Add some new classes/enums/delegates for 2.0 and some new CAS unit tests
[mono.git] / mcs / mcs / cfold.cs
old mode 100755 (executable)
new mode 100644 (file)
index 7d08602..9e8a5a1
@@ -59,16 +59,22 @@ namespace Mono.CSharp {
                                // converted to type ulong.  or an error ocurrs if the other
                                // operand is of type sbyte, short, int or long
                                //
+#if WRONG
                                Constant match, other;
+#endif
                                        
                                if (left is ULongConstant){
+#if WRONG
                                        other = right;
                                        match = left;
+#endif
                                        if (!(right is ULongConstant))
                                                right = right.ToULong (loc);
                                } else {
+#if WRONG
                                        other = left;
                                        match = right;
+#endif
                                        left = left.ToULong (loc);
                                }
 
@@ -98,57 +104,49 @@ namespace Mono.CSharp {
                                // operand is of type sbyte, short or int, the operands are
                                // converted to type long.
                                //
-                               Constant match, other;
-                               if (left is UIntConstant){
+                               Constant other;
+                               if (left is UIntConstant)
                                        other = right;
-                                       match = left;
-                               } else {
+                               else
                                        other = left;
-                                       match = right;
-                               }
 
                                // Nothing to do.
                                if (other is UIntConstant)
                                        return;
 
-                               if (other is SByteConstant || other is ShortConstant ||
-                                   other is IntConstant){
+                               IntConstant ic = other as IntConstant;
+                               if (ic != null){
+                                       if (ic.Value >= 0){
+                                               if (left == other)
+                                                       left = new UIntConstant ((uint) ic.Value, ic.Location);
+                                               else
+                                                       right = new UIntConstant ((uint) ic.Value, ic.Location);
+                                               return;
+                                       }
+                               }
+                               
+                               if (other is SByteConstant || other is ShortConstant || ic != null){
                                        left = left.ToLong (loc);
                                        right = right.ToLong (loc);
+                               } else {
+                                       left = left.ToUInt (loc);
+                                       right = left.ToUInt (loc);
                                }
 
                                return;
+                       } else if (left is DecimalConstant || right is DecimalConstant) {
+                               if (!(left is DecimalConstant))
+                                       left = left.ToDecimal (loc);
+                               else if (!(right is DecimalConstant))
+                                       right = right.ToDecimal (loc);
+                               return;
                        } else if (left is EnumConstant || right is EnumConstant){
-                               //
-                               // If either operand is an enum constant, the other one must
-                               // be implicitly convertable to that enum's underlying type.
-                               //
-                               EnumConstant match;
-                               Constant other;
-                               if (left is EnumConstant){
-                                       other = right;
-                                       match = (EnumConstant) left;
-                               } else {
-                                       other = left;
-                                       match = (EnumConstant) right;
-                               }
-
-                               bool need_check = (other is EnumConstant) ||
-                                       ((oper != Binary.Operator.Addition) &&
-                                        (oper != Binary.Operator.Subtraction));
-
-                               if (need_check &&
-                                   !Convert.ImplicitConversionExists (ec, match, other.Type)) {
-                                       Convert.Error_CannotImplicitConversion (loc, match.Type, other.Type);
-                                       left = null;
-                                       right = null;
-                                       return;
-                               }
-
                                if (left is EnumConstant)
                                        left = ((EnumConstant) left).Child;
                                if (right is EnumConstant)
                                        right = ((EnumConstant) right).Child;
+
+                               DoConstantNumericPromotions (ec, oper, ref left, ref right, loc);
                                return;
 
                        } else {
@@ -180,7 +178,7 @@ namespace Mono.CSharp {
                        Type rt = right.Type;
                        Type result_type = null;
                        bool bool_res;
-                       
+
                        //
                        // Enumerator folding
                        //
@@ -205,12 +203,12 @@ namespace Mono.CSharp {
                                DoConstantNumericPromotions (ec, oper, ref left, ref right, loc);
                                if (left == null || right == null)
                                        return null;
-                               
+
                                if (left is IntConstant){
                                        IntConstant v;
                                        int res = ((IntConstant) left).Value | ((IntConstant) right).Value;
                                        
-                                       v = new IntConstant (res);
+                                       v = new IntConstant (res, left.Location);
                                        if (result_type == null)
                                                return v;
                                        else
@@ -219,7 +217,7 @@ namespace Mono.CSharp {
                                        UIntConstant v;
                                        uint res = ((UIntConstant)left).Value | ((UIntConstant)right).Value;
                                        
