entry for a change in HttpResponseStream.cs
[mono.git] / mcs / mcs / parameter.cs
index 6b9eae38da3c5f07c52e9068efbe8895d56745e2..26aa628a1ee1812b811fd775a57a5b638476a045 100644 (file)
@@ -13,7 +13,6 @@
 using System;
 using System.Reflection;
 using System.Reflection.Emit;
-using System.Collections;
 using System.Text;
 
 namespace Mono.CSharp {
@@ -21,19 +20,14 @@ namespace Mono.CSharp {
        /// <summary>
        ///   Abstract Base class for parameters of a method.
        /// </summary>
-       public abstract class ParameterBase : Attributable {
-
+       public abstract class ParameterBase : Attributable
+       {
                protected ParameterBuilder builder;
 
-               protected ParameterBase (Attributes attrs)
-                       : base (attrs)
+               public override void ApplyAttributeBuilder (Attribute a, CustomAttributeBuilder cb, PredefinedAttributes pa)
                {
-               }
-
-               public override void ApplyAttributeBuilder (Attribute a, CustomAttributeBuilder cb)
-               {
-#if !NET_2_0
-                       if (a.Type == TypeManager.marshal_as_attr_type) {
+#if false
+                       if (a.Type == pa.MarshalAs) {
                                UnmanagedMarshal marshal = a.GetMarshal (this);
                                if (marshal != null) {
                                        builder.SetMarshal (marshal);
@@ -46,9 +40,20 @@ namespace Mono.CSharp {
                                return;
                        }
 
+                       if (a.Type == pa.Dynamic) {
+                               a.Error_MisusedDynamicAttribute ();
+                               return;
+                       }
+
                        builder.SetCustomAttribute (cb);
                }
 
+               public ParameterBuilder Builder {
+                       get {
+                               return builder;
+                       }
+               }
+
                public override bool IsClsComplianceRequired()
                {
                        return false;
@@ -58,29 +63,34 @@ namespace Mono.CSharp {
        /// <summary>
        /// Class for applying custom attributes on the return type
        /// </summary>
-       public class ReturnParameter : ParameterBase {
-               public ReturnParameter (MethodBuilder mb, Location location):
-                       base (null)
+       public class ReturnParameter : ParameterBase
+       {
+               MemberCore method;
+
+               // TODO: merge method and mb
+               public ReturnParameter (MemberCore method, MethodBuilder mb, Location location)
                {
+                       this.method = method;
                        try {
                                builder = mb.DefineParameter (0, ParameterAttributes.None, "");                 
                        }
                        catch (ArgumentOutOfRangeException) {
-                               Report.RuntimeMissingSupport (location, "custom attributes on the return type");
+                               method.Compiler.Report.RuntimeMissingSupport (location, "custom attributes on the return type");
                        }
                }
 
-               public override void ApplyAttributeBuilder(Attribute a, CustomAttributeBuilder cb)
+               public override void ApplyAttributeBuilder (Attribute a, CustomAttributeBuilder cb, PredefinedAttributes pa)
                {
-                       if (a.Type == TypeManager.cls_compliant_attribute_type) {
-                               Report.Warning (3023, 1, a.Location, "CLSCompliant attribute has no meaning when applied to return types. Try putting it on the method instead");
+                       if (a.Type == pa.CLSCompliant) {
+                               method.Compiler.Report.Warning (3023, 1, a.Location,
+                                       "CLSCompliant attribute has no meaning when applied to return types. Try putting it on the method instead");
                        }
 
                        // This occurs after Warning -28
                        if (builder == null)
                                return;
 
-                       base.ApplyAttributeBuilder (a, cb);
+                       base.ApplyAttributeBuilder (a, cb, pa);
                }
 
                public override AttributeTargets AttributeTargets {
@@ -89,12 +99,6 @@ namespace Mono.CSharp {
                        }
                }
 
-               public override IResolveContext ResolveContext {
-                       get {
-                               throw new NotSupportedException ();
-                       }
-               }
-
                /// <summary>
                /// Is never called
                /// </summary>
@@ -112,10 +116,9 @@ namespace Mono.CSharp {
        /// 
        // TODO: should use more code from Parameter.ApplyAttributeBuilder
        public class ImplicitParameter : ParameterBase {
-               public ImplicitParameter (MethodBuilder mb):
-                       base (null)
+               public ImplicitParameter (MethodBuilder mb)
                {
-                       builder = mb.DefineParameter (1, ParameterAttributes.None, "");                 
+                       builder = mb.DefineParameter (1, ParameterAttributes.None, "value");                    
                }
 
                public override AttributeTargets AttributeTargets {
@@ -124,12 +127,6 @@ namespace Mono.CSharp {
                        }
                }
 
-               public override IResolveContext ResolveContext {
-                       get {
-                               throw new NotSupportedException ();
-                       }
-               }
-
                /// <summary>
                /// Is never called
                /// </summary>
@@ -147,7 +144,7 @@ namespace Mono.CSharp {
                {
                }
 
-               public override Type Resolve (IResolveContext ec)
+               public override Type Resolve (IMemberContext ec)
                {
                        if (parameter_type == null)
                                throw new InternalErrorException ("A type of implicit lambda parameter `{0}' is not set",
@@ -167,13 +164,13 @@ namespace Mono.CSharp {
                {
                }
 
-               public override Type Resolve (IResolveContext ec)
+               public override Type Resolve (IMemberContext ec)
                {
                        if (base.Resolve (ec) == null)
                                return null;
 
