X-Git-Url: http://wien.tomnetworks.com/gitweb/?a=blobdiff_plain;f=mcs%2Fmcs%2Fnullable.cs;h=3c95d7689bd55fc94f68a5e5d619386e83e842b9;hb=5ad1099341581dee94f77b32db728918e90fa64f;hp=1732a9b9c5c46edda117e4104b1d1637ad617bda;hpb=e946a6cdebde729e1c03ec374184254ab38da184;p=mono.git

diff --git a/mcs/mcs/nullable.cs b/mcs/mcs/nullable.cs
index 1732a9b9c5c..3c95d7689bd 100644
--- a/mcs/mcs/nullable.cs
+++ b/mcs/mcs/nullable.cs
@@ -201,6 +201,11 @@ namespace Mono.CSharp.Nullable
 			return uw != null && expr.Equals (uw.expr);
 		}
 
+		public override void FlowAnalysis (FlowAnalysisContext fc)
+		{
+			expr.FlowAnalysis (fc);
+		}
+
 		public Expression Original {
 			get {
 				return expr;
@@ -480,6 +485,11 @@ namespace Mono.CSharp.Nullable
 			ec.MarkLabel (end_label);
 		}
 
+		public override void FlowAnalysis (FlowAnalysisContext fc)
+		{
+			expr.FlowAnalysis (fc);
+		}
+
 		public void AddressOf (EmitContext ec, AddressOp mode)
 		{
 			unwrap.AddressOf (ec, mode);
@@ -649,10 +659,10 @@ namespace Mono.CSharp.Nullable
 		{
 			if (rc.IsRuntimeBinder) {
 				if (UnwrapLeft == null && !Left.Type.IsNullableType)
-					Left = Wrap.Create (Left, rc.Module.PredefinedTypes.Nullable.TypeSpec.MakeGenericType (rc.Module, new[] { Left.Type }));
+					Left = LiftOperand (rc, Left);
 
 				if (UnwrapRight == null && !Right.Type.IsNullableType)
-					Right = Wrap.Create (Right, rc.Module.PredefinedTypes.Nullable.TypeSpec.MakeGenericType (rc.Module, new[] { Right.Type }));
+					Right = LiftOperand (rc, Right);
 			} else {
 				if (UnwrapLeft == null && Left != null && Left.Type.IsNullableType) {
 					Left = Unwrap.CreateUnwrapped (Left);
@@ -671,6 +681,21 @@ namespace Mono.CSharp.Nullable
 			return this;
 		}
 
+		Expression LiftOperand (ResolveContext rc, Expression expr)
+		{
+			TypeSpec type;
+			if (expr.IsNull) {
+				type = Left.IsNull ? Right.Type : Left.Type;
+			} else {
+				type = expr.Type;
+			}
+
+			if (!type.IsNullableType)
+				type = rc.Module.PredefinedTypes.Nullable.TypeSpec.MakeGenericType (rc.Module, new[] { type });
+
+			return Wrap.Create (expr, type);
+		}
+
 		public override void Emit (EmitContext ec)
 		{
 			if (IsBitwiseBoolean && UserOperator == null) {
@@ -1008,6 +1033,11 @@ namespace Mono.CSharp.Nullable
 			ec.MarkLabel (end_label);
 		}
 
+		public override void FlowAnalysis (FlowAnalysisContext fc)
+		{
+			Binary.FlowAnalysis (fc);
+		}
+
 		public override SLE.Expression MakeExpression (BuilderContext ctx)
 		{
 			return Binary.MakeExpression (ctx, Left, Right);
@@ -1221,6 +1251,14 @@ namespace Mono.CSharp.Nullable
 			ec.MarkLabel (end_label);
 		}
 
+		public override void FlowAnalysis (FlowAnalysisContext fc)
+		{
+			left.FlowAnalysis (fc);
+			var left_da = fc.BranchDefiniteAssignment ();
+			right.FlowAnalysis (fc);
+			fc.DefiniteAssignment = left_da;
+		}
+
 		protected override void CloneTo (CloneContext clonectx, Expression t)
 		{
 			NullCoalescingOperator target = (NullCoalescingOperator) t;