[Mono-bugs] [Bug 50839][Nor] New - typeof(void) in attribute parameters

[bugzilla-daemon@bugzilla.ximian.com]

Please do not reply to this email- if you want to comment on the bug, go to the
URL shown below and enter your comments there.

Changed by shugo@ruby-lang.org.

http://bugzilla.ximian.com/show_bug.cgi?id=50839

--- shadow/50839	2003-11-11 22:12:02.000000000 -0500
+++ shadow/50839.tmp.20365	2003-11-11 22:12:02.000000000 -0500
@@ -0,0 +1,184 @@
+Bug#: 50839
+Product: Mono/MCS
+Version: unspecified
+OS: GNU/Linux [Other]
+OS Details: Debian Sid
+Status: NEW   
+Resolution: 
+Severity: 
+Priority: Normal
+Component: Misc
+AssignedTo: mono-bugs@ximian.com                            
+ReportedBy: shugo@ruby-lang.org               
+QAContact: mono-bugs@ximian.com
+TargetMilestone: ---
+URL: 
+Cc: 
+Summary: typeof(void) in attribute parameters
+
+Please fill in this template when reporting a bug, unless you know what you
+are doing.
+Description of Problem:
+
+
+Steps to reproduce the problem:
+1. compile test.cs
+
+$ cat test.cs
+using System;
+
+public class TestAttribute : Attribute {
+    Type type;
+
+    public TestAttribute(Type type)
+    {
+        this.type = type;
+    }
+
+    public Type Type
+    {
+        get { return type; }
+    }
+}
+
+[TestAttribute(typeof(void))]
+public class Test {
+    public static void Main()
+    {
+        object[] attrs =
+            typeof(Test).GetCustomAttributes(typeof(TestAttribute), false);
+        foreach (TestAttribute attr in attrs) {
+            Console.WriteLine("TestAttribute({0})", attr.Type);
+        }
+    }
+}
+$ mcs test.cs
+
+Actual Results:
+
+$ mcs test.cs
+test.cs(17) error CS0182: An attribute argument must be a constant
+expression, typeof expression or array creation expression
+Compilation failed: 1 error(s), 0 warnings
+
+Expected Results:
+
+$ mcs test.cs
+Compilation succeeded
+$ ./test.exe
+TestAttribute(System.Void)
+
+How often does this happen? 
+
+Everytime.
+
+Additional Information:
+
+The following patch solves the problem.
+
+Index: mcs/attribute.cs
+===================================================================
+RCS file: /mono/mcs/mcs/attribute.cs,v
+retrieving revision 1.98
+diff -u -r1.98 attribute.cs
+--- mcs/attribute.cs	7 Nov 2003 07:01:27 -0000	1.98
++++ mcs/attribute.cs	12 Nov 2003 02:49:23 -0000
+@@ -137,8 +137,8 @@
+ 			if (e is Constant) {
+
+ 				result = ((Constant) e).GetValue ();
+
+ 				return true;
+
+-			} else if (e is TypeOf) {
+
+-				result = ((TypeOf) e).TypeArg;
+
++			} else if (e is ITypeOf) {
+
++				result = ((ITypeOf) e).TypeArg;
+
+ 				return true;
+
+ 			} else if (e is ArrayCreation){
+
+ 				result =  ((ArrayCreation) e).EncodeAsAttribute ();
+
+@@ -293,8 +293,8 @@
+ 								this.Inherited = (bool) o;
+
+ 						}
+
+ 						
+
+-					} else if (e is TypeOf) {
+
+-						prop_values.Add (((TypeOf) e).TypeArg);
+
++					} else if (e is ITypeOf) {
+
++						prop_values.Add (((ITypeOf) e).TypeArg);
+
+ 					} else {
+
+ 						Error_AttributeArgumentNotValid (Location);
+
+ 						return null;
+
+@@ -318,8 +318,8 @@
+ 						object value = ((Constant) e).GetValue ();
+
+ 						
+
+ 						field_values.Add (value);
+
+-					} else if (e is TypeOf) {
+
+-						field_values.Add (((TypeOf) e).TypeArg);
+
++					} else if (e is ITypeOf) {
+
++						field_values.Add (((ITypeOf) e).TypeArg);
+
+ 					} else {
+
+ 						Error_AttributeArgumentNotValid (Location);
+
+ 						return null;
+
+Index: mcs/expression.cs
+===================================================================
+RCS file: /mono/mcs/mcs/expression.cs,v
+retrieving revision 1.497
+diff -u -r1.497 expression.cs
+--- mcs/expression.cs	8 Nov 2003 14:49:03 -0000	1.497
++++ mcs/expression.cs	12 Nov 2003 02:49:28 -0000
+@@ -6425,11 +6425,18 @@
+ 			ec.ig.Emit (OpCodes.Ldarg_0);
+ 		}
+ 	}
++
++	/// <summary>
++	///   This interface is implemented by typeof
++	/// </summary>
++	public interface ITypeOf {
++            Type TypeArg { get; }
++	}
+ 	
+ 	/// <summary>
+ 	///   Implements the typeof operator
+ 	/// </summary>
+-	public class TypeOf : Expression {
++	public class TypeOf : Expression, ITypeOf {
+ 		public readonly Expression QueriedType;
+ 		Type typearg;
+ 		
+@@ -6471,7 +6478,7 @@
+ 	/// <summary>
+ 	///   Implements the `typeof (void)' operator
+ 	/// </summary>
+-	public class TypeOfVoid : Expression {
++	public class TypeOfVoid : Expression, ITypeOf {
+ 		public TypeOfVoid (Location l)
+ 		{
+ 			loc = l;