Merge pull request #356 from heejaechang/diagnosticRefactoring

refactor diagnostic service to prepare prototype work

src/Compilers/Core/AnalyzerDriver/DiagnosticAnalysisContextHelpers.cs

@@ -2,7 +2,6 @@
 
 using System;
 using System.Collections.Immutable;
-using System.Threading;
 
 namespace Microsoft.CodeAnalysis.Diagnostics
 {

src/EditorFeatures/Core/EditorFeatures.csproj

@@ -351,7 +351,6 @@
     <Compile Include="Implementation\Diagnostics\ClassificationTypeDefinitions.cs" />
     <Compile Include="Implementation\Diagnostics\DiagnosticsClassificationTaggerProvider.cs" />
     <Compile Include="Implementation\Diagnostics\DiagnosticsClassificationTaggerProvider.TagSource.cs" />
-    <Compile Include="Implementation\Diagnostics\InternalDiagnosticsOptions.cs" />
     <Compile Include="Implementation\Diagnostics\DiagnosticsSquiggleTaggerProvider.cs" />
     <Compile Include="Implementation\Diagnostics\DiagnosticsSquiggleTaggerProvider.TagSource.cs" />
     <Compile Include="Implementation\DocumentationComments\AbstractDocumentationCommentCommandHandler.cs" />

src/EditorFeatures/Test/Diagnostics/DiagnosticProviderTestUtilities.cs

@@ -6,6 +6,7 @@
 using System.Threading;
 using Microsoft.CodeAnalysis.CSharp.Diagnostics;
 using Microsoft.CodeAnalysis.Diagnostics;
+using Microsoft.CodeAnalysis.Diagnostics.EngineV1;
 using Microsoft.CodeAnalysis.LanguageServices;
 using Microsoft.CodeAnalysis.Shared.Extensions;
 using Microsoft.CodeAnalysis.Text;

src/EditorFeatures/Test/Diagnostics/DiagnosticStateTests.cs

@@ -8,6 +8,7 @@
 using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.CodeAnalysis.Diagnostics;
+using Microsoft.CodeAnalysis.Diagnostics.EngineV1;
 using Microsoft.CodeAnalysis.Editor.UnitTests.Workspaces;
 using Microsoft.CodeAnalysis.Host;
 using Microsoft.CodeAnalysis.Host.Mef;
@@ -48,8 +49,8 @@ public void SerializationTest_Document()
                         new TextSpan(50, 60), "mappedFile3", 90, 90, 100, 100, "originalFile3", 110, 110, 120, 120, title: "test3 title", description: "test3 description", helpLink: "http://test3link"),
                 };
 
-                var original = new DiagnosticAnalyzerService.AnalysisData(version1, version2, diagnostics.ToImmutableArray());
-                var state = new DiagnosticAnalyzerService.DiagnosticIncrementalAnalyzer.DiagnosticState("Test", VersionStamp.Default, LanguageNames.CSharp);
+                var original = new DiagnosticIncrementalAnalyzer.AnalysisData(version1, version2, diagnostics.ToImmutableArray());
+                var state = new DiagnosticIncrementalAnalyzer.DiagnosticState("Test", VersionStamp.Default, LanguageNames.CSharp);
                 state.PersistAsync(document, original, CancellationToken.None).Wait();
 
                 var recovered = state.TryGetExistingDataAsync(document, CancellationToken.None).Result;
@@ -87,8 +88,8 @@ public void SerializationTest_Project()
                         workspace, document.Project.Id, description: "test3 description", helpLink: "http://test3link"),
                 };
 
-                var original = new DiagnosticAnalyzerService.AnalysisData(version1, version2, diagnostics.ToImmutableArray());
-                var state = new DiagnosticAnalyzerService.DiagnosticIncrementalAnalyzer.DiagnosticState("Test", VersionStamp.Default, LanguageNames.CSharp);
+                var original = new DiagnosticIncrementalAnalyzer.AnalysisData(version1, version2, diagnostics.ToImmutableArray());
+                var state = new DiagnosticIncrementalAnalyzer.DiagnosticState("Test", VersionStamp.Default, LanguageNames.CSharp);
                 state.PersistAsync(document.Project, original, CancellationToken.None).Wait();
 
                 var recovered = state.TryGetExistingDataAsync(document.Project, CancellationToken.None).Result;

src/EditorFeatures/Test2/Diagnostics/DiagnosticServiceTests.vb

@@ -5,6 +5,7 @@ Imports System.Reflection
 Imports System.Threading
 Imports Microsoft.CodeAnalysis
 Imports Microsoft.CodeAnalysis.Diagnostics
+Imports Microsoft.CodeAnalysis.Diagnostics.EngineV1
 Imports Microsoft.CodeAnalysis.Editor.UnitTests.Workspaces
 Imports Microsoft.CodeAnalysis.Text
 Imports Roslyn.Utilities
@@ -648,7 +649,7 @@ class AnonymousFunctions
                 Dim descriptorsMap = diagnosticService.GetDiagnosticDescriptors(project)
                 Assert.Equal(1, descriptorsMap.Count)
 
-                Dim incrementalAnalyzer = DirectCast(diagnosticService.CreateIncrementalAnalyzer(workspace), DiagnosticAnalyzerService.DiagnosticIncrementalAnalyzer)
+                Dim incrementalAnalyzer = DirectCast(DirectCast(diagnosticService.CreateIncrementalAnalyzer(workspace), DiagnosticAnalyzerService.IncrementalAnalyzerDelegatee).Analyzer, DiagnosticIncrementalAnalyzer)
 
                 ' Verify that for an analyzer which has a registered compilation start action such that the start action registered an end action,
                 ' we go and force complete all document diagnostics for entire project and then invoke and report end action diagnostics.

src/Features/CSharp/Diagnostics/CSharpSyntaxNodeAnalyzerService.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.Collections.Generic;
-using System.Collections.Immutable;
 using System.Composition;
-using Microsoft.CodeAnalysis.Diagnostics;
+using Microsoft.CodeAnalysis.Diagnostics.EngineV1;
 using Microsoft.CodeAnalysis.Host.Mef;
 
 namespace Microsoft.CodeAnalysis.CSharp.Diagnostics

src/Features/Core/CodeFixes/CodeFixService.cs

@@ -75,7 +75,7 @@ public async Task<FirstDiagnosticResult> GetFirstDiagnosticWithFixAsync(Document
 
             using (var diagnostics = SharedPools.Default<List<DiagnosticData>>().GetPooledObject())
             {
-                var fullResult = await _diagnosticService.TryGetDiagnosticsForSpanAsync(document, range, diagnostics.Object, cancellationToken).ConfigureAwait(false);
+                var fullResult = await _diagnosticService.TryAppendDiagnosticsForSpanAsync(document, range, diagnostics.Object, cancellationToken).ConfigureAwait(false);
                 foreach (var diagnostic in diagnostics.Object)
                 {
                     cancellationToken.ThrowIfCancellationRequested();

src/Features/Core/Diagnostics/AnalyzerDriverResources.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.
+
+namespace Microsoft.CodeAnalysis.Diagnostics
+{
+    internal static class AnalyzerDriverResources
+    {
+        internal static string AnalyzerFailure => FeaturesResources.UserDiagnosticAnalyzerFailure;
+        internal static string AnalyzerThrows => FeaturesResources.UserDiagnosticAnalyzerThrows;
+        internal static string ArgumentElementCannotBeNull => FeaturesResources.ArgumentElementCannotBeNull;
+        internal static string ArgumentCannotBeEmpty => FeaturesResources.ArgumentCannotBeEmpty;
+    }
+}

src/Features/Core/Diagnostics/AnalyzerManager.cs

@@ -7,6 +7,7 @@
 using System.Linq;
 using System.Reflection;
 using System.Runtime.CompilerServices;
+using Microsoft.CodeAnalysis.Diagnostics.Log;
 using Roslyn.Utilities;
 
 namespace Microsoft.CodeAnalysis.Diagnostics

src/Features/Core/Diagnostics/BaseDiagnosticIncrementalAnalyzer.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.Collections.Generic;
+using System.Collections.Immutable;
+using System.Threading;
+using System.Threading.Tasks;
+using Microsoft.CodeAnalysis.Options;
+using Microsoft.CodeAnalysis.SolutionCrawler;
+using Microsoft.CodeAnalysis.Text;
+
+namespace Microsoft.CodeAnalysis.Diagnostics
+{
+    internal abstract class BaseDiagnosticIncrementalAnalyzer : IIncrementalAnalyzer
+    {
+        #region IIncrementalAnalyzer
+        public abstract Task AnalyzeDocumentAsync(Document document, SyntaxNode bodyOpt, CancellationToken cancellationToken);
+        public abstract Task AnalyzeProjectAsync(Project project, bool semanticsChanged, CancellationToken cancellationToken);
+        public abstract Task AnalyzeSyntaxAsync(Document document, CancellationToken cancellationToken);
+        public abstract Task DocumentOpenAsync(Document document, CancellationToken cancellationToken);
+        public abstract Task DocumentResetAsync(Document document, CancellationToken cancellationToken);
+        public abstract Task NewSolutionSnapshotAsync(Solution solution, CancellationToken cancellationToken);
+        public abstract void RemoveDocument(DocumentId documentId);
+        public abstract void RemoveProject(ProjectId projectId);
+        #endregion
+
+        #region delegating methods from diagnostic analyzer service to each implementation of the engine
+        public abstract Task<ImmutableArray<DiagnosticData>> GetSpecificCachedDiagnosticsAsync(Solution solution, object id, CancellationToken cancellationToken);
+        public abstract Task<ImmutableArray<DiagnosticData>> GetCachedDiagnosticsAsync(Solution solution, ProjectId projectId = null, DocumentId documentId = null, CancellationToken cancellationToken = default(CancellationToken));
+        public abstract Task<ImmutableArray<DiagnosticData>> GetSpecificDiagnosticsAsync(Solution solution, object id, CancellationToken cancellationToken);
+        public abstract Task<ImmutableArray<DiagnosticData>> GetDiagnosticsAsync(Solution solution, ProjectId projectId = null, DocumentId documentId = null, CancellationToken cancellationToken = default(CancellationToken));
+        public abstract Task<ImmutableArray<DiagnosticData>> GetDiagnosticsForIdsAsync(Solution solution, ProjectId projectId = null, DocumentId documentId = null, ImmutableHashSet<string> diagnosticIds = null, CancellationToken cancellationToken = default(CancellationToken));
+        public abstract Task<ImmutableArray<DiagnosticData>> GetProjectDiagnosticsForIdsAsync(Solution solution, ProjectId projectId = null, ImmutableHashSet<string> diagnosticIds = null, CancellationToken cancellationToken = default(CancellationToken));
+        public abstract Task<bool> TryAppendDiagnosticsForSpanAsync(Document document, TextSpan range, List<DiagnosticData> diagnostics, CancellationToken cancellationToken);
+        public abstract Task<IEnumerable<DiagnosticData>> GetDiagnosticsForSpanAsync(Document document, TextSpan range, CancellationToken cancellationToken);
+        #endregion
+
+        public virtual bool NeedsReanalysisOnOptionChanged(object sender, OptionChangedEventArgs e)
+        {
+            return false;
+        }
+
+        public virtual void LogAnalyzerCountSummary()
+        {
+        }
+    }
+}