                        if (!parameter_type.IsArray || parameter_type.GetArrayRank () != 1) {
-                               Report.Error (225, Location, "The params parameter must be a single dimensional array");
+                               ec.Compiler.Report.Error (225, Location, "The params parameter must be a single dimensional array");
                                return null;
                        }
 
@@ -183,28 +180,14 @@ namespace Mono.CSharp {
                public override void ApplyAttributes (MethodBuilder mb, ConstructorBuilder cb, int index)
                {
                        base.ApplyAttributes (mb, cb, index);
-
-                       CustomAttributeBuilder ca = TypeManager.param_array_attr;
-                       if (ca == null) {
-                               ConstructorInfo ci = TypeManager.GetPredefinedConstructor (TypeManager.param_array_type, Location, Type.EmptyTypes);
-                               if (ci == null)
-                                       return;
-
-                               ca = new CustomAttributeBuilder (ci, new object [0]);
-                               if (ca == null)
-                                       return;
-
-                               TypeManager.param_array_attr = ca;
-                       }
-                               
-                       builder.SetCustomAttribute (ca);
+                       PredefinedAttributes.Get.ParamArray.EmitAttribute (builder);
                }
        }
 
        public class ArglistParameter : Parameter {
                // Doesn't have proper type because it's never chosen for better conversion
                public ArglistParameter (Location loc) :
-                       base (null, String.Empty, Parameter.Modifier.ARGLIST, null, loc)
+                       base (null, String.Empty, Parameter.Modifier.NONE, null, loc)
                {
                }
 
@@ -218,9 +201,9 @@ namespace Mono.CSharp {
                        return true;
                }
 
-               public override Type Resolve (IResolveContext ec)
+               public override Type Resolve (IMemberContext ec)
                {
-                       return typeof (ArglistParameter);
+                       return InternalType.Arglist;
                }
 
                public override string GetSignatureForError ()
@@ -231,7 +214,9 @@ namespace Mono.CSharp {
 
        public interface IParameterData
        {
+               Expression DefaultValue { get; }
                bool HasExtensionMethodModifier { get; }
+               bool HasDefaultValue { get; }
                Parameter.Modifier ModFlags { get; }
                string Name { get; }
        }
@@ -248,7 +233,6 @@ namespace Mono.CSharp {
                        PARAMS  = 4,
                        // This is a flag which says that it's either REF or OUT.
                        ISBYREF = 8,
-                       ARGLIST = 16,
                        REFMASK = 32,
                        OUTMASK = 64,
                        This    = 128
@@ -259,54 +243,59 @@ namespace Mono.CSharp {
                protected FullNamedExpression TypeName;
                readonly Modifier modFlags;
                string name;
+               Expression default_expr;
                protected Type parameter_type;
                public readonly Location Location;
                int idx;
                public bool HasAddressTaken;
 
-               IResolveContext resolve_context;
-               LocalVariableReference expr_tree_variable;
+               Expression expr_tree_variable;
                static TypeExpr parameter_expr_tree_type;
 
-               public HoistedVariable HoistedVariableReference;
+               HoistedVariable hoisted_variant;
 
                public Parameter (FullNamedExpression type, string name, Modifier mod, Attributes attrs, Location loc)
-                       : base (attrs)
                {
-                       if (type == TypeManager.system_void_expr)
-                               Report.Error (1536, loc, "Invalid parameter type `void'");
-
                        this.name = name;
                        modFlags = mod;
                        Location = loc;
                        TypeName = type;
+
+                       // Only assign, attributes will be attached during resolve
+                       base.attributes = attrs;
                }
 
-               public override void ApplyAttributeBuilder (Attribute a, CustomAttributeBuilder cb)
+               public override void ApplyAttributeBuilder (Attribute a, CustomAttributeBuilder cb, PredefinedAttributes pa)
                {
-                       if (a.Type == TypeManager.in_attribute_type && ModFlags == Modifier.OUT) {
-                               Report.Error (36, a.Location, "An out parameter cannot have the `In' attribute");
+                       if (a.Type == pa.In && ModFlags == Modifier.OUT) {
+                               a.Report.Error (36, a.Location, "An out parameter cannot have the `In' attribute");
                                return;
                        }
 
-                       if (a.Type == TypeManager.param_array_type) {
-                               Report.Error (674, a.Location, "Do not use `System.ParamArrayAttribute'. Use the `params' keyword instead");
+                       if (a.Type == pa.ParamArray) {
+                               a.Report.Error (674, a.Location, "Do not use `System.ParamArrayAttribute'. Use the `params' keyword instead");
                                return;
                        }
 
-                       if (a.Type == TypeManager.out_attribute_type && (ModFlags & Modifier.REF) == Modifier.REF &&
-                           TypeManager.in_attribute_type != null && !OptAttributes.Contains (TypeManager.in_attribute_type)) {
-                               Report.Error (662, a.Location,
+                       if (a.Type == PredefinedAttributes.Get.Out && (ModFlags & Modifier.REF) == Modifier.REF &&
+                           !OptAttributes.Contains (pa.In)) {
+                               a.Report.Error (662, a.Location,
                                        "Cannot specify only `Out' attribute on a ref parameter. Use both `In' and `Out' attributes or neither");
                                return;
                        }
 
-                       if (a.Type == TypeManager.cls_compliant_attribute_type) {
-                               Report.Warning (3022, 1, a.Location, "CLSCompliant attribute has no meaning when applied to parameters. Try putting it on the method instead");
+                       if (a.Type == pa.CLSCompliant) {
+                               a.Report.Warning (3022, 1, a.Location, "CLSCompliant attribute has no meaning when applied to parameters. Try putting it on the method instead");
                        }
 
