2005-07-06 Martin Baulig <martin@ximian.com>

[mono.git] / mcs / gmcs / assign.cs

diff --git a/mcs/gmcs/assign.cs b/mcs/gmcs/assign.cs
old mode 100755 (executable)
new mode 100644 (file)
index cf60089..b4b75fb
--- a/mcs/gmcs/assign.cs
+++ b/mcs/gmcs/assign.cs
@@ -3,9 +3,10 @@
 //
 // Author:
 //   Miguel de Icaza (miguel@ximian.com)
-//   Martin Baulig (martin@gnome.org)
+//   Martin Baulig (martin@ximian.com)
 //
 // (C) 2001, 2002, 2003 Ximian, Inc.
+// (C) 2004 Novell, Inc
 //
 using System;
 using System.Reflection;
@@ -312,8 +313,11 @@ namespace Mono.CSharp {
                                source = embedded = ((Assign) source).GetEmbeddedAssign (loc);
 
                        real_source = source = source.Resolve (ec);
-                       if (source == null)
+                       if (source == null) {
+                               // Ensure that we don't propagate the error as spurious "uninitialized variable" errors.
+                               target = target.ResolveLValue (ec, EmptyExpression.Null, Location);
                                return null;
+                       }
 
                        //
                        // This is used in an embedded assignment.
@@ -344,11 +348,15 @@ namespace Mono.CSharp {
                        if (embedded != null)
                                source = (embedded.temp != null) ? embedded.temp : embedded.source;
 
-                       target = target.ResolveLValue (ec, source);
+                       target = target.ResolveLValue (ec, source, Location);
 
                        if (target == null)
                                return null;
 
+                       if (source.Equals (target)) {
+                               Report.Warning (1717, 3, loc, "Assignment made to same variable; did you mean to assign something else?");
+                       }
+
                        Type target_type = target.Type;
                        Type source_type = real_source.Type;
 
@@ -386,6 +394,21 @@ namespace Mono.CSharp {
                                }
                        }
 
+                       FieldExpr field_exp = target as FieldExpr;
+                       if (field_exp != null && field_exp.DeclaringType.IsValueType && !ec.IsConstructor && !ec.IsFieldInitializer) {
+                               field_exp = field_exp.InstanceExpression as FieldExpr;
+                               if (field_exp != null && field_exp.FieldInfo.IsInitOnly) {
+                                       if (field_exp.IsStatic) {
+                                               Report.Error (1650, loc, "Members of static readonly field '{0}' cannot be assigned to " +
+                                                       "(except in a static constructor or a variable initializer)", TypeManager.GetFullNameSignature (field_exp.FieldInfo));
+                                       } else {
+                                               Report.Error (1648, loc, "Members of readonly field '{0}' cannot be assigned to " +
+                                                       "(except in a constructor or a variable initializer)", TypeManager.GetFullNameSignature (field_exp.FieldInfo));
+                                       }
+                                       return null;
+                               }
+                       }
+
                        if (!(target is IAssignMethod) && (target.eclass != ExprClass.EventAccess)) {
                                Report.Error (131, loc,
                                              "Left hand of an assignment must be a variable, " +