Do not load generators in VS process

src/VisualStudio/Core/Impl/SolutionExplorer/DiagnosticItem/CpsDiagnosticItemSource.cs

@@ -8,6 +8,8 @@
 using System.Linq;
 using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.Diagnostics;
+using Microsoft.CodeAnalysis.Editor.Shared.Utilities;
+using Microsoft.CodeAnalysis.Shared.TestHooks;
 using Microsoft.Internal.VisualStudio.PlatformUI;
 using Microsoft.VisualStudio.Shell;
 
@@ -18,27 +20,24 @@ internal sealed partial class CpsDiagnosticItemSource : BaseDiagnosticAndGenerat
     private readonly IVsHierarchyItem _item;
     private readonly string _projectDirectoryPath;
 
-    /// <summary>
-    /// The analyzer reference that has been found. Once it's been assigned a non-null value, it'll never be assigned null again.
-    /// </summary>
-    private AnalyzerReference? _analyzerReference;
-
     public event PropertyChangedEventHandler? PropertyChanged;
 
     public CpsDiagnosticItemSource(
+        IThreadingContext threadingContext,
         Workspace workspace,
         string projectPath,
         ProjectId projectId,
         IVsHierarchyItem item,
         IAnalyzersCommandHandler commandHandler,
-        IDiagnosticAnalyzerService analyzerService)
-        : base(workspace, projectId, commandHandler, analyzerService)
+        IDiagnosticAnalyzerService analyzerService,
+        IAsynchronousOperationListenerProvider listenerProvider)
+        : base(threadingContext, workspace, projectId, commandHandler, analyzerService, listenerProvider)
     {
         _item = item;
         _projectDirectoryPath = Path.GetDirectoryName(projectPath);
 
-        _analyzerReference = TryGetAnalyzerReference(Workspace.CurrentSolution);
-        if (_analyzerReference == null)
+        this.AnalyzerReference = TryGetAnalyzerReference(Workspace.CurrentSolution);
+        if (this.AnalyzerReference == null)
         {
             // The ProjectId that was given to us was found by enumerating the list of projects in the solution,
             // thus the project must have already been added to the workspace at some point. As long as the project
@@ -55,7 +54,7 @@ public CpsDiagnosticItemSource(
 
                 if (analyzerReference != null)
                 {
-                    _analyzerReference = analyzerReference;
+                    this.AnalyzerReference = analyzerReference;
                     UnsubscribeFromEvents();
                 }
             }
@@ -81,8 +80,6 @@ private void IVsHierarchyItem_PropertyChanged(object sender, PropertyChangedEven
 
     public override object SourceItem => _item;
 
-    public override AnalyzerReference? AnalyzerReference => _analyzerReference;
-
     private void OnWorkspaceChangedLookForAnalyzer(object sender, WorkspaceChangeEventArgs e)
     {
         // If the project has gone away in this change, it's not coming back, so we can stop looking at this point
@@ -99,7 +96,7 @@ private void OnWorkspaceChangedLookForAnalyzer(object sender, WorkspaceChangeEve
             var analyzerReference = TryGetAnalyzerReference(e.NewSolution);
             if (analyzerReference != null)
             {
-                _analyzerReference = analyzerReference;
+                this.AnalyzerReference = analyzerReference;
                 UnsubscribeFromEvents();
 
                 PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(HasItems)));

src/VisualStudio/Core/Impl/SolutionExplorer/DiagnosticItem/CpsDiagnosticItemSourceProvider.cs

@@ -63,7 +63,7 @@ internal sealed class CpsDiagnosticItemSourceProvider(
                         if (hierarchy.GetCanonicalName(itemId, out var projectCanonicalName) == VSConstants.S_OK)
                         {
                             return new CpsDiagnosticItemSource(
-                                _workspace, projectCanonicalName, projectId, item, _commandHandler, _diagnosticAnalyzerService);
+                                _threadingContext, _workspace, projectCanonicalName, projectId, item, _commandHandler, _diagnosticAnalyzerService, _listenerProvider);
                         }
                     }
                 }

src/VisualStudio/Core/Impl/SolutionExplorer/DiagnosticItem/DiagnosticItem.BrowseObject.cs

