2005-01-31 Zoltan Varga <vargaz@freemail.hu>
[mono.git] / mcs / mcs / expression.cs
old mode 100755 (executable)
new mode 100644 (file)
index c967426..7ea0a61
@@ -66,7 +66,8 @@ namespace Mono.CSharp {
                                 return null;
 
                         args.Add (a);
-                       method = Invocation.OverloadResolve (ec, (MethodGroupExpr) mg, args, loc);
+                       method = Invocation.OverloadResolve (
+                               ec, (MethodGroupExpr) mg, args, false, loc);
 
                        if (method == null)
                                return null;
@@ -216,6 +217,10 @@ namespace Mono.CSharp {
                                e = new IntConstant (-((ShortConstant) expr).Value);
                        else if (expr is UShortConstant)
                                e = new IntConstant (-((UShortConstant) expr).Value);
+                       else if (expr is SByteConstant)
+                               e = new IntConstant (-((SByteConstant) expr).Value);
+                       else if (expr is ByteConstant)
+                               e = new IntConstant (-((ByteConstant) expr).Value);
                        return e;
                }
 
@@ -236,7 +241,7 @@ namespace Mono.CSharp {
                                
                        case Operator.UnaryNegation:
                                result = TryReduceNegative (e);
-                               return true;
+                               return result != null;
                                
                        case Operator.LogicalNot:
                                if (expr_type != TypeManager.bool_type) {
@@ -322,11 +327,22 @@ namespace Mono.CSharp {
 
                Expression ResolveOperator (EmitContext ec)
                {
-                       Type expr_type = Expr.Type;
+                       //
+                       // Step 1: Default operations on CLI native types.
+                       //
+
+                       // Attempt to use a constant folding operation.
+                       if (Expr is Constant){
+                               Expression result;
+                               
+                               if (Reduce (ec, (Constant) Expr, out result))
+                                       return result;
+                       }
 
                        //
-                       // Step 1: Perform Operator Overload location
+                       // Step 2: Perform Operator Overload location
                        //
+                       Type expr_type = Expr.Type;
                        Expression mg;
                        string op_name;
                        
@@ -352,18 +368,6 @@ namespace Mono.CSharp {
                        if (expr_type == null)
                                return null;
                        
-                       //
-                       // Step 2: Default operations on CLI native types.
-                       //
-
-                       // Attempt to use a constant folding operation.
-                       if (Expr is Constant){
-                               Expression result;
-                               
-                               if (Reduce (ec, (Constant) Expr, out result))
-                                       return result;
-                       }
-
                        switch (Oper){
                        case Operator.LogicalNot:
                                if (expr_type != TypeManager.bool_type) {
@@ -427,21 +431,34 @@ namespace Mono.CSharp {
                                }
 
                                IVariable variable = Expr as IVariable;
-                               if (!ec.InFixedInitializer && ((variable == null) || !variable.VerifyFixed (false))) {
+                               bool is_fixed = variable != null && variable.VerifyFixed (false);
+
+                               if (!ec.InFixedInitializer && !is_fixed) {
                                        Error (212, "You can only take the address of an unfixed expression inside " +
                                               "of a fixed statement initializer");
                                        return null;
                                }
-                               
-                               if (ec.InFixedInitializer && ((variable != null) && variable.VerifyFixed (false))) {
+
+                               if (ec.InFixedInitializer && is_fixed) {
                                        Error (213, "You can not fix an already fixed expression");
                                        return null;
                                }
 
+                               LocalVariableReference lr = Expr as LocalVariableReference;
+                               if (lr != null){
+                                       if (lr.local_info.IsCaptured){
+                                               AnonymousMethod.Error_AddressOfCapturedVar (lr.Name, loc);
+                                               return null;
+                                       }
+                                       lr.local_info.AddressTaken = true;
+                                       lr.local_info.Used = true;
+                               }
+
                                // According to the specs, a variable is considered definitely assigned if you take
                                // its address.
-                               if ((variable != null) && (variable.VariableInfo != null))
+                               if ((variable != null) && (variable.VariableInfo != null)){
                                        variable.VariableInfo.SetAssigned (ec);
+                               }
 
                                type = TypeManager.GetPointerType (Expr.Type);
                                return this;
@@ -644,7 +661,7 @@ namespace Mono.CSharp {
        // after semantic analysis (this is so we can take the address
        // of an indirection).
        //
-       public class Indirection : Expression, IMemoryLocation, IAssignMethod {
+       public class Indirection : Expression, IMemoryLocation, IAssignMethod, IVariable {
                Expression expr;
                LocalTemporary temporary;
                bool prepared;
@@ -718,6 +735,21 @@ namespace Mono.CSharp {
                {
                        return "*(" + expr + ")";
                }
+
+               #region IVariable Members
+
+               public VariableInfo VariableInfo {
+                       get {
+                               return null;
+                       }
+               }
+
+               public bool VerifyFixed (bool is_expression)
+               {
+                       return true;
+               }
+
+               #endregion
        }
        
        /// <summary>
@@ -862,7 +894,7 @@ namespace Mono.CSharp {
 
                                return null;
                        } else {
-                               expr.Error_UnexpectedKind ("variable, indexer or property access");
+                               expr.Error_UnexpectedKind ("variable, indexer or property access", loc);
                                return null;
                        }
 
@@ -1011,7 +1043,7 @@ namespace Mono.CSharp {
        ///   size. 
        /// </remarks>
        public abstract class Probe : Expression {
-               public readonly Expression ProbeType;
+               public Expression ProbeType;
                protected Expression expr;
                protected Type probe_type;
                
@@ -1030,10 +1062,10 @@ namespace Mono.CSharp {
 
                public override Expression DoResolve (EmitContext ec)
                {
-                       probe_type = ec.DeclSpace.ResolveType (ProbeType, false, loc);
-
-                       if (probe_type == null)
+                       TypeExpr texpr = ProbeType.ResolveAsTypeTerminal (ec, false);
+                       if (texpr == null)
                                return null;
+                       probe_type = texpr.ResolveType (ec);
 
                        CheckObsoleteAttribute (probe_type);
 
@@ -1041,6 +1073,10 @@ namespace Mono.CSharp {
                        if (expr == null)
                                return null;
                        
+                       if (expr.Type.IsPointer) {
+                               Report.Error (244, loc, "\"is\" or \"as\" are not valid on pointer types");
+                               return null;
+                       }
                        return this;
                }
        }
@@ -1161,10 +1197,10 @@ namespace Mono.CSharp {
                        }
                        
                        if (warning_always_matches)
-                               Warning (Message.CS0183_The_given_expression_is_always_of_the_provided_type, TypeManager.CSharpName (probe_type));
+                               Warning (183, "The given expression is always of the provided ('{0}') type", TypeManager.CSharpName (probe_type));
                        else if (warning_never_matches){
                                if (!(probe_type.IsInterface || expr.Type.IsInterface))
-                                       Warning (Message.CS0184_The_given_expression_is_never_of_the_provided_type, TypeManager.CSharpName (probe_type));
+                                       Warning (184, "The given expression is never of the provided ('{0}') type", TypeManager.CSharpName (probe_type));
                        }
 
                        return this;
@@ -1763,13 +1799,19 @@ namespace Mono.CSharp {
                        if (expr == null)
                                return null;
 
-                       type = ec.DeclSpace.ResolveType (target_type, false, Location);
-                       
-                       if (type == null)
+                       TypeExpr target = target_type.ResolveAsTypeTerminal (ec, false);
+                       if (target == null)
                                return null;
 
+                       type = target.ResolveType (ec);
+
                        CheckObsoleteAttribute (type);
 
+                       if (type.IsAbstract && type.IsSealed) {
+                               Report.Error (716, loc, "Cannot convert to static type '{0}'", TypeManager.CSharpName (type));
+                               return null;
+                       }
+
                        eclass = ExprClass.Value;
 
                        if (expr is Constant){
@@ -2225,8 +2267,8 @@ namespace Mono.CSharp {
                        // Special cases: string comapred to null
                        //
                        if (oper == Operator.Equality || oper == Operator.Inequality){
-                               if ((l == TypeManager.string_type && (right is NullLiteral)) ||
-                                   (r == TypeManager.string_type && (left is NullLiteral))){
+                               if ((!TypeManager.IsValueType (l) && r == TypeManager.null_type) ||
+                                   (!TypeManager.IsValueType (r) && l == TypeManager.null_type)) {
                                        Type = TypeManager.bool_type;
                                        
                                        return this;
@@ -2266,7 +2308,9 @@ namespace Mono.CSharp {
                                        args.Add (new Argument (left, Argument.AType.Expression));
                                        args.Add (new Argument (right, Argument.AType.Expression));
                                        
-                                       MethodBase method = Invocation.OverloadResolve (ec, union, args, Location.Null);
+                                       MethodBase method = Invocation.OverloadResolve (
+                                               ec, union, args, true, Location.Null);
+
                                        if (method != null) {
                                                MethodInfo mi = (MethodInfo) method;
                                                
@@ -2361,8 +2405,8 @@ namespace Mono.CSharp {
                                        //
                                        // Also, a standard conversion must exist from either one
                                        //
-                                       if (!(Convert.ImplicitStandardConversionExists (left, r) ||
-                                             Convert.ImplicitStandardConversionExists (right, l))){
+                                       if (!(Convert.ImplicitStandardConversionExists (ec, left, r) ||
+                                             Convert.ImplicitStandardConversionExists (ec, right, l))){
                                                Error_OperatorCannotBeApplied ();
                                                return null;
                                        }
@@ -2394,14 +2438,17 @@ namespace Mono.CSharp {
                        //
                        if (oper == Operator.Addition || oper == Operator.Subtraction) {
                                if (l.IsSubclassOf (TypeManager.delegate_type)){
-                                       if (right.eclass == ExprClass.MethodGroup && RootContext.V2){
-                                               Expression tmp = Convert.ImplicitConversionRequired (ec, right, l, loc);
-                                               if (tmp == null)
-                                                       return null;
-                                               right = tmp;
-                                               r = right.Type;
+                                       if (((right.eclass == ExprClass.MethodGroup) ||
+                                            (r == TypeManager.anonymous_method_type))){
+                                               if ((RootContext.Version != LanguageVersion.ISO_1)){
+                                                       Expression tmp = Convert.ImplicitConversionRequired (ec, right, l, loc);
+                                                       if (tmp == null)
+                                                               return null;
+                                                       right = tmp;
+                                                       r = right.Type;
+                                               }
                                        }
-                               
+                                       
                                        if (r.IsSubclassOf (TypeManager.delegate_type)){
                                                MethodInfo method;
                                                ArrayList args = new ArrayList (2);
@@ -2449,16 +2496,16 @@ namespace Mono.CSharp {
                                                if (r == l)
                                                        return new PointerArithmetic (
                                                                false, left, right, TypeManager.int64_type,
-                                                               loc);
+                                                               loc).Resolve (ec);
                                        } else {
                                                Expression t = Make32or64 (ec, right);
                                                if (t != null)
-                                                       return new PointerArithmetic (oper == Operator.Addition, left, t, l, loc);
+                                                       return new PointerArithmetic (oper == Operator.Addition, left, t, l, loc).Resolve (ec);
                                        }
                                } else if (r.IsPointer && oper == Operator.Addition){
                                        Expression t = Make32or64 (ec, left);
                                        if (t != null)
-                                               return new PointerArithmetic (true, right, t, r, loc);
+                                               return new PointerArithmetic (true, right, t, r, loc).Resolve (ec);
                                }
                        }
                        
@@ -2658,16 +2705,27 @@ namespace Mono.CSharp {
                                }
                        } else
                                left = left.Resolve (ec);
-                       right = right.Resolve (ec);
 
-                       if (left == null || right == null)
+                       if (left == null)
+                               return null;
+
+                       Constant lc = left as Constant;
+                       if (lc != null && lc.Type == TypeManager.bool_type && 
+                               ((oper == Operator.LogicalAnd && (bool)lc.GetValue () == false) ||
+                                (oper == Operator.LogicalOr && (bool)lc.GetValue () == true))) {
+
+                               // TODO: make a sense to resolve unreachable expression as we do for statement
+                               Report.Warning (429, 4, loc, "Unreachable expression code detected");
+                               return left;
+                       }
+
+                       right = right.Resolve (ec);
+                       if (right == null)
                                return null;
 