src/Features/Core/Diagnostics/DiagnosticAnalyzerService.DiagnosticAnalyzersAndStates.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.Collections.Concurrent;
-using System.Collections.Generic;
-using System.Collections.Immutable;
-using System.IO;
-using System.Linq;
-using System.Threading;
-using System.Threading.Tasks;
-using Roslyn.Utilities;
-
-namespace Microsoft.CodeAnalysis.Diagnostics
-{
-    using ProviderId = Int32;
-
-    internal partial class DiagnosticAnalyzerService
-    {
-        internal partial class DiagnosticIncrementalAnalyzer
-        {
-            /// <summary>
-            /// Maintains all MEF-imported diagnostic analyzers (with diagnostic states), which are enabled for all projects in the workspace,
-            /// and a map of per-project diagnostic analyzers (with diagnostic states).
-            /// </summary>
-            private partial class DiagnosticAnalyzersAndStates
-            {
-                private const string UserDiagnosticsPrefixTableName = "<UserDiagnostics>";
-
-                private readonly DiagnosticIncrementalAnalyzer _owner;
-                private readonly WorkspaceAnalyzersAndStates _sharedAnalyzersAndStates;
-                private readonly ConcurrentDictionary<ProjectId, ProjectAnalyzersAndStates> _projectAnalyzersAndStatesMap;
-
-                public readonly Workspace Workspace;
-
-                public DiagnosticAnalyzersAndStates(DiagnosticIncrementalAnalyzer owner, Workspace workspace, AnalyzerManager analyzerManager)
-                {
-                    _owner = owner;
-                    _sharedAnalyzersAndStates = new WorkspaceAnalyzersAndStates(analyzerManager);
-                    _projectAnalyzersAndStatesMap = new ConcurrentDictionary<ProjectId, ProjectAnalyzersAndStates>();
-
-                    this.Workspace = workspace;
-                }
-
-                public IEnumerable<Tuple<DiagnosticState, ProviderId, StateType>> GetAllExistingDiagnosticStates(ProjectId projectId)
-                {
-                    var project = this.Workspace.CurrentSolution.GetProject(projectId);
-                    var language = project != null ? project.Language : null;
-                    return GetAllExistingDiagnosticStates(projectId, language);
-                }
-
-                public IEnumerable<Tuple<DiagnosticState, ProviderId, StateType>> GetAllExistingDiagnosticStates(ProjectId projectId, string language)
-                {
-                    var current = _sharedAnalyzersAndStates.GetAllExistingDiagnosticStates(language);
-
-                    ProjectAnalyzersAndStates projectAnalyzersAndStates;
-                    if (_projectAnalyzersAndStatesMap.TryGetValue(projectId, out projectAnalyzersAndStates) &&
-                        projectAnalyzersAndStates != null)
-                    {
-                        current = current.Concat(projectAnalyzersAndStates.GetAllExistingDiagnosticStates());
-                    }
-
-                    return current;
-                }
-
-                public IEnumerable<Tuple<DiagnosticState, ProviderId, StateType>> GetAllExistingDiagnosticStates(ProjectId projectId, StateType type)
-                {
-                    var project = this.Workspace.CurrentSolution.GetProject(projectId);
-                    var language = project != null ? project.Language : null;
-                    return GetAllExistingDiagnosticStates(projectId, type, language);
-                }
-
-                public IEnumerable<Tuple<DiagnosticState, ProviderId, StateType>> GetAllExistingDiagnosticStates(ProjectId projectId, StateType type, string language)
-                {
-                    var current = _sharedAnalyzersAndStates.GetAllExistingDiagnosticStates(type, language);
-
-                    ProjectAnalyzersAndStates projectAnalyzersAndStates;
-                    if (_projectAnalyzersAndStatesMap.TryGetValue(projectId, out projectAnalyzersAndStates) &&
-                        projectAnalyzersAndStates != null)
-                    {
-                        current = current.Concat(projectAnalyzersAndStates.GetAllExistingDiagnosticStates(type));
-                    }
-
-                    return current;
-                }
-
-                public IEnumerable<KeyValuePair<DiagnosticAnalyzer, ProviderId>> GetAllExistingProviderAndIds(Project project)
-                {
-                    var current = _sharedAnalyzersAndStates.GetAllProviderAndIds(project.Language);
-
-                    ProjectAnalyzersAndStates projectAnalyzersAndStates;
-                    if (_projectAnalyzersAndStatesMap.TryGetValue(project.Id, out projectAnalyzersAndStates) &&
-                        projectAnalyzersAndStates != null)
-                    {
-                        current = current.Concat(projectAnalyzersAndStates.GetAllProviderAndIds());
-                    }
-
-                    return current;
-                }
-
-                public async Task<IEnumerable<KeyValuePair<DiagnosticAnalyzer, ProviderId>>> GetAllProviderAndIdsAsync(Project project, CancellationToken cancellationToken)
-                {
-                    var current = _sharedAnalyzersAndStates.GetAllProviderAndIds(project.Language);
-
-                    var projectAnalyzersAndStates = await GetOrCreateProjectAnalyzersAndStatesAsync(project, cancellationToken).ConfigureAwait(false);
-                    if (projectAnalyzersAndStates != null)
-                    {
-                        current = current.Concat(projectAnalyzersAndStates.GetAllProviderAndIds());
-                    }
-
-                    return current;
-                }
-
-                public DiagnosticState GetOrCreateDiagnosticState(StateType stateType, ProviderId providerId, DiagnosticAnalyzer provider, ProjectId projectId, string language)
-                {
-                    Contract.ThrowIfFalse(providerId >= 0);
-
-                    var sharedAnalyzersCount = _sharedAnalyzersAndStates.GetAnalyzerCount(language);
-                    if (providerId < sharedAnalyzersCount)
-                    {
-                        return _sharedAnalyzersAndStates.GetOrCreateDiagnosticState(stateType, providerId, provider, language);
-                    }
-
-                    ProjectAnalyzersAndStates projectAnalyzersAndStates;
-                    if (!_projectAnalyzersAndStatesMap.TryGetValue(projectId, out projectAnalyzersAndStates) ||
-                        projectAnalyzersAndStates == null)
-                    {
-                        return null;
-                    }
-
-                    return projectAnalyzersAndStates.GetOrCreateDiagnosticState(stateType, providerId, provider);
-                }
-
-                internal static DiagnosticState GetOrCreateDiagnosticState(DiagnosticState[,] diagnosticStateMaps, StateType stateType, int providerIndex, ProviderId providerId, DiagnosticAnalyzer provider, string language)
-                {
-                    Contract.ThrowIfFalse(providerIndex >= 0);
-                    Contract.ThrowIfFalse(providerIndex < diagnosticStateMaps.GetLength(1));
-
-                    if (diagnosticStateMaps[(int)stateType, providerIndex] == null)
-                    {
-                        var nameAndVersion = GetUniqueDiagnosticStateNameAndVersion(stateType, providerId, provider);
-
-                        var name = nameAndVersion.Item1;
-                        var version = nameAndVersion.Item2;
-                        diagnosticStateMaps[(int)stateType, providerIndex] = new DiagnosticState(name, version, language);
-
-#if DEBUG
-                        // Ensure diagnostic state name is indeed unique.
-                        foreach (var type in s_documentScopeStateTypes)
-                        {
-                            for (var pId = 0; pId < diagnosticStateMaps.GetLength(1); pId++)
-                            {
-                                if (diagnosticStateMaps[(int)type, pId] != null)
-                                {
-                                    Contract.ThrowIfFalse(name != diagnosticStateMaps[(int)type, pId].Name ||
-                                        (stateType == type &&
-                                         (pId == providerIndex || language != diagnosticStateMaps[(int)type, pId].Language)));
-                                }
-                            }
-                        }
-#endif
-                    }
-
-                    return diagnosticStateMaps[(int)stateType, providerIndex];
-                }
-
-                /// <summary>
-                /// Get the unique state name for the given {type, provider} tuple.
-                /// Note that this name is used by the underlying persistence stream of the corresponding <see cref="DiagnosticState"/> to Read/Write diagnostic data into the stream.
-                /// If any two distinct {type, provider} tuples have the same diagnostic state name, we will end up sharing the persistence stream between them, leading to duplicate/missing/incorrect diagnostic data.
-                /// </summary>
-                private static ValueTuple<string, VersionStamp> GetUniqueDiagnosticStateNameAndVersion(StateType type, ProviderId providerId, DiagnosticAnalyzer provider)
-                {
-                    Contract.ThrowIfNull(provider);
-
-                    // Get the unique ID for given diagnostic analyzer.
-                    // note that we also put version stamp so that we can detect changed provider
-                    var providerType = provider.GetType();
-                    var location = providerType.Assembly.Location;
-
-                    return ValueTuple.Create(UserDiagnosticsPrefixTableName + "_" + type + "_" + providerType.AssemblyQualifiedName, GetProviderVersion(location));
-                }
-
-                private static VersionStamp GetProviderVersion(string path)
-                {
-                    if (path == null || !File.Exists(path))
-                    {
-                        return VersionStamp.Default;
-                    }
-
-                    return VersionStamp.Create(File.GetLastWriteTimeUtc(path));
-                }
-
-                public DiagnosticState GetDiagnosticState(StateType stateType, ProviderId providerId, ProjectId projectId, string language)
-                {
-                    Contract.ThrowIfFalse(providerId >= 0);
-
-                    var sharedAnalyzersCount = _sharedAnalyzersAndStates.GetAnalyzerCount(language);
-                    if (providerId < sharedAnalyzersCount)
-                    {
-                        return _sharedAnalyzersAndStates.GetDiagnosticState(stateType, providerId, language);
-                    }
-
-                    ProjectAnalyzersAndStates projectAnalyzersAndStates;
-                    if (!_projectAnalyzersAndStatesMap.TryGetValue(projectId, out projectAnalyzersAndStates) ||
-                        projectAnalyzersAndStates == null)
-                    {
-                        return null;
-                    }
-
-                    return projectAnalyzersAndStates.GetDiagnosticState(stateType, providerId);
-                }
-
-                public bool RemoveProjectAnalyzersAndStates(ProjectId projectId)
-                {
-                    ProjectAnalyzersAndStates projectAnalyzersAndStates;
-                    return _projectAnalyzersAndStatesMap.TryRemove(projectId, out projectAnalyzersAndStates);
-                }
-
-                private async Task<ProjectAnalyzersAndStates> GetOrCreateProjectAnalyzersAndStatesAsync(Project project, CancellationToken cancellationToken)
-                {
-                    // Update per-project analyzers if needed.
-                    IEnumerable<Tuple<DiagnosticState, ProviderId, StateType>> removedStates;
-                    ProjectAnalyzersAndStates projectAnalyzersAndStates = this.GetOrCreateProjectAnalyzersAndStates(project, out removedStates);
-                    if (removedStates.Any())
-                    {
-                        // Analyzers got updated, so clear the existing persistent states.
-                        await _owner.RemoveCacheDataAsync(project, removedStates, cancellationToken).ConfigureAwait(false);
-                    }
-
-                    return projectAnalyzersAndStates;
-                }
-
-                private ProjectAnalyzersAndStates GetOrCreateProjectAnalyzersAndStates(Project project,
-                    out IEnumerable<Tuple<DiagnosticState, ProviderId, StateType>> removedStates)
-                {
-                    removedStates = SpecializedCollections.EmptyEnumerable<Tuple<DiagnosticState, ProviderId, StateType>>();
-
-                    var newAnalyzersBuilder = ImmutableArray.CreateBuilder<KeyValuePair<string, IEnumerable<DiagnosticAnalyzer>>>();
-                    foreach (var analyzerReference in project.AnalyzerReferences)
-                    {
-                        // Filter out duplicate analyzer references.
-                        if (_sharedAnalyzersAndStates.HasAnalyzerReference(analyzerReference, project.Language))
-                        {
-                            continue;
-                        }
-
-                        // Get analyzers in the analyzer reference for the given project language.
-                        // Filter out duplicate analyzers.
-                        // NOTE: The HasAnalyzerReference check above to filter out duplicate analyzer references works only for duplicate AnalyzerFileReference with the same underlying assembly.
-                        // However, we can also have AnalyzerImageReference, which might contain the same DiagnosticAnalyzer instance across different AnalyzerImageReference instances
-                        // and we want to avoid duplicate analyzers for that case. Hence we apply the HasAnalyzer filter here.
-                        var analyzers = analyzerReference.GetAnalyzers(project.Language)
-                            .Where(a => !_sharedAnalyzersAndStates.HasAnalyzer(a, project.Language));
-
-                        if (analyzers.Any())
-                        {
-                            newAnalyzersBuilder.Add(KeyValuePair.Create(analyzerReference.Display, analyzers));
-                        }
-                    }
-
-                    var newAnalyzers = newAnalyzersBuilder.ToImmutable();
-                    ProjectAnalyzersAndStates newProjectAnalyzersAndStates = null;
-
-                    ProjectAnalyzersAndStates currentProjectAnalyzersAndStates;
-                    if (_projectAnalyzersAndStatesMap.TryGetValue(project.Id, out currentProjectAnalyzersAndStates))
-                    {
-                        var newAnalyzersCount = newAnalyzers.Sum(kv => kv.Value.Count());
-                        if (currentProjectAnalyzersAndStates != null && currentProjectAnalyzersAndStates.AnalyzerCount == newAnalyzersCount)
-                        {
-                            Contract.ThrowIfFalse(currentProjectAnalyzersAndStates.AnalyzerCount > 0);
-
-                            // Project still has the same number of analyzers, does the saved projectAnalyzersAndStates has the same set of analyzers?
-                            var hasSameAnalyzers = true;
-                            foreach (var analyzerPair in newAnalyzers)
-                            {
-                                foreach (var analyzer in analyzerPair.Value)
-                                {
-                                    if (!currentProjectAnalyzersAndStates.HasAnalyzer(analyzer))
-                                    {
-                                        hasSameAnalyzers = false;
-                                        break;
-                                    }
-                                }
-                            }
-
-                            if (hasSameAnalyzers)
-                            {
-                                return currentProjectAnalyzersAndStates;
-                            }
-                        }
-                    }
-                    else
-                    {
-                        currentProjectAnalyzersAndStates = null;
-                    }
-
-                    if (currentProjectAnalyzersAndStates != null)
-                    {
-                        removedStates = currentProjectAnalyzersAndStates.GetAllExistingDiagnosticStates();
-                    }
-
-                    var workspaceAnalyzersCount = _sharedAnalyzersAndStates.GetAnalyzerCount(project.Language);
-                    newProjectAnalyzersAndStates = ProjectAnalyzersAndStates.CreateIfAnyAnalyzers(newAnalyzers, workspaceAnalyzersCount, project.Language);
-                    return _projectAnalyzersAndStatesMap.AddOrUpdate(project.Id, newProjectAnalyzersAndStates, (k, c) => newProjectAnalyzersAndStates);
-                }
-            }
-        }
-    }
-}

src/Features/Core/Diagnostics/DiagnosticAnalyzerService.DiagnosticState.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.Collections.Generic;
-using System.Collections.Immutable;
-using System.Collections.ObjectModel;
-using System.IO;
-using System.Linq;
-using System.Threading;
-using System.Threading.Tasks;
-using Microsoft.CodeAnalysis.Host;
-using Microsoft.CodeAnalysis.Shared.Extensions;
-using Microsoft.CodeAnalysis.SolutionCrawler.State;
-using Microsoft.CodeAnalysis.Text;
-using Roslyn.Utilities;
-
-namespace Microsoft.CodeAnalysis.Diagnostics
-{
-    internal partial class DiagnosticAnalyzerService
-    {
-        internal partial class DiagnosticIncrementalAnalyzer
-        {
-            internal class DiagnosticState : AbstractAnalyzerState<object, object, AnalysisData>
-            {
-                private const int FormatVersion = 5;
-
-                private readonly string _stateName;
-                private readonly VersionStamp _version;
-                private readonly string _language;
-
-                public DiagnosticState(string stateName, VersionStamp version, string language)
-                {
-                    Contract.ThrowIfNull(stateName);
-
-                    _stateName = stateName;
-                    _version = version;
-                    _language = language;
-                }
-
-                internal string Name
-                {
-                    get { return _stateName; }
-                }
-
-                internal string Language
-                {
-                    get { return _language; }
-                }
-
-                protected override object GetCacheKey(object value)
-                {
-                    var document = value as Document;
-                    if (document != null)
-                    {
-                        return document.Id;
-                    }
-
-                    var project = (Project)value;
-                    return project.Id;
-                }
-
-                protected override Solution GetSolution(object value)
-                {
-                    var document = value as Document;
-                    if (document != null)
-                    {
-                        return document.Project.Solution;
-                    }
-
-                    var project = (Project)value;
-                    return project.Solution;
-                }
-
-                protected override bool ShouldCache(object value)
-                {
-                    var document = value as Document;
-                    if (document != null)
-                    {
-                        return document.IsOpen();
-                    }
-
-                    var project = (Project)value;
-                    return project.Solution.Workspace.GetOpenDocumentIds(project.Id).Any();
-                }
-
-                protected override Task<Stream> ReadStreamAsync(IPersistentStorage storage, object value, CancellationToken cancellationToken)
-                {
-                    var document = value as Document;
-                    if (document != null)
-                    {
-                        return storage.ReadStreamAsync(document, _stateName, cancellationToken);
-                    }
-
-                    var project = (Project)value;
-                    return storage.ReadStreamAsync(project, _stateName, cancellationToken);
-                }
-
-                protected override AnalysisData TryGetExistingData(Stream stream, object value, CancellationToken cancellationToken)
-                {
-                    var document = value as Document;
-                    if (document != null)
-                    {
-                        return TryGetExistingData(stream, document.Project, document, cancellationToken);
-                    }
-
-                    var project = (Project)value;
-                    return TryGetExistingData(stream, project, null, cancellationToken);
-                }
-
-                private AnalysisData TryGetExistingData(Stream stream, Project project, Document document, CancellationToken cancellationToken)
-                {
-                    var list = SharedPools.Default<List<DiagnosticData>>().AllocateAndClear();
-                    try
-                    {
-                        using (var reader = new ObjectReader(stream))
-                        {
-                            var format = reader.ReadInt32();
-                            if (format != FormatVersion)
-                            {
-                                return null;
-                            }
-
-                            // saved data is for same provider of different version of dll
-                            var providerVersion = VersionStamp.ReadFrom(reader);
-                            if (providerVersion != _version)
-                            {
-                                return null;
-                            }
-
-                            var textVersion = VersionStamp.ReadFrom(reader);
-                            var dataVersion = VersionStamp.ReadFrom(reader);
-                            if (textVersion == VersionStamp.Default || dataVersion == VersionStamp.Default)
-                            {
-                                return null;
-                            }
-
-                            AppendItems(reader, project, document, list, cancellationToken);
-
-                            return new AnalysisData(textVersion, dataVersion, list.ToImmutableArray<DiagnosticData>());
-                        }
-                    }
-                    catch (Exception)
-                    {
-                        return null;
-                    }
-                    finally
-                    {
-                        SharedPools.Default<List<DiagnosticData>>().ClearAndFree(list);
-                    }
-                }
-
-                private void AppendItems(ObjectReader reader, Project project, Document document, List<DiagnosticData> list, CancellationToken cancellationToken)
-                {
-                    var count = reader.ReadInt32();
-
-                    for (var i = 0; i < count; i++)
-                    {
-                        cancellationToken.ThrowIfCancellationRequested();
-
-                        var id = reader.ReadString();
-                        var category = reader.ReadString();
-
-                        var message = reader.ReadString();
-                        var messageFormat = reader.ReadString();
-                        var title = reader.ReadString();
-                        var description = reader.ReadString();
-                        var helpLink = reader.ReadString();
-                        var severity = (DiagnosticSeverity)reader.ReadInt32();
-                        var defaultSeverity = (DiagnosticSeverity)reader.ReadInt32();
-                        var isEnabledByDefault = reader.ReadBoolean();
-                        var warningLevel = reader.ReadInt32();
-
-                        var start = reader.ReadInt32();
-                        var length = reader.ReadInt32();
-                        var textSpan = new TextSpan(start, length);
-
-                        var originalFile = reader.ReadString();
-                        var originalStartLine = reader.ReadInt32();
-                        var originalStartColumn = reader.ReadInt32();
-                        var originalEndLine = reader.ReadInt32();
-                        var originalEndColumn = reader.ReadInt32();
-
-                        var mappedFile = reader.ReadString();
-                        var mappedStartLine = reader.ReadInt32();
-                        var mappedStartColumn = reader.ReadInt32();
-                        var mappedEndLine = reader.ReadInt32();
-                        var mappedEndColumn = reader.ReadInt32();
-
-                        var customTagsCount = reader.ReadInt32();
-                        var customTags = GetCustomTags(reader, customTagsCount);
-
-                        list.Add(new DiagnosticData(
-                            id, category, message, messageFormat, severity, defaultSeverity, isEnabledByDefault, warningLevel, customTags,
-                            project.Solution.Workspace, project.Id, document != null ? document.Id : null, document != null ? textSpan : (TextSpan?)null,
-                            mappedFile, mappedStartLine, mappedStartColumn, mappedEndLine, mappedEndColumn,
-                            originalFile, originalStartLine, originalStartColumn, originalEndLine, originalEndColumn,
-                            title: title,
-                            description: description,
-                            helpLink: helpLink));
-                    }
-                }
-
-                private static IReadOnlyList<string> GetCustomTags(ObjectReader reader, int count)
-                {
-                    if (count > 0)
-                    {
-                        var tags = new List<string>(count);
-                        for (var i = 0; i < count; i++)
-                        {
-                            tags.Add(reader.ReadString());
-                        }
-
-                        return new ReadOnlyCollection<string>(tags);
-                    }
-
-                    return SpecializedCollections.EmptyReadOnlyList<string>();
-                }
-
-                protected override Task<bool> WriteStreamAsync(IPersistentStorage storage, object value, Stream stream, CancellationToken cancellationToken)
-                {
-                    var document = value as Document;
-                    if (document != null)
-                    {
-                        return storage.WriteStreamAsync(document, _stateName, stream, cancellationToken);
-                    }
-
-                    var project = (Project)value;
-                    return storage.WriteStreamAsync(project, _stateName, stream, cancellationToken);
-                }
-
-                protected override void WriteTo(Stream stream, AnalysisData data, CancellationToken cancellationToken)
-                {
-                    using (var writer = new ObjectWriter(stream, cancellationToken: cancellationToken))
-                    {
-                        writer.WriteInt32(FormatVersion);
-                        _version.WriteTo(writer);
-                        data.TextVersion.WriteTo(writer);
-                        data.DataVersion.WriteTo(writer);
-
-                        writer.WriteInt32(data.Items.Length);
-
-                        foreach (var item in data.Items)
-                        {
-                            cancellationToken.ThrowIfCancellationRequested();
-
-                            writer.WriteString(item.Id);
-                            writer.WriteString(item.Category);
-
-                            writer.WriteString(item.Message);
-                            writer.WriteString(item.MessageFormat);
-                            writer.WriteString(item.Title);
-                            writer.WriteString(item.Description);
-                            writer.WriteString(item.HelpLink);
-                            writer.WriteInt32((int)item.Severity);
-                            writer.WriteInt32((int)item.DefaultSeverity);
-                            writer.WriteBoolean(item.IsEnabledByDefault);
-                            writer.WriteInt32(item.WarningLevel);
-
-                            if (item.HasTextSpan)
-                            {
-                                // document state
-                                writer.WriteInt32(item.TextSpan.Start);
-                                writer.WriteInt32(item.TextSpan.Length);
-                            }
-                            else
-                            {
-                                // project state
-                                writer.WriteInt32(0);
-                                writer.WriteInt32(0);
-                            }
-
-                            writer.WriteString(item.OriginalFilePath);
-                            writer.WriteInt32(item.OriginalStartLine);
-                            writer.WriteInt32(item.OriginalStartColumn);
-                            writer.WriteInt32(item.OriginalEndLine);
-                            writer.WriteInt32(item.OriginalEndColumn);
-
-                            writer.WriteString(item.MappedFilePath);
-                            writer.WriteInt32(item.MappedStartLine);
-                            writer.WriteInt32(item.MappedStartColumn);
-                            writer.WriteInt32(item.MappedEndLine);
-                            writer.WriteInt32(item.MappedEndColumn);
-
-                            writer.WriteInt32(item.CustomTags.Count);
-                            foreach (var tag in item.CustomTags)
-                            {
-                                writer.WriteString(tag);
-                            }
-                        }
-                    }
-                }
-            }
-        }
-    }
-}