-                       // TypeManager.default_parameter_value_attribute_type is null if !NET_2_0, or if System.dll is not referenced
-                       if (a.Type == TypeManager.default_parameter_value_attribute_type) {
+                       if (HasDefaultValue && (a.Type == pa.DefaultParameterValue || a.Type == pa.OptionalParameter)) {
+                               a.Report.Error (1745, a.Location,
+                                       "Cannot specify `{0}' attribute on optional parameter `{1}'",
+                                       TypeManager.CSharpName (a.Type).Replace ("Attribute", ""), Name);
+                               return;
+                       }
+
+                       if (a.Type == pa.DefaultParameterValue) {
                                object val = a.GetParameterDefaultValue ();
                                if (val != null) {
                                        Type t = val.GetType ();
@@ -315,10 +304,10 @@ namespace Mono.CSharp {
                                                        if (!t.IsArray)
                                                                t = TypeManager.type_type;
 
-                                                       Report.Error (1910, a.Location, "Argument of type `{0}' is not applicable for the DefaultValue attribute",
+                                                       a.Report.Error (1910, a.Location, "Argument of type `{0}' is not applicable for the DefaultParameterValue attribute",
                                                                TypeManager.CSharpName (t));
                                                } else {
-                                                       Report.Error (1909, a.Location, "The DefaultValue attribute is not applicable on parameters of type `{0}'",
+                                                       a.Report.Error (1909, a.Location, "The DefaultParameterValue attribute is not applicable on parameters of type `{0}'",
                                                                TypeManager.CSharpName (parameter_type)); ;
                                                }
                                                return;
@@ -326,15 +315,15 @@ namespace Mono.CSharp {
                                }
 
                                if (parameter_type == TypeManager.object_type ||
-                                   (val == null && !TypeManager.IsValueType (parameter_type)) ||
+                                   (val == null && !TypeManager.IsGenericParameter (parameter_type) && TypeManager.IsReferenceType (parameter_type)) ||
                                    (val != null && TypeManager.TypeToCoreType (val.GetType ()) == parameter_type))
                                        builder.SetConstant (val);
                                else
-                                       Report.Error (1908, a.Location, "The type of the default value should match the type of the parameter");
+                                       a.Report.Error (1908, a.Location, "The type of the default value should match the type of the parameter");
                                return;
                        }
 
-                       base.ApplyAttributeBuilder (a, cb);
+                       base.ApplyAttributeBuilder (a, cb, pa);
                }
                
                public virtual bool CheckAccessibility (InterfaceMemberBase member)
@@ -345,66 +334,132 @@ namespace Mono.CSharp {
                        return member.IsAccessibleAs (parameter_type);
                }
 
-               public override IResolveContext ResolveContext {
-                       get {
-                               return resolve_context;
-                       }
-               }
-
                // <summary>
                //   Resolve is used in method definitions
                // </summary>
-               public virtual Type Resolve (IResolveContext ec)
+               public virtual Type Resolve (IMemberContext rc)
                {
-                       // HACK: to resolve attributes correctly
-                       this.resolve_context = ec;
-
                        if (parameter_type != null)
                                return parameter_type;
 
-                       TypeExpr texpr = TypeName.ResolveAsTypeTerminal (ec, false);
+                       if (attributes != null)
+                               attributes.AttachTo (this, rc);
+
+                       TypeExpr texpr = TypeName.ResolveAsTypeTerminal (rc, false);
                        if (texpr == null)
                                return null;
 
                        parameter_type = texpr.Type;
 
+                       // Ignore all checks for dummy members
+                       AbstractPropertyEventMethod pem = rc as AbstractPropertyEventMethod;
+                       if (pem != null && pem.IsDummy)
+                               return parameter_type;
+
+                       if (default_expr != null)
+                               default_expr = ResolveDefaultValue (new ResolveContext (rc));
+
                        if ((modFlags & Parameter.Modifier.ISBYREF) != 0 &&
                                TypeManager.IsSpecialType (parameter_type)) {
-                               Report.Error (1601, Location, "Method or delegate parameter cannot be of type `{0}'",
+                               rc.Compiler.Report.Error (1601, Location, "Method or delegate parameter cannot be of type `{0}'",
                                        GetSignatureForError ());
                                return null;
                        }
 
-#if GMCS_SOURCE
-                       TypeParameterExpr tparam = texpr as TypeParameterExpr;
-                       if (tparam != null) {
+                       TypeManager.CheckTypeVariance (parameter_type,
+                               (modFlags & Parameter.Modifier.ISBYREF) != 0 ? Variance.None : Variance.Contravariant,
+                               rc);
+
+                       if (TypeManager.IsGenericParameter (parameter_type))
                                return parameter_type;
-                       }
-#endif
 
                        if ((parameter_type.Attributes & Class.StaticClassAttribute) == Class.StaticClassAttribute) {
-                               Report.Error (721, Location, "`{0}': static types cannot be used as parameters",
+                               rc.Compiler.Report.Error (721, Location, "`{0}': static types cannot be used as parameters",
                                        texpr.GetSignatureForError ());
                                return parameter_type;
                        }
 
-                       if ((modFlags & Modifier.This) != 0 && parameter_type.IsPointer) {
-                               Report.Error (1103, Location, "The type of extension method cannot be `{0}'",
+                       if ((modFlags & Modifier.This) != 0 && (parameter_type.IsPointer || TypeManager.IsDynamicType (parameter_type))) {
+                               rc.Compiler.Report.Error (1103, Location, "The extension method cannot be of type `{0}'",
                                        TypeManager.CSharpName (parameter_type));
                        }
 
