Remove unnecessary language tracking in the diagnostic service (#77100)

src/LanguageServer/Protocol/Features/Diagnostics/EngineV2/DiagnosticIncrementalAnalyzer.StateManager.HostStates.cs

@@ -45,7 +45,7 @@ static HostAnalyzerStateSets CreateLanguageSpecificAnalyzerMap(HostAnalyzerState
                     var analyzersPerReference = state.HostAnalyzers.GetOrCreateHostDiagnosticAnalyzersPerReference(language);
 
                     var (hostAnalyzerCollection, projectAnalyzerCollection) = GetAnalyzerCollections(analyzersPerReference, state.ReferenceIdsToRedirect);
-                    var analyzerMap = CreateStateSetMap(language, projectAnalyzerCollection, hostAnalyzerCollection, includeWorkspacePlaceholderAnalyzers: true);
+                    var analyzerMap = CreateStateSetMap(projectAnalyzerCollection, hostAnalyzerCollection, includeWorkspacePlaceholderAnalyzers: true);
 
                     return new HostAnalyzerStateSets(analyzerMap);
                 }

src/LanguageServer/Protocol/Features/Diagnostics/EngineV2/DiagnosticIncrementalAnalyzer.StateManager.ProjectStates.cs

@@ -86,7 +86,7 @@ private ProjectAnalyzerStateSets CreateProjectStateSets(Project project)
                     return ProjectAnalyzerStateSets.Default;
                 }
 
-                var newMap = CreateStateSetMap(project.Language, analyzersPerReference.Values, [], includeWorkspacePlaceholderAnalyzers: false);
+                var newMap = CreateStateSetMap(analyzersPerReference.Values, [], includeWorkspacePlaceholderAnalyzers: false);
                 var skippedAnalyzersInfo = project.GetSkippedAnalyzersInfo(_analyzerInfoCache);
                 return new ProjectAnalyzerStateSets(project.AnalyzerReferences, analyzersPerReference, newMap, skippedAnalyzersInfo);
             }

src/LanguageServer/Protocol/Features/Diagnostics/EngineV2/DiagnosticIncrementalAnalyzer.StateManager.cs

@@ -69,15 +69,6 @@ public IEnumerable<StateSet> GetStateSets(ProjectId projectId)
                     : hostStateSets;
             }
 
-            /// <summary>
-            /// Return <see cref="StateSet"/>s for the given <see cref="Project"/>.
-            /// This will never create new <see cref="StateSet"/> but will return ones already created.
-            /// Difference with <see cref="GetStateSets(ProjectId)"/> is that 
-            /// this will only return <see cref="StateSet"/>s that have same language as <paramref name="project"/>.
-            /// </summary>
-            public IEnumerable<StateSet> GetStateSets(Project project)
-                => GetStateSets(project.Id).Where(s => s.Language == project.Language);
-
             /// <summary>
             /// Return <see cref="StateSet"/>s for the given <see cref="Project"/>. 
             /// This will either return already created <see cref="StateSet"/>s for the specific snapshot of <see cref="Project"/> or
@@ -115,7 +106,6 @@ private void RaiseProjectAnalyzerReferenceChanged(ProjectAnalyzerReferenceChange
                 => ProjectAnalyzerReferenceChanged?.Invoke(this, args);
 
             private static ImmutableDictionary<DiagnosticAnalyzer, StateSet> CreateStateSetMap(
-                string language,
                 IEnumerable<ImmutableArray<DiagnosticAnalyzer>> projectAnalyzerCollection,
                 IEnumerable<ImmutableArray<DiagnosticAnalyzer>> hostAnalyzerCollection,
                 bool includeWorkspacePlaceholderAnalyzers)
@@ -124,8 +114,8 @@ private static ImmutableDictionary<DiagnosticAnalyzer, StateSet> CreateStateSetM
 
