Fix sequence points for more statements
[mono.git] / mcs / mcs / method.cs
index 130452b6da73410ce02f4cc0f9dcaa564e863d6e..c33050915f0094c3c1b86c07413379af78dd8dbb 100644 (file)
@@ -9,6 +9,7 @@
 //
 // Copyright 2001, 2002, 2003 Ximian, Inc (http://www.ximian.com)
 // Copyright 2004-2008 Novell, Inc
+// Copyright 2011 Xamarin Inc.
 //
 
 using System;
@@ -46,10 +47,9 @@ namespace Mono.CSharp {
                protected ToplevelBlock block;
                protected MethodSpec spec;
 
-               public MethodCore (DeclSpace parent, GenericMethod generic,
-                       FullNamedExpression type, Modifiers mod, Modifiers allowed_mod,
+               public MethodCore (TypeDefinition parent, FullNamedExpression type, Modifiers mod, Modifiers allowed_mod,
                        MemberName name, Attributes attrs, ParametersCompiled parameters)
-                       : base (parent, generic, type, mod, allowed_mod, name, attrs)
+                       : base (parent, type, mod, allowed_mod, name, attrs)
                {
                        this.parameters = parameters;
                }
@@ -517,11 +517,9 @@ namespace Mono.CSharp {
 
                static readonly string[] attribute_targets = new string [] { "method", "return" };
 
-               protected MethodOrOperator (DeclSpace parent, GenericMethod generic, FullNamedExpression type, Modifiers mod,
-                               Modifiers allowed_mod, MemberName name,
+               protected MethodOrOperator (TypeDefinition parent, FullNamedExpression type, Modifiers mod, Modifiers allowed_mod, MemberName name,
                                Attributes attrs, ParametersCompiled parameters)
-                       : base (parent, generic, type, mod, allowed_mod, name,
-                                       attrs, parameters)
+                       : base (parent, type, mod, allowed_mod, name, attrs, parameters)
                {
                }
 
@@ -611,9 +609,9 @@ namespace Mono.CSharp {
                        }
 
                        MethodData = new MethodData (
-                               this, ModFlags, flags, this, MethodBuilder, GenericMethod, base_method);
+                               this, ModFlags, flags, this, MethodBuilder, base_method);
 
-                       if (!MethodData.Define (Parent.PartialContainer, GetFullName (MemberName), Report))
+                       if (!MethodData.Define (Parent.PartialContainer, GetFullName (MemberName)))
                                return false;
                                        
                        MethodBuilder = MethodData.MethodBuilder;
@@ -776,15 +774,6 @@ namespace Mono.CSharp {
                        return conditions;
                }
 
-               GenericMethod IMethodData.GenericMethod {
-                       get {
-                               return GenericMethod;
-                       }
-               }
-
-               public virtual void EmitExtraSymbolInfo (SourceMethod source)
-               { }
-
                #endregion
 
        }
@@ -792,13 +781,11 @@ namespace Mono.CSharp {
        public class SourceMethod : IMethodDef
        {
                MethodBase method;
-               SourceMethodBuilder builder;
 
-               protected SourceMethod (DeclSpace parent, MethodBase method, ICompileUnit file)
+               SourceMethod (MethodBase method, ICompileUnit file)
                {
                        this.method = method;
-                       
-                       builder = SymbolWriter.OpenMethod (file, parent.NamespaceEntry.SymbolFileID, this);
+                       SymbolWriter.OpenMethod (file, this);
                }
 
                public string Name {
@@ -826,28 +813,16 @@ namespace Mono.CSharp {
                        SymbolWriter.CloseMethod ();
                }
 
-               public void SetRealMethodName (string name)
-               {
-                       if (builder != null)
-                               builder.SetRealMethodName (name);
-               }
-
-               public static SourceMethod Create (DeclSpace parent, MethodBase method, Block block)
+               public static SourceMethod Create (TypeDefinition parent, MethodBase method)
                {
                        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)
+                       var source_file = parent.GetCompilationSourceFile ();
+                       if (source_file == null)
                                return null;
 
-                       return new SourceMethod (parent, method, compile_unit);
+                       return new SourceMethod (method, source_file.SymbolUnitEntry);
                }
        }
 
@@ -855,10 +830,8 @@ namespace Mono.CSharp {
        {
                Method partialMethodImplementation;
 
-               public Method (DeclSpace parent, GenericMethod generic,
-                              FullNamedExpression return_type, Modifiers mod,
-                              MemberName name, ParametersCompiled parameters, Attributes attrs)
-                       : base (parent, generic, return_type, mod,
+               public Method (TypeDefinition parent, FullNamedExpression return_type, Modifiers mod, MemberName name, ParametersCompiled parameters, Attributes attrs)
+                       : base (parent, return_type, mod,
                                parent.PartialContainer.Kind == MemberKind.Interface ? AllowedModifiersInterface :
                                parent.PartialContainer.Kind == MemberKind.Struct ? AllowedModifiersStruct | Modifiers.ASYNC :
                                AllowedModifiersClass | Modifiers.ASYNC,
@@ -866,38 +839,75 @@ namespace Mono.CSharp {
                {
                }
 
