[xbuild] Set ProjectFile and TargetName metadata on target outputs.
[mono.git] / mcs / mcs / constant.cs
index 16a53cd4137faf3bcd5a2471c89f98de09fcb444..d16e844d5920ddbed58d104da25055d308b45be7 100644 (file)
@@ -5,56 +5,36 @@
 //   Miguel de Icaza (miguel@ximian.com)
 //   Marek Safar (marek.safar@seznam.cz)
 //
-// (C) 2001 Ximian, Inc.
-//
+// Copyright 2001-2003 Ximian, Inc.
+// Copyright 2003-2008 Novell, Inc.
 //
 
-namespace Mono.CSharp {
+using System;
+using System.Globalization;
 
-       using System;
-       using System.Reflection.Emit;
-       using System.Collections;
+#if STATIC
+using IKVM.Reflection.Emit;
+#else
+using System.Reflection.Emit;
+#endif
+
+namespace Mono.CSharp {
 
        /// <summary>
        ///   Base class for constants and literals.
        /// </summary>
-       public abstract class Constant : Expression {
+       public abstract class Constant : Expression
+       {
+               static readonly NumberFormatInfo nfi = CultureInfo.InvariantCulture.NumberFormat;
 
                protected Constant (Location loc)
                {
                        this.loc = loc;
                }
 
-               /// <remarks>
-               ///   This is different from ToString in that ToString
-               ///   is supposed to be there for debugging purposes,
-               ///   and is not guaranteed to be useful for anything else,
-               ///   AsString() will provide something that can be used
-               ///   for round-tripping C# code.  Maybe it can be used
-               ///   for IL assembly as well.
-               /// </remarks>
-               public abstract string AsString ();
-
                override public string ToString ()
                {
-                       return this.GetType ().Name + " (" + AsString () + ")";
-               }
-
-               public override bool GetAttributableValue (Type value_type, out object value)
-               {
-                       if (value_type == TypeManager.object_type) {
-                               value = GetTypedValue ();
-                               return true;
-                       }
-
-                       Constant c = ImplicitConversionRequired (value_type, loc);
-                       if (c == null) {
-                               value = null;
-                               return false;
-                       }
-
-                       value = c.GetTypedValue ();
-                       return true;
+                       return this.GetType ().Name + " (" + GetValueAsLiteral () + ")";
                }
 
                /// <summary>
@@ -63,28 +43,42 @@ namespace Mono.CSharp {
                /// </summary>
                public abstract object GetValue ();
 
+               public abstract long GetValueAsLong ();
+
+               public abstract string GetValueAsLiteral ();
+
+#if !STATIC
+               //
+               // Returns an object value which is typed to contant type
+               //
                public virtual object GetTypedValue ()
                {
                        return GetValue ();
                }
+#endif
 
-               /// <summary>
-               ///   Constants are always born in a fully resolved state
-               /// </summary>
-               public override Expression DoResolve (EmitContext ec)
+               public override void Error_ValueCannotBeConverted (ResolveContext ec, Location loc, TypeSpec target, bool expl)
                {
-                       return this;
+                       if (!expl && IsLiteral && 
+                               BuildinTypeSpec.IsPrimitiveTypeOrDecimal (target) &&
+                               BuildinTypeSpec.IsPrimitiveTypeOrDecimal (type)) {
+                               ec.Report.Error (31, loc, "Constant value `{0}' cannot be converted to a `{1}'",
+                                       GetValueAsLiteral (), TypeManager.CSharpName (target));
+                       } else {
+                               base.Error_ValueCannotBeConverted (ec, loc, target, expl);
+                       }
                }
 
-               public Constant ImplicitConversionRequired (Type type, Location loc)
+               public Constant ImplicitConversionRequired (ResolveContext ec, TypeSpec type, Location loc)
                {
                        Constant c = ConvertImplicitly (type);
                        if (c == null)
-                               Error_ValueCannotBeConverted (null, loc, type, false);
+                               Error_ValueCannotBeConverted (ec, loc, type, false);
+
                        return c;
                }
 
-               public virtual Constant ConvertImplicitly (Type type)
+               public virtual Constant ConvertImplicitly (TypeSpec type)
                {
                        if (this.type == type)
                                return this;
@@ -93,7 +87,7 @@ namespace Mono.CSharp {
                                return null;
 
                        bool fail;                      
-                       object constant_value = TypeManager.ChangeType (GetValue (), type, out fail);
+                       object constant_value = ChangeType (GetValue (), type, out fail);
                        if (fail){
                                //
                                // We should always catch the error before this is ever
@@ -106,91 +100,177 @@ namespace Mono.CSharp {
                        return CreateConstant (type, constant_value, loc);
                }
 
-               ///  Returns a constant instance based on Type
-               ///  The returned value is already resolved.
-               public static Constant CreateConstant (Type t, object v, Location loc)
-               {
-                       if (t == TypeManager.int32_type)
-                               return new IntConstant ((int) v, loc);
-                       if (t == TypeManager.string_type)
-                               return new StringConstant ((string) v, loc);
-                       if (t == TypeManager.uint32_type)
-                               return new UIntConstant ((uint) v, loc);
-                       if (t == TypeManager.int64_type)
-                               return new LongConstant ((long) v, loc);
-                       if (t == TypeManager.uint64_type)
-                               return new ULongConstant ((ulong) v, loc);
-                       if (t == TypeManager.float_type)
-                               return new FloatConstant ((float) v, loc);
-                       if (t == TypeManager.double_type)
-                               return new DoubleConstant ((double) v, loc);
-                       if (t == TypeManager.short_type)
-                               return new ShortConstant ((short)v, loc);
-                       if (t == TypeManager.ushort_type)
-                               return new UShortConstant ((ushort)v, loc);
-                       if (t == TypeManager.sbyte_type)
-                               return new SByteConstant ((sbyte)v, loc);
-                       if (t == TypeManager.byte_type)
-                               return new ByteConstant ((byte)v, loc);
-                       if (t == TypeManager.char_type)
-                               return new CharConstant ((char)v, loc);
-                       if (t == TypeManager.bool_type)
-                               return new BoolConstant ((bool) v, loc);
-                       if (t == TypeManager.decimal_type)
-                               return new DecimalConstant ((decimal) v, loc);
-                       if (TypeManager.IsEnumType (t)) {
-                               Type real_type = TypeManager.TypeToCoreType (v.GetType ());
-                               if (real_type == t)
-                                       real_type = System.Enum.GetUnderlyingType (real_type);
-                               return new EnumConstant (CreateConstant (real_type, v, loc), t);
-                       } 
-                       if (v == null && !TypeManager.IsValueType (t))
-                               return new EmptyConstantCast (new NullLiteral (loc), t);
-
-                       throw new Exception ("Unknown type for constant (" + t +
-                                       "), details: " + v);
-               }
-
-               public override Expression CreateExpressionTree (EmitContext ec)
-               {
-                       ArrayList args = new ArrayList (2);
-                       args.Add (new Argument (this));
-                       args.Add (new Argument (
-                               new TypeOf (new TypeExpression (type, Location), Location)));
+               //
+               //  Returns a constant instance based on Type
+               //
+               public static Constant CreateConstant (TypeSpec t, object v, Location loc)
+               {
+                       return CreateConstantFromValue (t, v, loc);
+               }
+
+               public static Constant CreateConstantFromValue (TypeSpec t, object v, Location loc)
+               {
+                       switch (t.BuildinType) {
+                       case BuildinTypeSpec.Type.Int:
+                               return new IntConstant (t, (int) v, loc);
+                       case BuildinTypeSpec.Type.String:
+                               return new StringConstant (t, (string) v, loc);
+                       case BuildinTypeSpec.Type.UInt:
+                               return new UIntConstant (t, (uint) v, loc);
+                       case BuildinTypeSpec.Type.Long:
+                               return new LongConstant (t, (long) v, loc);
+                       case BuildinTypeSpec.Type.ULong:
+                               return new ULongConstant (t, (ulong) v, loc);
+                       case BuildinTypeSpec.Type.Float:
+                               return new FloatConstant (t, (float) v, loc);
+                       case BuildinTypeSpec.Type.Double:
+                               return new DoubleConstant (t, (double) v, loc);
+                       case BuildinTypeSpec.Type.Short:
+                               return new ShortConstant (t, (short) v, loc);
+                       case BuildinTypeSpec.Type.UShort:
+                               return new UShortConstant (t, (ushort) v, loc);
+                       case BuildinTypeSpec.Type.SByte:
+                               return new SByteConstant (t, (sbyte) v, loc);
+                       case BuildinTypeSpec.Type.Byte:
+                               return new ByteConstant (t, (byte) v, loc);
+                       case BuildinTypeSpec.Type.Char:
+                               return new CharConstant (t, (char) v, loc);
+                       case BuildinTypeSpec.Type.Bool:
+                               return new BoolConstant (t, (bool) v, loc);
+                       case BuildinTypeSpec.Type.Decimal:
+                               return new DecimalConstant (t, (decimal) v, loc);
+                       }
 
-                       return CreateExpressionFactoryCall ("Constant", args);
+                       if (t.IsEnum) {
+                               var real_type = EnumSpec.GetUnderlyingType (t);
+                               return new EnumConstant (CreateConstantFromValue (real_type, v, loc), t);
+                       }
+
+                       if (v == null) {
+                               if (t.IsNullableType)
+                                       return Nullable.LiftedNull.Create (t, loc);
+
+                               if (TypeManager.IsReferenceType (t))
+                                       return new NullConstant (t, loc);
+                       }
+
+                       throw new InternalErrorException ("Constant value `{0}' has unexpected underlying type `{1}'",
+                               v, TypeManager.CSharpName (t));
                }
 
+               public override Expression CreateExpressionTree (ResolveContext ec)
+               {
+                       Arguments args = new Arguments (2);
+                       args.Add (new Argument (this));
+                       args.Add (new Argument (new TypeOf (new TypeExpression (type, loc), loc)));
+
+                       return CreateExpressionFactoryCall (ec, "Constant", args);
+               }
 
                /// <summary>
                /// Maybe ConvertTo name is better. It tries to convert `this' constant to target_type.
                /// It throws OverflowException 
                /// </summary>
                // DON'T CALL THIS METHOD DIRECTLY AS IT DOES NOT HANDLE ENUMS
-               public abstract Constant ConvertExplicitly (bool in_checked_context, Type target_type);
+               public abstract Constant ConvertExplicitly (bool in_checked_context, TypeSpec target_type);
+
+               // This is a custom version of Convert.ChangeType() which works
+               // with the TypeBuilder defined types when compiling corlib.
+               static object ChangeType (object value, TypeSpec targetType, out bool error)
+               {
+                       IConvertible convert_value = value as IConvertible;
+
+                       if (convert_value == null) {
+                               error = true;
+                               return null;
+                       }
+
+                       //
+                       // We cannot rely on build-in type conversions as they are
+                       // more limited than what C# supports.
+                       // See char -> float/decimal/double conversion
+                       //
+                       error = false;
+                       try {
+                               switch (targetType.BuildinType) {
+                               case BuildinTypeSpec.Type.Bool:
+                                       return convert_value.ToBoolean (nfi);
+                               case BuildinTypeSpec.Type.Byte:
+                                       return convert_value.ToByte (nfi);
+                               case BuildinTypeSpec.Type.Char:
+                                       return convert_value.ToChar (nfi);
+                               case BuildinTypeSpec.Type.Short:
+                                       return convert_value.ToInt16 (nfi);
+                               case BuildinTypeSpec.Type.Int:
+                                       return convert_value.ToInt32 (nfi);
+                               case BuildinTypeSpec.Type.Long:
+                                       return convert_value.ToInt64 (nfi);
+                               case BuildinTypeSpec.Type.SByte:
+                                       return convert_value.ToSByte (nfi);
+                               case BuildinTypeSpec.Type.Decimal:
+                                       if (convert_value.GetType () == typeof (char))
+                                               return (decimal) convert_value.ToInt32 (nfi);
+                                       return convert_value.ToDecimal (nfi);
+                               case BuildinTypeSpec.Type.Double:
+                                       if (convert_value.GetType () == typeof (char))
+                                               return (double) convert_value.ToInt32 (nfi);
+                                       return convert_value.ToDouble (nfi);
+                               case BuildinTypeSpec.Type.Float:
+                                       if (convert_value.GetType () == typeof (char))
+                                               return (float) convert_value.ToInt32 (nfi);
+                                       return convert_value.ToSingle (nfi);
+                               case BuildinTypeSpec.Type.String:
+                                       return convert_value.ToString (nfi);
+                               case BuildinTypeSpec.Type.UShort:
+                                       return convert_value.ToUInt16 (nfi);
+                               case BuildinTypeSpec.Type.UInt:
+                                       return convert_value.ToUInt32 (nfi);
+                               case BuildinTypeSpec.Type.ULong:
+                                       return convert_value.ToUInt64 (nfi);
+                               case BuildinTypeSpec.Type.Object:
+                                       return value;
+                               }
+                       } catch {
+                       }
+
+                       error = true;
+                       return null;
+               }
+
+               protected override Expression DoResolve (ResolveContext rc)
+               {
+                       return this;
+               }
 
