addressing more feedbacks.

src/EditorFeatures/Core/Implementation/TodoComment/TodoCommentIncrementalAnalyzerProvider.cs

@@ -31,8 +31,7 @@ internal class TodoCommentIncrementalAnalyzerProvider : IIncrementalAnalyzerProv
             [ImportMany]IEnumerable<Lazy<IEventListener, EventListenerMetadata>> eventListeners)
         {
             _todoCommentTokens = todoCommentTokens;
-            _eventListenerTracker = new EventListenerTracker<ITodoListProvider>(
-                eventListeners.Where(l => l.Metadata.Service == WellKnownEventListeners.TodoListProvider));
+            _eventListenerTracker = new EventListenerTracker<ITodoListProvider>(eventListeners, WellKnownEventListeners.TodoListProvider);
         }
 
         public IIncrementalAnalyzer CreateIncrementalAnalyzer(Workspace workspace)

src/Features/Core/Portable/Diagnostics/DiagnosticService.cs

@@ -47,8 +47,7 @@ internal partial class DiagnosticService : IDiagnosticService
             _gate = new object();
             _map = new Dictionary<IDiagnosticUpdateSource, Dictionary<Workspace, Dictionary<object, Data>>>();
 
-            _eventListenerTracker = new EventListenerTracker<IDiagnosticService>(
-                eventListeners.Where(l => l.Metadata.Service == WellKnownEventListeners.DiagnosticService));
+            _eventListenerTracker = new EventListenerTracker<IDiagnosticService>(eventListeners, WellKnownEventListeners.DiagnosticService);
         }
 
         public event EventHandler<DiagnosticsUpdatedArgs> DiagnosticsUpdated

src/Features/Core/Portable/SolutionCrawler/SolutionCrawlerWorkspaceEventListener.cs → src/Features/Core/Portable/SolutionCrawler/HostSolutionCrawlerWorkspaceEventListener.cs

 // Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
 
-using System;
 using System.Composition;
 using Microsoft.CodeAnalysis.Host;
 
@@ -9,13 +8,13 @@ namespace Microsoft.CodeAnalysis.SolutionCrawler
     [ExportEventListener(WellKnownEventListeners.Workspace, WorkspaceKind.Host), Shared]
     internal class HostSolutionCrawlerWorkspaceEventListener : IEventListener<object>, IEventListenerStoppable
     {
-        public void Listen(Workspace workspace, object serviceOpt)
+        public void StartListening(Workspace workspace, object serviceOpt)
         {
             var registration = workspace.Services.GetService<ISolutionCrawlerRegistrationService>();
             registration.Register(workspace);
         }
 
-        public void Stop(Workspace workspace)
+        public void StopListening(Workspace workspace)
         {
             // we do this so that we can stop solution crawler faster and fire some telemetry. 
             // this is to reduce a case where we keep going even when VS is shutting down since we don't know about that
@@ -23,20 +22,4 @@ public void Stop(Workspace workspace)
             registration.Unregister(workspace, blockingShutdown: true);
         }
     }
-
-    [ExportEventListener(WellKnownEventListeners.Workspace, WorkspaceKind.MiscellaneousFiles), Shared]
-    internal class MiscSolutionCrawlerWorkspaceEventListener : IEventListener<object>, IEventListenerStoppable
-    {
-        public void Listen(Workspace workspace, object serviceOpt)
-        {
-            // misc workspace will enable syntax errors and semantic errors for script files for
-            // all participating projects in the workspace
-            DiagnosticProvider.Enable(workspace, DiagnosticProvider.Options.Syntax | DiagnosticProvider.Options.ScriptSemantic);
-        }
-
-        public void Stop(Workspace workspace)
-        {
-            DiagnosticProvider.Disable(workspace);
-        }
-    }
 }

src/Features/Core/Portable/SolutionCrawler/MiscSolutionCrawlerWorkspaceEventListener.cs

+// Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
+
+using System;
+using System.Composition;
+using Microsoft.CodeAnalysis.Host;
+
+namespace Microsoft.CodeAnalysis.SolutionCrawler
+{
+    [ExportEventListener(WellKnownEventListeners.Workspace, WorkspaceKind.MiscellaneousFiles), Shared]
+    internal class MiscSolutionCrawlerWorkspaceEventListener : IEventListener<object>, IEventListenerStoppable
+    {
+        public void StartListening(Workspace workspace, object serviceOpt)
+        {
+            // misc workspace will enable syntax errors and semantic errors for script files for
+            // all participating projects in the workspace
+            DiagnosticProvider.Enable(workspace, DiagnosticProvider.Options.Syntax | DiagnosticProvider.Options.ScriptSemantic);
+        }
+
+        public void StopListening(Workspace workspace)
+        {
+            DiagnosticProvider.Disable(workspace);
+        }
+    }
+}

src/Features/Core/Portable/SolutionCrawler/SolutionCrawlerRegistrationService.cs

@@ -50,16 +50,17 @@ public void Register(Workspace workspace)
 