-               protected Method (DeclSpace parent, FullNamedExpression return_type, Modifiers mod, Modifiers amod,
+               protected Method (TypeDefinition parent, FullNamedExpression return_type, Modifiers mod, Modifiers amod,
                                        MemberName name, ParametersCompiled parameters, Attributes attrs)
-                       : base (parent, null, return_type, mod, amod, name, attrs, parameters)
+                       : base (parent, return_type, mod, amod, name, attrs, parameters)
                {
                }
 
                #region Properties
 
-               public override TypeParameter[] CurrentTypeParameters {
+               public override TypeParameters CurrentTypeParameters {
                        get {
-                               if (GenericMethod != null)
-                                       return GenericMethod.CurrentTypeParameters;
-
-                               return null;
+                               return MemberName.TypeParameters;
                        }
                }
 
                public TypeParameterSpec[] TypeParameters {
                        get {
-                               // TODO: Cache this
-                               return CurrentTypeParameters.Select (l => l.Type).ToArray ();
+                               return CurrentTypeParameters.Types;
                        }
                }
 
                public int TypeParametersCount {
                        get {
-                               return CurrentTypeParameters == null ? 0 : CurrentTypeParameters.Length;
+                               return CurrentTypeParameters == null ? 0 : CurrentTypeParameters.Count;
                        }
                }
 
 #endregion
 
+               public override void Accept (StructuralVisitor visitor)
+               {
+                       visitor.Visit (this);
+               }
+
+               public static Method Create (TypeDefinition parent, FullNamedExpression returnType, Modifiers mod,
+                                  MemberName name, ParametersCompiled parameters, Attributes attrs, bool hasConstraints)
+               {
+                       var m = new Method (parent, returnType, mod, name, parameters, attrs);
+
+                       if (hasConstraints && ((mod & Modifiers.OVERRIDE) != 0 || m.IsExplicitImpl)) {
+                               m.Report.Error (460, m.Location,
+                                       "`{0}': Cannot specify constraints for overrides and explicit interface implementation methods",
+                                       m.GetSignatureForError ());
+                       }
+
+                       if ((mod & Modifiers.PARTIAL) != 0) {
+                               const Modifiers invalid_partial_mod = Modifiers.AccessibilityMask | Modifiers.ABSTRACT | Modifiers.EXTERN |
+                                       Modifiers.NEW | Modifiers.OVERRIDE | Modifiers.SEALED | Modifiers.VIRTUAL;
+
+                               if ((mod & invalid_partial_mod) != 0) {
+                                       m.Report.Error (750, m.Location,
+                                               "A partial method cannot define access modifier or any of abstract, extern, new, override, sealed, or virtual modifiers");
+                                       mod &= ~invalid_partial_mod;
+                               }
+
+                               if ((parent.ModFlags & Modifiers.PARTIAL) == 0) {
+                                       m.Report.Error (751, m.Location, 
+                                               "A partial method must be declared within a partial class or partial struct");
+                               }
+                       }
+
+                       if ((mod & Modifiers.STATIC) == 0 && parameters.HasExtensionMethodType) {
+                               m.Report.Error (1105, m.Location, "`{0}': Extension methods must be declared static",
+                                       m.GetSignatureForError ());
+                       }
+
+
+                       return m;
+               }
+
                public override string GetSignatureForError()
                {
                        return base.GetSignatureForError () + parameters.GetSignatureForError ();
@@ -929,9 +939,9 @@ namespace Mono.CSharp {
                public override FullNamedExpression LookupNamespaceOrType (string name, int arity, LookupMode mode, Location loc)
                {
                        if (arity == 0) {
-                               TypeParameter[] tp = CurrentTypeParameters;
+                               var tp = CurrentTypeParameters;
                                if (tp != null) {
-                                       TypeParameter t = TypeParameter.FindTypeParameter (tp, name);
+                                       TypeParameter t = tp.Find (name);
                                        if (t != null)
                                                return new TypeParameterExpr (t, loc);
                                }
@@ -986,6 +996,45 @@ namespace Mono.CSharp {
                        base.ApplyAttributeBuilder (a, ctor, cdata, pa);
                }
 
+               void CreateTypeParameters ()
+               {
+                       var tparams = MemberName.TypeParameters;
+                       string[] snames = new string[MemberName.Arity];
+                       var parent_tparams = Parent.TypeParametersAll;
+
+                       for (int i = 0; i < snames.Length; i++) {
+                               string type_argument_name = tparams[i].MemberName.Name;
+
+                               if (block == null) {
+                                       int idx = parameters.GetParameterIndexByName (type_argument_name);
+                                       if (idx >= 0) {
+                                               var b = block;
+                                               if (b == null)
+                                                       b = new ToplevelBlock (Compiler, Location);
+
+                                               b.Error_AlreadyDeclaredTypeParameter (type_argument_name, parameters[i].Location);
+                                       }
+                               } else {
+                                       INamedBlockVariable variable = null;
+                                       block.GetLocalName (type_argument_name, block, ref variable);
+                                       if (variable != null)
+                                               variable.Block.Error_AlreadyDeclaredTypeParameter (type_argument_name, variable.Location);
+                               }
+
+                               if (parent_tparams != null) {
+                                       var tp = parent_tparams.Find (type_argument_name);
+                                       if (tp != null) {
+                                               tparams[i].WarningParentNameConflict (tp);
+                                       }
+                               }
+
+                               snames[i] = type_argument_name;
+                       }
+
+                       GenericTypeParameterBuilder[] gen_params = MethodBuilder.DefineGenericParameters (snames);
+                       tparams.Define (gen_params, null, 0, Parent);
+               }
+
                protected virtual void DefineTypeParameters ()
                {
                        var tparams = CurrentTypeParameters;
@@ -1028,10 +1077,10 @@ namespace Mono.CSharp {
 