                        return parameter_type;
                }
 
+               Expression ResolveDefaultValue (ResolveContext rc)
+               {
+                       default_expr = default_expr.Resolve (rc);
+                       if (default_expr == null)
+                               return null;
+
+                       if (!(default_expr is Constant || default_expr is DefaultValueExpression)) {
+                               if (TypeManager.IsNullableType (parameter_type)) {
+                                       rc.Compiler.Report.Error (1770, default_expr.Location,
+                                               "The expression being assigned to nullable optional parameter `{0}' must be default value",
+                                               Name);
+                               } else {
+                                       rc.Compiler.Report.Error (1736, default_expr.Location,
+                                               "The expression being assigned to optional parameter `{0}' must be a constant or default value",
+                                               Name);
+                               }
+
+                               return null;
+                       }
+
+                       if (TypeManager.IsEqual (default_expr.Type, parameter_type))
+                               return default_expr;
+
+                       if (TypeManager.IsNullableType (parameter_type)) {
+                               if (Convert.ImplicitNulableConversion (rc, default_expr, parameter_type) != null)
+                                       return default_expr;
+                       } else {
+                               var res = Convert.ImplicitConversionStandard (rc, default_expr, parameter_type, default_expr.Location);
+                               if (res != null) {
+                                       if (!default_expr.IsNull && TypeManager.IsReferenceType (parameter_type) && parameter_type != TypeManager.string_type) {
+                                               rc.Compiler.Report.Error (1763, default_expr.Location,
+                                                       "Optional parameter `{0}' of type `{1}' can only be initialized with `null'",
+                                                       Name, GetSignatureForError ());
+
+                                               return null;
+                                       }
+
+                                       return res;
+                               }
+                       }
+
+                       rc.Compiler.Report.Error (1750, Location,
+                               "Optional parameter expression of type `{0}' cannot be converted to parameter type `{1}'",
+                               TypeManager.CSharpName (default_expr.Type), GetSignatureForError ());
+
+                       return null;
+               }
+
                public void ResolveVariable (int idx)
                {
                        this.idx = idx;
                }
 
+               public bool HasDefaultValue {
+                       get { return default_expr != null; }
+               }
+
                public bool HasExtensionMethodModifier {
                        get { return (modFlags & Modifier.This) != 0; }
                }
 
+               //
+               // Hoisted parameter variant
+               //
+               public HoistedVariable HoistedVariant {
+                       get {
+                               return hoisted_variant;
+                       }
+                       set {
+                               hoisted_variant = value;
+                       }
+               }
+
                public Modifier ModFlags {
                        get { return modFlags & ~Modifier.This; }
                }
@@ -415,7 +470,8 @@ namespace Mono.CSharp {
                }
 
                ParameterAttributes Attributes {
-                       get { return Parameters.GetParameterAttribute (modFlags); }
+                       get { return ParametersCompiled.GetParameterAttribute (modFlags) |
+                               (HasDefaultValue ? ParameterAttributes.Optional : ParameterAttributes.None); }
                }
 
                public override AttributeTargets AttributeTargets {
@@ -455,12 +511,13 @@ namespace Mono.CSharp {
                        }
                }
 
-               public void IsClsCompliant ()
+               public void IsClsCompliant (IMemberContext ctx)
                {
                        if (AttributeTester.IsClsCompliant (parameter_type))
                                return;
 
-                       Report.Warning (3001, 1, Location, "Argument type `{0}' is not CLS-compliant", GetSignatureForError ());
+                       ctx.Compiler.Report.Warning (3001, 1, Location,
+                               "Argument type `{0}' is not CLS-compliant", GetSignatureForError ());
                }
 
                public virtual void ApplyAttributes (MethodBuilder mb, ConstructorBuilder cb, int index)
@@ -472,6 +529,34 @@ namespace Mono.CSharp {
 
                        if (OptAttributes != null)
                                OptAttributes.Emit ();
+
+                       if (HasDefaultValue) {
+                               //
+                               // Emit constant values for true constants only, the other
+                               // constant-like expressions will rely on default value expression
+                               //
+                               Constant c = default_expr as Constant;
+                               if (c != null) {
+                                       if (default_expr.Type == TypeManager.decimal_type) {
+                                               builder.SetCustomAttribute (Const.CreateDecimalConstantAttribute (c));
+                                       } else {
+                                               builder.SetConstant (c.GetTypedValue ());
+                                       }
+                               }
+                       }
+
+                       if (TypeManager.IsDynamicType (parameter_type)) {
+                               PredefinedAttributes.Get.Dynamic.EmitAttribute (builder);
+                       } else {
+                               var trans_flags = TypeManager.HasDynamicTypeUsed (parameter_type);
+                               if (trans_flags != null) {
+                                       var pa = PredefinedAttributes.Get.DynamicTransform;
+                                       if (pa.Constructor != null || pa.ResolveConstructor (Location, TypeManager.bool_type.MakeArrayType ())) {
+                                               builder.SetCustomAttribute (
+                                                       new CustomAttributeBuilder (pa.Constructor, new object [] { trans_flags }));
+                                       }
+                               }
+                       }
                }
 
                public override string[] ValidAttributeTargets {
@@ -483,32 +568,31 @@ namespace Mono.CSharp {
                public Parameter Clone ()
                {
                        Parameter p = (Parameter) MemberwiseClone ();
-                       if (attributes != null) {
+                       if (attributes != null)
                                p.attributes = attributes.Clone ();
-                               p.attributes.AttachTo (p);
-                       }
 
