Removed expiry propagation for Values.

It seems there were only two cases:
 - Values expiring when stack frame exits
 - Values expiring immediately when debuggee is resumed

These precisely correspond to these two cases: (respectively)
 - Values that have closed expression
 - Values that do not have closed expression


The new behaviour is that every value expires when debuggee is resumed.

Work in progress...

git-svn-id: svn://svn.sharpdevelop.net/sharpdevelop/trunk@2773 1ccf3a8d-04fe-1044-b7c0-cef0b8235c61

src/AddIns/Misc/Debugger/Debugger.Core/Project/Src/Threads/Exception.cs

@@ -39,7 +39,6 @@ namespace Debugger
 			Value runtimeValue = new Value(process,
 			                               string.Empty,
 			                               Expression.Empty,
-			                               new IExpirable[] {process.PauseSession},
 			                               delegate { return corValue; } );
 			message = runtimeValue.GetMember("_message").AsString;
 			

src/AddIns/Misc/Debugger/Debugger.Core/Project/Src/Threads/Function.cs

@@ -441,7 +441,6 @@ namespace Debugger
 						process,
 						"this",
 						new Ast.ThisReferenceExpression(),
-						new IExpirable[] {this},
 						delegate { return ThisCorValue; }
 					);
 				}
@@ -510,7 +509,6 @@ namespace Debugger
 				process,
 				name,
 				new Ast.ParameterIdentifierExpression(index, name),
-				new IExpirable[] {this},
 				delegate { return GetArgumentCorValue(index); }
 			);
 		}
@@ -601,7 +599,6 @@ namespace Debugger
 				process,
 				symVar.Name,
 				new Ast.LocalVariableIdentifierExpression(symVar),
-				new IExpirable[] {this},
 				delegate { return GetCorValueOfLocalVariable(symVar); }
 			);
 		}

src/AddIns/Misc/Debugger/Debugger.Core/Project/Src/Threads/Thread.cs

@@ -168,7 +168,6 @@ namespace Debugger
 					process,
 					string.Empty,
 					Expression.Empty,
-					new IExpirable[] {process.PauseSession},
 					delegate { return CorThread.Object;}
 				);
 			}

src/AddIns/Misc/Debugger/Debugger.Core/Project/Src/Variables/Evals/Eval.cs

@@ -235,7 +235,6 @@ namespace Debugger
 				result = new Value(process,
 				                   string.Empty,
 				                   Expression.Empty,
-				                   new IExpirable[] {},
 				                   delegate { return corEval.Result; });
 			}
 		}

src/AddIns/Misc/Debugger/Debugger.Core/Project/Src/Variables/Expressions/Expression.cs

@@ -20,15 +20,19 @@ namespace Debugger
 	/// </summary>
 	public class Expression: DebuggerObject
 	{
-		public static Expression Empty = null;
+		public static Expression Empty = new Expression(null);
 		
 		Ast.Expression expressionAst;
 		
 		public string Code {
 			get {
-				CSharpOutputVisitor csOutVisitor = new CSharpOutputVisitor();
-				expressionAst.AcceptVisitor(csOutVisitor, null);
-				return csOutVisitor.Text;
+				if (expressionAst != null) {
+					CSharpOutputVisitor csOutVisitor = new CSharpOutputVisitor();
+					expressionAst.AcceptVisitor(csOutVisitor, null);
+					return csOutVisitor.Text;
+				} else {
+					return string.Empty;
+				}
 			}
 		}
 		

src/AddIns/Misc/Debugger/Debugger.Core/Project/Src/Variables/Values/Value.Array.cs

@@ -80,7 +80,6 @@ namespace Debugger
 				Process,
 				GetNameFromIndices(indices),
 				GetExpressionFromIndices(indices),
-				new IExpirable[] {this},
 				delegate { return GetCorValueOfArrayElement(indices); }
 			);
 		}

src/AddIns/Misc/Debugger/Debugger.Core/Project/Src/Variables/Values/Value.Object.cs

@@ -56,7 +56,6 @@ namespace Debugger
 					objectInstance.Expression,
 					fieldInfo
 				),
-				new IExpirable[] {objectInstance},
 				delegate { return GetFieldCorValue(objectInstance, fieldInfo); }
 			);
 		}
@@ -123,7 +122,6 @@ namespace Debugger
 					objectInstance.Expression,
 					propertyInfo
 				),
-				dependencies.ToArray(),
 				delegate { return Value.InvokeMethod(objectInstance, propertyInfo.GetMethod, arguments).RawCorValue; }
 			);
 		}

src/AddIns/Misc/Debugger/Debugger.Core/Project/Src/Variables/Values/Value.cs

@@ -42,7 +42,7 @@ namespace Debugger
 		
 		CorValueGetter corValueGetter;
 		
-		/// <summary> Occurs when the Value can not be used anymore </summary>
+		/// <summary> Occurs when the Value can not be used </summary>
 		public event EventHandler Expired;
 		
 		bool isExpired = false;
@@ -177,10 +177,12 @@ namespace Debugger
 		internal Value(Process process,
 		               string name,
 		               Expression expression,
-		               IExpirable[] expireDependencies,
 		               CorValueGetter corValueGetter)
 		{
+			this.process = process;
 			this.name = name;
+			this.expression = expression;
+			this.corValueGetter = corValueGetter;
 			
 			// TODO: clean up
 			if (name.StartsWith("<") && name.Contains(">") && name != "<Base class>") {
@@ -190,36 +192,13 @@ namespace Debugger
 				}
 			}
 			
-			this.process = process;
-			this.expression = expression;
-			
-			AddExpireDependency(process);
-			foreach(IExpirable exp in expireDependencies) {
-				AddExpireDependency(exp);
-			}
-			
-			this.corValueGetter = corValueGetter;
-		}
-		
-		void AddExpireDependency(IExpirable dependency)
-		{
-			if (dependency.HasExpired) {
-				MakeExpired();
-			} else {
-				dependency.Expired += delegate { MakeExpired(); };
-			}
-		}
-		
-		void MakeExpired()
-		{
-			if (!isExpired) {
-				isExpired = true;
-				OnExpired(new ValueEventArgs(this));
-			}
+			process.DebuggingResumed += delegate {
+				this.isExpired = true;
+				OnExpired(EventArgs.Empty);
+			};
 		}
 		
-		/// <summary> Is called when the value expires and can not be 
-		/// used anymore </summary>
+		/// <summary> Is called when the value expires and can not be used </summary>
 		protected virtual void OnExpired(EventArgs e)
 		{
 			if (Expired != null) {