                        eclass = ExprClass.Value;
 
                        Constant rc = right as Constant;
-                       Constant lc = left as Constant;
-
                        if (rc != null & lc != null){
                                Expression e = ConstantFold.BinaryFold (
                                        ec, oper, lc, rc, loc);
@@ -3058,7 +3116,11 @@ namespace Mono.CSharp {
        public class StringConcat : Expression {
                ArrayList operands;
                bool invalid = false;
-               
+               bool emit_conv_done = false;
+               //
+               // Are we also concating objects?
+               //
+               bool is_strings_only = true;
                
                public StringConcat (EmitContext ec, Location loc, Expression left, Expression right)
                {
@@ -3112,30 +3174,30 @@ namespace Mono.CSharp {
                {
                        MethodInfo concat_method = null;
                        
-                       //
-                       // Are we also concating objects?
-                       //
-                       bool is_strings_only = true;
-                       
                        //
                        // Do conversion to arguments; check for strings only
                        //
-                       for (int i = 0; i < operands.Count; i ++) {
-                               Expression e = (Expression) operands [i];
-                               is_strings_only &= e.Type == TypeManager.string_type;
-                       }
                        
-                       for (int i = 0; i < operands.Count; i ++) {
-                               Expression e = (Expression) operands [i];
+                       // This can get called multiple times, so we have to deal with that.
+                       if (!emit_conv_done) {
+                               emit_conv_done = true;
+                               for (int i = 0; i < operands.Count; i ++) {
+                                       Expression e = (Expression) operands [i];
+                                       is_strings_only &= e.Type == TypeManager.string_type;
+                               }
                                
-                               if (! is_strings_only && e.Type == TypeManager.string_type) {
-                                       // need to make sure this is an object, because the EmitParams
-                                       // method might look at the type of this expression, see it is a
-                                       // string and emit a string [] when we want an object [];
+                               for (int i = 0; i < operands.Count; i ++) {
+                                       Expression e = (Expression) operands [i];
                                        
-                                       e = Convert.ImplicitConversion (ec, e, TypeManager.object_type, loc);
+                                       if (! is_strings_only && e.Type == TypeManager.string_type) {
+                                               // need to make sure this is an object, because the EmitParams
+                                               // method might look at the type of this expression, see it is a
+                                               // string and emit a string [] when we want an object [];
+                                               
+                                               e = new EmptyCast (e, TypeManager.object_type);
+                                       }
+                                       operands [i] = new Argument (e, Argument.AType.Expression);
                                }
-                               operands [i] = new Argument (e, Argument.AType.Expression);
                        }
                        
                        //
@@ -3272,7 +3334,9 @@ namespace Mono.CSharp {
                        ArrayList arguments = new ArrayList ();
                        arguments.Add (new Argument (left_temp, Argument.AType.Expression));
                        arguments.Add (new Argument (right, Argument.AType.Expression));
-                       method = Invocation.OverloadResolve (ec, (MethodGroupExpr) operator_group, arguments, loc) as MethodInfo;
+                       method = Invocation.OverloadResolve (
+                               ec, (MethodGroupExpr) operator_group, arguments, false, loc)
+                               as MethodInfo;
                        if ((method == null) || (method.ReturnType != type)) {
                                Error19 ();
                                return null;
@@ -3296,8 +3360,6 @@ namespace Mono.CSharp {
                        Label false_target = ig.DefineLabel ();
                        Label end_target = ig.DefineLabel ();
 
-                       ig.Emit (OpCodes.Nop);
-
                        left.Emit (ec);
                        left_temp.Store (ec);
 
@@ -3307,8 +3369,6 @@ namespace Mono.CSharp {
                        ig.MarkLabel (false_target);
                        op.Emit (ec);
                        ig.MarkLabel (end_target);
-
-                       ig.Emit (OpCodes.Nop);
                }
        }
 
@@ -3322,7 +3382,6 @@ namespace Mono.CSharp {
                public PointerArithmetic (bool is_addition, Expression l, Expression r, Type t, Location loc)
                {
                        type = t;
-                       eclass = ExprClass.Variable;
                        this.loc = loc;
                        left = l;
                        right = r;
@@ -3331,9 +3390,13 @@ namespace Mono.CSharp {
 
                public override Expression DoResolve (EmitContext ec)
                {
-                       //
-                       // We are born fully resolved
-                       //
+                       eclass = ExprClass.Variable;
+                       
+                       if (left.Type == TypeManager.void_ptr_type) {
+                               Error (242, "The operation in question is undefined on void pointers");
+                               return null;
+                       }
+                       
                        return this;
                }
 
@@ -3367,19 +3430,31 @@ namespace Mono.CSharp {
                                //
                                left.Emit (ec);
                                ig.Emit (OpCodes.Conv_I);
-                               right.Emit (ec);
-                               if (size != 1){
-                                       if (size == 0)
-                                               ig.Emit (OpCodes.Sizeof, element);
-                                       else 
-                                               IntLiteral.EmitInt (ig, size);
-                                       if (rtype == TypeManager.int64_type)
-                                               ig.Emit (OpCodes.Conv_I8);
-                                       else if (rtype == TypeManager.uint64_type)
-                                               ig.Emit (OpCodes.Conv_U8);
-                                       ig.Emit (OpCodes.Mul);
-                                       ig.Emit (OpCodes.Conv_I);
+
+                               Constant right_const = right as Constant;
+                               if (right_const != null && size != 0) {
+                                       Expression ex = ConstantFold.BinaryFold (ec, Binary.Operator.Multiply, new IntConstant (size), right_const, loc);
+                                       if (ex == null)
+                                               return;
+                                       ex.Emit (ec);
+                               } else {
+                                       right.Emit (ec);
+                                       if (size != 1){
+                                               if (size == 0)
+                                                       ig.Emit (OpCodes.Sizeof, element);
+                                               else 
+                                                       IntLiteral.EmitInt (ig, size);
+                                               if (rtype == TypeManager.int64_type)
+                                                       ig.Emit (OpCodes.Conv_I8);
+                                               else if (rtype == TypeManager.uint64_type)
+                                                       ig.Emit (OpCodes.Conv_U8);
+                                               ig.Emit (OpCodes.Mul);
+                                       }
                                }
+                               
+                               if (rtype == TypeManager.int64_type || rtype == TypeManager.uint64_type)
+                                       ig.Emit (OpCodes.Conv_I);
+                               
                                if (is_add)
                                        ig.Emit (OpCodes.Add);
                                else
@@ -3449,14 +3524,6 @@ namespace Mono.CSharp {
                                Type true_type = trueExpr.Type;
                                Type false_type = falseExpr.Type;
 
-                               if (trueExpr is NullLiteral){
-                                       type = false_type;
-                                       return this;
-                               } else if (falseExpr is NullLiteral){
-                                       type = true_type;
-                                       return this;
-                               }
-                               
                                //
                                // First, if an implicit conversion exists from trueExpr
                                // to falseExpr, then the result type is of type falseExpr.Type
@@ -3488,13 +3555,12 @@ namespace Mono.CSharp {
                                }
                        }
 
+                       // Dead code optimalization
                        if (expr is BoolConstant){
                                BoolConstant bc = (BoolConstant) expr;
 
-                               if (bc.Value)
-                                       return trueExpr;
-                               else
-                                       return falseExpr;
+                               Report.Warning (429, 4, bc.Value ? falseExpr.Location : trueExpr.Location, "Unreachable expression code detected");
+                               return bc.Value ? trueExpr : falseExpr;
                        }
 
                        return this;
@@ -3522,8 +3588,10 @@ namespace Mono.CSharp {
        public class LocalVariableReference : Expression, IAssignMethod, IMemoryLocation, IVariable {
                public readonly string Name;
                public readonly Block Block;
-               LocalInfo local_info;
+               public LocalInfo local_info;
                bool is_readonly;
+               bool prepared;
+               LocalTemporary temp;
                
                public LocalVariableReference (Block block, string name, Location l)
                {
@@ -3533,8 +3601,10 @@ namespace Mono.CSharp {
                        eclass = ExprClass.Variable;
                }
 
+               //
                // Setting `is_readonly' to false will allow you to create a writable
                // reference to a read-only variable.  This is used by foreach and using.
+               //
                public LocalVariableReference (Block block, string name, Location l,
                                               LocalInfo local_info, bool is_readonly)
                        : this (block, name, l)
@@ -3544,7 +3614,9 @@ namespace Mono.CSharp {
                }
 
                public VariableInfo VariableInfo {
-                       get { return local_info.VariableInfo; }
+                       get {
+                               return local_info.VariableInfo;
+                       }
                }
 
                public bool IsReadOnly {
@@ -3553,22 +3625,31 @@ namespace Mono.CSharp {
                        }
                }
 
-               protected void DoResolveBase (EmitContext ec)
+               protected Expression DoResolveBase (EmitContext ec, Expression lvalue_right_side)
                {
                        if (local_info == null) {
                                local_info = Block.GetLocalInfo (Name);
+
+                               // is out param
+                               if (lvalue_right_side == EmptyExpression.Null)
+                                       local_info.Used = true;
+
                                is_readonly = local_info.ReadOnly;
                        }
 
                        type = local_info.VariableType;
-#if false
-                       if (ec.InAnonymousMethod)
-                               Block.LiftVariable (local_info);
-#endif
-               }
 
-               protected Expression DoResolve (EmitContext ec, bool is_lvalue)
-               {
+                       VariableInfo variable_info = local_info.VariableInfo;
+                       if (lvalue_right_side != null){
+                               if (is_readonly){
+                                       Error (1604, "cannot assign to `" + Name + "' because it is readonly");
+                                       return null;
+                               }
+                               
+                               if (variable_info != null)
+                                       variable_info.SetAssigned (ec);
+                       }
+                       
                        Expression e = Block.GetConstantExpression (Name);
                        if (e != null) {
                                local_info.Used = true;
@@ -3576,50 +3657,41 @@ namespace Mono.CSharp {
                                return e.Resolve (ec);
                        }
 
-                       VariableInfo variable_info = local_info.VariableInfo; 
                        if ((variable_info != null) && !variable_info.IsAssigned (ec, loc))
                                return null;
 
-                       if (!is_lvalue)
+                       if (lvalue_right_side == null)
                                local_info.Used = true;
 
-                       if (local_info.LocalBuilder == null)
-                               return ec.RemapLocal (local_info);
-                       
+                       if (ec.CurrentAnonymousMethod != null){
+                               //
+                               // If we are referencing a variable from the external block
+                               // flag it for capturing
+                               //
+                               if (local_info.Block.Toplevel != ec.CurrentBlock.Toplevel){
+                                       if (local_info.AddressTaken){
+                                               AnonymousMethod.Error_AddressOfCapturedVar (local_info.Name, loc);
+                                               return null;
+                                       }
+                                       ec.CaptureVariable (local_info);
+                               }
+                       }
+
                        return this;
                }
                
                public override Expression DoResolve (EmitContext ec)
                {
-                       DoResolveBase (ec);
-
-                       return DoResolve (ec, false);
+                       return DoResolveBase (ec, null);
                }
 
                override public Expression DoResolveLValue (EmitContext ec, Expression right_side)
                {
-                       DoResolveBase (ec);
-
-                       VariableInfo variable_info = local_info.VariableInfo; 
-                       if (variable_info != null)
-                               variable_info.SetAssigned (ec);
-
-                       Expression e = DoResolve (ec, true);
-
-                       if (e == null)
-                               return null;
-
-                       if (is_readonly){
-                               Error (1604, "cannot assign to `" + Name + "' because it is readonly");
-                               return null;
-                       }
-
-                       CheckObsoleteAttribute (e.Type);
-
-                       if (local_info.LocalBuilder == null)
-                               return ec.RemapLocalLValue (local_info, right_side);
+                       Expression ret = DoResolveBase (ec, right_side);
+                       if (ret != null)
+                               CheckObsoleteAttribute (ret.Type);
                        