@@ -105,7 +105,7 @@ public string Tags
 
             [BrowseObjectDisplayName(nameof(SolutionExplorerShim.Effective_severity))]
             public string EffectiveSeverity
-                => MapReportDiagnosticToText(_diagnosticItem.EffectiveSeverity);
+                => MapReportDiagnosticToText(_diagnosticItem._effectiveSeverity);
 
             public override string GetClassName()
             {

src/VisualStudio/Core/Impl/SolutionExplorer/DiagnosticItem/DiagnosticItem.cs

@@ -3,7 +3,6 @@
 // See the LICENSE file in the project root for more information.
 
 using System;
-using System.ComponentModel;
 using System.Threading;
 using System.Threading.Tasks;
 using System.Xml.Linq;
@@ -30,29 +29,16 @@ internal sealed partial class DiagnosticItem(
 
     public ProjectId ProjectId { get; } = projectId;
     public DiagnosticDescriptor Descriptor { get; } = descriptor;
-    public ReportDiagnostic EffectiveSeverity { get; private set; } = effectiveSeverity;
-
-    public override event PropertyChangedEventHandler? PropertyChanged;
+    private readonly ReportDiagnostic _effectiveSeverity = effectiveSeverity;
 
     public override ImageMoniker IconMoniker
-        => MapEffectiveSeverityToIconMoniker(this.EffectiveSeverity);
+        => MapEffectiveSeverityToIconMoniker(_effectiveSeverity);
 
     public override IContextMenuController ContextMenuController => _commandHandler.DiagnosticContextMenuController;
 
     public override object GetBrowseObject()
         => new BrowseObject(this);
 
-    internal void UpdateEffectiveSeverity(ReportDiagnostic newEffectiveSeverity)
-    {
-        if (EffectiveSeverity != newEffectiveSeverity)
-        {
-            EffectiveSeverity = newEffectiveSeverity;
-
-            NotifyPropertyChanged(nameof(EffectiveSeverity));
-            NotifyPropertyChanged(nameof(IconMoniker));
-        }
-    }
-
     private static ImageMoniker MapEffectiveSeverityToIconMoniker(ReportDiagnostic effectiveSeverity)
         => effectiveSeverity switch
         {
@@ -64,11 +50,6 @@ private static ImageMoniker MapEffectiveSeverityToIconMoniker(ReportDiagnostic e
             _ => default,
         };
 
-    private void NotifyPropertyChanged(string propertyName)
-    {
-        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
-    }
-
     internal void SetRuleSetSeverity(ReportDiagnostic value, string pathToRuleSet)
     {
         var ruleSetDocument = XDocument.Load(pathToRuleSet);
@@ -88,7 +69,7 @@ internal Task<Solution> GetSolutionWithUpdatedAnalyzerConfigSeverityAsync(Report
     public override int GetHashCode()
         => Hash.Combine(this.Name,
             Hash.Combine(this.ProjectId,
-            Hash.Combine(this.Descriptor.GetHashCode(), (int)this.EffectiveSeverity)));
+            Hash.Combine(this.Descriptor.GetHashCode(), (int)_effectiveSeverity)));
 
     public override bool Equals(object obj)
         => Equals(obj as DiagnosticItem);
@@ -102,6 +83,6 @@ public bool Equals(DiagnosticItem? other)
             this.Name == other.Name &&
             this.ProjectId == other.ProjectId &&
             this.Descriptor.Equals(other.Descriptor) &&
-            this.EffectiveSeverity == other.EffectiveSeverity;
+            _effectiveSeverity == other._effectiveSeverity;
     }
 }

src/VisualStudio/Core/Impl/SolutionExplorer/DiagnosticItem/LegacyDiagnosticItemSource.cs

@@ -3,6 +3,8 @@
 // See the LICENSE file in the project root for more information.
 
