I am trying to write a visualizer that maps expressions in an expression tree to Roslyn syntax nodes, in order to generate code for the expression tree. Part of the syntax tree generation is a call to the AdhocWorkspace constructor.
When I run the visualizer using the VisualizerDevelopmentHost, everything works just fine:
using Microsoft.VisualStudio.DebuggerVisualizers;
using System;
using System.Linq.Expressions;
namespace _testVisualizer {
class Program {
[STAThread]
static void Main(string[] args) {
Expression<Func<bool>> expr = () => true;
var data = new TestVisualizerData(expr);
var visualizerHost = new VisualizerDevelopmentHost(data, typeof(TestVisualizer));
visualizerHost.ShowVisualizer();
Console.ReadKey(true);
}
}
}
But when I try to use the visualizer through the Visual Studio UI (by hovering over expr, clicking on the magnifying glass icon and choosing my visualizer), I get the following message:
Unable to perform function evaluation on the process being debugged.
Additional information
The function evaluation requires all threads to run.
I've identified the following as triggering the error:
workspace = new AdhocWorkspace();
which assigns to the workspace field on my Mapper class (source).
Why does calling the AdhocWorkspace constructor trigger this warning? How can I work around this?
This is an MCVE that demonstrates the issue:
using Microsoft.CodeAnalysis;
using Microsoft.VisualStudio.DebuggerVisualizers;
using System;
using System.Diagnostics;
using System.IO;
using System.Windows;
using System.Windows.Controls;
[assembly: DebuggerVisualizer(typeof(_testVisualizer.TestVisualizer), typeof(_testVisualizer.TestVisualizerDataObjectSource), Target = typeof(System.Linq.Expressions.Expression), Description = "Test Visualizer")]
namespace _testVisualizer {
public class TestVisualizer : DialogDebuggerVisualizer {
protected override void Show(IDialogVisualizerService windowService, IVisualizerObjectProvider objectProvider) {
var data = (TestVisualizerData)objectProvider.GetObject();
var txt = new TextBlock();
txt.SetBinding(TextBlock.TextProperty, "Status");
var window = new Window {
DataContext = data,
Content = txt
};
window.ShowDialog();
}
}
[Serializable]
public class TestVisualizerData {
public TestVisualizerData() { }
public TestVisualizerData(System.Linq.Expressions.Expression expr) {
var workspace = new AdhocWorkspace();
Status = "Success";
}
public string Status { get; set; }
}
public class TestVisualizerDataObjectSource : VisualizerObjectSource {
public override void GetData(object target, Stream outgoingData) {
var expr = (System.Linq.Expressions.Expression)target;
var data = new TestVisualizerData(expr);
base.GetData(data, outgoingData);
}
}
}