                                                if (base_decl_tparams.Length != 0) {
                                                        base_decl_tparams = base_decl_tparams.Concat (base_tparams).ToArray ();
-                                                       base_targs = base_targs.Concat (tparams.Select<TypeParameter, TypeSpec> (l => l.Type)).ToArray ();
+                                                       base_targs = base_targs.Concat (tparams.Types).ToArray ();
                                                } else {
                                                        base_decl_tparams = base_tparams;
-                                                       base_targs = tparams.Select (l => l.Type).ToArray ();
+                                                       base_targs = tparams.Types;
                                                }
                                        }
                                } else if (MethodData.implementing != null) {
@@ -1048,7 +1097,7 @@ namespace Mono.CSharp {
                                }
                        }
 
-                       for (int i = 0; i < tparams.Length; ++i) {
+                       for (int i = 0; i < tparams.Count; ++i) {
                                var tp = tparams[i];
 
                                if (!tp.ResolveConstraints (this))
@@ -1066,7 +1115,7 @@ namespace Mono.CSharp {
                                        base_tparam.InflateConstraints (inflator, local_tparam);
 
                                        //
-                                       // Check all type argument constraints for possible collision
+                                       // Check all type argument constraints for possible collision or unification
                                        // introduced by inflating inherited constraints in this context
                                        //
                                        // Conflict example:
@@ -1075,31 +1124,67 @@ namespace Mono.CSharp {
                                        // class B : A<int> { override void Foo<U> {} }
                                        //
                                        var local_tparam_targs = local_tparam.TypeArguments;
-                                       if (local_tparam_targs != null) {                                       
+                                       if (local_tparam_targs != null) {
                                                for (int ii = 0; ii < local_tparam_targs.Length; ++ii) {
                                                        var ta = local_tparam_targs [ii];
                                                        if (!ta.IsClass && !ta.IsStruct)
                                                                continue;
 
-                                                       if (Constraints.CheckConflictingInheritedConstraint (local_tparam, ta, this, Location)) {
-                                                               local_tparam.ChangeTypeArgumentToBaseType (ii);
+                                                       TypeSpec[] unique_tparams = null;
+                                                       for (int iii = ii + 1; iii < local_tparam_targs.Length; ++iii) {
+                                                               //
+                                                               // Remove any identical or unified constraint types
+                                                               //
+                                                               var tparam_checked = local_tparam_targs[iii];
+                                                               if (TypeSpecComparer.IsEqual (ta, tparam_checked) || TypeSpec.IsBaseClass (ta, tparam_checked, false)) {
+                                                                       unique_tparams = new TypeSpec[local_tparam_targs.Length - 1];
+                                                                       Array.Copy (local_tparam_targs, 0, unique_tparams, 0, iii);
+                                                                       Array.Copy (local_tparam_targs, iii + 1, unique_tparams, iii, local_tparam_targs.Length - iii - 1);
+                                                               } else if (!TypeSpec.IsBaseClass (tparam_checked, ta, false)) {
+                                                                       Constraints.Error_ConflictingConstraints (this, local_tparam, ta, tparam_checked, Location);
+                                                               }
                                                        }
+
+                                                       if (unique_tparams != null) {
+                                                               local_tparam_targs = unique_tparams;
+                                                               local_tparam.TypeArguments = local_tparam_targs;
+                                                               continue;
+                                                       }
+
+                                                       Constraints.CheckConflictingInheritedConstraint (local_tparam, ta, this, Location);
                                                }
                                        }
 
                                        continue;
                                }
-                               
-                               if (MethodData != null && MethodData.implementing != null) {
-                                       var base_tp = MethodData.implementing.Constraints[i];
-                                       if (!tp.Type.HasSameConstraintsImplementation (base_tp)) {
-                                               Report.SymbolRelatedToPreviousError (MethodData.implementing);
-                                               Report.Error (425, Location,
-                                                       "The constraints for type parameter `{0}' of method `{1}' must match the constraints for type parameter `{2}' of interface method `{3}'. Consider using an explicit interface implementation instead",
-                                                       tp.GetSignatureForError (), GetSignatureForError (), base_tp.GetSignatureForError (), MethodData.implementing.GetSignatureForError ());
-                                       }
+                       }
+
+                       if (base_tparams == null && MethodData != null && MethodData.implementing != null) {
+                               CheckImplementingMethodConstraints (Parent, spec, MethodData.implementing);
+                       }
+               }
+
+               public static bool CheckImplementingMethodConstraints (TypeContainer container, MethodSpec method, MethodSpec baseMethod)
+               {
+                       var tparams = method.Constraints;
+                       var base_tparams = baseMethod.Constraints;
+                       for (int i = 0; i < tparams.Length; ++i) {
+                               if (!tparams[i].HasSameConstraintsImplementation (base_tparams[i])) {
+                                       container.Compiler.Report.SymbolRelatedToPreviousError (method);
+                                       container.Compiler.Report.SymbolRelatedToPreviousError (baseMethod);
+
+                                       // Using container location because the interface can be implemented
+                                       // by base class
+                                       container.Compiler.Report.Error (425, container.Location,
+                                               "The constraints for type parameter `{0}' of method `{1}' must match the constraints for type parameter `{2}' of interface method `{3}'. Consider using an explicit interface implementation instead",
+                                               tparams[i].GetSignatureForError (), method.GetSignatureForError (),
+                                               base_tparams[i].GetSignatureForError (), baseMethod.GetSignatureForError ());
+                                       return false;
                                }
                        }
+
+                       return true;
                }
 