         /// <summary>
         /// make sure solution cralwer is registered for the given workspace.
-        /// 
-        /// we need this until https://github.com/dotnet/roslyn/issues/35514 is fixed.
-        /// 
-        /// basically, solution crawler is currently not initialized until a file is opened (package is loaded)
-        /// this force solution crawler to be initialized.
-        /// 
-        /// initializeLazily should be removed once the issue above is fixed. 
         /// </summary>
-        /// <param name="workspace"></param>
-        internal void EnsureRegistration(Workspace workspace, bool initializeLazily)
+        /// <param name="workspace"><see cref="Workspace"/> this solution crawler runs for</param>
+        /// <param name="initializeLazily">
+        /// when true, solution crawler will be initialized when there is the first workspace event fired. 
+        /// otherwise, it will be initialized when workspace is registered right away. 
+        /// something like "Build" will use initializeLazily:false to make sure diagnostic analyzer engine (incremental analyzer)
+        /// is initialized. otherwise, if build is called before workspace is fully populated, we will think some errors from build
+        /// doesn't belong to us since diagnostic analyzer engine is not there yet and 
+        /// let project system to take care of these unknown errors.
+        /// </param>
+        public void EnsureRegistration(Workspace workspace, bool initializeLazily)
         {
             var correlationId = LogAggregator.GetNextId();
 

src/VisualStudio/Core/Def/Implementation/Remote/RemoteHostClientServiceFactory.WorkspaceEventListener.cs

@@ -13,7 +13,7 @@ internal partial class RemoteHostClientServiceFactory : IWorkspaceServiceFactory
         [ExportEventListener(WellKnownEventListeners.Workspace, WorkspaceKind.Host), Shared]
         private sealed class RemoteHostWorkspaceEventListener : IEventListener<object>
         {
-            public void Listen(Workspace workspace, object serviceOpt)
+            public void StartListening(Workspace workspace, object serviceOpt)
             {
                 var service = (RemoteHostClientService)workspace.Services.GetService<IRemoteHostClientService>();
                 service.Enable();

src/VisualStudio/Core/Def/Implementation/TableDataSource/MiscellaneousDiagnosticListTable.cs

@@ -22,7 +22,7 @@ public MiscellaneousDiagnosticListTableWorkspaceEventListener(ITableManagerProvi
             _tableManagerProvider = tableManagerProvider;
         }
 
-        public void Listen(Workspace workspace, IDiagnosticService diagnosticService)
+        public void StartListening(Workspace workspace, IDiagnosticService diagnosticService)
         {
             new MiscellaneousDiagnosticListTable(workspace, diagnosticService, _tableManagerProvider);
         }

src/VisualStudio/Core/Def/Implementation/TableDataSource/MiscellaneousTodoListTable.cs

@@ -21,7 +21,7 @@ public MiscellaneousTodoListTableWorkspaceEventListener(ITableManagerProvider ta
             _tableManagerProvider = tableManagerProvider;
         }
 
-        public void Listen(Workspace workspace, ITodoListProvider service)
+        public void StartListening(Workspace workspace, ITodoListProvider service)
         {
             new MiscellaneousTodoListTable(workspace, service, _tableManagerProvider);
         }

src/VisualStudio/Core/Def/Implementation/TableDataSource/VisualStudioDiagnosticListTable.cs

@@ -38,7 +38,7 @@ internal partial class VisualStudioDiagnosticListTableWorkspaceEventListener : I
             _tableManagerProvider = tableManagerProvider;
         }
 
-        public void Listen(Workspace workspace, IDiagnosticService diagnosticService)
+        public void StartListening(Workspace workspace, IDiagnosticService diagnosticService)
         {
             var errorList = _threadingContext.JoinableTaskFactory.Run(async () =>
             {

src/VisualStudio/Core/Def/Implementation/TableDataSource/VisualStudioTodoListTable.cs

@@ -21,7 +21,7 @@ public VisualStudioTodoListTableWorkspaceEventListener(ITableManagerProvider tab
             _tableManagerProvider = tableManagerProvider;
         }
 
-        public void Listen(Workspace workspace, ITodoListProvider service)
+        public void StartListening(Workspace workspace, ITodoListProvider service)
         {
             new VisualStudioTodoListTable(workspace, service, _tableManagerProvider);
         }

src/Workspaces/Core/Portable/Workspace/Host/EventListener/EventListenerMetadata.cs

@@ -28,7 +28,7 @@ internal class EventListenerMetadata : WorkspaceKindMetadata
                 throw new ArgumentException(nameof(workspaceKinds));
             }
 