                        return p;
                }
 
-               public ExpressionStatement CreateExpressionTreeVariable (EmitContext ec)
+               public ExpressionStatement CreateExpressionTreeVariable (BlockContext ec)
                {
                        if ((modFlags & Modifier.ISBYREF) != 0)
-                               Report.Error (1951, Location, "An expression tree parameter cannot use `ref' or `out' modifier");
+                               ec.Report.Error (1951, Location, "An expression tree parameter cannot use `ref' or `out' modifier");
 
-                       LocalInfo variable = ec.CurrentBlock.AddTemporaryVariable (
-                               ResolveParameterExpressionType (ec, Location), Location);
-                       variable.Resolve (ec);
+                       expr_tree_variable = new TemporaryVariable (ResolveParameterExpressionType (ec, Location).Type, Location);
+                       expr_tree_variable = expr_tree_variable.Resolve (ec);
 
-                       expr_tree_variable = new LocalVariableReference (
-                               ec.CurrentBlock, variable.Name, Location, variable, false);
-
-                       ArrayList arguments = new ArrayList (2);
+                       Arguments arguments = new Arguments (2);
                        arguments.Add (new Argument (new TypeOf (
                                new TypeExpression (parameter_type, Location), Location)));
                        arguments.Add (new Argument (new StringConstant (Name, Location)));
                        return new SimpleAssign (ExpressionTreeVariableReference (),
-                               Expression.CreateExpressionFactoryCall ("Parameter", null, arguments, Location));
+                               Expression.CreateExpressionFactoryCall (ec, "Parameter", null, arguments, Location));
+               }
+
+               public Expression DefaultValue {
+                       get { return default_expr; }
+                       set { default_expr = value; }
                }
 
                public void Emit (EmitContext ec)
@@ -541,10 +625,7 @@ namespace Mono.CSharp {
 
                        bool is_ref = (ModFlags & Modifier.ISBYREF) != 0;
                        if (is_ref) {
-                               if (arg_idx <= 255)
-                                       ec.ig.Emit (OpCodes.Ldarg_S, (byte) arg_idx);
-                               else
-                                       ec.ig.Emit (OpCodes.Ldarg, arg_idx);
+                               ParameterReference.EmitLdArg (ec.ig, arg_idx);
                        } else {
                                if (arg_idx <= 255)
                                        ec.ig.Emit (OpCodes.Ldarga_S, (byte) arg_idx);
@@ -561,14 +642,14 @@ namespace Mono.CSharp {
                //
                // System.Linq.Expressions.ParameterExpression type
                //
-               public static TypeExpr ResolveParameterExpressionType (EmitContext ec, Location location)
+               public static TypeExpr ResolveParameterExpressionType (IMemberContext ec, Location location)
                {
                        if (parameter_expr_tree_type != null)
                                return parameter_expr_tree_type;
 
                        Type p_type = TypeManager.parameter_expression_type;
                        if (p_type == null) {
-                               p_type = TypeManager.CoreLookupType ("System.Linq.Expressions", "ParameterExpression", Kind.Class, true);
+                               p_type = TypeManager.CoreLookupType (ec.Compiler, "System.Linq.Expressions", "ParameterExpression", MemberKind.Class, true);
                                TypeManager.parameter_expression_type = p_type;
                        }
 
@@ -577,6 +658,13 @@ namespace Mono.CSharp {
 
                        return parameter_expr_tree_type;
                }
+
+               public void Warning_UselessOptionalParameter (Report Report)
+               {
+                       Report.Warning (1066, 1, Location,
+                               "The default value specified for optional parameter `{0}' will never be used",
+                               Name);
+               }
        }
 
        //
@@ -586,6 +674,7 @@ namespace Mono.CSharp {
        {
                readonly string name;
                readonly Parameter.Modifier modifiers;
+               readonly Expression default_value;
 
                public ParameterData (string name, Parameter.Modifier modifiers)
                {
@@ -593,12 +682,26 @@ namespace Mono.CSharp {
                        this.modifiers = modifiers;
                }
 
+               public ParameterData (string name, Parameter.Modifier modifiers, Expression defaultValue)
+                       : this (name, modifiers)
+               {
+                       this.default_value = defaultValue;
+               }
+
                #region IParameterData Members
 
+               public Expression DefaultValue {
+                       get { return default_value; }
+               }
+
                public bool HasExtensionMethodModifier {
                        get { return (modifiers & Parameter.Modifier.This) != 0; }
                }
 
+               public bool HasDefaultValue {
+                       get { return default_value != null; }
+               }
+
                public Parameter.Modifier ModFlags {
                        get { return modifiers & ~Parameter.Modifier.This; }
                }
@@ -619,6 +722,18 @@ namespace Mono.CSharp {
                protected IParameterData [] parameters;
                protected Type [] types;
 
+               public ParametersCompiled AsCompiled {
+                       get { return (ParametersCompiled) this; }
+               }
+
+               public CallingConventions CallingConvention {
+                       get {
+                               return has_arglist ?
+                                       CallingConventions.VarArgs :
+                                       CallingConventions.Standard;
+                       }
+               }
+
                public int Count {
                        get { return parameters.Length; }
                }
@@ -672,6 +787,19 @@ namespace Mono.CSharp {
                        return types;
                }
 
+               //
+               // Returns the parameter information based on the name
+               //
+               public int GetParameterIndexByName (string name)
+               {
+                       for (int idx = 0; idx < Count; ++idx) {
+                               if (parameters [idx].Name == name)
+                                       return idx;
+                       }
+
+                       return -1;
+               }
+
                public string GetSignatureForError ()
                {
                        StringBuilder sb = new StringBuilder ("(");
@@ -714,7 +842,7 @@ namespace Mono.CSharp {
                        if (FixedParameters [pos].HasExtensionMethodModifier)
                                return "this " + type;
 
