [] { "==", "op_Equality" };
                        names [(int) OpType.Inequality] = new string [] { "!=", "op_Inequality" };
                        names [(int) OpType.GreaterThan] = new string [] { ">", "op_GreaterThan" };
                        names [(int) OpType.LessThan] = new string [] { "<", "op_LessThan" };
                        names [(int) OpType.GreaterThanOrEqual] = new string [] { ">=", "op_GreaterThanOrEqual" };
                        names [(int) OpType.LessThanOrEqual] = new string [] { "<=", "op_LessThanOrEqual" };
                        names [(int) OpType.Implicit] = new string [] { "implicit", "op_Implicit" };
                        names [(int) OpType.Explicit] = new string [] { "explicit", "op_Explicit" };
                }
                
                public Operator (DeclSpace parent, OpType type, FullNamedExpression ret_type,
                                 int mod_flags, ParametersCompiled parameters,
                                 ToplevelBlock block, Attributes attrs, Location loc)
                        : base (parent, null, ret_type, mod_flags, AllowedModifiers,
                                new MemberName (GetMetadataName (type), loc), attrs, parameters)
                {
                        OperatorType = type;
                        Block = block;
                }

                public override void ApplyAttributeBuilder (Attribute a, CustomAttributeBuilder cb, PredefinedAttributes pa)
                {
                        if (a.Type == pa.Conditional) {
                                Error_ConditionalAttributeIsNotValid ();
                                return;
                        }

                        base.ApplyAttributeBuilder (a, cb, pa);
                }
                
                public override bool Define ()
                {
                        const int RequiredModifiers = Modifiers.PUBLIC | Modifiers.STATIC;
                        if ((ModFlags & RequiredModifiers) != RequiredModifiers){
                                Report.Error (558, Location, "User-defined operator `{0}' must be declared static and public", GetSignatureForError ());
                        }

                        if (!base.Define ())
                                return false;

                        // imlicit and explicit operator of same types are not allowed
                        if (OperatorType == OpType.Explicit)
                                Parent.MemberCache.CheckExistingMembersOverloads (this, GetMetadataName (OpType.Implicit), Parameters);
                        else if (OperatorType == OpType.Implicit)
                                Parent.MemberCache.CheckExistingMembersOverloads (this, GetMetadataName (OpType.Explicit), Parameters);

                        Type declaring_type = MethodData.DeclaringType;
                        Type return_type = MemberType;
                        Type first_arg_type = ParameterTypes [0];
                        
                        Type first_arg_type_unwrap = first_arg_type;
                        if (TypeManager.IsNullableType (first_arg_type))
                                first_arg_type_unwrap = TypeManager.TypeToCoreType (TypeManager.GetTypeArguments (first_arg_type) [0]);
                        
                        Type return_type_unwrap = return_type;
                        if (TypeManager.IsNullableType (return_type))
                                return_type_unwrap = TypeManager.TypeToCoreType (TypeManager.GetTypeArguments (return_type) [0]);

                        if (TypeManager.IsDynamicType (return_type) || TypeManager.IsDynamicType (first_arg_type)) {
                                Report.Error (1964, Location,
                                        "User-defined operator `{0}' cannot convert to or from the dynamic type",
                                        GetSignatureForError ());

                                return false;
                        }

                        //
                        // Rules for conversion operators
                        //
                        if (OperatorType == OpType.Implicit || OperatorType == OpType.Explicit) {
                                if (first_arg_type_unwrap == return_type_unwrap && first_arg_type_unwrap == declaring_type){
                                        Report.Error (555, Location,
                                                "User-defined operator cannot take an object of the enclosing type and convert to an object of the enclosing type");
                                        return false;
                                }
                                
                                Type conv_type;
                                if (TypeManager.IsEqual (declaring_type, return_type) || declaring_type == return_type_unwrap) {
                                        conv_type = first_arg_type;
                                } else if (TypeManager.IsEqual (declaring_type, first_arg_type) || declaring_type == first_arg_type_unwrap) {
                                        conv_type = return_type;
                                } else {
                                        Report.Error (556, Location, 
                                                "User-defined conversion must convert to or from the enclosing type");
                                        return false;
                                }