                /// <summary>
                ///   Attempts to do a compile-time folding of a constant cast.
                /// </summary>
-               public Constant TryReduce (EmitContext ec, Type target_type, Location loc)
+               public Constant TryReduce (ResolveContext ec, TypeSpec target_type, Location loc)
                {
                        try {
                                return TryReduce (ec, target_type);
                        }
                        catch (OverflowException) {
-                               Report.Error (221, loc, "Constant value `{0}' cannot be converted to a `{1}' (use `unchecked' syntax to override)",
-                                       GetValue ().ToString (), TypeManager.CSharpName (target_type));
-                               return null;
+                               if (ec.ConstantCheckState && Type.BuildinType != BuildinTypeSpec.Type.Decimal) {
+                                       ec.Report.Error (221, loc,
+                                               "Constant value `{0}' cannot be converted to a `{1}' (use `unchecked' syntax to override)",
+                                               GetValueAsLiteral (), target_type.GetSignatureForError ());
+                               } else {
+                                       Error_ValueCannotBeConverted (ec, loc, target_type, false);
+                               }
+
+                               return New.Constantify (target_type, loc);
                        }
                }
 
-               Constant TryReduce (EmitContext ec, Type target_type)
+               Constant TryReduce (ResolveContext ec, TypeSpec target_type)
                {
                        if (Type == target_type)
                                return this;
 
+                       Constant c;
                        if (TypeManager.IsEnumType (target_type)) {
-                               Constant c = TryReduce (ec, TypeManager.EnumToUnderlying (target_type));
+                               c = TryReduce (ec, EnumSpec.GetUnderlyingType (target_type));
                                if (c == null)
                                        return null;
 
@@ -200,18 +280,16 @@ namespace Mono.CSharp {
                        return ConvertExplicitly (ec.ConstantCheckState, target_type);
                }
 
-               public abstract Constant Increment ();
-               
                /// <summary>
                /// Need to pass type as the constant can require a boxing
                /// and in such case no optimization is possible
                /// </summary>
-               public bool IsDefaultInitializer (Type type)
+               public bool IsDefaultInitializer (TypeSpec type)
                {
                        if (type == Type)
                                return IsDefaultValue;
 
-                       return Type == TypeManager.null_type;
+                       return this is NullLiteral;
                }
 
                public abstract bool IsDefaultValue {
@@ -222,6 +300,17 @@ namespace Mono.CSharp {
                        get;
                }
 
+               //
+               // When constant is declared as literal
+               //
+               public virtual bool IsLiteral {
+                       get { return false; }
+               }
+               
+               public virtual bool IsOneInteger {
+                       get { return false; }
+               }               
+
                //
                // Returns true iff 1) the stack type of this is one of Object, 
                // int32, int64 and 2) this == 0 or this == null.
@@ -230,19 +319,48 @@ namespace Mono.CSharp {
                        get { return false; }
                }
 
+               public override void EmitSideEffect (EmitContext ec)
+               {
+                       // do nothing
+               }
+
+               public sealed override Expression Clone (CloneContext clonectx)
+               {
+                       // No cloning is not needed for constants
+                       return this;
+               }
+
                protected override void CloneTo (CloneContext clonectx, Expression target)
                {
-                       // CloneTo: Nothing, we do not keep any state on this expression
+                       throw new NotSupportedException ("should not be reached");
+               }
+
+               public override System.Linq.Expressions.Expression MakeExpression (BuilderContext ctx)
+               {
+#if STATIC
+                       return base.MakeExpression (ctx);
+#else
+                       return System.Linq.Expressions.Expression.Constant (GetTypedValue (), type.GetMetaInfo ());
+#endif
+               }
+
+               public new bool Resolve (ResolveContext rc)
+               {
+                       // It exists only as hint not to call Resolve on constants
+                       return true;
                }
        }
 
-       public abstract class IntegralConstant : Constant {
-               protected IntegralConstant (Location loc) :
-                       base (loc)
+       public abstract class IntegralConstant : Constant
+       {
+               protected IntegralConstant (TypeSpec type, Location loc)
+                       : base (loc)
                {
+                       this.type = type;
+                       eclass = ExprClass.Value;
                }
 
-               public override void Error_ValueCannotBeConverted (EmitContext ec, Location loc, Type target, bool expl)
+               public override void Error_ValueCannotBeConverted (ResolveContext ec, Location loc, TypeSpec target, bool expl)
                {
                        try {
                                ConvertExplicitly (true, target);
@@ -250,48 +368,64 @@ namespace Mono.CSharp {
                        }
                        catch
                        {
-                               Report.Error (31, loc, "Constant value `{0}' cannot be converted to a `{1}'",
+                               ec.Report.Error (31, loc, "Constant value `{0}' cannot be converted to a `{1}'",
                                        GetValue ().ToString (), TypeManager.CSharpName (target));
                        }
                }
+
+               public override string GetValueAsLiteral ()
+               {
+                       return GetValue ().ToString ();
+               }
+               
+               public abstract Constant Increment ();
        }
        
        public class BoolConstant : Constant {
                public readonly bool Value;
+
+               public BoolConstant (BuildinTypes types, bool val, Location loc)
+                       : this (types.Bool, val, loc)
+               {
+               }
                
-               public BoolConstant (bool val, Location loc):
-                       base (loc)
+               public BoolConstant (TypeSpec type, bool val, Location loc)
+                       base (loc)
                {
-                       type = TypeManager.bool_type;
                        eclass = ExprClass.Value;
+                       this.type = type;
 
                        Value = val;
                }
 
-               override public string AsString ()
+               public override object GetValue ()
+               {
+                       return (object) Value;
+               }
+
+               public override string GetValueAsLiteral ()
                {
                        return Value ? "true" : "false";
                }
 
-               public override object GetValue ()
+               public override long GetValueAsLong ()
                {
-                       return (object) Value;
+                       return Value ? 1 : 0;
+               }
+
+               public override void EncodeAttributeValue (IMemberContext rc, AttributeEncoder enc, TypeSpec targetType)
+               {
+                       enc.Encode (Value);
                }
-                               
                
                public override void Emit (EmitContext ec)
                {
                        if (Value)
-                               ec.ig.Emit (OpCodes.Ldc_I4_1);
+                               ec.Emit (OpCodes.Ldc_I4_1);
                        else
-                               ec.ig.Emit (OpCodes.Ldc_I4_0);
+                               ec.Emit (OpCodes.Ldc_I4_0);
                }
 
-               public override Constant Increment ()
-               {
-                       throw new NotSupportedException ();
-               }
-       
                public override bool IsDefaultValue {
                        get {
                                return !Value;
@@ -308,32 +442,36 @@ namespace Mono.CSharp {
                        get { return Value == false; }
                }
 
-               public override Constant ConvertExplicitly (bool in_checked_context, Type target_type)
+               public override Constant ConvertExplicitly (bool in_checked_context, TypeSpec target_type)
                {
                        return null;
                }
 
        }
 
-       public class ByteConstant : IntegralConstant {
+       public class ByteConstant : IntegralConstant
+       {
                public readonly byte Value;
 
-               public ByteConstant (byte v, Location loc):
-                       base (loc)
+               public ByteConstant (BuildinTypes types, byte v, Location loc)
+                       : this (types.Byte, v, loc)
+               {
+               }
+
+               public ByteConstant (TypeSpec type, byte v, Location loc)
+                       : base (type, loc)
                {
-                       type = TypeManager.byte_type;
-                       eclass = ExprClass.Value;
                        Value = v;
                }
 
-               public override void Emit (EmitContext ec)
+               public override void EncodeAttributeValue (IMemberContext rc, AttributeEncoder enc, TypeSpec targetType)
                {
-                       IntLiteral.EmitInt (ec.ig, Value);
+                       enc.Encode (Value);
                }
 
-               public override string AsString ()
+               public override void Emit (EmitContext ec)
                {
-                       return Value.ToString ();
+                       ec.EmitInt (Value);
                }
 
                public override object GetValue ()
@@ -341,9 +479,14 @@ namespace Mono.CSharp {
                        return Value;
                }
 
+               public override long GetValueAsLong ()
+               {
+                       return Value;
+               }
+
                public override Constant Increment ()
                {
-                       return new ByteConstant (checked ((byte)(Value + 1)), loc);
+                       return new ByteConstant (type, checked ((byte)(Value + 1)), loc);
                }
 
                public override bool IsDefaultValue {
@@ -352,6 +495,12 @@ namespace Mono.CSharp {
                        }
                }
 
+               public override bool IsOneInteger {
+                       get {
+                               return Value == 1;
+                       }
+               }               
+
                public override bool IsNegative {
                        get {
                                return false;
@@ -362,35 +511,36 @@ namespace Mono.CSharp {
                        get { return Value == 0; }
                }
 
-               public override Constant ConvertExplicitly (bool in_checked_context, Type target_type)
+               public override Constant ConvertExplicitly (bool in_checked_context, TypeSpec target_type)
                {
-                       if (target_type == TypeManager.sbyte_type) {
+                       switch (target_type.BuildinType) {
+                       case BuildinTypeSpec.Type.SByte:
                                if (in_checked_context){
                                        if (Value > SByte.MaxValue)
                                                throw new OverflowException ();
                                }
-                               return new SByteConstant ((sbyte) Value, Location);
-                       }
-                       if (target_type == TypeManager.short_type)
-                               return new ShortConstant ((short) Value, Location);
-                       if (target_type == TypeManager.ushort_type)
-                               return new UShortConstant ((ushort) Value, Location);
-                       if (target_type == TypeManager.int32_type)
-                               return new IntConstant ((int) Value, Location);
-                       if (target_type == TypeManager.uint32_type)
-                               return new UIntConstant ((uint) Value, Location);
-                       if (target_type == TypeManager.int64_type)
-                               return new LongConstant ((long) Value, Location);
-                       if (target_type == TypeManager.uint64_type)
-                               return new ULongConstant ((ulong) Value, Location);
-                       if (target_type == TypeManager.float_type)
-                               return new FloatConstant ((float) Value, Location);
-                       if (target_type == TypeManager.double_type)
-                               return new DoubleConstant ((double) Value, Location);
-                       if (target_type == TypeManager.char_type)
-                               return new CharConstant ((char) Value, Location);
-                       if (target_type == TypeManager.decimal_type)
-                               return new DecimalConstant ((decimal) Value, Location);
+                               return new SByteConstant (target_type, (sbyte) Value, Location);
+                       case BuildinTypeSpec.Type.Short:
+                               return new ShortConstant (target_type, (short) Value, Location);
+                       case BuildinTypeSpec.Type.UShort:
+                               return new UShortConstant (target_type, (ushort) Value, Location);
+                       case BuildinTypeSpec.Type.Int:
+                               return new IntConstant (target_type, (int) Value, Location);
+                       case BuildinTypeSpec.Type.UInt:
+                               return new UIntConstant (target_type, (uint) Value, Location);
+                       case BuildinTypeSpec.Type.Long:
+                               return new LongConstant (target_type, (long) Value, Location);
+                       case BuildinTypeSpec.Type.ULong:
+                               return new ULongConstant (target_type, (ulong) Value, Location);
+                       case BuildinTypeSpec.Type.Float:
+                               return new FloatConstant (target_type, (float) Value, Location);
+                       case BuildinTypeSpec.Type.Double:
+                               return new DoubleConstant (target_type, (double) Value, Location);
+                       case BuildinTypeSpec.Type.Char:
+                               return new CharConstant (target_type, (char) Value, Location);
+                       case BuildinTypeSpec.Type.Decimal:
+                               return new DecimalConstant (target_type, (decimal) Value, Location);
+                       }
 
                        return null;
                }
@@ -400,20 +550,31 @@ namespace Mono.CSharp {
        public class CharConstant : Constant {
                public readonly char Value;
 
-               public CharConstant (char v, Location loc):
-                       base (loc)
+               public CharConstant (BuildinTypes types, char v, Location loc)
+                       : this (types.Char, v, loc)
                {
-                       type = TypeManager.char_type;
+               }
+
+               public CharConstant (TypeSpec type, char v, Location loc)
+                       : base (loc)
+               {
+                       this.type = type;
                        eclass = ExprClass.Value;
+
                        Value = v;
                }
 
+               public override void EncodeAttributeValue (IMemberContext rc, AttributeEncoder enc, TypeSpec targetType)
+               {
+                       enc.Encode ((ushort) Value);
+               }
+
                public override void Emit (EmitContext ec)
                {
-                       IntLiteral.EmitInt (ec.ig, Value);
+                       ec.EmitInt (Value);
                }
 
-               static public string descape (char c)
+               static string descape (char c)
                {
                        switch (c){
                        case '\a':
@@ -442,21 +603,21 @@ namespace Mono.CSharp {
                        return c.ToString ();
                }
 
-               public override string AsString ()
+               public override object GetValue ()
                {
-                       return "\"" + descape (Value) + "\"";
+                       return Value;
                }
 
-               public override object GetValue ()
+               public override long GetValueAsLong ()
                {
                        return Value;
                }
 
-               public override Constant Increment ()
+               public override string GetValueAsLiteral ()
                {
-                       return new CharConstant (checked ((char)(Value + 1)), loc);
+                       return "\"" + descape (Value) + "\"";
                }
-               
+
                public override bool IsDefaultValue {
                        get {
                                return Value == 0;
@@ -473,68 +634,72 @@ namespace Mono.CSharp {
                        get { return Value == '\0'; }
                }
 