-                       return this;
+                       return ret;
                }
 
                public bool VerifyFixed (bool is_expression)
@@ -3631,29 +3703,86 @@ namespace Mono.CSharp {
                {
                        ILGenerator ig = ec.ig;
 
-                       ig.Emit (OpCodes.Ldloc, local_info.LocalBuilder);
+                       if (local_info.FieldBuilder == null){
+                               //
+                               // A local variable on the local CLR stack
+                               //
+                               ig.Emit (OpCodes.Ldloc, local_info.LocalBuilder);
+                       } else {
+                               //
+                               // A local variable captured by anonymous methods.
+                               //
+                               if (!prepared)
+                                       ec.EmitCapturedVariableInstance (local_info);
+                               
+                               ig.Emit (OpCodes.Ldfld, local_info.FieldBuilder);
+                       }
                }
                
                public void Emit (EmitContext ec, bool leave_copy)
                {
                        Emit (ec);
-                       if (leave_copy)
+                       if (leave_copy){
                                ec.ig.Emit (OpCodes.Dup);
+                               if (local_info.FieldBuilder != null){
+                                       temp = new LocalTemporary (ec, Type);
+                                       temp.Store (ec);
+                               }
+                       }
                }
                
                public void EmitAssign (EmitContext ec, Expression source, bool leave_copy, bool prepare_for_load)
                {
-                       source.Emit (ec);
-                       if (leave_copy)
-                               ec.ig.Emit (OpCodes.Dup);
-                       ec.ig.Emit (OpCodes.Stloc, local_info.LocalBuilder);
+                       ILGenerator ig = ec.ig;
+                       prepared = prepare_for_load;
+
+                       if (local_info.FieldBuilder == null){
+                               //
+                               // A local variable on the local CLR stack
+                               //
+                               if (local_info.LocalBuilder == null)
+                                       throw new Exception ("This should not happen: both Field and Local are null");
+                               
+                               source.Emit (ec);
+                               if (leave_copy)
+                                       ec.ig.Emit (OpCodes.Dup);
+                               ig.Emit (OpCodes.Stloc, local_info.LocalBuilder);
+                       } else {
+                               //
+                               // A local variable captured by anonymous methods or itereators.
+                               //
+                               ec.EmitCapturedVariableInstance (local_info);
+
+                               if (prepare_for_load)
+                                       ig.Emit (OpCodes.Dup);
+                               source.Emit (ec);
+                               if (leave_copy){
+                                       ig.Emit (OpCodes.Dup);
+                                       temp = new LocalTemporary (ec, Type);
+                                       temp.Store (ec);
+                               }
+                               ig.Emit (OpCodes.Stfld, local_info.FieldBuilder);
+                               if (temp != null)
+                                       temp.Emit (ec);
+                       }
                }
                
                public void AddressOf (EmitContext ec, AddressOp mode)
                {
                        ILGenerator ig = ec.ig;
-                       
-                       ig.Emit (OpCodes.Ldloca, local_info.LocalBuilder);
+
+                       if (local_info.FieldBuilder == null){
+                               //
+                               // A local variable on the local CLR stack
+                               //
+                               ig.Emit (OpCodes.Ldloca, local_info.LocalBuilder);
+                       } else {
+                               //
+                               // A local variable captured by anonymous methods or iterators
+                               //
+                               ec.EmitCapturedVariableInstance (local_info);
+                               ig.Emit (OpCodes.Ldflda, local_info.FieldBuilder);
+                       }
                }
 
                public override string ToString ()
@@ -3674,6 +3803,19 @@ namespace Mono.CSharp {
                VariableInfo vi;
                public Parameter.Modifier mod;
                public bool is_ref, is_out, prepared;
+
+               public bool IsOut {
+                       get {
+                               return is_out;
+                       }
+               }
+
+               public bool IsRef {
+                       get {
+                               return is_ref;
+                       }
+               }
+
                LocalTemporary temp;
                
                public ParameterReference (Parameters pars, Block block, int idx, string name, Location loc)
@@ -3697,8 +3839,7 @@ namespace Mono.CSharp {
 
                public bool IsAssigned (EmitContext ec, Location loc)
                {
-                       if (!ec.DoFlowAnalysis || !is_out ||
-                           ec.CurrentBranching.IsAssigned (vi))
+                       if (!ec.DoFlowAnalysis || !is_out || ec.CurrentBranching.IsAssigned (vi))
                                return true;
 
                        Report.Error (165, loc,
@@ -3708,8 +3849,7 @@ namespace Mono.CSharp {
 
                public bool IsFieldAssigned (EmitContext ec, string field_name, Location loc)
                {
-                       if (!ec.DoFlowAnalysis || !is_out ||
-                           ec.CurrentBranching.IsFieldAssigned (vi, field_name))
+                       if (!ec.DoFlowAnalysis || !is_out || ec.CurrentBranching.IsFieldAssigned (vi, field_name))
                                return true;
 
                        Report.Error (170, loc,
@@ -3723,7 +3863,7 @@ namespace Mono.CSharp {
                                ec.CurrentBranching.SetAssigned (vi);
                }
 
-               public void SetFieldAssigned (EmitContext ec, string field_name)
+               public void SetFieldAssigned (EmitContext ec, string field_name)        
                {
                        if (is_out && ec.DoFlowAnalysis)
                                ec.CurrentBranching.SetFieldAssigned (vi, field_name);
@@ -3731,13 +3871,30 @@ namespace Mono.CSharp {
 
                protected void DoResolveBase (EmitContext ec)
                {
-                       type = pars.GetParameterInfo (ec.DeclSpace, idx, out mod);
+                       type = pars.GetParameterInfo (ec, idx, out mod);
                        is_ref = (mod & Parameter.Modifier.ISBYREF) != 0;
                        is_out = (mod & Parameter.Modifier.OUT) != 0;
                        eclass = ExprClass.Variable;
 
                        if (is_out)
                                vi = block.ParameterMap [idx];
+
+                       if (ec.CurrentAnonymousMethod != null){
+                               if (is_ref){
+                                       Report.Error (1628, Location,
+                                                     "Can not reference a ref or out parameter in an anonymous method");
+                                       return;
+                               }
+                               
+                               //
+                               // If we are referencing the parameter from the external block
+                               // flag it for capturing
+                               //
+                               //Console.WriteLine ("Is parameter `{0}' local? {1}", name, block.IsLocalParameter (name));
+                               if (!block.IsLocalParameter (name)){
+                                       ec.CaptureParameter (name, type, idx);
+                               }
+                       }
                }
 
                //
@@ -3806,17 +3963,25 @@ namespace Mono.CSharp {
                                arg_idx++;
 
                        EmitLdArg (ig, arg_idx);
+
+                       //
+                       // FIXME: Review for anonymous methods
+                       //
                }
                
                public override void Emit (EmitContext ec)
                {
+                       if (ec.HaveCaptureInfo && ec.IsParameterCaptured (name)){
+                               ec.EmitParameter (name);
+                               return;
+                       }
+                       
                        Emit (ec, false);
                }
                
                public void Emit (EmitContext ec, bool leave_copy)
                {
                        ILGenerator ig = ec.ig;
-                       
                        int arg_idx = idx;
 
                        if (!ec.IsStatic)
@@ -3847,6 +4012,11 @@ namespace Mono.CSharp {
                
                public void EmitAssign (EmitContext ec, Expression source, bool leave_copy, bool prepare_for_load)
                {
+                       if (ec.HaveCaptureInfo && ec.IsParameterCaptured (name)){
+                               ec.EmitAssignParameter (name, source, leave_copy, prepare_for_load);
+                               return;
+                       }
+
                        ILGenerator ig = ec.ig;
                        int arg_idx = idx;
                        
@@ -3883,6 +4053,11 @@ namespace Mono.CSharp {
 
                public void AddressOf (EmitContext ec, AddressOp mode)
                {
+                       if (ec.HaveCaptureInfo && ec.IsParameterCaptured (name)){
+                               ec.EmitAddressOfParameter (name);
+                               return;
+                       }
+                       
                        int arg_idx = idx;
 
                        if (!ec.IsStatic)
@@ -3980,9 +4155,19 @@ namespace Mono.CSharp {
                                if (Expr == null)
                                        return false;
 
+                               if (!ec.IsConstructor) {
+                                       FieldExpr fe = Expr as FieldExpr;
+                                       if (fe != null && fe.FieldInfo.IsInitOnly) {
+                                               if (fe.FieldInfo.IsStatic)
+                                                       Report.Error (199, loc, "A static readonly field cannot be passed ref or out (except in a static constructor)");
+                                               else
+                                                       Report.Error (192, loc, "A readonly field cannot be passed ref or out (except in a constructor)");
+                                               return false;
+                                       }
+                               }
                                Expr = Expr.ResolveLValue (ec, Expr);
                        } else if (ArgType == AType.Out)
-                               Expr = Expr.ResolveLValue (ec, new EmptyExpression ());
+                               Expr = Expr.ResolveLValue (ec, EmptyExpression.Null);
                        else
                                Expr = Expr.Resolve (ec);
 
@@ -4002,8 +4187,9 @@ namespace Mono.CSharp {
 
                                        if (instance.GetType () != typeof (This)){
                                                if (fe.InstanceExpression.Type.IsSubclassOf (TypeManager.mbr_type)){
-                                                       Report.Error (197, loc,
-                                                                     "Can not pass a type that derives from MarshalByRefObject with out or ref");
+                                                       Report.SymbolRelatedToPreviousError (fe.InstanceExpression.Type);
+                                                       Report.Error (197, loc, "Cannot pass '{0}' as ref or out or take its address because it is a member of a marshal-by-reference class",
+                                                               fe.Name);
                                                        return false;
                                                }
                                        }
@@ -4048,14 +4234,21 @@ namespace Mono.CSharp {
                                if (Expr is ParameterReference){
                                        ParameterReference pr = (ParameterReference) Expr;
 
-                                       if (pr.is_ref)
+                                       if (pr.IsRef)
                                                pr.EmitLoad (ec);
                                        else {
                                                
                                                pr.AddressOf (ec, mode);
                                        }
                                } else {
-                                       ((IMemoryLocation)Expr).AddressOf (ec, mode);
+                                       if (Expr is IMemoryLocation)
+                                               ((IMemoryLocation) Expr).AddressOf (ec, mode);
+                                       else {
+                                               Report.Error (
+                                                       1510, Expr.Location,
+                                                       "An lvalue is required as an argument to out or ref");
+                                               return;
+                                       }
                                }
                        } else
                                Expr.Emit (ec);
@@ -4070,7 +4263,6 @@ namespace Mono.CSharp {
 
                Expression expr;
                MethodBase method = null;
-               bool is_base;
                
                static Hashtable method_parameter_cache;
 
@@ -4128,10 +4320,11 @@ namespace Mono.CSharp {
                /// <summary>
                ///   Determines "better conversion" as specified in 7.4.2.3
                ///
-                ///    Returns : 1 if a->p is better
-               ///              0 if a->q or neither is better 
+                ///    Returns : p    if a->p is better,
+               ///              q    if a->q is better,
+               ///              null if neither is better
                /// </summary>
-               static int BetterConversion (EmitContext ec, Argument a, Type p, Type q, Location loc)
+               static Type BetterConversion (EmitContext ec, Argument a, Type p, Type q, Location loc)
                {
                        Type argument_type = a.Type;
                        Expression argument_expr = a.Expr;
@@ -4140,81 +4333,85 @@ namespace Mono.CSharp {
                                throw new Exception ("Expression of type " + a.Expr +
                                                      " does not resolve its type");
 
