Enable ExistentialAny

Author: AnthonyLatsis

Package.swift

@@ -6,10 +6,15 @@ import PackageDescription
 /// Swift settings that should be applied to every Swift target.
 var globalSwiftSettings: [SwiftSetting] {
   var result: [SwiftSetting] = [
+    // Swift 7 mode upcoming features. These must be compatible with swift-tools-version.
     .enableUpcomingFeature("InternalImportsByDefault"),
     .enableUpcomingFeature("MemberImportVisibility"),
     .enableUpcomingFeature("InferIsolatedConformances"),
     .enableUpcomingFeature("NonisolatedNonsendingByDefault"),
+    .enableUpcomingFeature("ExistentialAny"),
+
+    // Warning escalation.
+    .unsafeFlags(["-Werror", "ExistentialAny"]),
   ]
   if noSwiftPMDependency {
     result += [.define("NO_SWIFTPM_DEPENDENCY")]

Sources/BuildServerIntegration/BuildServerManager.swift

@@ -205,7 +205,10 @@ private extension BuildServerSpec {
   private func createBuiltInBuildServerAdapter(
     messagesToSourceKitLSPHandler: any MessageHandler,
     buildServerHooks: BuildServerHooks,
-    _ createBuildServer: @Sendable (_ connectionToSourceKitLSP: any Connection) async throws -> BuiltInBuildServer?
+    _ createBuildServer:
+      @Sendable (
+        _ connectionToSourceKitLSP: any Connection
+      ) async throws -> (any BuiltInBuildServer)?
   ) async -> BuildServerAdapter? {
     let connectionToSourceKitLSP = LocalConnection(
       receiverName: "BuildServerManager for \(projectRoot.lastPathComponent)",
@@ -327,7 +330,7 @@ package actor BuildServerManager: QueueBasedMessageHandler {
   /// get `fileBuildSettingsChanged` and `filesDependenciesUpdated` callbacks.
   private var watchedFiles: [DocumentURI: (mainFile: DocumentURI, language: Language)] = [:]
 
-  private var connectionToClient: BuildServerManagerConnectionToClient
+  private var connectionToClient: any BuildServerManagerConnectionToClient
 
   /// The build serer adapter that is used to answer build server queries.
   private var buildServerAdapter: BuildServerAdapter?
@@ -347,7 +350,7 @@ package actor BuildServerManager: QueueBasedMessageHandler {
   /// Provider of file to main file mappings.
   ///
   /// Force-unwrapped optional because initializing it requires access to `self`.
-  private var mainFilesProvider: Task<MainFilesProvider?, Never>! {
+  private var mainFilesProvider: Task<(any MainFilesProvider)?, Never>! {
     didSet {
       // Must only be set once
       precondition(oldValue == nil)
@@ -367,7 +370,7 @@ package actor BuildServerManager: QueueBasedMessageHandler {
   }
 
   /// Build server delegate that will receive notifications about setting changes, etc.
-  private weak var delegate: BuildServerManagerDelegate?
+  private weak var delegate: (any BuildServerManagerDelegate)?
 
   private let buildSettingsLogger = BuildSettingsLogger()
 
@@ -485,12 +488,12 @@ package actor BuildServerManager: QueueBasedMessageHandler {
     buildServerSpec: BuildServerSpec?,
     toolchainRegistry: ToolchainRegistry,
     options: SourceKitLSPOptions,
-    connectionToClient: BuildServerManagerConnectionToClient,
+    connectionToClient: any BuildServerManagerConnectionToClient,
     buildServerHooks: BuildServerHooks,
     createMainFilesProvider:
       @escaping @Sendable (
         SourceKitInitializeBuildResponseData?, _ mainFilesChangedCallback: @escaping @Sendable () async -> Void
-      ) async -> MainFilesProvider?
+      ) async -> (any MainFilesProvider)?
   ) async {
     self.toolchainRegistry = toolchainRegistry
     self.options = options
@@ -656,7 +659,7 @@ package actor BuildServerManager: QueueBasedMessageHandler {
 
   /// - Note: Needed because `BuildSererManager` is created before `Workspace` is initialized and `Workspace` needs to
   ///   create the `BuildServerManager`, then initialize itself and then set itself as the delegate.
-  package func setDelegate(_ delegate: BuildServerManagerDelegate?) {
+  package func setDelegate(_ delegate: (any BuildServerManagerDelegate)?) {
     self.delegate = delegate
   }
 