src/Features/Core/Diagnostics/DiagnosticAnalyzerService.IncrementalAnalyzer.AnalyzerExecutor.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.Collections.Immutable;
-using System.Diagnostics;
-using System.Threading.Tasks;
-using Microsoft.CodeAnalysis.ErrorReporting;
-using Roslyn.Utilities;
-
-namespace Microsoft.CodeAnalysis.Diagnostics
-{
-    using ProviderId = Int32;
-
-    internal partial class DiagnosticAnalyzerService
-    {
-        internal partial class DiagnosticIncrementalAnalyzer
-        {
-            /// <summary>
-            /// AnalyzerExecutor returns analyzed data without side effect. 
-            /// it might uses cache to skip unnecessary duplicate analysis, but it will never update any internal state such as state
-            /// 
-            /// this is not finished form. as refactoring going on, this class will become more stateless in respect to caller, and less dependency on owner.
-            /// </summary>
-            internal class AnalyzerExecutor
-            {
-                private readonly DiagnosticIncrementalAnalyzer _owner;
-
-                public AnalyzerExecutor(DiagnosticIncrementalAnalyzer owner)
-                {
-                    _owner = owner;
-                }
-
-                public async Task<AnalysisData> GetSyntaxAnalysisDataAsync(
-                    DiagnosticAnalyzer provider, ProviderId providerId, VersionArgument versions, DiagnosticAnalyzerDriver analyzerDriver)
-                {
-                    try
-                    {
-                        var document = analyzerDriver.Document;
-                        var cancellationToken = analyzerDriver.CancellationToken;
-
-                        var state = AnalyzersAndState.GetOrCreateDiagnosticState(StateType.Syntax, providerId, provider, document.Project.Id, document.Project.Language);
-                        var existingData = await state.TryGetExistingDataAsync(document, cancellationToken).ConfigureAwait(false);
-
-                        if (CheckSyntaxVersions(document, existingData, versions))
-                        {
-                            return existingData;
-                        }
-
-                        var diagnosticData = await GetSyntaxDiagnosticsAsync(providerId, provider, analyzerDriver).ConfigureAwait(false);
-                        return new AnalysisData(versions.TextVersion, versions.DataVersion, GetExistingItems(existingData), diagnosticData.AsImmutableOrEmpty());
-                    }
-                    catch (Exception e) when(FatalError.ReportUnlessCanceled(e))
-                    {
-                        throw ExceptionUtilities.Unreachable;
-                    }
-                    }
-
-                public async Task<AnalysisData> GetDocumentAnalysisDataAsync(
-                    DiagnosticAnalyzer provider, ProviderId providerId, VersionArgument versions, DiagnosticAnalyzerDriver analyzerDrvier)
-                {
-                    try
-                    {
-                        var document = analyzerDrvier.Document;
-                        var cancellationToken = analyzerDrvier.CancellationToken;
-
-                        var state = AnalyzersAndState.GetOrCreateDiagnosticState(StateType.Document, providerId, provider, document.Project.Id, document.Project.Language);
-                        var existingData = await state.TryGetExistingDataAsync(document, cancellationToken).ConfigureAwait(false);
-
-                        if (CheckSemanticVersions(document, existingData, versions))
-                        {
-                            return existingData;
-                        }
-
-                        var diagnosticData = await GetSemanticDiagnosticsAsync(providerId, provider, analyzerDrvier).ConfigureAwait(false);
-                        return new AnalysisData(versions.TextVersion, versions.DataVersion, GetExistingItems(existingData), diagnosticData.AsImmutableOrEmpty());
-                    }
-                    catch (Exception e) when(FatalError.ReportUnlessCanceled(e))
-                    {
-                        throw ExceptionUtilities.Unreachable;
-                    }
-                    }
-
-                public async Task<AnalysisData> GetDocumentBodyAnalysisDataAsync(
-                    DiagnosticAnalyzer provider, ProviderId providerId, VersionArgument versions, DiagnosticAnalyzerDriver analyzerDriver,
-                    SyntaxNode root, SyntaxNode member, int memberId, bool supportsSemanticInSpan, MemberRangeMap.MemberRanges ranges)
-                {
-                    try
-                    {
-                        var document = analyzerDriver.Document;
-                        var cancellationToken = analyzerDriver.CancellationToken;
-
-                        var state = AnalyzersAndState.GetOrCreateDiagnosticState(StateType.Document, providerId, provider, document.Project.Id, document.Project.Language);
-                        var existingData = await state.TryGetExistingDataAsync(document, cancellationToken).ConfigureAwait(false);
-
-                        ImmutableArray<DiagnosticData> diagnosticData;
-                        if (supportsSemanticInSpan && CanUseDocumentState(existingData, ranges.TextVersion, versions.DataVersion))
-                        {
-                            var memberDxData = await GetSemanticDiagnosticsAsync(providerId, provider, analyzerDriver).ConfigureAwait(false);
-
-                            diagnosticData = _owner.UpdateDocumentDiagnostics(existingData, ranges.Ranges, memberDxData.AsImmutableOrEmpty(), root.SyntaxTree, member, memberId);
-                            ValidateMemberDiagnostics(providerId, provider, document, root, diagnosticData);
-                        }
-                        else
-                        {
-                            // if we can't re-use existing document state, only option we have is updating whole document state here.
-                            var dx = await GetSemanticDiagnosticsAsync(providerId, provider, analyzerDriver).ConfigureAwait(false);
-                            diagnosticData = dx.AsImmutableOrEmpty();
-                        }
-
-                        return new AnalysisData(versions.TextVersion, versions.DataVersion, GetExistingItems(existingData), diagnosticData);
-                    }
-                    catch (Exception e) when(FatalError.ReportUnlessCanceled(e))
-                    {
-                        throw ExceptionUtilities.Unreachable;
-                    }
-                    }
-
-                public async Task<AnalysisData> GetProjectAnalysisDataAsync(
-                    DiagnosticAnalyzer provider, ProviderId providerId, VersionArgument versions, DiagnosticAnalyzerDriver analyzerDriver)
-                {
-                    try
-                    {
-                        var project = analyzerDriver.Project;
-                        var cancellationToken = analyzerDriver.CancellationToken;
-
-                        var state = AnalyzersAndState.GetOrCreateDiagnosticState(StateType.Project, providerId, provider, project.Id, project.Language);
-                        var existingData = await state.TryGetExistingDataAsync(project, cancellationToken).ConfigureAwait(false);
-
-                        if (CheckSemanticVersions(project, existingData, versions))
-                        {
-                            return existingData;
-                        }
-
-                        // TODO: remove ForceAnalyzeAllDocuments at some point
-                        var diagnosticData = await GetProjectDiagnosticsAsync(providerId, provider, analyzerDriver, _owner.ForceAnalyzeAllDocuments).ConfigureAwait(false);
-                        return new AnalysisData(VersionStamp.Default, versions.DataVersion, GetExistingItems(existingData), diagnosticData.AsImmutableOrEmpty());
-                    }
-                    catch (Exception e) when(FatalError.ReportUnlessCanceled(e))
-                    {
-                        throw ExceptionUtilities.Unreachable;
-                    }
-                    }
-
-                private DiagnosticAnalyzersAndStates AnalyzersAndState
-                {
-                    get { return _owner._analyzersAndState; }
-                }
-
-                private bool CanUseDocumentState(AnalysisData existingData, VersionStamp textVersion, VersionStamp dataVersion)
-                {
-                    if (existingData == null)
-                    {
-                        return false;
-                    }
-
-                    // make sure data stored in the cache is one from its previous text update
-                    return existingData.DataVersion.Equals(dataVersion) && existingData.TextVersion.Equals(textVersion);
-                }
-
-                private static ImmutableArray<DiagnosticData> GetExistingItems(AnalysisData existingData)
-                {
-                    if (existingData == null)
-                    {
-                        return ImmutableArray<DiagnosticData>.Empty;
-                    }
-
-                    return existingData.Items;
-                }
-
-                [Conditional("DEBUG")]
-                private void ValidateMemberDiagnostics(ProviderId providerId, DiagnosticAnalyzer provider, Document document, SyntaxNode root, ImmutableArray<DiagnosticData> diagnostics)
-                {
-#if RANGE
-                var documentBasedDriver = new DiagnosticAnalyzerDriver(document, root.FullSpan, root, CancellationToken.None);
-                var expected = GetSemanticDiagnosticsAsync(providerId, provider, documentBasedDriver).WaitAndGetResult(documentBasedDriver.CancellationToken) ?? SpecializedCollections.EmptyEnumerable<DiagnosticData>();
-                Contract.Requires(diagnostics.SetEquals(expected));
-#endif
-                }
-            }
-        }
-    }
-}

src/Features/Core/Diagnostics/DiagnosticAnalyzerService.WorkspaceAnalyzersAndStates.PerLanguageAnalyzersAndStates.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.Collections.Generic;
-using System.Collections.Immutable;
-using System.Linq;
-using Roslyn.Utilities;
-
-namespace Microsoft.CodeAnalysis.Diagnostics
-{
-    using ProviderId = Int32;
-
-    internal partial class DiagnosticAnalyzerService
-    {
-        internal partial class DiagnosticIncrementalAnalyzer
-        {
-            private partial class DiagnosticAnalyzersAndStates
-            {
-                private partial class WorkspaceAnalyzersAndStates
-                {
-                    /// <summary>
-                    /// Maintains all workspace diagnostic analyzers (with diagnostic states) for a specific language.
-                    /// </summary>
-                    private class PerLanguageAnalyzersAndStates
-                    {
-                        private readonly string _language;
-                        private readonly ImmutableDictionary<string, ImmutableDictionary<DiagnosticAnalyzer, ProviderId>> _diagnosticAnalyzerIdMap;
-                        private readonly int _analyzerCount;
-                        private readonly DiagnosticState[,] _diagnosticStateMaps;
-
-                        public PerLanguageAnalyzersAndStates(AnalyzerManager analyzerManager, string language)
-                        {
-                            _language = language;
-
-                            // TODO: dynamically re-order providers so that cheap one runs first and slower runs later.
-                            _diagnosticAnalyzerIdMap = CreateAnalyzerIdMap(analyzerManager, language);
-                            _analyzerCount = _diagnosticAnalyzerIdMap.Values.Flatten().Count();
-                            _diagnosticStateMaps = new DiagnosticState[s_stateTypeCount, _analyzerCount];
-                        }
-
-                        private static ImmutableDictionary<string, ImmutableDictionary<DiagnosticAnalyzer, ProviderId>> CreateAnalyzerIdMap(
-                            AnalyzerManager analyzerManager, string language)
-                        {
-                            var index = 0;
-                            var map = ImmutableDictionary.CreateBuilder<string, ImmutableDictionary<DiagnosticAnalyzer, ProviderId>>();
-
-                            foreach (var kv in analyzerManager.GetHostDiagnosticAnalyzersPerReference(language))
-                            {
-                                var perAnalyzerMap = ImmutableDictionary.CreateBuilder<DiagnosticAnalyzer, ProviderId>();
-
-                                var referenceIdentity = kv.Key;
-                                var perLanguageAnalyzers = kv.Value;
-
-                                if (perLanguageAnalyzers.Length > 0)
-                                {
-                                    foreach (var analyzer in perLanguageAnalyzers)
-                                    {
-                                        var analyzerId = index++;
-                                        perAnalyzerMap.Add(analyzer, analyzerId);
-                                    }
-
-                                    map.Add(referenceIdentity, perAnalyzerMap.ToImmutable());
-                                }
-                            }
-
-                            return map.ToImmutable();
-                        }
-
-                        public int AnalyzerCount
-                        {
-                            get { return _analyzerCount; }
-                        }
-
-                        public bool HasAnalyzerReference(AnalyzerReference analyzerReference)
-                        {
-                            Contract.ThrowIfNull(analyzerReference);
-
-                            if (analyzerReference is AnalyzerFileReference)
-                            {
-                                // Filter out duplicate analyzer references with same assembly name/full path.
-                                return analyzerReference.Display != null && _diagnosticAnalyzerIdMap.ContainsKey(analyzerReference.Display);
-                            }
-                            else
-                            {
-                                // For non-file references, we will check individual DiagnosticAnalyzer instances for duplicates.
-                                return false;
-                            }
-                        }
-
-                        public bool HasAnalyzer(DiagnosticAnalyzer analyzer)
-                        {
-                            Contract.ThrowIfNull(analyzer);
-                            return _diagnosticAnalyzerIdMap.Values.Any(dict => dict.ContainsKey(analyzer));
-                        }
-
-                        public IEnumerable<Tuple<DiagnosticState, ProviderId, StateType>> GetAllExistingDiagnosticStates(StateType type)
-                        {
-                            foreach (var analyzerAndId in _diagnosticAnalyzerIdMap.Values.Flatten())
-                            {
-                                yield return Tuple.Create(_diagnosticStateMaps[(int)type, analyzerAndId.Value], analyzerAndId.Value, type);
-                            }
-                        }
-
-                        public IEnumerable<KeyValuePair<DiagnosticAnalyzer, ProviderId>> GetAllProviderAndIds()
-                        {
-                            return _diagnosticAnalyzerIdMap.Values.Flatten();
-                        }
-
-                        public DiagnosticState GetOrCreateDiagnosticState(StateType stateType, ProviderId providerId, DiagnosticAnalyzer provider)
-                        {
-                            Contract.ThrowIfFalse(providerId >= 0);
-                            Contract.ThrowIfFalse(providerId < this.AnalyzerCount);
-
-                            return DiagnosticAnalyzersAndStates.GetOrCreateDiagnosticState(_diagnosticStateMaps, stateType, providerId, providerId, provider, _language);
-                        }
-
-                        public DiagnosticState GetDiagnosticState(StateType stateType, ProviderId providerId)
-                        {
-                            Contract.ThrowIfFalse(providerId >= 0);
-                            Contract.ThrowIfFalse(providerId < this.AnalyzerCount);
-
-                            return _diagnosticStateMaps[(int)stateType, providerId];
-                        }
-                    }
-                }
-            }
-        }
-    }
-}