-                       //
-                       // This is a special case since csc behaves this way.
-                       //
-                       if (argument_expr is NullLiteral &&
-                            p == TypeManager.string_type &&
-                            q == TypeManager.object_type)
-                               return 1;
-                       else if (argument_expr is NullLiteral &&
-                                 p == TypeManager.object_type &&
-                                 q == TypeManager.string_type)
-                               return 0;
-                       
-                        //
-                        // csc behaves this way so we emulate it. Basically, if the argument
-                        // is null and one of the types to compare is 'object' and the other
-                        // is a reference type, we prefer the other.
-                        //
-                        // I can't find this anywhere in the spec but we can interpret this
-                        // to mean that null can be of any type you wish in such a context
-                        //
-                        if (p != null && q != null) {
-                                if (argument_expr is NullLiteral &&
-                                    !p.IsValueType &&
-                                    q == TypeManager.object_type)
-                                        return 1;
-                                else if (argument_expr is NullLiteral &&
-                                         !q.IsValueType &&
-                                         p == TypeManager.object_type)
-                                        return 0;
-                        }
-                                
+                       if (p == null || q == null)
+                               throw new InternalErrorException ("BetterConversion Got a null conversion");
+
                        if (p == q)
-                               return 0;
-                       
+                               return null;
+
+                       if (argument_expr is NullLiteral) {
+                               //
+                               // If the argument is null and one of the types to compare is 'object' and
+                               // the other is a reference type, we prefer the other.
+                               //
+                               // This follows from the usual rules:
+                               //   * There is an implicit conversion from 'null' to type 'object'
+                               //   * There is an implicit conversion from 'null' to any reference type
+                               //   * There is an implicit conversion from any reference type to type 'object'
+                               //   * There is no implicit conversion from type 'object' to other reference types
+                               //  => Conversion of 'null' to a reference type is better than conversion to 'object'
+                               //
+                               //  FIXME: This probably isn't necessary, since the type of a NullLiteral is the 
+                               //         null type. I think it used to be 'object' and thus needed a special 
+                               //         case to avoid the immediately following two checks.
+                               //
+                               if (!p.IsValueType && q == TypeManager.object_type)
+                                       return p;
+                               if (!q.IsValueType && p == TypeManager.object_type)
+                                       return q;
+                       }
+                                
                        if (argument_type == p)
-                               return 1;
+                               return p;
 
                        if (argument_type == q)
-                               return 0;
-
-                       if (q == null) {
-                               Expression tmp = Convert.ImplicitConversion (ec, argument_expr, p, loc);
-                               
-                               if (tmp != null)
-                                       return 1;
-                               else
-                                       return 0;
-                       }
+                               return q;
 
                        Expression p_tmp = new EmptyExpression (p);
                        Expression q_tmp = new EmptyExpression (q);
-                       
-                       if (Convert.ImplicitConversionExists (ec, p_tmp, q) == true &&
-                           Convert.ImplicitConversionExists (ec, q_tmp, p) == false)
-                               return 1;
+
+                       bool p_to_q = Convert.ImplicitConversionExists (ec, p_tmp, q);
+                       bool q_to_p = Convert.ImplicitConversionExists (ec, q_tmp, p);
+
+                       if (p_to_q && !q_to_p)
+                               return p;
+
+                       if (q_to_p && !p_to_q)
+                               return q;
 
                        if (p == TypeManager.sbyte_type)
                                if (q == TypeManager.byte_type || q == TypeManager.ushort_type ||
                                    q == TypeManager.uint32_type || q == TypeManager.uint64_type)
-                                       return 1;
+                                       return p;
+                       if (q == TypeManager.sbyte_type)
+                               if (p == TypeManager.byte_type || p == TypeManager.ushort_type ||
+                                   p == TypeManager.uint32_type || p == TypeManager.uint64_type)
+                                       return q;
 
                        if (p == TypeManager.short_type)
                                if (q == TypeManager.ushort_type || q == TypeManager.uint32_type ||
                                    q == TypeManager.uint64_type)
-                                       return 1;
+                                       return p;
+                       if (q == TypeManager.short_type)
+                               if (p == TypeManager.ushort_type || p == TypeManager.uint32_type ||
+                                   p == TypeManager.uint64_type)
+                                       return q;
 
                        if (p == TypeManager.int32_type)
                                if (q == TypeManager.uint32_type || q == TypeManager.uint64_type)
-                                       return 1;
+                                       return p;
+                       if (q == TypeManager.int32_type)
+                               if (p == TypeManager.uint32_type || p == TypeManager.uint64_type)
+                                       return q;
 
                        if (p == TypeManager.int64_type)
                                if (q == TypeManager.uint64_type)
-                                       return 1;
+                                       return p;
+                       if (q == TypeManager.int64_type)
+                               if (p == TypeManager.uint64_type)
+                                       return q;
 
-                       return 0;
+                       return null;
                }
                
                /// <summary>
@@ -4223,23 +4420,16 @@ namespace Mono.CSharp {
                /// </summary>
                /// <remarks>
                ///    Returns an integer indicating :
-               ///     0 if candidate ain't better
-               ///     1 if candidate is better than the current best match
+               ///     false if candidate ain't better
+               ///     true if candidate is better than the current best match
                /// </remarks>
-               static int BetterFunction (EmitContext ec, ArrayList args,
-                                          MethodBase candidate, bool candidate_params,
-                                           MethodBase best, bool best_params,
-                                          Location loc)
+               static bool BetterFunction (EmitContext ec, ArrayList args, int argument_count,
+                                           MethodBase candidate, bool candidate_params,
+                                           MethodBase best, bool best_params, Location loc)
                {
                        ParameterData candidate_pd = GetParameterData (candidate);
-                       ParameterData best_pd;
-                       int argument_count;
+                       ParameterData best_pd = GetParameterData (best);
                
-                       if (args == null)
-                               argument_count = 0;
-                       else
-                               argument_count = args.Count;
-
                        int cand_count = candidate_pd.Count;
                        
                        //
@@ -4264,52 +4454,19 @@ namespace Mono.CSharp {
                        // Trim (); is better than Trim (params char[] chars);
                         //
                        if (cand_count == 0 && argument_count == 0)
-                               return best == null || best_params ? 1 : 0;
+                               return !candidate_params && best_params;
 
                        if ((candidate_pd.ParameterModifier (cand_count - 1) != Parameter.Modifier.PARAMS) &&
                            (candidate_pd.ParameterModifier (cand_count - 1) != Parameter.Modifier.ARGLIST))
                                if (cand_count != argument_count)
-                                       return 0;
-
-                       if (best == null) {
-                               int x = 0;
-
-                               if (argument_count == 0 && cand_count == 1 &&
-                                   candidate_pd.ParameterModifier (cand_count - 1) == Parameter.Modifier.PARAMS)
-                                       return 1;
-                               
-                               for (int j = 0; j < argument_count; ++j) {
-
-                                       Argument a = (Argument) args [j];
-                                       Type t = candidate_pd.ParameterType (j);
-
-                                       if (candidate_pd.ParameterModifier (j) == Parameter.Modifier.PARAMS)
-                                               if (candidate_params)
-                                                       t = TypeManager.GetElementType (t);
-
-                                       x = BetterConversion (ec, a, t, null, loc);
-                                       
-                                       if (x <= 0)
-                                               break;
-                               }
-
-                               if (x > 0)
-                                       return 1;
-                               else
-                                       return 0;
-                       }
-
-                       best_pd = GetParameterData (best);
+                                       return false;
 
-                       int rating1 = 0, rating2 = 0;
-                       
+                       bool better_at_least_one = false;
                        for (int j = 0; j < argument_count; ++j) {
-                               int x, y;
-                               
                                Argument a = (Argument) args [j];
 
-                               Type ct = candidate_pd.ParameterType (j);
-                               Type bt = best_pd.ParameterType (j);
+                               Type ct = TypeManager.TypeToCoreType (candidate_pd.ParameterType (j));
+                               Type bt = TypeManager.TypeToCoreType (best_pd.ParameterType (j));
 
                                if (candidate_pd.ParameterModifier (j) == Parameter.Modifier.PARAMS)
                                        if (candidate_params)
@@ -4319,14 +4476,17 @@ namespace Mono.CSharp {
                                        if (best_params)
                                                bt = TypeManager.GetElementType (bt);
 
-                               x = BetterConversion (ec, a, ct, bt, loc);
-                               y = BetterConversion (ec, a, bt, ct, loc);
+                               Type better = BetterConversion (ec, a, ct, bt, loc);
 
-                               if (x < y)
-                                       return 0;
-                               
-                               rating1 += x;
-                               rating2 += y;
+                               // for each argument, the conversion to 'ct' should be no worse than 
+                               // the conversion to 'bt'.
+                               if (better == bt)
+                                       return false;
+
+                               // for at least one argument, the conversion to 'ct' should be better than 
+                               // the conversion to 'bt'.
+                               if (better == ct)
+                                       better_at_least_one = true;
                        }
 
                         //
@@ -4337,12 +4497,9 @@ namespace Mono.CSharp {
                         // force it to select the candidate
                         //
                         if (!candidate_params && best_params && cand_count == argument_count)
-                                return 1;
+                                return true;
 
-                       if (rating1 > rating2)
-                               return 1;
-                       else
-                               return 0;
+                       return better_at_least_one;
                }
 
                public static string FullMethodDesc (MethodBase mb)
@@ -4423,20 +4580,34 @@ namespace Mono.CSharp {
                        return union;
                }
 
+               static bool IsParamsMethodApplicable (EmitContext ec, MethodGroupExpr me,
+                                                     ArrayList arguments, int arg_count,
+                                                     ref MethodBase candidate)
+               {
+                       return IsParamsMethodApplicable (
+                               ec, me, arguments, arg_count, false, ref candidate) ||
+                               IsParamsMethodApplicable (
+                                       ec, me, arguments, arg_count, true, ref candidate);
+
+
+               }
+
+               static bool IsParamsMethodApplicable (EmitContext ec, MethodGroupExpr me,
+                                                     ArrayList arguments, int arg_count,
+                                                     bool do_varargs, ref MethodBase candidate)
+               {
+                       return IsParamsMethodApplicable (
+                               ec, arguments, arg_count, candidate, do_varargs);
+               }
+
                /// <summary>
                ///   Determines if the candidate method, if a params method, is applicable
                ///   in its expanded form to the given set of arguments
                /// </summary>
                static bool IsParamsMethodApplicable (EmitContext ec, ArrayList arguments,
-                                                     MethodBase candidate, bool do_varargs)
+                                                     int arg_count, MethodBase candidate,
+                                                     bool do_varargs)
                {
-                       int arg_count;
-                       
-                       if (arguments == null)
-                               arg_count = 0;
-                       else
-                               arg_count = arguments.Count;
-                       
                        ParameterData pd = GetParameterData (candidate);
 
                        int pd_count = pd.Count;
@@ -4469,10 +4640,10 @@ namespace Mono.CSharp {
 
                                Argument a = (Argument) arguments [i];
 
-                               Parameter.Modifier a_mod = a.GetParameterModifier () &
-                                       ~(Parameter.Modifier.OUT | Parameter.Modifier.REF);
+                               Parameter.Modifier a_mod = a.GetParameterModifier () & 
+                                       (unchecked (~(Parameter.Modifier.OUT | Parameter.Modifier.REF)));
                                Parameter.Modifier p_mod = pd.ParameterModifier (i) &
-                                       ~(Parameter.Modifier.OUT | Parameter.Modifier.REF);
+                                       (unchecked (~(Parameter.Modifier.OUT | Parameter.Modifier.REF)));
 
                                if (a_mod == p_mod) {
 
@@ -4516,20 +4687,20 @@ namespace Mono.CSharp {
                        return true;
                }
 
+               static bool IsApplicable (EmitContext ec, MethodGroupExpr me,
+                                         ArrayList arguments, int arg_count,
+                                         ref MethodBase candidate)
+               {
+                       return IsApplicable (ec, arguments, arg_count, candidate);
+               }
+
                /// <summary>
                ///   Determines if the candidate method is applicable (section 14.4.2.1)
                ///   to the given set of arguments
                /// </summary>
-               static bool IsApplicable (EmitContext ec, ArrayList arguments, MethodBase candidate)
+               static bool IsApplicable (EmitContext ec, ArrayList arguments, int arg_count,
+                                         MethodBase candidate)
                {
-                       int arg_count;
-
-                       if (arguments == null)
-                               arg_count = 0;
-                       else
-                               arg_count = arguments.Count;
-
-
                        ParameterData pd = GetParameterData (candidate);
 