                //
@@ -1124,10 +1209,10 @@ namespace Mono.CSharp {
                        }
 
                        if (CurrentTypeParameters == null) {
-                               if (base_method != null) {
-                                       if (parameters.Count == 1 && ParameterTypes[0].BuiltinType == BuiltinTypeSpec.Type.Object && Name == "Equals")
+                               if (base_method != null && !IsExplicitImpl) {
+                                       if (parameters.Count == 1 && ParameterTypes[0].BuiltinType == BuiltinTypeSpec.Type.Object && MemberName.Name == "Equals")
                                                Parent.PartialContainer.Mark_HasEquals ();
-                                       else if (parameters.IsEmpty && Name == "GetHashCode")
+                                       else if (parameters.IsEmpty && MemberName.Name == "GetHashCode")
                                                Parent.PartialContainer.Mark_HasGetHashCode ();
                                }
                                        
@@ -1146,6 +1231,12 @@ namespace Mono.CSharp {
                                }
 
                                if ((ModFlags & Modifiers.ASYNC) != 0) {
+                                       if (ReturnType.Kind != MemberKind.Void &&
+                                               ReturnType != Module.PredefinedTypes.Task.TypeSpec &&
+                                               !ReturnType.IsGenericTask) {
+                                               Report.Error (1983, Location, "The return type of an async method must be void, Task, or Task<T>");
+                                       }
+
                                        AsyncInitializer.Create (this, block, parameters, Parent.PartialContainer, ReturnType, Location);
                                }
                        }
@@ -1154,7 +1245,7 @@ namespace Mono.CSharp {
                                return true;
 
                        if (parameters.HasExtensionMethodType) {
-                               if (Parent.PartialContainer.IsStatic && !Parent.IsGeneric) {
+                               if (Parent.PartialContainer.IsStatic && !Parent.IsGenericOrParentIsGeneric) {
                                        if (!Parent.IsTopLevel)
                                                Report.Error (1109, Location, "`{0}': Extension methods cannot be defined in a nested class",
                                                        GetSignatureForError ());
@@ -1162,7 +1253,7 @@ namespace Mono.CSharp {
                                        PredefinedAttribute pa = Module.PredefinedAttributes.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",
+                                                       "`{0}': Extension methods require `System.Runtime.CompilerServices.ExtensionAttribute' type to be available. Are you missing an assembly reference?",
                                                        GetSignatureForError ());
                                        }
 
@@ -1180,12 +1271,15 @@ namespace Mono.CSharp {
                        // This is used to track the Entry Point,
                        //
                        var settings = Compiler.Settings;
-                       if (settings.NeedsEntryPoint && Name == "Main" && (settings.MainClass == null || settings.MainClass == Parent.TypeBuilder.FullName)) {
+                       if (settings.NeedsEntryPoint && MemberName.Name == "Main" && (settings.MainClass == null || settings.MainClass == Parent.TypeBuilder.FullName)) {
                                if (IsEntryPoint ()) {
                                        if (Parent.DeclaringAssembly.EntryPoint == null) {
-                                               if (Parent.IsGeneric || MemberName.IsGeneric) {
+                                               if (Parent.IsGenericOrParentIsGeneric || MemberName.IsGeneric) {
                                                        Report.Warning (402, 4, Location, "`{0}': an entry point cannot be generic or in a generic type",
                                                                GetSignatureForError ());
+                                               } else if ((ModFlags & Modifiers.ASYNC) != 0) {
+                                                       Report.Error (4009, Location, "`{0}': an entry point cannot be async method",
+                                                               GetSignatureForError ());
                                                } else {
                                                        SetIsUsed ();
                                                        Parent.DeclaringAssembly.EntryPoint = this;
@@ -1226,7 +1320,7 @@ namespace Mono.CSharp {
                                }
 
                                if (CurrentTypeParameters != null) {
-                                       for (int i = 0; i < CurrentTypeParameters.Length; ++i) {
+                                       for (int i = 0; i < CurrentTypeParameters.Count; ++i) {
                                                var tp = CurrentTypeParameters [i];
                                                tp.CheckGenericConstraints (false);
                                                tp.Emit ();
@@ -1246,10 +1340,6 @@ namespace Mono.CSharp {
 
                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;
 
@@ -1263,10 +1353,9 @@ namespace Mono.CSharp {
 
                protected override bool ResolveMemberType ()
                {
-                       if (GenericMethod != null) {
+                       if (CurrentTypeParameters != null) {
                                MethodBuilder = Parent.TypeBuilder.DefineMethod (GetFullName (MemberName), flags);
-                               if (!GenericMethod.Define (this))
-                                       return false;
+                               CreateTypeParameters ();
                        }
 