-                       Parameter.Modifier mod = FixedParameters [pos].ModFlags & ~Parameter.Modifier.ARGLIST;
+                       Parameter.Modifier mod = FixedParameters [pos].ModFlags;
                        if (mod == 0)
                                return type;
 
@@ -725,14 +853,46 @@ namespace Mono.CSharp {
                        get { return types; }
                        set { types = value; }
                }
+
+#if MS_COMPATIBLE
+               public AParametersCollection InflateTypes (Type[] genArguments, Type[] argTypes)
+               {
+                       AParametersCollection p = (AParametersCollection) MemberwiseClone (); // Clone ();
+
+                       for (int i = 0; i < Count; ++i) {
+                               if (types[i].IsGenericType) {
+                                       Type[] gen_arguments_open = new Type[types[i].GetGenericTypeDefinition ().GetGenericArguments ().Length];
+                                       Type[] gen_arguments = types[i].GetGenericArguments ();
+                                       for (int ii = 0; ii < gen_arguments_open.Length; ++ii) {
+                                               if (gen_arguments[ii].IsGenericParameter) {
+                                                       Type t = argTypes[gen_arguments[ii].GenericParameterPosition];
+                                                       gen_arguments_open[ii] = t;
+                                               } else
+                                                       gen_arguments_open[ii] = gen_arguments[ii];
+                                       }
+
+                                       p.types[i] = types[i].GetGenericTypeDefinition ().MakeGenericType (gen_arguments_open);
+                                       continue;
+                               }
+
+                               if (types[i].IsGenericParameter) {
+                                       Type gen_argument = argTypes[types[i].GenericParameterPosition];
+                                       p.types[i] = gen_argument;
+                                       continue;
+                               }
+                       }
+
+                       return p;
+               }
+#endif
        }
 
        //
        // A collection of imported or resolved parameters
        //
-       public class ParametersCollection : AParametersCollection
+       public class ParametersImported : AParametersCollection
        {
-               ParametersCollection (AParametersCollection param, Type[] types)
+               ParametersImported (AParametersCollection param, Type[] types)
                {
                        this.parameters = param.FixedParameters;
                        this.types = types;
@@ -740,23 +900,15 @@ namespace Mono.CSharp {
                        has_params = param.HasParams;
                }
 
-               ParametersCollection (IParameterData [] parameters, Type [] types, MethodBase method, bool hasParams)
+               ParametersImported (IParameterData [] parameters, Type [] types, bool hasArglist, bool hasParams)
                {
                        this.parameters = parameters;
                        this.types = types;
-                       has_arglist = (method.CallingConvention & CallingConventions.VarArgs) != 0;
-                       if (has_arglist) {
-                               this.parameters = new IParameterData [parameters.Length + 1];
-                               parameters.CopyTo (this.parameters, 0);
-                               this.parameters [parameters.Length] = new ArglistParameter (Location.Null);
-                               this.types = new Type [types.Length + 1];
-                               types.CopyTo (this.types, 0);
-                               this.types [types.Length] = TypeManager.arg_iterator_type;
-                       }
-                       has_params = hasParams;
+                       this.has_arglist = hasArglist;
+                       this.has_params = hasParams;
                }
 
-               public ParametersCollection (IParameterData [] param, Type[] types)
+               public ParametersImported (IParameterData [] param, Type[] types)
                {
                        this.parameters = param;
                        this.types = types;
@@ -785,7 +937,7 @@ namespace Mono.CSharp {
                                types [i] = TypeManager.TypeToCoreType (t);
                        }
 
-                       return new ParametersCollection (param, types);
+                       return new ParametersImported (param, types);
                }
 
                //
@@ -793,21 +945,22 @@ namespace Mono.CSharp {
                //
                public static AParametersCollection Create (ParameterInfo [] pi, MethodBase method)
                {
-                       if (pi.Length == 0) {
-                               if (method != null && (method.CallingConvention & CallingConventions.VarArgs) != 0)
-                                       return new ParametersCollection (new IParameterData [0], Type.EmptyTypes, method, false);
+                       int varargs = method != null && (method.CallingConvention & CallingConventions.VarArgs) != 0 ? 1 : 0;
 
-                               return Parameters.EmptyReadOnlyParameters;
-                       }
+                       if (pi.Length == 0 && varargs == 0)
+                               return ParametersCompiled.EmptyReadOnlyParameters;
 
-                       Type [] types = new Type [pi.Length];
-                       IParameterData [] par = new IParameterData [pi.Length];
+                       Type [] types = new Type [pi.Length + varargs];
+                       IParameterData [] par = new IParameterData [pi.Length + varargs];
                        bool is_params = false;
-                       for (int i = 0; i < types.Length; i++) {
+                       PredefinedAttribute extension_attr = PredefinedAttributes.Get.Extension;
+                       PredefinedAttribute param_attr = PredefinedAttributes.Get.ParamArray;
+                       for (int i = 0; i < pi.Length; i++) {
                                types [i] = TypeManager.TypeToCoreType (pi [i].ParameterType);
 