Sources/BuildServerIntegration/BuiltInBuildServerAdapter.swift

@@ -59,7 +59,7 @@ actor BuiltInBuildServerAdapter: QueueBasedMessageHandler {
   package let messageHandlingQueue = AsyncQueue<BuildServerMessageDependencyTracker>()
 
   /// The underlying build server
-  private var underlyingBuildServer: BuiltInBuildServer
+  private var underlyingBuildServer: any BuiltInBuildServer
 
   /// The connection with which messages are sent to `BuildServerManager`.
   private let connectionToSourceKitLSP: LocalConnection
@@ -69,7 +69,7 @@ actor BuiltInBuildServerAdapter: QueueBasedMessageHandler {
   /// Create a `BuiltInBuildServerAdapter` form an existing `BuiltInBuildServer` and connection to communicate messages
   /// from the build server to SourceKit-LSP.
   init(
-    underlyingBuildServer: BuiltInBuildServer,
+    underlyingBuildServer: any BuiltInBuildServer,
     connectionToSourceKitLSP: LocalConnection,
     buildServerHooks: BuildServerHooks
   ) {

Sources/BuildServerIntegration/CompilationDatabase.swift

@@ -52,7 +52,7 @@ package struct CompilationDatabaseCompileCommand: Equatable, Codable {
     case output
   }
 
-  package init(from decoder: Decoder) throws {
+  package init(from decoder: any Decoder) throws {
     let container = try decoder.container(keyedBy: CodingKeys.self)
     self.directory = try container.decode(String.self, forKey: .directory)
     self.filename = try container.decode(String.self, forKey: .file)
@@ -70,7 +70,7 @@ package struct CompilationDatabaseCompileCommand: Equatable, Codable {
     }
   }
 
-  package func encode(to encoder: Encoder) throws {
+  package func encode(to encoder: any Encoder) throws {
     var container = encoder.container(keyedBy: CodingKeys.self)
     try container.encode(directory, forKey: .directory)
     try container.encode(filename, forKey: .file)
@@ -140,7 +140,7 @@ package struct JSONCompilationDatabase: Equatable, Codable {
   ///
   /// A `URL` representing the directory that contains the `compile_commands.json` must be passed in the decoder's
   /// `userInfo` via the `compileCommandsDirectoryKey`.
-  package init(from decoder: Decoder) throws {
+  package init(from decoder: any Decoder) throws {
     guard let compileCommandsDirectory = decoder.userInfo[.compileCommandsDirectoryKey] as? URL else {
       struct MissingCompileCommandsDirectoryKeyError: Error {}
       throw MissingCompileCommandsDirectoryKeyError()
@@ -169,7 +169,7 @@ package struct JSONCompilationDatabase: Equatable, Codable {
     self = try decoder.decode(JSONCompilationDatabase.self, from: data)
   }
 
-  package func encode(to encoder: Encoder) throws {
+  package func encode(to encoder: any Encoder) throws {
     var container = encoder.unkeyedContainer()
     for command in commands {
       try container.encode(command)

Sources/BuildServerIntegration/ExternalBuildServerAdapter.swift

@@ -93,7 +93,7 @@ actor ExternalBuildServerAdapter {
   private let configPath: URL
 
   /// The `BuildServerManager` that handles messages from the BSP server to SourceKit-LSP.
-  var messagesToSourceKitLSPHandler: MessageHandler
+  var messagesToSourceKitLSPHandler: any MessageHandler
 
   /// The JSON-RPC connection between SourceKit-LSP and the BSP server.
   private(set) var connectionToBuildServer: JSONRPCConnection?
@@ -124,7 +124,7 @@ actor ExternalBuildServerAdapter {
   init(
     projectRoot: URL,
     configPath: URL,
-    messagesToSourceKitLSPHandler: MessageHandler
+    messagesToSourceKitLSPHandler: any MessageHandler
   ) async throws {
     self.projectRoot = projectRoot
     self.configPath = configPath
@@ -135,7 +135,7 @@ actor ExternalBuildServerAdapter {
   /// Change the handler that handles messages from the build server.
   ///
   /// The intended use of this is to intercept messages from the build server by `LegacyBuildServer`.
-  func changeMessageToSourceKitLSPHandler(to newHandler: MessageHandler) {
+  func changeMessageToSourceKitLSPHandler(to newHandler: any MessageHandler) {
     messagesToSourceKitLSPHandler = newHandler
     connectionToBuildServer?.changeReceiveHandler(messagesToSourceKitLSPHandler)
   }

Sources/BuildServerIntegration/SwiftPMBuildServer.swift

@@ -135,7 +135,7 @@ package actor SwiftPMBuildServer: BuiltInBuildServer {
   private var buildDescription: SourceKitLSPAPI.BuildDescription?
 