-               public override Constant ConvertExplicitly (bool in_checked_context, Type target_type)
+               public override Constant ConvertExplicitly (bool in_checked_context, TypeSpec target_type)
                {
-                       if (target_type == TypeManager.byte_type) {
-                               if (in_checked_context){
+                       switch (target_type.BuildinType) {
+                       case BuildinTypeSpec.Type.Byte:
+                               if (in_checked_context) {
                                        if (Value < Byte.MinValue || Value > Byte.MaxValue)
                                                throw new OverflowException ();
                                }
-                               return new ByteConstant ((byte) Value, Location);
-                       }
-                       if (target_type == TypeManager.sbyte_type) {
-                               if (in_checked_context){
+                               return new ByteConstant (target_type, (byte) Value, Location);
+                       case BuildinTypeSpec.Type.SByte:
+                               if (in_checked_context) {
                                        if (Value > SByte.MaxValue)
                                                throw new OverflowException ();
                                }
-                               return new SByteConstant ((sbyte) Value, Location);
-                       }
-                       if (target_type == TypeManager.short_type) {
-                               if (in_checked_context){
+                               return new SByteConstant (target_type, (sbyte) Value, Location);
+
+                       case BuildinTypeSpec.Type.Short:
+                               if (in_checked_context) {
                                        if (Value > Int16.MaxValue)
                                                throw new OverflowException ();
-                               }                                       
-                               return new ShortConstant ((short) Value, Location);
-                       }
-                       if (target_type == TypeManager.int32_type)
-                               return new IntConstant ((int) Value, Location);
-                       if (target_type == TypeManager.uint32_type)
-                               return new UIntConstant ((uint) Value, Location);
-                       if (target_type == TypeManager.int64_type)
-                               return new LongConstant ((long) Value, Location);
-                       if (target_type == TypeManager.uint64_type)
-                               return new ULongConstant ((ulong) Value, Location);
-                       if (target_type == TypeManager.float_type)
-                               return new FloatConstant ((float) Value, Location);
-                       if (target_type == TypeManager.double_type)
-                               return new DoubleConstant ((double) Value, Location);
-                       if (target_type == TypeManager.decimal_type)
-                               return new DecimalConstant ((decimal) Value, Location);
+                               }
+                               return new ShortConstant (target_type, (short) Value, Location);
+                       case BuildinTypeSpec.Type.Int:
+                               return new IntConstant (target_type, (int) Value, Location);
+                       case BuildinTypeSpec.Type.UInt:
+                               return new UIntConstant (target_type, (uint) Value, Location);
+                       case BuildinTypeSpec.Type.Long:
+                               return new LongConstant (target_type, (long) Value, Location);
+                       case BuildinTypeSpec.Type.ULong:
+                               return new ULongConstant (target_type, (ulong) Value, Location);
+                       case BuildinTypeSpec.Type.Float:
+                               return new FloatConstant (target_type, (float) Value, Location);
+                       case BuildinTypeSpec.Type.Double:
+                               return new DoubleConstant (target_type, (double) Value, Location);
+                       case BuildinTypeSpec.Type.Decimal:
+                               return new DecimalConstant (target_type, (decimal) Value, Location);
+                       }
 
                        return null;
                }
 
        }
 
-       public class SByteConstant : IntegralConstant {
+       public class SByteConstant : IntegralConstant
+       {
                public readonly sbyte Value;
 
-               public SByteConstant (sbyte v, Location loc):
-                       base (loc)
+               public SByteConstant (BuildinTypes types, sbyte v, Location loc)
+                       : this (types.SByte, v, loc)
+               {
+               }
+
+               public SByteConstant (TypeSpec type, sbyte v, Location loc)
+                       : base (type, loc)
                {
-                       type = TypeManager.sbyte_type;
-                       eclass = ExprClass.Value;
                        Value = v;
                }
 
-               public override void Emit (EmitContext ec)
+               public override void EncodeAttributeValue (IMemberContext rc, AttributeEncoder enc, TypeSpec targetType)
                {
-                       IntLiteral.EmitInt (ec.ig, Value);
+                       enc.Encode (Value);
                }
 
-               public override string AsString ()
+               public override void Emit (EmitContext ec)
                {
-                       return Value.ToString ();
+                       ec.EmitInt (Value);
                }
 
                public override object GetValue ()
@@ -542,9 +707,14 @@ namespace Mono.CSharp {
                        return Value;
                }
 
+               public override long GetValueAsLong ()
+               {
+                       return Value;
+               }
+
                public override Constant Increment ()
                {
-                   return new SByteConstant (checked((sbyte)(Value + 1)), loc);
+                   return new SByteConstant (type, checked((sbyte)(Value + 1)), loc);
                }
 
                public override bool IsDefaultValue {
@@ -559,47 +729,52 @@ namespace Mono.CSharp {
                        }
                }
                
+               public override bool IsOneInteger {
+                       get {
+                               return Value == 1;
+                       }
+               }               
+               
                public override bool IsZeroInteger {
                        get { return Value == 0; }
                }
 
-               public override Constant ConvertExplicitly (bool in_checked_context, Type target_type)
+               public override Constant ConvertExplicitly (bool in_checked_context, TypeSpec target_type)
                {
-                       if (target_type == TypeManager.byte_type) {
+                       switch (target_type.BuildinType) {
+                       case BuildinTypeSpec.Type.Byte:
                                if (in_checked_context && Value < 0)
                                        throw new OverflowException ();
-                               return new ByteConstant ((byte) Value, Location);
-                       }
-                       if (target_type == TypeManager.short_type)
-                               return new ShortConstant ((short) Value, Location);
-                       if (target_type == TypeManager.ushort_type) {
+                               return new ByteConstant (target_type, (byte) Value, Location);
+                       case BuildinTypeSpec.Type.Short:
+                               return new ShortConstant (target_type, (short) Value, Location);
+                       case BuildinTypeSpec.Type.UShort:
                                if (in_checked_context && Value < 0)
                                        throw new OverflowException ();
-                               return new UShortConstant ((ushort) Value, Location);
-                       } if (target_type == TypeManager.int32_type)
-                                 return new IntConstant ((int) Value, Location);
-                       if (target_type == TypeManager.uint32_type) {
+                               return new UShortConstant (target_type, (ushort) Value, Location);
+                       case BuildinTypeSpec.Type.Int:
+                               return new IntConstant (target_type, (int) Value, Location);
+                       case BuildinTypeSpec.Type.UInt:
                                if (in_checked_context && Value < 0)
                                        throw new OverflowException ();
-                               return new UIntConstant ((uint) Value, Location);
-                       } if (target_type == TypeManager.int64_type)
-                                 return new LongConstant ((long) Value, Location);
-                       if (target_type == TypeManager.uint64_type) {
+                               return new UIntConstant (target_type, (uint) Value, Location);
+                       case BuildinTypeSpec.Type.Long:
+                               return new LongConstant (target_type, (long) Value, Location);
+                       case BuildinTypeSpec.Type.ULong:
                                if (in_checked_context && Value < 0)
                                        throw new OverflowException ();
-                               return new ULongConstant ((ulong) Value, Location);
-                       }
-                       if (target_type == TypeManager.float_type)
-                               return new FloatConstant ((float) Value, Location);
-                       if (target_type == TypeManager.double_type)
-                               return new DoubleConstant ((double) Value, Location);
-                       if (target_type == TypeManager.char_type) {
+                               return new ULongConstant (target_type, (ulong) Value, Location);
+                       case BuildinTypeSpec.Type.Float:
+                               return new FloatConstant (target_type, (float) Value, Location);
+                       case BuildinTypeSpec.Type.Double:
+                               return new DoubleConstant (target_type, (double) Value, Location);
+                       case BuildinTypeSpec.Type.Char:
                                if (in_checked_context && Value < 0)
                                        throw new OverflowException ();
-                               return new CharConstant ((char) Value, Location);
+                               return new CharConstant (target_type, (char) Value, Location);
+                       case BuildinTypeSpec.Type.Decimal:
+                               return new DecimalConstant (target_type, (decimal) Value, Location);
                        }
-                       if (target_type == TypeManager.decimal_type)
-                               return new DecimalConstant ((decimal) Value, Location);
 
                        return null;
                }
@@ -609,22 +784,25 @@ namespace Mono.CSharp {
        public class ShortConstant : IntegralConstant {
                public readonly short Value;
 
-               public ShortConstant (short v, Location loc):
-                       base (loc)
+               public ShortConstant (BuildinTypes types, short v, Location loc)
+                       : this (types.Short, v, loc)
+               {
+               }
+
+               public ShortConstant (TypeSpec type, short v, Location loc)
+                       : base (type, loc)
                {
-                       type = TypeManager.short_type;
-                       eclass = ExprClass.Value;
                        Value = v;
                }
 
-               public override void Emit (EmitContext ec)
+               public override void EncodeAttributeValue (IMemberContext rc, AttributeEncoder enc, TypeSpec targetType)
                {
-                       IntLiteral.EmitInt (ec.ig, Value);
+                       enc.Encode (Value);
                }
 
-               public override string AsString ()
+               public override void Emit (EmitContext ec)
                {
-                       return Value.ToString ();
+                       ec.EmitInt (Value);
                }
 
                public override object GetValue ()
@@ -632,9 +810,14 @@ namespace Mono.CSharp {
                        return Value;
                }
 
+               public override long GetValueAsLong ()
+               {
+                       return Value;
+               }
+
                public override Constant Increment ()
                {
-                       return new ShortConstant (checked((short)(Value + 1)), loc);
+                       return new ShortConstant (type, checked((short)(Value + 1)), loc);
                }
 
                public override bool IsDefaultValue {
@@ -652,91 +835,102 @@ namespace Mono.CSharp {
                                return Value < 0;
                        }
                }
+               
+               public override bool IsOneInteger {
+                       get {
+                               return Value == 1;
+                       }
+               }               
 
-               public override Constant ConvertExplicitly (bool in_checked_context, Type target_type)
+               public override Constant ConvertExplicitly (bool in_checked_context, TypeSpec target_type)
                {
-                       if (target_type == TypeManager.byte_type) {
-                               if (in_checked_context){
+                       switch (target_type.BuildinType) {
+                       case BuildinTypeSpec.Type.Byte:
+                               if (in_checked_context) {
                                        if (Value < Byte.MinValue || Value > Byte.MaxValue)
                                                throw new OverflowException ();
                                }
-                               return new ByteConstant ((byte) Value, Location);
-                       }
-                       if (target_type == TypeManager.sbyte_type) {
-                               if (in_checked_context){
+                               return new ByteConstant (target_type, (byte) Value, Location);
+                       case BuildinTypeSpec.Type.SByte:
+                               if (in_checked_context) {
                                        if (Value < SByte.MinValue || Value > SByte.MaxValue)
                                                throw new OverflowException ();
                                }
-                               return new SByteConstant ((sbyte) Value, Location);
-                       }
-                       if (target_type == TypeManager.ushort_type) {
+                               return new SByteConstant (target_type, (sbyte) Value, Location);
+                       case BuildinTypeSpec.Type.UShort:
                                if (in_checked_context && Value < 0)
                                        throw new OverflowException ();
-                               
-                               return new UShortConstant ((ushort) Value, Location);
-                       }
-                       if (target_type == TypeManager.int32_type)
-                               return new IntConstant ((int) Value, Location);
-                       if (target_type == TypeManager.uint32_type) {
+
+                               return new UShortConstant (target_type, (ushort) Value, Location);
+                       case BuildinTypeSpec.Type.Int:
+                               return new IntConstant (target_type, (int) Value, Location);
+                       case BuildinTypeSpec.Type.UInt:
                                if (in_checked_context && Value < 0)
                                        throw new OverflowException ();
-                               return new UIntConstant ((uint) Value, Location);
-                       }
-                       if (target_type == TypeManager.int64_type)
-                               return new LongConstant ((long) Value, Location);
-                       if (target_type == TypeManager.uint64_type) {
+                               return new UIntConstant (target_type, (uint) Value, Location);
+                       case BuildinTypeSpec.Type.Long:
+                               return new LongConstant (target_type, (long) Value, Location);
+                       case BuildinTypeSpec.Type.ULong:
                                if (in_checked_context && Value < 0)
                                        throw new OverflowException ();
-                               return new ULongConstant ((ulong) Value, Location);
-                       }
-                       if (target_type == TypeManager.float_type)
-                               return new FloatConstant ((float) Value, Location);
-                       if (target_type == TypeManager.double_type)
-                               return new DoubleConstant ((double) Value, Location);
-                       if (target_type == TypeManager.char_type) {
-                               if (in_checked_context){
+                               return new ULongConstant (target_type, (ulong) Value, Location);
+                       case BuildinTypeSpec.Type.Float:
+                               return new FloatConstant (target_type, (float) Value, Location);
+                       case BuildinTypeSpec.Type.Double:
+                               return new DoubleConstant (target_type, (double) Value, Location);
+                       case BuildinTypeSpec.Type.Char:
+                               if (in_checked_context) {
                                        if (Value < Char.MinValue)
                                                throw new OverflowException ();
                                }
-                               return new CharConstant ((char) Value, Location);
+                               return new CharConstant (target_type, (char) Value, Location);
+                       case BuildinTypeSpec.Type.Decimal:
+                               return new DecimalConstant (target_type, (decimal) Value, Location);
                        }
-                       if (target_type == TypeManager.decimal_type)
-                               return new DecimalConstant ((decimal) Value, Location);
 