                        return base.ResolveMemberType ();
@@ -1374,7 +1463,7 @@ namespace Mono.CSharp {
                                ec.Report.Error (516, loc, "Constructor `{0}' cannot call itself",
                                        caller_builder.GetSignatureForError ());
                        }
-                                               
+
                        return this;
                }
 
@@ -1384,8 +1473,6 @@ namespace Mono.CSharp {
                        if (base_ctor == null)
                                return;
                        
-                       ec.Mark (loc);
-
                        var call = new CallEmitter ();
                        call.InstanceExpression = new CompilerGeneratedThis (type, loc); 
                        call.EmitPredefined (ec, base_ctor, argument_list);
@@ -1441,20 +1528,15 @@ namespace Mono.CSharp {
                public static readonly string ConstructorName = ".ctor";
                public static readonly string TypeConstructorName = ".cctor";
 
-               //
-               // The spec claims that static is not permitted, but
-               // my very own code has static constructors.
-               //
-               public Constructor (DeclSpace parent, string name, Modifiers mod, Attributes attrs, ParametersCompiled args,
-                                   ConstructorInitializer init, Location loc)
-                       : base (parent, null, null, mod, AllowedModifiers,
-                               new MemberName (name, loc), attrs, args)
+               public Constructor (TypeDefinition parent, string name, Modifiers mod, Attributes attrs, ParametersCompiled args, Location loc)
+                       : base (parent, null, mod, AllowedModifiers, new MemberName (name, loc), attrs, args)
                {
-                       Initializer = init;
                }
 
                public bool HasCompliantArgs {
-                       get { return has_compliant_args; }
+                       get {
+                               return has_compliant_args;
+                       }
                }
 
                public override AttributeTargets AttributeTargets {
@@ -1482,6 +1564,11 @@ namespace Mono.CSharp {
                                        (Initializer.Arguments == null);
                }
 
+               public override void Accept (StructuralVisitor visitor)
+               {
+                       visitor.Visit (this);
+               }
+
                public override void ApplyAttributeBuilder (Attribute a, MethodSpec ctor, byte[] cdata, PredefinedAttributes pa)
                {
                        if (a.IsValidSecurityAttribute ()) {
@@ -1505,6 +1592,9 @@ namespace Mono.CSharp {
                                        return false;
                                }
 
+                               if ((caching_flags & Flags.MethodOverloadsExist) != 0)
+                                       Parent.MemberCache.CheckExistingMembersOverloads (this, parameters);
+
                                // the rest can be ignored
                                return true;
                        }
@@ -1535,14 +1625,6 @@ namespace Mono.CSharp {
                        if (ConstructorBuilder != null)
                                return true;
 
-                       var ca = MethodAttributes.RTSpecialName | MethodAttributes.SpecialName;
-                       
-                       if ((ModFlags & Modifiers.STATIC) != 0) {
-                               ca |= MethodAttributes.Static | MethodAttributes.Private;
-                       } else {
-                               ca |= ModifiersExtensions.MethodAttr (ModFlags);
-                       }
-
                        if (!CheckAbstractAndExtern (block != null))
                                return false;
                        
@@ -1550,6 +1632,8 @@ namespace Mono.CSharp {
                        if (!CheckBase ())
                                return false;
 
+                       var ca = ModifiersExtensions.MethodAttr (ModFlags) | MethodAttributes.RTSpecialName | MethodAttributes.SpecialName;
+
                        ConstructorBuilder = Parent.TypeBuilder.DefineConstructor (
                                ca, CallingConventions,
                                parameters.GetMetaInfo ());
@@ -1593,50 +1677,56 @@ namespace Mono.CSharp {
                        base.Emit ();
                        parameters.ApplyAttributes (this, ConstructorBuilder);
 
-                       //
-                       // 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);
 
                        BlockContext bc = new BlockContext (this, block, Compiler.BuiltinTypes.Void);
                        bc.Set (ResolveContext.Options.ConstructorScope);
 
-                       if (emit_field_initializers)
+                       //
+                       // If we use a "this (...)" constructor initializer, then
+                       // do not emit field initializers, they are initialized in the other constructor
+                       //
+                       if (!(Initializer is ConstructorThisInitializer))
                                Parent.PartialContainer.ResolveFieldInitializers (bc);
 
                        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 == MemberKind.Struct) &&
-                                       ((ModFlags & Modifiers.STATIC) == 0) && (Initializer == null))
-                                       block.AddThisVariable (bc, Parent, Location);
-
-                               if (block != null && (ModFlags & Modifiers.STATIC) == 0){
-                                       if (Parent.PartialContainer.Kind == MemberKind.Class && Initializer == null)
-                                               Initializer = new GeneratedBaseInitializer (Location);
+                               if (!IsStatic) {
+                                       if (Initializer == null) {
+                                               if (Parent.PartialContainer.Kind == MemberKind.Struct) {
+                                                       //
+                                                       // If this is a non-static `struct' constructor and doesn't have any
+                                                       // initializer, it must initialize all of the struct's fields.
+                                                       //
+                                                       block.AddThisVariable (bc);
+                                               } else if (Parent.PartialContainer.Kind == MemberKind.Class) {
+                                                       Initializer = new GeneratedBaseInitializer (Location);
+                                               }
+                                       }
 