-                                       v = new UIntConstant (res);
+                                       v = new UIntConstant (res, left.Location);
                                        if (result_type == null)
                                                return v;
                                        else
@@ -228,7 +226,7 @@ namespace Mono.CSharp {
                                        LongConstant v;
                                        long res = ((LongConstant)left).Value | ((LongConstant)right).Value;
                                        
-                                       v = new LongConstant (res);
+                                       v = new LongConstant (res, left.Location);
                                        if (result_type == null)
                                                return v;
                                        else
@@ -238,7 +236,7 @@ namespace Mono.CSharp {
                                        ulong res = ((ULongConstant)left).Value |
                                                ((ULongConstant)right).Value;
                                        
-                                       v = new ULongConstant (res);
+                                       v = new ULongConstant (res, left.Location);
                                        if (result_type == null)
                                                return v;
                                        else
@@ -248,7 +246,7 @@ namespace Mono.CSharp {
                                        ushort res = (ushort) (((UShortConstant)left).Value |
                                                               ((UShortConstant)right).Value);
                                        
-                                       v = new UShortConstant (res);
+                                       v = new UShortConstant (res, left.Location);
                                        if (result_type == null)
                                                return v;
                                        else
@@ -258,7 +256,7 @@ namespace Mono.CSharp {
                                        short res = (short) (((ShortConstant)left).Value |
                                                             ((ShortConstant)right).Value);
                                        
-                                       v = new ShortConstant (res);
+                                       v = new ShortConstant (res, left.Location);
                                        if (result_type == null)
                                                return v;
                                        else
@@ -275,7 +273,7 @@ namespace Mono.CSharp {
                                        IntConstant v;
                                        int res = ((IntConstant) left).Value & ((IntConstant) right).Value;
                                        
-                                       v = new IntConstant (res);
+                                       v = new IntConstant (res, left.Location);
                                        if (result_type == null)
                                                return v;
                                        else
@@ -284,7 +282,7 @@ namespace Mono.CSharp {
                                        UIntConstant v;
                                        uint res = ((UIntConstant)left).Value & ((UIntConstant)right).Value;
                                        
-                                       v = new UIntConstant (res);
+                                       v = new UIntConstant (res, left.Location);
                                        if (result_type == null)
                                                return v;
                                        else
@@ -293,7 +291,7 @@ namespace Mono.CSharp {
                                        LongConstant v;
                                        long res = ((LongConstant)left).Value & ((LongConstant)right).Value;
                                        
-                                       v = new LongConstant (res);
+                                       v = new LongConstant (res, left.Location);
                                        if (result_type == null)
                                                return v;
                                        else
@@ -303,7 +301,7 @@ namespace Mono.CSharp {
                                        ulong res = ((ULongConstant)left).Value &
                                                ((ULongConstant)right).Value;
                                        
-                                       v = new ULongConstant (res);
+                                       v = new ULongConstant (res, left.Location);
                                        if (result_type == null)
                                                return v;
                                        else
@@ -313,7 +311,7 @@ namespace Mono.CSharp {
                                        ushort res = (ushort) (((UShortConstant)left).Value &
                                                               ((UShortConstant)right).Value);
                                        
-                                       v = new UShortConstant (res);
+                                       v = new UShortConstant (res, left.Location);
                                        if (result_type == null)
                                                return v;
                                        else
@@ -323,7 +321,7 @@ namespace Mono.CSharp {
                                        short res = (short) (((ShortConstant)left).Value &
                                                             ((ShortConstant)right).Value);
                                        
-                                       v = new ShortConstant (res);
+                                       v = new ShortConstant (res, left.Location);
                                        if (result_type == null)
                                                return v;
                                        else
@@ -340,7 +338,7 @@ namespace Mono.CSharp {
                                        IntConstant v;
                                        int res = ((IntConstant) left).Value ^ ((IntConstant) right).Value;
                                        
-                                       v = new IntConstant (res);
+                                       v = new IntConstant (res, left.Location);
                                        if (result_type == null)
                                                return v;
                                        else
@@ -349,7 +347,7 @@ namespace Mono.CSharp {
                                        UIntConstant v;
                                        uint res = ((UIntConstant)left).Value ^ ((UIntConstant)right).Value;
                                        
-                                       v = new UIntConstant (res);
+                                       v = new UIntConstant (res, left.Location);
                                        if (result_type == null)
                                                return v;
                                        else
@@ -358,7 +356,7 @@ namespace Mono.CSharp {
                                        LongConstant v;
                                        long res = ((LongConstant)left).Value ^ ((LongConstant)right).Value;
                                        