                        if (arg_count != pd.Count)
@@ -4541,9 +4712,9 @@ namespace Mono.CSharp {
                                Argument a = (Argument) arguments [i];
 
                                Parameter.Modifier a_mod = a.GetParameterModifier () &
-                                       ~(Parameter.Modifier.OUT | Parameter.Modifier.REF);
+                                       unchecked (~(Parameter.Modifier.OUT | Parameter.Modifier.REF));
                                Parameter.Modifier p_mod = pd.ParameterModifier (i) &
-                                       ~(Parameter.Modifier.OUT | Parameter.Modifier.REF);
+                                       unchecked (~(Parameter.Modifier.OUT | Parameter.Modifier.REF));
 
 
                                if (a_mod == p_mod ||
@@ -4570,6 +4741,13 @@ namespace Mono.CSharp {
 
                        return true;
                }
+
+               static private bool IsAncestralType (Type first_type, Type second_type)
+               {
+                       return first_type != second_type &&
+                               (second_type.IsSubclassOf (first_type) ||
+                                TypeManager.ImplementsInterface (second_type, first_type));
+               }
                
                /// <summary>
                ///   Find the Applicable Function Members (7.4.2.1)
@@ -4588,11 +4766,13 @@ namespace Mono.CSharp {
                ///
                /// </summary>
                public static MethodBase OverloadResolve (EmitContext ec, MethodGroupExpr me,
-                                                         ArrayList Arguments, Location loc)
+                                                         ArrayList Arguments, bool may_fail, 
+                                                         Location loc)
                {
                        MethodBase method = null;
+                       bool method_params = false;
                        Type applicable_type = null;
-                       int argument_count;
+                       int arg_count = 0;
                        ArrayList candidates = new ArrayList ();
 
                         //
@@ -4604,169 +4784,200 @@ namespace Mono.CSharp {
                         //
                         Hashtable candidate_to_form = null;
 
+                       if (Arguments != null)
+                               arg_count = Arguments.Count;
 
-                        //
-                        // First we construct the set of applicable methods
-                        //
-                        // We start at the top of the type hierarchy and
-                        // go down to find applicable methods
-                        //
-                        applicable_type = me.DeclaringType;
-                        
-                        if (me.Name == "Invoke" && TypeManager.IsDelegateType (applicable_type)) {
+                        if ((me.Name == "Invoke") &&
+                           TypeManager.IsDelegateType (me.DeclaringType)) {
                                 Error_InvokeOnDelegate (loc);
                                 return null;
                         }
 
-                        bool found_applicable = false;
+                       MethodBase[] methods = me.Methods;
 
-                       foreach (MethodBase candidate in me.Methods){
-                                Type decl_type = candidate.DeclaringType;
+                        //
+                        // First we construct the set of applicable methods
+                        //
+                       bool is_sorted = true;
+                       for (int i = 0; i < methods.Length; i++){
+                                Type decl_type = methods [i].DeclaringType;
 
                                 //
                                 // If we have already found an applicable method
                                 // we eliminate all base types (Section 14.5.5.1)
                                 //
-                                if (decl_type != applicable_type &&
-                                    (applicable_type.IsSubclassOf (decl_type) ||
-                                     TypeManager.ImplementsInterface (applicable_type, decl_type)) &&
-                                    found_applicable)
-                                                continue;
-
+                                if ((applicable_type != null) &&
+                                   IsAncestralType (decl_type, applicable_type))
+                                       continue;
 
+                               //
                                // Check if candidate is applicable (section 14.4.2.1)
-                               if (IsApplicable (ec, Arguments, candidate)) {
-                                        // Candidate is applicable in normal form
-                                        candidates.Add (candidate);
-                                        applicable_type = candidate.DeclaringType;
-                                        found_applicable = true;
-                                } else if (IsParamsMethodApplicable (ec, Arguments, candidate, false)) {
+                               //   Is candidate applicable in normal form?
+                               //
+                               bool is_applicable = IsApplicable (
+                                       ec, me, Arguments, arg_count, ref methods [i]);
+
+                               if (!is_applicable &&
+                                   (IsParamsMethodApplicable (
+                                           ec, me, Arguments, arg_count, ref methods [i]))) {
+                                       MethodBase candidate = methods [i];
                                        if (candidate_to_form == null)
                                                candidate_to_form = new PtrHashtable ();
-                                       
-                                       // Candidate is applicable in expanded form
-                                       candidates.Add (candidate);
-                                       applicable_type = candidate.DeclaringType;
-                                       found_applicable = true; 
                                        candidate_to_form [candidate] = candidate;
-                                } else if (IsParamsMethodApplicable (ec, Arguments, candidate, true)) {
-                                       if (candidate_to_form == null)
-                                               candidate_to_form = new PtrHashtable ();
-                                       
                                        // Candidate is applicable in expanded form
-                                       candidates.Add (candidate);
-                                       applicable_type = candidate.DeclaringType;
-                                       found_applicable = true; 
-                                       candidate_to_form [candidate] = candidate;
+                                       is_applicable = true;
                                }
-                       }
-                        
 
-                        //
-                        // Now we actually find the best method
-                        //
-                       int candidate_top = candidates.Count;
-                       for (int ix = 0; ix < candidate_top; ix++){
-                               MethodBase candidate = (MethodBase) candidates [ix];
+                               if (!is_applicable)
+                                       continue;
 
-                                bool cand_params = candidate_to_form != null && candidate_to_form.Contains (candidate);
-                                bool method_params = false;
+                               candidates.Add (methods [i]);
 
-                                if (method != null)
-                                        method_params = candidate_to_form != null && candidate_to_form.Contains (method);
-                                
-                                int x = BetterFunction (ec, Arguments,
-                                                        candidate, cand_params,
-                                                        method, method_params,
-                                                        loc);
-                                
-                                if (x == 0)
-                                        continue;
-                                
-                                method = candidate;
-                        }
+                               if (applicable_type == null)
+                                       applicable_type = decl_type;
+                               else if (applicable_type != decl_type) {
+                                       is_sorted = false;
+                                       if (IsAncestralType (applicable_type, decl_type))
+                                               applicable_type = decl_type;
+                               }
+                       }
 
-                       if (Arguments == null)
-                               argument_count = 0;
-                       else
-                               argument_count = Arguments.Count;
-                       
+                       int candidate_top = candidates.Count;
 
-                       if (method == null) {
+                       if (candidate_top == 0) {
                                //
                                // Okay so we have failed to find anything so we
                                // return by providing info about the closest match
                                //
-                               for (int i = 0; i < me.Methods.Length; ++i) {
-
-                                       MethodBase c = (MethodBase) me.Methods [i];
+                               for (int i = 0; i < methods.Length; ++i) {
+                                       MethodBase c = (MethodBase) methods [i];
                                        ParameterData pd = GetParameterData (c);
 
-                                       if (pd.Count != argument_count)
+                                       if (pd.Count != arg_count)
                                                continue;
 
-                                       VerifyArgumentsCompat (ec, Arguments, argument_count, c, false,
-                                                              null, loc);
-                                        break;
+                                       VerifyArgumentsCompat (ec, Arguments, arg_count,
+                                                              c, false, null, may_fail, loc);
+                                       break;
                                }
 
-                                if (!Location.IsNull (loc)) {
+                                if (!may_fail) {
                                         string report_name = me.Name;
                                         if (report_name == ".ctor")
                                                 report_name = me.DeclaringType.ToString ();
                                         
-                                        Error_WrongNumArguments (loc, report_name, argument_count);
+                                       Error_WrongNumArguments (
+                                               loc, report_name, arg_count);
+                                       return null;
                                 }
                                 
                                return null;
                        }
 
+                       if (!is_sorted) {
+                               //
+                               // At this point, applicable_type is _one_ of the most derived types
+                               // in the set of types containing the methods in this MethodGroup.
+                               // Filter the candidates so that they only contain methods from the
+                               // most derived types.
+                               //
+
+                               int finalized = 0; // Number of finalized candidates
+
+                               do {
+                                       // Invariant: applicable_type is a most derived type
+
+                                       // We'll try to complete Section 14.5.5.1 for 'applicable_type' by 
+                                       // eliminating all it's base types.  At the same time, we'll also move
+                                       // every unrelated type to the end of the array, and pick the next
+                                       // 'applicable_type'.
+
+                                       Type next_applicable_type = null;
+                                       int j = finalized; // where to put the next finalized candidate
+                                       int k = finalized; // where to put the next undiscarded candidate
+                                       for (int i = finalized; i < candidate_top; ++i) {
+                                               Type decl_type = ((MethodBase) candidates[i]).DeclaringType;
+
+                                               if (decl_type == applicable_type) {
+                                                       candidates[k++] = candidates[j];
+                                                       candidates[j++] = candidates[i];
+                                                       continue;
+                                               }
+
+                                               if (IsAncestralType (decl_type, applicable_type))
+                                                       continue;
+
+                                               if (next_applicable_type != null &&
+                                                   IsAncestralType (decl_type, next_applicable_type))
+                                                       continue;
+
+                                               candidates[k++] = candidates[i];
+
+                                               if (next_applicable_type == null ||
+                                                   IsAncestralType (next_applicable_type, decl_type))
+                                                       next_applicable_type = decl_type;
+                                       }
+
+                                       applicable_type = next_applicable_type;
+                                       finalized = j;
+                                       candidate_top = k;
+                               } while (applicable_type != null);
+                       }
+
+                        //
+                        // Now we actually find the best method
+                        //
+
+                       method = (MethodBase) candidates[0];
+                       method_params = candidate_to_form != null && candidate_to_form.Contains (method);
+                       for (int ix = 1; ix < candidate_top; ix++){
+                               MethodBase candidate = (MethodBase) candidates [ix];
+                               bool cand_params = candidate_to_form != null && candidate_to_form.Contains (candidate);
+                                
+                               if (BetterFunction (ec, Arguments, arg_count, 
+                                                   candidate, cand_params,
+                                                   method, method_params, loc)) {
+                                       method = candidate;
+                                       method_params = cand_params;
+                               }
+                       }
+
                        //
                        // Now check that there are no ambiguities i.e the selected method
                        // should be better than all the others
                        //
-                        bool best_params = candidate_to_form != null && candidate_to_form.Contains (method);
-
+                       bool ambiguous = false;
                        for (int ix = 0; ix < candidate_top; ix++){
                                MethodBase candidate = (MethodBase) candidates [ix];
 
                                 if (candidate == method)
                                         continue;
-                                               
-                               //
-                               // If a normal method is applicable in
-                               // the sense that it has the same
-                               // number of arguments, then the
-                               // expanded params method is never
-                               // applicable so we debar the params
-                               // method.
-                               //
-                                // if ((IsParamsMethodApplicable (ec, Arguments, candidate) &&
-//                                      IsApplicable (ec, Arguments, method)))
-//                                         continue;
-                                
+
                                 bool cand_params = candidate_to_form != null && candidate_to_form.Contains (candidate);
-                               int x = BetterFunction (ec, Arguments,
-                                                        method, best_params,
-                                                        candidate, cand_params,
-                                                       loc);
-
-                               if (x != 1) {
-                                       Report.Error (
-                                               121, loc,
-                                               "Ambiguous call when selecting function due to implicit casts");
-                                       return null;
-                               }
+                               if (!BetterFunction (ec, Arguments, arg_count,
+                                                    method, method_params,
+                                                    candidate, cand_params,
+                                                    loc)) {
+                                       Report.SymbolRelatedToPreviousError (candidate);
+                                       ambiguous = true;
+                               }
                        }
 