                                        if (Initializer != null) {
-                                               block.AddScopeStatement (new StatementExpression (Initializer));
+                                               //
+                                               // Use location of the constructor to emit sequence point of initializers
+                                               // at beginning of constructor name
+                                               //
+                                               // TODO: Need to extend mdb to support line regions to allow set a breakpoint at
+                                               // initializer
+                                               //
+                                               block.AddScopeStatement (new StatementExpression (Initializer, Location));
                                        }
                                }
-                       }
 
-                       SourceMethod source = SourceMethod.Create (Parent, ConstructorBuilder, block);
-
-                       if (block != null) {
                                if (block.Resolve (null, bc, this)) {
                                        EmitContext ec = new EmitContext (this, ConstructorBuilder.GetILGenerator (), bc.ReturnType);
                                        ec.With (EmitContext.Options.ConstructorScope, true);
 
+                                       SourceMethod source = SourceMethod.Create (Parent, ConstructorBuilder);
+
                                        block.Emit (ec);
+
+                                       if (source != null)
+                                               source.CloseMethod ();
                                }
                        }
 
-                       if (source != null)
-                               source.CloseMethod ();
-
                        if (declarative_security != null) {
                                foreach (var de in declarative_security) {
 #if STATIC
@@ -1715,15 +1805,6 @@ namespace Mono.CSharp {
                        return false;
                }
 
-               GenericMethod IMethodData.GenericMethod {
-                       get {
-                               return null;
-                       }
-               }
-
-               void IMethodData.EmitExtraSymbolInfo (SourceMethod source)
-               { }
-
                #endregion
        }
 
@@ -1736,7 +1817,6 @@ namespace Mono.CSharp {
                Location Location { get; }
                MemberName MethodName { get; }
                TypeSpec ReturnType { get; }
-               GenericMethod GenericMethod { get; }
                ParametersCompiled ParameterInfo { get; }
                MethodSpec Spec { get; }
                bool IsAccessor { get; }
@@ -1745,7 +1825,6 @@ namespace Mono.CSharp {
                ToplevelBlock Block { get; set; }
 
                EmitContext CreateEmitContext (ILGenerator ig);
-               void EmitExtraSymbolInfo (SourceMethod source);
        }
 
        //
@@ -1759,8 +1838,6 @@ namespace Mono.CSharp {
 
                public readonly IMethodData method;
 
-               public readonly GenericMethod GenericMethod;
-
                //
                // Are we implementing an interface ?
                //
@@ -1801,40 +1878,41 @@ namespace Mono.CSharp {
                public MethodData (InterfaceMemberBase member,
                                   Modifiers modifiers, MethodAttributes flags, 
                                   IMethodData method, MethodBuilder builder,
-                                  GenericMethod generic, MethodSpec parent_method)
+                                  MethodSpec 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, Report Report)
+               public bool Define (TypeDefinition container, string method_full_name)
                {
-                       TypeContainer container = parent.PartialContainer;
-
                        PendingImplementation pending = container.PendingImplementations;
                        MethodSpec ambig_iface_method;
+                       bool optional = false;
+
                        if (pending != null) {
-                               implementing = pending.IsInterfaceMethod (method.MethodName, member.InterfaceType, this, out ambig_iface_method);
+                               implementing = pending.IsInterfaceMethod (method.MethodName, member.InterfaceType, this, out ambig_iface_method, ref optional);
 
                                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}'",
+                                                       container.Compiler.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,
+                                                       container.Compiler.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.IsAccessor && !method.IsAccessor) {
-                                               Report.SymbolRelatedToPreviousError (implementing);
-                                               Report.Error (683, method.Location, "`{0}' explicit method implementation cannot implement `{1}' because it is an accessor",
+                                               container.Compiler.Report.SymbolRelatedToPreviousError (implementing);
+                                               container.Compiler.Report.Error (683, method.Location,
+                                                       "`{0}' explicit method implementation cannot implement `{1}' because it is an accessor",
                                                        member.GetSignatureForError (), TypeManager.CSharpSignature (implementing));
                                                return false;
                                        }
@@ -1842,20 +1920,23 @@ namespace Mono.CSharp {
                                        if (implementing != null) {
                                                if (!method.IsAccessor) {
                                                        if (implementing.IsAccessor) {
-                                                               Report.SymbolRelatedToPreviousError (implementing);
-                                                               Report.Error (470, method.Location, "Method `{0}' cannot implement interface accessor `{1}'",
+                                                               container.Compiler.Report.SymbolRelatedToPreviousError (implementing);
+                                                               container.Compiler.Report.Error (470, method.Location,
+                                                                       "Method `{0}' cannot implement interface accessor `{1}'",
                                                                        method.GetSignatureForError (), TypeManager.CSharpSignature (implementing));
                                                        }
                                                } else if (implementing.DeclaringType.IsInterface) {
                                                        if (!implementing.IsAccessor) {
-                                                               Report.SymbolRelatedToPreviousError (implementing);
-                                                               Report.Error (686, method.Location, "Accessor `{0}' cannot implement interface member `{1}' for type `{2}'. Use an explicit interface implementation",
+                                                               container.Compiler.Report.SymbolRelatedToPreviousError (implementing);
+                                                               container.Compiler.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 ());
                                                        } else {
                                                                PropertyBase.PropertyMethod pm = 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}'",
+                                                                       container.Compiler.Report.SymbolRelatedToPreviousError (implementing);
+                                                                       container.Compiler.Report.Error (277, method.Location,
+                                                                               "Accessor `{0}' must be declared public to implement interface member `{1}'",
                                                                                method.GetSignatureForError (), implementing.GetSignatureForError ());
                                                                }
                                                        }
@@ -1871,43 +1952,44 @@ namespace Mono.CSharp {
                        // 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 (member.IsExplicitImpl) {
                                        if (method.ParameterInfo.HasParams && !implementing.Parameters.HasParams) {
-                                               Report.SymbolRelatedToPreviousError (implementing);
-                                               Report.Error (466, method.Location, "`{0}': the explicit interface implementation cannot introduce the params modifier",
+                                               container.Compiler.Report.SymbolRelatedToPreviousError (implementing);
+                                               container.Compiler.Report.Error (466, method.Location,
+                                                       "`{0}': the explicit interface implementation cannot introduce the params modifier",
                                                        method.GetSignatureForError ());
                                        }
 