-                                       v = new LongConstant (res);
+                                       v = new LongConstant (res, left.Location);
                                        if (result_type == null)
                                                return v;
                                        else
@@ -368,7 +366,7 @@ namespace Mono.CSharp {
                                        ulong res = ((ULongConstant)left).Value ^
                                                ((ULongConstant)right).Value;
                                        
-                                       v = new ULongConstant (res);
+                                       v = new ULongConstant (res, left.Location);
                                        if (result_type == null)
                                                return v;
                                        else
@@ -378,7 +376,7 @@ namespace Mono.CSharp {
                                        ushort res = (ushort) (((UShortConstant)left).Value ^
                                                               ((UShortConstant)right).Value);
                                        
-                                       v = new UShortConstant (res);
+                                       v = new UShortConstant (res, left.Location);
                                        if (result_type == null)
                                                return v;
                                        else
@@ -388,7 +386,7 @@ namespace Mono.CSharp {
                                        short res = (short)(((ShortConstant)left).Value ^
                                                            ((ShortConstant)right).Value);
                                        
-                                       v = new ShortConstant (res);
+                                       v = new ShortConstant (res, left.Location);
                                        if (result_type == null)
                                                return v;
                                        else
@@ -410,7 +408,7 @@ namespace Mono.CSharp {
                                        if (left_is_string && right_is_string)
                                                return new StringConstant (
                                                        ((StringConstant) left).Value +
-                                                       ((StringConstant) right).Value);
+                                                       ((StringConstant) right).Value, left.Location);
                                        
                                        return null;
                                }
@@ -425,13 +423,17 @@ namespace Mono.CSharp {
                                        if (right is EnumConstant){
                                                return null;
                                        }
-                                       if (((EnumConstant) left).Child.Type != right.Type)
+
+                                       right = right.ToType (((EnumConstant) left).Child.Type, loc);
+                                       if (right == null)
                                                return null;
 
                                        wrap_as = left.Type;
                                } else if (right is EnumConstant){
-                                       if (((EnumConstant) right).Child.Type != left.Type)
+                                       left = left.ToType (((EnumConstant) right).Child.Type, loc);
+                                       if (left == null)
                                                return null;
+
                                        wrap_as = right.Type;
                                }
 
@@ -451,7 +453,7 @@ namespace Mono.CSharp {
                                                        res = unchecked (((DoubleConstant) left).Value +
                                                                         ((DoubleConstant) right).Value);
                                                
-                                               result = new DoubleConstant (res);
+                                               result = new DoubleConstant (res, left.Location);
                                        } else if (left is FloatConstant){
                                                float res;
                                                
@@ -462,7 +464,7 @@ namespace Mono.CSharp {
                                                        res = unchecked (((FloatConstant) left).Value +
                                                                         ((FloatConstant) right).Value);
                                                
-                                               result = new FloatConstant (res);
+                                               result = new FloatConstant (res, left.Location);
                                        } else if (left is ULongConstant){
                                                ulong res;
                                                
@@ -473,7 +475,7 @@ namespace Mono.CSharp {
                                                        res = unchecked (((ULongConstant) left).Value +
                                                                         ((ULongConstant) right).Value);
 
-                                               result = new ULongConstant (res);
+                                               result = new ULongConstant (res, left.Location);
                                        } else if (left is LongConstant){
                                                long res;
                                                
@@ -484,7 +486,7 @@ namespace Mono.CSharp {
                                                        res = unchecked (((LongConstant) left).Value +
                                                                         ((LongConstant) right).Value);
                                                
-                                               result = new LongConstant (res);
+                                               result = new LongConstant (res, left.Location);
                                        } else if (left is UIntConstant){
                                                uint res;
                                                
@@ -495,7 +497,7 @@ namespace Mono.CSharp {
                                                        res = unchecked (((UIntConstant) left).Value +
                                                                         ((UIntConstant) right).Value);
                                                
-                                               result = new UIntConstant (res);
+                                               result = new UIntConstant (res, left.Location);
                                        } else if (left is IntConstant){
                                                int res;
 
@@ -506,16 +508,27 @@ namespace Mono.CSharp {
                                                        res = unchecked (((IntConstant) left).Value +
                                                                         ((IntConstant) right).Value);
 
-                                               result = new IntConstant (res);
+                                               result = new IntConstant (res, left.Location);
+                                       } else if (left is DecimalConstant) {
+                                               decimal res;
+
+                                               if (ec.ConstantCheckState)
+                                                       res = checked (((DecimalConstant) left).Value +
+                                                               ((DecimalConstant) right).Value);
+                                               else
+                                                       res = unchecked (((DecimalConstant) left).Value +
+                                                               ((DecimalConstant) right).Value);
+
+                                               result = new DecimalConstant (res, left.Location);
                                        } else {
-                                               throw new Exception ( "Unexepected input: " + left);
+                                               throw new Exception ( "Unexepected addition input: " + left);
                                        }
                                } catch (OverflowException){
                                        Error_CompileTimeOverflow (loc);
                                }
 