+                       if (ambiguous) {
+                               Report.SymbolRelatedToPreviousError (method);
+                               Report.Error (121, loc, "Ambiguous call when selecting function due to implicit casts");
+                               return null;
+                       }
+
+
                        //
                        // And now check if the arguments are all
                        // compatible, perform conversions if
                        // necessary etc. and return if everything is
                        // all right
                        //
-                        if (!VerifyArgumentsCompat (ec, Arguments, argument_count, method,
-                                                    best_params, null, loc))
+                        if (!VerifyArgumentsCompat (ec, Arguments, arg_count, method,
+                                                    method_params, null, may_fail, loc))
                                return null;
 
                        return method;
@@ -4803,16 +5014,15 @@ namespace Mono.CSharp {
                }
                
                public static bool VerifyArgumentsCompat (EmitContext ec, ArrayList Arguments,
-                                                         int argument_count,
-                                                         MethodBase method, 
+                                                         int arg_count, MethodBase method, 
                                                          bool chose_params_expanded,
-                                                         Type delegate_type,
+                                                         Type delegate_type, bool may_fail,
                                                          Location loc)
                {
                        ParameterData pd = GetParameterData (method);
                        int pd_count = pd.Count;
 
-                       for (int j = 0; j < argument_count; j++) {
+                       for (int j = 0; j < arg_count; j++) {
                                Argument a = (Argument) Arguments [j];
                                Expression a_expr = a.Expr;
                                Type parameter_type = pd.ParameterType (j);
@@ -4820,7 +5030,7 @@ namespace Mono.CSharp {
                                
                                if (pm == Parameter.Modifier.PARAMS){
                                        if ((pm & ~Parameter.Modifier.PARAMS) != a.GetParameterModifier ()) {
-                                               if (!Location.IsNull (loc))
+                                               if (!may_fail)
                                                        Error_InvalidArguments (
                                                                loc, j, method, delegate_type,
                                                                Argument.FullDesc (a), pd.ParameterDesc (j));
@@ -4836,7 +5046,7 @@ namespace Mono.CSharp {
                                        // Check modifiers
                                        //
                                        if (pd.ParameterModifier (j) != a.GetParameterModifier ()){
-                                               if (!Location.IsNull (loc))
+                                               if (!may_fail)
                                                        Error_InvalidArguments (
                                                                loc, j, method, delegate_type,
                                                                Argument.FullDesc (a), pd.ParameterDesc (j));
@@ -4847,13 +5057,13 @@ namespace Mono.CSharp {
                                //
                                // Check Type
                                //
-                               if (a.Type != parameter_type){
+                               if (!a.Type.Equals (parameter_type)){
                                        Expression conv;
                                        
                                        conv = Convert.ImplicitConversion (ec, a_expr, parameter_type, loc);
 
                                        if (conv == null) {
-                                               if (!Location.IsNull (loc)) 
+                                               if (!may_fail)
                                                        Error_InvalidArguments (
                                                                loc, j, method, delegate_type,
                                                                Argument.FullDesc (a), pd.ParameterDesc (j));
@@ -4867,14 +5077,21 @@ namespace Mono.CSharp {
                                                a.Expr = conv;
                                }
 
+                               if (parameter_type.IsPointer){
+                                       if (!ec.InUnsafe){
+                                               UnsafeError (loc);
+                                               return false;
+                                       }
+                               }
+                               
                                Parameter.Modifier a_mod = a.GetParameterModifier () &
-                                       ~(Parameter.Modifier.OUT | Parameter.Modifier.REF);
+                                       unchecked (~(Parameter.Modifier.OUT | Parameter.Modifier.REF));
                                Parameter.Modifier p_mod = pd.ParameterModifier (j) &
-                                       ~(Parameter.Modifier.OUT | Parameter.Modifier.REF);
+                                       unchecked (~(Parameter.Modifier.OUT | Parameter.Modifier.REF));
                                
                                if (a_mod != p_mod &&
                                    pd.ParameterModifier (pd_count - 1) != Parameter.Modifier.PARAMS) {
-                                       if (!Location.IsNull (loc)) {
+                                       if (!may_fail) {
                                                Report.Error (1502, loc,
                                                       "The best overloaded match for method '" + FullMethodDesc (method)+
                                                       "' has some invalid arguments");
@@ -4897,9 +5114,6 @@ namespace Mono.CSharp {
                        // First, resolve the expression that is used to
                        // trigger the invocation
                        //
-                       if (expr is BaseAccess)
-                               is_base = true;
-
                        expr = expr.Resolve (ec, ResolveFlags.VariableOrValue | ResolveFlags.MethodGroup);
                        if (expr == null)
                                return null;
@@ -4916,7 +5130,7 @@ namespace Mono.CSharp {
                        }
 
                        if (!(expr is MethodGroupExpr)){
-                               expr.Error_UnexpectedKind (ResolveFlags.MethodGroup);
+                               expr.Error_UnexpectedKind (ResolveFlags.MethodGroup, loc);
                                return null;
                        }
 
@@ -4931,14 +5145,11 @@ namespace Mono.CSharp {
                        }
 
                        MethodGroupExpr mg = (MethodGroupExpr) expr;
-                       method = OverloadResolve (ec, mg, Arguments, loc);
+                       method = OverloadResolve (ec, mg, Arguments, false, loc);
 
-                       if (method == null){
-                               Error (-6,
-                                      "Could not find any applicable function for this argument list");
+                       if (method == null)
                                return null;
-                       }
-                       
+
                        MethodInfo mi = method as MethodInfo;
                        if (mi != null) {
                                type = TypeManager.TypeToCoreType (mi.ReturnType);
@@ -4968,17 +5179,30 @@ namespace Mono.CSharp {
                        //
                        // Only base will allow this invocation to happen.
                        //
-                       if (is_base && method.IsAbstract){
+                       if (mg.IsBase && method.IsAbstract){
                                Report.Error (205, loc, "Cannot call an abstract base member: " +
                                              FullMethodDesc (method));
                                return null;
                        }
 
-                       if ((method.Attributes & MethodAttributes.SpecialName) != 0){
-                               if (TypeManager.IsSpecialMethod (method))
-                                       Report.Error (571, loc, method.Name + ": can not call operator or accessor");
+                       if (method.Name == "Finalize" && Arguments == null) {
+                               if (mg.IsBase)
+                                       Report.Error (250, loc, "Do not directly call your base class Finalize method. It is called automatically from your destructor");
+                               else
+                                       Report.Error (245, loc, "Destructors and object.Finalize cannot be called directly. Consider calling IDisposable.Dispose if available");
+                               return null;
                        }
 
+                       if ((method.Attributes & MethodAttributes.SpecialName) != 0) {
+                               if (TypeManager.LookupDeclSpace (method.DeclaringType) != null || TypeManager.IsSpecialMethod (method)) {
+                                       Report.Error (571, loc, TypeManager.CSharpSignature (method) + ": can not call operator or accessor");
+                                       return null;
+                               }
+                       }
+
+                       if (mg.InstanceExpression != null)
+                               mg.InstanceExpression.CheckMarshallByRefAccess (ec.ContainerType);
+
                        eclass = ExprClass.Value;
                        return this;
                }
@@ -5195,17 +5419,19 @@ namespace Mono.CSharp {
                                        method = TypeManager.void_array_copyto_array_int;
                        }
 
-                       //
-                       // This checks ObsoleteAttribute on the method and on the declaring type
-                       //
-                       ObsoleteAttribute oa = AttributeTester.GetMethodObsoleteAttribute (method);
-                       if (oa != null)
-                               AttributeTester.Report_ObsoleteMessage (oa, TypeManager.CSharpSignature (method), loc);
+                       if (ec.TestObsoleteMethodUsage) {
+                               //
+                               // This checks ObsoleteAttribute on the method and on the declaring type
+                               //
+                               ObsoleteAttribute oa = AttributeTester.GetMethodObsoleteAttribute (method);
+                               if (oa != null)
+                                       AttributeTester.Report_ObsoleteMessage (oa, TypeManager.CSharpSignature (method), loc);
 
 
-                       oa = AttributeTester.GetObsoleteAttribute (method.DeclaringType);
-                       if (oa != null) {
-                               AttributeTester.Report_ObsoleteMessage (oa, method.DeclaringType.FullName, loc);
+                               oa = AttributeTester.GetObsoleteAttribute (method.DeclaringType);
+                               if (oa != null) {
+                                       AttributeTester.Report_ObsoleteMessage (oa, method.DeclaringType.FullName, loc);
+                               }
                        }
 
                        if (IsMethodExcluded (method, ec))
@@ -5304,7 +5530,7 @@ namespace Mono.CSharp {
                {
                        MethodGroupExpr mg = (MethodGroupExpr) this.expr;
 
-                       EmitCall (ec, is_base, method.IsStatic, mg.InstanceExpression, method, Arguments, loc);
+                       EmitCall (ec, mg.IsBase, method.IsStatic, mg.InstanceExpression, method, Arguments, loc);
                }
                
                public override void EmitStatement (EmitContext ec)
@@ -5339,9 +5565,9 @@ namespace Mono.CSharp {
                        //
                        // First try to resolve it as a cast.
                        //
-                       type = ec.DeclSpace.ResolveType (expr, true, loc);
-                       if (type != null) {
-                               Cast cast = new Cast (new TypeExpression (type, loc), argument, loc);
+                       TypeExpr te = expr.ResolveAsTypeTerminal (ec, true);
+                       if (te != null) {
+                               Cast cast = new Cast (te, argument, loc);
                                return cast.Resolve (ec);
                        }
 
@@ -5386,8 +5612,8 @@ namespace Mono.CSharp {
                        //
                        // First try to resolve it as a cast.
                        //
-                       type = ec.DeclSpace.ResolveType (expr, true, loc);
-                       if (type != null) {
+                       TypeExpr te = expr.ResolveAsTypeTerminal (ec, true);
+                       if (te != null) {
                                error201 ();
                                return null;
                        }
@@ -5472,7 +5698,7 @@ namespace Mono.CSharp {
                        value_target = value;
                        value_target_set = true;
                        if (!(value_target is IMemoryLocation)){
-                               Error_UnexpectedKind ("variable");
+                               Error_UnexpectedKind ("variable", loc);
                                return false;
                        }
                        return true;
@@ -5521,10 +5747,11 @@ namespace Mono.CSharp {
                                return this;
                        }
                        
-                       type = ec.DeclSpace.ResolveType (RequestedType, false, loc);
-                       
-                       if (type == null)
+                       TypeExpr texpr = RequestedType.ResolveAsTypeTerminal (ec, false);
+                       if (texpr == null)
                                return null;
+
+                       type = texpr.ResolveType (ec);
                        
                        CheckObsoleteAttribute (type);
 
@@ -5533,11 +5760,16 @@ namespace Mono.CSharp {
                        if (IsDelegate){
                                RequestedType = (new NewDelegate (type, Arguments, loc)).Resolve (ec);
                                if (RequestedType != null)
-                                       if (!(RequestedType is NewDelegate))
+                                       if (!(RequestedType is DelegateCreation))
                                                throw new Exception ("NewDelegate.Resolve returned a non NewDelegate: " + RequestedType.GetType ());
                                return RequestedType;
                        }
 
+                       if (type.IsAbstract && type.IsSealed) {
+                               Report.Error (712, loc, "Cannot create an instance of the static class '{0}'", TypeManager.CSharpName (type));
+                               return null;
+                       }
+
                        if (type.IsInterface || type.IsAbstract){
                                Error (144, "It is not possible to create instances of interfaces or abstract classes");
                                return null;
@@ -5564,7 +5796,7 @@ namespace Mono.CSharp {
                        
                        if (! (ml is MethodGroupExpr)){
                                if (!is_struct){
-                                       ml.Error_UnexpectedKind ("method group");
+                                       ml.Error_UnexpectedKind ("method group", loc);
                                        return null;
                                }
                        }
@@ -5577,11 +5809,17 @@ namespace Mono.CSharp {
                                        }
                                }
 
-                               method = Invocation.OverloadResolve (ec, (MethodGroupExpr) ml, Arguments, loc);
+                               method = Invocation.OverloadResolve (
+                                       ec, (MethodGroupExpr) ml, Arguments, true, loc);
                                