src/Features/Core/Diagnostics/DiagnosticAnalyzerService.WorkspaceAnalyzersAndStates.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.Collections.Generic;
-using System.Collections.Immutable;
-using System.Linq;
-using Roslyn.Utilities;
-
-namespace Microsoft.CodeAnalysis.Diagnostics
-{
-    using ProviderId = Int32;
-
-    internal partial class DiagnosticAnalyzerService
-    {
-        internal partial class DiagnosticIncrementalAnalyzer
-        {
-            private partial class DiagnosticAnalyzersAndStates
-            {
-                /// <summary>
-                /// Maintains all workspace diagnostic analyzers (with diagnostic states), which are enabled for all projects in the workspace.
-                /// </summary>
-                private partial class WorkspaceAnalyzersAndStates
-                {
-                    private readonly AnalyzerManager _analyzerManager;
-                    private ImmutableDictionary<string, PerLanguageAnalyzersAndStates> _perLanguageAnalyzersAndStatesMap;
-
-                    public WorkspaceAnalyzersAndStates(AnalyzerManager analyzerManager)
-                    {
-                        _analyzerManager = analyzerManager;
-                        _perLanguageAnalyzersAndStatesMap = ImmutableDictionary<string, PerLanguageAnalyzersAndStates>.Empty;
-                    }
-
-                    private static PerLanguageAnalyzersAndStates CreatePerLanguageAnalyzersAndStates(string language, WorkspaceAnalyzersAndStates @this)
-                    {
-                        return new PerLanguageAnalyzersAndStates(@this._analyzerManager, language);
-                    }
-
-                    private PerLanguageAnalyzersAndStates GetOrCreatePerLanguageAnalyzersAndStates(string language)
-                    {
-                        return ImmutableInterlocked.GetOrAdd(ref _perLanguageAnalyzersAndStatesMap, language, CreatePerLanguageAnalyzersAndStates, this);
-                    }
-
-                    public int GetAnalyzerCount(string language)
-                    {
-                        var analyzersAndStates = this.GetOrCreatePerLanguageAnalyzersAndStates(language);
-                        return analyzersAndStates.AnalyzerCount;
-                    }
-
-                    public bool HasAnalyzerReference(AnalyzerReference analyzerReference, string language)
-                    {
-                        var analyzersAndStates = this.GetOrCreatePerLanguageAnalyzersAndStates(language);
-                        return analyzersAndStates.HasAnalyzerReference(analyzerReference);
-                    }
-
-                    public bool HasAnalyzer(DiagnosticAnalyzer analyzer, string language)
-                    {
-                        if (analyzer == null)
-                        {
-                            return false;
-                        }
-
-                        var analyzersAndStates = this.GetOrCreatePerLanguageAnalyzersAndStates(language);
-                        return analyzersAndStates.HasAnalyzer(analyzer);
-                    }
-
-                    public IEnumerable<Tuple<DiagnosticState, ProviderId, StateType>> GetAllExistingDiagnosticStates(string languageOpt)
-                    {
-                        var current = SpecializedCollections.EmptyEnumerable<Tuple<DiagnosticState, ProviderId, StateType>>();
-                        foreach (var type in s_documentScopeStateTypes)
-                        {
-                            current = current.Concat(GetAllExistingDiagnosticStates(type, languageOpt));
-                        }
-
-                        return current;
-                    }
-
-                    public IEnumerable<Tuple<DiagnosticState, ProviderId, StateType>> GetAllExistingDiagnosticStates(StateType type, string languageOpt)
-                    {
-                        if (languageOpt != null)
-                        {
-                            PerLanguageAnalyzersAndStates analyzersStates;
-                            if (_perLanguageAnalyzersAndStatesMap.TryGetValue(languageOpt, out analyzersStates))
-                            {
-                                return analyzersStates.GetAllExistingDiagnosticStates(type);
-                            }
-                            else
-                            {
-                                return SpecializedCollections.EmptyEnumerable<Tuple<DiagnosticState, ProviderId, StateType>>();
-                            }
-                        }
-
-                        // This might be a removed or closed document/project/solution.
-                        // Return all existing states.
-                        var current = SpecializedCollections.EmptyEnumerable<Tuple<DiagnosticState, ProviderId, StateType>>();
-                        foreach (var analyzersAndStates in _perLanguageAnalyzersAndStatesMap.Values)
-                        {
-                            current = current.Concat(analyzersAndStates.GetAllExistingDiagnosticStates(type));
-                        }
-
-                        return current;
-                    }
-
-                    public IEnumerable<KeyValuePair<DiagnosticAnalyzer, ProviderId>> GetAllProviderAndIds(string language)
-                    {
-                        var analyzersAndStates = this.GetOrCreatePerLanguageAnalyzersAndStates(language);
-                        return analyzersAndStates.GetAllProviderAndIds();
-                    }
-
-                    public DiagnosticState GetOrCreateDiagnosticState(StateType stateType, ProviderId providerId, DiagnosticAnalyzer provider, string language)
-                    {
-                        var analyzersAndStates = this.GetOrCreatePerLanguageAnalyzersAndStates(language);
-                        return analyzersAndStates.GetOrCreateDiagnosticState(stateType, providerId, provider);
-                    }
-
-                    public DiagnosticState GetDiagnosticState(StateType stateType, ProviderId providerId, string language)
-                    {
-                        var analyzersAndStates = this.GetOrCreatePerLanguageAnalyzersAndStates(language);
-                        return analyzersAndStates.GetDiagnosticState(stateType, providerId);
-                    }
-                }
-            }
-        }
-    }
-}

src/Features/Core/Diagnostics/DiagnosticAnalyzerService.cs

@@ -53,7 +53,7 @@ public ImmutableArray<DiagnosticDescriptor> GetDiagnosticDescriptors(DiagnosticA
 
         public void Reanalyze(Workspace workspace, IEnumerable<ProjectId> projectIds = null, IEnumerable<DocumentId> documentIds = null)
         {
-            DiagnosticIncrementalAnalyzer analyzer;
+            BaseDiagnosticIncrementalAnalyzer analyzer;
 
             var service = workspace.Services.GetService<ISolutionCrawlerService>();
             if (service != null && _map.TryGetValue(workspace, out analyzer))
@@ -62,13 +62,13 @@ public void Reanalyze(Workspace workspace, IEnumerable<ProjectId> projectIds = n
             }
         }
 
-        public Task<bool> TryGetDiagnosticsForSpanAsync(Document document, TextSpan range, List<DiagnosticData> diagnostics, CancellationToken cancellationToken)
+        public Task<bool> TryAppendDiagnosticsForSpanAsync(Document document, TextSpan range, List<DiagnosticData> diagnostics, CancellationToken cancellationToken)
         {
-            DiagnosticIncrementalAnalyzer analyzer;
+            BaseDiagnosticIncrementalAnalyzer analyzer;
             if (_map.TryGetValue(document.Project.Solution.Workspace, out analyzer))
             {
                 // always make sure that analyzer is called on background thread.
-                return Task.Run(async () => await analyzer.TryGetDiagnosticAsync(document, range, diagnostics, cancellationToken).ConfigureAwait(false), cancellationToken);
+                return Task.Run(async () => await analyzer.TryAppendDiagnosticsForSpanAsync(document, range, diagnostics, cancellationToken).ConfigureAwait(false), cancellationToken);
             }
 
             return SpecializedTasks.False;
@@ -76,11 +76,11 @@ public Task<bool> TryGetDiagnosticsForSpanAsync(Document document, TextSpan rang
 
         public Task<IEnumerable<DiagnosticData>> GetDiagnosticsForSpanAsync(Document document, TextSpan range, CancellationToken cancellationToken)
         {
-            DiagnosticIncrementalAnalyzer analyzer;
+            BaseDiagnosticIncrementalAnalyzer analyzer;
             if (_map.TryGetValue(document.Project.Solution.Workspace, out analyzer))
             {
                 // always make sure that analyzer is called on background thread.
-                return Task.Run(async () => await analyzer.GetDiagnosticsAsync(document, range, cancellationToken).ConfigureAwait(false), cancellationToken);
+                return Task.Run(async () => await analyzer.GetDiagnosticsForSpanAsync(document, range, cancellationToken).ConfigureAwait(false), cancellationToken);
             }
 
             return SpecializedTasks.EmptyEnumerable<DiagnosticData>();
@@ -88,7 +88,7 @@ public Task<IEnumerable<DiagnosticData>> GetDiagnosticsForSpanAsync(Document doc
 
         public Task<ImmutableArray<DiagnosticData>> GetCachedDiagnosticsAsync(Workspace workspace, ProjectId projectId = null, DocumentId documentId = null, CancellationToken cancellationToken = default(CancellationToken))
         {
-            DiagnosticIncrementalAnalyzer analyzer;
+            BaseDiagnosticIncrementalAnalyzer analyzer;
             if (_map.TryGetValue(workspace, out analyzer))
             {
                 return analyzer.GetCachedDiagnosticsAsync(workspace.CurrentSolution, projectId, documentId, cancellationToken);
@@ -99,7 +99,7 @@ public Task<ImmutableArray<DiagnosticData>> GetCachedDiagnosticsAsync(Workspace
 
         public Task<ImmutableArray<DiagnosticData>> GetSpecificCachedDiagnosticsAsync(Workspace workspace, object id, CancellationToken cancellationToken)
         {
-            DiagnosticIncrementalAnalyzer analyzer;
+            BaseDiagnosticIncrementalAnalyzer analyzer;
             if (_map.TryGetValue(workspace, out analyzer))
             {
                 return analyzer.GetSpecificCachedDiagnosticsAsync(workspace.CurrentSolution, id, cancellationToken);
@@ -110,7 +110,7 @@ public Task<ImmutableArray<DiagnosticData>> GetSpecificCachedDiagnosticsAsync(Wo
 
         public Task<ImmutableArray<DiagnosticData>> GetDiagnosticsAsync(Solution solution, ProjectId projectId = null, DocumentId documentId = null, CancellationToken cancellationToken = default(CancellationToken))
         {
-            DiagnosticIncrementalAnalyzer analyzer;
+            BaseDiagnosticIncrementalAnalyzer analyzer;
             if (_map.TryGetValue(solution.Workspace, out analyzer))
             {
                 return analyzer.GetDiagnosticsAsync(solution, projectId, documentId, cancellationToken);
@@ -121,7 +121,7 @@ public Task<ImmutableArray<DiagnosticData>> GetDiagnosticsAsync(Solution solutio
 
         public Task<ImmutableArray<DiagnosticData>> GetSpecificDiagnosticsAsync(Solution solution, object id, CancellationToken cancellationToken)
         {
-            DiagnosticIncrementalAnalyzer analyzer;
+            BaseDiagnosticIncrementalAnalyzer analyzer;
             if (_map.TryGetValue(solution.Workspace, out analyzer))
             {
                 return analyzer.GetSpecificDiagnosticsAsync(solution, id, cancellationToken);
@@ -133,7 +133,7 @@ public Task<ImmutableArray<DiagnosticData>> GetSpecificDiagnosticsAsync(Solution
         public Task<ImmutableArray<DiagnosticData>> GetDiagnosticsForIdsAsync(
             Solution solution, ProjectId projectId = null, DocumentId documentId = null, ImmutableHashSet<string> diagnosticIds = null, CancellationToken cancellationToken = default(CancellationToken))
         {
-            DiagnosticIncrementalAnalyzer analyzer;
+            BaseDiagnosticIncrementalAnalyzer analyzer;
             if (_map.TryGetValue(solution.Workspace, out analyzer))
             {
                 return analyzer.GetDiagnosticsForIdsAsync(solution, projectId, documentId, diagnosticIds, cancellationToken);
@@ -145,7 +145,7 @@ public Task<ImmutableArray<DiagnosticData>> GetSpecificDiagnosticsAsync(Solution
         public Task<ImmutableArray<DiagnosticData>> GetProjectDiagnosticsForIdsAsync(
             Solution solution, ProjectId projectId = null, ImmutableHashSet<string> diagnosticIds = null, CancellationToken cancellationToken = default(CancellationToken))
         {
-            DiagnosticIncrementalAnalyzer analyzer;
+            BaseDiagnosticIncrementalAnalyzer analyzer;
             if (_map.TryGetValue(solution.Workspace, out analyzer))
             {
                 return analyzer.GetProjectDiagnosticsForIdsAsync(solution, projectId, diagnosticIds, cancellationToken);

src/Features/Core/Diagnostics/DiagnosticAnalyzerService_IncrementalAnalyzer.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.Collections.Generic;
+using System.Collections.Immutable;
 using System.Runtime.CompilerServices;
+using System.Threading;
+using System.Threading.Tasks;
 using Microsoft.CodeAnalysis.Internal.Log;
 using Microsoft.CodeAnalysis.Options;
 using Microsoft.CodeAnalysis.Shared.Options;
+using Microsoft.CodeAnalysis.Simplification;
 using Microsoft.CodeAnalysis.SolutionCrawler;
+using Microsoft.CodeAnalysis.Text;
 using Roslyn.Utilities;
 
 namespace Microsoft.CodeAnalysis.Diagnostics
@@ -12,12 +19,12 @@ namespace Microsoft.CodeAnalysis.Diagnostics
     [ExportIncrementalAnalyzerProvider(highPriorityForActiveFile: true, workspaceKinds: new string[] { WorkspaceKind.Host, WorkspaceKind.Interactive })]
     internal partial class DiagnosticAnalyzerService : IIncrementalAnalyzerProvider
     {
-        private readonly ConditionalWeakTable<Workspace, DiagnosticIncrementalAnalyzer> _map;
-        private readonly ConditionalWeakTable<Workspace, DiagnosticIncrementalAnalyzer>.CreateValueCallback _createIncrementalAnalyzer;
+        private readonly ConditionalWeakTable<Workspace, BaseDiagnosticIncrementalAnalyzer> _map;
+        private readonly ConditionalWeakTable<Workspace, BaseDiagnosticIncrementalAnalyzer>.CreateValueCallback _createIncrementalAnalyzer;
 
         private DiagnosticAnalyzerService()
         {
-            _map = new ConditionalWeakTable<Workspace, DiagnosticIncrementalAnalyzer>();
+            _map = new ConditionalWeakTable<Workspace, BaseDiagnosticIncrementalAnalyzer>();
             _createIncrementalAnalyzer = CreateIncrementalAnalyzerCallback;
         }
 
@@ -30,26 +37,174 @@ public IIncrementalAnalyzer CreateIncrementalAnalyzer(Workspace workspace)
                 return null;
             }
 
-            return GetOrCreateIncrementalAnalyzerCore(workspace);
+            return GetOrCreateIncrementalAnalyzer(workspace);
         }
 
-        private DiagnosticIncrementalAnalyzer GetOrCreateIncrementalAnalyzerCore(Workspace workspace)
+        private BaseDiagnosticIncrementalAnalyzer GetOrCreateIncrementalAnalyzer(Workspace workspace)
         {
             return _map.GetValue(workspace, _createIncrementalAnalyzer);
         }
 
-        private DiagnosticIncrementalAnalyzer CreateIncrementalAnalyzerCallback(Workspace workspace)
+        private BaseDiagnosticIncrementalAnalyzer CreateIncrementalAnalyzerCallback(Workspace workspace)
         {
             // subscribe to active context changed event for new workspace
             workspace.DocumentActiveContextChanged += OnDocumentActiveContextChanged;
-
-            var correlationId = LogAggregator.GetNextId();
-            return new DiagnosticIncrementalAnalyzer(this, correlationId, workspace, _analyzerManager);
+            return new IncrementalAnalyzerDelegatee(this, workspace, _analyzerManager);
         }
 
         private void OnDocumentActiveContextChanged(object sender, DocumentEventArgs e)
         {
             Reanalyze(e.Document.Project.Solution.Workspace, documentIds: SpecializedCollections.SingletonEnumerable(e.Document.Id));
         }
+
+        // internal for testing
+        internal class IncrementalAnalyzerDelegatee : BaseDiagnosticIncrementalAnalyzer
+        {
+            private readonly Workspace _workspace;
+            private readonly AnalyzerManager _analyzerManager;
+            private readonly DiagnosticAnalyzerService _owner;
+
+            // v1 diagnostic engine
+            private readonly EngineV1.DiagnosticIncrementalAnalyzer _engineV1;
+
+            // v2 diagnostic engine - for now v1
+            private readonly EngineV2.DiagnosticIncrementalAnalyzer _engineV2;
+
+            public IncrementalAnalyzerDelegatee(DiagnosticAnalyzerService owner, Workspace workspace, AnalyzerManager analyzerManager)
+            {
+                _workspace = workspace;
+                _analyzerManager = analyzerManager;
+                _owner = owner;
+
+                var v1CorrelationId = LogAggregator.GetNextId();
+                _engineV1 = new EngineV1.DiagnosticIncrementalAnalyzer(_owner, v1CorrelationId, _workspace, _analyzerManager);
+
+                var v2CorrelationId = LogAggregator.GetNextId();
+                _engineV2 = new EngineV2.DiagnosticIncrementalAnalyzer(_owner, v2CorrelationId, _workspace, _analyzerManager);
+            }
+
+            #region IIncrementalAnalyzer
+            public override Task AnalyzeSyntaxAsync(Document document, CancellationToken cancellationToken)
+            {
+                return Analyzer.AnalyzeSyntaxAsync(document, cancellationToken);
+            }
+
+            public override Task AnalyzeDocumentAsync(Document document, SyntaxNode bodyOpt, CancellationToken cancellationToken)
+            {
+                return Analyzer.AnalyzeDocumentAsync(document, bodyOpt, cancellationToken);
+            }
+
+            public override Task AnalyzeProjectAsync(Project project, bool semanticsChanged, CancellationToken cancellationToken)
+            {
+                return Analyzer.AnalyzeProjectAsync(project, semanticsChanged, cancellationToken);
+            }
+
+            public override Task DocumentOpenAsync(Document document, CancellationToken cancellationToken)
+            {
+                return Analyzer.DocumentOpenAsync(document, cancellationToken);
+            }
+
+            public override Task DocumentResetAsync(Document document, CancellationToken cancellationToken)
+            {
+                return Analyzer.DocumentResetAsync(document, cancellationToken);
+            }
+
+            public override Task NewSolutionSnapshotAsync(Solution solution, CancellationToken cancellationToken)
+            {
+                return Analyzer.NewSolutionSnapshotAsync(solution, cancellationToken);
+            }
+
+            public override void RemoveDocument(DocumentId documentId)
+            {
+                Analyzer.RemoveDocument(documentId);
+            }
+
+            public override void RemoveProject(ProjectId projectId)
+            {
+                Analyzer.RemoveProject(projectId);
+            }
+
+            public override bool NeedsReanalysisOnOptionChanged(object sender, OptionChangedEventArgs e)
+            {
+                return e.Option.Feature == SimplificationOptions.PerLanguageFeatureName ||
+                       e.Option.Feature == SimplificationOptions.NonPerLanguageFeatureName ||
+                       e.Option == ServiceFeatureOnOffOptions.ClosedFileDiagnostic ||
+                       e.Option == InternalDiagnosticsOptions.UseDiagnosticEngineV2 ||
+                       Analyzer.NeedsReanalysisOnOptionChanged(sender, e);
+            }
+            #endregion
+
+            #region delegating methods from diagnostic analyzer service to each implementation of the engine
+            public override Task<ImmutableArray<DiagnosticData>> GetCachedDiagnosticsAsync(Solution solution, ProjectId projectId = null, DocumentId documentId = null, CancellationToken cancellationToken = default(CancellationToken))
+            {
+                return Analyzer.GetCachedDiagnosticsAsync(solution, projectId, documentId, cancellationToken);
+            }
+
+            public override Task<ImmutableArray<DiagnosticData>> GetSpecificCachedDiagnosticsAsync(Solution solution, object id, CancellationToken cancellationToken)
+            {
+                return Analyzer.GetSpecificCachedDiagnosticsAsync(solution, id, cancellationToken);
+            }
+
+            public override Task<ImmutableArray<DiagnosticData>> GetDiagnosticsAsync(Solution solution, ProjectId projectId = null, DocumentId documentId = null, CancellationToken cancellationToken = default(CancellationToken))
+            {
+                return Analyzer.GetDiagnosticsAsync(solution, projectId, documentId, cancellationToken);
+            }
+
+            public override Task<ImmutableArray<DiagnosticData>> GetSpecificDiagnosticsAsync(Solution solution, object id, CancellationToken cancellationToken)
+            {
+                return Analyzer.GetSpecificDiagnosticsAsync(solution, id, cancellationToken);
+            }
+
+            public override Task<ImmutableArray<DiagnosticData>> GetDiagnosticsForIdsAsync(Solution solution, ProjectId projectId = null, DocumentId documentId = null, ImmutableHashSet<string> diagnosticIds = null, CancellationToken cancellationToken = default(CancellationToken))
+            {
+                return Analyzer.GetDiagnosticsForIdsAsync(solution, projectId, documentId, diagnosticIds, cancellationToken);
+            }
+
+            public override Task<ImmutableArray<DiagnosticData>> GetProjectDiagnosticsForIdsAsync(Solution solution, ProjectId projectId = null, ImmutableHashSet<string> diagnosticIds = null, CancellationToken cancellationToken = default(CancellationToken))
+            {
+                return Analyzer.GetProjectDiagnosticsForIdsAsync(solution, projectId, diagnosticIds, cancellationToken);
+            }
+
+            public override Task<bool> TryAppendDiagnosticsForSpanAsync(Document document, TextSpan range, List<DiagnosticData> diagnostics, CancellationToken cancellationToken)
+            {
+                return Analyzer.TryAppendDiagnosticsForSpanAsync(document, range, diagnostics, cancellationToken);
+            }
+
+            public override Task<IEnumerable<DiagnosticData>> GetDiagnosticsForSpanAsync(Document document, TextSpan range, CancellationToken cancellationToken)
+            {
+                return Analyzer.GetDiagnosticsForSpanAsync(document, range, cancellationToken);
+            }
+            #endregion
+
+            public void TurnOff(bool useV2)
+            {
+                var turnedOffAnalyzer = GetAnalyzer(!useV2);
+
+                foreach (var project in _workspace.CurrentSolution.Projects)
+                {
+                    foreach (var document in project.Documents)
+                    {
+                        turnedOffAnalyzer.RemoveDocument(document.Id);
+                    }
+
+                    turnedOffAnalyzer.RemoveProject(project.Id);
+                }
+            }
+
+            // internal for testing
+            internal BaseDiagnosticIncrementalAnalyzer Analyzer
+            {
+                get
+                {
+                    var option = _workspace.Options.GetOption(InternalDiagnosticsOptions.UseDiagnosticEngineV2);
+                    return GetAnalyzer(option);
+                }
+            }
+
+            private BaseDiagnosticIncrementalAnalyzer GetAnalyzer(bool useV2)
+            {
+                return useV2 ? (BaseDiagnosticIncrementalAnalyzer)_engineV2 : _engineV1;
+            }
+        }
     }
 }