                                //
                                // Because IsInterface and IsClass are not supported
                                //
                                if (!TypeManager.IsGenericParameter (conv_type)) {
                                        if (conv_type.IsInterface) {
                                                Report.Error (552, Location, "User-defined conversion `{0}' cannot convert to or from an interface type",
                                                        GetSignatureForError ());
                                                return false;
                                        }

                                        if (conv_type.IsClass) {
                                                if (TypeManager.IsSubclassOf (declaring_type, conv_type)) {
                                                        Report.Error (553, Location, "User-defined conversion `{0}' cannot convert to or from a base class",
                                                                GetSignatureForError ());
                                                        return false;
                                                }

                                                if (TypeManager.IsSubclassOf (conv_type, declaring_type)) {
                                                        Report.Error (554, Location, "User-defined conversion `{0}' cannot convert to or from a derived class",
                                                                GetSignatureForError ());
                                                        return false;
                                                }
                                        }
                                }
                        } else if (OperatorType == OpType.LeftShift || OperatorType == OpType.RightShift) {
                                if (first_arg_type != declaring_type || Parameters.Types [1] != TypeManager.int32_type) {
                                        Report.Error (564, Location, "Overloaded shift operator must have the type of the first operand be the containing type, and the type of the second operand must be int");
                                        return false;
                                }
                        } else if (Parameters.Count == 1) {
                                // Checks for Unary operators

                                if (OperatorType == OpType.Increment || OperatorType == OpType.Decrement) {
                                        if (return_type != declaring_type && !TypeManager.IsSubclassOf (return_type, declaring_type)) {
                                                Report.Error (448, Location,
                                                        "The return type for ++ or -- operator must be the containing type or derived from the containing type");
                                                return false;
                                        }
                                        if (first_arg_type != declaring_type) {
                                                Report.Error (
                                                        559, Location, "The parameter type for ++ or -- operator must be the containing type");
                                                return false;
                                        }
                                }
                                
                                if (!TypeManager.IsEqual (first_arg_type_unwrap, declaring_type)){
                                        Report.Error (562, Location,
                                                "The parameter type of a unary operator must be the containing type");
                                        return false;
                                }
                                
                                if (OperatorType == OpType.True || OperatorType == OpType.False) {
                                        if (return_type != TypeManager.bool_type){
                                                Report.Error (
                                                        215, Location,
                                                        "The return type of operator True or False " +
                                                        "must be bool");
                                                return false;
                                        }
                                }
                                
                        } else {
                                // Checks for Binary operators
                                
                                if (first_arg_type != declaring_type &&
                                    Parameters.Types [1] != declaring_type){
                                        Report.Error (
                                                563, Location,
                                                "One of the parameters of a binary operator must " +
                                                "be the containing type");
                                        return false;
                                }
                        }

                        return true;
                }

                protected override bool ResolveMemberType ()
                {
                        if (!base.ResolveMemberType ())
                                return false;

                        flags |= MethodAttributes.SpecialName | MethodAttributes.HideBySig;
                        return true;
                }

                // Operator cannot be override
                protected override MethodInfo FindOutBaseMethod (ref Type base_ret_type)
                {
                        return null;
                }

                public static string GetName (OpType ot)
                {
                        return names [(int) ot] [0];
                }

                public static string GetName (string metadata_name)
                {
                        for (int i = 0; i < names.Length; ++i) {
                                if (names [i] [1] == metadata_name)
                                        return names [i] [0];
                        }
                        return null;
                }

                public static string GetMetadataName (OpType ot)
                {
                        return names [(int) ot] [1];
                }

                public static string GetMetadataName (string name)
                {
                        for (int i = 0; i < names.Length; ++i) {
                                if (names [i] [0] == name)
                                        return names [i] [1];
                        }
                        return null;
                }