                        }
 
-                       if (method == null) { 
+                       if (method == null) {
+                               if (almostMatchedMembers.Count != 0) {
+                                       MemberLookupFailed (ec, type, type, ".ctor", null, loc);
+                                       return null;
+                               }
+
                                 if (!is_struct || Arguments.Count > 0) {
                                        Error (1501, String.Format (
                                            "New invocation: Can not find a constructor in `{0}' for this argument list",
@@ -5840,7 +6078,7 @@ namespace Mono.CSharp {
                                        Expression tmp = (Expression) o;
                                        tmp = tmp.Resolve (ec);
                                        if (tmp == null)
-                                               continue;
+                                               return false;
 
                                        // Console.WriteLine ("I got: " + tmp);
                                        // Handle initialization from vars, fields etc.
@@ -5935,11 +6173,6 @@ namespace Mono.CSharp {
                        }
                }
 
-               void Error_NegativeArrayIndex ()
-               {
-                       Error (284, "Can not create array with a negative size");
-               }
-               
                //
                // Converts `source' to an int, uint, long or ulong.
                //
@@ -5970,14 +6203,14 @@ namespace Mono.CSharp {
                        if (target is Constant){
                                if (target is IntConstant){
                                        if (((IntConstant) target).Value < 0){
-                                               Error_NegativeArrayIndex ();
+                                               Expression.Error_NegativeArrayIndex (loc);
                                                return null;
                                        }
                                }
 
                                if (target is LongConstant){
                                        if (((LongConstant) target).Value < 0){
-                                               Error_NegativeArrayIndex ();
+                                               Expression.Error_NegativeArrayIndex (loc);
                                                return null;
                                        }
                                }
@@ -6008,16 +6241,19 @@ namespace Mono.CSharp {
                        //
                        // Lookup the type
                        //
-                       Expression array_type_expr;
+                       TypeExpr array_type_expr;
                        array_type_expr = new ComposedCast (requested_base_type, array_qualifier.ToString (), loc);
-                       type = ec.DeclSpace.ResolveType (array_type_expr, false, loc);
-
-                       if (type == null)
+                       array_type_expr = array_type_expr.ResolveAsTypeTerminal (ec, false);
+                       if (array_type_expr == null)
                                return false;
 
-                       underlying_type = type;
-                       if (underlying_type.IsArray)
-                               underlying_type = TypeManager.GetElementType (underlying_type);
+                       type = array_type_expr.ResolveType (ec);
+                       
+                       if (!type.IsArray) {
+                               Error (622, "Can only use array initializer expressions to assign to array types. Try using a new expression instead.");
+                               return false;
+                       }
+                       underlying_type = TypeManager.GetElementType (type);
                        dimensions = type.GetArrayRank ();
 
                        return true;
@@ -6055,6 +6291,11 @@ namespace Mono.CSharp {
                        
                        array_element_type = TypeManager.GetElementType (type);
 
+                       if (array_element_type.IsAbstract && array_element_type.IsSealed) {
+                               Report.Error (719, loc, "'{0}': array elements cannot be of static type", TypeManager.CSharpName (array_element_type));
+                               return null;
+                       }
+
                        if (arg_count == 1) {
                                is_one_dimensional = true;
                                eclass = ExprClass.Value;
@@ -6070,7 +6311,7 @@ namespace Mono.CSharp {
                                                   AllBindingFlags, loc);
                                
                                if (!(ml is MethodGroupExpr)) {
-                                       ml.Error_UnexpectedKind ("method group");
+                                       ml.Error_UnexpectedKind ("method group", loc);
                                        return null;
                                }
                                
@@ -6080,7 +6321,8 @@ namespace Mono.CSharp {
                                        return null;
                                }
                                
-                               new_method = Invocation.OverloadResolve (ec, (MethodGroupExpr) ml, arguments, loc);
+                               new_method = Invocation.OverloadResolve (
+                                       ec, (MethodGroupExpr) ml, arguments, false, loc);
 
                                if (new_method == null) {
                                        Error (-6, "New invocation: Can not find a constructor for " +
@@ -6464,16 +6706,6 @@ namespace Mono.CSharp {
                        }
                        return ret;
                }
-
-               public Expression TurnIntoConstant ()
-               {
-                       //
-                       // Should use something like the above attribute thing.
-                       // It should return a subclass of Constant that just returns
-                       // the computed value of the array
-                       //
-                       throw new Exception ("Does not support yet Turning array into a Constant");
-               }
        }
        
        /// <summary>
@@ -6712,7 +6944,7 @@ namespace Mono.CSharp {
        ///   Implements the typeof operator
        /// </summary>
        public class TypeOf : Expression {
-               public readonly Expression QueriedType;
+               public Expression QueriedType;
                protected Type typearg;
                
                public TypeOf (Expression queried_type, Location l)
@@ -6723,17 +6955,22 @@ namespace Mono.CSharp {
 
                public override Expression DoResolve (EmitContext ec)
                {
-                       typearg = ec.DeclSpace.ResolveType (QueriedType, false, loc);
-
-                       if (typearg == null)
+                       TypeExpr texpr = QueriedType.ResolveAsTypeTerminal (ec, false);
+                       if (texpr == null)
                                return null;
 
+                       typearg = texpr.ResolveType (ec);
+
                        if (typearg == TypeManager.void_type) {
                                Error (673, "System.Void cannot be used from C# - " +
                                       "use typeof (void) to get the void type object");
                                return null;
                        }
 
+                       if (typearg.IsPointer && !ec.InUnsafe){
+                               UnsafeError (loc);
+                               return null;
+                       }
                        CheckObsoleteAttribute (typearg);
 
                        type = TypeManager.type_type;
@@ -6774,7 +7011,7 @@ namespace Mono.CSharp {
        ///   Implements the sizeof expression
        /// </summary>
        public class SizeOf : Expression {
-               public readonly Expression QueriedType;
+               public Expression QueriedType;
                Type type_queried;
                
                public SizeOf (Expression queried_type, Location l)
@@ -6788,14 +7025,16 @@ namespace Mono.CSharp {
                        if (!ec.InUnsafe) {
                                Report.Error (
                                        233, loc, "Sizeof may only be used in an unsafe context " +
-                                       "(consider using System.Runtime.InteropServices.Marshal.Sizeof");
+                                       "(consider using System.Runtime.InteropServices.Marshal.SizeOf");
                                return null;
                        }
-                               
-                       type_queried = ec.DeclSpace.ResolveType (QueriedType, false, loc);
-                       if (type_queried == null)
+
+                       TypeExpr texpr = QueriedType.ResolveAsTypeTerminal (ec, false);
+                       if (texpr == null)
                                return null;
 
+                       type_queried = texpr.ResolveType (ec);
+
                        CheckObsoleteAttribute (type_queried);
 
                        if (!TypeManager.IsUnmanagedType (type_queried)){
@@ -6853,9 +7092,11 @@ namespace Mono.CSharp {
                        if (sn == null || left == null || left.Type.Name != sn.Name)
                                return false;
 
-                       return RootContext.LookupType (ec.DeclSpace, sn.Name, true, loc) != null;
+                       return ec.DeclSpace.LookupType (sn.Name, true, loc) != null;
                }
                
+               // TODO: possible optimalization
+               // Cache resolved constant result in FieldBuilder <-> expresion map
                public static Expression ResolveMemberAccess (EmitContext ec, Expression member_lookup,
                                                              Expression left, Location loc,
                                                              Expression left_original)
@@ -6881,7 +7122,10 @@ namespace Mono.CSharp {
                                FieldInfo fi = fe.FieldInfo;
                                Type decl_type = fi.DeclaringType;
 
-                               if (fi is FieldBuilder) {
+                               bool is_emitted = fi is FieldBuilder;
+                               Type t = fi.FieldType;
+
+                               if (is_emitted) {
                                        Const c = TypeManager.LookupConstant ((FieldBuilder) fi);
                                        
                                        if (c != null) {
@@ -6891,16 +7135,29 @@ namespace Mono.CSharp {
 
                                                object real_value = ((Constant) c.Expr).GetValue ();
 
-                                               return Constantify (real_value, fi.FieldType);
+                                               Expression exp = Constantify (real_value, t);
+
+                                               if (left_is_explicit && !left_is_type && !IdenticalNameAndTypeName (ec, left_original, left, loc)) {
+                                                       Report.SymbolRelatedToPreviousError (c);
+                                                       error176 (loc, c.GetSignatureForError ());
+                                                       return null;
+                                               }
+                                       
+                                               return exp;
                                        }
                                }
 
+                               // IsInitOnly is because of MS compatibility, I don't know why but they emit decimal constant as InitOnly
+                               if (fi.IsInitOnly && !is_emitted && t == TypeManager.decimal_type) {
+                                       object[] attrs = fi.GetCustomAttributes (TypeManager.decimal_constant_attribute_type, false);
+                                       if (attrs.Length == 1)
+                                               return new DecimalConstant (((System.Runtime.CompilerServices.DecimalConstantAttribute) attrs [0]).Value);
+                               }
+
                                if (fi.IsLiteral) {
-                                       Type t = fi.FieldType;
-                                       
                                        object o;
 
-                                       if (fi is FieldBuilder)
+                                       if (is_emitted)
                                                o = TypeManager.GetValue ((FieldBuilder) fi);
                                        else
                                                o = fi.GetValue (fi);
@@ -6937,7 +7194,7 @@ namespace Mono.CSharp {
                                        return exp;
                                }
 
-                               if (fi.FieldType.IsPointer && !ec.InUnsafe){
+                               if (t.IsPointer && !ec.InUnsafe){
                                        UnsafeError (loc);
                                        return null;
                                }
@@ -7062,12 +7319,12 @@ namespace Mono.CSharp {
                        if (expr == null)
                                return null;
 
-                       if (expr is SimpleName){
-                               SimpleName child_expr = (SimpleName) expr;
-
-                               Expression new_expr = new SimpleName (child_expr.Name, Identifier, loc);
-
-                               return new_expr.Resolve (ec, flags);
+                       if (expr is Namespace) {
+                               Namespace ns = (Namespace) expr;
+                               FullNamedExpression retval = ns.Lookup (ec.DeclSpace, Identifier, loc);
+                               if (retval == null)
+                                       Report.Error (234, loc, "The type or namespace name `{0}' could not be found in namespace `{1}'", Identifier, ns.FullName);
+                               return retval;
                        }
                                        
                        //
@@ -7082,7 +7339,7 @@ namespace Mono.CSharp {
                        Type expr_type = expr.Type;
                        if (expr is TypeExpr){
                                if (!ec.DeclSpace.CheckAccessLevel (expr_type)){
-                                       Report.Error (Message.CS0122_is_inaccessible_due_to_its_protection_level, loc, expr_type);
+                                       Report.Error (122, loc, "'{0}' is inaccessible due to its protection level", expr_type);
                                        return null;
                                }
 
@@ -7093,7 +7350,12 @@ namespace Mono.CSharp {
                                                object value = en.LookupEnumValue (ec, Identifier, loc);
                                                
                                                if (value != null){
-                                                       ObsoleteAttribute oa = en.GetObsoleteAttribute (ec, Identifier);
+                                                       MemberCore mc = en.GetDefinition (Identifier);
+                                                       ObsoleteAttribute oa = mc.GetObsoleteAttribute (en);
+                                                       if (oa != null) {
+                                                               AttributeTester.Report_ObsoleteMessage (oa, mc.GetSignatureForError (), Location);
+                                                       }
+                                                       oa = en.GetObsoleteAttribute (en);
                                                        if (oa != null) {
                                                                AttributeTester.Report_ObsoleteMessage (oa, en.GetSignatureForError (), Location);
                                                        }
@@ -7126,7 +7388,8 @@ namespace Mono.CSharp {
                                return null;
 