                                if (wrap_as != null)
-                                       return new EnumConstant (result, wrap_as);
+                                       return result.TryReduce (ec, wrap_as, loc);
                                else
                                        return result;
 
@@ -528,18 +541,32 @@ namespace Mono.CSharp {
                                wrap_as = null;
                                if (left is EnumConstant){
                                        if (right is EnumConstant){
-                                               if (left.Type == right.Type)
-                                                       wrap_as = TypeManager.EnumToUnderlying (left.Type);
-                                               else
+                                               if (left.Type != right.Type) {
+                                                       Binary.Error_OperatorCannotBeApplied (loc, "-", left.Type, right.Type);
+                                                       return null;
+                                               }
+
+                                               wrap_as = TypeManager.EnumToUnderlying (left.Type);
+                                               right = ((EnumConstant) right).Child.ToType (wrap_as, loc);
+                                               if (right == null)
+                                                       return null;
+
+                                               left = ((EnumConstant) left).Child.ToType (wrap_as, loc);
+                                               if (left == null)
                                                        return null;
                                        }
-                                       if (((EnumConstant) left).Child.Type != right.Type)
-                                               return null;
+                                       else {
+                                               right = right.ToType (((EnumConstant) left).Child.Type, loc);
+                                               if (right == null)
+                                                       return null;
 
-                                       wrap_as = left.Type;
+                                               wrap_as = left.Type;
+                                       }
                                } else if (right is EnumConstant){
-                                       if (((EnumConstant) right).Child.Type != left.Type)
+                                       left = left.ToType (((EnumConstant) right).Child.Type, loc);
+                                       if (left == null)
                                                return null;
+
                                        wrap_as = right.Type;
                                }
 
@@ -558,7 +585,7 @@ namespace Mono.CSharp {
                                                        res = unchecked (((DoubleConstant) left).Value -
                                                                         ((DoubleConstant) right).Value);
                                                
-                                               result = new DoubleConstant (res);
+                                               result = new DoubleConstant (res, left.Location);
                                        } else if (left is FloatConstant){
                                                float res;
                                                
@@ -569,7 +596,7 @@ namespace Mono.CSharp {
                                                        res = unchecked (((FloatConstant) left).Value -
                                                                         ((FloatConstant) right).Value);
                                                
-                                               result = new FloatConstant (res);
+                                               result = new FloatConstant (res, left.Location);
                                        } else if (left is ULongConstant){
                                                ulong res;
                                                
@@ -580,7 +607,7 @@ namespace Mono.CSharp {
                                                        res = unchecked (((ULongConstant) left).Value -
                                                                         ((ULongConstant) right).Value);
                                                
-                                               result = new ULongConstant (res);
+                                               result = new ULongConstant (res, left.Location);
                                        } else if (left is LongConstant){
                                                long res;
                                                
@@ -591,7 +618,7 @@ namespace Mono.CSharp {
                                                        res = unchecked (((LongConstant) left).Value -
                                                                         ((LongConstant) right).Value);
                                                
-                                               result = new LongConstant (res);
+                                               result = new LongConstant (res, left.Location);
                                        } else if (left is UIntConstant){
                                                uint res;
                                                
@@ -602,7 +629,7 @@ namespace Mono.CSharp {
                                                        res = unchecked (((UIntConstant) left).Value -
                                                                         ((UIntConstant) right).Value);
                                                
-                                               result = new UIntConstant (res);
+                                               result = new UIntConstant (res, left.Location);
                                        } else if (left is IntConstant){
                                                int res;
 
@@ -613,17 +640,29 @@ namespace Mono.CSharp {
                                                        res = unchecked (((IntConstant) left).Value -
                                                                         ((IntConstant) right).Value);
 
-                                               result = new IntConstant (res);
+                                               result = new IntConstant (res, left.Location);
+                                       } else if (left is DecimalConstant) {
+                                               decimal res;
+
+                                               if (ec.ConstantCheckState)
+                                                       res = checked (((DecimalConstant) left).Value -
+                                                               ((DecimalConstant) right).Value);
+                                               else
+                                                       res = unchecked (((DecimalConstant) left).Value -
+                                                               ((DecimalConstant) right).Value);
+
+                                               return new DecimalConstant (res, left.Location);
                                        } else {
-                                               throw new Exception ( "Unexepected input: " + left);
+                                               throw new Exception ( "Unexepected subtraction input: " + left);
                                        }
                                } catch (OverflowException){
                                        Error_CompileTimeOverflow (loc);
                                }
+
                                if (wrap_as != null)
-                                       return new EnumConstant (result, wrap_as);
-                               else
-                                       return result;
+                                       return result.TryReduce (ec, wrap_as, loc);
+
+                               return result;
                                