src/Features/Core/Diagnostics/DiagnosticProviderMetadata.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.Collections.Generic;
-using Microsoft.CodeAnalysis.LanguageServices;
+using Microsoft.CodeAnalysis.Host.Mef;
 using Roslyn.Utilities;
 
 namespace Microsoft.CodeAnalysis.Diagnostics

src/Features/Core/Diagnostics/AbstractSyntaxNodeAnalyzerService.cs → src/Features/Core/Diagnostics/EngineV1/AbstractSyntaxNodeAnalyzerService.cs

@@ -5,7 +5,7 @@
 using System.Collections.Immutable;
 using System.Threading;
 
-namespace Microsoft.CodeAnalysis.Diagnostics
+namespace Microsoft.CodeAnalysis.Diagnostics.EngineV1
 {
     internal abstract class AbstractSyntaxNodeAnalyzerService<TLanguageKindEnum> : ISyntaxNodeAnalyzerService where TLanguageKindEnum : struct
     {

src/Features/Core/Diagnostics/DiagnosticAnalyzerCategory.cs → src/Features/Core/Diagnostics/EngineV1/DiagnosticAnalyzerCategory.cs

@@ -2,7 +2,7 @@
 
 using System;
 
-namespace Microsoft.CodeAnalysis.Diagnostics
+namespace Microsoft.CodeAnalysis.Diagnostics.EngineV1
 {
     [Flags]
     internal enum DiagnosticAnalyzerCategory

src/Features/Core/Diagnostics/DiagnosticAnalyzerDriver.cs → src/Features/Core/Diagnostics/EngineV1/DiagnosticAnalyzerDriver.cs

@@ -8,6 +8,7 @@
 using System.Runtime.CompilerServices;
 using System.Threading;
 using System.Threading.Tasks;
+using Microsoft.CodeAnalysis.Diagnostics.Log;
 using Microsoft.CodeAnalysis.ErrorReporting;
 using Microsoft.CodeAnalysis.GeneratedCodeRecognition;
 using Microsoft.CodeAnalysis.Internal.Log;
@@ -16,9 +17,9 @@
 using Microsoft.CodeAnalysis.Text;
 using Roslyn.Utilities;
 
-namespace Microsoft.CodeAnalysis.Diagnostics
+namespace Microsoft.CodeAnalysis.Diagnostics.EngineV1
 {
-    internal partial class DiagnosticAnalyzerDriver
+    internal class DiagnosticAnalyzerDriver
     {
         private readonly Document _document;
 
@@ -602,12 +603,4 @@ private bool CatchAnalyzerException(Exception e, DiagnosticAnalyzer analyzer, bo
             return true;
         }
     }
-
-    internal static class AnalyzerDriverResources
-    {
-        internal static string AnalyzerFailure => FeaturesResources.UserDiagnosticAnalyzerFailure;
-        internal static string AnalyzerThrows => FeaturesResources.UserDiagnosticAnalyzerThrows;
-        internal static string ArgumentElementCannotBeNull => FeaturesResources.ArgumentElementCannotBeNull;
-        internal static string ArgumentCannotBeEmpty => FeaturesResources.ArgumentCannotBeEmpty;
-    }
 }

src/Features/Core/Diagnostics/EngineV1/DiagnosticIncrementalAnalyzer.DiagnosticAnalyzersAndStates.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.Collections.Concurrent;
+using System.Collections.Generic;
+using System.Collections.Immutable;
+using System.IO;
+using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+using Roslyn.Utilities;
+
+namespace Microsoft.CodeAnalysis.Diagnostics.EngineV1
+{
+    using ProviderId = Int32;
+
+    internal partial class DiagnosticIncrementalAnalyzer
+    {
+        /// <summary>
+        /// Maintains all MEF-imported diagnostic analyzers (with diagnostic states), which are enabled for all projects in the workspace,
+        /// and a map of per-project diagnostic analyzers (with diagnostic states).
+        /// </summary>
+        private partial class DiagnosticAnalyzersAndStates
+        {
+            private const string UserDiagnosticsPrefixTableName = "<UserDiagnostics>";
+
+            private readonly DiagnosticIncrementalAnalyzer _owner;
+            private readonly WorkspaceAnalyzersAndStates _sharedAnalyzersAndStates;
+            private readonly ConcurrentDictionary<ProjectId, ProjectAnalyzersAndStates> _projectAnalyzersAndStatesMap;
+
+            public readonly Workspace Workspace;
+
+            public DiagnosticAnalyzersAndStates(DiagnosticIncrementalAnalyzer owner, Workspace workspace, AnalyzerManager analyzerManager)
+            {
+                _owner = owner;
+                _sharedAnalyzersAndStates = new WorkspaceAnalyzersAndStates(analyzerManager);
+                _projectAnalyzersAndStatesMap = new ConcurrentDictionary<ProjectId, ProjectAnalyzersAndStates>();
+
+                this.Workspace = workspace;
+            }
+
+            public IEnumerable<Tuple<DiagnosticState, ProviderId, StateType>> GetAllExistingDiagnosticStates(ProjectId projectId)
+            {
+                var project = this.Workspace.CurrentSolution.GetProject(projectId);
+                var language = project != null ? project.Language : null;
+                return GetAllExistingDiagnosticStates(projectId, language);
+            }
+
+            public IEnumerable<Tuple<DiagnosticState, ProviderId, StateType>> GetAllExistingDiagnosticStates(ProjectId projectId, string language)
+            {
+                var current = _sharedAnalyzersAndStates.GetAllExistingDiagnosticStates(language);
+
+                ProjectAnalyzersAndStates projectAnalyzersAndStates;
+                if (_projectAnalyzersAndStatesMap.TryGetValue(projectId, out projectAnalyzersAndStates) &&
+                    projectAnalyzersAndStates != null)
+                {
+                    current = current.Concat(projectAnalyzersAndStates.GetAllExistingDiagnosticStates());
+                }
+
+                return current;
+            }
+
+            public IEnumerable<Tuple<DiagnosticState, ProviderId, StateType>> GetAllExistingDiagnosticStates(ProjectId projectId, StateType type)
+            {
+                var project = this.Workspace.CurrentSolution.GetProject(projectId);
+                var language = project != null ? project.Language : null;
+                return GetAllExistingDiagnosticStates(projectId, type, language);
+            }
+
+            public IEnumerable<Tuple<DiagnosticState, ProviderId, StateType>> GetAllExistingDiagnosticStates(ProjectId projectId, StateType type, string language)
+            {
+                var current = _sharedAnalyzersAndStates.GetAllExistingDiagnosticStates(type, language);
+
+                ProjectAnalyzersAndStates projectAnalyzersAndStates;
+                if (_projectAnalyzersAndStatesMap.TryGetValue(projectId, out projectAnalyzersAndStates) &&
+                    projectAnalyzersAndStates != null)
+                {
+                    current = current.Concat(projectAnalyzersAndStates.GetAllExistingDiagnosticStates(type));
+                }
+
+                return current;
+            }
+
+            public IEnumerable<KeyValuePair<DiagnosticAnalyzer, ProviderId>> GetAllExistingProviderAndIds(Project project)
+            {
+                var current = _sharedAnalyzersAndStates.GetAllProviderAndIds(project.Language);
+
+                ProjectAnalyzersAndStates projectAnalyzersAndStates;
+                if (_projectAnalyzersAndStatesMap.TryGetValue(project.Id, out projectAnalyzersAndStates) &&
+                    projectAnalyzersAndStates != null)
+                {
+                    current = current.Concat(projectAnalyzersAndStates.GetAllProviderAndIds());
+                }
+
+                return current;
+            }
+
+            public async Task<IEnumerable<KeyValuePair<DiagnosticAnalyzer, ProviderId>>> GetAllProviderAndIdsAsync(Project project, CancellationToken cancellationToken)
+            {
+                var current = _sharedAnalyzersAndStates.GetAllProviderAndIds(project.Language);
+
+                var projectAnalyzersAndStates = await GetOrCreateProjectAnalyzersAndStatesAsync(project, cancellationToken).ConfigureAwait(false);
+                if (projectAnalyzersAndStates != null)
+                {
+                    current = current.Concat(projectAnalyzersAndStates.GetAllProviderAndIds());
+                }
+
+                return current;
+            }
+
+            public DiagnosticState GetOrCreateDiagnosticState(StateType stateType, ProviderId providerId, DiagnosticAnalyzer provider, ProjectId projectId, string language)
+            {
+                Contract.ThrowIfFalse(providerId >= 0);
+
+                var sharedAnalyzersCount = _sharedAnalyzersAndStates.GetAnalyzerCount(language);
+                if (providerId < sharedAnalyzersCount)
+                {
+                    return _sharedAnalyzersAndStates.GetOrCreateDiagnosticState(stateType, providerId, provider, language);
+                }
+
+                ProjectAnalyzersAndStates projectAnalyzersAndStates;
+                if (!_projectAnalyzersAndStatesMap.TryGetValue(projectId, out projectAnalyzersAndStates) ||
+                    projectAnalyzersAndStates == null)
+                {
+                    return null;
+                }
+
+                return projectAnalyzersAndStates.GetOrCreateDiagnosticState(stateType, providerId, provider);
+            }
+
+            internal static DiagnosticState GetOrCreateDiagnosticState(DiagnosticState[,] diagnosticStateMaps, StateType stateType, int providerIndex, ProviderId providerId, DiagnosticAnalyzer provider, string language)
+            {
+                Contract.ThrowIfFalse(providerIndex >= 0);
+                Contract.ThrowIfFalse(providerIndex < diagnosticStateMaps.GetLength(1));
+
+                if (diagnosticStateMaps[(int)stateType, providerIndex] == null)
+                {
+                    var nameAndVersion = GetUniqueDiagnosticStateNameAndVersion(stateType, providerId, provider);
+
+                    var name = nameAndVersion.Item1;
+                    var version = nameAndVersion.Item2;
+                    diagnosticStateMaps[(int)stateType, providerIndex] = new DiagnosticState(name, version, language);
+
+#if DEBUG
+                    // Ensure diagnostic state name is indeed unique.
+                    foreach (var type in s_documentScopeStateTypes)
+                    {
+                        for (var pId = 0; pId < diagnosticStateMaps.GetLength(1); pId++)
+                        {
+                            if (diagnosticStateMaps[(int)type, pId] != null)
+                            {
+                                Contract.ThrowIfFalse(name != diagnosticStateMaps[(int)type, pId].Name ||
+                                    (stateType == type &&
+                                     (pId == providerIndex || language != diagnosticStateMaps[(int)type, pId].Language)));
+                            }
+                        }
+                    }
+#endif
+                }
+
+                return diagnosticStateMaps[(int)stateType, providerIndex];
+            }
+
+            /// <summary>
+            /// Get the unique state name for the given {type, provider} tuple.
+            /// Note that this name is used by the underlying persistence stream of the corresponding <see cref="DiagnosticState"/> to Read/Write diagnostic data into the stream.
+            /// If any two distinct {type, provider} tuples have the same diagnostic state name, we will end up sharing the persistence stream between them, leading to duplicate/missing/incorrect diagnostic data.
+            /// </summary>
+            private static ValueTuple<string, VersionStamp> GetUniqueDiagnosticStateNameAndVersion(StateType type, ProviderId providerId, DiagnosticAnalyzer provider)
+            {
+                Contract.ThrowIfNull(provider);
+
+                // Get the unique ID for given diagnostic analyzer.
+                // note that we also put version stamp so that we can detect changed provider
+                var providerType = provider.GetType();
+                var location = providerType.Assembly.Location;
+
+                return ValueTuple.Create(UserDiagnosticsPrefixTableName + "_" + type + "_" + providerType.AssemblyQualifiedName, GetProviderVersion(location));
+            }
+
+            private static VersionStamp GetProviderVersion(string path)
+            {
+                if (path == null || !File.Exists(path))
+                {
+                    return VersionStamp.Default;
+                }
+
+                return VersionStamp.Create(File.GetLastWriteTimeUtc(path));
+            }
+
+            public DiagnosticState GetDiagnosticState(StateType stateType, ProviderId providerId, ProjectId projectId, string language)
+            {
+                Contract.ThrowIfFalse(providerId >= 0);
+
+                var sharedAnalyzersCount = _sharedAnalyzersAndStates.GetAnalyzerCount(language);
+                if (providerId < sharedAnalyzersCount)
+                {
+                    return _sharedAnalyzersAndStates.GetDiagnosticState(stateType, providerId, language);
+                }
+
+                ProjectAnalyzersAndStates projectAnalyzersAndStates;
+                if (!_projectAnalyzersAndStatesMap.TryGetValue(projectId, out projectAnalyzersAndStates) ||
+                    projectAnalyzersAndStates == null)
+                {
+                    return null;
+                }
+
+                return projectAnalyzersAndStates.GetDiagnosticState(stateType, providerId);
+            }
+
+            public bool RemoveProjectAnalyzersAndStates(ProjectId projectId)
+            {
+                ProjectAnalyzersAndStates projectAnalyzersAndStates;
+                return _projectAnalyzersAndStatesMap.TryRemove(projectId, out projectAnalyzersAndStates);
+            }
+
+            private async Task<ProjectAnalyzersAndStates> GetOrCreateProjectAnalyzersAndStatesAsync(Project project, CancellationToken cancellationToken)
+            {
+                // Update per-project analyzers if needed.
+                IEnumerable<Tuple<DiagnosticState, ProviderId, StateType>> removedStates;
+                ProjectAnalyzersAndStates projectAnalyzersAndStates = this.GetOrCreateProjectAnalyzersAndStates(project, out removedStates);
+                if (removedStates.Any())
+                {
+                    // Analyzers got updated, so clear the existing persistent states.
+                    await _owner.RemoveCacheDataAsync(project, removedStates, cancellationToken).ConfigureAwait(false);
+                }
+
+                return projectAnalyzersAndStates;
+            }
+
+            private ProjectAnalyzersAndStates GetOrCreateProjectAnalyzersAndStates(Project project,
+                out IEnumerable<Tuple<DiagnosticState, ProviderId, StateType>> removedStates)
+            {
+                removedStates = SpecializedCollections.EmptyEnumerable<Tuple<DiagnosticState, ProviderId, StateType>>();
+
+                var newAnalyzersBuilder = ImmutableArray.CreateBuilder<KeyValuePair<string, IEnumerable<DiagnosticAnalyzer>>>();
+                foreach (var analyzerReference in project.AnalyzerReferences)
+                {
+                    // Filter out duplicate analyzer references.
+                    if (_sharedAnalyzersAndStates.HasAnalyzerReference(analyzerReference, project.Language))
+                    {
+                        continue;
+                    }
+
+                    // Get analyzers in the analyzer reference for the given project language.
+                    // Filter out duplicate analyzers.
+                    // NOTE: The HasAnalyzerReference check above to filter out duplicate analyzer references works only for duplicate AnalyzerFileReference with the same underlying assembly.
+                    // However, we can also have AnalyzerImageReference, which might contain the same DiagnosticAnalyzer instance across different AnalyzerImageReference instances
+                    // and we want to avoid duplicate analyzers for that case. Hence we apply the HasAnalyzer filter here.
+                    var analyzers = analyzerReference.GetAnalyzers(project.Language)
+                        .Where(a => !_sharedAnalyzersAndStates.HasAnalyzer(a, project.Language));
+
+                    if (analyzers.Any())
+                    {
+                        newAnalyzersBuilder.Add(KeyValuePair.Create(analyzerReference.Display, analyzers));
+                    }
+                }
+
+                var newAnalyzers = newAnalyzersBuilder.ToImmutable();
+                ProjectAnalyzersAndStates newProjectAnalyzersAndStates = null;
+
+                ProjectAnalyzersAndStates currentProjectAnalyzersAndStates;
+                if (_projectAnalyzersAndStatesMap.TryGetValue(project.Id, out currentProjectAnalyzersAndStates))
+                {
+                    var newAnalyzersCount = newAnalyzers.Sum(kv => kv.Value.Count());
+                    if (currentProjectAnalyzersAndStates != null && currentProjectAnalyzersAndStates.AnalyzerCount == newAnalyzersCount)
+                    {
+                        Contract.ThrowIfFalse(currentProjectAnalyzersAndStates.AnalyzerCount > 0);
+
+                        // Project still has the same number of analyzers, does the saved projectAnalyzersAndStates has the same set of analyzers?
+                        var hasSameAnalyzers = true;
+                        foreach (var analyzerPair in newAnalyzers)
+                        {
+                            foreach (var analyzer in analyzerPair.Value)
+                            {
+                                if (!currentProjectAnalyzersAndStates.HasAnalyzer(analyzer))
+                                {
+                                    hasSameAnalyzers = false;
+                                    break;
+                                }
+                            }
+                        }
+
+                        if (hasSameAnalyzers)
+                        {
+                            return currentProjectAnalyzersAndStates;
+                        }
+                    }
+                }
+                else
+                {
+                    currentProjectAnalyzersAndStates = null;
+                }
+
+                if (currentProjectAnalyzersAndStates != null)
+                {
+                    removedStates = currentProjectAnalyzersAndStates.GetAllExistingDiagnosticStates();
+                }
+
+                var workspaceAnalyzersCount = _sharedAnalyzersAndStates.GetAnalyzerCount(project.Language);
+                newProjectAnalyzersAndStates = ProjectAnalyzersAndStates.CreateIfAnyAnalyzers(newAnalyzers, workspaceAnalyzersCount, project.Language);
+                return _projectAnalyzersAndStatesMap.AddOrUpdate(project.Id, newProjectAnalyzersAndStates, (k, c) => newProjectAnalyzersAndStates);
+            }
+        }
+    }
+}