                                ParameterInfo p = pi [i];
                                Parameter.Modifier mod = 0;
+                               Expression default_value = null;
                                if (types [i].IsByRef) {
                                        if ((p.Attributes & (ParameterAttributes.Out | ParameterAttributes.In)) == ParameterAttributes.Out)
                                                mod = Parameter.Modifier.OUT;
@@ -818,48 +971,67 @@ namespace Mono.CSharp {
                                        // Strip reference wrapping
                                        //
                                        types [i] = TypeManager.GetElementType (types [i]);
-                               } else if (i == 0 && TypeManager.extension_attribute_type != null && method != null && method.IsStatic &&
+                               } else if (i == 0 && extension_attr.IsDefined && method != null && method.IsStatic &&
                                (method.DeclaringType.Attributes & Class.StaticClassAttribute) == Class.StaticClassAttribute &&
-                               method.IsDefined (TypeManager.extension_attribute_type, false)) {
+                                       method.IsDefined (extension_attr.Type, false)) {
                                        mod = Parameter.Modifier.This;
-                               } else if (i >= pi.Length - 2 && types [i].IsArray) {
-                                       if (p.IsDefined (TypeManager.param_array_type, false)) {
-                                               mod = Parameter.Modifier.PARAMS;
-                                               is_params = true;
+                               } else {
+                                       if (i >= pi.Length - 2 && types[i].IsArray) {
+                                               if (p.IsDefined (param_attr.Type, false)) {
+                                                       mod = Parameter.Modifier.PARAMS;
+                                                       is_params = true;
+                                               }
+                                       }
+
+                                       if (!is_params && p.IsOptional) {
+                                               object value = p.DefaultValue;
+                                               if (value == Missing.Value) {
+                                                       default_value = EmptyExpression.Null;
+                                               } else if (value == null) {
+                                                       default_value = new NullLiteral (Location.Null);
+                                               } else {
+                                                       default_value = Constant.CreateConstant (null, value.GetType (), value, Location.Null);
+                                               }
                                        }
                                }
 
-                               par [i] = new ParameterData (p.Name, mod);
+                               par [i] = new ParameterData (p.Name, mod, default_value);
+                       }
+
+                       if (varargs != 0) {
+                               par [par.Length - 1] = new ArglistParameter (Location.Null);
+                               types [types.Length - 1] = InternalType.Arglist;
                        }
 
                        return method != null ?
-                               new ParametersCollection (par, types, method, is_params) :
-                               new ParametersCollection (par, types);
+                               new ParametersImported (par, types, varargs != 0, is_params) :
+                               new ParametersImported (par, types);
                }
        }
 
        /// <summary>
        ///   Represents the methods parameters
        /// </summary>
-       public class Parameters : AParametersCollection {
-               public static readonly Parameters EmptyReadOnlyParameters = new Parameters ();
+       public class ParametersCompiled : AParametersCollection
+       {
+               public static readonly ParametersCompiled EmptyReadOnlyParameters = new ParametersCompiled ();
                
                // Used by C# 2.0 delegates
-               public static readonly Parameters Undefined = new Parameters ();
+               public static readonly ParametersCompiled Undefined = new ParametersCompiled ();
 
-               private Parameters ()
+               private ParametersCompiled ()
                {
                        parameters = new Parameter [0];
                        types = Type.EmptyTypes;
                }
 
-               private Parameters (Parameter [] parameters, Type [] types)
+               private ParametersCompiled (Parameter [] parameters, Type [] types)
                {
                        this.parameters = parameters;
                    this.types = types;
                }
                
-               public Parameters (params Parameter[] parameters)
+               public ParametersCompiled (CompilerContext ctx, params Parameter[] parameters)
                {
                        if (parameters == null)
                                throw new ArgumentException ("Use EmptyReadOnlyParameters");
@@ -883,32 +1055,31 @@ namespace Mono.CSharp {
                                        if (base_name != parameters [j].Name)
                                                continue;
 
-                                       Report.Error (100, parameters [i].Location,
-                                               "The parameter name `{0}' is a duplicate", base_name);
+                                       ErrorDuplicateName (parameters[i], ctx.Report);
                                        i = j;
                                }
                        }
                }
 
-               public Parameters (Parameter [] parameters, bool has_arglist) :
-                       this (parameters)
+               public ParametersCompiled (CompilerContext ctx, Parameter [] parameters, bool has_arglist) :
+                       this (ctx, parameters)
                {
                        this.has_arglist = has_arglist;
                }
                
-               public static Parameters CreateFullyResolved (Parameter p, Type type)
+               public static ParametersCompiled CreateFullyResolved (Parameter p, Type type)
                {
-                       return new Parameters (new Parameter [] { p }, new Type [] { type });
+                       return new ParametersCompiled (new Parameter [] { p }, new Type [] { type });
                }
                
-               public static Parameters CreateFullyResolved (Parameter[] parameters, Type[] types)
+               public static ParametersCompiled CreateFullyResolved (Parameter[] parameters, Type[] types)
                {
-                       return new Parameters (parameters, types);
+                       return new ParametersCompiled (parameters, types);
                }
 
-               public static Parameters MergeGenerated (Parameters userParams, bool checkConflicts, Parameter compilerParams, Type compilerTypes)
+               public static ParametersCompiled MergeGenerated (CompilerContext ctx, ParametersCompiled userParams, bool checkConflicts, Parameter compilerParams, Type compilerTypes)
                {
-                       return MergeGenerated (userParams, checkConflicts,
+                       return MergeGenerated (ctx, userParams, checkConflicts,
                                new Parameter [] { compilerParams },
                                new Type [] { compilerTypes });
                }
@@ -916,7 +1087,7 @@ namespace Mono.CSharp {
                //
                // Use this method when you merge compiler generated parameters with user parameters
                //
-               public static Parameters MergeGenerated (Parameters userParams, bool checkConflicts, Parameter[] compilerParams, Type[] compilerTypes)
+               public static ParametersCompiled MergeGenerated (CompilerContext ctx, ParametersCompiled userParams, bool checkConflicts, Parameter[] compilerParams, Type[] compilerTypes)
                {
                        Parameter[] all_params = new Parameter [userParams.Count + compilerParams.Length];
                        userParams.FixedParameters.CopyTo(all_params, 0);
@@ -935,7 +1106,7 @@ namespace Mono.CSharp {
                                for (int i = 0; i < last_filled; ++i) {
                                        while (p.Name == all_params [i].Name) {
                                                if (checkConflicts && i < userParams.Count) {
-                                                       Report.Error (316, userParams [i].Location,
+                                                       ctx.Report.Error (316, userParams[i].Location,
                                                                "The parameter name `{0}' conflicts with a compiler generated name", p.Name);
                                                }
                                                p.Name = '_' + p.Name;
@@ -947,45 +1118,21 @@ namespace Mono.CSharp {
                                ++last_filled;
                        }
                        