   /// Maps target ids to their SwiftPM build target.
-  private var swiftPMTargets: [BuildTargetIdentifier: SwiftBuildTarget] = [:]
+  private var swiftPMTargets: [BuildTargetIdentifier: any SwiftBuildTarget] = [:]
 
   private var targetDependencies: [BuildTargetIdentifier: Set<BuildTargetIdentifier>] = [:]
 

Sources/BuildServerIntegration/SwiftlyResolver.swift

@@ -27,7 +27,7 @@ actor SwiftlyResolver {
     let workingDirectory: URL?
   }
 
-  private var cache: LRUCache<CacheKey, Result<URL?, Error>> = LRUCache(capacity: 100)
+  private var cache: LRUCache<CacheKey, Result<URL?, any Error>> = LRUCache(capacity: 100)
 
   /// Check if `compiler` is a symlink to `swiftly`. If so, find the executable in the toolchain that swiftly resolves
   /// to within the given working directory and return the URL of the corresponding compiler in that toolchain.
@@ -37,7 +37,7 @@ actor SwiftlyResolver {
     if let cached = cache[cacheKey] {
       return try cached.get()
     }
-    let computed: Result<URL?, Error>
+    let computed: Result<URL?, any Error>
     do {
       computed = .success(
         try await resolveSwiftlyTrampolineImpl(compiler: compiler, workingDirectory: workingDirectory)

Sources/ClangLanguageService/ClangLanguageService.swift

@@ -54,7 +54,7 @@ package actor ClangLanguageService: LanguageService, MessageHandler {
   private weak var sourceKitLSPServer: SourceKitLSPServer?
 
   /// The connection to the clangd LSP. `nil` until `startClangdProcesss` has been called.
-  var clangd: Connection!
+  var clangd: (any Connection)!
 
   /// Capabilities of the clangd LSP, if received.
   var capabilities: ServerCapabilities? = nil

Sources/CompletionScoring/Semantics/SemanticClassification.swift

@@ -76,7 +76,7 @@ package struct SemanticClassification: Equatable {
     package let scoreComponent: Double
   }
 
-  private var scoreComponents: [CompletionScoreComponent] {
+  private var scoreComponents: [any CompletionScoreComponent] {
     return [
       availability,
       completionKind,

Sources/Diagnose/CommandLineArgumentsReducer.swift

@@ -18,7 +18,7 @@ import Foundation
 extension RequestInfo {
   @MainActor
   func reduceCommandLineArguments(
-    using executor: SourceKitRequestExecutor,
+    using executor: any SourceKitRequestExecutor,
     progressUpdate: (_ progress: Double, _ message: String) -> Void
   ) async throws -> RequestInfo {
     try await withoutActuallyEscaping(progressUpdate) { progressUpdate in
@@ -34,7 +34,7 @@ extension RequestInfo {
 private class CommandLineArgumentReducer {
   /// The executor that is used to run a sourcekitd request and check whether it
   /// still crashes.
-  private let sourcekitdExecutor: SourceKitRequestExecutor
+  private let sourcekitdExecutor: any SourceKitRequestExecutor
 
   /// A callback to be called when the reducer has made progress reducing the request
   private let progressUpdate: (_ progress: Double, _ message: String) -> Void
@@ -43,7 +43,7 @@ private class CommandLineArgumentReducer {
   private var initialCommandLineCount: Int = 0
 
   init(
-    sourcekitdExecutor: SourceKitRequestExecutor,
+    sourcekitdExecutor: any SourceKitRequestExecutor,
     progressUpdate: @escaping (_ progress: Double, _ message: String) -> Void
   ) {
     self.sourcekitdExecutor = sourcekitdExecutor