[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 0de7fe4bc9a0a0e57735c40e5a443f3b737cd384..360c5c9463002d0d8e1956573bfcb688702589e4 100644 (file)
--- a/mcs/mcs/lambda.cs
+++ b/mcs/mcs/lambda.cs
@@ -7,6 +7,7 @@
 // Dual licensed under the terms of the MIT X11 or GNU GPL
 //
 // Copyright 2007-2008 Novell, Inc
+// Copyright 2011 Xamarin Inc
 //
 
 #if STATIC
@@ -33,7 +34,7 @@ namespace Mono.CSharp {
                        if (ec.IsInProbingMode)
                                return this;
 
-                       BlockContext bc = new BlockContext (ec.MemberContext, ec.ConstructorBlock, TypeManager.void_type) {
+                       BlockContext bc = new BlockContext (ec.MemberContext, ec.ConstructorBlock, ec.BuiltinTypes.Void) {
                                CurrentAnonymousMethod = ec.CurrentAnonymousMethod
                        };
 
@@ -64,7 +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;
@@ -74,13 +75,13 @@ 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];
                        for (int i = 0; i < d_params.Count; i++) {
                                // D has no ref or out parameters
-                               if ((d_params.FixedParameters [i].ModFlags & Parameter.Modifier.ISBYREF) != 0)
+                               if ((d_params.FixedParameters[i].ModFlags & Parameter.Modifier.RefOutMask) != 0)
                                        return null;
 
                                TypeSpec d_param = d_params.Types [i];
@@ -89,7 +90,7 @@ namespace Mono.CSharp {
                                // When type inference context exists try to apply inferred type arguments
                                //
                                if (tic != null) {
-                                       d_param = tic.InflateGenericArgument (d_param);
+                                       d_param = tic.InflateGenericArgument (ec, d_param);
                                }
 
                                ptypes [i] = d_param;
@@ -123,6 +124,11 @@ namespace Mono.CSharp {
                {
                        return "lambda expression";
                }
+               
+               public override object Accept (StructuralVisitor visitor)
+               {
+                       return visitor.Visit (this);
+               }
        }
 
        class LambdaMethod : AnonymousMethodBody
@@ -176,24 +182,33 @@ 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);
-                               ec.Emit (OpCodes.Ret);
+                               if (unwind_protect)
+                                       ec.Emit (OpCodes.Leave, ec.CreateReturnLabel ());
+                               else {
+                                       ec.Emit (OpCodes.Ret);
+                               }
                                return;
                        }
 
-                       base.Emit (ec);
+                       base.DoEmit (ec);
                }
 
                protected override bool DoResolve (BlockContext ec)
@@ -201,14 +216,26 @@ namespace Mono.CSharp {
                        //
                        // When delegate returns void, only expression statements can be used
                        //
-                       if (ec.ReturnType == TypeManager.void_type) {
+                       if (ec.ReturnType.Kind == MemberKind.Void) {
                                Expr = Expr.Resolve (ec);
                                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;
                        }