src/Features/Core/Diagnostics/EngineV1/DiagnosticIncrementalAnalyzer.DiagnosticState.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.Collections.Generic;
+using System.Collections.Immutable;
+using System.Collections.ObjectModel;
+using System.IO;
+using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+using Microsoft.CodeAnalysis.Host;
+using Microsoft.CodeAnalysis.Shared.Extensions;
+using Microsoft.CodeAnalysis.SolutionCrawler.State;
+using Microsoft.CodeAnalysis.Text;
+using Roslyn.Utilities;
+
+namespace Microsoft.CodeAnalysis.Diagnostics.EngineV1
+{
+    internal partial class DiagnosticIncrementalAnalyzer
+    {
+        internal class DiagnosticState : AbstractAnalyzerState<object, object, AnalysisData>
+        {
+            private const int FormatVersion = 5;
+
+            private readonly string _stateName;
+            private readonly VersionStamp _version;
+            private readonly string _language;
+
+            public DiagnosticState(string stateName, VersionStamp version, string language)
+            {
+                Contract.ThrowIfNull(stateName);
+
+                _stateName = stateName;
+                _version = version;
+                _language = language;
+            }
+
+            internal string Name
+            {
+                get { return _stateName; }
+            }
+
+            internal string Language
+            {
+                get { return _language; }
+            }
+
+            protected override object GetCacheKey(object value)
+            {
+                var document = value as Document;
+                if (document != null)
+                {
+                    return document.Id;
+                }
+
+                var project = (Project)value;
+                return project.Id;
+            }
+
+            protected override Solution GetSolution(object value)
+            {
+                var document = value as Document;
+                if (document != null)
+                {
+                    return document.Project.Solution;
+                }
+
+                var project = (Project)value;
+                return project.Solution;
+            }
+
+            protected override bool ShouldCache(object value)
+            {
+                var document = value as Document;
+                if (document != null)
+                {
+                    return document.IsOpen();
+                }
+
+                var project = (Project)value;
+                return project.Solution.Workspace.GetOpenDocumentIds(project.Id).Any();
+            }
+
+            protected override Task<Stream> ReadStreamAsync(IPersistentStorage storage, object value, CancellationToken cancellationToken)
+            {
+                var document = value as Document;
+                if (document != null)
+                {
+                    return storage.ReadStreamAsync(document, _stateName, cancellationToken);
+                }
+
+                var project = (Project)value;
+                return storage.ReadStreamAsync(project, _stateName, cancellationToken);
+            }
+
+            protected override AnalysisData TryGetExistingData(Stream stream, object value, CancellationToken cancellationToken)
+            {
+                var document = value as Document;
+                if (document != null)
+                {
+                    return TryGetExistingData(stream, document.Project, document, cancellationToken);
+                }
+
+                var project = (Project)value;
+                return TryGetExistingData(stream, project, null, cancellationToken);
+            }
+
+            private AnalysisData TryGetExistingData(Stream stream, Project project, Document document, CancellationToken cancellationToken)
+            {
+                var list = SharedPools.Default<List<DiagnosticData>>().AllocateAndClear();
+                try
+                {
+                    using (var reader = new ObjectReader(stream))
+                    {
+                        var format = reader.ReadInt32();
+                        if (format != FormatVersion)
+                        {
+                            return null;
+                        }
+
+                        // saved data is for same provider of different version of dll
+                        var providerVersion = VersionStamp.ReadFrom(reader);
+                        if (providerVersion != _version)
+                        {
+                            return null;
+                        }
+
+                        var textVersion = VersionStamp.ReadFrom(reader);
+                        var dataVersion = VersionStamp.ReadFrom(reader);
+                        if (textVersion == VersionStamp.Default || dataVersion == VersionStamp.Default)
+                        {
+                            return null;
+                        }
+
+                        AppendItems(reader, project, document, list, cancellationToken);
+
+                        return new AnalysisData(textVersion, dataVersion, list.ToImmutableArray<DiagnosticData>());
+                    }
+                }
+                catch (Exception)
+                {
+                    return null;
+                }
+                finally
+                {
+                    SharedPools.Default<List<DiagnosticData>>().ClearAndFree(list);
+                }
+            }
+
+            private void AppendItems(ObjectReader reader, Project project, Document document, List<DiagnosticData> list, CancellationToken cancellationToken)
+            {
+                var count = reader.ReadInt32();
+
+                for (var i = 0; i < count; i++)
+                {
+                    cancellationToken.ThrowIfCancellationRequested();
+
+                    var id = reader.ReadString();
+                    var category = reader.ReadString();
+
+                    var message = reader.ReadString();
+                    var messageFormat = reader.ReadString();
+                    var title = reader.ReadString();
+                    var description = reader.ReadString();
+                    var helpLink = reader.ReadString();
+                    var severity = (DiagnosticSeverity)reader.ReadInt32();
+                    var defaultSeverity = (DiagnosticSeverity)reader.ReadInt32();
+                    var isEnabledByDefault = reader.ReadBoolean();
+                    var warningLevel = reader.ReadInt32();
+
+                    var start = reader.ReadInt32();
+                    var length = reader.ReadInt32();
+                    var textSpan = new TextSpan(start, length);
+
+                    var originalFile = reader.ReadString();
+                    var originalStartLine = reader.ReadInt32();
+                    var originalStartColumn = reader.ReadInt32();
+                    var originalEndLine = reader.ReadInt32();
+                    var originalEndColumn = reader.ReadInt32();
+
+                    var mappedFile = reader.ReadString();
+                    var mappedStartLine = reader.ReadInt32();
+                    var mappedStartColumn = reader.ReadInt32();
+                    var mappedEndLine = reader.ReadInt32();
+                    var mappedEndColumn = reader.ReadInt32();
+
+                    var customTagsCount = reader.ReadInt32();
+                    var customTags = GetCustomTags(reader, customTagsCount);
+
+                    list.Add(new DiagnosticData(
+                        id, category, message, messageFormat, severity, defaultSeverity, isEnabledByDefault, warningLevel, customTags,
+                        project.Solution.Workspace, project.Id, document != null ? document.Id : null, document != null ? textSpan : (TextSpan?)null,
+                        mappedFile, mappedStartLine, mappedStartColumn, mappedEndLine, mappedEndColumn,
+                        originalFile, originalStartLine, originalStartColumn, originalEndLine, originalEndColumn,
+                        title: title,
+                        description: description,
+                        helpLink: helpLink));
+                }
+            }
+
+            private static IReadOnlyList<string> GetCustomTags(ObjectReader reader, int count)
+            {
+                if (count > 0)
+                {
+                    var tags = new List<string>(count);
+                    for (var i = 0; i < count; i++)
+                    {
+                        tags.Add(reader.ReadString());
+                    }
+
+                    return new ReadOnlyCollection<string>(tags);
+                }
+
+                return SpecializedCollections.EmptyReadOnlyList<string>();
+            }
+
+            protected override Task<bool> WriteStreamAsync(IPersistentStorage storage, object value, Stream stream, CancellationToken cancellationToken)
+            {
+                var document = value as Document;
+                if (document != null)
+                {
+                    return storage.WriteStreamAsync(document, _stateName, stream, cancellationToken);
+                }
+
+                var project = (Project)value;
+                return storage.WriteStreamAsync(project, _stateName, stream, cancellationToken);
+            }
+
+            protected override void WriteTo(Stream stream, AnalysisData data, CancellationToken cancellationToken)
+            {
+                using (var writer = new ObjectWriter(stream, cancellationToken: cancellationToken))
+                {
+                    writer.WriteInt32(FormatVersion);
+                    _version.WriteTo(writer);
+                    data.TextVersion.WriteTo(writer);
+                    data.DataVersion.WriteTo(writer);
+
+                    writer.WriteInt32(data.Items.Length);
+
+                    foreach (var item in data.Items)
+                    {
+                        cancellationToken.ThrowIfCancellationRequested();
+
+                        writer.WriteString(item.Id);
+                        writer.WriteString(item.Category);
+
+                        writer.WriteString(item.Message);
+                        writer.WriteString(item.MessageFormat);
+                        writer.WriteString(item.Title);
+                        writer.WriteString(item.Description);
+                        writer.WriteString(item.HelpLink);
+                        writer.WriteInt32((int)item.Severity);
+                        writer.WriteInt32((int)item.DefaultSeverity);
+                        writer.WriteBoolean(item.IsEnabledByDefault);
+                        writer.WriteInt32(item.WarningLevel);
+
+                        if (item.HasTextSpan)
+                        {
+                            // document state
+                            writer.WriteInt32(item.TextSpan.Start);
+                            writer.WriteInt32(item.TextSpan.Length);
+                        }
+                        else
+                        {
+                            // project state
+                            writer.WriteInt32(0);
+                            writer.WriteInt32(0);
+                        }
+
+                        writer.WriteString(item.OriginalFilePath);
+                        writer.WriteInt32(item.OriginalStartLine);
+                        writer.WriteInt32(item.OriginalStartColumn);
+                        writer.WriteInt32(item.OriginalEndLine);
+                        writer.WriteInt32(item.OriginalEndColumn);
+
+                        writer.WriteString(item.MappedFilePath);
+                        writer.WriteInt32(item.MappedStartLine);
+                        writer.WriteInt32(item.MappedStartColumn);
+                        writer.WriteInt32(item.MappedEndLine);
+                        writer.WriteInt32(item.MappedEndColumn);
+
+                        writer.WriteInt32(item.CustomTags.Count);
+                        foreach (var tag in item.CustomTags)
+                        {
+                            writer.WriteString(tag);
+                        }
+                    }
+                }
+            }
+        }
+    }
+}