                        case Binary.Operator.Multiply:
                                DoConstantNumericPromotions (ec, oper, ref left, ref right, loc);
@@ -636,69 +675,80 @@ namespace Mono.CSharp {
                                                
                                                if (ec.ConstantCheckState)
                                                        res = checked (((DoubleConstant) left).Value *
-                                                                      ((DoubleConstant) right).Value);
+                                                               ((DoubleConstant) right).Value);
                                                else
                                                        res = unchecked (((DoubleConstant) left).Value *
-                                                                        ((DoubleConstant) right).Value);
+                                                               ((DoubleConstant) right).Value);
                                                
-                                               return new DoubleConstant (res);
+                                               return new DoubleConstant (res, left.Location);
                                        } else if (left is FloatConstant){
                                                float res;
                                                
                                                if (ec.ConstantCheckState)
                                                        res = checked (((FloatConstant) left).Value *
-                                                                      ((FloatConstant) right).Value);
+                                                               ((FloatConstant) right).Value);
                                                else
                                                        res = unchecked (((FloatConstant) left).Value *
-                                                                        ((FloatConstant) right).Value);
+                                                               ((FloatConstant) right).Value);
                                                
-                                               return new FloatConstant (res);
+                                               return new FloatConstant (res, left.Location);
                                        } else if (left is ULongConstant){
                                                ulong res;
                                                
                                                if (ec.ConstantCheckState)
                                                        res = checked (((ULongConstant) left).Value *
-                                                                      ((ULongConstant) right).Value);
+                                                               ((ULongConstant) right).Value);
                                                else
                                                        res = unchecked (((ULongConstant) left).Value *
-                                                                        ((ULongConstant) right).Value);
+                                                               ((ULongConstant) right).Value);
                                                
-                                               return new ULongConstant (res);
+                                               return new ULongConstant (res, left.Location);
                                        } else if (left is LongConstant){
                                                long res;
                                                
                                                if (ec.ConstantCheckState)
                                                        res = checked (((LongConstant) left).Value *
-                                                                      ((LongConstant) right).Value);
+                                                               ((LongConstant) right).Value);
                                                else
                                                        res = unchecked (((LongConstant) left).Value *
-                                                                        ((LongConstant) right).Value);
+                                                               ((LongConstant) right).Value);
                                                
-                                               return new LongConstant (res);
+                                               return new LongConstant (res, left.Location);
                                        } else if (left is UIntConstant){
                                                uint res;
                                                
                                                if (ec.ConstantCheckState)
                                                        res = checked (((UIntConstant) left).Value *
-                                                                      ((UIntConstant) right).Value);
+                                                               ((UIntConstant) right).Value);
                                                else
                                                        res = unchecked (((UIntConstant) left).Value *
-                                                                        ((UIntConstant) right).Value);
+                                                               ((UIntConstant) right).Value);
                                                
-                                               return new UIntConstant (res);
+                                               return new UIntConstant (res, left.Location);
                                        } else if (left is IntConstant){
                                                int res;
 
                                                if (ec.ConstantCheckState)
                                                        res = checked (((IntConstant) left).Value *
-                                                                      ((IntConstant) right).Value);
+                                                               ((IntConstant) right).Value);
                                                else
                                                        res = unchecked (((IntConstant) left).Value *
-                                                                        ((IntConstant) right).Value);
+                                                               ((IntConstant) right).Value);
+
+                                               return new IntConstant (res, left.Location);
+                                       } else if (left is DecimalConstant) {
+                                               decimal res;
 
-                                               return new IntConstant (res);
+                                               if (ec.ConstantCheckState)
+                                                       res = checked (((DecimalConstant) left).Value *
+                                                               ((DecimalConstant) right).Value);
+                                               else
+                                                       res = unchecked (((DecimalConstant) left).Value *
+                                                               ((DecimalConstant) right).Value);
+
+                                               return new DecimalConstant (res, left.Location);
                                        } else {
-                                               throw new Exception ( "Unexepected input: " + left);
+                                               throw new Exception ( "Unexepected multiply input: " + left);
                                        }
                                } catch (OverflowException){
                                        Error_CompileTimeOverflow (loc);
@@ -716,69 +766,80 @@ namespace Mono.CSharp {
                                                