                        return null;
                }
 
        }
 
-       public class UShortConstant : IntegralConstant {
+       public class UShortConstant : IntegralConstant
+       {
                public readonly ushort Value;
 
-               public UShortConstant (ushort v, Location loc):
-                       base (loc)
+               public UShortConstant (BuildinTypes types, ushort v, Location loc)
+                       : this (types.UShort, v, loc)
+               {
+               }
+
+               public UShortConstant (TypeSpec type, ushort v, Location loc)
+                       : base (type, loc)
                {
-                       type = TypeManager.ushort_type;
-                       eclass = ExprClass.Value;
                        Value = v;
                }
 
-               public override void Emit (EmitContext ec)
+               public override void EncodeAttributeValue (IMemberContext rc, AttributeEncoder enc, TypeSpec targetType)
                {
-                       IntLiteral.EmitInt (ec.ig, Value);
+                       enc.Encode (Value);
                }
 
-               public override string AsString ()
+               public override void Emit (EmitContext ec)
                {
-                       return Value.ToString ();
+                       ec.EmitInt (Value);
                }
 
                public override object GetValue ()
                {
                        return Value;
                }
+
+               public override long GetValueAsLong ()
+               {
+                       return Value;
+               }
        
                public override Constant Increment ()
                {
-                       return new UShortConstant (checked((ushort)(Value + 1)), loc);
+                       return new UShortConstant (type, checked((ushort)(Value + 1)), loc);
                }
 
                public override bool IsDefaultValue {
@@ -750,141 +944,102 @@ namespace Mono.CSharp {
                                return false;
                        }
                }
+               
+               public override bool IsOneInteger {
+                       get {
+                               return Value == 1;
+                       }
+               }               
        
                public override bool IsZeroInteger {
                        get { return Value == 0; }
                }
 
-               public override Constant ConvertExplicitly (bool in_checked_context, Type target_type)
+               public override Constant ConvertExplicitly (bool in_checked_context, TypeSpec target_type)
                {
-                       if (target_type == TypeManager.byte_type) {
-                               if (in_checked_context){
+                       switch (target_type.BuildinType) {
+                       case BuildinTypeSpec.Type.Byte:
+                               if (in_checked_context) {
                                        if (Value > Byte.MaxValue)
                                                throw new OverflowException ();
                                }
-                               return new ByteConstant ((byte) Value, Location);
-                       }
-                       if (target_type == TypeManager.sbyte_type) {
-                               if (in_checked_context){
+                               return new ByteConstant (target_type, (byte) Value, Location);
+                       case BuildinTypeSpec.Type.SByte:
+                               if (in_checked_context) {
                                        if (Value > SByte.MaxValue)
                                                throw new OverflowException ();
                                }
-                               return new SByteConstant ((sbyte) Value, Location);
-                       }
-                       if (target_type == TypeManager.short_type) {
-                               if (in_checked_context){
+                               return new SByteConstant (target_type, (sbyte) Value, Location);
+                       case BuildinTypeSpec.Type.Short:
+                               if (in_checked_context) {
                                        if (Value > Int16.MaxValue)
                                                throw new OverflowException ();
                                }
-                               return new ShortConstant ((short) Value, Location);
-                       }
-                       if (target_type == TypeManager.int32_type)
-                               return new IntConstant ((int) Value, Location);
-                       if (target_type == TypeManager.uint32_type)
-                               return new UIntConstant ((uint) Value, Location);
-                       if (target_type == TypeManager.int64_type)
-                               return new LongConstant ((long) Value, Location);
-                       if (target_type == TypeManager.uint64_type)
-                               return new ULongConstant ((ulong) Value, Location);
-                       if (target_type == TypeManager.float_type)
-                               return new FloatConstant ((float) Value, Location);
-                       if (target_type == TypeManager.double_type)
-                               return new DoubleConstant ((double) Value, Location);
-                       if (target_type == TypeManager.char_type) {
-                               if (in_checked_context){
+                               return new ShortConstant (target_type, (short) Value, Location);
+                       case BuildinTypeSpec.Type.Int:
+                               return new IntConstant (target_type, (int) Value, Location);
+                       case BuildinTypeSpec.Type.UInt:
+                               return new UIntConstant (target_type, (uint) Value, Location);
+                       case BuildinTypeSpec.Type.Long:
+                               return new LongConstant (target_type, (long) Value, Location);
+                       case BuildinTypeSpec.Type.ULong:
+                               return new ULongConstant (target_type, (ulong) Value, Location);
+                       case BuildinTypeSpec.Type.Float:
+                               return new FloatConstant (target_type, (float) Value, Location);
+                       case BuildinTypeSpec.Type.Double:
+                               return new DoubleConstant (target_type, (double) Value, Location);
+                       case BuildinTypeSpec.Type.Char:
+                               if (in_checked_context) {
                                        if (Value > Char.MaxValue)
                                                throw new OverflowException ();
                                }
-                               return new CharConstant ((char) Value, Location);
+                               return new CharConstant (target_type, (char) Value, Location);
+                       case BuildinTypeSpec.Type.Decimal:
+                               return new DecimalConstant (target_type, (decimal) Value, Location);
                        }
-                       if (target_type == TypeManager.decimal_type)
-                               return new DecimalConstant ((decimal) Value, Location);
 
                        return null;
                }
        }
 
-       public class IntConstant : IntegralConstant {
+       public class IntConstant : IntegralConstant
+       {
                public readonly int Value;
 
-               public IntConstant (int v, Location loc):
-                       base (loc)
+               public IntConstant (BuildinTypes types, int v, Location loc)
+                       : this (types.Int, v, loc)
                {
-                       type = TypeManager.int32_type;
-                       eclass = ExprClass.Value;
-                       Value = v;
                }
 
-               static public void EmitInt (ILGenerator ig, int i)
+               public IntConstant (TypeSpec type, int v, Location loc)
+                       : base (type, loc)
                {
-                       switch (i){
-                       case -1:
-                               ig.Emit (OpCodes.Ldc_I4_M1);
-                               break;
-                               
-                       case 0:
-                               ig.Emit (OpCodes.Ldc_I4_0);
-                               break;
-                               
-                       case 1:
-                               ig.Emit (OpCodes.Ldc_I4_1);
-                               break;
-                               
-                       case 2:
-                               ig.Emit (OpCodes.Ldc_I4_2);
-                               break;
-                               
-                       case 3:
-                               ig.Emit (OpCodes.Ldc_I4_3);
-                               break;
-                               
-                       case 4:
-                               ig.Emit (OpCodes.Ldc_I4_4);
-                               break;
-                               
-                       case 5:
-                               ig.Emit (OpCodes.Ldc_I4_5);
-                               break;
-                               
-                       case 6:
-                               ig.Emit (OpCodes.Ldc_I4_6);
-                               break;
-                               
-                       case 7:
-                               ig.Emit (OpCodes.Ldc_I4_7);
-                               break;
-                               
-                       case 8:
-                               ig.Emit (OpCodes.Ldc_I4_8);
-                               break;
+                       Value = v;
+               }
 
-                       default:
-                               if (i >= -128 && i <= 127){
-                                       ig.Emit (OpCodes.Ldc_I4_S, (sbyte) i);
-                               } else
-                                       ig.Emit (OpCodes.Ldc_I4, i);
-                               break;
-                       }
+               public override void EncodeAttributeValue (IMemberContext rc, AttributeEncoder enc, TypeSpec targetType)
+               {
+                       enc.Encode (Value);
                }
 
                public override void Emit (EmitContext ec)
                {
-                       EmitInt (ec.ig, Value);
+                       ec.EmitInt (Value);
                }
 
-               public override string AsString ()
+               public override object GetValue ()
                {
-                       return Value.ToString ();
+                       return Value;
                }
 
-               public override object GetValue ()
+               public override long GetValueAsLong ()
                {
                        return Value;
                }
 
                public override Constant Increment ()
                {
-                       return new IntConstant (checked(Value + 1), loc);
+                       return new IntConstant (type, checked(Value + 1), loc);
                }
 
                public override bool IsDefaultValue {
@@ -898,80 +1053,81 @@ namespace Mono.CSharp {
                                return Value < 0;
                        }
                }
+               
+               public override bool IsOneInteger {
+                       get {
+                               return Value == 1;
+                       }
+               }               
 
                public override bool IsZeroInteger {
                        get { return Value == 0; }
                }
 
-               public override Constant ConvertExplicitly (bool in_checked_context, Type target_type)
+               public override Constant ConvertExplicitly (bool in_checked_context, TypeSpec target_type)
                {
-                       if (target_type == TypeManager.byte_type) {
-                               if (in_checked_context){
+                       switch (target_type.BuildinType) {
+                       case BuildinTypeSpec.Type.Byte:
+                               if (in_checked_context) {
                                        if (Value < Byte.MinValue || Value > Byte.MaxValue)
                                                throw new OverflowException ();
                                }
-                               return new ByteConstant ((byte) Value, Location);
-                       }
-                       if (target_type == TypeManager.sbyte_type) {
-                               if (in_checked_context){
+                               return new ByteConstant (target_type, (byte) Value, Location);
+                       case BuildinTypeSpec.Type.SByte:
+                               if (in_checked_context) {
                                        if (Value < SByte.MinValue || Value > SByte.MaxValue)
                                                throw new OverflowException ();
                                }
-                               return new SByteConstant ((sbyte) Value, Location);
-                       }
-                       if (target_type == TypeManager.short_type) {
-                               if (in_checked_context){
+                               return new SByteConstant (target_type, (sbyte) Value, Location);
+                       case BuildinTypeSpec.Type.Short:
+                               if (in_checked_context) {
                                        if (Value < Int16.MinValue || Value > Int16.MaxValue)
                                                throw new OverflowException ();
                                }
-                               return new ShortConstant ((short) Value, Location);
-                       }
-                       if (target_type == TypeManager.ushort_type) {
-                               if (in_checked_context){
+                               return new ShortConstant (target_type, (short) Value, Location);
+                       case BuildinTypeSpec.Type.UShort:
+                               if (in_checked_context) {
                                        if (Value < UInt16.MinValue || Value > UInt16.MaxValue)
                                                throw new OverflowException ();
                                }
-                               return new UShortConstant ((ushort) Value, Location);
-                       }
-                       if (target_type == TypeManager.uint32_type) {
-                               if (in_checked_context){
+                               return new UShortConstant (target_type, (ushort) Value, Location);
+                       case BuildinTypeSpec.Type.UInt:
+                               if (in_checked_context) {
                                        if (Value < UInt32.MinValue)
                                                throw new OverflowException ();
                                }
-                               return new UIntConstant ((uint) Value, Location);
-                       }
-                       if (target_type == TypeManager.int64_type)
-                               return new LongConstant ((long) Value, Location);
-                       if (target_type == TypeManager.uint64_type) {
+                               return new UIntConstant (target_type, (uint) Value, Location);
+                       case BuildinTypeSpec.Type.Long:
+                               return new LongConstant (target_type, (long) Value, Location);
+                       case BuildinTypeSpec.Type.ULong:
                                if (in_checked_context && Value < 0)
                                        throw new OverflowException ();
-                               return new ULongConstant ((ulong) Value, Location);
-                       }
-                       if (target_type == TypeManager.float_type)
-                               return new FloatConstant ((float) Value, Location);
-                       if (target_type == TypeManager.double_type)
-                               return new DoubleConstant ((double) Value, Location);
-                       if (target_type == TypeManager.char_type) {
-                               if (in_checked_context){
+                               return new ULongConstant (target_type, (ulong) Value, Location);
+                       case BuildinTypeSpec.Type.Float:
+                               return new FloatConstant (target_type, (float) Value, Location);
+                       case BuildinTypeSpec.Type.Double:
+                               return new DoubleConstant (target_type, (double) Value, Location);
+                       case BuildinTypeSpec.Type.Char:
+                               if (in_checked_context) {
                                        if (Value < Char.MinValue || Value > Char.MaxValue)
                                                throw new OverflowException ();
                                }
-                               return new CharConstant ((char) Value, Location);
+                               return new CharConstant (target_type, (char) Value, Location);
+                       case BuildinTypeSpec.Type.Decimal:
+                               return new DecimalConstant (target_type, (decimal) Value, Location);
                        }
-                       if (target_type == TypeManager.decimal_type)
-                               return new DecimalConstant ((decimal) Value, Location);
 
                        return null;
                }
 
-               public override Constant ConvertImplicitly (Type type)
+               public override Constant ConvertImplicitly (TypeSpec type)
                {
                        if (this.type == type)
                                return this;
 
                        Constant c = TryImplicitIntConversion (type);
                        if (c != null)
-                               return c;
+                               return c; //.Resolve (rc);
 