src/Features/Core/Diagnostics/EngineV1/DiagnosticIncrementalAnalyzer.IncrementalAnalyzer.AnalyzerExecutor.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.Collections.Immutable;
+using System.Diagnostics;
+using System.Threading.Tasks;
+using Microsoft.CodeAnalysis.ErrorReporting;
+using Roslyn.Utilities;
+
+namespace Microsoft.CodeAnalysis.Diagnostics.EngineV1
+{
+    using ProviderId = Int32;
+
+    internal partial class DiagnosticIncrementalAnalyzer
+    {
+        /// <summary>
+        /// AnalyzerExecutor returns analyzed data without side effect. 
+        /// it might uses cache to skip unnecessary duplicate analysis, but it will never update any internal state such as state
+        /// 
+        /// this is not finished form. as refactoring going on, this class will become more stateless in respect to caller, and less dependency on owner.
+        /// </summary>
+        internal class AnalyzerExecutor
+        {
+            private readonly DiagnosticIncrementalAnalyzer _owner;
+
+            public AnalyzerExecutor(DiagnosticIncrementalAnalyzer owner)
+            {
+                _owner = owner;
+            }
+
+            public async Task<AnalysisData> GetSyntaxAnalysisDataAsync(
+                DiagnosticAnalyzer provider, ProviderId providerId, VersionArgument versions, DiagnosticAnalyzerDriver analyzerDriver)
+            {
+                try
+                {
+                    var document = analyzerDriver.Document;
+                    var cancellationToken = analyzerDriver.CancellationToken;
+
+                    var state = AnalyzersAndState.GetOrCreateDiagnosticState(StateType.Syntax, providerId, provider, document.Project.Id, document.Project.Language);
+                    var existingData = await state.TryGetExistingDataAsync(document, cancellationToken).ConfigureAwait(false);
+
+                    if (CheckSyntaxVersions(document, existingData, versions))
+                    {
+                        return existingData;
+                    }
+
+                    var diagnosticData = await GetSyntaxDiagnosticsAsync(providerId, provider, analyzerDriver).ConfigureAwait(false);
+                    return new AnalysisData(versions.TextVersion, versions.DataVersion, GetExistingItems(existingData), diagnosticData.AsImmutableOrEmpty());
+                }
+                catch (Exception e) when (FatalError.ReportUnlessCanceled(e))
+                {
+                    throw ExceptionUtilities.Unreachable;
+                }
+            }
+
+            public async Task<AnalysisData> GetDocumentAnalysisDataAsync(
+                DiagnosticAnalyzer provider, ProviderId providerId, VersionArgument versions, DiagnosticAnalyzerDriver analyzerDrvier)
+            {
+                try
+                {
+                    var document = analyzerDrvier.Document;
+                    var cancellationToken = analyzerDrvier.CancellationToken;
+
+                    var state = AnalyzersAndState.GetOrCreateDiagnosticState(StateType.Document, providerId, provider, document.Project.Id, document.Project.Language);
+                    var existingData = await state.TryGetExistingDataAsync(document, cancellationToken).ConfigureAwait(false);
+
+                    if (CheckSemanticVersions(document, existingData, versions))
+                    {
+                        return existingData;
+                    }
+
+                    var diagnosticData = await GetSemanticDiagnosticsAsync(providerId, provider, analyzerDrvier).ConfigureAwait(false);
+                    return new AnalysisData(versions.TextVersion, versions.DataVersion, GetExistingItems(existingData), diagnosticData.AsImmutableOrEmpty());
+                }
+                catch (Exception e) when (FatalError.ReportUnlessCanceled(e))
+                {
+                    throw ExceptionUtilities.Unreachable;
+                }
+            }
+
+            public async Task<AnalysisData> GetDocumentBodyAnalysisDataAsync(
+                DiagnosticAnalyzer provider, ProviderId providerId, VersionArgument versions, DiagnosticAnalyzerDriver analyzerDriver,
+                SyntaxNode root, SyntaxNode member, int memberId, bool supportsSemanticInSpan, MemberRangeMap.MemberRanges ranges)
+            {
+                try
+                {
+                    var document = analyzerDriver.Document;
+                    var cancellationToken = analyzerDriver.CancellationToken;
+
+                    var state = AnalyzersAndState.GetOrCreateDiagnosticState(StateType.Document, providerId, provider, document.Project.Id, document.Project.Language);
+                    var existingData = await state.TryGetExistingDataAsync(document, cancellationToken).ConfigureAwait(false);
+
+                    ImmutableArray<DiagnosticData> diagnosticData;
+                    if (supportsSemanticInSpan && CanUseDocumentState(existingData, ranges.TextVersion, versions.DataVersion))
+                    {
+                        var memberDxData = await GetSemanticDiagnosticsAsync(providerId, provider, analyzerDriver).ConfigureAwait(false);
+
+                        diagnosticData = _owner.UpdateDocumentDiagnostics(existingData, ranges.Ranges, memberDxData.AsImmutableOrEmpty(), root.SyntaxTree, member, memberId);
+                        ValidateMemberDiagnostics(providerId, provider, document, root, diagnosticData);
+                    }
+                    else
+                    {
+                        // if we can't re-use existing document state, only option we have is updating whole document state here.
+                        var dx = await GetSemanticDiagnosticsAsync(providerId, provider, analyzerDriver).ConfigureAwait(false);
+                        diagnosticData = dx.AsImmutableOrEmpty();
+                    }
+
+                    return new AnalysisData(versions.TextVersion, versions.DataVersion, GetExistingItems(existingData), diagnosticData);
+                }
+                catch (Exception e) when (FatalError.ReportUnlessCanceled(e))
+                {
+                    throw ExceptionUtilities.Unreachable;
+                }
+            }
+
+            public async Task<AnalysisData> GetProjectAnalysisDataAsync(
+                DiagnosticAnalyzer provider, ProviderId providerId, VersionArgument versions, DiagnosticAnalyzerDriver analyzerDriver)
+            {
+                try
+                {
+                    var project = analyzerDriver.Project;
+                    var cancellationToken = analyzerDriver.CancellationToken;
+
+                    var state = AnalyzersAndState.GetOrCreateDiagnosticState(StateType.Project, providerId, provider, project.Id, project.Language);
+                    var existingData = await state.TryGetExistingDataAsync(project, cancellationToken).ConfigureAwait(false);
+
+                    if (CheckSemanticVersions(project, existingData, versions))
+                    {
+                        return existingData;
+                    }
+
+                    // TODO: remove ForceAnalyzeAllDocuments at some point
+                    var diagnosticData = await GetProjectDiagnosticsAsync(providerId, provider, analyzerDriver, _owner.ForceAnalyzeAllDocuments).ConfigureAwait(false);
+                    return new AnalysisData(VersionStamp.Default, versions.DataVersion, GetExistingItems(existingData), diagnosticData.AsImmutableOrEmpty());
+                }
+                catch (Exception e) when (FatalError.ReportUnlessCanceled(e))
+                {
+                    throw ExceptionUtilities.Unreachable;
+                }
+            }
+
+            private DiagnosticAnalyzersAndStates AnalyzersAndState
+            {
+                get { return _owner._analyzersAndState; }
+            }
+
+            private bool CanUseDocumentState(AnalysisData existingData, VersionStamp textVersion, VersionStamp dataVersion)
+            {
+                if (existingData == null)
+                {
+                    return false;
+                }
+
+                // make sure data stored in the cache is one from its previous text update
+                return existingData.DataVersion.Equals(dataVersion) && existingData.TextVersion.Equals(textVersion);
+            }
+
+            private static ImmutableArray<DiagnosticData> GetExistingItems(AnalysisData existingData)
+            {
+                if (existingData == null)
+                {
+                    return ImmutableArray<DiagnosticData>.Empty;
+                }
+
+                return existingData.Items;
+            }
+
+            [Conditional("DEBUG")]
+            private void ValidateMemberDiagnostics(ProviderId providerId, DiagnosticAnalyzer provider, Document document, SyntaxNode root, ImmutableArray<DiagnosticData> diagnostics)
+            {
+#if RANGE
+                var documentBasedDriver = new DiagnosticAnalyzerDriver(document, root.FullSpan, root, CancellationToken.None);
+                var expected = GetSemanticDiagnosticsAsync(providerId, provider, documentBasedDriver).WaitAndGetResult(documentBasedDriver.CancellationToken) ?? SpecializedCollections.EmptyEnumerable<DiagnosticData>();
+                Contract.Requires(diagnostics.SetEquals(expected));
+#endif
+            }
+        }
+    }
+}

src/Features/Core/Diagnostics/DiagnosticAnalyzerService.NestedTypes.cs → src/Features/Core/Diagnostics/EngineV1/DiagnosticIncrementalAnalyzer.NestedTypes.cs

@@ -3,9 +3,9 @@
 using System.Collections.Immutable;
 using Roslyn.Utilities;
 
-namespace Microsoft.CodeAnalysis.Diagnostics
+namespace Microsoft.CodeAnalysis.Diagnostics.EngineV1
 {
-    internal partial class DiagnosticAnalyzerService
+    internal partial class DiagnosticIncrementalAnalyzer
     {
         public class AnalysisData
         {

src/Features/Core/Diagnostics/EngineV1/DiagnosticIncrementalAnalyzer.ProjectAnalyzersAndStates.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.Collections.Generic;
+using System.Collections.Immutable;
+using System.Linq;
+using Roslyn.Utilities;
+
+namespace Microsoft.CodeAnalysis.Diagnostics.EngineV1
+{
+    using ProviderId = Int32;
+
+    internal partial class DiagnosticIncrementalAnalyzer
+    {
+        private partial class DiagnosticAnalyzersAndStates
+        {
+            /// <summary>
+            /// Maintains per-project diagnostic analyzers and the corresponding diagnostic states.
+            /// </summary>
+            private class ProjectAnalyzersAndStates
+            {
+                private readonly ImmutableDictionary<string, ImmutableDictionary<DiagnosticAnalyzer, ProviderId>> _analyzerIdMap;
+                private readonly DiagnosticState[,] _diagnosticStateMaps;
+                private readonly int _startAnalyzerId;
+                private readonly int _analyzerCount;
+                private readonly string _projectLanguage;
+
+                public static ProjectAnalyzersAndStates CreateIfAnyAnalyzers(IEnumerable<KeyValuePair<string, IEnumerable<DiagnosticAnalyzer>>> projectSpecificAnalyzers, int sharedWorkspaceAnalyzersCount, string projectLanguage)
+                {
+                    // Make sure we have at least one analyzer.
+                    if (projectSpecificAnalyzers == null || !projectSpecificAnalyzers.Any())
+                    {
+                        return null;
+                    }
+
+                    return new ProjectAnalyzersAndStates(projectSpecificAnalyzers, sharedWorkspaceAnalyzersCount, projectLanguage);
+                }
+
+                private ProjectAnalyzersAndStates(IEnumerable<KeyValuePair<string, IEnumerable<DiagnosticAnalyzer>>> projectSpecificAnalyzers, int sharedWorkspaceAnalyzersCount, string projectLanguage)
+                {
+                    Contract.ThrowIfFalse(projectSpecificAnalyzers != null && projectSpecificAnalyzers.Any());
+
+                    _startAnalyzerId = sharedWorkspaceAnalyzersCount;
+                    _projectLanguage = projectLanguage;
+                    _analyzerIdMap = CreateAnalyzerIdMap(projectSpecificAnalyzers, _startAnalyzerId);
+                    _analyzerCount = _analyzerIdMap.Values.Flatten().Count();
+                    Contract.ThrowIfFalse(_analyzerCount > 0);
+
+                    _diagnosticStateMaps = new DiagnosticState[s_stateTypeCount, _analyzerCount];
+                }
+
+                private static ImmutableDictionary<string, ImmutableDictionary<DiagnosticAnalyzer, ProviderId>> CreateAnalyzerIdMap(
+                    IEnumerable<KeyValuePair<string, IEnumerable<DiagnosticAnalyzer>>> projectSpecificAnalyzers, int startAnalyzerId)
+                {
+                    var index = startAnalyzerId;
+                    var map = ImmutableDictionary.CreateBuilder<string, ImmutableDictionary<DiagnosticAnalyzer, ProviderId>>();
+
+                    foreach (var analyzerList in projectSpecificAnalyzers)
+                    {
+                        var analyzerMap = ImmutableDictionary.CreateBuilder<DiagnosticAnalyzer, ProviderId>();
+
+                        foreach (var analyzer in analyzerList.Value)
+                        {
+                            Contract.ThrowIfNull(analyzer);
+                            analyzerMap.Add(analyzer, index++);
+                        }
+
+                        if (map.ContainsKey(analyzerList.Key))
+                        {
+                            map[analyzerList.Key] = map[analyzerList.Key].AddRange(analyzerMap);
+                        }
+                        else
+                        {
+                            map.Add(analyzerList.Key, analyzerMap.ToImmutable());
+                        }
+                    }
+
+                    return map.ToImmutable();
+                }
+
+                public int AnalyzerCount
+                {
+                    get
+                    {
+                        Contract.ThrowIfFalse(_analyzerCount > 0);
+                        return _analyzerCount;
+                    }
+                }
+
+                public IEnumerable<Tuple<DiagnosticState, ProviderId, StateType>> GetAllExistingDiagnosticStates()
+                {
+                    var current = SpecializedCollections.EmptyEnumerable<Tuple<DiagnosticState, ProviderId, StateType>>();
+                    foreach (var type in s_documentScopeStateTypes)
+                    {
+                        current = current.Concat(GetAllExistingDiagnosticStates(type));
+                    }
+
+                    return current;
+                }
+
+                public IEnumerable<Tuple<DiagnosticState, ProviderId, StateType>> GetAllExistingDiagnosticStates(StateType type)
+                {
+                    foreach (var analyzerAndId in _analyzerIdMap.Values.Flatten())
+                    {
+                        var state = _diagnosticStateMaps[(int)type, analyzerAndId.Value - _startAnalyzerId];
+                        yield return Tuple.Create(state, analyzerAndId.Value, type);
+                    }
+                }
+
+                public IEnumerable<KeyValuePair<DiagnosticAnalyzer, ProviderId>> GetAllProviderAndIds()
+                {
+                    return _analyzerIdMap.Values.Flatten();
+                }
+
+                public DiagnosticState GetOrCreateDiagnosticState(StateType stateType, ProviderId providerId, DiagnosticAnalyzer provider)
+                {
+                    Contract.ThrowIfFalse(providerId >= _startAnalyzerId);
+                    Contract.ThrowIfFalse(providerId < _startAnalyzerId + this.AnalyzerCount);
+
+                    return DiagnosticAnalyzersAndStates.GetOrCreateDiagnosticState(_diagnosticStateMaps, stateType, providerId - _startAnalyzerId, providerId, provider, _projectLanguage);
+                }
+
+                public DiagnosticState GetDiagnosticState(StateType stateType, ProviderId providerId)
+                {
+                    Contract.ThrowIfFalse(providerId >= _startAnalyzerId);
+                    Contract.ThrowIfFalse(providerId < _startAnalyzerId + this.AnalyzerCount);
+
+                    return _diagnosticStateMaps[(int)stateType, providerId - _startAnalyzerId];
+                }
+
+                public bool HasAnalyzer(DiagnosticAnalyzer analyzer)
+                {
+                    Contract.ThrowIfNull(analyzer);
+                    return _analyzerIdMap.Values.Any(dict => dict.ContainsKey(analyzer));
+                }
+            }
+        }
+    }
+}

src/Features/Core/Diagnostics/DiagnosticAnalyzerService.StateType.cs → src/Features/Core/Diagnostics/EngineV1/DiagnosticIncrementalAnalyzer.StateType.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.
 
-namespace Microsoft.CodeAnalysis.Diagnostics
+namespace Microsoft.CodeAnalysis.Diagnostics.EngineV1
 {
-    internal partial class DiagnosticAnalyzerService
+    internal partial class DiagnosticIncrementalAnalyzer
     {
         public enum StateType : int
         {

src/Features/Core/Diagnostics/DiagnosticAnalyzerService.ProjectAnalyzersAndStates.cs → src/Features/Core/Diagnostics/EngineV1/DiagnosticIncrementalAnalyzer.WorkspaceAnalyzersAndStates.PerLanguageAnalyzersAndStates.cs

@@ -6,74 +6,58 @@
 using System.Linq;
 using Roslyn.Utilities;
 
-namespace Microsoft.CodeAnalysis.Diagnostics
+namespace Microsoft.CodeAnalysis.Diagnostics.EngineV1
 {
     using ProviderId = Int32;
 
-    internal partial class DiagnosticAnalyzerService
+    internal partial class DiagnosticIncrementalAnalyzer
     {
-        internal partial class DiagnosticIncrementalAnalyzer
+        private partial class DiagnosticAnalyzersAndStates
         {
-            private partial class DiagnosticAnalyzersAndStates
+            private partial class WorkspaceAnalyzersAndStates
             {
                 /// <summary>
-                /// Maintains per-project diagnostic analyzers and the corresponding diagnostic states.
+                /// Maintains all workspace diagnostic analyzers (with diagnostic states) for a specific language.
                 /// </summary>
-                private class ProjectAnalyzersAndStates
+                private class PerLanguageAnalyzersAndStates
                 {
-                    private readonly ImmutableDictionary<string, ImmutableDictionary<DiagnosticAnalyzer, ProviderId>> _analyzerIdMap;
-                    private readonly DiagnosticState[,] _diagnosticStateMaps;
-                    private readonly int _startAnalyzerId;
+                    private readonly string _language;
+                    private readonly ImmutableDictionary<string, ImmutableDictionary<DiagnosticAnalyzer, ProviderId>> _diagnosticAnalyzerIdMap;
                     private readonly int _analyzerCount;
-                    private readonly string _projectLanguage;
-
-                    public static ProjectAnalyzersAndStates CreateIfAnyAnalyzers(IEnumerable<KeyValuePair<string, IEnumerable<DiagnosticAnalyzer>>> projectSpecificAnalyzers, int sharedWorkspaceAnalyzersCount, string projectLanguage)
-                    {
-                        // Make sure we have at least one analyzer.
-                        if (projectSpecificAnalyzers == null || !projectSpecificAnalyzers.Any())
-                        {
-                            return null;
-                        }
-
-                        return new ProjectAnalyzersAndStates(projectSpecificAnalyzers, sharedWorkspaceAnalyzersCount, projectLanguage);
-                    }
+                    private readonly DiagnosticState[,] _diagnosticStateMaps;
 
-                    private ProjectAnalyzersAndStates(IEnumerable<KeyValuePair<string, IEnumerable<DiagnosticAnalyzer>>> projectSpecificAnalyzers, int sharedWorkspaceAnalyzersCount, string projectLanguage)
+                    public PerLanguageAnalyzersAndStates(AnalyzerManager analyzerManager, string language)
                     {
-                        Contract.ThrowIfFalse(projectSpecificAnalyzers != null && projectSpecificAnalyzers.Any());
-
-                        _startAnalyzerId = sharedWorkspaceAnalyzersCount;
-                        _projectLanguage = projectLanguage;
-                        _analyzerIdMap = CreateAnalyzerIdMap(projectSpecificAnalyzers, _startAnalyzerId);
-                        _analyzerCount = _analyzerIdMap.Values.Flatten().Count();
-                        Contract.ThrowIfFalse(_analyzerCount > 0);
+                        _language = language;
 
+                        // TODO: dynamically re-order providers so that cheap one runs first and slower runs later.
+                        _diagnosticAnalyzerIdMap = CreateAnalyzerIdMap(analyzerManager, language);
+                        _analyzerCount = _diagnosticAnalyzerIdMap.Values.Flatten().Count();
                         _diagnosticStateMaps = new DiagnosticState[s_stateTypeCount, _analyzerCount];
                     }
 
                     private static ImmutableDictionary<string, ImmutableDictionary<DiagnosticAnalyzer, ProviderId>> CreateAnalyzerIdMap(
-                        IEnumerable<KeyValuePair<string, IEnumerable<DiagnosticAnalyzer>>> projectSpecificAnalyzers, int startAnalyzerId)
+                        AnalyzerManager analyzerManager, string language)
                     {
-                        var index = startAnalyzerId;
+                        var index = 0;
                         var map = ImmutableDictionary.CreateBuilder<string, ImmutableDictionary<DiagnosticAnalyzer, ProviderId>>();
 
-                        foreach (var analyzerList in projectSpecificAnalyzers)
+                        foreach (var kv in analyzerManager.GetHostDiagnosticAnalyzersPerReference(language))
                         {
-                            var analyzerMap = ImmutableDictionary.CreateBuilder<DiagnosticAnalyzer, ProviderId>();
+                            var perAnalyzerMap = ImmutableDictionary.CreateBuilder<DiagnosticAnalyzer, ProviderId>();
 
-                            foreach (var analyzer in analyzerList.Value)
-                            {
-                                Contract.ThrowIfNull(analyzer);
-                                analyzerMap.Add(analyzer, index++);
-                            }
+                            var referenceIdentity = kv.Key;
+                            var perLanguageAnalyzers = kv.Value;
 
