Use workspace/didChangeWatchedFiles from BSP to communicate file changes to the build system

Author: ahoppen

Sources/BuildServerProtocol/CMakeLists.txt

@@ -1,5 +1,6 @@
 add_library(BuildServerProtocol STATIC
   BuildTargets.swift
+  DidChangeWatchedFilesNotification.swift
   FileOptions.swift
   InitializeBuild.swift
   Messages.swift

Sources/BuildServerProtocol/DidChangeWatchedFilesNotification.swift

@@ -0,0 +1,16 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2014 - 2024 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
+import LanguageServerProtocol
+
+/// Notification sent from SourceKit-LSP to the build system to indicate that files within the project have been modified.
+public typealias DidChangeWatchedFilesNotification = LanguageServerProtocol.DidChangeWatchedFilesNotification

Sources/BuildSystemIntegration/BuildServerBuildSystem.swift

@@ -332,7 +332,7 @@ extension BuildServerBuildSystem: BuiltInBuildSystem {
     }
   }
 
-  package func filesDidChange(_ events: [FileEvent]) {}
+  package func didChangeWatchedFiles(notification: BuildServerProtocol.DidChangeWatchedFilesNotification) {}
 
   package func fileHandlingCapability(for uri: DocumentURI) -> FileHandlingCapability {
     guard

Sources/BuildSystemIntegration/BuildSystem.swift

@@ -197,7 +197,7 @@ package protocol BuiltInBuildSystem: AnyObject, Sendable {
   func unregisterForChangeNotifications(for: DocumentURI) async
 
   /// Called when files in the project change.
-  func filesDidChange(_ events: [FileEvent]) async
+  func didChangeWatchedFiles(notification: BuildServerProtocol.DidChangeWatchedFilesNotification) async
 
   func fileHandlingCapability(for uri: DocumentURI) async -> FileHandlingCapability
 

Sources/BuildSystemIntegration/BuildSystemManager.swift

@@ -101,7 +101,7 @@ package actor BuildSystemManager: BuiltInBuildSystemAdapterDelegate {
   }
 
   package func filesDidChange(_ events: [FileEvent]) async {
-    await self.buildSystem?.underlyingBuildSystem.filesDidChange(events)
+    await self.buildSystem?.send(BuildServerProtocol.DidChangeWatchedFilesNotification(changes: events))
   }
 
   /// Implementation of `MessageHandler`, handling notifications from the build system.

Sources/BuildSystemIntegration/BuiltInBuildSystemAdapter.swift

@@ -79,6 +79,8 @@ actor BuiltInBuildSystemAdapter: BuiltInBuildSystemMessageHandler {
     // sent. We can only do this once all requests to the build system have been migrated and we can implement proper
     // dependency management between the BSP messages
     switch notification {
+    case let notification as DidChangeWatchedFilesNotification:
+      await self.underlyingBuildSystem.didChangeWatchedFiles(notification: notification)
     default:
       logger.error("Ignoring unknown notification \(type(of: notification).method) from SourceKit-LSP")
     }

Sources/BuildSystemIntegration/CompilationDatabaseBuildSystem.swift

@@ -212,8 +212,8 @@ extension CompilationDatabaseBuildSystem: BuiltInBuildSystem {
     }
   }
 
-  package func filesDidChange(_ events: [FileEvent]) async {
-    if events.contains(where: { self.fileEventShouldTriggerCompilationDatabaseReload(event: $0) }) {
+  package func didChangeWatchedFiles(notification: BuildServerProtocol.DidChangeWatchedFilesNotification) async {
+    if notification.changes.contains(where: { self.fileEventShouldTriggerCompilationDatabaseReload(event: $0) }) {
       await self.reloadCompilationDatabase()
     }
   }

Sources/BuildSystemIntegration/SwiftPMBuildSystem.swift

@@ -745,8 +745,8 @@ extension SwiftPMBuildSystem: BuildSystemIntegration.BuiltInBuildSystem {
     }
   }
 
-  package func filesDidChange(_ events: [FileEvent]) async {
-    if events.contains(where: { self.fileEventShouldTriggerPackageReload(event: $0) }) {
+  package func didChangeWatchedFiles(notification: BuildServerProtocol.DidChangeWatchedFilesNotification) async {
+    if notification.changes.contains(where: { self.fileEventShouldTriggerPackageReload(event: $0) }) {
       logger.log("Reloading package because of file change")
       await orLog("Reloading package") {
         try await self.reloadPackage()
@@ -756,7 +756,7 @@ extension SwiftPMBuildSystem: BuildSystemIntegration.BuiltInBuildSystem {
     var filesWithUpdatedDependencies: Set<DocumentURI> = []
     // If a Swift file within a target is updated, reload all the other files within the target since they might be
     // referring to a function in the updated file.
-    for event in events {
+    for event in notification.changes {
       guard event.uri.fileURL?.pathExtension == "swift", let targets = fileToTargets[event.uri] else {
         continue
       }
@@ -774,7 +774,7 @@ extension SwiftPMBuildSystem: BuildSystemIntegration.BuiltInBuildSystem {
     // directory outside the source tree.
     // If we have background indexing enabled, this is not necessary because we call `fileDependenciesUpdated` when
     // preparation of a target finishes.
-    if !isForIndexBuild, events.contains(where: { $0.uri.fileURL?.pathExtension == "swiftmodule" }) {
+    if !isForIndexBuild, notification.changes.contains(where: { $0.uri.fileURL?.pathExtension == "swiftmodule" }) {
       filesWithUpdatedDependencies.formUnion(self.fileToTargets.keys)
     }
     await self.fileDependenciesUpdatedDebouncer.scheduleCall(filesWithUpdatedDependencies)

Tests/BuildSystemIntegrationTests/BuildSystemManagerTests.swift

@@ -509,7 +509,7 @@ class ManualBuildSystem: BuiltInBuildSystem {
   var indexStorePath: AbsolutePath? { nil }
   var indexDatabasePath: AbsolutePath? { nil }
 
-  func filesDidChange(_ events: [FileEvent]) {}
+  func didChangeWatchedFiles(notification: BuildServerProtocol.DidChangeWatchedFilesNotification) {}
 
   package func fileHandlingCapability(for uri: DocumentURI) -> FileHandlingCapability {
     if map[uri] != nil {

Tests/SourceKitLSPTests/BuildSystemTests.swift

@@ -99,7 +99,7 @@ actor TestBuildSystem: BuiltInBuildSystem {
     watchedFiles.remove(uri)
   }
 
-  func filesDidChange(_ events: [FileEvent]) {}
+  func didChangeWatchedFiles(notification: BuildServerProtocol.DidChangeWatchedFilesNotification) async {}
 
   func fileHandlingCapability(for uri: DocumentURI) -> FileHandlingCapability {
     if buildSettingsByFile[uri] != nil {

Tests/SourceKitLSPTests/CompilationDatabaseTests.swift

@@ -38,7 +38,7 @@ final class CompilationDatabaseTests: XCTestCase {
 
     let (mainUri, positions) = try project.openDocument("main.cpp")
 
-    // Do a sanity check and verify that we get the expected result from a hover response before modifing the compile commands.
+    // Do a sanity check and verify that we get the expected result from a hover response before modifying the compile commands.
 
     let highlightRequest = DocumentHighlightRequest(
       textDocument: TextDocumentIdentifier(mainUri),