                        return base.ConvertImplicitly (type);
                }
@@ -981,41 +1137,43 @@ namespace Mono.CSharp {
                ///   into a different data type using casts (See Implicit Constant
                ///   Expression Conversions)
                /// </summary>
-               Constant TryImplicitIntConversion (Type target_type)
+               Constant TryImplicitIntConversion (TypeSpec target_type)
                {
-                       if (target_type == TypeManager.sbyte_type) {
+                       switch (target_type.BuildinType) {
+                       case BuildinTypeSpec.Type.SByte:
                                if (Value >= SByte.MinValue && Value <= SByte.MaxValue)
-                                       return new SByteConstant ((sbyte) Value, loc);
-                       } 
-                       else if (target_type == TypeManager.byte_type) {
+                                       return new SByteConstant (target_type, (sbyte) Value, loc);
+                               break;
+                       case BuildinTypeSpec.Type.Byte:
                                if (Value >= Byte.MinValue && Value <= Byte.MaxValue)
-                                       return new ByteConstant ((byte) Value, loc);
-                       } 
-                       else if (target_type == TypeManager.short_type) {
+                                       return new ByteConstant (target_type, (byte) Value, loc);
+                               break;
+                       case BuildinTypeSpec.Type.Short:
                                if (Value >= Int16.MinValue && Value <= Int16.MaxValue)
-                                       return new ShortConstant ((short) Value, loc);
-                       } 
-                       else if (target_type == TypeManager.ushort_type) {
+                                       return new ShortConstant (target_type, (short) Value, loc);
+                               break;
+                       case BuildinTypeSpec.Type.UShort:
                                if (Value >= UInt16.MinValue && Value <= UInt16.MaxValue)
-                                       return new UShortConstant ((ushort) Value, loc);
-                       } 
-                       else if (target_type == TypeManager.uint32_type) {
+                                       return new UShortConstant (target_type, (ushort) Value, loc);
+                               break;
+                       case BuildinTypeSpec.Type.UInt:
                                if (Value >= 0)
-                                       return new UIntConstant ((uint) Value, loc);
-                       } 
-                       else if (target_type == TypeManager.uint64_type) {
+                                       return new UIntConstant (target_type, (uint) Value, loc);
+                               break;
+                       case BuildinTypeSpec.Type.ULong:
                                //
                                // we can optimize this case: a positive int32
                                // always fits on a uint64.  But we need an opcode
                                // to do it.
                                //
                                if (Value >= 0)
-                                       return new ULongConstant ((ulong) Value, loc);
-                       } 
-                       else if (target_type == TypeManager.double_type)
-                               return new DoubleConstant ((double) Value, loc);
-                       else if (target_type == TypeManager.float_type)
-                               return new FloatConstant ((float) Value, loc);
+                                       return new ULongConstant (target_type, (ulong) Value, loc);
+                               break;
+                       case BuildinTypeSpec.Type.Double:
+                               return new DoubleConstant (target_type, (double) Value, loc);
+                       case BuildinTypeSpec.Type.Float:
+                               return new FloatConstant (target_type, (float) Value, loc);
+                       }
 
                        return null;
                }
@@ -1024,22 +1182,25 @@ namespace Mono.CSharp {
        public class UIntConstant : IntegralConstant {
                public readonly uint Value;
 
-               public UIntConstant (uint v, Location loc):
-                       base (loc)
+               public UIntConstant (BuildinTypes types, uint v, Location loc)
+                       : this (types.UInt, v, loc)
+               {
+               }
+
+               public UIntConstant (TypeSpec type, uint v, Location loc)
+                       : base (type, loc)
                {
-                       type = TypeManager.uint32_type;
-                       eclass = ExprClass.Value;
                        Value = v;
                }
 
-               public override void Emit (EmitContext ec)
+               public override void EncodeAttributeValue (IMemberContext rc, AttributeEncoder enc, TypeSpec targetType)
                {
-                       IntLiteral.EmitInt (ec.ig, unchecked ((int) Value));
+                       enc.Encode (Value);
                }
 
-               public override string AsString ()
+               public override void Emit (EmitContext ec)
                {
-                       return Value.ToString ();
+                       ec.EmitInt (unchecked ((int) Value));
                }
 
                public override object GetValue ()
@@ -1047,9 +1208,14 @@ namespace Mono.CSharp {
                        return Value;
                }
 
+               public override long GetValueAsLong ()
+               {
+                       return Value;
+               }
+
                public override Constant Increment ()
                {
-                       return new UIntConstant (checked(Value + 1), loc);
+                       return new UIntConstant (type, checked(Value + 1), loc);
                }
        
                public override bool IsDefaultValue {
@@ -1063,65 +1229,67 @@ namespace Mono.CSharp {
                                return false;
                        }
                }
+               
+               public override bool IsOneInteger {
+                       get {
+                               return Value == 1;
+                       }
+               }               
 
                public override bool IsZeroInteger {
                        get { return Value == 0; }
                }
 
-               public override Constant ConvertExplicitly (bool in_checked_context, Type target_type)
+               public override Constant ConvertExplicitly (bool in_checked_context, TypeSpec target_type)
                {
-                       if (target_type == TypeManager.byte_type) {
-                               if (in_checked_context){
-                                       if (Value < Char.MinValue || Value > Char.MaxValue)
+                       switch (target_type.BuildinType) {
+                       case BuildinTypeSpec.Type.Byte:
+                               if (in_checked_context) {
+                                       if (Value < 0 || Value > byte.MaxValue)
                                                throw new OverflowException ();
                                }
-                               return new ByteConstant ((byte) Value, Location);
-                       }
-                       if (target_type == TypeManager.sbyte_type) {
-                               if (in_checked_context){
+                               return new ByteConstant (target_type, (byte) Value, Location);
+                       case BuildinTypeSpec.Type.SByte:
+                               if (in_checked_context) {
                                        if (Value > SByte.MaxValue)
                                                throw new OverflowException ();
                                }
-                               return new SByteConstant ((sbyte) Value, Location);
-                       }
-                       if (target_type == TypeManager.short_type) {
-                               if (in_checked_context){
+                               return new SByteConstant (target_type, (sbyte) Value, Location);
+                       case BuildinTypeSpec.Type.Short:
+                               if (in_checked_context) {
                                        if (Value > Int16.MaxValue)
                                                throw new OverflowException ();
                                }
-                               return new ShortConstant ((short) Value, Location);
-                       }
-                       if (target_type == TypeManager.ushort_type) {
-                               if (in_checked_context){
+                               return new ShortConstant (target_type, (short) Value, Location);
+                       case BuildinTypeSpec.Type.UShort:
+                               if (in_checked_context) {
                                        if (Value < UInt16.MinValue || Value > UInt16.MaxValue)
                                                throw new OverflowException ();
                                }
-                               return new UShortConstant ((ushort) Value, Location);
-                       }
-                       if (target_type == TypeManager.int32_type) {
-                               if (in_checked_context){
+                               return new UShortConstant (target_type, (ushort) Value, Location);
+                       case BuildinTypeSpec.Type.Int:
+                               if (in_checked_context) {
                                        if (Value > Int32.MaxValue)
                                                throw new OverflowException ();
                                }
-                               return new IntConstant ((int) Value, Location);
-                       }
-                       if (target_type == TypeManager.int64_type)
-                               return new LongConstant ((long) Value, Location);
-                       if (target_type == TypeManager.uint64_type)
-                               return new ULongConstant ((ulong) Value, Location);
-                       if (target_type == TypeManager.float_type)
-                               return new FloatConstant ((float) Value, Location);
-                       if (target_type == TypeManager.double_type)
-                               return new DoubleConstant ((double) Value, Location);
-                       if (target_type == TypeManager.char_type) {
-                               if (in_checked_context){
+                               return new IntConstant (target_type, (int) Value, Location);
+                       case BuildinTypeSpec.Type.Long:
+                               return new LongConstant (target_type, (long) Value, Location);
+                       case BuildinTypeSpec.Type.ULong:
+                               return new ULongConstant (target_type, (ulong) Value, Location);
+                       case BuildinTypeSpec.Type.Float:
+                               return new FloatConstant (target_type, (float) Value, Location);
+                       case BuildinTypeSpec.Type.Double:
+                               return new DoubleConstant (target_type, (double) Value, Location);
+                       case BuildinTypeSpec.Type.Char:
+                               if (in_checked_context) {
                                        if (Value < Char.MinValue || Value > Char.MaxValue)
                                                throw new OverflowException ();
                                }
-                               return new CharConstant ((char) Value, Location);
+                               return new CharConstant (target_type, (char) Value, Location);
+                       case BuildinTypeSpec.Type.Decimal:
+                               return new DecimalConstant (target_type, (decimal) Value, Location);
                        }
-                       if (target_type == TypeManager.decimal_type)
-                               return new DecimalConstant ((decimal) Value, Location);
 
                        return null;
                }
@@ -1131,32 +1299,25 @@ namespace Mono.CSharp {
        public class LongConstant : IntegralConstant {
                public readonly long Value;
 
-               public LongConstant (long v, Location loc):
-                       base (loc)
+               public LongConstant (BuildinTypes types, long v, Location loc)
+                       : this (types.Long, v, loc)
                {
-                       type = TypeManager.int64_type;
-                       eclass = ExprClass.Value;
-                       Value = v;
                }
 
-               public override void Emit (EmitContext ec)
+               public LongConstant (TypeSpec type, long v, Location loc)
+                       : base (type, loc)
                {
-                       EmitLong (ec.ig, Value);
+                       Value = v;
                }
 
-               static public void EmitLong (ILGenerator ig, long l)
+               public override void EncodeAttributeValue (IMemberContext rc, AttributeEncoder enc, TypeSpec targetType)
                {
-                       if (l >= int.MinValue && l <= int.MaxValue) {
-                               IntLiteral.EmitInt (ig, unchecked ((int) l));
-                               ig.Emit (OpCodes.Conv_I8);
-                               return;
-                       }
-                       ig.Emit (OpCodes.Ldc_I8, l);
+                       enc.Encode (Value);
                }
 
-               public override string AsString ()
+               public override void Emit (EmitContext ec)
                {
-                       return Value.ToString ();
+                       ec.EmitLong (Value);
                }
 
                public override object GetValue ()
@@ -1164,9 +1325,14 @@ namespace Mono.CSharp {
                        return Value;
                }
 
+               public override long GetValueAsLong ()
+               {
+                       return Value;
+               }
+
                public override Constant Increment ()
                {
-                       return new LongConstant (checked(Value + 1), loc);
+                       return new LongConstant (type, checked(Value + 1), loc);
                }
                
                public override bool IsDefaultValue {
@@ -1180,81 +1346,81 @@ namespace Mono.CSharp {
                                return Value < 0;
                        }
                }
+               
+               public override bool IsOneInteger {
+                       get {
+                               return Value == 1;
+                       }
+               }               
 
                public override bool IsZeroInteger {
                        get { return Value == 0; }
                }
 
-               public override Constant ConvertExplicitly (bool in_checked_context, Type target_type)
+               public override Constant ConvertExplicitly (bool in_checked_context, TypeSpec target_type)
                {
-                       if (target_type == TypeManager.byte_type) {
-                               if (in_checked_context){
+                       switch (target_type.BuildinType) {
+                       case BuildinTypeSpec.Type.Byte:
+                               if (in_checked_context) {
                                        if (Value < Byte.MinValue || Value > Byte.MaxValue)
                                                throw new OverflowException ();
                                }
-                               return new ByteConstant ((byte) Value, Location);
-                       }
-                       if (target_type == TypeManager.sbyte_type) {
-                               if (in_checked_context){
+                               return new ByteConstant (target_type, (byte) Value, Location);
+                       case BuildinTypeSpec.Type.SByte:
+                               if (in_checked_context) {
                                        if (Value < SByte.MinValue || Value > SByte.MaxValue)
                                                throw new OverflowException ();
                                }
-                               return new SByteConstant ((sbyte) Value, Location);
-                       }
-                       if (target_type == TypeManager.short_type) {
-                               if (in_checked_context){
+                               return new SByteConstant (target_type, (sbyte) Value, Location);
+                       case BuildinTypeSpec.Type.Short:
+                               if (in_checked_context) {
                                        if (Value < Int16.MinValue || Value > Int16.MaxValue)
                                                throw new OverflowException ();
                                }
-                               return new ShortConstant ((short) Value, Location);
-                       }
-                       if (target_type == TypeManager.ushort_type) {
-                               if (in_checked_context){
+                               return new ShortConstant (target_type, (short) Value, Location);
+                       case BuildinTypeSpec.Type.UShort:
+                               if (in_checked_context) {
                                        if (Value < UInt16.MinValue || Value > UInt16.MaxValue)
                                                throw new OverflowException ();
                                }
-                               return new UShortConstant ((ushort) Value, Location);
-                       }
-                       if (target_type == TypeManager.int32_type) {
-                               if (in_checked_context){
+                               return new UShortConstant (target_type, (ushort) Value, Location);
+                       case BuildinTypeSpec.Type.Int:
+                               if (in_checked_context) {
                                        if (Value < Int32.MinValue || Value > Int32.MaxValue)
                                                throw new OverflowException ();
                                }
-                               return new IntConstant ((int) Value, Location);
-                       }
-                       if (target_type == TypeManager.uint32_type) {
-                               if (in_checked_context){
+                               return new IntConstant (target_type, (int) Value, Location);
+                       case BuildinTypeSpec.Type.UInt:
+                               if (in_checked_context) {
                                        if (Value < UInt32.MinValue || Value > UInt32.MaxValue)
                                                throw new OverflowException ();
                                }
-                               return new UIntConstant ((uint) Value, Location);
-                       }
-                       if (target_type == TypeManager.uint64_type) {
+                               return new UIntConstant (target_type, (uint) Value, Location);
+                       case BuildinTypeSpec.Type.ULong:
                                if (in_checked_context && Value < 0)
                                        throw new OverflowException ();
-                               return new ULongConstant ((ulong) Value, Location);
-                       }
-                       if (target_type == TypeManager.float_type)
-                               return new FloatConstant ((float) Value, Location);
-                       if (target_type == TypeManager.double_type)
-                               return new DoubleConstant ((double) Value, Location);
-                       if (target_type == TypeManager.char_type) {
-                               if (in_checked_context){
+                               return new ULongConstant (target_type, (ulong) Value, Location);
+                       case BuildinTypeSpec.Type.Float:
+                               return new FloatConstant (target_type, (float) Value, Location);
+                       case BuildinTypeSpec.Type.Double:
+                               return new DoubleConstant (target_type, (double) Value, Location);
+                       case BuildinTypeSpec.Type.Char:
+                               if (in_checked_context) {
                                        if (Value < Char.MinValue || Value > Char.MaxValue)
                                                throw new OverflowException ();
                                }
-                               return new CharConstant ((char) Value, Location);
+                               return new CharConstant (target_type, (char) Value, Location);
+                       case BuildinTypeSpec.Type.Decimal:
+                               return new DecimalConstant (target_type, (decimal) Value, Location);
                        }
-                       if (target_type == TypeManager.decimal_type)
-                               return new DecimalConstant ((decimal) Value, Location);
 