                                        if (ambig_iface_method != null) {
-                                               Report.SymbolRelatedToPreviousError (ambig_iface_method);
-                                               Report.SymbolRelatedToPreviousError (implementing);
-                                               Report.Warning (473, 2, method.Location,
+                                               container.Compiler.Report.SymbolRelatedToPreviousError (ambig_iface_method);
+                                               container.Compiler.Report.SymbolRelatedToPreviousError (implementing);
+                                               container.Compiler.Report.Warning (473, 2, method.Location,
                                                        "Explicit interface implementation `{0}' matches more than one interface member. Consider using a non-explicit implementation instead",
                                                        method.GetSignatureForError ());
                                        }
-
                                } else {
+                                       //
+                                       // Setting implementin to null inside this block will trigger a more
+                                       // verbose error reporting for missing interface implementations
+                                       //
                                        if (implementing.DeclaringType.IsInterface) {
                                                //
                                                // If this is an interface method implementation,
                                                // check for public accessibility
                                                //
-                                               if ((flags & MethodAttributes.MemberAccessMask) != MethodAttributes.Public)
-                                               {
+                                               if ((flags & MethodAttributes.MemberAccessMask) != MethodAttributes.Public) {
+                                                       implementing = null;
+                                               } else if (optional && (container.Interfaces == null || Array.IndexOf (container.Interfaces, implementing.DeclaringType) < 0)) {
+                                                       //
+                                                       // We are not implementing interface when base class already implemented it
+                                                       //
                                                        implementing = null;
                                                }
-                                       } else if ((flags & MethodAttributes.MemberAccessMask) == MethodAttributes.Private){
+                                       } else if ((flags & MethodAttributes.MemberAccessMask) == MethodAttributes.Private) {
                                                // We may never be private.
                                                implementing = null;
 
-                                       } else if ((modifiers & Modifiers.OVERRIDE) == 0){
+                                       } else if ((modifiers & Modifiers.OVERRIDE) == 0) {
                                                //
                                                // We may be protected if we're overriding something.
                                                //
@@ -1931,9 +2013,8 @@ namespace Mono.CSharp {
                                // When implementing interface methods, set NewSlot
                                // unless, we are overwriting a method.
                                //
-                               if (implementing.DeclaringType.IsInterface){
-                                       if ((modifiers & Modifiers.OVERRIDE) == 0)
-                                               flags |= MethodAttributes.NewSlot;
+                               if ((modifiers & Modifiers.OVERRIDE) == 0 && implementing.DeclaringType.IsInterface) {
+                                       flags |= MethodAttributes.NewSlot;
                                }
 
                                flags |= MethodAttributes.Virtual | MethodAttributes.HideBySig;
@@ -1945,8 +2026,8 @@ namespace Mono.CSharp {
                                //
                                // clear the pending implementation flag (requires explicit methods to be defined first)
                                //
-                               parent.PartialContainer.PendingImplementations.ImplementMethod (method.MethodName,
-                                       member.InterfaceType, this, member.IsExplicitImpl, out ambig_iface_method);
+                               pending.ImplementMethod (method.MethodName,
+                                       member.InterfaceType, this, member.IsExplicitImpl, out ambig_iface_method, ref optional);
 
                                //
                                // Update indexer accessor name to match implementing abstract accessor
@@ -1976,7 +2057,7 @@ namespace Mono.CSharp {
                /// <summary>
                /// Create the MethodBuilder for the method 
                /// </summary>
-               void DefineMethodBuilder (TypeContainer container, string method_name, ParametersCompiled param)
+               void DefineMethodBuilder (TypeDefinition container, string method_name, ParametersCompiled param)
                {
                        var return_type = method.ReturnType.GetMetaInfo ();
                        var p_types = param.GetMetaInfo ();
@@ -2012,30 +2093,25 @@ namespace Mono.CSharp {
                //
                // Emits the code
                // 
-               public void Emit (DeclSpace parent)
+               public void Emit (TypeDefinition parent)
                {
-                       if (GenericMethod != null)
-                               GenericMethod.EmitAttributes ();
-
                        var mc = (IMemberContext) method;
 
