Avoid calling ILGenerator.Begin/EndScope on dynamic methods. Fixes is…

…sue #10.

Examples/Program.cs

@@ -152,7 +152,18 @@ static void Main(string[] args)
 		static void DynamicMethodExamples()
 		{
 			DynamicMethodGen dmg = DynamicMethodGen.Static(typeof(Program)).Method(typeof(void)).Parameter(typeof(string), "name");
-			dmg.GetCode().WriteLine("Hello {0}!", dmg.GetCode().Arg("name"));
+			CodeGen g = dmg.GetCode();
+			g.Try();
+			{
+				Operand name = g.Local(typeof(string), g.Arg("name"));
+				g.WriteLine("Hello {0}!", name);
+			}
+			g.CatchAll();
+			{
+				g.WriteLine("Error");
+			}
+			g.End();
+
 			DynamicMethod dm = dmg.GetCompletedDynamicMethod(true);
 
 			// reflection-style invocation

RunSharp/CodeGen.Statements.cs

@@ -615,7 +615,8 @@ public void EnsureScope()
 			{
 				if (!hasScope)
 				{
-					g.il.BeginScope();
+					if (g.context.SupportsScopes)
+						g.il.BeginScope();
 					hasScope = true;
 				}
 			}
@@ -624,7 +625,8 @@ protected void EndScope()
 			{
 				if (hasScope)
 				{
-					g.il.EndScope();
+					if (g.context.SupportsScopes)
+						g.il.EndScope();
 					hasScope = false;
 				}
 			}

RunSharp/CodeGen.cs

@@ -40,6 +40,7 @@ interface ICodeGenContext : IMemberInfo, ISignatureGen, IDelayedDefinition, IDel
 		ILGenerator GetILGenerator();
 
 		Type OwnerType { get; }
+		bool SupportsScopes { get; }
 	}
 
 	public partial class CodeGen

RunSharp/DynamicMethodGen.cs

@@ -29,7 +29,7 @@
 
 namespace TriAxis.RunSharp
 {
-	public sealed class DynamicMethodGen : RoutineGen<DynamicMethodGen>
+	public sealed class DynamicMethodGen : RoutineGen<DynamicMethodGen>, ICodeGenContext
 	{
 		Attributes attrs;
 		DynamicMethod dm;
@@ -173,5 +173,14 @@ protected override void SetCustomAttribute(CustomAttributeBuilder cab)
 		}
 
 		#endregion
+
+		#region ICodeGenContext Members
+
+		bool ICodeGenContext.SupportsScopes
+		{
+			get { return false; }
+		}
+
+		#endregion
 	}
 }

RunSharp/RoutineGen.cs

@@ -204,5 +204,14 @@ ILGenerator ICodeGenContext.GetILGenerator()
 		}
 
 		#endregion
+
+		#region ICodeGenContext Members
+
+		bool ICodeGenContext.SupportsScopes
+		{
+			get { return true; }
+		}
+
+		#endregion
 	}
 }