                        return null;
                }
 
-               public override Constant ConvertImplicitly (Type type)
+               public override Constant ConvertImplicitly (TypeSpec type)
                {
-                       if (Value >= 0 && type == TypeManager.uint64_type) {
-                               return new ULongConstant ((ulong) Value, loc);
+                       if (Value >= 0 && type.BuildinType == BuildinTypeSpec.Type.ULong) {
+                               return new ULongConstant (type, (ulong) Value, loc);
                        }
 
                        return base.ConvertImplicitly (type);
@@ -1264,24 +1430,25 @@ namespace Mono.CSharp {
        public class ULongConstant : IntegralConstant {
                public readonly ulong Value;
 
-               public ULongConstant (ulong v, Location loc):
-                       base (loc)
+               public ULongConstant (BuildinTypes types, ulong v, Location loc)
+                       : this (types.ULong, v, loc)
                {
-                       type = TypeManager.uint64_type;
-                       eclass = ExprClass.Value;
-                       Value = v;
                }
 
-               public override void Emit (EmitContext ec)
+               public ULongConstant (TypeSpec type, ulong v, Location loc)
+                       : base (type, loc)
                {
-                       ILGenerator ig = ec.ig;
+                       Value = v;
+               }
 
-                       LongLiteral.EmitLong (ig, unchecked ((long) Value));
+               public override void EncodeAttributeValue (IMemberContext rc, AttributeEncoder enc, TypeSpec targetType)
+               {
+                       enc.Encode (Value);
                }
 
-               public override string AsString ()
+               public override void Emit (EmitContext ec)
                {
-                       return Value.ToString ();
+                       ec.EmitLong (unchecked ((long) Value));
                }
 
                public override object GetValue ()
@@ -1289,9 +1456,14 @@ namespace Mono.CSharp {
                        return Value;
                }
 
+               public override long GetValueAsLong ()
+               {
+                       return (long) Value;
+               }
+
                public override Constant Increment ()
                {
-                       return new ULongConstant (checked(Value + 1), loc);
+                       return new ULongConstant (type, checked(Value + 1), loc);
                }
 
                public override bool IsDefaultValue {
@@ -1305,59 +1477,59 @@ namespace Mono.CSharp {
                                return false;
                        }
                }
+               
+               public override bool IsOneInteger {
+                       get {
+                               return Value == 1;
+                       }
+               }               
 
                public override bool IsZeroInteger {
                        get { return Value == 0; }
                }
 
-               public override Constant ConvertExplicitly (bool in_checked_context, Type target_type)
+               public override Constant ConvertExplicitly (bool in_checked_context, TypeSpec target_type)
                {
-                       if (target_type == TypeManager.byte_type) {
+                       switch (target_type.BuildinType) {
+                       case BuildinTypeSpec.Type.Byte:
                                if (in_checked_context && Value > Byte.MaxValue)
                                        throw new OverflowException ();
-                               return new ByteConstant ((byte) Value, Location);
-                       }
-                       if (target_type == TypeManager.sbyte_type) {
+                               return new ByteConstant (target_type, (byte) Value, Location);
+                       case BuildinTypeSpec.Type.SByte:
                                if (in_checked_context && Value > ((ulong) SByte.MaxValue))
                                        throw new OverflowException ();
-                               return new SByteConstant ((sbyte) Value, Location);
-                       }
-                       if (target_type == TypeManager.short_type) {
+                               return new SByteConstant (target_type, (sbyte) Value, Location);
+                       case BuildinTypeSpec.Type.Short:
                                if (in_checked_context && Value > ((ulong) Int16.MaxValue))
                                        throw new OverflowException ();
-                               return new ShortConstant ((short) Value, Location);
-                       }
-                       if (target_type == TypeManager.ushort_type) {
+                               return new ShortConstant (target_type, (short) Value, Location);
+                       case BuildinTypeSpec.Type.UShort:
                                if (in_checked_context && Value > UInt16.MaxValue)
                                        throw new OverflowException ();
-                               return new UShortConstant ((ushort) Value, Location);
-                       }
-                       if (target_type == TypeManager.int32_type) {
+                               return new UShortConstant (target_type, (ushort) Value, Location);
+                       case BuildinTypeSpec.Type.Int:
                                if (in_checked_context && Value > UInt32.MaxValue)
                                        throw new OverflowException ();
-                               return new IntConstant ((int) Value, Location);
-                       }
-                       if (target_type == TypeManager.uint32_type) {
-                               if  (in_checked_context && Value > UInt32.MaxValue)
+                               return new IntConstant (target_type, (int) Value, Location);
+                       case BuildinTypeSpec.Type.UInt:
+                               if (in_checked_context && Value > UInt32.MaxValue)
                                        throw new OverflowException ();
-                               return new UIntConstant ((uint) Value, Location);
-                       }
-                       if (target_type == TypeManager.int64_type) {
+                               return new UIntConstant (target_type, (uint) Value, Location);
+                       case BuildinTypeSpec.Type.Long:
                                if (in_checked_context && Value > Int64.MaxValue)
                                        throw new OverflowException ();
-                               return new LongConstant ((long) Value, Location);
-                       }
-                       if (target_type == TypeManager.float_type)
-                               return new FloatConstant ((float) Value, Location);
-                       if (target_type == TypeManager.double_type)
-                               return new DoubleConstant ((double) Value, Location);
-                       if (target_type == TypeManager.char_type) {
+                               return new LongConstant (target_type, (long) Value, Location);
+                       case BuildinTypeSpec.Type.Float:
+                               return new FloatConstant (target_type, (float) Value, Location);
+                       case BuildinTypeSpec.Type.Double:
+                               return new DoubleConstant (target_type, (double) Value, Location);
+                       case BuildinTypeSpec.Type.Char:
                                if (in_checked_context && Value > Char.MaxValue)
                                        throw new OverflowException ();
-                               return new CharConstant ((char) Value, Location);
+                               return new CharConstant (target_type, (char) Value, Location);
+                       case BuildinTypeSpec.Type.Decimal:
+                               return new DecimalConstant (target_type, (decimal) Value, Location);
                        }
-                       if (target_type == TypeManager.decimal_type)
-                               return new DecimalConstant ((decimal) Value, Location);
 
                        return null;
                }
@@ -1365,24 +1537,30 @@ namespace Mono.CSharp {
        }
 
        public class FloatConstant : Constant {
-               public float Value;
+               public readonly float Value;
 
-               public FloatConstant (float v, Location loc):
-                       base (loc)
+               public FloatConstant (BuildinTypes types, float v, Location loc)
+                       : this (types.Float, v, loc)
                {
-                       type = TypeManager.float_type;
+               }
+
+               public FloatConstant (TypeSpec type, float v, Location loc)
+                       : base (loc)
+               {
+                       this.type = type;
                        eclass = ExprClass.Value;
+
                        Value = v;
                }
 
-               public override void Emit (EmitContext ec)
+               public override void EncodeAttributeValue (IMemberContext rc, AttributeEncoder enc, TypeSpec targetType)
                {
-                       ec.ig.Emit (OpCodes.Ldc_R4, Value);
+                       enc.Encode (Value);
                }
 
-               public override string AsString ()
+               public override void Emit (EmitContext ec)
                {
-                       return Value.ToString ();
+                       ec.Emit (OpCodes.Ldc_R4, Value);
                }
 
                public override object GetValue ()
@@ -1390,9 +1568,14 @@ namespace Mono.CSharp {
                        return Value;
                }
 
-               public override Constant Increment ()
+               public override string GetValueAsLiteral ()
+               {
+                       return Value.ToString ();
+               }
+
+               public override long GetValueAsLong ()
                {
-                       return new FloatConstant (checked(Value + 1), loc);
+                       throw new NotSupportedException ();
                }
 
                public override bool IsDefaultValue {
@@ -1407,100 +1590,100 @@ namespace Mono.CSharp {
                        }
                }
 
-               public override Constant ConvertExplicitly (bool in_checked_context, Type target_type)
+               public override Constant ConvertExplicitly (bool in_checked_context, TypeSpec target_type)
                {
-                       if (target_type == TypeManager.byte_type) {
-                               if (in_checked_context){
-                                       if (Value < byte.MinValue || Value > byte.MaxValue)
+                       switch (target_type.BuildinType) {
+                       case BuildinTypeSpec.Type.Byte:
+                               if (in_checked_context) {
+                                       if (Value < byte.MinValue || Value > byte.MaxValue || float.IsNaN (Value))
                                                throw new OverflowException ();
                                }
-                               return new ByteConstant ((byte) Value, Location);
-                       }
-                       if (target_type == TypeManager.sbyte_type) {
-                               if (in_checked_context){
-                                       if (Value <  sbyte.MinValue || Value > sbyte.MaxValue)
+                               return new ByteConstant (target_type, (byte) Value, Location);
+                       case BuildinTypeSpec.Type.SByte:
+                               if (in_checked_context) {
+                                       if (Value < sbyte.MinValue || Value > sbyte.MaxValue || float.IsNaN (Value))
                                                throw new OverflowException ();
                                }
-                               return new SByteConstant ((sbyte) Value, Location);
-                       }
-                       if (target_type == TypeManager.short_type) {
-                               if (in_checked_context){
-                                       if (Value < short.MinValue || Value > short.MaxValue)
+                               return new SByteConstant (target_type, (sbyte) Value, Location);
+                       case BuildinTypeSpec.Type.Short:
+                               if (in_checked_context) {
+                                       if (Value < short.MinValue || Value > short.MaxValue || float.IsNaN (Value))
                                                throw new OverflowException ();
                                }
-                               return new ShortConstant ((short) Value, Location);
-                       }
-                       if (target_type == TypeManager.ushort_type) {
-                               if (in_checked_context){
-                                       if (Value < ushort.MinValue || Value > ushort.MaxValue)
+                               return new ShortConstant (target_type, (short) Value, Location);
+                       case BuildinTypeSpec.Type.UShort:
+                               if (in_checked_context) {
+                                       if (Value < ushort.MinValue || Value > ushort.MaxValue || float.IsNaN (Value))
                                                throw new OverflowException ();
                                }
-                               return new UShortConstant ((ushort) Value, Location);
-                       }
-                       if (target_type == TypeManager.int32_type) {
-                               if (in_checked_context){
-                                       if (Value < int.MinValue || Value > int.MaxValue)
+                               return new UShortConstant (target_type, (ushort) Value, Location);
+                       case BuildinTypeSpec.Type.Int:
+                               if (in_checked_context) {
+                                       if (Value < int.MinValue || Value > int.MaxValue || float.IsNaN (Value))
                                                throw new OverflowException ();
                                }
-                               return new IntConstant ((int) Value, Location);
-                       }
-                       if (target_type == TypeManager.uint32_type) {
-                               if (in_checked_context){
-                                       if (Value < uint.MinValue || Value > uint.MaxValue)
+                               return new IntConstant (target_type, (int) Value, Location);
+                       case BuildinTypeSpec.Type.UInt:
+                               if (in_checked_context) {
+                                       if (Value < uint.MinValue || Value > uint.MaxValue || float.IsNaN (Value))
                                                throw new OverflowException ();
                                }
-                               return new UIntConstant ((uint) Value, Location);
-                       }
-                       if (target_type == TypeManager.int64_type) {
-                               if (in_checked_context){
-                                       if (Value < long.MinValue || Value > long.MaxValue)
+                               return new UIntConstant (target_type, (uint) Value, Location);
+                       case BuildinTypeSpec.Type.Long:
+                               if (in_checked_context) {
+                                       if (Value < long.MinValue || Value > long.MaxValue || float.IsNaN (Value))
                                                throw new OverflowException ();
                                }
-                               return new LongConstant ((long) Value, Location);
-                       }
-                       if (target_type == TypeManager.uint64_type) {
-                               if (in_checked_context){
-                                       if (Value < ulong.MinValue || Value > ulong.MaxValue)
+                               return new LongConstant (target_type, (long) Value, Location);
+                       case BuildinTypeSpec.Type.ULong:
+                               if (in_checked_context) {
+                                       if (Value < ulong.MinValue || Value > ulong.MaxValue || float.IsNaN (Value))
                                                throw new OverflowException ();
                                }
-                               return new ULongConstant ((ulong) Value, Location);
-                       }
-                       if (target_type == TypeManager.double_type)
-                               return new DoubleConstant ((double) Value, Location);
-                       if (target_type == TypeManager.char_type) {
-                               if (in_checked_context){
-                                       if (Value < (float) char.MinValue || Value > (float) char.MaxValue)
+                               return new ULongConstant (target_type, (ulong) Value, Location);
+                       case BuildinTypeSpec.Type.Double:
+                               return new DoubleConstant (target_type, (double) Value, Location);
+                       case BuildinTypeSpec.Type.Char:
+                               if (in_checked_context) {
+                                       if (Value < (float) char.MinValue || Value > (float) char.MaxValue || float.IsNaN (Value))
                                                throw new OverflowException ();
                                }
-                               return new CharConstant ((char) Value, Location);
+                               return new CharConstant (target_type, (char) Value, Location);
+                       case BuildinTypeSpec.Type.Decimal:
+                               return new DecimalConstant (target_type, (decimal) Value, Location);
                        }
-                       if (target_type == TypeManager.decimal_type)
-                               return new DecimalConstant ((decimal) Value, Location);
 