                        method.ParameterInfo.ApplyAttributes (mc, MethodBuilder);
 
-                       SourceMethod source = SourceMethod.Create (parent, MethodBuilder, method.Block);
-
                        ToplevelBlock block = method.Block;
                        if (block != null) {
                                BlockContext bc = new BlockContext (mc, block, method.ReturnType);
                                if (block.Resolve (null, bc, method)) {
                                        EmitContext ec = method.CreateEmitContext (MethodBuilder.GetILGenerator ());
 
+                                       SourceMethod source = SourceMethod.Create (parent, MethodBuilder);
+
                                        block.Emit (ec);
-                               }
-                       }
 
-                       if (source != null) {
-                               method.EmitExtraSymbolInfo (source);
-                               source.CloseMethod ();
+                                       if (source != null)
+                                               source.CloseMethod ();
+                               }
                        }
                }
        }
@@ -2050,14 +2126,18 @@ namespace Mono.CSharp {
 
                public static readonly string MetadataName = "Finalize";
 
-               public Destructor (DeclSpace parent, Modifiers mod, ParametersCompiled parameters, Attributes attrs, Location l)
-                       : base (parent, null, null, mod, AllowedModifiers,
-                               new MemberName (MetadataName, l), attrs, parameters)
+               public Destructor (TypeDefinition parent, Modifiers mod, ParametersCompiled parameters, Attributes attrs, Location l)
+                       : base (parent, null, mod, AllowedModifiers, new MemberName (MetadataName, l), attrs, parameters)
                {
                        ModFlags &= ~Modifiers.PRIVATE;
                        ModFlags |= Modifiers.PROTECTED | Modifiers.OVERRIDE;
                }
 
+               public override void Accept (StructuralVisitor visitor)
+               {
+                       visitor.Visit (this);
+               }
+
                public override void ApplyAttributeBuilder (Attribute a, MethodSpec ctor, byte[] cdata, PredefinedAttributes pa)
                {
                        if (a.Type == pa.Conditional) {
@@ -2087,15 +2167,19 @@ namespace Mono.CSharp {
                                MethodGroupExpr method_expr = MethodGroupExpr.CreatePredefined (base_dtor, base_type, Location);
                                method_expr.InstanceExpression = new BaseThis (base_type, Location);
 
-                               var try_block = new ExplicitBlock (block, block.StartLocation, block.EndLocation);
-                               var finaly_block = new ExplicitBlock (block, Location, Location);
+                               var try_block = new ExplicitBlock (block, block.StartLocation, block.EndLocation) {
+                                       IsCompilerGenerated = true
+                               };
+                               var finaly_block = new ExplicitBlock (block, Location, Location) {
+                                       IsCompilerGenerated = true
+                               };
 
                                //
                                // 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))));
+                               finaly_block.AddStatement (new StatementExpression (new Invocation (method_expr, new Arguments (0)), Location.Null));
 
                                var tf = new TryFinally (try_block, finaly_block, Location);
                                block.WrapIntoDestructor (tf, try_block);
@@ -2141,7 +2225,7 @@ namespace Mono.CSharp {
 
                static MemberName SetupName (string prefix, InterfaceMemberBase member, Location loc)
                {
-                       return new MemberName (member.MemberName.Left, prefix + member.ShortName, loc);
+                       return new MemberName (member.MemberName.Left, prefix + member.ShortName, member.MemberName.ExplicitInterface, loc);
                }
 
                public void UpdateName (InterfaceMemberBase member)
@@ -2183,12 +2267,6 @@ namespace Mono.CSharp {
                        return false;
                }
 
-               GenericMethod IMethodData.GenericMethod {
-                       get {
-                               return null;
-                       }
-               }
-
                public MemberName MethodName {
                        get {
                                return MemberName;
@@ -2247,7 +2325,7 @@ namespace Mono.CSharp {
                        throw new NotSupportedException ();
                }
 
-               public virtual void Emit (DeclSpace parent)
+               public virtual void Emit (TypeDefinition parent)
                {
                        method_data.Emit (parent);
 
@@ -2314,9 +2392,6 @@ namespace Mono.CSharp {
                public override string DocCommentHeader {
                        get { throw new InvalidOperationException ("Unexpected attempt to get doc comment from " + this.GetType () + "."); }
                }
-
-               void IMethodData.EmitExtraSymbolInfo (SourceMethod source)
-               { }
        }
 
        public class Operator : MethodOrOperator {
@@ -2402,17 +2477,20 @@ namespace Mono.CSharp {
                        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,
-                                Modifiers mod_flags, ParametersCompiled parameters,
+
+               public Operator (TypeDefinition parent, OpType type, FullNamedExpression ret_type, Modifiers 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)
+                       : base (parent, ret_type, mod_flags, AllowedModifiers, new MemberName (GetMetadataName (type), loc), attrs, parameters)
                {
                        OperatorType = type;
                        Block = block;
                }
 
+               public override void Accept (StructuralVisitor visitor)
+               {
+                       visitor.Visit (this);
+               }
+
                public override void ApplyAttributeBuilder (Attribute a, MethodSpec ctor, byte[] cdata, PredefinedAttributes pa)
                {
                        if (a.Type == pa.Conditional) {