-                            if (map.ContainsKey(analyzerList.Key))
+                            if (perLanguageAnalyzers.Length > 0)
                             {
-                                map[analyzerList.Key] = map[analyzerList.Key].AddRange(analyzerMap);
-                            }
-                            else
-                            {
-                                map.Add(analyzerList.Key, analyzerMap.ToImmutable());
+                                foreach (var analyzer in perLanguageAnalyzers)
+                                {
+                                    var analyzerId = index++;
+                                    perAnalyzerMap.Add(analyzer, analyzerId);
+                                }
+
+                                map.Add(referenceIdentity, perAnalyzerMap.ToImmutable());
                             }
                         }
 
@@ -82,58 +66,58 @@ private ProjectAnalyzersAndStates(IEnumerable<KeyValuePair<string, IEnumerable<D
 
                     public int AnalyzerCount
                     {
-                        get
-                        {
-                            Contract.ThrowIfFalse(_analyzerCount > 0);
-                            return _analyzerCount;
-                        }
+                        get { return _analyzerCount; }
                     }
 
-                    public IEnumerable<Tuple<DiagnosticState, ProviderId, StateType>> GetAllExistingDiagnosticStates()
+                    public bool HasAnalyzerReference(AnalyzerReference analyzerReference)
                     {
-                        var current = SpecializedCollections.EmptyEnumerable<Tuple<DiagnosticState, ProviderId, StateType>>();
-                        foreach (var type in s_documentScopeStateTypes)
+                        Contract.ThrowIfNull(analyzerReference);
+
+                        if (analyzerReference is AnalyzerFileReference)
                         {
-                            current = current.Concat(GetAllExistingDiagnosticStates(type));
+                            // Filter out duplicate analyzer references with same assembly name/full path.
+                            return analyzerReference.Display != null && _diagnosticAnalyzerIdMap.ContainsKey(analyzerReference.Display);
                         }
+                        else
+                        {
+                            // For non-file references, we will check individual DiagnosticAnalyzer instances for duplicates.
+                            return false;
+                        }
+                    }
 
-                        return current;
+                    public bool HasAnalyzer(DiagnosticAnalyzer analyzer)
+                    {
+                        Contract.ThrowIfNull(analyzer);
+                        return _diagnosticAnalyzerIdMap.Values.Any(dict => dict.ContainsKey(analyzer));
                     }
 
                     public IEnumerable<Tuple<DiagnosticState, ProviderId, StateType>> GetAllExistingDiagnosticStates(StateType type)
                     {
-                        foreach (var analyzerAndId in _analyzerIdMap.Values.Flatten())
+                        foreach (var analyzerAndId in _diagnosticAnalyzerIdMap.Values.Flatten())
                         {
-                            var state = _diagnosticStateMaps[(int)type, analyzerAndId.Value - _startAnalyzerId];
-                            yield return Tuple.Create(state, analyzerAndId.Value, type);
+                            yield return Tuple.Create(_diagnosticStateMaps[(int)type, analyzerAndId.Value], analyzerAndId.Value, type);
                         }
                     }
 
                     public IEnumerable<KeyValuePair<DiagnosticAnalyzer, ProviderId>> GetAllProviderAndIds()
                     {
-                        return _analyzerIdMap.Values.Flatten();
+                        return _diagnosticAnalyzerIdMap.Values.Flatten();
                     }
 
                     public DiagnosticState GetOrCreateDiagnosticState(StateType stateType, ProviderId providerId, DiagnosticAnalyzer provider)
                     {
-                        Contract.ThrowIfFalse(providerId >= _startAnalyzerId);
-                        Contract.ThrowIfFalse(providerId < _startAnalyzerId + this.AnalyzerCount);
+                        Contract.ThrowIfFalse(providerId >= 0);
+                        Contract.ThrowIfFalse(providerId < this.AnalyzerCount);
 
-                        return DiagnosticAnalyzersAndStates.GetOrCreateDiagnosticState(_diagnosticStateMaps, stateType, providerId - _startAnalyzerId, providerId, provider, _projectLanguage);
+                        return DiagnosticAnalyzersAndStates.GetOrCreateDiagnosticState(_diagnosticStateMaps, stateType, providerId, providerId, provider, _language);
                     }
 
                     public DiagnosticState GetDiagnosticState(StateType stateType, ProviderId providerId)
                     {
-                        Contract.ThrowIfFalse(providerId >= _startAnalyzerId);
-                        Contract.ThrowIfFalse(providerId < _startAnalyzerId + this.AnalyzerCount);
-
-                        return _diagnosticStateMaps[(int)stateType, providerId - _startAnalyzerId];
-                    }
+                        Contract.ThrowIfFalse(providerId >= 0);
+                        Contract.ThrowIfFalse(providerId < this.AnalyzerCount);
 
-                    public bool HasAnalyzer(DiagnosticAnalyzer analyzer)
-                    {
-                        Contract.ThrowIfNull(analyzer);
-                        return _analyzerIdMap.Values.Any(dict => dict.ContainsKey(analyzer));
+                        return _diagnosticStateMaps[(int)stateType, providerId];
                     }
                 }
             }

src/Features/Core/Diagnostics/EngineV1/DiagnosticIncrementalAnalyzer.WorkspaceAnalyzersAndStates.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.Collections.Generic;
+using System.Collections.Immutable;
+using System.Linq;
+using Roslyn.Utilities;
+
+namespace Microsoft.CodeAnalysis.Diagnostics.EngineV1
+{
+    using ProviderId = Int32;
+
+    internal partial class DiagnosticIncrementalAnalyzer
+    {
+        private partial class DiagnosticAnalyzersAndStates
+        {
+            /// <summary>
+            /// Maintains all workspace diagnostic analyzers (with diagnostic states), which are enabled for all projects in the workspace.
+            /// </summary>
+            private partial class WorkspaceAnalyzersAndStates
+            {
+                private readonly AnalyzerManager _analyzerManager;
+                private ImmutableDictionary<string, PerLanguageAnalyzersAndStates> _perLanguageAnalyzersAndStatesMap;
+
+                public WorkspaceAnalyzersAndStates(AnalyzerManager analyzerManager)
+                {
+                    _analyzerManager = analyzerManager;
+                    _perLanguageAnalyzersAndStatesMap = ImmutableDictionary<string, PerLanguageAnalyzersAndStates>.Empty;
+                }
+
+                private static PerLanguageAnalyzersAndStates CreatePerLanguageAnalyzersAndStates(string language, WorkspaceAnalyzersAndStates @this)
+                {
+                    return new PerLanguageAnalyzersAndStates(@this._analyzerManager, language);
+                }
+
+                private PerLanguageAnalyzersAndStates GetOrCreatePerLanguageAnalyzersAndStates(string language)
+                {
+                    return ImmutableInterlocked.GetOrAdd(ref _perLanguageAnalyzersAndStatesMap, language, CreatePerLanguageAnalyzersAndStates, this);
+                }
+
+                public int GetAnalyzerCount(string language)
+                {
+                    var analyzersAndStates = this.GetOrCreatePerLanguageAnalyzersAndStates(language);
+                    return analyzersAndStates.AnalyzerCount;
+                }
+
+                public bool HasAnalyzerReference(AnalyzerReference analyzerReference, string language)
+                {
+                    var analyzersAndStates = this.GetOrCreatePerLanguageAnalyzersAndStates(language);
+                    return analyzersAndStates.HasAnalyzerReference(analyzerReference);
+                }
+
+                public bool HasAnalyzer(DiagnosticAnalyzer analyzer, string language)
+                {
+                    if (analyzer == null)
+                    {
+                        return false;
+                    }
+
+                    var analyzersAndStates = this.GetOrCreatePerLanguageAnalyzersAndStates(language);
+                    return analyzersAndStates.HasAnalyzer(analyzer);
+                }
+
+                public IEnumerable<Tuple<DiagnosticState, ProviderId, StateType>> GetAllExistingDiagnosticStates(string languageOpt)
+                {
+                    var current = SpecializedCollections.EmptyEnumerable<Tuple<DiagnosticState, ProviderId, StateType>>();
+                    foreach (var type in s_documentScopeStateTypes)
+                    {
+                        current = current.Concat(GetAllExistingDiagnosticStates(type, languageOpt));
+                    }
+
+                    return current;
+                }
+
+                public IEnumerable<Tuple<DiagnosticState, ProviderId, StateType>> GetAllExistingDiagnosticStates(StateType type, string languageOpt)
+                {
+                    if (languageOpt != null)
+                    {
+                        PerLanguageAnalyzersAndStates analyzersStates;
+                        if (_perLanguageAnalyzersAndStatesMap.TryGetValue(languageOpt, out analyzersStates))
+                        {
+                            return analyzersStates.GetAllExistingDiagnosticStates(type);
+                        }
+                        else
+                        {
+                            return SpecializedCollections.EmptyEnumerable<Tuple<DiagnosticState, ProviderId, StateType>>();
+                        }
+                    }
+
+                    // This might be a removed or closed document/project/solution.
+                    // Return all existing states.
+                    var current = SpecializedCollections.EmptyEnumerable<Tuple<DiagnosticState, ProviderId, StateType>>();
+                    foreach (var analyzersAndStates in _perLanguageAnalyzersAndStatesMap.Values)
+                    {
+                        current = current.Concat(analyzersAndStates.GetAllExistingDiagnosticStates(type));
+                    }
+
+                    return current;
+                }
+
+                public IEnumerable<KeyValuePair<DiagnosticAnalyzer, ProviderId>> GetAllProviderAndIds(string language)
+                {
+                    var analyzersAndStates = this.GetOrCreatePerLanguageAnalyzersAndStates(language);
+                    return analyzersAndStates.GetAllProviderAndIds();
+                }
+
+                public DiagnosticState GetOrCreateDiagnosticState(StateType stateType, ProviderId providerId, DiagnosticAnalyzer provider, string language)
+                {
+                    var analyzersAndStates = this.GetOrCreatePerLanguageAnalyzersAndStates(language);
+                    return analyzersAndStates.GetOrCreateDiagnosticState(stateType, providerId, provider);
+                }
+
+                public DiagnosticState GetDiagnosticState(StateType stateType, ProviderId providerId, string language)
+                {
+                    var analyzersAndStates = this.GetOrCreatePerLanguageAnalyzersAndStates(language);
+                    return analyzersAndStates.GetDiagnosticState(stateType, providerId);
+                }
+            }
+        }
+    }
+}

src/Features/Core/Diagnostics/ISyntaxNodeAnalyzerService.cs → src/Features/Core/Diagnostics/EngineV1/ISyntaxNodeAnalyzerService.cs

@@ -5,7 +5,7 @@
 using System.Threading;
 using Microsoft.CodeAnalysis.Host;
 
-namespace Microsoft.CodeAnalysis.Diagnostics
+namespace Microsoft.CodeAnalysis.Diagnostics.EngineV1
 {
     internal interface ISyntaxNodeAnalyzerService : ILanguageService
     {

src/Features/Core/Diagnostics/MemberRangeMap.cs → src/Features/Core/Diagnostics/EngineV1/MemberRangeMap.cs

@@ -11,7 +11,7 @@
 using Microsoft.CodeAnalysis.Text;
 using Roslyn.Utilities;
 
-namespace Microsoft.CodeAnalysis.Diagnostics
+namespace Microsoft.CodeAnalysis.Diagnostics.EngineV1
 {
     using ProviderId = Int32;
 

src/Features/Core/Diagnostics/IAnalyzerDriverService.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.Collections.Generic;
 using System.Collections.Immutable;
 using System.Threading;
 using Microsoft.CodeAnalysis.Host;

src/Features/Core/Diagnostics/IDiagnosticAnalyzerService.cs

@@ -54,7 +54,7 @@ internal interface IDiagnosticAnalyzerService
         /// it will return true if it was able to return all up-to-date diagnostics.
         ///  otherwise, false indicating there are some missing diagnostics in the diagnostic list
         /// </summary>
-        Task<bool> TryGetDiagnosticsForSpanAsync(Document document, TextSpan range, List<DiagnosticData> diagnostics, CancellationToken cancellationToken);
+        Task<bool> TryAppendDiagnosticsForSpanAsync(Document document, TextSpan range, List<DiagnosticData> diagnostics, CancellationToken cancellationToken);
 
         /// <summary>
         /// return up to date diagnostics for the given span for the document

src/EditorFeatures/Core/Implementation/Diagnostics/InternalDiagnosticsOptions.cs → src/Features/Core/Diagnostics/InternalDiagnosticsOptions.cs

@@ -2,7 +2,7 @@
 
 using Microsoft.CodeAnalysis.Options;
 
-namespace Microsoft.CodeAnalysis.Editor.Implementation.Diagnostics
+namespace Microsoft.CodeAnalysis.Diagnostics
 {
     internal static class InternalDiagnosticsOptions
     {
@@ -10,5 +10,8 @@ internal static class InternalDiagnosticsOptions
 
         [ExportOption]
         public static readonly Option<bool> BlueSquiggleForBuildDiagnostic = new Option<bool>(OptionName, "Blue Squiggle For Build Diagnostic", defaultValue: false);
+
+        [ExportOption]
+        public static readonly Option<bool> UseDiagnosticEngineV2 = new Option<bool>(OptionName, "Use Diagnostic Engine V2", defaultValue: false);
     }
 }

src/Features/Core/Diagnostics/DiagnosticAnalyzerLogger.cs → src/Features/Core/Diagnostics/Log/DiagnosticAnalyzerLogger.cs

@@ -8,7 +8,7 @@
 using Microsoft.CodeAnalysis.Internal.Log;
 using Roslyn.Utilities;
 
-namespace Microsoft.CodeAnalysis.Diagnostics
+namespace Microsoft.CodeAnalysis.Diagnostics.Log
 {
     internal class DiagnosticAnalyzerLogger
     {

src/Features/Core/Diagnostics/DiagnosticLogAggregator.cs → src/Features/Core/Diagnostics/Log/DiagnosticLogAggregator.cs

@@ -5,7 +5,7 @@
 using System.Collections.Immutable;
 using Microsoft.CodeAnalysis.Internal.Log;
 
-namespace Microsoft.CodeAnalysis.Diagnostics
+namespace Microsoft.CodeAnalysis.Diagnostics.Log
 {
     internal class DiagnosticLogAggregator : LogAggregator
     {

src/Features/Core/Diagnostics/DiagnosticLogger.cs → src/Features/Core/Diagnostics/Log/DiagnosticLogger.cs

@@ -2,7 +2,7 @@
 
 using Microsoft.CodeAnalysis.Internal.Log;
 
-namespace Microsoft.CodeAnalysis.Diagnostics
+namespace Microsoft.CodeAnalysis.Diagnostics.Log
 {
     internal static class DiagnosticLogger
     {

src/Features/Core/Shared/Extensions/DiagnosticAnalyzerExtensions.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 Microsoft.CodeAnalysis.Diagnostics;
+using Microsoft.CodeAnalysis.Diagnostics.EngineV1;
 
 namespace Microsoft.CodeAnalysis.Shared.Extensions
 {

src/Features/Core/SolutionCrawler/SolutionCrawlerLogger.cs

@@ -247,7 +247,7 @@ public static void LogIncrementalAnalyzerProcessorStatistics(int correlationId,
 
             foreach (var analyzer in analyzers)
             {
-                var diagIncrementalAnalyzer = analyzer as DiagnosticAnalyzerService.DiagnosticIncrementalAnalyzer;
+                var diagIncrementalAnalyzer = analyzer as BaseDiagnosticIncrementalAnalyzer;
                 if (diagIncrementalAnalyzer != null)
                 {
                     diagIncrementalAnalyzer.LogAnalyzerCountSummary();

src/Features/Core/SolutionCrawler/WorkCoordinator.cs

@@ -138,6 +138,14 @@ private void OnOptionChanged(object sender, OptionChangedEventArgs e)
                     return;
                 }
 
+                // TODO: remove this once prototype is done
+                //       it is here just because it was convenient to add per workspace option change monitoring 
+                //       for incremental analyzer
+                if (e.Option == Diagnostics.InternalDiagnosticsOptions.UseDiagnosticEngineV2)
+                {
+                    _documentAndProjectWorkerProcessor.ChangeDiagnosticsEngine((bool)e.Value);
+                }
+
                 ReanalyzeOnOptionChange(sender, e);
             }
 

src/Features/VisualBasic/Diagnostics/VisualBasicSyntaxNodeAnalyzerService.vb

 ' Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
 
-Imports System.Collections.Immutable
 Imports System.Composition
-Imports Microsoft.CodeAnalysis.Diagnostics
+Imports Microsoft.CodeAnalysis.Diagnostics.EngineV1
 Imports Microsoft.CodeAnalysis.Host.Mef
 
 Namespace Microsoft.CodeAnalysis.VisualBasic.Diagnostics

src/VisualStudio/Core/Def/Implementation/PreviewPane/PreviewPane.xaml.cs

@@ -6,6 +6,7 @@
 using System.Windows.Documents;
 using System.Windows.Navigation;
 using Microsoft.CodeAnalysis.Diagnostics;
+using Microsoft.CodeAnalysis.Diagnostics.Log;
 using Microsoft.VisualStudio.LanguageServices.Implementation.Utilities;
 using Microsoft.VisualStudio.Text.Differencing;