                        return null;
                }
 
        }
 
-       public class DoubleConstant : Constant {
-               public double Value;
+       public class DoubleConstant : Constant
+       {
+               public readonly double Value;
 
-               public DoubleConstant (double v, Location loc):
-                       base (loc)
+               public DoubleConstant (BuildinTypes types, double v, Location loc)
+                       : this (types.Double, v, loc)
                {
-                       type = TypeManager.double_type;
+               }
+
+               public DoubleConstant (TypeSpec type, double v, Location loc)
+                       : base (loc)
+               {
+                       this.type = type;
                        eclass = ExprClass.Value;
+
                        Value = v;
                }
 
-               public override void Emit (EmitContext ec)
+               public override void EncodeAttributeValue (IMemberContext rc, AttributeEncoder enc, TypeSpec targetType)
                {
-                       ec.ig.Emit (OpCodes.Ldc_R8, Value);
+                       enc.Encode (Value);
                }
 
-               public override string AsString ()
+               public override void Emit (EmitContext ec)
                {
-                       return Value.ToString ();
+                       ec.Emit (OpCodes.Ldc_R8, Value);
                }
 
                public override object GetValue ()
@@ -1508,9 +1691,14 @@ namespace Mono.CSharp {
                        return Value;
                }
 
-               public override Constant Increment ()
+               public override string GetValueAsLiteral ()
                {
-                       return new DoubleConstant (checked(Value + 1), loc);
+                       return Value.ToString ();
+               }
+
+               public override long GetValueAsLong ()
+               {
+                       throw new NotSupportedException ();
                }
 
                public override bool IsDefaultValue {
@@ -1525,75 +1713,68 @@ namespace Mono.CSharp {
                        }
                }
 
-               public override Constant ConvertExplicitly (bool in_checked_context, Type target_type)
+               public override Constant ConvertExplicitly (bool in_checked_context, TypeSpec target_type)
                {
-                       if (target_type == TypeManager.byte_type) {
-                               if (in_checked_context){
-                                       if (Value < Byte.MinValue || Value > Byte.MaxValue)
+                       switch (target_type.BuildinType) {
+                       case BuildinTypeSpec.Type.Byte:
+                               if (in_checked_context) {
+                                       if (Value < Byte.MinValue || Value > Byte.MaxValue || double.IsNaN (Value))
                                                throw new OverflowException ();
                                }
-                               return new ByteConstant ((byte) Value, Location);
-                       }
-                       if (target_type == TypeManager.sbyte_type) {
-                               if (in_checked_context){
-                                       if (Value < SByte.MinValue || Value > SByte.MaxValue)
+                               return new ByteConstant (target_type, (byte) Value, Location);
+                       case BuildinTypeSpec.Type.SByte:
+                               if (in_checked_context) {
+                                       if (Value < SByte.MinValue || Value > SByte.MaxValue || double.IsNaN (Value))
                                                throw new OverflowException ();
                                }
-                               return new SByteConstant ((sbyte) Value, Location);
-                       }
-                       if (target_type == TypeManager.short_type) {
-                               if (in_checked_context){
-                                       if (Value < short.MinValue || Value > short.MaxValue)
+                               return new SByteConstant (target_type, (sbyte) Value, Location);
+                       case BuildinTypeSpec.Type.Short:
+                               if (in_checked_context) {
+                                       if (Value < short.MinValue || Value > short.MaxValue || double.IsNaN (Value))
                                                throw new OverflowException ();
                                }
-                               return new ShortConstant ((short) Value, Location);
-                       }
-                       if (target_type == TypeManager.ushort_type) {
-                               if (in_checked_context){
-                                       if (Value < ushort.MinValue || Value > ushort.MaxValue)
+                               return new ShortConstant (target_type, (short) Value, Location);
+                       case BuildinTypeSpec.Type.UShort:
+                               if (in_checked_context) {
+                                       if (Value < ushort.MinValue || Value > ushort.MaxValue || double.IsNaN (Value))
                                                throw new OverflowException ();
                                }
-                               return new UShortConstant ((ushort) Value, Location);
-                       }
-                       if (target_type == TypeManager.int32_type) {
-                               if (in_checked_context){
-                                       if (Value < int.MinValue || Value > int.MaxValue)
+                               return new UShortConstant (target_type, (ushort) Value, Location);
+                       case BuildinTypeSpec.Type.Int:
+                               if (in_checked_context) {
+                                       if (Value < int.MinValue || Value > int.MaxValue || double.IsNaN (Value))
                                                throw new OverflowException ();
                                }
-                               return new IntConstant ((int) Value, Location);
-                       }
-                       if (target_type == TypeManager.uint32_type) {
-                               if (in_checked_context){
-                                       if (Value < uint.MinValue || Value > uint.MaxValue)
+                               return new IntConstant (target_type, (int) Value, Location);
+                       case BuildinTypeSpec.Type.UInt:
+                               if (in_checked_context) {
+                                       if (Value < uint.MinValue || Value > uint.MaxValue || double.IsNaN (Value))
                                                throw new OverflowException ();
                                }
-                               return new UIntConstant ((uint) Value, Location);
-                       }
-                       if (target_type == TypeManager.int64_type) {
-                               if (in_checked_context){
-                                       if (Value < long.MinValue || Value > long.MaxValue)
+                               return new UIntConstant (target_type, (uint) Value, Location);
+                       case BuildinTypeSpec.Type.Long:
+                               if (in_checked_context) {
+                                       if (Value < long.MinValue || Value > long.MaxValue || double.IsNaN (Value))
                                                throw new OverflowException ();
                                }
-                               return new LongConstant ((long) Value, Location);
-                       }
-                       if (target_type == TypeManager.uint64_type) {
-                               if (in_checked_context){
-                                       if (Value < ulong.MinValue || Value > ulong.MaxValue)
+                               return new LongConstant (target_type, (long) Value, Location);
+                       case BuildinTypeSpec.Type.ULong:
+                               if (in_checked_context) {
+                                       if (Value < ulong.MinValue || Value > ulong.MaxValue || double.IsNaN (Value))
                                                throw new OverflowException ();
                                }
-                               return new ULongConstant ((ulong) Value, Location);
-                       }
-                       if (target_type == TypeManager.float_type)
-                               return new FloatConstant ((float) Value, Location);
-                       if (target_type == TypeManager.char_type) {
-                               if (in_checked_context){
-                                       if (Value < (double) char.MinValue || Value > (double) char.MaxValue)
+                               return new ULongConstant (target_type, (ulong) Value, Location);
+                       case BuildinTypeSpec.Type.Float:
+                               return new FloatConstant (target_type, (float) Value, Location);
+                       case BuildinTypeSpec.Type.Char:
+                               if (in_checked_context) {
+                                       if (Value < (double) char.MinValue || Value > (double) char.MaxValue || double.IsNaN (Value))
                                                throw new OverflowException ();
                                }
-                               return new CharConstant ((char) Value, Location);
+                               return new CharConstant (target_type, (char) Value, Location);
+                       case BuildinTypeSpec.Type.Decimal:
+                               return new DecimalConstant (target_type, (decimal) Value, Location);
                        }
-                       if (target_type == TypeManager.decimal_type)
-                               return new DecimalConstant ((decimal) Value, Location);
 
                        return null;
                }
@@ -1603,77 +1784,65 @@ namespace Mono.CSharp {
        public class DecimalConstant : Constant {
                public readonly decimal Value;
 
-               public DecimalConstant (decimal d, Location loc):
-                       base (loc)
+               public DecimalConstant (BuildinTypes types, decimal d, Location loc)
+                       : this (types.Decimal, d, loc)
                {
-                       type = TypeManager.decimal_type;
-                       eclass = ExprClass.Value;
-                       Value = d;
                }
 
-               override public string AsString ()
+               public DecimalConstant (TypeSpec type, decimal d, Location loc)
+                       : base (loc)
                {
-                       return Value.ToString ();
-               }
+                       this.type = type;
+                       eclass = ExprClass.Value;
 
-               public override object GetValue ()
-               {
-                       return (object) Value;
+                       Value = d;
                }
 
                public override void Emit (EmitContext ec)
                {
-                       ILGenerator ig = ec.ig;
+                       MethodSpec m;
 
-                       int [] words = Decimal.GetBits (Value);
+                       int [] words = decimal.GetBits (Value);
                        int power = (words [3] >> 16) & 0xff;
 
-                       if (power == 0 && Value <= int.MaxValue && Value >= int.MinValue)
-                       {
-                               if (TypeManager.void_decimal_ctor_int_arg == null) {
-                                       TypeManager.void_decimal_ctor_int_arg = TypeManager.GetPredefinedConstructor (
-                                               TypeManager.decimal_type, loc, TypeManager.int32_type);
-
-                                       if (TypeManager.void_decimal_ctor_int_arg == null)
+                       if (power == 0) {
+                               if (Value <= int.MaxValue && Value >= int.MinValue) {
+                                       m = ec.Module.PredefinedMembers.DecimalCtorInt.Resolve (loc);
+                                       if (m == null) {
                                                return;
+                                       }
+
+                                       ec.EmitInt ((int) Value);
+                                       ec.Emit (OpCodes.Newobj, m);
+                                       return;
                                }
 
-                               IntConstant.EmitInt (ig, (int)Value);
-                               ig.Emit (OpCodes.Newobj, TypeManager.void_decimal_ctor_int_arg);
-                               return;
-                       }
+                               if (Value <= long.MaxValue && Value >= long.MinValue) {
+                                       m = ec.Module.PredefinedMembers.DecimalCtorLong.Resolve (loc);
+                                       if (m == null) {
+                                               return;
+                                       }
 
-                       
-                       //
-                       // FIXME: we could optimize this, and call a better 
-                       // constructor
-                       //
+                                       ec.EmitLong ((long) Value);
+                                       ec.Emit (OpCodes.Newobj, m);
+                                       return;
+                               }
+                       }
 
-                       IntConstant.EmitInt (ig, words [0]);
-                       IntConstant.EmitInt (ig, words [1]);
-                       IntConstant.EmitInt (ig, words [2]);
+                       ec.EmitInt (words [0]);
+                       ec.EmitInt (words [1]);
+                       ec.EmitInt (words [2]);
 
                        // sign
-                       IntConstant.EmitInt (ig, words [3] >> 31);
+                       ec.EmitInt (words [3] >> 31);
 
                        // power
-                       IntConstant.EmitInt (ig, power);
+                       ec.EmitInt (power);
 
-                       if (TypeManager.void_decimal_ctor_five_args == null) {
-                               TypeManager.void_decimal_ctor_five_args = TypeManager.GetPredefinedConstructor (
-                                       TypeManager.decimal_type, loc, TypeManager.int32_type, TypeManager.int32_type,
-                                       TypeManager.int32_type, TypeManager.bool_type, TypeManager.byte_type);
-
-                               if (TypeManager.void_decimal_ctor_five_args == null)
-                                       return;
+                       m = ec.Module.PredefinedMembers.DecimalCtor.Resolve (loc);
+                       if (m != null) {
+                               ec.Emit (OpCodes.Newobj, m);
                        }
-
-                       ig.Emit (OpCodes.Newobj, TypeManager.void_decimal_ctor_five_args);
-               }
-
-               public override Constant Increment ()
-               {
-                       return new DecimalConstant (checked (Value + 1), loc);
                }
 
                public override bool IsDefaultValue {
@@ -1688,69 +1857,117 @@ namespace Mono.CSharp {
                        }
                }
 