                                                if (ec.ConstantCheckState)
                                                        res = checked (((DoubleConstant) left).Value /
-                                                                      ((DoubleConstant) right).Value);
+                                                               ((DoubleConstant) right).Value);
                                                else
                                                        res = unchecked (((DoubleConstant) left).Value /
-                                                                        ((DoubleConstant) right).Value);
+                                                               ((DoubleConstant) right).Value);
                                                
-                                               return new DoubleConstant (res);
+                                               return new DoubleConstant (res, left.Location);
                                        } else if (left is FloatConstant){
                                                float res;
                                                
                                                if (ec.ConstantCheckState)
                                                        res = checked (((FloatConstant) left).Value /
-                                                                      ((FloatConstant) right).Value);
+                                                               ((FloatConstant) right).Value);
                                                else
                                                        res = unchecked (((FloatConstant) left).Value /
-                                                                        ((FloatConstant) right).Value);
+                                                               ((FloatConstant) right).Value);
                                                
-                                               return new FloatConstant (res);
+                                               return new FloatConstant (res, left.Location);
                                        } else if (left is ULongConstant){
                                                ulong res;
                                                
                                                if (ec.ConstantCheckState)
                                                        res = checked (((ULongConstant) left).Value /
-                                                                      ((ULongConstant) right).Value);
+                                                               ((ULongConstant) right).Value);
                                                else
                                                        res = unchecked (((ULongConstant) left).Value /
-                                                                        ((ULongConstant) right).Value);
+                                                               ((ULongConstant) right).Value);
                                                
-                                               return new ULongConstant (res);
+                                               return new ULongConstant (res, left.Location);
                                        } else if (left is LongConstant){
                                                long res;
                                                
                                                if (ec.ConstantCheckState)
                                                        res = checked (((LongConstant) left).Value /
-                                                                      ((LongConstant) right).Value);
+                                                               ((LongConstant) right).Value);
                                                else
                                                        res = unchecked (((LongConstant) left).Value /
-                                                                        ((LongConstant) right).Value);
+                                                               ((LongConstant) right).Value);
                                                
-                                               return new LongConstant (res);
+                                               return new LongConstant (res, left.Location);
                                        } else if (left is UIntConstant){
                                                uint res;
                                                
                                                if (ec.ConstantCheckState)
                                                        res = checked (((UIntConstant) left).Value /
-                                                                      ((UIntConstant) right).Value);
+                                                               ((UIntConstant) right).Value);
                                                else
                                                        res = unchecked (((UIntConstant) left).Value /
-                                                                        ((UIntConstant) right).Value);
+                                                               ((UIntConstant) right).Value);
                                                
-                                               return new UIntConstant (res);
+                                               return new UIntConstant (res, left.Location);
                                        } else if (left is IntConstant){
                                                int res;
 
                                                if (ec.ConstantCheckState)
                                                        res = checked (((IntConstant) left).Value /
-                                                                      ((IntConstant) right).Value);
+                                                               ((IntConstant) right).Value);
                                                else
                                                        res = unchecked (((IntConstant) left).Value /
-                                                                        ((IntConstant) right).Value);
+                                                               ((IntConstant) right).Value);
+
+                                               return new IntConstant (res, left.Location);
+                                       } else if (left is DecimalConstant) {
+                                               decimal res;
+
+                                               if (ec.ConstantCheckState)
+                                                       res = checked (((DecimalConstant) left).Value /
+                                                               ((DecimalConstant) right).Value);
+                                               else
+                                                       res = unchecked (((DecimalConstant) left).Value /
+                                                               ((DecimalConstant) right).Value);
 
-                                               return new IntConstant (res);
+                                               return new DecimalConstant (res, left.Location);
                                        } else {
-                                               throw new Exception ( "Unexepected input: " + left);
+                                               throw new Exception ( "Unexepected division input: " + left);
                                        }
                                } catch (OverflowException){
                                        Error_CompileTimeOverflow (loc);
@@ -805,7 +866,7 @@ namespace Mono.CSharp {
                                                        res = unchecked (((DoubleConstant) left).Value %
                                                                         ((DoubleConstant) right).Value);
                                                
-                                               return new DoubleConstant (res);
+                                               return new DoubleConstant (res, left.Location);
                                        } else if (left is FloatConstant){
                                                float res;
                                                
@@ -816,7 +877,7 @@ namespace Mono.CSharp {
                                                        res = unchecked (((FloatConstant) left).Value %
                                                                         ((FloatConstant) right).Value);
                                                