                        if (member_lookup is TypeExpr) {
-                               if (!(expr is TypeExpr) && !(expr is SimpleName)) {
+                               if (!(expr is TypeExpr) && 
+                                   !IdenticalNameAndTypeName (ec, original, expr, loc)) {
                                        Error (572, "Can't reference type `" + Identifier + "' through an expression; try `" +
                                               member_lookup.Type + "' instead");
                                        return null;
@@ -7152,47 +7415,32 @@ namespace Mono.CSharp {
 
                public override Expression DoResolve (EmitContext ec)
                {
-                       return DoResolve (ec, null, ResolveFlags.VariableOrValue |
-                                         ResolveFlags.SimpleName | ResolveFlags.Type);
+                       return DoResolve (ec, null, ResolveFlags.VariableOrValue | ResolveFlags.Type);
                }
 
                public override Expression DoResolveLValue (EmitContext ec, Expression right_side)
                {
-                       return DoResolve (ec, right_side, ResolveFlags.VariableOrValue |
-                                         ResolveFlags.SimpleName | ResolveFlags.Type);
+                       return DoResolve (ec, right_side, ResolveFlags.VariableOrValue | ResolveFlags.Type);
                }
 
-               public override Expression ResolveAsTypeStep (EmitContext ec)
+               public override FullNamedExpression ResolveAsTypeStep (EmitContext ec)
                {
-                       string fname = null;
-                       MemberAccess full_expr = this;
-                       while (full_expr != null) {
-                               if (fname != null)
-                                       fname = String.Concat (full_expr.Identifier, ".", fname);
-                               else
-                                       fname = full_expr.Identifier;
-
-                               if (full_expr.Expr is SimpleName) {
-                                       string full_name = String.Concat (((SimpleName) full_expr.Expr).Name, ".", fname);
-                                       Type fully_qualified = ec.DeclSpace.FindType (loc, full_name);
-                                       if (fully_qualified != null)
-                                               return new TypeExpression (fully_qualified, loc);
-                               }
-
-                               full_expr = full_expr.Expr as MemberAccess;
-                       }
+                       return ResolveNamespaceOrType (ec, false);
+               }
 
-                       Expression new_expr = expr.ResolveAsTypeStep (ec);
+               public FullNamedExpression ResolveNamespaceOrType (EmitContext ec, bool silent)
+               {
+                       FullNamedExpression new_expr = expr.ResolveAsTypeStep (ec);
 
                        if (new_expr == null)
                                return null;
 
-                       if (new_expr is SimpleName){
-                               SimpleName child_expr = (SimpleName) new_expr;
-                               
-                               new_expr = new SimpleName (child_expr.Name, Identifier, loc);
-
-                               return new_expr.ResolveAsTypeStep (ec);
+                       if (new_expr is Namespace) {
+                               Namespace ns = (Namespace) new_expr;
+                               FullNamedExpression retval = ns.Lookup (ec.DeclSpace, Identifier, loc);
+                               if (!silent && retval == null)
+                                       Report.Error (234, loc, "The type or namespace name `{0}' could not be found in namespace `{1}'", Identifier, ns.FullName);
+                               return retval;
                        }
 
                        Type expr_type = new_expr.Type;
@@ -7203,17 +7451,21 @@ namespace Mono.CSharp {
                                return null;
                        }
                        
-                       Expression member_lookup;
-                       member_lookup = MemberLookupFinal (ec, expr_type, expr_type, Identifier, loc);
-                       if (member_lookup == null)
+                       Expression member_lookup = MemberLookupFinal (ec, expr_type, expr_type, Identifier, loc);
+                       if (!silent && member_lookup == null) {
+                               Report.Error (234, loc, "The type name `{0}' could not be found in type `{1}'", 
+                                             Identifier, new_expr.FullName);
                                return null;
+                       }
 
-                       if (member_lookup is TypeExpr){
-                               member_lookup.Resolve (ec, ResolveFlags.Type);
-                               return member_lookup;
+                       if (!(member_lookup is TypeExpr)) {
+                               Report.Error (118, loc, "'{0}.{1}' denotes a '{2}', where a type was expected",
+                                             new_expr.FullName, Identifier, member_lookup.ExprClassName ());
+                               return null;
                        } 
 
-                       return null;                    
+                       member_lookup = member_lookup.Resolve (ec, ResolveFlags.Type);
+                       return (member_lookup as TypeExpr);
                }
 
                public override void Emit (EmitContext ec)
@@ -7368,7 +7620,7 @@ namespace Mono.CSharp {
                        return true;
                }
 
-               Expression MakePointerAccess ()
+               Expression MakePointerAccess (EmitContext ec)
                {
                        Type t = Expr.Type;
 
@@ -7382,8 +7634,10 @@ namespace Mono.CSharp {
                        }
                        Expression p;
 
-                       p = new PointerArithmetic (true, Expr, ((Argument)Arguments [0]).Expr, t, loc);
-                       return new Indirection (p, loc);
+                       p = new PointerArithmetic (true, Expr, ((Argument)Arguments [0]).Expr, t, loc).Resolve (ec);
+                       if (p == null)
+                               return null;
+                       return new Indirection (p, loc).Resolve (ec);
                }
                
                public override Expression DoResolve (EmitContext ec)
@@ -7407,7 +7661,7 @@ namespace Mono.CSharp {
                        if (t.IsArray)
                                return (new ArrayAccess (this, loc)).Resolve (ec);
                        else if (t.IsPointer)
-                               return MakePointerAccess ();
+                               return MakePointerAccess (ec);
                        else
                                return (new IndexerAccess (this, loc)).Resolve (ec);
                }
@@ -7421,7 +7675,7 @@ namespace Mono.CSharp {
                        if (t.IsArray)
                                return (new ArrayAccess (this, loc)).ResolveLValue (ec, right_side);
                        else if (t.IsPointer)
-                               return MakePointerAccess ();
+                               return MakePointerAccess (ec);
                        else
                                return (new IndexerAccess (this, loc)).ResolveLValue (ec, right_side);
                }
@@ -7485,8 +7739,13 @@ namespace Mono.CSharp {
                                if (argtype == TypeManager.int32_type ||
                                    argtype == TypeManager.uint32_type ||
                                    argtype == TypeManager.int64_type ||
-                                   argtype == TypeManager.uint64_type)
+                                   argtype == TypeManager.uint64_type) {
+                                       Constant c = a.Expr as Constant;
+                                       if (c != null && c.IsNegative) {
+                                               Report.Warning (251, 2, a.Expr.Location, "Indexing an array with a negative index (array indices always start at zero)");
+                                       }
                                        continue;
+                               }
 
                                //
                                // Mhm.  This is strage, because the Argument.Type is not the same as
@@ -7850,10 +8109,9 @@ namespace Mono.CSharp {
                        if (!lookup_type.IsInterface)
                                return ix;
 
-                       TypeExpr [] ifaces = TypeManager.GetInterfaces (lookup_type);
+                       Type [] ifaces = TypeManager.GetInterfaces (lookup_type);
                        if (ifaces != null) {
-                               foreach (TypeExpr iface in ifaces) {
-                                       Type itype = iface.Type;
+                               foreach (Type itype in ifaces) {
                                        MemberInfo [] mi = GetIndexersForTypeOrInterface (caller_type, itype);
                                        if (mi != null){
                                                if (ix == null)
@@ -7937,7 +8195,8 @@ namespace Mono.CSharp {
                        if (AllGetters.Count > 0) {
                                found_any_getters = true;
                                get = (MethodInfo) Invocation.OverloadResolve (
-                                       ec, new MethodGroupExpr (AllGetters, loc), arguments, loc);
+                                       ec, new MethodGroupExpr (AllGetters, loc),
+                                       arguments, false, loc);
                        }
 
                        if (!found_any) {
@@ -7972,6 +8231,8 @@ namespace Mono.CSharp {
                                UnsafeError (loc);
                                return null;
                        }
+
+                       instance_expr.CheckMarshallByRefAccess (ec.ContainerType);
                        
                        eclass = ExprClass.IndexerAccess;
                        return this;
@@ -8001,7 +8262,7 @@ namespace Mono.CSharp {
                                set_arguments.Add (new Argument (right_side, Argument.AType.Expression));
                                set = (MethodInfo) Invocation.OverloadResolve (
                                        ec, new MethodGroupExpr (AllSetters, loc),
-                                       set_arguments, loc);
+                                       set_arguments, false, loc);
                        }
 
                        if (!found_any) {
@@ -8042,6 +8303,8 @@ namespace Mono.CSharp {
                                }
                        }
                        
+                       instance_expr.CheckMarshallByRefAccess (ec.ContainerType);
+
                        eclass = ExprClass.IndexerAccess;
                        return this;
                }
@@ -8229,6 +8492,9 @@ namespace Mono.CSharp {
        ///   is needed (the `New' class).
        /// </summary>
        public class EmptyExpression : Expression {
+               public static readonly EmptyExpression Null = new EmptyExpression ();
+
+               // TODO: should be protected
                public EmptyExpression ()
                {
                        type = TypeManager.object_type;
@@ -8277,6 +8543,12 @@ namespace Mono.CSharp {
                        loc = l;
                }
 
+               public Expression Source {
+                       get {
+                               return source;
+                       }
+               }
+                       
                public override Expression DoResolve (EmitContext ec)
                {
                        //
@@ -8318,10 +8590,12 @@ namespace Mono.CSharp {
 
                public override TypeExpr DoResolveAsTypeStep (EmitContext ec)
                {
-                       Type ltype = ec.DeclSpace.ResolveType (left, false, loc);
-                       if (ltype == null)
+                       TypeExpr lexpr = left.ResolveAsTypeTerminal (ec, false);
+                       if (lexpr == null)
                                return null;
 
+                       Type ltype = lexpr.ResolveType (ec);
+
                        if ((ltype == TypeManager.void_type) && (dim != "*")) {
                                Report.Error (1547, Location,
                                              "Keyword 'void' cannot be used in this context");
@@ -8341,22 +8615,22 @@ namespace Mono.CSharp {
                                //
                                // For now, fall back to the full lookup in that case.
                                //
-                               type = RootContext.LookupType (
-                                       ec.DeclSpace, cname, false, loc);
-
+                               FullNamedExpression e = ec.DeclSpace.LookupType (cname, false, loc);
+                               if (e is TypeExpr)
+                                       type = ((TypeExpr) e).ResolveType (ec);
                                if (type == null)
                                        return null;
                        }
 
-                       if (!ec.ResolvingTypeTree){
-                               //
-                               // If the above flag is set, this is being invoked from the ResolveType function.
-                               // Upper layers take care of the type validity in this context.
-                               //
                        if (!ec.InUnsafe && type.IsPointer){
                                UnsafeError (loc);
                                return null;
                        }
+
+                       if (type.IsArray && (type.GetElementType () == TypeManager.arg_iterator_type ||
+                               type.GetElementType () == TypeManager.typed_reference_type)) {
+                               Report.Error (611, loc, "Array elements cannot be of type '{0}'", TypeManager.CSharpName (type.GetElementType ()));
+                               return null;
                        }
                        
                        eclass = ExprClass.Type;
@@ -8368,6 +8642,12 @@ namespace Mono.CSharp {
                                return left + dim;
                        }
                }
+
+               public override string FullName {
+                       get {
+                               return type.FullName;
+                       }
+               }
        }
 
        //
@@ -8467,9 +8747,8 @@ namespace Mono.CSharp {
                        }
 
                        Constant c = count as Constant;
-                       // TODO: because we don't have property IsNegative
-                       if (c != null && c.ConvertToUInt () == null) {
-                               Report.Error (Message.CS0247_Cannot_use_a_negative_size_with_stackalloc, loc);
+                       if (c != null && c.IsNegative) {
+                               Report.Error (247, loc, "Cannot use a negative size with stackalloc");
                                return null;
                        }
 
@@ -8480,11 +8759,12 @@ namespace Mono.CSharp {
                                return null;
                        }
 
-                       otype = ec.DeclSpace.ResolveType (t, false, loc);
-
-                       if (otype == null)
+                       TypeExpr texpr = t.ResolveAsTypeTerminal (ec, false);
+                       if (texpr == null)
                                return null;
 
+                       otype = texpr.ResolveType (ec);
+
                        if (!TypeManager.VerifyUnManaged (otype, loc))
                                return null;