-            this.Service = service ?? throw new ArgumentException("service");
+            this.Service = service ?? throw new ArgumentException(nameof(service));
         }
     }
 }

src/Workspaces/Core/Portable/Workspace/Host/EventListener/EventListenerTracker.cs

@@ -2,6 +2,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.Collections.Immutable;
 using System.Linq;
 
 namespace Microsoft.CodeAnalysis.Host
@@ -18,12 +19,18 @@ internal class EventListenerTracker<TService>
         /// Workspace kind this event listener is initialized for
         /// </summary>
         private readonly HashSet<string> _eventListenerInitialized;
-        private readonly IEnumerable<Lazy<IEventListener, EventListenerMetadata>> _eventListeners;
+        private readonly ImmutableArray<Lazy<IEventListener, EventListenerMetadata>> _eventListeners;
+
+        public EventListenerTracker(
+            IEnumerable<Lazy<IEventListener, EventListenerMetadata>> eventListeners, string kind) :
+            this(eventListeners.Where(el => el.Metadata.Service == kind))
+        {
+        }
 
         public EventListenerTracker(IEnumerable<Lazy<IEventListener, EventListenerMetadata>> eventListeners)
         {
             _eventListenerInitialized = new HashSet<string>();
-            _eventListeners = eventListeners;
+            _eventListeners = eventListeners.ToImmutableArray();
         }
 
         public void EnsureEventListener(Workspace workspace, TService serviceOpt)
@@ -38,7 +45,7 @@ public void EnsureEventListener(Workspace workspace, TService serviceOpt)
 
                 foreach (var listener in GetListeners(workspace, _eventListeners))
                 {
-                    listener.Listen(workspace, serviceOpt);
+                    listener.StartListening(workspace, serviceOpt);
                 }
             }
         }

src/Workspaces/Core/Portable/Workspace/Host/EventListener/ExportEventListenerAttribute.cs

@@ -28,7 +28,7 @@ public ExportEventListenerAttribute(string service, params string[] workspaceKin
                 throw new ArgumentException(nameof(workspaceKinds));
             }
 
-            this.Service = service ?? throw new ArgumentException("service");
+            this.Service = service ?? throw new ArgumentException(nameof(service));
             this.WorkspaceKinds = workspaceKinds;
         }
     }

src/Workspaces/Core/Portable/Workspace/Host/EventListener/IEventListener.cs

@@ -19,6 +19,6 @@ internal interface IEventListener
     /// </summary>
     internal interface IEventListenerStoppable
     {
-        void Stop(Workspace workspace);
+        void StopListening(Workspace workspace);
     }
 }

src/Workspaces/Core/Portable/Workspace/Host/EventListener/IEventListener`1.cs

@@ -9,6 +9,6 @@ namespace Microsoft.CodeAnalysis.Host
     /// </summary>
     internal interface IEventListener<TService> : IEventListener
     {
-        void Listen(Workspace workspace, TService serviceOpt);
+        void StartListening(Workspace workspace, TService serviceOpt);
     }
 }

src/Workspaces/Core/Portable/Workspace/Host/EventListener/IWorkspaceEventListenerProvider.cs

@@ -9,7 +9,7 @@
 namespace Microsoft.CodeAnalysis.Host
 {
     /// <summary>
-    /// Ensure <see cref="IEventListener{TService}.Listen(Workspace, TService)"/> is called for the workspace
+    /// Ensure <see cref="IEventListener{TService}.StartListening(Workspace, TService)"/> is called for the workspace
     /// </summary>
     internal interface IWorkspaceEventListenerService : IWorkspaceService
     {
@@ -68,7 +68,7 @@ public void EnsureListeners()
 
                     foreach (var listener in _eventListeners)
                     {
-                        listener.Listen(_workspace, serviceOpt: null);
+                        listener.StartListening(_workspace, serviceOpt: null);
                     }
                 }
             }
@@ -85,7 +85,7 @@ public void Stop()
 
                     foreach (var listener in _eventListeners.OfType<IEventListenerStoppable>())
                     {
-                        listener.Stop(_workspace);
+                        listener.StopListening(_workspace);
                     }
                 }
             }

src/Workspaces/Core/Portable/Workspace/Host/Mef/WorkspaceKindMetadata.cs

@@ -14,7 +14,7 @@ internal class WorkspaceKindMetadata
 
         public WorkspaceKindMetadata(IDictionary<string, object> data)
         {
-            this.WorkspaceKinds = (string[])data.GetValueOrDefault("WorkspaceKinds");
+            this.WorkspaceKinds = (string[])data.GetValueOrDefault(nameof(WorkspaceKinds));
         }
 
         public WorkspaceKindMetadata(params string[] workspaceKinds)