                public OpType GetMatchingOperator ()
                {
                        switch (OperatorType) {
                        case OpType.Equality:
                                return OpType.Inequality;
                        case OpType.Inequality:
                                return OpType.Equality;
                        case OpType.True:
                                return OpType.False;
                        case OpType.False:
                                return OpType.True;
                        case OpType.GreaterThan:
                                return OpType.LessThan;
                        case OpType.LessThan:
                                return OpType.GreaterThan;
                        case OpType.GreaterThanOrEqual:
                                return OpType.LessThanOrEqual;
                        case OpType.LessThanOrEqual:
                                return OpType.GreaterThanOrEqual;
                        default:
                                return OpType.TOP;
                        }
                }

                public override string GetSignatureForError ()
                {
                        StringBuilder sb = new StringBuilder ();
                        if (OperatorType == OpType.Implicit || OperatorType == OpType.Explicit) {
                                sb.AppendFormat ("{0}.{1} operator {2}",
                                        Parent.GetSignatureForError (), GetName (OperatorType), type_name.GetSignatureForError ());
                        }
                        else {
                                sb.AppendFormat ("{0}.operator {1}", Parent.GetSignatureForError (), GetName (OperatorType));
                        }

                        sb.Append (Parameters.GetSignatureForError ());
                        return sb.ToString ();
                }
        }

        //
        // This is used to compare method signatures
        //
        struct MethodSignature {
                public string Name;
                public Type RetType;
                public Type [] Parameters;
                
                /// <summary>
                ///    This delegate is used to extract methods which have the
                ///    same signature as the argument
                /// </summary>
                public static MemberFilter method_signature_filter = new MemberFilter (MemberSignatureCompare);
                
                public MethodSignature (string name, Type ret_type, Type [] parameters)
                {
                        Name = name;
                        RetType = ret_type;

                        if (parameters == null)
                                Parameters = Type.EmptyTypes;
                        else
                                Parameters = parameters;
                }

                public override string ToString ()
                {
                        string pars = "";
                        if (Parameters.Length != 0){
                                System.Text.StringBuilder sb = new System.Text.StringBuilder ();
                                for (int i = 0; i < Parameters.Length; i++){
                                        sb.Append (Parameters [i]);
                                        if (i+1 < Parameters.Length)
                                                sb.Append (", ");
                                }
                                pars = sb.ToString ();
                        }

                        return String.Format ("{0} {1} ({2})", RetType, Name, pars);
                }
                
                public override int GetHashCode ()
                {
                        return Name.GetHashCode ();
                }

                public override bool Equals (Object o)
                {
                        MethodSignature other = (MethodSignature) o;

                        if (other.Name != Name)
                                return false;

                        if (other.RetType != RetType)
                                return false;
                        
                        if (Parameters == null){
                                if (other.Parameters == null)
                                        return true;
                                return false;
                        }

                        if (other.Parameters == null)
                                return false;
                        
                        int c = Parameters.Length;
                        if (other.Parameters.Length != c)
                                return false;

                        for (int i = 0; i < c; i++)
                                if (other.Parameters [i] != Parameters [i])
                                        return false;

                        return true;
                }

                static bool MemberSignatureCompare (MemberInfo m, object filter_criteria)
                {
                        MethodSignature sig = (MethodSignature) filter_criteria;

                        if (m.Name != sig.Name)
                                return false;

                        Type ReturnType;
                        MethodInfo mi = m as MethodInfo;
                        PropertyInfo pi = m as PropertyInfo;

                        if (mi != null)
                                ReturnType = mi.ReturnType;
                        else if (pi != null)
                                ReturnType = pi.PropertyType;
                        else
                                return false;

                        //
                        // we use sig.RetType == null to mean `do not check the
                        // method return value.  
                        //
                        if (sig.RetType != null) {
                                if (!TypeManager.IsEqual (ReturnType, sig.RetType))
                                        return false;
                        }

                        Type [] args;
                        if (mi != null)
                                args = TypeManager.GetParameterData (mi).Types;
                        else
                                args = TypeManager.GetParameterData (pi).Types;
                        Type [] sigp = sig.Parameters;

                        if (args.Length != sigp.Length)
                                return false;

                        for (int i = args.Length - 1; i >= 0; i--)
                                if (!TypeManager.IsEqual (args [i], sigp [i]))
                                        return false;

                        return true;
                }
        }
}