 using Microsoft.CodeAnalysis.Diagnostics;
+using Microsoft.CodeAnalysis.Editor.Shared.Utilities;
+using Microsoft.CodeAnalysis.Shared.TestHooks;
 
 namespace Microsoft.VisualStudio.LanguageServices.Implementation.SolutionExplorer;
 
@@ -11,19 +13,22 @@ internal sealed partial class LegacyDiagnosticItemSource : BaseDiagnosticAndGene
     private readonly AnalyzerItem _item;
 
     public LegacyDiagnosticItemSource(
+        IThreadingContext threadingContext,
         AnalyzerItem item,
         IAnalyzersCommandHandler commandHandler,
-        IDiagnosticAnalyzerService diagnosticAnalyzerService)
+        IDiagnosticAnalyzerService diagnosticAnalyzerService,
+        IAsynchronousOperationListenerProvider listenerProvider)
         : base(
+            threadingContext,
             item.AnalyzersFolder.Workspace,
             item.AnalyzersFolder.ProjectId,
             commandHandler,
-            diagnosticAnalyzerService)
+            diagnosticAnalyzerService,
+            listenerProvider)
     {
         _item = item;
+        this.AnalyzerReference = item.AnalyzerReference;
     }
 
     public override object SourceItem => _item;
-
-    public override AnalyzerReference? AnalyzerReference => _item.AnalyzerReference;
 }

src/VisualStudio/Core/Impl/SolutionExplorer/DiagnosticItem/LegacyDiagnosticItemSourceProvider.cs

@@ -21,15 +21,17 @@ namespace Microsoft.VisualStudio.LanguageServices.Implementation.SolutionExplore
 [method: ImportingConstructor]
 [method: Obsolete(MefConstruction.ImportingConstructorMessage, error: true)]
 internal sealed class LegacyDiagnosticItemSourceProvider(
+    IThreadingContext threadingContext,
     [Import(typeof(AnalyzersCommandHandler))] IAnalyzersCommandHandler commandHandler,
-    IDiagnosticAnalyzerService diagnosticAnalyzerService) : AttachedCollectionSourceProvider<AnalyzerItem>
+    IDiagnosticAnalyzerService diagnosticAnalyzerService,
+    IAsynchronousOperationListenerProvider listenerProvider) : AttachedCollectionSourceProvider<AnalyzerItem>
 {
     protected override IAttachedCollectionSource? CreateCollectionSource(AnalyzerItem item, string relationshipName)
     {
         if (relationshipName == KnownRelationships.Contains)
         {
             return new LegacyDiagnosticItemSource(
-                item, commandHandler, diagnosticAnalyzerService);
+                threadingContext, item, commandHandler, diagnosticAnalyzerService, listenerProvider);
         }
 
         return null;

src/VisualStudio/Core/Test/SolutionExplorer/CpsDiagnosticItemSourceTests.vb

@@ -40,11 +40,13 @@ Namespace Microsoft.VisualStudio.LanguageServices.UnitTests.SolutionExplorer
 
                 Dim listenerProvider = workspace.GetService(Of IAsynchronousOperationListenerProvider)
                 Dim source As IAttachedCollectionSource = New CpsDiagnosticItemSource(
+                    workspace.GetService(Of IThreadingContext),
                     workspace,
                     project.FilePath,
                     project.Id,
                     New MockHierarchyItem() With {.CanonicalName = "\net472\analyzerdependency\" + analyzerPath},
-                    New FakeAnalyzersCommandHandler, workspace.GetService(Of IDiagnosticAnalyzerService))
+                    New FakeAnalyzersCommandHandler, workspace.GetService(Of IDiagnosticAnalyzerService),
+                    listenerProvider)
 
                 Assert.True(source.HasItems)
 

src/VisualStudio/Core/Test/SolutionExplorer/SourceGeneratorItemTests.vb

@@ -269,9 +269,11 @@ Namespace Microsoft.VisualStudio.LanguageServices.UnitTests.SolutionExplorer
             workspace.OnAnalyzerReferenceAdded(projectId, analyzerReference)
 