-               public override Constant ConvertExplicitly (bool in_checked_context, Type target_type)
-               {
-                       if (target_type == TypeManager.sbyte_type)
-                               return new SByteConstant ((sbyte)Value, loc);
-                       if (target_type == TypeManager.byte_type)
-                               return new ByteConstant ((byte)Value, loc);
-                       if (target_type == TypeManager.short_type)
-                               return new ShortConstant ((short)Value, loc);
-                       if (target_type == TypeManager.ushort_type)
-                               return new UShortConstant ((ushort)Value, loc);
-                       if (target_type == TypeManager.int32_type)
-                               return new IntConstant ((int)Value, loc);
-                       if (target_type == TypeManager.uint32_type)
-                               return new UIntConstant ((uint)Value, loc);
-                       if (target_type == TypeManager.int64_type)
-                               return new LongConstant ((long)Value, loc);
-                       if (target_type == TypeManager.uint64_type)
-                               return new ULongConstant ((ulong)Value, loc);
-                       if (target_type == TypeManager.char_type)
-                               return new CharConstant ((char)Value, loc);
-                       if (target_type == TypeManager.float_type)
-                               return new FloatConstant ((float)Value, loc);
-                       if (target_type == TypeManager.double_type)
-                               return new DoubleConstant ((double)Value, loc);
+               public override Constant ConvertExplicitly (bool in_checked_context, TypeSpec target_type)
+               {
+                       switch (target_type.BuildinType) {
+                       case BuildinTypeSpec.Type.SByte:
+                               return new SByteConstant (target_type, (sbyte) Value, loc);
+                       case BuildinTypeSpec.Type.Byte:
+                               return new ByteConstant (target_type, (byte) Value, loc);
+                       case BuildinTypeSpec.Type.Short:
+                               return new ShortConstant (target_type, (short) Value, loc);
+                       case BuildinTypeSpec.Type.UShort:
+                               return new UShortConstant (target_type, (ushort) Value, loc);
+                       case BuildinTypeSpec.Type.Int:
+                               return new IntConstant (target_type, (int) Value, loc);
+                       case BuildinTypeSpec.Type.UInt:
+                               return new UIntConstant (target_type, (uint) Value, loc);
+                       case BuildinTypeSpec.Type.Long:
+                               return new LongConstant (target_type, (long) Value, loc);
+                       case BuildinTypeSpec.Type.ULong:
+                               return new ULongConstant (target_type, (ulong) Value, loc);
+                       case BuildinTypeSpec.Type.Char:
+                               return new CharConstant (target_type, (char) Value, loc);
+                       case BuildinTypeSpec.Type.Float:
+                               return new FloatConstant (target_type, (float) Value, loc);
+                       case BuildinTypeSpec.Type.Double:
+                               return new DoubleConstant (target_type, (double) Value, loc);
+                       }
 
                        return null;
                }
 
+               public override object GetValue ()
+               {
+                       return Value;
+               }
+
+               public override string GetValueAsLiteral ()
+               {
+                       return Value.ToString () + "M";
+               }
+
+               public override long GetValueAsLong ()
+               {
+                       throw new NotSupportedException ();
+               }
        }
 
        public class StringConstant : Constant {
                public readonly string Value;
 
-               public StringConstant (string s, Location loc):
-                       base (loc)
+               public StringConstant (BuildinTypes types, string s, Location loc)
+                       : this (types.String, s, loc)
                {
-                       type = TypeManager.string_type;
+               }
+
+               public StringConstant (TypeSpec type, string s, Location loc)
+                       : base (loc)
+               {
+                       this.type = type;
                        eclass = ExprClass.Value;
+
                        Value = s;
                }
 
-               // FIXME: Escape the string.
-               override public string AsString ()
+               public override object GetValue ()
                {
+                       return Value;
+               }
+
+               public override string GetValueAsLiteral ()
+               {
+                       // FIXME: Escape the string.
                        return "\"" + Value + "\"";
                }
 
-               public override object GetValue ()
+               public override long GetValueAsLong ()
                {
-                       return Value;
+                       throw new NotSupportedException ();
                }
                
                public override void Emit (EmitContext ec)
                {
-                       if (Value == null)
-                               ec.ig.Emit (OpCodes.Ldnull);
-                       else
-                               ec.ig.Emit (OpCodes.Ldstr, Value);
+                       if (Value == null) {
+                               ec.Emit (OpCodes.Ldnull);
+                               return;
+                       }
+
+                       //
+                       // Use string.Empty for both literals and constants even if
+                       // it's not allowed at language level
+                       //
+                       if (Value.Length == 0 && ec.Module.Compiler.Settings.Optimize) {
+                               var string_type = ec.BuildinTypes.String;
+                               if (ec.CurrentType != string_type) {
+                                       var m = ec.Module.PredefinedMembers.StringEmpty.Get ();
+                                       if (m != null) {
+                                               ec.Emit (OpCodes.Ldsfld, m);
+                                               return;
+                                       }
+                               }
+                       }
+
+                       ec.Emit (OpCodes.Ldstr, Value);
                }
 
-               public override Constant Increment ()
+               public override void EncodeAttributeValue (IMemberContext rc, AttributeEncoder enc, TypeSpec targetType)
                {
-                       throw new NotSupportedException ();
+                       // cast to object
+                       if (type != targetType)
+                               enc.Encode (type);
+
+                       enc.Encode (Value);
                }
 
                public override bool IsDefaultValue {
@@ -1765,82 +1982,238 @@ namespace Mono.CSharp {
                        }
                }
 
-               public override Constant ConvertExplicitly (bool in_checked_context, Type target_type)
+               public override bool IsNull {
+                       get {
+                               return IsDefaultValue;
+                       }
+               }
+
+               public override Constant ConvertExplicitly (bool in_checked_context, TypeSpec target_type)
                {
                        return null;
                }
        }
 
+       //
+       // Null constant can have its own type, think of `default (Foo)'
+       //
+       public class NullConstant : Constant
+       {
+               public NullConstant (TypeSpec type, Location loc)
+                       : base (loc)
+               {
+                       eclass = ExprClass.Value;
+                       this.type = type;
+               }
+
+               public override Expression CreateExpressionTree (ResolveContext ec)
+               {
+                       if (type == InternalType.NullLiteral || type.BuildinType == BuildinTypeSpec.Type.Object) {
+                               // Optimized version, also avoids referencing literal internal type
+                               Arguments args = new Arguments (1);
+                               args.Add (new Argument (this));
+                               return CreateExpressionFactoryCall (ec, "Constant", args);
+                       }
+
+                       return base.CreateExpressionTree (ec);
+               }
+
+               public override void EncodeAttributeValue (IMemberContext rc, AttributeEncoder enc, TypeSpec targetType)
+               {
+                       // Type it as string cast
+                       if (targetType.BuildinType == BuildinTypeSpec.Type.Object)
+                               enc.Encode (rc.Module.Compiler.BuildinTypes.String);
+
+                       var ac = targetType as ArrayContainer;
+                       if (ac != null) {
+                               if (ac.Rank != 1 || ac.Element.IsArray)
+                                       base.EncodeAttributeValue (rc, enc, targetType);
+                               else
+                                       enc.Encode (uint.MaxValue);
+                       } else {
+                               enc.Encode (byte.MaxValue);
+                       }
+               }
+
+               public override void Emit (EmitContext ec)
+               {
+                       ec.Emit (OpCodes.Ldnull);
+
+                       // Only to make verifier happy
+                       if (type.IsGenericParameter)
+                               ec.Emit (OpCodes.Unbox_Any, type);
+               }
+
+               public override string ExprClassName {
+                       get {
+                               return GetSignatureForError ();
+                       }
+               }
+
+               public override Constant ConvertExplicitly (bool inCheckedContext, TypeSpec targetType)
+               {
+                       if (targetType.IsPointer) {
+                               if (IsLiteral || this is NullPointer)
+                                       return new NullPointer (targetType, loc);
+
+                               return null;
+                       }
+
+                       // Exlude internal compiler types
+                       if (targetType.Kind == MemberKind.InternalCompilerType && targetType.BuildinType != BuildinTypeSpec.Type.Dynamic)
+                               return null;
+
+                       if (!IsLiteral && !Convert.ImplicitStandardConversionExists (this, targetType))
+                               return null;
+
+                       if (TypeManager.IsReferenceType (targetType))
+                               return new NullConstant (targetType, loc);
+
+                       if (targetType.IsNullableType)
+                               return Nullable.LiftedNull.Create (targetType, loc);
+
+                       return null;
+               }
+
+               public override Constant ConvertImplicitly (TypeSpec targetType)
+               {
+                       return ConvertExplicitly (false, targetType);
+               }
+
+               public override string GetSignatureForError ()
+               {
+                       return "null";
+               }
+
+               public override object GetValue ()
+               {
+                       return null;
+               }
+
+               public override string GetValueAsLiteral ()
+               {
+                       return GetSignatureForError ();
+               }
+
+               public override long GetValueAsLong ()
+               {
+                       throw new NotSupportedException ();
+               }
+
+               public override bool IsDefaultValue {
+                       get { return true; }
+               }
+
+               public override bool IsNegative {
+                       get { return false; }
+               }
+
+               public override bool IsNull {
+                       get { return true; }
+               }
+
+               public override bool IsZeroInteger {
+                       get { return true; }
+               }
+       }
+
+
+       //
+       // A null constant in a pointer context
+       //
+       class NullPointer : NullConstant
+       {
+               public NullPointer (TypeSpec type, Location loc)
+                       : base (type, loc)
+               {
+               }
+
+               public override Expression CreateExpressionTree (ResolveContext ec)
+               {
+                       Error_PointerInsideExpressionTree (ec);
+                       return base.CreateExpressionTree (ec);
+               }
+
+               public override void Emit (EmitContext ec)
+               {
+                       //
+                       // Emits null pointer
+                       //
+                       ec.Emit (OpCodes.Ldc_I4_0);
+                       ec.Emit (OpCodes.Conv_U);
+               }
+       }
+
        /// <summary>
        ///   The value is constant, but when emitted has a side effect.  This is
        ///   used by BitwiseAnd to ensure that the second expression is invoked
        ///   regardless of the value of the left side.  
        /// </summary>
-       
        public class SideEffectConstant : Constant {
-               public Constant left;
-               Expression right;
+               public readonly Constant value;
+               Expression side_effect;
                
-               public SideEffectConstant (Constant left, Expression right, Location loc) : base (loc)
+               public SideEffectConstant (Constant value, Expression side_effect, Location loc)
+                       : base (loc)
                {
-                       this.left = left;
-                       this.right = right;
+                       this.value = value;
+                       type = value.Type;
                        eclass = ExprClass.Value;
-                       type = left.Type;
+
+                       while (side_effect is SideEffectConstant)
+                               side_effect = ((SideEffectConstant) side_effect).side_effect;
+                       this.side_effect = side_effect;
                }
 
-               public override string AsString ()
+               public override object GetValue ()
                {
-                       return left.AsString ();
+                       return value.GetValue ();
                }
 
-               public override object GetValue ()
+               public override string GetValueAsLiteral ()
                {
-                       return left.GetValue ();
+                       return value.GetValueAsLiteral ();
+               }
+
+               public override long GetValueAsLong ()
+               {
+                       return value.GetValueAsLong ();
                }
 
                public override void Emit (EmitContext ec)
                {
-                       //
-                       // This happens when both sides have side-effects and
-                       // the result is a constant
-                       //
-                       if (left is SideEffectConstant) {
-                               left.Emit (ec);
-                               ec.ig.Emit (OpCodes.Pop);
-                       }
+                       side_effect.EmitSideEffect (ec);
+                       value.Emit (ec);
+               }
 
-                       right.Emit (ec);
+               public override void EmitSideEffect (EmitContext ec)
+               {
+                       side_effect.EmitSideEffect (ec);
+                       value.EmitSideEffect (ec);
                }
 
                public override bool IsDefaultValue {
-                       get {
-                               return left.IsDefaultValue;
-                       }
+                       get { return value.IsDefaultValue; }
                }
 
-               public override Constant Increment ()
-               {
-                       throw new NotSupportedException ();
-               }
-               
                public override bool IsNegative {
-                       get {
-                               return left.IsNegative;
-                       }
+                       get { return value.IsNegative; }
                }
 
                public override bool IsZeroInteger {
-                       get {
-                               return left.IsZeroInteger;
-                       }
+                       get { return value.IsZeroInteger; }
                }
 
-               public override Constant ConvertExplicitly (bool in_checked_context, Type target_type)
+               public override Constant ConvertExplicitly (bool in_checked_context, TypeSpec target_type)
                {
-                       return left.ConvertExplicitly (in_checked_context, target_type);
+                       Constant new_value = value.ConvertExplicitly (in_checked_context, target_type);
+                       if (new_value == null)
+                               return null;
+
+                       var c = new SideEffectConstant (new_value, side_effect, new_value.Location);
+                       c.type = target_type;
+                       c.eclass = eclass;
+                       return c;
                }
        }
 }
-
-