-                       Parameters parameters = new Parameters (all_params, all_types);
+                       ParametersCompiled parameters = new ParametersCompiled (all_params, all_types);
                        parameters.has_params = userParams.has_params;
                        return parameters;
                }
 
-               /// <summary>
-               ///    Returns the paramenter information based on the name
-               /// </summary>
-               public Parameter GetParameterByName (string name, out int idx)
+               protected virtual void ErrorDuplicateName (Parameter p, Report Report)
                {
-                       idx = 0;
-
-                       if (Count == 0)
-                               return null;
-
-                       int i = 0;
-
-                       foreach (Parameter par in FixedParameters){
-                               if (par.Name == name){
-                                       idx = i;
-                                       return par;
-                               }
-                               i++;
-                       }
-                       return null;
+                       Report.Error (100, p.Location, "The parameter name `{0}' is a duplicate", p.Name);
                }
 
-               public Parameter GetParameterByName (string name)
-               {
-                       int idx;
-
-                       return GetParameterByName (name, out idx);
-               }
-               
-               public bool Resolve (IResolveContext ec)
+               public bool Resolve (IMemberContext ec)
                {
                        if (types != null)
                                return true;
-
+                       
                        types = new Type [Count];
                        
                        bool ok = true;
@@ -1011,16 +1158,6 @@ namespace Mono.CSharp {
                        }
                }
 
-               public CallingConventions CallingConvention
-               {
-                       get {
-                               if (HasArglist)
-                                       return CallingConventions.VarArgs;
-                               else
-                                       return CallingConventions.Standard;
-                       }
-               }
-
                // Define each type attribute (in/out/ref) and
                // the argument names.
                public void ApplyAttributes (MethodBase builder)
@@ -1036,50 +1173,19 @@ namespace Mono.CSharp {
                        }
                }
 
-#if MS_COMPATIBLE
-               public AParametersCollection InflateTypes (Type[] genArguments, Type[] argTypes)
-               {
-                       Parameters p = Clone ();
-                       for (int i = 0; i < Count; ++i) {
-                               if (types[i].IsGenericType) {
-                                       Type[] gen_arguments_open = new Type [types[i].GetGenericTypeDefinition ().GetGenericArguments ().Length];
-                                       Type[] gen_arguments = types[i].GetGenericArguments ();
-                                       for (int ii = 0; ii < gen_arguments_open.Length; ++ii) {
-                                               if (gen_arguments[ii].IsGenericParameter) {
-                                                       Type t = argTypes[gen_arguments[ii].GenericParameterPosition];
-                                                       gen_arguments_open[ii] = t;
-                                               } else
-                                                       gen_arguments_open[ii] = gen_arguments[ii];
-                                       }
-
-                                       p.types[i] = types[i].GetGenericTypeDefinition ().MakeGenericType (gen_arguments_open);
-                                       continue;
-                               }
-
-                               if (types[i].IsGenericParameter) {
-                                       Type gen_argument = argTypes[types[i].GenericParameterPosition];
-                                       p.types[i] = gen_argument;
-                                       continue;
-                               }
-                       }
-
-                       return p;
-               }
-#endif
-
-               public void VerifyClsCompliance ()
+               public void VerifyClsCompliance (IMemberContext ctx)
                {
                        foreach (Parameter p in FixedParameters)
-                               p.IsClsCompliant ();
+                               p.IsClsCompliant (ctx);
                }
 
                public Parameter this [int pos] {
                        get { return (Parameter) parameters [pos]; }
                }
 
-               public Expression CreateExpressionTree (EmitContext ec, Location loc)
+               public Expression CreateExpressionTree (BlockContext ec, Location loc)
                {
-                       ArrayList initializers = new ArrayList (Count);
+                       var initializers = new ArrayInitializer (Count, loc);
                        foreach (Parameter p in FixedParameters) {
                                //
                                // Each parameter expression is stored to local variable
@@ -1097,16 +1203,15 @@ namespace Mono.CSharp {
                                "[]", initializers, loc);
                }
 
-               public Parameters Clone ()
+               public ParametersCompiled Clone ()
                {
-                       Parameter [] parameters_copy = new Parameter [FixedParameters.Length];
-                       int i = 0;
-                       foreach (Parameter p in FixedParameters)
-                               parameters_copy [i++] = p.Clone ();
-                       Parameters ps = new Parameters (parameters_copy, HasArglist);
-                       if (types != null)
-                               ps.types = (Type[])types.Clone ();
-                       return ps;
+                       ParametersCompiled p = (ParametersCompiled) MemberwiseClone ();
+
+                       p.parameters = new IParameterData [parameters.Length];
+                       for (int i = 0; i < Count; ++i)
+                               p.parameters [i] = this [i].Clone ();
+
+                       return p;
                }
        }
 }