-                                               return new FloatConstant (res);
+                                               return new FloatConstant (res, left.Location);
                                        } else if (left is ULongConstant){
                                                ulong res;
                                                
@@ -827,7 +888,7 @@ namespace Mono.CSharp {
                                                        res = unchecked (((ULongConstant) left).Value %
                                                                         ((ULongConstant) right).Value);
                                                
-                                               return new ULongConstant (res);
+                                               return new ULongConstant (res, left.Location);
                                        } else if (left is LongConstant){
                                                long res;
                                                
@@ -838,7 +899,7 @@ namespace Mono.CSharp {
                                                        res = unchecked (((LongConstant) left).Value %
                                                                         ((LongConstant) right).Value);
                                                
-                                               return new LongConstant (res);
+                                               return new LongConstant (res, left.Location);
                                        } else if (left is UIntConstant){
                                                uint res;
                                                
@@ -849,7 +910,7 @@ namespace Mono.CSharp {
                                                        res = unchecked (((UIntConstant) left).Value %
                                                                         ((UIntConstant) right).Value);
                                                
-                                               return new UIntConstant (res);
+                                               return new UIntConstant (res, left.Location);
                                        } else if (left is IntConstant){
                                                int res;
 
@@ -860,9 +921,9 @@ namespace Mono.CSharp {
                                                        res = unchecked (((IntConstant) left).Value %
                                                                         ((IntConstant) right).Value);
 
-                                               return new IntConstant (res);
+                                               return new IntConstant (res, left.Location);
                                        } else {
-                                               throw new Exception ( "Unexepected input: " + left);
+                                               throw new Exception ( "Unexepected modulus input: " + left);
                                        }
                                } catch (DivideByZeroException){
                                        Report.Error (020, loc, "Division by constant zero");
@@ -884,19 +945,19 @@ namespace Mono.CSharp {
 
                                IntConstant lic;
                                if ((lic = left.ConvertToInt ()) != null)
-                                       return new IntConstant (lic.Value << lshift_val);
+                                       return new IntConstant (lic.Value << lshift_val, left.Location);
 
                                UIntConstant luic;
                                if ((luic = left.ConvertToUInt ()) != null)
-                                       return new UIntConstant (luic.Value << lshift_val);
+                                       return new UIntConstant (luic.Value << lshift_val, left.Location);
 
                                LongConstant llc;
                                if ((llc = left.ConvertToLong ()) != null)
-                                       return new LongConstant (llc.Value << lshift_val);
+                                       return new LongConstant (llc.Value << lshift_val, left.Location);
 
                                ULongConstant lulc;
                                if ((lulc = left.ConvertToULong ()) != null)
-                                       return new ULongConstant (lulc.Value << lshift_val);
+                                       return new ULongConstant (lulc.Value << lshift_val, left.Location);
 
                                Binary.Error_OperatorCannotBeApplied (loc, "<<", lt, rt);
                                break;
@@ -914,19 +975,19 @@ namespace Mono.CSharp {
 
                                IntConstant ric;
                                if ((ric = left.ConvertToInt ()) != null)
-                                       return new IntConstant (ric.Value >> rshift_val);
+                                       return new IntConstant (ric.Value >> rshift_val, left.Location);
 
                                UIntConstant ruic;
                                if ((ruic = left.ConvertToUInt ()) != null)
-                                       return new UIntConstant (ruic.Value >> rshift_val);
+                                       return new UIntConstant (ruic.Value >> rshift_val, left.Location);
 
                                LongConstant rlc;
                                if ((rlc = left.ConvertToLong ()) != null)
-                                       return new LongConstant (rlc.Value >> rshift_val);
+                                       return new LongConstant (rlc.Value >> rshift_val, left.Location);
 
                                ULongConstant rulc;
                                if ((rulc = left.ConvertToULong ()) != null)
-                                       return new ULongConstant (rulc.Value >> rshift_val);
+                                       return new ULongConstant (rulc.Value >> rshift_val, left.Location);
 
                                Binary.Error_OperatorCannotBeApplied (loc, ">>", lt, rt);
                                break;
@@ -935,7 +996,7 @@ namespace Mono.CSharp {
                                if (left is BoolConstant && right is BoolConstant){
                                        return new BoolConstant (
                                                ((BoolConstant) left).Value &&
-                                               ((BoolConstant) right).Value);
+                                               ((BoolConstant) right).Value, left.Location);
                                }
                                break;
 