             Return New LegacyDiagnosticItemSource(
+                workspace.GetService(Of IThreadingContext),
                 New AnalyzerItem(New AnalyzersFolderItem(workspace, projectId, Nothing, Nothing), analyzerReference, Nothing),
                 New FakeAnalyzersCommandHandler,
-                workspace.GetService(Of IDiagnosticAnalyzerService))
+                workspace.GetService(Of IDiagnosticAnalyzerService),
+                workspace.GetService(Of IAsynchronousOperationListenerProvider))
         End Function
 
         Private Shared Function CreateSourceGeneratedFilesItemSource(workspace As EditorTestWorkspace, generatorItem As SourceGeneratorItem) As Shell.IAttachedCollectionSource

src/Workspaces/Core/Portable/SourceGeneration/IRemoteSourceGenerationService.cs

@@ -50,6 +50,13 @@ ValueTask<ImmutableArray<string>> GetContentsAsync(
     /// </summary>
     ValueTask<bool> HasGeneratorsAsync(
         Checksum solutionChecksum, ProjectId projectId, ImmutableArray<Checksum> analyzerReferenceChecksums, string language, CancellationToken cancellationToken);
+
+    /// <summary>
+    /// Returns the identities for all source generators found in the <see cref="AnalyzerReference"/> with <see
+    /// cref="AnalyzerFileReference.FullPath"/> equal to <paramref name="analyzerReferenceFullPath"/>.
+    /// </summary>
+    ValueTask<ImmutableArray<SourceGeneratorIdentity>> GetSourceGeneratorIdentitiesAsync(
+        Checksum solutionChecksum, ProjectId projectId, string analyzerReferenceFullPath, CancellationToken cancellationToken);
 }
 
 /// <summary>

src/Workspaces/Core/Portable/Workspace/Solution/SourceGeneratorIdentity.cs

@@ -3,8 +3,11 @@
 // See the LICENSE file in the project root for more information.
 
 using System;
+using System.Collections.Immutable;
 using System.Runtime.Serialization;
 using Microsoft.CodeAnalysis.Diagnostics;
+using Microsoft.CodeAnalysis.PooledObjects;
+using Roslyn.Utilities;
 
 namespace Microsoft.CodeAnalysis;
 
@@ -32,4 +35,14 @@ public static SourceGeneratorIdentity Create(ISourceGenerator generator, Analyze
         return new SourceGeneratorIdentity(
             assemblyName.Name!, analyzerReference.FullPath, assemblyName.Version!, generatorType.FullName!);
     }
+
+    public static ImmutableArray<SourceGeneratorIdentity> GetIdentities(
+        AnalyzerReference analyzerReference, string language)
+    {
+        using var _ = ArrayBuilder<SourceGeneratorIdentity>.GetInstance(out var result);
+        foreach (var generator in analyzerReference.GetGenerators(language))
+            result.Add(Create(generator, analyzerReference));
+
+        return result.ToImmutableAndClear();
+    }
 }

src/Workspaces/Remote/ServiceHub/Services/SourceGeneration/RemoteSourceGenerationService.cs

@@ -132,4 +132,21 @@ await assetProvider.GetAssetHelper<AnalyzerReference>().GetAssetsAsync(
 
         return false;
     }
+
+    public ValueTask<ImmutableArray<SourceGeneratorIdentity>> GetSourceGeneratorIdentitiesAsync(
+        Checksum solutionChecksum,
+        ProjectId projectId,
+        string analyzerReferenceFullPath,
+        CancellationToken cancellationToken)
+    {
+        return RunServiceAsync(solutionChecksum, solution =>
+        {
+            var project = solution.GetRequiredProject(projectId);
+            var analyzerReference = project.AnalyzerReferences
+                .OfType<AnalyzerFileReference>()
+                .First(r => r.FullPath == analyzerReferenceFullPath);
+
+            return ValueTaskFactory.FromResult(SourceGeneratorIdentity.GetIdentities(analyzerReference, project.Language));
+        }, cancellationToken);
+    }
 }