[mcs] Initial by ref returns and variables support

[mono.git] / mcs / mcs / lambda.cs

diff --git a/mcs/mcs/lambda.cs b/mcs/mcs/lambda.cs
index 2fba7ed4738c3129f1d2fac536922d66afc74c43..360c5c9463002d0d8e1956573bfcb688702589e4 100644 (file)
--- a/mcs/mcs/lambda.cs
+++ b/mcs/mcs/lambda.cs
@@ -65,7 +65,7 @@ namespace Mono.CSharp {
                        AParametersCollection d_params = Delegate.GetParameters (delegateType);
 
                        if (HasExplicitParameters) {
-                               if (!VerifyExplicitParameters (ec, delegateType, d_params))
+                               if (!VerifyExplicitParameters (ec, tic, delegateType, d_params))
                                        return null;
 
                                return Parameters;
@@ -75,7 +75,7 @@ namespace Mono.CSharp {
                        // If L has an implicitly typed parameter list we make implicit parameters explicit
                        // Set each parameter of L is given the type of the corresponding parameter in D
                        //
-                       if (!VerifyParameterCompatibility (ec, delegateType, d_params, ec.IsInProbingMode))
+                       if (!VerifyParameterCompatibility (ec, tic, delegateType, d_params, ec.IsInProbingMode))
                                return null;
 
                        TypeSpec [] ptypes = new TypeSpec [Parameters.Count];
@@ -182,16 +182,21 @@ namespace Mono.CSharp {
                ExpressionStatement statement;
 
                public ContextualReturn (Expression expr)
-                       : base (expr, expr.Location)
+                       : base (expr, expr.StartLocation)
                {
                }
 
                public override Expression CreateExpressionTree (ResolveContext ec)
                {
+                       if (Expr is ReferenceExpression) {
+                               ec.Report.Error (8155, Expr.Location, "Lambda expressions that return by reference cannot be converted to expression trees");
+                               return null;
+                       }
+
                        return Expr.CreateExpressionTree (ec);
                }
 
-               public override void Emit (EmitContext ec)
+               protected override void DoEmit (EmitContext ec)
                {
                        if (statement != null) {
                                statement.EmitStatement (ec);
@@ -203,7 +208,7 @@ namespace Mono.CSharp {
                                return;
                        }
 
-                       base.Emit (ec);
+                       base.DoEmit (ec);
                }
 
                protected override bool DoResolve (BlockContext ec)
@@ -216,9 +221,21 @@ namespace Mono.CSharp {
                                if (Expr == null)
                                        return false;
 
+                               if (Expr is ReferenceExpression) {
+                                       // CSC: should be different error code
+                                       ec.Report.Error (8149, loc, "By-reference returns can only be used in lambda expressions that return by reference");
+                                       return false;
+                               }
+
                                statement = Expr as ExpressionStatement;
-                               if (statement == null)
-                                       Expr.Error_InvalidExpressionStatement (ec);
+                               if (statement == null) {
+                                       var reduced = Expr as IReducedExpressionStatement;
+                                       if (reduced != null) {
+                                               statement = EmptyExpressionStatement.Instance;
+                                       } else {
+                                               Expr.Error_InvalidExpressionStatement (ec);
+                                       }
+                               }
 
                                return true;
                        }