@@ -943,7 +1004,7 @@ namespace Mono.CSharp {
                                if (left is BoolConstant && right is BoolConstant){
                                        return new BoolConstant (
                                                ((BoolConstant) left).Value ||
-                                               ((BoolConstant) right).Value);
+                                               ((BoolConstant) right).Value, left.Location);
                                }
                                break;
                                
@@ -951,16 +1012,29 @@ namespace Mono.CSharp {
                                if (left is BoolConstant && right is BoolConstant){
                                        return new BoolConstant (
                                                ((BoolConstant) left).Value ==
-                                               ((BoolConstant) right).Value);
+                                               ((BoolConstant) right).Value, left.Location);
                                
                                }
+                               if (left is NullLiteral){
+                                       if (right is NullLiteral)
+                                               return new BoolConstant (true, left.Location);
+                                       else if (right is StringConstant)
+                                               return new BoolConstant (
+                                                       ((StringConstant) right).Value == null, left.Location);
+                               } else if (right is NullLiteral){
+                                       if (left is NullLiteral)
+                                               return new BoolConstant (true, left.Location);
+                                       else if (left is StringConstant)
+                                               return new BoolConstant (
+                                                       ((StringConstant) left).Value == null, left.Location);
+                               }
                                if (left is StringConstant && right is StringConstant){
                                        return new BoolConstant (
                                                ((StringConstant) left).Value ==
-                                               ((StringConstant) right).Value);
+                                               ((StringConstant) right).Value, left.Location);
                                        
                                }
-                               
+
                                DoConstantNumericPromotions (ec, oper, ref left, ref right, loc);
                                if (left == null || right == null)
                                        return null;
@@ -987,18 +1061,31 @@ namespace Mono.CSharp {
                                else
                                        return null;
 
-                               return new BoolConstant (bool_res);
+                               return new BoolConstant (bool_res, left.Location);
 
                        case Binary.Operator.Inequality:
                                if (left is BoolConstant && right is BoolConstant){
                                        return new BoolConstant (
                                                ((BoolConstant) left).Value !=
-                                               ((BoolConstant) right).Value);
+                                               ((BoolConstant) right).Value, left.Location);
+                               }
+                               if (left is NullLiteral){
+                                       if (right is NullLiteral)
+                                               return new BoolConstant (false, left.Location);
+                                       else if (right is StringConstant)
+                                               return new BoolConstant (
+                                                       ((StringConstant) right).Value != null, left.Location);
+                               } else if (right is NullLiteral){
+                                       if (left is NullLiteral)
+                                               return new BoolConstant (false, left.Location);
+                                       else if (left is StringConstant)
+                                               return new BoolConstant (
+                                                       ((StringConstant) left).Value != null, left.Location);
                                }
                                if (left is StringConstant && right is StringConstant){
                                        return new BoolConstant (
                                                ((StringConstant) left).Value !=
-                                               ((StringConstant) right).Value);
+                                               ((StringConstant) right).Value, left.Location);
                                        
                                }
                                DoConstantNumericPromotions (ec, oper, ref left, ref right, loc);
@@ -1027,7 +1114,7 @@ namespace Mono.CSharp {
                                else
                                        return null;
 
-                               return new BoolConstant (bool_res);
+                               return new BoolConstant (bool_res, left.Location);
 
                        case Binary.Operator.LessThan:
                                DoConstantNumericPromotions (ec, oper, ref left, ref right, loc);
@@ -1056,7 +1143,7 @@ namespace Mono.CSharp {
                                else
                                        return null;
 
-                               return new BoolConstant (bool_res);
+                               return new BoolConstant (bool_res, left.Location);
                                
                        case Binary.Operator.GreaterThan:
                                DoConstantNumericPromotions (ec, oper, ref left, ref right, loc);
@@ -1085,7 +1172,7 @@ namespace Mono.CSharp {
                                else
                                        return null;
 
-                               return new BoolConstant (bool_res);
+                               return new BoolConstant (bool_res, left.Location);
 
                        case Binary.Operator.GreaterThanOrEqual:
                                DoConstantNumericPromotions (ec, oper, ref left, ref right, loc);
@@ -1114,7 +1201,7 @@ namespace Mono.CSharp {
                                else
                                        return null;
 
-                               return new BoolConstant (bool_res);
+                               return new BoolConstant (bool_res, left.Location);
 
                        case Binary.Operator.LessThanOrEqual:
                                DoConstantNumericPromotions (ec, oper, ref left, ref right, loc);
@@ -1143,7 +1230,7 @@ namespace Mono.CSharp {
                                else
                                        return null;
 
-                               return new BoolConstant (bool_res);
+                               return new BoolConstant (bool_res, left.Location);
                        }
                                        
                        return null;