                 if (includeWorkspacePlaceholderAnalyzers)
                 {
-                    builder.Add(FileContentLoadAnalyzer.Instance, new StateSet(language, FileContentLoadAnalyzer.Instance, isHostAnalyzer: true));
-                    builder.Add(GeneratorDiagnosticsPlaceholderAnalyzer.Instance, new StateSet(language, GeneratorDiagnosticsPlaceholderAnalyzer.Instance, isHostAnalyzer: true));
+                    builder.Add(FileContentLoadAnalyzer.Instance, new StateSet(FileContentLoadAnalyzer.Instance, isHostAnalyzer: true));
+                    builder.Add(GeneratorDiagnosticsPlaceholderAnalyzer.Instance, new StateSet(GeneratorDiagnosticsPlaceholderAnalyzer.Instance, isHostAnalyzer: true));
                 }
 
                 foreach (var analyzers in projectAnalyzerCollection)
@@ -143,7 +133,7 @@ private static ImmutableDictionary<DiagnosticAnalyzer, StateSet> CreateStateSetM
                             continue;
                         }
 
-                        builder.Add(analyzer, new StateSet(language, analyzer, isHostAnalyzer: false));
+                        builder.Add(analyzer, new StateSet(analyzer, isHostAnalyzer: false));
                     }
                 }
 
@@ -162,38 +152,15 @@ private static ImmutableDictionary<DiagnosticAnalyzer, StateSet> CreateStateSetM
                             continue;
                         }
 
-                        builder.Add(analyzer, new StateSet(language, analyzer, isHostAnalyzer: true));
+                        builder.Add(analyzer, new StateSet(analyzer, isHostAnalyzer: true));
                     }
                 }
 
                 return builder.ToImmutable();
             }
 
-            private readonly struct HostAnalyzerStateSetKey : IEquatable<HostAnalyzerStateSetKey>
-            {
-                public HostAnalyzerStateSetKey(string language, bool hasSdkCodeStyleAnalyzers, IReadOnlyList<AnalyzerReference> analyzerReferences)
-                {
-                    Language = language;
-                    HasSdkCodeStyleAnalyzers = hasSdkCodeStyleAnalyzers;
-                    AnalyzerReferences = analyzerReferences;
-                }
-
-                public string Language { get; }
-                public bool HasSdkCodeStyleAnalyzers { get; }
-                public IReadOnlyList<AnalyzerReference> AnalyzerReferences { get; }
-
-                public bool Equals(HostAnalyzerStateSetKey other)
-                    => Language == other.Language &&
-                       HasSdkCodeStyleAnalyzers == other.HasSdkCodeStyleAnalyzers &&
-                       AnalyzerReferences == other.AnalyzerReferences;
-
-                public override bool Equals(object? obj)
-                    => obj is HostAnalyzerStateSetKey key && Equals(key);
-
-                public override int GetHashCode()
-                    => Hash.Combine(Language.GetHashCode(),
-                       Hash.Combine(HasSdkCodeStyleAnalyzers.GetHashCode(), AnalyzerReferences.GetHashCode()));
-            }
+            private readonly record struct HostAnalyzerStateSetKey(
+                string Language, bool HasSdkCodeStyleAnalyzers, IReadOnlyList<AnalyzerReference> AnalyzerReferences);
         }
     }
 }

src/LanguageServer/Protocol/Features/Diagnostics/EngineV2/DiagnosticIncrementalAnalyzer.StateSet.cs

@@ -21,16 +21,14 @@ internal partial class DiagnosticIncrementalAnalyzer
         /// </summary>
         private sealed class StateSet
         {
-            public readonly string Language;
             public readonly DiagnosticAnalyzer Analyzer;
             public readonly bool IsHostAnalyzer;
 
             private readonly ConcurrentSet<DocumentId> _activeDocuments;
             private readonly ConcurrentDictionary<ProjectId, ProjectState> _projectStates;
 
-            public StateSet(string language, DiagnosticAnalyzer analyzer, bool isHostAnalyzer)
+            public StateSet(DiagnosticAnalyzer analyzer, bool isHostAnalyzer)
             {
-                Language = language;
                 Analyzer = analyzer;
                 IsHostAnalyzer = isHostAnalyzer;